diff --git a/marked/G/T-REC-G.1051-202303-I_PDF-E/raw.md b/marked/G/T-REC-G.1051-202303-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..873d4338ef8bc35e62894ca91e97a73e4f4f8fe4
--- /dev/null
+++ b/marked/G/T-REC-G.1051-202303-I_PDF-E/raw.md
@@ -0,0 +1,888 @@
+
+
+# Recommendation **ITU-T G.1051 (03/2023)**
+
+SERIES G: Transmission systems and media, digital systems and networks
+
+Multimedia Quality of Service and performance – Generic and user-related aspects
+
+# --- **Latency measurement and interactivity scoring under real application data traffic patterns**
+
+![ITU logo](0538daaa5583c23e17db3a12f2281a55_img.jpg)
+
+The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue globe with white lines representing latitude and longitude, and the letters 'ITU' in a bold, blue, sans-serif font.
+
+ITU logo
+
+## ITU-T G-SERIES RECOMMENDATIONS **TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS**
+
+|                                                                                                                                              |                      |
+|----------------------------------------------------------------------------------------------------------------------------------------------|----------------------|
+| INTERNATIONAL TELEPHONE CONNECTIONS AND CIRCUITS                                                                                             | G.100–G.199          |
+| GENERAL CHARACTERISTICS COMMON TO ALL ANALOGUE CARRIER-TRANSMISSION SYSTEMS                                                                  | G.200–G.299          |
+| INDIVIDUAL CHARACTERISTICS OF INTERNATIONAL CARRIER TELEPHONE SYSTEMS ON METALLIC LINES                                                      | G.300–G.399          |
+| GENERAL CHARACTERISTICS OF INTERNATIONAL CARRIER TELEPHONE SYSTEMS ON RADIO-RELAY OR SATELLITE LINKS AND INTERCONNECTION WITH METALLIC LINES | G.400–G.449          |
+| COORDINATION OF RADIOTELEPHONY AND LINE TELEPHONY                                                                                            | G.450–G.499          |
+| TRANSMISSION MEDIA AND OPTICAL SYSTEMS CHARACTERISTICS                                                                                       | G.600–G.699          |
+| DIGITAL TERMINAL EQUIPMENTS                                                                                                                  | G.700–G.799          |
+| DIGITAL NETWORKS                                                                                                                             | G.800–G.899          |
+| DIGITAL SECTIONS AND DIGITAL LINE SYSTEM                                                                                                     | G.900–G.999          |
+| <b>MULTIMEDIA QUALITY OF SERVICE AND PERFORMANCE – GENERIC AND USER-RELATED ASPECTS</b>                                                      | <b>G.1000–G.1999</b> |
+| TRANSMISSION MEDIA CHARACTERISTICS                                                                                                           | G.6000–G.6999        |
+| DATA OVER TRANSPORT – GENERIC ASPECTS                                                                                                        | G.7000–G.7999        |
+| PACKET OVER TRANSPORT ASPECTS                                                                                                                | G.8000–G.8999        |
+| ACCESS NETWORKS                                                                                                                              | G.9000–G.9999        |
+
+*For further details, please refer to the list of ITU-T Recommendations.*
+
+# Recommendation ITU-T G.1051
+
+# Latency measurement and interactivity scoring under real application data traffic patterns
+
+## Summary
+
+An important aspect of the data transmission performance of networks are data transfer times and resulting answering delay in real-time, interactive scenarios. Latency and reactivity are becoming even more essential for new interactive and real-time applications as e.g., in augmented reality but also in Industry 4.0 or automotive use.
+
+Latency and resulting reactivity must be measured in a scenario that emulates the application and use case to be evaluated. This requires first a data transfer profile (traffic pattern) that is considered as equivalent to the application so that the relevant latency and reactivity can be measured. Second, the resulting influence of latency to a certain application can be described by an interactivity scoring model. This model is not a general one, rather, it is individually scaled for each of the use cases like e.g., e-Gaming or real-time drone control and is focused on scoring transport with a simplified, parametrizable model approach, it does not target individual application behaviours.
+
+## History
+
+| Edition | Recommendation | Approval   | Study Group | Unique ID*                                                                |
+|---------|----------------|------------|-------------|---------------------------------------------------------------------------|
+| 1.0     | ITU-T G.1051   | 2023-03-01 | 12          | <a href="http://handle.itu.int/11.1002/1000/15468">11.1002/1000/15468</a> |
+
+## Keywords
+
+Data traffic patterns, interactivity, latency, round-trip time.
+
+---
+
+\* To access the Recommendation, type the URL <http://handle.itu.int/> in the address field of your web browser, followed by the Recommendation's unique ID. For example, <http://handle.itu.int/11.1002/1000/11830-en>.
+
+## FOREWORD
+
+The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis.
+
+The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics.
+
+The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1.
+
+In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC.
+
+## NOTE
+
+In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party.
+
+## INTELLECTUAL PROPERTY RIGHTS
+
+ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process.
+
+As of the date of approval of this Recommendation, ITU had received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at <http://www.itu.int/ITU-T/ipr/>.
+
+© ITU 2023
+
+All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU.
+
+## Table of Contents
+
+|      |                                                                                                                                                                                  | Page |
+|------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------|
+| 1    | Scope .....                                                                                                                                                                      | 1    |
+| 2    | References.....                                                                                                                                                                  | 1    |
+| 3    | Definitions .....                                                                                                                                                                | 1    |
+| 4    | Abbreviations and acronyms .....                                                                                                                                                 | 2    |
+| 5    | Conventions .....                                                                                                                                                                | 2    |
+| 6    | Introduction.....                                                                                                                                                                | 2    |
+| 7    | Test method to obtain two-way latency .....                                                                                                                                      | 2    |
+| 7.1  | Approach to obtain two-way latency .....                                                                                                                                         | 2    |
+| 7.2  | Extending the approach to asymmetrical traffic.....                                                                                                                              | 3    |
+| 7.3  | Guidelines to derive traffic patterns from real applications .....                                                                                                               | 4    |
+| 8    | Latency test results and metrics.....                                                                                                                                            | 5    |
+| 8.1  | Per-packet two-way latency.....                                                                                                                                                  | 5    |
+| 8.2  | Packet delay variation .....                                                                                                                                                     | 5    |
+| 8.3  | Inter-packet delay variation .....                                                                                                                                               | 5    |
+| 8.4  | Lost packets .....                                                                                                                                                               | 6    |
+| 9    | Interactivity prediction model and related test case definition.....                                                                                                             | 6    |
+| 9.1  | Principles of the generic interactivity model approach.....                                                                                                                      | 6    |
+| 9.2  | Parametrization of an interactivity model.....                                                                                                                                   | 7    |
+| 9.3  | Guidelines for application grouping.....                                                                                                                                         | 8    |
+| 9.4  | Guidelines for defining test cases.....                                                                                                                                          | 8    |
+|      | Annex A – Computational structure of a generic interactivity model approach.....                                                                                                 | 9    |
+| A.1  | Introduction.....                                                                                                                                                                | 9    |
+| A.2  | Modelling approach for perceived interactivity of interactive applications ...                                                                                                   | 9    |
+| A.3  | Consideration of lost and discarded packets and packet delay variation in<br>the model.....                                                                                      | 10   |
+| A.4  | Conclusion .....                                                                                                                                                                 | 12   |
+|      | Appendix I – Example generic traffic patterns and model parameters according to<br>Annex A .....                                                                                 | 14   |
+| I.1  | Principle of application emulation and model parameters.....                                                                                                                     | 14   |
+| I.2  | Examples for application emulation and interactivity score computation.....                                                                                                      | 14   |
+|      | Appendix II – Parameter implementation according to Annex A based on subjective<br>results for cloud gaming considering a real example application on client and<br>server ..... | 20   |
+| II.1 | Introduction.....                                                                                                                                                                | 20   |
+| II.2 | Traffic patterns.....                                                                                                                                                            | 20   |
+| II.3 | Guidance for adaptation.....                                                                                                                                                     | 21   |
+| II.4 | Parameters for approximation subjective scores for cloud gaming .....                                                                                                            | 22   |
+|      | Bibliography .....                                                                                                                                                               | 25   |
+
+
+
+# Recommendation ITU-T G.1051
+
+# Latency measurement and interactivity scoring under real application data traffic patterns
+
+# 1 Scope
+
+The scope of this Recommendation is to specify a method to measure continuously data two-way latency and loss for a defined observation period. The basis for this method can be IETF's Two-Way Active Measurement Protocol (TWAMP). The typical symmetrical fixed-rate stream method will be modified to reflect situations in today's telecommunication networks including mobile scenarios and typical interactive use cases. The measurement approach is designed to also cover 5G URLLC configurations.
+
+In this approach, a scalable UDP packet stream is sent from and reflected by a far-end server back to the measurement client, e.g., from a smartphone or modem device to a server in the network or a second device.
+
+Based on the results of the latency, latency variation and loss measurements, a generic approach for a model describing interactivity as a single figure of merit is developed. Because the measurement results and the interactivity model depend on the chosen traffic pattern emulating an application, there will be clear rules to derive traffic patterns and corresponding model configurations as well as defined traffic patterns and formulas for popular applications (by applying the defined rules). This allows an immediate application of the measurement approach and enables later extension for new, arising applications.
+
+# 2 References
+
+The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation.
+
+- [ITU-T Y.1540] Recommendation ITU-T Y.1540 (2019), *Internet protocol data communication service – IP packet transfer and availability performance parameters*.
+- [3GPP TS 23.501] 3GPP TS 23.501 (2020), *System architecture for the 5G system (5GS)*.
+- [IETF RFC 5357] IETF RFC 5357 (2008), *A two-way active measurement protocol (TWAMP)*.
+- [IETF RFC 5481] IETF RFC 5481 (2009), *Packet delay variation applicability statement*.
+- [IETF RFC 6038] IETF RFC 6038 (2010), *Two-way active measurement protocol (TWAMP) reflect octets and symmetrical size features*.
+
+## 3 Definitions
+
+None.
+
+## 4 Abbreviations and acronyms
+
+This Recommendation uses the following abbreviations and acronyms:
+
+|       |                                          |
+|-------|------------------------------------------|
+| 5QI   | 5G Quality of Service Identifier         |
+| ACR   | Absolute Category Rating                 |
+| DL    | Downlink direction in mobile connection  |
+| HD    | High Definition (video)                  |
+| IP    | Internet Protocol                        |
+| IPDV  | Inter-Packet Delay Variation             |
+| MOS   | Mean Opinion Score                       |
+| MTU   | Maximum Transmission Unit                |
+| PDV   | Packet Delay Variation                   |
+| QoS   | Quality of Service                       |
+| RTT   | Round-Trip Time                          |
+| TWAMP | Two-Way Active Measurement Protocol      |
+| UDP   | User Datagram Protocol                   |
+| UDPST | User Datagram Protocol Speed Test        |
+| UL    | Uplink direction in mobile connection    |
+| URLLC | Ultra-Reliable Low-Latency Communication |
+
+## 5 Conventions
+
+None.
+
+# 6 Introduction
+
+This Recommendation describes the technical realization of two-way delay measurements, how to apply this approach to emulate real application traffic and how to obtain the metrics and results from this measurement.
+
+The introduced measurement method considers specific characteristics of mobile networks and, in general, dynamically adjusted and load-dependent networks and connections.
+
+This Recommendation also gives advice on how to derive load and traffic patterns from real applications as well as for adjusting the scalable interactivity model to the target use case or application.
+
+One realization of an on-the-top model to predict interactivity of the tested connection is described in Annex A.
+
+# 7 Test method to obtain two-way latency
+
+## 7.1 Approach to obtain two-way latency
+
+A typical approach to obtain two-way latency is sending packets to a reflecting unit in the network and measuring the time between sending and receiving the corresponding packets. Time stamps for each packet from the sending and reflecting unit are required to obtain the key performance indicators (KPIs) defined in this Recommendation.
+
+As an established example, the TWAMP methodology and protocol can be considered, as defined in [IETF RFC 5357]; additional notes can be found in [IETF RFC 6038]. It is based on a UDP packet stream of packets of pre-defined size and frequency. The packets are sent to a reflecting server that sends the packet back to the sending client, where the received reflected packet can be assigned to a sent packet by an ID. The difference of the sending and receiving time stamps are reported as two-way latency. The TWAMP protocol according to IETF is defined and – depending on the vendor – supported by infrastructure components such as routers and IP-gateways.
+
+In addition to two-way packet latency, the TWAMP methodology also supports the calculation of one-way packet-delay variation (PDV), separated into uplink and downlink directions, as well as the detection of lost packets based on packet sequence numbers.
+
+The amount of data to transmit and the resulting data rate can be specified by packet size and sending frequency. This allows an emulation of data stream characteristics as produced by real applications.
+
+Other methods to obtain packet round-trip time (RTT) and one-way delay jitter and packet loss in sufficient temporal resolution can also be used such as that based on the UDPST method as described in [b-IETF] and is available under [b-OB-UDPST].
+
+## 7.2 Extending the approach to asymmetrical traffic
+
+A pure reflection of received packets by a reflecting unit leads to widely identical and symmetrical data streams in direction to and from the reflecting unit. Each sent packet triggers a reflected packet of the same size. Consequently, packet size and frequency and the resulting data rate are the same. This symmetrical traffic is a special case and does not emulate most real applications, where the traffic is asymmetrical, meaning different in each direction.
+
+Additional notes about the method as specified in [IETF RFC 6038] are focused on achieving absolutely symmetrical traffic; the received packets are reflected exactly back to the sender. Consequently, the amount of data requested to transmit is the same in the send and receive directions.
+
+The definition of additional TWAMP features in [IETF RFC 6038] has already foreseen the possibility to define the size of the reflected packets<sup>1</sup>.
+
+A different size of the reflected packet generates asymmetrical traffic; the reflected packet stream can result in a higher or lower bitrate. It must be noted that this way the asymmetrical traffic is only achieved by varying the packet size, not the packet frequency.
+
+There can be implementations realized, where also the packet frequency varies in either direction. A received packet at the reflecting unit can trigger sending multiple packets instead of one. It depends on the implementation and the target traffic pattern to be emulated whether these packets are sent in an equidistant way or as bursts.
+
+Vice versa, there might also be implementations where multiple received packets at the reflecting unit trigger less or just one packet to be sent back to the client side. Also, in this case the targeted traffic pattern defines the parameters of asymmetry.
+
+If the reflected packet must carry a higher number of bytes than the sent one, the packet is extended by random bits. This is the more usual case (uplink rate < downlink rate). If the reflected packet must be smaller, the payload is cut to the target size, where the lower limit is the header information of the packet for its identification.
+
+Alternative methods as UDPST as described in [b.1] also offer techniques to realize different load per direction resulting in a desired asymmetrical traffic pattern.
+
+---
+
+<sup>1</sup> The implementation is not part of [IETF RFC 6038] and is left to the implementor. Preferably, the implementation carries the information of how many octets should be reflected in each packet. Thus, the asymmetry of the traffic can be defined per packet as highest granularity.
+
+## 7.3 Guidelines to derive traffic patterns from real applications
+
+When creating a traffic pattern, the goal is to derive an archetype traffic pattern that is representative for the target application. This should usually cover the main usage scenarios of a group of similar applications such as 'high-interactive e-Gaming' or 'remote drone control'. Alternatively, the traffic pattern could also be targeted to an individual application and use case.
+
+First, the traffic created by several representative real applications should be analysed. The IP trace should be recorded in the different phases of application usage, for example initializing phase, active interaction, passive use and trailing phase. For all applications, use cases and usage phases, the traffic should be analysed regarding uplink and downlink bitrate, packet size and frequency.
+
+#### 7.3.1 Temporal structure of traffic patterns
+
+The next step is the definition of a traffic pattern by segments of different bitrates. The proportion of bitrates and their profile vs time should be driven by the real use but in a shorter overall duration (e.g., 10 s to 15 s, where segment duration can be down to 1 s). The order of the segments should resemble the real-time profile, e.g., start with an initializing phase and not a highly interactive phase. In asymmetrical traffic scenarios, the uplink and downlink bitrates can differ and have a different proportion for each segment.
+
+#### 7.3.2 Controlling data rate by packet size and frequency
+
+The packet stream realized e.g., by TWAMP as in [IETF RFC 5357] and [IETF RFC 6038] is considered an emulation of a traffic pattern of a real application. This load is not only defined by an average or short-term bitrate but rather by the underlying packet sizes and frequency. Packet size and frequency can be different for individual applications even the resulting bitrate is the same. Some applications may send small packets in higher frequency, while others send larger packets but in lower frequency.
+
+Therefore, the target bitrates for the segments have to be broken into the parameters' packet size and packet sending frequency. The packet size is limited to the range between the minimum defined by the header size of all transport protocols including the TWAMP header and the maximum defined e.g., by TWAMP as in [IETF RFC 6038] (~65 000 bytes). Within this range, the packet size and frequency should be set to resemble the real application traffic.
+
+Packet sizes exceeding one maximum transmission unit (MTU) will be split into multiple MTUs transmitted and received sequentially. The receiving side will then assemble the incoming MTUs to one UDP packet. It should be noted that the latency and the corresponding PDVs are calculated based on the reception of the latest MTU forming this individual packet. Furthermore, a packet is counted as lost if a single MTU is lost or erroneous.
+
+This consideration of oversized packets will result in data streams close to a real application. An oversized packet is split into several MTUs but these MTUs are transferred directly one after another as a bulk of MTUs. After transmitting, there can be a pause until the next oversized packet is split and transmitted. The more bursty data traffic on lower layers is closer to resembling the reality for those applications.<sup>2</sup>
+
+One additional restriction applies to the packet frequency if TWAMP as in [IETF RFC 5357] is used: The defined packet frequency applies for uplink and downlink traffic within one segment, because of the round-trip nature of the measurement. Packets are only reflected at the server side, not multiplied nor discarded. Thus, the packet frequency in both directions is identical.
+
+---
+
+<sup>2</sup> A typical example application is UHD video streaming, where single frames are packetized but exceed the MTU size and are split. Nevertheless, the entire packet (video frame) is considered as lost if the transport of a single MTU fails.
+
+# 8 Latency test results and metrics
+
+## 8.1 Per-packet two-way latency
+
+The realization of the described two-way latency measurement method allows the determination of the latency of each individual sent and received UDP packet. As a result of the measurement, the vector  $D(i)$ , where  $D$  is the latency of an individual packet  $i$  for a measurement interval, is available for detailed analysis.
+
+As statistical aggregation metrics of  $D(i)$  quantiles are recommended:
+
+- Delay  $D(i)$  50<sup>th</sup> percentile (median)
+- Delay  $D(i)$  10<sup>th</sup> percentile (approximation for the shortest reachable latencies in practice)
+
+An arithmetic average as statistical mean for characterization of the latency in a measurement interval cannot be recommended, since individual extreme latencies dominate this average. Measured packet latencies follow a so-called heavy-tailed distribution with reduced meaning of arithmetic averages.
+
+## 8.2 Packet delay variation
+
+In line with [ITU-T Y.1540] and [IETF RFC 5481], the packet delay of an individual packet is rated to the minimal packet latency and is defined as:
+
+$$PDV(i) = D(i) - D(\min) \text{ where } PDV(i) \in \mathbb{R}^+$$
+
+where  $D(i)$  is the individual latency of one packet and  $D(\min)$  is the minimum individual latency of all packets in the measurement interval.
+
+PDV values can only be zero or positive, and quantiles of the PDV distribution are direct indications of delay variation.
+
+This vector  $PDV(i)$  is used to calculate the:
+
+- $PDV$  50<sup>th</sup> percentile (median)
+- $PDV$  99.9<sup>th</sup> percentile (approx. maximum)
+
+The PDV is a relative measure with respect to the packet with the shortest latency. This enables the provision of the PDV per direction, as no time synchronization is needed for relative measures. Based on the timestamps of sending at client side and receiving at server side, the uplink one-way PDV can be computed. Likewise, based on the timestamps of sending at server side and receiving at client side the downlink one-way PDV can be derived. Consequently, PDV is available as:
+
+- $PDV_{CS}$  one-way (client to server)
+- $PDV_{SC}$  one-way (server to client)
+
+In principle and if needed, also the resulting two-way PDV (client to server and return) can be obtained from the available timestamps.
+
+## 8.3 Inter-packet delay variation
+
+In line with [IETF RFC 5481], the inter-packet delay variation (IPDV)<sup>3</sup> of an individual packet is rated to the delay of the previous packet and is defined as:
+
+$$IPDV(i) = D(i) - D(i - 1) \text{ where } i \in N$$
+
+where  $D(i)$  is the individual delay of one packet.
+
+IPDV values can be both negative and positive, and percentiles of the IPDV distribution are direct indications of delay variation.
+
+---
+
+<sup>3</sup> Please note that IPDV is also used as an abbreviation for IP-packet delay variation in other contexts.
+
+This vector  $IPDV(i)$  is used to calculate the:
+
+- $IPDV_{>0}$  34.1<sup>th</sup> percentile (standard deviation under assumption of normal distribution)
+- $IPDV_{>0}$  99.9<sup>th</sup> percentile (approx. maximum)
+
+Here  $IPDV_{>0}$  denotes the vector of all positive values of IPDV.
+
+The IPDV is a relative measure with respect to the previous packet. This enables the provision of the IPDV per direction, as no time synchronization is needed for relative measures. Based on the timestamps of sending at client side and receiving at server side, the uplink one-way IPDV can be computed. Likewise, based on the timestamps of sending at server side and receiving at client side the downlink one-way IPDV can be derived. Consequently, IPDV is available as:
+
+- $IPDV_{CS}$  one-way (client to server)
+- $IPDV_{SC}$  one-way (server to client)
+
+In principle and if needed, additionally the resulting two-way IPDV (client to server and return) can be obtained from the available timestamps.
+
+## 8.4 Lost packets
+
+Packets which are not received on the IP-interface of client or server side are counted as lost.
+
+This covers more than lost packets that are actually lost, in particular:
+
+- Not sent packets: Packets that could not leave the client device due to uplink congestion and being discarded by the device kernel after timeout.
+- Lost packets: Packets that were lost during transmission or could not leave the reflecting server due to downlink congestion and being discarded by the server kernel after timeout. Lost packets can be determined at the reflecting server side as well as at the receiving client. Lost packets can be reported for either one-way separately or two-way.
+- Erroneous packets: Packets that were corrupted after arriving back at the client device.<sup>4</sup>
+
+An overall indicator as the ratio of lost packets  $P_L$  can be computed simply by:
+
+$$P_L = \text{number of lost packets} / \text{number of all packets sent by the application}$$
+
+The packet loss  $P_L$  can also be calculated per direction separately if the underlying method allows it.
+
+$$P_{L\_CS} = \text{number of lost packets at server side} / \text{number of all packets sent by the client application}$$
+
+$$P_{L\_SC} = \text{number of lost packets at client receiving side} / \text{number of all packets sent by the server}$$
+
+# 9 Interactivity prediction model and related test case definition
+
+### 9.1 Principles of the generic interactivity model approach
+
+Obtaining latency, PDV, IPDV and packet loss opens the possibility to create a prediction model for perceived interactivity for individual applications or application classes. An application class could be, for example, HD video chat or online gaming, where the effect of delay, jitter and loss on perception is comparable in between the individual realizations of the application.
+
+The basic concept of scoring interactivity is that the latency and number of lost and unusable packets determine the interactivity perceived by a user. Two-way packet latency gives information on how fast a response to an action originated at the client user device is received back at the device side. In
+
+---
+
+<sup>4</sup> Please note that usually the IP kernel of the operating system discards corrupted packets below the IP interface level. When tracing packets at IP level, corrupted packets are seen as lost.
+
+addition, disqualified packets are missing information for the user's application. They can be lost packets as in clause 8.4 or packets considered as discarded by exceeding a delay limit. Those lost and discarded packets are defined as disqualified packets.<sup>5</sup> Whether disqualified packets can be interpolated by the application or only lead to temporary distortions, pausing while using the application or even stopping the application completely depends on the application itself and its implementation.
+
+To receive results for latency and ratio of disqualified packets as close to a real application as possible, the packet stream – especially in data-rate and traffic pattern – should emulate the targeted application in use.
+
+Latency of the received packets and number of disqualified packets determine the perceived interactivity, but the influence on the perceived interactivity of an application or use case depends on the target application and the expectation of the user.
+
+Consequently, there will not be one single prediction model for interactivity, but rather individual ones for different applications. Considering the huge number of potential applications, a generic and scalable approach is developed and described in this Recommendation.
+
+Therefore, the following principles are anticipated:
+
+- Same input parameter types for derived interactivity models
+- Same computational structure of the interactivity model
+- Classification of applications and use cases in application types or groups having same or similar expectations of the user
+- Parametrization of the computational model structure to one specific application type or group
+
+Considering the principles above, a fast realization of prediction models is achievable and because of clear application grouping and a transparent approach, the results stay comparable within and across application groups. One example of a model for the computation of an interactivity score based on the principles described above is given in Annex A.
+
+## **9.2 Parametrization of an interactivity model**
+
+#### **9.2.1 Subjective testing**
+
+The most obvious approach to parametrization is the use of data obtained by subjective testing of the application that should be predicted by the interactivity model. Human subjects have to use the application in its interactive stage under different defined channel conditions regarding latency, jitter and loss and to score the perceived interactivity. Based on the results, the best fitting parameters for the above-described model can be derived.
+
+The advantage of this approach is the direct link to human scores of a real application and thus the ability to correctly reflect the priority/weight of different network degradations. Disadvantages are that the application has to exist and that the outcome of the test refers to this dedicated application and it is hardly possible to generalize unless also evaluating how other competing applications behave, which does not have to be done with fully subjective tests. Furthermore, the ambition of a test user in an experimental set-up may not be fully comparable with a real use of the application, where the interests of the user are different.
+
+---
+
+<sup>5</sup> Considering packets exceeding the delay budget as unusable and discarded reflects real-time applications, where delayed packets cannot be considered for e.g., rendering a media stream.
+
+#### 9.2.2 Best practice parametrization
+
+Best practice parametrization models perceive interactivity based on anticipated thresholds for a given application or use case. These anticipated thresholds are derived from expected performance in certain environments while using the application. Basic considerations can be at which latency a perceived degradation of latency starts (e.g., an interactivity score of 90 of 100) and at which latency the perceived interactivity drops significantly (e.g., an interactivity score of 60 of 100, would relate to MOS  $\sim$  3 in a five-point absolute category rating (ACR) test) and/or where the application becomes unusable in practice. In addition, the influence of packet loss and serious packet delay variation should be estimated. This estimation considers known or assumed packet loss and buffering strategies. Examples for best practice parametrization are shown in Appendices I and II..
+
+### 9.3 Guidelines for application grouping
+
+In principle, an individual traffic pattern and interactivity model can be defined for each application or use case. However, there are applications and use cases resulting in very similar patterns and model parameters. For comparability and practical use, it is helpful to test applications and use cases under the same conditions if the traffic shape and/or model parameters are similar.
+
+Traffic pattern similarity should be given in
+
+- Temporal structure of traffic pattern;
+- Applied bit rates.
+
+Model parameter similarity should be given in
+
+- Delay budget for the application;
+- Perceptual influence of packet latency;
+- Degradation by packet latency variations and especially disqualified packets.
+
+The use of the same defined traffic pattern and set of model parameters for different applications is not limited to similar appearance or use; applications can be treated the same although they have a different use, as long as they share the similarities above.
+
+## 9.4 Guidelines for defining test cases
+
+The results obtained by the test method, such as two-way latency, PDV, IPDV and packet loss, depend on the traffic emulated, for example, on bitrate and packet size. Therefore, the measurement of latency must take place under equivalent traffic conditions as in the target application for which latency scores should be obtained.
+
+If the measurement results will be used to estimate the interactivity of an application type, the parametrization of this model must also consider the characteristics of the targeted application such as sensitivity to packet loss, defined delay budget and dependency on latency.
+
+Considering this, a test case for deriving a prediction of interactivity is mainly defined by the used traffic or bitrate profile including packet size and frequency, and – if applied – the model parameters to estimate perceived interactivity. A packet with a two-way latency exceeding the defined delay budget is considered as disqualified, meaning discarded due to late arrival by the emulated application.
+
+Limits for latency of different application classes, grouped by the standardized 5QI value, are given by [3GPP TS 23.501]. These limits apply to network delays. They are preferable to use if the emulated application matches, otherwise best practice assumptions or actual discarding limits of the applications are practicable.
+
+Examples of traffic patterns and corresponding model parameters for a model as described in Annex A are presented in Appendix I.
+
+## Annex A
+
+## Computational structure of a generic interactivity model approach
+
+(This annex forms an integral part of this Recommendation.)
+
+### A.1 Introduction
+
+This annex describes a model for estimation of perceived interactivity. As perceived interactivity strongly depends on the application class, the computational model must be parametrized for dedicated application classes and their demands.
+
+The model is based on the obtained two-way latency per packet from simulated data traffic in a network or transport centric approach.
+
+The basic idea of this model realization is a simple consideration of the application's client and server and its scalable construction across many different application cases. Even though this will not perfectly match each individual application, its main advantage is the comparability between individual settings and modelled test cases due to the same modelling approach being taken.
+
+### A.2 Modelling approach for perceived interactivity of interactive applications
+
+The basic assumption of modelling perceived interactivity is its monotonous dependency on data latency. The shorter the data transport time is, the shorter the response time in an interactive application is and the more interactive the use of the application is perceived to be.
+
+However, this dependency is not a simple linear function; rather there are saturation areas at both tails of the function, where no further change in perception happens even if the latency changes.
+
+A valid approximation of this non-linear dependency is a logistic (sigmoid) function.
+
+$$f(t) = 1 - \frac{1}{1 + e^{-\frac{1}{b}(t-a)}}$$
+
+where  $a$  defines the horizontal shift on the  $t$ -axis and  $b$  the gradient.
+
+For a parametrization that matches the value range of positive latencies and a scaling by  $f_0$  to a maximum score value of  $f_p(0) = f_{max}$ , the following formula is applied:
+
+$$f_p(t, i) = \frac{f_{max}}{f_0} \left( 1 - \frac{1}{1 + e^{-\frac{1}{b}(t_i-a)}} \right) \text{ for } t > 0 \text{ with } f_0 = 1 - \frac{1}{1 + e^{\frac{a}{b}}}$$
+
+where  $t$  is the packet latency in milliseconds,  $i$  is the indicator of the packet,  $a$  defines the shift of  $f_p(t, i)$  directly on the  $t$ -axis in milliseconds and  $b$  defines the gradient of  $f_p(t, i)$ , where larger values of  $b$  make  $f_p(t, i)$  less steep.
+
+The scaling factor  $f_0$  guarantees the maximum score value at  $t = 0$ . In case, the upper saturation area of the  $f_p(t, i)$  starts in the range of  $t > 0$ , the  $f_0$  will be close to 1.0. If  $f_0 \rightarrow 1$ , the parameter  $a$  defines the latency value where the perceived interactivity has fallen to almost 50% of  $f_{max}$ .
+
+In cases where per-packet two-way latency can be obtained, the logistic function can be applied to each individual packet latency. Here, the value  $f_p(t, i)$  is computed for each individual packet  $i$  and its latency  $t$ . The aggregated interactivity based on latencies  $I_L$  for an observation period is the average of all  $f_p(t, i)$ :
+
+$$I_L = \frac{1}{N} \sum_{i=1}^N \frac{f_{max}}{f_0} \left( 1 - \frac{1}{1 + e^{-\frac{1}{b}(t_i-a)}} \right)$$
+
+In cases where the per-packet two-way latency cannot be obtained in the test set-up or higher order statistics appear more applicable, the principle of the logistic weighting can be applied to the median of the two-way latencies as a single value input into the function.
+
+$$I_{L-CG} = \frac{f_{max}}{f_0} \left( 1 - \frac{1}{1 + e^{-\frac{1}{b}(RTT_{MEDIAN} - a)}} \right)$$
+
+with  $RTT_{MEDIAN}$  = Median delay of all packets sent by the application
+
+If using the alternative method, the parameters  $a$  and  $b$  may differ from the per-packet application of the sigmoid function.
+
+![Figure A.1: A graph titled 'Logistic weighting of two-way latency (Example)'. The y-axis is labeled f(t) and ranges from 0 to 100. The x-axis is labeled 'Two-way latency/ms' and ranges from 0 to 160. A solid black curve starts at f(t) = 100 at x = 0 and decreases towards 0 as x increases. The curve passes through (60, 50). A legend in the top right corner specifies a = 60, b = 15, and f_max = 100. The text 'G.1051(23)' is in the bottom right corner.](cbc4516eb885829fe8c9dabc0946dcbe_img.jpg)
+
+Figure A.1: A graph titled 'Logistic weighting of two-way latency (Example)'. The y-axis is labeled f(t) and ranges from 0 to 100. The x-axis is labeled 'Two-way latency/ms' and ranges from 0 to 160. A solid black curve starts at f(t) = 100 at x = 0 and decreases towards 0 as x increases. The curve passes through (60, 50). A legend in the top right corner specifies a = 60, b = 15, and f\_max = 100. The text 'G.1051(23)' is in the bottom right corner.
+
+Figure A.1 – Example of a logistic weighting function for two-way latency
+
+If seen from an quality of experience (QoE) perspective, first, parameter  $a$  shifts the latency value, where the decrease of perceived interactivity depending on latency starts along the  $t$ -axis. In case  $f_0$  is close to 1.0, parameter  $a$  directly defines the latency where the predicted interactivity is decreased to 50% of the maximum reachable score. Second,  $b$  determines the sensitivity of the user, means the range of latency, where the perceived interactivity is decreasing from almost maximum to close to zero. Both parameters are depending on the expectation of the user to the application used.
+
+![Figure A.2: Two side-by-side graphs titled 'Logistic weighting of two-way latency (Example)'. The left graph shows three curves for different values of parameter 'a' (60, 90, 120) with b = 15 and f_max = 100. The right graph shows three curves for different values of parameter 'b' (7, 15, 25) with a = 60 and f_max = 100. Both graphs have f(t) on the y-axis (0-100) and 'Two-way latency/ms' on the x-axis (0-160). The text 'G.1051(23)' is in the bottom right corner of the right graph.](011fecb4a85637472f0c697a6cbdb15d_img.jpg)
+
+Figure A.2: Two side-by-side graphs titled 'Logistic weighting of two-way latency (Example)'. The left graph shows three curves for different values of parameter 'a' (60, 90, 120) with b = 15 and f\_max = 100. The right graph shows three curves for different values of parameter 'b' (7, 15, 25) with a = 60 and f\_max = 100. Both graphs have f(t) on the y-axis (0-100) and 'Two-way latency/ms' on the x-axis (0-160). The text 'G.1051(23)' is in the bottom right corner of the right graph.
+
+Figure A.2 – Parametrization of the logistic weighting function for two-way latency
+
+### A.3 Consideration of lost and discarded packets and packet delay variation in the model
+
+#### A.3.1 Disqualified packets
+
+The defined packet loss  $P_L$  reports packets which are not received and cannot be used by the application. In addition to that, a real application will also discard packets which are heavily delayed
+
+and are not received in time. This maximum accepted delay for packets depends on the application and e.g., internal queuing and buffering mechanisms. In general, the more real-time capability an application has to provide, the shorter the acceptable delay. Packets received later than the maximum delay are discarded by the application and would not be usable for a real and running application, for example, for media rendering.
+
+For predicting a perceived interactivity, discarded packets count as lost packets ( $P_L$ ) and are counted cumulatively as disqualified packets. This covers in particular:
+
+- Not sent packets: Packets that could not leave the client device due to uplink congestion and being discarded by the device kernel after timeout.
+- Lost packets: Packets that were lost during transmission or could not leave the reflecting server due to downlink congestion and being discarded by the server kernel after timeout. Lost packets can be determined at the reflecting server side as well as at the receiving client. Lost packets can be reported for either one-way separately as well as for two-way.
+- Erroneous packets: Packets that were corrupted after arriving back at the client device.
+
+as considered in clause 8.4 as lost packets, and additionally
+
+- Discarded packets: Packets that were received back after a pre-defined timeout at the client device. This timeout, also called delay budget, emulates discarding by a real application because of too long a delay. The timeout is specified and defined according to the maximum acceptable latency for the target application and forms one parameter of emulation of the application.
+
+From an application's point of view, no differentiation is needed between the individual causes of not considering a packet as received. An overall indicator such as the ratio of disqualified packets  $P_{DQ}$  is seen as sufficient at application level.
+
+$$P_{DQ} = \text{number of disqualified packets} / \text{number of all packets sent by the application}$$
+
+As a consequence, all packets considered as usable by the application are defined as qualified packets.
+
+#### A.3.2 PDV considering delay budget
+
+In clause 8.2, the packet delay variation (PDV) is defined. The PDV is derived from the received packet stream without considering discarding due to the applied delay budget. As for prediction of the perceived interactivity a delay budget is applied, the PDV of the incoming packet stream does not reflect anymore the packet delay variation to be considered by the emulated application.
+
+To reflect the packet delay variation within the applied delay budget, the formula of PDV is applied to packet delays considering only the qualified packets according to clause A.3.2.1 and defined as  $PDV_Q$ . In the further modelling, the standard deviation across all  $PDV_Q$  values is defined as  $PDV_{sQ}$ .
+
+The  $PDV_{sQ}$  describing delay variation from client to server and return can be calculated based on two-way latencies, where the time difference between sending a packet and receiving back its reflection is measured.
+
+If the two-way PDV cannot be obtained, alternatively the standard deviation of PDV or IPDV can be computed individually per link direction.<sup>6</sup> Here, IPDV and resulting  $IPDV_{sQ}$  are measured for either direction separately and the average of the standard deviations of IPDV in the uplink and downlink direction is considered as substitute of two-way  $PDV_{sQ}$ . If using the per-link computation, the parameter  $u$  may differ from that defined for two-way  $PDV_{sQ}$ .
+
+---
+
+<sup>6</sup> This separation into IPDV per link is also required in case of asymmetrical traffic patterns using different packet frequencies in each direction. There is no one-to-one relation between sent and received packets which is the pre-condition for a two-way PDV or two-way IPDV.
+
+#### A.3.3 Consideration of disqualified packets and two-way PDV in the interactivity model
+
+In addition to latency, it is anticipated that delay variation and number of disqualified packets also contribute to perceived interactivity. To simplify, both indicators are considered as degrading factors  $D_{PDV}$  and  $D_{DQ}$  by multiplication:
+
+$$IntAct = I_L \times D_{PDV} \times D_{DQ}, \text{ with } D_{PDV} = 1 - PDV_{SQ} / u, \text{ and } D_{DQ} = 1 - v P_{DQ}$$
+
+In the expression above,  $PDV_{SQ}$  is the standard deviation across all  $PDV_Q$  values,  $P_{DQ}$  is the ratio of disqualified packets, and  $u$  and  $v$  are parameters that determine the impact of the degradations on interactivity. Alternatively,  $PDV_{SQ}$  can also be used as descriptor for the standard deviation of  $IPDV_Q$ .
+
+The multiplication with the contributors  $0 < D_{PDV} < 1$  and/or  $0 < D_{DQ} < 1$  will also decrease the maximum value  $IntAct_{max} < I_{Lmax}$ . It means even if latency is very short, if packets are disqualified the maximum score for perceived interactivity can no longer be reached.
+
+For example, a median  $PDV_{SQ}$  of 20 ms will lead to a degrading factor  $D_{PDV} \sim 0.85$  if  $u = 130$ , and a ratio of disqualified packets of 5% ( $P_{DQ} = 0.05$ ) to a degrading factor  $D_{DQ} = 0.65$  if  $v = 7$ .
+
+The influence of  $PDV_{SQ}$  and  $P_{DQ}$  to the weighting function is illustrated in Figure A.3.
+
+![Figure A.3: Logistic weighting of two-way latency (Example). The graph shows three curves representing the weighting function f(t) against two-way latency in ms. The solid line represents the baseline function. The dashed line shows the effect of PDV_SQ = 20 ms and u = 130. The dotted line shows the effect of P_DQ = 5% and v = 7. The parameters used are a = 60, b = 15, and f_max = 100.](dc0cec98faa3ead994c1b171cb56265d_img.jpg)
+
+The figure is a line graph titled "Logistic weighting of two-way latency (Example)". The y-axis is labeled  $f(t)$  and ranges from 0 to 100. The x-axis is labeled "Two-way latency/ms" and ranges from 0 to 160. There are three curves: a solid line, a dashed line, and a dotted line. The solid line starts at 100 at 0 ms and decreases towards 0 as latency increases. The dashed line starts at approximately 85 at 0 ms and follows a similar downward path, crossing the solid line. The dotted line starts at approximately 65 at 0 ms and also decreases, crossing both the solid and dashed lines. Arrows point from labels to the curves: "PDV<sub>SQ</sub> = 20 ms, u = 130" points to the dashed line, and "P<sub>DQ</sub> = 5 %, v = 7" points to the dotted line. A legend in the top right corner specifies parameters:  $a = 60$ ,  $b = 15$ , and  $f_{max} = 100$ . A small code "G.1051(23)" is in the bottom right corner.
+
+Figure A.3: Logistic weighting of two-way latency (Example). The graph shows three curves representing the weighting function f(t) against two-way latency in ms. The solid line represents the baseline function. The dashed line shows the effect of PDV\_SQ = 20 ms and u = 130. The dotted line shows the effect of P\_DQ = 5% and v = 7. The parameters used are a = 60, b = 15, and f\_max = 100.
+
+Figure A.3 – Example of influence of  $PDV_{SQ}$  and  $P_{DQ}$  to the logistic weighting function
+
+Generally, the above-mentioned formula is applied to the entire observation period (e.g., 10 s). To result in a higher temporal granularity, the formula can also be applied to shorter sub-intervals of 1 s, for example.
+
+### A.4 Conclusion
+
+The described computational formula is a simplified, generic approach to retrieve perceived interactivity from latency measurements with the advantage of transparent scalability. The logistic weighting function to estimate a perceived interactivity value from two-way latency measurements ensures a monotonous behaviour and can model perceptual saturation areas at both boundaries of the scale similar to typical perceptual weightings. Degrading effects of delay jitter (derived from  $PDV_{SQ}$ ) and disqualified packet loss ( $P_{DQ}$ ) are considered by simple multiplicative scaling factors. Multiplicative scaling retains the monotonous behaviour and does not change the saturation areas and their cut-off positions.
+
+There may be more accurate formulas for perceived interactivity and individual model structures for dedicated applications, but those definitions require more investigations and are for further study.
+
+## Appendix I
+
+## Example generic traffic patterns and model parameters according to Annex A
+
+(This appendix does not form an integral part of this Recommendation.)
+
+### I.1 Principle of application emulation and model parameters
+
+There are many individual traffic patterns when using an application. They depend on the application itself, the phase in the application (e.g., the gaming scene) and the interaction by the user.
+
+Instead of exactly simulating an individual pattern, a more generalized approach is chosen. At first, applications are classified under consideration of similar use and resulting load, e.g., video chat applications or gaming. For those classes of applications, an analysis of real traffic when using the most common applications of each class was made. The derived patterns do not just represent an average bitrate, rather they emulate some statistical characteristics of the real patterns such as the relative occurrence of data rates (e.g., 50% ~100 kbit/s, 30% ~500 kbit/s and 20% ~2 Mbit/s) as well as typical temporal behaviour in a simple way by e.g., incorporating peaks or longer steady transport.
+
+This principle will load the network statistically in a similar way to a real application of this class and leads to latencies as they can be expected when running this type of application.
+
+These example traffic patterns and the resulting two-way latency values, the measured PDV and packet loss can also be used to estimate a perceived interactivity for this application class by applying a computational interactivity model as described in Annex A.
+
+The model as in Annex A is based on measurements on the transport layer; the measurements do not consider the application itself with respect to specific treatments of transport problems such as packet loss concealment or predictive media rendering, for example, as in video or gaming. The examples given in this appendix are parametrized by applying limits and thresholds defined by 3GPP for individual use cases and might be more challenging than subjective experience including real applications with error treatment.
+
+### I.2 Examples for application emulation and interactivity score computation
+
+#### I.2.1 Example high-interactive 'e-Gaming real-time'
+
+The example traffic pattern for emulating high-interactive e-gaming is derived from heavy multiplayer games. It covers an initializing phase (low-bit-rate) without interaction, a sustainable phase with motion and interaction, the loading of a new game instance as a bit rate peak, a longer sustainable phase of high interaction with up to several hundreds of players and a (low-bit-rate) trailing phase with fewer players and medium interaction. The set bit rates for the phases were taken from real, demanding multiplayer games and represent also in its relative duration and sequence a real gaming session but compressed into a duration of 10 s.
+
+The chosen packet size is 100 bytes sent in a frequency of 125 to 1250 packets per second and the pattern is the same in uplink and downlink, meaning each packet is reflected in the same size. In [3GPP TS 23.501] a maximal one-way latency for online real-time gaming of 50 ms is defined (5QI class 3), the two-way latency therefore should not exceed 100 ms and forms the delay budget for this test case.
+
+![Figure I.1: Example of traffic pattern 'e-Gaming real-time'. The graph shows Data rate/kbit/s on the y-axis (0 to 2000) versus Time/s on the x-axis (0 to 10). The traffic pattern is a step function: 0-1s at 100 kbit/s, 1-2s at 300 kbit/s, 2-3s at 1000 kbit/s, 3-7s at 300 kbit/s, and 7-10s at 100 kbit/s. A label 'up-and downlink' is placed above the 300 kbit/s segment. The code 'G.1051(23)' is in the bottom right corner.](5ed9189841659dfb01f809b8e3b21f74_img.jpg)
+
+Figure I.1: Example of traffic pattern 'e-Gaming real-time'. The graph shows Data rate/kbit/s on the y-axis (0 to 2000) versus Time/s on the x-axis (0 to 10). The traffic pattern is a step function: 0-1s at 100 kbit/s, 1-2s at 300 kbit/s, 2-3s at 1000 kbit/s, 3-7s at 300 kbit/s, and 7-10s at 100 kbit/s. A label 'up-and downlink' is placed above the 300 kbit/s segment. The code 'G.1051(23)' is in the bottom right corner.
+
+**Figure I.1 – Example of traffic pattern 'e-Gaming real-time'**
+
+For parametrization of the interactivity model as described in clause 9.2.2, the following principles are used: A fluent video stream produces 60 frames per second (fps), a movie 24. It is assumed that degradation starts if the channel adds a two-way delay of ~30 ms (two frames delay for 60 fps). Furthermore, a degradation to 60 of 100 for the interactivity score is assumed in case of a two-way delay added by the channel of ~60 ms (four frames for 60 fps). These thresholds can be seen as challenging but refer to highly interactive gaming applications in high speed networks as in 5G URLLC.
+
+In addition, it is anticipated that a  $PDV_{SQ}$  of 30 ms reduces the interactivity as defined by latency by another 10% ( $D_{PDV} = 0.9$ ) and a ratio of disqualified packets of 5% reduces the perceived interactivity by 20% ( $D_{DQ} = 0.8$ ).
+
+The parametrization of the model:
+
+$$IntAct = I_L \times D_{PDV} \times D_{DQ}$$
+
+with  $D_{PDV} = 1 - PDV_{SQ} / u$ ,  $D_{DQ} = 1 - v P_{DQ}$  and  $I_L = \frac{1}{N} \sum_{i=1}^N \frac{f_{max}}{f_0} \left( 1 - \frac{1}{1 + e^{-\frac{1}{b}(t_i - a)}} \right)$
+
+is resulting in:
+
+| Parameter | $f_{max}$ | $a$ | $b$ | $u$ | $v$ |
+|-----------|-----------|-----|-----|-----|-----|
+| Value     | 100       | 61  | 14  | 120 | 4   |
+
+![Figure I.2: Interactivity score 'eGaming' graph. The y-axis is 'Interactivity score' from 0 to 100. The x-axis is 'RTT/ms' from 0 to 400. Two curves are shown: a solid line for PDV_SQ = 40 ms and a dashed line for P_DQ = 2%. Both curves start at 100 and drop to 0 by RTT 150 ms.](60e9207be66a64332619bb4b667fe67b_img.jpg)
+
+Figure I.2 is a line graph titled "Interactivity score 'eGaming'". The y-axis is labeled "Interactivity score" and ranges from 0 to 100 in increments of 10. The x-axis is labeled "RTT/ms" and ranges from 0 to 400 in increments of 50. Two curves are plotted: a solid line representing  $PDV_{SQ} = 40 \text{ ms}$  and a dashed line representing  $P_{DQ} = 2 \%$ . Both curves start at an interactivity score of 100 at 0 ms RTT and decrease sharply, reaching a score of 0 at approximately 150 ms RTT. The dashed line ( $P_{DQ} = 2 \%$ ) shows a slightly higher interactivity score than the solid line ( $PDV_{SQ} = 40 \text{ ms}$ ) for RTT values between 25 ms and 100 ms.
+
+Figure I.2: Interactivity score 'eGaming' graph. The y-axis is 'Interactivity score' from 0 to 100. The x-axis is 'RTT/ms' from 0 to 400. Two curves are shown: a solid line for PDV\_SQ = 40 ms and a dashed line for P\_DQ = 2%. Both curves start at 100 and drop to 0 by RTT 150 ms.
+
+G.1051(23)
+
+**Figure I.2 – Example parametrization for real-time gaming according to Annex A**
+
+#### I.2.2 Example 'Remote drone control'
+
+An example traffic pattern for emulating remote drone control through video illustrates steady but highly asymmetrical traffic, where a low-bit-rate stream of control commands is transferred in uplink to the drone, while the controlling device receives a continuous high bitrate video stream. There are no individual phases with different bit rates; the profile is seen as constant over the observation period. For simplification, the frequency of small uplink control packets and received images is set to the same value. This enables the use of the packet reflection approach as described in [IETF RFC 6038].
+
+The bit rate profile for real-time drone control consists of a 10 s constant 300 kbit/s in uplink and 25 Mbit/s in downlink as defined in use-case scenario 4 ('Remote unmanned aerial vehicle controller through 4k HD video') in [b-3GPP TS 22.125].
+
+Although for the example 'Drone control' the downlink video resolution is chosen to be 4K HD, lower video rates are possible. The example emphasizes the large difference in scale that is possible between uplink and downlink data rate, e.g., 20 times more traffic.
+
+![Figure I.3: Traffic pattern 'Drone control' graph. The y-axis is 'Data rate/kbit/s' from 0 to 30. The x-axis is 'Time/s' from 0 to 10. A solid line at 25 Mbit/s represents the downlink, and a dashed line at 300 kbit/s represents the uplink.](5adf12d50dfea82178ca002a2c48641b_img.jpg)
+
+Figure I.3 is a line graph titled "Traffic pattern 'Drone control'". The y-axis is labeled "Data rate/kbit/s" and ranges from 0 to 30 in increments of 5. The x-axis is labeled "Time/s" and ranges from 0 to 10 in increments of 1. Two lines are plotted: a solid line representing the downlink at 25 Mbit/s and a dashed line representing the uplink at 300 kbit/s. The downlink line is constant at 25 Mbit/s across the entire 10-second duration. The uplink line is constant at 300 kbit/s across the entire 10-second duration. The downlink data rate is significantly higher than the uplink data rate.
+
+Figure I.3: Traffic pattern 'Drone control' graph. The y-axis is 'Data rate/kbit/s' from 0 to 30. The x-axis is 'Time/s' from 0 to 10. A solid line at 25 Mbit/s represents the downlink, and a dashed line at 300 kbit/s represents the uplink.
+
+G.1051(23)
+
+**Figure I.3 – Example of traffic pattern 'drone control'**
+
+The chosen packet size in uplink is 300 bytes sent in a frequency of 125 packets per second and the corresponding packet size in downlink is 25 000 bytes, meaning each packet is reflected in a much larger size. In [b-3GPP TS 22.125] a maximal one-way latency for remote control of 20 ms unmanned aerial vehicle to a terminating unmanned aerial vehicle is defined. The two-way latency therefore should not exceed 40 ms and this value forms the delay budget for this test case.
+
+For parametrization of the interactivity model as described in clause 9.2.2, the following principles are used: A commercial consumer drone reaches 60 km/h average maximum velocity. This results in a flying distance of ~1.6 cm/ms. A beginning degradation (90 of 100 for the interactivity score) can be anticipated at a delay of visual feedback of 10 ms (flying distance ~16 cm), a severe degradation (60 of 100 for the interactivity score) can be assumed for 20 ms and the begin of an unusable two-way delay at > 30 ms (flying distance > 50 cm).
+
+The additional influence of  $PDV_{SQ}$  and disqualified packets is also more severe than for e-gaming. It is anticipated that a  $PDV_{SQ}$  of 5 ms reduces the interactivity as defined by latency by another 10% ( $D_{PDV} = 0.9$ ) and a ratio of disqualified packets of 1% reduces the perceived interactivity already by 20% ( $D_{DQ} = 0.8$ ).
+
+The parametrization of the model is resulting in:
+
+| Parameter | $f_{max}$ | $a$ | $B$ | $u$ | $v$ |
+|-----------|-----------|-----|-----|-----|-----|
+| Value     | 100       | 22  | 6   | 40  | 20  |
+
+![Figure I.4: A line graph titled 'Interactivity score 'Drone control''. The y-axis is 'Interactivity score' from 0 to 100. The x-axis is 'RTT/ms' from 0 to 400. A solid blue curve starts at (0, 100) and drops sharply to 0 at approximately 50 ms RTT. Two points on the curve are highlighted with arrows: 'PDV_SQ = 5 ms' points to a score of approximately 90 at 10 ms RTT, and 'P_DQ = 1%' points to a score of approximately 75 at 20 ms RTT. The graph includes a grid. A small label 'G.1051(23)' is in the bottom right corner.](65f66758012e229247953202e8adf35d_img.jpg)
+
+Figure I.4: A line graph titled 'Interactivity score 'Drone control''. The y-axis is 'Interactivity score' from 0 to 100. The x-axis is 'RTT/ms' from 0 to 400. A solid blue curve starts at (0, 100) and drops sharply to 0 at approximately 50 ms RTT. Two points on the curve are highlighted with arrows: 'PDV\_SQ = 5 ms' points to a score of approximately 90 at 10 ms RTT, and 'P\_DQ = 1%' points to a score of approximately 75 at 20 ms RTT. The graph includes a grid. A small label 'G.1051(23)' is in the bottom right corner.
+
+Figure I.4 – Example parametrization for drone control according to Annex A
+
+#### I.2.3 Examples 'Interactive remote meeting' and 'Video chat HD'
+
+An example traffic pattern for emulating interactive remote meetings with sharing visual information such as live camera streams, desktop sharing and presentations (with change of content) is emulated by steady, sustainable phases of 500 kbit/s symmetrical traffic and two short intervals of 2000 m peaks, where content change (e.g., new slide) happens. This can be seen as a simplified traffic shape typical for several popular remote meeting tools. This example applies asymmetrical traffic, where one peak is applied in uplink, the other one in downlink. It emulates short peaks in either direction.
+
+![Figure I.5: Traffic pattern 'Interactive remote meeting'. A line graph showing data rate in kbit/s over time in seconds. The y-axis ranges from 0 to 2000 kbit/s in increments of 200. The x-axis ranges from 0 to 10 seconds in increments of 1. The graph shows two data series: 'uplink' (dashed line) and 'downlink' (solid line). The uplink starts at 500 kbit/s at 0s, jumps to 2000 kbit/s at 2s, and returns to 500 kbit/s at 3s. The downlink starts at 500 kbit/s at 0s, jumps to 2000 kbit/s at 7s, and returns to 500 kbit/s at 8s. Both series remain at 500 kbit/s until 10s. A label 'G.1051(23)' is in the bottom right corner.](9ce50bc10864dc86e1cdee4be08f1897_img.jpg)
+
+Figure I.5: Traffic pattern 'Interactive remote meeting'. A line graph showing data rate in kbit/s over time in seconds. The y-axis ranges from 0 to 2000 kbit/s in increments of 200. The x-axis ranges from 0 to 10 seconds in increments of 1. The graph shows two data series: 'uplink' (dashed line) and 'downlink' (solid line). The uplink starts at 500 kbit/s at 0s, jumps to 2000 kbit/s at 2s, and returns to 500 kbit/s at 3s. The downlink starts at 500 kbit/s at 0s, jumps to 2000 kbit/s at 7s, and returns to 500 kbit/s at 8s. Both series remain at 500 kbit/s until 10s. A label 'G.1051(23)' is in the bottom right corner.
+
+**Figure I.5 – Example of traffic pattern 'interactive remote meeting'**
+
+The chosen packet size is 1000 bytes, which is typical for video content. The packet sending frequency is then derived to be 62 packets/s during the sustainable phases and 250 packets/s in the high bit rate phases. An example for a 'video chat HD' application is a similar use case, but it relies on live camera video and transmitting the participant videos in high resolution and the main focus is visual interaction and feedback between people. According to real video chat applications, there is a short initial (set-up) phase followed by a sustainable phase where the video link is established.
+
+![Figure I.6: Traffic pattern 'Video chat HD'. A line graph showing data rate in kbit/s over time in seconds. The y-axis ranges from 0 to 2000 kbit/s in increments of 200. The x-axis ranges from 0 to 10 seconds in increments of 1. The graph shows a single data series labeled 'up-and downlink'. The series starts at 500 kbit/s at 0s, jumps to 1000 kbit/s at 2s, and remains at 1000 kbit/s until 10s. A label 'G.1051(23)' is in the bottom right corner.](45329c7d9aa2bd1290af5b2027f08d7e_img.jpg)
+
+Figure I.6: Traffic pattern 'Video chat HD'. A line graph showing data rate in kbit/s over time in seconds. The y-axis ranges from 0 to 2000 kbit/s in increments of 200. The x-axis ranges from 0 to 10 seconds in increments of 1. The graph shows a single data series labeled 'up-and downlink'. The series starts at 500 kbit/s at 0s, jumps to 1000 kbit/s at 2s, and remains at 1000 kbit/s until 10s. A label 'G.1051(23)' is in the bottom right corner.
+
+**Figure I.6 – Example of traffic pattern 'video chat HD'**
+
+The chosen packet size is again 1000 bytes, which is typical for video content. The packet sending frequency is then derived to be 62 packets/s during the sustainable phases and 125 packets/s in the high bit rate phases. The traffic pattern is symmetrical, meaning the packet size and frequency are the same for uplink and downlink.
+
+The applicable delay budget is identical for both types of video application. In [3GPP TS 23.501], a maximal one-way latency for conversational video of 150 ms is defined (5QI class 2), the two-way latency therefore should not exceed 300 ms and this value forms the delay budget for this test case.
+
+These two examples of applications and traffic shapes have similar constraints regarding perceived interactivity and as an example, the applicable interactivity uses the same parameters for both applications and traffic shapes.
+
+For parametrization of the interactivity model as described in clause 9.2.2, the following principles are used: While running a video chat with interactions and feedback, a two-way delay of 100 ms can be seen as the length of a spoken syllable, a beginning degradation is anticipated for this range (90 of 100 for the interactivity score). The interactions become very difficult in case of a response delay  $> 250$  ms.
+
+It is further expected that while using an interactive remote meeting, a user may have more relaxed expectations on packet delay variations than for e-gaming but is more sensitive in case of lost or disqualified packets because video meetings are usually based on unreliable transmission and missed frames are visible as image distortions.
+
+To reflect this, it is anticipated that a  $PDV_{SQ}$  of 25 ms reduces the interactivity as defined by latency by another 10% ( $D_{PDV} = 0.9$ ) and a ratio of disqualified packets of 1% reduces the perceived interactivity already by 30% ( $D_{DQ} = 0.7$ ).
+
+The parametrization of the model is resulting in:
+
+| Parameter | $f_{max}$ | $a$ | $b$ | $u$ | $v$ |
+|-----------|-----------|-----|-----|-----|-----|
+| Value     | 100       | 215 | 50  | 150 | 30  |
+
+![Figure I.7: A line graph titled 'Interactivity score 'RemoteMeeting', 'Video Chat HD''. The y-axis is 'Interactivity score' from 0 to 100. The x-axis is 'RTT/ms' from 0 to 400. Three curves are shown: a solid line (baseline), a dashed line for PDV_SQ = 25 ms, and a dotted line for P_DQ = 1%. All curves decrease as RTT increases. The dotted line is the lowest, followed by the dashed line, and then the solid line.](0245dc88c1db93181871e732bc0655dd_img.jpg)
+
+The graph shows the interactivity score for 'RemoteMeeting' and 'Video Chat HD' as a function of RTT/ms. The baseline curve (solid line) starts at 100 at 0 ms RTT. The curve for  $PDV_{SQ} = 25$  ms (dashed) starts at 90. The curve for  $P_{DQ} = 1\%$  (dotted) starts at 70. All curves converge towards 0 as RTT approaches 400 ms.
+
+| RTT/ms | Baseline (Solid) | $PDV_{SQ} = 25$ ms (Dashed) | $P_{DQ} = 1\%$ (Dotted) |
+|--------|------------------|-----------------------------|-------------------------|
+| 0      | 100              | 90                          | 70                      |
+| 100    | 95               | 85                          | 65                      |
+| 200    | 80               | 65                          | 45                      |
+| 300    | 45               | 35                          | 20                      |
+| 400    | 10               | 8                           | 5                       |
+
+Figure I.7: A line graph titled 'Interactivity score 'RemoteMeeting', 'Video Chat HD''. The y-axis is 'Interactivity score' from 0 to 100. The x-axis is 'RTT/ms' from 0 to 400. Three curves are shown: a solid line (baseline), a dashed line for PDV\_SQ = 25 ms, and a dotted line for P\_DQ = 1%. All curves decrease as RTT increases. The dotted line is the lowest, followed by the dashed line, and then the solid line.
+
+**Figure I.7 – Example parametrization for remote meeting and video chat according to Annex A**
+
+## Appendix II
+
+## Parameter implementation according to Annex A based on subjective results for cloud gaming considering a real example application on client and server
+
+(This appendix does not form an integral part of this Recommendation.)
+
+### II.1 Introduction
+
+Subjective tests show that subjects are less sensitive to delay and delay jitter in a real gaming situation than the 3GPP thresholds define. There can be many reasons, but in subjective testing the actual application on server and client are considered.
+
+Even though the model described in Annex A is based on measurements on the transport layer and the measurements do not consider the application itself, the model in Annex A can be parametrized to approximate the subjective perception as in subjective tests.
+
+The given examples in this Appendix II are parametrized by a real gaming situation, while the parameters in Appendix I are based on QoS limits. The subjects played a CS\_GO FPS game of 90 seconds match rounds over a Steam Link connection. Consequently, the example parameters in this appendix differ from those given in Appendix I, because the model approximate subjective scores include a real application and its gaming situation.
+
+### II.2 Traffic patterns
+
+#### II.2.1 Packet pattern temporal structure
+
+The recorded packets show that the pattern is mostly tied to the video and audio frame rate. The 120 Hz frame rate and the 50 Hz audio frame rate have the shortest common period of 100 ms, when 12 videoframes and five audio frames are transmitted. This has been noticed from the fact that periodical video and audio frame bursts are transmitted one after each other with a common denominator period of 100 ms. However, the common period can be approximated quite accurately with a 40 ms period comprising five video frames and two audio frames.
+
+The packets recorded on DL show that a video frame is represented by six packets and audio frame by two packets when now network impairments was applied. The last packets of each of these two packet burst types (video frames, audio frames) vary typically between 500 and 800 bytes, and the other packets are of full MTU size. The total size should depend on codecs, resolution and compression rate.
+
+From both DL and UL recorded packets it can also be seen that there is in both directions an acknowledgement mechanism causing transmission of smaller single packets in between bursts.
+
+In addition to the transmission of the apparent acknowledgements, the recorded UL packets show that the frame rate is present, and it shows that user input is transmitted at this rate.
+
+UL packet recording also shows a packet appearing approximately at 50 Hz, which likely is audio input from the user's microphone.
+
+It should be noted that modern algorithms for prioritizing traffic in network nodes analyse the pattern of the traffic. Therefore, in order to closely mimic the real cloud game service, it is important that the traffic characteristics reflect the presence of audio and video streams and the extra packets indicating a real-time transmission.
+
+Table II.1 presents the DL and UL packets patterns basic characteristics represented by packet size and number, based on the analysis of the recorded UL and DL packets described above.
+
+**Table II.1 – Packets patterns characteristics**
+
+| <b>Network condition: No degradations</b> |        |           |        | <b>Network condition: worst case</b> |        |           |        |
+|-------------------------------------------|--------|-----------|--------|--------------------------------------|--------|-----------|--------|
+| <b>UL</b>                                 |        | <b>DL</b> |        | <b>UL</b>                            |        | <b>DL</b> |        |
+| Packets/s                                 | kbit/s | Packets/s | kbit/s | Packets/s                            | kbit/s | Packets/s | kbit/s |
+| ~150                                      | ~140   | ~1100     | ~10000 | ~700                                 | ~620   | ~600      | ~3500  |
+
+As already mentioned above, dividing the packet pattern into temporal sub-segments of 40 ms is expected to be accurate enough. However, to handle the different number of packets per link direction the protocol of choice needs to support, or be extended to support, the concept of bursts (in this case frames) instead (or in addition to) of the single packet concept. This results in two-way measurements such as RTT on the frame burst level instead of the single packet level, but only for the first packet on the respective link.
+
+### II.3 Guidance for adaptation
+
+#### II.3.1 Number of adaptations per link
+
+The different packet patterns for DL can be created by adjusting the number of packets representing the video where the traffic is represented by one to five packets of MTU size. Consequently, the DL can be represented by five patterns.
+
+Packet loss (PL) affects the packet patterns by increasing packets per second and bit/s from the server or from the client. Only a high PL significantly affects the amount of extra traffic, but the interactivity reaches very low subjective interactivity at far lower packet losses and thus the PL impact on the packet pattern can be ignored. The exception would be when RTT is low enough (depending on service's settings) for a re-transmission mechanism to handle high rates of PL with much smaller impact on interactivity. However, that low RTT is not the case for today's mobile networks when the service is running at 120 Hz, and thus that exception case can also be ignored.
+
+For UL the effect of packet loss is much more dramatic, a 5% packet loss rate can yield a doubled packet/bit rate. However, the UL traffic is, compared with DL, using much less of the maximum capacity of the link, and therefore UL adaptation for PL can be ignored.
+
+Large spikes in the delay were in the recorded traffic observed to cause a large increase in uplink traffic, possibly warranting a different packet pattern in those cases. Generally though, the traffic amount is still low versus the link capacity and that UL traffic is still, compared with DL, using much less of the maximum capacity of the link. Thus, the UL adaptation for jitter spikes can be ignored.
+
+#### II.3.2 Adaptation pace
+
+The adaptation of the packet patterns should correspond to the adaptation during the active gaming time (game match) of 90 seconds (value used in the subjective test). A resolution for the measurements on gaming performance over mobile networks within the context of a drive test, needs to ensure a balance between the following:
+
+- drive test real-time characteristic
+- feasible (practical) adaptation scheme of the tested service to the network conditions
+- expected behavioural changes of the tested service's (aka gaming) interactivity depending on the network conditions
+
+Based on these, a measurement time window of 10 s is reasonable. During the 10 s a 40 ms (or 100 ms as mentioned above) packet pattern is played repeatedly. Within each time window of 10 s, a decision on the adaptation is made after 8–9 s based on the network condition.
+
+### II.4 Parameters for approximation subjective scores for cloud gaming
+
+#### II.4.1 Interactive subjective test
+
+For parametrization of the interactivity model as described in Annex A subjective scores are used in accordance with clause 9.2.1.
+
+The basis of parametrization is an interactive subjective test set-up in a lab-controlled environment. The test used 31 subject gamers (males=29 and females=2) who met the requirement of having experience with playing games, either on computers or smartphones, and of being of age 18 or older. The subjects provided answers to the cloud gaming questionnaire as defined in [b-ITU-T G.1072].
+
+The subjects played a CS\_GO FPS game of 90 seconds match rounds. The reason for the game selection relies on the fact that the scope is to provide a generic quality testing solution for one of the most popular video gaming genres played on mobile devices, using technology typical for delivering these, and at the same time addressing the most demanding video game genres for mobile networks in the sense of being most sensitive to the mobile network performance. In this way operators can optimize and troubleshoot their network for the worst scenarios, and thus pre-empt and avoid customer dissatisfaction for both the most demanding as well as the less demanding games.
+
+For each gamer, each of the match rounds have been altered by 30 individual network conditions defined by a set of network metrics. Both the network metrics as well as their values and combinations are selected to meaningfully describe the impact of the mobile network performance on the cloud gaming service based on an interactive subjective pre-test run with a small number of gamers, different from the group used in the full-scale test. The following network metrics are defined as follows:
+
+- i) **RTT (delay)** as the median time the system delivers and receives back a packet, referred to as "static" delay.
+- ii) **Jitter** defined as two types of delay variations which show different effect on the Steam Link streaming.
+  - **Random jitter** frequent with small delay changes (IPDV) from packet to packet.
+  - **Jitter spikes** characterized by amplitude values  $\geq 50$  ms and possibility of frequency between 0.01–1 Hz.
+- iii) **Packet loss** as lost packets during transmission or packets which cannot leave the reflecting server due to downlink congestion and being discarded by the server after timeout.
+
+The network conditions have been created using NetEm emulators and a summary is presented in Table II.2.
+
+**Table II.2 – Mobile network conditions**
+
+| Network metric           | No. of conditions | Values                                                                                 |
+|--------------------------|-------------------|----------------------------------------------------------------------------------------|
+| RTT                      | 7                 | 2*, 25, 50, 100, 200, 300, 400 ms                                                      |
+| PL (per link)            | 4                 | 0, 5, 25, 45% with RTT=2 ms*                                                           |
+| PL (per link) with RTT   | 9                 | PL (0.2, 1, 5%), each with RTT/(25, 50, 100 ms)                                        |
+| Jitter spikes (per link) | 6                 | Jitter spikes with amplitudes values of (25, 100, 750 ms), applied every (5, 15, 45 s) |
+| Random jitter (per link) | 4                 | Avg=25 ms, stdev=3, 6, 9, 12 ms                                                        |
+
+\* An RTT of 2 ms is used as reference for a "clean" condition to be simulated with NetEm.
+
+The target value used for the function parameterization as in Annex A for the cloud gaming over mobile networks use case is selected to be the answer to the question regarding the overall QoE [b-ITU-T G.1072]. The decision for this approach is based on the outcome of an interactive test for
+
+which the results show that the perceived overall QoE describes the interactivity experience as impacted by all the gaming quality dimensions. In addition, this is also empowered by the usage of a specific game with a specific resolution which is acting as a normalization to a reference video-audio quality, and consequently making the overall QoE an interactivity score.
+
+#### II.4.2 Function parametrization according to Annex A
+
+The principal formula for perceived interactivity is as described in Annex A
+
+$$IntAct = I_L \times D_{PDV} \times D_{DQ}$$
+
+The parameter  $I_L$  is calculated as  $I_{L-CG}$  by
+
+$$I_{L-CG} = \frac{f_{max}}{f_0} \left( 1 - \frac{1}{1 + e^{-\frac{1}{b}(RTT_{MEDIAN} - a)}} \right)$$
+
+with  $RTT_{MEDIAN}$  = Median delay of all packets sent by the application
+
+The consideration of packet delay jitter is considered by standard deviation if IPDV is used. By standard deviation is meant the average of standard deviation of IPDV on DL and standard deviation of IPDV on UL.
+
+$$IPDV(i) = D(i) - D(i-1), \text{ and}$$
+
+$$D_{IPDV} = 1 - \frac{IPDV_{STDEV}}{u}$$
+
+Finally, the effect of packet loss is modified compared to Annex A, because the 3GPP RTT specified limit (RTT = 100 ms) does not reflect when interaction with the service (cloud gaming in this case) is not possible per se, since packets are rarely late for a critical moment, and users adapt to latency which anyway is handled by  $I_L$ .
+
+The proposed modification is to consider a limit of 100 ms for disqualification on large jitter (IPDV) values in order to capture the fact that large delay spikes disrupt the ability to interact. The reasoning for this is that tests showed that delay spikes start to affect at 50 ms and can have very noticeable effect at 1500 ms, and these jitter spikes are not captured by the median value of PDV.
+
+In addition, it is proposed that DQ term is used to describe the packet loss. Therefore, the  $D_{DQ}$  term becomes:
+
+$$D_{DQ-CG} = 1 - v \times P_{DQ}$$
+
+$$\text{with } P_{DQ} = \frac{P_{JS}}{T_{MeasureWindow}} + \overline{P_{L-CS} + P_{L-SC}}$$
+
+$$\text{and } P_{JS} = \max(IPDV) \text{ , if } \max(IPDV) \geq DQ_{LIMIT}$$
+
+$$= 0, \text{ otherwise}$$
+
+where by JS is denoted the jitter spike, and  $DQ_{LIMIT}=50$  ms
+
+These modification results in a combining formula as
+
+$$IntAct \text{ for } CG = f_{offset} + f_{max} \times I_{L-CG} \times D_{IPDV} \times D_{DQ-CG}$$
+
+The parameters  $a$ ,  $b$ ,  $u$  and  $v$  to be applied for approximating scores as obtained in the introduced subjective test set-up are:
+
+| Parameter | $a$ | $b$ | $u$ | $v$ |
+|-----------|-----|-----|-----|-----|
+| Value     | 213 | 91  | 25  | 7   |
+
+![Figure II.1: Interactivity score 'CloudGaming' graph. The Y-axis is 'Interactivity score (ACR)' from 1.0 to 5.0. The X-axis is 'RTT/ms' from 0 to 600. Three curves are shown: a solid line for P_DQ-CG = 2%, and two dashed lines for IPDV_STDDEV = 5 ms. All curves show a decreasing trend as RTT increases.](a2dcc4a0703102026ec86e82caa4985e_img.jpg)
+
+The graph titled "Interactivity score 'CloudGaming'" shows the relationship between RTT/ms (X-axis, 0 to 600) and Interactivity score (ACR) (Y-axis, 1.0 to 5.0). Three curves are plotted: a solid line representing  $P_{DQ-CG} = 2\%$ , and two dashed lines representing  $IPDV_{STDDEV} = 5\text{ ms}$ . All curves show a decreasing trend as RTT increases, starting from an ACR of 5.0 at 0 ms RTT and approaching 1.0 at 600 ms RTT.
+
+| RTT/ms | $P_{DQ-CG} = 2\%$ (Solid Line) | $IPDV_{STDDEV} = 5\text{ ms}$ (Dashed Lines) |
+|--------|--------------------------------|----------------------------------------------|
+| 0      | 5.0                            | 4.7                                          |
+| 100    | 4.5                            | 4.0                                          |
+| 200    | 3.8                            | 3.2                                          |
+| 300    | 3.0                            | 2.4                                          |
+| 400    | 2.3                            | 1.8                                          |
+| 500    | 1.8                            | 1.4                                          |
+| 600    | 1.5                            | 1.1                                          |
+
+G.1051(23)
+
+Figure II.1: Interactivity score 'CloudGaming' graph. The Y-axis is 'Interactivity score (ACR)' from 1.0 to 5.0. The X-axis is 'RTT/ms' from 0 to 600. Three curves are shown: a solid line for P\_DQ-CG = 2%, and two dashed lines for IPDV\_STDDEV = 5 ms. All curves show a decreasing trend as RTT increases.
+
+**Figure II.1 – Example of interactivity score for 'cloud gaming'**
+
+It should be noted that  $f_{offset}$  is set to 1.0 and  $f_{max}$  to 4.0 to scale the output into a five-point ACR scale as in the underlying subjective test.
+
+## Bibliography
+
+- [b-ITU-T G.1072] Recommendation ITU-T G.1072 (2020), *Opinion Model Predicting Gaming Quality Of Experience For Cloud Gaming Services*.
+- [b-3GPP TS 22.125] 3GPP TS 22.125 (2019), *Unmanned Aerial System (UAS) support in 3GPP*.
+- [b-IETF] IETF Draft IPPM Capacity Protocol (2022), *Test protocol for one-way IP capacity measurement*. <https://datatracker.ietf.org/doc/html/draft-ietf-ippm-capacity-protocol-04>
+- [b-OB-UDPST] OB-UDPST (2023), OB-UDPST. <https://github.com/BroadbandForum/obudpst>
+
+
+
+
+
+## SERIES OF ITU-T RECOMMENDATIONS
+
+|                 |                                                                                                                                                           |
+|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Series A        | Organization of the work of ITU-T                                                                                                                         |
+| Series D        | Tariff and accounting principles and international telecommunication/ICT economic and policy issues                                                       |
+| Series E        | Overall network operation, telephone service, service operation and human factors                                                                         |
+| Series F        | Non-telephone telecommunication services                                                                                                                  |
+| <b>Series G</b> | <b>Transmission systems and media, digital systems and networks</b>                                                                                       |
+| Series H        | Audiovisual and multimedia systems                                                                                                                        |
+| Series I        | Integrated services digital network                                                                                                                       |
+| Series J        | Cable networks and transmission of television, sound programme and other multimedia signals                                                               |
+| Series K        | Protection against interference                                                                                                                           |
+| Series L        | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant |
+| Series M        | Telecommunication management, including TMN and network maintenance                                                                                       |
+| Series N        | Maintenance: international sound programme and television transmission circuits                                                                           |
+| Series O        | Specifications of measuring equipment                                                                                                                     |
+| Series P        | Telephone transmission quality, telephone installations, local line networks                                                                              |
+| Series Q        | Switching and signalling, and associated measurements and tests                                                                                           |
+| Series R        | Telegraph transmission                                                                                                                                    |
+| Series S        | Telegraph services terminal equipment                                                                                                                     |
+| Series T        | Terminals for telematic services                                                                                                                          |
+| Series U        | Telegraph switching                                                                                                                                       |
+| Series V        | Data communication over the telephone network                                                                                                             |
+| Series X        | Data networks, open system communications and security                                                                                                    |
+| Series Y        | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities                               |
+| Series Z        | Languages and general software aspects for telecommunication systems                                                                                      |
\ No newline at end of file
diff --git a/marked/G/T-REC-G.169-201105-I_PDF-E/raw.md b/marked/G/T-REC-G.169-201105-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..02bbc1fcfed973f93428bee0ce49fadb28b134ad
--- /dev/null
+++ b/marked/G/T-REC-G.169-201105-I_PDF-E/raw.md
@@ -0,0 +1,837 @@
+
+
+**ITU-T**
+
+TELECOMMUNICATION  
+STANDARDIZATION SECTOR  
+OF ITU
+
+**G.169**
+
+(05/2011)
+
+SERIES G: TRANSMISSION SYSTEMS AND MEDIA,  
+DIGITAL SYSTEMS AND NETWORKS
+
+International telephone connections and circuits –  
+Apparatus associated with long-distance telephone circuits
+
+# --- Automatic level control devices
+
+Recommendation ITU-T G.169
+
+![ITU logo: A globe with a red lightning bolt and the text 'ITU International Telecommunication Union'](84a1d09fb489061482111515543b60dc_img.jpg)
+
+ITU logo: A globe with a red lightning bolt and the text 'ITU International Telecommunication Union'
+
+## ITU-T G-SERIES RECOMMENDATIONS **TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS**
+
+|                                                                                                                                              |                    |
+|----------------------------------------------------------------------------------------------------------------------------------------------|--------------------|
+| INTERNATIONAL TELEPHONE CONNECTIONS AND CIRCUITS                                                                                             | G.100–G.199        |
+| Transmission planning and the E-model                                                                                                        | G.100–G.109        |
+| General Recommendations on the transmission quality for an entire international telephone connection                                         | G.110–G.119        |
+| General characteristics of national systems forming part of international connections                                                        | G.120–G.129        |
+| General characteristics of the 4-wire chain formed by the international circuits and national extension circuits                             | G.130–G.139        |
+| General characteristics of the 4-wire chain of international circuits; international transit                                                 | G.140–G.149        |
+| General characteristics of international telephone circuits and national extension circuits                                                  | G.150–G.159        |
+| <b>Apparatus associated with long-distance telephone circuits</b>                                                                            | <b>G.160–G.169</b> |
+| Transmission plan aspects of special circuits and connections using the international telephone connection network                           | G.170–G.179        |
+| Protection and restoration of transmission systems                                                                                           | G.180–G.189        |
+| Software tools for transmission systems                                                                                                      | G.190–G.199        |
+| GENERAL CHARACTERISTICS COMMON TO ALL ANALOGUE CARRIER-TRANSMISSION SYSTEMS                                                                  | G.200–G.299        |
+| INDIVIDUAL CHARACTERISTICS OF INTERNATIONAL CARRIER TELEPHONE SYSTEMS ON METALLIC LINES                                                      | G.300–G.399        |
+| GENERAL CHARACTERISTICS OF INTERNATIONAL CARRIER TELEPHONE SYSTEMS ON RADIO-RELAY OR SATELLITE LINKS AND INTERCONNECTION WITH METALLIC LINES | G.400–G.449        |
+| COORDINATION OF RADIOTELEPHONY AND LINE TELEPHONY                                                                                            | G.450–G.499        |
+| TRANSMISSION MEDIA AND OPTICAL SYSTEMS CHARACTERISTICS                                                                                       | G.600–G.699        |
+| DIGITAL TERMINAL EQUIPMENTS                                                                                                                  | G.700–G.799        |
+| DIGITAL NETWORKS                                                                                                                             | G.800–G.899        |
+| DIGITAL SECTIONS AND DIGITAL LINE SYSTEM                                                                                                     | G.900–G.999        |
+| MULTIMEDIA QUALITY OF SERVICE AND PERFORMANCE – GENERIC AND USER-RELATED ASPECTS                                                             | G.1000–G.1999      |
+| TRANSMISSION MEDIA CHARACTERISTICS                                                                                                           | G.6000–G.6999      |
+| DATA OVER TRANSPORT – GENERIC ASPECTS                                                                                                        | G.7000–G.7999      |
+| PACKET OVER TRANSPORT ASPECTS                                                                                                                | G.8000–G.8999      |
+| ACCESS NETWORKS                                                                                                                              | G.9000–G.9999      |
+
+*For further details, please refer to the list of ITU-T Recommendations.*
+
+## Recommendation ITU-T G.169
+
+# Automatic level control devices
+
+# Summary
+
+Recommendation ITU-T G.169 applies to the testing of automatic level control (ALC) devices intended for use in digital network-based equipment. It does not apply to subscriber-based level control devices, devices that operate in the analogue domain, or any means of fixed level control within the network which may be part of an overall network transmission plan.
+
+The scope of this Recommendation is to define certain performance constraints for network ALC devices and, where appropriate, to define laboratory tests that may be performed on an ALC device to verify that these constraints are met.
+
+An ALC device that satisfies all the constraints and passes all of the tests in this Recommendation should ensure (but will not guarantee) that the pre-existing standard of overall network performance (e.g., the transmission of speech, voiceband data and other voiceband signals, ISDN, etc.) is not degraded when the ALC device is installed in the network.
+
+This Recommendation also describes the general characteristics of ALC devices and indicates what characteristics are important to provide acceptable performance in the network. Issues relating to the interaction of ALC devices with other network and subscriber equipment are also discussed in this Recommendation.
+
+This Recommendation does not define a standard algorithm.
+
+This Recommendation does not define planning rules, deployment aspects, or target levels for ALC devices.
+
+# History
+
+| Edition | Recommendation | Approval   | Study Group |
+|---------|----------------|------------|-------------|
+| 1.0     | ITU-T G.169    | 1999-07-02 | 15          |
+| 2.0     | ITU-T G.169    | 2011-05-14 | 16          |
+
+# FOREWORD
+
+The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis.
+
+The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics.
+
+The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1.
+
+In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC.
+
+## NOTE
+
+In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party.
+
+# INTELLECTUAL PROPERTY RIGHTS
+
+ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process.
+
+As of the date of approval of this Recommendation, ITU had received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at <http://www.itu.int/ITU-T/ipr/>.
+
+© ITU 2012
+
+All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU.
+
+# Table of Contents
+
+###### Page
+
+|      |                                                                                                                                                               |    |
+|------|---------------------------------------------------------------------------------------------------------------------------------------------------------------|----|
+| 1    | Scope .....                                                                                                                                                   | 1  |
+| 2    | References.....                                                                                                                                               | 1  |
+| 3    | Terms and definitions .....                                                                                                                                   | 2  |
+| 4    | Abbreviations and acronyms .....                                                                                                                              | 3  |
+| 5    | Characteristics of ALC devices .....                                                                                                                          | 4  |
+| 5.1  | General .....                                                                                                                                                 | 4  |
+| 5.2  | ALC characteristics .....                                                                                                                                     | 4  |
+| 5.3  | Tandemed operation .....                                                                                                                                      | 4  |
+| 5.4  | Delay performance .....                                                                                                                                       | 4  |
+| 6    | Test signals .....                                                                                                                                            | 5  |
+| 6.1  | Test signal for level and gain checks.....                                                                                                                    | 5  |
+| 6.2  | Electrical circuit noise .....                                                                                                                                | 5  |
+| 6.3  | Environmental noise.....                                                                                                                                      | 5  |
+| 7    | Tests.....                                                                                                                                                    | 6  |
+| 7.1  | Stability.....                                                                                                                                                | 6  |
+| 7.2  | Echo .....                                                                                                                                                    | 8  |
+| 7.3  | Noise tolerance .....                                                                                                                                         | 11 |
+| 7.4  | Signalling tones .....                                                                                                                                        | 13 |
+| 7.5  | Voiceband data and facsimile transmission .....                                                                                                               | 16 |
+| 7.6  | Test to verify the ability of an ALC to estimate the signal level correctly ....                                                                              | 20 |
+| 7.7  | Test to verify the ability of an ALC to operate on short speech utterances<br>(under study).....                                                              | 21 |
+|      | Annex A – Guidance for measuring signal levels in networks.....                                                                                               | 22 |
+|      | Appendix I – Guidance for the design of automatic level control (ALC) algorithms and<br>their placement in the public switched telephone network (PSTN) ..... | 24 |
+| I.1  | Introduction .....                                                                                                                                            | 24 |
+| I.2  | Discussion.....                                                                                                                                               | 24 |
+| I.3  | ALC considerations .....                                                                                                                                      | 25 |
+|      | Appendix II – Considerations relating to ALC deployment.....                                                                                                  | 28 |
+| II.1 | Location of ALC.....                                                                                                                                          | 28 |
+| II.2 | Tandemed operation .....                                                                                                                                      | 29 |
+|      | Bibliography.....                                                                                                                                             | 30 |
+
+
+
+## Recommendation ITU-T G.169
+
+# Automatic level control devices
+
+# 1 Scope
+
+This Recommendation applies to the testing of automatic level control (ALC) devices intended for use in digital network-based equipment.
+
+An ALC device is defined as any signal processing function located in the digital transmission path which automatically adjusts the level of a signal towards a predetermined value. Devices which modify the frequency response or spectral content of the signal in such a way as to affect the overall level of the signal are also defined as ALC devices for the purpose of this Recommendation.
+
+This Recommendation does not apply to subscriber-based level control devices, devices that operate in the analogue domain, or any means of fixed level control within the network which may be part of an overall network transmission plan.
+
+The scope of this Recommendation is to define certain performance constraints for network ALC devices and, where appropriate, to define laboratory tests that may be performed on an ALC device to verify that these constraints are met.
+
+An ALC device that satisfies all the constraints and passes all of the tests in this Recommendation should ensure (but will not guarantee) that the pre-existing standard of overall network performance (e.g., the transmission of speech, voiceband data and other voiceband signals, ISDN, etc.) is not degraded when the ALC device is installed in the network.
+
+This Recommendation also describes the general characteristics of ALC devices and indicates what characteristics are important to provide acceptable performance in the network. Issues relating to the interaction of ALC devices with other network and subscriber equipment are also discussed in this Recommendation.
+
+This Recommendation does not define a standard algorithm.
+
+This Recommendation does not define planning rules, deployment aspects, or target levels for ALC devices. This information may be found in [ITU-T G.136].
+
+# 2 References
+
+The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation.
+
+- [ITU-T G.115] Recommendation ITU-T G.115 (1996), *Mean active speech level for announcement and speech synthesis systems*.
+- [ITU-T G.121] Recommendation ITU-T G.121 (1993), *Loudness ratings (LRs) of national systems*.
+- [ITU-T G.122] Recommendation ITU-T G.122 (1993), *Influence of national systems on stability and talker echo in international connections*.
+- [ITU-T G.136] Recommendation ITU-T G.136 (1999), *Application rules for automatic level control devices*.
+
+- [ITU-T G.160] Recommendation ITU-T G.160 (2008), *Voice enhancement devices.*
+- [ITU-T G.164] Recommendation ITU-T G.164 (1988), *Echo suppressors.*
+- [ITU-T G.165] Recommendation ITU-T G.165 (1993), *Echo cancellers.*
+- [ITU-T G.168] Recommendation ITU-T G.168 (2009), *Digital network echo cancellers.*
+- [ITU-T G.763] Recommendation ITU-T G.763 (1998), *Digital circuit multiplication equipment using G.726 ADPCM and digital speech interpolation.*
+- [ITU-T P.56] Recommendation ITU-T P.56 (1993), *Objective measurement of active speech level.*
+- [ITU-T P.501] Recommendation ITU-T P.501 (2007), *Test signals for use in telephonometry.*
+- [ITU-T P.561] Recommendation ITU-T P.561 (2002), *In-service non-intrusive measurement device – Voice service measurements.*
+- [ITU-T Q.24] Recommendation ITU-T Q.24 (1988), *Multifrequency push-button signal reception.*
+- [ITU-T T.4] Recommendation ITU-T T.4 (2003), *Standardization of Group 3 facsimile terminals for document transmission.*
+- [ITU-T T.30] Recommendation ITU-T T.30 (2005), *Procedures for document facsimile transmission in the general switched telephone network.*
+- [ITU-T V.8] Recommendation ITU-T V.8 (2000), *Procedures for starting sessions of data transmission over the public switched telephone network.*
+- [ITU-T V.25] Recommendation ITU-T V.25 (1996), *Automatic answering equipment and general procedures for automatic calling equipment on the general switched telephone network including procedures for disabling of echo control devices for both manually and automatically established calls.*
+
+# 3 Terms and definitions
+
+This Recommendation defines the following terms:
+
+**3.1 ALC device:** A signal processing function located in the digital transmission path which automatically adjusts the level of a signal towards a predetermined value. Devices which modify the frequency response or spectral content of the signal in such a way as to affect the overall level of the signal are also defined as ALC devices for the purpose of this Recommendation. An ALC device is designed to process signals in one direction of transmission. See Figure 1.
+
+![Block diagram of an ALC device. The diagram shows a dashed box labeled 'ALC Device' containing a 'ALC Processing' block. Above the device, a 'Receive or non-processing path' is shown with an arrow pointing right, connecting 'Receive in' (R_in) to 'Receive out' (R_out). Below the device, a 'Send or processing path' is shown with an arrow pointing left, connecting 'Send in' (S_in) to 'Send out' (S_out). A vertical dashed line with a downward arrow connects the receive path to the 'ALC Processing' block.](ebff22fb5dd6f50a90e44dca0f82f285_img.jpg)
+
+Block diagram of an ALC device. The diagram shows a dashed box labeled 'ALC Device' containing a 'ALC Processing' block. Above the device, a 'Receive or non-processing path' is shown with an arrow pointing right, connecting 'Receive in' (R\_in) to 'Receive out' (R\_out). Below the device, a 'Send or processing path' is shown with an arrow pointing left, connecting 'Send in' (S\_in) to 'Send out' (S\_out). A vertical dashed line with a downward arrow connects the receive path to the 'ALC Processing' block.
+
+**Figure 1 – Block diagram of an ALC device**
+
+**3.2 disabled ALC device:** An ALC device that has been forced into a 64 kbit/s bit-sequence integrity mode of operation, by whatever means.
+
+**3.3 echo canceller:** A device placed in the 4-wire portion of a circuit and used for reducing cancelled-end echo present on the send path by subtracting an estimation of that echo from the cancelled-end echo.
+
+**3.4 full ALC device:** An ALC device designed to process signals in both directions of transmission.
+
+**3.5 full echo canceller:** An echo canceller designed to cancel echoes in both directions (i.e., near-end and far-end echoes).
+
+**3.6 laboratory tests:** Tests which may be performed in a laboratory or any environment where the ALC device is not installed in the network and is therefore not 'in service'.
+
+**3.7 Target level:** For a particular signal type, the input signal level for which an active (enabled) ALC device will progress to unity gain. At other input signal levels, the output level of the ALC device will be adjusted towards the target level.
+
+NOTE – With some ALC devices, the target level may be different for different types of signals, e.g., the target level for speech may be different from the target level for a tone. Also, the treatment of signals which are above the target level may be different from the treatment of signals which are below the target level. In principle, an advanced ALC device may feature more than one target level, depending on the transmitted signal (e.g., speech, data, or DTMF tones).
+
+# 4 Abbreviations and acronyms
+
+This Recommendation uses the following abbreviations:
+
+|      |                                          |
+|------|------------------------------------------|
+| ALC  | Automatic Level Control                  |
+| A/D  | Analogue-to-Digital converter            |
+| CSS  | Composite Source Signal                  |
+| D/A  | Digital-to-Analog converter              |
+| DCME | Digital Circuit Multiplication Equipment |
+| DTMF | Dual-Tone Multi-Frequency                |
+| ERL  | Echo Return Loss                         |
+| ISDN | Integrated Services Digital Network      |
+
+# 5      **Characteristics of ALC devices**
+
+## 5.1      **General**
+
+This Recommendation is applicable to automatic level control (ALC) devices installed in digital network-based equipment. An ALC device is defined as any signal processing function located in the digital transmission path which automatically adjusts the level of a signal towards a predetermined value. Devices which modify the frequency response or spectral content of the signal in such a way as to affect the overall level of the signal are also defined as ALC devices for the purpose of this Recommendation.
+
+## 5.2      **ALC characteristics**
+
+ALC devices installed in the network should have the following characteristics:
+
+- 1)      The ability to introduce restricted gain or loss in the circuit to maintain the level of a call at a predetermined value.
+- 2)      The ability to maintain the stability of a connection at all times (both during call set-up and for the duration of the call), in cases with and without associated echo control.
+- 3)      The ability to maintain proper operation during facsimile and voiceband data transmission.
+- 4)      The ability to operate with realistic levels of background and circuit noise (e.g., mobile networks).
+- 5)      The ability to operate correctly in the presence of echo.
+- 6)      The ability not to interfere with the correct operation of signalling tones used in the network.
+- 7)      The ALC device, when disabled, should provide a 64 kbit/s bit-sequence integrity mode of operation.
+
+## 5.3      **Tandemed operation**
+
+There are significant issues related to the tandemed operation of ALC devices. All tandemed ALC devices should have the capability of being disabled. Methods for disabling ALC devices and the tests to ensure proper operation of tandemed ALC devices are for further study.
+
+## 5.4      **Delay performance**
+
+The delay in the processing path and the non-processing path of an ALC device should be kept to a minimum. For ALC devices used in networks that do not incorporate echo cancellers, the delay in the processing path should be kept to a minimum and should not exceed 1 ms. The delay in the non-processing path of the ALC device should not exceed 250 µs for interface frame alignment. As a result, there should be no additional or incremental processing delay added in the non-processing direction of the ALC function.
+
+For ALC devices used in networks that incorporate echo cancellers, the above constraints on the ALC processing do not apply. This is to allow flexibility in the design of algorithms that may perform functions other than simple ALC, but which are still covered by this Recommendation. In this case, the delay performance of the algorithm in the processing path should be clearly stated. The delay in the non-processing path of the ALC device should not exceed 250 µs for interface frame alignment. As a result, there should be no additional or incremental processing delay added in the non-processing direction of the ALC function. Designers are reminded that the delay in the processing path of all such devices should be kept to a minimum.
+
+# 6 Test signals
+
+## 6.1 Test signal for level and gain checks
+
+The ALC response to speech signals may be significantly different from the response to stationary periodic test signals (e.g., sinusoidal test signals). Consequently, if periodic test signals are used for level and gain measurements, the ALC device must respond to the chosen test signal in the same manner as it would to a speech signal. Otherwise, the results might not represent the actual performance in regard to speech signals. For example, certain ALC devices may respond to particular frequencies by resetting the gain to unity or disabling themselves, in which case the test results are not indicative of its performance with actual speech signals.
+
+Also, some designs of ALC devices do not make gain changes while a continuous signal persists. In this case, it would be necessary to provide a means of turning the modulation of the test signal on or off so that gain changes can occur, but return to continuous signal mode when making the level or gain measurements. In the case of an on/off modulated test signal, references to the level of the signal within this Recommendation relate to the "on" portion of the test signal (i.e., measurements made on the unmodulated signal).
+
+For some ALC device designs, the target level (as defined in clause 3) may be dependent on the characteristics of the applied signal, i.e., the target level with a speech signal may differ, in practice, from the target level with a tone. For such an ALC device, this aspect does not prevent the use of a sine wave signal in the tests described in clause 7.
+
+A suitable test signal must be selected by reference to the specifications for the ALC device under test. In most cases, suitable test signals for level and gain checks would be provided by a set of sinusoids (e.g., 204 Hz, 304 Hz, 504 Hz, 1004 Hz, 1804 Hz and 2804 Hz), on/off modulated, if necessary, at the rate 1 second on/1 second off.
+
+In principle, an advanced ALC device may feature more than one target level depending on the transmitted signal. Such an ALC device would have the ability to discriminate between different signal types, e.g., speech, data, or DTMF tones. In this situation, for tests on the performance of the ALC device with a speech signal, care must be taken that the selected test signal is identified by the ALC device as speech.
+
+Because tone signals may prove unsuitable or inadequate for a particular design of ALC device, consideration is given to the use of band-limited noise as the test signal. Consideration is also given to the use of the composite source signal (CSS) defined in [ITU-T P.501]. As a last resort, pre-recorded speech may be used as the test signal, in conjunction with speech level measurement facilities such as those defined in [ITU-T P.56]. However, the use of speech will make certain tests difficult to perform.
+
+## 6.2 Electrical circuit noise
+
+When required in the tests, electrical circuit noise should be emulated by a continuous, white Gaussian noise signal, band-limited to the frequency range 0-3.4 kHz at source. References to the level of this noise test signal relate to the mean power of the signal, measured flat (i.e., without psophometric weighting). The level, type and time structure of this test signal is for further study.
+
+## 6.3 Environmental noise
+
+When required in the tests, environmental noise should be emulated by a white Gaussian noise signal, band-limited to the frequency range 0-800 Hz at source, and on/off modulated at the rate 1 second on/1 second off. References to the level of this noise test signal relate to the "on" portion of the signal, equivalent to the mean power of the unmodulated signal, measured flat (i.e., without psophometric weighting). The level, type and time structure of this test signal is for further study.
+
+# 7 Tests
+
+In many of the following tests, it is necessary to check the gain of the ALC device at various times to see whether any change in gain has occurred. In the test procedures, it is assumed that the ALC device has no provision that would allow its gain to be interrogated at arbitrary points in time. If a particular ALC device does include such provision, then this feature may be used to simplify aspects of the following tests, and may lead to more accurate results.
+
+The tests relate to ALC devices installed in digital networks; therefore, the tests require the injection and measurement of signals in digital circuits. This implies the use of digital test equipment, or of suitable analogue-to-digital (A/D) and digital-to-analogue (D/A) converters.
+
+In some cases, the ALC device under test may be integrated with, or required to work with, other network equipment such as an echo canceller. This implies a capability to inject and monitor test signals in a primary rate multiplexed bitstream. In the case of echo cancellers, it will be necessary to ensure that these devices are fully converged before conducting any of the following tests. For this purpose, it is recommended that a white Gaussian noise signal at an approximate level of  $-10\text{ dBm}0$  be injected into the test circuit. The noise signal should be applied first to one direction of transmission for a minimum period of 10 seconds, with no signal in the other direction; it should then be removed and applied to the other direction of transmission for at least 10 seconds.
+
+An ALC device adjusts the level of a signal towards a target level. Typically, the target level will be user selectable within a certain range. In networks where the objectives for send loudness rating (SLR) and receive loudness rating (RLR) are 8 dB and 2 dB respectively (i.e., at the mid-point of the long term objectives for these loudness ratings specified in [ITU-T G.121]), the desired target level with a speech signal is  $-19\text{ dBm}0$ . This level is based on the approximate relationship between SLR and speech level presented in [ITU-T G.115]. In some devices, the target level will be dependent on the characteristics of the input signal (e.g., the target level with a speech signal may be different from the target level with a tone). In the following test procedures, references to "target level" relate to the target level appropriate to the particular test signal in use (i.e., the level of the test signal at the input to the ALC device that would cause the device to progress to unity gain).
+
+In the tests, it is assumed that the same target level is used in all the individual tests. The selected target level should be realistic in terms of network level objectives, bearing in mind that, for some ALC devices, the target level may be dependent on the nature of the test signal. The use of unrealistic target levels may invalidate some of the tests. Compliance tests on a device should record the target level adopted, and the type of signal to which this target level relates.
+
+## 7.1 Stability
+
+Network stability issues are addressed in [ITU-T G.122]. With regard to 4-wire circuits with 2-wire end paths, it is normal practice to ensure (as far as is practicable) that there is always a net loss associated with the 4-wire loop. In this way, stability is achieved even for conditions of severe impedance mismatch at the 2-wire/4-wire terminating units.
+
+ALC devices that can introduce significant amounts of gain threaten to reduce or cancel the stability margin of a connection, particularly if ALC is installed in both directions of transmission. The problem is further exacerbated if cascaded ALC systems are permitted. The maximum gain introduced by ALC systems must be restricted to prevent instability, having regard to worst-case conditions for a connection.
+
+ALC may be deployed in two separate network scenarios:
+
+- a) networks without pre-existing echo control;
+- b) networks with echo control.
+
+Stability issues associated with full echo cancellation are not discussed in this clause – refer to clause II.1.
+
+### 7.1.1 Networks without pre-existing echo control
+
+Typically, networks without echo control will be national networks where the maximum transmission delays encountered are small and do not justify the use of echo control equipment. In the short term, ALC systems will rarely be deployed in such networks since they are unlikely to have suitable signal processing platforms installed, so making the provision of ALC economically unattractive. However, the possibility of ALC systems being deployed in the future should not be neglected.
+
+It is possible that an ALC device may include in-built echo cancellation, in which case the stability issue becomes as discussed in 7.1.2, "Networks with echo control".
+
+If the ALC device does not incorporate echo cancellation, it is recommended that the maximum gain that the ALC system is permitted to introduce in a network without echo control is restricted to satisfy the requirements of [ITU-T G.122]. For some national networks, this implies that the network operator should ensure that the maximum gain introduced by an ALC device does not exceed 0 dB. This is likely to be the case where Administrations already compensate for the loss of long local lines by reducing the R and T pad losses<sup>1</sup>.
+
+### 7.1.2 Networks with echo control
+
+International connections and the national networks of large countries usually employ echo control devices to reduce the level of reflected echo signals. In the following discussion on ALC device gain and stability, it is assumed that the ALC device is installed at a point in the transmission path after an echo control device (i.e., not within the echo path). It is further assumed that the echo control device is an echo canceller, [ITU-T G.165] and [ITU-T G.168].
+
+It must not be assumed that the arguments presented below hold true if the echo control device is an echo suppressor, since these devices provide a much lower value of echo attenuation during double-talk situations. In certain conditions of send and receive levels defined in [ITU-T G.164], there may be no echo attenuation provided by a suppressor. Therefore, it is recommended that networks with echo suppressors should be regarded as providing no additional margin against instability. Accordingly, the recommended maximum ALC device gain is as discussed in 7.1.1, "Networks without pre-existing echo control".
+
+An echo canceller, once fully converged, will greatly attenuate the reflected echo signal arriving at its send in port ( $S_{in}$ ). Since the stability of a closed loop is dependent on the sum of the gains and losses as seen by a signal circulating in that loop, the echo attenuation provided by an echo canceller can significantly increase the stability margin of the loop. Traditionally, however, loop stability is not dependent on the echo attenuation provided by an echo canceller.
+
+Loop stability may be considered for a connection with echo cancellation at both ends of the link, and a single ALC device installed in the echo-cancelled path in each direction of transmission. In this scenario, the maximum gain of an ALC device without causing instability could be made equal to the lowest value of echo attenuation across the telephone bandwidth achieved in practice by an echo canceller. However, due regard must be given to stability at the start of a call, before the echo canceller has converged. With this aspect in mind, it is advised that the ALC device should ideally be reset to unity gain at the start of a call. Other values of initial gain are permissible, but under no circumstances should this value exceed +4 dB. Furthermore, the ALC device gain should not increase at a rate of more than 10 dB/s. (Recognizing that some ALC devices implement step gain changes, the rate of change of gain should be taken to imply the maximum total increase in gain that
+
+---
+
+<sup>1</sup> The R pad represents the transmission loss between the 0 dBr point at the digital-to-analogue decoder and the 2-wire side of the 2-wire/4-wire terminating unit. Similarly, the T pad represents the transmission loss between the 2-wire side of the 2-wire/4-wire terminating unit and the 0 dBr point at the analogue-to-digital coder.
+
+can be induced in the device over a one-second interval, where this interval contains the first gain adjustments occurring after a device reset.)
+
+Taken together with the above recommendations regarding ALC device reset and rate of change of gain, it is recommended that the maximum gain of an ALC device in a connection with echo cancellation should not exceed +15 dB.
+
+## 7.2 Echo
+
+If suitable precautions are not taken, an ALC device may show an undesirable tendency to adjust its gain in response to the level of echo signals. This is particularly relevant if automatic level control is to be used on low delay circuits without echo cancellation; the gain may adjust in response to the reflected signal even though this signal is not heard as an echo.
+
+Practical ALC device designs may include a fixed or adaptive threshold level, below which a signal will not elicit a gain response from the device. When used in a connection with echo cancellation, such a design would probably be effective in preventing ALC gain changes in response to the level of the residual echo signal. In a connection without echo cancellation, other precautions would be necessary to prevent the ALC gain adjusting in response to echo signals.
+
+Other ALC device designs may not be based on level thresholds. Instead, these designs may use signal processing to discriminate between speech and non-speech signals. In this way, the ALC gain would be permitted to adjust to the level of a speech signal but not, for example, to noise. If no other precautions are taken, a design of this nature may show a strong tendency to adjust in response to echo signals, particularly if used in a connection without echo cancellation.
+
+From the above discussion, in a connection without echo cancellation, satisfactory ALC device performance in respect of echo will require a means of identifying the echo signals. This implies that an ALC device in such a connection would need to be connected to both the transmit path and the receive path.
+
+To verify satisfactory performance of an ALC device with respect to echo signals, one of the two tests described below should be conducted. "Test A" applies to an ALC device installed in a connection without echo control. "Test B" applies where an ALC device is used in a connection with echo control, (including the case where ALC is integrated with an echo canceller).
+
+### Test A (for connections without echo control)
+
+![Circuit configuration for 'Test A' – ALC echo robustness for connections without echo control.](c036e2540a94b31357ceb0002f0cacab_img.jpg)
+
+The diagram shows a circuit configuration. A signal enters at point B and passes through a block labeled 'Echo Path Delay'. From there, it goes to a block labeled 'ERL 6 dB'. The output of the ERL block goes into a summing junction (circle with a plus sign). Another signal enters at point A and goes into the same summing junction. The output of the summing junction goes to point C. An ALC block is positioned between the path from B and the path to C. A dashed line connects the path after the 'Echo Path Delay' block to the ALC block. The ALC block then connects to the path leading to point C. The diagram is labeled T1530240-98.
+
+Circuit configuration for 'Test A' – ALC echo robustness for connections without echo control.
+
+**Figure 2 – Circuit configuration for "Test A" – ALC echo robustness  
+for connections without echo control**
+
+- 1) Connect the ALC device into an emulation of part of a connection, including the anticipated worst-case echo path delay contributing to the signal arriving at the input port of the ALC device. A basic test-circuit configuration is shown in Figure 2. The echo return loss (ERL) value of 6 dB is chosen to represent worst-case echo conditions.
+
+- 2) Apply a test signal (on/off modulated if necessary; see clause 6) to point A of Figure 2, at a level of  $-2 \text{ dBm}_0$ . This level is sufficiently high to ensure that the ALC device gain is driven to (or near) its minimum value.
+- 3) Measure the level of the signal at point C of Figure 2, and from this derive the value of the ALC device gain.
+- 4) Remove the test signal from point A. Apply a test signal to point B of Figure 2 at the specified or pre-set target level of the ALC device under test. Note that with some ALC devices, the target level may be different for different types of signals.
+- 5) The test signal at point B should be frequently interrupted (or on/off modulated at approximately 0.5 Hz). After 2 minutes, recheck the ALC device gain by measuring the level of the signal at point C. The level of the signal at the input to the ALC device may be assumed to be 6 dB below the level of the test signal at point B.  
+The gain of the ALC device at this stage should be within 1 dB of the value noted in step 3.
+- 6) Remove the test signal from point B.
+- 7) Apply a test signal (on/off modulated if necessary; see clause 6) to point A at a level 8 dB below the target level of the ALC device. This will ensure that the ALC device progresses to unity gain (or above if the ALC device is permitted to introduce gain).
+- 8) Repeat step 3.
+- 9) Remove the test signal from point A. Apply a test signal to point B at a level of  $-2 \text{ dBm}_0$ .
+- 10) Repeat step 5. The measured gain should be within 1 dB of that noted in step 8.
+- 11) If the ALC device gain change noted in steps 5 or 10 is more than 1 dB, the ALC device should be considered to have failed the test.
+
+### **Test B (for connections with echo control)**
+
+The following test procedure should be used when it is intended that an ALC device will be used in a network with echo control (echo suppressors or echo cancellers), including the case where an ALC device is integrated with an echo canceller. The test procedure is valid whether the ALC device is installed in the send path of a connection [test circuit illustrated in Figure 3 a)] or the receive path [test circuit shown in Figure 3 b)]. However, in either case, the ALC device under test must be the only ALC device active. If it is unavoidable that other ALC devices are present in the test set-up [e.g., ALC devices integrated into the echo control device of Figures 3 a) or 3 b)], other than the ALC device under test], then these ALC devices must be disabled for the purposes of the test.
+
+![Figure 3 a) Circuit configuration for 'Test B' - ALC installed in the send path of a connection with echo control. The diagram shows a signal flow from point B through an 'Echo Control' block. A portion of the signal is delayed by 'End Path Delay' and then enters an 'echo path' represented by a curved arrow. The signal then passes through an 'ERL 6 dB' block and a summing junction (+). The output of the summing junction is labeled A. A feedback loop from the summing junction goes through an 'ALC' block and back to the 'Echo Control' block, with the output of the ALC block labeled C.](fa859e4e468bfb2710a94527f2c504af_img.jpg)
+
+Figure 3 a) Circuit configuration for 'Test B' - ALC installed in the send path of a connection with echo control. The diagram shows a signal flow from point B through an 'Echo Control' block. A portion of the signal is delayed by 'End Path Delay' and then enters an 'echo path' represented by a curved arrow. The signal then passes through an 'ERL 6 dB' block and a summing junction (+). The output of the summing junction is labeled A. A feedback loop from the summing junction goes through an 'ALC' block and back to the 'Echo Control' block, with the output of the ALC block labeled C.
+
+a) ALC installed in the send path of a connection with echo control
+
+![Figure 3 b) Circuit configuration for 'Test B' - ALC installed in the receive path of a connection with echo control. The diagram shows a signal flow from point B through an 'Echo Control' block, then a 'Delay' block, then another 'Echo Control' block. A portion of the signal is delayed by 'End Path Delay' and then enters an 'echo path' represented by a curved arrow. The signal then passes through an 'ERL 6 dB' block and a summing junction (+). The output of the summing junction is labeled A. A feedback loop from the summing junction goes through a 'Delay' block, an 'ALC' block, and back to the first 'Echo Control' block, with the output of the ALC block labeled C. A small text 'T1530250-98' is visible near the bottom right of the diagram.](0f985b39edc1d52ba3600c438bc8f0a5_img.jpg)
+
+Figure 3 b) Circuit configuration for 'Test B' - ALC installed in the receive path of a connection with echo control. The diagram shows a signal flow from point B through an 'Echo Control' block, then a 'Delay' block, then another 'Echo Control' block. A portion of the signal is delayed by 'End Path Delay' and then enters an 'echo path' represented by a curved arrow. The signal then passes through an 'ERL 6 dB' block and a summing junction (+). The output of the summing junction is labeled A. A feedback loop from the summing junction goes through a 'Delay' block, an 'ALC' block, and back to the first 'Echo Control' block, with the output of the ALC block labeled C. A small text 'T1530250-98' is visible near the bottom right of the diagram.
+
+b) ALC installed in the receive path of a connection with echo control
+
+NOTE – The ALC device may be integrated with the echo control device.
+
+**Figure 3 – Circuit configurations for "Test B" – ALC echo robustness for connections with echo control**
+
+When dealing with echo signals, it will normally be impossible to measure the gain of an ALC device integrated into the send path of an echo canceller, since access to the ALC device input is unlikely to be available. It is, in any case, difficult to measure the gain of an ALC device when the level of the echo signal at its input is drastically reduced by an echo control device. The following procedure attempts to circumvent these problems by confining observations to those of ALC device output level when passing a signal not attenuated by the echo control device.
+
+NOTE – If the echo control device is an echo canceller, it should first be fully converged by applying a noise signal at point B (see clause 7).
+
+- 1) Connect the ALC device into an emulation of part of a connection, including the echo path contributing to the signal arriving at the input port of the ALC device. A basic test-circuit configuration is shown in Figure 3 a) for an ALC device installed in the send path of a connection, and in Figure 3 b) for ALC installed in the receive path. The test points referred to below are marked A, B and C in these figures. The echo return loss (ERL) value of 6 dB is chosen to represent worst-case echo conditions.
+- 2) Apply a test signal (on/off modulated if necessary; see clause 6) to point A of the test circuit, at a level of  $-2$  dBm0. This level is sufficiently high to ensure that the ALC device gain is driven to (or near) its minimum value.
+- 3) Establish a real-time analogue display (e.g., using an oscilloscope) of the signal at point C of the test circuit, and note the magnitude of the displayed signal. (Other means of recording the level of the signal may be used, but the chosen method must also be applicable to step 5.)
+
+- 4) Remove the test signal from point A, and apply it to point B at the same level. The test signal at point B should be frequently interrupted (or on/off modulated at approximately 0.5 Hz).
+- 5) After 1 minute, remove the test signal from point B, and re-apply it to point A. At the instant the signal arrives at point C, make an immediate note of the magnitude of the displayed signal at point C, or make a level measurement within 100 ms. (The method of level measurement should be the same as that used in step 3.) The purpose is to check whether the ALC device gain changed at all during step 4.
+- 6) If the magnitude noted in step 5 exceeds that noted in step 3 by more than 12%, (or the level measurement is greater by more than 1 dB), the ALC device should be considered to have failed the test.
+
+## 7.3 Noise tolerance
+
+Automatic level control systems are designed to adjust speech signals towards an optimum level. During speech pauses there may be an undesirable tendency for the gain to adjust in response to the level of background noise. Therefore, tests should be made to show that the level control is robust to the worst signal-to-background noise ratio anticipated on the network.
+
+The background noise will consist of a combination of environmental noise picked up by the handset microphone, and electrical circuit noise, the latter being particularly relevant when analogue circuits form part of the connection. These two noise sources are likely to exhibit very different characteristics. Electrical circuit noise tends to be broadband in nature, and reasonably constant in level when averaged over periods greater than a few hundred milliseconds. The nature of environmental noise obviously depends on the environment, but it may often be fluctuating in level and have spectral characteristics that are similar to speech. Indeed, the noise may often contain speech picked up from other conversations taking place near the telephone. In the mobile environment, vehicle noise is a major contributor, and noise levels can be very high.
+
+An ALC device designed for use in telecommunication networks must incorporate measures to discriminate between the wanted signal and noise. From the previous paragraph, it is clear that environmental noise is likely to represent more of a problem to an ALC device than electrical circuit noise. In recognition of this fact, three separate tests are presented below. "Test A" is primarily designed to check the robustness of the ALC device to electrical circuit noise. Tests "B" and "C" provide some measure of assurance with respect to different types of background noise by testing against environmental noise as defined in clause 6.3 above in "Test B" and testing against some real environmental noise captures in "Test C". These are minimum performance requirements, and it is hoped that manufacturers can devise techniques to give a higher standard of performance.
+
+### Test A (robustness to circuit noise)
+
+- 1) Connect the ALC device (or the equipment containing the ALC device) into an appropriate test circuit, such that test signals can be applied to the input of the device, and the level of the input and output signals can be monitored. [The circuit used for the echo test (Figure 2, Figures 3 a) or 3 b) as appropriate) may be used if desired, but no signal should be connected to point B, and the ERL should be set to infinity.]
+- 2) Apply a test signal (on/off modulated if necessary; see clause 6) to the input of the ALC device (or equipment containing the device), at a level of  $-5$  dBm0. This level is sufficiently high to ensure that the ALC device gain is driven to (or near) its minimum value.
+- 3) Measure the level of the signal at the output of the ALC device, and from this derive the value of the ALC device gain.
+- 4) Replace the test signal at the input of the ALC device with a continuous white Gaussian noise signal (band limited 0-3.4 kHz) at a level of  $-40$  dBm0.
+
+- 5) After at least 10 seconds, recheck the ALC device gain by measuring the level of the noise signal at the device output.
+- 6) Allowing for measurement inaccuracies, the gain of the ALC device at step 5 should be within 1 dB of the value noted in step 3. If the gain has increased significantly relative to the value noted in step 3, the ALC device should be considered to have failed the test.
+
+### **Test B (robustness to environmental noise)**
+
+This test is similar to Test A, but the nature of the noise signal has been changed. The adopted noise test signal reflects the fact that environmental noise may be difficult for an ALC device to reject.
+
+The noise test signal used in the test should consist of a white Gaussian noise signal, band limited to the frequency range 0-800 Hz, and continuously on/off modulated at the rate 1 second on/1 second off. References to the level of the noise test signal relate to the level of the "on" portion of the signal, equivalent to the mean power of the unmodulated signal. The following steps 1 through 5 should be repeated for 4 different noise levels (when unmodulated) of  $-28\text{ dBm0}$ ,  $-23\text{ dBm0}$ ,  $-18\text{ dBm0}$  and  $-13\text{ dBm0}$ .
+
+- 1) Connect the ALC device (or the equipment containing the ALC device) into an appropriate test circuit, such that test signals can be applied to the input of the device, and the level of the input and output signals can be monitored. [The circuit used for the echo test (Figure 2, Figures 3 a) or 3 b) as appropriate) may be used if desired, but no signal should be connected to point B, and the ERL should be set to infinity.]
+- 2) Apply a test signal (on/off modulated if necessary; see clause 6) to the input of the ALC device (or equipment containing the device), at a level of  $-5\text{ dBm0}$ . This level is sufficiently high to ensure that the ALC device gain is driven to (or near) its minimum value.
+- 3) Measure the level of the signal at the output of the ALC device, and from this derive the value of the ALC device gain.
+- 4) Replace the test signal at the input of the ALC device with a noise test signal, as defined above.
+- 5) After at least 20 seconds, recheck the ALC device gain by measuring the level (when unmodulated) of the noise test signal at the device output.
+- 6) Allowing for measurement inaccuracies, the gain of the ALC device at step 5 should be within 1 dB of the value noted in step 3. If the gain has increased significantly relative to the value noted in step 3, the ALC device should be considered to have failed the test.
+
+### **Test C (robustness to white Gaussian noise and real environmental noise – car, street and babble)**
+
+The noise test signals in this test consist of car, street and babble noise files in addition to white Gaussian noise of 24 s duration. Each sample should be about 8 seconds long. The noise is not modulated like it is in Test 7.3B but is repeated three times to get a total duration of 24 seconds. Examples of industry-accepted noise files that are suitable for this test are given in [b-AURORA]. The following steps 1 through 5 should be repeated for every one of twelve combinations of noise type and level. The noise types as described above are white, car, street and babble. The noise levels as in test 7.2B would be  $-28\text{ dBm0}$ ,  $-23\text{ dBm0}$ ,  $-18\text{ dBm0}$  and  $-13\text{ dBm0}$ .
+
+- 1) Connect the ALC device (or the equipment containing the ALC device) into an appropriate test circuit, such that test signals can be applied to the input of the device, and the level of the input and output signals can be monitored.
+- 2) Apply a test signal (on/off modulated if necessary; see clause 6) to A (Figure 2), the input of the ALC device (or equipment containing the device), at a level of  $-5\text{ dBm0}$ . This level
+
+is sufficiently high to ensure that the ALC device gain is driven to (or near) its minimum value.
+
+- 3) Measure the level of the signal at the output of the ALC device, and from this derive the value of the ALC device gain.
+- 4) Replace the test signal at the input of the ALC device with a combination of noise test signal and level, as defined above.
+- 5) After 24 seconds, repeat the noise file one final time to check the ALC device gain by measuring the level of the noise test signal for the entire 8 seconds at the device output.
+- 6) Allowing for measurement inaccuracies, the gain of the ALC device at step 5 should be within 1 dB of the value noted in step 3. If the gain has increased significantly relative to the value noted in step 3, the ALC device should be considered to have failed the test.
+
+## 7.4 Signalling tones
+
+An ALC system must not interfere with the correct operation of signalling tones used in the network. In the case of tones used to set up a connection, the level control could, for example, be disabled (held at unity gain) until the link is established. For DTMF signals, it will be necessary to test that the level control does not affect the reliability of their detection.
+
+### 7.4.1 DTMF tests
+
+A typical ALC device is unlikely to differentiate between speech signals and DTMF signals; therefore, it is possible that gain adjustments will occur during the transmission of DTMF signalling. The accuracy of DTMF detection may depend not only on the ALC device, but also on the particular DTMF detector.
+
+#### Method 1
+
+It is assumed that an ALC device operates on DTMF tones, where  $-23 \text{ dBm0} \leq \text{target level} \leq -5 \text{ dBm0}$ . With this stipulation, DTMF detectors, in general, may be tolerant of the gain changes introduced by an ALC device, provided that the rate of change of gain during transmission of a tone is sufficiently slow. A suitable test for maximum rate of change of gain is outlined below, and the test circuit is shown in Figure 4.
+
+NOTE 1 – The test describes uses hardware detection and measuring equipment applied to the analogue signal. However, an equivalent software test applied to the digital signal is equally valid.
+
+![Circuit configuration for measuring rate of change of ALC device gain. A 1004 Hz, -1 dBm0 signal source is connected to a switch with three positions (1, 2, 3). Position 2 is connected to an attenuator labeled 'L'. The output of the attenuator is connected to the input of an ALC device. The output of the ALC device is connected to a Level detector. The Level detector has a diode, a capacitor, and a comparator with a reference voltage 'V.Threshold'. The output of the comparator is connected to an Elapsed-time display. The Elapsed-time display has a Start/Stop input. The Start/Stop input is connected to the output of the Level detector. The diagram is labeled T1530260-98.](04f51626e2e10a16e3eb2c4b33cb2742_img.jpg)
+
+```
+
+graph LR
+    S[1004 Hz  
+-1 dBm0] --> SW{Switch}
+    SW -- 1 --> ALC[ALC]
+    SW -- 2 --> L[Attenuator L] --> ALC
+    SW -- 3 --> ALC
+    ALC --> LD[Level detector]
+    subgraph LD_Box [Level detector]
+        D[Diode] --> C[Capacitor]
+        C --> Comp[Comparator]
+        VT[V.Threshold] --> Comp
+    end
+    Comp --> ETD[Elapsed-time display]
+    ETD -- Start/Stop --> Comp
+
+```
+
+Circuit configuration for measuring rate of change of ALC device gain. A 1004 Hz, -1 dBm0 signal source is connected to a switch with three positions (1, 2, 3). Position 2 is connected to an attenuator labeled 'L'. The output of the attenuator is connected to the input of an ALC device. The output of the ALC device is connected to a Level detector. The Level detector has a diode, a capacitor, and a comparator with a reference voltage 'V.Threshold'. The output of the comparator is connected to an Elapsed-time display. The Elapsed-time display has a Start/Stop input. The Start/Stop input is connected to the output of the Level detector. The diagram is labeled T1530260-98.
+
+NOTE – i) Attenuator  $L = -[1 + \text{target level (dBm0)}] \text{ dB}$ .
+
+ii)  $V.\text{Threshold}$  set so that elapsed-time counter stops when the output level from the ALC device falls to  $-4 \text{ dBm0}$ .
+
+**Figure 4 – Circuit configuration for measuring rate of change of ALC device gain**
+
+NOTE 2 – Certain ALC devices operate by making instantaneous large step changes in gain, and other devices can introduce step decreases in gain during overload conditions. The following test is not valid in these situations. However, if step gain changes are only permitted during pauses in the transmitted signal, or at the very start of a signal burst, it may be assumed that this type of gain behaviour will not affect the accuracy of DTMF detection.
+
+- 1) Connect external threshold-level detection logic to the output of the ALC device. This logic should be configured to control the start and stop of an elapsed-time counter. For an increasing signal level at the output of the ALC device, the timer should start when the level is somewhere between  $-4$  dBm0 and  $-2$  dBm0. For a decreasing signal level, the timer should stop when the level reaches precisely  $-4$  dBm0.
+- 2) Apply a 1004 Hz test tone to the input of the ALC device at the specified or pre-set target level. Note that with some ALC devices, the target level may be different for different types of signals. Allow time for the ALC device gain to settle to unity. (For certain ALC devices, it may be necessary to disconnect and reconnect the test tone a few times to ensure that the gain settles to unity).
+- 3) Confirm that the ALC device is at unity gain by monitoring input and output levels to the device.
+- 4) Instantaneously increase the level of the input signal to the ALC device to  $-1$  dBm0, which should automatically trigger the start of the elapsed-time counter.
+- 5) The elapsed-time counter should stop automatically when the output signal level from the ALC device has fallen from  $-1$  dBm0 to  $-4$  dBm0, i.e., the ALC device gain has fallen by 3 dB. From this, the rate of change of gain may be derived, and expressed in dB/s. The derived value will approximate to the maximum rate of change of gain for the ALC device.
+- 6) The ALC device should be considered to have passed the test if the derived rate of change of gain is less than 10 dB/s.
+
+#### Method 2
+
+The following test procedure should be followed if test method 1 is inappropriate for a particular ALC device, or if the device fails test method 1, or the results are inconclusive.
+
+In any test to check DTMF detection accuracy in a connection with an ALC device, the choice of DTMF detector may influence the percentage of detection failures. To circumvent this problem, the following test is based on a comparison of DTMF detection performance with and without the ALC device in-circuit. It is therefore unnecessary to specify a standard DTMF detector for the test.
+
+The test requires a means of inputting a sequence of DTMF characters to the test circuit (e.g., sequence stored on digital audio tape, or PC file). A suitable DTMF detector (which may be PC-based for convenience) is also required, together with a means of recording the percentage of character detection failures in the replayed DTMF test sequence. A noise source is needed for the second phase of the tests, and the basic test configuration is shown in Figure 5.
+
+The DTMF test sequence should consist of 256 different DTMF signals, arranged as 16 sets of the 16 DTMF characters (0..9,#,\*,A,B,C,D). Each set has the frequency offset specified in Table 1. The replayed levels of the discrete frequencies making up the tone pairs should be as specified in Table 1. Each DTMF character should have a duration of 50 ms, with an interval between characters of 100 ms. The interval between each set should be 1 second, and the 16 sets of DTMF characters should be replayed as a continuous sequence of 256 characters.
+
+**Table 1 – DTMF test sequences**
+
+| Set No. | Freq. offset (%) | Freq. offset (%) | Level (dBm0) | Level (dBm0) |
+|---------|------------------|------------------|--------------|--------------|
+|         | (low freq.)      | (high freq.)     | (low freq.)  | (high freq.) |
+| 1       | 0                | 0                | 0            | 0            |
+| 2       | 0                | 0                | -18          | -18          |
+| 3       | 1.5              | 1.5              | -10          | -10          |
+| 4       | -1.5             | -1.5             | -10          | -10          |
+| 5       | 0                | 0                | -12          | -18          |
+| 6       | 0                | 0                | -14          | -10          |
+| 7       | 1.5              | 1.5              | -14          | -20          |
+| 8       | -1.5             | 1.5              | -14          | -20          |
+| 9       | 1.5              | -1.5             | -6           | -12          |
+| 10      | -1.5             | -1.5             | -6           | -12          |
+| 11      | 0                | 0                | -12          | -18          |
+| 12      | 0                | 0                | -14          | -10          |
+| 13      | 1.5              | 1.5              | -10          | -6           |
+| 14      | -1.5             | 1.5              | -10          | -6           |
+| 15      | 1.5              | -1.5             | -18          | -14          |
+| 16      | -1.5             | -1.5             | -18          | -14          |
+
+Annex A of [ITU-T Q.24] indicates that some Administrations require DTMF receivers to tolerate power levels per frequency up to 0 dBm.
+
+![Figure 5: Circuit configuration to check the effect of ALC device on DTMF detection performance. The diagram shows a 'Replay medium for DTMF test sequence (e.g. digital audio tape)' connected to a summing junction (+). An 'Emulated circuit noise (-10 dBm0)' source, controlled by a '0-30 dB & OFF' switch, is also connected to this junction. The output of the summing junction is connected to an 'ALC device', which is controlled by an 'Enable/disable ALC device' input. The output of the ALC device is connected to a 'DTMF receiver', which in turn is connected to a 'Logging of DTMF character detection failures' block.](79e1709a7317ead45379cbb8ff3ba802_img.jpg)
+
+```
+
+graph LR
+    A[Replay medium for DTMF test sequence  
+(e.g. digital audio tape)] --> Sum((+))
+    B[Emulated circuit noise  
+(-10 dBm0)] -->|0-30 dB & OFF| Sum
+    Sum --> ALC[ALC device]
+    C[Enable/disable ALC device] --> ALC
+    ALC --> DTMF[DTMF receiver]
+    DTMF --> Logging[Logging of DTMF character detection failures]
+  
+```
+
+Figure 5: Circuit configuration to check the effect of ALC device on DTMF detection performance. The diagram shows a 'Replay medium for DTMF test sequence (e.g. digital audio tape)' connected to a summing junction (+). An 'Emulated circuit noise (-10 dBm0)' source, controlled by a '0-30 dB & OFF' switch, is also connected to this junction. The output of the summing junction is connected to an 'ALC device', which is controlled by an 'Enable/disable ALC device' input. The output of the ALC device is connected to a 'DTMF receiver', which in turn is connected to a 'Logging of DTMF character detection failures' block.
+
+T1530270-98
+
+**Figure 5 – Circuit configuration to check the effect of ALC device on DTMF detection performance**
+
+- 1) With the ALC device disabled, replay the DTMF test sequence over the test circuit. Record the percentage of detection failures and detection errors.
+- 2) Repeat step 1 a sufficient number of times to satisfactorily establish the standard of DTMF detection performance.
+- 3) Repeat steps 1 and 2, but with the ALC device enabled. If DTMF detection performance is noticeably worse with the ALC device enabled, it must be assumed that the ALC device degrades the transmission of DTMF signals.
+- 4) If the preceding steps do not show a noticeable difference in DTMF detection accuracy between the two conditions, proceed as follows.
+
+- 5) Arrange for emulated circuit noise to be injected into the test circuit at the input to the ALC device.
+- 6) Starting with a suitable level of circuit noise (e.g.,  $-40\text{ dBm}0$ ), repeat step 1 a number of times, increasing the level of circuit noise at the end of each run until the percentage of DTMF detection failures reaches approximately 5%.
+- 7) Maintain the level of injected circuit noise at the value reached in step 6. Repeat steps 1 to 3.
+- 8) If the preceding steps indicate that the ALC device does not cause a problem for DTMF transmission, as final confirmation of this conclusion, repeat all of the above with the DTMF test sequence attenuated by 6 dB at the input to the ALC device.
+
+## 7.5 Voiceband data and facsimile transmission
+
+An ALC system designed to enhance speech transmission must not degrade other telecommunications services such as voiceband data and fax. An ALC device should therefore be designed to automatically disable upon detection of the 2100 Hz tone (with or without associated phase reversals or amplitude modulation) that precedes ITU-T V-series modem communications. A suitable disabler is described in 7.5.1. For ALC devices operating in the forward direction of a voiceband data or fax transmission, recognition of 2100 Hz tone implies that the device should be connected to both the go and return paths. The tone disabler of an ALC device should therefore be designed to operate on tones that are present in either direction of transmission.
+
+For the purpose of disabling ALC devices, consideration may also be given to more sophisticated methods of detecting voiceband data or facsimile transmissions. However, if implemented, such methods should be considered as additional to the basic requirements of the tone disabler specified in 7.5.1.
+
+A disabled device should provide bit-sequence integrity for the full duration of the voiceband data or fax call. In the case of the latter, it is important that the ALC device should remain disabled throughout the transmission of a multi-page document, i.e., there should be no tendency for the ALC device to re-enable during page breaks or other pauses in the fax transmission.
+
+In recognition of the fact that a small proportion of voiceband data and fax calls may not be preceded by 2100 Hz answer tone, it is additionally recommended that an enabled ALC device should not degrade these transmissions under normal network conditions; extremes of signal level and circuit noise may be excluded from the verification tests, provided the requirements for 2100 Hz disabling have been fully met.
+
+### 7.5.1 Disabler characteristics
+
+This subclause deals with the specification of an ALC device disabler that is activated on reception of 2100 Hz answer tone. The objectives for a disabler are that the ALC device should be disabled throughout the full duration of fax and data transmissions.
+
+The requirements for an ALC device tone disabler are the same, in many respects, as the requirements for echo suppressor and echo canceller tone disableers. The principal differences between echo suppressor and echo canceller tone disableers are briefly reviewed in the next paragraph.
+
+The required characteristics for an echo suppressor tone disabler are presented in [ITU-T G.164]. The required characteristics for an echo canceller tone disabler are presented in [ITU-T G.165] and also in [ITU-T G.168]. To disable an echo canceller, the ITU-T G.165 or ITU-T G.168 tone disabler must detect a 2100 Hz tone with periodic phase reversals (as specified in [ITU-T V.25]). The ITU-T G.164 tone disabler will implement disabling on detection of a 2100 Hz tone, with or without phase reversals. In other respects, the required characteristics of the two types of echo control device tone disabler are very similar. The ITU-T G.165 or ITU-T G.168 disabler has an
+
+additional requirement that it should not operate falsely on data signals; (this requirement is inappropriate for an ALC device tone disabler). Also, compared with the ITU-T G.164 disabler, the need to detect phase reversals of the 2100 Hz tone has led to an increase in the maximum time allowed for the ITU-T G.165 or ITU-T G.168 disabler to operate in response to the disabling tone.
+
+Once activated, the conditions for release from the disable state are the same for both the ITU-T G.164 and ITU-T G.165 or ITU-T G.168 specifications. Release is based on the signal level in both directions of transmission falling below a threshold level for more than a specified time period (the 'release time'). The specified release time is  $250 \pm 150$  ms; the lower limit is chosen to prevent unwanted release for short signal drop-outs, and the upper limit is to minimize the impairment if the disabler is accidentally activated by speech.
+
+An ALC device tone disabler is required to disable the device for all fax and data calls. The tone disabler must therefore respond to 2100 Hz tone, with or without phase reversals. The ITU-T G.164 tone disabler is suitable in this respect, whereas the ITU-T G.165 or ITU-T G.168 disabler is not. An ALC device tone disabler should also respond to 2100 Hz tone with amplitude modulation (as defined in [ITU-T V.8]).
+
+An important requirement for an ALC device disabler is that it should keep the device disabled throughout the full duration of fax and data transmissions. The release time specified for the echo control disable is insufficient to achieve this, since there would be a strong tendency for the ALC device to become re-enabled during pauses in a fax transmission (e.g., page breaks). To satisfy the requirement to maintain the disabled state throughout a fax transmission, the minimum release time for an ALC device tone disabler is recommended to be 3450 ms<sup>2</sup>. However, a long release time is undesirable in the event that the disabler is accidentally activated by speech; therefore, the release time should not be permitted to greatly exceed the minimum value. The recommended maximum release time is 3500 ms.
+
+Concerning the possibility of an ALC device disabler being accidentally activated by speech, it is more important to ensure that this is a rare event than it is to re-enable the device quickly if such an unwanted event occurs. This is because the initial unwanted gain reset will be the primary cause of subjective impairment due to the probable step gain change that occurs, whereas the persistence of the disabled state is merely the continuance of the unity gain state. When the ALC device eventually re-enables, a gradual progression will ensue back to a gain value more suited to the actual speech level. With this in mind, designers of tone disableers for ALC devices may wish to maximise the 'operate time' for the disabler, since a longer operate time gives improved immunity to false operation by speech. However, as the disabler is required to activate for all fax and data calls, the operate time must be less than the minimum anticipated duration of answer tone. The duration of answer tone in various scenarios is specified in [ITU-T V.25], and examination of ITU-T V.25 indicates that an appropriate maximum value for the operate time of an ALC device tone disabler would be 400 ms, as adopted for the ITU-T G.164 tone disabler. It is therefore recommended that ALC device tone disableers adopt the operate time specification of the ITU-T G.164 tone disabler, i.e.,  $300 \pm 100$  ms.
+
+In summary, an ALC device tone disabler should have the characteristics of either a ITU-T G.164 or a ITU-T G.165 or ITU-T G.168 tone disabler, modified where necessary to ensure the following:
+
+- Disabling should occur in response to 2100 Hz tone, with or without phase reversals (as specified in [ITU-T V.25]), and with or without amplitude modulation (as defined in [ITU-T V.8]).
+- Operate time = 200 ms minimum
+
+---
+
+<sup>2</sup> Recommendation T.30 shows that silence periods of  $3\text{ s} \pm 15\%$  are permitted following establishment of a fax call, and the same interval is permitted following a 'repeat' request. In practice, there are various situations that may result in a long pause.
+
+- |   |                |                 |
+|---|----------------|-----------------|
+|   | 400 ms         | maximum         |
+| • | Release time = | 3450 ms minimum |
+|   | 3500 ms        | maximum         |
+
+NOTE – The release time specified above is necessary, only if the tone disabler re-enables the ALC device solely on detecting the absence of signal energy. If the tone disabler re-enables based on other criteria, then the release time specified above does not apply. Tests for proper operation are for further study.
+
+### 7.5.2 Tests to confirm satisfactory voiceband data and fax performance when an ALC device is not disabled by 2100 Hz
+
+The following tests are considered necessary, since a small percentage of fax or voiceband data calls may not be preceded by 2100 Hz answer tone, and therefore, the ALC device may remain enabled during these calls. The tests are based on a direct comparison of performance with and without the ALC device enabled.
+
+Separate tests should be conducted for voiceband data and facsimile transmissions, although the basic test procedure is the same in both cases. To facilitate the tests, it is recommended that specialized, proprietary voiceband data or fax test equipment is used, but other arrangements capable of making the required observations are acceptable.
+
+For voiceband data tests, the test equipment should be configured to operate in automatic answer mode, conforming to the requirements of [ITU-T V.25].
+
+For facsimile tests, the test equipment should be configured to follow the procedures defined in [ITU-T T.30], and with the following ITU-T T.30 options selected:
+
+- automatic operation at both the calling and the called stations;
+- calling station transmits to called station, (operating method 4-T in [ITU-T T.30]);
+- binary coded signalling at 300 bit/s to be used (rather than tonal signalling);
+- the standard time-outs for binary coded signalling should apply;
+- the optional error correction mode defined in Annex A of [ITU-T T.4] (and the associated procedures described in Annex A of [ITU-T T.30]) should not be used.
+
+For designers of fully-automated ITU-T G.169 test equipment, it is recognized that adherence to all aspects of ITU-T T.30 call control may be unnecessarily restrictive. For such designs, the requirement to follow ITU-T T.30 procedures may be relaxed, but the principle of comparing fax transmission performance with and without the ALC device must remain the basis of the test.
+
+The ALC device must be tested under conditions that reflect the type of connection in which it is to be used. The test circuit should emulate the principle features of a connection, including delays appropriate to the type of connection (e.g., international, via satellite). The echo return loss (ERL) should be 6 dB or better, for both directions of transmission. The ALC device should be installed at the intended point within the emulated connection, and should be located in the calling station to called station direction. For fax, this should represent the direction of facsimile transmission adopted for the tests. For voiceband data, this represents the direction in which error rate performance should be monitored.
+
+In the following test procedures, references to transmit level relate to the level in the calling station to called station direction. The transmit level should be set up by an appropriate combination of the level from the test equipment, and the losses in the emulated connection; both these controlling factors may be varied within realistic operational limits to achieve the specified transmit level. The level in the opposite direction of transmission is not specified, but should be that which results naturally from the emulated connection (configured to achieve the specified transmit level), and an operationally realistic level from the test equipment representing the called station. An additional constraint on the emulation is that the receive level at both the calling and called stations should be high enough to allow reliable operation of the fax or voiceband data test equipment. (Typically, a minimum receive level of  $-40$  dBm would be adequate.)
+
+#### Test procedure
+
+As the ALC device will disable in response to 2100 Hz answer tone, for comparison purposes, a method must be found to prevent this happening for some of the fax and voiceband data transmissions. The ALC device may include a facility to force it to ignore 2100 Hz answer tone; if not, it will be necessary to eliminate 2100 Hz answer tone from the test transmissions, and set the ALC device to the required enabled or disabled state prior to each transmission. If there are echo cancellers in the test circuit, it will also be necessary to ensure that these are in the desired state for the test transmissions.
+
+NOTE – If it is necessary to eliminate answer tone, this represents a modification to the ITU-T V.25 or ITU-T T.30 requirements for an automatic answer configuration.
+
+- 1) Connect proprietary voiceband data, or fax test equipment (as appropriate) to the test circuit. Since high-speed communications are more sensitive to impairments than low-speed communications, the test equipment should be configured to attempt to communicate at the highest data rate in common use in the network.
+- 2) Make appropriate arrangements to ensure that the ALC device will be disabled (set to fixed unity gain) during a fax or data transmission. (If the ALC device does not have a disable facility, it may be necessary to temporarily replace it with a direct connection.)
+- 3) At a chosen transmit level, make a fax or data transmission over the connection using a reference data file. In the case of voiceband data transmissions, it should be arranged that the data transfer takes at least 20 seconds at the selected communication rate. For fax transmission, the transferred data should comprise at least a 3-page fax, since page breaks may influence the operation of the ALC device.
+- 4) Observe whether any fall-back in transmitted data rate occurred relative to the selected maximum rate, and whether any other disruption occurred to the normal sequence of events to establish communications.
+- 5) Note the result of an appropriate measure or indication of the received data errors.
+- 6) Make appropriate arrangements to ensure that the ALC device will not be disabled by 2100 Hz answer tone at the start of a fax or voiceband data transmission.
+- 7) Repeat steps 3, 4 and 5, noting any significant differences in performance or behaviour relative to that obtained previously.
+- 8) Repeat steps 2 to 7 a number of times, for different transmit levels in step 3. The transmit level should be varied over the range  $-8$  dBm $_0$  to  $-22$  dBm $_0$ <sup>3</sup>.
+
+---
+
+<sup>3</sup> Measurements show that about 8% of UK international receive fax levels lie outside this range. Assuming that up to 5% of fax calls are not preceded by a suitable ALC device disabling tone, this test will ensure that at least 99.6% of fax calls are not degraded by the ALC device.
+
+- 9) If, at any of the transmit levels tested, the performance with the ALC device enabled is appreciably worse than with the device disabled, the ALC device should be considered to have failed the test. In particular, any fall-back in transmitted data rate caused by the ALC device is unacceptable.
+
+## 7.6 Test to verify the ability of an ALC to estimate the signal level correctly
+
+ALCs are used to normalize long term speech levels and it is important to verify that the device is correctly able to estimate speech levels so that it is not deviating too much from the desired target level. For example, if an ALC uses a noise floor method to discriminate between speech and noise, then it is quite possible for the ALC to miss too many low energy speech frames causing it to over-estimate the signal level and erroneously attenuate the signal. In this proposed new test, the ability of the ALC to correctly estimate the level of speech, even in the presence of noise, will be tested. The test should be repeated for a range of different signal levels and signal-to-noise ratios (SNRs).
+
+In this test, we are testing the ability of ALC to correctly estimate the level of speech even in the presence of noise. This also tests the ability of ALC to bring the signal to the target level correctly.
+
+The test signals should consist of ITU recommended clean speech files each consisting of two utterances. The same clean utterances will be used to measure the gain applied by ALC. The test signals would be mixed with additive white Gaussian noise at different levels to create signals of required SNR. The clean speech signals would be first normalized using [ITU-T P.56] to a level of  $-20$  dBm0. This normalized signal is used to generate test signals of required levels by appropriately scaling the normalized signal of  $-20$  dBm0. The test is repeated for levels of  $-24$  dBm0,  $-18$  dBm0 and  $-12$  dBm0 and also for SNRs of  $\infty$  dB, 20 dB, 15 dB and 10 dB giving rise to a total of 12 test cases.
+
+- 1) Connect the ALC device (or the equipment containing the ALC device) into an appropriate test circuit, such that the test signals can be applied to the input of the device, and the level of the input and output signals can be monitored.
+- 2) For every signal level chosen, set the target level on ALC to be at least 4 dB more than the input signal level.
+- 3) Apply the test signal of appropriate SNR consisting of the sequence of 3 ITU files (a total of 6 utterances) to A (Figure 2), the input of the ALC device (or equipment containing the device). The test signal would last a period of 24 seconds. This would give the device sufficient time to estimate the signal level and apply the appropriate gain.
+- 4) Replace the test signal at the input of the ALC device with the clean speech version of the test signal of 8-second duration of the same level.
+- 5) Measure the level of the output of ALC using [ITU-T P.56] for the signal applied in step 4.
+- 6) Allowing for measurement inaccuracies, the level estimated in step 5 should be within 1 dB of the target level. If the difference is beyond these limits, then the ALC device should be considered to have failed the test.
+
+## **7.7 Test to verify the ability of an ALC to operate on short speech utterances (under study)**
+
+It is important to consider how an ALC takes into account short utterances of speech. If an ALC implements a long hangover to address the noise robustness tests, then the ALC will only use long bursts of speech to estimate speech levels and this can either bias the speech levels up or down or can delay the time before which the ALC becomes effective. Therefore, good designs ensure that short bursts of speech are taken into account for estimating long-term levels. However, this needs to be balanced against the possibility of an ALC incorrectly adapting to short words often muttered during a conversation. A definition of a short utterance is therefore required as a prerequisite to this test.
+
+# Annex A
+
+# Guidance for measuring signal levels in networks
+
+(This annex forms an integral part of this Recommendation.)
+
+Level measurements are necessary to check whether signal levels in a network are within an acceptable range. A large number of calls must be measured in order to obtain a statistically valid distribution of call levels. The distribution will show whether call levels are generally too high, too low, or have an unacceptably widespread.
+
+Speech signal levels are best measured with an instrument conforming to [ITU-T P.56], which specifies a method of measuring the rms level of a signal during periods when that signal is active. The restriction to active signal periods is particularly important for speech signals because there are silence intervals in the speech waveform that act to reduce the long term level. The ITU-T P.56 algorithm defines how to determine the level at which the speech signal is considered to be active (since this will vary with different talker levels and background noise) and calculates the rms value over the active periods only. Although an instrument conforming to [ITU-T P.56] is primarily aimed at the measurement of speech signal levels, it may also be used to measure the level of facsimile and voiceband data signals, signalling tones, etc.
+
+Some Administrations use automatic equipment (see [ITU-T P.561]) to make routine level measurements on their networks. Typically, such level measurements will either conform to the ITU-T P.56 method, or adopt similar active signal measurement principles. The use of proprietary, automatic equipment greatly reduces the labour needed to make a large number of measurements. However, in many situations – trouble-shooting, in particular – manual level measurements are still appropriate, due to their flexibility, ease of deployment and low equipment costs. The following paragraphs concentrate on a simple, manual measurement technique, since the procedures for the installation and use of proprietary, automatic equipment will be well-defined in the manufacturer's literature.
+
+Many ITU-T P.56 measuring instruments have analogue front-ends, and are therefore only capable of measuring signals that are in analogue format. Conversely, when performing signal level measurements within a network, it is best to extract the signal at a digital point (probably at the 2.048 Mbit/s or 1.544 Mbit/s multiplex level) since the relative level of a digital point within the network is clearly defined. Consequently, it is necessary to use proprietary equipment to extract the appropriate channel from a 2.048 Mbit/s or 1.544 Mbit/s stream, and convert the transmit and receive signals to analogue. The analogue signals may then be presented to the ITU-T P.56 measuring device.
+
+An example of how to measure speech signal levels within a network is given in Figure A.1. In this example, a proprietary signal monitor is connected to the transmit and receive points of a 2 Mbit/s digital monitor frame. The appropriate channel is selected, and the transmit and receive signals are converted to analogue by the monitoring equipment. The input impedance of the [ITU-T P.56] instruments is set to 600 ohms to ensure that the gain of the monitoring equipment is as specified by the equipment manufacturer. Typically, the gain of the monitoring equipment will be 0 dB; therefore, the relative level of the analogue measurement point will be equal to the relative level of the digital monitor point. The ITU-T P.56 instruments should be set to measure active level in dBm (600 ohms).
+
+NOTE 1 – In international networks, the signals are monitored on the international side of the echo canceller. This is so that echo signals do not influence the measurements taken. If no echo canceller is present, then care must be taken when interpreting the results.
+
+When taking measurements, the particular call should be monitored via headphones at the start to determine whether the call is speech or data. The measurement is then started by activating the
+
+ITU-T P.56 instrument, and after a suitable measurement period (suggest not less than 20 seconds) the measurement is stopped and the reading is noted.
+
+NOTE 2 – If the ITU-T P.56 device is controllable via a GPIB bus, the measurement process can be semi-automated if a separate PC is used as a controller. It is also possible that the ITU-T P.56 device itself is PC based, and may feature more than one measurement channel. Using such equipment, the measurement results can be logged automatically, but speech/data discrimination still has to take place. To preserve the simplicity of the measurement configuration, this latter aspect is probably best achieved by headphone monitoring, as before.
+
+![Diagram showing the setup for taking speech level measurements on a digital network. It illustrates the flow from a Digital Monitor Frame through a PCM Signal Monitor to two Speech Voltmeters via Analogue 600 Ω outputs.](dcb5711d118ae6753b0e12f86eda37db_img.jpg)
+
+The diagram illustrates the measurement setup. At the top, two horizontal lines represent network paths: the upper line is labeled 'Transmit' and the lower line is labeled 'Receive'. A dashed box labeled 'Digital Monitor Frame' is positioned over both lines, with tap points leading down to a 'PCM Signal Monitor' block. The connection from the receive line to the monitor is labeled 'Digital 2048/1544 kbit/s'. From the 'PCM Signal Monitor', two output lines extend downwards, labeled 'Analogue 600 Ω', and each connects to a 'Speech Voltmeter' block. A small identifier 'T1530280-98' is located to the right of the diagram.
+
+Diagram showing the setup for taking speech level measurements on a digital network. It illustrates the flow from a Digital Monitor Frame through a PCM Signal Monitor to two Speech Voltmeters via Analogue 600 Ω outputs.
+
+**Figure A.1 – Taking speech level measurements on a digital network**
+
+# Appendix I
+
+## **Guidance for the design of automatic level control (ALC) algorithms and their placement in the public switched telephone network (PSTN)**
+
+(This appendix does not form an integral part of this Recommendation.)
+
+## **I.1 Introduction**
+
+The control of speech levels in the telephone network is important for the listeners' comfort, and to ensure optimum performance of network equipment. Manufacturers of network signal processing equipment (e.g., echo cancellers) are developing automatic level control (ALC) algorithms as an option for network operators. This appendix discusses some of the issues relating to the design and operation of ALC algorithms and provides useful guidance for the designers of such algorithms and for network planners who are considering the introduction of ALC algorithms into the public switched telephone network (PSTN).
+
+## **I.2 Discussion**
+
+There are two basic reasons why the control of speech levels is important for telephony. The first is simply that people prefer speech to be at a comfortable level at which they are best able to understand it. Obviously, this 'preferred level' will vary from person to person, and will also be dependent to a certain extent on the level of background noise. Despite this, it is possible to select a listening level that is comfortable to the majority of people with normal hearing.
+
+The second reason why speech levels are important is one of equipment performance. Each active device, such as an amplifier or speech codec, will have a certain dynamic range over which it will function to specification; outside this range the performance may degrade rapidly, leading to noise and distortion of various types. For this reason, it is important to maintain speech levels within the dynamic range specified for the equipment.
+
+Traditionally, the strategy of the telecommunications providers has been to provide tight specifications for equipment and networks such that, for the large majority of calls, signal levels will lie within an acceptable range. Digitalization of the networks has assisted in this objective. However, customer expectations have increased, and other factors such as deregulation and competition have contributed to the difficulty of maintaining adequate control of levels. In recent times, international communications have increased dramatically, and the network operator has no direct control over the distant networks. The network operator must cope with increasing amounts of hands-free mobile telephony, and coupled with all these factors, there will always be a small percentage of very loud or very quiet talkers.
+
+In principle, the preferred listening level could be set by a volume control on the telephone instrument but, for historical reasons, few telephones are fitted with volume controls, even today. In any event, this would address only the listening level aspect, and would do nothing to ensure that network equipment is presented with the correct level. To assist in this latter respect, the level would need to be adjusted at an early point in the network. This suggests that some form of automatic level control (ALC) device should be installed at an appropriate point in the network, which would continuously monitor the transmitted level and adjust the gain accordingly. In other areas such techniques are far from new, used for example in the r.f. stages of radio receivers, and to control the microphone level in tape recorders. However, these processes have their limitations and drawbacks: a sound recording engineer will often reject ALC in favour of tried and trusted manual control! For the telephone network, the range of signals and services to be handled are wide, and it will be necessary to ensure that an ALC system does not sometimes degrade the performance for particular signals rather than enhance them.
+
+## **I.3 ALC considerations**
+
+Before new technology is introduced into the network, the telecommunications operator must ensure that it does not have an adverse effect on any aspect of the existing service. In this clause, the location of ALC is considered and a number of performance issues, objective and subjective, are raised.
+
+### **I.3.1 Location of ALC**
+
+If ALC is to be introduced, it should be installed at an early point in the transmission path so that all the subsequent network equipment can benefit from the level optimization. To derive maximum benefit, the ALC would need to be located at the earliest 4-wire point in the transmit path, so that level variation due to talker loudness, mouth-to-handset distance, telephone instrument variations, and local line loss are accommodated, and the ALC precedes all the active equipment in the 4-wire path. Ideally, the ALC would precede even the conversion to 64 kbit/s digital format, since it could then be designed to prevent peak-clipping of high level signals, and to minimize the deterioration in signal to quantization noise ratio resulting from the level adjustment. However, with regard to a rapid, large-scale upgrade, the cost implications of installing ALC at this location are likely to be prohibitive. Elsewhere in the national network, the provision of ALC alone is unlikely to be economically viable unless demands for advanced services and facilities lead to the widespread introduction of a general-purpose signal processing capability.
+
+The economics of providing ALC specifically for international circuits are more attractive, especially if use is made of existing signal processing equipment (e.g., echo cancellers) as a platform on which to implement ALC. The ALC equipment would be located in the transmit path at the international exchange; therefore, all active equipment in the international transmission path would benefit from the level control, but any in the preceding national part of the connection would not.
+
+### **I.3.2 Algorithmic and subjective considerations**
+
+With ALC installed after the conversion to 64 kbit/s digital format, as in the case of ALC at the international exchange, any clipping on a high level speech signal would remain even after the signal is attenuated by the ALC. This clipping distortion may even become subjectively more noticeable at the lower listening level. Also, any level adjustment will degrade the signal to quantization noise ratio to some extent, and this may tend to negate the subjective enhancement resulting from the level optimization.
+
+In the particular case of very low level speech signals for which the signal to quantization noise ratio is already reduced relative to a normal level signal due to the characteristics of A-law or  $\mu$ -law PCM, the quantization noise may become subjectively more disturbing after the signal is amplified by the ALC. This situation is similar to the case of a quiet talker in a high background noise environment such as a noisy office, or noisy vehicle in the case of a mobile telephone. Amplification of the speech may make the background noise more objectionable.
+
+Considering another aspect of the high background noise situation, it is crucial that the ALC should not interpret this noise as speech and amplify the noise to the normal listening level for speech. Such behaviour would clearly be disastrous for the call, causing massive gain oscillations triggered separately by the speech and speech pauses. However, the very high noise levels that can occur in the mobile environment, the spectral characteristics and variability of this noise, make foolproof ALC operation difficult to guarantee.
+
+Another subjective question concerns the effect ALC has on the speech dynamics and the consequent effect on a conversation. For example, a person may convey anger, excitement, regret, etc., by appropriately raising or lowering the voice, but this level change could be totally cancelled out by the ALC. The ALC gain characteristic and the choice of time constant within the ALC must, therefore, be selected very carefully in order to minimize the subjective impact of this unwanted effect. If the time constant is too short, it could lead to the loss of emphasis on words and phrases, and could also result in a pulsing effect on the speech level due to the gain adjustment becoming out-of-step with the speech energy. A long time constant is therefore preferred, but this will extend the time to adapt to a change in level due, for example, to a change of talker, changing from a handset to a loudspeaking telephone, or the start of a new call.
+
+The time taken to adjust the gain at the start of a new call is particularly important, and the ALC algorithm must be proved satisfactory in this respect. If the previous call was very quiet, the ALC will have adapted to introduce perhaps its maximum gain. If the new call is, in contrast, very loud, the combination of high level and high gain will give the listener an unpleasant acoustic shock. The painfully high signal level will persist until the ALC has made the appropriate adjustment to the gain. If, on the other hand, a low level call follows a high level one, the combination of low level and high attenuation could render the first few seconds of speech virtually inaudible. The listener might even assume the call had failed, and hang up.
+
+The large gain error that could exist at the start of a new call suggests that some form of rapid or step gain adjustment should come into play when the need for this is detected. The detection strategy would require careful design to prevent unwanted step gain changes during normal conversation, since such effects would be highly objectionable. However, the requirements for a rapid but very reliable decision are in conflict. It would, for example, be particularly difficult to quickly detect the need for a step increase in gain since the decision must be based upon the detection of a low speech level, and this implies measurement over an appreciable time interval. A quick decision would be highly unreliable.
+
+On subjective issues, there is one final sacrifice the users must be prepared to accept if they are to benefit from the introduction of ALC. For a listener in a noisy environment, or perhaps slightly hard of hearing, there would be little or no benefit in asking the talker to speak up, since the ALC would quickly compensate if the speaker obliged!
+
+### **I.3.3 Equipment issues**
+
+It has already been mentioned that a low level, poor signal-to-noise ratio speech signal may be subjectively less acceptable after amplification by the ALC. Such a signal, once amplified, may also be problematic for digital circuit multiplication equipment (DCME). One of the processes of DCME is digital speech interpolation (DSI), and therefore a voice activity detector (VAD) is required to detect the presence of speech on the incoming trunks. If the VAD uses simple level thresholds (as for the VAD example given in [ITU-T G.763] for DCME), the amplified, poor signal-to-noise ratio signal may be misinterpreted as continuous speech activity, and so affect the achievable channel multiplication of the DCME. Thus, although the performance of network equipment would often be enhanced by the use of ALC, there are specific situations where it may be detrimental.
+
+The preceding text has concentrated on issues concerning the operation of ALC with speech signals. However, a significant proportion of traffic is attributable to voiceband data and facsimile calls. The nature of these signals varies depending on the particular modulation scheme, and signals may be continuous or interrupted as in the case of the acknowledgement signal in the return direction of a facsimile call. The optimum mean level for such signals may be different to that for speech. In addition, the network must faithfully transport signalling tones. The ALC algorithm and its time constants must be shown not to disturb or degrade any of these transmissions. Alternatively, the means must be provided to automatically disable the ALC when these signals are being transmitted.
+
+### **I.3.4 Echo**
+
+Since the ALC is installed in the 4-wire loop, unwanted echo signals will be present, primarily due to reflections at the 2-to-4-wire interface. The consequence of the ALC adjusting its gain for the echo signal would have a devastating effect on the call. Steps must therefore be taken to prevent the ALC adjusting to echo signals. In the international network, the ALC could be installed in the transmit path after the echo canceller, so reducing the likelihood of the ALC adjusting to any residual echo signal. If ALC is installed before the echo canceller (or in a link without echo cancellers), robustness to echo will require additional complexity in the ALC algorithm, and a need to monitor the level of the receive path signal as well as the transmit path. In the case of ALC in the tail path of an echo canceller, the performance of the canceller will be impaired unless its adaptation speed is at least as fast as that of the ALC. Perhaps the most elegant and cost effective solution to the provision of ALC without susceptibility to echo is to design the ALC as an integral part of the echo canceller. Adaptation speed considerations could be accommodated, and the ability to monitor both directions of transmission would be intrinsic.
+
+### **I.3.5 Loop stability**
+
+Regardless of whether the ALC is installed in the national or international network, it will be located within the 4-wire transmission loop. This means that the maximum gain the ALC can introduce must be limited in order to preserve loop stability. It will be necessary to confirm that loop stability is guaranteed even with the maximum ALC gain and the worst-case loop conditions.
+
+The loop stability issue raises an important question regarding the possibility of encountering cascaded ALC systems. If two cascaded ALC systems each put in their maximum gain, the loop stability criterion may be breached. Either network planners must ensure cascaded ALC systems are never encountered, or a facility must be provided to automatically disable all but the first ALC system in the link.
+
+It must not be overlooked that ALC could often be installed in both directions of transmission. Where there are transmit and receive ALC systems at the same end of the transmission link (e.g., within an echo canceller), it might be advantageous to restrict the receive ALC to an attenuation function, so that it cannot introduce gain. This would allow the transmit ALC to insert the maximum gain consistent with loop stability. However, this maximum gain value must be halved if there is a possibility that an ALC device will exist in the transmit path at the opposite end of the transmission link (i.e., a balanced ALC system, offering equal benefits to the two transmission directions). The essential consideration is the total gain introduced into the 4-wire loop.
+
+# Appendix II
+
+## Considerations relating to ALC deployment
+
+(This appendix does not form an integral part of this Recommendation.)
+
+## II.1 Location of ALC
+
+![Simplified diagram of transmission network showing possible locations of ALC devices. The diagram shows a Digital Network connected to a Local Analogue Network. On the left, a Speech Compression (e.g. DCME) unit contains two ALC devices. In the center, an Echo Canceller unit contains two ALC devices and an Echo Canceller block. On the right, a D/A Decoder and an A/D Coder are shown, with an ALC device between them. The Local Analogue Network includes a resistor (R), a terminating unit (T), and a microphone/speaker symbol. A legend at the bottom left explains that 'Analogue pads – represent the nominal loss between the 2-wire point and the D/A or A/D, including the loss of the terminating unit.' The diagram is labeled T1530290-98.](b51423b6c049f5b5fcde42e50b58f18b_img.jpg)
+
+Simplified diagram of transmission network showing possible locations of ALC devices. The diagram shows a Digital Network connected to a Local Analogue Network. On the left, a Speech Compression (e.g. DCME) unit contains two ALC devices. In the center, an Echo Canceller unit contains two ALC devices and an Echo Canceller block. On the right, a D/A Decoder and an A/D Coder are shown, with an ALC device between them. The Local Analogue Network includes a resistor (R), a terminating unit (T), and a microphone/speaker symbol. A legend at the bottom left explains that 'Analogue pads – represent the nominal loss between the 2-wire point and the D/A or A/D, including the loss of the terminating unit.' The diagram is labeled T1530290-98.
+
+**Figure II.1 – Simplified diagram of transmission network showing possible locations of ALC devices**
+
+Figure II.1 illustrates the typical locations where ALC devices may be installed in a network. The diagram represents one end of a connection, and ALC devices may be installed in equivalent locations at the other end of the link. It is not intended to imply that it is desirable to have ALC devices at all of these locations. Indeed, the use of multiple ALC devices may cause stability problems (see 7.1), and ALC devices in cascade may lead to performance penalties for the level control function.
+
+In the case of the latter, these penalties arise because the rate of change of gain perceived by the listener will be increased if cascaded ALC devices are encountered, and gain overshoot effects may also occur. Also, if the first ALC device encountered introduces gain, the amplified circuit noise and background noise may then adversely affect the operation of subsequent ALC devices in the connection. Thus if an ALC device is installed in the send path of a connection, it is recommended that any ALC devices in the receive path at the other end of the link be disabled.
+
+In general, the earlier an ALC device occurs in a link, the greater the potential benefits are to the performance of network equipment. However, it may be economically advantageous to integrate the ALC device with an echo canceller [ITU-T G.165] and [ITU-T G.168]. Where choice permits, it is preferable to have an ALC device installed in the send path of a connection rather than in the receive path, since intermediate equipment may then benefit from the tighter control of levels. In principle, it is feasible to have an ALC device installed in the receive path, after the echo canceller. However, such a choice is unlikely, since the echo canceller itself would not then benefit from the level control.
+
+With due regard to the stability issues discussed in 7.1, it would be possible to use ALC devices in connections with echo suppressors (as opposed to echo cancellers). The performance tests described in the main text of this Recommendation should be made with the appropriate echo control device installed in the test circuit.
+
+Again with regard to the stability issues discussed in 7.1, and also with due regard to the echo performance of ALC devices discussed in 7.2, it would be possible to install an ALC device in the send direction of a national network. In many such networks, transmission delays are too short to justify the use of echo control devices for national calls. For reasons of stability, if the ALC device in the national network does not incorporate an in-built echo canceller, it may not be permitted to introduce as much gain as an ALC device in the international network (see 7.1, Stability).
+
+If an Administration chooses to install ALC devices in its national network, it raises the prospect of such an ALC device occurring in cascade with other ALC devices in the international network. Cascaded (tandemed) operation of ALC devices is undesirable for the reasons given above.
+
+Also, in an international connection, the ALC device in the national network may be in the tail-path of an echo canceller. This may affect the performance of the echo canceller because it introduces gain changes to the echo path. In the case of networks that use full echo cancellers, if the ALC device is not integrated into the design of the echo canceller, there is no alternative but to site the ALC device in a tail-path of the canceller. The use of ALC devices in networks incorporating full echo cancellers is for further study.
+
+## **II.2 Tandemed operation**
+
+There are significant issues relating to the tandemed operation of ALC devices. Until ALC devices have the capability of being disabled to prevent them from operating in tandem, they should be implemented in such a fashion that tandeming cannot occur.
+
+# Bibliography
+
+[b-AURORA] AURORA *Project Database 2.0*  
+<http://elda.org/article52.html>.
+
+
+
+# SERIES OF ITU-T RECOMMENDATIONS
+
+|                 |                                                                                             |
+|-----------------|---------------------------------------------------------------------------------------------|
+| Series A        | Organization of the work of ITU-T                                                           |
+| Series D        | General tariff principles                                                                   |
+| Series E        | Overall network operation, telephone service, service operation and human factors           |
+| Series F        | Non-telephone telecommunication services                                                    |
+| <b>Series G</b> | <b>Transmission systems and media, digital systems and networks</b>                         |
+| Series H        | Audiovisual and multimedia systems                                                          |
+| Series I        | Integrated services digital network                                                         |
+| Series J        | Cable networks and transmission of television, sound programme and other multimedia signals |
+| Series K        | Protection against interference                                                             |
+| Series L        | Construction, installation and protection of cables and other elements of outside plant     |
+| Series M        | Telecommunication management, including TMN and network maintenance                         |
+| Series N        | Maintenance: international sound programme and television transmission circuits             |
+| Series O        | Specifications of measuring equipment                                                       |
+| Series P        | Terminals and subjective and objective assessment methods                                   |
+| Series Q        | Switching and signalling                                                                    |
+| Series R        | Telegraph transmission                                                                      |
+| Series S        | Telegraph services terminal equipment                                                       |
+| Series T        | Terminals for telematic services                                                            |
+| Series U        | Telegraph switching                                                                         |
+| Series V        | Data communication over the telephone network                                               |
+| Series X        | Data networks, open system communications and security                                      |
+| Series Y        | Global information infrastructure, Internet protocol aspects and next-generation networks   |
+| Series Z        | Languages and general software aspects for telecommunication systems                        |
\ No newline at end of file
diff --git a/marked/G/T-REC-G.698.5-202401-I_PDF-E/raw.md b/marked/G/T-REC-G.698.5-202401-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..b000207ec3d55755c8ac71c370cc5dcfef36938f
--- /dev/null
+++ b/marked/G/T-REC-G.698.5-202401-I_PDF-E/raw.md
@@ -0,0 +1,511 @@
+
+
+# Recommendation**ITU-T G.698.5 (01/2024)**
+
+SERIES G: Transmission systems and media, digital systems and networks
+
+Transmission media and optical systems characteristics –  
+Characteristics of optical systems
+
+---
+
+## **Multichannel DWDM applications with single-channel optical interfaces in the O-band**
+
+![ITU logo](0538daaa5583c23e17db3a12f2281a55_img.jpg)
+
+The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue globe with white grid lines and the letters 'ITU' in a bold, blue, sans-serif font.
+
+ITU logo
+
+## ITU-T G-SERIES RECOMMENDATIONS
+
+## Transmission systems and media, digital systems and networks
+
+|                                                                                                                                              |                    |
+|----------------------------------------------------------------------------------------------------------------------------------------------|--------------------|
+| INTERNATIONAL TELEPHONE CONNECTIONS AND CIRCUITS                                                                                             | G.100-G.199        |
+| GENERAL CHARACTERISTICS COMMON TO ALL ANALOGUE CARRIER-TRANSMISSION SYSTEMS                                                                  | G.200-G.299        |
+| INDIVIDUAL CHARACTERISTICS OF INTERNATIONAL CARRIER TELEPHONE SYSTEMS ON METALLIC LINES                                                      | G.300-G.399        |
+| GENERAL CHARACTERISTICS OF INTERNATIONAL CARRIER TELEPHONE SYSTEMS ON RADIO-RELAY OR SATELLITE LINKS AND INTERCONNECTION WITH METALLIC LINES | G.400-G.449        |
+| COORDINATION OF RADIOTELEPHONY AND LINE TELEPHONY                                                                                            | G.450-G.499        |
+| TRANSMISSION MEDIA AND OPTICAL SYSTEMS CHARACTERISTICS                                                                                       | G.600-G.699        |
+| General                                                                                                                                      | G.600-G.609        |
+| Symmetric cable pairs                                                                                                                        | G.610-G.619        |
+| Land coaxial cable pairs                                                                                                                     | G.620-G.629        |
+| Submarine cables                                                                                                                             | G.630-G.639        |
+| Free space optical systems                                                                                                                   | G.640-G.649        |
+| Optical fibre cables                                                                                                                         | G.650-G.659        |
+| Characteristics of optical components and subsystems                                                                                         | G.660-G.679        |
+| <b>Characteristics of optical systems</b>                                                                                                    | <b>G.680-G.699</b> |
+| DIGITAL TERMINAL EQUIPMENTS                                                                                                                  | G.700-G.799        |
+| DIGITAL NETWORKS                                                                                                                             | G.800-G.899        |
+| DIGITAL SECTIONS AND DIGITAL LINE SYSTEM                                                                                                     | G.900-G.999        |
+| MULTIMEDIA QUALITY OF SERVICE AND PERFORMANCE – GENERIC AND USER-RELATED ASPECTS                                                             | G.1000-G.1999      |
+| TRANSMISSION MEDIA CHARACTERISTICS                                                                                                           | G.6000-G.6999      |
+| DATA OVER TRANSPORT – GENERIC ASPECTS                                                                                                        | G.7000-G.7999      |
+| PACKET OVER TRANSPORT ASPECTS                                                                                                                | G.8000-G.8999      |
+| ACCESS NETWORKS                                                                                                                              | G.9000-G.9999      |
+
+For further details, please refer to the list of ITU-T Recommendations.
+
+# Recommendation ITU-T G.698.5
+
+## Multichannel DWDM applications with single-channel optical interfaces in the O-band
+
+## Summary
+
+Recommendation ITU-T G.698.5 provides optical parameter values for physical layer interfaces of dense wavelength division multiplexing (DWDM) systems primarily intended for mobile fronthaul and metro applications in the O-band, optimized for 10-km and 20-km transmission distances. Applications are defined using optical interface parameters and values for single-channel interfaces of multichannel wavelength division multiplexing (WDM) optical systems in point-to-point applications. This Recommendation uses a system architecture comprising a head-end equipment (HEE) connecting to the tail-end equipment (TEE) through a black link. For mobile fronthaul applications, the HEE is in a central office while the TEE is in a remote antenna site. A single bidirectional transmission fibre is used in the black link to connect the HEE to the TEE. This version of the Recommendation includes bidirectional single-fibre WDM applications at 25 Gbit/s per channel with a nominal optical channel frequency spacing of 800 GHz.
+
+## History \*
+
+| Edition | Recommendation | Approval   | Study Group | Unique ID          |
+|---------|----------------|------------|-------------|--------------------|
+| 1.0     | ITU-T G.698.5  | 2024-01-13 | 15          | 11.1002/1000/15792 |
+
+## Keywords
+
+25G, application codes, black link, metro networks, multivendor, O-band, optical interfaces, optical networks, WDM.
+
+---
+
+\* To access the Recommendation, type the URL <https://handle.itu.int/> in the address field of your web browser, followed by the Recommendation's unique ID.
+
+## FOREWORD
+
+The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis.
+
+The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics.
+
+The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1.
+
+In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC.
+
+## NOTE
+
+In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party.
+
+## INTELLECTUAL PROPERTY RIGHTS
+
+ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process.
+
+As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at <http://www.itu.int/ITU-T/ipr/>.
+
+© ITU 2024
+
+All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU.
+
+## Table of Contents
+
+|                                                              | Page |
+|--------------------------------------------------------------|------|
+| 1 Scope.....                                                 | 1    |
+| 2 References.....                                            | 1    |
+| 3 Definitions .....                                          | 2    |
+| 3.1 Terms defined elsewhere .....                            | 2    |
+| 3.2 Terms defined in this Recommendation.....                | 2    |
+| 4 Abbreviations and acronyms .....                           | 3    |
+| 5 Conventions .....                                          | 3    |
+| 6 Classification of optical interfaces.....                  | 3    |
+| 6.1 Applications.....                                        | 3    |
+| 6.2 Reference points .....                                   | 4    |
+| 6.3 Nomenclature .....                                       | 5    |
+| 7 Transverse compatibility .....                             | 5    |
+| 8 Parameter definitions .....                                | 5    |
+| 8.1 General information.....                                 | 6    |
+| 8.2 Interface at point SS .....                              | 7    |
+| 8.3 Optical path from S <sub>s</sub> to R <sub>s</sub> ..... | 7    |
+| 8.4 Interface at point RS.....                               | 8    |
+| 9 Parameter values .....                                     | 8    |
+| 10 Optical safety considerations.....                        | 9    |
+
+
+
+# Recommendation ITU-T G.698.5
+
+## Multichannel DWDM applications with single-channel optical interfaces in the O-band
+
+# 1 Scope
+
+The purpose of this Recommendation is to provide optical interface specifications towards the realization of transversely compatible bidirectional dense wavelength division multiplexing (DWDM) systems in O-band, primarily intended for mobile fronthaul and metro applications.
+
+This Recommendation defines and provides values for optical interface parameters of point-to-point WDM applications on single-mode optical fibres through the use of the black link approach with both of the propagation directions sharing the same optical fibre end-to-end.
+
+This Recommendation uses a system architecture comprising a head-end equipment (HEE) connecting to the tail-end equipment (TEE) through a black link. For mobile fronthaul applications, the HEE is in a central office while the TEE is in a remote antenna site. A single bidirectional transmission fibre is used in the black link to connect the HEE to the TEE. This version of the Recommendation includes bidirectional single-fibre WDM applications at 25 Gbit/s per channel with a nominal optical channel frequency spacing of 800 GHz.
+
+For the applications in this version of the Recommendation, the black link does not contain optical amplifiers.
+
+This Recommendation describes bidirectional WDM systems that include the following features:
+
+- Operating wavelength band: the O-band;
+- Nominal optical channel frequency spacing: 800 GHz;
+- Nominal bit rate of signal channel: 25 Gbit/s;
+- Nominal transmission distances: 10 km and 20 km;
+- Maximum capacity: 6 bidirectional channels (at 12 wavelengths) at 25 Gbit/s.
+
+Specifications are organized according to application codes.
+
+# 2 References
+
+The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation.
+
+- [ITU-T G.650.2] Recommendation ITU-T G.650.2 (2015), *Definitions and test methods for statistical and non-linear related attributes of single-mode fibre and cable*
+- [ITU-T G.652] Recommendation ITU-T G.652 (2016), *Characteristics of a single-mode optical fibre and cable*.
+- [ITU-T G.664] Recommendation ITU-T G.664 (2012), *Optical safety procedures and requirements for optical transmission systems*.
+- [ITU-T G.671] Recommendation ITU-T G.671 (2019), *Transmission characteristics of optical components and subsystems*.
+
+- [ITU-T G.694.1] Recommendation ITU-T G.694.1 (2020), *Spectral grids for WDM applications: DWDM frequency grid.*
+- [ITU-T G.698.1] Recommendation ITU-T G.698.1 (2023), *Multichannel DWDM applications with single-channel optical interfaces.*
+- [ITU-T G.698.4] Recommendation ITU-T G.698.4 (2023), *Multichannel bi-directional DWDM applications with port agnostic single-channel optical interfaces.*
+- [ITU-T G.709.4] Recommendation ITU-T G.709.4/Y.1331.4 (2020), *OTU25 and OTU50 short-reach interfaces.*
+- [ITU-T G.957] Recommendation ITU-T G.957 (2006), *Optical interfaces for equipments and systems relating to the synchronous digital hierarchy.*
+- [ITU-T G.959.1] Recommendation ITU-T G.959.1 (2018), *Optical transport network physical layer interfaces.*
+- [ITU-T G.972] Recommendation ITU-T G.972 (2020), *Definition of terms relevant to optical fibre submarine cable systems.*
+- [IEC 60825-1] IEC 60825-1:2014, *Safety of laser products – Part 1: Equipment classification and requirements.*
+- [IEC 60825-2] IEC 60825-2:2021, *Safety of laser products – Part 2: Safety of optical fibre communication systems (OFCS).*
+
+# 3 Definitions
+
+## 3.1 Terms defined elsewhere
+
+This Recommendation uses the following terms defined elsewhere:
+
+- 3.1.1 Term defined in [ITU-T G.650.2]
+  - differential group delay.
+- 3.1.2 Terms defined in [ITU-T G.671]:
+  - channel insertion loss;
+  - channel spacing;
+  - reflectance;
+  - ripple.
+- 3.1.3 Term defined in [ITU-T G.694.1]:
+  - frequency grid.
+- 3.1.4 Term defined in [ITU-T G.957]:
+  - transverse compatibility.
+- 3.1.5 Terms defined in [ITU-T G.959.1]:
+  - optical tributary signal;
+  - optical tributary signal class NRZ 25G.
+- 3.1.6 Term defined in [ITU-T G.972]
+  - dense wavelength division multiplexing (DWDM).
+
+## 3.2 Terms defined in this Recommendation
+
+This Recommendation defines the following term:
+
+**3.2.1 receiver sensitivity:** The minimum value of average received power at point R to achieve a  $1 \times 10^{-10}$  BER.
+
+# 4 Abbreviations and acronyms
+
+This Recommendation uses the following abbreviations and acronyms:
+
+|                |                                                                   |
+|----------------|-------------------------------------------------------------------|
+| BER            | Bit Error Ratio                                                   |
+| DWDM           | Dense Wavelength Division Multiplexing                            |
+| FEC            | Forward Error Correction                                          |
+| HEE            | Head-End Equipment                                                |
+| NRZ            | Non-Return to Zero                                                |
+| OD             | Optical Demultiplexer                                             |
+| OM             | Optical Multiplexer                                               |
+| R <sub>s</sub> | Single-channel reference point at the black link tributary output |
+| S <sub>s</sub> | Single-channel reference point at the black link tributary input  |
+| TEE            | Tail-End Equipment                                                |
+| WDM            | Wavelength Division Multiplexing                                  |
+
+# 5 Conventions
+
+None.
+
+# 6 Classification of optical interfaces
+
+## 6.1 Applications
+
+This Recommendation provides the physical layer parameters and values for single-channel interfaces of WDM multichannel optical systems in physical point-to-point single-fibre applications. These WDM systems are primarily intended to be used in mobile fronthaul and metropolitan area networks for a variety of clients, services and protocols.
+
+The specification method in this Recommendation uses a black link approach which means that optical interface parameters for only (single-channel) optical tributary signals are specified at the HEE and the TEE. Additional specifications are provided for the black link parameters such as maximum attenuation, chromatic dispersion, ripple and polarization mode dispersion. The configurations in Figures 6-1 and 6-2 may coexist at the two ends of the black link and, as such, share the same application code. Implementers need to take care to coordinate the connection type of the transceiver and the black link.
+
+Figure 6-1 shows the linear black link approach for bidirectional transmission applications with two fibres connecting to each transceiver according to the wavelength channel plan specified in clause 8.2.2. For mobile fronthaul applications, the HEE is in a central office while the TEE is in a remote antenna site.
+
+![Figure 6-1: Linear black link approach for bidirectional transmission applications with two fibres connecting to each transceiver. The diagram shows a central 'Black link' containing a 'Fibre' for 'Bidirectional transmission'. On the left, an 'HEE' (Head-End Equipment) contains multiple transceivers, each with an 'Rx' (Receiver) and 'Tx' (Transmitter). Each transceiver is connected to the black link via two optical demultiplexers (OD/OM). The top transceiver's 'Tx' is connected to the black link through an OD/OM, and its 'Rx' is connected through another OD/OM. The bottom transceiver follows the same pattern. On the right, a 'TEE' (Terminal Equipment) also contains transceivers with 'Tx' and 'Rx' connected to the black link via OD/OMs. Reference points are marked: 'R_s' (Receiver signal input) and 'S_s' (Signal output) at each transceiver's interface with the black link. The diagram is labeled 'G.698.5(24)'.](a5ee5c23b6dc52ec1d724b76d5a5f58f_img.jpg)
+
+Figure 6-1: Linear black link approach for bidirectional transmission applications with two fibres connecting to each transceiver. The diagram shows a central 'Black link' containing a 'Fibre' for 'Bidirectional transmission'. On the left, an 'HEE' (Head-End Equipment) contains multiple transceivers, each with an 'Rx' (Receiver) and 'Tx' (Transmitter). Each transceiver is connected to the black link via two optical demultiplexers (OD/OM). The top transceiver's 'Tx' is connected to the black link through an OD/OM, and its 'Rx' is connected through another OD/OM. The bottom transceiver follows the same pattern. On the right, a 'TEE' (Terminal Equipment) also contains transceivers with 'Tx' and 'Rx' connected to the black link via OD/OMs. Reference points are marked: 'R\_s' (Receiver signal input) and 'S\_s' (Signal output) at each transceiver's interface with the black link. The diagram is labeled 'G.698.5(24)'.
+
+**Figure 6-1 – Linear black link approach for bidirectional transmission applications with two fibres connecting to each transceiver**
+
+Figure 6-2 shows the linear black link approach for bidirectional transmission applications with one fibre connecting to each transceiver according to the wavelength channel plan specified in clause 8.2.2.
+
+![Figure 6-2: Linear black link approach for bidirectional transmission applications with one fibre connecting to each transceiver. This diagram is similar to Figure 6-1 but shows a single fibre connecting each transceiver's 'Tx' and 'Rx' to the central 'Black link' via a single OD/OM unit. The 'HEE' and 'TEE' components and the internal 'Fibre' for 'Bidirectional transmission' remain the same. Reference points 'R_s' and 'S_s' are also indicated at the interfaces.](e6df2733626a85205c1db682e6259c46_img.jpg)
+
+Figure 6-2: Linear black link approach for bidirectional transmission applications with one fibre connecting to each transceiver. This diagram is similar to Figure 6-1 but shows a single fibre connecting each transceiver's 'Tx' and 'Rx' to the central 'Black link' via a single OD/OM unit. The 'HEE' and 'TEE' components and the internal 'Fibre' for 'Bidirectional transmission' remain the same. Reference points 'R\_s' and 'S\_s' are also indicated at the interfaces.
+
+**Figure 6-2 – Linear black link approach for bidirectional transmission applications with one fibre connecting to each transceiver**
+
+## 6.2 Reference points
+
+The system architecture comprises a HEE connecting to the TEE through a black link. The HEE houses a set of transmitters and receivers. A single bidirectional fibre or a pair of fibres is used to connect a pair of head-end transmitter (Tx) and receiver (Rx) with one or two ports of the black link. Both the HEE-side optical demultiplexer (OD) / optical multiplexer (OM) and the TEE-side OD/OM are considered to be part of the black link. The connection between the HEE-side OD/OM and the TEE-side OD/OM is bidirectional.
+
+The reference points in Figure 6-1 and Figure 6-2 are defined as follows:
+
+- $S_s$  is a single-channel reference point at the black link tributary input;
+- $R_s$  is a single-channel reference point at the black link tributary output.
+
+At the  $S_s$  interface, a single-channel signal enters the black link from an optical transmitter.
+
+At the  $R_s$  interface, a single-channel signal exits the black link towards an optical receiver.
+
+## 6.3 Nomenclature
+
+The application code notation is constructed as follows:
+
+$Lc-s-dD-y-tz$
+
+where:
+
+- L is the indicator of WDM applications defined in this Recommendation.
+- c is the number of channels.
+- s is a number giving the channel spacing in 100 GHz:
+  - 8 indicating 800 GHz spacing
+- d is a number indicating the span distance in km, such as:
+  - 10 indicating short-haul up to 10 km distance;
+  - 20 indicating short-haul up to 20 km distance.
+- D is the indicator of unidirectional or bidirectional transmission:
+  - B bidirectional transmission.
+- y indicates the highest class of optical tributary signal supported:
+  - 9 indicating NRZ 25G.
+- t indicates the configuration supported by the application code. In the current version of this Recommendation, the only value used is:
+  - D indicating that the black link does not contain any optical amplifiers.
+- z indicates the fibre types. In the current version of this Recommendation, the only value used is:
+  - 1 indicating ITU-T G.652 fibre.
+
+# 7 Transverse compatibility
+
+This Recommendation specifies parameters in order to enable transverse (i.e., multivendor) compatible line systems for point-to-point applications at single-channel reference points  $S_s$  and  $R_s$ .
+
+The single-channel reference points  $S_s$  and  $R_s$  are intended to make multiple tributary interfaces of WDM TEEs transversely compatible with the HEE. In this case, tributary signal transmitter ( $T_x \lambda_i$ ) and receiver ( $R_x \lambda_i$ ) pairs may be from different vendors. Thus, TEE, black link and HEE suppliers are not necessarily the same.
+
+# 8 Parameter definitions
+
+The parameters in Table 8-1 are defined at the interface points and the definitions are provided in the clauses below.
+
+**Table 8-1 – Physical layer parameters for multichannel bidirectional WDM applications**
+
+| Parameter                                                              | Units | For HEE to TEE defined in: | For TEE to HEE defined in: |
+|------------------------------------------------------------------------|-------|----------------------------|----------------------------|
+| <b>General information</b>                                             |       |                            |                            |
+| Bit-rate/line coding of optical tributary signals                      | –     | 8.1.1                      | 8.1.1                      |
+| Maximum bit-error ratio                                                | –     | 8.1.2                      | 8.1.2                      |
+| Fibre type                                                             | –     | 8.1.3                      | 8.1.3                      |
+| <b>Interface at point S<sub>s</sub></b>                                |       |                            |                            |
+| Maximum mean channel output power                                      | dBm   | 8.2.1                      | 8.2.1                      |
+| Minimum mean channel output power                                      | dBm   | 8.2.1                      | 8.2.1                      |
+| Minimum central frequency                                              | THz   | 8.2.2                      | 8.2.2                      |
+| Maximum central frequency                                              | THz   | 8.2.2                      | 8.2.2                      |
+| Maximum spectral excursion                                             | GHz   | 8.2.3                      | 8.2.3                      |
+| Minimum channel extinction ratio                                       | dB    | 8.2.4                      | 8.2.4                      |
+| Eye mask                                                               | –     | 8.2.5                      | 8.2.5                      |
+| <b>Optical path from S<sub>s</sub> to R<sub>s</sub></b>                |       |                            |                            |
+| Maximum channel insertion loss                                         | dB    | 8.3.1                      | 8.3.1                      |
+| Minimum channel insertion loss                                         | dB    | 8.3.1                      | 8.3.1                      |
+| Maximum ripple                                                         | dB    | 8.3.2                      | 8.3.2                      |
+| Chromatic dispersion range                                             | ps/nm | 8.3.3                      | 8.3.3                      |
+| Minimum optical return loss at S <sub>s</sub>                          | dB    | 8.3.4                      | 8.3.4                      |
+| Maximum discrete reflectance between S <sub>s</sub> and R <sub>s</sub> | dB    | 8.3.5                      | 8.3.5                      |
+| Maximum differential group delay                                       | ps    | 8.3.6                      | 8.3.6                      |
+| Maximum inter-channel crosstalk at R <sub>s</sub>                      | dB    | 8.3.7                      | 8.3.7                      |
+| Maximum interferometric crosstalk at R <sub>s</sub>                    | dB    | 8.3.8                      | 8.3.8                      |
+| <b>Interface at point R<sub>s</sub></b>                                |       |                            |                            |
+| Maximum mean channel input power                                       | dBm   | 8.4.1                      | 8.4.1                      |
+| Minimum mean channel input power                                       | dBm   | 8.4.1                      | 8.4.1                      |
+| Receiver sensitivity                                                   | dBm   | 8.4.2                      | 8.4.2                      |
+| Maximum optical path penalty                                           | dB    | 8.4.3                      | 8.4.3                      |
+| Maximum reflectance of receiver or optical network element             | dB    | 8.4.4                      | 8.4.4                      |
+
+## 8.1 General information
+
+### 8.1.1 Bit-rate/line coding of optical tributary signals
+
+The bit-rate/line coding of optical tributary signals is defined in [ITU-T G.959.1].
+
+### 8.1.2 Maximum bit-error ratio
+
+The maximum bit-error ratio is defined in [ITU-T G.698.1].
+
+### 8.1.3 Fibre type
+
+Currently, the only single-mode optical fibre type is that defined in [ITU-T G.652].
+
+## 8.2 Interface at point Ss
+
+### 8.2.1 Maximum and minimum mean channel output power
+
+The mean channel output power is defined in [ITU-T G.959.1].
+
+### 8.2.2 Minimum and maximum central frequency
+
+The central frequency is defined in [ITU-T G.698.1].
+
+For each optical channel, different ranges of frequencies are used in the head end (HE) to tail end (TE) and TE-to-HE directions. The channel frequencies in the two directions are paired.
+
+In application codes L12-8-10B-9-D1 and L12-8-20B-9-D1, the nominal bidirectional optical channel frequencies and their pairing are set according to Table 8-2.
+
+**Table 8-2 – Nominal bidirectional optical channel frequencies and their pairing for L12-8-10B-9-D1 and L12-8-20B-9-D1 applications codes**
+
+| Bidirectional channel | From HEE to TEE      |                         |                         | From TEE to HEE      |                         |                         |
+|-----------------------|----------------------|-------------------------|-------------------------|----------------------|-------------------------|-------------------------|
+|                       | Channel index (Note) | Central frequency (THz) | Central wavelength (nm) | Channel index (Note) | Central frequency (THz) | Central wavelength (nm) |
+| 1                     | $f_2$                | 235.4                   | 1273.54                 | $f_1$                | 236.2                   | 1269.23                 |
+| 2                     | $f_4$                | 233.8                   | 1282.26                 | $f_3$                | 234.6                   | 1277.89                 |
+| 3                     | $f_6$                | 232.2                   | 1291.10                 | $f_5$                | 233.0                   | 1286.66                 |
+| 4                     | $f_7$                | 231.4                   | 1295.56                 | $f_8$                | 230.6                   | 1300.05                 |
+| 5                     | $f_{10}$             | 229.0                   | 1309.14                 | $f_9$                | 229.8                   | 1304.58                 |
+| 6                     | $f_{12}$             | 227.4                   | 1318.35                 | $f_{11}$             | 228.2                   | 1313.73                 |
+
+NOTE –  $f_m = 237.0 - 0.8 \times m$  (THz),  $m = 1$  to 12; each pair of channels on the same row in Table 8-2 can share a single bidirectional fibre to reach their corresponding HEE/TEE Tx/Rx.
+
+### 8.2.3 Maximum spectral excursion
+
+The maximum spectral excursion is defined in [ITU-T G.698.1].
+
+### 8.2.4 Minimum channel extinction ratio
+
+The minimum channel extinction ratio is defined in [ITU-T G.698.1].
+
+### 8.2.5 Eye mask
+
+The eye mask is defined in [ITU-T G.959.1].
+
+## 8.3 Optical path from Ss to Rs
+
+### 8.3.1 Maximum and minimum channel insertion loss
+
+The channel insertion loss is defined in [ITU-T G.698.1].
+
+### 8.3.2 Maximum ripple
+
+The ripple is defined in [ITU-T G.698.1].
+
+### 8.3.3 Chromatic dispersion range
+
+This parameter defines the range between the minimum and the maximum values of the optical path chromatic dispersion that the system shall be able to tolerate.
+
+### 8.3.4 Minimum optical return loss at Ss
+
+The minimum optical return loss is defined in [ITU-T G.959.1].
+
+### 8.3.5 Maximum discrete reflectance between Ss and Rs
+
+The maximum discrete reflectance is defined in [ITU-T G.959.1].
+
+### 8.3.6 Maximum differential group delay
+
+The maximum differential group delay is defined in [ITU-T G.698.1]
+
+### 8.3.7 Maximum interchannel crosstalk at Rs
+
+The interchannel crosstalk is defined in [ITU-T G.698.1].
+
+### 8.3.8 Maximum interferometric crosstalk at Rs
+
+The interferometric crosstalk is defined in [ITU-T G.698.1].
+
+## 8.4 Interface at point Rs
+
+### 8.4.1 Maximum and minimum mean channel input power
+
+The mean channel input power is defined in [ITU-T G.959.1].
+
+### 8.4.2 Receiver sensitivity
+
+The receiver sensitivity is defined in [ITU-T G.698.1].
+
+### 8.4.3 Maximum optical path penalty
+
+The maximum optical path penalty is defined in [ITU-T G.698.1].
+
+### 8.4.4 Maximum reflectance of receiver or optical network element
+
+The maximum reflectance of receiver is defined in [ITU-T G.698.1]
+
+# 9 Parameter values
+
+Table 9-1 shows parameter values for L12-8-10B-9-D1 and L12-8-20B-9-D1 application codes.
+
+**Table 9-1 – Optical specifications for 10-km and 20-km application codes L12-8-10B-9-D1 and L12-8-20B-9-D1**
+
+| Parameter                                         | Units | L12-8-10B-9-D1                                     | L12-8-20B-9-D1 |
+|---------------------------------------------------|-------|----------------------------------------------------|----------------|
+| General information                               |       |                                                    |                |
+| Maximum numbers of channels                       | –     | 12                                                 |                |
+| Bit-rate/line coding of optical tributary signals | –     | 25.78125 Gb/s $\pm$ 100 ppm / 25G NRZ              |                |
+| Maximum bit error ratio (Note 1)                  | –     | $10^{-12}$                                         |                |
+| Fibre type                                        | –     | G.652                                              |                |
+| <b>Interface at point Ss</b>                      |       |                                                    |                |
+| Maximum mean channel output power                 | dBm   | 5.5                                                | 5.5            |
+| Minimum mean channel output power                 | dBm   | 0                                                  | 2              |
+| Central frequencies of all the channels           | THz   | $f_m = 237.0 - 0.8 \times m, m = 1 \text{ to } 12$ |                |
+| Central frequencies of the HE-to-TE channels      | –     | $f_2, f_4, f_6, f_7, f_{10}, f_{12}$               |                |
+
+**Table 9-1 – Optical specifications for 10-km and 20-km application codes L12-8-10B-9-D1 and L12-8-20B-9-D1**
+
+| Parameter                                                                                                                                                                         | Units | L12-8-10B-9-D1                    | L12-8-20B-9-D1 |  |  |
+|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------|-----------------------------------|----------------|--|--|
+| Central frequencies of the TE-to-HE channels                                                                                                                                      | –     | $f_1, f_3, f_5, f_8, f_9, f_{11}$ |                |  |  |
+| Maximum spectral excursion                                                                                                                                                        | GHz   | $\pm 200$                         |                |  |  |
+| Minimum channel extinction ratio                                                                                                                                                  | dB    | 3.5                               |                |  |  |
+| Eye mask                                                                                                                                                                          | –     | NRZ 25G Ratio                     |                |  |  |
+| <b>Optical path from point S<sub>s</sub> to R<sub>s</sub></b>                                                                                                                     |       |                                   |                |  |  |
+| Maximum channel insertion loss (Note 2)                                                                                                                                           | dB    | 10.7                              | 15.9           |  |  |
+| Minimum channel insertion loss (Note 2)                                                                                                                                           | dB    | 2.5                               | 2.5            |  |  |
+| Maximum ripple                                                                                                                                                                    | dB    | 2                                 |                |  |  |
+| Chromatic dispersion range                                                                                                                                                        | ps/nm | –50 to +15                        | –100 to +30    |  |  |
+| Minimum optical return loss at S <sub>s</sub>                                                                                                                                     | dB    | 20                                |                |  |  |
+| Maximum discrete reflectance between S <sub>s</sub> and R <sub>s</sub>                                                                                                            | dB    | –26                               |                |  |  |
+| Maximum differential group delay                                                                                                                                                  | ps    | 10.3                              |                |  |  |
+| Maximum inter-channel crosstalk at R <sub>s</sub>                                                                                                                                 | dB    | –25                               |                |  |  |
+| Maximum interferometric crosstalk at R <sub>s</sub>                                                                                                                               | dB    | –45                               |                |  |  |
+| <b>Interface at point R<sub>s</sub></b>                                                                                                                                           |       |                                   |                |  |  |
+| Maximum mean channel input power                                                                                                                                                  | dBm   | 3                                 | 3              |  |  |
+| Minimum mean channel input power                                                                                                                                                  | dBm   | –10.7                             | –13.9          |  |  |
+| Maximum optical path penalty (Note 3)                                                                                                                                             | dB    | 2                                 | 2.5            |  |  |
+| Receiver sensitivity (Note 4)                                                                                                                                                     | dBm   | –12.7                             | –16.4          |  |  |
+| Maximum reflectance of optical network element                                                                                                                                    | dB    | –26                               |                |  |  |
+| NOTE 1 – The BER for these application codes is required to be met only after RS10(528,514) has been applied, as in the OTU25u-RS FEC specification in [ITU-T G.709.4].           |       |                                   |                |  |  |
+| NOTE 2 – The channel insertion loss refers to the trunk optical path loss, containing the cabled optical fibre attenuation, connection and splice loss, and OM/OD insertion loss. |       |                                   |                |  |  |
+| NOTE 3 – The optical path penalty contains the penalties from chromatic dispersion, PMD, crosstalk and FWM.                                                                       |       |                                   |                |  |  |
+| NOTE 4 – The receiver sensitivity is measured with transmitter set at the maximum power and with the minimum optical return loss of the black link.                               |       |                                   |                |  |  |
+
+# 10 Optical safety considerations
+
+See [ITU-T G.664], [IEC 60825-1] and [IEC 60825-2] for optical safety considerations.
+
+
+
+
+
+## SERIES OF ITU-T RECOMMENDATIONS
+
+|                 |                                                                                                                                                           |
+|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Series A        | Organization of the work of ITU-T                                                                                                                         |
+| Series D        | Tariff and accounting principles and international telecommunication/ICT economic and policy issues                                                       |
+| Series E        | Overall network operation, telephone service, service operation and human factors                                                                         |
+| Series F        | Non-telephone telecommunication services                                                                                                                  |
+| <b>Series G</b> | <b>Transmission systems and media, digital systems and networks</b>                                                                                       |
+| Series H        | Audiovisual and multimedia systems                                                                                                                        |
+| Series I        | Integrated services digital network                                                                                                                       |
+| Series J        | Cable networks and transmission of television, sound programme and other multimedia signals                                                               |
+| Series K        | Protection against interference                                                                                                                           |
+| Series L        | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant |
+| Series M        | Telecommunication management, including TMN and network maintenance                                                                                       |
+| Series N        | Maintenance: international sound programme and television transmission circuits                                                                           |
+| Series O        | Specifications of measuring equipment                                                                                                                     |
+| Series P        | Telephone transmission quality, telephone installations, local line networks                                                                              |
+| Series Q        | Switching and signalling, and associated measurements and tests                                                                                           |
+| Series R        | Telegraph transmission                                                                                                                                    |
+| Series S        | Telegraph services terminal equipment                                                                                                                     |
+| Series T        | Terminals for telematic services                                                                                                                          |
+| Series U        | Telegraph switching                                                                                                                                       |
+| Series V        | Data communication over the telephone network                                                                                                             |
+| Series X        | Data networks, open system communications and security                                                                                                    |
+| Series Y        | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities                               |
+| Series Z        | Languages and general software aspects for telecommunication systems                                                                                      |
\ No newline at end of file
diff --git a/marked/G/T-REC-G.709-202006-I_PDF-E/raw.md b/marked/G/T-REC-G.709-202006-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..8eeb1dfc94f04ad92851f2c108a259f8695094a1
--- /dev/null
+++ b/marked/G/T-REC-G.709-202006-I_PDF-E/raw.md
@@ -0,0 +1,9270 @@
+
+
+International Telecommunication Union
+
+**ITU-T**
+
+**G.709/Y.1331**
+
+TELECOMMUNICATION  
+STANDARDIZATION SECTOR  
+OF ITU
+
+(06/2020)
+
+SERIES G: TRANSMISSION SYSTEMS AND MEDIA,  
+DIGITAL SYSTEMS AND NETWORKS
+
+Digital terminal equipments – General
+
+SERIES Y: GLOBAL INFORMATION  
+INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS,  
+NEXT-GENERATION NETWORKS, INTERNET OF  
+THINGS AND SMART CITIES
+
+Internet protocol aspects – Transport
+
+---
+
+**Interfaces for the optical transport network**
+
+Recommendation ITU-T G.709/Y.1331
+
+# ITU-T G-SERIES RECOMMENDATIONS **TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS**
+
+|                                                                                                                                              |                    |
+|----------------------------------------------------------------------------------------------------------------------------------------------|--------------------|
+| INTERNATIONAL TELEPHONE CONNECTIONS AND CIRCUITS                                                                                             | G.100–G.199        |
+| GENERAL CHARACTERISTICS COMMON TO ALL ANALOGUE CARRIER-TRANSMISSION SYSTEMS                                                                  | G.200–G.299        |
+| INDIVIDUAL CHARACTERISTICS OF INTERNATIONAL CARRIER TELEPHONE SYSTEMS ON METALLIC LINES                                                      | G.300–G.399        |
+| GENERAL CHARACTERISTICS OF INTERNATIONAL CARRIER TELEPHONE SYSTEMS ON RADIO-RELAY OR SATELLITE LINKS AND INTERCONNECTION WITH METALLIC LINES | G.400–G.449        |
+| COORDINATION OF RADIOTELEPHONY AND LINE TELEPHONY                                                                                            | G.450–G.499        |
+| TRANSMISSION MEDIA AND OPTICAL SYSTEMS CHARACTERISTICS                                                                                       | G.600–G.699        |
+| DIGITAL TERMINAL EQUIPMENTS                                                                                                                  | G.700–G.799        |
+| <b>General</b>                                                                                                                               | <b>G.700–G.709</b> |
+| Coding of voice and audio signals                                                                                                            | G.710–G.729        |
+| Principal characteristics of primary multiplex equipment                                                                                     | G.730–G.739        |
+| Principal characteristics of second order multiplex equipment                                                                                | G.740–G.749        |
+| Principal characteristics of higher order multiplex equipment                                                                                | G.750–G.759        |
+| Principal characteristics of transcoder and digital multiplication equipment                                                                 | G.760–G.769        |
+| Operations, administration and maintenance features of transmission equipment                                                                | G.770–G.779        |
+| Principal characteristics of multiplexing equipment for the synchronous digital hierarchy                                                    | G.780–G.789        |
+| Other terminal equipment                                                                                                                     | G.790–G.799        |
+| DIGITAL NETWORKS                                                                                                                             | G.800–G.899        |
+| DIGITAL SECTIONS AND DIGITAL LINE SYSTEM                                                                                                     | G.900–G.999        |
+| MULTIMEDIA QUALITY OF SERVICE AND PERFORMANCE – GENERIC AND USER-RELATED ASPECTS                                                             | G.1000–G.1999      |
+| TRANSMISSION MEDIA CHARACTERISTICS                                                                                                           | G.6000–G.6999      |
+| DATA OVER TRANSPORT – GENERIC ASPECTS                                                                                                        | G.7000–G.7999      |
+| PACKET OVER TRANSPORT ASPECTS                                                                                                                | G.8000–G.8999      |
+| ACCESS NETWORKS                                                                                                                              | G.9000–G.9999      |
+
+*For further details, please refer to the list of ITU-T Recommendations.*
+
+## Recommendation ITU-T G.709/Y.1331
+
+# Interfaces for the optical transport network
+
+## Summary
+
+Recommendation ITU-T G.709/Y.1331 defines the requirements for the optical transport network (OTN) interface signals of the optical transport network, in terms of:
+
+- OTN hierarchy
+- functionality of the overhead in support of multi-wavelength optical networks
+- frame structures
+- bit rates
+- formats for mapping client signals.
+
+Edition 6.0 of this Recommendation includes the text of Amendments 1, 2, 3, Corrigendum 1 and 2 to Edition 5.0 of this Recommendation, addition of 25 and 50 Gbit/s OTU, ODU and OPU frame formats and multiplexing of lower rate ODUk/flex signals into these two OPUs, extension of the supported ODUflex(IMP) bit rates to any rate, specification of frequency synchronous OTU and ODU and addition of a new appendix with examples of ODUflex(GFP) and ODUflex(IMP) clock generation methods. Edition 6.0 furthermore clarifies that the ODUflex(GFP) bit rate can be any rate and is not limited to the recommended bit rates, updates the OTN interface terminology, corrects the replacement signal definitions for some of the Ethernet client signals and restricts the FlexE aware sub-rate granularity to 25 Gbit/s.
+
+## History
+
+| Edition | Recommendation                   | Approval   | Study Group | Unique ID*                                                                |
+|---------|----------------------------------|------------|-------------|---------------------------------------------------------------------------|
+| 1.0     | ITU-T G.709/Y.1331               | 2001-02-09 | 15          | <a href="http://handle.itu.int/11.1002/1000/5350">11.1002/1000/5350</a>   |
+| 1.1     | ITU-T G.709/Y.1331 (2001) Amd. 1 | 2001-11-29 | 15          | <a href="http://handle.itu.int/11.1002/1000/5629">11.1002/1000/5629</a>   |
+| 2.0     | ITU-T G.709/Y.1331               | 2003-03-16 | 15          | <a href="http://handle.itu.int/11.1002/1000/6265">11.1002/1000/6265</a>   |
+| 2.1     | ITU-T G.709/Y.1331 (2003) Amd. 1 | 2003-12-14 | 15          | <a href="http://handle.itu.int/11.1002/1000/7060">11.1002/1000/7060</a>   |
+| 2.2     | ITU-T G.709/Y.1331 (2003) Cor. 1 | 2006-12-14 | 15          | <a href="http://handle.itu.int/11.1002/1000/8982">11.1002/1000/8982</a>   |
+| 2.3     | ITU-T G.709/Y.1331 (2003) Amd. 2 | 2007-11-22 | 15          | <a href="http://handle.itu.int/11.1002/1000/9155">11.1002/1000/9155</a>   |
+| 2.4     | ITU-T G.709/Y.1331 (2003) Cor.2  | 2009-01-13 | 15          | <a href="http://handle.itu.int/11.1002/1000/9646">11.1002/1000/9646</a>   |
+| 2.5     | ITU-T G.709/Y.1331 (2003) Amd. 3 | 2009-04-22 | 15          | <a href="http://handle.itu.int/11.1002/1000/9671">11.1002/1000/9671</a>   |
+| 3.0     | ITU-T G.709/Y.1331               | 2009-12-22 | 15          | <a href="http://handle.itu.int/11.1002/1000/10398">11.1002/1000/10398</a> |
+| 3.1     | ITU-T G.709/Y.1331 (2009) Cor. 1 | 2010-07-29 | 15          | <a href="http://handle.itu.int/11.1002/1000/10875">11.1002/1000/10875</a> |
+| 3.2     | ITU-T G.709/Y.1331 (2009) Amd. 1 | 2010-07-29 | 15          | <a href="http://handle.itu.int/11.1002/1000/10874">11.1002/1000/10874</a> |
+| 3.3     | ITU-T G.709/Y.1331 (2009) Amd. 2 | 2011-04-13 | 15          | <a href="http://handle.itu.int/11.1002/1000/11115">11.1002/1000/11115</a> |
+| 4.0     | ITU-T G.709/Y.1331               | 2012-02-13 | 15          | <a href="http://handle.itu.int/11.1002/1000/11485">11.1002/1000/11485</a> |
+| 4.1     | ITU-T G.709/Y.1331 (2012) Cor. 1 | 2012-10-29 | 15          | <a href="http://handle.itu.int/11.1002/1000/11776">11.1002/1000/11776</a> |
+| 4.2     | ITU-T G.709/Y.1331 (2012) Amd. 1 | 2012-10-29 | 15          | <a href="http://handle.itu.int/11.1002/1000/11774">11.1002/1000/11774</a> |
+| 4.3     | ITU-T G.709/Y.1331 (2012) Amd. 2 | 2013-10-22 | 15          | <a href="http://handle.itu.int/11.1002/1000/11982">11.1002/1000/11982</a> |
+| 4.4     | ITU-T G.709/Y.1331 (2012) Amd. 3 | 2014-12-05 | 15          | <a href="http://handle.itu.int/11.1002/1000/12363">11.1002/1000/12363</a> |
+| 4.5     | ITU-T G.709/Y.1331 (2012) Cor. 2 | 2015-01-13 | 15          | <a href="http://handle.itu.int/11.1002/1000/12365">11.1002/1000/12365</a> |
+| 4.6     | ITU-T G.709/Y.1331 (2012) Amd. 4 | 2015-01-13 | 15          | <a href="http://handle.itu.int/11.1002/1000/12364">11.1002/1000/12364</a> |
+| 5.0     | ITU-T G.709/Y.1331               | 2016-06-22 | 15          | <a href="http://handle.itu.int/11.1002/1000/12789">11.1002/1000/12789</a> |
+| 5.1     | ITU-T G.709/Y.1331 (2016) Amd. 1 | 2016-11-13 | 15          | <a href="http://handle.itu.int/11.1002/1000/13080">11.1002/1000/13080</a> |
+| 5.2     | ITU-T G.709/Y.1331 (2016) Cor. 1 | 2017-08-13 | 15          | <a href="http://handle.itu.int/11.1002/1000/13298">11.1002/1000/13298</a> |
+| 5.3     | ITU-T G.709/Y.1331 (2016) Amd. 2 | 2018-06-06 | 15          | <a href="http://handle.itu.int/11.1002/1000/13520">11.1002/1000/13520</a> |
+| 5.4     | ITU-T G.709/Y.1331 (2016) Amd. 3 | 2019-03-22 | 15          | <a href="http://handle.itu.int/11.1002/1000/13742">11.1002/1000/13742</a> |
+| 5.5     | ITU-T G.709/Y.1331 (2016) Cor. 2 | 2019-11-06 | 15          | <a href="http://handle.itu.int/11.1002/1000/13995">11.1002/1000/13995</a> |
+| 6.0     | ITU-T G.709/Y.1331               | 2020-06-06 | 15          | <a href="http://handle.itu.int/11.1002/1000/14199">11.1002/1000/14199</a> |
+
+## Keywords
+
+Client mappings, frame formats, multiplexing, OTN.
+
+\* To access the Recommendation, type the URL <http://handle.itu.int/> in the address field of your web browser, followed by the Recommendation's unique ID. For example, <http://handle.itu.int/11.1002/1000/1830-en>.
+
+# FOREWORD
+
+The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis.
+
+The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics.
+
+The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1.
+
+In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC.
+
+## NOTE
+
+In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party.
+
+## INTELLECTUAL PROPERTY RIGHTS
+
+ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process.
+
+As of the date of approval of this Recommendation, ITU had received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at <http://www.itu.int/ITU-T/ipr/>.
+
+© ITU 2020
+
+All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU.
+
+# Table of Contents
+
+|      |                                                                                                    | Page |
+|------|----------------------------------------------------------------------------------------------------|------|
+| 1    | Scope .....                                                                                        | 1    |
+| 2    | References.....                                                                                    | 1    |
+| 3    | Definitions .....                                                                                  | 3    |
+| 3.1  | Terms defined elsewhere .....                                                                      | 3    |
+| 3.2  | Terms defined in this Recommendation.....                                                          | 4    |
+| 4    | Abbreviations and acronyms .....                                                                   | 5    |
+| 5    | Conventions .....                                                                                  | 10   |
+| 6    | Optical transport network interface structure .....                                                | 11   |
+| 6.1  | Basic signal structure.....                                                                        | 11   |
+| 6.2  | Information structure for OTN interfaces.....                                                      | 13   |
+| 7    | Multiplexing/mapping principles and bit rates .....                                                | 15   |
+| 7.1  | Mapping.....                                                                                       | 16   |
+| 7.2  | Wavelength division multiplex.....                                                                 | 17   |
+| 7.3  | Bit rates and capacity.....                                                                        | 17   |
+| 7.4  | ODUk time-division multiplex.....                                                                  | 22   |
+| 7.5  | Interconnection of Ethernet UNI and FlexE Group UNI in two administrative domains in the OTN ..... | 32   |
+| 8    | OTN Interfaces .....                                                                               | 33   |
+| 8.1  | Point-to-point interface, type I .....                                                             | 33   |
+| 8.2  | Point-to-point interface, type II .....                                                            | 33   |
+| 8.3  | Optical networking interface, type II.....                                                         | 33   |
+| 8.4  | Optical networking interface, type I.....                                                          | 34   |
+| 9    | Media Element.....                                                                                 | 34   |
+| 10   | OCh and OTSiA .....                                                                                | 34   |
+| 10.1 | OCh.....                                                                                           | 34   |
+| 10.2 | Optical tributary signal assembly (OTSiA).....                                                     | 34   |
+| 11   | Optical transport unit (OTU) .....                                                                 | 34   |
+| 11.1 | OTUk (k=1,2,3,4,4-SC) frame structure .....                                                        | 35   |
+| 11.2 | Scrambling for OTUk (k=1,2,3,4).....                                                               | 36   |
+| 11.3 | OTUCn frame structure .....                                                                        | 36   |
+| 11.4 | OTU25 and OTU50 frame structure.....                                                               | 37   |
+| 12   | Optical data unit (ODU) .....                                                                      | 38   |
+| 12.1 | ODU frame structure .....                                                                          | 38   |
+| 12.2 | ODU bit rates and bit-rate tolerances .....                                                        | 38   |
+| 13   | Optical payload unit (OPU) .....                                                                   | 42   |
+| 14   | Overhead information carried over the OSC and OCC .....                                            | 43   |
+| 14.1 | OSC .....                                                                                          | 43   |
+
+|       |                                                                                                          | Page |
+|-------|----------------------------------------------------------------------------------------------------------|------|
+| 14.2  | OCC .....                                                                                                | 43   |
+| 15    | Overhead description .....                                                                               | 44   |
+| 15.1  | Types of overhead .....                                                                                  | 48   |
+| 15.2  | Trail trace identifier and access point identifier definition .....                                      | 50   |
+| 15.3  | OTS-O description.....                                                                                   | 51   |
+| 15.4  | OMS-O description .....                                                                                  | 52   |
+| 15.5  | OCh-O and OTSiG-O description .....                                                                      | 53   |
+| 15.6  | OTU/ODU frame alignment OH description .....                                                             | 54   |
+| 15.7  | OTU OH description .....                                                                                 | 55   |
+| 15.8  | ODU OH description.....                                                                                  | 61   |
+| 15.9  | OPU OH description.....                                                                                  | 75   |
+| 16    | Maintenance signals.....                                                                                 | 77   |
+| 16.1  | OTS maintenance signals .....                                                                            | 78   |
+| 16.2  | OMS maintenance signals .....                                                                            | 78   |
+| 16.3  | OCh and OTiSA maintenance signals .....                                                                  | 78   |
+| 16.4  | OTU maintenance signals.....                                                                             | 79   |
+| 16.5  | ODU maintenance signals .....                                                                            | 80   |
+| 16.6  | Client maintenance signal.....                                                                           | 82   |
+| 17    | Mapping of client signals .....                                                                          | 82   |
+| 17.1  | OPU client signal fail (CSF).....                                                                        | 83   |
+| 17.2  | Mapping of CBR2G5, CBR10G, CBR10G3 and CBR40G signals into<br>OPUk .....                                 | 83   |
+| 17.3  | Blank clause.....                                                                                        | 87   |
+| 17.4  | Mapping of GFP frames into OPUk (k=0,1,2,3,4,flex).....                                                  | 87   |
+| 17.5  | Mapping of test signal into OPU .....                                                                    | 88   |
+| 17.6  | Mapping of a non-specific client bit stream into OPUk.....                                               | 89   |
+| 17.7  | Mapping of other constant bit-rate signals with justification into OPUk.....                             | 90   |
+| 17.8  | Mapping a 1000BASE-X and FC-1200 signal via timing transparent<br>transcoding into OPUk .....            | 100  |
+| 17.9  | Mapping a supra-2.488 Gbit/s CBR signal into OPUflex using BMP .....                                     | 102  |
+| 17.10 | Mapping of packet client signals into OPUk.....                                                          | 105  |
+| 17.11 | Mapping of 64B/66B encoded packet client signals into OPUflex using<br>IMP .....                         | 105  |
+| 17.12 | Mapping of FlexE aware signals into OPUflex.....                                                         | 107  |
+| 17.13 | Mapping a 64B/66B PCS coded signal into OPUflex using BMP and 2-<br>bit alignment of 66B code words..... | 111  |
+| 18    | Blank clause.....                                                                                        | 116  |
+| 19    | Mapping ODUj signals into the ODTU signal and the ODTU into the OPUk<br>tributary slots .....            | 116  |
+| 19.1  | OPUk tributary slot definition .....                                                                     | 116  |
+
+|         | Page                                                                                            |     |
+|---------|-------------------------------------------------------------------------------------------------|-----|
+| 19.2    | ODTU definition .....                                                                           | 128 |
+| 19.3    | Multiplexing ODTU signals into the OPUk .....                                                   | 130 |
+| 19.4    | OPUk multiplex overhead and ODTU justification overhead .....                                   | 140 |
+| 19.5    | Mapping ODUj into ODTUjk .....                                                                  | 153 |
+| 19.6    | Mapping of ODUj into ODTUk.ts.....                                                              | 162 |
+| 20      | Mapping ODUk signals into the ODTUCn signal and the ODTUCn into the OPUCn tributary slots ..... | 167 |
+| 20.1    | OPUCn tributary slot definition .....                                                           | 167 |
+| 20.2    | ODTUCn definition.....                                                                          | 171 |
+| 20.3    | Multiplexing ODTUCn signals into the OPUCn.....                                                 | 172 |
+| 20.4    | OPUCn multiplex overhead and ODTU justification overhead.....                                   | 173 |
+| 20.5    | Mapping ODUk into ODTUCn.ts .....                                                               | 177 |
+| Annex A | – Forward error correction using 16-byte interleaved RS(255,239) codecs .....                   | 180 |
+| Annex B | – Adapting 64B/66B encoded clients via transcoding into 513B code blocks.....                   | 182 |
+| B.1     | Transmission order .....                                                                        | 182 |
+| B.2     | Client frame recovery .....                                                                     | 182 |
+| B.3     | Transcoding from 66B blocks to 513B blocks .....                                                | 183 |
+| B.4     | Link fault signalling .....                                                                     | 188 |
+| Annex C | – Adaptation of OTU3 and OTU4 over multichannel parallel interfaces .....                       | 189 |
+| Annex D | – Generic mapping procedure principles.....                                                     | 192 |
+| D.1     | Basic principle .....                                                                           | 192 |
+| D.2     | Applying GMP in OTN .....                                                                       | 195 |
+| D.3     | $C_m(t)$ encoding and decoding .....                                                            | 199 |
+| D.4     | $\Sigma C_{nD}(t)$ encoding and decoding .....                                                  | 205 |
+| Annex E | – Adaptation of parallel 64B/66B encoded clients .....                                          | 207 |
+| E.1     | Introduction .....                                                                              | 207 |
+| E.2     | Clients signal format.....                                                                      | 207 |
+| E.3     | Client frame recovery .....                                                                     | 207 |
+| E.4     | Additions to Annex B transcoding for parallel 40GBASE-R clients .....                           | 210 |
+| Annex F | – Improved robustness for mapping of 40GBASE-R into OPU3 using 1027B code blocks .....          | 213 |
+| F.1     | Introduction .....                                                                              | 213 |
+| F.2     | 513B code block framing and flag bit protection.....                                            | 213 |
+| F.3     | 66B block sequence check.....                                                                   | 214 |
+| Annex G | – Mapping ODU0 into a low latency OTU0 (OTU0LL) .....                                           | 219 |
+| G.1     | Introduction .....                                                                              | 219 |
+| G.2     | Optical transport unit 0 low latency (OTU0LL).....                                              | 219 |
+| Annex H | – OTUCn sub rates (OTUCn-M).....                                                                | 222 |
+| H.1     | Introduction .....                                                                              | 222 |
+
+|                                                                                                                                                                                                                         | Page |
+|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------|
+| H.2 OTUCn-M frame format .....                                                                                                                                                                                          | 222  |
+| Annex I .....                                                                                                                                                                                                           | 223  |
+| Annex J – Recovery of 64B/66B encoded clients from parallel 256B/257B interfaces .....                                                                                                                                  | 224  |
+| Annex K – Transporting 200GbE and 400GbE am_sf<2:0> information through a single optical link between two Ethernet/OTN transponder entities in the OTN .....                                                            | 226  |
+| K.1 Introduction .....                                                                                                                                                                                                  | 226  |
+| K.2 Client Degrade Indication (CDI) overhead .....                                                                                                                                                                      | 227  |
+| Annex L – OTU25u and OTU50u interfaces.....                                                                                                                                                                             | 228  |
+| L.1 Introduction .....                                                                                                                                                                                                  | 228  |
+| L.2 Bit rates.....                                                                                                                                                                                                      | 228  |
+| Appendix I – Range of stuff ratios for asynchronous mappings of CBR2G5, CBR10G, and CBR40G clients with $\pm 20$ ppm bit-rate tolerance into OPUk, and for asynchronous multiplexing of ODUj into ODUk ( $k > j$ )..... | 231  |
+| Appendix II – Examples of functionally standardized OTU frame structures .....                                                                                                                                          | 237  |
+| Appendix III – Example of ODUk multiplexing .....                                                                                                                                                                       | 240  |
+| Appendix IV – Blank appendix .....                                                                                                                                                                                      | 242  |
+| Appendix V – ODUk multiplex structure identifier (MSI) examples .....                                                                                                                                                   | 243  |
+| Appendix VI – Parallel logic implementation of the CRC-9, CRC-8, CRC-5 and CRC-6 .....                                                                                                                                  | 246  |
+| Appendix VII – OTL4.10 structure.....                                                                                                                                                                                   | 249  |
+| Appendix VIII – CPRI into ODU mapping .....                                                                                                                                                                             | 250  |
+| Appendix IX – Overview of CBR clients into OPU mapping types .....                                                                                                                                                      | 251  |
+| Appendix X – Overview of ODUj into OPUk mapping types .....                                                                                                                                                             | 253  |
+| Appendix XI – Derivation of recommended ODUflex(GFP) bit-rates based on $n \times$ ODUk.ts clock and examples of ODUflex(GFP,n,k) clock generation.....                                                                 | 255  |
+| XI.1 Introduction .....                                                                                                                                                                                                 | 255  |
+| XI.2 Tributary slot sizes .....                                                                                                                                                                                         | 255  |
+| XI.3 Example methods for ODUflex(GFP,n,k) clock generation .....                                                                                                                                                        | 258  |
+| Appendix XII – Terminology changes between ITU-T G.709 Edition 4, Edition 5 and Edition 6 .....                                                                                                                         | 260  |
+| Appendix XIII – OTUCn sub rates (OTUCn-M) Applications .....                                                                                                                                                            | 262  |
+| XIII.1 Introduction .....                                                                                                                                                                                               | 262  |
+| XIII.2 OTUCn-M frame format and rates .....                                                                                                                                                                             | 262  |
+| XIII.3 OTUCn-M fault condition.....                                                                                                                                                                                     | 263  |
+| Appendix XIV – Examples of interconnection of Ethernet UNI and FlexE Group UNI in two administrative domains in the OTN for the case that these UNIs deploy different mapping methods .....                             | 264  |
+| Appendix XV – Examples of ODUflex(GFP) and ODUflex(IMP) clock generation methods.....                                                                                                                                   | 267  |
+| Bibliography.....                                                                                                                                                                                                       | 269  |
+
+# Interfaces for the optical transport network
+
+# 1 Scope
+
+The optical transport network (OTN) supports the operation and management aspects of optical networks of various architectures, e.g., point-to-point, ring and mesh architectures.
+
+This Recommendation defines the interfaces of the OTN to be used within and between subnetworks of the optical network, in terms of:
+
+- OTN hierarchy;
+- functionality of the overhead in support of multi-wavelength optical networks;
+- frame structures;
+- bit rates;
+- formats for mapping client signals.
+
+Functions and process flows associated with the defined interfaces are specified in [ITU-T G.798].
+
+The interfaces defined in this Recommendation can be applied at user-to-network interfaces (UNI) and network node interfaces (NNI) of the OTN.
+
+# 2 References
+
+The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation.
+
+- [ITU-T G.652] Recommendation ITU-T G.652 (2016), *Characteristics of a single-mode optical fibre and cable*.
+- [ITU-T G.693] Recommendation ITU-T G.693 (2009), *Optical interfaces for intra-office systems*.
+- [ITU-T G.695] Recommendation ITU-T G.695 (2018), *Optical interfaces for coarse wavelength division multiplexing applications*.
+- [ITU-T G.698.1] Recommendation ITU-T G.698.1 (2009), *Multichannel DWDM applications with single-channel optical interfaces*.
+- [ITU-T G.698.2] Recommendation ITU-T G.698.2 (2018), *Amplified multichannel dense wavelength division multiplexing applications with single channel optical interfaces*.
+- [ITU-T G.698.3] Recommendation ITU-T G.698.3 (2012), *Multichannel seeded DWDM applications with single-channel optical interfaces*.
+- [ITU-T G.707] Recommendation ITU-T G.707/Y.1322 (2007), *Network node interface for the synchronous digital hierarchy (SDH)*.
+- [ITU-T G.709.1] Recommendation ITU-T G.709.1/Y.1331.1 (2018), *Flexible OTN short-reach interfaces*.
+
+- [ITU-T G.709.3] Recommendation ITU-T G.709.3/Y.1331.3 (2018), *Flexible OTN long-reach interfaces*.
+- [ITU-T G.709.4] Recommendation ITU-T G.709.4/Y.1334.4 (2020), *OTU25 and OTU50 short-reach interfaces*.
+- [ITU-T G.780] Recommendation ITU-T G.780/Y.1351 (2010), *Terms and definitions for synchronous digital hierarchy (SDH) networks*.
+- [ITU-T G.798] Recommendation ITU-T G.798 (2017), *Characteristics of optical transport network hierarchy equipment functional blocks*.
+- [ITU-T G.805] Recommendation ITU-T G.805 (2000), *Generic functional architecture of transport networks*.
+- [ITU-T G.806] Recommendation ITU-T G.806 (2012), *Characteristics of transport equipment – Description methodology and generic functionality*.
+- [ITU-T G.807] Recommendation ITU-T G.807 (2020), *Generic functional architecture of the optical media network*.
+- [ITU-T G.870] Recommendation ITU-T G.870/Y.1352 (2016), *Terms and definitions for optical transport networks (OTN)*.
+- [ITU-T G.872] Recommendation ITU-T G.872 (2019), *Architecture of optical transport networks*.
+- [ITU-T G.873.1] Recommendation ITU-T G.873.1 (2014), *Optical Transport Network (OTN): Linear protection.2017*
+- [ITU-T G.873.2] Recommendation ITU-T G.873.2 (2015), *ODUk shared ring protection (SRP)*.
+- [ITU-T G.959.1] Recommendation ITU-T G.959.1 (2018), *Optical transport network physical layer interfaces*.
+- [ITU-T G.984.6] Recommendation ITU-T G.984.6 (2008), *Gigabit-capable passive optical networks (GPON): Reach extension*.
+- [ITU-T G.987.4] Recommendation ITU-T G.987.4 (2012), *10 Gigabit-capable passive optical networks (XG-PON): Reach extension*.
+- [ITU-T G.7041] Recommendation ITU-T G.7041/Y.1303 (2016), *Generic framing procedure (GFP)*.
+- [ITU-T G.7044] Recommendation ITU-T G.7044/Y.1347 (2011), *Hitless Adjustment of ODUflex(GFP)*.
+- [ITU-T G.7712] Recommendation ITU-T G.7712/Y.1703 (2019), *Architecture and specification of data communication network*.
+- [ITU-T G.7714.1] Recommendation ITU-T G.7714.1/Y.1705.1 (2010), *Protocol for automatic discovery in SDH and OTN networks*.
+- [ITU-T G.8260] Recommendation ITU-T G.8260 (2015), *Definitions and terminology for synchronization in packet networks*.
+- [ITU-T G.8262] Recommendation ITU-T G.8262/Y.1362 (2018), *Timing characteristics of a synchronous equipment slave clock*.
+- [ITU-T G.8264] Recommendation ITU-T G.8264 (2017), *Distribution of timing information through packet networks*.
+
+|                |                                                                                                                                                                                                                   |
+|----------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| [ITU-T M.1400] | Recommendation ITU-T M.1400 (2001), <i>Designations for interconnections among operators' networks</i> .                                                                                                          |
+| [ITU-T M.3100] | Recommendation ITU-T M.3100 (2004), <i>Generic network information model</i> .                                                                                                                                    |
+| [ITU-T O.150]  | Recommendation ITU-T O.150 (1996), <i>General requirements for instrumentation for performance measurements on digital transmission equipment</i> .                                                               |
+| [ITU-T T.50]   | Recommendation ITU-T T.50 (1992), <i>International Reference Alphabet (IRA) (Formerly International Alphabet No. 5 or IA5) – Information technology – 7-bit coded character set for information interchange</i> . |
+| [IEEE 802.3]   | IEEE Std. 802.3:2018, <i>Standard for Ethernet</i> .                                                                                                                                                              |
+| [IEEE 802.3cd] | IEEE Std 802.3cd-2018, <i>Standard for Ethernet Amendment 3: Media Access Control Parameters for 50 Gb/s and Physical Layers and Management Parameters for 50 Gb/s, 100 Gb/s, and 200 Gb/s Operation</i>          |
+| [OIF FlexE IA] | OIF, <i>Flex Ethernet 2.0 Implementation Agreement</i> (2018).                                                                                                                                                    |
+
+# 3 Definitions
+
+## 3.1 Terms defined elsewhere
+
+This Recommendation uses the following terms defined elsewhere:
+
+### 3.1.1 Terms defined in [ITU-T G.780]:
+
+- BIP-X
+- network node interface
+
+### 3.1.2 Terms defined in [ITU-T G.805]:
+
+- adapted information (AI)
+- characteristic information (CI)
+- network
+- subnetwork
+
+### 3.1.4 Terms defined in [ITU-T G.872]:
+
+- optical multiplex section (OMS)
+- optical transmission section (OTS)
+
+### 3.1.5 Terms defined in [ITU-T G.959.1]:
+
+- optical tributary signal (OTSi).
+
+### 3.1.6 Terms defined in [OIF FlexE IA]:
+
+- FlexE Client
+
+### 3.1.7 Terms defined in [ITU-T G.807]:
+
+- optical signal maintenance entity (OSME)
+
+## 3.2 Terms defined in this Recommendation
+
+This Recommendation defines the following terms:
+
+**3.2.1 ODUk.ts:** The ODUk.ts is an increment of bandwidth which when multiplied by a number of tributary slots gives the recommended size of an ODUflex(GFP,n,k) optimized to occupy a given number of tributary slots of an OPUk.
+
+**3.2.2 OTU0 low latency:** The OTU0 low latency (OTU0LL) is the information structure used for transport of an ODU0 over a multi-vendor optical network interface in one administrative domain at the edge of the optical transport network.
+
+**3.2.3 optical tributary signal assembly (OTSiA):** The OTSiG together with the non-associated overhead (OTSiG-O).
+
+**3.2.4 optical tributary signal group (OTSiG):** The set of OTSi signals that supports an OTU.
+
+**3.2.5 optical tributary signal overhead (OTSiG-O):** The non-associated overhead for an OTSiG.
+
+**3.2.6 connection monitoring end-point (CMEP):** Connection monitoring end-points represent end-points of trails and correspond as such with the trail termination functions. Connection monitoring overhead (CMOH) is inserted and extracted at the CMEPs.
+
+For the ODU and OTU the CMEPs are categorized in three classes:
+
+- OTU section CMEP (OS\_CMEP), which represents the end-points of the OTUk/OTUCn trail. The SM overhead field contains the related CMOH.
+- ODU tandem connection CMEP (TC\_CMEP), which represents the end-points of ODUkT/ODUCnT trails. The TCM1..6 overhead fields contain the related CMOH.
+- ODU path CMEP (P\_CMEP), which represents the end-points of the ODUkP/ODUCnP trail. The PM overhead field contains the related CMOH.
+
+**3.2.7 non-associated overhead:** Supervisory information transported in an optical supervisory signal, overhead communication channel or other means.
+
+**3.2.8 optical data unit (ODU):** The ODU is an information structure consisting of the information payload (OPU) and ODU related overhead, either as ODUk or ODUCn.
+
+**3.2.9 optical payload unit (OPU):** The OPU is the information structure used to adapt client information for transport over the OTN, either as an OPUk or an OPUCn. It comprises client information together with any overhead needed to perform rate adaptation between the client signal rate and the OPU payload rate, and other OPU overheads supporting the client signal transport. The index k or Cn (see clause 5) is used to identify the approximate bit rate and different versions.
+
+**3.2.10 optical transport unit (OTU):** The OTU is the information structure used for transport of an ODU over an OTSiA or OCh, either as an OTUk or an OTUCn.
+
+For OCh and OTN point-to-point interface cases, the OTU overhead is used as overhead for the transport over the optical layer, and the OTU must terminate where the OCh and OTN point-to-point interface is terminated. For an OTSiA, the OTU overhead may or may not be terminated where the OTSiA is terminated.
+
+Three versions of the OTUk are defined: completely standardized OTUk (OTUk), functionally standardized OTUk (OTUkV) and an OTUk with completely standardized overhead and functionally standardized FEC (OTUk-v). The completely standardized OTUk is used on OTN IrDIs and may be used on OTN IaDIs. The other two are used on OTN IaDIs.
+
+**3.2.11 OCh:** The OCh is an information structure consisting of the information payload (OTSiG) with a certain bandwidth and non-associated overhead (OCh-O) for management of the OCh.
+
+**3.2.12 optical transport network:** An optical transport network (OTN) is composed of a set of optical network elements connected by optical fibres, that provide functionality to encapsulate, transport, multiplex, route, manage, supervise and provide survivability of client signals. The information of the client signals is processed in the digital domain and carried across the media, according to the requirements given in [ITU-T G.872].
+
+**3.2.13 optical transport network node interface (ONNI):** The interface at an optical transport network node which is used to interconnect with another optical transport network node.
+
+**3.2.14 ODUflex(GFP):** ODUflex for GFP-F mapped client signals with user configured bit rate.
+
+**3.2.15 ODUflex(GFP,n,k):** ODUflex for GFP-F mapped client signals with user configured bit rate of  $n \times \text{ODUk.ts}$  in which  $n$  = number of 1.25G tributary slots and  $k$  = ODUk.ts representative.
+
+ODUflex(GFP,n,k) is a subset of ODUflex(GFP).
+
+**3.2.16 ODUflex(IMP):** ODUflex for IMP mapped client signals with user configured bit rate.
+
+**3.2.17 ODUflex(IMP,s):** ODUflex for IMP mapped client signals with bit rate of  $s \times 239/238 \times 5\ 156\ 250\ \text{kbit/s} \pm 100\ \text{ppm}$  in which  $s = 2, 8, n \times 5$  with  $n \geq 1$ .
+
+ODUflex(IMP,s) is a subset of ODUflex(IMP).
+
+# 4 Abbreviations and acronyms
+
+This Recommendation uses the following abbreviations and acronyms:
+
+|       |                                              |
+|-------|----------------------------------------------|
+| 16FS  | 16 columns with Fixed Stuff                  |
+| 3R    | Reamplification, Reshaping and Retiming      |
+| AI    | Adapted Information                          |
+| AIS   | Alarm Indication Signal                      |
+| AMP   | Asynchronous Mapping Procedure               |
+| API   | Access Point Identifier                      |
+| APS   | Automatic Protection Switching               |
+| ASI   | Asynchronous Serial Interface for DVB        |
+| BDI   | Backward Defect Indication                   |
+| BDI-O | Backward Defect Indication Overhead          |
+| BDI-P | Backward Defect Indication Payload           |
+| BEI   | Backward Error Indication                    |
+| BI    | Backward Indication                          |
+| BIAE  | Backward Incoming Alignment Error            |
+| BIP   | Bit Interleaved Parity                       |
+| BMP   | Bit-synchronous Mapping Procedure            |
+| CAUI  | (Chip to) 100 Gb/s Attachment Unit Interface |
+| CB    | Control Block                                |
+| CBR   | Constant Bit Rate                            |
+| CI    | Characteristic Information                   |
+| CM    | Connection Monitoring                        |
+
+|               |                                                  |
+|---------------|--------------------------------------------------|
+| $C_m$         | number of m-bit Client data entities             |
+| CMEP          | Connection Monitoring End Point                  |
+| CMGPON_D      | Continuous Mode GPON Downstream                  |
+| CMGPON_U2     | Continuous Mode GPON Upstream 2                  |
+| CMOH          | Connection Monitoring Overhead                   |
+| CMXGPON_D     | Continuous Mode XGPON Downstream                 |
+| CMXGPON_U2    | Continuous Mode XGPON Upstream 2                 |
+| $C_n$         | number of n-bit client data entities             |
+| $C_{nb}$      | difference between $C_n$ and $(m/n \times C_m)$  |
+| CPRI          | Common Public Radio Interface                    |
+| CRC           | Cyclic Redundancy Check                          |
+| CS            | Client Specific                                  |
+| CSF           | Client Signal Fail                               |
+| CTRL          | Control word sent from source to sink            |
+| DAPI          | Destination Access Point Identifier              |
+| DDR           | Double Data Rate                                 |
+| DMp           | Delay Measurement of ODUk path                   |
+| DMti          | Delay Measurement of TCMi                        |
+| DNU           | Do Not Use                                       |
+| DVB           | Digital Video Broadcast                          |
+| EDC           | Error Detection Code                             |
+| EOS           | End Of Sequence                                  |
+| ESCON         | Enterprise Systems Connection                    |
+| eSSM          | enhanced Synchronization Status Message          |
+| EXP           | Experimental                                     |
+| ExTI          | Expected Trace Identifier                        |
+| FA            | Frame Alignment                                  |
+| FAS           | Frame Alignment Signal                           |
+| FC            | Fibre Channel                                    |
+| FC            | Flag Continuation                                |
+| FDI           | Forward Defect Indication                        |
+| FDI-O         | Forward Defect Indication Overhead               |
+| FDI-P         | Forward Defect Indication Payload                |
+| FEC           | Forward Error Correction                         |
+| FlexO         | Flexible OTN information structure               |
+| FlexO-x       | FlexO interface information structure of order x |
+| FlexO-x-<fec> | FlexO interface signal of order x with a FEC     |
+
+|                 |                                                           |
+|-----------------|-----------------------------------------------------------|
+| FlexO-x-<fec>-m | Group of $m \times$ FlexO-x-<fec> interfaces              |
+| GCC             | General Communication Channel                             |
+| GID             | Group Identification                                      |
+| GMP             | Generic Mapping Procedure                                 |
+| GPON            | Gigabit-capable Passive Optical Networks                  |
+| IAE             | Incoming Alignment Error                                  |
+| IB              | InfiniBand                                                |
+| IMP             | Idle Mapping Procedure                                    |
+| IP              | Internet Protocol                                         |
+| JC              | Justification Control                                     |
+| JOH             | Justification Overhead                                    |
+| LF              | Local Fault                                               |
+| LLM             | Logical Lane Marker                                       |
+| LSB             | Least Significant Bit                                     |
+| MFAS            | MultiFrame Alignment Signal                               |
+| MFI             | Multiframe Indicator                                      |
+| MPLS            | Multi Protocol Label Switching                            |
+| MPLS-TP         | Multi Protocol Label Switching – Transport Profile        |
+| MS              | Maintenance Signal                                        |
+| MSB             | Most Significant Bit                                      |
+| MSI             | Multiplex Structure Identifier                            |
+| NJO             | Negative Justification Opportunity                        |
+| NNI             | Network Node Interface                                    |
+| NOS             | Not_Operational Sequence                                  |
+| OCC             | Overhead Communication Channel                            |
+| OCI             | Open Connection Indication                                |
+| OCN             | Overhead Communication Network                            |
+| ODTUG           | Optical Data Tributary Unit Group                         |
+| ODTUGk/Cn       | Optical Data Tributary Unit Group-k/Cn                    |
+| ODTUjk          | Optical Data Tributary Unit j into k                      |
+| ODTUk/Cn.ts     | Optical Data Tributary Unit k/Cn with ts tributary slots  |
+| ODU             | Optical Data Unit                                         |
+| ODUk/Cn         | Optical Data Unit-k/Cn                                    |
+| ODUk/Cn.ts      | Optical Data Unit k/Cn fitting in ts tributary slots      |
+| ODUk/CnP        | Optical Data Unit-k/Cn Path monitoring level              |
+| ODUk/CnT        | Optical Data Unit-k/Cn Tandem connection monitoring level |
+| OH              | Overhead                                                  |
+
+|         |                                                                                   |
+|---------|-----------------------------------------------------------------------------------|
+| OMFI    | OPU Multi-Frame Identifier                                                        |
+| OMS     | Optical Multiplex Section                                                         |
+| OMS-O   | Optical Multiplex Section Overhead                                                |
+| OMS-P   | Optical Multiplex Section Payload                                                 |
+| ONNI    | Optical Network Node Interface                                                    |
+| OPS     | Optical Physical Section                                                          |
+| OPSM    | Optical Physical Section Multilane                                                |
+| OPU     | Optical Payload Unit                                                              |
+| OPUk/Cn | Optical Payload Unit-k/Cn                                                         |
+| OSC     | Optical Supervisory Channel                                                       |
+| OSMC    | OTN synchronization messaging channel                                             |
+| OSME    | Optical Signal Maintenance Entity                                                 |
+| OTL     | Optical Transport Lane                                                            |
+| OTLk.n  | group of n Optical Transport Lanes that carry one OTUk                            |
+| OTLC.n  | group of n Optical Transport Lanes that carry one OTUC of an OTUCn                |
+| OTN     | Optical Transport Network                                                         |
+| OTS     | Optical Transmission Section                                                      |
+| OTS-O   | Optical Transmission Section Overhead                                             |
+| OTS-P   | Optical Transmission Section Payload                                              |
+| OTSi    | Optical Tributary Signal                                                          |
+| OTSiA   | Optical Tributary Signal Assembly                                                 |
+| OTSiG   | Optical Tributary Signal Group                                                    |
+| OTSiG-O | Optical Tributary Signal Group – Overhead                                         |
+| OTU     | Optical Transport Unit                                                            |
+| OTU0LL  | Completely standardized Optical Transport Unit-0 Low Latency                      |
+| OTU4-SC | Optical Transport Unit 4 with Stair Case FEC                                      |
+| OTUCn-M | Optical Transport Unit-Cn with n OxUC overhead instances and M 5G tributary slots |
+| OTUk/Cn | completely standardized Optical Transport Unit-k/Cn                               |
+| OTUkV   | functionally standardized Optical Transport Unit-k                                |
+| OTUk-v  | Optical Transport Unit-k with vendor specific OTU FEC                             |
+| PCC     | Protection Communication Channel                                                  |
+| P-CMEP  | Path-Connection Monitoring End Point                                              |
+| PCS     | Physical Coding Sublayer                                                          |
+| PJO     | Positive Justification Opportunity                                                |
+| PKT     | Packet                                                                            |
+| PLD     | Payload                                                                           |
+
+|         |                                                                |
+|---------|----------------------------------------------------------------|
+| PM      | Path Monitoring                                                |
+| PMA     | Physical Medium Attachment sublayer                            |
+| PMI     | Payload Missing Indication                                     |
+| PMOH    | Path Monitoring Overhead                                       |
+| PN      | Pseudo-random Number                                           |
+| POS     | Position field                                                 |
+| ppm     | parts per million                                              |
+| PRBS    | Pseudo Random Binary Sequence                                  |
+| PSI     | Payload Structure Identifier                                   |
+| PT      | Payload Type                                                   |
+| QDR     | Quad Data Rate                                                 |
+| RES     | Reserved for future international standardization              |
+| RF      | Remote Fault                                                   |
+| RS      | Reed-Solomon                                                   |
+| RS-Ack  | Re-sequence Acknowledge                                        |
+| SAPI    | Source Access Point Identifier                                 |
+| SBCON   | Single-Byte command code sets Connection                       |
+| SDI     | Serial Digital Interface                                       |
+| SDR     | Single Data Rate                                               |
+| Sk      | Sink                                                           |
+| SM      | Section Monitoring                                             |
+| SMOH    | Section Monitoring Overhead                                    |
+| SNC     | Subnetwork Connection                                          |
+| SNC/I   | Subnetwork Connection protection with Inherent monitoring      |
+| SNC/N   | Subnetwork Connection protection with Non-intrusive monitoring |
+| SNC/S   | Subnetwork Connection protection with Sublayer monitoring      |
+| So      | Source                                                         |
+| SSM     | Synchronization Status Message                                 |
+| TC      | Tandem Connection                                              |
+| TC-CMEP | Tandem Connection-Connection Monitoring End Point              |
+| TCM     | Tandem Connection Monitoring                                   |
+| TCMOH   | Tandem Connection Monitoring Overhead                          |
+| TS      | Tributary Slot                                                 |
+| TSI     | Transmitter Structure Identifier                               |
+| TSOH    | Tributary Slot Overhead                                        |
+| TTI     | Trail Trace Identifier                                         |
+| TTT     | Timing Transparent Transcoding                                 |
+
+|       |                                             |
+|-------|---------------------------------------------|
+| TxTI  | Transmitted Trace Identifier                |
+| UNI   | User-to-Network Interface                   |
+| XC    | Cross Connect                               |
+| XGPON | 10 Gigabit-capable Passive Optical Networks |
+
+# 5 Conventions
+
+This Recommendation uses the following conventions:
+
+- **k or Cn:** The index "k" is used to represent a supported bit rate and the different versions of OPUk, OPUCn, ODUk, ODUCn, OTUk and OTUCn. Examples for k are "1" for an approximate bit rate of 2.5 Gbit/s, "2" for an approximate bit rate of 10 Gbit/s, "3" for an approximate bit rate of 40 Gbit/s, and "4" for an approximate bit rate of 100 Gbit/s. When the "Cn" index is used the approximate bit rate is  $n \times 100$  Gbit/s. For example for Cn = C4 the approximate bit rate is 400 Gbit/s.
+- **x:** The index x gives the approximate bit rate for a CBR signal. It is used in the form "unit value, unit, [fractional unit value]". The currently defined unit value is "G" for Gbit/s. Examples for x are "40G" for 40 Gbit/s and "2G5" for 2.5 Gbit/s.
+- **-P:** The suffix -P is used to identify the payload element of the signal.
+- **-O:** The suffix -O is used to identify the non-associated overhead element of the signal.
+- **ODUj:** When two different ODUk information structures are involved, ODUj is used to denote the lower rate ODUk information structure (e.g., for ODUk multiplexing).
+
+The functional architecture of the optical transport network as specified in [ITU-T G.872] is used to derive the ONNI. The ONNI is specified in terms of the adapted and characteristic information present in each layer as described in [ITU-T G.805].
+
+**Transmission order:** The order of transmission of information in all the diagrams in this Recommendation is first from left to right and then from top to bottom. Within each byte the most significant bit is transmitted first. The most significant bit (bit 1) is illustrated at the left in all the diagrams.
+
+**Mapping order:** The serial bit stream of a constant bit rate signal is inserted into the OPU payload so that the bits will be transmitted on the OPU/ODU in the same order that they were received at the input of the AMP, BMP or GMP mapper function. If m bits  $b_a, b_b, b_c$  up to  $b_m$  are client signal bits of which  $b_a$  is the bit that is received first and  $b_m$  is the bit that is received last, then  $b_a$  will be mapped into bit 1 of a first OPU byte and  $b_m$  will be mapped into bit 8 of an  $n^{\text{th}}$  OPU byte (with  $n = m/8$ ).
+
+**Value of reserved bit(s):** The value of an overhead bit, which is reserved or reserved for future international standardization shall be set to "0".
+
+**Value of non-sourced bit(s):** Unless stated otherwise, any non-sourced bits shall be set to "0".
+
+**OTUk (k=1,2,3,4), OTUCn, OTU25, OTU50, ODUk (k=0,1,2,2e,3,4,flex,25,50), ODUCn, OPUk (k=0,1,2,2e,3,4,flex,25,50) and OPUCn overhead assignment:** The assignment of an overhead in the optical transport/data/payload unit signal to each part is defined in Figure 5-1. OTUk, OTU25, OTU50, ODUk, OPUk contain one instance of OTU, ODU, OPU overhead. OTUCn, ODUCn and OPUCn contain n instances of OTU, ODU, OPU overhead, numbered 1 to n.
+
+Interleaved versions of the OTU, ODU and OPU overhead may be present on OTUCn interfaces. This interleaving is interface specific and specified for OTN interfaces with standardized application codes in the interface specific Recommendations (ITU-T G.709.x series). Within the other clauses of this Recommendation an OTUCn, ODUCn and OPUCn are presented in an interface independent manner, by means of n OTUC, ODUC and OPUC instances that are marked #1 to #n.
+
+![Diagram of OTU, ODU and OPU overhead structure. The diagram shows a 4x16 grid. Row 1, columns 1-7: Frame alignment area; columns 8-14: OTU specific overhead area. Rows 2-4, columns 1-14: ODU specific overhead area. Columns 15-16, rows 1-4: OPU specific overhead area.](9c6461e1e94afae4dec455e69a2ce152_img.jpg)
+
+|       |                            |     |  |  |  |  |   |                            |     |  |  |  |  |    |                            |    |
+|-------|----------------------------|-----|--|--|--|--|---|----------------------------|-----|--|--|--|--|----|----------------------------|----|
+| Row # | Column #                   |     |  |  |  |  |   |                            |     |  |  |  |  |    |                            |    |
+|       | 1                          | ... |  |  |  |  | 7 | 8                          | ... |  |  |  |  | 14 | 15                         | 16 |
+| 1     | Frame alignment area       |     |  |  |  |  |   | OTU specific overhead area |     |  |  |  |  |    | OPU specific overhead area |    |
+| 2     | ODU specific overhead area |     |  |  |  |  |   |                            |     |  |  |  |  |    |                            |    |
+| 3     |                            |     |  |  |  |  |   |                            |     |  |  |  |  |    |                            |    |
+| 4     |                            |     |  |  |  |  |   |                            |     |  |  |  |  |    |                            |    |
+
+G.709-Y.1331(12)\_F5-1
+
+Diagram of OTU, ODU and OPU overhead structure. The diagram shows a 4x16 grid. Row 1, columns 1-7: Frame alignment area; columns 8-14: OTU specific overhead area. Rows 2-4, columns 1-14: ODU specific overhead area. Columns 15-16, rows 1-4: OPU specific overhead area.
+
+**Figure 5-1 – OTU, ODU and OPU overhead**
+
+# 6 Optical transport network interface structure
+
+The optical transport network as specified in [ITU-T G.872] provides for two OTN interface types: point-to-point interfaces and optical networking interfaces. Both OTN interface types consist of one or more optical tributary signals.
+
+The OTN point-to-point interfaces are defined with 3R processing at each end of the interface (terminating the optical tributary signals) and do not provide for optical layer overhead.
+
+The OTN optical networking interfaces are defined with optical layer overhead and may not provide for 3R processing at each end of the interface, which allow optical tributary signals to be forwarded beyond the interface.
+
+These two types of OTN interfaces consist of digital and management information defined in this Recommendation as carried by a physical interface, the specifications of which are outside the scope of this Recommendation.
+
+Each OTN interface may be associated with one or more application identifiers. Each application identifier represents either a standardized application code or a vendor specific identifier. An interface with one or more application codes may be used to interconnect (OTN) equipment from different vendors. An interface with one or more vendor specific identifiers is to be used to interconnect (OTN) equipment from the same vendor. When considering interconnection over an interface between user and provider administrations or provider to provider administrations, 3R termination shall be used on either side of the interface, unless mutually agreed otherwise.
+
+## 6.1 Basic signal structure
+
+The basic structure is shown in Figures 6-1 and 6-2 and consists of a digital and an optical structure.
+
+### 6.1.1 OTN digital structure
+
+The OTN digital structure (see Figure 6-1) is based on three classes of optical transport units (OTU); the OTUk, OTU25 and OTU50 and OTUCn.
+
+- The OTUk signal consists of a 4080 column by 4 row frame, which includes 256 columns allocated to contain a forward error correction code (FEC) and is operated at various bit rates that are represented by the value of k.
+- The OTU25 and OTU50 signals consist of a 3824 column by 4 row frame, which do not include a FEC area and are operated at 25 Gbit/s and 50 Gbit/s bit rates that are represented by the values 25 and 50. FEC for the OTU25 and OTU50 signals are interface specific and not included in the OTU25 and OTU50 definition.
+- The OTUCn signal consists of n interleaved 3824 columns by 4 row frames, which do not include a FEC area and is operated at n times a basic rate that is represented by OTUC. FEC for the OTUCn signal is interface specific and not included in the OTUCn definition.
+
+The OTUCn signal may be carried via a FlexO-x-<fec>-m interface group with  $m = \lceil n/x \rceil$  FlexO-x-<fec> interfaces; refer to [ITU-T G.709.1] and [ITU-T G.709.3].
+
+The OTU25 and OTU50 signals are carried via OTU25-RS and OTU50-RS interfaces; refer to [ITU-T G.709.4].
+
+The OTU contains an optical data unit (ODU), which contains an optical payload unit (OPU). The OTUk, OTU25, OTU50, OTUCn and ODUCn are digital section layers. The ODUk (and ODUj) is a path layer.
+
+The OTUk ( $k \in \{1,2,3,4,4\text{-SC}\text{\}}$ ) is fully standardized. There are two functionally standardized alternatives: OTUk-v and OTUkV. In all cases, these provide supervision and condition the signal for transport between 3R regeneration points in the OTN.
+
+The OTUCn, OTU25 and OTU50 provide supervision for transport between 3R regeneration points in the OTN. Note that the OTUCn, OTU25 and OTU50 do not condition the signal for transport between 3R regeneration points because encapsulation and forward error correction are not included in the OTUCn, OTU25 and OTU50 definition.
+
+The ODU provides:
+
+- Tandem connection monitoring (ODUjT, ODUkT, ODUCnT);
+- end-to-end section supervision (ODUjP, ODUkP, ODUCnP);
+- adaptation of client signals via the OPUk and OPUj ( $j \in \{0, 1, 2, 2e, 3, 4, \text{flex}\}$ ,  $k \in \{0, 1, 2, 2e, 3, 4, \text{flex}\}$ );
+- adaptation of client ODUj signals via the OPUk ( $j \in \{0, 1, 2, 2e, 3, 4, \text{flex}\}$ ,  $k \in \{1, 2, 3, 4, 25, 50\}$ , the bit rate of the ODUj is less than the OPUk payload bit rate);
+- adaptation of client ODUk signals via the OPUCn ( $k \in \{0, 1, 2, 2e, 3, 4, \text{flex}\}$ ).
+
+![Diagram of the digital structure of the OTN interfaces showing the mapping of client signals into OPUj/ODUj, then into OPUk/ODUk, and finally into various OTU types including OTU25, OTU50, OTUk, OTUkV, and OTUCn, leading to physical interfaces like OTU25-RS, OTU50-RS, and FlexO-x-<fec>-m.](2eb23c2210154279f8013a1594fbcc5a_img.jpg)
+
+|                                                               |          |                          |       |                                            |
+|---------------------------------------------------------------|----------|--------------------------|-------|--------------------------------------------|
+| Clients (e.g., STM-N, FC, IB, IP, Ethernet, FlexE, MPLS, ...) |          |                          |       |                                            |
+| OPUj                                                          |          |                          |       |                                            |
+| ODUj                                                          |          |                          |       |                                            |
+| OPUk                                                          |          |                          |       |                                            |
+| ODUk                                                          |          |                          |       |                                            |
+| $k = 25$                                                      | $k = 50$ | $k \in \{1, 2, 3, 4\}$   |       | $k \in \{0, 1, 2, 2e, 3, 4, \text{flex}\}$ |
+| OTU25                                                         | OTU50    | OTUk, OTU4-SC,<br>OTUk-v | OTUkV | OPUCn                                      |
+| OTU25-RS                                                      | OTU50-RS |                          |       | ODUCn                                      |
+|                                                               |          |                          |       | OTUCn                                      |
+|                                                               |          |                          |       | FlexO-x-<fec>-m                            |
+
+G.709-Y.1331(20)\_F6-1
+
+Diagram of the digital structure of the OTN interfaces showing the mapping of client signals into OPUj/ODUj, then into OPUk/ODUk, and finally into various OTU types including OTU25, OTU50, OTUk, OTUkV, and OTUCn, leading to physical interfaces like OTU25-RS, OTU50-RS, and FlexO-x--m.
+
+**Figure 6-1 – Digital structure of the OTN interfaces**
+
+### 6.1.2 OTN optical structure
+
+The OTN optical structure (see Figure 6-2) is based on the presence of one or more optical tributary signals combined with three classes of optical overhead deployment:
+
+- Absence of optical overhead in the case of OTN point-to-point interfaces.
+- Optical overhead carried in the same fibre as the one or more optical tributary signals in the case of OTN optical networking interfaces, type I.
+- Optical overhead carried via the overhead communication network (OCN) outside the fibre with one or more optical tributary signals in the case of OTN optical networking interfaces, type II.
+
+The optical overhead is divided into three digital layers that coincide with the maintenance entities defined in [ITU-T G.872], as shown in Figure 6-2:
+
+- Overhead to monitor the optical path maintenance entity (OCh-O and OTSiG-O), which extends between two OTSiG modulators and demodulators.
+- Overhead to monitor the optical multiplex section maintenance entity, which extends between two points of optical multiplexing (OMS-O).
+- Overhead to monitor the optical transmission section maintenance entity, which extends between two optical amplifiers, or between an optical multiplexer (without an amplifier) and the next optical amplifier (OTS-O).
+
+The OTN optical networking interfaces may support optical layer overhead (represented by the entities described above). Such overhead may be transported within the optical supervisory channel (OSC), the overhead communication channel (OCC) that is provided by the overhead communication network (OCN) (refer to [ITU-T G.7712]) or an alternative communication channel. Interfaces that support OCh-O and/or OTSiG-O support switching in the optical layer of the OCh and/or OTSiA signals which carry one optical transport unit or FlexO-x-<fec>-m group signal between 3R regeneration points. Interfaces that support OTS-O and OMS-O also support deployment of in-line optical amplifiers between optical layer switching points.
+
+The OTN point-to-point interfaces do not support optical layer overhead and are designed to transport the optical transport unit or FlexO-x-<fec>-m group signals over a single optical span with 3R regeneration points at each end. For such cases there is no optical path layer present in the interface stack.
+
+OTN point-to-point interfaces carry one or more OTUk or OTUCn or FlexO-x-<fec> of an OTUCn/FlexO-x-<fec>-m group, which are monitored by means of OTUk or OTUCn or FlexO-x-<fec>-m group overhead.
+
+OTN optical networking interfaces carry one or more optical tributary signals, each transporting an OTUk or an OTUCn or an OTUCn or one FlexO-x-<fec> out of an OTUCn/FlexO-x-<fec>-m group or a non-OTN client signal.
+
+![Diagram of OTN interface structures showing Client signals, OTN point-to-point interface, and OTN optical networking interfaces (type I and type II) with their respective overhead layers (OCh-O, OTSiG-O, OTSiG, OMS-O, OTS-O, OSC, OCC).](4cc7cdce3d498d8b0ba033a9be24ade5_img.jpg)
+
+The diagram illustrates the optical structure of OTN interfaces. At the top, a 'Client (e.g., OTUk, OTUk-v, OTUKV, OTUCn, FlexO-x-<fec>-m)' is shown with vertical lines representing multiple tributary signals. These signals enter a central 'Media' block. Above the Media block is the 'OTSiG' layer. To the left of the Media block is a stack of layers: 'OCh-O' and 'OTSiG-O' at the top, a dashed line, and 'OCC' at the bottom. To the right of the Media block is a stack of layers: 'OCh-O' and 'OTSiG-O' at the top, 'OMS-O', 'OTS-O', a dashed line, and 'OSC' at the bottom. Brackets at the bottom of the diagram define the interface types:
+ 
+
+- 'OTN point-to-point interface' is the bracket covering the Client signals and the Media block.
+- 'OTN optical networking interface, type I' is the bracket covering the Client signals, Media block, and the right-side layer stack (OCh-O, OTSiG-O, OMS-O, OTS-O, OSC).
+- 'OTN optical networking interface, type II' is the bracket covering the Client signals, Media block, and the left-side layer stack (OCh-O, OTSiG-O, OCC).
+
+ The reference 'G.709-Y.1331(20)\_F6-2' is located in the bottom right corner.
+
+Diagram of OTN interface structures showing Client signals, OTN point-to-point interface, and OTN optical networking interfaces (type I and type II) with their respective overhead layers (OCh-O, OTSiG-O, OTSiG, OMS-O, OTS-O, OSC, OCC).
+
+**Figure 6-2 – Optical structure of the OTN interfaces**
+
+## 6.2 Information structure for OTN interfaces
+
+The information structure for OTN interfaces is represented by information containment relationships and flows. The principal information containment relationships of the digital structure of the OTUk and OTUCn are described in Figures 6-3 and 6-4.
+
+For supervision purposes in OTN optical networking interfaces, the OTU signal is terminated whenever the OCh signal is terminated and the OTU signal may be terminated when the OTSiA signal
+
+is terminated. For supervision purposes in OTN point-to-point interfaces, the OTU signals are terminated whenever the interface signal is terminated.
+
+![Diagram of OTUk digital structure showing layers from Client down to Optical signal(s).](08a978a124d3ed6cf1a3d0cfd89418d0_img.jpg)
+
+This diagram illustrates the principal information containment relationship of the digital structure of OTUk. It shows a hierarchical stack of layers:
+
+- Client**: The top layer.
+- OPUk**: Contains **OPUk OH** and **OPUk payload**.
+- ODUk path**: Contains **ODUk PMOH** and **OPUk**.
+- ODUk tandem connection**: Contains **ODUk TCMOH**.
+- ODUk TC L1** and **ODUk TC Lm**: These are tandem connection monitoring points, each containing **ODUk TCMOH**. A bracket indicates "1 to 6 levels of ODUk tandem connection monitoring".
+- OTUk[-v,V] section**: Contains **OTUk[-v,V] OH** and **OTUk[-v,V] FEC**.
+- Optical signal(s)**: The bottom layer, labeled **OTSi(G)**.
+
+G.709-Y.1331(20)\_F6-3
+
+Diagram of OTUk digital structure showing layers from Client down to Optical signal(s).
+
+**Figure 6-3 – Principal information containment relationship of digital structure of OTUk**
+
+![Diagram of OTUCn digital structure showing layers from One or more clients down to Optical signal(s).](e180f2b5fcbe8001554a7c0677cd3f82_img.jpg)
+
+This diagram illustrates the principal information containment relationship of the digital structure of OTUCn. It shows a hierarchical stack of layers:
+
+- One or more clients**: The top layer.
+- OPUCn**: Contains **OPUCn OH** and **OPUCn payload**.
+- ODUCn multiplex section**: Contains **ODUCn PMOH** and **OPUCn**.
+- ODUCn tandem connection**: Contains **ODUCn TCMOH**.
+- ODUCn TC L1** and **ODUCn TC Lm**: These are tandem connection monitoring points, each containing **ODUCn TCMOH**. A bracket indicates "1 to 6 levels of ODUCn tandem connection monitoring".
+- OTUCn regenerator section**: Contains **OTUCn OH**.
+- FEC frame**: The layer below the regenerator section.
+- Optical signal(s)**: The bottom layer, labeled **OTSi(G)**.
+
+G.709-Y.1331(20)\_F6-4
+
+Diagram of OTUCn digital structure showing layers from One or more clients down to Optical signal(s).
+
+**Figure 6-4 – Principal information containment relationship of digital structure of OTUCn**
+
+# 7 Multiplexing/mapping principles and bit rates
+
+Figures 7-1A and 7-1B show the relationship between various information structure elements and illustrates the multiplexing structure and mappings for the OTU. In the multi-domain OTN any combination of the ODU multiplexing layers may be present at a given OTN NNI. The interconnection of and visibility of ODU multiplexing layers within an equipment or domain is outside the scope of this Recommendation. Figures 7-1A and 7-1B show that a (non-OTN) client signal is mapped into an OPU. This OPU signal is mapped into the associated ODU. This ODU signal is either mapped into the associated OTU[V] signal, or into an ODTU. This ODTU signal is multiplexed into an ODTU Group (ODTUG). The ODTUG signal is mapped into an OPU. This OPU signal is mapped into the associated ODU, etc.
+
+The OPU<sub>k</sub> (k=0,1,2,2e,3,4,flex,25,50) are the same information structures, but with different client signals. The OPUC<sub>n</sub> has a different information structure than the OPU<sub>k</sub>; the OPUC<sub>n</sub> information structure consists of n times the information structure of the OPU while the OPU<sub>k</sub> contain a single instance of the OPU information structure.
+
+![Figure 7-1A – OTN multiplexing and mapping structures. The diagram shows three horizontal flowcharts representing different OTN signal paths. Top path: OTUCn → ODUCn → OPUCn (two instances) → ODTUGn (PT=22) → ODTUCn.1, ODTUCn.2, ODTUCn.8, ODTUCn.20, ODTUCn.ts → ODU0, ODU1, ODU2, ODU2e, ODU3, ODUflex. Middle path: OTU50 → ODU50 → OPU50 (two instances) → ODTUG50 (PT=21) → ODTU50.1, ODTU50.2, ODTU50.8, ODTU50.31, ODTU50.ts → ODU0, ODU1, ODU2, ODU2e, ODU3, ODUflex. Bottom path: OTU25 → ODU25 → OPU25 (two instances) → ODTUG25 (PT=21) → ODTU25.1, ODTU25.2, ODTU25.8, ODTU25.ts → ODU0, ODU1, ODU2, ODU2e, ODUflex. Each path includes scaling factors (e.g., × 10n, × 40) and a note about Null PRBS and Proprietary use.](eb03559a4d92ea9ebd63ea9be663c50a_img.jpg)
+
+The diagram illustrates three OTN multiplexing and mapping structures:
+
+- Top structure (OTUCn):** OTUCn → ODUCn → OPUCn (× 1) → ODTUGn (PT = 22) → ODTUCn.1, ODTUCn.2, ODTUCn.8, ODTUCn.20, ODTUCn.ts → ODU0, ODU1, ODU2, ODU2e, ODU3, ODUflex. Scaling factors: × 10n, × 10n, × ⌊2.5n⌋, × n, × ⌊20n/ts⌋. Note: ≤ 10n (note).
+- Middle structure (OTU50):** OTU50 → ODU50 → OPU50 (× 1) → ODTUG50 (PT = 21) → ODTU50.1, ODTU50.2, ODTU50.8, ODTU50.31, ODTU50.ts → ODU0, ODU1, ODU2, ODU2e, ODU3, ODUflex. Scaling factors: × 40, × 20, × 5, × 1, × ⌊40/ts⌋.
+- Bottom structure (OTU25):** OTU25 → ODU25 → OPU25 (× 1) → ODTUG25 (PT = 21) → ODTU25.1, ODTU25.2, ODTU25.8, ODTU25.ts → ODU0, ODU1, ODU2, ODU2e, ODUflex. Scaling factors: × 20, × 10, × 2, × ⌊20/ts⌋.
+
+All structures include "Null PRBS" and "Proprietary use" options. The note "× MIN(⌊20n/ts⌋, 10n)" is present below the top structure.
+
+Figure 7-1A – OTN multiplexing and mapping structures. The diagram shows three horizontal flowcharts representing different OTN signal paths. Top path: OTUCn → ODUCn → OPUCn (two instances) → ODTUGn (PT=22) → ODTUCn.1, ODTUCn.2, ODTUCn.8, ODTUCn.20, ODTUCn.ts → ODU0, ODU1, ODU2, ODU2e, ODU3, ODUflex. Middle path: OTU50 → ODU50 → OPU50 (two instances) → ODTUG50 (PT=21) → ODTU50.1, ODTU50.2, ODTU50.8, ODTU50.31, ODTU50.ts → ODU0, ODU1, ODU2, ODU2e, ODU3, ODUflex. Bottom path: OTU25 → ODU25 → OPU25 (two instances) → ODTUG25 (PT=21) → ODTU25.1, ODTU25.2, ODTU25.8, ODTU25.ts → ODU0, ODU1, ODU2, ODU2e, ODUflex. Each path includes scaling factors (e.g., × 10n, × 40) and a note about Null PRBS and Proprietary use.
+
+G.709-Y.1331(20)\_F7-1A
+
+Figure 7-1A – OTN multiplexing and mapping structures
+
+![Figure 7-1B – OTN multiplexing and mapping structures. This diagram illustrates the hierarchical mapping of client signals into OTN frames. It shows four main paths: OTU4[V], OTU3[V], OTU2[V], and OTU1[V]. Each path consists of an OTU unit connected to multiple ODU units, which are then mapped into an OPU unit. The OPU units are then multiplexed into an ODTUG (Optical Data Tributary Unit Group) and finally into an OTU. The diagram includes various multiplexing factors (e.g., x 80, x 40, x 10, x 2, x [80/ts]) and PT (Payload Type) values (e.g., PT = 21, PT = 20). A legend at the bottom indicates that white boxes represent Multiplexing and grey boxes represent Mapping.](c5452f95f3b28f1bfe29e84fbc2e1267_img.jpg)
+
+Legend:  
+  Multiplexing     Mapping
+
+G.709-Y.1331(20)\_F7-1B
+
+Figure 7-1B – OTN multiplexing and mapping structures. This diagram illustrates the hierarchical mapping of client signals into OTN frames. It shows four main paths: OTU4[V], OTU3[V], OTU2[V], and OTU1[V]. Each path consists of an OTU unit connected to multiple ODU units, which are then mapped into an OPU unit. The OPU units are then multiplexed into an ODTUG (Optical Data Tributary Unit Group) and finally into an OTU. The diagram includes various multiplexing factors (e.g., x 80, x 40, x 10, x 2, x [80/ts]) and PT (Payload Type) values (e.g., PT = 21, PT = 20). A legend at the bottom indicates that white boxes represent Multiplexing and grey boxes represent Mapping.
+
+NOTE – Implementations should support the multiplexing of up to 10n ODU<sub>k</sub> (k=0,1,2,2e,3,4,flex) signals into an OPUC<sub>n</sub>.
+
+**Figure 7-1B – OTN multiplexing and mapping structures**
+
+## 7.1 Mapping
+
+The client signal or an optical data tributary unit group (ODTUG) is mapped into the OPU. The OPU is mapped into an ODU and the ODU is mapped into an OTU. The OTU is mapped into an OTSiG. The OTU<sub>k</sub> may also be mapped into an OTL<sub>k.n</sub> and an OTL<sub>k.n</sub> is then mapped into an OTSiG.
+
+## 7.2 Wavelength division multiplex
+
+Wavelength division multiplexing is used to multiplex the OTSi of one or more OTSiG for transport over an OTN interface.
+
+For the case of the OTN optical networking interfaces, type I, the OTSi of the OSC is multiplexed for transport over the interface using wavelength division multiplexing.
+
+## 7.3 Bit rates and capacity
+
+The bit rates and tolerance of the OTU signals are defined in Table 7-1.
+
+The bit rates and tolerance of the ODU signals are defined in clause 12.2 and Table 7-2.
+
+The bit rates and tolerance of the OPU payload are defined in Table 7-3.
+
+The OTU, ODU and OPU frame periods are defined in Table 7-4.
+
+The types and bit rates of the OTL signals are defined in Table 7-5.
+
+The 2.5G and 1.25G tributary slot related OPUk multiframe periods and 5G tributary slot OPUCn multiframe periods are defined in Table 7-6.
+
+The ODTU payload area bandwidths are defined in Table 7-7. The bandwidth depends on the OPU type and the mapping procedure (AMP or GMP). The AMP bandwidths include the bandwidth provided by the NJO overhead byte. GMP is defined without such NJO bytes.
+
+The bit rates and tolerance of the ODUflex(GFP,n,k) are defined in Table 7-8.
+
+The number of OPU tributary slots required by a client ODU are summarized in Table 7-9 and specified in clauses 19.6 and 20.5.
+
+**Table 7-1 – OTU types and bit rates**
+
+| OTU type | OTU nominal bit rate                          | OTU bit-rate tolerance   |
+|----------|-----------------------------------------------|--------------------------|
+| OTU1     | $255/238 \times 2\,488\,320$ kbit/s           | $\pm 20$ ppm<br>(Note 5) |
+| OTU2     | $255/237 \times 9\,953\,280$ kbit/s           |                          |
+| OTU3     | $255/236 \times 39\,813\,120$ kbit/s          |                          |
+| OTU4     | $255/227 \times 99\,532\,800$ kbit/s          |                          |
+| OTUCn    | $n \times 239/226 \times 99\,532\,800$ kbit/s |                          |
+| OTU25    | $61677/58112 \times 24\,883\,200$ kbit/s      |                          |
+| OTU50    | $61677/58112 \times 49\,766\,400$ kbit/s      |                          |
+
+NOTE 1 – The nominal OTU rates are approximately: 2 666 057.143 kbit/s (OTU1), 10 709 225.316 kbit/s (OTU2), 43 018 413.559 kbit/s (OTU3), 111 809 973.568 kbit/s (OTU4), 26 409 711.013 kbit/s (OTU25), 52 819 422.026 kbit/s (OTU50) and  $n \times 105\,258\,138.053$  kbit/s (OTUCn).
+
+NOTE 2 – OTU0, OTU2e and OTUflex are not specified in this Recommendation. ODU0 signals are to be transported over ODU1, ODU2, ODU3, ODU4, ODU25, ODU50 or ODUCn signals, ODU2e signals are to be transported over ODU3, ODU4, ODU25, ODU50 and ODUCn signals and ODUflex signals are transported over ODU2, ODU3, ODU4, ODU25, ODU50 and ODUCn signals.
+
+NOTE 3 – The OTUk (k=1,2,3,4) signal bit rates include the FEC overhead area. The OTUCn signal bit rates do not include a FEC overhead area.
+
+NOTE 4 – The OTU25 [OTU50] bit rate can be based on the OTU25-RS [OTU50-RS] bit rate as follows:  $514/544 \times 41118/41120 \times \text{OTU25-RS [OTU50-RS] bit rate} = 514/544 \times 41118/41120 \times 255/227 \times 24\,883\,200$  [49 766 400] kbit/s.
+
+NOTE 5 – Refer to clause 12.2.1.1 for the bit rate tolerance of synchronous OTUk (k=1,2,3,4), OTU25/50 and OTUCn.
+
+**Table 7-2 – ODU types and bit rates**
+
+| ODU type                                                                                                | ODU nominal bit rate                                                                                            | ODU bit-rate tolerance        |
+|---------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------|-------------------------------|
+| ODU0                                                                                                    | 1 244 160 kbit/s                                                                                                | $\pm 20$ ppm<br>(Note 4)      |
+| ODU1                                                                                                    | $239/238 \times 2\,488\,320$ kbit/s                                                                             |                               |
+| ODU2                                                                                                    | $239/237 \times 9\,953\,280$ kbit/s                                                                             |                               |
+| ODU3                                                                                                    | $239/236 \times 39\,813\,120$ kbit/s                                                                            |                               |
+| ODU4                                                                                                    | $239/227 \times 99\,532\,800$ kbit/s                                                                            |                               |
+| ODU25                                                                                                   | $61677/58112 \times 24\,883\,200$ kbit/s                                                                        |                               |
+| ODU50                                                                                                   | $61677/58112 \times 49\,766\,400$ kbit/s                                                                        |                               |
+| ODUCn                                                                                                   | $n \times 239/226 \times 99\,532\,800$ kbit/s                                                                   |                               |
+| ODU2e                                                                                                   | $239/237 \times 10\,312\,500$ kbit/s                                                                            | $\pm 100$ ppm                 |
+| ODUflex for CBR client signals                                                                          | $239/238 \times$ client signal bit rate                                                                         | $\pm 100$ ppm<br>(Notes 2, 3) |
+| ODUflex for GFP-F mapped client signals (ODUflex(GFP))                                                  | $239/238 \times$ OPUflex(GFP) payload signal rate                                                               | $\pm 100$ ppm                 |
+| ODUflex for GFP-F mapped client signals based on ODUk.ts and n 1.25G tributary slots (ODUflex(GFP,n,k)) | Configured bit rate (see Table 7-8)                                                                             |                               |
+| ODUflex for IMP mapped client signals (ODUflex(IMP))                                                    | $239/238 \times$ OPUflex(IMP) payload signal rate                                                               |                               |
+| ODUflex for IMP mapped FlexE Client signals (ODUflex(IMP,s))                                            | $s \times 239/238 \times 5\,156\,250$ kbit/s<br>$s = 2, 8, n \times 5$ with $n \geq 1$ (refer to clause 12.2.6) |                               |
+| ODUflex for FlexE-aware client signals                                                                  | $103\,125\,000 \times 240/238 \times n/20$ kbit/s<br>( $n = n_1 + n_2 + \dots + n_p$ )                          |                               |
+
+NOTE 1 – The nominal ODU rates are approximately: 2 498 775.126 kbit/s (ODU1), 10 037 273.924 kbit/s (ODU2), 40 319 218.983 kbit/s (ODU3), 104 794 445.815 kbit/s (ODU4), 26 409 711.013 kbit/s (ODU25), 52 819 422.026 kbit/s (ODU50), 10 399 525.316 kbit/s (ODU2e),  $n \times 105\,258\,138.053$  kbit/s (ODUCn).
+
+NOTE 2 – The bit-rate tolerance for ODUflex(CBR) signals is specified as  $\pm 100$  ppm. This value may be larger than the tolerance for the client signal itself (e.g.,  $\pm 20$  ppm). For such case, the tolerance is determined by the ODUflex(CBR) maintenance signals, which have a tolerance of  $\pm 100$  ppm.
+
+NOTE 3 – For ODUflex(CBR) signals with nominal bit rates close to the maximum ODTUk.ts payload bit rate and client rate tolerances less than  $\pm 100$  ppm (e.g.,  $\pm 10$  ppm), the ODUflex(CBR) maintenance signal bit rates may exceed the ODTUk.ts payload bit rate. For such cases either an additional tributary slot may be used (i.e., ODTUk.(ts+1)), or the nominal bit rate of the ODUflex(CBR) signal may be artificially reduced to a value of 100 ppm below the maximum ODUflex(CBR) signal bit rate.
+
+NOTE 4 – Refer to clause 12.2.1.1 for the bit rate tolerance of synchronous ODUk (k=1,2,3,4), ODU25/50 and ODUCn.
+
+**Table 7-3 – OPU types and bit rates**
+
+| <b>OPU type</b>                                                                                         | <b>OPU payload nominal bit rate</b>                                                       | <b>OPU payload bit-rate tolerance</b>                             |
+|---------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------|-------------------------------------------------------------------|
+| OPU0                                                                                                    | $238/239 \times 1\,244\,160$ kbit/s                                                       | $\pm 20$ ppm<br>(Note 2)                                          |
+| OPU1                                                                                                    | $2\,488\,320$ kbit/s                                                                      |                                                                   |
+| OPU2                                                                                                    | $238/237 \times 9\,953\,280$ kbit/s                                                       |                                                                   |
+| OPU3                                                                                                    | $238/236 \times 39\,813\,120$ kbit/s                                                      |                                                                   |
+| OPU4                                                                                                    | $238/227 \times 99\,532\,800$ kbit/s                                                      |                                                                   |
+| OPU25                                                                                                   | $7339563/6944384 \times 24\,883\,200$ kbit/s                                              |                                                                   |
+| OPU50                                                                                                   | $7339563/6944384 \times 49\,766\,400$ kbit/s                                              |                                                                   |
+| OPUCn                                                                                                   | $n \times 238/226 \times 99\,532\,800$ kbit/s                                             |                                                                   |
+| OPU2e                                                                                                   | $238/237 \times 10\,312\,500$ kbit/s                                                      | $\pm 100$ ppm                                                     |
+| OPUflex for CBR client signals                                                                          | client signal bit rate                                                                    | client signal bit-rate tolerance, with a maximum of $\pm 100$ ppm |
+| OPUflex for GFP-F mapped client signals (OPUflex(GFP))                                                  | Configured bit rate (refer to 12.2.5)                                                     | $\pm 100$ ppm                                                     |
+| OPUflex for GFP-F mapped client signals based on ODUk.ts and n 1.25G tributary slots (ODUflex(GFP,n,k)) | $238/239 \times \text{ODUflex(GFP,n,k) signal rate}$                                      |                                                                   |
+| OPUflex for IMP mapped client signals (OPUflex(IMP))                                                    | Configured bit rate (refer to clause 12.2.6)                                              |                                                                   |
+| OPUflex for IMP mapped FlexE Client signals OPUflex(IMP,s))                                             | $s \times 5\,156\,250$ kbit/s<br>$s = 2, 8, n \times 5$ with $n \geq 1$ (refer to 12.2.6) |                                                                   |
+| OPUflex for FlexE-aware client signals                                                                  | $103\,125\,000 \times 240/239 \times n/20$ kbit/s<br>( $n = n_1 + n_2 + \dots + n_p$ )    |                                                                   |
+
+NOTE 1 – The nominal OPU payload rates are approximately: 1 238 954.310 kbit/s (OPU0 Payload), 2 488 320.000 kbit/s (OPU1 Payload), 9 995 276.962 kbit/s (OPU2 Payload), 40 150 519.322 kbit/s (OPU3 Payload), 104 355 975.330 (OPU4 Payload), 26 299 210.130 kbit/s (OPU25 Payload), 52 598 420.261 kbit/s (OPU50 Payload), 10 356 012.658 kbit/s (OPU2e Payload),  $n \times 104\,817\,727.434$  kbit/s (OPUCn Payload).  
+NOTE 2 – Refer to clause 12.2.1.1 for the bit rate tolerance of synchronous OxUk ( $k=1,2,3,4$ ), OxU25/50 and OxUCn.
+
+**Table 7-4 – OTU/ODU/OPU frame periods**
+
+| <b>OTU/ODU/OPU type</b> | <b>Period (Note)</b>                                                                                                                                                                                                                                                |
+|-------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| ODU0/OPU0               | 98.354 µs                                                                                                                                                                                                                                                           |
+| OTU1/ODU1/OPU1          | 48.971 µs                                                                                                                                                                                                                                                           |
+| OTU2/ODU2/OPU2          | 12.191 µs                                                                                                                                                                                                                                                           |
+| OTU3/ODU3/OPU3          | 3.035 µs                                                                                                                                                                                                                                                            |
+| OTU4/ODU4/OPU4          | 1.168 µs                                                                                                                                                                                                                                                            |
+| OTU25/ODU25/OPU25       | 4.633 µs                                                                                                                                                                                                                                                            |
+| OTU50/ODU50/OPU50       | 2.317 µs                                                                                                                                                                                                                                                            |
+| ODU2e/OPU2e             | 11.767 µs                                                                                                                                                                                                                                                           |
+| OTUCn/ODUCn/OPUCn       | 1.163 µs                                                                                                                                                                                                                                                            |
+| ODUflex/OPUflex         | CBR client signals: $121856/\text{client\_signal\_bit\_rate}$<br>GFP-F mapped client signals: $122368/\text{ODUflex\_bit\_rate}$<br>IMP mapped client signals: $122368/\text{ODUflex\_bit\_rate}$<br>FlexE-aware client signals: $122368/\text{ODUflex\_bit\_rate}$ |
+
+NOTE – The period is an approximated value, rounded to 3 decimal places.
+
+**Table 7-5 – OTL types and bit rates**
+
+| <b>OTL type</b> | <b>OTL nominal bit rate</b>                     | <b>OTL bit-rate tolerance</b> |
+|-----------------|-------------------------------------------------|-------------------------------|
+| OTL3.4          | 4 lanes of $255/236 \times 9\,953\,280$ kbit/s  | ±20 ppm                       |
+| OTL4.4          | 4 lanes of $255/227 \times 24\,883\,200$ kbit/s |                               |
+
+NOTE – The nominal OTL rates are approximately: 10 754 603.390 kbit/s (OTL3.4) and 27 952 493.392 kbit/s (OTL4.4).
+
+**Table 7-6 – OPUk multiframe periods for 2.5G and 1.25G tributary slots and ODUCn multiframe periods for 5G tributary slots**
+
+| <b>OPU type</b> | <b>1.25G tributary slot multiframe period (Note)</b> | <b>2.5G tributary slot multiframe period (Note)</b> | <b>5G tributary slot multiframe period (Note)</b> |
+|-----------------|------------------------------------------------------|-----------------------------------------------------|---------------------------------------------------|
+| OPU1            | 97.942 µs                                            | –                                                   | –                                                 |
+| OPU2            | 97.531 µs                                            | 48.765 µs                                           | –                                                 |
+| OPU3            | 97.119 µs                                            | 48.560 µs                                           | –                                                 |
+| OPU4            | 93.416 µs                                            | –                                                   | –                                                 |
+| OPU25           | 92.669 µs                                            | –                                                   | –                                                 |
+| OPU50           | 92.669 µs                                            | –                                                   | –                                                 |
+| OPUCn           | –                                                    | –                                                   | 23.251 µs                                         |
+
+NOTE – The period is an approximated value, rounded to 3 decimal places.
+
+**Table 7-7 – ODTU payload bandwidth (kbit/s)**
+
+| ODTU type                       | ODTU payload nominal bandwidth                               |                                    | ODTU payload bit-rate tolerance    |  |
+|---------------------------------|--------------------------------------------------------------|------------------------------------|------------------------------------|--|
+|                                 | Minimum                                                      | Nominal                            |                                    |  |
+| <b>ODTU01</b>                   | $(1904 + 1/8)/3824 \times \text{ODU1 bit rate}$              |                                    | $\pm 20 \text{ ppm}$               |  |
+| <b>ODTU12</b>                   | $(952 + 1/16)/3824 \times \text{ODU2 bit rate}$              |                                    |                                    |  |
+| <b>ODTU13</b>                   | $(238 + 1/64)/3824 \times \text{ODU3 bit rate}$              |                                    |                                    |  |
+| <b>ODTU23</b>                   | $(952 + 4/64)/3824 \times \text{ODU3 bit rate}$              |                                    |                                    |  |
+| <b>ODTU2.ts</b>                 | $\text{ts} \times 476/3824 \times \text{ODU2 bit rate}$      |                                    |                                    |  |
+| <b>ODTU3.ts</b>                 | $\text{ts} \times 119/3824 \times \text{ODU3 bit rate}$      |                                    |                                    |  |
+| <b>ODTU4.ts</b>                 | $\text{ts} \times 47.5/3824 \times \text{ODU4 bit rate}$     |                                    |                                    |  |
+| <b>ODTU25.ts</b>                | $\text{ts} \times 190.4/3824 \times \text{ODU25 bit rate}$   |                                    |                                    |  |
+| <b>ODTU50.ts</b>                | $\text{ts} \times 95.2/3824 \times \text{ODU50 bit rate}$    |                                    |                                    |  |
+| <b>ODTUCn.ts</b>                | $\text{ts} \times 190.4/3824 \times \text{ODUCn bit rate}/n$ |                                    |                                    |  |
+|                                 | Minimum                                                      | Nominal                            | Maximum                            |  |
+| <b>ODTU01</b>                   | 1 244 216.796                                                | 1 244 241.681                      | 1 244 266.566                      |  |
+| <b>ODTU12</b>                   | 2 498 933.311                                                | 2 498 983.291                      | 2 499 033.271                      |  |
+| <b>ODTU13</b>                   | 2 509 522.012                                                | 2 509 572.203                      | 2 509 622.395                      |  |
+| <b>ODTU23</b>                   | 10 038 088.048                                               | 10 038 288.814                     | 10 038 489.579                     |  |
+| <b>ODTU2.ts</b>                 | $\text{ts} \times 1\,249\,384.632$                           | $\text{ts} \times 1\,249\,409.620$ | $\text{ts} \times 1\,249\,434.608$ |  |
+| <b>ODTU3.ts</b>                 | $\text{ts} \times 1\,254\,678.635$                           | $\text{ts} \times 1\,254\,703.729$ | $\text{ts} \times 1\,254\,728.823$ |  |
+| <b>ODTU4.ts</b>                 | $\text{ts} \times 1\,301\,683.217$                           | $\text{ts} \times 1\,301\,709.251$ | $\text{ts} \times 1\,301\,735.285$ |  |
+| <b>ODTU25.ts,<br/>ODTU50.ts</b> | $\text{ts} \times 1\,314\,934.207$                           | $\text{ts} \times 1\,314\,960.507$ | $\text{ts} \times 1\,314\,986.806$ |  |
+| <b>ODTUCn.ts</b>                | $\text{ts} \times 5\,240\,781.554$                           | $\text{ts} \times 5\,240\,886.372$ | $\text{ts} \times 5\,240\,991.189$ |  |
+
+NOTE – The bandwidth is an approximated value, rounded to 3 decimal places.
+
+**Table 7-8 – Recommended ODUflex (GFP,n,k) bit rates and tolerance**
+
+| ODU type                                                                  | Nominal bit-rate          | Tolerance             |
+|---------------------------------------------------------------------------|---------------------------|-----------------------|
+| ODU2.ts (Note 1)                                                          | 1'249'177.230 kbit/s      |                       |
+| ODU3.ts (Note 1)                                                          | 1'254'470.354 kbit/s      |                       |
+| ODU4.ts (Note 1)                                                          | 1'301'467.133 kbit/s      |                       |
+| ODUflex(GFP,n,2) of n 1.25G tributary slots, $1 \leq n \leq 8$            | $n \times \text{ODU2.ts}$ | $\pm 100 \text{ ppm}$ |
+| ODUflex(GFP,n,3) of n 1.25G tributary slots, $9 \leq n \leq 32$ (Note 3)  | $n \times \text{ODU3.ts}$ | $\pm 100 \text{ ppm}$ |
+| ODUflex(GFP,n,4) of n 1.25G tributary slots, $33 \leq n \leq 80$ (Note 2) | $n \times \text{ODU4.ts}$ | $\pm 100 \text{ ppm}$ |
+
+NOTE 1 – The values of ODUk.ts are chosen to permit a variety of methods to be used to generate an ODUflex(GFP) clock. See Appendix XI for the derivation of these values and example ODUflex(GFP) clock generation methods.
+
+NOTE 2 – Transport of packet clients via an ODUflex(GFP) is specified up to 100 Gbit/s.
+
+NOTE 3 – The value of n may be larger than 8 for the case where an ODU25u or ODU50u is used as server. Refer to Annex L.
+
+**Table 7-9 – Number of tributary slots required for ODUj into OPUk  
+and for ODUk into OPUCn**
+
+|                                        | # 5G TS<br>OPUCn | # 2.5G<br>tributary slots |      | # 1.25G<br>tributary slots |      |      |      |       |       |
+|----------------------------------------|------------------|---------------------------|------|----------------------------|------|------|------|-------|-------|
+|                                        |                  | OPU2                      | OPU3 | OPU1                       | OPU2 | OPU3 | OPU4 | OPU25 | OPU50 |
+| ODU0                                   | 1                | –                         | –    | 1                          | 1    | 1    | 1    | 1     | 1     |
+| ODU1                                   | 1                | 1                         | 1    | –                          | 2    | 2    | 2    | 2     | 2     |
+| ODU2                                   | 2                | –                         | 4    | –                          | –    | 8    | 8    | 8     | 8     |
+| ODU2e                                  | 2                | –                         | –    | –                          | –    | 9    | 8    | 8     | 8     |
+| ODU3                                   | 8                | –                         | –    | –                          | –    | –    | 31   | –     | 31    |
+| ODU4                                   | 20               | –                         | –    | –                          | –    | –    | –    | –     | –     |
+| ODUflex(CBR)                           |                  |                           |      |                            |      |      |      |       |       |
+| – ODUflex(IB SDR)                      | 1                | –                         | –    | –                          | 3    | 3    | 2    | 2     | 2     |
+| – ODUflex(IB DDR)                      | 1                | –                         | –    | –                          | 5    | 5    | 4    | 4     | 4     |
+| – ODUflex(IB QDR)                      | 2                | –                         | –    | –                          | –    | 9    | 8    | 8     | 8     |
+| – ODUflex(FC-400)                      | 1                | –                         | –    | –                          | 4    | 4    | 4    | 4     | 4     |
+| – ODUflex(FC-800)                      | 2                | –                         | –    | –                          | 7    | 7    | 7    | 7     | 7     |
+| – ODUflex(FC-1600)                     | 3                | –                         | –    | –                          | –    | 12   | 11   | 11    | 11    |
+| – ODUflex(FC-3200)                     | 6                | –                         | –    | –                          | –    | 23   | 22   | –     | 22    |
+| – ODUflex(3G SDI)<br>(2 970 000)       | 1                | –                         | –    | –                          | 3    | 3    | 3    | 3     | 3     |
+| – ODUflex(3G SDI)<br>(2 970 000/1.001) | 1                | –                         | –    | –                          | 3    | 3    | 3    | 3     | 3     |
+| – ODUflex(25GBase-R)                   | 5                | –                         | –    | –                          | –    | 21   | 20   | 20    | 20    |
+| – ODUflex(50GBase-R)                   | 10               | –                         | –    | –                          | –    | –    | 40   | –     | 40    |
+| – ODUflex(200GBase-R)                  | 40               | –                         | –    | –                          | –    | –    | –    | –     | –     |
+| – ODUflex(400GBase-R)                  | 80               | –                         | –    | –                          | –    | –    | –    | –     | –     |
+| ODUflex(GFP)                           | Note             | –                         | –    | –                          | Note | Note | Note | Note  | Note  |
+| – ODUflex(GFP,n,k)                     | Note             | –                         | –    | –                          | n    | n    | n    | n     | n     |
+| ODUflex(IMP)                           | Note             | –                         | –    | –                          | Note | Note | Note | Note  | Note  |
+| – ODUflex(IMP,s)                       | Note             | –                         | –    | –                          | –    | Note | Note | Note  | Note  |
+| ODUflex(FlexE)                         | Note             | –                         | –    | –                          | –    | Note | Note | Note  | Note  |
+
+NOTE – Refer to equations 19-1a, 19-1b, 20-1a and 20-1b in clauses 19.6 and 20.5.
+
+## 7.4 ODUk time-division multiplex
+
+Figure 7-1 shows the relationship between various time-division multiplexing elements that are defined below and illustrates possible multiplexing structures. Table 7-10 provides an overview of valid tributary slot types and mapping procedure configuration options.
+
+Up to 2 ODU0 signals are multiplexed into an ODTUG1 (PT=20) using time-division multiplexing. The ODTUG1 (PT=20) is mapped into the OPU1.
+
+Up to 4 ODU1 signals are multiplexed into an ODTUG2 (PT=20) using time-division multiplexing. The ODTUG2 (PT=20) is mapped into the OPU2.
+
+A mixture of p ( $p \leq 4$ ) ODU2 and q ( $q \leq 16$ ) ODU1 signals can be multiplexed into an ODTUG3 (PT=20) using time-division multiplexing. The ODTUG3 (PT=20) is mapped into the OPU3.
+
+A mixture of p ( $p \leq 8$ ) ODU0, q ( $q \leq 4$ ) ODU1, r ( $r \leq 8$ ) ODUflex signals can be multiplexed into an ODTUG2 (PT=21) using time-division multiplexing. The ODTUG2 (PT=21) is mapped into the OPU2.
+
+A mixture of  $p$  ( $p \leq 32$ ) ODU0,  $q$  ( $q \leq 16$ ) ODU1,  $r$  ( $r \leq 4$ ) ODU2,  $s$  ( $s \leq 3$ ) ODU2e and  $t$  ( $t \leq 32$ ) ODUflex signals can be multiplexed into an ODTUG3 (PT=21) using time-division multiplexing. The ODTUG3 (PT=21) is mapped into the OPU3.
+
+A mixture of  $p$  ( $p \leq 80$ ) ODU0,  $q$  ( $q \leq 40$ ) ODU1,  $r$  ( $r \leq 10$ ) ODU2,  $s$  ( $s \leq 10$ ) ODU2e,  $t$  ( $t \leq 2$ ) ODU3 and  $u$  ( $u \leq 80$ ) ODUflex signals can be multiplexed into an ODTUG4 (PT=21) using time-division multiplexing. The ODTUG4 (PT=21) is mapped into the OPU4.
+
+NOTE 1 – The ODTUGk is a logical construct and is not defined further. ODTUjk and ODTUk.ts signals are directly time-division multiplexed into the tributary slots of an OPUk.
+
+A mixture of  $p$  ( $p \leq 20$ ) ODU0,  $q$  ( $q \leq 10$ ) ODU1,  $r$  ( $r \leq 2$ ) ODU2,  $s$  ( $s \leq 2$ ) ODU2e and  $u$  ( $u \leq 20$ ) ODUflex signals can be multiplexed into an ODTUG25 (PT=21) using time-division multiplexing. The ODTUG25 (PT=21) is mapped into the OPU25.
+
+A mixture of  $p$  ( $p \leq 40$ ) ODU0,  $q$  ( $q \leq 20$ ) ODU1,  $r$  ( $r \leq 5$ ) ODU2,  $s$  ( $s \leq 5$ ) ODU2e,  $t$  ( $t \leq 1$ ) ODU3 and  $u$  ( $u \leq 40$ ) ODUflex signals can be multiplexed into an ODTUG50 (PT=21) using time-division multiplexing. The ODTUG50 (PT=21) is mapped into the OPU50.
+
+A mixture of  $p$  ( $p \leq 10n$ ) ODU0,  $q$  ( $q \leq 10n$ ) ODU1,  $r$  ( $r \leq 10n$ ) ODU2,  $s$  ( $s \leq 10n$ ) ODU2e,  $t$  ( $t \leq \text{int}(10n/4)$ ) ODU3,  $u$  ( $u \leq n$ ) ODU4 and  $v$  ( $v \leq 10n$ ) ODUflex signals can be multiplexed into an ODTUGCn (PT=22) using time-division multiplexing. The ODTUGCn (PT=22) is mapped into the OPUCn.
+
+NOTE 2 – The ODTUGk and ODTUGCn are logical constructs and are not defined further. ODTUjk and ODTUk.ts signals are directly time-division multiplexed into the tributary slots of an OPUk. ODTUCn.ts signals are directly time-division multiplexed into the tributary slots of an OPUCn.
+
+NOTE 3 – Implementations should support the multiplexing of up to  $10n$  ODUk ( $k=0,1,2,2e,3,4,flex$ ) signals into an OPUCn. Support for the multiplexing of up to  $20n$  ODUk ( $k=0,1,flex$ ) signals into the OPUCn is not required.
+
+**Table 7-10 – Overview of ODUj into OPUk and ODUk into OPUCn mapping types**
+
+|         | 5G tributary slots | 2.5G tributary slots |                 | 1.25G tributary slots |                 |                 |                 |                  |                  |
+|---------|--------------------|----------------------|-----------------|-----------------------|-----------------|-----------------|-----------------|------------------|------------------|
+|         | OPUCn<br>(PT=22)   | OPU2<br>(PT=20)      | OPU3<br>(PT=20) | OPU1<br>(PT=20)       | OPU2<br>(PT=21) | OPU3<br>(PT=21) | OPU4<br>(PT=21) | OPU25<br>(PT=21) | OPU50<br>(PT=21) |
+| ODU0    | GMP – Note         | –                    | –               | AMP                   | GMP             | GMP             | GMP             | GMP              | GMP              |
+| ODU1    | GMP – Note         | AMP                  | AMP             | –                     | AMP             | AMP             | GMP             | GMP              | GMP              |
+| ODU2    | GMP                | –                    | AMP             | –                     | –               | AMP             | GMP             | GMP              | GMP              |
+| ODU2e   | GMP                | –                    | –               | –                     | –               | GMP             | GMP             | GMP              | GMP              |
+| ODU3    | GMP                | –                    | –               | –                     | –               | –               | GMP             | –                | GMP              |
+| ODU4    | GMP                | –                    | –               | –                     | –               | –               | –               | –                | –                |
+| ODUflex | GMP                | –                    | –               | –                     | GMP             | GMP             | GMP             | GMP              | GMP              |
+
+NOTE – Mapping ODU0 and ODU1 into a 5G tributary slot of the OPUCn does not fully occupy the tributary slot's bandwidth.
+
+Figures 7-2, 7-3 and 7-4 show how various signals are multiplexed using the ODTUG1/2/3 (PT=20) multiplexing elements. Figure 7-2 presents the multiplexing of four ODU1 signals into the OPU2 signal via the ODTUG2 (PT=20). An ODU1 signal is extended with a frame alignment overhead and asynchronously mapped into the optical data tributary unit 1 into 2 (ODTU12) using the AMP justification overhead (JOH). The four ODTU12 signals are time-division multiplexed into the optical data tributary unit group 2 (ODTUG2) with payload type 20, after which this signal is mapped into the OPU2.
+
+![Diagram of ODU1 into ODU2 multiplexing method via ODTUG2 (PT=20).](692541e65db4dc852988ce77ebb60ce5_img.jpg)
+
+This diagram shows the hierarchical mapping of ODU1 into ODU2. At the top level, an ODU1 frame (comprising ODU1 OH and ODU1 payload) is mapped into an ODTU12 structure. The ODTU12 includes an ODTU12 JOH (Justification Overhead) and the ODU1 data. Multiple such ODTU12 units (each with its own JOH) are then multiplexed into an ODTUG2 (Optical Data Tributary Unit Group 2). The ODTUG2 is then mapped into the OPU2 payload area. The OPU2 frame (with OPU2 OH) is finally encapsulated into an ODU2 frame (with ODU2 OH and ODU2 payload). The diagram is referenced as G.709-Y.1331(12)\_F7-2.
+
+Diagram of ODU1 into ODU2 multiplexing method via ODTUG2 (PT=20).
+
+**Figure 7-2 – ODU1 into ODU2 multiplexing method via ODTUG2 (PT=20)**
+
+Figure 7-3 presents the multiplexing of up to 16 ODU1 signals and/or up to 4 ODU2 signals into the OPU3 signal via the ODTUG3 (PT=20). An ODU1 signal is extended with a frame alignment overhead and asynchronously mapped into the optical data tributary unit 1 into 3 (ODTU13) using the AMP justification overhead (JOH). An ODU2 signal is extended with a frame alignment overhead and asynchronously mapped into the optical data tributary unit 2 into 3 (ODTU23) using the AMP justification overhead (JOH). "x" ODTU23 ( $0 \leq x \leq 4$ ) signals and "16-4x" ODTU13 signals are time-division multiplexed into the optical data tributary unit group 3 (ODTUG3) with payload type 20, after which this signal is mapped into the OPU3.
+
+![Diagram of ODU1 and ODU2 into ODU3 multiplexing method via ODTUG3 (PT=20).](e05b36c0d46549e681ce6581422c66b2_img.jpg)
+
+This diagram illustrates the flexible multiplexing of ODU1 and ODU2 signals into an ODU3. On the left, an ODU2 frame (OH and payload) is mapped into an ODTU23 with its own JOH. On the right, an ODU1 frame (OH and payload) is mapped into an ODTU13 with its own JOH. These different tributary units (ODTU23s and ODTU13s) are multiplexed together into a single ODTUG3 structure. The ODTUG3 is then mapped into the OPU3 payload. The OPU3 frame (with OPU3 OH) is then encapsulated into the final ODU3 frame (with ODU3 OH and ODU3 payload). The diagram is referenced as G.709-Y.1331(12)\_F7-3.
+
+Diagram of ODU1 and ODU2 into ODU3 multiplexing method via ODTUG3 (PT=20).
+
+**Figure 7-3 – ODU1 and ODU2 into ODU3 multiplexing method via ODTUG3 (PT=20)**
+
+Figure 7-4 presents the multiplexing of two ODU0 signals into the OPU1 signal via the ODTUG1 (PT=20). An ODU0 signal is extended with a frame alignment overhead and asynchronously mapped into the optical data tributary unit 0 into 1 (ODTU01) using the AMP justification overhead (JOH). The two ODTU01 signals are time-division multiplexed into the optical data tributary unit group 1 (ODTUG1) with payload type 20, after which this signal is mapped into the OPU1.
+
+![Diagram illustrating the multiplexing of two ODU0 signals into the OPU1 signal via the ODTUG1 (PT=20).](c76da2d73c064464051d1583fd80bb6b_img.jpg)
+
+The diagram illustrates the hierarchical multiplexing process. At the top, an ODU0 signal is shown with its 'ODU0 OH' and 'ODU0 payload'. This is mapped into an ODTU01 signal, which adds an 'ODTU01 JOH'. Two such ODTU01 signals are then time-division multiplexed into an ODTUG1 (PT = 20) signal. This ODTUG1 signal is then mapped into an OPU1 signal, which adds an 'OPU1 OH' and carries the 'OPU1 payload'. Finally, the OPU1 signal is shown as part of an ODU1 signal, which adds an 'ODU1 OH' and carries the 'ODU1 payload'.
+
+Diagram illustrating the multiplexing of two ODU0 signals into the OPU1 signal via the ODTUG1 (PT=20).
+
+G.709-Y.1331(12)\_F7-4
+
+**Figure 7-4 – ODU0 into ODU1 multiplexing method via ODTUG1 (PT=20)**
+
+Figures 7-5, 7-6 and 7-7 show how various signals are multiplexed using the ODTUG2/3/4 (PT=21) multiplexing elements.
+
+Figure 7-5 presents the multiplexing of up to eight ODU0 signals, and/or up to four ODU1 signals and/or up to eight ODUflex signals into the OPU2 signal via the ODTUG2 (PT=21). An ODU1 signal is extended with a frame alignment overhead and asynchronously mapped into the optical data tributary unit 1 into 2 (ODTU12) using the AMP justification overhead (JOH). An ODU0 signal is extended with a frame alignment overhead and asynchronously mapped into the optical data tributary unit 2.1 (ODTU2.1) using the GMP justification overhead. An ODUflex signal is extended with a frame alignment overhead and asynchronously mapped into the optical data tributary unit 2.ts (ODTU2.ts) using the GMP justification overhead. Up to eight ODTU2.1 signals, up to four ODTU12 signals and up to eight ODTU2.ts signals are time-division multiplexed into the optical data tributary unit group 2 (ODTUG2) with payload type 21, after which this signal is mapped into the OPU2.
+
+![Diagram illustrating the multiplexing method for ODU0, ODU1, and ODUflex into ODU2 via ODTUG2 (PT=21).](7ae836e598020d937ed1478c2ef13025_img.jpg)
+
+The diagram illustrates the hierarchical structure of optical transport network (OTN) multiplexing. At the top, three input paths are shown:
+
+- ODU Path:** An ODU (consisting of ODU OH and ODU payload) is mapped into an ODTU2.ts (ODUflex) container, which is then processed by an ODTU2.ts JOH block.
+- ODU0 Path:** An ODU0 (consisting of ODU0 OH and ODU0 payload) is mapped into an ODTU2.1 container, which is then processed by an ODTU2.1 JOH block.
+- ODU1 Path:** An ODU1 (consisting of ODU1 OH and ODU1 payload) is mapped into an ODTU12 container, which is then processed by an ODTU12 JOH block.
+
+These JOH blocks feed into a common ODTUG2 (PT = 21) multiplexer. The multiplexer outputs a stream of ODTUG2 (PT = 21) containers, which are then mapped into an OPU2 payload. The OPU2 payload is further encapsulated into an ODU2 container (consisting of ODU2 OH and ODU2 payload).
+
+The diagram also shows the internal structure of the ODTUG2 (PT = 21) multiplexer, which consists of multiple ODTU2.ts JOH, ODTU2.1 JOH, and ODTU12 JOH blocks, along with ODUflex, ODU0, and ODU1 containers, all connected to the ODTUG2 (PT = 21) output.
+
+Diagram illustrating the multiplexing method for ODU0, ODU1, and ODUflex into ODU2 via ODTUG2 (PT=21).
+
+G.709-Y.1331(12)\_F7-5
+
+Figure 7-5 – ODU0, ODU1 and ODUflex into ODU2 multiplexing method via ODTUG2 (PT=21)
+
+Figure 7-6 presents the multiplexing of up to thirty-two ODU0 signals and/or up to sixteen ODU1 signals and/or up to four ODU2 signals and/or up to three ODU2e signals and/or up to thirty-two ODUFlex signals into the OPU3 signal via the ODTUG3 (PT=21). An ODU1 signal is extended with a frame alignment overhead and asynchronously mapped into the optical data tributary unit 1 into 3 (ODTU13) using the AMP justification overhead (JOH). An ODU2 signal is extended with a frame alignment overhead and asynchronously mapped into the optical data tributary unit 2 into 3 (ODTU23) using the AMP justification overhead. An ODU0 signal is extended with a frame alignment overhead and asynchronously mapped into the optical data tributary unit 3.1 (ODTU3.1) using the GMP justification overhead. An ODU2e signal is extended with a frame alignment overhead and asynchronously mapped into the optical data tributary unit 3.9 (ODTU3.9) using the GMP justification overhead. An ODUFlex signal is extended with a frame alignment overhead and asynchronously mapped into the optical data tributary unit 3.ts (ODTU3.ts) using the GMP justification overhead. Up to thirty-two ODTU3.1 signals, up to sixteen ODTU13 signals, up to four ODTU23 signals, up to three ODTU3.9 and up to thirty-two ODTU3.ts signals are time-division multiplexed into the optical data tributary unit group 3 (ODTUG3) with payload type 21, after which this signal is mapped into the OPU3.
+
+![Diagram showing the multiplexing of ODU0, ODU1, ODU2, ODU2e, and ODUflex into ODU3 via ODTUG3 (PT=21).](e451401f8fa77b466f401d5fce15b26c_img.jpg)
+
+The diagram illustrates the hierarchical multiplexing of various Optical Data Unit (ODU) types into a single ODU3 frame. At the top, three input ODU types are shown: ODU, ODU2, and ODU1. Each is represented by a box containing 'OH' (Overhead) and 'payload'.
+
+- The **ODU** (containing ODU0, ODU2e, or ODUflex) is first encapsulated into an **ODTU3.ts** container. This container then passes through an **ODTU3.ts JOH** (Joint Overhead) block.
+- The **ODU2** is encapsulated into an **ODTU23** container, which passes through an **ODTU23 JOH** block.
+- The **ODU1** is encapsulated into an **ODTU13** container, which passes through an **ODTU13 JOH** block.
+
+These three streams are then multiplexed together into a larger container labeled **ODTUG3 (PT = 21)**. This container is further encapsulated into an **OPU3** (Optical Payload Unit) frame, which consists of an **OPU3 OH** and an **OPU3 payload**. Finally, the OPU3 frame is encapsulated into the full **ODU3** frame, which includes the **ODU3 OH** and the **ODU3 payload**.
+
+On the right side of the diagram, the labels for the containers and JOH blocks are repeated: ODU, ODU2, ODU1, ODTU3.ts, ODTU23, ODTU13, ODTUG3 (PT = 21), OPU3, and ODU3. The bottom row of JOH blocks shows the individual streams (ODTU3.ts, ODTU23, ODTU13, ODU (0, 2e, flex), ODU2, ODU1) being mapped into the ODTUG3 payload.
+
+Diagram showing the multiplexing of ODU0, ODU1, ODU2, ODU2e, and ODUflex into ODU3 via ODTUG3 (PT=21).
+
+G.709-Y.1331(12)\_F7-6
+
+Figure 7-6 – ODU0, ODU1, ODU2, ODU2e and ODUflex into ODU3 multiplexing method via ODTUG3 (PT=21)
+
+Figure 7-7 presents the multiplexing of up to eighty ODU0 signals and/or up to forty ODU1 signals and/or up to ten ODU2 signals and/or up to ten ODU2e signals and/or up to two ODU3 signals and/or up to eighty ODUflex signals into the OPU4 signal via the ODTUG4 (PT=21). An ODU0 signal is extended with a frame alignment overhead and asynchronously mapped into the optical data tributary unit 4.1 (ODTU4.1) using the GMP justification overhead (JOH). An ODU1 signal is extended with a frame alignment overhead and asynchronously mapped into the optical data tributary unit 4.2 (ODTU4.2) using the GMP justification overhead. An ODU2 signal is extended with a frame alignment overhead and asynchronously mapped into the optical data tributary unit 4.8 (ODTU4.8) using the GMP justification overhead (JOH). An ODU2e signal is extended with a frame alignment overhead and asynchronously mapped into the optical data tributary unit 4.8 (ODTU4.8) using the GMP justification overhead. An ODU3 signal is extended with a frame alignment overhead and asynchronously mapped into the optical data tributary unit 4.31 (ODTU4.31) using the GMP justification overhead. An ODUflex signal is extended with a frame alignment overhead and asynchronously mapped into the optical data tributary unit 4.ts (ODTU4.ts) using the GMP justification overhead (JOH). Up to eighty ODTU4.1 signals, up to forty ODTU4.2 signals, up to ten ODTU4.8 signals, up to two ODTU4.31 and up to eighty ODTU4.ts signals are time-division multiplexed into the optical data tributary unit group 4 (ODTUG4) with payload type 21, after which this signal is mapped into the OPU4.
+
+![Diagram showing the multiplexing hierarchy from ODU to ODU4 via ODTU4.ts, ODTUG4, and OPU4.](ed48e24e36ea0501953177401c900f86_img.jpg)
+
+The diagram illustrates a top-down mapping process: 
+ 1. At the top, an **ODU** block is split into **ODU OH** and **ODU payload**.
+ 2. This is mapped into an **ODTU4.ts** block containing **ODTU4.ts JOH** and the **ODU (0, 1, 2, 2e, 3, flex)** payload.
+ 3. Multiple **ODTU4.ts** units (represented by multiple boxes with **ODTU4.ts JOH** and **ODU**) are multiplexed into a single **ODTUG4 (PT=21)** block.
+ 4. The **ODTUG4 (PT=21)** is then mapped into an **OPU4** block, which consists of **OPU4 OH** and **OPU4 payload**.
+ 5. Finally, the **OPU4** is mapped into the **ODU4** block, consisting of **ODU4 OH** and **ODU4 payload**.
+
+Diagram showing the multiplexing hierarchy from ODU to ODU4 via ODTU4.ts, ODTUG4, and OPU4.
+
+G.709-Y.1331(12) F7-7
+
+**Figure 7-7 – ODU0, ODU1, ODU2, ODU2e, ODU3 and ODUflex into ODU4 multiplexing method via ODTUG4 (PT=21)**
+
+Figure 7-8 presents the multiplexing of up to 10n ODU0 signals and/or up to 10n ODU1 signals and/or up to 10n ODU2 signals and/or up to 10n ODU2e signals and/or up to  $\lfloor 2.5n \rfloor$  ODU3 signals and/or up to n ODU4 signals and/or up to 10n ODUflex signals into the OPUCn signal via the ODTUGCn (PT=22). An ODUk signal is extended with frame alignment overhead and asynchronously mapped into the Optical Data Tributary Unit Cn.ts (ODTUCn.ts) ( $\langle k, ts \rangle = \langle 0, 1 \rangle, \langle 1, 1 \rangle, \langle 2, 2 \rangle, \langle 2e, 2 \rangle, \langle 3, 8 \rangle, \langle 4, 20 \rangle, \langle flex, ts \rangle$ ) using the GMP justification overhead (JOH). Up to 10n ODTUCn.1 signals, up to 10n ODTUCn.2 signals, up to  $\lfloor 2.5n \rfloor$  ODTUCn.8 signals, up to n ODTUCn.10 signals and up to 10n ODTUCn.ts signals are time-division multiplexed into the Optical
+
+Data Tributary Unit Group Cn (ODTUGCn) with Payload Type 22, after which this signal is mapped into the OPUCn.
+
+![Diagram illustrating the multiplexing method for various ODU signals into ODUCn via ODTUGCn (PT=22).](7f5df81190b8dc50dad2604562ae0715_img.jpg)
+
+The diagram illustrates the hierarchical multiplexing of Optical Data Unit (ODU) signals. At the top, an ODU signal is shown with its overhead (ODU OH) and payload. Below it, an ODTUCn.ts signal is shown, which contains an ODU signal of type (0, 1, 2, 2e, 3, 4, flex) and its associated Justification Overhead (JOH). This ODTUCn.ts signal is then shown being multiplexed into an ODTUGCn (PT = 22) signal. The ODTUGCn signal contains multiple ODTUCn.ts JOH signals and multiple ODU signals. Below the ODTUGCn signal, the ODTUGCn.ts (PT = 22) signal is shown. This is then mapped into an OPUCn signal, which consists of the OPUCn OH and the OPUCn payload. Finally, the OPUCn signal is shown being mapped into an ODUCn signal, which consists of the ODUCn OH and the ODUCn payload. The diagram uses dashed lines and arrows to show the flow and mapping of these signals.
+
+Diagram illustrating the multiplexing method for various ODU signals into ODUCn via ODTUGCn (PT=22).
+
+G.709-Y.1331(20)\_F7-8
+
+**Figure 7-8 – ODU0, ODU1, ODU2, ODU2e, ODU3, ODU4 and ODUflex into ODUCn multiplexing method via ODTUGCn (PT=22)**
+
+Figure 7-9 presents the multiplexing of up to twenty ODU0 signals and/or up to ten ODU1 signals and/or up to two ODU2 signals and/or up to two ODU2e signals and/or up to twenty ODUflex signals into the OPU25 signal via the ODTUG25 (PT=21). An ODU0 signal is extended with a frame alignment overhead and asynchronously mapped into the optical data tributary unit 25.1 (ODTU25.1) using the GMP justification overhead (JOH). An ODU1 signal is extended with a frame alignment overhead and asynchronously mapped into the optical data tributary unit 25.2 (ODTU25.2) using the GMP justification overhead. An ODU2 signal is extended with a frame alignment overhead and asynchronously mapped into the optical data tributary unit 25.8 (ODTU25.8) using the GMP justification overhead. An ODU2e signal is extended with a frame alignment overhead and asynchronously mapped into the optical data tributary unit 25.8 (ODTU25.8) using the GMP justification overhead. An ODUflex signal is extended with a frame alignment overhead and asynchronously mapped into the optical data tributary unit 25.ts (ODTU25.ts) using the GMP justification overhead (JOH). Up to twenty ODTU25.1 signals, up to ten ODTU25.2 signals, up to two ODTU25.8 signals and up to twenty ODTU25.ts signals are time-division multiplexed into the optical data tributary unit group 25 (ODTUG25) with payload type 21, after which this signal is mapped into the OPU25.
+
+![Diagram illustrating the multiplexing of ODU0, ODU1, ODU2, ODU2e, and ODUflex signals into an ODU25 signal via ODTUG25 (PT=21).](77959075c823bb5169480d7b8ff82a63_img.jpg)
+
+The diagram illustrates the multiplexing hierarchy for ODU25. At the top, an ODU signal consists of ODU OH and ODU payload. This is mapped into an ODTU25.ts structure which includes ODU (0, 1, 2, 2e, flex) and ODTU25.ts JOH (Justification Overhead). Multiple ODTU25.ts units are multiplexed into an ODTUG25 (Optical Data Tributary Unit Group 25) with Payload Type (PT) = 21. This group is then mapped into an OPU25 (Optical Payload Unit 25) consisting of OPU25 OH and OPU25 payload. Finally, the OPU25 is wrapped into an ODU25 (Optical Data Unit 25) structure with ODU25 OH and ODU25 payload.
+
+G.709-Y.1331(20)\_F7-9
+
+Diagram illustrating the multiplexing of ODU0, ODU1, ODU2, ODU2e, and ODUflex signals into an ODU25 signal via ODTUG25 (PT=21).
+
+**Figure 7-9 – ODU0, ODU1, ODU2, ODU2e and ODUflex  
+into ODU25 multiplexing method via ODTUG25 (PT=21)**
+
+Figure 7-10 presents the multiplexing of up to forty ODU0 signals and/or up to twenty ODU1 signals and/or up to five ODU2 signals and/or up to five ODU2e signals and/or up to one ODU3 signals and/or up to forty ODUflex signals into the OPU50 signal via the ODTUG50 (PT=21). An ODU0 signal is extended with a frame alignment overhead and asynchronously mapped into the optical data tributary unit 50.1 (ODTU50.1) using the GMP justification overhead (JOH). An ODU1 signal is extended with a frame alignment overhead and asynchronously mapped into the optical data tributary unit 50.2 (ODTU50.2) using the GMP justification overhead. An ODU2 signal is extended with a frame alignment overhead and asynchronously mapped into the optical data tributary unit 50.8 (ODTU50.8) using the GMP justification overhead (JOH). An ODU2e signal is extended with a frame alignment overhead and asynchronously mapped into the optical data tributary unit 50.8 (ODTU50.8) using the GMP justification overhead. An ODU3 signal is extended with a frame alignment overhead and asynchronously mapped into the optical data tributary unit 50.31 (ODTU50.31) using the GMP justification overhead. An ODUflex signal is extended with a frame alignment overhead and asynchronously mapped into the optical data tributary unit 50.ts (ODTU50.ts) using the GMP justification overhead (JOH). Up to forty ODTU50.1 signals, up to twenty ODTU50.2 signals, up to five ODTU50.8 signals, up to one ODTU50.31 and up to forty ODTU50.ts signals are time-division multiplexed into the optical data tributary unit group 50 (ODTUG50) with payload type 21, after which this signal is mapped into the OPU50.
+
+![Diagram illustrating the ODU0, ODU1, ODU2, ODU2e, ODU3 and ODUflex into ODU50 multiplexing method via ODTUG50 (PT=21).](5eb69662cc4fa7d0d49b4eb22951c204_img.jpg)
+
+The diagram shows the hierarchical structure of OTN signals for multiplexing into an ODU50 signal. At the top, an ODU signal is shown with an ODU OH and an ODU payload. Below it, an ODTU50.ts signal is shown with an ODTU50.ts JOH and an ODU (0, 1, 2, 2e, 3, flex) payload. This ODU payload is further divided into multiple ODTU50.ts JOH signals and multiple ODU signals, which are then multiplexed into an ODTUG50 (PT = 21) signal. This ODTUG50 signal is then mapped into an OPU50 signal, which consists of an OPU50 OH and an OPU50 payload. Finally, the OPU50 payload is mapped into an ODU50 signal, which consists of an ODU50 OH and an ODU50 payload.
+
+Diagram illustrating the ODU0, ODU1, ODU2, ODU2e, ODU3 and ODUflex into ODU50 multiplexing method via ODTUG50 (PT=21).
+
+G.709-Y.1331(20)\_F7-10
+
+**Figure 7-10 – ODU0, ODU1, ODU2, ODU2e, ODU3 and ODUflex into ODU50 multiplexing method via ODTUG50 (PT=21)**
+
+Details of the multiplexing method and mappings are given in clause 19 for OPUk and clause 20 for OPUCn.
+
+Some examples illustrating the multiplexing of 2 ODU0 signals into an ODU1 and of 4 ODU1 signals into an ODU2 are presented in Appendix III.
+
+## 7.5 Interconnection of Ethernet UNI and FlexE Group UNI in two administrative domains in the OTN
+
+Ethernet PCS encoded client signals and Ethernet MAC client signals can be applied to the OTN via an Ethernet UNI and a FlexE group UNI.
+
+The mapping method specified in clause 17 for the Ethernet PCS encoded client signals when applied via an Ethernet UNI are BMP, TTT+GMP and GMP, and via a FlexE group UNI is IMP.
+
+The mapping method specified in clause 17 for the Ethernet MAC client signals with a bit rate up to and including 100 Gbit/s when applied via an Ethernet UNI is GFP-F and optionally can be IMP, and via a FlexE group UNI is IMP. The mapping method specified in clause 17 for both Ethernet MAC client and FlexE Client signals with a bit rate including and beyond 100 Gbit/s is IMP.
+
+For the case of Ethernet PCS encoded client services between an Ethernet UNI in one administrative domain and a FlexE group UNI in another administrative domain, the rule for interconnecting an Ethernet PCS encoded client signal will be to use BMP, TTT+GMP or GMP on the interface between the two administrative domains.
+
+For the case of Ethernet MAC client services with a bit rate up to and including 100 Gbit/s between an Ethernet UNI that applies the GFP-F mapping method in one administrative domain and a FlexE group UNI or an Ethernet UNI that applies the IMP mapping method in another administrative domain, the rule for interconnecting an Ethernet MAC client signal with a bit rate up to 100 Gbit/s will be to use GFP-F on the interface between the two administrative domains.
+
+NOTE – For the case of Ethernet MAC client services with a bit rate including and beyond 100 Gbit/s between an Ethernet UNI in one administrative domain and a FlexE group UNI or an Ethernet UNI in another administrative domain, IMP mapping is used as the interconnect for the interface between the two administrative domains.
+
+# 8 OTN Interfaces
+
+## 8.1 Point-to-point interface, type I
+
+The OTN point-to-point interface type I supports either one OTU on one OTSiG or one FlexO-x-<fec> (out of one OTUCn/FlexO-x-<fec>-m group) on one OTSiG on a single optical span with 3R regeneration at each end. The OTSiG is composed of one or more OTSi.
+
+Application codes of the optical interface signal carrying the OTU or FlexO-x-<fec> are contained in [ITU-T G.959.1] and [ITU-T G.693] and [ITU-T G.695].
+
+Vendor specific application identifiers of the interfaces carrying these OTUs and FlexOs are outside the scope of this Recommendation.
+
+## 8.2 Point-to-point interface, type II
+
+The OTN point-to-point interface, type II supports n OTU and/or OTUCn/FlexO-x-RS-<fec>-m signals on n OTSiG on a single optical span with 3R regeneration at each end. Each OTSiG is composed of one or more OTSi.
+
+At least one of the OTU signals is present during normal operation.
+
+There is no predefined order in which the OTU signals are taken into service.
+
+NOTE – OTN point-to-point optical layer interface overhead is not defined. The interface will use the OTU SMOH in this multi-channel interface for supervision and management. The interface connectivity (TIM) failure reports will be computed from the individual OTU reports by means of failure correlation in fault management. Refer to the equipment Recommendations for further details.
+
+Application codes of the optical interface signal carrying n OTU or FlexO-x-<fec> signals are contained in [ITU-T G.959.1] and [ITU-T G.695].
+
+Vendor specific application identifiers of the interfaces carrying these OTUs are outside the scope of this Recommendation.
+
+## 8.3 Optical networking interface, type II
+
+The OTN optical networking interfaces, type II carry one or more optical tributary signals, each transporting an OTUk or an OTUCn or one FlexO-x-<fec> out of an OTUCn/FlexO-x-<fec>-m group or a non-OTN client signal and OCh-O or OTSiG-O carried by an OCC. The OTUk, OTUCn or FlexO-x-<fec> is carried over an OTSi.
+
+The OTN optical networking interfaces, type II may carry one optical tributary signal, transporting an OTUk or an OTUCn or one FlexO-x-<fec> out of an OTUCn/FlexO-x-<fec>-m group or a non-OTN client signal and OCh-O or OTSiG-O carried by an OCC. The OTUk, OTUCn or FlexO-x-<fec> is carried over an OTSi.
+
+The OTN optical networking interfaces, type II may carry more than one optical tributary signals, each transporting an OTUCn or one FlexO-x-<fec> out of an OTUCn/FlexO-x-<fec>-m group or a non-OTN client signal and OCh-O or OTSiG-O carried by an OCC. The OTUCn or FlexO-x-<fec> is carried over an OTSi.
+
+Application codes of the optical tributary signal carrying the OTUk or FlexO-x-<fec> are contained in [ITU-T G.698.1] and [ITU-T G.698.2].
+
+Specifications of the OCC carrying the OCh-O or OTSiG-O are contained in [ITU-T G.7712].
+
+Vendor specific application identifiers of the OTSi carrying these OTUks or OTUCns or FlexO-x-<fec>s are outside the scope of this Recommendation.
+
+## 8.4 Optical networking interface, type I
+
+The OTN optical networking interfaces, type I carry one or more optical tributary signals, each transporting an OTUk or an OTUCn or one FlexO-x-<fec> out of an OTUCn/FlexO-x-<fec>-m group or a non-OTN client signal and OTS-O, OMS-O and OCh-O carried by an OSC and OTSiG-O carried by an OSC or partly carried by other means. 3R regeneration is not required at the interface.
+
+Application codes of the optical tributary signal carrying the OTUk or FlexO-x-<fec> are contained in [ITU-T G.698.1] and [ITU-T G.698.2].
+
+Vendor specific application identifiers of the OTSi or OTSiG carrying these OTUs or FlexO-x-<fec>s are outside the scope of this Recommendation.
+
+# 9 Media Element
+
+A description of the media element will be provided in [ITU-T G.872].
+
+# 10 OCh and OTSiA
+
+The OCh and OTSiA transport a digital client signal between 3R regeneration points. The OCh and OTSiA client signals defined in this Recommendation are the OTUk, OTUk-v, OTUkV and OTUCn signals.
+
+## 10.1 OCh
+
+The OCh structure is conceptually shown in Figure 10-1. The OCh contains two parts: an overhead part (OCh-O) and a payload part (OTSiG).
+
+![Figure 10-1: OCh information structure diagram](5dca16cd6224cb81fefbd38274e5eb80_img.jpg)
+
+The diagram shows two adjacent rectangular boxes. The left box is labeled "OCh-O" and the right box is labeled "OTSiG". Below the boxes, the text "G.709-Y.1331(20)\_F10-1" is displayed.
+
+Figure 10-1: OCh information structure diagram
+
+Figure 10-1 – OCh information structure
+
+## 10.2 Optical tributary signal assembly (OTSiA)
+
+The OTSiA structure is conceptually shown in Figure 10-2. The OTSiA contains two parts: a payload part (OTSiG) and an overhead part (OTSiG-O).
+
+![Figure 10-2: OTSiA information structure diagram](5d450dd0c0bf1cda8a30b736d88d937a_img.jpg)
+
+The diagram shows two adjacent rectangular boxes. The left box is labeled "OTSiG-O" and the right box is labeled "OTSiG". Below the boxes, the text "G.709-Y.1331(16)-Cor.2(19)\_F10-2" is displayed.
+
+Figure 10-2: OTSiA information structure diagram
+
+Figure 10-2 – OTSiA information structure
+
+# 11 Optical transport unit (OTU)
+
+The OTUk[V] conditions the ODUk for transport over an OCh network connection. The OTUk frame structure, including the OTUk FEC is completely standardized. The OTUkV is a frame structure, including the OTUkV FEC that is only functionally standardized (i.e., only the required functionality
+
+is specified); refer to Appendix II. Besides these two, there is an OTUkV in which the completely standardized OTUk frame structure is combined with a functionally standardized OTUkV FEC; refer to appendix II. This combination is identified as OTUk-v.
+
+The OTUCn frame structure is defined without an OTUCn FEC area. The FEC associated with an OTUCn is interface dependent and specified as an element of each interface.
+
+The OTU25 and OTU50 frame structure is defined without an OTU FEC area. The FEC associated with an OTU25 and OTU50 is interface dependent and specified as an element of each interface.
+
+## 11.1 OTUk (k=1,2,3,4,4-SC) frame structure
+
+The OTUk (k = 1,2,3,4,4-SC) frame structure is based on the ODUk frame structure and extends it with a forward error correction (FEC) as shown in Figure 11-1. 256 columns are added to the ODUk frame for the FEC and the reserved overhead bytes in row 1, columns 8 to 14 of the ODUk overhead are used for an OTUk specific overhead, resulting in an octet-based block frame structure with four rows and 4080 columns. The MSB in each octet is bit 1, the LSB is bit 8.
+
+NOTE – This Recommendation does not specify an OTUk frame structure for k=0, k=2e or k=flex. See Annex G for the specification of OTU0LL.
+
+![Diagram of OTUk frame structure showing the relationship between ODUk and OTUk frames. The ODUk frame is 3824 columns wide and 4 rows high. The OTUk frame is 4080 columns wide and 4 rows high. The OTUk frame is composed of the ODUk frame plus an OTUk FEC area (4 x 256 bytes) added to the right. The first row of the OTUk frame contains FA OH (columns 1-7) and OTUk OH (columns 8-14). The OTUk FEC area starts at column 3825 and ends at column 4080.](030c758fd425016b03290c8f11bef69d_img.jpg)
+
+The diagram illustrates the frame structure of OTUk. At the top, an ODUk frame is shown as a rectangle with 4 rows (labeled 1, 2, 3, 4 on the left) and 3824 columns (labeled 1 and 3824 at the top). Below it, an arrow labeled 'ODUk' points to the OTUk frame structure. The OTUk frame is a larger rectangle with 4 rows (labeled 1, 2, 3, 4 on the left) and 4080 columns (labeled 1, 14, 15, 3824, 3825, 4080 at the top). The first row of the OTUk frame is divided into three parts: 'FA OH' (columns 1-7), 'OTUk OH' (columns 8-14), and a large section from column 15 to 3824. The rightmost section, from column 3825 to 4080, is labeled 'OTUk FEC' and '(4 x 256 bytes)'. The label 'OTUk' is centered below the frame structure. A small text 'G.709-Y.1331(12)\_F11-1' is in the bottom right corner.
+
+Diagram of OTUk frame structure showing the relationship between ODUk and OTUk frames. The ODUk frame is 3824 columns wide and 4 rows high. The OTUk frame is 4080 columns wide and 4 rows high. The OTUk frame is composed of the ODUk frame plus an OTUk FEC area (4 x 256 bytes) added to the right. The first row of the OTUk frame contains FA OH (columns 1-7) and OTUk OH (columns 8-14). The OTUk FEC area starts at column 3825 and ends at column 4080.
+
+Figure 11-1 – OTUk frame structure
+
+The bit rates of the OTUk signals are defined in Table 7-1.
+
+The OTUk forward error correction (FEC) area contains an interface specific FEC type. Two FEC types are specified:
+
+### Reed-Solomon RS(255,239) FEC
+
+The OTUk (k=1,2,3,4) FEC area contains the Reed-Solomon RS(255,239) FEC codes. Transmission of the OTUk FEC is mandatory for k=4 and optional for k=1,2,3. If no FEC is transmitted, fixed stuff bytes (all-0s pattern) are to be used.
+
+The RS(255,239) FEC code shall be computed as specified in Annex A.
+
+For interworking of equipment supporting FEC, with equipment not supporting FEC (inserting fixed stuff all-0s pattern in the OTUk (k=1,2,3) FEC area), the FEC supporting equipment shall support the capability to disable the FEC decoding process (ignore the content of the OTUk (k=1,2,3) FEC).
+
+### Staircase FEC
+
+The OTU4 FEC area contains the Stair Case FEC codes as specified in [ITU-T G.709.2] and the resulting signal is referred to as OTU4-SC.
+
+The transmission order of the bits in the OTUk frame is left to right, top to bottom, and MSB to LSB (see Figure 11-2).
+
+![Figure 11-2: Transmission order of the OTUk frame bits. The diagram shows a grid representing an OTUk frame with 4 rows and 4080 columns. Horizontal dashed arrows indicate that transmission proceeds from left to right across each row, starting from row 1 and ending at row 4. A zoomed-in box on row 4 shows a single byte divided into 8 bits, labeled 1 through 8, with bit 1 designated as the MSB (Most Significant Bit) and bit 8 as the LSB (Least Significant Bit).](cbb2d311b20781a595488445ded48d0a_img.jpg)
+
+Figure 11-2: Transmission order of the OTUk frame bits. The diagram shows a grid representing an OTUk frame with 4 rows and 4080 columns. Horizontal dashed arrows indicate that transmission proceeds from left to right across each row, starting from row 1 and ending at row 4. A zoomed-in box on row 4 shows a single byte divided into 8 bits, labeled 1 through 8, with bit 1 designated as the MSB (Most Significant Bit) and bit 8 as the LSB (Least Significant Bit).
+
+G.709-Y.1331(12)\_F11-2
+
+**Figure 11-2 – Transmission order of the OTUk frame bits**
+
+## 11.2 Scrambling for OTUk (k=1,2,3,4)
+
+The OTUk (k=1,2,3,4) signal must have sufficient bit timing content at the ONNI. A suitable bit pattern, which prevents a long sequence of "1"s or "0"s, is provided by using a scrambler.
+
+The operation of the scrambler shall be functionally identical to that of a frame synchronous scrambler of sequence length 65535 operating at the OTUk rate.
+
+The generating polynomial shall be  $1 + x + x^3 + x^{12} + x^{16}$ . Figure 11-3 shows a functional diagram of the frame synchronous scrambler.
+
+![Figure 11-3: Frame synchronous scrambler. This is a logic diagram of a 16-stage linear feedback shift register (LFSR). It consists of 16 D-type flip-flops (labeled DQ S) connected in series. Feedback is taken from the outputs of stages 1, 3, 12, and 16, which are combined using XOR gates (represented by circles with plus signs). The 'Data in' is XORed with the feedback from the 16th stage before being fed into the first stage. The 'Scrambled data out' is produced by XORing the 'Data in' with the output of the 16th stage. An external signal 'OTUk MSB of MFAS byte' is shown as a reset or synchronization point for the register. All flip-flops are clocked by a common 'OTUk clock'.](24a89bcaba787f2bc1721356480a4a01_img.jpg)
+
+Figure 11-3: Frame synchronous scrambler. This is a logic diagram of a 16-stage linear feedback shift register (LFSR). It consists of 16 D-type flip-flops (labeled DQ S) connected in series. Feedback is taken from the outputs of stages 1, 3, 12, and 16, which are combined using XOR gates (represented by circles with plus signs). The 'Data in' is XORed with the feedback from the 16th stage before being fed into the first stage. The 'Scrambled data out' is produced by XORing the 'Data in' with the output of the 16th stage. An external signal 'OTUk MSB of MFAS byte' is shown as a reset or synchronization point for the register. All flip-flops are clocked by a common 'OTUk clock'.
+
+G.709-Y.1331(12)\_F11-3
+
+**Figure 11-3 – Frame synchronous scrambler**
+
+The scrambler shall be reset to "FFFF" (HEX) on the most significant bit of the byte following the last framing byte in the OTUk frame, i.e., the MSB of the MFAS byte. This bit, and all subsequent bits to be scrambled shall be added modulo 2 to the output from the  $x^{16}$  position of the scrambler. The scrambler shall run continuously throughout the complete OTUk frame. The framing bytes (FAS) of the OTUK overhead shall not be scrambled.
+
+Scrambling is performed after FEC computation and insertion into the OTUk signal.
+
+## 11.3 OTUCn frame structure
+
+The OTUCn frame structure (Figure 11-4) is based on the ODUCn frame structure and deploys the reserved overhead bytes in row 1, columns 8 to 14 of each ODU frame structure in the ODUCn overhead for an OTUCn specific overhead, resulting in an octet-based block frame structure with  $n \times$  four rows and 3824 columns. The MSB in each octet is bit 1, the LSB is bit 8.
+
+Interleaving of the n frame and multi-frame synchronous OTU frame structure instances within the OTUCn, forward error correction, encoding (e.g., scrambling), deskewing and transmission order of the OTUCn are interface specific and specified for inter-domain OTN interfaces with application codes in the interface specific Recommendations (ITU-T G.709.x series). For OTN interfaces with vendor specific application identifiers these specifications are vendor specific and out of scope of this Recommendation.
+
+The bit rates of the OTUCn signals are defined in Table 7-1.
+
+![Diagram of OTUCn frame structure showing the mapping of ODU frames into OTU frames. It illustrates the overhead structure (FA OH and OTU OH) and the payload mapping for multiple ODU frames (ODU frame structure #1 and ODU frame structure #2...#n) into the OTU frame structure.](e8e818455bb0d1a6153299a388b94868_img.jpg)
+
+The diagram illustrates the frame structure for OTUCn. It shows two levels of frame mapping. The top level shows the mapping of an ODU frame structure (rows 1-4, columns 1-3824) into an OTU frame structure (rows 1-4, columns 1-3824). The bottom level shows the mapping of multiple ODU frame structures (rows 1-4, columns 1-3824) into an OTU frame structure (rows 1-4, columns 1-3824). The OTU frame structure includes a Forward Error Correction (FEC) overhead (FA OH) and an OTU overhead (OTU OH) in row 1, columns 1-14. The payload is mapped into the remaining columns (15-3824).
+
+Diagram of OTUCn frame structure showing the mapping of ODU frames into OTU frames. It illustrates the overhead structure (FA OH and OTU OH) and the payload mapping for multiple ODU frames (ODU frame structure #1 and ODU frame structure #2...#n) into the OTU frame structure.
+
+**Figure 11-4 – OTUCn frame structure**
+
+## 11.4 OTU25 and OTU50 frame structure
+
+The OTU25 and OTU50 frame structure is based on the ODUk (k=25, 50) frame structure and deploys the reserved overhead bytes in row 1, columns 8 to 14 of the ODUk overhead for an OTU specific overhead, resulting in an octet-based block frame structure with four rows and 3824 columns. The MSB in each octet is bit 1, the LSB is bit 8.
+
+Forward error correction, encoding (e.g., scrambling), deskewing and transmission order of the OTU25 and OTU50 are specified for inter-domain OTN interfaces with application codes in the interface specific Recommendations [ITU-T G.709.4].
+
+The bit rates of the OTU25 and OTU50 signals are defined in Table 7-1.
+
+![Diagram of OTU25 and OTU50 frame structure showing the mapping of an ODUk frame into an OTU frame. It illustrates the overhead structure (FA OH and OTUk OH) and the payload mapping for OTU25 and OTU50 signals.](1e8c50ad4fca7f315a407347dd5091cc_img.jpg)
+
+The diagram illustrates the frame structure for OTU25 and OTU50. It shows the mapping of an ODUk frame structure (rows 1-4, columns 1-3824) into an OTU frame structure (rows 1-4, columns 1-3824). The OTU frame structure includes a Forward Error Correction (FEC) overhead (FA OH) and an OTUk overhead (OTUk OH) in row 1, columns 1-14. The payload is mapped into the remaining columns (15-3824). The mapping is labeled OTU25, OTU50.
+
+Diagram of OTU25 and OTU50 frame structure showing the mapping of an ODUk frame into an OTU frame. It illustrates the overhead structure (FA OH and OTUk OH) and the payload mapping for OTU25 and OTU50 signals.
+
+**Figure 11-5 – OTU25 and OTU50 frame structure**
+
+# 12 Optical data unit (ODU)
+
+## 12.1 ODU frame structure
+
+The ODU frame structure is shown in Figure 12-1. It is organized in an octet-based block frame structure with four rows and 3824 columns.
+
+The ODU<sub>k</sub> (k=0,1,2,2e,3,4,flex) frame structure contains one instance of the ODU frame structure. The ODUC<sub>n</sub> frame structure contains n frame and multi-frame synchronous instances of the ODU frame structures, numbered 1 to n (ODU #1 to ODU #n).
+
+![Diagram of ODU frame structure showing a 4x3824 grid. Columns 1-14 are ODU overhead area, columns 15-3824 are OPU area. Row 1, columns 1-14 are reserved for FA and OTU overhead.](a161a2bbb4d830e847ccb4f44b7e41a9_img.jpg)
+
+The diagram illustrates the ODU frame structure as a grid with 4 rows and 3824 columns. The columns are numbered 1, ..., 14, 15, ..., 3824. The rows are numbered 1, 2, 3, 4. The first 14 columns (1 to 14) are designated as the 'ODU overhead area'. The remaining columns (15 to 3824) are designated as the 'OPU area (4 × 3810 bytes)'. A legend indicates that the area in the first row, columns 1 to 14 is 'Area reserved for FA and OTU overhead.' The diagram is labeled G.709-Y.1331(16)\_F12-1.
+
+Diagram of ODU frame structure showing a 4x3824 grid. Columns 1-14 are ODU overhead area, columns 15-3824 are OPU area. Row 1, columns 1-14 are reserved for FA and OTU overhead.
+
+Figure 12-1 – ODU frame structure
+
+The two main areas of the ODU frame are:
+
+- ODU overhead area
+- OPU area.
+
+Columns 1 to 14 of the ODU are dedicated to ODU overhead area.
+
+NOTE – Columns 1 to 14 of row 1 are reserved for a frame alignment and OTU specific overhead.
+
+Columns 15 to 3824 of the ODU are dedicated to OPU area.
+
+## 12.2 ODU bit rates and bit-rate tolerances
+
+ODU<sub>k</sub> signals may be generated using either a local clock, or the recovered clock of the client signal. In the latter case the ODU<sub>k</sub> frequency and frequency tolerance are locked to the client signal's frequency and frequency tolerance. In the former case the ODU<sub>k</sub> frequency and frequency tolerance are locked to the local clock's frequency and frequency tolerance. The local clock frequency tolerance for the OTN is specified to be  $\pm 20$  ppm.
+
+ODUC<sub>n</sub> signals are generated using a local clock. The ODUC<sub>n</sub> frequency and frequency tolerance are locked to the local clock's frequency and frequency tolerance. The local clock frequency tolerance for the OTN is specified to be  $\pm 20$  ppm.
+
+ODU maintenance signals (ODU AIS, OCI, LCK) are generated using a local clock. In a number of cases this local clock may be the clock of a server ODU signal over which the ODU signal is transported between equipment or through equipment (in one or more of the tributary slots). For these cases, the nominal justification ratio should be deployed to comply with the ODU's bit-rate tolerance specification.
+
+### 12.2.1 ODU0, ODU1, ODU2, ODU3, ODU4, ODU25, ODU50, ODUC<sub>n</sub>
+
+The local clocks used to create the ODU0, ODU1, ODU2, ODU3, ODU4, ODU25, ODU50 and ODUC<sub>n</sub> signals are generated by clock crystals that are also used for the generation of SDH STM-N signals. The bit rates of these ODU<sub>k</sub> (k=0,1,2,3,4,25,50) and ODUC<sub>n</sub> signals are therefore related to the STM-N bit rates and the bit-rate tolerances are the bit-rate tolerances of the STM-N signals.
+
+The ODU0 bit rate is 50% of the STM-16 bit rate.
+
+The ODU1 bit rate is 239/238 times the STM-16 bit rate.
+
+The ODU2 bit rate is  $239/237$  times 4 times the STM-16 bit rate.
+
+The ODU3 bit rate is  $239/236$  times 16 times the STM-16 bit rate.
+
+The ODU4 bit rate is  $239/227$  times 40 times the STM-16 bit rate.
+
+The ODU25 bit rate is  $41118/41120$  times  $514/544$  times  $255/227$  times 10 times the STM-16 bit rate, which is equal to  $61677/58112$  times 10 times the STM-16 bit rate.
+
+The ODU50 bit rate is  $41118/41120$  times  $514/544$  times  $255/227$  times 20 times the STM-16 bit rate, which is equal to  $61677/58112$  times 20 times the STM-16 bit rate.
+
+The ODUCn bit rate is  $n$  times  $239/226$  times 40 times the STM-16 bit rate.
+
+ODU1, ODU2 and ODU3 signals which carry an STM-N ( $N = 16, 64, 256$ ) signal may also be generated using the timing of these client signals.
+
+Refer to Table 7-2 for the nominal bit rates and bit-rate tolerances.
+
+#### **12.2.1.1 ODUs (k=1,2,3,4), ODU25/50 and ODUCn transporting frequency synchronization information**
+
+The local clocks used to create the frequency synchronous OPU1/ODU1/OTU1, OPU2/ODU2/OTU2, OPU3/ODU3/OTU3, OPU4/ODU4/OTU4, OPU25/ODU25/OTU25, OPU50/ODU50/OTU50 and OPUCn/ODUCn/OTUCn/FlexO signals are generated by a synchronous equipment clock (SEC) function that is nominally locked to a primary reference clock (PRC). The bit rate tolerance of these frequency synchronous ODUs (and its OTUs) ( $k=1,2,3,4,4-SC$ ), ODU25/50 (and their OTU25/50) and ODUCn (and its OTUCn and FlexO) signals are therefore related to the bit-rate tolerances of the SEC. Refer to [ITU-T G.8262].
+
+During signal fail conditions, the frequency synchronous OTU and/or ODU signals are replaced by replacement signals (OTU-AIS and/or ODU-AIS) with a bit rate tolerance of  $\pm 20$  ppm.
+
+### **12.2.2 ODU2e**
+
+An ODU2e signal is generated using the timing of its client signal.
+
+The ODU2e bit rate is  $239/237$  times the 10GBASE-R client bit rate.
+
+Refer to Table 7-2 for the nominal bit rate and bit-rate tolerances.
+
+### **12.2.3 ODUflex for CBR client signals**
+
+An ODUflex(CBR) signal is generated using the timing of its client signal.
+
+The ODUflex bit rate is  $239/238$  times the adapted CBR client bit rate.
+
+The client signal may have a bit-rate tolerance up to  $\pm 100$  ppm.
+
+![Diagram of ODUflex clock generation for CBR signals. A CBR client signal is shown at the top, with a clock source labeled 'up to ± 100 ppm'. The signal flows through a series of blocks: BMP, OPUflex, ODUflex, GMP, ODTU, OPU, ODU, and OTU. A dashed line indicates that the ODUflex block can be bypassed. At the bottom, a clock source labeled '± 20 ppm' is connected to the ODTU, OPU, ODU, and OTU blocks. The diagram is labeled 'G.709-Y.1331(16)-Amd.2(18)_F12-2'.](38cbce07f83fba6d5a7c46605bd5743f_img.jpg)
+
+Diagram of ODUflex clock generation for CBR signals. A CBR client signal is shown at the top, with a clock source labeled 'up to ± 100 ppm'. The signal flows through a series of blocks: BMP, OPUflex, ODUflex, GMP, ODTU, OPU, ODU, and OTU. A dashed line indicates that the ODUflex block can be bypassed. At the bottom, a clock source labeled '± 20 ppm' is connected to the ODTU, OPU, ODU, and OTU blocks. The diagram is labeled 'G.709-Y.1331(16)-Amd.2(18)\_F12-2'.
+
+**Figure 12-2 – ODUflex clock generation for CBR signals**
+
+### 12.2.4 ODUflex for PRBS and Null test signals
+
+ODUflex(CBR) connections may be tested using a PRBS or NULL test signal as the client signal instead of the CBR client signal. For such a case, the ODUflex(PRBS) or ODUflex(NULL) signal should be generated with a frequency within the tolerance range of the ODUflex(CBR) signal.
+
+If the CBR client clock is present such ODUflex(PRBS) or ODUflex(NULL) signal may be generated using the CBR client clock, otherwise the ODUflex(PRBS) or ODUflex(NULL) signal is generated using a local clock.
+
+### 12.2.5 ODUflex for GFP-F mapped packet client signals
+
+ODUflex(GFP) signals are generated using a local clock. This clock may be the local server ODUk (or OTUk) clock, the local ODUCn (or OTUCn) clock, or an equipment internal clock of the signal over which the ODUflex is carried through the equipment. Refer to Appendix XV for examples on ODUflex(GFP) clock generation methods.
+
+Any bit rate is possible for an ODUflex(GFP) signal. The ODUflex(GFP) bit rate is specified as  $239/238 \times X$  Gbit/s  $\pm 100$  ppm, in which X represents the configured GFP-F encapsulated packet client nominal bidirectional bit rate.
+
+For ODUflex hitless resizing applications or for the case that the ODUflex(GFP) should fill an integral number of 1.25G tributary slots of the smallest server ODUk path over which the ODUflex(GFP) may be carried, a set of bit-rates with values  $n \times \text{ODUk.ts}$  that meet this criterion are specified in Table 7-8. The derivation of the specific ODUflex(GFP,n,k) values is provided in Appendix XI.
+
+![Figure 12-3: ODUflex clock generation for GFP-F mapped packet client signals. The diagram shows two signal paths. The left path shows GFP-F, OPUflex, ODUflex, GMP, ODTU, OPU, ODU, and OTU. Clocks are indicated for OPUflex (up to ±100 ppm) and ODU (±20 ppm), with a note 'May be related'. The right path shows GFP-F, OPUflex, ODUflex, GMP, ODTUk.ts, OPUk, ODUk, (A) GMP, ODTUCn.ts, OPUcn, ODUCn, and OTUCn. Clocks are indicated for OPUflex (up to ±100 ppm), OPUk (±20 ppm), and ODUCn (±20 ppm), with a note 'May be related'. A reference code G.709-Y.1331(16)_F12-3 is present.](12c19090355e19922e23044633b9d1ea_img.jpg)
+
+Figure 12-3: ODUflex clock generation for GFP-F mapped packet client signals. The diagram shows two signal paths. The left path shows GFP-F, OPUflex, ODUflex, GMP, ODTU, OPU, ODU, and OTU. Clocks are indicated for OPUflex (up to ±100 ppm) and ODU (±20 ppm), with a note 'May be related'. The right path shows GFP-F, OPUflex, ODUflex, GMP, ODTUk.ts, OPUk, ODUk, (A) GMP, ODTUCn.ts, OPUcn, ODUCn, and OTUCn. Clocks are indicated for OPUflex (up to ±100 ppm), OPUk (±20 ppm), and ODUCn (±20 ppm), with a note 'May be related'. A reference code G.709-Y.1331(16)\_F12-3 is present.
+
+**Figure 12-3 – ODUflex clock generation for GFP-F mapped packet client signals**
+
+### 12.2.6 ODUflex for IMP mapped client signals
+
+ODUflex(IMP) signals are generated using a local clock or the timing of its client signal. The local clock may be the local server ODUk (or OTUk) clock, the local ODUCn (or OTUCn) clock, or an equipment internal clock of the signal over which the ODUflex is carried through the equipment. Refer to Appendix XV for examples on ODUflex(IMP) clock generation methods.
+
+Any bit rate is possible for an ODUflex(IMP) signal. The ODUflex(IMP) bit rate is specified as  $239/238 \times X$  Gbit/s  $\pm 100$  ppm, in which X represents the configured 64B/66B encoded packet client nominal bidirectional bit rate.
+
+For the case that the ODUflex(IMP) would carry a FlexE Client signal with a bit rate of  $s \times 5,156,250.000$  kbit/s  $\pm 100$  ppm and  $s = 2, 8$  or  $n \times 5$  ( $n \geq 1$ ), the ODUflex(IMP,s) bit rate is  $s \times 239/238 \times 5,156,250.000$  kbit/s  $\pm 100$  ppm.
+
+![Diagram of ODUflex clock generation for IMP mapped packet client signals. The flow starts with a Packet client leading to an Ethernet MAC frame, which is then 64b/66b encoded. This signal passes through IMP, OPUflex, ODUflex, GMP, ODTU, OPU, and finally ODU. Clock signals are shown at various points: 'up to ± 100 ppm' at the 64b/66b encoded stage, 'up to ± 100 ppm' at the ODUflex stage, and '± 20 ppm' at the OPU stage. Dashed lines labeled 'May be related' connect these clock signals to the IMP, OPUflex, and ODU stages.](5ee1bbbf85b473f78af9ec8368a4159a_img.jpg)
+
+Diagram of ODUflex clock generation for IMP mapped packet client signals. The flow starts with a Packet client leading to an Ethernet MAC frame, which is then 64b/66b encoded. This signal passes through IMP, OPUflex, ODUflex, GMP, ODTU, OPU, and finally ODU. Clock signals are shown at various points: 'up to ± 100 ppm' at the 64b/66b encoded stage, 'up to ± 100 ppm' at the ODUflex stage, and '± 20 ppm' at the OPU stage. Dashed lines labeled 'May be related' connect these clock signals to the IMP, OPUflex, and ODU stages.
+
+**Figure 12-4 – ODUflex clock generation for IMP mapped packet client signals**
+
+# 13 Optical payload unit (OPU)
+
+The OPU frame structure is shown in Figure 13-1. It is organized in an octet-based block frame structure with four rows and 3810 columns.
+
+The OPUk (k=0,1,2,2e,3,4,flex,25,50) frame structure contains one instance of the OPU frame structure. The OPUCn frame structure contains n frame and multi-frame synchronous instances of the OPU frame structure, numbered 1 to n (OPU #1 to OPU #n).
+
+![](9cbc1ebd80813fc36e499f7d70ed6881_img.jpg)
+
+|       |   |                                               |    |    |       |      |
+|-------|---|-----------------------------------------------|----|----|-------|------|
+|       |   | 15                                            | 16 | 17 | ..... | 3824 |
+| Row # | 1 | <b>OPUk overhead area</b>                     |    |    |       |      |
+|       | 2 |                                               |    |    |       |      |
+|       | 3 |                                               |    |    |       |      |
+|       | 4 |                                               |    |    |       |      |
+|       |   | <b>OPUk payload area<br/>(4 × 3808 bytes)</b> |    |    |       |      |
+
+G.709-Y.1331(12)\_F13-1
+
+**Figure 13-1 – OPU frame structure**
+
+The two main areas of the OPU frame are:
+
+- OPU overhead area;
+- OPU payload area.
+
+Columns 15 to 16 of the OPU are dedicated to an OPU overhead area.
+
+Columns 17 to 3824 of the OPU are dedicated to an OPU payload area.
+
+NOTE – OPU column numbers are derived from the OPU columns in the ODU frame.
+
+# 14 Overhead information carried over the OSC and OCC
+
+## 14.1 OSC
+
+The overhead information carried over the OSC consists of the OTS-O, OMS-O, OCh-O and OTSiG-O. The information content of this overhead is defined in clause 15. The format, structure and bit rate of this overhead is not defined in this Recommendation.
+
+### General management communications (COMMS)
+
+Depending on an operator's logical management overlay network design, general management communications (COMMS) may also be transported within the OSC. Therefore, the OSC for some applications may also transport general management communications. General management communications may include signalling, voice/voiceband communications, software download, operator-specific communications, etc.
+
+### OTN synchronisation message channel (OSMC)
+
+For synchronisation purposes, the OSC OSMC signal is defined as an OTN synchronisation message channel to transport SSM and PTP messages.
+
+NOTE 1 – Support of OSC OSMC is optional.
+
+NOTE 2 – Equipment designed prior to Edition 4.6 of this recommendation may not be able to support OSC OSMC.
+
+## 14.2 OCC
+
+The overhead information carried over the OCC consists of the OCh-O or OTSiG-O. The information content of this overhead is defined in clause 15. The format, structure and bit rate of this overhead is defined in [ITU-T G.7712].
+
+### 14.2.1 OCh-O transport over OTN optical networking interface, type II
+
+For an OTN optical networking interface, type II, the OCh-O is transferred over the overhead communication network (OCN) as described in [ITU-T G.7712].
+
+NOTE – An OTN optical networking interface which transfers OCh-O over an OCN cannot provide fate-sharing of the OCh-O with the OTSiG across this interface.
+
+The OCh FDI-P, FDI-O and OCI Overhead primitives are communicated over the OCN. The specification of the encapsulation, identification and transmission of this information is outside the scope of this Recommendation and specified in [ITU-T G.7712]. This information must be communicated with the peers such that the OCh-O primitives come into sync within one second in the absence of changes to OCh FDI-P, FDI-O or OCI. In the event of changes to any OCh-O primitive, the update must be sent within 10 ms of the change and with a mechanism to guarantee receipt in the event of packet loss.
+
+### 14.2.2 OTSiG-O transport over OTN optical networking interface, type II
+
+For an OTN optical networking interface, type II, the OTSiG-O is transferred over the overhead communication network (OCN) as described in [ITU-T G.7712].
+
+NOTE – An OTN optical networking interface which transfers OTSiG-O over an OCN cannot provide fate-sharing of the OTSiG-O with the OTSiG across this interface.
+
+The OTSiG-O FDI-P, FDI-O, OCI, TTI, BDI-P, BDI-O and TSI Overhead primitives are communicated over the OCN. The specification of the encapsulation, identification and transmission of this information is outside the scope of this Recommendation and specified in [ITU-T G.7712]. This information must be communicated with the peers such that the OTSiG-O primitives come into sync within one second in the absence of changes to OTSiG FDI-P, FDI-O, OCI, TTI, BDI-P, BDI-O
+
+or TSI. In the event of changes to any OTSiG-O primitive, the update must be sent within 10 ms of the change and with a mechanism to guarantee receipt in the event of packet loss.
+
+# 15 Overhead description
+
+An overview of OTS-O, OMS-O, OCh-O and OTSiG-O information carried within the OSC is presented in Figure 15-1. An overview of OCh-O information carried within the OCC is presented in Figure 15-2.
+
+![Figure 15-1: Hierarchical diagram of OSC payload structure showing OTS-O, OMS-O, OCh-O, and OTSiG-O overheads.](40a8c30f7ea5ecea4912e040c97c5b9c_img.jpg)
+
+The diagram illustrates the hierarchical structure of the OSC payload. At the top level, the OSC payload contains OSMC and COMMS. Below this, the OTS-O payload contains TTI, BDI-O, BDI-P, and PMI. The next level shows the OMS-O payload, which includes MSI, FDI-O, FDI-P, BDI-O, BDI-P, and PMI. The innermost level displays multiple OCh-O payloads (labeled OCh-O #1, OCh-O #2, ..., OCh-O #n), each containing FDI-O, FDI-P, and OCI. To the right, multiple OTSiG-O payloads (labeled OTSiG-O #1, OTSiG-O #2, ..., OTSiG-O #m) are shown, each containing TSI (\*), TTI (\*), BDI-O (\*), BDI-P (\*), FDI-O, FDI-P, and OCI.
+
+G.709-Y.1331(20)\_F15-1
+
+(\*) This overhead may be carried over the OSC or over a communication channel modulated on one or more OTSi within the OTSiG.
+
+Figure 15-1: Hierarchical diagram of OSC payload structure showing OTS-O, OMS-O, OCh-O, and OTSiG-O overheads.
+
+**Figure 15-1 – OTS-O, OMS-O, OCh-O and OTSiG-O information carried within the OSC**
+
+![Figure 15-2: Diagram of OCh-O information carried within the OCC.](aeb2a26a07219661191294dba528067a_img.jpg)
+
+The diagram shows the OCh-O information structure within the OCC. It consists of a box labeled OCh-O containing three stacked sub-boxes: FDI-O, FDI-P, and OCI.
+
+G.709-Y.1331(16)\_F15-2
+
+Figure 15-2: Diagram of OCh-O information carried within the OCC.
+
+**Figure 15-2 – OCh-O information carried within the OCC**
+
+An overview of OTUk, ODUk and OPUk overhead is presented in Figures 15-3A and 15-5. An overview of OTUCn, ODUCn and OPUCn overhead is presented in Figures 15-4 and 15-6. An overview of OTU25 and OTU50 overhead is presented in Figure 15-3B. It is the same as OTUk overhead.
+
+![](4162c218fc7881cd90fc9574e07d2327_img.jpg)
+
+**Column**  
+Row 1 7 8 14 15 3824 3825 4080
+
+|   |       |         |  |                             |
+|---|-------|---------|--|-----------------------------|
+| 1 | FA OH | OTUk OH |  | OTUk FEC<br>(4 × 256 bytes) |
+| 2 |       |         |  |                             |
+| 3 |       |         |  |                             |
+| 4 |       |         |  |                             |
+
+**Column #**
+
+|          |     |   |   |   |   |   |      |    |   |    |      |      |     |    |
+|----------|-----|---|---|---|---|---|------|----|---|----|------|------|-----|----|
+| <i>1</i> | 1   | 2 | 3 | 4 | 5 | 6 | 7    | 8  | 9 | 10 | 11   | 12   | 13  | 14 |
+| <i>1</i> | FAS |   |   |   |   |   | MFAS | SM |   |    | GCC0 | OSMC | RES |    |
+
+**SM**
+
+| 1   | 2     | 3 |
+|-----|-------|---|
+| TTI | BIP-8 |   |
+
+|               |                   |
+|---------------|-------------------|
+| 0<br>:<br>15  | SAPI              |
+| 16<br>:<br>31 | DAPI              |
+| 32<br>:<br>63 | Operator specific |
+
+|          |   |   |   |     |     |     |   |
+|----------|---|---|---|-----|-----|-----|---|
+| 1        | 2 | 3 | 4 | 5   | 6   | 7   | 8 |
+| BEI/BIAE |   |   |   | BDI | IAE | RES |   |
+
+|                                          |                                                       |
+|------------------------------------------|-------------------------------------------------------|
+| BDI Backward defect indication           | GCC General communication channel                     |
+| BEI Backward error indication            | IAE Incoming alignment error                          |
+| BIAE Backward incoming alignment error   | MFAS Multiframe alignment signal                      |
+| BIP8 Bit interleaved parity – level 8    | OSMC OTN synchronization message channel              |
+| DAPI Destination access point identifier | RES Reserved for future international standardization |
+| FA Frame alignment                       | SAPI Source access point identifier                   |
+| FAS Frame alignment signal               | SM Section monitoring                                 |
+|                                          | TTI Trail trace identifier                            |
+
+G.709-Y.1331(20)\_F15-3A
+
+Figure 15-3A – OTUk frame structure, frame alignment and OTUk overhead
+
+![](789ee0a267b24f34bd1f45313e86c9a4_img.jpg)
+
+**Column**  
+Row 1 7 8 14 15 3824
+
+|   |       |         |  |
+|---|-------|---------|--|
+| 1 | FA OH | OTUk OH |  |
+| 2 |       |         |  |
+| 3 |       |         |  |
+| 4 |       |         |  |
+
+**Column #**
+
+|          |     |   |   |   |   |   |      |    |   |    |      |      |     |    |
+|----------|-----|---|---|---|---|---|------|----|---|----|------|------|-----|----|
+| <i>1</i> | 1   | 2 | 3 | 4 | 5 | 6 | 7    | 8  | 9 | 10 | 11   | 12   | 13  | 14 |
+| <i>1</i> | FAS |   |   |   |   |   | MFAS | SM |   |    | GCC0 | OSMC | RES |    |
+
+**SM**
+
+| 1   | 2     | 3 |
+|-----|-------|---|
+| TTI | BIP-8 |   |
+
+|               |                   |
+|---------------|-------------------|
+| 0<br>:<br>15  | SAPI              |
+| 16<br>:<br>31 | DAPI              |
+| 32<br>:<br>63 | Operator specific |
+
+|          |   |   |   |     |     |     |   |
+|----------|---|---|---|-----|-----|-----|---|
+| 1        | 2 | 3 | 4 | 5   | 6   | 7   | 8 |
+| BEI/BIAE |   |   |   | BDI | IAE | RES |   |
+
+|                                          |                                                       |
+|------------------------------------------|-------------------------------------------------------|
+| BDI Backward defect indication           | GCC General communication channel                     |
+| BEI Backward error indication            | IAE Incoming alignment error                          |
+| BIAE Backward incoming alignment error   | MFAS Multiframe alignment signal                      |
+| BIP8 Bit interleaved parity – level 8    | OSMC OTN synchronization message channel              |
+| DAPI Destination access point identifier | RES Reserved for future international standardization |
+| FA Frame alignment                       | SAPI Source access point identifier                   |
+| FAS Frame alignment signal               | SM Section monitoring                                 |
+|                                          | TTI Trail trace identifier                            |
+
+G.709-Y.1331(20)\_F15-3B
+
+Figure 15-3B – OTU25 and OTU50 frame structure, frame alignment and OTU overhead
+
+![](701bc79e78b382bcfd3ba85597dbb9c3_img.jpg)
+
+**Column**  
+Row 1 1 ... 7 8 ... 14 15 ... 3824
+
+|   |              |               |  |
+|---|--------------|---------------|--|
+| 1 | <b>FA OH</b> | <b>OTU OH</b> |  |
+| 2 |              |               |  |
+| 3 |              |               |  |
+| 4 |              |               |  |
+
+**Column #**
+
+|          |          |          |          |          |          |          |          |          |          |           |           |           |           |           |                          |
+|----------|----------|----------|----------|----------|----------|----------|----------|----------|----------|-----------|-----------|-----------|-----------|-----------|--------------------------|
+|          | <i>1</i> | <i>2</i> | <i>3</i> | <i>4</i> | <i>5</i> | <i>6</i> | <i>7</i> | <i>8</i> | <i>9</i> | <i>10</i> | <i>11</i> | <i>12</i> | <i>13</i> | <i>14</i> | <b>OTUC #1<br/>to #n</b> |
+| <i>1</i> | FAS      |          |          |          |          |          | MFAS     | SM       |          |           | GCC0      |           | RES       |           |                          |
+
+**SM#1**
+
+|     |       |   |
+|-----|-------|---|
+| 1   | 2     | 3 |
+| TTI | BIP-8 |   |
+
+|    |                      |
+|----|----------------------|
+| 0  | SAPI                 |
+| :  |                      |
+| 15 |                      |
+| 16 | DAPI                 |
+| :  |                      |
+| 31 |                      |
+| 32 | Operator<br>specific |
+| :  |                      |
+| 63 |                      |
+
+|          |          |          |          |          |          |          |          |
+|----------|----------|----------|----------|----------|----------|----------|----------|
+| <i>1</i> | <i>2</i> | <i>3</i> | <i>4</i> | <i>5</i> | <i>6</i> | <i>7</i> | <i>8</i> |
+| BEI/BIAE |          |          |          | BDI      | STAT     |          |          |
+
+**SM #2 to #n**
+
+|     |       |   |
+|-----|-------|---|
+| 1   | 2     | 3 |
+| RES | BIP-8 |   |
+
+|          |          |          |          |          |          |          |          |
+|----------|----------|----------|----------|----------|----------|----------|----------|
+| <i>1</i> | <i>2</i> | <i>3</i> | <i>4</i> | <i>5</i> | <i>6</i> | <i>7</i> | <i>8</i> |
+| BEI/BIAE |          |          |          | RES      |          |          |          |
+
+G.709-Y.1331(16)-Amd.1(16)\_F15-4
+
+- BDI Backward defect indication
+- BEI Backward error indication
+- BIAE Backward incoming alignment error
+- BIP8 Bit interleaved parity – level 8
+- DAPI Destination access point identifier
+- FA Frame alignment
+- FAS Frame alignment signal
+
+- GCC General communication channel
+- STAT Status
+- MFAS Multiframe alignment signal
+- OSMC OTN synchronization message channel
+- RES Reserved for future international standardization
+- SAPI Source access point identifier
+- SM Section monitoring
+- TTI Trail trace identifier
+
+**Figure 15-4 – OTUCn frame structure, frame alignment and OTUCn overhead**
+
+![Diagram of ODUk frame structure showing the overall frame layout, detailed overhead sections (OTUk, ODUk, OPUk), and a list of field abbreviations.](89f8aefc01866631793087542316cef2_img.jpg)
+
+**Column**  
+Row 1 ..... 14 15 16 17 ..... 3824
+
+**Row**  
+1  
+2  
+3  
+4
+
+**ODUk overhead** (Rows 1-4, Columns 1-14)  
+**OPUk overhead** (Rows 1-4, Columns 15-17)  
+**OPUk payload (4 × 3808 bytes)** (Rows 1-4, Columns 18-3824)  
+BIP8 parity block
+
+**Column #**  
+1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
+
+**Row #**  
+1 Frame alignment overhead OTUk overhead  
+2 RES PM and TCM EXP TCM6 TCM5 TCM4 EXP  
+3 TCM3 TCM2 TCM1 PM EXP  
+4 GCC1 GCC2 APS/PCC RES
+
+**OPUk overhead**
+
+**PM and TCMi (i = 1..6)**
+
+| 1   | 2     | 3 |
+|-----|-------|---|
+| TTI | BIP-8 |   |
+
+0  
+⋮  
+15 SAPI  
+16 DAPI  
+⋮  
+31  
+32 Operator specific  
+⋮  
+63
+
+**PM**
+
+| 1   | 2 | 3   | 4    | 5 | 6 | 7 | 8 |
+|-----|---|-----|------|---|---|---|---|
+| BEI |   | BDI | STAT |   |   |   |   |
+
+**TCMi**
+
+| 1        | 2 | 3   | 4    | 5 | 6 | 7 | 8 |
+|----------|---|-----|------|---|---|---|---|
+| BEI/BIAE |   | BDI | STAT |   |   |   |   |
+
+**PM and TCM**
+
+| 1    | 2    | 3    | 4    | 5    | 6    | 7   | 8   |
+|------|------|------|------|------|------|-----|-----|
+| DMt1 | DMt2 | DMt3 | DMt4 | DMt5 | DMt6 | DMp | RES |
+
+**OPUk OH**
+
+| 15 | 16                                 |
+|----|------------------------------------|
+| 1  | Mapping and concatenation specific |
+| 2  |                                    |
+| 3  |                                    |
+| 4  | PSI                                |
+
+0  
+1  
+⋮  
+255
+
+**PT**
+
+|                                    |
+|------------------------------------|
+| Mapping and concatenation specific |
+|------------------------------------|
+
+**Legend:**
+
+- PM Path monitoring
+- TCM Tandem connection monitoring
+- PM and Path monitoring and
+- TCM Tandem connection monitoring
+- SAPI Source access point identifier
+- DAPI Destination access point identifier
+- RES Reserved for future international standardization
+- EXP Experimental
+- GCC General communication channel
+- APS Automatic protection switching coordination channel
+- PCC Protection communication control channel
+- BIAE Backward incoming alignment error
+- TTI Trail trace identifier
+- BIP8 Bit interleaved parity - level 8
+- BEI Backward error indication
+- BDI Backward defect indication
+- STAT Status
+- PSI Payload structure identifier
+- PT Payload type
+- DM Delay measurement
+
+G.709-Y.1331(16)\_F15-5
+
+Diagram of ODUk frame structure showing the overall frame layout, detailed overhead sections (OTUk, ODUk, OPUk), and a list of field abbreviations.
+
+Figure 15-5 – ODUk frame structure, ODUk and OPUk overhead
+
+![Figure 15-6 – ODUCn frame structure, ODUCn and OPUCn overhead. The diagram shows the hierarchical structure of an ODUCn frame, starting with the overall frame layout (rows 1-4, columns 1-3824) and zooming into the overhead sections. The OPU overhead (OPU OH) is shown in columns 15 and 16 of row 1, containing mapping and concatenation specific information and the PSI. The ODU overhead (ODU OH) is shown in rows 2-4, columns 1-16, containing frame alignment overhead, OTUk overhead, and various monitoring and control fields (RES, EXP, TCM, PM, GCC). Further zooms show the internal structure of the PM and TCM overheads, including TTI, BIP-8, BEI, BDI, and STAT fields. A legend on the left defines the abbreviations used.](a2251e3bbfcd726b68cc50b091e53b02_img.jpg)
+
+**Column**  
+Row 1 ..... 14 15 16 17 ..... 3824
+
+**Row**  
+1  
+2  
+3  
+4
+
+**ODU overhead**  
+**OPU overhead**  
+**OPU payload** (4 × 3808 bytes)  
+BIP8 parity block
+
+**Column #**  
+1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
+
+**Row #**  
+1  
+2  
+3  
+4
+
+Frame alignment overhead  
+OTUk overhead  
+OPUk overhead
+
+RES EXP TCM6 TCM5 TCM4 EXP  
+TCM3 TCM2 TCM1 PM EXP  
+GCC1 GCC2 RES
+
+**OPU OH**  
+15 16  
+1 Mapping and concatenation specific  
+2  
+3  
+4 PSI
+
+PM and TCM APS/PCC ODU #1 in ODuk and ODUCn  
+RES RES ODU #2 to #n in ODUCn
+
+PT ODU #1 in ODuk and ODUCn  
+RES ODU #2 to #n in ODUCn
+
+Mapping and concatenation specific  
+0  
+1  
+255
+
+**PM and TCMi (i = 1..6),  
+PM #1 and TCMi #1**
+
+|     |       |   |
+|-----|-------|---|
+| 1   | 2     | 3 |
+| TTI | BIP-8 |   |
+
+0  
+SAPI  
+15  
+DAPI  
+16  
+Operator specific  
+31  
+32  
+63
+
+1 2 3 4 5 6 7 8  
+BEI BDI STAT  
+1 2 3 4 5 6 7 8  
+BEI/BIAE BDI STAT
+
+**PM #2 to #n and TCMi #2 to #n**
+
+|     |       |   |
+|-----|-------|---|
+| 1   | 2     | 3 |
+| RES | BIP-8 |   |
+
+1 2 3 4 5 6 7 8  
+BEI RES  
+1 2 3 4 5 6 7 8  
+BEI/BIAE RES
+
+**PM and TCM**
+
+|     |     |     |     |     |     |     |     |
+|-----|-----|-----|-----|-----|-----|-----|-----|
+| 1   | 2   | 3   | 4   | 5   | 6   | 7   | 8   |
+| DM1 | DM2 | DM3 | DM4 | DM5 | DM6 | DMp | RES |
+
+G.709-Y.1331(16)\_F15-6
+
+PM Path monitoring  
+TCM Tandem connection monitoring  
+PM and Path monitoring and  
+TCM Tandem connection monitoring  
+SAPI Source access point identifier  
+DAPI Destination access point identifier  
+RES Reserved for future international standardization  
+EXP Experimental  
+GCC General communication channel  
+APS Automatic protection switching coordination channel  
+PCC Protection communication control channel  
+BIAE Backward incoming alignment error  
+TTI Trail trace identifier  
+BIP8 Bit interleaved parity - level 8  
+BEI Backward error indication  
+BDI Backward defect indication  
+STAT Status  
+PSI Payload structure identifier  
+PT Payload type  
+DM Delay measurement
+
+Figure 15-6 – ODUCn frame structure, ODUCn and OPUCn overhead. The diagram shows the hierarchical structure of an ODUCn frame, starting with the overall frame layout (rows 1-4, columns 1-3824) and zooming into the overhead sections. The OPU overhead (OPU OH) is shown in columns 15 and 16 of row 1, containing mapping and concatenation specific information and the PSI. The ODU overhead (ODU OH) is shown in rows 2-4, columns 1-16, containing frame alignment overhead, OTUk overhead, and various monitoring and control fields (RES, EXP, TCM, PM, GCC). Further zooms show the internal structure of the PM and TCM overheads, including TTI, BIP-8, BEI, BDI, and STAT fields. A legend on the left defines the abbreviations used.
+
+Figure 15-6 – ODUCn frame structure, ODUCn and OPUCn overhead
+
+## 15.1 Types of overhead
+
+### 15.1.1 Optical payload unit overhead (OPU OH)
+
+OPU OH information is added to the OPU information payload to create an OPU. It includes information to support the adaptation of client signals. The OPU OH is terminated where the OPU is assembled and disassembled. The specific OH format and coding is defined in clause 15.9.
+
+### 15.1.2 Optical data unit overhead (ODU OH)
+
+ODU OH information is added to the ODU information payload to create an ODU. It includes information for maintenance and operational functions to support ODU connections. The ODU OH consists of portions dedicated to the end-to-end ODU path and to six levels of tandem connection monitoring. The ODU path OH is terminated where the ODU is assembled and disassembled. The TC OH is added and terminated at the source and sink of the corresponding tandem connections, respectively. The specific OH format and coding is defined in clauses 15.6 and 15.8.
+
+### **15.1.3 Optical transport unit overhead (OTU OH)**
+
+OTU OH information is added to the OTU information payload to create an OTU. It includes information for maintenance and operational functions to support OTU connections. The OTU OH is terminated where the OTU signal is assembled and disassembled. The specific OH format and coding is defined in clauses 15.6 and 15.7.
+
+The specific frame structure and coding for the non-standard OTUkV OH is outside the scope of this Recommendation. Only the required basic functionality that has to be supported is defined in clause 15.7.3.
+
+### **15.1.4 OCh-O**
+
+OCh-O is the non-associated overhead information that accompanies an OTSiG. It includes information for maintenance functions to support fault management. The OCh-O is generated or modified at intermediate points along the OCh trail. All information elements of the OCh-O are terminated where the OTSiG signal is terminated.
+
+The OCh-O information is defined in clause 15.5.
+
+### **15.1.5 OMS-O**
+
+OMS-O is the non-associated overhead information that accompanies an OMS OSME. It includes information for maintenance and operational functions to support optical multiplex sections. The OMS-O is generated or modified at intermediate points along the OMS OSME and OMS-O trail and generated and terminated at the endpoints of the OMS OSME where the OMS-O trail is terminated.
+
+OMS-O information elements other than OMS FDI-P and FDI-O are generated and terminated at the ends of the OMS-O trail. OMS FDI-P and FDI-O are generated at intermediate points along the OMS-O trail and terminated at the ends of the OMS-O trail.
+
+The OMS-O information is defined in clause 15.4.
+
+### **15.1.6 OTS-O**
+
+OTS-O is the non-associated overhead information that accompanies an OTS OSME. It includes information for maintenance and operational functions to support optical transmission sections. The OTS-O is terminated at the endpoints of the OTS OSME where the OTS-O trail is terminated.
+
+The OTS-O information is defined in clause 15.3.
+
+### **15.1.7 General management communications overhead (COMMS OH)**
+
+COMMS OH information provides general management communication between network elements. The specific frame structure and coding for the COMMS OH is outside the scope of this Recommendation.
+
+### **15.1.8 OTSiG-O**
+
+OTSiG-O is the non-associated overhead information that accompanies an OTSiG. It includes information for maintenance functions to support fault management. The OTSiG-O TSI, TTI, BDI-P and BDI-O are generated where the OTSiA signal is assembled and the OCI, FDI-P and FDI-O are modified or generated at intermediate points along the OTSiA trail. All information elements of the OTSiG-O are terminated where the OTSiA is disassembled.
+
+The OTSiG-O information is defined in clause 15.5.
+
+NOTE – OSC signals designed prior to Edition 5 of this recommendation may only be able to transport a subset of the OTSiG-O (possibly excluding TSI, TTI, BDI-P and BDI-O) overhead.
+
+## 15.2 Trail trace identifier and access point identifier definition
+
+A trail trace identifier (TTI) is defined as a 64-byte string with the following structure (see Figure 15-7):
+
+- TTI[0] contains the SAPI[0] character, which is fixed to all-0s.
+- TTI[1] to TTI[15] contain the 15-character source access point identifier (SAPI[1] to SAPI[15]).
+- TTI[16] contains the DAPI[0] character, which is fixed to all-0s.
+- TTI[17] to TTI[31] contain the 15-character destination access point identifier (DAPI[1] to DAPI[15]).
+- TTI[32] to TTI[63] are operator specific.
+
+![Figure 15-7 – TTI structure diagram showing the byte layout of a 64-byte Trail Trace Identifier (TTI).](3337af75dfee8af7687b4f49914d6c93_img.jpg)
+
+The diagram illustrates the structure of a 64-byte Trail Trace Identifier (TTI). It is organized into 8 columns (bytes 1-8) and 64 rows (bytes 0-63). The first byte (row 0) is SAPI[0]. Bytes 1 through 15 (rows 1-15) form the Source Access Point Identifier (SAPI), with SAPI[1] at row 1, SAPI[2] at row 2, and SAPI[15] at row 15. Bytes 16 through 31 (rows 16-31) form the Destination Access Point Identifier (DAPI), with DAPI[0] at row 16, DAPI[1] at row 17, DAPI[2] at row 18, and DAPI[15] at row 31. Bytes 32 through 63 (rows 32-63) are Operator specific. The diagram also includes labels for 'Source access point identifier' and 'Destination access point identifier' on the right side, and a reference code 'G.709-Y.1331(16)\_F15-7' at the bottom right.
+
+|    | 1                 | 2        | 3 | 4 | 5 | 6 | 7 | 8 |  |                                       |                                            |
+|----|-------------------|----------|---|---|---|---|---|---|--|---------------------------------------|--------------------------------------------|
+| 0  | SAPI[0]           |          |   |   |   |   |   |   |  |                                       |                                            |
+| 1  | 0                 | SAPI[1]  |   |   |   |   |   |   |  | <i>Source access point identifier</i> |                                            |
+| 2  | 0                 | SAPI[2]  |   |   |   |   |   |   |  |                                       |                                            |
+| ⋮  |                   | ⋮        |   |   |   |   |   |   |  |                                       |                                            |
+| 15 | 0                 | SAPI[15] |   |   |   |   |   |   |  |                                       |                                            |
+| 16 | DAPI[0]           |          |   |   |   |   |   |   |  |                                       |                                            |
+| 17 | 0                 | DAPI[1]  |   |   |   |   |   |   |  |                                       | <i>Destination access point identifier</i> |
+| 18 | 0                 | DAPI[2]  |   |   |   |   |   |   |  |                                       |                                            |
+| ⋮  |                   | ⋮        |   |   |   |   |   |   |  |                                       |                                            |
+| 31 | 0                 | DAPI[15] |   |   |   |   |   |   |  |                                       |                                            |
+| 32 | Operator specific |          |   |   |   |   |   |   |  |                                       |                                            |
+| ⋮  |                   |          |   |   |   |   |   |   |  |                                       |                                            |
+| 63 |                   |          |   |   |   |   |   |   |  |                                       |                                            |
+
+Figure 15-7 – TTI structure diagram showing the byte layout of a 64-byte Trail Trace Identifier (TTI).
+
+Figure 15-7 – TTI structure
+
+The features of access point identifiers (APIs) are:
+
+- Each access point identifier must be globally unique in its layer network.
+- Where it may be expected that the access point may be required for path set-up across an inter-operator boundary, the access point identifier must be available to other network operators.
+- The access point identifier should not change while the access point remains in existence.
+- The access point identifier should be able to identify the country and network operator which is responsible for routing to and from the access point.
+- The set of all access point identifiers belonging to a single administrative layer network should form a single access point identification scheme.
+- The scheme of access point identifiers for each administrative layer network can be independent from the scheme in any other administrative layer network.
+
+It is recommended that the ODUk, OTUk and OTS should each have the access point identification scheme based on a tree-like format to aid routing control search algorithms. The access point identifier should be globally unambiguous.
+
+The access point identifier (SAPI, DAPI) shall consist of a three-character international segment and a twelve-character national segment (NS) (see Figure 15-8). These characters shall be coded according to [ITU-T T.50] (International Reference Alphabet – 7-bit coded character set for information exchange).
+
+| IS character # |   |   | NS character # |      |      |      |      |      |      |    |    |    |    |    |
+|----------------|---|---|----------------|------|------|------|------|------|------|----|----|----|----|----|
+| 1              | 2 | 3 | 4              | 5    | 6    | 7    | 8    | 9    | 10   | 11 | 12 | 13 | 14 | 15 |
+| CC             |   |   | ICC            | UAPC |      |      |      |      |      |    |    |    |    |    |
+| CC             |   |   | ICC            |      | UAPC |      |      |      |      |    |    |    |    |    |
+| CC             |   |   | ICC            |      |      | UAPC |      |      |      |    |    |    |    |    |
+| CC             |   |   | ICC            |      |      |      | UAPC |      |      |    |    |    |    |    |
+| CC             |   |   | ICC            |      |      |      |      | UAPC |      |    |    |    |    |    |
+| CC             |   |   | ICC            |      |      |      |      |      | UAPC |    |    |    |    |    |
+
+**Figure 15-8 – Access point identifier structure**
+
+The international segment field provides a three-character ISO 3166 geographic/political country code (G/PCC). The country code shall be based on the three-character uppercase alphabetic ISO 3166 country code (e.g., USA, FRA).
+
+The national segment field consists of two subfields: the ITU carrier code (ICC) followed by a unique access point code (UAPC).
+
+The ITU carrier code is a code assigned to a network operator/service provider, maintained by the ITU-T Telecommunication Standardization Bureau (TSB) as per [ITU-T M.1400]. This code shall consist of 1-6 left-justified characters, alphabetic, or leading alphabetic with trailing numeric.
+
+The unique access point code shall be a matter for the organization to which the country code and ITU carrier code have been assigned, provided that uniqueness is guaranteed. This code shall consist of 6-11 characters, with trailing NUL, completing the 12-character national segment.
+
+## 15.3 OTS-O description
+
+The following OTS-O information elements are defined:
+
+- OTS-TTI
+- OTS-BDI-P
+- OTS-BDI-O
+- OTS-PMI
+
+### 15.3.1 OTS trail trace identifier (TTI)
+
+The OTS-TTI is defined to transport a 64-byte TTI as specified in clause 15.2 for OTS connectivity monitoring.
+
+### 15.3.2 OTS backward defect indication – Payload (BDI-P)
+
+For OTS OSME and OTS-O trail monitoring, the OTS-BDI-P signal is defined to convey in the upstream direction the OTS OSME and OTS-O trail signal fail status detected in the sink point of the OTS OSME and OTS-O trail termination sink function.
+
+### **15.3.3 OTS backward defect indication – Overhead (BDI-O)**
+
+For OTS-O trail monitoring, the OTS-BDI-O signal is defined to convey in the upstream direction the OTS-O signal fail status detected in the OTS-O trail termination sink function.
+
+### **15.3.4 OTS payload missing indication (PMI)**
+
+The OTS PMI is a signal sent downstream as an indication that upstream at the source point of the OTS OSME no optical signal is present, in order to suppress the report of the consequential loss of signal condition at the sink point of the OTS OSME.
+
+## **15.4 OMS-O description**
+
+The following OMS-O information elements are defined:
+
+- OMS-FDI-P
+- OMS-FDI-O
+- OMS-BDI-P
+- OMS-BDI-O
+- OMS-PMI
+- OMS-MSI
+
+### **15.4.1 OMS forward defect indication – Payload (FDI-P)**
+
+For OMS OSME and OMS-O trail monitoring, the OMS-FDI-P signal is defined to convey in the downstream direction the signal status (normal or failed).
+
+### **15.4.2 OMS forward defect indication – Overhead (FDI-O)**
+
+For OMS-O trail monitoring, the OMS-FDI-O signal is defined to convey in the downstream direction the OMS-O signal status (normal or failed).
+
+### **15.4.3 OMS backward defect indication – Payload (BDI-P)**
+
+For OMS OSME and OMS-O trail monitoring, the OMS-BDI-P signal is defined to convey in the upstream direction the OMS-P signal fail status detected in the sink point of the OMS OSME and OMS-O trail termination sink function.
+
+### **15.4.4 OMS backward defect indication – Overhead (BDI-O)**
+
+For OMS-O trail monitoring, the OMS-BDI-O signal is defined to convey in the upstream direction the OMS-O signal fail status detected in the OMS-O trail termination sink function.
+
+### **15.4.5 OMS payload missing indication (PMI)**
+
+The OMS PMI is a signal sent downstream as an indication that upstream at the source point of the OMS OSME none of the frequency slots contain an optical tributary signal, in order to suppress the report of the consequential loss of signal condition at the sink point of the OMS OSME.
+
+### **15.4.6 OMS multiplex structure identifier (MSI)**
+
+The OMS multiplex structure identifier (MSI) signal encodes the OTSiG multiplex structure and occupied frequency slots in the OMS OSME at the source end point. It is sent downstream to enable detection of OTSiG multiplex structure configuration mismatches between sink and source end points.
+
+The OMS multiplex structure identifier (MSI) signal also encodes the media channel structure which is independent of the OTSiG in the OMS OSME at the source and sink end points. It is sent downstream to enable detection of media channel structure configuration mismatches between sink and source end points.
+
+The OMS MSI is defined for flex grid OTN optical networking interfaces, type I. Fixed grid OTN optical networking interfaces may not support the OMS MSI. Flex grid OTN optical networking interfaces, type I designed prior to Edition 5.0 of this Recommendation may not support the OMS MSI.
+
+## **15.5 OCh-O and OTSiG-O description**
+
+The following OCh-O and OTSiG-O information elements are defined:
+
+- OCh-FDI-P and OTSiA-FDI-P
+- OCh-FDI-O and OTSiA-FDI-O
+- OCh-OCI and OTSiA-OCI
+- OTSiA-BDI-P
+- OTSiA-BDI-O
+- OTSiA-TTI
+- OTSiG-TSI
+
+### **15.5.1 OCh and OTSiA forward defect indication – Payload (FDI-P)**
+
+For OCh and OTSiA trail monitoring, the OCh-FDI-P or OTSiA-FDI-P signal is defined to convey in the downstream direction the OTSiG signal status (normal or failed).
+
+### **15.5.2 OCh and OTSiA forward defect indication – Overhead (FDI-O)**
+
+For OCh and OTSiA trail monitoring, the OCh-FDI-O or OTSiA-FDI-O signal is defined to convey in the downstream direction the OCh-O or OTSiG-O overhead signal status (normal or failed).
+
+### **15.5.3 OCh and OTSiA open connection indication (OCI)**
+
+The OCh and OTSiA OCI is a signal sent downstream as an indication that upstream in a connection function the OCh (i.e., OTSiG and OCh-O) or OTSiA (i.e., OTSiG and OTSiG-O) matrix connection is opened as a result of a management command. The consequential detection of the OCh or OTSiA loss of signal condition at the OCh or OTSiA termination point can now be related to an open matrix.
+
+### **15.5.4 Blank clause**
+
+*This clause is intentionally left blank.*
+
+### **15.5.5 OTSiA backward defect indication – Payload (BDI-P)**
+
+For OTSiA path monitoring, the OTSiA-BDI-P signal is defined to convey in the upstream direction the OTSiG signal fail status detected in the OTSiG termination sink function.
+
+### **15.5.6 OTSiA backward defect indication – Overhead (BDI-O)**
+
+For OTSiA path monitoring, the OTSiA-BDI-O signal is defined to convey in the upstream direction the OTSiG-O signal fail status detected in the OTSiG-O termination sink function.
+
+### **15.5.7 OTSiA trail trace identifier (TTI)**
+
+The OTSiA-TTI is defined to transport a 64-byte TTI as specified in clause 15.2 for OTSiA path monitoring.
+
+### **15.5.8 OTSiG transmitter structure identifier (TSI)**
+
+The OTSiG-TSI is defined to transport a TSI for monitoring consistent configuration of the OTSiG transmitter(s) at source end points and OTSiG receiver(s) at sink end points.
+
+## 15.6 OTU/ODU frame alignment OH description
+
+### 15.6.1 OTU/ODU frame alignment overhead location
+
+The OTU/ODU frame alignment overhead location is shown in Figure 15-9. The OTU/ODU frame alignment overhead is applicable for both the OTU and ODU signals.
+
+The OTUk/ODUk, OTU25/ODU25 and OTU50/ODU50 contain one instance of OTU/ODU frame alignment overhead. The OTUCn/ODUCn contains n instances of OTU/ODU frame alignment overhead, numbered 1 to n.
+
+![Figure 15-9: OTU/ODU frame alignment overhead location diagram. It shows a grid with 16 columns and 4 rows. Row 1 contains FAS (columns 1-6), MFAS (column 7), and OTU overhead (columns 8-14). Rows 2-4 contain ODU overhead (columns 1-14). Column 15 is labeled OPU overhead.](212c50c4e3d043c989037a01e13c1a98_img.jpg)
+
+Figure 15-9 is a diagram illustrating the location of OTU/ODU frame alignment overhead within a frame structure. The frame is represented as a grid with 16 columns (Column # 1 to 16) and 4 rows (Row # 1 to 4). Row 1 contains the FAS (Frame Alignment Signal) in columns 1-6, MFAS (Multi-Frame Alignment Signal) in column 7, and OTU overhead in columns 8-14. Rows 2, 3, and 4 contain the ODU overhead in columns 1-14. Column 15 is labeled OPU overhead. The diagram is labeled G.709-Y.1331(16)\_F15-9.
+
+Figure 15-9: OTU/ODU frame alignment overhead location diagram. It shows a grid with 16 columns and 4 rows. Row 1 contains FAS (columns 1-6), MFAS (column 7), and OTU overhead (columns 8-14). Rows 2-4 contain ODU overhead (columns 1-14). Column 15 is labeled OPU overhead.
+
+Figure 15-9 – OTU/ODU frame alignment overhead
+
+### 15.6.2 OTU/ODU frame alignment overhead definition
+
+#### 15.6.2.1 Frame alignment signal (FAS)
+
+A six byte OTU-FAS signal (see Figure 15-10) is defined in row 1, columns 1 to 6 of the OTU overhead. OA1 is "1111 0110". OA2 is "0010 1000".
+
+The OTUk, OTU25 and OTU50 contain one instance of OTU multi-frame alignment overhead. The OTUCn contains n instances of OTU multi-frame alignment overhead, numbered 1 to n.
+
+| FAS OH byte 1 |   |   |   |   |   |   |   | FAS OH byte 2 |   |   |   |   |   |   |   | FAS OH byte 3 |   |   |   |   |   |   |   | FAS OH byte 4 |   |   |   |   |   |   |   | FAS OH byte 5 |   |   |   |   |   |   |   | FAS OH byte 6 |   |   |   |   |   |   |   |
+|---------------|---|---|---|---|---|---|---|---------------|---|---|---|---|---|---|---|---------------|---|---|---|---|---|---|---|---------------|---|---|---|---|---|---|---|---------------|---|---|---|---|---|---|---|---------------|---|---|---|---|---|---|---|
+| 1             | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 1             | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 1             | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 1             | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 1             | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 1             | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
+| OA1           |   |   |   |   |   |   |   | OA1           |   |   |   |   |   |   |   | OA1           |   |   |   |   |   |   |   | OA2           |   |   |   |   |   |   |   | OA2           |   |   |   |   |   |   |   | OA2           |   |   |   |   |   |   |   |
+
+G.709-Y.1331(16)\_F15-10
+
+Figure 15-10 – Frame alignment signal overhead structure
+
+#### 15.6.2.2 Multiframe alignment signal (MFAS)
+
+Some of the OTU and ODU overhead signals will span multiple OTU/ODU frames. Examples are the TTI and TCM-ACT overhead signals. These and other multiframe structured overhead signals require multiframe alignment processing to be performed, in addition to the OTU/ODU frame alignment.
+
+A single multiframe alignment signal (MFAS) byte is defined in row 1, column 7 of the OTU/ODU overhead for this purpose (see Figure 15-11). The value of the MFAS byte will be incremented each OTU/ODU frame and provides as such a 256-frame multiframe.
+
+The OTUk, OTU25 and OTU50 contain one instance of OTU multi-frame alignment overhead. The OTUCn contains n instances of OTU multi-frame alignment overhead, numbered 1 to n. All n MFAS bytes carry the same 256-frame sequence and in each frame all n MFAS bytes carry the same value.
+
+![](5a9cdc1fed33ae8fb871a8cd4d591729_img.jpg)
+
+|              |   |   |   |   |   |   |   |
+|--------------|---|---|---|---|---|---|---|
+| MFAS OH byte |   |   |   |   |   |   |   |
+| 1            | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
+| ⋮            |   |   |   |   |   |   |   |
+| 0            | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
+| 0            | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
+| 0            | 0 | 0 | 0 | 0 | 1 | 0 | 0 |
+| 0            | 0 | 0 | 0 | 0 | 1 | 1 | 1 |
+| 0            | 0 | 0 | 0 | 1 | 0 | 0 | 0 |
+| ⋮            |   |   |   |   |   |   |   |
+| 1            | 1 | 1 | 1 | 1 | 1 | 1 | 0 |
+| 1            | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
+| 0            | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
+| 0            | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
+
+MFAS sequence
+
+G.709-Y.1331(16)\_F15-11
+
+**Figure 15-11 – Multiframe alignment signal overhead**
+
+Individual OTU/ODU overhead signals may use this central multiframe to lock their 2-frame, 4-frame, 8-frame, 16-frame, 32-frame, etc., multiframes to the principal frame.
+
+NOTE 1 – The 80-frame OPU4 multiframe cannot be supported. A dedicated 80-frame OPU4 multiframe indicator (OMFI) is used instead.
+
+NOTE 2 – The 20-frame OPUCn and OPuk (k = 25) multiframe cannot be supported by MFAS. A dedicated 20-frame OPUCn and OPuk multiframe indicator (OMFI) is used instead.
+
+NOTE 3 – The 40-frame OPuk (k = 50) multiframe cannot be supported by MFAS. A dedicated 40-frame OPuk multiframe indicator (OMFI) is used instead.
+
+## 15.7 OTU OH description
+
+### 15.7.1 OTU overhead location
+
+The OTU overhead location is shown in Figures 15-12 and 15-13.
+
+The OTUk contains one instance of OTU overhead. The OTUCn contains n instances of OTU overhead, numbered 1 to n (OTU OH #1 to OTU OH #n).
+
+![](a4b868a176f7e0448ee72483727e9f6f_img.jpg)
+
+|       |              |                          |   |   |   |   |   |   |    |   |    |      |    |    |              |    |    |
+|-------|--------------|--------------------------|---|---|---|---|---|---|----|---|----|------|----|----|--------------|----|----|
+|       |              | Column #                 |   |   |   |   |   |   |    |   |    |      |    |    |              |    |    |
+|       |              | 1                        | 2 | 3 | 4 | 5 | 6 | 7 | 8  | 9 | 10 | 11   | 12 | 13 | 14           | 15 | 16 |
+| Row # | 1            | Frame alignment overhead |   |   |   |   |   |   | SM |   |    | GCC0 |    |    | OPU overhead |    |    |
+| 2     | ODU overhead |                          |   |   |   |   |   |   |    |   |    |      |    |    |              |    |    |
+| 3     |              |                          |   |   |   |   |   |   |    |   |    |      |    |    |              |    |    |
+| 4     |              |                          |   |   |   |   |   |   |    |   |    |      |    |    |              |    |    |
+
+|  |      |     |                                       |
+|--|------|-----|---------------------------------------|
+|  | 13   | 14  |                                       |
+|  | OSMC | RES | OTU frame structure #1 in OTUk        |
+|  | RES  |     | OTU frame structure #1 .. #n in OTUCn |
+
+G.709-Y.1331(16)-Amd.1(16)\_F15-12
+
+**Figure 15-12 – OTU overhead**
+
+![Figure 15-13 – OTU section monitoring overhead. The diagram shows the structure of OTU overhead for SM #1 and SM #2 to #n. SM #1 includes TTI, BIP-8, SAPI, DAPI, and Operator specific fields. SM #2 to #n includes RES, BIP-8, and OTUk/OTUCn fields. The OTUk and OTUCn fields are expanded to show their internal structure: BEI/BIAE, BDI, IAE, and RES for OTUk, and BEI/BIAE, BDI, and STAT for OTUCn.](87c64bd7d33fca8b9b29228c80ddf175_img.jpg)
+
+The diagram illustrates the OTU section monitoring overhead structure. It is divided into two main parts: SM, SM #1 and SM #2 to #n.
+
+**SM, SM #1:** This section contains the following fields:
+
+- Row 1:** TTI (Trail Trace Identifier), BIP-8 (Bit Interleaved Parity), and an empty cell.
+- Row 2:** SAPI (Section Alignment and Protection Information), which is further divided into subfields: BEI/BIAE (Backward Error Indication and Backward Incoming Alignment Error), BDI (Backward Defect Indication), IAE (Incoming Alignment Error), and RES (Reserved).
+- Row 3:** DAPI (Data Alignment and Protection Information), which is further divided into subfields: BEI/BIAE, BDI, and STAT (Status).
+- Row 4:** Operator specific.
+
+**SM #2 to #n:** This section contains the following fields:
+
+- Row 1:** RES (Reserved), BIP-8, and an empty cell.
+- Row 2:** OTUk or OTUCn, which is further divided into subfields: BEI/BIAE and RES.
+
+The diagram also includes a reference code: G.709-Y.1331(16)\_F15-13.
+
+Figure 15-13 – OTU section monitoring overhead. The diagram shows the structure of OTU overhead for SM #1 and SM #2 to #n. SM #1 includes TTI, BIP-8, SAPI, DAPI, and Operator specific fields. SM #2 to #n includes RES, BIP-8, and OTUk/OTUCn fields. The OTUk and OTUCn fields are expanded to show their internal structure: BEI/BIAE, BDI, IAE, and RES for OTUk, and BEI/BIAE, BDI, and STAT for OTUCn.
+
+**Figure 15-13 – OTU section monitoring overhead**
+
+### 15.7.2 OTU overhead definition
+
+#### 15.7.2.1 OTU section monitoring (SM) overhead
+
+One field of OTU section monitoring (SM) overhead is defined in row 1, columns 8 to 10 to support section monitoring.
+
+The OTUk, OTU25 and OTU50 contain one instance of OTU SM overhead. The OTUCn contains n instances of the OTU SM overhead, numbered 1 to n (SM #1 to SM #n).
+
+The SM and SM #1 field contains the following subfields (see Figure 15-13):
+
+- trail trace identifier (TTI);
+- bit interleaved parity (BIP-8);
+- backward defect indication (BDI);
+- backward error indication and backward incoming alignment error (BEI/BIAE);
+- incoming alignment error (IAE);
+- status bits indicating the presence of an incoming alignment error or a maintenance signal (STAT);
+- bits reserved for future international standardization (RES).
+
+The SM #2 to #n fields contain the following subfields (see Figure 15-13):
+
+- bit interleaved parity (BIP-8);
+- backward error indication and backward incoming alignment error (BEI/BIAE);
+- bits reserved for future international standardization (RES).
+
+##### 15.7.2.1.1 OTU SM trail trace identifier (TTI)
+
+For section monitoring, a one-byte trail trace identifier (TTI) overhead is defined to transport the 64-byte TTI signal specified in clause 15.2 or a discovery message as specified in [ITU-T G.7714.1].
+
+The OTUk, OTU25 and OTU50 and OTUCn contain one instance of OTU TTI overhead.
+
+The 64-byte TTI signal shall be aligned with the OTU multiframe (see clause 15.6.2.2) and transmitted four times per multiframe. Byte 0 of the 64-byte TTI signal shall be present at OTU multiframe positions 0000 0000 (0x00), 0100 0000 (0x40), 1000 0000 (0x80) and 1100 0000 (0xC0).
+
+##### 15.7.2.1.2 OTU SM error detection code (BIP-8)
+
+For section monitoring, a one-byte error detection code signal is defined in the OTU SM overhead. This byte provides a bit interleaved parity-8 (BIP-8) code.
+
+NOTE – The notation *BIP-8* refers only to the number of BIP bits and not to the EDC usage (i.e., what quantities are counted). For definition of BIP-8 refer to BIP-X definition in [ITU-T G.707].
+
+The OTU BIP-8 is computed over the bits in the OPU (columns 15 to 3824) area of OTU frame *i*, and inserted in the OTU BIP-8 overhead location in OTU frame *i*+2 (see Figure 15-14).
+
+The OTUk, OTU25 and OTU50 contain one instance of OTU BIP-8 overhead. The OTUCn contains *n* instances of the OTU BIP-8 overhead, numbered 1 to *n* (BIP-8 #1 to BIP-8 #*n*).
+
+![Diagram illustrating the OTU SM BIP-8 computation process across three frames (i, i+1, and i+2).](742a5484e7dd016256ab99921bbd635d_img.jpg)
+
+The diagram shows the structure of OTU frames and the flow of BIP-8 overhead. The horizontal axis represents columns, with markers at 1, 14, 15, and 3824. The vertical axis shows frames i, i+1, and i+2, each with four rows. In Frame i, columns 15 to 3824 are labeled 'OPU' and are highlighted in yellow. In Frame i, column 14 contains a 'BIP8' overhead block. In Frame i+1, column 14 also contains a 'BIP8' overhead block. In Frame i+2, column 14 contains a 'BIP8' overhead block. An arrow originates from the right side of the OPU block in Frame i, points to a yellow box labeled 'BIP8', and then points down to the 'BIP8' block in Frame i+2, column 14. The text 'G.709-Y.1331(16)\_F15-14' is in the bottom right corner.
+
+Diagram illustrating the OTU SM BIP-8 computation process across three frames (i, i+1, and i+2).
+
+Figure 15-14 – OTU SM BIP-8 computation
+
+##### 15.7.2.1.3 OTU SM backward defect indication (BDI)
+
+For section monitoring, a single-bit backward defect indication (BDI) signal is defined to convey the signal fail status detected in a section termination sink function in the upstream direction.
+
+BDI is set to "1" to indicate an OTU backward defect indication; otherwise, it is set to "0".
+
+The OTUk, OTU25 and OTU50 and OTUCn contain one instance of OTU BDI overhead.
+
+##### 15.7.2.1.4 OTU SM backward error indication and backward incoming alignment error (BEI/BIAE)
+
+For section monitoring, a four-bit backward error indication (BEI) and backward incoming alignment error (BIAE) signal is defined. This signal is used to convey in the upstream direction the count of interleaved-bit blocks that have been detected in error by the corresponding OTU section monitoring sink using the BIP-8 code. It is also used to convey in the upstream direction an incoming alignment error (IAE) condition that is detected in the corresponding OTU section monitoring sink in the IAE overhead.
+
+During an IAE condition the code "1011" is inserted into the BEI/BIAE field and the error count is ignored. Otherwise the error count (0-8) is inserted into the BEI/BIAE field. The remaining six possible values represented by these four bits can only result from some unrelated condition and shall be interpreted as zero errors (see Table 15-1) and BIAE not active.
+
+The OTUk, OTU25 and OTU50 contain one instance of OTU BEI/BIAE overhead. The OTUCn contains n instances of the OTU BEI/BIAE overhead, numbered 1 to n (BEI/BIAE #1 to BEI/BIAE #n).
+
+NOTE – The BIAE indication of an OTUCn is transported n times (ie. in OTUC SM # 1 to SM #n) and detected in OTUC SM #1 only.
+
+**Table 15-1 – OTU SM BEI/BIAE interpretation**
+
+| OTU SM BEI/BIAE<br>bits | 1 2 3 4                  | BIAE  | BIP violations |
+|-------------------------|--------------------------|-------|----------------|
+|                         | 0 0 0 0                  | false | 0              |
+|                         | 0 0 0 1                  | false | 1              |
+|                         | 0 0 1 0                  | false | 2              |
+|                         | 0 0 1 1                  | false | 3              |
+|                         | 0 1 0 0                  | false | 4              |
+|                         | 0 1 0 1                  | false | 5              |
+|                         | 0 1 1 0                  | false | 6              |
+|                         | 0 1 1 1                  | false | 7              |
+|                         | 1 0 0 0                  | false | 8              |
+|                         | 1 0 0 1, 1 0 1 0         | false | 0              |
+|                         | 1 0 1 1                  | true  | 0              |
+|                         | 1 1 0 0<br>to<br>1 1 1 1 | false | 0              |
+
+##### 15.7.2.1.5 OTUk, OTU25 and OTU50 SM incoming alignment error overhead (IAE)
+
+A single-bit incoming alignment error (IAE) signal is defined to allow the S-CMEP ingress point to inform its peer S-CMEP egress point that an alignment error in the incoming signal has been detected.
+
+IAE is set to "1" to indicate a frame alignment error, otherwise it is set to "0".
+
+The S-CMEP egress point may use this information to suppress the counting of bit errors, which may occur as a result of a frame phase change of the OTUk, OTU25, OTU50 at the ingress of the section.
+
+##### 15.7.2.1.6 OTU SM reserved overhead (RES)
+
+For section monitoring of the OTUk, OTU25 and OTU50, two bits in the SM overhead are reserved (RES) for future international standardization. They are set to "00".
+
+For section monitoring of the OTUCn, 12 bits in the SM overhead in the OTU frame structures #2 to #n are reserved for future international standardization. The value of these bits is set to "0".
+
+##### 15.7.2.1.7 OTUCn SM status (STAT)
+
+For section monitoring, three bits are defined as status bits (STAT). They indicate the presence of a maintenance signal or if there is an incoming alignment error at the source S-CMEP, (see Table 15-2).
+
+**Table 15-2 – OTUCn SM status interpretation**
+
+| bits | SM byte 3 |   |   | Status |                                                   |  |
+|------|-----------|---|---|--------|---------------------------------------------------|--|
+|      | 6         | 7 | 8 |        |                                                   |  |
+|      | 0 0 0     |   |   |        | Reserved for future international standardization |  |
+|      | 0 0 1     |   |   |        | In use without IAE                                |  |
+|      | 0 1 0     |   |   |        | In use with IAE                                   |  |
+|      | 0 1 1     |   |   |        | Reserved for future international standardization |  |
+|      | 1 0 0     |   |   |        | Reserved for future international standardization |  |
+|      | 1 0 1     |   |   |        | Reserved for future international standardization |  |
+|      | 1 1 0     |   |   |        | Reserved for future international standardization |  |
+|      | 1 1 1     |   |   |        | Maintenance signal: OTUCn-AIS                     |  |
+
+A S-CMEP ingress point sets these bits to either "001" to indicate to its peer S-CMEP egress point that there is no incoming alignment error (IAE), or to "010" to indicate that there is an incoming alignment error.
+
+The S-CMEP egress point may use this information to suppress the counting of bit errors, which may occur as a result of a frame phase change of the ODUCn at the ingress of the section.
+
+#### 15.7.2.2 OTU general communication channel 0 (GCC0)
+
+Two bytes are allocated in the OTU overhead to support a general communications channel or a discovery channel as specified in [ITU-T G.7714.1] between OTU termination points.
+
+This general communication channel is a clear channel and any format specification is outside of the scope of this Recommendation. These bytes are located in row 1, columns 11 and 12 of the OTU overhead.
+
+The OTUk, OTU25 and OTU50 contain one instance of OTU GCC0 overhead. The OTUCn contains n instances of the OTU GCC0 overhead, numbered 1 to n (GCC0 #1 to GCC0 #n).
+
+The GCC0 #1 to #n overhead are combined to provide one communication channel as illustrated in Figure 15-15 with an approximated bandwidth of  $n \times 13.768$  Mbit/s.
+
+NOTE – For vendor specific interfaces it is an option not to combine the GCC0 #1 to #n and instead use only the first GCC0 (GCC0 #1) as communication channel with an approximate bandwidth of 13.768 Mbit/s. GCC0 #2 to #n are not used.
+
+![Diagram showing the transmission order of OTUCn GCC0 channels. It shows a sequence of boxes labeled GCC0 #1, GCC0 #2, ..., GCC0 #n. Above each box are two sub-columns labeled 1 and 2. An arrow below the boxes points from left to right, labeled 'Transmission order'.](a04291a026e9ac4a7b644e556a0672b4_img.jpg)
+
+Diagram showing the transmission order of OTUCn GCC0 channels. It shows a sequence of boxes labeled GCC0 #1, GCC0 #2, ..., GCC0 #n. Above each box are two sub-columns labeled 1 and 2. An arrow below the boxes points from left to right, labeled 'Transmission order'.
+
+G.709-Y.1331(16)\_F15-15
+
+**Figure 15-15 – OTUCn GCC0 transmission order**
+
+#### 15.7.2.3 OTU reserved overhead (RES)
+
+One byte of the OTU overhead in OTU frame structure #1 is reserved for future international standardization. This byte is located in row 1, column 14. This byte is set to all-0s.
+
+Two bytes of the OTU overhead in OTU frame structures #2 to #n are reserved for future international standardization. These bytes are located in the OTU overhead in row 1, columns 13 and 14. These bytes are set to all-0s.
+
+#### 15.7.2.4 OTU OTN synchronisation message channel (OSMC)
+
+For synchronisation purposes, one byte is defined in the OTU overhead as an OTN synchronisation message channel to transport SSM, eSSM and PTP messages within SOTU and MOTU interfaces. The OSMC bandwidth is listed in Table 15-3.
+
+The OTUk, OTU25 and OTU50 contain one instance of OTU OSMC overhead.
+
+NOTE 1 – Support of OTU OSMC in an OTN interface is optional.
+
+NOTE 2 – Equipment designed prior to Edition 5.0 of this Recommendation may not be able to support OTU OSMC via their OTN point-to-point interfaces.
+
+NOTE 3 – OTN interfaces with vendor specific application identifiers may support an OSMC function. The encapsulation of the messages and overhead location are then vendor specific.
+
+NOTE 4 – Equipment designed prior to Edition 6.0 of this Recommendation may not be able to support OTU OSMC via their OTN optical networking interfaces.
+
+**Table 15-3 – OSMC bandwidth**
+
+| OTUk  | OSMC Bandwidth (kbit/s) |
+|-------|-------------------------|
+| OTU1  | 163.361                 |
+| OTU2  | 656.203                 |
+| OTU3  | 2,635.932               |
+| OTU4  | 6,851.101               |
+| OTU25 | 1,726.576               |
+| OTU50 | 3,453.153               |
+
+The SSM, eSSM and PTP messages are encapsulated into GFP-F frames as specified into [ITU-T G.704]. PTP event messages are timestamped and after encapsulation into GFP-F frames inserted into the OSMC as specified in clause 15.7.2.4.1. GFP-F encapsulated SSM and eSSM messages (and PTP non-event messages) are inserted into the OSMC at the earliest opportunity. GFP Idle frames may be inserted between successive GFP frames.
+
+The mapping of generic framing procedure (GFP) frames is performed by aligning the byte structure of every GFP frame with the byte of the OSMC overhead field. Since the GFP frames are of variable length and longer than one byte, a frame crosses the OTUk (k=1,2,3,4), OTU25 or OTU50 frame boundary.
+
+##### 15.7.2.4.1 Generation of event message timestamps
+
+###### 15.7.2.4.1.1 OTN interface event message timestamp point
+
+The OTN interface message timestamp point [ITU-T G.8260] for a PTP event message transported over the OSMC shall be the X-frame multiframe event preceding the beginning of the GFP frame in which the PTP event message is carried. See Figure 15-16. Since the GFP frames may be longer than X-4 bytes, a frame may cross the X-frame multiframe boundary. The X-frame multiframe contains frames numbered 0, 1, ..., X-1.
+
+###### 15.7.2.4.1.2 Event timestamp generation
+
+All PTP event messages are timestamped on egress and ingress OTN interfaces. The timestamp shall be the time at which the event message timestamp point passes the reference plane [ITU-T G.8260] marking the boundary between the PTP node (i.e., OTN node) and the network.
+
+###### **OTUk, OTU25 and OTU50**
+
+Event message timestamps are generated every X-frame multiframe period at the OTUk, OTU25 and OTU50 Access Point. X is 64 for k = 1 and 256 for k = 2,3,4 and OTU25 and OTU50.
+
+The first byte of a GFP(PTP event message) frame is inserted into the OTUk, OTU25 or OTU50 OSMC between 4 and X-1 frames after the X-frame multiframe boundary.
+
+NOTE 1 – The first byte of a GFP(PTP event message) frame is not inserted into the OTUk, OTU25 or OTU50 OSMC in frame 0...3 of the X-frame multiframe.
+
+![Timing diagram example for OTUk showing X-frame multiframe periods and PTP event message insertion points.](e2c120be98ede6deb60dd341f5a9803b_img.jpg)
+
+The diagram illustrates the timing of PTP event messages over a series of six 'X-frame multiframe period' intervals. A horizontal axis at the bottom is labeled 'Time'. Above the axis, six consecutive intervals are marked by vertical lines and labeled 'X-frame multiframe period'. Below each interval, a yellow box labeled 'PTP event message via OSMC' is shown. Red arrows point from the start of each interval to its corresponding box. The first arrow is labeled '≥ 4', indicating that the first PTP event message is generated at least 4 frames after the start of the first multiframe period. The third arrow points to the third box. The text 'G.709-Y.1331(16)\_F15-16' is located in the bottom right corner of the diagram area.
+
+Timing diagram example for OTUk showing X-frame multiframe periods and PTP event message insertion points.
+
+**Figure 15-16 – Timing diagram example for OTUk**
+
+NOTE 3 – This time synchronization over OTN interface implementation does not generate event message timestamps using a point other than the message timestamp point [ITU-T G.8260].
+
+In this time synchronization over OTN interface implementation, the timestamps are generated at a point removed from the reference plane. Furthermore, the time offset from the reference plane is likely to be different for inbound and outbound event messages. To meet the requirement of this subclause, the generated timestamps should be corrected for these offsets. Figure 19 in [b-IEEE 1588] illustrates these offsets. Based on this model, the appropriate corrections are as follows:
+
+$$\langle \text{egressTimestamp} \rangle = \langle \text{egressMeasuredTimestamp} \rangle + \text{egressLatency}$$
+
+$$\langle \text{ingressTimestamp} \rangle = \langle \text{ingressMeasuredTimestamp} \rangle - \text{ingressLatency}$$
+
+where the actual timestamps  $\langle \text{egressTimestamp} \rangle$  and  $\langle \text{ingressTimestamp} \rangle$  measured at the reference plane are computed from the detected, i.e., measured, timestamps by their respective latencies. Failure to make these corrections results in a time offset between the slave and master clocks.
+
+### 15.7.3 OTUkV overhead
+
+The functionally standardized OTUkV frame should support, as a minimum capability, section monitoring functionality comparable to the OTUk section monitoring (see clause 15.7.2.1) with a trail trace identifier as specified in clause 15.2. Further specification of this overhead is outside the scope of this Recommendation.
+
+## 15.8 ODU OH description
+
+### 15.8.1 ODU OH location
+
+The ODU overhead location is shown in Figures 15-17, 15-18 and 15-19.
+
+The ODUk contains one instance of ODU overhead. The ODUCn contains n instances of ODU overhead, numbered 1 to n (ODU OH #1 to ODU OH #n).
+
+![](6a7ea9d5162b0a0cfbd8d77c6cac90d1_img.jpg)
+
+**Column #**
+
+|   |                          |      |      |      |   |      |      |              |     |      |    |     |     |    |              |    |
+|---|--------------------------|------|------|------|---|------|------|--------------|-----|------|----|-----|-----|----|--------------|----|
+|   | 1                        | 2    | 3    | 4    | 5 | 6    | 7    | 8            | 9   | 10   | 11 | 12  | 13  | 14 | 15           | 16 |
+| 1 | Frame alignment overhead |      |      |      |   |      |      | OTU overhead |     |      |    |     |     |    | OPU overhead |    |
+| 2 | RES                      |      | EXP  | TCM6 |   |      | TCM5 |              |     | TCM4 |    |     | EXP |    |              |    |
+| 3 | TCM3                     |      | TCM2 |      |   | TCM1 |      |              | PM  |      |    | EXP |     |    |              |    |
+| 4 | GCC1                     | GCC2 |      |      |   |      |      |              | RES |      |    |     |     |    |              |    |
+
+Row # 1 2 3 4
+
+G.709-Y.1331(16)\_F15-17
+
+PM and TCM  
+ RES
+
+APS/PCC  
+ RES
+
+ODU frame structure #1 in ODUn and ODUCn  
+ ODU frame structure #2....#n in ODUCn
+
+**Figure 15-17 – ODU overhead**
+
+![](b35ea3e304aad7d350a9902270413930_img.jpg)
+
+**PM, PM #1**
+
+|     |       |   |
+|-----|-------|---|
+| 1   | 2     | 3 |
+| TTI | BIP-8 |   |
+
+**PM #2 to #n**
+
+|     |       |   |
+|-----|-------|---|
+| 1   | 2     | 3 |
+| RES | BIP-8 |   |
+
+0  
+ :  
+ SAPI  
+ :  
+ 15  
+ 16  
+ :  
+ DAPI  
+ :  
+ 31  
+ 32  
+ :  
+ Operator specific  
+ :  
+ 63
+
+1 2 3 4 5 6 7 8  
+ BEI BDI STAT
+
+1 2 3 4 5 6 7 8  
+ BEI RES
+
+**PM and TCM**
+
+1 2 3 4 5 6 7 8  
+ DMp
+
+G.709-Y.1331(16)\_F15-18
+
+**Figure 15-18 – ODU path monitoring overhead**
+
+![](a9159a006d67a834a7b1a771c18191cc_img.jpg)
+
+**TCMi, TCMi #1**
+
+|     |       |   |
+|-----|-------|---|
+| 1   | 2     | 3 |
+| TTI | BIP-8 |   |
+
+**TCMi #2 to #n**
+
+|     |       |   |
+|-----|-------|---|
+| 1   | 2     | 3 |
+| RES | BIP-8 |   |
+
+0  
+ :  
+ SAPI  
+ :  
+ 15  
+ 16  
+ :  
+ DAPI  
+ :  
+ 31  
+ 32  
+ :  
+ Operator specific  
+ :  
+ 63
+
+1 2 3 4 5 6 7 8  
+ BEI/BIAE BDI STAT
+
+1 2 3 4 5 6 7 8  
+ BEI/BIAE RES
+
+**PM and TCM**
+
+1 2 3 4 5 6 7 8  
+ DMt1 DMt2 DMt3 DMt4 DMt5 DMt6
+
+G.709-Y.1331(16)\_F15-19
+
+**Figure 15-19 – ODU tandem connection monitoring #i overhead**
+
+### 15.8.2 ODU OH definition
+
+#### 15.8.2.1 ODU path monitoring (PM) overhead
+
+One field of an ODU path monitoring overhead (PM) is defined in row 3, columns 10 to 12 to support path monitoring and one additional bit of path monitoring is defined in row 2, column 3, bit 7.
+
+The ODUk contains one instance of ODU PM overhead. The ODUCn contains n instances of the ODU PM overhead, numbered 1 to n (PM #1 to PM #n).
+
+The PM and PM #1 field contains the following subfields (see Figure 15-18):
+
+- trail trace identifier (TTI);
+- bit interleaved parity (BIP-8);
+- backward defect indication (BDI);
+- backward error indication (BEI);
+- status bits indicating the presence of a maintenance signal (STAT).
+
+The PM #2 to #n fields contain the following subfields (see Figure 15-18):
+
+- bit interleaved parity (BIP-8)
+- backward error indication (BEI)
+- reserved (RES).
+
+The PM&TCM field contains the following PM subfield (see Figure 15-18):
+
+- path delay measurement (DMp).
+
+For the case of ODUk, the content of the PM field, except the STAT subfield, will be undefined (pattern will be all-1s, 0110 0110 or 0101 0101 repeating) during the presence of a maintenance signal (e.g., ODU-AIS, ODU-OCI, ODU-LCK). The content of the PM&TCM field will be undefined (pattern will be all-1s, 0110 0110 or 0101 0101 repeating) during the presence of a maintenance signal. Refer to clause 16.5.
+
+For the case of ODUCn, the content of the PM field, except the STAT subfield, will be undefined (pattern will be all-1s or 0101 0101 repeating) during the presence of a maintenance signal (e.g., ODUCn-AIS, ODUCn-LCK). Refer to clause 16.5.
+
+##### 15.8.2.1.1 ODU PM trail trace identifier (TTI)
+
+For path monitoring, a one-byte trail trace identifier (TTI) overhead is defined to transport the 64-byte TTI signal specified in clause 15.2 or a discovery message as specified in [ITU-T G.7714.1].
+
+The ODUk and ODUCn contain one instance of ODU PM TTI overhead.
+
+The 64-byte TTI signal shall be aligned with the ODU multiframe (see clause 15.6.2.2) and transmitted four times per multiframe. Byte 0 of the 64-byte TTI signal shall be present at ODU multiframe positions 0000 0000 (0x00), 0100 0000 (0x40), 1000 0000 (0x80) and 1100 0000 (0xC0).
+
+##### 15.8.2.1.2 ODU PM error detection code (BIP-8)
+
+For path monitoring, a one-byte error detection code signal is defined in the ODU PM overhead. This byte provides a bit interleaved parity-8 (BIP-8) code.
+
+NOTE – The notation BIP-8 refers only to the number of BIP bits and not to the EDC usage (i.e., what quantities are counted). For definition of BIP-8, refer to the BIP-X definition in [ITU-T G.707].
+
+Each ODU BIP-8 is computed over the bits in the OPU (columns 15 to 3824) area of ODU frame i, and inserted in the ODU PM BIP-8 overhead location in the ODU frame i+2 (see Figure 15-20).
+
+The ODUk contains one instance of ODU PM BIP-8 overhead. The ODUCn contains n instances of the ODU PM BIP-8 overhead, numbered 1 to n (BIP-8 #1 to BIP-8 #n).
+
+![Diagram illustrating ODU PM BIP-8 computation across multiple frames (Frame i, Frame i+1, Frame i+2). The diagram shows the OPU (Optical Payload Unit) and the BIP-8 (Bit Interleaved Parity) overhead. The BIP-8 is computed over the OPU and is carried in the BIP-8 field of the ODU overhead. The diagram shows the BIP-8 field being updated in Frame i+2 based on the OPU data in Frame i.](a4de02b04a1a8f6cb8121ac2e11bf95a_img.jpg)
+
+The diagram shows a sequence of frames: Frame i, Frame i+1, and Frame i+2. Each frame has a header with byte positions 1, 14, 15, and 3824. Frame i contains an OPU (Optical Payload Unit) and a BIP-8 field. Frame i+1 contains a BIP-8 field. Frame i+2 contains a BIP-8 field. An arrow points from the BIP-8 field in Frame i to the BIP-8 field in Frame i+2, indicating the computation of the BIP-8 value.
+
+Diagram illustrating ODU PM BIP-8 computation across multiple frames (Frame i, Frame i+1, Frame i+2). The diagram shows the OPU (Optical Payload Unit) and the BIP-8 (Bit Interleaved Parity) overhead. The BIP-8 is computed over the OPU and is carried in the BIP-8 field of the ODU overhead. The diagram shows the BIP-8 field being updated in Frame i+2 based on the OPU data in Frame i.
+
+Figure 15-20 – ODU PM BIP-8 computation
+
+##### 15.8.2.1.3 ODU PM backward defect indication (BDI)
+
+For path monitoring, a single-bit backward defect indication (BDI) signal is defined to convey the signal fail status detected in a path termination sink function in the upstream direction.
+
+BDI is set to "1" to indicate an ODU backward defect indication, otherwise it is set to "0".
+
+The ODUk and ODUCn contain one instance of ODU PM BDI overhead.
+
+##### 15.8.2.1.4 ODU PM backward error indication (BEI)
+
+For path monitoring, a four-bit backward error indication (BEI) signal is defined to convey in the upstream direction the count of interleaved-bit blocks that have been detected in error by the corresponding ODU path monitoring sink using the BIP-8 code. This count has nine legal values, namely 0-8 errors. The remaining seven possible values represented by these four bits can only result from some unrelated condition and shall be interpreted as zero errors (see Table 15-2).
+
+The ODUk contains one instance of ODU PM BEI overhead. The ODUCn contains n instances of the ODU PM BEI overhead, numbered 1 to n (BEI #1 to BEI #n).
+
+Table 15-4 – ODU PM BEI interpretation
+
+| bits | ODU PM BEI |   |   |   | BIP violations |
+|------|------------|---|---|---|----------------|
+|      | 1          | 2 | 3 | 4 |                |
+|      | 0 0 0 0    |   |   |   | 0              |
+|      | 0 0 0 1    |   |   |   | 1              |
+|      | 0 0 1 0    |   |   |   | 2              |
+|      | 0 0 1 1    |   |   |   | 3              |
+|      | 0 1 0 0    |   |   |   | 4              |
+|      | 0 1 0 1    |   |   |   | 5              |
+|      | 0 1 1 0    |   |   |   | 6              |
+
+**Table 15-4 – ODU PM BEI interpretation**
+
+| bits | ODU PM BEI               | BIP violations |
+|------|--------------------------|----------------|
+|      | 1 2 3 4                  |                |
+|      | 0 1 1 1                  | 7              |
+|      | 1 0 0 0                  | 8              |
+|      | 1 0 0 1<br>to<br>1 1 1 1 | 0              |
+
+##### **15.8.2.1.5 ODU PM status (STAT)**
+
+For path monitoring, three bits are defined as status bits (STAT). They indicate the presence of a maintenance signal (see Table 15-3).
+
+A P-CMEP sets these bits to "001".
+
+The ODUk and ODUCn contain one instance of ODU PM STAT overhead.
+
+**Table 15-5 – ODU PM status interpretation**
+
+| bits | PM byte 3 | Status                                                                                        |
+|------|-----------|-----------------------------------------------------------------------------------------------|
+|      | 6 7 8     |                                                                                               |
+|      | 0 0 0     | Reserved for future international standardization                                             |
+|      | 0 0 1     | Normal path signal                                                                            |
+|      | 0 1 0     | Reserved for future international standardization                                             |
+|      | 0 1 1     | Reserved for future international standardization                                             |
+|      | 1 0 0     | Reserved for future international standardization                                             |
+|      | 1 0 1     | Maintenance signal: ODU-LCK                                                                   |
+|      | 1 1 0     | ODUk: Maintenance signal: ODU-OCI<br>ODUCn: Reserved for future international standardization |
+|      | 1 1 1     | Maintenance signal: ODU-AIS                                                                   |
+
+##### **15.8.2.1.6 ODU PM delay measurement (DMp)**
+
+For ODU path monitoring, a one-bit path delay measurement (DMp) signal is defined to convey the start of the delay measurement test.
+
+The ODUk and ODUCn contain one instance of ODU PM DMp overhead.
+
+The DMp signal consists of a constant value (0 or 1) that is inverted at the beginning of a two-way delay measurement test. The transition from 0→1 in the sequence ...0000011111..., or the transition from 1→0 in the sequence ...1111100000... represents the path delay measurement start point. The new value of the DMp signal is maintained until the start of the next delay measurement test.
+
+This DMp signal is inserted by the DMp originating P-CMEP and sent to the far-end P-CMEP. This far-end P-CMEP loops back the DMp signal towards the originating P-CMEP. The originating P-CMEP measures the number of frame periods between the moment the DMp signal value is inverted and the moment this inverted DMp signal value is received back from the far-end P-CMEP. The receiver should apply a persistency check on the received DMp signal to be tolerant for bit errors emulating the start of delay measurement indication. The additional frames that are used for such
+
+persistence checking should not be added to the delay frame count. The looping P-CMEP should loop back each received DMp bit within approximately 100  $\mu$ s.
+
+Refer to [ITU-T G.798] for the specific path delay measurement process specifications.
+
+NOTE 1 – Path delay measurements can be performed on-demand, to provide the momentary two-way transfer delay status, and pro-active, to provide 15-minute and 24-hour two-way transfer delay performance management snapshots.
+
+NOTE 2 – Equipment designed according to the 2008 or earlier versions of this Recommendation may not be capable of supporting this path delay monitoring. For such equipment, the DMp bit is a bit reserved for future international standardization and set to zero.
+
+NOTE 3 – This process measures a round trip delay. The one way delay may not be half of the round trip delay in the case where the transmit and receive directions of the ODU network connection are of unequal lengths (e.g., in networks deploying unidirectional protection switching).
+
+##### **15.8.2.1.7 ODU PM reserved overhead (RES)**
+
+For path monitoring of the OTUCn, 12 bits in the PM overhead in the ODU OH #2 to #n are reserved for future international standardization. The value of these bits is set to "0".
+
+The ODUk contains no ODU PM RES overhead. The ODUCn contains n-1 instances of the ODU PM RES overhead.
+
+#### **15.8.2.2 ODU tandem connection monitoring (TCM) overhead**
+
+Six fields of an ODU tandem connection monitoring (TCM) overhead are defined in row 2, columns 5 to 13 and row 3, columns 1 to 9 of the ODU overhead; and six additional bits of tandem connection monitoring are defined in row 2, column 3, bits 1 to 6.
+
+TCM supports monitoring of ODUk connections for one or more of the following network applications (refer to [ITU-T G.805], [ITU-T G.872], [ITU-T G.873.2] and [ITU-T G.7714.1]):
+
+- optical UNI-to-UNI tandem connection monitoring; monitoring the ODU connection through the public transport network (from public network ingress network termination to egress network termination);
+- optical NNI-to-NNI tandem connection monitoring; monitoring the ODU connection through the network of a network operator (from operator network ingress network termination to egress network termination);
+- sublayer monitoring for linear 1+1, 1:1 and 1:n ODUk subnetwork connection protection switching, to determine the signal fail and signal degrade conditions;
+- sublayer monitoring for ODUk shared ring protection (SRP-1) protection switching as specified in [ITU-T G.873.2], to determine the signal fail and signal degrade conditions;
+- sublayer monitoring for ODUk connection passing through two or more concatenated ODUk link connections (supported by back-to-back OTU trails), to provide a discovery message channel as specified in [ITU-T G.7714.1];
+- monitoring an ODUk tandem connection for the purpose of detecting a signal fail or signal degrade condition in a switched ODUk connection, to initiate automatic restoration of the connection during fault and error conditions in the network;
+- monitoring an ODUk tandem connection for, e.g., fault localization or verification of delivered quality of service.
+
+TCM supports monitoring of segments of ODUCn connections which span multiple OTSiA subnetworks. The ODUCn TC-CMEP are located on OTUCn interface ports at the edge of OTSiA subnetworks and/or on OTUCn interface ports in ODUCn terminating nodes (e.g., in ODUk cross connects).
+
+The six TCM fields are numbered TCM1, TCM2, ..., TCM6.
+
+The ODUk contains one instance of ODU TCM1 to TCM6 overhead. The ODUCn contains n instances of the ODU TCM1 to TCM6 overhead, numbered 1 to n (TCMi #1 to TCMi #n).
+
+Each TCMi and TCMi #1 field contains the following subfields (see Figure 15-19):
+
+- trail trace identifier (TTI);
+- bit interleaved parity 8 (BIP-8);
+- backward defect indication (BDI);
+- backward error indication and backward incoming alignment error (BEI/BIAE);
+- status bits indicating the presence of a TCM overhead, incoming alignment error, or a maintenance signal (STAT).
+
+Each TCMi #2 to #n field contains the following subfields (see Figure 15-19):
+
+- bit interleaved parity 8 (BIP-8);
+- backward error indication and backward incoming alignment error (BEI/BIAE);
+- reserved (RES).
+
+The PMandTCM field contains the following TCM subfields (see Figure 15-19):
+
+- tandem connection delay measurement (DMti, i=1 to 6).
+
+For the case of ODUk, the content of the TCM fields, except the STAT subfield, will be undefined (pattern will be all-1s, 0110 0110 or 0101 0101 repeating) during the presence of a maintenance signal (e.g., ODUk-AIS, ODUk-OCI, ODUk-LCK). The content of the PM&TCM field will be undefined (pattern will be all-1s, 0110 0110 or 0101 0101 repeating) during the presence of a maintenance signal. Refer to clause 16.5.
+
+For the case of ODUCn, the content of the TCM field groups, except the STAT subfield, will be undefined (pattern will be all-1s or 0101 0101 repeating) during the presence of a maintenance signal (e.g., ODUCn-AIS, ODUCn-LCK). The content of the PMand TCM field will be undefined (pattern will be all-1s or 0101 0101 repeating) during the presence of a maintenance signal. Refer to clause 6.5.
+
+A TCM field and PM&TCM bit is assigned to a monitored connection as described in clause 15.8.2.2.6. The number of monitored connections along an ODU trail may vary between 0 and 6. These monitored connections may be nested, cascaded or both. Nesting and cascading are the default operational configurations. Overlapping is an additional configuration for testing purposes only. Overlapped monitored connections must be operated in a non-intrusive mode in which the maintenance signals ODU-AIS and ODU-LCK are not generated. For the case where one of the endpoints in an overlapping monitored connection is located inside an SNC protected domain while the other endpoint is located outside the protected domain, the SNC protection should be forced to working when the endpoint of the overlapping monitored connection is located on the working connection, and forced to protection when the endpoint is located on the protection connection.
+
+Nesting and cascading configurations are shown in Figure 15-21. Monitored connections A1-A2/B1-B2/C1-C2 and A1-A2/B3-B4 are nested, while B1-B2/B3-B4 are cascaded. Overlapping is shown in Figure 15-22 (B1-B2 and C1-C2).
+
+![Figure 15-21: Example of nested and cascaded ODU monitored connections. The diagram shows a sequence of nodes (A1, B1, C1, C2, B2, B3, B4, A2) connected by arrows. Above each node is a stack of TCM fields (TCM1 to TCM6). TCM1 is yellow, TCM2 is blue, TCM3 is green, and TCM4, TCM5, and TCM6 are white. TCM1 is always present. TCM2 is present at B1, C1, C2, B2, and B3. TCM3 is present at C1 and C2. TCM4, TCM5, and TCM6 are present at all nodes. Below the nodes, horizontal double-headed arrows indicate connection segments: A1-A2 (full length), B1-B2 (between B1 and B2), C1-C2 (between C1 and C2), and B3-B4 (between B3 and B4). A legend at the bottom left shows a white box for 'TCMi TCM OH field not in use' and a yellow box for 'TCMi TCM OH field in use'. The text 'G.709-Y.1331(16)_F15-21' is in the bottom right.](e2dad48ec062e71202459a9ab82261e4_img.jpg)
+
+Figure 15-21: Example of nested and cascaded ODU monitored connections. The diagram shows a sequence of nodes (A1, B1, C1, C2, B2, B3, B4, A2) connected by arrows. Above each node is a stack of TCM fields (TCM1 to TCM6). TCM1 is yellow, TCM2 is blue, TCM3 is green, and TCM4, TCM5, and TCM6 are white. TCM1 is always present. TCM2 is present at B1, C1, C2, B2, and B3. TCM3 is present at C1 and C2. TCM4, TCM5, and TCM6 are present at all nodes. Below the nodes, horizontal double-headed arrows indicate connection segments: A1-A2 (full length), B1-B2 (between B1 and B2), C1-C2 (between C1 and C2), and B3-B4 (between B3 and B4). A legend at the bottom left shows a white box for 'TCMi TCM OH field not in use' and a yellow box for 'TCMi TCM OH field in use'. The text 'G.709-Y.1331(16)\_F15-21' is in the bottom right.
+
+**Figure 15-21 – Example of nested and cascaded ODU monitored connections**
+
+![Figure 15-22: Example of overlapping ODU monitored connections. The diagram shows a sequence of nodes (A1, B1, C1, B2, C2, A2) connected by arrows. Above each node is a stack of TCM fields (TCM1 to TCM6). TCM1 is yellow, TCM2 is blue, TCM3 is green, and TCM4, TCM5, and TCM6 are white. TCM1 is always present. TCM2 is present at B1, C1, B2, and C2. TCM3 is present at C1 and C2. TCM4, TCM5, and TCM6 are present at all nodes. Below the nodes, horizontal double-headed arrows indicate connection segments: A1-A2 (full length), B1-B2 (between B1 and B2), and C1-C2 (between C1 and C2). A legend at the bottom left shows a white box for 'TCMi TCM OH field not in use' and a yellow box for 'TCMi TCM OH field in use'. The text 'G.709-Y.1331(16)_F15-22' is in the bottom right.](8ab30dbff406204a68c59ae7c1b77413_img.jpg)
+
+Figure 15-22: Example of overlapping ODU monitored connections. The diagram shows a sequence of nodes (A1, B1, C1, B2, C2, A2) connected by arrows. Above each node is a stack of TCM fields (TCM1 to TCM6). TCM1 is yellow, TCM2 is blue, TCM3 is green, and TCM4, TCM5, and TCM6 are white. TCM1 is always present. TCM2 is present at B1, C1, B2, and C2. TCM3 is present at C1 and C2. TCM4, TCM5, and TCM6 are present at all nodes. Below the nodes, horizontal double-headed arrows indicate connection segments: A1-A2 (full length), B1-B2 (between B1 and B2), and C1-C2 (between C1 and C2). A legend at the bottom left shows a white box for 'TCMi TCM OH field not in use' and a yellow box for 'TCMi TCM OH field in use'. The text 'G.709-Y.1331(16)\_F15-22' is in the bottom right.
+
+**Figure 15-22 – Example of overlapping ODU monitored connections**
+
+##### 15.8.2.2.1 ODU TCM trail trace identifier (TTI)
+
+For each tandem connection monitoring field, one byte of overhead is allocated for the transport of the 64-byte trail trace identifier (TTI) specified in clause 15.2 or a discovery message as specified in [ITU-T G.7714.1] for TCM6.
+
+The ODUk and ODUCn contain one instance of ODU TTI overhead.
+
+The 64-byte TTI signal shall be aligned with the ODU multiframe (see clause 15.6.2.2) and transmitted four times per multiframe. Byte 0 of the 64-byte TTI signal shall be present at ODU multiframe positions 0000 0000 (0x00), 0100 0000 (0x40), 1000 0000 (0x80) and 1100 0000 (0xC0).
+
+##### 15.8.2.2.2 ODU TCM error detection code (BIP-8)
+
+For each tandem connection monitoring field, a one-byte error detection code signal is defined in the ODU TCMi overhead. This byte provides a bit interleaved parity-8 (BIP-8) code.
+
+NOTE – The notation *BIP-8* refers only to the number of BIP bits, and not to the EDC usage (i.e., what quantities are counted). For definition of BIP-8 refer to the BIP-X definition in [ITU-T G.707].
+
+Each ODU TCM BIP-8 is computed over the bits in the OPU (columns 15 to 3824) area of ODU frame *i*, and inserted in the ODU TCM BIP-8 overhead location (associated with the tandem connection monitoring level) in ODU frame *i+2* (see Figure 15-23).
+
+The ODUs contains one instance of ODU TCM<sub>i</sub> BIP-8 overhead. The ODUC<sub>n</sub> contains *n* instances of the ODU TCM<sub>i</sub> BIP-8 overhead, numbered 1 to *n* (BIP-8 #1 to BIP-8 #*n*).
+
+![Diagram illustrating ODU TCM BIP-8 computation across three frames (i, i+1, i+2).](ffb6acd27b8e3a54392840948a75869f_img.jpg)
+
+The diagram shows the relationship between ODU frames and the computation of BIP-8 overhead. The horizontal axis represents bits in the ODU frame, with columns 1 to 14 as overhead and 15 to 3824 as the OPU (Optical Payload Unit). The vertical axis shows three frames: Frame *i*, Frame *i+1*, and Frame *i+2*. In Frame *i*, the OPU (columns 15-3824) is highlighted in yellow. In Frame *i+1*, a BIP-8 overhead block is shown in columns 15-17. In Frame *i+2*, another BIP-8 overhead block is shown in columns 15-17. Arrows indicate that the BIP-8 value for Frame *i* is computed from the OPU of Frame *i* and is inserted into the BIP-8 overhead location of Frame *i+2*. The label 'G.709-Y.1331(16)\_F15-23' is in the bottom right corner.
+
+Diagram illustrating ODU TCM BIP-8 computation across three frames (i, i+1, i+2).
+
+Figure 15-23 – ODU TCM BIP-8 computation
+
+##### 15.8.2.2.3 ODU TCM backward defect indication (BDI)
+
+For each tandem connection monitoring field, a single-bit backward defect indication (BDI) signal is defined to convey the signal fail status detected in a tandem connection termination sink function in the upstream direction.
+
+BDI is set to "1" to indicate an ODUs backward defect indication; otherwise, it is set to "0".
+
+The ODUs and ODUC<sub>n</sub> contain one instance of ODU TCM<sub>i</sub> BDI overhead.
+
+##### 15.8.2.2.4 ODU TCM backward error indication (BEI) and backward incoming alignment error (BIAE)
+
+For each tandem connection monitoring field, a 4-bit backward error indication (BEI) and backward incoming alignment error (BIAE) signal is defined. This signal is used to convey in the upstream direction the count of interleaved-bit blocks that have been detected as being in error by the corresponding ODU tandem connection monitoring sink using the BIP-8 code. It is also used to convey in the upstream direction an incoming alignment error (IAE) condition that is detected in the corresponding ODU tandem connection monitoring sink in the IAE overhead.
+
+During an IAE condition the code "1011" is inserted into the BEI/BIAE field and the error count is ignored. Otherwise the error count (0-8) is inserted into the BEI/BIAE field. The remaining six possible values represented by these four bits can only result from some unrelated condition and shall be interpreted as zero errors (see Table 15-4) and BIAE not active.
+
+The ODuk contains one instance of ODU TCM BEI/BIAE overhead. The ODUCn contains n instances of the ODU TCMi BEI/BIAE overhead, numbered 1 to n (BEI/BIAE #1 to BEI/BIAE #n).
+
+**Table 15-6 – ODU TCM BEI/BIAE interpretation**
+
+| <b>ODUk TCM BEI/BIAE<br/>bits<br/>1 2 3 4</b> | <b>BIAE</b> | <b>BIP violations</b> |
+|-----------------------------------------------|-------------|-----------------------|
+| 0 0 0 0                                       | false       | 0                     |
+| 0 0 0 1                                       | false       | 1                     |
+| 0 0 1 0                                       | false       | 2                     |
+| 0 0 1 1                                       | false       | 3                     |
+| 0 1 0 0                                       | false       | 4                     |
+| 0 1 0 1                                       | false       | 5                     |
+| 0 1 1 0                                       | false       | 6                     |
+| 0 1 1 1                                       | false       | 7                     |
+| 1 0 0 0                                       | false       | 8                     |
+| 1 0 0 1, 1 0 1 0                              | false       | 0                     |
+| 1 0 1 1                                       | true        | 0                     |
+| 1 1 0 0 to 1 1 1 1                            | false       | 0                     |
+
+##### 15.8.2.2.5 ODU TCM status (STAT)
+
+For each tandem connection monitoring field, three bits are defined as status bits (STAT). They indicate the presence of a maintenance signal, if there is an incoming alignment error at the source TC-CMEP, or if there is no source TC-CMEP active (see Table 15-7).
+
+The ODuk and ODUCn contain one instance of ODU TCM STAT overhead.
+
+**Table 15-7 – ODU TCM status interpretation**
+
+| <b>TCM byte 3<br/>bits<br/>6 7 8</b> | <b>Status</b>                                                                                  |
+|--------------------------------------|------------------------------------------------------------------------------------------------|
+| 0 0 0                                | No source TC                                                                                   |
+| 0 0 1                                | In use without IAE                                                                             |
+| 0 1 0                                | In use with IAE                                                                                |
+| 0 1 1                                | Reserved for future international standardization                                              |
+| 1 0 0                                | Reserved for future international standardization                                              |
+| 1 0 1                                | Maintenance signal: ODU-LCK                                                                    |
+| 1 1 0                                | ODUk: Maintenance signal: ODUk-OCI<br>ODUCn: Reserved for future international standardization |
+| 1 1 1                                | Maintenance signal: ODU-AIS                                                                    |
+
+A P-CMEP sets these bits to "000".
+
+A TC-CMEP ingress point sets these bits to either "001" to indicate to its peer TC-CMEP egress point that there is no incoming alignment error (IAE), or to "010" to indicate that there is an incoming alignment error.
+
+The TC-CMEP egress point may use this information to suppress the counting of bit errors, which may occur as a result of a frame phase change of the ODU at the ingress of the tandem connection.
+
+##### 15.8.2.2.6 TCM overhead field assignment
+
+Each TC-CMEP will be inserting/extracting its TCM overhead from one of the 6 TCM<sub>i</sub> overhead fields and one of the 6 DM<sub>i</sub> fields. The specific TCM<sub>i</sub>/DM<sub>i</sub> overhead field is provisioned by the network operator, network management system or switching control plane.
+
+At a domain interface, it is possible to provision the maximum number (0 to 6) of tandem connection levels which will be passed through the domain. The default is three. These tandem connections should use the lower TCM<sub>i</sub>/DM<sub>i</sub> overhead fields TCM<sub>1</sub>/DM<sub>1</sub>...TCM<sub>MAX</sub>/DM<sub>MAX</sub>. Overhead in TCM/DM<sub>t</sub> fields beyond the maximum (TCM<sub>max+1</sub>/DM<sub>tmax+1</sub> and above) may/will be overwritten in the domain.
+
+The TCM6 overhead field is assigned to monitor an ODUk connection which is supported by two or more concatenated ODUk link connections (supported by back-to-back OTUk trails). [ITU-T G.7714.1] specifies a discovery application which uses the TCM6 TTI SAPI field as discovery message channel. [ITU-T G.873.2] specifies an ODUk SRP-1 protection application which uses the TCM6 field to monitor the status/performance of the ODUk connection between two adjacent ODUk SRP-1 nodes.
+
+###### Example
+
+For the case of an ODUk leased circuit, the user may have been assigned one level of TCM, the service provider one level of TCM and each network operator (having a contract with the service provider) four levels of TCM. For the case where a network operator subcontracts part of its ODUk connection to another network operator, these four levels are to be split; e.g., two levels for the subcontracting operator.
+
+This would result in the following TCM OH allocation:
+
+- User: TCM1/DM<sub>t1</sub> overhead field between the two user subnetworks, and TCM1/DM<sub>t1</sub>..TCM6/DM<sub>t6</sub> within its own subnetwork;
+- Service provider (SP): TCM2/DM<sub>t2</sub> overhead field between two UNIs;
+- Network operators NO1, NO2, NO3 having contract with service provider: TCM3/DM<sub>t3</sub>, TCM4/DM<sub>t4</sub>, TCM5/DM<sub>t5</sub>, TCM6/DM<sub>t6</sub>. Note that NO2 (which is subcontracting) cannot use TCM5/DM<sub>t5</sub> and TCM6/DM<sub>t6</sub> in the connection through the domain of NO4;
+- NO4 (having subcontract with NO2): TCM5/DM<sub>t5</sub>, TCM6/DM<sub>t6</sub>.
+
+See Figure 15-24.
+
+![Figure 15-24: Example of TCM overhead field assignment. The diagram shows a network path from a User to another User through several network operators (NO1, NO2, NO3, NO4). The path is segmented into ODUk paths. Below the path, a stack of TCM overhead fields (TCM1 to TCM6) is shown for each segment. The segments are labeled with the responsible operator: User, Network Operator 1, Network Operator 2, Network Operator 4, Network Operator 2, Network Operator 3, and User. A Service Provider segment is also indicated. The diagram is labeled G.709-Y.1331(16)_F15-24.](f78d2e126f00fcc5d8d9797ca410cc09_img.jpg)
+
+Figure 15-24: Example of TCM overhead field assignment. The diagram shows a network path from a User to another User through several network operators (NO1, NO2, NO3, NO4). The path is segmented into ODUk paths. Below the path, a stack of TCM overhead fields (TCM1 to TCM6) is shown for each segment. The segments are labeled with the responsible operator: User, Network Operator 1, Network Operator 2, Network Operator 4, Network Operator 2, Network Operator 3, and User. A Service Provider segment is also indicated. The diagram is labeled G.709-Y.1331(16)\_F15-24.
+
+**Figure 15-24 – Example of TCM overhead field assignment**
+
+##### 15.8.2.2.7 Blank clause
+
+*This clause is intentionally left blank.*
+
+##### 15.8.2.2.8 ODU TCM delay measurement (DM<sub>ti</sub>, i=1 to 6)
+
+For ODU tandem connection monitoring, a one-bit tandem connection delay measurement (DM<sub>ti</sub>) signal is defined to convey the start of the delay measurement test.
+
+The ODUk and ODUCn contain one instance of ODU TCM DM<sub>ti</sub> overhead.
+
+The DM<sub>ti</sub> signal consists of a constant value (0 or 1) that is inverted at the beginning of a two-way delay measurement test. The transition from 0→1 in the sequence ...0000011111..., or the transition from 1→0 in the sequence ...1111100000... represents the path delay measurement start point. The new value of the DM<sub>ti</sub> signal is maintained until the start of the next delay measurement test.
+
+This DM<sub>ti</sub> signal is inserted by the DM<sub>ti</sub> originating TC-CMEP and sent to the far-end TC-CMEP. This far-end TC-CMEP loops back the DM<sub>ti</sub> signal towards the originating TC-CMEP. The originating TC-CMEP measures the number of frame periods between the moment the DM<sub>ti</sub> signal value is inverted and the moment this inverted DM<sub>ti</sub> signal value is received back from the far-end TC-CMEP. The receiver should apply a persistency check on the received DM<sub>ti</sub> signal to be tolerant for bit errors emulating the start of delay measurement indication. The additional frames that are used for such persistency checking should not be added to the delay frame count. The looping TC-CMEP should loop back each received DM<sub>ti</sub> bit within approximately 100 µs.
+
+Refer to [ITU-T G.798] for the specific tandem connection delay measurement process specifications.
+
+NOTE 1 – Tandem connection delay measurements can be performed on-demand, to provide the momentary two-way transfer delay status, and pro-active, to provide 15-minute and 24-hour two-way transfer delay performance management snapshots.
+
+NOTE 2 – Equipment designed according to the 2008 or earlier versions of this Recommendation may not be capable of supporting this tandem connection delay monitoring. For such equipment, the DM<sub>ti</sub> bit is a bit reserved for future international standardization.
+
+NOTE 3 – This process measures a round trip delay. The one way delay may not be half of the round trip delay in the case where the transmit and receive directions of the ODUk tandem connection are of unequal lengths (e.g., in networks deploying unidirectional protection switching).
+
+##### 15.8.2.2.9 ODU TCM reserved overhead (RES)
+
+For tandem connection monitoring, 12 bits in the TCM<sub>i</sub> overhead are reserved for future international standardization in TCM<sub>i</sub> OH #2 to #n. The value of these bits is set to "0".
+
+The ODUk contains no ODU TCM<sub>i</sub> RES overhead. The ODUCn contains n-1 instances of the ODU TCM<sub>i</sub> RES overhead.
+
+#### 15.8.2.3 ODU general communication channels (GCC1, GCC2)
+
+Two fields of two bytes are allocated in the ODU overhead to support two general communications channels or two discovery channels as specified in [ITU-T G.7714.1] between any two network elements with access to the ODU frame structure (i.e., at 3R regeneration points).
+
+These general communication channels are clear channels and any format specification is outside of the scope of this Recommendation. The bytes for GCC1 are located in row 4, columns 1 and 2, and the bytes for GCC2 are located in row 4, columns 3 and 4 of the ODU overhead.
+
+The ODUn contains one instance of ODU GCC1, GCC2 overhead. The ODUCn contains n instances of the ODU GCC1, GCC2 overhead, numbered 1 to n (GCC1 #1 to GCC1 #n, GCC2 #1 to GCC2 #n).
+
+The GCC1 #1 to #n overhead are combined to provide one communication channel as illustrated in Figure 15-25 with an approximated bandwidth of  $n \times 13.768$  Mbit/s.
+
+The GCC2 #1 to #n overhead are combined to provide another communication channel as illustrated in Figure 15-25 with an approximated bandwidth of  $n \times 13.768$  Mbit/s.
+
+The GCC1 #1 to #n plus GCC2 #1 to #n overhead may be combined to provide one communication channel as illustrated in Figure 15-25 with an approximated bandwidth of  $n \times 27.525$  Mbit/s.
+
+![Figure 15-25: OTUCn GCC1, GCC2 and GCC1+2 transmission order diagram. The diagram shows three rows of data blocks representing transmission order. The first row, labeled 'OTUCn GCC1', shows blocks for GCC1 #1, GCC1 #2, ..., GCC1 #n, each with two sub-bytes (1 and 2). The second row, labeled 'OTUCn GCC2', shows blocks for GCC2 #1, GCC2 #2, ..., GCC2 #n, each with two sub-bytes (3 and 4). The third row, labeled 'OTUCn GCC1 + GCC2', shows interleaved blocks: GCC1 #1 (1, 2), GCC2 #1 (3, 4), GCC1 #2 (1, 2), GCC2 #2 (3, 4), ..., GCC1 #n (1, 2), GCC2 #n (3, 4). A horizontal arrow at the bottom indicates the 'Transmission order' from left to right. A small text 'G.709-Y.1331(20)_F15-25' is in the bottom right corner.](53001b5ae3f65139f78db410bb41ae30_img.jpg)
+
+Figure 15-25: OTUCn GCC1, GCC2 and GCC1+2 transmission order diagram. The diagram shows three rows of data blocks representing transmission order. The first row, labeled 'OTUCn GCC1', shows blocks for GCC1 #1, GCC1 #2, ..., GCC1 #n, each with two sub-bytes (1 and 2). The second row, labeled 'OTUCn GCC2', shows blocks for GCC2 #1, GCC2 #2, ..., GCC2 #n, each with two sub-bytes (3 and 4). The third row, labeled 'OTUCn GCC1 + GCC2', shows interleaved blocks: GCC1 #1 (1, 2), GCC2 #1 (3, 4), GCC1 #2 (1, 2), GCC2 #2 (3, 4), ..., GCC1 #n (1, 2), GCC2 #n (3, 4). A horizontal arrow at the bottom indicates the 'Transmission order' from left to right. A small text 'G.709-Y.1331(20)\_F15-25' is in the bottom right corner.
+
+Figure 15-25 – OTUCn GCC1, GCC2 and GCC1+2 transmission order
+
+#### 15.8.2.4 ODU automatic protection switching and protection communication channel (APS/PCC)
+
+A four-byte ODU-APS/PCC signal is defined in row 4, columns 5 to 8 of the ODU overhead. Up to eight levels of nested APS/PCC signals may be present in this field.
+
+The ODUn and ODUCn contain one instance of ODU APS/PCC overhead.
+
+For ODUn, the APS/PCC bytes in a given frame are assigned to a dedicated connection monitoring level depending on the value of MFAS as follows:
+
+Table 15-8 – Multiframe to allow separate APS/PCC for each monitoring level
+
+| MFAS |   |     | APS/PCC channel applies to connection monitoring level | Protection scheme using the APS/PCC channel (Note 1) |
+|------|---|-----|--------------------------------------------------------|------------------------------------------------------|
+| bits | 6 | 7 8 |                                                        |                                                      |
+|      | 0 | 0 0 | ODUn Path                                              | ODUn SNC/Ne, ODUn CL-SNCG/I, Client SNC/I, ODU SRP-p |
+|      | 0 | 0 1 | ODUn TCM1                                              | ODUn SNC/S, ODUn SNC/Ns                              |
+|      | 0 | 1 0 | ODUn TCM2                                              | ODUn SNC/S, ODUn SNC/Ns                              |
+
+**Table 15-8 – Multiframe to allow separate APS/PCC for each monitoring level**
+
+| MFAS |   |     | APS/PCC channel applies to connection monitoring level | Protection scheme using the APS/PCC channel (Note 1) |
+|------|---|-----|--------------------------------------------------------|------------------------------------------------------|
+| bits | 6 | 7 8 |                                                        |                                                      |
+| 0    | 1 | 1   | ODUk TCM3                                              | ODUk SNC/S, ODUk SNC/Ns                              |
+| 1    | 0 | 0   | ODUk TCM4                                              | ODUk SNC/S, ODUk SNC/Ns                              |
+| 1    | 0 | 1   | ODUk TCM5                                              | ODUk SNC/S, ODUk SNC/Ns                              |
+| 1    | 1 | 0   | ODUk TCM6                                              | ODUk SNC/S, ODUk SNC/Ns, ODU SRP-1                   |
+| 1    | 1 | 1   | ODUk server layer trail (Note 2)                       | ODUk SNC/I                                           |
+
+NOTE 1 – An APS channel may be used by more than one protection scheme and/or protection scheme instance. In case of nested protection schemes, care should be taken when an ODUk protection is to be set up in order not to interfere with the APS channel usage of another ODUk protection on the same connection monitoring level, e.g., protection can only be activated if that APS channel of the level is not already being used.
+
+NOTE 2 – Examples of ODUk server layer trails are an OTUk or a server ODUk (e.g., an ODU3 transporting an ODU1).
+
+For ODUCn, the APS/PCC signal is used to support coordination of the end points in linear (ODUk CL-SNCG/I) and ring (ODUk SRP) protection applications.
+
+For linear protection schemes, the bit assignments for these bytes and the bit-oriented protocol are given in [ITU-T G.873.1]. Bit assignment and byte-oriented protocol for ring protection schemes are given in [ITU-T G.873.2].
+
+#### 15.8.2.5 Blank clause
+
+*This clause is intentionally left blank.*
+
+#### 15.8.2.6 ODU experimental overhead (EXP)
+
+Four bytes are allocated in the ODU overhead for experimental use. These bytes are located in row 2, columns 4 and 14 and row 3, columns 13 and 14 of the ODU overhead.
+
+The ODUk contains one instance of ODU EXP overhead. The ODUCn contains n instances of the ODU EXP overhead, numbered 1 to n (EXP #1 to EXP #n).
+
+The use of these bytes is not subject to standardization and outside the scope of this Recommendation.
+
+An experimental overhead is provided in the ODU OH to allow a vendor and/or a network operator within their own (sub)network to support an application, which requires an additional ODU overhead.
+
+There is no requirement to forward the EXP overhead beyond the (sub)network; i.e., the operational span of the EXP overhead is limited to the (sub)network with the vendor's equipment, or the network of the operator.
+
+#### 15.8.2.7 ODU reserved overhead (RES)
+
+For the case of an ODUk, eight bytes and one bit are reserved in the ODU overhead for future international standardization. These bytes are located in row 2, columns 1 to 2 and row 4, columns 9 to 14 of the ODU overhead. The bit is located in row 2, column 3, bit 8 of the ODU overhead. These bytes are set to all-0s.
+
+For the case of an ODUCn, eight bytes and one bit in the ODU OH #1 and thirteen bytes in the ODU OH #2 to #n are reserved for future international standardization. These bytes are located in row 2, columns 1 to 2 and row 4, columns 9 to 14 of the ODU OH #1 and in row 2, columns 1 to 3 and row 4, columns 5 to 14 of the ODU OH #2 to #n. The bit is located in row 2, column 3, bit 8 of the ODU OH #1. These bytes and bit are set to all-0s.
+
+## 15.9 OPU OH description
+
+### 15.9.1 OPU OH location
+
+The OPU overhead consists of: payload structure identifier (PSI) including the payload type (PT), the overhead associated with the mapping of client signals into the OPU payload and the overhead associated with the hitless adjustment of ODUflex client signals. The OPU PSI and PT overhead locations are shown in Figure 15-26.
+
+The OPUk contains one instance of OPU overhead. The OPUCn contains n instances of OPU overhead, numbered 1 to n (OPU OH #1 to #n).
+
+![Figure 15-26 – OPU overhead. The diagram shows the structure of the OPU overhead in a grid of 16 columns and 4 rows. Row 1 contains 'Frame alignment overhead' (columns 1-7) and 'OTU overhead' (columns 8-15). Row 2 contains 'ODU overhead' (columns 1-15) and 'Mapping and adjustment specific' (column 16). Row 3 contains 'ODU overhead' (columns 1-15) and 'Mapping and adjustment specific' (column 16). Row 4 contains 'ODU overhead' (columns 1-15) and 'PSI' (column 16). A callout box shows a detailed view of the PSI (Payload Structure Identifier) in row 4, column 16. The PSI is a 256-byte structure. PSI[0] is the Payload Type (PT). PSI[1] to PSI[255] are 'Mapping specific'. The callout also shows 'OPU OH #1' pointing to the PT byte and 'OPU OH #2 to #n' pointing to the RES (Reserved) bytes.](0a3ab80d35c138cc4038b5758f6ff34d_img.jpg)
+
+Figure 15-26 – OPU overhead. The diagram shows the structure of the OPU overhead in a grid of 16 columns and 4 rows. Row 1 contains 'Frame alignment overhead' (columns 1-7) and 'OTU overhead' (columns 8-15). Row 2 contains 'ODU overhead' (columns 1-15) and 'Mapping and adjustment specific' (column 16). Row 3 contains 'ODU overhead' (columns 1-15) and 'Mapping and adjustment specific' (column 16). Row 4 contains 'ODU overhead' (columns 1-15) and 'PSI' (column 16). A callout box shows a detailed view of the PSI (Payload Structure Identifier) in row 4, column 16. The PSI is a 256-byte structure. PSI[0] is the Payload Type (PT). PSI[1] to PSI[255] are 'Mapping specific'. The callout also shows 'OPU OH #1' pointing to the PT byte and 'OPU OH #2 to #n' pointing to the RES (Reserved) bytes.
+
+Figure 15-26 – OPU overhead
+
+### 15.9.2 OPU OH definition
+
+#### 15.9.2.1 OPU payload structure identifier (PSI)
+
+One byte is allocated in the OPU overhead to transport a 256-byte payload structure identifier (PSI) signal. The byte is located in row 4, column 15 of the OPU overhead.
+
+The OPUk contains one instance of OPU PSI overhead. The OPUCn contains n instances of the OPU PSI overhead, numbered 1 to n (PSI #1 to PSI #n).
+
+The 256-byte PSI signal is aligned with the ODU multiframe (i.e., PSI[0] is present at ODU multiframe position 0000 0000, PSI[1] at position 0000 0001, PSI[2] at position 0000 0010, etc.).
+
+PSI[0] contains a one-byte payload type or is reserved for future international standardization. PSI[1] to PSI[255] are mapping specific, except for PT 0x01 (experimental mapping) and PTs 80-0x8F (for proprietary use).
+
+##### 15.9.2.1.1 OPU payload type (PT)
+
+A one-byte payload type signal is defined in the PSI[0] byte of the payload structure identifier to indicate the composition of the OPU signal. The code points are defined in Table 15-9.
+
+The OPUk and OPUCn contain one instance of OPU PT overhead.
+
+**Table 15-9 – Payload type code points**
+
+| <b>MSB<br/>1 2 3 4</b> | <b>LSB<br/>5 6 7 8</b> | <b>Hex code<br/>(Note 1)</b> | <b>Interpretation</b>                                                                                                                                                                                                |
+|------------------------|------------------------|------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| 0 0 0 0                | 0 0 0 1                | 01                           | Experimental mapping (Note 3)                                                                                                                                                                                        |
+| 0 0 0 0                | 0 0 1 0                | 02                           | Asynchronous CBR mapping, see clause 17.2                                                                                                                                                                            |
+| 0 0 0 0                | 0 0 1 1                | 03                           | Bit-synchronous CBR mapping, see clause 17.2                                                                                                                                                                         |
+| 0 0 0 0                | 0 1 0 0                | 04                           | Not available (Note 2)                                                                                                                                                                                               |
+| 0 0 0 0                | 0 1 0 1                | 05                           | GFP mapping, see clause 17.4                                                                                                                                                                                         |
+| 0 0 0 0                | 0 1 1 0                | 06                           | Not available (Note 2)                                                                                                                                                                                               |
+| 0 0 0 0                | 0 1 1 1                | 07                           | PCS codeword transparent Ethernet mapping:<br>1000BASE-X into OPU0, see clauses 17.7.1 and 17.7.1.1<br>40GBASE-R into OPU3, see clauses 17.7.4 and 17.7.4.1<br>100GBASE-R into OPU4, see clauses 17.7.5 and 17.7.5.1 |
+| 0 0 0 0                | 1 0 0 0                | 08                           | FC-1200 into OPU2e mapping, see clause 17.8.2                                                                                                                                                                        |
+| 0 0 0 0                | 1 0 0 1                | 09                           | GFP mapping into extended OPU2 payload, see clause 17.4.1<br>(Note 5)                                                                                                                                                |
+| 0 0 0 0                | 1 0 1 0                | 0A                           | STM-1 mapping into OPU0, see clause 17.7.1                                                                                                                                                                           |
+| 0 0 0 0                | 1 0 1 1                | 0B                           | STM-4 mapping into OPU0, see clause 17.7.1                                                                                                                                                                           |
+| 0 0 0 0                | 1 1 0 0                | 0C                           | FC-100 mapping into OPU0, see clause 17.7.1                                                                                                                                                                          |
+| 0 0 0 0                | 1 1 0 1                | 0D                           | FC-200 mapping into OPU1, see clause 17.7.2                                                                                                                                                                          |
+| 0 0 0 0                | 1 1 1 0                | 0E                           | FC-400 mapping into OPUflex, see clause 17.9                                                                                                                                                                         |
+| 0 0 0 0                | 1 1 1 1                | 0F                           | FC-800 mapping into OPUflex, see clause 17.9                                                                                                                                                                         |
+| 0 0 0 1                | 0 0 0 0                | 10                           | Bit stream with octet timing mapping, see clause 17.6.1                                                                                                                                                              |
+| 0 0 0 1                | 0 0 0 1                | 11                           | Bit stream without octet timing mapping, see clause 17.6.2                                                                                                                                                           |
+| 0 0 0 1                | 0 0 1 0                | 12                           | IB SDR mapping into OPUflex, see clause 17.9                                                                                                                                                                         |
+| 0 0 0 1                | 0 0 1 1                | 13                           | IB DDR mapping into OPUflex, see clause 17.9                                                                                                                                                                         |
+| 0 0 0 1                | 0 1 0 0                | 14                           | IB QDR mapping into OPUflex, see clause 17.9                                                                                                                                                                         |
+| 0 0 0 1                | 0 1 0 1                | 15                           | SDI mapping into OPU0, see clause 17.7.1                                                                                                                                                                             |
+| 0 0 0 1                | 0 1 1 0                | 16                           | (1.485/1.001) Gbit/s SDI mapping into OPU1,<br>see clause 17.7.2                                                                                                                                                     |
+| 0 0 0 1                | 0 1 1 1                | 17                           | 1.485 Gbit/s SDI mapping into OPU1, see clause 17.7.2                                                                                                                                                                |
+| 0 0 0 1                | 1 0 0 0                | 18                           | (2.970/1.001) Gbit/s SDI mapping into OPUflex,<br>see clause 17.9                                                                                                                                                    |
+| 0 0 0 1                | 1 0 0 1                | 19                           | 2.970 Gbit/s SDI mapping into OPUflex, see clause 17.9                                                                                                                                                               |
+| 0 0 0 1                | 1 0 1 0                | 1A                           | SBCON/ESCON mapping into OPU0, see clause 17.7.1                                                                                                                                                                     |
+| 0 0 0 1                | 1 0 1 1                | 1B                           | DVB_ASI mapping into OPU0, see clause 17.7.1                                                                                                                                                                         |
+| 0 0 0 1                | 1 1 0 0                | 1C                           | FC-1600 mapping into OPUflex, see clause 17.9                                                                                                                                                                        |
+| 0 0 0 1                | 1 1 0 1                | 1D                           | FlexE Client mapping into OPUflex, see clause 17.11                                                                                                                                                                  |
+| 0 0 0 1                | 1 1 1 0                | 1E                           | FlexE aware (partial rate) mapping into OPUflex,<br>see clause 17.12                                                                                                                                                 |
+| 0 0 0 1                | 1 1 1 1                | 1F                           | FC-3200 mapping into OPUflex, see clause 17.9                                                                                                                                                                        |
+
+**Table 15-9 – Payload type code points**
+
+| MSB<br>1 2 3 4 | LSB<br>5 6 7 8 | Hex code<br>(Note 1) | Interpretation                                                                                           |
+|----------------|----------------|----------------------|----------------------------------------------------------------------------------------------------------|
+| 0 0 1 0        | 0 0 0 0        | 20                   | ODU multiplex structure supporting ODTUjk only, see clause 19 (AMP only)                                 |
+| 0 0 1 0        | 0 0 0 1        | 21                   | ODU multiplex structure supporting ODTUk.ts or ODTUk.ts and ODTUjk, see clause 19 (GMP capable) (Note 6) |
+| 0 0 1 0        | 0 0 1 0        | 22                   | ODU multiplex structure supporting ODTUCn.ts, see clause 20 (GMP capable)                                |
+| 0 0 1 1        | 0 0 0 0        | 30                   | 25GBASE-R mapping into OPUflex, see clause 17.13                                                         |
+| 0 0 1 1        | 0 0 0 1        | 31                   | 200GBASE-R mapping into OPUflex, see clause 17.13                                                        |
+| 0 0 1 1        | 0 0 1 0        | 32                   | 400GBASE-R mapping into OPUflex, see clause 17.13                                                        |
+| 0 0 1 1        | 0 0 1 1        | 33                   | 50GBASE-R mapping into OPUflex, see clause 17.13                                                         |
+| 0 1 0 1        | 0 1 0 1        | 55                   | Not available (Note 2)                                                                                   |
+| 0 1 1 0        | 0 1 1 0        | 66                   | Not available (Note 2)                                                                                   |
+| 1 0 0 0        | x x x x        | 80-8F                | Reserved codes for proprietary use (Note 4)                                                              |
+| 1 1 1 1        | 1 1 0 1        | FD                   | NULL test signal mapping, see clause 17.5.1                                                              |
+| 1 1 1 1        | 1 1 1 0        | FE                   | PRBS test signal mapping, see clause 17.5.2                                                              |
+| 1 1 1 1        | 1 1 1 1        | FF                   | Not available (Note 2)                                                                                   |
+
+NOTE 1 – There are 197 spare codes left for future international standardization. Refer to Annex A of [ITU-T G.806] for the procedure to obtain one of these codes for a new payload type.
+
+NOTE 2 – These values are excluded from the set of available code points. These bit patterns are present in ODUk maintenance signals or were used to represent client types that are no longer supported.
+
+NOTE 3 – Value "01" is only to be used for experimental activities in cases where a mapping code is not defined in this table. Refer to Annex A of [ITU-T G.806] for more information on the use of this code.
+
+NOTE 4 – These 16 code values will not be subject to further standardization. Refer to Annex A of [ITU-T G.806] for more information on the use of these codes.
+
+NOTE 5 – Supplement 43 (2008) to the ITU-T G-series of Recommendations indicated that this mapping recommended using payload type 87.
+
+NOTE 6 – Equipment supporting ODTUk.ts for OPU2 or OPU3 must be backward compatible with equipment which supports only the ODTUjk. ODTUk.ts capable equipment transmitting PT=21 which receives PT=20 from the far end shall revert to PT=20 and operate in ODTUjk only mode. Refer to [ITU-T G.798] for the specification.
+
+### 15.9.2.2 OPU mapping specific overhead
+
+Seven bytes are reserved in the OPUk overhead for the mapping and hitless adjustment specific overhead. These bytes are located in rows 1 to 3, columns 15 and 16 and column 16 row 4. In addition, 255 bytes in the PSI #1 and 256 byte in PSI #2 to #n are reserved for specific purposes.
+
+The use of these bytes depends on the specific client signal mapping (defined in clauses 17, 19 and 20) and use of hitless adjustment of ODUflex(GFP) (see [ITU-T G.7044]).
+
+## 16 Maintenance signals
+
+An alarm indication signal (AIS) is a signal sent downstream as an indication that an upstream defect has been detected. An AIS signal is generated in an adaptation sink function. An AIS signal is detected in a trail termination sink function to suppress defects or failures that would otherwise be detected as a consequence of the interruption of the transport of the original signal at an upstream point.
+
+A forward defect indication (FDI) is a signal sent downstream as an indication that an upstream defect has been detected. An FDI signal is generated in an adaptation sink function. An FDI signal is detected in a trail termination sink function to suppress defects or failures that would otherwise be detected as a consequence of the interruption of the transport of the original signal at an upstream point.
+
+NOTE – AIS and FDI are similar signals. AIS is used as the term when the signal is in the digital domain. FDI is used as the term when the signal is in the optical domain; FDI is transported as a non-associated overhead.
+
+An open connection indication (OCI) is a signal sent downstream as an indication that upstream the signal is not connected to a trail termination source. An OCI signal is generated in a connection function and output by this connection function on each of its output connection points, which are not connected to one of its input connection points. An OCI signal is detected in a trail termination sink function.
+
+A locked (LCK) is a signal sent downstream as an indication that upstream the connection is "locked", and no signal has passed through.
+
+A payload missing indication (PMI) is a signal sent downstream as an indication that upstream at the source point of the signal none of the frequency slots have an optical tributary signal. This indicates that the transport of the optical tributary signals is interrupted or no optical tributary signals are present.
+
+A PMI signal is generated in the trail termination source function and it is detected in the trail termination sink function which suppresses the LOS defect that arises under this condition.
+
+## **16.1 OTS maintenance signals**
+
+### **16.1.1 OTS payload missing indication (OTS-PMI)**
+
+OTS-PMI is generated as an indication that the OTS payload does not contain an optical signal.
+
+## **16.2 OMS maintenance signals**
+
+Three OMS maintenance signals are defined: OMS-FDI-P, OMS-FDI-O and OMS-PMI.
+
+### **16.2.1 OMS forward defect indication – Payload (OMS-FDI-P)**
+
+OMS-FDI-P is generated as an indication of an OMS server layer defect in the OTS network layer.
+
+### **16.2.2 OMS forward defect indication – Overhead (OMS-FDI-O)**
+
+OMS-FDI-O is generated as an indication when the transport of OMS OH via the OSC is interrupted due to a signal fail condition in the OSC.
+
+### **16.2.3 OMS payload missing indication (OMS-PMI)**
+
+OMS-PMI is generated as an indication when none of the frequency slots contain an optical tributary signal.
+
+## **16.3 OCh and OTSiA maintenance signals**
+
+Three OCh and OTSiA maintenance signals are defined: OCh-FDI-P, OCh-FDI-O, OCh-OCI and OTSiA-FDI-P, OTSiA-FDI-O, OTSiA-OCI.
+
+### **16.3.1 OCh and OTSiA forward defect indication – Payload (OCh-FDI-P, OTSiA-FDI-P)**
+
+OCh-FDI-P and OTSiA-FDI-P are generated as an indication for an OCh and OTSiA server layer defect in the OMS network layer.
+
+When the OTUk or OTUCn is terminated, the OCh-FDI-P and OTSiA\_FDI-P is continued as an ODUk-AIS signal.
+
+When the OTUCn is not terminated, the OCh-FDI-P and OTSiA\_FDI-P are continued as an OTUCn-AIS signal.
+
+OTSiA-FDI-O is generated as an indication when the transport of OTSiA OH via the OSC is interrupted due to a signal fail condition in the OSC.
+
+### 16.3.2 OCh and OTiSA forward defect indication – Overhead (OCh-FDI-O, OTSiA-FDI-O)
+
+OCh-FDI-O is generated as an indication when the transport of OCh OH via the OSC or OCC is interrupted due to a signal fail condition in the OSC or OCC.
+
+### 16.3.3 OCh and OTiSA open connection indication (OCh-OCI, OTSiA-OCI)
+
+The OCh-OCI/OTSiA-OCI signal indicates to downstream transport processing functions that the OCh/OTSiA connection is not bound to, or not connected (via a matrix connection) to a termination source function. The indication is used in order to distinguish downstream between a missing OCh/OTSiA signal due to a defect or due to the open connection (resulting from a management command).
+
+NOTE – OCI is detected at the next downstream OCh or OTSiA trail terminating equipment. If the connection was opened intentionally, the related alarm report from this trail termination should be disabled by using the alarm reporting control mode (refer to [ITU-T M.3100]).
+
+## 16.4 OTU maintenance signals
+
+### 16.4.1 OTUk (k=1,2,3) alarm indication signal (OTUk-AIS)
+
+The OTUk-AIS (k=1,2,3) (see Figure 16-1) is a generic-AIS signal (see clause 16.6.1). Since the OTUk capacity (130 560 bits) is not an integer multiple of the PN-11 sequence length (2047 bits), the PN-11 sequence may cross an OTUk frame boundary.
+
+NOTE – OTUk-AIS is defined to support a future server layer application. OTN equipment should be capable of detecting the presence of such a signal within OTUk (k=1,2,3) on OTN point-to-point interface signals; it is not required to generate such a signal.
+
+![Diagram of OTUk-AIS signal structure showing a repeating PN-11 sequence across columns and rows.](7fe4241eea8865aa6d2686d711c13ba6_img.jpg)
+
+The diagram illustrates the structure of an OTUk-AIS signal. It shows a grid of columns and rows. The columns are numbered from 1 to 4080, with specific markers at 1, 14, 15, 3824, 3825, and 4080. The rows are numbered 1, 2, 3, and 4. A large rectangular box spans across the columns, labeled 'Repeating PN-11 sequence'. Above the box, the text 'Column #' is centered, and below the box, the text 'Row #' is centered. The sequence is shown repeating across the columns, with a break indicated by '.....' between columns 14 and 15, and another break between columns 3825 and 4080.
+
+Diagram of OTUk-AIS signal structure showing a repeating PN-11 sequence across columns and rows.
+
+G.709-Y.1331(12)\_F16-1
+
+Figure 16-1 – OTUk-AIS
+
+### 16.4.2 OTUCn alarm indication signal (OTUCn-AIS)
+
+The OTUCn-AIS is specified as all "1"s in the entire OTUCn signal, excluding the frame alignment overhead (FA OH) (see Figure 16-2).
+
+The presence of the OTUCn-AIS is detected by monitoring the OTUCn SM STAT bits in the SM overhead fields.
+
+NOTE – OTUCn-AIS is defined to support a future 3R regenerator application in which the OTUCn is not terminated and an OTUCn subrating application. OTN equipment should be capable of detecting the presence of such a signal within OTUCn signals on OTN optical networking interfaces.
+
+![Figure 16-2 – OTUCn-AIS. Two diagrams showing the structure of OTUCn-AIS. The top diagram for OTU #1 shows a frame with columns 1 to 3824 and rows 1 to 4. Row 1 contains FA OH (columns 1-7), STAT (columns 8-14), and an All-1s pattern (columns 15-3824). Rows 2-4 are entirely All-1s pattern. The bottom diagram for OTU #2 to #n shows a similar frame, but the STAT field is omitted, so FA OH ends at column 14, and the All-1s pattern starts at column 15.](e8f5117fb031f413a836525061addd61_img.jpg)
+
+G.709-Y.1331(16)\_F16-2
+
+Figure 16-2 – OTUCn-AIS. Two diagrams showing the structure of OTUCn-AIS. The top diagram for OTU #1 shows a frame with columns 1 to 3824 and rows 1 to 4. Row 1 contains FA OH (columns 1-7), STAT (columns 8-14), and an All-1s pattern (columns 15-3824). Rows 2-4 are entirely All-1s pattern. The bottom diagram for OTU #2 to #n shows a similar frame, but the STAT field is omitted, so FA OH ends at column 14, and the All-1s pattern starts at column 15.
+
+**Figure 16-2 – OTUCn-AIS**
+
+## 16.5 ODU maintenance signals
+
+Three ODU maintenance signals are defined: ODU-AIS, ODU-OCI and ODU-LCK.
+
+### 16.5.1 ODU alarm indication signal (ODU-AIS)
+
+ODUk-AIS is specified as all "1"s in the entire ODU signal, excluding the frame alignment overhead (FA OH), OTU overhead (OTU OH) (see Figure 16-3).
+
+The ODUk contains one instance of ODU AIS. The ODUCn contains n instances of ODU AIS, numbered 1 to n (ODU AIS #1 to #n).
+
+![Figure 16-3 – ODU-AIS. A diagram showing the structure of ODU-AIS. The frame has columns 1 to 3824 and rows 1 to 4. Row 1 contains FA OH (columns 1-7), OTU OH (columns 8-16), and an All-1s pattern (columns 17-3824). Rows 2-4 are entirely All-1s pattern.](4bb669bb31262e53e4f3c8ec0fd7624a_img.jpg)
+
+G.709-Y.1331(16)\_F16-3
+
+Figure 16-3 – ODU-AIS. A diagram showing the structure of ODU-AIS. The frame has columns 1 to 3824 and rows 1 to 4. Row 1 contains FA OH (columns 1-7), OTU OH (columns 8-16), and an All-1s pattern (columns 17-3824). Rows 2-4 are entirely All-1s pattern.
+
+**Figure 16-3 – ODU-AIS**
+
+In addition, the ODU-AIS signal may be extended with one or more levels of ODU tandem connection, GCC1, GCC2, EXP and/or APS/PCC overhead before it is presented at the OTN interface. This is dependent on the functionality between the ODU-AIS insertion point and the OTN interface.
+
+The presence of the ODU-AIS is detected by monitoring the ODU STAT bits in the PM and TCMi overhead fields.
+
+### 16.5.2 ODUk open connection indication (ODUk-OCI)
+
+ODUk-OCI is specified as a repeating "0110 0110" pattern in the entire ODUk signal, excluding the frame alignment overhead (FA OH) and OTUk overhead (OTUk OH) (see Figure 16-4).
+
+NOTE – ODUCn OCI is not defined.
+
+![Diagram of ODUk-OCI signal structure showing columns 1 to 3824 and rows 1 to 4. Row 1 contains FA OH (columns 1-7) and OTUk OH (columns 8-14). Rows 2-4 contain the repeating '0110 0110' pattern.](750b1652a4f4791b84c02aa755a1dedd_img.jpg)
+
+The diagram illustrates the ODUk-OCI signal structure. It shows a grid of columns (1 to 3824) and rows (1 to 4). Row 1 is divided into three segments: FA OH (columns 1 to 7), OTUk OH (columns 8 to 14), and the repeating "0110 0110" pattern (columns 15 to 3824). Rows 2, 3, and 4 are entirely occupied by the repeating "0110 0110" pattern. The text "G.709-Y.1331(16)\_F16-4" is located at the bottom right.
+
+Diagram of ODUk-OCI signal structure showing columns 1 to 3824 and rows 1 to 4. Row 1 contains FA OH (columns 1-7) and OTUk OH (columns 8-14). Rows 2-4 contain the repeating '0110 0110' pattern.
+
+**Figure 16-4 – ODUk-OCI**
+
+NOTE – The repeating "0110 0110" pattern is the default pattern; other patterns are also allowed as long as the STAT bits in the PM and TCMi overhead fields are set to "110".
+
+In addition, the ODUk-OCI signal may be extended with one or more levels of ODUk tandem connection, GCC1, GCC2, EXP and/or APS/PCC overhead before it is presented at the OTM interface. This is dependent on the functionality between the ODUk-OCI insertion point and the OTM interface.
+
+The presence of ODUk-OCI is detected by monitoring the ODUk STAT bits in the PM and TCMi overhead fields.
+
+### 16.5.3 ODU locked (ODU-LCK)
+
+ODU-LCK is specified as a repeating "0101 0101" pattern in the entire ODU signal, excluding the frame alignment overhead (FA OH) and OTU overhead (OTU OH) (see Figure 16-5).
+
+![Diagram of ODU-LCK signal structure showing columns 1 to 3824 and rows 1 to 4. Row 1 contains FA OH (columns 1-7) and OTU OH (columns 8-14). Rows 2-4 contain the repeating '0101 0101' pattern.](fbdd4682fb49c08ff8415c854336a6ab_img.jpg)
+
+The diagram illustrates the ODU-LCK signal structure. It shows a grid of columns (1 to 3824) and rows (1 to 4). Row 1 is divided into three segments: FA OH (columns 1 to 7), OTU OH (columns 8 to 14), and the repeating "0101 0101" pattern (columns 15 to 3824). Rows 2, 3, and 4 are entirely occupied by the repeating "0101 0101" pattern. The text "G.709-Y.1331(16)\_F16-5" is located at the bottom right.
+
+Diagram of ODU-LCK signal structure showing columns 1 to 3824 and rows 1 to 4. Row 1 contains FA OH (columns 1-7) and OTU OH (columns 8-14). Rows 2-4 contain the repeating '0101 0101' pattern.
+
+**Figure 16-5 – ODU-LCK**
+
+NOTE – The repeating "0101 0101" pattern is the default pattern; other patterns are also allowed as long as the STAT bits in the PM and TCMi overhead fields are set to "101".
+
+In addition, the ODU-LCK signal may be extended with one or more additional levels of ODU tandem connection, GCC1, GCC2, EXP and/or the APS/PCC overhead before it is presented at the OTN interface. This is dependent on the functionality between the ODU-LCK insertion point and the OTN interface.
+
+The presence of ODU-LCK is detected by monitoring the ODU STAT bits in the PM and TCMi overhead fields.
+
+## 16.6 Client maintenance signal
+
+### 16.6.1 Generic AIS for constant bit rate signals
+
+The generic-AIS signal is a signal with a 2 047-bit polynomial number 11 (PN-11) repeating sequence.
+
+The PN-11 sequence is defined by the generating polynomial  $1 + x^9 + x^{11}$  as specified in clause 5.2 of [ITU-T O.150]. (See Figure 16-6.)
+
+![Figure 16-6 – Generic-AIS generating circuit. The diagram shows a chain of 10 D flip-flops (D Q) connected in series. A 'Clock' signal is connected to the clock input of each flip-flop. The output of the 10th flip-flop is labeled 'Generic-AIS'. A feedback path is shown from the output of the 10th flip-flop, through an XOR gate (indicated by a circle with a plus sign), back to the input of the first flip-flop. The text 'G.709-Y.1331(16)_F16-6' is located in the bottom right corner of the diagram.](145fb9b19dc6513e7bf84c9ba7f083f2_img.jpg)
+
+Figure 16-6 – Generic-AIS generating circuit. The diagram shows a chain of 10 D flip-flops (D Q) connected in series. A 'Clock' signal is connected to the clock input of each flip-flop. The output of the 10th flip-flop is labeled 'Generic-AIS'. A feedback path is shown from the output of the 10th flip-flop, through an XOR gate (indicated by a circle with a plus sign), back to the input of the first flip-flop. The text 'G.709-Y.1331(16)\_F16-6' is located in the bottom right corner of the diagram.
+
+Figure 16-6 – Generic-AIS generating circuit
+
+## 17 Mapping of client signals
+
+This clause specifies the mapping of:
+
+- STM-16, STM-64, STM-256 constant bit rate client signals into OPUk using client/server specific asynchronous or bit-synchronous mapping procedures (AMP, BMP);
+- 10GBASE-R constant bit rate client signal into OPU2e using client/server specific bit-synchronous mapping procedure (BMP);
+- FC-1200 constant bit rate client signal after timing transparent transcoding (TTT) providing a 50/51 rate compression into OPU2e using client/server specific byte-synchronous mapping procedure;
+- constant bit rate client signals with bit rates up to 1.238 Gbit/s into OPU0 and up to 2.488 Gbit/s into OPU1 using a client agnostic generic mapping procedure (GMP) possibly preceded by a timing transparent transcoding (TTT) of the client signal to reduce the bit rate of the signal to fit the OPUk payload bandwidth;
+- constant bit rate client signals into OPU1, OPU2, OPU3 or OPU4 respectively using a client agnostic generic mapping procedure (GMP) possibly preceded by a timing transparent transcoding (TTT) of the client signal to reduce the bit rate of the signal to fit the OPUk payload bandwidth;
+- other constant bit rate client signals into OPUflex using a client agnostic bit-synchronous mapping procedure (BMP);
+- packet streams (e.g., Ethernet, MPLS, IP) which are encapsulated with the generic framing procedure (GFP-F);
+- test signals;
+- continuous mode GPON constant bit rate client signal into OPU1 using asynchronous mapping procedure (AMP);
+- continuous mode XGPON constant bit rate client signal into OPU2 using asynchronous mapping procedure (AMP);
+- FlexE-aware client signal into OPUflex using bitsynchronous mapping procedure (BMP);
+- FlexE Client client signal into OPUflex using idle mapping procedure;
+- packet streams (e.g., Ethernet, MPLS, IP) which are encapsulated with the Idle mapping procedure (IMP) into OPU.
+
+**17.1 OPU client signal fail (CSF)**
+
+For support of local management systems, a single-bit OPU client signal fail (CSF) indicator is defined to convey the signal fail status of the CBR and Ethernet private line client signal mapped into an OPU at the ingress of the OTN to the egress of the OTN.
+
+OPU CSF is located in bit 1 of the PSI[2] byte of the payload structure identifier. Bits 2 to 8 of the PSI[2] byte are reserved for future international standardization. These bits are set to all-0s.
+
+OPU CSF is set to "1" to indicate a client signal fail indication, otherwise it is set to "0".
+
+NOTE – Equipment designed prior to Edition 3.0 of the Recommendation will generate a "0" in the OPUk CSF and will ignore any value in OPUk CSF.
+
+**17.2 Mapping of CBR2G5, CBR10G, CBR10G3 and CBR40G signals into OPUk**
+
+The mapping of a CBR2G5, CBR10G or CBR40G signal (with up to  $\pm 20$  ppm bit-rate tolerance) into an OPUk ( $k = 1, 2, 3$ ) may be performed according to the bit-synchronous mapping procedure based on one generic OPUk frame structure (see Figure 17-1). The mapping of a CBR2G5, CBR10G or CBR40G signal (with up to  $\pm 45$  ppm bit-rate tolerance) into an OPUk ( $k = 1, 2, 3$ ) may be performed according to the asynchronous mapping procedure. The mapping of a CBR10G3 signal (with up to  $\pm 100$  ppm bit-rate tolerance) into an OPUk ( $k = 2e$ ) is performed using the bit-synchronous mapping procedure.
+
+NOTE 1 – Examples of CBR2G5, CBR10G and CBR40G signals are STM-16 and CMGPON\_D/U2 (refer to [ITU-T G.984.6]), STM-64 and CMXGPON\_D/U2 [ITU-T G.987.4] and STM-256. An example of a CBR10G3 signal is 10GBASE-R.
+
+NOTE 2 – The maximum bit-rate tolerance between an OPUk and the client signal clock, which can be accommodated by the asynchronous mapping scheme, is  $\pm 65$  ppm. With a bit-rate tolerance of  $\pm 20$  ppm for the OPUk clock, the client signal's bit-rate tolerance can be  $\pm 45$  ppm.
+
+NOTE 3 – For OPUk ( $k=1,2,3$ ) the clock tolerance is  $\pm 20$  ppm. For OPU2e the clock tolerance is  $\pm 100$  ppm and asynchronous mapping cannot be supported with this justification overhead.
+
+![Figure 17-1: OPUk frame structure for the mapping of a CBR2G5, CBR10G or CBR40G signal. The diagram shows a grid of rows and columns. Rows 1-3 contain RES and JC bytes. Row 4 contains PSI, NJO, PJO, and a large OPUk payload (4 x 3808 bytes). A callout shows the PSI byte structure: PT (Payload Type), CSF (Client Signal Fail), and RES (Reserved). Another callout shows the JC byte structure with bits 0-1 and 7-8 as JC and 2-6 as Reserved.](f43d225d8fed2845b8d7e5afecbfe636_img.jpg)
+
+| Column | 15  | 16  | 17  | 18                            |  | 3824 |
+|--------|-----|-----|-----|-------------------------------|--|------|
+| 1      | RES | JC  |     |                               |  |      |
+| 2      | RES | JC  |     |                               |  |      |
+| 3      | RES | JC  |     |                               |  |      |
+| 4      | PSI | NJO | PJO | OPUk payload (4 × 3808 bytes) |  |      |
+
+|     |                                                                                                  |
+|-----|--------------------------------------------------------------------------------------------------|
+| 0   | <strong>PT</strong>                                                                              |
+| 1   | <span style="writing-mode: vertical-rl; transform: rotate(180deg);"><strong></strong> CSF</span> |
+| 2   |                                                                                                  |
+| PSI | <strong></strong> RES                                                                            |
+| ⋮   |                                                                                                  |
+| 255 |                                                                                                  |
+
+|    |    |   |                            |   |   |   |   |    |   |
+|----|----|---|----------------------------|---|---|---|---|----|---|
+|    | 0  | 1 | 2                          | 3 | 4 | 5 | 6 | 7  | 8 |
+| JC | JC |   | <strong></strong> Reserved |   |   |   |   | JC |   |
+
+Figure 17-1: OPUk frame structure for the mapping of a CBR2G5, CBR10G or CBR40G signal. The diagram shows a grid of rows and columns. Rows 1-3 contain RES and JC bytes. Row 4 contains PSI, NJO, PJO, and a large OPUk payload (4 x 3808 bytes). A callout shows the PSI byte structure: PT (Payload Type), CSF (Client Signal Fail), and RES (Reserved). Another callout shows the JC byte structure with bits 0-1 and 7-8 as JC and 2-6 as Reserved.
+
+**Figure 17-1 – OPUk frame structure for the mapping of a CBR2G5, CBR10G or CBR40G signal**
+
+The OPUk overhead for these mappings consists of a payload structure identifier (PSI) including the payload type (PT), a client signal fail (CSF) indicator and 254 bytes plus 7 bits reserved for future international standardization (RES), three justification control (JC) bytes, one negative justification opportunity (NJO) byte, and three bytes reserved for future international standardization (RES).
+
+The JC bytes consist of two bits for justification control and six bits reserved for future international standardization.
+
+The OPUk payload for these mappings consists of  $4 \times 3808$  bytes, including one positive justification opportunity (PJO) byte.
+
+The justification control (JC) signal, which is located in rows 1, 2 and 3 of column 16, bits 7 and 8, is used to control the two justification opportunity bytes NJO and PJO that follow in row 4.
+
+The asynchronous and bit-synchronous mapping processes generate the JC, NJO and PJO according to Tables 17-1 and 17-2, respectively. The de-mapping process interprets JC, NJO and PJO according to Table 17-3. Majority vote (two out of three) shall be used to make the justification decision in the de-mapping process to protect against an error in one of the three JC signals.
+
+**Table 17-1 – JC, NJO and PJO generation by an asynchronous mapping process**
+
+| JC   |     | NJO                | PJO                |
+|------|-----|--------------------|--------------------|
+| bits | 7 8 |                    |                    |
+| 0 0  |     | justification byte | data byte          |
+| 0 1  |     | data byte          | data byte          |
+| 1 0  |     | not generated      |                    |
+| 1 1  |     | justification byte | justification byte |
+
+**Table 17-2 – JC, NJO and PJO generation by a bit-synchronous mapping process**
+
+| JC   |     | NJO                | PJO       |
+|------|-----|--------------------|-----------|
+| bits | 7 8 |                    |           |
+| 0 0  |     | justification byte | data byte |
+| 0 1  |     | not generated      |           |
+| 1 0  |     |                    |           |
+| 1 1  |     |                    |           |
+
+**Table 17-3 – JC, NJO and PJO interpretation**
+
+| JC            |     | NJO                | PJO                |
+|---------------|-----|--------------------|--------------------|
+| bits          | 7 8 |                    |                    |
+| 0 0           |     | justification byte | data byte          |
+| 0 1           |     | data byte          | data byte          |
+| 1 0<br>(Note) |     | justification byte | data byte          |
+| 1 1           |     | justification byte | justification byte |
+
+NOTE – A mapper circuit does not generate this code. Due to bit errors a de-mapper circuit might receive this code.
+
+The value contained in NJO and PJO when they are used as justification bytes is all-0s. The receiver is required to ignore the value contained in these bytes whenever they are used as justification bytes.
+
+During a signal fail condition of the incoming CBR2G5, CBR10G or CBR40G client signal (e.g., in the case of a loss of input signal), this failed incoming signal is replaced by the generic-AIS signal as specified in clause 16.6.1, and is then mapped into the OPUs.
+
+During a signal fail condition of the incoming 10GBASE-R type CBR10G3 client signal (e.g., in the case of a loss of input signal), this failed incoming 10GBASE-R signal is replaced by a stream of 66B blocks, with each block carrying two local fault sequence ordered sets (as specified in [IEEE 802.3]). This 66B block stream replacement signal is scrambled before mapping into the OPU2e. A self-synchronizing scrambler with generator polynomial  $1+x^{39}+x^{58}$  shall be used, which is identical to the scrambler specified in clause 49.2.6 of [IEEE 802.3].
+
+During the signal fail condition of the incoming ODUk/OPUk signal (e.g., in the case of an ODUk-AIS, ODUk-LCK, ODUk-OCI condition) the generic-AIS pattern as specified in clause 16.6.1 is generated as a replacement signal for the lost CBR2G5, CBR10G or CBR40G signal.
+
+During the signal fail condition of the incoming ODU2e/OPU2e signal (e.g., in the case of an ODU2e-AIS, ODU2e-LCK, ODU2e-OCI condition) a stream of 66B blocks, with each block carrying two local fault sequence ordered sets (as specified in [IEEE 802.3]) is generated as a replacement signal for the lost 10GBASE-R signal. This 66B block stream replacement signal is scrambled using a self-synchronizing scrambler with generator polynomial  $1+x^{39}+x^{58}$ , which is identical to the scrambler specified in clause 49.2.6 of [IEEE 802.3].
+
+NOTE 4 – Local fault sequence ordered set is /K28.4/D0.0/D0.0/D1.0/. The 66B block contains the following value SH=10 0x55 00 00 01 00 00 00 01.
+
+NOTE 5 – Equipment developed prior to Edition 2.5 of this Recommendation may generate a different 10GBASE-R replacement signal (e.g., Generic-AIS) than the local fault sequence ordered set.
+
+### Asynchronous mapping
+
+The OPUk signal for the asynchronous mapping is created from a locally generated clock (within the limits specified in Table 7-3), which is independent of the CBR2G5, CBR10G or CBR40G (i.e.,  $4^{(k-1)} \times 2\,488\,320$  kbit/s ( $k = 1,2,3$ )) client signal.
+
+The CBR2G5, CBR10G, CBR40G (i.e.,  $4^{(k-1)} \times 2\,488\,320$  kbit/s ( $k = 1,2,3$ )) signal is mapped into the OPUk using a positive/negative/zero (pnz) justification scheme.
+
+### Bit-synchronous mapping
+
+The OPUk clock for bit-synchronous mapping is derived from the CBR2G5, CBR10G, CBR40G or CBR10G3 client signal. During signal fail conditions of the incoming CBR2G5, CBR10G, CBR40G or CBR10G3 signal (e.g., in the case of a loss of input signal), the OPUk payload signal bit rate shall be within the limits specified in Table 7-3 and the limits defined for the ODCb clock in [ITU-T G.8251] and no OPUk frame phase discontinuity shall be introduced in this case and when resynchronizing on the incoming CBR2G5, CBR10G, CBR40G or CBR10G3 signal.
+
+The CBR2G5, CBR10G, CBR40G or CBR10G3 signal is mapped into the OPUk without using the justification capability within the OPUk frame: NJO contains a justification byte, PJO contains a data byte, and the JC signal is fixed to 00.
+
+#### 17.2.1 Mapping a CBR2G5 signal (e.g., STM-16, CMGPON\_D/CMGPON\_U2) into OPU1
+
+Groups of eight successive bits (not necessarily being a byte) of the CBR2G5 signal are mapped into a data (D) byte of the OPU1 (see Figure 17-2). Once per OPU1 frame, it is possible to perform either a positive or a negative justification action.
+
+| Row # | Column # |     |     |    |       | 3824 |
+|-------|----------|-----|-----|----|-------|------|
+|       | 15       | 16  | 17  | 18 | ..... |      |
+| 1     | RES      | JC  | D   | D  | 3805D | D    |
+| 2     | RES      | JC  | D   | D  | 3805D | D    |
+| 3     | RES      | JC  | D   | D  | 3805D | D    |
+| 4     | PSI      | NJO | PJO | D  | 3805D | D    |
+
+G.709-Y.1331(12)\_F17-2
+
+Figure 17-2 – Mapping of a CBR2G5 signal into OPU1
+
+### 17.2.2 Mapping a CBR10G signal (e.g., STM-64, CMXGPON\_D/CMXGPON\_U2) into OPU2
+
+Groups of eight successive bits (not necessarily being a byte) of the CBR10G signal are mapped into a data (D) byte of the OPU2 (see Figure 17-3). 64 fixed stuff (FS) bytes are added in columns 1905 to 1920. Once per OPU2 frame, it is possible to perform either a positive or a negative justification action.
+
+| Row # | Column # |     |     |                 |                           |            |
+|-------|----------|-----|-----|-----------------|---------------------------|------------|
+|       | 15       | 16  | 17  | .....           | 1904 1905 ..... 1920 1921 | ..... 3824 |
+| 1     | RES      | JC  |     | 118 × 16D       | 16FS                      | 119 × 16D  |
+| 2     | RES      | JC  |     | 118 × 16D       | 16FS                      | 119 × 16D  |
+| 3     | RES      | JC  |     | 118 × 16D       | 16FS                      | 119 × 16D  |
+| 4     | PSI      | NJO | PJO | 15D + 117 × 16D | 16FS                      | 119 × 16D  |
+
+G.709-Y.1331(12)\_F17-3
+
+Figure 17-3 – Mapping of a CBR10G signal into OPU2
+
+### 17.2.3 Mapping a CBR40G signal (e.g., STM-256) into OPU3
+
+Groups of eight successive bits (not necessarily being a byte) of the CBR40G signal are mapped into a data (D) byte of the OPU3 (see Figure 17-4). 128 fixed stuff (FS) bytes are added in columns 1265 to 1280 and 2545 to 2560. Once per OPU3 frame, it is possible to perform either a positive or a negative justification action.
+
+| Row # | Column # |     |     |                |                         |          |                         |          |
+|-------|----------|-----|-----|----------------|-------------------------|----------|-------------------------|----------|
+|       | 15       | 16  | 17  | .....          | 1264 1265 ... 1280 1281 | .....    | 2544 2545 ... 2560 2561 | ... 3824 |
+| 1     | RES      | JC  |     | 78 × 16D       | 16FS                    | 79 × 16D | 16FS                    | 79 × 16D |
+| 2     | RES      | JC  |     | 78 × 16D       | 16FS                    | 79 × 16D | 16FS                    | 79 × 16D |
+| 3     | RES      | JC  |     | 78 × 16D       | 16FS                    | 79 × 16D | 16FS                    | 79 × 16D |
+| 4     | PSI      | NJO | PJO | 15D + 77 × 16D | 16FS                    | 79 × 16D | 16FS                    | 79 × 16D |
+
+G.709-Y.1331(12)\_F17-4
+
+Figure 17-4 – Mapping of a CBR40G signal into OPU3
+
+### 17.2.4 Mapping a CBR10G3 signal (e.g., 10GBASE-R) into OPU2e
+
+Groups of eight successive bits (not necessarily being a byte) of the CBR10G3 signal are bit-synchronously mapped into a data (D) byte of the OPU2e (see Figure 17-5). 64 fixed stuff (FS) bytes are added in columns 1905 to 1920.
+
+NOTE – The NJO byte will always carry a stuff byte, the PJO byte will always carry a data (D) byte and the JC bytes will always carry the all-0s pattern.
+
+| Row # | Column # |     |           |                 |      |      |       |      |      |            |
+|-------|----------|-----|-----------|-----------------|------|------|-------|------|------|------------|
+|       | 15       | 16  | 17        | .....           | 1904 | 1905 | ..... | 1920 | 1921 | ..... 3824 |
+| 1     | RES      | JC  | 118 × 16D |                 |      |      |       |      | 16FS | 119 × 16D  |
+| 2     | RES      | JC  | 118 × 16D |                 |      |      |       |      | 16FS | 119 × 16D  |
+| 3     | RES      | JC  | 118 × 16D |                 |      |      |       |      | 16FS | 119 × 16D  |
+| 4     | PSI      | NJO | PJO       | 15D + 117 × 16D |      |      |       |      | 16FS | 119 × 16D  |
+
+G.709-Y.1331(12)\_F17-5
+
+Figure 17-5 – Mapping of a CBR10G3 signal into OPU2e
+
+### 17.3 Blank clause
+
+*This clause is intentionally left blank.*
+
+### 17.4 Mapping of GFP frames into OPUk (k=0,1,2,3,4,flex)
+
+The mapping of generic framing procedure (GFP) frames is performed by aligning the byte structure of every GFP frame with the byte structure of the OPUk payload (see Figure 17-6). Since the GFP frames are of variable length (the mapping does not impose any restrictions on the maximum frame length), a frame may cross the OPUk (k=0,1,2,3,4,flex) frame boundary.
+
+![Figure 17-6: OPUk frame structure and mapping of GFP frames into OPUk. The diagram shows the OPUk frame structure with 4 rows and columns 15 to 3824. Row 1: RES, RES, ..., RES, RES, ..., RES, RES. Row 2: RES, RES, ..., RES, RES, ..., RES, RES. Row 3: RES, RES, ..., RES, RES, ..., RES, RES. Row 4: PSI, RES, ..., RES, RES, ..., RES, RES. The OPUk overhead is shown in the first two columns (15 and 16). The OPUk payload is shown in the remaining columns (17 to 3824). The PSI (Payload Structure Identifier) is shown in the first column of the OPUk overhead, with a sub-structure: PT (Payload Type) at bit 0, CSF (Client Signal Fail) at bit 1, and RES (Reserved) at bits 2-255. The GFP frame is shown as a 4-byte header followed by 4-65535 bytes of payload. The GFP idle frame is shown as a 4-byte header followed by 4 bytes of payload.](a63c7eab8da2ec07cbb94399fd60fc62_img.jpg)
+
+Figure 17-6: OPUk frame structure and mapping of GFP frames into OPUk. The diagram shows the OPUk frame structure with 4 rows and columns 15 to 3824. Row 1: RES, RES, ..., RES, RES, ..., RES, RES. Row 2: RES, RES, ..., RES, RES, ..., RES, RES. Row 3: RES, RES, ..., RES, RES, ..., RES, RES. Row 4: PSI, RES, ..., RES, RES, ..., RES, RES. The OPUk overhead is shown in the first two columns (15 and 16). The OPUk payload is shown in the remaining columns (17 to 3824). The PSI (Payload Structure Identifier) is shown in the first column of the OPUk overhead, with a sub-structure: PT (Payload Type) at bit 0, CSF (Client Signal Fail) at bit 1, and RES (Reserved) at bits 2-255. The GFP frame is shown as a 4-byte header followed by 4-65535 bytes of payload. The GFP idle frame is shown as a 4-byte header followed by 4 bytes of payload.
+
+G.709-Y.1331(16)\_F17-6
+
+Figure 17-6 – OPUk frame structure and mapping of GFP frames into OPUk
+
+GFP frames arrive as a continuous bit stream with a capacity that is identical to the OPUk payload area, due to the insertion of idle frames at the GFP encapsulation stage. The GFP frame stream is scrambled during encapsulation.
+
+NOTE 1 – There is no rate adaptation or scrambling required at the mapping stage; this is performed by the GFP encapsulation process.
+
+The OPUk overhead for the GFP mapping consists of a payload structure identifier (PSI) including the payload type (PT), a client signal fail (CSF) indicator and 254 bytes plus 7 bits reserved for future international standardization (RES), and seven bytes reserved for future international standardization (RES). The CSF indicator should be used only for Ethernet private line type 1 services; for other packet clients the CSF bit is fixed to 0.
+
+The OPUk payload for the GFP mapping consists of  $4 \times 3808$  bytes.
+
+NOTE 2 – The OPUflex(GFP) bit rate may be any configured bit rate as specified in Tables 7-3 and 7-8.
+
+#### 17.4.1 Mapping of GFP frames into an extended OPU2 payload area
+
+The mapping of generic framing procedure (GFP) frames in an extended OPU2 payload area is performed by aligning the byte structure of every GFP frame with the byte structure of the extended
+
+OPU2 payload (see Figure 17-7). Since the GFP frames are of variable length (the mapping does not impose any restrictions on the maximum frame length), a frame may cross the OPU2 frame boundary.
+
+![Figure 17-7: OPU2 frame structure and mapping of GFP frames into an extended OPU2 payload area. The diagram shows a large OPU2 frame with 3824 columns and 4 rows. Row 1, columns 15-16 are OPU OH used for payload data. Row 4, column 15 is PSI. The rest of the frame is the 'Extended OPU2 payload'. A callout for the PSI shows its internal structure: PT (Payload Type) at bit 0, CSF (Client Signal Fail) at bit 1, and RES (Reserved) for bits 2-255. Below the payload area, a 'GFP frame' is shown with a 4-byte header and 4-65535 bytes of data. A 'GFP idle frame' is shown as a 4-byte block. The diagram is labeled G.709-Y.1331(12)_F17-7.](6f46eccb86e008f8bc7af8ea3ab806a7_img.jpg)
+
+Figure 17-7: OPU2 frame structure and mapping of GFP frames into an extended OPU2 payload area. The diagram shows a large OPU2 frame with 3824 columns and 4 rows. Row 1, columns 15-16 are OPU OH used for payload data. Row 4, column 15 is PSI. The rest of the frame is the 'Extended OPU2 payload'. A callout for the PSI shows its internal structure: PT (Payload Type) at bit 0, CSF (Client Signal Fail) at bit 1, and RES (Reserved) for bits 2-255. Below the payload area, a 'GFP frame' is shown with a 4-byte header and 4-65535 bytes of data. A 'GFP idle frame' is shown as a 4-byte block. The diagram is labeled G.709-Y.1331(12)\_F17-7.
+
+**Figure 17-7 – OPU2 frame structure and mapping of GFP frames into an extended OPU2 payload area**
+
+GFP frames arrive as a continuous bit stream with a capacity that is identical to the OPU2 payload area, due to the insertion of GFP-idle frames at the GFP encapsulation stage. The GFP frame stream is scrambled during encapsulation.
+
+NOTE – There is no rate adaptation or scrambling required at the mapping stage; this is performed by the GFP encapsulation process.
+
+The OPU2 overhead for the GFP mapping consists of a payload structure identifier (PSI) including the payload type (PT), a client signal fail (CSF) indicator and 254 bytes plus 7 bits of reserved for future international standardization (RES).
+
+The extended OPU2 payload for the GFP mapping consists of  $4 \times 3808$  bytes from the OPU2 payload plus 7 bytes from the OPU2 overhead.
+
+## 17.5 Mapping of test signal into OPU
+
+### 17.5.1 Mapping of a NULL client into OPU
+
+An OPU payload signal with an all-0s pattern (see Figure 17-8) is defined for test purposes. This is referred to as the NULL client.
+
+![Figure 17-8: OPU frame structure and mapping of a NULL client into OPU. The diagram shows an OPU frame with 3824 columns and 4 rows. Rows 1-3, columns 15-16 are RES (Reserved). Row 4, column 15 is PSI and column 16 is RES. The main payload area is labeled 'All-0s pattern'. Below the frame, a callout for the PSI shows PT (Payload Type) at bit 0 and RES (Reserved) for bits 1-255. The payload area is labeled 'OPU payload (4 x 3808 bytes)'. The diagram is labeled G.709-Y.1331(16)_F17-8.](b44a429660cbf47740ee6777db90e34f_img.jpg)
+
+Figure 17-8: OPU frame structure and mapping of a NULL client into OPU. The diagram shows an OPU frame with 3824 columns and 4 rows. Rows 1-3, columns 15-16 are RES (Reserved). Row 4, column 15 is PSI and column 16 is RES. The main payload area is labeled 'All-0s pattern'. Below the frame, a callout for the PSI shows PT (Payload Type) at bit 0 and RES (Reserved) for bits 1-255. The payload area is labeled 'OPU payload (4 x 3808 bytes)'. The diagram is labeled G.709-Y.1331(16)\_F17-8.
+
+**Figure 17-8 – OPU frame structure and mapping of a NULL client into OPU**
+
+The OPU overhead for the NULL mapping consists of a payload structure identifier (PSI) including the payload type (PT) and 255 bytes reserved for future international standardization (RES), and seven bytes reserved for future international standardization (RES).
+
+The OPU payload for the NULL mapping consists of  $4 \times 3808$  bytes.
+
+The OPUk contains one instance of the NULL client. The OPUCn contains n instances of the NULL client, numbered 1 to n.
+
+### 17.5.2 Mapping of PRBS test signal into OPU
+
+For end-to-end and segment turn-up test purposes, a  $2^{31} - 1$  2 147 483 647-bit pseudo-random test sequence as specified in clause 5.8 of [ITU-T O.150] can be mapped into the OPU payload. Groups of eight successive bits of the 2 147 483 647-bit pseudo-random test sequence signal are mapped into 8 data bits (8D) (i.e., one byte) of the OPU payload (see Figure 17-9).
+
+![Figure 17-9: OPU frame structure and mapping of 2 147 483 647-bit pseudo-random test sequence into OPU. The diagram shows a table of OPU frames 1 to 4, with columns for bytes 15, 16, 17, 18, and 3824. Rows 1-3 show RES, RES, 8D, 8D, 3805 x 8D, 8D. Row 4 shows PSI, RES, 8D, 8D, 3805 x 8D, 8D. Below the table, a diagram shows the OPU OH (bytes 15-18) and OPU payload (4 x 3808 bytes). The OPU OH is expanded to show bytes 0 (PT), 1 (RES), and 255 (RES). The OPU payload is shown as a series of 8D blocks. The text 'case of OPU OH #1' and 'case of OPU OH #2 to #n' are shown next to the PT and RES bytes respectively. The reference G.709-Y.1331(16)_F17-9 is shown in the bottom right.](796d2e601722450d6456085e0a801e1e_img.jpg)
+
+|   | 15  | 16  | 17 | 18 | .....     | 3824 |
+|---|-----|-----|----|----|-----------|------|
+| 1 | RES | RES | 8D | 8D | 3805 × 8D | 8D   |
+| 2 | RES | RES | 8D | 8D | 3805 × 8D | 8D   |
+| 3 | RES | RES | 8D | 8D | 3805 × 8D | 8D   |
+| 4 | PSI | RES | 8D | 8D | 3805 × 8D | 8D   |
+
+OPU OH (bytes 15-18) | OPU payload (4 × 3808 bytes)
+
+OPU OH expansion:  
+ 0: PT (case of OPU OH #1)  
+ 1: RES (case of OPU OH #2 to #n)  
+ ...  
+ 255: RES
+
+G.709-Y.1331(16)\_F17-9
+
+Figure 17-9: OPU frame structure and mapping of 2 147 483 647-bit pseudo-random test sequence into OPU. The diagram shows a table of OPU frames 1 to 4, with columns for bytes 15, 16, 17, 18, and 3824. Rows 1-3 show RES, RES, 8D, 8D, 3805 x 8D, 8D. Row 4 shows PSI, RES, 8D, 8D, 3805 x 8D, 8D. Below the table, a diagram shows the OPU OH (bytes 15-18) and OPU payload (4 x 3808 bytes). The OPU OH is expanded to show bytes 0 (PT), 1 (RES), and 255 (RES). The OPU payload is shown as a series of 8D blocks. The text 'case of OPU OH #1' and 'case of OPU OH #2 to #n' are shown next to the PT and RES bytes respectively. The reference G.709-Y.1331(16)\_F17-9 is shown in the bottom right.
+
+**Figure 17-9 – OPU frame structure and mapping of 2 147 483 647-bit pseudo-random test sequence into OPU**
+
+The OPU overhead for the PRBS mapping consists of a payload structure identifier (PSI) including the payload type (PT) and 255 bytes reserved for future international standardization (RES), and seven bytes reserved for future international standardization (RES).
+
+The OPU payload for the PRBS mapping consists of  $4 \times 3808$  bytes.
+
+The OPUk contains one instance of the 2 147 483 647-bit pseudo-random test sequence. The OPUCn contains n instances of the 2 147 483 647-bit pseudo-random test sequence, numbered 1 to n.
+
+NOTE – This PRBS test pattern is not intended to be deployed for stress testing of the physical interface.
+
+### 17.6 Mapping of a non-specific client bit stream into OPUk
+
+In addition to the mappings of specific client signals as specified in the other subclauses of this clause, a non-specific client mapping into OPUk is specified. Any (set of) client signal(s), which after encapsulation into a continuous bit stream with a bit rate of the OPUk payload, can be mapped into the OPUk payload (see Figure 17-10). The bit stream must be synchronous with the OPUk signal. Any justification must be included in the continuous bit stream creation process. The continuous bit stream must be scrambled before mapping into the OPUk payload.
+
+![Figure 17-10: OPUk frame structure for the mapping of a synchronous constant bit stream. The diagram shows a grid of columns (15, 16, 17, 18, ..., 3824) and rows (1, 2, 3, 4). Rows 1-3 contain CS (Client Specific) overhead in columns 15 and 16. Row 4 contains PSI (Payload Structure Identifier) in column 15 and CS in column 16. The rest of the frame is the OPUk payload (4 x 3808 bytes). A callout box for the PSI shows its internal structure: PT (Payload Type) at row 0, and RES (Reserved) from row 1 to 255.](b3335932702b8668e62791e9fd12c9ff_img.jpg)
+
+Figure 17-10: OPUk frame structure for the mapping of a synchronous constant bit stream. The diagram shows a grid of columns (15, 16, 17, 18, ..., 3824) and rows (1, 2, 3, 4). Rows 1-3 contain CS (Client Specific) overhead in columns 15 and 16. Row 4 contains PSI (Payload Structure Identifier) in column 15 and CS in column 16. The rest of the frame is the OPUk payload (4 x 3808 bytes). A callout box for the PSI shows its internal structure: PT (Payload Type) at row 0, and RES (Reserved) from row 1 to 255.
+
+G.709-Y.1331(16)\_F17-10
+
+**Figure 17-10 – OPUk frame structure for the mapping of a synchronous constant bit stream**
+
+The OPUk overhead for the mapping consists of a payload structure identifier (PSI) including the payload type (PT) and 255 bytes reserved for future international standardization (RES), and seven bytes for client-specific (CS) purposes. The definition of these CS overhead bytes is performed within the encapsulation process specification.
+
+The OPUk payload for this non-specific mapping consists of  $4 \times 3808$  bytes.
+
+### 17.6.1 Mapping bit stream with octet timing into OPUk
+
+If octet timing is available, each octet of the incoming data stream will be mapped into a data byte (octet) of the OPUk payload.
+
+### 17.6.2 Mapping bit stream without octet timing into OPUk
+
+If octet timing is not available, groups of eight successive bits (not necessarily an octet) of the incoming data stream will be mapped into a data byte (octet) of the OPUk payload.
+
+## 17.7 Mapping of other constant bit-rate signals with justification into OPUk
+
+Mapping of other CBR client signals (with up to  $\pm 100$  ppm bit-rate tolerance) into an OPUk ( $k = 0, 1, 2, 3, 4$ ) is performed by the generic mapping procedure as specified in Annex D.
+
+During a signal fail condition of the incoming CBR client signal (e.g., in the case of a loss of input signal), this failed incoming signal is replaced by the appropriate replacement signal as defined in the clauses hereafter.
+
+During a signal fail condition of the incoming ODUk/OPUk signal (e.g., in the case of an ODUk-AIS, ODUk-LCK, ODUk-OCI condition), the failed client signal is replaced by the appropriate replacement signal as defined in the clauses hereafter.
+
+The OPUk overhead for this mapping consists of a:
+
+- payload structure identifier (PSI) including the payload type (PT) as specified in Table 15-9, the client signal fail (CSF) and 254 bytes plus 7 bits reserved for future international standardization (RES);
+- three justification control (JC1, JC2, JC3) bytes carrying the value of GMP overhead  $C_m$ ;
+- three justification control (JC4, JC5, JC6) bytes carrying the value of GMP overhead  $\sum C_n D$  and
+- one byte reserved for future international standardization (RES).
+
+The JC1, JC2 and JC3 bytes consist of a 14-bit  $C_m$  field (bits C1, C2, ..., C14), a 1-bit Increment Indicator (II) field, a 1-bit Decrement Indicator (DI) field and an 8-bit CRC-8 field which contains an error check code over the JC1, JC2 and JC3 fields.
+
+The JC4, JC5 and JC6 bytes consist of a 10-bit  $\Sigma C_{nD}$  field (bits D1, D2, ..., D10), a 5-bit CRC-5 field which contains an error check code over the bits 4 to 8 in the JC4, JC5 and JC6 fields and nine bits reserved for future international standardization (RES). The default value of  $n$  in  $\Sigma C_{nD}$  is 8. The support for  $n=1$  is client dependent and specified in the clauses hereafter when required.
+
+The values of  $m$ ,  $C_{m,min}$ ,  $C_{m,max}$ ,  $n$ ,  $C_{n,min}$  and  $C_{n,max}$  for CBR client into OPUk are as follows:
+
+$$m = 8,16,64,256,640 \quad (17-1)$$
+
+$$c_{m,nom} = \left( \frac{CBR\_nom\_client\_bit\_rate \times Number\_of\_GMP\_blocks\_in\_OPUk}{OPUk\_nom\_bit\_rate} \right) \quad (17-2)$$
+
+$$c_{m,min} = c_{m,nom} \times \left( \frac{1 - CBR\_client\_bit\_rate\_tolerance}{1 + OPUk\_bit\_rate\_tolerance} \right) \quad (17-3)$$
+
+$$c_{m,max} = c_{m,nom} \times \left( \frac{1 + CBR\_client\_bit\_rate\_tolerance}{1 - OPUk\_bit\_rate\_tolerance} \right) \quad (17-4)$$
+
+$$C_{m,min} = floor(c_{m,min}) \quad (17-5)$$
+
+$$C_{m,max} = ceiling(c_{m,max}) \quad (17-6)$$
+
+$$n = 8,1 \quad (17-7)$$
+
+$$c_{n,nom} = \left( \frac{CBR\_client\_nom\_bit\_rate \times Number\_of\_GMP\_blocks\_in\_OPUk}{OPUk\_nom\_bit\_rate} \right) \quad (17-8)$$
+
+$$c_{n,min} = c_{n,nom} \times \left( \frac{1 - CBR\_client\_bit\_rate\_tolerance}{1 + OPUk\_bit\_rate\_tolerance} \right) \quad (17-9)$$
+
+$$c_{n,max} = c_{n,nom} \times \left( \frac{1 + CBR\_client\_bit\_rate\_tolerance}{1 - OPUk\_bit\_rate\_tolerance} \right) \quad (17-10)$$
+
+$$C_{n,min} = floor(c_{n,min}) \quad (17-11)$$
+
+$$C_{n,max} = ceiling(c_{n,max}) \quad (17-12)$$
+
+$C_{m,min}$ ,  $C_{n,min}$ ,  $C_{m,max}$  and  $C_{n,max}$  values represent the boundaries of client/OPU ppm offset combinations (i.e., min. client/max. OPU and max. client/min. OPU). In steady state, given instances of client/OPU offset combinations should not result in generated  $C_m$  and  $C_n$  values throughout this range but rather should be within as small a range as possible.
+
+Under transient ppm offset conditions (e.g., AIS to normal signal), it is possible that  $C_n$  and  $C_m$  values outside the range  $C_{n,min}$  to  $C_{n,max}$  and  $C_{m,min}$  to  $C_{m,max}$  may be generated and a GMP de-mapper should be tolerant of such occurrences. Refer to Annex D for a general description of the GMP principles.
+
+### 17.7.1 Mapping a sub-1.238 Gbit/s CBR client signal into OPU0
+
+Table 17-4 specifies the clients defined by this Recommendation and their GMP mn and  $C_{nD}$  parameter values. Table 17-5 specifies the replacement signals for those clients.
+
+The support for 1-bit timing information ( $C_1$ ) is client dependent. Clients for which the 8-bit timing information in  $C_m$  with  $m=8$  is sufficient will not deploy the ability to transport  $\Sigma C_{ID}$  and the  $JC4/5/6$  value will be fixed to all-0s.
+
+The OPU0 payload for this mapping consists of  $4 \times 3808$  bytes. The bytes in the OPU0 payload area are numbered from 1 to 15232. The OPU0 payload byte numbering for GMP 1-byte (8-bit) blocks is illustrated in Figure 17-11. In row 1 of the OPU0 frame the first byte will be labelled 1, the next byte will be labelled 2, etc.
+
+Groups of eight successive bits (not necessary being a byte) of the client signal are mapped into a byte of the OPU0 payload area under control of the GMP data/stuff control mechanism. Each byte in the OPU0 payload area may either carry 8 client bits, or carry 8 stuff bits. The stuff bits are set to zero.
+
+![Figure 17-11: OPU0 frame structure for the mapping of a sub-1.238 Gbit/s client signal. The diagram shows the mapping of client data into OPU0 frames. The top part shows a grid of rows and columns (15-18, ..., 3824) with labels like JC4, JC1, I, 2, JC5, JC2, 3809, 3810, JC6, JC3, 7617, 7618, PSI, RES, 11425, 11426. The bottom part shows the OPU0 OH (Overhead) and OPU0 payload (4 x 3808 bytes). The OH includes PT, PSI, RES, and JC1-JC6. The payload is divided into 14-bit C8, 10-bit Sigma C_ID, and CRC-5/8. The diagram also includes a detailed view of the OPU0 OH structure with PT, PSI, RES, and JC1-JC6 fields.](de63e4b6d8b0aa76b85e1fe3236eac27_img.jpg)
+
+The diagram illustrates the OPU0 frame structure. The top section shows a grid of rows and columns. Rows 1-4 are shown with columns 15, 16, 17, 18, and 3824. Row 1 contains JC4, JC1, I, 2, and 3808. Row 2 contains JC5, JC2, 3809, 3810, and 7616. Row 3 contains JC6, JC3, 7617, 7618, and 11424. Row 4 contains PSI, RES, 11425, 11426, and 15232. Below this, the OPU0 OH (Overhead) and OPU0 payload (4 x 3808 bytes) are shown. The OH includes PT, PSI, RES, and JC1-JC6. The payload is divided into 14-bit C8, 10-bit Sigma C\_ID, and CRC-5/8. The diagram also includes a detailed view of the OPU0 OH structure with PT, PSI, RES, and JC1-JC6 fields.
+
+Figure 17-11: OPU0 frame structure for the mapping of a sub-1.238 Gbit/s client signal. The diagram shows the mapping of client data into OPU0 frames. The top part shows a grid of rows and columns (15-18, ..., 3824) with labels like JC4, JC1, I, 2, JC5, JC2, 3809, 3810, JC6, JC3, 7617, 7618, PSI, RES, 11425, 11426. The bottom part shows the OPU0 OH (Overhead) and OPU0 payload (4 x 3808 bytes). The OH includes PT, PSI, RES, and JC1-JC6. The payload is divided into 14-bit C8, 10-bit Sigma C\_ID, and CRC-5/8. The diagram also includes a detailed view of the OPU0 OH structure with PT, PSI, RES, and JC1-JC6 fields.
+
+Figure 17-11 – OPU0 frame structure for the mapping of a sub-1.238 Gbit/s client signal
+
+Table 17-4 –  $m$ ,  $n$  and  $C_{nd}$  for sub-1.238G clients into OPU0
+
+| Client signal                               | Nominal bit rate (kbit/s)  | Bit rate tolerance (ppm) | $m$ | $n$ | $C_{nd}$ |
+|---------------------------------------------|----------------------------|--------------------------|-----|-----|----------|
+| Transcoded 1000BASE-X (see clause 17.7.1.1) | $15/16 \times 1\,250\,000$ | $\pm 100$                | 8   | 8   | No       |
+| STM-1                                       | 155 520                    | $\pm 20$                 | 8   | 1   | Yes      |
+| STM-4                                       | 622 080                    | $\pm 20$                 | 8   | 1   | Yes      |
+| FC-100                                      | 1 062 500                  | $\pm 100$                | 8   | 8   | No       |
+| SBCON/ESCON                                 | 200 000                    | $\pm 200$                | 8   | 8   | No       |
+| DVB-ASI                                     | 270 000                    | $\pm 100$                | 8   | 8   | No       |
+| SDI                                         | 270 000                    | $\pm 2.8$                | 8   | TBD | TBD      |
+
+**Table 17-5 – Replacement signal for sub-1.238G clients**
+
+| Client signal | Replacement signal | Bit-rate tolerance (ppm) |
+|---------------|--------------------|--------------------------|
+| STM-1         | Generic-AIS        | ±20                      |
+| STM-4         | Generic-AIS        | ±20                      |
+| 1000BASE-X    | Link Fault         | ±100                     |
+| FC-100        | NOS                | ±100                     |
+| SBCON/ESCON   | NOS                | ±200                     |
+| DVB-ASI       | Generic-AIS        | ±100                     |
+| SDI           | Generic-AIS        | For further study        |
+
+### 17.7.1.1 1000BASE-X transcoding
+
+The 1000BASE-X signal (8B/10B coded, nominal bit rate of 1 250 000 kbit/s and a bit-rate tolerance up to ±100 ppm) is synchronously mapped into a 75-octet GFP-T frame stream with a bit rate of  $15/16 \times 1\,250\,000\text{ kbit/s} \pm 100\text{ ppm}$  (approximately 1 171 875 kbit/s ±100 ppm). This process is referred to as "timing transparent transcoding (TTT)". The  $15/16 \times 1\,250\,000\text{ kbit/s} \pm 100\text{ ppm}$  signal is then mapped into an OPU0 by means of the generic mapping procedure as specified in clause 17.7.1 and Annex D.
+
+For 1000BASE-X client mapping, 1-bit timing information ( $C_1$ ) is not needed, so OPU0 JC4/JC5/JC6 OH value will be fixed to all-0s.
+
+The mapping of the 1000BASE-X signal into GFP-T is performed as specified in [ITU-T G.704] with the following parameters:
+
+- Each GFP-T frame contains one superblock
+- The 65B\_PAD character is not used
+- GFP idle frames are not used
+- The GFP frame pFCS is not used.
+
+During a signal fail condition of the incoming 1000BASE-X client signal (e.g., in the case of a loss of input signal), either:
+
+- This failed incoming 1000BASE-X signal is replaced by a stream of 10B blocks, with a bit rate of  $1\,250\,000\text{ kbit/s} \pm 100\text{ ppm}$ , each carrying a link fault indication as specified in [IEEE 802.3], which stream is then applied at the GFP-T mapper, or
+- The GFP-T signal is replaced by a stream of GFP client signal fail (CSF) and GFP-idle frames as specified in [ITU-T G.704] with a bit rate of  $15/16 \times 1\,250\,000\text{ kbit/s} \pm 100\text{ ppm}$ .
+
+During either
+
+- A signal fail condition of the incoming ODU0/OPU0 signal (e.g., in the case of an ODU0-AIS, ODU0-LCK, ODU0-OCI condition), or
+- Incoming CSF frames as specified in [ITU-T G.704].
+
+The GFP-T de-mapper process generates a stream of 10B blocks, with each block carrying a link fault indication as specified in [IEEE 802.3] as a replacement signal for the lost 1000BASE-X signal.
+
+NOTE – The Ethernet link fault indication is a stream of repeating /C1/C2/C1/C2/ ... ordered sets, where  $C_1 = /K28.5/D21.5/D0.0/D0.0/$  and  $C_2 = /K28.5/D2.2/D0.0/D0.0/$ . This character stream is then processed by the GFP-T mapper process in the same manner as if it were the received 8B/10B data stream, mapping it into GFP-T superblocks for transmission.
+
+### 17.7.1.2 FC-100
+
+During a signal fail condition of the incoming FC-100 signal (e.g., in the case of a loss of input signal), this failed incoming FC-100 signal is replaced by an NOS primitive sequence as specified in [b-INCITS 470].
+
+NOTE – The NOS primitive sequence ordered set is defined as /K28.5/D21.2/D31.5/D5.2/.
+
+During a signal fail condition of the incoming ODU0 signal (e.g., in the case of an ODU0-AIS, ODU0-LCK, ODU0-OCI condition), NOS primitive sequence ordered sets as specified in [b-INCITS 470] are generated as a replacement signal for the lost FC-100 signal.
+
+### 17.7.1.3 SBCON/ESCON
+
+During a signal fail condition of the incoming SBCON/ESCON signal (e.g., in the case of a loss of input signal), this failed incoming SBCON/ESCON signal is replaced by an NOS sequence as specified in [b-ANSI INCITS 296].
+
+NOTE – The NOS sequence ordered set is defined as /K28.5/D0.2/.
+
+During a signal fail condition of the incoming ODU0 signal (e.g., in the case of an ODU0-AIS, ODU0-LCK, ODU0-OCI condition), NOS sequence ordered sets as specified in [b-ANSI INCITS 296] are generated as a replacement signal for the lost SBCON/ESCON signal.
+
+## 17.7.2 Mapping a supra-1.238 to sub-2.488 Gbit/s CBR client signal into OPU1
+
+Table 17-6 specifies the clients defined by this Recommendation and their GMP m, n and  $C_{nd}$  parameter values. Table 17-7 specifies the replacement signals for those clients.
+
+The support for 8-bit timing information ( $\Sigma C_{8D}$ ) in the OPU1 JC4/JC5/JC6 OH is required.
+
+The support for 1-bit timing information ( $\Sigma C_{1D}$ ) in the OPU1 JC4/JC5/JC6 OH is client dependent.
+
+The OPU1 payload for this mapping consists of  $4 \times 3808$  bytes. The groups of 2 bytes in the OPU1 payload area are numbered from 1 to 7616. The OPU1 payload byte numbering for GMP 2-byte (16-bit) blocks is illustrated in Figure 17-12. In row 1 of the OPU1 frame the first 2-bytes will be labelled 1, the next 2-bytes will be labelled 2, etc.
+
+Groups of sixteen successive bits of the client signal are mapped into a group of 2 successive bytes of the OPU1 payload area under control of the GMP data/stuff control mechanism. Each group of 2 bytes in the OPU1 payload area may either carry 16 client bits, or carry 16 stuff bits. The stuff bits are set to zero.
+
+![Figure 17-12: OPU1 frame structure for the mapping of a supra-1.238 to sub-2.488 Gbit/s client signal. The diagram shows a grid of columns (15-20, ..., 3823-3824) and rows (1-4). Row 1 contains JC4, JC1, 1, 1, 2, 2, ..., 1904, 1904. Row 2 contains JC5, JC2, 1905, 1905, 1906, 1906, ..., 3808, 3808. Row 3 contains JC6, JC3, 3809, 3809, 3810, 3810, ..., 5712, 5712. Row 4 contains PSI, RES, 5713, 5713, 5714, 5714, ..., 7616, 7616. Below the grid, the OPU1 OH (Overhead) is shown, including PSI (PSI 0: PT, PSI 1: RES, PSI 2: C, ..., PSI 255: RES). The OPU1 payload (4 x 3808 bytes) is shown, containing JC1, JC2, JC3, JC4, JC5, JC6, and various data fields (C1-C8, C9-C14, II, DI, CRC-8, RES, D1-D10, CRC-5). Annotations include '14-bit C16', 'Decrement indicator', 'Increment indicator', and '10-bit ΣCND'.](21ea5add6a61cc951b5c43ddffefb3ff_img.jpg)
+
+Figure 17-12: OPU1 frame structure for the mapping of a supra-1.238 to sub-2.488 Gbit/s client signal. The diagram shows a grid of columns (15-20, ..., 3823-3824) and rows (1-4). Row 1 contains JC4, JC1, 1, 1, 2, 2, ..., 1904, 1904. Row 2 contains JC5, JC2, 1905, 1905, 1906, 1906, ..., 3808, 3808. Row 3 contains JC6, JC3, 3809, 3809, 3810, 3810, ..., 5712, 5712. Row 4 contains PSI, RES, 5713, 5713, 5714, 5714, ..., 7616, 7616. Below the grid, the OPU1 OH (Overhead) is shown, including PSI (PSI 0: PT, PSI 1: RES, PSI 2: C, ..., PSI 255: RES). The OPU1 payload (4 x 3808 bytes) is shown, containing JC1, JC2, JC3, JC4, JC5, JC6, and various data fields (C1-C8, C9-C14, II, DI, CRC-8, RES, D1-D10, CRC-5). Annotations include '14-bit C16', 'Decrement indicator', 'Increment indicator', and '10-bit ΣCND'.
+
+Figure 17-12 – OPU1 frame structure for the mapping of a supra-1.238 to sub-2.488 Gbit/s client signal
+
+Table 17-6 –  $C_m$  ( $m=16$ ) for supra-1.238 to sub-2.488G clients into OPU1
+
+| Client signal | Nominal bit rate (kbit/s) | Bit-rate tolerance (ppm) | m  | n   | $C_{nD}$ |
+|---------------|---------------------------|--------------------------|----|-----|----------|
+| FC-200        | 2 125 000                 | ±100                     | 16 | 8   | Yes      |
+| 1.5G SDI      | 1 485 000                 | ±10                      | 16 | TBD | Yes      |
+| 1.5G SDI      | 1 485 000/1.001           | ±10                      | 16 | TBD | Yes      |
+
+Table 17-7 – Replacement signal for supra-1.238 to sub-2.488 Gbit/s clients
+
+| Client signal | Replacement signal | Bit-rate tolerance (ppm) |
+|---------------|--------------------|--------------------------|
+| FC-200        | NOS                | ±100                     |
+| 1.5G SDI      | Generic-AIS        | For further study        |
+
+### 17.7.2.1 FC-200
+
+During a signal fail condition of the incoming FC-200 signal (e.g., in the case of a loss of input signal), this failed incoming FC-200 signal is replaced by an NOS primitive sequence as specified in [b-INCITS 470].
+
+NOTE – The NOS primitive sequence ordered set is defined as /K28.5/D21.2/D31.5/D5.2/.
+
+During a signal fail condition of the incoming ODU1 signal (e.g., in the case of an ODU1-AIS, ODU1-LCK, ODU1-OCI condition), NOS primitive sequence ordered sets as specified in [b-INCITS 470] are generated as a replacement signal for the lost FC-200 signal.
+
+### 17.7.3 Mapping CBR client signals into OPU2
+
+Table 17-8 specifies the clients defined by this Recommendation and their GMP  $m$ ,  $n$  and  $C_{nD}$  parameter values. Table 17-9 specifies the replacement signals for those clients.
+
+The support for 8-bit timing information ( $\Sigma C_{8D}$ ) in the OPU2 JC4/JC5/JC6 OH is required.
+
+The support for 1-bit timing information ( $\Sigma C_{1D}$ ) in the OPU2 JC4/JC5/JC6 OH is client dependent.
+
+The OPU2 payload for this mapping consists of  $4 \times 3808$  bytes. The groups of eight bytes in the OPU2 payload area are numbered from 1 to 1904. The OPU2 payload byte numbering for GMP 8-byte (64-bit) blocks is illustrated in Figure 17-13. In row 1 of the OPU2 frame the first 8-bytes will be labelled 1, the next 8-bytes will be labelled 2, etc.
+
+Groups of sixty-four successive bits of the client signal are mapped into a group of eight successive bytes of the OPU2 payload area under control of the GMP data/stuff control mechanism. Each group of eight bytes in the OPU2 payload area may either carry 64 client bits, or carry 64 stuff bits. The stuff bits are set to zero.
+
+![Figure 17-13: OPU2 frame structure for the mapping of a CBR client signal. The diagram shows the OPU2 frame layout with columns 15 to 3824 and rows 1 to 4. Row 1 contains JC4, JC1, I, I, 2, 2, 476, 476. Row 2 contains JC5, JC2, 477, 477, 478, 478, 952, 952. Row 3 contains JC6, JC3, 953, 953, 954, 954, 1428, 1428. Row 4 contains PSI, RES, 1429, 1429, 1430, 1430, 1904, 1904. Below the frame layout, a detailed view of the OPU2 OH and payload is shown. The OPU2 OH includes PSI (PT, CSF, RES) and JC1-JC6. The payload is divided into 4 x 3808 bytes. A detailed view of the payload shows 8-byte blocks (1-8) containing client data (C1-C14, II, DI) and control information (JC1, JC2, JC3, CRC-8, JC4, JC5, JC6, RES, D1-D10, CRC-5). Labels include 14-bit C64, Decrement indicator, Increment indicator, and 10-bit Sigma Cnd.](a0eb8d30ac11ba97b2733c187b89ff22_img.jpg)
+
+Figure 17-13: OPU2 frame structure for the mapping of a CBR client signal. The diagram shows the OPU2 frame layout with columns 15 to 3824 and rows 1 to 4. Row 1 contains JC4, JC1, I, I, 2, 2, 476, 476. Row 2 contains JC5, JC2, 477, 477, 478, 478, 952, 952. Row 3 contains JC6, JC3, 953, 953, 954, 954, 1428, 1428. Row 4 contains PSI, RES, 1429, 1429, 1430, 1430, 1904, 1904. Below the frame layout, a detailed view of the OPU2 OH and payload is shown. The OPU2 OH includes PSI (PT, CSF, RES) and JC1-JC6. The payload is divided into 4 x 3808 bytes. A detailed view of the payload shows 8-byte blocks (1-8) containing client data (C1-C14, II, DI) and control information (JC1, JC2, JC3, CRC-8, JC4, JC5, JC6, RES, D1-D10, CRC-5). Labels include 14-bit C64, Decrement indicator, Increment indicator, and 10-bit Sigma Cnd.
+
+Figure 17-13 – OPU2 frame structure for the mapping of a CBR client signal
+
+Table 17-8 – m, n and  $C_{nd}$  for CBR clients into OPU2
+
+| Client signal     | Nominal bit rate (kbit/s) | Bit rate tolerance (ppm) | m | n | $C_{nd}$ |
+|-------------------|---------------------------|--------------------------|---|---|----------|
+| For further study |                           |                          |   |   |          |
+
+Table 17-9 – Replacement signal for CBR clients
+
+| Client signal     | Replacement signal | Bit-rate tolerance (ppm) |
+|-------------------|--------------------|--------------------------|
+| For further study |                    |                          |
+
+#### 17.7.4 Mapping CBR client signals into OPU3
+
+Table 17-10 specifies the clients defined by this Recommendation and their GMP m, n and  $C_{nd}$  parameter values. Table 17-11 specifies the replacement signals for those clients.
+
+The support for 8-bit timing information ( $\Sigma C_{8D}$ ) in the OPU3 JC4/JC5/JC6 OH is required.
+
+The support for 1-bit timing information ( $\Sigma C_{1D}$ ) in the OPU3 JC4/JC5/JC6 OH is client dependent.
+
+The OPU3 payload for this mapping consists of  $4 \times 3808$  bytes. The groups of 32 bytes in the OPU3 payload area are numbered from 1 to 476. The OPU3 payload byte numbering for GMP 32-byte (256-bit) blocks is illustrated in Figure 17-14. In row 1 of the OPU3 frame the first 32-bytes will be labelled 1, the next 32-bytes will be labelled 2, etc.
+
+Groups of two hundred-fifty-six successive bits of the client signal are mapped into a group of 32 successive bytes of the OPU3 payload area under control of the GMP data/stuff control mechanism. Each group of 32 bytes in the OPU3 payload area may either carry 256 client bits, or carry 256 stuff bits. The stuff bits are set to zero.
+
+![Figure 17-14: OPU3 frame structure for the mapping of a CBR client signal. The diagram shows the OPU3 frame layout with columns 15, 16, 17, 48, 49, 80, ..., 3793, 3824. Rows 1-4 show the OPU3 OH (JC4, JC1, I, I, 2, 2, 119, 119) and the OPU3 payload (4 x 3808 bytes). A detailed view of the OPU3 OH shows the PSI (PT, RES) and the JC (JC1, JC2, JC3, JC4, JC5, JC6) fields. JC1, JC2, and JC3 are 14-bit C256 fields. JC4, JC5, and JC6 are 10-bit Sigma CnD fields. JC1, JC2, and JC3 also contain CRC-8 and CRC-5 fields. The diagram also shows the mapping of client signal bits into the OPU3 payload.](d04c50badc78d5ba47bf4e352af4a754_img.jpg)
+
+Figure 17-14: OPU3 frame structure for the mapping of a CBR client signal. The diagram shows the OPU3 frame layout with columns 15, 16, 17, 48, 49, 80, ..., 3793, 3824. Rows 1-4 show the OPU3 OH (JC4, JC1, I, I, 2, 2, 119, 119) and the OPU3 payload (4 x 3808 bytes). A detailed view of the OPU3 OH shows the PSI (PT, RES) and the JC (JC1, JC2, JC3, JC4, JC5, JC6) fields. JC1, JC2, and JC3 are 14-bit C256 fields. JC4, JC5, and JC6 are 10-bit Sigma CnD fields. JC1, JC2, and JC3 also contain CRC-8 and CRC-5 fields. The diagram also shows the mapping of client signal bits into the OPU3 payload.
+
+Figure 17-14 – OPU3 frame structure for the mapping of a CBR client signal
+
+Table 17-10 – m, n and  $C_{nD}$  for CBR clients into OPU3
+
+| Client signal                              | Nominal bit rate (kbit/s)                    | Bit rate tolerance (ppm) | m   | n | $C_{nD}$ |
+|--------------------------------------------|----------------------------------------------|--------------------------|-----|---|----------|
+| Transcoded 40GBASE-R (see clause 17.7.4.1) | $1027/1024 \times 64/66 \times 41\,250\,000$ | $\pm 100$                | 256 | 8 | Yes      |
+
+Table 17-11 – Replacement signal for CBR clients
+
+| Client signal | Replacement signal                                                                                                                             | Bit-rate tolerance (ppm) |
+|---------------|------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------|
+| 40GBASE-R     | Continuous 40GBASE-R local fault sequence ordered sets with four PCS lane alignment markers inserted after each 16383 x 4 sixty-six-bit blocks | $\pm 100$                |
+
+A 40GBASE-R local fault sequence ordered set is a 66B control block (sync header = 10) with a block type of 0x4B, an "O" code of 0x00, a value of 0x01 to indicate "local fault" in lane 3, and all of the other octets (before scrambling) equal to 0x00.
+
+#### 17.7.4.1 40GBASE-R multi-lane processing and transcoding
+
+The 40GBASE-R client signal (64B/66B encoded, nominal aggregate bit-rate of 41 250 000 kbit/s,  $\pm 100$  ppm) is recovered using the process described in Annex E for parallel 64B/66B interfaces. The lane(s) of the physical interface are bit-disinterleaved, if necessary, into four streams of 10 312 500 kbit/s. 66B block lock and lane alignment marker lock are acquired on each PCS lane, allowing the 66B blocks to be de-skewed and reordered.
+
+The resulting sequence is descrambled and transcoded according to the process described in Annex B into 513B code blocks. Each pair of two 513B code blocks is combined according to the process described in Annex F into a 1027B block, resulting in a bit stream of  $1027/1024 \times 40\,000\,000$  kbit/s  $\pm 100$  ppm (40,117,187.500 kbit/s  $\pm 100$  ppm). This process is referred to as "timing transparent transcoding (TTT)", mapping a bit stream which is  $1027/1056$  times the bit-rate of the aggregate Ethernet signal.
+
+In the mapper, the received Ethernet PCS lane BIP may be compared with the expected Ethernet PCS lane BIP as a non-intrusive monitor.
+
+The de-mapper will insert a compensated Ethernet PCS lane BIP as described in Annex E. In addition, as described in Annex E, the combined error mask resulting from the PCS BIP-8 error mask and the OTN BIP-8 error mask may be used as a non-intrusive monitor.
+
+For 40GBASE-R client mapping, 1-bit timing information ( $C_1$ ) is not needed.
+
+The de-mapper will recover from the output of the GMP processor 1027B block lock, and then trans-decode each 1027B block to sixteen 66B blocks as described in Annex E. Trans-decoded lane alignment markers are constructed with a compensated BIP-8. The 66B blocks are then re-distributed round-robin to PCS lanes. If the number of PCS lanes is greater than the number of physical lanes of the egress interface, the appropriate numbers of PCS lanes are bit-multiplexed onto the physical lanes of the egress interface.
+
+#### 17.7.5 Mapping CBR client signals into OPU4
+
+Table 17-12 specifies the clients defined by this Recommendation and their GMP  $m$ ,  $n$  and  $C_{nd}$  parameter values. Table 17-13 specifies the replacement signals for those clients.
+
+The support for 8-bit timing information ( $\Sigma C_{8D}$ ) in the OPU4 JC4/JC5/JC6 OH is required.
+
+The support for 1-bit timing information ( $\Sigma C_{1D}$ ) in the OPU4 JC4/JC5/JC6 OH is client dependent.
+
+The OPU4 payload for this mapping consists of  $4 \times 3800$  bytes for client data and  $4 \times 8$  bytes with fixed stuff. The groups of 80 bytes in the OPU4 payload area are numbered from 1 to 190. The OPU4 payload byte numbering for GMP 80-byte (640-bit) blocks is illustrated in Figure 17-15. In row 1 of the OPU4 frame the first 80-bytes will be labelled 1, the next 80-bytes will be labelled 2, etc.
+
+Groups of six hundred and forty successive bits of the client signal are mapped into a group of 80 successive bytes of the OPU4 payload area under control of the GMP data/stuff control mechanism. Each group of 80 bytes in the OPU4 payload area may either carry 640 client bits, or carry 640 stuff bits. The stuff bits are set to zero.
+
+![Figure 17-15 – OPU4 frame structure for the mapping of a CBR client signal. The diagram illustrates the OPU4 frame layout across 4 rows and columns 15 to 3824. Columns 15 and 16 contain OPU4 Overhead (OH) bytes: JC4, JC1 in row 1; JC5, JC2 in row 2; JC6, JC3 in row 3; and PSI, RES in row 4. Columns 17 to 3816 contain the OPU4 payload (4 x 3800 bytes), with specific byte indices shown (e.g., 1, 48, 49, 95, 96, 143, 144, 190). Columns 3817 to 3824 are designated as OPU4 fixed stuff (4 x 8 bytes). Detailed mapping of the overhead bytes is shown: JC1-JC3 mapping includes a 14-bit C640 value (C1-C14), an Increment Indicator (II), a Decrement Indicator (DI), and an 8-bit CRC (CRC-8). JC4-JC6 mapping includes Reserved (RES) bits, a 10-bit sum of Cnd (D1-D10), and a 5-bit CRC (CRC-5). The Payload Structure Identifier (PSI) is also detailed as a 256-byte structure containing PT, CSF, and RES fields.](301f4a188198a15b1415d54545b07e0d_img.jpg)
+
+Figure 17-15 – OPU4 frame structure for the mapping of a CBR client signal. The diagram illustrates the OPU4 frame layout across 4 rows and columns 15 to 3824. Columns 15 and 16 contain OPU4 Overhead (OH) bytes: JC4, JC1 in row 1; JC5, JC2 in row 2; JC6, JC3 in row 3; and PSI, RES in row 4. Columns 17 to 3816 contain the OPU4 payload (4 x 3800 bytes), with specific byte indices shown (e.g., 1, 48, 49, 95, 96, 143, 144, 190). Columns 3817 to 3824 are designated as OPU4 fixed stuff (4 x 8 bytes). Detailed mapping of the overhead bytes is shown: JC1-JC3 mapping includes a 14-bit C640 value (C1-C14), an Increment Indicator (II), a Decrement Indicator (DI), and an 8-bit CRC (CRC-8). JC4-JC6 mapping includes Reserved (RES) bits, a 10-bit sum of Cnd (D1-D10), and a 5-bit CRC (CRC-5). The Payload Structure Identifier (PSI) is also detailed as a 256-byte structure containing PT, CSF, and RES fields.
+
+**Figure 17-15 – OPU4 frame structure for the mapping of a CBR client signal**
+
+**Table 17-12 – m, n and C<sub>nD</sub> for CBR clients into OPU4**
+
+| Client signal                    | Nominal bit rate (kbit/s) | Bit-rate tolerance (ppm) | m   | n | C <sub>nD</sub> |
+|----------------------------------|---------------------------|--------------------------|-----|---|-----------------|
+| <b>100GBASE-R (see 17.7.5.1)</b> | 103 125 000               | ±100                     | 640 | 8 | Yes             |
+
+**Table 17-13 – Replacement signal for CBR clients**
+
+| Client signal                    | Replacement signal                                                                                                                                                       | Bit-rate tolerance (ppm) |
+|----------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------|
+| <b>100GBASE-R (see 17.7.5.1)</b> | Continuous 66B encoded and scrambled 100GBASE-R local fault sequence ordered sets with 20 PCS lane alignment markers inserted after each 16383 x 20 sixty-six-bit blocks | ±100                     |
+
+A 66B encoded and scrambled 100GBASE-R local fault sequence ordered set is a 66B control block (sync header = 10) with a block type of 0x4B, an "O" code of 0x00, a value of 0x01 to indicate a "local fault" in lane 3, and all of the other octets (before scrambling) equal to 0x00. A self-synchronizing scrambler with generator polynomial  $1+x^{39}+x^{58}$  shall be used, which is identical to the scrambler specified in clause 49.2.6 of [IEEE 802.3].
+
+### 17.7.5.1 100GBASE-R multi-lane processing
+
+The 100GBASE-R client signal (64B/66B encoded, nominal aggregate bit-rate of 103 125 000 kbit/s ±100 ppm) is recovered using the process described in Annex E for parallel 64B/66B interfaces. The lane(s) of the physical interface are bit-disinterleaved, if necessary, into twenty streams of 5 161 250 kbit/s. 66B block lock and lane alignment marker lock are acquired on each PCS lane, allowing the 66B blocks to be de-skewed and reordered.
+
+In the mapper, the received Ethernet PCS lane BIP may be compared with the expected Ethernet PCS lane BIP as a non-intrusive monitor.
+
+The de-mapper will pass through the PCS lane BIP from the ingress as described in Annex E. In addition, the received Ethernet PCS lane BIP may be compared with the expected Ethernet PCS lane BIP as a non-intrusive monitor.
+
+For 100GBASE-R client mapping, 1-bit timing information ( $C_1$ ) is not needed.
+
+The de-mapper will recover from the output of the GMP processor 64B/66B block lock per the state diagram in Figure 82-10 [IEEE 802.3]. The 66B blocks are re-distributed round-robin to PCS lanes. If the number of PCS lanes is greater than the number of physical lanes of the egress interface, the appropriate numbers of PCS lanes are bit-multiplexed onto the physical lanes of the egress interface.
+
+## 17.8 Mapping a 1000BASE-X and FC-1200 signal via timing transparent transcoding into OPUk
+
+### 17.8.1 Mapping a 1000BASE-X signal into OPU0
+
+Refer to clause 17.7.1 for the mapping of the transcoded 1000BASE-X signal and to clause 17.7.1.1 for the transcoding of the 1000BASE-X signal.
+
+### 17.8.2 Mapping an FC-1200 signal into OPU2e
+
+The nominal line rate for FC-1200 is  $10\,518\,750\text{ kbit/s} \pm 100\text{ ppm}$ , and must therefore be compressed to a suitable rate to fit into an OPU2e.
+
+The adaptation of the 64B/66B encoded FC-1200 client is done by transcoding a group of eight 66B blocks into one 513B block (as described in Annex B), assembling eight 513B blocks into one 516-octet superblock and encapsulating seventeen 516-octet superblocks into an 8800 octet GFP frame as illustrated in Figure 17-17. The GFP frame consists of 2200 rows with 32 bits per row. The first row contains the GFP core header, the second row the GFP payload header. The next four rows contain 16 bytes reserved for future international standardization. The next seventeen times 129 rows contain the seventeen superblocks #1 to #17. The last row contains the GFP payload FCS. The flag (F) bit of 513B block #i ( $i = 0..7$ ) is carried in Flag #i bit located in the superblock flags field. The remaining 512 bits of each of the eight 513B blocks of a superblock are carried in 16 rows of the superblock data field; bits of 513B block #0 in the first 16 rows of the superblock, bits of 513B block #1 in the next 16 rows, etc. Each 513B block contains 'j' ( $j = 0..8$ ) control blocks (CB1 to CBj) and '8-j' all-data blocks (DB1..DB8-j) as specified in Annex B. Figure 17-17 presents a 513B block with three control blocks and five all-data blocks. A 513B block may contain zero to eight control blocks and a superblock may contain thus zero to sixty-four control blocks.
+
+NOTE 1 – The GFP encapsulation stage does not generate GFP-idle frames and therefore the generated GFP stream is synchronous to the FC-1200 client stream. The adaptation process performs a 50/51 rate compression, so the resulting GFP stream has a signal bit rate of  $50/51 \times 10.51875\text{ Gbit/s} \pm 100\text{ ppm}$  (i.e.,  $10\,312\,500\text{ kbit/s} \pm 100\text{ ppm}$ ).
+
+The stream of 8800 octet GFP frames is byte-synchronous mapped into the OPU2e payload by aligning the byte structure of every GFP frame with the byte structure of the OPU2e payload (see Figure 17-16). Sixty-four fixed stuff (FS) bytes are added in columns 1905 to 1920 of the OPU2e payload. All the GFP frames have the same length (8800 octets). The GFP frames are not aligned with the OPU2e payload structure and may cross the boundary between two OPU2e frames.
+
+During a signal fail condition of the incoming FC-1200 signal (e.g., in the case of a loss of input signal), this failed incoming FC-1200 signal is replaced by a stream of 66B blocks, with each block carrying two local fault sequence ordered sets as specified in [b-ANSI INCITS 364]. This replacement signal is then applied at the transcoding process.
+
+NOTE 2 – Local fault sequence ordered set is /K28.4/D0.0/D0.0/D1.0/. The 66B block contains the following value SH=10 0x55 00 00 01 00 00 00 01.
+
+During a signal fail condition of the incoming ODU2e/OPU2e signal (e.g., in the case of an ODU2e-AIS, ODU2e-LCK, ODU2e-OCI condition) a stream of 66B blocks, with each block carrying
+
+two local fault sequence ordered sets as specified in [b-ANSI INCITS 364] is generated as a replacement signal for the lost FC-1200 signal.
+
+![Figure 17-16: Mapping of transcoded FC-1200 into OPU2e. The diagram shows a table of columns (15 to 3824) and rows (1 to 4). Rows 1-3 contain RES, RES, and GFP frame #i or #i+1. Row 4 contains PSI, RES, GFP frame #i+2. Below the table, a detail shows OPU2e overhead (PT, CSF, RES) and OPU2e payload (GFP frame, 8800 bytes).](dc7f3c8b7f8859a78d5705f104504e4c_img.jpg)
+
+Figure 17-16 illustrates the mapping of transcoded FC-1200 into OPU2e. The top part shows a table of columns (15 to 3824) and rows (1 to 4). Rows 1-3 contain RES, RES, and GFP frame #i or #i+1. Row 4 contains PSI, RES, GFP frame #i+2. Below the table, a detail shows OPU2e overhead (PT, CSF, RES) and OPU2e payload (GFP frame, 8800 bytes).
+
+Figure 17-16: Mapping of transcoded FC-1200 into OPU2e. The diagram shows a table of columns (15 to 3824) and rows (1 to 4). Rows 1-3 contain RES, RES, and GFP frame #i or #i+1. Row 4 contains PSI, RES, GFP frame #i+2. Below the table, a detail shows OPU2e overhead (PT, CSF, RES) and OPU2e payload (GFP frame, 8800 bytes).
+
+Figure 17-16 – Mapping of transcoded FC-1200 into OPU2e
+
+![Figure 17-17: GFP frame format for FC-1200. The diagram shows the internal structure of a GFP frame, including PLI, cHEC, tHEC, RES, Superblock data, Superblock flags, and pFCS. It also shows the mapping of blocks and flags to transmission orders.](ba676d18b6a00f27c5bfaec9eeec20be_img.jpg)
+
+Figure 17-17 illustrates the GFP frame format for FC-1200. The diagram shows the internal structure of a GFP frame, including PLI, cHEC, tHEC, RES, Superblock data, Superblock flags, and pFCS. It also shows the mapping of blocks and flags to transmission orders.
+
+The top part shows a table of transmission orders (1 to 8) for FS, POS, and CB type. The middle part shows a table of blocks (CB1 to CB5, DB1 to DB5) and their mapping to transmission orders. The bottom part shows a table of blocks (Block #0 to Block #7) and their mapping to transmission orders.
+
+The main diagram shows the GFP frame structure:
+
+- Transmission order 1 to 8:** PLI, cHEC
+- Transmission order 1 to 8:** PTI = 000, PFI = 1, EXI = 0000, UPI = 0 x 15 (transp 10GFC), tHEC
+- Transmission order 1 to 8:** RES (16 bytes)
+- Transmission order 1 to 8:** Superblock data (512 bytes)
+- Transmission order 1 to 8:** Superblock flags, CRC-24
+- Transmission order 1 to 8:** Superblock #2 (516 bytes)
+- Transmission order 1 to 8:** Superblock #3 (516 bytes)
+- Transmission order 1 to 8:** Superblock #17 (516 bytes)
+- Transmission order 1 to 8:** pFCS (CRC-32)
+
+The right side of the diagram indicates the Superblock #1 (516 bytes) structure, which includes Superblock data (512 bytes) and Superblock flags (4 bytes).
+
+Figure 17-17: GFP frame format for FC-1200. The diagram shows the internal structure of a GFP frame, including PLI, cHEC, tHEC, RES, Superblock data, Superblock flags, and pFCS. It also shows the mapping of blocks and flags to transmission orders.
+
+Figure 17-17 – GFP frame format for FC-1200
+
+GFP framing is used to facilitate delineation of the superblock structure by the receiver. The leading flag bits from each of the eight 513B blocks are relocated into a single octet at the end of the 513-octet superblock data field (labelled "Superblock flags").
+
+To minimize the risk of incorrect decoding due to errors in the 1 to 65 octets of "control" information (Flags, FC, POS, CB\_Type), a CRC-24 is calculated over the 65 octets within each superblock that may contain such "control" information and appended to form a 516 octet superblock. The 65 octets in the 516-octet superblock over which the CRC-24 is calculated are the octets  $(1+8n)$  with  $n=0..64$  (i.e., octets 1, 9, 17, ..., 513). The generator polynomial for the CRC-24 is  $G(x) = x^{24} + x^{21} + x^{20} + x^{17} + x^{15} + x^{11} + x^9 + x^8 + x^6 + x^5 + x + 1$  with an all-ones initialization value, where  $x^{24}$  corresponds to the MSB and  $x^0$  to the LSB. This superblock CRC is generated by the source adaptation process using the following steps:
+
+- 1) The 65 octets of "control" information (Flags, POS, CB\_Type) are taken in network octet order (see Figure 17-17), most significant bit first, to form a 520-bit pattern representing the coefficients of a polynomial  $M(x)$  of degree 519.
+- 2)  $M(x)$  is multiplied by  $x^{24}$  and divided (modulo 2) by  $G(x)$ , producing a remainder  $R(x)$  of degree 23 or less.
+- 3) The coefficients of  $R(x)$  are considered to be a 24-bit sequence, where  $x^{23}$  is the most significant bit.
+- 4) After inversion, this 24-bit sequence is the CRC-24.
+
+Exactly 17 of these 516-octet superblocks are prefixed with the standard GFP core and type headers and 16 octets of "reserved" (padding). Because the number of 516-octet superblocks per GFP frame is known a priori, it is possible for this mapping scheme to operate in a cut-through (as opposed to store and forward) fashion, thus minimizing the mapping latency.
+
+The payload FCS (a CRC-32) is appended to the end of each GFP frame and is calculated across the payload information field of the GFP frame as per [ITU-T G.704]. The purpose of the payload FCS is to provide visibility of bit errors occurring anywhere in the GFP payload information field and thus augments the coverage provided by the per-superblock CRC-24 (which only provides coverage for the "control" overhead in each superblock). The payload FCS is only for the purposes of gathering statistics.
+
+All octets in the GFP payload area are scrambled using the  $X^{43} + 1$  self-synchronous scrambler, again as per [ITU-T G.704].
+
+## 17.9 Mapping a supra-2.488 Gbit/s CBR signal into OPUflex using BMP
+
+Mapping of a supra-2.488 Gbit/s CBR client signal (with up to  $\pm 100$  ppm bit-rate tolerance) into an OPUflex is performed by a bit-synchronous mapping procedure (BMP). Table 17-14 specifies the clients defined by this Recommendation.
+
+The bit-synchronous mapping process deployed to map constant bit rate client signals into an OPUflex does not generate any justification control signals.
+
+The OPUflex clock for the bit-synchronous mapping is derived from the client signal. During a signal fail condition of the incoming client signal (e.g., in the case of a loss of input signal), this failed incoming signal is replaced by the appropriate replacement signal as defined in Table 17-15. The OPUflex payload signal bit rate shall be within the limits specified in Table 7-3 and the limits for the ODCb clock defined in [ITU-T G.825] and no frame phase discontinuity shall be introduced in this case and when resynchronization on the incoming client signal.
+
+During a signal fail condition of the incoming ODUflex/OPUflex signal (e.g., in the case of an ODUflex-AIS, ODUflex-LCK, ODUflex-OCI condition), the failed client signal is replaced by the appropriate replacement signal as defined in Table 17-15.
+
+The OPUflex overhead for this mapping consists of:
+
+- A payload structure identifier (PSI) including the payload type (PT) as specified in Table 15-9, the client signal fail (CSF) and 254 bytes plus 7 bits reserved for future international standardization (RES);
+- Three justification control (JC) bytes, consisting of two bits for justification control (with fixed 00 value) and six bits reserved for future international standardization;
+- One negative justification opportunity (NJO) byte (carrying a justification byte); and
+- Three bytes reserved for future international standardization (RES).
+
+NOTE – To allow the use of a common asynchronous/bit-synchronous de-mapper circuit for CBR client signals into ODUk (k=1,2,3 and flex), JC, NJO and PJO fields are assumed to be present in the OPUflex frame structure for the mapping of a supra-2.488G CBR client signal (Figure 17-18). This OPUflex frame structure is now compatible with the OPUk frame structure for the mapping of a CBR2G5, CBR10G or CBR40G signal (Figure 17-1). As a CBR signal is mapped into the OPUflex without justification, the NJO field contains a justification byte (stuff), the PJO field contains a data byte (D), and the JC bits are fixed to 00.
+
+The OPUflex payload for this mapping consists of  $4 \times 3808$  bytes (Figure 17-18). Groups of eight successive bits (not necessarily being a byte) of the client signal are mapped into a data (D) byte of the OPUflex payload area under control of the BMP control mechanism. Each data byte in the OPUflex payload area carries 8 client bits.
+
+![Figure 17-18: OPUflex frame structure for the mapping of a supra-2.488 Gbit/s client signal. The diagram shows a grid of columns (15, 16, 17, ..., 3824) and rows (1, 2, 3, 4). Row 1: RES, JC, D, D, ..., 3805D, D. Row 2: RES, JC, D, D, ..., 3805D, D. Row 3: RES, JC, D, D, ..., 3805D, D. Row 4: PSI, NJO (stuff), PJO (D), D, ..., 3805D, D. The first four columns are labeled 'OPUflex OH' and the rest are 'OPUflex payload (4 x 3808 bytes)'. Below the grid, a callout shows the PSI byte structure: PT (bit 0), CSF (bit 1), and RES (bits 2-255). Another callout shows the JC byte structure: JC (bits 0-1), Reserved (bits 2-7), and JC (bits 8-9, fixed 00).](a66383962afcd0f0458f0d45c101fabf_img.jpg)
+
+Figure 17-18: OPUflex frame structure for the mapping of a supra-2.488 Gbit/s client signal. The diagram shows a grid of columns (15, 16, 17, ..., 3824) and rows (1, 2, 3, 4). Row 1: RES, JC, D, D, ..., 3805D, D. Row 2: RES, JC, D, D, ..., 3805D, D. Row 3: RES, JC, D, D, ..., 3805D, D. Row 4: PSI, NJO (stuff), PJO (D), D, ..., 3805D, D. The first four columns are labeled 'OPUflex OH' and the rest are 'OPUflex payload (4 x 3808 bytes)'. Below the grid, a callout shows the PSI byte structure: PT (bit 0), CSF (bit 1), and RES (bits 2-255). Another callout shows the JC byte structure: JC (bits 0-1), Reserved (bits 2-7), and JC (bits 8-9, fixed 00).
+
+Figure 17-18 – OPUflex frame structure for the mapping of a supra-2.488 Gbit/s client signal
+
+Table 17-14 – supra-2.488G CBR clients
+
+| Client signal | Nominal bit rate (kbit/s) | Bit-rate tolerance (ppm) |
+|---------------|---------------------------|--------------------------|
+| FC-400        | 4 250 000                 | ±100                     |
+| FC-800        | 8 500 000                 | ±100                     |
+| FC-1600       | 14 025 000                | ±100                     |
+| FC-3200       | 28 050 000                | ±100                     |
+| IB SDR        | 2 500 000                 | ±100                     |
+| IB DDR        | 5 000 000                 | ±100                     |
+| IB QDR        | 10 000 000                | ±100                     |
+| 3G SDI        | 2 970 000                 | ± 10                     |
+| 3G SDI        | 2 970 000/1.001           | ±10                      |
+
+**Table 17-15 – Replacement signal for supra-2.488 Gbit/s clients**
+
+| Client signal  | Replacement signal | Bit-rate tolerance (ppm) |
+|----------------|--------------------|--------------------------|
+| <b>FC-400</b>  | NOS                | ±100                     |
+| <b>FC-800</b>  | NOS                | ±100                     |
+| <b>FC-1600</b> | NOS                | ±100                     |
+| <b>FC-3200</b> | NOS                | ±100                     |
+| <b>IB SDR</b>  | For further study  | ±100                     |
+| <b>IB DDR</b>  | For further study  | ±100                     |
+| <b>IB QDR</b>  | For further study  | ±100                     |
+| <b>3G SDI</b>  | Generic-AIS        | For further study        |
+
+### 17.9.1 FC-400 and FC-800
+
+During a signal fail condition of the incoming FC-400/FC-800 signal (e.g., in the case of a loss of input signal), this failed incoming FC-400/FC-800 signal is replaced by an NOS primitive sequence as specified in [b-INCITS 470].
+
+NOTE – The NOS primitive sequence ordered set is defined as /K28.5/D21.2/D31.5/D5.2/.
+
+During a signal fail condition of the incoming ODUflex signal (e.g., in the case of an ODUflex-AIS, ODUflex-LCK, ODUflex-OCI condition), NOS primitive sequence ordered sets as specified in [b-INCITS 470] are generated as a replacement signal for the lost FC-400/FC-800 signal.
+
+### 17.9.2 FC-1600
+
+The characteristic information of the mapped FC-1600 client signal consists of a sequence of 64B/66B encoded blocks with a nominal bit-rate of 14 025 000 kbit/s, ±100 ppm.
+
+In case the FC-1600 interface at the mapper has FEC enabled the mapper must recover the FEC code word synchronization, extract the FEC parity bits, perform error correction and transdecode the 64B/65B blocks to 64B/66B blocks as specified in [b-INCITS 470].
+
+In case the FC-1600 interface at the demapper has FEC enabled the demapper must recover 66B block lock from the demapped CBR signal, transcode the 64B/66B blocks to 64/65B blocks, generate and insert the FEC parity bits as specified in [b-INCITS 470].
+
+NOTE – FC-1600 interface ports designed prior to Edition 4.6 may not be able to support termination of the FEC or transdecoding of 64B/65B blocks.
+
+During a signal fail condition of the incoming FC-1600 signal (e.g., in the case of a loss of input signal), this failed incoming FC-1600 signal is replaced by a NOS primitive sequence as specified in [b-INCITS 470].
+
+During signal fail condition of the incoming ODUflex signal (e.g., in the case of an ODUflex-AIS, ODUflex-LCK, ODUflex-OCI condition), NOS primitive sequence ordered sets as specified in [b-INCITS 470] are generated as a replacement signal for the lost FC-1600 signal.
+
+### 17.9.3 FC-3200
+
+The characteristic information of the mapped FC-3200 client signal consists of a sequence of 64B/66B encoded blocks with a nominal bit-rate of 28 050 000 kbit/s, ±100 ppm.
+
+The mapper must recover the FEC code word synchronization, extract the FEC parity bits, perform error correction and transdecode the 256B/257B blocks to 64B/66B blocks as specified in [b-INCITS 488]. Uncorrectable FEC code words shall be replaced with error control blocks at the output of the transdecoder.
+
+The demapper must recover 66B block lock from the demapped CBR signal, transcode the 64B/66B blocks to 256/257B blocks, generate and insert the FEC parity bits as specified in [b-INCITS 488].
+
+During a signal fail condition of the incoming FC-3200 signal (e.g., in the case of a loss of input signal), this failed incoming FC-3200 signal is replaced by a NOS primitive sequence as specified in [b-INCITS 488] at the output of the transdecoder.
+
+During signal fail condition of the incoming ODUflex signal (e.g., in the case of an ODUflex-AIS, ODUflex-LCK, ODUflex-OCI condition), NOS primitive sequence ordered sets as specified in [b-INCITS 488] are generated as a replacement signal for the lost FC-3200 signal at the input of the transcoder.
+
+## 17.10 Mapping of packet client signals into OPUk
+
+A set of packet client signals with an aggregated bandwidth of less or equal than 100 Gbit/s is encapsulated into GFP-F as specified in [ITU-T G.704] and then mapped into an OPUk, OPUflex(GFP) or OPUflex(GFP,n,k) as specified in clause 17.4 and 12.2.5.
+
+A set of packet client signals with an aggregate bandwidth of any rate may be presented (see Note) as a stream of Ethernet MAC frames and interframe gaps and then 64B/66B encoded as specified in [IEEE 802.3] Table 82-5. This 64B/66B encoded packet client signal is then mapped into an OPUflex(IMP) as specified in clause 17.11.
+
+A set of packet client signals with an aggregated bandwidth of more than 100 Gbit/s may be presented (see Note) as an  $n \times 25$  Gbit/s stream of Ethernet MAC frames and interframe gaps and then 64B/66B encoded as specified in [IEEE 802.3] Table 82-5 into a FlexE Client signal [OIF FlexE IA] which is then mapped into an OPUflex(IMP,s) as specified in clause 17.11.
+
+A set of packet client signals with an aggregated bandwidth of less or equal than 100 Gbit/s may be presented (see Note) as a 10, 25, 40, 50, 75 or 100 Gbit/s stream of Ethernet MAC frames and interframe gaps and then 64B/66B encoded as specified in [IEEE 802.3] Table 82-5 into a FlexE Client signal [OIF FlexE IA] which is then mapped into an OPUflex(IMP,s) as specified in clause 17.11.
+
+NOTE – Non Ethernet packet clients are assumed to be encapsulated into Ethernet MAC frames before they are presented. Encapsulation is outside the scope of this Recommendation. Ethernet MAC framed packet clients are presented directly.
+
+## 17.11 Mapping of 64B/66B encoded packet client signals into OPUflex using IMP
+
+64B/66B encoded packet client signal bit rates can have any value. Refer to clause 17.10. FlexE Client signal bit rates are  $s \times 5,156,250,000$  kbit/s  $\pm 100$  ppm, with  $s = 2, 8, n \times 5$  ( $n \geq 1$ ). Refer to [OIF FlexE IA].
+
+The 66B block stream shall be scrambled after rate adaptation and before mapping into the OPUflex. In the reverse operation, following termination of the OPUflex signal, the 66 block stream will be descrambled before being passed to the packet client (e.g., FlexE Client) layer.
+
+A self-synchronizing scrambler with generator polynomial  $1 + x^{39} + x^{58}$  shall be used, that is identical to the scrambler specified in clause 49.2.6 [IEEE 802.3]. 66B block stream scrambling is required to provide security against false 66B block delineation (as the two sync header bits bypass the scrambler), the 66B code words replicating the OTU and ODU frame alignment signal and the 66B code words combined with the OTU scrambler pattern used for the interface replicating the OTU and ODU frame alignment signal.
+
+Mapping of a 64B/66B encoded packet client (e.g., FlexE Client) signal (with up to  $\pm 100$  ppm bit-rate tolerance) into an OPUflex is performed by the idle mapping procedure (IMP).
+
+– The OPUflex(IMP) payload bit rate is  $X$  kbit/s  $\pm 100$  ppm and  $X$  is a configured bit rate that can have any value. The ODUflex(IMP) bit rate is  $239/238 \times X$  kbit/s  $\pm 100$  ppm.
+
+- The OPUflex(IMP,s) payload bit rate is  $s \times 5,156,250.000 \text{ kbit/s} \pm 100 \text{ ppm}$ , with  $s = 2, 8, n \times 5$  ( $n \geq 1$ ). The ODUflex bit rate is  $s \times 239/238 \times 5,156,250.000 \text{ kbit/s} \pm 100 \text{ ppm}$ .
+
+The Idle mapping procedure deploys a clock rate adaptation scheme based on Idle control character (/I/) insert/delete as per clause 82.2.3.6 of [IEEE 802.3] and/or sequence ordered set (/O/) delete as per clause 82.2.3.9 of [IEEE 802.3].
+
+The OPUflex overhead for this mapping consists of a:
+
+- payload structure identifier (PSI) including the payload type (PT) as specified in Table 15-9, the client signal fail (CSF) and 254 bytes plus 7 bits reserved for future international standardization (RES);
+- seven bytes reserved for future international standardization (RES).
+
+The OPUflex payload for this mapping consists of  $4 \times 3808$  bytes (Figure 17-19). Scrambled 66B blocks of the client signal are mapped into 66-bits of the OPUflex payload area under control of the IMP control mechanism. The 66B blocks are aligned so that the first bit of the sync header appears in one of the bit positions 1, 3, 5, or 7 of a byte in the OPUflex payload.
+
+![Figure 17-19 – OPUflex frame structure for the mapping of a FlexE Client signal. The diagram shows a grid of rows and columns. Rows 1-3 are labeled RES, and Row 4 is labeled PSI. Columns 15, 16, 17, and 3824 are shown. The main area is labeled '64b/66b encoded packet client (e.g., FlexE Client) 2-bit aligned stream of 66 b blocks'. Below the grid, a callout shows the PSI structure with PT, CSF, and RES fields. Another callout shows a '66b code word' with a 2-bit sync header and 64 bits of data. The bottom of the diagram is labeled 'OPU flex payload (4 x 30464 bits)' and 'OPU flex OH'.](57134800ac3a97b6212b27b93aa196ac_img.jpg)
+
+The diagram illustrates the OPUflex frame structure. It features a grid with columns 15, 16, 17, and 3824, and rows 1 through 4. Rows 1, 2, and 3 are labeled 'RES' (Reserved), while Row 4 is labeled 'PSI' (Payload Structure Identifier). The main payload area is described as '64b/66b encoded packet client (e.g., FlexE Client) 2-bit aligned stream of 66 b blocks'. A callout for the PSI shows its internal structure: PT (Payload Type) at bit 0, CSF (Client Signal Fail) at bits 1 and 2, and RES (Reserved) for bits 3 through 255. Another callout shows a '66b code word' structure, consisting of a 2-bit sync header followed by 64 bits of data. The total payload is labeled 'OPU flex payload (4 x 30464 bits)', and the overhead area is labeled 'OPU flex OH'. The diagram is identified by the code 'G.709-Y.1331(20)\_F17-19'.
+
+Figure 17-19 – OPUflex frame structure for the mapping of a FlexE Client signal. The diagram shows a grid of rows and columns. Rows 1-3 are labeled RES, and Row 4 is labeled PSI. Columns 15, 16, 17, and 3824 are shown. The main area is labeled '64b/66b encoded packet client (e.g., FlexE Client) 2-bit aligned stream of 66 b blocks'. Below the grid, a callout shows the PSI structure with PT, CSF, and RES fields. Another callout shows a '66b code word' with a 2-bit sync header and 64 bits of data. The bottom of the diagram is labeled 'OPU flex payload (4 x 30464 bits)' and 'OPU flex OH'.
+
+**Figure 17-19 – OPUflex frame structure for the mapping of a FlexE Client signal**
+
+During a signal fail condition of the incoming 64B/66B encoded packet client (e.g., FlexE Client) signal (e.g., in the case of a loss of input signal), this failed incoming client signal is replaced by a stream of 66B blocks, with each block carrying one local fault sequence ordered set (as specified in [FlexE IA], [IEEE 802.3]). This replacement signal is then mapped into the OPUflex.
+
+During a signal fail condition of the incoming ODUflex/OPUflex signal (e.g., in the case of an ODUflex-AIS, ODUflex-LCK, ODUflex-OCI condition), a stream of 66B blocks, with each block carrying one local fault sequence ordered sets (as specified in [FlexE IA], [IEEE 802.3]) is generated as a replacement signal for the lost client signal.
+
+NOTE 1 – A 64B/66B encoded packet client (e.g., FlexE Client) signal local fault sequence ordered set is a 66B control block (sync header = 10) with a block type of 0x4B, an "O" code of 0x00, a value of 0x01 to indicate a "local fault" in lane 3, and all of the other octets (before scrambling) equal to 0x00.
+
+## 17.12 Mapping of FlexE aware signals into OPUflex
+
+In the FlexE aware service  $p$  ( $1 \leq p \leq m \leq 252$ ) 100G FlexE Instances – out of an  $m \times 100G$  FlexE Instance Group signal – are crunched, padded and interleaved as per Figure 17-20. This results in a FlexE partial rate (sub)group signal with a length of  $1024 \times n$  blocks, with  $n = n_1 + n_2 + \dots + n_p$  (FlexEp-n):
+
+- $i = 1 \dots p$  represent the FlexE Instances in ascending FlexE Instance number order.
+- $n_i$  ( $i = 1..p$ ) represents the number of FlexE 5G-equivalent calendar slots that are to be transferred. Supported calendar slots are of 5G or 25G type. A 25G calendar slots is equivalent to five consecutive 5G calendar slots, so if  $N_i$  25G calendar slots must be transferred,  $n_i = 5 \times N_i$ .
+- The value of  $n_i$  for each of the  $p$  FlexE Instances is negotiated between the FlexE partial rate (sub)group mapping port and the FlexE Shim in the customer equipment.  $q$  ( $0 \leq q \leq p$ ) out of the  $p$  FlexE Instances may have their  $n_i$  set to 20 while the other  $p-q$  FlexE Instances may have their  $n_i$  set to values of 0, 5, 10 and 15.
+- Bits of the Ethernet error control blocks in  $20-n_i$  5G-equivalent calendar slots that are marked unavailable are located at the end of the sub-calendar and are dropped by the mapper to reduce the rate and reinserted by the demapper to restore the original rate.
+- The FlexE partial rate (sub)group interleaving is simplified by adding  $n_i-1$  padding blocks between the overhead block and the first sub-calendar block in each of the  $p$  FlexE Instances. The value of each padding block is an Ethernet error control block.
+- The  $p$  OH blocks are interleaved in the order #1, #2 to # $p$ . The  $p$   $n_i-1$  padding blocks are interleaved in the order #1, #2 to # $p$ . The  $p$  sub-calendar blocks (of length  $n_1, n_2$  to  $n_p$ ) are interleaved in the order #1, #2 to # $p$ .
+
+NOTE 1 – An Ethernet error control block is a 66B control block (sync header = 10) with a block type of 0x1E and the other eight 7-bit characters equal to 0x1E.
+
+NOTE 2 – The remaining  $m-p$  100G FlexE Instances – out of an  $m \times 100G$  FlexE Instance group signal – are carried via other ODUflex signals carried in other ODUCn/OTUCn/OTSiA signals.
+
+NOTE 3 – Values of  $p$  and  $n$  (in FlexEp-n) supported and the subset of the  $p \times 20$  5G-equivalent calendar slots that are included in the FlexEp-n mapped into the OPUflex are vendor specific and outside the scope of this Recommendation.
+
+NOTE 4 – Each 100G FlexE Instance in the FlexE Aware service is an equipped 100G FlexE Instance extracted from a 100G, 200G or 400G Ethernet PHY. The first FlexE Instance of a PHY is always equipped. So, there are one or two equipped FlexE Instances per PHY in a FlexE Group over  $k \times 200GBASE-R$  PHYs, and one to four equipped FlexE Instances per PHY in a FlexE Group over  $k \times 400GBASE-R$  PHYs. If the last 100G FlexE Instances of a 200G or 400G Ethernet PHY are unequipped, they do not belong to the FlexE (sub)Group and shall not be carried over the OPUflex payload. Unequipped is indicated with a FlexE Group number set to all-zeros. An unequipped FlexE Instance carries LF in all blocks except in its first OH block (Order Set with 0x5 "O" code used for alignment).
+
+![Figure 17-20 – Full/partial rate FlexE Instance interleaving. The diagram shows multiple FlexE instances (Instance #1, Instance #2, Instance #p) being interleaved into a single FlexE (sub)Group. Each instance has an overhead (OH) and a payload (n_i). The interleaved stream has a total length of 1024*n. A MUX is shown combining the instances. Below the main diagram, two callouts show the internal structure: one for the overhead (OH_1, OH_2, ..., OH_p, n-p) and another for the payload (n_1, n_2, ..., n_p).](3349dc82c6333221b0610be6ee7250b6_img.jpg)
+
+The diagram illustrates the interleaving of multiple FlexE instances into a single (sub)group. At the top, there are rows for 'From 100G FlexE Instance #1 (n<sub>1</sub> ≤ 20)', 'From 100G FlexE Instance #2 (n<sub>2</sub> ≤ 20)', and 'From 100G FlexE Instance #p (n<sub>p</sub> ≤ 20)'. Each row shows an overhead (OH<sub>1</sub>, OH<sub>2</sub>, OH<sub>p</sub>) followed by payload blocks (n<sub>1</sub>, n<sub>2</sub>, n<sub>p</sub>). A 'MUX' arrow points down to the 'FlexE (sub)Group (n = n<sub>1</sub> + n<sub>2</sub> + ... + n<sub>p</sub>)' row. This row shows a combined overhead (OH) and interleaved payload blocks (n). Above the rows are indices: #0, #1, #2, #3, #4, #5, #6, #7, ..., #1021, #1022, #1023. Below the main grid, a double-headed arrow indicates a total length of '1024\*n'. Two dashed boxes at the bottom show detailed views: the left one shows the overhead sequence (OH<sub>1</sub>, OH<sub>2</sub>, ..., OH<sub>p</sub>, n-p) and the right one shows the payload sequence (n<sub>1</sub>, n<sub>2</sub>, ..., n<sub>p</sub>).
+
+Figure 17-20 – Full/partial rate FlexE Instance interleaving. The diagram shows multiple FlexE instances (Instance #1, Instance #2, Instance #p) being interleaved into a single FlexE (sub)Group. Each instance has an overhead (OH) and a payload (n\_i). The interleaved stream has a total length of 1024\*n. A MUX is shown combining the instances. Below the main diagram, two callouts show the internal structure: one for the overhead (OH\_1, OH\_2, ..., OH\_p, n-p) and another for the payload (n\_1, n\_2, ..., n\_p).
+
+G.709-Y.1331(16)-Amd.3(19)\_F17-20
+
+**Figure 17-20 – Full/partial rate FlexE Instance interleaving**
+
+The 66B block stream of the FlexE partial rate (sub)group signal shall be scrambled after rate adaptation and before mapping into the OPUflex. In the reverse operation, following termination of the OPUflex signal, the 66B block stream will be descrambled before being passed to the FlexE deinterleaving, depadding and decrunching process.
+
+A self-synchronizing scrambler with generator polynomial  $1+x^{39}+x^{58}$  shall be used, that is identical to the scrambler specified in clause 49.2.6 [IEEE 802.3]. 66B block stream scrambling is required to provide security against false 66B block delineation (as the two sync header bits bypass the scrambler), the 66B codewords replicating the OTU and ODU frame alignment signal and the 66B codewords combined with the OTU scrambler pattern used for the interface replicating the OTU and ODU frame alignment signal.
+
+The FlexE partial rate (sub)group signal (with up to  $\pm 100$  ppm bit-rate tolerance) is mapped into the OPUflex as per the encoding and stuffing distribution described below. The OPUflex payload bit rate is  $100\text{GE\_bit\_rate} \times 240/239 \times n/20$  kbit/s  $\pm 100$  ppm, with  $n = n_1 + n_2 + \dots + n_p$ . The ODUflex bit rate is  $100\text{GE\_bit\_rate} \times 240/238 \times n/20$  kbit/s  $\pm 100$  ppm.
+
+On the transmit side, the stuffing is inserted as 16-byte blocks and systematically controlled using a 15 bit sigma-delta as:
+
+$$100\text{GE\_rate} \times (16\text{k}-1)/16\text{k} \times n \times 1024/(1+20 \times 1023) = 100\text{GE\_rate} \times n/20 \times 240/238 \times 238/239 \times (4 \times 238 - 3 - s)/(4 \times 238) \rightarrow s = 3373/23384 \text{ (Numerator=3373, Denominator=23384)}$$
+
+This encoding uses a bitsynchronous generic mapping procedure (BGMP) for the distribution and encoding of the stuffing. The GMP is operated in a special mode, where the  $C_m$  value does not come from a synchronizer but is generated deterministically, and  $\sum C_{nD}$  is unused ( $C_n = C_m$ ).
+
+As shown in the Figure 17-22, a value of  $n = m = 128$  (16-Byte) is chosen. Given the deterministic generation of the stuffing, only two  $C_{128}(t)$  values are used for this mapping ( $C_{128} = 948$  or  $949$ ). Generating  $C_{128} = 949$  (vs.  $C_{128} = 948$ ) is deterministic at the source ( $s = 3373/23384$ , 15-bit sigma-delta).
+
+$C_m(t)$  is deterministically generated using a sigma-delta  $C_m=948/C_m=949$  justification distribution with  $s = 3373/23384$ :
+
+The distribution of the deterministic justification ( $C_m(t)=948$ , instead of  $C_m(t)=949$ ) follows the sigma-delta equation below:
+
+$$- \quad C_m(t) = 948 \quad \text{if } (j \times 3373) \bmod 23384 < 3373 \quad (17-13)$$
+
+$$- \quad C_m(t) = 949 \quad \text{if } (j \times 3373) \bmod 23384 \geq 3373 \quad (17-14)$$
+
+The index 'j' in equations (17-13) and (17-14) enumerates frames in the 23384 frame sequence. It counts from 1 to 23384.
+
+![Figure 17-21: Sigma-delta accumulator for deterministic justification generation. The diagram shows a feedback loop with two adders and a comparator. The first adder adds the current Accumulator value to the Denominator. The output of this adder is compared with the Denominator input. If the sum is greater than or equal to the Denominator, the Accumulator is updated to (Accumulator + Numerator - Denominator). Otherwise, it is updated to (Accumulator + Numerator). The second adder adds the current Accumulator value to the Numerator. The output of this adder is compared with the Denominator. If the result is less than the Denominator, Cm(t) is set to 949. Otherwise, Cm(t) is set to 948. The loop repeats for each frame j from 1 to 23384. Numerator = 3373, Denominator = 23384.](2d548db0b26b7bf33244320322d5ee2c_img.jpg)
+
+```
+
+if (Accumulator + Numerator >= Denominator) then
+    Accumulator <= Accumulator + Numerator - Denominator;
+else
+    Accumulator <= Accumulator + Numerator;
+end if;
+end repeat;
+Numerator = 3373, Denominator = 23384
+
+if "0" then Cm(t) <= 949
+Elsif "1" then Cm(t) <= 948
+  
+```
+
+G.709-Y.1331(16)\_F17-21
+
+Figure 17-21: Sigma-delta accumulator for deterministic justification generation. The diagram shows a feedback loop with two adders and a comparator. The first adder adds the current Accumulator value to the Denominator. The output of this adder is compared with the Denominator input. If the sum is greater than or equal to the Denominator, the Accumulator is updated to (Accumulator + Numerator - Denominator). Otherwise, it is updated to (Accumulator + Numerator). The second adder adds the current Accumulator value to the Numerator. The output of this adder is compared with the Denominator. If the result is less than the Denominator, Cm(t) is set to 949. Otherwise, Cm(t) is set to 948. The loop repeats for each frame j from 1 to 23384. Numerator = 3373, Denominator = 23384.
+
+**Figure 17-21 – Sigma-delta accumulator for deterministic justification generation**
+
+The OPUflex overhead for this mapping consists of a:
+
+- payload structure identifier (PSI) including the payload type (PT) as specified in Table 15-9, the client signal fail (CSF) and 253-p bytes plus 7 bits reserved for future international standardization (RES);
+- PSI[3] carries the value of p
+- PSI[4] to PSI[3+p] carries the values of  $n_1$  to  $n_p$
+- three justification control (JC1, JC2, JC3) bytes carrying the value of GMP overhead  $C_m$ ;
+- four bytes reserved for future international standardization (RES).
+
+The JC1, JC2 and JC3 bytes consist of a 14-bit  $C_m$  field (bits C1, C2, ..., C14), a 1-bit increment indicator (II) field, a 1-bit decrement indicator (DI) field and an 8-bit CRC-8 field which contains an error check code over the JC1, JC2 and JC3 fields.
+
+The OPUflex payload for this mapping consists of  $4 \times 3808$  bytes (Figure 17-22). Blocks of 16 bytes in the OPUflex payload area are numbered from 1 to 952. The OPUflex payload byte numbering for GMP 16-byte (128-bit) blocks is illustrated in Figure 17-22. In row 1 of the OPUflex frame the first 16-byte block will be labelled 1, the next 16-byte block will be labelled 2, etc.
+
+Groups of one hundred twenty-eighth successive bits of the client signal are mapped into a 16-byte block of the OPUflex payload area under control of the BGMP data/stuff control mechanism. For the case of  $C_{128} = 948$ , 16 byte blocks #1, #239, #477 and #715 are carrying stuff bits and the other 16-byte blocks are carrying client bits. For the case of  $C_{128} = 949$ , 16 byte blocks #1, #318 and #635 are carrying stuff bits and the other 16-byte blocks are carrying client bits. The stuff bits are set to zero.
+
+Scrambled 64B/66B blocks of the client signal are mapped into 66-bits of the OPUflex payload area skipping the 16-byte Stuff blocks under control of the BGMP control mechanism. The 66B blocks are aligned so that the first bit of the sync header appears in one of the bit positions 1, 3, 5, or 7 of a byte in the OPUflex payload.
+
+![](9dc88fb2c48bc64047fc3e79814f1d47_img.jpg)
+
+$C_m = C_{128} = 948, \sum C_{nd} \text{ unused (e.g., } n = m = 128)$
+
+|     |     | 1           | 2   | ...          | 238 |
+|-----|-----|-------------|-----|--------------|-----|
+| RES | JC1 | 1 (stuff)   | ... | 2            | 238 |
+| RES | JC2 | 239 (stuff) | 240 | Payload area | 476 |
+| RES | JC3 | 477 (stuff) | 478 |              | 714 |
+| PSI | RES | 715 (stuff) | 716 | ...          | 952 |
+
+16B      238\*16B
+
+$C_m = C_{128} = 949, \sum C_{nd} \text{ unused (e.g., } n = m = 128)$
+
+|     |     | 1         | ... | 80          | ... | 159 | ... | 238 |
+|-----|-----|-----------|-----|-------------|-----|-----|-----|-----|
+| RES | JC1 | 1 (stuff) | ... | 318 (stuff) | ... | 238 |     |     |
+| RES | JC2 | 239       |     |             |     | 476 |     |     |
+| RES | JC3 | 477       |     |             |     | 714 |     |     |
+| PSI | RES | 715       | ... |             |     | 952 |     |     |
+
+16B      237\*16B
+
+PSI
+
+|     |                |
+|-----|----------------|
+| 0   | PT             |
+| 1   | RES            |
+| 2   | RES            |
+| 3   | p              |
+| 4   | n <sub>1</sub> |
+| 5   | n <sub>2</sub> |
+| ⋮   | ⋮              |
+| 3+p | n <sub>p</sub> |
+| 255 | RES            |
+
+|     | 1    | 2   | 3   | 4   | 5   | 6   | 7  | 8  |
+|-----|------|-----|-----|-----|-----|-----|----|----|
+| JC1 | C1   | C2  | C3  | C4  | C5  | C6  | C7 | C8 |
+| JC2 | C9   | C10 | C11 | C12 | C13 | C14 | II | DI |
+| JC3 | CRC8 |     |     |     |     |     |    |    |
+
+66b code word
+
+|   |         |
+|---|---------|
+| 2 | 64 bits |
+|---|---------|
+
+G.709-Y.1331(16)\_F17-22
+
+**Figure 17-22 – Mapping of the combined FlexE stream into ODUflex via deterministic stuffing and using GMP encoding**
+
+During a signal fail condition of an incoming equipped 100G FlexE Instance (e.g., in the case of a loss of 100G/200G/400G input PHY signal carrying this 100G FlexE Instance or FlexE local fault condition), this failed incoming 100G FlexE Instance and the p-1 other 100G FlexE Instances are not mapped into the payload of the OPUflex. Instead the OPUflex payload is filled with the stuff blocks, 66B blocks that carry a local fault sequence ordered set and the OPU CSF bit is set to "1". The OPUflex clock is derived from a local clock. The OPUflex payload signal bit rate shall be within the limits specified in Table 7-3 and the limits for the ODCb defined in [ITU-T G.8251] and no frame phase discontinuity shall be introduced in this case and when resynchronization on the incoming client signal.
+
+During a signal fail condition of the incoming ODUflex/OPUflex signal (e.g., in the case of an ODUflex-AIS, ODUflex-LCK, ODUflex-OCI condition) or a CSF condition is present in the OPUflex overhead, a stream of 66B blocks, with each block carrying one local fault sequence ordered set is generated as a replacement signal for each of the p lost FlexE signals.
+
+NOTE 4 – A FlexE Instance local fault sequence ordered set is a 66B control block (sync header = 10) with a block type of 0x4B, an "O" code of 0x00, a value of 0x01 to indicate a "local fault" in lane 3, and all of the other octets (before scrambling) equal to 0x00.
+
+### 17.13 Mapping a 64B/66B PCS coded signal into OPUflex using BMP and 2-bit alignment of 66B code words
+
+Mapping of a 64B/66B PCS coded (xGBASE-R) client signal (with up to  $\pm 100$  ppm bit-rate tolerance) into an OPUflex is performed by a bit-synchronous mapping procedure (BMP). Table 17-16 specifies the clients defined by this Recommendation.
+
+The bit-synchronous mapping process deployed to map constant bit rate client signals into an OPUflex does not generate any justification control signals.
+
+The 66B block stream of the xGBASE-R client signal shall be scrambled before mapping into the OPUflex. In the reverse operation, following termination of the OPUflex signal, the 66 block stream will be descrambled after demapping from the OPUflex.
+
+A self-synchronizing scrambler with generator polynomial  $1 + x^{39} + x^{58}$  shall be used, that is identical to the scrambler specified in clause 49.2.6 of [IEEE 802.3]. 66B block stream scrambling is required to provide security against false 66B block delineation (as the two sync header bits bypass the scrambler), the 66B codewords replicating the OTU and ODU frame alignment signal and the 66B codewords combined with the OTU scrambler pattern used for the interface replicating the OTU and ODU frame alignment signal.
+
+The OPUflex clock for the bit-synchronous mapping is derived from the client signal. During a signal fail condition of the incoming client signal (e.g., in the case of a loss of input signal), this failed incoming signal is replaced by the appropriate replacement signal as defined in Table 17-17. The OPUflex payload signal bit rate shall be within the limits specified in Table 7-3 and the limits defined in [ITU-T G.8251] and no frame phase discontinuity shall be introduced in this case and when resynchronization on the incoming client signal.
+
+During a signal fail condition of the incoming ODUflex/OPUflex signal (e.g., in the case of an ODUflex-AIS, ODUflex-LCK, ODUflex-OCI condition), the failed client signal is replaced by the appropriate replacement signal as defined in Table 17-17.
+
+The OPUflex overhead for this mapping consists of:
+
+- a payload structure identifier (PSI) including the payload type (PT) as specified in Table 15-9, the client signal fail (CSF) and 254 bytes plus 7 bits reserved for future international standardization (RES);
+- seven bytes reserved for future international standardization (RES).
+
+The OPUflex payload area for this mapping consists of  $4 \times 3808$  bytes (see Figure 17-23). Scrambled 64B/66B blocks of the client signal are mapped into 66-bits of the OPUflex payload area. The 66B blocks are aligned so that the first bit of the sync header appears in one of the bit positions 1, 3, 5, or 7 of a byte in the OPUflex payload.
+
+![Figure 17-23: OPUflex frame structure for the mapping of a 64B/66B PCS client signal with 2-bit alignment. The diagram shows a large frame with a 'Payload area' of 3808 x 8 bits. The frame is divided into sections: RES RES, RES RES, RES RES, and PSI RES. Below the frame, a 'PSI' section is shown with rows 0 to 255. Row 0 contains 'PT', row 1 contains 'RES', row 2 contains 'CSF' and 'RES'. Rows 3 to 255 contain 'RES'. To the right of the PSI section, a '66b code word' is shown, consisting of a 2-bit alignment marker and a 64-bit data payload.](0ab0282f295c2fcf97b7197e7aeb1381_img.jpg)
+
+G.709-Y.1331(16)-Amd.1(16)\_F17-23
+
+Figure 17-23: OPUflex frame structure for the mapping of a 64B/66B PCS client signal with 2-bit alignment. The diagram shows a large frame with a 'Payload area' of 3808 x 8 bits. The frame is divided into sections: RES RES, RES RES, RES RES, and PSI RES. Below the frame, a 'PSI' section is shown with rows 0 to 255. Row 0 contains 'PT', row 1 contains 'RES', row 2 contains 'CSF' and 'RES'. Rows 3 to 255 contain 'RES'. To the right of the PSI section, a '66b code word' is shown, consisting of a 2-bit alignment marker and a 64-bit data payload.
+
+**Figure 17-23 – OPUflex frame structure for the mapping of a 64B/66B PCS client signal with 2-bit alignment**
+
+**Table 17-16 – Supra-2.488G CBR clients**
+
+| Client signal            | Nominal bit rate (kbit/s) | Bit-rate tolerance (ppm) |
+|--------------------------|---------------------------|--------------------------|
+| <b>25GBASE-R</b>         | 25 781 250                | ±100                     |
+| <b>50GBASE-R</b>         | 51 562 500                | ±100                     |
+| <b>200GBASE-R (Note)</b> | 206 250 000               | ±100                     |
+| <b>400GBASE-R (Note)</b> | 412 500 000               | ±100                     |
+
+NOTE – These signals represent a rate adapted 64B/66B encoded signal, which includes RC blocks.
+
+**Table 17-17 – Replacement signal for supra-2.488 Gbit/s clients**
+
+| Client signal     | Replacement signal | Bit-rate tolerance (ppm) |
+|-------------------|--------------------|--------------------------|
+| <b>25GBASE-R</b>  | LF (Note 1)        | ±100                     |
+| <b>50GBASE-R</b>  | LF (Note 3)        | ±100                     |
+| <b>200GBASE-R</b> | LF (Note 2)        | ±100                     |
+| <b>400GBASE-R</b> | LF (Note 2)        | ±100                     |
+
+NOTE 1 – The replacement signal for a 25GBASE-R signal is a continuous stream of 66B encoded and scrambled LF sequence ordered sets encoded according to Figure 49-7 of [IEEE 802.3] using control block type 0x55 (two ordered sets per 66B block) and scrambled according to clause 49.2.6 of [IEEE 802.3].
+
+NOTE 2 – The replacement signal for a 200GBASE-R and 400GBASE-R signal is a continuous stream of LF sequence ordered sets encoded according to Figure 82-5 of [IEEE 802.3] using control block type 0x4B. RC block insertion will be performed on the stream in the mapping direction, while 257B transcoding plus AM insertion will be performed on the stream in the demapping direction after which these signals are scrambled.
+
+NOTE 3 – The replacement signal for a 50GBASE-R signal is a continuous stream of 66B encoded and scrambled LF sequence ordered sets encoded according to Figure 82-5 of [IEEE 802.3] using control block type 0x4B with 4 PCS lane alignment markers inserted after each 20479 x 4 sixty-six-bit blocks and scrambled according to clause 49.2.6 of [IEEE 802.3].
+
+### 17.13.1 25GBASE-R
+
+The mapped format for the signal is the 25GBASE-R PCS sublayer as defined in clause 107 of [IEEE 802.3], with a bit-stream at a signalling rate of 25.78125 Gb/s consisting of 64B/66B encoded blocks.
+
+25GBASE-R PHYs may use one of three different operational modes: No FEC, BASE-R FEC, or RS FEC. Only the RS FEC operational mode is applicable to optical PHYs, while any of the three modes may be used for backplane and copper cable PHYs, with the operational mode selected between the endpoints of a PHY link via auto-negotiation.
+
+The No FEC mode of operation sends bits at the physical layer using the same format as the PCS: a continuous stream of 64B/66B blocks at 25.78125 Gb/s  $\pm 100$  ppm.
+
+In the BASE-R FEC mode of operation, the signal is encoded according to clause 74 of [IEEE 802.3], using a shortened cyclical code (2112,2080). This code removes the redundant sync header bit from each of thirty-two 66B blocks and adds 32 bits of parity to produce the 2112-bit FEC codeword. The FEC is framed by the mapper using a "search and test" algorithm as described in clause 73 of [IEEE 802.3]. Errors are corrected, the FEC parity is removed, and the second sync header bit is restored to produce the stream of 66B blocks to map into OPUflex. The demapper removes the redundant sync header bit from each 66B block and adds the 32 bits of parity to each group of thirty-two, now 65B blocks. Since this process adds and removes the same number of bits in the process of encoding and decoding the FEC, this mapping is timing transparent.
+
+In the RS FEC mode of operation, the signal is encoded according to clause 108 of [IEEE 802.3], using a Reed-Solomon (528,514) error correcting code based on 10-bit symbols. Each group of four 66B blocks from the PCS is transcoded into a 257B block. Twenty 257B blocks (5140 bits) are combined with 140 bits of FEC parity (14 FEC symbols) to produce a 5280-bit FEC codeword. To frame the bit-stream, a 257-bit codeword marker (CWM) is inserted as the first 257 bits of every 1024th FEC codeword, with sufficient idles being deleted from the PCS to make room for the CWM at the same bit-rate as the PCS. The mapper will reverse this process, finding the CWMs in the bit-stream, decoding the FEC and correcting errors, removing the CWMs, trans-decoding 257B to 64B/66B, and inserting idles to maintain the bit-rate as described in the Rx direction data flow of clause 108 of [IEEE 802.3]. The demapper will remove idles to make room for the CWM (maintaining the bit-rate), transcode to 257B, and adding the FEC parity to each group of twenty 257B blocks as described in the Tx direction data flow of clause 108 of [IEEE 802.3]. This process preserves the timing of the client signal, and this mapping is timing transparent.
+
+### 17.13.2 200GBASE-R and 400GBASE-R
+
+The characteristic information of the adapted and mapped 200GBASE-R or 400GBASE-R client signal consists of a scrambled sequence of 64B/66B encoded blocks with a nominal bit-rate of X kbit/s  $\pm 100$  ppm.
+
+The mapper shall first recover the 200GBASE-R or 400GBASE-R client stream, which is referred to as the OTN reference signal, that is a sequence of 64B/66B encoded blocks as per clause 119.2.5.7 of [IEEE 802.3], with a bit rate of  $(528/544 \times 20479/20480 \times Y \text{ kbit/s}) \pm 100$  ppm.
+
+NOTE 1 – Y kbit/s is the nominal bit-rate of the aggregate 200GBASE-R or 400GBASE-R PCS signal consisting of 8 or 16 PCS lanes with 256B/257B encoding and FEC at the PMA service interface.
+
+**Table 17-18 – X, Y and Z parameter values**
+
+| Parameter | 200GBASE-R  | 400G BASE-R |
+|-----------|-------------|-------------|
+| X         | 206 250 000 | 412 500 000 |
+| Y         | 212 500 000 | 425 000 000 |
+| Z         | 16          | 32          |
+
+The client stream for the 200GBASE-R or 400G BASE-R OTN reference signal (64B/66B encoded, un-scrambled and without alignment markers) is recovered using the process described in Annex J for parallel 256B/257B interfaces. The lane(s) of the physical interface are bit-disinterleaved, if necessary, into eight or sixteen streams of 26 562 500 kbit/s. Lane alignment marker lock is acquired on each PCS lane, allowing lane deskew and reorder, as well as de-interleave for FEC code word synchronization and error correction. The mapper shall extract the FEC parity bits and alignment markers, perform descrambling and transdecode the 256B/257B blocks to 64B/66B blocks. Uncorrectable FEC code words shall be replaced with error control blocks at the output of the transdecoder.
+
+Then, the client stream for the 200GBASE-R or 400GBASE-R OTN reference signal (or its replacement stream upon signal failure) is rate compensated by inserting Z rate compensation (RC) blocks every (Z × 20479) client blocks (Figure 17-24). The resulting nominal bit-rate of the compensated 64B/66B client stream is  $[528/544 \times Y \text{ kbit/s}] = X \text{ kbit/s} \pm 100 \text{ ppm}$ . The 64B/66B client stream shall be scrambled after rate compensation, and before mapping into the OPUflex.
+
+In the reverse operation, following termination of the OPUflex signal, the demapper must recover 66B block lock from the demapped CBR signal, descramble the 64B/66B client stream, and remove the rate compensation blocks to retrieve the 200GBASE-R or 400GBASE-R client stream at the OTN reference signal as specified in clause 119.2.4.1 of [IEEE 802.3].
+
+![Diagram of adapted xGBASE-R client signal for OPUflex mapping. It shows the flow from an OTN reference signal (unscrambled 64B/66B encoded stream) through rate compensation block insertion, scrambling, and then through the OPUflex mapping process. The diagram includes labels for 'Rate compensation blocks insertion', 'Scramble', 'Z RCs', 'Z × 20K 66b blocks', and 'Self-synchronizing scrambler: G(x) = 1 + x^39 + X^58'. The reverse process is also shown: 'Rate compensation blocks removal', 'Descramble', and 'OTN reference signal'.](7818b1bd115c04ee738bcf90f51d945b_img.jpg)
+
+The diagram illustrates the adaptation of an xGBASE-R client signal for OPUflex mapping. At the top, an 'OTN reference signal' is shown as a sequence of 64B/66B blocks. This signal enters a processing block. On the transmit side (left), 'Rate compensation blocks insertion' occurs, followed by 'Scramble'. The scrambled signal is then mapped into the OPUflex. On the receive side (right), the signal is 'Descramble' and 'Rate compensation blocks removal' occurs to recover the original OTN reference signal. The diagram specifies the insertion of Z RC blocks every Z × 20K 66b blocks. The scrambling process uses a self-synchronizing scrambler with the polynomial  $G(x) = 1 + x^{39} + x^{58}$ , as defined in Clause 49.2.6 [802.3], with a note that the 2-bit sync header is not scrambled. The rate compensation parameters are given as  $Z = 16(200 \text{ GbE}); Z = 32 (400 \text{ GbE})$ .
+
+Diagram of adapted xGBASE-R client signal for OPUflex mapping. It shows the flow from an OTN reference signal (unscrambled 64B/66B encoded stream) through rate compensation block insertion, scrambling, and then through the OPUflex mapping process. The diagram includes labels for 'Rate compensation blocks insertion', 'Scramble', 'Z RCs', 'Z × 20K 66b blocks', and 'Self-synchronizing scrambler: G(x) = 1 + x^39 + X^58'. The reverse process is also shown: 'Rate compensation blocks removal', 'Descramble', and 'OTN reference signal'.
+
+**Figure 17-24 – Adapted xGBASE-R (x = 200, 400) client signal for OPUflex mapping**
+
+Then, 64B/66B blocks to 256/257B blocks transcoding and scrambling can be performed, and as described in Annex J, alignment markers and FEC parity bits can be inserted prior to the 200GBASE-R or 400GBASE-R PCS lane distribution, and interleaving, if necessary, into physical lanes at the PMA interface.
+
+The rate compensation blocks (RC) have the form of a specially defined 66-bit block with a control block sync header. The Z/2 first RC blocks carry an RC0 value, and the last Z/2 RC blocks carry an RC1 value as shown in Figure 17-25.
+
+NOTE 2 – The value of the RC blocks (RC0 or RC1) has been chosen so that it does not match any defined control block. The 8b located at the same position as the block type field (bits 2 to 9 in Figure 17-25) carry the unused value 0x00, still maintaining the 4-bit hamming distance with the defined and used block types. At the sink, the RC pattern can be search on a subset of the RC0 and RC1 bits and blocks, using a simple alignment process.
+
+![Figure 17-25 – Rate compensation blocks format for 200GBASE-R and 400GBASE-R mapping](a6d1b7d9be84a290d618aee634d06d3d_img.jpg)
+
+The diagram shows the structure of 200GBASE-R and 400GBASE-R mapping. For 200GBASE-R, there are 8 × RC0 blocks followed by 8 × RC1 blocks. For 400GBASE-R, there are 16 × RC0 blocks followed by 16 × RC1 blocks. Bit positions are indicated above the blocks (e.g., 0... 56, 66, 552278, 1055, 11005556, 2111). Below the block diagrams are two tables defining the bit patterns for RC0 and RC1.
+
+|                      |    |      |      |      |       |      |       |      |       |      |       |      |       |      |       |      |    |  |
+|----------------------|----|------|------|------|-------|------|-------|------|-------|------|-------|------|-------|------|-------|------|----|--|
+| <b>Bit position:</b> | 0  | 1 2  | 9 10 |      | 17 18 |      | 25 26 |      | 33 34 |      | 41 42 |      | 49 50 |      | 57 58 |      | 65 |  |
+| <b>RC0</b>           | 10 | 0x00 |      | 0xFF |       | 0xFF |       | 0x00 |       | 0x00 |       | 0x00 |       | 0xFF |       | 0xFF |    |  |
+
+  
+
+|                      |    |      |      |      |       |      |       |      |       |      |       |      |       |      |       |      |    |  |
+|----------------------|----|------|------|------|-------|------|-------|------|-------|------|-------|------|-------|------|-------|------|----|--|
+| <b>Bit position:</b> | 0  | 1 2  | 9 10 |      | 17 18 |      | 25 26 |      | 33 34 |      | 41 42 |      | 49 50 |      | 57 58 |      | 65 |  |
+| <b>RC1</b>           | 10 | 0x00 |      | 0x00 |       | 0x00 |       | 0x00 |       | 0xFF |       | 0xFF |       | 0xFF |       | 0xFF |    |  |
+
+G.709-Y.1331(16)-Amd.2(18)\_F17-25
+
+### Figure 17-25 – Rate compensation blocks format for 200GBASE-R and 400GBASE-R mapping
+
+Figure 17-25 – Rate compensation blocks format for 200GBASE-R and 400GBASE-R mapping
+
+**17.13.3 50GBASE-R**
+
+The mapped format for the signal is the 50GBASE-R PCS sublayer as defined in clause 133 of [IEEE 802.3cd]. The 50GBASE-R signal (64B/66B encoded, nominal aggregate bit-rate of 51 562 500 kbit/s ±100 ppm, with alignment markers) is recovered using the following process: block lock and lane alignment marker lock are acquired on each of the four PCS lanes, with bit streams of 12 890 625 kbit/s, at the 50GBASE-R sublayer reference point, allowing the 66B blocks to be de-skewed and reordered. The four PCS lanes are serialized with their respective AMs occurring in sequence. Figure 17-26 illustrates the order of 66B blocks mapped into the ODUflex.
+
+![Figure 17-26 – Order of 66B blocks mapped into ODUflex for 50GBASE-R](73e9791d33fc9c524278fb216945435f_img.jpg)
+
+The diagram shows a sequence of blocks: AM0, AM1, AM2, AM3, followed by a large section labeled '20479 × 4 66 B blocks', and ending with another sequence of AM0, AM1, AM2, AM3.
+
+G.709-Y.1331(16)-Amd.3(19)\_F17-26
+
+### Figure 17-26 – Order of 66B blocks mapped into ODUflex for 50GBASE-R
+
+Figure 17-26 – Order of 66B blocks mapped into ODUflex for 50GBASE-R
+
+The payload of the ODUflex is at a nominal rate of 51 562 500 kbit/s ± 100ppm, which is a precise ratio of 33/34 from the 53 125 000 kbit/s bit-rate of the single-lane FEC encoded signal. For bit-synchronous mapping into an ODUflex, the ODUflex rate is 7887/8092 times the physical line rate of the 50G Ethernet signal; i.e., 7887/8092 × 53 125 000 kbit/s.
+
+In the mapper, the received Ethernet PCS lane BIP may be compared with the expected Ethernet PCS lane BIP as a non-intrusive monitor.
+
+The de-mapper will pass through the PCS lane BIP from the ingress. In addition, the received Ethernet PCS lane BIP may be compared with the expected Ethernet PCS lane BIP as a non-intrusive monitor.
+
+The de-mapper will recover from the output of the BMP processor 64B/66B block lock per the state diagram in Figure 82-10 [IEEE 802.3]. The 66B blocks are re-distributed round-robin to four PCS lanes and these four PCS lanes presented at the 50GBASE-R egress reference point of the PCS layer.
+
+**Rec. ITU-T G.709/Y.1331 (06/2020)**     115
+
+## 18 Blank clause
+
+*This clause is intentionally left blank.*
+
+## 19 Mapping ODUj signals into the ODTU signal and the ODTU into the OPUk tributary slots
+
+This clause specifies the multiplexing of:
+
+- ODU0 into OPU1, ODU1 into OPU2, ODU1 and ODU2 into OPU3 using client/server specific asynchronous mapping procedures (AMP);
+- other ODUj into OPUk using a client agnostic generic mapping procedure (GMP).
+
+This ODUj into OPUk multiplexing is performed in two steps:
+
+- 1) asynchronous mapping of ODUj into optical data tributary unit (ODTU) using either AMP or GMP;
+- 2) byte-synchronous mapping of ODTU into one or more OPUk tributary slots.
+
+### 19.1 OPUk tributary slot definition
+
+The OPUk is divided into a number of tributary slots (TS) and these tributary slots are interleaved within the OPUk. A tributary slot includes a part of the OPUk OH area and a part of the OPUk payload area. The bytes of the ODUj frame are mapped into the ODTU payload area and the ODTU bytes are mapped into the OPUk tributary slot or slots. The bytes of the ODTU justification overhead are mapped into the OPUk OH area.
+
+There are two types of tributary slots:
+
+- 1) Tributary slot with a bandwidth of approximately 2.5 Gbit/s; an OPUk is divided into  $n$  tributary slots, numbered 1 to  $n$ .
+- 2) Tributary slot with a bandwidth of approximately 1.25 Gbit/s; an OPUk is divided into  $2n$  tributary slots, numbered 1 to  $2n$ .
+
+OPU2 and OPU3 interface ports supporting 1.25 Gbit/s tributary slots must also support the 2.5 Gbit/s tributary slot mode for interworking with interface ports supporting only the 2.5G tributary slot mode (i.e., interface ports compliant with issues of this Recommendation: prior to the definition of 1.25G tributary slots). When operated in 2.5G tributary slot mode, 1.25G tributary slots "i" and "i+n" ( $i = 1$  to  $n$ ,  $n = 4$  (OPU2) and  $n = 16$  (OPU3)) function as one 2.5G tributary slot.
+
+#### 19.1.1 OPU2 tributary slot allocation
+
+Figure 19-1 presents the OPU2 2.5G tributary slot allocation and the OPU2 1.25G tributary slot allocation. An OPU2 is divided into four 2.5G tributary slots numbered 1 to 4, or in eight 1.25G tributary slots numbered 1 to 8.
+
+- An OPU2 2.5G tributary slot occupies 25% of the OPU2 payload area. It is a structure with 952 columns by 16 ( $4 \times 4$ ) rows (see Figures 19-1 and 19-7) plus a tributary slot overhead (TSOH). The four OPU2 TSs are byte interleaved in the OPU2 payload area and the four OPU2 TSOHs are frame interleaved in the OPU2 overhead area.
+- An OPU2 1.25G tributary slot occupies 12.5% of the OPU2 payload area. It is a structure with 476 columns by 32 ( $8 \times 4$ ) rows (see Figures 19-1 and 19-7) plus a tributary slot overhead (TSOH). The eight OPU2 TSs are byte interleaved in the OPU2 payload area and the eight OPU2 TSOHs are frame interleaved in the OPU2 overhead area.
+
+An OPU2 2.5G tributary slot "i" ( $i = 1,2,3,4$ ) is provided by two OPU2 1.25G tributary slots "i" and "i+4" as illustrated in Figure 19-1.
+
+The tributary slot overhead (TSOH) of OPU2 tributary slots is located in column 16 plus column 15, rows 1, 2 and 3 of the OPU2 frame.
+
+The TSOH for a 2.5G tributary slot is available once every 4 frames. A 4-frame multiframe structure is used for this assignment. This multiframe structure is locked to bits 7 and 8 of the MFAS byte as shown in Table 19-1 and Figure 19-1.
+
+The TSOH for a 1.25G tributary slot is available once every 8 frames. An 8-frame multiframe structure is used for this assignment. This multiframe structure is locked to bits 6, 7 and 8 of the MFAS byte as shown in Table 19-1 and Figure 19-1.
+
+| MFAS bits (6)78 | Multi-frame row | Frame row | Column |       |    |                 |    |    |    |    |    |    |    |    |    |    |       |      |      |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
+|-----------------|-----------------|-----------|--------|-------|----|-----------------|----|----|----|----|----|----|----|----|----|----|-------|------|------|--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|
+|                 |                 |           | 1      | ..... | 15 | 16              | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | ..... | 3823 | 3824 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
+| (0)00           | 1               | 1         |        |       |    | TSOH TS1        |    |    |    |    |    |    |    |    |    |    |       |      |      |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
+|                 | 2               | 2         |        |       |    |                 |    |    |    |    |    |    |    |    |    |    |       |      |      |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
+|                 | 3               | 3         |        |       |    |                 |    |    |    |    |    |    |    |    |    |    |       |      |      |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
+|                 | 4               | 4         |        |       |    |                 |    |    |    |    |    |    |    |    |    |    |       |      |      |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
+| (0)01           | 5               | 1         |        |       |    | TSOH TS2        |    |    |    |    |    |    |    |    |    |    |       |      |      |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
+|                 | 6               | 2         |        |       |    |                 |    |    |    |    |    |    |    |    |    |    |       |      |      |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
+|                 | 7               | 3         |        |       |    |                 |    |    |    |    |    |    |    |    |    |    |       |      |      |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
+|                 | 8               | 4         |        |       |    |                 |    |    |    |    |    |    |    |    |    |    |       |      |      |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
+|                 | ⋮               | ⋮         |        |       |    |                 |    |    |    |    |    |    |    |    |    |    |       |      |      |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
+| (0)11           | 13              | 1         |        |       |    | TSOH TS4        |    |    |    |    |    |    |    |    |    |    |       |      |      |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
+|                 | 14              | 2         |        |       |    |                 |    |    |    |    |    |    |    |    |    |    |       |      |      |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
+|                 | 15              | 3         |        |       |    |                 |    |    |    |    |    |    |    |    |    |    |       |      |      |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
+|                 | 16              | 4         |        |       |    |                 |    |    |    |    |    |    |    |    |    |    |       |      |      |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
+| (1)00           | 17              | 1         |        |       |    | TSOH TS1 or TS5 |    |    |    |    |    |    |    |    |    |    |       |      |      |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
+|                 | 18              | 2         |        |       |    |                 |    |    |    |    |    |    |    |    |    |    |       |      |      |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
+|                 | 19              | 3         |        |       |    |                 |    |    |    |    |    |    |    |    |    |    |       |      |      |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
+|                 | 20              | 4         |        |       |    |                 |    |    |    |    |    |    |    |    |    |    |       |      |      |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
+|                 | ⋮               | ⋮         |        |       |    |                 |    |    |    |    |    |    |    |    |    |    |       |      |      |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
+| (1)11           | 29              | 13        |        |       |    | TSOH TS4 or TS8 |    |    |    |    |    |    |    |    |    |    |       |      |      |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
+|                 | 30              | 14        |        |       |    |                 |    |    |    |    |    |    |    |    |    |    |       |      |      |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
+|                 | 31              | 15        |        |       |    |                 |    |    |    |    |    |    |    |    |    |    |       |      |      |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
+|                 | 32              | 16        |        |       |    |                 |    |    |    |    |    |    |    |    |    |    |       |      |      |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
+
+G.709-Y.1331(12)\_F19-1
+
+Figure 19-1 – OPU2 tributary slot allocation
+
+**Table 19-1 – OPU2 tributary slot OH allocation**
+
+| MFAS<br>bits<br>7 8 | TSOH<br>2.5G TS | MFAS<br>bits<br>6 7 8 | TSOH<br>1.25G TS |
+|---------------------|-----------------|-----------------------|------------------|
+| 0 0                 | 1               | 0 0 0                 | 1                |
+| 0 1                 | 2               | 0 0 1                 | 2                |
+| 1 0                 | 3               | 0 1 0                 | 3                |
+| 1 1                 | 4               | 0 1 1                 | 4                |
+|                     |                 | 1 0 0                 | 5                |
+|                     |                 | 1 0 1                 | 6                |
+|                     |                 | 1 1 0                 | 7                |
+|                     |                 | 1 1 1                 | 8                |
+
+### 19.1.2 OPU3 tributary slot allocation
+
+Figure 19-2 presents the OPU3 2.5G tributary slot allocation and the OPU3 1.25G tributary slot allocation. An OPU3 is divided into sixteen 2.5G tributary slots numbered 1 to 16, or in thirty-two 1.25G tributary slots numbered 1 to 32.
+
+- An OPU3 2.5G tributary slot occupies 6.25% of the OPU3 payload area. It is a structure with 238 columns by 64 ( $16 \times 4$ ) rows (see Figures 19-2 and 19-8) plus a tributary slot overhead (TSOH). The sixteen OPU3 2.5G TSs are byte interleaved in the OPU3 payload area and the sixteen OPU3 TSOHs are frame interleaved in the OPU3 overhead area.
+- An OPU3 1.25G tributary slot occupies 3.125% of the OPU3 payload area. It is a structure with 119 columns by 128 ( $32 \times 4$ ) rows (see Figures 19-2 and 19-8) plus a tributary slot overhead (TSOH). The thirty-two OPU3 1.25G TSs are byte interleaved in the OPU3 payload area and the thirty-two OPU3 TSOHs are frame interleaved in the OPU3 overhead area.
+
+An OPU3 2.5G tributary slot "i" ( $i = 1, 2, \dots, 16$ ) is provided by two OPU3 1.25G tributary slots "i" and "i+16" as illustrated in Figure 19-2.
+
+The tributary slot overhead (TSOH) of OPU3 tributary slots is located in column 16 plus column 15, rows 1, 2 and 3 of the OPU3 frame.
+
+The TSOH for a 2.5G tributary slot is available once every 16 frames. A 16-frame multiframe structure is used for this assignment. This multiframe structure is locked to bits 5, 6, 7 and 8 of the MFAS byte as shown in Table 19-2 and Figure 19-2.
+
+The TSOH for a 1.25G tributary slot is available once every 32 frames. A 32-frame multiframe structure is used for this assignment. This multiframe structure is locked to bits 4, 5, 6, 7 and 8 of the MFAS byte as shown in Table 19-2 and Figure 19-2.
+
+| MFAS bits (4)5678 | Multi-frame row | Frame row | Column |       |    |                   |    |    |       |    |    |    |    |       |    |    |    |    |       |      |      |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
+|-------------------|-----------------|-----------|--------|-------|----|-------------------|----|----|-------|----|----|----|----|-------|----|----|----|----|-------|------|------|--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|
+|                   |                 |           | 1      | ..... | 15 | 16                | 17 | 18 | ..... | 31 | 32 | 33 | 34 | ..... | 47 | 48 | 49 | 50 | ..... | 3823 | 3824 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
+| (0)0000           | 1               | 1         |        |       |    | TSOH TS1          |    |    | ..... |    |    |    |    | ..... |    |    |    |    | ..... |      |      |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
+|                   | 2               | 2         |        |       |    |                   |    |    | ..... |    |    |    |    | ..... |    |    |    |    | ..... |      |      |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
+|                   | 3               | 3         |        |       |    |                   |    |    | ..... |    |    |    |    | ..... |    |    |    |    | ..... |      |      |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
+|                   | 4               | 4         |        |       |    |                   |    |    | ..... |    |    |    |    | ..... |    |    |    |    | ..... |      |      |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
+| (0)0001           | 5               | 1         |        |       |    | TSOH TS2          |    |    | ..... |    |    |    |    | ..... |    |    |    |    | ..... |      |      |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
+|                   | 6               | 2         |        |       |    |                   |    |    | ..... |    |    |    |    | ..... |    |    |    |    | ..... |      |      |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
+|                   | 7               | 3         |        |       |    |                   |    |    | ..... |    |    |    |    | ..... |    |    |    |    | ..... |      |      |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
+|                   | 8               | 4         |        |       |    |                   |    |    | ..... |    |    |    |    | ..... |    |    |    |    | ..... |      |      |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
+| (0)1111           | 61              | 1         |        |       |    | TSOH TS16         |    |    | ..... |    |    |    |    | ..... |    |    |    |    | ..... |      |      |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
+|                   | 62              | 2         |        |       |    |                   |    |    | ..... |    |    |    |    | ..... |    |    |    |    | ..... |      |      |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
+|                   | 63              | 3         |        |       |    |                   |    |    | ..... |    |    |    |    | ..... |    |    |    |    | ..... |      |      |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
+|                   | 64              | 4         |        |       |    |                   |    |    | ..... |    |    |    |    | ..... |    |    |    |    | ..... |      |      |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
+| (1)0000           | 65              | 1         |        |       |    | TSOH TS1 or TS17  |    |    | ..... |    |    |    |    | ..... |    |    |    |    | ..... |      |      |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
+|                   | 66              | 2         |        |       |    |                   |    |    | ..... |    |    |    |    | ..... |    |    |    |    | ..... |      |      |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
+|                   | 67              | 3         |        |       |    |                   |    |    | ..... |    |    |    |    | ..... |    |    |    |    | ..... |      |      |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
+|                   | 68              | 4         |        |       |    |                   |    |    | ..... |    |    |    |    | ..... |    |    |    |    | ..... |      |      |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
+| (1)1111           | 125             | 61        |        |       |    | TSOH TS16 or TS32 |    |    | ..... |    |    |    |    | ..... |    |    |    |    | ..... |      |      |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
+|                   | 126             | 62        |        |       |    |                   |    |    | ..... |    |    |    |    | ..... |    |    |    |    | ..... |      |      |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
+|                   | 127             | 63        |        |       |    |                   |    |    | ..... |    |    |    |    | ..... |    |    |    |    | ..... |      |      |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
+|                   | 128             | 64        |        |       |    |                   |    |    | ..... |    |    |    |    | ..... |    |    |    |    | ..... |      |      |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
+
+G.709-Y.1331(12)\_F19-2
+
+Figure 19-2 – OPU3 tributary slot allocation
+
+**Table 19-2 – OPU3 tributary slot OH allocation**
+
+| MFAS bits<br>5 6 7 8 | TSOH<br>2.5G TS | MFAS bits<br>4 5 6 7 8 | TSOH<br>1.25G TS | MFAS bits<br>4 5 6 7 8 | TSOH<br>1.25G TS |
+|----------------------|-----------------|------------------------|------------------|------------------------|------------------|
+| 0 0 0 0              | 1               | 0 0 0 0 0              | 1                | 1 0 0 0 0              | 17               |
+| 0 0 0 1              | 2               | 0 0 0 0 1              | 2                | 1 0 0 0 1              | 18               |
+| 0 0 1 0              | 3               | 0 0 0 1 0              | 3                | 1 0 0 1 0              | 19               |
+| 0 0 1 1              | 4               | 0 0 0 1 1              | 4                | 1 0 0 1 1              | 20               |
+| 0 1 0 0              | 5               | 0 0 1 0 0              | 5                | 1 0 1 0 0              | 21               |
+| 0 1 0 1              | 6               | 0 0 1 0 1              | 6                | 1 0 1 0 1              | 22               |
+| 0 1 1 0              | 7               | 0 0 1 1 0              | 7                | 1 0 1 1 0              | 23               |
+| 0 1 1 1              | 8               | 0 0 1 1 1              | 8                | 1 0 1 1 1              | 24               |
+| 1 0 0 0              | 9               | 0 1 0 0 0              | 9                | 1 1 0 0 0              | 25               |
+| 1 0 0 1              | 10              | 0 1 0 0 1              | 10               | 1 1 0 0 1              | 26               |
+| 1 0 1 0              | 11              | 0 1 0 1 0              | 11               | 1 1 0 1 0              | 27               |
+| 1 0 1 1              | 12              | 0 1 0 1 1              | 12               | 1 1 0 1 1              | 28               |
+| 1 1 0 0              | 13              | 0 1 1 0 0              | 13               | 1 1 1 0 0              | 29               |
+| 1 1 0 1              | 14              | 0 1 1 0 1              | 14               | 1 1 1 0 1              | 30               |
+| 1 1 1 0              | 15              | 0 1 1 1 0              | 15               | 1 1 1 1 0              | 31               |
+| 1 1 1 1              | 16              | 0 1 1 1 1              | 16               | 1 1 1 1 1              | 32               |
+
+### 19.1.3 OPU1 tributary slot allocation
+
+Figure 19-3 presents the OPU1 1.25G tributary slot allocation. An OPU1 is divided into two 1.25G tributary slots numbered 1 to 2.
+
+- An OPU1 1.25G tributary slot occupies 50% of the OPU1 payload area. It is a structure with 1904 columns by 8 ( $2 \times 4$ ) rows (see Figure 19-3) plus a tributary slot overhead (TSOH). The two OPU1 1.25G TSs are byte interleaved in the OPU1 payload area and the two OPU1 TSOHs are frame interleaved in the OPU1 overhead area.
+
+The tributary slot overhead (TSOH) of OPU1 tributary slots is located in column 16 plus column 15, rows 1, 2 and 3 of the OPU1 frame.
+
+The TSOH for a 1.25G tributary slot is available once every 2 frames. A 2-frame multiframe structure is used for this assignment. This multiframe structure is locked to bit 8 of the MFAS byte as shown in Table 19-3 and Figure 19-3.
+
+![Figure 19-3 – OPU1 tributary slot allocation diagram. It shows a grid of columns (1 to 3824) and rows (1 to 8). Columns 15 and 16 are highlighted as TSOH for TS1 and TS2. Columns 17 to 20 are highlighted as payload for TS1 and TS2. Columns 3823 and 3824 are highlighted as payload for 1.25G TS#. The diagram is labeled G.709-Y.1331(12)_F19-3.](f2b561f8d2d2b8402379552179d9fbef_img.jpg)
+
+The diagram illustrates the OPU1 tributary slot allocation. It features a grid with columns numbered 1, ..., 15, 16, 17, 18, 19, 20, ..., 3823, 3824. Rows are numbered 1 to 8. Columns 15 and 16 are designated as TSOH (Tributary Slot Overhead) for TS1 and TS2. Columns 17 to 20 are designated as payload for TS1 and TS2. Columns 3823 and 3824 are designated as payload for 1.25G TS#. The diagram is labeled G.709-Y.1331(12)\_F19-3.
+
+Figure 19-3 – OPU1 tributary slot allocation diagram. It shows a grid of columns (1 to 3824) and rows (1 to 8). Columns 15 and 16 are highlighted as TSOH for TS1 and TS2. Columns 17 to 20 are highlighted as payload for TS1 and TS2. Columns 3823 and 3824 are highlighted as payload for 1.25G TS#. The diagram is labeled G.709-Y.1331(12)\_F19-3.
+
+**Figure 19-3 – OPU1 tributary slot allocation**
+
+**Table 19-3 – OPU1 tributary slot OH allocation**
+
+| MFAS<br>bit 8 | TSOH 1.25G TS |
+|---------------|---------------|
+| 0             | 1             |
+| 1             | 2             |
+
+### 19.1.4 OPU4 tributary slot allocation
+
+Figures 19-4A and 19-4B present the OPU4 1.25G tributary slot allocation. An OPU4 is divided into eighty 1.25G tributary slots (numbered 1 to 80), which are located in columns 17 to 3816, and 8 columns of fixed stuff located in columns 3817 to 3824. The OPU4 frame may be represented in a 320 row by 3810 column format (Figure 19-4A) and in a 160 row by 7620 column format (Figure 19-4B).
+
+- An OPU4 1.25G tributary slot occupies 1.247% of the OPU4 payload area. It is a structure with 95 columns by 160 ( $80 \times 4/2$ ) rows (see Figure 19-4B) plus a tributary slot overhead (TSOH). The eighty OPU4 1.25G TSs are byte interleaved in the OPU4 payload area and the eighty OPU4 TSOHs are frame interleaved in the OPU4 overhead area.
+
+The tributary slot overhead (TSOH) of OPU4 tributary slots is located in rows 1 to 3, columns 15 and 16 of the OPU4 frame.
+
+The TSOH for a 1.25G tributary slot is available once every 80 frames. An 80-frame multiframe structure is used for this assignment. This multiframe structure is locked to bits 2, 3, 4, 5, 6, 7 and 8 of the OMFI byte as shown in Table 19-4.
+
+| OMFI bits<br>2345678 | Multi-frame row | Frame row | Column |       |    |              |          |    |       |    |    |    |    |       |    |    |    |    |       |      |      |      |      |      |      |      |      |      |      |
+|----------------------|-----------------|-----------|--------|-------|----|--------------|----------|----|-------|----|----|----|----|-------|----|----|----|----|-------|------|------|------|------|------|------|------|------|------|------|
+|                      |                 |           | 1      | ..... | 15 | 16           | 17       | 18 | ..... | 55 | 56 | 57 | 58 | ..... | 95 | 96 | 97 | 98 | ..... | 3815 | 3816 | 3817 | 3818 | 3819 | 3820 | 3821 | 3822 | 3823 | 3824 |
+| 0000000              | 1               | 1         |        |       |    | TSOH<br>TS1  | 1        | 2  |       | 39 | 40 | 41 | 42 |       | 79 | 80 | 1  | 2  |       | 39   | 40   | FS   | FS   | FS   | FS   | FS   | FS   | FS   | FS   |
+|                      | 2               | 2         |        |       |    |              | 41       | 42 | ..... | 79 | 80 | 1  | 2  | ..... | 39 | 40 | 41 | 42 |       | 79   | 80   | FS   | FS   | FS   | FS   | FS   | FS   | FS   | FS   |
+|                      | 3               | 3         |        |       |    |              | 1        | 2  |       | 39 | 40 | 41 | 42 |       | 79 | 80 | 1  | 2  |       | 39   | 40   | FS   | FS   | FS   | FS   | FS   | FS   | FS   | FS   |
+|                      | 4               | 4         |        |       |    | PSI          | OM<br>FI | 41 | 42    |    | 79 | 80 | 1  | 2     |    | 39 | 40 | 41 | 42    |      | 79   | 80   | FS   | FS   | FS   | FS   | FS   | FS   | FS   |
+| 0000001              | 5               | 1         |        |       |    | TSOH<br>TS2  | 1        | 2  |       | 39 | 40 | 41 | 42 |       | 79 | 80 | 1  | 28 |       | 39   | 40   | FS   | FS   | FS   | FS   | FS   | FS   | FS   | FS   |
+|                      | 6               | 2         |        |       |    |              | 41       | 42 | ..... | 79 | 80 | 1  | 2  | ..... | 39 | 40 | 41 | 42 |       | 79   | 80   | FS   | FS   | FS   | FS   | FS   | FS   | FS   | FS   |
+|                      | 7               | 3         |        |       |    |              | 1        | 2  |       | 39 | 40 | 41 | 42 |       | 79 | 80 | 1  | 2  |       | 39   | 40   | FS   | FS   | FS   | FS   | FS   | FS   | FS   | FS   |
+|                      | 8               | 4         |        |       |    | PSI          | OM<br>FI | 41 | 42    |    | 79 | 80 | 1  | 2     |    | 39 | 40 | 41 | 42    |      | 79   | 80   | FS   | FS   | FS   | FS   | FS   | FS   | FS   |
+|                      | ⋮               |           |        |       |    |              |          |    |       |    |    |    |    |       |    |    |    |    |       |      |      |      |      |      |      |      |      |      |      |
+| 1001110              | 313             | 1         |        |       |    | TSOH<br>TS79 | 1        | 2  |       | 39 | 40 | 41 | 42 |       | 79 | 80 | 1  | 2  |       | 39   | 40   | FS   | FS   | FS   | FS   | FS   | FS   | FS   | FS   |
+|                      | 314             | 2         |        |       |    |              | 41       | 42 | ..... | 79 | 80 | 1  | 2  | ..... | 39 | 40 | 41 | 42 |       | 79   | 80   | FS   | FS   | FS   | FS   | FS   | FS   | FS   | FS   |
+|                      | 315             | 3         |        |       |    |              | 1        | 2  |       | 39 | 40 | 41 | 42 |       | 79 | 80 | 1  | 2  |       | 39   | 40   | FS   | FS   | FS   | FS   | FS   | FS   | FS   | FS   |
+|                      | 316             | 4         |        |       |    | PSI          | OM<br>FI | 41 | 42    |    | 79 | 80 | 1  | 2     |    | 39 | 40 | 41 | 42    |      | 79   | 80   | FS   | FS   | FS   | FS   | FS   | FS   | FS   |
+| 1001111              | 317             | 1         |        |       |    | TSOH<br>TS80 | 1        | 2  |       | 39 | 40 | 41 | 42 |       | 79 | 80 | 1  | 2  |       | 39   | 40   | FS   | FS   | FS   | FS   | FS   | FS   | FS   | FS   |
+|                      | 318             | 2         |        |       |    |              | 41       | 42 | ..... | 79 | 80 | 1  | 2  | ..... | 39 | 40 | 41 | 42 |       | 79   | 80   | FS   | FS   | FS   | FS   | FS   | FS   | FS   | FS   |
+|                      | 319             | 3         |        |       |    |              | 1        | 2  |       | 39 | 40 | 41 | 42 |       | 79 | 80 | 1  | 2  |       | 39   | 40   | FS   | FS   | FS   | FS   | FS   | FS   | FS   | FS   |
+|                      | 320             | 4         |        |       |    | PSI          | OM<br>FI | 41 | 42    |    | 79 | 80 | 1  | 2     |    | 39 | 40 | 41 | 42    |      | 79   | 80   | FS   | FS   | FS   | FS   | FS   | FS   | FS   |
+
+G.709-Y.1331(12)\_F19-4A
+
+Figure 19-4A – OPU4 1.25G tributary slot allocation
+
+| OMFI bits<br>2345678 | Multi-frame D-row | Frame row | Column |       |      |    |    |    |       |    |    |    |    |       |      |      |      |      |      |      |      |      |      |      |   |       |                 |    |    |    |       |    |    |    |    |       |      |      |      |      |      |      |      |      |      |      |    |    |
+|----------------------|-------------------|-----------|--------|-------|------|----|----|----|-------|----|----|----|----|-------|------|------|------|------|------|------|------|------|------|------|---|-------|-----------------|----|----|----|-------|----|----|----|----|-------|------|------|------|------|------|------|------|------|------|------|----|----|
+|                      |                   |           | 1      | ..... | 15   | 16 | 17 | 18 | ..... | 95 | 96 | 97 | 98 | ..... | 3815 | 3816 | 3817 | 3818 | 3819 | 3820 | 3821 | 3822 | 3823 | 3824 | 1 | ..... | 15              | 16 | 17 | 18 | ..... | 55 | 56 | 57 | 58 | ..... | 3815 | 3816 | 3817 | 3818 | 3819 | 3820 | 3821 | 3822 | 3823 | 3824 |    |    |
+| 0000000              | 1                 | 1 + 2     |        |       | TS1  | 1  | 2  |    |       | 79 | 80 | 1  | 2  |       | 39   | 40   | FS   | FS   | FS   | FS   | FS   | FS   | FS   | FS   |   |       | TS1             | 41 | 42 |    |       | 79 | 80 | 1  | 2  |       | 79   | 80   | FS   | FS   | FS   | FS   | FS   | FS   | FS   | FS   | FS | FS |
+|                      | 2                 | 3 + 4     |        |       |      | 1  | 2  |    |       | 79 | 80 | 1  | 2  |       | 39   | 40   | FS   | FS   | FS   | FS   | FS   | FS   | FS   | FS   |   |       | PSI<br>OM<br>FI | 41 | 42 |    |       | 79 | 80 | 1  | 2  |       | 79   | 80   | FS   | FS   | FS   | FS   | FS   | FS   | FS   | FS   | FS | FS |
+| 0000001              | 3                 | 1 + 2     |        |       | TS2  | 1  | 2  |    |       | 79 | 80 | 1  | 2  |       | 39   | 40   | FS   | FS   | FS   | FS   | FS   | FS   | FS   | FS   |   |       | TS2             | 41 | 42 |    |       | 79 | 80 | 1  | 2  |       | 79   | 80   | FS   | FS   | FS   | FS   | FS   | FS   | FS   | FS   | FS | FS |
+|                      | 4                 | 3 + 4     |        |       |      | 1  | 2  |    |       | 79 | 80 | 1  | 2  |       | 39   | 40   | FS   | FS   | FS   | FS   | FS   | FS   | FS   | FS   |   |       | PSI<br>OM<br>FI | 41 | 42 |    |       | 79 | 80 | 1  | 2  |       | 79   | 80   | FS   | FS   | FS   | FS   | FS   | FS   | FS   | FS   | FS | FS |
+|                      |                   | ⋮         |        |       |      |    |    |    |       |    |    |    |    |       |      |      |      |      |      |      |      |      |      |      |   |       |                 |    |    |    |       |    |    |    |    |       |      |      |      |      |      |      |      |      |      |      |    |    |
+| 1001110              | 157               | 1 + 2     |        |       | TS79 | 1  | 2  |    |       | 79 | 80 | 1  | 2  |       | 39   | 40   | FS   | FS   | FS   | FS   | FS   | FS   | FS   | FS   |   |       | TS79            | 41 | 42 |    |       | 79 | 80 | 1  | 2  |       | 79   | 80   | FS   | FS   | FS   | FS   | FS   | FS   | FS   | FS   | FS | FS |
+|                      | 158               | 3 + 4     |        |       |      | 1  | 2  |    |       | 79 | 80 | 1  | 2  |       | 39   | 40   | FS   | FS   | FS   | FS   | FS   | FS   | FS   | FS   |   |       | PSI<br>OM<br>FI | 41 | 42 |    |       | 79 | 80 | 1  | 2  |       | 79   | 80   | FS   | FS   | FS   | FS   | FS   | FS   | FS   | FS   | FS | FS |
+| 1001111              | 159               | 1 + 2     |        |       | TS80 | 1  | 2  |    |       | 79 | 80 | 1  | 2  |       | 39   | 40   | FS   | FS   | FS   | FS   | FS   | FS   | FS   | FS   |   |       | TS80            | 41 | 42 |    |       | 79 | 80 | 1  | 2  |       | 79   | 80   | FS   | FS   | FS   | FS   | FS   | FS   | FS   | FS   | FS | FS |
+|                      | 160               | 3 + 4     |        |       |      | 1  | 2  |    |       | 79 | 80 | 1  | 2  |       | 39   | 40   | FS   | FS   | FS   | FS   | FS   | FS   | FS   | FS   |   |       | PSI<br>OM<br>FI | 41 | 42 |    |       | 79 | 80 | 1  | 2  |       | 79   | 80   | FS   | FS   | FS   | FS   | FS   | FS   | FS   | FS   | FS | FS |
+
+G.709-Y.1331(12)\_F19-4B
+
+Figure 19-4B – OPU4 tributary slots in 160 row x 7620 column format
+
+**Table 19-4 – OPU4 tributary slot OH allocation**
+
+| OMFI bits<br>2 3 4 5 6 7 8 | TSOH<br>1.25G TS | OMFI bits<br>2 3 4 5 6 7 8 | TSOH<br>1.25G TS | OMFI bits<br>2 3 4 5 6 7 8 | TSOH<br>1.25G TS | OMFI bits<br>2 3 4 5 6 7 8 | TSOH<br>1.25G TS |
+|----------------------------|------------------|----------------------------|------------------|----------------------------|------------------|----------------------------|------------------|
+| 0 0 0 0 0 0 0              | 1                | 0 0 1 0 1 0 0              | 21               | 0 1 0 1 0 0 0              | 41               | 0 1 1 1 1 0 0              | 61               |
+| 0 0 0 0 0 0 1              | 2                | 0 0 1 0 1 0 1              | 22               | 0 1 0 1 0 0 1              | 42               | 0 1 1 1 1 0 1              | 62               |
+| 0 0 0 0 0 1 0              | 3                | 0 0 1 0 1 1 0              | 23               | 0 1 0 1 0 1 0              | 43               | 0 1 1 1 1 1 0              | 63               |
+| 0 0 0 0 0 1 1              | 4                | 0 0 1 0 1 1 1              | 24               | 0 1 0 1 0 1 1              | 44               | 0 1 1 1 1 1 1              | 64               |
+| 0 0 0 0 1 0 0              | 5                | 0 0 1 1 0 0 0              | 25               | 0 1 0 1 1 0 0              | 45               | 1 0 0 0 0 0 0              | 65               |
+| 0 0 0 0 1 0 1              | 6                | 0 0 1 1 0 0 1              | 26               | 0 1 0 1 1 0 1              | 46               | 1 0 0 0 0 0 1              | 66               |
+| 0 0 0 0 1 1 0              | 7                | 0 0 1 1 0 1 0              | 27               | 0 1 0 1 1 1 0              | 47               | 1 0 0 0 0 1 0              | 67               |
+| 0 0 0 0 1 1 1              | 8                | 0 0 1 1 0 1 1              | 28               | 0 1 0 1 1 1 1              | 48               | 1 0 0 0 0 1 1              | 68               |
+| 0 0 0 1 0 0 0              | 9                | 0 0 1 1 1 0 0              | 29               | 0 1 1 0 0 0 0              | 49               | 1 0 0 0 1 0 0              | 69               |
+| 0 0 0 1 0 0 1              | 10               | 0 0 1 1 1 0 1              | 30               | 0 1 1 0 0 0 1              | 50               | 1 0 0 0 1 0 1              | 70               |
+| 0 0 0 1 0 1 0              | 11               | 0 0 1 1 1 1 0              | 31               | 0 1 1 0 0 1 0              | 51               | 1 0 0 0 1 1 0              | 71               |
+| 0 0 0 1 0 1 1              | 12               | 0 0 1 1 1 1 1              | 32               | 0 1 1 0 0 1 1              | 52               | 1 0 0 0 1 1 1              | 72               |
+| 0 0 0 1 1 0 0              | 13               | 0 1 0 0 0 0 0              | 33               | 0 1 1 0 1 0 0              | 53               | 1 0 0 1 0 0 0              | 73               |
+| 0 0 0 1 1 0 1              | 14               | 0 1 0 0 0 0 1              | 34               | 0 1 1 0 1 0 1              | 54               | 1 0 0 1 0 0 1              | 74               |
+| 0 0 0 1 1 1 0              | 15               | 0 1 0 0 0 1 0              | 35               | 0 1 1 0 1 1 0              | 55               | 1 0 0 1 0 1 0              | 75               |
+| 0 0 0 1 1 1 1              | 16               | 0 1 0 0 0 1 1              | 36               | 0 1 1 0 1 1 1              | 56               | 1 0 0 1 0 1 1              | 76               |
+| 0 0 1 0 0 0 0              | 17               | 0 1 0 0 1 0 0              | 37               | 0 1 1 1 0 0 0              | 57               | 1 0 0 1 1 0 0              | 77               |
+| 0 0 1 0 0 0 1              | 18               | 0 1 0 0 1 0 1              | 38               | 0 1 1 1 0 0 1              | 58               | 1 0 0 1 1 0 1              | 78               |
+| 0 0 1 0 0 1 0              | 19               | 0 1 0 0 1 1 0              | 39               | 0 1 1 1 0 1 0              | 59               | 1 0 0 1 1 1 0              | 79               |
+| 0 0 1 0 0 1 1              | 20               | 0 1 0 0 1 1 1              | 40               | 0 1 1 1 0 1 1              | 60               | 1 0 0 1 1 1 1              | 80               |
+
+### 19.1.5 OPU25 tributary slot allocation
+
+Figures 19-5A and 19-5B present the OPU25 1.25G tributary slot allocation. An OPU25 is divided into twenty 1.25G tributary slots (numbered 1 to 20), which are located in columns 17 to 3824. The OPU25 frame may be represented in an 80 row by 3810 column format (Figure 19-5A) and in a 16 row by 19050 column format (Figure 19-5B).
+
+- An OPU25 1.25G tributary slot occupies 5% of the OPU25 payload area. It is a structure with 952 columns by 16 ( $20 \times 4/5$ ) rows (see Figure 19-5B) plus a tributary slot overhead (TSOH). The twenty OPU25 1.25G TSs are byte interleaved in the OPU25 payload area and the twenty OPU25 TSOHs are frame interleaved in the OPU25 overhead area.
+
+The tributary slot overhead (TSOH) of OPU25 tributary slots is located in rows 1 to 3, columns 15 and 16 of the OPU25 frame.
+
+The TSOH for a 1.25G tributary slot is available once every 20 frames. A 20-frame multiframe structure is used for this assignment. This multiframe structure is locked to bits 4, 5, 6, 7 and 8 of the OMFI byte as shown in Table 19-5.
+
+| OMFI bits 45678 | Multi-frame row | Frame row | Column |           |       |    |    |     |    |    |    |    |     |    |    |    |    |     |      |      |      |      |      |      |      |      |      |      |  |  |
+|-----------------|-----------------|-----------|--------|-----------|-------|----|----|-----|----|----|----|----|-----|----|----|----|----|-----|------|------|------|------|------|------|------|------|------|------|--|--|
+|                 |                 |           | ...    | 15        | 16    | 17 | 18 | ... | 35 | 36 | 37 | 38 | ... | 55 | 56 | 57 | 58 | ... | 3815 | 3816 | 3817 | 3818 | 3819 | 3820 | 3821 | 3822 | 3823 | 3824 |  |  |
+| 00000           | 1               | 1         |        |           |       | 1  | 2  |     | 19 | 20 | 1  | 2  |     | 19 | 20 | 1  | 2  |     | 19   | 20   | 1    | 2    | 3    | 4    | 5    | 6    | 7    | 8    |  |  |
+|                 | 2               | 2         |        | TSOH TS1  |       | 9  | 10 |     | 7  | 8  | 9  | 10 |     | 7  | 8  | 9  | 10 |     | 7    | 8    | 9    | 10   | 11   | 12   | 13   | 14   | 15   | 16   |  |  |
+|                 | 3               | 3         |        |           |       | 17 | 18 |     | 15 | 16 | 17 | 18 |     | 15 | 16 | 17 | 18 |     | 15   | 16   | 17   | 18   | 19   | 20   | 1    | 2    | 3    | 4    |  |  |
+|                 | 4               | 4         |        | PSI       | OM FI | 5  | 6  |     | 3  | 4  | 5  | 6  |     | 3  | 4  | 5  | 6  |     | 3    | 4    | 5    | 6    | 7    | 8    | 9    | 10   | 11   | 12   |  |  |
+| 00001           | 5               | 1         |        |           |       | 13 | 14 |     | 11 | 12 | 13 | 14 |     | 11 | 12 | 13 | 14 |     | 11   | 12   | 13   | 14   | 15   | 16   | 17   | 18   | 19   | 20   |  |  |
+|                 | 6               | 2         |        | TSOH TS2  |       | 1  | 2  |     | 19 | 20 | 1  | 2  |     | 19 | 20 | 1  | 2  |     | 19   | 20   | 1    | 2    | 3    | 4    | 5    | 6    | 7    | 8    |  |  |
+|                 | 7               | 3         |        |           |       | 9  | 10 |     | 7  | 8  | 9  | 10 |     | 7  | 8  | 9  | 10 |     | 7    | 8    | 9    | 10   | 11   | 12   | 13   | 14   | 15   | 16   |  |  |
+|                 | 8               | 4         |        | PSI       | OM FI | 17 | 18 |     | 15 | 16 | 17 | 18 |     | 15 | 16 | 17 | 18 |     | 15   | 16   | 17   | 18   | 19   | 20   | 1    | 2    | 3    | 4    |  |  |
+| ...             |                 |           |        |           |       |    |    |     |    |    |    |    |     |    |    |    |    |     |      |      |      |      |      |      |      |      |      |      |  |  |
+| 10010           | 73              | 1         |        |           |       | 17 | 18 |     | 15 | 16 | 17 | 18 |     | 15 | 16 | 17 | 18 |     | 15   | 16   | 17   | 18   | 19   | 20   | 1    | 2    | 3    | 4    |  |  |
+|                 | 74              | 2         |        | TSOH TS19 |       | 5  | 6  |     | 3  | 4  | 5  | 6  |     | 3  | 4  | 5  | 6  |     | 3    | 4    | 5    | 6    | 7    | 8    | 9    | 10   | 11   | 12   |  |  |
+|                 | 75              | 3         |        |           |       | 13 | 14 |     | 11 | 12 | 13 | 14 |     | 11 | 12 | 13 | 14 |     | 11   | 12   | 13   | 14   | 15   | 16   | 17   | 18   | 19   | 20   |  |  |
+|                 | 76              | 4         |        | PSI       | OM FI | 1  | 2  |     | 19 | 20 | 1  | 2  |     | 19 | 20 | 1  | 2  |     | 19   | 20   | 1    | 2    | 3    | 4    | 5    | 6    | 7    | 8    |  |  |
+| 10011           | 77              | 1         |        |           |       | 9  | 10 |     | 7  | 8  | 9  | 10 |     | 7  | 8  | 9  | 10 |     | 7    | 8    | 9    | 10   | 11   | 12   | 13   | 14   | 15   | 16   |  |  |
+|                 | 78              | 2         |        | TSOH TS20 |       | 17 | 18 |     | 15 | 16 | 17 | 18 |     | 15 | 16 | 17 | 18 |     | 15   | 16   | 17   | 18   | 19   | 20   | 1    | 2    | 3    | 4    |  |  |
+|                 | 79              | 3         |        |           |       | 5  | 6  |     | 3  | 4  | 5  | 6  |     | 3  | 4  | 5  | 6  |     | 3    | 4    | 5    | 6    | 7    | 8    | 9    | 10   | 11   | 12   |  |  |
+|                 | 80              | 4         |        | PSI       | OM FI | 13 | 14 |     | 11 | 12 | 13 | 14 |     | 11 | 12 | 13 | 14 |     | 11   | 12   | 13   | 14   | 15   | 16   | 17   | 18   | 19   | 20   |  |  |
+
+**Figure 19-5A – OPU25 1.25G tributary slot allocation**
+
+| Multi-frame row | Frame row                                        | Column   |          |     |     |     |      |     |     |     |      |  |  |  |  |  |
+|-----------------|--------------------------------------------------|----------|----------|-----|-----|-----|------|-----|-----|-----|------|--|--|--|--|--|
+|                 |                                                  | 15       | 16       | 17  | 18  | ... | 36   | 37  | 38  | ... | 3824 |  |  |  |  |  |
+| 1               | 1, 2(1 <sup>st</sup> 1/4)                        | TSOH #1  | TSOH #2  | TS1 | TS1 | ... | TS20 | TS2 | TS2 | ... | TS20 |  |  |  |  |  |
+| 2               | 2(last 3/4), 3(1 <sup>st</sup> 1/2)              | TSOH #3  | TSOH #4  | TS1 | TS1 | ... | TS20 | TS2 | TS2 | ... | TS20 |  |  |  |  |  |
+| 3               | 3(2 <sup>nd</sup> 1/2), 4(1 <sup>st</sup> 3/4)   | TSOH #5  | PSI OMFI | TS1 | TS1 | ... | TS20 | TS2 | TS2 | ... | TS20 |  |  |  |  |  |
+| 4               | 4(4 <sup>th</sup> 1/4), 5                        | PSI OMFI | TSOH #6  | TS1 | TS1 | ... | TS20 | TS2 | TS2 | ... | TS20 |  |  |  |  |  |
+| 5               | 6, 7(1 <sup>st</sup> 1/4)                        | TSOH #7  | TSOH #8  | TS1 | TS1 | ... | TS20 | TS2 | TS2 | ... | TS20 |  |  |  |  |  |
+| ...             |                                                  |          |          |     |     |     |      |     |     |     |      |  |  |  |  |  |
+| 15              | 78(2 <sup>nd</sup> 1/2), 79(1 <sup>st</sup> 3/4) | TSOH #18 | PSI OMFI | TS1 | TS1 | ... | TS20 | TS2 | TS2 | ... | TS20 |  |  |  |  |  |
+| 16              | 79(4 <sup>th</sup> 1/4), 80                      | PSI OMFI | TSOH #19 | TS1 | TS1 | ... | TS20 | TS2 | TS2 | ... | TS20 |  |  |  |  |  |
+
+**Figure 19-5B – OPU25 tributary slots in 16 row x 19050 column format**
+
+Rec. ITU-T G.709/Y.1331 (06/2020)
+
+125
+
+**Table 19-5 – OPU25 tributary slot OH allocation**
+
+| OMFI bits<br>4 5 6 7 8 | TSOH<br>1.25G TS |
+|------------------------|------------------|
+| 0 0 0 0 0              | 1                |
+| 0 0 0 0 1              | 2                |
+| 0 0 0 1 0              | 3                |
+| 0 0 0 1 1              | 4                |
+| 0 0 1 0 0              | 5                |
+| 0 0 1 0 1              | 6                |
+| 0 0 1 1 0              | 7                |
+| 0 0 1 1 1              | 8                |
+| 0 1 0 0 0              | 9                |
+| 0 1 0 0 1              | 10               |
+| 0 1 0 1 0              | 11               |
+| 0 1 0 1 1              | 12               |
+| 0 1 1 0 0              | 13               |
+| 0 1 1 0 1              | 14               |
+| 0 1 1 1 0              | 15               |
+| 0 1 1 1 1              | 16               |
+| 1 0 0 0 0              | 17               |
+| 1 0 0 0 1              | 18               |
+| 1 0 0 1 0              | 19               |
+| 1 0 0 1 1              | 20               |
+
+**19.1.6 OPU50 tributary slot allocation**
+
+Figures 19-6A and 19-6B present the OPU50 1.25G tributary slot allocation. An OPU50 is divided into forty 1.25G tributary slots (numbered 1 to 40), which are located in columns 17 to 3824. The OPU50 frame may be represented in a 160 row by 3810 column format (Figure 19-6A) and in a 32 row by 19050 column format (Figure 19-6B).
+
+- An OPU25 1.25G tributary slot occupies 2.5% of the OPU50 payload area. It is a structure with 476 columns by 32 ( $40 \times 4/5$ ) rows (see Figure 19-6B) plus a tributary slot overhead (TSOH). The forty OPU50 1.25G TSs are byte interleaved in the OPU50 payload area and the forty OPU25 TSOHs are frame interleaved in the OPU25 overhead area.
+
+The tributary slot overhead (TSOH) of OPU50 tributary slots is located in rows 1 to 3, columns 15 and 16 of the OPU25 frame.
+
+The TSOH for a 1.25G tributary slot is available once every 40 frames. A 40-frame multiframe structure is used for this assignment. This multiframe structure is locked to bits 3, 4, 5, 6, 7 and 8 of the OMFI byte as shown in Table 19-6.
+
+
+
+**Table 19-6 – OPU50 tributary slot OH allocation**
+
+| OMFI bits<br>3 4 5 6 7 8 | TSOH<br>1.25G TS | OMFI bits<br>3 4 5 6 7 8 | TSOH<br>1.25G TS |
+|--------------------------|------------------|--------------------------|------------------|
+| 0 0 0 0 0 0              | 1                | 0 1 0 1 0 0              | 21               |
+| 0 0 0 0 0 1              | 2                | 0 1 0 1 0 1              | 22               |
+| 0 0 0 0 1 0              | 3                | 0 1 0 1 1 0              | 23               |
+| 0 0 0 0 1 1              | 4                | 0 1 0 1 1 1              | 24               |
+| 0 0 0 1 0 0              | 5                | 0 1 1 0 0 0              | 25               |
+| 0 0 0 1 0 1              | 6                | 0 1 1 0 0 1              | 26               |
+| 0 0 0 1 1 0              | 7                | 0 1 1 0 1 0              | 27               |
+| 0 0 0 1 1 1              | 8                | 0 1 1 0 1 1              | 28               |
+| 0 0 1 0 0 0              | 9                | 0 1 1 1 0 0              | 29               |
+| 0 0 1 0 0 1              | 10               | 0 1 1 1 0 1              | 30               |
+| 0 0 1 0 1 0              | 11               | 0 1 1 1 1 0              | 31               |
+| 0 0 1 0 1 1              | 12               | 0 1 1 1 1 1              | 32               |
+| 0 0 1 1 0 0              | 13               | 1 0 0 0 0 0              | 33               |
+| 0 0 1 1 0 1              | 14               | 1 0 0 0 0 1              | 34               |
+| 0 0 1 1 1 0              | 15               | 1 0 0 0 1 0              | 35               |
+| 0 0 1 1 1 1              | 16               | 1 0 0 0 1 1              | 36               |
+| 0 1 0 0 0 0              | 17               | 1 0 0 1 0 0              | 37               |
+| 0 1 0 0 0 1              | 18               | 1 0 0 1 0 1              | 38               |
+| 0 1 0 0 1 0              | 19               | 1 0 0 1 1 0              | 39               |
+| 0 1 0 0 1 1              | 20               | 1 0 0 1 1 1              | 40               |
+
+## 19.2 ODTU definition
+
+The optical data tributary unit (ODTU) carries a justified ODU signal. There are two types of ODTUs:
+
+- 1) ODTUjk ((j,k) = {(0,1), (1,2), (1,3), (2,3)}; ODTU01, ODTU12, ODTU13 and ODTU23) in which an ODUj signal is mapped via the asynchronous mapping procedure (AMP) as defined in clause 19.5;
+- 2) ODTUk.ts ((k,ts) = (2,1..8), (3,1..32), (4,1..80), (25,1..20), (50,1..40)) in which a ODUj (ODU0, ODU1, ODU2, ODU2e, ODU3, ODUflex) signal is mapped via the generic mapping procedure (GMP) defined in clause 19.6.
+
+### Optical data tributary unit jk
+
+The optical data tributary unit jk (ODTUjk) is a structure which consists of an ODTUjk payload area and an ODTUjk overhead area (Figure 19-7). The ODTUjk payload area has c columns and r rows (see Table 19-7) and the ODTUjk overhead area has "ts" times 4 bytes, of which "ts" times 1 byte can carry payload. The ODTUjk is carried in "ts" 1.25G or 2.5G tributary slots of an OPUk.
+
+The location of the ODTUjk overhead depends on the OPUk tributary slot(s) used when multiplexing the ODTUjk in the OPUk (see clauses 19.1.1, 19.1.2, 19.1.3). The ts instances of the ODTUjk overhead might not be equally distributed.
+
+The ODTUjk overhead carries the AMP justification overhead as specified in clause 19.4.
+
+NOTE – The 1.25G and 2.5G tributary slot versions of an ODTU12 are identical when the two 1.25G tributary slots carrying the ODTU12 are TSa and TSa+4. The 1.25G and 2.5G tributary slot versions of an ODTU13 are identical when the two 1.25G tributary slots carrying the ODTU12 are TSa and TSa+16. The 1.25G and 2.5G tributary slot versions of an ODTU23 are identical when the eight 1.25G tributary slots carrying the ODTU23 are TSa, TSb, TSc, TSd, TSa+16, TSb+16, TSc+16 and TSd+16.
+
+![Figure 19-7 – ODTUjk frame formats. A diagram showing the frame structure with columns 1 to c and rows 1 to r. The first column is labeled 'ODTUjk overhead' and contains a vertical stack of cells. The main body is labeled 'ODTUjk payload'. The diagram is labeled 'jk = 01, 12, 13, 23' and 'G.709-Y.1331(20)_F19-7'.](4c63a0e17b54c7e61d512c276932114c_img.jpg)
+
+The diagram illustrates the ODTUjk frame format. It consists of a grid of cells. The columns are numbered 1, 2, 3, followed by an ellipsis, and then c-1, c. The rows are numbered 1, 2, 3, followed by an ellipsis, and then r-1, r. The first column (column 1) is designated as the 'ODTUjk overhead' and is shown as a vertical stack of cells. The remaining columns (2 through c) form the 'ODTUjk payload'. The frame is identified by the label 'jk = 01, 12, 13, 23' and the source 'G.709-Y.1331(20)\_F19-7'.
+
+Figure 19-7 – ODTUjk frame formats. A diagram showing the frame structure with columns 1 to c and rows 1 to r. The first column is labeled 'ODTUjk overhead' and contains a vertical stack of cells. The main body is labeled 'ODTUjk payload'. The diagram is labeled 'jk = 01, 12, 13, 23' and 'G.709-Y.1331(20)\_F19-7'.
+
+Figure 19-7 – ODTUjk frame formats
+
+Table 19-7 – ODTUjk characteristics for 2.5G and 1.25G tributary slots
+
+| 2.5G TS | c   | r  | ts | ODTUjk payload bytes | ODTUjk overhead bytes |
+|---------|-----|----|----|----------------------|-----------------------|
+| ODTU12  | 952 | 16 | 1  | 15232                | 1 x 4                 |
+| ODTU13  | 238 | 64 | 1  | 15232                | 1 x 4                 |
+| ODTU23  | 952 | 64 | 4  | 60928                | 4 x 4                 |
+
+| 1.25G TS | c    | r   | ts | ODTUjk payload bytes | ODTUjk overhead bytes |
+|----------|------|-----|----|----------------------|-----------------------|
+| ODTU01   | 1904 | 8   | 1  | 15232                | 1 × 4                 |
+| ODTU12   | 952  | 32  | 2  | 30464                | 2 × 4                 |
+| ODTU13   | 238  | 128 | 2  | 30464                | 2 × 4                 |
+| ODTU23   | 952  | 128 | 8  | 121856               | 8 × 4                 |
+
+### Optical data tributary unit k.ts
+
+The optical data tributary unit k.ts (ODTUK.ts) is a structure which consists of an ODTUK.ts payload area and an ODTUK.ts overhead area (Figure 19-8). The ODTUK.ts payload area has j x ts columns and r rows (see Table 19-8) and the ODTUK.ts overhead area has one times 6 bytes. The ODTUK.ts is carried in "ts" 1.25G tributary slots of an OPUk.
+
+The location of the ODTUK.ts overhead depends on the OPUk tributary slot used when multiplexing the ODTUK.ts in the OPUk (see clauses 19.1.1, 19.1.2, 19.1.4, 19.1.5, 19.1.6). The single instance of an ODTUK.ts overhead is located in the OPUk TSOH of the last OPUk tributary slot allocated to the ODTUK.ts.
+
+The ODTUk.ts overhead carries the GMP justification overhead as specified in clause 19.4.
+
+![Figure 19-8 – ODTUk.ts frame formats. The diagram shows a large rectangular frame divided into columns and rows. The columns are labeled at the top: 1, 2, 3, followed by a series of dots, and then two columns labeled 'j ts' and 'j ts-1'. The rows are labeled on the right: 1, 2, 3, followed by a series of dots, and then 'r-1' and 'r'. The central area of the frame is labeled 'ODTUk.ts payload'. To the left of the frame, there is a smaller rectangle labeled 'ODTUk.ts overhead' at the top and 'ts' at the bottom right. This rectangle is divided into two columns and 'k' rows, where 'k = 2, 3, 4'. The text 'G.709-Y.1331(20)_F19-8' is at the bottom right of the diagram.](69d00e8adf9811292427fb2ce6712e39_img.jpg)
+
+Figure 19-8 – ODTUk.ts frame formats. The diagram shows a large rectangular frame divided into columns and rows. The columns are labeled at the top: 1, 2, 3, followed by a series of dots, and then two columns labeled 'j ts' and 'j ts-1'. The rows are labeled on the right: 1, 2, 3, followed by a series of dots, and then 'r-1' and 'r'. The central area of the frame is labeled 'ODTUk.ts payload'. To the left of the frame, there is a smaller rectangle labeled 'ODTUk.ts overhead' at the top and 'ts' at the bottom right. This rectangle is divided into two columns and 'k' rows, where 'k = 2, 3, 4'. The text 'G.709-Y.1331(20)\_F19-8' is at the bottom right of the diagram.
+
+Figure 19-8 – ODTUk.ts frame formats
+
+Table 19-8 – ODTUk.ts characteristics
+
+|                  | j   | r   | ts      | ODTUk.ts payload bytes | ODTUk.ts overhead bytes |
+|------------------|-----|-----|---------|------------------------|-------------------------|
+| <b>ODTU2.ts</b>  | 476 | 32  | 1 to 8  | 15232 × ts             | 1 × 6                   |
+| <b>ODTU3.ts</b>  | 119 | 128 | 1 to 32 | 15232 × ts             | 1 × 6                   |
+| <b>ODTU4.ts</b>  | 95  | 160 | 1 to 80 | 15200 × ts             | 1 × 6                   |
+| <b>ODTU25.ts</b> | 952 | 16  | 1 to 20 | 15232 × ts             | 1 × 6                   |
+| <b>ODTU50.ts</b> | 476 | 32  | 1 to 40 | 15232 × ts             | 1 × 6                   |
+
+### 19.3 Multiplexing ODTU signals into the OPUk
+
+Multiplexing an ODTU01 signal into an OPU1 is realized by mapping the ODTU01 signal in one of the two OPU1 1.25G tributary slots.
+
+Multiplexing an ODTU12 signal into an OPU2 is realized by mapping the ODTU12 signal in one of the four OPU2 2.5G tributary slots or in two (of the eight) arbitrary OPU2 1.25G tributary slots: OPU2 TSa and TSb with  $1 \leq a < b \leq 8$ .
+
+Multiplexing an ODTU13 signal into an OPU3 is realized by mapping the ODTU13 signal in one of the sixteen OPU3 2.5G tributary slots or in two (of the thirty-two) arbitrary OPU3 1.25G tributary slots: OPU3 TSa and TSb with  $1 \leq a < b \leq 32$ .
+
+Multiplexing an ODTU23 signal into an OPU3 is realized by mapping the ODTU23 signal in four (of the sixteen) arbitrary OPU3 2.5G tributary slots: OPU3 TSa, TSb, TSc and TSd with  $1 \leq a < b < c < d \leq 16$  or in eight (of the thirty-two) arbitrary OPU3 1.25G tributary slots: OPU3 TSa, TSb, TSc, TSd, TSe, TSf, TSG and TSh with  $1 \leq a < b < c < d < e < f < g < h \leq 32$ .
+
+NOTE – a, b, c, d, e, f, g and h do not have to be sequential ( $a = i$ ,  $b = i+1$ ,  $c = i+2$ ,  $d = i+3$ ,  $e=i+4$ ,  $f=i+5$ ,  $g=i+6$ ,  $h=i+7$ ); the values can be arbitrarily selected to prevent bandwidth fragmentation.
+
+Multiplexing an ODTU2.ts signal into an OPU2 is realized by mapping the ODTU2.ts signal in ts (of the eight) arbitrary OPU2 1.25G tributary slots: OPU2 TSa, TSb, .. , TSp with  $1 \leq a < b < .. < p \leq 8$ .
+
+Multiplexing an ODTU3.ts signal into an OPU3 is realized by mapping the ODTU3.ts signal in ts (of the thirty-two) arbitrary OPU3 1.25G tributary slots: OPU3 TSa, TSb, .. , TSq with  $1 \leq a < b < \dots < q \leq 32$ .
+
+Multiplexing an ODTU4.ts signal into an OPU4 is realized by mapping the ODTU4.ts signal in ts (of the eighty) arbitrary OPU4 1.25G tributary slots: OPU4 TSa, TSb, .. , TSr with  $1 \leq a < b < \dots < r \leq 80$ .
+
+Multiplexing an ODTU25.ts signal into an OPU25 is realized by mapping the ODTU25.ts signal in ts (of the twenty) arbitrary OPU25 1.25G tributary slots: OPU25 TSa, TSb, .. , TSx with  $1 \leq a < b < \dots < x \leq 20$ .
+
+Multiplexing an ODTU50.ts signal into an OPU50 is realized by mapping the ODTU50.ts signal in ts (of the forty) arbitrary OPU50 1.25G tributary slots: OPU50 TSa, TSb, .. , TSx with  $1 \leq a < b < \dots < x \leq 40$ .
+
+The OPUk overhead for these multiplexed signals consists of a payload type (PT), the multiplex structure identifier (MSI), the OPU4 multiframe identifier ( $k=4$ ), the OPUk tributary slot overhead carrying the ODTU overhead and depending on the ODTU type one or more bytes reserved for future international standardization.
+
+### 19.3.1 ODTU12 mapping into one OPU2 tributary slot
+
+A byte of the ODTU12 payload signal is mapped into a byte of an OPU2 2.5G TS #i ( $i = 1, 2, 3, 4$ ) payload area, as indicated in Figure 19-9 (left). A byte of the ODTU12 overhead is mapped into a TSOH byte within column 16 of the OPU2 2.5G TS #i.
+
+A byte of the ODTU12 signal is mapped into a byte of one of two OPU2 1.25G TS #A,B ( $A, B = 1, 2, \dots, 8$ ) payload areas, as indicated in Figure 19-9 (right). A byte of the ODTU12 overhead is mapped into a TSOH byte within column 16 of the OPU2 1.25G TS #a,b.
+
+The remaining OPU2 TSOH bytes in column 15 are reserved for future international standardization.
+
+![Figure 19-9: Mapping of ODTU12 into one OPU2 2.5G tributary slot (left) and two OPU2 1.25G tributary slots (right).](e492fe1061d82aa76cbf7114f57eb90c_img.jpg)
+
+The diagram illustrates two methods for mapping an ODTU12 signal into OPU2 tributary slots.
+
+**Left Diagram: Mapping into one OPU2 2.5G tributary slot**
+
+- The ODTU12 signal is shown as a vertical stack of frames. Each frame has a header section (MFAS bits 78, 00, 11) and a payload section (columns 1-8, 952).
+- Vertical arrows indicate the mapping of ODTU12 frames into a single OPU2 2.5G TS #i frame.
+- The OPU2 2.5G TS #i frame has a header section (columns 1-4) and a payload section (columns 1-952).
+- Column 16 of the OPU2 2.5G TS #i frame is designated as the TSOH (Tributary Slot Overhead).
+
+**Right Diagram: Mapping into two OPU2 1.25G tributary slots**
+
+- The ODTU12 signal is shown as a vertical stack of frames. Each frame has a header section (MFAS bits 678, 000, 111) and a payload section (columns 1-8, 952).
+- Vertical arrows indicate the mapping of ODTU12 frames into two OPU2 1.25G TS #A and TS #B frames.
+- Each OPU2 1.25G TS frame has a header section (columns 1-4) and a payload section (columns 1-476).
+- Column 16 of each OPU2 1.25G TS frame is designated as the TSOH (Tributary Slot Overhead).
+
+G.709-Y.1331(20)\_F19-9
+
+Figure 19-9: Mapping of ODTU12 into one OPU2 2.5G tributary slot (left) and two OPU2 1.25G tributary slots (right).
+
+**Figure 19-9 – Mapping of ODTU12 into one OPU2 2.5G tributary slot (left) and two OPU2 1.25G tributary slots (right)**
+
+### 19.3.2 ODTU13 mapping into one OPU3 tributary slot
+
+A byte of the ODTU13 signal is mapped into a byte of an OPU3 2.5G TS #i (i = 1,2,...,16) payload area, as indicated in Figure 19-10 (left). A byte of the ODTU13 overhead is mapped into a TSOH byte within column 16 of the OPU3 2.5G TS #i.
+
+A byte of the ODTU13 signal is mapped into a byte of one of two OPU3 1.25G TS #A, B (A,B = 1,2,...,32) payload areas, as indicated in Figure 19-10 (right). A byte of the ODTU13 overhead is mapped into a TSOH byte within column 16 of the OPU3 1.25G TS #a,b.
+
+The remaining OPU3 TSOH bytes in column 15 are reserved for future international standardization.
+
+![Figure 19-10: Mapping of ODTU13 into one OPU3 2.5G tributary slot (left) and two OPU3 1.25G tributary slots (right).](3ce6b213ec556257e32ff7451182369d_img.jpg)
+
+The diagram illustrates two methods for mapping an ODTU13 signal into OPU3 tributary slots.
+
+**Left Diagram: Mapping into one OPU3 2.5G tributary slot (TS #i)**
+
+- The ODTU13 signal is shown as a vertical stack of frames. Each frame has a header (MFAS bits 5678, 0000) and a payload (1111).
+- The payload is mapped into the payload area of an OPU3 2.5G TS #i frame.
+- The OPU3 2.5G TS #i frame has a header (0000) and a payload (1111).
+- The payload area is divided into 238 columns. Column 16 is designated for the OPU3 TSOH of TS #i.
+- The mapping is shown for columns 1, 2, 3, 4, and 238.
+
+**Right Diagram: Mapping into two OPU3 1.25G tributary slots (TS #A and TS #B)**
+
+- The ODTU13 signal is shown as a vertical stack of frames. Each frame has a header (MFAS bits 45678, 00000) and a payload (11111).
+- The payload is split and mapped into the payload areas of two OPU3 1.25G TS #A and TS #B frames.
+- Each OPU3 1.25G TS frame has a header (00000) and a payload (11111).
+- The payload area is divided into 119 columns. Column 16 is designated for the OPU3 TSOH of TS #A, #B.
+- The mapping is shown for columns 1, 2, 3, 4, and 119.
+
+G.709-Y.1331(20)\_F19-10
+
+Figure 19-10: Mapping of ODTU13 into one OPU3 2.5G tributary slot (left) and two OPU3 1.25G tributary slots (right).
+
+**Figure 19-10 – Mapping of ODTU13 into one OPU3 2.5G tributary slot (left) and two OPU3 1.25G tributary slots (right)**
+
+### 19.3.3 ODTU23 mapping into four OPU3 tributary slots
+
+A byte of the ODTU23 signal is mapped into a byte of one of four OPU3 2.5G TS #A,B,C,D (A,B,C,D = 1,2,...,16) payload areas, as indicated in Figure 19-11 (top). A byte of the ODTU23 overhead is mapped into a TSOH byte within column 16 of the OPU3 TS #a,b,c,d.
+
+A byte of the ODTU23 signal is mapped into a byte of one of eight OPU3 1.25G TS #A, B, C, D, E, F, G, H (A,B,C,D,E,F,G,H = 1,2,...,32) payload areas, as indicated in Figure 19-11 (bottom). A byte of the ODTU23 overhead is mapped into a TSOH byte within column 16 of the OPU3 1.25G TS #a,b,c,d,e,f,g,h.
+
+The remaining OPU3 TSOH bytes in column 15 are reserved for future international standardization.
+
+![Figure 19-11: Mapping of ODTU23 into 4 OPU3 2.5G tributary slots (top) and 8 OPU3 1.25G tributary slots (bottom).](beda549cc2a4e2b9ac7f74fe9ed72b67_img.jpg)
+
+The diagram illustrates the mapping of ODTU23 data into OPU3 tributary slots. It is divided into two parts: the top part shows mapping into 4 OPU3 2.5G slots (#A, #B, #C, #D), and the bottom part shows mapping into 8 OPU3 1.25G slots (#A through #H).
+
+**Top Part: Mapping into 4 OPU3 2.5G Tributary Slots**
+
+- MFAS bits:** 5678 bits, with values 0000 and 1111 shown.
+- ODTU23:** The ODTU23 structure is shown on the left, with columns 16 and 17 highlighted.
+- ODTU23 Columns:** Columns 16 and 17 of the ODTU23 are mapped into the OPU3 tributary slots. Column 16 is mapped to the first column of each tributary slot, and column 17 is mapped to the last column.
+- OPU3 Tributary Slots:** There are 4 OPU3 2.5G tributary slots labeled #A, #B, #C, and #D. Each slot has 8 columns (1-8) and 4 rows (1-4). The first column (1) and last column (8) are used for TSOH. The data from ODTU23 columns 16 and 17 is mapped into the payload area of these slots.
+- Column 16 OPU3 TSOH:** Column 16 of the OPU3 TSOH of TS #a, b, c, d is shown.
+- Slot Indices:** The slots are indexed 1 2 3 4 5 6 7 8 at the top and 1 2 238 at the bottom.
+
+**Bottom Part: Mapping into 8 OPU3 1.25G Tributary Slots**
+
+- MFAS bits:** 45678 bits, with values 00000 and 11111 shown.
+- ODTU23:** The ODTU23 structure is shown on the left, with columns 16 and 17 highlighted.
+- ODTU23 Columns:** Columns 16 and 17 of the ODTU23 are mapped into the OPU3 tributary slots. Column 16 is mapped to the first column of each tributary slot, and column 17 is mapped to the last column.
+- OPU3 Tributary Slots:** There are 8 OPU3 1.25G tributary slots labeled #A, #B, #C, #D, #E, #F, #G, and #H. Each slot has 8 columns (1-8) and 4 rows (1-4). The first column (1) and last column (8) are used for TSOH. The data from ODTU23 columns 16 and 17 is mapped into the payload area of these slots.
+- Column 16 OPU3 TSOH:** Column 16 of the OPU3 TSOH of TS #a, b, c, d, e, f, g, h is shown.
+- Slot Indices:** The slots are indexed 1 2 3 4 5 6 7 8 at the top and 1 2 119 at the bottom.
+
+G.709-Y.1331(20)\_F19-11
+
+Figure 19-11: Mapping of ODTU23 into 4 OPU3 2.5G tributary slots (top) and 8 OPU3 1.25G tributary slots (bottom).
+
+**Figure 19-11 – Mapping of ODTU23 into 4 OPU3 2.5G tributary slots (#A, #B, #C, #D with A<B<C<D) (top) and 8 OPU3 1.25G tributary slots (#A, #B, #C, #D, #E, #F, #G, #H with A<B<C<D<E<F<G<H) (bottom)**
+
+### 19.3.4 ODTU01 mapping into one OPU1 1.25G tributary slot
+
+A byte of the ODTU01 signal is mapped into a byte of an OPU1 1.25G TS #i (i = 1,2), as indicated in Figure 19-12 for a group of 4 rows out of the ODTU01.
+
+A byte of the ODTU01 TSOH is mapped into a TSOH byte within column 16 of the OPU1 1.25G TS #i.
+
+The remaining OPU1 TSOH bytes in column 15 are reserved for future international standardization.
+
+![Diagram showing the mapping of ODTU01 into OPU1 1.25G tributary slot. It consists of two grid representations. The top grid represents the ODTU01 signal structure with 8 columns (1-8) and 1904 rows. The bottom grid represents the OPU1 1.25G tributary slot structure, also with 8 columns and 1904 rows. Arrows indicate the mapping of ODTU01 bytes into the OPU1 payload area. Labels on the left indicate MFAS bit 8, ODTU01, OPU1 TS #i, and OPU1 TSOH 4 of TS #i. A vertical label 'G.709-Y.1331(20)_F9-12' is on the right.](56f125e1bc127f7ac3d210407957413c_img.jpg)
+
+The diagram illustrates the mapping of ODTU01 into an OPU1 1.25G tributary slot. It features two main grid structures. The top grid represents the ODTU01 signal, with columns labeled 1 through 8 and rows numbered 1 to 1904. The bottom grid represents the OPU1 1.25G tributary slot, also with columns 1 through 8 and rows 1 to 1904. Arrows indicate the mapping of ODTU01 bytes into the OPU1 payload area. Labels on the left indicate MFAS bit 8, ODTU01, OPU1 TS #i, and OPU1 TSOH 4 of TS #i. A vertical label 'G.709-Y.1331(20)\_F9-12' is on the right.
+
+Diagram showing the mapping of ODTU01 into OPU1 1.25G tributary slot. It consists of two grid representations. The top grid represents the ODTU01 signal structure with 8 columns (1-8) and 1904 rows. The bottom grid represents the OPU1 1.25G tributary slot structure, also with 8 columns and 1904 rows. Arrows indicate the mapping of ODTU01 bytes into the OPU1 payload area. Labels on the left indicate MFAS bit 8, ODTU01, OPU1 TS #i, and OPU1 TSOH 4 of TS #i. A vertical label 'G.709-Y.1331(20)\_F9-12' is on the right.
+
+Figure 19-12 – Mapping of ODTU01 (excluding JOH) into OPU1 1.25G tributary slot
+
+### 19.3.5 ODTU2.ts mapping into ts OPU2 1.25G tributary slots
+
+A byte of the ODTU2.ts payload signal is mapped into a byte of an OPU2 1.25G TS #i (i = 1,...,ts) payload area, as indicated in Figure 19-13.
+
+A byte of the ODTU2.ts overhead is mapped into a TSOH byte within columns 15 and 16, rows 1 to 3 of the last OPU2 1.25G tributary slot allocated to the ODTU2.ts.
+
+The remaining OPU2 TSOH bytes are reserved for future international standardization.
+
+Image: Figure 19-13 – Mapping of ODTU2.ts into 'ts' OPU2 1.25G tributary slots
+
+**Figure 19-13 – Mapping of ODTU2.ts into 'ts' OPU2 1.25G tributary slots**
+
+The diagram shows the mapping process from an ODTU2.ts frame to multiple OPU2 tributary slots (TS #A, TS #B, ..., TS #X). 
+ The ODTU2.ts frame is a grid with columns 1 to 476 and rows 1 to r. It contains overhead bytes JC1, JC2, JC3, JC4, JC5, and JC6. 
+ Arrows indicate the mapping of payload bytes from ODTU2.ts into the payload areas of OPU2 TS #A, OPU2 TS #B, and OPU2 TS #X. 
+ Each OPU2 TS frame has 4 rows and 476 columns. 
+ On the left, a vertical structure shows the OPU2 tributary slots indexed by MFAS bits (678) from 000 to 111. 
+ It highlights the OPU2 TSOH (Tributary Slot Overhead) area, which includes RES (reserved) bytes and the JC overhead bytes mapped from the ODTU2.ts.
+
+### 19.3.6 ODTU3.ts mapping into *ts* OPU3 1.25G tributary slots
+
+A byte of the ODTU3.ts payload signal is mapped into a byte of an OPU3 1.25G TS #*i* (*i* = 1,...,*ts*) payload area, as indicated in Figure 19-14.
+
+A byte of the ODTU3.ts overhead is mapped into a TSOH byte within columns 15 and 16, rows 1 to 3 of the last OPU3 1.25G tributary slot allocated to the ODTU3.ts.
+
+The remaining OPU3 TSOH bytes are reserved for future international standardization.
+
+136 Rec. ITU-T G.709/Y.1331 (06/2020)
+
+![Diagram showing the mapping of ODTU3.ts into 'ts' OPU3 1.25G tributary slots. The top part shows the ODTU3.ts frame structure with columns 1, 2, 3, ..., ts, 119 and rows 1, 2, 3, 4, ..., r-3, r-2, r-1, r. Columns 15 and 16 are labeled JC6, JC5, JC4, JC3, JC2, JC1. The bottom part shows the mapping into OPU3 tributary slots, with slots labeled OPU3 TS #A, OPU3 TS #B, ..., OPU3 TS #X. Each slot has columns 1, 2, ..., 119 and rows 1, 2, 3, 4. The mapping is shown by dashed lines from the ODTU3.ts frame to the OPU3 slots. On the left, a legend shows the OPU3 TSOH structure with MFAS bits (45678), 00000, and RES RES RES RES for TS #A and TS #B. The OPU3 TSOH of TS #a, b, ..., x is also shown with columns 1, 2, ..., 119 and rows 1, 2, 3, 4. The diagram is labeled G.709-Y.1331(20)_F19-14.](d6b0963170ed3d0ed9c5bfaccec452e3_img.jpg)
+
+Diagram showing the mapping of ODTU3.ts into 'ts' OPU3 1.25G tributary slots. The top part shows the ODTU3.ts frame structure with columns 1, 2, 3, ..., ts, 119 and rows 1, 2, 3, 4, ..., r-3, r-2, r-1, r. Columns 15 and 16 are labeled JC6, JC5, JC4, JC3, JC2, JC1. The bottom part shows the mapping into OPU3 tributary slots, with slots labeled OPU3 TS #A, OPU3 TS #B, ..., OPU3 TS #X. Each slot has columns 1, 2, ..., 119 and rows 1, 2, 3, 4. The mapping is shown by dashed lines from the ODTU3.ts frame to the OPU3 slots. On the left, a legend shows the OPU3 TSOH structure with MFAS bits (45678), 00000, and RES RES RES RES for TS #A and TS #B. The OPU3 TSOH of TS #a, b, ..., x is also shown with columns 1, 2, ..., 119 and rows 1, 2, 3, 4. The diagram is labeled G.709-Y.1331(20)\_F19-14.
+
+Figure 19-14 – Mapping of ODTU3.ts into 'ts' OPU3 1.25G tributary slots
+
+### 19.3.7 ODTU4.ts mapping into ts OPU4 1.25G tributary slots
+
+A byte of the ODTU4.ts payload signal is mapped into a byte of an OPU4 1.25G TS #i (i = 1,...,ts) payload area, as indicated in Figure 19-15.
+
+A byte of the ODTU4.ts overhead is mapped into a TSOH byte within columns 15 and 16, rows 1 to 3 of the last OPU4 1.25G tributary slot allocated to the ODTU4.ts.
+
+The remaining OPU4 TSOH bytes are reserved for future international standardization.
+
+![Diagram showing the mapping of ODTU4.ts into 'ts' OPU4 1.25G tributary slots. The diagram illustrates the structure of an ODTU4.ts frame, the mapping of tributary slots (TS #A, TS #B, TS #X) into OPU4 tributary slots, and the resulting OPU4 TSOH structure.](c93353297f7ed04bc9173ac1f224d406_img.jpg)
+
+The diagram illustrates the mapping of ODTU4.ts into 'ts' OPU4 1.25G tributary slots. At the top, the **ODTU4.ts** frame is shown with columns labeled 1, 2, 3, ..., *ts*, ..., 95. The rows are grouped as (1,2), (3,4) and continue down to (157, 158), (159, 160). On the left side of the ODTU4.ts frame, overhead bytes are labeled: JC6, JC4, JC3, JC1, JC5, and JC2.
+
+Below this, the mapping to **OPU4 TS #A**, **OPU4 TS #B**, and **OPU4 TS #X** is shown. Each tributary slot (TS) is represented by a grid with rows 1, 2, 3, 4 and columns 1, 2, ..., 47/48, 48/49, ..., 95. Dashed lines indicate the mapping from the ODTU4.ts columns into these slots.
+
+On the far left, the **OMFI bits** (2345678) and **OPU4 tributary slots** are shown. For OMFI 0000000, **TS #A** has overhead bytes RES, RES, RES, RES. For OMFI 1001111, **TS #X** has overhead bytes JC6, JC4, JC3, JC1, JC5, JC2. This section is labeled **OPU4 TSOH of TS #a, b, ..., x**.
+
+G.709-Y.1331(20)\_F19-15
+
+Diagram showing the mapping of ODTU4.ts into 'ts' OPU4 1.25G tributary slots. The diagram illustrates the structure of an ODTU4.ts frame, the mapping of tributary slots (TS #A, TS #B, TS #X) into OPU4 tributary slots, and the resulting OPU4 TSOH structure.
+
+**Figure 19-15 – Mapping of ODTU4.ts into 'ts' OPU4 1.25G tributary slots**
+
+### 19.3.8 ODTU25.ts mapping into ts OPU25 1.25G tributary slots
+
+A byte of the ODTU25.ts payload signal is mapped into a byte of an OPU25 1.25G TS #i (i = 1,...,ts) payload area, as indicated in Figure 19-16.
+
+A byte of the ODTU25.ts overhead is mapped into a TSOH byte within columns 15 and 16, rows 1 to 3 of the last OPU25 1.25G tributary slot allocated to the ODTU25.ts.
+
+The remaining OPU25 TSOH bytes are reserved for future international standardization.
+
+![Diagram illustrating the mapping of ODTU25.ts into 'ts' OPU25 1.25G tributary slots. The diagram shows the ODTU25.ts structure with MFAS bits (45678), overhead (00000), and payload (10011) being mapped into multiple OPU25 tributary slots (TS #A, TS #B, ..., TS #X). Each slot has a payload area and a TSOH area (columns 15 and 16, rows 1-3). The mapping is shown for the first few slots and then generalized for slot X.](48090d8f1db2e826aaa740035aa12ecb_img.jpg)
+
+The diagram illustrates the mapping of an ODTU25.ts signal into multiple OPU25 1.25G tributary slots (TS #A, TS #B, ..., TS #X). The ODTU25.ts structure is shown on the left, with MFAS bits (45678), overhead (00000), and payload (10011) being mapped into the payload area of the OPU25 slots. The TSOH (Tributary Slot Overhead) is shown in columns 15 and 16, rows 1 to 3 of the last slot (TS #X). The mapping is shown for the first few slots and then generalized for slot X. The diagram includes labels for columns (1, 2, 3, ..., 952) and rows (1, 2, 3, 4, ..., r-3, r-2, r-1, r) for the overall ODTU25.ts structure, and columns (1, 2, ..., 952) and rows (1, 2, 3, 4, ..., 13, 14, 15, 16) for individual OPU25 slots. The OPU25 TSOH of TS #A, B, ..., X is also indicated.
+
+Diagram illustrating the mapping of ODTU25.ts into 'ts' OPU25 1.25G tributary slots. The diagram shows the ODTU25.ts structure with MFAS bits (45678), overhead (00000), and payload (10011) being mapped into multiple OPU25 tributary slots (TS #A, TS #B, ..., TS #X). Each slot has a payload area and a TSOH area (columns 15 and 16, rows 1-3). The mapping is shown for the first few slots and then generalized for slot X.
+
+Figure 19-16 – Mapping of ODTU25.ts into 'ts' OPU25 1.25G tributary slots
+
+### 19.3.9 ODTU50.ts mapping into ts OPU50 1.25G tributary slots
+
+A byte of the ODTU50.ts payload signal is mapped into a byte of an OPU50 1.25G TS #i (i = 1,...,ts) payload area, as indicated in Figure 19-17.
+
+A byte of the ODTU50.ts overhead is mapped into a TSOH byte within columns 15 and 16, rows 1 to 3 of the last OPU50 1.25G tributary slot allocated to the ODTU50.ts.
+
+The remaining OPU50 TSOH bytes are reserved for future international standardization.
+
+![Diagram showing the mapping of ODTU50.ts into 'ts' OPU50 1.25G tributary slots. The top part shows the ODTU50.ts frame structure with 476 x ts columns and rows 1 to r. The bottom part shows the mapping into OPU50 tributary slots (TS #A, TS #B, ..., TS #X). Each TS contains 32 rows. Rows 1-4 are payload, rows 5-28 are reserved (RES), and rows 29-32 are OPU50 TSOH. Justification control (JC) and opportunity (NJO) signals are shown in the TSOH area. The mapping is indicated by dashed lines from the ODTU50.ts frame to the OPU50 TS frames. The diagram includes bit counts (MFAS bits 345678, 000000, 100111) and slot labels (OPU50 tributary slots).](1594605eb94cd26a95fcfdb0b8af86ca_img.jpg)
+
+The diagram illustrates the mapping of an ODTU50.ts frame into multiple OPU50 1.25G tributary slots (TS). The ODTU50.ts frame is shown at the top with columns labeled 1, 2, 3, ..., ts, ..., 476 x ts. Rows are numbered 1, 2, 3, 4, ..., r-3, r-2, r-1, r. Below this, the mapping into OPU50 TS #A, OPU50 TS #B, ..., OPU50 TS #X is shown. Each TS frame has 32 rows. Rows 1, 2, 3, and 4 are payload. Rows 5 through 28 are reserved (RES). Rows 29, 30, 31, and 32 are the OPU50 TSOH. The TSOH contains justification control (JC) and opportunity (NJO) signals. The mapping is indicated by dashed lines from the ODTU50.ts frame to the OPU50 TS frames. The diagram also includes bit counts: MFAS bits (345678, 000000, 100111) and slot labels (OPU50 tributary slots).
+
+Diagram showing the mapping of ODTU50.ts into 'ts' OPU50 1.25G tributary slots. The top part shows the ODTU50.ts frame structure with 476 x ts columns and rows 1 to r. The bottom part shows the mapping into OPU50 tributary slots (TS #A, TS #B, ..., TS #X). Each TS contains 32 rows. Rows 1-4 are payload, rows 5-28 are reserved (RES), and rows 29-32 are OPU50 TSOH. Justification control (JC) and opportunity (NJO) signals are shown in the TSOH area. The mapping is indicated by dashed lines from the ODTU50.ts frame to the OPU50 TS frames. The diagram includes bit counts (MFAS bits 345678, 000000, 100111) and slot labels (OPU50 tributary slots).
+
+Figure 19-17 – Mapping of ODTU50.ts into 'ts' OPU50 1.25G tributary slots
+
+#### 19.4 OPUk multiplex overhead and ODTU justification overhead
+
+The OPUk (k=1,2,3,4,25,50) multiplex overhead consists of a multiplex structure identifier (MSI) and an ODTU overhead. The OPUk (k=4,25,50) multiplex overhead contains an OPU multiframe identifier (OMFI).
+
+The OPUk MSI overhead locations are shown in Figures 19-18A, 19-18B and 19-18C and the OMFI overhead location is shown in Figure 19-18C.
+
+#### ODTUjk overhead
+
+The ODTUjk overhead carries the AMP justification overhead consisting of justification control (JC) and negative justification opportunity (NJO) signals in column 16 of rows 1 to 4. ODTUjk overhead bytes in column 15 rows 1, 2 and 3 are reserved for future international standardization.
+
+The ODTUjk overhead consists of 3 bytes of justification control (JC) and 1 byte of negative justification opportunity (NJO) overhead. The JC and NJO overhead locations are shown in Figures 19-18A and 19-18B. In addition, two or n times two positive justification overhead bytes (PJO1, PJO2) are located in the ODTUjk payload area. Note that the PJO1 and PJO2 locations are multiframe, ODUj and OPUk tributary slot dependent.
+
+The PJO1 for an ODU1 in OPU2 or OPU3 2.5G tributary slot #i (i: 1..4 or 1..16 respectively) is located in the first column of OPUk 2.5G tributary slot #i (OPUk column 16+i) and the PJO2 is
+
+located in the second column of OPUk 2.5G tributary slot #i (OPU2 column 20+i, OPU3 column 32+i) in frame #i of the four or sixteen frame multiframe.
+
+EXAMPLE – ODU1 in OPU2 or OPU3 TS(1): PJO1 in column 16+1=17, PJO2 in column 20+1=21 (OPU2) and 32+1=33 (OPU3). ODU1 in OPU2 TS(4): PJO1 in column 16+4=20, PJO2 in column 20+4=24. ODU1 in OPU3 TS(16): PJO1 in column 16+16=32, PJO2 in column 32+16=48.
+
+The four PJO1s for an ODU2 in OPU3 2.5G tributary slots #a, #b, #c and #d are located in the first column of OPU3 2.5G tributary slot #a (OPU3 column 16+a) in frames #a, #b, #c and #d of the sixteen frame multiframe. The four PJO2s for an ODU2 in OPU3 2.5G tributary slots #a, #b, #c and #d are located in the first column of OPU3 2.5G tributary slot #b (OPU3 column 16+b) in frames #a, #b, #c and #d of the sixteen frame multiframe. Figure 19-18A presents an example with four ODU2s in the OPU3 mapped into 2.5G tributary slots (1,5,9,10), (2,3,11,12), (4,14,15,16) and (6,7,8,13).
+
+EXAMPLE – ODU2 in OPU3 TS(1,2,3,4): PJO1 in column 16+1=17, PJO2 in column 16+2=18. ODU2 in OPU3 TS(13,14,15,16): PJO1 in column 16+13=29, PJO2 in column 16+14=30.
+
+The PJO1 for an ODU0 in OPU1 1.25G tributary slot #i (i: 1,2) is located in the first column of OPU1 1.25G tributary slot #i (OPU1 column 16+i) and the PJO2 is located in the second column of OPU1 1.25G tributary slot #i (OPU1 column 18+i) in frame #i of the two frame multiframe.
+
+The PJO1 for an ODU1 in OPU2 or OPU3 1.25G tributary slots #a and #b (a: 1..7 or 1..31 respectively; b: 2..8 or 2..32 respectively) is located in the first column of OPUk 1.25G tributary slot #a (OPUk column 16+a) and the PJO2 is located in the first column of OPUk 1.25G tributary slot #b (OPUk column 16+b) in frames #a and #b of the eight or thirty-two frame multiframe.
+
+EXAMPLE – ODU1 in OPU2 or OPU3 TS(1,2): PJO1 in column 16+1=17, PJO2 in column 16+2=18. ODU1 in OPU2 TS(7,8): PJO1 in column 16+7=23, PJO2 in column 16+8=24. ODU1 in OPU3 TS(31,32): PJO1 in column 16+31=47, PJO2 in column 16+32=48.
+
+The eight PJO1s for an ODU2 in OPU3 1.25G tributary slots #a, #b, #c, #d, #e, #f, #g and #h are located in the first column of OPU3 1.25G tributary slot #a (OPU3 column 16+a) in frames #a, #b, #c, #d, #e, #f, #g and #h of the thirty-two frame multiframe. The eight PJO2s for an ODU2 in OPU3 1.25G tributary slots #a, #b, #c, #d, #e, #f, #g and #h are located in the first column of OPU3 1.25G tributary slot #b (OPU3 column 16+b) in frames #a, #b, #c, #d, #e, #f, #g and #h of the thirty-two frame multiframe. Figure 19-18B presents an example with two ODU2s and two ODU1s in the OPU3 mapped into 1.25G tributary slots (1,5,9,10,17,19,20,21), (25,26,27,28,29,30,31,32), (2,3) and (4,24).
+
+EXAMPLE – ODU2 in OPU3 TS(1,2,3,4,5,6,7,8): PJO1 in column 16+1=17, PJO2 in column 16+2=18. ODU2 in OPU3 TS(25,26,27,28,29,30,31,32): PJO1 in column 16+25=41, PJO2 in column 16+26=42.
+
+![Diagram showing OPUk multiplex overhead for k=1, 2, 3. It includes a main frame structure at the top, followed by detailed overhead maps for OPU1, OPU2, and OPU3. Each map shows the placement of PJO1, PJO2, and PJO3 signals within the overhead bits. Dashed lines connect the main frame to the specific overhead details.](28e47e64ac18ca4d8924dab65cedc2d8_img.jpg)
+
+**Main Frame Structure:**
+
+| Row | Column 15 | Column 16 | Column 17                     | ... | 3821 | 3822 | 3823 | 3824 |  |
+|-----|-----------|-----------|-------------------------------|-----|------|------|------|------|--|
+| 1   | RES       | JC        | OPUk payload (4 × 3808 bytes) |     |      |      |      |      |  |
+| 2   | RES       | JC        |                               |     |      |      |      |      |  |
+| 3   | RES       | JC        |                               |     |      |      |      |      |  |
+| 4   | PSI       | NJO       | PJO                           |     |      |      |      |      |  |
+
+**OPU1 (1.25G TS) with ODU0:**
+
+| Row | Column 15 | Column 16 | Column 17 | Column 18 | Column 19 | Column 20 |
+|-----|-----------|-----------|-----------|-----------|-----------|-----------|
+| 0   | PT = 20   |           |           |           |           |           |
+| 1   | Reserved  |           |           |           |           |           |
+| 2   | MSI       |           |           |           |           |           |
+| 3   |           |           |           |           |           |           |
+| 4   |           |           |           |           |           |           |
+| 255 | Reserved  |           |           |           |           |           |
+
+**OPU2 (2.5G TS) with ODU1:**
+
+| Row  | Column 17 | Column 18 | Column 19 | Column 20 | Column 21 | Column 22 | Column 23 | Column 24 |
+|------|-----------|-----------|-----------|-----------|-----------|-----------|-----------|-----------|
+| 00   | PJO1      |           |           |           |           |           |           |           |
+| 01   |           | PJO1      |           |           |           |           |           |           |
+| 10   |           |           | PJO1      |           |           |           |           |           |
+| 11   |           |           |           | PJO1      |           |           |           |           |
+| ...  |           |           |           |           |           |           |           |           |
+| 0000 | PJO1      |           |           |           |           |           |           |           |
+| 0001 |           | PJO1      |           |           |           |           |           |           |
+| 0010 |           |           | PJO1      |           |           |           |           |           |
+| 0011 |           |           |           | PJO1      |           |           |           |           |
+| ...  |           |           |           |           |           |           |           |           |
+| 1111 |           |           |           |           |           |           |           |           |
+
+**OPU3 (2.5G TS) with ODU1:**
+
+| Row  | Column 17 | Column 18 | Column 19 | Column 20 | Column 21 | Column 22 | Column 23 | Column 24 | Column 32 | Column 33 | Column 34 | Column 35 | Column 48 |
+|------|-----------|-----------|-----------|-----------|-----------|-----------|-----------|-----------|-----------|-----------|-----------|-----------|-----------|
+| 0000 | PJO1      |           |           |           |           |           |           |           |           |           |           |           |           |
+| 0001 |           | PJO1      |           |           |           |           |           |           |           |           |           |           |           |
+| 0010 |           |           | PJO1      |           |           |           |           |           |           |           |           |           |           |
+| 0011 |           |           |           | PJO1      |           |           |           |           |           |           |           |           |           |
+| ...  |           |           |           |           |           |           |           |           |           |           |           |           |           |
+| 1111 |           |           |           |           |           |           |           |           |           |           |           |           |           |
+
+**OPU3 (2.5G TS) with ODU2 (1, 5, 9, 10), (2, 3, 11, 12), (4, 14, 15, 16), (6, 7, 8, 13):**
+
+| Row  | Column 17 | Column 18 | Column 19 | Column 20 | Column 21 | Column 22 | Column 23 | Column 24 | Column 25 | Column 26 | Column 27 | Column 28 | Column 29 | Column 30 | Column 31 | Column 32 |
+|------|-----------|-----------|-----------|-----------|-----------|-----------|-----------|-----------|-----------|-----------|-----------|-----------|-----------|-----------|-----------|-----------|
+| 0000 | PJO1      |           |           |           |           |           |           |           |           |           |           |           |           |           |           |           |
+| 0001 |           | PJO1      |           |           |           |           |           |           |           |           |           |           |           |           |           |           |
+| 0010 |           |           | PJO1      |           |           |           |           |           |           |           |           |           |           |           |           |           |
+| 0011 |           |           |           | PJO1      |           |           |           |           |           |           |           |           |           |           |           |           |
+| 0100 | PJO1      |           |           |           |           |           |           |           |           |           |           |           |           |           |           |           |
+| 0101 |           |           |           |           |           |           |           |           |           |           |           |           |           |           |           |           |
+| 0110 |           |           |           |           |           |           |           |           |           |           |           |           |           |           |           |           |
+| 0111 |           |           |           |           |           |           |           |           |           |           |           |           |           |           |           |           |
+| 1000 | PJO1      |           |           |           |           |           |           |           |           |           |           |           |           |           |           |           |
+| 1001 |           |           |           |           |           |           |           |           |           |           |           |           |           |           |           |           |
+| 1010 |           | PJO1      |           |           |           |           |           |           |           |           |           |           |           |           |           |           |
+| 1011 |           |           | PJO1      |           |           |           |           |           |           |           |           |           |           |           |           |           |
+| 1100 |           |           |           |           |           |           |           |           |           |           |           |           |           |           |           |           |
+| 1101 |           |           |           |           |           |           |           |           |           |           |           |           |           |           |           |           |
+| 1110 |           |           |           |           |           |           |           |           |           |           |           |           |           |           |           |           |
+| 1111 |           |           |           |           |           |           |           |           |           |           |           |           |           |           |           |           |
+
+Diagram showing OPUk multiplex overhead for k=1, 2, 3. It includes a main frame structure at the top, followed by detailed overhead maps for OPU1, OPU2, and OPU3. Each map shows the placement of PJO1, PJO2, and PJO3 signals within the overhead bits. Dashed lines connect the main frame to the specific overhead details.
+
+G.709-Y.1331(20)\_F19-18A
+
+Figure 19-18A – OPUk (k=1,2,3) multiplex overhead associated with an ODUjk only (payload type = 20)
+
+| Row | Column |     |     |  | 3821 3822 3823 3824              |  |  |  |
+|-----|--------|-----|-----|--|----------------------------------|--|--|--|
+|     | 15     | 16  | 17  |  |                                  |  |  |  |
+| 1   | RES    | JC  |     |  | OPUk payload<br>(4 × 3808 bytes) |  |  |  |
+| 2   | RES    | JC  |     |  |                                  |  |  |  |
+| 3   | RES    | JC  |     |  |                                  |  |  |  |
+| 4   | PSI    | NJO | PJO |  |                                  |  |  |  |
+
+|    |          |   |   |   |   |   |    |
+|----|----------|---|---|---|---|---|----|
+| 1  | 2        | 3 | 4 | 5 | 6 | 7 | 8  |
+| JC | Reserved |   |   |   |   |   | JC |
+
+| OPU2 |          |
+|------|----------|
+| 0    | PT = 21  |
+| 1    | Reserved |
+| 2    | MSI      |
+| 9    |          |
+| 10   |          |
+| 255  | Reserved |
+
+| OPU3 |          |
+|------|----------|
+| 0    | PT = 21  |
+| 1    | Reserved |
+| 2    | MSI      |
+| 33   |          |
+| 34   |          |
+| 255  | Reserved |
+
+OPU2 (1.25G TS) with ODU1 (1, 2), (3, 6), (7, 8)
+
+| MFAS bits 678 | Column |      |      |    |    |      |    |    | MFAS bits 678 | Column |    |      |    |    |      |      |      |
+|---------------|--------|------|------|----|----|------|----|----|---------------|--------|----|------|----|----|------|------|------|
+|               | 17     | 18   | 19   | 20 | 21 | 22   | 23 | 24 |               | 17     | 18 | 19   | 20 | 21 | 22   | 23   | 24   |
+| 000           | PJO1   | PJO2 |      |    |    |      |    |    | 100           |        |    |      |    |    |      |      |      |
+| 001           | PJO1   | PJO2 |      |    |    |      |    |    | 101           |        |    | PJO1 |    |    | PJO2 |      |      |
+| 010           |        |      | PJO1 |    |    | PJÓ2 |    |    | 110           |        |    |      |    |    |      | PJO1 | PJO2 |
+| 011           |        |      |      |    |    |      |    |    | 111           |        |    |      |    |    |      | PJO1 | PJO2 |
+
+OPU3 (1.25G TS) with ODU2 (1, 5, 9, 10, 17, 19, 20, 21), (25, 26, 27, 28, 29, 30, 31, 32), ODU1 (2, 3), (4, 24)
+
+Image: Diagram showing OPU3 multiplex overhead mapping for various ODU configurations. It details the placement of PJO1 and PJO2 bytes across columns 17 to 48 based on MFAS bits 45678. The table is split into two main sections for MFAS bits 00000-01111 and 10000-11111. Specific cells are highlighted with PJO1 (yellow/orange) and PJO2 (yellow/orange/brown) labels, showing a structured pattern of overhead distribution.
+
+**Figure 19-18B – OPUk (k=2,3) multiplex overhead associated with an ODTUjk only (payload type = 21)**
+
+Rec. ITU-T G.709/Y.1331 (06/2020) 143
+
+## ODTuk.ts overhead
+
+The ODTUk.ts overhead carries the GMP justification overhead consisting of 3 bytes of justification control (JC1, JC2, JC3) which carry the 14-bit GMP  $C_m$  information and client/ODU specific 3 bytes of justification control (JC4, JC5, JC6) which carry the 10-bit GMP  $\Sigma C_{8D}$  information.
+
+The JC1, JC2, JC3, JC4, JC5 and JC6 overhead locations are shown in Figure 19-18C.
+
+![Figure 19-18C: OPUk (k=2,3,4,25,50) multiplex overhead associated with an ODTUk.ts (payload type = 21).](6059b0a3a051cc20b414d51a4e412f3e_img.jpg)
+
+The diagram illustrates the OPUk multiplex overhead structure for payload type 21. At the top, a grid shows the OPUk payload (4 × 3808 bytes) across columns 15 to 3824. Below this, the overhead structure is detailed for OPU2, OPU3, and OPU4.
+
+**OPU2 Structure:**
+
+|     |          |  |
+|-----|----------|--|
+| 0   | PT = 21  |  |
+| 1   | Reserved |  |
+| 2   | MSI      |  |
+| 9   |          |  |
+| 10  | Reserved |  |
+| 255 |          |  |
+
+**OPU3 Structure:**
+
+|     |          |  |
+|-----|----------|--|
+| 0   | PT = 21  |  |
+| 1   | Reserved |  |
+| 2   | MSI      |  |
+| 33  |          |  |
+| 34  | Reserved |  |
+| 255 |          |  |
+
+**OPU4 Structure:**
+
+|     |          |          |  |
+|-----|----------|----------|--|
+| 0   | PT = 21  |          |  |
+| 1   | Reserved |          |  |
+| 2   | MSI      |          |  |
+| 81  |          |          |  |
+| 82  |          | Reserved |  |
+| 255 |          |          |  |
+
+**Justification Control Details:**
+
+- ODTU2.ts / ODTU3.ts:** JC4, JC1; JC5, JC2; JC6, JC3; RES. OMFI: 0 MSB ... LSB.
+- ODTU4.ts:** JC4, JC1; JC5, JC2; JC6, JC3; OMFI.
+- JC1, JC2, JC3:** 14-bit  $C_m$  (m=8 × M). JC1: C1-C8; JC2: C9-C14, II, DI; JC3: CRC-8. Decrement and Increment indicators are shown.
+- JC4, JC5, JC6:** Client specific 10-bit  $\Sigma C_{8D}$ . JC4: RES, RES, RES, D1-D5; JC5: RES, RES, RES, D6-D10; JC6: RES, RES, RES, CRC-5.
+
+Figure 19-18C: OPUk (k=2,3,4,25,50) multiplex overhead associated with an ODTUk.ts (payload type = 21).
+
+Figure 19-18C – OPUk (k=2,3,4,25,50) multiplex overhead associated with an ODTUk.ts (payload type = 21)
+
+### 19.4.1 OPUk multiplex structure identifier (MSI)
+
+The OPUk (k=1,2,3,4,25,50) multiplex structure identifier (MSI) overhead, which encodes the ODU multiplex structure in the OPU, is located in the mapping specific area of the PSI signal (refer to Figure 19-18A for the MSI location in OPUk with PT=20, refer to Figures 19-18B and 19-18C for the MSI location in OPUk with PT=21). The MSI has an OPU and tributary slot (2.5G, 1.25G) specific length (OPU1: 2 bytes, OPU2: 4 or 8 bytes, OPU3: 16 or 32 bytes, OPU4: 80 bytes, OPU25: 20 bytes, OPU50: 40 bytes) and indicates the ODTU content of each tributary slot (TS) of an OPU. One byte is used for each TS.
+
+#### 19.4.1.1 OPU2 multiplex structure identifier (MSI) – Payload type 20
+
+For the 4 OPU2 2.5G tributary slots four bytes of the PSI are used (PSI[2] .. PSI[5]) as MSI bytes as shown in Figures 19-18A and 19-19. The MSI indicates the ODTU content of each tributary slot of the OPU2. One byte is used for each tributary slot.
+
+- The ODTU type in bits 1 and 2 is fixed to 00 to indicate the presence of an ODTU12.
+- The tributary port # indicates the port number of the ODU1 that is being transported in this 2.5G TS; the assignment of ports to tributary slots is fixed, the port number equals the tributary slot number.
+
+|               | 1  | 2 | 3 | 4 | 5  | 6    | 7 | 8 |            |
+|---------------|----|---|---|---|----|------|---|---|------------|
+| <i>PSI[2]</i> | 00 |   |   |   | 00 | 0000 |   |   | <i>TS1</i> |
+| <i>PSI[3]</i> | 00 |   |   |   | 00 | 0001 |   |   | <i>TS2</i> |
+| <i>PSI[4]</i> | 00 |   |   |   | 00 | 0010 |   |   | <i>TS3</i> |
+| <i>PSI[5]</i> | 00 |   |   |   | 00 | 0011 |   |   | <i>TS4</i> |
+
+Figure 19-19 – OPU2-MSI coding – Payload type 20
+
+#### 19.4.1.2 OPU3 multiplex structure identifier (MSI) – Payload type 20
+
+For the 16 OPU3 2.5G tributary slots 16 bytes of the PSI are used (PSI[2] .. PSI[17]) as MSI bytes as shown in Figures 19-18A, 19-20A and 19-20B. The MSI indicates the ODTU content of each tributary slot of the OPU3. One byte is used for each tributary slot.
+
+- The ODTU type in bits 1 and 2 indicates if the OPU3 TS is carrying ODTU13 or ODTU23. The default ODTU type is ODTU13; it is present when either a tributary slot carries an ODTU13, or is not allocated to carry an ODTU. Refer to Appendix V for some examples.
+- The tributary port # in bits 3 to 8 indicates the port number of the ODTU13/23 that is being transported in this 2.5G TS; for the case of ODTU23, a flexible assignment of tributary ports to tributary slots is possible, for the case of ODTU13, this assignment is fixed, the tributary port number equals the tributary slot number. ODTU23 tributary ports are numbered 1 to 4.
+
+|                | 1         | 2 | 3                | 4 | 5 | 6 | 7 | 8 |  |             |
+|----------------|-----------|---|------------------|---|---|---|---|---|--|-------------|
+| <i>PSI[2]</i>  | ODTU type |   | Tributary Port # |   |   |   |   |   |  | <i>TS1</i>  |
+| <i>PSI[3]</i>  | ODTU type |   | Tributary Port # |   |   |   |   |   |  | <i>TS2</i>  |
+| <i>PSI[4]</i>  | ODTU type |   | Tributary Port # |   |   |   |   |   |  | <i>TS3</i>  |
+| <i>PSI[5]</i>  | ODTU type |   | Tributary Port # |   |   |   |   |   |  | <i>TS4</i>  |
+| <i>PSI[6]</i>  | ODTU type |   | Tributary Port # |   |   |   |   |   |  | <i>TS5</i>  |
+| <i>PSI[7]</i>  | ODTU type |   | Tributary Port # |   |   |   |   |   |  | <i>TS6</i>  |
+| <i>PSI[8]</i>  | ODTU type |   | Tributary Port # |   |   |   |   |   |  | <i>TS7</i>  |
+| <i>PSI[9]</i>  | ODTU type |   | Tributary Port # |   |   |   |   |   |  | <i>TS8</i>  |
+| <i>PSI[10]</i> | ODTU type |   | Tributary Port # |   |   |   |   |   |  | <i>TS9</i>  |
+| <i>PSI[11]</i> | ODTU type |   | Tributary Port # |   |   |   |   |   |  | <i>TS10</i> |
+| <i>PSI[12]</i> | ODTU type |   | Tributary Port # |   |   |   |   |   |  | <i>TS11</i> |
+| <i>PSI[13]</i> | ODTU type |   | Tributary Port # |   |   |   |   |   |  | <i>TS12</i> |
+| <i>PSI[14]</i> | ODTU type |   | Tributary Port # |   |   |   |   |   |  | <i>TS13</i> |
+| <i>PSI[15]</i> | ODTU type |   | Tributary Port # |   |   |   |   |   |  | <i>TS14</i> |
+| <i>PSI[16]</i> | ODTU type |   | Tributary Port # |   |   |   |   |   |  | <i>TS15</i> |
+
+![](3eb2af31c2e61e2595c8440d726f5d4e_img.jpg)
+
+|                |           |                  |             |
+|----------------|-----------|------------------|-------------|
+| <i>PSI[17]</i> | ODTU type | Tributary Port # | <i>TS16</i> |
+|                |           |                  |             |
+
+**Figure 19-20A – OPU3-MSI coding – Payload type 20**
+
+![](60f844d947ea0bccdd9f64d81d5f8d26_img.jpg)
+
+|                 |                                                                                                                                                                                                                                                                                                                                                                                                  |   |                  |   |   |   |   |   |              |            |                           |            |                           |              |                           |              |                           |  |   |  |                            |
+|-----------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---|------------------|---|---|---|---|---|--------------|------------|---------------------------|------------|---------------------------|--------------|---------------------------|--------------|---------------------------|--|---|--|----------------------------|
+| <i>PSI[1+i]</i> | 1                                                                                                                                                                                                                                                                                                                                                                                                | 2 | 3                | 4 | 5 | 6 | 7 | 8 | <i>TS #i</i> |            |                           |            |                           |              |                           |              |                           |  |   |  |                            |
+|                 | ODTU type                                                                                                                                                                                                                                                                                                                                                                                        |   | Tributary Port # |   |   |   |   |   |              |            |                           |            |                           |              |                           |              |                           |  |   |  |                            |
+|                 | <table border="0"> <tr> <td>00: ODTU13</td> <td>00 0000: Tributary Port 1</td> </tr> <tr> <td>01: ODTU23</td> <td>00 0001: Tributary Port 2</td> </tr> <tr> <td>10: Reserved</td> <td>00 0010: Tributary Port 3</td> </tr> <tr> <td>11: Reserved</td> <td>00 0011: Tributary Port 4</td> </tr> <tr> <td></td> <td>⋮</td> </tr> <tr> <td></td> <td>00 1111: Tributary Port 16</td> </tr> </table> |   |                  |   |   |   |   |   |              | 00: ODTU13 | 00 0000: Tributary Port 1 | 01: ODTU23 | 00 0001: Tributary Port 2 | 10: Reserved | 00 0010: Tributary Port 3 | 11: Reserved | 00 0011: Tributary Port 4 |  | ⋮ |  | 00 1111: Tributary Port 16 |
+| 00: ODTU13      | 00 0000: Tributary Port 1                                                                                                                                                                                                                                                                                                                                                                        |   |                  |   |   |   |   |   |              |            |                           |            |                           |              |                           |              |                           |  |   |  |                            |
+| 01: ODTU23      | 00 0001: Tributary Port 2                                                                                                                                                                                                                                                                                                                                                                        |   |                  |   |   |   |   |   |              |            |                           |            |                           |              |                           |              |                           |  |   |  |                            |
+| 10: Reserved    | 00 0010: Tributary Port 3                                                                                                                                                                                                                                                                                                                                                                        |   |                  |   |   |   |   |   |              |            |                           |            |                           |              |                           |              |                           |  |   |  |                            |
+| 11: Reserved    | 00 0011: Tributary Port 4                                                                                                                                                                                                                                                                                                                                                                        |   |                  |   |   |   |   |   |              |            |                           |            |                           |              |                           |              |                           |  |   |  |                            |
+|                 | ⋮                                                                                                                                                                                                                                                                                                                                                                                                |   |                  |   |   |   |   |   |              |            |                           |            |                           |              |                           |              |                           |  |   |  |                            |
+|                 | 00 1111: Tributary Port 16                                                                                                                                                                                                                                                                                                                                                                       |   |                  |   |   |   |   |   |              |            |                           |            |                           |              |                           |              |                           |  |   |  |                            |
+
+**Figure 19-20B – OPU3 MSI coding – Payload type 20**
+
+**19.4.1.3 OPU1 multiplex structure identifier (MSI) – Payload type 20**
+
+For the 2 OPU1 1.25G tributary slots 2 bytes of the PSI are used (PSI[2], PSI[3]) as MSI bytes as shown in Figures 19-18A and 19-21. The MSI indicates the ODTU content of each tributary slot of the OPU1. One byte is used for each tributary slot.
+
+- The ODTU type in bits 1 and 2 is fixed to 11 to indicate the presence of an ODTU01.
+- The tributary port # in bits 3 to 8 indicates the port number of the ODTU01 that is being transported in this 1.25G TS; the assignment of ports to tributary slots is fixed, the port number equals the tributary slot number.
+
+![](5432eacbc055292cc3b3da108863b835_img.jpg)
+
+|               |    |   |         |   |   |   |   |   |          |            |
+|---------------|----|---|---------|---|---|---|---|---|----------|------------|
+|               | 1  | 2 | 3       | 4 | 5 | 6 | 7 | 8 | 1.25G TS |            |
+| <i>PSI[2]</i> | 11 |   | 00 0000 |   |   |   |   |   |          | <i>TS1</i> |
+| <i>PSI[3]</i> | 11 |   | 00 0001 |   |   |   |   |   |          | <i>TS2</i> |
+
+**Figure 19-21 – OPU1 MSI coding – Payload type 20**
+
+**19.4.1.4 OPU4 multiplex structure identifier (MSI) – Payload type 21**
+
+For the eighty OPU4 1.25G tributary slots 80 bytes of the PSI are used (PSI[2] to PSI[81]) as MSI bytes as shown in Figures 19-18C, 19-22A and 19-22B. The MSI indicates the ODTU content of each tributary slot of an OPU. One byte is used for each tributary slot.
+
+- The TS occupation bit 1 indicates if the tributary slot is allocated or unallocated.
+- The tributary port # in bits 2 to 8 indicates the port number of the ODTU4.ts that is being transported in this TS; for the case of an ODTU4.ts carried in two or more tributary slots, a flexible assignment of tributary port to tributary slots is possible. ODTU4.ts tributary ports are numbered 1 to 80. The value is set to all-0s when the occupation bit has the value 0 (tributary slot is unallocated).
+
+|                | 1           | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 1.25G TS    |
+|----------------|-------------|---|---|---|---|---|---|---|-------------|
+| <i>PSI[2]</i>  | TS occupied |   |   |   |   |   |   |   | <i>TS1</i>  |
+| <i>PSI[3]</i>  | TS occupied |   |   |   |   |   |   |   | <i>TS2</i>  |
+| <i>PSI[4]</i>  | TS occupied |   |   |   |   |   |   |   | <i>TS3</i>  |
+| <i>PSI[5]</i>  | TS occupied |   |   |   |   |   |   |   | <i>TS4</i>  |
+| <i>PSI[6]</i>  | TS occupied |   |   |   |   |   |   |   | <i>TS5</i>  |
+| <i>PSI[7]</i>  | TS occupied |   |   |   |   |   |   |   | <i>TS6</i>  |
+| <i>PSI[8]</i>  | TS occupied |   |   |   |   |   |   |   | <i>TS7</i>  |
+| <i>PSI[9]</i>  | TS occupied |   |   |   |   |   |   |   | <i>TS8</i>  |
+| :              | :           |   |   |   | : |   |   |   | :           |
+| :              | :           |   |   |   | : |   |   |   | :           |
+| <i>PSI[81]</i> | TS occupied |   |   |   |   |   |   |   | <i>TS80</i> |
+
+**Figure 19-22A – OPU4 1.25G TS MSI coding – Payload type 21**
+
+|                   | 1               | 2 | 3         | 4 | 5 | 6 | 7 | 8 |                   |
+|-------------------|-----------------|---|-----------|---|---|---|---|---|-------------------|
+| <i>PSI[1 + i]</i> | Occupation      |   |           |   |   |   |   |   | <i>TS #i</i>      |
+|                   |                 | : |           |   |   | : |   |   |                   |
+|                   | 0 : Unallocated |   | 000 0000: |   |   |   |   |   | Tributary Port 1  |
+|                   | 1 : Allocated   |   | 000 0001: |   |   |   |   |   | Tributary Port 2  |
+|                   |                 |   | 000 0010: |   |   |   |   |   | Tributary Port 3  |
+|                   |                 |   | 000 0011: |   |   |   |   |   | Tributary Port 4  |
+|                   |                 |   | :         |   |   |   |   |   |                   |
+|                   |                 |   | 100 1111: |   |   |   |   |   | Tributary Port 80 |
+
+**Figure 19-22B – OPU4 MSI coding – Payload type 21**
+
+#### 19.4.1.5 OPU2 multiplex structure identifier (MSI) – Payload type 21
+
+For the eight OPU2 1.25G tributary slots 8 bytes of the PSI (PSI[2] to PSI[9]) are used as MSI bytes as show in Figures 19-18B, 19-23A and 19-23B. The MSI indicates the ODTU content of each tributary slot of an OPU. One byte is used for each tributary slot.
+
+- The ODTU type in bits 1 and 2 indicates if the OPU2 1.25G TS is carrying an ODTU12 or ODTU2.ts. The default ODTU type is 11 (unallocated); it is present when a tributary slot is not allocated to carry an ODTU.
+- The tributary port # in bits 3 to 8 indicates the port number of the ODTU that is being transported in this TS; a flexible assignment of tributary ports to tributary slots is possible, ODTU12 tributary ports are numbered 1 to 4, and ODTU2.ts tributary ports are numbered 1 to 8. The value is set to all-0s when the ODTU type has the value 11 (tributary slot is unallocated).
+
+|               | 1         | 2 | 3 | 4 | 5                | 6 | 7 | 8 |            |
+|---------------|-----------|---|---|---|------------------|---|---|---|------------|
+| <i>PSI[2]</i> | ODTU type |   |   |   | Tributary Port # |   |   |   | <i>TS1</i> |
+| <i>PSI[3]</i> | ODTU type |   |   |   | Tributary Port # |   |   |   | <i>TS2</i> |
+| <i>PSI[4]</i> | ODTU type |   |   |   | Tributary Port # |   |   |   | <i>TS3</i> |
+| <i>PSI[5]</i> | ODTU type |   |   |   | Tributary Port # |   |   |   | <i>TS4</i> |
+| <i>PSI[6]</i> | ODTU type |   |   |   | Tributary Port # |   |   |   | <i>TS5</i> |
+| <i>PSI[7]</i> | ODTU type |   |   |   | Tributary Port # |   |   |   | <i>TS6</i> |
+| <i>PSI[8]</i> | ODTU type |   |   |   | Tributary Port # |   |   |   | <i>TS7</i> |
+| <i>PSI[9]</i> | ODTU type |   |   |   | Tributary Port # |   |   |   | <i>TS8</i> |
+
+**Figure 19-23A – OPU2 MSI coding – Payload type 21**
+
+|                   | 1               | 2 | 3 | 4 | 5                         | 6 | 7 | 8 |              |
+|-------------------|-----------------|---|---|---|---------------------------|---|---|---|--------------|
+| <i>PSI[1 + i]</i> | ODTU type       |   |   |   | Tributary Port #          |   |   |   | <i>TS #i</i> |
+|                   | ⋮               |   |   |   | ⋮                         |   |   |   |              |
+|                   | 00: ODTU12      |   |   |   | 00 0000: Tributary Port 1 |   |   |   |              |
+|                   | 01: Reserved    |   |   |   | 00 0001: Tributary Port 2 |   |   |   |              |
+|                   | 10: ODTU2.ts    |   |   |   | 00 0010: Tributary Port 3 |   |   |   |              |
+|                   | 11: Unallocated |   |   |   | 00 0011: Tributary Port 4 |   |   |   |              |
+|                   |                 |   |   |   | ⋮                         |   |   |   |              |
+|                   |                 |   |   |   | 00 0111: Tributary Port 8 |   |   |   |              |
+
+**Figure 19-23B – OPU2 MSI coding – Payload type 21**
+
+#### 19.4.1.6 OPU3 with 1.25G tributary slots (payload type 21) multiplex structure identifier (MSI)
+
+For the thirty-two OPU3 1.25G tributary slots 32 bytes of the PSI (PSI[2] to PSI[33]) are used as MSI bytes as shown in Figures 19-18B, 19-24A and 19-24B. The MSI indicates the ODTU content of each tributary slot of an OPU. One byte is used for each tributary slot.
+
+- The ODTU type in bits 1 and 2 indicates if the OPU3 1.25G TS is carrying an ODTU13, ODTU23 or ODTU3.ts. The default ODTU type is 11 (unallocated); it is present when a tributary slot is not allocated to carry an ODTU.
+- The tributary port # in bits 3 to 8 indicates the port number of the ODTU that is being transported in this TS; a flexible assignment of tributary ports to tributary slots is possible, ODTU13 tributary ports are numbered 1 to 16, ODTU23 tributary ports are numbered 1 to 4 and ODTU3.ts tributary ports are numbered 1 to 32. The value is set to all-0s when the ODTU type has the value 11 (tributary slot is unallocated).
+
+|                |           |   |                  |   |   |   |   |   |             |
+|----------------|-----------|---|------------------|---|---|---|---|---|-------------|
+|                | 1         | 2 | 3                | 4 | 5 | 6 | 7 | 8 |             |
+| <i>PSI[2]</i>  | ODTU type |   | Tributary Port # |   |   |   |   |   | <i>TS1</i>  |
+| <i>PSI[3]</i>  | ODTU type |   | Tributary Port # |   |   |   |   |   | <i>TS2</i>  |
+| <i>PSI[4]</i>  | ODTU type |   | Tributary Port # |   |   |   |   |   | <i>TS3</i>  |
+| <i>PSI[5]</i>  | ODTU type |   | Tributary Port # |   |   |   |   |   | <i>TS4</i>  |
+| <i>PSI[6]</i>  | ODTU type |   | Tributary Port # |   |   |   |   |   | <i>TS5</i>  |
+| :              | :         |   | :                |   |   |   |   |   | :           |
+| :              | :         |   | :                |   |   |   |   |   | :           |
+| <i>PSI[33]</i> | ODTU type |   | Tributary Port # |   |   |   |   |   | <i>TS32</i> |
+
+**Figure 19-24A – OPU3 MSI coding – Payload type 21**
+
+|                   |           |   |                  |   |   |   |   |   |              |
+|-------------------|-----------|---|------------------|---|---|---|---|---|--------------|
+|                   | 1         | 2 | 3                | 4 | 5 | 6 | 7 | 8 |              |
+| <i>PSI[1 + i]</i> | ODTU type |   | Tributary Port # |   |   |   |   |   | <i>TS #i</i> |
+
+00: ODTU13  
+ 01: ODTU23  
+ 10: ODTU3.ts  
+ 11: Unallocated
+
+00 0000: Tributary Port 1  
+ 00 0001: Tributary Port 2  
+ 00 0010: Tributary Port 3  
+ 00 0011: Tributary Port 4  
+ :  
+ 01 1111: Tributary Port 32
+
+**Figure 19-24B – OPU3 MSI coding – Payload type 21**
+
+### 19.4.1.7 OPU25 multiplex structure identifier (MSI) – Payload type 21
+
+For the twenty OPU25 1.25G tributary slots 20 bytes of the PSI are used (PSI[2] to PSI[21]) as MSI bytes as shown in Figures 19-18C, 19-25A and 19-25B. The MSI indicates the ODTU content of each tributary slot of an OPU. One byte is used for each tributary slot.
+
+- The TS occupation bit 1 indicates if the tributary slot is allocated or unallocated.
+- The tributary port # in bits 2 to 8 indicates the port number of the ODTU25.ts that is being transported in this TS; for the case of an ODTU25.ts carried in two or more tributary slots, a flexible assignment of tributary port to tributary slots is possible. ODTU25.ts tributary ports are numbered 1 to 20. The value is set to all-0s when the occupation bit has the value 0 (tributary slot is unallocated).
+
+**Rec. ITU-T G.709/Y.1331 (06/2020)**    149
+
+|                | 1           | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 1.25G TS    |
+|----------------|-------------|---|---|---|---|---|---|---|-------------|
+| <i>PSI[2]</i>  | TS occupied |   |   |   |   |   |   |   | <i>TS1</i>  |
+| <i>PSI[3]</i>  | TS occupied |   |   |   |   |   |   |   | <i>TS2</i>  |
+| <i>PSI[4]</i>  | TS occupied |   |   |   |   |   |   |   | <i>TS3</i>  |
+| <i>PSI[5]</i>  | TS occupied |   |   |   |   |   |   |   | <i>TS4</i>  |
+| <i>PSI[6]</i>  | TS occupied |   |   |   |   |   |   |   | <i>TS5</i>  |
+| :              | :           |   |   |   | : |   |   |   | :           |
+| :              | :           |   |   |   | : |   |   |   | :           |
+| <i>PSI[21]</i> | TS occupied |   |   |   |   |   |   |   | <i>TS20</i> |
+
+**Figure 19-25A – OPU25 1.25G TS MSI coding – Payload type 21**
+
+| <i>PSI[1 + i]</i> | 1               | 2                | 3     | 4 | 5 | 6 | 7 | 8 | <i>TS #i</i>      |
+|-------------------|-----------------|------------------|-------|---|---|---|---|---|-------------------|
+|                   | Occupation      |                  |       |   |   |   |   |   |                   |
+|                   |                 | Tributary Port # |       |   |   |   |   |   |                   |
+|                   |                 | :                |       |   |   | : |   |   |                   |
+|                   | 0 : Unallocated | 000              | 0000: |   |   |   |   |   | Tributary Port 1  |
+|                   | 1 : Allocated   | 000              | 0001: |   |   |   |   |   | Tributary Port 2  |
+|                   |                 | 000              | 0010: |   |   |   |   |   | Tributary Port 3  |
+|                   |                 | 000              | 0011: |   |   |   |   |   | Tributary Port 4  |
+|                   |                 | :                |       |   |   |   |   |   |                   |
+|                   |                 | 001              | 0011: |   |   |   |   |   | Tributary Port 20 |
+
+**Figure 19-25B – OPU25 MSI coding – Payload type 21**
+
+#### 19.4.1.8 OPU50 multiplex structure identifier (MSI) – Payload type 21
+
+For the forty OPU50 1.25G tributary slots 40 bytes of the PSI are used (PSI[2] to PSI[41]) as MSI bytes as shown in Figures 19-18C, 19-26A and 19-26B. The MSI indicates the ODTU content of each tributary slot of an OPU. One byte is used for each tributary slot.
+
+- The TS occupation bit 1 indicates if the tributary slot is allocated or unallocated.
+- The tributary port # in bits 2 to 8 indicates the port number of the ODTU50.ts that is being transported in this TS; for the case of an ODTU50.ts carried in two or more tributary slots, a flexible assignment of tributary port to tributary slots is possible. ODTU50.ts tributary ports are numbered 1 to 40. The value is set to all-0s when the occupation bit has the value 0 (tributary slot is unallocated).
+
+|                | 1           | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 1.25G TS    |
+|----------------|-------------|---|---|---|---|---|---|---|-------------|
+| <i>PSI[2]</i>  | TS occupied |   |   |   |   |   |   |   | <i>TS1</i>  |
+| <i>PSI[3]</i>  | TS occupied |   |   |   |   |   |   |   | <i>TS2</i>  |
+| <i>PSI[4]</i>  | TS occupied |   |   |   |   |   |   |   | <i>TS3</i>  |
+| <i>PSI[5]</i>  | TS occupied |   |   |   |   |   |   |   | <i>TS4</i>  |
+| <i>PSI[6]</i>  | TS occupied |   |   |   |   |   |   |   | <i>TS5</i>  |
+| <i>PSI[7]</i>  | TS occupied |   |   |   |   |   |   |   | <i>TS6</i>  |
+| :              | :           |   |   |   | : |   |   |   | :           |
+| :              | :           |   |   |   | : |   |   |   | :           |
+| <i>PSI[41]</i> | TS occupied |   |   |   |   |   |   |   | <i>TS40</i> |
+
+**Figure 19-26A – OPU50 1.25G TS MSI coding – Payload type 21**
+
+|                                                                                                                                                              | 1          | 2 | 3 | 4 | 5 | 6 | 7 | 8 |              |
+|--------------------------------------------------------------------------------------------------------------------------------------------------------------|------------|---|---|---|---|---|---|---|--------------|
+| <i>PSI[1 + i]</i>                                                                                                                                            | Occupation |   |   |   |   |   |   |   | <i>TS #i</i> |
+| <div style="display: flex; justify-content: space-around; align-items: center;"> <span>0 : Unallocated</span> <span>000 0000: Tributary Port 1</span> </div> |            |   |   |   |   |   |   |   |              |
+| <div style="display: flex; justify-content: space-around; align-items: center;"> <span>1 : Allocated</span> <span>000 0001: Tributary Port 2</span> </div>   |            |   |   |   |   |   |   |   |              |
+| <div style="display: flex; justify-content: space-around; align-items: center;"> <span></span> <span>000 0010: Tributary Port 3</span> </div>                |            |   |   |   |   |   |   |   |              |
+| <div style="display: flex; justify-content: space-around; align-items: center;"> <span></span> <span>000 0011: Tributary Port 4</span> </div>                |            |   |   |   |   |   |   |   |              |
+| <div style="display: flex; justify-content: space-around; align-items: center;"> <span>:</span> <span>:</span> </div>                                        |            |   |   |   |   |   |   |   |              |
+| <div style="display: flex; justify-content: space-around; align-items: center;"> <span></span> <span>010 0111: Tributary Port 40</span> </div>               |            |   |   |   |   |   |   |   |              |
+
+**Figure 19-26B – OPU50 MSI coding – Payload type 21**
+
+### 19.4.2 OPUk payload structure identifier reserved overhead (RES)
+
+253 (OPU1), 251 or 247 (OPU2), 239 or 223 (OPU3), 175 (OPU4), 234 (OPU25) and 214 (OPU50) bytes are reserved in the OPUk PSI for future international standardization. These bytes are located in PSI[1] and PSI[4] (OPU1), PSI[6] or PSI[10] (OPU2), PSI[18] or PSI[34] (OPU3), PSI[82] (OPU4), PSI[22] (OPU25), PSI[42] (OPU50) to PSI[255] of the OPUk overhead. These bytes are set to all-0s.
+
+### 19.4.3 OPUk multiplex justification overhead (JOH)
+
+Two mapping procedures are used for the mapping of ODUj: either the asynchronous mapping procedure (AMP) or generic mapping procedure (GMP) into ODTUjk or ODTUk.ts, respectively. AMP uses ODUj and OPUk specific fixed stuff and justification opportunity definitions (ODTUjk). GMP uses ODUj and OPUk independent stuff and justification opportunity definitions (ODTUk.ts). Stuff locations within an ODTUk.ts are determined by means of a formula which is specified in clause 19.4.3.2.
+
+#### 19.4.3.1 Asynchronous mapping procedures (AMP)
+
+The justification overhead (JOH) located in column 16 of the OPUk (k=1,2,3) as indicated in Figures 19-18A and 19-18B consists of three justification control (JC) bytes and one negative justification opportunity (NJO) byte. The three JC bytes are located in rows 1, 2 and 3. The NJO byte is located in row 4.
+
+Bits 7 and 8 of each JC byte are used for justification control. The other six bits are reserved for future international standardization.
+
+### 19.4.3.2 Generic mapping procedure (GMP)
+
+The justification overhead (JOH) for the generic mapping procedure consists of two groups of three bytes of justification control; the general (JC1, JC2, JC3) and the client to ODU mapping specific (JC4, JC5, JC6). Refer to Figure 19-18C.
+
+The JC1, JC2 and JC3 bytes consist of a 14-bit  $C_m$  field (bits C1, C2, ..., C14), a 1-bit increment indicator (II) field, a 1-bit decrement indicator (DI) field and an 8-bit CRC-8 field which contains an error check code over the JC1, JC2 and JC3 fields.
+
+The JC4, JC5 and JC6 bytes consist of a 10-bit  $\Sigma C_{nD}$  field (bits D1, D2, ..., D10), a 5-bit CRC-5 field which contains an error check code over bits 4 to 8 in the JC4, JC5 and JC6 fields and nine bits reserved for future international standardization (RES).
+
+The value of 'm' in  $C_m$  is  $8 \times 'ts'$  (number of tributary slots occupied by the ODTUk.ts).
+
+The value of 'n' represents the timing granularity of the GMP  $C_n$  parameter, which is also present in  $\Sigma C_{nD}$ . The value of n is 8.
+
+The value of  $C_m$  controls the distribution of groups of 'ts' ODUj data bytes into groups of 'ts' ODTUk.ts payload bytes. Refer to clause 19.6 and Annex D for further specification of this process.
+
+The value of  $\Sigma C_{nD}$  provides additional 'n'-bit timing information, which is necessary to control the jitter and wander performance experienced by the ODUj signal.
+
+The value of  $C_n$  (i.e., number of client n-bit data entities per OPUCn multiframe) is computed as follows:  $C_n(t) = m \times C_m(t) + (\Sigma C_{nD}(t) - \Sigma C_{nD}(t-1))$ . Note that the value  $C_{nD}$  is effectively an indication of the amount of data in the mapper's virtual queue that it could not send during that multiframe due to it being less than an M-byte word. For the case where the value of  $\Sigma C_{nD}$  in a multiframe 't' is corrupted, it is possible to recover from such error in the next multiframe 't+1'.
+
+### 19.4.4 OPU multiframe identifier overhead (OMFI)
+
+An OPU4 multiframe identifier (OMFI) byte is defined in row 4, column 16 of the OPU4 overhead (Figure 19-27). The value of bits 2 to 8 of the OMFI byte will be incremented each OPU4 frame to provide an 80 frame multiframe for the multiplexing of ODUj signals into the OPU4.
+
+NOTE – It is an option to align the OMFI = 0 position with MFAS = 0 position every 1280 (the least common multiple of 80 and 256) frame periods.
+
+![](d01f4371bb8136148156771a18b9ea89_img.jpg)
+
+| OMFI OH byte |   |   |   |   |   |   |   |               |
+|--------------|---|---|---|---|---|---|---|---------------|
+| 1            | 2 | 3 | 4 | 5 | 6 | 7 | 8 |               |
+| Fixed to 0   | : |   |   |   |   |   |   | OMFI sequence |
+|              | 0 | 0 | 0 | 0 | 0 | 0 | 0 |               |
+|              | 0 | 0 | 0 | 0 | 0 | 0 | 1 |               |
+|              | 0 | 0 | 0 | 0 | 0 | 1 | 0 |               |
+|              | 0 | 0 | 0 | 0 | 0 | 1 | 1 |               |
+|              | 0 | 0 | 0 | 0 | 1 | 0 | 0 |               |
+|              | : |   |   |   |   |   |   |               |
+|              | 1 | 0 | 0 | 1 | 1 | 1 | 0 |               |
+|              | 1 | 0 | 0 | 1 | 1 | 1 | 1 |               |
+|              | 0 | 0 | 0 | 0 | 0 | 0 | 0 |               |
+|              | 0 | 0 | 0 | 0 | 0 | 0 | 1 |               |
+|              | : |   |   |   |   |   |   |               |
+
+G.709-Y.1331(20)\_F19-27
+
+**Figure 19-27 – OPU4 multiframe identifier (OMFI) overhead**
+
+An OPU25 multiframe identifier (OMFI) byte is defined in row 4, column 16 of the OPU25 overhead (Figure 19-28). The value of bits 4 to 8 of the OMFI byte will be incremented each OPU25 frame to provide a 20 frame multiframe for the multiplexing of ODUj signals into the OPU25.
+
+NOTE – It is an option to align the OMFI = 0 position with MFAS = 0 position every 1280 (the least common multiple of 20 and 256) frame periods.
+
+![](c916a9fb4d2c440522379dedf3f76119_img.jpg)
+
+| OMFI OH byte |            |            |   |   |   |   |   |
+|--------------|------------|------------|---|---|---|---|---|
+| 1            | 2          | 3          | 4 | 5 | 6 | 7 | 8 |
+| Fixed to 0   | Fixed to 0 | Fixed to 0 | : |   |   |   |   |
+|              |            |            | 0 | 0 | 0 | 0 | 0 |
+|              |            |            | 0 | 0 | 0 | 0 | 1 |
+|              |            |            | 0 | 0 | 0 | 1 | 0 |
+|              |            |            | 0 | 0 | 0 | 1 | 1 |
+|              |            |            | 0 | 0 | 1 | 0 | 0 |
+|              |            |            | : | : | : | : | : |
+|              |            |            | 1 | 0 | 0 | 1 | 0 |
+|              |            |            | 1 | 0 | 0 | 1 | 1 |
+|              |            |            | 0 | 0 | 0 | 0 | 0 |
+|              |            |            | 0 | 0 | 0 | 0 | 1 |
+|              |            |            | : | : | : | : | : |
+
+G.709-Y.1331(20)\_F19-28
+
+Figure 19-28 – OPU25 multiframe identifier (OMFI) overhead
+
+An OPU50 multiframe identifier (OMFI) byte is defined in row 4, column 16 of the OPU50 overhead (Figure 19-29). The value of bits 3 to 8 of the OMFI byte will be incremented each OPU50 frame to provide a 40 frame multiframe for the multiplexing of ODUj signals into the OPU4.
+
+NOTE – It is an option to align the OMFI = 0 position with MFAS = 0 position every 1280 (the least common multiple of 40 and 256) frame periods.
+
+![](2d51fdeaad10ae6f1707dd372d200e23_img.jpg)
+
+| OMFI OH byte |            |   |   |   |   |   |   |
+|--------------|------------|---|---|---|---|---|---|
+| 1            | 2          | 3 | 4 | 5 | 6 | 7 | 8 |
+| Fixed to 0   | Fixed to 0 | : |   |   |   |   |   |
+|              |            |   | 0 | 0 | 0 | 0 | 0 |
+|              |            |   | 0 | 0 | 0 | 0 | 1 |
+|              |            |   | 0 | 0 | 0 | 1 | 0 |
+|              |            |   | 0 | 0 | 0 | 1 | 1 |
+|              |            |   | 0 | 0 | 0 | 1 | 0 |
+|              |            |   | : | : | : | : | : |
+|              |            |   | 1 | 0 | 0 | 1 | 0 |
+|              |            |   | 1 | 0 | 0 | 1 | 1 |
+|              |            |   | 0 | 0 | 0 | 0 | 0 |
+|              |            |   | 0 | 0 | 0 | 0 | 1 |
+|              |            |   | : | : | : | : | : |
+
+G.709-Y.1331(20)\_F19-29
+
+Figure 19-29 – OPU50 multiframe identifier (OMFI) overhead
+
+## 19.5 Mapping ODUj into ODTUjk
+
+The mapping of ODUj signals (with up to  $\pm 20$  ppm bit-rate tolerance) into the ODTUjk signal ( $(j,k) = \{(0,1), (1,2); (1,3), (2,3)\}$ ) is performed as an asynchronous mapping.
+
+NOTE 1 – The maximum bit-rate tolerance between OPUk and the ODUj signal clock, which can be accommodated by this mapping scheme is  $-130$  to  $+65$  ppm (ODU0 into OPU1),  $-113$  to  $+83$  ppm (ODU1 into OPU2),  $-96$  to  $+101$  ppm (ODU1 into OPU3) and  $-95$  to  $+101$  ppm (ODU2 into OPU3).
+
+The ODUj signal is extended with a frame alignment overhead as specified in clauses 15.6.2.1 and 15.6.2.2 and an all-0s pattern in the OTUj overhead field (see Figure 19-30).
+
+![Figure 19-30 – Extended ODUj frame structure. The diagram shows a grid with 4 rows and 3824 columns. Row 1 contains 'FA overhead area' (columns 1-7), 'Fixed stuff (all-0s)' (columns 8-14), and the start of the 'OPUj area' (columns 15-3824). Rows 2, 3, and 4 contain the 'ODUj overhead area' (columns 1-14) and the rest of the 'OPUj area' (columns 15-3824). The OPUj area is labeled as (4 x 3810 bytes).](42d1ffab6bbf720e8421aeace0808924_img.jpg)
+
+G.709-Y.1331(20)\_F19-30
+
+Figure 19-30 – Extended ODUj frame structure. The diagram shows a grid with 4 rows and 3824 columns. Row 1 contains 'FA overhead area' (columns 1-7), 'Fixed stuff (all-0s)' (columns 8-14), and the start of the 'OPUj area' (columns 15-3824). Rows 2, 3, and 4 contain the 'ODUj overhead area' (columns 1-14) and the rest of the 'OPUj area' (columns 15-3824). The OPUj area is labeled as (4 x 3810 bytes).
+
+**Figure 19-30 – Extended ODUj frame structure  
+(FA OH included, OTUj OH area contains fixed stuff)**
+
+The OPUk signal and therefore the ODTUjk (k = 1,2,3) signals are created from a locally generated clock (within the limits specified in Table 7-3), which is independent of the ODUj (j = 0,1,2) client signals.
+
+The extended ODUj (j = 0,1,2) signal is mapped into the ODTUjk (k = 1,2,3) using an asynchronous mapping with –1/0/+1/+2 positive/negative/zero (pnz) justification scheme.
+
+An extended ODUj byte is mapped into an ODTUjk byte.
+
+The asynchronous mapping process generates the JC, NJO, PJO1 and PJO2 according to Table 19-9. The de-mapping process interprets JC, NJO, PJO1 and PJO2 according to Table 19-9. Majority vote (two out of three) shall be used to make the justification decision in the de-mapping process to protect against an error in one of the three JC signals.
+
+**Table 19-9 – JC, NJO, PJO1 and PJO2 generation and interpretation**
+
+| <b>JC<br/>7 8</b> | <b>NJO</b>         | <b>PJO1</b>        | <b>PJO2</b>        | <b>Interpretation</b>              |
+|-------------------|--------------------|--------------------|--------------------|------------------------------------|
+| 0 0               | justification byte | data byte          | data byte          | no justification (0)               |
+| 0 1               | data byte          | data byte          | data byte          | negative justification (–1)        |
+| 1 0<br>(Note)     | justification byte | justification byte | justification byte | double positive justification (+2) |
+| 1 1               | justification byte | justification byte | data byte          | positive justification (+1)        |
+
+NOTE – Note that this code is not used for the case of ODU0 into OPU1.
+
+The value contained in NJO, PJO1 and PJO2 when they are used as justification bytes is all-0s. The receiver is required to ignore the value contained in these bytes whenever they are used as justification bytes.
+
+During a signal fail condition of the incoming ODUj client signal (e.g., OTUj-LOF), this failed incoming signal will contain the ODUj-AIS signal as specified in clause 16.5.1. This ODUj-AIS is then mapped into the ODTUjk.
+
+For the case where the ODUj is received from the output of a fabric (ODU connection function), the incoming signal may contain (in the case of an open matrix connection), the ODUj-OCI signal as specified in clause 16.5.2. This ODUj-OCI signal is then mapped into the ODTUjk.
+
+NOTE 2 – Not all equipment will have a real connection function (i.e., switch fabric) implemented; instead, the presence/absence of tributary interface port units represents the presence/absence of a matrix connection. If such a unit is intentionally absent (i.e., not installed), the associated ODTUjk signals should carry an ODUj-OCI signal. If such a unit is installed but temporarily removed as part of a repair action, the associated ODTUjk signal should carry an ODUj-AIS signal.
+
+The de-mapping of ODUj signals from the ODTUjk signal ( $j = 0,1,2$ ;  $k = 1,2,3$ ) is performed by extracting the extended ODUj signal from the OPUk under control of its justification overhead (JC, NJO, PJO1, PJO2).
+
+NOTE 3 – For the case where the ODUj signal is output as an OTUj signal, frame alignment of the extracted extended ODUj signal is to be recovered to allow frame synchronous mapping of the ODUj into the OTUj signal.
+
+During a signal fail condition of the incoming ODUk/OPUk signal (e.g., in the case of an ODUk-AIS, ODUk-LCK, ODUk-OCI condition) the ODUj-AIS pattern as specified in clause 16.5.1 is generated as a replacement signal for the lost ODUj signal.
+
+### **19.5.1 Mapping ODU1 into ODTU12**
+
+A byte of the ODU1 signal is mapped into an information byte of the ODTU12 (see Figure 19-31A). Once per 4 OPU2 frames, it is possible to perform either a positive or a negative justification action. The frame in which justification can be performed is related to the TSOH of the OPU2 2.5G TS in which the ODTU12 is mapped (Figure 19-1). Figure 19-31A shows the case with mapping in OPU2 2.5G TS1.
+
+A byte of the ODU1 signal is mapped into an information byte of the ODTU12 (see Figure 19-31B). Twice per 8 OPU2 frames, it is possible to perform either a positive or a negative justification action. The frames in which justification can be performed are related to the TSOH of the OPU2 1.25G TSs in which the ODTU12 is mapped (Figure 19-1). Figure 19-31B shows the case with mapping in OPU2 1.25G TS1 and TS4.
+
+![Diagram of ODTU12 frame format showing MFAS bits (78, 00, 01, 10, 11) and a grid of bytes with columns 1, 2, and 952. Rows are numbered 1-4 within each MFAS section. Bytes are labeled JC, NJO, PJO1, PJO2, and Information bytes.](b5ce6d659e1431289c2e79b01bf38a15_img.jpg)
+
+The diagram illustrates the ODTU12 frame structure. On the left, the MFAS (MultiFrame Alignment Signal) bits are shown in five groups: 78, 00, 01, 10, and 11. Each group corresponds to a set of four rows in the frame grid. The first column of each group contains a yellow box with 'JC' (for the first three groups) or 'NJO' (for the last two groups). The second column contains 'PJO1' and 'PJO2' in the first row of each group. The third column, labeled '952' at the top right, contains 'Information bytes' indicated by diagonal text. Columns 1 and 2 are labeled at the top of the grid.
+
+| MFAS bits | Row | 1   | 2 | 952               |
+|-----------|-----|-----|---|-------------------|
+| 78        | 1   | JC  |   | Information bytes |
+|           | 2   | JC  |   |                   |
+|           | 3   | JC  |   |                   |
+|           | 4   | NJO |   |                   |
+| 00        | 1   |     |   | Information bytes |
+|           | 2   |     |   |                   |
+|           | 3   |     |   |                   |
+|           | 4   |     |   |                   |
+| 01        | 1   |     |   | Information bytes |
+|           | 2   |     |   |                   |
+|           | 3   |     |   |                   |
+|           | 4   |     |   |                   |
+| 10        | 1   |     |   | Information bytes |
+|           | 2   |     |   |                   |
+|           | 3   |     |   |                   |
+|           | 4   |     |   |                   |
+| 11        | 1   |     |   | Information bytes |
+|           | 2   |     |   |                   |
+|           | 3   |     |   |                   |
+|           | 4   |     |   |                   |
+
+G.709/Y.1331(20)\_F19-31A
+
+Diagram of ODTU12 frame format showing MFAS bits (78, 00, 01, 10, 11) and a grid of bytes with columns 1, 2, and 952. Rows are numbered 1-4 within each MFAS section. Bytes are labeled JC, NJO, PJO1, PJO2, and Information bytes.
+
+**Figure 19-31A – ODTU12 frame format and mapping of ODU1 (mapping in 2.5G TS1)**
+
+![Diagram of ODTU12 frame format showing MFAS bits (000-111), overhead bytes (JC, NJO, PJO1, PJO2), and information bytes across 952 columns.](54f73f693f36dcbd300fa21ac4e410e8_img.jpg)
+
+The diagram illustrates the ODTU12 frame structure. On the left, the MFAS (MultiFrame Alignment Signal) bits are shown in groups of three: 000, 010, 011, 100, 101, 110, and 111. Each group is associated with a set of overhead bytes: JC, JC, NJO, and JC. The main frame consists of 952 columns. The first two columns are labeled '1' and '2'. Rows are numbered 1 through 4 within each MFAS group. The first row of each group contains the bytes PJO1 and PJO2 in columns 1 and 2 respectively. The remaining rows in each group are designated as 'Information bytes'. The total number of columns is 952, as indicated at the top right.
+
+Diagram of ODTU12 frame format showing MFAS bits (000-111), overhead bytes (JC, NJO, PJO1, PJO2), and information bytes across 952 columns.
+
+G.709/Y.1331(20)\_F19-31B
+
+**Figure 19-31B – ODTU12 frame format and mapping of ODU1  
+(mapping in 1.25G TS1 and TS4)**
+
+### 19.5.2 Mapping ODU1 into ODTU13
+
+A byte of the ODU1 signal is mapped into an information byte of the ODTU13 (Figure 19-32A). Column 119 of the ODTU13 is fixed stuff. An all-0s pattern is inserted in the fixed stuff bytes. Once per 16 OPU3 frames, it is possible to perform either a positive or a negative justification action. The frame in which justification can be performed is related to the TSOH of the OPU3 2.5G TS in which the ODTU13 is mapped (Figure 19-2). Figure 19-32A shows the case with mapping in OPU3 2.5G TS3.
+
+A byte of the ODU1 signal is mapped into an information byte of the ODTU13 (see Figure 19-32B). Column 119 of the ODTU13 is fixed stuff. An all-0s pattern is inserted in the fixed stuff bytes. Twice per 32 OPU3 frames, it is possible to perform either a positive or a negative justification action. The frames in which justification can be performed are related to the TSOH of the OPU3 1.25G TSs in which the ODTU13 is mapped (Figure 19-2). Figure 19-32B shows the case with mapping in OPU3 1.25G TS2 and TS25.
+
+![Figure 19-32A: ODTU13 frame format and mapping of ODU1 (mapping in 2.5G TS3).](c0438093a10a593c42106b1e5dbb4331_img.jpg)
+
+The diagram illustrates the ODTU13 frame structure and the mapping of ODU1 data. The frame is shown as a grid with 238 columns and 5678 rows (MFAS bits). Column 119 is designated as 'Fixed stuff' (highlighted in orange). Columns 1 and 2 are used for 'Information bytes'. The frame is divided into four sections based on the MFAS bits: 0000, 0001, 0010, and 1111. The 'Information bytes' are mapped into the grid, with the first two columns (1 and 2) containing the ODU1 data. The 'Fixed stuff' column (119) contains an all-0s pattern. The diagram also shows the mapping of ODU1 data into the 'Information bytes' area, with the first two columns (1 and 2) containing the ODU1 data. The 'Fixed stuff' column (119) contains an all-0s pattern. The diagram also shows the mapping of ODU1 data into the 'Information bytes' area, with the first two columns (1 and 2) containing the ODU1 data. The 'Fixed stuff' column (119) contains an all-0s pattern.
+
+MFAS bits: 5678
+
+Columns: 1, 2, ..., 119 (Fixed stuff), ..., 238
+
+Rows (MFAS bits): 0000, 0001, 0010, 1111
+
+Information bytes mapping: Columns 1 and 2 contain ODU1 data (P1O1, P1O2, etc.).
+
+Justification (JC) and Negative Justification (NJ0) are indicated in the 0010 section.
+
+G.709/Y.1331(20)\_F19-32A
+
+Figure 19-32A: ODTU13 frame format and mapping of ODU1 (mapping in 2.5G TS3).
+
+Figure 19-32A – ODTU13 frame format and mapping of ODU1 (mapping in 2.5G TS3)
+
+![Diagram of ODTU13 frame format and mapping of ODU1. The diagram shows three frame structures corresponding to MFAS bit values 45678 (00000), 00001, and 11111. Each frame is 238 bytes long, with columns 1, 2, 119, and 238 explicitly labeled. Column 119 is 'Fixed stuff'. Columns 1 and 2 contain overhead: NJO, JC, and PJO1/PJO2. Columns 3-118 and 120-237 contain 'Information bytes'. Vertical arrows on the left indicate the MFAS bit ranges for each frame structure. A label G.709/Y.1331(20)_F19-32B is at the bottom right.](12280970bb3eea7f6fbdc08200d444c2_img.jpg)
+
+MFAS bits
+
+45678
+
+00000
+
+00001
+
+00010
+
+11000
+
+11111
+
+1 2 119 238
+
+Information bytes
+
+Fixed stuff
+
+NJO JC JC JC
+
+PJO1 PJO2
+
+G.709/Y.1331(20)\_F19-32B
+
+Diagram of ODTU13 frame format and mapping of ODU1. The diagram shows three frame structures corresponding to MFAS bit values 45678 (00000), 00001, and 11111. Each frame is 238 bytes long, with columns 1, 2, 119, and 238 explicitly labeled. Column 119 is 'Fixed stuff'. Columns 1 and 2 contain overhead: NJO, JC, and PJO1/PJO2. Columns 3-118 and 120-237 contain 'Information bytes'. Vertical arrows on the left indicate the MFAS bit ranges for each frame structure. A label G.709/Y.1331(20)\_F19-32B is at the bottom right.
+
+**Figure 19-32B – ODTU13 frame format and mapping of ODU1 (mapping in 1.25G TS2 and TS25)**
+
+### 19.5.3 Mapping ODU2 into ODTU23
+
+A byte of the ODU2 signal is mapped into an information byte of the ODTU23 (Figure 19-33A). Four times per sixteen OPU3 frames, it is possible to perform either a positive or a negative justification action. The four frames in which justification can be performed are related to the TSOH of the OPU3 2.5G TSs in which the ODTU23 is mapped (Figure 19-2). Figure 19-33A shows the case with mapping in OPU3 2.5G TS1, TS5, TS9 and TS10.
+
+A byte of the ODU2 signal is mapped into an information byte of the ODTU23 (see Figure 19-33B). Eight times per 32 OPU3 frames, it is possible to perform either a positive or a negative justification action. The frames in which justification can be performed are related to the TSOH of the OPU3 1.25G TSs in which the ODTU23 is mapped (Figure 19-2). Figure 19-33B shows the case with mapping in OPU3 1.25G TS 1, 2, 5, 9, 10, 25, 26 and 32.
+
+![Figure 19-33A: ODTU23 frame format and mapping of ODU2. The diagram shows four frame structures for MFAS bits 0000, 0100, 1000, and 1111. Each frame has 952 columns and 4 rows. Columns 1 and 2 are highlighted. Rows 1, 2, and 3 contain 'JC' (Justification Control) bytes. Row 4 contains 'PJO1' and 'PJO2' bytes. The area between columns 2 and 952 is labeled 'Information bytes'. Vertical dotted lines separate the four frame structures.](826bf067afc22bf94cdd2faf3e595893_img.jpg)
+
+The diagram illustrates the ODTU23 frame format for four different MFAS bit values: 0000, 0100, 1000, and 1111. Each frame is shown as a grid with 952 columns and 4 rows. Columns 1 and 2 are highlighted in yellow. Rows 1, 2, and 3 are labeled with 'JC' (Justification Control) in yellow boxes. Row 4 is labeled with 'PJO1' and 'PJO2' in yellow boxes. The remaining area of the frame (columns 3 to 952) is labeled 'Information bytes'. Vertical dotted lines separate the four frame structures. The MFAS bits are indicated on the left of each frame structure.
+
+Figure 19-33A: ODTU23 frame format and mapping of ODU2. The diagram shows four frame structures for MFAS bits 0000, 0100, 1000, and 1111. Each frame has 952 columns and 4 rows. Columns 1 and 2 are highlighted. Rows 1, 2, and 3 contain 'JC' (Justification Control) bytes. Row 4 contains 'PJO1' and 'PJO2' bytes. The area between columns 2 and 952 is labeled 'Information bytes'. Vertical dotted lines separate the four frame structures.
+
+G.709/Y.1331(20)\_F19-33A
+
+**Figure 19-33A – ODTU23 frame format and mapping of ODU2  
+(mapping in 2.5G TS 1,5,9,10)**
+
+![Diagram showing the ODTU23 frame format and mapping of ODU2. It displays five sections corresponding to bit ranges 00000, 00100, 01000, 11000, and 11111. Each section shows a grid of bytes with columns 1 and 2, and rows 1 through 4. Columns 1 and 2 are labeled 'Information bytes'. Rows 1-3 are empty. Row 4 contains bytes P1O1 and P1O2. The left side of each section shows MFAS bits (45678, 00000, 00100, 01000, 01001, 11000, 11001, 11111) and a sequence of JC and NJO bytes. The right side of the grid is labeled 952.](669c88c4149a2add62ce1cbc7e8bb659_img.jpg)
+
+The diagram illustrates the ODTU23 frame structure for mapping ODU2. It is divided into five horizontal sections based on MFAS bit patterns: 00000, 00100, 01000, 11000, and 11111. Each section contains a grid of bytes. The first two columns are designated as 'Information bytes'. Rows 1, 2, and 3 are empty. Row 4 contains two bytes, P1O1 and P1O2. To the left of each grid, the MFAS bits are shown (45678, 00000, 00100, 01000, 01001, 11000, 11001, 11111), and a sequence of JC and NJO bytes is listed. The rightmost column of the grid is labeled 952. Vertical dashed lines separate the sections.
+
+Diagram showing the ODTU23 frame format and mapping of ODU2. It displays five sections corresponding to bit ranges 00000, 00100, 01000, 11000, and 11111. Each section shows a grid of bytes with columns 1 and 2, and rows 1 through 4. Columns 1 and 2 are labeled 'Information bytes'. Rows 1-3 are empty. Row 4 contains bytes P1O1 and P1O2. The left side of each section shows MFAS bits (45678, 00000, 00100, 01000, 01001, 11000, 11001, 11111) and a sequence of JC and NJO bytes. The right side of the grid is labeled 952.
+
+G.709/Y.1331(20)\_F19-33B
+
+**Figure 19-33B – ODTU23 frame format and mapping of ODU2  
+(mapping in 1.25G TS 1,2,5,9,10,25,26,32)**
+
+### 19.5.4 Mapping ODU0 into ODTU01
+
+A byte of the ODU0 signal is mapped into an information byte of the ODTU01 (see Figure 19-34). Once per 2 OPU1 frames, it is possible to perform either a positive or a negative justification action.
+
+The frame in which justification can be performed is related to the TSOH of the OPU1 TS in which the ODTU01 is mapped (Figure 19-3). Figure 19-34 shows the case with mapping in OPU1 TS1.
+
+NOTE – The PJO2 field will always carry an information byte.
+
+![Figure 19-34: Mapping of ODU0 in OPU1 TS1. The diagram shows a grid of bytes. The vertical axis is labeled 'MFAS bits' with values 8, 0, and 1. The horizontal axis is labeled with byte indices 1, 2, and 1904. The grid is divided into two main sections. The top section (MFAS bits 8 to 0) contains 4 rows. Row 1 has columns 1 and 2, followed by a large area labeled 'Information bytes', and a final column. Row 2 has columns 1 and 2, followed by a large area labeled 'Information bytes', and a final column. Row 3 has columns 1 and 2, followed by a large area labeled 'Information bytes', and a final column. Row 4 has columns 1 and 2, followed by a large area labeled 'Information bytes', and a final column. The bottom section (MFAS bits 0 to 1) contains 4 rows. Row 1 has columns 1 and 2, followed by a large area labeled 'Information bytes', and a final column. Row 2 has columns 1 and 2, followed by a large area labeled 'Information bytes', and a final column. Row 3 has columns 1 and 2, followed by a large area labeled 'Information bytes', and a final column. Row 4 has columns 1 and 2, followed by a large area labeled 'Information bytes', and a final column. On the left side of the grid, there are labels for the bytes: RES, JC, PSI, NIO, RES, TS2 JOH. The first byte in each row is labeled with these values. The second byte in each row is labeled with PJO1 and PJO2.](b18f943d96bfcb2b1360a27b9e45e11e_img.jpg)
+
+Figure 19-34: Mapping of ODU0 in OPU1 TS1. The diagram shows a grid of bytes. The vertical axis is labeled 'MFAS bits' with values 8, 0, and 1. The horizontal axis is labeled with byte indices 1, 2, and 1904. The grid is divided into two main sections. The top section (MFAS bits 8 to 0) contains 4 rows. Row 1 has columns 1 and 2, followed by a large area labeled 'Information bytes', and a final column. Row 2 has columns 1 and 2, followed by a large area labeled 'Information bytes', and a final column. Row 3 has columns 1 and 2, followed by a large area labeled 'Information bytes', and a final column. Row 4 has columns 1 and 2, followed by a large area labeled 'Information bytes', and a final column. The bottom section (MFAS bits 0 to 1) contains 4 rows. Row 1 has columns 1 and 2, followed by a large area labeled 'Information bytes', and a final column. Row 2 has columns 1 and 2, followed by a large area labeled 'Information bytes', and a final column. Row 3 has columns 1 and 2, followed by a large area labeled 'Information bytes', and a final column. Row 4 has columns 1 and 2, followed by a large area labeled 'Information bytes', and a final column. On the left side of the grid, there are labels for the bytes: RES, JC, PSI, NIO, RES, TS2 JOH. The first byte in each row is labeled with these values. The second byte in each row is labeled with PJO1 and PJO2.
+
+G.709/Y.1331(20)\_F19-34
+
+Figure 19-34 – Mapping of ODU0 in OPU1 TS1
+
+### 19.6 Mapping of ODUj into ODTUk.ts
+
+The mapping of ODUj (j = 0, 1, 2, 2e, 3, flex) signals (with up to  $\pm 100$  ppm bit-rate tolerance) into the ODTUk.ts (k = 2,3,4,25,50; ts = M) signal is performed by means of a generic mapping procedure as specified in Annex D.
+
+The OPUk and therefore the ODTUk.ts (k = 2,3,4,25,50) signals are created from a locally generated clock (within the limits specified in Table 7-3), which is independent of the ODUj client signal.
+
+The ODUj signal is extended with a frame alignment overhead as specified in clauses 15.6.2.1 and 15.6.2.2 and an all-0s pattern in the OTUj overhead field (see Figure 19-30).
+
+The extended ODUj signal is adapted to the locally generated OPUk/ODTUk.ts clock by means of a generic mapping procedure (GMP) as specified in Annex D. The value of n in  $c_n$  and  $C_n(t)$  and  $C_{nD}(t)$  is specified in Annex D. The value of M is the number of tributary slots occupied by the ODUj; ODTUk.ts = ODTUk.M.
+
+A group of 'M' successive extended ODUj bytes is mapped into a group of 'M' successive ODTUk.M bytes.
+
+The generic mapping process generates for the case of ODUj (j = 0,1,2,2e,3,flex) signals once per ODTUk.M multiframe the  $C_m(t)$  and  $C_{nD}(t)$  information according to Annex D and encodes this information in the ODTUk.ts justification control overhead JC1/JC2/JC3 and JC4/JC5/JC6. The de-mapping process decodes  $C_m(t)$  and  $C_{nD}(t)$  from JC1/JC2/JC3 and JC4/JC5/JC6 and interprets  $C_m(t)$  and  $C_{nD}(t)$  according to Annex D. CRC-8 shall be used to protect against an error in JC1,JC2,JC3 signals. CRC-5 shall be used to protect against an error in JC4,JC5,JC6 signals.
+
+During a signal fail condition of the incoming ODUj signal, this failed incoming signal will contain the ODUj-AIS signal as specified in clause 16.5.1. This ODUj-AIS is then mapped into the ODTUk.M.
+
+For the case where the ODUj is received from the output of a fabric (ODU connection function), the incoming signal may contain (in the case of an open matrix connection) the ODUj-OCI signal as specified in clause 16.5.2. This ODUj-OCI signal is then mapped into the ODTUk.M.
+
+NOTE 1 – Not all equipment will have a real connection function (i.e., switch fabric) implemented; instead, the presence/absence of tributary interface port units represents the presence/absence of a matrix connection. If such a unit is intentionally absent (i.e., not installed), the associated ODTUk.M signals should carry an ODUj-OCI signal. If such a unit is installed but temporarily removed as part of a repair action, the associated ODTUk.M signal should carry an ODUj-AIS signal.
+
+A group of 'M' successive extended ODUj bytes is de-mapped from a group of 'M' successive ODTUk.M bytes.
+
+NOTE 2 – For the case where the ODUj signal is output as an OTUj signal, frame alignment of the extracted extended ODUj signal is to be recovered to allow frame synchronous mapping of the ODUj into the OTUj signal.
+
+During a signal fail condition of the incoming ODUk/OPUk signal (e.g., in the case of an ODUk-AIS, ODUk-LCK, ODUk-OCI condition) the ODUj-AIS pattern as specified in clause 16.5.1 is generated as a replacement signal for the lost ODUj signal.
+
+The values of M, m, C<sub>m,min</sub>, C<sub>m,max</sub>, n, C<sub>n,min</sub> and C<sub>n,max</sub> for ODUj into ODTUk.ts are as follows:
+
+$$M = \text{ceiling} \left( \frac{ODUj\_nom\_bit\_rate \times (1 + ODUj\_bit\_rate\_tolerance + 0.00006)}{(ODTUk.1\_nom\_bit\_rate \times (1 - ODTUk.ts\_bit\_rate\_tolerance))} \right) \text{ for ODUj with } j \neq \text{flex}(\text{GFP}, n, k') \quad (19-1a)$$
+
+$$M = \left( \frac{ODUj\_nom\_bit\_rate}{ODUk'.ts} \right) = n \text{ for ODUj with } j = \text{flex}(\text{GFP}, n, k') \text{ and } k' \leq k \text{ with } k' \in \{2, 3, 4\} \quad (19-1b)$$
+
+$$m = 8 \times M \quad (19-2)$$
+
+$$c_{m,nom} = \left( \frac{ODUj\_nom\_bit\_rate \times \text{Number\_of\_GMP\_blocks\_in\_ODTUk.ts}}{ODTUk.1\_nom\_bit\_rate \times M} \right) \quad (19-3)$$
+
+$$c_{m,min} = c_{m,nom} \times \left( \frac{1 - ODUj\_bit\_rate\_tolerance}{1 + ODTUk.1\_bit\_rate\_tolerance} \right) \quad (19-4)$$
+
+$$c_{m,max} = c_{m,nom} \times \left( \frac{1 + ODUj\_bit\_rate\_tolerance}{1 - ODTUk.1\_bit\_rate\_tolerance} \right) \quad (19-5)$$
+
+$$C_{m,min} = \text{floor}(c_{m,min}) \quad (19-6)$$
+
+$$C_{m,max} = \text{ceiling}(c_{m,max}) \quad (19-7)$$
+
+$$n = 8 \quad (19-8)$$
+
+$$c_{n,nom} = \left( \frac{ODUj\_nom\_bit\_rate \times \text{Number\_of\_GMP\_blocks\_in\_ODTUk.ts}}{ODTUk.1\_nom\_bit\_rate} \right) \quad (19-9)$$
+
+$$c_{n,min} = c_{n,nom} \times \left( \frac{1 - ODUj\_bit\_rate\_tolerance}{1 + ODTUk.1\_bit\_rate\_tolerance} \right) \quad (19-10)$$
+
+$$c_{n,max} = c_{n,nom} \times \left( \frac{1 + ODUj\_bit\_rate\_tolerance}{1 - ODTUk.1\_bit\_rate\_tolerance} \right) \quad (19-11)$$
+
+$$C_{n,min} = floor(c_{n,min}) \quad (19-12)$$
+
+$$C_{n,max} = ceiling(c_{n,max}) \quad (19-13)$$
+
+$C_{m,min}$ ,  $C_{n,min}$  ( $n=8$ ),  $C_{m,max}$  and  $C_{n,max}$  ( $n=8$ ) values represent the boundaries of ODUj/ODTUk.M ppm offset combinations (i.e., min. ODUj/max. ODTUk.M and max. ODUj/min. ODTUk.M). In steady state, given instances of ODUk/ODTUk.M offset combinations should not result in generated  $C_n$  and  $C_m$  values throughout this range but rather should be within as small a range as possible.
+
+NOTE – Under transient ppm offset conditions (e.g., AIS to normal signal), it is possible that  $C_n$  and  $C_m$  values outside the range  $C_{n,min}$  to  $C_{n,max}$  and  $C_{m,min}$  to  $C_{m,max}$  may be generated and a GMP de-mapper should be tolerant of such occurrences. Refer to Annex D for a general description of the GMP principles.
+
+### 19.6.1 Mapping ODUj into ODTU2.M
+
+Groups of M successive bytes of the extended ODUj ( $j = 0, flex$ ) signal are mapped into a group of M successive bytes of the ODTU2.M payload area under control of the GMP data/stuff control mechanism. Each group of M bytes in the ODTU2.M payload area may either carry M ODU bytes, or carry M stuff bytes. The value of the stuff bytes is set to all-0s.
+
+The groups of M bytes in the ODTU2.M payload area are numbered from 1 to 15232.
+
+The ODTU2.M payload byte numbering for GMP M-byte (m-bit) blocks is illustrated in Figure 19-35. In row 1 of the ODTU2.M multiframe the first M-bytes will be labelled 1, the next M-bytes will be labelled 2, etc.
+
+![Figure 19-35: ODTU2.M GMP byte numbering diagram. It shows a table of byte numbers across 32 rows. The first column is 'ODTU2.M overhead' with values 1, 477, 953, 1429. The next columns are 'M', 'M+1', '2M', 'ODTU2.M payload' (starting at 475M+1), and '476M'. Row 1 has values 1, 1, 2, 2, 476, 476. Row 2 has 477, 477, 478, 478, 952, 952. Row 3 has 953, 953, 954, 954, 1428, 1428. Row 4 has 1429, 1429, 1430, 1430, 1904, 1904. Row 31 has 14281, 14281, 14282, 14282, 14756, 14756. Row 32 has 14757, 14757, 14758, 14758, 15232, 15232. Vertical ellipses indicate intermediate rows. A small grid icon is on the left.](3757cff99b0ef34e2262435d7f8f6dfd_img.jpg)
+
+Figure 19-35: ODTU2.M GMP byte numbering diagram. It shows a table of byte numbers across 32 rows. The first column is 'ODTU2.M overhead' with values 1, 477, 953, 1429. The next columns are 'M', 'M+1', '2M', 'ODTU2.M payload' (starting at 475M+1), and '476M'. Row 1 has values 1, 1, 2, 2, 476, 476. Row 2 has 477, 477, 478, 478, 952, 952. Row 3 has 953, 953, 954, 954, 1428, 1428. Row 4 has 1429, 1429, 1430, 1430, 1904, 1904. Row 31 has 14281, 14281, 14282, 14282, 14756, 14756. Row 32 has 14757, 14757, 14758, 14758, 15232, 15232. Vertical ellipses indicate intermediate rows. A small grid icon is on the left.
+
+Figure 19-35 – ODTU2.M GMP byte numbering
+
+### 19.6.2 Mapping ODUj into ODTU3.M
+
+Groups of M successive bytes of the extended ODUj ( $j = 0, 2e, flex$ ) signal are mapped into a group of M successive bytes of the ODTU3.M payload area under control of the GMP data/stuff control mechanism. Each group of M bytes in the ODTU3.M payload area may either carry M ODU bytes, or carry M stuff bytes. The value of the stuff bytes is set to all-0s.
+
+The groups of M bytes in the ODTU3.M payload area are numbered from 1 to 15232.
+
+The ODTU3.M payload byte numbering for GMP M-byte (m-bit) blocks is illustrated in Figure 19-36. In row 1 of the ODTU3.M multiframe the first M-bytes will be labelled 1, the next M-bytes will be labelled 2, etc.
+
+![Figure 19-36 – ODTU3.M GMP byte numbering diagram. It shows a grid of bytes with columns for overhead and payload. Columns are labeled 1, M, M+1, 2M, ODTU3.M payload (from 118M+1 to 119M). Rows are numbered 1 to 128. Specific byte values are shown in the first and last rows for each column group.](d72d5d32956ba002d9fe93678b8975d0_img.jpg)
+
+Figure 19-36 illustrates the byte numbering for ODTU3.M. The structure includes an overhead section and a payload section. The payload section is divided into blocks of M bytes. The diagram shows the first and last rows of bytes for each column group. Row 1 shows bytes 1, 1, 2, 2, ..., 119, 119. Row 128 shows bytes 14995, 14995, 14996, 14996, ..., 15113, 15113. Row 129 shows bytes 15114, 15114, 15115, 15115, ..., 15232, 15232.
+
+Figure 19-36 – ODTU3.M GMP byte numbering diagram. It shows a grid of bytes with columns for overhead and payload. Columns are labeled 1, M, M+1, 2M, ODTU3.M payload (from 118M+1 to 119M). Rows are numbered 1 to 128. Specific byte values are shown in the first and last rows for each column group.
+
+G.709-Y.1331(20)\_F19-36
+
+**Figure 19-36 – ODTU3.M GMP byte numbering**
+
+### 19.6.3 Mapping ODUj into ODTU4.M
+
+Groups of M successive bytes of the extended ODUj (j = 0, 1, 2, 2e, 3, flex) signal are mapped into a group of M successive bytes of the ODTU4.M payload area under control of the GMP data/stuff control mechanism. Each group of M bytes in the ODTU4.M payload area may either carry M ODU bytes, or carry M stuff bytes. The value of the stuff bytes is set to all-0s.
+
+The groups of M bytes in the ODTU4.M payload area are numbered from 1 to 15200.
+
+The ODTU4.M payload byte numbering for GMP M-byte (m-bit) blocks is illustrated in Figure 19-37. In row 1 of the ODTU4.M multiframe the first M-bytes will be labelled 1, the next M-bytes will be labelled 2, etc.
+
+![Figure 19-37 – ODTU4.M GMP byte numbering diagram. It shows a grid of bytes with columns for overhead and payload. Columns are labeled 1, M, M+1, 2M, ODTU4.M payload (from 94M+1 to 95M). Rows are numbered 1 to 160. Specific byte values are shown in the first and last rows for each column group.](7fee3dcb5487529210cd0dea013d08db_img.jpg)
+
+Figure 19-37 illustrates the byte numbering for ODTU4.M. The structure includes an overhead section and a payload section. The payload section is divided into blocks of M bytes. The diagram shows the first and last rows of bytes for each column group. Row 1 shows bytes 1, 1, 2, 2, ..., 95, 95. Row 160 shows bytes 15011, 15011, 15012, 15012, ..., 15105, 15105. Row 161 shows bytes 15106, 15106, 15107, 15107, ..., 15200, 15200.
+
+Figure 19-37 – ODTU4.M GMP byte numbering diagram. It shows a grid of bytes with columns for overhead and payload. Columns are labeled 1, M, M+1, 2M, ODTU4.M payload (from 94M+1 to 95M). Rows are numbered 1 to 160. Specific byte values are shown in the first and last rows for each column group.
+
+G.709-Y.1331(20)\_F19-37
+
+**Figure 19-37 – ODTU4.M GMP byte numbering**
+
+### 19.6.4 Mapping ODUj into ODTU25.M
+
+Groups of M successive bytes of the extended ODUj (j = 0, 1, 2, 2e, flex) signal are mapped into a group of M successive bytes of the ODTU25.M payload area under control of the GMP data/stuff control mechanism. Each group of M bytes in the ODTU25.M payload area may either carry M ODU bytes, or carry M stuff bytes. The value of the stuff bytes is set to all-0s.
+
+The groups of M bytes in the ODTU25.M payload area are numbered from 1 to 15232.
+
+The ODTU25.M payload byte numbering for GMP M-byte (m-bit) blocks is illustrated in Figure 19-38. In row 1 of the ODTU25.M multiframe the first M-bytes will be labelled 1, the next M-bytes will be labelled 2, etc.
+
+![Figure 19-38: ODTU25.M GMP byte numbering diagram. It shows a table with columns for ODUj bytes (1 to M, M+1 to 2M) and ODTU25.M payload bytes (1 to 951M+1, 952M). Rows are numbered 1 to 16. The first row shows ODUj bytes 1, 2, 953, 954, 1905, 1906, 2857, 2858 mapping to payload bytes 1, 2, 952, 1904, 2856, 3808. The last row shows ODUj bytes 13329, 13330, 14281, 14282 mapping to payload bytes 14280, 15232.](330e22134db7091a48c4c2366006c0d4_img.jpg)
+
+Figure 19-38 illustrates the byte numbering for ODTU25.M. The diagram shows a table with columns for ODUj bytes (1 to M, M+1 to 2M) and ODTU25.M payload bytes (1 to 951M+1, 952M). Rows are numbered 1 to 16. The first row shows ODUj bytes 1, 2, 953, 954, 1905, 1906, 2857, 2858 mapping to payload bytes 1, 2, 952, 1904, 2856, 3808. The last row shows ODUj bytes 13329, 13330, 14281, 14282 mapping to payload bytes 14280, 15232.
+
+| ODTU25.M overhead |  | ODTU25.M payload |       |       |        |       |
+|-------------------|--|------------------|-------|-------|--------|-------|
+| 1                 |  | M                | M+1   | 2M    | 951M+1 | 952M  |
+| 1                 |  | 1                | 2     | 2     | 952    | 952   |
+| 953               |  | 953              | 954   | 954   | 1904   | 1904  |
+| 1905              |  | 1905             | 1906  | 1906  | 2856   | 2856  |
+| 2857              |  | 2857             | 2858  | 2858  | 3808   | 3808  |
+| ⋮                 |  | ⋮                | ⋮     | ⋮     | ⋮      | ⋮     |
+| 13329             |  | 13329            | 13330 | 13330 | 14280  | 14280 |
+| 14281             |  | 14281            | 14282 | 14282 | 15232  | 15232 |
+
+G.709-Y.1331(20)\_F19-38
+
+Figure 19-38: ODTU25.M GMP byte numbering diagram. It shows a table with columns for ODUj bytes (1 to M, M+1 to 2M) and ODTU25.M payload bytes (1 to 951M+1, 952M). Rows are numbered 1 to 16. The first row shows ODUj bytes 1, 2, 953, 954, 1905, 1906, 2857, 2858 mapping to payload bytes 1, 2, 952, 1904, 2856, 3808. The last row shows ODUj bytes 13329, 13330, 14281, 14282 mapping to payload bytes 14280, 15232.
+
+Figure 19-38 – ODTU25.M GMP byte numbering
+
+### 19.6.5 Mapping ODUj into ODTU50.M
+
+Groups of M successive bytes of the extended ODUj (j = 0, 1, 2, 2e, 3, flex) signal are mapped into a group of M successive bytes of the ODTU50.M payload area under control of the GMP data/stuff control mechanism. Each group of M bytes in the ODTU50.M payload area may either carry M ODU bytes, or carry M stuff bytes. The value of the stuff bytes is set to all-0s.
+
+The groups of M bytes in the ODTU50.M payload area are numbered from 1 to 15232.
+
+The ODTU50.M payload byte numbering for GMP M-byte (m-bit) blocks is illustrated in Figure 19-39. In row 1 of the ODTU50.M multiframe the first M-bytes will be labelled 1, the next M-bytes will be labelled 2, etc.
+
+![Figure 19-39: ODTU50.M GMP byte numbering diagram. It shows a table with columns for ODUj bytes (1 to M, M+1 to 2M) and ODTU50.M payload bytes (1 to 475M+1, 476M). Rows are numbered 1 to 32. The first row shows ODUj bytes 1, 2, 477, 478, 953, 954, 1429, 1430 mapping to payload bytes 1, 2, 476, 952, 1428, 1904. The last row shows ODUj bytes 14281, 14282, 14757, 14756 mapping to payload bytes 14756, 15232.](ddd3dabf3c4bc1bf46fb74ec9330e3fa_img.jpg)
+
+Figure 19-39 illustrates the byte numbering for ODTU50.M. The diagram shows a table with columns for ODUj bytes (1 to M, M+1 to 2M) and ODTU50.M payload bytes (1 to 475M+1, 476M). Rows are numbered 1 to 32. The first row shows ODUj bytes 1, 2, 477, 478, 953, 954, 1429, 1430 mapping to payload bytes 1, 2, 476, 952, 1428, 1904. The last row shows ODUj bytes 14281, 14282, 14757, 14756 mapping to payload bytes 14756, 15232.
+
+| ODTU50.M overhead |  | ODTU50.M payload |       |       |        |       |
+|-------------------|--|------------------|-------|-------|--------|-------|
+| 1                 |  | M                | M+1   | 2M    | 475M+1 | 476M  |
+| 1                 |  | 1                | 2     | 2     | 476    | 476   |
+| 477               |  | 477              | 478   | 478   | 952    | 952   |
+| 953               |  | 953              | 954   | 954   | 1428   | 1428  |
+| 1429              |  | 1429             | 1430  | 1430  | 1904   | 1904  |
+| ⋮                 |  | ⋮                | ⋮     | ⋮     | ⋮      | ⋮     |
+| 14281             |  | 14281            | 14282 | 14282 | 14756  | 14756 |
+| 14757             |  | 14757            | 14756 | 14756 | 15232  | 15232 |
+
+G.709-Y.1331(20)\_F19-39
+
+Figure 19-39: ODTU50.M GMP byte numbering diagram. It shows a table with columns for ODUj bytes (1 to M, M+1 to 2M) and ODTU50.M payload bytes (1 to 475M+1, 476M). Rows are numbered 1 to 32. The first row shows ODUj bytes 1, 2, 477, 478, 953, 954, 1429, 1430 mapping to payload bytes 1, 2, 476, 952, 1428, 1904. The last row shows ODUj bytes 14281, 14282, 14757, 14756 mapping to payload bytes 14756, 15232.
+
+Figure 19-39 – ODTU50.M GMP byte numbering
+
+## 20 Mapping ODUk signals into the ODTUCn signal and the ODTUCn into the OPUCn tributary slots
+
+This clause specifies the multiplexing of:
+
+- ODUk into OPUCn using a client agnostic generic mapping procedure (GMP).
+
+This ODUk into OPUCn multiplexing is performed in two steps:
+
+- 1) asynchronous mapping of ODUk into optical data tributary unit (ODTUCn) using GMP;
+- 2) byte-synchronous mapping of ODTUCn into one or more OPUCn tributary slots.
+
+The OPUCn supports up to 10n different ODUk signals.
+
+### 20.1 OPUCn tributary slot definition
+
+The OPUCn consists of n OPUC. Each OPUC is divided into 20 tributary slots (TS) and these tributary slots are 16-byte interleaved within the OPUC payload area. A tributary slot includes a part of the OPUC OH area and a part of the OPUC payload area. The bytes of the ODUk frame are mapped into the ODTUCn payload area and the ODTUCn bytes are mapped into the OPUCn tributary slot or slots. The bytes of the ODTUCn justification overhead are mapped into the OPUCn OH area.
+
+There is *only* one type of tributary slot:
+
+- 1) Tributary slot with a bandwidth of approximately 5 Gbit/s; an OPUCn is divided into 20n tributary slots, numbered 1.1 to n.20.
+
+#### 20.1.1 OPUCn tributary slot allocation
+
+Figures 20-1 and 20-2 present the OPUC 5G tributary slot allocation. An OPUC is divided into 20 5G tributary slots (named TS #A.B where A = 1...n which denotes the number of the OPUC within the OPUCn and B = 1...20 which denotes the number of the TS within the OPUC), which are located in columns 17 to 3824. The OPUC multi-frame may be represented in an 80 row by 3810 column format (Figure 20-1) and in a 8 row by 38100 column format (Figure 20-2).
+
+An OPUC 5G tributary slot occupies 5% of the OPUC payload area. It is a structure with 119 16-byte columns by  $8/(20 \times 4/10)$  rows (see Figure 20-2) plus a tributary slot overhead (TSOH). The 20 OPUC 5G TSs are 16-byte interleaved in the OPUC payload area and the 20 OPUC TSOHs are frame interleaved in the OPUC overhead area.
+
+The tributary slot overhead (TSOH) of OPUC tributary slots is located in rows 1 to 3, columns 15 and 16 of the OPUC frame.
+
+The TSOH for a 5G tributary slot is available once every 20 frames. A 20-frame multiframe structure is used for this assignment. This multiframe structure is locked to bits 4, 5, 6, 7 and 8 of the OMFI byte as shown in Table 20-1 and Figure 20-1.
+
+Figure 20-3 presents the 5G tributary slots in the OPUCn for the case of 16-byte interleaving of the OPUC instances. This interleaving presents the tributary slot order within the OPUCn.
+
+| OMFI bits<br>45678 | Row | Column        |        |        |        |         |         |         |          |           |
+|--------------------|-----|---------------|--------|--------|--------|---------|---------|---------|----------|-----------|
+|                    |     | 15~16         | 17~32  | 33~48  | 49~320 | 321~336 | 337~352 | 353~368 | 369~3807 | 3808~3824 |
+| 00000              | 1   | TSOH TS #A.1  | TSA.1  | TSA.2  | ⋮      | TSA.20  | TSA.1   | TSA.2   | ⋮        | TSA.18    |
+|                    | 2   |               | TSA.19 | TSA.20 | ⋮      | TSA.18  | TSA.19  | TSA.20  | ⋮        | TSA.16    |
+|                    | 3   |               | TSA.17 | TSA.18 | ⋮      | TSA.16  | TSA.17  | TSA.18  | ⋮        | TSA.14    |
+|                    | 4   | PSI<br>OMFI   | TSA.15 | TSA.16 | ⋮      | TSA.14  | TSA.15  | TSA.16  | ⋮        | TSA.12    |
+| 00001              | 1   | TSOH TS #A.2  | TSA.13 | TSA.14 | ⋮      | TSA.12  | TSA.13  | TSA.14  | ⋮        | TSA.10    |
+|                    | 2   |               | TSA.11 | TSA.12 | ⋮      | TSA.10  | TSA.11  | TSA.12  | ⋮        | TSA.8     |
+|                    | 3   |               | TSA.9  | TSA.10 | ⋮      | TSA.8   | TSA.9   | TSA.10  | ⋮        | TSA.6     |
+|                    | 4   | PSI<br>OMFI   | TSA.7  | TSA.8  | ⋮      | TSA.6   | TSA.7   | TSA.8   | ⋮        | TSA.4     |
+| 00010              | 1   | TSOH TS #A.3  | TSA.5  | TSA.6  | ⋮      | TSA.4   | TSA.5   | TSA.6   | ⋮        | TSA.2     |
+|                    | 2   |               | TSA.3  | TSA.4  | ⋮      | TSA.2   | TSA.3   | TSA.4   | ⋮        | TSA.20    |
+|                    | 3   |               | TSA.1  | TSA.2  | ⋮      | TSA.20  | TSA.1   | TSA.2   | ⋮        | TSA.18    |
+|                    | 4   | PSI<br>OMFI   | TSA.19 | TSA.20 | ⋮      | TSA.18  | TSA.19  | TSA.20  | ⋮        | TSA.16    |
+| ⋮                  | ⋮   |               |        |        |        |         |         |         |          |           |
+| 10011              | 1   | TSOH TS #A.20 | TSA.9  | TSA.10 | ⋮      | TSA.8   | TSA.9   | TSA.10  | ⋮        | TSA.6     |
+|                    | 2   |               | TSA.7  | TSA.8  | ⋮      | TSA.6   | TSA.7   | TSA.8   | ⋮        | TSA.4     |
+|                    | 3   |               | TSA.5  | TSA.6  | ⋮      | TSA.4   | TSA.5   | TSA.6   | ⋮        | TSA.2     |
+|                    | 4   | PSI<br>OMFI   | TSA.3  | TSA.4  | ⋮      | TSA.2   | TSA.3   | TSA.4   | ⋮        | TSA.20    |
+
+Figure 20-1 – OPUC tributary slot allocation in 80 row x 3810 column format
+
+| Multi-frame Row | Column Frame                      | Frame |      |       |       |        |         |         |         |          |           |       |       |       |       |        |         |         |         |          |           |
+|-----------------|-----------------------------------|-------|------|-------|-------|--------|---------|---------|---------|----------|-----------|-------|-------|-------|-------|--------|---------|---------|---------|----------|-----------|
+|                 |                                   | 15    | 16   | 17-32 | 33-48 | 49-200 | 321-336 | 337-352 | 353-368 | 369-3807 | 3808-3824 | 15    | 16    | 17-32 | 33-48 | 49-200 | 321-336 | 337-352 | 353-368 | 369-3807 | 3808-3824 |
+| 1               | 1,2,<br>3(1 <sup>st</sup> 1/2)    | TS OH | #A1  | TS OH | TS OH | TS OH  | TS OH   | TS OH   | TS OH   | TS OH    | TS OH     | TS OH | TS OH | TS OH | TS OH | TS OH  | TS OH   | TS OH   | TS OH   | TS OH    | TS OH     |
+| 2               | 3(2 <sup>nd</sup> 1/2),<br>4,5    | TS OH | #A3  | TS OH | TS OH | TS OH  | TS OH   | TS OH   | TS OH   | TS OH    | TS OH     | TS OH | TS OH | TS OH | TS OH | TS OH  | TS OH   | TS OH   | TS OH   | TS OH    | TS OH     |
+| 3               | 6,7,<br>8(1 <sup>st</sup> 1/2)    | TS OH | #A6  | TS OH | TS OH | TS OH  | TS OH   | TS OH   | TS OH   | TS OH    | TS OH     | TS OH | TS OH | TS OH | TS OH | TS OH  | TS OH   | TS OH   | TS OH   | TS OH    | TS OH     |
+| 4               | 8(2 <sup>nd</sup> 1/2),<br>9,10   | TS OH | #A8  | TS OH | TS OH | TS OH  | TS OH   | TS OH   | TS OH   | TS OH    | TS OH     | TS OH | TS OH | TS OH | TS OH | TS OH  | TS OH   | TS OH   | TS OH   | TS OH    | TS OH     |
+| 5               | 11,12,<br>13(1 <sup>st</sup> 1/2) | TS OH | #A11 | TS OH | TS OH | TS OH  | TS OH   | TS OH   | TS OH   | TS OH    | TS OH     | TS OH | TS OH | TS OH | TS OH | TS OH  | TS OH   | TS OH   | TS OH   | TS OH    | TS OH     |
+| 6               | 13(2 <sup>nd</sup> 1/2),<br>14,15 | TS OH | #A13 | TS OH | TS OH | TS OH  | TS OH   | TS OH   | TS OH   | TS OH    | TS OH     | TS OH | TS OH | TS OH | TS OH | TS OH  | TS OH   | TS OH   | TS OH   | TS OH    | TS OH     |
+| 7               | 16,17,<br>18(1 <sup>st</sup> 1/2) | TS OH | #A16 | TS OH | TS OH | TS OH  | TS OH   | TS OH   | TS OH   | TS OH    | TS OH     | TS OH | TS OH | TS OH | TS OH | TS OH  | TS OH   | TS OH   | TS OH   | TS OH    | TS OH     |
+| 8               | 18(2 <sup>nd</sup> 1/2),<br>19,20 | TS OH | #A18 | TS OH | TS OH | TS OH  | TS OH   | TS OH   | TS OH   | TS OH    | TS OH     | TS OH | TS OH | TS OH | TS OH | TS OH  | TS OH   | TS OH   | TS OH   | TS OH    | TS OH     |
+
+Figure 20-2 – OPUC tributary slot allocation in 8 row x 38100 column format
+
+| OMFI bits<br>45678 | Row | Column          |        |             |        |        |        |       |        |       |       |        |        |        |        |        |        |       |       |              |        |
+|--------------------|-----|-----------------|--------|-------------|--------|--------|--------|-------|--------|-------|-------|--------|--------|--------|--------|--------|--------|-------|-------|--------------|--------|
+|                    |     | 2 x n           |        | 20 x 16 x n |        |        |        |       |        |       |       |        |        |        |        |        |        |       |       | 218 x 16 x n |        |
+| 00000              | 1   | OPUCn OH (TSOH) |        |             |        |        |        |       |        |       |       |        |        |        |        |        |        |       |       |              |        |
+|                    | 2   | TS1.19          | TS1.17 | TS1.15      | TS1.13 | TS1.11 | TS1.9  | TS1.7 | TS1.5  | TS1.3 | TS1.1 | TS1.19 | TS1.17 | TS1.15 | TS1.13 | TS1.11 | TS1.9  | TS1.7 | TS1.5 | TS1.3        | TS1.1  |
+|                    | 3   | TS2.19          | TS2.17 | TS2.15      | TS2.13 | TS2.11 | TS2.9  | TS2.7 | TS2.5  | TS2.3 | TS2.1 | TS2.19 | TS2.17 | TS2.15 | TS2.13 | TS2.11 | TS2.9  | TS2.7 | TS2.5 | TS2.3        | TS2.1  |
+|                    | 4   | :               | :      | :           | :      | :      | :      | :     | :      | :     | :     | :      | :      | :      | :      | :      | :      | :     | :     | :            | :      |
+| 00001              | 1   | OPUCn OH (TSOH) |        |             |        |        |        |       |        |       |       |        |        |        |        |        |        |       |       |              |        |
+|                    | 2   | TSn.19          | TSn.17 | TSn.15      | TSn.13 | TSn.11 | TSn.9  | TSn.7 | TSn.5  | TSn.3 | TSn.1 | TSn.19 | TSn.17 | TSn.15 | TSn.13 | TSn.11 | TSn.9  | TSn.7 | TSn.5 | TSn.3        | TSn.1  |
+|                    | 3   | TSn.20          | TSn.18 | TSn.16      | TSn.14 | TSn.12 | TSn.10 | TSn.8 | TSn.6  | TSn.4 | TSn.2 | TSn.20 | TSn.18 | TSn.16 | TSn.14 | TSn.12 | TSn.10 | TSn.8 | TSn.6 | TSn.4        | TSn.2  |
+|                    | 4   | :               | :      | :           | :      | :      | :      | :     | :      | :     | :     | :      | :      | :      | :      | :      | :      | :     | :     | :            | :      |
+| 00010              | 1   | OPUCn OH (TSOH) |        |             |        |        |        |       |        |       |       |        |        |        |        |        |        |       |       |              |        |
+|                    | 2   | TS1.19          | TS1.17 | TS1.15      | TS1.13 | TS1.11 | TS1.9  | TS1.7 | TS1.5  | TS1.3 | TS1.1 | TS1.19 | TS1.17 | TS1.15 | TS1.13 | TS1.11 | TS1.9  | TS1.7 | TS1.5 | TS1.3        | TS1.1  |
+|                    | 3   | TS2.19          | TS2.17 | TS2.15      | TS2.13 | TS2.11 | TS2.9  | TS2.7 | TS2.5  | TS2.3 | TS2.1 | TS2.19 | TS2.17 | TS2.15 | TS2.13 | TS2.11 | TS2.9  | TS2.7 | TS2.5 | TS2.3        | TS2.1  |
+|                    | 4   | :               | :      | :           | :      | :      | :      | :     | :      | :     | :     | :      | :      | :      | :      | :      | :      | :     | :     | :            | :      |
+| ⋮                  |     | ⋮               |        |             |        |        |        |       |        |       |       |        |        |        |        |        |        |       |       |              |        |
+| 10011              | 1   | OPUCn OH (TSOH) |        |             |        |        |        |       |        |       |       |        |        |        |        |        |        |       |       |              |        |
+|                    | 2   | TS1.3           | TS1.5  | TS1.7       | TS1.9  | TSn.3  | TSn.5  | TSn.7 | TSn.9  | TSn.3 | TSn.5 | TSn.7  | TSn.9  | TSn.3  | TSn.5  | TSn.7  | TSn.9  | TSn.3 | TSn.5 | TSn.7        | TSn.9  |
+|                    | 3   | TS2.3           | TS2.5  | TS2.7       | TS2.9  | TS1.4  | TS1.6  | TS1.8 | TS1.10 | TS1.4 | TS1.6 | TS1.8  | TS1.10 | TS1.4  | TS1.6  | TS1.8  | TS1.10 | TS1.4 | TS1.6 | TS1.8        | TS1.10 |
+|                    | 4   | :               | :      | :           | :      | :      | :      | :     | :      | :     | :     | :      | :      | :      | :      | :      | :      | :     | :     | :            | :      |
+
+Figure 20-3 – OPUCn tributary slot allocation with n OPUC 16-byte interleaved
+
+**Table 20-1 – OPUCn tributary slot OH allocation**
+
+| OMFI<br>bits<br>4 5 6 7 8 | TSOH<br>5G TS |
+|---------------------------|---------------|
+| 0 0 0 0 0                 | A.1           |
+| 0 0 0 0 1                 | A.2           |
+| 0 0 0 1 0                 | A.3           |
+| 0 0 0 1 1                 | A.4           |
+| 0 0 1 0 0                 | A.5           |
+| 0 0 1 0 1                 | A.6           |
+| 0 0 1 1 0                 | A.7           |
+| 0 0 1 1 1                 | A.8           |
+| 0 1 0 0 0                 | A.9           |
+| 0 1 0 0 1                 | A.10          |
+| 0 1 0 1 0                 | A.11          |
+| 0 1 0 1 1                 | A.12          |
+| 0 1 1 0 0                 | A.13          |
+| 0 1 1 0 1                 | A.14          |
+| 0 1 1 1 0                 | A.15          |
+| 0 1 1 1 1                 | A.16          |
+| 1 0 0 0 0                 | A.17          |
+| 1 0 0 0 1                 | A.18          |
+| 1 0 0 1 0                 | A.19          |
+| 1 0 0 1 1                 | A.20          |
+
+## 20.2 ODTUCn definition
+
+The optical data tributary unit *Cn* (ODTUCn) carries a justified ODUk signal. There is one type of ODTUCn:
+
+- ODTUCn.ts (ts = 1 to 20n) in which a ODUk (k = 0,1,2,2e,3,4,flex) signal is mapped via the generic mapping procedure (GMP) defined in clause 20.5.
+
+### Optical data tributary unit Cn.ts (ODTUCn.ts)
+
+The optical data tributary unit Cn.ts (ODTUCn.ts) is a structure which consists of an ODTUCn.ts payload area and an ODTUCn.ts overhead area (Figure 20-4). The ODTUCn.ts payload area has 119×ts (ts=1 to 20n) 16-byte-columns and 8 rows (15232×ts bytes) and the ODTUCn.ts overhead area has one times 6 bytes. The ODTUCn.ts is carried in "ts" 5G tributary slots of an OPUCn.
+
+The location of the ODTUCn.ts overhead depends on the OPUCn tributary slot used when multiplexing the ODTUCn.ts in the OPUCn (see clause 20.1.1). The single instance of an ODTUCn.ts overhead is located in the OPUCn TSOH of the last OPUCn tributary slot allocated to the ODTUCn.ts.
+
+The ODTUCn.ts overhead carries the GMP justification overhead as specified in clause 20.4.
+
+The ODTUCn.ts overhead carries the GMP justification overhead consisting of 6 bytes of justification control (JC1, JC2, JC3, JC4, JC5, JC6) which carry the GMP C<sub>m</sub> and ΣC<sub>8D</sub> information.
+
+![Figure 20-4: ODTUCn.ts frame formats. The diagram shows a large rectangular frame structure. The top row is labeled 'ODTUCn.ts overhead' and contains columns numbered 1, 2, 3, followed by a series of dots, and then two columns labeled '119 x ts-1'. The left side of the frame has a small inset showing a 2x3 grid. The right side of the frame has rows numbered 1, 2, 3, followed by a series of dots, and then rows 7 and 8. The text 'G.709-Y.1331(16)_F20-4' is at the bottom right.](3f1b6583b85a3ffee7d3341f131a657c_img.jpg)
+
+Figure 20-4: ODTUCn.ts frame formats. The diagram shows a large rectangular frame structure. The top row is labeled 'ODTUCn.ts overhead' and contains columns numbered 1, 2, 3, followed by a series of dots, and then two columns labeled '119 x ts-1'. The left side of the frame has a small inset showing a 2x3 grid. The right side of the frame has rows numbered 1, 2, 3, followed by a series of dots, and then rows 7 and 8. The text 'G.709-Y.1331(16)\_F20-4' is at the bottom right.
+
+Figure 20-4 – ODTUCn.ts frame formats
+
+### 20.3 Multiplexing ODTUCn signals into the OPUCn
+
+Multiplexing an ODTUCn.ts signal into an OPUCn is realized by mapping the ODTUCn.ts signal into ts (of 20n) arbitrary OPUCn 5G tributary slots: OPUCn TS #A1.B1, TS #A2.B2, .. , TS #Ats.Bts with  $1 \leq n*(B_1-1)+A_1 < n*(B_2-1)+A_2 < .. < n*(B_{ts}-1)+A_{ts} \leq 20n$ .
+
+NOTE 1 – TS #A1.B1, TS #A2.B2, ..., TS #Ats.Bts do not have to be sequential in the OPUCn TS sequence; the TSs can be arbitrarily selected to prevent bandwidth fragmentation.
+
+NOTE 2 – TS order is illustrated in Figure 20-5.
+
+![Figure 20-5: OPUCn TS order. This diagram illustrates the mapping of multiple ODTUCn signals into OPUCn tributary slots. It shows a zigzag pattern of arrows connecting tributary slots (TS) for different OPUCn signals. OPUC #1 maps to TS1.1, TS1.2, TS1.3, ..., TS1.20. OPUC #2 maps to TS2.1, TS2.2, TS2.3, ..., TS2.20. OPUC #3 maps to TS3.1, TS3.2, TS3.3, ..., TS3.20. OPUC #n maps to TSn.1, TSn.2, TSn.3, ..., TSn.20. The arrows show the sequential order of slots: TS1.1, TS2.1, TS3.1, ..., TSn.1, then TS1.2, TS2.2, TS3.2, ..., TSn.2, and so on, up to TS1.20, TS2.20, TS3.20, ..., TSn.20. The text 'G.709-Y.1331(16)_F20-5' is at the bottom right.](e2669d6c9c855db64fac0048acd0643b_img.jpg)
+
+Figure 20-5: OPUCn TS order. This diagram illustrates the mapping of multiple ODTUCn signals into OPUCn tributary slots. It shows a zigzag pattern of arrows connecting tributary slots (TS) for different OPUCn signals. OPUC #1 maps to TS1.1, TS1.2, TS1.3, ..., TS1.20. OPUC #2 maps to TS2.1, TS2.2, TS2.3, ..., TS2.20. OPUC #3 maps to TS3.1, TS3.2, TS3.3, ..., TS3.20. OPUC #n maps to TSn.1, TSn.2, TSn.3, ..., TSn.20. The arrows show the sequential order of slots: TS1.1, TS2.1, TS3.1, ..., TSn.1, then TS1.2, TS2.2, TS3.2, ..., TSn.2, and so on, up to TS1.20, TS2.20, TS3.20, ..., TSn.20. The text 'G.709-Y.1331(16)\_F20-5' is at the bottom right.
+
+Figure 20-5 – OPUCn TS order
+
+The OPUCn overhead for these multiplexed signals consists of a payload type (PT), the multiplex structure identifier (MSI), the OPUCn multiframe identifier, the OPUCn tributary slot overhead carrying the ODTUCn overhead and depending on the ODTU type one or more bytes reserved for future international standardization.
+
+#### 20.3.1 ODTUCn.ts mapping into ts OPUCn 5G tributary slots
+
+A 16-byte of the ODTUCn.ts payload signal is mapped into a 16-byte of an OPUCn 5G TS #Ai.Bi (i = 1,..,ts) payload area, as indicated in Figure 20-6.
+
+A byte of the ODTUCn.ts overhead is mapped into a TSOH byte of TS #Ats.Bts within columns 15 and 16, rows 1 to 3 of the last OPUCn 5G tributary slot allocated to the ODTUCn.ts.
+
+The remaining OPUC*n* TSOH bytes are reserved for future international standardization.
+
+![Figure 20-6 – Mapping of ODTUCn.ts into 'ts' OPUCn 5G tributary slots](c8363610940980ea7cd1611443c94ef5_img.jpg)
+
+The diagram illustrates the mapping of ODTUC*n.ts* into 'ts' OPUC*n* 5G tributary slots. At the top, a large grid represents ODTUC*n.ts* with 8 rows and columns indexed from 1 to 119 × ts. Below this, three smaller grids represent individual tributary slots: OPUC*n* TS #A1.B1, OPUC*n* TS #A2.B2, and OPUC*n* TS #Ats.Bts. Each of these smaller grids has 8 rows and 119 columns. Arrows indicate how columns from the large ODTUC*n.ts* grid map into the columns of the individual tributary slots. On the left, vertical labels indicate overhead bytes: JC6, JC5, JC4, JC3, JC2, JC1 for the ODTUC*n.ts* and RES (reserved) bits for the tributary slots. Specific bit patterns (00000, 10011) and OMFI bits (45678) are associated with the OPUC*n* tributary slots.
+
+**ODTUC*n.ts* Grid Structure:**
+
+|           |                                       |   |   |     |    |     |     |          |
+|-----------|---------------------------------------|---|---|-----|----|-----|-----|----------|
+| Row \ Col | 1                                     | 2 | 3 | ... | ts | ... | ... | 119 × ts |
+| 1-8       | Data bytes mapping to tributary slots |   |   |     |    |     |     |          |
+
+**OPUC*n* Tributary Slot Grid (e.g., TS #A1.B1):**
+
+|           |            |   |     |     |
+|-----------|------------|---|-----|-----|
+| Row \ Col | 1          | 2 | ... | 119 |
+| 1-8       | Data bytes |   |     |     |
+
+Reference: G.709-Y.1331(16)-Amd.2(18)\_F20-6
+
+Figure 20-6 – Mapping of ODTUCn.ts into 'ts' OPUCn 5G tributary slots
+
+**Figure 20-6 – Mapping of ODTUC*n.ts* into 'ts' OPUC*n* 5G tributary slots**
+
+## 20.4 OPUC*n* multiplex overhead and ODTU justification overhead
+
+The OPUC*n* multiplex overhead consists of a multiplex structure identifier (MSI), an OPU multiframe identifier (OMFI), an ODTU overhead and bytes reserved for future international standardization.
+
+The OPUC*n* MSI, OMFI and RES overhead locations are shown in Figure 20-7.
+
+### ODTUC*n.ts* overhead
+
+The ODTUC*n.ts* overhead carries the GMP justification overhead consisting of 18 bits of justification control (JC1[3-8], JC2[3-8], JC3[3-8]) which carry the 10-bit GMP  $C_m$  information and ODU $k$  ( $k=0,1,2,2e,3,4,flex$ ) specific 30 bits of justification control (JC1[1-2], JC2[1-2], JC3[1-2], JC4, JC5, JC6) which carry the 18-bit GMP  $\sum C_{8D}$  information.
+
+The JC1, JC2, JC3, JC4, JC5 and JC6 overhead locations are shown in Figure 20-7.
+
+![Figure 20-7: OPUcn multiplex overhead (payload type = 22). The diagram shows the structure of the OPU overhead across multiple rows and columns. Row 1 contains JC4, JC1, and the start of the OPU payload. Row 2 contains JC5, JC2. Row 3 contains JC6, JC3. Row 4 contains PSI and OMFI. Rows 0, 1, 2, 41, 42, and 255 contain PT=22, Reserved, MSI, and Reserved fields. The OMFI field is expanded to show bits 0-8, with bits 0-2 being 0, and bits 3-8 being MSB to LSB. The JC1 field is expanded to show bits 1-8, with bits 1-6 being a 10-bit Cm (m=128xM), bit 7 being a decrement indicator, and bit 8 being an increment indicator. The JC2 field is expanded to show bits 1-8, with bits 1-6 being a 10-bit Cm (m=128xM), bit 7 being a decrement indicator, and bit 8 being an increment indicator. The JC3 field is expanded to show bits 1-8, with bits 1-6 being a 10-bit Cm (m=128xM), bit 7 being a decrement indicator, and bit 8 being an increment indicator. The JC4 field is expanded to show bits 1-8, with bits 1-6 being a 10-bit Cm (m=128xM), bit 7 being a decrement indicator, and bit 8 being an increment indicator. The JC5 field is expanded to show bits 1-8, with bits 1-6 being a 10-bit Cm (m=128xM), bit 7 being a decrement indicator, and bit 8 being an increment indicator. The JC6 field is expanded to show bits 1-8, with bits 1-6 being a 10-bit Cm (m=128xM), bit 7 being a decrement indicator, and bit 8 being an increment indicator. The Client specific 18-bit ΣC81 field is also shown.](3af2fc22afa44863b4fdcb07aa719bc9_img.jpg)
+
+Figure 20-7: OPUcn multiplex overhead (payload type = 22). The diagram shows the structure of the OPU overhead across multiple rows and columns. Row 1 contains JC4, JC1, and the start of the OPU payload. Row 2 contains JC5, JC2. Row 3 contains JC6, JC3. Row 4 contains PSI and OMFI. Rows 0, 1, 2, 41, 42, and 255 contain PT=22, Reserved, MSI, and Reserved fields. The OMFI field is expanded to show bits 0-8, with bits 0-2 being 0, and bits 3-8 being MSB to LSB. The JC1 field is expanded to show bits 1-8, with bits 1-6 being a 10-bit Cm (m=128xM), bit 7 being a decrement indicator, and bit 8 being an increment indicator. The JC2 field is expanded to show bits 1-8, with bits 1-6 being a 10-bit Cm (m=128xM), bit 7 being a decrement indicator, and bit 8 being an increment indicator. The JC3 field is expanded to show bits 1-8, with bits 1-6 being a 10-bit Cm (m=128xM), bit 7 being a decrement indicator, and bit 8 being an increment indicator. The JC4 field is expanded to show bits 1-8, with bits 1-6 being a 10-bit Cm (m=128xM), bit 7 being a decrement indicator, and bit 8 being an increment indicator. The JC5 field is expanded to show bits 1-8, with bits 1-6 being a 10-bit Cm (m=128xM), bit 7 being a decrement indicator, and bit 8 being an increment indicator. The JC6 field is expanded to show bits 1-8, with bits 1-6 being a 10-bit Cm (m=128xM), bit 7 being a decrement indicator, and bit 8 being an increment indicator. The Client specific 18-bit ΣC81 field is also shown.
+
+G.709-Y.1331(16)-Amd.3(19)\_F20-7
+
+Figure 20-7 – OPUcn multiplex overhead (payload type = 22)
+
+### 20.4.1 OPUcn multiplex structure identifier (MSI)
+
+The OPUcn multiplex structure identifier (MSI) overhead, which encodes the ODU multiplex structure in the OPU, is located in the mapping specific area of the PSI signal (refer to Figure 20-7 for the MSI location in OPUcn with PT=22). The MSI has a fixed length of 40n bytes and indicates the ODTU content of each tributary slot (TS) of an OPUcn. Two bytes are used for each TS.
+
+#### 20.4.1.1 OPUcn multiplex structure identifier (MSI) – Payload type 22
+
+For the 20n OPUcn 5G tributary slots n times 40 bytes of the PSI are used (named PSI[x,y] where x = 1...n and y = 2...41, that is PSI[1,2], PSI[1,3],...PSI[1,41], PSI[2,2], PSI[2,3],..., PSI[2,41], PSI[3,2],...,PSI[n-1,41], PSI[n,2],..., PSI[n,41]) as MSI bytes as shown in Figure 20-7. The MSI indicates the ODTU content of each tributary slot of an OPU. Two bytes are used for each tributary slot as illustrated in Figure 20-8 and the encoding of the fields of each MSI instance is illustrated in Figure 20-9.
+
+- The TS availability bit 1 indicates if the tributary slot is available or unavailable.
+- The TS occupation bit 9 indicates if the tributary slot is allocated or unallocated.
+- The tributary port # in bits 2 to 8 and 10 to 16 indicates the port number of the ODTUCn.ts that is being transported in this TS; a flexible assignment of tributary port to tributary slots is possible. ODTUCn.ts tributary ports are numbered 1 to 10n. The value is set to all-0s when the occupation bit has the value 0 (tributary slot is unallocated).
+
+![](3100b9f8708f586e472f3d9e44f10e52_img.jpg)
+
+|           | 1            | 2                | 3 | 4 | 5 | 6 | 7 | 8 | 5G TS    |
+|-----------|--------------|------------------|---|---|---|---|---|---|----------|
+| PSI[A.2]  | Availability | Tributary port # |   |   |   |   |   |   | TS #A.1  |
+| PSI[A.3]  | Occupation   |                  |   |   |   |   |   |   |          |
+| PSI[A.4]  | Availability | Tributary port # |   |   |   |   |   |   | TS #A.2  |
+| PSI[A.5]  | Occupation   |                  |   |   |   |   |   |   |          |
+| PSI[A.6]  | Availability | Tributary port # |   |   |   |   |   |   | TS #A.3  |
+| PSI[A.7]  | Occupation   |                  |   |   |   |   |   |   |          |
+| ⋮         |              | ⋮                |   |   |   |   |   |   | ⋮        |
+| PSI[A.40] | Availability | Tributary port # |   |   |   |   |   |   | TS #A.20 |
+| PSI[A.41] | Occupation   |                  |   |   |   |   |   |   |          |
+
+G.709-Y.1331(16)\_F20-8
+
+NOTE –  $A = 1 \dots n$
+
+**Figure 20-8 – OPUCn 5G TS MSI coding – Payload type 22**
+
+![](d33f50868e9cfda1b1206833c4061e12_img.jpg)
+
+|             | 1            | 2   | 3                | 4 | 5 | 6 | 7 | 8   | 5G TS   |
+|-------------|--------------|-----|------------------|---|---|---|---|-----|---------|
+| PSI[A.2B]   | Availability | MSB | ⋮                |   |   |   |   |     | TS #A.B |
+| PSI[A.2B+1] | Occupation   |     | Tributary port # |   |   |   |   |     |         |
+|             |              |     |                  |   |   |   |   | LSB |         |
+
+0 : Unavailable      00 0000 0000 0000 : Tributary port #1  
+ 1 : Available        00 0000 0000 0001 : Tributary port #2  
+                           00 0000 0000 0010 : Tributary port #3  
+                           00 0000 0000 0011 : Tributary port #4  
+                           ⋮  
+                           xx xxxx xxxx xxxx : Tributary port #10n
+
+G.709-Y.1331(16)\_F20-9
+
+NOTE –  $A = 1 \dots n, B = 1 \dots 20$
+
+**Figure 20-9 – OPUCn MSI coding – Payload type 22**
+
+## 20.4.2 OPUCn payload structure identifier reserved overhead (RES)
+
+$216 \cdot n - 1$  (OPUCn) bytes are reserved in the OPUCn PSI for future international standardization. These bytes are located in PSI[x.1] and PSI[x.42] to PSI[x.255] of the OPUCn overhead where  $x = 1 \dots n$  and PSI[x.0],  $x=2$  to  $n$ . These bytes are set to all-0s.
+
+## 20.4.3 OPUCn multiplex justification overhead (JOH)
+
+The generic mapping procedure (GMP) is used for the mapping of an ODUk into ODTUCn.ts. GMP uses ODUk and OPUCn independent stuff and justification opportunity definitions (ODTUCn.ts). Stuff locations within an ODTUCn.ts are determined by means of a formula which is specified in clause 20.4.3.1.
+
+### 20.4.3.1 Generic mapping procedure (GMP)
+
+The justification overhead (JOH) for the generic mapping procedure consists of two groups of three bytes of justification control; JC1, JC2, JC3 and JC4, JC5, JC6. Refer to Figure 20-7.
+
+The bits 3 to 8 of the JC1, JC2 and JC3 bytes consist of a 10-bit  $C_m$  field (bits  $C_1, C_2, \dots, C_{10}$ ), a 1-bit increment indicator (II) field, a 1-bit decrement indicator (DI) field and a 6-bit CRC-6 field which contains an error check code over the JC1, JC2 and JC3 bits 3 to 8 fields.
+
+The bits 1 and 2 of the JC1, JC2, JC3 bytes and bits 2 to 8 of the JC4, JC5 and JC6 bytes consist of a 18-bit  $\sum C_{nD}$  field (bits  $D_1, D_2, \dots, D_{18}$ ), a 9-bit CRC-9 field which contains an error check code over
+
+bits 2 to 8 in the JC4, JC5 and JC6 fields plus bits 1 and 2 in the JC1, JC2 and JC3 fields and three reserved bits.
+
+The value of 'm' in  $C_m$  is  $128 \times ts'$  (number of tributary slots occupied by the ODTUCn.ts).
+
+The value of 'n' represents the timing granularity of the GMP  $C_n$  parameter, which is also present in  $\Sigma C_{nD}$ . The value of n is 8.
+
+The value of  $C_m$  controls the distribution of groups of '16ts' ODUk data bytes into groups of '16ts' ODTUCn.ts payload bytes. Refer to clause 20.5 and Annex D for further specification of this process.
+
+The value of  $\Sigma C_{nD}$  provides additional 'n'-bit timing information, which is necessary to control the jitter and wander performance experienced by the ODUk signal.
+
+The value of  $C_n$  (i.e., number of client n-bit data entities per OPUCn multiframe) is computed as follows:  $C_n(t) = m \times C_m(t) + (\Sigma C_{nD}(t) - \Sigma C_{nD}(t-1))$ . Note that the value  $C_{nD}$  is effectively an indication of the amount of data in the mapper's virtual queue that it could not send during that multiframe due to it being less than a 16M-byte word. For the case where the value of  $\Sigma C_{nD}$  in a multiframe 't' is corrupted, it is possible to recover from such error in the next multiframe 't+1'.
+
+#### 20.4.4 OPUCn multiframe identifier overhead (OMFI)
+
+An OPUCn multiframe identifier (OMFI) byte is defined in row 4, column 16 of the OPUC #1 to #n overhead (Figure 20-10). The value of bits 4 to 8 of the OMFI byte will be incremented each OPUCn frame to provide a 20 frame multiframe for the multiplexing of ODUk signals into the OPUCn.
+
+NOTE 1 – It is an option to align the OMFI = 0 position with MFAS = 0 position every 1280 (the least common multiple of 20 and 256) frame periods.
+
+NOTE 2 – OMFI must be copied in all n OPUC instances at the source, and only 1 need to be processed at the sink.
+
+| OMFI OH byte |   |   |   |   |   |   |   |   |
+|--------------|---|---|---|---|---|---|---|---|
+|              | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
+| Fixed to 0   | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
+| Fixed to 0   | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
+| Fixed to 0   | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 0 |
+|              | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 |
+|              | 0 | 0 | 0 | 0 | 1 | 0 | 0 | 0 |
+|              | 0 | 0 | 0 | 0 | 1 | 0 | 1 | 0 |
+|              | 0 | 0 | 0 | 0 | 1 | 1 | 0 | 0 |
+|              | 0 | 0 | 0 | 0 | 1 | 1 | 1 | 0 |
+|              | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 0 |
+|              | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 1 |
+|              | 0 | 1 | 0 | 0 | 0 | 0 | 1 | 0 |
+|              | 0 | 1 | 0 | 0 | 0 | 0 | 1 | 1 |
+|              | 0 | 1 | 0 | 0 | 0 | 1 | 0 | 0 |
+|              | 0 | 1 | 0 | 0 | 0 | 1 | 0 | 1 |
+|              | 0 | 1 | 0 | 0 | 0 | 1 | 1 | 0 |
+|              | 0 | 1 | 0 | 0 | 0 | 1 | 1 | 1 |
+|              | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
+|              | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
+|              | 1 | 0 | 0 | 0 | 0 | 0 | 1 | 0 |
+|              | 1 | 0 | 0 | 0 | 0 | 0 | 1 | 1 |
+|              | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
+|              | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
+
+G.709-Y.1331(20)\_F20-10
+
+Figure 20-10 – OPUCn multiframe identifier (OMFI) overhead
+
+## 20.5 Mapping ODUk into ODTUCn.ts
+
+The mapping of ODUk (k = 0, 1, 2, 2e, 3, 4, flex) signals (with up to  $\pm 100$  ppm bit-rate tolerance) into the ODTUCn.ts (ts = M) signal is performed by means of a generic mapping procedure as specified in Annex D.
+
+The OPUcn and therefore the ODTUCn.ts signals are created from a locally generated clock (within the limits specified in Table 7-3), which is independent of the ODUk signal.
+
+The ODUk signal is extended with a frame alignment overhead as specified in clauses 15.6.2.1 and 15.6.2.2 and an all-0s pattern in the OTUk overhead field (see Figure 19-30, read "j" by "k").
+
+The extended ODUk signal is adapted to the locally generated OPUcn/ODTUCn.ts clock by means of a generic mapping procedure (GMP) as specified in Annex D. The value of n in cn and Cn(t) and CnD(t) is specified in Annex D. The value of M is the number of tributary slots occupied by the ODUk; ODTUCn.ts = ODTUCn.M.
+
+A group of M successive extended ODUk 16-byte (128-bit) words is mapped into a group of M successive ODTUCn.M 16-byte (128-bit) words.
+
+NOTE 1 – The 16-byte word alignment of the extended ODUk is preserved through the mapping procedure; e.g., the position of the first 16 OH bytes of the ODUk is always located after an integer number of 16-byte words from the start of the ODTUCn.M structure.
+
+The generic mapping process generates for the case of ODUk signals once per ODTUCn.M multiframe the Cm(t) and CnD(t) information according to Annex D and encodes this information in the ODTUCn.ts justification control overhead JC1/JC2/JC3 and JC4/JC5/JC6. The de-mapping process decodes Cm(t) and CnD(t) from JC1/JC2/JC3 and JC4/JC5/JC6 and interprets Cm(t) and CnD(t) according to Annex D. CRC-6 shall be used to protect against an error in bits 3 to 8 of the JC1, JC2, JC3 signals. CRC-9 shall be used to protect against an error in bits 1 and 2 of JC1, JC2, JC3 and bits 2 to 8 of JC4, JC5, JC6 signals.
+
+During a signal fail condition of the incoming ODUk signal, this failed incoming signal will contain the ODUk-AIS signal as specified in clause 16.5.1. This ODUk-AIS is then mapped into the ODTUCn.M.
+
+For the case where the ODUk is received from the output of a fabric (ODU connection function), the incoming signal may contain (in the case of an open matrix connection) the ODUk-OCI signal as specified in clause 16.5.2. This ODUk-OCI signal is then mapped into the ODTUCn.M.
+
+NOTE 2 – Not all equipment will have a real connection function (i.e., switch fabric) implemented; instead, the presence/absence of tributary interface port units represents the presence/absence of a matrix connection. If such a unit is intentionally absent (i.e., not installed), the associated ODTUCn.M signals should carry an ODUk-OCI signal. If such a unit is installed but temporarily removed as part of a repair action, the associated ODTUCn.M signal should carry an ODUk-AIS signal.
+
+A group of M successive extended ODUk 16-byte words is de-mapped from a group of M successive ODTUCn.M 16-byte blocks.
+
+NOTE 3 – For the case where the ODUk signal is output as an OTUk signal, frame alignment of the extracted extended ODUk signal is to be recovered to allow frame synchronous mapping of the ODUk into the OTUk signal.
+
+During a signal fail condition of the incoming ODUcn/OPUcn signal (e.g., in the case of an ODUcn-AIS condition) the ODUk-AIS pattern as specified in clause 16.5.1 is generated as a replacement signal for the lost ODUk signal.
+
+The values of M, m, Cm,min, Cm,max, n, Cn,min and Cn,max for ODUk into ODTUCn.ts are as follows:
+
+$$M = \text{ceiling} \left( \frac{\text{ODUk\_nom\_bit\_rate} \times (1 + \text{ODUk\_bit\_rate\_tolerance} + 0.00006)}{\text{ODTUCn.1\_nom\_bit\_rate} \times (1 - \text{ODTUCnts\_bit\_rate\_tolerance})} \right) \text{ for ODUk with } k \neq \text{flex(GFP,n,k')} \quad (20-1a)$$
+
+$$M = \text{ceiling} \left( \frac{ODUk\_nom\_bit\_rate}{ODUk.ts \times 4} \right) = \text{ceiling}(n/4) \text{ for ODUk with } k = \text{flex}(\text{GFP}, n, k') \text{ and } k' \in \{2, 3, 4\} \quad (20-1b)$$
+
+$$m = 128 \times M \quad (20-2)$$
+
+$$c_{m,nom} = \left( \frac{ODUk\_nom\_bit\_rate \times \text{Number\_of\_GMP\_blocks\_in\_ODTUCn.ts}}{ODTUCn.1\_nom\_bit\_rate \times M} \right) \quad (20-3)$$
+
+$$c_{m,min} = c_{m,nom} \times \left( \frac{1 - ODUk\_bit\_rate\_tolerance}{1 + ODTUCn.1\_bit\_rate\_tolerance} \right) \quad (20-4)$$
+
+$$c_{m,max} = c_{m,nom} \times \left( \frac{1 + ODUk\_bit\_rate\_tolerance}{1 - ODTUCn.1\_bit\_rate\_tolerance} \right) \quad (20-5)$$
+
+$$C_{m,min} = \text{floor}(c_{m,min}) \quad (20-6)$$
+
+$$C_{m,max} = \text{ceiling}(c_{m,max}) \quad (20-7)$$
+
+$$n = 8 \quad (20-8)$$
+
+$$c_{n,nom} = \left( \frac{ODUk\_nom\_bit\_rate \times \text{Number\_of\_GMP\_blocks\_in\_ODTUCn.ts} \times 16}{ODTUCn.1\_nom\_bit\_rate} \right) \quad (20-9)$$
+
+$$c_{n,min} = c_{n,nom} \times \left( \frac{1 - ODUk\_bit\_rate\_tolerance}{1 + ODTUCn.1\_bit\_rate\_tolerance} \right) \quad (20-10)$$
+
+$$c_{n,max} = c_{n,nom} \times \left( \frac{1 + ODUk\_bit\_rate\_tolerance}{1 - ODTUCn.1\_bit\_rate\_tolerance} \right) \quad (20-11)$$
+
+$$C_{n,min} = \text{floor}(c_{n,min}) \quad (20-12)$$
+
+$$C_{n,max} = \text{ceiling}(c_{n,max}) \quad (20-13)$$
+
+$C_{m,min}$ ,  $C_{n,min}$  ( $n=8$ ),  $C_{m,max}$  and  $C_{n,max}$  ( $n=8$ ) values represent the boundaries of ODUk/ODTUCn.M ppm offset combinations (i.e., min. ODUk/max. ODTUCn.M and max. ODUk/min. ODTUCn.M). In steady state, given instances of ODUk/ODTUCn.M offset combinations should not result in generated  $C_n$  and  $C_m$  values throughout this range but rather should be within as small a range as possible.
+
+NOTE – Under transient ppm offset conditions (e.g., AIS to normal signal), it is possible that  $C_n$  and  $C_m$  values outside the range  $C_{n,min}$  to  $C_{n,max}$  and  $C_{m,min}$  to  $C_{m,max}$  may be generated and a GMP de-mapper should be tolerant of such occurrences. Refer to Annex D for a general description of the GMP principles.
+
+### 20.5.1 Mapping ODUk into ODTUCn.M
+
+Groups of M successive 16-byte words of the extended ODUk ( $k = 0, 1, 2, 2e, 3, 4, \text{flex}$ ) signal are mapped into a group of M successive 16-byte blocks of the ODTUCn.M payload area under control of the GMP data/stuff control mechanism. Each group of M 16-byte blocks in the ODTUCn.M payload area may either carry M ODUk 16-byte words, or carry M stuff 16-byte words. The value of the stuff bytes is set to all-0s.
+
+The groups of M 16-byte blocks in the ODTUCn.M payload area are numbered from 1 to 952.
+
+The ODTUCn.M payload 16-byte numbering for GMP M 16-byte (m-bit) blocks is illustrated in Figure 20-11. In row 1 of the ODTUCn.M multiframe the first M 16-byte blocks will be labeled 1, the next M 16-byte blocks will be labeled 2, etc.
+
+| <i>I</i> |     | <i>M</i> | <i>M+1</i> |  | <i>2M</i> | ..... | <i>118*M+1</i> |  | <i>119*M</i> |          |
+|----------|-----|----------|------------|--|-----------|-------|----------------|--|--------------|----------|
+|          |     | 1        | 2          |  | 2         |       | 119            |  | 119          | <i>1</i> |
+|          |     | 120      | 121        |  | 121       |       | 238            |  | 238          | <i>2</i> |
+| JC4      | JC1 | 239      | 240        |  | 240       |       | 357            |  | 357          | <i>3</i> |
+| JC5      | JC2 | 358      | 359        |  | 359       |       | 476            |  | 476          | <i>4</i> |
+| JC6      | JC3 | 477      | 478        |  | 478       |       | 595            |  | 595          | <i>5</i> |
+|          |     | 596      | 597        |  | 597       |       | 714            |  | 714          | <i>6</i> |
+|          |     | 715      | 716        |  | 716       |       | 833            |  | 833          | <i>7</i> |
+|          |     | 834      | 835        |  | 835       |       | 952            |  | 952          | <i>8</i> |
+
+G.709-Y.1331(16)-Amd.1\_F20-11
+
+**Figure 20-11 – ODTUCn.M GMP 16-byte block numbering**
+
+## Annex A
+
+### Forward error correction using 16-byte interleaved RS(255,239) codecs
+
+(This annex forms an integral part of this Recommendation.)
+
+The forward error correction for the OTU-k uses 16-byte interleaved codecs using a Reed-Solomon RS(255,239) code. The RS(255,239) code is a non-binary code (the FEC algorithm operates on byte symbols) and belongs to the family of systematic linear cyclic block codes.
+
+For FEC processing, an OTU row is separated into 16 sub-rows using byte-interleaving as shown in Figure A.1. Each FEC encoder/decoder processes one of these sub-rows. The FEC parity check bytes are calculated over the information bytes 1 to 239 of each sub-row and transmitted in bytes 240 to 255 of the same sub-row.
+
+![Diagram illustrating the byte interleaving process for FEC sub-rows. It shows how bytes from an OTU row are distributed into 16 FEC sub-rows (sub-row #1 to #16). Each sub-row contains information bytes and parity check bytes. Arrows indicate the mapping of bytes from the OTU row to the sub-rows.](e33485d4301404e5a43a61e4cfb96fcc_img.jpg)
+
+The diagram shows the byte interleaving process for FEC sub-rows. At the bottom, an 'OTU row' is shown with 'Information bytes' (bytes 1, 2, ..., 6) and 'Parity check bytes' (bytes 3, 4, 5, 6, 7, 8, 9, 10, ...). Above it, three FEC sub-rows are shown: 'FEC sub-row #1', 'FEC sub-row #2', and 'FEC sub-row #16'. Each sub-row has its own 'Information bytes' and 'Parity check bytes' sections. Arrows indicate the mapping of bytes from the OTU row to the sub-rows. For example, byte 1 of the OTU row maps to the first information byte of FEC sub-row #1, byte 2 maps to the first information byte of FEC sub-row #2, and so on. The parity check bytes in each sub-row are calculated over the information bytes of that sub-row.
+
+Diagram illustrating the byte interleaving process for FEC sub-rows. It shows how bytes from an OTU row are distributed into 16 FEC sub-rows (sub-row #1 to #16). Each sub-row contains information bytes and parity check bytes. Arrows indicate the mapping of bytes from the OTU row to the sub-rows.
+
+G.709/Y.1331\_FA.1
+
+Figure A.1 – FEC sub-rows
+
+The bytes in an OTU row belonging to FEC sub-row X are defined by:  $X + 16 \times (i - 1)$  (for  $i = 1 \dots 255$ ).
+
+The generator polynomial of the code is given by:
+
+$$G(z) = \prod_{i=0}^{15} (z - \alpha^i)$$
+
+where  $\alpha$  is a root of the binary primitive polynomial  $x^8 + x^4 + x^3 + x^2 + 1$ .
+
+The FEC code word (see Figure A.2) consists of information bytes and parity bytes (FEC redundancy) and is represented by the polynomial:
+
+$$C(z) = I(z) + R(z)$$
+
+![Diagram of an FEC code word structure. It shows a sequence of bytes in an FEC sub-row, indexed from 1 to 255. The sequence includes information bytes D_j and parity bytes R_j. Two bytes, D_j and R_j, are expanded to show their 8-bit internal structure: D_j = d_{7j} d_{6j} d_{5j} d_{4j} d_{3j} d_{2j} d_{1j} d_{0j} and R_j = r_{7j} r_{6j} r_{5j} r_{4j} r_{3j} r_{2j} r_{1j} r_{0j}. The diagram is labeled G.709/Y.1331_FA.2.](29aa6165ccf449dee0b4335676fa7b1a_img.jpg)
+
+Transmission order within FEC code word →
+
+G.709/Y.1331\_FA.2
+
+Diagram of an FEC code word structure. It shows a sequence of bytes in an FEC sub-row, indexed from 1 to 255. The sequence includes information bytes D\_j and parity bytes R\_j. Two bytes, D\_j and R\_j, are expanded to show their 8-bit internal structure: D\_j = d\_{7j} d\_{6j} d\_{5j} d\_{4j} d\_{3j} d\_{2j} d\_{1j} d\_{0j} and R\_j = r\_{7j} r\_{6j} r\_{5j} r\_{4j} r\_{3j} r\_{2j} r\_{1j} r\_{0j}. The diagram is labeled G.709/Y.1331\_FA.2.
+
+**Figure A.2 – FEC code word**
+
+Information bytes are represented by:
+
+$$I(z) = D_{254} \cdot z^{254} + D_{253} \cdot z^{253} + \dots + D_{16} \cdot z^{16}$$
+
+Where  $D_j$  ( $j = 16$  to  $254$ ) is the information byte represented by an element out of GF(256) and:
+
+$$D_j = d_{7j} \cdot \alpha^7 + d_{6j} \cdot \alpha^6 + \dots + d_{1j} \cdot \alpha^1 + d_{0j}$$
+
+Bit  $d_{7j}$  is the MSB and  $d_{0j}$  the LSB of the information byte.
+
+$D_{254}$  corresponds to byte 1 in the FEC sub-row and  $D_{16}$  to byte 239.
+
+Parity bytes are represented by:
+
+$$R(z) = R_{15} \cdot z^{15} + R_{14} \cdot z^{14} + \dots + R_1 \cdot z^1 + R_0$$
+
+Where  $R_j$  ( $j = 0$  to  $15$ ) is the parity byte represented by an element out of GF(256) and:
+
+$$R_j = r_{7j} \cdot \alpha^7 + r_{6j} \cdot \alpha^6 + \dots + r_{1j} \cdot \alpha^1 + r_{0j}$$
+
+Bit  $r_{7j}$  is the MSB and  $r_{0j}$  the LSB of the parity byte.
+
+$R_{15}$  corresponds to the byte 240 in the FEC sub-row and  $R_0$  to byte 255.
+
+$R(z)$  is calculated by:
+
+$$R(z) = I(z) \bmod G(z)$$
+
+where "mod" is the modulo calculation over the code generator polynomial  $G(z)$  with elements out of the GF(256). Each element in GF(256) is defined by the binary primitive polynomial
+
+$$x^8 + x^4 + x^3 + x^2 + 1.$$
+
+The Hamming distance of the RS(255,239) code is  $d_{min} = 17$ . The code can correct up to 8 symbol errors in the FEC code word when it is used for error correction. The FEC can detect up to 16 symbol errors in the FEC code word when it is used for error detection capability only.
+
+## Annex B
+
+### Adapting 64B/66B encoded clients via transcoding into 513B code blocks
+
+(This annex forms an integral part of this Recommendation.)
+
+Clients using 64B/66B coding can be adapted in a codeword and timing transparent mapping via transcoding into 513B code blocks to reduce the bit rate that is required to transport the signal. The resulting 513B blocks can be mapped in one of several ways depending on the requirements of the client and the available bandwidth of the container into which the client is mapped. This mapping can be applied to serial or parallel client interfaces.
+
+#### B.1 Transmission order
+
+The order of transmission of information in all the diagrams in this annex is first from left to right and then from top to bottom.
+
+#### B.2 Client frame recovery
+
+For 40GBASE-R and 100GBASE-R clients, framing recovery consists of the recovering 64B/66B block lock per the state diagram in Figure 82-10 of [IEEE 802.3]. For other 64B/66B encoded clients, block lock is achieved as per the state diagram in Figure 49-12 of [IEEE 802.3]. Descrambling is performed as per the process shown in Figure 49-10 of [IEEE 802.3].
+
+Each 66B codeword (after block lock) is one of the following:
+
+- a set of eight data bytes with a sync header of "01";
+- a control block (possibly including seven or fewer data octets) beginning with a sync header of "10".
+
+The 64 bits following the sync header are scrambled as a continuous bit-stream (skipping sync headers and PCS lane markers) according to the polynomial  $G(x) = 1 + x^{39} + x^{58}$ . The 64B/66B PCS receive process will descramble the bits other than (1) the sync header of 66B data and control blocks, and (2) the PCS lane markers.
+
+Figure B.1 illustrates the ordering of 64B/66B code blocks after the completion of the recovering process for an interface.
+
+![Diagram showing the transmission order of 64B/66B code blocks. A vertical arrow labeled 'Transmission order' points down to a stack of blocks. The stack contains blocks labeled '66B blocks' at positions 1, 2, 3, and x, with vertical ellipses between 3 and x. Below the stack, a horizontal line with an arrow pointing right is labeled 'Transmission order', with '1.....66' above it. The diagram is labeled G.709-Y.1331(20)_FB.1.](23d3bda7518a58981e82512f6f813765_img.jpg)
+
+Transmission order
+
+↓
+
+|   |            |
+|---|------------|
+| 1 | 66B blocks |
+| 2 | 66B blocks |
+| 3 | 66B blocks |
+| : | :          |
+| x | 66B blocks |
+
+1.....66 → Transmission order
+
+G.709-Y.1331(20)\_FB.1
+
+Diagram showing the transmission order of 64B/66B code blocks. A vertical arrow labeled 'Transmission order' points down to a stack of blocks. The stack contains blocks labeled '66B blocks' at positions 1, 2, 3, and x, with vertical ellipses between 3 and x. Below the stack, a horizontal line with an arrow pointing right is labeled 'Transmission order', with '1.....66' above it. The diagram is labeled G.709-Y.1331(20)\_FB.1.
+
+Figure B.1 – Stream of 64B/66B code blocks for transcoding
+
+### **B.3 Transcoding from 66B blocks to 513B blocks**
+
+The transcoding process at the encoder operates on an input sequence of 66B code blocks.
+
+66B control blocks (after descrambling) follow the format shown in Figure B.2.
+
+A group of eight 66B blocks is encoded into a single 513B block. The format is illustrated in Figure B.3.
+
+| Input Data                                                                                                              | S<br>Y<br>N<br>C        | Block Payload    |                |   |   |   |   |   |   |   |                |    |    |    |    |    |    |                |                |    |    |    |    |    |                |                |                |    |    |    |    |                |                |                |                |    |    |    |                |                |                |                |                |    |    |                |                |                |                |                |                |    |                |                |                |                |                |                |                |                |                |                |                |                |                | 4-bit code     |      |      |      |      |      |      |      |      |
+|-------------------------------------------------------------------------------------------------------------------------|-------------------------|------------------|----------------|---|---|---|---|---|---|---|----------------|----|----|----|----|----|----|----------------|----------------|----|----|----|----|----|----------------|----------------|----------------|----|----|----|----|----------------|----------------|----------------|----------------|----|----|----|----------------|----------------|----------------|----------------|----------------|----|----|----------------|----------------|----------------|----------------|----------------|----------------|----|----------------|----------------|----------------|----------------|----------------|----------------|----------------|----------------|----------------|----------------|----------------|----------------|----------------|----------------|------|------|------|------|------|------|------|------|
+|                                                                                                                         |                         | Block type field |                |   |   |   |   |   |   |   |                |    |    |    |    |    |    |                |                |    |    |    |    |    |                |                |                |    |    |    |    |                |                |                |                |    |    |    |                |                |                |                |                |    |    |                |                |                |                |                |                |    |                |                |                |                |                |                |                |                |                |                |                |                |                |                |      |      |      |      |      |      |      |      |
+| Data Block Format                                                                                                       | Bit Position            | 0                | 1              | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9              | 10 | 11 | 12 | 13 | 14 | 15 | 16             | 17             | 18 | 19 | 20 | 21 | 22 | 23             | 24             | 25             | 26 | 27 | 28 | 29 | 30             | 31             | 32             | 33             | 34 | 35 | 36 | 37             | 38             | 39             | 40             | 41             | 42 | 43 | 44             | 45             | 46             | 47             | 48             | 49             | 50 | 51             | 52             | 53             | 54             | 55             | 56             | 57             | 58             | 59             | 60             | 61             | 62             | 63             |                | 64   | 65   |      |      |      |      |      |      |
+| D <sub>0</sub> D <sub>1</sub> D <sub>2</sub> D <sub>3</sub> D <sub>4</sub> D <sub>5</sub> D <sub>6</sub> D <sub>7</sub> | 0                       | 1                | D <sub>0</sub> |   |   |   |   |   |   |   | D <sub>1</sub> |    |    |    |    |    |    |                | D <sub>2</sub> |    |    |    |    |    |                |                | D <sub>3</sub> |    |    |    |    |                |                |                | D <sub>4</sub> |    |    |    |                |                |                |                | D <sub>5</sub> |    |    |                |                |                |                |                | D <sub>6</sub> |    |                |                |                |                |                |                | D <sub>7</sub> |                |                |                |                |                |                |                |      |      |      |      |      |      |      |      |
+| <b>Control block formats</b>                                                                                            | <b>Block type field</b> |                  |                |   |   |   |   |   |   |   |                |    |    |    |    |    |    |                |                |    |    |    |    |    |                |                |                |    |    |    |    |                |                |                |                |    |    |    |                |                |                |                |                |    |    |                |                |                |                |                |                |    |                |                |                |                |                |                |                |                |                |                |                |                |                |                |      |      |      |      |      |      |      |      |
+| C <sub>0</sub> C <sub>1</sub> C <sub>2</sub> C <sub>3</sub> C <sub>4</sub> C <sub>5</sub> C <sub>6</sub> C <sub>7</sub> | 1                       | 0                | 0x1e           |   |   |   |   |   |   |   | C <sub>0</sub> |    |    |    |    |    |    | C <sub>1</sub> |                |    |    |    |    |    | C <sub>2</sub> |                |                |    |    |    |    | C <sub>3</sub> |                |                |                |    |    |    | C <sub>4</sub> |                |                |                |                |    |    | C <sub>5</sub> |                |                |                |                |                |    | C <sub>6</sub> |                |                |                |                |                |                | C <sub>7</sub> |                |                |                |                |                |                | 0001 |      |      |      |      |      |      |      |
+| C <sub>0</sub> C <sub>1</sub> C <sub>2</sub> C <sub>3</sub> O <sub>4</sub> D <sub>5</sub> D <sub>6</sub> D <sub>7</sub> | 1                       | 0                | 0x2d           |   |   |   |   |   |   |   | C <sub>0</sub> |    |    |    |    |    |    | C <sub>1</sub> |                |    |    |    |    |    | C <sub>2</sub> |                |                |    |    |    |    | C <sub>3</sub> |                |                |                |    |    |    | O <sub>4</sub> |                |                |                | D <sub>5</sub> |    |    |                |                |                |                |                | D <sub>6</sub> |    |                |                |                |                |                |                | D <sub>7</sub> |                |                |                |                |                |                |                | 0010 |      |      |      |      |      |      |      |
+| C <sub>0</sub> C <sub>1</sub> C <sub>2</sub> C <sub>3</sub> S <sub>4</sub> D <sub>5</sub> D <sub>6</sub> D <sub>7</sub> | 1                       | 0                | 0x33           |   |   |   |   |   |   |   | C <sub>0</sub> |    |    |    |    |    |    | C <sub>1</sub> |                |    |    |    |    |    | C <sub>2</sub> |                |                |    |    |    |    | C <sub>3</sub> |                |                |                |    |    |    |                |                |                |                | D <sub>5</sub> |    |    |                |                |                |                |                | D <sub>6</sub> |    |                |                |                |                |                |                | D <sub>7</sub> |                |                |                |                |                |                |                | 0111 |      |      |      |      |      |      |      |
+| O <sub>0</sub> D <sub>1</sub> D <sub>2</sub> D <sub>3</sub> S <sub>4</sub> D <sub>5</sub> D <sub>6</sub> D <sub>7</sub> | 1                       | 0                | 0x66           |   |   |   |   |   |   |   | D <sub>1</sub> |    |    |    |    |    |    |                | D <sub>2</sub> |    |    |    |    |    |                |                | D <sub>3</sub> |    |    |    |    |                |                |                | O <sub>0</sub> |    |    |    |                |                |                |                | D <sub>5</sub> |    |    |                |                |                |                |                | D <sub>6</sub> |    |                |                |                |                |                |                | D <sub>7</sub> |                |                |                |                |                |                |                | 1011 |      |      |      |      |      |      |      |
+| O <sub>0</sub> D <sub>1</sub> D <sub>2</sub> D <sub>3</sub> O <sub>4</sub> D <sub>5</sub> D <sub>6</sub> D <sub>7</sub> | 1                       | 0                | 0x55           |   |   |   |   |   |   |   | D <sub>1</sub> |    |    |    |    |    |    |                | D <sub>2</sub> |    |    |    |    |    |                |                | D <sub>3</sub> |    |    |    |    |                |                |                | O <sub>0</sub> |    |    |    | O <sub>4</sub> |                |                |                | D <sub>5</sub> |    |    |                |                |                |                |                | D <sub>6</sub> |    |                |                |                |                |                |                | D <sub>7</sub> |                |                |                |                |                |                |                | 1101 |      |      |      |      |      |      |      |
+| S <sub>0</sub> D <sub>1</sub> D <sub>2</sub> D <sub>3</sub> D <sub>4</sub> D <sub>5</sub> D <sub>6</sub> D <sub>7</sub> | 1                       | 0                | 0x78           |   |   |   |   |   |   |   | D <sub>1</sub> |    |    |    |    |    |    |                | D <sub>2</sub> |    |    |    |    |    |                |                | D <sub>3</sub> |    |    |    |    |                |                |                | D <sub>4</sub> |    |    |    |                |                |                |                | D <sub>5</sub> |    |    |                |                |                |                |                | D <sub>6</sub> |    |                |                |                |                |                |                | D <sub>7</sub> |                |                |                |                |                |                |                | 1110 |      |      |      |      |      |      |      |
+| O <sub>0</sub> D <sub>1</sub> D <sub>2</sub> D <sub>3</sub> C <sub>4</sub> C <sub>5</sub> C <sub>6</sub> C <sub>7</sub> | 1                       | 0                | 0x4b           |   |   |   |   |   |   |   | D <sub>1</sub> |    |    |    |    |    |    |                | D <sub>2</sub> |    |    |    |    |    |                |                | D <sub>3</sub> |    |    |    |    |                |                |                | O <sub>0</sub> |    |    |    | C <sub>4</sub> |                |                |                |                |    |    | C <sub>5</sub> |                |                |                |                |                |    | C <sub>6</sub> |                |                |                |                |                |                | C <sub>7</sub> |                |                |                |                |                |                | 1000 |      |      |      |      |      |      |      |
+| T <sub>0</sub> C <sub>1</sub> C <sub>2</sub> C <sub>3</sub> C <sub>4</sub> C <sub>5</sub> C <sub>6</sub> C <sub>7</sub> | 1                       | 0                | 0x87           |   |   |   |   |   |   |   |                |    |    |    |    |    |    | C <sub>1</sub> |                |    |    |    |    |    | C <sub>2</sub> |                |                |    |    |    |    | C <sub>3</sub> |                |                |                |    |    |    | C <sub>4</sub> |                |                |                |                |    |    | C <sub>5</sub> |                |                |                |                |                |    | C <sub>6</sub> |                |                |                |                |                |                | C <sub>7</sub> |                |                |                |                |                |                | 0011 |      |      |      |      |      |      |      |
+| D <sub>0</sub> T <sub>1</sub> C <sub>2</sub> C <sub>3</sub> C <sub>4</sub> C <sub>5</sub> C <sub>6</sub> C <sub>7</sub> | 1                       | 0                | 0x99           |   |   |   |   |   |   |   | D <sub>0</sub> |    |    |    |    |    |    |                |                |    |    |    |    |    |                | C <sub>2</sub> |                |    |    |    |    |                | C <sub>3</sub> |                |                |    |    |    |                | C <sub>4</sub> |                |                |                |    |    |                | C <sub>5</sub> |                |                |                |                |    |                | C <sub>6</sub> |                |                |                |                |                |                | C <sub>7</sub> |                |                |                |                |                |      | 0101 |      |      |      |      |      |      |
+| D <sub>0</sub> D <sub>1</sub> T <sub>2</sub> C <sub>3</sub> C <sub>4</sub> C <sub>5</sub> C <sub>6</sub> C <sub>7</sub> | 1                       | 0                | 0xaa           |   |   |   |   |   |   |   | D <sub>0</sub> |    |    |    |    |    |    |                | D <sub>1</sub> |    |    |    |    |    |                |                |                |    |    |    |    |                |                | C <sub>3</sub> |                |    |    |    |                |                | C <sub>4</sub> |                |                |    |    |                |                | C <sub>5</sub> |                |                |                |    |                |                | C <sub>6</sub> |                |                |                |                |                |                | C <sub>7</sub> |                |                |                |                |      |      | 1001 |      |      |      |      |      |
+| D <sub>0</sub> D <sub>1</sub> D <sub>2</sub> T <sub>3</sub> C <sub>4</sub> C <sub>5</sub> C <sub>6</sub> C <sub>7</sub> | 1                       | 0                | 0xb4           |   |   |   |   |   |   |   | D <sub>0</sub> |    |    |    |    |    |    |                | D <sub>1</sub> |    |    |    |    |    |                |                | D <sub>2</sub> |    |    |    |    |                |                |                |                |    |    |    |                |                |                | C <sub>4</sub> |                |    |    |                |                |                | C <sub>5</sub> |                |                |    |                |                |                | C <sub>6</sub> |                |                |                |                |                |                | C <sub>7</sub> |                |                |                |      |      |      | 1010 |      |      |      |      |
+| D <sub>0</sub> D <sub>1</sub> D <sub>2</sub> D <sub>3</sub> T <sub>4</sub> C <sub>5</sub> C <sub>6</sub> C <sub>7</sub> | 1                       | 0                | 0xcc           |   |   |   |   |   |   |   | D <sub>0</sub> |    |    |    |    |    |    |                | D <sub>1</sub> |    |    |    |    |    |                |                | D <sub>2</sub> |    |    |    |    |                |                |                | D <sub>3</sub> |    |    |    |                |                |                |                |                |    |    |                |                |                |                | C <sub>5</sub> |                |    |                |                |                |                | C <sub>6</sub> |                |                |                |                |                |                | C <sub>7</sub> |                |                |      |      |      |      | 1100 |      |      |      |
+| D <sub>0</sub> D <sub>1</sub> D <sub>2</sub> D <sub>3</sub> D <sub>4</sub> T <sub>5</sub> C <sub>6</sub> C <sub>7</sub> | 1                       | 0                | 0xd2           |   |   |   |   |   |   |   | D <sub>0</sub> |    |    |    |    |    |    |                | D <sub>1</sub> |    |    |    |    |    |                |                | D <sub>2</sub> |    |    |    |    |                |                |                | D <sub>3</sub> |    |    |    |                |                |                |                | D <sub>4</sub> |    |    |                |                |                |                |                |                |    |                |                |                |                |                | C <sub>6</sub> |                |                |                |                |                |                | C <sub>7</sub> |                |      |      |      |      |      | 0110 |      |      |
+| D <sub>0</sub> D <sub>1</sub> D <sub>2</sub> D <sub>3</sub> D <sub>4</sub> D <sub>5</sub> T <sub>6</sub> C <sub>7</sub> | 1                       | 0                | 0xe1           |   |   |   |   |   |   |   | D <sub>0</sub> |    |    |    |    |    |    |                | D <sub>1</sub> |    |    |    |    |    |                |                | D <sub>2</sub> |    |    |    |    |                |                |                | D <sub>3</sub> |    |    |    |                |                |                |                | D <sub>4</sub> |    |    |                |                |                |                |                | D <sub>5</sub> |    |                |                |                |                |                |                |                |                |                |                |                |                |                | C <sub>7</sub> |      |      |      |      |      |      | 0000 |      |
+| D <sub>0</sub> D <sub>1</sub> D <sub>2</sub> D <sub>3</sub> D <sub>4</sub> D <sub>5</sub> D <sub>6</sub> T <sub>7</sub> | 1                       | 0                | 0xff           |   |   |   |   |   |   |   | D <sub>0</sub> |    |    |    |    |    |    |                | D <sub>1</sub> |    |    |    |    |    |                |                | D <sub>2</sub> |    |    |    |    |                |                |                | D <sub>3</sub> |    |    |    |                |                |                |                | D <sub>4</sub> |    |    |                |                |                |                |                | D <sub>5</sub> |    |                |                |                |                |                |                | D <sub>6</sub> |                |                |                |                |                |                |                |      |      |      |      |      |      |      | 1111 |
+
+**Figure B.2 – 66B Block coding**
+
+184 Rec. ITU-T G.709/Y.1331 (06/2020)
+
+![Diagram showing the mapping of 8 x 66B blocks to a 513B block. The left side shows 8 blocks: five '01' data blocks (D0-D7) and three '10' control blocks (Block type + 56-bit control characters). These are mapped via an interleaver process, marked with a green 'F' bit, to the right side. The right side shows the 513B block structure. It begins with a header containing FC, POS, and CB type fields. Below the header, the block contains the 56-bit control characters from the input control blocks, followed by the data bytes (D0-D7) from the input data blocks. Transmission order is indicated by arrows and bit labels (b<sup>7</sup>: MSB, b<sup>0</sup>: LSB) in IEEE 802.3.](ca7e6c1823b101e869d4f177c147bea6_img.jpg)
+
+1 2 3 4 5 6 7 8 → Transmission Order
+
+FC POS CB type
+
+01 D0 D1 D2 D3 D4 D5 D6 D7
+
+01 D0 D1 D2 D3 D4 D5 D6 D7
+
+01 D0 D1 D2 D3 D4 D5 D6 D7
+
+01 D0 D1 D2 D3 D4 D5 D6 D7
+
+10 Block type 56-bit control characters (7-byte)
+
+10 Block type 56-bit control characters (7-byte)
+
+10 Block type 56-bit control characters (7-byte)
+
+01 D0 D1 D2 D3 D4 D5 D6 D7
+
+12345678 → Transmission Order
+
+b<sup>7</sup>: MSB  
+b<sup>0</sup>: LSB } in IEEE 802.3
+
+56-bit control characters (7-byte)
+
+56-bit control characters (7-byte)
+
+56-bit control characters (7-byte)
+
+D0 D1 D2 D3 D4 D5 D6 D7
+
+D0 D1 D2 D3 D4 D5 D6 D7
+
+D0 D1 D2 D3 D4 D5 D6 D7
+
+D0 D1 D2 D3 D4 D5 D6 D7
+
+D0 D1 D2 D3 D4 D5 D6 D7
+
+12345678 → Transmission Order
+
+b<sup>7</sup>: MSB  
+b<sup>0</sup>: LSB } in IEEE 802.3
+
+8 x 66B blocks
+
+513B block
+
+Diagram showing the mapping of 8 x 66B blocks to a 513B block. The left side shows 8 blocks: five '01' data blocks (D0-D7) and three '10' control blocks (Block type + 56-bit control characters). These are mapped via an interleaver process, marked with a green 'F' bit, to the right side. The right side shows the 513B block structure. It begins with a header containing FC, POS, and CB type fields. Below the header, the block contains the 56-bit control characters from the input control blocks, followed by the data bytes (D0-D7) from the input data blocks. Transmission order is indicated by arrows and bit labels (b<sup>7</sup>: MSB, b<sup>0</sup>: LSB) in IEEE 802.3.
+
+Figure B.3 – 513B block code format
+
+Each of the 66B blocks is encoded into a row of the 8-byte by 8-row structure. Any 66B control blocks (CBi) are placed into the uppermost rows of the structure in the order received, while any all-data 66B blocks (DBi) are placed into the lowermost rows of the structure in the order received.
+
+The flag bit "F" is 1 if the 513B structure contains at least one 66B control block, and 0 if the 513B structure contains eight all-data 66B blocks. Because the 66B control blocks are placed into the uppermost rows of the 513B block, if the flag bit "F" is 1, then the first row will contain a mapping of a 66B control block.
+
+A 66B control block is encoded into a row of the structure shown in Figure B.3 as follows: the sync header of "10" is removed. The byte representing the block type field (see Figure B.2) is replaced by the structure shown in Figure B.4:
+
+![](b1a6ab9f3d33d6e8d64173bfa595b763_img.jpg)
+
+|    |  |     |  |    |      |
+|----|--|-----|--|----|------|
+| FC |  | POS |  | CB | TYPE |
+|----|--|-----|--|----|------|
+
+G.709-Y.1331(12)\_FB.4
+
+**Figure B.4 – 513B block's control block header**
+
+The byte indicating the control block type (one of 15 legal values) is translated into a 4-bit code according to the rightmost column of Figure B.2. The 3-bit POS field is used to encode the position in which this control block was received in the sequence of eight 66B blocks. The flag continuation bit "FC" will be set to a 0 if this is the final 66B control block or PCS lane alignment marker encoded in this 513B block, or to a 1 if one or more 66B control blocks or PCS lane alignment markers follow this one. At the decoder, the flag bit for the 513B block as a whole, plus the flag continuation bits in each row containing the mapping of a 66B control block or PCS lane alignment marker will allow identification of those rows, which can then be restored to their original position amongst any all-data 66B blocks at the egress according to the POS field. The remaining 7 bytes of the row are filled with the last 7 bytes of the 66B control block.
+
+An all-data 66B block is encoded into a row of the 513B block by dropping the sync header and copying the remaining eight bytes into the row. If all eight rows of the 513B block are placements of 66B all-data blocks, the flag bit "F" will be 0. If fewer than eight rows of the 513B block are placements of 66B all-data blocks, they will appear at the end, and the row containing the placement of the final 66B control block will have a flag continuation bit "FC" value of 0.
+
+The decoder operates in the reverse of the encoder to reconstruct the original sequence of 66B blocks. If flag bit "F" is 1, then 66B control blocks starting from the first row of the block are reconstructed and placed in the position indicated by the POS field. This process continues through all of the control blocks working downward from the top row. The final 66B control block placed within the 513B block will be identified when the flag continuation bit "FC" is zero.
+
+The structure of the 512B/513B code block is shown in Figure B.5. For example, if there is a single 64B/66B control block CB1 in a 512B/513B code block and it was originally located between 64B/66B data blocks DB2 and DB3, the first octet of the 64B character will contain 0.010.1101.CB1; the leading bit in the control octet of 0 indicates the flag continuation "FC" that this 64B control block is the last one in the 512B/513B code block, the value of 010 indicates CB1's position "POS" between DB2 and DB3, and the value of 1101 is a four-bit representation of the control code's block type "CB TYPE" (of which the eight-bit original block type is 0x55).
+
+| Input client characters         | Flag bit | 512-bit (64-Octet) field |                   |                   |                   |                   |                   |                   |                   |
+|---------------------------------|----------|--------------------------|-------------------|-------------------|-------------------|-------------------|-------------------|-------------------|-------------------|
+| All data block                  | 0        | DB1                      | DB2               | DB3               | DB4               | DB5               | DB6               | DB7               | DB8               |
+| 7 data block<br>1 control block | 1        | 0 AAA aaaa<br>CB1        | DB1               | DB2               | DB3               | DB4               | DB5               | DB6               | DB7               |
+| 6 data block<br>2 control block | 1        | 1 AAA aaaa<br>CB1        | 0 BBB bbbb<br>CB2 | DB1               | DB2               | DB3               | DB4               | DB5               | DB6               |
+| 5 data block<br>3 control block | 1        | 1 AAA aaaa<br>CB1        | 1 BBB bbbb<br>CB2 | 0 CCC cccc<br>CB3 | DB1               | DB2               | DB3               | DB4               | DB5               |
+| 4 data block<br>4 control block | 1        | 1 AAA aaaa<br>CB1        | 1 BBB bbbb<br>CB2 | 1 CCC cccc<br>CB3 | 0 DDD dddd<br>CB4 | DB1               | DB2               | DB3               | DB4               |
+| 3 data block<br>5 control block | 1        | 1 AAA aaaa<br>CB1        | 1 BBB bbbb<br>CB2 | 1 CCC cccc<br>CB3 | 1 DDD dddd<br>CB4 | 0 EEE eeee<br>CB5 | DB1               | DB2               | DB3               |
+| 2 data block<br>6 control block | 1        | 1 AAA aaaa<br>CB1        | 1 BBB bbbb<br>CB2 | 1 CCC cccc<br>CB3 | 1 DDD dddd<br>CB4 | 1 EEE eeee<br>CB5 | 0 FFF ffff<br>CB6 | DB1               | DB2               |
+| 1 data block<br>7 control block | 1        | 1 AAA aaaa<br>CB1        | 1 BBB bbbb<br>CB2 | 1 CCC cccc<br>CB3 | 1 DDD dddd<br>CB4 | 1 EEE eeee<br>CB5 | 1 FFF ffff<br>CB6 | 0 GGG gggg<br>CB7 | DB1               |
+| 8 control block                 | 1        | 1 AAA aaaa<br>CB1        | 1 BBB bbbb<br>CB2 | 1 CCC cccc<br>CB3 | 1 DDD dddd<br>CB4 | 1 EEE eeee<br>CB5 | 1 FFF ffff<br>CB6 | 1 GGG gggg<br>CB7 | 0 HHH hhhh<br>CB8 |
+
+- Leading bit in a 66B control block FC = 1 if there are more than 66B control block and = 0 if this payload contains the last control block in that 513B block  
+ - AAA = 3-bit representation of the first control code's original position (First control code locator: POS)  
+ - BBB = 3-bit representation of the second control code's original position (Second control code locator: POS)  
+ .....  
+ - HHH = 3-bit representation of the eighth control code's original position (Eighth control code locator: POS)  
+ - aaa = 4-bit representation of the first control code's type (first control block type: CB TYPE)  
+ - bbb = 4-bit representation of the second control code's type (Second control block type: CB TYPE)  
+ .....  
+ -hhh = 4-bit representation of the eighth control code's type (Eighth control block type: CB TYPE)  
+ - CBi = 56-bit representation of the i-th control code characters  
+ - DBi = 64-bit representation of the i-th data value in order of transmission
+
+G.709-Y.1331(12)\_FB.5
+
+**Figure B.5 – 513B code block components**
+
+### B.3.1 Errors detected before 512B/513B encoder
+
+A set of errors might be detected at the 64B/66B PCS receive process which, in addition to appropriate alarming, needs to send the appropriate signal downstream.
+
+Errors encountered before the encoder, such as loss of client signal, will result in the insertion of an Ethernet LF sequence ordered set prior to this process, which will be transcoded as any other control block. The same action should be taken as a result of failure to achieve 66B block lock on an input signal.
+
+An invalid 66B block will be converted to an error control block before transcoding and the OTN BIP-8 calculation as described in clause E.4.1. An invalid 66B block is one which does not have a sync header of "01" or "10", or one which has a sync header of "10" and a control block type field which does not appear in Figure B.2. An error control block has sync bits of "10", a block type code of 0x1E, and 8 seven-bit/E/error control characters. This will prevent the Ethernet receiver from interpreting a sequence of bits containing this error as a valid packet.
+
+### B.3.2 Errors detected by 512B/513B decoder
+
+Several mechanisms will be employed to reduce the probability that the decoder constructs erroneous 64B/66B encoded data at the egress if bit errors have corrupted. Since detectable corruption normally means that the proper order of 66B blocks to construct at the decoder cannot be reliably determined, if any of these checks fail, the decoder will transmit eight 66B error control blocks (sync="10", control block type=0x1e, and eight 7-bit/E/control characters).
+
+Mechanisms for improving the robustness and for 513B block lock are discussed in Annex F.
+
+#### **B.4 Link fault signalling**
+
+In-band link fault signalling in the client 64B/66B code (e.g., if a local fault or remote fault sequence ordered set is being transmitted between Ethernet equipments) is carried transparently according to this transcoding.
+
+## Annex C
+
+### Adaptation of OTU3 and OTU4 over multichannel parallel interfaces
+
+(This annex forms an integral part of this Recommendation.)
+
+NOTE 1 – This mechanism is designed to allow the use of the optical modules being developed for IEEE 40GBASE-R and 100GBASE-R signals for short-reach client-side OTU3 and OTU4 interfaces respectively. The corresponding physical layer specifications are being added to [ITU-T G.695] and [ITU-T G.959.1].
+
+OTU3 signals may be carried over parallel interfaces consisting of four lanes. This four-lane format is referred to as the OTL3.4 format.
+
+OTU4 signals may be carried over parallel interfaces consisting of four or ten lanes, which are formed by bit multiplexing of 20 logical lanes. The four-lane format is referred to as the OTL4.4 signal format and the ten-lane format is referred to as the OTL4.10 signal format.
+
+NOTE 2 – Ten lane IEEE 100GBASE-R interfaces have no corresponding ITU-T physical layer interface specification.
+
+The OTU3 and OTU4 frames are inversely multiplexed over physical/logical lanes on a 16-byte boundary aligned with the OTUk frame as illustrated in Figure C.1. The OTUk frame is divided into 1020 groups of 16-bytes.
+
+|   |             |             |             |             |       |             |
+|---|-------------|-------------|-------------|-------------|-------|-------------|
+| 1 | 1:16 (FAS)  | 17:32       | 33:48       | 49:64       |       | 4065:4080   |
+| 2 | 4081:4096   | 4097:5012   | 5013:5028   | 5029:5044   | ..... | 9145:9160   |
+| 3 | 9161:9176   | 9177:9192   | 9193:9208   | 9209:9224   |       | 12225:12240 |
+| 4 | 12241:12256 | 12257:12272 | 12273:12288 | 12289:13304 |       | 16305:16320 |
+
+G.709-Y.1331(20)\_FC.1
+
+Figure C.1 – OTU3 and OTU4 frames divided on 16-byte boundary
+
+#### OTU3 16-byte increment distribution
+
+Each 16-byte increment of an OTU3 frame is distributed round robin, to each of the four physical lanes. On each OTU3 frame boundary the lane assignments are rotated.
+
+For OTU3, the lane rotation and assignment is determined by the two LSBs of the MFAS as described in Table C.1 and Figure C.2, which indicates the starting group of bytes of the OTU3 frame that are sent on each lane.
+
+NOTE 3 – MFAS is scrambled as defined in clause 11.2.
+
+The pattern repeats every 64 bytes until the end of the OTU3 frame. The following OTU3 frame will use different lane assignments according to the MFAS.
+
+Table C.1 – Lane rotation assignments for OTU3
+
+| MFAS 7-8 | Lane 0 | Lane 1 | Lane 2 | Lane 3 |
+|----------|--------|--------|--------|--------|
+| *00      | 1:16   | 17:32  | 33:48  | 49:64  |
+| *01      | 49:64  | 1:16   | 17:32  | 33:48  |
+| *10      | 33:48  | 49:64  | 1:16   | 17:32  |
+| *11      | 17:32  | 33:48  | 49:64  | 1:16   |
+
+The distribution of 16-byte blocks from the sequence of OTU3 frames is illustrated in Figure C.2:
+
+The parallel lanes can be reassembled at the sink by first recovering framing on each of the parallel lanes, then recovering the lane identifiers and then performing lane de-skewing. Frame alignment, lane identifier recovery and multi-lane alignment should operate under  $10^{-3}$  bit error rate conditions before error correction. Refer to [ITU-T G.798] for the specific processing details.
+
+The lane rotation mechanism will place the first 16 bytes of the OTU3 frame on each lane once per  $4080 \times 4$  (i.e., 16320) bytes (the same as an OTU3 itself). The two LSBs of the MFAS will be the same in each FAS on a particular lane, which allows the lane to be identified. Since the MFAS cycles through 256 distinct values, the lanes can be de-skewed and reassembled by the receiver as long as the total skew does not exceed 127 OTU3 frame periods (approximately 385  $\mu\text{s}$ ). The receiver must use the MFAS to identify each received lane, as lane positions may not be preserved by the optical modules to be used for this application.
+
+#### OTU4 16-byte increment distribution
+
+Each 16-byte increment of an OTU4 frame is distributed, round robin, to each of the 20 logical lanes. On each OTU4 frame boundary the lane assignments are rotated.
+
+For distribution of OTU4 to twenty logical lanes, since the MFAS is not a multiple of 20, a different marking mechanism must be used. Since the frame alignment signal is 6 bytes (48 bits) and as per [ITU-T G.798] only 32 bits must be checked for frame alignment, the third OA2 byte position will be borrowed as a logical lane marker (LLM). For maximum skew detection range, the lane marker value will increment on successive frames from 0-239 (240 values being the largest multiple of 20 that can be represented in 8-bits). LLM = 0 position shall be aligned with MFAS = 0 position every 3840 (the least common multiple of 240 and 256) frame periods. The logical lane number can be recovered from this value by a modulo 20 operation. Table C.2 and Figure C.3 illustrate how bytes of the OTU4 are distributed in 16-byte increments across the 20 logical lanes.
+
+The pattern repeats every 320 bytes until the end of the OTU4 frame.
+
+The following OTU4 frame will use different lane assignment according to the LLM MOD 20.
+
+**Table C.2 – Lane rotation assignments for OTU4**
+
+| LLM MOD 20 | Lane 0  | Lane 1 | ..... | Lane 18 | Lane 19 |
+|------------|---------|--------|-------|---------|---------|
+| 0          | 1:16    | 17:32  |       | 289:304 | 305:320 |
+| 1          | 305:320 | 1:16   |       | 273:288 | 289:304 |
+| :          |         |        |       |         |         |
+| 18         | 33:48   | 49:64  |       | 1:16    | 17:32   |
+| 19         | 17:32   | 33:48  |       | 305:320 | 1:16    |
+
+The distribution of 16-byte blocks from the sequence of OTU4 frames is illustrated in Figure C.3.
+
+The parallel lanes can be reassembled at the sink by first recovering framing on each of the parallel lanes, then recovering the lane identifiers and then performing de-skewing of the lanes. Frame alignment, lane identifier recovery and multi-lane alignment should operate under  $10^{-3}$  bit error rate conditions before error correction. Refer to [ITU-T G.798] for specific processing details.
+
+The lane rotation mechanism will place the first 16 bytes of the OTU4 frame on each lane once per  $4080 \times 4$  (i.e., 16320) bytes (the same as an OTU4 itself). The "LLM MOD 20" will be the same in each FAS on a particular lane, which allows the lane to be identified. Since the LLM cycles through 240 distinct values, the lanes can be de-skewed and reassembled by the receiver as long as the total skew does not exceed 119 OTU4 frame periods (approximately 139  $\mu\text{s}$ ). The receiver must use the
+
+"LLM MOD 20" to identify each received lane, as lane positions may not be preserved by the optical modules to be used for this application.
+
+The lanes are identified, de-skewed, and reassembled into the original OTU4 frame according to the lane marker. The MFAS can be combined with the lane marker to provide additional skew detection range, the maximum being up to the least common multiple "LCM(240, 256)/2 - 1" or 1919 OTU4 frame periods (approximately 2.241 ms). In mapping from lanes back to the OTU4 frame, the sixth byte of each OTU4 frame which was borrowed for lane marking is restored to the value OA2.
+
+Each physical lane of an OTL4.4 carried over a multi-lane interface is formed by simple bit multiplexing of five logical lanes. At the sink, the bits are disinterleaved into five logical lanes from each physical lane. The sink will identify each logical lane according to the lane marker in the LLM byte. The sink must be able to accept the logical lanes in any position as the ordering of bit multiplexing on each physical lane is arbitrary; the optical module hardware to be used for this application is permitted full flexibility concerning which physical lane will be used for output of each logical lane, and the order of bit multiplexing of logical lanes on each physical output lane.
+
+NOTE 4 – Ten-lane IEEE 100GBASE-R interfaces are specified, although not with ITU-T physical layer specifications. These interfaces may be compatible with a 10-lane interface for OTU4 (OTL4.10), each lane consisting of two bit-multiplexed logical lanes. Refer to[b-ITU-T G-Sup.58].
+
+This mechanism handles any normally framed OTU3 or OTU4 sequence.
+
+![Figure C.2: Distribution of bytes from OTU3 to parallel lanes. This diagram shows four lanes (Lane 0 to Lane 3) with byte ranges and MFAS values. Lane 0 starts with 1:16 (FAS) and ends with 1:16 (FAS). MFAS values are xxxxx xx00, xxxxx xx01, xxxxx xx10, and xxxxx xx11. Rotation points are indicated between lanes.](5bd8085079508bb158cfc55b1007a459_img.jpg)
+
+Figure C.2 illustrates the distribution of bytes from an OTU3 frame across four parallel lanes (Lane 0 to Lane 3). The lanes are shown with byte ranges and MFAS (Multi-Frame Alignment Sequence) values. Lane 0 starts with 1:16 (FAS) and ends with 1:16 (FAS). MFAS values are xxxxx xx00, xxxxx xx01, xxxxx xx10, and xxxxx xx11. Rotation points are indicated between lanes.
+
+| Lane   | Start      | End        | MFAS      |
+|--------|------------|------------|-----------|
+| Lane 0 | 1:16 (FAS) | 1:16 (FAS) | xxxx xx00 |
+| Lane 1 | 17:32      | 17:32      | xxxx xx01 |
+| Lane 2 | 33:48      | 33:48      | xxxx xx10 |
+| Lane 3 | 49:64      | 49:64      | xxxx xx11 |
+
+G.709-Y.1331(12)\_FC.2
+
+Figure C.2: Distribution of bytes from OTU3 to parallel lanes. This diagram shows four lanes (Lane 0 to Lane 3) with byte ranges and MFAS values. Lane 0 starts with 1:16 (FAS) and ends with 1:16 (FAS). MFAS values are xxxxx xx00, xxxxx xx01, xxxxx xx10, and xxxxx xx11. Rotation points are indicated between lanes.
+
+Figure C.2 – Distribution of bytes from OTU3 to parallel lanes
+
+![Figure C.3: Distribution of bytes from OTU4 to parallel lanes. This diagram shows 20 lanes (Lane 0 to Lane 19) with byte ranges and LLM MOD 20 values. LLM MOD 20 values are 0, 1, 18, and 19. Rotation points are indicated between lanes.](1f980b98800c29272e0e5ba2f6db4b98_img.jpg)
+
+Figure C.3 illustrates the distribution of bytes from an OTU4 frame across 20 parallel lanes (Lane 0 to Lane 19). The lanes are shown with byte ranges and LLM (Lane Label) MOD 20 values. LLM MOD 20 values are 0, 1, 18, and 19. Rotation points are indicated between lanes.
+
+| Lane    | Start      | End        | LLM MOD 20 |
+|---------|------------|------------|------------|
+| Lane 0  | 1:16 (FAS) | 1:16 (FAS) | 0          |
+| Lane 1  | 17:32      | 17:32      | 1          |
+| ...     | ...        | ...        | ...        |
+| Lane 18 | 289:304    | 289:304    | 18         |
+| Lane 19 | 305:320    | 305:320    | 19         |
+
+G.709-Y.1331(12)\_FC.3
+
+Figure C.3: Distribution of bytes from OTU4 to parallel lanes. This diagram shows 20 lanes (Lane 0 to Lane 19) with byte ranges and LLM MOD 20 values. LLM MOD 20 values are 0, 1, 18, and 19. Rotation points are indicated between lanes.
+
+Figure C.3 – Distribution of bytes from OTU4 to parallel lanes
+
+## Annex D
+
+### Generic mapping procedure principles
+
+(This annex forms an integral part of this Recommendation.)
+
+#### D.1 Basic principle
+
+For any given CBR client signal, the number of n-bit (e.g., n = 1/8, 1, 8) data entities that arrive during one server frame or server multiframe period is defined by:
+
+$$c_n = \left( \frac{f_{client}}{n} \times T_{server} \right) \quad (D-1)$$
+
+$f_{client}$ : client bit rate
+
+$T_{server}$ : frame period of the server frame or server multiframe
+
+$c_n$ : number of client n-bit data entities per server frame or server multiframe
+
+As only an integer number of n-bit data entities can be transported per server frame or multiframe, the integer value  $C_n(t)$  of  $c_n$  has to be used. Since it is required that no client information is lost, the rounding process to the integer value has to take care of the truncated part, e.g., a  $c_n$  with a value of 10.25 has to be represented by the integer sequence 10,10,10,11.
+
+$$C_n(t) = \text{int} \left( \frac{f_{client}}{n} \times T_{server} \right) \quad (D-2)$$
+
+$C_n(t)$ : number of client n-bit data entities per server frame t or server multiframe t (integer)
+
+For the case  $c_n$  is not an integer,  $C_n(t)$  will vary between:
+
+$$C_n(t) = \text{floor} \left( \frac{f_{client}}{n} \times T_{server} \right) \quad (D-3)$$
+
+and
+
+$$C_n(t) = \text{ceiling} \left( \frac{f_{client}}{n} \times T_{server} \right) = 1 + \text{floor} \left( \frac{f_{client}}{n} \times T_{server} \right) \quad (D-4)$$
+
+The server frame or multiframe rate is defined by the server bit rate and the number of bits per server frame or multiframe:
+
+$$T_{server} = \frac{B_{server}}{f_{server}} \quad (D-5)$$
+
+$f_{server}$ : server bit rate
+
+$B_{server}$ : bits per server frame or multiframe
+
+Combining (D-5) with (D-1) and (D-2) results in:
+
+$$c_n = \left( \frac{f_{client}}{f_{server}} \times \frac{B_{server}}{n} \right) \quad (D-6)$$
+
+and
+
+$$C_n(t) = \text{int} \left( \frac{f_{client}}{f_{server}} \times \frac{B_{server}}{n} \right) \quad (D-7)$$
+
+As the client data has to fit into the payload area of the server signal, the maximum value of  $C_n$  and as such the maximum client bit rate is limited by the size of the server payload area.
+
+$$C_n(t) \leq P_{server} \quad (D-8)$$
+
+$$f_{client} \leq f_{server} \times \frac{P_{server}}{B_{server}} \times n \quad (D-9)$$
+
+$P_{server}$ : maximum number of (n bits) data entities in the server payload area
+
+The client and server bit rate are independent. This allows specifying the server bit rate independently from the client bit rates. Furthermore, client clock impairments are not seen at the server clock.
+
+If the client or server bit rate changes due to client or server frequency tolerances,  $c_n$  and  $C_n(t)$  change accordingly. A special procedure has to take care that  $C_n(t)$  is changed fast enough to the correct value during start-up or during a step in the client bit rate (e.g., when the client signal is replaced by its AIS signal or the AIS signal is replaced by the client signal). This procedure may be designed to prevent buffer over-/underflow, or an additional buffer over-/underflow prevention method has to be deployed.
+
+A transparent mapping has to determine  $C_n(t)$  on a server (multi)frame per (multi)frame base.
+
+In order to extract the correct number of client information entities at the de-mapper,  $C_n(t)$  has to be transported in the overhead area of the server frame or multiframe from the mapper to the de-mapper.
+
+Figure D.1 shows the generic functionality of the mapper and de-mapper circuit.
+
+At the mapper,  $C_n(t)$  is determined based on the client and server clocks. The client data is constantly written into the buffer memory. The read out is controlled by the value of  $C_n(t)$ .
+
+At the de-mapper,  $C_n(t)$  is extracted from the overhead.  $C_n(t)$  controls the write enable signal for the buffer. The client clock is generated based on the server clock and the value of  $C_n(t)$ .
+
+$C_n(t)$  has to be determined first, then it has to be inserted into the overhead and afterwards  $C_n(t)$  client data entities have to be inserted into the payload area of the server as shown in Figure D.2.
+
+![Figure D.1: Generic functionality of a mapper/de-mapper circuit. The diagram is split into two parts: (a) Mapper and (b) De-mapper. In (a), 'Client data' and 'Client clock' enter a 'Buffer and determine Cn' block. This block outputs 'Data' and 'Cn' to an 'OH insertion' block, which produces 'Server data'. A 'Read control' block receives 'Cn' and 'Server clock' and sends a 'Read enable' signal back to the buffer. In (b), 'Server data' enters an 'OH extraction' block, which outputs 'Cn' to a 'Buffer and generate client clock' block and to a 'Read control' block. The 'Read control' block also receives 'Server clock' and sends a 'Write enable' signal to the buffer. The buffer outputs 'Client data' and 'Client clock'.](62e9df3ad37499202f4095077606230f_img.jpg)
+
+Figure D.1: Generic functionality of a mapper/de-mapper circuit. The diagram is split into two parts: (a) Mapper and (b) De-mapper. In (a), 'Client data' and 'Client clock' enter a 'Buffer and determine Cn' block. This block outputs 'Data' and 'Cn' to an 'OH insertion' block, which produces 'Server data'. A 'Read control' block receives 'Cn' and 'Server clock' and sends a 'Read enable' signal back to the buffer. In (b), 'Server data' enters an 'OH extraction' block, which outputs 'Cn' to a 'Buffer and generate client clock' block and to a 'Read control' block. The 'Read control' block also receives 'Server clock' and sends a 'Write enable' signal to the buffer. The buffer outputs 'Client data' and 'Client clock'.
+
+**Figure D.1 – Generic functionality of a mapper/de-mapper circuit**
+
+![Figure D.2: Processing flow diagram showing Mapper and De-mapper operations. The Mapper side shows three frames with OH and Payload area. Arrows indicate 'Determine Cn' from the payload area, 'Insert Cn into OH', and 'Insert Cn client data' into the payload area. The De-mapper side shows the reverse process: 'Extract Cn from OH' and 'Extract Cn client data' from the payload area. Reference G.709-Y.1331(12)_FD.2 is noted.](0fdef87ff1fd322c626d1ff8df725749_img.jpg)
+
+Figure D.2: Processing flow diagram showing Mapper and De-mapper operations. The Mapper side shows three frames with OH and Payload area. Arrows indicate 'Determine Cn' from the payload area, 'Insert Cn into OH', and 'Insert Cn client data' into the payload area. The De-mapper side shows the reverse process: 'Extract Cn from OH' and 'Extract Cn client data' from the payload area. Reference G.709-Y.1331(12)\_FD.2 is noted.
+
+**Figure D.2 – Processing flow**
+
+$C_n(t)$  client data entities are mapped into the payload area of the server frame or multiframe using a sigma-delta data/stuff mapping distribution. It provides a distributed mapping as shown in Figure D.3. Payload field  $j$  ( $j = 1 .. P_{server}$ ) carries:
+
+– client data (D)            if  $(j \times C_n(t)) \bmod P_{server} < C_n(t)$             (D-10)
+
+– stuff (S)                    if  $(j \times C_n(t)) \bmod P_{server} \geq C_n(t)$ .            (D-11)
+
+![Figure D.3: Sigma-delta based mapping diagram. It shows a grid representing the 'Payload area' of a 'Server frame or multiframe'. The first column is labeled 'OH'. The grid cells are shaded in a checkerboard pattern. Labels 'Client data' and 'Stuff' point to specific shaded cells. Reference G.709-Y.1331(12)_FD.3 is noted.](15d97ee42b0c3d8c1c45245583d67ff1_img.jpg)
+
+Figure D.3: Sigma-delta based mapping diagram. It shows a grid representing the 'Payload area' of a 'Server frame or multiframe'. The first column is labeled 'OH'. The grid cells are shaded in a checkerboard pattern. Labels 'Client data' and 'Stuff' point to specific shaded cells. Reference G.709-Y.1331(12)\_FD.3 is noted.
+
+**Figure D.3 – Sigma-delta based mapping**
+
+$C_n(t)$  client data entities have to be distributed over  $P_{server}$  locations. A client data entity has therefore to be inserted with a spacing of  $\frac{P_{server}}{C_n(t)}$ . This is normally not an integer value, however it can be emulated by an integer calculation using the sigma-delta method based on an overflow accumulator as shown in Figure D.4.
+
+The accumulator memory is reset to 0 at every frame start of the server frame. At every location of the payload area,  $C_n(t)$  is added to the memory and the result is compared with  $P_{server}$ . If the result is lower than  $P_{server}$ , it is stored back into the memory and no client data is indicated for this payload position. If it is equal or greater than  $P_{server}$ ,  $P_{server}$  is subtracted from the result and the new result is stored back in the memory. In addition, client data is indicated for the client position.
+
+![Figure D.4 – Sigma-delta accumulator. The diagram shows a feedback loop where an input signal C_n(t) is added to the output of a memory block via an adder. The output of this adder is then subtracted from a reference signal P_server at a second adder. The result of the second adder is passed through a comparator labeled '≥ P_server ?'. The output of the comparator is an 'Enable' signal that controls the 'Memory' block. The 'Memory' block also receives 'Payload area', 'Frame start', and 'Clock' signals. The output of the memory block is also connected to a 'Client data indication = read/write enable' signal. The diagram is labeled G.709-Y.1331(12)_FD.4.](c71cc20c24544f057770d4066ecaadc4_img.jpg)
+
+Figure D.4 – Sigma-delta accumulator. The diagram shows a feedback loop where an input signal C\_n(t) is added to the output of a memory block via an adder. The output of this adder is then subtracted from a reference signal P\_server at a second adder. The result of the second adder is passed through a comparator labeled '≥ P\_server ?'. The output of the comparator is an 'Enable' signal that controls the 'Memory' block. The 'Memory' block also receives 'Payload area', 'Frame start', and 'Clock' signals. The output of the memory block is also connected to a 'Client data indication = read/write enable' signal. The diagram is labeled G.709-Y.1331(12)\_FD.4.
+
+**Figure D.4 – Sigma-delta accumulator**
+
+As the same start value and  $C_n(t)$  are used at the mapper and de-mapper the same results are obtained and interworking is achieved.
+
+## D.2 Applying GMP in OTN
+
+Clauses 17.7, 19.6 and 20.5 specify GMP as the asynchronous generic mapping method for the mapping of CBR client signals into OPUk, the mapping of ODUs signals into a server OPUk (via the ODTUk.ts) and the mapping of ODUs signals into an OPUCn (via ODTUCn.ts).
+
+NOTE – GMP complements the traditional asynchronous client/server specific mapping method specified in clauses 17.6 and 19.5. GMP is intended to provide the justification of new CBR type client signals into OPUk.
+
+Asynchronous mappings in the OTN have a default 8-bit timing granularity. Such 8-bit timing granularity is supported in GMP by means of a  $c_n$  with  $n=8$  ( $c_8$ ). The jitter/wander requirements for some of the OTN client signals are such that for those signals an 8-bit timing granularity may not be sufficient. For such a case, a 1-bit timing granularity is supported in GMP by means of  $c_n$  with  $n=1$  ( $c_1$ ).
+
+### M-byte granularity mapping
+
+Clauses 17.7 and 19.6 specify that the mapping of CBR client bits into the payload of an OPUk and the mapping of ODUj bits into the payload of an ODTUk.ts is performed with  $8 \times M$ -bit (M-byte) granularity.
+
+The insertion of CBR client data into the payload area of the OPUk frame and the insertion of ODUj data into the payload area of the ODTUk.ts multiframe at the mapper is performed in M-byte (or m-bit,  $m = 8 \times M$ ) data entities, denoted as  $C_m(t)$ . The remaining  $C_{nb}(t)$  data entities are signalled in the justification overhead as additional timing/phase information.
+
+$$c_m = \left( \frac{n \times c_n}{m} \right) = \left( \frac{f_{client}}{f_{server}} \times \frac{B_{server}}{m} \right) = \left( \frac{f_{client}}{f_{server}} \times \frac{B_{server}}{8 \times M} \right) = \left( \frac{f_{client}}{f_{server}} \times \frac{B_{server} / 8}{M} \right) \quad (D-12)$$
+
+As only an integer number of m-bit data entities can be transported per server frame or multiframe, the integer value  $C_m(t)$  of  $c_m$  has to be used. Since it is required that no information is lost, the rounding process to the integer value has to take care of the truncated part, e.g., a  $c_m$  with a value of 10.25 has to be represented by the integer sequence 10,10,10,11.
+
+$$C_m(t) = \text{int}(c_m) = \text{int} \left( \frac{f_{client}}{f_{server}} \times \frac{B_{server} / 8}{M} \right) \quad (D-13)$$
+
+For the case  $c_m$  is not an integer,  $C_m(t)$  will vary between:
+
+$$C_m(t) = \text{floor}\left(\frac{f_{client}}{f_{server}} \times \frac{B_{server}/8}{M}\right) \text{ and } C_m(t) = \text{ceiling}\left(\frac{f_{client}}{f_{server}} \times \frac{B_{server}/8}{M}\right) \quad (D-14)$$
+
+The remainder of  $c_n$  and  $C_m(t)$  is:
+
+$$c_{nD} = c_n - \left(\frac{8 \times M}{n} \times C_m(t)\right) \quad (D-15)$$
+
+As only an integer number of  $c_{nD}$  n-bit data entities can be signalled per server frame or multiframe, the integer value  $C_{nD}(t)$  of  $c_{nD}$  has to be used.
+
+$$C_{nD}(t) = \text{int}(c_n) - \left(\frac{8 \times M}{n} \times C_m(t)\right) = C_n(t) - \left(\frac{8 \times M}{n} \times C_m(t)\right) \quad (D-16)$$
+
+$C_{nD}(t)$  is a number between  $1 - \frac{8 \times M}{n}$  and  $\frac{8 \times M}{n} - 1$ .
+
+### 16M-byte granularity mapping
+
+Clause 20.5 specifies that the mapping of ODUk bits into the payload of an ODUCn.ts is performed with  $128 \times M$ -bit (16M-byte) granularity.
+
+The insertion of ODUk data into the payload area of the ODTUCn.ts multiframe at the mapper is performed in 16M-byte (or m-bit,  $m = 128 \times M$ ) data entities, denoted as  $c_m(t)$ . The remaining  $C_{nD}(t)$  data entities are signalled in the justification overhead as additional timing/phase information.
+
+$$c_m = \left(\frac{n \times c_n}{m}\right) = \left(\frac{f_{client}}{f_{server}} \times \frac{B_{server}}{m}\right) = \left(\frac{f_{client}}{f_{server}} \times \frac{B_{server}}{128 \times M}\right) = \left(\frac{f_{client}}{f_{server}} \times \frac{B_{server}/128}{M}\right) \quad (D-17)$$
+
+As only an integer number of m-bit data entities can be transported per server frame or multiframe, the integer value  $C_m(t)$  of  $c_m$  has to be used. Since it is required that no information is lost, the rounding process to the integer value has to take care of the truncated part, e.g., a  $c_m$  with a value of 10.25 has to be represented by the integer sequence 10,10,10,11.
+
+$$C_m(t) = \text{int}(c_m) = \text{int}\left(\frac{f_{client}}{f_{server}} \times \frac{B_{server}/128}{M}\right) \quad (D-18)$$
+
+For the case  $c_m$  is not an integer,  $C_m(t)$  will vary between:
+
+$$C_m(t) = \text{floor}\left(\frac{f_{client}}{f_{server}} \times \frac{B_{server}/128}{M}\right) \text{ and } C_m(t) = \text{ceiling}\left(\frac{f_{client}}{f_{server}} \times \frac{B_{server}/128}{M}\right) \quad (D-19)$$
+
+The remainder of  $c_n$  and  $C_m(t)$  is:
+
+$$c_{nD} = c_n - \left(\frac{128 \times M}{n} \times C_m(t)\right) \quad (D-20)$$
+
+As only an integer number of  $c_{nD}$  n-bit data entities can be signalled per server frame or multiframe, the integer value  $C_{nD}(t)$  of  $c_{nD}$  has to be used.
+
+$$C_{nD}(t) = \text{int}(c_n) - \left(\frac{128 \times M}{n} \times C_m(t)\right) = C_n(t) - \left(\frac{128 \times M}{n} \times C_m(t)\right) \quad (D-21)$$
+
+$C_{nD}(t)$  is a number between  $1 - \frac{128 \times M}{n}$  and  $\frac{128 \times M}{n} - 1$ .
+
+As the client data has to fit into the payload area of the server signal, the maximum value of  $C_m$  and as such the maximum client bit rate is limited by the size of the server payload area.
+
+$$C_m(t) \leq P_{m,server} \quad (D-22)$$
+
+$P_{m,server}$ : maximum number of (m bits) data entities in the server payload area
+
+In order to extract the correct number of client information entities at the de-mapper,  $C_m(t)$  has to be transported in the overhead area of the server frame or multiframe from the mapper to the de-mapper.
+
+At the mapper,  $C_n(t)$  is determined based on the client and server clocks. The client data is constantly written into the buffer memory. The read out is controlled by the value of  $C_m(t)$ .
+
+At the de-mapper,  $C_m(t)$  and  $C_{nD}(t)$  are extracted from the overhead and used to compute  $C_n(t)$ .  $C_m(t)$  controls the write enable signal for the buffer. The client clock is generated based on the server clock and the value of  $C_n(t)$ .
+
+$C_n(t)$  has to be determined first, then it has to be inserted into the overhead as  $C_m(t)$  and  $\sum C_{nD}(t)$  and afterwards  $C_m(t)$  client data entities have to be inserted into the payload area of the server as shown in Figure D.5.
+
+The  $C_n(t)$  value determines the  $C_m(t)$  and  $C_{nD}(t)$  values;  $C_m(t) = \text{floor}(n/m \times C_n(t))$  and  $C_{nD}(t) = C_n(t) - (m/n \times C_m(t))$ . The values of  $C_{nD}(t)$  are accumulated and if  $\sum C_{nD}(t) \geq m/n$  then  $m/n$  is subtracted from  $\sum C_{nD}(t)$  and  $C_m(t)$  is incremented with +1. These latter two values are then encoded in the overhead bytes. This  $C_m(t)$  value is applied as input to the sigma-delta process.
+
+![Figure D.5: Processing flow for GMP in OTN. The diagram shows two columns representing the Mapper and the Demapper. The Mapper column shows three frames, each with an Overhead (OH) and a Payload area. Arrows indicate the flow: 'Determine C_n' from the payload areas, 'Insert C_m and sum C_nD into OH' into the overhead, and 'Insert C_m client data' into the payload. The Demapper column shows the same three frames. Arrows indicate the flow: 'Extract C_m and sum C_nD from OH' from the overhead, and 'Extract C_m client data' from the payload.](b4022f9f3b9a3b30ade5c100052cb16a_img.jpg)
+
+Figure D.5: Processing flow for GMP in OTN. The diagram shows two columns representing the Mapper and the Demapper. The Mapper column shows three frames, each with an Overhead (OH) and a Payload area. Arrows indicate the flow: 'Determine C\_n' from the payload areas, 'Insert C\_m and sum C\_nD into OH' into the overhead, and 'Insert C\_m client data' into the payload. The Demapper column shows the same three frames. Arrows indicate the flow: 'Extract C\_m and sum C\_nD from OH' from the overhead, and 'Extract C\_m client data' from the payload.
+
+G.709-Y.1331(12)\_FD.5
+
+**Figure D.5 – Processing flow for GMP in OTN**
+
+During start-up or during a step in the client bit rate, the value of  $C_n(t)$  will not match the actual number of n-bit client data entities arriving at the mapper buffer and the  $C_n(t)$  determination process has to adjust its value to the actual number of n-bit client data entities arriving. This adjustment method is implementation specific. During the mismatch period, the mapper buffer fill level may increase if more n-bit client data entities arrive per multiframe than there are transmitted, or decrease if less n-bit client data entities arrive per multiframe than there are transmitted.
+
+To prevent overflow or underflow of the mapper buffer and thus data loss, the fill level of the mapper buffer has to be monitored. For the case where too many m-bit client data entities are in the buffer, it is necessary to insert temporarily more m-bit client data entities in the server (multi)frame(s) than required by  $C_n(t)$ . For the case too few m-bit client data entities are in the buffer, it is necessary to insert temporarily fewer m-bit client data entities in the server (multi)frame(s) than required by  $C_n(t)$ . This behaviour is similar to the behaviour of AMP under these conditions.
+
+The OTN supports a number of client signal types for which transfer delay (latency) and transfer delay variation are critical parameters. Those client signal types require that the transfer delay introduced by the mapper plus de-mapper buffers is minimized and that the delay variation introduced by the mapper plus de-mapper buffers is minimized.
+
+In steady state periods,  $C_n(t)$  is a value in the range  $C_{n,min}$  to  $C_{n,max}$ . A value outside this range indicates that there is a misalignment of the expected client bit rate and the actual client bit rate. During transient periods after e.g., a frequency step,  $C_n(t)$  may be temporarily outside the range  $C_{n,min}$  to  $C_{n,max}$ .
+
+$C_m(t)$  client data entities are mapped into the payload area of the server frame or multiframe using a sigma-delta data/stuff mapping distribution. It provides a distributed mapping as shown in Figure D.3. Payload field  $j$  ( $j = 1 \dots P_{m,server}$ ) carries
+
+$$\begin{aligned} & \text{-- client data (D)} & \text{if } (j \times C_m(t)) \bmod P_{m,server} < C_m(t); & \text{(D-23)} \end{aligned}$$
+
+$$\begin{aligned} & \text{-- stuff (S)} & \text{if } (j \times C_m(t)) \bmod P_{m,server} \geq C_m(t). & \text{(D-24)} \end{aligned}$$
+
+### Values of $n$ , $m$ , $M$ , $f_{client}$ , $f_{server}$ , $T_{server}$ , $B_{server}$ , and $P_{m,server}$ for OPUk and ODTUk.ts
+
+The values for  $n$ ,  $m$ ,  $M$ ,  $f_{client}$ ,  $f_{server}$ ,  $T_{server}$ ,  $B_{server}$ , and  $P_{m,server}$  are specified in Table D.1.
+
+**Table D.1 – OPUk, ODTUk.ts and ODTUCn.ts GMP parameter values**
+
+| GMP parameter         | CBR client into OPUk                                                                                                                                       | ODUj into OPUk (ODTUk.ts)                                                                                                                                                                              | ODUk into OPUCn (ODTUCn.ts)                                                                                                                       |
+|-----------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------|
+| $n$                   | 8 (default)<br>1 (client specific)                                                                                                                         | 8                                                                                                                                                                                                      | 8                                                                                                                                                 |
+| $m$                   | $m = 8 \times M$<br>OPU0: $8 \times 1 = 8$<br>OPU1: $8 \times 2 = 16$<br>OPU2: $8 \times 8 = 64$<br>OPU3: $8 \times 32 = 256$<br>OPU4: $8 \times 80 = 640$ | $m = 8 \times M$<br>ODTU2.ts: $8 \times ts$<br>ODTU3.ts: $8 \times ts$<br>ODTU4.ts: $8 \times ts$<br>ODTU25.ts: $8 \times ts$<br>ODTU50.ts: $8 \times ts$                                              | $m = 128 \times M$<br>ODTUCn.ts: $128 \times ts$                                                                                                  |
+| $f_{client}$          | CBR client bit rate and tolerance                                                                                                                          | ODUj bit rate and tolerance (Table 7-2)                                                                                                                                                                | ODUk bit rate and tolerance (Table 7-2)                                                                                                           |
+| $f_{server}$          | OPUk Payload bit rate and tolerance (Table 7-3)                                                                                                            | ODTUk.ts Payload bit rate and tolerance (Table 7-7)                                                                                                                                                    | ODTUCn.ts Payload bit rate and tolerance (Table 7-7)                                                                                              |
+| $T_{server}$          | ODUk/OPUk frame period (Table 7-4)                                                                                                                         | OPUk multiframe period (Table 7-6)                                                                                                                                                                     | OPUCn multiframe period (Table 7-6)                                                                                                               |
+| $B_{server}$          | OPU0: $8 \times 15232$<br>OPU1: $8 \times 15232$<br>OPU2: $8 \times 15232$<br>OPU3: $8 \times 15232$<br>OPU4: $8 \times 15200$                             | ODTU2.ts: $8 \times ts \times 15232$<br>ODTU3.ts: $8 \times ts \times 15232$<br>ODTU4.ts: $8 \times ts \times 15200$<br>ODTU25.ts: $8 \times ts \times 15232$<br>ODTU50.ts: $8 \times ts \times 15232$ | ODTUCn.ts: $128 \times ts \times 952$                                                                                                             |
+| $P_{m,server}$        | OPU0: 15232<br>OPU1: 7616<br>OPU2: 1904<br>OPU3: 476<br>OPU4: 190                                                                                          | ODTU2.ts: 15232<br>ODTU3.ts: 15232<br>ODTU4.ts: 15200<br>ODTU25.ts: 15232<br>ODTU50.ts: 15232                                                                                                          | ODTUCn.ts: 952                                                                                                                                    |
+| $\Sigma C_{8D}$ range | OPU0: N/A<br>OPU1: 0 to +1<br>OPU2: 0 to +7<br>OPU3: 0 to +31<br>OPU4: 0 to +79                                                                            | ODTUk.1: N/A<br>ODTUk.2: 0 to +1<br>ODTUk.3: 0 to +2<br>ODTUk.4: 0 to +3<br>:<br>ODTUk.8: 0 to +7<br>:<br>ODTUk.32: 0 to +31<br>:                                                                      | ODTUCn.1: 0 to +15<br>ODTUCn.2: 0 to +31<br>ODTUCn.3: 0 to +47<br>ODTUCn.4: 0 to +59<br>:<br>ODTUCn.20n-1: 0 to +320n-1<br>ODTUCn.20n: 0 to +320n |
+
+**Table D.1 – OPUk, ODTUk.ts and ODTUCn.ts GMP parameter values**
+
+| GMP parameter                              | CBR client into OPUk                                                                    | ODUj into OPUk (ODTUk.ts)                | ODUk into OPUCn (ODTUCn.ts) |
+|--------------------------------------------|-----------------------------------------------------------------------------------------|------------------------------------------|-----------------------------|
+|                                            |                                                                                         | ODTUk.79: 0 to +78<br>ODTUk.80: 0 to +79 |                             |
+| $\sum C_{ID}$ range (for selected clients) | OPU0: 0 to +7<br>OPU1: 0 to +15<br>OPU2: 0 to +63<br>OPU3: 0 to +255<br>OPU4: 0 to +639 | Not applicable                           | Not applicable              |
+
+### D.3 $C_m(t)$ encoding and decoding
+
+$C_m(t)$  is encoded in the ODTUk.ts justification control bytes JC1, JC2 and JC3 specified in clause 19.4 for the 14-bit count and clause 20.4 for the 10-bit count field.
+
+$C_m(t)$  is an L-bit binary count of the number of groups of m OPU payload bits that carry m client bits; it has values between  $\text{Floor}(C_{m,\min})$  and  $\text{Ceiling}(C_{m,\max})$ , which are client specific. The  $C_i$  ( $i=1..L$ ) bits that comprise  $C_m(t)$  are used to indicate whether the  $C_m(t)$  value is incremented or decremented from the value in the previous frame, that is indicated by  $C_m(t-1)$ . Tables D.2 and D.3 show the inversion patterns for the  $C_i$  bits of  $C_m(t-1)$  that are inverted to indicate an increment or decrement of the  $C_m(t)$  value. Table D.2 shows the inversion patterns for the 14-bit count and Table D.3 shows the inversion patterns for the 10-bit count. An "1" entry in the table indicates an inversion of that bit.
+
+The bit inversion patterns apply to the  $C_m(t-1)$  value, prior to the increment or decrement operation that is signalled by the inversion pattern when  $|C_m(t) - C_m(t-1)| \leq 2$  (except  $C_m(t) - C_m(t-1) = 0$ ). The incremented or decremented  $C_m(t)$  value becomes the base value for the next GMP overhead transmission.
+
+- When  $0 < C_m(t) - C_m(t-1) \leq 2$ , indicating an increment of +1 or +2, a subset of the  $C_i$  bits containing  $C_m(t-1)$  is inverted as specified in Table D.2 or Table D.3 and the increment indicator (II) bit is set to 1.
+- When  $0 > C_m(t) - C_m(t-1) \geq -2$ , indicating a decrement of -1 or -2, a subset of  $C_i$  bits containing  $C_m(t-1)$  is inverted as specified in Table D.2 or Table D.3 and the decrement indicator (DI) bit is set to 1.
+- When the value of  $C_m(t)$  is changed with a value larger than +2 or -2 from the value of  $C_m(t-1)$ , both the II and DI bits are set to 1 and the  $C_i$  bits contain the new  $C_m(t)$  value. The associated CRC in JC3 verifies whether the  $C_m(t)$  value has been received correctly.
+- When the value of  $C_m(t)$  is unchanged from the value of  $C_m(t-1)$ , both the II and DI bits are set to 0.
+
+The above encoding process is illustrated in Figure D.6.
+
+**Table D.2 – 14-bit  $C_m(t)$  increment and decrement indicator patterns**
+
+| C1                                                                                   | C2 | C3 | C4 | C5 | C6 | C7 | C8 | C9 | C10 | C11 | C12 | C13 | C14 | II | DI | Change          |
+|--------------------------------------------------------------------------------------|----|----|----|----|----|----|----|----|-----|-----|-----|-----|-----|----|----|-----------------|
+| U                                                                                    | U  | U  | U  | U  | U  | U  | U  | U  | U   | U   | U   | U   | U   | 0  | 0  | 0               |
+| I                                                                                    | U  | I  | U  | I  | U  | I  | U  | I  | U   | I   | U   | I   | U   | 1  | 0  | +1              |
+| U                                                                                    | I  | U  | I  | U  | I  | U  | I  | U  | I   | U   | I   | U   | I   | 0  | 1  | -1              |
+| U                                                                                    | I  | I  | U  | U  | I  | I  | U  | U  | I   | I   | U   | U   | I   | 1  | 0  | +2              |
+| I                                                                                    | U  | U  | I  | I  | U  | U  | I  | I  | U   | U   | I   | I   | U   | 0  | 1  | -2              |
+| binary value                                                                         |    |    |    |    |    |    |    |    |     |     |     |     |     | 1  | 1  | More than +2/-2 |
+| <b>NOTE</b><br>– I indicates inverted $C_i$ bit<br>– U indicates unchanged $C_i$ bit |    |    |    |    |    |    |    |    |     |     |     |     |     |    |    |                 |
+
+The CRC-8 located in JC3 is calculated over the JC1 and JC2 bits. The CRC-8 uses the  $g(x) = x^8 + x^3 + x^2 + 1$  generator polynomial, and is calculated as follows:
+
+- 1) The JC1 and JC2 octets are taken in network octet order, most significant bit first, to form a 16-bit pattern representing the coefficients of a polynomial  $M(x)$  of degree 15.
+- 2)  $M(x)$  is multiplied by  $x^8$  and divided (modulo 2) by  $G(x)$ , producing a remainder  $R(x)$  of degree 7 or less.
+- 3) The coefficients of  $R(x)$  are considered to be an 8-bit sequence, where  $x^7$  is the most significant bit.
+- 4) This 8-bit sequence is the CRC-8 where the first bit of the CRC-8 to be transmitted is the coefficient of  $x^7$  and the last bit transmitted is the coefficient of  $x^0$ .
+
+The de-mapper process performs steps 1-3 in the same manner as the mapper process, except that here, the  $M(x)$  polynomial of step 1 includes the CRC bits of JC3, resulting in  $M(x)$  having degree 23. In the absence of bit errors, the remainder shall be 0000 0000.
+
+**Table D.3 – 10-bit  $C_m(t)$  increment and decrement indicator patterns**
+
+| C1                                                                                   | C2 | C3 | C4 | C5 | C6 | C7 | C8 | C9 | C10 | II | DI | Change          |
+|--------------------------------------------------------------------------------------|----|----|----|----|----|----|----|----|-----|----|----|-----------------|
+| U                                                                                    | U  | U  | U  | U  | U  | U  | U  | U  | U   | 0  | 0  | 0               |
+| I                                                                                    | U  | I  | U  | I  | U  | I  | U  | I  | U   | 1  | 0  | +1              |
+| I                                                                                    | U  | U  | I  | U  | I  | I  | U  | U  | I   | 0  | 1  | -1              |
+| U                                                                                    | I  | U  | I  | I  | U  | U  | I  | U  | I   | 1  | 0  | +2              |
+| U                                                                                    | I  | I  | U  | U  | I  | U  | I  | I  | U   | 0  | 1  | -2              |
+| binary value                                                                         |    |    |    |    |    |    |    |    |     | 1  | 1  | More than +2/-2 |
+| <b>NOTE</b><br>– I indicates inverted $C_i$ bit<br>– U indicates unchanged $C_i$ bit |    |    |    |    |    |    |    |    |     |    |    |                 |
+
+The CRC-6 located in JC3 is calculated over bits 3-8 of JC1 and JC2 (i.e., the bits containing the GMP overhead value shown in Table D.3). The CRC-6 uses the  $g(x) = x^6 + x^3 + x^2 + 1$  generator polynomial, and is calculated as follows:
+
+- 1) The JC1 and JC2 octets are taken in network octet order, most significant bit first, such that bit 3 of JC1 through bit 8 of JC2 form a 12-bit pattern representing the coefficients of a polynomial  $M(x)$  of degree 11.
+- 2)  $M(x)$  is multiplied by  $x^6$  and divided (modulo 2) by  $G(x)$ , producing a remainder  $R(x)$  of degree 5 or less.
+- 3) The coefficients of  $R(x)$  are considered to be a 6-bit sequence, where  $x^5$  is the most significant bit.
+- 4) This 6-bit sequence is the CRC-6 where the first bit of the CRC-6 to be transmitted is the coefficient of  $x^5$  and the last bit transmitted is the coefficient of  $x^0$ .
+
+The de-mapper process performs steps 1-3 in the same manner as the mapper process, except that here, the  $M(x)$  polynomial of step 1 includes the CRC bits of JC3, resulting in  $M(x)$  having degree 17. In the absence of bit errors, the remainder shall be 000000.
+
+![Flowchart for JC1, JC2 and JC3 generation. The process starts with 'Determine the required Cm'. It then enters a loop: 'Increment by +1 or +2?' (Y leads to 'Set II', N leads to 'Decrement by -1 or -2?'). 'Decrement by -1 or -2?' (Y leads to 'Set DI', N leads to '| Cm(t) - Cm(t-1) | > 2?'). '| Cm(t) - Cm(t-1) | > 2?' (Y leads to 'Accept new Cm(t)' -> 'Set II and DI', N loops back to start). 'Set II' leads to 'Increment by 1?' (Y leads to 'Set +1 increment pattern to the value of Cm(t-1)', N leads to 'Set +2 increment pattern to the value of Cm(t-1)'). 'Set DI' leads to 'Decrement by 1?' (Y leads to 'Set -1 decrement pattern to the value of Cm(t-1)', N leads to 'Set -2 decrement pattern to the value of Cm(t-1)'). All pattern-setting boxes lead to 'Calculate and insert CRC' -> 'Insert into JC1-JC3 bytes'.](c24f22afc8106a8f9b76c759a1db6891_img.jpg)
+
+```
+
+graph TD
+    Start(( )) --> A[Determine the required Cm]
+    A --> B{Increment by +1 or +2?}
+    B -- Y --> C[Set II]
+    B -- N --> D{Decrement by -1 or -2?}
+    D -- Y --> E[Set DI]
+    D -- N --> F{| Cm(t) - Cm(t-1) | > 2?}
+    F -- Y --> G[Accept new Cm(t)]
+    G --> H[Set II and DI]
+    F -- N --> A
+    C --> I{Increment by 1?}
+    I -- Y --> J[Set +1 increment pattern to the value of Cm(t-1)]
+    I -- N --> K[Set +2 increment pattern to the value of Cm(t-1)]
+    E --> L{Decrement by 1?}
+    L -- Y --> M[Set -1 decrement pattern to the value of Cm(t-1)]
+    L -- N --> N1[Set -2 decrement pattern to the value of Cm(t-1)]
+    J --> O[Calculate and insert CRC]
+    K --> O
+    M --> O
+    N1 --> O
+    O --> P[Insert into JC1-JC3 bytes]
+    H --> O
+  
+```
+
+Flowchart for JC1, JC2 and JC3 generation. The process starts with 'Determine the required Cm'. It then enters a loop: 'Increment by +1 or +2?' (Y leads to 'Set II', N leads to 'Decrement by -1 or -2?'). 'Decrement by -1 or -2?' (Y leads to 'Set DI', N leads to '| Cm(t) - Cm(t-1) | > 2?'). '| Cm(t) - Cm(t-1) | > 2?' (Y leads to 'Accept new Cm(t)' -> 'Set II and DI', N loops back to start). 'Set II' leads to 'Increment by 1?' (Y leads to 'Set +1 increment pattern to the value of Cm(t-1)', N leads to 'Set +2 increment pattern to the value of Cm(t-1)'). 'Set DI' leads to 'Decrement by 1?' (Y leads to 'Set -1 decrement pattern to the value of Cm(t-1)', N leads to 'Set -2 decrement pattern to the value of Cm(t-1)'). All pattern-setting boxes lead to 'Calculate and insert CRC' -> 'Insert into JC1-JC3 bytes'.
+
+G.709-Y.1331(16)\_FD.6
+
+Figure D.6 – JC1, JC2 and JC3 generation
+
+A parallel logic implementation of the source CRC-8 and CRC-6 are illustrated in Appendix VI.
+
+The GMP sink synchronizes its  $C_m(t)$  value to the GMP source through the following process, which is illustrated in Figure D.7 and the equivalent process in Figure D.8.
+
+When the received JC octets contain  $II = DI$  and a valid CRC-8, the GMP sink accepts the received C1-CL as its  $C_m(t)$  value for the next frame. At this point the GMP sink is synchronized to the GMP source. When  $II \neq DI$  with a valid CRC in the current received frame (frame  $i$ ), the GMP sink must examine the received JC octets in the next frame (frame  $i+1$ ) in order to obtain  $C_m(t)$  synchronization.  $II \neq DI$  in frame  $i$  indicates that the source is performing a count increment or decrement operation that will modify the  $C_m(t)$  value it sends in frame  $i+1$ . Since this modification to the  $C_m(t)$  will affect the count LSBs, the GMP sink uses the LSBs,  $II$ , and  $DI$  in frame  $i$  to determine its synchronization hunt state when it receives frame  $i+1$ . Specifically, in Figure D.7, the Hunt state (A-F) is determined using C13, C14,  $II$  and  $DI$  for the 14-bit count and C9, C10,  $II$  and  $DI$  for the 10-bit count. Equivalently, in Figure D.8, the Hunt state (A or B) is determined using C14,  $II$ , and  $DI$  for the 14-bit count and C10,  $II$ , and  $DI$  for the 10-bit count. If  $II = DI$  with a valid CRC in frame  $i+1$ ,  $C_m(t)$  synchronization is achieved by directly accepting the received C1-CL as the new  $C_m(t)$ . If  $II \neq DI$  with a valid CRC in frame  $i+1$ , the sink uses the new LSBs,  $II$  and  $DI$  values to determine whether the source is communicating an increment or decrement operation and the magnitude of the increment/decrement step. This corresponds to the transition to the lower row of states (the "S" states) in Figure D.7 and Figure D.8. At this point, the GMP sink has identified the type of increment or decrement operation that is being signalled in frame  $i+1$ . As shown in Figure D.9, the sink then applies the appropriate bit inversion pattern from Table D.2 to the received C1-C14 field or the bit inversion pattern from Table D.3 to the received C1-C10 field to determine the transmitted  $C_m(t)$  value. Synchronization has now been achieved since the GMP sink has determined the current  $C_m(t)$  and knows the expected  $C_m(t)$  change in frame  $i+2$ .
+
+![State transition diagram for GMP sink count synchronization. The diagram shows a 'Start hunt' state at the top with a self-loop labeled 'xxxxB'. Below it are six 'Hunt' states (A-F) and five 'S' states (S+2, S+1, Accept received Cm, S-1, S-2). Transitions are labeled with input/output pairs like '0110G/1110G' or 'xxxxB'. All 'S' states lead to a 'Synchronized' state at the bottom. A label 'G.709-Y.1331(16)_FD.7' is in the bottom right.](b855c771b0a7133300a578d48a2d79d9_img.jpg)
+
+Inputs = c13, c14, II, DI, CRC for 14-bit  $C_m$   
+Inputs = c9, c10, II, DI, CRC for 10-bit  $C_m$
+
+G.709-Y.1331(16)\_FD.7
+
+State transition diagram for GMP sink count synchronization. The diagram shows a 'Start hunt' state at the top with a self-loop labeled 'xxxxB'. Below it are six 'Hunt' states (A-F) and five 'S' states (S+2, S+1, Accept received Cm, S-1, S-2). Transitions are labeled with input/output pairs like '0110G/1110G' or 'xxxxB'. All 'S' states lead to a 'Synchronized' state at the bottom. A label 'G.709-Y.1331(16)\_FD.7' is in the bottom right.
+
+**Figure D.7 – GMP sink count synchronization process representation using the two least significant bits of the count as inputs**
+
+Optimization has shown that Figure D.8 provides the same function. Either one can be chosen. For historical reasons both are kept.
+
+![State machine diagram for GMP sink count synchronization. It starts at 'Start hunt' with a self-loop 'xxxB'. Transitions to 'Hunt-A' and 'Hunt-B' are labeled '101G 010G xxxB' and '110G 001G xxxB' respectively. From 'Hunt-A' and 'Hunt-B', multiple transitions (010G, 110G, x00G, x11G, 001G, 101G) lead to intermediate states 'S+2', 'S+1', 'Accept received Cm', 'S-1', and 'S-2'. All these states lead to the final 'Synchronized' state. A vertical transition from 'Start hunt' is labeled 'x00G x11G'. A reference code 'G.709-Y.1331(16)-Cor.1(17)_FD.8' is at the bottom right.](6726e50ea08adfda77603ec4afa549e1_img.jpg)
+
+Inputs = C14, II, DI, CRC for the 14-bit count  
+ Inputs = C10, II, DI, CRC for the 10-bit count
+
+G.709-Y.1331(16)-Cor.1(17)\_FD.8
+
+State machine diagram for GMP sink count synchronization. It starts at 'Start hunt' with a self-loop 'xxxB'. Transitions to 'Hunt-A' and 'Hunt-B' are labeled '101G 010G xxxB' and '110G 001G xxxB' respectively. From 'Hunt-A' and 'Hunt-B', multiple transitions (010G, 110G, x00G, x11G, 001G, 101G) lead to intermediate states 'S+2', 'S+1', 'Accept received Cm', 'S-1', and 'S-2'. All these states lead to the final 'Synchronized' state. A vertical transition from 'Start hunt' is labeled 'x00G x11G'. A reference code 'G.709-Y.1331(16)-Cor.1(17)\_FD.8' is at the bottom right.
+
+**Figure D.8 – GMP sink count synchronization process diagram**
+
+| 14-bit count |                                                                                                 |
+|--------------|-------------------------------------------------------------------------------------------------|
+| S state      | Interpretation/Action                                                                           |
+| S+2          | Count = C1-C14 after inverting C2, C3, C6, C7, C10, C11, & C14; Increment +2 for the next frame |
+| S+1          | Count = C1-C14 after inverting C1, C3, C5, C7, C9, C11, & C13; Increment +1 for the next frame  |
+| S-1          | Count = C1-C14 after inverting C2, C4, C6, C8, C10, C12, & C14; Decrement -1 for next frame     |
+| S-2          | Count = C1-C14 after inverting C1, C4, C5, C8, C9, C12, C13; Decrement -2 for next frame        |
+
+| 10-bit count |                                                                                      |
+|--------------|--------------------------------------------------------------------------------------|
+| S state      | Interpretation/Action                                                                |
+| S+2          | Count = C1-C10 after inverting C2, C4, C5, C8 & C10; Increment +2 for the next frame |
+| S+1          | Count = C1-C10 after inverting C1, C3, C5, C7 & C9; Increment +1 for the next frame  |
+| S-1          | Count = C1-C10 after inverting C1, C4, C6, C7 & C10; Decrement -1 for next frame     |
+| S-2          | Count = C1-C10 after inverting C2, C3, C6, C8 & C9; Decrement -2 for next frame      |
+
+**Figure D.9 – "S"-state interpretation for Figures D.7 and D.8**
+
+Note that the state machine of Figure D.7 or Figure D.8 can also be used for off-line synchronization checking.
+
+When the GMP sink has synchronized its  $C_m(t)$  value to the GMP source, it interprets the received JC octets according to the following principles:
+
+- When the CRC is good and  $II = DI$ , the GMP sink accepts the received  $C_m(t)$  value.
+- When the CRC is good and  $II \neq DI$ , the GMP sink compares the received  $C_m(t)$  value to its expected  $C_m(t)$  value to determine the difference between these values. This difference is compared to the bit inversion patterns of Table D.2 or Table D.3 to determine the increment or decrement operation sent by the source and updates its  $C_m(t)$  accordingly. Since the CRC is good, the sink can use either JC1 or JC2 for this comparison.
+- When the CRC is bad, the GMP sink compares the received  $C_m(t)$  value to its expected  $C_m(t)$  value. The sink then compares the difference between these values, per Table D.2 or Table D.3, to the valid bit inversion patterns in JC1, and the bit inversion,  $II$  and  $DI$  pattern in JC2.
+  - If JC1 contains a valid pattern and JC2 does not, the sink accepts the corresponding increment or decrement indication from JC1 and updates its  $C_m(t)$  accordingly.
+  - If JC2 contains a valid pattern and JC1 does not, the sink accepts the corresponding increment or decrement indication from JC2 and updates its  $C_m(t)$  accordingly.
+  - If both JC1 and JC2 contain valid patterns indicating the same increment or decrement operation, this indication is accepted and the sink updates its  $C_m(t)$  accordingly.
+  - If neither JC1 nor JC2 contain valid patterns, the sink shall keep its current count value and begin the search for synchronization.
+
+NOTE – If JC1 and JC2 each contain valid patterns that are different from each other, the receiver can either keep the current  $C_m(t)$  value and begin a synchronization search, or it can use the CRC to determine whether JC1 or JC2 contains the correct pattern.
+
+The GMP sink uses the updated  $C_m(t)$  value to extract the client data from the next OPU frame or ODTUk.ts multiframe.
+
+#### D.4 $\Sigma C_{nD}(t)$ encoding and decoding
+
+##### D.4.1 $\Sigma C_{nD}(t)$ encoding and decoding for OPUk
+
+The cumulative value of  $C_{nD}(t)$  ( $\Sigma C_{nD}(t)$ ) is encoded in bits 4-8 of the OPUk and ODTUk.ts justification control bytes JC4, JC5 and JC6. Bits D1 to D10 in JC4 and JC5 carry the value of  $\Sigma C_{nD}(t)$ . Bit D1 carries the most significant bit and bit D10 carries the least significant bit.
+
+The CRC-5 located in JC6 is calculated over the D1-D10 bits in JC4 and JC5. The CRC-5 uses the  $g(x) = x^5 + x + 1$  generator polynomial, and is calculated as follows:
+
+- 1) The JC4 bits 4-8 and JC5 bits 4-8 octets are taken in network transmission order, most significant bit first, to form a 10-bit pattern representing the coefficients of a polynomial  $M(x)$  of degree 9.
+- 2)  $M(x)$  is multiplied by  $x^5$  and divided (modulo 2) by  $G(x)$ , producing a remainder  $R(x)$  of degree 4 or less.
+- 3) The coefficients of  $R(x)$  are considered to be a 5-bit sequence, where  $x^4$  is the most significant bit.
+- 4) This 5-bit sequence is the CRC-5 where the first bit of the CRC-5 to be transmitted is the coefficient of  $x^4$  and the last bit transmitted is the coefficient of  $x^0$ .
+
+The de-mapper process performs steps 1-3 in the same manner as the mapper process, except that here, the  $M(x)$  polynomial of step 1 includes the CRC bits of JC6, resulting in  $M(x)$  having degree 14. In the absence of bit errors, the remainder shall be 00000.
+
+A parallel logic implementation of the source CRC-5 is illustrated in Appendix VI.
+
+#### D.4.2 $\Sigma C_{\text{nd}}(t)$ encoding and decoding for OPU $C_n$
+
+The cumulative value of  $C_{\text{nd}}(t)$  ( $\Sigma C_{\text{nd}}(t)$ ) is encoded in the ODTUC $n$ .ts justification control bytes JC1, JC2, JC3, JC4, JC5 and JC6. Bits D1 to D18 carry the value of  $\Sigma C_{\text{nd}}(t)$ . Bit D1 carries the most significant bit and bit D18 carries the least significant bit. As shown in Figure 20-7, bits D1 to D7 are located in bits 2-8 of JC4, bits D8 to D9 are located in bits 1-2 of JC1, bits D10 to D16 are located in JC5, and bits D17 to D18 are located in bits 1-2 of JC2.
+
+The CRC-9 located in bits 2-8 of JC6 and bits 1-2 of JC3 is calculated over the D1-D18 bits in JC4, JC1, JC5 and JC2. The CRC-9 uses the  $g(x) = x^9 + x^3 + x^2 + 1$  generator polynomial, and is calculated as follows:
+
+- 1) The JC4 bits 2-8, JC1 bits 1-2, JC5 bits 2-8, and JC2 bits 1-2 are taken in network transmission order, most significant bit first, to form an 18-bit pattern representing the coefficients of a polynomial  $M(x)$  of degree 17.
+- 2)  $M(x)$  is multiplied by  $x^9$  and divided (modulo 2) by  $G(x)$ , producing a remainder  $R(x)$  of degree 8 or less.
+- 3) The coefficients of  $R(x)$  are considered to be a 9-bit sequence, where  $x^8$  is the most significant bit.
+- 4) This 9-bit sequence is the CRC-9 where the first bit of the CRC-9 to be transmitted is the coefficient of  $x^8$  and the last bit transmitted is the coefficient of  $x^0$ .
+
+The de-mapper process performs steps 1-3 in the same manner as the mapper process, except that here, the  $M(x)$  polynomial of step 1 includes the CRC bits of JC6 and JC3, resulting in  $M(x)$  having degree 26. In the absence of bit errors, the remainder shall be 000000000.
+
+A parallel logic implementation of the source CRC-9 is illustrated in Appendix VI.
+
+## Annex E
+
+### Adaptation of parallel 64B/66B encoded clients
+
+(This annex forms an integral part of this Recommendation.)
+
+#### E.1 Introduction
+
+IEEE 40GBASE-R and 100GBASE-R interfaces specified in [IEEE 802.3] are parallel interfaces intended for short-reach (up to 40 km) interconnection of Ethernet equipment. This annex describes the process of converting the parallel format of these interfaces into a serial bit stream to be carried over the OTN.
+
+The order of transmission of information in all the diagrams in this annex is first from left to right and then from top to bottom.
+
+#### E.2 Clients signal format
+
+40GBASE-R and 100GBASE-R clients are initially parallel interfaces, but in the future they may be serial interfaces. Independent of whether these interfaces are parallel or serial, or what the parallel interface lane count is, 40GBASE-R signals are comprised of four PCS lanes, and 100GBASE-R signals are comprised of twenty PCS lanes. If the number of physical lanes on the interface is fewer than the number of PCS lanes, the appropriate number of PCS lanes is bit-multiplexed onto each physical lane of the interface. Each PCS lane consists of 64B/66B encoded data with a PCS lane alignment marker inserted on each lane once per 16384 66-bit blocks. The PCS lane alignment marker itself is a special format 66B codeword.
+
+The use of this adaptation for 40GBASE-R into OPU3 also applies the transcoding method that appears in Annex B and the framing method of Annex F. The adaptation described in this annex alone can be used for the adaptation of 100GBASE-R into OPU4.
+
+#### E.3 Client frame recovery
+
+Client framing recovery consists of the following:
+
+- bit-disinterleave the PCS lanes, if necessary. This is necessary whenever the number of PCS lanes and the number of physical lanes is not equal, and is not necessary when they are equal (e.g., a 4-lane 40GBASE-R interface);
+- recover 64B/66B block lock as per the state diagram in Figure 82-10 of [IEEE 802.3];
+- recover lane alignment marker framing on each PCS lane as per the state diagram in Figure 82-11 of [IEEE 802.3];
+- reorder and de-skew the PCS lanes into a serialized stream of 66B blocks (including lane alignment markers). Figure E.1 illustrates the ordering of 66B blocks after the completion of this process for an interface with  $p$  PCS lanes.
+
+![Diagram of de-skewed/serialized stream of 66B blocks showing transmission order. The stream consists of Lane Markers 1 through p, followed by a block of p x 16383 66B blocks, then repeating the Lane Markers 1 through p, and finally another block of p x 16383 66B blocks.](f117583d264d1fa4b9c67c44879bb3e7_img.jpg)
+
+Transmission order  
+↓
+
+|                  |                                |
+|------------------|--------------------------------|
+| 1                | Lane Marker 1                  |
+| 2                | Lane Marker 2                  |
+| :                | :                              |
+| $p$              | Lane Marker $p$                |
+| $p + 1$          | $p \times 16383$<br>66B blocks |
+| $p \times 16384$ |                                |
+|                  | Lane Marker 1                  |
+|                  | Lane Marker 2                  |
+|                  | :                              |
+|                  | Lane Marker $p$                |
+|                  | $p \times 16383$<br>66B blocks |
+
+0 65 → Transmission order
+
+G.709-Y.1331(20)\_FE.1
+
+Diagram of de-skewed/serialized stream of 66B blocks showing transmission order. The stream consists of Lane Markers 1 through p, followed by a block of p x 16383 66B blocks, then repeating the Lane Markers 1 through p, and finally another block of p x 16383 66B blocks.
+
+**Figure E.1 – De-skewed/serialized stream of 66B blocks**
+
+Each 66B codeword is one of the following:
+
+- a set of eight data bytes with a sync header of "01";
+- a control block (possibly including seven or fewer data octets) beginning with a sync header of "10";
+- a PCS lane alignment marker, also encoded with a sync header of "10". Of the 8 octets following the sync header, 6 octets have fixed values allowing the PCS lane alignment markers to be recognized (see Tables E.1 and E.2). The fourth octet following the sync header is a BIP-8 calculated over the data from one alignment marker to the next as defined in Table 82-4 of [IEEE 802.3]. The eighth octet is the complement of this BIP-8 value to maintain DC balance. Note that the intended operation is to pass these BIP-8 values transparently as they are used for monitoring the error ratio of the Ethernet link between Ethernet PCS sublayers. For the case of 100GBASE-R, the BIP-8 values are not manipulated by the mapping or de-mapping procedure. For the case of 40GBASE-R, a BIP-8 compensation is done as described in clause E.4.1.
+
+For all-data blocks and control blocks, the 64 bits following the sync header are scrambled as a continuous bit-stream (skipping sync headers and PCS lane alignment markers) according to the polynomial  $G(x) = 1 + x^{39} + x^{58}$ .
+
+After 64B/66B block lock recovery as per the state diagram in Figure 82-10 of [IEEE 802.3] to the single-lane received aggregate signal, these 66B blocks are re-distributed to PCS lanes at the egress interface. The 66B blocks (including PCS lane alignment markers) resulting from the decoding process are distributed round-robin to PCS lanes. If the number of PCS lanes is greater than the number of physical lanes of the egress interface, the appropriate numbers of PCS lanes are bit-multiplexed onto the physical lanes of the egress interface.
+
+### E.3.1 40GBASE-R client frame recovery
+
+PCS lane alignment markers have the values shown in Table E.1 for 40GBASE-R signals which use PCS lane numbers 0-3.
+
+**Table E.1 – PCS lane alignment marker format for 40GBASE-R**
+
+| Lane Number | SH | Encoding { <u>M<sub>0</sub></u> , <u>M<sub>1</sub></u> , <u>M<sub>2</sub></u> , <u>BIP<sub>3</sub></u> , <u>M<sub>4</sub></u> , <u>M<sub>5</sub></u> , <u>M<sub>6</sub></u> , <u>BIP<sub>7</sub></u> } |
+|-------------|----|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| 0           | 10 | 0x90, 0x76, 0x47, BIP <sub>3</sub> , 0x6f, 0x89, 0xb8, BIP <sub>7</sub>                                                                                                                                |
+| 1           | 10 | 0xf0, 0xc4, 0xe6, BIP <sub>3</sub> , 0x0f, 0x3b, 0x19, BIP <sub>7</sub>                                                                                                                                |
+| 2           | 10 | 0xc5, 0x65, 0x9b, BIP <sub>3</sub> , 0x3a, 0x9a, 0x64, BIP <sub>7</sub>                                                                                                                                |
+| 3           | 10 | 0xa2, 0x79, 0x3d, BIP <sub>3</sub> , 0x5d, 0x86, 0xc2, BIP <sub>7</sub>                                                                                                                                |
+
+Since a 40GBASE-R client signal must be transcoded into 1024B/1027B for rate reduction, the 64B/66B PCS receive process at the ingress interface further descrambles the bit-stream skipping sync headers and PCS lane alignment markers, and the 64B/66B PCS transmit process at the egress interface scrambles the bit-stream again skipping sync headers and PCS lane alignment markers, as shown in Figure E.1.
+
+### E.3.2 100GBASE-R client frame recovery
+
+PCS lane alignment markers have the values shown in Table E.2 for 100GBASE-R signals which use PCS lane numbers 0-19.
+
+The lane alignment markers transported over the OPU4 are distributed unchanged to the PCS lanes.
+
+**Table E.2 – PCS lane alignment marker format for 100GBASE-R**
+
+| Lane Number | SH | Encoding { <u>M<sub>0</sub></u> , <u>M<sub>1</sub></u> , <u>M<sub>2</sub></u> , <u>BIP<sub>3</sub></u> , <u>M<sub>4</sub></u> , <u>M<sub>5</sub></u> , <u>M<sub>6</sub></u> , <u>BIP<sub>7</sub></u> } | Lane Number | SH | Encoding { <u>M<sub>0</sub></u> , <u>M<sub>1</sub></u> , <u>M<sub>2</sub></u> , <u>BIP<sub>3</sub></u> , <u>M<sub>4</sub></u> , <u>M<sub>5</sub></u> , <u>M<sub>6</sub></u> , <u>BIP<sub>7</sub></u> } |
+|-------------|----|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------|----|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| 0           | 10 | 0xc1, 0x68, 0x21, BIP <sub>3</sub> , 0x3e, 0x97, 0xde, BIP <sub>7</sub>                                                                                                                                | 10          | 10 | 0xfd, 0x6c, 0x99, BIP <sub>3</sub> , 0x02, 0x93, 0x66, BIP <sub>7</sub>                                                                                                                                |
+| 1           | 10 | 0x9d, 0x71, 0x8e, BIP <sub>3</sub> , 0x62, 0x8e, 0x71, BIP <sub>7</sub>                                                                                                                                | 11          | 10 | 0xb9, 0x91, 0x55, BIP <sub>3</sub> , 0x46, 0x6e, 0xaa, BIP <sub>7</sub>                                                                                                                                |
+| 2           | 10 | 0x59, 0x4b, 0xe8, BIP <sub>3</sub> , 0xa6, 0xb4, 0x17, BIP <sub>7</sub>                                                                                                                                | 12          | 10 | 0x5c, 0xb9, 0xb2, BIP <sub>3</sub> , 0xa3, 0x46, 0x4d, BIP <sub>7</sub>                                                                                                                                |
+| 3           | 10 | 0x4d, 0x95, 0x7b, BIP <sub>3</sub> , 0xb2, 0x6a, 0x84, BIP <sub>7</sub>                                                                                                                                | 13          | 10 | 0x1a, 0xf8, 0xbd, BIP <sub>3</sub> , 0xe5, 0x07, 0x42, BIP <sub>7</sub>                                                                                                                                |
+| 4           | 10 | 0xf5, 0x07, 0x09, BIP <sub>3</sub> , 0x0a, 0xf8, 0xf6, BIP <sub>7</sub>                                                                                                                                | 14          | 10 | 0x83, 0xc7, 0xca, BIP <sub>3</sub> , 0x7c, 0x38, 0x35, BIP <sub>7</sub>                                                                                                                                |
+| 5           | 10 | 0xdd, 0x14, 0xc2, BIP <sub>3</sub> , 0x22, 0xeb, 0x3d, BIP <sub>7</sub>                                                                                                                                | 15          | 10 | 0x35, 0x36, 0xcd, BIP <sub>3</sub> , 0xca, 0xc9, 0x32, BIP <sub>7</sub>                                                                                                                                |
+| 6           | 10 | 0x9a, 0x4a, 0x26, BIP <sub>3</sub> , 0x65, 0xb5, 0xd9, BIP <sub>7</sub>                                                                                                                                | 16          | 10 | 0xc4, 0x31, 0x4c, BIP <sub>3</sub> , 0x3b, 0xce, 0xb3, BIP <sub>7</sub>                                                                                                                                |
+| 7           | 10 | 0x7b, 0x45, 0x66, BIP <sub>3</sub> , 0x84, 0xba, 0x99, BIP <sub>7</sub>                                                                                                                                | 17          | 10 | 0xad, 0xd6, 0xb7, BIP <sub>3</sub> , 0x52, 0x29, 0x48, BIP <sub>7</sub>                                                                                                                                |
+| 8           | 10 | 0xa0, 0x24, 0x76, BIP <sub>3</sub> , 0x5f, 0xdb, 0x89, BIP <sub>7</sub>                                                                                                                                | 18          | 10 | 0x5f, 0x66, 0x2a, BIP <sub>3</sub> , 0xa0, 0x99, 0xd5, BIP <sub>7</sub>                                                                                                                                |
+| 9           | 10 | 0x68, 0xc9, 0xfb, BIP <sub>3</sub> , 0x97, 0x36, 0x04, BIP <sub>7</sub>                                                                                                                                | 19          | 10 | 0xc0, 0xf0, 0xe5, BIP <sub>3</sub> , 0x3f, 0x0f, 0x1a, BIP <sub>7</sub>                                                                                                                                |
+
+#### **E.4 Additions to Annex B transcoding for parallel 40GBASE-R clients**
+
+Mapping 40GBASE-R clients into OPU3 requires the transcoding into 513B code blocks described in Annex B. This clause describes the additions to the Annex B transcoding process for transport of PCS lane alignment markers.
+
+Ethernet path monitoring is the kind of behaviour that is desirable in the case where the Ethernet equipment and the OTN equipment are in different domains (e.g., customer and service provider) and from the standpoint of the Ethernet equipment. It is also the default behaviour which would result from the current mapping of 100GBASE-R where the 66B blocks would be mapped into the OPU4 container after management of skew. It may also be perceived as a transparency requirement that BIP-8 work end-to-end. Additional functionality as described below has to be built in to allow BIP-8 transparency for 40GBASE-R client signals.
+
+PCS lane alignment markers are encoded together with 66B control blocks into the uppermost rows of the 513B code block shown in Figure B.3. The flag bit "F" of the 513B structure is 1 if the 513B structure contains at least one 66B control block or PCS lane alignment marker, and 0 if the 513B structure contains eight all-data 66B blocks.
+
+The transcoding into 512B/513B must encode PCS lane alignment marker into a row of the structure shown in Figure B.3 as follows: The sync header of "10" is removed. The received M<sub>0</sub>, M<sub>1</sub> and M<sub>2</sub> bytes of the PCS alignment marker encodings as shown in Table E.1 are used to forward the lane number information. The first byte of the row will contain the structure shown in Figure B.4, with a CB-TYPE field of "0100". The POS field will indicate the position where the PCS lane alignment marker was received among the group of eight 66B codewords being encoded into this 513B block. The flag continuation bit "FC" will indicate whether any other 66B control blocks or PCS lane alignment markers are encoded into rows below this one in the 513B block. Beyond this first byte, the next four bytes of the row are populated with the received M<sub>0</sub>, M<sub>1</sub>, M<sub>2</sub> and ingress BIP<sub>3</sub> bytes of the PCS alignment marker encodings at the encoder. At the decoder, a PCS lane alignment marker will be generated in the position indicated by the POS field among any 66B all-data blocks contained in this 513B block, the sync header of "10" is generated followed by the received M<sub>0</sub>, M<sub>1</sub> and M<sub>2</sub> bytes, the egress BIP<sub>3</sub> byte, the bytes M<sub>4</sub>, M<sub>5</sub> and M<sub>6</sub> which are the bit-wise inverted M<sub>0</sub>, M<sub>1</sub> and M<sub>2</sub> bytes received at the decoder, and the egress BIP<sub>7</sub> byte which is the bit-wise inverted egress BIP<sub>3</sub> byte.
+
+It will then be up to the Ethernet receiver to handle bit errors within the OTN section that might have altered the PCS alignment marker encodings (for details refer to clause 82.2.18.3 and Figure 82-11 in [IEEE 802.3]).
+
+The egress BIP<sub>3</sub> and the egress BIP<sub>7</sub> bytes are calculated as described in clause E.4.1.
+
+Figure E.2 below shows the transcoded lane marker format.
+
+![](180f1fb534ad2c1d918ede57612b3fb0_img.jpg)
+
+|                          |     |  |   |   |   |   |    |                      |  |  |    |                |  |  |    |
+|--------------------------|-----|--|---|---|---|---|----|----------------------|--|--|----|----------------|--|--|----|
+| 0                        | 1   |  | 3 | 4 | 5 | 6 | 7  | 8                    |  |  | 11 | 12             |  |  | 15 |
+| FC                       | POS |  | 0 | 1 | 0 | 0 |    |                      |  |  |    | M <sub>0</sub> |  |  |    |
+| 16                       |     |  |   |   |   |   | 23 | 24                   |  |  |    |                |  |  | 31 |
+| M <sub>1</sub>           |     |  |   |   |   |   |    | M <sub>2</sub>       |  |  |    |                |  |  |    |
+| 32                       |     |  |   |   |   |   | 39 | 40                   |  |  |    |                |  |  | 47 |
+| ingress BIP <sub>3</sub> |     |  |   |   |   |   |    | PCS BIP-8 error mask |  |  |    |                |  |  |    |
+| 48                       |     |  |   |   |   |   | 55 | 56                   |  |  |    |                |  |  | 63 |
+| OTN BIP-8                |     |  |   |   |   |   |    | 0×FF                 |  |  |    |                |  |  |    |
+
+G.709-Y.1331(20)\_FE.2
+
+**Figure E.2 – Transcoded lane marker format**
+
+#### E.4.1 40GBASE-R BIP-8 transparency
+
+The transcoding method used for 40GBASE-R is timing and PCS codeword transparent. In normal operation, the only aspects of the PCS encoded bitstream that are not preserved given the mapping described in annexes B, E and F are for one the scrambling, since the scrambler does not begin with a known state and multiple different encoded bitstreams can represent the same PCS encoded content, and secondly the BIP-8 value in the Ethernet path or more precisely, the bit errors that occur between the Ethernet transmitter and the ingress point of the OTN domain and within the OTN domain. The BIP-8 values can be preserved with the scheme described below. As the scrambling itself does not contain any information that has to be preserved, no effort has been made to synchronize the scrambler states between OTN ingress and OTN egress.
+
+Unfortunately, since the BIP-8 is calculated on the scrambled bitstream, a simple transport of the BIP-8 across the OTN domain in the transcoded lane marker will not result in a BIP-8 value that is meaningful for detecting errors in the received, descrambled, transcoded, trans-decoded, and then rescrambled bit stream.
+
+To preserve the bit errors between the Ethernet transmitter and the egress side of the OTN domain, the bit-error handling is divided into two processes, one that takes place at the OTN ingress side, or encoder, and one on the OTN egress side, or decoder.
+
+At the OTN ingress an 8-bit error mask is calculated by generating the expected BIP-8 for each PCS lane and XORing this value with the received BIP-8. This error mask will have a "1" for each bit of the BIP-8 which is wrong, and a "0" for each bit which is correct. This value is shown as a PCS BIP-8 error mask in Figure E.2.
+
+In the event no errors are introduced across the OTN (as an FEC protected network can be an essentially zero error environment), the PCS BIP-8 error mask can be used to adjust the newly calculated PCS BIP-8 at the egress providing a reliable indication of the number of errors that are introduced across the full Ethernet path. If errors are introduced across the OTN, this particular BIP-8 calculation algorithm will not see these errors.
+
+To overcome this situation, a new BIP-8 per lane for the OTN section is introduced. In the following this new BIP-8 will be identified as OTN BIP-8 in order to distinguish it from the PCS BIP-8.
+
+It should be noted that the term OTN BIP-8 does not refer to and should not be confused with the BIP-8 defined in the OTUk overhead (byte SM[2]).
+
+The OTN BIP-8 is calculated similarly to the PCS BIP-8 as described in clause 82.2.8 of [IEEE 802.3] with the exception that the calculation will be done over unscrambled PCS lane data, the original received lane alignment marker, after error control block insertion and before transcoding. Figure E.2 shows the byte location of the OTN BIP-8 in the transcoded lane marker.
+
+The transcoded lane marker is transmitted together with the transcoded data blocks over the OTN section as defined in Annex B. At the OTN egress after trans-decoding and before scrambling, the ingress alignment marker is recreated using  $M_0$ ,  $M_1$ ,  $M_2$  and ingress  $BIP_3$  of the transcoded alignment marker followed by the bit-wise inversion of these bytes. This recreated alignment marker together with the trans-decoded and unscrambled data blocks is used to calculate the expected OTN BIP-8 for each PCS lane (refer to clause 82.2.8 of [IEEE 802.3]). The expected value will be XORed with the received OTN BIP-8. This error mask will have a "1" for each bit of the OTN BIP-8 which is wrong, and a "0" for each bit which is correct.
+
+The egress  $BIP_3$  for each PCS lane is calculated over the trans-decoded and scrambled data blocks including the trans-decoded alignment marker (refer to clause E.4) following the process depicted in clause 82.2.8 of [IEEE 802.3].
+
+The egress BIP<sub>3</sub> is then adjusted for the errors that occurred up to the OTN egress by first XORing with the PCS BIP-8 error mask and then XORing with the OTN BIP-8 error mask. This combined error mask will be used to compute the number of BIP errors when used for non-intrusive monitoring.
+
+The BIP<sub>7</sub> is created by bit-wise inversion of the adjusted BIP<sub>3</sub>.
+
+#### **E.4.2 Errors detected by 40GBASE-R to OPU3 mapper**
+
+An invalid 66B block will be converted to an error control block before transcoding. An invalid 66B block is one which does not have a sync header of "01" or "10", or one which has a sync header of "10", is not a valid PCS lane alignment marker and has a control block type field which does not appear in Figure B.2 or has one of the values 0x2d, 0x33, 0x66, or 0x55 which are not used for 40GBASE-R. An error control block has sync bits of "10", a block type code of 0x1e, and 8 seven-bit/E/error control characters. This will prevent the Ethernet receiver from interpreting a sequence of bits containing this error as a valid packet.
+
+#### **E.4.3 Errors detected by 40GBASE-R to OPU3 de-mapper**
+
+Several mechanisms will be employed to reduce the probability that the 40GBASE-R to OPU3 de-mapper constructs erroneous parallel 64B/66B encoded data at the egress if bit errors have corrupted. Since detectable corruption normally means that the proper order of 66B blocks to construct at the de-mapper cannot be reliably determined, if any of these checks fail, the de-mapper will transmit eight 66B error control blocks (sync="10", control block type=0x1e, and eight 7-bit/E/control characters).
+
+Mechanisms for improving the robustness and for 513B block lock including PCS lane alignment markers are discussed in Annex F.
+
+## Annex F
+
+### Improved robustness for mapping of 40GBASE-R into OPU3 using 1027B code blocks
+
+(This annex forms an integral part of this Recommendation.)
+
+#### F.1 Introduction
+
+When a parallel 40GBASE-R signal is transcoded as per Annexes B and E and directly mapped into OPU3 without GFP framing, another method is needed to locate the start of 513B blocks and to provide protection to prevent bit errors creating an unacceptable increase in mean time to false packet acceptance (MTTFPA).
+
+#### F.2 513B code block framing and flag bit protection
+
+The mapping of 513B code blocks into OPU3 requires a mechanism for locating the start of the code blocks. A mechanism is also needed to protect the flag bit, whose corruption could cause data to be erroneously interpreted as control and vice versa.
+
+Both of these requirements can be addressed by providing parity across the flag bits of two 513B blocks produced from the transcoding of Annex B.
+
+Figure F.1 illustrates the flag parity bit across two 513B blocks. This creates a minimum two-bit Hamming distance between valid combinations of flag bits.
+
+![Diagram illustrating the flag parity bit across two 513B blocks. The top part shows two 513B blocks, each with a flag bit 'F' and a 512-bit payload. The bottom part shows the resulting 1027B code block structure, which includes a parity bit 'P', two flag bits 'F', and two 512-bit payloads. The flag bits are scrambled. The diagram shows five rows of flag bits (P, F, F) and their corresponding payloads (Data, Control). The rows are: 1 0 0 (Data, Data), 0 0 1 (Data, Control), 0 1 0 (Control, Data), and 1 1 1 (Control, Control). The scrambling process is indicated by a bracket labeled 'Scramble'.](bae3da32cd7a91976285d7e4a3d3018a_img.jpg)
+
+The diagram illustrates the flag parity bit across two 513B blocks. At the top, two 513B blocks are shown, each consisting of a flag bit 'F' and a 512-bit payload. The bottom part shows the resulting 1027B code block structure, which includes a parity bit 'P', two flag bits 'F', and two 512-bit payloads. The flag bits are scrambled. The diagram shows five rows of flag bits (P, F, F) and their corresponding payloads (Data, Control). The rows are: 1 0 0 (Data, Data), 0 0 1 (Data, Control), 0 1 0 (Control, Data), and 1 1 1 (Control, Control). The scrambling process is indicated by a bracket labeled 'Scramble'.
+
+512 bit payload (8 × 66b block)  
+1,024 bit payload (2 × 8 × 66b block)
+
+Flag parity bit
+
+Scramble
+
+G.709-Y.1331(12)\_FF.1
+
+Diagram illustrating the flag parity bit across two 513B blocks. The top part shows two 513B blocks, each with a flag bit 'F' and a 512-bit payload. The bottom part shows the resulting 1027B code block structure, which includes a parity bit 'P', two flag bits 'F', and two 512-bit payloads. The flag bits are scrambled. The diagram shows five rows of flag bits (P, F, F) and their corresponding payloads (Data, Control). The rows are: 1 0 0 (Data, Data), 0 0 1 (Data, Control), 0 1 0 (Control, Data), and 1 1 1 (Control, Control). The scrambling process is indicated by a bracket labeled 'Scramble'.
+
+Figure F.1 – Flag parity bit on two 513B blocks (1027B code)
+
+The flag parity bit creates a sequence that can be used for framing to locate the 513B blocks in a stream of bits. The state diagram of Figure 49-12 of [IEEE 802.3] is applied to locate a 3-bit pattern appearing once per 1027 bits (rather than a 2-bit pattern appearing once per 66 bits) where four out of eight 3-bit sequences (rather than two out of four two-bit values as used in IEEE 802.3) match the pattern. The additional step required is to scramble the non-flag bits so that the legal sequences of these bits are not systematically mimicked in the data itself. The scrambler to be used for this purpose is the Ethernet self-synchronous scrambler using the polynomial  $G(x) = 1 + x^{39} + x^{58}$ .
+
+At the de-mapper, invalid flag bit parity will cause both of the 513B blocks across which the flag bit parity applies to be decoded as 8 × 2 66B error control blocks ("10" sync header, control block type 0x1e, followed by eight 7-bit/E/control characters).
+
+### F.3 66B block sequence check
+
+Bit error corruption of the position or flag continuation bits could cause 66B blocks to be de-mapped from 513B code blocks in the incorrect order. Additional checks are performed to prevent that this results in incorrect packet delineation. Since detectable corruption normally means that the proper order of 66B blocks to construct at the decoder cannot be reliably determined, if any of these checks fail, the decoder will transmit eight 66B error control blocks (sync="10", control block type=0x1e, and eight 7-bit/E/control characters).
+
+Other checks are performed to reduce the probability that invalid data is delivered at the egress in the event that bit errors have corrupted any of the POS fields or flag continuation bits "FC".
+
+If flag bit "F" is 1 (i.e., the 513B block includes at least one 64B/66B control block), for the rows of the table up until the first one with a flag continuation bit of zero (the last one in the block), it is verified that no two 66B control blocks or lane alignment markers within that 513B block have the same value in the POS field, and further, that the POS field values for multiple control or lane alignment rows are in ascending order, which will always be the case for a properly constructed 513B block. If this check fails, the 513B block is decoded into eight 66B error control blocks.
+
+The next check is to ensure that the block sequence corresponds to well-formed packets, which can be done according to the state diagram in Figures F.2 and F.3. This check will determine if 66B blocks are in an order that does not correspond to well-formed packets, e.g., if during an IPG an all-data 66B block is detected without first seeing a control block representing packet start, or if during a packet a control/idle block is detected without first seeing a control block representing packet termination, control blocks have likely been misordered by corruption of either the POS bits or a flag continuation bit. Failure of this check will cause the 513B block to be decoded as eight 66B error control blocks. Note that PCS lane alignment markers are accepted in either state and do not change state as shown in Figure F.3.
+
+The sequence of PCS lane alignment markers is also checked at the decoder. For an interface with  $p$  PCS lanes, the PCS lane alignment markers for lanes 0 to  $p-1$  will appear in a sequence, followed by  $16383 \times p$  non-lane-marker 66B blocks, followed by another group of PCS lane alignment markers. A counter is maintained at the decoder to keep track of when the next group of lane alignment markers is expected. If, in the process of decoding lane alignment markers from a 513B block, a lane alignment marker is found in a position where it is not expected, or a lane alignment marker is missing in a position where it would have been expected, the entire 513B block is decoded as eight 66B error control blocks as shown in Figures F.2, F.3, and F.4.
+
+#### F.3.1 State diagram conventions
+
+The body of this clause is comprised of state diagrams, including the associated definitions of variables, constants, and functions. Should there be a discrepancy between a state diagram and descriptive text, the state diagram prevails.
+
+The notation used in the state diagrams follows the conventions of clause 21.5 of [IEEE 802.3]. State diagram timers follow the conventions of clause 14.2.3.2 of [IEEE 802.3]. The notation ++ after a counter or integer variable indicates that its value is to be incremented.
+
+#### F.3.2 State variables
+
+##### F.3.2.1 Constants
+
+EBLOCK\_T<65:0>
+
+66-bit vector to be sent to the PCS containing /E/ in all the eight character locations.
+
+Mi<65:0>
+
+66-bit vector containing the trans-decoded alignment marker of i-th PCS lane ( $0 < i \leq p$ ). ( $p=4$  for 40GBASE-R).
+
+### F.3.2.2 Variables
+
+1027B\_block\_lock
+
+Indicates the state of the block\_lock variable when the state diagram of Figure 49-12 of [IEEE 802.3] is applied to locate a 3-bit pattern appearing once per 1027 bits (rather than a 2-bit pattern appearing once per 66 bits) as described in clause F.2. Set true when sixty-four contiguous 1027-bit blocks are received with valid 3-bit patterns, set false when sixteen 1027-bit blocks with invalid 3-bit patterns are received before sixty-four valid blocks.
+
+1027B\_high\_ber
+
+Indicates a Boolean variable when the state diagram of Figure 49-13 of [IEEE 802.3] is applied to count invalid 3-bit sync headers of 1027-bit blocks (rather than 2-bit sync headers of 66-bit blocks) within the current 250  $\mu$ s (rather than 125  $\mu$ s). Set true when the ber\_cnt exceeds 8 (rather than 16) indicating a bit error ratio  $>10^{-4}$ .
+
+Mseq\_violation
+
+Indicates a Boolean variable that is set and latched in each rx513\_raw<527:0> PCS lane alignment marker cycle based on the PCS lane marker position and order. It is true if the unexpected marker sequence is detected and false if not.
+
+POS\_violation
+
+A Boolean variable that is set in each rx513\_raw<527:0> based on the POS field values for rx\_tcd<65:0>. It is true if the two or more have the same POS values or if they are not in ascending order, and false if their POS values are in ascending order.
+
+reset
+
+A Boolean variable that controls the resetting of the PCS. It is true whenever a reset is necessary including when reset is initiated from the MDIO, during power on, and when the MDIO has put the PCS into low-power mode.
+
+Rx513\_coded<512:0>
+
+A vector containing the input to the 512B/513B decoder.
+
+rx513\_raw<527:0>
+
+A vector containing eight successive 66-bit vectors (tx\_coded).
+
+rx\_tcd<65:0>
+
+A 66-bit vector transcode-decoded from a 513-bit block following the rules shown in Figure B.5.
+
+seq\_violation
+
+A Boolean variable that is set in each rx513\_raw<527:0> based on the sequence check on an rx\_tcd<65:0> stream. It is true if the unexpected sequence is detected and false if not.
+
+### F.3.2.3 Functions
+
+DECODE(rx513\_coded<512:0>)
+
+Decodes the 513-bit vector returning rx513\_raw<527 :0> which is sent to the client interface. The DECODE function shall decode the block as specified in Figure F.2.
+
+$R\_BLOCK\_TYPE = \{C, S, T, D, E, M\}$
+
+This function classifies each 66-bit  $rx\_tcd$  vector as belonging to one of the six types depending on its contents.
+
+Values: C, S, T, and D are defined in clause 49.2.13.2.3 of [IEEE 802.3].
+
+M: the vector contains a sync header of 10 and is recognized as a valid PCS lane alignment marker by using the state machine shown in Figure F.3.
+
+E: the vector does not meet the criteria for any other value.
+
+$R\_TYPE(rx\_tcd<65:0>)$
+
+Returns the  $R\_BLOCK\_TYPE$  of the  $rx\_tcd<65:0>$  bit vector.
+
+$R\_TYPE\_NEXT$
+
+Prescient end of packet check function. It returns the  $R\_BLOCK\_TYPE$  of the  $rx\_tcd$  vector immediately following the current  $rx\_tcd$  vector.
+
+### F.3.2.4 Counters
+
+$cnt$
+
+Count up to a maximum of  $p$  of the number of PCS lanes.
+
+### F.3.3 State diagrams
+
+The receive state machine for a series of 513-bit blocks shown in Figure F.2 determines whether the 513-bit block contains valid eight 66-bit blocks or not.
+
+![State diagram for the receive state machine for 512B/513B code blocks. It starts with an initialization state RX513B_INIT, transitions to RX513B_VALID if no violations occur, and transitions to RX513B_INVALID if any violations occur. From RX513B_INVALID, it can return to RX513B_INIT if violations persist or to RX513B_VALID if they clear.](2e247f7862345a6a4b40283ed03dc643_img.jpg)
+
+```
+
+stateDiagram-v2
+    [*] --> RX513B_INIT : reset + 1027B_hi_ber + !1027B_block_lock
+    RX513B_INIT --> RX513B_VALID : !POS_violation * !seq_violation * !Mseq_violation
+    RX513B_INIT --> RX513B_INVALID : POS_violation + seq_violation + Mseq_violation
+    RX513B_VALID --> RX513B_INVALID : POS_violation + seq_violation + Mseq_violation
+    RX513B_VALID --> [*] : !POS_violation * !seq_violation * !Mseq_violation
+    RX513B_INVALID --> RX513B_INIT : POS_violation + seq_violation + Mseq_violation
+    RX513B_INVALID --> RX513B_VALID : !POS_violation * !seq_violation * !Mseq_violation
+  
+```
+
+The state machine consists of three states: **RX513B\_INIT**, **RX513B\_VALID**, and **RX513B\_INVALID**.
+
+- RX513B\_INIT**: Initial state. Action:  $rx513\_raw \leftarrow 8 \times EBLOCK\_T$ . Entry condition:  $reset + 1027B\_hi\_ber + !1027B\_block\_lock$ .
+- RX513B\_VALID**: Valid state. Action:  $rx513\_raw \leftarrow DECODE(rx513\_coded)$ . Entry condition:  $!POS\_violation * !seq\_violation * !Mseq\_violation$ . Exit condition:  $!POS\_violation * !seq\_violation * !Mseq\_violation$ .
+- RX513B\_INVALID**: Invalid state. Action:  $rx513\_raw \leftarrow 8 \times EBLOCK\_T$ ,  $seq\_violation \leftarrow False$ ,  $Mseq\_violation \leftarrow False$ . Entry condition:  $POS\_violation + seq\_violation + Mseq\_violation$ . Exit condition:  $!POS\_violation * !seq\_violation * !Mseq\_violation$ .
+
+Transitions:
+
+- From **RX513B\_INIT** to **RX513B\_VALID**:  $!POS\_violation * !seq\_violation * !Mseq\_violation$ .
+- From **RX513B\_INIT** to **RX513B\_INVALID**:  $POS\_violation + seq\_violation + Mseq\_violation$ .
+- From **RX513B\_VALID** to **RX513B\_INVALID**:  $POS\_violation + seq\_violation + Mseq\_violation$ .
+- From **RX513B\_VALID** to exit:  $!POS\_violation * !seq\_violation * !Mseq\_violation$ .
+- From **RX513B\_INVALID** to **RX513B\_INIT**:  $POS\_violation + seq\_violation + Mseq\_violation$ .
+- From **RX513B\_INVALID** to **RX513B\_VALID**:  $!POS\_violation * !seq\_violation * !Mseq\_violation$ .
+
+State diagram for the receive state machine for 512B/513B code blocks. It starts with an initialization state RX513B\_INIT, transitions to RX513B\_VALID if no violations occur, and transitions to RX513B\_INVALID if any violations occur. From RX513B\_INVALID, it can return to RX513B\_INIT if violations persist or to RX513B\_VALID if they clear.
+
+G.709-Y.1331(20)\_FF.2
+
+**Figure F.2 – Receive state machine for the 512B/513B code blocks including lane alignment markers**
+
+The trans-decode state machine for a series of 66-bit blocks shown in Figure F.3 checks the block type sequence of recovered 66-bit blocks.
+
+The PCS lane alignment marker state machine for a series of 66-bit blocks shown in Figure F.4 detects the alignment markers every  $p \times 16384$  blocks and checks whether the marker is in ascendant order or not.
+
+![State machine diagram for the trans-decode state machine for 64B/66B code blocks. It starts with RX_INIT and transitions through RX_C, RX_D, RX_T, and RX_Seq_Violation states based on R_TYPE(rx_tcd) conditions.](7896390ac3d26645db5fc41aedc7d6f4_img.jpg)
+
+```
+
+stateDiagram-v2
+    [*] --> RX_INIT : reset + 1027B_hi_ber + !1027B_block_lock
+    RX_INIT --> RX_C : R_TYPE(rx_tcd) = S
+    RX_INIT --> RX_D : R_TYPE(rx_tcd) = (D+T)
+    RX_INIT --> RX_T : R_TYPE(rx_tcd) = (C+E+M)
+    RX_C --> RX_C : R_TYPE(rx_tcd) = (C+E+M)
+    RX_C --> RX_D : R_TYPE(rx_tcd) = S
+    RX_C --> RX_T : R_TYPE(rx_tcd) = (D+T)
+    RX_D --> RX_C : R_TYPE(rx_tcd) = (D+E+M)
+    RX_D --> RX_D : R_TYPE(rx_tcd) = (D+E+M)
+    RX_D --> RX_T : R_TYPE(rx_tcd) = T*
+    RX_D --> RX_Seq_Violation : (R_TYPE(rx_tcd) = T* AND R_TYPE_NEXT = (E+D+T)) + R_TYPE(rx_tcd) = (C+S)
+    RX_T --> RX_C : R_TYPE(rx_tcd) = (C+M)
+    RX_T --> RX_D : R_TYPE(rx_tcd) = S
+    RX_T --> RX_Seq_Violation : R_TYPE(rx_tcd) = T* AND R_TYPE_NEXT = (S+C+M)
+    RX_Seq_Violation --> RX_C : R_TYPE(rx_tcd) = (C+E+M)
+    RX_Seq_Violation --> RX_D : R_TYPE(rx_tcd) = D
+    RX_Seq_Violation --> RX_T : R_TYPE(rx_tcd) = T* AND R_TYPE_NEXT = (E+D+T)) + R_TYPE(rx_tcd) = (C+S)
+  
+```
+
+The diagram shows a state machine with five states: RX\_INIT, RX\_C, RX\_D, RX\_T, and RX\_Seq\_Violation. RX\_INIT is the initial state, entered via a reset condition. It contains an initialization `seq_violation ← False`. Transitions from RX\_INIT are based on `R_TYPE(rx_tcd)`: `S` leads to RX\_C, `(D+T)` leads to RX\_D, and `(C+E+M)` leads to RX\_T. RX\_C has a self-loop for `(C+E+M)`, transitions to RX\_D for `S`, and to RX\_T for `(D+T)`. RX\_D has a self-loop for `(D+E+M)`, transitions to RX\_C for `(D+E+M)`, to RX\_T for `T*`, and to RX\_Seq\_Violation for a specific violation condition. RX\_T transitions to RX\_C for `(C+M)`, to RX\_D for `S`, and to RX\_Seq\_Violation for another violation condition. RX\_Seq\_Violation contains `seq_violation ← True` and has transitions back to RX\_C, RX\_D, and RX\_T based on specific conditions.
+
+State machine diagram for the trans-decode state machine for 64B/66B code blocks. It starts with RX\_INIT and transitions through RX\_C, RX\_D, RX\_T, and RX\_Seq\_Violation states based on R\_TYPE(rx\_tcd) conditions.
+
+G.709-Y.1331(20)\_FF.3
+
+**Figure F.3 – Trans-decode state machine for the 64B/66B code blocks including the lane alignment markers**
+
+![State machine diagram for lane alignment markers with states RX_INIT, RX_CNT_INIT, RX_CNT, RX_M, and RX_ME. Transitions are labeled with UCT, CT, and M. Conditions include reset + 1027B_hi_ber + !1027B_block_lock, Mseq_violation, cnt, and rx_tcd.](1b2e5b12ac4f5d7bb2fa18524982f2d8_img.jpg)
+
+```
+
+stateDiagram-v2
+    [*] --> RX_INIT : reset + 1027B_hi_ber + !1027B_block_lock
+    RX_INIT --> RX_CNT_INIT : UCT
+    RX_INIT --> RX_CNT_INIT : CT
+    RX_CNT_INIT --> RX_CNT : UCT
+    RX_CNT --> RX_INIT : cnt < 0
+    RX_CNT --> RX_M : cnt = 0 * rx_tcd = M1
+    RX_CNT --> RX_M : cnt = 0 * rx_tcd! = M1
+    RX_M --> RX_INIT : cnt < p * rx_tcd = Mcnt+1
+    RX_M --> RX_ME : cnt = p
+    RX_M --> RX_M : cnt < p * rx_tcd! = Mcnt+1
+    RX_ME --> RX_M : cnt < p * rx_tcd = Mcnt+1
+    RX_ME --> [*] : cnt = p
+    RX_ME --> RX_M : cnt < p * rx_tcd! = Mcnt+1
+  
+```
+
+**States:**  
+ RX\_INIT: Mseq\_violation ← False  
+ RX\_CNT\_INIT: cnt ← -(p × 16383)+1  
+ RX\_CNT: cnt ++  
+ RX\_M: cnt ++  
+ RX\_ME: Mseq\_violation ← True, cnt ++
+
+**Transitions:**  
+ RX\_INIT → RX\_CNT\_INIT (UCT, CT)  
+ RX\_CNT\_INIT → RX\_CNT (UCT)  
+ RX\_CNT → RX\_INIT (cnt < 0)  
+ RX\_CNT → RX\_M (cnt = 0 \* rx\_tcd = M1, cnt = 0 \* rx\_tcd! = M1)  
+ RX\_M → RX\_INIT (cnt < p \* rx\_tcd = Mcnt+1)  
+ RX\_M → RX\_ME (cnt = p)  
+ RX\_M → RX\_M (cnt < p \* rx\_tcd! = Mcnt+1)  
+ RX\_ME → RX\_M (cnt < p \* rx\_tcd = Mcnt+1)  
+ RX\_ME → [\*] (cnt = p)  
+ RX\_ME → RX\_M (cnt < p \* rx\_tcd! = Mcnt+1)
+
+p = 4 for 40GbE
+
+G.709-Y.1331(16)-Cor.2(19)\_FF.4
+
+State machine diagram for lane alignment markers with states RX\_INIT, RX\_CNT\_INIT, RX\_CNT, RX\_M, and RX\_ME. Transitions are labeled with UCT, CT, and M. Conditions include reset + 1027B\_hi\_ber + !1027B\_block\_lock, Mseq\_violation, cnt, and rx\_tcd.
+
+Figure F.4 – Receive state machine for the lane alignment markers
+
+## Annex G
+
+### Mapping ODU0 into a low latency OTU0 (OTU0LL)
+
+(This annex forms an integral part of this Recommendation.)
+
+#### G.1 Introduction
+
+Within the optical transport network client signals with a bit rate up to 1.25 Gbit/s are transported within an ODU0 and the ODU0 is transported within a server ODUk and OTUk (k = 1,2,3,4). This annex specifies a low latency 1.25G OTU0 (OTU0LL) frame format in which one ODU0 is transported which carries a client (e.g., 1G Ethernet) signal using an [ITU-T G.698.3] application code. This OTU0LL may be used at the edge of the optical transport network.
+
+#### G.2 Optical transport unit 0 low latency (OTU0LL)
+
+The OTU0LL conditions the ODU0 for transport over a multi-vendor optical network interface at the edge of the optical transport network. The OTU0LL frame structure, including the OTU0LL FEC is completely standardized. The optical aspects of the multi-vendor optical network interface at the edge of the optical transport network are outside the scope of this Recommendation.
+
+NOTE 1 – Transport of the OTU0LL over the interfaces specified in this Recommendation is not supported.
+
+NOTE 2 – An ODU0 which is transported within an OTU0LL may be passed through the OTN and terminated at the far end edge of the OTN.
+
+##### G.2.1 OTUk frame structure
+
+The OTU0LL frame structure is based on the ODU0 frame structure and extends it with a distributed forward error correction (FEC) as shown in Figure G.1. Sixteen times 16 columns are added to the ODU0 frame for the FEC and the reserved overhead bytes in row 1, columns 8 to 14 of the ODU0 overhead are used for an OTU0LL specific overhead, resulting in an octet-based block frame structure with four rows and 4080 columns. The MSB in each octet is bit 1, the LSB is bit 8.
+
+The OTU0LL overhead is the same as the OTUk overhead.
+
+The bit rate of the OTU0LL signal is  $255/239 \times 1\,244\,160$  kbit/s ( $\sim 1\,327\,451.046$  kbit/s). The frame period of the OTU0LL signal is approximately 98.354  $\mu$ s.
+
+The sixty-four 16-byte RS(255,239) FEC fields in the OTU0LL frame contain the Reed-Solomon RS(255,239) FEC code. Each RS(255,239) FEC is computed over the previous 239 OTU0LL bytes. Transmission of the OTU0LL FEC is mandatory.
+
+NOTE – The distribution of the RS(255,239) FEC fields over the OTU0LL frame minimizes the transfer delay introduced by the processing of this FEC and the number of codecs to compute this FEC.
+
+The RS(255,239) FEC code shall be computed as specified in Annex A with the notion that each FEC is computed over the previous 239 OTU0LL bytes instead of over a sub-row as described in this annex for the case of an OTUk (k=1,2,3,4).
+
+![Figure G.1: OTU0LL frame structure, overhead and ODU0 mapping. The diagram shows a frame with 4080 columns and 4 rows. The first 239 columns are overhead (FA OH and OTU0LL OH). Columns 240 to 4064 contain 14 blocks of 4 x (239 + 16) bytes, which are mapped to ODU0. Columns 4065 to 4080 are RS(255,239) FEC. A callout shows the overhead structure: Row 1: FA OH (columns 1-14), OTU0LL OH (columns 15-239). Row 2: (4 x 239 bytes). Row 3: (4 x 239 bytes). Row 4: (4 x 239 bytes). A table at the bottom shows the overhead structure: Row 1: FAS (columns 1-6), MFAS (columns 7-8), SM (columns 9-10), GCC0 (columns 11-12), RES (columns 13-14).](524ed6dbe4bf1dd88e75c40fa79f3d4a_img.jpg)
+
+Figure G.1: OTU0LL frame structure, overhead and ODU0 mapping. The diagram shows a frame with 4080 columns and 4 rows. The first 239 columns are overhead (FA OH and OTU0LL OH). Columns 240 to 4064 contain 14 blocks of 4 x (239 + 16) bytes, which are mapped to ODU0. Columns 4065 to 4080 are RS(255,239) FEC. A callout shows the overhead structure: Row 1: FA OH (columns 1-14), OTU0LL OH (columns 15-239). Row 2: (4 x 239 bytes). Row 3: (4 x 239 bytes). Row 4: (4 x 239 bytes). A table at the bottom shows the overhead structure: Row 1: FAS (columns 1-6), MFAS (columns 7-8), SM (columns 9-10), GCC0 (columns 11-12), RES (columns 13-14).
+
+**Figure G.1 – OTU0LL frame structure, overhead and ODU0 mapping**
+
+The transmission order of the bits in the OTU0LL frame is left to right, top to bottom, and MSB to LSB (see Figure G.2).
+
+![Figure G.2: Transmission order of the OTU0LL frame bits. The diagram shows a frame with 4080 columns and 4 rows. The transmission order is indicated by arrows pointing from left to right, top to bottom. A callout shows the bit order within a byte: MSB (bit 1) to LSB (bit 8).](b437cd7078b36507e5d918fe6224e6dd_img.jpg)
+
+Figure G.2: Transmission order of the OTU0LL frame bits. The diagram shows a frame with 4080 columns and 4 rows. The transmission order is indicated by arrows pointing from left to right, top to bottom. A callout shows the bit order within a byte: MSB (bit 1) to LSB (bit 8).
+
+**Figure G.2 – Transmission order of the OTU0LL frame bits**
+
+## G.2.2 Scrambling
+
+The OTU0LL signal must have sufficient bit timing content at the NNI. A suitable bit pattern, which prevents a long sequence of "1"s or "0"s, is provided by using a scrambler.
+
+The operation of the scrambler shall be functionally identical to that of a frame synchronous scrambler of sequence length 65535 operating at the OTU0LL rate.
+
+The generating polynomial shall be  $1 + x + x^3 + x^{12} + x^{16}$ . Figure G.3 shows a functional diagram of the frame synchronous scrambler.
+
+![Block diagram of a frame synchronous scrambler. It shows a 16-bit shift register with 16 stages, each containing a D flip-flop (D) and a switch (S). The stages are connected in series. The output of the 16th stage is summed with the input data at a summation node (⊕) to produce the 'Scrambled data out'. Feedback paths from the 1st, 2nd, and 16th stages are summed at three separate nodes (⊕) and fed back into the 1st, 2nd, and 16th stages respectively. The shift register is clocked by 'OTU0LL clock'. The initial state is set by 'OTU0LL MSB of MFAS byte'. A reference label 'G.709-Y.1331(12)-Amd.2(13)_FG.3' is present in the bottom right.](7188dd653353235466aea783783e26c8_img.jpg)
+
+Block diagram of a frame synchronous scrambler. It shows a 16-bit shift register with 16 stages, each containing a D flip-flop (D) and a switch (S). The stages are connected in series. The output of the 16th stage is summed with the input data at a summation node (⊕) to produce the 'Scrambled data out'. Feedback paths from the 1st, 2nd, and 16th stages are summed at three separate nodes (⊕) and fed back into the 1st, 2nd, and 16th stages respectively. The shift register is clocked by 'OTU0LL clock'. The initial state is set by 'OTU0LL MSB of MFAS byte'. A reference label 'G.709-Y.1331(12)-Amd.2(13)\_FG.3' is present in the bottom right.
+
+**Figure G.3 – Frame synchronous scrambler**
+
+The scrambler shall be reset to "FFFF" (HEX) on the most significant bit of the byte following the last framing byte in the OTU0LL frame, i.e., the MSB of the MFAS byte. This bit, and all subsequent bits to be scrambled shall be added modulo 2 to the output from the  $x^{16}$  position of the scrambler. The scrambler shall run continuously throughout the complete OTU0LL frame. The framing bytes (FAS) of the OTU0LL overhead shall not be scrambled.
+
+Scrambling is performed after FEC computation and insertion into the OTU0LL signal.
+
+## Annex H
+
+### OTUCn sub rates (OTUCn-M)
+
+(This annex forms an integral part of this Recommendation.)
+
+#### H.1 Introduction
+
+This annex defines a substrate OTUCn, note that substrates are not defined for the OPUCn and ODUCn. Additional descriptive text, examples and applications are provided in Appendix XIII.
+
+The OPUCn, ODUCn and OTUCn are defined in terms of  $n \times 100$  Gbit/s signals. For the OTN optical networking interface it may be advantageous to carry an OTUCn with a bit rate that is not constrained to be an integer multiple of 100 Gbit/s. This OTU is described as an OTUCn-M.
+
+#### H.2 OTUCn-M frame format
+
+The OTUCn-M frame is a type of OTUCn frame which contains  $n$  instances of OTUC, ODUC and OPUC overhead and  $M$  5 Gbit/s OPUCn tributary slots. If a particular value of  $M$  is not indicated, the frame contains  $20 \times n$  tributary slots. See Appendix XIII for examples.
+
+An OTUCn-M framed signal can be carried over OTN optical networking interfaces. Values of  $M$  supported and the subset of the  $20n$  5 Gbit/s OPUCn tributary slots that are included in the OTUCn-M on such an OTN optical networking interface are vendor specific and outside the scope of this Recommendation.
+
+The OPU tributary slots that are included in the OTUCn-M structure will have their availability bit in the OPUCn MSI overhead set to "available" (see 20.4.1.1). The OPU tributary slots which might not be carried transparently by the OTUCn-M structure will have their availability bit in the OPUCn MSI overhead set to "unavailable" (see 20.4.1.1). The data in tributary slots marked as unavailable must be set to "all 0".
+
+## **Annex I**
+
+*This annex is intentionally left blank.*
+
+## Annex J
+
+### Recovery of 64B/66B encoded clients from parallel 256B/257B interfaces
+
+(This annex forms an integral part of this Recommendation.)
+
+Figure J.1 illustrates the processing performed on the 200 and 400 GbE signal between the physical Ethernet interface and the point where the Ethernet signal is connected with the ODUflex to 200/400GbE adaptation function. In the receive direction (Figure J.1, right) the 200 or 400 GbE signal presented at the PMA interface passes through the AM lock and deskew, lane reorder and de-interleave, FEC decoder, post-FEC interleave, AM removal,  $x^{58}$  descrambler and 256b/257b to 64B/66B transcode processes that are specified in clause 119 of [IEEE 802.3]. The 64B/66B encoded signal is then adapted into the ODUflex and mapped into the OPUCn.
+
+![Figure J.1: Processing of 200/400GbE signal. A block diagram showing two signal paths: Transmit (left) and Receive (right). The Transmit path flows from Transport network -> ODUCn/OTUCn -> OPUCn Demap -> Adapt from ODUflex -> PCS (Symbol distribution and interleave -> FEC encoder -> Pre-FEC distribution -> AM insertion -> x^58 scrambler -> Transcode) -> CDMII. The Receive path flows from CDMII -> 64B/66B decode and rate matching -> Transcode -> x^58 descrambler -> AM removal -> Post-FEC interleave -> FEC decoder -> Lane reorder and de-interleave -> AM lock and deskew -> PMA interface. The right side also shows a path from Adapt into ODUflex -> OPUCn Map -> ODUCn/OTUCn -> Transport network.](537370c7a708dfe4aa0c89e075f215e4_img.jpg)
+
+```
+
+    graph TD
+    subgraph "Transport network (Left)"
+    TN1[Transport network] --> ODUCn1[ODUCn/OTUCn]
+    ODUCn1 --> OPUCnD[OPUCn Demap]
+    OPUCnD --> AdaptF[Adapt from ODUflex]
+    end
+
+    subgraph "PCS (Transmit)"
+    AdaptF --> Transcode1[Transcode]
+    Transcode1 --> Scrambler[x^58 scrambler]
+    Scrambler --> AMIns[AM insertion]
+    AMIns --> PreFEC[Pre-FEC distribution]
+    PreFEC --> FECEnc[FEC encoder]
+    FECEnc --> SymDist[Symbol distribution and interleave]
+    end
+
+    SymDist --> PMA1[PMA interface]
+
+    subgraph "PCS (Receive)"
+    PMA2[PMA interface] --> AMLock[AM lock and deskew]
+    AMLock --> LaneRe[Lane reorder and de-interleave]
+    LaneRe --> FECDec[FEC decoder]
+    FECDec --> PostFEC[Post-FEC interleave]
+    PostFEC --> AMRem[AM removal]
+    AMRem --> Descrambler[x^58 descrambler]
+    Descrambler --> Transcode2[Transcode]
+    end
+
+    Transcode2 --> AdaptI[Adapt into ODUflex]
+
+    subgraph "Transport network (Right)"
+    AdaptI --> OPUCnM[OPUCn Map]
+    OPUCnM --> ODUCn2[ODUCn/OTUCn]
+    ODUCn2 --> TN2[Transport network]
+    end
+
+    CDMII1[CDMII] -.-> Transcode1
+    CDMII2[CDMII] -.-> Decode[64B/66B decode and rate matching]
+    Decode -.-> Transcode2
+  
+```
+
+G.709-Y.1331(16)-Amd.2(18)\_FJ.1
+
+Figure J.1: Processing of 200/400GbE signal. A block diagram showing two signal paths: Transmit (left) and Receive (right). The Transmit path flows from Transport network -> ODUCn/OTUCn -> OPUCn Demap -> Adapt from ODUflex -> PCS (Symbol distribution and interleave -> FEC encoder -> Pre-FEC distribution -> AM insertion -> x^58 scrambler -> Transcode) -> CDMII. The Receive path flows from CDMII -> 64B/66B decode and rate matching -> Transcode -> x^58 descrambler -> AM removal -> Post-FEC interleave -> FEC decoder -> Lane reorder and de-interleave -> AM lock and deskew -> PMA interface. The right side also shows a path from Adapt into ODUflex -> OPUCn Map -> ODUCn/OTUCn -> Transport network.
+
+**Figure J.1 – Processing of 200/400GbE signal**
+
+Figure J.2 illustrates the processing performed on the 50 GbE signal between the physical Ethernet interface and the point where the Ethernet signal is connected with the ODUflex to 50GbE adaptation function. In the receive direction (Figure J.2, right) the 50 GbE signal presented at the FEC or PMA interface passes through the Lane block sync, AM lock and deskew, lane reorder processes that are specified in clause 133 of [IEEE 802.3cd]. The 64B/66B encoded signal is then adapted into the ODUflex and mapped into the OPUk or OPUCn.
+
+![Block diagram showing the processing of a 50GbE signal between a Transport network and a FEC or PMA interface. The diagram is split into two halves by a central PCS block. The left half shows the transmit path: Transport network -> ODUk/OTUk ODUCn/OTUCn -> OPUk or OPUCn Demap -> Adapt from ODUflex -> Alignment insertion -> Block distribution -> X^58 scrambler -> 64B/66B encode and rate matching -> 50GMII. The right half shows the receive path: 50GMII -> 64B/66B decode and rate matching -> X^58 descrambler -> Alignment removal -> Lane reorder -> Alignment lock Lane deskew -> Lane block sync -> FEC or PMA interface. A BER monitor is connected to the PCS block. The right side also includes a return path: Adapt into ODUflex -> OPUk or OPUCn Map -> ODUk/OTUk ODUCn/OTUCn -> Transport network.](1b54a9e1b22fff830f6767035580c39e_img.jpg)
+
+The diagram illustrates the signal processing flow for a 50GbE signal. On the left, data from a Transport network passes through ODUk/OTUk ODUCn/OTUCn, OPUk or OPUCn Demap, and Adapt from ODUflex blocks. It then enters the PCS block via Alignment insertion, Block distribution, X<sup>58</sup> scrambler, and 64B/66B encode and rate matching, reaching the 50GMII interface. On the right, the signal from the 50GMII interface is processed through 64B/66B decode and rate matching, X<sup>58</sup> descrambler, Alignment removal, Lane reorder, Alignment lock Lane deskew, and Lane block sync, finally reaching the FEC or PMA interface. A BER monitor is connected to the PCS block. A return path on the right shows data being Adapt into ODUflex, OPUk or OPUCn Map, and ODUk/OTUk ODUCn/OTUCn before returning to the Transport network.
+
+Block diagram showing the processing of a 50GbE signal between a Transport network and a FEC or PMA interface. The diagram is split into two halves by a central PCS block. The left half shows the transmit path: Transport network -> ODUk/OTUk ODUCn/OTUCn -> OPUk or OPUCn Demap -> Adapt from ODUflex -> Alignment insertion -> Block distribution -> X^58 scrambler -> 64B/66B encode and rate matching -> 50GMII. The right half shows the receive path: 50GMII -> 64B/66B decode and rate matching -> X^58 descrambler -> Alignment removal -> Lane reorder -> Alignment lock Lane deskew -> Lane block sync -> FEC or PMA interface. A BER monitor is connected to the PCS block. The right side also includes a return path: Adapt into ODUflex -> OPUk or OPUCn Map -> ODUk/OTUk ODUCn/OTUCn -> Transport network.
+
+G.709-Y.1331(16)-Amd.3(19)\_FJ.2
+
+**Figure J.2 – Processing of 50GbE signal**
+
+## Annex K
+
+### Transporting 200GbE and 400GbE am\_sf<2:0> information through a single optical link between two Ethernet/OTN transponder entities in the OTN
+
+(This annex forms an integral part of this Recommendation.)
+
+#### K.1 Introduction
+
+IP routers may support a "soft reroute" feature, which will direct IP traffic away from an optical link that experiences an increased number of FEC errors on that optical link. 200 and 400 Gbit/s Ethernet interfaces that are compliant with [IEEE 802.3] will be able to support this feature. Router vendors would like to see this feature also supported for cases in which two routers are interconnected via an OTN network. The Ethernet interfaces between router and OTN network could be equipped with (Router B in Figure K.1) or without (Router A) a clause 118 extender sublayer. In general such support is not feasible, because a 200G or 400 Gbit/s Ethernet service can be transported over more than one optical link in the OTN passing through intermediate 3R regeneration functions and ODU cross connects. Nonetheless, support for this feature is possible for the case that such service is carried over a single optical link (supported by one OTSiA trail) in the OTN, with Ethernet to OTN transponders at the two end points as illustrated in Figure K.1. For such case the Ethernet to OTN mapper and demapper processes and the OTN FEC processes are within the same transponder and the FEC status information can be exchanged between these processes.
+
+[IEEE 802.3] has specified three bits in the AM field (am\_sf<2:0>) to carry link status information to support this feature. Bit am\_sf<2> is defined as a Remote Degrade (RD) signal, bit am\_sf<1> is defined as a Local Degrade (LD) signal and bit am\_sf<0> is reserved.
+
+![Figure K.1: Local/Remote degrade interworking between router and OTN transponders. The diagram shows the flow of status information (Reserved, RD, LD) between Router A, OTN transponder X, OTN transponder Y, and Router B. Router A has PCS and Ethernet FEC blocks. OTN transponders X and Y have OTN FEC, (De)Mapper, and PCS blocks. Router B has PCS, Ethernet FEC, and DTE/DS blocks. Status bits are shown being passed through the OTN transponders via PSI overhead bytes (PSI[2, 2], PSI[2, 3], PSI[2, 4]).](f3fd3ff8f78da4c2a4d39bb6330c49a1_img.jpg)
+
+The diagram illustrates the interworking of Local/Remote degrade signals between two routers (Router A and Router B) connected via two OTN transponders (X and Y). The signal flow is as follows:
+
+- Router A:** Contains PCS and Ethernet FEC blocks. It generates status bits: Reserved (am\_sf<0>), RD (am\_sf<2>), and LD (am\_sf<1>). These are passed to OTN transponder X.
+- OTN transponder X:** Contains OTN FEC, (De)Mapper, and PCS blocks. It receives status bits from Router A and forwards them to OTN transponder Y via PSI overhead bytes (PSI[2, 2], PSI[2, 3], PSI[2, 4]).
+- OTN transponder Y:** Contains OTN FEC, (De)Mapper, and PCS blocks. It receives status bits from OTN transponder X and forwards them to Router B via PSI overhead bytes (PSI[2, 2], PSI[2, 3], PSI[2, 4]).
+- Router B:** Contains PCS, Ethernet FEC, and DTE/DS blocks. It receives status bits from OTN transponder Y and processes them.
+
+The diagram also shows the data paths for 200GBASE-R and 400GBASE-R Ethernet signals, which are mapped into the OTN transponders and transported over a single optical span and FEC. The status information is carried in the OTN transponder application layer.
+
+Figure K.1: Local/Remote degrade interworking between router and OTN transponders. The diagram shows the flow of status information (Reserved, RD, LD) between Router A, OTN transponder X, OTN transponder Y, and Router B. Router A has PCS and Ethernet FEC blocks. OTN transponders X and Y have OTN FEC, (De)Mapper, and PCS blocks. Router B has PCS, Ethernet FEC, and DTE/DS blocks. Status bits are shown being passed through the OTN transponders via PSI overhead bytes (PSI[2, 2], PSI[2, 3], PSI[2, 4]).
+
+G.709-Y.1331(16)-Amd.2(18)\_FK.1
+
+Figure K.1 – Local/Remote degrade interworking between router and OTN transponders
+
+For the special case described above (illustrated in Figure K.1), the OTN transponders X and Y can forward the information in the Reserved (am\_sf<0>) and RD (am\_sf<2>) bits between ingress and egress transponder. The information in am\_sf<0> can be carried in OPUflex PSI overhead byte 2, bit 2. The status information in am\_sf<2> can be carried in OPUflex PSI overhead byte 2, bit 4. The status information in the LD (am\_sf<1>) bit can be carried after some additional processing in
+
+OPUflex PSI overhead byte 2, bit 3 as illustrated in Figure K.1. The additional processing comprises the OR'ing of the LD status in the am\_sf<1> bit of a 200G or 400G Ethernet signal with the local Ethernet FEC degrade status in the ingress transponder (X). In the egress transponder (Y), additional processing comprises the OR'ing of the LD status in the PSI[2,3] overhead bit of the OPUflex signal with the local OTN FEC degrade status in the transponder (details defined by [ITU-T G.798]). The resulting LD status is then carried in the am\_sf<1> bit of the 200 or 400 Gbit/s Ethernet signal.
+
+## **K.2 Client Degrade Indication (CDI) overhead**
+
+A 3-bit Client Defect Indication is defined in bits 2, 3 and 4 of the PSI[2] byte of the payload structure identifier to indicate the client degrade status of a 200 and 400 Gbit/s Ethernet client signal which is transferred via one OTSiA trail.
+
+OPU PSI[2,2] is used to transfer the status information present in the 200 Gbit/s or 400 Gbit/s Ethernet client's am\_sf<0> bit.
+
+OPU PSI[2,3] is used to transfer the Local Degrade status information, which is determined by OR'ing the value present in the 200 or 400 Gbit/s Ethernet client's am\_sf<1> bit with the 200 or 400 Gbit/s Ethernet FEC Degrade status as specified in [IEEE 802.3].
+
+OPU PSI[2,4] is used to transfer the Remote Degrade status information present in the 200 Gbit/s or 400 Gbit/s Ethernet client's am\_sf<2> bit.
+
+## Annex L
+
+### OTU25u and OTU50u interfaces
+
+(This annex forms an integral part of this Recommendation.)
+
+#### L.1 Introduction
+
+In network applications that do not require support of all client signals, the OTU25 and OTU50 interfaces may be operated at a 5.2% lower rate. The bit rates of such "under-clocked" OTU25u and OTU50u are specified in this annex. All other OTU25 and OTU50 interface related specifications apply for the OTU25u and OTU50u.
+
+Figure L.1 shows the relationship between various information structure elements and illustrates the multiplexing structure and mappings for the OTU25u and OTU50u. Figure L.1 shows that an ODUk ( $k = 0, 1, 2, 2e, 3, flex$ ) signal is mapped into an OPU25u and an ODUk ( $k = 0, 1, 2, 2e, 3, flex$ ) signal is mapped into an OPU50u. This OPU25u or OPU50u signal is mapped into the associated ODU25u or ODU50u. This ODU25u or ODU50u signal is mapped into the associated OTU25u or OTU50u signal.
+
+![Figure L.1: OTN multiplexing and mapping structures for OTU25u and OTU50u. The diagram shows two parallel structures. The top structure for OTU50u shows an OTU50u signal being mapped into an ODU50u, which is then mapped into two OPU50u signals. These OPU50u signals are multiplexed into an ODTUG50u (PT = 21) signal. The ODTUG50u signal is then mapped into five ODTU50u signals: ODTU50u.1 (x 40), ODTU50u.2 (x 20), ODTU50u.9 (x 4), ODTU50u.33 (x 1), and ODTU50u.ts (x [40/ts]). These ODTU50u signals are then mapped into client signals: Null, PRBS, Proprietary use, ODU0, ODU1, ODU2, ODU2e, ODU3, and ODUflex. The bottom structure for OTU25u is similar but with different scaling factors: ODTU25u.1 (x 20), ODTU25u.2 (x 10), ODTU25u.9 (x 2), and ODTU25u.ts (x [20/ts]). A legend at the bottom indicates that white boxes represent Multiplexing and grey boxes represent Mapping.](bd200589aacf1ff9a3d4e245938cbcc8_img.jpg)
+
+G.709-Y.1331(20)\_FL.1
+
+Figure L.1: OTN multiplexing and mapping structures for OTU25u and OTU50u. The diagram shows two parallel structures. The top structure for OTU50u shows an OTU50u signal being mapped into an ODU50u, which is then mapped into two OPU50u signals. These OPU50u signals are multiplexed into an ODTUG50u (PT = 21) signal. The ODTUG50u signal is then mapped into five ODTU50u signals: ODTU50u.1 (x 40), ODTU50u.2 (x 20), ODTU50u.9 (x 4), ODTU50u.33 (x 1), and ODTU50u.ts (x [40/ts]). These ODTU50u signals are then mapped into client signals: Null, PRBS, Proprietary use, ODU0, ODU1, ODU2, ODU2e, ODU3, and ODUflex. The bottom structure for OTU25u is similar but with different scaling factors: ODTU25u.1 (x 20), ODTU25u.2 (x 10), ODTU25u.9 (x 2), and ODTU25u.ts (x [20/ts]). A legend at the bottom indicates that white boxes represent Multiplexing and grey boxes represent Mapping.
+
+Figure L.1 – OTN multiplexing and mapping structures for OTU25u and OTU50u
+
+#### L.2 Bit rates
+
+The bit rates and tolerance of the OTU25u and OTU50u signals are defined in Table L.1.
+
+The bit rates and tolerance of the ODU25u and ODU50u signals are defined in Table L.2.
+
+The bit rates and tolerance of the OPU25u and OPU50u payload are defined in Table L.3.
+
+The OTU25u, OTU50u, ODU25u, ODU50u, OPU25u and OPU50u frame periods are defined in Table L.4.
+
+The 1.25G tributary slot related OPU25u and OPU50u multiframe periods are defined in Table L.5.
+
+The ODTU payload area bandwidths are defined in Table L.6.
+
+The number of OPU25u and OPU50u tributary slots required by a client ODU are summarized in Table L.7. Note that the value of  $n$  for ODUflex(GFP, $n,2$ ) is not restricted to the range  $1 \leq n \leq 8$  as specified in Table 7-8.
+
+**Table L.1 – OTU types and bit rates**
+
+| OTU type                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   | OTU nominal bit rate                   | OTU bit-rate tolerance |
+|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------|------------------------|
+| OTU25u                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     | $2937/2912 \times 24\,883\,200$ kbit/s | $\pm 20$ ppm           |
+| OTU50u                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     | $2937/2912 \times 49\,766\,400$ kbit/s |                        |
+| NOTE 1 – The nominal OTU rates are approximately: 25 096 826.374 kbit/s (OTU25u), 50 193 652.747 kbit/s (OTU50u).<br>NOTE 2 – The OTU25u and OTU50u signal bit rates do not include a FEC overhead area.<br>NOTE 3 – The OTU25u bit rate can be based on the OTU25u-RS bit rate as follows: $514/528 \times 41118/41120 \times \text{OTU25u-RS bit rate} = 514/528 \times 41118/41120 \times 660/637 \times 24\,883\,200$ kbit/s.<br>NOTE 4 – The OTU50u bit rate can be based on the OTU50u-RS bit rate as follows: $514/544 \times 41118/41120 \times \text{OTU50u-RS bit rate} = 514/544 \times 41118/41120 \times 680/637 \times 49\,766\,400$ kbit/s. |                                        |                        |
+
+**Table L.2 – ODU types and bit rates**
+
+| ODU type                                                                                                          | ODU nominal bit rate                   | ODU bit-rate tolerance |
+|-------------------------------------------------------------------------------------------------------------------|----------------------------------------|------------------------|
+| ODU25u                                                                                                            | $2937/2912 \times 24\,883\,200$ kbit/s | $\pm 20$ ppm           |
+| ODU50u                                                                                                            | $2937/2912 \times 49\,766\,400$ kbit/s |                        |
+| NOTE 1 – The nominal ODU rates are approximately: 25 096 826.374 kbit/s (ODU25u), 50 193 652.747 kbit/s (ODU50u). |                                        |                        |
+
+**Table L.3 – OPU types and bit rates**
+
+| OPU type                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                | OPU payload nominal bit rate             | OPU payload bit-rate tolerance |
+|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------|--------------------------------|
+| OPU25u                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  | $49929/49712 \times 24\,883\,200$ kbit/s | $\pm 20$ ppm                   |
+| OPU50u                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  | $49929/49712 \times 49\,766\,400$ kbit/s |                                |
+| NOTE 1 – The nominal OPU payload rates are approximately: 24 991 818.732 kbit/s (OPU25u Payload), 49 983 637.464 kbit/s (OPU50u Payload).<br>NOTE 2 – The OPU25u bit rate can be based on the OTU25u-RS bit rate as follows: $238/239 \times 514/528 \times 41118/41120 \times \text{OTU25u-RS bit rate} = 238/239 \times 514/528 \times 41118/41120 \times 660/637 \times 24\,883\,200$ kbit/s.<br>NOTE 3 – The OTU50u bit rate can be based on the OTU50u-RS bit rate as follows: $5238/239 \times 14/544 \times 41118/41120 \times \text{OTU50u-RS bit rate} = 238/239 \times 514/544 \times 41118/41120 \times 680/637 \times 49\,766\,400$ kbit/s. |                                          |                                |
+
+**Table L.4 – OTU/ODU/OPU frame periods**
+
+| OTU/ODU/OPU type                                                         | Period (Note)       |
+|--------------------------------------------------------------------------|---------------------|
+| OTU25u/ODU25u/OPU25u                                                     | 4.876 $\mu\text{s}$ |
+| OTU50u/ODU50u/OPU50u                                                     | 2.483 $\mu\text{s}$ |
+| NOTE – The period is an approximated value, rounded to 3 decimal places. |                     |
+
+**Table L.5 – OPUk multiframe periods for 1.25G tributary slots**
+
+| OPU type                                                                 | 1.25G tributary slot multiframe period (Note) |
+|--------------------------------------------------------------------------|-----------------------------------------------|
+| OPU25u                                                                   | 97.517 µs                                     |
+| OPU50u                                                                   | 97.517 µs                                     |
+| NOTE – The period is an approximated value, rounded to 3 decimal places. |                                               |
+
+**Table L.6 – ODTU payload bandwidth (kbit/s)**
+
+| ODTU type                                                                   | ODTU payload nominal bandwidth    |                    | ODTU payload bit-rate tolerance |
+|-----------------------------------------------------------------------------|-----------------------------------|--------------------|---------------------------------|
+|                                                                             | Minimum                           | Nominal            | Maximum                         |
+| ODTU25u.ts                                                                  | ts × 190.4/3824 × ODU25u bit rate |                    | ±20 ppm                         |
+| ODTU50u.ts                                                                  | ts × 95.2/3824 × ODU50u bit rate  |                    |                                 |
+| ODTU25u.ts, ODTU50u.ts                                                      | ts × 1 249 565.945                | ts × 1 249 590.937 | ts × 1 249 615.928              |
+| NOTE – The bandwidth is an approximated value, rounded to 3 decimal places. |                                   |                    |                                 |
+
+**Table L.7 – Number of tributary slots required for ODUj into OPU25u and OPU50u**
+
+|                                                                 | # 1.25G tributary slots |        |
+|-----------------------------------------------------------------|-------------------------|--------|
+|                                                                 | OPU25u                  | OPU50u |
+| ODU0                                                            | 1                       | 1      |
+| ODU1                                                            | 2                       | 2      |
+| ODU2                                                            | 9                       | 9      |
+| ODU2e                                                           | 9                       | 9      |
+| ODU3                                                            | –                       | 33     |
+| ODUflex(CBR)                                                    |                         |        |
+| – ODUflex(25GBase-R)                                            | –                       | 21     |
+| – ODUflex(50GBase-R)                                            | –                       | –      |
+| ODUflex(GFP)                                                    | Note                    | Note   |
+| – ODUflex(GFP,8,2) for 10GBASE-R                                | 8                       | 8      |
+| – ODUflex(GFP,20,2) for 25GBASE-R                               | 20                      | 20     |
+| – ODUflex(GFP,40,2) for 50GBASE-R                               | 40                      | 40     |
+| – ODUflex(GFP,n,2), 1 ≤ n ≤ 20 (OPU25u) and 1 ≤ n ≤ 40 (OPU50u) | n                       | n      |
+| – ODUflex(GFP,n,3), 9 ≤ n ≤ 19 (OPU25u) and 9 ≤ n ≤ 32 (OPU50u) | n+1                     | n+1    |
+| – ODUflex(GFP,n,4), 33 ≤ n ≤ 38 (OPU50u)                        | –                       | n+2    |
+| ODUflex(IMP)                                                    | Note                    | Note   |
+| – ODUflex(IMP,s)                                                | Note                    | Note   |
+| NOTE – Refer to equations 19-1a and 19-1b in clauses 19.6.      |                         |        |
+
+## Appendix I
+
+### Range of stuff ratios for asynchronous mappings of CBR2G5, CBR10G, and CBR40G clients with $\pm 20$ ppm bit-rate tolerance into OPUk, and for asynchronous multiplexing of ODUj into ODUk ( $k > j$ )
+
+(This appendix does not form an integral part of this Recommendation.)
+
+Clause 17.2 describes asynchronous and bit-synchronous mappings of CBR2G5, CBR10G, and CBR40G clients with  $\pm 20$  ppm bit-rate tolerance into ODU1, 2, and 3, respectively. Clause 19 describes asynchronous mapping (multiplexing) of ODUj into ODUk ( $k > j$ ). For asynchronous CBR client mappings, any frequency difference between the client and local OPUk server clocks is accommodated by the  $+1/0/-1$  justification scheme. For asynchronous multiplexing of ODUj into ODUk ( $k > j$ ), any frequency difference between the client ODUj and local OPUk server clocks is accommodated by the  $+2/+1/0/-1$  justification scheme. The OPUk payload, ODUk, and OTUk bit rates and tolerances are given in clause 7.3. The ODU1, ODU2, and ODU3 rates are 239/238, 239/237, and 239/236 times 2 488 320 kbit/s, 9 953 280 kbit/s, and 39 813 120 kbit/s, respectively. The ODUk bit-rate tolerances are  $\pm 20$  ppm. This appendix shows that each justification scheme can accommodate these bit rates and tolerances for the respective mappings, and also derives the range of justification (stuff) ratio for each mapping.
+
+The  $+1/0/-1$  mapping in clause 17.2 provides for one positive justification opportunity (PJO) and one negative justification opportunity (NJO) in each ODUk frame. The  $+2/+1/0/-1$  mapping in clause 19 provides for 2 PJOs and one NJO in each ODUk frame. For the case of ODU multiplexing (i.e., the latter case), the ODUj being mapped will get only a fraction of the full payload capacity of the ODUk. There can be, in general, a number of fixed stuff bytes per ODUj or CBR client. Note that in both mapping cases, there is one stuff opportunity in every ODUk frame. For mapping of a CBR client into ODUk, the CBR client is allowed to use all the stuff opportunities (because only one CBR client signal is mapped into an ODUk). However, for mapping ODUj into ODUk ( $k > j$ ), the ODUj can only use  $1/2$  (ODU0 into ODU1),  $1/4$  (ODU1 into ODU2 or ODU2 into ODU3) or  $1/16$  (ODU1 into ODU3) of the stuff opportunities. The other stuff opportunities are needed for the other clients being multiplexed into the ODUk.
+
+Traditionally, the justification ratio (stuff ratio) for purely positive justification schemes is defined as the long-run average fraction of justification opportunities for which a justification is done (i.e., for a very large number of frames, the ratio of the number of justifications to the total number of justification opportunities). In the  $+1/0/-1$  scheme, positive and negative justifications must be distinguished. This is done by using different algebraic signs for positive and negative justifications. With this convention, the justification ratio can vary at most (for sufficiently large frequency offsets) from  $-1$  to  $+1$  (in contrast to a purely positive justification scheme, where the justification ratio can vary at most from  $0$  to  $1$ ). In the case of ODUk multiplexing, the justification ratio is defined relative to the stuff opportunities available for the client in question. Then, the justification ratio can vary (for sufficiently large frequency offsets) from  $-1$  to  $+2$ . (If the justification ratio were defined relative to all the stuff opportunities for all the clients, the range would be  $-1/2$  to  $+1$  for multiplexing ODU0 into ODU1,  $-1/4$  to  $+1/2$  for multiplexing ODU1 into ODU2 and ODU2 into ODU3, and  $-1/16$  to  $+1/8$  for multiplexing ODU1 into ODU3.)
+
+Let  $\alpha$  represent the justification ratio ( $-1 \leq \alpha \leq 1$  for CBR client into ODUk mapping;  $-2 \leq \alpha \leq 1$  for ODUj into ODUk mapping ( $k > j$ )), and use the further convention that positive  $\alpha$  will correspond to negative justification and negative  $\alpha$  to positive justification (the reason for this convention is explained below).
+
+Define the following notation (the index  $j$  refers to the possible ODU $j$  client being mapped, and the index  $k$  refers to the ODU $k$  server layer into which the ODU $j$  or CBR client is mapped):
+
+$N$  = number of fixed stuff bytes in the OPU $k$  payload area associated with the client in question (note that this is not the total number of fixed stuff bytes if multiple clients are being multiplexed)
+
+$S$  = nominal STM- $N$  or ODU $j$  client rate (bytes/s)
+
+$T$  = nominal ODU $k$  frame period(s)
+
+$y_c$  = client frequency offset (fraction)
+
+$y_s$  = server frequency offset (fraction)
+
+$p$  = fraction of OPU $k$  payload area available to this client
+
+$N_f$  = average number of client bytes mapped into an ODU $k$  frame, for the particular frequency offsets (averaged over a large number of frames)
+
+Then  $N_f$  is given by:
+
+$$N_f = ST \frac{1 + y_c}{1 + y_s} \quad (\text{I-1})$$
+
+For frequency offsets small compared to 1, this may be approximated:
+
+$$N_f = ST(1 + y_c - y_s) \equiv ST\beta \quad (\text{I-2})$$
+
+The quantity  $\beta - 1$  is the net frequency offset due to client and server frequency offset.
+
+Now, the average number of client bytes mapped into an ODU $k$  frame is also equal to the total number of bytes in the payload area available to this client (which is  $(4)(3808)p = 15232p$ ), minus the number of fixed stuff bytes for this client ( $N$ ), plus the average number of bytes stuffed for this client over a very large number of frames. The latter is equal to the justification ratio  $\alpha$  multiplied by the fraction of frames  $p$  corresponding to justification opportunities for this client. Combining this with equation I-1 produces:
+
+$$ST\beta + \alpha p + 15232p - N \quad (\text{I-3})$$
+
+In equation I-3, a positive  $\alpha$  corresponds to more client bytes mapped into the ODU $k$ , on average. As indicated above, this corresponds to negative justification. This sign convention is used so that  $\alpha$  enters in equation I-3 with a positive sign (for convenience).
+
+Equation I-3 is the main result. For mapping STM- $N$  (CBR clients) into ODU $k$ , the quantity  $p$  is 1.
+
+The range of stuff ratio may now be determined for mapping STM- $N$  or ODU $j$  clients into ODU $k$ , using equation I-3. In what follows, let  $R_{16}$  be the STM-16 rate, i.e.,  $2.48832 \text{ Gbit/s} = 3.1104 \times 10^8 \text{ bytes/s}$ .
+
+### Asynchronous mapping of CBR2G5 (2 488 320 kbit/s) signal into ODU1
+
+The nominal client rate is  $S = R_{16}$ . The nominal ODU1 rate is  $(239/238)S$  (see clause 7.3). But the nominal ODU1 rate is also equal to  $(4)(3824)/T$ . Then:
+
+$$ST = (4)(3824) \frac{238}{239} = 15232 \quad (\text{I-4})$$
+
+Inserting this into equation I-3, and using the fact that  $N = 0$  (no fixed stuff bytes) for this mapping produces:
+
+$$\alpha = 15232(\beta - 1) \quad (\text{I-5})$$
+
+Since the ODUk and client frequency tolerances are each  $\pm 20$  ppm,  $\beta$  ranges from 0.99996 to 1.00004. Using this in equation I-5 gives as the range of  $\alpha$ :
+
+$$-0.60928 \leq \alpha \leq +0.60928 \quad (\text{I-6})$$
+
+#### Asynchronous mapping of CBR10G (9 953 280 kbit/s) signal into ODU2
+
+The nominal client rate is  $S = 4R_{16}$ . The nominal ODU2 rate is  $(239/237)S$  (see clause 7.3). But the nominal ODU2 rate is also equal to  $(4)(3824)/T$ . Then:
+
+$$ST = (4)(3824) \frac{237}{239} = 15168 \quad (\text{I-7})$$
+
+Inserting this into equation I-3, and using the fact that  $N = 64$  (number of fixed stuff bytes) for this mapping produces:
+
+$$\alpha = 15168\beta + 64 - 15232 = 15168(\beta - 1) \quad (\text{I-8})$$
+
+As before, the ODUk and client frequency tolerances are  $\pm 20$  ppm, and  $\beta$  ranges from 0.99996 to 1.00004. Using this in equation I-8 gives as the range of  $\alpha$ :
+
+$$-0.60672 \leq \alpha \leq +0.60672 \quad (\text{I-9})$$
+
+#### Asynchronous mapping of CBR40G (39 813 120 kbit/s) signal into ODU3
+
+The nominal client rate is  $S = 16R_{16}$ . The nominal ODU3 rate is  $(239/236)S$  (see clause 7.3). But the nominal ODU3 rate is also equal to  $(4)(3824)/T$ . Then:
+
+$$ST = (4)(3824) \frac{236}{239} = 15104 \quad (\text{I-10})$$
+
+Inserting this into equation I-3, and using the fact that  $N = 128$  (number of fixed stuff bytes) for this mapping produces:
+
+$$\alpha = 15104\beta + 128 - 15232 = 15104(\beta - 1) \quad (\text{I-11})$$
+
+As before, the ODUk and client frequency tolerances are  $\pm 20$  ppm, and  $\beta$  ranges from 0.99996 to 1.00004. Using this in equation I-11 gives as the range of  $\alpha$ :
+
+$$-0.60416 \leq \alpha \leq +0.60416 \quad (\text{I-12})$$
+
+#### ODU1 into ODU2 multiplexing
+
+The ODU1 nominal client rate is (see clause 7.3):
+
+$$S = \frac{239}{238} R_{16} \quad (\text{I-13})$$
+
+The ODU2 nominal frame time is:
+
+$$T = \frac{(3824)(4)}{\frac{239}{237}(4R_{16})} \quad (\text{I-14})$$
+
+The fraction  $p$  is 0.25. Inserting into equation I-3 produces:
+
+$$\frac{239}{238} R_{16} \frac{(3824)(4)}{\frac{239}{237}(4R_{16})} \beta = \frac{\alpha}{4} + 3808 - N \quad (\text{I-15})$$
+
+Simplifying and solving for  $\alpha$  produces:
+
+$$\alpha = \frac{237}{238}(15296)\beta + 4N - 15232 \quad (\text{I-16})$$
+
+Now let  $\beta = 1 + y$ , where  $y$  is the net frequency offset (and is very nearly equal to  $y_c - y_s$  for client and server frequency offset small compared to 1). Then:
+
+$$\begin{aligned} \alpha &= \frac{237}{238}(15296) - 15232 + 4N + \frac{237}{238}(15296)y \\ &= 4N - 0.2689076 + 15231.731092y \end{aligned} \quad (\text{I-17})$$
+
+The number of fixed stuff bytes  $N$  is zero, as given in clause 19.5.1. The client and mapper frequency offsets are in the range  $\pm 20$  ppm, as given in clause 7.3. Then, the net frequency offset  $y$  is in the range  $\pm 40$  ppm. Inserting these values into equation I-17 gives for the range for  $\alpha$ :
+
+$$\begin{aligned} \alpha &= 0.340362 && \text{for } y = +40 \text{ ppm} \\ \alpha &= -0.268908 && \text{for } y = 0 \text{ ppm} \\ \alpha &= -0.878177 && \text{for } y = -40 \text{ ppm} \end{aligned} \quad (\text{I-18})$$
+
+In addition, stuff ratios of  $-2$  and  $+1$  are obtained for frequency offsets of  $-113.65$  ppm and  $83.30$  ppm, respectively. The range of frequency offset that can be accommodated is approximately  $197$  ppm. This is 50% larger than the range that can be accommodated by a  $+1/0/-1$  justification scheme (see above), and is due to the additional positive stuff byte.
+
+### ODU2 into ODU3 multiplexing
+
+The ODU2 nominal client rate is (see clause 7.3):
+
+$$S = \frac{239}{237}(4R_{16}) \quad (\text{I-19})$$
+
+The ODU3 nominal frame time is:
+
+$$T = \frac{(3824)(4)}{\frac{239}{236}(16R_{16})} \quad (\text{I-20})$$
+
+The fraction  $p$  is 0.25. Inserting into equation I-3 produces:
+
+$$\frac{239}{237} 4R_{16} \frac{(3824)(4)}{\frac{239}{236}(16R_{16})} \beta = \frac{\alpha}{4} + 3808 - N \quad (\text{I-21})$$
+
+Simplifying and solving for  $\alpha$  produces:
+
+$$\alpha = \frac{236}{237}(15296)\beta + 4N - 15232 \quad (\text{I-22})$$
+
+As before, let  $\beta = 1 + y$ , where  $y$  is the net frequency offset (and is very nearly equal to  $y_c - y_s$  for client and server frequency offset small compared to 1). Then:
+
+$$\begin{aligned} \alpha &= \frac{236}{237}(15296) - 15232 + 4N + \frac{236}{237}(15296)y \\ &= 4N - 0.5400844 + 15231.459916y \end{aligned} \quad (\text{I-23})$$
+
+The number of fixed stuff bytes  $N$  is zero, as given in clause 19.5.3. The client and mapper frequency offsets are in the range  $\pm 20$  ppm, as given in clause 7.3. Then, the net frequency offset  $y$  is in the range  $\pm 40$  ppm. Inserting these values into equation I-23 gives for the range for  $\alpha$ :
+
+$$\begin{aligned} \alpha &= 0.0691740 & \text{for } y &= +40 \text{ ppm} \\ \alpha &= -0.5400844 & \text{for } y &= 0 \text{ ppm} \\ \alpha &= -1.149343 & \text{for } y &= -40 \text{ ppm} \end{aligned} \quad (\text{I-24})$$
+
+In addition, stuff ratios of  $-2$  and  $+1$  are obtained for frequency offsets of  $-95.85$  ppm and  $101.11$  ppm, respectively. As above, the range of frequency offset that can be accommodated is approximately  $197$  ppm, which is  $50\%$  larger than the range that can be accommodated by a  $+1/0/-1$  justification scheme (see above) due to the additional positive stuff byte.
+
+### ODU1 into ODU3 multiplexing
+
+The ODU1 nominal client rate is (see clause 7.3):
+
+$$S = \frac{239}{238}(R_{16}) \quad (\text{I-25})$$
+
+The ODU3 nominal frame time is:
+
+$$T = \frac{(3824)(4)}{\frac{239}{236}(16R_{16})} \quad (\text{I-26})$$
+
+The fraction  $p$  is  $0.0625$ . Inserting into equation I-3 produces:
+
+$$\frac{239}{238} R_{16} \frac{(3824)(4)}{\frac{239}{236}(16R_{16})} \beta = \frac{\alpha}{16} + 952 - N \quad (\text{I-27})$$
+
+Simplifying and solving for  $\alpha$  produces:
+
+$$\alpha = \frac{236}{238}(15296)\beta + 16N - 15232 \quad (\text{I-28})$$
+
+As before, let  $\beta = 1 + y$ , where  $y$  is the net frequency offset (and is very nearly equal to  $y_c - y_s$  for client and server frequency offset small compared to 1). Then:
+
+$$\begin{aligned} \alpha &= \frac{236}{238}(15296) - 15232 + 16N + \frac{236}{238}(15296)y \\ &= 16N - 64.5378151 + 15167.462185y \end{aligned} \quad (\text{I-29})$$
+
+The total number of fixed stuff bytes in the ODU3 payload is  $64$ , as given in clause 19.5.2; the number for one ODU1 client,  $N$ , is therefore  $4$ . The client and mapper frequency offsets are in the range  $\pm 20$  ppm, as given in clause 7.3. Then, the net frequency offset  $y$  is in the range  $\pm 40$  ppm. Inserting these values into equation I-29 gives for the range for  $\alpha$ :
+
+$$\begin{aligned} \alpha &= 0.0688834 & \text{for } y &= +40 \text{ ppm} \\ \alpha &= -0.5378151 & \text{for } y &= 0 \text{ ppm} \\ \alpha &= -1.144514 & \text{for } y &= -40 \text{ ppm} \end{aligned} \quad (\text{I-30})$$
+
+In addition, stuff ratios of  $-2$  and  $+1$  are obtained for frequency offsets of  $-96.40$  ppm and  $101.39$  ppm, respectively. As above, the range of frequency offset that can be accommodated is approximately  $197$  ppm, which is  $50\%$  larger than the range that can be accommodated by a  $+1/0/-1$  justification scheme (see above) due to the additional positive stuff byte.
+
+### ODU0 into ODU1 multiplexing
+
+The ODU0 nominal client rate is (see clause 7.3):
+
+$$S = \frac{1}{2}(R_{16}) \quad (\text{I-31})$$
+
+The ODU1 nominal frame time is:
+
+$$T = \frac{(3824)(4)}{\frac{239}{238}(R_{16})} \quad (\text{I-32})$$
+
+The fraction  $p$  is  $0.5$ . Inserting into equation I-3 produces:
+
+$$\frac{1}{2} R_{16} \frac{(3824)(4)}{\frac{239}{238}(R_{16})} \beta = \frac{\alpha}{2} + 7616 - N \quad (\text{I-33})$$
+
+Simplifying and solving for  $\alpha$  produces:
+
+$$\alpha = \frac{238}{239}(15296)\beta + 2N - 15232 \quad (\text{I-34})$$
+
+As before, let  $\beta = 1 + y$ , where  $y$  is the net frequency offset (and is very nearly equal to  $y_c - y_s$  for client and server frequency offset small compared to  $1$ ). Then:
+
+$$\begin{aligned} \alpha &= \frac{238}{239}(15296) - 15232 + 2N + \frac{238}{239}(15296)y \\ &= 2N + 15232y \end{aligned} \quad (\text{I-35})$$
+
+The total number of fixed stuff bytes  $N$  is zero, as given in clause 19.5.4. The client and mapper frequency offsets are in the range  $\pm 20$  ppm, as given in clause 7.3. Then, the net frequency offset  $y$  is in the range  $\pm 40$  ppm. Inserting these values into equation I-35 gives for the range for  $\alpha$ :
+
+$$\begin{aligned} \alpha &= 0.6092800 && \text{for } y = +40 \text{ ppm} \\ \alpha &= 0.0000000 && \text{for } y = 0 \text{ ppm} \\ \alpha &= -0.6092800 && \text{for } y = -40 \text{ ppm} \end{aligned} \quad (\text{I-36})$$
+
+In addition, stuff ratios of  $-2$  and  $+1$  are obtained for frequency offsets of  $-130$  ppm and  $65$  ppm, respectively. As above, the range of frequency offset that can be accommodated is approximately  $195$  ppm.
+
+## Appendix II
+
+### Examples of functionally standardized OTU frame structures
+
+(This appendix does not form an integral part of this Recommendation.)
+
+This appendix provides examples of functionally standardized OTU frame structures. These examples are for illustrative purposes and by no means imply a definition of such structures. The completely standardized OTUk frame structure as defined in this Recommendation is shown in Figure II.1. Functionally standardized OTUkV frame structures will be needed to support, e.g., alternative FEC. Examples of OTUkV frame structures are:
+
+- OTUkV with the same overhead byte allocation as the OTUk, but use of an alternative FEC as shown in Figure II.2;
+- OTUkV with the same overhead byte allocation as the OTUk, but use of a smaller, alternative FEC code and the remainder of the OTUkV FEC overhead area filled with fixed stuff as shown in Figure II.3;
+- OTUkV with a larger FEC overhead byte allocation as the OTUk, and use of an alternative FEC as shown in Figure II.4;
+- OTUkV with no overhead byte allocation for FEC as shown in Figure II.5;
+- OTUkV with a different frame structure than the OTUk frame structure, supporting a different OTU overhead (OTUkV overhead and OTUkV FEC) as shown in Figure II.6;
+- OTUkV with a different frame structure than the OTUk frame structure, supporting a different OTU overhead (OTUkV overhead) and with no overhead byte allocation for FEC as shown in Figure II.7.
+
+![](849a212bb698e5387989fe9100b12c7c_img.jpg)
+
+Column #
+
+|       | 1 | ..... | 14      | 15                  | 16 | 17 | 3824 | 3825 | .....                              | 4080 |  |  |  |  |  |  |
+|-------|---|-------|---------|---------------------|----|----|------|------|------------------------------------|------|--|--|--|--|--|--|
+| Row # | 1 | FA OH | OTUk OH | OTUk payload = ODUk |    |    |      |      | Row 1 RS (255, 239) FEC redundancy |      |  |  |  |  |  |  |
+|       | 2 |       |         |                     |    |    |      |      | Row 2 RS (255, 239) FEC redundancy |      |  |  |  |  |  |  |
+|       | 3 |       |         |                     |    |    |      |      | Row 3 RS (255, 239) FEC redundancy |      |  |  |  |  |  |  |
+|       | 4 |       |         |                     |    |    |      |      | Row 4 RS (255, 239) FEC redundancy |      |  |  |  |  |  |  |
+
+G.709-Y.1331(12)\_FII.1
+
+Figure II.1 – OTUk (with RS(255,239) FEC)
+
+![](035b1a67ac3f04ae2f5218c450186c9a_img.jpg)
+
+Column #
+
+|       | 1 | .....   | 14      | 15   | 16 | 17 | 3824 | 3825 | .....     | 4080 |  |  |  |  |  |  |  |  |
+|-------|---|---------|---------|------|----|----|------|------|-----------|------|--|--|--|--|--|--|--|--|
+| Row # | 1 | FA OH   | OTUk OH | OPUk |    |    |      |      | OTUkV FEC |      |  |  |  |  |  |  |  |  |
+|       | 2 | ODUk OH |         |      |    |    |      |      |           |      |  |  |  |  |  |  |  |  |
+|       | 3 |         |         |      |    |    |      |      |           |      |  |  |  |  |  |  |  |  |
+|       | 4 |         |         |      |    |    |      |      |           |      |  |  |  |  |  |  |  |  |
+
+G.709-Y.1331(12)\_FII.2
+
+Figure II.2 – OTUk with alternative OTUkV FEC (OTUk-v)
+
+![Diagram of OTUk frame structure with a smaller OTUkV FEC area. The frame is 4 rows by 4080 columns. Row 1 contains FA OH (columns 1-14), OTUk OH (columns 15-17), and then a gap. Row 2 contains ODUk OH (columns 1-14), OPUk (columns 15-3824), OTUkV FEC (columns 3825-4080), and Fixed stuff (All-0s) (columns 3825-4080). Row 3 contains ODUk OH (columns 1-14), OPUk (columns 15-3824), OTUkV FEC (columns 3825-4080), and Fixed stuff (All-0s) (columns 3825-4080). Row 4 contains ODUk OH (columns 1-14), OPUk (columns 15-3824), OTUkV FEC (columns 3825-4080), and Fixed stuff (All-0s) (columns 3825-4080).](e29078e7dcd6e581ecf7f35dc8220202_img.jpg)
+
+G.709-Y.1331(12)\_FII.3
+
+Diagram of OTUk frame structure with a smaller OTUkV FEC area. The frame is 4 rows by 4080 columns. Row 1 contains FA OH (columns 1-14), OTUk OH (columns 15-17), and then a gap. Row 2 contains ODUk OH (columns 1-14), OPUk (columns 15-3824), OTUkV FEC (columns 3825-4080), and Fixed stuff (All-0s) (columns 3825-4080). Row 3 contains ODUk OH (columns 1-14), OPUk (columns 15-3824), OTUkV FEC (columns 3825-4080), and Fixed stuff (All-0s) (columns 3825-4080). Row 4 contains ODUk OH (columns 1-14), OPUk (columns 15-3824), OTUkV FEC (columns 3825-4080), and Fixed stuff (All-0s) (columns 3825-4080).
+
+**Figure II.3 – OTUk with a smaller OTUkV FEC and the remainder of an FEC area filled with fixed stuff**
+
+![Diagram of OTUk frame structure with a larger OTUkV FEC area. The frame is 4 rows by X columns. Row 1 contains FA OH (columns 1-14), OTUk OH (columns 15-17), and then a gap. Row 2 contains ODUk OH (columns 1-14), OPUk (columns 15-3824), and OTUkV FEC (columns 3825-X). Row 3 contains ODUk OH (columns 1-14), OPUk (columns 15-3824), and OTUkV FEC (columns 3825-X). Row 4 contains ODUk OH (columns 1-14), OPUk (columns 15-3824), and OTUkV FEC (columns 3825-X).](87f2c7d96e398885a4108ecbf1aa9499_img.jpg)
+
+G.709-Y.1331(12)\_FII.4
+
+Diagram of OTUk frame structure with a larger OTUkV FEC area. The frame is 4 rows by X columns. Row 1 contains FA OH (columns 1-14), OTUk OH (columns 15-17), and then a gap. Row 2 contains ODUk OH (columns 1-14), OPUk (columns 15-3824), and OTUkV FEC (columns 3825-X). Row 3 contains ODUk OH (columns 1-14), OPUk (columns 15-3824), and OTUkV FEC (columns 3825-X). Row 4 contains ODUk OH (columns 1-14), OPUk (columns 15-3824), and OTUkV FEC (columns 3825-X).
+
+**Figure II.4 – OTUk with a larger OTUkV FEC**
+
+![Diagram of OTUk frame structure without an OTUkV FEC area. The frame is 4 rows by 3824 columns. Row 1 contains FA OH (columns 1-14), OTUk OH (columns 15-17), and then a gap. Row 2 contains ODUk OH (columns 1-14) and OPUk (columns 15-3824). Row 3 contains ODUk OH (columns 1-14) and OPUk (columns 15-3824). Row 4 contains ODUk OH (columns 1-14) and OPUk (columns 15-3824).](d4a6d3795fe79e002987abc462a30f61_img.jpg)
+
+G.709-Y.1331(12)\_FII.5
+
+Diagram of OTUk frame structure without an OTUkV FEC area. The frame is 4 rows by 3824 columns. Row 1 contains FA OH (columns 1-14), OTUk OH (columns 15-17), and then a gap. Row 2 contains ODUk OH (columns 1-14) and OPUk (columns 15-3824). Row 3 contains ODUk OH (columns 1-14) and OPUk (columns 15-3824). Row 4 contains ODUk OH (columns 1-14) and OPUk (columns 15-3824).
+
+**Figure II.5 – OTUk without an OTUkV FEC area**
+
+![Diagram of OTUkV frame structure with a different frame structure. The frame is Y rows by X1 + X2 + X3 columns. Row 1 contains OTUkV overhead (Y x X1 bytes) in columns 1 to X1, OTUkV payload = ODUk in columns X1 + 1 to X1 + X2, and OTUkV FEC (Y x X3 bytes) in columns X1 + X2 + 1 to X1 + X2 + X3. Row Y contains the same structure.](c7973a89da29a4a59561e36561984333_img.jpg)
+
+G.709-Y.1331(12)\_FII.6
+
+Diagram of OTUkV frame structure with a different frame structure. The frame is Y rows by X1 + X2 + X3 columns. Row 1 contains OTUkV overhead (Y x X1 bytes) in columns 1 to X1, OTUkV payload = ODUk in columns X1 + 1 to X1 + X2, and OTUkV FEC (Y x X3 bytes) in columns X1 + X2 + 1 to X1 + X2 + X3. Row Y contains the same structure.
+
+**Figure II.6 – OTUkV with a different frame structure**
+
+![Diagram of OTUkV frame structure with a different frame structure and without FEC area. The frame is Y rows by X1 + X2 columns. Row 1 contains OTUkV overhead (Y x X1 bytes) in columns 1 to X1 and OTUkV payload = ODUk in columns X1 + 1 to X1 + X2. Row Y contains the same structure.](fd33a3e091898c76820cfaf041c23411_img.jpg)
+
+G.709-Y.1331(12)\_FII.7
+
+Diagram of OTUkV frame structure with a different frame structure and without FEC area. The frame is Y rows by X1 + X2 columns. Row 1 contains OTUkV overhead (Y x X1 bytes) in columns 1 to X1 and OTUkV payload = ODUk in columns X1 + 1 to X1 + X2. Row Y contains the same structure.
+
+**Figure II.7 – OTUkV with a different frame structure and without FEC area**
+
+For the case of Figures II.6 and II.7, the mapping of the ODUk signal can be either asynchronous, bit-synchronous, or frame synchronous.
+
+For the case of asynchronous mapping, the ODUk and OTUkV bit rates can be asynchronous. The ODUk signal is mapped as a bit stream into the OTUkV payload area using a stuffing technique.
+
+For the case of bit-synchronous mapping, the ODUk and OTUkV bit rates are synchronous. The ODUk signal is mapped into the OTUkV payload area without stuffing. The ODUk frame is not related to the OTUkV frame.
+
+For the case of a frame synchronous mapping, the ODUk and OTUkV bit rates are synchronous and the frame structures are aligned. The ODUk signal is mapped into the OTUkV payload area without stuffing and with a fixed position of the ODUk frame within the OTUkV frame. (See Figure II.8.)
+
+![Diagram illustrating the mapping of ODUk into OTUkV. The top part shows the OTUkV frame structure with columns 1 to X1 for overhead, X1+1 to X1+X2 for payload, and X1+X2+1 to X1+X2+X3 for FEC. The bottom part shows the ODUk frame structure with columns 1 to 14 for FA OH, 15 to 17 for OPUk overhead, and 18 to 3824 for ODUk payload. An arrow indicates the mapping of the ODUk payload into the OTUkV payload area.](054a529346bd51a9f77b43a46b991748_img.jpg)
+
+The diagram illustrates the mapping of an ODUk frame into an OTUkV frame. The OTUkV frame is shown as a grid with Y rows and columns. The columns are divided into three sections: OTUkV overhead (columns 1 to  $X_1$ ), OTUkV payload (columns  $X_1 + 1$  to  $X_1 + X_2$ ), and OTUkV FEC (columns  $X_1 + X_2 + 1$  to  $X_1 + X_2 + X_3$ ). The ODUk frame is shown below, with columns 1 to 14 for FA OH, columns 15 to 17 for OPUk overhead, and columns 18 to 3824 for ODUk payload. An arrow points from the ODUk payload area to the OTUkV payload area, indicating the mapping of the ODUk signal into the OTUkV frame.
+
+Diagram illustrating the mapping of ODUk into OTUkV. The top part shows the OTUkV frame structure with columns 1 to X1 for overhead, X1+1 to X1+X2 for payload, and X1+X2+1 to X1+X2+X3 for FEC. The bottom part shows the ODUk frame structure with columns 1 to 14 for FA OH, 15 to 17 for OPUk overhead, and 18 to 3824 for ODUk payload. An arrow indicates the mapping of the ODUk payload into the OTUkV payload area.
+
+G.709-Y.1331(12)\_FII.8
+
+Figure II.8 – Asynchronous (or bit-synchronous) mapping of ODUk into OTUkV
+
+## Appendix III
+
+### Example of ODUk multiplexing
+
+(This appendix does not form an integral part of this Recommendation.)
+
+Figure III.1 illustrates the multiplexing of four ODU1 signals into an ODU2. The ODU1 signals including the frame alignment overhead and an all-0s pattern in the OTUk overhead locations are adapted to the ODU2 clock via justification (asynchronous mapping). These adapted ODU1 signals are byte interleaved into the OPU2 payload area, and their justification control and opportunity signals (JC, NJO) are frame interleaved into the OPU2 overhead area.
+
+ODU2 overhead is added after which the ODU2 is mapped into the OTU2 [or OTU2V]. OTU2 [or OTU2V] overhead and frame alignment overhead are added to complete the signal for transport via an OTM signal.
+
+![Diagram illustrating the multiplexing of four ODU1 signals into an ODU2, and then into an OTU2. The diagram shows three levels of signal structure: ODU1, ODU2, and OTU2. ODU1 consists of Alignment (yellow), ODU1 OH (red), OPU1 OH (yellow), and Client layer signal (purple). ODU2 consists of Alignment (yellow), ODU2 OH (red), OPU2 OH (yellow), and a payload area containing four interleaved ODU1 signals. OTU2 consists of Alignment (yellow), OTU2 OH (green), ODU2 OH (red), OPU2 OH (yellow), the four interleaved ODU1 signals, and OTU2 FEC (green). A '4x' multiplier indicates that four ODU1 signals are multiplexed into one ODU2. A dashed line connects the ODU2 payload area to a detailed view of the four interleaved ODU1 signals. The diagram is labeled G.709-Y.1331(12)_FIII.1 at the bottom right.](8b989840720118a1b720745e35a79346_img.jpg)
+
+G.709-Y.1331(12)\_FIII.1
+
+Diagram illustrating the multiplexing of four ODU1 signals into an ODU2, and then into an OTU2. The diagram shows three levels of signal structure: ODU1, ODU2, and OTU2. ODU1 consists of Alignment (yellow), ODU1 OH (red), OPU1 OH (yellow), and Client layer signal (purple). ODU2 consists of Alignment (yellow), ODU2 OH (red), OPU2 OH (yellow), and a payload area containing four interleaved ODU1 signals. OTU2 consists of Alignment (yellow), OTU2 OH (green), ODU2 OH (red), OPU2 OH (yellow), the four interleaved ODU1 signals, and OTU2 FEC (green). A '4x' multiplier indicates that four ODU1 signals are multiplexed into one ODU2. A dashed line connects the ODU2 payload area to a detailed view of the four interleaved ODU1 signals. The diagram is labeled G.709-Y.1331(12)\_FIII.1 at the bottom right.
+
+NOTE – The ODU1 floats in a quarter of the OPU2 payload area. An ODU1 frame will cross multiple ODU2 frame boundaries. A complete ODU1 frame (15296 bytes) requires the bandwidth of (15296/3808) 4.017 ODU2 frames. This is not illustrated.
+
+**Figure III.1 – Example of multiplexing 4 ODU1 signals into an ODU2**
+
+Figure III.2 illustrates the multiplexing of two ODU0 signals into an ODU1. The ODU0 signals including the frame alignment overhead and an all-0s pattern in the OTUk overhead locations are adapted to the ODU1 clock via justification (asynchronous mapping). These adapted ODU0 signals are byte interleaved into the OPU1 payload area, and their justification control and opportunity signals (JC, NJO) are frame interleaved into the OPU1 overhead area and ODU1 overhead is added.
+
+![Diagram illustrating the multiplexing of two ODU0 signals into an ODU1 signal. The top part shows an ODU0 frame structure with Alignment, ODU0 OH, OPU0 OH, and Client layer signal. The middle part shows an ODU1 frame structure with ODU1 OH, OPU1 OH, and two tributary slots (TS1, TS2) each containing an ODU0 frame. The bottom part shows an ODU1 frame with ODU1 OH, OPU1 OH, and two tributary slots (TS1, TS2) with a gap between them. Dashed lines indicate the mapping of ODU0 frames into the ODU1 payload area.](8dd299498fe4924af215a1d179688e11_img.jpg)
+
+NOTE 1 – The ODU0 floats in 1/2 of the OPU1 payload area. An ODU0 frame will cross multiple ODU1 frame boundaries. A complete ODU0 frame (15296 bytes) requires the bandwidth of one TribSlot in (15296/7616) 2.008 ODU1 frames. This is not illustrated.
+
+NOTE 2 – The OPU1 OH contains 1 column of justification control and opportunity overhead for each of the 2 tributary slots in a 2-frame multiframe format. This is not illustrated.
+
+Diagram illustrating the multiplexing of two ODU0 signals into an ODU1 signal. The top part shows an ODU0 frame structure with Alignment, ODU0 OH, OPU0 OH, and Client layer signal. The middle part shows an ODU1 frame structure with ODU1 OH, OPU1 OH, and two tributary slots (TS1, TS2) each containing an ODU0 frame. The bottom part shows an ODU1 frame with ODU1 OH, OPU1 OH, and two tributary slots (TS1, TS2) with a gap between them. Dashed lines indicate the mapping of ODU0 frames into the ODU1 payload area.
+
+G.709-Y.1331(12)\_FIII.2
+
+**Figure III.2 – Example of multiplexing 2 ODU0 signals into an ODU1**
+
+## **Appendix IV**
+
+### **Blank appendix**
+
+*This appendix is intentionally left blank.*
+
+## Appendix V
+
+### ODUk multiplex structure identifier (MSI) examples
+
+(This appendix does not form an integral part of this Recommendation.)
+
+The following figures present four examples of ODU1 and ODU2 carriage within an OPU3 and the associated MSI encoding.
+
+|                | 1  | 2 | 3 | 4 | 5 | 6      | 7 | 8 |             |
+|----------------|----|---|---|---|---|--------|---|---|-------------|
+| <i>PSI[2]</i>  | 00 |   |   |   |   | 000000 |   |   | <i>TS1</i>  |
+| <i>PSI[3]</i>  | 00 |   |   |   |   | 000001 |   |   | <i>TS2</i>  |
+| <i>PSI[4]</i>  | 00 |   |   |   |   | 000010 |   |   | <i>TS3</i>  |
+| <i>PSI[5]</i>  | 00 |   |   |   |   | 000011 |   |   | <i>TS4</i>  |
+| <i>PSI[6]</i>  | 00 |   |   |   |   | 000100 |   |   | <i>TS5</i>  |
+| <i>PSI[7]</i>  | 00 |   |   |   |   | 000101 |   |   | <i>TS6</i>  |
+| <i>PSI[8]</i>  | 00 |   |   |   |   | 000110 |   |   | <i>TS7</i>  |
+| <i>PSI[9]</i>  | 00 |   |   |   |   | 000111 |   |   | <i>TS8</i>  |
+| <i>PSI[10]</i> | 00 |   |   |   |   | 001000 |   |   | <i>TS9</i>  |
+| <i>PSI[11]</i> | 00 |   |   |   |   | 001001 |   |   | <i>TS10</i> |
+| <i>PSI[12]</i> | 00 |   |   |   |   | 001010 |   |   | <i>TS11</i> |
+| <i>PSI[13]</i> | 00 |   |   |   |   | 001011 |   |   | <i>TS12</i> |
+| <i>PSI[14]</i> | 00 |   |   |   |   | 001100 |   |   | <i>TS13</i> |
+| <i>PSI[15]</i> | 00 |   |   |   |   | 001101 |   |   | <i>TS14</i> |
+| <i>PSI[16]</i> | 00 |   |   |   |   | 001110 |   |   | <i>TS15</i> |
+| <i>PSI[17]</i> | 00 |   |   |   |   | 001111 |   |   | <i>TS16</i> |
+
+Figure V.1 – OPU3-MSI coding for the case of 16 ODU1s into OPU3
+
+|         | 1  | 2 | 3 | 4 | 5      | 6 | 7 | 8 |      |
+|---------|----|---|---|---|--------|---|---|---|------|
+| PSI[2]  | 01 |   |   |   | 000000 |   |   |   | TS1  |
+| PSI[3]  | 01 |   |   |   | 000001 |   |   |   | TS2  |
+| PSI[4]  | 01 |   |   |   | 000010 |   |   |   | TS3  |
+| PSI[5]  | 01 |   |   |   | 000011 |   |   |   | TS4  |
+| PSI[6]  | 01 |   |   |   | 000000 |   |   |   | TS5  |
+| PSI[7]  | 01 |   |   |   | 000001 |   |   |   | TS6  |
+| PSI[8]  | 01 |   |   |   | 000010 |   |   |   | TS7  |
+| PSI[9]  | 01 |   |   |   | 000011 |   |   |   | TS8  |
+| PSI[10] | 01 |   |   |   | 000000 |   |   |   | TS9  |
+| PSI[11] | 01 |   |   |   | 000001 |   |   |   | TS10 |
+| PSI[12] | 01 |   |   |   | 000010 |   |   |   | TS11 |
+| PSI[13] | 01 |   |   |   | 000011 |   |   |   | TS12 |
+| PSI[14] | 01 |   |   |   | 000000 |   |   |   | TS13 |
+| PSI[15] | 01 |   |   |   | 000001 |   |   |   | TS14 |
+| PSI[16] | 01 |   |   |   | 000010 |   |   |   | TS15 |
+| PSI[17] | 01 |   |   |   | 000011 |   |   |   | TS16 |
+
+**Figure V.2 – OPU3-MSI coding for the case of 4 ODU2s into OPU3 TS#  
+(1, 5, 9, 13), (2, 6, 10, 14), (3, 7, 11, 15) and (4, 8, 12, 16)**
+
+|         | 1  | 2 | 3 | 4 | 5      | 6 | 7 | 8 |      |
+|---------|----|---|---|---|--------|---|---|---|------|
+| PSI[2]  | 01 |   |   |   | 000000 |   |   |   | TS1  |
+| PSI[3]  | 01 |   |   |   | 000001 |   |   |   | TS2  |
+| PSI[4]  | 01 |   |   |   | 000001 |   |   |   | TS3  |
+| PSI[5]  | 01 |   |   |   | 000010 |   |   |   | TS4  |
+| PSI[6]  | 01 |   |   |   | 000000 |   |   |   | TS5  |
+| PSI[7]  | 01 |   |   |   | 000011 |   |   |   | TS6  |
+| PSI[8]  | 01 |   |   |   | 000011 |   |   |   | TS7  |
+| PSI[9]  | 01 |   |   |   | 000011 |   |   |   | TS8  |
+| PSI[10] | 01 |   |   |   | 000000 |   |   |   | TS9  |
+| PSI[11] | 01 |   |   |   | 000000 |   |   |   | TS10 |
+| PSI[12] | 01 |   |   |   | 000001 |   |   |   | TS11 |
+| PSI[13] | 01 |   |   |   | 000001 |   |   |   | TS12 |
+| PSI[14] | 01 |   |   |   | 000011 |   |   |   | TS13 |
+| PSI[15] | 01 |   |   |   | 000010 |   |   |   | TS14 |
+| PSI[16] | 01 |   |   |   | 000010 |   |   |   | TS15 |
+| PSI[17] | 01 |   |   |   | 000010 |   |   |   | TS16 |
+
+**Figure V.3 – OPU3-MSI coding for the case of 4 ODU2s into OPU3 TS#  
+(1, 5, 9, 10), (2, 3, 11, 12), (4, 14, 15, 16) and (6, 7, 8, 13)**
+
+|                | 1  | 2 | 3 | 4 | 5 | 6      | 7 | 8 |             |
+|----------------|----|---|---|---|---|--------|---|---|-------------|
+| <i>PSI[2]</i>  | 01 |   |   |   |   | 000000 |   |   | <i>TS1</i>  |
+| <i>PSI[3]</i>  | 00 |   |   |   |   | 000001 |   |   | <i>TS2</i>  |
+| <i>PSI[4]</i>  | 00 |   |   |   |   | 000010 |   |   | <i>TS3</i>  |
+| <i>PSI[5]</i>  | 01 |   |   |   |   | 000001 |   |   | <i>TS4</i>  |
+| <i>PSI[6]</i>  | 01 |   |   |   |   | 000000 |   |   | <i>TS5</i>  |
+| <i>PSI[7]</i>  | 00 |   |   |   |   | 000101 |   |   | <i>TS6</i>  |
+| <i>PSI[8]</i>  | 00 |   |   |   |   | 000110 |   |   | <i>TS7</i>  |
+| <i>PSI[9]</i>  | 01 |   |   |   |   | 000001 |   |   | <i>TS8</i>  |
+| <i>PSI[10]</i> | 01 |   |   |   |   | 000000 |   |   | <i>TS9</i>  |
+| <i>PSI[11]</i> | 01 |   |   |   |   | 000001 |   |   | <i>TS10</i> |
+| <i>PSI[12]</i> | 00 |   |   |   |   | 001010 |   |   | <i>TS11</i> |
+| <i>PSI[13]</i> | 00 |   |   |   |   | 001011 |   |   | <i>TS12</i> |
+| <i>PSI[14]</i> | 01 |   |   |   |   | 000000 |   |   | <i>TS13</i> |
+| <i>PSI[15]</i> | 00 |   |   |   |   | 001101 |   |   | <i>TS14</i> |
+| <i>PSI[16]</i> | 00 |   |   |   |   | 001110 |   |   | <i>TS15</i> |
+| <i>PSI[17]</i> | 01 |   |   |   |   | 000001 |   |   | <i>TS16</i> |
+
+**Figure V.4 – OPU3-MSI coding for the case of 5 ODU1s and 2 ODU2s into OPU3 TS# (2), (6), (11), (12), (14), (1, 5, 9, 13) and (4, 8, 10, 16) and OPU3 TS# 3, 7, 15 unallocated (default to ODU1)**
+
+## Appendix VI
+
+### Parallel logic implementation of the CRC-9, CRC-8, CRC-5 and CRC-6
+
+(This appendix does not form an integral part of this Recommendation.)
+
+#### CRC-9
+
+Table VI.1 illustrates example logic equations for a parallel implementation of the CRC-9 using the  $g(x) = x^9 + x^3 + x^2 + 1$  polynomial over the  $\Sigma C_{ND}$  fields of JC1, JC2, JC4 and JC5. An "X" in a column of the table indicates that the message bit of that row is an input to the Exclusive-OR equation for calculating the CRC bit of that row. JC4.D1 corresponds to bit 2 of the JC4 mapping overhead octet, JC4.D2 corresponds to bit 3 of the JC4 octet, etc. (See Figure 20-7.) After computation, CRC bits crc1 to crc9 are inserted into the JC6 and JC3 octets with crc1 occupying bit 2 of the JC6 octet and crc9 occupying bit 2 of the JC3 octet.
+
+**Table VI.1 – Parallel logic equations for the CRC-9 implementation**
+
+| Mapping overhead bits | CRC checksum bits |      |      |      |      |      |      |      |      |
+|-----------------------|-------------------|------|------|------|------|------|------|------|------|
+|                       | crc1              | crc2 | crc3 | crc4 | crc5 | crc6 | crc7 | crc8 | crc9 |
+| JC4.D1                |                   | X    | X    |      |      | X    |      |      |      |
+| JC4.D2                |                   |      | X    | X    |      |      | X    |      |      |
+| JC4.D3                |                   |      |      | X    | X    |      |      | X    |      |
+| JC4.D4                |                   |      |      |      | X    | X    |      |      | X    |
+| JC4.D5                | X                 |      |      |      |      | X    |      | X    |      |
+| JC4.D6                |                   | X    |      |      |      |      | X    |      | X    |
+| JC4.D7                | X                 |      | X    |      |      |      | X    |      |      |
+| JC1.D8                |                   | X    |      | X    |      |      |      | X    |      |
+| JC1.D9                |                   |      | X    |      | X    |      |      |      | X    |
+| JC5.D10               | X                 |      |      | X    |      | X    | X    | X    |      |
+| JC5.D11               |                   | X    |      |      | X    |      | X    | X    | X    |
+| JC5.D12               | X                 |      | X    |      |      | X    | X    |      | X    |
+| JC5.D13               | X                 | X    |      | X    |      |      |      |      |      |
+| JC5.D14               |                   | X    | X    |      | X    |      |      |      |      |
+| JC5.D15               |                   |      | X    | X    |      | X    |      |      |      |
+| JC5.D16               |                   |      |      | X    | X    |      | X    |      |      |
+| JC2.D17               |                   |      |      |      | X    | X    |      | X    |      |
+| JC2.D18               |                   |      |      |      |      | X    | X    |      | X    |
+
+#### CRC-8
+
+Table VI.2 illustrates example logic equations for a parallel implementation of the CRC-8 using the  $g(x) = x^8 + x^3 + x^2 + 1$  polynomial over the JC1-JC2. An "X" in a column of the table indicates that the message bit of that row is an input to the Exclusive-OR equation for calculating the CRC bit of that row. JC1.C1 corresponds to the first bit (MSB) of the first mapping overhead octet (JC1), JC1.C2 corresponds to bit 2 of the first mapping overhead octet, etc. After computation, CRC bits crc1 to crc8 are inserted into the JC3 octet with crc1 occupying MSB and crc8 the LSB of the octet.
+
+**Table VI.2 – Parallel logic equations for the CRC-8 implementation**
+
+| Mapping overhead bits | CRC checksum bits |      |      |      |      |      |      |      |
+|-----------------------|-------------------|------|------|------|------|------|------|------|
+|                       | crc1              | crc2 | crc3 | crc4 | crc5 | crc6 | crc7 | crc8 |
+| JC1.C1                |                   | X    |      |      |      | X    |      | X    |
+| JC1.C2                | X                 |      | X    |      |      | X    |      |      |
+| JC1.C3                |                   | X    |      | X    |      |      | X    |      |
+| JC1.C4                |                   |      | X    |      | X    |      |      | X    |
+| JC1.C5                | X                 |      |      | X    |      |      | X    |      |
+| JC1.C6                |                   | X    |      |      | X    |      |      | X    |
+| JC1.C7                | X                 |      | X    |      |      |      | X    |      |
+| JC1.C8                |                   | X    |      | X    |      |      |      | X    |
+| JC2.C9                | X                 |      | X    |      | X    | X    | X    |      |
+| JC2.C10               |                   | X    |      | X    |      | X    | X    | X    |
+| JC2.C11               | X                 |      | X    |      | X    | X    |      | X    |
+| JC2.C12               | X                 | X    |      | X    |      |      |      |      |
+| JC2.C13               |                   | X    | X    |      | X    |      |      |      |
+| JC2.C14               |                   |      | X    | X    |      | X    |      |      |
+| JC2.II                |                   |      |      | X    | X    |      | X    |      |
+| JC2.DI                |                   |      |      |      | X    | X    |      | X    |
+
+**CRC-5**
+
+Table VI.3 illustrates example logic equations for a parallel implementation of the CRC-5 using the  $g(x) = x^5 + x + 1$  polynomial over the JC4-JC5 C<sub>n</sub>D fields. An "X" in a column of the table indicates that the message bit of that row is an input to the Exclusive-OR equation for calculating the CRC bit of that row. JC4.D1 corresponds to the first bit (MSB) of the first mapping overhead octet (JC1), JC4.D2 corresponds to bit 2 of the first mapping overhead octet, etc. After computation, CRC bits crc1 to crc5 are inserted into the JC6 octet with crc1 occupying JC6 bit 4 and crc5 the JC6 bit 8.
+
+**Table VI.3 – Parallel logic equations for the CRC-5 implementation**
+
+| Mapping overhead bits | CRC checksum bits |      |      |      |      |
+|-----------------------|-------------------|------|------|------|------|
+|                       | crc1              | crc2 | crc3 | crc4 | crc5 |
+| JC4.D1                | X                 |      | X    | X    |      |
+| JC4.D2                |                   | X    |      | X    | X    |
+| JC4.D3                | X                 |      | X    |      |      |
+| JC4.D4                |                   | X    |      | X    |      |
+| JC4.D5                |                   |      | X    |      | X    |
+| JC5.D6                | X                 |      |      | X    | X    |
+| JC5.D7                | X                 | X    |      |      |      |
+| JC5.D8                |                   | X    | X    |      |      |
+| JC5.D9                |                   |      | X    | X    |      |
+| JC5.D10               |                   |      |      | X    | X    |
+
+## CRC-6
+
+Table VI.4 illustrates example logic equations for a parallel implementation of the CRC-6 using the  $g(x) = x^6 + x^3 + x^2 + 1$  polynomial over the JC1-JC2. An "X" in a column of the table indicates that the message bit of that row is an input to the Exclusive-OR equation for calculating the CRC bit of that row. JC1.C1 corresponds to bit 3 of the first mapping overhead octet (JC1), JC1.C2 corresponds to bit 4 of the first mapping overhead octet, etc. After computation, CRC bits crc1 to crc6 are inserted into the JC3 octet with crc1 occupying bit 3 and crc6 the LSB of the octet. (See Figure 20-7)
+
+**Table VI.4 – Parallel logic equations for the CRC-6 implementation**
+
+| Mapping overhead bits | CRC checksum bits |      |      |      |      |      |
+|-----------------------|-------------------|------|------|------|------|------|
+|                       | crc1              | crc2 | crc3 | crc4 | crc5 | crc6 |
+| JC1.C1                |                   |      | X    |      | X    | X    |
+| JC1.C2                | X                 |      |      |      | X    | X    |
+| JC1.C3                | X                 | X    |      | X    | X    | X    |
+| JC1.C4                | X                 | X    | X    | X    |      | X    |
+| JC1.C5                | X                 | X    | X    |      |      |      |
+| JC1.C6                |                   | X    | X    | X    |      |      |
+| JC2.C7                |                   |      | X    | X    | X    |      |
+| JC2.C8                |                   |      |      | X    | X    | X    |
+| JC2.C9                | X                 |      |      | X    |      | X    |
+| JC2.C10               | X                 | X    |      | X    |      |      |
+| JC2.II                |                   | X    | X    |      | X    |      |
+| JC2.DI                |                   |      | X    | X    |      | X    |
+
+## **Appendix VII**
+
+### **OTL4.10 structure**
+
+(This appendix does not form an integral part of this Recommendation.)
+
+The information of this appendix is included in [b-ITU-T G-Sup.58].
+
+## **Appendix VIII**
+
+### **CPRI into ODU mapping**
+
+(This appendix does not form an integral part of this Recommendation.)
+
+The information of this appendix is included in [b-ITU-T G-Sup.56].
+
+## Appendix IX
+
+### Overview of CBR clients into OPU mapping types
+
+(This appendix does not form an integral part of this Recommendation.)
+
+As there are many different constant bit rate client signals and multiple mapping procedures, Table IX.1 provides an overview of the mapping procedure that is specified for each client.
+
+**Table IX.1 – Overview of CBR client into OPUk mapping types**
+
+|            | OPU0                           | OPU1                        | OPU2        | OPU2e                   | OPU3                            | OPU4                        | OPUflex |
+|------------|--------------------------------|-----------------------------|-------------|-------------------------|---------------------------------|-----------------------------|---------|
+| STM-1      | GMP<br>with C <sub>1D</sub>    | –                           | –           | –                       | –                               | –                           | –       |
+| STM-4      | GMP<br>with C <sub>1D</sub>    | –                           | –           | –                       | –                               | –                           | –       |
+| STM-16     | –                              | AMP,<br>BMP                 | –           | –                       | –                               | –                           | –       |
+| STM-64     | –                              | –                           | AMP,<br>BMP | –                       | –                               | –                           | –       |
+| STM-256    | –                              | –                           | –           | –                       | AMP,<br>BMP                     | –                           | –       |
+| 1000BASE-X | TTT+GM<br>P no C <sub>nD</sub> | –                           | –           | –                       | –                               | –                           | –       |
+| 10GBASE-R  | –                              | –                           | –           | 16FS+BMP                | –                               | –                           | –       |
+| 25GBASE-R  | –                              | –                           | –           | –                       | –                               | –                           | BMP     |
+| 40GBASE-R  | –                              | –                           | –           | –                       | TTT+GMP<br>with C <sub>8D</sub> | –                           | –       |
+| 50GBASE-R  | –                              | –                           | –           | –                       | –                               | –                           | BMP     |
+| 100GBASE-R | –                              | –                           | –           | –                       | –                               | GMP<br>with C <sub>8D</sub> | –       |
+| 200GBASE-R | –                              | –                           | –           | –                       | –                               | –                           | BMP     |
+| 400GBASE-R | –                              | –                           | –           | –                       | –                               | –                           | BMP     |
+| FC-100     | GMP<br>no C <sub>nD</sub>      | –                           | –           | –                       | –                               | –                           | –       |
+| FC-200     | –                              | GMP<br>with C <sub>8D</sub> | –           | –                       | –                               | –                           | –       |
+| FC-400     | –                              | –                           | –           | –                       | –                               | –                           | BMP     |
+| FC-800     | –                              | –                           | –           | –                       | –                               | –                           | BMP     |
+| FC-1200    | –                              | –                           | –           | TTT+16FS+<br>BMP (Note) | –                               | –                           | –       |
+| FC-1600    | –                              | –                           | –           | –                       | –                               | –                           | BMP     |
+| FC-3200    | –                              | –                           | –           | –                       | –                               | –                           | BMP     |
+| CM_GPON    | –                              | AMP                         | –           | –                       | –                               | –                           | –       |
+| CM_XGPON   | –                              | –                           | AMP         | –                       | –                               | –                           | –       |
+| IB SDR     | –                              | –                           | –           | –                       | –                               | –                           | BMP     |
+| IB DDR     | –                              | –                           | –           | –                       | –                               | –                           | BMP     |
+
+**Table IX.1 – Overview of CBR client into OPUk mapping types**
+
+|                                                                     | <b>OPU0</b>                | <b>OPU1</b>                | <b>OPU2</b> | <b>OPU2e</b> | <b>OPU3</b> | <b>OPU4</b> | <b>OPUflex</b> |
+|---------------------------------------------------------------------|----------------------------|----------------------------|-------------|--------------|-------------|-------------|----------------|
+| IB QDR                                                              | –                          | –                          | –           | –            | –           | –           | BMP            |
+| SBCON/ESCON                                                         | GMP<br>no C <sub>nD</sub>  | –                          | –           | –            | –           | –           | –              |
+| DVB_ASI                                                             | GMP<br>no C <sub>nD</sub>  | –                          | –           | –            | –           | –           | –              |
+| SDI                                                                 | GMP<br>TBD C <sub>nD</sub> | –                          | –           | –            | –           | –           | –              |
+| 1.5G SDI                                                            | –                          | GMP<br>TBD C <sub>nD</sub> | –           | –            | –           | –           | –              |
+| 3G SDI                                                              | –                          | –                          | –           | –            | –           | –           | BMP            |
+| FlexE Client                                                        | –                          | –                          | –           | –            | –           | –           | IMP            |
+| FlexE-aware                                                         | –                          | –                          | –           | –            | –           | –           | BGMP           |
+| NOTE – For this specific case the mapping used is byte synchronous. |                            |                            |             |              |             |             |                |
+
+## Appendix X
+
+### Overview of ODUj into OPUk mapping types
+
+(This appendix does not form an integral part of this Recommendation.)
+
+As there are many different ODUj bit rate signals and multiple mapping procedures, Table X.1 provides an overview of the mapping procedure that is specified for each ODUj.
+
+Table X.1 – Overview of ODUj client into OPUk mapping types
+
+|                      | 2.5G tributary slots     |                          | 1.25G tributary slots    |                            |                            |                            |                              |                             |
+|----------------------|--------------------------|--------------------------|--------------------------|----------------------------|----------------------------|----------------------------|------------------------------|-----------------------------|
+|                      | OPU2                     | OPU3                     | OPU1                     | OPU2                       | OPU3                       | OPU4                       | OPU25                        | OPU50                       |
+| ODU0                 | –                        | –                        | ODTU01<br>AMP<br>(PT=20) | ODTU2.1<br>GMP<br>(PT=21)  | ODTU3.1<br>GMP<br>(PT=21)  | ODTU4.1<br>GMP<br>(PT=21)  | ODTU25.1<br>GMP<br>(PT=21)   | ODTU50.1<br>GMP<br>(PT=21)  |
+| ODU1                 | ODTU12<br>AMP<br>(PT=20) | ODTU13<br>AMP<br>(PT=20) | –                        | ODTU12<br>AMP<br>(PT=21)   | ODTU13<br>AMP<br>(PT=21)   | ODTU4.2<br>GMP<br>(PT=21)  | ODTU25.2<br>GMP<br>(PT=21)   | ODTU50.2<br>GMP<br>(PT=21)  |
+| ODU2                 | –                        | ODTU23<br>AMP<br>(PT=20) | –                        | –                          | ODTU23<br>AMP<br>(PT=21)   | ODTU4.8<br>GMP<br>(PT=21)  | ODTU25.8<br>GMP<br>(PT=21)   | ODTU50.8<br>GMP<br>(PT=21)  |
+| ODU2e                | –                        | –                        | –                        | –                          | ODTU3.9<br>GMP<br>(PT=21)  | ODTU4.8<br>GMP<br>(PT=21)  | ODTU25.8<br>GMP<br>(PT=21)   | ODTU50.8<br>GMP<br>(PT=21)  |
+| ODU3                 | –                        | –                        | –                        | –                          | –                          | ODTU4.31<br>GMP<br>(PT=21) | –                            | ODTU50.31<br>GMP<br>(PT=21) |
+| ODUflex              | –                        | –                        | –                        | ODTU2.ts<br>GMP<br>(PT=21) | ODTU3.ts<br>GMP<br>(PT=21) | ODTU4.ts<br>GMP<br>(PT=21) | ODTU25.ts<br>GMP<br>(PT=21)  | ODTU50.ts<br>GMP<br>(PT=21) |
+| ODUflex(IB<br>SDR)   | –                        | –                        | –                        | ODTU2.3<br>GMP<br>(PT=21)  | ODTU3.3<br>GMP<br>(PT=21)  | ODTU4.2<br>GMP<br>(PT=21)  | ODTU25.2<br>GMP<br>(PT=21)   | ODTU50.2<br>GMP<br>(PT=21)  |
+| ODUflex(IB<br>DDR)   | –                        | –                        | –                        | ODTU2.5<br>GMP<br>(PT=21)  | ODTU3.5<br>GMP<br>(PT=21)  | ODTU4.4<br>GMP<br>(PT=21)  | ODTU25.4<br>GMP<br>(PT=21)   | ODTU50.4<br>GMP<br>(PT=21)  |
+| ODUflex(IB<br>QDR)   | –                        | –                        | –                        | –                          | ODTU3.9<br>GMP<br>(PT=21)  | ODTU4.8<br>GMP<br>(PT=21)  | ODTU25.8<br>GMP<br>(PT=21)   | ODTU50.8<br>GMP<br>(PT=21)  |
+| ODUflex(FC-<br>400)  | –                        | –                        | –                        | ODTU2.4<br>GMP<br>(PT=21)  | ODTU3.4<br>GMP<br>(PT=21)  | ODTU4.4<br>GMP<br>(PT=21)  | ODTU25.4<br>GMP<br>(PT=21)   | ODTU50.4<br>GMP<br>(PT=21)  |
+| ODUflex(FC-<br>800)  | –                        | –                        | –                        | ODTU2.7<br>GMP<br>(PT=21)  | ODTU3.7<br>GMP<br>(PT=21)  | ODTU4.7<br>GMP<br>(PT=21)  | ODTU25.7<br>GMP<br>(PT=21)   | ODTU50.7<br>GMP<br>(PT=21)  |
+| ODUflex(FC-<br>1600) | –                        | –                        | –                        | –                          | ODTU3.12<br>GMP<br>(PT=21) | ODTU4.11<br>GMP<br>(PT=21) | ODTU25.1<br>1 GMP<br>(PT=21) | ODTU50.11<br>GMP<br>(PT=21) |
+| ODUflex(FC-<br>3200) | –                        | –                        | –                        | –                          | ODTU3.23<br>GMP<br>(PT=21) | ODTU4.22<br>GMP<br>(PT=21) | –                            | ODTU50.22<br>GMP<br>(PT=21) |
+
+Table X.1 – Overview of ODUj client into OPUk mapping types
+
+|                                         | 2.5G tributary slots |      | 1.25G tributary slots |                              |                              |                              |                                   |                               |
+|-----------------------------------------|----------------------|------|-----------------------|------------------------------|------------------------------|------------------------------|-----------------------------------|-------------------------------|
+|                                         | OPU2                 | OPU3 | OPU1                  | OPU2                         | OPU3                         | OPU4                         | OPU25                             | OPU50                         |
+| ODUflex(25G BASE-R)                     | –                    | –    | –                     | –                            | ODTU3.21<br>GMP<br>(PT=21)   | ODTU4.20<br>GMP<br>(PT=21)   | ODTU25.2<br>0 GMP<br>(PT=21)      | ODTU50.20<br>GMP<br>(PT=21)   |
+| ODUflex(50G BASE-R)                     | –                    | –    | –                     | –                            | –                            | ODTU4.40<br>GMP<br>(PT=21)   | –                                 | ODTU50.40<br>GMP<br>(PT=21)   |
+| ODUflex(GFP )                           | –                    | –    | –                     | ODTU2.ts<br>(GMP)<br>(PT=21) | ODTU3.ts<br>(GMP)<br>(PT=21) | ODTU4.ts<br>(GMP)<br>(PT=21) | ODTU25.ts<br>(GMP)<br>(PT=21)     | ODTU50.ts<br>(GMP)<br>(PT=21) |
+| ODUflex(GFP ,n,2), n=1, ... ,8 (ts=n)   | –                    | –    | –                     | ODTU2.ts<br>(GMP)<br>(PT=21) | ODTU3.ts<br>(GMP)<br>(PT=21) | ODTU4.ts<br>(GMP)<br>(PT=21) | ODTU25.ts<br>(GMP)<br>(PT=21)     | ODTU50.ts<br>(GMP)<br>(PT=21) |
+| ODUflex(GFP ,n,3), n=9, ... ,20 (ts=n)  | –                    | –    | –                     | –                            | ODTU3.ts<br>(GMP)<br>(PT=21) | ODTU4.ts<br>(GMP)<br>(PT=21) | ODTU25.ts<br>(GMP)<br>(PT=21)     | ODTU50.ts<br>(GMP)<br>(PT=21) |
+| ODUflex(GFP ,n,3), n=21, ... ,32 (ts=n) | –                    | –    | –                     | –                            | ODTU3.ts<br>(GMP)<br>(PT=21) | ODTU4.ts<br>(GMP)<br>(PT=21) | –                                 | ODTU50.ts<br>(GMP)<br>(PT=21) |
+| ODUflex(GFP ), n=33, ... ,40 (ts=n)     | –                    | –    | –                     | –                            | –                            | ODTU4.ts<br>(GMP)<br>(PT=21) | –                                 | ODTU50.ts<br>(GMP)<br>(PT=21) |
+| ODUflex(GFP ,n,4), n=41, ... ,80 (ts=n) | –                    | –    | –                     | –                            | –                            | ODTU4.ts<br>(GMP)<br>(PT=21) | –                                 | –                             |
+| ODUflex(IMP )                           | –                    | –    | –                     | ODTU2.ts<br>(GMP)<br>(PT=21) | ODTU3.ts<br>(GMP)<br>(PT=21) | ODTU4.ts<br>(GMP)<br>(PT=21) | ODTU25.ts<br>(GMP)<br>(PT=21)     | ODTU50.ts<br>(GMP)<br>(PT=21) |
+| ODUflex(IMP, s), s=2                    | –                    | –    | –                     | –                            | ODTU3.9<br>(GMP)<br>(PT=21)  | ODTU4.8<br>(GMP)<br>(PT=21)  | ODTU25.8<br>(GMP)<br>(PT=21)      | ODTU50.8<br>(GMP)<br>(PT=21)  |
+| ODUflex(IMP, s), s=5                    | –                    | –    | –                     | –                            | ODTU3.21<br>(GMP)<br>(PT=21) | ODTU4.20<br>(GMP)<br>(PT=21) | ODTU25.2<br>0<br>(GMP)<br>(PT=21) | ODTU50.20<br>(GMP)<br>(PT=21) |
+| ODUflex(IMP, s), s=8                    | –                    | –    | –                     | –                            | –                            | ODTU4.32<br>(GMP)<br>(PT=21) | –                                 | ODTU50.32<br>(GMP)<br>(PT=21) |
+| ODUflex(IMP, s), s=10                   | –                    | –    | –                     | –                            | –                            | ODTU4.40<br>(GMP)<br>(PT=21) | –                                 | ODTU50.40<br>(GMP)<br>(PT=21) |
+| ODUflex(IMP, s), s=15,20 (ts=4×s)       | –                    | –    | –                     | –                            | –                            | ODTU4.ts<br>(GMP)<br>(PT=21) | –                                 | –                             |
+
+## Appendix XI
+
+### Derivation of recommended ODUflex(GFP) bit-rates based on $n \times \text{ODUk.ts}$ clock and examples of ODUflex(GFP,n,k) clock generation
+
+(This appendix does not form an integral part of this Recommendation.)
+
+#### XI.1 Introduction
+
+The recommended bit-rates for ODUflex(GFP,n,k) are provided in Table 7-8. While in principle an ODUflex(GFP) may be of any bit-rate, there were at the time of the introduction of the ODUflex a variety of reasons for recommending particular rates for the ODUflex(GFP,n,k):
+
+- To encourage a common set of bit-rates which can be expected to be supported by multiple manufacturers.
+- To provide the largest amount of bandwidth possible within a given amount of resource (number of tributary slots) independent of the ODUk over which the ODUflex(GFP,n,k) may be routed.
+- To maintain the number of tributary slots required if the ODUflex(GFP,n,k) must be rerouted, e.g., during a restoration.
+- To satisfy a protocol requirement for ODUflex hitless resizing that a resizable ODUflex(GFP,n,k) must occupy the same number of tributary slots on every ODUk path over which it is carried, and that a resize operation must always add or remove at least one tributary slot.
+
+#### XI.2 Tributary slot sizes
+
+ODUflex(GFP,n,k) is mapped via GMP into a certain number of 1.25G tributary slots of a HO OPU2, OPU3, or OPU4. Each of these have different tributary slot sizes:
+
+$$OPU2\_TS = \frac{238}{237} \times 4 \times STM16 \times \frac{476 \text{ columns}}{3808 \text{ columns}} = 1249409.620 \text{ kbit/s} \pm 20\text{ppm}$$
+
+$$OPU3\_TS = \frac{238}{236} \times 16 \times STM16 \times \frac{119 \text{ columns}}{3808 \text{ columns}} = 1254703.729 \text{ kbit/s} \pm 20\text{ppm}$$
+
+$$OPU4\_TS = \frac{238}{227} \times 40 \times STM16 \times \frac{47.5 \text{ columns}}{3808 \text{ columns}} = 1301709.251 \text{ kbit/s} \pm 20\text{ppm}$$
+
+An ODUflex(GFP,n,2) that occupies 8 or fewer tributary slots may be routed over OPU2, OPU3, or OPU4. The smallest tributary slot that may be encountered along the route of the ODUflex(GFP,n,2) is that of OPU2. Even if the initially selected route does not choose a link of OPU2, the ODUflex(GFP,n,2) should be sized to a multiple of the OPU2 tributary slot size to preserve the possibility to restore the ODUflex(GFP,n,2) over a route that includes OPU2 without changing the size of the ODUflex or the number of tributary slots it occupies.
+
+An ODUflex(GFP,n,3) that occupies at least 9, but no more than 32 tributary slots may be routed over OPU3 or OPU4. It does not fit over OPU2. Therefore such an ODUflex(GFP,n,3) may be sized to a multiple of the OPU3 tributary slot size. Even if the initially selected route does not choose a link of OPU3, the ODUflex(GFP,n,3) should be sized to a multiple of the OPU3 tributary slot size to preserve the possibility to restore the ODUflex(GFP,n,3) over a route that includes OPU3 without changing the size of the ODUflex or the number of tributary slots it occupies.
+
+An ODUflex(GFP,n,4) that occupies at least 33, but no more than 80 tributary slots may only be carried via OPU4, and may therefore take advantage of the full size of the OPU4 tributary slot size.
+
+A small margin must be left between the ODUflex(GFP,n,k) size and the integral multiple of the tributary slot size to accommodate possible clock variation along a sequence of OPUk links without overflowing the range of  $C_m$  in the GMP mapper.
+
+Physical layers for data interfaces such as Ethernet and Fibre Channel have historically used a clock tolerance of  $\pm 100$  ppm. This range is sufficiently wide that specifying this as the clock tolerance for ODUPflex(GFP,n,k) can accommodate a variety of mechanisms for generating an ODUPflex(GFP,n,k) clock and remain within the clock tolerance range.
+
+ODUk.ts as shown in Table 7-8 is an increment of bandwidth, which, when multiplied by a number of 1.25G tributary slots, gives the recommended size of an ODUPflex(GFP,n,k) optimized to occupy a given number of tributary slots of a server OPUk. These values are chosen to allow sufficient margin that allows the OPUk and the ODUPflex(GFP,n,k) to independently vary over their full clock tolerance range without exceeding the capacity of the allocated tributary slots.
+
+The nominal values for ODUk.ts are chosen to be 186 ppm below the bandwidth of a single 1.25G tributary slot of a server OPUk. This allows the ODUPflex(GFP,n,k) clock to be as much as 100 ppm above its nominal rate and the server OPUk to be as much as 20 ppm below its nominal clock rate, allowing approximately 66 ppm of margin to accommodate jitter and to ensure that the largest average  $C_m$  value even in the worst-case situation of the OPUk at -20 ppm from its nominal value and the ODUPflex(GFP,n,k) at +100 ppm from its nominal value will be one less than the maximum value (i.e., the maximum average  $C_m$  is no more than 15231 out of 15232 for ODUPflex(GFP,n,k) carried over OPU2 or OPU3, and no more than 15199 out of 15200 for ODUPflex(GFP,n,k) carried over OPU4).
+
+**Table XI.1 – Generation of ODUflex(GFP,n,k) clock from server OPUk clock using fixed  $C_m$**
+
+| OPUk | Nominal payload bit rate | Nominal 1.25G TS bit rate | ODU2.ts      |                 |              |                 |              |                 |
+|------|--------------------------|---------------------------|--------------|-----------------|--------------|-----------------|--------------|-----------------|
+|      |                          |                           | $C_m$ out of | Bit-rate per TS |              |                 |              |                 |
+| OPU2 | 9'995'276.962            | 1'249'409.620             | 15230        | 1'249'245.570   | ODU3.ts      |                 |              |                 |
+|      |                          |                           | 15232        |                 |              |                 |              |                 |
+| OPU3 | 40'150'519.322           | 1'254'703.729             | +20 ppm      | 1'249'270.555   | $C_m$ out of | Bit-rate per TS |              |                 |
+|      |                          |                           | -20 ppm      | 1'249'220.585   |              |                 |              |                 |
+|      |                          |                           | 15165        | 1'249'184.746   | 15230        | 1'254'538.983   | ODU4.ts      |                 |
+|      |                          |                           | 15232        |                 | 15232        |                 |              |                 |
+| OPU4 | 104'355'975.330          | 1'301'709.251             | +20 ppm      | 1'249'209.729   |              | 1'254'564.074   | $C_m$ out of | Bit-rate per TS |
+|      |                          |                           | -20 ppm      | 1'249'159.762   |              | 1'254'513.892   |              |                 |
+|      |                          |                           | 14587        | 1'249'212.687   | 14649        | 1'254'522.291   | 15198        | 1'301'537.974   |
+|      |                          |                           | 15200        |                 | 15200        |                 | 15200        |                 |
+|      |                          |                           | +20 ppm      | 1'249'237.671   |              | 1'254'547.381   |              | 1'301'564.004   |
+|      |                          |                           | -20 ppm      | 1'249'187.703   |              | 1'254'497.200   |              | 1'301'511.943   |
+|      |                          | ODUk.ts                   | nominal      | 1'249'177.230   |              | 1'254'470.354   |              | 1'301'467.133   |
+|      |                          |                           | +100 ppm     | 1'249'302.148   |              | 1'254'595.801   |              | 1'301'597.280   |
+|      |                          |                           | -100 ppm     | 1'249'052.312   |              | 1'254'344.907   |              | 1'301'336.986   |
+
+### XI.3 Example methods for ODUflex(GFP,n,k) clock generation
+
+#### XI.3.1 Generating ODUflex(GFP,n,k) clock from OPUk clock
+
+The clock for an ODUflex(GFP,n,k) may be generated from the initial server OPUk over which the ODUflex(GFP,n,k) is carried by setting the value of  $C_m$  to a fixed value on the initial segment. Normal GMP processing on subsequent segments avoids the need to couple the server OPUk clocks along the path.
+
+Table XI-1 illustrates how a clock for an ODUflex(GFP,n,k) occupying  $n \times$  ODUk.ts can be derived from the server OPUk clock using a fixed value of  $C_m$  in the initial segment of the path.
+
+For example, for an ODUflex(GFP,n,k) occupying up to 8 tributary slots should be based on ODU2.ts, and therefore have a clock frequency of  $n \times 1'249'177.230$  kbit/s  $\pm 100$  ppm. This allows the ODUflex(GFP,n,k) to have a frequency of between  $n \times 1'249'052.312$  kbit/s and  $n \times 1'249'302.148$  kbit/s.
+
+- If the initial segment over which the ODUflex(GFP,n,k) is carried is an OPU2, a clock in this range can be generated by fixing the value of  $C_m$  on the initial segment to 15230, which will result in the ODUflex having a clock of  $n \times 1'249'245.570$  kbit/s  $\pm 20$  ppm. While the center frequency of this range differs from the nominal value of ODU2.ts, the clock tolerance is narrower, being locked to the OPU2, so the possible clock range is fully within the  $\pm 100$  ppm range allowed.
+- If the initial segment is an OPU3, the ODUflex(GFP,n,k) of a multiple of ODU2.ts can be generated using a fixed value of  $C_m=15165$  on the initial ODU3 segment, which will result in the ODUflex having a clock of  $n \times 1'249'184.746$  kbit/s  $\pm 20$  ppm,
+- If the initial segment is an OPU4, the ODUflex(GFP,n,k) of a multiple of ODU2.ts can be generated using a fixed value of  $C_m=14587$  on the initial OPU4 segment, which will result in the ODUflex having a clock of  $n \times 1'249'212.687$  kbit/s  $\pm 20$  ppm.
+
+The center frequencies of all of these ODUflex(GFP,n,k) are slightly different, but the resulting ranges for the clocks all fall within the  $\pm 100$  ppm window (see Figure XI.1). Fixed  $C_m$  for generating ODU3.ts and ODU4.ts from the initial OPUk can similarly be found from this table.
+
+![Figure XI.1 – Graphical representation of frequency ranges in Table XI.1. The figure consists of three horizontal frequency scales. The top scale shows the ODU2.ts range from 1'249'000 to 1'249'400, with a nominal center at 1'249'177.230. It highlights the OPU4 CK, OPU3 CK, and OPU2 CK ranges, and the ODU2.ts range from 1'249'052.312 to 1'249'302.148. The middle scale shows the ODU3.ts range from 1'254'300 to 1'254'700, with a nominal center at 1'254'500. It highlights the OPU4 CK and OPU3 CK ranges, and the ODU3.ts range from 1'254'344.907 to 1'254'595.801. The bottom scale shows the ODU4.ts range from 1'301'300 to 1'301'700, with a nominal center at 1'301'500. It highlights the OPU4 CK range, and the ODU4.ts range from 1'301'336.986 to 1'301'597.280. All scales include tick marks at 100-unit intervals and are labeled with 'nominal' at their centers.](47be3073a8fa63f06708058a046ad013_img.jpg)
+
+Figure XI.1 – Graphical representation of frequency ranges in Table XI.1. The figure consists of three horizontal frequency scales. The top scale shows the ODU2.ts range from 1'249'000 to 1'249'400, with a nominal center at 1'249'177.230. It highlights the OPU4 CK, OPU3 CK, and OPU2 CK ranges, and the ODU2.ts range from 1'249'052.312 to 1'249'302.148. The middle scale shows the ODU3.ts range from 1'254'300 to 1'254'700, with a nominal center at 1'254'500. It highlights the OPU4 CK and OPU3 CK ranges, and the ODU3.ts range from 1'254'344.907 to 1'254'595.801. The bottom scale shows the ODU4.ts range from 1'301'300 to 1'301'700, with a nominal center at 1'301'500. It highlights the OPU4 CK range, and the ODU4.ts range from 1'301'336.986 to 1'301'597.280. All scales include tick marks at 100-unit intervals and are labeled with 'nominal' at their centers.
+
+Figure XI.1 – Graphical representation of frequency ranges in Table XI.1
+
+### **XI.3.2 Generating ODUflex(GFP,n,k) clock from system clock**
+
+The clock for an ODUflex(GFP,n,k) may be generated using a multiplier from the internal system clock. Normally the internal system clock will have an accuracy of at least  $\pm 20$  ppm, perhaps even  $\pm 4.6$  ppm for a network element that supports both SDH and OTN interfaces. The exact multiplier to be used is implementation specific, and be chosen so that the range of the generated clock falls within the specified  $\pm 100$  ppm window around the nominal value of  $n \times \text{ODUk.ts}$ . Refer to Appendix XV for further information.
+
+## Appendix XII
+
+### Terminology changes between ITU-T G.709 Edition 4, Edition 5 and Edition 6
+
+(This appendix does not form an integral part of this Recommendation.)
+
+In Edition 5 of this Recommendation a number of terms used in Editions 1 to 4 have been modified. In Edition 6 of this Recommendation a number of terms used in Edition 5 have been modified. Table XII.1 provides the mapping between these terms in Editions 1 to 4, Edition 5, and Edition 6.
+
+**Table XII.1 – Terminology mapping**
+
+| ITU-T G.709 Edition 1 to 4                                | ITU-T G.709 Edition 5                     | ITU-T G.709 Edition 6                     |
+|-----------------------------------------------------------|-------------------------------------------|-------------------------------------------|
+| OTM-0.m                                                   | SOTU                                      | OTN point-to-point interface, type I      |
+| OTM-0.mvn                                                 | (multi-lane) SOTU                         | OTN point-to-point interface, type I      |
+| OTM-nr.m                                                  | MOTU                                      | OTN point-to-point interface, type II     |
+| OTM-1.m                                                   | SOTUm                                     | OTN optical networking interface, type II |
+| OTM-n.m                                                   | MOTUm                                     | OTN optical networking interface, type I  |
+| Optical Channel (OCh)                                     | OCh                                       | OCh                                       |
+| Optical Channel with reduced functionality (OChr)         | OCh-P                                     | OTSiG                                     |
+| Optical Channel Payload (OCh-P)                           | OCh-P                                     | OTSiG                                     |
+| Optical Channel Overhead (OCh-OH)                         | OCh-O                                     | OCh-O                                     |
+| Optical channel Transport Unit (OTU)                      | Optical Transport Unit (OTU)              | Optical Transport Unit (OTU)              |
+| Optical channel Data Unit (ODU)                           | Optical Data Unit (ODU)                   | Optical Data Unit (ODU)                   |
+| Optical channel Payload Unit (OPU)                        | Optical Payload Unit (OPU)                | Optical Payload Unit (OPU)                |
+| Optical channel Data Tributary Unit (ODTU)                | Optical Data Tributary Unit (ODTU)        | Optical Data Tributary Unit (ODTU)        |
+| Optical channel Data Tributary Unit Group (ODTUG)         | Optical Data Tributary Unit Group (ODTUG) | Optical Data Tributary Unit Group (ODTUG) |
+| Optical Multiplex Unit (OMU)                              | –                                         | –                                         |
+| Optical Channel Carrier (OCC)                             | –                                         | –                                         |
+| Optical Channel Carrier – overhead (OCCo)                 | –                                         | –                                         |
+| Optical Channel Carrier – payload (OCCp)                  | –                                         | –                                         |
+| Optical Channel Carrier with reduced functionality (OCCr) | –                                         | –                                         |
+| Optical Carrier Group (OCG)                               | –                                         | –                                         |
+| Optical Carrier Group with reduced functionality (OCGr)   | –                                         | –                                         |
+| Optical Carrier Group of order n (OCG)                    | –                                         | –                                         |
+
+**Table XII.1 – Terminology mapping**
+
+| ITU-T G.709 Edition 1 to 4                   | ITU-T G.709 Edition 5             | ITU-T G.709 Edition 6             |
+|----------------------------------------------|-----------------------------------|-----------------------------------|
+| OTM Overhead Signal (OOS)                    | Optical Supervisory Channel (OSC) | Optical Supervisory Channel (OSC) |
+| Optical Transport Lane (OTLk.n)              | OTLk.n lane                       | OTLk.n lane                       |
+| Optical Transport Lane Carrier Group (OTLCG) | –                                 | –                                 |
+| Optical Transport Lane Carrier (OTLC)        | –                                 | –                                 |
+| OPS0                                         | OPS                               | –                                 |
+| OPSn                                         | OPS                               | –                                 |
+| OPSMnk                                       | OPS                               | –                                 |
+| OTS-OH                                       | OTS-O                             | OTS-O                             |
+| OMS-OH                                       | OMS-O                             | OMS-O                             |
+| ODUflex(GFP)                                 | ODUflex(GFP)                      | ODUflex(GFP,n,k)                  |
+| –                                            | ODUflex(IMP)                      | ODUflex(IMP,s)                    |
+
+In Edition 5.0 of this Recommendation the following new terms are introduced:
+
+**Table XII.2 – New terms in Edition 5**
+
+|                                                     |
+|-----------------------------------------------------|
+| Optical Tributary Signal (OTSi)                     |
+| Optical Tributary Signal Group (OTSiG)              |
+| Optical Tributary Signal Group – Overhead (OTSiG-O) |
+| Optical Tributary Signal Assembly (OTSiA)           |
+
+The relationship between these new terms in and the OCh, OChr, OPS0, OPSn and OPSM terms is as follows:
+
+**Table XII.3 – Relationship between OCh, OChr, OPS0, OPSn, OPSM and OTSi terminology**
+
+|        |                                                                                                                                            |
+|--------|--------------------------------------------------------------------------------------------------------------------------------------------|
+| OCh-P  | OTSiG with one or more OTSi                                                                                                                |
+| OCh-O  | Reduced version of OTSiG-O:<br>– FDI-P, FDI-O and OCI: supported<br>– TTI, BDI-P, BDI-O, TSI: not supported                                |
+| OCh    | Reduced version of OTSiA:<br>– OTSiG with one or more OTSi<br>– FDI-P, FDI-O and OCI: supported<br>– TTI, BDI-P, BDI-O, TSI: not supported |
+| OChr   | OTSiG with one OTSi; no OTSiG-O                                                                                                            |
+| OPS0   | OTSiG with one OTSi; no OTSiG-O                                                                                                            |
+| OPSMnk | OTSiG with m OTSi; no OTSiG-O                                                                                                              |
+| OPSn   | n OTSiG and no OTSiG-O; each OTSiG with one OTSi                                                                                           |
+
+## Appendix XIII
+
+### OTUCn sub rates (OTUCn-M) Applications
+
+(This appendix does not form an integral part of this Recommendation.)
+
+#### XIII.1 Introduction
+
+This appendix describes OTUCn-M application scenarios for the OTUCn-M signal defined in Annex H. It is assumed that the OTUCn-M processing is performed in the PHY module so that the interface between the module and framer (MFI) is not changed.
+
+Figures XIII.1 and XIII.2 illustrate two scenarios for subrating applications. The first scenario deploys subrating between two line ports connecting two ODU cross connects (XC). The second scenario deploys subrating between transponders which are in a different domain B, which are separated from the ODU XCs in domain A and/or C. In this case the OTUCn between domain B and domain A or C continue in domain B as OTUCn-M.
+
+![Figure XIII.1: OTUCn sub rate application scenario A](928773233290b815ec292945af49f31f_img.jpg)
+
+Diagram illustrating OTUCn sub rate application scenario A. Two Optical transport network A clouds are connected via a central line port. Each cloud contains an OTN XC (Optical Transport Network Cross Connect) connected to the line port. The signal flow is shown by horizontal arrows. Below the diagram, three nested horizontal lines represent the signal hierarchy: the outermost line is labeled 'ODUk/flex services', the middle line is labeled 'ODUCn', and the innermost line is labeled 'OTUCn-M'. The reference code G.709-Y.1331(16)\_FXIII.1 is shown at the bottom right.
+
+Figure XIII.1: OTUCn sub rate application scenario A
+
+Figure XIII.1 – OTUCn sub rate application scenario A
+
+![Figure XIII.2: OTUCn sub rate application scenario B](996e39b914f33cf1046ab1540d61973a_img.jpg)
+
+Diagram illustrating OTUCn sub rate application scenario B. Three Optical transport network clouds are shown: Optical transport network A, Optical transport network B, and Optical transport network A or C. Optical transport network A is connected to Optical transport network B via an OTN XC (Optical Transport Network Cross Connect). Optical transport network B contains two Transponder units connected in series. Optical transport network B is connected to Optical transport network A or C via another Transponder unit. The signal flow is shown by horizontal arrows. Below the diagram, three nested horizontal lines represent the signal hierarchy: the outermost line is labeled 'ODUk/flex services', the middle line is labeled 'ODUCn', and the innermost line is labeled 'OTUCn-M'. The innermost line is further divided into three segments: 'OTUCn', 'OTUCn-M', and 'OTUCn'. The reference code G.709-Y.1331(20)\_FXIII.2 is shown at the bottom right.
+
+Figure XIII.2: OTUCn sub rate application scenario B
+
+Figure XIII.2 – OTUCn sub rate application scenario B
+
+#### XIII.2 OTUCn-M frame format and rates
+
+As defined in Annex H, the OTUCn-M frame is a type of OTUCn frame which contains n instances of OTUC, ODUC and OPUC overhead and M 5 Gbit/s OPUCn tributary slots. If a particular value of M is not indicated, the frame contains 20\*n tributary slots.
+
+The use of this notation is illustrated below:
+
+- OTUC2-25: a 125 Gbit/s OTU signal with 25 (5 Gbit/s) tributary slots and 2 instances of OxUC overhead
+- OTUC2-30: a 150 Gbit/s OTU signal with 30 (5 Gbit/s) tributary slots and 2 instances of OxUC overhead
+- OTUC2: a 200 Gbit/s OTU signal with 40 (5 Gbit/s) tributary slots and 2 instances of OxUC overhead
+- OTUC3-50: a 250 Gbit/s OTU signal with 50 (5 Gbit/s) tributary slots and 3 instances of OxUC overhead
+
+The bit rate of an OTUCn-M signal is  $(10n + 119 * M) / (10n + 119 * 20 * n) * \text{OTUCn bit rate}$ . The choice of which TS are assigned to each of the OTUC instances, and hence the signal rate of that OTUC instance, is vendor or application specific.
+
+### XIII.3 OTUCn-M fault condition
+
+For the case where subrating is used between transponders the following checks should be made.
+
+In the transmit (source) direction, transponder X should verify that the OPU tributary slots with the Availability bit of their OPUCn MSI overhead set to "available" are carried transparently by the OTUCn-M. For the case where one or more availability bits for the the tributary slots that are not carried transparently are set to "available", an OTUCn-AIS should be inserted by Transponder X.
+
+In the receive (sink) direction, transponder Y should check for a mismatch between received and expected OTUCn-M. If such a mismatch is detected an OTUCn-AIS should be inserted by Transponder Y.
+
+![Diagram illustrating the OTUCn sub rate mismatch fault condition. It shows a sequence of components: an OTN XC (represented by a cloud with a router icon) connected to Transponder X, which is connected to Transponder Y, which is connected to another OTN XC. Red arrows labeled 'OTUCn-AIS' indicate the insertion of alarms: one from Transponder X to the final OTN XC, and another from Transponder Y to the final OTN XC.](b3bf81a327421e28bc8471691b77b252_img.jpg)
+
+Diagram illustrating the OTUCn sub rate mismatch fault condition. It shows a sequence of components: an OTN XC (represented by a cloud with a router icon) connected to Transponder X, which is connected to Transponder Y, which is connected to another OTN XC. Red arrows labeled 'OTUCn-AIS' indicate the insertion of alarms: one from Transponder X to the final OTN XC, and another from Transponder Y to the final OTN XC.
+
+G.709-Y.1331(16)\_FXIII.3
+
+**Figure XIII.3 – OTUCn sub rate mismatch fault condition**
+
+## Appendix XIV
+
+### **Examples of interconnection of Ethernet UNI and FlexE Group UNI in two administrative domains in the OTN for the case that these UNIs deploy different mapping methods**
+
+(This appendix does not form an integral part of this Recommendation.)
+
+This appendix describes two cases to support the interconnection of an Ethernet UNI and a FlexE Group UNI in two administrative domains in the OTN, in which interconnection requires that the mapping method in one administrative domain is converted into the mapping method used in the other administrative domain.
+
+Case I is to perform the mapping method conversion at the FlexE group UNI-N port as shown in Figure XIV.1.
+
+Case II is to perform the mapping method conversion at an intermediate node along the connection as shown in Figure XIV.2.
+
+These conversion approaches provide for backward compatibility with Ethernet UNI-N ports designed prior to the definition of FlexE.
+
+Figure XIV.1 illustrates an implementation of case I. For the case of an Ethernet PCS encoded client service, the FlexE Group UNI-N port converts the FlexE Client signal into the corresponding Ethernet PCS encoded signal and maps it into an ODUk using BMP, TTT+GMP or GMP as specified in clause 17. The ODUk is transported through the OTN and is terminated in the Ethernet UNI-N port.
+
+For the case of an Ethernet MAC client service with a bit rate up to and including 100 Gbit/s, the FlexE Group UNI-N port terminates the FlexE Client signal, extracts the Ethernet MAC frames stream and maps this MAC frames stream into an ODUk using GFP-F as specified in clause 17. The ODUk is transported through the OTN and is terminated in the Ethernet UNI-N port.
+
+![Figure XIV.1: Ethernet PCS encoded or MAC signal interconnection between an Ethernet UNI and a FlexE UNI in case I. The diagram shows two OTN administrative domains, Domain A and Domain B, connected by four Network Elements (NEs). Domain A has a FlexE group UNI on the left, and Domain B has an Ethernet UNI on the right. Two signal paths are shown: one for PCS encoded signals using BMP/TTT+GMP/GMP overhead and another for MAC client signals using GFP-F overhead. Both paths converge on an ODUk signal between the third and fourth NEs.](df79d6dd5d005b721cf6bcab34d6e12d_img.jpg)
+
+The diagram illustrates the signal flow for two cases of interconnection between a FlexE UNI and an Ethernet UNI through two OTN administrative domains (Domain A and Domain B) and four Network Elements (NEs).
+
+- Top Path (PCS encoded):** At the FlexE group UNI in Domain A, an xG FlexE client signal is processed by a FlexE shim and then mapped into an ODUk signal using BMP/TTT+GMP/GMP overhead at the first NE. This ODUk signal is transported through the second NE in Domain A, the third NE at the boundary between Domain A and Domain B, and the fourth NE in Domain B to the Ethernet UNI.
+- Bottom Path (MAC client):** At the FlexE group UNI in Domain A, an xG FlexE client signal is processed by a FlexE shim and then mapped into an ODUk signal using GFP-F overhead at the first NE. This ODUk signal is transported through the second NE in Domain A, the third NE at the boundary, and the fourth NE in Domain B to the Ethernet UNI.
+
+Reference: G.709-Y.1331(16)-Amd.3(19)\_FXIV.1
+
+Figure XIV.1: Ethernet PCS encoded or MAC signal interconnection between an Ethernet UNI and a FlexE UNI in case I. The diagram shows two OTN administrative domains, Domain A and Domain B, connected by four Network Elements (NEs). Domain A has a FlexE group UNI on the left, and Domain B has an Ethernet UNI on the right. Two signal paths are shown: one for PCS encoded signals using BMP/TTT+GMP/GMP overhead and another for MAC client signals using GFP-F overhead. Both paths converge on an ODUk signal between the third and fourth NEs.
+
+**Figure XIV.1 – Ethernet PCS encoded or MAC signal interconnection between an Ethernet UNI and a FlexE UNI in case I**
+
+Figure XIV.2 illustrates an implementation of case II. For the case of an Ethernet PCS encoded client service, the mapping method conversion is performed at an intermediate node in the domain with the FlexE Group UNI. In this node, the FlexE Client signal is demapped from the ODUflex and then the FlexE Client signal is converted into the corresponding Ethernet PCS encoded signal and then mapped into an ODUk using BMP, TTT+GMP or GMP as specified in clause 17. At the same time, the overhead from ODUflex and OPUflex carrying the FlexE Client signal is converted into the overhead of ODUk and OPUk carrying the Ethernet PCS encoded signal. This conversion maintains the overhead information with the exception of the value of the Payload Type. The specific overhead conversion is vendor specific and outside the scope of this Recommendation.
+
+For the case of an Ethernet MAC client service with a bit rate below and including 100 Gbit/s, the mapping method conversion is performed at an intermediate node in the domain with the FlexE Group UNI. In this node, the FlexE Client signal is demapped from the ODUflex and the Ethernet MAC frames stream is extracted. Then the Ethernet MAC frames stream is mapped into an ODUk using GFP-F as specified in clause 17. At the same time, the overhead from ODUflex and OPUflex carrying the FlexE Client signal is converted into the overhead of the ODUk and OPUk carrying the Ethernet MAC frames stream. This conversion maintains the overhead information with the exception of the value of the Payload Type. The specific overhead conversion is vendor specific and outside the scope of this Recommendation.
+
+![Diagram showing Ethernet PCS encoded or Ethernet MAC client services interconnection between an Ethernet UNI and a FlexE UNI in case II. The diagram illustrates two paths: one for PCS encoded services and another for MAC client services, both traversing OTN administrative domains A and B via Network Elements (NEs).](6043644d04a0b251ad3e2ba078ae5ce4_img.jpg)
+
+The diagram illustrates the interconnection of Ethernet services over an OTN network. It is divided into two main sections representing different service types: PCS encoded and MAC client.
+
+- Top Section (PCS encoded):**
+  - On the left, a **FlexE group UNI** connects to a **FlexE shim**.
+  - The **FlexE shim** connects to an **xG FlexE client**.
+  - This client connects to an **NE** (Network Element) within **OTN administrative Domain A**.
+  - Inside Domain A, there are two more **NE**s connected in series.
+  - The third **NE** in Domain A connects to an **ETCxGR** block.
+  - The **ETCxGR** block is associated with **BMP/TTT+GMP/GMP** protocols.
+  - An **ODUflex** path is shown between the second and third **NE** in Domain A, with an **OH conversion** indicated.
+  - The **ODUflex** path continues from the third **NE** in Domain A, through an **OH conversion**, to an **ODUk** path.
+  - The **ODUk** path traverses **OTN administrative Domain B**, which contains two **NE**s.
+  - At the end of Domain B, the **ODUk** path connects to another **ETCxGR** block, also associated with **BMP/TTT+GMP/GMP**.
+  - This **ETCxGR** block connects to an **Ethernet UNI** on the right.
+  - There are also dashed lines indicating connections from the **NE**s in Domain A and Domain B back to the **xG FlexE client** and **ETCxGR** blocks respectively.
+- Bottom Section (MAC client):**
+  - Similar to the top section, a **FlexE group UNI** connects to a **FlexE shim**, which connects to an **xG FlexE client**.
+  - This client connects to an **NE** in **OTN administrative Domain A**.
+  - Inside Domain A, there are two more **NE**s.
+  - The third **NE** in Domain A connects to an **xG MAC** block.
+  - The **xG MAC** block is associated with **GFP-F** protocol.
+  - An **ODUflex** path is shown between the second and third **NE** in Domain A, with an **OH conversion** indicated.
+  - The **ODUflex** path continues from the third **NE** in Domain A, through an **OH conversion**, to an **ODUk** path.
+  - The **ODUk** path traverses **OTN administrative Domain B**, which contains two **NE**s.
+  - At the end of Domain B, the **ODUk** path connects to an **xG MAC** block, associated with **GFP-F** protocol.
+  - This **xG MAC** block connects to an **ETCxGR** block.
+  - The **ETCxGR** block connects to an **Ethernet UNI** on the right.
+  - Dashed lines indicate connections from the **NE**s in Domain A and Domain B back to the **xG FlexE client** and **xG MAC** blocks respectively.
+
+G.709-Y.1331(16)-Amd.3(19)\_FXIV.2
+
+Diagram showing Ethernet PCS encoded or Ethernet MAC client services interconnection between an Ethernet UNI and a FlexE UNI in case II. The diagram illustrates two paths: one for PCS encoded services and another for MAC client services, both traversing OTN administrative domains A and B via Network Elements (NEs).
+
+**Figure XIV.2 – Ethernet PCS encoded or Ethernet MAC client services interconnection between an Ethernet UNI and a FlexE UNI in case II**
+
+## Appendix XV
+
+### Examples of ODUflex(GFP) and ODUflex(IMP) clock generation methods
+
+(This appendix does not form an integral part of this Recommendation.)
+
+This appendix describes examples of clock generation methods that support ODUflex(GFP) and ODUflex(IMP) signals.
+
+ODUflex(GFP) and ODUflex(IMP) signals are generated using a local clock or the timing of its client signal (if available). The local clock may be the local server ODUk (or OTUk) clock, the local ODUCn (or OTUCn) clock, or an equipment internal clock of the signal over which the ODUflex is carried through the equipment.
+
+#### XV.1 Client timing based
+
+In this method, the clock of the 64B/66B encoded packet client (e.g., FlexE Client) signal is used as reference clock for the generation of the ODUflex(IMP) signal and adjusted by means of a fixed X/Y value, with  $X = 239$  and  $Y = 238$ . The ODUflex(IMP) bit rate is  $239/238 \times$  bit rate of 64B/66B encoded packet client.
+
+#### XV.2 Local clock based
+
+In this method, a local clock with a bit rate tolerance of  $\pm 20$  ppm is used as reference clock for the generation of the ODUflex(GFP) and ODUflex(IMP) signals. This local clock is the same clock that is used to generate a server ODUk/OTUk or ODUCn/OTUCn or equipment specific server signal over which the ODUflex is carried. The bit rates of the ODUflex(GFP) and ODUflex(IMP) signals generated at the A and Z ends of the trail will be  $X_A \pm 20$  ppm and  $X_Z \pm 20$  ppm. These two rates do not have to be identical. In the worst case, these two rates could be  $[2 \times (100 - 20)] = 160$  ppm apart from each other to comply with the ODUflex(GFP) and ODUflex(IMP) bit rate of  $X$  Gbit/s  $\pm 100$  ppm, in which  $X$  represents the nominal bidirectional bit rate as illustrated in Figure XV.1.
+
+![Figure XV.1: General ODUflex(GFP) and ODUflex(IMP) bit rate and tolerance diagram. The diagram shows a horizontal line representing the nominal bidirectional rate X. At the left end (A-end), there is a vertical tick mark labeled X_A with a tolerance of ± 20 ppm. At the right end (Z-end), there is a vertical tick mark labeled X_Z with a tolerance of ± 20 ppm. The distance between the X_A and X_Z tick marks is labeled ≤ 160 ppm. Above the line, a double-headed arrow indicates the nominal bidirectional rate X with a tolerance of ≤ (2 × 100) ppm. Below the line, the text 'Nominal TX rate A-end' is under X_A and 'Nominal TX rate Z-end' is under X_Z. To the right of the line, the text 'ODUflex (GFP) bit rate' and 'ODUflex (IMP) bit rate' are shown.](7d541b1af37d2613847d8a95376efa0c_img.jpg)
+
+G.709-Y.1331(20)\_FXV.1
+
+Figure XV.1: General ODUflex(GFP) and ODUflex(IMP) bit rate and tolerance diagram. The diagram shows a horizontal line representing the nominal bidirectional rate X. At the left end (A-end), there is a vertical tick mark labeled X\_A with a tolerance of ± 20 ppm. At the right end (Z-end), there is a vertical tick mark labeled X\_Z with a tolerance of ± 20 ppm. The distance between the X\_A and X\_Z tick marks is labeled ≤ 160 ppm. Above the line, a double-headed arrow indicates the nominal bidirectional rate X with a tolerance of ≤ (2 × 100) ppm. Below the line, the text 'Nominal TX rate A-end' is under X\_A and 'Nominal TX rate Z-end' is under X\_Z. To the right of the line, the text 'ODUflex (GFP) bit rate' and 'ODUflex (IMP) bit rate' are shown.
+
+Figure XV.1 – General ODUflex(GFP) and ODUflex(IMP) bit rate and tolerance
+
+In a first instance, the clock of the server ODU is used as reference clock to generate the ODUflex(GFP) and ODUflex(IMP) clock rate and adjusted by means of a fixed  $C_m$  value, similar to the case of ODUflex(GFP,n,k), or of two alternating  $C_m$  values  $X/X+1$  (similar to the case of ODUflex(FlexE Aware)).
+
+NOTE 1 – The main difference between the ODUflex(GFP) and ODUflex(IMP) clock rate and the ODUflex(GFP,n,k) clock rate is that this latter rate is the maximum rate that can be supported by M 1.25G OPUk tributary slots whereas the first clock rate is just the rate that is sufficient to carry the packet client signal in a GFP-F frame stream or in a 64B/66B encoded signal.
+
+In a second instance, the bit rate of an ODUflex(GFP) and ODUflex(IMP) signal may be generated by means of a local clock circuit that multiplies a local free run clock rate with an Register1/Register2 multiplier of which the value of Register1 is configured via a first N-bit register and the value of Register2 is configured via a second N-bit register so that the ODUflex(GFP) and ODUflex(IMP) bit rate is equal to  $\text{Register1/Register2} \times \text{Datapath\_Width} \times \text{System\_Clock rate}$ , with  $N \geq 16$ . The Register1/Register2 value is related to the agreed bandwidth of the packet client signal (i.e.,  $238/239 \times \text{Register1/Register2}$ ). For the case of ODUflex(IMP), this clock is also provided to the packet client as reference clock for the generation of the 64B/66B encoded signal to restrict the difference in bit rate of the 64B/66B encoded packet client and the bandwidth of the OPUflex(IMP)\_Payload to a value that is within the range that IMP can address.
+
+NOTE 2 – ODUflex(GFP,n,k) signals can be supported by ODUflex(GFP) signals; for example for the case of a  $\text{Datapath\_Width} \times \text{System\_Clock rate}$  being equal to  $99.5328 \text{ Gbit/s} \pm 20 \text{ ppm}$  the ODUflex(GFP,n,k=2) is supported by e.g., ODUflex(GFP, *REG1*= $n \times 28$ , *REG2*=2231), the ODUflex(GFP,n,k=3) is supported by e.g., ODUflex(GFP, *REG1*= $n \times 35$ , *REG2*=2777), and the ODUflex(GFP,n,k=4) is supported by e.g., ODUflex(GFP, *REG1*= $n \times 44$ , *REG2*=3365).
+
+NOTE 3 – ODUflex(IMP,s) signals can be supported by ODUflex(IMP) signals; for example for the case of a  $\text{Datapath\_Width} \times \text{System\_Clock rate}$  being equal to  $99.5328 \text{ Gbit/s} \pm 20 \text{ ppm}$  the ODUflex(IMP,s) is supported by e.g., ODUflex(IMP, *REG1*= $s \times 9$ , *REG2*=173).
+
+## Bibliography
+
+- [b-ITU-T G-Sup.43] ITU-T G-series Recommendations – Supplement 43 (2011), *Transport of IEEE 10GBASE-R in optical transport networks (OTN)*.
+- [b-ITU-T G-Sup.56] ITU-T G-series Recommendations – Supplement 56 (2016), *OTN Transport of CPRI signals*.
+- [b-ITU-T G-Sup.58] ITU-T G-series Recommendations – Supplement 58 (2020), *Optical transport network (OTN) module framer interfaces (MFIs)*.
+- [b-ANSI INCITS 296] ANSI INCITS 296-1997, *Information Technology – Single-Byte Command Code Sets CONnection (SBCON) Architecture*.
+- [b-ANSI INCITS 364] ANSI INCITS 364-2003, *Information Technology – Fibre Channel 10 Gigabit (10GFC)*.
+- [b-CPRI] CPRI Specification V5.0 (2011-09-21), *Common Public Radio Interface (CPRI), Interface Specification*.
+- [b-IB ARCH] InfiniBand Trade Association (2006), *InfiniBand Architecture Specification, Volume 2, Release 1.2.1*.
+- [b-IEEE 1588] IEEE 1588:2013, *Precision Time Protocol Time Synchronization Performance*.
+- [b-IETF RFC 6205] IETF RFC 6205 (2011), *Generalized Labels for Lambda-Switch-Capable (LSC) Label Switching Routers*.
+- [b-INCITS 488] INCITS 488:2016, *Information Technology – Fibre Channel Framing and Signaling – 4 (FC-FS-4)*.
+- [b-INCITS 470] INCITS 470:2011, *Information Technology – Fibre Channel – Framing and Signaling – 3 (FC-FS-3)*.
+
+
+
+## ITU-T Y-SERIES RECOMMENDATIONS
+
+## GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS, NEXT-GENERATION NETWORKS, INTERNET OF THINGS AND SMART CITIES
+
+|                                                                    |                      |
+|--------------------------------------------------------------------|----------------------|
+| <b>GLOBAL INFORMATION INFRASTRUCTURE</b>                           |                      |
+| General                                                            | Y.100–Y.199          |
+| Services, applications and middleware                              | Y.200–Y.299          |
+| Network aspects                                                    | Y.300–Y.399          |
+| Interfaces and protocols                                           | Y.400–Y.499          |
+| Numbering, addressing and naming                                   | Y.500–Y.599          |
+| Operation, administration and maintenance                          | Y.600–Y.699          |
+| Security                                                           | Y.700–Y.799          |
+| Performances                                                       | Y.800–Y.899          |
+| <b>INTERNET PROTOCOL ASPECTS</b>                                   |                      |
+| General                                                            | Y.1000–Y.1099        |
+| Services and applications                                          | Y.1100–Y.1199        |
+| Architecture, access, network capabilities and resource management | Y.1200–Y.1299        |
+| <b>Transport</b>                                                   | <b>Y.1300–Y.1399</b> |
+| Interworking                                                       | Y.1400–Y.1499        |
+| Quality of service and network performance                         | Y.1500–Y.1599        |
+| Signalling                                                         | Y.1600–Y.1699        |
+| Operation, administration and maintenance                          | Y.1700–Y.1799        |
+| Charging                                                           | Y.1800–Y.1899        |
+| IPTV over NGN                                                      | Y.1900–Y.1999        |
+| <b>NEXT GENERATION NETWORKS</b>                                    |                      |
+| Frameworks and functional architecture models                      | Y.2000–Y.2099        |
+| Quality of Service and performance                                 | Y.2100–Y.2199        |
+| Service aspects: Service capabilities and service architecture     | Y.2200–Y.2249        |
+| Service aspects: Interoperability of services and networks in NGN  | Y.2250–Y.2299        |
+| Enhancements to NGN                                                | Y.2300–Y.2399        |
+| Network management                                                 | Y.2400–Y.2499        |
+| Network control architectures and protocols                        | Y.2500–Y.2599        |
+| Packet-based Networks                                              | Y.2600–Y.2699        |
+| Security                                                           | Y.2700–Y.2799        |
+| Generalized mobility                                               | Y.2800–Y.2899        |
+| Carrier grade open environment                                     | Y.2900–Y.2999        |
+| <b>FUTURE NETWORKS</b>                                             | <b>Y.3000–Y.3499</b> |
+| <b>CLOUD COMPUTING</b>                                             | <b>Y.3500–Y.3599</b> |
+| <b>BIG DATA</b>                                                    | <b>Y.3600–Y.3799</b> |
+| <b>QUANTUM KEY DISTRIBUTION NETWORKS</b>                           | <b>Y.3800–Y.3999</b> |
+| <b>INTERNET OF THINGS AND SMART CITIES AND COMMUNITIES</b>         |                      |
+| General                                                            | Y.4000–Y.4049        |
+| Definitions and terminologies                                      | Y.4050–Y.4099        |
+| Requirements and use cases                                         | Y.4100–Y.4249        |
+| Infrastructure, connectivity and networks                          | Y.4250–Y.4399        |
+| Frameworks, architectures and protocols                            | Y.4400–Y.4549        |
+| Services, applications, computation and data processing            | Y.4550–Y.4699        |
+| Management, control and performance                                | Y.4700–Y.4799        |
+| Identification and security                                        | Y.4800–Y.4899        |
+| Evaluation and assessment                                          | Y.4900–Y.4999        |
+
+For further details, please refer to the list of ITU-T Recommendations.
+
+## SERIES OF ITU-T RECOMMENDATIONS
+
+|                 |                                                                                                                                                           |
+|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Series A        | Organization of the work of ITU-T                                                                                                                         |
+| Series D        | Tariff and accounting principles and international telecommunication/ICT economic and policy issues                                                       |
+| Series E        | Overall network operation, telephone service, service operation and human factors                                                                         |
+| Series F        | Non-telephone telecommunication services                                                                                                                  |
+| <b>Series G</b> | <b>Transmission systems and media, digital systems and networks</b>                                                                                       |
+| Series H        | Audiovisual and multimedia systems                                                                                                                        |
+| Series I        | Integrated services digital network                                                                                                                       |
+| Series J        | Cable networks and transmission of television, sound programme and other multimedia signals                                                               |
+| Series K        | Protection against interference                                                                                                                           |
+| Series L        | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant |
+| Series M        | Telecommunication management, including TMN and network maintenance                                                                                       |
+| Series N        | Maintenance: international sound programme and television transmission circuits                                                                           |
+| Series O        | Specifications of measuring equipment                                                                                                                     |
+| Series P        | Telephone transmission quality, telephone installations, local line networks                                                                              |
+| Series Q        | Switching and signalling, and associated measurements and tests                                                                                           |
+| Series R        | Telegraph transmission                                                                                                                                    |
+| Series S        | Telegraph services terminal equipment                                                                                                                     |
+| Series T        | Terminals for telematic services                                                                                                                          |
+| Series U        | Telegraph switching                                                                                                                                       |
+| Series V        | Data communication over the telephone network                                                                                                             |
+| Series X        | Data networks, open system communications and security                                                                                                    |
+| Series Y        | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities                               |
+| Series Z        | Languages and general software aspects for telecommunication systems                                                                                      |
\ No newline at end of file
diff --git a/marked/G/T-REC-G.7721.1-202508-I_PDF-E/raw.md b/marked/G/T-REC-G.7721.1-202508-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..67e01d56e967175420d78700ced0b01325b15f88
--- /dev/null
+++ b/marked/G/T-REC-G.7721.1-202508-I_PDF-E/raw.md
@@ -0,0 +1,723 @@
+
+
+# Recommendation
+
+# **ITU-T G.7721.1 (08/2025)**
+
+SERIES G: Transmission systems and media, digital systems and networks
+
+Data over Transport – Generic aspects – Transport network control aspects
+
+---
+
+# **Data model of synchronization management**
+
+![ITU logo](84a1d09fb489061482111515543b60dc_img.jpg)
+
+The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue circular emblem with a stylized globe and the letters 'ITU' in white.
+
+ITU logo
+
+## ITU-T G-SERIES RECOMMENDATIONS **Transmission systems and media, digital systems and networks**
+
+|                                                                                                                                              |                      |
+|----------------------------------------------------------------------------------------------------------------------------------------------|----------------------|
+| INTERNATIONAL TELEPHONE CONNECTIONS AND CIRCUITS                                                                                             | G.100-G.199          |
+| GENERAL CHARACTERISTICS COMMON TO ALL ANALOGUE CARRIER-TRANSMISSION SYSTEMS                                                                  | G.200-G.299          |
+| INDIVIDUAL CHARACTERISTICS OF INTERNATIONAL CARRIER TELEPHONE SYSTEMS ON METALLIC LINES                                                      | G.300-G.399          |
+| GENERAL CHARACTERISTICS OF INTERNATIONAL CARRIER TELEPHONE SYSTEMS ON RADIO-RELAY OR SATELLITE LINKS AND INTERCONNECTION WITH METALLIC LINES | G.400-G.449          |
+| COORDINATION OF RADIOTELEPHONY AND LINE TELEPHONY                                                                                            | G.450-G.499          |
+| TRANSMISSION MEDIA AND OPTICAL SYSTEMS CHARACTERISTICS                                                                                       | G.600-G.699          |
+| DIGITAL TERMINAL EQUIPMENTS                                                                                                                  | G.700-G.799          |
+| DIGITAL NETWORKS                                                                                                                             | G.800-G.899          |
+| DIGITAL SECTIONS AND DIGITAL LINE SYSTEM                                                                                                     | G.900-G.999          |
+| MULTIMEDIA QUALITY OF SERVICE AND PERFORMANCE – GENERIC AND USER-RELATED ASPECTS                                                             | G.1000-G.1999        |
+| TRANSMISSION MEDIA CHARACTERISTICS                                                                                                           | G.6000-G.6999        |
+| DATA OVER TRANSPORT – GENERIC ASPECTS                                                                                                        | G.7000-G.7999        |
+| General                                                                                                                                      | G.7000-G.7099        |
+| <b>Transport network control aspects</b>                                                                                                     | <b>G.7700-G.7799</b> |
+| PACKET OVER TRANSPORT ASPECTS                                                                                                                | G.8000-G.8999        |
+| ACCESS NETWORKS                                                                                                                              | G.9000-G.9999        |
+
+*For further details, please refer to the list of ITU-T Recommendations.*
+
+# Recommendation ITU-T G.7721.1
+
+# Data model of synchronization management
+
+## Summary
+
+Recommendation ITU-T G.7721.1 specifies the synchronization information models and data models for transport network elements (NEs) to support specific interface protocols and specific management and control (MC) functions.
+
+The information models are interface protocol neutral and specified using the unified modelling language (UML).
+
+The data models are interface protocol specific and are directly derived from these information models. The specific data models considered in this Recommendation include, but are not limited to, yet another next generation (YANG) data models.
+
+The specific MC functions for synchronization covered by this Recommendation are specified in Recommendations ITU-T G.8265.1, ITU-T G.8275.1 and ITU-T G.8275.2.
+
+The precision time protocol (PTP) telecom profile YANG modules defined in this Recommendation augments:
+
+- The PTP YANG module defined in IETF RFC 8575 for the management of the precision time protocol (PTP) defined in IEEE 1588-2008.
+- The PTP-TT YANG module defined in IEEE 1588e-2024 for the management of the precision time protocol (PTP) defined in IEEE 1588-2019, with the inclusive language.
+
+The UML information model and YANG data model in this version of the Recommendation covers the PTP telecom profiles defined in Recommendations ITU-T G.8265.1, ITU-T G.8275.1 and ITU-T G.8275.2.
+
+Amendment 1 updates the Recommendation to align the data model for PTP telecom profile with the latest editions of PTP Telecom Profiles Recommendations (i.e., ITU-T G.8265.1 Edition 4.1, ITU-T G.8275.1 Edition 4.2 and ITU-T G.8275.2 Edition 3.2).
+
+This revision updates ITU-T G.7721.1 to add the YANG data model for SyncPhy in alignment with the data set defined in Recommendation ITU-T G.781 Edition 5.2 and the SyncPhy information model defined in Recommendation ITU-T G.7721.
+
+## History\*
+
+| Edition | Recommendation               | Approval   | Study Group | Unique ID          |
+|---------|------------------------------|------------|-------------|--------------------|
+| 1.0     | ITU-T G.7721.1               | 2022-06-06 | 15          | 11.1002/1000/14915 |
+| 1.1     | ITU-T G.7721.1 (2022) Amd. 1 | 2024-12-07 | 15          | 11.1002/1000/16149 |
+| 2.0     | ITU-T G.7721.1               | 2025-08-22 | 15          | 11.1002/1000/16398 |
+
+## Keywords
+
+Data model, management, synchronization.
+
+---
+
+\* To access the Recommendation, type the URL <https://handle.itu.int/> in the address field of your web browser, followed by the Recommendation's unique ID.
+
+## FOREWORD
+
+The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, and information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis.
+
+The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics.
+
+The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1.
+
+In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC.
+
+## NOTE
+
+In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party.
+
+## INTELLECTUAL PROPERTY RIGHTS
+
+ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process.
+
+As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at <https://www.itu.int/ITU-T/ipr/>.
+
+© ITU 2025
+
+All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU.
+
+## Table of Contents
+
+|                                                                                   | Page |
+|-----------------------------------------------------------------------------------|------|
+| 1 Scope.....                                                                      | 1    |
+| 2 References.....                                                                 | 1    |
+| 3 Definitions .....                                                               | 2    |
+| 3.1 Terms defined elsewhere .....                                                 | 2    |
+| 3.2 Terms defined in this Recommendation.....                                     | 2    |
+| 4 Abbreviations and acronyms .....                                                | 2    |
+| 5 Conventions .....                                                               | 3    |
+| 5.1 Information modelling conventions .....                                       | 3    |
+| 6 Synchronization functions .....                                                 | 3    |
+| 6.1 Precision time protocol (PTP) telecom profiles .....                          | 3    |
+| 6.2 SyncPhy functions .....                                                       | 3    |
+| 7 Synchronization management information models .....                             | 3    |
+| 7.1 PTP telecom profiles management information model .....                       | 4    |
+| 7.2 SyncPhy management information model.....                                     | 11   |
+| 7.3 Synchronization UML information models.....                                   | 11   |
+| 8 Synchronization data models .....                                               | 11   |
+| 8.1 Synchronization YANG data models .....                                        | 11   |
+| Annex A – Management conformance for PTP telecom profiles YANG data models .....  | 13   |
+| A.1 Configuration of optional YANG data nodes.....                                | 13   |
+| A.2 Reporting values in the operational datastore .....                           | 13   |
+| Annex B – Using the IETF PTP YANG data model for ITU-T PTP telecom profiles ..... | 15   |
+| Appendix I – YANG deviation example for the PTP YANG data model.....              | 16   |
+| Bibliography.....                                                                 | 17   |
+
+Electronic attachment: The UML information model, the YANG data model described in clauses 7 and 8 and the ptp deviation example YANG module described in Appendix I.
+
+
+
+# Recommendation ITU-T G.7721.1
+
+## Data model of synchronization management<sup>1</sup>
+
+# 1 Scope
+
+This Recommendation specifies the synchronization information models and data models for transport network elements (NEs) to support specific interface protocols and specific management and control (MC) functions.
+
+The specific MC functions for synchronization covered by this Recommendation are specified in [ITU-T G.8265.1], [ITU-T G.8275.1] and [ITU-T G.8275.2].
+
+The information models are interface protocol neutral and specified using the unified modelling language (UML). The information models of this Recommendation are derived through pruning and refactoring from the [ITU-T G.7711] core information model and the [ITU-T G.7721] synchronization base information model.
+
+The data models are interface protocol specific and are directly derived from these information models. The specific data models considered in this Recommendation include, but are not limited to, yet another next generation (YANG) data models.
+
+The precision time protocol (PTP) telecom profile YANG module defined in this Recommendation augments:
+
+- The PTP YANG module defined in [IETF RFC 8575] for the management of the precision time protocol (PTP) defined in [IEEE 1588-2008].
+- The PTP-TT YANG module, defined in [IEEE 1588e-2024] for the management of the precision time protocol (PTP), defined in [IEEE 1588-2019], with inclusive language.
+
+The UML information model and YANG data model in this version of the Recommendation covers the PTP telecom profiles defined in [ITU-T G.8265.1], [ITU-T G.8275.1], and [ITU-T G.8275.2].
+
+Amendment 1 updates the Recommendation to align the data model for PTP telecom profile with the latest editions of PTP telecom profiles Recommendations (i.e., [ITU-T G.8265.1] Edition 4.1, [ITU-T G.8275.1] Edition 4.2 and [ITU-T G.8275.2] Edition 3.2).
+
+This revision updates ITU-T G.7721.1 to add the YANG data model for SyncPhy in alignment with the data set defined in [ITU-T G.781] Edition 5.2 and the SyncPhy information model defined in [ITU-T G.7721].
+
+# 2 References
+
+The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation.
+
+[ITU-T G.781] Recommendation ITU-T G.781 (2024), *Synchronization layer functions for frequency synchronization based on the physical layer*.
+
+---
+
+<sup>1</sup> This Recommendation includes an electronic attachment containing the UML information model, the YANG data model described in clauses 7 and 8 and the ptp deviation example YANG module described Appendix I.
+
+- [ITU-T G.7711] Recommendation ITU-T G.7711 (2025), *Generic protocol-neutral information model for transport resources*.
+- [ITU-T G.7721] Recommendation ITU-T G.7721 (2025), *Management requirement and information model for synchronization*.
+- [ITU-T G.8265.1] Recommendation ITU-T G.8265.1/Y.1365.1 (2022), *Precision time protocol telecom profile for frequency synchronization*.
+- [ITU-T G.8275.1] Recommendation ITU-T G.8275.1/Y.1369.1 (2022), *Precision time protocol telecom profile for phase/time synchronization with full timing support from the network*.
+- [ITU-T G.8275.2] Recommendation ITU-T G.8275.2/Y.1369.2 (2022), *Precision time protocol telecom profile for phase/time synchronization with partial timing support from the network*.
+- [IEEE 1588-2008] IEEE Std 1588<sup>TM</sup>-2008, *IEEE Standard for a Precision Clock Synchronization Protocol for Networked Measurement and Control Systems*.
+- [IEEE 1588-2019] IEEE Std 1588<sup>TM</sup>-2019, *IEEE Standard for a Precision Clock Synchronization Protocol for Networked Measurement and Control Systems*.
+- [IEEE 1588e-2024] IEEE Std 1588e<sup>TM</sup>-2024, *IEEE Standard for a Precision Clock Synchronization Protocol for Networked Measurement and Control Systems Amendment: MIB and YANG Modules*.
+- [IETF RFC 7950] RFC 7950 (2016), *The YANG 1.1 Data Modeling Language*.
+- [IETF RFC 8340] RFC 8340 (2018), *YANG Tree Diagrams*.
+- [IETF RFC 8342] RFC 8342 (2018), *Network Management Datastore Architecture (NMDA)*.
+- [IETF RFC 8343] RFC 8343 (2018), *A YANG Data Model for Interface Management*.
+- [IETF RFC 8575] RFC 8575 (2019), *YANG Data Model for the Precision Time Protocol (PTP)*.
+
+# 3 Definitions
+
+## 3.1 Terms defined elsewhere
+
+None.
+
+## 3.2 Terms defined in this Recommendation
+
+None.
+
+# 4 Abbreviations and acronyms
+
+This Recommendation uses the following abbreviations and acronyms:
+
+|      |                                    |
+|------|------------------------------------|
+| CASC | Configuration and Switch Control   |
+| LTP  | Logical Termination Point          |
+| NE   | Network Element                    |
+| PTP  | Precision Time Protocol            |
+| TT   | Time transmitter and Time receiver |
+| UML  | Unified Modelling Language         |
+| YANG | Yet Another Next Generation        |
+
+# 5 Conventions
+
+## 5.1 Information modelling conventions
+
+### UML modelling conventions
+
+See [ITU-T G.7711] clause 5.1.
+
+### Model artefact lifecycle stereotypes conventions
+
+See [ITU-T G.7711] clause 5.2.
+
+### Forwarding entity terminology conventions
+
+See clause 5.3 of [ITU-T G.7711].
+
+### Conditional package conventions
+
+See clause 5.4 of [ITU-T G.7711].
+
+### Pictorial diagram conventions
+
+See clause 5.5 of [ITU-T G.7711].
+
+# 6 Synchronization functions
+
+This clause identifies the synchronization functions that are modelled by the information model and data models of this Recommendation.
+
+## 6.1 Precision time protocol (PTP) telecom profiles
+
+The precision time protocol (PTP) is defined in [IEEE 1588-2008] and in [IEEE 1588-2019].
+
+ITU-T has developed a set of PTP telecom profiles, as listed in Table 6-1.
+
+**Table 6-1 – ITU-T PTP telecom profiles**
+
+| ITU-T PTP telecom profiles                                               | Reference        |
+|--------------------------------------------------------------------------|------------------|
+| Frequency synchronization                                                | [ITU-T G.8265.1] |
+| Phase/time synchronization, with full timing support from the network    | [ITU-T G.8275.1] |
+| Phase/time synchronization, with partial timing support from the network | [ITU-T G.8275.2] |
+
+## 6.2 SyncPhy functions
+
+ITU-T has developed the following frequency synchronization based on the physical layer (SyncPhy) datasets in [ITU-T G.781]:
+
+- defaultDS: defines members for the default device attributes of a physical layer clock.
+- currentDS: defines members for the current device attributes of a physical layer clock.
+- parentDS: defines members for the clock source attributes of a physical layer clock.
+- portDS: defines members for the port attributes of a physical layer port.
+
+The information model of this Recommendation for SyncPhy functions aligns with the SyncPhy model defined in [ITU-T G.7721].
+
+# 7 Synchronization management information models
+
+This clause contains the unified modelling language (UML) information model of the synchronization functions identified in clause 6. The information model is derived through pruning and refactoring
+
+the [ITU-T G.7711] core information model and the [ITU-T G.7721] synchronization base information model.
+
+There are two synchronization management information models, one for the ITU-T PTP telecom profiles, and one for SyncPhy.
+
+## 7.1 PTP telecom profiles management information model
+
+Considering backward compatibility with the PTP telecom profile module defined in the first version of this Recommendation, three models are defined:
+
+- PTP telecom profile types module, which provides common definitions used by the PTP-time transmitter and time receiver (TT) telecom profile module and the PTP telecom profile module.
+- PTP telecom profile module, which augments the IETF PTP model, defined in [IETF RFC 8575], supports only implementations of the ITU-T PTP telecom profiles based on [IEEE 1588-2008].
+- PTP-TT telecom profile module, which augments the IEEE PTP-TT model, defined in [IEEE 1588e-2024] using inclusive language, and which supports the implementations of ITU-T PTP telecom profiles based on [IEEE 1588-2008] or on [IEEE 1588-2019].
+
+The scenarios of PTP telecom profiles YANG are summarized in Table 7-1.
+
+**Table 7-1 – Scenarios of PTP telecom profiles YANG**
+
+|                     | Base specification | Base YANG                            | YANG augmentations                              |
+|---------------------|--------------------|--------------------------------------|-------------------------------------------------|
+| <b>Scenario I</b>   | [IEEE 1588-2008]   | ietf-ptp<br>[IETF RFC 8575]          | itut-ptp-telecom-profile<br>[ITU-T G.7721.1]    |
+| <b>Scenario II</b>  | [IEEE 1588-2008]   | ieee1588-ptp-tt<br>[IEEE 1588e-2024] | itut-ptp-tt-telecom-profile<br>[ITU-T G.7721.1] |
+| <b>Scenario III</b> | [IEEE 1588-2019]   | ieee1588-ptp-tt<br>[IEEE 1588e-2024] | itut-ptp-tt-telecom-profile<br>[ITU-T G.7721.1] |
+
+It is worth noting that the first version of this Recommendation supports only Scenario I, and that:
+
+- migration from Scenario I to either Scenario II or Scenario III is non-backward compatible because the migration from the IETF PTP model, defined in [IETF RFC 8575] and IEEE PTP-TT model, defined in [IEEE 1588e-2024], is not backward compatible;
+- migration from Scenario II to Scenario III is backward compatible.
+
+For the implementations of ITU-T PTP telecom profiles developed after Edition 1.1 (12/2024) of this Recommendation, it is recommended to use the PTP-TT telecom profile module.
+
+It is worth noting that the names of the YANG data nodes defined in [IETF RFC 8575] and in Edition 1.0 of this Recommendation use the legacy terminology, while the names of the YANG data nodes defined from Edition 1.1 onwards of this Recommendation use the new terminology.
+
+The users of the itut-ptp-telecom-profile YANG data model are assumed to be familiar with both terminologies, as described in Appendix XII of [ITU-T G.8275].
+
+### 7.1.1 PTP telecom profile types module
+
+The PTP telecom profile types module provides common definitions used by the PTP-TT telecom profile module and the PTP telecom profile module.
+
+#### 7.1.1.1 Required object classes and relations
+
+An overview of the PTP telecom profile types UML is illustrated in Figure 7-1 (also available in the electronic attachment).
+
+![Figure 7-1 – PTP telecom profile types UML overview. This UML diagram shows the relationships between several classes: PtpTelecomProfileType, PtpTlpDeviceType, G.8265.1_DeviceType, G.8275.1_DeviceType, PtpProfileVersion, and PtpTlpProfileIdentifier. It also shows two default packages, CommonPtpTlpDefaultDsPac and CommonPtpTlpDefaultDsPac, with their respective attributes and associations. Associations are labeled with 'PruneAndRefactor' and 'CommonPtpTlpDefaultDsPacRealizesPtpTlpDefaultDsPac'.](e9314c83043183351ed74908e9bf2f90_img.jpg)
+
+Figure 7-1 – PTP telecom profile types UML overview. This UML diagram shows the relationships between several classes: PtpTelecomProfileType, PtpTlpDeviceType, G.8265.1\_DeviceType, G.8275.1\_DeviceType, PtpProfileVersion, and PtpTlpProfileIdentifier. It also shows two default packages, CommonPtpTlpDefaultDsPac and CommonPtpTlpDefaultDsPac, with their respective attributes and associations. Associations are labeled with 'PruneAndRefactor' and 'CommonPtpTlpDefaultDsPacRealizesPtpTlpDefaultDsPac'.
+
+Figure 7-1 – PTP telecom profile types UML overview
+
+NOTE – The conformance level (when different from CONDITIONAL), default value and value range of the attributes are defined in the relevant PTP telecom profile Recommendations, particularly in clause A.2 of [ITU-T G.8265.1], clause A.2 of [ITU-T G.8275.1] or clause A.2 of [ITU-T G.8275.2].
+
+#### 7.1.1.2 Required attributes and operations
+
+This clause shows (from Table 7-2 to Table 7-6) how the required attributes and operations defined in [ITU-T G.7721] are pruned or refactored for the management of the PTP telecom profile types module.
+
+Table 7-2 – PTP attributes for data types
+
+| Data types in [ITU-T G.7721]                                                                                             | PTP telecom profile types |
+|--------------------------------------------------------------------------------------------------------------------------|---------------------------|
+| PtpTelecomProfileType                                                                                                    | Refactored (copied)       |
+| PtpTlpDeviceType                                                                                                         | Pruned (Note)             |
+| G.8265.1_DeviceType                                                                                                      | Pruned (Note)             |
+| G.8275.1_DeviceType                                                                                                      | Pruned (Note)             |
+| G.8275.1_DeviceType                                                                                                      | Pruned (Note)             |
+| PtpProfileVersion                                                                                                        | Refactored (copied)       |
+| PtpTlpProfileIdentifier                                                                                                  | Pruned (Note)             |
+| NOTE – Different pruning and refactoring rules for the PTP telecom profile module and the PTP-TT telecom profile module. |                           |
+
+Table 7-3 – PTP attributes for CommonPtpDefaultDsPac
+
+| Attributes in [ITU-T G.7721]                                                                                                                                | PTP telecom profile types |
+|-------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------|
+| maxStepsRemoved (Note 1)                                                                                                                                    | Pruned (Note 1)           |
+| instanceEnable (Note 1)                                                                                                                                     | Pruned (Note 1)           |
+| All other attributes                                                                                                                                        | Pruned (Note 2)           |
+| NOTE 1 – Different pruning and refactoring rules for the PTP telecom profile module and the PTP-TT telecom profile module.                                  |                           |
+| NOTE 2 – All the other attributes are pruned because already defined in both [IEEE 1588e-2024] PTP-TT YANG model and in the [IETF RFC 8575] PTP YANG model. |                           |
+
+**Table 7-4 – PTP attributes for CommonPtpTlpDefaultDsPac**
+
+| Attributes in [ITU-T G.7721]                                                                                             | PTP telecom profile types |
+|--------------------------------------------------------------------------------------------------------------------------|---------------------------|
+| deviceType                                                                                                               | Pruned (Note)             |
+| localPriority                                                                                                            | Refactored (copied)       |
+| profileIdentifier                                                                                                        | Pruned (Note)             |
+| NOTE – Different pruning and refactoring rules for the PTP telecom profile module and the PTP-TT telecom profile module. |                           |
+
+**Table 7-5 – PTP attributes for CommonPtpPortDsPac**
+
+| Attributes in [ITU-T G.7721]                                                                                                                                | PTP telecom profile types |
+|-------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------|
+| timeTransmitterOnly                                                                                                                                         | Pruned (Note 1)           |
+| portEnable                                                                                                                                                  | Pruned (Note 1)           |
+| All other attributes                                                                                                                                        | Pruned (Note 2)           |
+| NOTE 1 – Different pruning and refactoring rules for the PTP telecom profile module and the PTP-TT telecom profile module.                                  |                           |
+| NOTE 2 – All the other attributes are pruned because already defined in both [IEEE 1588e-2024] PTP-TT YANG model and in the [IETF RFC 8575] PTP YANG model. |                           |
+
+**Table 7-6 – PTP attributes for CommonPtpTlpPortDsPac**
+
+| Attributes in [ITU-T G.7721] | PTP telecom profile types |
+|------------------------------|---------------------------|
+| localPriority                | Refactored (copied)       |
+| sf                           | Refactored (copied)       |
+| syncReceiptTimeout           | Refactored (copied)       |
+| delayRespReceiptTimeout      | Refactored (copied)       |
+| notTimeTransmitter           | Refactored (copied)       |
+| monitorSender                | Refactored (copied)       |
+| monitorReceiver              | Refactored (copied)       |
+| sfLotm                       | Refactored (copied)       |
+| sfUnusable                   | Refactored (copied)       |
+| sfSu                         | Refactored (copied)       |
+
+### 7.1.2 PTP telecom profile module
+
+#### 7.1.2.1 Required object classes and relations
+
+The management of the precision time protocol (PTP), defined in [IEEE 1588-2008], is provided by the PTP YANG data model, defined in [IETF RFC 8575].
+
+To assist the PTP telecom profile UML pruning and refactoring and to ensure that the translated PTP telecom profile YANG data model can augment seamlessly the PTP YANG data model, the PTP YANG data model, defined in [IETF RFC 8575], has been reverse-engineered into UML form.
+
+Figure 7-2 (also available in the electronic attachment) provides an overview of the PTP UML model, reverse-engineered from the PTP YANG data model defined in [IETF RFC 8575], and of the Spec object classes of the PTP telecom profile UML model, defined in this Recommendation.
+
+![UML overview diagram of the PTP telecom profile. It shows a hierarchy of object classes. Green classes (e.g., PtpTelecomProfileType, PtpTlpDeviceType) are from the PTP YANG data model. Magenta classes (e.g., PtpTelecomProfile, PtpTlpDevice) are from the Interface YANG data model. Blue classes (e.g., PtpTelecomProfileType, PtpTlpDeviceType) are from the PTP telecom profile UML model. The diagram includes associations, inheritance, and composition relationships between these classes.](af7916c89a458fdab6c3f443217388ae_img.jpg)
+
+UML overview diagram of the PTP telecom profile. It shows a hierarchy of object classes. Green classes (e.g., PtpTelecomProfileType, PtpTlpDeviceType) are from the PTP YANG data model. Magenta classes (e.g., PtpTelecomProfile, PtpTlpDevice) are from the Interface YANG data model. Blue classes (e.g., PtpTelecomProfileType, PtpTlpDeviceType) are from the PTP telecom profile UML model. The diagram includes associations, inheritance, and composition relationships between these classes.
+
+G.7721.1(25)
+
+**Figure 7-2 – PTP telecom profile UML overview**
+
+NOTE 1 – The green object classes are from the PTP UML model, reverse-engineered from the PTP YANG data model defined in [IETF RFC 8575]; the magenta object class is from the Interface UML model, reverse-engineered from the Interface YANG data model defined in [IETF RFC 8343], and the blue object classes are from the PTP telecom profile UML model, defined in this Recommendation.
+
+NOTE 2 – The conformance level (when different from CONDITIONAL), default value and value range of the attributes are defined in the relevant PTP Telecom Profile Recommendations, particularly in clause A.2 of [ITU-T G.8265.1], clause A.2 of [ITU-T G.8275.1] or clause A.2 of [ITU-T G.8275.2].
+
+A PTP instance supports one and only one PTP telecom profile; a network element (NE) may support one or multiple PTP instances, each of the instances can represent the same or different PTP profiles.
+
+#### 7.1.2.2 Required attributes and operations
+
+This clause shows (from Table 7-7 to Table 7-11) how the required attributes and operations defined in [ITU-T G.7721] are pruned or refactored for the management of PTP telecom profiles module.
+
+**Table 7-7 – PTP attributes for data types**
+
+| Data types in [ITU-T G.7721] | PTP telecom profile |
+|------------------------------|---------------------|
+| PtpTelecomProfileType        | Pruned (Note 1)     |
+| PtpTlpDeviceType             | Refactored (Note 4) |
+| G.8265.1_DeviceType          | Refactored (Note 4) |
+| G.8275.1_DeviceType          | Refactored (Note 3) |
+| G.8275.1_DeviceType          | Refactored (Note 4) |
+| PtpProfileVersion            | Pruned (Note 1)     |
+| PtpTlpProfileIdentifier      | Pruned (Note 2)     |
+
+NOTE 1 – Pruned because already refactored in the CommonPtpTlpDefaultDsPac object class.  
+NOTE 2 – Refactored as profile, profileVersion and profileIdentifier attributes of the PtpTlpDefaultDsPac object data class, for backward compatibility with G.7721.1 v1.0.  
+NOTE 3 – Refactored as G.8275.1\_ClockType and without the T-TC enumeration literal, for backward compatibility with G.7721.1 v1.0.  
+NOTE 4 – Refactored as clockType, G.8265.1\_ClockType and G.8275.2\_ClockType, for backward compatibility with G.7721.1 v1.0.
+
+**Table 7-8 – PTP attributes for PtpDefaultDsPac**
+
+| <b>Attributes in [ITU-T G.7721]</b>                                                                                                      | <b>PTP telecom profile</b> |
+|------------------------------------------------------------------------------------------------------------------------------------------|----------------------------|
+| maxStepsRemoved                                                                                                                          | Refactored (Note 1)        |
+| instanceEnable                                                                                                                           | Refactored (Note 1)        |
+| All other attributes                                                                                                                     | Pruned (Note 2)            |
+| NOTE 1 – Copied, because not defined in the IETF RFC 8575 PTP YANG model.<br>NOTE 2 – Already defined in [IETF RFC 8575] PTP YANG model. |                            |
+
+**Table 7-9 – PTP attributes for PtpTlpDefaultDsPac**
+
+| <b>Attributes in [ITU-T G.7721]</b>                                                                                                                                                                                                                                                                             | <b>PTP telecom profile</b> |
+|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------|
+| deviceType                                                                                                                                                                                                                                                                                                      | Refactored (Note 1)        |
+| localPriority                                                                                                                                                                                                                                                                                                   | Pruned (Note 2)            |
+| profileIdentifier                                                                                                                                                                                                                                                                                               | Refactored (Note 3)        |
+| NOTE 1 – Refactored as clockType, for backward compatibility with G.7721.1 v1.0.<br>NOTE 2 – Pruned because already refactored in the CommonPtpTlpDefaultDsPac object class.<br>NOTE 3 – Refactored as profile, profileVersion and profileIdentifier attributes, for backward compatibility with G.7721.1 v1.0. |                            |
+
+**Table 7-10 – PTP attributes for PtpPortDsPac**
+
+| <b>Attributes in [ITU-T G.7721]</b>                                                                                                                                                                                                                                             | <b>PTP telecom profile</b> |
+|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------|
+| timeTransmitterOnly                                                                                                                                                                                                                                                             | Refactored (Note 1)        |
+| portEnable                                                                                                                                                                                                                                                                      | Refactored (Note 2)        |
+| All other attributes                                                                                                                                                                                                                                                            | Pruned (Note 3)            |
+| NOTE 1 – Refactored as masterOnly, for backward compatibility with G.7721.1 v1.0 and not defined in the IETF RFC 8575 PTP YANG model.<br>NOTE 2 – Copied, because not defined in the IETF RFC 8575 PTP YANG model.<br>NOTE 3 – Already defined in IETF RFC 8575 PTP YANG model. |                            |
+
+**Table 7-11 – PTP attributes for PtpTlpPortDsPac**
+
+| <b>Attributes in [ITU-T G.7721]</b>                                                 | <b>PTP telecom profile</b> |
+|-------------------------------------------------------------------------------------|----------------------------|
+| localPriority                                                                       | Pruned (Note)              |
+| sf                                                                                  | Pruned (Note)              |
+| syncReceiptTimeout                                                                  | Pruned (Note)              |
+| delayRespReceiptTimeout                                                             | Pruned (Note)              |
+| notTimeTransmitter                                                                  | Pruned (Note)              |
+| monitorSender                                                                       | Pruned (Note)              |
+| monitorReceiver                                                                     | Pruned (Note)              |
+| sfLotm                                                                              | Pruned (Note)              |
+| sfUnusable                                                                          | Pruned (Note)              |
+| sfSu                                                                                | Pruned (Note)              |
+| NOTE – Pruned because already refactored in the CommonPtpTlpPortDsPac object class. |                            |
+
+### 7.1.3 PTP-TT telecom profile module
+
+#### 7.1.3.1 Required object classes and relations
+
+The management of the precision time protocol (PTP) with inclusive language, defined in [IEEE 1588-2019], is provided by the PTP-TT YANG data model, defined in [IEEE 1588e-2024].
+
+To assist the PTP telecom profile UML pruning and refactoring and to ensure that the translated PTP telecom profile YANG data model can augment seamlessly the PTP YANG data model, the PTP YANG data model, defined in [IEEE 1588e-2024], has been reverse-engineered into UML form.
+
+Figure 7-3 (also available in the electronic attachment) provides an overview of the PTP UML model, reverse-engineered from the PTP YANG data model defined in [IEEE 1588e-2024], and of the Spec object classes of the PTP telecom profile UML model, defined in this Recommendation.
+
+![Figure 7-3 – PTP-TT telecom profile UML overview. This UML diagram shows the structure of the PTP-TT telecom profile. It includes several object classes: PtpTelecomProfileType (blue, Enumeration), PtpTlpDeviceType (blue, DataType), G.8265.1_DeviceType (blue, Enumeration), G.8275.1_DeviceType (blue, Enumeration), and PtpProfileVersion (blue, DataType). It also shows relationships like 'PtpTelecomProfileTypeRealizesPtpTelecomProfileType' and 'PtpTlpDeviceTypeRealizesPtpTlpDeviceType'. Attributes and references are listed within the classes, such as 'localPriority', 'twoStepFlag', 'delayRequestTimeout', and 'masterSender'.](9b6b5924b48bf2fd5f347f88f06f45b3_img.jpg)
+
+Figure 7-3 – PTP-TT telecom profile UML overview. This UML diagram shows the structure of the PTP-TT telecom profile. It includes several object classes: PtpTelecomProfileType (blue, Enumeration), PtpTlpDeviceType (blue, DataType), G.8265.1\_DeviceType (blue, Enumeration), G.8275.1\_DeviceType (blue, Enumeration), and PtpProfileVersion (blue, DataType). It also shows relationships like 'PtpTelecomProfileTypeRealizesPtpTelecomProfileType' and 'PtpTlpDeviceTypeRealizesPtpTlpDeviceType'. Attributes and references are listed within the classes, such as 'localPriority', 'twoStepFlag', 'delayRequestTimeout', and 'masterSender'.
+
+Figure 7-3 – PTP-TT telecom profile UML overview
+
+NOTE 1 – The green object classes are from the PTP UML model, reverse-engineered from the PTP YANG data model defined in [IEEE 1588e-2024]; the magenta object class is from the Interface UML model, reverse-engineered from the Interface YANG data model defined in [IEEE 1588e-2024], and the blue object classes are from the PTP telecom profile UML model, defined in this Recommendation.
+
+NOTE 2 – The conformance level (when different from CONDITIONAL), default value and value range of the attributes are defined in the relevant PTP Telecom Profile Recommendations, particularly in clause A.2 of [ITU-T G.8265.1], clause A.2 of [ITU-T G.8275.1] or clause A.2 of [ITU-T G.8275.2].
+
+A PTP instance supports one and only one PTP telecom profile; a network element (NE) may support one or multiple PTP instances, each of the instances can represent the same or different PTP profiles.
+
+#### 7.1.3.2 Required attributes and operations
+
+This clause shows (from Table 7-12 to Table 7-16) how the required attributes and operations defined in [ITU-T G.7721] are pruned or refactored for the management of the PTP-TT telecom profile module.
+
+Table 7-12 – PTP attributes for data types
+
+| Data types in [ITU-T G.7721] | PTP-TT telecom profile |
+|------------------------------|------------------------|
+| PtpTelecomProfileType        | Pruned (Note)          |
+| PtpTlpDeviceType             | Refactored (copied)    |
+| G.8265.1_DeviceType          | Refactored (copied)    |
+| G.8275.1_DeviceType          | Refactored (copied)    |
+| G.8275.1_DeviceType          | Refactored (copied)    |
+| PtpProfileVersion            | Pruned (Note)          |
+
+**Table 7-12 – PTP attributes for data types**
+
+| <b>Data types in [ITU-T G.7721]</b>                                                    | <b>PTP-TT telecom profile</b>    |
+|----------------------------------------------------------------------------------------|----------------------------------|
+| PtpTlpProfileIdentifier                                                                | Refactored (copied)localPriority |
+| NOTE – Pruned because already refactored in the CommonPtpTlpDefaultDsPac object class. |                                  |
+
+**Table 7-13 – PTP attributes for PtpDefaultDsPac**
+
+| <b>Attributes in [ITU-T G.7721]</b>                            | <b>PTP-TT telecom profile</b> |
+|----------------------------------------------------------------|-------------------------------|
+| maxStepsRemoved                                                | Pruned (Note)                 |
+| instanceEnable                                                 | Pruned (Note)                 |
+| All other attributes                                           | Pruned (Note)                 |
+| NOTE – Already defined in [IEEE 1588e-2024] PTP-TT YANG model. |                               |
+
+**Table 7-14 – PTP attributes for PtpTlpDefaultDsPac**
+
+| <b>Attributes in [ITU-T G.7721]</b>                                                    | <b>PTP-TT telecom profile</b> |
+|----------------------------------------------------------------------------------------|-------------------------------|
+| deviceType                                                                             | Refactored (copied)           |
+| localPriority                                                                          | Pruned (Note)                 |
+| profileIdentifier                                                                      | Refactored (copied)           |
+| NOTE – Pruned because already refactored in the CommonPtpTlpDefaultDsPac object class. |                               |
+
+**Table 7-15 – PTP attributes for PtpPortDsPac**
+
+| <b>Attributes in [ITU-T G.7721]</b>                            | <b>PTP-TT telecom profile</b> |
+|----------------------------------------------------------------|-------------------------------|
+| timeTransmitterOnly                                            | Pruned (Note)                 |
+| portEnable                                                     | Pruned (Note)                 |
+| All other attributes                                           | Pruned (Note)                 |
+| NOTE – Already defined in [IEEE 1588e-2024] PTP-TT YANG model. |                               |
+
+**Table 7-16 – PTP attributes for PtpTlpPortDsPac**
+
+| <b>Attributes in [ITU-T G.7721]</b>                                                 | <b>PTP-TT telecom profile</b> |
+|-------------------------------------------------------------------------------------|-------------------------------|
+| localPriority                                                                       | Pruned (Note)                 |
+| sf                                                                                  | Pruned (Note)                 |
+| syncReceiptTimeout                                                                  | Pruned (Note)                 |
+| delayRespReceiptTimeout                                                             | Pruned (Note)                 |
+| notTimeTransmitter                                                                  | Pruned (Note)                 |
+| monitorSender                                                                       | Pruned (Note)                 |
+| monitorReceiver                                                                     | Pruned (Note)                 |
+| sfLotm                                                                              | Pruned (Note)                 |
+| sfUnusable                                                                          | Pruned (Note)                 |
+| sfSu                                                                                | Pruned (Note)                 |
+| NOTE – Pruned because already refactored in the CommonPtpTlpPortDsPac object class. |                               |
+
+## 7.2 SyncPhy management information model
+
+The G.7721.1 SyncPhy management information model is not defined. The G.7721.1 SyncPhy YANG data model is directly derived from the [ITU-T G.7721] SyncPhy UML model through a combined process of pruning, refactoring and translation.
+
+## 7.3 Synchronization UML information models
+
+The UML information models defined in this Recommendation can be downloaded from [this](#) link.
+
+This zip file contains the following folders:
+
+- The G.7721.1\_v1.1 folder, which contains the following:
+  - The .project file
+  - The .di, .notation, and .uml files of the itut-ptp-telecom-profile-types model
+  - The .di, .notation, and .uml files of the itut-ptp-telecom-profile model
+  - The .di, .notation, and .uml files of the itut-ptp-tt-telecom-profile model
+  - The Diagrams folder, which contains PNG images of the UML diagrams in the above models.
+  - The Doc folder, which contains the data dictionaries (DDs) and the DD templates of the above models.
+  - The UmlProfiles folder, which contains the UML profiles that define the properties of the UML artifacts.
+- The G.7711\_v4.0 folder, which contains the [ITU-T G.7711] Core information model, which is imported by the G.7711.1 models above.
+- The IetfModels\_v1.2 folder, which contains the UML information –models, reverse-engineered from the IETF YANG data models, which are imported by the G.7721.1 models above.
+- The IeeeModels\_v1.2 folder, which contains the UML information models, reverse-engineered from the IEEE YANG data models, which are imported by the G.7721.1 models above.
+
+The UML information models above have been developed using the Papyrus 2020-06 modelling tool, which is available at [b-Eclipse-Papyrus]. The installation guide for Eclipse and Papyrus can be found in [b-ONF TR-515].
+
+To load the ITU-T G.7721.1 UML models into a Papyrus workspace, follow the steps below:
+
+- In the *Project Explorer* / right click / *Import* / *General* / *Projects from Folder or Archive* / *Next* / *Archive* / *Select* the G.7721.1 zip file / *Open* / *Select* the folders of the models to be loaded (Note) / *Finish*
+
+NOTE – If an UML model imported by the G.7721.1 models above already exist in the workspace, should not be selected for loading.
+
+# 8 Synchronization data models
+
+This clause contains the interface-protocol-specific data models of the synchronization functions identified in clause 6. These data models are translated from the interface-protocol-neutral UML information specified in clause 7.
+
+## 8.1 Synchronization YANG data models
+
+The YANG data models defined in this Recommendation can be downloaded from [this](#) link.
+
+The zip file includes the following files:
+
+- The .yang and .tree files of the itut-ptp-telecom-profile-types module
+- The .yang and .tree files of the itut-ptp-telecom-profile module
+- The .yang and .tree files of the itut-ptp-tt-telecom-profile module
+- The .yang and .tree files of the itut-sync-phy module
+
+The YANG data models specified in this Recommendation use the YANG 1.1 language specified in [IETF RFC 7950]. The tree format specified in [IETF RFC 8340] is used for the YANG data model tree representation. The YANG data models specified in this Recommendation conform to the network management datastore architecture specified in [IETF RFC 8342].
+
+The PTP telecom profile YANG data model, as defined in this clause, augments the PTP YANG data model, as defined in [IETF RFC 8575], to manage PTP instances which are compliant with the ITU-T telecom profiles, as outlined in clause 6.1.
+
+Since the PTP YANG data model defined in [IETF RFC 8575] supports only the management of the PTP implementations based on the [IEEE 1588-2008] version, the PTP telecom profile YANG data model, defined in this Recommendation, supports only the management of the PTP telecom profile implementations which are based on the [IEEE 1588-2008] version.
+
+Since the PTP YANG data model, as defined in [IETF RFC 8575], has a broader scope than the management of the ITU-T PTP telecom profile instances, Annex B provides some guidelines on how the PTP YANG data model shall be used to manage the ITU-T PTP telecom profile instances.
+
+The YANG model of this Recommendation is translated from the interface-protocol-neutral UML information provided in clause 7.3. The translation is done with the assistance of the Open-Source translation tooling xmi2yang, which is developed according to [b-ONF TR-531] mapping guidelines.
+
+At the time of publication of this Recommendation, the xmi2yang mapping tool is still a work in progress. Therefore, manual modifications on the tool-generated yang are necessary.
+
+## Annex A
+
+## Management conformance for PTP telecom profiles YANG data models
+
+(This annex forms an integral part of this Recommendation.)
+
+The YANG data models defined in [IETF RFC 8575], [IEEE 1588e-2024] and in this Recommendation defines almost all the data nodes as optional, to accommodate different conformance requirements that depend on the PTP profile being used.
+
+The only mandatory data nodes in the YANG data modules defined in this Recommendation are those which define which PTP telecom profile and device type apply to a given PTP instance, when it is configured to support any PTP telecom profile.
+
+The ITU-T PTP telecom profiles Recommendations, which are listed in clause 6.1, define for each dataset members the default value, the value range and the operational conformance (mandatory, optional or not used), which depend on the configured PTP telecom profile and device type.
+
+### A.1 Configuration of optional YANG data nodes
+
+With the exception of the PTP telecom profile and device type, all the YANG data nodes which correspond to configurable dataset members are optional to be configured in the running data store.
+
+When a YANG data node, which corresponds to a configurable and mandatory dataset member, is not configured in the running datastore, the system shall apply the default value, defined for the corresponding dataset member.
+
+When a YANG data node, which corresponds to a configurable, optional and supported dataset member, is not configured in the running datastore, the system shall apply the default value, defined for the corresponding dataset member.
+
+NOTE – As required in section 5.3 of [IETF RFC 8342], the system always reports, within the operational datastore, the values in use, regardless of the default value definition.
+
+When a YANG data node, which corresponds to a configurable, optional and not supported dataset member, is configured in the running datastore, the system shall either reject the configuration and reply with an error message, or accept the configuration, not apply it and reply with a warning message. The warning or the error message shall notify the client that the optional dataset member is not supported by the system.
+
+When a YANG data node, which corresponds to a configurable and not used dataset member, is configured in the running datastore, the system shall either reject the configuration and reply with an error message, or accept the configuration, not apply it and reply with a warning message. The warning or the error message shall notify the client that the dataset member is not supported by the configured PTP telecom profile.
+
+When a YANG data node, which corresponds to a configurable dataset member, is configured, in the running datastore, with value outside the range defined for the corresponding dataset member, the system shall reject the configuration and reply with an error message.
+
+### A.2 Reporting values in the operational datastore
+
+As required in section 5.3 of [IETF RFC 8342], the system shall always report, within the operational datastore, the values of the YANG data nodes in use.
+
+Therefore, the system shall report, within the operational datastore, the values of the YANG data nodes, which correspond to mandatory dataset members as well as to optional and supported dataset members. The system shall not report, within the operational datastore, the values of the YANG data
+
+nodes which correspond to not used dataset members as well as to optional and not supported dataset members.
+
+The PTP telecom profile implementation shall ensure that the values of the reported YANG data nodes are within the range defined for the corresponding dataset member.
+
+# Annex B
+
+## Using the IETF PTP YANG data model for ITU-T PTP telecom profiles
+
+(This annex forms an integral part of this Recommendation.)
+
+The YANG conformance guidelines for PTP telecom profiles provided in Annex A are generic and apply when either the IETF PTP YANG data model, defined in [IETF RFC 8575], or the IEEE PTP-TT YANG data model, defined in [IEEE 1588e-2024], are used, together with the PTP YANG data models, defined in this Recommendation, to manage PTP telecom profiles.
+
+This annex provides additional guidelines which are applicable only when the IETF PTP YANG data model, defined in [IETF RFC 8575], is used, together with the PTP YANG data models, defined in this Recommendation, to manage PTP telecom profiles.
+
+The PTP YANG data model in [IETF RFC 8575] defines some default values, using YANG default statements, which differ from the default values defined for the corresponding dataset members by the ITU-T PTP telecom profile Recommendations.
+
+It is not appropriate to allow the system to override the default values defined by YANG default statements. It is therefore recommended that an implementation of the PTP telecom profile YANG data model does not implement the YANG default statements within the PTP YANG data model, defined in [IETF RFC 8575], and reports this using the YANG deviation statements, as defined in section 5.6.3 of [IETF RFC 7950].
+
+Since section 7.20.3 of [IETF RFC 7950] does not allow including YANG deviation statements in standard YANG modules, the definition of these YANG deviation statements is implementation specific. Appendix I provides some guidelines on how deviation statements could be written to report that the YANG default statements in the PTP YANG data model, defined in [IETF RFC 8575], are not implemented.
+
+Moreover, the PTP YANG data model in [IETF RFC 8575], and its augmentations in this Recommendation, support write operations for some attributes which corresponds to static or dynamic dataset members.
+
+When a writable YANG data node, which corresponds to a static or dynamic dataset member, is configured in the running datastore, the system shall reject the configuration and reply with an error message, notifying the client that the static or dynamic dataset members are not configurable.
+
+## Appendix I
+
+## **YANG deviation example for the PTP YANG data model**
+
+(This appendix does not form an integral part of this Recommendation.)
+
+Annex B recommends that an implementation of the PTP telecom profile YANG data model, as defined in clause 8.1.1, also reports, using YANG deviation statements, that the YANG default statement of the PTP YANG data model, defined in [IETF RFC 8575], are not implemented.
+
+Since section 7.20.3 of [IETF RFC 7950] does not allow including YANG deviation statements in standard YANG modules, the definition of these YANG deviation statements is implementation specific.
+
+This appendix provides some guidelines on how these deviation statements could be written by providing, as an example, the `itut-ptp-deviation-example` YANG module which only declares that the YANG default statements of the PTP YANG data model, defined in [IETF RFC 8575] are not supported.
+
+The `itut-ptp-deviation-example` YANG module example (`itut-ptp-deviation-example@2021-09-30.yang`) can be downloaded from [this](#) link.
+
+# Bibliography
+
+- [b-Eclipse-Papyrus] Papyrus Eclipse UML Modelling Tool. <https://www.eclipse.org/papyrus>. Accessed on 17-Nov-2025.
+- [b-ONF TR-515] Papyrus Guidelines 1.3 (2018) [https://opennetworking.org/wp-content/uploads/2018/08/TR-515\\_Papyrus\\_Guidelines\\_v1.3-1-1.pdf](https://opennetworking.org/wp-content/uploads/2018/08/TR-515_Papyrus_Guidelines_v1.3-1-1.pdf). Accessed on 17-Nov-2025.
+- [b-ONF TR-531] UML to YANG Mapping Guidelines (2018) [https://opennetworking.org/wp-content/uploads/2018/08/TR-531\\_UML-YANG\\_Mapping\\_Gdls\\_v1.1-1-1.pdf](https://opennetworking.org/wp-content/uploads/2018/08/TR-531_UML-YANG_Mapping_Gdls_v1.1-1-1.pdf). Accessed on 17-Nov-2025.
+
+
+
+
+
+# SERIES OF ITU-T RECOMMENDATIONS
+
+|                 |                                                                                                                                                           |
+|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Series A        | Organization of the work of ITU-T                                                                                                                         |
+| Series D        | Tariff and accounting principles and international telecommunication/ICT economic and policy issues                                                       |
+| Series E        | Overall network operation, telephone service, service operation and human factors                                                                         |
+| Series F        | Non-telephone telecommunication services                                                                                                                  |
+| <b>Series G</b> | <b>Transmission systems and media, digital systems and networks</b>                                                                                       |
+| Series H        | Audiovisual and multimedia systems                                                                                                                        |
+| Series I        | Integrated services digital network                                                                                                                       |
+| Series J        | Cable networks and transmission of television, sound programme and other multimedia signals                                                               |
+| Series K        | Protection against interference                                                                                                                           |
+| Series L        | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant |
+| Series M        | Telecommunication management, including TMN and network maintenance                                                                                       |
+| Series N        | Maintenance: international sound programme and television transmission circuits                                                                           |
+| Series O        | Specifications of measuring equipment                                                                                                                     |
+| Series P        | Telephone transmission quality, telephone installations, local line networks                                                                              |
+| Series Q        | Switching and signalling, and associated measurements and tests                                                                                           |
+| Series R        | Telegraph transmission                                                                                                                                    |
+| Series S        | Telegraph services terminal equipment                                                                                                                     |
+| Series T        | Terminals for telematic services                                                                                                                          |
+| Series U        | Telegraph switching                                                                                                                                       |
+| Series V        | Data communication over the telephone network                                                                                                             |
+| Series X        | Data networks, open system communications and security                                                                                                    |
+| Series Y        | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities                               |
+| Series Z        | Languages and general software aspects for telecommunication systems                                                                                      |
\ No newline at end of file
diff --git a/marked/G/T-REC-G.989.2-201902-I_PDF-E/raw.md b/marked/G/T-REC-G.989.2-201902-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..9b3a5d6cceabaa531f160c8ac71b446f09b8e1b9
--- /dev/null
+++ b/marked/G/T-REC-G.989.2-201902-I_PDF-E/raw.md
@@ -0,0 +1,3554 @@
+
+
+**ITU-T**
+
+TELECOMMUNICATION  
+STANDARDIZATION SECTOR  
+OF ITU
+
+**G.989.2**
+
+(02/2019)
+
+SERIES G: TRANSMISSION SYSTEMS AND MEDIA,  
+DIGITAL SYSTEMS AND NETWORKS
+
+Digital sections and digital line system – Optical line  
+systems for local and access networks
+
+---
+
+**40-Gigabit-capable passive optical networks 2  
+(NG PON2): Physical media dependent (PMD)  
+layer specification**
+
+Recommendation ITU-T G.989.2
+
+# ITU-T G-SERIES RECOMMENDATIONS **TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS**
+
+|                                                                                                                                              |                    |
+|----------------------------------------------------------------------------------------------------------------------------------------------|--------------------|
+| INTERNATIONAL TELEPHONE CONNECTIONS AND CIRCUITS                                                                                             | G.100–G.199        |
+| GENERAL CHARACTERISTICS COMMON TO ALL ANALOGUE CARRIER-TRANSMISSION SYSTEMS                                                                  | G.200–G.299        |
+| INDIVIDUAL CHARACTERISTICS OF INTERNATIONAL CARRIER TELEPHONE SYSTEMS ON METALLIC LINES                                                      | G.300–G.399        |
+| GENERAL CHARACTERISTICS OF INTERNATIONAL CARRIER TELEPHONE SYSTEMS ON RADIO-RELAY OR SATELLITE LINKS AND INTERCONNECTION WITH METALLIC LINES | G.400–G.449        |
+| COORDINATION OF RADIOTELEPHONY AND LINE TELEPHONY                                                                                            | G.450–G.499        |
+| TRANSMISSION MEDIA AND OPTICAL SYSTEMS CHARACTERISTICS                                                                                       | G.600–G.699        |
+| DIGITAL TERMINAL EQUIPMENTS                                                                                                                  | G.700–G.799        |
+| DIGITAL NETWORKS                                                                                                                             | G.800–G.899        |
+| DIGITAL SECTIONS AND DIGITAL LINE SYSTEM                                                                                                     | G.900–G.999        |
+| General                                                                                                                                      | G.900–G.909        |
+| Parameters for optical fibre cable systems                                                                                                   | G.910–G.919        |
+| Digital sections at hierarchical bit rates based on a bit rate of 2048 kbit/s                                                                | G.920–G.929        |
+| Digital line transmission systems on cable at non-hierarchical bit rates                                                                     | G.930–G.939        |
+| Digital line systems provided by FDM transmission bearers                                                                                    | G.940–G.949        |
+| Digital line systems                                                                                                                         | G.950–G.959        |
+| Digital section and digital transmission systems for customer access to ISDN                                                                 | G.960–G.969        |
+| Optical fibre submarine cable systems                                                                                                        | G.970–G.979        |
+| <b>Optical line systems for local and access networks</b>                                                                                    | <b>G.980–G.989</b> |
+| Metallic access networks                                                                                                                     | G.990–G.999        |
+| MULTIMEDIA QUALITY OF SERVICE AND PERFORMANCE – GENERIC AND USER-RELATED ASPECTS                                                             | G.1000–G.1999      |
+| TRANSMISSION MEDIA CHARACTERISTICS                                                                                                           | G.6000–G.6999      |
+| DATA OVER TRANSPORT – GENERIC ASPECTS                                                                                                        | G.7000–G.7999      |
+| PACKET OVER TRANSPORT ASPECTS                                                                                                                | G.8000–G.8999      |
+| ACCESS NETWORKS                                                                                                                              | G.9000–G.9999      |
+
+*For further details, please refer to the list of ITU-T Recommendations.*
+
+## Recommendation ITU-T G.989.2
+
+# 40-Gigabit-capable passive optical networks 2 (NG-PON2): Physical media dependent (PMD) layer specification
+
+## Summary
+
+Recommendation ITU-T G.989.2 specifies the physical media dependent (PMD) layer requirements for a passive optical network (PON) system with a nominal aggregate capacity of 40 Gbit/s in the downstream direction and 10 Gbit/s in the upstream direction, hereinafter referred to as NG-PON2. NG-PON2 is a flexible optical fibre access network capable of supporting the bandwidth requirements of mobile backhaul, business and residential services. Furthermore, this Recommendation describes optional configurations, to extend beyond this nominal capacity, as the ITU-T G.989 series of Recommendations allows for multiple upstream and downstream line rates.
+
+The NG-PON2 wavelength plan is defined to enable the coexistence through wavelength overlay with legacy PON systems (see ITU-T G.989.1). The transmission convergence (TC) layer is based on Recommendation ITU-T G.987.3, with unique modifications for NG-PON2 captured in Recommendation ITU-T G.989.3. The optical network unit (ONU) management and control interface (OMCI) specifications are described in Recommendation ITU-T G.988 for NG-PON2 extensions.
+
+This Recommendation specifies the characteristics of hybrid time and wavelength division multiplexing (TWDM) channels, referred to as TWDM PON. The characteristics of optional, tunable point-to-point wavelength overlay channels are also described, referred to as point-to-point wavelength division multiplexing (PtP WDM) PON.
+
+The TWDM PON described in this Recommendation represents a further development from the systems described in the ITU-T G.984 and ITU-T G.987 series of Recommendations. To the greatest extent possible, this Recommendation retains the requirements of ITU-T G.984.1 and ITU-T G.987.1 to ensure maximal reuse of existing technology and compatibility with deployed optical access systems and optical fibre infrastructure.
+
+Edition 2.0 continues the maintenance and evolution of physical media dependent (PMD) layer specification.
+
+## History
+
+| Edition | Recommendation              | Approval   | Study Group | Unique ID*                                                                                 |
+|---------|-----------------------------|------------|-------------|--------------------------------------------------------------------------------------------|
+| 1.0     | ITU-T G.989.2               | 2014-12-05 | 15          | <a href="http://www.itu.int/publications/record/11.1002/1000/12097">11.1002/1000/12097</a> |
+| 1.1     | ITU-T G.989.2 (2014) Amd. 1 | 2016-04-13 | 15          | <a href="http://www.itu.int/publications/record/11.1002/1000/12556">11.1002/1000/12556</a> |
+| 1.2     | ITU-T G.989.2 (2014) Amd. 2 | 2017-08-13 | 15          | <a href="http://www.itu.int/publications/record/11.1002/1000/13292">11.1002/1000/13292</a> |
+| 2.0     | ITU-T G.989.2               | 2019-02-06 | 15          | <a href="http://www.itu.int/publications/record/11.1002/1000/13745">11.1002/1000/13745</a> |
+
+## Keywords
+
+NG-PON2, TWDM-PON, PtP WDM-PON
+
+---
+
+\* To access the Recommendation, type the URL <http://handle.itu.int/> in the address field of your web browser, followed by the Recommendation's unique ID. For example, <http://handle.itu.int/11.1002/1000/11830-en>.
+
+## FOREWORD
+
+The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis.
+
+The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics.
+
+The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1.
+
+In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC.
+
+## NOTE
+
+In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party.
+
+## INTELLECTUAL PROPERTY RIGHTS
+
+ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process.
+
+As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at <http://www.itu.int/ITU-T/ipr/>.
+
+© ITU 2019
+
+All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU.
+
+## Table of Contents
+
+###### Page
+
+|            |                                                                                                          |    |
+|------------|----------------------------------------------------------------------------------------------------------|----|
+| 1          | Scope.....                                                                                               | 1  |
+| 2          | References.....                                                                                          | 1  |
+| 3          | Definitions .....                                                                                        | 3  |
+| 4          | Abbreviations and acronyms .....                                                                         | 3  |
+| 5          | Conventions .....                                                                                        | 3  |
+| 6          | Architecture of the optical access network.....                                                          | 3  |
+| 6.1        | Physical grouping of logical functions .....                                                             | 4  |
+| 6.2        | ODN optical path loss (OPL) classes .....                                                                | 4  |
+| 6.3        | Fibre distance classes .....                                                                             | 5  |
+| 7          | Services.....                                                                                            | 5  |
+| 8          | User network interface and service node interface.....                                                   | 5  |
+| 9          | Common optical network requirements.....                                                                 | 5  |
+| 9.1        | Layered structure of optical network.....                                                                | 5  |
+| 9.2        | Wavelength plans for NG-PON2.....                                                                        | 5  |
+| 9.3        | Physical media dependent layer requirements .....                                                        | 6  |
+| 10         | Crosstalk-to-signal ratio tolerance for NG-PON2 .....                                                    | 9  |
+| 10.1       | Wideband X/S tolerance mask definition.....                                                              | 10 |
+| 10.2       | Narrowband TWDM PON X/S tolerance mask .....                                                             | 11 |
+| 11         | TWDM PON PMD layer requirements .....                                                                    | 14 |
+| 11.1       | PMD layer requirements.....                                                                              | 14 |
+| 11.2       | Upstream physical layer overhead.....                                                                    | 34 |
+| Annex A    | – Tunable PtP WDM PON PMD layer requirements.....                                                        | 35 |
+| A.1        | PMD layer requirements.....                                                                              | 36 |
+| Annex B    | – Auxiliary management and control channel .....                                                         | 54 |
+| B.1        | Introduction .....                                                                                       | 54 |
+| B.2        | Transparent AMCC .....                                                                                   | 54 |
+| Annex C    | – Low loss (LL) PtP WDM PON PMD layer requirements.....                                                  | 56 |
+| C.1        | PMD layer requirements.....                                                                              | 56 |
+| Annex D    | – ONU power levelling .....                                                                              | 74 |
+| D.1        | Interaction between NG-PON2 PMD layer and TC layer.....                                                  | 74 |
+| D.2        | Power levelling (PL) mechanism at ONU transmitter .....                                                  | 74 |
+| D.3        | ONU autonomous power levelling.....                                                                      | 74 |
+| D.4        | OOC and OOB PSD relaxation .....                                                                         | 76 |
+| D.5        | OLT directed ONU power levelling.....                                                                    | 76 |
+| D.6        | ONU troubleshooting considerations .....                                                                 | 76 |
+| Appendix I | – Wavelength considerations for NG-PON2, XG-PON1, G-PON and RF video overlay distribution services ..... | 77 |
+
+###### **Page**
+
+|                                                                                                                                                             |     |
+|-------------------------------------------------------------------------------------------------------------------------------------------------------------|-----|
+| Appendix II – Physical layer measurements required to support optical layer supervision ....                                                                | 78  |
+| Appendix III – Allocation of the physical layer overhead time.....                                                                                          | 81  |
+| Appendix IV – Jitter budget specifications for TWDM PON .....                                                                                               | 84  |
+| Appendix V – Measurement of TWDM PON burst mode acquisition time and burst node eye opening at OLT .....                                                    | 85  |
+| Appendix VI – Nonlinear Raman interactions in optical fibres and mitigation technologies for coexistence of multiple PONs.....                              | 86  |
+| Appendix VII – Cyclic AWG channel grid design examples .....                                                                                                | 91  |
+| Appendix VIII – Wavelength multiplexer, upstream inter-channel crosstalk, ONU transmitter tuning time considerations and upstream channel grid example..... | 92  |
+| VIII.1 Wavelength multiplexer .....                                                                                                                         | 92  |
+| VIII.2 Upstream inter-channel crosstalk .....                                                                                                               | 94  |
+| VIII.3 ONU transmitter tuning time.....                                                                                                                     | 98  |
+| VIII.4 TWDM PON upstream channel grid examples.....                                                                                                         | 100 |
+| VIII.5 Detail of OOC near the channel band edge .....                                                                                                       | 101 |
+| Appendix IX – Alternative line code for Raman mitigation.....                                                                                               | 103 |
+| IX.1 8B10B scheme.....                                                                                                                                      | 103 |
+| IX.2 Miller and Miller squared scheme .....                                                                                                                 | 105 |
+| IX.3 Raman mitigation suppression levels .....                                                                                                              | 109 |
+| Appendix X – Upstream PMD examples for TWDM PON .....                                                                                                       | 111 |
+| Appendix XI – Optical parameter specification for the S/R-CP reference point.....                                                                           | 113 |
+| Bibliography.....                                                                                                                                           | 115 |
+
+## Recommendation ITU-T G.989.2
+
+# 40-Gigabit-capable passive optical networks 2 (NG-PON2): Physical media dependent (PMD) layer specification
+
+## 1 Scope
+
+This Recommendation pertains to flexible access networks using optical fibre technology. It describes a network supporting multiple services with bandwidth requirements ranging from that of voice to data and video, running at an aggregate reference downstream rate of 40 Gbit/s.
+
+This Recommendation specifies characteristics of the physical media dependent (PMD) layer of a passive optical network (PON) system based on time and wavelength division multiplexing (TWDM) and an optional point-to-point wavelength division multiplexing (PtP WDM) system that can be used in an overlay to TWDM with the capability of bidirectional data transmission between optical line termination (OLT) and optical network unit (ONU).
+
+The optical access network (OAN) addressed by this Recommendation enables the network operator to provide a flexible upgrade to meet future customer requirements, in particular, in the area of the optical distribution network (ODN). The legacy ODN infrastructure is based on a point-to-multipoint tree and branch option using power splitter based technology (see [ITU-T G.989.1] for additional details). However, the use of wavelength splitters in the ODN is also allowed.
+
+This edition includes updates from Amendment 1, Amendment 2 and relaxes certain parameter values related to OOB/OOC/IBXT.
+
+## 2 References
+
+The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation.
+
+- [ITU-T G.652] Recommendation ITU-T G.652 (2016), *Characteristics of a single-mode optical fibre and cable*.
+- [ITU-T G.657] Recommendation ITU-T G.657 (2016), *Characteristics of a bending-loss insensitive single-mode optical fibre and cable*.
+- [ITU-T G.671] Recommendation ITU-T G.671 (2012), *Transmission characteristics of optical components and subsystems*.
+- [ITU-T G.694.1] Recommendation ITU-T G.694.1 (2012), *Spectral grids for WDM applications: DWDM frequency grid*.
+- [ITU-T G.698.1] Recommendation ITU-T G.698.1 (2009), *Multichannel DWDM applications with single-channel optical interfaces*.
+- [ITU-T G.698.3] Recommendation ITU-T G.698.3 (2012), *Multichannel seeded DWDM applications with single-channel optical interfaces*.
+- [ITU-T G.707] Recommendation ITU-T G.707/Y.1322 (2007), *Network node interface for the synchronous digital hierarchy (SDH)*.
+
+- [ITU-T G.709] Recommendation ITU-T G.709/Y.1331 (2016), *Interfaces for the optical transport network.*
+- [ITU-T G.783] Recommendation ITU-T G.783 (2006), *Characteristics of synchronous digital hierarchy (SDH) equipment functional blocks.*
+- [ITU-T G.825] Recommendation ITU-T G.825 (2000), *The control of jitter and wander within digital networks which are based on the synchronous digital hierarchy (SDH).*
+- [ITU-T G.957] Recommendation ITU-T G.957 (2006), *Optical interfaces for equipments and systems relating to the synchronous digital hierarchy.*
+- [ITU-T G.959.1] Recommendation ITU-T G.959.1 (2018), *Optical transport network physical layer interfaces.*
+- [ITU-T G.982] Recommendation ITU-T G.982 (1996), *Optical access networks to support services up to the ISDN primary rate or equivalent bit rates.*
+- [ITU-T G.983.1] Recommendation ITU-T G.983.1 (2005), *Broadband optical access systems based on Passive Optical Networks (PON).*
+- [ITU-T G.984.1] Recommendation ITU-T G.984.1 (2008), *Gigabit-capable passive optical networks (GPON): General characteristics.*
+- [ITU-T G.984.2] Recommendation ITU-T G.984.2 (2003), *Gigabit-capable Passive Optical Networks (G-PON): Physical Media Dependent (PMD) layer specification.*
+- [ITU-T G.984.5] Recommendation ITU-T G.984.5 (2014), *Gigabit-capable passive optical networks (G-PON): Enhancement band.*
+- [ITU-T G.987] Recommendation ITU-T G.987 (2012), *10-Gigabit-capable passive optical network (XG-PON) systems: Definitions, abbreviations and acronyms.*
+- [ITU-T G.987.1] Recommendation ITU-T G.987.1 (2016), *10 Gigabit-capable passive optical networks (XG-PON): General requirements.*
+- [ITU-T G.987.2] Recommendation ITU-T G.987.2 (2016), *10-Gigabit-capable passive optical networks (XG-PON): Physical media dependent (PMD) layer specification.*
+- [ITU-T G.987.3] Recommendation ITU-T G.987.3 (2014), *10-Gigabit-capable passive optical networks (XG-PON): Transmission convergence (TC) layer specification.*
+- [ITU-T G.988] Recommendation ITU-T G.988 (2017), *ONU management and control interface (OMCI) specification.*
+- [ITU-T G.989] Recommendation ITU-T G.989 (2015), *40-Gigabit-capable passive optical networks (NG-PON2): Definitions, abbreviations and acronyms.*
+- [ITU-T G.989.1] Recommendation ITU-T G.989.1 (2013), *40-Gigabit-capable passive optical networks (NG-PON2): General requirements.*
+- [ITU-T G.989.3] Recommendation ITU-T G.989.3 (2015), *40-Gigabit-capable passive optical networks (NG-PON2): Transmission convergence layer specification.*
+- [ITU-T J.185] Recommendation ITU-T J.185 (2012), *Transmission equipment for transferring multi-channel television signals over optical access networks by frequency modulation conversion.*
+- [ITU-T J.186] Recommendation ITU-T J.186 (2008), *Transmission equipment for multi-channel television signals over optical access networks by sub-carrier multiplexing (SCM).*
+- [ITU-T L.313] Recommendation ITU-T L.313/L.66 (2007), *Optical fibre cable maintenance criteria for in-service fibre testing in access networks.*
+
+## 3 Definitions
+
+See clause 3 of [ITU-T G.989] for definitions.
+
+## 4 Abbreviations and acronyms
+
+See clause 4 of [ITU-T G.989] for abbreviations and acronyms.
+
+## 5 Conventions
+
+See clause 5 of [ITU-T G.989] for conventions.
+
+# 6 Architecture of the optical access network
+
+Figure 6-1 represents the reference logical architecture for the multi-wavelength NG-PON2 system. A multi-system OAN architecture for NG-PON2 coexistence with legacy systems is represented in Figure 5-1 of [ITU-T G.989.1]. During coexistence, mitigation techniques may be necessary to avoid inter-system impairments, e.g., see Appendix VI and Appendix IX for Raman crosstalk considerations. This architecture allows both point-to-multipoint connectivity (i.e., TWDM PON) and virtual point-to-point connectivity (i.e., PtP WDM PON).
+
+![Figure 6-1: NG-PON2 reference logical architecture diagram. The diagram shows multiple NG-PON2 OLTs (CT 1 to CT n) connected to a central Wavelength Mux (WM) via channel pairs (S/R-CP1 to S/R-CPn). The WM is connected to an Optical Distribution Network (ODN) via an interface (IF_NG-PON2). The ODN is connected to multiple NG-PON2 ONUs via interfaces (IF_NG-PON2). Reference points SNI, S/R-CP, S/R-CG, R/S, and UNI are indicated by vertical dashed lines. A legend at the bottom defines CG as channel group, CT as channel termination, CP as channel pair, and WM as wavelength mux. The diagram is labeled G.989.2(14)_F6-1.](a234352dfaccdc24745c88eef7724cc6_img.jpg)
+
+CG – channel group  
+CT – channel termination  
+CP – channel pair  
+WM – wavelength mux
+
+G.989.2(14)\_F6-1
+
+Figure 6-1: NG-PON2 reference logical architecture diagram. The diagram shows multiple NG-PON2 OLTs (CT 1 to CT n) connected to a central Wavelength Mux (WM) via channel pairs (S/R-CP1 to S/R-CPn). The WM is connected to an Optical Distribution Network (ODN) via an interface (IF\_NG-PON2). The ODN is connected to multiple NG-PON2 ONUs via interfaces (IF\_NG-PON2). Reference points SNI, S/R-CP, S/R-CG, R/S, and UNI are indicated by vertical dashed lines. A legend at the bottom defines CG as channel group, CT as channel termination, CP as channel pair, and WM as wavelength mux. The diagram is labeled G.989.2(14)\_F6-1.
+
+**Figure 6-1 – NG-PON2 reference logical architecture**
+
+The following reference points from Figure 6-1 are defined below:
+
+- S: The sending interface to the network.
+- R: The receiving interface from the network.
+- S/R, R/S: Combination of points S and R existing simultaneously in a single fibre, when operating in bidirectional mode. The S/R point is referenced to the OLT side, the R/S point is referenced to the ONU side.
+
+The two directions for optical transmission in the ODN are identified as follows:
+
+- downstream direction for signals travelling from the OLT to the ONU(s); and
+- upstream direction for signals travelling from the ONU(s) to the OLT.
+
+Transmission in downstream and upstream directions takes place in the ODN through the same fibre and components (duplex/diplex configuration).
+
+The primary method of optical parameter specification is in reference to the S/R point for channel group (S/R-CG reference point of Figure 6-1 for the individual wavelength channels). This method is used in the PMD tables appearing in clause 11. An alternative informative optical parameter specification method is in reference to the S/R point for channel pair (S/R-CP reference point of Figure 6-1). The alternative method is applicable in the situations when the primary reference point, S/R-CG, is not practical or not accessible for performing measurements or it is desirable to provide a simple sensitivity specification to an OLT transceiver vendor. The informative optical parameters specification referenced to S/R-CP point (which are consistent with the primary method and are based on industry best practices with respect to the WM loss parameters) are given in Appendix XI.
+
+Each ONU in Figure 6-1 is equipped with a tunable transmitter and a tunable receiver. The tunable ONU transmitter must be able to adjust to the allocated upstream TWDM or PtP WDM wavelength channels within the bands specified in Table 9-1. The tunable ONU receiver must be able to adjust to the allocated downstream TWDM or PtP WDM wavelength channels within the bands specified in Table 9-1.
+
+This Recommendation specifies a minimum of four, with extension up to eight, TWDM channels. A minimum of four PtP WDM channels is supported with a maximum not specified. The number of wavelength channels supported by a given equipment implementation or network instance is not specified; however the optical parameter tables should be consulted for the specific assumptions made for the parameters given.
+
+The architecture can be extended to support multiple OLTs on a common ODN for other purposes such as pay-as-you-grow deployment and spectral flexibility.
+
+## 6.1 Physical grouping of logical functions
+
+The logical functions identified in Figure 6-1 for NG-PON2 could be considered to be individual physical items, or fully integrated into a single device.
+
+## 6.2 ODN optical path loss (OPL) classes
+
+ODN optical path loss classes (ODN classes) are specified in Table 6-1.
+
+The optical path loss for each class is specified between the S/R-CG and R/S reference points. It takes into account a 15 dB differential optical path loss.
+
+**Table 6-1 – ODN optical path loss classes (ODN classes)**
+
+|                                        | Class N1 | Class N2 | Class E1 | Class E2 |
+|----------------------------------------|----------|----------|----------|----------|
+| Minimum optical path loss              | 14 dB    | 16 dB    | 18 dB    | 20 dB    |
+| Maximum optical path loss              | 29 dB    | 31 dB    | 33 dB    | 35 dB    |
+| Maximum differential optical path loss | 15 dB    |          |          |          |
+
+ODNs including gain elements, wavelength couplers or low split ratio power splitters may have optical path losses less than stated minimum loss values above. In such a case, the ODN must contain measures (e.g., optical attenuators) to guarantee the minimum optical path loss for the given class to prevent bit error ratio (BER) degradation and/or potential damage to receivers
+
+## 6.3 Fibre distance classes
+
+Fibre distance classes are specified in Table 6-2.
+
+**Table 6-2 – ODN fibre distance classes**
+
+| Fibre distance class | Minimum fibre distance (km) | Maximum fibre distance (km) |
+|----------------------|-----------------------------|-----------------------------|
+| DD20                 | 0                           | 20                          |
+| DD40                 | 0                           | 40                          |
+
+The following power spectral density (PSD) values in the PMD tables in clause 11 have been optimized for TWDM 4-channel and 20 km. Investigations for TWDM 8 channel and/or DD40 (40 km) are for further study.
+
+## 7 Services
+
+See clause 7 of [ITU-T G.989.1] for services to be carried by NG-PON2.
+
+## 8 User network interface and service node interface
+
+See clause 7 of [ITU-T G.989.1].
+
+# 9 Common optical network requirements
+
+## 9.1 Layered structure of optical network
+
+The layered structure of the NG-PON2 optical network can generally be represented by a structure in which the data plane and the auxiliary management and control plane are mounted on top of the common physical medium, represented by the NG-PON2 ODN.
+
+## 9.2 Wavelength plans for NG-PON2
+
+Table 9-1 specifies the wavelength plans for both TWDM PON and PtP WDM PON. The NG-PON2 wavelength plan is specified to enable the coexistence through wavelength overlay with legacy PON systems, see [ITU-T G.989.1].
+
+Shared spectrum allows full coexistence with G-PON, XG-PON1, radio frequency (RF) video overlay and TWDM. The expanded spectrum option of PtP WDM PON supports spectral flexibility as described in clause 9.2 of [ITU-T G.989.1]. Expanded spectrum can be used in the absence of any one of these coexistence systems.
+
+**Table 9-1 – NG-PON2 wavelength bands**
+
+| Wavelength compatible systems | TWDM PON     |                                                                                                              | PtP WDM PON                                                                                  |
+|-------------------------------|--------------|--------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------|
+|                               | Downstream   | Upstream                                                                                                     | Upstream/downstream                                                                          |
+| GPON, RF video, XG-PON1       | 1596-1603 nm | Wideband option<br>1524-1544 nm<br>Reduced band option<br>1528-1540 nm<br>Narrow band option<br>1532-1540 nm | Expanded spectrum<br>1524-1625 nm<br>(Note 1)<br>Shared spectrum<br>1603-1625 nm<br>(Note 2) |
+
+**Table 9-1 – NG-PON2 wavelength bands**
+
+| <b>Wavelength<br/>compatible systems</b>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        | <b>TWDM PON</b>   |                 | <b>PtP WDM PON</b>         |
+|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------|-----------------|----------------------------|
+|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 | <b>Downstream</b> | <b>Upstream</b> | <b>Upstream/downstream</b> |
+| <p>NOTE 1 – This Recommendation specifies PtP WDM PON anywhere in the spectrum identified in Table 9-1, subject to spectrum otherwise being used. Whenever a particular subset of the spectrum in either band is unused by TWDM PON and/or legacy systems, PtP WDM PON is permitted to make use of that particular sub-band in upstream and/or downstream direction. However, the isolation requirements to the TWDM PON and/or legacy systems must be considered when determining the expanded spectrum wavelengths to be occupied by PtP WDM PON.</p> <p>NOTE 2 – When TWDM PON and PtP WDM PON are both present, wavelength channels of both technologies may occupy adjacent wavelength bands; however, TWDM and PtP WDM channels must not be interleaved. The required guard band between TWDM PON and PtP WDM PON is a minimum of 3 nm when using separate mux/demux devices. In the shared spectrum case, the PtP WDM PON upstream channels use the shorter wavelengths in the shared spectrum. When a single device is used to multiplex PtP WDM PON and TWDM PON, the required guard band is a minimum of 100 GHz.</p> |                   |                 |                            |
+
+The selection of the operating band option in the PtP WDM PON sub-bands depends on the coexistence requirements. In the expanded spectrum case, DWDM grids as specified in [ITU-T G.694.1] or [ITU-T G.698.3] can be used.
+
+## **9.3 Physical media dependent layer requirements**
+
+This clause contains the PMD layer specifications that are common to both TWDM PON and PtP WDM PON. Unique specifications for TWDM PON and PtP WDM PON are contained in respective clauses and annexes of this Recommendation.
+
+#### **9.3.1 Physical media and transmission method**
+
+##### **9.3.1.1 Transmission medium**
+
+This Recommendation is based on the fibre described in [ITU-T G.652]. Other fibre types compatible with this Recommendation, e.g., [ITU-T G.657], may be used for indoor cabling and/or drop section.
+
+##### **9.3.1.2 Transmission direction**
+
+Signals are transmitted both upstream and downstream through the optical transmission medium of the ODN.
+
+##### **9.3.1.3 Transmission method**
+
+Bidirectional transmission is accomplished by use of a wavelength division multiplexing (WDM) technique on a single fibre.
+
+#### **9.3.2 Minimum extinction ratio**
+
+The minimum extinction ratio (ER) is specified in logarithmic form and is expressed in decibels as a positive number. To satisfy the requirement, a component or device must meet or exceed the specified ratio.
+
+To measure signal ER at a single-channel reference point (S/R-CP or R/S) the configuration shown in Figure B.1 of [ITU-T G.957] can be used directly. In the case of measurements at the multichannel reference point (S/R-CG), channel isolation is performed with a reference optical bandpass filter (as described in [ITU-T G.959.1], Annex B) before applying this filter output to the configuration shown in Figure B.1 of [ITU-T G.957].
+
+#### **9.3.3 Maximum reflectance of equipment, measured at the transmitter wavelength**
+
+The maximum reflectance of equipment at S/R-CG or R/S reference point, measured at the transmitter wavelength, specified as a ratio less than one and is expressed in decibels. To satisfy the requirement, a component/device must not exceed the specified ratio.
+
+#### **9.3.4 Tolerance to reflected optical power**
+
+The tolerance to reflected optical power is specified as a ratio less than one and is expressed in decibels. To satisfy the requirement, the transmitter must operate without performance degradation in the presence of the optical reflections at or below the specified tolerance level.
+
+This parameter is shown in [ITU-T G.984.2] as "Tolerance to the transmitter incident light power".
+
+#### **9.3.5 Optical path between S/R and R/S**
+
+##### **9.3.5.1 Attenuation range**
+
+The optical power parameters are specified for four distinct ODN optical path loss classes in clause 6.2. Each class is specified by its respective minimum and maximum optical path loss between the S/R-CG and R/S reference points. The attenuation range is the difference between the maximum and minimum optical path loss in each class.
+
+##### **9.3.5.2 Minimum optical return loss**
+
+The minimum optical return loss (ORL) is specified as a ratio greater than one and is expressed in decibels. To satisfy the requirement, a component/device must meet or exceed the specified ratio.
+
+##### **9.3.5.3 Maximum discrete reflectance between points S and R**
+
+The maximum discrete reflectance is the maximum value of reflectance of any single discrete element in the ODN. The value specified in this Recommendation is lower than  $-35$  dB, also see [ITU-T G.982].
+
+##### **9.3.5.4 Dispersion**
+
+Maximum values of dispersion (ps/nm) are specified in Tables 11-4 to 11-7 for TWDM PON and Tables A.2 to A.7 for PtP WDM PON. These values are consistent with the maximum optical path penalties (OPPs) specified. They take into account the worst-case fibre dispersion coefficient over the operating wavelength band.
+
+#### **9.3.6 Receiver at reference point R**
+
+All parameters are specified as follows, in accordance with Tables 11-4 to 11-7 for TWDM PON and Tables A.2 to A.7 for PtP WDM PON.
+
+##### **9.3.6.1 Receiver sensitivity**
+
+The receiver sensitivity is specified as a power level and is expressed in decibels relative to 1 mW. To satisfy the requirement, a component or device must be qualified at or below the specified power level.
+
+##### **9.3.6.2 Receiver overload**
+
+The receiver overload is specified as a power level and is expressed in decibels relative to 1 mW. To satisfy the requirement, a component/device must be qualified at or above the specified power level.
+
+##### **9.3.6.3 Maximum optical path penalty**
+
+The optical path penalty is specified as a ratio greater than one and is expressed in decibels. The optical link budget for a particular ODN optical loss class is satisfied, only if the difference between the minimum transmitter mean launch optical power (in decibels relative to 1 mW) and the receiver
+
+sensitivity (in decibels relative to 1 mW) is equal to or exceeds the sum of the maximum OPP (in decibels) and the maximum optical path loss (in decibels) specified for the given ODN optical loss class.
+
+##### **9.3.6.4 Maximum reflectance measured at the receiver wavelength**
+
+The maximum reflectance of equipment at S/R-CG or R/S reference point, measured at the receiver wavelength, is specified as a ratio less than one and is expressed in decibels. To satisfy the requirement, a component/device must not exceed the specified ratio.
+
+##### **9.3.6.5 Clock extraction capability**
+
+Conventional clock extraction applies for continuous data transmission, i.e., as used for TWDM PON downstream and PtP WDM PON in both directions.
+
+For TDMA burst mode transmission, the clock of the upstream transmission signal is extracted rapidly from several alternating bits in the preamble. The clock extracted from the preamble is maintained at least during reception of the signal from the delimiter through the end of the upstream assigned burst, or is continuously extracted from the signal after the preamble during reception of the assigned burst.
+
+##### **9.3.6.6 Consecutive identical digit immunity**
+
+The consecutive identical digit (CID) immunity is specified as a bit pattern length. To satisfy the requirement, the system must meet or exceed the specified length.
+
+##### **9.3.6.7 Transmission quality and error performance**
+
+The bit error ratio reference level describes the quality of the transmission system. The BER reference level is specified for performing measurements of the receiver sensitivity and overload. A compliant system provides BER equal to or better than the specified value.
+
+#### **9.3.7 Tunable characteristics for transmitter and receiver**
+
+A key feature of NG-PON2 is the ability to tune the ONU transmitter and receiver. In the OLT to ONU downstream direction, a tunable ONU receiver is required to select the proper wavelength channel. In the ONU to OLT upstream direction, the ONU transmitter is tuned to emit at the desired wavelength channel. There are two characteristics of tunable transmitter/receiver; channel control and wavelength control. For wavelength control, two types of mechanisms are allowed; one requires OLT and ONU interaction to manage the wavelength, the other requires the ONU to be in complete control of the wavelength.
+
+The mechanisms of the tuning process are outside the scope of this Recommendation. Note that the specifications in the optical interface parameter tables in clause 11 and Annex A must be met throughout the tuning process to avoid any rogue behaviour.
+
+The central frequency, spectral excursion, channel spacing (CS) and tuning characteristics are specified in the respective clauses and annexes of this Recommendation. This Recommendation classifies the wavelength channel tuning time of a receiver or transmitter into three classes. These classes may enable different use cases, but the definition of the use cases are outside the scope of this Recommendation.
+
+**Table 9-2 – Classes of transmitter/receiver wavelength channel tuning times**
+
+|           |                                                                                |
+|-----------|--------------------------------------------------------------------------------|
+| Class 1   | < 10 $\mu\text{s}$ , any channel to any channel                                |
+| Class 2   | 10 $\mu\text{s}$ to 25 ms, any channel to any channel                          |
+| Class 2R1 | 10 $\mu\text{s}$ to 25 ms, any channel to a channel not more than 100 GHz away |
+| Class 2R2 | 10 $\mu\text{s}$ to 25 ms, any channel to a channel not more than 200 GHz away |
+| Class 3   | 25 ms to 1 s, any channel to any channel                                       |
+
+#### 9.3.8 Minimum side mode suppression ratio
+
+The minimum side mode suppression ratio (SMSR) is specified in logarithmic form and is expressed in decibels as a positive number. To satisfy the requirement, the component/device must meet or exceed the specified ratio.
+
+SMSR is measured on the laser output, before any filtering. This prevents a significant mode partition noise penalty. Other limitations on out-of-band (OOB)/out-of-channel (OOC) power still apply to the equipment interface.
+
+#### 9.3.9 Out-of-channel power spectral density mask
+
+The OOC-PSD must not exceed certain levels that depend on the optical frequency offset from the nominal channel central frequency ( $f_0$ ). These limits are depicted in Figure 9-1, in terms of the specified CS and the specified maximum spectral excursion (MSE). OOC2 is the limit within the  $\pm \text{MSE}$  interval of each channel, and OOC1 is the limit in between those intervals. A transmitter must comply with the mask when it is tuned anywhere within its MSE. The details of the mask near the band edges are further discussed in App. VIII.5.
+
+![Figure 9-1: OOC-PSD mask definition diagram. The diagram shows a power spectral density mask with a central peak at f0. The peak has a width of ± MSE and a maximum power level of Pmax - 15 dB (0.01 nm resolution). The mask is defined by two levels, OOC1 and OOC2, which are constant within the ± MSE intervals of each channel. The horizontal axis is frequency, with markers for f2, f1, f0, f1, and f2. The vertical axis represents power spectral density. The mask is symmetric around f0. The distance between the centers of adjacent channels is CS. The distance from the center of a channel to the edge of its ± MSE interval is MSE. The distance from the edge of one channel's ± MSE interval to the center of the next channel is CS/2. The diagram is labeled G.989.2(14)_F9-1.](cc8bec39d25eb0aafb5382c05f0d5deb_img.jpg)
+
+Figure 9-1: OOC-PSD mask definition diagram. The diagram shows a power spectral density mask with a central peak at f0. The peak has a width of ± MSE and a maximum power level of Pmax - 15 dB (0.01 nm resolution). The mask is defined by two levels, OOC1 and OOC2, which are constant within the ± MSE intervals of each channel. The horizontal axis is frequency, with markers for f2, f1, f0, f1, and f2. The vertical axis represents power spectral density. The mask is symmetric around f0. The distance between the centers of adjacent channels is CS. The distance from the center of a channel to the edge of its ± MSE interval is MSE. The distance from the edge of one channel's ± MSE interval to the center of the next channel is CS/2. The diagram is labeled G.989.2(14)\_F9-1.
+
+**Figure 9-1 – OOC-PSD mask definition**
+
+# 10 Crosstalk-to-signal ratio tolerance for NG-PON2
+
+In the previously specified PON systems, the crosstalk-to-signal ratio (X/S) tolerance characteristics have applied only to the ONU. However, NG-PON2 is a multi-wavelength architecture and as such, the NG-PON2 wavelength channels not intended for a particular receiver (either at the ONU or at the OLT) can be considered interfering signals. This clause specifies X/S characteristics for both the ONU and the OLT. It is anticipated that the ONU will provide X/S filtering directly at the ONU's receiver; whereas X/S filtering at the OLT will likely be external to the OLT receiver, or
+
+in combination with the receiver. In any case, this Recommendation specifies only the X/S filtering needed and leaves the method of obtaining that X/S to the implementers of this Recommendation.
+
+As NG-PON2 is a multi-wavelength system, interfering signals may derive from other NG-PON2 wavelength channels. In the case of the ONU, interfering signals may also derive from coexisting legacy systems such as G-PON, XG-PON1, RF video overlay and maintenance wavelengths from optical time domain reflectometer (OTDR). To minimize the effect of interfering signals, NG-PON2 receivers need to reject them using an appropriate wavelength filtering. This Recommendation does not specify the isolation characteristics of the wavelength filtering directly, but specifies the X/S tolerance of the NG-PON2 receiver<sup>1</sup>. Here, S is the optical power of an individual wavelength channel within an aggregate NG-PON2 signal, and X is that of the aggregated interfering signals, consisting of legacy signals and other NG-PON2 wavelength channels. Both are measured at the receiver reference point R, corresponding to the IF reference points specified in Figure 6-1.
+
+The interfering signal format for measuring X/S tolerance is a non-return to zero (NRZ) pseudo-random code with the same line rate as the target NG-PON2 signal. In the case of both TWDM PON and PtP WDM PON, eight channels are considered the worst-case configuration.
+
+The wavelength filtering is divided into two parts: a wideband X/S, based on legacy system considerations and a narrowband X/S based on the NG-PON2 wavelength channels.
+
+### 10.1 Wideband X/S tolerance mask definition
+
+This clause describes the generic X/S tolerance of NG-PON2 devices. It makes no assumption about additional services using the wavelength band specified in this Recommendation.
+
+#### 10.1.1 Wideband ONU X/S tolerance
+
+Figure 10-1 shows the generic PON X/S tolerance mask that allows the NG-PON2 ONU receiver to meet its sensitivity requirements in the presence of legacy systems. Implementers need to specify the isolation characteristics of the wavelength filters to obtain enough isolation of the interfering signal(s). The wavelengths and total optical power of all additional services must fall beneath the mask of Figure 10-1 to allow coexistence with NG-PON2 ONUs.
+
+![Figure 10-1: X/S tolerance mask for TWDM PON ONU. The graph shows the X/S (dB) tolerance mask across a wavelength range from 1260 nm to 1675 nm. The mask consists of two shaded regions (hatched) representing the allowed interference levels, separated by a central 'TWDM band' (1596 nm to 1603 nm). The vertical axis is labeled X/S (dB) and Y. The horizontal axis is labeled with wavelengths: 1260, 1581, 1596, 1603, 1625, 1675. A table below the graph defines the mask parameters.](0bd23f00e0632855cfef9274f1ab93d8_img.jpg)
+
+| Class          | Y (dB) |
+|----------------|--------|
+| N1, E1, N2, E2 | 21.5   |
+
+G.989.2(14)\_F10-1
+
+Figure 10-1: X/S tolerance mask for TWDM PON ONU. The graph shows the X/S (dB) tolerance mask across a wavelength range from 1260 nm to 1675 nm. The mask consists of two shaded regions (hatched) representing the allowed interference levels, separated by a central 'TWDM band' (1596 nm to 1603 nm). The vertical axis is labeled X/S (dB) and Y. The horizontal axis is labeled with wavelengths: 1260, 1581, 1596, 1603, 1625, 1675. A table below the graph defines the mask parameters.
+
+Figure 10-1 – X/S tolerance mask for TWDM PON ONU
+
+<sup>1</sup> The X/S definition is intended to capture the worst-case difference in interfering signal levels (X) relative to the intended data signal (S). In order to derive the actual isolation value, the X/S value is added to the required level of isolation from the interfering signal to obtain a stated degradation of "x" dB to the data signal.
+
+S: Received optical power for target channel in TWDM PON downstream band.
+
+X: Maximum total power of other optical signals received in the blocking wavelength band.
+
+X/S: The value in the mask (hatched area) allows the NG-PON2 receiver to meet its sensitivity requirements
+
+The wideband ONU X/S tolerance mask of PtP WDM PON can be derived by analogy with the TWDM PON X/S tolerance mask above. The specific values are for further study (FFS).
+
+#### 10.1.2 Wideband OLT X/S tolerance
+
+The separation of legacy system wavelengths from the NG-PON2 wavelengths is accomplished by the coexistence element (CE), as defined in [ITU-T G.984.5]. This device must have sufficient isolation to allow the OLT to operate within specifications. As the CE is not part of the OLT equipment, there are no requirements on the OLT equipment for wideband X/S tolerance.
+
+## 10.2 Narrowband TWDM PON X/S tolerance mask
+
+The narrowband TWDM PON X/S mask is shown in Figure 10-2, using the particular value tables as given below. The TWDM-PON self-interference configuration is common to both the ONU and OLT. This configuration of one desired wavelength and 14 potentially interfering wavelengths is devised to approximate the worst-case crosstalk situation. Of the 14 interference locations, only seven contiguous points will be populated at any one time. That is to say, if the central frequency is on channel C (C being of the value one through eight), the shortest wavelength interferer would be at channel one and the longest wavelength interferer would be on channel eight. The receiver is required to have its specified sensitivity for the desired signal over the wavelength band  $\lambda_{S-}$  to  $\lambda_{S+}$ , despite the fact that the seven interferers are present with power level X and modulated with a TWDM PON signal format of the same rate as the signal channel.
+
+#### 10.2.1 Narrowband ONU X/S tolerance mask
+
+In addition to the TWDM interferers, there are an assumed eight PtP WDM interferers, both downstream and upstream. The upstream interference channels (which result from the potential for a 32 dB ORL in the ODN) have a power level Y and modulated with an NRZ signal at a similar data rate as the signal channel. The downstream interference channels have a power level Z and are modulated with an NRZ signal at the similar data rate as the signal channel.
+
+The parameters of the downstream mask are given in Table 10-1.
+
+![Figure 10-2 – X/S tolerance mask for TWDM PON. The diagram shows a wavelength spectrum with various signal types and their power levels. From left to right: TWDM interference signals (power level X) at wavelengths λ_{X-6}, λ_{X-5}, λ_{X-4}, λ_{X-3}, λ_{X-2}, λ_{X-1}, λ_{X+1}, λ_{X+2}, λ_{X+3}, λ_{X+4}, λ_{X+5}, λ_{X+6}, λ_{X+7}; a desired signal (power level S) at wavelength λ_C; P2P upstream (reflected) interference signals (power level Y) at wavelengths λ_{Y1}, λ_{Y2}, λ_{Y3}, λ_{Y4}, λ_{Y5}, λ_{Y6}, λ_{Y7}, λ_{Y8}; and P2P downstream interference signals (power level Z) at wavelengths λ_{Z1}, λ_{Z2}, λ_{Z3}, λ_{Z4}, λ_{Z5}, λ_{Z6}, λ_{Z7}, λ_{Z8}. The spectrum is divided into three main regions by break symbols (//). The desired signal is located at λ_C, which is between the TWDM interference signals and the P2P interference signals. The TWDM interference signals are located at wavelengths λ_{X-6} through λ_{X+7}, with a break between λ_{X-1} and λ_{X+1}. The P2P upstream interference signals are located at wavelengths λ_{Y1} through λ_{Y8}, with a break between λ_{Y4} and λ_{Y5}. The P2P downstream interference signals are located at wavelengths λ_{Z1} through λ_{Z8}, with a break between λ_{Z4} and λ_{Z5}. The power levels X, Y, and Z are indicated by horizontal dashed lines with arrows pointing to the corresponding signal groups. The wavelength axis is labeled λ at the far right. The figure is identified by the text G.989.2(14)_F10-2 in the bottom right corner.](a3ee9a6f9fa9251ee0cac2d16e67e620_img.jpg)
+
+Figure 10-2 – X/S tolerance mask for TWDM PON. The diagram shows a wavelength spectrum with various signal types and their power levels. From left to right: TWDM interference signals (power level X) at wavelengths λ\_{X-6}, λ\_{X-5}, λ\_{X-4}, λ\_{X-3}, λ\_{X-2}, λ\_{X-1}, λ\_{X+1}, λ\_{X+2}, λ\_{X+3}, λ\_{X+4}, λ\_{X+5}, λ\_{X+6}, λ\_{X+7}; a desired signal (power level S) at wavelength λ\_C; P2P upstream (reflected) interference signals (power level Y) at wavelengths λ\_{Y1}, λ\_{Y2}, λ\_{Y3}, λ\_{Y4}, λ\_{Y5}, λ\_{Y6}, λ\_{Y7}, λ\_{Y8}; and P2P downstream interference signals (power level Z) at wavelengths λ\_{Z1}, λ\_{Z2}, λ\_{Z3}, λ\_{Z4}, λ\_{Z5}, λ\_{Z6}, λ\_{Z7}, λ\_{Z8}. The spectrum is divided into three main regions by break symbols (//). The desired signal is located at λ\_C, which is between the TWDM interference signals and the P2P interference signals. The TWDM interference signals are located at wavelengths λ\_{X-6} through λ\_{X+7}, with a break between λ\_{X-1} and λ\_{X+1}. The P2P upstream interference signals are located at wavelengths λ\_{Y1} through λ\_{Y8}, with a break between λ\_{Y4} and λ\_{Y5}. The P2P downstream interference signals are located at wavelengths λ\_{Z1} through λ\_{Z8}, with a break between λ\_{Z4} and λ\_{Z5}. The power levels X, Y, and Z are indicated by horizontal dashed lines with arrows pointing to the corresponding signal groups. The wavelength axis is labeled λ at the far right. The figure is identified by the text G.989.2(14)\_F10-2 in the bottom right corner.
+
+Figure 10-2 – X/S tolerance mask for TWDM PON
+
+**Table 10-1 – TWDM PON downstream (ONU receive)  
+X/S parameters**
+
+| Parameter       | Value                                       |
+|-----------------|---------------------------------------------|
+| $\lambda_{X-7}$ | $\lambda_C + \text{MSE} - 7 * \text{CS}$    |
+| $\lambda_{X-6}$ | $\lambda_C + \text{MSE} - 6 * \text{CS}$    |
+| $\lambda_{X-5}$ | $\lambda_C + \text{MSE} - 5 * \text{CS}$    |
+| $\lambda_{X-4}$ | $\lambda_C + \text{MSE} - 4 * \text{CS}$    |
+| $\lambda_{X-3}$ | $\lambda_C + \text{MSE} - 3 * \text{CS}$    |
+| $\lambda_{X-2}$ | $\lambda_C + \text{MSE} - 2 * \text{CS}$    |
+| $\lambda_{X-1}$ | $\lambda_C + \text{MSE} - \text{CS}$        |
+| $\lambda_{S-}$  | $\lambda_C - \text{MSE}$                    |
+| $\lambda_C$     | Central frequency of ONU filter             |
+| $\lambda_{S+}$  | $\lambda_C + \text{MSE}$                    |
+| $\lambda_{X+1}$ | $\lambda_C - \text{MSE} + \text{CS}$        |
+| $\lambda_{X+2}$ | $\lambda_C - \text{MSE} + 2 * \text{CS}$    |
+| $\lambda_{X+3}$ | $\lambda_C - \text{MSE} + 3 * \text{CS}$    |
+| $\lambda_{X+4}$ | $\lambda_C - \text{MSE} + 4 * \text{CS}$    |
+| $\lambda_{X+5}$ | $\lambda_C - \text{MSE} + 5 * \text{CS}$    |
+| $\lambda_{X+6}$ | $\lambda_C - \text{MSE} + 6 * \text{CS}$    |
+| $\lambda_{X+7}$ | $\lambda_C - \text{MSE} + 7 * \text{CS}$    |
+| S               | Receiver sensitivity + optical path penalty |
+| X               | S + 4 dB (Note 1)                           |
+| $\lambda_{Y1}$  |                                             |
+| $\lambda_{Y2}$  |                                             |
+| $\lambda_{Y3}$  |                                             |
+| $\lambda_{Y4}$  |                                             |
+| $\lambda_{Y5}$  |                                             |
+| $\lambda_{Y6}$  |                                             |
+| $\lambda_{Y7}$  |                                             |
+| $\lambda_{Y8}$  |                                             |
+| Y               | S + 6 dB (Note 2)                           |
+| $\lambda_{Z1}$  |                                             |
+| $\lambda_{Z2}$  |                                             |
+| $\lambda_{Z3}$  |                                             |
+| $\lambda_{Z4}$  |                                             |
+| $\lambda_{Z5}$  |                                             |
+| $\lambda_{Z6}$  |                                             |
+| $\lambda_{Z7}$  |                                             |
+| $\lambda_{Z8}$  |                                             |
+
+**Table 10-1 – TWDM PON downstream (ONU receive)  
+X/S parameters**
+
+| Parameter                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          | Value                                                         |
+|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------|
+| Z                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  | 2.48832 Gbit/s: S + 7 dB (Note 3)<br>9.95328 Gbit/s: S + 8 dB |
+| NOTE 1 – 4 dB is the worst-case OLT transmitter power differential.<br>NOTE 2 – 7 dB is the maximum PtP WDM ONU transmitter power (+9 dBm) less the ORL (32 dB) less the TWDM OLT receiver sensitivity (–30 dBm).<br>NOTE 3 – The 2.48832 Gbit/s value (7 dB) is the maximum PtP WDM to TWDM OLT transmitter power differential for a 2.5G TWDM downstream link. The 9.95328 Gbit/s value (8 dB) is the maximum PtP WDM to TWDM OLT transmitter power differential for a 10G TWDM downstream link. |                                                               |
+
+#### 10.2.2 Narrowband OLT X/S tolerance mask
+
+The parameters of the OLT X/S mask are given in Table 10-2. Note that for the TWDM PON upstream, the PtP WDM channels are located so far away in wavelength that they are assumed to be filtered effectively by the TWDM PON diplexer.
+
+**Table 10-2 – TWDM PON upstream (OLT receive) X/S parameters**
+
+| Parameter                                                                                                                      | Value                                        |
+|--------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------|
+| $\lambda_{X-7}$                                                                                                                | $\lambda_C + \text{MSE} - 7 \cdot \text{CS}$ |
+| $\lambda_{X-6}$                                                                                                                | $\lambda_C + \text{MSE} - 6 \cdot \text{CS}$ |
+| $\lambda_{X-5}$                                                                                                                | $\lambda_C + \text{MSE} - 5 \cdot \text{CS}$ |
+| $\lambda_{X-4}$                                                                                                                | $\lambda_C + \text{MSE} - 4 \cdot \text{CS}$ |
+| $\lambda_{X-3}$                                                                                                                | $\lambda_C + \text{MSE} - 3 \cdot \text{CS}$ |
+| $\lambda_{X-2}$                                                                                                                | $\lambda_C + \text{MSE} - 2 \cdot \text{CS}$ |
+| $\lambda_{X-1}$                                                                                                                | $\lambda_C + \text{MSE} - \text{CS}$         |
+| $\lambda_{S-}$                                                                                                                 | $\lambda_C - \text{MSE}$                     |
+| $\lambda_C$                                                                                                                    | Central frequency of OLT filter              |
+| $\lambda_{S+}$                                                                                                                 | $\lambda_C + \text{MSE}$                     |
+| $\lambda_{X+1}$                                                                                                                | $\lambda_C - \text{MSE} + \text{CS}$         |
+| $\lambda_{X+2}$                                                                                                                | $\lambda_C - \text{MSE} + 2 \cdot \text{CS}$ |
+| $\lambda_{X+3}$                                                                                                                | $\lambda_C - \text{MSE} + 3 \cdot \text{CS}$ |
+| $\lambda_{X+4}$                                                                                                                | $\lambda_C - \text{MSE} + 4 \cdot \text{CS}$ |
+| $\lambda_{X+5}$                                                                                                                | $\lambda_C - \text{MSE} + 5 \cdot \text{CS}$ |
+| $\lambda_{X+6}$                                                                                                                | $\lambda_C - \text{MSE} + 6 \cdot \text{CS}$ |
+| $\lambda_{X+7}$                                                                                                                | $\lambda_C - \text{MSE} + 7 \cdot \text{CS}$ |
+| S                                                                                                                              | Receiver sensitivity + optical path penalty  |
+| X                                                                                                                              | S + 20 dB (Note)                             |
+| NOTE – 20 dB is the worst-case TWDM ONU transmitter power differential (5 dB) plus the differential optical path loss (15 dB). |                                              |
+
+The narrowband X/S tolerance of PtP WDM PON can be derived by analogy with the TWDM PON X/S tolerance above.
+
+# 11 TWDM PON PMD layer requirements
+
+### 11.1 PMD layer requirements
+
+The TWDM PON system must support a minimum of four TWDM channels. It may also support an optional extension up to eight TWDM channels.
+
+All parameters are specified as follows, and are in accordance with Tables 11-4 to 11-7.
+
+All parameter values specified are met under the worst-case operating conditions such as temperature and humidity, and include ageing effects, as specified in [ITU-T G.989.1]. The parameters are specified relative to a BER Reference level not worse than the values specified in Tables 11-4 to 11-7, for the worst-case optical path loss (see Table 6-1) and fibre chromatic dispersion.
+
+#### 11.1.1 Nominal Line rate and clock accuracy
+
+The transmission line rate is a multiple of 8 kHz.
+
+Parameters to be specified are categorized by downstream and upstream nominal line rates and downstream/upstream rate combinations as shown in Table 11-1. Each TWDM channel in the channel group on a TWDM PON can use any of the line rate options specified in Table 11-1.
+
+**Table 11-1 – Relation between TWDM PON line rate options and optical parameter tables**
+
+|               | Nominal line rate,<br>downstream/upstream (Gbit/s) | Reference table,<br>downstream/upstream |
+|---------------|----------------------------------------------------|-----------------------------------------|
+| Basic rate    | 9.95328/2.48832                                    | Table 11-5/Table 11-6                   |
+| Rate option 1 | 9.95328/9.95328                                    | Table 11-5/Table 11-7                   |
+| Rate option 2 | 2.48832/2.48832                                    | Table 11-4/Table 11-6                   |
+
+##### 11.1.1.1 Downstream clock accuracy
+
+When the OLT and the end office (the facility of the OLT and synchronization source) are in their normal operating state, the OLT is typically traceable to a Stratum-1 reference (accuracy of  $1 \times 10^{-11}$ ). When the OLT is in its free running mode, the accuracy of the downstream signal is at least that of a Stratum-4 clock ( $3.2 \times 10^{-5}$ ). OLTs intended for timing-critical applications such as mobile backhaul may require Stratum-3 quality in free-running mode.
+
+NOTE – The OLT may derive its timing from either a dedicated timing signal source or from a synchronous data interface (line timing). A packet-based timing source may also be used.
+
+##### 11.1.1.2 Upstream clock accuracy
+
+When in one of its operating states and granted an allocation, the ONU transmits its signal with frequency accuracy equal to that of the received downstream signal.
+
+#### 11.1.2 Line code
+
+The convention used for optical logic levels is:
+
+- high level of light emission for a binary ONE;
+- low level of light emission for a binary ZERO.
+
+##### 11.1.2.1 Downstream
+
+Downstream line coding for 9.95328 Gbit/s: scrambled NRZ.
+
+Downstream line coding for 2.48832 Gbit/s: scrambled NRZ.
+
+In addition to the schemes described in Appendix VI, two line code schemes are described in Appendix IX that are intended to offer mitigation of Raman crosstalk impairments on RF video overlay.
+
+##### 11.1.2.2 Upstream
+
+Upstream line coding for 2.48832 Gbit/s: scrambled NRZ.
+
+Upstream line coding for 9.95328 Gbit/s: scrambled NRZ for 20 km reach.
+
+Upstream line coding for 9.95328 Gbit/s: scrambled NRZ for 40 km reach. Other coding schemes for 40 km may be considered and could result in lower OPPs with alternative transmitter technologies. These other coding schemes are for further study.
+
+##### 11.1.2.3 Electronic dispersion compensation
+
+Electronic dispersion compensation (EDC) may be used in the OLT (ONU) transmitter to achieve the OPP specified in the optical interface parameter tables. At the ONU (OLT) receiver, EDC may also be used. The use of EDC is outside the scope of this Recommendation.
+
+#### 11.1.3 Operating wavelength
+
+The operating wavelength bands for TWDM PON are specified in clause 9.2.
+
+The downstream frequency is described in Table 11-2.
+
+**Table 11-2 – TWDM channel downstream frequency plan**
+
+| Channel | Central frequency (THz) | Wavelength (nm) |
+|---------|-------------------------|-----------------|
+| 1       | 187.8                   | 1596.34         |
+| 2       | 187.7                   | 1597.19         |
+| 3       | 187.6                   | 1598.04         |
+| 4       | 187.5                   | 1598.89         |
+| 5       | 187.4                   | 1599.75         |
+| 6       | 187.3                   | 1600.60         |
+| 7       | 187.2                   | 1601.46         |
+| 8       | 187.1                   | 1602.31         |
+
+NOTE – Channels 1-4 are assigned to TWDM with four downstream wavelengths. Channels 5-8 are optionally assigned to TWDM and may be used by PtP WDM or other systems if not reserved for TWDM expansion.
+
+The frequency values in this table are normative, while the wavelength values are for information only.
+
+#### 11.1.4 PMD parameters
+
+##### 11.1.4.1 Compatible optical distribution network
+
+TWDM PON operates over an ODN whose parameters are described by Table 11-3.
+
+**Table 11-3 – Physical parameters of a simple ODN**
+
+| Item                                                                                      | Unit | Specification                |
+|-------------------------------------------------------------------------------------------|------|------------------------------|
+| Fibre type (Note 1)                                                                       | –    | [ITU-T G.652], or compatible |
+| Attenuation range (as defined in clause 9.3.5.1)                                          | dB   | See Table 6-1                |
+| Maximum fibre distance between S/R-CG and R/S points (as specified in Table 6-2) (Note 2) | km   | DD20: 20<br>DD40: 40         |
+| Minimum fibre distance between S/R-CG and R/S points (as specified in Table 6-2)          | km   | 0                            |
+| Maximum differential optical path loss                                                    | dB   | 15                           |
+| Bidirectional transmission                                                                | –    | 1-fibre WDM                  |
+| Maintenance wavelength                                                                    | nm   | See [ITU-T L.313]            |
+| NOTE 1 – See clause 9.3.1.1.                                                              |      |                              |
+| NOTE 2 – Support of 60 km fibre distance may require reach extenders (REs).               |      |                              |
+
+##### **11.1.4.2 Optical interface parameters of downstream direction**
+
+The following downstream optical interface tables are applicable for 20 km and 40 km fibre length and 1 to 8 TWDM channels.
+
+**Table 11-4 – Optical interface parameters of 2.48832 Gbit/s downstream direction**
+
+| Item                                                                           | Unit            | Value                        |      |      |      |
+|--------------------------------------------------------------------------------|-----------------|------------------------------|------|------|------|
+| <b>OLT transmitter (optical interface S)</b>                                   |                 |                              |      |      |      |
+| Nominal line rate                                                              | Gbit/s          | 2.48832 (Note 1)             |      |      |      |
+| Operating wavelength band                                                      | nm              | 1596-1603                    |      |      |      |
+| Operating central frequency                                                    | THz             | Table 11-2                   |      |      |      |
+| Operating channel spacing                                                      | GHz             | 100 (Note 2)                 |      |      |      |
+| Maximum spectral excursion                                                     | GHz             | +/-20                        |      |      |      |
+| Line code                                                                      | –               | Scrambled NRZ (Note 1)       |      |      |      |
+| Mask of the transmitter eye diagram                                            | –               | See clause 11.1.5.3          |      |      |      |
+| Maximum reflectance of equipment at S/R-CG, measured at transmitter wavelength | dB              | NA                           |      |      |      |
+| Minimum ORL of ODN at S/R-CG                                                   | dB              | 32                           |      |      |      |
+| ODN class                                                                      |                 | N1                           | N2   | E1   | E2   |
+| Mean channel launch power minimum (at S/R-CG)                                  | dBm             | +0.0                         | +2.0 | +4.0 | +6.0 |
+| Mean channel launch power maximum (at S/R-CG)                                  | dBm             | +4.0                         | +6.0 | +8.0 | +10  |
+| Maximum downstream WNE-PSD                                                     | dBm<br>(15 GHz) | -63.5                        |      |      |      |
+| Minimum extinction ratio (Note 3)                                              | dB              | 8.2                          |      |      |      |
+| Tolerance to reflected optical power                                           | dB              | -15                          |      |      |      |
+| Dispersion range                                                               | ps/nm           | 0-420 (DD20)<br>0-840 (DD40) |      |      |      |
+
+**Table 11-4 – Optical interface parameters of 2.48832 Gbit/s downstream direction**
+
+| Item                                                                                                                                                                                                                                                      | Unit         | Value                 |       |       |       |  |  |  |  |
+|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------|-----------------------|-------|-------|-------|--|--|--|--|
+| Minimum side mode suppression ratio (at S/R-CP)                                                                                                                                                                                                           | dB           | 30                    |       |       |       |  |  |  |  |
+| Maximum downstream per channel out-of-band optical PSD (Note 4)                                                                                                                                                                                           | dBm (15 GHz) | -44.9 (4 channels)    |       |       |       |  |  |  |  |
+|                                                                                                                                                                                                                                                           |              | -52.1 (8 channels)    |       |       |       |  |  |  |  |
+| Maximum downstream per channel out-of-channel optical PSD (Note 5)                                                                                                                                                                                        | dBm (15 GHz) | -34.5 (4 channels)    |       |       |       |  |  |  |  |
+|                                                                                                                                                                                                                                                           |              | -42.4 (8 channels)    |       |       |       |  |  |  |  |
+| Jitter generation                                                                                                                                                                                                                                         | –            | See clause 11.1.5.4.3 |       |       |       |  |  |  |  |
+| <b>ONU receiver (optical interface R)</b>                                                                                                                                                                                                                 |              |                       |       |       |       |  |  |  |  |
+| Maximum OPP (Note 6)                                                                                                                                                                                                                                      | dB           | 1.0                   |       |       |       |  |  |  |  |
+| Maximum reflectance of equipment at R/S, measured at receiver wavelength                                                                                                                                                                                  | dB           | -20                   |       |       |       |  |  |  |  |
+| Bit error ratio reference level                                                                                                                                                                                                                           | –            | $10^{-4}$ (Note 7)    |       |       |       |  |  |  |  |
+| Rx wavelength channel tuning time                                                                                                                                                                                                                         |              | See Table 9-2         |       |       |       |  |  |  |  |
+| Maximum tuning granularity                                                                                                                                                                                                                                | GHz          | 5                     |       |       |       |  |  |  |  |
+| ODN class                                                                                                                                                                                                                                                 |              | N1                    | N2    | E1    | E2    |  |  |  |  |
+| Sensitivity (at R/S)                                                                                                                                                                                                                                      | dBm          | -30.0                 | -30.0 | -30.0 | -30.0 |  |  |  |  |
+| Overload (at R/S)                                                                                                                                                                                                                                         | dBm          | -10.0                 | -10.0 | -10.0 | -10.0 |  |  |  |  |
+| In-band crosstalk tolerance                                                                                                                                                                                                                               | dB (15 GHz)  | 32.3                  |       |       |       |  |  |  |  |
+| Consecutive identical digit immunity                                                                                                                                                                                                                      | bit          | 72                    |       |       |       |  |  |  |  |
+| Jitter tolerance                                                                                                                                                                                                                                          | –            | See clause 11.1.5.4.2 |       |       |       |  |  |  |  |
+| NOTE 1 – Two additional line codes that have been developed to facilitate support of the RF Video Overlay are covered in Appendix IX.                                                                                                                     |              |                       |       |       |       |  |  |  |  |
+| NOTE 2 – Minor deviations from the nominal 100 GHz spacing are allowed in order to accommodate a combined wavelength mux/demux device, see Table 11-2.                                                                                                    |              |                       |       |       |       |  |  |  |  |
+| NOTE 3 – A lower extinction ratio is allowed but must be compensated by a larger transmitter launch power within the limits of the "Mean launch power maximum" value. However, the impact of reduced ER on OOB/OOC power must be considered.              |              |                       |       |       |       |  |  |  |  |
+| NOTE 4 – This value is based on the following assumptions: OOB impact from TWDM PON on PtP WDM PON can be controlled through appropriate filtering, 0.1 dB penalty, PtP WDM PON operates without FEC, and 4 or 8 interfering TWDM channels, respectively. |              |                       |       |       |       |  |  |  |  |
+| NOTE 5 – This value is based on the following assumptions: OOC in downstream can be controlled through filtering from WM, 0.1 dB penalty, TWDM PON operates with FEC, and 4 or 8 TWDM channels (three or seven interferers), respectively.                |              |                       |       |       |       |  |  |  |  |
+| NOTE 6 – The specified OPP is valid up to a 40 km optical link distance. If the actual OPP is worse than the specified value, it must be compensated by the transmitter launch power increase up to the limits of the Mean launch power maximum.          |              |                       |       |       |       |  |  |  |  |
+| NOTE 7 – See clause 9.4.1 of [b-ITU-T G.Sup39] for additional details.                                                                                                                                                                                    |              |                       |       |       |       |  |  |  |  |
+| NOTE 8 – The definition of In-band crosstalk tolerance and its implication on receiver sensitivity is defined in clause 3.2.2.10 of [ITU-T G.989].                                                                                                        |              |                       |       |       |       |  |  |  |  |
+
+**Table 11-5 – Optical interface parameters of 9.95328 Gbit/s downstream direction**
+
+| Item                                                                           | Unit            | Value                        |       |       |       |
+|--------------------------------------------------------------------------------|-----------------|------------------------------|-------|-------|-------|
+| <b>OLT transmitter (optical interface S)</b>                                   |                 |                              |       |       |       |
+| Nominal line rate                                                              | Gbit/s          | 9.95328 (Note 1)             |       |       |       |
+| Operating wavelength band                                                      | nm              | 1596-1603                    |       |       |       |
+| Operating central frequency                                                    | THz             | Table 11-2                   |       |       |       |
+| Operating channel spacing                                                      | GHz             | 100 (Note 2)                 |       |       |       |
+| Maximum spectral excursion                                                     | GHz             | +/-20                        |       |       |       |
+| Line code                                                                      | –               | Scrambled NRZ (Note 1)       |       |       |       |
+| Mask of the transmitter eye diagram                                            | –               | See clause 11.1.5.3          |       |       |       |
+| Maximum reflectance of equipment at S/R-CG, measured at transmitter wavelength | dB              | NA                           |       |       |       |
+| Minimum ORL of ODN at S/R-CG                                                   | dB              | 32                           |       |       |       |
+| ODN Class                                                                      |                 | N1                           | N2    | E1    | E2    |
+| Mean channel launch power minimum (at S/R-CG)                                  | dBm             | +3.0                         | +5.0  | +7.0  | +9.0  |
+| Mean channel launch power maximum (at S/R-CG)                                  | dBm             | +7.0                         | +9.0  | +11.0 | +11.0 |
+| Maximum downstream WNE-PSD                                                     | dBm<br>(15 GHz) | -63.7                        |       |       |       |
+| Minimum extinction ratio (Note 3)                                              | dB              | 8.2                          |       |       |       |
+| Tolerance to reflected optical power                                           | dB              | -15                          |       |       |       |
+| Dispersion range                                                               | ps/nm           | 0-420 (DD20)<br>0-840 (DD40) |       |       |       |
+| Minimum side mode suppression ratio (at S/R-CP)                                | dB              | 30                           |       |       |       |
+| Maximum downstream per channel out-of-band optical PSD (Note 4)                | dBm<br>(15 GHz) | -44.9 (4 channels)           |       |       |       |
+|                                                                                |                 | -52.1 (8 channels)           |       |       |       |
+| Maximum downstream per channel out-of-channel optical PSD (Note 5)             | dBm<br>(15 GHz) | -34.5 (4 channels)           |       |       |       |
+|                                                                                |                 | -42.4 (8 channels)           |       |       |       |
+| Jitter generation                                                              | –               | See clause 11.1.5.4.3        |       |       |       |
+| <b>ONU receiver (optical interface R)</b>                                      |                 |                              |       |       |       |
+| Maximum OPP (Note 6)                                                           | dB              | 2.0                          |       |       |       |
+| Maximum reflectance of equipment at R/S, measured at receiver wavelength       | dB              | -20                          |       |       |       |
+| Bit error ratio reference level                                                | –               | $10^{-3}$ (Note 7)           |       |       |       |
+| Rx wavelength channel tuning time                                              |                 | See Table 9-2                |       |       |       |
+| Maximum tuning granularity                                                     | GHz             | 5                            |       |       |       |
+| ODN Class                                                                      |                 | N1                           | N2    | E1    | E2    |
+| Sensitivity (at R/S)                                                           | dBm             | -28.0                        | -28.0 | -28.0 | -28.0 |
+| Overload (at R/S)                                                              | dBm             | -7.0                         | -7.0  | -7.0  | -9.0  |
+| In-band crosstalk tolerance                                                    | dB              | 35.3                         |       |       |       |
+
+**Table 11-5 – Optical interface parameters of 9.95328 Gbit/s downstream direction**
+
+| Item                                 | Unit     | Value                 |
+|--------------------------------------|----------|-----------------------|
+|                                      | (15 GHz) |                       |
+| Consecutive identical digit immunity | bit      | 72                    |
+| Jitter tolerance                     | –        | See clause 11.1.5.4.2 |
+
+NOTE 1 – Two additional line codes that have been developed to facilitate support of the RF video overlay are covered in Appendix IX.
+
+NOTE 2 – Minor deviations from the nominal 100 GHz spacing are allowed in order to accommodate a combined wavelength mux/demux, see Table 11-2.
+
+NOTE 3 – A lower extinction ratio is allowed but must be compensated by a larger transmitter launch power within the limits of the "Mean launch power maximum" value. However, the impact of reduced ER on OOB/OOC power must be considered.
+
+NOTE 4 – This value is based on the following assumptions: OOB impact from TWDM PON on PtP WDM PON can be controlled through appropriate filtering, 0.1 dB penalty, PtP WDM PON operates without FEC, and 4 or 8 interfering TWDM channels, respectively.
+
+NOTE 5 – This value is based on the following assumptions: OOC in downstream can be controlled through filtering from WM, 0.1 dB penalty, TWDM PON operates with FEC, and 4 or 8 TWDM channels (three or seven interferers), respectively.
+
+NOTE 6 – The specified OPP is valid up to a 40 km optical link distance. If the actual OPP is worse than the specified value, it must be compensated by the transmitter launch power increase up to the limits of the Mean launch power maximum.
+
+NOTE 7 – See clause 9.4.1 of [b-ITU-T G.Sup39], for additional details.
+
+NOTE 8 – The definition of In-band crosstalk tolerance and its implication on receiver sensitivity is defined in clause 3.2.2.10 of [ITU-T G.989].
+
+##### 11.1.4.3 Optical interface parameters of upstream direction
+
+The following upstream optical interface parameter tables are applicable to 20 and 40 km fibre length, and 1 to 8 TWDM channels.
+
+**Table 11-6 – Optical interface parameters of 2.48832 Gbit/s upstream direction**
+
+| Item                                                                                                   | Unit   | Value                                                                                              |
+|--------------------------------------------------------------------------------------------------------|--------|----------------------------------------------------------------------------------------------------|
+| <b>ONU transmitter (optical interface S)</b>                                                           |        |                                                                                                    |
+| Nominal line rate                                                                                      | Gbit/s | 2.48832                                                                                            |
+| Operating wavelength band                                                                              | nm     | 1524-1544 (wide band option),<br>1528-1540 (reduced band option)<br>1532-1540 (narrow band option) |
+| Minimum operating channel spacing                                                                      | GHz    | 50                                                                                                 |
+| Maximum operating channel spacing                                                                      | GHz    | 200                                                                                                |
+| Maximum spectral excursion<br>(over 1 OLT-ONU tuning cycle) (Note 1)                                   | GHz    | +/-12.5 (for 50 GHz CS)<br>+/-20 (for 100 GHz CS)<br>+/-25 (for 200 GHz CS)                        |
+| Transmitter power wavelength dependency<br>(Note 13)                                                   | dB     | +/-0.05 dB/GHz                                                                                     |
+| Minimum tuning window (Note 2)<br>When using cyclic channel grid<br>When not using cyclic channel grid | GHz    | (N+1)*CS<br>(N-1)*CS+2*MSE                                                                         |
+
+**Table 11-6 – Optical interface parameters of 2.48832 Gbit/s upstream direction**
+
+| Item                                                                                  | Unit            | Value                                                              |    |    |    |
+|---------------------------------------------------------------------------------------|-----------------|--------------------------------------------------------------------|----|----|----|
+| Maximum tuning granularity                                                            | GHz             | CS/20                                                              |    |    |    |
+| Tx wavelength channel tuning time                                                     |                 | See Table 9-2                                                      |    |    |    |
+| Line code                                                                             | –               | Scrambled NRZ                                                      |    |    |    |
+| Mask of the transmitter eye diagram                                                   | –               | See clause 11.1.5.3.2                                              |    |    |    |
+| Maximum reflectance of equipment at R/S, measured at transmitter wavelength (Note 19) | dB              | –32                                                                |    |    |    |
+| Minimum ORL of ODN at R/S                                                             | dB              | 32                                                                 |    |    |    |
+| ODN Class                                                                             |                 | N1                                                                 | N2 | E1 | E2 |
+| Mean channel launch power minimum (at R/S)                                            |                 |                                                                    |    |    |    |
+| – Type A link (Note 3)                                                                | dBm             | +4                                                                 | +4 | +4 | +4 |
+| – Type B link (Note 4)                                                                | dBm             | 0                                                                  | 0  | 0  | 0  |
+| Mean channel launch power maximum (at R/S) (Note 14)                                  |                 |                                                                    |    |    |    |
+| – Type A link (Note 3)                                                                | dBm             | +9                                                                 | +9 | +9 | +9 |
+| – Type B link (Note 4)                                                                | dBm             | +5                                                                 | +5 | +5 | +5 |
+| Maximum Tx enable transient time                                                      | bits            | 320<br>(128.6)                                                     |    |    |    |
+| Maximum Tx disable transient time                                                     | bits            | 320<br>(128.6)                                                     |    |    |    |
+| Minimum extinction ratio (Note 5)                                                     | dB              | 8.2                                                                |    |    |    |
+| Tolerance to reflected optical power                                                  | dB              | –15                                                                |    |    |    |
+| Dispersion range                                                                      | ps/nm           | 0 to 355 (DD20)<br>0 to 710 (DD40)                                 |    |    |    |
+| Minimum side mode suppression ratio (Note 6)                                          | dB              | 30                                                                 |    |    |    |
+| Maximum upstream out-of-band optical PSD (Note 7)                                     | dBm<br>(15GHz)  | –57.4 (4 channels)                                                 |    |    |    |
+|                                                                                       |                 | –64.6 (8 channels)                                                 |    |    |    |
+| Maximum upstream out-of-channel optical PSD – OOC1 (Note 8)                           | dBm<br>(15 GHz) | –36.7 for 50GHz CS<br>–40.5 for 100 GHz CS<br>–44.4 for 200 GHz CS |    |    |    |
+| Maximum upstream out-of-channel optical PSD – OOC2 (Note 8)                           | dBm<br>(15 GHz) | –41.6 (4 channels)                                                 |    |    |    |
+|                                                                                       |                 | –48.8 (8 channels)                                                 |    |    |    |
+| Maximum upstream WNE-PSD (Note 9)                                                     | dBm<br>(15 GHz) | –62.6                                                              |    |    |    |
+| Jitter transfer                                                                       | –               | See clause 11.1.5.4.1                                              |    |    |    |
+| Jitter generation                                                                     | –               | See clause 11.1.5.4.3                                              |    |    |    |
+
+**Table 11-6 – Optical interface parameters of 2.48832 Gbit/s upstream direction**
+
+| Item                                                                        | Unit     | Value                 |      |       |       |
+|-----------------------------------------------------------------------------|----------|-----------------------|------|-------|-------|
+| <b>OLT receiver (optical interface R)</b>                                   |          |                       |      |       |       |
+| ODN class                                                                   |          | N1                    | N2   | E1    | E2    |
+| Maximum OPP (Note 10)                                                       | dB       |                       |      |       |       |
+| – with Raman effects (DD20, 4 channel) (Note 15)                            |          | 1.0                   | 1.0  | 1.5   | 1.5   |
+| – with Raman effects (DD40, 4 channel)                                      |          | 1.4                   | 1.6  | 1.9   | 1.9   |
+| – with Raman effects (DD20, 8 channel)                                      |          | 1.0                   | 1.3  | 1.8   | 1.8   |
+| – with Raman effects (DD40, 8 channel)                                      |          | 1.7                   | 2.1  | 2.8   | 2.8   |
+| Maximum OPP excluding Raman (Note 17)                                       | dB       |                       |      |       |       |
+| – DD20                                                                      |          | 0.5                   |      |       |       |
+| – DD40                                                                      |          | 1.0                   |      |       |       |
+| Maximum reflectance of equipment at S/R-CG, measured at receiver wavelength | dB       | –20                   |      |       |       |
+| Bit error ratio reference level                                             | –        | $10^{-4}$ (Note 11)   |      |       |       |
+| ODN class                                                                   |          | N1                    | N2   | E1    | E2    |
+| Sensitivity (at S/R-CG, based on DD20, 4 channel) (Note 12)                 |          |                       |      |       |       |
+| – Type A link (Note 3)                                                      | dBm      | –26                   | –28  | –30.5 | –32.5 |
+| – Type B link (Note 4)                                                      | dBm      | –30                   | –32  | –34.5 | –36.5 |
+| Overload (at S/R-CG)                                                        |          |                       |      |       |       |
+| – Type A link (Note 3)                                                      | dBm      | –5                    | –7   | –9    | –11   |
+| – Type B link (Note 4)                                                      | dBm      | –9                    | –11  | –13   | –15   |
+| In-band crosstalk tolerance (Type A) (Note 18)                              | dB       | 26.0                  | 26.0 | 25.1  | 24.1  |
+| (Type B)                                                                    | (15 GHz) | 22.0                  | 22.0 | 21.1  | 20.1  |
+| Consecutive identical digit immunity                                        | bit      | 72                    |      |       |       |
+| Jitter tolerance                                                            | –        | See clause 11.1.5.4.2 |      |       |       |
+
+NOTE 1 – MSE values of other CS can be interpolated from the three given values.  
+NOTE 2 – N is the channel count. When using cyclic channel grid, if CS is 100 GHz, the minimum tuning windows are 500 GHz and 900 GHz for four and eight channel TWDM PONs, respectively. When using cyclic channel grid, if CS is 50 GHz, the minimum tuning windows are 250 GHz and 450 GHz for four and eight channel TWDM PONs, respectively. When not using cyclic channel grid, if CS is 100 GHz, its minimum tuning windows are 340 GHz and 740 GHz for four and eight channel TWDM PONs, respectively. When not using cyclic channel grid, if CS is 50 GHz, the minimum tuning windows are 175 GHz and 375 GHz for 4 and 8 channel TWDM PONs, respectively.  
+NOTE 3 – Type A link values assume an unamplified OLT receiver. However, an amplified OLT receiver is not precluded.  
+NOTE 4 – Type B link values assume an amplified OLT receiver with the amplifier at the S/R-CG reference point. However, other amplifier approaches, including an unamplified OLT receiver are not precluded.  
+NOTE 5 – A lower extinction ratio is allowed but must be compensated by a larger transmitter launch power within the limits of the "Mean launch power maximum" value. However, the impact of reduced ER on OOB/OOC power must be considered.  
+NOTE 6 – SMSR is measured on the laser output, before any filtering. This prevents a significant mode partition noise penalty. Other limitations on OOB and OOC PSD still apply to the R/S reference point.
+
+**Table 11-6 – Optical interface parameters of 2.48832 Gbit/s upstream direction**
+
+| Item                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   | Unit | Value |
+|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------|-------|
+| NOTE 7 – This value is based on the following assumptions: OOB impact from TWDM PON on PtP WDM PON can be controlled through appropriate filtering, 0.1 dB penalty, PtP WDM PON operates without FEC, and four or eight interfering TWDM channels, respectively.<br>NOTE 8 – See OOC-PSD mask in clause 9.3.9. These values are based on the following assumptions: 1 dB US OOC penalty, TWDM PON operates with FEC, and four or eight TWDM channels (three or seven interferers), respectively. In some implementations, this requirement may be achieved by more tightly regulating the Tx output power (lowering the maximum level while maintaining the minimum level).<br>NOTE 9 – This value is based on the following assumptions: 0.1 dB penalty, TWDM PON operates with FEC, and 64 TWDM PON ONUs in one channel (63 interferers).<br>NOTE 10 – The specified penalty takes into account the class-specific Tx power, distance, and number of wavelengths. The maximum OPP values assume no SR-/CG located splitters and low optical fibre loss, resulting in the worst case Raman effect. ODNs that include high loss elements near the OLT or higher loss optical cable will exhibit lower penalties.<br>NOTE 11 – See clause 9.4.1 of [b-ITU-T G.Sup39] for additional details.<br>NOTE 12 – See clause 11.1.4.3.1 for an approach to accommodate the case of 40 km and 8 wavelengths.<br>NOTE 13 – This parameter is applicable for ONU transmitters that require OLT interaction to tune the transmitting wavelength.<br>NOTE 14 – An optical power levelling mechanism can be applied to the ONU in order to help meet the OOB/OOC PSD and OLT Rx overload parameters. The concept of optical power levelling is described in Annex D.<br>NOTE 15 – The 4 channel, DD20 values are rounded up from those actually calculated.<br>NOTE 16 – The definition of In-band crosstalk tolerance and its implication on receiver sensitivity is defined in clause 3.2.2.10 of [ITU-T G.989].<br>NOTE 17 – If the actual OPP is worse than the specified value, it must be compensated by increasing the transmitter mean launch power minimum specification by X dB for each X dB of extra OPP allowance, where $X < 1.5$ dB, while meeting <u>all</u> other Tx specifications. High penalty operation poses some risks, and PMD interoperability testing should be employed to measure the actual OPP with a receiver subject to in-band crosstalk as specified elsewhere in this table. To avoid system operation in very high penalty regimes, this note is only applicable to the DD20 fibre distance class.<br>NOTE 18 – These values vary for each budget class based on the worst case combination of PtP WDM PON OOB, TWDM PON OOC, TWDM PON WNE-PSD and TWDM PON upstream ONU echoes (accounting for the maximum ODN split that can be obtained in each optical path loss class).<br>NOTE 19 – This value is based on the following assumptions: consideration of multiple upstream ONU echoes and penalties of 0.4 dB (for N1) up to 0.8 dB (for E2). |      |       |
+
+**Table 11-7 – Optical interface parameters of 9.95328 Gbit/s upstream direction**
+
+| Item                                         | Unit   | Value                                                                                              |
+|----------------------------------------------|--------|----------------------------------------------------------------------------------------------------|
+| <b>ONU transmitter (optical interface S)</b> |        |                                                                                                    |
+| Nominal line rate                            | Gbit/s | 9.95328                                                                                            |
+| Operating wavelength band                    | nm     | 1524-1544 (wide band option),<br>1528-1540 (reduced band option)<br>1532-1540 (narrow band option) |
+| Minimum operating channel spacing            | GHz    | 50                                                                                                 |
+| Maximum operating channel spacing            | GHz    | 200                                                                                                |
+
+**Table 11-7 – Optical interface parameters of 9.95328 Gbit/s upstream direction**
+
+| Item                                                                                                   | Unit            | Value                                                                       |      |      |      |
+|--------------------------------------------------------------------------------------------------------|-----------------|-----------------------------------------------------------------------------|------|------|------|
+| Maximum spectral excursion (Note 1)<br>(over 1 OLT-ONU tuning cycle)                                   | GHz             | +/-12.5 (for 50 GHz CS)<br>+/-20 (for 100 GHz CS)<br>+/-25 (for 200 GHz CS) |      |      |      |
+| Transmitter power wavelength dependency<br>(Note 13)                                                   | dB              | +/-0.02 dB/GHz                                                              |      |      |      |
+| Minimum tuning window (Note 2)<br>When using cyclic channel grid<br>When not using cyclic channel grid | GHz             | (N+1)*CS<br>(N-1)*CS+2*MSE                                                  |      |      |      |
+| Maximum tuning granularity                                                                             | GHz             | CS/20                                                                       |      |      |      |
+| Tx wavelength channel tuning time                                                                      |                 | See Table 9-2                                                               |      |      |      |
+| Line code                                                                                              | –               | Scrambled NRZ (20 km)<br>Scrambled NRZ (40 km) (Note 15)                    |      |      |      |
+| Mask of the transmitter eye diagram                                                                    | –               | See clause 11.1.5.3.2                                                       |      |      |      |
+| Maximum reflectance of equipment at R/S,<br>measured at transmitter wavelength<br>(Note 20)            | dB              | -32                                                                         |      |      |      |
+| Minimum ORL of ODN at R/S                                                                              | dB              | 32                                                                          |      |      |      |
+| ODN Class                                                                                              |                 | N1                                                                          | N2   | E1   | E2   |
+| Mean channel launch power minimum<br>(at R/S)                                                          |                 |                                                                             |      |      |      |
+| – Type A link (Note 3)                                                                                 | dBm             | +4.0                                                                        | +4.0 | +4.0 | NA   |
+| – Type B link (Note 4)                                                                                 | dBm             | +2.0                                                                        | +2.0 | +2.0 | +4.0 |
+| Mean channel launch power maximum<br>(at R/S) (Note 14)                                                |                 |                                                                             |      |      |      |
+| – Type A link (Note 3)                                                                                 | dBm             | +9.0                                                                        | +9.0 | +9.0 | NA   |
+| – Type B link (Note 4)                                                                                 | dBm             | +7.0                                                                        | +7.0 | +7.0 | +9.0 |
+| Maximum Tx enable transient time                                                                       | Bits<br>(ns)    | 1280<br>(128.6)                                                             |      |      |      |
+| Maximum Tx disable transient time                                                                      | Bits<br>(ns)    | 1280<br>(128.6)                                                             |      |      |      |
+| Minimum extinction ratio (Note 5)                                                                      | dB              | 6.0                                                                         |      |      |      |
+| Tolerance to reflected optical power                                                                   | dB              | -15                                                                         |      |      |      |
+| Dispersion range                                                                                       | ps/nm           | 0 to 355 (DD20)                                                             |      |      |      |
+| Minimum side mode suppression ratio<br>(Note 6)                                                        | dB              | 30                                                                          |      |      |      |
+| Maximum upstream out-of-band optical PSD<br>(Note 7)                                                   | dBm<br>(15 GHz) | -57.4 (4 channels)<br>-64.6 (8 channels)                                    |      |      |      |
+| Maximum upstream out-of-channel optical<br>PSD – OOC1 (Note 8)                                         | dBm<br>(15 GHz) | -36.7 for 50GHz CS<br>-40.5 for 100 GHz CS<br>-44.4 for 200 GHz CS          |      |      |      |
+| Maximum upstream out-of-channel optical<br>PSD – OOC2 (Note 8)                                         | dBm<br>(15 GHz) | -41.6 (4 channels)<br>-48.5 (8 channels)                                    |      |      |      |
+
+**Table 11-7 – Optical interface parameters of 9.95328 Gbit/s upstream direction**
+
+| Item                                                                        | Unit            | Value                 |              |              |              |
+|-----------------------------------------------------------------------------|-----------------|-----------------------|--------------|--------------|--------------|
+| Maximum upstream WNE-PSD (Note 9)                                           | dBm<br>(15 GHz) | -62.6                 |              |              |              |
+| Jitter transfer                                                             | –               | See clause 11.1.5.4.1 |              |              |              |
+| Jitter generation                                                           | –               | See clause 11.1.5.4.3 |              |              |              |
+| <b>OLT receiver (optical interface R)</b>                                   |                 |                       |              |              |              |
+| ODN Class                                                                   |                 | N1                    | N2           | E1           | E2           |
+| Maximum OPP (Note 10, 15)                                                   | dB              |                       |              |              |              |
+| – with Raman effects (DD20, 4 channel) (Note 16)                            |                 | 1.0                   | 1.0          | 1.5          | 1.5          |
+| – with Raman effects (DD40, 4 channel)                                      |                 | 1.9                   | 2.1          | 2.4          | 2.4          |
+| – with Raman effects (DD20, 8 channel)                                      |                 | 1.0                   | 1.3          | 1.8          | 1.8          |
+| – with Raman effects (DD40, 8 channel)                                      |                 | 2.2                   | 2.6          | 3.3          | 3.3          |
+| Maximum OPP excluding Raman (Note 18)                                       | dB              |                       |              |              |              |
+| – DD20                                                                      |                 | 0.5                   |              |              |              |
+| – DD40                                                                      |                 | 1.5                   |              |              |              |
+| Maximum reflectance of equipment at S/R-CG, measured at receiver wavelength | dB              | Less than -20         |              |              |              |
+| Bit error ratio reference level                                             | –               | $10^{-3}$ (Note 11)   |              |              |              |
+| ODN Class                                                                   |                 | N1                    | N2           | E1           | E2           |
+| Sensitivity (at S/R-CG) , based on DD20, 4 channel) (Note 5 and Note 12)    |                 |                       |              |              |              |
+| – Type A link (Note 3)                                                      | dBm             | -26.0                 | -28.0        | -30.5        | NA           |
+| – Type B link (Note 4)                                                      | dBm             | -28.0                 | -30.0        | -32.5        | -32.5        |
+| Overload (at S/R-CG)                                                        |                 |                       |              |              |              |
+| – Type A link (Note 3)                                                      | dBm             | -5.0                  | -7.0         | -9.0         | NA           |
+| – Type B link (Note 4)                                                      | dBm             | -7.0                  | -9.0         | -11.0        | -11.0        |
+| In-band crosstalk tolerance (Type A) (Note 19) (Type B)                     | dB<br>(15 GHz)  | 26.0<br>24.0          | 26.0<br>24.0 | 25.1<br>23.1 | 24.1<br>22.1 |
+| Consecutive identical digit immunity                                        | bit             | 72                    |              |              |              |
+| Jitter tolerance                                                            | –               | See clause 11.1.5.4.2 |              |              |              |
+
+NOTE 1 – MSE values of other CS can be interpolated from the three given values.  
+NOTE 2 – N is the channel count. When using cyclic channel grid, if CS is 100 GHz, the minimum tuning windows are 500 GHz and 900 GHz for 4 and 8 channel TWDM PONs, respectively. When using cyclic channel grid, if CS is 50 GHz, the minimum tuning windows are 250 GHz and 450 GHz for four and eight channel TWDM PONs, respectively. When not using cyclic channel grid, if CS is 100 GHz, its minimum tuning windows are 340 GHz and 740 GHz for four and eight channel TWDM PONs, respectively. When not using cyclic channel grid, if CS is 50 GHz, the minimum tuning windows are 175 GHz and 375 GHz for 4 and 8 channel TWDM PONs, respectively.  
+NOTE 3 – Type A link values assume an unamplified OLT receiver. However, an amplified OLT receiver is not precluded.  
+NOTE 4 – Type B link values assume an amplified OLT receiver with the amplifier at the S/R-CG reference point. However, other amplifier approaches, including an unamplified OLT receiver are not
+
+**Table 11-7 – Optical interface parameters of 9.95328 Gbit/s upstream direction**
+
+| Item                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             | Unit | Value |
+|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------|-------|
+| <p>precluded.</p> <p>NOTE 5 – A lower extinction ratio is allowed but must be compensated by a larger transmitter launch power within the limits of the "Mean launch power maximum" value. However the impact of reduced ER on OOB/OOC power must be considered. A lower "Mean launch power minimum" is allowed but must be compensated by higher extinction ratio. For quantitative treatment of these tradeoffs, see clause 11.1.4.3.2.</p> <p>NOTE 6 – SMSR is measured on the laser output, before any filtering. This prevents a significant mode partition noise penalty. Other limitations on OOB and OOC PSD still apply to the R/S reference point.</p> <p>NOTE 7 – This value is based on the following assumptions: OOB impact from TWDM PON on PtP WDM PON can be controlled through appropriate filtering, 0.1 dB penalty, PtP WDM PON operates without FEC, and four or eight interfering TWDM channels, respectively.</p> <p>NOTE 8 – See OOC-PSD mask in clause 9.3.9. These values are based on the following assumptions: 1 dB US OOC penalty, TWDM PON operates with FEC, and four or eight TWDM channels (three or seven interferers), respectively. In some implementations, this requirement may be achieved by more tightly regulating the Tx output power (lowering the maximum level while maintaining the minimum level).</p> <p>NOTE 9 – This value is based on the following assumptions: 0.1 dB penalty, TWDM PON operates with FEC, and 64 TWDM PON ONUs in one channel (63 interferers).</p> <p>NOTE 10 – The specified penalty takes into account the class-specific Tx power, distance, and number of wavelengths. The maximum OPP values assume no SR-/CG located based splitters and low optical fibre loss, resulting in the worst case Raman effect. ODNs that include high loss elements near the OLT or higher loss optical cable will exhibit lower penalties.</p> <p>NOTE 11 – See clause 9.4.1 [b-ITU-T G.Sup39] for additional details.</p> <p>NOTE 12 – See clause 11.1.4.3.1 for an approach to accommodate the case of 40 km and eight wavelengths.</p> <p>NOTE 13 – This parameter is applicable for ONU transmitters that require OLT interaction to tune the transmitting wavelength.</p> <p>NOTE 14 – An optical power levelling mechanism can be applied to the ONU in order to help meet the OOB/OOC PSD and OLT Rx overload parameters. The concept of optical power levelling is described in Annex D.</p> <p>NOTE 15 – Scrambled NRZ is assumed for the OPP parameter values. Other coding schemes for 40 km may result in lower OPPs with alternative transmitter technologies. These other coding schemes are for further study.</p> <p>NOTE 16 – The 4 channel, DD20 values are rounded up from those actually calculated.</p> <p>NOTE 17 – The definition of In-band crosstalk tolerance and its implication on receiver sensitivity is defined in clause 3.2.2.10 of [ITU-T G.989].</p> <p>NOTE 18 – If the actual OPP is worse than the specified value, it must be compensated by increasing the transmitter mean launch power minimum specification by X dB for each X dB of extra OPP allowance, where <math>X &lt; 1.5</math> dB, while meeting <u>all</u> other Tx specifications. High penalty operation poses some risks, and PMD interoperability testing should be employed to measure the actual OPP with a receiver subject to in-band crosstalk as specified elsewhere in this table. To avoid system operation in very high penalty regimes, this note is only applicable to the DD20 fibre distance class.</p> <p>NOTE 19 – These values vary for each budget class based on the worst case combination of PtP WDM PON OOB, TWDM PON OOC, TWDM PON WNE-PSD and TWDM PON upstream ONU echoes (accounting for the maximum ODN split that can be obtained in each optical path loss class).</p> <p>NOTE 20 – This value is based on the following assumptions: consideration of multiple upstream ONU echoes and penalties of 0.4 dB (for N1) up to 0.8 dB (for E2).</p> |      |       |
+
+##### 11.1.4.3.1 Example of upstream OPP and receiver substitution
+
+The upstream tables specify the OLT receiver sensitivity for the base case of 20 km and four TWDM channels. As noted in the tables above, if a different application is used, then the OPPs will be different and potentially impact the optical link budget. The case of the 40 km and eight wavelengths can be accommodated by selecting the OLT receiver specified for the next available ODN class. For example, in Table 11-6, N2 class with 40 km and eight wavelengths needs an additional 1.5 dB of optical link budget. Selecting the E1 class OLT provides a 2.0 dB improvement and thereby meets the budget requirement.
+
+##### 11.1.4.3.2 Extinction ratio and minimum mean launch optical power trade off
+
+This clause is applicable to transmitters subject to the requirement of Table 11-7.
+
+![Figure 11-0: ONU transmitter power and ER admissible region. The graph plots Extinction ratio (ER) on the y-axis against Mean launch optical power (P-bar) on the x-axis. The y-axis has labels ER1, ER2, ER3, ER4.5. The x-axis has labels P-bar1, P-bar2, P-bar3, P-bar4, P-bar5. A piece-wise linear curve connects (P-bar1, ER1) to (P-bar2, ER2) to (P-bar3, ER3) to (P-bar4, ER4.5) to (P-bar5, ER4.5). The region above this curve and between P-bar1 and P-bar5 is shaded with horizontal lines. The region above the curve and to the right of P-bar5 is shaded with vertical lines. The region below the curve is unshaded.](5bf611979ab0126ebd219a1c6eda6b1e_img.jpg)
+
+Figure 11-0: ONU transmitter power and ER admissible region. The graph plots Extinction ratio (ER) on the y-axis against Mean launch optical power (P-bar) on the x-axis. The y-axis has labels ER1, ER2, ER3, ER4.5. The x-axis has labels P-bar1, P-bar2, P-bar3, P-bar4, P-bar5. A piece-wise linear curve connects (P-bar1, ER1) to (P-bar2, ER2) to (P-bar3, ER3) to (P-bar4, ER4.5) to (P-bar5, ER4.5). The region above this curve and between P-bar1 and P-bar5 is shaded with horizontal lines. The region above the curve and to the right of P-bar5 is shaded with vertical lines. The region below the curve is unshaded.
+
+G.989.2(14)-Amd.2(17)\_F11-0
+
+**Figure 11-0 – ONU transmitter power and ER admissible region, subject to Table 11-7 requirements**
+
+The parameters of the ONU transmitter jointly specified by its mean optical launch power  $\bar{P}$  and extinction ratio  $ER$  shall lie within an admissible region (shown as an overall shaded area in Figure 11-0) which is bounded in the mean launch power by the lines  $\bar{P} \geq \bar{P} \min = \bar{P}_1$  and  $\bar{P} \leq \bar{P} \max = \bar{P}_5$ , and in the extinction ratio, from below, by a piece-wise linear segment specified in Table 11-7bis for Type A transmitters and Table 11-7ter for Type B transmitters.
+
+**Table 11-7bis – The lower boundary ER and mean launch power pairs of the Type A ONU transmitter admissible region**
+
+|                                | $(\bar{P}_1, ER_1)$ | $(\bar{P}_2, ER_2)$ | $(\bar{P}_3, ER_3)$ | $(\bar{P}_4, ER_4)$ | $(\bar{P}_5, ER_5)$ |
+|--------------------------------|---------------------|---------------------|---------------------|---------------------|---------------------|
+| Mean launch optical power, dBm | 3.0                 | 4.0                 | 5.0                 | 7.0                 | 9.0                 |
+| Extinction ratio, dB           | 8.0                 | 6.0                 | 5.0                 | 4.0                 | 4.0                 |
+
+**Table 11-7ter – The lower boundary ER and mean launch power pairs of the Type B ONU transmitter admissible region**
+
+|                                | $(\bar{P}_1, ER_1)$ | $(\bar{P}_2, ER_2)$ | $(\bar{P}_3, ER_3)$ | $(\bar{P}_4, ER_4)$ | $(\bar{P}_5, ER_5)$ |
+|--------------------------------|---------------------|---------------------|---------------------|---------------------|---------------------|
+| Mean launch optical power, dBm | 1.0                 | 2.0                 | 3.5                 | 5.0                 | 7.0                 |
+| Extinction ratio, dB           | 8.0                 | 6.0                 | 5.0                 | 4.0                 | 4.0                 |
+
+This admissible region represents a relaxation of the transmitter parameters as compared with the requirements of Table 11-7, where the mean launch optical power and extinction ratio were specified independently from each other (thus limiting the admissible region to a densely shaded rectangular area in Figure 11-0). The boundaries shown by the square with the thin black lines represent the allowable transmit power and extinction ratio defined in Table 11-7.
+
+#### **11.1.5 Transmitter at reference point S**
+
+All parameters are defined as follows, and are in accordance with Table 11-4 to Table 11-7.
+
+#### **11.1.5.1 Source type**
+
+Considering the attenuation/dispersion characteristics of the target fibre channel, suitable transmitter devices include only single longitudinal mode (SLM) lasers. The indication of a nominal source type in this Recommendation is not a requirement though it is also expected that only SLM lasers meet all the distance and line rate requirements of both the downstream and upstream links.
+
+##### **11.1.5.2 Spectral characteristics**
+
+For SLM lasers, the laser is specified by its fibre dispersion range, the range over which the laser characteristics and fibre dispersion result in a defined penalty at a specified fibre distance, under standard operating conditions. Additionally, for control of mode partition noise in SLM systems, a minimum value for the laser SMSR is specified. The actual spectral characteristics are limited by the maximum amount of OPP produced with the worst-case optical dispersion in the data signal.
+
+##### **11.1.5.2.1 Operating wavelength band**
+
+Operating wavelength band specification options are summarized in Table 9-1.
+
+##### **11.1.5.2.2 Nominal central frequency**
+
+The central frequencies are based on the frequency grid given in [ITU-T G.694.1]. The downstream central frequencies are specified in Table 11-2. Examples of TWDM upstream channel grid are in Clause VIII.4.
+
+Note that the value of "c" (speed of light in a vacuum) that is used for converting between frequency and wavelength is  $2.99792458 \times 10^8$  m/s.
+
+##### **11.1.5.2.3 Operating channel spacing**
+
+The specified value of the operating CS is used to parameterize the spectral properties of a laser.
+
+##### **11.1.5.2.4 Maximum spectral excursion**
+
+The maximum spectral excursion is specified as a one-sided deviation from the nominal central wavelength and is expressed in gigahertz. The maximum spectral excursion requirement applies to fixed wavelength transmitters as well as tunable wavelength transmitters. For tunable wavelength transmitters, it only applies while they are in a stationary wavelength channel state.
+
+Among the tunable transmitters, the maximum spectral excursion requirement applies to both tunable transmitters, which are under fine wavelength control of the OLT, and tunable transmitters, which are not under fine wavelength control of the OLT.
+
+In the application to NG-PON2, MSE is the total allowable excursion due to:
+
+- spectral width, tuning granularity, short-term wavelength drift (over one OLT-ONU tuning cycle) and tuning control errors, when tunable ONU transmitters under fine OLT control are used;
+- spectral width, tuning granularity and tuning accuracy, when tunable ONU transmitters not under fine OLT control are used.
+
+![Figure 11-1 – Spectral excursion illustration. A graph showing Power relative to peak (dB) on the y-axis (from -30 to 0) versus Offset from nominal central frequency (GHz) on the x-axis. The x-axis has a central point at 0. Three vertical lines are marked: 'Nominal central frequency minus maximum spectral excursion' on the left, 'Nominal central frequency' at 0, and 'Nominal central frequency plus maximum spectral excursion' on the right. The spectral curve peaks at 0 dB at the nominal frequency and has a 'Spectral excursion' indicated by a double-headed arrow between the minus and plus excursion points. The area outside the excursion points is shaded grey.](183007754364096b2d89f42200cf870f_img.jpg)
+
+G.989.2(14)-Amd.1(16)\_F11-1
+
+Figure 11-1 – Spectral excursion illustration. A graph showing Power relative to peak (dB) on the y-axis (from -30 to 0) versus Offset from nominal central frequency (GHz) on the x-axis. The x-axis has a central point at 0. Three vertical lines are marked: 'Nominal central frequency minus maximum spectral excursion' on the left, 'Nominal central frequency' at 0, and 'Nominal central frequency plus maximum spectral excursion' on the right. The spectral curve peaks at 0 dB at the nominal frequency and has a 'Spectral excursion' indicated by a double-headed arrow between the minus and plus excursion points. The area outside the excursion points is shaded grey.
+
+**Figure 11-1 – Spectral excursion illustration**
+
+The NRZ 'zero' power is allowed outside of the MSE but impact on OOC power must be considered.
+
+##### 11.1.5.2.5 Minimum tuning window
+
+The minimum tuning window is specified as a positive number in gigahertz. To satisfy the requirement, a component or device must meet or exceed the specified value.
+
+###### 11.1.5.2.6 Tuning granularity
+
+The tuning granularity is specified as a positive number in gigahertz. To satisfy the requirement, a component or device must not exceed the specified value.
+
+##### 11.1.5.2.7 ONU transmitter power wavelength dependency
+
+The ONU transmitter power wavelength dependency is specified as a ratio greater than one and is expressed in decibels. To satisfy the requirement a component or device must not exceed the specified value.
+
+###### 11.1.5.2.8 Mean launch optical power
+
+The mean launch optical power is specified as a range to allow for some cost optimization and to cover all allowances for operation under standard operating conditions, transmitter connector degradation, measurement tolerances and ageing effects.
+
+In the operating state, the lower figure is the minimum power to be provided and the higher one is the power never to be exceeded.
+
+NOTE – Measurement of the launch power at the ONU reference point S optical interface must take into account the bursty nature of the upstream traffic transmitted by the ONUs.
+
+##### 11.1.5.2.9 Upstream optical PSD when not enabled (WNE-PSD)
+
+In the upstream direction, the ONU transmitter ideally launches no power into the fibre in all bursts which are not assigned to that ONU. However, an optical power level less than or equal to the upstream WNE-PSD is allowed during bursts which are not assigned to that ONU. During the transmitter enable transient time immediately preceding the assigned burst, which may be used for laser pre-bias, and during the transmitter disable transient time immediately following the assigned
+
+burst, the maximum launch power level allowed is the zero level corresponding to the minimum ER and the maximum channel launch power specified in Tables 11-6 and 11-7.
+
+The specification of the maximum transmitter enable and transmitter disable transient times is provided in Tables 11-6 and 11-7.
+
+The relationship between ONU power levels and burst times is shown in Figure 11-2.
+
+![Figure 11-2: Relationship between ONU power levels and burst times. The graph shows Transmitter optical power on the y-axis and Time on the x-axis. The y-axis has labels for 'One bit level', 'Zero bit level', and 'Power level when not enabled'. The x-axis is divided into segments: 'Transmitter enable', 'Preamble', 'Delimiter', 'Rest of the burst', and 'Transmitter disable'. The 'Rest of the burst' segment shows a shaded area representing the data burst. The 'Transmitter enable' and 'Transmitter disable' segments show hatched areas representing transient power levels. The diagram is labeled G.989.2(14)_F11-2 at the bottom right.](8f38356601e137ac471fc4771b9c5a5c_img.jpg)
+
+The figure is a timing diagram illustrating the relationship between ONU power levels and burst times. The vertical axis represents 'Transmitter optical power' with three marked levels: 'One bit level', 'Zero bit level', and 'Power level when not enabled'. The horizontal axis represents 'Time'. The burst is divided into several temporal segments: 'Transmitter enable', 'Preamble', 'Delimiter', 'Rest of the burst', and 'Transmitter disable'. During the 'Transmitter enable' and 'Transmitter disable' phases, the power level transitions between the 'Zero bit level' and the 'Power level when not enabled' level, indicated by hatched regions. The 'Preamble' and 'Delimiter' consist of a series of pulses between the 'One bit level' and 'Zero bit level'. The 'Rest of the burst' is shown as a shaded region, indicating the main data payload. The diagram is identified by the label 'G.989.2(14)\_F11-2' in the bottom right corner.
+
+Figure 11-2: Relationship between ONU power levels and burst times. The graph shows Transmitter optical power on the y-axis and Time on the x-axis. The y-axis has labels for 'One bit level', 'Zero bit level', and 'Power level when not enabled'. The x-axis is divided into segments: 'Transmitter enable', 'Preamble', 'Delimiter', 'Rest of the burst', and 'Transmitter disable'. The 'Rest of the burst' segment shows a shaded area representing the data burst. The 'Transmitter enable' and 'Transmitter disable' segments show hatched areas representing transient power levels. The diagram is labeled G.989.2(14)\_F11-2 at the bottom right.
+
+Figure 11-2 – Relationship between ONU power levels and burst times
+
+#### 11.1.5.3 Mask of transmitter eye diagram
+
+This clause specifies the pulse shape characteristics for the OLT and ONU transmitters. For the purpose of assessing the transmit signal, it is important to consider not only the eye opening, but also the overshoot and undershoot limitations.
+
+##### 11.1.5.3.1 OLT transmitter
+
+The parameters specifying the mask of the eye diagram (see Figure 11-3) for the OLT transmitter are shown in Table 11-8. The test set-up for the measurement of the mask of the eye diagram is shown in Figure 11-4.
+
+![Figure 11-3: Mask of the eye diagram for OLT transmitter. The diagram shows an eye diagram with a rectangular mask overlaid. The vertical axis represents amplitude, with markers at -y4, 0, y1, 0.5, y2, 1, and 1+y3. The horizontal axis represents time, with markers at 0, x2, x3, and 1. The mask is a rectangle defined by x2, x3, y1, and y2. The mean level of the center of logical '1' is indicated at level 1, and the mean level of the center of logical '0' is indicated at level 0. The diagram is labeled G.989.2(14)_F11-3.](fe655d77258397f7242c2df72b965b56_img.jpg)
+
+Figure 11-3: Mask of the eye diagram for OLT transmitter. The diagram shows an eye diagram with a rectangular mask overlaid. The vertical axis represents amplitude, with markers at -y4, 0, y1, 0.5, y2, 1, and 1+y3. The horizontal axis represents time, with markers at 0, x2, x3, and 1. The mask is a rectangle defined by x2, x3, y1, and y2. The mean level of the center of logical '1' is indicated at level 1, and the mean level of the center of logical '0' is indicated at level 0. The diagram is labeled G.989.2(14)\_F11-3.
+
+Figure 11-3 – Mask of the eye diagram for OLT transmitter
+
+Table 11-8 – Mask of the eye diagram for OLT transmitter – numeric values
+
+|                      | 2.48832 Gbit/s | 9.95328 Gbit/s |
+|----------------------|----------------|----------------|
+| $x_3 - x_2$ (Note 1) | 0.2            | 0.2            |
+| $y_1, y_3, y_4$      | 0.25           | 0.25           |
+| $y_2$                | 0.75           | 0.75           |
+
+NOTE 1 –  $x_2$  and  $x_3$  of the rectangular eye mask need not be equidistant with respect to the vertical axes at 0 unit interval (UI) and 1 UI.
+
+NOTE 2 – The values are taken from [ITU-T G.959.1], clause 7.2.2.14.
+
+![Figure 11-4: Test set-up for measuring the mask of the eye diagram for OLT transmitter. The block diagram shows a sequence of four components: Optical transmitter, Attenuator (a), O/E converter fourth-order Thomson filter (b), and Waveform monitor. The signal flows from left to right. The diagram is labeled G.989.2(14)_F11-4.](409498e57b1f988b2b604d12cd997002_img.jpg)
+
+Figure 11-4: Test set-up for measuring the mask of the eye diagram for OLT transmitter. The block diagram shows a sequence of four components: Optical transmitter, Attenuator (a), O/E converter fourth-order Thomson filter (b), and Waveform monitor. The signal flows from left to right. The diagram is labeled G.989.2(14)\_F11-4.
+
+<sup>a)</sup> Attenuator is used if necessary.
+
+<sup>b)</sup> Cut-off frequency (3 dB attenuation frequency) of the filter is 0.75 times output nominal bit rate.
+
+Figure 11-4 – Test set-up for measuring the mask of the eye diagram for OLT transmitter
+
+##### 11.1.5.3.2 ONU transmitter
+
+###### 11.1.5.3.2.1 ONU transmitter eye diagram
+
+The parameters specifying the mask of the eye diagram (see Figure 11-5) for the ONU transmitter are shown in Table 11-9. The test set-up for the measurement of the mask of the eye diagram is shown in Figure 11-6.
+
+The mask of the eye diagram for the upstream direction burst mode signal is applied from the first bit of the preamble to the last bit of the burst signal, inclusive.
+
+![Figure 11-5: Mask of the eye diagram for ONU transmitter. The diagram shows an eye diagram with a rectangular mask overlaid. The vertical axis represents voltage levels from -1 to 1, with markers at -1+y3, 1, y2, 0.5, y1, 0, and -y4. The horizontal axis represents time from 0 to 1. The mask is defined by x2 and x3 on the horizontal axis and y1, y2, y3, and y4 on the vertical axis. Annotations indicate the mean level of the center of logical '1' and the mean level of the center of logical '0'. The figure is labeled G.989.2(14)_F11-5.](f24d06b5e3b1d8ae12d4893e7619f6f5_img.jpg)
+
+Figure 11-5: Mask of the eye diagram for ONU transmitter. The diagram shows an eye diagram with a rectangular mask overlaid. The vertical axis represents voltage levels from -1 to 1, with markers at -1+y3, 1, y2, 0.5, y1, 0, and -y4. The horizontal axis represents time from 0 to 1. The mask is defined by x2 and x3 on the horizontal axis and y1, y2, y3, and y4 on the vertical axis. Annotations indicate the mean level of the center of logical '1' and the mean level of the center of logical '0'. The figure is labeled G.989.2(14)\_F11-5.
+
+**Figure 11-5 – Mask of the eye diagram for ONU transmitter**
+
+**Table 11-9 – Mask of the eye diagram for ONU transmitter – numeric values**
+
+|                      | 2.48832 Gbit/s | 9.95328 Gbit/s |
+|----------------------|----------------|----------------|
+| $x_3 - x_2$ (Note 1) | 0.2            | 0.2            |
+| $y_1, y_3, y_4$      | 0.25           | 0.25           |
+| $y_2$                | 0.75           | 0.75           |
+
+NOTE 1 –  $x_2$  and  $x_3$  of the rectangular eye mask need not be equidistant with respect to the vertical axes at 0 UI and 1 UI.
+
+NOTE 2 – The values are taken from [ITU-T G.957], clause 6.2.5.
+
+![Figure 11-6: Test set-up for measuring the mask of the eye diagram for ONU transmitter. The block diagram shows an Optical transmitter connected to an Attenuator (a), which is connected to an O/E converter fourth-order Thomson filter (b), which is connected to a Waveform monitor. The figure is labeled G.989.2(14)_F11-6.](fb18a83d10ebdad8e3e5ea2e86b36136_img.jpg)
+
+Figure 11-6: Test set-up for measuring the mask of the eye diagram for ONU transmitter. The block diagram shows an Optical transmitter connected to an Attenuator (a), which is connected to an O/E converter fourth-order Thomson filter (b), which is connected to a Waveform monitor. The figure is labeled G.989.2(14)\_F11-6.
+
+<sup>a)</sup> Attenuator is used if necessary.
+
+<sup>b)</sup> Cut-off frequency (3 dB attenuation frequency) of the filter is 0.75 times output nominal bit rate.
+
+**Figure 11-6 – Test set-up for measuring the mask of the eye diagram for ONU transmitter**
+
+#### 11.1.5.4 Jitter performance
+
+This clause describes jitter requirements for optical interfaces of TWDM PON.
+
+###### 11.1.5.4.1 Jitter transfer
+
+The jitter transfer specification applies only to the ONU.
+
+The jitter transfer function is defined as:
+
+$$jitter\ transfer = 20 \log_{10} \left[ \frac{jitter\ on\ upstream\ signal\ UI}{jitter\ on\ downstream\ signal\ UI} \times \frac{down\ stream\ bit\ rate}{upstream\ bit\ rate} \right]$$
+
+The jitter transfer function of an ONU shall be under the curve given in Figure 11-7, when input sinusoidal jitter up to the mask level in Figure 11-8 is applied, with the parameters specified in this figure for each line rate.
+
+![Graph of Jitter gain vs Frequency for ONU. The y-axis is Jitter gain (P) and the x-axis is Frequency. The graph shows a flat response from f_L to f_C, followed by a -20 dB/dec slope down to f_H. Reference G.989.2(14)_F11-7.](f899c67120dc04a5e5a5c2d94461a077_img.jpg)
+
+Figure 11-7 shows the jitter gain for an ONU. The y-axis represents Jitter gain (P) and the x-axis represents Frequency. The graph shows a flat response from  $f_L$  to  $f_C$ , followed by a  $-20$  dB/dec slope down to  $f_H$ . The reference is G.989.2(14)\_F11-7.
+
+Graph of Jitter gain vs Frequency for ONU. The y-axis is Jitter gain (P) and the x-axis is Frequency. The graph shows a flat response from f\_L to f\_C, followed by a -20 dB/dec slope down to f\_H. Reference G.989.2(14)\_F11-7.
+
+| Upstream line rate (Gbit/s)                       | $f_L$ (kHz) | $f_C$ (kHz) | $f_H$ (kHz) | P (dB) |
+|---------------------------------------------------|-------------|-------------|-------------|--------|
+| 2.48832                                           | 20          | 2000        | 20 000      | 0.1    |
+| 9.95328                                           | 10          | 1000        | 80 000      | 0.1    |
+| NOTE – These values are taken from [ITU-T G.783]. |             |             |             |        |
+
+Figure 11-7 – Jitter transfer for ONU
+
+![Graph of Input jitter amplitude vs Frequency for jitter transfer. The y-axis is Input jitter amplitude (A3, A4) and the x-axis is Frequency. The graph shows a flat response at A3 from low frequency to f2, a -20 dB/dec slope from f2 to f3, and a flat response at A4 from f3 to high frequency. Reference G.989.2(14)_F11-8.](771c18f874d31c59c3b8c4e247be16ca_img.jpg)
+
+Figure 11-8 shows the high-band portion of the sinusoidal jitter mask for jitter transfer. The y-axis represents Input jitter amplitude ( $A_3$ ,  $A_4$ ) and the x-axis represents Frequency. The graph shows a flat response at  $A_3$  from low frequency to  $f_2$ , a  $-20$  dB/dec slope from  $f_2$  to  $f_3$ , and a flat response at  $A_4$  from  $f_3$  to high frequency. The reference is G.989.2(14)\_F11-8.
+
+Graph of Input jitter amplitude vs Frequency for jitter transfer. The y-axis is Input jitter amplitude (A3, A4) and the x-axis is Frequency. The graph shows a flat response at A3 from low frequency to f2, a -20 dB/dec slope from f2 to f3, and a flat response at A4 from f3 to high frequency. Reference G.989.2(14)\_F11-8.
+
+| Downstream line rate (Gbit/s)                     | $A_3$ (UI) | $A_4$ (UI) | $f_2$ (kHz) | $f_3$ (kHz) |
+|---------------------------------------------------|------------|------------|-------------|-------------|
+| 2.48832                                           | 1.5        | 0.15       | 100         | 1000        |
+| 9.95328                                           | 1.5        | 0.15       | 400         | 4000        |
+| NOTE – These values are taken from [ITU-T G.783]. |            |            |             |             |
+
+Figure 11-8 – High-band portion of sinusoidal jitter mask for jitter transfer
+
+![Figure 11-9: Jitter tolerance mask graph. The y-axis is 'Input jitter amplitude' with levels A1 and A2. The x-axis is 'Frequency' with markers f0 and ft. The mask shows a constant level A2 from 0 to f0, a downward slope of -20 dB/dec from f0 to ft, and a constant level A1 from ft onwards. The text 'G.989.2(14)_F11-9' is at the bottom right.](bd4a5cf22b8d8060c4bf3577beb30df8_img.jpg)
+
+Figure 11-9: Jitter tolerance mask graph. The y-axis is 'Input jitter amplitude' with levels A1 and A2. The x-axis is 'Frequency' with markers f0 and ft. The mask shows a constant level A2 from 0 to f0, a downward slope of -20 dB/dec from f0 to ft, and a constant level A1 from ft onwards. The text 'G.989.2(14)\_F11-9' is at the bottom right.
+
+| Line rate (Gbit/s)                                                                   | $f_t$ (kHz) | $f_0$ (kHz) | A1 (UIp-p) | A2 (UIp-p) |
+|--------------------------------------------------------------------------------------|-------------|-------------|------------|------------|
+| 2.48832                                                                              | 1000        | 100         | 0.075      | 0.75       |
+| 9.95328                                                                              | 4000        | 400         | 0.075      | 0.75       |
+| NOTE – These values are scaled to 9.95328 Gbit/s from the values in [ITU-T G.984.2]. |             |             |            |            |
+
+Figure 11-9 – Jitter tolerance mask
+
+##### 11.1.5.4.2 Jitter tolerance
+
+Jitter tolerance is defined as the peak-to-peak amplitude of sinusoidal jitter applied on the input TWDM PON signal that causes a 1-dB optical power penalty at the optical receiver. Note that it is a stress test to ensure that no additional penalty is incurred under operating conditions.
+
+The ONU must tolerate, as a minimum, the input jitter applied according to the mask in Figure 11-9, with the parameters specified in that figure for the downstream line rate. The OLT must tolerate, as a minimum, the input jitter applied according to the mask in Figure 11-9, with the parameters specified in that figure for the upstream line rate. The jitter tolerance specification for the OLT is informative as it can only be measured in a setting that permits continuous operation of the upstream.
+
+##### 11.1.5.4.3 Jitter generation
+
+An ONU must not generate a peak-to-peak jitter amplitude more than shown in Table 11-10 with no jitter applied to the downstream input and with a measurement bandwidth as specified in Table 11-10. An OLT must not generate a peak-to-peak jitter amplitude more than shown in Table 11-10 with no jitter applied to its timing reference input and with a measurement band as specified in Table 11-10.
+
+Table 11-10 – Jitter generation requirements for TWDM PON
+
+| Line rate (Gbit/s) | Measurement band<br>(-3 dB frequencies)<br>(Note 1) |                              | Peak-peak amplitude<br>(UI)<br>(Note 2) |
+|--------------------|-----------------------------------------------------|------------------------------|-----------------------------------------|
+|                    | high-pass<br>(kHz)                                  | low-pass (MHz)<br>-60 dB/dec |                                         |
+| 2.48832            | 5                                                   | 20                           | 0.30                                    |
+|                    | 1000                                                | 20                           | 0.10                                    |
+| 9.95328            | 20                                                  | 80                           | 0.30                                    |
+|                    | 4000                                                | 80                           | 0.10                                    |
+
+| Line rate (Gbit/s)                                                                                                                                                                                                                                                     | Measurement band<br>(-3 dB frequencies)<br>(Note 1) |                              | Peak-peak amplitude<br>(UI)<br>(Note 2) |
+|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------|------------------------------|-----------------------------------------|
+|                                                                                                                                                                                                                                                                        | high-pass<br>(kHz)                                  | low-pass (MHz)<br>-60 dB/dec |                                         |
+| NOTE 1 – The high-pass and low-pass measurement filter transfer functions are defined in clause 5 of [ITU-T G.825].<br>NOTE 2 – The measurement time and pass/fail criteria are defined in clause 5 of [ITU-T G.825].<br>NOTE 3 – This table comes from [ITU-T G.783]. |                                                     |                              |                                         |
+
+## 11.2 Upstream physical layer overhead
+
+Table 11-11 shows the length of the physical layer overhead bits for the upstream line rate specified in this Recommendation.
+
+**Table 11-11 – TWDM PON upstream physical layer overhead**
+
+| Upstream line rate | Overhead bits |
+|--------------------|---------------|
+| 2.48832 Gbit/s     | 512           |
+| 9.95328 Gbit/s     | 2048          |
+
+Moreover, Appendix III provides information on the physical processes that have to be performed during the physical layer overhead time (Tplo) and some guidelines optimum use of Tplo.
+
+# Annex A
+
+## Tunable PtP WDM PON PMD layer requirements
+
+(This annex forms an integral part of this Recommendation.)
+
+This annex describes a PtP WDM PON system with wavelength tunability.
+
+The characteristic of a PtP WDM PON is that each ONU is served by one pair of upstream and downstream wavelengths dedicated to this ONU. On the OLT side, downstream wavelengths are multiplexed onto a shared, bidirectional fibre connecting the wavelength multiplexer (WM) to a branching node (BN). Figure A.1 shows a logical view of a PtP WDM PON.
+
+![Figure A.1 – Logical architecture of a generic PtP WDM PON. The diagram shows multiple PtP WDM OLTs connected to a Wavelength Multiplexer (WM) via channel pairs S/R-CP1, S/R-CP2, S/R-CP3, and S/R-CPn. The WM is connected to a Branching node (BN). The BN is connected to four PtP WDM ONUs. A 'λ selection function' is shown above the BN, with arrows pointing to each of the four ONUs, indicating that the selection function is applied at each ONU to select the appropriate wavelength pair.](34b047489058d6400b412cd0ae2334ba_img.jpg)
+
+CG – channel group  
+CP – channel pair  
+WM – wavelength mux
+
+G.989.2(14)\_FA.1
+
+Figure A.1 – Logical architecture of a generic PtP WDM PON. The diagram shows multiple PtP WDM OLTs connected to a Wavelength Multiplexer (WM) via channel pairs S/R-CP1, S/R-CP2, S/R-CP3, and S/R-CPn. The WM is connected to a Branching node (BN). The BN is connected to four PtP WDM ONUs. A 'λ selection function' is shown above the BN, with arrows pointing to each of the four ONUs, indicating that the selection function is applied at each ONU to select the appropriate wavelength pair.
+
+Figure A.1 – Logical architecture of a generic PtP WDM PON
+
+Examples of PtP WDM PON clients include GbE, 10GbE and common public radio interface (CPRI) [b-CPRI]. The OLT channel pair may also exist in multiple instances, particularly to support different client types.
+
+At a BN, the ODN branches out to drop fibres, one for each ONU. The feeder and BN may be further divided into sub-trees, and part or all of the feeder-BN tree, and even the drop fibres, may be duplicated for redundancy. The BN may include any combination of power splitters, bandpass or bandstop filters, or wavelength filters (e.g., arrayed waveguide gratings (AWGs)). Logically, a wavelength selection function is required between each port of the BN and the corresponding colourless ONU transceiver.
+
+This wavelength selector can be located physically either within the ONU (wavelength selected case) or at a BN (wavelength routed case), giving rise to two classes of PtP WDM PON architecture:
+
+**Wavelength-selected:** The  $\lambda$  selection function is built into the ONU. Part or all of the spectrum is available to the ONU (power split with or without bandpass filter) such that it is possible for the ONU and OLT to communicate on part or all of the spectrum. The ONU determines its wavelength in an activation process that involves the OLT. The upstream wavelength is typically established as a fixed function of the assigned downstream wavelength. This class of PtP WDM PON supports power splitter ODN.
+
+This annex focuses on the wavelength-selected class of PtP WDM PON as an overlay to TWDM PON.
+
+**Wavelength-routed:** The  $\lambda$  selection function is part of the BN. The ONU's wavelength is determined by its physical connectivity to the ODN, for example by a port on an AWG. Upstream and downstream wavelengths may be the same, or may differ by a multiple of the free spectral range (FSR) of the AWG. This class of PtP WDM PON supports filtered ODN.
+
+ONUs that have no wavelength selective capability, i.e., that can only support a fully wavelength routed architecture, are out of scope of this annex.
+
+### A.1 PMD layer requirements
+
+The PtP WDM PON system must support minimum four PtP WDM channels.
+
+All parameters are specified as follows, and are in accordance with Table A.2 to Table A.7.
+
+All parameter values specified are worst-case values, to be met over the range of operating conditions such as temperature and humidity, and include ageing effects, as specified in [ITU-T G.989.1]. The parameters are specified relative to a BER not worse than the values specified in Table A.2 to Table A.7, for the worst-case optical path loss (see Table 6-1) and fibre chromatic dispersion.
+
+#### A.1.1 Line rate
+
+This clause specifies the line rates required to support various PtP WDM PON clients.
+
+Parameters to be specified are categorized by downstream and upstream, and the nominal line rates as shown in Table A.1.
+
+The PtP WDM PON supports three classes of line rates. Each line rate applies for a symmetric service protocol, i.e., the downstream and the upstream line rates are identical for the respective service protocol. The downstream and upstream PMD parameters are specified in Table A.2 to Table A.7.
+
+**Table A.1 – Relation between PtP WDM PON line rate classes and optical parameter tables**
+
+| Line rate class | Nominal line rate (Gbit/s) – Symmetric DS and US                    | Supported UNI                                                                                           | Reference table downstream/upstream |
+|-----------------|---------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------|-------------------------------------|
+| 1               | 1.24416,<br>1.25,<br>1.2288                                         | STM-8<br>1G Ethernet<br>CPRI option 2                                                                   | Table A.2/Table A.3                 |
+| 2               | 2.48832,<br>2.4576,<br>2.666                                        | OC-48, STM-16<br>CPRI option 3<br>OTU1                                                                  | Table A.4/Table A.5                 |
+| 3               | 6.144<br>9.95328,<br>9.8304,<br>10.709, 11.09<br>10.3125<br>10.1376 | CPRI option 6, OBSAI<br>OC-192, STM-64<br>CPRI option 7<br>OTU2, OTU2e<br>10G Ethernet<br>CPRI option 8 | Table A.6/Table A.7                 |
+
+#### A.1.2 FEC code selection
+
+The choice of FEC depends on the service protocol.
+
+For CPRI, no FEC is used.
+
+For 1 Gbit/s Ethernet services with 8b/10b coding, no FEC is used.
+
+For 10GBASE-ER Ethernet with 64b/66b coding, no FEC is used.
+
+For OC-48, OC-192, STM-8, STM-16 and STM-64, the inbuilt FEC according to [ITU-T G.707] and [ITU-T G.709] may be used. No extra FEC overhead is applied.
+
+For OTU1, OTU2, and OTU2e the inbuilt FEC as of [ITU-T G.709] may be applied. No extra FEC overhead is applied.
+
+#### A.1.3 Line code
+
+Line coding for PtP WDM PON is determined by the specific application.
+
+#### A.1.4 Operating wavelength
+
+The PtP WDM PON spectrum is specified according to Table 9-1, subject to spectrum otherwise assigned or in use.
+
+Two wavelength bands for PtP WDM PON are specified:
+
+- 1) Shared spectrum band: 1603-1625 nm
+
+Details of the sharing between TWDM PON and PtP WDM PON bands are specified in clause 9.2.
+
+- 2) Expanded spectrum band: 1524-1625 nm
+
+Spectral flexibility is required to allow reuse of unoccupied bands in other coexistence scenarios where legacy bands and TWDM PON bands are available.
+
+For the purpose of coexistence with G-PON, XG-PON1, RF video and four TWDM channels, a minimum of four PtP WDM channels is supported.
+
+Upstream and downstream can be in separate spectral regions or share the same spectral band.
+
+#### A.1.5 PMD parameters
+
+##### A.1.5.1 Compatible ODN
+
+PtP WDM PON operates over the same ODN as TWDM PON, see clause 11.1.4.1.
+
+##### A.1.5.2 Optical interface parameters for line rate class 1
+
+The following optical interface parameter tables are applicable for up to 40 km fibre length and a minimum of 4 PtP WDM channels.
+
+**Table A.2 – Optical interface parameters for line rate class 1  
+(from 1.2288 Gbit/s to 1.25 Gbit/s) downstream direction**
+
+| Item                                         | Unit   | Value                                                                        |
+|----------------------------------------------|--------|------------------------------------------------------------------------------|
+| <b>OLT transmitter (optical interface S)</b> |        |                                                                              |
+| Nominal line rate                            | Gbit/s | 1.2288 to 1.25                                                               |
+| Operating wavelength band                    | nm     | 1603-1625 (shared spectrum)<br>1524-1625 (expanded spectrum)                 |
+| Minimum operating channel spacing            | GHz    | 50                                                                           |
+| Maximum operating channel spacing            | GHz    | 200                                                                          |
+| Maximum spectral excursion                   | GHz    | +/-12.5 for 50GHz CS<br>+/-20 for 100GHz CS<br>+/-25 for 200GHz CS           |
+| Line code                                    | –      | Determined by application<br>(scrambled NRZ assumed<br>for parameter values) |
+| Mask of the transmitter eye diagram          | –      | See clause A.1.6.2                                                           |
+
+**Table A.2 – Optical interface parameters for line rate class 1  
+(from 1.2288 Gbit/s to 1.25 Gbit/s) downstream direction**
+
+| Item                                                                                               | Unit            | Value                                                                                                                                                                                                                                                                           |       |       |       |
+|----------------------------------------------------------------------------------------------------|-----------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------|-------|-------|
+| Maximum reflectance of equipment at S/R-CG, measured at transmitter wavelength                     | dB              | NA                                                                                                                                                                                                                                                                              |       |       |       |
+| Minimum ORL of ODN at S/R-CG                                                                       | dB              | 32                                                                                                                                                                                                                                                                              |       |       |       |
+| ODN Class                                                                                          |                 | N1                                                                                                                                                                                                                                                                              | N2    | E1    | E2    |
+| Mean channel launch power minimum (at S/R-CG) without FEC                                          | dBm             | -1                                                                                                                                                                                                                                                                              | +1    | +3    | +5    |
+| Mean channel launch power minimum (at S/R-CG) with FEC                                             | dBm             | 0                                                                                                                                                                                                                                                                               | +2    | +4    | +6    |
+| Mean channel launch power maximum (at S/R-CG) without FEC                                          | dBm             | +3                                                                                                                                                                                                                                                                              | +5    | +7    | +9    |
+| Mean channel launch power maximum (at S/R-CG) with FEC                                             | dBm             | +4                                                                                                                                                                                                                                                                              | +6    | +8    | +10   |
+| Maximum downstream WNE-PSD                                                                         | dBm<br>(15 GHz) | -63.7                                                                                                                                                                                                                                                                           |       |       |       |
+| Minimum extinction ratio (Note 1)                                                                  | dB              | 8.2                                                                                                                                                                                                                                                                             |       |       |       |
+| Tolerance to reflected optical power                                                               | dB              | -15                                                                                                                                                                                                                                                                             |       |       |       |
+| Dispersion range (Note 2)                                                                          | ps/nm           | $0 \text{ to } \frac{0.092 \times \lambda}{4} \left[ 1 - \left( \frac{1300}{\lambda} \right)^2 \right] \times 20 \quad (\text{DD20}),$<br>$0 \text{ to } \frac{0.092 \times \lambda}{4} \left[ 1 - \left( \frac{1300}{\lambda} \right)^2 \right] \times 40 \quad (\text{DD40})$ |       |       |       |
+| Minimum side mode suppression ratio (at S/R-CP)                                                    | dB              | 30                                                                                                                                                                                                                                                                              |       |       |       |
+| Maximum downstream per channel out-of-band optical PSD (Assuming eight Ch PtP WDM PON) (Note 3)    | dBm<br>(15 GHz) | -46.5                                                                                                                                                                                                                                                                           |       |       |       |
+| Maximum downstream per channel out-of-channel optical PSD (Assuming eight Ch PtP WDM PON) (Note 4) | dBm<br>(15 GHz) | -52.1                                                                                                                                                                                                                                                                           |       |       |       |
+| Jitter generation                                                                                  | –               | See clause A.1.6.3                                                                                                                                                                                                                                                              |       |       |       |
+| ONU receiver (optical interface R)                                                                 |                 |                                                                                                                                                                                                                                                                                 |       |       |       |
+| Maximum OPP (Note 5)                                                                               | dB              | 1.5 (without FEC)                                                                                                                                                                                                                                                               |       |       |       |
+| – with Raman effects                                                                               |                 | 1.0 (with FEC ON)                                                                                                                                                                                                                                                               |       |       |       |
+| Maximum reflectance of equipment at R/S, measured at receiver wavelength                           | dB              | -20                                                                                                                                                                                                                                                                             |       |       |       |
+| Rx wavelength channel tuning time                                                                  |                 | See Table 9-2                                                                                                                                                                                                                                                                   |       |       |       |
+| Maximum tuning granularity                                                                         | GHz             | CS/20                                                                                                                                                                                                                                                                           |       |       |       |
+| ODN Class                                                                                          |                 | N1                                                                                                                                                                                                                                                                              | N2    | E1    | E2    |
+| Sensitivity (at R/S) @ BER=10 <sup>-12</sup>                                                       | dBm             | -31.5                                                                                                                                                                                                                                                                           | -31.5 | -31.5 | -31.5 |
+| Sensitivity (at R/S) @ BER=10 <sup>-4</sup> (Note 6)                                               | dBm             | -30                                                                                                                                                                                                                                                                             | -30   | -30   | -30   |
+| Overload (at R/S) @ BER=10 <sup>-12</sup>                                                          | dBm             | -11                                                                                                                                                                                                                                                                             | -11   | -11   | -11   |
+| Overload (at R/S) @ BER=10 <sup>-4</sup> (Note 6)                                                  | dBm             | -10                                                                                                                                                                                                                                                                             | -10   | -10   | -10   |
+
+**Table A.2 – Optical interface parameters for line rate class 1  
+(from 1.2288 Gbit/s to 1.25 Gbit/s) downstream direction**
+
+| Item                                 | Unit           | Value              |
+|--------------------------------------|----------------|--------------------|
+| In-band crosstalk tolerance          | dB<br>(15 GHz) | 39.3               |
+| Consecutive identical digit immunity | bit            | 72                 |
+| Jitter tolerance                     | –              | See clause A.1.6.3 |
+
+NOTE 1 – A lower extinction ratio must be compensated by a larger transmitter launch power within the limits of the mean launch power maximum value.
+
+NOTE 2 – This formula (see clause 6.10 of [ITU-T G.652]) is used instead of the worst case value due to the large variation of dispersion within the PtP WDM PON wavelength band. This allows implementers to build devices only to the desired dispersion specification.  $\lambda$  is the longest possible wavelength in each channel, in nanometre units, considering the spectral excursion.
+
+NOTE 3 – This value is based the following assumptions: OOB impact from PtP WDM PON on TWDM PON can be controlled through appropriate filtering, 0.1 dB penalty, TWDM PON operates with FEC, and eight PtP WDM channels (seven interferers).
+
+NOTE 4 – This value is based the following assumptions: OOC in downstream can be controlled through filtering from WM, 0.1 dB penalty, PtP WDM PON operates without FEC, 8 PtP WDM channels (seven interferers).
+
+NOTE 5 – The specified penalty is valid up to a 40 km optical link distance. If the actual OPP is worse than the specified value, it must be compensated by the transmitter launch power increase up to the limits of the mean launch power maximum. Maximum OPP value assumes the use of the shared spectrum band, OPP related to Raman impacts for the expanded spectrum are determined by application.
+
+NOTE 6 – See clause 9.4.1of [b-ITU-T G.Sup39] for additional details.
+
+NOTE 7 – The definition of In-band crosstalk tolerance and its implication on receiver sensitivity is defined in clause 3.2.2.10 of [ITU-T G.989].
+
+**Table A.3 – Optical interface parameters of line rate class 1  
+(from 1.2288 Gbit/s to 1.25 Gbit/s) upstream direction**
+
+| Item                                         | Unit   | Value                                                                        |
+|----------------------------------------------|--------|------------------------------------------------------------------------------|
+| <b>ONU transmitter (optical interface S)</b> |        |                                                                              |
+| Nominal line rate                            | Gbit/s | 1.2288 to 1.25                                                               |
+| Operating wavelength band                    | nm     | 1603-1625 (shared spectrum)<br>1524-1625 (expanded spectrum)                 |
+| Minimum tuning window                        | nm     | Based on operating wavelength band                                           |
+| Minimum operating channel spacing            | GHz    | 50                                                                           |
+| Maximum operating channel spacing            | GHz    | 200                                                                          |
+| Maximum spectral excursion                   | GHz    | +/-12.5 for 50 GHz CS<br>+/-20 for 100 GHz CS<br>+/-25 for 200 GHz CS        |
+| Maximum tuning granularity                   | GHz    | CS/20                                                                        |
+| Tx wavelength channel tuning time            | ms     | See Table 9-2                                                                |
+| Line code                                    | –      | Determined by application<br>(scrambled NRZ assumed<br>for parameter values) |
+
+**Table A.3 – Optical interface parameters of line rate class 1  
+(from 1.2288 Gbit/s to 1.25 Gbit/s) upstream direction**
+
+| Item                                                                        | Unit         | Value                                                                                                                                                                                                                                                 |       |       |       |
+|-----------------------------------------------------------------------------|--------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------|-------|-------|
+| Mask of the transmitter eye diagram                                         | –            | See clause A.1.6.2                                                                                                                                                                                                                                    |       |       |       |
+| Maximum reflectance of equipment at R/S, measured at transmitter wavelength | dB           | –6                                                                                                                                                                                                                                                    |       |       |       |
+| Minimum ORL of ODN at R/S                                                   | dB           | 32                                                                                                                                                                                                                                                    |       |       |       |
+| ODN Class                                                                   |              | N1                                                                                                                                                                                                                                                    | N2    | E1    | E2    |
+| Mean channel launch power minimum (at R/S) without FEC                      | dBm          | +3                                                                                                                                                                                                                                                    | +3    | +3    | +3    |
+| Mean channel launch power minimum (at R/S) with FEC                         | dBm          | 0                                                                                                                                                                                                                                                     | 0     | 0     | 0     |
+| Mean channel launch power maximum (at R/S) without FEC                      | dBm          | +8                                                                                                                                                                                                                                                    | +8    | +8    | +8    |
+| Mean channel launch power minimum (at R/S) with FEC                         | dBm          | +5                                                                                                                                                                                                                                                    | +5    | +5    | +5    |
+| Minimum extinction ratio (Note 1)                                           | dB           | 8.2                                                                                                                                                                                                                                                   |       |       |       |
+| Tolerance to reflected optical power                                        | dB           | –15                                                                                                                                                                                                                                                   |       |       |       |
+| Dispersion range (Note 2)                                                   | ps/nm        | $0 \text{ to } \frac{0.092 \times \lambda}{4} \left[ 1 - \left( \frac{1300}{\lambda} \right)^2 \right] \times 20$ (DD20),<br>$0 \text{ to } \frac{0.092 \times \lambda}{4} \left[ 1 - \left( \frac{1300}{\lambda} \right)^2 \right] \times 40$ (DD40) |       |       |       |
+| Minimum side mode suppression ratio (Note 3)                                | dB           | 30                                                                                                                                                                                                                                                    |       |       |       |
+| Maximum upstream out-of-band optical PSD (Note 4)                           | dBm (15 GHz) | –58.6                                                                                                                                                                                                                                                 |       |       |       |
+| Maximum upstream out-of-channel optical PSD – OOC1 (Note 5)                 | dBm (15 GHz) | –33.7 for 50 GHz CS<br>–37.5 for 100 GHz CS<br>–41.4 for 200 GHz CS                                                                                                                                                                                   |       |       |       |
+| Maximum upstream out-of-channel optical PSD – OOC2 (Note 5)                 | dBm (15 GHz) | –54.5                                                                                                                                                                                                                                                 |       |       |       |
+| Jitter transfer                                                             | –            | See clause A.1.6.3                                                                                                                                                                                                                                    |       |       |       |
+| Jitter generation                                                           | –            | See clause A.1.6.3                                                                                                                                                                                                                                    |       |       |       |
+| OLT receiver (optical interface R)                                          |              |                                                                                                                                                                                                                                                       |       |       |       |
+| Maximum OPP (Note 6)<br>– with Raman effects                                | dB           | 1.5 (without FEC)                                                                                                                                                                                                                                     |       |       |       |
+|                                                                             |              | 1.0 (with FEC on)                                                                                                                                                                                                                                     |       |       |       |
+| Maximum reflectance of equipment at S/R-CG, measured at receiver wavelength | dB           | –20                                                                                                                                                                                                                                                   |       |       |       |
+| ODN Class                                                                   |              | N1                                                                                                                                                                                                                                                    | N2    | E1    | E2    |
+| Sensitivity (at S/R-CG) @ BER=10 <sup>–12</sup>                             | dBm          | –27.5                                                                                                                                                                                                                                                 | –29.5 | –31.5 | –33.5 |
+| Sensitivity (at S/R-CG) @ BER=10 <sup>–4</sup> (Note 7)                     | dBm          | –30.0                                                                                                                                                                                                                                                 | –32.0 | –34.0 | –36.0 |
+| Overload (at S/R-CG) @ BER=10 <sup>–12</sup>                                | dBm          | –6                                                                                                                                                                                                                                                    | –8    | –10   | –12   |
+| Overload (at S/R-CG) @ BER=10 <sup>–4</sup> (Note 7)                        | dBm          | –9                                                                                                                                                                                                                                                    | –11   | –13   | –15   |
+
+**Table A.3 – Optical interface parameters of line rate class 1  
+(from 1.2288 Gbit/s to 1.25 Gbit/s) upstream direction**
+
+| Item                                 | Unit          | Value              |
+|--------------------------------------|---------------|--------------------|
+| In-band crosstalk tolerance          | dB<br>(15GHz) | 34.8               |
+| Consecutive identical digit immunity | bit           | 72                 |
+| Jitter tolerance                     | –             | See clause A.1.6.3 |
+
+NOTE 1 – A lower extinction ratio must be compensated by a larger transmitter launch power within the limits of the "Mean launch power maximum" value.
+
+NOTE 2 – This formula (see clause 6.10 of [ITU-T G.652]) is used instead of the worst case value due to the large variation of dispersion within the PtP WDM PON wavelength band. This allows implementers to build devices only to the desired dispersion specification.  $\lambda$  is the longest possible wavelength in each channel, in nanometre units, considering the spectral excursion.
+
+NOTE 3 – For upstream, SMSR is measured on the laser output, before any filtering. This prevents a significant mode partition noise penalty. Other limitations on OOB and OOC PSD still apply to the R/S reference point.
+
+NOTE 4 – This value is based the following assumptions: OOB impact from PtP WDM PON on TWDM PON can be controlled through appropriate filtering, 0.1 dB penalty, TWDM PON operates with FEC, and 8 PtP WDM channels (seven interferers).
+
+NOTE 5 – This value is based the following assumptions: 1.0 dB penalty, PtP WDM PON operates without FEC, and eight PtP WDM channels (seven interferers). In some implementations, this requirement may be achieved by more tightly regulating the Tx output power (lowering the maximum level while maintaining the minimum level).
+
+NOTE 6 – The specified penalty is valid up to a 40 km optical link distance. If the actual OPP is worse than the specified value, it must be compensated by the transmitter launch power increase up to the limits of the mean launch power maximum. Maximum OPP value assumes the use of the shared spectrum band, OPP related to Raman impacts for the expanded spectrum are determined by application.
+
+NOTE 7 – See clause 9.4.1 of [b-ITU-T G.Sup39] for additional details.
+
+NOTE 8 – The definition of In-band crosstalk tolerance and its implication on receiver sensitivity is defined in clause 3.2.2.10 of [ITU-T G.989].
+
+##### A.1.5.3 Optical interface parameters for line rate class 2
+
+The following optical interface parameter tables are applicable for up to 40 km fibre length and a minimum of 4 PtP WDM channels.
+
+**Table A.4 – Optical interface parameters for line rate class 2  
+(from 2.4576 Gbit/s to 2.666 Gbit/s) downstream direction**
+
+| Item                                                                                 | Unit            | Value                                                                                                                                                                                                                                                                           |    |     |     |
+|--------------------------------------------------------------------------------------|-----------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----|-----|-----|
+| <b>OLT transmitter (optical interface S)</b>                                         |                 |                                                                                                                                                                                                                                                                                 |    |     |     |
+| Nominal line rate                                                                    | Gbit/s          | 2.4576 to 2.666                                                                                                                                                                                                                                                                 |    |     |     |
+| Operating wavelength band                                                            | nm              | 1603-1625 (shared spectrum)<br>1524-1625 (expanded spectrum)                                                                                                                                                                                                                    |    |     |     |
+| Minimum operating channel spacing                                                    | GHz             | 50                                                                                                                                                                                                                                                                              |    |     |     |
+| Maximum operating channel spacing                                                    | GHz             | 200                                                                                                                                                                                                                                                                             |    |     |     |
+| Maximum spectral excursion                                                           | GHz             | +/-12.5 for 50 GHz CS<br>+/-20 for 100 GHz CS<br>+/-25 for 200 GHz CS                                                                                                                                                                                                           |    |     |     |
+| Line code                                                                            | –               | Determined by application<br>(scrambled NRZ assumed<br>for parameter values)                                                                                                                                                                                                    |    |     |     |
+| Mask of the transmitter eye diagram                                                  | –               | See clause A.1.6.2                                                                                                                                                                                                                                                              |    |     |     |
+| Maximum reflectance of equipment<br>at S/R-CG, measured at transmitter<br>wavelength | dB              | NA                                                                                                                                                                                                                                                                              |    |     |     |
+| Minimum ORL of ODN at S/R-CG                                                         | dB              | 32                                                                                                                                                                                                                                                                              |    |     |     |
+| ODN Class                                                                            |                 | N1                                                                                                                                                                                                                                                                              | N2 | E1  | E2  |
+| Mean channel launch power minimum<br>(at S/R-CG) without FEC                         | dBm             | +3                                                                                                                                                                                                                                                                              | +5 | FFS | FFS |
+| Mean channel launch power minimum<br>(at S/R-CG) with FEC                            |                 | 0                                                                                                                                                                                                                                                                               | +2 | +4  | +6  |
+| Mean channel launch power maximum<br>(at S/R-CG) without FEC                         | dBm             | +7                                                                                                                                                                                                                                                                              | +9 | FFS | FFS |
+| Mean channel launch power maximum<br>(at S/R-CG) with FEC                            |                 | +4                                                                                                                                                                                                                                                                              | +6 | +8  | +10 |
+| Maximum downstream WNE-PSD                                                           | dBm<br>(15 GHz) | FFS                                                                                                                                                                                                                                                                             |    |     |     |
+| Minimum extinction ratio (Note 1)                                                    | dB              | 8.2                                                                                                                                                                                                                                                                             |    |     |     |
+| Tolerance to reflected optical power                                                 | dB              | –15                                                                                                                                                                                                                                                                             |    |     |     |
+| Dispersion Range (Note 2)                                                            | ps/nm           | $0 \text{ to } \frac{0.092 \times \lambda}{4} \left[ 1 - \left( \frac{1300}{\lambda} \right)^2 \right] \times 20 \quad (\text{DD20}),$<br>$0 \text{ to } \frac{0.092 \times \lambda}{4} \left[ 1 - \left( \frac{1300}{\lambda} \right)^2 \right] \times 40 \quad (\text{DD40})$ |    |     |     |
+| Minimum side mode suppression ratio<br>(at S/R-CP)                                   | dB              | 30                                                                                                                                                                                                                                                                              |    |     |     |
+| Maximum downstream per channel out-of-<br>band optical PSD (Note 3)                  | dBm<br>(15 GHz) | –46.5                                                                                                                                                                                                                                                                           |    |     |     |
+| Maximum downstream per channel out-of-<br>channel optical PSD (Note 4)               | dBm<br>(15 GHz) | –52.1                                                                                                                                                                                                                                                                           |    |     |     |
+| Jitter generation                                                                    | –               | See clause A.1.6.3                                                                                                                                                                                                                                                              |    |     |     |
+
+**Table A.4 – Optical interface parameters for line rate class 2  
+(from 2.4576 Gbit/s to 2.666 Gbit/s) downstream direction**
+
+| Item                                                                                                                                                                                                                                                                                                                                                                                                      | Unit           | Value              |     |     |     |  |  |  |  |
+|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------|--------------------|-----|-----|-----|--|--|--|--|
+| <b>ONU receiver (optical interface R)</b>                                                                                                                                                                                                                                                                                                                                                                 |                |                    |     |     |     |  |  |  |  |
+| Maximum OPP (Note 5)<br>– with Raman effects                                                                                                                                                                                                                                                                                                                                                              | dB             | 2.0 (without FEC)  |     |     |     |  |  |  |  |
+|                                                                                                                                                                                                                                                                                                                                                                                                           |                | 1.0 (with FEC)     |     |     |     |  |  |  |  |
+| Maximum reflectance of equipment at R/S, measured at receiver wavelength                                                                                                                                                                                                                                                                                                                                  | dB             | –20                |     |     |     |  |  |  |  |
+| Rx wavelength channel tuning time                                                                                                                                                                                                                                                                                                                                                                         |                | See Table 9-2      |     |     |     |  |  |  |  |
+| Maximum tuning granularity                                                                                                                                                                                                                                                                                                                                                                                | GHz            | CS/20              |     |     |     |  |  |  |  |
+| ODN Class                                                                                                                                                                                                                                                                                                                                                                                                 |                | N1                 | N2  | E1  | E2  |  |  |  |  |
+| Sensitivity (at R/S) @ BER=10 <sup>-12</sup>                                                                                                                                                                                                                                                                                                                                                              | dBm            | –28                | –28 | FFS | FFS |  |  |  |  |
+| Sensitivity (at R/S) @ BER=10 <sup>-4</sup> (Note 6)                                                                                                                                                                                                                                                                                                                                                      | dBm            | –30                | –30 | –30 | –30 |  |  |  |  |
+| Overload (at R/S) @ BER=10 <sup>-12</sup>                                                                                                                                                                                                                                                                                                                                                                 | dBm            | –7                 | –7  | FFS | FFS |  |  |  |  |
+| Overload (at R/S) @ BER=10 <sup>-4</sup> (Note 6)                                                                                                                                                                                                                                                                                                                                                         | dBm            | –10                | –10 | –10 | –10 |  |  |  |  |
+| In-band crosstalk tolerance                                                                                                                                                                                                                                                                                                                                                                               | dB<br>(15 GHz) | 43.3               |     |     |     |  |  |  |  |
+| Consecutive identical digit immunity                                                                                                                                                                                                                                                                                                                                                                      | bit            | 72                 |     |     |     |  |  |  |  |
+| Jitter tolerance                                                                                                                                                                                                                                                                                                                                                                                          | –              | See clause A.1.6.3 |     |     |     |  |  |  |  |
+| NOTE 1 – A lower extinction ratio must be compensated by a larger transmitter launch power within the limits of the "Mean launch power maximum" value.                                                                                                                                                                                                                                                    |                |                    |     |     |     |  |  |  |  |
+| NOTE 2 – This formula (see clause 6.10 of [ITU-T G.652]) is used instead of the worst case value due to the large variation of dispersion within the PtP WDM PON wavelength band. This allows implementers to build devices only to the desired dispersion specification. $\lambda$ is the longest possible wavelength in each channel, in nanometre units, considering the spectral excursion.           |                |                    |     |     |     |  |  |  |  |
+| NOTE 3 – This value is based the following assumptions: OOB impact from PtP WDM PON on TWDM PON can be controlled through appropriate filtering, 0.1 dB penalty, TWDM PON operates with FEC and 8 PtP WDM channels (seven interferers).                                                                                                                                                                   |                |                    |     |     |     |  |  |  |  |
+| NOTE 4 – This value is based the following assumptions: OOC in downstream can be controlled through filtering from WM, 0.1 dB penalty, PtP WDM PON operates without FEC, eight PtP WDM channels (seven interferers).                                                                                                                                                                                      |                |                    |     |     |     |  |  |  |  |
+| NOTE 5 – The specified penalty is valid up to a 40 km optical link distance. If the actual OPP is worse than the specified value, it must be compensated by the transmitter launch power increase up to the limits of the mean launch power maximum. Maximum OPP value assumes the use of the shared spectrum band, OPP related to Raman impacts for the expanded spectrum are determined by application. |                |                    |     |     |     |  |  |  |  |
+| NOTE 6 – See clause 9.4.1 of [b-ITU-T G.Sup39] for additional details.                                                                                                                                                                                                                                                                                                                                    |                |                    |     |     |     |  |  |  |  |
+| NOTE 7 – The definition of In-band crosstalk tolerance and its implication on receiver sensitivity is defined in clause 3.2.2.10 of [ITU-T G.989].                                                                                                                                                                                                                                                        |                |                    |     |     |     |  |  |  |  |
+
+**Table A.5 – Optical interface parameters for line rate class 2  
+(from 2.4576 Gbit/s to 2.666 Gbit/s) upstream direction**
+
+| Item                                                                                    | Unit            | Value                                                                                                                                                                                                                                                 |    |    |    |
+|-----------------------------------------------------------------------------------------|-----------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----|----|----|
+| <b>ONU transmitter (optical interface S)</b>                                            |                 |                                                                                                                                                                                                                                                       |    |    |    |
+| Nominal line rate                                                                       | Gbit/s          | 2.4576 to 2.666                                                                                                                                                                                                                                       |    |    |    |
+| Operating wavelength band                                                               | nm              | 1603-1625 (shared spectrum)<br>1524-1625 (expanded spectrum)                                                                                                                                                                                          |    |    |    |
+| Minimum tuning window                                                                   | nm              | Based on operating wavelength band                                                                                                                                                                                                                    |    |    |    |
+| Minimum operating channel spacing                                                       | GHz             | 50                                                                                                                                                                                                                                                    |    |    |    |
+| Maximum operating channel spacing                                                       | GHz             | 200                                                                                                                                                                                                                                                   |    |    |    |
+| Maximum spectral excursion                                                              | GHz             | +/-12.5 for 50 GHz CS<br>+/-20 for 100 GHz CS<br>+/-25 for 200 GHz CS                                                                                                                                                                                 |    |    |    |
+| Maximum tuning granularity                                                              | GHz             | CS/20                                                                                                                                                                                                                                                 |    |    |    |
+| Tx wavelength channel tuning time                                                       | ms              | See Table 9-2                                                                                                                                                                                                                                         |    |    |    |
+| Line code                                                                               | –               | Determined by application<br>(scrambled NRZ assumed<br>for parameter values)                                                                                                                                                                          |    |    |    |
+| Mask of the transmitter eye diagram                                                     | –               | See clause A.1.6.2                                                                                                                                                                                                                                    |    |    |    |
+| Maximum reflectance of equipment at R/S,<br>measured at transmitter wavelength          | dB              | -6                                                                                                                                                                                                                                                    |    |    |    |
+| Minimum ORL of ODN at R/S                                                               | dB              | 32                                                                                                                                                                                                                                                    |    |    |    |
+| ODN Class                                                                               |                 | N1                                                                                                                                                                                                                                                    | N2 | E1 | E2 |
+| Mean channel launch power minimum<br>(at R/S) without FEC                               | dBm             | +3                                                                                                                                                                                                                                                    | +3 | +3 | +3 |
+| Mean channel launch power minimum<br>(at R/S) with FEC                                  | dBm             | +0                                                                                                                                                                                                                                                    | +0 | +0 | +0 |
+| Mean channel launch power maximum<br>(at R/S) without FEC                               | dBm             | +8                                                                                                                                                                                                                                                    | +8 | +8 | +8 |
+| Mean channel launch power maximum<br>(at R/S) with FEC                                  | dBm             | +5                                                                                                                                                                                                                                                    | +5 | +5 | +5 |
+| Minimum extinction ratio (Note 1)                                                       | dB              | 8.2                                                                                                                                                                                                                                                   |    |    |    |
+| Tolerance to reflected optical power                                                    | dB              | -15                                                                                                                                                                                                                                                   |    |    |    |
+| Dispersion range (Note 2)                                                               | ps/nm           | $0 \text{ to } \frac{0.092 \times \lambda}{4} \left[ 1 - \left( \frac{1300}{\lambda} \right)^2 \right] \times 20$ (DD20),<br>$0 \text{ to } \frac{0.092 \times \lambda}{4} \left[ 1 - \left( \frac{1300}{\lambda} \right)^2 \right] \times 40$ (DD40) |    |    |    |
+| Minimum side mode suppression ratio<br>(Note 3)                                         | dB              | 30                                                                                                                                                                                                                                                    |    |    |    |
+| Maximum upstream out-of-band optical<br>PSD (Assuming eight Ch PtP WDM PON)<br>(Note 4) | dBm<br>(15 GHz) | -58.6                                                                                                                                                                                                                                                 |    |    |    |
+| Maximum upstream out-of-channel optical<br>PSD – OOC1 (Note 5)                          | dBm<br>(15 GHz) | -33.7 for 50 GHz CS<br>-37.5 for 100 GHz CS<br>-41.4 for 200 GHz CS                                                                                                                                                                                   |    |    |    |
+
+**Table A.5 – Optical interface parameters for line rate class 2  
+(from 2.4576 Gbit/s to 2.666 Gbit/s) upstream direction**
+
+| Item                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   | Unit            | Value              |     |       |       |
+|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------|--------------------|-----|-------|-------|
+| Maximum upstream out-of-channel optical PSD – OOC2 (Note 5)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            | dBm<br>(15 GHz) | –54.5              |     |       |       |
+| Jitter transfer                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |                 | See clause A.1.6.3 |     |       |       |
+| Jitter generation                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      | –               | See clause A.1.6.3 |     |       |       |
+| OLT receiver (optical interface R)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |                 |                    |     |       |       |
+| ODN Class                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |                 | N1                 | N2  | E1    | E2    |
+| Maximum OPP – without FEC                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              | dB              | 2.0                | 2.0 | 2.0   | 2.0   |
+| Maximum OPP – with FEC ON (Note 6)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |                 | 1.0                | 1.0 | 1.5   | 1.5   |
+| Maximum reflectance of equipment at S/R-CG, measured at receiver wavelength                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            | dB              | –20                |     |       |       |
+| ODN Class                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |                 | N1                 | N2  | E1    | E2    |
+| Sensitivity (at S/R-CG) @ BER=10 <sup>–12</sup>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        | dBm             | –28                | –30 | –32   | –34   |
+| Sensitivity (at S/R-CG) @ BER=10 <sup>–4</sup> (Note 7)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                | dBm             | –30                | –32 | –34.5 | –36.5 |
+| Overload (at S/R-CG) @ BER=10 <sup>–12</sup>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           | dBm             | –6                 | –8  | –10   | –12   |
+| Overload (at S/R-CG) @ BER=10 <sup>–4</sup> (Note 7)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   | dBm             | –9                 | –11 | –13   | –15   |
+| In-band crosstalk tolerance                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            | dB<br>(15 GHz)  | 34.8               |     |       |       |
+| Consecutive identical digit immunity                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   | bit             | 72                 |     |       |       |
+| Jitter tolerance                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       | –               | See clause A.1.6.3 |     |       |       |
+| NOTE 1 – A lower extinction ratio must be compensated by a larger transmitter launch power within the limits of the "Mean launch power maximum" value.<br>NOTE 2 – This formula (see clause 6.10 of [ITU-T G.652]) is used instead of the worst case value due to the large variation of dispersion within the PtP WDM PON wavelength band. This allows implementers to build devices only to the desired dispersion specification. $\lambda$ is the longest possible wavelength in each channel, in nanometre units, considering the spectral excursion.<br>NOTE 3 – For upstream, SMSR is measured on the laser output, before any filtering. This prevents a significant mode partition noise penalty. Other limitations on OOB and OOC PSD still apply to the R/S reference point.<br>NOTE 4 – This value is based the following assumptions: OOB impact from PtP WDM PON on TWDM PON can be controlled through appropriate filtering, 0.1 dB penalty, TWDM PON operates with FEC and eight PtP WDM channels (seven interferers).<br>NOTE 5 – This value is based the following assumptions: 1.0 dB penalty, PtP WDM PON operates without FEC, and eight PtP WDM channels (7 interferers). In some implementations, this requirement may be achieved by more tightly regulating the Tx output power (lowering the maximum level while maintaining the minimum level).<br>NOTE 6 – The specified penalty is valid up to a 40 km optical link distance. If the actual OPP is worse than the specified value, it must be compensated by the transmitter launch power increase up to the limits of the Mean launch power maximum. Maximum OPP value assumes the use of the shared spectrum band, OPP related to Raman impacts for the expanded spectrum are determined by application.<br>NOTE 7 – See clause 9.4.1 of [b-ITU-T G.Sup39] for additional details.<br>NOTE 8 – The definition of In-band crosstalk tolerance and its implication on receiver sensitivity is defined in clause 3.2.2.10 of [ITU-T G.989]. |                 |                    |     |       |       |
+
+##### A.1.5.4 Optical interface parameters for line rate class 3
+
+The following optical interface parameter tables are applicable for up to 40 km fibre length and a minimum of 4 PtP WDM channels.
+
+**Table A.6 – Optical interface parameters for line rate class 3  
+(from 6.144 Gbit/s to 11.09 Gbit/s) downstream direction**
+
+| Item                                                                                                   | Unit            | Value                                                                                                                                                                                                                                                                        |      |       |       |
+|--------------------------------------------------------------------------------------------------------|-----------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------|-------|-------|
+| <b>OLT transmitter (optical interface S)</b>                                                           |                 |                                                                                                                                                                                                                                                                              |      |       |       |
+| Nominal line rate                                                                                      | Gbit/s          | 6.144 to 11.09                                                                                                                                                                                                                                                               |      |       |       |
+| Operating wavelength band                                                                              | nm              | 1603-1625 (shared spectrum)<br>1524-1625 (expanded spectrum)                                                                                                                                                                                                                 |      |       |       |
+| Minimum operating channel spacing                                                                      | GHz             | 50                                                                                                                                                                                                                                                                           |      |       |       |
+| Maximum operating channel spacing                                                                      | GHz             | 200                                                                                                                                                                                                                                                                          |      |       |       |
+| Maximum spectral excursion                                                                             | GHz             | +/–12.5 for 50 GHz CS<br>+/–20 for 100 GHz CS<br>+/–25 for 200 GHz CS                                                                                                                                                                                                        |      |       |       |
+| Line code                                                                                              | –               | Determined by application<br>(scrambled NRZ assumed<br>for parameter values)                                                                                                                                                                                                 |      |       |       |
+| Mask of the transmitter eye diagram                                                                    | –               | See clause A.1.6.2                                                                                                                                                                                                                                                           |      |       |       |
+| Maximum reflectance of equipment<br>at S/R-CG, measured at transmitter<br>wavelength                   | dB              | NA                                                                                                                                                                                                                                                                           |      |       |       |
+| Minimum ORL of ODN at S/R-CG                                                                           | dB              | 32                                                                                                                                                                                                                                                                           |      |       |       |
+| ODN Class                                                                                              |                 | N1                                                                                                                                                                                                                                                                           | N2   | E1    | E2    |
+| Mean channel launch power minimum<br>(at S/R-CG) without FEC                                           | dBm             | +8                                                                                                                                                                                                                                                                           | FFS  | FFS   | FFS   |
+| Mean channel launch power minimum<br>(at S/R-CG) with FEC                                              | dBm             | +3.0                                                                                                                                                                                                                                                                         | +5.0 | +7.0  | +9.0  |
+| Mean channel launch power maximum<br>(at S/R-CG) without FEC                                           | dBm             | +11                                                                                                                                                                                                                                                                          | FFS  | FFS   | FFS   |
+| Mean channel launch power maximum<br>(at S/R-CG) with FEC                                              | dBm             | +7.0                                                                                                                                                                                                                                                                         | +9.0 | +11.0 | +11.0 |
+| Maximum downstream WNE-PSD                                                                             | dBm<br>(15 GHz) | FFS                                                                                                                                                                                                                                                                          |      |       |       |
+| Minimum extinction ratio (Note 1)                                                                      | dB              | 8.2                                                                                                                                                                                                                                                                          |      |       |       |
+| Tolerance to reflected optical power                                                                   | dB              | –15                                                                                                                                                                                                                                                                          |      |       |       |
+| Dispersion range (Note 2)                                                                              | ps/nm           | $0 \text{ to } \frac{0.092 \times \lambda}{4} \left[ 1 - \left( \frac{1300}{\lambda} \right)^2 \right] \times 20 \quad \text{(DD20),}$ $0 \text{ to } \frac{0.092 \times \lambda}{4} \left[ 1 - \left( \frac{1300}{\lambda} \right)^2 \right] \times 40 \quad \text{(DD40)}$ |      |       |       |
+| Minimum side mode suppression ratio<br>(at S/R-CP)                                                     | dB              | 30                                                                                                                                                                                                                                                                           |      |       |       |
+| Maximum downstream per channel out-of-<br>band optical PSD (Assuming eight Ch PtP<br>WDM PON) (Note 3) | dBm<br>(15 GHz) | –46.5                                                                                                                                                                                                                                                                        |      |       |       |
+
+**Table A.6 – Optical interface parameters for line rate class 3  
+(from 6.144 Gbit/s to 11.09 Gbit/s) downstream direction**
+
+| Item                                                                                               | Unit            | Value              |      |      |      |
+|----------------------------------------------------------------------------------------------------|-----------------|--------------------|------|------|------|
+| Maximum downstream per channel out-of-channel optical PSD (Assuming eight Ch PtP WDM PON) (Note 4) | dBm<br>(15 GHz) | –52.1              |      |      |      |
+| Jitter generation                                                                                  | –               | See clause A.1.6.3 |      |      |      |
+| <b>ONU receiver (optical interface R)</b>                                                          |                 |                    |      |      |      |
+| Maximum OPP (Note 5)                                                                               | dB              | 2.5 (without FEC)  |      |      |      |
+| – with Raman effects                                                                               |                 | 2.0 (with FEC)     |      |      |      |
+| Maximum reflectance of equipment at R/S, measured at receiver wavelength                           | dB              | –20                |      |      |      |
+| Rx wavelength channel tuning time                                                                  |                 | See Table 9-2      |      |      |      |
+| Maximum tuning granularity                                                                         | GHz             | CS/20              |      |      |      |
+| ODN Class                                                                                          |                 | N1                 | N2   | E1   | E2   |
+| Sensitivity (at R/S) @ BER=10 <sup>–12</sup>                                                       | dBm             | –23.5              | FFS  | FFS  | FFS  |
+| Sensitivity (at R/S) @ BER=10 <sup>–3</sup> (Note 6)                                               | dBm             | –28                | –28  | –28  | –28  |
+| Overload (at R/S) @ BER=10 <sup>–12</sup>                                                          | dBm             | –2                 | FFS  | FFS  | FFS  |
+| Overload (at R/S) @ BER=10 <sup>–3</sup> (Note 6)                                                  | dBm             | –7.0               | –7.0 | –7.0 | –9.0 |
+| In-band crosstalk tolerance                                                                        | dB<br>(15 GHz)  | 47.8               |      |      |      |
+| Consecutive identical digit immunity                                                               | bit             | 72                 |      |      |      |
+| Jitter tolerance                                                                                   | –               | See clause A.1.6.3 |      |      |      |
+
+NOTE 1 – A lower extinction ratio must be compensated by a larger transmitter launch power within the limits of the "Mean launch power maximum" value.
+
+NOTE 2 – This formula (see clause 6.10 of [ITU-T G.652]) is used instead of the worst case value due to the large variation of dispersion within the PtP WDM PON wavelength band. This allows implementers to build devices only to the desired dispersion specification.  $\lambda$  is the longest possible wavelength in each channel, in nanometre units, considering the spectral excursion.
+
+NOTE 3 – This value is based the following assumptions: OOB impact from PtP WDM PON on TWDM PON can be controlled through appropriate filtering, 0.1 dB penalty, TWDM PON operates with FEC and eight PtP WDM channels (seven interferers).
+
+NOTE 4 – This value is based the following assumptions: OOC in downstream can be controlled through filtering from WM, 0.1 dB penalty, PtP WDM PON operates without FEC, eight PtP WDM channels (seven interferers).
+
+NOTE 5 – The specified penalty is valid up to a 40km optical link distance. If the actual OPP is worse than the specified value, it must be compensated by the transmitter launch power increase up to the limits of the Mean launch power maximum. Maximum OPP value assumes the use of the shared spectrum band, OPP related to Raman impacts for the expanded spectrum are determined by application.
+
+NOTE 6 – See clause 9.4.1 of [b-ITU-T G.Sup39] for additional details.
+
+NOTE 7 – The definition of In-band crosstalk tolerance and its implication on receiver sensitivity is defined in clause 3.2.2.10 of [ITU-T G.989].
+
+**Table A.7 – Optical interface parameters for line rate class 3  
+(from 6.144 Gbit/s to 11.09 Gbit/s) upstream direction**
+
+| Item                                                                        | Unit            | Value                                                                                                                                                                                                                                                 |      |      |      |
+|-----------------------------------------------------------------------------|-----------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------|------|------|
+| <b>ONU transmitter (optical interface S)</b>                                |                 |                                                                                                                                                                                                                                                       |      |      |      |
+| Nominal line rate                                                           | Gbit/s          | 6.144 to 11.09                                                                                                                                                                                                                                        |      |      |      |
+| Operating wavelength band                                                   | nm              | 1603-1625 (shared spectrum)<br>1524-1625 (expanded spectrum)                                                                                                                                                                                          |      |      |      |
+| Minimum tuning window                                                       | nm              | Based on operating wavelength band                                                                                                                                                                                                                    |      |      |      |
+| Minimum operating channel spacing                                           | GHz             | 50                                                                                                                                                                                                                                                    |      |      |      |
+| Maximum operating channel spacing                                           | GHz             | 200                                                                                                                                                                                                                                                   |      |      |      |
+| Maximum spectral excursion                                                  | GHz             | +/-12.5 for 50 GHz CS<br>+/-20 for 100 GHz CS<br>+/-25 for 200 GHz CS                                                                                                                                                                                 |      |      |      |
+| Maximum tuning granularity                                                  | GHz             | CS/20                                                                                                                                                                                                                                                 |      |      |      |
+| Tx wavelength channel tuning time                                           | ms              | See Table 9-2                                                                                                                                                                                                                                         |      |      |      |
+| Line code                                                                   | –               | Determined by application<br>(scrambled NRZ assumed<br>for parameter values)                                                                                                                                                                          |      |      |      |
+| Mask of the transmitter eye diagram                                         | –               | See clause A.1.6.2                                                                                                                                                                                                                                    |      |      |      |
+| Maximum reflectance of equipment at R/S, measured at transmitter wavelength | dB              | -6                                                                                                                                                                                                                                                    |      |      |      |
+| Minimum ORL of ODN at R/S                                                   | dB              | 32                                                                                                                                                                                                                                                    |      |      |      |
+| ODN Class                                                                   |                 | N1                                                                                                                                                                                                                                                    | N2   | E1   | E2   |
+| Mean channel launch power minimum (at R/S) without FEC                      | dBm             | +3                                                                                                                                                                                                                                                    | +3   | +3   | FFS  |
+| Mean channel launch power minimum (at R/S) with FEC                         | dBm             | +4.0                                                                                                                                                                                                                                                  | +4.0 | +4.0 | +4.0 |
+| Mean channel launch power maximum (at R/S) without FEC                      | dBm             | +8                                                                                                                                                                                                                                                    | +8   | +8   | FFS  |
+| Mean channel launch power maximum (at R/S) with FEC                         | dBm             | +9.0                                                                                                                                                                                                                                                  | +9.0 | +9.0 | +9.0 |
+| Minimum extinction ratio (Note 1)                                           | dB              | 8.2                                                                                                                                                                                                                                                   |      |      |      |
+| Tolerance to reflected optical power                                        | dB              | -15                                                                                                                                                                                                                                                   |      |      |      |
+| Dispersion range (Note 2)                                                   | ps/nm           | $0 \text{ to } \frac{0.092 \times \lambda}{4} \left[ 1 - \left( \frac{1300}{\lambda} \right)^2 \right] \times 20$ (DD20),<br>$0 \text{ to } \frac{0.092 \times \lambda}{4} \left[ 1 - \left( \frac{1300}{\lambda} \right)^2 \right] \times 40$ (DD40) |      |      |      |
+| Minimum side mode suppression ratio (Note 3)                                | dB              | 30                                                                                                                                                                                                                                                    |      |      |      |
+| Maximum upstream out-of-band optical PSD (Note 4)                           | dBm<br>(15 GHz) | -58.6                                                                                                                                                                                                                                                 |      |      |      |
+| Maximum upstream out-of-channel optical PSD – OOC1 (Note 5)                 | dBm<br>(15 GHz) | -33.7 for 50GHz CS<br>-37.5 for 100 GHz CS<br>-41.4 for 200 GHz CS                                                                                                                                                                                    |      |      |      |
+
+**Table A.7 – Optical interface parameters for line rate class 3  
+(from 6.144 Gbit/s to 11.09 Gbit/s) upstream direction**
+
+| Item                                                                                                                                                                                                                                                                                                                                                                                                      | Unit            | Value              |       |       |     |  |  |  |  |
+|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------|--------------------|-------|-------|-----|--|--|--|--|
+| Maximum upstream out-of-channel optical PSD – OOC2 (Note 5)                                                                                                                                                                                                                                                                                                                                               | dBm<br>(15 GHz) | -54.5              |       |       |     |  |  |  |  |
+| Jitter transfer                                                                                                                                                                                                                                                                                                                                                                                           |                 | See clause A.1.6.3 |       |       |     |  |  |  |  |
+| Jitter generation                                                                                                                                                                                                                                                                                                                                                                                         | –               | See clause A.1.6.3 |       |       |     |  |  |  |  |
+| <b>OLT receiver (optical interface R)</b>                                                                                                                                                                                                                                                                                                                                                                 |                 |                    |       |       |     |  |  |  |  |
+| ODN Class                                                                                                                                                                                                                                                                                                                                                                                                 |                 | N1                 | N2    | E1    | E2  |  |  |  |  |
+| Maximum OPP – without FEC                                                                                                                                                                                                                                                                                                                                                                                 | dB              | 2.5                | 2.5   | 2.5   | 2.5 |  |  |  |  |
+| Maximum OPP – with FEC ON (Note 6)                                                                                                                                                                                                                                                                                                                                                                        |                 | 1.5                | 1.5   | 2.0   | 2.0 |  |  |  |  |
+| Maximum reflectance of equipment at S/R-CG, measured at receiver wavelength                                                                                                                                                                                                                                                                                                                               | dB              | -20                |       |       |     |  |  |  |  |
+| ODN Class                                                                                                                                                                                                                                                                                                                                                                                                 |                 | N1                 | N2    | E1    | E2  |  |  |  |  |
+| Sensitivity (at S/R-CG) @ BER=10 <sup>-12</sup>                                                                                                                                                                                                                                                                                                                                                           | dBm             | -28.5              | -30.5 | -32.5 | FFS |  |  |  |  |
+| Sensitivity (at S/R-CG) @ BER=10 <sup>-3</sup> (Note 7)                                                                                                                                                                                                                                                                                                                                                   | dBm             | -26.5              | -28.5 | -31.0 | NA  |  |  |  |  |
+| Overload (at S/R-CG) @ BER=10 <sup>-12</sup>                                                                                                                                                                                                                                                                                                                                                              | dBm             | -6                 | -8    | -10   | FFS |  |  |  |  |
+| Overload (at S/R-CG) @ BER=10 <sup>-3</sup> (Note 7)                                                                                                                                                                                                                                                                                                                                                      | dBm             | -5.0               | -7.0  | -9.0  | NA  |  |  |  |  |
+| In-band crosstalk tolerance                                                                                                                                                                                                                                                                                                                                                                               | dB<br>(15 GHz)  | 34.8               |       |       |     |  |  |  |  |
+| Consecutive identical digit immunity                                                                                                                                                                                                                                                                                                                                                                      | bit             | 72                 |       |       |     |  |  |  |  |
+| Jitter tolerance                                                                                                                                                                                                                                                                                                                                                                                          | –               | See clause A.1.6.3 |       |       |     |  |  |  |  |
+| NOTE 1 – A lower extinction ratio must be compensated by a larger transmitter launch power within the limits of the "Mean launch power maximum" value.                                                                                                                                                                                                                                                    |                 |                    |       |       |     |  |  |  |  |
+| NOTE 2 – This formula (see clause 6.10 of [ITU-T G.652]) is used instead of the worst case value due to the large variation of dispersion within the PtP WDM PON wavelength band. This allows implementers to build devices only to the desired dispersion specification. $\lambda$ is the longest possible wavelength in each channel, in nanometre units, considering the spectral excursion.           |                 |                    |       |       |     |  |  |  |  |
+| NOTE 3 – For upstream at the ONU, SMSR is measured on the laser output, before any filtering. This prevents a significant mode partition noise penalty. Other limitations on OOB and OOC power still apply to the R/S reference point.                                                                                                                                                                    |                 |                    |       |       |     |  |  |  |  |
+| NOTE 4 – This value is based the following assumptions: OOB impact from PtP WDM PON on TWDM PON can be controlled through appropriate filtering, 0.1 dB penalty, TWDM PON operates with FEC and eight PtP WDM channels (seven interferers).                                                                                                                                                               |                 |                    |       |       |     |  |  |  |  |
+| NOTE 5 – This value is based the following assumptions: 1.0 dB penalty, PtP WDM PON operates without FEC, and eight PtP WDM channels (seven interferers). In some implementations, this requirement may be achieved by more tightly regulating the Tx output power (lowering the maximum level while maintaining the minimum level).                                                                      |                 |                    |       |       |     |  |  |  |  |
+| NOTE 6 – The specified penalty is valid up to a 40 km optical link distance. If the actual OPP is worse than the specified value, it must be compensated by the transmitter launch power increase up to the limits of the mean launch power maximum. Maximum OPP value assumes the use of the shared spectrum band, OPP related to Raman impacts for the expanded spectrum are determined by application. |                 |                    |       |       |     |  |  |  |  |
+| NOTE 7 – See clause 9.4.1 of [b-ITU-T G.Sup39] for additional details.                                                                                                                                                                                                                                                                                                                                    |                 |                    |       |       |     |  |  |  |  |
+| NOTE 8 – The definition of In-band crosstalk tolerance and its implication on receiver sensitivity is                                                                                                                                                                                                                                                                                                     |                 |                    |       |       |     |  |  |  |  |
+
+**Table A.7 – Optical interface parameters for line rate class 3  
+(from 6.144 Gbit/s to 11.09 Gbit/s) upstream direction**
+
+| Item                                         | Unit | Value |
+|----------------------------------------------|------|-------|
+| defined in clause 3.2.2.10 of [ITU-T G.989]. |      |       |
+
+#### A.1.6 Transmitter at reference point S
+
+This clause follows clause 11.1.5 unless otherwise specified below.
+
+##### A.1.6.1 Nominal central frequency
+
+The nominal single channel frequencies on which the digital coded information of the particular optical wavelength channels are modulated.
+
+The central frequencies depend on the specific WM used.
+
+##### A.1.6.2 Mask of transmitter eye diagram
+
+The parameters specifying the mask of the eye diagram, illustrated in Figure A.2, for both the OLT and ONU transmitters are shown in Table A.8.
+
+![Figure A.2: Mask of the eye diagram for OLT and ONU transmitter. The diagram shows a normalized eye diagram with a rectangular mask. The vertical axis represents signal level from -y4 to 1+y3, with markers at 1+y3, 1, y2, 0.5, y1, 0, and -y4. The horizontal axis represents time from 0 to 1. The mask is defined by vertical lines at x2 and x3, and horizontal lines at y1 and y2. The mean level of the center of logical '1' is indicated at level 1, and the mean level of the center of logical '0' is indicated at level 0. The diagram is labeled G.989.2(14)_FA.2.](0ff74f5b84bfe2303c9204d4feb60d5f_img.jpg)
+
+Figure A.2: Mask of the eye diagram for OLT and ONU transmitter. The diagram shows a normalized eye diagram with a rectangular mask. The vertical axis represents signal level from -y4 to 1+y3, with markers at 1+y3, 1, y2, 0.5, y1, 0, and -y4. The horizontal axis represents time from 0 to 1. The mask is defined by vertical lines at x2 and x3, and horizontal lines at y1 and y2. The mean level of the center of logical '1' is indicated at level 1, and the mean level of the center of logical '0' is indicated at level 0. The diagram is labeled G.989.2(14)\_FA.2.
+
+**Figure A.2 – Mask of the eye diagram for OLT and ONU transmitter**
+
+**Table A.8 – Mask of the eye diagram for OLT and ONU transmitters – numeric values**
+
+| Line rate class      | 1.25 Gbit/s | 2.5 Gbit/s | 10 Gbit/s |
+|----------------------|-------------|------------|-----------|
+| $x_3 - x_2$ (Note 1) | 0.2         | 0.2        | 0.2       |
+| $y_1, y_3, y_4$      | 0.25        | 0.25       | 0.25      |
+| $y_2$                | 0.75        | 0.75       | 0.75      |
+
+NOTE 1 –  $x_2$  and  $x_3$  of the rectangular eye mask need not be equidistant with respect to the vertical axes at 0 UI and 1 UI.
+
+NOTE 2 – The values for the 2.5 Gbit/s and the 10 Gbit/s class are taken from [ITU-T G.959.1], clause 7.2.2.14.
+
+NOTE 3 – The values for the 1.25 Gbit/s are derived from [ITU-T G.959.1], clause 7.2.2.14.
+
+##### A.1.6.3 Jitter performance
+
+Jitter performance of PtP WDM PON follows the definitions in clause 11.1.5.4 with the following modifications. Descriptions in clause 11.1.5.4 are repeated for completeness.
+
+Jitter transfer for ONU is shown in Figure A.3.
+
+![Figure A.3: Jitter transfer for ONU. A graph showing Jitter gain on the y-axis versus Frequency on the x-axis. The gain is constant at P from f_L to f_C, then decreases with a slope of -20 dB/dec until f_H. The graph is labeled G.989.2(14)_FA.3.](e91633da5160c8af51a4ace6d3347f53_img.jpg)
+
+Figure A.3: Jitter transfer for ONU. A graph showing Jitter gain on the y-axis versus Frequency on the x-axis. The gain is constant at P from f\_L to f\_C, then decreases with a slope of -20 dB/dec until f\_H. The graph is labeled G.989.2(14)\_FA.3.
+
+| Line rate class | $f_L$ (kHz) | $f_C$ (kHz) | $f_H$ (kHz) | P (dB) |
+|-----------------|-------------|-------------|-------------|--------|
+| 1               | 20          | 2000        | 20 000      | 0.1    |
+| 2               | 20          | 2000        | 20 000      | 0.1    |
+| 3               | 10          | 1000        | 80 000      | 0.1    |
+
+NOTE – These values are taken or derived from [ITU-T G.783].
+
+Figure A.3 – Jitter transfer for ONU
+
+High-band portion of sinusoidal jitter mask for jitter transfer is shown in Figure A.4.
+
+![Figure A.4: High-band portion of sinusoidal jitter mask for jitter transfer. A graph showing Input jitter amplitude on the y-axis versus Frequency on the x-axis. The amplitude is constant at A3 from 0 to f2, then decreases with a slope of -20 dB/dec until f3, where it becomes constant at A4. The graph is labeled G.989.2(14)_FA.4.](dfb7b1135e92a91d2c81546f16a50947_img.jpg)
+
+Figure A.4: High-band portion of sinusoidal jitter mask for jitter transfer. A graph showing Input jitter amplitude on the y-axis versus Frequency on the x-axis. The amplitude is constant at A3 from 0 to f2, then decreases with a slope of -20 dB/dec until f3, where it becomes constant at A4. The graph is labeled G.989.2(14)\_FA.4.
+
+| Line rate class | $A_3$ (UI) | $A_4$ (UI) | $f_2$ (kHz) | $f_3$ (kHz) |
+|-----------------|------------|------------|-------------|-------------|
+| 1               | 1.5        | 0.15       | 50          | 500         |
+| 2               | 1.5        | 0.15       | 100         | 1000        |
+| 3               | 1.5        | 0.15       | 400         | 4000        |
+
+NOTE – These values are taken from [ITU-T G.783].
+
+Figure A.4 – High-band portion of sinusoidal jitter mask for jitter transfer
+
+The Jitter tolerance mask is shown in Figure A.5.
+
+![Figure A.5: Jitter tolerance mask graph and table. The graph shows input jitter amplitude (A1, A2) vs frequency (f0, ft) with a -20 dB/dec slope. The table provides line rate class parameters.](851d99765a6fe09d94a024c53bd9fe40_img.jpg)
+
+The graph shows the jitter tolerance mask. The y-axis is 'Input jitter amplitude' with levels A1 and A2. The x-axis is 'Frequency' with markers f0 and ft. The mask is a shaded region bounded by A2 at low frequencies, a -20 dB/dec slope between f0 and ft, and A1 at high frequencies. The label 'G.989.2(14)\_FA.5' is present.
+
+| Line rate class | $f_t$ (kHz) | $f_0$ (kHz) | $A_1$ (UIp-p) | $A_2$ (UIp-p) |
+|-----------------|-------------|-------------|---------------|---------------|
+| 1               | 500         | 50          | 0.075         | 0.75          |
+| 2               | 1000        | 100         | 0.075         | 0.75          |
+| 3               | 4000        | 400         | 0.075         | 0.75          |
+
+NOTE – These values are scaled to 9.95328 Gbit/s from the values in [ITU-T G.984.2].
+
+Figure A.5: Jitter tolerance mask graph and table. The graph shows input jitter amplitude (A1, A2) vs frequency (f0, ft) with a -20 dB/dec slope. The table provides line rate class parameters.
+
+Figure A.5 – Jitter tolerance mask
+
+Jitter generation requirements are shown in Table A.9.
+
+Table A.9 – Jitter generation requirements
+
+| Line rate class | Measurement band<br>(-3 dB frequencies)<br>(Note 1) |                              | Peak-peak amplitude<br>(UI)<br>(Note 2) |
+|-----------------|-----------------------------------------------------|------------------------------|-----------------------------------------|
+|                 | high-pass<br>(kHz)                                  | low-pass (MHz)<br>-60 dB/dec |                                         |
+| 1               | 2.5                                                 | 10                           | 0.30                                    |
+|                 | 500                                                 | 10                           | 0.10                                    |
+| 2               | 5                                                   | 20                           | 0.30                                    |
+|                 | 1000                                                | 20                           | 0.10                                    |
+| 3               | 20                                                  | 80                           | 0.30                                    |
+|                 | 4000                                                | 80                           | 0.10                                    |
+
+NOTE 1 – The high-pass and low-pass measurement filter transfer functions are defined in clause 5 of [ITU-T G.825].  
+NOTE 2 – The measurement time and pass/fail criteria are defined in clause 5 of [ITU-T G.825].  
+NOTE 3 – This table comes from [ITU-T G.783]
+
+# Annex B
+
+## Auxiliary management and control channel
+
+(This annex forms an integral part of this Recommendation.)
+
+This annex describes the physical layer of the auxiliary management and control channel (AMCC) function for NG-PON2, which is mandatory to be implemented in the PtP WDM PON overlay channels. The AMCC must be compatible with the TWDM PON and PtP WDM PON specifications in this Recommendation's main body and Annex A.
+
+## B.1 Introduction
+
+In the PtP WDM PON part of NG-PON2, a so-called auxiliary management and control channel is needed in order to convey wavelength assignment and allocation information and OAM data. The AMCC is added to each individual wavelength in both, downstream and upstream direction. Two different physical-layer implementations of the AMCC exist. These determine the way the AMCC content is transported over the physical channel. The content of the AMCC is independent of the way it is transmitted and is described in clause 6 and Annex G of [ITU-T G.989.3].
+
+For the case that the PtP WDM PON system has to transparently transport a payload bitstream, without terminating any part of its frame structure, the AMCC has to be added to the payload at the same wavelength with only minor interference of the AMCC and the payload data. This case is called *transparent AMCC*. The framed AMCC data is added to the payload with low-modulation-index baseband over-modulation (i.e., a low-frequency amplitude modulation which is superimposed to the (amplitude) modulation of the payload bitstream). Alternatively, electrical-addition of amplitude-modulated signal with low-frequency carrier to the payload, called RF-pilot-tone-style, can be employed for accommodating the framed AMCC data. The detection of the baseband-overmodulation-based AMCC can (for example) be done by low-pass filtering of the detected payload signal and passing the amplified resulting signal into a simple threshold detector. The RF-pilot-tone-style AMCC can (for example) be detected by simple digital signal processing offering the functions of band-pass filtering, down-conversion and symbol decision.
+
+In the case that the PtP WDN PON system converts the payload data encoding from one to another, the AMCC data can be transmitted by means of code transformation. This case is called *transcoding AMCC* and is described in Annex G of [ITU-T G.989.3].
+
+## B.2 Transparent AMCC
+
+### B.2.1 Baseband overmodulation
+
+The physical transport layer for the overmodulation-based AMCC is realized as a low-bitrate, low-modulation-index baseband amplitude over-modulation over the optical PtP payload signal. The modulation index  $M$  is calculated (in percent) as  $M = 100 * \frac{P_{\max} - P_{\min}}{P_{\text{average}}}$  with  $P_{\max}$ ,  $P_{\min}$  and  $P_{\text{average}}$
+
+referring to the maximum, minimum and average power values of the envelope of the over-modulated PtP signal. The optical interface parameters for the AMCC are given in Table B.1.
+
+**Table B.1 – Optical interface parameters of transparent AMCC**
+
+| Item              | Unit | Value       |
+|-------------------|------|-------------|
+| Nominal line rate | kb/s | 115         |
+| Modulation index  | %    | 10          |
+| Pulse shape       | –    | Rectangular |
+
+### **B.2.2 RF-pilot-tone**
+
+The physical transport layer for the RF-pilot-tone-based AMCC is realized as a low-bitrate, low-carrier-frequency, low-modulation-index amplitude modulation signal which is added to the PtP payload signal in the electrical domain. The modulation index  $M$  is defined (in percent) as
+
+$$M = 100 * \frac{V_{pp,AMCC}}{V_{pp,payload}}, \text{ with } V_{pp,AMCC} \text{ and } V_{pp,payload} \text{ referring to the peak to peak voltage values of the}$$
+
+AMCC and the PtP signal in the electrical domain. The interface parameters for the RF-pilot-tone-style AMCC are given in Table B.2.
+
+**Table B.2 – Electrical interface parameters of transparent AMCC**
+
+| Item              | Unit | Value |
+|-------------------|------|-------|
+| Nominal line rate | kb/s | 128   |
+| Modulation index  | %    | 10    |
+| carrier-frequency | kHz  | 500   |
+
+# Annex C
+
+## Low loss (LL) PtP WDM PON PMD layer requirements
+
+(This annex forms an integral part of this Recommendation.)
+
+This annex describes a low loss PtP WDM PON system that caters to the wavelength routed (WR) use cases within NG-PON2.
+
+The characteristic of a PtP WDM PON is that each ONU is served by one pair of upstream and downstream wavelengths dedicated to this ONU. On the OLT side, downstream wavelengths are multiplexed onto a shared, bidirectional fibre connecting the wavelength multiplexer (WM) to a branching node. Figure C.1 shows a logical view of a PtP WDM PON based on wavelength routed ODN, which is one of the optional use cases of NG-PON2. The wavelength-routed PtP WDM PON (WR PtP WDM PON) has the  $\lambda$  selection function as part of the branching node. The ONU's wavelength is determined by its physical connectivity to the ODN, for example by a port on an AWG.
+
+Examples of PtP WDM PON clients include GbE, 10GbE and CPRI. The OLT channel pair may also exist in multiple instances, particularly to support different client types.
+
+At a branching node (BN), the ODN branches out to drop fibres, one for each ONU. The BN may include any combination of power splitters, bandpass or bandstop filters, or wavelength filters (e.g., AWGs). In the specific case of wavelength-routed PtP WDM PON, a wavelength selection function is required in the branching node, one wavelength per direction for each drop fibre.
+
+![Figure C.1: Logical architecture of wavelength routed PtP WDM PON. The diagram shows multiple PtP WDM OLT CTs (CT1, CT2, ..., CTn) connected to a Wavelength Multiplexer (WM) via S/R-CP interfaces. The WM is connected to an Optical Distribution Network (ODN) via an S/R-CG interface. The ODN connects to a Branching node via an R/S interface. The Branching node has a 'λ selection function' and is connected to multiple PtP WDM ONUs (ONU1, ONU2, ..., ONUn) via drop fibres labeled λ1, λ2, ..., λn. Vertical dashed lines separate the OLT side, the S/R-CG interface, the ODN, and the R/S interface.](ad555483986d7170a46ce72d164b5bc8_img.jpg)
+
+Figure C.1: Logical architecture of wavelength routed PtP WDM PON. The diagram shows multiple PtP WDM OLT CTs (CT1, CT2, ..., CTn) connected to a Wavelength Multiplexer (WM) via S/R-CP interfaces. The WM is connected to an Optical Distribution Network (ODN) via an S/R-CG interface. The ODN connects to a Branching node via an R/S interface. The Branching node has a 'λ selection function' and is connected to multiple PtP WDM ONUs (ONU1, ONU2, ..., ONUn) via drop fibres labeled λ1, λ2, ..., λn. Vertical dashed lines separate the OLT side, the S/R-CG interface, the ODN, and the R/S interface.
+
+G.989.2(14)-Amd.1(16)\_FC.1
+
+**Figure C.1 – Logical architecture of wavelength routed PtP WDM PON**  
+(one use case in the NG-PON2 system)
+
+## C.1 PMD layer requirements
+
+All parameters are specified as follows, and are in accordance with Table C.3 to Table C.8.
+
+All parameter values specified are worst-case values, to be met over the range of operating conditions such as temperature and humidity, and include ageing effects, as specified in clause 9.9 of [ITU-T G.989.1]. The parameters are specified relative to a bit error ratio (BER) not worse than the values specified in Table C.3 to Table C.8.
+
+#### C.1.1 ODN optical path loss classes
+
+ODN optical path loss classes (ODN classes) are specified in Table C.1.
+
+The optical path loss for each class is specified between S/R-CG at the OLT and R/S at the ONU side in each direction. OLT side WM is not included in ODN, but it will impact OLT launch power and sensitivity.
+
+**Table C.1 – ODN optical path loss classes (ODN classes)**
+
+|                                        | Class L1 | Class L2 |
+|----------------------------------------|----------|----------|
+| Minimum optical path loss              | 8 dB     | 16 dB    |
+| Maximum optical path loss              | 17 dB    | 25 dB    |
+| Maximum differential optical path loss | 9 dB     |          |
+
+#### C.1.2 Fibre distance classes
+
+Fibre distance classes are specified in Table 6-2.
+
+#### C.1.3 Line rate
+
+This clause specifies the line rates required to support various LL PtP WDM PON clients.
+
+Parameters to be defined are categorized by downstream and upstream, and the nominal line rates as shown in Line rate class.
+
+The LL PtP WDM PON supports three classes of line rates. Each line rate applies for a symmetric service protocol, i.e., the downstream and the upstream line rates are identical for the respective service protocol. The downstream and upstream PMD parameters are specified in Table C.3 to Table C.8.
+
+**Table C.2 – Relation between LL PtP WDM PON line rate classes and optical parameter tables**
+
+| Line rate class | Nominal line rate [Gbit/s] – Symmetric DS and US                    | Supported UNI                                                                                           | Reference table downstream/upstream |
+|-----------------|---------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------|-------------------------------------|
+| 1               | 1.24416,<br>1.25,<br>1.2288                                         | STM-8<br>1G Ethernet<br>CPRI option 2                                                                   | Table C.3/Table C.4                 |
+| 2               | 2.48832,<br>2.4576,<br>2.666                                        | OC-48, STM-16<br>CPRI option 3<br>OTU1                                                                  | Table C.5/Table C.6                 |
+| 3               | 6.144<br>9.95328,<br>9.8304,<br>10.709, 11.09<br>10.3125<br>10.1376 | CPRI option 6, OBSAI<br>OC-192, STM-64<br>CPRI option 7<br>OTU2, OTU2e<br>10G Ethernet<br>CPRI option 8 | Table C.7/Table C.8                 |
+
+#### C.1.4 FEC code selection
+
+The choice of FEC depends on the service protocol.
+
+Both FEC ON and FEC OFF (or no FEC) can be supported.
+
+#### C.1.5 Line code
+
+Line coding for PtP WDM PON is determined by the specific application.
+
+#### C.1.6 Operating wavelength
+
+LL PtP WDM PON spectrum is specified according to Table 9-1, subject to spectrum otherwise assigned or in use.
+
+Two wavelength bands for LL PtP WDM PON are specified:
+
+- 1) Shared spectrum band: 1603-1625 nm;
+- 2) Expanded spectrum band: 1524-1625 nm.
+
+Spectral flexibility is required to allow re-use of unoccupied bands in other coexistence scenarios where legacy bands and TWDM PON bands are available.
+
+Upstream and downstream can be in separate spectral regions or share the same spectral band.
+
+#### C.1.7 PMD parameters
+
+The assumptions for the physical media dependent (PMD) parameters for the low loss PtP WDM PON in the following tables are different than those used for Annex A. This is due to the fact that one aspect of the low loss approach is to allow wavelength routed ODNs which facilitate a larger number of PtP channels. This affects the calculations of OOB, OOC and inter-channel cross talk, as is noted in the particular tables.
+
+##### C.1.7.1 Optical interface parameters for line rate class 1
+
+The following optical interface parameter tables are applicable for up to 40 km fibre length.
+
+**Table C.3 – Optical interface parameters for line rate class 1  
+(from 1.2288 Gbit/s to 1.25 Gbit/s) downstream direction**
+
+| Item                                                                                 | Unit   | Value                                                                        |    |
+|--------------------------------------------------------------------------------------|--------|------------------------------------------------------------------------------|----|
+| <b>OLT transmitter (optical interface S)</b>                                         |        |                                                                              |    |
+| Nominal line rate                                                                    | Gbit/s | 1.2288 to 1.25                                                               |    |
+| Operating wavelength band                                                            | nm     | 1603-1625 (shared spectrum)<br>1524-1625 (expanded spectrum)                 |    |
+| Minimum operating channel spacing                                                    | GHz    | 50                                                                           |    |
+| Maximum operating channel spacing                                                    | GHz    | 200                                                                          |    |
+| Maximum spectral excursion                                                           | GHz    | +/-12.5 for 50 GHz CS<br>+/-20 for 100 GHz CS<br>+/-25 for 200 GHz CS        |    |
+| Line code                                                                            | –      | Determined by application<br>(scrambled NRZ assumed<br>for parameter values) |    |
+| Mask of the transmitter eye diagram                                                  | –      | See clause C.1.8.2                                                           |    |
+| Maximum reflectance of equipment<br>at S/R-CG, measured at transmitter<br>wavelength | dB     | NA                                                                           |    |
+| Minimum ORL of ODN at S/R-CG                                                         | dB     | 32                                                                           |    |
+| ODN Class                                                                            |        | L1                                                                           | L2 |
+| Mean channel launch power minimum<br>(at S/R-CG) without FEC                         | dBm    | -5                                                                           | +3 |
+| Mean channel launch power minimum<br>(at S/R-CG) with FEC                            | dBm    | -8                                                                           | 0  |
+| Mean channel launch power maximum                                                    | dBm    | -1                                                                           | +7 |
+
+**Table C.3 – Optical interface parameters for line rate class 1  
+(from 1.2288 Gbit/s to 1.25 Gbit/s) downstream direction**
+
+| Item                                                                        | Unit            | Value                                                                                                                                                                                                                                                 |     |
+|-----------------------------------------------------------------------------|-----------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----|
+| (at S/R-CG) without FEC                                                     |                 |                                                                                                                                                                                                                                                       |     |
+| Mean channel launch power maximum<br>(at S/R-CG) with FEC                   | dBm             | –4                                                                                                                                                                                                                                                    | +4  |
+| Maximum downstream WNE-PSD                                                  | dBm<br>(15 GHz) | FFS                                                                                                                                                                                                                                                   |     |
+| Minimum extinction ratio (at S/R-CG)<br>(Note 1)                            | dB              | 8.2                                                                                                                                                                                                                                                   |     |
+| Tolerance to reflected optical power                                        | dB              | –15                                                                                                                                                                                                                                                   |     |
+| Dispersion range (Note 2)                                                   | ps/nm           | $0 \text{ to } \frac{0.092 \times \lambda}{4} \left[ 1 - \left( \frac{1300}{\lambda} \right)^2 \right] \times 20$ (DD20),<br>$0 \text{ to } \frac{0.092 \times \lambda}{4} \left[ 1 - \left( \frac{1300}{\lambda} \right)^2 \right] \times 40$ (DD40) |     |
+| Minimum side mode suppression ratio<br>(Note 3)                             | dB              | 30                                                                                                                                                                                                                                                    |     |
+| Maximum downstream per channel out-of-band optical PSD (Note 6)             | dBm<br>(15 GHz) | –49.2                                                                                                                                                                                                                                                 |     |
+| Maximum downstream per channel out-of-channel optical PSD (Note 7)          | dBm<br>(15 GHz) | –61.2                                                                                                                                                                                                                                                 |     |
+| Jitter generation                                                           | –               | See clause C.1.8.3                                                                                                                                                                                                                                    |     |
+| ONU receiver (optical interface R)                                          |                 |                                                                                                                                                                                                                                                       |     |
+| Maximum OPP (Note 4)<br>– with Raman effects                                | dB              | 2.0 (without FEC)                                                                                                                                                                                                                                     |     |
+|                                                                             |                 | 1.0 (with FEC ON)                                                                                                                                                                                                                                     |     |
+| Maximum reflectance of equipment at R/S,<br>measured at receiver wavelength | dB              | –20                                                                                                                                                                                                                                                   |     |
+| Rx wavelength channel tuning time                                           |                 | See Table 9-2                                                                                                                                                                                                                                         |     |
+| Maximum tuning granularity                                                  | GHz             | CS/20                                                                                                                                                                                                                                                 |     |
+| ODN Class                                                                   |                 | L1                                                                                                                                                                                                                                                    | L2  |
+| Sensitivity (at R/S) @ BER=10 <sup>–12</sup>                                | dBm             | –24                                                                                                                                                                                                                                                   | –24 |
+| Sensitivity (at R/S) @ BER=10 <sup>–4</sup> (Note 5)                        | dBm             | –26                                                                                                                                                                                                                                                   | –26 |
+| Overload (at R/S) @ BER=10 <sup>–12</sup>                                   | dBm             | –2                                                                                                                                                                                                                                                    | –2  |
+| Overload (at R/S) @ BER=10 <sup>–4</sup> (Note 5)                           | dBm             | –5                                                                                                                                                                                                                                                    | –5  |
+| In-band crosstalk tolerance                                                 | dB<br>(15 GHz)  | 37.2                                                                                                                                                                                                                                                  |     |
+| Consecutive identical digit immunity                                        | bit             | 72                                                                                                                                                                                                                                                    |     |
+| Jitter tolerance                                                            | –               | See clause C.1.8.3                                                                                                                                                                                                                                    |     |
+
+**Table C.3 – Optical interface parameters for line rate class 1  
+(from 1.2288 Gbit/s to 1.25 Gbit/s) downstream direction**
+
+| Item                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             | Unit | Value |
+|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------|-------|
+| NOTE 1 – A lower extinction ratio must be compensated by a larger transmitter launch power within the limits of the mean launch power MAX value.<br>NOTE 2 – This formula (see clause 6.10 of [ITU-T G.652]) is used instead of the worst case value due to the large variation of dispersion within the LL PtP WDM PON wavelength band. This allows implementers to build devices only to the desired dispersion specification. $\lambda$ is the longest possible wavelength in each channel, in nanometre units, considering the spectral excursion.<br>NOTE 3 – For downstream, SMSR is measured on the laser output, before any filtering. This prevents a significant mode partition noise penalty.<br>NOTE 4 – The specified penalty is valid up to a 40 km optical link distance. If the actual OPP is worse than the specified value, it must be compensated by the transmitter launch power increase up to the limits of the mean launch power maximum. Maximum OPP value assumes the use of the shared spectrum band, OPP related to Raman impacts for the expanded spectrum are determined by application.<br>NOTE 5 – See clause 9.4.1 of [b-ITU-T G.Sup39] for additional details.<br>NOTE 6 – This value is based the following assumptions: OOB impact from PtP WDM PON on TWDM PON can be controlled through appropriate filtering, 0.1 dB penalty, TWDM PON operates with FEC and 16 PtP WDM channels (15 interferers).<br>NOTE 7 – This value is based the following assumptions: OOC in downstream can be controlled through filtering from WM, 0.1 dB penalty, PtP WDM PON operates without FEC, 16 PtP WDM channels (15 interferers).<br>NOTE 8 – The definition of In-band crosstalk tolerance and its implication on receiver sensitivity is defined in clause 3.2.2.10 of [ITU-T G.989]. |      |       |
+
+**Table C.4 – Optical interface parameters of line rate class 1  
+(from 1.2288 Gbit/s to 1.25 Gbit/s) upstream direction**
+
+| Item                                                                        | Unit   | Value                                                                        |
+|-----------------------------------------------------------------------------|--------|------------------------------------------------------------------------------|
+| <b>ONU transmitter (optical interface S)</b>                                |        |                                                                              |
+| Nominal line rate                                                           | Gbit/s | 1.2288 to 1.25                                                               |
+| Operating wavelength band                                                   | nm     | 1603-1625 (shared spectrum)<br>1524-1625 (expanded spectrum)                 |
+| Minimum operating channel spacing                                           | GHz    | 50                                                                           |
+| Maximum operating channel spacing                                           | GHz    | 200                                                                          |
+| Maximum spectral excursion                                                  | GHz    | +/-12.5 for 50 GHz CS<br>+/-20 for 100 GHz CS<br>+/-25 for 200 GHz CS        |
+| Maximum tuning granularity                                                  | GHz    | CS/20                                                                        |
+| Tx wavelength channel tuning time                                           | ms     | See Table 9-2                                                                |
+| Line code                                                                   | –      | Determined by application<br>(scrambled NRZ assumed<br>for parameter values) |
+| Mask of the transmitter eye diagram                                         | –      | See clause C.1.823                                                           |
+| Maximum reflectance of equipment at R/S, measured at transmitter wavelength | dB     | -6                                                                           |
+
+**Table C.4 – Optical interface parameters of line rate class 1  
+(from 1.2288 Gbit/s to 1.25 Gbit/s) upstream direction**
+
+| Item                                                                            | Unit            | Value                                                                                                                                                                                                                                                 |     |
+|---------------------------------------------------------------------------------|-----------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----|
+| Minimum ORL of ODN at R/S                                                       | dB              | 32                                                                                                                                                                                                                                                    |     |
+| ODN Class                                                                       |                 | L1                                                                                                                                                                                                                                                    | L2  |
+| Mean channel launch power minimum<br>(at R/S) without FEC                       | dBm             | -1                                                                                                                                                                                                                                                    | -1  |
+| Mean channel launch power minimum<br>(at R/S) with FEC                          | dBm             | -4                                                                                                                                                                                                                                                    | -4  |
+| Mean channel launch power maximum<br>(at R/S) without FEC                       | dBm             | 4                                                                                                                                                                                                                                                     | 4   |
+| Mean channel launch power minimum<br>(at R/S) with FEC                          | dBm             | 1                                                                                                                                                                                                                                                     | 1   |
+| Minimum extinction ratio (Note 1)                                               | dB              | 8.2                                                                                                                                                                                                                                                   |     |
+| Tolerance to reflected optical power                                            | dB              | -15                                                                                                                                                                                                                                                   |     |
+| Dispersion range (Note 2)                                                       | ps/nm           | $0 \text{ to } \frac{0.092 \times \lambda}{4} \left[ 1 - \left( \frac{1300}{\lambda} \right)^2 \right] \times 20$ (DD20),<br>$0 \text{ to } \frac{0.092 \times \lambda}{4} \left[ 1 - \left( \frac{1300}{\lambda} \right)^2 \right] \times 40$ (DD40) |     |
+| Minimum side mode suppression ratio (Note 3)                                    | dB              | 30                                                                                                                                                                                                                                                    |     |
+| Maximum upstream out-of-band optical PSD<br>(Note 6)                            | dBm<br>(15 GHz) | -55.7                                                                                                                                                                                                                                                 |     |
+| Maximum upstream out-of-channel optical<br>PSD – OOC1 (Note 7)                  | dBm<br>(15 GHz) | -31.7 for 50GHz CS<br>-35.5 for 100 GHz CS<br>-39.4 for 200 GHz CS                                                                                                                                                                                    |     |
+| Maximum upstream out-of-channel optical<br>PSD – OOC2 (Note 7)                  | dBm<br>(15 GHz) | -58.2                                                                                                                                                                                                                                                 |     |
+| Jitter transfer                                                                 | –               | See clause C.1.8.3                                                                                                                                                                                                                                    |     |
+| Jitter generation                                                               | –               | See clause C.1.8.3                                                                                                                                                                                                                                    |     |
+| <b>OLT receiver (optical interface R)</b>                                       |                 |                                                                                                                                                                                                                                                       |     |
+| Maximum OPP (Note 4)                                                            | dB              | 2.0 (without FEC)                                                                                                                                                                                                                                     |     |
+| – with Raman effects                                                            |                 | 1.0 (with FEC on)                                                                                                                                                                                                                                     |     |
+| Maximum reflectance of equipment at S/R-<br>CG, measured at receiver wavelength | dB              | -20                                                                                                                                                                                                                                                   |     |
+| ODN Class                                                                       |                 | L1                                                                                                                                                                                                                                                    | L2  |
+| Sensitivity (at S/R-CG) @ BER=10 <sup>-12</sup>                                 | dBm             | -20                                                                                                                                                                                                                                                   | -28 |
+| Sensitivity (at S/R-CG) @ BER=10 <sup>-4</sup> (Note 5)                         | dBm             | -22                                                                                                                                                                                                                                                   | -30 |
+| Overload (at S/R-CG) @ BER=10 <sup>-12</sup>                                    | dBm             | 3                                                                                                                                                                                                                                                     | -5  |
+| Overload (at S/R-CG) @ BER=10 <sup>-4</sup> (Note 5)                            | dBm             | 1                                                                                                                                                                                                                                                     | -7  |
+
+**Table C.4 – Optical interface parameters of line rate class 1  
+(from 1.2288 Gbit/s to 1.25 Gbit/s) upstream direction**
+
+| Item                                 | Unit           | Value              |
+|--------------------------------------|----------------|--------------------|
+| In-band crosstalk tolerance          | dB<br>(15 GHz) | –37.4              |
+| Consecutive identical digit immunity | bit            | 72                 |
+| Jitter tolerance                     | –              | See clause C.1.8.3 |
+
+NOTE 1 – A lower extinction ratio must be compensated by a larger transmitter launch power within the limits of the mean launch power MAX value.
+
+NOTE 2 – This formula (see clause 6.10 of [ITU-T G.652]) is used instead of the worst case value due to the large variation of dispersion within the LL PtP WDM PON wavelength band. This allows implementers to build devices only to the desired dispersion specification.  $\lambda$  is the longest possible wavelength in each channel, in nanometre units, considering the spectral excursion.
+
+NOTE 3 – For upstream at the ONU, SMSR is measured on the laser output, before any filtering. This prevents a significant mode partition noise penalty.
+
+NOTE 4 – The specified penalty is valid up to a 40 km optical link distance. If the actual OPP is worse than the specified value, it must be compensated by the transmitter launch power increase up to the limits of the mean launch power maximum. Maximum OPP value assumes the use of the shared spectrum band, OPP related to Raman impacts for the Expanded Spectrum are determined by application.
+
+NOTE 5 – See clause 9.4.1 of [b-ITU-T G.Sup39] for additional details.
+
+NOTE 6 – This value is based the following assumptions: remote node is 1:16 splitter limited by the 9 dB differential loss, OOB impact from PtP WDM PON on TWDM PON can be controlled through filtering from WM, 0.1 dB penalty, TWDM PON operates with FEC and 16 PtP WDM channels (15 interferers).
+
+NOTE 7 – This value is based the following assumptions: remote node is 1:16 splitter limited by the 9 dB differential loss, OOC in upstream can be controlled through filtering from WM, 0.1 dB penalty, PtP WDM PON operates without FEC, 16 PtP WDM channels (15 interferers).
+
+NOTE 8 – The definition of In-band crosstalk tolerance and its implication on receiver sensitivity is defined in clause 3.2.2.10 of [ITU-T G.989].
+
+##### C.1.7.2 Optical interface parameters for line rate class 2
+
+The following optical interface parameter tables are applicable for up to 40 km fibre length.
+
+**Table C.5 – Optical interface parameters for line rate class 2  
+(from 2.4576 Gbit/s to 2.666 Gbit/s) downstream direction**
+
+| Item                                                                           | Unit            | Value                                                                                                                                                                                                                                                 |    |
+|--------------------------------------------------------------------------------|-----------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----|
+| <b>OLT transmitter (optical interface S)</b>                                   |                 |                                                                                                                                                                                                                                                       |    |
+| Nominal line rate                                                              | Gbit/s          | 2.4576 to 2.666                                                                                                                                                                                                                                       |    |
+| Operating wavelength band                                                      | nm              | 1603-1625 (shared spectrum)<br>1524-1625 (expanded spectrum)                                                                                                                                                                                          |    |
+| Minimum operating channel spacing                                              | GHz             | 50                                                                                                                                                                                                                                                    |    |
+| Maximum operating channel spacing                                              | GHz             | 200                                                                                                                                                                                                                                                   |    |
+| Maximum spectral excursion                                                     | GHz             | +/-12.5 for 50 GHz CS<br>+/-20 for 100 GHz CS<br>+/-25 for 200 GHz CS                                                                                                                                                                                 |    |
+| Line code                                                                      | –               | Determined by application<br>(scrambled NRZ assumed<br>for parameter values)                                                                                                                                                                          |    |
+| Mask of the transmitter eye diagram                                            | –               | See clause C.1.8.2                                                                                                                                                                                                                                    |    |
+| Maximum reflectance of equipment at S/R-CG, measured at transmitter wavelength | dB              | NA                                                                                                                                                                                                                                                    |    |
+| Minimum ORL of ODN at S/R-CG                                                   | dB              | 32                                                                                                                                                                                                                                                    |    |
+| ODN Class                                                                      |                 | L1                                                                                                                                                                                                                                                    | L2 |
+| Mean channel launch power minimum (at S/R-CG) without FEC                      | dBm             | -5                                                                                                                                                                                                                                                    | +3 |
+| Mean channel launch power minimum (at S/R-CG) with FEC                         | dBm             | -8                                                                                                                                                                                                                                                    | -0 |
+| Mean channel launch power maximum (at S/R-CG) without FEC                      | dBm             | -1                                                                                                                                                                                                                                                    | +5 |
+| Mean channel launch power maximum (at S/R-CG) with FEC                         | dBm             | -4                                                                                                                                                                                                                                                    | +4 |
+| Maximum downstream WNE-PSD                                                     | dBm<br>(15 GHz) | FFS                                                                                                                                                                                                                                                   |    |
+| Minimum extinction ratio (at S/R-CG) (Note 1)                                  | dB              | 8.2                                                                                                                                                                                                                                                   |    |
+| Tolerance to reflected optical power                                           | dB              | -15                                                                                                                                                                                                                                                   |    |
+| Dispersion range (Note 2)                                                      | ps/nm           | $0 \text{ to } \frac{0.092 \times \lambda}{4} \left[ 1 - \left( \frac{1300}{\lambda} \right)^2 \right] \times 20$ (DD20),<br>$0 \text{ to } \frac{0.092 \times \lambda}{4} \left[ 1 - \left( \frac{1300}{\lambda} \right)^2 \right] \times 40$ (DD40) |    |
+| Minimum side mode suppression ratio (Note 3)                                   | dB              | 30                                                                                                                                                                                                                                                    |    |
+| Maximum downstream per channel out-of-band optical PSD (Note 6)                | dBm<br>(15 GHz) | -49.2                                                                                                                                                                                                                                                 |    |
+| Maximum downstream per channel out-of-channel optical PSD (Note 7)             | dBm<br>(15 GHz) | -61.2                                                                                                                                                                                                                                                 |    |
+| Jitter generation                                                              | –               | See clause C.1.8.3                                                                                                                                                                                                                                    |    |
+| <b>ONU receiver (optical interface R)</b>                                      |                 |                                                                                                                                                                                                                                                       |    |
+
+**Table C.5 – Optical interface parameters for line rate class 2  
+(from 2.4576 Gbit/s to 2.666 Gbit/s) downstream direction**
+
+| Item                                                                     | Unit           | Value              |     |
+|--------------------------------------------------------------------------|----------------|--------------------|-----|
+| Maximum OPP (Note 4)<br>– with Raman effects                             | dB             | 2.0 (without FEC)  |     |
+|                                                                          |                | 1.0 (with FEC ON)  |     |
+| Maximum reflectance of equipment at R/S, measured at receiver wavelength | dB             | –20                |     |
+| Rx wavelength channel tuning time                                        |                | See Table 9-2      |     |
+| Maximum tuning granularity                                               | GHz            | CS/20              |     |
+| ODN Class                                                                |                | L1                 | L2  |
+| Sensitivity (at R/S) @ BER= $10^{-12}$                                   | dBm            | –24                | –24 |
+| Sensitivity (at R/S) @ BER= $10^{-4}$ (Note 5)                           | dBm            | –26                | –26 |
+| Overload (at R/S) @ BER= $10^{-12}$                                      | dBm            | –2                 | –2  |
+| Overload (at R/S) @ BER= $10^{-4}$ (Note 5)                              | dBm            | –5                 | –5  |
+| In-band crosstalk tolerance                                              | dB<br>(15 GHz) | –37.2              |     |
+| Consecutive identical digit immunity                                     | bit            | 72                 |     |
+| Jitter tolerance                                                         | –              | See clause C.1.8.3 |     |
+
+NOTE 1 – A lower extinction ratio must be compensated by a larger transmitter launch power within the limits of the mean launch power MAX value.
+
+NOTE 2 – This formula (see clause 6.10 of [ITU-T G.652]) is used instead of the worst case value due to the large variation of dispersion within the LL PtP WDM PON wavelength band. This allows implementers to build devices only to the desired dispersion specification.  $\lambda$  is the longest possible wavelength in each channel, in nanometre units, considering the spectral excursion.
+
+NOTE 3 – For downstream, SMSR is measured on the laser output, before any filtering. This prevents a significant mode partition noise penalty.
+
+NOTE 4 – The specified penalty is valid up to a 40 km optical link distance. If the actual OPP is worse than the specified value, it must be compensated by the transmitter launch power increase up to the limits of the mean launch power maximum. Maximum OPP value assumes the use of the shared spectrum band, OPP related to Raman impacts for the expanded spectrum are determined by application.
+
+NOTE 5 – See clause 9.4.1 of [b-ITU-T G.Sup39] for additional details.
+
+NOTE 6 – This value is based the following assumptions: OOB impact from PtP WDM PON on TWDM PON can be controlled through appropriate filtering, 0.1 dB penalty, TWDM PON operates with FEC and 16 PtP WDM channels (15 interferers).
+
+NOTE 7 – This value is based the following assumptions: OOC in downstream can be controlled through filtering from WM, 0.1 dB penalty, PtP WDM PON operates without FEC, 16 PtP WDM channels (15 interferers).
+
+NOTE 8 – The definition of In-band crosstalk tolerance and its implication on receiver sensitivity is defined in clause 3.2.2.10 of [ITU-T G.989].
+
+**Table C.6 – Optical interface parameters for line rate class 2  
+(from 2.4576 Gbit/s to 2.666 Gbit/s) upstream direction**
+
+| Item                                                                           | Unit            | Value                                                                                                                                                                                                                               |    |
+|--------------------------------------------------------------------------------|-----------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----|
+|                                                                                |                 | <b>ONU transmitter (optical interface S)</b>                                                                                                                                                                                        |    |
+| Nominal line rate                                                              | Gbit/s          | 2.4576 to 2.666                                                                                                                                                                                                                     |    |
+| Operating wavelength band                                                      | nm              | 1603-1625 (shared spectrum)<br>1524-1625 (expanded spectrum)                                                                                                                                                                        |    |
+| Minimum operating channel spacing                                              | GHz             | 50                                                                                                                                                                                                                                  |    |
+| Maximum operating channel spacing                                              | GHz             | 200                                                                                                                                                                                                                                 |    |
+| Maximum tuning granularity                                                     | GHz             | CS/20                                                                                                                                                                                                                               |    |
+| Tx wavelength channel tuning time                                              | ms              | See Table 9-2                                                                                                                                                                                                                       |    |
+| Line code                                                                      | –               | Determined by application<br>(scrambled NRZ assumed<br>for parameter values)                                                                                                                                                        |    |
+| Mask of the transmitter eye diagram                                            | –               | See clause C.1.8.2                                                                                                                                                                                                                  |    |
+| Maximum reflectance of equipment at R/S,<br>measured at transmitter wavelength | dB              | –6                                                                                                                                                                                                                                  |    |
+| Minimum ORL of ODN at R/S                                                      | dB              | 32                                                                                                                                                                                                                                  |    |
+| ODN Class                                                                      |                 | L1                                                                                                                                                                                                                                  | L2 |
+| Mean channel launch power minimum (at R/S)<br>without FEC                      | dBm             | –1                                                                                                                                                                                                                                  | –1 |
+| Mean channel launch power minimum (at R/S)<br>with FEC                         | dBm             | –4                                                                                                                                                                                                                                  | –4 |
+| Mean channel launch power maximum (at<br>R/S) without FEC                      | dBm             | 4                                                                                                                                                                                                                                   | 4  |
+| Mean channel launch power minimum (at R/S)<br>with FEC                         | dBm             | 1                                                                                                                                                                                                                                   | 1  |
+| Minimum extinction ratio (Note 1)                                              | dB              | 8.2                                                                                                                                                                                                                                 |    |
+| Tolerance to reflected optical power                                           | dB              | –15                                                                                                                                                                                                                                 |    |
+| Dispersion range (Note 2)                                                      | ps/nm           | 0 to $\frac{0.092 \times \lambda}{4} \left[ 1 - \left( \frac{1300}{\lambda} \right)^2 \right] \times 20$ (DD20),<br>0 to $\frac{0.092 \times \lambda}{4} \left[ 1 - \left( \frac{1300}{\lambda} \right)^2 \right] \times 40$ (DD40) |    |
+| Minimum side mode suppression ratio (Note 3)                                   | dB              | 30                                                                                                                                                                                                                                  |    |
+| Maximum upstream out-of-band optical PSD<br>(Note 6)                           | dBm<br>(15 GHz) | –55.7                                                                                                                                                                                                                               |    |
+| Maximum upstream out-of-channel optical<br>PSD – OOC1 (Note 7)                 | dBm<br>(15 GHz) | –31.7 for 50 GHz CS<br>–35.5 for 100 GHz CS<br>–39.4 for 200 GHz CS                                                                                                                                                                 |    |
+| Maximum upstream out-of-channel optical<br>PSD – OOC2 (Note 7)                 | dBm<br>(15 GHz) | –58.2                                                                                                                                                                                                                               |    |
+| Jitter transfer                                                                | –               | See clause C.1.8.3                                                                                                                                                                                                                  |    |
+| Jitter generation                                                              | –               | See clause C.1.8.3                                                                                                                                                                                                                  |    |
+| <b>OLT receiver (optical interface R)</b>                                      |                 |                                                                                                                                                                                                                                     |    |
+
+**Table C.6 – Optical interface parameters for line rate class 2  
+(from 2.4576 Gbit/s to 2.666 Gbit/s) upstream direction**
+
+| Item                                                                           | Unit           | Value              |     |
+|--------------------------------------------------------------------------------|----------------|--------------------|-----|
+| Maximum OPP (Note 4)<br>– with Raman effects                                   | dB             | 2.0 (without FEC)  |     |
+|                                                                                |                | 1.0 (with FEC on)  |     |
+| Maximum reflectance of equipment<br>at S/R-CG, measured at receiver wavelength | dB             | –20                |     |
+| ODN Class                                                                      |                | L1                 | L2  |
+| Sensitivity (at S/R-CG) @ BER= $10^{-12}$                                      | dBm            | –20                | –28 |
+| Sensitivity (at S/R-CG) @ BER= $10^{-4}$ (Note 5)                              | dBm            | –22                | –30 |
+| Overload (at S/R-CG) @ BER= $10^{-12}$                                         | dBm            | 3                  | –5  |
+| Overload (at S/R-CG) @ BER= $10^{-4}$ (Note 5)                                 | dBm            | 1                  | –7  |
+| In-band crosstalk tolerance                                                    | dB<br>(15 GHz) | –37.4              |     |
+| Consecutive identical digit immunity                                           | bit            | 72                 |     |
+| Jitter tolerance                                                               | –              | See clause C.1.8.3 |     |
+
+NOTE 1 – A lower extinction ratio must be compensated by a larger transmitter launch power within the limits of the mean launch power MAX value.
+
+NOTE 2 – This formula (see clause 6.10 of [ITU-T G.652]) is used instead of the worst case value due to the large variation of dispersion within the LL PtP WDM PON wavelength band. This allows implementers to build devices only to the desired dispersion specification.  $\lambda$  is the longest possible wavelength in each channel, in nanometre units, considering the spectral excursion.
+
+NOTE 3 – For upstream at the ONU, SMSR is measured on the laser output, before any filtering. This prevents a significant mode partition noise penalty.
+
+NOTE 4 – The specified penalty is valid up to a 40 km optical link distance. If the actual OPP is worse than the specified value, it must be compensated by the transmitter launch power increase up to the limits of the mean launch power maximum. Maximum OPP value assumes the use of the shared spectrum band, OPP related to Raman impacts for the expanded spectrum are determined by application.
+
+NOTE 5 – See clause 9.4.1 of [b-ITU-T G.Sup39] for additional details.
+
+NOTE 6 – This value is based the following assumptions: remote node is 1:16 splitter limited by the 9 dB differential loss, OOB impact from PtP WDM PON on TWDM PON can be controlled through filtering from WM, 0.1 dB penalty, TWDM PON operates with FEC and 16 PtP WDM channels (15 interferers).
+
+NOTE 7 – This value is based the following assumptions: remote node is 1:16 splitter limited by the 9 dB differential loss, OOC in upstream can be controlled through filtering from WM, 0.1 dB penalty, PtP WDM PON operates without FEC, 16 PtP WDM channels (15 interferers).
+
+NOTE 8 – The definition of In-band crosstalk tolerance and its implication on receiver sensitivity is defined in clause 3.2.2.10 of [ITU-T G.989].
+
+##### C.1.7.3 Optical interface parameters for line rate class 3
+
+The following optical interface parameter tables are applicable for up to 40 km fibre length.
+
+**Table C.7 – Optical interface parameters for line rate class 3  
+(from 6.144 Gbit/s to 11.09 Gbit/s) downstream direction**
+
+| Item                                                                           | Unit            | Value                                                                                                                                                                                                                                                                           |    |
+|--------------------------------------------------------------------------------|-----------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----|
+| <b>OLT transmitter (optical interface S)</b>                                   |                 |                                                                                                                                                                                                                                                                                 |    |
+| Nominal line rate                                                              | Gbit/s          | 6.144 to 11.09                                                                                                                                                                                                                                                                  |    |
+| Operating wavelength band                                                      | nm              | 1603-1625 (shared spectrum)<br>1524-1625 (expanded spectrum)                                                                                                                                                                                                                    |    |
+| Minimum operating channel spacing                                              | GHz             | 50                                                                                                                                                                                                                                                                              |    |
+| Maximum operating channel spacing                                              | GHz             | 200                                                                                                                                                                                                                                                                             |    |
+| Maximum spectral excursion                                                     | GHz             | +/-12.5 for 50 GHz CS<br>+/-20 for 100 GHz CS<br>+/-25 for 200 GHz CS                                                                                                                                                                                                           |    |
+| Line code                                                                      | –               | Determined by application<br>(scrambled NRZ assumed for parameter values)                                                                                                                                                                                                       |    |
+| Mask of the transmitter eye diagram                                            | –               | See clause C.1.8.2                                                                                                                                                                                                                                                              |    |
+| Maximum reflectance of equipment at S/R-CG, measured at transmitter wavelength | dB              | NA                                                                                                                                                                                                                                                                              |    |
+| Minimum ORL of ODN at S/R-CG                                                   | dB              | 32                                                                                                                                                                                                                                                                              |    |
+| ODN Class                                                                      |                 | L1                                                                                                                                                                                                                                                                              | L2 |
+| Mean channel launch power minimum (at S/R-CG) without FEC                      | dBm             | -4                                                                                                                                                                                                                                                                              | 4  |
+| Mean channel launch power minimum (at S/R-CG) with FEC                         | dBm             | -6                                                                                                                                                                                                                                                                              | 2  |
+| Mean channel launch power maximum (at S/R-CG) without FEC                      | dBm             | 0                                                                                                                                                                                                                                                                               | 8  |
+| Mean channel launch power maximum (at S/R-CG) with FEC                         | dBm             | -2                                                                                                                                                                                                                                                                              | 6  |
+| Maximum downstream WNE-PSD                                                     | dBm<br>(15 GHz) | FFS                                                                                                                                                                                                                                                                             |    |
+| Minimum extinction ratio (Note 1)                                              | dB              | 6                                                                                                                                                                                                                                                                               |    |
+| Tolerance to reflected optical power                                           | dB              | -15                                                                                                                                                                                                                                                                             |    |
+| Dispersion range (Note 2)                                                      | ps/nm           | $0 \text{ to } \frac{0.092 \times \lambda}{4} \left[ 1 - \left( \frac{1300}{\lambda} \right)^2 \right] \times 20 \quad (\text{DD20}),$<br>$0 \text{ to } \frac{0.092 \times \lambda}{4} \left[ 1 - \left( \frac{1300}{\lambda} \right)^2 \right] \times 40 \quad (\text{DD40})$ |    |
+| Minimum side mode suppression ratio (at S/R-CP) (Note 3)                       | dB              | 30                                                                                                                                                                                                                                                                              |    |
+| Maximum downstream per channel out-of-band optical PSD (Note 6)                | dBm<br>(15 GHz) | -49.2                                                                                                                                                                                                                                                                           |    |
+| Maximum downstream per channel out-of-channel optical PSD (Note 7)             | dBm<br>(15 GHz) | -61.2                                                                                                                                                                                                                                                                           |    |
+| Jitter generation                                                              | –               | See clause C.1.8.3                                                                                                                                                                                                                                                              |    |
+
+**Table C.7 – Optical interface parameters for line rate class 3  
+(from 6.144 Gbit/s to 11.09 Gbit/s) downstream direction**
+
+| Item                                                                     | Unit           | Value              |       |
+|--------------------------------------------------------------------------|----------------|--------------------|-------|
+| <b>ONU receiver (optical interface R)</b>                                |                |                    |       |
+| Maximum OPP (Note 4)<br>– with Raman effects                             | dB             | 2.5 (without FEC)  |       |
+|                                                                          |                | 2.5 (with FEC ON)  |       |
+| Maximum reflectance of equipment at R/S, measured at receiver wavelength | dB             | –20                |       |
+| Rx wavelength channel tuning time                                        |                | See Table 9-2      |       |
+| Maximum tuning granularity                                               | GHz            | CS/20              |       |
+| ODN Class                                                                |                | L1                 | L2    |
+| Sensitivity (at R/S) @ BER= $10^{-12}$                                   | dBm            | –23.5              | –23.5 |
+| Sensitivity (at R/S) @ BER= $10^{-3}$ (Note 5)                           | dBm            | –25.5              | –25.5 |
+| Overload (at R/S) @ BER= $10^{-12}$                                      | dBm            | –1                 | –1    |
+| Overload (at R/S) @ BER= $10^{-3}$ (Note 5)                              | dBm            | –3                 | –3    |
+| In-band crosstalk tolerance                                              | dB<br>(15 GHz) | –38.2              |       |
+| Consecutive identical digit immunity                                     | bit            | 72                 |       |
+| Jitter tolerance                                                         | –              | See clause C.1.8.3 |       |
+
+NOTE 1 – A lower extinction ratio must be compensated by a larger transmitter launch power within the limits of the mean launch power MAX value.
+
+NOTE 2 – This formula (see clause 6.10 of [ITU-T G.652]) is used instead of the worst case value due to the large variation of dispersion within the LL PtP WDM PON wavelength band. This allows implementers to build devices only to the desired dispersion specification.  $\lambda$  is the longest possible wavelength in each channel, in nanometre units, considering the spectral excursion.
+
+NOTE 3 – For downstream, SMSR is measured on the laser output, before any filtering. This prevents a significant mode partition noise penalty.
+
+NOTE 4 – The specified penalty is valid up to a 40 km optical link distance. If the actual OPP is worse than the specified value, it must be compensated by the transmitter launch power increase up to the limits of the mean launch power maximum. Maximum OPP value assumes the use of the shared spectrum band, OPP related to Raman impacts for the expanded spectrum are determined by application.
+
+NOTE 5 – See clause 9.4.1 of [b-ITU-T G.Sup39] for additional details.
+
+NOTE 6 – This value is based the following assumptions: OOB impact from PtP WDM PON on TWDM PON can be controlled through appropriate filtering, 0.1 dB penalty, TWDM PON operates with FEC and 16 PtP WDM channels (15 interferers).
+
+NOTE 7 – This value is based the following assumptions: OOC in downstream can be controlled through filtering from WM, 0.1 dB penalty, PtP WDM PON operates without FEC, 16 PtP WDM channels (15 interferers).
+
+NOTE 8 – The definition of In-band crosstalk tolerance and its implication on receiver sensitivity is defined in clause 3.2.2.10 of [ITU-T G.989].
+
+**Table C.8 – Optical interface parameters of line rate class 3  
+(from 6.144 Gbit/s to 11.09 Gbit/s) upstream direction**
+
+| Item                                                                           | Unit            | Value                                                                                                                                                                                                                                                 |    |
+|--------------------------------------------------------------------------------|-----------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----|
+| <b>ONU transmitter (optical interface S)</b>                                   |                 |                                                                                                                                                                                                                                                       |    |
+| Nominal line rate                                                              | Gbit/s          | 6.144 to 11.09                                                                                                                                                                                                                                        |    |
+| Operating wavelength band                                                      | nm              | 1603-1625 (shared spectrum)<br>1524-1625 (expanded spectrum)                                                                                                                                                                                          |    |
+| Minimum operating channel spacing                                              | GHz             | 50                                                                                                                                                                                                                                                    |    |
+| Maximum operating channel spacing                                              | GHz             | 200                                                                                                                                                                                                                                                   |    |
+| Maximum tuning granularity                                                     | GHz             | CS/20                                                                                                                                                                                                                                                 |    |
+| Tx wavelength channel tuning time                                              | ms              | See Table 9-2                                                                                                                                                                                                                                         |    |
+| Line code                                                                      | –               | Determined by application<br>(scrambled NRZ assumed<br>for parameter values)                                                                                                                                                                          |    |
+| Mask of the transmitter eye diagram                                            | –               | See clause C.1.8.2                                                                                                                                                                                                                                    |    |
+| Maximum reflectance of equipment at R/S,<br>measured at transmitter wavelength | dB              | –6                                                                                                                                                                                                                                                    |    |
+| Minimum ORL of ODN at R/S                                                      | dB              | 32                                                                                                                                                                                                                                                    |    |
+| ODN Class                                                                      |                 | L1                                                                                                                                                                                                                                                    | L2 |
+| Mean channel launch power minimum<br>(at R/S) without FEC                      | dBm             | –1                                                                                                                                                                                                                                                    | –1 |
+| Mean channel launch power minimum<br>(at R/S) with FEC                         | dBm             | –2                                                                                                                                                                                                                                                    | –2 |
+| Mean channel launch power maximum<br>(at R/S) without FEC                      | dBm             | 4                                                                                                                                                                                                                                                     | 4  |
+| Mean channel launch power minimum<br>(at R/S) with FEC                         | dBm             | 3                                                                                                                                                                                                                                                     | 3  |
+| Minimum extinction ratio (Note 1)                                              | dB              | 6                                                                                                                                                                                                                                                     |    |
+| Tolerance to reflected optical power                                           | dB              | –15                                                                                                                                                                                                                                                   |    |
+| Dispersion range (Note 2)                                                      | ps/nm           | $0 \text{ to } \frac{0.092 \times \lambda}{4} \left[ 1 - \left( \frac{1300}{\lambda} \right)^2 \right] \times 20$ (DD20),<br>$0 \text{ to } \frac{0.092 \times \lambda}{4} \left[ 1 - \left( \frac{1300}{\lambda} \right)^2 \right] \times 40$ (DD40) |    |
+| Minimum side mode suppression ratio (Note 3)                                   | dB              | 30                                                                                                                                                                                                                                                    |    |
+| Maximum upstream out-of-band optical PSD<br>(Note 6)                           | dBm<br>(15 GHz) | –55.7                                                                                                                                                                                                                                                 |    |
+| Maximum upstream out-of-channel optical<br>PSD – OOC1 (Note 7)                 | dBm<br>(15 GHz) | –31.7 for 50 GHz CS<br>–35.5 for 100 GHz CS<br>–39.4 for 200 GHz CS                                                                                                                                                                                   |    |
+| Maximum upstream out-of-channel optical<br>PSD – OOC2 (Note 7)                 | dBm<br>(15 GHz) | –58.2                                                                                                                                                                                                                                                 |    |
+| Jitter transfer                                                                | –               | See clause C.1.8.3                                                                                                                                                                                                                                    |    |
+| Jitter generation                                                              | –               | See clause C.1.8.3                                                                                                                                                                                                                                    |    |
+
+**Table C.8 – Optical interface parameters of line rate class 3  
+(from 6.144 Gbit/s to 11.09 Gbit/s) upstream direction**
+
+| Item                                                                           | Unit           | Value              |       |
+|--------------------------------------------------------------------------------|----------------|--------------------|-------|
+| <b>OLT receiver (optical interface R)</b>                                      |                |                    |       |
+| Maximum OPP (Note 4)<br>– with Raman effects                                   | dB             | 2.5 (without FEC)  |       |
+|                                                                                |                | 2.5 (with FEC on)  |       |
+| Maximum reflectance of equipment<br>at S/R-CG, measured at receiver wavelength | dB             | –20                |       |
+| ODN Class                                                                      |                | L1                 | L2    |
+| Sensitivity (at S/R-CG) @ BER= $10^{-12}$                                      | dBm            | –20.5              | –28.5 |
+| Sensitivity (at S/R-CG) @ BER= $10^{-3}$ (Note 5)                              | dBm            | –21.5              | –29.5 |
+| Overload (at S/R-CG) @ BER= $10^{-12}$                                         | dBm            | 3                  | –5    |
+| Overload (at S/R-CG) @ BER= $10^{-3}$ (Note 5)                                 | dBm            | 2                  | –6    |
+| In-band crosstalk tolerance                                                    | dB<br>(15 GHz) | –37.4              |       |
+| Consecutive identical digit immunity                                           | bit            | 72                 |       |
+| Jitter tolerance                                                               | –              | See clause C.1.8.3 |       |
+
+NOTE 1 – A lower extinction ratio must be compensated by a larger transmitter launch power within the limits of the mean launch power MAX value.
+
+NOTE 2 – This formula (see clause 6.10 of [ITU-T G.652]) is used instead of the worst case value due to the large variation of dispersion within the LL PtP WDM PON wavelength band. This allows implementers to build devices only to the desired dispersion specification.  $\lambda$  is the longest possible wavelength in each channel, in nanometre units, considering the spectral excursion.
+
+NOTE 3 – For upstream at the ONU, SMSR is measured on the laser output, before any filtering. This prevents a significant mode partition noise penalty.
+
+NOTE 4 – The specified penalty is valid up to a 40 km optical link distance. If the actual OPP is worse than the specified value, it must be compensated by the transmitter launch power increase up to the limits of the mean launch power maximum. Maximum OPP value assumes the use of the shared spectrum band, OPP related to Raman impacts for the expanded spectrum are determined by application.
+
+NOTE 5 – See clause 9.4.1 of [b-ITU-T G.Sup39] for additional details.
+
+NOTE 6 – This value is based the following assumptions: remote node is 1:16 splitter limited by the 9 dB differential loss, OOB impact from PtP WDM PON on TWDM PON can be controlled through filtering from WM, 0.1 dB penalty, TWDM PON operates with FEC and 16 PtP WDM channels (15 interferers).
+
+NOTE 7 – This value is based the following assumptions: remote node is 1:16 splitter limited by the 9 dB differential loss, OOC in upstream can be controlled through filtering from WM, 0.1 dB penalty, PtP WDM PON operates without FEC, 16 PtP WDM channels (15 interferers).
+
+NOTE 8 – The definition of In-band crosstalk tolerance and its implication on receiver sensitivity is defined in clause 3.2.2.10 of [ITU-T G.989].
+
+#### C.1.8 Transmitter at reference point S
+
+This clause is in accordance with clause 11.1.5, except where indicated otherwise.
+
+##### C.1.8.1 Nominal central frequency
+
+The nominal single channel frequencies on which the digital coded information of the particular optical wavelength channels are modulated.
+
+The central frequencies depend on the specific WM used.
+
+##### C.1.8.2 Mask of transmitter eye diagram
+
+The parameters specifying the mask of the eye diagram, illustrated in Figure C.2, for both the OLT and ONU transmitters are shown in Table C.9.
+
+![Figure C.2: Mask of the eye diagram for OLT and ONU transmitter. The diagram shows an eye diagram with a rectangular mask overlaid. The vertical axis represents voltage levels from -y4 to 1+y3, with markers at 0, 0.5, 1, y1, y2, and y3. The horizontal axis represents time from 0 to 1. The mask is defined by x2 and x3 on the horizontal axis and y1, y2, y3, and y4 on the vertical axis. The mean level of the center of logical '1' is indicated at level 1, and the mean level of the center of logical '0' is indicated at level 0. The source code G.989.2(14)-Amd.1(16)_FC.2 is shown at the bottom right.](33d66c42e2c44378aaab641502989484_img.jpg)
+
+Figure C.2: Mask of the eye diagram for OLT and ONU transmitter. The diagram shows an eye diagram with a rectangular mask overlaid. The vertical axis represents voltage levels from -y4 to 1+y3, with markers at 0, 0.5, 1, y1, y2, and y3. The horizontal axis represents time from 0 to 1. The mask is defined by x2 and x3 on the horizontal axis and y1, y2, y3, and y4 on the vertical axis. The mean level of the center of logical '1' is indicated at level 1, and the mean level of the center of logical '0' is indicated at level 0. The source code G.989.2(14)-Amd.1(16)\_FC.2 is shown at the bottom right.
+
+Figure C.2 – Mask of the eye diagram for OLT and ONU transmitter
+
+Table C.9 – Mask of the eye diagram for OLT and ONU transmitters – Numeric values
+
+| Line rate class | 1.2288 to 1.25 Gbit/s | 2.4576 to 2.666 Gbit/s | 6.144 to 11.09 Gbit/s |
+|-----------------|-----------------------|------------------------|-----------------------|
+| x3-x2 (Note 1)  | 0.2                   | 0.2                    | 0.2                   |
+| y1, y3, y4      | 0.25                  | 0.25                   | 0.25                  |
+| y2              | 0.75                  | 0.75                   | 0.75                  |
+
+NOTE 1 – x2 and x3 of the rectangular eye mask need not be equidistant with respect to the vertical axes at 0 UI and 1 UI.
+
+NOTE 2 – The values for the classes 2 (~2.5Gbit/s) and 3 (~ 10 Gbit/s) are taken from clause 7.2.2.14 of [ITU-T G.959.1].
+
+NOTE 3 – The values for the class 1 (~1.25 Gbit/s) are derived from clause 7.2.2.14 of [ITU-T G.959.1].
+
+##### C.1.8.3 Jitter performance
+
+Jitter performance of PtP WDM PON is in accordance with the definitions in clause 11.1.5.4 with the following modifications. Descriptions in clause 11.1.5.4 are repeated for completeness.
+
+Jitter transfer for ONU:
+
+![Figure C.3: Jitter transfer for ONU. A graph showing Jitter gain (P) versus Frequency. The gain is constant at P from f_L to f_C, then decreases with a slope of -20 dB/dec until f_H. The graph is labeled G.989.2(14)-Amd.1(16)_FC.3.](a4cb63f5debf833e6069e99143a2b624_img.jpg)
+
+Figure C.3: Jitter transfer for ONU. A graph showing Jitter gain (P) versus Frequency. The gain is constant at P from f\_L to f\_C, then decreases with a slope of -20 dB/dec until f\_H. The graph is labeled G.989.2(14)-Amd.1(16)\_FC.3.
+
+**Figure C.3 – Jitter transfer for ONU**
+
+**Table C.10 – Jitter transfer parameters for ONU**
+
+| Line rate class                                                          | $f_L$ (kHz) | $f_C$ (kHz) | $f_H$ (kHz) | P (dB) |
+|--------------------------------------------------------------------------|-------------|-------------|-------------|--------|
+| 1.2288 to 1.25 Gbit/s                                                    | 10          | 1000        | 10 000      | 0.1    |
+| 2.4576 to 2.666 Gbit/s                                                   | 20          | 2000        | 20 000      | 0.1    |
+| 6.144 to 11.09 Gbit/s                                                    | 10          | 1000        | 80 000      | 0.1    |
+| NOTE – These values are taken or derived from clause 15 of [ITU-T G.783] |             |             |             |        |
+
+High-band portion of sinusoidal jitter mask for jitter transfer:
+
+![Figure C.4: High-band portion of sinusoidal jitter mask for jitter transfer. A graph showing Input jitter amplitude (A3, A4) versus Frequency. The amplitude is constant at A3 until frequency f2, then decreases with a slope of -20 dB/dec until f3, where it becomes constant at A4. The graph is labeled G.989.2(14)-Amd.1(16)_FC.4.](9ded0df3aa355d1a7fdb8598fdf54bff_img.jpg)
+
+Figure C.4: High-band portion of sinusoidal jitter mask for jitter transfer. A graph showing Input jitter amplitude (A3, A4) versus Frequency. The amplitude is constant at A3 until frequency f2, then decreases with a slope of -20 dB/dec until f3, where it becomes constant at A4. The graph is labeled G.989.2(14)-Amd.1(16)\_FC.4.
+
+**Figure C.4 – High-band portion of sinusoidal jitter mask for jitter transfer**
+
+**Table C.11 – High-band portions of sinusoidal jitter mask parameters**
+
+| Line rate class                                                           | $A_3$ (UI) | $A_4$ (UI) | $f_2$ (kHz) | $f_3$ (kHz) |
+|---------------------------------------------------------------------------|------------|------------|-------------|-------------|
+| 1.2288 to 1.25 Gbit/s                                                     | 1.5        | 0.15       | 50          | 500         |
+| 2.4576 to 2.666 Gbit/s                                                    | 1.5        | 0.15       | 100         | 1000        |
+| 6.144 to 11.09 Gbit/s                                                     | 1.5        | 0.15       | 400         | 4000        |
+| NOTE – These values are taken or derived from clause 15 of [ITU-T G.783]. |            |            |             |             |
+
+Jitter tolerance mask:
+
+![Figure C.5 – Jitter tolerance mask. A graph showing Input jitter amplitude on the y-axis and Frequency on the x-axis. The mask is defined by two horizontal levels, A1 and A2, and a sloped region between them. The horizontal part at A2 extends from 0 to f0. The sloped part has a slope of -20 dB/dec and connects A2 at f0 to A1 at ft. The horizontal part at A1 extends from ft to infinity. The area under the mask is shaded gray. A small note at the bottom right of the graph reads 'G.989.2(14)-Amd.1(16)_FC.5'.](d7ce27646f87a7bec81474bed33145ef_img.jpg)
+
+Figure C.5 – Jitter tolerance mask. A graph showing Input jitter amplitude on the y-axis and Frequency on the x-axis. The mask is defined by two horizontal levels, A1 and A2, and a sloped region between them. The horizontal part at A2 extends from 0 to f0. The sloped part has a slope of -20 dB/dec and connects A2 at f0 to A1 at ft. The horizontal part at A1 extends from ft to infinity. The area under the mask is shaded gray. A small note at the bottom right of the graph reads 'G.989.2(14)-Amd.1(16)\_FC.5'.
+
+Figure C.5 – Jitter tolerance mask
+
+Table C.12 – Jitter tolerance mask parameters
+
+| Line rate class                                                                                   | $f_t$ [kHz] | $f_0$ [kHz] | A1 [UIp-p] | A2 [UIp-p] |
+|---------------------------------------------------------------------------------------------------|-------------|-------------|------------|------------|
+| 1.2288 to 1.25 Gbit/s                                                                             | 500         | 50          | 0.075      | 0.75       |
+| 2.4576 to 2.666 Gbit/s                                                                            | 1000        | 100         | 0.075      | 0.75       |
+| 6.144 to 11.09 Gbit/s                                                                             | 4000        | 400         | 0.075      | 0.75       |
+| NOTE – These values are scaled to 10 Gbit/s from the values in clause 8.2.8.9 of [ITU-T G.984.2]. |             |             |            |            |
+
+# Annex D
+
+## ONU power levelling
+
+(This annex forms an integral part of this Recommendation.)
+
+## D.1 Interaction between NG-PON2 PMD layer and TC layer
+
+Power levelling is defined to allow the ONU's mean launch power level to be attenuated in order to meet certain criteria. This levelling can be initiated by the OLT, or managed completely by the ONU. The ONU can activate at its highest attenuation level, gradually adjusting its attenuation level to achieve steps of higher mean launch power, until the ONU initially ranges on the PON. In this annex, the focus is on ONU autonomous optical power levelling, providing an example of how it can be used.
+
+## D.2 Power levelling (PL) mechanism at ONU transmitter
+
+The introduction of multi-wavelengths in PON, in combination with the large differential optical path loss of the ODN, results in several difficult to meet optical parameters, namely:
+
+- 1) Out of band PSD
+- 2) Out of channel PSD
+- 3) Wavelength multiplexer isolation
+- 4) OLT receiver overload
+
+While a number of potential mechanisms exist to meet the various parameters, the use of PL is able to mitigate all of these effects with a single mechanism. However, to obtain the latter two benefits of WM isolation and OLT receiver overload relaxation all ONUs on the ODN must employ the same PL mechanism. Described in this Annex are the details of the mechanism which shall be used if PL is applied.
+
+PL can be realized in at least two different ways. First, the laser current can be adjusted to achieve a modest reduction in optical out, but only in the main mode of the laser (i.e., broadband side mode and amplified spontaneous emission (ASE) power are not impacted). As a result, this mechanism is only useful in addressing WM isolation and OLT Rx overload. A second approach is the use of a variable optic attenuator (VOA) function that attenuates all of the light from the ONU transmitter which then addresses all four of the optical parameters listed above. This annex focuses on using the VOA method to control PL.
+
+Further, the PL mechanism can also be realized via autonomous and/or directed command mechanisms.
+
+## D.3 ONU autonomous power levelling
+
+It is possible for the ONU to autonomously control its output power based on the received signal strength indication (RSSI) value, which is an approximation of the actual received downstream power from the OLT via the ODN. Therefore the RSSI is an approximate indication of the ODN loss. Note that the RSSI includes the variability of the OLT laser power which is 4 dB. However autonomous PL can still be effective in reducing the impact of the ODN dynamic range as long as it does not have to eliminate the entire dynamic range but rather reduce it. The following mechanism for autonomous PL will take advantage of the ITU-T G.989.2 PMD requirements that define the highest allowed optical power expected at the ONU. When the highest optical power is received the ODN should be at minimum allowed attenuation (for a given ODN class) and the OLT Tx power should be at the maximum allowed transmit power (for a given ODN class). If the downstream is at the minimum allowed attenuation then the upstream must also be at the minimum allowed attenuation, except for the difference in the optical attenuation for the upstream vs. downstream
+
+wavelengths. The differential attenuation due to wavelength difference is well under 1 dB even for a 40 km ODN and is not considered in this annex.
+
+The following example will examine the relationship between the downstream RSSI and the appropriate PL setting as well as the magnitude of mitigation of the ODN dynamic range that may be obtained autonomously by the ONU using PL.
+
+Example:
+
+Tables 11-5 and 11-7 for 10G downstream and upstream type A links contain the following relevant parameters:
+
+- OOC2 PSD = -45.7 dBm/15 GHz;
+- ONU Rx Sensitivity = -28 dBm;
+- ONU Rx Overload = -7 dBm;
+- ONU Tx Maximum Power = +9 dBm.
+
+Additionally, Appendix II and Table 6-1, contain, respectively, the following parameters:
+
+- ONU RSSI accuracy = +/-3 dB;
+- ODN maximum differential optical path loss = 15 dB.
+
+If the ONU RSSI reading were considered absolutely accurate and the reading was -7 dBm this would indicate that the ODN is at the minimum loss with the OLT Tx at maximum power. This would allow the transmitter power to be reduced by 15 dB using PL. However due to the +/-3 dB accuracy error of the RSSI, the allowed PL is reduced by 3 dB to only 12 dB. It is assumed in this analysis that the inaccuracy of the PL attenuation is negligible. As the downstream RSSI decreases, the PL must eventually be reduced until the PL = 0 and the laser reaches full power to ensure minimum upstream optical power is obtained over the entire ODN attenuation range.
+
+While it is possible to determine the approximate laser power using optical line supervision parameters at the ONU, the tolerance of that reading is no better than the RSSI. So the only useful information available to the ONU is the downstream RSSI and it must be assumed that the ODN loss is increasing rather than the OLT Tx power is decreasing as RSSI falls.
+
+To avoid falling below the OLT minimum receive power level, the ONU must begin to reduce the PL from 12 dB when the RSSI falls below -7 dBm.
+
+Assuming the minimum step size is 3 dB the following rules would apply (other steps, for example 1 dB, are also possible):
+
+- 1) If the ONU RSSI is greater than or equal to -7 dBm, then PL of 12 dB is applied.
+- 2) If the ONU RSSI is less than -7 and greater than or equal to -10 dBm, then PL of 9 dB is applied.
+- 3) If the ONU RSSI is less than -10 and greater than or equal to -13 dBm, then PL of 6 dB is applied.
+- 4) If the ONU RSSI is less than -13 and greater than or equal to -16 dBm, then PL of 3 dB is applied.
+- 5) If the ONU RSSI is less than -16 then PL of 0 dB is applied.
+
+The PL procedure reduces the apparent differential optical path loss of the ODN and, hence, the optical dynamic range at the OLT, at least for ONUs with PL. If all ONUs implement PL then all of the four optical parameters (OOC, OOB, isolation, overload) could be relaxed. However if there is a mix of ONUs with and without PL, then only the PSD requirements (OOC and OOB) will be able to be relaxed for the ONUs employing PL.
+
+## **D.4 OOC and OOB PSD relaxation**
+
+The PSD requirements in Tables 11-6 and 11-7 are based on the worst case dynamic range of upstream bursts as received at the S/R-CG point. If the apparent differential optical path loss of the ODN can be reduced, then the PSD levels may be relaxed, for ONUs with PL.
+
+In this example, it is possible to effectively reduce the apparent differential optical path loss of the ODN by up to 12 dB (15 dB ideal, minus 3 dB accuracy).
+
+Considering the maximum OOC2 PSD requirement of  $-45.7$  dBm/15 GHz and considering that the maximum ONU Tx power is  $+9$  dBm then the out of channel side mode suppression ratio (SMSR) requirement without PL is  $+9$  dBm  $- (-45.7$  dBm)  $= 54.7$  dB. Therefore the 12 dB PL allows a relaxation of SMSR to 42.7 dB. Note that OOB PSD benefits in the same way from this technique.
+
+Upon completion of autonomous PL, the ONU should send a message to the OLT after ranging to indicate it is operating PL mode and the level of PL it is using.
+
+## **D.5 OLT directed ONU power levelling**
+
+The directed mode applies only to ONUs that are capable of PL in excess of 12 dB, or if more precise control of PL is needed. If the PL values possible with the ONU autonomous method are insufficient for the laser being used, then an additional 6-9 dB of mitigation is possible via control by the OLT using the mechanisms provided in [ITU-T G.989.3].
+
+The directed PL mechanism requires functionalities belonging to the TC layer, such as the ONU capability to increase/reduce the transmitted power on the basis of downstream messages sent by the OLT. Such functionalities, as well as the capability to perform PL during initialization or as well as during operation, are for further study.
+
+## **D.6 ONU troubleshooting considerations**
+
+Without power levelling it is possible to determine whether an ONU is transmitting outside of PMD launch power requirements by locally measuring the optical power from the ONU using a PON power meter. For ONUs with PL this becomes somewhat more complicated. Conceivably, one might troubleshoot by measuring both the downstream and upstream powers at the ONU to determine if the ONU is transmitting outside of the range of the PMD tables for ONUs without PL. The downstream optical power measurement could be used to check if it is compliant with the PL rules described above. However, due to the limitations on accuracy of the RSSI reading at the ONU, there is scope for a significant difference in what the PON power meter will be detecting and what the ONU determines is being received. Furthermore, it is possible that, near the cross-over points of the ranges defined in clause D.3, that the insertion loss of the power meter could cause the ONU's RSSI signal to drop to the next range and result in the ONU Tx level being driven 3 dB higher. The above factors should be taken into account by network operators and system designers when designing troubleshooting procedures.
+
+# Appendix I
+
+## Wavelength considerations for NG-PON2, XG-PON1, G-PON and RF video overlay distribution services
+
+(This appendix does not form an integral part of this Recommendation.)
+
+When considering coexistence for NG-PON2, the following legacy PON systems were considered:
+
+- G-PON;
+- RF video overlay;
+- XG-PON1;
+- OTDR.
+
+The mapping of these wavelength bands for each system is graphically shown in Figure I.1 to provide an understanding of the considerations when coexisting with NG-PON2.
+
+![Figure I.1 – NG-PON2 wavelength plan – Coexistence representation. The figure consists of two horizontal wavelength maps. The top map shows the O-Band (1260-1360 nm) and E-Band (1360-1430 nm). It includes blocks for SMF cut-off, XG-PON1 U/S, GUARD BAND, GPON U/S, GUARD BAND, and a hatched area for 'Water peak for 2000 and later fibres <0.3 dB/KM limit'. The bottom map shows the S-Band (1430-1530 nm), C-Band (1530-1565 nm), L-Band (1565-1625 nm), and U-Band (1625-1650 nm). It includes blocks for GUARD BAND ITU-T G.984.5 (Info), GPON D/S, GUARD BAND ITU-T G.984.5 (Reqd), TWDM U/S, GUARD BAND, RF video, GUARD BAND ITU-T G.984.5 and ITU-T G.987.2, XG-PON1 D/S, GUARD BAND ITU-T G.987.2, TWDM D/S, PtP WDM SHARED SPECTRUM (incl. guard band), and OTDR. A blue bar at the top of the bottom map is labeled 'PtP WDM EXPANDED SPECTRUM'. The bottom right corner has the text 'G.989.2(14)_FI.1'.](86c32700ca76b0bc4154f5d9e07aab0e_img.jpg)
+
+Figure I.1 illustrates the wavelength plan for NG-PON2 coexistence. It is divided into two main horizontal spectral bars.   
+  
+The top bar covers the O-Band and E-Band:  
+
+- O-Band (1260-1360 nm): Contains SMF cut-off (pink), XG-PON1 U/S (blue), a GUARD BAND (hatched), GPON U/S (green), and another GUARD BAND (hatched).
+- E-Band (1360-1430 nm): Features a large hatched area labeled "Water peak for 2000 and later fibres <0.3 dB/KM limit".
+
+  
+The bottom bar covers the S-Band, C-Band, L-Band, and U-Band:  
+
+- S-Band (1430-1530 nm): Contains GUARD BAND ITU-T G.984.5 (Info) (hatched), GPON D/S (green), and GUARD BAND ITU-T G.984.5 (Reqd) (hatched).
+- C-Band (1530-1565 nm): Contains TWDM U/S (orange), GUARD BAND (hatched), and RF video (light orange).
+- L-Band (1565-1625 nm): Contains GUARD BAND ITU-T G.984.5 and ITU-T G.987.2 (hatched), XG-PON1 D/S (light blue), GUARD BAND ITU-T G.987.2 (hatched), TWDM D/S (dark orange), and PtP WDM SHARED SPECTRUM (incl. guard band) (blue). Above this section is a blue bar labeled "PtP WDM EXPANDED SPECTRUM".
+- U-Band (1625-1650 nm): Contains OTDR (light purple).
+
+  
+Wavelength markers (in nm) are provided along the bottom of each bar: 1260, 1280, 1290, 1310, 1330, 1340, 1360, 1430 (top bar); 1430, 1460, 1480, 1500, 1530, 1540, 1550, 1560, 1565, 1575, 1580, 1600, 1625, 1650 (bottom bar).
+
+Figure I.1 – NG-PON2 wavelength plan – Coexistence representation. The figure consists of two horizontal wavelength maps. The top map shows the O-Band (1260-1360 nm) and E-Band (1360-1430 nm). It includes blocks for SMF cut-off, XG-PON1 U/S, GUARD BAND, GPON U/S, GUARD BAND, and a hatched area for 'Water peak for 2000 and later fibres <0.3 dB/KM limit'. The bottom map shows the S-Band (1430-1530 nm), C-Band (1530-1565 nm), L-Band (1565-1625 nm), and U-Band (1625-1650 nm). It includes blocks for GUARD BAND ITU-T G.984.5 (Info), GPON D/S, GUARD BAND ITU-T G.984.5 (Reqd), TWDM U/S, GUARD BAND, RF video, GUARD BAND ITU-T G.984.5 and ITU-T G.987.2, XG-PON1 D/S, GUARD BAND ITU-T G.987.2, TWDM D/S, PtP WDM SHARED SPECTRUM (incl. guard band), and OTDR. A blue bar at the top of the bottom map is labeled 'PtP WDM EXPANDED SPECTRUM'. The bottom right corner has the text 'G.989.2(14)\_FI.1'.
+
+Figure I.1 – NG-PON2 wavelength plan – Coexistence representation
+
+For legacy PONs, see Appendix I of [ITU-T G.984.5] for a generic consideration of wavelength allocation for XG-PON1, G-PON and RF video overlay distribution services.
+
+# Appendix II
+
+## Physical layer measurements required to support optical layer supervision
+
+(This appendix does not form an integral part of this Recommendation.)
+
+The following information was taken from Appendix IV in Amendment 2 of [ITU-T G.984.2]. Note that in addition to some changed ranges, the method of calculating the values has also changed for some parameters. These changes are indicated in this appendix. These functions also apply to PtP WDM PON and further study is needed to tailor the requirements for PtP WDM PON.
+
+**Table II.1 – NG-PON2 optical digital diagnostic monitoring parameters**
+
+|                                        | Typical range<br>(Note 1) | Resolution      | Accuracy          | Repeatability          | Typical<br>response<br>time |
+|----------------------------------------|---------------------------|-----------------|-------------------|------------------------|-----------------------------|
+| Temperature – OLT and ONT              | –45 to +90 C              | 0.25 C          | ±3 C              | ±1 C                   | 1 s                         |
+| Voltage – OLT and ONT<br>(Note 4)      | 0 to 6.55 V               | 0.5% of nominal | ±3% of nominal    | ±1% of nominal         | 1 s                         |
+| Bias current – OLT and ONT<br>(Note 4) | 0 to 819 mA               | 1% of nominal   | ±10% of nominal   | ±5% of nominal         | 1 s                         |
+| ONT transmit power                     | –28 to +20 dBm            | 0.1 dB          | ±3 dB             | ±0.5 dB<br>(Note 2)    | 300 ns                      |
+| ONT receive power                      | –53 to –4.9 dBm           | 0.1 dB          | ±3 dB<br>(Note 5) | ±0.5 dB<br>(Note 2, 6) | 300 ns                      |
+| OLT transmit power                     | –28 to +20 dBm            | 0.1 dB          | ±2 dB             | ±0.5 dB<br>(Note 2)    | 300 ns                      |
+| OLT receive power<br>(Note 3)          | –53 to –4.9 dBm           | 0.1 dB          | ±2 dB<br>(Note 5) | ±0.5 dB<br>(Note 2, 6) | 300 ns                      |
+
+NOTE 1 – The typical range attempts to capture the most common range of parameters of an operational optical module. If a module has a different operational range, then the measurement range follows that range, augmented by the measurement inaccuracy on either end.
+
+NOTE 2 – ONT and OLT optical repeatability refers to multiple measurements taken when the true values of the ONT or OLT temperature and voltage are the same at the time of measurement. However, the normal range of those parameters is exercised in between tests as a means to gauge their aging effects.
+
+NOTE 3 – The OLT's measurement reflects the average power received during a burst. This requires the OLT to perform the measurement at the proper time with respect to the incoming burst, and that the burst is long enough to support the response time of the detector. The deviation due to non-50% duty cycle in the upstream data pattern is not to be charged against the measurement accuracy or repeatability specifications.
+
+NOTE 4 – Nominal refers to the design value of the quantity being measured (i.e., voltage or bias current) for the particular device implementation.
+
+NOTE 5 – Absolute accuracy is ±3 dB down to –35 dBm received optical power, and ±5 dB beyond –35 dBm.
+
+NOTE 6 – Repeatability < 0.5 dB down to –35 dBm optical power over 1-10 second measurement time.
+
+### Transmitter bias current modifications
+
+Originally, this parameter only covered laser "health" by monitoring the bias current to the laser. However, for NG-PON2 the parameters by which transmitter "health" is monitored has to be expanded. Currently the expectation is that some NG-PON2 solutions will encompass both EMLs and SOAs, which need to be monitored as well. Rather than adding more registers, this standard changes the single existing register into a multi-parameter register, by using the two most significant bits to code 3 types of information, as shown in Table II.2.
+
+**Table II.2 – Transmitter current monitor coding**
+
+| Bit 16 | Bit 15 | Description |
+|--------|--------|-------------|
+| 0      | 0      | Undefined   |
+| 0      | 1      | Laser bias  |
+| 1      | 0      | SOA current |
+| 1      | 1      | Undefined   |
+
+The remaining 14 bits allow for 16384 values to be defined, using 50  $\mu\text{A}$  (0.050 mA) steps.
+
+### Transmitter power modifications
+
+The modifications to this parameter are to extend the upper and lower measurement range by adjusting the step size. By changing the step size to 1.5  $\mu\text{W}$ , the ranges indicated in Table II.3 are supported.
+
+**Table II.3 – NG-PON2 optical digital diagnostic monitoring parameters**
+
+| <b>dBm</b> |   | <b><math>\mu\text{W}</math></b> |  | <b>Value</b> |
+|------------|---|---------------------------------|--|--------------|
+| -28.24     | = | 1.5                             |  | 0x00 0x01    |
+| -25.23     | = | 3.0                             |  | 0x00 0x02    |
+| $\vee$     |   |                                 |  | $\vee$       |
+| 0          | = | 1e3                             |  | 0x02 0x9A    |
+| 0.0065     | = | 1.0015e3                        |  | 0x02 0x9B    |
+| $\vee$     |   |                                 |  | $\vee$       |
+| +20        | = | 100e3                           |  | 0xFF 0xFF    |
+
+### Receiver power modifications
+
+The modifications to this parameter are also to extend the upper and lower measurement range by adjusting step size. Much lower values are indicated on the lower end of the range to facilitate tuning of the ONU tunable transmitter. The parameters are specified in two ranges to allow for reasonable implementations, as indicated in Table II.1. By selecting a 0.005  $\mu\text{W}$  resolution, the ranges indicated in Table II.4 are supported.
+
+**Table II.4 – NG-PON2 optical digital diagnostic monitoring parameters  
+with 0.005  $\mu\text{W}$  resolution**
+
+| <b>dBm</b> |   | <b><math>\mu\text{W}</math></b> |   | <b>Value</b> |
+|------------|---|---------------------------------|---|--------------|
+| -53        | = | 0.005                           | = | 0x00 0x01    |
+| -50        | = | 0.010                           | = | 0x00 0x02    |
+| -48.2      | = | 0.015                           | = | 0x00 0x03    |
+| V          |   |                                 |   | V            |
+| -27.972    | = | 1.595                           | = | 0x01 0x3F    |
+| -27.959    | = | 1.600                           | = | 0x01 0x40    |
+| -27.945    | = | 1.605                           | = | 0x01 0x41    |
+| V          |   |                                 |   | V            |
+| -4.84      | = | 327.7                           | = | 0xFF 0xFF    |
+
+# Appendix III
+
+## Allocation of the physical layer overhead time
+
+(This appendix does not form an integral part of this Recommendation.)
+
+(This appendix reference is only applicable for TWDM PON.)
+
+The physical layer overhead time ( $T_{plo}$ ) is used to accommodate five physical processes in the PON. These are: laser on/off time, timing drift tolerance, level recovery, clock recovery and start of burst delimitation. The exact division of the physical layer time to all these functions is determined partly by constraint equations and partly by implementation choices. This appendix reviews the constraints that the OLT must comply with, and suggests values for the discretionary values.
+
+The  $T_{plo}$  can be divided into three sections with respect to what ONU data pattern is desired. For simplicity, these times can be referred to as the guard time ( $T_g$ ), the preamble time ( $T_p$ ) and the delimiter time ( $T_d$ ). During  $T_g$ , the ONU will transmit no more power than the nominal zero level. During  $T_p$ , the ONU will transmit a preamble pattern that provides the desired transition density and signal pattern for fast level and clock recovery functions. Lastly, during  $T_d$ , the ONU will transmit a special data pattern with optimal autocorrelation properties that enable the OLT to find the beginning of the burst. An additional parameter of the control logic on the PON is the total peak-to-peak timing uncertainty ( $T_u$ ). This uncertainty arises from variations of the time of flight caused by the fibre and component variations with temperature and other environmental factors. Figure III.1 shows the timing relationship between the various physical layer overhead times. Table III.2 gives recommended values for  $T_g$ ,  $T_p$ ,  $T_d$  and  $T_{plo}$ .
+
+![Timing diagram showing the relationship between various physical layer overhead times (T_plo, T_u, T_on, T_off, T_g, T_p, T_d) between the end of one burst (ONU i) and the beginning of the next (ONU j).](1314748d1fff41b2d57a8ba9e9687c6a_img.jpg)
+
+The diagram illustrates the timing sequence for a burst transmission. It starts with the 'End of previous burst, ONU i' and ends at the 'Beginning of body, next burst, ONU j'. The total physical layer overhead time is  $T_{plo}$ . This is divided into three main sections: guard time ( $T_g$ ), preamble time ( $T_p$ ), and delimiter time ( $T_d$ ). The guard time  $T_g$  is the sum of the laser off time ( $T_{off}$ ) and the timing uncertainty ( $T_u$ ). The preamble time  $T_p$  is the sum of the laser on time ( $T_{on}$ ) and the timing uncertainty ( $T_u$ ). The delimiter time  $T_d$  is the time required for the ONU to find the beginning of the burst. The timing uncertainty  $T_u$  is the peak-to-peak timing uncertainty. The diagram also shows the relationship between the end of the previous burst and the start of the next burst, with the laser off time  $T_{off}$  and the timing uncertainty  $T_u$  being the key components.
+
+Timing diagram showing the relationship between various physical layer overhead times (T\_plo, T\_u, T\_on, T\_off, T\_g, T\_p, T\_d) between the end of one burst (ONU i) and the beginning of the next (ONU j).
+
+**Figure III.1 – Timing relationship between the various physical layer overhead times**
+
+The constraint equations with which the OLT must comply are then:
+
+$$T_g > T_{on} + T_u, \text{ and}$$
+
+$$T_g > T_{off} + T_u$$
+
+These equations can be explained as follows. The first equation makes sure that the following burst's laser on ramp-up does not fall on top of the last burst's data. The second equation makes sure that the last burst's laser off tail-off does not fall on top of the following burst's preamble.
+
+$T_p$  must be sufficient for the physical layer to recover the signal level (essentially, setting the decision threshold) and the signal clock phase. There are many diverse design approaches to these two problems, each with its own benefits and costs. Some designs are very fast, but require an external trigger signal and produce sub-optimal error performance. Other designs are slower, but do not require a reset signal and produce bit errors that are normally distributed. In addition, each of these designs may have special requirements on the data pattern used for the preamble. Some designs prefer a maximum transition density pattern, while others prefer a pattern with a balance of transitions and controlled runs of identical digits.
+
+Since the design is up to the OLT implementer, the OLT configures the details of the preamble that is transmitted by the ONU. This is part of the burst profile discussion below.
+
+T<sub>d</sub> must be long enough to provide a robust delimiter function in the face of bit errors. The error resistance of the delimiter depends on the exact implementation of the pattern correlator, but a simple approximate relationship between the number of bits in the delimiter (N) and the number of bit errors tolerated (E) is:
+
+$$E = \text{int}(N/4) - 1 \quad (\text{III-1})$$
+
+Equation III-1 has been empirically verified by a numerical search of all delimiters of sizes ranging from 8 to 32 bits. This search was performed under the assumption that the preamble pattern was a "1010" repeating pattern, and that the delimiter had an equal number of zeroes and ones. The Hamming distance, D, of the best delimiter from all shifted patterns of itself and the preamble was found to be  $D = \text{int}(N/2) - 1$ ; yielding the error tolerance shown.
+
+Given a certain BER, the probability of a severely errored burst (Pseb) is given by:
+
+$$Pseb = \binom{N}{E+1} BER^{E+1} \quad (\text{III-2})$$
+
+Substituting equation III-1 into equation III-2, the resultant Pseb is given by:
+
+$$Pseb = \binom{N}{\text{int}(N/4)} BER^{\text{int}(N/4)} \quad (\text{III-3})$$
+
+If the BER equals  $10^{-4}$ , the resultant Pseb for various delimiter lengths, N, is given in Table III.1. Inspection of this table shows that, in order to effectively suppress this kind of error, the delimiter length must be at least 16 bits long. The choice of delimiter length and pattern is made by the OLT as part of the burst profile.
+
+**Table III.1 – Probability of a severely errored burst as a function of delimiter length**
+
+| N  | Pseb                  |
+|----|-----------------------|
+| 8  | $2.8 \times 10^{-7}$  |
+| 12 | $2.2 \times 10^{-10}$ |
+| 16 | $1.8 \times 10^{-13}$ |
+| 20 | $1.5 \times 10^{-16}$ |
+| 24 | $1.3 \times 10^{-19}$ |
+| 32 | $1.1 \times 10^{-25}$ |
+| 64 | $4.9 \times 10^{-50}$ |
+
+With these considerations taken into account, the worst case and objective allocations of the physical layer overhead are given in Table III.2. This table also lists the values for the ONU transmitter enable time and transmitter disable time, and the total physical layer overhead time for reference. The worst-case values are intended to provide a reasonable bound for easy implementation, and the objective values are intended to be the design target for more efficient implementation with optimized components. These values are for a simple ODN without reach extenders. Reach extenders may require their own guard and preamble time allowances, making the total overhead larger.
+
+**Table III.2 – Recommended allocation of burst mode overhead time for TWDM PON OLT functions**
+
+|                                                     | Transmitter enable | Transmitter disable | Total time, $T_{plo}$ | Guard time, $T_g$ | Preamble time, $T_p$ | Delimiter time, $T_d$ |
+|-----------------------------------------------------|--------------------|---------------------|-----------------------|-------------------|----------------------|-----------------------|
+| 2.48832 Gb/s<br><i>Worst case</i> in bit times (ns) | 320<br>(128.6)     | 320<br>(128.6)      | 2048<br>(823.1)       | 512<br>(205.8)    | 1472<br>(610.9)      | 64<br>(25.7)          |
+| 2.48832 Gb/s<br><i>Objective</i> in bit time (ns)   | 64<br>(25.7)       | 64<br>(25.7)        | 512<br>(205.8)        | 128<br>(51.4)     | 320<br>(128.6)       | 32<br>(12.8)          |
+| 9.95328 Gb/s<br><i>Worst case</i> in bit times (ns) | 1280<br>(128.6)    | 1280<br>(128.6)     | 8192<br>(823.1)       | 2048<br>(205.8)   | 6080<br>(610.9)      | 64<br>(6.4)           |
+| 9.95328 Gb/s<br><i>Objective</i> in bit times (ns)  | 256<br>(25.7)      | 256<br>(25.7)       | 2048<br>(205.8)       | 512<br>(51.4)     | 1280<br>(128.6)      | 32<br>(3.2)           |
+
+In addition to the design dependent aspects of the burst overhead, there can be operationally dependent factors. For example, detecting an ONU's ranging burst is a more difficult problem than receiving an ONU's regular transmission. For another example, some ONUs may have higher power and are easier to detect, and therefore do not need FEC. For these reasons, the OLT may request different burst parameters depending on the context.
+
+The concept of a burst profile captures all the aspects of burst overhead control. A burst profile specifies the preamble pattern and length, the delimiter pattern and length, and whether FEC parity is sent. The OLT establishes one or more burst profiles, and then requests a particular burst profile for each burst transmission.
+
+The OLT has considerable latitude in setting up the profiles, because the OLT's burst receiver is sensitive to the profile parameters. Therefore, the OLT uses profiles that ensure adequate response in its burst mode receiver. However, some basic requirements from the ONU side must be met. Namely, the preamble and delimiter patterns are balanced and they have a reasonable transition density. If not, the ONU transmitter driver circuitry may be adversely affected. Also note that the preamble and delimiter patterns could differ in each profile, and this difference could be used by the OLT receiver as an in-band indication of the format of each burst (e.g., FEC active or not).
+
+The details of distributing the burst profiles and signalling their use will be described in the transmission convergence layer specification of the ITU-T G.989 series of Recommendations.
+
+# Appendix IV
+
+## **Jitter budget specifications for TWDM PON**
+
+(This appendix does not form an integral part of this Recommendation.)
+
+See Appendix IV in [ITU-T G.987.2].
+
+# Appendix V
+
+## **Measurement of TWDM PON burst mode acquisition time and burst node eye opening at OLT**
+
+(This appendix does not form an integral part of this Recommendation.)
+
+See Appendix V in [ITU-T G.987.2] for an example using 2.48832 Gbit/s in the upstream and 9.95328 Gbit/s in the downstream. The jitter budgets for 9.95328 Gbit/s in the upstream and 2.48832 Gbit/s in the downstream are for further study. This appendix reference is only applicable for TWDM PON.
+
+# Appendix VI
+
+## Nonlinear Raman interactions in optical fibres and mitigation technologies for coexistence of multiple PONs
+
+(This appendix does not form an integral part of this Recommendation.)
+
+This appendix provides background information on the issues related to operating multiple PON systems on the same fibre, specifically analysis of non-linearities and optical safety. Consideration is given to G-PON (as defined in [ITU-T G.984.2]), XG-PON1 (as defined in [ITU-T G.987.2]) and the NG-PON2 systems defined in this Recommendation. Additionally consideration is also given to RF video overlay.
+
+Nonlinear Raman interaction, i.e., stimulated Raman scattering (SRS), between optical waves propagating in a fibre is a well-known physical phenomenon that can give rise to two major undesirable effects: modulation crosstalk between the signals and power depletion of the signals at shorter wavelengths. The Raman gain spectrum in silica fibre extends to about 50 THz and the effects may be detectable between signals separated by as little as 1 THz or as much as 40 THz, as indicated in the Raman gain curve of Figure VI.1 for [ITU-T G.652] type of fibre.
+
+![Figure VI.1: Raman gain curve example for ITU-T G.652 type of fibre. The graph shows Raman gain (1/W*km) on the y-axis (0.0 to 0.8) versus Frequency (THz) on the x-axis (0 to 30). The curve starts at 0, rises to a peak of approximately 0.75 at 14 THz, then drops sharply to about 0.1 at 20 THz, and remains relatively flat around 0.1 until 30 THz. The title of the graph is 'For co-propagating, co-polarized signals'. A small label 'G.989.2(14)_FVI.1' is present in the bottom right corner of the plot area.](7f228001c8c028ac077fb5def89326e8_img.jpg)
+
+For co-propagating, co-polarized signals
+
+Raman gain (1/W\*km)
+
+Frequency (THz)
+
+G.989.2(14)\_FVI.1
+
+Figure VI.1: Raman gain curve example for ITU-T G.652 type of fibre. The graph shows Raman gain (1/W\*km) on the y-axis (0.0 to 0.8) versus Frequency (THz) on the x-axis (0 to 30). The curve starts at 0, rises to a peak of approximately 0.75 at 14 THz, then drops sharply to about 0.1 at 20 THz, and remains relatively flat around 0.1 until 30 THz. The title of the graph is 'For co-propagating, co-polarized signals'. A small label 'G.989.2(14)\_FVI.1' is present in the bottom right corner of the plot area.
+
+**Figure VI.1 – Raman gain curve example for ITU-T G.652 type of fibre**
+
+When modulation crosstalk occurs, modulation components of one optical signal are superimposed on another optical signal at a different wavelength, which can substantially impact the information being transmitted. Modulation crosstalk due to Raman interactions only occur between co-propagating optical signals.
+
+When optical power depletion occurs, signals at shorter wavelengths act as pump sources, i.e., experience power depletion, that amplify signals at longer wavelengths. If the optical power depletion is substantial, the quality of the transmitted information may suffer or the optical link reach may be impacted. Optical power depletion can occur in either co-propagating or counter-propagating waves in the fibre.
+
+### Mitigation techniques for nonlinear Raman interactions in optical fibres
+
+Although SRS is an unavoidable natural phenomenon, steps can be taken to minimize its negative impacts on a multi-wavelength optical communication system. Most obvious amongst these is the prudent selection of system wavelengths, optical launch powers and modulation formats. However, the choice of these parameters must be balanced so that other system performance requirements can be achieved as well. A number of SRS mitigation schemes have been proposed to alleviate performance impairments due to design constraints that would result in significant SRS impacts.
+
+The suggested SRS mitigation schemes include: high pass RF filtering, zero composite degree of polarization (DoP) interferer launch, dedicated transmitter and PSD shaping.
+
+**High pass RF filtering** of data signals prior to transmission (HighPassRF). The Raman crosstalk on a video RF optical carrier is primarily concerned with the lower frequency band of the RF spectrum of the TV channels. It has been proposed that the high pass filtering of the data modulation will greatly reduce the impairment caused by the SRS crosstalk while maintaining the data integrity (e.g., for a 9.95328 Gbit/s signal, attenuating the modulation spectrum below 200 MHz) With this technique, the significant attenuation of the low frequency components from the offending interferers' modulation spectra, prior to optical transmission, will reduce the RF modulation crosstalk problem and up to a 12 dB reduction in Raman crosstalk might be achievable. Figure VI.2 illustrates the HighPassRF scheme.
+
+![Figure VI.2: HighPassRF – Raman crosstalk suppression scheme utilizing RF high-pass filtering of the data modulation. The diagram shows a Video Modulator connected to a Video Optical Transmitter, which then connects to an Optical MUX. Three Data Modulators (Data Mod. 1, Data Mod. 2, Data Mod. 3) are each connected to a High pass filter, which then connects to a Data Optical Transmitter (Data 1, Data 2, Data 3). All Optical Transmitters (Video, Data 1, Data 2, Data 3) are connected to the Optical MUX. The output of the Optical MUX is labeled 'Combined optical signals to ODN'. The diagram is labeled G.989.2(14)_FVI.2.](8a781a0a8c956859f63a1ca7f2bb1644_img.jpg)
+
+The diagram illustrates the HighPassRF scheme. On the left, under the heading 'Electrical modulators', there is a 'Video Mod.' block and three 'Data Mod.' blocks labeled 'Data Mod. 1', 'Data Mod. 2', and 'Data Mod. 3'. The 'Video Mod.' block has an arrow pointing to a 'Video' block under the heading 'Optical transmitters'. The 'Data Mod.' blocks have arrows pointing to green 'High pass filters'. From each 'High pass filter', an arrow points to a 'Data' block under the 'Optical transmitters' heading, labeled 'Data 1', 'Data 2', and 'Data 3' respectively, with vertical ellipsis between 'Data 2' and 'Data 3'. All 'Optical transmitters' (Video, Data 1, Data 2, Data 3) have arrows pointing to a large trapezoidal 'Optical MUX' block. The output of the 'Optical MUX' is a yellow arrow pointing right, labeled 'Combined optical signals to ODN'. The diagram is labeled 'G.989.2(14)\_FVI.2' at the bottom right.
+
+Figure VI.2: HighPassRF – Raman crosstalk suppression scheme utilizing RF high-pass filtering of the data modulation. The diagram shows a Video Modulator connected to a Video Optical Transmitter, which then connects to an Optical MUX. Three Data Modulators (Data Mod. 1, Data Mod. 2, Data Mod. 3) are each connected to a High pass filter, which then connects to a Data Optical Transmitter (Data 1, Data 2, Data 3). All Optical Transmitters (Video, Data 1, Data 2, Data 3) are connected to the Optical MUX. The output of the Optical MUX is labeled 'Combined optical signals to ODN'. The diagram is labeled G.989.2(14)\_FVI.2.
+
+**Figure VI.2 – HighPassRF – Raman crosstalk suppression scheme utilizing RF high-pass filtering of the data modulation**
+
+**Zero composite DoP interferer launch (DoP0):** By arranging the polarization states of the SRS interferer signals so that their weighted Stokes vectors add to zero, one creates a statistical mixture of states (signals) whose composite DoP is also zero. This statistical mixture as a whole appears to any other signal that interacts with it to be un-polarized. The zero composite DoP state also happens to be the state of maximum entropy insofar as polarization is concerned. Therefore, except for some incidental variations due to the optical fibre's polarization mode dispersion, the composite DoP of the mixture will remain very close to zero as the mixture of interferer signals propagates through any span of optical fibre. Hence, the length averaged polarization overlap probability between the mixture of interferers with any other signal, such as the RF video overlay carrier, will remain very close to 0.5 for any fibre span. This implies that, as compared to the highly unlikely case of all the interferer signals being launched in parallel to one another (DoP = 1) and also to the RF video overlay signal (so that the polarization overlap probability is 1.0), the level of SRS crosstalk is 6 dB lower. Then, because of the 2:1 electrical to optical dB relationship, 3 dB more optical power could potentially be launched into the fibre for the zero composite DoP case as compared to the parallel launch 1.0 DoP case. Alternating the polarization states between two orthogonal states is one way of achieving a net weighted Stokes vector of zero. Another way is to arrange the polarization states so that the angle between consecutive Stokes vectors is  $360/n$ , where  $n$  is the number of interferers in the mixture (this assumes equal weights for the interferers). Figure VI.3 shows the DoP0 scheme.
+
+![Figure VI.3: DoP0 – Raman crosstalk suppression scheme utilizing alternating orthogonal polarization states to create a mixed state with a composite degree of polarization equal to zero. The diagram shows four input paths on the left: 'Video Mod.' (blue box), 'Data Mod. 1' (orange box), 'Data Mod. 2' (orange box), and 'Data Mod. 3' (orange box). Each modulator connects to an 'Optical transmitter' (blue box for Video, orange boxes for Data 1, 2, 3). The 'Video' transmitter outputs a blue line. The 'Data 1', 'Data 2', and 'Data 3' transmitters output orange lines that pass through 'Polarization controllers' (green boxes with diagonal lines). The 'Video' line and the orange lines from the polarization controllers enter an 'Optical MUX' (blue trapezoid). The output of the MUX is a yellow line labeled 'Combined optical signals to ODN'. A label 'G.989.2(14)_FVI.3' is at the bottom right.](9c80cf99954eb0142f694456d39fae4b_img.jpg)
+
+Figure VI.3: DoP0 – Raman crosstalk suppression scheme utilizing alternating orthogonal polarization states to create a mixed state with a composite degree of polarization equal to zero. The diagram shows four input paths on the left: 'Video Mod.' (blue box), 'Data Mod. 1' (orange box), 'Data Mod. 2' (orange box), and 'Data Mod. 3' (orange box). Each modulator connects to an 'Optical transmitter' (blue box for Video, orange boxes for Data 1, 2, 3). The 'Video' transmitter outputs a blue line. The 'Data 1', 'Data 2', and 'Data 3' transmitters output orange lines that pass through 'Polarization controllers' (green boxes with diagonal lines). The 'Video' line and the orange lines from the polarization controllers enter an 'Optical MUX' (blue trapezoid). The output of the MUX is a yellow line labeled 'Combined optical signals to ODN'. A label 'G.989.2(14)\_FVI.3' is at the bottom right.
+
+**Figure VI.3 – DoP0 – Raman crosstalk suppression scheme utilizing alternating orthogonal polarization states to create a mixed state with a composite degree of polarization equal to zero**
+
+The DoP0 scheme is useful for mitigating downstream coexisting system impacts (GPON, XG-PON1, RF video overlay, etc.). When utilized, the OLT laser and WM devices are polarization controlled. In the non-integrated case, the laser is 0 degree aligned to the connector alignment pin and the WM inputs are orthogonally aligned such that channel one is 0 degrees, channel two and channel three are 90 degrees and then alternating thereafter every two channels. Additionally, polarization maintaining fibres must be used between the OLT transmitter and WM.
+
+**Dedicated Raman crosstalk mitigation optical transmitter (DedicatedTx):** The basic scheme includes the addition to the existing system of a dedicated optical transmitter along with some passive elements at the OLT. The modulation on this dedicated Raman crosstalk suppression transmitter is appropriately prepared by the selection of its wavelength and launch power, and is also electrically modulated with properly polarized composite, yet bandwidth limited (e.g., 100 MHz for a 9.95328 Gbit/s data modulation) reproductions of the offending baseband digital modulation signals. This greatly simplifies the design of the composite modulation conditioning circuitry and also reduces the cost of the equalizer laser transmitter. The system utilizes destructive interference between the individual interferer transmitters' modulations and the terms of the composite modulation imparted upon the equalizer laser transmitter. This will effectively cancel the deleterious Raman crosstalk noise and restore the integrity of the transmitted video information. The proposed solution thereby allows for the coexistence of an optical carrier transporting television channels with co-propagating optical signals that are modulated with baseband digital traffic on the same optical distribution network. Utilizing the Raman crosstalk mitigation technology described here, the video carrier-to-Raman crosstalk ratio (CCR) can potentially be improved by 12 up to 14 dB at the low end of the RF frequency spectrum where the impact of this effect is most damaging. This system is equally effective at cancelling out the Raman crosstalk noise of incoherent or coherently related interferers. Figure VI.4 shows the DedicatedTx scheme.
+
+![Figure VI.4: DedicatedTx – Raman crosstalk cancellation scheme utilizing a dedicated crosstalk mitigation transmitter. The diagram shows multiple optical transmitters (Video, Data 1, Data 2, ..., Data n) connected to an Optical MUX. A Dedicated Raman Crosstalk Equalization Transmitter (DRCET) is shown, which includes a Photo receiver, Low pass filter, Equalization conditioning, Bandwidth limited composite equalization modulation, and a Raman equalization laser (λEq). The DRCET is connected to the Optical MUX via an Optical tap. The output of the Optical MUX is labeled 'Combined optical signals to ODN'. The diagram is labeled G.989.2(14)_FVI.4.](7b7596fb5ef925025341a9aacb6f2be7_img.jpg)
+
+The diagram illustrates a Raman crosstalk cancellation scheme. On the left, there are several input signals: 'Video Mod.' (Electrical modulator) leading to 'Video' (Optical transmitter), 'Data Mod. 1' leading to 'λ Data 1', 'Data Mod. 2' leading to 'λ Data 2', and 'Data Mod. n' leading to 'λ Data n'. These signals are combined in an 'Optical MUX'. A portion of the combined signal is tapped off via an 'Optical tap'. This tap signal is received by a 'Photo receiver' within a 'Dedicated raman crosstalk equalization transmitter' (DRCET) block. The signal then passes through a 'Low pass filter' and 'Equalization conditioning' block. The output of this block is sent to a 'Raman equalization laser λEq'. The output of the laser is then combined back into the main signal path by another 'Optical MUX'. The final output is labeled 'Combined optical signals to ODN'. The diagram is labeled 'G.989.2(14)\_FVI.4'.
+
+Figure VI.4: DedicatedTx – Raman crosstalk cancellation scheme utilizing a dedicated crosstalk mitigation transmitter. The diagram shows multiple optical transmitters (Video, Data 1, Data 2, ..., Data n) connected to an Optical MUX. A Dedicated Raman Crosstalk Equalization Transmitter (DRCET) is shown, which includes a Photo receiver, Low pass filter, Equalization conditioning, Bandwidth limited composite equalization modulation, and a Raman equalization laser (λEq). The DRCET is connected to the Optical MUX via an Optical tap. The output of the Optical MUX is labeled 'Combined optical signals to ODN'. The diagram is labeled G.989.2(14)\_FVI.4.
+
+**Figure VI.4 – DedicatedTx – Raman crosstalk cancellation scheme utilizing a dedicated crosstalk mitigation transmitter**
+
+**Power spectral density shaping (PSD-S):** The principle of this technique is to mitigate or avoid PSD overlapping between legacy binary PON signal (scrambled NRZ coding) and RF video overlay signal, by means of implementing flexible digital signalling processing (DSP) functions. DSP here is understood as a general purpose mechanism for information and symbol processing designated to perform spectrum shaping by appropriate pulse shaping, data rate [b-Kim], line code [b-Al-Qazwini], or modulation schemes. Figure VI.5 shows the impact of these factors on the SRS crosstalk. Figure VI.5 assumes 0 dBm at the receiver. Frequencies up to 300 MHz are the ones more directly affecting the crosstalk in systems with 10 to 20 km reach.
+
+The pulse repetition rate, related to the data rate, affects the PSD directly influencing the average power and introducing a set of dips in the power spectrum. The first frequency dips usually appear at frequencies related to the data rate. For NRZ, the dips appear at the baud rate frequency, for example, 2.5 Gbaud/s has the first dip at 2.5 GHz. Higher data rates for the same pulse shaping will result in lower PSDs at the lower frequencies and the appearance of the first dip at higher frequencies.
+
+Line coding can be also used to reshape the spectrum and further change the operational margins as what relates RF video overlay crosstalk. However, this solution usually requires an overhead which will result in bandwidth efficiency loss.
+
+When designing a system where RF video overlay coexistence is required, the potential impacts of all the above mentioned parameters need to be considered and the required margins may need to be recalculated. With tighter spectral control (done by a window function) and up-conversion (done by shifting the digital baseband signal to an upper spectrum location), the use of spectrum shaping therefore would enable a clearly separated and isolated signal spectrum that does not overlap with
+
+the spectral interference region of the RF signal, thus mitigating co-propagation Raman crosstalk effects in coexistence scenarios.
+
+In best practice, the DSP functions used for spectrum shaping can be integrated into current TWDM PON architecture by merging DSP logic into the transmission convergence adaptation sublayer (as shown in Figure VI.6). The DSP logic can be programmable and can be enabled or disabled for backward compatibility with NRZ coding. Moreover, the optics for TWDM PON can also be reused with proper optimization to accommodate such spectrum shaping. Since DSP functions can be flexibly selected and software-defined, many other non-NRZ coding schemes and digital filtering functions can also be supported in this architecture, leading to different levels of performance for particular applications.
+
+![Figure VI.5: Measured RF spectrum of several data rates, modulation formats and codings. The graph plots Power (dBm) from -75 to -25 against Frequency (MHz) from 50 to 600. Five curves are shown: 1.25 Gbps NRZ PRBS (solid black), 2.5 Gbps NRZ PRBS (solid red), 10 Gbps NRZ PRBS (solid blue), 1.25 Gbps QPSK PRBS (dotted black), and 10 Gbps NRZ 8B/10B (dashed blue). The 1.25 Gbps NRZ PRBS curve is the highest, starting around -37 dBm at 50 MHz and slightly decreasing. The 2.5 Gbps NRZ PRBS curve is around -40 dBm. The 10 Gbps NRZ PRBS curve is around -45 dBm. The 1.25 Gbps QPSK PRBS curve starts at -50 dBm and decreases to -63 dBm. The 10 Gbps NRZ 8B/10B curve starts at -70 dBm and increases to -50 dBm.](1f00478b5b295fba8ced45856b00de5e_img.jpg)
+
+Figure VI.5: Measured RF spectrum of several data rates, modulation formats and codings. The graph plots Power (dBm) from -75 to -25 against Frequency (MHz) from 50 to 600. Five curves are shown: 1.25 Gbps NRZ PRBS (solid black), 2.5 Gbps NRZ PRBS (solid red), 10 Gbps NRZ PRBS (solid blue), 1.25 Gbps QPSK PRBS (dotted black), and 10 Gbps NRZ 8B/10B (dashed blue). The 1.25 Gbps NRZ PRBS curve is the highest, starting around -37 dBm at 50 MHz and slightly decreasing. The 2.5 Gbps NRZ PRBS curve is around -40 dBm. The 10 Gbps NRZ PRBS curve is around -45 dBm. The 1.25 Gbps QPSK PRBS curve starts at -50 dBm and decreases to -63 dBm. The 10 Gbps NRZ 8B/10B curve starts at -70 dBm and increases to -50 dBm.
+
+**Figure VI.5 – Measured RF spectrum of several data rates, modulation formats and codings**
+
+![Figure VI.6: PDS shaping scheme utilizing integrated DSP logic architecture. The diagram shows a transmission path from left to right: Video Mod. (Electrical modulator) to video (Optical transmitter) to Optical MUX; Data Mod. 1 to DSP logic to Data 1 (Optical transmitter) to Optical MUX; Data Mod. 2 to DSP logic to Data 2 (Optical transmitter) to Optical MUX; ...; Data Mod. n to DSP logic to Data n (Optical transmitter) to Optical MUX. The Optical MUX outputs Combined optical signals to ODN. The reception path from right to left: Combined optical signals to ODN to Optical tunable filter to Data m (Optical receiver) to Data DeMod. m (Electrical demodulator) to DSP logic. A label 'Integrate DSP logics' is placed above the Data Mod. blocks.](886963464425186f4a465fa8155d2a3c_img.jpg)
+
+Figure VI.6: PDS shaping scheme utilizing integrated DSP logic architecture. The diagram shows a transmission path from left to right: Video Mod. (Electrical modulator) to video (Optical transmitter) to Optical MUX; Data Mod. 1 to DSP logic to Data 1 (Optical transmitter) to Optical MUX; Data Mod. 2 to DSP logic to Data 2 (Optical transmitter) to Optical MUX; ...; Data Mod. n to DSP logic to Data n (Optical transmitter) to Optical MUX. The Optical MUX outputs Combined optical signals to ODN. The reception path from right to left: Combined optical signals to ODN to Optical tunable filter to Data m (Optical receiver) to Data DeMod. m (Electrical demodulator) to DSP logic. A label 'Integrate DSP logics' is placed above the Data Mod. blocks.
+
+**Figure VI.6 – PDS shaping scheme utilizing integrated DSP logic architecture**
+
+# **Appendix VII**
+
+## **Cyclic AWG channel grid design examples**
+
+(This appendix does not form an integral part of this Recommendation.)
+
+This appendix has been deprecated.
+
+# Appendix VIII
+
+## Wavelength multiplexer, upstream inter-channel crosstalk, ONU transmitter tuning time considerations and upstream channel grid example
+
+(This appendix does not form an integral part of this Recommendation.)
+
+This appendix provides example information on the WM characteristics, upstream inter-channel crosstalk and its penalty related to the isolation specification of the WM device, along with ONU transmitter tuning time.
+
+### VIII.1 Wavelength multiplexer
+
+Table VIII.1 provides example values for the WM device. Isolation values may vary depending on the number of wavelength channels considered, the example given in Table VIII.1 is for an eight channel case. Critical to the proper definition of WM passband, consideration must be given to the maximum tuning error (MTE) of the associated laser. MTE is the maximum spectral error allowed due to tuning. MTE is the maximum differential spectral distance of the actual wavelength to the nominal centre of the wavelength channel. Specifically the relationship between MTE and MSE is shown in Figure VIII.1 and can be represented as a formula:
+
+$$\text{MTE} = \text{MSE} - (\text{minimum single-sided spectral width at } -15 \text{ dB}) \approx \text{MSE} - (\text{data rate in Hz})$$
+
+![Figure VIII.1: Relationship between MTE and MSE. The graph shows Power relative to peak (dB) on the y-axis (0 to -30) versus Offset from nominal central frequency (GHz) on the x-axis. Two transmitter spectra are shown, centered at the nominal central frequency. The distance from the nominal central frequency to the edge of the passband is labeled MSE. The distance from the nominal central frequency to the edge of the spectral width at -15 dB is labeled MTE. The minimum single-sided spectral width at -15 dB is indicated. The graph also shows the nominal central frequency minus maximum spectral excursion and the nominal central frequency plus maximum spectral excursion. A note indicates that the two examples of transmitter spectra are at their maximum frequency offset.](596fee0cab582cfa9ee3d008ff657854_img.jpg)
+
+Figure VIII.1 is a graph showing the relationship between Maximum Spectral Excursion (MSE) and Maximum Tuning Error (MTE) for a transmitter spectrum. The y-axis is 'Power relative to peak (dB)' ranging from 0 to -30. The x-axis is 'Offset from nominal central frequency (GHz)' with a central point at 0. Two transmitter spectra are shown, centered at the nominal central frequency. The distance from the nominal central frequency to the edge of the passband is labeled MSE. The distance from the nominal central frequency to the edge of the spectral width at -15 dB is labeled MTE. The minimum single-sided spectral width at -15 dB is indicated. The graph also shows the nominal central frequency minus maximum spectral excursion and the nominal central frequency plus maximum spectral excursion. A note indicates that the two examples of transmitter spectra are at their maximum frequency offset.
+
+Figure VIII.1: Relationship between MTE and MSE. The graph shows Power relative to peak (dB) on the y-axis (0 to -30) versus Offset from nominal central frequency (GHz) on the x-axis. Two transmitter spectra are shown, centered at the nominal central frequency. The distance from the nominal central frequency to the edge of the passband is labeled MSE. The distance from the nominal central frequency to the edge of the spectral width at -15 dB is labeled MTE. The minimum single-sided spectral width at -15 dB is indicated. The graph also shows the nominal central frequency minus maximum spectral excursion and the nominal central frequency plus maximum spectral excursion. A note indicates that the two examples of transmitter spectra are at their maximum frequency offset.
+
+Figure VIII.1 – Relationship between MTE and MSE
+
+**Table VIII.1 – WM characteristics**
+
+| Specification                                                                                                                                                                                                                      | Condition                                                 | Value                             |
+|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------|-----------------------------------|
+| Loss without connectors (Note)                                                                                                                                                                                                     | S/R-CPn to S/R-CG                                         | < 2.0 dB (Low)<br>< 4.0 dB (High) |
+| Isolation                                                                                                                                                                                                                          | S/R-CG to any S/R-CPn<br>(only applies to upstream ports) | FFS                               |
+| Maximum optical power                                                                                                                                                                                                              | Any individual port                                       | +23 dBm                           |
+| Return loss                                                                                                                                                                                                                        | Any port                                                  | > 50 dB                           |
+| Directivity                                                                                                                                                                                                                        | Any S/R-CPn to any S/R-CPn                                | > 50 dB                           |
+| NOTE – This is the loss without connectors when an ONU tunes to the peak wavelength $\pm$ MTE. When an ONU tunes around to maintain lock, it requires an amount of loss budget for the tuning process (which depends on the RSSI). |                                                           |                                   |
+
+NOTE – The optical parameter tables are specified at the S/R-CG & R/S points, as illustrated by Figure 6-1. In order to determine optical level at the S/R-CP point, the loss of WM must be taken into account. Table VIII.1 specifies two classes of loss for the WM, resulting in two different values. OLT transceivers indicate the compatible WM loss class (low or high). WM loss classes are likely to be technology based (e.g., AWG versus thin film filter).
+
+The following requirements apply to each operating channel of the OLT receive filter (WM):
+
+- 1) The  $(1+X)$  dB filter bandwidth<sup>2</sup> must be smaller than  $2 \cdot \text{MTE}$ , where  $X$  is the transmitter power wavelength dependency.
+- 2) The shape of the filter characteristic must be monotonically decreasing (apart from a limited ripple as specified below), on each side with respect to the filter minimum loss point, in the region delimited by the intersections with the adjacent channel filter responses extended by twice the MTE<sup>3</sup>, as shown in Figure VIII.3.
+- 3) The value of any residual ripple in the monotonic region specified above must be less than the OLT receive power measurement resolution.
+
+Requirement 1 guarantees that any unacceptable (i.e., exceeding the MTE) deviation of the ONU transmitter wavelength, with respect to the filter minimum loss point (nominally the channel centre), can always be revealed at the OLT receiver.
+
+Requirement 2 guarantees that the wavelength locking and tracking mechanism operation makes the ONU transmitter wavelength always move towards the filter minimum loss point (nominally the channel centre).
+
+Requirement 3 guarantees that any residual ripple on the receive filter shape causes power variations which are practically unmeasurable at the OLT receiver, hence that it cannot adversely affect the operation of the wavelength locking and tracking mechanism.
+
+Note that the maximum loss due to imperfect tuning (i.e., when the ONU locks at a distance equal to MTE away from the channel centre) coincides with the OLT receiver power measurements repeatability (total of 1 dB, according to Table VIII.2). In practice, however, the tuning error and tuning loss could be reduced by averaging the OLT receive power measurements.
+
+<sup>2</sup> Or, equivalently, the incremental loss caused by any wavelength deviation from the nominal channel wavelength greater than MTE must be greater than the OLT receive power measurement repeatability, which equals  $\pm 0.5$  dB (see Table VIII.2), plus the ONU power variation, which equals the transmitter power wavelength dependency.
+
+<sup>3</sup> This would require the additional specification of the ONU laser  $-15$  dB spectral width; alternatively, MTE could be conservatively replaced here by MSE.
+
+![Figure VIII.2: Requirement on filter bandwidth. A graph showing the OLT Rx filter characteristic (a bell-shaped curve) versus wavelength λ. The bandwidth is defined by the width at a power level below the peak, labeled as < 2 MTE. The peak power level is marked as OLT Rx power meas. Repeatability + max ONU Tx power variation. The diagram is labeled G.989.2(14)_FVIII.2. A legend at the bottom left indicates Tx- transmitter and Rx-receiver.](efedc464aaba06e85f269d26c98fee90_img.jpg)
+
+Figure VIII.2: Requirement on filter bandwidth. A graph showing the OLT Rx filter characteristic (a bell-shaped curve) versus wavelength λ. The bandwidth is defined by the width at a power level below the peak, labeled as < 2 MTE. The peak power level is marked as OLT Rx power meas. Repeatability + max ONU Tx power variation. The diagram is labeled G.989.2(14)\_FVIII.2. A legend at the bottom left indicates Tx- transmitter and Rx-receiver.
+
+**Figure VIII.2 – Requirement on filter bandwidth**
+
+![Figure VIII.3: Requirement on filter monotonicity. A graph showing the OLT Rx filter characteristic (a bell-shaped curve) versus wavelength λ. The filter is centered at λ_ch, with adjacent channels at λ_ch-1 and λ_ch+1. The region of monotonicity is highlighted in orange, centered around λ_ch. The distance from the center to the edges of this region is labeled MTE. The diagram is labeled G.989.2(14)_FVIII.3. A legend at the bottom left indicates Rx-receiver.](b8dc609f35d8251ff4e4ea111a9943bd_img.jpg)
+
+Figure VIII.3: Requirement on filter monotonicity. A graph showing the OLT Rx filter characteristic (a bell-shaped curve) versus wavelength λ. The filter is centered at λ\_ch, with adjacent channels at λ\_ch-1 and λ\_ch+1. The region of monotonicity is highlighted in orange, centered around λ\_ch. The distance from the center to the edges of this region is labeled MTE. The diagram is labeled G.989.2(14)\_FVIII.3. A legend at the bottom left indicates Rx-receiver.
+
+**Figure VIII.3 – Requirement on filter monotonicity**
+
+### **VIII.2 Upstream inter-channel crosstalk**
+
+Figure VIII.4 shows a simplified TWDM PON reference diagram excluding coexistence (i.e., no coexistence element Type x (CEx) device) which is used as the baseline to calculate the upstream inter-channel crosstalk and its penalty.
+
+![Figure VIII.4: Reference diagram for inter-channel crosstalk calculation. A schematic diagram of a TWDM PON. On the left, multiple NG-PON2 OLTs (OLT1, OLT2, OLT3, ..., OLTn) are connected to a Wavelength Multiplexer (WM) via their respective channels (λ1, λ2, λ3, ..., λn). The WM output is connected to a Power splitter. The Power splitter has multiple outputs, each connected to an ONU (ONU-1, ONU-2, ..., ONU-n) via a Repeater/Splitter (R/S). The distances from the Power splitter to the ONUs are labeled d2, dn, and d1. The differential path loss (dMAX) is indicated between the Power splitter and the ONUs. The diagram is labeled G.989.2(14)_FVIII.4.](26d0c0482ad7f4f026a58ecc0b468980_img.jpg)
+
+Figure VIII.4: Reference diagram for inter-channel crosstalk calculation. A schematic diagram of a TWDM PON. On the left, multiple NG-PON2 OLTs (OLT1, OLT2, OLT3, ..., OLTn) are connected to a Wavelength Multiplexer (WM) via their respective channels (λ1, λ2, λ3, ..., λn). The WM output is connected to a Power splitter. The Power splitter has multiple outputs, each connected to an ONU (ONU-1, ONU-2, ..., ONU-n) via a Repeater/Splitter (R/S). The distances from the Power splitter to the ONUs are labeled d2, dn, and d1. The differential path loss (dMAX) is indicated between the Power splitter and the ONUs. The diagram is labeled G.989.2(14)\_FVIII.4.
+
+**Figure VIII.4 – Reference diagram for inter-channel crosstalk calculation**
+
+Because of architectural asymmetry, ONUs can be located at different remote locations to have large differential optical path loss in the upstream direction, whereas NG-PON2 OLT ports are located near to each other to have no differential optical path loss in the downstream direction. The maximum differential optical path loss ( $d_{MAX}$ ) is specified as 15 dB as in Table 11-4.
+
+In this situation, the multichannel signal power spectrum at the S/R-CG point in front of WM device in the central office and the multichannel signal power spectrum at R/S point in front of each ONU can have quite different channel power differences as illustrated in Figure VIII.5.
+
+![Figure VIII.5 shows two signal power spectra. (a) Received signal power spectrum @ S/R-CG shows multiple peaks with a maximum differential optical path loss (d_MAX) of 15 dB and a power difference (ΔP_ONU) of 5 dB. (b) Received signal power spectrum @ R/S shows multiple peaks with a power difference (ΔP_OLT + Uniformity_WM) of 4 dB + 1.5 dB = 5.5 dB. The figure is labeled G.989.2(14)_FVIII.5.](1ef2b5e267d1196dd7375ea783d5ff59_img.jpg)
+
+Figure VIII.5 shows two signal power spectra. (a) Received signal power spectrum @ S/R-CG shows multiple peaks with a maximum differential optical path loss (d\_MAX) of 15 dB and a power difference (ΔP\_ONU) of 5 dB. (b) Received signal power spectrum @ R/S shows multiple peaks with a power difference (ΔP\_OLT + Uniformity\_WM) of 4 dB + 1.5 dB = 5.5 dB. The figure is labeled G.989.2(14)\_FVIII.5.
+
+**Figure VIII.5 – Signal power spectrum (a) at S/R-CG point and (b) at R/S point**
+
+According to Table 11-4, the difference between the mean launch power maximum and the mean launch power minimum of the OLT transmitter for the downstream direction ( $\Delta P_{OLT}$ ) is 4 dB. Considering typical 1.5 dB uniformity specification of the WM device ( $Uniformity_{WM}$ ), the maximum power difference among the downstream signals at the R/S point in front of ONU can be as high as 5.5 dB. However, in the upstream direction, the maximum differential optical path loss ( $d_{MAX}$ ) 15 dB can be added to the difference between the mean launch power maximum and the mean launch power minimum of the ONU transmitter ( $\Delta P_{ONU}$ ) 5 dB (per Table 11-5). And the maximum power difference among the upstream signals at the S/R-CG point in front of WM device can be as high as 20 dB.
+
+Since the upstream signal power difference at S/R-CG point in front of WM device can be much higher (14.5 dB higher) than the downstream signal power difference at R/S point in front of ONU, care must be taken when designing the WM device regarding the isolation specification in order to reduce the inter-channel crosstalk and its penalty.
+
+#### VIII.2.1 Worst-case design approach
+
+The upstream inter-channel crosstalk ( $C_c$ ) in worst-case design approach can be calculated using the following equation [b-ITU-T G.Sup39]:
+
+$$C_c = \Delta P_{ONU} + d_{MAX} + 10 \log_{10} \left( 2 \times 10^{-I_A/10} + (N-3) \times 10^{-I_{NA}/10} \right) \text{ dB}, \quad (\text{VIII-1})$$
+
+where  $I_A$  and  $I_{NA}$  are the adjacent channel isolation and the non-adjacent channel isolation of the WM device, respectively,  $N$  is total number of channels. And with Gaussian approximation the inter-channel crosstalk penalty ( $P_c$ ) can be calculated using the following equation [b-ITU-T G.Sup39]:
+
+$$P_c = -5 \log_{10} \left( \frac{10^{2C_c/10}}{N-1} \frac{Q^2}{Q^2 + 2 \cdot BER} \right) \text{ dB} \quad (\text{VIII-2})$$
+
+where  $Q = \sqrt{2} \operatorname{erfc}^{-1}(2 \times BER)$ .
+
+For an upstream BER of  $10^{-4}$  as specified in Table 11-6,  $Q = 3.72$ . The induced optical penalty at a linear extinction ratio of 0.16 (8 dB) is plotted against inter-channel crosstalk for the cases of total number of channel  $N = 4$  and  $N = 8$  in Figure VIII.6.
+
+![Figure VIII.6: Optical penalty against inter-channel crosstalk for N = 4 and N = 8. The graph plots Penalty (dB) on the y-axis (0 to 5) against Inter-channel crosstalk (dB) on the x-axis (-16 to 0). Two curves are shown: a solid black line for '4 ch. at Q = 3.72' and a dashed red line for '8 ch. at Q = 3.72'. Both curves show a sharp increase in penalty as crosstalk increases. Horizontal lines at 0.5 dB and 0.6 dB indicate the penalty levels for N=4 and N=8 respectively, at their respective crosstalk limits. Vertical lines at -8 dB and -6 dB indicate the crosstalk limits for N=4 and N=8 respectively. A legend box in the top left contains the curve descriptions. Below the x-axis, text specifies: N = 4, I_A = 32 dB, I_NA = 36 dB (in blue) and N = 8, I_A = 32 dB, I_NA = 36 dB (in red). The source code G.989.2(14)-Amd.2(17)_FVIII.6 is noted at the bottom right.](709203a3712ad0608d7f64dd69fa7db0_img.jpg)
+
+Figure VIII.6: Optical penalty against inter-channel crosstalk for N = 4 and N = 8. The graph plots Penalty (dB) on the y-axis (0 to 5) against Inter-channel crosstalk (dB) on the x-axis (-16 to 0). Two curves are shown: a solid black line for '4 ch. at Q = 3.72' and a dashed red line for '8 ch. at Q = 3.72'. Both curves show a sharp increase in penalty as crosstalk increases. Horizontal lines at 0.5 dB and 0.6 dB indicate the penalty levels for N=4 and N=8 respectively, at their respective crosstalk limits. Vertical lines at -8 dB and -6 dB indicate the crosstalk limits for N=4 and N=8 respectively. A legend box in the top left contains the curve descriptions. Below the x-axis, text specifies: N = 4, I\_A = 32 dB, I\_NA = 36 dB (in blue) and N = 8, I\_A = 32 dB, I\_NA = 36 dB (in red). The source code G.989.2(14)-Amd.2(17)\_FVIII.6 is noted at the bottom right.
+
+**Figure VIII.6 – Optical penalty against inter-channel crosstalk for N = 4 and N = 8**
+
+The calculated inter-channel crosstalk values and its penalties are summarized in Table VIII.2 for four channel systems and eight channel systems, with WM device examples of commercially available typical AWG, filter having tight isolation specification, and cascaded filter.
+
+**Table VIII.2 – Calculated inter-channel crosstalk and its penalty in worst-case design approach**
+
+| Worst-case design approach |         | Typical AWG                                         | Filter with tight spec.                             | Cascaded filter                                     |
+|----------------------------|---------|-----------------------------------------------------|-----------------------------------------------------|-----------------------------------------------------|
+|                            |         | $I_A = 23 \text{ dB}$ ,<br>$I_{NA} = 30 \text{ dB}$ | $I_A = 26 \text{ dB}$ ,<br>$I_{NA} = 33 \text{ dB}$ | $I_A = 32 \text{ dB}$ ,<br>$I_{NA} = 36 \text{ dB}$ |
+| 4 channel system           | Cc (dB) | 0.4                                                 | -2.6                                                | -8.2                                                |
+|                            | Pc (dB) | Infinite                                            | Infinite                                            | 0.5                                                 |
+| 8 channel system           | Cc (dB) | 1.8                                                 | -1.2                                                | -6                                                  |
+|                            | Pc (dB) | Infinite                                            | Infinite                                            | 0.6                                                 |
+
+In a worst-case design approach, a WM device with very high isolation specifications ( $I_A = 32 \text{ dB}$  and  $I_{NA} = 36 \text{ dB}$ ) is required for the TWDM PON to be reasonably bounded with optical penalty 0.6 dB added by the inter-channel crosstalk.
+
+#### VIII.2.2 Statistical design approach
+
+For the statistical design approach, the Monte Carlo simulation method is used to calculate the inter-channel crosstalk. The mean launch power of the ONU transmitter is assumed to have uniform random distribution with values varying from 4 dBm to 9 dBm (as per Table 11-6). The differential optical path loss is also assumed to have a uniform random distribution with values varying from 0 dB to 15 dB (as per Table 6-1). The inter-channel crosstalk probabilities calculated using a Monte
+
+Carlo simulation for the same WM device examples as in clause VIII.2.1 are illustrated in Figure VIII.7.
+
+![Figure VIII.7: Monte Carlo simulation for the probability of inter-channel crosstalk for (a) four channel system and (b) eight channel system. Both plots show Log (Cumulative probability) on the y-axis from 0.0 to -4.0 and Inter-channel crosstalk (dB) on the x-axis from -30 to 0. A horizontal green line at -2.52 (Log 0.3%) indicates the acceptance criteria. In (a), the curves for I_A = 23 dB, I_NA = 30 dB (black), I_A = 26 dB, I_NA = 33 dB (red), and I_A = 32 dB, I_NA = 36 dB (blue) intersect the acceptance line at -5, -8, and -13.5 dB respectively. In (b), the curves for I_A = 23 dB, I_NA = 30 dB (black), I_A = 26 dB, I_NA = 33 dB (red), and I_A = 32 dB, I_NA = 36 dB (blue) intersect the acceptance line at -4, -7, and -12 dB respectively.](e76a2834f1b3fc9987bab47ed9607caa_img.jpg)
+
+| System Type          | Device / Isolation Case                                 | Crosstalk at 0.3% (dB) |
+|----------------------|---------------------------------------------------------|------------------------|
+| (a) 4 channel system | I <sub>A</sub> = 23 dB, I <sub>NA</sub> = 30 dB (Black) | -5                     |
+|                      | I <sub>A</sub> = 26 dB, I <sub>NA</sub> = 33 dB (Red)   | -8                     |
+|                      | I <sub>A</sub> = 32 dB, I <sub>NA</sub> = 36 dB (Blue)  | -13.5                  |
+| (b) 8 channel system | I <sub>A</sub> = 23 dB, I <sub>NA</sub> = 30 dB (Black) | -4                     |
+|                      | I <sub>A</sub> = 26 dB, I <sub>NA</sub> = 33 dB (Red)   | -7                     |
+|                      | I <sub>A</sub> = 32 dB, I <sub>NA</sub> = 36 dB (Blue)  | -12                    |
+
+Figure VIII.7: Monte Carlo simulation for the probability of inter-channel crosstalk for (a) four channel system and (b) eight channel system. Both plots show Log (Cumulative probability) on the y-axis from 0.0 to -4.0 and Inter-channel crosstalk (dB) on the x-axis from -30 to 0. A horizontal green line at -2.52 (Log 0.3%) indicates the acceptance criteria. In (a), the curves for I\_A = 23 dB, I\_NA = 30 dB (black), I\_A = 26 dB, I\_NA = 33 dB (red), and I\_A = 32 dB, I\_NA = 36 dB (blue) intersect the acceptance line at -5, -8, and -13.5 dB respectively. In (b), the curves for I\_A = 23 dB, I\_NA = 30 dB (black), I\_A = 26 dB, I\_NA = 33 dB (red), and I\_A = 32 dB, I\_NA = 36 dB (blue) intersect the acceptance line at -4, -7, and -12 dB respectively.
+
+**Figure VIII.7 – Monte Carlo simulation for the probability of inter-channel crosstalk  
+for the cases (a) four channel system and (b) eight channel system**
+
+The calculated inter-channel crosstalk values and its penalties in case of statistical design approach are summarized in Table VIII.3 for four channel systems and eight channel systems, with WM device examples of commercially available typical AWG, filter having tight isolation specification, and cascaded filter. Here, a probability threshold for system acceptance of 0.3% is used to calculate the inter-channel crosstalk values and equation VIII-2 is used to calculate the penalties.
+
+**Table VIII.3 – Calculated inter-channel crosstalk and its penalty in  
+statistical design approach**
+
+| Statistical design approach |         | Typical AWG                                         | Filter with tight spec.                             | Cascaded filter                                     |
+|-----------------------------|---------|-----------------------------------------------------|-----------------------------------------------------|-----------------------------------------------------|
+|                             |         | $I_A = 23 \text{ dB}$ ,<br>$I_{NA} = 30 \text{ dB}$ | $I_A = 26 \text{ dB}$ ,<br>$I_{NA} = 33 \text{ dB}$ | $I_A = 32 \text{ dB}$ ,<br>$I_{NA} = 36 \text{ dB}$ |
+| 4 channel system            | Cc (dB) | −5                                                  | −8                                                  | −13.5                                               |
+|                             | Pc (dB) | 4.1                                                 | 0.5                                                 | 0                                                   |
+| 8 channel system            | Cc (dB) | −4                                                  | −7                                                  | −12                                                 |
+|                             | Pc (dB) | 1.9                                                 | 0.3                                                 | 0                                                   |
+
+Even in statistical design approach, a typical arrayed waveguide grating (AWG) cannot be used because of excessive inter-channel crosstalk. The WM device needs to be implemented using a filter with high isolation specifications in order for the TWDM PON to have reasonably bounded optical penalty 0.5 dB.
+
+#### VIII.2.3 Method to limit the inter-channel crosstalk impairment
+
+There could be two approaches to limit the inter-channel crosstalk impairment. One is to make the WM isolations high enough with given received signal power dynamic range in front of the WM device, either with worst-case design or with statistical design. The other is additionally to reduce
+
+the received signal power dynamic range ( $\Delta P_{CG}$ ) in front of the WM device by controlling ONU transmitter signal power depending on ODN insertion loss.
+
+There are also two different specification methods to limit the inter-channel crosstalk impairment. One is to specify the adjacent channel isolation ( $I_A$ ) and the non-adjacent channel isolation ( $I_{NA}$ ) of the WM device between S/R-CG point and S/R-CPn point. The other is to specify the inter-channel crosstalk ( $C_c$ ) at S/R-CPn point.
+
+Based on the calculation results in the previous clause, Table VIII.4 shows example methods and specifications to limit the inter-channel crosstalk penalty as 0.5 dB or below.
+
+**Table VIII.4 – Example methods and specifications to give 0.5 dB inter-channel crosstalk penalty**
+
+| Specification method      | Specifying the WM isolations only |                    | Specifying the WM isolations and received signal power dynamic range | Specifying inter-channel crosstalk |
+|---------------------------|-----------------------------------|--------------------|----------------------------------------------------------------------|------------------------------------|
+|                           | Worst-case design                 | Statistical design | Worst-case design                                                    |                                    |
+| Parameter                 |                                   |                    |                                                                      |                                    |
+| $I_A$ , minimum           | 32                                | 26                 | 23                                                                   | NA                                 |
+| $I_{NA}$ , minimum        | 36                                | 33                 | 30                                                                   | NA                                 |
+| $\Delta P_{CG}$ , maximum | NA                                | NA                 | 11                                                                   | NA                                 |
+| $C_c$ , maximum           | NA                                | NA                 | NA                                                                   | -8                                 |
+
+## VIII.3 ONU transmitter tuning time
+
+The ONU transmitter wavelength channel tuning time may be measured using the procedure and test set-up below. The purpose of the test set-up is to measure the tuning time unambiguously. The tuning of the laser is illustrated below in Figure VIII.8.
+
+![Figure VIII.8 – Illustration of laser tuning across the operating band. The graph shows power versus wavelength. A blue curve represents the laser's power during tuning, starting from a peak at the 'Tuning time measurement start' and ending at a peak at the 'Tuning time measurement stop'. A horizontal blue arrow labeled 'Wavelength change' spans between these two points. Vertical dashed lines mark the start and stop points. Horizontal dashed lines indicate a 0.5 dB drop from the initial peak power at the start and a 0.5 dB rise to the final peak power at the stop. The x-axis is labeled 'Wavelength' and the figure code 'G.989.2(14)_FVIII.8' is shown in the bottom right.](fe2b982e7b73e8c8d5ba45509c306882_img.jpg)
+
+Figure VIII.8 – Illustration of laser tuning across the operating band. The graph shows power versus wavelength. A blue curve represents the laser's power during tuning, starting from a peak at the 'Tuning time measurement start' and ending at a peak at the 'Tuning time measurement stop'. A horizontal blue arrow labeled 'Wavelength change' spans between these two points. Vertical dashed lines mark the start and stop points. Horizontal dashed lines indicate a 0.5 dB drop from the initial peak power at the start and a 0.5 dB rise to the final peak power at the stop. The x-axis is labeled 'Wavelength' and the figure code 'G.989.2(14)\_FVIII.8' is shown in the bottom right.
+
+**Figure VIII.8 – Illustration of laser tuning across the operating band**
+
+The tuning time as shown in the illustration does not begin when the laser begins to tune but when the laser exits the passband of the origin wavelength channel, i.e., when the optical power drops of 0.5 dB compared to the initial value, after a channel change signal in the form required by the tunable device. The tuning time ends when the laser enters the passband of the destination wavelength channel, i.e., when the optical power, in the destination wavelength channel, reaches and stays within 0.5 dB of the initial (origin channel) value. The transmitter wavelength channel
+
+tuning time is computed over all possible channel changes in the tuning range. A reference channel demultiplexer is used in the test set-up. It is required that the laser power variation during the channel change and the attenuation uniformity between channels of the reference channel demultiplexer are each below 0.25 dB.
+
+The test set-up is shown in Figure VIII.9, while Figure VIII.10 illustrates how the tuning time parameter is measured.
+
+![Figure VIII.9: Test set-up for tuning time of ONU transmitter. The diagram shows a block diagram of the test setup. A 'Tunable optical transmitter' is connected to an 'Attenuator', which is connected to a 'Splitter'. The output of the splitter is divided into two parallel paths. Each path contains an 'Optical filter' (labeled 'Optical filter - λ1' and 'Optical filter - λ2'), an 'O/E converter', and a 'Waveform monitor' (labeled 'Waveform monitor λ1' and 'Waveform monitor λ2'). The outputs of the two waveform monitors are summed in a summation box labeled 'Σ'. The text 'G.989.2(14)_FVIII.9' is present at the bottom right of the diagram.](235e996e83e7d5198cf9d909f5713cdd_img.jpg)
+
+Figure VIII.9: Test set-up for tuning time of ONU transmitter. The diagram shows a block diagram of the test setup. A 'Tunable optical transmitter' is connected to an 'Attenuator', which is connected to a 'Splitter'. The output of the splitter is divided into two parallel paths. Each path contains an 'Optical filter' (labeled 'Optical filter - λ1' and 'Optical filter - λ2'), an 'O/E converter', and a 'Waveform monitor' (labeled 'Waveform monitor λ1' and 'Waveform monitor λ2'). The outputs of the two waveform monitors are summed in a summation box labeled 'Σ'. The text 'G.989.2(14)\_FVIII.9' is present at the bottom right of the diagram.
+
+**Figure VIII.9 – Test set-up for tuning time of ONU transmitter**
+
+![Figure VIII.10: Optical power vs. time from summation of waveform monitors. The figure consists of two vertically stacked plots sharing a common horizontal 'Time' axis. The top plot shows 'Central wavelength' on the vertical axis. A blue curve represents the wavelength over time, showing a sharp transition from one central wavelength to another. The bottom plot shows 'Power sum' on the vertical axis. A blue curve represents the power sum over time, showing a dip during the wavelength transition. Vertical dashed lines indicate the start and end of the tuning process. The start is marked by a 'Wavelength tuning command' arrow, and the end is marked by 'Stable/maximum measured power'. The text 'G.989.2(14)_FVIII.10' is present at the bottom right of the figure.](37b60927a495651a09fddd8861e70a20_img.jpg)
+
+Figure VIII.10: Optical power vs. time from summation of waveform monitors. The figure consists of two vertically stacked plots sharing a common horizontal 'Time' axis. The top plot shows 'Central wavelength' on the vertical axis. A blue curve represents the wavelength over time, showing a sharp transition from one central wavelength to another. The bottom plot shows 'Power sum' on the vertical axis. A blue curve represents the power sum over time, showing a dip during the wavelength transition. Vertical dashed lines indicate the start and end of the tuning process. The start is marked by a 'Wavelength tuning command' arrow, and the end is marked by 'Stable/maximum measured power'. The text 'G.989.2(14)\_FVIII.10' is present at the bottom right of the figure.
+
+**Figure VIII.10 – Optical power vs. time from summation of waveform monitors**
+
+The test set up attenuator is set such that the optical received power at the optical-to-electrical (O/E) converters is in range that is not close to receiver overload and the signal is high enough to be accurately measured. The laser is initially tuned to within 0.1 dB of the minimum loss point of the filter. A threshold is set at 0.5 dB below the resulting initial power measurement. The crossing of this threshold will be used to determine the points where the tuning time begins and when the tuning time ends, i.e., the signal stays above the threshold.
+
+The optical power levels are converted and measured at the output of the summation box in the electrical domain.
+
+Note that the same test procedure can be applied even when the transmitter module is integrated in a system and the channel change command is issued via higher layers, e.g., common layer interface (CLI) or element management system (EMS). However it must be understood that other effects may influence the measurement in this case, for example, the transmitter may be switched off before tuning initiates and switched on again when tuning finishes. Hence the test procedure can be applied, e.g., to compare the tuning time of different ONUs, excluding command transmission and processing delays, but the tuning time of the optical module itself is measured when the optical
+
+module is not part of a system and the channel change is commanded via the specific signal required by the optical module.
+
+The reference test demultiplexer is Gaussian in shape and have a relative loss of 0.5 dB at 8 GHz from the minimum loss point.
+
+## VIII.4 TWDM PON upstream channel grid examples
+
+Two upstream channel grid examples are provided: an on-grid example an off-grid example. The off-grid example supports a single bi-directional AWG at the wavelength mux, a potentially desirable feature.
+
+Table VIII.5 shows examples of the TWDM PON on-grid upstream channel assignments which contain eight channels with 50 GHz, 100 GHz and 200 GHz channel spacing. The examples are sub-wavelength bands from the ITU-T grid, which is described in clause 6 of [ITU-T G.694.1].
+
+**Table VIII.5 – TWDM PON upstream channel on-grid example**
+
+| Channel | 50 GHz CS       |                 | 100 GHz CS      |                 | 200 GHz CS      |                 |
+|---------|-----------------|-----------------|-----------------|-----------------|-----------------|-----------------|
+|         | Frequency (THz) | Wavelength (nm) | Frequency (THz) | Wavelength (nm) | Frequency (THz) | Wavelength (nm) |
+| 1       | 195.25          | 1535.43         | 195.6           | 1532.68         | 196.1           | 1528.77         |
+| 2       | 195.20          | 1535.82         | 195.5           | 1533.47         | 195.9           | 1530.33         |
+| 3       | 195.15          | 1536.22         | 195.4           | 1534.25         | 195.7           | 1531.90         |
+| 4       | 195.10          | 1536.61         | 195.3           | 1535.04         | 195.5           | 1533.47         |
+| 5       | 195.05          | 1537.00         | 195.2           | 1535.82         | 195.3           | 1535.04         |
+| 6       | 195.00          | 1537.40         | 195.1           | 1536.61         | 195.1           | 1536.61         |
+| 7       | 194.95          | 1537.79         | 195.0           | 1537.40         | 194.9           | 1538.19         |
+| 8       | 194.90          | 1538.19         | 194.9           | 1538.19         | 194.7           | 1538.77         |
+
+Table VIII.6 shows examples of the TWDM PON off-grid upstream channel assignments which contain 8 channels with 50 GHz, 100 GHz and 200 GHz channel spacing. The examples are off grid of the sub-wavelength bands from the ITU-T grid. Note that the frequencies are exact, wavelengths are approximate.
+
+**Table VIII.6 – TWDM PON upstream channel off-grid example**
+
+| Channel | 51.2 GHz CS     |                 | 104.2 GHz CS    |                 | 208.4 GHz CS    |                 |
+|---------|-----------------|-----------------|-----------------|-----------------|-----------------|-----------------|
+|         | Frequency (THz) | Wavelength (nm) | Frequency (THz) | Wavelength (nm) | Frequency (THz) | Wavelength (nm) |
+| 1       | 195.226         | 1535.619        | 195.591         | 1532.756        | 196.112         | 1528.684        |
+| 2       | 195.174         | 1536.029        | 195.486         | 1533.573        | 195.903         | 1530.310        |
+| 3       | 195.122         | 1536.439        | 195.382         | 1534.391        | 195.695         | 1531.940        |
+| 4       | 195.069         | 1536.849        | 195.278         | 1535.210        | 195.486         | 1533.574        |
+| 5       | 195.017         | 1537.260        | 195.174         | 1536.030        | 195.278         | 1535.211        |
+| 6       | 194.965         | 1537.671        | 195.069         | 1536.851        | 195.069         | 1536.852        |
+| 7       | 194.913         | 1538.082        | 194.965         | 1537.672        | 194.861         | 1538.496        |
+| 8       | 194.861         | 1538.494        | 194.861         | 1538.495        | 194.652         | 1540.143        |
+
+### VIII.5 Detail of OOC near the channel band edge
+
+In NG-PON2, the ONU transmitter is subject to the out of channel (OOC) requirement. Namely, there are two levels of OOC: OOC1 is determined by the incoherent crosstalk that will occur when the interfering light is outside the victim channel bandwidth, and OOC2 is determined by the coherent crosstalk that will occur when the interfering light is within the victim channel bandwidth. This is shown in Figure 9-1, which is reproduced below as Figure VIII.11.
+
+![Figure VIII.11 – OOC-PSD mask definition. The diagram shows a Power Spectral Density (PSD) mask with a central peak at f0. The peak has a width of ± MSE and a height of Pmax - 15 dB (0.01 nm resolution). The mask is divided into two levels: OOC1 (incoherent crosstalk) and OOC2 (coherent crosstalk). The OOC1 level is the higher power level outside the channel, and the OOC2 level is the lower power level inside the channel. The frequency axis is marked with f2, f1, f0, f1, f2. The distance from f0 to f1 is CS/2, and from f1 to f2 is CS. The mask is defined by G.989.2(19)_FVIII.11.](9b91dbfe5949fa9a6216c2599aa95290_img.jpg)
+
+Figure VIII.11 – OOC-PSD mask definition. The diagram shows a Power Spectral Density (PSD) mask with a central peak at f0. The peak has a width of ± MSE and a height of Pmax - 15 dB (0.01 nm resolution). The mask is divided into two levels: OOC1 (incoherent crosstalk) and OOC2 (coherent crosstalk). The OOC1 level is the higher power level outside the channel, and the OOC2 level is the lower power level inside the channel. The frequency axis is marked with f2, f1, f0, f1, f2. The distance from f0 to f1 is CS/2, and from f1 to f2 is CS. The mask is defined by G.989.2(19)\_FVIII.11.
+
+Figure VIII.11 – OOC-PSD mask definition
+
+One will note that the edges between the OOC1 and OOC2 are perfectly sharp. The transition from coherent to incoherent crosstalk would be sharp only with a perfectly monochromatic signal; however, our signals are modulated which leads to their spectrum being broadened. This will have the effect of softening the edges between the two cases.
+
+The signal that is being interfered with is a NRZ waveform intensity modulated on an optical carrier. The NRZ waveform classically is a  $\text{sinc}(f)$  function. However, to make the calculation simpler, we can model the spectrum as a  $\text{rect}(f)$  function that is 15 GHz wide (for a 7.5 GHz electrical bandwidth). Assuming a close to perfect extinction ratio, half the power goes into modulation, and the other half is the optical carrier, which is represented by a  $\delta(f)$  function. This can be written:
+
+$$\text{PSD}(f) = 1/2 \delta(f-f_0) + 1/2 \text{sinc}((f-f_0)/15 \text{ GHz})$$
+
+The worst case carrier placement is when the  $f_0$  is 7.5 GHz (or more) from the band edge. Then, the allowed interference power at any frequency can be calculated by integrating over every part of the PSD that is within 7.5 GHz of the interference frequency. Also keep in mind that the incoherent crosstalk is always present also, and so much be added (linearly) to the result.
+
+The figure below gives a representative calculation of the allowable out of channel PSD as a function of frequency difference from the band edge. In this case, we are looking at a left edge of a channel. This assumes that the OOC1 is  $-40.4 \text{ dBm}$  and the OOC2 is  $-41.6 \text{ dBm}$ . The OOC requirement starts at the OOC1 value, and starting at 7.5 GHz from outside the band edge, the OOC declines linearly to one quarter of the difference between the levels. Then there is a step down to three quarters of the difference – this is due to the optical carrier coming into range. Then the crosstalk continues its decline until it reaches the OOC2 value at 7.5 GHz inside the band. One can see that just inside the band, the allowed power is about 0.3 dB higher (easier) than the OOC2 level. However, just outside the band, the crosstalk is about 0.3 dB lower (harder) than the OOC1 level. This means that the OOC1 must be tightened by that amount.
+
+![Line graph titled 'Modulation effect on OOC1 - OOC2 edges' showing interpolated OOC values (dB) vs. offset from band edge (GHz). The graph shows a sharp drop at 0 GHz offset between OOC1 and OOC2 levels.](8d91c13d9c584af8129133d91ecb4bb9_img.jpg)
+
+The graph illustrates the modulation effect on OOC1 and OOC2 edges. The y-axis represents 'Interpolated OOC values (dB)' ranging from -41.8 to -40.4 in 0.2 dB increments. The x-axis represents 'Offset from band edge (GHz)' ranging from -10 to 10 in 2 GHz increments. The curve starts at approximately -40.5 dB at -10 GHz (labeled OOC1), remains relatively flat until about -8 GHz, then gradually decreases to -40.75 dB at 0 GHz. At 0 GHz, there is a sharp vertical drop to -41.3 dB. From -41.3 dB, the curve gradually decreases further to -41.6 dB at 8 GHz (labeled OOC2) and remains flat until 10 GHz. A small text label 'G.989.2(19)\_FVIII.12' is located in the bottom right corner of the plot area.
+
+| Offset from band edge (GHz) | Interpolated OOC values (dB) |
+|-----------------------------|------------------------------|
+| -10                         | -40.5                        |
+| -8                          | -40.5                        |
+| -6                          | -40.6                        |
+| -4                          | -40.65                       |
+| -2                          | -40.7                        |
+| 0                           | -40.75                       |
+| 0                           | -41.3                        |
+| 2                           | -41.35                       |
+| 4                           | -41.4                        |
+| 6                           | -41.5                        |
+| 8                           | -41.6                        |
+| 10                          | -41.6                        |
+
+Line graph titled 'Modulation effect on OOC1 - OOC2 edges' showing interpolated OOC values (dB) vs. offset from band edge (GHz). The graph shows a sharp drop at 0 GHz offset between OOC1 and OOC2 levels.
+
+**Figure VIII.12 – The modulation effect on OOC band edges**
+
+As a practical matter, the difference between the two OOC values is not as high as first calculated. Therefore, the impact of this interpolation between the two values is not big, and most likely could be ignored to first order in any testing.
+
+# Appendix IX
+
+## Alternative line code for Raman mitigation
+
+(This appendix does not form an integral part of this Recommendation.)
+
+This appendix provides examples of NG-PON2 Raman mitigation coding schemes when using RF video overlay. Two example schemes are provided, an 8B10B scheme and a Miller code scheme, both defined in this appendix. These codes will have to be compatible with the optical devices conforming to the NRZ based values shown in Table 11-4 and Table 11-5.
+
+As described in their respective sections, each scheme uses a different approach to effect the mitigation. The advantage of 8B10B code is that it adds functionality into the media access control (MAC) layer, that is able to be turned on or off per the application. The advantage of Miller code is that it is contained inside the optical modules, thereby providing a standard NRZ based signal to the MAC. Each code provides different mitigation levels and potentially optical budget performance, so selection of either code can be application dependent.
+
+### IX.1 8B10B scheme
+
+For Raman mitigation, the 8B10B sublayer is introduced between the downstream NG-PON2 physical interface (PHY) adaption interface and the optical interfaces.
+
+8B10B is a DC balanced encoding scheme introduced by Widmer-Franaszek in 1984. The transmission codes are further specified in [b-IEEE 802.3], clause 36.2.4 and are identical to ANSI [b-ANSI 230-1994] (FC-PH), clause 11. The NG-PON2 8B10B sublayer uses all the code-groups of Table 36-1 of [b-IEEE 802.3] and uses only the K28.5 code-group specified in Table 36-2 of [b-IEEE 802.3].
+
+The 8B10B sublayer is independent of all other NG-PON2 MAC functions.
+
+#### IX.1.1 Power spectral density of 8B10B code
+
+Figure IX.1 presents simulated results of the PSD of traditional NRZ at 10 Gbit/s and the ANSI 8B10B code at 12.5 Gbit/s.
+
+![PSD plot showing Power spectral density in dB/Hz versus Frequency (Hz) for NRZ and 8B10B codes.](9ab8ed615ae503cf1b4da66bff9c18a9_img.jpg)
+
+The figure is a line graph titled "PSD plot". The y-axis is labeled "Power spectral density in dB/Hz" and ranges from -140 to -105 in increments of 5. The x-axis is labeled "Frequency (Hz)" and ranges from 0 to 15, with a multiplier of  $\times 10^9$  at the bottom right. There are two curves: a blue line representing "NRZ @ ~10 G" and a green line representing "8B10B @ ~12.5 G". The blue curve starts at approximately -106 dB/Hz at 0 Hz, remains relatively flat until about 2.5 GHz, then gradually decreases, reaching a sharp minimum of about -135 dB/Hz at 10 GHz, before rising to about -120 dB/Hz at 15 GHz. The green curve starts at approximately -114 dB/Hz at 0 Hz, rises to a peak of about -108 dB/Hz at 2.5 GHz, then gradually decreases, reaching a sharp minimum of about -140 dB/Hz at 12.5 GHz, before rising to about -125 dB/Hz at 15 GHz. A small label "G.989.2(14)\_FIX.1" is present in the bottom right corner of the plot area.
+
+PSD plot showing Power spectral density in dB/Hz versus Frequency (Hz) for NRZ and 8B10B codes.
+
+Figure IX.1 – Power spectral density of NRZ and 8B10B codes
+
+#### IX.1.2 Encode and decode operations
+
+##### IX.1.2.1 OLT encode
+
+For the OLT, the 8B10B sublayer is responsible for encoding and performs the following encoding operations
+
+For the first octet of the downstream physical synchronization block (PSBd) physical synchronization sequence (PSync) field (0xC5) the special code-group K28.5 is chosen from Table 36-2 of [b-IEEE 802.3]. Once the code-group is selected, the current value of the transmitter's running disparity is used to select the code-group from its corresponding column. For each code-group transmitted, a new value of the running disparity is calculated. This new value is used as the transmitter's current running disparity for the next octet to be encoded and transmitted.
+
+With the exception of the first octet of the PSBd PSync field (0xC5), valid code-groups are selected using the NG-PON2 PMD octets as indexes into Table 36-1 of [b-IEEE 802.3]. Once the code-group is selected, the current value of the transmitter's running disparity is used to select the code-group from its corresponding column. For each code-group transmitted, a new value of the running disparity is calculated. This new value is used as the transmitter's current running disparity for the next octet to be encoded and transmitted.
+
+##### IX.1.2.2 ONU decode
+
+For the ONU, the 8B10B sublayer is responsible for decoding and performs the following operations
+
+Syncs to the K28.5 character code-group: Synchronization is performed using the receiver state description of [b-ANSI 230-1994] (FC-PH), clause 12.1.
+
+Replace the octet associated with the K28.5 group with the original PSync PSBd value of 0xC5,
+
+Replace the octet associated with received the data code-group with the associated octet.
+
+##### IX.1.2.3 Running disparity rules
+
+After powering on or exiting a test mode, the transmitter assumes the negative value for its initial running disparity. Upon transmission of any code-group, the transmitter calculates a new value for its running disparity based on the contents of the transmitted code-group.
+
+After powering on or exiting a test mode, the receiver assumes either the positive or negative value for its initial running disparity. Upon the reception of any code-group, the receiver determines whether the code-group is valid or invalid and calculates a new value for its running disparity based on the contents of the received code-group.
+
+The following rules for running disparity are used to calculate the new running disparity value for code-groups that have been transmitted (transmitter's running disparity) and that have been received (receiver's running disparity).
+
+Running disparity for a code-group is calculated on the basis of sub-blocks, where the first six bits (abcdei) form one sub-block (six-bit sub-block) and the second four bits (fghj) form the other sub-block (four-bit sub-block). Running disparity at the beginning of the six-bit sub-block is the running disparity at the end of the last code-group. Running disparity at the beginning of the four-bit sub-block is the running disparity at the end of the six-bit sub-block. Running disparity at the end of the code-group is the running disparity at the end of the four-bit sub-block.
+
+Running disparity for the sub-blocks is calculated as follows:
+
+- Running disparity at the end of any sub-block is positive if the sub-block contains more ones than zeros. It is also positive at the end of the six-bit sub-block if the six-bit sub-block is 000111, and it is positive at the end of the four-bit sub-block if the four-bit sub-block is 0011.
+
+- Running disparity at the end of any sub-block is negative if the sub-block contains more zeros than ones. It is also negative at the end of the six-bit sub-block if the six-bit sub-block is 111000, and it is negative at the end of the four-bit sub-block if the four-bit sub-block is 1100.
+
+Otherwise, running disparity at the end of the sub-block is the same as at the beginning of the sub-block.
+
+NOTE – All sub-blocks with equal numbers of zeros and ones are disparity neutral. In order to limit the run length of 0's or 1's between sub-blocks, the 8B/10B transmission code rules specify that sub-blocks encoded as 000111 or 0011 are generated only when the running disparity at the beginning of the sub-block is positive; thus, running disparity at the end of these sub-blocks is also positive. Likewise, sub-blocks containing 111000 or 1100 are generated only when the running disparity at the beginning of the sub-block is negative; thus, running disparity at the end of these sub-blocks is also negative.
+
+##### IX.1.2.4 Checking the validity of received code-groups
+
+The following rules are used to determine the validity of received code-groups:
+
+The column in Tables 36-1 and 36-2 of [b-IEEE 802.3] corresponding to the current value of the receiver's running disparity is searched for the received code-group.
+
+If the received code-group is found in the proper column, according to the current running disparity, then the code-group is considered valid and, for data code-groups, the associated data octet determined (decoded).
+
+If the received code-group is not found in that column, then the code-group is considered invalid.
+
+Independent of the code-group's validity, the received code-group is used to calculate a new value of running disparity. The new value is used as the receiver's current running disparity for the next received code-group.
+
+Detection of an invalid code-group does not necessarily indicate that the code-group in which the invalid code-group was detected is in error. Invalid code-groups may result from a prior error which altered the running disparity of the PHY bit stream but which did not result in a detectable error at the code-group in which the error occurred.
+
+The number of invalid code-groups detected is proportional to the BER of the link. Optical link error monitoring may be performed by counting invalid code-groups.
+
+#### IX.1.3 Eye mask and PMD
+
+The eye mask of the OLT transmitter when encoded with the 8B10B code is the same as shown in Figure 11-3. However, there are potential direct impacts to the PMD parameters of ER and receiver sensitivity when using 8B10B at 12.5 Gbit/s with 10 Gbit/s compliant transceiver components. In addition to direct impacts of the reduction in ER, there are indirect impacts on other parameters that are ER dependent, e.g., in-band crosstalk penalty.
+
+The impact on effective ONU receiver sensitivity is not specified, but must be accounted for in equipment applying the 8B10B technique. As allowed by Note 3 in the downstream PMD Tables 11-4 and 11-5, this impact can be compensated for with an appropriate increase in minimum mean channel launch power of the OLT transmitter.
+
+### IX.2 Miller and Miller squared scheme
+
+Miller code (also called delay modulation, or modified frequency modulation) is a run length limited code where at least two and at most four consecutive like symbols may occur in the transmitted sequence. More specifically, in Miller code, a bit 1 is represented by a transition at the middle of the bit period and there is no transition for bit 0 unless it is followed by another bit 0, in which case there is a transition at the end of the first bit 0. Based on Miller code, Miller squared code (also called Miller-Miller code, or  $M^2$  code) was developed to provide DC balance. Miller
+
+squared code adopts all the Miller code rules and adds one addition rule that when an even number of bit 0's occurs between bit 0's, the transition for the last bit 1 is suppressed. Encoding and decoding of Miller and Miller squared codes can be easily implemented with synchronous logic circuit. Figure IX.2 shows an example of coding binary data into Miller code. These codes (Miller and Miller squared) provide good timing content and reduced bandwidth compared to NRZ code. In addition, the PSD at low frequencies is relatively low with the potential for Raman crosstalk mitigation.
+
+![Figure IX.2: Miller code waveform for the bit sequence 0 1 0 1 1 1 1 0 0 0 1 0 0 1 1 0. The waveform shows transitions between high and low levels. Red vertical lines indicate bit intervals. The label G.989.2(14)_FIX.2 is present at the bottom right.](801306729c5725ff06ca853a9139cd0b_img.jpg)
+
+Figure IX.2: Miller code waveform for the bit sequence 0 1 0 1 1 1 1 0 0 0 1 0 0 1 1 0. The waveform shows transitions between high and low levels. Red vertical lines indicate bit intervals. The label G.989.2(14)\_FIX.2 is present at the bottom right.
+
+**Figure IX.2 – Miller code**
+
+#### IX.2.1 Modified definitions for Miller code
+
+##### IX.2.1.1 Minimum extinction ratio
+
+With respect to a Miller code signal generated by an optical transmitter, the ER is defined as the average optical power level at the centre of the high level (*A*) to the average optical power level at the centre of the low level (*B*):
+
+$$ER = 10 \log_{10} (A/B)$$
+
+Note that the high and low levels in Miller code are simply the corresponding optical signal levels, and the Miller code specifies how to map the optical signal into its data signal.
+
+##### IX.2.1.2 Launch optical power without input to the transmitter
+
+In the upstream direction, the ONU transmitter ideally launches no power into the fibre in all bursts which are not assigned to that ONU. However, an optical power level less than or equal to the WNE-PSD is allowed during bursts which are not assigned to that ONU. During the transmitter Enable bit period immediately preceding the assigned burst, which may be used for laser pre-bias, and during the bit period immediately following the disable of the TxEnable signal, the maximum launch power level allowed is the low level.
+
+![Figure IX.3: Test set-up for mask of the eye diagram for ONU transmitter. The block diagram shows: Optical transmitter -> Attenuator a) -> O/E converter fourth-order Thomson filter b) -> Waveform monitor. The label G.989.2(14)_FIX.3 is present at the bottom right.](0815887c5918cf1ba7b3a1cdab3d154f_img.jpg)
+
+Figure IX.3: Test set-up for mask of the eye diagram for ONU transmitter. The block diagram shows: Optical transmitter -> Attenuator a) -> O/E converter fourth-order Thomson filter b) -> Waveform monitor. The label G.989.2(14)\_FIX.3 is present at the bottom right.
+
+<sup>a)</sup> Attenuator is used if necessary.
+
+<sup>b)</sup> Cut-off frequency (3 dB attenuation frequency) of the filter is 0.75 times output nominal bit rate.
+
+**Figure IX.3 – Test set-up for mask of the eye diagram for ONU transmitter**
+
+#### IX.2.2 Power spectral density of Miller code
+
+Miller coding scheme can be modelled as a Markov source with four states with equal stationary state probability. Based on the state transition matrix and the autocorrelation for the Miller code, its PSD can be found as:
+
+$$S(\omega) = \frac{2}{\omega^2 T [17 + 8 \cos 4\omega T]} \cdot [23 - 2 \cos \omega T/2 - 22 \cos \omega T - 12 \cos 3\omega T/2 + 5 \cos 2\omega T + 12 \cos 5\omega T/2 + 2 \cos 3\omega T - 8 \cos 7\omega T/2 + 2 \cos 4\omega T],$$
+
+where  $\omega$  is the angular frequency and  $T$  is the bit period. Figure IX.4 shows the PSDs of the NRZ and Miller line codes. Compared to NRZ modulation, Miller code has a narrower bandwidth and reduced energy content at low frequencies. These are the desired properties for TWDM PONs. With reduced energy at low frequencies, Miller code can mitigate the Raman crosstalk of the TWDM PON signals onto the RF video overlay. With narrower bandwidth, Miller code can also reduce the fibre dispersion penalty. Hence, a DML, instead of an EML (electro-absorption modulated laser), can be used at 9.95328 Gbit/s for TWDM PON downstream transmission in the L-band or upstream transmission in the C band.
+
+![Figure IX.4: Power spectral density of NRZ and Miller codes. The graph plots Power spectral density (dB) on the y-axis (from -40 to 0) against Normalized frequency (f·T) on the x-axis (from 0 to 2). The NRZ curve (blue) starts at -5 dB at f·T=0, drops to -40 dB at f·T=1, and returns to -5 dB at f·T=2. The Miller curve (red) starts at -15 dB at f·T=0, peaks at 0 dB at f·T=0.25, drops to -18 dB at f·T=1, peaks at -12 dB at f·T=1.75, and drops to -40 dB at f·T=2.](4c86e4dfdc04db280a2a1ab345358130_img.jpg)
+
+Figure IX.4: Power spectral density of NRZ and Miller codes. The graph plots Power spectral density (dB) on the y-axis (from -40 to 0) against Normalized frequency (f·T) on the x-axis (from 0 to 2). The NRZ curve (blue) starts at -5 dB at f·T=0, drops to -40 dB at f·T=1, and returns to -5 dB at f·T=2. The Miller curve (red) starts at -15 dB at f·T=0, peaks at 0 dB at f·T=0.25, drops to -18 dB at f·T=1, peaks at -12 dB at f·T=1.75, and drops to -40 dB at f·T=2.
+
+**Figure IX.4 – Power spectral density of NRZ and Miller codes**
+
+#### IX.2.3 Encode and decode operations
+
+Even though encoding and decoding of Miller and Miller squared codes can be easily implemented with synchronous logic circuit, there exists a potential time/phase ambiguity in the reception and decoding of Miller coded waveform. For example, as shown in Figure IX.2, with a clock phase shift of 180 degree, consecutive 1 bits will be decoded as consecutive 0 bits, or vice versa. The only unambiguous pattern is the 101 bit combination. Under the wrong phase shift of 180 degree, the waveform appears to be two consecutive 0 bits without a transition between them. This is a code violation, and it can be used to correct 180-degree phase alignment error.
+
+Alternatively, phase alignment error can be detected by counting the number of transition edges or using parity check. According to the coding rule, there is always a transition in the middle of 1 bit, while at the bit boundaries, transition only happens between two consecutive 0 bits. Hence, for random data, the transition density in the middle of the bits is twice the transition density at the bit boundaries. In addition to looking for transition density, the parity between 0 and 1 can also be used for phase alignment. As a transition in the middle of the bit period is decoded as 1 bit, while no transition in the middle of the bit period is decoded as 0 bit. If the alignment is out of phase by 180 degree, the transition density in the middle of the bit period, for random data, is reduced to a half of that with correct phase alignment. In other words, the number of decoded 1 bits will be half of the decoded 0 bits.
+
+In addition to look at bit pattern and transition density, fixed data pattern in the PON protocol, such as the PSync in the downstream and the preamble in upstream, can be used for phase alignment. For example, the downstream PSync pattern is 0xC5E5 1840 FD59 BB49 in XG-PON1. With 180-degree phase alignment error at the receiver, the 101 patterns in the PSync appear to be coding violations, and the decoded PSync field becomes a wrong pattern. With 180 degree phase alignment
+
+error at the receiver for upstream, code violations appear for the commonly used 1010... pattern. To maximize the number of transitions in Miller code waveform, 0000 or 1111 preamble in upstream is preferred. In this case, the OLT receiver with 180 degree phase alignment error will decode the 0000 preamble as 1111, and the 1111 preamble as 0000.
+
+![Block diagram of an optical transceiver for NRZ and Miller codes. The transmitter path starts with 'NRZ data to be transmitted' entering a 'Miller encoder'. A 'Line code select' signal (indicated by a dashed line) controls the encoder. The output of the encoder goes to a 'DML or EML driver', which then connects to a 'DML or EML' block, resulting in the 'Transmitted signal'. The receiver path starts with the 'Received signal' entering a 'Photodiode', followed by a 'TIA' (Transimpedance Amplifier) and an 'LA' (Limiting Amplifier). The output of the LA is split: one path goes to a 'Miller decoder' and the other to a 'CDR for NRZ data'. Both are controlled by a 'Line code detection' block. The outputs of the Miller decoder and CDR for NRZ data are combined to produce the 'Recovered NRZ data'.](796573504cfca9cbe974cf7a125c0494_img.jpg)
+
+Block diagram of an optical transceiver for NRZ and Miller codes. The transmitter path starts with 'NRZ data to be transmitted' entering a 'Miller encoder'. A 'Line code select' signal (indicated by a dashed line) controls the encoder. The output of the encoder goes to a 'DML or EML driver', which then connects to a 'DML or EML' block, resulting in the 'Transmitted signal'. The receiver path starts with the 'Received signal' entering a 'Photodiode', followed by a 'TIA' (Transimpedance Amplifier) and an 'LA' (Limiting Amplifier). The output of the LA is split: one path goes to a 'Miller decoder' and the other to a 'CDR for NRZ data'. Both are controlled by a 'Line code detection' block. The outputs of the Miller decoder and CDR for NRZ data are combined to produce the 'Recovered NRZ data'.
+
+**Figure IX.5 – Optical transceiver for NRZ and Miller codes**
+
+Since the Miller code is a binary code and its bandwidth is narrower than the NRZ code, conventional transmitter and receiver front end circuits commonly used in NRZ transceivers can be reused for Miller code. Therefore, it is possible to design a transceiver that can transmit and receive both NRZ and Miller coded signals, as shown in Figure IX.5. The transceiver will use the same analogue front end (i.e., laser driver at the transmitter side, transimpedance amplifier and limiting amplifier at the receiver side) for both NRZ and delay modulation signals. At the transmitter side, a line code select signal will switch the Miller encoder in and out of the signal path. The line code select signal comes from the line card to set the line code to be used in the system. At the receiver side, a line code detection signal will switch the received signal either to the clock and data recovery (CDR) circuit for NRZ code or decoder for Miller code. The line code detection circuit can be implemented in a number of approaches with the same logic function. It is up to the implementer to choose it.
+
+The line code detection circuit could have two filters; one lowpass filter passes frequencies from DC to  $0.2/T$ , and the other bandpass filter passes frequencies from  $0.4/T$  to  $0.6/T$ , where  $T$  is the bit period. A comparator will compare the power measured after these two filters. If the power after the bandpass filter is much larger than the power after the lowpass filter, Miller code is selected.
+
+The line code detection circuit will count the maximum number of identical and consecutive symbols. If the maximum number of identical and consecutive symbols is significantly larger than four, the line code is determined to be NRZ.
+
+The line code detection circuit will look at the duration between two transitions. If there exists a large number of occurrences that the duration between two transitions is one and a half bit period, the line code is determined to be Miller code.
+
+The transceiver will decode the received signal as NRZ and Miller code, and then the line code detection circuit will select the correct line code based on which code leads to correct data in the protocol specific pattern (e.g., PSync in the downstream or the preamble in the upstream).
+
+The transceiver will decode the received signal as NRZ and Miller code, and then send both decoded data to FEC (feedforward correction). The line code selection circuit will select the line code that produces the least number of error bits from FEC. This approach requires FEC block before the line code can be selection. However, implementing a FEC circuit inside optical
+
+transceiver is not a common practice, so this approach is less suitable for dual line code transceivers.
+
+Using such a transceiver with NRZ and Miller line codes, the interface between the transceiver and TWDM PON MAC remains the conventional NRZ code. Hence, MAC layer can remain untouched regardless of the line code used in the system, but TWDM PON system becomes adaptive to the deployment scenarios. If the TWDM PON system coexists with RF video overlay service, Miller code can be used to mitigate the Raman crosstalk. If there is no RF video overlay service, either NRZ or Miller code can be used.
+
+With Miller code, any violation in the received line code could indicate an error bit. As the locations of the error bits are known based on line code violation, this information can be used for error detection or correction. For example, it can improve the performance of FEC. In this case, the transceiver can be designed to detect code violation and report the error bits to the FEC.
+
+#### IX.2.4 Eye mask
+
+Figure IX.6 presents the eye mask of the OLT transmitter when encoded with the Miller code. The values are  $X = 0.15$ ,  $Y = 0.25$ .
+
+![Figure IX.6 – Miller encoded eye mask. The graph shows multiple overlapping blue waveforms representing the eye mask. The vertical axis is labeled with 1+Y, 1, 1-Y, Y, 0, and -Y. The horizontal axis is labeled with 0, X, 0.5-X, 0.5+X, 1-X, and 1. Two solid blue rectangular blocks are positioned symmetrically in the center, representing the eye opening. Dashed horizontal lines are drawn at Y=0 and Y=1. A small label 'G.989.2(14)_FIX.6' is at the bottom right of the plot area.](558e8decddf44d5f246b09396086ce02_img.jpg)
+
+Figure IX.6 – Miller encoded eye mask. The graph shows multiple overlapping blue waveforms representing the eye mask. The vertical axis is labeled with 1+Y, 1, 1-Y, Y, 0, and -Y. The horizontal axis is labeled with 0, X, 0.5-X, 0.5+X, 1-X, and 1. Two solid blue rectangular blocks are positioned symmetrically in the center, representing the eye opening. Dashed horizontal lines are drawn at Y=0 and Y=1. A small label 'G.989.2(14)\_FIX.6' is at the bottom right of the plot area.
+
+Figure IX.6 – Miller encoded eye mask
+
+### IX.3 Raman mitigation suppression levels
+
+Table IX.1 provides an example of required Raman mitigation for class N2 and the specified number of wavelengths. The numbers are based on a typical operator RF video overlay scheme, with the following assumptions:
+
+- a polarization overlap factor of 0.6;
+- 256-quadrature amplitude modulation (QAM) RF video.
+
+**Table IX.1 – Required mitigation**
+
+| Class                                                                                      | Budget | <b>Required mitigation</b> |              |
+|--------------------------------------------------------------------------------------------|--------|----------------------------|--------------|
+|                                                                                            |        | 4 Wavelength               | 8 Wavelength |
+| N2                                                                                         | 31 dB  | 6 dB                       | FFS          |
+| NOTE – Required mitigation is to allow 1 dB penalty in overall CNR due to Raman cross talk |        |                            |              |
+
+# Appendix X
+
+## Upstream PMD examples for TWDM PON
+
+(This appendix does not form an integral part of this Recommendation.)
+
+This appendix provides examples of the single-rate PMD sublayer and the single data path dual-rate coexistence PMD sublayer of NG-PON2. Note that dual rate is not explicitly mentioned in the requirements of [ITU-T G.989.1] and are shown below as examples only.
+
+The topology for single-rate PMD sublayer is shown in Figure X.1. Optical signals transmitted to PMD sublayer are received by the single rate receiver, then transmitted through a single rate transimpedance amplifier (TIA) to a single rate limiting amplifier. The output of the limiting amplifier is then sent on to the PMA interface.
+
+![Figure X.1: Example of single-rate PMD data path. The diagram shows a signal flow from left to right. An input line labeled 'From upstream PON channel' enters a dashed box labeled 'PMD'. Inside the box, the signal passes through a 'Single rate receiver' (represented by a D-shaped symbol), then a 'Single rate TIA' (represented by a triangle), and finally a 'Single rate LA' (represented by a triangle). The output of the LA exits the dashed box and is labeled 'To single rate PMA interface'. Below the dashed box, the text 'G.989.2(14)-Amd.2(17)_FX.1' is present.](0bbbad069459da54c1cdef84c90b316a_img.jpg)
+
+Acronyms:
+
+Figure X.1: Example of single-rate PMD data path. The diagram shows a signal flow from left to right. An input line labeled 'From upstream PON channel' enters a dashed box labeled 'PMD'. Inside the box, the signal passes through a 'Single rate receiver' (represented by a D-shaped symbol), then a 'Single rate TIA' (represented by a triangle), and finally a 'Single rate LA' (represented by a triangle). The output of the LA exits the dashed box and is labeled 'To single rate PMA interface'. Below the dashed box, the text 'G.989.2(14)-Amd.2(17)\_FX.1' is present.
+
+TIA - Transimpedance amplifier  
+LA - Limiting amplifier  
+MUX - Multiplexer
+
+**Figure X.1 – Example of single-rate PMD data path**
+
+There are two types of topologies for the reference design of dual-rate transceivers in the OLT upstream direction. As shown in Figure X.2, from a topological point of view, optical signals transmitted to the PMD layer are received by a dual rate receiver, then transmitted through a dual rate TIA. For the signals which are the output of the dual rate TIA, there exist two different processing methods as described below:
+
+![Figure X.2 shows two diagrams (a and b) illustrating dual-rate coexistence PMD implementation with a single data path. Diagram (a) shows a 'Dual rate receiver' connected to a 'Dual rate TIA', which then branches into a '10G LA' and a '2.5G LA'. These outputs are combined in a 'High speed MUX' (2:1) controlled by 'RATE_SELECT', leading to a 'To dual_rate PMA interface'. Diagram (b) shows a 'Dual rate receiver' connected to a 'Dual rate TIA', which then connects to a 'Dual rate LA' controlled by 'RATE_SELECT', leading to a 'To dual_rate PMA interface'. Both diagrams are labeled 'PMD' and 'From upstream PON channel'. A reference 'G.989.2(14)-Amd.2(17)_FX.2' is present. Below the diagrams is an acronym list: TIA - Transimpedance amplifier, LA - Limiting amplifier, MUX - Multiplexer.](dd00cc2325415c09afb8bf178f60f33b_img.jpg)
+
+Acronyms:  
+TIA - Transimpedance amplifier  
+LA - Limiting amplifier  
+MUX - Multiplexer
+
+Figure X.2 shows two diagrams (a and b) illustrating dual-rate coexistence PMD implementation with a single data path. Diagram (a) shows a 'Dual rate receiver' connected to a 'Dual rate TIA', which then branches into a '10G LA' and a '2.5G LA'. These outputs are combined in a 'High speed MUX' (2:1) controlled by 'RATE\_SELECT', leading to a 'To dual\_rate PMA interface'. Diagram (b) shows a 'Dual rate receiver' connected to a 'Dual rate TIA', which then connects to a 'Dual rate LA' controlled by 'RATE\_SELECT', leading to a 'To dual\_rate PMA interface'. Both diagrams are labeled 'PMD' and 'From upstream PON channel'. A reference 'G.989.2(14)-Amd.2(17)\_FX.2' is present. Below the diagrams is an acronym list: TIA - Transimpedance amplifier, LA - Limiting amplifier, MUX - Multiplexer.
+
+**Figure X.2 – Example of dual-rate coexistence PMD implementation with single data path**
+
+One processing method is shown in Figure X.2-a. The output signal from the TIA is transmitted to the 10G LA and 2.5G LA separately, then through two different limiting amplifiers. The outputs of the limiting amplifiers are transmitted to a high speed MUX which selects the 2.5G LA or the 10G LA input signal by means of the RATE\_SELECT signal. An additional time parameter, Multiplexer switch time  $T(sm)$ , is introduced here – it is the switching time from one input channel to the other. This switching process could cause an additional overhead to the data transmission. However, with an appropriate design of dynamic bandwidth assignment (DBA) grant, it would have only a slight impact on the upstream bandwidth.
+
+The RATE\_SELECT signal could be generated by the TWDM TC sublayer. In the upstream direction, the dual-rate OLT CT supports the coexistence of 10G ONU and 2.5G ONUs via TDMA. OLT CT arbitrates 10G ONU and 2.5G ONU data according to the DBA grant window. It can be known which time slice is allocated to the 2.5G or the 10G stream by the calculation of DBA on the TWDM TC sublayer. As a result, the switching process of the MUX can start at the laser off time in the guard time of the DBA grant window.
+
+Another processing method is shown in Figure X.2-b. The dual rate LA device is used for generating the output signal. The dual rate LA adapts the dual path amplification for the input signals at the different frequencies as follows:
+
+The dual-rate LA features a low data rate path and a high data rate path, allowing for overall transmission optimization. Data path selection is controlled by the RATE\_SELECT signal. The processing of the RATE\_SELECT signal is the same as for the design in the first example. The low data rate path further features a low pass filter that provides optimization for high frequency noise suppression, which could increase the optical signal receive sensitivity for the 10G stream.
+
+# Appendix XI
+
+## Optical parameter specification for the S/R-CP reference point
+
+(This appendix does not form an integral part of this Recommendation.)
+
+The primary method of optical parameter specification is in reference to the S/R point for channel group (S/R-CG reference point of the Figure 6-1 for the individual wavelength channels). This method is used in the PMD tables appearing in the Clause 11 of this Recommendation. An alternative informative optical parameter specification method is in reference to the S/R point for channel pair (S/R-CP reference point of the Figure 6-1). The alternative method is applicable in the situations when the primary reference point, S/R-CG, is not practical or not accessible for performing measurements or it is desirable to provide a simple sensitivity specification to an OLT transceiver vendor. The alternative method is given in this appendix.
+
+This appendix provides informative optical parameter specification of the OLT and ONU in reference to the S/R-CP point of the NG-PON2 reference logical architecture (see Figure 6-1) for the symmetric nominal line rate option (9.95328/9.95328 Gb/s in downstream/upstream), Type A optical link and N1/N2 ODN classes. For the N2 ODN class, an optical split ratio of 1:64 or higher is assumed. The optical parameter specifications in reference to the S/R-CP point for the other nominal line rate options, Type B optical link and/or other ODN classes remain for further study.
+
+The recommended values of optical power parameters consistent with the primary specifications of clause 11 and based on the industry best practices with respect to the WM loss and penalty parameters (see Table XI.1) are given in Table XI.2
+
+**Table XI.1 – WM loss and penalty parameters based on the industry best practices**
+
+| Parameter                           | Notation               | Unit | Value |     |
+|-------------------------------------|------------------------|------|-------|-----|
+|                                     |                        |      | N1    | N2  |
+| ODN Class                           |                        |      |       |     |
+| Minimum insertion loss              | $WM_{\min}$            | dB   | 1.2   | 1.2 |
+| Maximum insertion loss              | $WM_{\max}$            | dB   | 2.2   | 2.2 |
+| IBXT penalty                        | $\delta_{\text{IBXT}}$ | dB   | 0.5   | 0.3 |
+| WM inter-channel cross-talk penalty | $\delta_{\text{ICXT}}$ | dB   | 0.5   | 0.1 |
+| Downstream WM penalty               | $\delta_{\text{DS}}$   | dB   | 0.0   | 0.0 |
+
+Let  $P_{\min}$ ,  $P_{\max}$ ,  $S$  and  $L$  denote, respectively, the mean launch optical power minimum, the mean launch optical power maximum, sensitivity and overload at a respective point identified by the subscript. The optical parameters referenced to the S/R-CP point can be established using the following equations (assuming logarithmic units):
+
+$$P_{\min\text{-CP}} = P_{\min\text{-CG}} + WM_{\max} + \delta_{\text{DS}};$$
+
+$$P_{\max\text{-CP}} = P_{\max\text{-CG}} + WM_{\min};$$
+
+$$S_{\text{CP}} = S_{\text{CG}} - WM_{\max} - (\delta_{\text{IBXT}} + \delta_{\text{ICXT}});$$
+
+$$L_{\text{CP}} = L_{\text{CG}} - WM_{\min}.$$
+
+The parameters listed in Table XI.2 modify the respective optical power parameter rows in Table 11-5 and Table 11-7. The rest of the parameters of those tables remain applicable.
+
+**Table XI.2 – Optical power parameters at the S/R-CP reference point**
+
+| Source     | Item                                                                          | Notation             | Unit | Value |       |
+|------------|-------------------------------------------------------------------------------|----------------------|------|-------|-------|
+|            |                                                                               |                      |      | N1    | N2    |
+| Table 11-5 | ODN class                                                                     |                      |      |       |       |
+|            | Mean channel launch power minimum (at S/R-CP)                                 | $P_{\min\text{-CP}}$ | dBm  | +5.2  | +7.2  |
+| Table 11-7 | Mean channel launch power maximum (at S/R-CP)                                 | $P_{\max\text{-CP}}$ | dBm  | +8.2  | +10.2 |
+|            | Sensitivity (at S/R-CP), based on DD20, four wavelength, Type A link (Note 1) | $S_{\text{CP}}$      | dBm  | -29.2 | -30.6 |
+|            | Overload (at S/R-CP), Type A link                                             | $L_{\text{CP}}$      | dBm  | -6.2  | -8.2  |
+
+NOTE 1 – The sensitivity values specified at the S/R-CG point (e.g., Table 11-7) are to be measured with all 4 channels operating to produce crosstalk, but with no fiber. The sensitivity values specified here at the S/R-CP point are to be measured with no other channels operating and with no fiber.
+
+# Bibliography
+
+- [b-ITU-T G.810] Recommendation ITU-T G.810 (1996), *Definitions and terminology for synchronization networks*.
+- [b-ITU-T G.902] Recommendation ITU-T G.902 (1995), *Framework Recommendation on functional access networks (AN) – Architecture and functions, access types, management and service node aspects*.
+- [b-ITU-T G.Sup39] ITU-T G-series Recommendations – Supplement 39 (2016), *Optical system design and engineering considerations*.
+- [b-ITU-T I.112] Recommendation ITU-T I.112 (1993), *Vocabulary of terms for ISDNs*.
+- [b-MEF 6.1] Metro Ethernet Forum Technical Specification 6.1 (2008), *Ethernet Services Definitions – Phase 2*.
+- [b-IEEE 802.3] IEEE Std. 802.3-2012, *IEEE Standard for Ethernet*.
+- [b-ANSI 230-1994] ANSI INCITS 230-1994 (R1999), *Information Technology – Fibre Channel – Physical and Signaling Interface (FC-PH)*. (formerly ANSI X3.230-1994 (R1999)) (includes supplements).
+- [b-Al-Qazwini] Al-Qazwini Z., and Kim H. (2010), *Line coding to enhance the performance of 10-Gb/s CPFSK-ASK directly modulated signals*, Opt Express 18, 8360-8366.
+- [b-BBF TR-101] Broadband Forum, Technical Report TR-101 (2011), *Migration to Ethernet-Based Broadband Aggregation*, issue 2, July.
+- [b-CPRI] CPRI Specification V6.1 (2014-07-01) Common Public Radio Interface (CPRI), *Interface Specification*.
+- [b-Kim] Kim H., Han K.H., Chung Y.C. (2001), *Performance limitation of hybrid WDM systems due to stimulated Raman scattering*, Photonics Technology Letters, IEEE, vol. 13, no. 10, pp. 1118,1120, Oct. 2001.
+
+
+
+## **SERIES OF ITU-T RECOMMENDATIONS**
+
+|                 |                                                                                                                                                           |
+|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Series A        | Organization of the work of ITU-T                                                                                                                         |
+| Series D        | Tariff and accounting principles and international telecommunication/ICT economic and policy issues                                                       |
+| Series E        | Overall network operation, telephone service, service operation and human factors                                                                         |
+| Series F        | Non-telephone telecommunication services                                                                                                                  |
+| <b>Series G</b> | <b>Transmission systems and media, digital systems and networks</b>                                                                                       |
+| Series H        | Audiovisual and multimedia systems                                                                                                                        |
+| Series I        | Integrated services digital network                                                                                                                       |
+| Series J        | Cable networks and transmission of television, sound programme and other multimedia signals                                                               |
+| Series K        | Protection against interference                                                                                                                           |
+| Series L        | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant |
+| Series M        | Telecommunication management, including TMN and network maintenance                                                                                       |
+| Series N        | Maintenance: international sound programme and television transmission circuits                                                                           |
+| Series O        | Specifications of measuring equipment                                                                                                                     |
+| Series P        | Telephone transmission quality, telephone installations, local line networks                                                                              |
+| Series Q        | Switching and signalling, and associated measurements and tests                                                                                           |
+| Series R        | Telegraph transmission                                                                                                                                    |
+| Series S        | Telegraph services terminal equipment                                                                                                                     |
+| Series T        | Terminals for telematic services                                                                                                                          |
+| Series U        | Telegraph switching                                                                                                                                       |
+| Series V        | Data communication over the telephone network                                                                                                             |
+| Series X        | Data networks, open system communications and security                                                                                                    |
+| Series Y        | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities                               |
+| Series Z        | Languages and general software aspects for telecommunication systems                                                                                      |
\ No newline at end of file
diff --git a/marked/G/T-REC-G.9972-201006-I_PDF-E/raw.md b/marked/G/T-REC-G.9972-201006-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..0a3b9462015df5389f72791f762a27ce91c93bb9
--- /dev/null
+++ b/marked/G/T-REC-G.9972-201006-I_PDF-E/raw.md
@@ -0,0 +1,1327 @@
+
+
+**ITU-T**
+
+TELECOMMUNICATION  
+STANDARDIZATION SECTOR  
+OF ITU
+
+**G.9972**
+
+(06/2010)
+
+SERIES G: TRANSMISSION SYSTEMS AND MEDIA,  
+DIGITAL SYSTEMS AND NETWORKS
+
+Access networks – In premises networks
+
+# --- **Coexistence mechanism for wireline home networking transceivers**
+
+Recommendation ITU-T G.9972
+
+## ITU-T G-SERIES RECOMMENDATIONS **TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS**
+
+|                                                                                                                                              |                      |
+|----------------------------------------------------------------------------------------------------------------------------------------------|----------------------|
+| INTERNATIONAL TELEPHONE CONNECTIONS AND CIRCUITS                                                                                             | G.100–G.199          |
+| GENERAL CHARACTERISTICS COMMON TO ALL ANALOGUE CARRIER-TRANSMISSION SYSTEMS                                                                  | G.200–G.299          |
+| INDIVIDUAL CHARACTERISTICS OF INTERNATIONAL CARRIER TELEPHONE SYSTEMS ON METALLIC LINES                                                      | G.300–G.399          |
+| GENERAL CHARACTERISTICS OF INTERNATIONAL CARRIER TELEPHONE SYSTEMS ON RADIO-RELAY OR SATELLITE LINKS AND INTERCONNECTION WITH METALLIC LINES | G.400–G.449          |
+| COORDINATION OF RADIOTELEPHONY AND LINE TELEPHONY                                                                                            | G.450–G.499          |
+| TRANSMISSION MEDIA AND OPTICAL SYSTEMS CHARACTERISTICS                                                                                       | G.600–G.699          |
+| DIGITAL TERMINAL EQUIPMENTS                                                                                                                  | G.700–G.799          |
+| DIGITAL NETWORKS                                                                                                                             | G.800–G.899          |
+| DIGITAL SECTIONS AND DIGITAL LINE SYSTEM                                                                                                     | G.900–G.999          |
+| MULTIMEDIA QUALITY OF SERVICE AND PERFORMANCE – GENERIC AND USER-RELATED ASPECTS                                                             | G.1000–G.1999        |
+| TRANSMISSION MEDIA CHARACTERISTICS                                                                                                           | G.6000–G.6999        |
+| DATA OVER TRANSPORT – GENERIC ASPECTS                                                                                                        | G.7000–G.7999        |
+| PACKET OVER TRANSPORT ASPECTS                                                                                                                | G.8000–G.8999        |
+| ACCESS NETWORKS                                                                                                                              | G.9000–G.9999        |
+| <b>In premises networks</b>                                                                                                                  | <b>G.9950–G.9999</b> |
+
+*For further details, please refer to the list of ITU-T Recommendations.*
+
+## **Recommendation ITU-T G.9972**
+
+# **Coexistence mechanism for wireline home networking transceivers**
+
+## **Summary**
+
+Recommendation ITU-T G.9972 specifies a coexistence mechanism for home networking transceivers capable of operating over powerline wiring. The coexistence mechanism allows ITU-T G.996x devices to coexist with other coexisting systems, as defined in this Recommendation, operating on the same powerline wiring.
+
+## **History**
+
+| Edition | Recommendation | Approval   | Study Group |
+|---------|----------------|------------|-------------|
+| 1.0     | ITU-T G.9972   | 2010-06-11 | 15          |
+
+# FOREWORD
+
+The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis.
+
+The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics.
+
+The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1.
+
+In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC.
+
+## NOTE
+
+In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party.
+
+## INTELLECTUAL PROPERTY RIGHTS
+
+ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process.
+
+As of the date of approval of this Recommendation, ITU had received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at <http://www.itu.int/ITU-T/ipr/>.
+
+© ITU 2011
+
+All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU.
+
+## Table of Contents
+
+###### Page
+
+|      |                                                  |    |
+|------|--------------------------------------------------|----|
+| 1    | Scope .....                                      | 1  |
+| 2    | References.....                                  | 1  |
+| 3    | Definitions .....                                | 1  |
+| 4    | Abbreviations.....                               | 2  |
+| 5    | Overview .....                                   | 3  |
+| 5.1  | Inter-system protocol.....                       | 3  |
+| 5.2  | Network status .....                             | 3  |
+| 5.3  | Resource allocation .....                        | 3  |
+| 5.4  | Start-up and re-synchronization procedures.....  | 4  |
+| 6    | Coexistence signal definition.....               | 4  |
+| 6.1  | Signal generation .....                          | 5  |
+| 6.2  | Phase vectors .....                              | 8  |
+| 6.3  | Sync point.....                                  | 9  |
+| 7    | Coexistence signalling scheme .....              | 10 |
+| 7.1  | ISP window .....                                 | 10 |
+| 7.2  | ISP fields .....                                 | 11 |
+| 7.3  | Network status .....                             | 13 |
+| 8    | Coexistence resources.....                       | 14 |
+| 8.1  | Frequency domain multiplex (FDM).....            | 14 |
+| 8.2  | Time domain multiplex (TDM).....                 | 15 |
+| 8.3  | FDM/TDM modes .....                              | 16 |
+| 8.4  | Parameters .....                                 | 17 |
+| 9    | Resource allocation.....                         | 18 |
+| 9.1  | TDM resource allocation for access systems ..... | 18 |
+| 9.2  | TDM resource allocation .....                    | 19 |
+| 10   | Start-up and resynchronization procedures .....  | 19 |
+| 10.1 | Start-up procedure .....                         | 20 |
+| 10.2 | Resynchronization procedure .....                | 22 |
+| 11   | Power control procedures .....                   | 25 |
+| 12   | Time slot reuse.....                             | 25 |
+| 13   | Generic management message.....                  | 25 |
+| 13.1 | State indication messages .....                  | 25 |
+| 13.2 | Resynchronization messages .....                 | 26 |
+| 14   | Signal transmission and detection .....          | 28 |
+| 14.1 | Transmit PSD .....                               | 28 |
+| 14.2 | Signal detection .....                           | 29 |
+| 14.3 | Zero-crossing detection .....                    | 29 |
+
+|                                                                    | <b>Page</b> |
+|--------------------------------------------------------------------|-------------|
+| Annex A – ITU-T G.996x coexistence management messages.....        | 30          |
+| A.1    ITU-T G.996x coexistence management message parameters..... | 30          |
+| Bibliography.....                                                  | 35          |
+
+## Recommendation ITU-T G.9972
+
+# Coexistence mechanism for wireline home networking transceivers
+
+# 1 Scope
+
+This Recommendation specifies a coexistence mechanism for home networking transceivers capable of operating over powerline wiring. The coexistence mechanism allows ITU-T G.996x devices to coexist with other coexisting systems, as defined in this Recommendation, operating on the same powerline wiring.
+
+Specifically, this Recommendation defines:
+
+- the coexistence signal structure and characteristics;
+- the coexistence signalling scheme and timing requirements;
+- the allocation of resources to each coexisting system;
+- the start-up, synchronization and resynchronization procedures;
+- the generic messages required to be supported by each coexisting system;
+- the time slot reuse requirements;
+- the signal transmission and detection requirements.
+
+# 2 References
+
+The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation.
+
+[ITU-T G.996x] Recommendations ITU-T G.996x (in force), *Test procedures for digital subscriber line (DSL) transceivers*.
+
+[ITU-T G.9960] Recommendation ITU-T G.9960 (2010), *Unified high-speed wire-line based home networking transceivers – System architecture and physical layer specification*.
+
+# 3 Definitions
+
+This Recommendation defines the following terms:
+
+**3.1 access system:** A powerline communications system carrying high-speed digital communications on frequencies above 2 MHz over medium and low voltage electric powerlines that distribute electricity to end-user premises enabling a communication link between the power utility infrastructure and the home. The electric powerlines may be both outside and within buildings.
+
+**3.2 coexistence:** The capability that allows two or more non-interoperable systems to share the same medium, while minimizing mutual interference to each other.
+
+**3.3 coexisting system:** A powerline communications system that belongs to one of the coexisting system categories and uses ISP to coexist with other non-interoperable systems.
+
+**3.4 coexisting systems categories:** ITU-T G.996x, IHC1, IHC2 and ACC. IHC1, IHC2 and ACC are reserved by ITU-T. [ITU-T G.996x] is the family of home networking Recommendations including [ITU-T G.9960].
+
+NOTE – IHC1 and IHC2 are to be allocated to [b-IEEE 1901].
+
+**3.5 ISP field:** The region in frequency and time within which an ISP signal is transmitted.
+
+**3.6 ISP phase vector:** The sub-carriers of the ISP signal, each of which may be transmitted with either phase 0 or phase  $\pi$ . The phase vector defines which sub-carriers are transmitted with which phase. Five phase vectors are defined.
+
+**3.7 ISP sequence:** A series of consecutive ISP windows to which one or more coexisting systems are synchronized.
+
+**3.8 ISP signal:** An OFDM-based signal used by coexisting systems to indicate their status or requests to other coexisting systems. ISP signals are transmitted within ISP fields.
+
+**3.9 ISP window:** A group of two ISP fields that is contiguous in time. Consecutive ISP windows are separated by the period  $T_{\text{ISP}}$ .
+
+**3.10 master node:** A node in a coexisting system that determines the overall ISP timing, resource allocation, and start-up/resynchronization behaviour with other coexisting systems.
+
+**3.11 slave node:** Any node in a coexisting system other than the master node.
+
+**3.12 synchronization period ( $T_{\text{H}}$ ):** The period between consecutive ISP windows of the same type. Consists of several  $T_{\text{ISP}}$  periods and forms the period for an entire cycle of ISP signalling.
+
+**3.13 synchronization point (sync point):** A point in time located at multiples of 60 degrees from a zero-crossing point on an AC mains. The first ISP field begins at a set offset (ISP\_OFFSET) from a sync point.
+
+**3.14 TDM unit (TDMU):** A sub-division of the time between consecutive ISP windows. A TDMU is further divided into TDM slots.
+
+**3.15 TDM slot (TDMs):** The smallest amount of time that may be allocated to a coexisting system in TDM mode. Particular TDMs are allocated to particular systems depending upon the current network status.
+
+# 4 Abbreviations
+
+This Recommendation uses the following abbreviations:
+
+|      |                                |
+|------|--------------------------------|
+| ACC  | Access                         |
+| AWGN | Additive White Gaussian Noise  |
+| EMI  | Electromagnetic Interference   |
+| FB   | Full Bandwidth                 |
+| FDM  | Frequency Domain Multiplex     |
+| IFFT | Inverse Fast Fourier Transform |
+| IH   | In-Home                        |
+| IHC1 | In-Home Category 1             |
+| IHC2 | In-Home Category 2             |
+| IH-G | ITU-T G.996x                   |
+| ISP  | Inter-System Protocol          |
+
+|      |                                            |
+|------|--------------------------------------------|
+| OFDM | Orthogonal Frequency Division Multiplexing |
+| PB   | Partial Bandwidth                          |
+| TDM  | Time Domain Multiplex                      |
+| TDMA | Time Division Multiple Access              |
+
+# 5 Overview
+
+Inter-system protocol (ISP) allows for the powerline medium to be shared between coexisting systems in the time domain, called time domain multiplex (TDM), the frequency domain, called frequency domain multiplex (FDM), or both. ISP supports coexistence between up to four non-interoperable coexisting systems. This Recommendation assumes that there is only one access system operating over the distribution lines that provide power to a given customer premises.
+
+The frequency range used by ISP signalling ranges from 2 MHz to 50 MHz.
+
+Sharing of the powerline medium between coexisting systems is determined by the following:
+
+- number of coexisting systems on the powerline;
+- type of coexisting system;
+- access system capacity request.
+
+An overview of the ISP is provided in the next clause, followed by clauses describing the details of each component of the protocol.
+
+## 5.1 Inter-system protocol
+
+### 5.1.1 Coexistence signalling
+
+Coexistence signalling is carried out by the use of periodically repeating ISP windows that are used to convey information on coexisting system presence, resource requirements and resynchronization request. Each coexisting system category is allocated a particular ISP window in a round robin fashion.
+
+## 5.2 Network status
+
+By monitoring the signals transmitted within the ISP windows allocated to other coexisting systems, a coexisting system is able to detect the number and type of other coexisting systems present on the line and the resource requirements of the access system (i.e., partial/full bandwidth).
+
+By monitoring the signals within its own ISP window, a coexisting system is able to detect a resynchronization request from one of the other coexisting systems.
+
+This set of instantaneous information is termed the network status. Network status is used to determine the allocation of resources to each coexisting system.
+
+## 5.3 Resource allocation
+
+### 5.3.1 Frequency domain multiplex (FDM)
+
+Within ISP, FDM may only be invoked by an access system. The overall FDM scheme consists of two frequency bands. The upper band is shared using TDM by in-home systems, the lower band reserved for access systems. One of two FDM band separation frequencies (10 MHz or 14 MHz) is chosen by the access system.
+
+### 5.3.2 Time domain multiplex (TDM)
+
+ISP allows TDM to be implemented between coexisting in-home systems or between coexisting in-home systems and an access system. The allocation of resources in the time domain is described in clause 9.
+
+The period between each ISP window is divided into smaller units and sub-units that are used as the basis for TDM resource allocation.
+
+## 5.4 Start-up and re-synchronization procedures
+
+In order to allow coexisting systems to synchronize to the appropriate ISP sequence and hence to effectively coexist, the ISP defines:
+
+- procedures for system start-up;
+- triggers and procedures for re-synchronizing to a different ISP sequence.
+
+# 6 Coexistence signal definition
+
+The structure of the ISP signal shall be as follows:
+
+- The ISP signal consists of 16 consecutive OFDM symbols.
+- Each OFDM symbol is formed using a 512-point inverse fast fourier transform (IFFT) with each sub-carrier having a phase shift defined in clause 6.2.
+- The ISP time domain signal is then multiplied by a window function  $W(n)$  to reduce the out-of-band energy in order to be compliant with the transmit spectrum mask. The window function  $W(n)$  is vendor proprietary.
+
+The ISP signal is depicted in Figure 6-1.
+
+![Figure 6-1: Timing of the ISP signal. The diagram shows a signal envelope with a windowing duration Tw at the beginning and end. The central part contains 16 consecutive OFDM symbols, with a duration Tss. The total duration is Ttotal. The duration of a single OFDM symbol is Ts. The diagram is labeled G.9972(10)_F6-1.](58de972a8c79c238b69cbeeafcc8d5fb_img.jpg)
+
+The diagram illustrates the timing of the ISP signal. It shows a signal envelope with a windowing duration  $T_w$  at the beginning and end. The central part contains 16 consecutive OFDM symbols, with a duration  $T_{ss}$ . The total duration is  $T_{total}$ . The duration of a single OFDM symbol is  $T_s$ . The diagram is labeled G.9972(10)\_F6-1.
+
+Figure 6-1: Timing of the ISP signal. The diagram shows a signal envelope with a windowing duration Tw at the beginning and end. The central part contains 16 consecutive OFDM symbols, with a duration Tss. The total duration is Ttotal. The duration of a single OFDM symbol is Ts. The diagram is labeled G.9972(10)\_F6-1.
+
+Figure 6-1 – Timing of the ISP signal
+
+The parameters that define the signal are shown in Table 6-1.
+
+Table 6-1 – ISP signal parameters
+
+| Symbol      | Description           | Time samples (assuming a 100 MHz sampling rate) | Time ( $\mu\text{s}$ )      |
+|-------------|-----------------------|-------------------------------------------------|-----------------------------|
+| $T_s$       | OFDM symbol duration  | 512                                             | 5.12                        |
+| $T_{ss}$    | OFDM signals duration | $T_{total} - 2 * T_w$                           | $T_{total} - 2 * T_w$       |
+| $T_w$       | Windowing duration    | Less than or equal to 1024                      | Less than or equal to 10.24 |
+| $T_{total}$ | ISP signal duration   | 8192                                            | 81.92                       |
+
+## 6.1 Signal generation
+
+The ISP signal,  $S_I(n)$ , is defined as time-domain samples assuming a 100 MHz sampling rate:
+
+$$S_I(n) = N_c \cdot W(n) \cdot \sum_{C_a} \cos\left(\frac{2 \cdot \pi \cdot C_a \cdot n}{512} + \phi(C_a)\right)$$
+
+where:
+
+$$0 \leq n < 8192$$
+
+$N_c$  is a normalization factor
+
+$W(n)$  is a windowing function
+
+$C_a$  is the sub-carrier index
+
+$\phi(C_a)$  is the phase vector
+
+The choice of windowing function,  $W(n)$ , is implementation dependent.  $W(n)$  shall be chosen to meet the following requirements:
+
+$$W(n) = 1 \text{ for } 1024 \leq n \leq 7167$$
+
+$$0 \leq W(n) \leq 1 \text{ for } 0 \leq n \leq 1023 \text{ and } 7168 \leq n \leq 8191$$
+
+$W(n)$  shall enable the ISP signals to comply with the transmit spectrum mask.
+
+The ISP signal is composed by cascading 16 identical OFDM symbols with windowing applied at the beginning and at the end. A single OFDM symbol,  $S_S(n)$  within an ISP signal is defined below as time-domain samples assuming a 100 MHz sampling rate:
+
+$$S_S(n) = N_c \sum_{C_a} \cos\left(\frac{2 \cdot \pi \cdot C_a \cdot n}{512} + \phi(C_a)\right)$$
+
+where:
+
+$$0 \leq n < 512.$$
+
+The sub-carrier frequencies used in the above equation are shown in Table 6-3. The sub-carrier frequency values given in Table 6-3 are normative, according to the clock tolerance specified in clause 14, signal detection and transmission. The transmit PSD requirements are specified in clause 14.
+
+The lower limit of the frequency range of the ISP signal shall be fixed at 2.1484375 MHz (i.e., sub-carrier #11).
+
+The maximum value of the upper limit of the frequency range of the ISP signal shall be 49.8046875 MHz (i.e., sub-carrier #255).
+
+For those coexisting systems with maximum operating frequency at 30 MHz and above, the value of the upper limit of the frequency range of the ISP signal shall be at least 29.8828125 MHz (i.e., sub-carrier #153).
+
+For those coexisting systems with maximum operating frequency below 30 MHz, the value of the upper limit of the frequency range of the ISP signal shall be the closest value that is equal to or lower than the maximum operating frequency of the coexisting system.
+
+**Table 6-2 – Upper limit of the ISP signal frequency range as a function of maximum operating frequency**
+
+| Upper value of operating frequency range ( <i>f</i> )/MHz | Lower value of ISP signal sub-carrier index (Note) | Upper value of ISP signal sub-carrier index                                               | Limit of upper value of ISP signal sub-carrier index |
+|-----------------------------------------------------------|----------------------------------------------------|-------------------------------------------------------------------------------------------|------------------------------------------------------|
+| > 50                                                      | 11                                                 | $\geq 153$ and $\leq 255$                                                                 | 255                                                  |
+| $30 \leq f \leq 50$                                       | 11                                                 | $\geq 153$ and $\leq 255$                                                                 | 255                                                  |
+| $2.1484375 \leq f < 30$                                   | 11                                                 | <i>C<sub>a</sub></i> value closest and less than upper value of operating frequency range | 255                                                  |
+
+NOTE – IH systems operating in FDM mode may set the lower value of ISP signal sub-carrier index to the *C<sub>a</sub>* value closest and greater than the lower value of the operating frequency range. In this case, ACC may not be able to detect the "interference threshold exceeded" signal transmitted by the IH system.
+
+It must be noted that the frequency of each sub-carrier corresponds to the following expression:
+
+$$f_{C_a} = C_a \frac{f_s}{N_{IFFT}} = C_a \frac{100}{512} \text{ MHz} = C_a \cdot 195.3125 \text{ kHz}$$
+
+**Table 6-3 – ISP signal sub-carrier frequencies**
+
+| <i>C<sub>a</sub></i> | Freq [kHz] | <i>C<sub>a</sub></i> | Freq [kHz] | <i>C<sub>a</sub></i> | Freq [kHz] | <i>C<sub>a</sub></i> | Freq [kHz] |
+|----------------------|------------|----------------------|------------|----------------------|------------|----------------------|------------|
+| 0                    | 0.0000     | 64                   | 12500.0000 | 128                  | 25000.0000 | 192                  | 37500.0000 |
+| 1                    | 195.3125   | 65                   | 12695.3125 | 129                  | 25195.3125 | 193                  | 37695.3125 |
+| 2                    | 390.6250   | 66                   | 12890.6250 | 130                  | 25390.6250 | 194                  | 37890.6250 |
+| 3                    | 585.9375   | 67                   | 13085.9375 | 131                  | 25585.9375 | 195                  | 38085.9375 |
+| 4                    | 781.2500   | 68                   | 13281.2500 | 132                  | 25781.2500 | 196                  | 38281.2500 |
+| 5                    | 976.5625   | 69                   | 13476.5625 | 133                  | 25976.5625 | 197                  | 38476.5625 |
+| 6                    | 1171.8750  | 70                   | 13671.8750 | 134                  | 26171.8750 | 198                  | 38671.8750 |
+| 7                    | 1367.1875  | 71                   | 13867.1875 | 135                  | 26367.1875 | 199                  | 38867.1875 |
+| 8                    | 1562.5000  | 72                   | 14062.5000 | 136                  | 26562.5000 | 200                  | 39062.5000 |
+| 9                    | 1757.8125  | 73                   | 14257.8125 | 137                  | 26757.8125 | 201                  | 39257.8125 |
+| 10                   | 1953.1250  | 74                   | 14453.1250 | 138                  | 26953.1250 | 202                  | 39453.1250 |
+| 11                   | 2148.4375  | 75                   | 14648.4375 | 139                  | 27148.4375 | 203                  | 39648.4375 |
+| 12                   | 2343.7500  | 76                   | 14843.7500 | 140                  | 27343.7500 | 204                  | 39843.7500 |
+| 13                   | 2539.0625  | 77                   | 15039.0625 | 141                  | 27539.0625 | 205                  | 40039.0625 |
+| 14                   | 2734.3750  | 78                   | 15234.3750 | 142                  | 27734.3750 | 206                  | 40234.3750 |
+| 15                   | 2929.6875  | 79                   | 15429.6875 | 143                  | 27929.6875 | 207                  | 40429.6875 |
+| 16                   | 3125.0000  | 80                   | 15625.0000 | 144                  | 28125.0000 | 208                  | 40625.0000 |
+| 17                   | 3320.3125  | 81                   | 15820.3125 | 145                  | 28320.3125 | 209                  | 40820.3125 |
+| 18                   | 3515.6250  | 82                   | 16015.6250 | 146                  | 28515.6250 | 210                  | 41015.6250 |
+| 19                   | 3710.9375  | 83                   | 16210.9375 | 147                  | 28710.9375 | 211                  | 41210.9375 |
+| 20                   | 3906.2500  | 84                   | 16406.2500 | 148                  | 28906.2500 | 212                  | 41406.2500 |
+
+**Table 6-3 – ISP signal sub-carrier frequencies**
+
+| <b>C<sub>a</sub></b> | <b>Freq [kHz]</b> | <b>C<sub>a</sub></b> | <b>Freq [kHz]</b> | <b>C<sub>a</sub></b> | <b>Freq [kHz]</b> | <b>C<sub>a</sub></b> | <b>Freq [kHz]</b> |
+|----------------------|-------------------|----------------------|-------------------|----------------------|-------------------|----------------------|-------------------|
+| 21                   | 4101.5625         | 85                   | 16601.5625        | 149                  | 29101.5625        | 213                  | 41601.5625        |
+| 22                   | 4296.8750         | 86                   | 16796.8750        | 150                  | 29296.8750        | 214                  | 41796.8750        |
+| 23                   | 4492.1875         | 87                   | 16992.1875        | 151                  | 29492.1875        | 215                  | 41992.1875        |
+| 24                   | 4687.5000         | 88                   | 17187.5000        | 152                  | 29687.5000        | 216                  | 42187.5000        |
+| 25                   | 4882.8125         | 89                   | 17382.8125        | 153                  | 29882.8125        | 217                  | 42382.8125        |
+| 26                   | 5078.1250         | 90                   | 17578.1250        | 154                  | 30078.1250        | 218                  | 42578.1250        |
+| 27                   | 5273.4375         | 91                   | 17773.4375        | 155                  | 30273.4375        | 219                  | 42773.4375        |
+| 28                   | 5468.7500         | 92                   | 17968.7500        | 156                  | 30468.7500        | 220                  | 42968.7500        |
+| 29                   | 5664.0625         | 93                   | 18164.0625        | 157                  | 30664.0625        | 221                  | 43164.0625        |
+| 30                   | 5859.3750         | 94                   | 18359.3750        | 158                  | 30859.3750        | 222                  | 43359.3750        |
+| 31                   | 6054.6875         | 95                   | 18554.6875        | 159                  | 31054.6875        | 223                  | 43554.6875        |
+| 32                   | 6250.0000         | 96                   | 18750.0000        | 160                  | 31250.0000        | 224                  | 43750.0000        |
+| 33                   | 6445.3125         | 97                   | 18945.3125        | 161                  | 31445.3125        | 225                  | 43945.3125        |
+| 34                   | 6640.6250         | 98                   | 19140.6250        | 162                  | 31640.6250        | 226                  | 44140.6250        |
+| 35                   | 6835.9375         | 99                   | 19335.9375        | 163                  | 31835.9375        | 227                  | 44335.9375        |
+| 36                   | 7031.2500         | 100                  | 19531.2500        | 164                  | 32031.2500        | 228                  | 44531.2500        |
+| 37                   | 7226.5625         | 101                  | 19726.5625        | 165                  | 32226.5625        | 229                  | 44726.5625        |
+| 38                   | 7421.8750         | 102                  | 19921.8750        | 166                  | 32421.8750        | 230                  | 44921.8750        |
+| 39                   | 7617.1875         | 103                  | 20117.1875        | 167                  | 32617.1875        | 231                  | 45117.1875        |
+| 40                   | 7812.5000         | 104                  | 20312.5000        | 168                  | 32812.5000        | 232                  | 45312.5000        |
+| 41                   | 8007.8125         | 105                  | 20507.8125        | 169                  | 33007.8125        | 233                  | 45507.8125        |
+| 42                   | 8203.1250         | 106                  | 20703.1250        | 170                  | 33203.1250        | 234                  | 45703.1250        |
+| 43                   | 8398.4375         | 107                  | 20898.4375        | 171                  | 33398.4375        | 235                  | 45898.4375        |
+| 44                   | 8593.7500         | 108                  | 21093.7500        | 172                  | 33593.7500        | 236                  | 46093.7500        |
+| 45                   | 8789.0625         | 109                  | 21289.0625        | 173                  | 33789.0625        | 237                  | 46289.0625        |
+| 46                   | 8984.3750         | 110                  | 21484.3750        | 174                  | 33984.3750        | 238                  | 46484.3750        |
+| 47                   | 9179.6875         | 111                  | 21679.6875        | 175                  | 34179.6875        | 239                  | 46679.6875        |
+| 48                   | 9375.0000         | 112                  | 21875.0000        | 176                  | 34375.0000        | 240                  | 46875.0000        |
+| 49                   | 9570.3125         | 113                  | 22070.3125        | 177                  | 34570.3125        | 241                  | 47070.3125        |
+| 50                   | 9765.6250         | 114                  | 22265.6250        | 178                  | 34765.6250        | 242                  | 47265.6250        |
+| 51                   | 9960.9375         | 115                  | 22460.9375        | 179                  | 34960.9375        | 243                  | 47460.9375        |
+| 52                   | 10156.2500        | 116                  | 22656.2500        | 180                  | 35156.2500        | 244                  | 47656.2500        |
+| 53                   | 10351.5625        | 117                  | 22851.5625        | 181                  | 35351.5625        | 245                  | 47851.5625        |
+| 54                   | 10546.8750        | 118                  | 23046.8750        | 182                  | 35546.8750        | 246                  | 48046.8750        |
+| 55                   | 10742.1875        | 119                  | 23242.1875        | 183                  | 35742.1875        | 247                  | 48242.1875        |
+| 56                   | 10937.5000        | 120                  | 23437.5000        | 184                  | 35937.5000        | 248                  | 48437.5000        |
+| 57                   | 11132.8125        | 121                  | 23632.8125        | 185                  | 36132.8125        | 249                  | 48632.8125        |
+| 58                   | 11328.1250        | 122                  | 23828.1250        | 186                  | 36328.1250        | 250                  | 48828.1250        |
+
+**Table 6-3 – ISP signal sub-carrier frequencies**
+
+| $C_a$ | Freq [kHz] | $C_a$ | Freq [kHz] | $C_a$ | Freq [kHz] | $C_a$ | Freq [kHz] |
+|-------|------------|-------|------------|-------|------------|-------|------------|
+| 59    | 11523.4375 | 123   | 24023.4375 | 187   | 36523.4375 | 251   | 49023.4375 |
+| 60    | 11718.7500 | 124   | 24218.7500 | 188   | 36718.7500 | 252   | 49218.7500 |
+| 61    | 11914.0625 | 125   | 24414.0625 | 189   | 36914.0625 | 253   | 49414.0625 |
+| 62    | 12109.3750 | 126   | 24609.3750 | 190   | 37109.3750 | 254   | 49609.3750 |
+| 63    | 12304.6875 | 127   | 24804.6875 | 191   | 37304.6875 | 255   | 49804.6875 |
+
+## 6.2 Phase vectors
+
+The ISP protocol establishes the necessity for five different signal phases, all of them based on the previously defined OFDM symbol but using different phases at each sub-carrier.
+
+Detailed definitions of each phase vector are shown in Tables 6-4 and 6-5. "Start No." in Table 6-5 shows how the original phase vector shown in the reference Table 6-4 is shifted for the corresponding phase vector. Namely, if the "Start No." is  $m$ , the phase of  $i$ th sub-carrier is equal to the phase reference whose sub-carrier index is  $(i+m) \bmod 256$ .
+
+**Table 6-4 – Phase vector reference**
+
+| $C_a$ | $\phi(C_a)$ | $C_a$ | $\phi(C_a)$ | $C_a$ | $\phi(C_a)$ | $C_a$ | $\phi(C_a)$ | $C_a$ | $\phi(C_a)$ | $C_a$ | $\phi(C_a)$ | $C_a$ | $\phi(C_a)$ | $C_a$ | $\phi(C_a)$ |
+|-------|-------------|-------|-------------|-------|-------------|-------|-------------|-------|-------------|-------|-------------|-------|-------------|-------|-------------|
+| 0     | $\pi$       | 32    | 0           | 64    | 0           | 96    | 0           | 128   | 0           | 160   | 0           | 192   | 0           | 224   | $\pi$       |
+| 1     | 0           | 33    | 0           | 65    | 0           | 97    | $\pi$       | 129   | 0           | 161   | 0           | 193   | 0           | 225   | $\pi$       |
+| 2     | 0           | 34    | 0           | 66    | 0           | 98    | $\pi$       | 130   | 0           | 162   | 0           | 194   | $\pi$       | 226   | $\pi$       |
+| 3     | 0           | 35    | 0           | 67    | $\pi$       | 99    | $\pi$       | 131   | 0           | 163   | 0           | 195   | 0           | 227   | $\pi$       |
+| 4     | 0           | 36    | 0           | 68    | 0           | 100   | $\pi$       | 132   | 0           | 164   | $\pi$       | 196   | $\pi$       | 228   | $\pi$       |
+| 5     | 0           | 37    | $\pi$       | 69    | $\pi$       | 101   | $\pi$       | 133   | 0           | 165   | $\pi$       | 197   | 0           | 229   | $\pi$       |
+| 6     | 0           | 38    | $\pi$       | 70    | 0           | 102   | $\pi$       | 134   | $\pi$       | 166   | 0           | 198   | $\pi$       | 230   | $\pi$       |
+| 7     | $\pi$       | 39    | 0           | 71    | $\pi$       | 103   | $\pi$       | 135   | 0           | 167   | 0           | 199   | 0           | 231   | 0           |
+| 8     | 0           | 40    | 0           | 72    | 0           | 104   | 0           | 136   | 0           | 168   | $\pi$       | 200   | $\pi$       | 232   | 0           |
+| 9     | 0           | 41    | $\pi$       | 73    | $\pi$       | 105   | 0           | 137   | 0           | 169   | $\pi$       | 201   | $\pi$       | 233   | 0           |
+| 10    | 0           | 42    | $\pi$       | 74    | $\pi$       | 106   | 0           | 138   | $\pi$       | 170   | 0           | 202   | $\pi$       | 234   | 0           |
+| 11    | $\pi$       | 43    | 0           | 75    | $\pi$       | 107   | 0           | 139   | 0           | 171   | $\pi$       | 203   | $\pi$       | 235   | $\pi$       |
+| 12    | 0           | 44    | $\pi$       | 76    | $\pi$       | 108   | $\pi$       | 140   | 0           | 172   | 0           | 204   | $\pi$       | 236   | $\pi$       |
+| 13    | 0           | 45    | 0           | 77    | $\pi$       | 109   | $\pi$       | 141   | $\pi$       | 173   | $\pi$       | 205   | 0           | 237   | $\pi$       |
+| 14    | $\pi$       | 46    | $\pi$       | 78    | 0           | 110   | $\pi$       | 142   | $\pi$       | 174   | 0           | 206   | $\pi$       | 238   | 0           |
+| 15    | $\pi$       | 47    | 0           | 79    | $\pi$       | 111   | 0           | 143   | 0           | 175   | 0           | 207   | 0           | 239   | $\pi$       |
+| 16    | 0           | 48    | 0           | 80    | 0           | 112   | $\pi$       | 144   | 0           | 176   | $\pi$       | 208   | 0           | 240   | $\pi$       |
+| 17    | 0           | 49    | $\pi$       | 81    | 0           | 113   | $\pi$       | 145   | 0           | 177   | $\pi$       | 209   | $\pi$       | 241   | $\pi$       |
+| 18    | 0           | 50    | $\pi$       | 82    | $\pi$       | 114   | $\pi$       | 146   | $\pi$       | 178   | $\pi$       | 210   | 0           | 242   | $\pi$       |
+| 19    | $\pi$       | 51    | $\pi$       | 83    | 0           | 115   | $\pi$       | 147   | 0           | 179   | 0           | 211   | $\pi$       | 243   | 0           |
+| 20    | 0           | 52    | 0           | 84    | $\pi$       | 116   | 0           | 148   | $\pi$       | 180   | 0           | 212   | 0           | 244   | 0           |
+| 21    | $\pi$       | 53    | 0           | 85    | 0           | 117   | 0           | 149   | $\pi$       | 181   | $\pi$       | 213   | 0           | 245   | $\pi$       |
+
+**Table 6-4 – Phase vector reference**
+
+| $C_a$ | $\emptyset(C_a)$ | $C_a$ | $\emptyset(C_a)$ | $C_a$ | $\emptyset(C_a)$ | $C_a$ | $\emptyset(C_a)$ | $C_a$ | $\emptyset(C_a)$ | $C_a$ | $\emptyset(C_a)$ | $C_a$ | $\emptyset(C_a)$ | $C_a$ | $\emptyset(C_a)$ |
+|-------|------------------|-------|------------------|-------|------------------|-------|------------------|-------|------------------|-------|------------------|-------|------------------|-------|------------------|
+| 22    | $\pi$            | 54    | $\pi$            | 86    | 0                | 118   | $\pi$            | 150   | $\pi$            | 182   | $\pi$            | 214   | 0                | 246   | 0                |
+| 23    | $\pi$            | 55    | $\pi$            | 87    | 0                | 119   | 0                | 151   | 0                | 183   | $\pi$            | 215   | $\pi$            | 247   | $\pi$            |
+| 24    | 0                | 56    | $\pi$            | 88    | $\pi$            | 120   | $\pi$            | 152   | $\pi$            | 184   | $\pi$            | 216   | $\pi$            | 248   | $\pi$            |
+| 25    | $\pi$            | 57    | $\pi$            | 89    | $\pi$            | 121   | $\pi$            | 153   | 0                | 185   | 0                | 217   | 0                | 249   | 0                |
+| 26    | 0                | 58    | 0                | 90    | 0                | 122   | 0                | 154   | $\pi$            | 186   | $\pi$            | 218   | $\pi$            | 250   | 0                |
+| 27    | $\pi$            | 59    | $\pi$            | 91    | $\pi$            | 123   | 0                | 155   | $\pi$            | 187   | $\pi$            | 219   | $\pi$            | 251   | $\pi$            |
+| 28    | $\pi$            | 60    | $\pi$            | 92    | $\pi$            | 124   | $\pi$            | 156   | 0                | 188   | 0                | 220   | $\pi$            | 252   | 0                |
+| 29    | 0                | 61    | 0                | 93    | $\pi$            | 125   | 0                | 157   | $\pi$            | 189   | $\pi$            | 221   | 0                | 253   | 0                |
+| 30    | $\pi$            | 62    | $\pi$            | 94    | 0                | 126   | 0                | 158   | $\pi$            | 190   | 0                | 222   | 0                | 254   | 0                |
+| 31    | $\pi$            | 63    | 0                | 95    | 0                | 127   | $\pi$            | 159   | 0                | 191   | 0                | 223   | 0                | 255   | 0                |
+
+**Table 6-5 – Phase vector start numbers**
+
+| Phase vector | Start No. | Use                   |
+|--------------|-----------|-----------------------|
+| Phase 1      | 1         | ACC                   |
+| Phase 2      | 2         | IHC1, resync          |
+| Phase 3      | 14        | IHC2, resync          |
+| Phase 4      | 42        | ACC, FDM interference |
+| Phase 5      | 58        | IH-G, resync          |
+
+## 6.3 Sync point
+
+A sync point is defined as a time located at 0 degree, 60 degrees, 120 degrees, 180 degrees, 240 degrees or 300 degrees relative to a zero-cross point of the AC mains. Requirements for zero-crossing detection are specified in clause 14.3. Sync points for single-phase AC mains and three-phase AC mains are shown in Figures 6-2 and 6-3, respectively. The interval between consecutive sync points is given by  $T_0$ . The first ISP field begins at ISP\_OFFSET time after a sync point.
+
+![Figure 6-2: A sinusoidal AC waveform plotted against time. The horizontal axis is labeled 'time' and has tick marks at 0, 60, 120, 180, 240, and 300 degrees. Blue triangles, labeled 'Sync points', are positioned at the zero-crossings of the waveform, corresponding to the specified angles. The label 'G.9972(10)_F6-2' is in the bottom right corner.](239211fa511b4ffa685b54b5132ec927_img.jpg)
+
+Figure 6-2: A sinusoidal AC waveform plotted against time. The horizontal axis is labeled 'time' and has tick marks at 0, 60, 120, 180, 240, and 300 degrees. Blue triangles, labeled 'Sync points', are positioned at the zero-crossings of the waveform, corresponding to the specified angles. The label 'G.9972(10)\_F6-2' is in the bottom right corner.
+
+**Figure 6-2 – Sync points (single-phase AC mains)**
+
+![Figure 6-3: Sync points (three-phase AC mains). The diagram shows three overlapping sine waves representing the first, second, and third phases of AC mains. The horizontal axis is labeled 'time'. Vertical dashed lines indicate 'Sync points' marked by blue triangles at the bottom. A legend at the bottom left identifies the phases: First phase (orange), Second phase (green), and Third phase (blue). The diagram is labeled G.9972(10)_F6-3.](ad29805cd4f64ad2828e14feb66de664_img.jpg)
+
+Figure 6-3: Sync points (three-phase AC mains). The diagram shows three overlapping sine waves representing the first, second, and third phases of AC mains. The horizontal axis is labeled 'time'. Vertical dashed lines indicate 'Sync points' marked by blue triangles at the bottom. A legend at the bottom left identifies the phases: First phase (orange), Second phase (green), and Third phase (blue). The diagram is labeled G.9972(10)\_F6-3.
+
+**Figure 6-3 – Sync points (three-phase AC mains)**
+
+# 7 Coexistence signalling scheme
+
+Each ISP window consists of two ISP fields. A coexisting system may transmit ISP signals within both fields of its allocated window, may transmit ISP signals within the second field of other coexisting systems' allocated windows, monitors the signals within the second field of its allocated window, and monitors the signals within the first field of other coexisting systems' allocated windows. Additionally, an access system monitors the signals within the second field of other coexisting systems' allocated windows. Per each ISP field, a node may be either transmitting ISP signals or monitoring ISP signals transmitted but not both.
+
+The ISP signal may be transmitted using one of a range of designated phase vectors. This allows information to be conveyed by a given ISP field.
+
+## 7.1 ISP window
+
+The ISP window is a region of time used by coexisting systems exclusively for transmitting/detecting ISP signals. The ISP window shall be allotted periodically every  $T_{ISP}$ , a multiple of AC\_CYCLE at a fixed offset,  $ISP\_OFFSET$ , from a sync point. The period formed by four consecutive  $T_{ISP}$  is given by  $T_H$ . Synchronization of the coexisting systems to a common sync point is described in clause 10. Each ISP window consists of two ISP fields. The ISP window and ISP fields are shown in Figure 7-1.
+
+![Figure 7-1: ISP time window and ISP fields concept. The diagram shows a periodic signal with a blue sine wave and red rectangular pulses. The period between pulses is labeled T_ISP. The first pulse is offset from a reference point by ISP_OFFSET. A callout box shows a single pulse divided into 'ISP field 1' and 'ISP field 2', with a double-headed arrow below it labeled 'ISP window'. The diagram is labeled G.9972(10)_F7-1.](a430996a9e8993deb0c6b25da234744b_img.jpg)
+
+Figure 7-1: ISP time window and ISP fields concept. The diagram shows a periodic signal with a blue sine wave and red rectangular pulses. The period between pulses is labeled T\_ISP. The first pulse is offset from a reference point by ISP\_OFFSET. A callout box shows a single pulse divided into 'ISP field 1' and 'ISP field 2', with a double-headed arrow below it labeled 'ISP window'. The diagram is labeled G.9972(10)\_F7-1.
+
+**Figure 7-1 – ISP time window and ISP fields concept**
+
+Each coexisting system is allocated a particular ISP window. ACC shall use an ISP window, IHC1 shall use the following ISP window, IHC2 shall use the next ISP window, and ITU-T G.996x shall use the next ISP window, as shown in Figure 7-2.
+
+![Figure 7-2: Periodicity of ISP windows. A timeline showing eight periodic windows labeled ACC (blue), IHC1 (black), IHC2 (red), and IH-G (green) at time intervals 0, 1, 2, 3, 4, 5, 6, and 7. The x-axis is labeled 'Time' and 'G.9972(10)_F7-2 (multiples of T_ISP)'.](1d529a819ad929684331c55eed6673bb_img.jpg)
+
+Figure 7-2 illustrates the periodic allocation of ISP windows. The sequence repeats every 4  $T_{ISP}$  intervals. The allocation is as follows:
+
+| Time Index (multiples of $T_{ISP}$ ) | System Category | Color Code |
+|--------------------------------------|-----------------|------------|
+| 0                                    | ACC             | Blue       |
+| 1                                    | IHC1            | Black      |
+| 2                                    | IHC2            | Orange/Red |
+| 3                                    | IH-G            | Green      |
+| 4                                    | ACC             | Blue       |
+| 5                                    | IHC1            | Black      |
+| 6                                    | IHC2            | Orange/Red |
+| 7                                    | IH-G            | Green      |
+
+Figure 7-2: Periodicity of ISP windows. A timeline showing eight periodic windows labeled ACC (blue), IHC1 (black), IHC2 (red), and IH-G (green) at time intervals 0, 1, 2, 3, 4, 5, 6, and 7. The x-axis is labeled 'Time' and 'G.9972(10)\_F7-2 (multiples of T\_ISP)'.
+
+**Figure 7-2 – Periodicity of ISP windows**
+
+All devices that belong to the same system shall transmit ISP signals in the ISP window allocated to their system with a periodicity of  $4 \cdot T_{ISP}$ , with the exceptions specified in clause 11.
+
+Every device shall monitor the remaining ISP windows in order to assess the network status, with the exceptions specified in clause 11.
+
+NOTE – It is recommended that devices occasionally scan for ISP signals in sync points outside the known ISP windows, in order to detect the presence of other, unsynchronized, systems. The frequency of this scan is vendor discretionary.
+
+## 7.2 ISP fields
+
+The ISP window contains two ISP fields. The devices of a coexisting system transmit ISP signals within these fields. The signals within each field are transmitted with a defined phase in order to convey a particular status or request. The combination of system category, field, and signal phase contributes to the network status.
+
+The ISP can be applied to the case of an access system coexisting with an ITU-T G.996x system and two mutually non-interoperable IHC1 and IHC2 systems. This most comprehensive case is described here.
+
+The ISP window occurs at the beginning of TDMU #0, TDMU#3, TDMU#6 and TDMU#9, with a periodicity  $T_{ISP}$  equal to three TDMUs, as shown in Figure 7-3.
+
+![Figure 7-3: ISP fields. A detailed diagram showing the structure of ISP windows for ACC, IHC1, IHC2, and IH-G systems. It labels fields like ACCF1, ACCF2, IIF1, IIF2, IGF1, IGF2, I2F1, and I2F2. It also shows periodicity markers for T_ISP = 3 * TDMU and 4 * 3 * TDMU. The x-axis is labeled 'G.9972(10)_F7-3'.](29f586959675cafdf81cf934954908eb_img.jpg)
+
+Figure 7-3 details the specific fields within each ISP window. Solid boxes indicate mandatory fields, while dashed boxes indicate optional fields.
+
+| System Category | Field 1 (Solid)                          | Field 2 (Dashed)                        | Phases       |
+|-----------------|------------------------------------------|-----------------------------------------|--------------|
+| ACC             | Access presence/mode (ACCF1)             | Access resource requirement (ACCF2)     | P1 or P4     |
+| IHC1            | In-home category 1 presence (Field I1F1) | In-home category 1 resynch (Field I1F2) | P2, P5 or P4 |
+| IHC2            | In-home category 2 presence (Field I2F1) | In-home category 2 resynch (Field I2F2) | P3, P2 or P4 |
+| IH-G            | ITU-T G.996x presence (Field IGF1)       | ITU-T G.996x resynch (Field IGF2)       | P5, P3 or P4 |
+
+Figure 7-3: ISP fields. A detailed diagram showing the structure of ISP windows for ACC, IHC1, IHC2, and IH-G systems. It labels fields like ACCF1, ACCF2, IIF1, IIF2, IGF1, IGF2, I2F1, and I2F2. It also shows periodicity markers for T\_ISP = 3 \* TDMU and 4 \* 3 \* TDMU. The x-axis is labeled 'G.9972(10)\_F7-3'.
+
+**Figure 7-3 – ISP fields**
+
+Figure 7-3 shows the ISP fields. Solid lines denote fields where ISP signals are always transmitted if coexisting systems belonging to the appropriate system category are present. Dashed lines denote fields where ISP signals may or may not be present.
+
+### 7.2.1 Access system
+
+The ISP fields allocated to an access system are denoted ACCF1 and ACCF2. The valid combinations of the presence and phase of signals within these fields and their meaning are as shown in Table 7-1, where "Ph1" indicates ISP signal phase 1 and "Ph4" indicates ISP signal phase 4.
+
+**Table 7-1 – Meaning of the access ISP fields**
+
+| ACC ISP window |       | Meaning for network status           |
+|----------------|-------|--------------------------------------|
+| ACCF1          | ACCF2 |                                      |
+| Ph1            | Ph1   | Access TDM request partial bandwidth |
+| Ph1            | Ph4   | Access TDM request full bandwidth    |
+| Ph4            | Ph1   | Access FDM below 10 MHz on all TDMSS |
+| Ph4            | Ph4   | Access FDM below 14 MHz on all TDMSS |
+
+From Table 7-1, it may be seen that an access system is able to use:
+
+- ACCF1 to indicate its presence and whether it is using TDM or FDM.
+- ACCF2 to indicate whether it is using all its allocated resources (TDM full bandwidth, FDM below 14 MHz) or partial allocated resources (TDM partial bandwidth, FDM below 10 MHz).
+
+### 7.2.2 In-home systems
+
+The ISP fields allocated to the in-home systems are denoted I1F1, I1F2, I2F1, I2F2, IGF1 and IGF2. The valid combinations of the presence and phase of signals within these fields and their meaning are as shown in Tables 7-2, 7-3 and 7-4.
+
+**Table 7-2 – Meaning of the IHC1 ISP fields**
+
+| IHC1 ISP window |      | Meaning for network status                         |
+|-----------------|------|----------------------------------------------------|
+| I1F1            | I1F2 |                                                    |
+| Ph2             |      | IHC1 system present                                |
+| Ph2             | Ph5  | IHC1 system must start resynchronization procedure |
+| Ph2             | Ph4  | Interference threshold exceeded                    |
+
+**Table 7-3 – Meaning of the IHC2 ISP fields**
+
+| IHC2 ISP window                                                                 |      | Meaning for network status                         |
+|---------------------------------------------------------------------------------|------|----------------------------------------------------|
+| I2F1                                                                            | I2F2 |                                                    |
+| Ph3                                                                             |      | IHC2 system present                                |
+| Ph3                                                                             | Ph2  | IHC2 system must start resynchronization procedure |
+| Ph3                                                                             | Ph4  | Interference threshold exceeded                    |
+| NOTE – A coexisting system may ignore undefined signals detected in ISP window. |      |                                                    |
+
+**Table 7-4 – Meaning of ITU-T G.996x ISP fields**
+
+| IH-G ISP window                                                                 |      | Meaning for network status                                         |
+|---------------------------------------------------------------------------------|------|--------------------------------------------------------------------|
+| IGF1                                                                            | IGF2 |                                                                    |
+| Ph5                                                                             |      | ITU-T G.996x in-home system present                                |
+| Ph5                                                                             | Ph3  | ITU-T G.996x in-home system must start resynchronization procedure |
+| Ph5                                                                             | Ph4  | Interference threshold exceeded                                    |
+| NOTE – A coexisting system may ignore undefined signals detected in ISP window. |      |                                                                    |
+
+From Tables 7-2, 7-3 and 7-4, it may be seen that in-home systems are able to use:
+
+- I1F1/I2F1/IGF1 to indicate presence.
+- I1F2/I2F2/IGF2 to indicate whether or not the device supports FDM.
+
+An ITU-T G.996x system enters the resynchronization procedure whenever it detects a signal with Phase 3 in IGF2. Similarly, an IHC1 system enters the resynchronization procedure whenever it detects a signal with Phase 5 in I1F2, and an IHC2 system enters the resynchronization procedure whenever it detects a signal with Phase 2 in I2F2.
+
+### 7.2.3 ISP signal placement
+
+In order to compensate for variations in synchronization, zero-crossing detection, load induced phase shifts, etc., the duration of the ISP signal is less than that of the ISP window. When transmitting an ISP signal, it should be placed in the centre of the ISP field. The structure of the ISP field is shown in Figure 7-4. Requirements for zero-crossing detection are specified in clause 14.3.
+
+![Figure 7-4: Composition of an ISP field. The diagram shows a horizontal line representing the timeline of an ISP field. The total length is labeled 'ISP_FIELD_LEN'. Within this field, there is a central 'ISP Signal' represented by a trapezoidal shape (a pulse that ramps up, stays high, ramps down, and stays low). The signal is centered within the field. The field is divided into three segments: 'ISP_MARGIN' on the left, 'ISP_SIGNAL_LEN' in the center (containing the signal), and 'ISP_MARGIN' on the right. The segments outside the signal are labeled 'Silence'. The diagram is labeled 'G.9972(10)_F7-4' at the bottom right.](12de9b926df0384ec07702671827c9cd_img.jpg)
+
+Figure 7-4: Composition of an ISP field. The diagram shows a horizontal line representing the timeline of an ISP field. The total length is labeled 'ISP\_FIELD\_LEN'. Within this field, there is a central 'ISP Signal' represented by a trapezoidal shape (a pulse that ramps up, stays high, ramps down, and stays low). The signal is centered within the field. The field is divided into three segments: 'ISP\_MARGIN' on the left, 'ISP\_SIGNAL\_LEN' in the center (containing the signal), and 'ISP\_MARGIN' on the right. The segments outside the signal are labeled 'Silence'. The diagram is labeled 'G.9972(10)\_F7-4' at the bottom right.
+
+**Figure 7-4 – Composition of an ISP field: ISP signal and two ISP margins (silence periods)**
+
+## 7.3 Network status
+
+By monitoring the signals transmitted within the ISP windows allocated to other coexisting systems, a coexisting system is able to detect the number and type of other coexisting systems present on the line and the resource requirements of the access system (i.e., partial/full bandwidth).
+
+By monitoring the signals within its own ISP window, a coexisting system is able to detect a resynchronization request from any of the other coexisting systems.
+
+Signals are valid if they occur in *VALID\_SIGNAL\_COUNT* consecutive ISP windows for a given system. Any node shall decide that a system is present if the node detects at least *VALID\_SIGNAL\_COUNT* consecutive ISP signals of the appropriate phase in the appropriate ISP field and shall update its network status accordingly. Any node shall recognize that a system is no
+
+longer present if it does not detect such signals for SYSTEM\_NOT\_DETECTED consecutive synchronization periods and shall update the network status accordingly.
+
+Information about the systems on the powerline includes:
+
+- In-home systems
+  - Presence
+  - Resynchronization request from other system
+  - "Interference threshold exceeded" to access system
+- Access system
+  - Presence
+  - TDM or FDM
+  - Full or partial resource allocation requirement
+
+This set of instantaneous information is termed the network status. Network status is used to determine the allocation of resources to each coexisting system.
+
+Coexisting devices are able to determine the network status every  $4 \cdot T_{\text{ISP}}$  and update the network status every  $T_{\text{ISP}}$ . The network status of a coexisting system is determined by the systems that are present and detected by that device on the shared medium.
+
+In the example shown in Figure 7-5, ISP signals are not transmitted in the ISP window assigned to IHC1, hence ACC, IH-G and IHC2 do not detect signals in the IHC1 ISP window and infer that IHC1 is not present. The network status = {ACC, IHC2, IH-G}. In this case, ACC, IH-G and IHC2 are able to share the resources that would be allocated to IHC1, according to a policy defined in clause 9.
+
+![Figure 7-5: Example ISP window sequence when no IHC1 is present. The diagram shows a timeline with 8 time slots (0-7), each representing a multiple of T_ISP. The sequence of active systems is: 0: ACC (blue bar), 1: (empty dashed box), 2: IHC2 (orange bar), 3: IH-G (green bar), 4: ACC (blue bar), 5: (empty dashed box), 6: IHC2 (orange bar), 7: IH-G (green bar). The x-axis is labeled 'Time' and '(multiples of T_ISP)'. The diagram is labeled G.9972(10)_F7-5.](ca80b99f7e1d6e6b854f22190f2e14d8_img.jpg)
+
+Figure 7-5: Example ISP window sequence when no IHC1 is present. The diagram shows a timeline with 8 time slots (0-7), each representing a multiple of T\_ISP. The sequence of active systems is: 0: ACC (blue bar), 1: (empty dashed box), 2: IHC2 (orange bar), 3: IH-G (green bar), 4: ACC (blue bar), 5: (empty dashed box), 6: IHC2 (orange bar), 7: IH-G (green bar). The x-axis is labeled 'Time' and '(multiples of T\_ISP)'. The diagram is labeled G.9972(10)\_F7-5.
+
+Figure 7-5 – Example ISP window sequence when no IHC1 is present
+
+# 8 Coexistence resources
+
+The ISP allows coexisting systems to coexist in the time domain (TDM) and/or the frequency domain (FDM). This clause defines the resource allocation.
+
+## 8.1 Frequency domain multiplex (FDM)
+
+Within ISP, FDM may only be invoked by an access system. The overall FDM scheme consists of two frequency bands. The upper band is shared by in-home systems, the lower band reserved for access systems.
+
+One of two FDM band separation frequencies (10 MHz or 14 MHz) are signalled by the access system, denoting "Full Bandwidth" and "Partial Bandwidth" FDM modes. The "Full Bandwidth" FDM band separation frequency is 14 MHz, the "Partial Bandwidth" FDM band separation frequency is 10 MHz. Whichever mode is chosen by the access system is dependent upon its overall bandwidth requirements.
+
+## 8.2 Time domain multiplex (TDM)
+
+The ISP allows TDM to be implemented between coexisting in-home systems and between coexisting in-home systems and an access system.
+
+The access system may indicate its TDM resource requirements as either "Full Bandwidth" or "Partial Bandwidth". This request impacts the TDM resource allocation between the coexisting systems.
+
+The period between each ISP window is divided equally into three "TDM Units" (TDMU). In a period of  $T_H$ , there are 12 TDMUs numbered from 0 to 11. Each TDMU, in turn, is divided equally into eight "TDM Slots" (TDMS), numbered 0 to 7. The duration of a TDMU is given by  $TDM\_UNIT\_LEN$  and that of a TDMS by  $TDM\_SLOT\_LEN$ . The overall ISP TDMA structure is shown in Figure 8-1 with the TDMU structure shown in Figure 8-2.
+
+If two adjacent TDMSs are assigned to different coexisting system categories, then a silence period is included. Figure 8-3 shows the general TDMA structure with an example of silence periods in a certain TDM allocation. The TDMS silence period is the duration of the  $ISP\_MARGIN$  (see clause 7) and shall be inserted at the beginning of the TDMS. In the case that the TDMS starts with an ISP window, the silence period is already part of the ISP window.
+
+Depending on the network status, each TDMS within a TDMU is allocated to a particular system category. The same TDMS is allocated to the same system category in each TDMU (e.g., ACC could be allocated "TDMS#3" and "TDMS#4" in each TDMU).
+
+The network status sensed by one node of a coexisting system may be different to the network status sensed by another node of the same coexisting system.
+
+![Figure 8-1 – General TDMA structure of the ISP. The diagram illustrates the hierarchical time structure of the ISP. At the top, a timeline shows alternating ISP Windows (green) and TDM periods for ACC (yellow), IHC1 (light blue), IHC2 (purple), and IH-G (dark green). The duration of an ISP window is labeled T_ISP. Below this, a zoomed-in view shows a sequence of TDMUs (TDMU #0 to #4) separated by ISP Windows. Each TDMU is further divided into TDMSs (TDMS0 to TDMS7). The diagram shows the allocation of these TDMSs to different system categories: IH-G, ACC, and IH-G. A sine wave at the bottom represents the AC power cycle, with labels indicating that 1 TDMU corresponds to 2 AC cycles. A legend at the bottom left shows a red vertical bar labeled ISP_MARGIN.](73dff6b45b2b9ffd384bab3235f869af_img.jpg)
+
+The diagram illustrates the general TDMA structure of the ISP. It is divided into three horizontal levels of time resolution:
+
+- Top Level:** A timeline showing the sequence of ISP Windows (green) and TDM periods for various system categories: ACC (yellow), IHC1 (light blue), IHC2 (purple), and IH-G (dark green). The duration of an ISP window is labeled  $T_{ISP}$ .
+- Middle Level:** A zoomed-in view of the TDM period, showing a sequence of TDMUs (TDMU #0, #1, #2, #3, #4) separated by ISP Windows. Each TDMU is further divided into TDMSs (TDMS0 to TDMS7).
+- Bottom Level:** A detailed view of the TDMS allocation within a TDMU. It shows the sequence of TDMSs (TDMS0, TDMS1, TDMS2, ..., TDMS7) and their corresponding system categories: IH-G, IH-G, IH-G, ACC, IH-G, IH-G, IH-G, ACC, IH-G. A sine wave at the bottom represents the AC power cycle, with labels indicating that 1 TDMU corresponds to 2 AC cycles.
+
+A legend at the bottom left shows a red vertical bar labeled **ISP\_MARGIN**.
+
+Figure 8-1 – General TDMA structure of the ISP. The diagram illustrates the hierarchical time structure of the ISP. At the top, a timeline shows alternating ISP Windows (green) and TDM periods for ACC (yellow), IHC1 (light blue), IHC2 (purple), and IH-G (dark green). The duration of an ISP window is labeled T\_ISP. Below this, a zoomed-in view shows a sequence of TDMUs (TDMU #0 to #4) separated by ISP Windows. Each TDMU is further divided into TDMSs (TDMS0 to TDMS7). The diagram shows the allocation of these TDMSs to different system categories: IH-G, ACC, and IH-G. A sine wave at the bottom represents the AC power cycle, with labels indicating that 1 TDMU corresponds to 2 AC cycles. A legend at the bottom left shows a red vertical bar labeled ISP\_MARGIN.
+
+Figure 8-1 – General TDMA structure of the ISP
+
+![Figure 8-2: Structure of TDMU. A horizontal timeline shows a sequence of eight blocks labeled TDMS #0 through TDMS #7. Above the sequence, a double-headed arrow indicates a duration of 'TDMU = 2 AC cycles'. Below the sequence, an arrow labeled 'Time' points to the right. Another arrow labeled 'TDMS boundaries' points to the vertical lines between the blocks. The text 'G.9972(10)_F8-2' is in the bottom right corner.](e69b9188aa2c14ec6b21c83f711fef65_img.jpg)
+
+Figure 8-2: Structure of TDMU. A horizontal timeline shows a sequence of eight blocks labeled TDMS #0 through TDMS #7. Above the sequence, a double-headed arrow indicates a duration of 'TDMU = 2 AC cycles'. Below the sequence, an arrow labeled 'Time' points to the right. Another arrow labeled 'TDMS boundaries' points to the vertical lines between the blocks. The text 'G.9972(10)\_F8-2' is in the bottom right corner.
+
+NOTE – Each TDMS is used exclusively by a coexisting system category.
+
+**Figure 8-2 – Structure of TDMU**
+
+![Figure 8-3: General TDMA structure and an example of silence margins in a certain TDMA allocation. The diagram consists of three horizontal layers. The top layer shows a sequence of colored blocks: green (ISP), yellow (ACC), cyan (IHC1), purple (IHC2), and green (IH-G). A double-headed arrow labeled 'T_isp' spans one yellow block. The middle layer shows a sequence of green blocks labeled TDMU #0, TDMU #1, TDMU #2, TDMU #3, TDMU #4, with ellipses at the ends. Red blocks are shown at the boundaries of TDMU #0, #2, and #3. A double-headed arrow labeled 'T_isp' spans from the start of TDMU #0 to the start of TDMU #2. The bottom layer shows a sequence of blocks: red (ISP_MARGIN), cyan (IH-G), cyan (IH-G), cyan (IH-G), yellow (ACC), cyan (IH-G), red (ISP_MARGIN), cyan (IH-G), cyan (IH-G), cyan (IH-G), yellow (ACC), cyan (IH-G). A double-headed arrow labeled 'TDM slot (TDMS)' spans the first three cyan blocks. Below this, a sine wave is shown. Two double-headed arrows labeled '1 TDMU = 2 AC cycles' span the first and second sets of three cyan blocks. The text 'G.9972(10)_F8-3' is in the bottom right corner. A legend at the bottom left shows a red block labeled 'ISP_MARGIN'.](e180f2b5fcbe8001554a7c0677cd3f82_img.jpg)
+
+Figure 8-3: General TDMA structure and an example of silence margins in a certain TDMA allocation. The diagram consists of three horizontal layers. The top layer shows a sequence of colored blocks: green (ISP), yellow (ACC), cyan (IHC1), purple (IHC2), and green (IH-G). A double-headed arrow labeled 'T\_isp' spans one yellow block. The middle layer shows a sequence of green blocks labeled TDMU #0, TDMU #1, TDMU #2, TDMU #3, TDMU #4, with ellipses at the ends. Red blocks are shown at the boundaries of TDMU #0, #2, and #3. A double-headed arrow labeled 'T\_isp' spans from the start of TDMU #0 to the start of TDMU #2. The bottom layer shows a sequence of blocks: red (ISP\_MARGIN), cyan (IH-G), cyan (IH-G), cyan (IH-G), yellow (ACC), cyan (IH-G), red (ISP\_MARGIN), cyan (IH-G), cyan (IH-G), cyan (IH-G), yellow (ACC), cyan (IH-G). A double-headed arrow labeled 'TDM slot (TDMS)' spans the first three cyan blocks. Below this, a sine wave is shown. Two double-headed arrows labeled '1 TDMU = 2 AC cycles' span the first and second sets of three cyan blocks. The text 'G.9972(10)\_F8-3' is in the bottom right corner. A legend at the bottom left shows a red block labeled 'ISP\_MARGIN'.
+
+**Figure 8-3 – General TDMA structure and an example of silence margins in a certain TDMA allocation**
+
+## 8.3 FDM/TDM modes
+
+Access and in-home systems shall be capable of operating in TDM mode and may be capable of operating in FDM mode.
+
+An FDM access system shall monitor all fields in other ISP windows in order to:
+
+- detect the presence of in-home systems; and
+- detect the interference level value caused to them in the access FDM band ("interference threshold exceeded" or "interference threshold not exceeded").
+
+An FDM access system shall detect the FDM interference level value at an in-home device and act accordingly within 5 seconds of the in-home device beginning to indicate the interference level by transmitting in the appropriate ISP window.
+
+When an in-home system detects the presence of an FDM access system, then the in-home system may indicate "interference threshold exceeded" by signalling in the appropriate field of its own ISP window. The in-home system may signal in two different ways:
+
+- Transmitting a burst of `VALID_SIGNAL_COUNT` signals to indicate to access that it is requesting it to reduce the interference level. In this case, access will attempt to reduce the interference level in the in-home band. After 5 seconds, the in-home system may re-evaluate the interference level caused by access.
+- Transmitting the signals continuously to indicate to access that it has to switch to TDM mode. In this case, the access system shall enter the TDM mode and signal such in the access fields. The access system may continue to utilize only the frequency region used in the FDM mode rather than the whole bandwidth. The in-home system shall synchronize to the access system.
+
+The criteria on how to transmit the "interference threshold exceeded" signal by the in-home system is vendor discretionary.
+
+Transmission of "interference threshold exceeded" signal by in-home system shall only be allowed when access is signalling FDM mode.
+
+## 8.4 Parameters
+
+This clause specifies values for parameters used in this Recommendation. These parameters are referenced in various clauses.
+
+Tables 8-1, 8-2 and 8-3 indicate timing parameters in terms of nominal line cycle frequencies. Since the line cycle frequencies vary around these nominal values, the actual parameter values shall be interpreted in terms of the number of AC line cycles.
+
+**Table 8-1 – Synchronization parameters**
+
+| Parameter                              | Definition                                                                                                                                                                                     | Value                                         |
+|----------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------|
+| <code>AC_CYCLE</code>                  | AC mains cycle                                                                                                                                                                                 |                                               |
+| $T_0$                                  | Sync point interval                                                                                                                                                                            | $(1/6) \times AC\_CYCLE$                      |
+| <code>TDM_UNIT_LEN</code>              | Time length of TDM unit                                                                                                                                                                        | $2 \times AC\_CYCLE$                          |
+| <code>TDM_SLOT_LEN</code>              | Time length of TDM slot                                                                                                                                                                        | $(1/8) \times TDM\_UNIT\_LEN$                 |
+| $T_{ISP}$                              | Period of ISP windows                                                                                                                                                                          | $3 \times TDM\_UNIT\_LEN$                     |
+| $T_H$                                  | Synchronization period for in-home systems and for access systems                                                                                                                              | $4 \times T_{ISP}$<br>$(24 \times AC\_CYCLE)$ |
+| <code>VALID_SIGNAL_COUNT</code>        | Number of consecutive ISP windows required to judge that the detected ISP signal is valid.                                                                                                     | 2                                             |
+| <code>VALID_SIGNAL_COUNT_SEARCH</code> | Number of consecutive ISP windows required to judge that the detected ISP signal is valid when it searches for ISP signals for <code>ISP_STARTUP_TIME</code> or <code>ISP_RESYNC_WAIT</code> . | 1                                             |
+| <code>SYSTEM_NOT_DETECTED</code>       | Number of consecutive ISP windows required to judge that a system is no longer present.                                                                                                        | 5                                             |
+
+**Table 8-2 – ISP window parameters**
+
+| Parameter      | Definition                                                                    | Value          |
+|----------------|-------------------------------------------------------------------------------|----------------|
+| ISP_FIELD_LEN  | Time length of an ISP field                                                   | 245.76 $\mu$ s |
+| ISP_SIGNAL_LEN | Time length of an ISP signal                                                  | 81.92 $\mu$ s  |
+| ISP_MARGIN     | Margins within an ISP field which are located on both sides of the ISP signal | 81.92 $\mu$ s  |
+| ISP_OFFSET     | Offset length from the sync point to the beginning of the ISP window          | 200 $\mu$ s    |
+
+**Table 8-3 – Start-up and resynchronization parameters**
+
+| Parameter                   | Definition                                                                                                                                                                                                                               | Value   |
+|-----------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------|
+| ISP_STARTUP_TIME            | Duration for access and in-home systems to search for ISP signals from other coexisting systems (the coexisting system shall not transmit any signals during this time)                                                                  | $2T_H$  |
+| ACCESS_ENTER_TIME           | Duration for an access system master node to consecutively transmit resynchronization signals to unsynchronized systems                                                                                                                  | $10T_H$ |
+| RESYNC_SIG                  | The randomly selected number of resynchronization signal transmissions by the current system to those systems with which it is attempting to resynchronize.<br>Minimum value = RESYNC_SIG_MIN (5)<br>Maximum value = RESYNC_SIG_MAX (10) | 5~10    |
+| ISP_RESYNC_WAIT             | Duration for an in-home system to stop all ISP signal/data transmission in the network and search for ISP signals from other coexisting systems, after receiving resynchronization request signals                                       | $T_H$   |
+| RESOURCE_RE-ALLOCATION_TIME | Duration for access and in-home systems to re-allocate their resource allocation after detecting a new network status                                                                                                                    | $T_H$   |
+
+# 9 Resource allocation
+
+## 9.1 TDM resource allocation for access systems
+
+The policy for resource sharing between access and a group of in-home systems shall be based on the following rule:
+
+When the access system requires 50% or more of the available resources, and the group of in-home systems requires 50% or more of the available resource, the access system shall receive 50% of the resources and the group of in-home systems shall receive the remaining 50% of the resources.
+
+The access system or the group of in-home systems may use additional resources above 50% if not required by the other coexisting system. A system shall change its use of resources within a duration given by RESOURCE\_RE-ALLOCATION\_TIME.
+
+## 9.2 TDM resource allocation
+
+The general procedure for TDMS allocation is to start allocating TDMS for the case of a full network status {ACC, IH-G, IHC1, IHC2}, and then to create other allocations by assigning the TDMS of the absent system to the present systems.
+
+The TDM resource allocation is shown in Figure 9-1. The right hand side of this table indicates which systems are allocated to which TDMS within the TDMU. The left hand side indicates which systems are present on the powerline – i.e., the network status.
+
+Each system shall determine the network status and adjust its use of resources accordingly.
+
+Each node may use TDMSs specified in Figure 9-1, according to the network status, and shall not use TDMSs allocated to other systems. As the network status changes, a system shall change its use of resources within a duration given by RESOURCE\_RE-ALLOCATION\_TIME.
+
+| Index | ISP Field |      |      |      |  | TDM Slot number |      |      |      |      |      |      |      |
+|-------|-----------|------|------|------|--|-----------------|------|------|------|------|------|------|------|
+|       | ACC       | IHC1 | IHC2 | IH-G |  | 0               | 1    | 2    | 3    | 4    | 5    | 6    | 7    |
+| 1     | -         | -    | -    | IH-G |  | IH-G            | IH-G | IH-G | IH-G | IH-G | IH-G | IH-G | IH-G |
+| 2     | -         | IHC1 | -    | -    |  | IHC1            | IHC1 | IHC1 | IHC1 | IHC1 | IHC1 | IHC1 | IHC1 |
+| 3     | -         | -    | IHC2 | -    |  | IHC2            | IHC2 | IHC2 | IHC2 | IHC2 | IHC2 | IHC2 | IHC2 |
+| 4     | -         | IHC1 | -    | IH-G |  | IHC1            | IHC1 | IH-G | IHC1 | IHC1 | IH-G | IH-G | IH-G |
+| 5     | -         | IHC1 | IHC2 | -    |  | IHC1            | IHC1 | IHC2 | IHC2 | IHC2 | IHC1 | IHC1 | IHC2 |
+| 6     | -         | -    | IHC2 | IH-G |  | IH-G            | IHC2 | IHC2 | IHC2 | IHC2 | IH-G | IH-G | IH-G |
+| 7     | -         | IHC1 | IHC2 | IH-G |  | IHC1            | IHC1 | IHC2 | IHC2 | IHC2 | IH-G | IH-G | IH-G |
+| 8     | ACC (FB)  | -    | -    | -    |  | ACC             | ACC  | ACC  | ACC  | ACC  | ACC  | ACC  | ACC  |
+| 9     | ACC (PB)  | -    | -    | IH-G |  | IH-G            | IH-G | IH-G | IH-G | ACC  | ACC  | IH-G | IH-G |
+| 10    | ACC (FB)  | -    | -    | IH-G |  | IH-G            | IH-G | IH-G | ACC  | ACC  | ACC  | ACC  | IH-G |
+| 11    | ACC (PB)  | IHC1 | -    | -    |  | IHC1            | IHC1 | IHC1 | IHC1 | ACC  | ACC  | IHC1 | IHC1 |
+| 12    | ACC (FB)  | IHC1 | -    | -    |  | IHC1            | IHC1 | IHC1 | ACC  | ACC  | ACC  | ACC  | IHC1 |
+| 13    | ACC (PB)  | -    | IHC2 | -    |  | IHC2            | IHC2 | IHC2 | IHC2 | ACC  | ACC  | IHC2 | IHC2 |
+| 14    | ACC (FB)  | -    | IHC2 | -    |  | IHC2            | IHC2 | IHC2 | ACC  | ACC  | ACC  | ACC  | IHC2 |
+| 15    | ACC (PB)  | IHC1 | -    | IH-G |  | IHC1            | IHC1 | IH-G | IHC1 | ACC  | ACC  | IH-G | IH-G |
+| 16    | ACC (FB)  | IHC1 | -    | IH-G |  | IHC1            | IHC1 | IH-G | ACC  | ACC  | ACC  | ACC  | IH-G |
+| 17    | ACC (PB)  | IHC1 | IHC2 | -    |  | IHC1            | IHC1 | IHC2 | IHC2 | ACC  | ACC  | IHC1 | IHC2 |
+| 18    | ACC (FB)  | IHC1 | IHC2 | -    |  | IHC1            | IHC1 | IHC2 | ACC  | ACC  | ACC  | ACC  | IHC2 |
+| 19    | ACC (PB)  | -    | IHC2 | IH-G |  | IH-G            | IHC2 | IHC2 | IHC2 | ACC  | ACC  | IH-G | IH-G |
+| 20    | ACC (FB)  | -    | IHC2 | IH-G |  | IH-G            | IHC2 | IHC2 | ACC  | ACC  | ACC  | ACC  | IH-G |
+| 21    | ACC (PB)  | IHC1 | IHC2 | IH-G |  | IHC1            | IHC1 | IHC2 | IHC2 | ACC  | ACC  | IH-G | IH-G |
+| 22    | ACC (FB)  | IHC1 | IHC2 | IH-G |  | IHC1            | IHC1 | IHC2 | ACC  | ACC  | ACC  | ACC  | IH-G |
+
+Figure 9-1 – Resource allocation
+
+It must be noted that the ISP window occurs in TDMS#0 of every TDMU#0, TDMU#3, TDMU#6 and TDMU#9. Therefore, the system category that occupies TDMS#0 will be very slightly penalized as no data can be transmitted during the ISP window.
+
+# 10 Start-up and resynchronization procedures
+
+In order to allow coexisting systems to synchronize to the appropriate ISP window, and hence to effectively coexist, the ISP defines:
+
+- procedures for system start-up;
+- triggers and procedures for re-synchronizing to a different set of ISP windows.
+
+## 10.1 Start-up procedure
+
+This clause is concerned with the case when a new node joins a system and when global start-up is required, for example, after a power outage. The start-up procedure ensures that the new station is able to detect the presence of other networks already transmitting ISP signals, and to coordinate with the existing networks.
+
+### 10.1.1 Start-up procedure for an access system
+
+This Recommendation assumes the presence of, at most, one access system; therefore, if a new access station joins the network, it will never detect two unsynchronized access networks. The access system is likely to span a relatively large geographic area, and thus may occupy the same powerline medium with any number of in-home systems.
+
+If an access system is deployed for the first time in the area or when a new access node joins an existing access network, then the access station(s) shall follow the start-up procedure defined in this Recommendation for access networks.
+
+- The access station(s) shall search for ISP signals from other coexisting systems at every sync point for a period given by `ISP_STARTUP_TIME`. Any node shall decide that a system is present if the node detects at least `VALID_SIGNAL_COUNT_SEARCH` consecutive ISP signals of the appropriate phase in the appropriate ISP field and shall update its network status accordingly.
+- Once an access station successfully joins an access network and the `ISP_STARTUP_TIME` duration has expired, it shall send a message to the ACC master node notifying the presence and status of any in-home systems.
+- Additionally, the ACC master node shall send a message to the new station indicating the mode of the access network and timing of the ISP signal which it shall begin transmitting in the ISP access fields.
+- If any in-home coexisting systems are detected that are not synchronized with the access system, then a resynchronization signal shall be transmitted in the resynchronization field of the out of sync in-home systems for `ACCESS_ENTER_TIME`.
+- The new access stations shall be restricted to transmission and reception of management messages for joining the access network and ISP management only until the procedure described herein is complete, including resynchronization of any out of sync in-home networks.
+
+Access systems should have the possibility of initiating a resynchronization (similar to a global start-up after power outage).
+
+### 10.1.2 Start-up procedure for an in-home system
+
+When a new in-home node is powered up or joins an existing in-home network, then the in-home station(s) shall follow the start-up procedure defined in this Recommendation for in-home networks.
+
+- The in-home station(s) shall search for ISP signals from other coexisting systems at every sync point for a period given by `ISP_STARTUP_TIME`. The detection information from each slave node shall be sent to the master node using the `ISP_DetectionReport` management message. Any node shall decide that a system is present if the node detects at least `VALID_SIGNAL_COUNT_SEARCH` consecutive ISP signals of the appropriate phase in the appropriate ISP field and shall update its network status accordingly.
+
+- The master node shall determine the ISP sequence with which to synchronize, based on the detection information received from the slave nodes and according to the following rules:
+  - If no ISP sequence is detected during the search period given by `ISP_STARTUP_TIME`, then the network manager of the in-home system shall determine the timing of the ISP windows itself and shall start transmitting ISP signals in its designated ISP window.
+  - If only one ISP sequence is detected during the search period, then:
+    - If the detected sequence does not include any resynchronization requests, then the network manager of the in-home system shall lock onto the detected sequence and shall start transmitting ISP signals in its designated ISP window.
+    - If the detected sequence includes a re-synchronization request, then the network manager of the in-home system shall re-enter the start-up procedure and shall begin to search for ISP signals once again.
+  - If two or more ISP sequences are detected during the search period, then:
+    - If one of the ISP sequences includes an access system, the network manager of the in-home system shall lock onto this sequence and shall start transmitting an ISP signal in its designated ISP window.
+    - If none of the ISP sequences includes an access sequence, then:
+      - If there is only one ISP sequence that does not include a re-synchronization request, the network manager of the in-home system shall select and lock onto this sequence and shall start transmitting an ISP signal in its designated ISP window.
+      - If there are two or more ISP sequences that do not include a resynchronization request, the network manager of the in-home system shall select one from these sequences, lock onto it and shall start transmitting an ISP signal in its designated ISP window.
+      - If there is no in-home ISP sequence that does not include a resynchronization request, the network manager of the in-home system shall re-enter the start-up procedure and shall begin to search for ISP signals once again.
+- If the master node determines, based on the detection information, that there are more than one ISP sequence, it shall transmit the `ISP_DirectResyncTransmission` message to the slave nodes instructing them to transmit resynchronization signals with phase vector `Ph5` or `Ph2` or `Ph3` (as appropriate) to the ISP sequences with which the master node has not synchronized. The number of re-sync transmissions (`RESYNC_SIG`) is randomly selected between `RESYNC_SIG_MIN` and `RESYNC_SIG_MAX`.
+- Once an in-home node successfully joins an in-home network and the `ISP_STARTUP_TIME` duration has expired, if it is not the master node of the in-home network, it shall send a system specific management message to the master node notifying the presence and status of any access and/or in-home systems. The new node shall follow any instructions indicated in any system specific management messages transmitted to it.
+- If the master node detects the presence of an access system either directly or indirectly, from receiving a system specific management message, it shall immediately execute the resynchronization procedure defined in clause 10.2, in order to synchronize with the access system.
+- If the master node detects the presence of an out of sync in-home coexisting system either directly or indirectly, from receiving a system specific management message, it shall immediately execute the resynchronization procedure defined in clause 10.2.
+
+- Any new in-home station shall be restricted to transmission and reception of management messages for joining the in-home network and ISP management only until the procedure described herein is complete, including resynchronization of any out of sync in-home networks. When the new station detects no ISP signals of its category, it shall not transmit any frames until it starts to transmit ISP signals.
+
+## 10.2 Resynchronization procedure
+
+- Note that an access system cannot be resynchronized.
+- An in-home system that is synchronized with an access system shall not resynchronize and shall ignore any resynchronization signal transmitted in its resynchronization field. Resynchronization is always handled by the master node.
+
+### 10.2.1 Access requests resynchronization
+
+- If an out of synchronization in-home system is detected by a station belonging to an access system, the station should immediately send a message to the ACC master notifying that an out of sync in-home coexisting system was detected.
+- The access station that detected the out of sync in-home coexisting system shall transmit in the re-sync field of the in-home system an ISP signal of Ph5 if the in-home system is IHC1, Ph2 if the in-home system is IHC2 or Ph3 if the in-home system is ITU-T G.996x for RESYNC\_SIG\_MAX times.
+- At the same time, the access station shall continue to transmit its own ISP sequence (i.e., ISP signals in its access ISP window) in order to provide the reference to which the in-home system shall synchronize.
+
+### 10.2.2 In-home detects re-sync signal in its window
+
+Whether an in-home system resynchronizes to a different ISP sequence or not is decided by the master node according to the following procedure:
+
+- If the in-home system is already synchronized with an access system, then it shall ignore the re-sync request.
+- An in-home slave node that detects an ISP resynchronization signal (Ph5 or Ph2 or Ph3) in the resynchronization field of its ISP window shall immediately send an ISP\_ResyncDetected message to the master node indicating a resynchronization signal was detected.
+- A master node that:
+  - either detects a resynchronization signal in its ISP window or receives an ISP\_ResyncDetected message; and
+  - is not synchronized with an access system; and
+  - is not currently transmitting resynchronization signals;
+  - shall immediately start the resynchronization procedure.
+
+The master node shall comply with the following:
+
+- The master node transmits an ISP\_StartResync message to all slave nodes in the system. The master node and slave nodes suspend transmission of ISP signals and search for ISP signals at all sync points for ISP\_RESYNC\_WAIT. Any node shall decide that a system is present if the node detects at least VALID\_SIGNAL\_COUNT\_SEARCH consecutive ISP signals of the appropriate phase in the appropriate ISP field and shall update its network status accordingly.
+
+- After ISP\_RESYNC\_WAIT and an access system is detected, the master node synchronizes to the access system, resumes transmission of ISP signals and data, and transmits the ISP\_ResyncFinished management message to all slave nodes. In this case, the resynchronization procedure is finished at this step.
+- If the master node does not detect an access system during ISP\_RESYNC\_WAIT, the master node resumes transmission of data and ISP signals (at the same sync points as before the resynchronization procedure started). The master node then begins a second ISP\_RESYNC\_WAIT period.
+- After the second ISP\_RESYNC\_WAIT, the master node decides the sync point to lock onto from both what it detected during the first ISP\_RESYNC\_WAIT and what it is informed by its slave nodes (using the ISP\_DetectionReport message) during the second ISP\_RESYNC\_WAIT. If any slave node detected an access ISP sequence, then the master node selects the access sequence. Otherwise, a sync point that does not include a re-sync signal and is not the same as the sync point before this state is selected. The master node resumes transmission of data and transmits the ISP\_ResyncFinished management message to all slave nodes.
+- If the master node neither detects nor is informed of any ISP sequences that satisfy the above conditions, then the master node continues synchronizing with the current sync point.
+
+Slave nodes shall comply with the following during resynchronization:
+
+- Immediately after it receives the ISP\_StartResync message from its master node, an in-home slave node stops all ISP signals and frame transmissions, and searches for ISP signals at all sync points for ISP\_RESYNC\_WAIT. Any node shall decide that a system is present if the node detects at least VALID\_SIGNAL\_COUNT\_SEARCH consecutive ISP signals of the appropriate phase in the appropriate ISP field and shall update its network status accordingly.
+- After ISP\_RESYNC\_WAIT, the slave node resumes transmission of ISP signals and transmits an ISP\_DetectionReport message to its master node if any ISP sequence was detected during the search period.
+- The slave node updates the location of the ISP window starting from the next ISP window after receiving the ISP\_ResyncFinished management message from its master node. The sync point that the slave node synchronizes to is informed by the ISP\_ResyncFinished management message.
+
+Just after the resynchronization procedure, the master node and all slave nodes shall transmit re-sync request signals to both those sync points that were detected but not selected and the sync point to which the system synchronized before the resynchronization procedure started. The number of re-sync signal transmissions (RESYNC\_SIG) is decided by the master node. If the master node's system is synchronized to an access system, RESYNC\_SIG is always equal to RESYNC\_SIG\_MAX. Otherwise, the master node decides the value of RESYNC\_SIG randomly between RESYNC\_SIG\_MIN and RESYNC\_SIG\_MAX and shall transmit this to all slave nodes using the ISP\_DirectResyncTransmission message.
+
+### 10.2.3 In-home detects an unsynchronized access system
+
+If an in-home coexisting system detects the presence of an unsynchronized ISP sequence that includes an access system, then the in-home system shall comply with the following procedure:
+
+- The in-home system synchronizes its ISP signal transmission with the access system and transmits ISP signals in its corresponding ISP window.
+- The master node transmits an ISP\_IndicateState message to all its slave nodes in the same system to inform them of the coexistence state and the location of the next ISP window corresponding to the timing of the access system.
+
+- The master node transmits ISP signals with phase vector Ph5 or Ph2 or Ph3 in the re-sync field of any ISP sequence with which the in-home system had synchronized before it detected the access system. The re-sync signals are transmitted for each unsynchronized ISP sequence for RESYNC\_SIG\_MAX times.
+- The master node transmits an ISP\_DirectResyncTransmission message to command the slave nodes to transmit re-sync signals in the ISP sequence to which the in-home system had synchronized before it detected the access system. The number of re-sync signal transmissions shall be RESYNC\_SIG\_MAX, and it is contained within the ISP\_DirectResyncTransmission message.
+
+A node that also detected unsynchronized in-home coexisting systems that were not synchronized to the detected access system shall transmit re-sync signals to the sync points corresponding to the detected in-home systems. The number of re-sync signal transmissions shall be RESYNC\_SIG\_MAX.
+
+### 10.2.4 In-home system detects unsynchronized in-home systems
+
+If an in-home system detects the presence of one or more unsynchronized in-home ISP sequences and does not detect an unsynchronized access system, the in-home master node shall select whether it enters the resynchronization procedure itself or requests the unsynchronized systems to do so.
+
+When the master node selects the former, then the in-home system shall comply with the following procedure:
+
+- The master node selects one of the detected ISP sequences to synchronize with and transmits ISP signals in the corresponding ISP window of that detected ISP sequence.
+- The master node transmits an ISP\_IndicateState message to all its slave nodes in order to inform them of the coexistence state and the location of the next ISP window (corresponding to the timing of the new system). All slave nodes that receive this message shall cease to transmit any signals in the presence field of the previous ISP sequence and start transmitting in the new ISP sequence.
+- The master node transmits an ISP\_DirectResyncTransmission message in order to command slave nodes to transmit re-sync signals, with phase vector Ph5 or Ph2 or Ph3 (as appropriate), within the ISP sequence to unselected ISP sequences and to which the in-home system had previously synchronized. The value of RESYNC\_SIG is randomly selected between RESYNC\_SIG\_MIN and RESYNC\_SIG\_MAX by the master node, and is informed by the ISP\_DirectResyncTransmission message.
+
+When the master node decides to keep its sync point and requests other systems to synchronize to it, the in-home system shall comply with the following procedure:
+
+- The master node transmits an ISP\_DirectResyncTransmission message to all its slave nodes in order to command them to transmit re-sync signals in the ISP sequences of any unsynchronized systems they detected. The number of re-sync transmissions (RESYNC\_SIG) is randomly selected by the master node between RESYNC\_SIG\_MIN and RESYNC\_SIG\_MAX and is communicated to the slave nodes within the ISP\_DirectResyncTransmission message.
+- The master node also transmits re-sync signals in the ISP sequences of the unsynchronized systems that the master node detected. The re-sync signals are transmitted RESYNC\_SIG times.
+
+# 11 Power control procedures
+
+Nodes within a system may reduce the frequency or cease transmission of the ISP signals under certain circumstances, providing they continue to monitor the network status. If the network status contains only one system category, then the node may stop transmitting the ISP signals while still scanning for unsynchronized systems or for a new network status. Each node can make this decision autonomously based on the network status.
+
+If the sensed network status changes and other systems appear, then the node shall resume transmitting the ISP signals.
+
+Nodes shall transmit the ISP signals continuously for at least 60 s after the start-up and resynchronization procedure is completed.
+
+# 12 Time slot reuse
+
+For further study.
+
+# 13 Generic management message
+
+## 13.1 State indication messages
+
+Management messages in this clause are used to transfer ISP signal detection status information between the master node and slave nodes.
+
+**Table 13-1 – ISP state indication messages**
+
+| Message             | Direction                 |
+|---------------------|---------------------------|
+| ISP_IndicateState   | Master node → Slave nodes |
+| ISP_DetectionReport | Slave nodes → Master node |
+
+### 13.1.1 ISP\_IndicateState
+
+#### 13.1.1.1 Function
+
+ISP\_IndicateState management message is used by the master node to inform slave nodes of the current coexistence state and the location of the next ISP window for its own system.
+
+This message has some parameters.
+
+- Information that is sufficient for slave nodes to decide the utilizable frequency band and TDMS.
+- The location of the next ISP window.
+
+#### 13.1.1.2 Generation of ISP\_IndicateState
+
+A master node generates this message and sends to all slave nodes in the same system periodically. This message shall be sent to new slave nodes, all slave nodes every time the coexistence state changes, and all slave nodes antecedent to the change of the sync point to which the system is synchronized.
+
+#### 13.1.1.3 Effect of receipt
+
+A slave node that receives this message updates its coexistence state according to both the received message and ISP signals that the slave node has detected itself. The slave node shall also update the location of ISP windows according to the information contained within the message and should start signalling according to the new position.
+
+### 13.1.2 ISP\_DetectionReport
+
+#### 13.1.2.1 Function
+
+The ISP\_DetectionReport management message is used by a slave node to inform its master node of information relating to detected ISP signals.
+
+Parameters for this message are classified into two categories. An ISP\_DetectionReport message may contain information relating to one or both of these categories.
+
+The first category consists of information about detected ISP signals synchronized to the same sync points as the slave node itself. Parameters of the first category are as follows. A state parameter indicating the system's own technology is not necessary.
+
+- Access system state (TDMFull, TDMPartial, FDMFull, FDMPartial, not detected).
+- In-home system state for each technology (Detected, not detected).
+
+The second category consists of information about detected ISP signals synchronized to different sync points as the slave node itself. Parameters of the second category are as follows. The second category information may be a list of sets of the following parameters.
+
+- Access system state (TDMFull, TDMPartial, FDMFull, FDMPartial, not detected).
+- In-home system state for each technology (detected, not detected).
+- Resynchronization flag (Resynchronization signal detected, not detected).
+- Offset of the sync point to the current sync point.
+
+#### 13.1.2.2 Generation of ISP\_DetectionReport
+
+A slave node shall generate and send this message to its master node when:
+
+- the coexistence state communicated from the master node is different from the coexistence state determined by the slave node according to locally detected ISP signals;
+- the slave node detects one or more out-of-sync coexisting systems;
+- the slave node finishes the ISP\_RESYNC\_WAIT search period on the RE-SYNC state.
+
+#### 13.1.2.3 Effect of receipt
+
+When a master node receives this message from a slave node, it shall either update the coexistence state or start the re-synchronization procedure according to the information contained within the message.
+
+## 13.2 Resynchronization messages
+
+Management messages defined in this clause are used for the resynchronization procedure.
+
+**Table 13-2 – ISP resynchronization messages**
+
+| Message                      | Direction                 |
+|------------------------------|---------------------------|
+| ISP_StartResync              | Master node → Slave node  |
+| ISP_ResyncFinished           | Master node → Slave nodes |
+| ISP_ResyncDetected           | Slave node → Master node  |
+| ISP_DirectResyncTransmission | Master node → Slave nodes |
+
+### **13.2.1 ISP\_StartResync**
+
+#### **13.2.1.1 Function**
+
+The ISP\_StartResync management message is used to inform slave nodes that the master node has started the resynchronization procedure.
+
+#### **13.2.1.2 Generation of ISP\_StartResync**
+
+A master node shall generate and send this message to all slave nodes in the same system when the master node starts the resynchronization procedure.
+
+#### **13.2.1.3 Effect of receipt**
+
+A slave node that received this message shall enter the RE-SYNC state.
+
+### **13.2.2 ISP\_ResyncFinished**
+
+#### **13.2.2.1 Function**
+
+The ISP\_ResyncFinished management message is used to inform slave nodes that the resynchronization procedure is finished by the master node.
+
+This message shall contain parameters that show a new sync point to which the system shall synchronize and the number of transmissions of the re-sync signal.
+
+#### **13.2.2.2 Generation of ISP\_ResyncFinished**
+
+A master node shall generate and send this message to all slave nodes in the same system when the master node finishes the resynchronization procedure.
+
+#### **13.2.2.3 Effect of receipt**
+
+A slave node that receives this message shall immediately lock onto the specified sync point. The slave node shall also start to transmit re-sync signals at the sync points that are detected during the search period. The sync point with which the system had synchronized before the resynchronization procedure is also the target of re-sync signal transmission. The re-sync field of the sync point that is specified by this message shall not be signalled.
+
+### **13.2.3 ISP\_ResyncDetected**
+
+#### **13.2.3.1 Function**
+
+The ISP\_ResyncDetected management message is used by a slave node to inform the master node that it has detected re-sync signals in its own ISP window.
+
+#### **13.2.3.2 Generation of ISP\_ResyncDetected**
+
+A slave node shall generate and send this message to the master node when the slave node detects re-sync signals in its own ISP window.
+
+#### **13.2.3.3 Effect of receipt**
+
+A master node that receives this message may start the resynchronization procedure.
+
+### **13.2.4 ISP\_DirectResyncTransmission**
+
+#### **13.2.4.1 Function**
+
+The ISP\_DirectResyncTransmission management message is used to command slave nodes to transmit re-sync signals to out-of sync ISP windows.
+
+This message has a parameter to inform slave nodes of the number of transmissions of the re-sync signal.
+
+#### 13.2.4.2 Generation of ISP\_DirectResyncTransmission
+
+A master node shall generate and send this message to all slave nodes in the same system when the master node decides to make out-of-sync coexisting systems synchronize with itself.
+
+#### 13.2.4.3 Effect of receipt
+
+A slave node that received this message shall start to transmit re-sync signals to out-of-sync coexisting systems, according to the contents of the message.
+
+# 14 Signal transmission and detection
+
+## 14.1 Transmit PSD
+
+The PSD of ISP signals transmitted by a node shall be 8 dB lower than the PSD of the signals transmitted by the node when communicating with other nodes in the same coexisting system, except for the notches and the out-of-band PSD where the maximum PSD level could be the same as the signals transmitted by the node when communicating with other nodes in the same coexisting system.
+
+NOTE 1 – All devices send the ISP signal simultaneously, so the transmitted power is reduced in order to avoid non-compliance with radiated emissions regulations.
+
+NOTE 2 – The purpose of ISP is to allow sharing of the medium between coexisting systems when there could be interference. If the energy from one system reaches the other system below the noise level, then there is no real interference and so both systems could use the channel simultaneously without the need for ISP (avoiding the loss of up to 50% of the bandwidth). Sometimes there could be some interference causing some decrease in bandwidth, but this is better than directly losing 50% of the channel.
+
+The PSD shall be compliant with regulations in effect in the country where the system is used.
+
+The leakage signal level that may be output to the unused frequency band (#x or #y) when using FDM mode is shown in Figure 14-1, where  $f_s$  is the FDM band separation frequencies (10 MHz or 14 MHz) between access and in-home networks, and  $w$  is 6 MHz. The measurement for the limit is made using equipment with a resolution bandwidth of 10 kHz (dBm/10 kHz) or 9 kHz (dBm/9 kHz) and an RMS detector. The continuous line shall be met with the average measurement. The dashed line shall be met with Max hold measurement.
+
+![Figure 14-1: Leakage signal level graph showing Power (P) vs. frequency. The graph is divided into two channels, Channel #x and Channel #y, separated by a boundary at f_s. Channel #x is to the left of f_s, and Channel #y is to the right. The power level in Channel #x is shown by a solid orange line that is flat at -95 dBm/Hz until f_s - w, then rises to -90 dBm/Hz at f_s. The power level in Channel #y is shown by a solid blue line that is flat at -95 dBm/Hz until f_s + w, then rises to -90 dBm/Hz at f_s. The out-of-band power level for Channel #y is indicated by a dashed orange line at -90 dBm/Hz, and for Channel #x by a dashed blue line at -90 dBm/Hz. The text 'Channel #y out-of-band power level below bold threshold' is placed below the dashed orange line, and 'Channel #x out-of-band power level below light threshold' is placed below the dashed blue line. The x-axis is labeled 'frequency' and has markers for f_s - w, f_s, and f_s + w. The y-axis is labeled 'P' and has markers for -90 dBm/Hz and -95 dBm/Hz. The figure code G.9972(10)_F14-1 is shown in the bottom right corner.](b38d03866fe3a710ce4ef0d3f0db86aa_img.jpg)
+
+Figure 14-1: Leakage signal level graph showing Power (P) vs. frequency. The graph is divided into two channels, Channel #x and Channel #y, separated by a boundary at f\_s. Channel #x is to the left of f\_s, and Channel #y is to the right. The power level in Channel #x is shown by a solid orange line that is flat at -95 dBm/Hz until f\_s - w, then rises to -90 dBm/Hz at f\_s. The power level in Channel #y is shown by a solid blue line that is flat at -95 dBm/Hz until f\_s + w, then rises to -90 dBm/Hz at f\_s. The out-of-band power level for Channel #y is indicated by a dashed orange line at -90 dBm/Hz, and for Channel #x by a dashed blue line at -90 dBm/Hz. The text 'Channel #y out-of-band power level below bold threshold' is placed below the dashed orange line, and 'Channel #x out-of-band power level below light threshold' is placed below the dashed blue line. The x-axis is labeled 'frequency' and has markers for f\_s - w, f\_s, and f\_s + w. The y-axis is labeled 'P' and has markers for -90 dBm/Hz and -95 dBm/Hz. The figure code G.9972(10)\_F14-1 is shown in the bottom right corner.
+
+NOTE – The leakage signal level assumes that two nodes are not co-located and that there is some minimum attenuation between them. If this is not the case, lower leakage signal is recommended or additional filters should be added.
+
+Figure 14-1 – Leakage signal level
+
+### 14.1.1 Clock frequency tolerance
+
+Clock frequency tolerance shall be  $\pm 100$  ppm maximum.
+
+## 14.2 Signal detection
+
+The minimum ISP signal detection requirements are:
+
+- ISP signal shall be detected with 99% success in an additive white Gaussian noise (AWGN) with SNR higher or equal to 5 dB.
+- Probability of detecting an ISP signal with a wrong phase shall be lower than 1% in an AWGN with the SNR higher or equal to 0 dB.
+- Probability of falsely detecting an ISP signal when no signal is present (just noise) in an AWGN shall be lower than 1 detection every 5 seconds.
+
+For signal levels of  $-124$  dBm/Hz and above in  $-140$  dBm/Hz AWGN, the ISP signal detection error rate shall not exceed 1%. The measurement for the limit is made using a peak-hold detector with a resolution bandwidth 10 kHz (dBm/10 kHz) or 9 kHz (dBm/9 kHz).
+
+## 14.3 Zero-crossing detection
+
+The master node in each coexisting system shall have a zero-cross detector. Other nodes in the coexisting system may also have a zero-cross detector. The master node distributes information that can be used to determine the location of the ISP window to other nodes via the ISP\_IndicateState message. For slave nodes with zero-cross detector, vendors may decide whether to use the zero-cross detector or the information distributed by the master node or a combination of both.
+
+The zero-cross detector of the node shall detect the AC zero-cross with a tolerance lower than  $\pm 25$   $\mu\text{s}$  in 95% of the cases.
+
+NOTE – Additional filtering of the zero-cross point detected by the circuit is recommended.
+
+# Annex A
+
+## ITU-T G.996x coexistence management messages
+
+(This annex forms an integral part of this Recommendation.)
+
+## A.1 ITU-T G.996x coexistence management message parameters
+
+A description of the generic management messages required for coexistence is provided in clause 13. Each coexisting system maps these generic messages to its own messaging scheme. ITU-T G.996x implements these messages as ITU-T G.9961 management messages, with OPCODES listed in clause 8.10.1 of [ITU-T G.9961]. The OPCODE and ITU-T G.9961 management message name corresponding to each generic ISP management message are summarized in Table A.1.
+
+This clause provides the management message parameter lists (MMPLs) corresponding to each of these management messages. The messages described in this clause shall be used only by those systems that operate as specified in [ITU-T G.996x].
+
+**Table A.1 – Mapping of ISP generic messages to ITU-T G.9961 specific messages**
+
+| ISP generic message          |           | ITU-T G.9961 management message  |              |
+|------------------------------|-----------|----------------------------------|--------------|
+| Name                         | Reference | Name                             | OPCODE (hex) |
+| ISP_IndicateState            | 13.1.1    | ISP_IndicateState.ind            | 040          |
+| ISP_DetectionReport          | 13.1.2    | ISP_DetectionReport.ind          | 041          |
+| ISP_StartResync              | 13.2.1    | ISP_StartResync.req              | 042          |
+| ISP_ResyncFinished           | 13.2.2    | ISP_ResyncFinished.ind           | 043          |
+| ISP_ResyncDetected           | 13.2.3    | ISP_ResyncDetected.ind           | 044          |
+| ISP_DirectResyncTransmission | 13.2.4    | ISP_DirectResyncTransmission.req | 045          |
+
+### A.1.1 Format of ISP\_IndicateState.ind
+
+Message ISP\_IndicateState.ind is a management message that is transmitted by the domain master and provides coexistence network status, ISP operation mode and ISP sequence timing information.
+
+This message contains at least the elements as shown in Table A.2. The criteria used by the domain master for determining the value of the "ISP\_Suspend" sub-field are for further study.
+
+**Table A.2 – Format of the ISP\_IndicateState.ind message**
+
+| Field        | Octet | Bits  | Description                                                                                                                                                        |
+|--------------|-------|-------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Access state | 0     | [3:0] | Described in Table A.3                                                                                                                                             |
+| IHC1 state   |       | [4]   | Shall be set to 1 when an IHC1 domain is present in the current ISP sequence.<br>Shall be set to 0 when an IHC1 domain is not present in the current ISP sequence. |
+| IHC2 state   |       | [5]   | Shall be set to 1 when an IHC2 domain is present in the current ISP sequence.<br>Shall be set to 0 when an IHC2 domain is not present in the current ISP sequence. |
+
+**Table A.2 – Format of the ISP\_IndicateState.ind message**
+
+| Field              | Octet | Bits   | Description                                                                                                                                                                                                                                                                                                                                                                                                                              |
+|--------------------|-------|--------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| ISP_Suspend        |       | [7:6]  | This field shall be set to "00" to indicate that the node shall continue to perform all ISP operations as required.<br>This field shall be set to "01" to indicate that the node shall suspend transmission of ISP signals and shall periodically monitor for ISP signals.<br>This field shall be set to "10" to indicate that the node shall suspend all ISP signal transmission and detection.<br>The value "11" is reserved by ITU-T. |
+| Next SP counter    | 1     | [1:0]  | The value of the internal sync point counter of the domain master at the next ISP window occurrence for [ITU-T G.9961]                                                                                                                                                                                                                                                                                                                   |
+| Reserved           |       | [7:2]  | Reserved by ITU-T                                                                                                                                                                                                                                                                                                                                                                                                                        |
+| Next ZeroX counter | 2-5   | [31:0] | This is a 32-bit unsigned integer that indicates the zero-crossing point immediately before the next ISP window occurrence for ITU-T G.996x. It shall be based on the domain master's transmit clock with a resolution of 10 ns.<br>The start of the next ISP window = Next ZeroX Counter + (Next SP Counter * 2 * $T_o$ ) + $T_{off}$ .                                                                                                 |
+
+**Table A.3 – Values for the access state sub-field**
+
+| Value                                 | Description                                                                                  |
+|---------------------------------------|----------------------------------------------------------------------------------------------|
+| 0000 <sub>2</sub>                     | No access system detected                                                                    |
+| 0001 <sub>2</sub> – 0011 <sub>2</sub> | Reserved by ITU-T                                                                            |
+| 0100 <sub>2</sub>                     | Access system detected indicating TDM, partial bandwidth                                     |
+| 0110 <sub>2</sub>                     | Access system detected indicating TDM, full bandwidth                                        |
+| 0101 <sub>2</sub>                     | Access system detected indicating FDM, partial bandwidth                                     |
+| 0111 <sub>2</sub>                     | Access system detected indicating FDM, full bandwidth                                        |
+| 1000 <sub>2</sub>                     | Detect access system indicating FDM, partial bandwidth, but cannot support it                |
+| 1001 <sub>2</sub>                     | Detect access system indicating FDM, full bandwidth, but cannot support it                   |
+| 1010 <sub>2</sub>                     | Detect access system indicating FDM, partial bandwidth. Request interference level reduction |
+| 1011 <sub>2</sub>                     | Detect access system indicating FDM, full bandwidth. Request interference level reduction    |
+| 1100 <sub>2</sub> – 1111 <sub>2</sub> | Reserved by ITU-T                                                                            |
+
+### A.1.2 Format of ISP\_DetectionReport.ind
+
+The ISP\_DetectionReport.ind message is a unicast management message sourced by the node and is used for indicating the network status of the node. This message shall be sent by the node whenever there is a change in its network status. Other triggers of this message are for further study.
+
+ISP\_DetectionReport.ind message contains at least the elements shown in Table A.4.
+
+**Table A.4 – Format of the MMPL field of the ISP\_DetectionReport.ind message**
+
+| Field                           | Octet | Bits   | Description                                                                                                             |
+|---------------------------------|-------|--------|-------------------------------------------------------------------------------------------------------------------------|
+| Access state                    | 0     | [2:0]  | Described in Table A.5                                                                                                  |
+| IHC1 state                      |       | 3      | 1, when an IHC1 domain has been detected.<br>0, when no IHC1 domain has been detected.                                  |
+| IHC2 state                      |       | 4      | 1, when an IHC2 domain has been detected.<br>0, when no IHC2 domain has been detected.                                  |
+| Reserved                        |       | [7:5]  | Reserved by ITU-T                                                                                                       |
+| Number of out-of-sync sequences | 1     | [7:0]  | Number of detected out-of-sync ISP sequences (Also shows the number of elements of the out-of-sync sequence list field) |
+| Out-of-sync sequence list       | 2-3   | [15:0] | List of detected out-of-sync ISP sequences<br>Described in Table A.6                                                    |
+
+**Table A.5 – Values for the access state field**
+
+| Value            | Description                                              |
+|------------------|----------------------------------------------------------|
+| 000 <sub>2</sub> | No access system detected                                |
+| 100 <sub>2</sub> | Access system detected indicating TDM, partial bandwidth |
+| 110 <sub>2</sub> | Access system detected indicating TDM, full bandwidth    |
+| 101 <sub>2</sub> | Access system detected indicating FDM, partial bandwidth |
+| 111 <sub>2</sub> | Access system detected indicating FDM, full bandwidth    |
+| Others           | Reserved by ITU-T                                        |
+
+**Table A.6 – Format of an element of the out-of-sync sequence list sub-field**
+
+| Sub-field    | Octet | Bits  | Description                                                                                                              |
+|--------------|-------|-------|--------------------------------------------------------------------------------------------------------------------------|
+| ISP offset   | 0     | [7:0] | Offset of the out-of-sync ISP sequence from the current sync point in units of the number of sync points                 |
+| Access state | 1     | [2:0] | Described in Table A.5                                                                                                   |
+| IHC1 state   |       | 3     | 1, when an IHC1 domain has been detected.<br>0, when no IHC1 domain has been detected.                                   |
+| IHC2 state   |       | 4     | 1, when an IHC2 domain has been detected.<br>0, when no IHC2 domain has been detected.                                   |
+| IH-G state   |       | 5     | 1, when an ITU-T G.996x domain has been detected.<br>0, when no ITU-T G.996x domain has been detected.                   |
+| Resync flag  |       | 6     | 1, when resync ISP signals have been detected in this ISP sequence.<br>0, when no resync ISP signals have been detected. |
+| Reserved     |       | 7     | Reserved by ITU-T                                                                                                        |
+
+### A.1.3 Format of ISP\_StartResync.req
+
+The ISP\_StartResync.req message is a unicast/broadcast management message sourced by the domain master and shall be used to request the node to start the coexistence resynchronization process. The ISP\_StartResync.req message does not require a MMPL.
+
+### A.1.4 Format of ISP\_ResyncFinished.ind
+
+The ISP\_ResyncFinished.ind message is a unicast/broadcast management message sourced by the domain master and shall be used to indicate that the coexistence resynchronization sequence has been finished.
+
+The ISP\_ResyncFinished.ind message contains at least the elements shown in Table A.7.
+
+**Table A.7 – Format of the MMPL field of the ISP\_ResyncFinished.ind message**
+
+| Field                     | Octet | Bits   | Description                                                                                                          |
+|---------------------------|-------|--------|----------------------------------------------------------------------------------------------------------------------|
+| Number of re-sync signals | 0     | [7:0]  | Number of transmissions of resynchronization ISP signals to the sync points that were not selected.                  |
+| Access state              | 1     | [2:0]  | Described in Table A.5                                                                                               |
+| IHC1 state                |       | 3      | 1, when an IHC1 domain is working at the new sync point.<br>0, when no IHC1 domain is working at the new sync point. |
+| IHC2 state                |       | 4      | 1, when an IHC2 domain is working at the new sync point.<br>0, when no IHC2 domain is working at the new sync point. |
+| Reserved                  |       | 5      | Reserved by ITU-T                                                                                                    |
+| Next SP counter           |       | [7:6]  | Value of the internal sync point counter of the domain master at the next ISP window for ITU-T G.996x.               |
+| Next ZeroX counter        | 2-5   | [31:0] | Value of the internal zero-cross counter of the domain master at the next ISP window for ITU-T G.996x.               |
+
+### A.1.5 Format of ISP\_ResyncDetected.ind
+
+The ISP\_ResyncDetected.ind message is a unicast management message sourced by the node to the domain master and shall be used to indicate that the node has detected a coexistence resynchronization request. The ISP\_ResyncDetected.ind message does not require an MMPL.
+
+### A.1.6 Format of ISP\_DirectResyncTransmission.req
+
+The ISP\_DirectResyncTransmission.req message is a unicast/broadcast management message sourced by the domain master and shall be used to request the node to transmit coexistence resynchronization request ISP signals to out-of-sync domains.
+
+The ISP\_DirectResyncTransmission.req message contains at least the elements shown in Table A.8.
+
+**Table A.8 – Format of the MMPL field of the ISP\_DirectResyncTransmission.req message**
+
+| Field                            | Octet | Bits  | Description                                                                                                                                                                                                          |
+|----------------------------------|-------|-------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Number of re-sync signals        | 0     | [7:0] | Number of transmissions of resynchronization ISP signals.                                                                                                                                                            |
+| Number of sync points            | 1     | [7:0] | Number of sync points (N) at which it is required to transmit resynchronization ISP signals (this also shows the number of elements of the ISP offset list field).<br>Valid values of this field are 1, 2, ..., 143. |
+| ISP offset list for sync point 1 | 2     | [7:0] | List of sync points at which the node transmits resynchronization ISP signals.<br>The number N is equal to the value of the number of sync points field.                                                             |
+| ...                              | ...   | ...   | ...                                                                                                                                                                                                                  |
+| ISP offset list for sync point N | N+1   | [7:0] |                                                                                                                                                                                                                      |
+
+# Bibliography
+
+- [b-IEEE 1901] IEEE 1901-2010, *IEEE Standard for Broadband over Power Line Networks: Medium Access Control and Physical Layer Specifications*.
+
+
+
+
+
+## SERIES OF ITU-T RECOMMENDATIONS
+
+|                 |                                                                                             |
+|-----------------|---------------------------------------------------------------------------------------------|
+| Series A        | Organization of the work of ITU-T                                                           |
+| Series D        | General tariff principles                                                                   |
+| Series E        | Overall network operation, telephone service, service operation and human factors           |
+| Series F        | Non-telephone telecommunication services                                                    |
+| <b>Series G</b> | <b>Transmission systems and media, digital systems and networks</b>                         |
+| Series H        | Audiovisual and multimedia systems                                                          |
+| Series I        | Integrated services digital network                                                         |
+| Series J        | Cable networks and transmission of television, sound programme and other multimedia signals |
+| Series K        | Protection against interference                                                             |
+| Series L        | Construction, installation and protection of cables and other elements of outside plant     |
+| Series M        | Telecommunication management, including TMN and network maintenance                         |
+| Series N        | Maintenance: international sound programme and television transmission circuits             |
+| Series O        | Specifications of measuring equipment                                                       |
+| Series P        | Terminals and subjective and objective assessment methods                                   |
+| Series Q        | Switching and signalling                                                                    |
+| Series R        | Telegraph transmission                                                                      |
+| Series S        | Telegraph services terminal equipment                                                       |
+| Series T        | Terminals for telematic services                                                            |
+| Series U        | Telegraph switching                                                                         |
+| Series V        | Data communication over the telephone network                                               |
+| Series X        | Data networks, open system communications and security                                      |
+| Series Y        | Global information infrastructure, Internet protocol aspects and next-generation networks   |
+| Series Z        | Languages and general software aspects for telecommunication systems                        |
\ No newline at end of file
diff --git a/marked/T/T-REC-T.0-199607-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/T/T-REC-T.0-199607-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..ad5d76b9a121494c1d902c7aba2d879882fc06b1
--- /dev/null
+++ b/marked/T/T-REC-T.0-199607-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:0d98881bf8bcbb487391f6ddb2e8579a59c837cb3c6cf82355a4898f188b751c
+size 8272
diff --git a/marked/T/T-REC-T.0-199607-I_PDF-E/raw.md b/marked/T/T-REC-T.0-199607-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..215bd770dede400af1e3369f91c3783a2594bb6f
--- /dev/null
+++ b/marked/T/T-REC-T.0-199607-I_PDF-E/raw.md
@@ -0,0 +1,152 @@
+
+
+![ITU logo: a globe with the letters ITU and a lightning bolt symbol.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg)
+
+ITU logo: a globe with the letters ITU and a lightning bolt symbol.
+
+INTERNATIONAL TELECOMMUNICATION UNION
+
+**ITU-T**
+
+TELECOMMUNICATION  
+STANDARDIZATION SECTOR  
+OF ITU
+
+**T.0**
+
+(07/96)
+
+**TERMINALS FOR TELEMATIC SERVICES**
+
+---
+
+**CLASSIFICATION OF FACSIMILE TERMINALS  
+FOR DOCUMENT TRANSMISSION OVER  
+THE PUBLIC NETWORKS**
+
+**ITU-T Recommendation T.0**
+
+(Previously "CCITT Recommendation")
+
+---
+
+# FOREWORD
+
+The ITU-T (Telecommunication Standardization Sector) is a permanent organ of the International Telecommunication Union (ITU). The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis.
+
+The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics.
+
+The approval of Recommendations by the Members of the ITU-T is covered by the procedure laid down in WTSC Resolution No. 1 (Helsinki, March 1-12, 1993).
+
+ITU-T Recommendation T.0, was revised by ITU-T Study Group 8 (1993-1996) and was approved under the WTSC Resolution No. 1 procedure on the 3rd of July 1996.
+
+# --- NOTE
+
+In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+© ITU 1996
+
+All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU.
+
+# **SUMMARY**
+
+Recommendations T.2 and T.3 define Group 1 and Group 2 facsimile terminals respectively; such stand-alone terminals have not been manufactured for many years and Group 3 facsimile terminals are the only type being used on the GSTN.
+
+In recognition of this market situation, Study Group 8 has agreed to delete references to Groups 1 and 2 in Recommendations T.4 and T.30.
+
+In order to be consistent and to minimize the possibility of any confusion, it is proposed that this Recommendation be amended to delete references to Group 1 and Group 2 terminals and also to use consistent terminology.
+
+
+
+# CLASSIFICATION OF FACSIMILE TERMINALS FOR DOCUMENT TRANSMISSION OVER THE PUBLIC NETWORKS
+
+*(Geneva, 1976; amended at Geneva, 1980;  
+Malaga-Torremolinos, 1984, Melbourne, 1988 and in 1996)*
+
+**1** For document facsimile transmission by international communications carried on the public networks there is a need for providing sufficient operating speeds to meet users' requirements.
+
+**2** Users' requirements may best be served at the present time by classifying the following four basic categories of document facsimile terminal.
+
+## 2.1 Terminals for use over the public telephone network
+
+Group 3 (see Note)
+
+A terminal which incorporates means for reducing the redundant information in the document signal prior to the modulation process and which can achieve a transmission time less than 1 minute for a typical typescript document of ISO A4 size via a telephone-type circuit. The terminal may incorporate bandwidth compression of the line signal.
+
+NOTE – This terminal has been standardized in Recommendation T.4.
+
+## 2.2 Terminals for use over the public data networks
+
+Group 4 (see Note)
+
+A terminal which incorporates means for reducing the redundant information in the document signal prior to transmission mainly via Public Data Networks (PDNs). The apparatus will utilize procedures applicable to the PDN and will assure an essentially error-free reception of the document.
+
+NOTE – This terminal has been standardized in Recommendations T.6, T.503, T.521 and T.563.
+
+**3** The users will choose among these terminals, in accordance with their needs and the facilities afforded by the connection and the network.
+
+**4** Procedures for Group 3 document facsimile transmission in the public switched telephone network should be in accordance with Recommendation T.30.
+
+**5** Procedures for Group 4 document facsimile transmission should be in accordance with Recommendations T.62, T.62 *bis*, T.70 and T.90.
+
+**6** Annex A contains definitions for terms used in the T-Series Recommendations applicable to facsimile terminals.
+
+# Annex A
+
+## Definitions for terms used in the T-Series Recommendations applicable to facsimile terminals
+
+(This annex forms an integral part of this Recommendation)
+
+The following definitions apply to Recommendations T.1 and T.4:
+
+**A.1 dead sector** (Recommendation T.1): In drum terminals, that portion of the drum surface the scanning time of which cannot be used for picture signal transmission.
+
+**A.2 drum factor** (Recommendation T.1): In drum terminals, the ratio of the usable scanning length of the drum to its diameter.
+
+**A.3 facsimile** (Series T): The process of scanning a document (page), converting the image scanned into electrical signals for transmission to a remote receiver and the conversion of the received signals to produce a copy of the image originally scanned.
+
+**A.4 factor of cooperation** (Recommendation T.1): The product of the total scanning line length and the scanning density.
+
+**A.5 flat-bed transmitter** (Recommendation T.1): A terminal in which the original document is placed flat and scanned line by line.
+
+**A.6 index of cooperation** (Recommendation T.1): Quotient of the factor of cooperation divided by the quantity  $\pi$ . In the case of a drum terminal, the index of cooperation is also equal to the product of the drum diameter and the scanning density.
+
+**A.7 judder, longitudinal** (Recommendation T.1): Effect due to the irregular rotation of the drum or helix causing, on the reproduced picture, slight waviness or breaks in lines that are regular on the original document.
+
+**A.8 judder, transverse** (Recommendation T.1): Effect due to irregularity of the scanning pitch resulting in concurrent overlapping and underlapping in the reproduced picture.
+
+**A.9 nominal black (white)** (Recommendation T.1): Level or frequency of the signal corresponding to a pure black (white).
+
+**A.10 pel** (Series T): A contraction of “picture element”.
+
+**A.11 phasing** (Recommendation T.1): At the receiver, ensuring the exact coincidence of the midpoint of the scanning field, with the corresponding point at the transmitter so as to ensure the correct positioning of the picture on the recording medium.
+
+**A.12 phasing signal** (Recommendation T.1): A signal sent by the transmitter for phasing purposes.
+
+NOTE – Phasing is known as “phase white (black)” if the phasing signal is a black (white) signal of which a short interruption corresponding to the white (black) is sent during the lost time.
+
+**A.13 phototelegraphy** (Recommendation T.1): Method of reception of facsimile telegraphy which is chiefly intended for the reproduction of graded tonal densities and in which a photographic process is used at the receiver.
+
+**A.14 picture element** (Recommendation T.4):
+
+a) *at transmission:*
+
+The part of the area of the original document which coincides with the scanning spot at a given instant and which is of one intensity only, with no distinction of the details that may be included.
+
+b) *at reception:*
+
+The area of the finest detail that can be effectively reproduced on the recording medium.
+
+**A.15 reproduction ratio** (Recommendation T.1): The ratio of the linear dimensions of the reproduced document to the corresponding dimensions of the original document.
+
+**A.16 resolution** (Series T): A measure of the capability for delineating picture detail. In Group 3 and Group 4 facsimile transmission resolution is expressed as picture elements or pels per mm (horizontal resolution) and lines per mm (vertical resolution).
+
+**A.17 scanning density** (Recommendation T.1): Number of scanning pitches per unit length.
+
+**A.18 scanning line** (Recommendation T.1): The area explored by the scanning spot in one sweep from one side to the other of the scanning field.
+
+**A.19 scanning pitch** (Recommendation T.1): The distance between the corresponding edges of two consecutive scanning lines.
+
+**A.20 skew** (Recommendation T.4): A defect in reproduction in which lines that should be at right-angles to the scanning direction are inclined to it, owing to a difference between the scanning speeds at transmission and reception.
+
+**A.21 synchronization** (Recommendation T.1): The establishment of equal scanning line frequencies at the transmitter and receiver.
\ No newline at end of file
diff --git a/marked/T/T-REC-T.1-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/T/T-REC-T.1-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..66412856f54ae0b24854202e8f031f6a04b88ee0
--- /dev/null
+++ b/marked/T/T-REC-T.1-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:a7cafe25d563af62a326eb0e9930129524893e0fb16cb431aacd25f8ed54ed31
+size 7392
diff --git a/marked/T/T-REC-T.10-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/T/T-REC-T.10-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..279064eaf67206140dfb1d2f63a0d46b863c0837
--- /dev/null
+++ b/marked/T/T-REC-T.10-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:56a9721b3a934a0bd2abbff0958ea95f896b5506c4e2140a46623d3e5ea5f32e
+size 7511
diff --git a/marked/T/T-REC-T.100-198811-I_PDF-E/raw.md b/marked/T/T-REC-T.100-198811-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..956579997cb9d80df8e1161ba3ac3fb775fedf37
--- /dev/null
+++ b/marked/T/T-REC-T.100-198811-I_PDF-E/raw.md
@@ -0,0 +1,1721 @@
+
+
+![ITU logo: a globe with the letters ITU and a lightning bolt.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg)
+
+The logo of the International Telecommunication Union (ITU) is located in the top left corner. It consists of a stylized globe with the letters 'ITU' superimposed on it. A lightning bolt is depicted striking the globe from the top left.
+
+ITU logo: a globe with the letters ITU and a lightning bolt.
+
+INTERNATIONAL TELECOMMUNICATION UNION
+
+**ITU-T**
+
+TELECOMMUNICATION  
+STANDARDIZATION SECTOR  
+OF ITU
+
+**T.100**
+
+**TERMINAL EQUIPMENT AND PROTOCOLS FOR  
+TELEMATIC SERVICES**
+
+---
+
+**INTERNATIONAL INFORMATION EXCHANGE  
+FOR INTERACTIVE VIDEOTEX**
+
+**ITU-T Recommendation T.100**
+
+(Extract from the *Blue Book*)
+
+---
+
+# NOTES
+
+1 ITU-T Recommendation T.100 was published in Fascicle VII.5 of the *Blue Book*. This file is an extract from the *Blue Book*. While the presentation and layout of the text might be slightly different from the *Blue Book* version, the contents of the file are identical to the *Blue Book* version and copyright conditions remain unchanged (see below).
+
+2 In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+# Recommendation T.100
+
+# INTERNATIONAL INFORMATION EXCHANGE FOR INTERACTIVE VIDEOTEX
+
+(Geneva, 1980; amended at Malaga-Torremolinos, 1984)
+
+# CONTENTS
+
+# Preamble
+
+- 1 Purpose and scope of this Recommendation
+- 2 General Videotex coding structure
+- 3 Common features
+- 4 Representation of alphanumeric characters in a Videotex system
+- 5 Alphamosaic option
+- 6 Alphageometric option
+- 7 Dynamically redefinable character sets (DRCS) option
+- 8 Alphaphotographic option
+- 9 Service enhancements
+- 10 Line and end-to-end protocols
+- 11 Interworking with other services
+
+*Annex A* – The extension scheme of ISO 2022
+
+*Annex B* – Repertoire of graphic characters
+
+# **Preamble**
+
+The CCITT,
+
+*considering*
+
+(a) that there is increasing interest in public network-based new interactive information retrieval services using domestic television receivers suitably supplemented, or other apparatus, as terminal equipment;
+
+(b) that the CCIR is studying standards for broadcast *Teletext* services for general reception and has expressed a view that it is desirable that terminal equipment compatibility should exist between broadcast Teletext systems for general reception and public network-based data bank systems;
+
+(c) that such services should be provided over public networks in accordance with CCITT Recommendations and may be required to operate as an international service;
+
+(d) that such services may interwork with terminals provided for text communication services (Teletex for example);
+
+(e) that some Administrations intend to have an early introduction of, or have already introduced, public interactive *Videotex* services;
+
+*unanimously recommends*
+
+that the following technical provisions be applied for international information exchange for interactive Videotex service.
+
+# **1 Purpose and scope of the Recommendation**
+
+## *1.1 Purpose*
+
+### 1.1.1 The purpose of this Recommendation is:
+
+- a) to facilitate an orderly introduction of early Videotex services (including the continuation of existing services, with a clear identification of potential enhancements) that need to be considered in future developments;
+- b) to identify parameters needed to design Videotex terminals; and
+- c) to provide technical recommendations desirable for potential interworking of other services with Videotex services.
+
+## *1.2 Scope*
+
+1.2.1 This Recommendation describes the characteristics of coded information that is exchanged between countries participating in the international interactive Videotex service (as described in Recommendation F.300) and defines the display features corresponding to its various elements.
+
+1.2.2 Videotex systems are text communication systems having in addition the capability of a given level of pictorial representation and a repertoire of display attributes. The text and the pictures obtained are intended to be displayed using the current television (TV) raster standards of the different countries.
+
+1.2.3 Different options are offered as a choice for the Administrations to implement their national services. Substantial degrees of compatibility exist between these options, but some transcoding may be necessary to facilitate interworking.
+
+### 1.2.4 For the international service, four different options for representing pictorial information have been recognized:
+
+- a) mosaic character sets;
+- b) geometric system;
+- c) dynamically redefinable character sets;
+- d) photographic representation.
+
+These options are not mutually exclusive and it is possible that systems may develop using two or more options.
+
+### 1.2.5 For international interworking, two categories of TV systems have to be considered:
+
+- a) systems having a vertical resolution of 525 lines per TV frame at 30 TV frames per second;
+- b) systems having a vertical resolution of 625 lines per TV frame at 25 TV frames per second.
+
+1.2.6 Interworking problems at the pictorial level between countries having different recognized pictorial systems and/or television standards require further study.
+
+### 1.2.7 This Recommendation is structured as follows:
+
+§§ 1, 2 and 3 deal with the features common to all the options;
+
+§ 4 deals with the coding of characters of the Videotex alphanumeric repertoire defined in Annex B;
+
+§ 5 deals with the alphamosaic option;
+
+§ 6 deals with the alphageometric option;
+
+§ 7 deals with the dynamically redefinable character sets (DRCS) option;
+
+§ 8 deals with the alphaphotographic option;
+
+- § 9 deals with future enhancements and identifies features requiring further study such as: audio, downloaded software, motion, etc.;
+- § 10 deals with line and end-to-end protocols;
+- § 11 deals with interworking with other services.
+
+Some of these parts have not been completed, and therefore contain guidelines towards future extensions rather than a complete technical specification.
+
+# **2 General Videotex coding structure**
+
+## *2.1 General*
+
+2.1.1 The basis of the coding structure for the Videotex service is Recommendation T.50 and the international standards ISO 2022, ISO 6937 for the 7-bit environment. Specifically, the shift-in code SI (0/15) invokes the G0 set for alphanumeric text mode of operation, and the shift-out code SO (0/14) invokes the G1 set, for all the models (see Annex A). The use of the 8-bit coding scheme is for further study.
+
+2.1.2 In addition to the provisions made by ISO 2022, the transmission of alphabetic characters having diacritical signs is effected by transmitting the code representing the diacritical mark together with the code of the basic alphabetic character.
+
+2.1.3 The different options are designated (and invoked) by specific escape sequences.
+
+## *2.2 Designation and invocation in the context of the alphamosaic option*
+
+2.2.1 Two different modes for the alphamosaic option have been identified. They differ in their display control sets. These control sets are designated as the C1 set by the following control sequences: ESC 2/2 4/0 for the serial mode and ESC 2/2 4/1 for the parallel mode, as assigned by ISO. Individual controls are represented by: ESC F, sequences.
+
+2.2.2 The mosaic graphics set is designated (in the parallel mode) as the G1 set by an escape sequence ESC 2/9 6/3 as allocated by ISO.
+
+## *2.3 Designation and invocation in the context of the alphageometric option*
+
+2.3.1 The alphageometric coding scheme is to be designated and invoked by the escape sequence ESC 2/5 (5/x) in accordance with § 5.3.8 of ISO 2022 standard. This designates and invokes a complete code with interpretation as follows.
+
+2.3.2 All the meanings and interpretation of Recommendation T.50 and ISO 2022 remain the same, including C0, G0 and G2 with the exception of SI and SO. The codes of the G1 set and their meanings and interpretations are as described in § 6.
+
+2.3.3 The designation and invocation of the complete code by the sequence ESC 2/5 (5/x) is to be terminated only by ESC 2/9 (F) or ESC 2/13 (F), designating a normal G1 set.
+
+## *2.4 Designation and invocation in the context of DRCS*
+
+2.4.1 A DRCS is a set of characters whose shapes are sent from the service and down-loaded via the line. It may be used to represent alphabetic characters, special symbols, or picture element symbols for constructing fine graphics. Once loaded, the DRCS are regarded as members of a library that can be designated by appropriate ESC sequences as G0, G1, G2, G3 sets. One scheme is described in § 7 in the context of a general architecture.
+
+## *2.5 Designation and invocation in the context of the alphaphotographic option*
+
+(For further study.)
+
+# 3 Common features
+
+## 3.1 General
+
+3.1.1 The features pertaining to individual systems will be described in the corresponding paragraphs. The common features comprise common display features and common control functions.
+
+## 3.2 Common display features
+
+3.2.1 The *defined display area* is that rectangular position of the display in which all text and pictorial images may be presented (see Figure 1/T.100).
+
+3.2.2 The *border area* is that part of the visible display of a terminal that is outside the defined display area (see Figure 1/T.100).
+
+![Diagram of a terminal display showing the visible display area, defined display area, and border area.](1be8e9cad5f38fa47bdb81e549a3bec9_img.jpg)
+
+The diagram illustrates the layout of a terminal display. It features a large rounded rectangle labeled 'Visible display' with an arrow pointing to it from the left. Inside this rectangle is a smaller rectangle labeled 'Defined display area' with an arrow pointing to it from the right. The space between the outer and inner rectangles is labeled 'Border area' with an arrow pointing to it from the right. Below the diagram, the text 'CCITT-44080' is printed.
+
+Diagram of a terminal display showing the visible display area, defined display area, and border area.
+
+FIGURE 1/T.100  
+Common display features
+
+## 3.3 Common format effector and code extension control functions
+
+### 3.3.1 General
+
+3.3.1.1 The format effector control functions described for the Videotex system permit the active drawing position to be moved on the visible display area. These are taken from the C0 set (see Figure 2/T.100) together with the *Space* character 2/0. In order to permit interworking between Videotex and other text communications services, these control functions have functional compatibility to the extent possible with the basic C0 control set utilized by these other services.
+
+### 3.3.2 Format effector controls
+
+3.3.2.1 Some of the format effector control functions may be used from terminal to computer with different meanings.
+
+#### 3.3.2.2 Active position backward (APB)
+
+This control function causes the active position to be moved one character position backwards on the same row. APB on the first character position on the row moves the active position to the last character position of the preceding row. APB on the first character position on the first row moves the active position to the last character position of the last row.
+
+#### 3.3.2.3 *Active position forward (APF)*
+
+This function causes the active position to be moved to the next character position forward on the same row. At the last position on the row, this control moves the active position to the first character position on the following row. APF on the last character position of the last row moves the active position to the first character position of the first row.
+
+#### 3.3.2.4 *Active position down (APD)*
+
+This function causes the active position to be moved to the equivalent character position on the following row. APD on the last row moves the active position of the equivalent character position of the first row of the display frame or causes a roll-up to be made.
+
+|                |                |                |                |    |                |     |   |   |   |   |   |   |   |
+|----------------|----------------|----------------|----------------|----|----------------|-----|---|---|---|---|---|---|---|
+|                |                |                |                |    | b <sub>7</sub> | 0   | 0 | 0 | 0 | 1 | 1 | 1 | 1 |
+|                |                |                |                |    | b <sub>6</sub> | 0   | 0 | 1 | 1 | 0 | 0 | 1 | 1 |
+|                |                |                |                |    | b <sub>5</sub> | 0   | 1 | 0 | 1 | 0 | 1 | 0 | 1 |
+|                |                |                |                |    |                | 0   | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
+| b <sub>4</sub> | b <sub>3</sub> | b <sub>2</sub> | b <sub>1</sub> |    |                |     |   |   |   |   |   |   |   |
+| 0              | 0              | 0              | 0              | 0  | NUL            | ②   |   |   |   |   |   |   |   |
+| 0              | 0              | 0              | 1              | 1  | ②              | ③   |   |   |   |   |   |   |   |
+| 0              | 0              | 1              | 0              | 2  | ②              | ③   |   |   |   |   |   |   |   |
+| 0              | 0              | 1              | 1              | 3  | ②              | ③   |   |   |   |   |   |   |   |
+| 0              | 1              | 0              | 0              | 4  | ②              | ③   |   |   |   |   |   |   |   |
+| 0              | 1              | 0              | 1              | 5  | ENQ            | ②   |   |   |   |   |   |   |   |
+| 0              | 1              | 1              | 0              | 6  | ②              | ②   |   |   |   |   |   |   |   |
+| 0              | 1              | 1              | 1              | 7  | ①              | ②   |   |   |   |   |   |   |   |
+| 1              | 0              | 0              | 0              | 8  | APB            | CAN |   |   |   |   |   |   |   |
+| 1              | 0              | 0              | 1              | 9  | APF            | SS2 |   |   |   |   |   |   |   |
+| 1              | 0              | 1              | 0              | 10 | APD            | ①   |   |   |   |   |   |   |   |
+| 1              | 0              | 1              | 1              | 11 | APU            | ESC |   |   |   |   |   |   |   |
+| 1              | 1              | 0              | 0              | 12 | CS             | ①   |   |   |   |   |   |   |   |
+| 1              | 1              | 0              | 1              | 13 | APR            | SS3 |   |   |   |   |   |   |   |
+| 1              | 1              | 1              | 0              | 14 | SO             | ③   |   |   |   |   |   |   |   |
+| 1              | 1              | 1              | 1              | 15 | SI             | ③   |   |   |   |   |   |   |   |
+
+CCITT-44090
+
+*Note 1* — Reserved for future study.
+
+*Note 2* — Reserved for transmission control characters. Their use in Videotex is for further study.
+
+*Note 3* — The definitions of these control functions are given in the relevant options.
+
+*Note 4* — As in all the code tables in this Recommendation, the shaded positions do not belong to the character set described.
+
+FIGURE 2/T.100
+
+**The primary set of control functions for international interactive Videotex**
+
+#### 3.3.2.5 *Active position up (APU)*
+
+This function causes the active position to be moved to the equivalent character position on the preceding row. APU on the first row moves the active position to the equivalent character position on the last row of the same display frame.
+
+#### 3.3.2.6 *Clear screen (CS)*
+
+This function causes the screen to be cleared and causes the active position to be moved to the first character position on the first row.
+
+#### 3.3.2.7 *Active position return (APR)*
+
+This function causes the active position to be moved to the first character position of the same row.
+
+#### 3.3.2.8 *Space (SP)*
+
+A control function that causes the active position to be moved one character width forward on the same row. It is also regarded as a graphic character with no foreground. In those systems that define an explicit background, the space copies the background colour into the active position and moves the active position one character width forward. If used in conjunction with the inversion attribute it copies the foreground colour into the active position and moves the active position one character width forward.
+
+#### 3.3.2.9 *Cancel (CAN)*
+
+A control function that fills all the character positions of the row, after the active position, with spaces and returns the active position to its original value.
+
+### 3.3.3 *Code extension control functions*
+
+3.3.3.1 Code extension control functions are used to expand the capability of the 7-bit code beyond 128 different characters or functions. Code extension functions alter the meaning of a number of characters following them.
+
+#### 3.3.3.2 *Escape (ESC)*
+
+A control character that is used to provide additional control functions other than transmission control functions and that alters the meaning of a limited number of contiguously following bit combinations in the manner specified in Recommendation T.51.
+
+#### 3.3.3.3 *Control sequence introducer (CSI)*
+
+A code extension control function that is used to provide coded representations for additional control functions, in particular for control functions with parameters such as presentation control functions.
+
+#### 3.3.3.4 *Shift-out (SO)*
+
+A control character that is used in conjunction with the *Shift-in* character to extend the graphic character set of the code and that alters the meaning of the bit combinations of columns 2-7 of the code table, until the occurrence of the *shift-in* character, except that the meaning of the bit combinations corresponding to the *space* character and the *delete* character (positions 2/0 and 7/15) are unaffected.
+
+#### 3.3.3.5 *Shift-in (SI)*
+
+A control character, used in conjunction with the *shift-out* character, that reinstates the former meanings of the bit combinations of columns 2-7 of the code table.
+
+#### 3.3.3.6 *Single shift (SS2)*
+
+This character alters the meaning of the single-bit combination following it. That bit combination must be one of those from columns 2-7 except 2/0 and 7/15. The meaning of the bit combination concerned is derived from an appropriately designated G2 graphic set.
+
+#### 3.3.3.7 *Single shift (SS3)*
+
+This character alters the meaning of the single-bit combination following it. That bit combination must be one of those from columns 2-7 except 2/0 and 7/15. The meaning of the bit combination concerned is derived from an appropriately designated G3 graphic set.
+
+## 3.4 *Miscellaneous*
+
+### 3.4.1 *Null (NUL)*
+
+This function may occur in non-transparent modes in the received bit stream at the terminal. It shall be regarded as a time filler and discarded.
+
+### 3.4.2 *Enquiry (ENQ)*
+
+A control character used as a request for a response from a remote station, which response may include station identification and/or station status.
+
+## 3.5 *Coding of control functions*
+
+3.5.1 A proposed coding of the control functions described is shown in Figure 2/T.100 as a C0 set, except for CSI which is coded in the C1 set.
+
+# 4 **Representation of alphanumeric characters in a Videotex system**
+
+## 4.1 *General*
+
+4.1.1 The repertoire for the Latin alphabet is shown in Annex B. The repertoire is derived from ISO 6937. Terminals capable of displaying a subset of the Videotex repertoire shall be permitted.
+
+4.1.2 Character repertoires for non-latin based languages can be accommodated in a similar manner to the latin alphabet. (For further study.)
+
+## 4.2 *Coding*
+
+4.2.1 Section 4.2 describes the coding of characters the shape of which are stored in the terminal. Some languages require that consecutive letters or diacritical marks will be joined and that no space appear between the characters. When an intersymbol space is required, it will be part of the character description.
+
+4.2.2 The code tables are shown in Figures 3/T.100 and 4/T.100. The code combinations representing characters not included in the Videotex repertoire shall not be transmitted.
+
+4.2.3 All the permitted combinations may be expected in the international exchange of information between two national services. It is the responsibility of Administrations to decide whether this exchange is a direct terminal to database operation or has to be performed through a gateway. See Recommendation F.300.
+
+4.2.4 The graphic characters from columns 2, 3, 5, 6 and 7 of the supplementary set are invoked one at a time by SS2.
+
+4.2.5 A character with a diacritical mark is transmitted by the sequence SS2, a character from column 4 from the supplementary set, and the appropriate character from the primary set. The diacritical marks are non-spacing.
+
+4.2.6 The ISO registration of graphics character sets will indicate any special features such as their use in conjunction with other graphic character sets or non-spacing characters, etc.
+
+4.2.7 For languages based on other than the Latin alphabet further study is required.
+
+# 5 **Alphamosaic option**
+
+## 5.1 *General*
+
+5.1.1 In the alphamosaic option, the display frame is composed of defined character positions which may be occupied by any of the characters of the repertoire. The repertoire is composed of the alphanumeric repertoire and a mosaic repertoire. The mosaic repertoire is formed by dividing the character space into a matrix of  $2 \times 3$  elements. There are 63 different combinations of these elements.
+
+|                |                |                |                |    |                |   |   |   |   |   |   |   |   |
+|----------------|----------------|----------------|----------------|----|----------------|---|---|---|---|---|---|---|---|
+|                |                |                |                |    | b <sub>7</sub> | 0 | 0 | 0 | 0 | 1 | 1 | 1 | 1 |
+|                |                |                |                |    | b <sub>6</sub> | 0 | 0 | 1 | 1 | 0 | 0 | 1 | 1 |
+|                |                |                |                |    | b <sub>5</sub> | 0 | 1 | 0 | 1 | 0 | 1 | 0 | 1 |
+|                |                |                |                |    |                | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
+| b <sub>4</sub> | b <sub>3</sub> | b <sub>2</sub> | b <sub>1</sub> |    |                |   |   |   |   |   |   |   |   |
+| 0              | 0              | 0              | 0              | 0  |                |   |   |   | 0 | à | P |   | p |
+| 0              | 0              | 0              | 1              | 1  |                |   |   | ! | 1 | A | Q | a | q |
+| 0              | 0              | 1              | 0              | 2  |                |   |   | " | 2 | B | R | b | r |
+| 0              | 0              | 1              | 1              | 3  |                |   |   |   | 3 | C | S | c | s |
+| 0              | 1              | 0              | 0              | 4  |                |   |   |   | 4 | D | T | d | t |
+| 0              | 1              | 0              | 1              | 5  |                |   |   | % | 5 | E | U | e | u |
+| 0              | 1              | 1              | 0              | 6  |                |   |   | & | 6 | F | V | f | v |
+| 0              | 1              | 1              | 1              | 7  |                |   |   | ' | 7 | G | W | g | w |
+| 1              | 0              | 0              | 0              | 8  |                |   |   | ( | 8 | H | X | h | x |
+| 1              | 0              | 0              | 1              | 9  |                |   |   | ) | 9 | I | Y | i | y |
+| 1              | 0              | 1              | 0              | 10 |                |   |   | * | : | J | Z | j | z |
+| 1              | 0              | 1              | 1              | 11 |                |   |   | + | ; | K |   | k |   |
+| 1              | 1              | 0              | 0              | 12 |                |   |   | , | < | L |   | l | l |
+| 1              | 1              | 0              | 1              | 13 |                |   |   | - | = | M |   | m |   |
+| 1              | 1              | 1              | 0              | 14 |                |   |   | · | > | N |   | n |   |
+| 1              | 1              | 1              | 1              | 15 |                |   |   | / | ? | O | ⓪ | o |   |
+
+CCITT-44100
+
+- ① Position 5/15 can be displayed as "low line", —, or as "number sign" #, to represent the terminator function required for some existing Videotex services.
+
+FIGURE 3/T.100
+
+The primary set of graphic characters for international interactive Videotex
+
+|                |                |                |                |    |                |   |   |    |    |   |   |    |    |
+|----------------|----------------|----------------|----------------|----|----------------|---|---|----|----|---|---|----|----|
+|                |                |                |                |    | b <sub>7</sub> | 0 | 0 | 0  | 0  | 1 | 1 | 1  | 1  |
+|                |                |                |                |    | b <sub>6</sub> | 0 | 0 | 1  | 1  | 0 | 0 | 1  | 1  |
+|                |                |                |                |    | b <sub>5</sub> | 0 | 1 | 0  | 1  | 0 | 1 | 0  | 1  |
+|                |                |                |                |    |                | 0 | 1 | 2  | 3  | 4 | 5 | 6  | 7  |
+| b <sub>4</sub> | b <sub>3</sub> | b <sub>2</sub> | b <sub>1</sub> |    | 0              |   |   |    | °  |   | - | Ω  | κ  |
+| 0              | 0              | 0              | 0              | 0  | 1              |   |   | i  | ±  | ` |   | Æ  | æ  |
+| 0              | 0              | 1              | 0              | 2  |                |   |   | ¢  | ²  | ´ |   | Ð  | ð  |
+| 0              | 0              | 1              | 1              | 3  |                |   |   | £  | ³  | ^ |   | ǎ  | ǎ  |
+| 0              | 1              | 0              | 0              | 4  |                |   |   | \$ | x  | ~ |   | Ĥ  | ĥ  |
+| 0              | 1              | 0              | 1              | 5  |                |   |   | ¥  | μ  | - |   |    | ı  |
+| 0              | 1              | 1              | 0              | 6  |                |   |   | #  | ¶  | ˘ |   | IJ | ij |
+| 0              | 1              | 1              | 1              | 7  |                |   |   | §  | •  | • |   | Ł  | ł  |
+| 1              | 0              | 0              | 0              | 8  |                |   |   | ¤  | ÷  | ¨ |   | Ł  | Ł  |
+| 1              | 0              | 0              | 1              | 9  |                |   |   | ‘  | ’  |   |   | Ø  | ø  |
+| 1              | 0              | 1              | 0              | 10 |                |   |   | “  | ”  | ° |   | Œ  | œ  |
+| 1              | 0              | 1              | 1              | 11 |                |   |   | << | >> | ¸ |   | ◊  | β  |
+| 1              | 1              | 0              | 0              | 12 |                |   |   | ←  | ¼  |   |   | þ  | þ  |
+| 1              | 1              | 0              | 1              | 13 |                |   |   | ↑  | ½  | " |   | ƒ  | £  |
+| 1              | 1              | 1              | 0              | 14 |                |   |   | →  | ¾  | ¸ |   | ŋ  | ŋ  |
+| 1              | 1              | 1              | 1              | 15 |                |   |   | ↓  | ¿  | ˘ |   | ’n |    |
+
+CCITT-44111
+
+FIGURE 4/T.100
+
+The supplementary set of graphic characters for international interactive Videotex
+
+5.1.2 Two modes have been identified, which are known as *serial* and *parallel* modes respectively. The two modes are distinguished by their display control sets which are coded in C1 sets, designated and represented by ESC F<sub>e</sub> sequences as described in § 2.2.1.
+
+5.1.3 The two modes have common features and specific features described in §§ 5.2 to 5.4 below.
+
+## 5.2 Common control functions
+
+### 5.2.1 General functions
+
+The *active position home (APH)*
+
+This function causes the active position to be moved to the first position of the first row. Its coded representation is 1/14 in Figure 2/T.100.
+
+### 5.2.2 Device control functions
+
+The following device control functions have been defined.
+
+#### 5.2.2.1 Definitions
+
+##### **cursor on (CON)**
+
+*F: curseur en marche (CON)*
+
+*S: cursor activo (CON)*
+
+The cursor on (CON) causes the active position to be visualized as a marker.
+
+##### **cursor off (COF)**
+
+*F: curseur arrêté (COF)*
+
+*S: cursor inactivo (COF)*
+
+The cursor off (COF) causes the active position to be displayed in the same way as other character positions.
+
+##### **device stop (DSP)**
+
+*F: arrêt dispositif (DSP)*
+
+*S: detención de dispositivo (DSP)*
+
+The device stop (DSP) causes a designated terminal device to stop.
+
+##### **device start (DST)**
+
+*F: mise en marche dispositif (DST)*
+
+*S: arranque de dispositivo (DST)*
+
+The device start (DST) causes a designated terminal device to start.
+
+##### **device wait (DW)**
+
+*F: dispositif en attente (DW)*
+
+*S: espera de dispositivo (DW)*
+
+The device wait (DW) causes a designated terminal device to pause.
+
+#### 5.2.2.2 Coding
+
+CON is coded 1/1, COF is coded 1/4 in the C0 set. DSP, DST and DW functions are coded as 3-character sequences of the Form ESC 3/x (P), where x = 7, 6 and 5 respectively, and P is a parameter that designates a particular device.
+
+## 5.3 Serial mode
+
+### 5.3.1 General
+
+5.3.1.1 The serial mode is based on the assumption that changes in character attributes normally occur in interword spacings. This results in control characters being serially stored in the page memory and normally results in their display on the screen as a rectangle in the prevailing background colour.
+
+5.3.1.2 The C1 set for the serial mode is given in Figure 5/T.100. Display controls of the serial set causes the active position to be moved one character position forward. In that case, the position thus vacated is to be generally displayed as a space. The display control *hold mosaics* ESC 5/14 may modify this situation.
+
+### 5.3.2 Display control functions
+
+5.3.2.1 The (F<sub>e</sub>) codes are listed as follows:
+
+|                   |   |                                                                                                                                                                                                     |
+|-------------------|---|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| 5.3.2.2 Alpha red | } | Controls functions that cause the currently designated and invoked alphanumeric set to be displayed in the indicated colour until the occurrence of an explicit colour control or the end of a row. |
+| Alpha green       |   |                                                                                                                                                                                                     |
+| Alpha yellow      |   |                                                                                                                                                                                                     |
+| Alpha blue        |   |                                                                                                                                                                                                     |
+| Alpha magenta     |   |                                                                                                                                                                                                     |
+| Alpha cyan        |   |                                                                                                                                                                                                     |
+| Alpha white       |   |                                                                                                                                                                                                     |
+
+#### 5.3.2.3 Flashing
+
+A control function that causes the characters following it in the same row to be displayed alternately as they would normally be displayed, and as spaces, in the prevailing background colour, under the control of a timing device in the receiver
+
+#### 5.3.2.4 Steady
+
+A control function that causes the action of *flashing* to be stopped.
+
+#### 5.3.2.5 Start box
+
+Reserved for starting the action of defining a picture area in a page of text. (For further study.)
+
+#### 5.3.2.6 End box
+
+Reserved for terminating the action of boxing. (For further study.)
+
+#### 5.3.2.7 Normal height
+
+A control function that causes the graphic characters following it to occupy one character position each.
+
+#### 5.3.2.8 Double height
+
+A control function that causes the characters following it to occupy each its active positive and the corresponding position on the following row.
+
+#### 5.3.2.9 Mosaics red
+
+Mosaics green  
+Mosaics yellow  
+Mosaics blue  
+Mosaics magenta  
+Mosaics cyan  
+Mosaics white
+
+} Control functions that cause the mosaic graphic set to be displayed in the indicated colour until the occurrence of an explicit colour or the end of the row. Unallocated code table positions (4 / 0 - 5 / 15) cause the characters of the currently designated and invoked alphanumeric set to be displayed. This is defined as *blast – through* operation.
+
+|                |                |                |                |    | b <sub>7</sub> | 0 | 0 | 0 | 0 | 1              | 1                  | 1 | 1 |
+|----------------|----------------|----------------|----------------|----|----------------|---|---|---|---|----------------|--------------------|---|---|
+|                |                |                |                |    | b <sub>6</sub> | 0 | 0 | 1 | 1 | 0              | 0                  | 1 | 1 |
+|                |                |                |                |    | b <sub>5</sub> | 0 | 1 | 0 | 1 | 0              | 1                  | 0 | 1 |
+|                |                |                |                |    |                | 0 | 1 | 2 | 3 | 4              | 5                  | 6 | 7 |
+| b <sub>4</sub> | b <sub>3</sub> | b <sub>2</sub> | b <sub>1</sub> |    |                |   |   |   |   |                |                    |   |   |
+| 0              | 0              | 0              | 0              | 0  |                |   |   |   |   | ①              | ①                  |   |   |
+| 0              | 0              | 0              | 1              | 1  |                |   |   |   |   | Alpha red      | Mosaics red        |   |   |
+| 0              | 0              | 1              | 0              | 2  |                |   |   |   |   | Alpha green    | Mosaics green      |   |   |
+| 0              | 0              | 1              | 1              | 3  |                |   |   |   |   | Alpha yellow   | Mosaics yellow     |   |   |
+| 0              | 1              | 0              | 0              | 4  |                |   |   |   |   | Alpha blue     | Mosaics blue       |   |   |
+| 0              | 1              | 0              | 1              | 5  |                |   |   |   |   | Alpha magenta  | Mosaics magenta    |   |   |
+| 0              | 1              | 1              | 0              | 6  |                |   |   |   |   | Alpha cyan     | Mosaics cyan       |   |   |
+| 0              | 1              | 1              | 1              | 7  |                |   |   |   |   | Alpha white    | Mosaics white      |   |   |
+| 1              | 0              | 0              | 0              | 8  |                |   |   |   |   | Flashing       | Conceal display    |   |   |
+| 1              | 0              | 0              | 1              | 9  |                |   |   |   |   | Steady         | Contiguous mosaics |   |   |
+| 1              | 0              | 1              | 0              | 10 |                |   |   |   |   | End box<br>①   | Separated mosaics  |   |   |
+| 1              | 0              | 1              | 1              | 11 |                |   |   |   |   | Start Box<br>① | ①                  |   |   |
+| 1              | 1              | 0              | 0              | 12 |                |   |   |   |   | Normal height  | Black background   |   |   |
+| 1              | 1              | 0              | 1              | 13 |                |   |   |   |   | Double height  | New background     |   |   |
+| 1              | 1              | 1              | 0              | 14 |                |   |   |   |   | ①              | Hold mosaics       |   |   |
+| 1              | 1              | 1              | 1              | 15 |                |   |   |   |   | ①              | Release mosaics    |   |   |
+
+CCITT-44120
+
+① Reserved for further study.
+
+*Note* — This coding represents the final bit combination of ESC F<sub>c</sub> sequences in a 7-bit code.
+
+FIGURE 5/T.100  
+The supplementary set of control functions-serial mode
+
+#### 5.3.2.10 *Conceal display*
+
+A control function that causes all characters following it, although stored in the receiver, to be displayed as spaces until the user chooses to reveal them.
+
+#### 5.3.2.11 *Contiguous mosaics*
+
+A control function that causes the mosaic set to be displayed as represented in Figure 6/T.100 with all cells being contiguous.
+
+#### 5.3.2.12 *Separated mosaics*
+
+A control function that causes the mosaics set to be displayed as represented in Figure 6/T.100 with all cells being separated by the prevailing background colour.
+
+#### 5.3.2.13 *Black background*
+
+A control function that causes the background colour to be black.
+
+#### 5.3.2.14 *New background*
+
+A control function that causes the current colour as defined by previous colour control functions to become the new background colour. The foreground colour is unchanged.
+
+#### 5.3.2.15 *Hold mosaics*
+
+A control function that causes the character positions occupied by display controls to be displayed by repetition of the last displayable mosaic character.
+
+#### 5.3.2.16 *Release mosaics*
+
+A control function that causes the action of *hold mosaics* to be stopped.
+
+### 5.3.3 *Mosaic graphics*
+
+5.3.3.1 The *serial mosaic* graphic set is given in Figure 6/T.100 and the default conditions of the mode are shown in Table 1/T.100.
+
+## 5.4 *Parallel mode*
+
+### 5.4.1 *General*
+
+5.4.1.1 The *parallel* mode is based on an explicit description of the display frame. This means that the active position is moved only by action of the format effectors or at the reception of spacing display characters. All other functions, including display functions, are non-spacing, not depending on whether or not the terminal needs a space on the screen to process them. It is the responsibility of the information provider to limit the display of pages to pages to fit the capability assumed to receive, without any modification, pages designed for lower grade terminals.
+
+5.4.1.2 In addition to functions described in § 3.3, the following functions are defined.
+
+#### **active position addressing (APA, coded 1/15)**
+
+*F: adressage de position active (APA)*
+
+*S: direccionamiento de posición activa (APA)*
+
+This code is followed by two characters. If these both range from 3/0 to 3/9, they represent in decimal form respectively the tens and units of the row address of the first character to be displayed. This first character will be displayed on the first character position of the addressed row. If they both range from 4/0 to 7/14, they represent respectively the row address and the column address. in binary form with 6 useful bits, of the first characters to be displayed.
+
+|                |                |                |                |    |                |   |   |   |   |   |   |   |   |
+|----------------|----------------|----------------|----------------|----|----------------|---|---|---|---|---|---|---|---|
+|                |                |                |                |    | b <sub>7</sub> | 0 | 0 | 0 | 0 | 1 | 1 | 1 | 1 |
+|                |                |                |                |    | b <sub>6</sub> | 0 | 0 | 1 | 1 | 0 | 0 | 1 | 1 |
+|                |                |                |                |    | b <sub>5</sub> | 0 | 1 | 0 | 1 | 0 | 1 | 0 | 1 |
+|                |                |                |                |    |                | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
+| b <sub>4</sub> | b <sub>3</sub> | b <sub>2</sub> | b <sub>1</sub> |    |                |   |   |   |   |   |   |   |   |
+| 0              | 0              | 0              | 0              | 0  |                |   |   |   |   |   |   |   |   |
+| 0              | 0              | 0              | 1              | 1  |                |   |   |   |   |   |   |   |   |
+| 0              | 0              | 1              | 0              | 2  |                |   |   |   |   |   |   |   |   |
+| 0              | 0              | 1              | 1              | 3  |                |   |   |   |   |   |   |   |   |
+| 0              | 1              | 0              | 0              | 4  |                |   |   |   |   |   |   |   |   |
+| 0              | 1              | 0              | 1              | 5  |                |   |   |   |   |   |   |   |   |
+| 0              | 1              | 1              | 0              | 6  |                |   |   |   |   |   |   |   |   |
+| 0              | 1              | 1              | 1              | 7  |                |   |   |   |   |   |   |   |   |
+| 1              | 0              | 0              | 0              | 8  |                |   |   |   |   |   |   |   |   |
+| 1              | 0              | 0              | 1              | 9  |                |   |   |   |   |   |   |   |   |
+| 1              | 0              | 1              | 0              | 10 |                |   |   |   |   |   |   |   |   |
+| 1              | 0              | 1              | 1              | 11 |                |   |   |   |   |   |   |   |   |
+| 1              | 1              | 0              | 0              | 12 |                |   |   |   |   |   |   |   |   |
+| 1              | 1              | 0              | 1              | 13 |                |   |   |   |   |   |   |   |   |
+| 1              | 1              | 1              | 0              | 14 |                |   |   |   |   |   |   |   |   |
+| 1              | 1              | 1              | 1              | 15 |                |   |   |   |   |   |   |   |   |
+
+CCITT-44130
+
+![Separated mosaics representation icon showing a 2x2 grid of squares with different patterns.](1630bfd9ebf9b95faec11ae6cdfd9c0a_img.jpg)
+
+Separated mosaics representation icon showing a 2x2 grid of squares with different patterns.
+
+Separated mosaics representation
+
+FIGURE 6/T.100
+
+The mosaic set for the serial mode with blast-through characters in columns 4 and 5
+
+TABLE 1/T.100
+
+#### Display modes and control characters-serial mode
+
+| Display mode               |                | Set at         | Set after<br>(see Note)                                          | Complementary display mode |                | Set at | Set after<br>(see Note)        |
+|----------------------------|----------------|----------------|------------------------------------------------------------------|----------------------------|----------------|--------|--------------------------------|
+| Alphanumerics              |                | Row start      | 4/1 4/2 4/3<br>4/4 4/5 4/6 4/7                                   | Block mosaics              |                | –      | 5/1 5/2 5/3<br>5/4 5/5 5/6 5/7 |
+| Contiguous                 |                | Row start 5/9  | 5/9                                                              | Separated                  |                | 5/10   | 5/10                           |
+| Fore-ground display colour | includes red   | Row start      | 4/1 4/3 4/5 4/7<br>5/1 5/3 5/5 5/7                               | Fore-ground display colour | excludes red   | –      | 4/2 4/4 4/6<br>5/2 5/4 5/6     |
+|                            | includes green | Row start      | 4/2 4/3 4/6 4/7<br>5/2 5/3 5/6 5/7                               |                            | excludes green | –      | 4/1 4/4 4/5<br>5/1 5/4 5/5     |
+|                            | includes blue  | Row start      | 4/4 4/5 4/6 4/7<br>5/4 5/5 5/6 5/7                               |                            | excludes blue  | –      | 4/1 4/2 4/3<br>5/1 5/2 5/3     |
+| Black background           |                | Row start 5/12 | –                                                                | New background colour      |                | 5/13   | –                              |
+| Stop conceal               |                | Row start      | 4/1 4/2 4/3<br>4/4 4/5 4/6 4/7<br>5/1 5/2 5/3<br>5/4 5/5 5/6 5/7 | Conceal                    |                | 5/8    | –                              |
+| Steady                     |                | Row start 4/9  | –                                                                | Flash                      |                | –      | 4/8                            |
+| Unboxed                    |                | Row start 4/10 | 4/10                                                             | Boxed                      |                | 4/11   | 4/11                           |
+| Normal height              |                | Row start 4/12 | –                                                                | Double height              |                | –      | 4/13                           |
+| Release                    |                | Row start      | 5/15                                                             | Hold                       |                | 5/14   | –                              |
+
+Note – All attribute control characters are preceded by Escape ESC.
+
+#### repeat (RPT, coded 1/2)
+
+*F: répétition (RPT)*
+
+*S: repetición (RPT)*
+
+This code indicates that the preceding graphics character is to be repeated. The number of repetitions is indicated in binary form by the six least significant bits of the subsequent character chosen from columns 4 to 7. The character itself is not included in the count. This function does not apply to control characters.
+
+5.4.1.3 A supplementary set of 32 controls, of which 31 have been allocated, are coded as a C1 set (see Figure 7/T.100). The attributes defined by such controls become a property of the active position and move with it under the action of format effectors or spacing display characters.
+
+5.4.1.4 The mosaic repertoire is coded as a G1 set, of which several representations may be defined (see Figure 8/T.100).
+
+### 5.4.2 Display control functions
+
+5.4.2.1 The display control functions are of two kinds depending on the range of their action:
+
+- *Defined display area attributes* apply to individual character locations. Their action is limited to zones separated by APA functions.
+- *Full screen attributes* apply to the full screen area and are taken as default values for defined display area attributes.
+
+The defined display area attributes are coded as functions from the supplementary set of control functions (see Figure 7/T.100), with two character escape sequences.
+
+The full screen attribute is coded as a function from the supplementary set of control functions with four character escape sequences (see § 5.4.2.3).
+
+5.4.2.2 Attributes for use in the defined display area are as follows.
+
+|           |                    |                                                                          |
+|-----------|--------------------|--------------------------------------------------------------------------|
+| 5.4.2.2.1 | Black foreground   | } Causes the following characters to be written in the colour indicated. |
+|           | Red foreground     |                                                                          |
+|           | Green foreground   |                                                                          |
+|           | Yellow foreground  |                                                                          |
+|           | Blue foreground    |                                                                          |
+|           | Magenta foreground |                                                                          |
+|           | Cyan foreground    |                                                                          |
+|           | White foreground   |                                                                          |
+
+##### 5.4.2.2.2 Flashing
+
+This control function causes the characters following it to be displayed alternatively as they would otherwise be displayed, and as spaces, under the control of a timing device in the receiver.
+
+##### 5.4.2.2.3 Steady
+
+This control function causes the action of *flashing* to be stopped.
+
+##### 5.4.2.2.4 Start box
+
+This control function causes the characters following it to be inset or added to a television picture, when the receiver is in the user's control. (For further study.)
+
+##### 5.4.2.2.5 *End box*
+
+This control function causes the action of *start box* to be stopped. (For further study.)
+
+##### 5.4.2.2.6 *Normal size*
+
+This control function causes the characters following it to occupy one character position each.
+
+|                |                |                |                |    |                |   |   |   |   |                   |                          |   |   |
+|----------------|----------------|----------------|----------------|----|----------------|---|---|---|---|-------------------|--------------------------|---|---|
+|                |                |                |                |    | b <sub>7</sub> | 0 | 0 | 0 | 0 | 1                 | 1                        | 1 | 1 |
+|                |                |                |                |    | b <sub>6</sub> | 0 | 0 | 1 | 1 | 0                 | 0                        | 1 | 1 |
+|                |                |                |                |    | b <sub>5</sub> | 0 | 1 | 0 | 1 | 0                 | 1                        | 0 | 1 |
+|                |                |                |                |    |                | 0 | 1 | 2 | 3 | 4                 | 5                        | 6 | 7 |
+| b <sub>4</sub> | b <sub>3</sub> | b <sub>2</sub> | b <sub>1</sub> |    | 0              | 0 | 0 | 0 | 0 | Black fore-ground | Black back-ground        |   |   |
+| 0              | 0              | 0              | 1              | 1  |                |   |   |   |   | Red F....         | Red B....                |   |   |
+| 0              | 0              | 1              | 0              | 2  |                |   |   |   |   | Green F....       | Green B....              |   |   |
+| 0              | 0              | 1              | 1              | 3  |                |   |   |   |   | Yellow F....      | Yellow B....             |   |   |
+| 0              | 1              | 0              | 0              | 4  |                |   |   |   |   | Blue F....        | Blue B....               |   |   |
+| 0              | 1              | 0              | 1              | 5  |                |   |   |   |   | Magenta F....     | Magenta B....            |   |   |
+| 0              | 1              | 1              | 0              | 6  |                |   |   |   |   | Cyan F....        | Cyan B....               |   |   |
+| 0              | 1              | 1              | 1              | 7  |                |   |   |   |   | White F....       | White B....              |   |   |
+| 1              | 0              | 0              | 0              | 8  |                |   |   |   |   | Flash             | Conceal display          |   |   |
+| 1              | 0              | 0              | 1              | 9  |                |   |   |   |   | Steady            | Stop lining              |   |   |
+| 1              | 0              | 1              | 0              | 10 |                |   |   |   |   | End box ①         | Start lining             |   |   |
+| 1              | 0              | 1              | 1              | 11 |                |   |   |   |   | Start box ①       | ②                        |   |   |
+| 1              | 1              | 0              | 0              | 12 |                |   |   |   |   | Normal size       | Normal polarity          |   |   |
+| 1              | 1              | 0              | 1              | 13 |                |   |   |   |   | Double height     | Inverted polarity        |   |   |
+| 1              | 1              | 1              | 0              | 14 |                |   |   |   |   | Double width      | Trans-parent back-ground |   |   |
+| 1              | 1              | 1              | 1              | 15 |                |   |   |   |   | Double size       | Stop conceal             |   |   |
+
+1 For further study
+
+CCITT-44140
+
+2 Reserved for CSI
+
+Note — This coding represents the final bit combination of ESC F<sub>c</sub> sequences in a 7-bit code
+
+FIGURE 7/T.100  
+Supplementary set of control functions — parallel mode
+
+|                |                |                |                |    | b <sub>7</sub> | 0                                       | 0                                       | 0                                 | 0                                            | 1 | 1                               | 1                                 | 1                                 |
+|----------------|----------------|----------------|----------------|----|----------------|-----------------------------------------|-----------------------------------------|-----------------------------------|----------------------------------------------|---|---------------------------------|-----------------------------------|-----------------------------------|
+|                |                |                |                |    | b <sub>6</sub> | 0                                       | 0                                       | 1                                 | 0                                            | 0 | 1                               | 1                                 |                                   |
+|                |                |                |                |    | b <sub>5</sub> | 0                                       | 1                                       | 0                                 | 1                                            | 0 | 1                               | 0                                 | 1                                 |
+|                |                |                |                |    |                | 0                                       | 1                                       | 2                                 | 3                                            | 4 | 5                               | 6                                 | 7                                 |
+| b <sub>4</sub> | b <sub>3</sub> | b <sub>2</sub> | b <sub>1</sub> |    |                | <p>Image: stippled pattern column 0</p> | <p>Image: stippled pattern column 1</p> | <p>Image: lined mosaic 000001</p> | <p>Image: lined mosaic 000011</p>            |   |                                 | <p>Image: lined mosaic 000001</p> | <p>Image: lined mosaic 000011</p> |
+| 0              | 0              | 0              | 0              | 0  |                |                                         |                                         | <p>Image: lined mosaic 000010</p> | <p>Image: lined mosaic 000110</p>            |   |                                 | <p>Image: lined mosaic 000010</p> | <p>Image: lined mosaic 000110</p> |
+| 0              | 0              | 0              | 1              | 1  |                |                                         |                                         | <p>Image: lined mosaic 000100</p> | <p>Image: lined mosaic 001100</p>            |   |                                 | <p>Image: lined mosaic 000100</p> | <p>Image: lined mosaic 001100</p> |
+| 0              | 0              | 1              | 0              | 2  |                |                                         |                                         | <p>Image: lined mosaic 001000</p> | <p>Image: lined mosaic 011000</p>            |   |                                 | <p>Image: lined mosaic 001000</p> | <p>Image: lined mosaic 011000</p> |
+| 0              | 0              | 1              | 1              | 3  |                |                                         |                                         | <p>Image: lined mosaic 010000</p> | <p>Image: lined mosaic 110000</p>            |   |                                 | <p>Image: lined mosaic 010000</p> | <p>Image: lined mosaic 110000</p> |
+| 0              | 1              | 0              | 0              | 4  |                |                                         |                                         | <p>Image: lined mosaic 100000</p> | <p>Image: lined mosaic 100001</p>            |   |                                 | <p>Image: lined mosaic 100000</p> | <p>Image: lined mosaic 100001</p> |
+| 0              | 1              | 0              | 1              | 5  |                |                                         |                                         | <p>Image: lined mosaic 000101</p> | <p>Image: lined mosaic 000111</p>            |   |                                 | <p>Image: lined mosaic 000101</p> | <p>Image: lined mosaic 000111</p> |
+| 0              | 1              | 1              | 0              | 6  |                |                                         |                                         | <p>Image: lined mosaic 001010</p> | <p>Image: lined mosaic 001110</p>            |   |                                 | <p>Image: lined mosaic 001010</p> | <p>Image: lined mosaic 001110</p> |
+| 0              | 1              | 1              | 1              | 7  |                |                                         |                                         | <p>Image: lined mosaic 010100</p> | <p>Image: lined mosaic 110100</p>            |   |                                 | <p>Image: lined mosaic 010100</p> | <p>Image: lined mosaic 110100</p> |
+| 1              | 0              | 0              | 0              | 8  |                |                                         |                                         | <p>Image: lined mosaic 101000</p> | <p>Image: lined mosaic 101001</p>            |   |                                 | <p>Image: lined mosaic 101000</p> | <p>Image: lined mosaic 101001</p> |
+| 1              | 0              | 0              | 1              | 9  |                |                                         |                                         | <p>Image: lined mosaic 011001</p> | <p>Image: lined mosaic 111001</p>            |   |                                 | <p>Image: lined mosaic 011001</p> | <p>Image: lined mosaic 111001</p> |
+| 1              | 0              | 1              | 0              | 10 |                |                                         |                                         | <p>Image: lined mosaic 110010</p> | <p>Image: lined mosaic 110110</p>            |   |                                 | <p>Image: lined mosaic 110010</p> | <p>Image: lined mosaic 110110</p> |
+| 1              | 0              | 1              | 1              | 11 |                |                                         |                                         | <p>Image: lined mosaic 101100</p> | <p>Image: lined mosaic 101101</p>            |   |                                 | <p>Image: lined mosaic 101100</p> | <p>Image: lined mosaic 101101</p> |
+| 1              | 1              | 0              | 0              | 12 |                |                                         |                                         | <p>Image: lined mosaic 011110</p> | <p>Image: lined mosaic 111110</p>            |   |                                 | <p>Image: lined mosaic 011110</p> | <p>Image: lined mosaic 111110</p> |
+| 1              | 1              | 0              | 1              | 13 |                |                                         |                                         | <p>Image: lined mosaic 111011</p> | <p>Image: lined mosaic 111111</p>            |   |                                 | <p>Image: lined mosaic 111011</p> | <p>Image: lined mosaic 111111</p> |
+| 1              | 1              | 1              | 0              | 14 |                |                                         |                                         | <p>Image: lined mosaic 111101</p> | <p>Image: lined mosaic 111111 full block</p> |   | <p>Image: solid black block</p> | <p>Image: lined mosaic 111101</p> | <p>Image: stippled pattern</p>    |
+| 1              | 1              | 1              | 1              | 15 |                |                                         |                                         |                                   |                                              |   |                                 |                                   |                                   |
+
+CCITT-44150
+
+![Diagram of a lined mosaic character showing a 2x3 grid with internal separation lines.](05c9994c1f5daf53d0d9b107657d7a17_img.jpg)
+
+Diagram of a lined mosaic character showing a 2x3 grid with internal separation lines.
+
+« Lined » mosaic character
+
+FIGURE 8/T.100  
+The mosaic character set — parallel mode
+
+##### 5.4.2.2.7 *Double height*
+
+This control function causes the characters following it to occupy each its active position and the corresponding position on the previous row. (The origin of a character is the bottom left corner of the character position.)
+
+##### 5.4.2.2.8 *Double width*
+
+This control function causes the characters following it to occupy two consecutive character positions on the same row, and the active position to be moved two positions forward with every character.
+
+##### 5.4.2.2.9 *Double size*
+
+This control function causes the characters following it to occupy the active position, the next on the row and the two corresponding character positions on the previous row. The active position is moved two character positions forward with every character.
+
+|            |                    |                                                                                                                       |
+|------------|--------------------|-----------------------------------------------------------------------------------------------------------------------|
+| 5.4.2.2.10 | Black background   | } Causes the following characters to be displayed in their foreground colour on a background of the colour indicated. |
+|            | Red background     |                                                                                                                       |
+|            | Green background   |                                                                                                                       |
+|            | Yellow background  |                                                                                                                       |
+|            | Blue background    |                                                                                                                       |
+|            | Magenta background |                                                                                                                       |
+|            | Cyan background    |                                                                                                                       |
+|            | White background   |                                                                                                                       |
+
+##### 5.4.2.2.11 *Transparent background*
+
+This control function causes the characters following it to be displayed with a transparent background. This means the area not occupied by the foreground colour takes the underlying background colour. This may be one of the eight colours or the video picture as defined by the off screen attributes.
+
+##### 5.4.2.2.12 *Conceal display*
+
+This control function causes the characters following it, in the same unit although stored in the receiver, to be displayed as spaces until the user chooses to reveal them.
+
+##### 5.4.2.2.13 *Stop conceal*
+
+This control function causes the action of *conceal display* to be stopped.
+
+##### 5.4.2.2.14 *Start lining*
+
+This control function causes the characters following in the same unit to be lined. The shape of lining may be different depending on the character set used. In the case of the mosaic set, the lining causes the six cells to be separated with a background boundary.
+
+##### 5.4.2.2.15 *Stop lining*
+
+This control function causes the action of *start lining* to be stopped.
+
+##### 5.4.2.2.16 *Normal polarity*
+
+This control function causes the action of *inverted polarity* to be stopped.
+
+##### 5.4.2.2.17 *Inverted polarity*
+
+This control function causes the characters following it, in the same unit, to be displayed as if the background and the foreground colour have been exchanged. In the flashing attribute, the polarity of the flashing clock is also inverted.
+
+#### 5.4.2.3 *Full-screen attributes*
+
+5.4.2.3.1 Full-screen attributes apply for the total display period and include the border area. In addition, provisions are made for full-row attributes, applying for the entire row including the border area related to that row.
+
+Full-screen attributes display controls are represented by four character *Escape* sequences of the form ESC 2/3 2/0 F<sub>e</sub> where F<sub>e</sub> is taken from Figure 7/T.100.
+
+Full-row attributes display controls are represented by four-character *Escape* sequences of the form ESC 2/3 2/1 F<sub>e</sub>.
+
+5.4.2.3.2 The following full-screen attributes need precise definition:
+
+- *Transparent background*: The full-screen area is occupied by a picture, which may not be part of the Videotex service (e.g. a television picture). Non-concealed characters appear on this picture. If they are also displayed with defined display area transparent background, only the foreground appears over the picture. Concealed characters are displayed as transparent spaces.
+- *Conceal*: The defined display area is in the full-screen background colour until the user chooses to reveal it or until this attribute is stopped by full-screen stop conceal.
+- *Full-screen stop conceal*: This has the same action as the action of the user on the reveal key.
+
+5.4.2.3.3 For row-defined full-screen attributes, the following may also apply:
+
+- lined;
+- double width;
+- double height.
+
+### 5.4.3 *Coding of the mosaic repertoire*
+
+5.4.3.1 The mosaic repertoire is designated as a G1 set invoked by the SO function. Two alternative fonts (contiguous and separated) are proposed. The separated font is obtained by applying the lining attribute applied to the mosaic set. The mosaic set code table is given in Figure 8/T.100 together with examples of the fonts.
+
+### 5.4.4 *Default conditions*
+
+#### 5.4.4.1 *Default full-screen attributes*
+
+At the beginning of a display frame (initiated by function CS) the default conditions for full-screen attributes are set at white foreground, black background, single size, unboxed, revealed, steady, non-lined.
+
+#### 5.4.4.2 *Default defined display area attributes*
+
+After functions directly addressing a character location on the screen (APH or APA function) the defined display area attributes are reset to the value of the current full-screen attributes.
+
+#### 5.4.4.3 *Default full-row attributes*
+
+The default condition of full-row attributes is the current value of full-screen attributes.
+
+# 6 **Alphageometric option**
+
+## 6.1 *General*
+
+### 6.1.1 *Description*
+
+6.1.1.1 In the alphageometric option, the display is composed of alphanumeric texts and pictorial drawings that are defined in terms of geometric primitives transmitted to the terminal as drawing commands,
+
+6.1.1.2 One coding scheme for the alphageometric option for Videotex is described in § 6.
+
+### 6.1.2 *Designation and invocation of geometric codes*
+
+6.1.2.1 The designation and invocation of the alpheageometric code is specified in § 2.3.
+
+The occurrence of the control function SO invokes the geometric primitives in code table positions 2/0 to 7/15 inclusive. The occurrence of the code function SI re-establishes the G0 set and the *space* (2/0) and *delete* (7/15) functions.
+
+### 6.1.3 *Geometric primitives*
+
+6.1.3.1 The coding scheme for the G1 set together with the code positions 2/0 and 7/15 for the geometric model is based on geometric primitives. Each drawing primitive is specified in terms of Cartesian coordinates to describe the positions, end-points, or vertices of each drawing operation.
+
+6.1.3.2 Geometric drawings are defined in terms of the drawing primitives: *point*, *line*, *arc*, *rectangle*, and *polygon*.
+
+### 6.1.4 *Drawing position*
+
+6.1.4.1 Drawings are positionally independent; therefore drawing primitives may overlay each other redefining the drawing at the position.
+
+### 6.1.5 *Drawing space*
+
+6.1.5.1 Space for geometric drawing operations consists of a rectangular area entirely visible on the display screen. Any area of the display screen outside of the valid drawing area is termed a *border area* and it is not possible to specify a coordinate position in a border area.
+
+### 6.1.6 *Picture element*
+
+6.1.6.1 The Cartesian coordinate grid is made up of square picture elements (pixels).
+
+### 6.1.7 *Picture resolution*
+
+6.1.7.1 Any number of picture elements may be implemented. Hence, picture resolution is at the discretion of terminal manufacturers.
+
+### 6.1.8 *Coordinate system*
+
+6.1.8.1 The coordinate specifications are defined based on a Cartesian 0 to 1 numbering scheme.
+
+6.1.8.2 The numbering system is referenced to the visible valid drawing area and consists of coordinates ranging from 0 to 1 on both the X and Y axes, with coordinate values being specified as fractions of this range.
+
+6.1.8.3 The coordinates are encoded in 2's complement notation and specified as signed numbers to a minimum accuracy of 9 bits, including the sign bit. Increased accuracy is obtained by additional increments of 3 bits. Unused least significant bits are truncated when the coordinates are defined to a greater accuracy than can be handled by the terminal.
+
+6.1.8.4 Display screens with non-square visible areas map into the square drawing area number system so that the origin (0,0) remains in the lower left-hand corner. On a television-like display with a 4 : 3 aspect ratio, this corresponds to a range of 0 to 0.999 ... in the X axis and 0 to approximately 0.75 in the Y axis. Drawing commands addressing the entire square 0 to 1 grid are permissible, but only the circumscribed 4 : 3 area is visible.
+
+## 6.2 *Drawing command*
+
+### 6.2.1 *General*
+
+6.2.1.1 Drawing commands consist of *operational codes* (opcodes) and their associated data parameters.
+
+6.2.1.2 Opcodes describe the types of drawing operation.
+
+6.2.1.3 Following the opcode byte are one or more blocks of additional bytes of data to describe one or more (X, Y) coordinate positions. Each block of data for the (X, Y) coordinates may contain 3 bytes (9 bits accuracy), 4 bytes (12 bits accuracy), etc., depending on the degree of resolution desired.
+
+6.2.1.4 Figure 9/T.100 is the code table for the opcodes and data bytes or status sub-commands.
+
+### 6.2.2 *Opcode byte*
+
+6.2.2.1 The structure of the opcode byte is as shown in Figure 10/T.100.
+
+### 6.2.3. *Opcode definitions*
+
+#### 6.2.3.1 *Point*
+
+Sets the drawing beam to any position in the display space and optionally draws a point.
+
+#### 6.2.3.2 *Line*
+
+Draws a line based on the two given end points.
+
+#### 6.2.3.3 *Arc*
+
+Draws a circular arc based on three points, which are the start point, a point on the arc and the end point of the arc. A circle results when the start and end points are coincidental and the point on the arc defines the opposite end of the diameter. The arc may be either in outline or the area enclosed by the arc and the chord may be filled.
+
+#### 6.2.3.4 *Rectangle*
+
+Draws a rectangle based on specified width and height. The rectangle may be in outline or a filled-in area.
+
+#### 6.2.3.5 *Polygon*
+
+Draws a closed polygon of arbitrary shape specified by the vertices. The polygon may be in outline or a filled-in area. The maximum number of vertices is limited to 256.
+
+#### 6.2.3.6 *Spare*
+
+An opcode available for future definition.
+
+#### 6.2.3.7 *Reserved*
+
+An opcode reserved for a specific future application.
+
+#### 6.2.3.8 *Control*
+
+Provides control over the modes or attributes of the drawing commands.
+
+### 6.2.4 *Opcode facilities*
+
+6.2.4.1 Each opcode has four variants; these are defined by the facility bits (b2 and b1) as shown in Figure 11/T.100. Facility field interpretations are as given below.
+
+| b <sub>7</sub> |                |                | 0              | 0  | 0 | 0 | 1                              | 1                                             | 1                                                         | 1 |  |  |
+|----------------|----------------|----------------|----------------|----|---|---|--------------------------------|-----------------------------------------------|-----------------------------------------------------------|---|--|--|
+| b <sub>6</sub> |                |                | 0              | 0  | 1 | 1 | 0                              | 0                                             | 1                                                         | 1 |  |  |
+| b <sub>5</sub> |                |                | 0              | 1  | 0 | 1 | 0                              | 1                                             | 0                                                         | 1 |  |  |
+|                |                |                | 0              | 1  | 2 | 3 | 4                              | 5                                             | 6                                                         | 7 |  |  |
+| b <sub>4</sub> | b <sub>3</sub> | b <sub>2</sub> | b <sub>1</sub> |    |   |   | S<br>p<br>a<br>c<br>e          | R<br>e<br>c<br>t<br><br>4                     | Numeric data<br>(for opcodes)<br>or<br>status<br>commands |   |  |  |
+| 0              | 0              | 0              | 0              | 0  |   |   |                                |                                               |                                                           |   |  |  |
+| 0              | 0              | 0              | 1              | 1  |   |   |                                |                                               |                                                           |   |  |  |
+| 0              | 0              | 1              | 0              | 2  |   |   |                                |                                               |                                                           |   |  |  |
+| 0              | 0              | 1              | 1              | 3  |   |   | P<br>o<br>i<br>n<br>t<br><br>1 | P<br>o<br>l<br>y<br><br>5                     |                                                           |   |  |  |
+| 0              | 1              | 0              | 0              | 4  |   |   |                                |                                               |                                                           |   |  |  |
+| 0              | 1              | 0              | 1              | 5  |   |   |                                |                                               |                                                           |   |  |  |
+| 0              | 1              | 1              | 0              | 6  |   |   |                                |                                               |                                                           |   |  |  |
+| 0              | 1              | 1              | 1              | 7  |   |   | L<br>i<br>n<br>e<br><br>2      | R<br>e<br>s<br>e<br>r<br>v<br>e<br>d<br><br>6 |                                                           |   |  |  |
+| 1              | 0              | 0              | 0              | 8  |   |   |                                |                                               |                                                           |   |  |  |
+| 1              | 0              | 0              | 1              | 9  |   |   |                                |                                               |                                                           |   |  |  |
+| 1              | 0              | 1              | 0              | 10 |   |   |                                |                                               |                                                           |   |  |  |
+| 1              | 0              | 1              | 1              | 11 |   |   | A<br>r<br>c<br><br>3           | C<br>o<br>n<br>t<br>r<br>o<br>l<br><br>7      |                                                           |   |  |  |
+| 1              | 1              | 0              | 0              | 12 |   |   |                                |                                               |                                                           |   |  |  |
+| 1              | 1              | 0              | 1              | 13 |   |   |                                |                                               |                                                           |   |  |  |
+| 1              | 1              | 1              | 0              | 14 |   |   |                                |                                               |                                                           |   |  |  |
+| 1              | 1              | 1              | 1              | 15 |   |   |                                |                                               |                                                           |   |  |  |
+
+CCITT-44160
+
+FIGURE 9/T.100  
+Operation code and data field assignments
+
+Fascicle VII.5 - Rec. T.100 27
+
+![Diagram of the 8-bit opcode byte structure. The byte is divided into four fields: Parity (b8), Flag (b7, b6), Descriptor field (b5, b4, b3), and Facilities field (b2, b1). The Parity field contains 'P'. The Flag field contains '0' and '1'. The Descriptor field contains three bits. The Facilities field contains two bits. The diagram is labeled CCITT-44170.](11edb7fcedf09ac6a817f8d7b8c61eec_img.jpg)
+
+b8   b7   b6   b5   b4   b3   b2   b1
+
+|   |   |   |  |  |  |  |  |
+|---|---|---|--|--|--|--|--|
+| P | 0 | 1 |  |  |  |  |  |
+|---|---|---|--|--|--|--|--|
+
+Parity   
+Flag   
+Facilities field   
+Description field
+
+CCITT-44170
+
+Diagram of the 8-bit opcode byte structure. The byte is divided into four fields: Parity (b8), Flag (b7, b6), Descriptor field (b5, b4, b3), and Facilities field (b2, b1). The Parity field contains 'P'. The Flag field contains '0' and '1'. The Descriptor field contains three bits. The Facilities field contains two bits. The diagram is labeled CCITT-44170.
+
+**FIGURE 10/T.100**  
+**8-bit opcode byte**
+
+| Opcode    | Parity | Flag |    | Descriptor<br>field | Facility field |     |         |      |
+|-----------|--------|------|----|---------------------|----------------|-----|---------|------|
+|           |        |      |    |                     | b2             |     | b1      |      |
+|           |        |      |    |                     | 0              | 1   | 0       | 1    |
+|           | b8     | b7   | b6 | b5 b4 b3            | 0              | 1   | 0       | 1    |
+| Spare     | P      | 0    | 1  | 0 0 0               | –              | –   | –       | –    |
+| Point     | P      | 0    | 1  | 0 0 1               | INVS           | VIS | ABS     | REL  |
+| Line      | P      | 0    | 1  | 0 1 0               | JOIN           | SET | ABS     | REL  |
+| Arc       | P      | 0    | 1  | 0 1 1               | JOIN           | SET | OUTLINE | FILL |
+| Rectangle | P      | 0    | 1  | 1 0 0               | JOIN           | SET | OUTLINE | FILL |
+| Polygon   | P      | 0    | 1  | 1 0 1               | JOIN           | SET | OUTLINE | FILL |
+| Reserved  | P      | 0    | 1  | 1 1 0               | –              | –   | –       | –    |
+| Control   | P      | 0    | 1  | 1 1 1               |                |     |         |      |
+
+|       |           |     |          |
+|-------|-----------|-----|----------|
+| INVIS | Invisible | ABS | Absolute |
+| VIS   | Visible   | REL | Relative |
+
+**FIGURE 11/T.100**  
+**Opcode facilities**
+
+#### 6.2.4.2 *b2 is binary 1*
+
+- a) *Point* – A visible point is drawn on the display screen.
+- b) *Line, arc, rectangle, polygon* – The initial drawing position is specified within the data bytes as absolute (X, Y) coordinates, i.e. the initial point is *set*.
+
+#### 6.2.4.3 *b2 is binary 0*
+
+- a) *Point* – An invisible point is located on the display screen.
+- b) *Line, arc, rectangle, polygon* – The initial drawing position is the same point as the final drawing position of the previous opcode, i.e., the current drawing is joined to the previous drawing.
+
+#### 6.2.4.4 *b1 is binary 1*
+
+- a) *Point* – The (X, Y) coordinates are relative displacements to the preceding coordinate specifications.
+- b) *Line* – The (X, Y) coordinates for the final drawing position of a line segment are relative displacements from initial drawing position of that line segment.
+- c) *Arc, rectangle, polygon* – The areas established are filled or crosshatched.
+
+#### 6.2.4.5 *b1 is binary 0*
+
+- a) *Point* – The (X, Y) coordinates of the point are absolute values.
+- b) *Line* – The (X, Y) coordinates of the final drawing position of the line segment are absolute values.
+- c) *Arc, rectangle, polygon* – The drawings are outlined.
+
+## 6.3 *Opcode numeric data*
+
+6.3.1 The numerical data bytes associated with an opcode immediately follow the opcode byte and are recognized when the flag bit (b7) is binary 1. Any number of blocks of data bytes defining pairs of coordinates or drawing displacements may follow the drawing opcode until one of the following conditions occurs:
+
+- a) when another opcode is encountered;
+- b) when the *shift-in* code (SI) is encountered;
+- c) when the *shift-out* code (SO) is encountered;
+- d) when the *single-shift* codes (SS2 or SS3) are encountered;
+- e) when an *escape* (ESC) code is encountered.
+
+6.3.2 The minimum number of data bytes that forms a block that defines a pair of X, Y coordinates is three. The structure of the data block is shown in Figure 12/T.100.
+
+![Diagram showing the structure of a block of 3 data bytes for X and Y coordinates. It illustrates three bytes, each with a Parity bit (P), a Flag bit (1), and two data bits. The first byte is labeled with X and Y coordinates. The second and third bytes are labeled with numeric specification in decreasing bit significance.](dfa6249d64e9f63db89f2c5b7bbd01de_img.jpg)
+
+The diagram illustrates the structure of a block of 3 data bytes for X and Y coordinates. It shows three bytes, each represented as a horizontal rectangle divided into four sections: Parity (P), Flag (1), and two data bits. The first byte is labeled with X and Y coordinates. The second and third bytes are labeled with numeric specification in decreasing bit significance. The diagram is labeled CCITT-44180.
+
+Diagram showing the structure of a block of 3 data bytes for X and Y coordinates. It illustrates three bytes, each with a Parity bit (P), a Flag bit (1), and two data bits. The first byte is labeled with X and Y coordinates. The second and third bytes are labeled with numeric specification in decreasing bit significance.
+
+FIGURE 12/T.100  
+Structure of a block of 3 data bytes
+
+## 6.4 Repeated opcode operation
+
+6.4.1 For each of the *point*, *line* and *rectangle* opcodes, repeated drawing operations will automatically be effected if the numerical data field following the opcode byte contains more than one complete set of coordinate specifications. A complete set of coordinate specifications is defined as all the coordinates needed to define a *point*, *line* or *rectangle* drawing as a single drawing. That is, the repeated drawing feature allows concatenated drawings to be effected without having to repeat the opcode itself.
+
+## 6.5 Geometric control opcode
+
+### 6.5.1 General
+
+6.5.1.1 The *control* opcodes control the drawing states of the terminal and the interpretation of the drawing opcode attributes. The sequence of *control* opcodes and their *status* sub-commands always precedes the opcodes for the geometric drawing primitives of *point*, *line*, *arc*, *rectangle*, or *polygon*. The controls also apply to text in *shift-in* (SI) mode. The four *control* opcodes, distinguished by the opcode facilities bits, (b2 and b1), are given in Figure 13/T.100.
+
+![Figure 13/T.100 Control codes diagram showing bit patterns for value, status, reserved, and private control opcodes.](933ecd14c858bf3fc919222d8e357bc8_img.jpg)
+
+|                    |                                                                                                                     |   |   |   |   |   |   |   |   |
+|--------------------|---------------------------------------------------------------------------------------------------------------------|---|---|---|---|---|---|---|---|
+| Control (value)    | <table border="1"><tr><td>P</td><td>0</td><td>1</td><td>1</td><td>1</td><td>1</td><td>0</td><td>0</td></tr></table> | P | 0 | 1 | 1 | 1 | 1 | 0 | 0 |
+| P                  | 0                                                                                                                   | 1 | 1 | 1 | 1 | 0 | 0 |   |   |
+| Control (status)   | <table border="1"><tr><td>P</td><td>0</td><td>1</td><td>1</td><td>1</td><td>1</td><td>0</td><td>1</td></tr></table> | P | 0 | 1 | 1 | 1 | 1 | 0 | 1 |
+| P                  | 0                                                                                                                   | 1 | 1 | 1 | 1 | 0 | 1 |   |   |
+| Control (reserved) | <table border="1"><tr><td>P</td><td>0</td><td>1</td><td>1</td><td>1</td><td>1</td><td>1</td><td>0</td></tr></table> | P | 0 | 1 | 1 | 1 | 1 | 1 | 0 |
+| P                  | 0                                                                                                                   | 1 | 1 | 1 | 1 | 1 | 0 |   |   |
+| Control (private)  | <table border="1"><tr><td>P</td><td>0</td><td>1</td><td>1</td><td>1</td><td>1</td><td>1</td><td>1</td></tr></table> | P | 0 | 1 | 1 | 1 | 1 | 1 | 1 |
+| P                  | 0                                                                                                                   | 1 | 1 | 1 | 1 | 1 | 1 |   |   |
+
+Figure 13/T.100 Control codes diagram showing bit patterns for value, status, reserved, and private control opcodes.
+
+CCITT-44190
+
+FIGURE 13/T.100  
+Control codes
+
+#### 6.5.1.2 Control (value)
+
+This control opcode defines the colour or grey scale accessed by subsequent drawing opcodes.
+
+#### 6.5.1.3 Control (status)
+
+This control opcode provides extension to a field of sub-commands.
+
+#### 6.5.1.4 Control (reserved)
+
+This control opcode is reserved for future control commands.
+
+#### 6.5.1.5 Control (private)
+
+This control opcode is reserved for use by terminal manufacturers to implement proprietary non-standard functions.
+
+### 6.5.2 Attributes
+
+6.5.2.1 A number of drawing attributes may be applied to the drawing commands. Attributes are defined by appropriate coded sequences as described below. Once an attribute is defined, it remains valid until the attribute is redefined.
+
+6.5.2.2 In the implementation of attributes, the level of sophistication and complexity is left to the discretion of the implementer.
+
+6.5.2.3 For the different drawing attributes and their feature levels see Recommendation F.300.
+
+### 6.5.3 Control (value)
+
+6.5.3.1 This opcode specifies the colour attribute or grey scale value of the drawings (or text) that follow. Whether the *control (value)* opcode and its associated data bytes contain colour or grey scale information, is predetermined by the *tonal* status sub-command (see § 6.5.4). The number of data bytes is variable and the sequence is terminated on the appearance of another opcode. Less significant bits for colour or grey scale information are truncated where they are not used. The bit assignments of the data bytes are shown in Figure 14/T.100 (only the 6-bit data portion of the 8-bit byte is shown).
+
+![Figure 14/T.100: Bit assignments for grey scale or colour attributes. The diagram shows two data bytes, 'First data byte' and 'Second data byte', each with 6 bits. The top part shows 'n levels of grey scale' with bits in order of decreasing significance. The bottom part shows 'Colour values in order of decreasing significance' with bits for Green, Red, and Blue specified in order of decreasing levels of intensity, two triplets per byte. The standard CCITT-44200 is referenced.](dbbc0baac7341cda76cc4f8355dce23f_img.jpg)
+
+The diagram illustrates the bit assignments for grey scale or colour attributes across two data bytes. The top section, labeled 'n levels of grey scale', shows the 'First data byte' and 'Second data byte' with bits in order of decreasing significance. The bottom section, labeled 'Colour values in order of decreasing significance', shows the 'First data byte' and 'Second data byte' with bits for Green, Red, and Blue specified in order of decreasing levels of intensity, two triplets per byte. The standard CCITT-44200 is referenced.
+
+Figure 14/T.100: Bit assignments for grey scale or colour attributes. The diagram shows two data bytes, 'First data byte' and 'Second data byte', each with 6 bits. The top part shows 'n levels of grey scale' with bits in order of decreasing significance. The bottom part shows 'Colour values in order of decreasing significance' with bits for Green, Red, and Blue specified in order of decreasing levels of intensity, two triplets per byte. The standard CCITT-44200 is referenced.
+
+FIGURE 14/T.100  
+Bit assignments for grey scale or colour attributes
+
+### 6.5.4 Control (status) and status sub-commands
+
+6.5.4.1 The *control (status)* opcode accesses a field of *status sub-commands* (columns 4, 5, 6 and 7) which define in detail all the modes of drawing operation or attributes. The sequence is always *control (status)* followed by a *status sub-command*, which in turn may or may not be further followed by parameter data bytes. Figure 15/T.100 gives the codings of the *status sub-commands*. Detailed definitions of the *status sub-commands* are given below.
+
+#### 6.5.4.2 (4/0) Clear-to-black
+
+This sub-command clears the entire display to black.
+
+#### 6.5.4.3 (4/1) Clear-to-transparent
+
+This sub-command clears the entire display of the screen to transparent. By transparent is meant that conventional television pictures can be mixed with Videotex images or text.
+
+#### 6.5.4.4 (4/2) *Clear-to-black and initialize*
+
+This sub-command clears the entire display to black and resets the terminal to the default mode.
+
+#### 6.5.4.5 (4/3) *Clear-to-current colour*
+
+This sub-command clears the entire display to the colour currently specified by the *control (value)* opcode sequence.
+
+#### 6.5.4.6 (4/4) *Domain (3 bytes)*
+
+The block of numerical data that follows an opcode contains 3 bytes. This is also the default condition.
+
+#### 6.5.4.7 (4/5) *Domain (4 bytes)*
+
+The block of numerical data that follows an opcode contains 4 bytes.
+
+#### 6.5.4.8 (4/6) *Domain (5 bytes)*
+
+The block of numerical data that follows an opcode contains 5 bytes.
+
+#### 6.5.4.9 (4/7) *Domain (6 bytes)*
+
+The block of numerical data that follows an opcode contains 6 bytes.
+
+#### 6.5.4.10 (4/8) *Drawing (blink-off)*
+
+Terminates the drawing (blink-on) status sub-command.
+
+##### 6.5.4.11(4/9) *Reserved*
+
+##### 6.5.4.12(4/10) *Drawing (blink-on) (or flashing)*
+
+This sub-command causes the drawing (or text) that follows to flash in a repetitive manner for the purpose of drawing attention. In general, an object of any colour or grey scale may be blinked, but in some implementations, blinking may be restricted.
+
+##### 6.5.4.13(4/11) *Reserved*
+
+##### 6.5.4.14(4/12) *Tonal (colour)*
+
+This sub-command designates that the *Control (value)* sequence carries colour information (see § 6.5.3).
+
+#### 6.5.4.15 (4/13) *Tonal (grey scale)*
+
+This sub-command designates that the *Control (value)* sequence carries grey scale information (see § 6.5.3).
+
+##### 6.5.4.16(4/14) *Reserved*
+
+##### 6.5.4.17(4/15) *Reserved*
+
+#### 6.5.4.18(5/0)    *Line (solid)* (See Note)
+
+This sub-command indicates that the drawing lines will be solid. This is also the default condition.
+
+#### 6.5.4.19 (5/1)    *Line (dotted)* (See Note)
+
+This sub-command indicates that the drawing lines will be dotted in texture.
+
+|                |                |                |                |    |                |   |   |   |                |                                 |                        |             |   |
+|----------------|----------------|----------------|----------------|----|----------------|---|---|---|----------------|---------------------------------|------------------------|-------------|---|
+|                |                |                |                |    | b <sub>7</sub> | 0 | 0 | 0 | 0              | 1                               | 1                      | 1           | 1 |
+|                |                |                |                |    | b <sub>6</sub> | 0 | 0 | 1 | 1              | 0                               | 0                      | 1           | 1 |
+|                |                |                |                |    | b <sub>5</sub> | 0 | 1 | 0 | 1              | 0                               | 1                      | 0           | 1 |
+|                |                |                |                |    |                | 0 | 1 | 2 | 3              | 4                               | 5                      | 6           | 7 |
+| b <sub>4</sub> | b <sub>3</sub> | b <sub>2</sub> | b <sub>1</sub> |    |                |   |   |   |                |                                 |                        |             |   |
+| 0              | 0              | 0              | 0              | 0  |                |   |   |   |                | Clear (to black)                | Line (solid)           | Text format |   |
+| 0              | 0              | 0              | 1              | 1  |                |   |   |   |                | Clear (to transparent)          | Line (dotted)          |             |   |
+| 0              | 0              | 1              | 0              | 2  |                |   |   |   |                | Clear (to black and initialize) | Line (dashed)          |             |   |
+| 0              | 0              | 1              | 1              | 3  |                |   |   |   |                | Clear (to current colour)       | Line (dot-dashed)      |             |   |
+| 0              | 1              | 0              | 0              | 4  |                |   |   |   |                | Domain (3 bytes)                | Fill                   |             |   |
+| 0              | 1              | 0              | 1              | 5  |                |   |   |   |                | Domain (4 bytes)                |                        |             |   |
+| 0              | 1              | 1              | 0              | 6  |                |   |   |   |                | Domain (5 bytes)                | Fill (black highlight) |             |   |
+| 0              | 1              | 1              | 1              | 7  |                |   |   |   |                | Domain (6 bytes)                |                        |             |   |
+| 1              | 0              | 0              | 0              | 8  |                |   |   |   |                | Drawing (blink-off)             |                        |             |   |
+| 1              | 0              | 0              | 1              | 9  |                |   |   |   |                |                                 |                        |             |   |
+| 1              | 0              | 1              | 0              | 10 |                |   |   |   |                | Drawing (blink-on)              |                        |             |   |
+| 1              | 0              | 1              | 1              | 11 |                |   |   |   |                |                                 |                        |             |   |
+| 1              | 1              | 0              | 0              | 12 |                |   |   |   |                | Tonal control (colour)          | Wait (timed)           |             |   |
+| 1              | 1              | 0              | 1              | 13 |                |   |   |   | Control status | Tonal control (grey)            | Wait (indefinite)      |             |   |
+| 1              | 1              | 1              | 0              | 14 |                |   |   |   |                |                                 |                        |             |   |
+| 1              | 1              | 1              | 1              | 15 |                |   |   |   |                |                                 |                        |             |   |
+
+CCITT-44210
+
+FIGURE 15/T.100  
+Control (status) and Status sub-commands assignment
+
+#### 6.5.4.20 (5/2) *Line (dashed)* (See Note)
+
+This sub-command indicates that the drawing lines will be dashed in texture.
+
+##### 6.5.4.21(5/3) *Line (dot-dashed)* (See Note)
+
+This sub-command indicates that the drawing lines will be dot-dashed in texture.
+
+*Note* – The line texture pattern is referenced to the absolute coordinate grid of the display screen so that the texture pattern aligns between drawing commands.
+
+##### 6.5.4.22(5/4) *Fill*
+
+This sub-command fills the enclosed area drawn in the colour specified by the current *Control (value)* sequence.
+
+##### 6.5.4.23(5/5) *Reserved*
+
+#### 6.5.4.24(5/6) *Fill (border highlight black)*
+
+This sub-command fills enclosed area drawn as 6.5.4.22 above and the circumscribing border is highlighted in black.
+
+##### 6.5.4.25(5/7) *Reserved*
+
+#### 6.5.4.26 (5/8) *Reserved*
+
+#### 6.5.4.27 (5/9) *Reserved*
+
+#### 6.5.4.28 (5/10) *Reserved*
+
+#### 6.5.4.29 (5/11) *Reserved*
+
+#### 6.5.4.30 (5/12) *Wait (timed)*
+
+This sub-command causes a delay of a specific time in processing and display. The length of wait is specified in tenths of a second, either by one associated parameter byte (6 bits for up to 6.3 s) or two parameter bites (12 bits for up to 6.8 m).
+
+#### 6.5.4.31(5/13) *Wait (indefinite)*
+
+This sub-command causes an indefinite wait. This may be achieved by the terminal responding with a *pause flow* control character (DC3 in C0 set) towards the computer. The wait is then terminated when the terminal sends a *resume data flow* character (DC 1 in C0 set).
+
+##### 6.5.4.32(5/14) *Reserved*
+
+##### 6.5.4.33(5/15) *Reserved*
+
+##### 6.5.4.34(6/O) *Text format*
+
+This sub-command has an associated data byte, which defines the text formats as follows:
+
+Bit b6 = 0: Free format, i.e. character strings are wrapped around on the right margin.
+
+Bit b6 = 1: Annotation format, i.e. character strings are in fixed positions on the screen.
+
+Bit b5 = 0: In free format, character strings are broken on a character boundary.
+
+Bit b5 = 1: In free format, character strings are broken on a word boundary.
+
+b4, b3: Defines character rotation as shown in Figure 16/T.100. Rotated strings of characters proceed in the direction of rotation. However, all other format controls on characters such as APB, APF, APD, APU and APR have their (unrotated) orientation meanings.
+
+b2, b1 = 0.0: Vertical spacing = 1.0
+
+b2, b1 = 0.1: Vertical spacing = 1.5
+
+b2, b1 = 1.0: Vertical spacing = 2.0
+
+b2, b1 = 1.1: Vertical spacing = 2.5
+
+![Diagram showing character rotation. A vertical line has '01' at the top and '11' at the bottom. A horizontal line has '10' on the left and '00' on the right. Four 'R' characters are positioned at the intersections: top-left, top-right, bottom-left, and bottom-right. Below the diagram is the text 'CCITT-44220'.](e64c7b989e5bdb2708cd7aefd18b06e1_img.jpg)
+
+Diagram showing character rotation. A vertical line has '01' at the top and '11' at the bottom. A horizontal line has '10' on the left and '00' on the right. Four 'R' characters are positioned at the intersections: top-left, top-right, bottom-left, and bottom-right. Below the diagram is the text 'CCITT-44220'.
+
+FIGURE 16/T.100  
+Character rotation
+
+## 6.6 Default conditions
+
+6.6.1 The default conditions of the attributes for the alphageometric coding scheme are summarized below:
+
+|                     |                                                                                                                                                                                      | Reference  |
+|---------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------|
+| 1) Control (value): | White                                                                                                                                                                                | § 6.5.3    |
+| 2) Tonal control:   | Tonal (colour)                                                                                                                                                                       | § 6.5.4.14 |
+| 3) Domain:          | 3 bytes (9 bits)                                                                                                                                                                     | § 6.5.4.6  |
+| 4) Drawing:         | Blink-off                                                                                                                                                                            | § 6.5.4.10 |
+| 5) Line control:    | Solid line                                                                                                                                                                           | § 6.5.4.18 |
+| 6) Fill:            | Solid fill<br>(no highlight)                                                                                                                                                         | § 6.5.4.22 |
+| 7) Text format:     | a) Free format                                                                                                                                                                       | § 6.5.4.34 |
+|                     | b) Break on character boundary                                                                                                                                                       |            |
+|                     | c) No rotation                                                                                                                                                                       |            |
+|                     | d) Vertical spacing = 1.0                                                                                                                                                            |            |
+|                     | <div style="display: flex; align-items: center;"> <div style="font-size: 3em; margin-right: 10px;">}</div> <div>             with bits 1<br/>to 6 set to "0"           </div> </div> |            |
+
+# 7 Alpha-dynamically redefinable character sets (DRCS) option
+
+## 7.1 General
+
+7.1.1 A DRCS is a set of characters whose shapes are sent from the data-base and down-loaded via the line. It may be used to represent alphabetic characters, special symbols, or picture element symbols for constructing fine graphics. Once loaded, the DRCS are regarded as members of a library that can be designated by appropriate ESC sequences as G0, G1, G2, G3 sets. Several schemes for the DRCS option are possible. One scheme is described in § 7 in the context of a general architecture. When used in its alphanumeric mode DRCS may be employed as a part of the alphabetic representations of any other Videotex option and in that case, the attributes associated with that option are to be used.
+
+## 7.2 General architecture for down-loading DRCS
+
+### 7.2.1 Initiation
+
+The down-loading process is initiated by a designation and invocation sequence. This sequence is followed by one or more of the following functions.
+
+### 7.2.2 *Identification of character set (ICS)*
+
+This function must immediately follow the initiating sequence. It identifies the *escape* sequence used for the designation of the character set.
+
+### 7.2.3 *Select coding method (SCM)*
+
+This function defines the type of coding used to describe the DRCS character.
+
+### 7.2.4 *Select dot composition (SDC)*
+
+This function defines the number of bits horizontally and vertically in a character matrix, the number of bits per pixel, the number of grey scale levels and the number of colours accessible within a character position.
+
+### 7.2.5 *Pattern transfer (PT)*
+
+This is the active part of the down-loading process. It defines the code location of the first character and provides instructions and data to draw characters. It may also incorporate an error checking procedure.
+
+### 7.2.6 *Down-loading termination procedure (DLT)*
+
+The down-loading process is terminated by a specific procedure, which may include acknowledgement.
+
+## 7.3 *A possible coding scheme for the DRCS option*
+
+### 7.3.1 *Initiating sequence*
+
+The initiating sequence is ESC  $F_s$  followed by  $x$  bytes indicating the length of the loading data block, where  $x$  is for further study.
+
+### 7.3.2 *Termination procedure*
+
+The down-loading process is terminated by means of counting the length of the loading data block. See §7.3.1.
+
+### 7.3.3 *Designation and invocation of loaded DRCS*
+
+7.3.3.1 Once loaded into the terminal, the DRCS is placed into a library. This library is used in the context of ISO 2022 in the 7-bit environment as implemented in earlier sections. Before invoking the designated DRCS, it is required to designate a C1 set to be associated with it. For the scheme described herein any of the C1 sets (to be registered) that are defined in §§ 2.2 and 2.3 may be used.
+
+7.3.3.2 The designation sequence will be of the form ESC  $I_1$ , 2/0, ( $I_3 \dots I_n$ ) F.  $I_1$  will be 2/8, 2/9, . . . or 2/15.  $I_3 \dots I_n$  are optional, and if present together with F, will identify the set. Means for associating the designating sequence with the process of defining the character shapes will be for further study.
+
+# 8 **Alphaphotographic option**
+
+8.1 The alphaphotographic option is used to render an image by the transmission and display of individual picture elements.
+
+8.2 This option may include both continuous-tone images such as pictures of faces, etc., as well as pattern-oriented techniques for the display of pictures, including graphics, Latin and non-Latin characters for text, etc. The system features and attributes include colour and monochrome.
+
+8.3 The detailed system proposals are for further study.
+
+# 9 Service enhancements
+
+## 9.1 Introduction
+
+9.1.1 Many Administrations are offering or considering the introduction of a Videotex service, and it is recognized that this Recommendation may influence some of their decisions. While the other sections of this Recommendation contain details of those aspects of an international Videotex service that could be agreed upon, this § 9 identifies certain potential enhancements (features or attributes) that some Administrations believe need to be considered in future developments.
+
+9.1.2 It is recognized that some of these potential enhancements may only exist on national Videotex services, while others may have international application. However, an enhancement that begins on a national service only could become international in the future. Therefore, it is considered desirable to have international coordination of future enhancements.
+
+## 9.2 General
+
+9.2.1 The growth of international Videotex services during the years following the publication of this Recommendation will be greatly affected by the specific specifications contained in the other parts of this Recommendation. However, some Administrations believe that experiments with and/or implementation of certain enhancements will allow the development of an international service that provides a range of capabilities that will maximize the desirability and utilization of Videotex service.
+
+9.2.2 Some of the potential enhancements to Videotex service, national or international, are presented in the following. This is for the purpose of identifying to interested Administrations those enhancements that warrant serious consideration in the view of the CCITT, but which presently lack enough details to obtain the full agreement of all Administrations.
+
+9.2.3 The enhancements have been grouped into three categories in order to assist the reader in understanding the application of each individual enhancement (which may be referred to by some Administrations as attributes or features or some other descriptive phrase) and to prompt an orderly investigation of them:
+
+- a) display-related enhancements;
+- b) transmission-oriented enhancements;
+- c) system level enhancements.
+
+## 9.3 Display related enhancements
+
+9.3.1 Most of the currently planned and/or offered services utilize images created with only eight colours, which are formed by the various combinations (on or off) of three primary colours – red, green and blue. Limiting Videotex to eight colours is an unnecessary restriction, since the electronic emission devices controlling the red, green and blue colours can be caused to have more than just the two states of on or off. For example, with just eight different states or levels, a potential of 512 colours exist. Additionally, for those services that use a matrix-oriented screen (e.g. a mosaic graphic mode), different colours could be identified for foreground symbols to those for background areas.
+
+9.3.2 The ability to simulate motion (i.e. animation) is a potential enhancement that can be achieved by several means. These include:
+
+- a) alternating between slightly different display frames stored in the terminal;
+- b) dynamically altering the colour of portions of the display image, making them appear or disappear by redefining the colour table (an image disappears when its colour is set to the same colour as the surrounding area);
+- c) execution of a resident program to redefine the image at a controlled rate.
+
+9.3.3 The flashing of symbols or areas of the display has typically been limited to changing the foreground symbol (in the case of a matrix-oriented screen) to the background colour, momentarily, or some other single-state change. An enhanced flashing capability could allow for different rates of change and for various conditions associated with each change (e.g. colour X to colour Y, rather than foreground colour to background colour or foreground colour to black).
+
+9.3.4 Different pictorial (text and graphic) symbols may be developed that extend the repertoire of a Videotex service. This may be a fixed extension defined in the terminal memory, or can be a modification to the existing memory by downloading from the data base. The range of extended symbols includes different fonts of existing symbols, smoothed mosaic graphics, or other unique symbols.
+
+## 9.4 *Transmission oriented enhancements*
+
+9.4.1 The exchange of information directly between terminals, without communicating with a Videotex service may be permitted by some Administrations as an enhanced capability, and could be of value to the users of Videotex terminals. Such a capability would require the existence of control functions that might not, otherwise, be available in some terminals that utilize certain existing or planned national Videotex services, but this should not cause any incompatibilities with such services.
+
+9.4.2 The optimization of the coded character stream for maximum data rate is a valuable enhancement. This might be accomplished by utilizing an 8-bit per word coding format rather than the 7-bit per word format currently planned by most Administrations, coupled with a related decision on the line or link level protocol selected. The selection of an 8-bit per word format could permit a more efficient transmission of data.
+
+In addition, such techniques as run-length-encoding might be specified in the Recommendation to reduce the transmission of unnecessary or redundant data. The choice of higher speed modems/circuits is also considered by some Administrations as a way to optimize the transfer of data within or between Videotex services.
+
+9.4.3 For some applications of a Videotex service, sophisticated error detection and correction schemes may be required and should be considered with other transmission-oriented enhancements on future Videotex services.
+
+## 9.5 *System level enhancements*
+
+9.5.1 An enhancement seriously considered by some Administrations is the provision of a Videotex service that provides visual information, augmented by audio information. This capability could permit access by a terminal to visual-only information in a data base, and to visual/audio information in the same or other data base. The audio information might be associated with the visual information, or treated separately, or even alternately, depending upon the implementation. The audio information might be analogue or digitally encoded or handled as a composite signal.
+
+9.5.2 The provisioning of peripheral input/output devices associated with the Videotex terminal is an important enhancement for future services. These could include magnetic storage devices for recording visual/audio information as received by the terminal, or recorded locally by the terminal for subsequent transmission to a data base or other terminal. Various hard copy printing devices could also be provided, with their design based upon the specific visual capabilities of the terminal, e.g. degree of resolution and colour of the image on the display screen.
+
+# 10 **Line and end-to-end protocols**
+
+10.1 The purpose of § 10 is to describe the protocols needed for international Videotex transactions. Section 10 contains an introduction only. Detailed consideration is left for further study.
+
+10.2 The transfer of information from a data base of one service to a user of another service may be split up into two parts:
+
+- a) the information transfer from one service to another;
+- b) the information transfer from the service to the user.
+
+## 10.3 *Line protocols*
+
+### 10.3.1 *Line protocols between services*
+
+10.3.1.1 The international line between national data base computers must be able to transmit transparent coding schemes identified in this Recommendation and accept the protocols of § 10.4.
+
+### 10.3.2 *Line protocols between service and user*
+
+#### 10.3.2.1 The following protocol functions should be studied:
+
+PF1: Start of coded data starts a sequence of data to be understood as textual information (could be coded as STX).
+
+PF2: Start of prefix causes the following bytes to be understood as a prefix containing framing information including codes for error check and/or correction (could be coded as SOH).
+
+PF3: End of coded data ends a sequence of data to be understood as textual information (could be coded as ETX).
+
+PF4: End of frame. Ends a frame of data and requests for reverse transmission and give an answer (could be coded as ETB).
+
+PF5: Answer given in case of error free reception or when error correction is possible (could be coded as ACK).
+
+PF6: Answer given in case of errors when no error correction is possible (could be coded as NAK).
+
+10.3.2.2 It is noted that TC1 to TC10 (SOH to ETB of Recommendation T.50) are intended to control the transmission of information over transmission networks. The use of these functions may therefore not be used as part of the information stream from one service to another.
+
+10.3.2.3 The use of protocol functions is for further study.
+
+## 10.4 *Protocols for communication between services on the application level*
+
+### 10.4.1 *General*
+
+10.4.1.1 International exchange of information between national Videotex services may be sent in blocks, here called messages. For efficient use of networks and communication equipment it is important to design the messages to minimize the capacity needed for applications that are frequently used in Videotex services.
+
+### 10.4.2 *Types of message elements*
+
+10.4.2.1 A complete message is composed of message elements. Each element contains an element identifier, a data field and an indication of element length (explicit or implicit).
+
+#### 10.4.2.2 *Transmit a standardized function*
+
+Codes for functions may be different from the character sequences, sent by the user.
+
+#### 10.4.2.3 *Transmit a service message*
+
+A service message is a frame that is transmitted to the subscriber, without erasing the screen, moving the active position of the cursor, or changing the contents of the previous display.
+
+#### 10.4.2.4 *Transmit a service message code*
+
+The proper service message is generated by the receiving system and transmitted to the subscriber.
+
+#### 10.4.2.5 *Transmit a frame*
+
+Billing and other additional information is to be transmitted together with the frame.
+
+#### 10.4.2.6 *Transmit data block*
+
+By data is meant all types of data that are not listed under separate items, e.g. software. It is necessary to transmit block length when transmitting transparent data.
+
+#### 10.4.2.7 *Transmit field description*
+
+A field description is a list of positions on the screen, where an application program expects additional information to be filled in, either by the user or by the application program itself. It includes also format and type of information which allows simple syntax control in the host computer.
+
+Three formats are recognized; strings, which means any combination of graphical characters including space, integers (0-9), and free format.
+
+A field may be of input and/or output type. An input field is a field where the information is user originated. An output field is a field in which the information is filled in by the application program.
+
+#### 10.4.2.8 *Transmit a user message to an application*
+
+A user message is the data that is filled in by the user according to a field description. It is sent to the external computer. The transmission is initiated either by a send-function if it is available, or when all input fields are filled. The use of a delimiter causes the rest of the field to be filled with spaces. If a delimiter is used in the first position of a combined input and output field, the contents remain unchanged.
+
+#### 10.4.2.9 *Transmit an application message*
+
+An application message is a block of data to be filled into the output fields, defined by a field description. It may be sent either in the same message as the field description, or after.
+
+#### 10.4.2.10 *Request information on terminal capability*
+
+(For further study.)
+
+#### 10.4.2.11 *Transmit information on terminal capability*
+
+(For further study.)
+
+#### 10.4.2.12 *Error condition element*
+
+The detection of contradicting information in a system will result in an error condition message to the other system, e.g. data with a format different to the corresponding field description. The entire message causing the error will be ignored, and it is the responsibility of its transmitting system to handle the error properly.
+
+## 10.5 *User to data base protocol*
+
+10.5.1 In order to use Videotex service, a user must be able to generate a set of functions which enables him to access and use different applications. A set of user functions is listed in Recommendation F.300.
+
+10.5.2 The minimum set of characters to code these functions contains the digits 0-9 and two other symbols. For some applications however, the generation of alphanumeric as well as pictorial and attribute information and other control characters may be needed.
+
+10.5.3 Although it is desirable that all Videotex services employ the same keying sequences and visual identifiers for these functions, there are historical reasons why there will be different manners of coding the same user functions.
+
+10.5.4 Accessing the national service of another country using an international connection between services is possible, if the user obeys the function coding rules of the service of the other country. It is, however, possible that the local data bank may be able to translate the local keying sequence into the appropriate command in a national service level (see § 10.4.2.4). This subject is left for further study.
+
+# 11 Interworking with other services
+
+## 11.1 *Telex-Videotex*
+
+11.1.1 Telex is a message transfer service and therefore, interworking between telex and Videotex should be limited to the exchange of alphanumeric text between terminal equipments.
+
+11.1.2 Only the graphic characters of the Videotex graphic character repertoire corresponding to International Telegraph Alphabet No. 2 should be used to compose messages.
+
+11.1.3 The message format will be limited by the Videotex page format.
+
+11.1.4 Telex can only display alphanumeric information without the capability of displaying the other attributes of Videotex.
+
+## 11.2 *Teletex- Videotex*
+
+### 11.2.1 *Graphic character repertoire*
+
+11.2.1.1 The Teletex and Videotex graphic repertoires are largely identical. The following fallback representations of Videotex characters (see Table 2/T.100), may be transcoded at a Videotex-Teletex interworking facility.
+
+TABLE 2/T.100
+
+| Identifier   | Videotex character | Fallback representation |      |
+|--------------|--------------------|-------------------------|------|
+| SM30         | ←                  | <                       | SA03 |
+| SM31         | →                  | >                       | SA05 |
+| SM32         | ↑                  | !                       | SP03 |
+| SM33         | ↓                  | !                       | SP02 |
+| SP19         | ‘                  | ’                       | SP05 |
+| SP20         | ’                  | ’                       | SP05 |
+| SP21         | “                  | ”                       | SP04 |
+| SP22         | ”                  | ”                       | SP04 |
+| SM12         | —                  | —                       | SP10 |
+| MG01 to MG63 | Block graphics     | /                       | SP12 |
+
+11.2.1.2 For Teletex terminals having the ability to present the Videotex character repertoire in its entirety, the need for this transcoding disappears. Therefore, on initial call establishment, a determination of the terminal display/printing capabilities must be made by handshaking.
+
+### 11.2.2 *Control functions*
+
+11.2.2.1 Transcoding of the Videotex attribute control functions is for further study.
+
+### 11.2.3 *Format*
+
+11.2.3.1 Interworking between Videotex and Teletex will be limited to the Videotex display frame format.
+
+## 11.3 *Videotex-facsimile*
+
+(For further study.)
+
+## 11.4 *Videotex-Teletex*
+
+(For further study.)
+
+(to Recommendation T.100)
+
+## Part of the code extension scheme of ISO 2022
+
+![Diagram of the code extension scheme of ISO 2022 showing the flow from control and graphic repertoires through various ESC sequences to specific control and graphic sets.](8e80de0cac529b2c3775d677c5203133_img.jpg)
+
+The diagram illustrates the code extension scheme of ISO 2022, showing the flow from various repertoires through specific escape sequences to control and graphic sets.
+
+**Control Repertoire and Extension:**
+
+- Control repertoire** (stack of rectangles) is linked via **ESC 2/1 (F)** to a **7-bit set in use** (dashed box containing **C0** and **C1**).
+- Extended control repertoire** (stack of rectangles) is linked via **ESC 2/2 (F)** to the **7-bit set in use**.
+- A box indicates: **Single additional control functions represented by ESC (F<sub>s</sub>) or ESC 2/3 (F)**.
+- A box indicates: **Specific control functions within C1 set are represented by ESC (F<sub>o</sub>) sequence**.
+
+**Graphic Sets and Repertoires:**
+
+- Invocation of graphic sets** (SS1, SS2, SS3) points to **G0**, **G1**, **G2**, and **G3** (stacks of rectangles).
+- Designation of graphic sets** (ESC 2/6 (F) to ESC 2/14 (F)) points to the graphic sets.
+- Multiple byte graphic repertoire** (stack of rectangles) is linked to the graphic sets.
+- Graphic repertoire** (stack of rectangles) is linked to the graphic sets.
+
+**7-bit set in use details:**
+
+- C0** and **C1** are shown as specific control sets.
+- SS1**, **SS2**, and **SS3** are shown as specific graphic sets.
+
+**ESC Sequences:**
+
+- ESC 2/1 (F)**: Control repertoire to 7-bit set in use.
+- ESC 2/2 (F)**: Extended control repertoire to 7-bit set in use.
+- ESC 2/3 (F)**: Single additional control functions.
+- ESC 2/6 (F)** to **ESC 2/14 (F)**: Designation of graphic sets.
+
+CCITT-35951
+
+Diagram of the code extension scheme of ISO 2022 showing the flow from control and graphic repertoires through various ESC sequences to specific control and graphic sets.
+
+# ANNEX B
+
+(to Recommendation T.100)
+
+## Repertoire of graphic characters
+
+## B.1 *General*
+
+B.1.1 This annex defines the basic graphic repertoire of the international Videotex service. This repertoire consists of the total range of non-pictorial symbols, which may be communicated between Videotex services and terminals by means of coded character sets for Latin-alphabet based languages.
+
+B.1.2 The repertoire of graphic characters defined in this part of the Recommendation consists of:
+
+- a) Latin alphabetic characters, listed in § B.2, which comprise:
+  - the 52 small and capital letters of the basic Latin alphabet,
+  - combinations of basic Latin letters and diacritical marks,
+  - special alphabetic characters, which are neither basic Latin letters nor combinations of basic Latin letters and diacritical marks,
+- b) non-alphabetic characters, listed in § B.3, which comprise decimal digits, currency signs, punctuation marks, arithmetic signs and miscellaneous symbols that have individual special meanings.
+
+B.1.3 A diacritical mark has no meaning as an individual character but is used only in combination with a basic Latin letter to form an accented letter or an umlaut.
+
+B.1.4 The repertoire of graphic characters defined in this part of the Recommendation contains a limited set of accented letters and umlauts.
+
+## B.2 *Latin alphabetic characters*
+
+B.2.1 The repertoire of Latin alphabetic characters is identical to that specified in § 3.2.2 of Recommendation T.61 (for the Teletex basic repertoire of graphic characters).
+
+## B.3 *Non-alphabetic characters*
+
+B.3.1 Decimal digits (0 to 9), currency signs, arithmetic signs, subscripts and superscripts and fractions are as specified in §§ 3.2.3.1, 3.2.3.2, 3.2.3.4, 3.2.3.5 and 3.2.3.6 of Recommendation T.61.
+
+B.3.2 Punctuation marks are as specified in § 3.2.3.3 of Recommendation T.61, with the exclusion of SP09 (low line) and the addition of SP19 to SP22, which are as shown in Table B-1/T.100.
+
+B.3.3 Miscellaneous symbols are as shown in Table B-2/T.100.
+
+B.3.4 The lists in Tables B-1/T.100 and B-2/T.100 are composed as described in the following.
+
+The first column contains the identifier of each character, assigned in accordance with the identification system explained in Annex C of Recommendation T.61.
+
+The second column presents the graphical representation of the character.
+
+The third column specifies the name or the description of the character.
+
+TABLE B-1/T.100
+
+## **Punctuation marks**
+
+| Identifier | Graphic | Name or description         |
+|------------|---------|-----------------------------|
+| SP19       | ‘       | Single quotation mark left  |
+| SP20       | ’       | Single quotation mark right |
+| SP21       | “       | Double quotation mark left  |
+| SP22       | ”       | Double quotation mark right |
+
+*Note* – In Videotex (and Teletex), *quotation mark*, *apostrophe* and *comma* are independent characters that cannot have the meaning of diacritical marks.
+
+TABLE B-2/T.100
+
+## **Miscellaneous symbols**
+
+| Identifier | Graphic | Name or description          |
+|------------|---------|------------------------------|
+| SM01       | #       | Number sign                  |
+| SM02       | %       | Percent sign                 |
+| SM03       | &       | Ampersand                    |
+| SM04       | *       | Asterisk                     |
+| SM05       | @       | Commercial at                |
+| SM12       | —       | Horizontal bar               |
+| SM13       |         | Vertical line                |
+| SM17       | μ       | Micro sign                   |
+| SM18       | Ω       | Ohm sign                     |
+| SM19       | °       | Degree sign                  |
+| SM20       | ♂       | Ordinal indicator, masculine |
+| SM21       | ♀       | Ordinal indicator, feminine  |
+| SM24       | §       | Section sign                 |
+| SM25       | ¶       | Paragraph sign, pilcrow      |
+| SM26       | •       | Middle dot                   |
+| SM30       | ←       | Leftward arrow               |
+| SM31       | →       | Rightward arrow              |
+| SM32       | ↑       | Upward arrow                 |
+| SM33       | ↓       | Downward arrow               |
\ No newline at end of file
diff --git a/marked/T/T-REC-T.105-199411-I_PDF-E/01e00200a536673d6cd0e6d8705047a0_img.jpg b/marked/T/T-REC-T.105-199411-I_PDF-E/01e00200a536673d6cd0e6d8705047a0_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..838e8b3783c17be1515bb35e0f9a4d59b71743bb
--- /dev/null
+++ b/marked/T/T-REC-T.105-199411-I_PDF-E/01e00200a536673d6cd0e6d8705047a0_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:afd277cd49f945a48ecc3752f248482f61514df0e0baa145b2d1dfea1430ddcc
+size 30714
diff --git a/marked/T/T-REC-T.105-199411-I_PDF-E/0549ab3c68ad94e7e1bb6ec6aa6b5373_img.jpg b/marked/T/T-REC-T.105-199411-I_PDF-E/0549ab3c68ad94e7e1bb6ec6aa6b5373_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..f3d95a325b9e6ec92ed23704a457a2c8d027473b
--- /dev/null
+++ b/marked/T/T-REC-T.105-199411-I_PDF-E/0549ab3c68ad94e7e1bb6ec6aa6b5373_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:2c241947a490d2e03b6813c2a536e69712c6b27036cd63513c3b5e47597f3f8b
+size 30948
diff --git a/marked/T/T-REC-T.105-199411-I_PDF-E/0adfaa8c2562a9fe3a8a96165d7d59a3_img.jpg b/marked/T/T-REC-T.105-199411-I_PDF-E/0adfaa8c2562a9fe3a8a96165d7d59a3_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..705b9d99dd141fd60c65d9a47f68fb20ac31b937
--- /dev/null
+++ b/marked/T/T-REC-T.105-199411-I_PDF-E/0adfaa8c2562a9fe3a8a96165d7d59a3_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:623ea32d4f994131d945bf1ff9d7e722ee0d9598873a59f678d8682fef433b45
+size 30300
diff --git a/marked/T/T-REC-T.105-199411-I_PDF-E/15de63f0b5df62e6ab9164f2a72e2e33_img.jpg b/marked/T/T-REC-T.105-199411-I_PDF-E/15de63f0b5df62e6ab9164f2a72e2e33_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..a86fdf5e3db31502731c55d36b3600f85892b525
--- /dev/null
+++ b/marked/T/T-REC-T.105-199411-I_PDF-E/15de63f0b5df62e6ab9164f2a72e2e33_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:60589a108d09ffd34a085a7d98e788fc2cfc3ca5fb359438041877799e4c98e2
+size 202052
diff --git a/marked/T/T-REC-T.105-199411-I_PDF-E/18d7d8de298d79e7bc87af5217f11203_img.jpg b/marked/T/T-REC-T.105-199411-I_PDF-E/18d7d8de298d79e7bc87af5217f11203_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..c80b24eb6e6715655ef7456e5f6bb56df32ae1f7
--- /dev/null
+++ b/marked/T/T-REC-T.105-199411-I_PDF-E/18d7d8de298d79e7bc87af5217f11203_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:096d4c56efebe7909e97ef4b886d8735e0dd92a86e8086d501a605967cbe3be2
+size 29330
diff --git a/marked/T/T-REC-T.105-199411-I_PDF-E/18dbea0ac6b7ad13e47afda3ddd53b64_img.jpg b/marked/T/T-REC-T.105-199411-I_PDF-E/18dbea0ac6b7ad13e47afda3ddd53b64_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..ed59b606cd895a56981178fbcc3436e068879040
--- /dev/null
+++ b/marked/T/T-REC-T.105-199411-I_PDF-E/18dbea0ac6b7ad13e47afda3ddd53b64_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:44bfd123c85ac67cd32379723545895dbe554a57af8aa44b5097511937169ef4
+size 17466
diff --git a/marked/T/T-REC-T.105-199411-I_PDF-E/1c79f31a718d63814feb28ab46f64f19_img.jpg b/marked/T/T-REC-T.105-199411-I_PDF-E/1c79f31a718d63814feb28ab46f64f19_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..8f7b16cead44ff290a111039a07d203152c12910
--- /dev/null
+++ b/marked/T/T-REC-T.105-199411-I_PDF-E/1c79f31a718d63814feb28ab46f64f19_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:d7ebac8b70edcba539848fd7b879c6c2ebfeb3e48a4913b40579cc96ee11d8fd
+size 16000
diff --git a/marked/T/T-REC-T.105-199411-I_PDF-E/24ba47df8be44ae91945d88ce2232df5_img.jpg b/marked/T/T-REC-T.105-199411-I_PDF-E/24ba47df8be44ae91945d88ce2232df5_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..abfa15df9d6ea3a28456031309cc2d0a0011e290
--- /dev/null
+++ b/marked/T/T-REC-T.105-199411-I_PDF-E/24ba47df8be44ae91945d88ce2232df5_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:41870633910b396949a688d0783b1aed494c08ca976e37eebe87992684881cd1
+size 13315
diff --git a/marked/T/T-REC-T.105-199411-I_PDF-E/2b60ebe01f77d22e53da1fbe73083b01_img.jpg b/marked/T/T-REC-T.105-199411-I_PDF-E/2b60ebe01f77d22e53da1fbe73083b01_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..f1720b2466348c7585b582d9595e4449c2857cee
--- /dev/null
+++ b/marked/T/T-REC-T.105-199411-I_PDF-E/2b60ebe01f77d22e53da1fbe73083b01_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:821467a1588f1d259e876df14e32ca5bb9ced9f253ef15ae7a9cb79df5abd4b7
+size 15840
diff --git a/marked/T/T-REC-T.105-199411-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/T/T-REC-T.105-199411-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..d16eb76ba0390338c65f628107f6a2486a061547
--- /dev/null
+++ b/marked/T/T-REC-T.105-199411-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:7c0b073d0d2174a99959ffe7e94c664a35513f8171cbf88b27aaa9e07cd83685
+size 8315
diff --git a/marked/T/T-REC-T.105-199411-I_PDF-E/364054adcd1b427fa259450e006c6b38_img.jpg b/marked/T/T-REC-T.105-199411-I_PDF-E/364054adcd1b427fa259450e006c6b38_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..8b6573bbe395434d07ae3d18407f3f472061ef19
--- /dev/null
+++ b/marked/T/T-REC-T.105-199411-I_PDF-E/364054adcd1b427fa259450e006c6b38_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:e40c20dab02e7056dccd8e4b3c61b7bcf909f74ce744e8c38a88be99eeefe34f
+size 43837
diff --git a/marked/T/T-REC-T.105-199411-I_PDF-E/4464bc13e0077cb62ad54bf6c7473755_img.jpg b/marked/T/T-REC-T.105-199411-I_PDF-E/4464bc13e0077cb62ad54bf6c7473755_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..b9bf8dacccbd9aeaf973cca3b8744b45325a4893
--- /dev/null
+++ b/marked/T/T-REC-T.105-199411-I_PDF-E/4464bc13e0077cb62ad54bf6c7473755_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:cc70381e5e3735ec205c12cc3e3d07c8b8c752a4ff8fc12e9b32efa9be01de80
+size 57058
diff --git a/marked/T/T-REC-T.105-199411-I_PDF-E/5cc4a2ef554f31ea0577731931007fff_img.jpg b/marked/T/T-REC-T.105-199411-I_PDF-E/5cc4a2ef554f31ea0577731931007fff_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..aba08de6bf7dccc48f8315295784c4464c3cff77
--- /dev/null
+++ b/marked/T/T-REC-T.105-199411-I_PDF-E/5cc4a2ef554f31ea0577731931007fff_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:ae91c972bcb33c015ec1ca295f804c2453f9b97130faaf8b3125f70815bd10fc
+size 31301
diff --git a/marked/T/T-REC-T.105-199411-I_PDF-E/71f0fd23b2f06b621ba89a65ee3c284c_img.jpg b/marked/T/T-REC-T.105-199411-I_PDF-E/71f0fd23b2f06b621ba89a65ee3c284c_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..9bd206211dd119c6b4e27a4ae1c62ee6609a13bd
--- /dev/null
+++ b/marked/T/T-REC-T.105-199411-I_PDF-E/71f0fd23b2f06b621ba89a65ee3c284c_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:53e01ab2b106197fbe8b4a5c2dea10b6475ab950016b2637cbb2ce6acfab061f
+size 24139
diff --git a/marked/T/T-REC-T.105-199411-I_PDF-E/76b0cd79baaedd942af4dc42f2e764b8_img.jpg b/marked/T/T-REC-T.105-199411-I_PDF-E/76b0cd79baaedd942af4dc42f2e764b8_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..a3ae60be1d3a099150a0206089c62ece7ee84054
--- /dev/null
+++ b/marked/T/T-REC-T.105-199411-I_PDF-E/76b0cd79baaedd942af4dc42f2e764b8_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:342fac1cd7de8b6a1730ddd7747e1335cf1396efdb9ee5c609d1966230387347
+size 66998
diff --git a/marked/T/T-REC-T.105-199411-I_PDF-E/8f7c0bf0c75a31fee6b0c7392ff57c39_img.jpg b/marked/T/T-REC-T.105-199411-I_PDF-E/8f7c0bf0c75a31fee6b0c7392ff57c39_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..f62c92f469496f9196f4cf43cc9825ea2da829e9
--- /dev/null
+++ b/marked/T/T-REC-T.105-199411-I_PDF-E/8f7c0bf0c75a31fee6b0c7392ff57c39_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:efd0c87d02738af40f0a2be879ce132ff05e72aa23143ccf3aad1fb594dd9628
+size 26770
diff --git a/marked/T/T-REC-T.105-199411-I_PDF-E/a7c51c18111139f9aca2805114108565_img.jpg b/marked/T/T-REC-T.105-199411-I_PDF-E/a7c51c18111139f9aca2805114108565_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..02f0da5feb456a7a93388def1d63b91b219245fc
--- /dev/null
+++ b/marked/T/T-REC-T.105-199411-I_PDF-E/a7c51c18111139f9aca2805114108565_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:f0b5ae2be1c9a49a4d2f7afd210dd3afbb6951d7199886316ef2cf35784b2256
+size 44663
diff --git a/marked/T/T-REC-T.105-199411-I_PDF-E/af6c3f383ddc0c142cdd7e186cc78199_img.jpg b/marked/T/T-REC-T.105-199411-I_PDF-E/af6c3f383ddc0c142cdd7e186cc78199_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..19a5f00684716290dde176aefce8136cb4ff1136
--- /dev/null
+++ b/marked/T/T-REC-T.105-199411-I_PDF-E/af6c3f383ddc0c142cdd7e186cc78199_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:5117f3fe40921116837be505a8b5db1bbe1e1cfcaf6f8b081dc043732999d1ac
+size 160284
diff --git a/marked/T/T-REC-T.105-199411-I_PDF-E/afd9ce64c136f2090b978ea5f3ef9d8d_img.jpg b/marked/T/T-REC-T.105-199411-I_PDF-E/afd9ce64c136f2090b978ea5f3ef9d8d_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..3c903fdd61691bd0712b5ad78ccf73af19eccf25
--- /dev/null
+++ b/marked/T/T-REC-T.105-199411-I_PDF-E/afd9ce64c136f2090b978ea5f3ef9d8d_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:095e82a722ed60fadd8cfadc1308f81a4130e7dff4852cf66b53bf66336ed50b
+size 29045
diff --git a/marked/T/T-REC-T.105-199411-I_PDF-E/b1784a5cbeeb3d9fb9e60b333019c721_img.jpg b/marked/T/T-REC-T.105-199411-I_PDF-E/b1784a5cbeeb3d9fb9e60b333019c721_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..d8a46db5ddd363d5ac9289fdee11a51af58e062d
--- /dev/null
+++ b/marked/T/T-REC-T.105-199411-I_PDF-E/b1784a5cbeeb3d9fb9e60b333019c721_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:137c25ad4828af6c80bbe5a6bc5a57d7bc48e74ba904bf250217f95cdcce11dd
+size 27402
diff --git a/marked/T/T-REC-T.105-199411-I_PDF-E/b4f6d3668f7e851eaff07ccf26001623_img.jpg b/marked/T/T-REC-T.105-199411-I_PDF-E/b4f6d3668f7e851eaff07ccf26001623_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..2f9f4e5dba97ae3f09c38ebf1e9e42925a603779
--- /dev/null
+++ b/marked/T/T-REC-T.105-199411-I_PDF-E/b4f6d3668f7e851eaff07ccf26001623_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:4552e81f4a3c50564a357829707ea7a6ec48a75909b2452ebb04df9ed8eb074b
+size 23582
diff --git a/marked/T/T-REC-T.105-199411-I_PDF-E/b87818c8505328b198d035761bbc3f2d_img.jpg b/marked/T/T-REC-T.105-199411-I_PDF-E/b87818c8505328b198d035761bbc3f2d_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..277e5c51c26cd28686d7e8e034be1a5d796f25cb
--- /dev/null
+++ b/marked/T/T-REC-T.105-199411-I_PDF-E/b87818c8505328b198d035761bbc3f2d_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:dcb0e43150f4879029edbcc8010d0b9b64e73676a937f280b2939bb905578a90
+size 33701
diff --git a/marked/T/T-REC-T.105-199411-I_PDF-E/cb4cfa42ce34febde7bdb882f3fc3094_img.jpg b/marked/T/T-REC-T.105-199411-I_PDF-E/cb4cfa42ce34febde7bdb882f3fc3094_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..3c43def3763e86850902a75e0e664d9e187a6731
--- /dev/null
+++ b/marked/T/T-REC-T.105-199411-I_PDF-E/cb4cfa42ce34febde7bdb882f3fc3094_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:8a614427ceaed3e6d21b9ba3e1abe731a357995a2af368f94dd7ed1097f24f32
+size 90513
diff --git a/marked/T/T-REC-T.105-199411-I_PDF-E/cd3e29b6d40dce0580fa43b721157489_img.jpg b/marked/T/T-REC-T.105-199411-I_PDF-E/cd3e29b6d40dce0580fa43b721157489_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..d903f6682f9b5269be4ca89f366111621c600da5
--- /dev/null
+++ b/marked/T/T-REC-T.105-199411-I_PDF-E/cd3e29b6d40dce0580fa43b721157489_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:d7e71d187934bfe7260c6a3818d647dc4dbef60c1d518d0565c16ff0eb73fce7
+size 15892
diff --git a/marked/T/T-REC-T.105-199411-I_PDF-E/d510bddda14c44163bbeee33b491a105_img.jpg b/marked/T/T-REC-T.105-199411-I_PDF-E/d510bddda14c44163bbeee33b491a105_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..48bfedfb99e56f4f3db42a1b42579d507504e4fd
--- /dev/null
+++ b/marked/T/T-REC-T.105-199411-I_PDF-E/d510bddda14c44163bbeee33b491a105_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:1ac2916d023a5c27378c63a1380a503ee55f2b42ddb73ae4d65f535b76c2a3ef
+size 26486
diff --git a/marked/T/T-REC-T.105-199411-I_PDF-E/e93f2f4b0bf7e94139c1a2f1357962da_img.jpg b/marked/T/T-REC-T.105-199411-I_PDF-E/e93f2f4b0bf7e94139c1a2f1357962da_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..631ea285109f0ec8d70a6f73f0b101fb3c143f47
--- /dev/null
+++ b/marked/T/T-REC-T.105-199411-I_PDF-E/e93f2f4b0bf7e94139c1a2f1357962da_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:90009356ccba7ad0517d14c1b40fa2aba4a8feeed709f5804d5e6b78e4ab70bb
+size 10829
diff --git a/marked/T/T-REC-T.105-199411-I_PDF-E/efb282bed9f06eef1987a14fb27bc599_img.jpg b/marked/T/T-REC-T.105-199411-I_PDF-E/efb282bed9f06eef1987a14fb27bc599_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..b5a622f69e4f73ad8b1322ae7a57db87c98b60c6
--- /dev/null
+++ b/marked/T/T-REC-T.105-199411-I_PDF-E/efb282bed9f06eef1987a14fb27bc599_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:7f4de9e1cc9d7babaa12d96896c34f7a685efae5e1837ecfdfcf02804128b24d
+size 10289
diff --git a/marked/T/T-REC-T.10bis-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/T/T-REC-T.10bis-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..4077155593b42133f7d26fc0bd566c876b661161
--- /dev/null
+++ b/marked/T/T-REC-T.10bis-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:e5e43ee6c450c462cecc176fa724b7f7362e006de9c025b0f0155f726f5aa763
+size 7505
diff --git a/marked/T/T-REC-T.10bis-198811-I_PDF-E/raw.md b/marked/T/T-REC-T.10bis-198811-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..309571436301bdde8a984ecb5ebd03ff4af6de60
--- /dev/null
+++ b/marked/T/T-REC-T.10bis-198811-I_PDF-E/raw.md
@@ -0,0 +1,64 @@
+
+
+![ITU logo: a globe with the letters ITU and a lightning bolt symbol.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg)
+
+ITU logo: a globe with the letters ITU and a lightning bolt symbol.
+
+INTERNATIONAL TELECOMMUNICATION UNION
+
+**ITU-T**
+
+TELECOMMUNICATION  
+STANDARDIZATION SECTOR  
+OF ITU
+
+**T.10 *bis***
+
+**TERMINAL EQUIPMENT AND PROTOCOLS FOR  
+TELEMATIC SERVICES**
+
+---
+
+**DOCUMENT FACSIMILE TRANSMISSIONS  
+IN THE GENERAL SWITCHED TELEPHONE  
+NETWORK**
+
+**ITU-T Recommendation T.10 *bis***
+
+(Extract from the *Blue Book*)
+
+---
+
+# NOTES
+
+1 ITU-T Recommendation T.10 *bis* was published in Fascicle VII.3 of the *Blue Book*. This file is an extract from the *Blue Book*. While the presentation and layout of the text might be slightly different from the *Blue Book* version, the contents of the file are identical to the *Blue Book* version and copyright conditions remain unchanged (see below).
+
+2 In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+# **DOCUMENT FACSIMILE TRANSMISSIONS IN THE GENERAL SWITCHED TELEPHONE NETWORK**
+
+*(Mar del Plata, 1968; amended at Geneva, 1972, 1976 and 1980)*
+
+## **1 Type of circuits to be used**
+
+Since circuits of the general telephone network and the station lines of telephone subscribers should be capable of being used for document facsimile transmissions on the general network, the circuits to be used are those of the general switched network which have 2-wire terminals at both ends of the facsimile station.
+
+*Note* – For the actual document transmission, which is one-way, there is no need to cater for the disabling of echo suppressors. Compandors do not seem detrimental to document facsimile transmission.
+
+## **2 Overall loss**
+
+The conditions for overall transmission loss are the same as those for circuits of the general switched telephone network.
+
+## **3 Modulation**
+
+Equipment conforming to Recommendation T.2 or Recommendation T.3 may be used. In the case of Recommendation T.2 equipment, frequency modulation shall be used.
+
+## **4 Power**
+
+In order to avoid the risk that facsimile signals be disturbed, e.g. by dial pulses transmitted over adjacent channels or by noise, it is important that the sending level should be as high as possible, provided, however, that it shall not exceed  $-13$  dBm0 on the trunk circuit for frequency-modulation equipment conforming to Recommendation T.2 or that the mean power in any hour, in one direction of transmission, shall not exceed 32 microwatts ( $-15$  dBm0) at the zero relative level point of the trunk circuit for equipment conforming to Recommendation T.3.
+
+The maximum power output of the transmitting apparatus into the line shall not exceed 1 mW whatever the frequency.
+
+## **5 Amplitude and phase distortion**
+
+Equipment conforming to Recommendation T.2 should not require any special treatment. However, equipment conforming to Recommendation T.3 may require both amplitude and phase distortion correction on certain connections.
\ No newline at end of file
diff --git a/marked/T/T-REC-T.121-199607-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/T/T-REC-T.121-199607-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..a582d89e7241a7467d63836edd82dad0b4e3c021
--- /dev/null
+++ b/marked/T/T-REC-T.121-199607-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:dbe2da7554f1b77fff37eb6076df2a80b768d7f91d1c3e4326ef475ab6a7d114
+size 8349
diff --git a/marked/T/T-REC-T.121-199607-I_PDF-E/3da1a07cb87051bf616c9876db958cf0_img.jpg b/marked/T/T-REC-T.121-199607-I_PDF-E/3da1a07cb87051bf616c9876db958cf0_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..420f47e20a5fb468df49ef14639688343ce97082
--- /dev/null
+++ b/marked/T/T-REC-T.121-199607-I_PDF-E/3da1a07cb87051bf616c9876db958cf0_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:99d675c7b8e40a9bd760f3652ddb4497a56c76e53f259b06ed39b97090397c9d
+size 55783
diff --git a/marked/T/T-REC-T.121-199607-I_PDF-E/67114ecf6da13c97a89aeff0d86885d5_img.jpg b/marked/T/T-REC-T.121-199607-I_PDF-E/67114ecf6da13c97a89aeff0d86885d5_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..12e0e5bd93c5a76c7c5dd227a9ede1ea7358a117
--- /dev/null
+++ b/marked/T/T-REC-T.121-199607-I_PDF-E/67114ecf6da13c97a89aeff0d86885d5_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:727ffbe85d920505ae4c022e90149b95f5972b003884acd769e48b0f0ee7aa58
+size 46783
diff --git a/marked/T/T-REC-T.121-199607-I_PDF-E/69b7bd65e85cdef6fdd7fb0a8194257c_img.jpg b/marked/T/T-REC-T.121-199607-I_PDF-E/69b7bd65e85cdef6fdd7fb0a8194257c_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..a3b7c6e33707c8bacfce97ba060183fbef6df8f7
--- /dev/null
+++ b/marked/T/T-REC-T.121-199607-I_PDF-E/69b7bd65e85cdef6fdd7fb0a8194257c_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:6628d021a19bbf04b3aad0053c00d6ff98ac92731083a731cd24ed8406af8507
+size 211522
diff --git a/marked/T/T-REC-T.121-199607-I_PDF-E/8c348bf9c2c81b018017ae1d19506a9a_img.jpg b/marked/T/T-REC-T.121-199607-I_PDF-E/8c348bf9c2c81b018017ae1d19506a9a_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..747d83c197a1d8cb870551ed3dd7b48c9edcf01b
--- /dev/null
+++ b/marked/T/T-REC-T.121-199607-I_PDF-E/8c348bf9c2c81b018017ae1d19506a9a_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:9b38f41f04f11dbb3f1a4014dccb2ca3db4361c445cf287b61b42101efcabad0
+size 202782
diff --git a/marked/T/T-REC-T.121-199607-I_PDF-E/a5ee5c23b6dc52ec1d724b76d5a5f58f_img.jpg b/marked/T/T-REC-T.121-199607-I_PDF-E/a5ee5c23b6dc52ec1d724b76d5a5f58f_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..78a33509e8024646e3af35fe5f4a278786029d09
--- /dev/null
+++ b/marked/T/T-REC-T.121-199607-I_PDF-E/a5ee5c23b6dc52ec1d724b76d5a5f58f_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:755c09e0d13122123be61f9b69cef47160cca5df70511a8d2f442a3d6c3edd04
+size 131246
diff --git a/marked/T/T-REC-T.121-199607-I_PDF-E/a83ba9e3e2c1e21dd69953a7b09e45b4_img.jpg b/marked/T/T-REC-T.121-199607-I_PDF-E/a83ba9e3e2c1e21dd69953a7b09e45b4_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..c09561febd9250f8520798f5e5da5f1e73d01cb2
--- /dev/null
+++ b/marked/T/T-REC-T.121-199607-I_PDF-E/a83ba9e3e2c1e21dd69953a7b09e45b4_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:ee050947bce6cce323ce12ad847ecc72f97517979a6cdfd3a1a7872d731e9483
+size 70232
diff --git a/marked/T/T-REC-T.121-199607-I_PDF-E/acfc53eca625d62b38aa2563efa95c3e_img.jpg b/marked/T/T-REC-T.121-199607-I_PDF-E/acfc53eca625d62b38aa2563efa95c3e_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..8859e524338871038eec449eafb6d769041508fd
--- /dev/null
+++ b/marked/T/T-REC-T.121-199607-I_PDF-E/acfc53eca625d62b38aa2563efa95c3e_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:fcaecd48de8ba253421d4279e90c31abf4a83a380c51a67b0a3cfcc6e86f6b1f
+size 125254
diff --git a/marked/T/T-REC-T.121-199607-I_PDF-E/c494cd874a082a97b50b3c4d3938f467_img.jpg b/marked/T/T-REC-T.121-199607-I_PDF-E/c494cd874a082a97b50b3c4d3938f467_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..e496f933c770c57cc6366d373dce10b549eea1bb
--- /dev/null
+++ b/marked/T/T-REC-T.121-199607-I_PDF-E/c494cd874a082a97b50b3c4d3938f467_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:c25ae2adf31925890678216fa5adb7a465d5626267f80ba172c7c51070cf86c5
+size 273027
diff --git a/marked/T/T-REC-T.121-199607-I_PDF-E/c914f51f4427bc672dd0526cfc90ebe9_img.jpg b/marked/T/T-REC-T.121-199607-I_PDF-E/c914f51f4427bc672dd0526cfc90ebe9_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..05a3cda0074e78ee47ab89c5acb8194471e77d78
--- /dev/null
+++ b/marked/T/T-REC-T.121-199607-I_PDF-E/c914f51f4427bc672dd0526cfc90ebe9_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:45c5cc1280e43d13767342d9f5117e7d1700213c1e5a2af8c824d7db3bf9bc1b
+size 256429
diff --git a/marked/T/T-REC-T.121-199607-I_PDF-E/cbdfdade780e677eb1c1aef3081ce9ef_img.jpg b/marked/T/T-REC-T.121-199607-I_PDF-E/cbdfdade780e677eb1c1aef3081ce9ef_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..1ce2df4923eb4c26a1b26303d3505d357a290656
--- /dev/null
+++ b/marked/T/T-REC-T.121-199607-I_PDF-E/cbdfdade780e677eb1c1aef3081ce9ef_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:6458419d3e2a608e3f866bb21e39081136bfc037b9011a8e72fdf1c28c75f940
+size 282736
diff --git a/marked/T/T-REC-T.121-199607-I_PDF-E/cfb98c691c1af5befe32ff9442eea511_img.jpg b/marked/T/T-REC-T.121-199607-I_PDF-E/cfb98c691c1af5befe32ff9442eea511_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..7f74c707c681ac07d9cc19b28751fd911a1604ef
--- /dev/null
+++ b/marked/T/T-REC-T.121-199607-I_PDF-E/cfb98c691c1af5befe32ff9442eea511_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:af653ea7f5d023380a7f6e396b06e7b8f2a2639eb95342bc323b380a1dfdfbca
+size 51865
diff --git a/marked/T/T-REC-T.121-199607-I_PDF-E/cfef993dcc8fb513de79eb1f93cf26ae_img.jpg b/marked/T/T-REC-T.121-199607-I_PDF-E/cfef993dcc8fb513de79eb1f93cf26ae_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..a9107f819adc1e9b0bf12c62c800ae57106effed
--- /dev/null
+++ b/marked/T/T-REC-T.121-199607-I_PDF-E/cfef993dcc8fb513de79eb1f93cf26ae_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:781cf6ec24e4ca8729cfb9ad3d18c32f8866b9565da396b5aee94ee9cd4c62ef
+size 103490
diff --git a/marked/T/T-REC-T.121-199607-I_PDF-E/d4af765160d04ecef538e5066006dc77_img.jpg b/marked/T/T-REC-T.121-199607-I_PDF-E/d4af765160d04ecef538e5066006dc77_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..493382957a6ca6670edad3130e194a5ab1fa6422
--- /dev/null
+++ b/marked/T/T-REC-T.121-199607-I_PDF-E/d4af765160d04ecef538e5066006dc77_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:84e03a884a965d5ddff352fc46717ab4ff4a7f6fe171366a07f9309462c4f959
+size 120281
diff --git a/marked/T/T-REC-T.121-199607-I_PDF-E/d53cd0fd1cf896a9353fd63de1505ba2_img.jpg b/marked/T/T-REC-T.121-199607-I_PDF-E/d53cd0fd1cf896a9353fd63de1505ba2_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..0dd0d3713e1569d391ca80865d1e96ee0160ffbf
--- /dev/null
+++ b/marked/T/T-REC-T.121-199607-I_PDF-E/d53cd0fd1cf896a9353fd63de1505ba2_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:9c240cb497a4bb8ef961c77967be105348effc713a332e854fc82a553be3dda6
+size 107234
diff --git a/marked/T/T-REC-T.121-199607-I_PDF-E/f57c7b37d7a05a99618104f390089f03_img.jpg b/marked/T/T-REC-T.121-199607-I_PDF-E/f57c7b37d7a05a99618104f390089f03_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..41057a3aad0f917ae94866acc7a79fc274c2385c
--- /dev/null
+++ b/marked/T/T-REC-T.121-199607-I_PDF-E/f57c7b37d7a05a99618104f390089f03_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:8c1b8b091cbe8cffa97fe2658d213ce989cd3899249d2d3e059a05bed96d593a
+size 169103
diff --git a/marked/T/T-REC-T.121-199607-I_PDF-E/f9c64800d9bace9b4315646d1057be3c_img.jpg b/marked/T/T-REC-T.121-199607-I_PDF-E/f9c64800d9bace9b4315646d1057be3c_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..04461f69ae070d7dd3535ddfe9fd9d2e7898a724
--- /dev/null
+++ b/marked/T/T-REC-T.121-199607-I_PDF-E/f9c64800d9bace9b4315646d1057be3c_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:10ce038de07b2577ae99ba3114952c28cb6d48c6f2f773eb7d95e04aec3781dd
+size 134087
diff --git a/marked/T/T-REC-T.121-199607-I_PDF-E/raw.md b/marked/T/T-REC-T.121-199607-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..f3425a922bdd6eeb1e97328c6a42a65aa6bfc456
--- /dev/null
+++ b/marked/T/T-REC-T.121-199607-I_PDF-E/raw.md
@@ -0,0 +1,1539 @@
+
+
+![ITU logo: a globe with the letters ITU inside, and a lightning bolt striking the globe.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg)
+
+ITU logo: a globe with the letters ITU inside, and a lightning bolt striking the globe.
+
+INTERNATIONAL TELECOMMUNICATION UNION
+
+# ITU-T
+
+TELECOMMUNICATION  
+STANDARDIZATION SECTOR  
+OF ITU
+
+# T.121
+
+(07/96)
+
+SERIES T: TERMINAL EQUIPMENTS AND PROTOCOLS  
+FOR TELEMATIC SERVICES
+
+---
+
+# **Generic application template**
+
+ITU-T Recommendation T.121
+
+(Previously "CCITT Recommendation")
+
+---
+
+# **ITU-T T-SERIES RECOMMENDATIONS** **TERMINAL EQUIPMENTS AND PROTOCOLS FOR TELEMATIC SERVICES**
+
+*For further details, please refer to ITU-T List of Recommendations.*
+
+# FOREWORD
+
+The ITU-T (Telecommunication Standardization Sector) is a permanent organ of the International Telecommunication Union (ITU). The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis.
+
+The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics.
+
+The approval of Recommendations by the Members of the ITU-T is covered by the procedure laid down in WTSC Resolution No. 1 (Helsinki, March 1-12, 1993).
+
+ITU-T Recommendation T.121 was prepared by ITU-T Study Group 8 (1993-1996) and was approved under the WTSC Resolution No. 1 procedure on the 3rd of July 1996.
+
+# --- NOTE
+
+In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+© ITU 1996
+
+All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU.
+
+
+
+# CONTENTS
+
+|                                                                      | <i>Page</i> |
+|----------------------------------------------------------------------|-------------|
+| 1 Scope .....                                                        | 1           |
+| 2 Normative References .....                                         | 1           |
+| 3 Definitions .....                                                  | 2           |
+| 4 Abbreviations .....                                                | 2           |
+| 5 Overview .....                                                     | 2           |
+| 5.1 User application .....                                           | 7           |
+| 5.2 Application Protocol Entity .....                                | 8           |
+| 5.3 Application Resource Manager .....                               | 8           |
+| 5.4 Application Service Element .....                                | 9           |
+| 6 Generic Application Template .....                                 | 10          |
+| 6.1 Initialization .....                                             | 11          |
+| 6.2 Enrollment .....                                                 | 11          |
+| 6.2.1 Registration session .....                                     | 14          |
+| 6.2.2 Standard base session .....                                    | 15          |
+| 6.2.3 Non-standard base session .....                                | 15          |
+| 6.2.4 Public session .....                                           | 21          |
+| 6.2.5 Private session .....                                          | 24          |
+| 6.3 Forming registry keys .....                                      | 26          |
+| 6.4 Capability negotiation .....                                     | 26          |
+| 6.5 Leaving a session .....                                          | 26          |
+| 7 Review of MCS resources and GCC services .....                     | 27          |
+| 7.1 Channels .....                                                   | 27          |
+| 7.1.1 Static channel .....                                           | 27          |
+| 7.1.2 Dynamic channel .....                                          | 27          |
+| 7.1.3 User ID channel .....                                          | 28          |
+| 7.1.4 Assigned Channel .....                                         | 28          |
+| 7.1.5 Private channel .....                                          | 30          |
+| 7.1.6 Potential problems with the use of MCS channels .....          | 30          |
+| 7.1.7 Summary .....                                                  | 31          |
+| 7.2 Data transfer .....                                              | 32          |
+| 7.3 Tokens .....                                                     | 32          |
+| 7.3.1 Static tokens .....                                            | 33          |
+| 7.3.2 Dynamic tokens .....                                           | 33          |
+| 7.4 Application roster .....                                         | 34          |
+| 7.5 Application Registry .....                                       | 35          |
+| 7.6 Conductorship .....                                              | 35          |
+| 7.7 Remote invoking .....                                            | 36          |
+| 8 User application guidelines .....                                  | 36          |
+| 8.1 Identification of user applications .....                        | 36          |
+| 8.2 Use of collapsing and non-collapsing capabilities .....          | 36          |
+| 8.3 Session context .....                                            | 37          |
+| 8.4 Selecting a session to participate in .....                      | 37          |
+| 8.5 Controlling the use of a session .....                           | 37          |
+| 8.6 Adding new participants to a session .....                       | 37          |
+| 8.7 Extension, modification and reuse of application protocols ..... | 38          |
+
+# **SUMMARY**
+
+This Recommendation provides guidance for application developers and application protocol developers on the correct and effective use of the T.120 infrastructure. It provides a generic model for an application that communicates using T.120 services and defines a Generic Application Template specifying the use of T.122 (MCS) and T.124 (GCC) services that are commonly required by application protocols making use of T.120 services. This Recommendation provides a common structure to application protocol entities, ensuring that separate application protocol entities can coexist in the same conference. Application protocol entities that do not follow the operations defined in this Recommendation risk interfering with other application protocols.
+
+# GENERIC APPLICATION TEMPLATE
+
+(Geneva, 1996)
+
+# 1 Scope
+
+Whilst user applications themselves are not the subject of standardization, the protocols employed by a user application need to be standardized in order to guarantee interworking. This Recommendation provides a generic model for a T.120 application with a view to defining a common framework (the Generic Application Template) to form the basis of standardized application protocols. It also provides guidance to user application developers on how to exploit the T.120 infrastructure to achieve the desired application behaviour. The templates defined in this Recommendation are derived from terminal based application protocols; application protocols which incorporate an MCU component may require different provisions.
+
+A T.120 user application employs one or more Application Protocol Entities to communicate with user applications of similar functionality at other nodes in a conference. It is important to observe that, whilst it is not necessary to have identical implementations at each node in order to achieve interoperability, groups of communicating user applications must employ the same application protocols for the same general purpose. Differences in capabilities are resolved through a capability exchange mechanism.
+
+Each Application Protocol Entity (APE) consists of two components:
+
+- A generic portion which includes elements common to most or all application protocols, for example initialization and resource management. Such operations need only be specified once (in this Recommendation) and then referenced by each protocol specification.
+- A function specific portion which enables user applications of like functionality to interwork. This part may be standardized in which case it is specified in a T.120 application protocol Recommendation, or non-standard.
+
+This Recommendation describes the components identified above and defines a Generic Application Template (GAT) containing those operations that are expected to be common to most T.120 application protocols. The Generic Application Template eases the task of the application protocol developer and provides a common structure for application protocol entities. This modular approach allows the function specific elements of a protocol specification to be clearly identified, and thus enables it to be reused more readily in other protocol specifications. This Recommendation defines a rigorous protocol which is expressed through a sequence of primitive operations. Furthermore, this Recommendation can be made normative by reference from standardized application protocol Recommendations. Use of the Generic Application Template in the definition of T.120 application protocols is encouraged.
+
+# 2 Normative References
+
+The following Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision: all users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published.
+
+- ITU-T Recommendation T.120 (1996), *Data protocols for multimedia conferencing*.
+- ITU-T Recommendation T.122 (1993), *Multipoint communication service for audiographics and audio-visual conferencing service definition*.
+- ITU-T Recommendation T.124 (1995), *Generic conference control*.
+- ITU-T Recommendation T.125 (1994), *Multipoint communication service protocol specification*.
+- ITU-T Recommendation T.50 (1992), *International Reference Alphabet (IRA) (Formerly International Alphabet No. 5 or IA5) – Information Technology – 7-bit coded character set for information interchange*.
+
+# 3 Definitions
+
+For the purposes of this Recommendation, the following definitions apply:
+
+- 3.1 application resource manager:** The part of an Application Protocol Entity that provides generic functionality for managing GCC and MCS resources.
+- 3.2 application service element:** The part of an Application Protocol Entity that provides Application Protocol specific functionality, e.g. message formats and sequences.
+- 3.3 non-standard base session:** An Application Protocol Session that can be located by non-standard APEs without requiring user intervention. As such it is similar to a standard base session used by standard APEs.
+- 3.4 private session:** An Application Protocol Session with restricted membership controlled by the creator of that session.
+- 3.5 public session:** An Application Protocol Session with unrestricted membership that is typically used if the relevant base session for the protocol is already in use and a user wishes to establish further independent sessions.
+- 3.6 registration session:** An Application Protocol Session used by applications to advertise their presence to the conference. A Registration Session makes use of the T.124 default session in which there is no Session ID.
+- 3.7 session creator:** The Application Protocol Entity that enrolls in a new Application Protocol Session. The concept of a session creator only applies to public and private sessions.
+- 3.8 session member:** An Application Protocol Entity that enrolls in an existing Application Protocol Session. The concept of a session member only applies to public and private sessions.
+- 3.9 standard base session:** An Application Protocol Session that can be located by standard APEs without requiring user intervention. Standard base session identifiers are specified in Recommendation T.120.
+
+# 4 Abbreviations
+
+For the purposes of this Recommendation, the following abbreviations are used:
+
+|         |                                  |
+|---------|----------------------------------|
+| ARM     | Application Resource Manager     |
+| APE     | Application Protocol Entity      |
+| ASE     | Application Service Element      |
+| GAT     | Generic Application Template     |
+| GCC     | Generic Conference Control       |
+| GCC SAP | GCC Service Access Point         |
+| MCS     | Multipoint Communication Service |
+| MCSAP   | MCS Service Access Point         |
+| MCU     | Multipoint Control Unit          |
+| PDU     | Protocol Data Unit               |
+| SAP     | Service Access Point             |
+
+# 5 Overview
+
+Figure 1 illustrates the T.120 system model in which user applications employ both standard and non-standard application protocols in order to communicate with their peers at other nodes within the same conference. The scope of a user application is restricted to local functions (e.g. user interface) that do not affect communication between peer user applications. Each user application makes use of one or more Application Protocol Entities (APEs) that implement interworking protocols as shown in Figure 2. In the model described here, an APE can be further subdivided into two
+
+elements: an Application Resource Manager (ARM) and an Application Service Element (ASE). The ARM is responsible for the generic management of GCC and MCS resources whilst the ASE provides interworking of specific functionality; for example, an ASE may provide general purpose file transfer functionality as specified in Recommendation T.127, or still image exchange functionality as specified in Recommendation T.126.
+
+![T.120 system model diagram showing the hierarchy from User Applications to Network Specific Transport Protocols.](acfc53eca625d62b38aa2563efa95c3e_img.jpg)
+
+The diagram illustrates the T.120 system model architecture, organized into several layers and components:
+
+- User Application(s) (Using both standard and non-standard Application Protocols)**: The top-level layer.
+- User Application(s) (Using std. Appl. Protocols)**: A sub-layer for standard protocols.
+- Node Controller**: A central control component.
+- User Application(s) (Using non-std Protocols)**: A sub-layer for non-standard protocols.
+- T.120 Application Protocol Recommendations**: A shaded box containing:
+  - T.126 Still Image (SI)**
+  - T.127 File Transfer (MBFT)**
+  - ...**
+- Non-standard Application Protocol Entities**: A stack of entities for non-standard protocols.
+- Generic Conference Control (GCC) Rec. T.124**: A central control component within the infrastructure.
+- Multipoint Communication Service (MCS) Rec. T.122/125**: A service layer within the infrastructure.
+- Network Specific Transport Protocols Rec. T.123**: The bottom layer of the infrastructure.
+- T.120 Infrastructure Recommendations**: A shaded box encompassing the GCC, MCS, and Network Specific Transport Protocols layers.
+
+Arrows indicate bidirectional communication between the User Applications and the Node Controller, and between the various protocol layers and the GCC component.
+
+T.120 system model diagram showing the hierarchy from User Applications to Network Specific Transport Protocols.
+
+T0825000-95/d01
+
+FIGURE 1/T.121  
+T.120 system model
+
+![Model of Generic T.120 Application Protocol Entity diagram showing the hierarchy from User Application down to Multipoint Communication Service (MCS).](a5ee5c23b6dc52ec1d724b76d5a5f58f_img.jpg)
+
+The diagram illustrates the Model of Generic T.120 Application Protocol Entity. It shows a hierarchical structure of components and their interactions:
+
+- User Application**: The top-level component, represented by a white rectangle.
+- Application Protocol Entity (APE)**: A large gray rectangle containing nested components:
+  - Application Resource Manager (ARM)**: A white rectangle nested within the APE.
+  - Application Service Element (ASE)**: A gray rectangle nested within the ARM.
+- Node Controller**: A white rectangle to the left of the APE, connected to the ARM by a double-headed arrow.
+- Generic Conference Control (GCC) Rec. T.124**: A white rounded rectangle below the APE, connected to the APE and the Node Controller by double-headed arrows.
+- Multipoint Communication Service (MCS) Rec. T.122/T.125**: A white rounded rectangle at the bottom, connected to the GCC and the APE by double-headed arrows.
+
+Interactions are shown with solid double-headed arrows for direct connections and dotted lines for indirect or multiple connections. Dotted lines show a path from the User Application through the APE to the Node Controller, and another path from the User Application through the APE to the GCC and MCS.
+
+Model of Generic T.120 Application Protocol Entity diagram showing the hierarchy from User Application down to Multipoint Communication Service (MCS).
+
+T0825010-95/d02
+
+FIGURE 2/T.121  
+Model of Generic T.120 Application Protocol Entity
+
+Peer Application Protocol Elements communicating with each other are said to be participating in the same application protocol *session*. Note that more than one user application at a given site may participate in the same session. This entails multiple instances of the application protocol, i.e. multiple APEs, one per user application. It is also possible to have multiple concurrent sessions using the same application protocol. Again, each participating user application requires its own APE. An example scenario is illustrated in Figure 3.
+
+![Diagram illustrating multiple applications at a site using the same protocol. It shows three sites (A, B, and C) connected to a central network. Site A has User Applications 1 and 2, Site B has User Applications 3 and 4, and Site C has User Applications 3 and 1. Each user application is connected to a T.126 APE. These APEs are grouped into two sessions: Multipoint Still Image and Annotation Protocol Session A (containing APEs for User Applications 1, 2, 3, and 4) and Multipoint Still Image and Annotation Protocol Session B (containing APEs for User Applications 1 and 2).](cfef993dcc8fb513de79eb1f93cf26ae_img.jpg)
+
+The diagram illustrates a network topology where multiple user applications at different sites participate in the same protocol sessions. At the top, Site B contains User Application 3 and User Application 4. Below it, Site A contains User Application 1 and User Application 2. To the right, Site C contains User Application 3 and User Application 1. Each user application is connected to a T.126 APE (Application Protocol Entity). These APEs are organized into two sessions: 'Multipoint Still Image and Annotation Protocol Session A' and 'Multipoint Still Image and Annotation Protocol Session B'. Session A includes APEs for User Applications 1, 2, 3, and 4. Session B includes APEs for User Applications 1 and 2. The sessions are represented by shaded ovals, and the connections between applications and APEs are shown with arrows.
+
+Diagram illustrating multiple applications at a site using the same protocol. It shows three sites (A, B, and C) connected to a central network. Site A has User Applications 1 and 2, Site B has User Applications 3 and 4, and Site C has User Applications 3 and 1. Each user application is connected to a T.126 APE. These APEs are grouped into two sessions: Multipoint Still Image and Annotation Protocol Session A (containing APEs for User Applications 1, 2, 3, and 4) and Multipoint Still Image and Annotation Protocol Session B (containing APEs for User Applications 1 and 2).
+
+T0825340-96/d03
+
+FIGURE 3/T.121  
+Example of multiple applications at a site using the same protocol
+
+A session comprises a group of peer Application Protocol Entities that employ a common application protocol to communicate with each other. Each Session has a Session Identifier whose value is equal to that of an MCS Channel ID, typically one that is used to transfer data within the group of APEs. In the models presented here, the channel associated with the Session Identifier is the first channel joined, although this is not required to be the case. It is known as the *Session Identifier Channel*. A user application that employs multiple APEs may participate in multiple application protocol sessions. Each session could have a unique Session Identifier, but this is not required. Different types of application protocol entity participate in different sessions, even if they have the same Session ID. An example scenario is illustrated in Figure 4. For each application protocol, it is possible to have a single application protocol session without a Session Identifier; this is referred to as the *registration session*.
+
+The following session types exist:
+
+**Registration Session:** may be used by both standard and non-standard application protocols. The purpose of a registration session is to enable applications to advertise their presence to the conference, without having to become active. This enables applications to determine which nodes in the conference have similar functionality, whilst at the same time consuming minimal resources. The registration session also allows applications to advertise application protocol specific functionality to the conference as non-collapsing capabilities. Applications would typically remain enrolled in the registration session for the duration of the conference in order to receive notification of any changes in functionality advertised by other nodes. An application enrolled in the registration session for a specific application protocol receives information on all sessions in the conference using that particular application protocol.
+
+![Diagram illustrating applications using multiple protocols across three sites (A, B, and C). Site A has User Application 1, which connects to T.127 APE, NonStd APE, and T.126 APE. Site B has User Application 2 and User Application 3, both connecting to T.127 APE. Site C has User Application 1, which connects to T.127 APE and T.126 APE. The T.127 APEs are part of a Multipoint Binary File Transfer Session. The NonStd APEs are part of a Proprietary Application Protocol Session. The T.126 APEs are part of a Multipoint Still Image and Annotation Protocol Session.](d4af765160d04ecef538e5066006dc77_img.jpg)
+
+The diagram shows three sites (A, B, and C) connected to three different sessions. Site A has a computer icon and 'User Application 1'. Site B has two computer icons and 'User Application 2' and 'User Application 3'. Site C has a computer icon and 'User Application 1'. Arrows indicate connections from user applications to specific APEs (Application Protocol Elements) within sessions. Site A's User Application 1 connects to T.127 APE, NonStd APE, and T.126 APE. Site B's User Application 2 and User Application 3 both connect to T.127 APE. Site C's User Application 1 connects to T.127 APE and T.126 APE. The T.127 APEs are grouped in a 'Multipoint Binary File Transfer Session'. The NonStd APEs are grouped in a 'Proprietary Application Protocol Session'. The T.126 APEs are grouped in a 'Multipoint Still Image and Annotation Protocol Session'.
+
+Diagram illustrating applications using multiple protocols across three sites (A, B, and C). Site A has User Application 1, which connects to T.127 APE, NonStd APE, and T.126 APE. Site B has User Application 2 and User Application 3, both connecting to T.127 APE. Site C has User Application 1, which connects to T.127 APE and T.126 APE. The T.127 APEs are part of a Multipoint Binary File Transfer Session. The NonStd APEs are part of a Proprietary Application Protocol Session. The T.126 APEs are part of a Multipoint Still Image and Annotation Protocol Session.
+
+T0825350-96/d04
+
+FIGURE 4/T.121  
+Example of applications using multiple protocols
+
+Use of a registration session for actual application activity is not part of these models and is discouraged. This ensures a clean segregation of active and dormant applications. This segregation is important because:
+
+- Any collapsing capabilities advertised by inactive applications may have an adverse impact on the capability set of the session.
+- Defunct registry entries in a registration session resulting from application activity are likely to persist until the end of the conference.
+
+For each application protocol within a conference there can be at most one registration session. It is characterized by having a Session Key comprised of the appropriate Application Protocol Key and no Session ID.
+
+**Standard Base Session:** reserved for use by standardized application protocols. Access to a standard base session is unrestricted and all participants within the session have equal status, that of session member; they may join and leave the session at will. As the Session Identifier for a standard base session of a standardized application protocol is predefined (in Recommendation T.120), an application may join the session without any user intervention. A standard base session uses a static channel as the Session ID channel. The set of resources that need to be identified during the enrollment process for a standard base session may include further static or dynamic channels and tokens, as specified by the application protocol. Dynamic channels and tokens may be employed if additional resources are required beyond this basic set.
+
+Typically, the standard base session would be the preferred choice for an application using a standard application protocol that wishes to communicate with all peer applications within a conference. For each standardized application protocol within a conference, there is at most one standard base session.
+
+**Non-Standard Base Session:** reserved for use by non-standard application protocols. The non-standard base session allows applications which employ a common non-standard protocol to independently locate the same session, without requiring user intervention to select a specific session. Typically, the non-standard base session would be the preferred choice for an application using a non-standard application protocol that wishes to communicate with all peer applications within a conference. The non-standard base session uses an assigned (i.e. dynamic multicast) channel as Session ID, the identity of which is discovered using the GCC Application Registry. A consequence of participating in the non-standard base session is that the corresponding registration session is joined. For each non-standard application protocol within a conference there can be not more than one non-standard base session. Once all participants have left a non-standard base session it ceases to exist and must be recreated if required subsequently.
+
+**Public Session:** may be used by either standard or non-standard application protocols. A public session is typically used if the relevant base session for the protocol is already in use and a user wishes to establish further independent sessions to communicate with all peer applications within a conference. Access to a public session is uncontrolled. A public session has a designated creator. This is the APE which assigns the multicast Session Identifier channel and is responsible for registering the resources for the session; all other participants are members of the session. Any participant may join and leave a public session at will; they may optionally choose to invite other nodes to participate in the session using the GCC-Application-Invoke mechanism. A public session may persist after the creator of the session has left it or even detached. Once all participants have left a public session, no one can rejoin as the session ceases to exist.
+
+**Private Session:** may be used by either standard or non-standard application protocols. A private session is typically employed when a user wishes to restrict membership of an application protocol session to a selected subset of conference participants. A private session has a designated creator. This is the APE which convenes the private session and is responsible for registering the resources for the session. Participation in the private session is controlled by the session creator who must explicitly invite other applications to become members of the session. A private session ceases to exist after the creator of the session has disbanded it or detached.
+
+## 5.1 User application
+
+A user application addresses those tasks which have no direct effect on interworking (e.g. user interface) and which may thus be product and platform specific. The influence of the user application is felt at other sites through the application protocols it employs.
+
+A user application relies on the services of one or more Application Protocol Entities (APEs) to communicate with peer user applications at other nodes. It does not communicate with MCS or GCC; this is done by the APE(s). The interface between a user application and its APE(s) is a local matter and is outside the scope of this Recommendation.
+
+For each APE the user application employs, the user application defines the subset of that APE's capabilities to be advertised. It also selects the type of session (standard base, non-standard base, public, private or registration) when creating a new instance of that APE.
+
+The user application communicates with the appropriate APE to initiate an application session specifying the application capabilities and mode of operation for the session. Once a session has been established, all application protocol specific transactions are performed by the APE on behalf of the user application.
+
+## 5.2 Application Protocol Entity
+
+An Application Protocol Entity (APE) is employed by a user application to enable it to communicate with other user applications of like functionality, i.e. user applications which employ the same application protocol for the same purpose. For example, user applications which require general purpose file transfer functionality must employ an application protocol entity which uses the protocol defined in Recommendation T.127 and the application protocol key specified in Recommendation T.127 to guarantee interoperability. APEs may use either standard or non-standard application protocols.
+
+An APE has two conceptual components as shown in Figure 2: an Application Resource Manager (ARM) and an Application Service Element (ASE). The ARM provides generic functionality, common to many standardized application protocols, whilst the ASE provides functionality specific to its respective application protocol.
+
+In the general model, an Application Protocol Entity is characterized by the following attributes:
+
+- A single Application Resource Manager (ARM).
+- A single Application Service Element (ASE).
+- A single GCC SAP.
+- Interaction with a Node Controller (outside the scope of T.120 Recommendations).
+- One or more MCSAPs.
+- A single enrolled MCS User ID.
+- A capability list (including collapsing and non-collapsing capabilities).
+- A single Session ID. (Peer APEs communicating with each other share the same Session ID. The absence of a Session ID indicates that the APE is enrolled in the registration session for the application protocol.)
+- An Application Protocol Key.
+
+## 5.3 Application Resource Manager
+
+The Application Resource Manager (ARM) is responsible for managing GCC and MCS resources on behalf of the ASE within its APE. The ARM provides the following services:
+
+- Responding to indications from GCC (e.g. permission to enroll).
+- Enrolling its APE with GCC.
+- Obtaining handles from GCC.
+- Attaching to an MCS domain to obtain a unique MCS User ID for its APE.
+- Joining static channels.
+- Identifying and joining assigned channels using the GCC Registry and MCS.
+- Convening private channels and admitting peer APEs to such channels.
+- Joining any private channels to which its APE has been admitted.
+- Identifying and obtaining tokens from the GCC Registry.
+- Identifying and assigning parameters using the GCC Registry.
+- Deleting any redundant Registry entries for which the APE is responsible.
+- Invoking peer APEs at other nodes.
+- Processing Application Roster reports to determine the current negotiated Application Capability list and identity of peer nodes.
+- Receiving GCC-Conductor-Assign and Release indications.
+- Notifying its ASE of changes in conductorship status.
+
+## 5.4 Application Service Element
+
+The Application Service Element (ASE) provides application protocol specific functionality to the user application with resources obtained by the ARM. For example, in Recommendation T.127 the ASE provides general purpose file transfer functionality. Its operation is independent of the type (i.e. static or dynamic) and identity of tokens and channels passed to it. The ASE obtains the identity of resources to use from its ARM. In the case of transactions on private channels, the user application must specify the GCC Node IDs of those nodes with which communication is required.
+
+The ASE provides the following services:
+
+- Sending and receiving application protocol specific PDUs.
+- Grabbing and releasing tokens and determining token status using MCS.
+- Joining and leaving channels via the ARM.
+
+Table 1 defines the partitioning of primitives used by an APE between its ARM and ASE components. GCC primitives not referenced in this table are processed by the Node Controller.
+
+TABLE 1/T.121  
+Primitives used by ARM/ASE
+
+| Primitive                            | ARM        | ASE | Node Controller |
+|--------------------------------------|------------|-----|-----------------|
+| GCC-Registry-Register-Channel        | ✓          |     |                 |
+| GCC-Registry-Assign-Token            | ✓          |     |                 |
+| GCC-Registry-Set-Parameter           | ✓          |     |                 |
+| GCC-Registry-Retrieve-Entry          | ✓          |     |                 |
+| GCC-Registry-Delete-Entry            | ✓          |     |                 |
+| GCC-Registry-Monitor                 | ✓          |     |                 |
+| GCC-Registry-Allocate-Handle         | ✓          |     |                 |
+| GCC-Conference-Roster-Inquire        | ✓          |     | ✓               |
+| GCC-Conductor-Assign                 | Indication |     | ✓               |
+| GCC-Conductor-Release                | Indication |     | ✓               |
+| GCC-Conductor-Please                 |            |     | ✓               |
+| GCC-Conductor-Give                   |            |     | ✓               |
+| GCC-Conductor-Inquire                | ✓          |     | ✓               |
+| GCC-Conductor-Permission-Ask         | Indication |     | ✓               |
+| GCC-Conductor-Permission-Grant       | Indication |     | ✓               |
+| GCC-Application-Permission-To-Enroll | ✓          |     |                 |
+| GCC-Application-Enroll               | ✓          |     |                 |
+| GCC-Application-Roster-Report        | ✓          |     | ✓               |
+| GCC-Application-Roster-Inquire       | ✓          |     | ✓               |
+| GCC-Application-Invoke               | Request    |     | ✓               |
+| MCS-Attach-User                      | ✓          |     |                 |
+| MCS-Detach-User                      | ✓          |     |                 |
+| MCS-Channel-Join                     | ✓          |     |                 |
+| MCS-Channel-Leave                    | ✓          |     |                 |
+| MCS-Channel-Convene                  | ✓          |     |                 |
+| MCS-Channel-Disband                  | ✓          |     |                 |
+| MCS-Channel-Admit                    | ✓          |     |                 |
+| MCS-Channel-Expel                    | ✓          |     |                 |
+| MCS-Send-Data                        |            | ✓   |                 |
+| MCS-Uniform-Send-Data                |            | ✓   |                 |
+| MCS-Token-Grab                       |            | ✓   |                 |
+| MCS-Token-Inhibit                    |            | ✓   |                 |
+
+TABLE 1/T.121 (concluded)
+
+### **Primitives used by ARM/ASE**
+
+| Primitive         | ARM | ASE | Node Controller |
+|-------------------|-----|-----|-----------------|
+| MCS-Token-Give    |     | ✓   |                 |
+| MCS-Token-Please  |     | ✓   |                 |
+| MCS-Token-Release |     | ✓   |                 |
+| MCS-Token-Test    |     | ✓   |                 |
+
+# 6 Generic Application Template
+
+The Generic Application Template (GAT) is designed to provide generic resource management functionality to both standard and non-standard application protocols. As such, it has an Application Resource Manager (the Generic ARM), but does not have an Application Service Element (ASE) – see Figure 5. Separate application protocol specifications detail the operation of their respective ASEs and identify which services offered by the Generic ARM are required by the ASEs. They do not need to describe the operation of the ARM, but should instead reference this Recommendation. The Generic ARM provides all the services described in 5.3.
+
+![Figure 5/T.121: Generic Application Template architecture diagram. The diagram shows a User Application at the top, connected via a bidirectional arrow to the Generic Application Template. The Generic Application Template is a large container with a rounded rectangle inside labeled 'Generic Application Resource Manager (Generic ARM)'. To the left of the template is a Node Controller, connected to the template by a bidirectional arrow. Below the template is a large shaded area containing two rounded rectangles: 'Generic Conference Control (GCC) Rec. T.124' on top and 'Multipoint Communication Service (MCS) Rec. T.122/T.125' on the bottom. They are connected by a bidirectional arrow. Arrows also connect the Node Controller to both the GCC and MCS blocks, and the Generic ARM to both the GCC and MCS blocks.](a83ba9e3e2c1e21dd69953a7b09e45b4_img.jpg)
+
+```
+
+graph TD
+    UA[User Application] <--> GAT
+    subgraph GAT [Generic Application Template]
+        GARMA[Generic Application Resource Manager  
+(Generic ARM)]
+    end
+    NC[Node Controller] <--> GAT
+    subgraph Services [ ]
+        GCC[Generic Conference Control (GCC)  
+Rec. T.124] <--> MCS[Multipoint Communication Service (MCS)  
+Rec. T.122/T.125]
+    end
+    NC --> GCC
+    NC --> MCS
+    GARMA --> GCC
+    GARMA --> MCS
+
+```
+
+Figure 5/T.121: Generic Application Template architecture diagram. The diagram shows a User Application at the top, connected via a bidirectional arrow to the Generic Application Template. The Generic Application Template is a large container with a rounded rectangle inside labeled 'Generic Application Resource Manager (Generic ARM)'. To the left of the template is a Node Controller, connected to the template by a bidirectional arrow. Below the template is a large shaded area containing two rounded rectangles: 'Generic Conference Control (GCC) Rec. T.124' on top and 'Multipoint Communication Service (MCS) Rec. T.122/T.125' on the bottom. They are connected by a bidirectional arrow. Arrows also connect the Node Controller to both the GCC and MCS blocks, and the Generic ARM to both the GCC and MCS blocks.
+
+T0825040-95/d05
+
+FIGURE 5/T.121  
+**Generic Application Template**
+
+A description of functionality provided by a Generic ARM is described below.
+
+## 6.1 Initialization
+
+An ARM is responsible for enrolling its Application Protocol Entity on behalf of the user application, and for obtaining the necessary resources required by the ASE. For each application protocol employed, the user application must specify the following parameters to the corresponding ARM:
+
+- Whether it wishes to enroll or not (no further parameters are required if user application does not wish to enroll).
+- Application protocol key.
+- Session type (registration, standard base, non-standard base, public or private).
+- Session ID (omitted if declaring support of a protocol through the registration session, enrolling in a non-standard base session or creating a new public or private session).
+- List of dynamic tokens required.
+- List of assigned channels required.
+- List of private channels required (and optionally, nodes to be invited to those channels).
+- Whether it is able to act as the application session conductor (if there is more than one application at a site participating in the same session, the local GCC provider shall determine which shall become conductor).
+- List of application capabilities supported (as defined in the application protocol specification). Collapsing capabilities should be omitted for the registration session, but should be included for all other sessions.
+
+Table 2 specifies the parameters that are passed to the ARM for each application protocol employed by the user application.
+
+## 6.2 Enrollment
+
+In order to participate in a conference, a user application requires an APE (consisting of an ARM and an ASE) for each protocol it employs. The method of creating APEs is a local matter, outside the scope of this Recommendation. Each APE must then, in turn, establish a GCC SAP to allow it to communicate with the GCC provider at that node; again, how this is achieved is a local matter. Similarly, each APE must establish an MCSAP to allow it to communicate with its local MCS Provider.
+
+When the node joins a conference, or an APE establishes a GCC SAP subsequent to joining one or more conferences, the local GCC provider notifies all APEs at that node by issuing a GCC-Application-Permission-to-Enroll indication with the Grant/Revoke flag set to Grant. For each protocol employed by the user application, the respective ARM shall then issue a GCC-Application-Enroll request, regardless of whether the user application wishes to enroll at that time. If the user application does not wish to enroll an APE, the corresponding ARM shall specify the conference ID and set the Enroll/Un-enroll flag in the GCC-Application-Enroll request to Un-enroll. No other parameters are required. The user application may instruct its ARM(s) to enroll at any time subsequently, unless permission is revoked by receipt of a GCC-Application-Permission-to-Enroll indication with the Grant/Revoke flag set to Revoke.
+
+A user application may wish to receive information on all sessions in progress before deciding whether to participate in an existing session or to create a new session. It may do this by instructing its ARM(s) to enroll Inactive in the registration session as described in 6.2.1.
+
+If the user application wishes to alert peer applications at other nodes to its presence but does not wish to participate in a session immediately, it may instruct its ARM to enroll inactive in the registration session without an MCS User ID. This enables the user application to declare support of one or more protocols without consuming MCS resources.
+
+TABLE 2/T.121
+
+### **APE parameters**
+
+| Parameter                | Description                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
+|--------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Enroll/Un-enroll         | This parameter is set to ENROLL if the user application wishes to enroll immediately and to UN-ENROLL if the user application wishes to withdraw enrolment. If set to UN-ENROLL, no further parameters are required.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
+| Application-protocol-key | The Application Protocol Key identifies the Application Protocol used in an Application Protocol Session. Multiple Application Protocol Sessions with the same purpose are identified using the same Application Protocol Key (but different Session IDs). An Application Protocol Key is either an ASN.1 OBJECT IDENTIFIER belonging to a Recommendation, Standard, or non-standard protocol, or, alternatively, it is a non-standard identifier using the encoding conventions of Recommendation T.124 (which uses T.35 country codes like Recommendation H.221).                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
+| SessionType              | <p>This parameter can have one of the following five values:</p> <p><i>registration</i>: The registration session allows a user application to advertise its presence to the conference and also provides a means of locating the non-standard base session. No sessionID is required</p> <p><i>standard base</i>: This value indicates that the ARM should enroll using a Session Key composed of the application protocol key and the sessionID parameter. It shall use the static predefined channel(s) and static token(s) as defined in the application protocol specification and assigned in Recommendation T.120 as the basic set of resources. This session type is only valid for standardized application protocols</p> <p><i>non-standard base</i>: This value indicates that the ARM should first enroll in the registration session to determine the sessionID assigned to the non-standard base session by consulting the GCC Registry. If a sessionID does not already exist, one is assigned by the ARM. The ARM shall then enroll in the non-standard base session using a Session Key composed of the application protocol key and the sessionID parameter. Members of a non-standard base session may determine Token and Channel IDs via the GCC Registry. This session type is only valid for non-standard application protocols</p> <p><i>public</i>: This value indicates that the ARM should enroll using a Session Key composed of the application protocol key and the sessionID parameter. If the sessionID parameter is omitted, one is assigned by the ARM. All channel and token resources are dynamic and are allocated by the creator of the public session using the MCS-Channel-Join and GCC-Registry-Assign-Token mechanisms respectively. Members of a public session may determine Token and Channel IDs via the GCC Registry</p> <p><i>private</i>: This value indicates that the ARM should enroll using a Session Key composed of the application protocol key and the sessionID parameter. If the sessionID is omitted, one is assigned by the ARM. All channel and token resources are dynamic and are allocated by the Private Convenor ARM using the MCS-Channel-Convene and GCC-Registry-Assign-Token mechanisms respectively. The ARM creating the session may then admit to the channel(s) peer APEs at the nodes whose GCC Node Ids are present in the admitList protocol parameter.</p> <p>A Private Member ARM must wait for its APE to be admitted by the convenor of the private MCS channels before attempting to join them</p> |
+| SessionID                | <p>This parameter is used to differentiate the resources used by multiple sessions of the protocol that may be in existence simultaneously within the same MCS domain.</p> <p>The sessionID must be specified if the user application wishes to participate in a standard base session or in an existing public or private session. It is omitted if the user application wishes to create a new public or private session, participate in a non-standard base session, or if the user application wishes to enroll in the registration session without consuming MCS resources. With the exception of the registration session, the MCS Channel ID assigned as a start-up channel is used as the sessionID, since this is guaranteed to be unique within the conference domain.</p>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
+
+TABLE 2/T.121 (concluded)
+
+### **APE parameters**
+
+| Parameter                        | Description                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
+|----------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| AdmitList                        | <p>SessionType = private and sessionID omitted</p> <p>List of GCC NodeIDs corresponding to the Nodes at which peer APEs are to be admitted to the privately convened channels.</p> <p>Else</p> <p>Omitted</p>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
+| ResourceList                     | <p>This is a list of resources (channels, tokens, registry parameters and handles) required by the user application.</p> <p>SessionType = standard base:</p> <p>Resource List comprises the MCS IDs of static channels to be joined by the APE and static tokens to be used by the APE. It may optionally contain a list of Resource Ids for determining the MCS IDs of dynamic channels and tokens via the GCC Registry. It may also specify the number of Registry handles required and include a list of Resource Ids for Registry parameters and value of those parameters (where appropriate).</p> <p>SessionType = public, private, or non-standard base:</p> <p>Resource List comprises a list of Resource Ids for determining the MCS IDs of dynamic channels and tokens via the GCC Registry. It may also specify the number of Registry handles required and include a list of Resource Ids for Registry parameters and value of those parameters (where appropriate). If the Session ID is omitted (i.e. the APE is the session convenor), the ARM is responsible for assigning and registering all channels and tokens specified in the Resource List. If the Session ID is present (i.e. the APE is a session member), the ARM is responsible for retrieving all channels and tokens. In both cases, the Resource ID and associated MCS Channel ID or Token ID are passed by the ARM to its ASE.</p> <p>SessionType = registration</p> <p>Omitted</p> |
+| Conducting Operation Capable     | Set if the APE is capable of becoming the session Conductor in conducted mode                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
+| Non-Collapsing Capabilities List | Any non-collapsing capabilities specified by the application protocol and supported by the ASE                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
+| Application Capability List      | Any collapsing capabilities specified by the application protocol and supported by the ASE                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
+| Expected Capability List         | <p>SessionType = private and sessionID omitted:</p> <p>Indicates any application capabilities that must be supported by invoked APEs, allowing the creator of a private session to specify a minimum capability set for that session.</p> <p>Else</p> <p>Omitted</p>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
+
+When the application decides to become active, each ARM must adopt an MCS User ID. A new MCS User ID is acquired by the ARM issuing an MCS-Attach-User request to the MCS provider, using the Conference ID contained in the GCC-Application-Permission-to-Enroll indication as the Domain Selector. On receipt of a successful MCS-Attach-User confirm in response, an ARM shall join the User ID channel indicated by issuing an MCS-Channel-Join request and supply the User ID to the corresponding ASE.
+
+Subsequent operations are dependent on the session type. Note that the processes described need to be repeated for each APE employed by a user application. Observe that a common feature of the model templates (with the exception of the registration session template) is that the Session ID channel is the start-up channel, its type determines the session type, and it is always joined during the initiation sequence of an APE.
+
+The procedures defined for session enrollment and joining the start-up channel must be followed in the order specified for each of the session types described. If an application protocol does not require the use of any further resources (channels, tokens or registry parameters), an ARM may omit the inactive enrollment operation. Where an application protocol makes use of tokens, registry parameters or additional dynamic channels, this Recommendation imposes no requirement on the order of assigning or identifying those resources. If an application protocol makes use of GCC handles, these may be allocated during the application enrollment process and at any time subsequently during the lifetime of a session.
+
+To minimize the initialization period it is permissible to identify multiple channels in parallel by interleaving the operations required for each channel. For example, a session creator may choose to convene all required channels and then register all those channels, rather than convening and registering each channel separately. For any given channel, however, the sequence of operations defined in this Recommendation must be followed.
+
+An APE can only be considered to be part of a session when its ARM receives a GCC-Application-Roster-Report indication in which its Entity ID is present. An APE shall not submit data to a session until it receives such a roster report indication. However, APEs should be prepared to buffer all data received for a session between enrolling active in a session and receiving a roster report in which the APE Entity ID is present. This is because another APE may have received a roster report indication containing the new participant and submit data to the session which reaches the new participant before the corresponding roster report. Application protocols may specify how this buffered data is to be processed.
+
+### 6.2.1 Registration session
+
+If the user application wishes to alert peer applications at other nodes to its presence, but does not wish to participate in a session immediately, it may instruct its ARM to enroll in the registration session without an MCS User ID. This enables the user application to declare support of one or more application protocols without consuming MCS resources. It also receives information on all sessions in progress for each of the application protocols advertised. Each ARM issues a GCC-Application-Enroll request with the Enroll/Un-enroll flag set to Enroll and the Active/Inactive flag set to Inactive, specifying the Session Key of its respective protocol without a Session ID. See Figure 6.
+
+![Sequence diagram showing the process of enrolling in a registration session. The diagram involves five lifelines: Local APE, Local GCC Provider, Local MCS Provider, Remote MCS Provider(s), and Remote GCC Provider(s). The Local APE sends a GCC-Application-Permission-To-Enroll.ind to the Local GCC Provider. The Local GCC Provider sends a GCC-Application-Enroll.req [Inactive, without Session ID] to the Local MCS Provider. The Local MCS Provider sends a GCC-Application-Enroll.con to the Local APE. The Local APE sends a GCC-Application-Roster-Report.ind to the Local GCC Provider. The Local GCC Provider sends a GCC-Application-Roster-Report.ind to the Remote GCC Provider(s). The Remote GCC Provider(s) sends a GCC-Application-Roster-Report.ind to the Remote APE(s). The Remote APE(s) performs the operation 'Enroll inactive in registration session'.](3da1a07cb87051bf616c9876db958cf0_img.jpg)
+
+```
+
+sequenceDiagram
+    participant LA as Local APE
+    participant LGP as Local GCC Provider
+    participant LMP as Local MCS Provider
+    participant RMP as Remote MCS Provider(s)
+    participant RGP as Remote GCC Provider(s)
+    participant RAP as Remote APE(s)
+
+    LA->>LGP: GCC-Application-Permission-To-Enroll.ind
+    LGP->>LMP: GCC-Application-Enroll.req [Inactive, without Session ID]
+    LMP->>LA: GCC-Application-Enroll.con
+    LA->>LGP: GCC-Application-Roster-Report.ind
+    LGP->>RGP: GCC-Application-Roster-Report.ind
+    RGP->>RAP: GCC-Application-Roster-Report.ind
+    RAP->>RAP: Enroll inactive in registration session
+  
+```
+
+T0825360-96/d06
+
+Sequence diagram showing the process of enrolling in a registration session. The diagram involves five lifelines: Local APE, Local GCC Provider, Local MCS Provider, Remote MCS Provider(s), and Remote GCC Provider(s). The Local APE sends a GCC-Application-Permission-To-Enroll.ind to the Local GCC Provider. The Local GCC Provider sends a GCC-Application-Enroll.req [Inactive, without Session ID] to the Local MCS Provider. The Local MCS Provider sends a GCC-Application-Enroll.con to the Local APE. The Local APE sends a GCC-Application-Roster-Report.ind to the Local GCC Provider. The Local GCC Provider sends a GCC-Application-Roster-Report.ind to the Remote GCC Provider(s). The Remote GCC Provider(s) sends a GCC-Application-Roster-Report.ind to the Remote APE(s). The Remote APE(s) performs the operation 'Enroll inactive in registration session'.
+
+FIGURE 6/T.121  
+Enrolling in the registration session to declare support of a protocol
+
+### 6.2.2 Standard base session
+
+After joining its User ID Channel, the ARM shall join static channels as specified in the corresponding application protocol specification. Once positive confirmation of joining these channels has been received, the ARM shall enroll the APE Inactive by issuing a GCC-Application-Enroll request to the GCC provider, with the parameters specified in Table 3.
+
+After receiving a GCC-Application-Roster-Report indication with an entry corresponding to its APE, the ARM shall assign any dynamic assigned channels mandated by the protocol specification. The ARM shall issue a GCC-Registry-Retrieve-Entry request primitive for each such channel to determine whether it has already been registered. If the Result parameter returned in the GCC-Registry-Retrieve-Entry confirm is “successful”, then the ARM shall attempt to join the channel indicated in the Registry Item parameter by issuing an MCS-Channel-Join request. If the Result parameter returned in the GCC-Registry-Retrieve-Entry is “entry not found”, the ARM shall attempt to assign a new channel by issuing an MCS-Channel-Join request with Channel ID = 0. The returned MCS-Channel-Join confirm, if successful, contains the assigned Channel ID which the ARM will attempt to register in the standard base session by issuing a GCC-Registry-Register-Channel request. On receipt of the GCC-Registry-Register-Channel confirm, the ARM shall examine the result parameter. If the result is “successful”, the ARM shall take no further action. If the result is “index already exists”, then the channel has already been registered by another APE; its Channel ID is provided in the Registry Item parameter. In this case, the ARM shall first leave the channel it had previously assigned by issuing an MCS-Channel-Leave request specifying the Channel ID returned in the MCS-Channel-Join confirm. It shall then join the channel indicated in the Registry Item parameter by issuing an MCS-Channel-Join request.
+
+If the application protocol mandates that an APE must identify any dynamic tokens before interacting with its peers, the ARM may determine their identity via the GCC Registry. For each Token Resource ID specified by the application protocol, the ARM shall issue a GCC-Registry-Assign-Token request to the GCC provider using the parameters specified in Table 7. If the Result parameter returned in the GCC-Registry-Assign-Token confirm is “successful” or “index already exists” the Token ID contained in the Registry Item of the returned confirm primitive is used as the Token ID for the token corresponding to the Resource ID used in the Registry Key. The ARM shall pass the Resource ID and associated Token ID to its ASE.
+
+If the application protocol requires an APE to assign or identify registry parameters before interacting with its peers, the ARM shall issue a GCC-Registry-Set-Parameter request to the GCC Provider.
+
+Once all resources required for the session have been identified, the ARM shall then enroll Active by issuing a GCC-Application-Enroll request. The Active/Inactive flag shall be set to Active, the Session ID shall be specified as part of the Session Key, the Start-Up Channel shall be specified as Static and the capability lists shall be provided. See Figures 7 and 8.
+
+### 6.2.3 Non-standard base session
+
+The registration session may be used to provide access to a non-standard base session. After joining its User ID Channel, the ARM shall enroll in the registration session by issuing a GCC-Application-Enroll request with the Active/Inactive flag set to Inactive and specifying the Session Key with no Session ID.
+
+After receiving a GCC-Application-Roster-Report indication with an entry corresponding to its APE, the ARM shall attempt to create the non-standard base session by first issuing an MCS-Channel-Join request with Channel ID = 0. The returned MCS-Channel-Join confirm, if successful, contains the assigned Channel ID which the ARM will attempt to register in the registration session as the start-up channel for the non-standard base session. The ARM shall issue a GCC-Registry-Register-Channel request using a Registry Key comprised of the Session Key (with no Session ID) and the Resource ID “BASE” encoded as a four consecutive octets according to Recommendation T.50. On receipt of the GCC-Registry-Register-Channel confirm, the ARM shall examine the result parameter.
+
+If the result is “index already exists”, then the non-standard base session has already been registered by another APE; its Session ID is provided in the Registry Item parameter. In this case, the ARM shall first leave the channel it had previously assigned by issuing an MCS-Channel-Leave request specifying the Channel ID returned in the MCS-Channel-Join confirm. The ARM shall then assume the role of session member and enroll in the existing base session by following the process described for a public session member in 6.2.4. This process is illustrated in Figure 9. An attempt to join the start-up channel identified in the GCC-Registry-Register-Channel confirm may fail if the Registry Item parameter points to a defunct non-standard session (i.e. the session’s start-up channel no longer exists); in such circumstances the ARM may attempt to reuse this defunct session by issuing a GCC-Registry-Delete-Entry request, using the same Registry Key as before. On receipt of the corresponding GCC-Registry-Delete-Entry confirm, the ARM shall then examine the result parameter and if it is “successful”, the ARM may repeat the non-standard base session creation process.
+
+If the GCC-Registry-Register-Channel confirm result parameter is “successful”, the ARM shall assume the responsibility of creator for the non-standard base session as illustrated in Figure 10. It shall enroll Inactive in the new base session as specified in Table 3.
+
+![Sequence diagram showing the example standard base session protocol initiation sequence case 1: using only static resources. The diagram involves Local APE, Local GCC Provider, Local MCS Provider, Remote MCS Provider(s), Remote GCC Provider(s), and Remote APE(s).](d53cd0fd1cf896a9353fd63de1505ba2_img.jpg)
+
+```
+
+sequenceDiagram
+    participant LA as Local APE
+    participant LGP as Local GCC Provider
+    participant LMP as Local MCS Provider
+    participant RMP as Remote MCS Provider(s)
+    participant RGP as Remote GCC Provider(s)
+    participant RAP as Remote APE(s)
+
+    LGP->>LA: GCC-Application-Permission-To-Enroll.ind
+    LA->>LMP: MCS-ATTACH-USER.req
+    LMP->>LA: MCS-ATTACH-USER.con
+    Note over LA,LMP: [APE User ID = unique new]
+    LA->>LMP: MCS-CHANNEL-JOIN.req
+    Note over LA,LMP: [Channel ID = APE User ID]
+    LMP->>LA: MCS-CHANNEL-JOIN.con
+    LA->>LMP: MCS-CHANNEL-JOIN.req
+    Note left of LA: 1
+    LMP->>LA: MCS-CHANNEL-JOIN.con
+    Note left of LA: 2
+    LMP-->>RMP: Conditional
+    Note over LA,LMP: (Execute steps 1-2 as necessary for each channel required)
+    LA->>LGP: GCC-Application-Enroll.req
+    Note over LA,LGP: [Active, with Session ID]
+    LGP->>LA: GCC-Application-Enroll.con
+    LGP->>LA: GCC-Application-Roster-Report.ind
+    RGP->>RAP: GCC-Application-Roster-Report.ind
+
+```
+
+**Operation**
+
+---
+
+Obtain User ID for APE
+
+---
+
+Join channel(s) specified by protocol
+
+---
+
+Enroll active in chosen session
+
+T0825370-96/d07
+
+Sequence diagram showing the example standard base session protocol initiation sequence case 1: using only static resources. The diagram involves Local APE, Local GCC Provider, Local MCS Provider, Remote MCS Provider(s), Remote GCC Provider(s), and Remote APE(s).
+
+FIGURE 7/T.121
+
+**Example standard base session protocol initiation sequence case 1: using only static resources**
+
+![Sequence diagram for Example standard base session protocol initiation sequence case 2: using static and dynamic resources. The diagram shows interactions between Local APE, Local GCC Provider, Local MCS Provider, Remote MCS Provider(s), Remote GCC Provider(s), and Remote APE(s). The sequence includes steps for user attachment, channel joining, enrollment, registry retrieval, channel registration, token assignment, parameter setting, handle allocation, and final enrollment.](c914f51f4427bc672dd0526cfc90ebe9_img.jpg)
+
+The diagram illustrates the sequence of operations for a standard base session protocol initiation sequence case 2, involving static and dynamic resources. The participants are Local APE, Local GCC Provider, Local MCS Provider, Remote MCS Provider(s), Remote GCC Provider(s), and Remote APE(s). The operations are as follows:
+
+- Local APE** sends **GCC-Application-Permission-To-Enroll.ind** to **Local GCC Provider**.
+- Local GCC Provider** sends **MCS-ATTACH-USER.req** to **Local MCS Provider**.
+- Local MCS Provider** sends **MCS-ATTACH-USER.con** to **Local APE**.
+- Local APE** sends **[APE User ID = unique new] MCS-CHANNEL-JOIN.req** to **Local MCS Provider**.
+- Local MCS Provider** sends **[Channel ID = APE User ID] MCS-CHANNEL-JOIN.con** to **Local APE**.
+- Local APE** sends **MCS-CHANNEL-JOIN.req** to **Local MCS Provider**.
+- Local MCS Provider** sends **MCS-CHANNEL-JOIN.con** to **Local APE**.
+- Local APE** sends **GCC-Application-Enroll.req** to **Local GCC Provider**.
+- Local GCC Provider** sends **[Inactive, with Session ID] GCC-Application-Enroll.con** to **Local APE**.
+- Local APE** sends **GCC-Application-Roster-Report.ind** to **Local GCC Provider**.
+- Local GCC Provider** sends **GCC-Registry-Retrieve-Entry.req** to **Local MCS Provider**.
+- Local MCS Provider** sends **GCC-Registry-Retrieve-Entry.con** to **Local APE**.
+- Local APE** sends **MCS-CHANNEL-JOIN.req** to **Local MCS Provider**.
+- Local MCS Provider** sends **[Channel ID = GCC-Registry-Retrieve-Entry.con Registry Item] MCS-CHANNEL-JOIN.con** to **Local APE**.
+- Local APE** sends **MCS-CHANNEL-JOIN.req** to **Local MCS Provider**.
+- Local MCS Provider** sends **[Channel ID = 0] MCS-CHANNEL-JOIN.con** to **Local APE**.
+- Local APE** sends **[Assigned Channel ID = unique new] GCC-Registry-Register-Channel.req** to **Local GCC Provider**.
+- Local GCC Provider** sends **GCC-Registry-Register-Channel.con** to **Local APE**.
+- Local APE** sends **MCS-CHANNEL-LEAVE.req** to **Local MCS Provider**.
+- Local MCS Provider** sends **[Multicast Channel ID] MCS-CHANNEL-LEAVE.con** to **Local APE**.
+- Local APE** sends **MCS-CHANNEL-JOIN.req** to **Local MCS Provider**.
+- Local MCS Provider** sends **[Channel ID = GCC-Registry-Register-Channel.con Registry Item] MCS-CHANNEL-JOIN.con** to **Local APE**.
+- Local APE** sends **GCC-Registry-Assign-Token.req** to **Local GCC Provider**.
+- Local GCC Provider** sends **GCC-Registry-Assign-Token.con** to **Local APE**.
+- Local APE** sends **GCC-Registry-Set-Parameter.req** to **Local GCC Provider**.
+- Local GCC Provider** sends **GCC-Registry-Set-Parameter.con** to **Local APE**.
+- Local APE** sends **GCC-Registry-Allocate-Handle.req** to **Local GCC Provider**.
+- Local GCC Provider** sends **GCC-Registry-Allocate-Handle.con** to **Local APE**.
+- Local APE** sends **GCC-Application-Enroll.req** to **Local GCC Provider**.
+- Local GCC Provider** sends **[Active, with Session ID] GCC-Application-Enroll.con** to **Local APE**.
+- Local APE** sends **GCC-Application-Roster-Report.ind** to **Local GCC Provider**.
+- Local GCC Provider** sends **GCC-Application-Roster-Report.ind** to **Remote GCC Provider(s)**.
+- Remote GCC Provider(s)** sends **GCC-Application-Roster-Report.ind** to **Remote APE(s)**.
+
+Conditional operations and notes:
+
+- Conditional**: Steps 1-2 are executed as necessary for each channel required.
+- Conditional**: Steps 3-4 are executed if channel registered (Step 4 succeeds).
+- Conditional**: Steps 5-6 are executed if channel not registered (Step 4 fails).
+- Conditional**: Steps 7-8 are executed if channel registered (Step 10 fails).
+- Conditional**: Steps 9-10 are executed if channel not registered (Step 10 fails).
+- Conditional**: Steps 11-12 are executed if channel registered (Step 10 fails).
+- Conditional**: Steps 13-14 are executed if channel not registered (Step 10 fails).
+- Conditional**: Steps 15-16 are executed as necessary for each additional token required.
+- Conditional**: Steps 17-18 are executed as necessary for each additional parameter required.
+- Conditional**: Steps 19-20 are executed as necessary if handles required.
+
+Operations performed by Remote APE(s):
+
+- Obtain user ID for APE
+- Join channel(s) specified by protocol
+- Enroll inactive in chosen session
+- Determine if additional channel required by the protocol has been registered
+- Join additional channel if channel already registered
+- Create new channel if channel not already registered
+- Attempt to register new channel if channel not already registered
+- Leave channel if registration fails
+- Join channel identified if registration fails
+- Identify dynamic token required by the protocol
+- Assign/identify any parameter specified by protocol
+- Allocate handle(s) if required by protocol
+- Enroll active in chosen session
+
+Sequence diagram for Example standard base session protocol initiation sequence case 2: using static and dynamic resources. The diagram shows interactions between Local APE, Local GCC Provider, Local MCS Provider, Remote MCS Provider(s), Remote GCC Provider(s), and Remote APE(s). The sequence includes steps for user attachment, channel joining, enrollment, registry retrieval, channel registration, token assignment, parameter setting, handle allocation, and final enrollment.
+
+FIGURE 8/T.121
+
+Example standard base session protocol initiation sequence case 2: using static and dynamic resources
+
+TABLE 3/T.121
+
+#### **Parameters for GCC-Application-Enroll Request**
+
+| Parameter                                                                                                                   | Contents                                                                                                                                                                                                                                                                                                                                                                                                                                         |                                                                                                                             |
+|-----------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------|
+| Conference ID                                                                                                               | Provided by GCC-Application-Permission-To-Enroll indication                                                                                                                                                                                                                                                                                                                                                                                      |                                                                                                                             |
+| Session Key                                                                                                                 | Comprised of the Application Protocol key and the Session ID                                                                                                                                                                                                                                                                                                                                                                                     |                                                                                                                             |
+| Application User ID                                                                                                         | Provided by MCS-Attach-User confirm                                                                                                                                                                                                                                                                                                                                                                                                              |                                                                                                                             |
+| Active/Inactive                                                                                                             | <p>Active when indicating that the ARM has identified the set of resources that need to be identified as part of the enrollment process and joined all channels required by the protocol.</p> <p>Inactive for the registration session and in the case of standard base, non-standard base, public or private sessions when enrolling prior to identifying the set of resources that need to be identified as part of the enrollment process</p> |                                                                                                                             |
+| Conducting Operation Capable Flag                                                                                           | Set if the APE is capable of becoming the session Conductor in conducted mode. This flag must not be set if the Active/Inactive flag is set to Inactive                                                                                                                                                                                                                                                                                          |                                                                                                                             |
+| Start-Up Channel                                                                                                            | Optional parameter specifying the type of session as follows:                                                                                                                                                                                                                                                                                                                                                                                    |                                                                                                                             |
+|                                                                                                                             | <table> <tr> <td>           Session Type:<br/> <i>Registration</i><br/> <i>Standard Base</i><br/> <i>Non-Standard Base</i><br/> <i>Public</i><br/> <i>Private</i> </td><td>           Start-Up Channel:<br/> <i>Omitted</i><br/> <i>Static</i><br/> <i>Dynamic Multicast</i><br/> <i>Dynamic Multicast</i><br/> <i>Dynamic Private</i> </td></tr> </table>                                                                                       | Session Type:<br><i>Registration</i><br><i>Standard Base</i><br><i>Non-Standard Base</i><br><i>Public</i><br><i>Private</i> |
+| Session Type:<br><i>Registration</i><br><i>Standard Base</i><br><i>Non-Standard Base</i><br><i>Public</i><br><i>Private</i> | Start-Up Channel:<br><i>Omitted</i><br><i>Static</i><br><i>Dynamic Multicast</i><br><i>Dynamic Multicast</i><br><i>Dynamic Private</i>                                                                                                                                                                                                                                                                                                           |                                                                                                                             |
+| Non-Collapsing Capabilities List                                                                                            | Any non-collapsing capabilities specified by the application protocol and supported by the ASE                                                                                                                                                                                                                                                                                                                                                   |                                                                                                                             |
+| Application Capability List                                                                                                 | <p>Any collapsing capabilities specified by the application protocol and supported by the ASE.</p> <p>Omitted if Active/Inactive flag is set to Inactive</p>                                                                                                                                                                                                                                                                                     |                                                                                                                             |
+| Enroll/Un-enroll                                                                                                            | ENROLL                                                                                                                                                                                                                                                                                                                                                                                                                                           |                                                                                                                             |
+
+If any additional channels are mandated by the protocol specification, the ARM shall issue a GCC-Registry-Retrieve-Entry request primitive for each such channel to determine whether it has already been registered. The Registry Key used to register these resources shall include the Session ID of the non-standard base session as part of the Session Key. If the Result parameter returned in the GCC-Registry-Retrieve-Entry confirm is “successful”, then the ARM shall attempt to join the channel indicated in the Registry Item parameter by issuing an MCS-Channel-Join request. If the Result parameter returned in the GCC-Registry-Retrieve-Entry is “entry not found”, the ARM shall attempt to assign a new channel by issuing an MCS-Channel-Join request with Channel ID = 0. The returned MCS-Channel-Join confirm, if successful, contains the assigned Channel ID which the ARM will attempt to register in the non-standard base session by issuing a GCC-Registry-Register-Channel request. On receipt of the GCC-Registry-Register-Channel confirm, the ARM shall examine the result parameter. If the result is “successful”, the ARM shall take no further action. If the result is “index already exists”, then the channel has already been registered by another APE; its Channel ID is provided in the Registry Item parameter. In this case, the ARM shall first leave the channel it had previously assigned by issuing an MCS-Channel-Leave request specifying the Channel ID returned in the MCS-Channel-Join confirm. It shall then join the channel indicated in the Registry Item parameter by issuing an MCS-Channel-Join request.
+
+
+
+![Sequence diagram for Example non-standard base session protocol initiation sequence case 2: base session not already registered. The diagram shows interactions between Local APE, Local GCC Provider, Local MCS Provider, Remote MCS Provider(s), Remote GCC Provider(s), and Remote APE(s). The sequence includes steps for user enrollment, channel registration, token assignment, and parameter setting, with conditional paths for channel registration success or failure.](cbdfdade780e677eb1c1aef3081ce9ef_img.jpg)
+
+**Local APE**      **Local GCC Provider**      **Local MCS Provider**      **Remote MCS Provider(s)**      **Remote GCC Provider(s)**      **Remote APE(s)**      **Operation**
+
+1. Local APE → Local GCC Provider: GCC-Application-Permission-To-Enroll.ind
+
+2. Local GCC Provider → Local MCS Provider: MCS-ATTACH-USER.req
+
+3. Local MCS Provider → Local GCC Provider: MCS-ATTACH-USER.con
+
+4. Local GCC Provider → Local MCS Provider: [APE User ID = unique new] MCS-CHANNEL-JOIN.req
+
+5. Local MCS Provider → Local GCC Provider: [Channel ID = APE User ID] MCS-CHANNEL-JOIN.con
+
+6. Local APE → Local GCC Provider: GCC-Application-Enroll.req
+
+7. Local GCC Provider → Local APE: [Inactive, no Session ID] GCC-Application-Enroll.con
+
+8. Local APE → Local GCC Provider: GCC-Application-Roster-Report.ind
+
+9. Local GCC Provider → Remote GCC Provider(s): GCC-Application-Roster-Report.ind
+
+10. Remote GCC Provider(s) → Remote APE(s): Report.ind
+
+11. Remote APE(s) → Remote GCC Provider(s): Report.ind
+
+12. Remote GCC Provider(s) → Remote APE(s): Report.ind
+
+13. Local APE → Local GCC Provider: GCC-Registry-Register-Channel.req[BASE ]
+
+14. Local GCC Provider → Local MCS Provider: GCC-Registry-Register-Channel.req[BASE ]
+
+15. Local MCS Provider → Local GCC Provider: GCC-Registry-Register-Channel.con [Result=successful]
+
+16. Local APE → Local GCC Provider: GCC-Application-Enroll.req
+
+17. Local GCC Provider → Local APE: [Inactive, with Session ID] GCC-Application-Enroll.con
+
+18. Local APE → Local GCC Provider: GCC-Application-Roster-Report.ind
+
+19. Local GCC Provider → Remote GCC Provider(s): GCC-Application-Roster-Report.ind
+
+20. Remote GCC Provider(s) → Remote APE(s): Report.ind
+
+21. Remote APE(s) → Remote GCC Provider(s): Report.ind
+
+22. Remote GCC Provider(s) → Remote APE(s): Report.ind
+
+23. Local APE → Local GCC Provider: GCC-Registry-Retrieve-Entry.req
+
+24. Local GCC Provider → Local MCS Provider: GCC-Registry-Retrieve-Entry.req
+
+25. Local MCS Provider → Local GCC Provider: GCC-Registry-Retrieve-Entry.con
+
+26. Local GCC Provider → Local MCS Provider: MCS-CHANNEL-JOIN.req
+
+27. Local MCS Provider → Local GCC Provider: [Channel ID = GCC-Registry-Retrieve-Entry.con Registry Item] MCS-CHANNEL-JOIN.con
+
+28. Local GCC Provider → Local MCS Provider: MCS-CHANNEL-JOIN.req
+
+29. Local MCS Provider → Local GCC Provider: [Channel ID = 0] MCS-CHANNEL-JOIN.con
+
+30. Local GCC Provider → Local MCS Provider: [Assigned Channel ID = unique new] MCS-CHANNEL-JOIN.req
+
+31. Local MCS Provider → Local GCC Provider: [Assigned Channel ID = unique new] MCS-CHANNEL-JOIN.con
+
+32. Local APE → Local GCC Provider: GCC-Registry-Register-Channel.req
+
+33. Local GCC Provider → Local MCS Provider: GCC-Registry-Register-Channel.req
+
+34. Local MCS Provider → Local GCC Provider: GCC-Registry-Register-Channel.con
+
+35. Local APE → Local GCC Provider: MCS-CHANNEL-LEAVE.req
+
+36. Local GCC Provider → Local MCS Provider: [Assigned Channel ID] MCS-CHANNEL-LEAVE.con
+
+37. Local MCS Provider → Local GCC Provider: MCS-CHANNEL-LEAVE.con
+
+38. Local APE → Local GCC Provider: MCS-CHANNEL-JOIN.req
+
+39. Local GCC Provider → Local MCS Provider: [Channel ID = GCC-Registry-Register-Channel.con Registry Item] MCS-CHANNEL-JOIN.con
+
+40. Local MCS Provider → Local GCC Provider: MCS-CHANNEL-JOIN.con
+
+41. Local APE → Local GCC Provider: (Execute steps 1-12 as necessary for each additional channel required)
+
+42. Local GCC Provider → Local MCS Provider: (Execute steps 1-12 as necessary for each additional channel required)
+
+43. Local MCS Provider → Local GCC Provider: (Execute steps 1-12 as necessary for each additional channel required)
+
+44. Local APE → Local GCC Provider: GCC-Registry-Assign-Token.req
+
+45. Local GCC Provider → Local MCS Provider: GCC-Registry-Assign-Token.req
+
+46. Local MCS Provider → Local GCC Provider: GCC-Registry-Assign-Token.con
+
+47. Local GCC Provider → Local MCS Provider: GCC-Registry-Assign-Token.con
+
+48. Local APE → Local GCC Provider: GCC-Registry-Set-Parameter.req
+
+49. Local GCC Provider → Local MCS Provider: GCC-Registry-Set-Parameter.req
+
+50. Local MCS Provider → Local GCC Provider: GCC-Registry-Set-Parameter.con
+
+51. Local GCC Provider → Local MCS Provider: GCC-Registry-Set-Parameter.con
+
+52. Local APE → Local GCC Provider: GCC-Registry-Allocate-Handle.req
+
+53. Local GCC Provider → Local MCS Provider: GCC-Registry-Allocate-Handle.req
+
+54. Local MCS Provider → Local GCC Provider: GCC-Registry-Allocate-Handle.con
+
+55. Local GCC Provider → Local MCS Provider: GCC-Registry-Allocate-Handle.con
+
+56. Local APE → Local GCC Provider: GCC-Application-Enroll.req
+
+57. Local GCC Provider → Local APE: [Active, with Session ID] GCC-Application-Enroll.con
+
+58. Local APE → Local GCC Provider: GCC-Application-Roster-Report.ind
+
+59. Local GCC Provider → Remote GCC Provider(s): GCC-Application-Roster-Report.ind
+
+60. Remote GCC Provider(s) → Remote APE(s): Report.ind
+
+61. Remote APE(s) → Remote GCC Provider(s): Report.ind
+
+62. Remote GCC Provider(s) → Remote APE(s): Report.ind
+
+**Operations:**
+
+- Obtain User ID for the APE
+- Enroll inactive in registration session
+- Assign session identifier channel
+- Attempt to register session identifier channel as non-standard base session
+- Registration succeeds so enroll inactive in new non-standard base session
+- Determine if additional channel required by the protocol has been registered
+- Join additional channel if channel already registered
+- Create new channel if channel not already registered
+- Attempt to register new channel if channel not already registered
+- Leave channel if registration fails
+- Join channel identified if registration fails
+- Identify any token required by the protocol
+- Assign/identify any parameter specified by protocol
+- Allocate handle(s) if required by protocol
+- Enroll active in new non-standard base session
+
+T0825400-96/d10
+
+Sequence diagram for Example non-standard base session protocol initiation sequence case 2: base session not already registered. The diagram shows interactions between Local APE, Local GCC Provider, Local MCS Provider, Remote MCS Provider(s), Remote GCC Provider(s), and Remote APE(s). The sequence includes steps for user enrollment, channel registration, token assignment, and parameter setting, with conditional paths for channel registration success or failure.
+
+FIGURE 10/T.121
+
+#### **Example non-standard base session protocol initiation sequence case 2: base session not already registered**
+
+If the application protocol mandates that an APE must know the identity of tokens before interacting with its peers, the ARM may determine their identity via the GCC Registry. For each Token Resource ID specified by the application protocol, the ARM shall issue a GCC-Registry-Assign-Token request to the GCC provider using the parameters specified in Table 7. If the Result parameter returned in the GCC-Registry-Assign-Token confirm is “successful” or “index already exists” the Token ID contained in the Registry Item of the returned confirm primitive is used as the Token ID for the token corresponding to the Resource ID used in the Registry Key. The ARM shall pass the Resource ID and associated Token ID to its ASE.
+
+If the application protocol requires an APE to assign or identify registry parameters before interacting with its peers, the ARM shall issue a GCC-Registry-Set-Parameter request to the GCC Provider.
+
+Once all resources required for the session have been identified, the ARM shall then enroll Active by issuing a GCC-Application-Enroll request with the parameters specified in Table 3.
+
+### **6.2.4 Public session**
+
+After joining its User ID Channel, the ARM shall examine the session ID parameter to determine, if it is present, to participate in an existing public session (as a public member) or, if it is omitted, to create a new one (as a public creator). See Figures 11 and 12.
+
+If the sessionID parameter is present, the ARM shall enroll in the session indicated by issuing a GCC-Application-Enroll request with the Active/Inactive flag set to Inactive and specifying the Session Key with the requisite Session ID. It shall then issue an MCS-Channel-Join request, specifying the Session ID of the chosen session as the Channel ID parameter.
+
+If the application protocol requires multiple channels to be joined before an APE can be considered to be an active participant in a session, then the ARM shall attempt to identify and join these channels using the services of the GCC Registry and MCS respectively. Further channels may be joined as required when the application session is in progress. Likewise, if an application protocol mandates that an APE must know the identity of tokens or registry parameters before interacting with its peers, the ARM may determine their identity via the GCC Registry.
+
+Once all resources required for the session have been identified, the ARM shall then enroll Active in the chosen session by issuing a GCC-Application-Enroll request with the parameters specified in Table 3.
+
+If the sessionID parameter is omitted, the ARM shall enroll in a new public session. The ARM shall first allocate an assigned channel for the session by issuing an MCS-Channel-Join request with Channel ID = 0. The returned MCS-Channel-Join confirm, if successful, contains the assigned Channel ID. This Channel ID is also used as the Session ID for the APE. The ARM shall then enroll Inactive in this session by issuing a GCC-Application-Enroll request with the parameters specified in Table 3.
+
+The onus of acquiring the set of resources that need to be identified as part of the enrollment process for a public session rests with the ARM that created the session. If any additional channels, registry parameters or tokens are mandated by the protocol specification, the ARM should assign these and register them with GCC as necessary. The Registry Key used to register these resources shall include the Session ID as part of the Session Key. Note that the ARM must not attempt to use the GCC-Registry until it has received a GCC-Application-Roster-Report indication containing an entry corresponding to its own APE.
+
+Once all resources have been successfully assigned, the ARM shall enroll Active by issuing a GCC-Application-Enroll request with the parameters specified in Table 3.
+
+![Sequence diagram for Example public session protocol initiation sequence case 1: session member. The diagram shows interactions between Local APE, Local GCC Provider, Local MCS Provider, Remote MCS Provider(s), Remote GCC Provider(s), and Remote APE(s). The sequence includes steps for user attachment, channel joining, enrollment (inactive and active), and token/parameter assignment, with conditional paths for additional channels and tokens.](8c348bf9c2c81b018017ae1d19506a9a_img.jpg)
+
+```
+
+sequenceDiagram
+    participant LA as Local APE
+    participant LGP as Local GCC Provider
+    participant LMP as Local MCS Provider
+    participant RMP as Remote MCS Provider(s)
+    participant RGP as Remote GCC Provider(s)
+    participant RAP as Remote APE(s)
+
+    LGP->>LA: GCC-Application-Permission-To-Enroll.ind
+    LA->>LMP: MCS-ATTACH-USER.req
+    LMP->>LA: MCS-ATTACH-USER.con
+    LA->>LMP: [APE User ID = unique new] MCS-CHANNEL-JOIN.req
+    LMP->>LA: [Channel ID = APE User ID] MCS-CHANNEL-JOIN.con
+    Note right of LA: Obtain User ID for the APE
+    LA->>LGP: GCC-Application-Enroll.req
+    LGP->>LA: [Inactive, with Session ID] GCC-Application-Enroll.con
+    Note right of LA: Enroll inactive in chosen session
+    LA->>LGP: GCC-Application-Roster-Report.ind
+    LGP->>RGP: GCC-Application-Roster-Report.ind
+    LA->>LMP: MCS-CHANNEL-JOIN.req
+    LMP->>LA: [Session Identifier Channel ID = Chosen Session ID] MCS-CHANNEL-JOIN.con
+    Note right of LA: Join session identifier channel of chosen public session
+    LA->>LGP: 1 GCC-Registry-Retrieve-Entry.req
+    LGP->>LA: 2 GCC-Registry-Retrieve-Entry.con
+    Note right of LA: Identify any additional Channel using the GCC Registry
+    LA->>LMP: 3 MCS-CHANNEL-JOIN.req
+    LMP->>LA: 4 MCS-CHANNEL-JOIN.con
+    Note right of LA: Join additional channel
+    Note over LA, LMP: (Execute steps 1-4 as necessary for each additional channel required)
+    LA->>LGP: 5 GCC-Registry-Assign-Token.req
+    LGP->>LA: 6 GCC-Registry-Assign-Token.con
+    Note right of LA: Identify any token required by the protocol
+    Note over LA, LGP: (Execute steps 5-6 as necessary for each token required)
+    LA->>LGP: 7 GCC-Registry-Set-Parameter.req
+    LGP->>LA: 8 GCC-Registry-Set-Parameter.con
+    Note right of LA: Assign/identify any parameter specified by protocol
+    Note over LA, LGP: (Execute steps 7-8 as necessary for each parameter required)
+    LA->>LGP: GCC-Registry-Allocate-Handle.req
+    LGP->>LA: GCC-Registry-Allocate-Handle.con
+    Note right of LA: Allocate handle(s) if required by protocol
+    LA->>LGP: GCC-Application-Enroll.req
+    LGP->>LA: [Active, with Session ID] GCC-Application-Enroll.con
+    Note right of LA: Enroll active in chosen session
+    LA->>LGP: GCC-Application-Roster-Report.ind
+    LGP->>RGP: GCC-Application-Roster-Report.ind
+    RGP->>RAP: GCC-Application-Roster-Report.ind
+  
+```
+
+Local APE
+
+Local GCC Provider
+
+Local MCS Provider
+
+Remote MCS Provider(s)
+
+Remote GCC Provider(s)
+
+Remote APE(s)
+
+Operation
+
+Obtain User ID for the APE
+
+Enroll inactive in chosen session
+
+Join session identifier channel of chosen public session
+
+Identify any additional Channel using the GCC Registry
+
+Join additional channel
+
+Identify any token required by the protocol
+
+Assign/identify any parameter specified by protocol
+
+Allocate handle(s) if required by protocol
+
+Enroll active in chosen session
+
+T0825410-96/d11
+
+Sequence diagram for Example public session protocol initiation sequence case 1: session member. The diagram shows interactions between Local APE, Local GCC Provider, Local MCS Provider, Remote MCS Provider(s), Remote GCC Provider(s), and Remote APE(s). The sequence includes steps for user attachment, channel joining, enrollment (inactive and active), and token/parameter assignment, with conditional paths for additional channels and tokens.
+
+FIGURE 11/T.121
+
+Example public session protocol initiation sequence case 1: session member
+
+![Sequence diagram for Example public session protocol initiation sequence case 2: session creator. The diagram shows interactions between Local APE, Local GCC Provider, Local MCS Provider, Remote MCS Provider(s), Remote GCC Provider(s), and Remote APE(s). The sequence includes steps for user ID assignment, channel assignment, enrollment, and registration, with conditional paths for additional channels, tokens, and parameters.](69b7bd65e85cdef6fdd7fb0a8194257c_img.jpg)
+
+The diagram illustrates the sequence of operations for a public session protocol initiation sequence case 2: session creator. The participants involved are Local APE, Local GCC Provider, Local MCS Provider, Remote MCS Provider(s), Remote GCC Provider(s), and Remote APE(s). The operations are as follows:
+
+- Local APE** sends **GCC-Application-Permission-To-Enroll.ind** to **Local GCC Provider**.
+- Local GCC Provider** sends **MCS-ATTACH-USER.req** to **Local MCS Provider**.
+- Local MCS Provider** sends **MCS-ATTACH-USER.con** to **Local APE**.
+- Local APE** sends **[APE User ID = unique new] MCS-CHANNEL-JOIN.req** to **Local MCS Provider**.
+- Local MCS Provider** sends **[Channel ID = APE User ID] MCS-CHANNEL-JOIN.con** to **Local APE**.
+- Local APE** sends **[Channel ID = 0] MCS-CHANNEL-JOIN.req** to **Local MCS Provider**.
+- Local MCS Provider** sends **[Session Identifier Channel ID = unique new] MCS-CHANNEL-JOIN.con** to **Local APE**.
+- Local APE** sends **GCC-Application-Enroll.req** to **Local GCC Provider**.
+- Local GCC Provider** sends **[Inactive, with Session ID] GCC-Application-Enroll.con** to **Local APE**.
+- Local APE** sends **GCC-Application-Roster-Report.ind** to **Local GCC Provider**.
+- Local GCC Provider** sends **GCC-Application-Roster-Report.ind** to **Remote APE(s)**.
+- Local APE** sends **1 MCS-CHANNEL-JOIN.req** to **Local MCS Provider**.
+- Local MCS Provider** sends **[Channel ID = 0] MCS-CHANNEL-JOIN.con** to **Local APE**.
+- Local APE** sends **2 [Channel ID = unique new] MCS-CHANNEL-JOIN.req** to **Local MCS Provider**.
+- Local MCS Provider** sends **3 GCC-Registry-Register-Channel.req** to **Local GCC Provider**.
+- Local GCC Provider** sends **4 GCC-Registry-Register-Channel.con** to **Local APE**.
+- Local APE** sends **5 GCC-Registry-Assign-Token.req** to **Local GCC Provider**.
+- Local GCC Provider** sends **6 GCC-Registry-Assign-Token.con** to **Local APE**.
+- Local APE** sends **7 GCC-Registry-Set-Parameter.req** to **Local GCC Provider**.
+- Local GCC Provider** sends **8 GCC-Registry-Set-Parameter.con** to **Local APE**.
+- Local APE** sends **GCC-Registry-Allocate-Handle.req** to **Local GCC Provider**.
+- Local GCC Provider** sends **GCC-Registry-Allocate-Handle.con** to **Local APE**.
+- Local APE** sends **GCC-Application-Enroll.req** to **Local GCC Provider**.
+- Local GCC Provider** sends **[Active, with Session ID] GCC-Application-Enroll.con** to **Local APE**.
+- Local APE** sends **GCC-Application-Roster-Report.ind** to **Local GCC Provider**.
+- Local GCC Provider** sends **GCC-Application-Roster-Report.ind** to **Remote APE(s)**.
+
+Conditional paths are indicated by arrows pointing to the text "Conditional" from the MCS-CHANNEL-JOIN.req/con and GCC-Registry-Assign-Token.req/con messages.
+
+Operations are grouped by horizontal lines on the right side of the diagram:
+
+- Obtain User ID for the APE
+- Assign and join session identifier channel
+- Enroll Inactive in New Session
+- Assign, join and register any additional channel required by the protocol
+- Assign any token required by the protocol
+- Assign/identify any parameter specified by protocol
+- Allocate handle(s) if required by protocol
+- Enroll active in new session
+
+T0825420-96/d12
+
+Sequence diagram for Example public session protocol initiation sequence case 2: session creator. The diagram shows interactions between Local APE, Local GCC Provider, Local MCS Provider, Remote MCS Provider(s), Remote GCC Provider(s), and Remote APE(s). The sequence includes steps for user ID assignment, channel assignment, enrollment, and registration, with conditional paths for additional channels, tokens, and parameters.
+
+FIGURE 12/T.121
+
+Example public session protocol initiation sequence case 2: session creator
+
+### 6.2.5 Private session
+
+After joining its User ID Channel, the ARM shall examine the sessionID parameter to determine, if it is present, to participate in an existing private session (as a private member) or, if it is omitted, to create a new session (as a private convenor). See Figure 13.
+
+If the sessionID parameter is present, the ARM shall enroll Inactive in the session indicated by issuing a GCC-Application-Enroll request with the Active/Inactive flag set to Inactive and specifying the Session Key with the requisite Session ID. The ARM shall then wait until it has received an MCS-Channel-Admit indication from the peer ARM at the node convening the private session. It then attempts to join the channel indicated in this primitive by issuing an MCS-Channel-Join request and notifies the corresponding ASE if the channel join succeeded. The Channel ID is used as the session ID.
+
+If the application protocol requires multiple channels to be joined before an APE can be considered to be an active participant in a session, then the ARM shall wait to be admitted to those channels and then join them accordingly. Further channels may be joined as required when the application session is in progress. Likewise, if an application protocol mandates that an APE must know the identity of tokens or registry parameters before interacting with its peers, the ARM may determine their identity via the GCC Registry.
+
+The ARM shall then enroll Active by issuing a GCC-Application-Enroll request with the parameters specified in Table 3.
+
+If the sessionID parameter is omitted, the ARM shall attempt to create a new private session. The private convenor ARM shall first convene a private channel by issuing an MCS-Channel-Convene request. If successful, the returned MCS-Channel-Convene confirm contains the ID of the channel allocated. The channel ID also becomes the Session ID. The ARM shall then join this channel by issuing an MCS-Channel-Join request. The ARM shall then enroll Inactive in the session by issuing a GCC-Application-Enroll request with the parameters specified in Table 3.
+
+The onus of acquiring the set of resources that needs to be identified as part of the enrollment process for a private session rests with the ARM that created the session. If any additional channels, registry parameters or tokens are mandated by the protocol specification, the ARM should create these and register them with GCC as necessary. The Registry Key used to register these resources shall include the Session ID as part of the Session Key. Observe that it may not be necessary to register private channels to allow members of a private session to determine the function of each channel. This information may be conveyed more efficiently if an application protocol mandates the order in which the convenor issues MCS-Channel-Admit request primitives to session members. Registering of private channels is not precluded, however.
+
+Once all resources have been successfully assigned, the ARM shall enroll Active in the session by issuing a GCC-Application-Enroll request with the parameters specified in Table 3.
+
+The ARM shall then attempt to invite other nodes to participate in the private session by issuing a GCC-Application-Invoke request, specifying a list of GCC Node IDs to be invited or NULL (indicating that all nodes in the conference are to be invited) as the destination Nodes parameter. It shall also specify Dynamic Private as the Start-Up Channel in the Application Protocol entry.
+
+The convening ARM must then wait until it has received a GCC-Application-Roster-Report indication containing the MCS User IDs of the APEs to be invited to the private session. It should be anticipated that an APE may not be activated at one or more of the invited nodes. The ARM shall then issue an MCS-Channel-Admit request for the start-up channel, specifying the MCS-User IDs of the APEs to be invited as the list of MCS User IDs. The list of invitees is provided by the user application. This process is then repeated for any additional channels specified by the protocol.
+
+![Sequence diagram showing the initiation of a private session protocol. It involves message exchanges like GCC-Application-Permission, MCS-ATTACH-USER, MCS-CHANNEL-CONVENE, MCS-CHANNEL-JOIN, GCC-Application-Enroll, and GCC-Application-Roster-Report between a Convenor APE and Member APEs through Local and Remote GCC/MCS Providers. Steps include obtaining User IDs, convening and joining session identifier channels, enrolling in sessions, and assigning tokens/parameters. The diagram includes conditional branches and loops for additional channels, tokens, and parameters.](c494cd874a082a97b50b3c4d3938f467_img.jpg)
+
+**FIGURE 13/T.121**
+
+**Example private session protocol initiation sequence**
+
+Convenor  
+APE
+
+Local  
+GCC  
+Provider
+
+Local  
+MCS  
+Provider
+
+Remote  
+MCS  
+Provider(s)
+
+Remote  
+GCC  
+Provider(s)
+
+Member  
+APE(s)
+
+Operation
+
+<sup>a)</sup> GCC-Application-Invoke.ind is sent to the Node Controller.
+
+**Recommendation T.121 (07/96)**
+
+**25**
+
+T0825430-96/d13
+
+Sequence diagram showing the initiation of a private session protocol. It involves message exchanges like GCC-Application-Permission, MCS-ATTACH-USER, MCS-CHANNEL-CONVENE, MCS-CHANNEL-JOIN, GCC-Application-Enroll, and GCC-Application-Roster-Report between a Convenor APE and Member APEs through Local and Remote GCC/MCS Providers. Steps include obtaining User IDs, convening and joining session identifier channels, enrolling in sessions, and assigning tokens/parameters. The diagram includes conditional branches and loops for additional channels, tokens, and parameters.
+
+## 6.3 Forming registry keys
+
+To determine the identity of a dynamic token or channel via the GCC Registry, an ARM must form a registry key which consists of the Session Key for the current session and a Resource ID. A Resource ID is an ASN.1 OCTET STRING which describes the specific channel or token whose ID is required. The construction of Resource IDs for channels and tokens shall be defined in the application protocol specification.
+
+## 6.4 Capability negotiation
+
+APEs use the application enrollment mechanism for capabilities negotiation. The Application Capabilities List parameter of the GCC-Application-Enroll request primitive is used to specify the list of capabilities supported by the local APE.
+
+The Application Capabilities List included in the GCC-Application-Enroll request is composed of a list of capabilities to be advertised as supported by the APE. The result of the capabilities negotiation procedure is made apparent to the ARM by the receipt of a GCC-Application-Roster-Report indication from the GCC provider. The application roster report includes the Application Roster for peer APEs within the indicated conference – that is, APEs which have designated the same Session Key. The Application Roster includes a list of nodes for which a peer APE has enrolled. For each node, the list contains the GCC User ID of that node, and the Application User ID of the peer APE at that node. The Application Roster also includes an instance number, a flag indicating whether new nodes have been added since the last instance, a flag indicating whether nodes have been removed since the last instance, a flag indicating whether the Application Capabilities List has been updated since the last instance, and if so, the new Application Capabilities List. In the case of a newly enrolling APE, the Application Capabilities List is always updated since previous instances of the list are not available to this APE.
+
+When first enrolling, an ARM shall ignore received GCC-Application-Roster-Report indications in which the APE is not included (i.e. there is no entry in the Application Roster which has the GCC User ID of the local node and the Application Protocol Entity ID of the local APE as indicated in the GCC-Application-Enroll confirm). Once a roster is received which includes the local APE, that APE is now considered part of the conference and may proceed examining the roster to determine how to proceed.
+
+The Application Capabilities List received as part of the GCC-Application-Roster-Report indication corresponds to the collapsed Application Capabilities Lists of all enrolled peer APEs. That is, the list includes an entry for each capability which has been issued by any peer APE. For each entry, it includes the Capability ID, the number of peer APEs (including the local one) which had advertised this capability as part of their enroll procedure, and, in the case of capabilities of the MIN or MAX class, the minimum or maximum value of the parameter among all peer APEs which advertised this capability. For each capability, the rules used to determine the result of the capability exchange are specified by the application protocol.
+
+At any time whilst an APE is enrolled in a conference, the APE may receive additional GCC-Application-Roster-Report indications from the GCC provider indicating that the contents of the roster have changed. This may be due to new peer APEs enrolling in the conference, peer APEs leaving the conference, or peer APEs having modified their enrollment information.
+
+If, at any time, the local APE desires to indicate a change in its Application Capabilities List, it may re-enroll. This is done by re-issuing a GCC-Application-Enroll request to the GCC provider with the Enroll/Un-enroll flag set to Enroll and the updated Application Capabilities List, as well as the other parameters normally included in the enroll request. The result of this is potentially a change to the Application Roster, resulting in receipt of a GCC-Application-Roster-Report indication by the local APE as well as all other peer APEs in the conference.
+
+## 6.5 Leaving a session
+
+A user application wishing to leave a session shall signal this to the ARM. Before un-enrolling from the session, the ARM is responsible for deleting any GCC Registry entries it may have created, subject to them being no longer required by the rest of the participants in the session. The method of determining this is specified by the application protocol. The ARM leaves the session by issuing a GCC-Application-Enroll request with the Enroll/Un-enroll flag set to Un-enroll. No other parameters are required.
+
+If, at any time, the ARM receives a GCC-Application-Roster-Report indication in which it is no longer included (i.e. its Entity ID is absent), the ARM shall issue an MCS-Detach-User request immediately to detach from the specified conference. The APE is no longer considered to be enrolled in the conference at this time but may attempt to re-enroll in the conference by repeating the steps of its initialization.
+
+If, at any time, the ARM receives a GCC-Application-Permission-To-Enroll indication with the Grant/Revoke flag set to Revoke, it shall issue an MCS-Detach-User request immediately to detach from the specified conference. The APE is no longer considered to be enrolled in the conference at this time and shall not attempt to re-enroll.
+
+If the ARM is a member of a private session and it receives a GCC-Application-Roster-Report indication for that session in which the session creator is no longer included (i.e. its entity id is absent), the session is considered to have ceased to exist. The ARM shall immediately issue a GCC-Application-Enroll request with the Enroll/Un-enroll flag set to Un-enroll to detach from the specified session. No other parameters are required.
+
+# **7 Review of MCS resources and GCC services**
+
+This clause provides a review of the use of MCS resources (channels and tokens) and the GCC Registry. A fuller treatment of these topics is given in Recommendations T.122, T.125 and T.124. Note that whilst the onus of obtaining the initial set of resources for a session rests with the session creator, any session member may acquire additional resources at any time, if so permitted in the protocol specification.
+
+Application Service Elements (ASEs) should be designed such that, as far as possible, their operation is independent of the type of resource (i.e. static or dynamic) available to the session.
+
+## **7.1 Channels**
+
+MCS channels are used for the distribution of data within a conference. MCS Channels are divided into two types *static* and *dynamic*, the latter type having three variants, viz User ID Channel, Assigned Channel and Private Channel (see 8.4/T.122). An ARM subscribes to and leaves channels required by its user application by using the *channel join* and *channel leave* services respectively.
+
+### **7.1.1 Static channel**
+
+A channel with MCS Channel ID in the range 1-1000. Static channels are reserved for use by standardized application protocols such as T.126 and T.127. Static channels are assigned to their respective protocols in Recommendation T.120; each static channel has a specified purpose as described in the corresponding application protocol Recommendation. A standardized application protocol may use one or more static channels. For each standardized application protocol, one of the channels shall be designated as the *start-up* channel; this is the channel whose MCS Channel ID is used as the Session ID for the standard base session of that protocol.
+
+Static channels may only be used in the standard base session of the corresponding standardized application protocol. They are typically joined by all APEs participating in such a session and are thus used for broadcasting data to the session.
+
+The ARM shall examine the Resource List parameter to determine whether it needs to join any static channels. For each static channel identified in the Resource List the ARM shall issue an MCS-Channel-Join request, specifying the appropriate Channel ID. If this is successful, the ARM shall pass the Channel ID to its ASE.
+
+### **7.1.2 Dynamic channel**
+
+A channel with MCS Channel ID in the range 1001-65535. Dynamic channels form a pool of channel resources available to all sessions within a conference. The function of a dynamic channel is not predefined, but is determined by an APE when it issues a request for a dynamic channel. There are three variants of dynamic channel: User ID Channel, Assigned Channel and Private Channel.
+
+### 7.1.3 User ID channel
+
+An MCS Channel joined by a single APE. An MCS User ID Channel uniquely identifies an APE and may be used for sending data exclusively to that APE. A User ID is required when an APE undertakes to enroll Active. To acquire a unique User ID, the ARM shall issue an MCS-Attach-User request to the MCS provider, using the Conference ID contained in the GCC-Application-Permission-to-Enroll indication as the Domain Selector. On receipt of a successful MCS-Attach-User confirm in response, the ARM shall join the User ID channel indicated by issuing an MCS-Channel-Join request. See Figure 14.
+
+![Sequence diagram showing the process of obtaining an MCS User ID channel. The diagram involves Local APE, Local GCC Provider, Local MCS Provider, Remote MCS Provider(s), Remote GCC Provider(s), and Remote APE(s). The Local APE sends MCS-ATTACH-USER.req to the Local MCS Provider. The Local MCS Provider sends MCS-ATTACH-USER.con back to the Local APE. The Local APE then sends MCS-CHANNEL-JOIN.req to the Local MCS Provider. The Local MCS Provider sends MCS-CHANNEL-JOIN.con back to the Local APE. The Local APE also sends [APE User ID = unique new] to the Local GCC Provider. The Local GCC Provider sends [Channel ID = APE User ID] to the Local MCS Provider. The Local MCS Provider then sends the request to the Remote MCS Provider(s). The Remote MCS Provider(s) sends the response to the Remote GCC Provider(s). The Remote GCC Provider(s) sends the response to the Remote APE(s). The Remote APE(s) then performs the operation 'Obtain User ID for APE' and 'Join User ID Channel'.](cfb98c691c1af5befe32ff9442eea511_img.jpg)
+
+```
+
+sequenceDiagram
+    participant LA as Local APE
+    participant LGP as Local GCC Provider
+    participant LMP as Local MCS Provider
+    participant RMP as Remote MCS Provider(s)
+    participant RGP as Remote GCC Provider(s)
+    participant RAP as Remote APE(s)
+
+    LA->>LMP: MCS-ATTACH-USER.req
+    LMP-->>LA: MCS-ATTACH-USER.con
+    LA->>LGP: [APE User ID = unique new]
+    LGP->>LMP: [Channel ID = APE User ID]
+    LMP->>RMP: MCS-CHANNEL-JOIN.req
+    RMP-->>RGP: MCS-CHANNEL-JOIN.con
+    RGP-->>RAP: MCS-CHANNEL-JOIN.con
+    RAP->>RAP: Obtain User ID for APE
+    RAP->>RAP: Join User ID Channel
+  
+```
+
+T0825440-96/d14
+
+Sequence diagram showing the process of obtaining an MCS User ID channel. The diagram involves Local APE, Local GCC Provider, Local MCS Provider, Remote MCS Provider(s), Remote GCC Provider(s), and Remote APE(s). The Local APE sends MCS-ATTACH-USER.req to the Local MCS Provider. The Local MCS Provider sends MCS-ATTACH-USER.con back to the Local APE. The Local APE then sends MCS-CHANNEL-JOIN.req to the Local MCS Provider. The Local MCS Provider sends MCS-CHANNEL-JOIN.con back to the Local APE. The Local APE also sends [APE User ID = unique new] to the Local GCC Provider. The Local GCC Provider sends [Channel ID = APE User ID] to the Local MCS Provider. The Local MCS Provider then sends the request to the Remote MCS Provider(s). The Remote MCS Provider(s) sends the response to the Remote GCC Provider(s). The Remote GCC Provider(s) sends the response to the Remote APE(s). The Remote APE(s) then performs the operation 'Obtain User ID for APE' and 'Join User ID Channel'.
+
+FIGURE 14/T.121
+
+#### Obtaining an MCS User ID channel
+
+### 7.1.4 Assigned Channel
+
+An MCS Channel which may be used for broadcasting of data to all participants within a session. Access to these channels is unregulated, i.e. any APE may join or leave an assigned channel at any time. If all APEs leave an assigned channel, it ceases to exist and its Channel ID may be re-assigned to a different use; this is a potential pitfall. See Figure 15.
+
+Assigned channels may be used in either standard base, non-standard base or public sessions. Use in private sessions is not recommended since any APE can join an assigned channel if it is aware of the channel's existence.
+
+The start-up channel of a public or non-standard base session is an assigned channel.
+
+If additional assigned channels are required after a session has been established, then the ARM shall first attempt to create a new assigned channel by issuing an MCS-Channel-Join request primitive with Channel ID = 0. The returned MCS-Channel-Join confirm, if successful, contains the assigned Channel ID which is to be used as the assigned channel. The ARM may then attempt to register assigned this channel by issuing a GCC-Registry-Register-Channel request with the parameters given in Table 4. On receipt of the corresponding GCC-Registry-Register-Channel confirm, the ARM shall examine the Result parameter. If this is "successful" the ARM shall notify its ASE of the Channel ID assigned to the assigned channel. A Result of "index already exists" indicates that another ARM has already registered an assigned channel with the same Registry Key. In this case the ARM shall leave the channel it had previously created by issuing an MCS-Channel-Leave request. It shall then attempt to join the assigned channel registered by the other ARM by issuing an MCS-Channel-Join request, specifying the Channel ID returned in the Registry Item parameter of the GCC-Registry-Register-Channel confirm as Channel ID. If this succeeds, the ARM shall pass the Resource ID and corresponding Channel ID to its ASE. If the attempt fails, and the result is "no such channel", the ARM may re-attempt the channel creation process. In all other cases, the ARM should indicate to the ASE that it was unable to assign a channel. See also Table 5.
+
+![Sequence diagram showing the process of creating and registering an assigned channel between Local APE, Local GCC Provider, Local MCS Provider, Remote MCS Provider(s), Remote GCC Provider(s), and Remote APE(s).](f9c64800d9bace9b4315646d1057be3c_img.jpg)
+
+The diagram illustrates the sequence of operations for creating and registering an assigned channel across six entities: Local APE, Local GCC Provider, Local MCS Provider, Remote MCS Provider(s), Remote GCC Provider(s), and Remote APE(s). The process is divided into two main phases: initial channel creation and a fallback registration process.
+
+**Initial Channel Creation (Steps 1-4):**
+
+- Step 1:** Local APE sends `MCS-CHANNEL-JOIN.req` to Local MCS Provider with `[Channel ID = 0]`.
+- Step 2:** Local MCS Provider responds with `MCS-CHANNEL-JOIN.con`. Local APE creates an assigned channel.
+- Step 3:** Local APE sends `GCC-Registry-Register-Channel.req` to Local GCC Provider.
+- Step 4:** Local GCC Provider responds with `GCC-Registry-Register-Channel.con`. Local APE attempts to register the assigned channel.
+
+**Fallback Registration Process (Steps 5-8):**
+
+- Step 5:** Local APE sends `MCS-CHANNEL-LEAVE.req` to Local MCS Provider with `[Assigned Channel ID]`. Local APE leaves the assigned channel if registration fails.
+- Step 6:** Local MCS Provider responds with `MCS-CHANNEL-LEAVE.con`.
+- Step 7:** Local APE sends `MCS-CHANNEL-JOIN.req` to Local MCS Provider with `[Channel ID = GCC-Registry-Register-Channel.con Registry Item]`. Local APE joins the previously registered assigned channel if registration fails.
+- Step 8:** Local MCS Provider responds with `MCS-CHANNEL-JOIN.con`.
+
+**Remote Process (Steps 9-12):**
+
+- Step 9:** Remote APE(s) sends `GCC-Registry-Retrieve-Entry.req` to Remote GCC Provider(s).
+- Step 10:** Remote GCC Provider(s) responds with `GCC-Registry-Retrieve-Entry.con`. Remote APE identifies the assigned channel ID.
+- Step 11:** Remote APE(s) sends `MCS-CHANNEL-JOIN.req` to Remote MCS Provider(s) with `[Channel ID = GCC-Registry-Retrieve-Entry.con Registry Item]`. Remote APE joins the assigned channel.
+- Step 12:** Remote MCS Provider(s) responds with `MCS-CHANNEL-JOIN.con`.
+
+**Annotations:**
+
+- A bracket groups steps 5-8, with a note: "Execute if channel registered (Step 4 fails)".
+- Another bracket groups steps 9-12, with a note: "Execute if channel registered (Step 4 fails)".
+
+T0825450-96/d15
+
+Sequence diagram showing the process of creating and registering an assigned channel between Local APE, Local GCC Provider, Local MCS Provider, Remote MCS Provider(s), Remote GCC Provider(s), and Remote APE(s).
+
+FIGURE 15/T.121  
+Creating and registering an assigned channel
+
+TABLE 4/T.121  
+Parameters for GCC-Registry-Register-Channel Request
+
+| Parameter     | Contents                                                    |
+|---------------|-------------------------------------------------------------|
+| Conference ID | Provided by GCC-Application-Permission-To-Enroll indication |
+| Registry Key  | Registry Key formed as described in 6.3                     |
+| Channel ID    | Channel ID returned in MCS-Channel-Join confirm             |
+
+TABLE 5/T.121  
+Parameters for GCC-Registry-Retrieve-Entry Request
+
+| Parameter     | Contents                                                    |
+|---------------|-------------------------------------------------------------|
+| Conference ID | Provided by GCC-Application-Permission-To-Enroll indication |
+| Registry Key  | Registry Key formed as described in 6.3                     |
+
+### 7.1.5 Private channel
+
+A private channel is an MCS Channel with an authorized group of users. It may be used for distribution of data to a selected subset of participants within a session. Access to a private channel is controlled by the APE that convened the channel. This APE is termed the Channel Manager and has the following privileges:
+
+- Privilege to admit other APEs to the private channel.
+- Privilege to expel other APEs from the private channel.
+- Privilege to disband the private channel.
+
+Private channels may be used in standard base, non-standard base, public or private sessions.
+
+The start-up channel of a private session is a private channel.
+
+If the convening user application wishes to remove one or more APEs from membership of the private channel, the Convenor ARM shall issue an MCS-Channel-Expel request, specifying the MCS-User IDs of the ASEs to be expelled as the list of MCS User IDs.
+
+Once the user application at the convening node indicates that it has no further use for the private channel, the Convenor ARM shall disband the channel by issuing an MCS-Channel-Disband request, specifying the private channel as Channel ID. All ARMs currently joined to the private channel then receive an MCS-Channel-Expel indication notifying them that the private channel is no longer available for use.
+
+If additional private channels are required after a session has been established, then the ARM shall follow the procedure described for the convenor or member as appropriate. See Figure 16.
+
+### 7.1.6 Potential problems with the use of MCS channels
+
+- i) MCS does not provide any indication to the members of a channel when an APE joins or leaves a channel. This is a particular problem in the use of private channels, since the private channel manager has no confirmation of whether the invited APEs have joined the private channel. A possible workaround (as implemented in Recommendation T.127) is for APEs to confirm that they have joined the private channel by sending a PDU to the Channel Manager's User ID Channel.
+- ii) Caution is recommended in the use of assigned channels, since such channels cease to exist when all joined users leave. No indication is provided when this occurs. Since MCS can reuse dynamic channels, an APE should not attempt to use an assigned channel unless it is certain of its existence and current use. The presence of an entry in the GCC Application Registry for an assigned channel does not guarantee that the channel exists or that the use indicated by the Registry is still valid.
+- iii) Data in transit on a private channel when the channel manager leaves, disbands or expels members from the channel may not reach its intended destinations since MCS may expel channel members before such data is delivered. Use of the MCS token inhibit service allows channel members to signal completion of a transaction to the channel manager, thus enabling the channel manager to avoid inadvertent data loss through premature expulsion of channel members. Each channel member is required to inhibit a designated token before the transaction may begin and must release that token on completion of the transaction. Application protocols must ensure that all channel members have inhibited the relevant token before the transaction starts. Alternatively, application protocols may define a PDU exchange between channel manager and channel members which ensures that all data is delivered before a private channel is disbanded.
+- iv) Data in transit on any channel may not reach its intended destinations if the sending APE detaches before such data is delivered. The sending APE may avoid this by using the remedy described in iii).
+
+![Sequence diagram showing the management of a private channel between Local APE, Local GCC Provider, Local MCS Provider, Remote MCS Provider(s), Remote GCC Provider(s), and Remote APE(s). The diagram includes messages for channel convening, joining, registering, admitting, expelling, and disbanding, with corresponding operations on the right.](f57c7b37d7a05a99618104f390089f03_img.jpg)
+
+```
+
+sequenceDiagram
+    participant LocalAPE as Local APE
+    participant LocalGCC as Local GCC Provider
+    participant LocalMCS as Local MCS Provider
+    participant RemoteMCS as Remote MCS Provider(s)
+    participant RemoteGCC as Remote GCC Provider(s)
+    participant RemoteAPE as Remote APE(s)
+
+    LocalAPE->>LocalMCS: MCS-CHANNEL-CONVENE.req
+    LocalMCS->>LocalAPE: MCS-CHANNEL-CONVENE.con
+    LocalAPE->>LocalMCS: [Private Channel ID = unique new] MCS-CHANNEL-JOIN.req
+    LocalMCS->>LocalAPE: [Channel ID = Private Channel ID] MCS-CHANNEL-JOIN.con
+    LocalAPE->>LocalGCC: GCC-Registry-Register-Channel.req
+    LocalGCC->>LocalAPE: GCC-Registry-Register-Channel.con
+    LocalAPE->>LocalMCS: MCS-CHANNEL-ADMITreq [MCS User ID(s)]
+    LocalMCS->>RemoteMCS: MCS-CHANNEL-ADMITind [Channel ID]
+    RemoteMCS->>RemoteAPE: MCS-CHANNEL-JOIN.req
+    RemoteAPE->>RemoteMCS: MCS-CHANNEL-JOIN.con
+    RemoteMCS->>RemoteGCC: GCC-Registry-Retrieve-Entry.req
+    RemoteGCC->>RemoteMCS: GCC-Registry-Retrieve-Entry.con
+    LocalAPE->>LocalMCS: MCS-CHANNEL-EXPEL.req [MCS User ID(s)]
+    LocalMCS->>RemoteMCS: MCS-CHANNEL-EXPEL.ind [Channel ID]
+    RemoteMCS->>RemoteAPE: MCS-CHANNEL-EXPEL.ind [Channel ID]
+    LocalAPE->>LocalMCS: MCS-CHANNEL-DISBAND.req [Channel ID = Private Channel ID]
+    LocalMCS->>RemoteMCS: MCS-CHANNEL-EXPEL.ind [Channel ID]
+    RemoteMCS->>RemoteAPE: MCS-CHANNEL-EXPEL.ind [Channel ID]
+  
+```
+
+Operations:
+
+- Local APE convenes private channel
+- Convenor joins private channel (optional)
+- Convenor registers private channel (optional)
+- Convenor admits other APEs to private channel
+- Members join private channel
+- Members identify private channel (optional)
+- Convenor expels APEs from private channel (optional)
+- Convenor disbands private channel
+
+T0825460-96/d16
+
+Sequence diagram showing the management of a private channel between Local APE, Local GCC Provider, Local MCS Provider, Remote MCS Provider(s), Remote GCC Provider(s), and Remote APE(s). The diagram includes messages for channel convening, joining, registering, admitting, expelling, and disbanding, with corresponding operations on the right.
+
+FIGURE 16/T.121  
+Management of private channel
+
+### 7.1.7 Summary
+
+Static channels are used by the standard base session of standardized application protocols for broadcasting data.
+
+A User ID Channel is required by each active APE. It may be used for sending data exclusively to that APE.
+
+Assigned Channels are used within any session for broadcasting of data.
+
+Private Channels are used within a private session for broadcasting of data. They may also be used within any session for selective distribution of data.
+
+The choice of channels available to non-standard application protocols for general use is between assigned and private. This subclause compares the merits of each in order to assist the application protocol developer to make the appropriate choice. See Table 6.
+
+#### *Private*
+
+- Known lifetime, determined by channel manager.
+- Regulated access.
+- Ceases to exist if channel manager leaves session.
+
+#### Assigned
+
+- Unknown lifetime.
+- Unregulated access.
+- Can persist after the creator has left the session.
+
+TABLE 6/T.121
+
+#### Use of MCS channels
+
+| Channel type                                                                                | Session Type  |                   |        |                 |
+|---------------------------------------------------------------------------------------------|---------------|-------------------|--------|-----------------|
+|                                                                                             | Standard base | Non-standard base | Public | Private         |
+| Static                                                                                      | ✓             | 7                 | 7      | 7               |
+| User ID                                                                                     | ✓             | ✓                 | ✓      | ✓               |
+| Assigned                                                                                    | ✓             | ✓                 | ✓      | ● <sup>ns</sup> |
+| Private                                                                                     | ✓             | ✓                 | ✓      | ✓               |
+| <div>✓ Permitted</div> <div>7 Not Permitted</div> <div>●<sup>ns</sup> Not Recommended</div> |               |                   |        |                 |
+
+## 7.2 Data transfer
+
+There are two mechanisms available for distributing data, viz *Send Data* and *Uniform Send Data*. Both techniques transfer data to all APEs joined to an MCS channel.
+
+Send Data provides delivery of data to each APE joined to an MCS Channel by the shortest possible route, thus minimizing network traffic and latency. The ordering of data received at each APE may differ and the sender of the data does not receive a copy of the data.
+
+Uniform Send Data provides sequenced delivery of data, i.e. it guarantees that each APE joined to an MCS Channel receives data in the same order. The sender of the data receives a copy of the data if the sender is joined to that channel.
+
+An APE must join an MCS Channel in order to *receive* data on that channel. An APE may *send* data to any MCS channel, irrespective of whether it is joined to that channel, with the exception of Private Channels where an APE must be admitted to the channel before it attempts to send data to the channel.
+
+## 7.3 Tokens
+
+Tokens provide a means to implement exclusive access to resources within a conference. For example, to prevent conflicting commands being issued to a device (such as a camera) by different users, it is desirable to restrict access to that device to a single user at any given instance. This can be achieved by associating a token with the device and mandating in the corresponding application protocol that only the current token holder is permitted to issue control commands to that device.
+
+Manipulation of tokens is supported by a number of MCS services:
+
+The *token grab* service allows one user to exclusively hold a specified token. Users may use the *token test* service to determine the status of a token at any time and may request the token from the holder with the *token please* service. The token holder may transfer control of a token to another specified user with the *token give* service or return a token to a generally available status with the *token release* service. The token please and token give services allow a token to be transferred between two users without the possibility of it being grabbed by a third user.
+
+Tokens may also be used for event coordination between multiple users via the *token inhibit* service. Users can independently inhibit and release the same token. For example, if it was desired to know when all users have completed reception and processing of a bulk file transfer, all users would inhibit the same token at the start of the operation and each individual user would release the token when it had completed the process. To avoid race conditions, it is necessary to ensure that all users have inhibited the token before testing whether the token has become uninhibited. Any user could test the token at will to determine if the token is free which means all users have completed processing.
+
+Tokens may be either static or dynamic. MCS treats all tokens identically; the distinction between static and dynamic tokens is made within GCC which uses the Registry to assign dynamic tokens. All operations on tokens are performed by the ASE using the MCS token services.
+
+### 7.3.1 Static tokens
+
+A token with MCS Token ID in the range 1-16383. Static tokens are reserved for use by standardized application protocols such as T.126 and T.127. Static tokens are assigned to their respective protocols in Recommendation T.120; each static token has a specified purpose as described in the corresponding application protocol Recommendation. A standardized application protocol may use zero or more static tokens.
+
+Static tokens may only be used in the standard base session of the corresponding standardized application protocol.
+
+The ARM has no involvement in the use of static tokens.
+
+### 7.3.2 Dynamic tokens
+
+A token with MCS Token ID in the range 16384-65535. Dynamic tokens form a pool of token resources available to all sessions within a conference. The function of a dynamic token is not predefined, but is determined when it is assigned by GCC. Dynamic tokens may be used in any type of session. See Figure 17.
+
+The ARM shall examine the Resource List parameter to determine whether it needs to identify Token IDs for any dynamic tokens. The same method may be used regardless of whether the ARM is the session convenor or a session member. For each Token Resource ID specified in the Resource List, the ARM shall issue a GCC-Registry-Assign-Token request to the GCC provider using the parameters specified in Table 7. If the Result parameter returned in the GCC-Registry-Assign-Token confirm is “successful” or “index already exists” the Token ID contained in the Registry Item of the returned confirm primitive is used as the Token ID for the token corresponding to the Resource ID used in the Registry Key. The ARM shall pass the Resource ID and associated Token ID to its ASE.
+
+Observe that it is not necessary to use the GCC-Registry-Retrieve-Entry to identify tokens since GCC-Registry-Assign-Token returns the Token ID irrespective of whether the token existed before the request was made.
+
+Additional dynamic tokens required during a session may be assigned by any participant in that session, subject to any constraints defined by the relevant application protocol specification.
+
+![Sequence diagram showing the process of assigning and identifying dynamic tokens between Local APE, Local GCC Provider, Local MCS Provider, Remote MCS Provider(s), Remote GCC Provider(s), and Remote APE(s).](67114ecf6da13c97a89aeff0d86885d5_img.jpg)
+
+The diagram illustrates the sequence of operations for assigning and identifying dynamic tokens. It involves six participants: Local APE, Local GCC Provider, Local MCS Provider, Remote MCS Provider(s), Remote GCC Provider(s), and Remote APE(s). The operations are as follows:
+
+- Local APE** sends **GCC-Registry-Assign-Token.req** to **Local GCC Provider**.
+- Local GCC Provider** sends **GCC-Registry-Assign-Token.con** to **Local APE**.
+- Local APE** assigns token (Local APE assigns token).
+- Remote APE(s)** sends **GCC-Registry-Assign-Token.req** to **Remote GCC Provider(s)**.
+- Remote GCC Provider(s)** sends **GCC-Registry-Assign-Token.con** to **Remote APE(s)**.
+- Remote APE(s)** identifies token (Remote APE identifies token).
+
+T0825470-96/d17
+
+Sequence diagram showing the process of assigning and identifying dynamic tokens between Local APE, Local GCC Provider, Local MCS Provider, Remote MCS Provider(s), Remote GCC Provider(s), and Remote APE(s).
+
+FIGURE 17/T.121  
+Assigning and identifying dynamic tokens
+
+TABLE 7/T.121  
+Parameters for GCC-Registry-Assign-Token Request
+
+| Parameter     | Contents                                                    |
+|---------------|-------------------------------------------------------------|
+| Conference ID | Provided by GCC-Application-Permission-To-Enroll indication |
+| Registry Key  | Registry Key formed as described in 6.3                     |
+
+## 7.4 Application roster
+
+The ARM is responsible for monitoring GCC-Application-Roster report indications and notifying its ASE of any changes. The Application Roster Entry Report contains that portion of the roster corresponding to the application protocol session in which the APE is enrolled. In the case of an APE that has enrolled inactively without a Session ID, the Application Roster Report will contain that portion of the roster corresponding to all application sessions with the same application protocol key.
+
+At any time while an APE is enrolled in a conference, it may receive additional GCC-Application-Roster-Report indication, notifying it of a change in the roster contents. This may be due to new peer APEs enrolling in the conference, peer APEs leaving the conference, or peer APEs having modified their enrollment information.
+
+A user application may change its Application Capabilities List at any time by instructing the appropriate ARM to re-enroll. The ARM then issues a GCC-Application-Enroll request with the Enroll/Un-enroll flag set to Enroll, including the revised Application Capabilities List, and providing all other parameters as included in the initial active enrollment. This may result in a change to the collapsed capability set, in which case all APEs in the session will receive a GCC-Application-Roster-Report indication.
+
+The effect of any change in the collapsed capability set on any transactions occurring at the time of the change shall be specified by the respective application protocol.
+
+## 7.5 Application Registry
+
+The Application Registry is a centralized database maintained at the Top GCC Provider that may be used to allow APEs to independently determine the resources (such as dynamic channels and tokens) to be used for a specific application protocol session. The significance of the Registry contents is specified by individual application protocols.
+
+The Application Registry provides mechanisms to:
+
+- Register channels.
+- Assign tokens.
+- Assign globally unique handles, either individually or as a block of handles.
+- Establish common parameters for the session.
+- Change and delete registry entries.
+- Retrieve registry entries.
+- Monitor changes made to registry entries (including the deletion of entries).
+
+Each registry entry is identified by a unique key which identifies the application protocol session with which the entry is associated. The key also comprises a Resource ID, defined by the application protocol, to describe the use of the registry entry within that session.
+
+Each registry entry has a designated owner – the APE that created the entry. If the owner of an entry leaves the conference that entry becomes unowned. Owned entries may only be deleted by their respective owners; unowned entries may be deleted by any APE. Channel and token entries may not be modified. Owned parameter entries may be modified by their respective owners. Unowned parameter entries may be modified by any APE; this APE becomes the new owner of the entry. Registry entries persist for the lifetime of the session and care must be exercised by registry entry owners to ensure that registry entries are deleted when no longer required. This is particularly true in the case of the registration session where redundant entries are likely to persist indefinitely, unless explicitly deleted by the owner. Observe that in some cases it may be inappropriate or impossible for departing APEs to delete the entries they created.
+
+All communication between an APE and the Application Registry is performed by the ARM.
+
+## 7.6 Conductorship
+
+The ARM is responsible for notifying its ASE and user application when the conference enters or leaves conducted mode, and of any change in the conducting node. Other operations in conducted mode are performed directly by the user application or ASE.
+
+A user application shall issue requests for its local node to become the GCC conductor, transfer conductorship, or relinquish conductorship via its local Node Controller.
+
+The *session conductor* is an APE at the conducting node which has the Conducting Operation Flag set in the Application Roster for that session. The Node Controller at the conducting node proxies as session conductor in the absence of such an APE.
+
+If an APE adopts the role of session conductor, its ASE shall arbitrate requests from peer ASEs to act. Such requests and the associated responses shall be issued using PDUs specified by the application protocol. These may be used to assign different privileges to each ASE in the session.
+
+If a Node Controller becomes session conductor, it may only grant or refuse permission to act on a node by node basis. This gives much coarser control of ASEs. An ASE may request permission to act via its local Node Controller, which in turn issues a GCC-Conductor-Permission-Ask. If the conducting Node Controller issues a GCC-Conductor-Permission-Grant which includes the requesting node in the “List of Nodes Granted Permission” then all ASEs at that node may act.
+
+The detailed effect of conductorship is specified by each application protocol specification.
+
+## 7.7 Remote invoking
+
+A user application wishing to dynamically invoke a peer application at another node and invite it to join the application session shall do this via the ARM. The user application must provide the following information for each application protocol it wishes to use:
+
+- Session Key.
+- Start-up channel type (static, dynamic multicast, dynamic private or dynamic userid).
+- Minimum capability set.
+- List of nodes to be invited to the application session.
+
+The ARM then issues a GCC-Application-Invoke request, specifying a list of GCC Node Ids of the nodes to be invited, the start-up channel type, a list of application protocol sessions to enroll in and, for each application protocol, the expected (i.e. minimum) capability set.
+
+GCC-Application-Invoke indications are delivered to the Node Controller which is responsible for determining which APEs to activate.
+
+# 8 User application guidelines
+
+This clause provides guidelines on use of the T.120 infrastructure to ensure consistent and predictable application behaviour.
+
+## 8.1 Identification of user applications
+
+In certain circumstances it may be useful to be able to determine which nodes host a specific user application or the range of user applications available at a remote node. This may be required for both local and remote invocation of user applications. An APE may optionally choose to identify its user application by inclusion of a non-standard non-collapsing capability parameter in the GCC-Application-Enroll request. By consulting the Application Roster via its APE, a user application can thus detect the presence of a particular user application at other nodes. A Node Controller receiving a GCC-Application-Invoke indication may choose to consult the user application capability entries in the Application Roster for the appropriate session(s) to determine which user applications are active at other nodes before activating a user application locally. Note that a Node Controller will only be able to detect the presence of a given user application if it is aware of the non-collapsing capability parameter advertised by that application.
+
+Non-standard application protocol keys may only be used to advertise support of a non-standard application protocol. Enrolling with a non-standard application protocol key to advertise the presence of a specific user application is strongly discouraged as it would prevent interoperability with other user applications that employ the same application protocol for the same purpose.
+
+## 8.2 Use of collapsing and non-collapsing capabilities
+
+An APE may use the non-collapsing capabilities field in the GCC-Application-Enroll request to identify its user application and advertise its application protocol specific capabilities.
+
+Use of a non-collapsing capability parameter in the GCC-Application-Enroll request is appropriate if there is a need to identify *which particular* peer APEs support a given capability in order to guarantee interoperability. Alternatively, it may be used to advertise the availability of a resource to the conference (e.g. a camera available for remote control). If the APE only needs to determine the *number* of peer APEs that support a specific capability, then it should use a collapsing capability. In order to avoid making the Application Roster unnecessarily large, it is strongly recommended that the number of non-collapsing capabilities be kept to an absolute minimum.
+
+## 8.3 Session context
+
+If a conference has multiple concurrent sessions of a specific application protocol then there may be a need to distinguish those sessions so that users can select the most appropriate session in which to participate. Typically, a session would be used in a specific context which is determined by the participants of the session. For example, one T.126 whiteboard session may be used to present one topic, another could be used to present a second topic. The different contexts of these sessions allow them to be distinguished.
+
+A GCC Application Registry Parameter may optionally be used to describe the context of a specific application protocol session. A Resource ID (constructed by encoding the 7 characters of the word “CONTEXT” into successive octets according to Recommendation T.50) is reserved for this purpose. The content of the Registry Parameter is a user readable string which shall be encoded as an unrestricted BMPString using Packed Encoding Rules (Basic Aligned variant). The resulting encoded bit string is placed into the OCTET STRING in the order such that for each octet, the leading bit is placed in the most significant bit position, and the trailing bit is placed in the least significant bit position.
+
+## 8.4 Selecting a session to participate in
+
+If a user simply wishes to communicate with *any* node that supports *the same application protocol(s) for the same purpose* then the most appropriate session to use is the:
+
+- standard base session for standardized application protocols (see 8.3);
+- non-standard base session for non-standardized application protocols.
+
+The base sessions are intended for general purpose communication between all terminals that support a specific protocol (e.g. the T.127 standard base session would be used for general purpose file transfer).
+
+Note that an APE may be configured to enroll in a base session without user intervention, thus allowing user applications based on standard or non-standard protocols to be started automatically upon joining a conference.
+
+If there are multiple active sessions of a given application protocol present in a conference, a user may need to intervene. The user requires sufficient information to choose the most appropriate session(s) in which to participate, or to determine whether it is necessary to establish a new session.
+
+This decision may be based on one or more of the following criteria:
+
+- the session context (e.g. topic of discussion).
+- which nodes are participating in the session.
+- the negotiated capability set of the session.
+
+## 8.5 Controlling the use of a session
+
+The creator of a session may wish to impose constraints on a session to ensure that less capable APEs do not inadvertently enroll in the session and potentially degrade the capabilities of the session to a level which is considered unacceptable by the session creator. If a user wishes to impose a *minimum capability set* on a session, then a dynamic private session shall be used. The session creator specifies the requisite capability criteria in the GCC-Application-Invoke request.
+
+If a user wishes to indicate that a session is to be used in a *specific context*, then a dynamic session should be used and a session context (user readable text string) shall be provided in the GCC Application Registry for that session.
+
+## 8.6 Adding new participants to a session
+
+The GCC-Application-Invoke request primitive may be used by the convenor of a private session to invite additional nodes (e.g. late joiners) to that session at any time. Any participant in a standard base, non-standard base or public session may invite new nodes to that session at any time using GCC-Application-Invoke request. A Node Controller receiving a GCC-Application-Invoke indication may choose to ignore it if there is already an active APE at that node in the session identified.
+
+## 8.7 Extension, modification and reuse of application protocols
+
+Application protocols are tools which can be extended, modified or tailored to a specific use. In order to determine whether such changes result in a new distinct protocol or are merely an extension of the existing protocol, it is necessary to decide whether APEs conforming to the changed application protocol are intended to interwork with APEs conforming to the original application protocol. If interworking is intended, then the revised protocol can be considered to be an extension of the existing protocol, otherwise it is a new application protocol and must be assigned a unique application protocol key and resources.
+
+If an APE offers proprietary extensions to an application protocol, such *that it is intended to be able to interwork with APEs conforming to the original protocol*, then it shall enroll with the application protocol key of the original protocol and advertise its enhanced functionality using collapsing or non-collapsing capabilities, according to the guidelines specified in 8.2.
+
+Where an application protocol is to be used for a distinct purpose or is modified in such a way that *APEs conforming to the revised protocol are not intended to be able to interwork with APEs conforming to the original protocol*, then the revised protocol is considered to be a new application protocol and it must be assigned a unique application protocol key to differentiate it from the original protocol. Any static channels and tokens used by the original application protocol cannot be used by the revised protocol. These rules also apply if use of an application protocol is constrained in any manner. For example, APEs employing the methods (PDUs and procedures) of Recommendation T.127 exclusively for transfer of documents between word processor applications shall not enroll with the T.127 application key if they are not intended to be able to interwork with a general purpose file transfer APE, nor shall they use the static channels and tokens reserved for Recommendation T.127.
+
+Similarly, if a number of application protocols are required to collaborate to achieve certain functionality (e.g. a business card application protocol reusing the methods of Recommendations T.126 and T.127), then new application key(s) are required if the component APEs are only intended to interwork with other APEs collaborating for the same purpose.
+
+Where application protocols are being combined to achieve a specific function, the preferred approach is to define a single new application protocol which is an aggregation of the component protocols. This, in effect, creates a new APE by the merger of pre-existing APEs. It may be necessary to resolve conflicts in capability IDs and GCC Registry Resource IDs between the application protocols for the new APE.
+
+An alternative approach is to retain the pre-existing APEs as distinct components, each with a new application protocol key to distinguish it from the protocol from which it was derived. Observe, however, that in this case it is necessary to define a means to associate application protocol sessions which are cooperating to achieve a common purpose so that user applications can determine the correct combination of sessions for their APEs to enroll in. To avoid duplication of information, it is suggested that the list of associated sessions is maintained in the Application Registry for one of the sessions, to be termed the *root session*. It is up to the application protocol developer to determine which application protocol should serve as the root session; a suitable choice would be the application protocol whose functionality most closely matches the intended common purpose.
+
+# ITU-T RECOMMENDATIONS SERIES
+
+|                 |                                                                                                                |
+|-----------------|----------------------------------------------------------------------------------------------------------------|
+| Series A        | Organization of the work of the ITU-T                                                                          |
+| Series B        | Means of expression                                                                                            |
+| Series C        | General telecommunication statistics                                                                           |
+| Series D        | General tariff principles                                                                                      |
+| Series E        | Telephone network and ISDN                                                                                     |
+| Series F        | Non-telephone telecommunication services                                                                       |
+| Series G        | Transmission systems and media                                                                                 |
+| Series H        | Transmission of non-telephone signals                                                                          |
+| Series I        | Integrated services digital network                                                                            |
+| Series J        | Transmission of sound-programme and television signals                                                         |
+| Series K        | Protection against interference                                                                                |
+| Series L        | Construction, installation and protection of cables and other elements of outside plant                        |
+| Series M        | Maintenance: international transmission systems, telephone circuits, telegraphy, facsimile and leased circuits |
+| Series N        | Maintenance: international sound-programme and television transmission circuits                                |
+| Series O        | Specifications of measuring equipment                                                                          |
+| Series P        | Telephone transmission quality                                                                                 |
+| Series Q        | Switching and signalling                                                                                       |
+| Series R        | Telegraph transmission                                                                                         |
+| Series S        | Telegraph services terminal equipment                                                                          |
+| <b>Series T</b> | <b>Terminal equipments and protocols for telematic services</b>                                                |
+| Series U        | Telegraph switching                                                                                            |
+| Series V        | Data communication over the telephone network                                                                  |
+| Series X        | Data networks and open system communication                                                                    |
+| Series Z        | Programming languages                                                                                          |
\ No newline at end of file
diff --git a/marked/T/T-REC-T.122-199802-I_PDF-E/0a42e05c07941450f34e4f7117725834_img.jpg b/marked/T/T-REC-T.122-199802-I_PDF-E/0a42e05c07941450f34e4f7117725834_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..3530864eeae24dddccc1b337541237dff8ad8746
--- /dev/null
+++ b/marked/T/T-REC-T.122-199802-I_PDF-E/0a42e05c07941450f34e4f7117725834_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:8df7879d35d3a654aaa38a508f621b5d4e5a1312df2fab4ffc1466b903694470
+size 59428
diff --git a/marked/T/T-REC-T.122-199802-I_PDF-E/0b7849dae424b0dd33e6386d2384643a_img.jpg b/marked/T/T-REC-T.122-199802-I_PDF-E/0b7849dae424b0dd33e6386d2384643a_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..9017f585508cf4de2b4af936348dd694a0ecdf5b
--- /dev/null
+++ b/marked/T/T-REC-T.122-199802-I_PDF-E/0b7849dae424b0dd33e6386d2384643a_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:dc1022d7e42da0b24f873268390b6711ee050d2e1522d24821b632b075e58c39
+size 125103
diff --git a/marked/T/T-REC-T.122-199802-I_PDF-E/1142ba0197b158bb198186fe8baccc32_img.jpg b/marked/T/T-REC-T.122-199802-I_PDF-E/1142ba0197b158bb198186fe8baccc32_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..fbf58024d855a5462a6f7bfc161e05c5b22addff
--- /dev/null
+++ b/marked/T/T-REC-T.122-199802-I_PDF-E/1142ba0197b158bb198186fe8baccc32_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:36027f942980241f797b9c0e194239d1135e414223fe8a698e324e92dc8cdfed
+size 26902
diff --git a/marked/T/T-REC-T.122-199802-I_PDF-E/171115f072e42b379238ed0dd438e9d7_img.jpg b/marked/T/T-REC-T.122-199802-I_PDF-E/171115f072e42b379238ed0dd438e9d7_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..23a7e001310c8f96940f4569cac67e9e516a9211
--- /dev/null
+++ b/marked/T/T-REC-T.122-199802-I_PDF-E/171115f072e42b379238ed0dd438e9d7_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:29cb8ec9c47bfec25d9fd7772efe63f856f66d8bece2d46aedc8af2561b37c44
+size 21271
diff --git a/marked/T/T-REC-T.122-199802-I_PDF-E/19a59d6b53059ebd27b13c98793f88e0_img.jpg b/marked/T/T-REC-T.122-199802-I_PDF-E/19a59d6b53059ebd27b13c98793f88e0_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..a85fd6f968240a836a2da5b0db42e9f85b40b929
--- /dev/null
+++ b/marked/T/T-REC-T.122-199802-I_PDF-E/19a59d6b53059ebd27b13c98793f88e0_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:f9ebd0a868328df762013c25e18a4baa3a3e4cc59bbfed27db913b1e4d8f51dc
+size 15273
diff --git a/marked/T/T-REC-T.122-199802-I_PDF-E/19a5f0db57a21a0e82a7f326083e96fd_img.jpg b/marked/T/T-REC-T.122-199802-I_PDF-E/19a5f0db57a21a0e82a7f326083e96fd_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..45ef1b89bbfef7d1370e8f70eee345fb6297d21b
--- /dev/null
+++ b/marked/T/T-REC-T.122-199802-I_PDF-E/19a5f0db57a21a0e82a7f326083e96fd_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:0d71142b311dd3cd359ecb15a7e896a0ad1d549b4b9873d94002df252efeb0d6
+size 22217
diff --git a/marked/T/T-REC-T.122-199802-I_PDF-E/2834bdd6eb8540277e609decbb924003_img.jpg b/marked/T/T-REC-T.122-199802-I_PDF-E/2834bdd6eb8540277e609decbb924003_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..fa6e4c93da0e8b821fa1b0a036bb2498480f2a72
--- /dev/null
+++ b/marked/T/T-REC-T.122-199802-I_PDF-E/2834bdd6eb8540277e609decbb924003_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:9009d96da6a17ec3c7b00c9ceeb4b08c9859d57f747ddf05acfdb88d6ed3936e
+size 20232
diff --git a/marked/T/T-REC-T.122-199802-I_PDF-E/28d75f39a24203712ee907b32cf0bbe5_img.jpg b/marked/T/T-REC-T.122-199802-I_PDF-E/28d75f39a24203712ee907b32cf0bbe5_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..e6f2dd28ba408baf8ea49fca67c402c3d47f0c35
--- /dev/null
+++ b/marked/T/T-REC-T.122-199802-I_PDF-E/28d75f39a24203712ee907b32cf0bbe5_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:f493acb343d132a93323f0bf89ae14bab840ab5d07395deadb2a20cd27168c6e
+size 23769
diff --git a/marked/T/T-REC-T.122-199802-I_PDF-E/2bacc162a73d75c43a7f90715832bd13_img.jpg b/marked/T/T-REC-T.122-199802-I_PDF-E/2bacc162a73d75c43a7f90715832bd13_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..75991d165b72664764061c2f07a898ab5c2e72e5
--- /dev/null
+++ b/marked/T/T-REC-T.122-199802-I_PDF-E/2bacc162a73d75c43a7f90715832bd13_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:a39eba92143db8af27e21cc73ca2c43f31274aefe3f696225c30eea65f3aa0ab
+size 23899
diff --git a/marked/T/T-REC-T.122-199802-I_PDF-E/2cde062fd82833415971a8bd1a2cafab_img.jpg b/marked/T/T-REC-T.122-199802-I_PDF-E/2cde062fd82833415971a8bd1a2cafab_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..e38aff9201cfbd9ad71e59ad397b64a637967fcf
--- /dev/null
+++ b/marked/T/T-REC-T.122-199802-I_PDF-E/2cde062fd82833415971a8bd1a2cafab_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:9aedc942854ababdfea2aa94c835568c76f9ef54c74920ea66a99eb0697c9a6d
+size 31778
diff --git a/marked/T/T-REC-T.122-199802-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/T/T-REC-T.122-199802-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..1723d1ac9d7ca695483b4ee78b2146bb205bd40f
--- /dev/null
+++ b/marked/T/T-REC-T.122-199802-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:3a476b0bb69b73efd4b8fb1fd297be8f9433ccabfab6391fa767f830c8429442
+size 8239
diff --git a/marked/T/T-REC-T.122-199802-I_PDF-E/318886a86a1dcc59e1fc83db6f157c60_img.jpg b/marked/T/T-REC-T.122-199802-I_PDF-E/318886a86a1dcc59e1fc83db6f157c60_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..6565d0812700e3ea05a574df62e0fcc08d39d997
--- /dev/null
+++ b/marked/T/T-REC-T.122-199802-I_PDF-E/318886a86a1dcc59e1fc83db6f157c60_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:f1b163390eb0d66c23e90b893225f237ba961ff53d80cfcfe364f730ae7b7af9
+size 29851
diff --git a/marked/T/T-REC-T.122-199802-I_PDF-E/4c731b7bb6a5851992b8b7440b4e9356_img.jpg b/marked/T/T-REC-T.122-199802-I_PDF-E/4c731b7bb6a5851992b8b7440b4e9356_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..8f8fb7f596d3899480e78f110460cbf65615c5bc
--- /dev/null
+++ b/marked/T/T-REC-T.122-199802-I_PDF-E/4c731b7bb6a5851992b8b7440b4e9356_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:475a62096ee7120c96896fe93cef990e461534e07dfb5fb08d11ab1f57b594e9
+size 16721
diff --git a/marked/T/T-REC-T.122-199802-I_PDF-E/4cde160bcc69b7b6c81b648dd0e4252e_img.jpg b/marked/T/T-REC-T.122-199802-I_PDF-E/4cde160bcc69b7b6c81b648dd0e4252e_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..ba3a5b3337db3478d3db14246d458a104990f3ed
--- /dev/null
+++ b/marked/T/T-REC-T.122-199802-I_PDF-E/4cde160bcc69b7b6c81b648dd0e4252e_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:a9a9794298ea4427f26388f3218a402b739454709749b7dc64a1eb3bfab178a5
+size 12567
diff --git a/marked/T/T-REC-T.122-199802-I_PDF-E/5414f65867392f05ba0063b208eeb5e1_img.jpg b/marked/T/T-REC-T.122-199802-I_PDF-E/5414f65867392f05ba0063b208eeb5e1_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..e718d77d1ef93e8821c573e226e301d408c63997
--- /dev/null
+++ b/marked/T/T-REC-T.122-199802-I_PDF-E/5414f65867392f05ba0063b208eeb5e1_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:ad2449ba5bafc0a1dedb5a9c68a2ebf5b42f0838e0ff8d1590a09f757f9c689a
+size 21008
diff --git a/marked/T/T-REC-T.122-199802-I_PDF-E/5eb69662cc4fa7d0d49b4eb22951c204_img.jpg b/marked/T/T-REC-T.122-199802-I_PDF-E/5eb69662cc4fa7d0d49b4eb22951c204_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..4a9f52d27cf22909fe0d3365383fe1c0f1422ee2
--- /dev/null
+++ b/marked/T/T-REC-T.122-199802-I_PDF-E/5eb69662cc4fa7d0d49b4eb22951c204_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:d0a3510f6d5318ac8786c4e363db91f9caaaa0018b10761ead637c30e7269d23
+size 70671
diff --git a/marked/T/T-REC-T.122-199802-I_PDF-E/60ffbad6c0fb7371a57fe8f267d2d141_img.jpg b/marked/T/T-REC-T.122-199802-I_PDF-E/60ffbad6c0fb7371a57fe8f267d2d141_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..42e1d4cffc71e3abedb923fb9c16477ce5fe1399
--- /dev/null
+++ b/marked/T/T-REC-T.122-199802-I_PDF-E/60ffbad6c0fb7371a57fe8f267d2d141_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:1f67c4287ee332811ebbb7addcf6ab755c8700b3db6e566b8b781a4e15673509
+size 49481
diff --git a/marked/T/T-REC-T.122-199802-I_PDF-E/627c5195eaae3bc7e34cbc4dbdb6f9a8_img.jpg b/marked/T/T-REC-T.122-199802-I_PDF-E/627c5195eaae3bc7e34cbc4dbdb6f9a8_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..8e51fd5f54a338b7d9c254a474c292ab9e6b8c8f
--- /dev/null
+++ b/marked/T/T-REC-T.122-199802-I_PDF-E/627c5195eaae3bc7e34cbc4dbdb6f9a8_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:9c1f01eed617aa69879ac18bad4a41aa9ec57d01f0df08b41a6dbf82bee7aedd
+size 19643
diff --git a/marked/T/T-REC-T.122-199802-I_PDF-E/759c7d62402f0b4651ddce292be5bdef_img.jpg b/marked/T/T-REC-T.122-199802-I_PDF-E/759c7d62402f0b4651ddce292be5bdef_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..07efa8f5f27ed6b099fd573719ebf3a220814451
--- /dev/null
+++ b/marked/T/T-REC-T.122-199802-I_PDF-E/759c7d62402f0b4651ddce292be5bdef_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:c2100e13df361f79291a0474cfc1d21648e32f62a2d7f7bc78cf1d89207e20be
+size 18943
diff --git a/marked/T/T-REC-T.122-199802-I_PDF-E/76b0cd79baaedd942af4dc42f2e764b8_img.jpg b/marked/T/T-REC-T.122-199802-I_PDF-E/76b0cd79baaedd942af4dc42f2e764b8_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..c4ea795be00b848450225f73f1b015d2bb628dde
--- /dev/null
+++ b/marked/T/T-REC-T.122-199802-I_PDF-E/76b0cd79baaedd942af4dc42f2e764b8_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:434504d6015b32140a07f9be01481d8a4111d0ea19a581f3435bfa3841e04bf1
+size 26693
diff --git a/marked/T/T-REC-T.122-199802-I_PDF-E/77464a47f104d0d647b2414591137b64_img.jpg b/marked/T/T-REC-T.122-199802-I_PDF-E/77464a47f104d0d647b2414591137b64_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..c72a33f5a1980e4378778c9e7ba0267a02758997
--- /dev/null
+++ b/marked/T/T-REC-T.122-199802-I_PDF-E/77464a47f104d0d647b2414591137b64_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:50efb4bcfe26f2b299b81fce128c88b16dfc1915cdf8fd5fd7d34d7d0bd03deb
+size 19850
diff --git a/marked/T/T-REC-T.122-199802-I_PDF-E/77959075c823bb5169480d7b8ff82a63_img.jpg b/marked/T/T-REC-T.122-199802-I_PDF-E/77959075c823bb5169480d7b8ff82a63_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..bb8db53041ac2ed98c07bbe434e3cd4f7ac2f426
--- /dev/null
+++ b/marked/T/T-REC-T.122-199802-I_PDF-E/77959075c823bb5169480d7b8ff82a63_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:0aaaf79c425ca2a3fec86a37758dc9c0a7c86a9a5850e5f65891ef887ad8f640
+size 99951
diff --git a/marked/T/T-REC-T.122-199802-I_PDF-E/834fb96b114b8fdc001625e1ae28e8b1_img.jpg b/marked/T/T-REC-T.122-199802-I_PDF-E/834fb96b114b8fdc001625e1ae28e8b1_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..a3aa57a7caa8acc2d2b77f4b4a2b8e0c10807844
--- /dev/null
+++ b/marked/T/T-REC-T.122-199802-I_PDF-E/834fb96b114b8fdc001625e1ae28e8b1_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:6261e6960ae206af798490d232cdea894a15c34079ffa1e6871c91453ed61ba0
+size 48724
diff --git a/marked/T/T-REC-T.122-199802-I_PDF-E/8d325fc12b494e42c9ea7ed2a7f327a6_img.jpg b/marked/T/T-REC-T.122-199802-I_PDF-E/8d325fc12b494e42c9ea7ed2a7f327a6_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..accc6265ad455bb871029b79231a4202c26a2a7e
--- /dev/null
+++ b/marked/T/T-REC-T.122-199802-I_PDF-E/8d325fc12b494e42c9ea7ed2a7f327a6_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:11dc6e7b7f998047c9b5763212b3e893b048ed1164f3f2ff209b663fff8c9f5a
+size 9839
diff --git a/marked/T/T-REC-T.122-199802-I_PDF-E/9a5927586a691c4908aa2cf98bd47ebb_img.jpg b/marked/T/T-REC-T.122-199802-I_PDF-E/9a5927586a691c4908aa2cf98bd47ebb_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..a1f326244de5c3d2343284be86da4ceb996016e3
--- /dev/null
+++ b/marked/T/T-REC-T.122-199802-I_PDF-E/9a5927586a691c4908aa2cf98bd47ebb_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:fdad216a0ba523f8edb7bab65d79fec050ae492979cee87f3fe10a704c0dcf8e
+size 70136
diff --git a/marked/T/T-REC-T.122-199802-I_PDF-E/a0739aaf13fa5a632d4faa830f6b2708_img.jpg b/marked/T/T-REC-T.122-199802-I_PDF-E/a0739aaf13fa5a632d4faa830f6b2708_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..be9b8396f7b590a40d7957b740ae3a579a9a26e4
--- /dev/null
+++ b/marked/T/T-REC-T.122-199802-I_PDF-E/a0739aaf13fa5a632d4faa830f6b2708_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:deff9114b9bcc44ad7ce5dcb6e8ab8bb553c51f88ca7ddde2055a3352694ccac
+size 13312
diff --git a/marked/T/T-REC-T.122-199802-I_PDF-E/a33da0f14e456f92539ce3e9b7d81f9a_img.jpg b/marked/T/T-REC-T.122-199802-I_PDF-E/a33da0f14e456f92539ce3e9b7d81f9a_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..17b606d4e5df0eaaea3ff6c89608919a8943fd5b
--- /dev/null
+++ b/marked/T/T-REC-T.122-199802-I_PDF-E/a33da0f14e456f92539ce3e9b7d81f9a_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:de506d35aaf9650d61ebadef1af27f28e2fbc985bdc626fef0638f2d4bd5c11c
+size 91001
diff --git a/marked/T/T-REC-T.122-199802-I_PDF-E/a3472689858b068ef469213682965325_img.jpg b/marked/T/T-REC-T.122-199802-I_PDF-E/a3472689858b068ef469213682965325_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..826f402c181173e80cf80c13c28afbe503d2be82
--- /dev/null
+++ b/marked/T/T-REC-T.122-199802-I_PDF-E/a3472689858b068ef469213682965325_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:7b589474ac34dd6713bae468b244388e1a58931fa972b2405ccebe0c603cec14
+size 18577
diff --git a/marked/T/T-REC-T.122-199802-I_PDF-E/a4b963a07cc368283154762c4b156fe7_img.jpg b/marked/T/T-REC-T.122-199802-I_PDF-E/a4b963a07cc368283154762c4b156fe7_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..1e91232a3d848e80ec6e4af4e05b4de8b231188f
--- /dev/null
+++ b/marked/T/T-REC-T.122-199802-I_PDF-E/a4b963a07cc368283154762c4b156fe7_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:419ab5fb32ab436b02c8f47d3c01493804d15e97248afcb35473d0b58d437710
+size 15431
diff --git a/marked/T/T-REC-T.122-199802-I_PDF-E/a7585024ebe2bba8ac0757150a12759a_img.jpg b/marked/T/T-REC-T.122-199802-I_PDF-E/a7585024ebe2bba8ac0757150a12759a_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..1834554aa4929be7b8fb9a69b26831c11abe515f
--- /dev/null
+++ b/marked/T/T-REC-T.122-199802-I_PDF-E/a7585024ebe2bba8ac0757150a12759a_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:eaa8f023a39e5f29a4f61aef762db7f70d4cc84e322d04c808b7fb4b892c69ae
+size 20022
diff --git a/marked/T/T-REC-T.122-199802-I_PDF-E/af7916c89a458fdab6c3f443217388ae_img.jpg b/marked/T/T-REC-T.122-199802-I_PDF-E/af7916c89a458fdab6c3f443217388ae_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..e2d7e1686def552c328574e489b1b8f82497743e
--- /dev/null
+++ b/marked/T/T-REC-T.122-199802-I_PDF-E/af7916c89a458fdab6c3f443217388ae_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:47cc529a46d8754134a0dd58ffd52f85a6ba1218762e4d296455438a7a1236a5
+size 31010
diff --git a/marked/T/T-REC-T.122-199802-I_PDF-E/bb3354f497635d15bef873577125c48d_img.jpg b/marked/T/T-REC-T.122-199802-I_PDF-E/bb3354f497635d15bef873577125c48d_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..09218bdbdc0ea42757270f17de6864209b60da56
--- /dev/null
+++ b/marked/T/T-REC-T.122-199802-I_PDF-E/bb3354f497635d15bef873577125c48d_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:368609fa47ccbddc419ed7203244c7837bbcb0952776032b6649d4ee40b293de
+size 16124
diff --git a/marked/T/T-REC-T.122-199802-I_PDF-E/c5655e700cc3e9aac7e9f4f07f30264d_img.jpg b/marked/T/T-REC-T.122-199802-I_PDF-E/c5655e700cc3e9aac7e9f4f07f30264d_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..4246ac92e14721c31a193fad9d50b7f64ab1f2f0
--- /dev/null
+++ b/marked/T/T-REC-T.122-199802-I_PDF-E/c5655e700cc3e9aac7e9f4f07f30264d_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:8e67637af2dcd281ca7fb5a7860a550c5e2a8e4124df0a28678fce407d1d9e55
+size 29588
diff --git a/marked/T/T-REC-T.122-199802-I_PDF-E/c803f6f6e2c49429d2951832bd0f208d_img.jpg b/marked/T/T-REC-T.122-199802-I_PDF-E/c803f6f6e2c49429d2951832bd0f208d_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..b6406f41edccbdb7ee24865ee4d0095f76348dce
--- /dev/null
+++ b/marked/T/T-REC-T.122-199802-I_PDF-E/c803f6f6e2c49429d2951832bd0f208d_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:62fa14934a0314a178423207cc0223cb6bbe600484e8700326783190c6789eeb
+size 10343
diff --git a/marked/T/T-REC-T.122-199802-I_PDF-E/cbb2d311b20781a595488445ded48d0a_img.jpg b/marked/T/T-REC-T.122-199802-I_PDF-E/cbb2d311b20781a595488445ded48d0a_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..8f860f4bffcd6acfdc5d44ba0b000ab230d34188
--- /dev/null
+++ b/marked/T/T-REC-T.122-199802-I_PDF-E/cbb2d311b20781a595488445ded48d0a_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:106e78a8557f0b849bfabd3f944abef82d2dda3cb14b113d1aac7739a4c64ed6
+size 60232
diff --git a/marked/T/T-REC-T.122-199802-I_PDF-E/d4af765160d04ecef538e5066006dc77_img.jpg b/marked/T/T-REC-T.122-199802-I_PDF-E/d4af765160d04ecef538e5066006dc77_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..918d670cf1854cb0525b8ddb2986b9ceaf384db1
--- /dev/null
+++ b/marked/T/T-REC-T.122-199802-I_PDF-E/d4af765160d04ecef538e5066006dc77_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:a4499fe74838f2cf852fa1e388bf8fb824e238b1095eaaf203fe3aa252826e66
+size 55377
diff --git a/marked/T/T-REC-T.122-199802-I_PDF-E/d8698aacaeead6dfed9a1e448670a2e4_img.jpg b/marked/T/T-REC-T.122-199802-I_PDF-E/d8698aacaeead6dfed9a1e448670a2e4_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..d3dba178bca0584df07a90c36194cf3cd139dfb4
--- /dev/null
+++ b/marked/T/T-REC-T.122-199802-I_PDF-E/d8698aacaeead6dfed9a1e448670a2e4_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:b929fbabf0499b099dbb91d373420425e99ec58a2b08ff320b77be5c6840b1a3
+size 15559
diff --git a/marked/T/T-REC-T.122-199802-I_PDF-E/dcc2d5a5b39f780e7a224bb01ba1ef6e_img.jpg b/marked/T/T-REC-T.122-199802-I_PDF-E/dcc2d5a5b39f780e7a224bb01ba1ef6e_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..20da75605e8dbc54da183e40f5f1f04d0e1084df
--- /dev/null
+++ b/marked/T/T-REC-T.122-199802-I_PDF-E/dcc2d5a5b39f780e7a224bb01ba1ef6e_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:3f65daa0760664956ddc6020a6b66533aa00578b9644a3048f99f756dcbdf63d
+size 16005
diff --git a/marked/T/T-REC-T.122-199802-I_PDF-E/e05b36c0d46549e681ce6581422c66b2_img.jpg b/marked/T/T-REC-T.122-199802-I_PDF-E/e05b36c0d46549e681ce6581422c66b2_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..da843b74dc76093ed1e5f97b2a7ccd88ebdb4791
--- /dev/null
+++ b/marked/T/T-REC-T.122-199802-I_PDF-E/e05b36c0d46549e681ce6581422c66b2_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:61f5d6379173502e0a22d9fc24ca1fde1dff2a4f29caac2ba4a05c9d110dd964
+size 16750
diff --git a/marked/T/T-REC-T.122-199802-I_PDF-E/e29665b8abcea967ef289c6aff07ae4c_img.jpg b/marked/T/T-REC-T.122-199802-I_PDF-E/e29665b8abcea967ef289c6aff07ae4c_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..1d174c387679cef04d28ae8806334e0dff818f16
--- /dev/null
+++ b/marked/T/T-REC-T.122-199802-I_PDF-E/e29665b8abcea967ef289c6aff07ae4c_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:c99fa69b056f9f165d87d4177209b93fb13b4e67f8413b662476490239d8d0b9
+size 12179
diff --git a/marked/T/T-REC-T.122-199802-I_PDF-E/ed48e24e36ea0501953177401c900f86_img.jpg b/marked/T/T-REC-T.122-199802-I_PDF-E/ed48e24e36ea0501953177401c900f86_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..122c9b9ed05c8a7511a05d6539d5c19b31be1ca9
--- /dev/null
+++ b/marked/T/T-REC-T.122-199802-I_PDF-E/ed48e24e36ea0501953177401c900f86_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:995e756086e46eed7f481ea8292710a0a51c4b099b378e58238d66e731942a05
+size 23498
diff --git a/marked/T/T-REC-T.122-199802-I_PDF-E/f142b022cfc716cd967297f027efe647_img.jpg b/marked/T/T-REC-T.122-199802-I_PDF-E/f142b022cfc716cd967297f027efe647_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..28b6740c81a019721fa10bed9c3f3303784a0d65
--- /dev/null
+++ b/marked/T/T-REC-T.122-199802-I_PDF-E/f142b022cfc716cd967297f027efe647_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:db82426b94ce3dcd13dfc6b6a73b03263be18f1fdf758cc6e8c2259028a29dd2
+size 39409
diff --git a/marked/T/T-REC-T.122-199802-I_PDF-E/f5a5f52bc25d95a7f616290c99e88ae6_img.jpg b/marked/T/T-REC-T.122-199802-I_PDF-E/f5a5f52bc25d95a7f616290c99e88ae6_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..c6c0380fd009a40619efdabe4e8b634331c09e19
--- /dev/null
+++ b/marked/T/T-REC-T.122-199802-I_PDF-E/f5a5f52bc25d95a7f616290c99e88ae6_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:5491de377668d2f8e9fde406519251c7a2821de2d203dcf1397f73b0f710c01c
+size 58041
diff --git a/marked/T/T-REC-T.122-199802-I_PDF-E/ff0952ef692c9d960ce5f6708bcc9711_img.jpg b/marked/T/T-REC-T.122-199802-I_PDF-E/ff0952ef692c9d960ce5f6708bcc9711_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..cfd1f732dce79d4f17f8fda81c3fd9c0fa0796da
--- /dev/null
+++ b/marked/T/T-REC-T.122-199802-I_PDF-E/ff0952ef692c9d960ce5f6708bcc9711_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:3557c63f612a6dddce73bad3f73482e4fad9536cbb4fe1a56310225adb1c3b70
+size 80885
diff --git a/marked/T/T-REC-T.122-199802-I_PDF-E/raw.md b/marked/T/T-REC-T.122-199802-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..f8a62853e06f630980eeda191e568d7604e4ea96
--- /dev/null
+++ b/marked/T/T-REC-T.122-199802-I_PDF-E/raw.md
@@ -0,0 +1,1682 @@
+
+
+![ITU logo: a globe with the letters ITU inside, crossed by a lightning bolt.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg)
+
+ITU logo: a globe with the letters ITU inside, crossed by a lightning bolt.
+
+INTERNATIONAL TELECOMMUNICATION UNION
+
+# ITU-T
+
+TELECOMMUNICATION  
+STANDARDIZATION SECTOR  
+OF ITU
+
+# T.122
+
+(02/98)
+
+SERIES T: TERMINALS FOR TELEMATIC SERVICES
+
+---
+
+# **Multipoint communication service – Service definition**
+
+ITU-T Recommendation T.122
+
+(Previously CCITT Recommendation)
+
+---
+
+## ITU-T T-SERIES RECOMMENDATIONS **TERMINALS FOR TELEMATIC SERVICES**
+
+![A large empty rectangular box with a double border.](c803f6f6e2c49429d2951832bd0f208d_img.jpg)
+
+A large empty rectangular box with a double border.
+
+*For further details, please refer to ITU-T List of Recommendations.*
+
+## **ITU-T RECOMMENDATION T.122**
+
+# **MULTIPOINT COMMUNICATION SERVICE – SERVICE DEFINITION**
+
+## **Summary**
+
+This Recommendation defines a multipoint data delivery service for use in the audiographics and audiovisual conferencing service. It provides the mechanism for multipoint aware applications to send data to all or a subset of the group with a single send primitive and to force, if desired, a uniformly sequenced reception of data at all users. It also provides a token mechanism to allow applications to control scarce resources or do multi-application signalling and synchronization. These services are provided in a manner that is independent of the underlying network connections.
+
+The following changes have been incorporated into this Recommendation:
+
+- Support for unreliable data transfer was added.
+- Under certain conditions, MCS protocol version is allowed to differ between providers within a domain.
+- The MCS-DOMAIN-PARAMETERS service primitive was added.
+- Parameters were added to MCS-SEND-DATA and MCS-UNIFORM-SEND-DATA service primitives to facilitate data reassembly by the user application.
+- Minor changes have been made to the Recommendation format.
+
+## **Source**
+
+ITU-T Recommendation T.122 was revised by ITU-T Study Group 16 (1997-2000) and was approved under the WTSC Resolution No. 1 procedure on the 6th of February 1998.
+
+## FOREWORD
+
+ITU (International Telecommunication Union) is the United Nations Specialized Agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the ITU. The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis.
+
+The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics.
+
+The approval of Recommendations by the Members of the ITU-T is covered by the procedure laid down in WTSC Resolution No. 1.
+
+In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC.
+
+## NOTE
+
+In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+## INTELLECTUAL PROPERTY RIGHTS
+
+The ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. The ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process.
+
+As of the date of approval of this Recommendation, the ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementors are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database.
+
+© ITU 1998
+
+All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU.
+
+# CONTENTS
+
+|                                                                  | <b>Page</b> |
+|------------------------------------------------------------------|-------------|
+| 1 Scope.....                                                     | 1           |
+| 2 References.....                                                | 1           |
+| 3 Definitions .....                                              | 2           |
+| 4 Abbreviations.....                                             | 3           |
+| 5 Conventions .....                                              | 3           |
+| 5.1 Primitive parameters conventions.....                        | 3           |
+| 5.2 Primitive notations.....                                     | 3           |
+| 6 Model of MCS .....                                             | 3           |
+| 7 MCS connections and building the domain.....                   | 4           |
+| 7.1 Establishing connections and binding them to the domain..... | 4           |
+| 7.2 Attaching application users to a domain.....                 | 6           |
+| 7.3 MCS-DOMAIN-PARAMETERS.....                                   | 6           |
+| 8 MCS channels .....                                             | 7           |
+| 8.1 Multicast channels .....                                     | 7           |
+| 8.2 Single-member channels.....                                  | 7           |
+| 8.3 Private channels .....                                       | 8           |
+| 8.4 Channel Id numbering.....                                    | 8           |
+| 9 MCS data transfer .....                                        | 8           |
+| 9.1 Simple Send.....                                             | 8           |
+| 9.2 Uniformly sequenced data transfer .....                      | 9           |
+| 9.3 Send data with responses (For further study).....            | 9           |
+| 9.4 Unreliable data transfer.....                                | 10          |
+| 10 Token management.....                                         | 10          |
+| 10.1 Exclusive event control and transfer.....                   | 10          |
+| 10.2 Event coordination.....                                     | 11          |
+| 10.3 Token Id Numbering.....                                     | 11          |
+| 11 Introduction to MCS service primitives.....                   | 11          |
+| 11.1 MCS domain management primitives .....                      | 11          |
+| 11.2 MCS Channel Management primitives.....                      | 11          |
+| 11.3 MCS data transfer primitives.....                           | 11          |
+| 11.4 MCS token management primitives .....                       | 11          |
+
+|                                                       | <b>Page</b> |
+|-------------------------------------------------------|-------------|
+| 12 MCS domain management primitives .....             | 12          |
+| 12.1 MCS-CONNECT-PROVIDER.....                        | 12          |
+| 12.1.1 Function .....                                 | 12          |
+| 12.1.2 Types of primitives and their parameters ..... | 12          |
+| 12.1.3 Sequence of primitives .....                   | 13          |
+| 12.2 MCS-DISCONNECT-PROVIDER .....                    | 14          |
+| 12.2.1 Function .....                                 | 14          |
+| 12.2.2 Types of primitives and their parameters ..... | 14          |
+| 12.2.3 Sequence of primitives .....                   | 14          |
+| 12.3 MCS-ATTACH-USER.....                             | 15          |
+| 12.3.1 Function .....                                 | 15          |
+| 12.3.2 Types of primitives and their parameters ..... | 15          |
+| 12.3.3 Sequence of primitives .....                   | 15          |
+| 12.4 MCS-DETACH-USER.....                             | 15          |
+| 12.4.1 Function .....                                 | 15          |
+| 12.4.2 Types of primitives and their parameters ..... | 16          |
+| 12.4.3 Sequence of primitives .....                   | 16          |
+| 12.5 MCS-DOMAIN-PARAMETERS.....                       | 16          |
+| 12.5.1 Function .....                                 | 16          |
+| 12.5.2 Types of primitives and their parameters ..... | 17          |
+| 12.5.3 Sequence of primitives .....                   | 17          |
+| 13 MCS channel management primitives .....            | 18          |
+| 13.1 MCS-CHANNEL-JOIN.....                            | 18          |
+| 13.1.1 Function .....                                 | 18          |
+| 13.1.2 Types of primitives and their parameters ..... | 18          |
+| 13.1.3 Sequence of primitives .....                   | 18          |
+| 13.2 MCS-CHANNEL-LEAVE .....                          | 18          |
+| 13.2.1 Function .....                                 | 18          |
+| 13.2.2 Types of primitives and their parameters ..... | 19          |
+| 13.2.3 Sequence of primitives .....                   | 19          |
+| 13.3 MCS-CHANNEL-CONVENE .....                        | 19          |
+| 13.3.1 Function .....                                 | 19          |
+| 13.3.2 Types of primitives and their parameters ..... | 20          |
+| 13.3.3 Sequence of primitives .....                   | 20          |
+| 13.4 MCS-CHANNEL-DISBAND.....                         | 20          |
+| 13.4.1 Function .....                                 | 20          |
+| 13.4.2 Types of primitives and their parameters ..... | 20          |
+
+|                                                       | <b>Page</b> |
+|-------------------------------------------------------|-------------|
+| 13.4.3 Sequence of primitives .....                   | 21          |
+| 13.5 MCS-CHANNEL-ADMIT .....                          | 21          |
+| 13.5.1 Function .....                                 | 21          |
+| 13.5.2 Types of primitives and their parameters ..... | 21          |
+| 13.5.3 Sequence of primitives .....                   | 22          |
+| 13.6 MCS-CHANNEL-EXPEL .....                          | 22          |
+| 13.6.1 Function .....                                 | 22          |
+| 13.6.2 Types of primitives and their parameters ..... | 22          |
+| 13.6.3 Sequence of primitives .....                   | 22          |
+| 14 MCS data transfer primitives .....                 | 23          |
+| 14.1 MCS-SEND-DATA .....                              | 23          |
+| 14.1.1 Function .....                                 | 23          |
+| 14.1.2 Types of primitives and their parameters ..... | 23          |
+| 14.1.3 Sequence of primitives .....                   | 24          |
+| 14.2 MCS-UNIFORMLY-SEQUENCED-SEND-DATA .....          | 24          |
+| 14.2.1 Function .....                                 | 24          |
+| 14.2.2 Types of primitives and their parameters ..... | 24          |
+| 14.2.3 Sequence of primitives .....                   | 25          |
+| 15 MCS token management primitives .....              | 25          |
+| 15.1 MCS-TOKEN-GRAB .....                             | 25          |
+| 15.1.1 Function .....                                 | 25          |
+| 15.1.2 Types of primitives and their parameters ..... | 26          |
+| 15.1.3 Sequence of primitives .....                   | 26          |
+| 15.2 MCS-TOKEN-INHIBIT .....                          | 26          |
+| 15.2.1 Function .....                                 | 26          |
+| 15.2.2 Types of primitives and their parameters ..... | 26          |
+| 15.2.3 Sequence of primitives .....                   | 27          |
+| 15.3 MCS-TOKEN-GIVE .....                             | 27          |
+| 15.3.1 Function .....                                 | 27          |
+| 15.3.2 Types of primitives and their parameters ..... | 27          |
+| 15.3.3 Sequence of primitives .....                   | 28          |
+| 15.4 MCS-TOKEN-PLEASE .....                           | 28          |
+| 15.4.1 Function .....                                 | 28          |
+| 15.4.2 Types of primitives and their parameters ..... | 28          |
+| 15.4.3 Sequence of primitives .....                   | 29          |
+| 15.5 MCS-TOKEN-RELEASE .....                          | 29          |
+| 15.5.1 Function .....                                 | 29          |
+
+|                                                                                 | <b>Page</b> |
+|---------------------------------------------------------------------------------|-------------|
+| 15.5.2 Types of primitives and their parameters .....                           | 29          |
+| 15.5.3 Sequence of primitives .....                                             | 29          |
+| 15.6 MCS-TOKEN-TEST .....                                                       | 30          |
+| 15.6.1 Function .....                                                           | 30          |
+| 15.6.2 Types of primitives and their parameters .....                           | 30          |
+| 15.6.3 Sequence of primitives .....                                             | 30          |
+| Annex A – Domain establishment, data transfer and release phases examples ..... | 30          |
+| A.1 MCS domain establishment phase .....                                        | 30          |
+| A.2 MCS data transfer phase .....                                               | 35          |
+| A.3 MCS connection release phase .....                                          | 37          |
+| Appendix I – Distributed token control .....                                    | 38          |
+
+## **Recommendation T.122**
+
+# **MULTIPOINT COMMUNICATION SERVICE – SERVICE DEFINITION**
+
+*(revised in 1998)*
+
+## **1 Scope**
+
+The Multipoint Communication Service (MCS) is a generic service designed to support highly interactive multimedia conferencing applications. It supports full-duplex multipoint communication among an arbitrary number of connected application entities over a variety of networks as specified in Recommendation T.123. This version of MCS utilizes only the basic mode of Recommendation T.123. MCS provides efficient multicast message sequencing and token management features by means of an MCS provider, to which users are connected either directly or through other MCS providers.
+
+MCS offers the following features:
+
+- a) Flexible modes of data transfer:
+  - Broadcast, with flow control;
+  - Request/Response.
+- b) Multipoint addressing:
+  - One to all;
+  - One to sub-group;
+  - One to one.
+- c) Multipoint routing of data:
+  - Shortest path to each receiver;
+  - Uniform sequencing of data, where all users receive the same data in the same sequence.
+- d) Tokens are provided for resource contention resolution.
+- e) Network independent:
+  - For fully reliable data transmission, MCS assumes the use of error-free transport connections that provide flow control (see Recommendation T.123).
+
+MCS provides information to conference participants about other participants only in cases where this information cannot be provided by the participants themselves. For example, members of a domain are not informed when a new member joins (the new member can do so if it wishes), whereas they are informed by MCS when a member detaches, since the departing member may have no opportunity to inform the others.
+
+## **2 References**
+
+The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; all users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published.
+
+- ITU-T Recommendation F.710 (1991), *General principles for audiographic conference service*.
+- ITU-T Recommendation T.123 (1996), *Network specific data protocol stacks for multimedia conferencing*.
+
+## 3 Definitions
+
+This Recommendation defines the following terms:
+
+**3.1 MCS provider:** An entity (i.e. active element) of an MCS subsystem, interacting directly with application entities above and transport entities below. The services it provides and the services it uses are modelled in terms of abstract primitives. An MCS provider communicates with peer MCS providers.
+
+**3.2 MCS domain:** A tree of MCS connections among MCS providers or, in the degenerate case, part of a single MCS provider. The MCS providers involved are said to *host* the domain. A domain sets the boundary for data transfer among attached MCS users.
+
+**3.3 MCS domain selector:** An octet string that distinguishes multiple domains hosted by the same MCS provider. The creation of MCS providers, their configuration to host one or more domains, and the internal structure of domain selectors are all local matters.
+
+**3.4 top MCS provider:** In every domain a single MCS provider will become the Top MCS Provider and will be the exclusive manager of all the domain's channel, user Ids and token resources.
+
+**3.5 MCS connection:** A specified set of transport connections, managed as one unit, between a pair of MCS providers. Each end of an MCS Connection is bound to a respective MCS domain selector. One end of each MCS Connection is designated to be hierarchically superior to the other.
+
+**3.6 MCS user:** An application entity obtaining services from an MCS provider. Once they have been attached to the same domain, MCS users can transfer data in point-to-point or multicast fashion.
+
+**3.7 MCS Service Access Point (MCSAP):** A point through which an MCS user accesses an MCS provider.
+
+**3.8 MCS attachment:** A multi-connection end point within an MCSAP. Each MCS attachment is bound to an MCS domain selector. An MCS user may attach through an MCSAP to domains hosted by the MCS provider.
+
+**3.9 MCS user Id:** A short identifier, unique within an MCS domain, that distinguishes between MCS attachments. A user with multiple attachments to the same domain, through the same or different SAPs, has equally many user Ids.
+
+**3.10 control-MCSAP:** A unique MCSAP per MCS provider (distinguished by some local means) to which the MCS Connect and MCS Disconnect primitives are restricted. The MCS user of a Control-MCSAP does not have direct access to data transfer through the MCS Connection end points it contains; this is limited to the MCS provider. It is a local option whether a Control-MCSAP may also contain MCS attachments like ordinary MCSAPs and allow the MCS user to invoke other MCS primitives.
+
+**3.11 MCS channel:** A channel is a domain-wide address. Channels are used for MCS data unit distribution lists. All users who are members of the same channel will receive data sent to that channel.
+
+**3.12 MCS private channel:** A channel with an authorized group of users. Only they may send and receive data over the channel. Attempts by unauthorized users to invoke an MCS primitive involving a private channel as parameter will fail.
+
+**3.13 MCS private channel manager:** An MCS user who convenes a private channel and regulates its authorized user group. If the manager detaches, the private channel is disbanded.
+
+**3.14 version 3 or V3 summit:** The nodes in a domain hierarchy which use MCS protocol version 3 or greater and are either:
+
+- a Top Provider; or
+- have an upward connection path to a version 3 Top Provider that flows only through other version 3 nodes.
+
+## **4 Abbreviations**
+
+This Recommendation uses the following abbreviations:
+
+MCS Multipoint Communication Service
+
+MCSAP MCS Service Access Point
+
+MCSPDU MCS Protocol Data Unit
+
+MCU Multipoint Control Unit (see Recommendation F.710)
+
+SAP Service Access Point
+
+## **5 Conventions**
+
+### **5.1 Primitive parameters conventions**
+
+The primitive parameters defined in this Recommendation will use the following key:
+
+M Parameter is mandatory
+
+C Parameter is conditional
+
+U Parameter is a user option
+
+Blank Parameter is absent
+
+(=) Value of the parameter is identical to the value of the corresponding parameter of the preceding primitive.
+
+### **5.2 Primitive notations**
+
+The primitive services referred to in the text will be in italics.
+
+## **6 Model of MCS**
+
+MCS establishes a multipoint domain over point-to-point MCS connections. Within that multipoint domain, an application client can send data to different members of the domain and have access to tokens for resource contention resolution.
+
+![Diagram of the MCS model showing a hierarchical structure within an MCU. At the top is the MCU. Below it are three MCS user boxes. Each MCS user box contains an MCS box, which in turn contains a dashed box representing multiple channels. These channels are connected via 'MCS connection' lines to a central 'MCS domain' box. The MCS domain box contains two MCS boxes, each with a dashed box above it. Below the MCS domain box are two more MCS user boxes. The entire structure is enclosed in a large rounded rectangle.](d4af765160d04ecef538e5066006dc77_img.jpg)
+
+MCU
+
+MCS user      MCS user      MCS user
+
+MCS      MCS      MCS
+
+MCS connection      MCS connection      MCS connection
+
+MCS connection      MCS connection
+
+MCS domain
+
+MCS user      MCS user
+
+T0818720-94
+
+Diagram of the MCS model showing a hierarchical structure within an MCU. At the top is the MCU. Below it are three MCS user boxes. Each MCS user box contains an MCS box, which in turn contains a dashed box representing multiple channels. These channels are connected via 'MCS connection' lines to a central 'MCS domain' box. The MCS domain box contains two MCS boxes, each with a dashed box above it. Below the MCS domain box are two more MCS user boxes. The entire structure is enclosed in a large rounded rectangle.
+
+**Figure 1/T.122 – MCS model**
+
+The MCS user first establishes an MCS connection between its MCS provider and a remote MCS provider. This connection is bound to a domain to which users can attach. Users at other sites can set up MCS connections to sites already part of the domain and bind them to the same domain.
+
+NOTE – If all communication is to be among applications at one site, connections are not necessary, since only one MCS provider is involved.
+
+Once the domain is established, the MCS user then joins the appropriate channels it requires for receiving data. The use of these channels is application dependent. Tokens are provided for managing the resources available to the client.
+
+## 7 MCS connections and building the domain
+
+For multipoint communication between remote sites to occur, their MCS providers must first be connected and bound to the same domain. A multipoint domain is a hierarchical structure composed of MCS connections that connect MCS providers together. A domain is constructed by binding connections to it.
+
+### 7.1 Establishing connections and binding them to the domain
+
+A Controller sets up an MCS connection through its local MCS provider to a remote site using the *connect provider* service. An MCS connection is a set of transport connections managed as one unit between two MCS providers. The application client communicates with its MCS agent through a Multipoint Communication Service Access Point (MCSAP).
+
+An MCS connection is responsible for delivering MCS data units between MCS providers. An MCS provider can have multiple MCS connections.
+
+![Diagram of the MCS connection phase showing two sites connected via a network. Each site contains an MCS provider and a Controller. The Controller is connected to the MCS provider via a Control-MCSAP interface. The two MCS providers are connected to each other via a network connection.](af7916c89a458fdab6c3f443217388ae_img.jpg)
+
+MCS Connection
+
+T0818730-94
+
+Diagram of the MCS connection phase showing two sites connected via a network. Each site contains an MCS provider and a Controller. The Controller is connected to the MCS provider via a Control-MCSAP interface. The two MCS providers are connected to each other via a network connection.
+
+**Figure 2/T.122 – MCS connection phase**
+
+A controller expecting to receive *connect provider* indications should request a Control-MCSAP. MCS will then know how to direct such indications when they arrive.
+
+![Diagram of a five-site network with multiple MCS connections. The network is hierarchical, with MCS providers at different levels. Some providers are connected to MCUs, some to controllers, and some to application clients. The connections are shown as solid lines between the providers.](ff0952ef692c9d960ce5f6708bcc9711_img.jpg)
+
+T0818740-94
+
+Diagram of a five-site network with multiple MCS connections. The network is hierarchical, with MCS providers at different levels. Some providers are connected to MCUs, some to controllers, and some to application clients. The connections are shown as solid lines between the providers.
+
+NOTE – Some MCS providers have multiple MCS connections and some have multiple attached users. Some MCS providers reside on MCUs, while others reside on terminals.
+
+**Figure 3/T.122 – Five-site network with multiple MCS connections**
+
+The optional user data field of the *connect provider* messages can be used to exchange security information, for example passwords or any other data required by the multipoint application. The *connect provider* request is initiated at one site and approved or rejected by another site. *Connect provider* indications are locally directed to the Control-SAP of the destination provider.
+
+A multipoint domain is organized in a hierarchical structure. The MCS provider at the top of the hierarchy is the Top MCS provider. It is during the domain setup stage that the network hierarchy is defined. Within the *connect provider* request is a field defining whether this connection to be attached is going up to a higher level, or down to a lower one.
+
+NOTE – The domain hierarchical structure is necessary for the allocation of user Ids, for the use of tokens, and for uniformly sequenced data.
+
+The *disconnect provider* service is used to leave a domain and to disconnect transport connections.
+
+### 7.2 Attaching application users to a domain
+
+Application clients become attached to a domain using the *attach user* service. It differs from connecting providers in that it does not require the up/down field for defining domain hierarchy. A SAP is attached to no more than one provider, and is used by no more than one application client at any given time.
+
+An application client automatically receives from MCS in the *attach-user* confirm its own unique user identifier for the domain duration. There is some structural limit to the number of application clients in a domain or channel.
+
+![Diagram illustrating multiple domains and their connections to application clients.](a33da0f14e456f92539ce3e9b7d81f9a_img.jpg)
+
+The diagram illustrates the architecture of multiple domains and their connections to application clients. It is divided into three main sections, each enclosed in a dashed box:
+
+- Top Left:** A dashed box containing an 'MCU controller' connected to an 'MCS provider'. The 'MCS provider' contains two domains: 'Domain B' and 'Domain A'.
+- Top Right:** A dashed box containing an 'MCS provider' with 'Domain A' inside. It is connected to a 'Controller' and an 'Application client'.
+- Bottom Left:** A dashed box containing an 'MCS provider' with 'Domain B' and 'Domain A' inside. It is connected to three 'Application client' boxes and a 'Controller' box.
+- Bottom Right:** A dashed box containing an 'MCS provider' with 'Domain A' inside. It is connected to a 'Controller' and two 'Application client' boxes.
+
+Connections between the sections are as follows:
+
+- A line connects 'Domain A' in the Top Left MCS provider to 'Domain A' in the Top Right MCS provider.
+- A line connects 'Domain B' in the Top Left MCS provider to 'Domain B' in the Bottom Left MCS provider.
+- A line connects 'Domain A' in the Top Left MCS provider to 'Domain A' in the Bottom Left MCS provider.
+- A line connects 'Domain A' in the Bottom Left MCS provider to 'Domain A' in the Bottom Right MCS provider.
+
+T0818750-94
+
+Diagram illustrating multiple domains and their connections to application clients.
+
+NOTE – Application clients can be attached through multiple SAPs to more than one domain.
+
+**Figure 4/T.122 – Multiple domains**
+
+The *detach user* primitive is used by an application client to leave a domain.
+
+### 7.3 MCS-DOMAIN-PARAMETERS
+
+With the exception of protocol version, domain parameters are identical throughout a domain. They are negotiated in the first *connect provider* primitive which sets up the domain. MCS providers joining a domain after the initial two have no say in determining domain parameters. An application client can determine domain parameters by examining the response of a *connect provider* primitive. The domain parameters are defined as follows:
+
+- Maximum number of MCS channels that may be in use simultaneously* – This includes channels that are joined by any user, user Ids that have been assigned, and private channels that have been created.
+- Maximum number of user Ids that may be assigned simultaneously* – This is a sublimit within the constraint of the previous parameter.
+- Maximum number of token Ids that may be grabbed or inhibited simultaneously.*
+
+- d) *Number of data transfer priorities implemented* – An MCS user may still send and receive data with priorities outside the limit. However, such priorities may be treated the same as the lowest priority that is implemented.
+- e) *Enforced throughput* – This parameter instructs MCS providers to enforce a minimum receiving rate at each MCS attachment and over each downward MCS connection. Violators run the risk of being involuntarily detached or disconnected, respectively.
+- f) *Maximum height* – This constrains the height of all MCS providers, in particular the Top MCS Provider.
+- g) *Maximum size of domain MCSPDUs* – Global flow control is based on buffering within an MCS provider. For simplicity, fixed-size buffers are assumed. An MCS provider shall not generate larger MCSPDUs. This constrains the number of parameters that can be packed into a single control operation and suggests where unlimited user data should be segmented.
+- h) *Protocol version* – This is defined in the MCS protocol specification.
+
+## 8 MCS channels
+
+Once the domain setup and user attachment is completed, the last step to be performed before data can be exchanged between all the sites in a multipoint fashion is to join the right combination of interaction channels.
+
+Channels in MCS are domain-wide addresses. When a multipoint domain is established, distribution lists can be declared in the form of multicast channels. Every user of a domain can join a channel to receive MCS data units sent to it, and by joining an appropriate combination of channels, a user can choose to receive messages sent to these channels and ignore messages sent to other channels. Application clients subscribe to and leave the desired channels with the *channel join* and *leave* services.
+
+A mechanism for Quality of Service negotiation on a per channel basis is left for further study.
+
+### 8.1 Multicast channels
+
+Multicast channels are multi-member channels, i.e. channels that can be used to send data to all or a subset of clients of a domain. A multicast channel may represent all active participants in a conference, while another may specify members of a sub-conference. By joining an appropriate combination of channels, a client can elect to receive messages sent to these channels and ignore messages sent to the other channels. For example, all users of a multipoint application may decide to use channel 5 when they wish to receive broadcast data from every member of the domain. Thus every domain member will join channel 5 and send data on this channel when it is to be received by everyone. Another channel may be joined by a subset of domain clients, who will then be able to exchange data on that channel transparent to the rest of domain members.
+
+NOTE – An application client does not have to be joined to a channel in order to send to it, but must be part of it in order to receive data sent to it.
+
+Channel membership is maintained in a distributed fashion, with partial membership information recorded at each level of the hierarchy in a multiple provider domain.
+
+### 8.2 Single-member channels
+
+Single-member channels are normally used as user identifiers (user Ids) which provide user identification and serve as addresses for point-to-point communication within the multipoint domain. Having such a user Id allows other users to be notified when the user detaches. In order for one
+
+member of a domain to send to another transparent to other sites participating in the same domain, he can send data on channel set to the destination user's Id.
+
+### 8.3 Private channels
+
+Both send and receive access to individual multicast channels can be controlled by a private channel mechanism. Any user may convene a private channel with *channel convene* which results in him becoming the private channel manager of an available empty multicast channel. The private channel manager can invite users to join the channel using the *channel admit* service or force a user to leave with the *channel expel* service. Users join and leave private channels using the regular *channel join* and *channel leave* services. The private channel manager discontinues a private channel with the *channel disband* service.
+
+### 8.4 Channel Id numbering
+
+Channel Ids are classified into four types:
+
+- *Static channel Id* – Permanently available, can be joined at will.
+- *User Id* – Can be joined only by the MCS attachment that is assigned the MCS user Id.
+- *Private channel Id* – Can be joined only by the private channel manager and other authorized user Ids that it explicitly admits.
+- *Assigned channel Id* – Created as the result of a *channel join* request for channel Id zero, can be joined at will thereafter, until all joined users leave, at which point it is deleted.
+
+Static channel Ids are numbered 1..1000. All numbers in the static range represent valid channels. Dynamic channel Ids (user Ids, private channel Ids, and assigned channel Ids) are numbered 1001..65535. At any given time, most numbers in the dynamic range will represent non-existent channels (because they were never created or already deleted).
+
+The number of channel Ids in use at once is limited by an MCS domain parameter. Static channel Ids are in use when they are joined by some user. Dynamic channel Ids are in use if they have been created and not yet deleted. MCS primitives (*channel join*, *attach user*, *channel convene*) will fail if they threaten to exceed the limit on number of channel Ids in use.
+
+## 9 MCS data transfer
+
+Once the participating providers have connected and bound to the common domain and users have attached to the common domain and joined the right combination of channels, users are ready to exchange data in a multipoint fashion.
+
+The *send data* and *uniformly sequenced send data* services provide the actual transfer of data. Each send data unit can be delivered (multicast) to multiple sites. Uniform data sequencing, or delivery at each site of identical sequences of data units, is provided with the *uniformly sequenced send data* service.
+
+### 9.1 Simple Send
+
+The *send data* service provides the "one-to-many" communication, which includes point-to-point as a particular case. Sending to a channel set to a remote user Id will provide the actual point-to-point message transmission. Since any sender can send a service data unit to any channel, the many-to-one and many-to-many operations are also supported. Simple send service data units from different senders may arrive in a different sequence at each site, since they are delivered using the most direct route, up and down the tree of MCS providers. Some sequencing occurs even without using the
+
+*uniformly sequenced send data*: The sequencing of service data units sent from one sender on one channel at one priority is maintained identically at all receivers. The sender of a simple send request will NOT receive a send indication if it is a member of the destination channel.
+
+MCS service data units are allowed an unlimited size, however, MCS interface data units within a given system may have a maximum size. It is not desirable to split and reassemble long messages transparently within MCS for two reasons. First, the information may be of near real-time nature and may have to be acted upon immediately. Second, since data units from multiple sources are interleaved at different levels in the network, it would not be possible to reconstruct a message from one source without blocking data units from all the other sources. In the application, however, it is possible to analyse incoming data units to process data units that contain real-time information (such as annotations or pen movements) immediately, while reconstructing a long message received from one source (such as an image or a file).
+
+![Diagram illustrating the process of sending data to all members of a multicast channel. A 'Send data request' arrow points to a central 'MCS' node. From this node, three dashed arrows point to three separate 'MCS' nodes, which are collectively labeled 'Members of multicast channel'. Each of these three 'MCS' nodes has a solid arrow pointing right, labeled 'Send data indication'.](2cde062fd82833415971a8bd1a2cafab_img.jpg)
+
+T0818760-94
+
+Diagram illustrating the process of sending data to all members of a multicast channel. A 'Send data request' arrow points to a central 'MCS' node. From this node, three dashed arrows point to three separate 'MCS' nodes, which are collectively labeled 'Members of multicast channel'. Each of these three 'MCS' nodes has a solid arrow pointing right, labeled 'Send data indication'.
+
+**Figure 5/T.122 – Send data to all the members of a multicast channel**
+
+MCS provides sequenced messaging to multiple destinations, as specified by the membership of the destination channel. To adapt the sending rate to the receiving rate, MCS must combine flow control on the individual connections into a global domain-wide flow control. The throughput of a domain may be limited by its slowest receiver.
+
+### 9.2 Uniformly sequenced data transfer
+
+Uniform sequencing is necessary when data is being sent simultaneously from several sites, but must be received in the same sequence by all receivers. The *uniformly sequenced send data* offers this service. All the *uniformly sequenced send data* requests are routed to the Top MCS provider and from there dispatched in the same order to all the receiving sites, including the sender if it is a member of the destination channel.
+
+### 9.3 Send data with responses (For further study)
+
+This is a simple form of "many-to-one" communication that occurs as an atomic response to a send. When requested by the sender, each receiver must generate a short response. Responses from all receivers are gathered at each level and travel back along the distribution path of the original message. The aggregate response is then delivered to the sender. This form of response can be used either for feedback on delivery of data or as atomic feedback to a simple query. If a more detailed response is needed, any receiver can send a message to the originator, using the source user Id of the received message.
+
+![Diagram showing a multicast Send operation. A central MCS node sends a 'Send data confirm' message to the left. Three other MCS nodes on the right send 'Send data response' messages back to the central MCS node. Dashed lines connect the central MCS to each of the three right-side MCS nodes.](76b0cd79baaedd942af4dc42f2e764b8_img.jpg)
+
+T0818770-94
+
+Diagram showing a multicast Send operation. A central MCS node sends a 'Send data confirm' message to the left. Three other MCS nodes on the right send 'Send data response' messages back to the central MCS node. Dashed lines connect the central MCS to each of the three right-side MCS nodes.
+
+NOTE – A mechanism must be defined to handle receivers that do not generate the requested response within a reasonable time.
+
+**Figure 6/T.122 – Responses requested by a multicast Send**
+
+### 9.4 Unreliable data transfer
+
+By default, all MCS data transfer is fully reliable (i.e. guaranteed delivery). However, there are classes of applications where the occasional loss of data is acceptable and even preferable to the performance loss incurred by recovering lost data with a guaranteed delivery scheme. These applications may choose to use unreliable (i.e. non-guaranteed delivery) data transfer. In this case, received data will be delivered by MCS in the order it was originally sent, but gaps may occur in the application's data stream.
+
+## 10 Token management
+
+Tokens provide a means to implement exclusive access. For example, to ensure in a multipoint application using resources that one and only one site holds a given resource at a given time, a token can be associated with every resource. When a site wishes to use a specific resource, it must ask for its corresponding token, which will be granted only if no one else is holding it.
+
+![Diagram showing token contention resolution. Two sites on the left send 'Token-Grab Request' messages to a central MCS node. The MCS node sends a 'Token-Grab Confirm (accept)' message to the left site and a 'Token-Grab Confirm (reject)' message to the right site.](77464a47f104d0d647b2414591137b64_img.jpg)
+
+T0818780-94
+
+Diagram showing token contention resolution. Two sites on the left send 'Token-Grab Request' messages to a central MCS node. The MCS node sends a 'Token-Grab Confirm (accept)' message to the left site and a 'Token-Grab Confirm (reject)' message to the right site.
+
+**Figure 7/T.122 – Contention resolution: Two sites simultaneously asked for a token, only one site grabbed it**
+
+### 10.1 Exclusive event control and transfer
+
+The *token grab* service allows one user to exclusively hold a given token. The user defines the significance of this token to his application. Other users may use the *token test* service to determine the status of a token at any time and may request the token from the holder with the *token please* service. The token holder may transfer control of a token to another specified user with the *token give* service or return a token to a generally available status with the *token release* service.
+
+### 10.2 Event coordination
+
+A single token may be used to coordinate a multiple user event by using the *token inhibit* service. Users can independently inhibit and release the same token. For example, if it was desired to know when all users have completed reception and processing of a bulk file transfer, all receiving users would inhibit the same token and each individual user would release the token when it had completed the proscribed process. Any user could test the token at will to determine if the token is free which means all users have completed processing.
+
+### 10.3 Token Id Numbering
+
+Token Ids are numbered 1..65535. All numbers in the range are valid token Ids. The number of token Ids in use at once is limited by an MCS domain parameter. Token Ids are in use when they are grabbed or inhibited by some user. MCS primitives (*token grab*, *token inhibit*) will fail if they threaten to exceed the limit on number of token Ids in use.
+
+## 11 Introduction to MCS service primitives
+
+The MCS offers the following service primitives to the application client:
+
+### 11.1 MCS domain management primitives
+
+- MCS-CONNECT-PROVIDER request, indication, response, confirm
+- MCS-DISCONNECT-PROVIDER request, indication
+- MCS-ATTACH-USER request, confirm
+- MCS-DETACH-USER request, indication
+- MCS-DOMAIN-PARAMETERS request, indication, confirm
+
+### 11.2 MCS Channel Management primitives
+
+- MCS-CHANNEL-JOIN request, confirm
+- MCS-CHANNEL-LEAVE request, indication
+- MCS-CHANNEL-CONVENE request, confirm
+- MCS-CHANNEL-DISBAND request, indication
+- MCS-CHANNEL-ADMIT request, indication
+- MCS-CHANNEL-EXPEL request, indication
+
+### 11.3 MCS data transfer primitives
+
+- MCS-SEND-DATA request, indication
+- MCS-UNIFORM-SEND-DATA request, indication
+
+### 11.4 MCS token management primitives
+
+- MCS-TOKEN-GRAB request, confirm
+- MCS-TOKEN-INHIBIT request, confirm
+- MCS-TOKEN-GIVE request, indication, response, confirm
+- MCS-TOKEN-PLEASE request, indication
+- MCS-TOKEN-RELEASE request, confirm
+- MCS-TOKEN-TEST request, confirm
+
+## 12 MCS domain management primitives
+
+### 12.1 MCS-CONNECT-PROVIDER
+
+#### 12.1.1 Function
+
+This primitive establishes an MCS connection through the Control-MCSAP of an MCS provider. It is a local matter how a specific MCS connection end point is identified within the Control-MCSAP. This primitive is confirmed and depends on a response by the MCS user at the Control-MCSAP of the called MCS provider.
+
+The remote site usually passes the indication through a Control-SAP to an application controller. If no control application has attached to the Control-SAP at the remote MCS provider, it is a site configuration decision whether or not all incoming connection requests are to be accepted or rejected.
+
+At the establishment of an MCS connection, two domains that were previously separate are joined into one. Conflicts will arise if the same MCS user Ids are assigned in both. This is resolved by delivering MCS-DETACH-USER indications to selected MCS attachments in the subordinate domain before concluding the MCS Connection. Channel and token Id conflicts are resolved by delivering MCS-CHANNEL-LEAVE and MCS-CHANNEL-DISBAND indications and MCS-DETACH-USER indications to selected MCS attachments in the subordinate domain before concluding the MCS connection.
+
+#### 12.1.2 Types of primitives and their parameters
+
+Table 1/T.122 – MCS-CONNECT-PROVIDER
+
+| Primitive/<br>Parameter                   | Request | Indication | Response | Confirm |
+|-------------------------------------------|---------|------------|----------|---------|
+| Calling address                           | M       | M(=)       |          |         |
+| Calling domain selector                   | M       | M(=)       |          |         |
+| Called address                            | M       | M          |          |         |
+| Called domain selector                    | M       | M          |          |         |
+| Upward/Downward flag                      | M       | M(=)       |          |         |
+| Domain parameters                         | M       | M          | M        | M(=)    |
+| Quality of Service                        | M       | M          | M        | M(=)    |
+| Result                                    |         |            | M        | M(=)    |
+| User data                                 | U       | C(=)       | U        | C(=)    |
+| NOTE – See 5.1 for the key to this table. |         |            |          |         |
+
+- *Calling address, Called address* – Used to establish transport connections between MCS providers.
+- *Calling domain selector, Called domain selector* – Identifies a domain hosted by the respective MCS provider. An MCS connection binds to the calling and called selectors, joining them into the same domain.
+- *Upward/Downward flag* – Designates the called MCS provider as hierarchically superior/subordinate to the calling MCS provider.
+
+- *Domain parameters* – The number of data transfer priorities implemented and, for each, the throughput and transit delay in each direction; also, the number of user Ids, channels and tokens available to MCS users. Data transfer priorities are numbered 0..3 respectively for top, high, medium, and low. If fewer than four priorities are implemented in an MCS domain, lower priority data is transferred at the lowest priority implemented. However, the priority value specified in a data request is indicated unchanged to subsequent receivers. As well, the protocol version, the minimum throughput enforced, the maximum height of all MCS providers, and the maximum size of domain MCSPDUs are all specified as domain parameters.  
+These domain parameters are negotiated between the first two MCS providers that connect to a domain. With the exception of protocol version, MCS providers joining a domain after the initial two have no say in determining domain parameters. See 7.3.
+- *Quality of Service* – Transport layer Quality of Service. Quality of Service can vary from one MCS connection to another.
+- *Result* – Successful, or unsuccessful because of: congested, domain not hierarchical, no such domain, domain parameters unacceptable, unspecified failure, or user-rejected.
+- *User Data* – Of unlimited size. MCS users at the Control-MCSAPs of the MCS providers may use this data to align presentation contexts, to authenticate each other, or for some other purpose.
+
+#### 12.1.3 Sequence of primitives
+
+![Sequence diagram for MCS-CONNECT-PROVIDER (User accept/reject)](c5655e700cc3e9aac7e9f4f07f30264d_img.jpg)
+
+The diagram shows the sequence of primitives for MCS-CONNECT-PROVIDER (User accept/reject). It features two vertical lines labeled "Control MCSAP". An arrow labeled "MCS-CONNECT-PROVIDER request" points from the left towards the first Control MCSAP. A dashed horizontal line connects the two Control MCSAPs. From the second Control MCSAP, an arrow labeled "MCS-CONNECT-PROVIDER indication" points to the right. Below that, an arrow labeled "MCS-CONNECT-PROVIDER response" points from the right back to the second Control MCSAP. Another dashed horizontal line connects the two MCSAPs lower down. Finally, an arrow labeled "MCS-CONNECT-PROVIDER confirm" points from the first Control MCSAP back to the left. The area between the two vertical lines is labeled "MCS" at the bottom. A reference number "T0818790-94" is also present.
+
+Sequence diagram for MCS-CONNECT-PROVIDER (User accept/reject)
+
+**Figure 8/T.122 – MCS-CONNECT-PROVIDER (User accept/reject)**
+
+![Sequence diagram for MCS-CONNECT-PROVIDER (Provider reject)](a3472689858b068ef469213682965325_img.jpg)
+
+The diagram shows the sequence of primitives for MCS-CONNECT-PROVIDER (Provider reject). It features two vertical lines labeled "Control MCSAP". An arrow labeled "MCS-CONNECT-PROVIDER request" points from the left towards the first Control MCSAP. A dashed horizontal line connects the two Control MCSAPs. Below this, another dashed horizontal line connects the two MCSAPs. An arrow labeled "MCS-CONNECT-PROVIDER confirm" points from the first Control MCSAP back to the left. The area between the vertical lines is labeled "MCS" at the bottom. A reference number "T0818800-94" is present.
+
+Sequence diagram for MCS-CONNECT-PROVIDER (Provider reject)
+
+**Figure 9/T.122 – MCS-CONNECT-PROVIDER (Provider reject)**
+
+### 12.2 MCS-DISCONNECT-PROVIDER
+
+#### 12.2.1 Function
+
+This primitive releases an MCS connection that was established previously by invocation of MCS-CONNECT-PROVIDER. It is a local matter how a specific MCS connection end point is identified within the Control-MCSAP of an MCS provider. If user-requested, an indication is delivered through the Control-MCSAP of the MCS provider at the other end of the MCS connection. If provider-initiated, an indication is delivered at both ends.
+
+At the release of an MCS connection, the domain that contained it is split into two. MCS users attached to the Top MCS Provider portion will receive MCS-DETACH-USER indications for those in the opposite portion. If a more severe response is called for, it is the duty of MCS users at the affected Control-MCSAPs to decide. They may inform and direct other MCS users via MCS data transfer or by local means. It is for future study whether the users in the disconnecting bottom portion establish their own domain or not.
+
+#### 12.2.2 Types of primitives and their parameters
+
+**Table 2/T.122 – MCS-DISCONNECT-PROVIDER**
+
+| Primitive/<br>Parameter                   | Request | Indication |
+|-------------------------------------------|---------|------------|
+| Reason                                    |         | M          |
+| NOTE – See 5.1 for the key to this table. |         |            |
+
+- *Reason* – Domain disconnected, domain not hierarchical, domain parameters unacceptable, provider-initiated, unspecified, user-requested.
+
+#### 12.2.3 Sequence of primitives
+
+![Sequence diagram for user-initiated MCS-DISCONNECT-PROVIDER](627c5195eaae3bc7e34cbc4dbdb6f9a8_img.jpg)
+
+The diagram illustrates a user-initiated MCS-DISCONNECT-PROVIDER sequence. It features two vertical lines representing the Control MCSAPs of two entities. A dashed line labeled 'MCS' connects these two entities. An arrow labeled 'MCS-DISCONNECT-PROVIDER request' points from the left Control MCSAP to the right Control MCSAP. From the right Control MCSAP, an arrow labeled 'MCS-DISCONNECT-PROVIDER indication' points to the right. The reference 'T0818810-94' is located at the bottom right.
+
+Sequence diagram for user-initiated MCS-DISCONNECT-PROVIDER
+
+**Figure 10/T.122 – MCS-DISCONNECT-PROVIDER (User-initiated)**
+
+![Sequence diagram for provider-initiated MCS-DISCONNECT-PROVIDER](2834bdd6eb8540277e609decbb924003_img.jpg)
+
+The diagram illustrates a provider-initiated MCS-DISCONNECT-PROVIDER sequence. It features two vertical lines representing the Control MCSAPs of two entities. A wavy line labeled 'MCS' connects these two entities. From the left Control MCSAP, an arrow labeled 'MCS-DISCONNECT-PROVIDER indication' points to the left. From the right Control MCSAP, an arrow labeled 'MCS-DISCONNECT-PROVIDER indication' points to the right. The reference 'T0818820-94' is located at the bottom right.
+
+Sequence diagram for provider-initiated MCS-DISCONNECT-PROVIDER
+
+**Figure 11/T.122 – MCS-DISCONNECT-PROVIDER (Provider-initiated)**
+
+### 12.3 MCS-ATTACH-USER
+
+#### 12.3.1 Function
+
+This primitive creates an MCS attachment through an MCS SAP to a domain hosted by the MCS provider. A result is confirmed to the requester. If the request is accepted, a user Id is assigned.
+
+All subsequent MCS primitives are invoked in the context of some MCS attachment. It is a local matter how a specific MCS attachment is identified within an MCS SAP. Note that domain selector and user Id suffice, but other means may be preferred.
+
+#### 12.3.2 Types of primitives and their parameters
+
+**Table 3/T.122 – MCS-ATTACH-USER**
+
+| Primitive/<br>Parameter                   | Request | Confirm |
+|-------------------------------------------|---------|---------|
+| Domain selector                           | M       |         |
+| Result                                    |         | M       |
+| User Id                                   |         | C       |
+| NOTE – See 5.1 for the key to this table. |         |         |
+
+- *Domain selector* – Identifies a domain hosted by the MCS provider.
+- *Result* – Successful, or unsuccessful because: congested, domain disconnected, no such domain, too many channels, too many users, unspecified failure.
+- *User Id* – Guaranteed unique within the MCS domain. Its value is drawn from the space of MCS channel numbers. To communicate in point-to-point fashion, an MCS user must join the assigned channel as a receiver and must instruct other MCS users to send to it. Channel numbers assigned as user Ids are disjoint from channel numbers representing multicast distribution lists.
+
+#### 12.3.3 Sequence of primitives
+
+![Sequence diagram showing the MCS-ATTACH-USER primitive exchange between an MCS user and a Top MCS provider.](19a59d6b53059ebd27b13c98793f88e0_img.jpg)
+
+The diagram illustrates the sequence of primitives for the MCS-ATTACH-USER operation. It shows two vertical lifelines: 'MCSAP' on the left and 'Top MCS provider' on the right. A solid arrow labeled 'MCS-ATTACH-USER request' points from the MCSAP lifeline to the Top MCS provider lifeline. A dashed arrow labeled 'MCS-ATTACH-USER confirm' points from the Top MCS provider lifeline back to the MCSAP lifeline. Below the Top MCS provider lifeline, the label 'MCS' is present. The reference 'T0818830-94' is located at the bottom right of the diagram.
+
+Sequence diagram showing the MCS-ATTACH-USER primitive exchange between an MCS user and a Top MCS provider.
+
+**Figure 12/T.122 – MCS-ATTACH-USER**
+
+### 12.4 MCS-DETACH-USER
+
+#### 12.4.1 Function
+
+This primitive deletes an MCS attachment that was created previously by invocation of MCS-ATTACH-USER. It is a local matter how a specific MCS attachment is identified within an MCS SAP. This primitive may be requested by a user or initiated by a provider. It delivers an indication at
+
+every other MCS attachment to the same domain. If provider-initiated, an indication is also delivered at the deleted attachment.
+
+#### 12.4.2 Types of primitives and their parameters
+
+**Table 4/T.122 – MCS-DETACH-USER**
+
+| Primitive/<br>Parameter                  | Request | Indication |
+|------------------------------------------|---------|------------|
+| Reason                                   |         | M          |
+| User Id                                  |         | M          |
+| NOTE – See 5.1 for the key to this table |         |            |
+
+- *Reason* – Channel purged, domain disconnected, provider-initiated, token purged (Until there is a TOKEN-RELEASE indication, issuing an MCS-DETACH-USER indication is the only way for the MCS provider to cause a token to be purged. This may be necessary during domain merging.), unspecified, user-requested.
+- *User Id* – Assigned by MCS-ATTACH-USER.
+
+#### 12.4.3 Sequence of primitives
+
+![Sequence diagram for MCS-DETACH-USER (User-initiated).](171115f072e42b379238ed0dd438e9d7_img.jpg)
+
+The diagram shows three vertical lifelines: MCSAP, Top MCS Provider, and Other MCSAPs attached to the domain. A solid arrow labeled 'MCS-DETACH-USER request' originates from the left and points to the MCSAP lifeline. A dashed line connects the MCSAP lifeline to the Top MCS Provider lifeline, with 'MCS' written below it. Another dashed line connects the Top MCS Provider lifeline to the Other MCSAPs lifeline, also with 'MCS' written below it. A solid arrow labeled 'MCS-DETACH-USER indication' originates from the Other MCSAPs lifeline and points to the right. The reference 'T0818840-94' is located at the bottom right.
+
+Sequence diagram for MCS-DETACH-USER (User-initiated).
+
+**Figure 13/T.122 – MCS-DETACH-USER (User-initiated)**
+
+![Sequence diagram for MCS-DETACH-USER (MCS provider-initiated).](19a5f0db57a21a0e82a7f326083e96fd_img.jpg)
+
+The diagram shows three vertical lifelines: MCSAP, Top MCS Provider, and Other MCSAPs attached to the domain. A solid arrow labeled 'MCS-DETACH-USER indication' originates from the left and points to the MCSAP lifeline. A wavy line connects the MCSAP lifeline to the Top MCS Provider lifeline. A dashed line connects the Top MCS Provider lifeline to the Other MCSAPs lifeline, with 'MCS' written below it. A solid arrow labeled 'MCS-DETACH-USER indication' originates from the Other MCSAPs lifeline and points to the right. The reference 'T0818850-94' is located at the bottom right.
+
+Sequence diagram for MCS-DETACH-USER (MCS provider-initiated).
+
+**Figure 14/T.122 – MCS-DETACH-USER (MCS provider-initiated)**
+
+### 12.5 MCS-DOMAIN-PARAMETERS
+
+#### 12.5.1 Function
+
+This primitive provides an MCS user with the parameter values associated with a specified domain. A confirm is received in response to a user-initiated request. An indication is provider-initiated, and is received immediately after successfully attaching to a domain.
+
+#### 12.5.2 Types of primitives and their parameters
+
+**Table 5/T.122 – MCS-DOMAIN-PARAMETERS**
+
+| Primitive/<br>Parameter                   | Request | Indication | Confirm |
+|-------------------------------------------|---------|------------|---------|
+| Domain parameters                         |         | M          | M       |
+| Unreliable data is supported              |         | M          | M       |
+| Maximum user data length                  |         | M          | M       |
+| Maximum admit/expel user Ids              |         | M          | M       |
+| NOTE – See 5.1 for the key to this table. |         |            |         |
+
+- *Domain parameters* – The domain parameter constraints used by a domain.
+- *Unreliable data is supported* – A Boolean value that indicates if unreliable data transfer is supported by this MCS provider for this domain.
+- *Maximum user data length* – The length, in bytes, of the greatest user data field which *MCS-SEND-DATA* request or *MCS-UNIFORM-SEND-DATA* request can send. Fully reliable data larger than this value will be segmented by MCS. Unreliable data larger than this value is not permitted.
+- *Maximum admit/expel user Ids* – The number of user IDs which can be listed in an *MCS-CHANNEL-ADMIT* request or *MCS-CHANNEL-EXPEL* request.
+
+#### 12.5.3 Sequence of primitives
+
+![Sequence diagram showing the request-confirm sequence for MCS-Domain-Parameters. A vertical line represents the MCSAP entity. An arrow labeled 'MCS-Domain-Parameters request' points from the left to the MCSAP line. A second arrow labeled 'MCS-Domain-Parameters confirm' points from the MCSAP line back to the left. The reference T1602380-97 is at the bottom right.](a0739aaf13fa5a632d4faa830f6b2708_img.jpg)
+
+```
+
+sequenceDiagram
+    participant Left
+    participant MCSAP
+    Left->>MCSAP: MCS-Domain-Parameters request
+    MCSAP-->>Left: MCS-Domain-Parameters confirm
+    
+```
+
+T1602380-97
+
+Sequence diagram showing the request-confirm sequence for MCS-Domain-Parameters. A vertical line represents the MCSAP entity. An arrow labeled 'MCS-Domain-Parameters request' points from the left to the MCSAP line. A second arrow labeled 'MCS-Domain-Parameters confirm' points from the MCSAP line back to the left. The reference T1602380-97 is at the bottom right.
+
+**Figure 15/T.122 – MCS-DOMAIN-PARAMETERS request-confirm**
+
+![Sequence diagram showing the indication sequence for MCS-Domain-Parameters. A vertical line represents the MCSAP entity. An arrow labeled 'MCS-Domain-Parameters indication' points from the MCSAP line to the left. The reference T1602390-97 is at the bottom right.](8d325fc12b494e42c9ea7ed2a7f327a6_img.jpg)
+
+```
+
+sequenceDiagram
+    participant Left
+    participant MCSAP
+    MCSAP->>Left: MCS-Domain-Parameters indication
+    
+```
+
+T1602390-97
+
+Sequence diagram showing the indication sequence for MCS-Domain-Parameters. A vertical line represents the MCSAP entity. An arrow labeled 'MCS-Domain-Parameters indication' points from the MCSAP line to the left. The reference T1602390-97 is at the bottom right.
+
+**Figure 16/T.122 – MCS-DOMAIN-PARAMETERS indication**
+
+## 13 MCS channel management primitives
+
+### 13.1 MCS-CHANNEL-JOIN
+
+#### 13.1.1 Function
+
+The MCS-CHANNEL-JOIN service is used by an application client to join an appropriate channel whose use is defined by the application. This is a prerequisite for receiving data sent to the channel.
+
+#### 13.1.2 Types of primitives and their parameters
+
+Table 6/T.122 – MCS-CHANNEL-JOIN
+
+| Primitive/<br>Parameter                   | Request | Confirm |
+|-------------------------------------------|---------|---------|
+| Channel to join                           | M       | C       |
+| Result                                    |         | M       |
+| NOTE – See 5.1 for the key to this table. |         |         |
+
+- *Channel to join* – Identifies the channel to join in the request, and the actual channel joined in the confirm. If channel = 0, then a currently empty multicast channel is to be joined. An empty channel is one to which no user is joined.
+- *Result* – Indicates whether or not joining the channel was allowed. Its value is one of: successful, or unsuccessful because of: other user Id (this channel is a user Id channel already assigned to another user), no such channel, not admitted to the channel, too many channels.
+
+#### 13.1.3 Sequence of primitives
+
+![Sequence diagram for MCS-CHANNEL-JOIN showing a request from MCSAP to Top MCS provider and a confirm response back to MCSAP.](bb3354f497635d15bef873577125c48d_img.jpg)
+
+```
+sequenceDiagram
+    participant MCSAP
+    participant TopMCSprovider as Top MCS provider
+    MCSAP->>TopMCSprovider: MCS-CHANNEL-JOIN request
+    TopMCSprovider-->>MCSAP: MCS-CHANNEL-JOIN confirm
+```
+
+The diagram illustrates the sequence of primitives for the MCS-CHANNEL-JOIN service. It shows two vertical lifelines: 'MCSAP' on the left and 'Top MCS provider' on the right. A solid arrow points from MCSAP to Top MCS provider, labeled 'MCS-CHANNEL-JOIN request'. A dashed arrow points from Top MCS provider back to MCSAP, labeled 'MCS-CHANNEL-JOIN confirm'. Below the lifelines, the text 'MCS' is centered, and 'T0818860-94' is at the bottom right.
+
+Sequence diagram for MCS-CHANNEL-JOIN showing a request from MCSAP to Top MCS provider and a confirm response back to MCSAP.
+
+NOTE – A Join indication primitive issued to the channel manager is for further study.
+
+Figure 17/T.122 – MCS-CHANNEL-JOIN
+
+### 13.2 MCS-CHANNEL-LEAVE
+
+#### 13.2.1 Function
+
+The MCS-CHANNEL-LEAVE service is used by an application client to leave a previously joined channel and thus stop receiving data sent to that channel. The primitive may be user-initiated (request only) or provider-initiated (indication to affected user only).
+
+#### 13.2.2 Types of primitives and their parameters
+
+**Table 7/T.122 – MCS-CHANNEL-LEAVE**
+
+| Primitive/<br>Parameter                   | Request | Indication |
+|-------------------------------------------|---------|------------|
+| Channel to leave                          | M       | M          |
+| Reason                                    |         | M          |
+| NOTE – See 5.1 for the key to this table. |         |            |
+
+- *Channel to leave* – Identifies the channel to leave.
+- *Reason* – Provider-initiated because channel purged.
+
+#### 13.2.3 Sequence of primitives
+
+![Sequence diagram for MCS-CHANNEL-LEAVE (User-initiated)](4cde160bcc69b7b6c81b648dd0e4252e_img.jpg)
+
+The diagram shows a sequence of events between two entities: MCSAP and Top MCS provider. A vertical line represents the MCSAP entity, and another vertical line represents the Top MCS provider entity. A dashed horizontal line connects them, representing the communication channel. An arrow labeled 'MCS-CHANNEL-LEAVE request' points from the MCSAP entity to the Top MCS provider entity. Below the dashed line, the text 'MCS' and 'T0818870-94' are present.
+
+Sequence diagram for MCS-CHANNEL-LEAVE (User-initiated)
+
+**Figure 18/T.122 – MCS-CHANNEL-LEAVE (User-initiated)**
+
+![Sequence diagram for MCS-CHANNEL-LEAVE (MCS provider-initiated)](e29665b8abcea967ef289c6aff07ae4c_img.jpg)
+
+The diagram shows a sequence of events between two entities: MCSAP and Top MCS provider. A vertical line represents the MCSAP entity, and another vertical line represents the Top MCS provider entity. A dashed horizontal line connects them, representing the communication channel. An arrow labeled 'MCS-CHANNEL-LEAVE indication' points from the Top MCS provider entity to the MCSAP entity. Below the dashed line, the text 'MCS' and 'T0818880-94' are present.
+
+Sequence diagram for MCS-CHANNEL-LEAVE (MCS provider-initiated)
+
+**Figure 19/T.122 – MCS-CHANNEL-LEAVE (MCS provider-initiated)**
+
+### 13.3 MCS-CHANNEL-CONVENE
+
+#### 13.3.1 Function
+
+This primitive allocates a new private channel with the requesting user as manager. A result is confirmed; if the request is accepted, a channel number is assigned. The authorized user group initially consists of the manager alone. It is guaranteed that no users are joined to the channel.
+
+#### 13.3.2 Types of primitives and their parameters
+
+**Table 8/T.122 – MCS-CHANNEL-CONVENE**
+
+| Primitive/<br>Parameter                   | Request | Confirm |
+|-------------------------------------------|---------|---------|
+| Result                                    |         | M       |
+| Channel                                   |         | C       |
+| NOTE – See 5.1 for the key to this table. |         |         |
+
+- *Result* – Successful, or unsuccessful because of: too many channels.
+- *Channel* – A private channel number, protected from unauthorized users.
+
+#### 13.3.3 Sequence of primitives
+
+![Sequence diagram showing the interaction between Manager MCSAP and Top MCS provider for MCS-CHANNEL-CONVENE.](759c7d62402f0b4651ddce292be5bdef_img.jpg)
+
+The diagram illustrates the sequence of primitives for MCS-CHANNEL-CONVENE. It shows two vertical lifelines: 'Manager MCSAP' and 'Top MCS provider'. A message arrow labeled 'MCS-CHANNEL-CONVENE request' points from the Manager MCSAP lifeline to the Top MCS provider lifeline. A return message arrow labeled 'MCS-CHANNEL-CONVENE confirm' points from the Top MCS provider lifeline back to the Manager MCSAP lifeline. The diagram is identified by the number T0818890-94.
+
+Sequence diagram showing the interaction between Manager MCSAP and Top MCS provider for MCS-CHANNEL-CONVENE.
+
+**Figure 20/T.122 – MCS-CHANNEL-CONVENE**
+
+### 13.4 MCS-CHANNEL-DISBAND
+
+#### 13.4.1 Function
+
+This primitive deallocates a private channel that was allocated previously by invocation of MCS-CHANNEL-CONVENE. This primitive may be requested by or indicated to the channel's manager. It causes an MCS-CHANNEL-EXPEL indication to be delivered to all members remaining in the authorized user group. Thereafter, the channel number may be recycled for private or public use.
+
+#### 13.4.2 Types of primitives and their parameters
+
+**Table 9/T.122 – MCS-CHANNEL-DISBAND**
+
+| Primitive/<br>Parameter                   | Request | Indication |
+|-------------------------------------------|---------|------------|
+| Channel                                   | M       | M          |
+| Reason                                    |         | M          |
+| NOTE – See 5.1 for the key to this table. |         |            |
+
+- *Channel* – A private channel number.
+- *Reason* – Provider-initiated because channel purged.
+
+#### 13.4.3 Sequence of primitives
+
+![Sequence diagram for MCS-CHANNEL-DISBAND (Channel manager-initiated). The diagram shows three lifelines: Manager MCSAP, Top MCS provider, and Other MCSAPs admitted to the Channel. A dashed line labeled 'MCS' connects the Manager MCSAP and Top MCS provider. Another dashed line labeled 'MCS' connects the Top MCS provider and Other MCSAPs. An arrow labeled 'MCS-CHANNEL-DISBAND request' points from the Manager MCSAP to the Top MCS provider. An arrow labeled 'MCS-CHANNEL-EXPEL indication' points from the Other MCSAPs to the Top MCS provider. The reference 'T0818900-94' is at the bottom right.](2bacc162a73d75c43a7f90715832bd13_img.jpg)
+
+Sequence diagram for MCS-CHANNEL-DISBAND (Channel manager-initiated). The diagram shows three lifelines: Manager MCSAP, Top MCS provider, and Other MCSAPs admitted to the Channel. A dashed line labeled 'MCS' connects the Manager MCSAP and Top MCS provider. Another dashed line labeled 'MCS' connects the Top MCS provider and Other MCSAPs. An arrow labeled 'MCS-CHANNEL-DISBAND request' points from the Manager MCSAP to the Top MCS provider. An arrow labeled 'MCS-CHANNEL-EXPEL indication' points from the Other MCSAPs to the Top MCS provider. The reference 'T0818900-94' is at the bottom right.
+
+**Figure 21/T.122 – MCS-CHANNEL-DISBAND (Channel manager-initiated)**
+
+![Sequence diagram for MCS-CHANNEL-DISBAND (MCS provider-initiated). The diagram shows three lifelines: Manager MCSAP, Top MCS provider, and Other MCSAPs admitted to the Channel. A dashed line labeled 'MCS' connects the Manager MCSAP and Top MCS provider. Another dashed line labeled 'MCS' connects the Top MCS provider and Other MCSAPs. An arrow labeled 'MCS-CHANNEL-DISBAND indication' points from the Top MCS provider to the Manager MCSAP. An arrow labeled 'MCS-CHANNEL-EXPEL indication' points from the Other MCSAPs to the Top MCS provider. The reference 'T0818910-94' is at the bottom right.](28d75f39a24203712ee907b32cf0bbe5_img.jpg)
+
+Sequence diagram for MCS-CHANNEL-DISBAND (MCS provider-initiated). The diagram shows three lifelines: Manager MCSAP, Top MCS provider, and Other MCSAPs admitted to the Channel. A dashed line labeled 'MCS' connects the Manager MCSAP and Top MCS provider. Another dashed line labeled 'MCS' connects the Top MCS provider and Other MCSAPs. An arrow labeled 'MCS-CHANNEL-DISBAND indication' points from the Top MCS provider to the Manager MCSAP. An arrow labeled 'MCS-CHANNEL-EXPEL indication' points from the Other MCSAPs to the Top MCS provider. The reference 'T0818910-94' is at the bottom right.
+
+**Figure 22/T.122 – MCS-CHANNEL-DISBAND (MCS provider-initiated)**
+
+### 13.5 MCS-CHANNEL-ADMIT
+
+#### 13.5.1 Function
+
+This primitive enlarges the authorized user group of a private channel at the request of its manager. An indication is delivered to the MCS user added. That user may thereafter send data on the channel or join it as a receiver or invoke other MCS primitives.
+
+#### 13.5.2 Types of primitives and their parameters
+
+**Table 10/T.122 – MCS-CHANNEL-ADMIT**
+
+| Primitive/<br>Parameter                   | Request | Indication |
+|-------------------------------------------|---------|------------|
+| Channel                                   | M       | M(=)       |
+| Manager user Id                           |         | M          |
+| List of user Ids                          | M       |            |
+| NOTE – See 5.1 for the key to this table. |         |            |
+
+- *Channel* – A private channel number.
+- *Manager User Id* – The user Id of the channel manager.
+- *List of User Ids* – The list of users to be added to the authorized group.
+
+#### 13.5.3 Sequence of primitives
+
+![Sequence diagram for MCS-CHANNEL-ADMIT showing a request from Manager MCSAP to Top MCS provider and an indication from Top MCS provider to MCSAP.](5414f65867392f05ba0063b208eeb5e1_img.jpg)
+
+```
+
+sequenceDiagram
+    participant Manager as Manager MCSAP
+    participant TopMCS as Top MCS provider
+    participant MCSAP as MCSAP
+    Manager->>TopMCS: MCS-CHANNEL-ADMIT request
+    TopMCS->>MCSAP: MCS-CHANNEL-ADMIT indication
+    
+```
+
+The diagram shows three vertical lifelines: Manager MCSAP, Top MCS provider, and MCSAP. A solid arrow labeled 'MCS-CHANNEL-ADMIT request' points from Manager MCSAP to Top MCS provider. A dashed line connects Top MCS provider to MCSAP. A solid arrow labeled 'MCS-CHANNEL-ADMIT indication' points from Top MCS provider to MCSAP. The text 'T0818920-94' is at the bottom right.
+
+Sequence diagram for MCS-CHANNEL-ADMIT showing a request from Manager MCSAP to Top MCS provider and an indication from Top MCS provider to MCSAP.
+
+**Figure 23/T.122 – MCS-CHANNEL-ADMIT**
+
+### 13.6 MCS-CHANNEL-EXPEL
+
+#### 13.6.1 Function
+
+This primitive shrinks the authorized user group of a private channel. It may be requested by the channel manager or initiated by the MCS provider. An indication is delivered to the MCS user deleted. If the deleted user is joined to the channel as a receiver the expel also has the effect of a channel leave indication.
+
+#### 13.6.2 Types of primitives and their parameters
+
+**Table 11/T.122 – MCS-CHANNEL-EXPEL**
+
+| Primitive/<br>Parameter                   | Request | Indication |
+|-------------------------------------------|---------|------------|
+| Channel                                   | M       | M (=)      |
+| List of user Ids                          | M       |            |
+| Reason                                    |         | M          |
+| NOTE – See 5.1 for the key to this table. |         |            |
+
+- *Channel* – A private channel number.
+- *List of user Ids* – The list of users to be expelled from the authorized group.
+- *Reason* – Channel disbanded, channel purged, user-requested.
+
+#### 13.6.3 Sequence of primitives
+
+![Sequence diagram for MCS-CHANNEL-EXPEL showing a request from Manager MCSAP to Top MCS provider and an indication from Top MCS provider to MCSAP.](a7585024ebe2bba8ac0757150a12759a_img.jpg)
+
+```
+
+sequenceDiagram
+    participant Manager as Manager MCSAP
+    participant TopMCS as Top MCS provider
+    participant MCSAP as MCSAP
+    Manager->>TopMCS: MCS-CHANNEL-EXPEL request
+    TopMCS->>MCSAP: MCS-CHANNEL-EXPEL indication
+    
+```
+
+The diagram shows three vertical lifelines: Manager MCSAP, Top MCS provider, and MCSAP. A solid arrow labeled 'MCS-CHANNEL-EXPEL request' points from Manager MCSAP to Top MCS provider. A dashed line connects Top MCS provider to MCSAP. A solid arrow labeled 'MCS-CHANNEL-EXPEL indication' points from Top MCS provider to MCSAP. The text 'T0818930-94' is at the bottom right.
+
+Sequence diagram for MCS-CHANNEL-EXPEL showing a request from Manager MCSAP to Top MCS provider and an indication from Top MCS provider to MCSAP.
+
+**Figure 24/T.122 – MCS-CHANNEL-EXPEL**
+
+## 14 MCS data transfer primitives
+
+### 14.1 MCS-SEND-DATA
+
+#### 14.1.1 Function
+
+The MCS-SEND-DATA service is used to transmit data to other members of a domain.
+
+If the sender is a member of the destination channel, it will not receive its own data indications. However, it will receive data indications from other sources addressed to that channel.
+
+If multiple clients send data to the same channel, different receivers may receive data from different senders in a different order. If uniform sequencing is needed for some data, all senders should send that data using the MCS-UNIFORMLY-SEQUENCED-SEND-DATA services described later.
+
+Fully reliable data from each sender sent at the same priority on the same channel arrive at a given receiver in the same order as it was sent but may have other sender data interleaved differently. Unreliable data will be similarly ordered at the receiver, but there may be data packets missing from a sender's data stream.
+
+#### 14.1.2 Types of primitives and their parameters
+
+**Table 12/T.122 – MCS-SEND-DATA**
+
+| Primitive/<br>Parameter                   | Request | Indication |
+|-------------------------------------------|---------|------------|
+| Reliability                               | M       | M(=)       |
+| Priority                                  | M       | M(=)       |
+| Channel Id                                | M       | M(=)       |
+| Sender user Id                            |         | M          |
+| Segmentation                              |         | M          |
+| Total data size                           |         | C          |
+| Data                                      | M       | M(=)       |
+| NOTE – See 5.1 for the key to this table. |         |            |
+
+- *Reliability* – Indicates whether the data should be sent, or was received, via fully reliable or unreliable transport.
+- *Priority* – The number of priority levels implemented is a Quality of Service parameter of the domain.
+- *Channel Id* – Indicates which channel to use to send the data.
+- *Sender user Id* – Is set by the sender's MCS provider.
+- *Segmentation* – The segmentation flags *begin* and *end* permit fully reliable data units to be reassembled by the user. These flags shall be interpreted in the context of MCS-SEND-DATA indications arriving from the same user over the same channel and at the same priority. A stream of fragments to be reassembled may be interleaved with other MCS primitives and data from other users over other channels at other priorities. Unreliable data units will not be segmented by MCS and will not require reassembly by the user.
+- *Total data size* – For a given MCS-SEND-DATA indication, if the *begin* segmentation flag is true, and the *end* flag is false, the total size of the segmented user data will be provided.
+
+This parameter will only be present if both the source and sink nodes are members of the V3 summit.
+
+- *Data* – If *Reliability* is fully reliable, the data can be of unlimited size. If *Reliability* is unreliable, the data size may not exceed the *Maximum User Data Length* returned by the MCS-Get-Domain-Parameters primitive. See 12.5.
+
+#### 14.1.3 Sequence of primitives
+
+![Sequence diagram showing the flow of MCS-SEND-DATA. An arrow labeled 'MCS-SEND-DATA request' points to a vertical line labeled 'MCSAP'. A dashed line labeled 'MCS' connects this line to another vertical line labeled 'Other MCSAPs joined to the channel'. An arrow labeled 'MCS-SEND-DATA indication' points from the second line to the right. The reference 'T0818940-94' is at the bottom right.](e05b36c0d46549e681ce6581422c66b2_img.jpg)
+
+```
+
+sequenceDiagram
+    participant Request as MCS-SEND-DATA request
+    participant MCSAP as MCSAP
+    participant MCS as MCS
+    participant OtherMCSAPs as Other MCSAPs joined to the channel
+    participant Indication as MCS-SEND-DATA indication
+
+    Request->>MCSAP
+    MCSAP-->>OtherMCSAPs: MCS
+    OtherMCSAPs->>Indication
+    
+```
+
+T0818940-94
+
+Sequence diagram showing the flow of MCS-SEND-DATA. An arrow labeled 'MCS-SEND-DATA request' points to a vertical line labeled 'MCSAP'. A dashed line labeled 'MCS' connects this line to another vertical line labeled 'Other MCSAPs joined to the channel'. An arrow labeled 'MCS-SEND-DATA indication' points from the second line to the right. The reference 'T0818940-94' is at the bottom right.
+
+**Figure 25/T.122 – MCS-SEND-DATA**
+
+### 14.2 MCS-UNIFORMLY-SEQUENCED-SEND-DATA
+
+#### 14.2.1 Function
+
+The MCS-UNIFORMLY-SEQUENCED-SEND-DATA service is used to transmit data to other members of a domain in a uniformly sequenced manner, i.e. the data will be received in the same sequence by all members of the destination channel. The different data units from the domain clients will be forwarded to the Top MCS Provider, which will send them back to all clients in the same sequence. Note that if unreliable transmission is selected, data packets may be missing from the uniform data stream, and that these missing packets may differ from node to node.
+
+Uniform sequencing of data is guaranteed only for data of the same priority on the same channel.
+
+If the sender is a member of the destination channel, it will receive its own data, in the proper sequence. Therefore, it is provided with the same ordered data stream as other members of the channel.
+
+#### 14.2.2 Types of primitives and their parameters
+
+**Table 13/T.122 – MCS-UNIFORM-SEND-DATA**
+
+| Primitive/<br>Parameter                   | Request | Indication |
+|-------------------------------------------|---------|------------|
+| Reliability                               | M       | M(=)       |
+| Priority                                  | M       | M(=)       |
+| Channel Id                                | M       | M(=)       |
+| Sender user Id                            |         | M          |
+| Segmentation                              |         | M          |
+| Total Data Size                           |         | C          |
+| Data                                      | M       | M(=)       |
+| NOTE – See 5.1 for the key to this table. |         |            |
+
+- *Reliability* – Indicates whether the data should be sent, or was received, via fully reliable or unreliable transport.
+- *Priority* – The number of priority levels implemented is a Quality of Service parameter of the domain.
+- *Channel Id* – Indicates which channel to use to send the data.
+- *Sender user Id* – Is set by the sender's MCS provider.
+- *Segmentation* – The segmentation flags *begin* and *end* permit fully reliable data units to be reassembled by the user. These flags shall be interpreted in the context of MCS-UNIFORM-SEND-DATA indications arriving from the same user over the same channel and at the same priority. A stream of fragments to be reassembled may be interleaved with other MCS primitives and data from other users over other channels at other priorities. Unreliable data units will not be segmented by MCS and will not require reassembly by the user.
+- *Total data size* – For a given MCS-UNIFORM-SEND-DATA indication, if the *begin* segmentation flag is true, and the *end* flag is false, the total size of the segmented user data will be provided. This parameter will only be present if both the source and sink nodes are members of the V3 summit.
+- *Data* – If *Reliability* is fully reliable, the data can be of unlimited size. If *Reliability* is unreliable, the data size may not exceed the *Maximum User Data Length* returned by the *MCS-GET-DOMAIN-PARAMETERS* primitive. See 12.5.
+
+#### 14.2.3 Sequence of primitives
+
+![Sequence diagram showing the flow of MCS-UNIFORM-SEND-DATA request and indication through various components.](318886a86a1dcc59e1fc83db6f157c60_img.jpg)
+
+The diagram illustrates the sequence of primitives for MCS-UNIFORM-SEND-DATA. It shows a horizontal timeline with four vertical lines representing different components: MCSAP, Top MCS provider, Other MCSAPs joined to the Channel, and MCS. The sequence of events is as follows:
+ 
+
+- An arrow labeled "MCS-UNIFORM-SEND-DATA request" points from the left to the MCSAP line.
+- An arrow labeled "MCS-UNIFORM-SEND-DATA indication" points from the MCSAP line to the left.
+- A dashed arrow points from the MCSAP line to the Top MCS provider line.
+- A dashed arrow points from the Top MCS provider line to the Other MCSAPs joined to the Channel line.
+- A solid arrow labeled "MCS-UNIFORM-SEND-DATA indication" points from the Other MCSAPs joined to the Channel line to the right.
+
+ The label "T0818950-94" is located at the bottom right of the diagram.
+
+Sequence diagram showing the flow of MCS-UNIFORM-SEND-DATA request and indication through various components.
+
+**Figure 26/T.122 – MCS-UNIFORMLY-SEQUENCED-SEND-DATA**
+
+## 15 MCS token management primitives
+
+### 15.1 MCS-TOKEN-GRAB
+
+#### 15.1.1 Function
+
+The MCS-TOKEN-GRAB service is used to take exclusive control of a specific token.
+
+MCS-TOKEN-GRAB will succeed if the requester is the sole inhibitor of the token.
+
+#### 15.1.2 Types of primitives and their parameters
+
+Table 14/T.122 – MCS-TOKEN-GRAB
+
+| Primitive/<br>Parameter                   | Request | Confirm |
+|-------------------------------------------|---------|---------|
+| Token identifier                          | M       | M(=)    |
+| Result                                    |         | M       |
+| NOTE – See 5.1 for the key to this table. |         |         |
+
+- *Token Id* – Identifies the token the client wishes to grab.
+- *Result* – Indicates whether or not the token grab was allowed. Its value is one of: successful, or unsuccessful because: token not available, too many tokens.
+
+#### 15.1.3 Sequence of primitives
+
+![Sequence diagram for MCS-TOKEN-GRAB showing a request from MCSAP to Top MCS provider and a confirm response.](a4b963a07cc368283154762c4b156fe7_img.jpg)
+
+```
+sequenceDiagram
+    participant MCSAP
+    participant TopMCSprovider as Top MCS provider
+    MCSAP->>TopMCSprovider: MCS-TOKEN-GRAB request
+    TopMCSprovider-->>MCSAP: MCS-TOKEN-GRAB confirm
+```
+
+The diagram illustrates the sequence of primitives for the MCS-TOKEN-GRAB service. It shows two entities: MCSAP and Top MCS provider. A solid arrow labeled 'MCS-TOKEN-GRAB request' points from MCSAP to Top MCS provider. A dashed arrow labeled 'MCS-TOKEN-GRAB confirm' points from Top MCS provider back to MCSAP. The diagram is identified by the number T0818960-94.
+
+Sequence diagram for MCS-TOKEN-GRAB showing a request from MCSAP to Top MCS provider and a confirm response.
+
+Figure 27/T.122 – MCS-TOKEN-GRAB
+
+### 15.2 MCS-TOKEN-INHIBIT
+
+#### 15.2.1 Function
+
+The MCS-TOKEN-INHIBIT service is used to take non-exclusive control of a specific token. It is used to prevent someone else from exclusively grabbing the token. Several users could inhibit a token at the same time.
+
+MCS-TOKEN-INHIBIT will succeed if the requester has grabbed the token. The result will be that the token is no longer grabbed and is inhibited instead. Thereafter it may be inhibited by other users too.
+
+#### 15.2.2 Types of primitives and their parameters
+
+Table 15/T.122 – MCS-TOKEN-INHIBIT
+
+| Primitive/<br>Parameter                   | Request | Confirm |
+|-------------------------------------------|---------|---------|
+| Token identifier                          | M       | M(=)    |
+| Result                                    |         | M       |
+| NOTE – See 5.1 for the key to this table. |         |         |
+
+- *Token Id* – Identifies the token the client wishes to inhibit.
+
+- *Result* – Indicates whether or not the token inhibit was allowed. Its value is one of: successful, or unsuccessful because: token not available, too many tokens.
+
+#### 15.2.3 Sequence of primitives
+
+![Sequence diagram for MCS-TOKEN-INHIBIT showing the interaction between MCSAP and Top MCS provider.](dcc2d5a5b39f780e7a224bb01ba1ef6e_img.jpg)
+
+```
+
+sequenceDiagram
+    participant MCSAP
+    participant TopMCSProvider as Top MCS provider
+    MCSAP->>TopMCSProvider: MCS-TOKEN-INHIBIT request
+    TopMCSProvider-->>MCSAP: MCS-TOKEN-INHIBIT confirm
+    Note over MCSAP, TopMCSProvider: MCS T0818970-94
+  
+```
+
+The diagram illustrates the sequence of primitives for MCS-TOKEN-INHIBIT. It shows two entities: MCSAP and Top MCS provider. MCSAP sends an 'MCS-TOKEN-INHIBIT request' to the Top MCS provider. The Top MCS provider then sends an 'MCS-TOKEN-INHIBIT confirm' back to MCSAP. A dashed line connects the two entities, and the text 'MCS T0818970-94' is located below the dashed line.
+
+Sequence diagram for MCS-TOKEN-INHIBIT showing the interaction between MCSAP and Top MCS provider.
+
+**Figure 28/T.122 – MCS-TOKEN-INHIBIT**
+
+### 15.3 MCS-TOKEN-GIVE
+
+#### 15.3.1 Function
+
+The MCS-TOKEN-GIVE service is used by an application client to surrender a token to another application client.
+
+MCS-TOKEN-GIVE will fail if the requester has not grabbed the specified token.
+
+A token being passed between two users and whose possession is not yet resolved will appear to any user requesting MCS-TOKEN-TEST to be grabbed by some other user and not held by the requester. MCS-TOKEN-GRAB and MCS-TOKEN-INHIBIT will fail during the interval, even if requested by one of the two users involved. MCS-TOKEN-RELEASE requested by the giver will succeed, with the result that the token is released if the offer to the recipient is ultimately rejected. MCS-TOKEN-RELEASE by the recipient will have no effect, just like the attempted release of any other token that the requester does not yet possess. During the interval that a token is being passed, any MCS-TOKEN-PLEASE indications that are generated will be delivered to both users involved.
+
+It is possible for the ownership of a passed token to be resolved before an MCS-TOKEN-GIVE response or confirm is issued, i.e. deletion of either the giver or recipient will leave the survivor in sole possession as grabber of the token. At this point, the special effects explained above cease to apply.
+
+#### 15.3.2 Types of primitives and their parameters
+
+**Table 16/T.122 – MCS-TOKEN-GIVE**
+
+| Primitive/<br>Parameter                   | Request | Indication | Response | Confirm |
+|-------------------------------------------|---------|------------|----------|---------|
+| User Id giving token                      |         | M          |          |         |
+| User Id to receive token                  | M       |            |          |         |
+| Token Id                                  | M       | M(=)       |          | M(=)    |
+| Result                                    |         |            | M        | M(=)    |
+| NOTE – See 5.1 for the key to this table. |         |            |          |         |
+
+- *User Id giving token* – The user Id giving the token. It is set by the user's MCS provider.
+- *User Id to receive token* – The user Id to be receiving the token.
+- *Token identifier* – Is the token to be given.
+- *Result* – Indicates whether or not the token give was successful. Its value is one of: successful, or unsuccessful because: domain merging, no such user, token not possessed, user rejected.
+
+#### 15.3.3 Sequence of primitives
+
+![Sequence diagram for MCS-TOKEN-GIVE showing interactions between MCSAP, Top MCS provider, and MCS.](1142ba0197b158bb198186fe8baccc32_img.jpg)
+
+```
+
+sequenceDiagram
+    participant MCSAP1 as MCSAP
+    participant TopMCS as Top MCS provider
+    participant MCS1 as MCS
+    participant MCS2 as MCS
+    participant MCSAP2 as MCSAP
+
+    MCSAP1->>MCS1: MCS-TOKEN-GIVE request
+    MCS1-->>TopMCS: 
+    TopMCS-->>MCS2: 
+    MCS2-->>MCSAP2: MCS-TOKEN-GIVE indication
+    MCSAP2->>MCS1: MCS-TOKEN-GIVE response
+    MCS1-->>MCSAP1: MCS-TOKEN-GIVE confirm
+  
+```
+
+The diagram illustrates the sequence of primitives for the MCS-TOKEN-GIVE service. It involves three main entities: MCSAP (Application Client), Top MCS provider, and MCS (MCS Provider). The sequence starts with an MCS-TOKEN-GIVE request from MCSAP to MCS. This request is then forwarded to the Top MCS provider. The Top MCS provider then sends an indication back to MCS. MCS then sends a response back to MCSAP. Finally, MCSAP sends a confirm message back to MCS. The diagram also includes a reference to T0818980-94.
+
+Sequence diagram for MCS-TOKEN-GIVE showing interactions between MCSAP, Top MCS provider, and MCS.
+
+Figure 29/T.122 – MCS-TOKEN-GIVE
+
+### 15.4 MCS-TOKEN-PLEASE
+
+#### 15.4.1 Function
+
+The MCS-TOKEN-PLEASE service is used by an application client to request a token from the current possessor(s) of the token. A token may be inhibited by several users, or it may be grabbed by one user. In any case, MCS-TOKEN-PLEASE indications are delivered to each user possessing the token.
+
+#### 15.4.2 Types of primitives and their parameters
+
+Table 17/T.122 – MCS-TOKEN-PLEASE
+
+| Primitive/<br>Parameter                   | Request | Indication |
+|-------------------------------------------|---------|------------|
+| User Id<br>requesting token               |         | M          |
+| Token Id                                  | M       | M(=)       |
+| NOTE – See 5.1 for the key to this table. |         |            |
+
+- *User Id requesting token* – Is the user Id requesting the token. It is set by the user's MCS provider.
+- *Token Id* – Is the token being requested.
+
+#### 15.4.3 Sequence of primitives
+
+![Sequence diagram for MCS-TOKEN-PLEASE](ed48e24e36ea0501953177401c900f86_img.jpg)
+
+Sequence diagram illustrating the MCS-TOKEN-PLEASE sequence:
+
+- MCS-TOKEN-PLEASE request** is sent from the **MCSAP** to the **Top MCS provider**.
+- The **Top MCS provider** is the **MCSAP of current possessor/inhibitor(s) of the token**.
+- The **Top MCS provider** sends an **MCS-TOKEN-PLEASE indication** to the **MCS**.
+
+Diagram labels: MCSAP, Top MCS provider, MCSAP of current possessor/inhibitor(s) of the token, MCS, MCS-TOKEN-PLEASE request, MCS-TOKEN-PLEASE indication, T0818990-94.
+
+Sequence diagram for MCS-TOKEN-PLEASE
+
+**Figure 30/T.122 – MCS-TOKEN-PLEASE**
+
+Response and Confirm primitives are left out for further study.
+
+### 15.5 MCS-TOKEN-RELEASE
+
+#### 15.5.1 Function
+
+The MCS-TOKEN-RELEASE service is used to free up a previously grabbed/inhibited token.
+
+#### 15.5.2 Types of primitives and their parameters
+
+**Table 18/T.122 – MCS-TOKEN-RELEASE**
+
+| Primitive/<br>Parameter                   | Request | Confirm |
+|-------------------------------------------|---------|---------|
+| Token Identifier                          | M       | M(=)    |
+| Result                                    |         | M       |
+| NOTE – See 5.1 for the key to this table. |         |         |
+
+- *Token Id* – The token to release.
+- *Result* – Successful, or unsuccessful because: token not possessed.
+
+#### 15.5.3 Sequence of primitives
+
+![Sequence diagram for MCS-TOKEN-RELEASE (MCS user-initiated)](4c731b7bb6a5851992b8b7440b4e9356_img.jpg)
+
+Sequence diagram illustrating the MCS-TOKEN-RELEASE (MCS user-initiated) sequence:
+
+- MCS-TOKEN-RELEASE request** is sent from the **MCSAP** to the **Top MCS provider**.
+- The **Top MCS provider** sends an **MCS-TOKEN-RELEASE confirm** to the **MCS**.
+
+Diagram labels: MCSAP, Top MCS provider, MCS, MCS-TOKEN-RELEASE request, MCS-TOKEN-RELEASE confirm, T0819000-94.
+
+Sequence diagram for MCS-TOKEN-RELEASE (MCS user-initiated)
+
+**Figure 31/T.122 – MCS-TOKEN-RELEASE (MCS user-initiated)**
+
+### 15.6 MCS-TOKEN-TEST
+
+#### 15.6.1 Function
+
+The MCS-TOKEN-TEST service is used to check whether a token is available.
+
+#### 15.6.2 Types of primitives and their parameters
+
+**Table 19/T.122 – MCS-TOKEN-TEST**
+
+| Primitive/<br>Parameter                   | Request | Confirm |
+|-------------------------------------------|---------|---------|
+| Token identifier                          | M       | M(=)    |
+| Token status                              |         | M       |
+| NOTE – See 5.1 for the key to this table. |         |         |
+
+- *Token Id* – Is the token to be tested for its status.
+- *Token status* – Is one of free, grabbed, grabbed and held by the testing user, inhibited, inhibited and inhibited by the testing user, token does not exist.
+
+#### 15.6.3 Sequence of primitives
+
+![Sequence diagram for MCS-TOKEN-TEST showing a request from MCSAP to Top MCS provider and a confirm response back to MCSAP.](d8698aacaeead6dfed9a1e448670a2e4_img.jpg)
+
+```
+sequenceDiagram
+    participant MCSAP
+    participant TopMCSprovider as Top MCS provider
+    MCSAP->>TopMCSprovider: MCS-TOKEN-TEST request
+    TopMCSprovider-->>MCSAP: MCS-TOKEN-TEST confirm
+```
+
+The diagram illustrates the sequence of primitives for the MCS-TOKEN-TEST service. It shows two vertical lifelines: 'MCSAP' and 'Top MCS provider'. A solid arrow labeled 'MCS-TOKEN-TEST request' points from MCSAP to Top MCS provider. A dashed arrow labeled 'MCS-TOKEN-TEST confirm' points from Top MCS provider back to MCSAP. Below the lifelines, the text 'MCS' and the reference 'T0819010-94' are present.
+
+Sequence diagram for MCS-TOKEN-TEST showing a request from MCSAP to Top MCS provider and a confirm response back to MCSAP.
+
+**Figure 32/T.122 – MCS-TOKEN-TEST**
+
+# ANNEX A
+
+## Domain establishment, data transfer and release phases examples
+
+### A.1 MCS domain establishment phase
+
+In the domain establishment phase, the application using the MCS-CONNECT-PROVIDER asks the MCS provider to establish an MCS connection to a specific MCS provider and bind that connection to a specific domain. User applications then attach themselves to this domain using the MCS-ATTACH-USER primitive. Then, the proper channels are joined to be able to receive the appropriate data (using the MCS-CHANNEL-JOIN, MCS-CHANNEL-CONVENE, MCS-CHANNEL-ADMIT primitives).
+
+![Sequence diagram showing the establishment of MCS connections between three terminals and an MCU. The diagram illustrates three parallel connection attempts, each involving a request from a terminal, an indication to the MCU, a response from the MCU, and a confirm back to the terminal.](77959075c823bb5169480d7b8ff82a63_img.jpg)
+
+```
+
+sequenceDiagram
+    participant T1 as Terminal 1 (Control MCSAP)
+    participant T2 as Terminal 2 (Control MCSAP)
+    participant T3 as Terminal 3 (Control MCSAP)
+    participant MCU as MCU (Control MCSAP)
+
+    Note over T1, MCU: MCS provider layer
+
+    T1->>MCU: MCS-CONNECT-PROVIDER request / indication
+    MCU->>T1: MCS-CONNECT-PROVIDER response / confirm
+
+    T2->>MCU: MCS-CONNECT-PROVIDER request / indication
+    MCU->>T2: MCS-CONNECT-PROVIDER response / confirm
+
+    T3->>MCU: MCS-CONNECT-PROVIDER request / indication
+    MCU->>T3: MCS-CONNECT-PROVIDER response / confirm
+
+```
+
+T0819020-94
+
+Sequence diagram showing the establishment of MCS connections between three terminals and an MCU. The diagram illustrates three parallel connection attempts, each involving a request from a terminal, an indication to the MCU, a response from the MCU, and a confirm back to the terminal.
+
+**Figure A.1/T.122 – Establishing MCS connections**
+
+![Sequence diagram showing MCS domain establishment between Terminal 1, Terminal 2, Terminal 3, and MCU. The diagram illustrates the flow of MCS-ATTACH-USER request and MCS-ATTACH_USER confirm messages across different providers (MCS provider and Top MCS provider).](5eb69662cc4fa7d0d49b4eb22951c204_img.jpg)
+
+The diagram illustrates the MCS domain establishment process across four entities: Terminal 1, Terminal 2, Terminal 3, and MCU. Each entity has a vertical timeline with markers for 'MCSAP' (Mobile Core Service Application Provider) and 'MCS' (Mobile Core Service). The process involves sending 'MCS-ATTACH-USER request' and receiving 'MCS-ATTACH\_USER confirm' messages.
+
+- Terminal 1:** Initiates the process by sending an 'MCS-ATTACH-USER request' to the 'MCS provider' (MCSAP).
+- Terminal 2:** Initiates the process by sending an 'MCS-ATTACH-USER request' to the 'MCS provider' (MCSAP).
+- Terminal 3:** Initiates the process by sending an 'MCS-ATTACH-USER request' to the 'MCS provider' (MCSAP).
+- MCU:** Initiates the process by sending an 'MCS-ATTACH-USER request' to the 'Top MCS provider' (MCSAP).
+
+The 'MCS-ATTACH\_USER confirm' messages are received by the respective terminals from their respective providers. The diagram shows that the 'MCS-ATTACH-USER request' is sent from the terminal to the provider, and the 'MCS-ATTACH\_USER confirm' is received by the terminal from the provider.
+
+Sequence diagram showing MCS domain establishment between Terminal 1, Terminal 2, Terminal 3, and MCU. The diagram illustrates the flow of MCS-ATTACH-USER request and MCS-ATTACH\_USER confirm messages across different providers (MCS provider and Top MCS provider).
+
+T0819030-94
+
+**Figure A.2/T.122 – MCS domain establishment**
+
+![Sequence diagram showing three terminals (Terminal 1, Terminal 2, Terminal 3) sending MCS-JOIN-CHANNEL request messages to their respective MCS providers (MCS provider, MCS provider, MCS provider) and receiving MCS-JOIN_CHANNEL confirm messages. The Top MCS provider is also shown.](9a5927586a691c4908aa2cf98bd47ebb_img.jpg)
+
+The diagram illustrates the sequence of events for three terminals joining a multicast public channel. The participants are Terminal 1, Terminal 2, Terminal 3, and the MCU (Top MCS provider). Each terminal has an associated MCSAP (MCS provider) and a Top MCS provider.
+
+The sequence of events is as follows:
+
+- Terminal 1:** Sends an MCS-JOIN-CHANNEL request to its MCS provider and receives an MCS-JOIN\_CHANNEL confirm message.
+- Terminal 2:** Sends an MCS-JOIN-CHANNEL request to its MCS provider and receives an MCS-JOIN\_CHANNEL confirm message.
+- Terminal 3:** Sends an MCS-JOIN-CHANNEL request to its MCS provider and receives an MCS-JOIN\_CHANNEL confirm message.
+
+The Top MCS provider is shown as a participant in the sequence, but no messages are explicitly shown between it and the terminals in this specific sequence.
+
+T0819040-94
+
+Sequence diagram showing three terminals (Terminal 1, Terminal 2, Terminal 3) sending MCS-JOIN-CHANNEL request messages to their respective MCS providers (MCS provider, MCS provider, MCS provider) and receiving MCS-JOIN\_CHANNEL confirm messages. The Top MCS provider is also shown.
+
+**Figure A.3/T.122 – Users joining a multicast public channel:  
+All request the same channel number**
+
+![Sequence diagram showing the establishment of a private channel and subsequent user joins between Terminal 1, Terminal 2, Terminal 3, and MCU MCSAP, mediated by three MCS providers and a Top MCS provider.](0b7849dae424b0dd33e6386d2384643a_img.jpg)
+
+The diagram illustrates the sequence of events for establishing a private channel and allowing users to join it. The participants involved are Terminal 1, Terminal 2, Terminal 3, and the MCU MCSAP, all interacting through three MCS providers and a Top MCS provider.
+
+**Sequence of Events:**
+
+- Channel Establishment:**
+  - Terminal 1 sends an **MCS-CHANNEL-CONVENE request** to the first MCS provider.
+  - The first MCS provider sends an **MCS-CHANNEL-CONVENE confirm** back to Terminal 1.
+  - Terminal 1 sends an **MCS-CHANNEL-ADMIT request** to the first MCS provider.
+  - The first MCS provider sends an **MCS-CHANNEL-ADMIT indication** to Terminal 2.
+  - Terminal 2 sends an **MCS-CHANNEL-ADMIT indication** to Terminal 3.
+- User Joins:**
+  - Terminal 1 sends an **MCS-CHANNEL-JOIN request** to the first MCS provider.
+  - The first MCS provider sends an **MCS-CHANNEL-JOIN confirm** back to Terminal 1.
+  - Terminal 2 sends an **MCS-CHANNEL-JOIN request** to the second MCS provider.
+  - The second MCS provider sends an **MCS-CHANNEL-JOIN confirm** back to Terminal 2.
+  - Terminal 3 sends an **MCS-CHANNEL-JOIN request** to the third MCS provider.
+  - The third MCS provider sends an **MCS-CHANNEL-JOIN confirm** back to Terminal 3.
+
+The diagram uses vertical lines to represent the lifelines of the participants and horizontal arrows to show the direction of the messages. The first MCS provider is associated with Terminal 1, the second with Terminal 2, and the third with Terminal 3. The Top MCS provider is associated with the MCU MCSAP.
+
+T0819050-94
+
+Sequence diagram showing the establishment of a private channel and subsequent user joins between Terminal 1, Terminal 2, Terminal 3, and MCU MCSAP, mediated by three MCS providers and a Top MCS provider.
+
+**Figure A.4/T.122 – Manager establishes a private channel and then the users join it**
+
+### A.2 MCS data transfer phase
+
+The data transfer phase comprises use of the MCS-SEND-DATA and the MCS-UNIFORMLY-SEQUENCED-SEND-DATA primitives. Token operations can be performed using MCS-TOKEN-OPERATIONS primitives.
+
+![Sequence diagram showing the MCS data transfer phase between Terminal 1, Terminal 2, Terminal 3, and MCU.](834fb96b114b8fdc001625e1ae28e8b1_img.jpg)
+
+The diagram illustrates the MCS data transfer phase across four entities: Terminal 1, Terminal 2, Terminal 3, and MCU. Each entity is represented by a vertical line with a 'MCSAP' (Media Control Sublayer Access Point) at the top and an 'MCS provider' at the bottom. The sequence of events is as follows:
+
+- Terminal 1** sends an **MCS-SEND-DATA request** to **Terminal 2**.
+- Terminal 2** sends an **MCS-SEND-DATA indication** to **Terminal 1**.
+- Terminal 3** sends an **MCS-SEND-DATA indication** to **Terminal 2**.
+- MCU** sends an **MCS-SEND-DATA indication** to **Terminal 1**.
+
+The diagram uses dashed lines to represent the flow of data and solid lines for control signals. The sequence of events is indicated by arrows pointing to the corresponding lines on the vertical timelines.
+
+T0819060-94
+
+Sequence diagram showing the MCS data transfer phase between Terminal 1, Terminal 2, Terminal 3, and MCU.
+
+Figure A.5/T.122 – Sending data on a channel
+
+![Sequence diagram for Figure A.6/T.122 showing uniformly sequenced send data. The diagram involves four lifelines: Terminal 1, Terminal 2, Terminal 3, and MCU, each with an associated MCSAP layer. Below these are three MCS provider lifelines and a Top MCS provider lifeline. The sequence of events is: 1. Terminal 1 sends MCS-UNIFORM-SEND-DATA request to Terminal 2. 2. Terminal 2 sends MCS-UNIFORM-SEND-DATA indication to Terminal 1. 3. Terminal 1 sends MCS-UNIFORM-SEND-DATA indication to the first MCS provider. 4. The first MCS provider sends MCS-UNIFORM-SEND-DATA indication to Terminal 2. 5. Terminal 3 sends MCS-UNIFORM-SEND-DATA indication to the second MCS provider. 6. The second MCS provider sends MCS-UNIFORM-SEND-DATA indication to Terminal 3. 7. Terminal 3 sends MCS-UNIFORM-SEND-DATA indication to the third MCS provider. 8. The third MCS provider sends MCS-UNIFORM-SEND-DATA indication to Terminal 3. 9. Terminal 3 sends MCS-UNIFORM-SEND-DATA indication to the Top MCS provider. 10. The Top MCS provider sends MCS-UNIFORM-SEND-DATA indication to Terminal 3.](cbb2d311b20781a595488445ded48d0a_img.jpg)
+
+Terminal 1 MCSAP
+
+Terminal 2 MCSAP
+
+Terminal 3 MCSAP
+
+MCU MCSAP
+
+MCS-UNIFORM-SEND-DATA request
+
+MCS-UNIFORM-SEND-DATA indication
+
+MCS-UNIFORM-SEND-DATA indication
+
+MCS-UNIFORM-SEND-DATA indication
+
+MCS provider
+
+MCS provider
+
+MCS provider
+
+Top MCS provider
+
+T0819070-94
+
+Sequence diagram for Figure A.6/T.122 showing uniformly sequenced send data. The diagram involves four lifelines: Terminal 1, Terminal 2, Terminal 3, and MCU, each with an associated MCSAP layer. Below these are three MCS provider lifelines and a Top MCS provider lifeline. The sequence of events is: 1. Terminal 1 sends MCS-UNIFORM-SEND-DATA request to Terminal 2. 2. Terminal 2 sends MCS-UNIFORM-SEND-DATA indication to Terminal 1. 3. Terminal 1 sends MCS-UNIFORM-SEND-DATA indication to the first MCS provider. 4. The first MCS provider sends MCS-UNIFORM-SEND-DATA indication to Terminal 2. 5. Terminal 3 sends MCS-UNIFORM-SEND-DATA indication to the second MCS provider. 6. The second MCS provider sends MCS-UNIFORM-SEND-DATA indication to Terminal 3. 7. Terminal 3 sends MCS-UNIFORM-SEND-DATA indication to the third MCS provider. 8. The third MCS provider sends MCS-UNIFORM-SEND-DATA indication to Terminal 3. 9. Terminal 3 sends MCS-UNIFORM-SEND-DATA indication to the Top MCS provider. 10. The Top MCS provider sends MCS-UNIFORM-SEND-DATA indication to Terminal 3.
+
+Figure A.6/T.122 – Uniformly sequenced send data
+
+![Sequence diagram for Figure A.7/T.122 showing two users trying to grab the same token. The diagram involves four lifelines: Terminal 1, Terminal 2, Terminal 3, and MCU, each with an associated MCSAP layer. Below these are three MCS provider lifelines and a Top MCS provider lifeline. The sequence of events is: 1. Terminal 1 sends MCS-TOKEN-GRAB request to Terminal 2. 2. Terminal 2 sends MCS-TOKEN-GRAB confirm (success) to Terminal 1. 3. Terminal 3 sends MCS-TOKEN-GRAB request to Terminal 2. 4. Terminal 2 sends MCS-TOKEN-GRAB confirm (fail) to Terminal 3. 5. Terminal 3 sends MCS-TOKEN-GRAB request to the first MCS provider. 6. The first MCS provider sends MCS-TOKEN-GRAB confirm (fail) to Terminal 3. 7. Terminal 3 sends MCS-TOKEN-GRAB request to the second MCS provider. 8. The second MCS provider sends MCS-TOKEN-GRAB confirm (fail) to Terminal 3. 9. Terminal 3 sends MCS-TOKEN-GRAB request to the Top MCS provider. 10. The Top MCS provider sends MCS-TOKEN-GRAB confirm (fail) to Terminal 3.](f5a5f52bc25d95a7f616290c99e88ae6_img.jpg)
+
+Terminal 1 MCSAP
+
+Terminal 2 MCSAP
+
+Terminal 3 MCSAP
+
+MCU MCSAP
+
+MCS-TOKEN-GRAB request
+
+MCS-TOKEN-GRAB confirm (success)
+
+MCS-TOKEN-GRAB request
+
+MCS-TOKEN-GRAB confirm (fail)
+
+MCS provider
+
+MCS provider
+
+MCS provider
+
+Top MCS provider
+
+T0819080-94
+
+Sequence diagram for Figure A.7/T.122 showing two users trying to grab the same token. The diagram involves four lifelines: Terminal 1, Terminal 2, Terminal 3, and MCU, each with an associated MCSAP layer. Below these are three MCS provider lifelines and a Top MCS provider lifeline. The sequence of events is: 1. Terminal 1 sends MCS-TOKEN-GRAB request to Terminal 2. 2. Terminal 2 sends MCS-TOKEN-GRAB confirm (success) to Terminal 1. 3. Terminal 3 sends MCS-TOKEN-GRAB request to Terminal 2. 4. Terminal 2 sends MCS-TOKEN-GRAB confirm (fail) to Terminal 3. 5. Terminal 3 sends MCS-TOKEN-GRAB request to the first MCS provider. 6. The first MCS provider sends MCS-TOKEN-GRAB confirm (fail) to Terminal 3. 7. Terminal 3 sends MCS-TOKEN-GRAB request to the second MCS provider. 8. The second MCS provider sends MCS-TOKEN-GRAB confirm (fail) to Terminal 3. 9. Terminal 3 sends MCS-TOKEN-GRAB request to the Top MCS provider. 10. The Top MCS provider sends MCS-TOKEN-GRAB confirm (fail) to Terminal 3.
+
+Figure A.7/T.122 – Two users trying to grab the same token
+
+### A.3 MCS connection release phase
+
+In the connection release phase, the user leaves the channels it belongs to (MCS-CHANNEL-LEAVE, MCS-CHANNEL-DISBAND primitives), detaches (MCS-DETACH-USER primitive), and disconnect (MCS-DISCONNECT-PROVIDER primitive). If any of the above primitives are not executed, they will be automatically generated when the next in the series of connection release primitives is executed.
+
+![Sequence diagram for Figure A.8/T.122 showing the user detaching from a domain. The diagram involves four entities: Terminal 1, Terminal 2, Terminal 3, and MCU, each with an MCSAP layer and an MCS provider layer. A dashed line labeled 'MCS-DETACH-USER request' originates from Terminal 1's MCSAP and points to Terminal 2's MCSAP. Another dashed line labeled 'MCS-DETACH-USER indication' originates from Terminal 2's MCSAP and points to Terminal 3's MCSAP. A third dashed line labeled 'MCS-DETACH-USER indication' originates from Terminal 3's MCSAP and points to the MCU's MCSAP. The MCU's MCSAP is connected to the Top MCS provider. The diagram is labeled T0819090-94.](60ffbad6c0fb7371a57fe8f267d2d141_img.jpg)
+
+Terminal 1      Terminal 2      Terminal 3      MCU  
+MCSAP      MCSAP      MCSAP      MCSAP
+
+MCS-DETACH-USER request
+
+MCS-DETACH-USER indication
+
+MCS-DETACH-USER indication
+
+MCS provider      MCS provider      MCS provider      Top MCS provider
+
+T0819090-94
+
+Sequence diagram for Figure A.8/T.122 showing the user detaching from a domain. The diagram involves four entities: Terminal 1, Terminal 2, Terminal 3, and MCU, each with an MCSAP layer and an MCS provider layer. A dashed line labeled 'MCS-DETACH-USER request' originates from Terminal 1's MCSAP and points to Terminal 2's MCSAP. Another dashed line labeled 'MCS-DETACH-USER indication' originates from Terminal 2's MCSAP and points to Terminal 3's MCSAP. A third dashed line labeled 'MCS-DETACH-USER indication' originates from Terminal 3's MCSAP and points to the MCU's MCSAP. The MCU's MCSAP is connected to the Top MCS provider. The diagram is labeled T0819090-94.
+
+Figure A.8/T.122 – User detaching from a domain
+
+![Sequence diagram for Figure A.9/T.122 showing the user disconnecting after detaching. The diagram involves four entities: Terminal 1, Terminal 2, Terminal 3, and MCU, each with a Control MCSAP layer and an MCS provider layer. A dashed line labeled 'MCS-DISCONNECT-PROVIDER request' originates from Terminal 1's Control MCSAP and points to Terminal 2's Control MCSAP. Another dashed line labeled 'MCS-DISCONNECT-PROVIDER indication' originates from Terminal 2's Control MCSAP and points to the MCU's Control MCSAP. The MCU's Control MCSAP is connected to the Top MCS provider. The diagram is labeled T0819100-94.](f142b022cfc716cd967297f027efe647_img.jpg)
+
+Terminal 1      Terminal 2      Terminal 3      MCU  
+Control MCSAP      MCSAP      MCSAP      Control MCSAP
+
+MCS-DISCONNECT-PROVIDER request
+
+MCS-DISCONNECT-PROVIDER indication
+
+MCS provider      MCS provider      MCS provider      Top MCS provider
+
+T0819100-94
+
+Sequence diagram for Figure A.9/T.122 showing the user disconnecting after detaching. The diagram involves four entities: Terminal 1, Terminal 2, Terminal 3, and MCU, each with a Control MCSAP layer and an MCS provider layer. A dashed line labeled 'MCS-DISCONNECT-PROVIDER request' originates from Terminal 1's Control MCSAP and points to Terminal 2's Control MCSAP. Another dashed line labeled 'MCS-DISCONNECT-PROVIDER indication' originates from Terminal 2's Control MCSAP and points to the MCU's Control MCSAP. The MCU's Control MCSAP is connected to the Top MCS provider. The diagram is labeled T0819100-94.
+
+Figure A.9/T.122 – User disconnecting after detaching
+
+![Sequence diagram showing the process of a user disconnecting without detaching. The diagram involves four entities: Terminal 1, Terminal 2, Terminal 3, and MCU. Terminal 1 is a Control MCSAP, Terminal 2 and Terminal 3 are MCSAPs, and the MCU is a Control MCSAP. The sequence of events is: 1. MCS-DISCONNECT-PROVIDER request from Terminal 1 to MCU. 2. MCS-DISCONNECT-PROVIDER indication from MCU to Terminal 1. 3. MCS-DETACH-USER indication from Terminal 2 to Terminal 1. 4. MCS-DETACH-USER indication from Terminal 3 to Terminal 1. The diagram is labeled T0819110-94.](0a42e05c07941450f34e4f7117725834_img.jpg)
+
+```
+
+sequenceDiagram
+    participant T1 as Terminal 1  
+Control MCSAP
+    participant T2 as Terminal 2  
+MCSAP
+    participant T3 as Terminal 3  
+MCSAP
+    participant MCU as MCU  
+Control MCSAP
+
+    T1->>MCU: MCS-DISCONNECT-PROVIDER request
+    MCU-->>T1: MCS-DISCONNECT-PROVIDER indication
+    T2->>T1: MCS-DETACH-USER indication
+    T3->>T1: MCS-DETACH-USER indication
+  
+```
+
+T0819110-94
+
+Sequence diagram showing the process of a user disconnecting without detaching. The diagram involves four entities: Terminal 1, Terminal 2, Terminal 3, and MCU. Terminal 1 is a Control MCSAP, Terminal 2 and Terminal 3 are MCSAPs, and the MCU is a Control MCSAP. The sequence of events is: 1. MCS-DISCONNECT-PROVIDER request from Terminal 1 to MCU. 2. MCS-DISCONNECT-PROVIDER indication from MCU to Terminal 1. 3. MCS-DETACH-USER indication from Terminal 2 to Terminal 1. 4. MCS-DETACH-USER indication from Terminal 3 to Terminal 1. The diagram is labeled T0819110-94.
+
+**Figure A.10/T.122 – User disconnecting without detaching**
+
+# APPENDIX I
+
+## Distributed token control
+
+The definition of the token services in this Recommendation offers a centralized approach for controlling tokens. The realization of distributed control using the defined services is left for further study.
+
+## ITU-T RECOMMENDATIONS SERIES
+
+|                 |                                                                                                                                |
+|-----------------|--------------------------------------------------------------------------------------------------------------------------------|
+| Series A        | Organization of the work of the ITU-T                                                                                          |
+| Series B        | Means of expression: definitions, symbols, classification                                                                      |
+| Series C        | General telecommunication statistics                                                                                           |
+| Series D        | General tariff principles                                                                                                      |
+| Series E        | Overall network operation, telephone service, service operation and human factors                                              |
+| Series F        | Non-telephone telecommunication services                                                                                       |
+| Series G        | Transmission systems and media, digital systems and networks                                                                   |
+| Series H        | Audiovisual and multimedia systems                                                                                             |
+| Series I        | Integrated services digital network                                                                                            |
+| Series J        | Transmission of television, sound programme and other multimedia signals                                                       |
+| Series K        | Protection against interference                                                                                                |
+| Series L        | Construction, installation and protection of cables and other elements of outside plant                                        |
+| Series M        | TMN and network maintenance: international transmission systems, telephone circuits, telegraphy, facsimile and leased circuits |
+| Series N        | Maintenance: international sound programme and television transmission circuits                                                |
+| Series O        | Specifications of measuring equipment                                                                                          |
+| Series P        | Telephone transmission quality, telephone installations, local line networks                                                   |
+| Series Q        | Switching and signalling                                                                                                       |
+| Series R        | Telegraph transmission                                                                                                         |
+| Series S        | Telegraph services terminal equipment                                                                                          |
+| <b>Series T</b> | <b>Terminals for telematic services</b>                                                                                        |
+| Series U        | Telegraph switching                                                                                                            |
+| Series V        | Data communication over the telephone network                                                                                  |
+| Series X        | Data networks and open system communications                                                                                   |
+| Series Y        | Global information infrastructure                                                                                              |
+| Series Z        | Programming languages                                                                                                          |
\ No newline at end of file
diff --git a/marked/T/T-REC-T.125-199802-I_PDF-E/0adfaa8c2562a9fe3a8a96165d7d59a3_img.jpg b/marked/T/T-REC-T.125-199802-I_PDF-E/0adfaa8c2562a9fe3a8a96165d7d59a3_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..a355fd57b2755ab2a800e45cea2d8510cfa50276
--- /dev/null
+++ b/marked/T/T-REC-T.125-199802-I_PDF-E/0adfaa8c2562a9fe3a8a96165d7d59a3_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:ac38b4ca81b1cbd2f0de87e5f8d8286e7c72b6c1b198a868360a0ccb9bff5bb0
+size 53159
diff --git a/marked/T/T-REC-T.125-199802-I_PDF-E/0bbbad069459da54c1cdef84c90b316a_img.jpg b/marked/T/T-REC-T.125-199802-I_PDF-E/0bbbad069459da54c1cdef84c90b316a_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..6a2997e2f2c15c0a20d5b9428820140847997d80
--- /dev/null
+++ b/marked/T/T-REC-T.125-199802-I_PDF-E/0bbbad069459da54c1cdef84c90b316a_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:0a54a4553b2313c9a17b21b2b398bf14f0df9d66f33ac446749c24998e0cb585
+size 13466
diff --git a/marked/T/T-REC-T.125-199802-I_PDF-E/12c19090355e19922e23044633b9d1ea_img.jpg b/marked/T/T-REC-T.125-199802-I_PDF-E/12c19090355e19922e23044633b9d1ea_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..dea721bf24da3ed6bf22b50c6e1472ff0cc60e15
--- /dev/null
+++ b/marked/T/T-REC-T.125-199802-I_PDF-E/12c19090355e19922e23044633b9d1ea_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:2f7e90434eebe7a7519668d2c4b7dec8b5ae608a11b22e2868efa1b670194282
+size 62728
diff --git a/marked/T/T-REC-T.125-199802-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/T/T-REC-T.125-199802-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..1723d1ac9d7ca695483b4ee78b2146bb205bd40f
--- /dev/null
+++ b/marked/T/T-REC-T.125-199802-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:3a476b0bb69b73efd4b8fb1fd297be8f9433ccabfab6391fa767f830c8429442
+size 8239
diff --git a/marked/T/T-REC-T.125-199802-I_PDF-E/3481cde1adf61b0452dd6489dada6d6a_img.jpg b/marked/T/T-REC-T.125-199802-I_PDF-E/3481cde1adf61b0452dd6489dada6d6a_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..94677d5b56d78157f142ceedcb1799199f1d028e
--- /dev/null
+++ b/marked/T/T-REC-T.125-199802-I_PDF-E/3481cde1adf61b0452dd6489dada6d6a_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:c3ec784e63b805eb61f62c4b14fb5668296354612a7fbcd978a8c690d4e777af
+size 67949
diff --git a/marked/T/T-REC-T.125-199802-I_PDF-E/3d1817e8551f9c226a5f561108d3b3f9_img.jpg b/marked/T/T-REC-T.125-199802-I_PDF-E/3d1817e8551f9c226a5f561108d3b3f9_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..f46b5cd02ea3419196962a3c8615d6919b1658a6
--- /dev/null
+++ b/marked/T/T-REC-T.125-199802-I_PDF-E/3d1817e8551f9c226a5f561108d3b3f9_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:088d438d289277b8de9ae6ec502ad5fc766384084584ef9b0e70e365d7d4becc
+size 13687
diff --git a/marked/T/T-REC-T.125-199802-I_PDF-E/49d7bfbc65a92a7e1bd61777326a212d_img.jpg b/marked/T/T-REC-T.125-199802-I_PDF-E/49d7bfbc65a92a7e1bd61777326a212d_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..e43f7056fc3a37785fabddee85715412beafd1a3
--- /dev/null
+++ b/marked/T/T-REC-T.125-199802-I_PDF-E/49d7bfbc65a92a7e1bd61777326a212d_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:bbe9ef7b407561960db880470ee61cad2a8f9dc10054c4246f4eb08e35cc4b3c
+size 84528
diff --git a/marked/T/T-REC-T.125-199802-I_PDF-E/57134800ac3a97b6212b27b93aa196ac_img.jpg b/marked/T/T-REC-T.125-199802-I_PDF-E/57134800ac3a97b6212b27b93aa196ac_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..221606428c3fe94088496a1d7b2d209e3ea05b31
--- /dev/null
+++ b/marked/T/T-REC-T.125-199802-I_PDF-E/57134800ac3a97b6212b27b93aa196ac_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:aad83023b19bbe59e15249599e27a44d998a9ff58c57d50223c3107f65e1082d
+size 12837
diff --git a/marked/T/T-REC-T.125-199802-I_PDF-E/5e05915b2a93a3b404422e0966a7c924_img.jpg b/marked/T/T-REC-T.125-199802-I_PDF-E/5e05915b2a93a3b404422e0966a7c924_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..51b9f75bd21f38380fd4759fb18a50213ca991bb
--- /dev/null
+++ b/marked/T/T-REC-T.125-199802-I_PDF-E/5e05915b2a93a3b404422e0966a7c924_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:2abfe32e8635f30c51cfef66027f89c927c012386a40be5e50ac045baff4c0dd
+size 52349
diff --git a/marked/T/T-REC-T.125-199802-I_PDF-E/701f4311e49f346390759520fcd19af4_img.jpg b/marked/T/T-REC-T.125-199802-I_PDF-E/701f4311e49f346390759520fcd19af4_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..f5fa8517113d8018b7adb29a310347e1f9a0cc7a
--- /dev/null
+++ b/marked/T/T-REC-T.125-199802-I_PDF-E/701f4311e49f346390759520fcd19af4_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:e302447b324f3d16b63d8668cccbb2cdb2d4884b0f33fe774d67731db2e7e476
+size 67516
diff --git a/marked/T/T-REC-T.125-199802-I_PDF-E/7efae06af3af43ffe5d4b956a679cf54_img.jpg b/marked/T/T-REC-T.125-199802-I_PDF-E/7efae06af3af43ffe5d4b956a679cf54_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..dd03a629250e87a59bf67366fa872ac31c0e7011
--- /dev/null
+++ b/marked/T/T-REC-T.125-199802-I_PDF-E/7efae06af3af43ffe5d4b956a679cf54_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:f22e204ec5dc12e0ba99f09b7ac9c2ab55df7a61988f5df42610abb9c5a8922f
+size 52681
diff --git a/marked/T/T-REC-T.125-199802-I_PDF-E/8f8caebe58364416a2eda21039d8c7bf_img.jpg b/marked/T/T-REC-T.125-199802-I_PDF-E/8f8caebe58364416a2eda21039d8c7bf_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..79f9a050c64366f13552ba35634666b4319ae846
--- /dev/null
+++ b/marked/T/T-REC-T.125-199802-I_PDF-E/8f8caebe58364416a2eda21039d8c7bf_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:8fa15f1fcd7db65c5def5399bfe7b44c6f460a9749ecb308305fe42ee91f69bb
+size 48029
diff --git a/marked/T/T-REC-T.125-199802-I_PDF-E/95be50ec094942200786128aa936cfae_img.jpg b/marked/T/T-REC-T.125-199802-I_PDF-E/95be50ec094942200786128aa936cfae_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..d67b3b350351ef1147d9976373f470013d30ac3f
--- /dev/null
+++ b/marked/T/T-REC-T.125-199802-I_PDF-E/95be50ec094942200786128aa936cfae_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:2dfdcb127d91ae8b1dab7768fccba8601a94e81a53d6a7ff6f71948a01f4f3e8
+size 21325
diff --git a/marked/T/T-REC-T.125-199802-I_PDF-E/a003ffe7299e0a48bceb7f1e45a4f1a3_img.jpg b/marked/T/T-REC-T.125-199802-I_PDF-E/a003ffe7299e0a48bceb7f1e45a4f1a3_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..ed41ac3ed43faac46d9676e8234dfe043e538ba5
--- /dev/null
+++ b/marked/T/T-REC-T.125-199802-I_PDF-E/a003ffe7299e0a48bceb7f1e45a4f1a3_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:d1c4d8707c68833bf944ec611365612753bbafa62d312f86a427574d6edc234e
+size 73409
diff --git a/marked/T/T-REC-T.125-199802-I_PDF-E/a0eb8d30ac11ba97b2733c187b89ff22_img.jpg b/marked/T/T-REC-T.125-199802-I_PDF-E/a0eb8d30ac11ba97b2733c187b89ff22_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..c8b44de2ac6777b60e6169f1189c3c277c413557
--- /dev/null
+++ b/marked/T/T-REC-T.125-199802-I_PDF-E/a0eb8d30ac11ba97b2733c187b89ff22_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:92b23b867262a6ab3360d569f25feaf01d8749fbf04e30959322a75434c710ff
+size 66766
diff --git a/marked/T/T-REC-T.125-199802-I_PDF-E/b6671cfafda3820aafe9a24fa7a4d8c7_img.jpg b/marked/T/T-REC-T.125-199802-I_PDF-E/b6671cfafda3820aafe9a24fa7a4d8c7_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..51aea5cd4b315b4e7489988e7619363cb12c83a6
--- /dev/null
+++ b/marked/T/T-REC-T.125-199802-I_PDF-E/b6671cfafda3820aafe9a24fa7a4d8c7_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:a1a9ca96723760757b2657f008e078bff637b81b596341b829eb83f0ea18e4d2
+size 50574
diff --git a/marked/T/T-REC-T.125-199802-I_PDF-E/c803f6f6e2c49429d2951832bd0f208d_img.jpg b/marked/T/T-REC-T.125-199802-I_PDF-E/c803f6f6e2c49429d2951832bd0f208d_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..d6a920000b80df7d7f40c78ae7d0efd7d31a6f59
--- /dev/null
+++ b/marked/T/T-REC-T.125-199802-I_PDF-E/c803f6f6e2c49429d2951832bd0f208d_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:f273f463add340c4206a4548a4053abdc5039a16e2a6519d204962e40b4dac89
+size 11199
diff --git a/marked/T/T-REC-T.125-199802-I_PDF-E/da90447206621f137780272a2bf807a4_img.jpg b/marked/T/T-REC-T.125-199802-I_PDF-E/da90447206621f137780272a2bf807a4_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..6a7ea7a4a8a30c26f209cfa39ea5975fb39bcdf7
--- /dev/null
+++ b/marked/T/T-REC-T.125-199802-I_PDF-E/da90447206621f137780272a2bf807a4_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:8d69138e34f5ec38e75f29c88b2adb647626990faa14a972e2b29719b7280821
+size 45538
diff --git a/marked/T/T-REC-T.125-199802-I_PDF-E/dae88eec6d1005984029b794ff8b7a9e_img.jpg b/marked/T/T-REC-T.125-199802-I_PDF-E/dae88eec6d1005984029b794ff8b7a9e_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..f8a9a614d124bc0e124a22ccf84ffe9a6b89ea90
--- /dev/null
+++ b/marked/T/T-REC-T.125-199802-I_PDF-E/dae88eec6d1005984029b794ff8b7a9e_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:607da65c2ff38740a3faf667bd073945c468b421352484c55038a009497a3dd4
+size 50233
diff --git a/marked/T/T-REC-T.125-199802-I_PDF-E/ea40403ee09ad7bcb209382495f36547_img.jpg b/marked/T/T-REC-T.125-199802-I_PDF-E/ea40403ee09ad7bcb209382495f36547_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..b75f6b40f25799a03f6ae64746dd173cc1b3f1d2
--- /dev/null
+++ b/marked/T/T-REC-T.125-199802-I_PDF-E/ea40403ee09ad7bcb209382495f36547_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:e54ca433cd3f87d4efbf0059a7579f02ffe13d81ba9dc16b3ba76d044b90fcc5
+size 65818
diff --git a/marked/T/T-REC-T.125-199802-I_PDF-E/ef0faba51289e3a364ba51e5ef4d1a43_img.jpg b/marked/T/T-REC-T.125-199802-I_PDF-E/ef0faba51289e3a364ba51e5ef4d1a43_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..8699aee3a7399a35506a04b377fd77c4c6547fad
--- /dev/null
+++ b/marked/T/T-REC-T.125-199802-I_PDF-E/ef0faba51289e3a364ba51e5ef4d1a43_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:0eba899f0d8477214834ed6b4a35bf5de599814f17a0192047baef117c85074a
+size 11146
diff --git a/marked/T/T-REC-T.125-199802-I_PDF-E/f4fdce3ce1c0fd291f31813f83d0d0d3_img.jpg b/marked/T/T-REC-T.125-199802-I_PDF-E/f4fdce3ce1c0fd291f31813f83d0d0d3_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..83a356697dc92a1189085157edca464fd872fe30
--- /dev/null
+++ b/marked/T/T-REC-T.125-199802-I_PDF-E/f4fdce3ce1c0fd291f31813f83d0d0d3_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:30b0c94467fe11f1933c64a6941077c6bf89aa33acf92b69c89649a6986e8c70
+size 51343
diff --git a/marked/T/T-REC-T.125-199802-I_PDF-E/raw.md b/marked/T/T-REC-T.125-199802-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..c4d568cb8434850a0d67cf485debf2a63ac312fd
--- /dev/null
+++ b/marked/T/T-REC-T.125-199802-I_PDF-E/raw.md
@@ -0,0 +1,5716 @@
+
+
+![ITU logo: a globe with the letters ITU inside, crossed by a lightning bolt.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg)
+
+ITU logo: a globe with the letters ITU inside, crossed by a lightning bolt.
+
+INTERNATIONAL TELECOMMUNICATION UNION
+
+# ITU-T
+
+TELECOMMUNICATION  
+STANDARDIZATION SECTOR  
+OF ITU
+
+# T.125
+
+(02/98)
+
+SERIES T: TERMINALS FOR TELEMATIC SERVICES
+
+---
+
+# **Multipoint communication service protocol specification**
+
+ITU-T Recommendation T.125
+
+(Previously CCITT Recommendation)
+
+---
+
+## ITU-T T-SERIES RECOMMENDATIONS **TERMINALS FOR TELEMATIC SERVICES**
+
+![A large empty rectangular box with a double border.](c803f6f6e2c49429d2951832bd0f208d_img.jpg)
+
+A large empty rectangular box with a double border, likely intended for a diagram or additional text related to the terminal services.
+
+A large empty rectangular box with a double border.
+
+*For further details, please refer to ITU-T List of Recommendations.*
+
+## ITU-T RECOMMENDATION T.125
+
+# MULTIPOINT COMMUNICATION SERVICE PROTOCOL SPECIFICATION
+
+# Summary
+
+This Recommendation defines a protocol operating through the hierarchy of a multipoint communication domain. It specifies the format of protocol messages and procedures governing their exchange over a set of transport connections. The purpose of the protocol is to implement the Multipoint Communication Service defined by Recommendation T.122.
+
+Annex A defines a protocol allowing the use of multicast network services in a T.120 conference. It does this by performing data routing as part of T.125. Once it assumes responsibility for routing, it will use multicast whenever possible. This Annex handles sub-optimal networks by testing multicast pathways before depending on them. In the event that multicast does not work at some point within the conference, unicast is used in its place. This Annex is independent of the networks on which it is used. All issues that are specific to a given network are handled by the protocol stacks that lie beneath this protocol.
+
+The following changes have been incorporated into this version of the Recommendation:
+
+- the MAP protocol has been incorporated as Annex A;
+- MCS Protocol version 3 is specified;
+- *Extended-Parameter* MCSPDUs have been added;
+- *Capabilities-Notification* MCSPDUs have been added;
+- fields were added to the Send-Data and Uniform-Send-Data MCSPDUs to support changes to Recommendation T.122;
+- minor changes have been made to the document format.
+
+## Source
+
+ITU-T Recommendation T.125 was revised by ITU-T Study Group 16 (1997-2000) and was approved under the WTSC Resolution No. 1 procedure on the 6th of February 1998.
+
+# FOREWORD
+
+ITU (International Telecommunication Union) is the United Nations Specialized Agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the ITU. The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis.
+
+The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics.
+
+The approval of Recommendations by the Members of the ITU-T is covered by the procedure laid down in WTSC Resolution No. 1.
+
+In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC.
+
+## NOTE
+
+In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+## INTELLECTUAL PROPERTY RIGHTS
+
+The ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. The ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process.
+
+As of the date of approval of this Recommendation, the ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementors are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database.
+
+© ITU 1998
+
+All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU.
+
+# CONTENTS
+
+|                                                     | <b>Page</b> |
+|-----------------------------------------------------|-------------|
+| 1 Scope.....                                        | 1           |
+| 2 References.....                                   | 1           |
+| 3 Definitions .....                                 | 2           |
+| 4 Abbreviations.....                                | 4           |
+| 5 Overview of the MCS protocol.....                 | 4           |
+| 5.1 Model of the MCS layer .....                    | 4           |
+| 5.2 Services provided by the MCS layer.....         | 5           |
+| 5.2.1 MAP layer services.....                       | 5           |
+| 5.3 Services assumed from the transport layer ..... | 5           |
+| 5.4 Functions of the MCS layer .....                | 5           |
+| 5.4.1 Domain management.....                        | 6           |
+| 5.4.2 Channel management.....                       | 8           |
+| 5.4.3 Data transfer.....                            | 8           |
+| 5.4.4 Token management.....                         | 9           |
+| 5.4.5 Capabilities notification.....                | 9           |
+| 5.5 Hierarchical processing.....                    | 9           |
+| 5.6 Domain parameters .....                         | 11          |
+| 5.7 Extended parameters.....                        | 12          |
+| 6 Use of the transport service.....                 | 12          |
+| 6.1 Model of the transport service .....            | 12          |
+| 6.2 Use of multiple connections .....               | 13          |
+| 6.3 Transport connection release .....              | 14          |
+| 7 Structure of Version 2 MCSPDUs.....               | 14          |
+| 8 Structure of Version 3 MCSPDUs.....               | 24          |
+| 9 Encoding of MCSPDUs.....                          | 37          |
+| 10 Routing of MCSPDUs .....                         | 37          |
+| 10.1 Connect and extended parameters MCSPDUs .....  | 37          |
+| 10.2 Domain MCSPDUs.....                            | 39          |
+| 11 Meaning of MCSPDUs.....                          | 42          |
+| 11.1 Connect-Initial .....                          | 42          |
+| 11.2 Connect-Response .....                         | 43          |
+| 11.3 Connect-Additional.....                        | 44          |
+
+|                                         | <b>Page</b> |
+|-----------------------------------------|-------------|
+| 11.4 Connect-Result.....                | 44          |
+| 11.5 Extended-Parameters-Propose .....  | 45          |
+| 11.6 Extended-Parameters-Accept.....    | 45          |
+| 11.7 PlumbDomainIndication .....        | 45          |
+| 11.8 ErectDomainRequest .....           | 46          |
+| 11.9 MergeChannelsRequest .....         | 47          |
+| 11.10 MergeChannelsConfirm.....         | 48          |
+| 11.11 PurgeChannelsIndication .....     | 48          |
+| 11.12 MergeTokensRequest .....          | 49          |
+| 11.13 MergeTokensConfirm.....           | 50          |
+| 11.14 PurgeTokensIndication .....       | 51          |
+| 11.15 DisconnectProviderUltimatum ..... | 51          |
+| 11.16 RejectMCSPDUUltimatum .....       | 51          |
+| 11.17 AttachUserRequest .....           | 52          |
+| 11.18 AttachUserConfirm.....            | 52          |
+| 11.19 DetachUserRequest.....            | 52          |
+| 11.20 DetachUserIndication.....         | 53          |
+| 11.21 ChannelJoinRequest.....           | 54          |
+| 11.22 ChannelJoinConfirm.....           | 55          |
+| 11.23 ChannelLeaveRequest.....          | 55          |
+| 11.24 ChannelConveneRequest .....       | 56          |
+| 11.25 ChannelConveneConfirm .....       | 56          |
+| 11.26 ChannelDisbandRequest.....        | 56          |
+| 11.27 ChannelDisbandIndication.....     | 57          |
+| 11.28 ChannelAdmitRequest .....         | 57          |
+| 11.29 ChannelAdmitIndication.....       | 58          |
+| 11.30 ChannelExpelRequest.....          | 58          |
+| 11.31 ChannelExpelIndication.....       | 58          |
+| 11.32 SendDataRequest .....             | 59          |
+| 11.33 SendDataIndication.....           | 60          |
+| 11.34 UniformSendDataRequest .....      | 61          |
+| 11.35 UniformSendDataIndication .....   | 62          |
+| 11.36 TokenGrabRequest .....            | 62          |
+| 11.37 TokenGrabConfirm.....             | 63          |
+| 11.38 TokenInhibitRequest.....          | 63          |
+
+|                                                  | <b>Page</b> |
+|--------------------------------------------------|-------------|
+| 11.39 TokenInhibitConfirm .....                  | 64          |
+| 11.40 TokenGiveRequest.....                      | 64          |
+| 11.41 TokenGiveIndication .....                  | 64          |
+| 11.42 TokenGiveResponse .....                    | 65          |
+| 11.43 TokenGiveConfirm.....                      | 66          |
+| 11.44 TokenPleaseRequest .....                   | 66          |
+| 11.45 TokenPleaseIndication .....                | 66          |
+| 11.46 TokenReleaseRequest.....                   | 67          |
+| 11.47 TokenReleaseConfirm .....                  | 67          |
+| 11.48 TokenTestRequest .....                     | 67          |
+| 11.49 TokenTestConfirm.....                      | 68          |
+| 11.50 CapabilitiesNotificationRequest .....      | 68          |
+| 11.50.1 Request Capability.....                  | 69          |
+| 11.51 CapabilitiesNotificationIndication.....    | 69          |
+| 11.51.1 Indication Capability.....               | 69          |
+| 12 MCS provider information base .....           | 70          |
+| 12.1 Hierarchical replication.....               | 70          |
+| 12.2 Channel information .....                   | 71          |
+| 12.3 Token information .....                     | 72          |
+| 13 Elements of procedure .....                   | 74          |
+| 13.1 MCSPDU sequencing.....                      | 74          |
+| 13.2 Input flow control .....                    | 75          |
+| 13.3 Throughput enforcement.....                 | 75          |
+| 13.4 Domain configuration .....                  | 77          |
+| 13.5 Domain merger .....                         | 77          |
+| 13.6 Domain disconnection .....                  | 79          |
+| 13.7 Channel id allocation .....                 | 80          |
+| 13.8 Token status .....                          | 80          |
+| 13.9 Capabilities Notification .....             | 81          |
+| 13.9.1 Capability IDs.....                       | 81          |
+| 13.9.2 Version 3 Summits .....                   | 81          |
+| 13.9.3 Rules of capability selection.....        | 82          |
+| 13.9.4 Establishing the V3 summit provider ..... | 83          |
+| 13.9.5 Expanding the V3 summit .....             | 83          |
+| 13.9.6 Processing PDU's at a leaf node .....     | 83          |
+
+|                                                                  | <b>Page</b> |
+|------------------------------------------------------------------|-------------|
+| 13.9.7 Processing PDUs at an intermediate node .....             | 84          |
+| 13.10 Protocol version arbitration .....                         | 88          |
+| 13.11 Protocol version interoperability.....                     | 88          |
+| Annex A – Multicast adaptation protocol .....                    | 89          |
+| A.1 Scope.....                                                   | 89          |
+| A.2 Normative references .....                                   | 90          |
+| A.3 Definitions .....                                            | 91          |
+| A.4 Abbreviations.....                                           | 92          |
+| A.5 Overview.....                                                | 92          |
+| A.5.1 The use of multicast.....                                  | 93          |
+| A.5.2 Multicast islands .....                                    | 93          |
+| A.5.3 Multicast group providers.....                             | 95          |
+| A.5.4 Data ordering .....                                        | 95          |
+| A.5.5 Use of multicast and unreliable unicast.....               | 96          |
+| A.6 Use of MAP .....                                             | 96          |
+| A.6.1 Domain management.....                                     | 96          |
+| A.6.2 Channel management.....                                    | 97          |
+| A.6.3 Data transfer.....                                         | 97          |
+| A.6.4 Token management.....                                      | 99          |
+| A.7 Use of transport protocols.....                              | 99          |
+| A.7.1 Unicast transport protocols.....                           | 100         |
+| A.7.2 Multicast transport protocols .....                        | 102         |
+| A.7.3 Local information .....                                    | 103         |
+| A.8 Protocol specification .....                                 | 104         |
+| A.8.1 Establishing the initial reliable unicast connection ..... | 104         |
+| A.8.2 Arbitrating transport protocols .....                      | 105         |
+| A.8.3 Allocating and distributing multicast groups.....          | 108         |
+| A.8.4 Managing multicast data traffic (self-tuning) .....        | 109         |
+| A.8.5 Giving up on multicast .....                               | 111         |
+| A.8.6 Removing multicast groups .....                            | 111         |
+| A.9 MAP PDU descriptions .....                                   | 113         |
+| A.9.1 MAPConnectRequest .....                                    | 113         |
+| A.9.2 MAPConnectConfirm.....                                     | 114         |
+| A.9.3 MAPDisconnectRequest.....                                  | 115         |
+| A.9.4 MAPDisconnectConfirm .....                                 | 115         |
+| A.9.5 MAPArbitrateProtocolsRequest .....                         | 115         |
+
+|                                          | <b>Page</b> |
+|------------------------------------------|-------------|
+| A.9.6 MAPArbitrateProtocolsConfirm ..... | 118         |
+| A.9.7 MAPData .....                      | 120         |
+| A.9.8 MAPAddGroupRequest.....            | 122         |
+| A.9.9 MAPRemoveGroupRequest .....        | 124         |
+| A.9.10 MAPDisableUnicastRequest .....    | 124         |
+| A.9.11 MAPEnableUnicastRequest .....     | 125         |
+| A.9.12 MAPEnableUnicastConfirm.....      | 125         |
+| A.9.13 MAPDisableMulticastRequest .....  | 126         |
+| A.9.14 MAPDisableMulticastConfirm.....   | 126         |
+| A.9.15 MAPEnableMulticastRequest .....   | 126         |
+| A.9.16 MAPSequenceNumber .....           | 127         |
+| A.10 MAPPPDU ASN.1 Definition .....      | 127         |
+
+
+
+# **Recommendation T.125**
+
+# **MULTIPOINT COMMUNICATION SERVICE PROTOCOL SPECIFICATION**
+
+(revised in 1998)
+
+# **1 Scope**
+
+This Recommendation specifies:
+
+- a) procedures for a single protocol for the transfer of data and control information from one MCS provider to a peer MCS provider;
+- b) the structure and encoding of the MCS protocol data units used for the transfer of data and control information.
+
+The procedures are defined in terms of:
+
+- a) the interactions between peer MCS providers through the exchange of MCS protocol data units;
+- b) the interactions between an MCS provider and MCS users through the exchange of MCS primitives;
+- c) the interactions between an MCS provider and a transport service provider through the exchange of transport service primitives.
+
+These procedures are applicable to instances of multipeer communication among systems that support MCS and wish to interconnect in an open systems environment.
+
+# **2 References**
+
+The following Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision: all users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published.
+
+- ITU-T Recommendation T.122 (1998), *Multipoint Communication Service – Service definition*.
+- ITU-T Recommendation T.123 (1996), *Network specific data protocol stacks for multimedia conferencing*.
+- ITU-T Recommendation X.200 (1994) | ISO/IEC 7498-1:1994, *Information technology – Open Systems Interconnection – Basic reference model: The basic model*.
+- ITU-T Recommendation X.214 (1995) | ISO/IEC 8072:1996, *Information technology – Open Systems Interconnection – Transport service definition*.
+- ITU-T Recommendation X.680 (1997) | ISO/IEC 8824-1:1998, *Information technology – Abstract Syntax Notation One (ASN.1) – Specification of basic notation*.
+- ITU-T Recommendation X.690 (1997) | ISO/IEC 8825-1:1998, *Information technology – ASN.1 encoding rules: Specification of Basic Encoding Rules (BER), Canonical Encoding Rules (CER) and Distinguished Encoding Rules (DER)*.
+
+- ITU-T Recommendation X.691 (1997) | ISO/IEC 8825-2:1998, *Information technology – ASN.1 encoding rules – Specification of Packed Encoding Rules (PER)*.
+
+# 3 Definitions
+
+NOTE – These definitions make use of the abbreviations defined in clause 4.
+
+This Recommendation is based on the concepts developed in Recommendation X.200 and makes use of the following terms defined therein:
+
+- a) flow control;
+- b) reassembling;
+- c) recombining;
+- d) segmenting;
+- e) sequencing;
+- f) splitting;
+- g) transfer syntax;
+- h) transport connection;
+- i) transport connection endpoint identifier;
+- j) transport service;
+- k) transport service access point;
+- l) transport service access point address;
+- m) transport service data unit.
+
+This Recommendation is also based on the concepts developed in Recommendation T.122 and makes use of the following terms defined therein:
+
+- a) control MCSAP;
+- b) MCS attachment;
+- c) MCS channel;
+- d) MCS connection;
+- e) MCS domain;
+- f) MCS domain selector;
+- g) MCS private channel;
+- h) MCS private channel manager;
+- i) MCS provider;
+- j) MCS service access point;
+- k) MCS user;
+- l) MCS user id;
+- m) top MCS provider.
+
+For the purposes of this Recommendation, the following definitions apply.
+
+**3.1 MCS service data unit:** An amount of MCS user data whose identity is preserved during the transfer from transmitter to receivers. Specifically, the content of one MCS-SEND-DATA request or one MCS-UNIFORM-SEND-DATA request.
+
+- 3.2 MCS interface data unit:** The unit of information transferred across an MCSAP between an MCS user and an MCS provider in a single interaction. Each MCS interface data unit contains interface control information and may also contain all or part of an MCS service data unit.
+- 3.3 MCS protocol data unit:** A unit of information exchanged in the MCS protocol, consisting of control information transferred between MCS providers to coordinate their joint operation and possibly data transferred on behalf of MCS users to whom they are providing service.
+- 3.4 MCS data transfer priority:** One of four levels: top, high, medium, low. The value is communicated unchanged from transmitter to receivers. Depending on an MCS domain parameter for the number of distinct data transfer priorities implemented, two or more lowest priorities may receive the same quality of service.
+- 3.5 valid MCSPDU:** An MCSPDU whose structure and encoding complies with this Recommendation.
+- 3.6 invalid MCSPDU:** An MCSPDU that is not a valid MCSPDU.
+- 3.7 protocol error:** Use of an MCSPDU in a manner inconsistent with the procedures of this Recommendation.
+- 3.8 connect MCSPDU:** Any one of **Connect-Initial**, **Connect-Response**, **Connect-Additional**, **Connect-Result**.
+- 3.9 extended parameters MCSPDU:** Either **Extended-Parameter-Propose** or **Extended-Parameter-Accept**.
+- 3.10 domain MCSPDU:** Any MCSPDU that is not a connect MCSPDU or an extended parameter MCSPDU.
+- 3.11 data MCSPDU:** Any one of **SendDataRequest**, **SendDataIndication**, **UniformSendDataRequest**, **UniformSendDataIndication**.
+- 3.12 control MCSPDU:** Any domain MCSPDU that is not a data MCSPDU.
+- 3.13 initial TC:** The first transport connection of an MCS connection, used to exchange control MCSPDUs and data MCSPDUs of top priority.
+- 3.14 additional TC:** A subsequent transport connection belonging to an MCS connection, used to exchange data MCSPDUs of lesser priority.
+- 3.15 subtree of an MCS provider:** In the context of an MCS domain, this consists of the MCS provider itself and its MCS attachments plus all MCS providers hierarchically subordinate to it and their MCS attachments.
+- 3.16 height of an MCS provider:** In the context of an MCS domain, this is the maximum height of all hierarchically subordinate MCS providers. An MCS provider without subordinates has height zero.
+- 3.17 version 3 or V3 summit:** The MCS providers in a Domain Hierarchy which use MCS protocol version 3 or greater and are either:
+- a Top Provider; or
+  - have an upward connection path to a version 3 Top Provider that flows only through other version 3 providers.
+- 3.18 leaf node:** A node with one upward connection and no downward connections.
+- 3.19 intermediate node:** A node with one upward connection and at least one downward connection.
+
+- 3.20 superior node:** Any node with an upward connection is connected to its superior node.
+- 3.21 intervening node:** With respect to a specific node, any node in the path from the specific node to the summit provider is an intervening node.
+- 3.22 capability:** A high level behavior of the system, most likely requiring the cooperation between two or more nodes.
+- 3.23 capability ID:** An identification assigned to a capability. If standardized, this ID will be documented in T.125.
+- 3.24 participation indicator:** A characteristic of a capability which indicates the level of participation expected of V3 nodes in a V3 summit in order for the capability to be exercised. The value of a participation indicator is either partial (two or more nodes must participate) or global (all nodes must participate).
+- 3.25 partial capability:** A capability with a participation indicator of "partial".
+- 3.26 global capability:** A capability with a participation indicator of "global".
+- 3.27 summit capabilities list:** A list of capabilities available to the V3 summit.
+- 3.28 V3 summit provider:** Any top provider which is a V3 node.
+
+# 4 Abbreviations
+
+This Recommendation uses the following abbreviations.
+
+|        |                                                       |
+|--------|-------------------------------------------------------|
+| MAP    | Multicast Adaptation Protocol as described in Annex A |
+| MAPSAP | MAP Service Access Point                              |
+| MC     | MAP Connection                                        |
+| MCS    | Multipoint Communication Service                      |
+| MCSAP  | MCS Service Access Point                              |
+| MCSPDU | MCS Protocol Data Unit                                |
+| PDU    | Protocol Data Unit                                    |
+| TC     | Transport Connection                                  |
+| TS     | Transport Service                                     |
+| TSAP   | Transport Service Access Point                        |
+| TSDU   | Transport Service Data Unit                           |
+| V2     | Version 2                                             |
+| V3     | Version 3                                             |
+
+# 5 Overview of the MCS protocol
+
+## 5.1 Model of the MCS layer
+
+An MCS provider communicates with MCS users through an MCSAP by means of the MCS primitives defined in Recommendation T.122. These primitives can be the cause or result of MCSPDU exchanges between peer MCS providers using an MCS connection, or they can be the
+
+cause or result of actions taken within a single MCS provider. MCSPDU exchanges occur between MCS providers that host the same MCS domain.
+
+An MCS provider can have multiple peers, each reached directly by a different MCS connection or indirectly through a peer MCS provider. An MCS connection is composed of either one MAP connection or one or more transport connections. MAP based connections will operate as described in Annex A. For transport based connections, the number of connections will depend on the number of data transfer priorities implemented in an MCS domain. Protocol exchanges are effected using the services of the transport layer through a pair of TSAPs.
+
+This model of the MCS layer is illustrated in Figure 5-1.
+
+![Figure 5-1/T.125 – Model of the MCS layer](7efae06af3af43ffe5d4b956a679cf54_img.jpg)
+
+```
+
+graph TD
+    subgraph Top_Layer
+        MCSAP1((MCSAP))
+        MCSAP2((MCSAP))
+        MCSAP3((MCSAP))
+        MCSAP4((MCSAP))
+        MCSAP1 -.- MCSAP2 -.- MCSAP3 -.- MCSAP4
+    end
+
+    subgraph Provider_Layer
+        P1[MCS Provider]
+        P2[MCS Provider]
+        P3[MCS Provider]
+    end
+
+    subgraph Bottom_Layer
+        MAPSAP1((MAPSAP))
+        TSAP1((TSAP))
+        TSAP2((TSAP))
+        TSAP3((TSAP))
+        TSAP4((TSAP))
+        MAPSAP2((MAPSAP))
+        MAPSAP1 -.- TSAP1 -.- TSAP2 -.- TSAP3 -.- TSAP4 -.- MAPSAP2
+    end
+
+    MCSAP1 --- P1
+    MCSAP2 --- P1
+    MCSAP3 --- P2
+    MCSAP4 --- P3
+
+    P1 --- MAPSAP1
+    P1 --- TSAP1
+    P2 --- TSAP2
+    P3 --- TSAP3
+    P3 --- TSAP4
+    P3 --- MAPSAP2
+
+    TSAP1 === BUS
+    TSAP2 === BUS
+    TSAP3 === BUS
+    TSAP4 === BUS
+
+```
+
+Detailed description: The diagram shows three MCS Providers. The first provider on the left is connected to two MCSAPs above it and a MAPSAP and a TSAP below it. The middle provider is connected to one MCSAP above and one TSAP below. The third provider on the right is connected to one MCSAP above and two TSAPs and one MAPSAP below. All TSAPs are interconnected via a set of parallel lines representing transport connections at the bottom. Dashed horizontal lines connect the MCSAPs at the top and the SAPs at the bottom, indicating a logical layer boundary.
+
+Figure 5-1/T.125 – Model of the MCS layer
+
+T1602400-97
+
+**Figure 5-1/T.125 – Model of the MCS layer**
+
+## 5.2 Services provided by the MCS layer
+
+The MCS protocol supports the services defined in Recommendation T.122. Information is transferred to and from an MCS user using the MCS primitives listed in Table 5-1.
+
+### 5.2.1 MAP layer services
+
+When using MAP connections, MCS will function as described in Annex A.
+
+## 5.3 Services assumed from the transport layer
+
+For transport connections, the MCS protocol assumes the use of a subset of the connection-oriented transport service defined in Recommendation X.214. Information is transferred to and from a TS provider by the primitives listed in Table 5-2.
+
+## 5.4 Functions of the MCS layer
+
+Table 5-1 identifies the functional units of MCS and the MCSPDUs associated with each MCS primitive. MCSPDUs are defined in clause 7. The relationship between primitives and MCSPDUs can be as simple as cause and effect, in either direction. For example, MCS-ATTACH-USER request generates **AttachUserRequest**, and **AttachUserConfirm** generates MCS-ATTACH-USER confirm. Other cases may be more complicated. The completion of MCS-CONNECT-PROVIDER, for example, requires the exchange of additional MCSPDUs as side effects of the four-phase primitive.
+
+And any one of five MCSPDUs can cause an MCS-DETACH-USER indication, any of four an MCS-CHANNEL-EXPEL indication.
+
+### 5.4.1 Domain management
+
+The MCS layer maintains the integrity of the MCS connections comprising an MCS domain. An MCS connection is oriented, with one end hierarchically superior to the other. There is a single MCS provider at the top of each domain.
+
+Establishing an MCS connection merges two domains into one. The MCS layer ensures that one top provider remains. It resolves any conflicts of unique identity or exclusive ownership that may arise.
+
+Disconnecting an MCS connection splits a domain into two portions. The portion containing the top provider survives. The bottom portion eradicates itself.
+
+The MCS layer uniquely identifies users attached to a domain. Users may become aware of each other through their interactions via MCS primitives. The MCS layer notifies all users of a domain when one of them detaches. The MCS layer recovers any resources of a detached user.
+
+**Table 5-1/T.125 – MCS primitives**
+
+| <b>Functional unit</b> | <b>Primitives</b>                                                                                                                                  | <b>Associated MCSPDUs</b>                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
+|------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Domain Management      | MCS-CONNECT-PROVIDER request<br>MCS-CONNECT-PROVIDER indication<br>MCS-CONNECT-PROVIDER response<br>MCS-CONNECT-PROVIDER confirm<br>(side effects) | <b>Connect-Initial</b><br><b>Connect-Initial</b><br><b>Connect-Response</b><br><b>Connect-Response</b><br><b>Extended-Parameters-Propose</b><br><b>Extended-Parameters-Accept</b><br><b>Connect-Additional</b><br><b>Connect-Result</b><br><b>PlumbDomainIndication</b><br><b>ErectDomainRequest</b><br><b>MergeChannelsRequest</b><br><b>MergeChannelsConfirm</b><br><b>PurgeChannelsIndication</b><br><b>MergeTokensRequest</b><br><b>MergeTokensConfirm</b><br><b>PurgeTokensIndication</b> |
+|                        | MCS-DISCONNECT-PROVIDER request<br>MCS-DISCONNECT-PROVIDER indication                                                                              | <b>DisconnectProviderUltimatum</b><br><b>DisconnectProviderUltimatum</b><br><b>RejectMCSPDUUltimatum</b>                                                                                                                                                                                                                                                                                                                                                                                       |
+|                        | MCS-ATTACH-USER request<br>MCS-ATTACH-USER confirm                                                                                                 | <b>AttachUserRequest</b><br><b>AttachUserConfirm</b>                                                                                                                                                                                                                                                                                                                                                                                                                                           |
+|                        | MCS-DETACH-USER request<br>MCS-DETACH-USER indication                                                                                              | <b>DetachUserRequest</b><br><b>DetachUserIndication</b><br><b>MergeChannelsConfirm</b><br><b>PurgeChannelsIndication</b><br><b>MergeTokensConfirm</b><br><b>PurgeTokensIndication</b>                                                                                                                                                                                                                                                                                                          |
+
+**Table 5-1/T.125 – MCS primitives (concluded)**
+
+| <b>Functional unit</b>    | <b>Primitives</b>                                                                                        | <b>Associated MCSPDUs</b>                                                                                                                                       |
+|---------------------------|----------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Channel Management        | MCS-CHANNEL-JOIN request<br>MCS-CHANNEL-JOIN confirm                                                     | <b>ChannelJoinRequest</b><br><b>ChannelJoinConfirm</b>                                                                                                          |
+|                           | MCS-CHANNEL-LEAVE request<br>MCS-CHANNEL-LEAVE indication                                                | <b>ChannelLeaveRequest</b><br><b>MergeChannelsConfirm</b><br><b>PurgeChannelsIndication</b>                                                                     |
+|                           | MCS-CHANNEL-CONVENE request<br>MCS-CHANNEL-CONVENE confirm                                               | <b>ChannelConveneRequest</b><br><b>ChannelConveneConfirm</b>                                                                                                    |
+|                           | MCS-CHANNEL-DISBAND request<br>MCS-CHANNEL-DISBAND indication                                            | <b>ChannelDisbandRequest</b><br><b>MergeChannelsConfirm</b><br><b>PurgeChannelsIndication</b>                                                                   |
+|                           | MCS-CHANNEL-ADMIT request<br>MCS-CHANNEL-ADMIT indication                                                | <b>ChannelAdmitRequest</b><br><b>ChannelAdmitIndication</b>                                                                                                     |
+|                           | MCS-CHANNEL-EXPEL request<br>MCS-CHANNEL-EXPEL indication                                                | <b>ChannelExpelRequest</b><br><b>ChannelExpelIndication</b><br><b>ChannelDisbandIndication</b><br><b>MergeChannelsConfirm</b><br><b>PurgeChannelsIndication</b> |
+| Data Transfer             | MCS-SEND-DATA request<br>MCS-SEND-DATA indication                                                        | <b>SendDataRequest</b><br><b>SendDataIndication</b>                                                                                                             |
+|                           | MCS-UNIFORM-SEND-DATA request<br>MCS-UNIFORM-SEND-DATA indication                                        | <b>UniformSendDataRequest</b><br><b>UniformSendDataIndication</b>                                                                                               |
+| Token Management          | MCS-TOKEN-GRAB request<br>MCS-TOKEN-GRAB confirm                                                         | <b>TokenGrabRequest</b><br><b>TokenGrabConfirm</b>                                                                                                              |
+|                           | MCS-TOKEN-INHIBIT request<br>MCS-TOKEN-INHIBIT confirm                                                   | <b>TokenInhibitRequest</b><br><b>TokenInhibitConfirm</b>                                                                                                        |
+|                           | MCS-TOKEN-GIVE request<br>MCS-TOKEN-GIVE indication<br>MCS-TOKEN-GIVE response<br>MCS-TOKEN-GIVE confirm | <b>TokenGiveRequest</b><br><b>TokenGiveIndication</b><br><b>TokenGiveResponse</b><br><b>TokenGiveConfirm</b>                                                    |
+|                           | MCS-TOKEN-PLEASE request<br>MCS-TOKEN-PLEASE indication                                                  | <b>TokenPleaseRequest</b><br><b>TokenPleaseIndication</b>                                                                                                       |
+|                           | MCS-TOKEN-RELEASE request<br>MCS-TOKEN-RELEASE confirm                                                   | <b>TokenReleaseRequest</b><br><b>TokenReleaseConfirm</b>                                                                                                        |
+|                           | MCS-TOKEN-TEST request<br>MCS-TOKEN-TEST confirm                                                         | <b>TokenTestRequest</b><br><b>TokenTestConfirm</b>                                                                                                              |
+| Capabilities Notification |                                                                                                          | <b>CapabilitiesNotificationRequest</b><br><b>CapabilitiesNotificationIndication</b>                                                                             |
+
+**Table 5-2/T.125 – Transport service primitives**
+
+| Primitives                                                        | Use | Parameters            | Use |
+|-------------------------------------------------------------------|-----|-----------------------|-----|
+| T-CONNECT request                                                 | X   | Called address        | X   |
+| T-CONNECT indication                                              | X   | Calling address       | X   |
+|                                                                   |     | Expedited data option | –   |
+|                                                                   |     | Quality of service    | X   |
+|                                                                   |     | TS user-data          | –   |
+| T-CONNECT response                                                | X   | Responding address    | –   |
+| T-CONNECT confirm                                                 | X   | Expedited data option | –   |
+|                                                                   |     | Quality of service    | X   |
+|                                                                   |     | TS user-data          | –   |
+| T-DATA request                                                    | X   | TS user-data          | X   |
+| T-DATA indication                                                 | X   |                       |     |
+| T-EXPEDITED-DATA request                                          | –   | TS user-data          | –   |
+| T-EXPEDITED-DATA indication                                       | –   |                       |     |
+| T-DISCONNECT request                                              | X   | TS user-data          | –   |
+| T-DISCONNECT indication                                           | X   | Reason                | –   |
+|                                                                   |     | TS user-data          | –   |
+| X The MCS protocol assumes that this feature is always available. |     |                       |     |
+| – The MCS protocol does not use this feature.                     |     |                       |     |
+
+### 5.4.2 Channel management
+
+The MCS layer records which parts of an MCS domain contain one or more users joined to a given channel, so that it can optimize the transfer of data to destinations that wish to receive it.
+
+The MCS layer treats user ids as single-member channels, which only the designated user is allowed to join. On request, it can create private channels to which only admitted users are allowed access or assign public channels to which no other users are currently joined.
+
+### 5.4.3 Data transfer
+
+The MCS layer maintains a sequenced flow of data to the users who have joined a channel. A channel becomes, in effect, a multicast distribution list, with a range somewhere between zero destinations and a complete broadcast.
+
+By default, the MCS layer routes data to each receiver over the shortest path of MCS connections. Optionally, it routes specified MCS service data units through the top MCS provider, thereby guaranteeing their uniform receipt at all receivers, which may include the transmitter too.
+
+The MCS layer recognizes one or more priorities of data transfer and extends them preferential processing. For fully-reliable data, the MCS layer allows MCS service data units of unlimited size through segmentation. However, for unreliable data, the size of MCS service data units may not exceed the maximum MCSPDU size minus PDU header overhead as determined by the domain parameters.
+
+The MCS layer regulates the global flow of data within a domain. The inability of a receiver to accept data at the rate it is offered eventually creates back-pressure that causes transmitters to be blocked. A user may be detached involuntarily if it fails to maintain a minimum receiving rate.
+
+The MCS layer provides both fully-reliable (i.e. guaranteed delivery) and unreliable (i.e. non-guaranteed delivery) data transfer. For fully-reliable data transfer, the MCS layer guarantees error-free receipt of transmitted data, as long as the source and destination users remain attached and
+
+the destination user remains joined to the channel. For unreliable data transfers, MCS provides ordered receipt of transmitted data, although gaps in the data stream may occur. Also, for both fully-reliable and unreliable data transfers, higher priority data takes precedence, and a surfeit of it may indefinitely delay the delivery of lower priority data.
+
+### 5.4.4 Token management
+
+The MCS layer implements token operations at the top MCS provider, thereby ensuring consistency and exclusion.
+
+### 5.4.5 Capabilities notification
+
+The MCS layer provides a mechanism for the exchange of information regarding capabilities. Via this mechanism, nodes are able to determine the state of the domain with respect to a certain capability. This allows a node to make the decision whether to exercise that capability.
+
+## 5.5 Hierarchical processing
+
+Hierarchical processing in an MCS domain is illustrated in Figure 5-2.
+
+The nodes in the figure represent MCS providers, and the labelled arrows represent MCSPDUs. This example focuses on a period of time after the domain has been established through connections between MCS providers and the use of data transfer is beginning to expand. At step 1 provider D requests on behalf of a user to join a channel over which data will be distributed, and at step 2 the request is confirmed as successful. At step 3 a user attached to provider A sends data, and the corresponding **SendDataRequest** begins to flow upward. Assuming that only attachments at providers A, C, and D are joined to the channel over which the data is being sent, the request MCSPDU is reflected downward at steps 6 and 7 as **SendDataIndication**. Provider E, aware that no other subordinate needs to receive the data, simply forwards **SendDataRequest** upward at step 4. Provider F forwards **SendDataRequest** upward at step 5 but also reflects it downward at step 6, knowing that provider C has expressed interest in the channel.
+
+MCS providers are not especially concerned with their height in the hierarchy, except for their role in maintaining an overall limit on the height of the domain and in the broad sense that they are either the top provider or they are not. The top MCS provider has no upward connection. All others have exactly one.
+
+An MCS provider records information about channels and tokens used in its subtree of an MCS domain.
+
+![Diagram illustrating hierarchical processing in an MCS domain. The hierarchy starts with the Top MCS Provider at the top. It connects to Provider F, which in turn connects to Provider E, Provider C, and Provider D. Provider E connects to Provider A and Provider B. Arrows indicate the flow of messages: 1. ChannelJoinRequest from Provider D to Top MCS Provider; 2. ChannelJoinConfirm from Top MCS Provider to Provider D; 3. SendDataRequest from Provider A to Provider E; 4. SendDataRequest from Provider B to Provider E; 5. SendDataRequest from Provider E to Provider F; 6. SendDataIndication from Provider F to Top MCS Provider; 7. SendDataIndication from Top MCS Provider to Provider F.](b6671cfafda3820aafe9a24fa7a4d8c7_img.jpg)
+
+```
+
+graph TD
+    TopMCS[Top MCS Provider]
+    ProviderF[Provider F]
+    ProviderE[Provider E]
+    ProviderA[Provider A]
+    ProviderB[Provider B]
+    ProviderC[Provider C]
+    ProviderD[Provider D]
+
+    TopMCS --- ProviderF
+    TopMCS --- ProviderD
+    ProviderF --- ProviderE
+    ProviderF --- ProviderC
+    ProviderE --- ProviderA
+    ProviderE --- ProviderB
+
+    ProviderD -- "1 ChannelJoinRequest" --> TopMCS
+    TopMCS -- "2 ChannelJoinConfirm" --> ProviderD
+    ProviderA -- "3 SendDataRequest" --> ProviderE
+    ProviderB -- "4 SendDataRequest" --> ProviderE
+    ProviderE -- "5 SendDataRequest" --> ProviderF
+    ProviderF -- "6 SendDataIndication" --> TopMCS
+    TopMCS -- "7 SendDataIndication" --> ProviderF
+  
+```
+
+T1602410-97
+
+Diagram illustrating hierarchical processing in an MCS domain. The hierarchy starts with the Top MCS Provider at the top. It connects to Provider F, which in turn connects to Provider E, Provider C, and Provider D. Provider E connects to Provider A and Provider B. Arrows indicate the flow of messages: 1. ChannelJoinRequest from Provider D to Top MCS Provider; 2. ChannelJoinConfirm from Top MCS Provider to Provider D; 3. SendDataRequest from Provider A to Provider E; 4. SendDataRequest from Provider B to Provider E; 5. SendDataRequest from Provider E to Provider F; 6. SendDataIndication from Provider F to Top MCS Provider; 7. SendDataIndication from Top MCS Provider to Provider F.
+
+**Figure 5-2/T.125 – Hierarchical processing in an MCS domain**
+
+An MCS provider records channels that are joined by users within the subtree and, for each such channel, where the joins originate, that is, from which attachments and from which downward MCS connections. It records user ids that are assigned in the subtree and where they originate. It records private channels that have either a manager or an admitted user in the subtree, and it records the associated user ids.
+
+An MCS provider records tokens that are grabbed or inhibited by users within the subtree, and it records the associated user ids.
+
+An MCS provider inspects requests arising from its subtree to verify that the initiating user id is legitimately assigned to the originating attachment or downward MCS connection. This creates rings of protection around the top MCS provider and limits how much disruption a malicious participant can cause in an otherwise cooperative domain.
+
+In general terms, to which there are several exceptions, the operation of the MCS layer can be described as follows:
+
+- a) An MCS primitive request invoked at an MCS attachment generates an MCSPDU at the corresponding MCS provider and dispatches it upward towards the top MCS provider. There, where full information about the MCS domain is held, the MCSPDU is acted on.
+- b) A confirm MCSPDU may be generated at the top MCS provider to return results to the requesting attachment. MCS providers that pass it along update their records according to the impact of the operation on their subtree. A confirm is routed to the initiating user id by consulting local records at each successive downward hop.
+- c) An indication MCSPDU may be generated instead to inform other attachments about the action taken. Indications may be replicated and sent downward on several connections that lead to affected users. MCS providers may also update their records with the impact of an operation as part of processing an indication.
+
+The preceding description is an overview intended to create a conceptual framework. Full details are specified in later clauses concerning the information recorded in an MCS provider and how specific MCSPDUs are processed.
+
+Among exceptions are the following: Some requests, notably **ChannelJoinRequest** and **ChannelLeaveRequest**, may stop rising at a level short of the top provider, and some indications, notably **SendDataIndication**, may be generated at a level below the top provider. One MCSPDU, **TokenGiveResponse**, belongs to the response category. And some MCSPDUs may be generated by an MCS provider as a continuation of processing unlike MCSPDUs, such as **ChannelLeaveRequest** following **DetachUserIndication**.
+
+## 5.6 Domain parameters
+
+The MCS providers hosting a single MCS domain allocate resources and execute procedures according to the following parameters. The values of these parameters are identical throughout a domain with the exception of Protocol Version.
+
+- a) Maximum number of MCS channels that may be in use simultaneously. This includes channels that are joined by any user, user ids that have been assigned, and private channels that have been created.
+- b) Maximum number of user ids that may be assigned simultaneously. This is a sublimit within the constraint of the preceding parameter.
+- c) Maximum number of token ids that may be grabbed or inhibited simultaneously.
+- d) Number of data transfer priorities implemented. This equals the number of TCs in an MCS connection. An MCS user may still send and receive data with priorities outside the limit. However, such priorities may be treated the same as the lowest priority that is implemented.
+- e) Enforced throughput. Although global flow control limits data transfer within a domain to the rate of the slowest receiver, receivers must not be allowed to run arbitrarily slowly. Otherwise, one party in a conference may obstruct all others. This parameter instructs MCS providers to enforce a minimum receiving rate at each MCS attachment and over each downward MCS connection. Violators run the risk of being involuntarily detached or disconnected, respectively.
+- f) Maximum height. This constrains the height of all MCS providers, in particular the top provider.
+- g) Maximum size of domain MCSPDUs. Global flow control is based on buffering domain MCSPDUs within an MCS provider (but not connect MCSPDUs). For simplicity, fixed-size buffers are assumed. An MCS provider shall not generate larger MCSPDUs. This constrains the amount of information that can be packed into a single control MCSPDU and suggests where unlimited user data should be segmented in data MCSPDUs.
+- h) Protocol version. This takes one of three values defining different encodings for domain MCSPDUs. In version three of the MCS Protocol this value is on a per connection basis. This allows version two MCS providers to exist downstream in a version three enabled conference.
+
+NOTE – A given instance of an MCS provider may operate with local resource constraints that are also parameterized. These may include the amount of memory available for buffering MCSPDUs awaiting transport, the maximum number of MCS attachments, and the maximum number of MCS connections to other providers. Such parameters are local matters and are not communicated across an MCS domain.
+
+## 5.7 Extended parameters
+
+The MCS providers who are members of the V3 summit of a single MCS domain will allocate resources and execute procedures according to the following parameters.
+
+- a) Unreliable data is supported. If unreliable data is supported in the V3 summit, this Boolean value will be True. The value of this parameter is identical throughout the V3 summit of a domain.
+- b) Domain Reference Identifier. This is not a negotiated value, but will be generated by an MCS provider to uniquely identify a specific domain. Although the same value may be used to identify different domains for different providers, it must uniquely represent one specific domain to the provider that generated the value.
+
+# 6 Use of the transport service
+
+## 6.1 Model of the transport service
+
+This description paraphrases relevant parts of Recommendation X.214 assuming that no use is made of expedited data.
+
+The transport service offers these features to a TS user:
+
+- a) Means to establish a TC with another TS user for the purpose of exchanging TSDUs. More than one TC may exist between the same pair of TS users.
+- b) Associated with each TC at its time of establishment, the opportunity to request, negotiate, and have agreed by the TS provider a certain Quality of Service as specified by parameters representing characteristics such as throughput, transit delay, residual error rate, and priority.
+- c) Means of transferring TSDUs on a TC. The transfer of TSDUs, which consist of an integral number of octets, is transparent, in that the boundaries of TSDUs and the contents of TSDUs are preserved unchanged by the TS provider.
+- d) Means by which a receiving TS user may control the rate at which the sending TS user may send data.
+- e) The unconditional and therefore possibly destructive release of a TC.
+
+The operation of a TC is modelled in an abstract way by a pair of queues linking two TSAPs. There is one queue for each direction of information flow. Each TC is modelled by a separate pair of queues.
+
+The queue model is used to express the flow control feature. A queue has a limited capacity, but this capacity is not necessarily either fixed or determinable. Connect, TSDU, and disconnect objects are entered and removed from a queue as the result of interactions at the two TSAPs. The ability of a TS user to add objects to a queue is determined by the behavior of the TS user removing objects from that queue and the state of the queue. The only objects that can be placed in a queue by the TS provider are disconnect objects. Objects are added to a queue subject to control by the TS provider. Objects are normally removed from the queue subject to control by the receiving TS user. Objects are normally removed in the same order that they were added. The only exception to normal removal is that an object may be deleted by the TS provider if, and only if, the following one is a disconnect object.
+
+A TC endpoint identification mechanism must be provided locally if the TS user and the TS provider need to distinguish between several TCs at a TSAP. All primitives must then make use of this identification mechanism to identify the TC to which they apply. This implicit identification is not
+
+shown as a parameter of the TS primitives and must not be confused with the address parameters of T-CONNECT.
+
+## 6.2 Use of multiple connections
+
+An MCS connection consists of one or more TCs between the same pair of MCS providers. The first TC established is called the initial TC; those established subsequently are called additional TCs. All the TCs that belong to one MCS connection are established by the same MCS provider, in reaction to an MCS-CONNECT-PROVIDER request. This request contains address parameters that are the calling and called TSAP addresses. These are used unmodified in the T-CONNECT requests that result.
+
+The number of TCs per MCS connection is uniform throughout an MCS domain. This domain parameter equals the number of data transfer priority levels implemented. Separate TCs are required because each is a vehicle for flow control. Blockages in lower priority data should not result in back pressure against higher priority data. To be fully implemented, lower and higher priority data must be carried on different TCs.
+
+The quality of service requested for a TC may vary depending on the data priority for which it is established. These quality of service targets need not be uniform across an MCS domain.
+
+Aspects of quality of service that are of interest include maximum or average throughput and transit delay. High priority data may favour low transit delay for real-time response but may not require high throughput. Low priority data, on the other hand, may favour high throughput for bulk transfers but may not require low transit delay.
+
+TC priority is another aspect of quality of service, although it does not align precisely with the concept of MCS data transfer priority. It specifies the relative order in which TCs are to have their quality of service degraded, if necessary. High TC priority may be requested along with other characteristics, like low transit delay, to ensure that MCS priority data receives the preferential treatment it deserves.
+
+Connect MCSPDUs occur only as the first TSDU carried in either direction of a TC. **Connect-Initial** and **Connect-Response** traverse the initial TC of an MCS connection. **Connect-Additional** and **Connect-Result** traverse additional TCs, if any.
+
+A calling MCS provider, issuing T-CONNECT requests, controls through its own actions which TCs are part of the same MCS connection and what data transfer priorities they represent.
+
+A called MCS provider, receiving T-CONNECT indications, must in general accept a TC and read its first TSDU before learning its significance. **Connect-Initial** identifies an incoming TC as the beginning of a new MCS connection. **Connect-Additional** identifies an incoming TC as part of an MCS connection in progress.
+
+**Connect-Additional** contains a value assigned by the called MCS provider and conveyed to the calling MCS provider in a **Connect-Response** over the initial TC that designates the additional TC as belonging to the same MCS connection. **Connect-Additional** also states explicitly the data priority that the TC represents.
+
+Connect MCSPDUs are exchanged immediately following TC establishment. Once an MCS connection has been confirmed, it becomes part of a hierarchical MCS domain. Thereafter the MCS connection conveys domain MCSPDUs.
+
+With the exception of data MCSPDUs, domain MCSPDUs traverse the initial TC of an MCS connection. Data MCSPDUs traverse the TC that corresponds to their data priority. If the priority specified is beyond the number implemented in an MCS domain, a data MCSPDU traverses the TC of the lowest priority that is implemented.
+
+If only one priority is implemented in an MCS domain, its MCS connections each consist of a single TC, no use is made of **Connect-Additional** or **Connect-Result**, and all MCSPDUs travel in sequence between providers.
+
+## 6.3 Transport connection release
+
+A TS provider adds reliability to end-to-end connections by executing enough protocol to compensate for any weakness in underlying network services. An MCS provider does not duplicate this functionality. It does not attempt further automatic recovery in the event of a transport failure.
+
+Unrecoverable errors are announced through a T-DISCONNECT indication. If any of the TCs belonging to an MCS connection is disconnected, the others are immediately disconnected too. Unless this was requested by the user, an MCS-DISCONNECT-PROVIDER indication is generated, and the reason is given as provider-initiated.
+
+An MCS-DISCONNECT-PROVIDER request, on the other hand, should appear as an indication at the other side with the reason given as user-requested. Despite assurances in X.214, the simplest class of transport protocol does not allow passing user data in T-DISCONNECT. Hence, the disconnect reason code is transferred in an explicit MCSPDU. This MCSPDU compels an MCS provider, upon receipt, to disconnect the MCS connection that conveyed it.
+
+# 7 Structure of Version 2 MCSPDUs
+
+The structure of version 2 MCSPDUs is specified using the notation ASN.1 of Recommendation X.208. The use and significance of these MCSPDUs is further described in clauses 9 and 10.
+
+**MCS-PROTOCOL DEFINITIONS ::=**
+
+**BEGIN**
+
+*-- Part 1: Fundamental MCS types*
+
+**ChannelId ::= INTEGER (0..65535)** *-- range is 16 bits*
+
+**StaticChannelId ::= ChannelId (1..1000)** *-- those known permanently*
+
+**DynamicChannelId ::= ChannelId (1001..65535)** *-- those created and deleted*
+
+**UserId ::= DynamicChannelId** *-- created by Attach-User*  
+*-- deleted by Detach-User*
+
+**PrivateChannelId ::= DynamicChannelId** *-- created by Channel-Convene*  
+*-- deleted by Channel-Disband*
+
+**AssignedChannelId ::= DynamicChannelId** *-- created by Channel-Join zero*  
+*-- deleted by last Channel-Leave*
+
+**TokenId ::= INTEGER (1..65535)** *-- all are known permanently*
+
+**TokenStatus ::= ENUMERATED**
+
+{
+
+|                       |             |
+|-----------------------|-------------|
+| <b>notInUse</b>       | <b>(0),</b> |
+| <b>selfGrabbed</b>    | <b>(1),</b> |
+| <b>otherGrabbed</b>   | <b>(2),</b> |
+| <b>selfInhibited</b>  | <b>(3),</b> |
+| <b>otherInhibited</b> | <b>(4),</b> |
+| <b>selfRecipient</b>  | <b>(5),</b> |
+
+}
+
+```
+
+        selfGiving                (6),
+        otherGiving                (7)
+    }
+
+DataPriority ::= ENUMERATED
+{
+    top                (0),
+    high               (1),
+    medium             (2),
+    low                (3)
+}
+
+Segmentation ::= BIT STRING
+{
+    begin                (0),
+    end                  (1)
+} (SIZE (2))
+
+DomainParameters ::= SEQUENCE
+{
+    maxChannelIds        INTEGER (0..MAX),
+                        -- a limit on channel ids in use,
+                        -- static + user id + private + assigned
+    maxUserIds           INTEGER (0..MAX),
+                        -- a sublimit on user id channels alone
+    maxTokenIds          INTEGER (0..MAX),
+                        -- a limit on token ids in use
+                        -- grabbed + inhibited + giving + ungivable + given
+    numPriorities        INTEGER (0..MAX),
+                        -- the number of TCs in an MCS connection
+    minThroughput        INTEGER (0..MAX),
+                        -- the enforced number of octets per second
+    maxHeight            INTEGER (0..MAX),
+                        -- a limit on the height of a provider
+    maxMCSPDUsize        INTEGER (0..MAX),
+                        -- an octet limit on domain MCSPDUs
+    protocolVersion      INTEGER (0..MAX)
+}
+
+```
+
+-- Part 2: Connect provider
+
+```
+
+Connect-Initial ::= [APPLICATION 101] IMPLICIT SEQUENCE
+{
+    callingDomainSelector    OCTET STRING,
+    calledDomainSelector     OCTET STRING,
+    upwardFlag               BOOLEAN,
+                        -- TRUE if called provider is higher
+    targetParameters         DomainParameters,
+    minimumParameters        DomainParameters,
+    maximumParameters        DomainParameters,
+    userData                 OCTET STRING
+}
+
+```
+
+```
+
+Connect-Response ::= [APPLICATION 102] IMPLICIT SEQUENCE
+{
+    result                  Result,
+    calledConnectId         INTEGER (0..MAX),
+                        -- assigned by the called provider
+                        -- to identify additional TCs of
+                        -- the same MCS connection
+    domainParameters        DomainParameters,
+}
+
+```
+
+```
+
+    userData                                OCTET STRING
+}
+
+Connect-Additional ::= [APPLICATION 103] IMPLICIT SEQUENCE
+{
+    calledConnectId                         INTEGER (0..MAX),
+    dataPriority                            DataPriority
+}
+
+Connect-Result ::= [APPLICATION 104] IMPLICIT SEQUENCE
+{
+    result                                  Result
+}
+
+-- Part 3: Merge domain
+
+PlumbDomainIndication ::= [APPLICATION 0] IMPLICIT SEQUENCE
+{
+    heightLimit                             INTEGER (0..MAX)
+                                            -- a restriction on the MCSPDU receiver
+}
+
+ErectDomainRequest ::= [APPLICATION 1] IMPLICIT SEQUENCE
+{
+    subHeight                               INTEGER (0..MAX),
+                                            -- height in domain of the MCSPDU transmitter
+    subInterval                             INTEGER (0..MAX)
+                                            -- its throughput enforcement interval in milliseconds
+}
+
+ChannelAttributes ::= CHOICE
+{
+    static                                  [0] IMPLICIT SEQUENCE
+    {
+        channelId                           StaticChannelId
+                                            -- joined is implicitly TRUE
+    },
+
+    userId                                  [1] IMPLICIT SEQUENCE
+    {
+        joined                              BOOLEAN,
+                                            -- TRUE if user is joined to its user id
+        userId                              UserId
+    },
+
+    private                                 [2] IMPLICIT SEQUENCE
+    {
+        joined                              BOOLEAN,
+                                            -- TRUE if channel id is joined below
+        channelId                           PrivateChannelId,
+        manager                             UserId,
+        admitted                            SET OF UserId
+                                            -- may span multiple MergeChannelsRequest
+    },
+
+    assigned                                [3] IMPLICIT SEQUENCE
+    {
+        channelId                           AssignedChannelId
+                                            -- joined is implicitly TRUE
+    }
+}
+
+```
+
+**MergeChannelsRequest ::= [APPLICATION 2] IMPLICIT SEQUENCE**
+
+```
+{
+    mergeChannels          SET OF ChannelAttributes,
+    purgeChannelIds        SET OF ChannelId
+}
+```
+
+**MergeChannelsConfirm ::= [APPLICATION 3] IMPLICIT SEQUENCE**
+
+```
+{
+    mergeChannels          SET OF ChannelAttributes,
+    purgeChannelIds        SET OF ChannelId
+}
+```
+
+**PurgeChannelsIndication ::= [APPLICATION 4] IMPLICIT SEQUENCE**
+
+```
+{
+    detachUserIds          SET OF UserId,
+                           -- purge user id channels
+    purgeChannelIds        SET OF ChannelId
+                           -- purge other channels
+}
+```
+
+**TokenAttributes ::= CHOICE**
+
+```
+{
+    grabbed                [0] IMPLICIT SEQUENCE
+    {
+        tokenId            TokenId,
+        grabber             UserId
+    },
+    inhibited               [1] IMPLICIT SEQUENCE
+    {
+        tokenId            TokenId,
+        inhibitors          SET OF UserId
+                           -- may span multiple MergeTokensRequest
+    },
+    giving                  [2] IMPLICIT SEQUENCE
+    {
+        tokenId            TokenId,
+        grabber            UserId,
+        recipient           UserId
+    },
+    ungivable               [3] IMPLICIT SEQUENCE
+    {
+        tokenId            TokenId,
+        grabber            UserId
+                           -- recipient has since detached
+    },
+    given                   [4] IMPLICIT SEQUENCE
+    {
+        tokenId            TokenId,
+        recipient           UserId
+                           -- grabber released or detached
+    }
+}
+```
+
+**MergeTokensRequest ::= [APPLICATION 5] IMPLICIT SEQUENCE**
+
+```
+{
+    mergeTokens            SET OF TokenAttributes,
+    purgeTokenIds          SET OF TokenId
+}
+```
+
+```
+
+}
+
+MergeTokensConfirm ::= [APPLICATION 6] IMPLICIT SEQUENCE
+{
+    mergeTokens          SET OF TokenAttributes,
+    purgeTokenIds        SET OF TokenId
+}
+
+PurgeTokensIndication ::= [APPLICATION 7] IMPLICIT SEQUENCE
+{
+    purgeTokenIds        SET OF TokenId
+}
+-- Part 4: Disconnect provider
+
+DisconnectProviderUltimatum ::= [APPLICATION 8] IMPLICIT SEQUENCE
+{
+    reason                Reason
+}
+
+RejectMCSPDUUltimatum ::= [APPLICATION 9] IMPLICIT SEQUENCE
+{
+    diagnostic            Diagnostic,
+    initialOctets         OCTET STRING
+}
+-- Part 5: Attach/Detach user
+
+AttachUserRequest ::= [APPLICATION 10] IMPLICIT SEQUENCE
+{
+}
+
+AttachUserConfirm ::= [APPLICATION 11] IMPLICIT SEQUENCE
+{
+    result                Result,
+    initiator             UserId OPTIONAL
+}
+
+DetachUserRequest ::= [APPLICATION 12] IMPLICIT SEQUENCE
+{
+    reason                Reason,
+    userIds               SET OF UserId
+}
+
+DetachUserIndication ::= [APPLICATION 13] IMPLICIT SEQUENCE
+{
+    reason                Reason,
+    userIds               SET OF UserId
+}
+-- Part 6: Channel management
+
+ChannelJoinRequest ::= [APPLICATION 14] IMPLICIT SEQUENCE
+{
+    initiator             UserId,
+    channelId             ChannelId
+    -- may be zero
+}
+
+```
+
+**ChannelJoinConfirm ::= [APPLICATION 15] IMPLICIT SEQUENCE**
+
+```
+{
+    result                Result,
+    initiator              UserId,
+    requested              ChannelId,
+                           -- may be zero
+    channelId              ChannelId OPTIONAL
+}
+```
+
+**ChannelLeaveRequest ::= [APPLICATION 16] IMPLICIT SEQUENCE**
+
+```
+{
+    channelIds             SET OF ChannelId
+}
+```
+
+**ChannelConveneRequest ::= [APPLICATION 17] IMPLICIT SEQUENCE**
+
+```
+{
+    initiator              UserId
+}
+```
+
+**ChannelConveneConfirm ::= [APPLICATION 18] IMPLICIT SEQUENCE**
+
+```
+{
+    result                Result,
+    initiator              UserId,
+    channelId              PrivateChannelId OPTIONAL
+}
+```
+
+**ChannelDisbandRequest ::= [APPLICATION 19] IMPLICIT SEQUENCE**
+
+```
+{
+    initiator              UserId,
+    channelId              PrivateChannelId
+}
+```
+
+**ChannelDisbandIndication ::= [APPLICATION 20] IMPLICIT SEQUENCE**
+
+```
+{
+    channelId              PrivateChannelId
+}
+```
+
+**ChannelAdmitRequest ::= [APPLICATION 21] IMPLICIT SEQUENCE**
+
+```
+{
+    initiator              UserId,
+    channelId              PrivateChannelId,
+    userIds                SET OF UserId
+}
+```
+
+**ChannelAdmitIndication ::= [APPLICATION 22] IMPLICIT SEQUENCE**
+
+```
+{
+    initiator              UserId,
+    channelId              PrivateChannelId,
+    userIds                SET OF UserId
+}
+```
+
+**ChannelExpelRequest ::= [APPLICATION 23] IMPLICIT SEQUENCE**
+
+```
+{
+    initiator              UserId,
+    channelId              PrivateChannelId,
+    userIds                SET OF UserId
+}
+```
+
+```
+
+ChannelExpelIndication ::= [APPLICATION 24] IMPLICIT SEQUENCE
+{
+    channelId                PrivateChannelId,
+    userIds                   SET OF UserId
+}
+
+```
+
+-- Part 7: Data transfer
+
+```
+
+SendDataRequest ::= [APPLICATION 25] IMPLICIT SEQUENCE
+{
+    initiator                 UserId,
+    channelId                 ChannelId,
+    dataPriority               DataPriority,
+    segmentation              Segmentation,
+    userData                  OCTET STRING
+}
+
+```
+
+```
+
+SendDataIndication ::= [APPLICATION 26] IMPLICIT SEQUENCE
+{
+    initiator                 UserId,
+    channelId                 ChannelId,
+    dataPriority               DataPriority,
+    segmentation              Segmentation,
+    userData                  OCTET STRING
+}
+
+```
+
+```
+
+UniformSendDataRequest ::= [APPLICATION 27] IMPLICIT SEQUENCE
+{
+    initiator                 UserId,
+    channelId                 ChannelId,
+    dataPriority               DataPriority,
+    segmentation              Segmentation,
+    userData                  OCTET STRING
+}
+
+```
+
+```
+
+UniformSendDataIndication ::= [APPLICATION 28] IMPLICIT SEQUENCE
+{
+    initiator                 UserId,
+    channelId                 ChannelId,
+    dataPriority               DataPriority,
+    segmentation              Segmentation,
+    userData                  OCTET STRING
+}
+
+```
+
+-- Part 8: Token management
+
+```
+
+TokenGrabRequest ::= [APPLICATION 29] IMPLICIT SEQUENCE
+{
+    initiator                 UserId,
+    tokenId                  TokenId
+}
+
+```
+
+```
+
+TokenGrabConfirm ::= [APPLICATION 30] IMPLICIT SEQUENCE
+{
+    result Result,
+    initiator                 UserId,
+    tokenId                  TokenId,
+    tokenStatus              TokenStatus
+}
+
+```
+
+```
+
+TokenInhibitRequest ::= [APPLICATION 31] IMPLICIT SEQUENCE
+{
+    initiator                UserId,
+    tokenId                  TokenId
+}
+
+TokenInhibitConfirm ::= [APPLICATION 32] IMPLICIT SEQUENCE
+{
+    result                   Result,
+    initiator                UserId,
+    tokenId                  TokenId,
+    tokenStatus              TokenStatus
+}
+
+TokenGiveRequest ::= [APPLICATION 33] IMPLICIT SEQUENCE
+{
+    initiator                UserId,
+    tokenId                  TokenId,
+    recipient                UserId
+}
+
+TokenGiveIndication ::= [APPLICATION 34] IMPLICIT SEQUENCE
+{
+    initiator                UserId,
+    tokenId                  TokenId,
+    recipient                UserId
+}
+
+TokenGiveResponse ::= [APPLICATION 35] IMPLICIT SEQUENCE
+{
+    result                   Result,
+    recipient                UserId,
+    tokenId                  TokenId
+}
+
+TokenGiveConfirm ::= [APPLICATION 36] IMPLICIT SEQUENCE
+{
+    result                   Result,
+    initiator                UserId,
+    tokenId                  TokenId,
+    tokenStatus              TokenStatus
+}
+
+TokenPleaseRequest ::= [APPLICATION 37] IMPLICIT SEQUENCE
+{
+    initiator                UserId,
+    tokenId                  TokenId
+}
+
+TokenPleaseIndication ::= [APPLICATION 38] IMPLICIT SEQUENCE
+{
+    initiator                UserId,
+    tokenId                  TokenId
+}
+
+TokenReleaseRequest ::= [APPLICATION 39] IMPLICIT SEQUENCE
+{
+    initiator                UserId,
+    tokenId                  TokenId
+}
+
+```
+
+**TokenReleaseConfirm ::= [APPLICATION 40] IMPLICIT SEQUENCE**
+
+```
+{
+    result Result,
+    initiator      UserId,
+    tokenId        TokenId,
+    tokenStatus    TokenStatus
+}
+```
+
+**TokenTestRequest ::= [APPLICATION 41] IMPLICIT SEQUENCE**
+
+```
+{
+    initiator      UserId,
+    tokenId        TokenId
+}
+```
+
+**TokenTestConfirm ::= [APPLICATION 42] IMPLICIT SEQUENCE**
+
+```
+{
+    initiator      UserId,
+    tokenId        TokenId,
+    tokenStatus    TokenStatus
+}
+```
+
+*-- Part 9: Status codes*
+
+**Reason ::= ENUMERATED** *-- in DisconnectProviderUltimatum, DetachUserRequest, DetachUserIndication*
+
+```
+{
+    rn-domain-disconnected    (0),
+    rn-provider-initiated     (1),
+    rn-token-purged           (2),
+    rn-user-requested         (3),
+    rn-channel-purged         (4)
+}
+```
+
+**Result ::= ENUMERATED** *-- in Connect, response, confirm*
+
+```
+{
+    rt-successful              (0),
+    rt-domain-merging          (1),
+    rt-domain-not-hierarchical (2),
+    rt-no-such-channel         (3),
+    rt-no-such-domain          (4),
+    rt-no-such-user            (5),
+    rt-not-admitted            (6),
+    rt-other-user-id           (7),
+    rt-parameters-unacceptable (8),
+    rt-token-not-available     (9),
+    rt-token-not-possessioned  (10),
+    rt-too-many-channels       (11),
+    rt-too-many-tokens         (12),
+    rt-too-many-users          (13),
+    rt-unspecified-failure     (14),
+    rt-user-rejected           (15)
+}
+```
+
+**Diagnostic ::= ENUMERATED** *-- in RejectMCSPDUUltimatum*
+
+```
+{
+    dc-inconsistent-merge      (0),
+    dc-forbidden-PDU-downward  (1),
+    dc-forbidden-PDU-upward    (2),
+    dc-invalid-BER-encoding     (3),
+    dc-invalid-PER-encoding     (4),
+    dc-misrouted-user          (5),
+    dc-unrequested-confirm      (6),
+}
+```
+
+|                             |       |
+|-----------------------------|-------|
+| dc-wrong-transport-priority | (7),  |
+| dc-channel-id-conflict      | (8),  |
+| dc-token-id-conflict        | (9),  |
+| dc-not-user-id-channel      | (10), |
+| dc-too-many-channels        | (11), |
+| dc-too-many-tokens          | (12), |
+| dc-too-many-users           | (13)  |
+
+}
+
+-- Part 10: MCSPDU repertoire
+
+**ConnectMCSPDU ::= CHOICE**
+
+|                           |                            |
+|---------------------------|----------------------------|
+| <b>connect-initial</b>    | <b>Connect-Initial,</b>    |
+| <b>connect-response</b>   | <b>Connect-Response,</b>   |
+| <b>connect-additional</b> | <b>Connect-Additional,</b> |
+| <b>connect-result</b>     | <b>Connect-Result</b>      |
+
+}
+
+**DomainMCSPDU ::= CHOICE**
+
+|                                    |                                     |
+|------------------------------------|-------------------------------------|
+| <b>plumbDomainIndication</b>       | <b>PlumbDomainIndication,</b>       |
+| <b>erectDomainRequest</b>          | <b>ErectDomainRequest,</b>          |
+| <b>mergeChannelsRequest</b>        | <b>MergeChannelsRequest,</b>        |
+| <b>mergeChannelsConfirm</b>        | <b>MergeChannelsConfirm,</b>        |
+| <b>purgeChannelsIndication</b>     | <b>PurgeChannelsIndication,</b>     |
+| <b>mergeTokensRequest</b>          | <b>MergeTokensRequest,</b>          |
+| <b>mergeTokensConfirm</b>          | <b>MergeTokensConfirm,</b>          |
+| <b>purgeTokensIndication</b>       | <b>PurgeTokensIndication,</b>       |
+| <b>disconnectProviderUltimatum</b> | <b>DisconnectProviderUltimatum,</b> |
+| <b>rejectMCSPDUUltimatum</b>       | <b>RejectMCSPDUUltimatum,</b>       |
+| <b>attachUserRequest</b>           | <b>AttachUserRequest,</b>           |
+| <b>attachUserConfirm</b>           | <b>AttachUserConfirm,</b>           |
+| <b>detachUserRequest</b>           | <b>DetachUserRequest,</b>           |
+| <b>detachUserIndication</b>        | <b>DetachUserIndication,</b>        |
+| <b>channelJoinRequest</b>          | <b>ChannelJoinRequest,</b>          |
+| <b>channelJoinConfirm</b>          | <b>ChannelJoinConfirm,</b>          |
+| <b>channelLeaveRequest</b>         | <b>ChannelLeaveRequest,</b>         |
+| <b>channelConveneRequest</b>       | <b>ChannelConveneRequest,</b>       |
+| <b>channelConveneConfirm</b>       | <b>ChannelConveneConfirm,</b>       |
+| <b>channelDisbandRequest</b>       | <b>ChannelDisbandRequest,</b>       |
+| <b>channelDisbandIndication</b>    | <b>ChannelDisbandIndication,</b>    |
+| <b>channelAdmitRequest</b>         | <b>ChannelAdmitRequest,</b>         |
+| <b>channelAdmitIndication</b>      | <b>ChannelAdmitIndication,</b>      |
+| <b>channelExpelRequest</b>         | <b>ChannelExpelRequest,</b>         |
+| <b>channelExpelIndication</b>      | <b>ChannelExpelIndication,</b>      |
+| <b>sendDataRequest</b>             | <b>SendDataRequest,</b>             |
+| <b>sendDataIndication</b>          | <b>SendDataIndication,</b>          |
+| <b>uniformSendDataRequest</b>      | <b>UniformSendDataRequest,</b>      |
+| <b>uniformSendDataIndication</b>   | <b>UniformSendDataIndication,</b>   |
+| <b>tokenGrabRequest</b>            | <b>TokenGrabRequest,</b>            |
+| <b>tokenGrabConfirm</b>            | <b>TokenGrabConfirm,</b>            |
+| <b>tokenInhibitRequest</b>         | <b>TokenInhibitRequest,</b>         |
+| <b>tokenInhibitConfirm</b>         | <b>TokenInhibitConfirm,</b>         |
+| <b>tokenGiveRequest</b>            | <b>TokenGiveRequest,</b>            |
+| <b>tokenGiveIndication</b>         | <b>TokenGiveIndication,</b>         |
+| <b>tokenGiveResponse</b>           | <b>TokenGiveResponse,</b>           |
+| <b>tokenGiveConfirm</b>            | <b>TokenGiveConfirm,</b>            |
+| <b>tokenPleaseRequest</b>          | <b>TokenPleaseRequest,</b>          |
+| <b>tokenPleaseIndication</b>       | <b>TokenPleaseIndication,</b>       |
+| <b>tokenReleaseRequest</b>         | <b>TokenReleaseRequest,</b>         |
+
+|                     |                      |
+|---------------------|----------------------|
+| tokenReleaseConfirm | TokenReleaseConfirm, |
+| tokenTestRequest    | TokenTestRequest,    |
+| tokenTestConfirm    | TokenTestConfirm     |
+
+}
+
+END
+
+# 8 Structure of Version 3 MCSPDUs
+
+The structure of version 3 MCSPDUs is specified using the notation ASN.1 of Recommendation X.208. The use and significance of these MCSPDUs is further described in clauses 9 and 10.
+
+**MCS-PROTOCOL-3 DEFINITIONS AUTOMATIC TAGS::=**
+
+**BEGIN**
+
+*-- Part 1: Fundamental MCS types*
+
+**H221NonStandardIdentifier ::= OCTET STRING (SIZE (4..255))**
+
+*-- First four octets shall be country  
+-- code and Manufacturer code, assigned  
+-- as specified in Annex A/H.221 for  
+-- NS-cap and NS-comm*
+
+**Key ::= CHOICE**
+
+*-- Identifier of a standard or non-standard object*
+
+|   |                        |                                  |
+|---|------------------------|----------------------------------|
+| { | <b>object</b>          | <b>OBJECT IDENTIFIER,</b>        |
+|   | <b>h221NonStandard</b> | <b>H221NonStandardIdentifier</b> |
+| } |                        |                                  |
+
+**NonStandardParameter ::= SEQUENCE**
+
+|   |             |                     |
+|---|-------------|---------------------|
+| { | <b>key</b>  | <b>Key,</b>         |
+|   | <b>data</b> | <b>OCTET STRING</b> |
+| } |             |                     |
+
+**ChannelId ::= INTEGER (0..65535)** *-- range is 16 bits*
+
+**StaticChannelId ::= ChannelId (1..1000)** *-- those known permanently*
+
+**DynamicChannelId ::= ChannelId (1001..65535)** *-- those created and deleted*
+
+**UserId ::= DynamicChannelId** *-- created by Attach-User*
+
+*-- deleted by Detach-User*
+
+**PrivateChannelId ::= DynamicChannelId**
+
+*-- created by Channel-Convene*
+
+*-- deleted by Channel-Disband*
+
+**AssignedChannelId ::= DynamicChannelId**
+
+*-- created by Channel-Join zero*
+
+*-- deleted by last Channel-Leave*
+
+**TokenId ::= INTEGER (1..65535)**
+
+*-- all are known permanently*
+
+**TokenStatus ::= CHOICE**
+
+|   |                       |              |
+|---|-----------------------|--------------|
+| { | <b>notInUse</b>       | <b>NULL,</b> |
+|   | <b>selfGrabbed</b>    | <b>NULL,</b> |
+|   | <b>otherGrabbed</b>   | <b>NULL,</b> |
+|   | <b>selfInhibited</b>  | <b>NULL,</b> |
+|   | <b>otherInhibited</b> | <b>NULL,</b> |
+
+```
+
+        selfRecipient          NULL,
+        selfGiving             NULL,
+        otherGiving             NULL,
+        ...
+    }
+
+DataPriority ::= CHOICE
+{
+    top          NULL,
+    high         NULL,
+    medium       NULL,
+    low          NULL,
+    ...
+}
+
+Segmentation ::= BIT STRING
+{
+    begin        (0),
+    end          (1)
+} (SIZE (2))
+
+-- Part 2: Extended parameter
+
+ExtendedParameters ::= SEQUENCE
+{
+    unreliableDataSupported    BOOLEAN,
+    domainReferenceID          INTEGER (0 .. 65535),
+    nonStandard                 SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+ExtendedParameterPropose ::= SEQUENCE
+{
+    targetExtendedParameters    ExtendedParameters,
+    minimumExtendedParameters   ExtendedParameters,
+    maximumExtendedParameters   ExtendedParameters,
+    nonStandard                 SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+ExtendedParameterAccept ::= SEQUENCE
+{
+    extendedParameters          ExtendedParameters,
+    nonStandard                 SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+-- Part 3: Merge domain
+
+PlumbDomainIndication ::= SEQUENCE
+{
+    heightLimit                 INTEGER (0..MAX),
+                                -- a restriction on the MCSPDU receiver
+    nonStandard                 SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+```
+
+**ErectDomainRequest ::= SEQUENCE**
+
+```
+{
+    subHeight           INTEGER (0..MAX),
+                        -- height in domain of the MCSPDU transmitter
+    subInterval          INTEGER (0..MAX),
+                        -- its throughput enforcement interval in milliseconds
+    nonStandard          SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+```
+
+**ChannelAttributes ::= CHOICE**
+
+```
+{
+    static              SEQUENCE
+    {
+        channelId       StaticChannelId,
+                        -- joined is implicitly TRUE
+        nonStandard     SEQUENCE OF NonStandardParameter OPTIONAL,
+        ...
+    },
+
+    userId              SEQUENCE
+    {
+        joined          BOOLEAN,
+                        -- TRUE if user is joined to its user id
+        userId          UserId,
+        nonStandard     SEQUENCE OF NonStandardParameter OPTIONAL,
+        ...
+    },
+
+    private             SEQUENCE
+    {
+        joined          BOOLEAN,
+                        -- TRUE if channel id is joined below
+        channelId       PrivateChannelId,
+        manager         UserId,
+        admitted        SET OF UserId,
+                        -- may span multiple MergeChannelsRequest
+        nonStandard     SEQUENCE OF NonStandardParameter OPTIONAL,
+        ...
+    },
+
+    assigned            SEQUENCE
+    {
+        channelId       AssignedChannelId,
+                        -- joined is implicitly TRUE
+        nonStandard     SEQUENCE OF NonStandardParameter OPTIONAL,
+        ...
+    },
+    ...
+}
+```
+
+**MergeChannelsRequest ::= SEQUENCE**
+
+```
+{
+    mergeChannels       SET OF ChannelAttributes,
+    purgeChannelIds     SET OF ChannelId,
+    nonStandard         SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+```
+
+```
+
+MergeChannelsConfirm ::= SEQUENCE
+{
+    mergeChannels          SET OF ChannelAttributes,
+    purgeChannelIds        SET OF ChannelId,
+    nonStandard            SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+PurgeChannelsIndication ::= SEQUENCE
+{
+    detachChannelIds       SET OF ChannelId,
+                           -- purge user id channels
+    purgeChannelIds        SET OF ChannelId,
+                           -- purge other channels
+    nonStandard            SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+TokenAttributes ::= CHOICE
+{
+    grabbed                SEQUENCE
+    {
+        tokenId            TokenId,
+        grabber            UserId,
+        nonStandard        SEQUENCE OF NonStandardParameter OPTIONAL,
+        ...
+    },
+
+    inhibited              SEQUENCE
+    {
+        tokenId            TokenId,
+        inhibitors         SET OF UserId,
+                           -- may span multiple MergeTokensRequest
+        nonStandard        SEQUENCE OF NonStandardParameter OPTIONAL,
+        ...
+    },
+
+    giving                SEQUENCE
+    {
+        tokenId            TokenId,
+        grabber            UserId,
+        recipient          UserId,
+        nonStandard        SEQUENCE OF NonStandardParameter OPTIONAL,
+        ...
+    },
+
+    ungivable             SEQUENCE
+    {
+        tokenId            TokenId,
+        grabber            UserId,
+                           -- recipient has since detached
+        nonStandard        SEQUENCE OF NonStandardParameter OPTIONAL,
+        ...
+    },
+
+    given                 SEQUENCE
+    {
+        tokenId            TokenId,
+        recipient          UserId,
+                           -- grabber released or detached
+        nonStandard        SEQUENCE OF NonStandardParameter OPTIONAL,
+        ...
+    }
+}
+
+```
+
+```
+
+    },
+    ...
+}
+
+MergeTokensRequest ::= SEQUENCE
+{
+    mergeTokens          SET OF TokenAttributes,
+    purgeTokenIds        SET OF TokenId,
+    nonStandard          SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+MergeTokensConfirm ::= SEQUENCE
+{
+    mergeTokens          SET OF TokenAttributes,
+    purgeTokenIds        SET OF TokenId,
+    nonStandard          SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+PurgeTokensIndication ::= SEQUENCE
+{
+    purgeTokenIds        SET OF TokenId,
+    nonStandard          SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+-- Part 4: Disconnect provider
+
+DisconnectProviderUltimatum ::= SEQUENCE
+{
+    reason               Reason,
+    nonStandard          SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+RejectMCSPDUUltimatum ::= SEQUENCE
+{
+    diagnostic           Diagnostic,
+    initialOctets        OCTET STRING,
+    nonStandard          SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+-- Part 5: Attach/Detach user
+
+AttachUserRequest ::= SEQUENCE
+{
+    nonStandard          SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+AttachUserConfirm ::= SEQUENCE
+{
+    result               Result,
+    initiator            UserId OPTIONAL,
+    nonStandard          SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+```
+
+```
+
+DetachUserRequest ::= SEQUENCE
+{
+    reason                Reason,
+    userIds               SET OF UserId,
+    nonStandard           SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+```
+
+```
+
+DetachUserIndication ::= SEQUENCE
+{
+    reason                Reason,
+    userIds               SET OF UserId,
+    nonStandard           SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+```
+
+*-- Part 6: Channel management*
+
+```
+
+ChannelJoinRequest ::= SEQUENCE
+{
+    initiator             UserId,
+    channelId             ChannelId,      -- may be zero
+    nonStandard           SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+```
+
+```
+
+ChannelJoinConfirm ::= SEQUENCE
+{
+    result Result,
+    initiator             UserId,
+    requested             ChannelId,      -- may be zero
+    channelId             ChannelId OPTIONAL,
+    nonStandard           SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+```
+
+```
+
+ChannelLeaveRequest ::= SEQUENCE
+{
+    channelIds            SET OF ChannelId,
+    nonStandard           SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+```
+
+```
+
+ChannelConveneRequest ::= SEQUENCE
+{
+    initiator             UserId,
+    nonStandard           SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+```
+
+```
+
+ChannelConveneConfirm ::= SEQUENCE
+{
+    result                Result,
+    initiator             UserId,
+    channelId             PrivateChannelId OPTIONAL,
+    nonStandard           SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+```
+
+```
+
+ChannelDisbandRequest ::= SEQUENCE
+{
+    initiator                UserId,
+    channelId                PrivateChannelId,
+    nonStandard              SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+```
+
+```
+
+ChannelDisbandIndication ::= SEQUENCE
+{
+    channelId                PrivateChannelId,
+    nonStandard              SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+```
+
+```
+
+ChannelAdmitRequest ::= SEQUENCE
+{
+    initiator                UserId,
+    channelId                PrivateChannelId,
+    userIds                  SET OF UserId,
+    nonStandard              SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+```
+
+```
+
+ChannelAdmitIndication ::= SEQUENCE
+{
+    initiator                UserId,
+    channelId                PrivateChannelId,
+    userIds                  SET OF UserId,
+    nonStandard              SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+```
+
+```
+
+ChannelExpelRequest ::= SEQUENCE
+{
+    initiator                UserId,
+    channelId                PrivateChannelId,
+    userIds                  SET OF UserId,
+    nonStandard              SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+```
+
+```
+
+ChannelExpelIndication ::= SEQUENCE
+{
+    channelId                PrivateChannelId,
+    userIds                  SET OF UserId,
+    nonStandard              SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+```
+
+-- Part 7: Data transfer
+
+```
+
+SendDataRequest ::= SEQUENCE
+{
+    initiator                UserId,
+    channelId                ChannelId,
+    reliability              BOOLEAN,
+    domainReferenceID        INTEGER (0 .. 65535)    OPTIONAL,
+    dataPriority              DataPriority,
+    segmentation             Segmentation,
+    userData                  OCTET STRING,
+}
+
+```
+
+```
+
+        totalDataSize      INTEGER                OPTIONAL,
+        nonStandard        SEQUENCE OF NonStandardParameter OPTIONAL,
+        ...
+    }
+
+```
+
+**SendDataIndication ::= SEQUENCE**
+
+```
+
+{
+    initiator              UserId,
+    channelId              ChannelId,
+    reliability             BOOLEAN,
+    domainReferenceID      INTEGER (0 .. 65535)    OPTIONAL,
+    dataPriority            DataPriority,
+    segmentation           Segmentation,
+    userData               OCTET STRING,
+    totalDataSize          INTEGER                OPTIONAL,
+    nonStandard            SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+```
+
+**UniformSendDataRequest ::= SEQUENCE**
+
+```
+
+{
+    initiator              UserId,
+    channelId              ChannelId,
+    reliability             BOOLEAN,
+    domainReferenceID      INTEGER (0 .. 65535)    OPTIONAL,
+    dataPriority            DataPriority,
+    segmentation           Segmentation,
+    userData               OCTET STRING,
+    totalDataSize          INTEGER                OPTIONAL,
+    nonStandard            SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+```
+
+**UniformSendDataIndication ::= SEQUENCE**
+
+```
+
+{
+    initiator              UserId,
+    channelId              ChannelId,
+    reliability             BOOLEAN,
+    domainReferenceID      INTEGER (0 .. 65535)    OPTIONAL,
+    dataPriority            DataPriority,
+    segmentation           Segmentation,
+    userData               OCTET STRING,
+    totalDataSize          INTEGER                OPTIONAL,
+    nonStandard            SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+```
+
+*-- Part 8: Token management*
+
+**TokenGrabRequest ::= SEQUENCE**
+
+```
+
+{
+    initiator              UserId,
+    tokenId                TokenId,
+    nonStandard            SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+```
+
+```
+
+TokenGrabConfirm ::= SEQUENCE
+{
+    result                Result,
+    initiator              UserId,
+    tokenId                TokenId,
+    tokenStatus            TokenStatus,
+    nonStandard            SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+```
+
+```
+
+TokenInhibitRequest ::= SEQUENCE
+{
+    initiator              UserId,
+    tokenId                TokenId,
+    nonStandard            SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+```
+
+```
+
+TokenInhibitConfirm ::= SEQUENCE
+{
+    result                Result,
+    initiator              UserId,
+    tokenId                TokenId,
+    tokenStatus            TokenStatus,
+    nonStandard            SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+```
+
+```
+
+TokenGiveRequest ::= SEQUENCE
+{
+    initiator              UserId,
+    tokenId                TokenId,
+    recipient              UserId,
+    nonStandard            SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+```
+
+```
+
+TokenGiveIndication ::= SEQUENCE
+{
+    initiator              UserId,
+    tokenId                TokenId,
+    recipient              UserId,
+    nonStandard            SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+```
+
+```
+
+TokenGiveResponse ::= SEQUENCE
+{
+    result                Result,
+    recipient              UserId,
+    tokenId                TokenId,
+    nonStandard            SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+```
+
+```
+
+TokenGiveConfirm ::= SEQUENCE
+{
+    result                Result,
+    initiator              UserId,
+    tokenId                TokenId,
+    tokenStatus            TokenStatus,
+}
+
+```
+
+```
+
+        nonStandard          SEQUENCE OF NonStandardParameter OPTIONAL,
+        ...
+    }
+
+```
+
+**TokenPleaseRequest ::= SEQUENCE**
+
+```
+
+{
+    initiator          UserId,
+    tokenId            TokenId,
+    nonStandard        SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+```
+
+**TokenPleaseIndication ::= SEQUENCE**
+
+```
+
+{
+    initiator          UserId,
+    tokenId            TokenId,
+    nonStandard        SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+```
+
+**TokenReleaseRequest ::= SEQUENCE**
+
+```
+
+{
+    initiator          UserId,
+    tokenId            TokenId,
+    nonStandard        SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+```
+
+**TokenReleaseConfirm ::= SEQUENCE**
+
+```
+
+{
+    result             Result,
+    initiator          UserId,
+    tokenId            TokenId,
+    tokenStatus        TokenStatus,
+    nonStandard        SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+```
+
+**TokenTestRequest ::= SEQUENCE**
+
+```
+
+{
+    initiator          UserId,
+    tokenId            TokenId,
+    nonStandard        SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+```
+
+**TokenTestConfirm ::= SEQUENCE**
+
+```
+
+{
+    initiator          UserId,
+    tokenId            TokenId,
+    tokenStatus        TokenStatus,
+    nonStandard        SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+```
+
+*-- Part 9: Capabilities notification*
+
+**CapabilityID ::= CHOICE**
+
+```
+
+{
+    standardID         INTEGER (0 .. 65535),
+    nonstandardID      Key
+}
+
+```
+
+**CapabilityClass ::= CHOICE**
+
+```
+{
+    null                NULL,
+    unsignedMin          INTEGER (0 .. MAX),
+    unsignedMax          INTEGER (0 .. MAX)
+}
+```
+
+**ParticipationIndicator ::= CHOICE**
+
+```
+{
+    global                NULL,
+    partial              INTEGER (1 .. 2)
+}
+```
+
+**RequestCapability ::= SEQUENCE**
+
+```
+{
+    capabilityID          CapabilityID,
+    capabilityClass       CapabilityClass,
+    participationIndicator ParticipationIndicator,
+    nonStandard           SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+```
+
+**SeqOfRequestCapabilities ::= SEQUENCE OF RequestCapability**
+
+**IndicationCapability ::= SEQUENCE**
+
+```
+{
+    capabilityID          CapabilityID,
+    capabilityClass       CapabilityClass,
+    summitProviderSupported BOOLEAN,
+    intermediateNodeSupported BOOLEAN,
+    nonStandard           SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+```
+
+**SeqOfIndicationCapabilities ::= SEQUENCE OF IndicationCapability**
+
+**CapabilitiesNotificationRequest ::= SEQUENCE**
+
+```
+{
+    v2NodePresent        BOOLEAN,
+    addList               SeqOfRequestCapabilities OPTIONAL,
+    removeList            SeqOfRequestCapabilities OPTIONAL,
+    nonStandard           SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+```
+
+**CapabilitiesNotificationIndication ::= SEQUENCE**
+
+```
+{
+    v2NodePresent        BOOLEAN,
+    addList               SeqOfIndicationCapabilities OPTIONAL,
+    removeList            SeqOfIndicationCapabilities OPTIONAL,
+    nonStandard           SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+```
+
+-- Part 10: Status codes
+
+**Reason ::= CHOICE**     -- in *DisconnectProviderUltimatum, DetachUserRequest, DetachUserIndication*
+
+```
+{
+    rn-domain-disconnected      NULL,
+    rn-provider-initiated        NULL,
+    rn-token-purged              NULL,
+    rn-user-requested            NULL,
+    rn-channel-purged            NULL,
+    ...
+}
+```
+
+**Result ::= CHOICE**     -- in *Connect, response, confirm*
+
+```
+{
+    rt-successful                NULL,
+    rt-domain-merging            NULL,
+    rt-domain-not-hierarchical   NULL,
+    rt-no-such-channel           NULL,
+    rt-no-such-domain            NULL,
+    rt-no-such-user              NULL,
+    rt-not-admitted              NULL,
+    rt-other-user-id             NULL,
+    rt-parameters-unacceptable   NULL,
+    rt-token-not-available        NULL,
+    rt-token-not-possessed        NULL,
+    rt-too-many-channels          NULL,
+    rt-too-many-tokens           NULL,
+    rt-too-many-users            NULL,
+    rt-unspecified-failure        NULL,
+    rt-user-rejected             NULL,
+    ...
+}
+```
+
+**Diagnostic ::= CHOICE**   -- in *RejectMCSPDUUltimatum*
+
+```
+{
+    dc-inconsistent-merge        NULL,
+    dc-forbidden-PDU-downward    NULL,
+    dc-forbidden-PDU-upward      NULL,
+    dc-invalid-BER-encoding       NULL,
+    dc-invalid-PER-encoding       NULL,
+    dc-misrouted-user            NULL,
+    dc-unrequested-confirm        NULL,
+    dc-wrong-transport-priority   NULL,
+    dc-channel-id-conflict        NULL,
+    dc-token-id-conflict          NULL,
+    dc-not-user-id-channel        NULL,
+    dc-too-many-channels          NULL,
+    dc-too-many-tokens            NULL,
+    dc-too-many-users             NULL,
+    ...
+}
+```
+
+-- Part 11: MCSPDU repertoire
+
+**NonStandardPDU ::= SEQUENCE**
+
+```
+{
+    data                          NonStandardParameter,
+    ...
+}
+```
+
+**ExtendedParameterMCSPDU ::= CHOICE**
+
+```
+{
+    extendedParameterPropose      ExtendedParameterPropose,
+    extendedParameterAcceptExtendedParameterAccept,
+    nonStandard                    NonStandardPDU,
+    ...
+}
+```
+
+**DomainMCSPDU ::= CHOICE**
+
+```
+{
+    plumbDomainIndication          PlumbDomainIndication,
+    erectDomainRequest             ErectDomainRequest,
+    mergeChannelsRequest           MergeChannelsRequest,
+    mergeChannelsConfirm           MergeChannelsConfirm,
+    purgeChannelsIndication        PurgeChannelsIndication,
+    mergeTokensRequest             MergeTokensRequest,
+    mergeTokensConfirm             MergeTokensConfirm,
+    purgeTokensIndication          PurgeTokensIndication,
+    disconnectProviderUltimatum    DisconnectProviderUltimatum,
+    rejectMCSPDUUltimatum          RejectMCSPDUUltimatum,
+    attachUserRequest              AttachUserRequest,
+    attachUserConfirm              AttachUserConfirm,
+    detachUserRequest              DetachUserRequest,
+    detachUserIndication           DetachUserIndication,
+    channelJoinRequest             ChannelJoinRequest,
+    channelJoinConfirm             ChannelJoinConfirm,
+    channelLeaveRequest             ChannelLeaveRequest,
+    channelConveneRequest          ChannelConveneRequest,
+    channelConveneConfirm          ChannelConveneConfirm,
+    channelDisbandRequest          ChannelDisbandRequest,
+    channelDisbandIndication       ChannelDisbandIndication,
+    channelAdmitRequest            ChannelAdmitRequest,
+    channelAdmitIndication         ChannelAdmitIndication,
+    channelExpelRequest            ChannelExpelRequest,
+    channelExpelIndication         ChannelExpelIndication,
+    sendDataRequest               SendDataRequest,
+    sendDataIndication             SendDataIndication,
+    uniformSendDataRequest         UniformSendDataRequest,
+    uniformSendDataIndication      UniformSendDataIndication,
+    tokenGrabRequest               TokenGrabRequest,
+    tokenGrabConfirm               TokenGrabConfirm,
+    tokenInhibitRequest            TokenInhibitRequest,
+    tokenInhibitConfirm            TokenInhibitConfirm,
+    tokenGiveRequest               TokenGiveRequest,
+    tokenGiveIndication            TokenGiveIndication,
+    tokenGiveResponse              TokenGiveResponse,
+    tokenGiveConfirm               TokenGiveConfirm,
+    tokenPleaseRequest              TokenPleaseRequest,
+    tokenPleaseIndication           TokenPleaseIndication,
+    tokenReleaseRequest            TokenReleaseRequest,
+    tokenReleaseConfirm            TokenReleaseConfirm,
+    tokenTestRequest               TokenTestRequest,
+    tokenTestConfirm               TokenTestConfirm,
+    nonStandard                    NonStandardPDU,
+    ...
+}
+```
+
+**END**
+
+# 9 Encoding of MCSPDUs
+
+Each MCSPDU is transported as one TSDU across a TC belonging to an MCS connection. Connect MCSPDUs are unlimited in size. Domain MCSPDUs are limited in size by a parameter of the MCS domain.
+
+A standard ASN.1 data value encoding is used to transfer MCSPDUs between peer MCS providers. Encoding rules are selected as part of protocol version negotiation. This negotiation involves the exchange of a **Connect-Initial** and a **Connect-Response** MCSPDU over the initial TC. Three versions of this protocol are defined:
+
+- *Version 1* – All MCSPDUs are described in clause 7 and use the Basic Encoding Rules of Recommendation X.690.
+- *Version 2* – All MCSPDUs are described in clause 7. This version uses Basic Encoding Rules for connect MCSPDUs and the Packed Encoding Rules of Recommendation X.691 for all subsequent domain MCSPDUs. Specifically, the ALIGNED variant of BASIC-PER shall be applied to the ASN.1 type **DomainMCSPDU**. The bit string produced shall be conveyed as an integral number of octets. The leading bit of this string shall coincide with the most significant bit of the first octet.
+- *Version 3* – Connect MCSPDUs are described in clause 7 and use Basic Encoding Rules for backward compatibility with Version 2. Extended Parameters and Domain MCSPDUs are described in clause 8 and use Packed Encoding Rules as specified for Version 2, above. Version 3 enabled nodes must be able to translate version 3 protocol into version 2 protocol for transmission over a connection to a node which has specified version 2 protocol in the domain parameters. This translation is described in 13.11.
+
+NOTE 1 – The Packed Encoding Rules yield more compact MCSPDU headers.
+
+NOTE 2 – Both BER and PER are self-delimiting, in the sense that they contain enough information to locate the end of each encoded MCSPDU. It might be argued that this makes the use of TSDUs unnecessary and that this protocol could be implemented over non-standard transport services that convey octet streams without preserving TSDU boundaries. However, such an approach is more vulnerable to implementation errors. If the boundary between MCSPDUs were ever lost, recovery would be difficult.
+
+# 10 Routing of MCSPDUs
+
+## 10.1 Connect and extended parameters MCSPDUs
+
+Figures 10-1 and 10-2 specify the exchange of connect and extended parameters MCSPDUs (the number and relative order of additional TCs may vary).
+
+With the receipt of a **Connect-Response**, the calling MCS provider will determine if the new connection is between two members of the V3 summit by examining the negotiated version number. If so, it will initiate the exchange of the **Extended-Parameters** MCSPDUs. If either node is not a member of the V3 summit, the calling provider will not issue an **Extended-Parameters-Propose**, but will proceed with **Connect-Additional** MCSPDUs.
+
+After receiving the **Connect-Response**, the calling MCS provider also learns the negotiated value for the number of data transfer priorities implemented in the domain. For illustration, connect MCSPDUs on additional TCs are shown obeying the strict sequence 2, 3, 4 at the called MCS provider. In reality, transport connections may not be established in the same order that they are requested. Indeed, a **Connect-Additional** may arrive in a different order than it was sent, causing a **Connect-Result** to be returned out of sequence too. Or the latter, even if sent in sequence, may still be reordered in transit. A calling MCS provider need not wait for all additional TCs to be established
+
+before sending the first **Connect-Additional**. The called MCS provider need not wait for a full set of **Connect-Additional** MCSPDUs to arrive before returning the first **Connect-Result**. Receipt of a full set of successful results at the calling MCS provider, in whatever order, generates a successful MCS-CONNECT-PROVIDER confirm.
+
+An unsuccessful **Connect-Response** or **Connect-Result** or a T-DISCONNECT indication at some intermediate point shall cause all TCs belonging to the MCS connection so far to be disconnected and shall generate an unsuccessful MCS-CONNECT-PROVIDER confirm.
+
+An MCS-CONNECT-PROVIDER request specifies which of two MCS providers is higher than the other. This hierarchical relationship determines the subsequent routing of domain MCSPDUs, and the distinction between calling and called MCS provider is thereafter irrelevant. For example, a next step is for the MCS layer to merge the resources of two previously independent domains. **MergeChannelsRequest** and **MergeTokensRequest** are generated by the lower MCS provider and are transmitted across the new MCS connection to the higher MCS provider. The direction in which these MCSPDUs are sent could be either calling-to-called or called-to-calling, depending on how the upward flag was set.
+
+![Sequence diagram showing message flow between Calling Provider and Called Provider for MCS connection establishment and extended parameters.](a003ffe7299e0a48bceb7f1e45a4f1a3_img.jpg)
+
+```
+
+sequenceDiagram
+    participant CP as Calling Provider
+    participant CDP as Called Provider
+    Note left of CP: MCS-CONNECT-PROVIDER request
+    CP->>CDP: Connect-Initial
+    Note right of CDP: MCS-CONNECT-PROVIDER indication
+    CDP->>CP: Connect-Response
+    Note left of CP: TC 1
+    CP->>CDP: Extended-Parameters-Propose
+    Note right of CDP: TC 1
+    CDP->>CP: Extended-Parameters-Accept
+    Note left of CP: TC 1
+    CP->>CDP: Connect-Additional
+    Note right of CDP: TC 2
+    CP->>CDP: Connect-Additional
+    Note right of CDP: TC 3
+    CP->>CDP: Connect-Additional
+    Note right of CDP: TC 4
+    CDP->>CP: Connect-Result
+    Note left of CP: TC 2
+    CDP->>CP: Connect-Result
+    Note left of CP: TC 3
+    CDP->>CP: Connect-Result
+    Note left of CP: TC 4
+    Note left of CP: MCS-CONNECT-PROVIDER confirm
+    
+```
+
+The diagram illustrates the message flow between a Calling Provider and a Called Provider. The sequence begins with an external 'MCS-CONNECT-PROVIDER request' to the Calling Provider, which sends a 'Connect-Initial' message to the Called Provider. The Called Provider then sends an 'MCS-CONNECT-PROVIDER indication' and a 'Connect-Response' back to the Calling Provider. This is followed by an 'Extended-Parameters-Propose' message from the Calling Provider to the Called Provider, which responds with 'Extended-Parameters-Accept'. The Calling Provider then sends multiple 'Connect-Additional' messages (labeled TC 1, TC 2, TC 3, TC 4) to the Called Provider. The Called Provider responds with 'Connect-Result' messages (labeled TC 2, TC 3, TC 4) back to the Calling Provider. Finally, the Calling Provider receives an 'MCS-CONNECT-PROVIDER confirm' message.
+
+Sequence diagram showing message flow between Calling Provider and Called Provider for MCS connection establishment and extended parameters.
+
+T1602430-97
+
+**Figure 10-1/T.125 – Message flow of connect and extended parameters MCSPDUs between member nodes of the V3 Summit**
+
+![Sequence diagram showing message flow of connect MCSPDUs between Calling Provider and Called Provider. The flow includes Connect-Initial, Connect-Response, Connect-Additional, and Connect-Result messages, with TC 1 through TC 4 labels indicating specific transaction contexts. External messages include MCS-CONNECT-PROVIDER request, indication, response, and confirm.](12c19090355e19922e23044633b9d1ea_img.jpg)
+
+```
+
+sequenceDiagram
+    participant CP as Calling Provider
+    participant CDP as Called Provider
+    Note left of CP: MCS-CONNECT-PROVIDER request
+    CP->>CP: TC 1
+    CP->>CDP: Connect-Initial
+    Note right of CDP: MCS-CONNECT-PROVIDER indication
+    CDP->>CDP: TC 1
+    CDP->>CP: Connect-Response
+    CP->>CDP: Connect-Additional
+    CP->>CDP: Connect-Additional
+    CP->>CDP: Connect-Additional
+    CP->>CDP: Connect-Additional
+    CDP->>CP: Connect-Result
+    CDP->>CP: Connect-Result
+    CDP->>CP: Connect-Result
+    Note left of CP: MCS-CONNECT-PROVIDER confirm
+    Note right of CDP: TC 2, TC 3, TC 4
+  
+```
+
+Sequence diagram showing message flow of connect MCSPDUs between Calling Provider and Called Provider. The flow includes Connect-Initial, Connect-Response, Connect-Additional, and Connect-Result messages, with TC 1 through TC 4 labels indicating specific transaction contexts. External messages include MCS-CONNECT-PROVIDER request, indication, response, and confirm.
+
+T1602440-97
+
+**Figure 10-2/T.125 – Message flow of connect MCSPDUs between nodes that are not both members of the V3 Summit**
+
+## 10.2 Domain MCSPDUs
+
+Table 10-1 specifies the routing of domain MCSPDUs.
+
+If an MCS provider generates or forwards an MCSPDU of category *request*, it travels over the unique MCS connection upward. **ErectDomainRequest**, **ChannelJoinRequest**, **ChannelLeaveRequest**, and **CapabilitiesNotificationRequest** may be consumed at some intermediate MCS provider. Other requests rise to be acted on by the top MCS provider, unless the content of a request is determined to be invalid, in which case its MCSPDU may be ignored, without confirmation.
+
+Table 10-1/T.125 – Routing of domain MCSPDUs
+
+| Category   | MCSPDUs                                   | TC | Direction |
+|------------|-------------------------------------------|----|-----------|
+| Request    | <b>ErectDomainRequest</b>                 | I  | Up        |
+|            | <b>MergeChannelsRequest</b>               |    |           |
+|            | <b>MergeTokensRequest</b>                 |    |           |
+|            | <b>AttachUserRequest</b>                  |    |           |
+|            | <b>DetachUserRequest</b>                  |    |           |
+|            | <b>ChannelJoinRequest</b>                 |    |           |
+|            | <b>ChannelLeaveRequest</b>                |    |           |
+|            | <b>ChannelConveneRequest</b>              |    |           |
+|            | <b>ChannelDisbandRequest</b>              |    |           |
+|            | <b>ChannelAdmitRequest</b>                |    |           |
+|            | <b>ChannelExpelRequest</b>                |    |           |
+|            | <b>TokenGrabRequest</b>                   |    |           |
+|            | <b>TokenInhibitRequest</b>                |    |           |
+|            | <b>TokenGiveRequest</b>                   |    |           |
+|            | <b>TokenPleaseRequest</b>                 |    |           |
+|            | <b>TokenReleaseRequest</b>                |    |           |
+|            | <b>TokenTestRequest</b>                   |    |           |
+|            | <b>CapabilitiesNotificationRequest</b>    |    |           |
+|            | <b>SendDataRequest</b>                    | A  |           |
+|            | <b>UniformSendDataRequest</b>             |    |           |
+| Indication | <b>PlumbDomainIndication</b>              | I  | Down      |
+|            | <b>PurgeChannelsIndication</b>            |    |           |
+|            | <b>PurgeTokensIndication</b>              |    |           |
+|            | <b>DetachUserIndication</b>               |    |           |
+|            | <b>ChannelDisbandIndication</b>           |    |           |
+|            | <b>ChannelAdmitIndication</b>             |    |           |
+|            | <b>ChannelExpelIndication</b>             |    |           |
+|            | <b>TokenGiveIndication</b>                |    |           |
+|            | <b>TokenPleaseIndication</b>              |    |           |
+|            | <b>CapabilitiesNotificationIndication</b> |    |           |
+|            | <b>SendDataIndication</b>                 | A  |           |
+|            | <b>UniformSendDataIndication</b>          |    |           |
+
+If an MCS provider generates or forwards an MCSPDU of category *indication*, copies of it, possibly amended in content, travel over zero or more MCS connections downward, according to the following rules:
+
+- a) **PlumbDomainIndication** is sent on all MCS connections downward. The height limit it contains is decremented by one. An MCS provider receiving this MCSPDU with a height limit of zero shall disconnect.
+
+- b) **PurgeChannelsIndication** is sent on all MCS connections downward. The set of user ids forwarded is unchanged, so that all detached users will be announced to those that remain. The set of other channel ids forwarded may be restricted to those in use in a subtree. At a former top provider that is still merging into an upper domain, both user ids and other channel ids are restricted to those whose acceptance into the upper domain has been confirmed.
+- c) **PurgeTokensIndication** is sent on all MCS connections downward. The set of token ids forwarded may be restricted to those in use in a subtree. At a former top provider that is still merging into an upper domain, token ids are restricted to those whose acceptance into the upper domain has been confirmed.
+- d) **DetachUserIndication** is sent on all MCS connections downward. The set of user ids forwarded is unchanged, so that all detached users will be announced to those that remain. At a former top provider that is still merging into an upper domain, user ids are restricted to those whose acceptance into the upper domain has been confirmed.
+- e) **ChannelDisbandIndication** is sent on all MCS connections downward that contain in their subtree the manager of the private channel or any admitted user.
+- f) **ChannelAdmitIndication** and **ChannelExpelIndication** are sent on all MCS connections downward that contain one or more of the affected users in their subtree. The set of user ids forwarded may be restricted to those residing in a subtree.
+- g) **TokenGiveIndication** is sent on a single MCS connection downward that contains the designated recipient in its subtree.
+- h) **TokenPleaseIndication** is sent on all MCS connections downward that contain in their subtree a user who has grabbed, inhibited, or is being given the token.
+- i) **CapabilitiesNotificationIndication** is sent on all MCS connections downward in the V3 summit. Each node receiving this MCSPDU alters its local copy of the V3 summit capabilities list based on the contents of the Add List and Remove List.
+- j) **SendDataIndication** and **UniformSendDataIndication** are sent on all MCS connections downward by which the specified channel is joined, except that when **SendDataIndication** is generated, it is not sent back on the connection by which **SendDataRequest** arrived.
+
+Indications **PurgeChannelsIndication**, **PurgeTokensIndication**, **DetachUserIndication**, **ChannelAdmitIndication**, and **ChannelExpelIndication** need not be forwarded if the sets of ids they contain are empty.
+
+If an MCS provider generates or forwards an MCSPDU of category *response*, it travels over the unique MCS connection upward. It rises to be acted on by the top MCS provider, unless its content is determined to be invalid.
+
+If an MCS provider generates or forwards an MCSPDU of category *confirm*, it travels over a single MCS connection downward, according to the following rules.
+
+- a) **MergeChannelsConfirm** retraces, in the opposite direction, the path of the earliest **MergeChannelsRequest** that has not yet been answered by a confirm. This requires each MCS provider to maintain a first-in first-out queue of pending requests.
+- b) **MergeTokensConfirm** retraces, in the opposite direction, the path of the earliest **MergeTokensRequest** that has not yet been answered by a confirm. This requires each MCS provider to maintain a first-in first-out queue of pending requests.
+
+- c) **AttachUserConfirm** retraces, in the opposite direction, the path of an earlier **AttachUserRequest** that has not yet been answered by a confirm. It is not critical which **AttachUserRequest**, if more than one is pending, but to be fair each MCS provider should maintain a first-in first-out queue. Upon sending **AttachUserConfirm**, an MCS provider shall record to which subtree the user id it contains is thereby being assigned.
+- d) Other MCSPDUs of category confirm contain an initiator user id that was previously assigned through the action of **AttachUserConfirm** as just explained. These MCSPDUs are sent on the MCS connection downward that leads to the subtree where the user id was assigned. Continuing in this way, they eventually return to the provider that hosts the requesting MCS attachment.
+
+Confirms are generated in the course of processing like requests. All but **ChannelJoinConfirm** are generated by the top MCS provider.
+
+If an MCS provider generates an MCSPDU of category *ultimatum*, it travels over a single MCS connection, either upward or downward. **DisconnectProviderUltimatum** commands the receiving MCS provider to disconnect the MCS connection that conveys it. **RejectMCSPDUUltimatum** rejects an erroneous MCSPDU with a diagnostic code and invites the MCS provider that transmitted it to disconnect. Ultimatums are not forwarded.
+
+# 11 Meaning of MCSPDUs
+
+Tables 11-1 through 11-51 reiterate the contents of individual MCSPDUs as defined in clause 8.
+
+## 11.1 Connect-Initial
+
+**Connect-Initial** is generated by an MCS-CONNECT-PROVIDER request. It is sent as the first TSDU over the initial TC of a new MCS connection. At the receiver, it generates an MCS-CONNECT-PROVIDER indication.
+
+**Table 11-1/T.125 – Connect-Initial MCSPDU**
+
+| Contents                  | Source  | Sink       |
+|---------------------------|---------|------------|
+| Calling Domain Selector   | Request | Indication |
+| Called Domain Selector    | Request | Indication |
+| Upward Flag               | Request | Indication |
+| Target Domain Parameters  | Request | Indication |
+| Minimum Domain Parameters | Request | Indication |
+| Maximum Domain Parameters | Request | Indication |
+| User Data                 | Request | Indication |
+
+Calling transport address and called transport address are additional parameters of the MCS-CONNECT-PROVIDER request and indication. They become parameters of T-CONNECT and are not passed explicitly in any MCSPDU. The same pair of transport addresses shall be used to request all TCs belonging to the same MCS connection.
+
+Transport quality of service is an additional parameter of the MCS-CONNECT-PROVIDER request but not of the indication. Quality of service can vary from one TC to another, and the quality available is only disclosed in the process of establishing a given TC. Since the number of additional
+
+TCs needed is not known until MCS-CONNECT-PROVIDER has negotiated the domain parameter for number of data priorities implemented, this primitive cannot at the same time fully negotiate their transport quality of service. A called MCS provider shall therefore accept incoming TCs automatically at the offered quality of service, so long as this meets any minimum optionally specified by the calling MCS provider and indicated through each individual T-CONNECT.
+
+The interpretation of domain selector values is a local matter for each MCS provider. These are octet strings that have the characteristics of an address. Acceptable values may be determined through the process of configuring an MCS provider. More than one value may select the same domain. An unspecified domain selector is an octet string of length zero. This may be resolved, through local convention, to some explicit value.
+
+The upward flag specifies the direction of a new MCS connection: true if the called provider is to be considered higher than the calling provider and false otherwise. An MCS provider plays a role in the hierarchy of a domain based on the direction of MCS connections in which it participates. No provider shall allow two connections to higher providers. A provider without a connection to a higher provider shall act as top MCS provider.
+
+The target domain parameters of **Connect-Initial** individually shall lie between the minimum and maximum values specified. An MCS provider shall revise the requested domain parameters to reflect limits of its implementation or to impose values already agreed among the existing members of a domain. It may increase the minimums and decrease the maximums. It shall change targets only to keep them within the interval. An MCS provider should be prepared to honour any response that falls within the range of values it proposes.
+
+User data is an arbitrary octet string. It may have length zero.
+
+An MCS provider automatically accepts each incoming TC to the limit of its capacity. User data in T-CONNECT is unused. The first TSDU received in data transfer, being either a **Connect-Initial** or a **Connect-Additional** MCSPDU, determines the nature of the TC. If the content is unacceptable, a called MCS provider may disconnect the TC immediately. The preferred reaction is to return a **Connect-Response** or **Connect-Result**, as the case may be, explaining why the MCS connection failed. The calling MCS provider shall then disconnect.
+
+## 11.2 Connect-Response
+
+**Connect-Response** is generated by an MCS-CONNECT-PROVIDER response. It is the first TSDU sent in reverse over the initial TC of a new MCS connection. It conveys the acceptance of an MCS connection to the calling MCS provider, which then proceeds to establish any additional TCs required.
+
+**Table 11-2/T.125 – Connect-Response MCSPDU**
+
+| Contents          | Source          | Sink             |
+|-------------------|-----------------|------------------|
+| Result            | Response        | Confirm          |
+| Domain Parameters | Response        | Confirm          |
+| Called Connect Id | Called provider | Calling provider |
+| User Data         | Response        | Confirm          |
+
+If the result is successful, this MCSPDU fixes the domain parameters in effect. Among these is the number of MCS data transfer priorities implemented, equal to the number of TCs in an MCS
+
+connection. If this exceeds one, additional TCs shall be created and bound to the MCS connection through the exchange of **Connect-Additional** and **Connect-Result** MCSPDUs.
+
+The called connect id serves as the means for associating additional incoming TCs at the called MCS provider with this initial TC. Its value is chosen for this purpose alone. It shall uniquely identify one MCS connection in progress at the called provider. This id has no lasting significance following the completion of MCS-CONNECT-PROVIDER.
+
+Most of the parameters of MCS-CONNECT-PROVIDER confirm are conveyed in **Connect-Response**. If the result is unsuccessful or no additional TCs are needed, confirm is generated immediately. Otherwise, it is deferred until the results are known for binding additional TCs to the MCS connection.
+
+## 11.3 Connect-Additional
+
+If the calling MCS provider determines that both providers are members of the V3 summit, **Connect-Additional** is generated following receipt of **Extended-Parameters-Accept**, otherwise it will be generated following receipt of **Connect-Response**. It is sent as the first TSDU over an additional TC of a new MCS connection.
+
+Data priority takes on the values *high*, *medium*, and *low* in sequence, up to the number of additional TCs required.
+
+**Table 11-3/T.125 – Connect-Additional MCSPDU**
+
+| Contents          | Source           | Sink            |
+|-------------------|------------------|-----------------|
+| Called Connect Id | Calling provider | Called provider |
+| Data Priority     | Calling provider | Called provider |
+
+## 11.4 Connect-Result
+
+**Connect-Result** is generated following receipt of **Connect-Additional**. It is the first TSDU sent in reverse over an additional TC of a new MCS connection.
+
+**Table 11-4/T.125 – Connect-Result MCSPDU**
+
+| Contents | Source          | Sink    |
+|----------|-----------------|---------|
+| Result   | Called provider | Confirm |
+
+If any result is unsuccessful, MCS-CONNECT-PROVIDER confirm shall be generated immediately. All TCs associated with the MCS connection shall be disconnected and any MCSPDUs they convey shall be ignored.
+
+Otherwise, successful results shall be awaited for each additional TC. These may return out-of-sequence. When all have been collected, a successful MCS-CONNECT-PROVIDER confirm shall be generated.
+
+After MCS-CONNECT-PROVIDER confirm, domain MCSPDUs may flow across an MCS connection. Each MCS connection belongs to a single domain. In configurations where an MCS provider hosts more than one domain, the MCS connection that carries MCSPDUs determines which domain they apply to. The descriptions of domain MCSPDUs that occupy the remainder of this subclause are set in the context of a single domain.
+
+## 11.5 Extended-Parameters-Propose
+
+Following the receipt of **Connect-Response**, if the calling MCS provider determines that both providers are members of the V3 summit, **Extended-Parameters-Propose** is generated. It is sent over the initial TC of a new MCS connection.
+
+**Table 11-5/T.125 – Extended-Parameters-Propose MCSPDU**
+
+| Contents                    | Source           | Sink            |
+|-----------------------------|------------------|-----------------|
+| Target Extended Parameters  | Calling provider | Called provider |
+| Minimum Extended Parameters | Calling provider | Called provider |
+| Maximum Extended Parameters | Calling provider | Called provider |
+
+For extended parameters with a range of possible values, the target parameters of **Extended-Parameters-Propose** individually shall lie between the minimum and maximum values specified. An MCS provider shall revise the requested extended parameters to reflect limits of its implementation or to impose values already agreed among the existing members of a domain. It may increase the minimums and decrease the maximums. It shall change targets only to keep them within the interval. An MCS provider should be prepared to honour any accepted target that falls within the range of values it proposes. If the extended parameters are unacceptable, a called MCS provider will disconnect the TC immediately.
+
+For the *Unreliable data is supported* value, if the calling provider wishes to allow the value to be negotiated, the Minimum value will be False, the Maximum value will be True and the target value will indicate the caller's preference. If support of unreliable data is nonnegotiable, Target, Minimum and Maximum will be set to the callers preference.
+
+The value for *Domain Reference Identifier* will be identical for Target, Minimum and Maximum and will uniquely identify this domain to the calling provider. The called provider may use this value to refer to this domain to the calling provider.
+
+## 11.6 Extended-Parameters-Accept
+
+**Extended-Parameters-Accept** is generated following receipt of **Extended-Parameters-Propose**. It conveys the acceptance of the extended parameter values to the calling MCS provider, which then proceeds to establish any additional TCs required.
+
+**Table 11-6/T.125 – Extended-Parameters-Accept MCSPDU**
+
+| Contents            | Source          | Sink             |
+|---------------------|-----------------|------------------|
+| Extended Parameters | Called provider | Calling provider |
+
+The value for *Domain Reference Identifier* will be identical for Target, Minimum and Maximum and will uniquely identify this domain to the called provider. The calling provider may use this value to refer to this domain to the called provider.
+
+## 11.7 PlumbDomainIndication
+
+**PlumbDomainIndication** is generated following the successful completion of MCS-CONNECT-PROVIDER. It plumbs the hierarchy of MCS providers below a new MCS connection to ensure that
+
+no cycle has been created. **PlumbDomainIndication** is also generated by the top MCS provider to enforce the maximum height of a domain.
+
+**Table 11-7/T.125 – PlumbDomainIndication MCSPDU**
+
+| Contents     | Source            | Sink         |
+|--------------|-------------------|--------------|
+| Height Limit | Former top or top | Subordinates |
+
+**PlumbDomainIndication** is generated at the lower end of a new MCS connection, by the provider that has ceased to be top of a domain. Its content is initialized to the domain parameter for the maximum height of the domain. **PlumbDomainIndication** is transmitted over all MCS connections downward.
+
+As needed, **PlumbDomainIndication** is generated in the same way at the top MCS provider.
+
+Wherever **PlumbDomainIndication** is received, the height limit it contains is inspected. If greater than zero, the limit is decremented by one and **PlumbDomainIndication** is forwarded over all MCS connections downward. A value of zero, on the other hand, means that the receiver lies too far from the top provider. It shall react by disconnecting the MCS connection upward. This deletes an entire subtree and helps to repair the height of the domain.
+
+In the presence of a cycle, the height limit of **PlumbDomainIndication** must decrease until it reaches zero. The provider that detects this will break the cycle, at the expense of deleting all providers in the cycle and their subordinates from the domain.
+
+NOTE – An MCS provider, with purely local knowledge of MCS connections, cannot prevent the creation of cycles. It can ensure that there is at most one connection upward at all times, but it cannot ensure that the upward connection does not loop back to some provider below. When a cycle is created, the immediate cause is a faulty upward connection from the top MCS provider. Controller applications, which specify the MCS connections to be created, must strive to avoid such errors.
+
+## 11.8 ErectDomainRequest
+
+**ErectDomainRequest** is generated following the successful completion of MCS-CONNECT-PROVIDER. It communicates upward changes in the height of providers and their throughput enforcement intervals. **ErectDomainRequest** is generated by an MCS provider whenever its height or interval changes.
+
+The height of an MCS provider may change when an MCS connection is added or dropped or when a subordinate provider reports a change through **ErectDomainRequest**. Its monitoring interval to enforce the minimum throughput specified as a domain parameter may change by adapting to the intervals reported by subordinates or for other reasons. If either value changes, an MCS provider shall transmit **ErectDomainRequest** to its immediate superior.
+
+**Table 11-8/T.125 – ErectDomainRequest MCSPDU**
+
+| Contents                        | Source      | Sink            |
+|---------------------------------|-------------|-----------------|
+| Height in Domain                | Subordinate | Higher provider |
+| Throughput Enforcement Interval | Subordinate | Higher provider |
+
+## 11.9 MergeChannelsRequest
+
+**MergeChannelsRequest** is generated following the successful completion of MCS-CONNECT-PROVIDER. It communicates upward the attributes of channels held by a former top provider so that they may be incorporated into the merged domain.
+
+**Table 11-9/T.125 – MergeChannelsRequest MCSPDU**
+
+| Contents          | Source        | Sink         |
+|-------------------|---------------|--------------|
+| Merge Channels    | Former top    | Top provider |
+| Purge Channel Ids | Intermediates | Top provider |
+
+**MergeChannelsRequest** may be filled with the attributes of multiple channels, up to the domain limit on MCSPDU size. As detailed in the ASN.1 definitions of clause 7, each of the four kinds of channel in use (static, user id, private, assigned) has its relevant set of attributes. These are held in the information base of the top MCS provider and are partially replicated into the subtrees where a channel is used. When two domains are merged, through the action of MCS-CONNECT-PROVIDER, channels that are in use in the lower domain must either be incorporated into the information base of the upper domain or be purged from the lower domain. This decision rests with the top provider of the merged domain.
+
+Each channel shall be considered individually. If the domain limits on channels in use allow it and the channel id has not already been put to some conflicting use, the upper domain shall expand to include it. The use of a static channel id is never a conflict. The use of a private channel id in the lower domain is not a conflict if it is also used as a private channel id in the upper domain and has the same user id as manager. All other combinations of simultaneous use are disallowed, requiring the channel id to be purged from the lower domain.
+
+If a private channel has a large set of admitted users, its attributes may not fit into a single **MergeChannelsRequest** and shall be sent upward in multiple MCSPDUs. However, the second and succeeding requests to merge the same private channel shall be delayed until a **MergeChannelsConfirm** has been received in reply to the first. Only then is it known if domain limits have allowed the channel to be put into use in the upper domain. If the first request fails, it shall not be repeated with a remaining subset of admitted users.
+
+Each **MergeChannelsRequest** elicits a **MergeChannelsConfirm** reply from the top MCS provider, in the same sequence. A **MergeChannelsConfirm** contains nothing that explicitly identifies the preceding **MergeChannelsRequest**. Replies shall be routed solely by the order in which these MCSPDUs are received. MCS providers above the former top shall make a record of each unanswered **MergeChannelsRequest** and whence it arrived, so that the corresponding **MergeChannelsConfirm** may be returned via the same MCS connection.
+
+Intermediate MCS providers shall validate the user ids proclaimed in private channel attributes, to ensure that they are legitimately assigned to the subtree where the **MergeChannelsRequest** originates. Invalid user ids shall be deleted. If the manager of a private channel is deleted, all of the channel attributes shall be deleted from the merge request and the channel id alone shall be included in the set to be purged. Except for this validation of user ids, intermediate MCS providers shall not modify the contents of a **MergeChannelsRequest**.
+
+A former top provider shall await individual confirmation that all user ids and all token ids have been incorporated into a merged domain or purged before it begins to submit static, assigned, or private channel attributes for merger.
+
+## 11.10 MergeChannelsConfirm
+
+**MergeChannelsConfirm** replies to a preceding **MergeChannelsRequest**. It reflects the same set of channel ids and a subset of the attributes. Channel attributes not incorporated into the merged domain are reported as channel ids to be purged.
+
+Accepted channel ids are reflected with the attributes that were entered into the information base of the top MCS provider. Intermediate providers shall update their information base to conform.
+
+**Table 11-10/T.125 – MergeChannelsConfirm MCSPDU**
+
+| Contents          | Source       | Sink          |
+|-------------------|--------------|---------------|
+| Merge Channels    | Top provider | Intermediates |
+| Purge Channel Ids | Top provider | Former top    |
+
+Channels to be purged from the lower domain are listed by id only. If the same channel ids are used in the upper domain, they are left undisturbed. Intermediate providers shall forward purged channel ids without acting on them.
+
+MCS providers shall route **MergeChannelsConfirm** to the source of the antecedent **MergeChannelsRequest**, using the knowledge that there is a one-to-one reply. **MergeChannelsConfirm** returns to the former top provider that generated **MergeChannelsRequest**. There the merged channels may be ignored, as they have remained in the information base pending a reply. Purged channel ids shall be deleted as they are for **PurgeChannelsIndication**.
+
+Intermediate MCS providers shall confirm that user ids proclaimed in private channel attributes are assigned to the subtree to which **MergeChannelsConfirm** is routed. If a private channel manager has been detached and reassigned elsewhere in the time since the antecedent **MergeChannelsRequest** was validated, an intermediate provider shall generate a **ChannelDisbandRequest** making the private channel a casualty of domain merger and shall move the channel id into the purged set. If any admitted users have been reassigned elsewhere, it shall exclude them from the channel.
+
+## 11.11 PurgeChannelsIndication
+
+**PurgeChannelsIndication** is generated at a former top provider following receipt of **MergeChannelsConfirm**. It is broadcast downward and purges the use of specified channel ids from subordinate providers.
+
+**Table 11-11/T.125 – PurgeChannelsIndication MCSPDU**
+
+| Contents          | Source     | Sink         |
+|-------------------|------------|--------------|
+| Detach User Ids   | Former top | Subordinates |
+| Purge channel Ids | Former top | Subordinates |
+
+Depending on the current use of a channel id, the effect of purging it is: MCS-DETACH-USER indication to all users if a user id channel; MCS-CHANNEL-LEAVE indication to the joined users if a static or assigned channel id; MCS-CHANNEL-DISBAND indication to the manager and MCS-CHANNEL-EXPEL indication to the admitted users if a private channel id.
+
+A former top provider, knowing the use of all channels in its lower domain, can generate the proper indications from channel ids alone. Its subordinates, however, may have only partial knowledge. They must be told which channel ids represent detached users, for which an indication is always generated, and which represent other kinds of channels, for which an indication is generated only if the channel is in use at the subordinate provider. Therefore, **PurgeChannelsIndication** divides the channel ids to be purged into these two categories.
+
+The purging of a user id through **PurgeChannelsIndication** shall have the same consequences as deletion through **DetachUserIndication**, except that, since the receiver of **PurgeChannelsIndication** is no longer top provider, it need not generate **ChannelDisbandIndication** or **TokenGiveConfirm** as a side effect.
+
+NOTE – A provider may receive in **PurgeChannelsIndication** static and assigned channel ids to which it is not joined or private channel ids for which its attachments are neither managers nor admitted users. Records of use maintained in the information base allow a provider to suppress primitive indications for such channel ids.
+
+## 11.12 MergeTokensRequest
+
+**MergeTokensRequest** is generated following the successful completion of MCS-CONNECT-PROVIDER. It communicates upward the attributes of tokens held by a former top provider so that they may be incorporated into the merged domain.
+
+**Table 11-12/T.125 – MergeTokensRequest MCSPDU**
+
+| Contents        | Source        | Sink         |
+|-----------------|---------------|--------------|
+| Merge Tokens    | Former top    | Top provider |
+| Purge Token Ids | Intermediates | Top provider |
+
+**MergeTokensRequest** may be filled with the attributes of multiple tokens, up to the domain limit on MCSPDU size. As detailed in the ASN.1 definitions of clause 7, each state of a token in use (grabbed, inhibited, giving, ungiveable, given) has its relevant set of attributes. These are held in the information base of the top MCS provider and are partially replicated into the subtrees where a token is used. When two domains are merged, through the action of MCS-CONNECT-PROVIDER, tokens that are in use in the lower domain must either be incorporated into the information base of the upper domain or be purged from the lower domain. This decision rests with the top provider of the merged domain.
+
+Each token shall be considered individually. If the domain limits on tokens in use allow it and the token id has not already been put to some conflicting use, the upper domain shall expand to include it. The inhibiting of a token id in the lower domain is not a conflict if it is also inhibited in the upper domain. All other combinations of simultaneous use are disallowed, requiring the token id to be purged from the lower domain.
+
+If a token has a large set of inhibiting users, its attributes may not fit into a single **MergeTokensRequest** and shall be sent upward in multiple MCSPDUs. However, the second and succeeding requests for the same inhibited token shall be delayed until a **MergeTokensConfirm** has been received in reply to the first. Only then is it known if domain limits have allowed the token to be put into use in the upper domain. If the first request fails, it shall not be repeated with a remaining subset of inhibitors.
+
+Each **MergeTokensRequest** elicits a **MergeTokensConfirm** reply from the top MCS provider, in the same sequence. A **MergeTokensConfirm** contains nothing that explicitly identifies the
+
+preceding **MergeTokensRequest**. Replies shall be routed solely by the order in which these MCSPDUs are received. MCS providers above the former top shall make a record of each unanswered **MergeTokensRequest** and whence it arrived, so that the corresponding **MergeTokensConfirm** may be returned via the same MCS connection.
+
+Intermediate MCS providers shall validate the user ids proclaimed in token attributes, to ensure that they are legitimately assigned to the subtree where the **MergeTokensRequest** originates. Invalid user ids shall be deleted. A token being given shall remain grabbed if either the grabber or the recipient, but not both, is deleted. If a token becomes released through this deletion of user ids, all of its attributes shall be deleted from the merge request and the token id alone shall be included in the set to be purged. An inhibited token shall remain inhibited in **MergeTokensRequest** even if all inhibitors are deleted, leaving an empty set in the attributes, because inhibitors may survive from other MCSPDUs. Except for this validation of user ids, intermediate MCS providers shall not modify the contents of an **MergeTokensRequest**.
+
+A former top provider shall await individual confirmation that all user ids have been incorporated into a merged domain or purged before it begins to submit token attributes for merger.
+
+## 11.13 MergeTokensConfirm
+
+**MergeTokensConfirm** replies to a preceding **MergeTokensRequest**. It reflects the same set of token ids and a subset of the attributes. Token attributes not incorporated into the merged domain are reported as token ids to be purged.
+
+**Table 11-13/T.125 – MergeTokensConfirm MCSPDU**
+
+| Contents        | Source       | Sink          |
+|-----------------|--------------|---------------|
+| Merge Tokens    | Top provider | Intermediates |
+| Purge Token Ids | Top provider | Former top    |
+
+Accepted token ids are reflected with the attributes that have been entered into the information base at the top MCS provider. Intermediate providers shall update their information base to conform.
+
+Tokens to be purged from the lower domain are listed by id only. If the same token ids are used in the upper domain, they are left undisturbed. Intermediate providers shall forward purged token ids without acting on them.
+
+MCS providers shall route **MergeTokensConfirm** to the source of the antecedent **MergeTokensRequest**, using the knowledge that there is a one-to-one reply. **MergeTokensConfirm** returns to the former top provider that generated **MergeTokensRequest**. There the merged tokens may be ignored, as they have remained in the information base pending a reply. Purged token ids shall be deleted as they are for **PurgeTokensIndication**.
+
+Intermediate MCS providers shall confirm that the user ids proclaimed in token attributes are assigned to the subtree to which **MergeTokensConfirm** is routed. If any user ids have been detached and reassigned elsewhere in the time since the antecedent **MergeTokensRequest** was validated, an intermediate provider shall generate for them a **DetachUserRequest** with reason code *channel purged*, making them casualties of domain merger. If a non-inhibited token id becomes released through this deletion of user ids, it shall be moved into the purged set.
+
+## 11.14 PurgeTokensIndication
+
+**PurgeTokensIndication** is generated at a former top provider following receipt of **MergeTokensConfirm**. It is broadcast downward and purges the use of specified token ids from subordinate providers.
+
+**Table 11-14/T.125 – PurgeTokensIndication MCSPDU**
+
+| Contents        | Source     | Sink         |
+|-----------------|------------|--------------|
+| Purge Token Ids | Former top | Subordinates |
+
+The effect of purging a token is severe: MCS-DETACH-USER indication to any user who has grabbed, inhibited, or is being given one of the token ids. A provider shall implement this by generating **DetachUserRequest** on behalf of the affected users with reason *token purged*.
+
+NOTE – It is anticipated that Recommendation T.122 may be revised in the future to allow MCS-TOKEN-RELEASE indication in this situation. This would allow the affected user to remain attached even though its right to use the token is withdrawn.
+
+## 11.15 DisconnectProviderUltimatum
+
+**DisconnectProviderUltimatum** is generated by an MCS-DISCONNECT-PROVIDER request. In turn, it generates an MCS-DISCONNECT-PROVIDER indication at the other end of an MCS connection. **DisconnectProviderUltimatum** compels the receiver to disconnect the MCS connection that conveyed it.
+
+**DisconnectProviderUltimatum** may also be generated by an MCS provider when it detects an error condition like the existence of a cycle in the domain hierarchy. In such cases, the reason is other than *user-requested*.
+
+**Table 11-15/T.125 – DisconnectProviderUltimatum MCSPDU**
+
+| Contents | Source              | Sink       |
+|----------|---------------------|------------|
+| Reason   | Requesting provider | Indication |
+
+## 11.16 RejectMCSPDUUltimatum
+
+**RejectMCSPDUUltimatum** is generated when an MCS provider receives an invalid MCSPDU or detects an MCS protocol error. It invites the peer provider at the other end of an MCS connection to disconnect, since recovery is uncertain from a situation that should not occur.
+
+**RejectMCSPDUUltimatum** diagnoses the error and returns an initial portion of the offending TSDU, typically as many octets as will fit in the maximum size MCSPDU. The receiving provider has the option to disconnect or to persevere.
+
+**Table 11-16/T.125 – RejectMCSPDUUltimatum MCSPDU**
+
+| Contents       | Source             | Sink              |
+|----------------|--------------------|-------------------|
+| Diagnostic     | Rejecting provider | Rejected provider |
+| Initial Octets | Rejecting provider | Rejected provider |
+
+## 11.17 AttachUserRequest
+
+**AttachUserRequest** is generated by an MCS-ATTACH-USER request. It rises to the top MCS provider, which returns an **AttachUserConfirm** reply. If the domain limit on number of user ids allows, a new user id is generated.
+
+**Table 11-17/T.125 – AttachUserRequest MCSPDU**
+
+| Contents | Source | Sink |
+|----------|--------|------|
+| (None)   | –      | –    |
+
+**AttachUserRequest** contains no information other than its MCSPDU type. The domain to which the user attaches is determined by the MCS connection conveying the MCSPDU. The only initial characteristic of the user id generated is its uniqueness.
+
+An MCS provider shall make a record of each unanswered **AttachUserRequest** received and by which MCS connection it arrived, so that a replying **AttachUserConfirm** can be routed back to the same source. To distribute replies fairly, each provider should maintain a first-in, first-out queue for this purpose.
+
+## 11.18 AttachUserConfirm
+
+**AttachUserConfirm** is generated at the top MCS provider upon receipt of **AttachUserRequest**. Routed back to the requesting provider, it generates an MCS-ATTACH-USER confirm.
+
+**Table 11-18/T.125 – AttachUserConfirm MCSPDU**
+
+| Contents             | Source       | Sink    |
+|----------------------|--------------|---------|
+| Result               | Top provider | Confirm |
+| Initiator (optional) | Top provider | Confirm |
+
+**AttachUserConfirm** contains a user id if and only if the result is successful. Providers that receive a successful **AttachUserConfirm** shall enter the user id into their information base.
+
+MCS providers shall route **AttachUserConfirm** to the source of an antecedent **AttachUserRequest**, using the knowledge that there is a one-to-one reply. A provider that transmits **AttachUserConfirm** shall note to which downward MCS connection the new user id is thereby assigned, so that it may validate the user id when it arises later in other requests.
+
+## 11.19 DetachUserRequest
+
+**DetachUserRequest** is generated by an MCS-DETACH-USER request. If valid, it rises to the top MCS provider, which deletes the user from its information base and broadcasts **DetachUserIndication** to advise other providers of the change.
+
+**Table 11-19/T.125 – DetachUserRequest MCSPDU**
+
+| Contents | Source              | Sink         |
+|----------|---------------------|--------------|
+| Reason   | Requesting provider | Top provider |
+| User Ids | Requesting provider | Top provider |
+
+An MCS-DETACH-USER request generates a **DetachUserRequest** containing reason *user-requested* and a single user id.
+
+**DetachUserRequest** shall also be generated by an MCS provider when a downward MCS connection is disconnected. At that point, all users in the affected subtree are lost and shall be reported as detached with reason *domain disconnected*. If user id assignments are pending, a later reply, either **MergeChannelsConfirm** or **AttachUserConfirm**, may then be left with no route back to its source in the disconnected subtree. A provider confronted with this shall also generate **DetachUserRequest** to delete the unassignable user ids.
+
+Providers that receive **DetachUserRequest** shall validate the user ids it contains to ensure that they are legitimately assigned to the subtree of origin. Invalid user ids shall be deleted. If no user ids remain, a **DetachUserRequest** shall be ignored.
+
+The user ids contained in **DetachUserRequest** shall not be deleted from the information base until a provider receives **DetachUserIndication**. This maintains consistency with the top MCS provider.
+
+NOTE – If more than one data priority is implemented in an MCS domain, **DetachUserIndication** may arrive at a given provider before data sent earlier but at a low priority by the same user. This protocol does not prevent data being delivered to an attachment even after it was reported through **DetachUserIndication** that the sender had detached.
+
+## 11.20 DetachUserIndication
+
+**DetachUserIndication** is generated at the top MCS provider upon receipt of **DetachUserRequest**. It is broadcast downward to all other providers and generates MCS-DETACH-USER indications at all attachments.
+
+At a surviving attachment, **DetachUserIndication** generates one MCS-DETACH-USER indication for each user id it contains. It does not matter whether the notified user was previously aware of the existence of a detached user.
+
+Upon receipt of a **DetachUserIndication** containing its own user id, an MCS attachment ceases to exist. Any static or assigned channels that become unjoined as a result of a user detaching shall be left via **ChannelLeaveRequest**.
+
+**Table 11-20/T.125 – DetachUserIndication MCSPDU**
+
+| Contents | Source       | Sink       |
+|----------|--------------|------------|
+| Reason   | Top provider | Indication |
+| User Ids | Top provider | Indication |
+
+Providers that receive **DetachUserIndication** shall delete the specified user ids from their information base, including as the manager or as admitted user of a private channel.
+
+Private channels managed by a detached user shall be deleted if there are no other admitted users. If other users remain, deletion of the manager shall cause the top provider to multicast a
+
+**ChannelDisbandIndication** towards them. If the set of users admitted to a private channel becomes empty and the manager does not reside in the subtree, the channel id shall be deleted from the information base. Otherwise, if a private channel becomes unjoined as a result of users detaching, a provider shall generate a corresponding **ChannelLeaveRequest**.
+
+A provider broadcasting **DetachUserIndication** shall compute, for each affected private channel and for each destination subtree, whether the subtree afterwards contains any attachments admitted to the private channel. If none, a provider shall conclude that the corresponding subordinate provider is no longer joined to the private channel and shall update its information base to this effect immediately, without waiting for **ChannelLeaveRequest**.
+
+Any tokens grabbed, being given to, or inhibited by a detached user shall have their state adjusted accordingly. The deletion of an intended token recipient shall cause the top provider to generate an unsuccessful **TokenGiveConfirm** towards the donor, unless it has released the token or itself detached.
+
+## 11.21 ChannelJoinRequest
+
+**ChannelJoinRequest** is generated by an MCS-CHANNEL-JOIN request. If valid, it rises until it reaches an MCS provider with enough information to generate a **ChannelJoinConfirm** reply. This may be the top MCS provider.
+
+**Table 11-21/T.125 – ChannelJoinRequest MCSPDU**
+
+| Contents   | Source              | Sink            |
+|------------|---------------------|-----------------|
+| Initiator  | Requesting Provider | Higher provider |
+| Channel Id | Request             | Higher provider |
+
+The user id of the initiating MCS attachment is supplied by the MCS provider that receives the primitive request. Providers that receive **ChannelJoinRequest** subsequently shall validate the user id to ensure that it is legitimately assigned to the subtree of origin. If the user id is invalid, the MCSPDU shall be ignored.
+
+NOTE – This allows for the possibility that **ChannelJoinRequest** may be racing upward against a purge of the initiating user id flowing down. A provider that receives **PurgeChannelsIndication** first might receive a **ChannelJoinRequest** soon thereafter that contains an invalid user id. This is a normal occurrence and is not cause for rejecting the MCSPDU.
+
+**ChannelJoinRequest** may rise to an MCS provider that has the requested channel id in its information base. Any such provider, being consistent with the top MCS provider, will agree whether the request should succeed. If the request should fail, the provider shall generate an unsuccessful **ChannelJoinConfirm**. If it should succeed and the provider is already joined to the same channel, the provider shall generate a successful **ChannelJoinConfirm**. In these two cases, MCS-CHANNEL-JOIN completes without necessarily visiting the top MCS provider. Otherwise, if the request should succeed but the channel is not yet joined, a provider shall forward **ChannelJoinRequest** upward.
+
+If **ChannelJoinRequest** rises to the top MCS provider, the channel id requested may be zero, which is in no information base because it is an invalid id. If the domain limit on the number of channels in use allows, a new assigned channel id shall be generated and returned in a successful **ChannelJoinConfirm**. If the channel id requested is in the static range and the domain limit on the number of channels in use allows, the channel id shall be entered into the information base and shall likewise be returned in a successful **ChannelJoinConfirm**.
+
+Otherwise, the request will succeed only if the channel id is already in the information base of the top MCS provider. A user id channel can only be joined by the same user. A private channel id can be joined only by users previously admitted by its manager. An assigned channel id can be joined by any user.
+
+## 11.22 ChannelJoinConfirm
+
+**ChannelJoinConfirm** is generated at a higher MCS provider upon receipt of **ChannelJoinRequest**. Routed back to the requesting provider, it generates an MCS-CHANNEL-JOIN confirm.
+
+**Table 11-22/T.125 – ChannelJoinConfirm MCSPDU**
+
+| Contents              | Source          | Sink           |
+|-----------------------|-----------------|----------------|
+| Result                | Higher provider | Confirm        |
+| Initiator             | Higher provider | MCSPDU routing |
+| Requested             | Higher provider | Confirm        |
+| Channel Id (optional) | Higher provider | Confirm        |
+
+**ChannelJoinConfirm** contains a joined channel id if and only if the result is successful.
+
+The channel id requested is the same as in **ChannelJoinRequest**. This helps the initiating attachment relate MCS-CHANNEL-JOIN confirm to an antecedent request. Since **ChannelJoinRequest** need not rise to the top provider, confirms may occur out of order.
+
+If the result is successful, **ChannelJoinConfirm** joins the receiving MCS provider to the specified channel. Thereafter, higher providers shall route to it any data that users send over the channel. A provider shall remain joined to a channel as long as any of its attachments or subordinate providers does. To leave the channel, a provider shall generate **ChannelLeaveRequest**.
+
+Providers that receive a successful **ChannelJoinConfirm** shall enter the channel id into their information base. If not already there, the channel id shall be given type static or assigned, depending on its range.
+
+**ChannelJoinConfirm** shall be forwarded in the direction of the initiating user id. If the user id is unreachable because an MCS connection no longer exists, the provider shall decide whether it has reason to remain joined to the channel. If not, it shall generate **ChannelLeaveRequest**.
+
+## 11.23 ChannelLeaveRequest
+
+**ChannelLeaveRequest** is generated by an MCS provider to remove itself from a set of channels. The motivation may be an MCS-CHANNEL-LEAVE request from the last attachment joined to a channel. **ChannelLeaveRequest** continues to rise if higher providers, as a consequence, also lose their reason for being joined.
+
+Providers that receive **ChannelLeaveRequest** shall stop routing to the MCS connection that conveyed it any data that users send over the specified channels. When the last attachment or subordinate provider leaves a channel, an MCS provider shall generate a corresponding **ChannelLeaveRequest**.
+
+**Table 11-23/T.125 – ChannelLeaveRequest MCSPDU**
+
+| Contents    | Source              | Sink            |
+|-------------|---------------------|-----------------|
+| Channel Ids | Requesting provider | Higher provider |
+
+## 11.24 ChannelConveneRequest
+
+**ChannelConveneRequest** is generated by an MCS-CHANNEL-CONVENE request. If valid, it rises to the top MCS provider, which returns a **ChannelConveneConfirm** reply. If the domain limit on number of channel ids allows, a new private channel id is generated.
+
+**ChannelConveneRequest** contains the initiating user id, which shall be validated as explained for **ChannelJoinRequest**.
+
+The requester becomes manager of the private channel. Initially the channel is unjoined and its manager is the only admitted user.
+
+**Table 11-24/T.125 – ChannelConveneRequest MCSPDU**
+
+| Contents  | Source              | Sink            |
+|-----------|---------------------|-----------------|
+| Initiator | Requesting provider | Higher provider |
+
+## 11.25 ChannelConveneConfirm
+
+**ChannelConveneConfirm** is generated at the top MCS provider upon receipt of **ChannelConveneRequest**. Routed back to the requesting provider, it generates an MCS-CHANNEL-CONVENE confirm.
+
+**TABLE 11-25/T.125 – ChannelConveneConfirm MCSPDU**
+
+| Contents              | Source       | Sink           |
+|-----------------------|--------------|----------------|
+| Result                | Top provider | Confirm        |
+| Initiator             | Top provider | MCSPDU routing |
+| Channel Id (optional) | Top provider | Confirm        |
+
+**ChannelConveneConfirm** contains a private channel id if and only if the result is successful.
+
+Providers that receive a successful **ChannelConveneConfirm** shall enter the channel id into their information base as a private channel with the initiating user id as its manager.
+
+**ChannelConveneConfirm** shall be forwarded in the direction of the initiating user id. If the user id is unreachable because an MCS connection no longer exists, no special actions need be taken, as a **DetachUserIndication** must arrive later to report that the initiator has detached. Since the initiator is its manager, this will delete the channel id from the information base.
+
+## 11.26 ChannelDisbandRequest
+
+**ChannelDisbandRequest** is generated by an MCS-CHANNEL-DISBAND request. If valid, it rises to the top MCS provider, which deletes the private channel id and generates **ChannelDisbandIndication**.
+
+**Table 11-26/T.125 – ChannelDisbandRequest MCSPDU**
+
+| Contents   | Source              | Sink         |
+|------------|---------------------|--------------|
+| Initiator  | Requesting provider | Top provider |
+| Channel Id | Request             | Top provider |
+
+**ChannelDisbandRequest** may also be generated by an MCS provider on its own initiative to disband a channel.
+
+**ChannelDisbandRequest** contains the initiating user id, which shall be validated to ensure that it is legitimately assigned to the subtree of origin. If the initiator does not equal the manager of the private channel, as recorded in the information base, the MCSPDU shall be ignored.
+
+## 11.27 ChannelDisbandIndication
+
+**ChannelDisbandIndication** is generated at the top MCS provider upon receipt of **ChannelDisbandRequest**. It is multicast downward to providers that contain the manager or an admitted user in their subtree. It generates MCS-CHANNEL-EXPEL indications to admitted users with reason *channel disbanded*.
+
+**Table 11-27/T.125 – ChannelDisbandIndication MCSPDU**
+
+| Contents   | Source       | Sink       |
+|------------|--------------|------------|
+| Channel Id | Top provider | Indication |
+
+**ChannelDisbandIndication** shall also be generated by the top MCS provider when the manager of a private channel is detached.
+
+Providers that receive **ChannelDisbandIndication** shall delete the channel from their information base.
+
+## 11.28 ChannelAdmitRequest
+
+**ChannelAdmitRequest** is generated by an MCS-CHANNEL-ADMIT request. If valid, it rises to the top MCS provider, which admits the specified users to the private channel and multicasts **ChannelAdmitIndication** to advise providers in whose subtree they reside.
+
+**ChannelAdmitRequest** contains the initiating user id, which shall be validated as explained for **ChannelDisbandRequest**.
+
+The other user ids of **ChannelAdmitRequest**, representing users to be admitted, shall be validated at the top MCS provider, which alone knows the entire user population. Those that are invalid shall be omitted from the resulting **ChannelAdmitIndication**.
+
+**Table 11-28/T.125 – ChannelAdmitRequest MCSPDU**
+
+| Contents   | Source              | Sink         |
+|------------|---------------------|--------------|
+| Initiator  | Requesting provider | Top provider |
+| Channel Id | Request             | Top provider |
+| User Ids   | Request             | Top provider |
+
+The user ids contained in **ChannelAdmitRequest** shall not be admitted to the private channel until a provider receives **ChannelAdmitIndication**. This maintains consistency with the top MCS provider.
+
+## 11.29 ChannelAdmitIndication
+
+**ChannelAdmitIndication** is generated at the top MCS provider upon receipt of **ChannelAdmitRequest**. It is multicast downward to providers that contain a newly-admitted user in their subtree. It generates MCS-CHANNEL-ADMIT indications at the affected attachments.
+
+Providers that receive **ChannelAdmitIndication** shall ordinarily update the channel in their information base, admitting the specified users that reside in their subtree. However, if a provider is the former top of a lower domain that is being merged as a result of MCS-CONNECT-PROVIDER, it may refuse the admission by generating **DetachUserRequest** for the affected user ids with reason *channel purged*.
+
+**Table 11-29/T.125 – ChannelAdmitIndication MCSPDU**
+
+| Contents   | Source       | Sink           |
+|------------|--------------|----------------|
+| Initiator  | Top provider | Indication     |
+| Channel Id | Top provider | Indication     |
+| User Ids   | Top provider | MCSPDU routing |
+
+## 11.30 ChannelExpelRequest
+
+**ChannelExpelRequest** is generated by an MCS-CHANNEL-EXPEL request. If valid, it rises to the top MCS provider, which expels the specified users from the private channel and multicasts **ChannelExpelIndication** to advise providers in whose subtree they reside.
+
+**ChannelExpelRequest** contains the initiating user id, which shall be validated as explained for **ChannelDisbandRequest**.
+
+The other user ids of **ChannelExpelRequest**, representing users to be expelled, shall be validated at the top MCS provider, which alone knows the entire set of admitted users. Those that were not admitted shall be omitted from the resulting **ChannelExpelIndication**.
+
+The user ids contained in **ChannelExpelRequest** shall not be expelled from the private channel until a provider receives **ChannelExpelIndication**. This maintains consistency with the top MCS provider.
+
+**Table 11-30/T.125 – ChannelExpelRequest MCSPDU**
+
+| Contents   | Source              | Sink         |
+|------------|---------------------|--------------|
+| Initiator  | Requesting provider | Top provider |
+| Channel Id | Request             | Top provider |
+| User Ids   | Request             | Top provider |
+
+## 11.31 ChannelExpelIndication
+
+**ChannelExpelIndication** is generated at the top MCS provider upon receipt of **ChannelExpelRequest**. It is multicast downward to providers that contain an expelled user in their
+
+subtree. It generates MCS-CHANNEL-EXPEL indications at the affected attachments with reason *user-requested*.
+
+**Table 11-31/T.125 – ChannelExpelIndication MCSPDU**
+
+| Contents   | Source       | Sink           |
+|------------|--------------|----------------|
+| Channel Id | Top provider | Indication     |
+| User Ids   | Top provider | MCSPDU routing |
+
+Providers that receive **ChannelExpelIndication** shall update the channel in their information base, deleting the specified users from the set of users admitted to the channel. If the set of users admitted to a private channel becomes empty and the manager does not reside in the subtree, the channel id shall be deleted from the information base. Otherwise, if the channel becomes unjoined as a result of expulsions, a provider shall generate a corresponding **ChannelLeaveRequest**.
+
+A provider forwarding **ChannelExpelIndication** shall compute, for each destination subtree, whether it afterwards contains any attachments admitted to the private channel. If none, a provider shall conclude that the corresponding subordinate provider is no longer joined to the private channel and shall update its information base to this effect immediately, without waiting for **ChannelLeaveRequest**.
+
+## 11.32 SendDataRequest
+
+**SendDataRequest** is generated by an MCS-SEND-DATA request. If valid, it rises toward the top MCS provider. Along the way, providers may generate from it an **SendDataIndication** with identical contents and multicast this downward.
+
+**SendDataRequest** contains the initiating user id, which shall be validated as explained for **ChannelJoinRequest**.
+
+If the channel id is listed in the information base of the receiving MCS provider as a private channel and the initiator of **SendDataRequest** is not an admitted user, the MCSPDU shall be ignored.
+
+**SendDataRequest** contains the reliability level that was specified by the original MCS-SEND-DATA request. If the data is unreliable, the domain reference ID is also specified.
+
+The initial or additional TC that conveys **SendDataRequest** shall match its data priority, taking into account the number of priorities implemented in the domain. MCSPDUs arriving over an MCS connection by the wrong TC shall be rejected.
+
+**Table 11-32/T.125 – SendDataRequest MCSPDU**
+
+| Contents            | Source              | Sink            |
+|---------------------|---------------------|-----------------|
+| Initiator           | Requesting provider | Higher provider |
+| Channel Id          | Request             | Higher provider |
+| Reliability         | Request             | Higher provider |
+| Domain Reference ID | Request             | Higher provider |
+| Data Priority       | Request             | Higher provider |
+| Segmentation        | Requesting provider | Higher provider |
+| Total Data Size     | Requesting provider | Higher provider |
+| User Data           | Request             | Higher provider |
+
+The segmentation flags *begin* and *end* shall be set by a provider to show the relationship of user data in the **SendDataRequest** to the boundaries of an MCS service data unit. Providers have freedom to fragment and reassemble MCSPDUs that are part of the same MCS service data unit, so long as this does not disturb the integrity of user data. However, there should be little advantage in such manipulation, as the maximum size of an MCSPDU is constant throughout a domain.
+
+For a given **SendDataRequest**, if the *begin* segmentation flag is true, and the *end* flag is false, the Total Data Size of the segmented user data will be provided. This field will only be present if both the source and sink nodes are members of the V3 Summit.
+
+A provider shall generate from **SendDataRequest** an **SendDataIndication** with the same content and shall transmit it to all providers that are joined to the specified channel, excepting the subordinate provider that transmitted **SendDataRequest** upward. Unless the channel is listed in the provider's information base as a user id residing in its subtree, it shall also forward **SendDataRequest** upward.
+
+## 11.33 SendDataIndication
+
+**SendDataIndication** is generated at a higher MCS provider upon receipt of **SendDataRequest**. It is multicast downward and generates MCS-SEND-DATA indications at all attachments that are joined to the channel.
+
+**Table 11-33/T.125 – SendDataIndication MCSPDU**
+
+| Contents            | Source          | Sink                |
+|---------------------|-----------------|---------------------|
+| Initiator           | Higher provider | Indication          |
+| Channel Id          | Higher provider | Indication          |
+| Reliability         | Higher provider | Indication          |
+| Domain Reference ID | Higher provider | Indication          |
+| Data Priority       | Higher provider | Indication          |
+| Segmentation        | Higher provider | Indicating provider |
+| Total Data Size     | Higher provider | Indicating provider |
+| User Data           | Higher provider | Indication          |
+
+The initial or additional TC that conveys **SendDataIndication** shall match its data priority, taking into account the number of priorities implemented in a domain. MCSPDUs arriving over an MCS connection by the wrong TC shall be rejected.
+
+The segmentation flags *begin* and *end* permit user data to be reassembled into a complete MCS service data unit. These flags shall be interpreted in the context of **SendDataIndication** MCSPDUs arriving from the same user over the same channel and at the same priority. A stream of fragments to be reassembled may be interleaved with other MCSPDUs and data from other users over other channels at other priorities.
+
+For a given **SendDataIndication**, if the *begin* segmentation flag is true, and the *end* flag is false, the Total Data Size of the segmented user data will be provided. This field will only be present if both the source and sink nodes are members of the V3 Summit.
+
+It is a matter of local implementation how service data units are indicated to attached MCS users. One possibility is to deliver each MCSPDU as a separate interface data unit, with segmentation flags included. Alternative approaches that may seek to reassemble within the receiving provider should
+
+make some provision for large service data units and should reflect to the user the relative order in which service data units begin to arrive.
+
+Providers that receive **SendDataIndication** shall forward it to all subordinates that are joined to the channel.
+
+## 11.34 UniformSendDataRequest
+
+**UniformSendDataRequest** is generated by an MCS-UNIFORM-SEND-DATA request. If valid, it rises to the top MCS provider, which generates from it a **UniformSendDataIndication** with identical contents and multicasts this downward.
+
+**Table 11-34/T.125 – UniformSendDataRequest MCSPDU**
+
+| Contents            | Source              | Sink         |
+|---------------------|---------------------|--------------|
+| Initiator           | Requesting provider | Top provider |
+| Channel Id          | Request             | Top provider |
+| Reliability         | Request             | Top provider |
+| Domain Reference ID | Request             | Top provider |
+| Data Priority       | Request             | Top provider |
+| Segmentation        | Requesting provider | Top provider |
+| Total Data Size     | Requesting provider | Top provider |
+| User Data           | Request             | Top provider |
+
+**UniformSendDataRequest** contains the initiating user id, which shall be validated as explained for **ChannelJoinRequest**.
+
+If the channel id is listed in the information base of the receiving MCS provider as a private channel and the initiator of **UniformSendDataRequest** is not an admitted user, the MCSPDU shall be ignored.
+
+The initial or additional TC that conveys **UniformSendDataRequest** shall match its data priority, taking into account the number of priorities implemented in the domain. MCSPDUs arriving over an MCS connection by the wrong TC shall be rejected.
+
+The segmentation flags *begin* and *end* shall be set by a provider to show the relationship of user data in the **UniformSendDataRequest** to the boundaries of an MCS service data unit. Providers have freedom to fragment and reassemble MCSPDUs that are part of the same MCS service data unit, so long as this does not disturb the integrity of user data. However, there should be little advantage in such manipulation, as the maximum size of an MCSPDU is constant throughout a domain.
+
+For a given **UniformSendDataRequest**, if the *begin* segmentation flag is true, and the *end* flag is false, the Total Data Size of the segmented user data will be provided. This field will only be present if both the source and sink nodes are members of the V3 Summit.
+
+The top MCS provider shall generate from **UniformSendDataRequest** a **UniformSendDataIndication** with the same content.
+
+## 11.35 UniformSendDataIndication
+
+**UniformSendDataIndication** is generated at the top MCS provider upon receipt of **UniformSendDataRequest**. It is multicast downward and generates MCS-UNIFORM-SEND-DATA indications at all attachments that are joined to the channel.
+
+**Table 11-35/T.125 – UniformSendDataIndication MCSPDU**
+
+| Contents            | Source       | Sink                |
+|---------------------|--------------|---------------------|
+| Initiator           | Top provider | Indication          |
+| Channel Id          | Top provider | Indication          |
+| Reliability         | Top provider | Indication          |
+| Domain Reference ID | Top provider | Indication          |
+| Data Priority       | Top provider | Indication          |
+| Segmentation        | Top provider | Indicating provider |
+| Total Data Size     | Top provider | Indicating provider |
+| User Data           | Top provider | Indication          |
+
+The initial or additional TC that conveys **UniformSendDataIndication** shall match its data priority, taking into account the number of priorities implemented in the domain. MCSPDUs arriving over an MCS connection by the wrong TC shall be rejected.
+
+The segmentation flags *begin* and *end* permit user data to be reassembled into a complete MCS service data unit. These flags shall be interpreted in the context of **UniformSendDataIndication** MCSPDUs arriving from the same user over the same channel and at the same priority. A stream of fragments to be reassembled may be interleaved with other MCSPDUs and data from other users over other channels at other priorities.
+
+For a given **UniformSendDataIndication**, if the *begin* segmentation flag is true, and the *end* flag is false, the Total Data Size of the segmented user data will be provided. This field will only be present if both the source and sink nodes are members of the V3 Summit.
+
+It is a matter of local implementation how service data units are indicated to attached MCS users.
+
+Providers that receive **UniformSendDataIndication** shall forward it to all subordinates that are joined to the channel.
+
+## 11.36 TokenGrabRequest
+
+**TokenGrabRequest** is generated by an MCS-TOKEN-GRAB request. If valid, it rises to the top MCS provider, which returns a **TokenGrabConfirm** reply.
+
+**Table 11-36/T.125 – TokenGrabRequest MCSPDU**
+
+| Contents  | Source              | Sink         |
+|-----------|---------------------|--------------|
+| Initiator | Requesting provider | Top provider |
+| Token Id  | Request             | Top provider |
+
+**TokenGrabRequest** contains the initiating user id, which shall be validated as explained for **ChannelJoinRequest**.
+
+If the token is free and the domain limit on the number of tokens in use allows, it shall become grabbed. If the token is inhibited by the requesting user only, it shall become grabbed. Otherwise, the state of the token shall not change.
+
+## 11.37 TokenGrabConfirm
+
+**TokenGrabConfirm** is generated at the top MCS provider upon receipt of **TokenGrabRequest**. Routed back to the requesting provider, it generates an MCS-TOKEN-GRAB confirm.
+
+**Table 11-37/T.125 – TokenGrabConfirm MCSPDU**
+
+| Contents     | Source       | Sink                   |
+|--------------|--------------|------------------------|
+| Result       | Top provider | Confirm                |
+| Initiator    | Top provider | MCSPDU routing         |
+| Token Id     | Top provider | Confirm                |
+| Token Status | Top provider | Intermediate Providers |
+
+The result shall be *successful* if the token was previously free or if the token was converted from inhibited to grabbed by the same user. Other results are *too many tokens* and *token not available*. The latter applies to a token already grabbed by the requester; this may be discerned by examining the token status.
+
+Providers that receive **TokenGrabConfirm** shall update the token state in their information base to agree with the status returned.
+
+**TokenGrabConfirm** shall be forwarded in the direction of the initiating user id. If the user id is unreachable because an MCS connection no longer exists, no special actions need be taken, as a **DetachUserIndication** must arrive later to report that the initiator has detached. This will release its hold on the token id in the information base.
+
+## 11.38 TokenInhibitRequest
+
+**TokenInhibitRequest** is generated by an MCS-TOKEN-INHIBIT request. If valid, it rises to the top MCS provider, which returns a **TokenInhibitConfirm** reply.
+
+**Table 11-38/T.125 – TokenInhibitRequest MCSPDU**
+
+| Contents  | Source              | Sink         |
+|-----------|---------------------|--------------|
+| Initiator | Requesting provider | Top provider |
+| Token Id  | Request             | Top provider |
+
+**TokenInhibitRequest** contains the initiating user id, which shall be validated as explained for **ChannelJoinRequest**.
+
+If the token is free and the domain limit on the number of tokens in use allows, it shall become inhibited. If the token is grabbed by the requesting user, it shall become inhibited. If the token is
+
+already inhibited, the requester shall be added to the set of inhibitors. Otherwise, the state of the token shall not change.
+
+## 11.39 TokenInhibitConfirm
+
+**TokenInhibitConfirm** is generated at the top MCS provider upon receipt of **TokenInhibitRequest**. Routed back to the requesting provider, it generates an MCS-TOKEN-INHIBIT confirm.
+
+The result shall be *successful* if the token was previously free or inhibited or if the token was converted from grabbed to inhibited by the same user. Other results are *too many tokens* and *token not available*.
+
+**Table 11-39/T.125 – TokenInhibitConfirm MCSPDU**
+
+| Contents     | Source       | Sink                   |
+|--------------|--------------|------------------------|
+| Result       | Top provider | Confirm                |
+| Initiator    | Top provider | MCSPDU routing         |
+| Token Id     | Top provider | Confirm                |
+| Token Status | Top provider | Intermediate Providers |
+
+Providers that receive **TokenInhibitConfirm** shall update the token state in their information base to agree with the status returned.
+
+This MCSPDU is routed in the same way as **TokenGrabConfirm**.
+
+## 11.40 TokenGiveRequest
+
+**TokenGiveRequest** is generated by an MCS-TOKEN-GIVE request. If valid, it rises to the top MCS provider, which generates either **TokenGiveIndication** or an unsuccessful **TokenGiveConfirm**.
+
+**Table 11-40/T.125 – TokenGiveRequest MCSPDU**
+
+| Contents  | Source              | Sink         |
+|-----------|---------------------|--------------|
+| Initiator | Requesting provider | Top provider |
+| Token Id  | Request             | Top provider |
+| Recipient | Request             | Top provider |
+
+**TokenGiveRequest** contains the initiating user id, which shall be validated as explained for **ChannelJoinRequest**.
+
+If the token is grabbed by the requester and the intended recipient exists, **TokenGiveIndication** shall be transmitted toward the recipient. Otherwise, the request shall fail, the state of the token shall be unchanged, and **TokenGiveConfirm** shall be transmitted toward the requester with the result *token not possessed* or *no such user*.
+
+## 11.41 TokenGiveIndication
+
+**TokenGiveIndication** is generated at the top MCS provider upon receipt of **TokenGiveRequest**. Routed to the intended recipient, it generates an MCS-TOKEN-GIVE indication.
+
+Providers that receive **TokenGiveIndication** shall ordinarily update the token id in their information base to the state of being given from initiator to recipient. However, if a provider is the former top of a lower domain that is being merged as a result of MCS-CONNECT-PROVIDER, it may refuse the offered token by generating **TokenGiveResponse** with reason *domain merging*.
+
+**Table 11-41/T.125 – TokenGiveIndication MCSPDU**
+
+| Contents  | Source       | Sink           |
+|-----------|--------------|----------------|
+| Initiator | Top provider | Indication     |
+| Token Id  | Top provider | Indication     |
+| Recipient | Top provider | MCSPDU routing |
+
+**TokenGiveIndication** shall be forwarded in the direction of the recipient user id. If the user id is unreachable because an MCS connection no longer exists, no special actions need be taken, as a **DetachUserIndication** must arrive later to report that the recipient has detached. This will release its hold on the token id in the information base.
+
+## 11.42 TokenGiveResponse
+
+**TokenGiveResponse** is generated by an MCS-TOKEN-GIVE response. If valid, it rises to the top MCS provider, which generates **TokenGiveConfirm** to inform the token's donor of the outcome.
+
+**Table 11-42/T.125 – TokenGiveResponse MCSPDU**
+
+| Contents  | Source              | Sink         |
+|-----------|---------------------|--------------|
+| Result    | Response            | Top provider |
+| Recipient | Responding provider | Top provider |
+| Token Id  | Responding provider | Top provider |
+
+A *successful* result shall signify the recipient's acceptance of the offered token.
+
+The user id of the responding MCS attachment is supplied by the MCS provider that receives the primitive response. Providers that receive **TokenGiveResponse** subsequently shall validate the user id to ensure that it is legitimately assigned to the subtree of origin. If the user id is invalid, the MCSPDU shall be ignored.
+
+If the token id is not listed in the provider's information base as being given to the recipient, the MCSPDU shall be ignored. If the token id is still grabbed by the donor, its state shall be updated to grabbed by the recipient if the result is successful; otherwise it shall revert to grabbed by the donor or shall be deleted from the information base, depending on whether the donor resides in the subtree of the provider. If the token id has since been released by the donor and the result is not successful, the token shall be deleted from the provider's information base.
+
+If the MCSPDU is not invalid and ignored, it shall be forwarded upward. The top MCS provider shall act on **TokenGiveResponse** as specified above. In addition, if the donor has not already released the token, the top provider shall generate **TokenGiveConfirm** containing the same result as **TokenGiveResponse**.
+
+## 11.43 TokenGiveConfirm
+
+**TokenGiveConfirm** is generated at the top MCS provider upon receipt of **TokenGiveResponse**. Routed back to the requesting provider, it generates a MCS-TOKEN-GIVE confirm.
+
+**Table 11-43/T.125 – TokenGiveConfirm MCSPDU**
+
+| Contents     | Source       | Sink                   |
+|--------------|--------------|------------------------|
+| Result       | Top provider | Confirm                |
+| Initiator    | Top provider | MCSPDU routing         |
+| Token Id     | Top provider | Confirm                |
+| Token Status | Top provider | Intermediate Providers |
+
+**TokenGiveConfirm** shall also be generated by the top MCS provider upon receipt of **TokenGiveRequest** if a token cannot be offered to the intended recipient. This takes the place of generating **TokenGiveIndication**. **TokenGiveConfirm** shall also be generated with result *no such user* if the recipient is detached before **TokenGiveResponse** is received.
+
+Providers that receive **TokenGiveConfirm** shall update the token state in their information base to agree with the status returned.
+
+This MCSPDU is routed in the same way as **TokenGrabConfirm**.
+
+## 11.44 TokenPleaseRequest
+
+**TokenPleaseRequest** is generated by an MCS-TOKEN-PLEASE request. If valid, it rises to the top MCS provider, which multicasts **TokenPleaseIndication** to alert current users of the token.
+
+**TokenPleaseRequest** contains the initiating user id, which shall be validated as explained for **ChannelJoinRequest**.
+
+**Table 11-44/T.125 – TokenPleaseRequest MCSPDU**
+
+| Contents  | Source              | Sink         |
+|-----------|---------------------|--------------|
+| Initiator | Requesting provider | Top provider |
+| Token Id  | Request             | Top provider |
+
+## 11.45 TokenPleaseIndication
+
+**TokenPleaseIndication** is generated at the top MCS provider upon receipt of **TokenPleaseRequest**. It is multicast downward and generates MCS-TOKEN-PLEASE indications.
+
+Providers that receive **TokenPleaseIndication** shall forward it to all subordinates that contain in their subtree a user who has grabbed, inhibited, or is being given the specified token.
+
+**Table 11-45/T.125 – TokenPleaseIndication MCSPDU**
+
+| Contents  | Source       | Sink       |
+|-----------|--------------|------------|
+| Initiator | Top provider | Indication |
+| Token Id  | Top provider | Indication |
+
+## 11.46 TokenReleaseRequest
+
+**TokenReleaseRequest** is generated by an MCS-TOKEN-RELEASE request. If valid, it rises to the top MCS provider, which returns a **TokenReleaseConfirm** reply.
+
+**Table 11-46/T.125 – TokenReleaseRequest MCSPDU**
+
+| Contents  | Source              | Sink         |
+|-----------|---------------------|--------------|
+| Initiator | Requesting provider | Top provider |
+| Token Id  | Request             | Top provider |
+
+**TokenReleaseRequest** contains the initiating user id, which shall be validated as explained for **ChannelJoinRequest**.
+
+If the token is grabbed by the requester, it shall become free. If it is inhibited, the requester shall be removed from the set of inhibitors; if this set becomes empty, the token shall become free. If the token is in the process of being given away by the requester, it shall enter a distinct intermediate state of given to the intended recipient, pending receipt of **TokenGiveResponse**. Otherwise the state of the token shall not change.
+
+## 11.47 TokenReleaseConfirm
+
+**TokenReleaseConfirm** is generated at the top MCS provider upon receipt of **TokenReleaseRequest**. Routed back to the requesting provider, it generates an MCS-TOKEN-RELEASE confirm.
+
+**Table 11-47/T.125 – TokenReleaseConfirm MCSPDU**
+
+| Contents     | Source       | Sink                   |
+|--------------|--------------|------------------------|
+| Result       | Top provider | Confirm                |
+| Initiator    | Top provider | MCSPDU routing         |
+| Token Id     | Top provider | Confirm                |
+| Token Status | Top provider | Intermediate Providers |
+
+The result shall be *successful* if the token was grabbed or inhibited by the requester or if the requester was in the process of giving it away. The other possible result is *token not possessed*.
+
+Providers that receive **TokenReleaseConfirm** shall update the token state in their information base to agree with the status returned.
+
+This MCSPDU is routed in the same way as **TokenGrabConfirm**.
+
+## 11.48 TokenTestRequest
+
+**TokenTestRequest** is generated by an MCS-TOKEN-TEST request. If valid, it rises to the top MCS provider, which returns a **TokenTestConfirm** reply.
+
+**TokenTestRequest** contains the initiating user id, which shall be validated as explained for **ChannelJoinRequest**.
+
+**Table 11-48/T.125 – TokenTestRequest MCSPDU**
+
+| Contents  | Source              | Sink         |
+|-----------|---------------------|--------------|
+| Initiator | Requesting provider | Top provider |
+| Token Id  | Request             | Top provider |
+
+## 11.49 TokenTestConfirm
+
+**TokenTestConfirm** is generated at the top MCS provider upon receipt of **TokenTestRequest**. Routed back to the requesting provider, it generates an MCS-TOKEN-TEST confirm.
+
+Providers that receive **TokenTestConfirm** should find that the token state in their information base agrees with the status returned.
+
+This MCSPDU is routed in the same way as **TokenGrabConfirm**.
+
+**Table 11-49/T.125 – TokenTestConfirm MCSPDU**
+
+| Contents     | Source       | Sink    |
+|--------------|--------------|---------|
+| Initiator    | Top provider | MCSPDU  |
+| Token Id     | Top provider | Confirm |
+| Token Status | Top provider | Confirm |
+
+## 11.50 CapabilitiesNotificationRequest
+
+**CapabilitiesNotificationRequest** is an upward flowing PDU which is used to alert higher nodes in the hierarchy of desired changes to the summit capabilities list, or to alert the summit of a change in the status of V2 node connections. It is also sometimes sent by intermediate nodes which detect the loss of a downward connection. Any node which detects the establishment or loss of a connection with a V2 node might send this PDU.
+
+**Table 11-50/T.125 – CapabilitiesNotificationRequest MCSPDU**
+
+| Contents        | Source              | Sink            |
+|-----------------|---------------------|-----------------|
+| V2 Node Present | Requesting provider | Higher provider |
+| Add List        | Requesting provider | Higher provider |
+| Remove List     | Requesting provider | Higher provider |
+
+The contents of the **CapabilitiesNotificationRequest** are as follows:
+
+*V2 Node Present:* This is a flag which will be set if a V2 node connects to the V3 summit. At such time as the V2 node disconnects, this flag will be reset.
+
+*Add List:* This is a list of request capabilities (described in 11.50.1) which a given node requests to be added to the summit capabilities list. This field is optional because not every **CapabilitiesNotificationRequest** generated will be for the purpose of adding capabilities to the list.
+
+*Remove List:* This is a list of request capabilities which a given node requests to be removed from the summit capabilities list. This field is optional because not every **CapabilitiesNotificationRequest** generated will be for the purpose of removing capabilities from the list.
+
+### 11.50.1 Request Capability
+
+The following table summarizes the contents of the Request Capability. The AddList and RemoveList in a **CapabilitiesNotificationRequest** PDU is comprised of Request Capabilities.
+
+|                         |
+|-------------------------|
+| Capability ID           |
+| Capability Class        |
+| Participation Indicator |
+
+*Capability ID:* This is an identification assigned to the capability. The ID may be standard (i.e. documented in T.125) or non-standard.
+
+*Capability Class:* This indicates whether the capability has an associated value, and the processing associated with that value. All capabilities are of class MIN, MAX, or NULL.
+
+*Participation Indicator:* This field indicates the degree of participation required of other V3 nodes in the summit. The possible values of this field are "partial" or "global".
+
+## 11.51 CapabilitiesNotificationIndication
+
+**CapabilitiesNotificationIndication** is a downward flowing PDU which is used to alert nodes to a change in the summit capabilities, or to a change in the status of V2 node connections. This PDU is sent by the summit provider or any intermediate node which has a need to inform a lower node of a change.
+
+**Table 11-51/T.125 – CapabilitiesNotificationIndication MCSPDU**
+
+| Contents        | Source          | Sink        |
+|-----------------|-----------------|-------------|
+| V2 Node Present | Higher provider | Subordinate |
+| Add List        | Higher provider | Subordinate |
+| Remove List     | Higher provider | Subordinate |
+
+The contents of the **CapabilitiesNotificationIndication** are as follows:
+
+*V2 Node Present:* This is a flag which will be set if a V2 node is connected to the V3 summit. At such time as all V2 nodes disconnect, this flag will be reset.
+
+*Add List:* This is a list of indication capabilities (described in 11.51.1) which a given node has decided need to be added to the summit capabilities list. This field is optional because not every **CapabilitiesNotificationIndication** generated will be for the purpose of adding capabilities to the list.
+
+*Remove List:* This is a list of indication capabilities which a given node has decided need to be removed from the summit capabilities list. This field is optional because not every **CapabilitiesNotificationIndication** generated will be for the purpose of removing capabilities from the list.
+
+### 11.51.1 Indication Capability
+
+The following table summarizes the contents of the Indication Capability. The AddList and RemoveList in a **CapabilitiesNotificationIndication** PDU is comprised of Indication Capabilities.
+
+|                             |
+|-----------------------------|
+| Capability ID               |
+| Capability Class            |
+| Summit Provider Supported   |
+| Intermediate Node Supported |
+
+*Capability ID:* This is an identification assigned to the capability. The ID may be standard (i.e. documented in T.125) or non-standard.
+
+*Capability Class:* This indicates whether the capability has an associated value, and the processing associated with that value. All capabilities are of class MIN, MAX, or NULL.
+
+*Summit Provider Supported:* This is a flag which indicates whether the V3 summit provider supports this capability.
+
+*Intermediate Node Supported:* This is a flag which indicates whether the intervening nodes on the path to the summit provider support this capability. If there are no intervening nodes, meaning a node has a direct connection to the summit provider, then this flag is set.
+
+# 12 MCS provider information base
+
+## 12.1 Hierarchical replication
+
+Although an MCS provider may host multiple domains, it serves each one independently. It maintains logically separate information bases for each to record the state of channel and token resources in use. The description that follows is set in the context of a single domain.
+
+The MCS resources that need to be managed in a domain are channel ids and token ids. User ids are a subset of channel ids. Domain parameters limit how many ids of each category can be in use simultaneously. This allows a provider to compute how much memory is needed for the information base in the worst case of a fully-utilized domain.
+
+In the hierarchy of a domain, the ids in use at any given MCS provider stabilize to a subset of those in use at its immediate superior. Information about an id is recorded where it can be used to support MCS services involving that id. Recording information more widely would entail extra costs in MCSPDU traffic to keep the information up to date. Since the information recorded at a provider is consistent with that recorded at superior providers, within the limit of MCSPDU propagation delay, it may be said that the provider information base is partially replicated through the domain hierarchy.
+
+Domain parameters become fixed and unchangeable with the establishment of the first MCS connection of a domain. A provider that lacks capacity for the maximum number of ids specified in each category may negotiate to join a domain on false pretense. It may speculate that at its low position in a hierarchy it will not be called upon to retain more than a fraction of the total information base. Such a provider may not support attachments and subordinates with the full range of MCS services they expect. Nonetheless, until its capacity is actually exceeded, such a provider may appear to be an equal member of the domain. This strategy may appeal to terminal nodes with limited aspirations.
+
+Ids are placed into use first at the top MCS provider. They are placed into use at subordinate providers by a selective downward flow of MCSPDUs. Most are deleted from use in the same top-down manner. There are necessarily intervals during which a subordinate provider records as in use an id that its superiors do not, because the MCSPDU that deletes the id remains in transit. This is not, however, a situation that endures. Control MCSPDUs are received and processed in the order of their
+
+transmission. The consequences of processing an MCSPDU, including its creation or deletion of channel and token ids, take effect before attention shifts to the next input event.
+
+An exception to the preceding paragraph is the deletion of static and assigned channel ids. Although placed into use by a downward flow of **ChannelJoinConfirm**, these channel ids are deleted in the opposite order – from the bottom up. Specifically, they are deleted when an accumulation of MCS-CHANNEL-LEAVE requests from attachments and **ChannelLeaveRequest** MCSPDUs from subordinate providers combine to leave a channel unjoined. Such transitions motivate the transmission of **ChannelLeaveRequest** further upward. Thus, for these two cases, the channel ids recorded as in use are a strict subset of those in use at the superior provider. This is an accidental corollary of optimizations designed to speed channel management as a prelude to data transfer.
+
+Channels ids are put into use by **MergeChannelsConfirm**, **AttachUserConfirm**, **ChannelJoinConfirm**, **ChannelConveneConfirm**, and **ChannelAdmitIndication**; they are deleted by **MergeChannelsConfirm**, **PurgeChannelsIndication**, **DetachUserIndication**, **ChannelLeaveRequest**, **ChannelDisbandIndication**, and **ChannelExpelIndication**. Token ids are put into use by **MergeTokensConfirm**, **TokenGrabConfirm**, **TokenInhibitConfirm**, and **TokenGiveIndication**; they are deleted by **MergeTokensConfirm**, **PurgeTokensIndication**, **TokenReleaseConfirm**, **TokenGiveResponse** and **TokenGiveConfirm**. When an id is put into use at a given provider, the MCSPDU that is the cause may be forwarded to zero, one, several, or all subordinate providers. The use of an id may grow or contract gradually as, for example, individual users are admitted to and expelled from a private channel. When an id is deleted from a given provider, the MCSPDU that effects this is forwarded to all subordinates who may still be recording the id as in use.
+
+The use of an id is ultimately tied to actions on a channel or token by a user attached to the domain (although there may be some delay, as explained, in communicating changes through the transmission of MCSPDUs). The ids recorded stably as in use at a given MCS provider are those that are actively employed by some user in the subtree of the provider. It follows that they are a subset of those recorded stably at any superior provider.
+
+Deleting a user id has the corollary effect of deleting channel ids and token ids of which it is the sole user in a subtree.
+
+Criteria for considering channel ids and token ids to be in use are specified in the following subclauses.
+
+## 12.2 Channel information
+
+The four kinds of channel have corresponding criteria to determine whether a given attachment is considered to be using the channel id, hence whether it is to be represented in a provider's information base:
+
+- a) A static channel id (range 1..1000) is in use if the user has joined the channel with a successful MCS-CHANNEL-JOIN confirm and not left by MCS-CHANNEL-LEAVE request or indication.
+- b) A user id channel is in use if it was assigned to the user by a successful MCS-ATTACH-USER confirm and the user has not detached by MCS-DETACH-USER request or indication.
+- c) A private channel id is in use if the user has created the channel with a successful MCS-CHANNEL-CONVENE confirm or been admitted to it with MCS-CHANNEL-ADMIT indication and not expelled by MCS-CHANNEL-EXPEL indication and the channel has not been disbanded by MCS-CHANNEL-DISBAND request or indication.
+
+- d) An assigned channel id is in use if the user has joined the channel with a successful MCS-CHANNEL-JOIN confirm and not left by MCS-CHANNEL-LEAVE request or indication.
+
+This information shall be recorded for a channel id in use:
+
+- a) The kind of channel it represents (static, user id, private, or assigned).
+- b) By which MCS attachments and which MCS connections to subordinate providers the channel is joined.
+- c) If a user id channel, the direction to it, that is, either the local MCS attachment to which the user id is assigned or the downward MCS connection to a subordinate provider in whose subtree the user resides.
+- d) If a private channel id, the user id of the manager who convened it (whether or not the manager itself is in the subtree of the provider) and the set of all user ids in the subtree of the provider who have been admitted to the channel.
+
+The information recorded for channel ids is employed as explained in clause 10 to validate request MCSPDUs and to route indication and confirm MCSPDUs.
+
+## 12.3 Token information
+
+The state transitions of a token id are shown in Figure 12-1. The following abbreviations apply:
+
+DUin – DetachUserIndication
+
+TGcf – TokenGrabConfirm
+
+TIcf – TokenInhibitConfirm
+
+TRcf – TokenReleaseConfirm
+
+TVin – TokenGiveIndication
+
+TVrs – TokenGiveResponse
+
+TVcf – TokenGiveConfirm
+
+An individual token id can be *grabbed* by a single user or *inhibited* by one or more. The action of **TokenGiveIndication** converts the state to *giving* along the branch of a domain hierarchy leading from the top MCS provider toward the intended recipient. This state decays to *ungiveable* if the recipient detaches before its provider responds with **TokenGiveResponse**. It resolves to *given* if instead the donor releases the token explicitly or detaches. During the giving of a token, the branch of a domain hierarchy leading from the donor intersects the branch leading toward the recipient at least at the top MCS provider. The token state changes from *grabbed* to *giving*, and possibly thereafter to *ungiveable* or *given*, only along this intersection.
+
+![State transition diagram for a token id showing states: Not in Use, Ungivable, Given, Inhibited, Grabbed, and Giving. Transitions are labeled with actions like TRcf, DUin, TVcf, DUin, TVin, TVrs, TGcf, and TIcf.](0adfaa8c2562a9fe3a8a96165d7d59a3_img.jpg)
+
+```
+
+graph TD
+    NotInUse((Not in Use))
+    Ungivable((Ungivable))
+    Given((Given))
+    Inhibited((Inhibited))
+    Grabbed((Grabbed))
+    Giving((Giving))
+
+    NotInUse -- "TRcf  
+DUin" --> Ungivable
+    Ungivable -- "TVcf" --> NotInUse
+    Ungivable -- "DUin" --> Giving
+    Ungivable -- "TVrs  
+DUin" --> Given
+    Given -- "TRcf  
+DUin" --> Ungivable
+    Given -- "TVrs" --> Inhibited
+    Inhibited -- "TGcf" --> Grabbed
+    Grabbed -- "TIcf" --> Inhibited
+    Grabbed -- "TVin" --> Giving
+    Giving -- "TVrs" --> Grabbed
+    Giving -- "TVcf" --> NotInUse
+    Giving -- "TVrs  
+DUin" --> Given
+    Given -- "TVrs" --> NotInUse
+    
+```
+
+T1602450-97
+
+State transition diagram for a token id showing states: Not in Use, Ungivable, Given, Inhibited, Grabbed, and Giving. Transitions are labeled with actions like TRcf, DUin, TVcf, DUin, TVin, TVrs, TGcf, and TIcf.
+
+**Figure 12-1/T.125 – State transitions of a token id**
+
+The user of a token stands in relationship to it as grabber, inhibitor, recipient, or both grabber and recipient (when giving a token to itself):
+
+- a) The user is a grabber if it has seized a token with a successful MCS-TOKEN-GRAB confirm and not released it by MCS-TOKEN-RELEASE request or successful MCS-TOKEN-GIVE confirm nor converted it with a successful MCS-TOKEN-INHIBIT confirm or if it has accepted an offered token with a successful MCS-TOKEN-GIVE response.
+- b) The user is an inhibitor if it has seized a token with a successful MCS-TOKEN-INHIBIT confirm and not released it with MCS-TOKEN-RELEASE request nor converted it with a successful MCS-TOKEN-GRAB confirm.
+- c) The user is a recipient if it has been offered a token by MCS-TOKEN-GIVE indication and not released it with an unsuccessful MCS-TOKEN-GIVE response.
+
+This information shall be recorded for a token id in use:
+
+- a) The state of the token id at the MCS provider (not necessarily identical to that at the top provider).
+- b) If grabbed or ungivable, the user id of the grabber in the subtree of the provider.
+- c) If giving, the user id of the grabber (whether or not the grabber is in the subtree of the provider).
+- d) If giving or given, the user id of the recipient in the subtree of the provider.
+- e) If inhibited, the set of all user ids in the subtree of the provider who have inhibited the token.
+
+The information recorded for token ids in use is employed as explained in clause 10 to validate response MCSPDUs and to route indication MCSPDUs.
+
+The state of a token id at a subordinate provider need not be identical to that at the top MCS provider. This is due to the fact that a token donor does not in general process **TokenGiveIndication** or **TokenGiveResponse** and that a recipient does not in general process a donor's **TokenReleaseConfirm**. Figure 12-2 shows states that may arise in a complex token interaction.
+
+![A state transition diagram for a token across providers A through H. The diagram shows a hierarchy of states: 'Grabbed: A' (A) and 'Grabbed: B' (B) lead to 'Grabbed: B' (E), which leads to 'Giving: A→B' (F). 'Giving: A→B' (F) leads to 'Ungiveable: A' (G), which leads to 'Ungiveable: A' (H). 'Ungiveable: A' (G) also leads to 'Not in use' (C) and 'Not in use' (D). Arrows indicate transitions: 'PurgeChannelIndication (purge B)' from G to F, and 'TokenGiveResponse (B accepts)' from E to F.](5e05915b2a93a3b404422e0966a7c924_img.jpg)
+
+```
+
+graph TD
+    A([Grabbed: A  
+A]) --> E([Grabbed: B  
+E])
+    B([Grabbed: B  
+B]) --> E
+    E --> F([Giving: A→B  
+F])
+    F -- "PurgeChannelIndication  
+(purge B)" --> G([Ungiveable: A  
+G])
+    F -- "TokenGiveResponse  
+(B accepts)" --> E
+    G --> H([Ungiveable: A  
+TokenGiveConfirm  
+(Selfgrabbed A)  
+H])
+    G --> C([Not in use  
+C])
+    G --> D([Not in use  
+D])
+  
+```
+
+T1602460-97
+
+A state transition diagram for a token across providers A through H. The diagram shows a hierarchy of states: 'Grabbed: A' (A) and 'Grabbed: B' (B) lead to 'Grabbed: B' (E), which leads to 'Giving: A→B' (F). 'Giving: A→B' (F) leads to 'Ungiveable: A' (G), which leads to 'Ungiveable: A' (H). 'Ungiveable: A' (G) also leads to 'Not in use' (C) and 'Not in use' (D). Arrows indicate transitions: 'PurgeChannelIndication (purge B)' from G to F, and 'TokenGiveResponse (B accepts)' from E to F.
+
+**Figure 12-2/T.125 – States of a token that may arise in a complex interaction**
+
+The figure focuses on one token id in the information base of providers A through H. A plausible history is that the token was given by user A, attached to provider A, to user B, attached to provider B. Before user B could respond, however, provider G connected the domain to a new top provider H and began a merger. The new domain, unable to accept user B because of a conflict in channel ids, initiated its purge through **PurgeChannelsIndication**. This MCSPDU is shown having completed part of its journey through providers G and D. Provider G, as a result, has adjusted its token state from *giving* to *ungiveable* and merged the token, with this state, into the new domain. The new top provider H, presented with a token in such a state, has queued for transmission an unsuccessful **TokenGiveConfirm** to return the token to user A. At the time shown, the token has also finally been accepted by user B, and a **TokenGiveResponse** is making its way up the recipient's branch of the domain hierarchy, changing the token state at each provider from *giving* to *grabbed* by B. Two MCSPDUs now converge on provider F, and whichever arrives first determines its subsequent state there: either returned to *grabbed* by A or transiently *grabbed* by B and then *not in use* again after user B is detached. In either case, the state of the token will stabilize to *grabbed* by A when the new top provider transmits the **TokenGiveConfirm** it has pending.
+
+# 13 Elements of procedure
+
+## 13.1 MCSPDU sequencing
+
+Control MCSPDUs remain in sequence between any pair of MCS providers because they travel over a single TC, the initial TC of an MCS connection. MCS providers shall process received MCSPDUs and shall transmit any resulting output MCSPDUs in the same order. This applies to MCSPDUs that are simply forwarded up or down the domain hierarchy as well as to MCSPDUs that are transformed, such as requests or responses into indications or confirms. The sequencing of MCSPDUs shall be maintained within an MCS provider if it is necessary to queue outputs for later transmission due to the back-pressure of flow control along a TC.
+
+Data MCSPDUs of different priorities need not remain in sequence. On the contrary, the benefit of relative priorities is only achieved when higher priority data is advanced ahead of lower priority data. This means that it should be transmitted over separate TCs and queued separately within each MCS provider. If the number of data priorities implemented in a domain is less than the maximum, fewer TCs are available, but providers that elect to do so may still maintain separate queues internally. This realizes some but not all the benefits of relative priority.
+
+An MCS provider shall maintain the sequence of data MCSPDUs transmitted at a given priority. This is a tighter restriction than that imposed by Recommendation T.122, which guarantees only the sequencing of service data units transmitted at a given priority over the same destination channel.
+
+Control MCSPDUs and data MCSPDUs of top priority are transmitted over the same initial TC and shall receive equal attention by an MCS provider. Data of lower priorities may lag behind. Control indications advancing ahead may arrive before lower priority data that was actually transmitted first.
+
+## **13.2 Input flow control**
+
+An MCS provider has goals that sometimes conflict: to keep data moving briskly through a domain despite transient blockages towards some receivers, to give transmitters fair access to the available bandwidth, and to prevent any party from lagging far behind peers who are receiving the same multicast data. MCS is a reliable service that preserves the integrity of user data. Since a provider has limited capacity to store MCSPDUs when they cannot be transmitted immediately, it must have a defense of sometimes refusing further inputs. While details of the interface to transport services are a local matter, the abstract effect must be that incoming TSDUs are held in TC pipelines, intact and in sequence, to be received at some future time when flow control is lifted. As TC pipelines fill, remote MCS providers may find that they are blocked by back-pressure from transmitting further MCSPDUs and may need to invoke a similar defense.
+
+Flow control is not signalled explicitly in the MCS protocol. This is a function of lower layers that would be wasteful to duplicate. As a result, it is difficult to sense, through the medium of an intervening TC, whether a remote provider is resisting further inputs. To meet conflicting goals as well as possible, the policies described next may be recommended.
+
+An MCS provider may grant each incoming TC a fixed quota of buffers that it may fill with MCSPDUs before back pressure is applied. Each buffer is processed as specified in this protocol, then assigned for output to zero or more outgoing TCs. Output may occur immediately or may be delayed because a transport pipeline is full. Until it is output to the last TC, a buffer is charged against the input quota of the TC by which it arrived. After it is output to all requisite TCs, it is recycled as an increment to that quota. When a quota is exhausted, further inputs over the corresponding TC are halted. Input quotas may be set taking into account whether a TC is part of an upward or downward MCS connection and what data priority it represents.
+
+Buffering can mitigate a disparity of rates between transmitters and receivers. A quota on inputs can prevent any one TC from monopolizing resources. It can also bound how far out of step two receivers of the same multicast data can get. The recommended scheme is not clever enough, however, to anticipate all patterns of use and may sometimes slow the rate of data transfer through a domain when there are acceptable alternatives. The invention of better flow control policies (implemented locally and requiring no additional communication of MCSPDUs) may be a means of product differentiation.
+
+## **13.3 Throughput enforcement**
+
+In contrast to input flow control, some support for throughput enforcement is explicit in the MCS protocol. Firstly, the rate that is enforced is a domain parameter negotiated through
+
+MCS-CONNECT-PROVIDER. Secondly, the time interval over which throughput is monitored before taking adverse action is communicated by each MCS provider to its superior through **ErectDomainRequest**. To describe the throughput enforcement interval requires that providers share some common principles of behavior. Still, enforcement remains a heuristic technique with room for invention.
+
+Enforcing a minimum input rate at each receiver is an option available to controller applications, which establish the MCS connections of a domain. This option is selected through the domain parameter for enforced throughput, which is stated in octets per second. While it seems intuitive that a party should not be allowed to run arbitrarily slowly and thereby obstruct data transfer among others, there is danger in seeking to enforce throughput too strictly.
+
+Complex patterns of multiple transmitters are a problem. The kinds of back-pressure to which an enforcement policy reacts may not result from a single abnormally slow receiver. In the first place, MCSPDUs heading downward must compete for attention with MCSPDUs that rise from below but are reflected back, notably **SendDataIndication**. The downward flow experienced through a peer provider may therefore attain only a fraction of the nominal bandwidth and may vary dynamically with the number of other connections and attachments to the peer. Secondly, only top priority MCSPDUs can be expected to flow continuously over an MCS connection. Lesser priorities can properly be blocked by a peer provider for long periods of time due to the intensity of traffic received from other sources at higher priorities. Finally, there can be great variation in instantaneous throughput if it is measured by how long a blocked MCSPDU must wait before being accepted onto an MCS connection. Among other things, this can depend on how many and in what order MCSPDUs from other sources are queued inside the peer provider.
+
+Nonetheless, throughput enforcement is a valuable option in practical situations where patterns of data transfer are known to be more uniform. It shall be interpreted as requiring a minimal output of MCSPDUs to each direct MCS attachment and to each MCS connection downward over a time interval to be specified by the enforcing MCS provider. Each MCSPDU output, both control and data, shall count towards throughput as though it were the maximum size allowed by domain parameters. The output of an MCSPDU to an MCS attachment shall mean delivery of the associated primitive indication or confirm. Output to a downward MCS connection shall mean the absence of back-pressure at the transport service interface and acceptance into the corresponding TC pipeline.
+
+Output shall be monitored as long as one or more MCSPDUs are queued, regardless of data priority, towards a given attachment or downward connection. Whenever the queues empty, monitoring shall cease, with no enforcement action taken. At the same time, no credit for good behavior shall be recorded to offset future slowdowns. Monitoring shall resume as soon as back-pressure prevents any MCSPDU from being output and requires it to be queued instead. While one or more MCSPDUs remain queued, the number actually output shall be counted over a set interval of time.
+
+A throughput enforcement interval shall be chosen by each MCS provider. The interval shall be long enough to allow at least one MCSPDU of maximum size to be output at the minimum throughput. An MCS provider shall advise its superior of the interval chosen and of any subsequent changes to it by transmitting **ErectDomainRequest** upward. A provider shall act against the offending MCS attachment or downward MCS connection at the end of any interval during which the monitored throughput fails to meet expectations. It shall detach the user or disconnect the connection.
+
+Superior providers may set their throughput enforcement interval to be longer than that of any subordinate plus some margin of reaction time. The aim is to encourage enforcement action first at the lowest provider in a position to detect a problem. When a violator is removed at the end of some lower interval, superior providers should have enough time to sense the restoration of throughput to adequate levels. If they act too quickly, they may penalize a larger subtree than necessary and disrupt innocents in the domain.
+
+The controller applications that set domain parameters should be conservative in their demands, expecting that throughput may occasionally dip during periods of intense application stimuli. If their concern is simply to defend against receivers that stop accepting anything at all, they may set the minimum throughput very low. Knowing the maximum MCSPDU size and enforced throughput rate, controllers can calculate the minimum interval that must elapse before any blockage is detected and overcome.
+
+## 13.4 Domain configuration
+
+Recommendation T.122 provides no mechanism for configuring the set of domains supported by an MCS provider. This must be considered a local matter whose standardization may be the subject of further study. This protocol assumes that an MCS provider will recognize some domain selectors as valid and others as invalid. It provides for domain selectors to be communicated as part of establishing an MCS connection.
+
+An MCS provider participates implicitly in the negotiation of domain parameters. Whether the calling or the called side, it constrains the range of allowed parameter values according to limits for which it is configured. An MCS provider shall freeze the negotiability of domain parameters once any user has attached to a domain or once the first MCS connection has been established.
+
+## 13.5 Domain merger
+
+Domains are merged as a consequence of MCS-CONNECT-PROVIDER. If it is convenient to arrange that one domain or the other be empty at this point, there is little complication in a merger. In the most general case, however, provision must be made for updating the information base at the remaining top provider to contain the information base of the former top provider and for resolving any conflicts that become apparent. The details of this are explained in clause 10.
+
+To aid understanding, an example of domain merger is illustrated in the sequence of Figures 13-1 through 13-4. Here provider E represents a former top that has joined a new domain by the highlighted MCS connection to an intermediate provider F. It is irrelevant whether provider E or provider F initiated the MCS connection.
+
+![Diagram illustrating the domain merger step one - Establish hierarchy. The diagram shows a hierarchical structure of providers. At the top is the 'Top MCS Provider'. Below it are 'Provider A', 'Provider B', 'Provider C', and 'Provider D'. 'Provider E' is shown as a former top provider that has joined a new domain by connecting to 'Provider F'. The diagram shows the sequence of events: 1. PlumbDomainIndication from Provider A to Provider E. 2. PlumbDomainIndication from Provider B to Provider F. 3. ErectDomainRequest from Provider E to Provider F. 4. ErectDomainRequest from Provider F to the Top MCS Provider.](da90447206621f137780272a2bf807a4_img.jpg)
+
+```
+
+graph TD
+    TopMCSProvider([Top MCS Provider])
+    ProviderA([Provider A])
+    ProviderB([Provider B])
+    ProviderC([Provider C])
+    ProviderD([Provider D])
+    ProviderE([Provider E])
+    ProviderF([Provider F])
+
+    ProviderA -- "1 PlumbDomainIndication" --> ProviderE
+    ProviderB -- "2 PlumbDomainIndication" --> ProviderF
+    ProviderE -- "3 ErectDomainRequest" --> ProviderF
+    ProviderF -- "4 ErectDomainRequest" --> TopMCSProvider
+
+    TopMCSProvider --- ProviderC
+    TopMCSProvider --- ProviderD
+
+```
+
+T1602470-97
+
+Diagram illustrating the domain merger step one - Establish hierarchy. The diagram shows a hierarchical structure of providers. At the top is the 'Top MCS Provider'. Below it are 'Provider A', 'Provider B', 'Provider C', and 'Provider D'. 'Provider E' is shown as a former top provider that has joined a new domain by connecting to 'Provider F'. The diagram shows the sequence of events: 1. PlumbDomainIndication from Provider A to Provider E. 2. PlumbDomainIndication from Provider B to Provider F. 3. ErectDomainRequest from Provider E to Provider F. 4. ErectDomainRequest from Provider F to the Top MCS Provider.
+
+**Figure 13-1/T.125 – Domain merger step one – Establish hierarchy**
+
+Provider E, finding itself at the lower end of a connection upward, assumes responsibility for executing the merger. Since it is unsafe to transact other activity while the information base is in flux, provider E stops accepting inputs from its subtree. Any MCSPDUs already in transit from providers A and B or new ones generated before the merger is completed will be safeguarded and processed later. The downward flow of MCSPDUs, however, is not impeded, whether generated by provider E or forwarded from further above.
+
+Until the merger completes, the only confirm MCSPDUs provider E will receive are **MergeChannelsConfirm** and **MergeTokensConfirm**, since user requests are not allowed upward. These will confirm or purge channel and token ids already in use. Indication MCSPDUs **PurgeChannelsIndication**, **PurgeTokensIndication**, **DetachUserIndication**, and **ChannelDisbandIndication** of the upper domain may also arrive, deleting channel and token ids from the lower domain whose merger has been individually confirmed. Unconfirmed ids of the lower domain are protected against deletion, because as yet they mean something different from the same id of the upper domain. **PlumbDomainIndication** must be obeyed to enforce the domain height limit. Remaining indications need not be applied by provider E while merger is in progress. Data transfers, in particular, need not flow between the formerly separate domains until merger is completed; they cannot flow until at least the channels conveying them have been sorted out. Two indications that can place new ids into use may be inconvenient to apply. To keep the information base consistent, if provider E refuses **ChannelAdmitIndication** or **TokenGiveIndication**, it will react as specified in clause 10.
+
+The first actions of provider E are to send **PlumbDomainIndication** downward, to ensure that the latest MCS connection has not created a cycle that would invalidate the principle that each domain hierarchy have exactly one top provider, and to send **ErectDomainRequest** upward to report its existing height and throughput enforcement interval. Provider F, advancing thereby from height 2 to 3, passes **ErectDomainRequest** along to the top provider, which then attains height 4.
+
+In the second stage of domain merger, provider E sends upward as many instances of **MergeChannelsRequest** as it takes to contain the user ids in its information base. User ids that do not conflict with the upper domain are confirmed and the rest are purged in equally many instances of **MergeChannelsConfirm**. Provider E generates **PurgeChannelsIndication** from **MergeChannelsConfirm** to report any purges throughout its subtree. This stage ends when all user ids have either been explicitly confirmed or purged.
+
+![Diagram illustrating the domain merger step two - Merge user id channels. The diagram shows a hierarchical structure of providers. At the top is the 'Top MCS Provider'. Below it is 'Provider F'. Below 'Provider F' are 'Provider E', 'Provider C', and 'Provider D'. Below 'Provider E' are 'Provider A' and 'Provider B'. The diagram shows the flow of messages: 1. 'MergeChannelsRequest' from Provider E to Provider F. 2. 'MergeChannelsRequest' from Provider F to Top MCS Provider. 3. 'MergeChannelsConfirm' from Top MCS Provider to Provider F. 4. 'MergeChannelsConfirm' from Provider F to Provider E. 5. 'PurgeChannelsIndication' from Provider E to Provider A. 6. 'PurgeChannelsIndication' from Provider E to Provider B.](8f8caebe58364416a2eda21039d8c7bf_img.jpg)
+
+```
+
+graph TD
+    TopMCS[Top MCS Provider]
+    ProviderF[Provider F]
+    ProviderE[Provider E]
+    ProviderA[Provider A]
+    ProviderB[Provider B]
+    ProviderC[Provider C]
+    ProviderD[Provider D]
+
+    TopMCS --- ProviderF
+    ProviderF --- ProviderE
+    ProviderF --- ProviderC
+    ProviderF --- ProviderD
+    ProviderE --- ProviderA
+    ProviderE --- ProviderB
+
+    ProviderE -- "1 MergeChannelsRequest" --> ProviderF
+    ProviderF -- "2 MergeChannelsRequest" --> TopMCS
+    TopMCS -- "3 MergeChannelsConfirm" --> ProviderF
+    ProviderF -- "4 MergeChannelsConfirm" --> ProviderE
+    ProviderE -- "5 PurgeChannelsIndication" --> ProviderA
+    ProviderE -- "6 PurgeChannelsIndication" --> ProviderB
+
+```
+
+Diagram illustrating the domain merger step two - Merge user id channels. The diagram shows a hierarchical structure of providers. At the top is the 'Top MCS Provider'. Below it is 'Provider F'. Below 'Provider F' are 'Provider E', 'Provider C', and 'Provider D'. Below 'Provider E' are 'Provider A' and 'Provider B'. The diagram shows the flow of messages: 1. 'MergeChannelsRequest' from Provider E to Provider F. 2. 'MergeChannelsRequest' from Provider F to Top MCS Provider. 3. 'MergeChannelsConfirm' from Top MCS Provider to Provider F. 4. 'MergeChannelsConfirm' from Provider F to Provider E. 5. 'PurgeChannelsIndication' from Provider E to Provider A. 6. 'PurgeChannelsIndication' from Provider E to Provider B.
+
+T1602480-97
+
+**Figure 13-2/T.125 – Domain merger step two – Merge user id channels**
+
+Stage three resembles stage two, but concerns token ids rather than user id channels, using a parallel set of MCSPDUs. If user ids had not been merged first, portions of a later **MergeTokensRequest** could be refused as invalid and the affected token ids would be unnecessarily purged. In the case of an inhibited token, the entire set of inhibiting users may not fit into a single MCSPDU. Provider E waits for confirmation of the first subset it sends upward before sending the inhibited token again with the remaining user ids. This protects against the first set being refused due to too many token ids in use but the remainder later being accepted, which would corrupt the information base. This stage ends when all token ids have either been explicitly confirmed or purged.
+
+![Diagram illustrating Domain merger step three – Merge token ids. The diagram shows a hierarchical structure of providers. At the top is the 'Top MCS Provider'. Below it is 'Provider F'. Below 'Provider F' are 'Provider E', 'Provider C', and 'Provider D'. Below 'Provider E' are 'Provider A' and 'Provider B'. The diagram shows the flow of messages: 1. 'MergeTokensRequest' from Provider E to Provider F. 2. 'MergeTokensRequest' from Provider F to Top MCS Provider. 3. 'MergeTokensConfirm' from Top MCS Provider to Provider F. 4. 'MergeTokensConfirm' from Provider F to Provider E. 5. 'PurgeTokensIndication' from Provider E to Provider A. 6. 'PurgeTokensIndication' from Provider E to Provider B.](dae88eec6d1005984029b794ff8b7a9e_img.jpg)
+
+```
+
+graph TD
+    TopMCSProvider([Top MCS Provider])
+    ProviderF([Provider F])
+    ProviderE([Provider E])
+    ProviderA([Provider A])
+    ProviderB([Provider B])
+    ProviderC([Provider C])
+    ProviderD([Provider D])
+
+    TopMCSProvider --- ProviderF
+    ProviderF --- ProviderE
+    ProviderF --- ProviderC
+    ProviderF --- ProviderD
+    ProviderE --- ProviderA
+    ProviderE --- ProviderB
+
+    ProviderE -- "1 MergeTokensRequest" --> ProviderF
+    ProviderF -- "2 MergeTokensRequest" --> TopMCSProvider
+    TopMCSProvider -- "3 MergeTokensConfirm" --> ProviderF
+    ProviderF -- "4 MergeTokensConfirm" --> ProviderE
+    ProviderE -- "5 PurgeTokensIndication" --> ProviderA
+    ProviderE -- "6 PurgeTokensIndication" --> ProviderB
+  
+```
+
+T1602490-97
+
+Diagram illustrating Domain merger step three – Merge token ids. The diagram shows a hierarchical structure of providers. At the top is the 'Top MCS Provider'. Below it is 'Provider F'. Below 'Provider F' are 'Provider E', 'Provider C', and 'Provider D'. Below 'Provider E' are 'Provider A' and 'Provider B'. The diagram shows the flow of messages: 1. 'MergeTokensRequest' from Provider E to Provider F. 2. 'MergeTokensRequest' from Provider F to Top MCS Provider. 3. 'MergeTokensConfirm' from Top MCS Provider to Provider F. 4. 'MergeTokensConfirm' from Provider F to Provider E. 5. 'PurgeTokensIndication' from Provider E to Provider A. 6. 'PurgeTokensIndication' from Provider E to Provider B.
+
+**Figure 13-3/T.125 – Domain merger step three – Merge token ids**
+
+Stage four involves the same MCSPDUs as stage two, but they contain different channel ids. User id channels having been taken care of, what remains are static, private, and assigned channel ids. If user ids had not been merged first, portions of a later **MergeChannelsRequest** could be refused as invalid and the affected channel ids would be unnecessarily purged. In the case of a private channel, the entire set of users admitted by the channel manager may not fit into a single MCSPDU. Provider E waits for confirmation of the first subset it sends upward before sending the private channel again with the remaining user ids. This protects against the first set being refused due to too many channel ids in use but the remainder later being accepted, which would corrupt the information base. This stage ends and domain merger completes when all remaining channel ids have either been explicitly confirmed or purged.
+
+NOTE – Merging token ids first makes their exclusive possession more effective in suppressing data flow conflicts. Otherwise, data may leak between domains, as channel ids are confirmed, before the conflict is revealed through a token purge.
+
+## 13.6 Domain disconnection
+
+When an upward MCS connection is disconnected, an MCS provider shall eradicate its subtree of the domain by detaching all its direct MCS attachments and disconnecting all its other MCS connections. The affected provider cannot in general establish a residual domain in its own subtree, because it has no record of request MCSPDUs that were sent upward for which it will never receive a matching confirm MCSPDU.
+
+When a downward MCS connection is disconnected, an MCS provider shall generate **DetachUserRequest** MCSPDUs for all users residing in that portion of its subtree, giving as reason *domain disconnected*.
+
+![Diagram illustrating Domain merger step four – Merge remaining channel ids. The diagram shows a hierarchical tree structure of MCS providers. At the top is 'Top MCS Provider'. It has four children: 'Provider A', 'Provider B', 'Provider C', and 'Provider D'. 'Provider A' and 'Provider B' are merged into 'Provider E'. 'Provider E' and 'Provider F' are merged into 'Top MCS Provider'. The diagram shows the sequence of messages: 1 MergeChannelsRequest (Provider A to Provider E), 2 MergeChannelsRequest (Provider B to Provider E), 3 MergeChannelsConfirm (Provider E to Top MCS Provider), 4 MergeChannelsConfirm (Provider F to Top MCS Provider), 5 PurgeChannelsIndication (Top MCS Provider to Provider E), and 6 PurgeChannelsIndication (Top MCS Provider to Provider F).](f4fdce3ce1c0fd291f31813f83d0d0d3_img.jpg)
+
+```
+
+graph TD
+    TopMCS[Top MCS Provider]
+    ProviderA[Provider A]
+    ProviderB[Provider B]
+    ProviderC[Provider C]
+    ProviderD[Provider D]
+    ProviderE[Provider E]
+    ProviderF[Provider F]
+
+    TopMCS --- ProviderA
+    TopMCS --- ProviderB
+    TopMCS --- ProviderC
+    TopMCS --- ProviderD
+    TopMCS --- ProviderE
+    TopMCS --- ProviderF
+
+    ProviderA -- "1 MergeChannelsRequest" --> ProviderE
+    ProviderB -- "2 MergeChannelsRequest" --> ProviderE
+    ProviderE -- "3 MergeChannelsConfirm" --> TopMCS
+    ProviderF -- "4 MergeChannelsConfirm" --> TopMCS
+    TopMCS -- "5 PurgeChannelsIndication" --> ProviderE
+    TopMCS -- "6 PurgeChannelsIndication" --> ProviderF
+
+```
+
+T1602500-97
+
+Diagram illustrating Domain merger step four – Merge remaining channel ids. The diagram shows a hierarchical tree structure of MCS providers. At the top is 'Top MCS Provider'. It has four children: 'Provider A', 'Provider B', 'Provider C', and 'Provider D'. 'Provider A' and 'Provider B' are merged into 'Provider E'. 'Provider E' and 'Provider F' are merged into 'Top MCS Provider'. The diagram shows the sequence of messages: 1 MergeChannelsRequest (Provider A to Provider E), 2 MergeChannelsRequest (Provider B to Provider E), 3 MergeChannelsConfirm (Provider E to Top MCS Provider), 4 MergeChannelsConfirm (Provider F to Top MCS Provider), 5 PurgeChannelsIndication (Top MCS Provider to Provider E), and 6 PurgeChannelsIndication (Top MCS Provider to Provider F).
+
+**Figure 13-4/T.125 – Domain merger step four – Merge remaining channel ids**
+
+## 13.7 Channel id allocation
+
+Channel ids in the range of 1001 and above are allocated dynamically at the top MCS provider during the processing of primitive requests MCS-ATTACH-USER, MCS-CHANNEL-JOIN zero, and MCS-CHANNEL-CONVENE. There is no requirement that the values allocated fit any particular pattern. Rather, it is desirable that the values be randomly dispersed over the allowed range. This makes it more likely that two domains that operate independently for a substantial period of time may later be merged without conflicts in their respective allocation of channel ids. It also defends against recycling ids too quickly within a single domain as they are released from one use and then reallocated for a different use. Applications using MCS should have time to adjust to the disappearance of a channel or user id before it returns in a new incarnation.
+
+In situations where the seamless merging of active domains is required, conflicts may be avoided by selecting channel ids from a subrange unique to each provider. Subranges may be created by dividing the dynamically allocated channel ids 1001..65535 into several bands. Furthermore, within a subrange, ids may be allocated sequentially in one direction, from top or bottom. Providers that employ subrange allocation shall still obey all aspects of this protocol, including the procedure for domain merger. They shall thereby accommodate peer providers that may lack unique subranges.
+
+NOTE – It is a matter of local implementation how a provider chooses a subrange from which to allocate. Pre-arranged conferences may be banded by a network-management system.
+
+Token ids, unlike channel ids, are not allocated, and the dividing line of value 1001 has no significance for them. A free token id with a given value is statically available to be grabbed or inhibited at any time, subject only to a domain limit on the total number in use at once.
+
+## 13.8 Token status
+
+Token status is defined formally in clause 7. It is returned as a component of token confirm MCSPDUs and is used to update the record for a token id in the information base of subordinate
+
+providers. Token status is not necessarily reported directly through a confirm primitive to the initiating user but may be reported indirectly through a result value.
+
+When more than one token status value describes the relationship of a given user to a specified token id, the order of preference shall be as follows. *Self-recipient* shall be reported first, if it fits, to remind the user that they must respond to an MCS-TOKEN-GIVE indication. Next preferred is *self-giving*, to remind the user that they are engaged in an uncompleted operation, followed by *self-grabbed* or *self-inhibited*. Last in order are the remaining status values, reflecting the token's current state as a result of its sole use by other parties.
+
+An MCS provider relies on the specified preference for token status values in order to update the token state correctly in its information base.
+
+## 13.9 Capabilities Notification
+
+Through extensibility mechanisms built into the V3 protocol, capabilities can be implemented in MCS by adding components to T.125 PDUs, or even by adding new PDUs, without requiring a new version of the protocol. A given node can act on PDU parameters it understands and simply relay unrecognized parameters intact.
+
+In order for a given capability to be exercised, certain conditions may have to be met by the nodes which comprise the domain. These conditions, or rules, could include such things as a degree of participation by other nodes, or the presence or absence of Version 2 nodes. For example, a certain capability may require the participation of every node in the domain in order to be exercised. On the other hand, another capability may require only two or more nodes to participate in order to be useful. In other words, a set of rules is associated with each capability and a given node must make a decision whether to exercise this capability based on these rules and the state of the domain.
+
+The **CapabilitiesNotificationRequest** and **CapabilitiesNotificationIndication** PDUs provide a means to facilitate capabilities notification in a V3 summit. The **CapabilitiesNotificationRequest** PDU carries capabilities which various nodes wish to be added to or removed from the summit capabilities list. In addition, this PDU is also used to notify other nodes of status changes in regard to V2 connections. The **CapabilitiesNotificationIndication** PDU is used to effect changes to the summit capabilities list and to inform of V2 connection status. For the remainder of this subclause, a **CapabilitiesNotificationRequest** PDU will be referred to as a "**Request**", and a **CapabilitiesNotificationIndication** PDU will be referred to as an "**Indication**".
+
+### 13.9.1 Capability IDs
+
+A capability is a high level behavior of the system, most likely requiring the cooperation between two or more nodes. As capabilities are developed, they are assigned a Capability ID. This ID could be standardized and documented in T.125. A Capability ID thus designates a set of PDU parameters (not necessarily in the same PDU), possibly a set of values for those parameters, and the required processing of those PDUs by participating nodes.
+
+### 13.9.2 Version 3 Summits
+
+It cannot be expected that a domain hierarchy will consist solely of V3 nodes. Due to the stipulation of T.125 (Revised) that the protocol version be negotiated on a per connection basis, it is possible for a domain to consist of a mixture of V2 and V3 nodes. T.125 (Revised) also stipulates that a V3 capable node must source and sink only V2 PDUs if its upward connection negotiates to the V2 protocol with its superior node. These nodes are equivalent to V2 nodes, and are considered as such for the remainder of subclause 13.9.
+
+A V3 summit is a group of contiguously connected V3 nodes situated at the top of the domain hierarchy. The top provider in the domain must be a V3 node in order for a V3 summit to exist. The
+
+nodes which comprise the summit are able to exchange capabilities information, but are not capable of exchanging this information with any V2 nodes in the domain. This may or may not hinder the use of a given capability. Within the V3 summit, the top provider for the domain is referred to as the "V3 summit provider".
+
+### **13.9.3 Rules of capability selection**
+
+There are several factors which influence whether a given capability is to be exercised in a V3 summit. These factors are predominantly a measure of participation in the capability by other nodes. For example, suppose a capability required all nodes in the domain to perform a given task at the same time. A PDU could be exchanged between all nodes which contained a reference time for when the given task was to be performed. In order for this to happen, all nodes in the domain would have to participate, by definition. This would not be possible if the domain contained either a V2 node, or a V3 node which did not have this capability implemented. On the other hand, some capabilities may not require domain-wide or summit-wide participation.
+
+#### **13.9.3.1 Presence of V2 nodes in the domain**
+
+Any V3 node in a summit will be aware if it has a downward connection to a V2 node. Via the proposed V3 protocol changes, it will be possible for the V3 node to notify all V3 nodes in the summit that a V2 node has a connection to the summit. Some capabilities may be useless in a domain where V2 nodes are present. Other capabilities may not be affected at all. By knowing whether a V2 node is connected to the summit, an individual node can make the decision whether to exercise a given capability.
+
+#### **13.9.3.2 V3 node participation**
+
+In order to be exercised, capabilities will require a certain amount of participation by nodes in the V3 summit. Each capability will be categorized as requiring either "global" or "partial" participation. Global participation means that every node in the summit must participate in order for the capability to be exercised. Partial participation requires the cooperation of two or more nodes. This participation requirement is known as a "participation indicator". Capabilities with a partial participation indicator are known as "partial capabilities". Capabilities with a global participation indicator are known as "global capabilities". Knowing the participation indicator for a given capability allows the summit provider to make a decision as to whether that capability should be made available to the summit.
+
+#### **13.9.3.3 Intervening V3 nodes**
+
+Because of ASN.1 extension marks, it is possible for a V3 node to receive a PDU with components the node does not recognize. The node will, however, recognize the PDU these components are associated with and relay the unrecognized components intact along with the PDU.
+
+In addition to extending existing PDUs, the V3 protocol allows for the addition of new PDUs. The problem with this is that nodes which do not recognize new PDUs have no idea how to route them. In this situation, it would be advantageous for a node which sourced such a PDU to know whether the intervening nodes on the path to the V3 summit provider supported the PDU. If so, the sending node could assume that each node along the path would know how to deal with the PDU. The proposed changes to the V3 protocol contains a facility whereby any node, for each capability, is informed whether that capability is supported by the intervening nodes.
+
+#### **13.9.3.4 Capability class**
+
+Once it has been decided that a certain capability is to be made available to the V3 summit, there must be a facility to associate a value with that capability, if need be. This is done via the Capability
+
+Class. Each capability would be classified as being in the class MIN, MAX, or NULL. For capabilities of class MIN, the V3 summit provider is responsible for determining the minimum value to be used for a capability by selecting the minimum value requested of every participating node. Likewise for capabilities of class MAX, the V3 summit provider is responsible for determining the maximum value to be used. A capability of class NULL has no value associated with it.
+
+Once a capability is standardized, it is expected that the associated capability class is also standardized. Every time a given capability is requested from a lower node, the summit provider should see only a single capability class ever associated with that capability. If the summit provider ever receives a request for a capability with a capability class different than that of an original request, the summit provider should consider this an error condition and ignore the request.
+
+### 13.9.4 Establishing the V3 summit provider
+
+Every V3 summit is initially established by a single V3 node. The V3 node will be the "top provider" in a single node domain. This summit provider is aware only of its own capabilities.
+
+Each of the summit provider's capabilities require either partial or global participation within this one-node summit. None of the partial capabilities are put in the summit capabilities list because they require, by definition, the participation of two or more nodes. The question is whether the capabilities requiring global participation are put in the list. It can be argued that "all nodes" in the summit are participating and, therefore, all the node's global capabilities should be in the summit list. If any of these global capabilities can be exercised, however, they obviously must be a capability which requires only a single node's participation. Such capabilities really are not a topic of this Recommendation. If any capability can be exercised by a single node, this protocol is irrelevant to that capability. It is for this reason that the summit capabilities list is considered to be empty when the summit consists of a single V3 node.
+
+### 13.9.5 Expanding the V3 summit
+
+Once the V3 summit provider is established, the summit expands as other V3 nodes connect to the summit provider. A new leaf node generates a **Request** to be sent to the summit provider. This PDU contains the capabilities, and aspects of those capabilities, which the leaf node wishes to be placed in the summit capabilities list.
+
+From this PDU, the summit provider is able to do two things. First, it can formulate state information about the capabilities requested by the new connection. Second, based on summit-wide state information, it can make a sound judgement as to which capabilities should appear in the summit capabilities list. An **Indication** is then generated and transmitted downward to inform the leaf node of the contents of the summit list, as well as the status of V2 nodes connected to the summit.
+
+In this same manner, the V3 summit can continue to grow. As new leaf nodes connect to intermediate nodes, a **Request** is generated and sent up. From the information contained in this PDU, the intermediate node will update its state information. Based on state information for its subtree and the current contents of the summit capabilities list, the intermediate node will take action, possibly resulting in a **Request** being transmitted up, or **Indications** being transmitted downward. Eventually, a **Request** may rise to the summit provider. If the summit provider determines that the summit capabilities list needs to be modified, it will generate and transmit an **Indication** downward for the purpose of informing other nodes in the summit.
+
+### 13.9.6 Processing PDU's at a leaf node
+
+Once a V3 leaf node establishes a connection to a superior V3 node, it must inform the superior node of its supported capabilities. For each capability requested, the leaf node will specify the capability ID and class. If standardized, the ID specified is that which is assigned to the capability in T.125. If
+
+the class belongs to the category MIN or MAX, the leaf node must also specify an associated value. If the class is NULL, no value is specified.
+
+In addition, the leaf node must specify the participation indicator for each capability. For any partial capability, the leaf node specifies a value of 1, indicating to the superior node that only the new leaf node itself has requested the capability below this new connection.
+
+These capabilities are packaged into the AddList component of a single **Request**. The V2NodePresent flag will be reset in the **Request**. Because this is a newly-joining leaf node, there are no V2 nodes connected to it. Also, the RemoveList component will be empty. Once packaged, this PDU is transmitted to the superior node.
+
+This newly-connected leaf node has no knowledge of the contents of the summit capabilities list. The node can expect to be informed of the contents of this list via a single **Indication** from the superior node. The contents of the list will be contained in the AddList component of the **Indication**. The RemoveList will be empty. The V2NodePresent flag will inform the leaf node whether a V2 node is currently connected to any node in the summit. From this point forward, the leaf node will be informed of any modifications to the summit list via an **Indication** from the superior node. Should the status of the connections to V2 nodes change, the leaf node will be informed of this via an **Indication** also.
+
+For each capability in the AddList component of an **Indication** received, the leaf node will be informed whether that capability is supported by the summit provider, and whether that capability is supported by each intervening node between the leaf node and the summit provider. With this information, the leaf node can decide whether to exercise a given capability.
+
+As long as a node remains a leaf node, it will never again need to send a **Request**. At such time as another node (V2 or V3) connects upward to this node, it then becomes an intermediate node. The processing of PDUs at an intermediate node is described in 13.9.7.
+
+### 13.9.7 Processing PDUs at an intermediate node
+
+When an intermediate node receives a **Request** from a downward connection, it will first update the state information for the associated connection. The node will then address each capability in the AddList and RemoveList components, as well as the V2NodePresent flag. Although several capabilities requiring action may arrive in a single **Request**, they are processed independently. As a result, the intermediate node may have need to transmit several pieces of information to adjacent nodes. The node will combine these actions so that no more than a single PDU is transmitted to any connection as a result of processing the original **Request**.
+
+#### 13.9.7.1 Maintaining state information
+
+Intermediate nodes maintain a set of state information for each downward connection. Upon receipt of a **Request** from a subnode, the intermediate node updates the state information associated with that connection. Included in this information are two lists. The first list consists of all partial capabilities requested by nodes below that connection. Each of these capabilities is tagged with a count of either 1 or 2. A value of 1 signifies that this capability has only been requested by a single node below the connection. A value of 2 signifies that two or more nodes have requested the capability.
+
+The second list consists of a set of global capabilities. In contrast to partial capabilities, global capabilities will go in the list only if they have been requested by every node below the connection. For any capability in either of the two lists, the intermediate node will also track the class of the capability and any value associated with the class.
+
+Finally, for each downward connection, a flag is maintained. This flag indicates whether a V2 node is connected to the summit below that connection.
+
+The algorithm for updating state information is simple. If the intermediate node receives a request to add a capability which is not currently in either of the two lists, the capability is added to the appropriate list, depending on the participation indicator. If a request is received to remove a capability that is currently in one of the two lists, then the capability is removed from that list.
+
+If the intermediate node receives a request to add a capability which is already in one of the two lists, the processing depends on the class and participation indicator of the capability. In the case of the MIN or MAX class, the class value in the state information is updated if different from that in the **Request**. In the case of a partial participation indicator, the associated value in the state information is updated if different.
+
+Finally, if the intermediate node ever receives a **Request** in which the V2NodePresent flag is present, the value of that flag is compared with the flag in the state information. If different, the state information is updated.
+
+#### 13.9.7.2 Processing the CapabilitiesNotificationRequest PDU
+
+An intermediate node may transmit a **Request** under the following conditions:
+
+- 1) The node receives a **Request** from a downward connection.
+- 2) The node detects the loss of a V3 connection.
+- 3) The node detects a direct connection/disconnection with a V2 node.
+
+The following subclauses describe how an intermediate node handles these conditions.
+
+##### 13.9.7.2.1 Global capabilities in the add list
+
+When an intermediate node receives a **Request** asking to add a global capability, the node examines its local copy of the summit capabilities list to determine if the requested capability is already in the list. The next action performed by the node depends on whether the capability is in the list.
+
+If the capability is not in the list, the intermediate node must determine if this was the first **Request** to come up from the connection. If so, this means the **Request** is from a newly-connected leaf node and no further action is required. Otherwise, it may be necessary to transmit a **Request** asking that the capability be added, depending on the state information of any downward connections. If the intermediate node is able to determine from its state information that the capability is now supported by every node in its subtree, then the **Request** is transmitted. This action could eventually result in the capability being added to the summit list.
+
+If the requested capability is in the list, this implies that every node in the summit supports the capability. Further processing depends on the class of the capability. If the capability is of class MIN, the intermediate node must determine if the associated value is the least of the values requested by every node in this subtree for that capability. Likewise, if the capability is of class MAX, the intermediate node must determine if the associated value is the greatest of the values requested by the other nodes. Should either of these two conditions be met, the intermediate node will transmit a **Request** upward, asking to add the capability with its associated value. This will serve to inform the superior node that there is a lesser MIN or greater MAX value down in its subtree for this specific capability. If the capability is of class NULL, no **Request** will be required. Finally, the intermediate node will generate an **Indication** to transmit to the lower node, notifying it to add the capability (and its associated value, if there is one) to its local copy of the summit capabilities list.
+
+When an intermediate node receives a **Request** from a newly-connected leaf node, the intermediate node may be required to take action due to global capabilities NOT requested by the leaf node. The
+
+first request from a leaf node contains a list of all global capabilities that node supports. If the intermediate node has global capabilities in its local copy of the summit list that are not requested by the leaf node, then the leaf node does not support those capabilities. By definition, these capabilities now become unavailable to the summit and must be removed from the summit list. At this point, the intermediate node generates a **Request** and places this capability in the RemoveList. This PDU is then transmitted upward, informing the superior node that the capability is no longer supported in this subtree. If the intermediate node has any other downward connections, it will generate an **Indication** to be transmitted downward. This **Indication** will contain the capability in the RemoveList. Finally, the intermediate node will remove the capability from its own copy of the summit capabilities list.
+
+##### 13.9.7.2.2 Global capabilities in the remove list
+
+If an intermediate node receives a **Request** asking that a global capability be removed, this implies that somewhere below the connection, a node has joined the summit that does not support the capability. This capability must now be made unavailable to the summit. The processing required here is straightforward. The node generates a **Request** asking that the capability be removed and transmits it upward. If other downward connections exist, the intermediate node generates an **Indication** asking that the capability be removed and transmits it to all downward connections (except the connection which originated the **Request**). The node then removes it from the local copy of the summit capabilities list.
+
+##### 13.9.7.2.3 Partial capabilities in the add list
+
+If an intermediate node receives a **Request** asking that a partial capability be added, the node must determine whether this is the first request, the second request, or greater than the second request for the capability. This can be determined from the intermediate node's state information.
+
+If this is the first request, the intermediate node will generate a **Request** asking that the capability be added. The value supplied with the partial participation indicator will be 1, signifying that only 1 request has been made for this capability in the subtree of the intermediate node. If it is the second request, the intermediate node will generate **Request** asking that this capability be added and a value of 2 will be supplied for the partial participation indicator. If the intermediate node determines that this capability has already been asked for at least twice, no **Request** is required.
+
+Next, the intermediate node must examine its local copy of the summit list to see if the capability is in the list. If so, the node will generate an **Indication** with the capability in the AddList component and transmit it to the requesting connection.
+
+The intermediate node must also take the class of the capability into account. This aspect of the processing is similar to that explained previously for global capabilities. If a capability comes in with the least MIN value in the subtree or the greatest MAX value in the subtree, then the superior node must be made aware of this via a **Request**.
+
+##### 13.9.7.2.4 Partial capabilities in the remove list
+
+When an intermediate node receives a **Request** asking that a partial capability be removed, the node must determine whether the removal would affect the number of requests for the capability in the subtree. If so, the intermediate node must generate a **Request** for that capability, asking that the capability be added with a partial participation indicator of 1, or ask that the capability be removed completely, depending on the change in status.
+
+If the intermediate node can determine the direct effect on the summit list, the node can adjust its own local copy of the list and generate **Indications** to notify the other downward connections. If the
+
+node cannot determine the effect, then any adjustment will eventually come down from a higher node which can determine the effect.
+
+##### 13.9.7.2.5 Processing the V2 node present flag
+
+In practice, although not required, an intermediate node will receive a **Request** which contains a V2NodePresent flag or a capabilities list (AddList and/or RemoveList), but usually not both.
+
+For each downward connection, an intermediate node keeps a status of whether a V2 node is connected to the summit below the connection. The first time an intermediate node learns that a V2 node has connected from below, including directly to the node itself, it will generate a **Request** containing only the V2NodePresent flag, which will be set. This **Request** will then be sent upward. Also, an **Indication** with the same contents will be sent to all downward connections, except for the connection which may have provided the original **Request**. In this manner, every node in the summit will learn of the existence of the V2 node. Each node can take this into account when deciding whether to exercise a given capability.
+
+By the same token, an intermediate node may receive a **Request** informing the node that all previous V2 connections have broken from the subtree. With each of these **Requests**, the intermediate node can determine whether any V2 nodes are now connected to its subtree. If others still exist, the intermediate node takes no action. If all V2 nodes disconnect, however, the intermediate node generates a **Request** with the V2NodePresent flag reset and sends it upward.
+
+If all the V2 nodes connected to the summit disconnect, the summit provider will detect this by seeing that none of the downward connections contains a V2 node in its subtree, and that there are no V2 nodes connected directly to the summit provider. When this occurs, the summit provider generates an **Indication** with the V2NodePresent flag reset and transmits it throughout the summit.
+
+##### 13.9.7.2.6 Processing V3 node disconnections
+
+When a given node in the summit detects that a downward connection has been broken, all state information for that connection is discarded. The state information for the remaining downward connections, if any, could affect the contents of the summit capabilities list.
+
+If any global capabilities are supported by every node in the summit except for one or more nodes below the lost connection, those capabilities can now be added to the summit list. If the number of requests for a partial capability in the summit drops below two as a result of losing nodes below the lost connection, those capabilities must be removed from the summit. The process to adapt to the lost connection begins with the node which detects that the connection is broken. The node handles this by treating the situation as if a **Request** has been received asking that every capability in the state information for that connection be removed. The connection would then process this in the manner as described in 13.9.7.2.
+
+#### 13.9.7.3 Processing the CapabilitiesNotificationIndication PDU
+
+At times, an intermediate node will receive an **Indication** from its upward connection. The indication will instruct the intermediate node to either add or remove capabilities from the summit list. These modifications will be made to the "local" summit list, and the indication will be forwarded to each downward connection. If this is the first **Indication** sent on a connection, the intermediate node will simply transmit the entire summit list via the AddList component of the **Indication**. If an intermediate node does not support a capability, the node must reset the flag which indicates intermediate node support.
+
+#### 13.9.7.4 Processing PDUs at the summit provider
+
+The manner in which the summit provider processes PDUs is nearly identical to that of an intermediate node. Upon receipt of a **Request** from a downward connection, the summit provider will update the state information for the associated connection the same as an intermediate node, as described in 13.9.7.1. The summit provider deals with global capabilities and partial capabilities identically to intermediate nodes, with the obvious exception that no **Requests** will be sent to a superior node. With each request to add or remove a capability, the summit provider decides whether the summit list is to be modified. If deemed so, the summit provider will generate an **Indication** filled in with the appropriate capabilities to add or subtract and transmit this PDU down appropriate connections.
+
+This protocol has been designed so that each node that determines that the summit capabilities list must change will initiate the change by notifying its downward connections, and by notifying its superior node. In this manner, the summit list will get update across the summit.
+
+If a node does not have enough information to determine whether a change to the summit list can be made, it will send a **Request** up to the next higher node, who may in turn be able to decide. All decisions of this matter can ultimately be resolved by the summit provider.
+
+## 13.10 Protocol version arbitration
+
+This Recommendation defines three protocol versions (see clause 9 for details). However, Recommendation T.120 specifies that version 1 is obsolete. A node can refuse to support version 1 by requiring version 2 (or higher) during connection establishment (if a remote node *only* supports version 1, the connection can be rejected). For nodes that wish to support version 1 for backward compatibility, it is suggested that no mixing of other protocol versions in the same domain be allowed [as per the rules of Recommendation T.125 (1994)].
+
+Recommendation T.120 will be (or has been) modified to allow for versions 2 or 3. The protocol version number parameter of the domain parameters shall be used to negotiate the capability to source and sink version 3 PDUs. A node which implements version 3 must also be able to source and sink version 2 PDUs.
+
+The protocol version number parameter is negotiated independently for each connection (with one restriction, which is described below). Each version 3 node must maintain information regarding protocol versions selected by its upward and downward connections. Translation between versions must be provided for on any non-leaf node which implements version 3 of the protocol (this is discussed in detail in 13.11).
+
+A version 3 capable node that has negotiated the use of version 2 on its upward connection will *only* negotiate the use of version 2 on its downward connections. This has the effect of concentrating the use of version 3 at the top of the domain hierarchy (this area of version 3 usage is referred to as the "V3 Summit").
+
+A version 3 capable node that has negotiated the use of version 3 on its upward connection will attempt to negotiate the use of version 3 on its downward connections (although version 2 will be accepted when necessary).
+
+## 13.11 Protocol version interoperability
+
+Translation from version 2 to version 3 is accomplished by copying the parameters from a version 2 PDU to an equivalent version 3 PDU.
+
+Translation from version 3 to version 2 is accomplished by copying the parameters from a version 3 PDU to an equivalent version 2 PDU. Version 3 parameters that do not correspond to valid version 2 parameters are discarded. Version 3 PDUs with no version 2 equivalent are also discarded.
+
+When a node receives a version 3 PDU that it does not recognize, the PDU is discarded (this is not an error).
+
+When a node receives a version 3 PDU that *does* recognize, the PDU is processed normally. If the PDU contains any parameters that the receiver does not recognize, they are simply ignored. If the PDU must be forwarded to another node using protocol version 3, all parameters are forwarded intact (including those that were not locally recognized).
+
+Considerations for using non-standard parameters in multi-protocol conferences:
+
+NOTE 1 – Prior to utilizing non-standard parameters, the implementer should ensure version 2 and version 3 nodes interoperate successfully. No information comprising a version 3 PDU in the form of a non-standard parameter, or as a standard parameter beyond the extension marker, can be delivered to a version 2 node via a version 2 PDU. Non-standard parameters are therefore only suitable for use for extensions whose absence will not effect basic operation at either V2 or V3 nodes (fail safe operation). The precise procedures to be used by an MCU or other intervening nodes should be thought about in detail to ensure successful interoperability.
+
+NOTE 2 – When using non-standard parameters, it must be kept in mind that such usage be an interim solution until equivalent functionality has been standardized.
+
+NOTE 3 – This Recommendation describes a mechanism for information exchange between nodes for the purpose of ascertaining non-standard capabilities available to a version 3 summit. Scalability aspects should be considered, it being likely that in larger conferences the probability will be decreased that any non-standard capabilities will be found to be in common.
+
+NOTE 4 – The processing cost of translating between V2 and V3 PDUs should be considered. Besides an MCU having to generate version 2 PDUs by dropping certain parameters from an equivalent version 3 PDU, as well as generating version 3 PDUs by generating parameters from an equivalent version 2 PDU, the cost of actually including non-standard parameters in PDUs is relatively high. The minimal encoding appears to be about 8 octets, excluding the size of any data passed in the parameter. This is equal to the MCS header of standard parameters in a data PDU and is an additional drain on bandwidth. Upon receipt of any non-standard parameter, a version 3 node must parse its key and then look up the manufacturer codes to determine its meaning, if known. This is a drain on processing power that should be minimized whenever possible. Procedures to be followed by nodes that do not understand non-standard parameters are specified in this subclause.
+
+# ANNEX A
+
+# **Multicast adaptation protocol**
+
+## **A.1 Scope**
+
+This Annex defines a protocol that allows multicast services to be used in a T.120 conference. This protocol is independent of the type of network on which it is used. Issues that are specific to a given network, such as address format and multicast group address allocation, are outside the scope of this Annex. This protocol also allows for the transfer of unreliable data.
+
+Figure A.1-1 illustrates how the Multicast Adaptation Protocol (MAP) fits into the T.120 model. MAP handles the translation of T.122 services to multicast services. Underneath MAP can be a variety of data delivery protocols, such as TCP, UDP, MTP/SO, and RMP (MTP/SO and RMP are example proposals for reliable multicast on IP networks).
+
+![Figure A.1-1/T.125 – T.120 model showing relationship of MAP to other layers. The diagram illustrates a layered network architecture. At the top is a box labeled 'T.125'. Below it are two boxes: 'X.224' on the left and 'Annex A/T.125 – MAP' on the right. Below 'X.224' are 'null + SCF' and 'Q.922'. Below 'Q.922' are 'ISDN' and 'PSTN'. Below 'Annex A/T.125 – MAP' are 'RFC 1006', 'UDP', 'MTP/SO', 'RMP', and 'Other'. Below 'RFC 1006' is 'TCP'. Below 'TCP' is 'IP'. Below 'UDP', 'MTP/SO', 'RMP', and 'Other' is 'IP'. Double-headed arrows indicate bidirectional relationships between adjacent layers. A reference 'T1600670-97' is at the bottom right.](3481cde1adf61b0452dd6489dada6d6a_img.jpg)
+
+Figure A.1-1/T.125 – T.120 model showing relationship of MAP to other layers. The diagram illustrates a layered network architecture. At the top is a box labeled 'T.125'. Below it are two boxes: 'X.224' on the left and 'Annex A/T.125 – MAP' on the right. Below 'X.224' are 'null + SCF' and 'Q.922'. Below 'Q.922' are 'ISDN' and 'PSTN'. Below 'Annex A/T.125 – MAP' are 'RFC 1006', 'UDP', 'MTP/SO', 'RMP', and 'Other'. Below 'RFC 1006' is 'TCP'. Below 'TCP' is 'IP'. Below 'UDP', 'MTP/SO', 'RMP', and 'Other' is 'IP'. Double-headed arrows indicate bidirectional relationships between adjacent layers. A reference 'T1600670-97' is at the bottom right.
+
+**Figure A.1-1/T.125 – T.120 model showing relationship of MAP to other layers**
+
+## A.2 Normative references
+
+The following ITU Recommendations and International Standards contain provisions which, through reference in this text, constitute provisions of this Annex. At the time of publication, the editions indicated were valid. All Recommendations and Standards are subject to revision, and parties to agreements based on this Annex are encouraged to investigate the possibility of applying the most recent edition of the Recommendations and Standards listed below. Members of IEC and ISO maintain registers of currently valid International Standards. The ITU-T Secretariat maintains a list of the currently valid ITU-T Recommendations.
+
+- CCITT Recommendation T.35 (1991), *Procedure for the allocation of CCITT defined codes for non-standard facilities*.
+- ITU-T Recommendation T.120 (1996), *Data protocols for multimedia conferencing*.
+- ITU-T Recommendation T.122 (1998), *Multipoint Communication Service – Service definition*.
+- ITU-T Recommendation T.123 (1996), *Network specific data protocol stacks for multimedia conferencing*.
+- ITU-T Recommendation X.214 (1995) | ISO/IEC 8072:1996, *Information technology – Open Systems Interconnection – Transport service definition*.
+- ITU-T Recommendation X.680 (1997) | ISO/IEC 8824-1:1998, *Information technology – Abstract Syntax Notation One (ASN.1): Specification of basic notation*.
+- ITU-T Recommendation X.691 (1997) | ISO/IEC 8825-2:1998, *Information technology – ASN.1 encoding rules – Specification of Packed Encoding Rules (PER)*.
+
+## A.3 Definitions
+
+This Annex defines the following terms.
+
+**A.3.1 data flow:** This is a stream of data being transmitted from a sender to all interested receivers. Data flows are uniquely identified by the following five fields: sender ID; channel ID; reliability level; priority; and data type. Each data flow has a separate sequence counter, and may be routed differently from every other data flow.
+
+**A.3.2 data type:** All MCS data PDUs are either non-uniform (source-ordered), uniform (globally-ordered); or proxy data (which is non-uniform data that is to be sent via multicast by the Multicast Group Provider on behalf of the originator).
+
+**A.3.3 MAP connection:** This is an MCS connection between two nodes through MAP. One MAP connection is, in turn, made up of one or more transport connections. There is no need for adjacent nodes to have common multicast protocols in order to make a MAP connection.
+
+**A.3.4 MCS connection:** This is a connection between two MCS providers that are adjacent in the domain hierarchy. This can be through MAP or directly through one of the protocol stacks defined in Recommendation T.123.
+
+**A.3.5 metachannel:** This is an MCS channel at a given reliability level and in a given priority range. MAP assigns multicast groups to metachannels.
+
+**A.3.6 multicast:** This refers to the ability to send a packet of data to more than one recipient with one operation.
+
+**A.3.7 multicast group:** This is a group of receivers that have expressed interest in receiving certain data via multicast. The group is uniquely identified by a Multicast Group Address.
+
+**A.3.8 multicast group address:** This is a network address that uniquely identifies a Multicast Group. Data sent to this address are delivered, via multicast, to all reachable nodes that have joined the Multicast Group.
+
+**A.3.9 multicast group provider:** This is a node that either has no upward MAP connection, or has an upward MAP connection, but no common multicast protocols with the node above. The Multicast Group Provider is responsible for associating metachannels with multicast groups. Once this association is made, data transmitted to the metachannel can be delivered via multicast.
+
+**A.3.10 multicast island:** This is a group of contiguous MAP connections within an MCS domain that have agreed to the use of a particular multicast transport protocol for a given metachannel.
+
+**A.3.11 multicast sender:** This is the node in a multicast island that transmits a given data flow via multicast. For non-uniform data, this is the point-of-entry node. For uniform and proxy data, this is the Multicast Group Provider.
+
+**A.3.12 point-of-entry:** This is the node in a multicast island at which a particular data flow enters the island.
+
+**A.3.13 reliability level:** This refers to the level of guarantee that is provided for data transfer. MAP supports two reliability levels: fully reliable (guaranteed delivery); and unreliable (no guarantee).
+
+**A.3.14 sequence number:** This is a rolling number that is associated with each data flow. This number is used for the re-assembly of unreliable data, and to facilitate seamless transitions between unicast and multicast data transfer.
+
+**A.3.15 transport connection:** This is a unicast connection through one of the protocol stacks below MAP.
+
+**A.3.16 transport protocol:** These are the protocols that are used by MAP to deliver data. There are four types of transport protocols: reliable unicast; reliable multicast; unreliable unicast; and unreliable multicast. Nodes in the domain arbitrate transport protocols before using them.
+
+## A.4 Abbreviations
+
+This Annex uses the following abbreviations.
+
+|        |                                                      |
+|--------|------------------------------------------------------|
+| ATM    | Asynchronous Transfer Mode                           |
+| IP     | Internet Protocol                                    |
+| ISDN   | Integrated Services Digital Network                  |
+| MAP    | Multicast Adaptation Protocol                        |
+| MAPPDU | Multicast Adaptation Protocol – Protocol Data Unit   |
+| MAPSAP | Multicast Adaptation Protocol – Service Access Point |
+| MCS    | Multipoint Communication Service                     |
+| MTP/SO | Multicast Transport Protocol/Self-Organizing         |
+| PDU    | Protocol Data Unit                                   |
+| PSTN   | Public Switched Telephone Network                    |
+| RMP    | Reliable Multicast Protocol                          |
+| SCF    | Synchronization and Convergence Function             |
+| TCP    | Transmission Control Protocol                        |
+| UDP    | User Datagram Protocol                               |
+
+## A.5 Overview
+
+When using unicast-only transport protocols, T.125 creates point-to-point connections to "construct" a multipoint conference. Data flows across these connections, following the hierarchy of the domain, until it reaches all intended recipients. On networks that are capable of true multicast, this is extremely wasteful, since the same data is sometimes transmitted multiple times on the same physical device. This Annex describes a protocol which allows for the use of multicast data transfer in a T.120 conference. This protocol is referred to as the Multicast Adaptation Protocol (MAP).
+
+MAP is completely independent of the underlying network. It is insulated from the network by a transport protocol that meets the service requirements defined in 5.2. Some of the examples in this Annex reference protocols that are implemented on top of the Internet Protocol (IP), but MAP can also be used on other types of multicast networks, such as ATM multicast or Frame Relay multicast.
+
+To manage multicast, MAP needs to know about more than just unicast connections. MAP also needs to know about domains and channels. This information allows it to properly group unicast connections, and use multicast in the most efficient manner possible. Management of the domains and channels is still part of MCS, but this information is shared with MAP as needed.
+
+At a high level, the problem of using multicast in T.120 can be broken into the following three parts:
+
+- 1) *Allocation of multicast groups:* Before multicast can be used, someone must allocate a multicast group address that is not currently being used by anyone else on the reachable network. MAP determines which node allocates the address. How the allocation is done, however, is outside the scope of MAP (this is the focus of work in other standards groups).
+
+- 2) *Distribution of multicast groups*: Once a multicast group address is allocated, it is necessary to distribute it to those nodes that need to use it. MAP handles the distribution of multicast group addresses.
+- 3) *Management of multicast data transfer*: It is not enough to simply send the address of a multicast group and tell everyone to start using it. There are many reasons why multicast may not work uniformly throughout the domain. It is therefore necessary to "test" the underlying network to see who can receive multicast data (and from whom). MAP performs this test and uses multicast wherever it can. If a given node cannot receive data via multicast for some reason, then data is delivered to that node via unicast.
+
+MAP also handles the dynamic selection of both unicast and multicast transport protocols. These protocols are arbitrated automatically between any two nodes that are communicating with MAP. Once these protocols are selected, MAP can facilitate the efficient delivery of data within the domain. MAP is a separate layer above these transport protocols.
+
+### A.5.1 The use of multicast
+
+MAP supports the transmission of data at two different reliability levels, which directly affects the use of multicast. Different reliability levels will typically use different transport protocols, and will therefore usually use different multicast groups. MAP may also use different multicast groups for different priority ranges (to allow different priorities to be independently flow controlled). This Annex uses the term *metachannel* to indicate an MCS channel at a given reliability level and within a given priority range.
+
+To enable the use of multicast, MAP assigns a multicast group to each metachannel in each multicast island (multicast islands are fully described in A.5.2). The only exception to this is User ID channels, which are not assigned multicast groups (there is only one potential receiver listening to a User ID channel, which violates the concept of multicast).
+
+MAP can exercise a great deal of flexibility in how it performs group assignments. It could, for example, assign the same multicast group to every metachannel (to minimize the number of multicast groups). Or it could assign a separate multicast group to each metachannel (to reflect the fact that each metachannel can have a different set of interested receivers). These group assignments are controlled by a set of policies that can adapt over time, as network technology evolves.
+
+When data is transmitted, MAP will use the channel, reliability level, and priority to select the appropriate multicast group. This allows the data to be delivered directly to the intended recipients, without propagating through the domain hierarchy (when multicast is working).
+
+### A.5.2 Multicast islands
+
+Multicast cannot always be used to deliver data to every node in a domain. Some nodes may be connected to the domain via networks that are not capable of multicast (such as PSTN or ISDN). It is also possible for two groups of multicast capable nodes to be separated in the domain hierarchy by a multicast incapable connection. It is therefore necessary to recognize the existence of "multicast islands" within a domain.
+
+A multicast island is a group of contiguous MAP connections within an MCS domain that have agreed to the use of a particular multicast transport protocol for a given metachannel.
+
+Figure A.5-1 depicts a conference of 10 nodes. Each of the connections making up the conference is labeled with the transport protocol(s) that the adjacent nodes have agreed to use for data transfer. "PSTN" and "ISDN" refer to the protocol stacks defined in Recommendation T.123. "TCP | MTP/SO" indicates a MAP connection that is using TCP for unicast transport, and MTP/SO for multicast transport (for a given metachannel). Nodes 1, 2, 4, and 5 are in multicast island A,
+
+while Nodes 3, 6, 7, 8, and 9 are in multicast island B. These islands are separate because the connection between Nodes 1 and 3 is PSTN (this connection cannot be used to convey multicast control information).
+
+![Figure A.5-1/T.125: Multicast islands split by non-multicast connections. The diagram shows two multicast islands, A and B, separated by non-multicast connections. Multicast Island A (dashed box) contains Nodes 1, 2, 4, and 5. Node 1 is at the top, connected to Node 2 below it. Node 2 is connected to Node 4 and Node 5. Multicast Island B (dashed box) contains Nodes 3, 6, 7, 8, and 9. Node 3 is at the top, connected to Node 6 and Node 7. Node 6 is connected to Node 8 and Node 9. Node 7 is connected to Node 10. Node 10 is connected to Node 7 via an ISDN connection. The connection between Node 1 and Node 3 is labeled PSTN. The connection between Node 2 and Node 3 is labeled TCP | MTP/SO. The connection between Node 6 and Node 7 is labeled TCP | MTP/SO. The connection between Node 8 and Node 9 is labeled TCP | MTP/SO. The connection between Node 9 and Node 10 is labeled ISDN. The diagram is labeled T1602510-97.](701f4311e49f346390759520fcd19af4_img.jpg)
+
+Figure A.5-1/T.125: Multicast islands split by non-multicast connections. The diagram shows two multicast islands, A and B, separated by non-multicast connections. Multicast Island A (dashed box) contains Nodes 1, 2, 4, and 5. Node 1 is at the top, connected to Node 2 below it. Node 2 is connected to Node 4 and Node 5. Multicast Island B (dashed box) contains Nodes 3, 6, 7, 8, and 9. Node 3 is at the top, connected to Node 6 and Node 7. Node 6 is connected to Node 8 and Node 9. Node 7 is connected to Node 10. Node 10 is connected to Node 7 via an ISDN connection. The connection between Node 1 and Node 3 is labeled PSTN. The connection between Node 2 and Node 3 is labeled TCP | MTP/SO. The connection between Node 6 and Node 7 is labeled TCP | MTP/SO. The connection between Node 8 and Node 9 is labeled TCP | MTP/SO. The connection between Node 9 and Node 10 is labeled ISDN. The diagram is labeled T1602510-97.
+
+**Figure A.5-1/T.125 – Multicast islands split by non-multicast connections**
+
+Multicast islands can also be split as a result of selecting different multicast transport protocols for a given metachannel. Figure A.5-2 depicts a conference with the same domain hierarchy as Figure A.5-1, but with different protocol selections. Nodes 1, 2, 3, 4, and 5 are in multicast island A, and have agreed to use RMP for multicast transport. Nodes 3, 6, 7, 8, 9, and 10 are in multicast island B, and have agreed to use MTP/SO for multicast transport. Note that Node 3 is in both multicast islands, acting as a bridge between them.
+
+![Figure A.5-2/T.125: Multicast islands split by multicast protocol selection. The diagram shows two multicast islands, A and B, separated by multicast protocol selection. Multicast Island A (dashed box) contains Nodes 1, 2, 4, and 5. Node 1 is at the top, connected to Node 2 below it. Node 2 is connected to Node 4 and Node 5. Multicast Island B (dashed box) contains Nodes 3, 6, 7, 8, 9, and 10. Node 3 is at the top, connected to Node 6 and Node 7. Node 6 is connected to Node 8 and Node 9. Node 7 is connected to Node 10. Node 10 is connected to Node 7 via an ISDN connection. The connection between Node 1 and Node 3 is labeled TCP | RMP. The connection between Node 2 and Node 3 is labeled TCP | RMP. The connection between Node 6 and Node 7 is labeled TCP | MTP/SO. The connection between Node 8 and Node 9 is labeled TCP | MTP/SO. The connection between Node 9 and Node 10 is labeled TCP | MTP/SO. The diagram is labeled T1600690-97.](a0eb8d30ac11ba97b2733c187b89ff22_img.jpg)
+
+Figure A.5-2/T.125: Multicast islands split by multicast protocol selection. The diagram shows two multicast islands, A and B, separated by multicast protocol selection. Multicast Island A (dashed box) contains Nodes 1, 2, 4, and 5. Node 1 is at the top, connected to Node 2 below it. Node 2 is connected to Node 4 and Node 5. Multicast Island B (dashed box) contains Nodes 3, 6, 7, 8, 9, and 10. Node 3 is at the top, connected to Node 6 and Node 7. Node 6 is connected to Node 8 and Node 9. Node 7 is connected to Node 10. Node 10 is connected to Node 7 via an ISDN connection. The connection between Node 1 and Node 3 is labeled TCP | RMP. The connection between Node 2 and Node 3 is labeled TCP | RMP. The connection between Node 6 and Node 7 is labeled TCP | MTP/SO. The connection between Node 8 and Node 9 is labeled TCP | MTP/SO. The connection between Node 9 and Node 10 is labeled TCP | MTP/SO. The diagram is labeled T1600690-97.
+
+**Figure A.5-2/T.125 – Multicast islands split by multicast protocol selection**
+
+Protocol selection is performed differently for unicast and multicast protocols. Unicast protocols are selected *per MCS connection*. The selected unicast protocols are used to transfer data between nodes that are adjacent in the MCS domain hierarchy. It is perfectly valid for different connections to use different unicast protocols. Multicast protocols are selected *per metachannel*. When mapping a metachannel to multicast, each MAP node will select the multicast protocols to be used by nodes beneath it. This selection process defines the boundaries of the multicast island *for that metachannel*. It is possible for multicast island boundaries to vary for different metachannels.
+
+As a rule, each node should select the multicast protocols that will result in fewer, larger multicast islands. When possible, each node should select the same multicast protocol that was selected for it by the node above. In Figure A.5-2, Nodes 6 and 7 must have indicated that they do not support RMP, or else Node 3 would have selected it. This split in the multicast islands is the result of support for different multicast transport protocols.
+
+This Annex refers to the unicast and multicast protocols collectively as *transport protocols*. Nodes that are adjacent in the MCS domain hierarchy will perform arbitration in order to agree on the set of transport protocols that can be used in the conference. During arbitration, the adjacent nodes *must* select a single reliable unicast protocol (and, optionally, a single unreliable unicast protocol). They will also agree on a set of zero or more multicast protocols that can be used at each reliability level. When mapping a metachannel to multicast, a node will only select multicast protocols that some downward nodes have agreed to support during arbitration.
+
+### A.5.3 Multicast group providers
+
+Within each multicast island, there is one node who is responsible for the allocation of multicast group addresses. This node is referred to as the Multicast Group Provider.
+
+The Multicast Group Provider is the node that either has no upward MAP connection, or has an upward MAP connection, but no common multicast protocols with the node above. The Top Provider for the domain may also be the Multicast Group Provider for a multicast island, but this is not necessary. In Figures A.5-1 and A.5-2, Node 1 is the Multicast Group Provider for multicast island A, while Node 3 is the Multicast Group Provider for multicast island B.
+
+### A.5.4 Data ordering
+
+MCS allows for two types of data ordering: non-uniform (source ordered); and uniform (globally ordered).
+
+Non-uniform data is normally sent to the multicast group at its initial "point-of-entry" to the multicast island. The point-of-entry is simply the node at which the data enters the multicast island. This is not the node at which the sending application is attached if that node is outside the multicast island. In Figure A.5-1, if Node 10 transmits data, Node 7 is the point-of-entry for multicast island B, while Node 1 is the point-of-entry for multicast island A.
+
+Optionally, a point-of-entry node can choose to use the Multicast Group Provider as a multicast proxy. When using this option, non-uniform data is first sent upward via unicast, where it is then sent to the multicast group by the Multicast Group Provider. This is discussed more in A.8.4.
+
+In order to guarantee global ordering, uniform data must be routed upward to the Top Provider via unicast. This data flow has an "upward" point-of-entry, but this is not an interesting concept, and will not be discussed further. The data are sent to the multicast group at the "downward" point-of-entry on its way back down (for uniform data, the downward point-of-entry will simply be referred to as the point-of-entry). In Figure A.5-1, if Node 10 transmits uniform data, it will first be unicast upward to the Top Provider. On the way back down, Node 1 is the point-of-entry for multicast island A, while Node 3 is the point-of-entry for multicast island B. For uniform data, the point-of-entry will *always* be the Multicast Group Provider for each multicast island.
+
+### A.5.5 Use of multicast and unreliable unicast
+
+All control data is sent over the reliable unicast connections. **MAPData** is the only MAPPDU ever transmitted via multicast or unreliable unicast. Table A.5-1 summarizes how MAP uses each of the four transport protocol types.
+
+**Table A.5-1/T.125 – Use of transport protocol types**
+
+|            | Unicast                                                                                                                                                                                                                          | Multicast                                                                                                                                                                                    |
+|------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Reliable   | Any MAPPDU<br><br><b>MAPData</b> can contain any MCSPDU                                                                                                                                                                          | Only <b>MAPData</b><br><br><b>MAPData</b> can only contain one of the following MCSPDUs:<br><b>MCSSendDataRequest</b><br><b>MCSSendDataIndication</b><br><b>MCSUniformSendDataIndication</b> |
+| Unreliable | Only <b>MAPData</b><br><br><b>MAPData</b> can only contain one of the following MCSPDUs:<br><b>MCSSendDataRequest</b><br><b>MCSSendDataIndication</b><br><b>MCSUniformSendDataRequest</b><br><b>MCSUniformSendDataIndication</b> | Only <b>MAPData</b><br><br><b>MAPData</b> can only contain one of the following MCSPDUs:<br><b>MCSSendDataRequest</b><br><b>MCSSendDataIndication</b><br><b>MCSUniformSendDataIndication</b> |
+
+## A.6 Use of MAP
+
+This subclause describes how MCS manages connections and data transfer when using the Multicast Adaptation Protocol (MAP). It is not the intention of this subclause to exhaustively describe the interactions between MCS and MAP. Rather, this subclause describes how MCS behaves differently than when using a unicast-only protocol stack (such as those currently defined in Recommendation T.123).
+
+To completely describe the differences in how MCS deals with MAP, it is useful to break T.125 into its four functional units: domain management; channel management; data transfer; and token management. Each of these units is described briefly below.
+
+### A.6.1 Domain management
+
+When making a connection to a remote MCS Provider using a unicast-only protocol stack, MCS creates one Transport Connection (TC) for each data transfer priority (the number of priorities is arbitrated as part of the domain parameters). Control MCSPDUs are always sent on the TC with the highest priority. Data MCSPDUs can be sent on all TCs (which one depends on priority).
+
+When making a connection to a remote MCS Provider using MAP, MCS creates only a single MAP Connection (MC), regardless of the number of data transfer priorities. Control MCSPDUs are sent on this MC. Data MCSPDUs are not actually sent on *any* MC, but are passed off to MAP as a whole (this is discussed in the subclause on Data Transfer).
+
+The Connect MCSPDUs perform the same role of initializing a new MCS connection, and arbitrating the domain parameters. **Connect-Initial** is sent by the calling MCS as the first MCSPDU over a new
+
+MC. **Connect-Response** is the first MCSPDU sent by the called MCS in reverse over a new MC. Since there is only one MC per MCS connection, there is no need for **Connect-Additional** and **Connect-Result**.
+
+For MAP to properly perform its routing duties, MCS must share some information regarding all newly-created connections. This includes: what domain the connection is bound to; whether it is an upward or downward connection; and what MCS protocol version will be used on the connection. Furthermore, when MCS binds the first MC to a domain, it must share with MAP how many priorities and reliability levels are to be used in the domain.
+
+All Domain MCSPDUs that deal with domain management are sent over an MC in exactly the same way they are sent over a TC when using a unicast protocol stack.
+
+### A.6.2 Channel management
+
+All Domain MCSPDUs that deal with channel management are sent over an MC in exactly the same way they are sent over a TC when using a unicast protocol stack.
+
+For MAP to be able to multicast data on behalf of MCS, it must know about channels (so that it knows where to send the data). MCS must share the following information with MAP:
+
+- 1) For each active channel, MAP must know which domain the channel is associated with, and what type of channel it is.
+- 2) For each active channel, MAP must know which MCs lead to joined users.
+- 3) For each active channel, MAP must know if MCS needs to receive the data. MCS will need the data if it must redirect it to a locally-attached user application or a different protocol stack.
+
+Static channels are considered active if there is at least one joined user application in the subtree of the local node. Dynamic channels are considered active as soon as they are allocated.
+
+### A.6.3 Data transfer
+
+The most significant difference in using MAP lies in the handling of data transfer. When using a unicast-only protocol stack, MCS assumes all responsibility for redirecting data to TCs that lead to interested users. When using MAP, much of this responsibility is delegated to MAP.
+
+MCS typically sends a given data MCSPDU to MAP only once, no matter how many nodes need to receive it. The only exception to this occurs if MCS has arbitrated a different protocol version for some of the MCs that are bound to the domain. MCS must send the data MCSPDU properly encoded for each active protocol version. MAP will see to it that everyone who needs the data will get it.
+
+When MCS receives data from MAP, there is no need for MCS to redirect the data back to MAP (unless there are multiple protocol versions in use, requiring MCS to perform version translation).
+
+When passing data to MAP, MCS uniquely identifies the target set of receivers by specifying a domain identifier, an MCS protocol version, and a data flow identifier. This is enough information since MAP already knows which MCs are bound to the domain, and which protocol version is in use on each. MAP can then use the data flow identifier to properly route the data via unicast and/or multicast. Note that the data flow identifier also communicates the relative priority of the data to MAP. This priority will always be 0 to  $N-1$ , with 0 being the highest priority ( $N$  is the number of priorities that MCS indicated are to be used in the domain). No priority translation between MCS and MAP is required.
+
+Consider Figure A.6-1, which shows a conference consisting of four nodes. Two of the three connections making up the conference are MCs. The third connection, binding Node 3 to Node 2, is a TC through the PSTN protocol stack defined in Recommendation T.123. It is useful to examine
+
+how the MCS at Node 2 reacts to data sourced from each of the four nodes. For this example, assume that non-uniform data is sent on a channel for which there are joined users at every node. Note that this example only discusses the handling of data at Node 2.
+
+- 1) When data originates on Node 1, it is received by MAP on Node 2. It is then passed to MCS who, in turn, sends the data to the TC that leads to Node 3. MCS will NOT send the data back to MAP.
+- 2) When data originates on Node 2, MCS sends the data to the TC that leads to Node 3. It also sends the data to MAP (once).
+- 3) When data originates on Node 3, it is passed to MCS on Node 2 by the PSTN protocol stack. MCS then passes the data to MAP (once).
+- 4) When data originates on Node 4, it is received by MAP on Node 2. It is then passed to MCS who, in turn, sends the data to the TC that leads to Node 3. MCS will NOT send the data back to MAP.
+
+![Diagram of a 4-way conference setup showing Node 1, Node 2, Node 3, and Node 4 with their interconnections.](3d1817e8551f9c226a5f561108d3b3f9_img.jpg)
+
+```
+
+graph TD
+    Node1[Node 1]
+    Node2[Node 2]
+    Node3[Node 3]
+    Node4[Node 4]
+    Node2 -- MC --> Node1
+    Node3 -- TC --> Node2
+    Node4 -- MC --> Node2
+  
+```
+
+The diagram illustrates a 4-way conference setup. It shows four nodes: Node 1 at the top, Node 2 in the middle, and Node 3 and Node 4 at the bottom. Node 2 is connected to Node 1 via a Multicast (MC) link. Node 2 is also connected to Node 3 via a Termination Control (TC) link. Node 2 is connected to Node 4 via an MC link. The diagram is labeled T1600700-97.
+
+Diagram of a 4-way conference setup showing Node 1, Node 2, Node 3, and Node 4 with their interconnections.
+
+**Figure A.6-1/T.125 – Sample 4-way conference**
+
+As this example illustrates, MCS trusts MAP to perform the routing for all MCs that are logically grouped (by domain and protocol version). This delegation is necessary, since only MAP knows when multicast is actually being used, and whether or not it is working. The abstraction presented to MCS is that multicast is *always* working.
+
+#### **A.6.3.1 Differing protocol versions**
+
+As mentioned above, it is necessary to differentiate data PDUs based on protocol version. This is simply because the format of the data PDUs is different. If half of the MCs in a domain are using one protocol version, while the other half are using a different one, then MCS must perform a translation on any data passing between the two groups. This requirement creates the only case where MCS may need to redirect data back to the same MAP protocol stack from which it came (after translation, of course).
+
+#### **A.6.3.2 Uniform data handling**
+
+Because of the global ordering requirement, it is necessary to treat uniform data a little differently than non-uniform data. MAP can determine whether a PDU is uniform or not by examining the data flow identifier.
+
+When MAP receives a uniform data PDU from MCS, it will check to see if there is an upward MC for the specified domain and protocol version. If so, MAP will send the PDU upward via unicast
+
+(since it must be a request). If there is no upward MC for the specified domain and protocol version, MAP will send the PDU downward to all joined recipients (via multicast, if possible).
+
+When MAP receives a uniform data PDU from a downward MC, it will check to see if there is an upward MC for the same domain and protocol version. If so, MAP will forward the PDU upward via unicast (the PDU will NOT be sent to MCS). If there is no upward MC for the same domain and protocol version, MAP will send the PDU to MCS.
+
+When MAP receives a uniform data PDU via multicast or from the upward MC, the PDU will be sent to MCS (if necessary), as well as being forwarded downward to those nodes not receiving data via multicast.
+
+#### **A.6.3.3 Request vs. indication**
+
+When sending non-uniform data via MAP, it is possible for the data to arrive at nodes both above AND below the current node. For this reason, it is necessary to specify whether MCS should identify such data PDUs as requests or indications.
+
+If the upward connection is an MC using the same MCS protocol version, then the PDU sent to MAP should be a request. Otherwise, it should be an indication. In other words, data that will ONLY flow downward is an indication, while data that flows upward is a request (even if it also flows downward).
+
+This creates the situation that it is possible for a node to receive a **Send-Data-Request** from a node that is hierarchically above it. MCS needs to recognize that this is not an error condition when the data comes from MAP, by treating the PDU as if it was properly oriented.
+
+Note that this situation does not exist for uniform data, since the requests are unicast upward first. Uniform data will only be multicast from the top, which guarantees that all receivers are getting an indication from a node that is hierarchically above them.
+
+#### **A.6.3.4 Proxy data**
+
+When sending non-uniform data, MAP can either multicast the data at the point-of-entry, or it can decide to use a multicast proxy. How the point-of-entry node makes this decision is beyond the scope of this Annex.
+
+Multicasting through a proxy simply means that the data is unicast upward until it reaches the Multicast Group Provider, who then multicasts it downward. This is similar to the handling of uniform data, except that the data do not have to go all the way up to the Top Provider before beginning its downward journey (it only has to go to the Multicast Group Provider). This technique can be used to reduce data flow state information in very large conferences. It can also be used to allow data to be multicast when the point-of-entry node cannot itself transmit via multicast.
+
+The use of proxy data is transparent to MCS. To MCS, it just looks like non-uniform data.
+
+### **A.6.4 Token management**
+
+All Domain MCSPDUs that deal with token management are sent over an MC in exactly the same way they are sent over a TC when using a unicast protocol stack.
+
+## **A.7 Use of transport protocols**
+
+This subclause describes the services that MAP expects to receive from the transport protocols.
+
+### A.7.1 Unicast transport protocols
+
+The services required from the unicast protocols are a subset of those defined in Recommendation X.214. MAP does not use exactly the same parameters described in Recommendation X.214, nor does it make use of expedited data. This subclause discusses the services that MAP *does* use.
+
+During connection establishment, MAP will create one or more unicast connections to the adjacent node. These connections are used to carry both control data and user data. If more than one connection is made, they are of varying priorities, allowing MAP to indicate to the transport protocol the relative importance of a given MAPPDU.
+
+For the reliable unicast protocols, MAP assumes that the service is error-free and ordered. Neither of these assumptions is made for the unreliable unicast protocols.
+
+MAP also assumes that all reliable unicast protocols are capable of segmenting MAPPDUs that are too large to transmit as a single unit. These MAPPDUs should be re-assembled on the receive side before they are sent to MAP. To prevent the need to handle arbitrarily large MAPPDUs, it is suggested that a limit of 16 384 bytes be placed on MAP. MAP must ensure that no MAPPDUs exceed this size.
+
+For reliable unicast, MAP assumes a "connection-oriented" service. This implies that both sides of the connection are aware of the other, and that some protocol was involved in the connection establishment process. This further implies that both nodes are maintaining state information about the connection between them, and can automatically sense packet loss and other network problems. When creating a reliable unicast connection, MAP participates by sending protocol of its own (after the transport protocol indicates that it is okay to do so).
+
+For unreliable unicast, MAP assumes a "connection-less" service. This simply means that MAP makes no assumptions about the service that is provided. It does not assume that data will be ordered. It does not assume that packet loss, or any other network problems, will be detected.
+
+The unicast primitives utilized by MAP are summarized in Table A.7-1.
+
+**Table A.7-1/T.125 – Unicast transport protocol service definition**
+
+| Primitive               | Parameters                                     | Reliable | Unreliable |
+|-------------------------|------------------------------------------------|----------|------------|
+| T-Connect request       | Called address,<br>priority<br>Calling address | X        |            |
+| T-Connect indication    |                                                | X        |            |
+| T-Connect response      |                                                | X        |            |
+| T-Connect confirm       |                                                | X        |            |
+| T-Data request          | User data                                      | X        |            |
+| T-Data indication       | User data                                      | X        |            |
+| T-Unit-Data request     | Destination address,<br>Priority, user data    |          | X          |
+| T-Unit-Data indication  | Source address,<br>User data                   |          | X          |
+| T-Disconnect request    | Reason                                         | X        |            |
+| T-Disconnect indication |                                                | X        |            |
+
+#### A.7.1.1 T-Connect
+
+The *T-Connect* primitives are used to create reliable unicast connections to remote nodes.
+
+The calling node will invoke *T-Connect request* to start the creation of a new connection. If the remote node can be found, a *T-Connect indication* is delivered to MAP on that node. MAP will ordinarily accept the connection by invoking *T-Connect response*. This in turn results in a *T-Connect confirm* at the calling node. Once this process is complete, the connection is ready and MAP will continue with its portion of connection establishment.
+
+##### Parameter definitions
+
+*Called Address*: This is the network address of the node to be called.
+
+*Calling Address*: This is the network address of the node placing the call.
+
+*Priority*: This field is used to specify the priority of this connection (relative to all other connections). The permissible range is 0 through 15, with 0 being the highest priority.
+
+#### A.7.1.2 T-Data
+
+The *T-Data* primitives are used to transfer MAPPDUs to the remote node via reliable unicast.
+
+When MAP wants to send a MAPDU via reliable unicast, it will invoke *T-Data request*. This will eventually cause a *T-Data indication* at the remote node.
+
+##### Parameter definition
+
+*User Data*: This is a variable length octet string. It is used to carry MAPPDUs.
+
+#### A.7.1.3 T-Unit-Data
+
+The *T-Unit-Data* primitives are used to transfer MAPPDUs to the remote node via unreliable unicast.
+
+When MAP wants to send a MAPDU via unreliable unicast, it will invoke *T-Unit-Data request*. This will eventually cause zero or more *T-Unit-Data indications* at the remote node. The order of the requests may not match the order of the indications. Furthermore, there may not be a one-to-one correspondence between requests and indications (some requests may never result in an indication, while other requests may result in multiple indications).
+
+##### Parameter definitions
+
+*Destination Address*: This is the network address of the node that is to receive the data.
+
+*Source Address*: This is the network address of the node that originated the data.
+
+*Priority*: This field is used to specify the priority of this MAPDU (relative to all other MAPPDUs). The permissible range is 0 through 15, with 0 being the highest priority.
+
+*User Data*: This is a variable length octet string. It is used to carry MAPPDUs.
+
+#### A.7.1.4 T-Disconnect
+
+The *T-Disconnect* primitives are used to shut down existing reliable unicast connections.
+
+One side will typically invoke *T-Disconnect request*, which breaks the connection and causes the other side to receive a *T-Disconnect indication*. However, if the connection is dropped because of network problems, both sides will receive a *T-Disconnect indication*.
+
+##### Parameter definition
+
+*Reason*: This contains the reason why a connection was dropped. This is one of: user initiated; provider initiated; or unspecified failure.
+
+### A.7.2 Multicast transport protocols
+
+This subclause describes the services required by MAP to perform multicast group management. This includes joining a multicast group prior to data flow, transmission and reception of data via multicast, and leaving a group when multicast services are no longer required.
+
+All data flow in a multicast island is initially unicast. In response to the flow of data, MAP will allocate and distribute multicast group addresses, to be used in optimizing network traffic. At each node in the island, MAP will decide if it is necessary for that node to join an assigned group. If it is, it will call upon the multicast protocols to perform this service.
+
+When MAP decides to join a multicast group, it can specify one of three modes: transmit-only; receive-only; or transmit/receive. Some multicast protocols may be able to optimize their behavior by knowing which combination is required, so this information is passed to them during a group join operation.
+
+For reliable multicast, MAP assumes the service is error-free, possibly after an indeterminate loss of the initial data from each transmitter. This assumption is not made for unreliable multicast.
+
+MAP never assumes that multicast data will be ordered. For reliable multicast, however, MAP does assume that all gaps caused by out-of-order data will be filled. If a new node begins transmitting to a multicast group, the reliable multicast protocol should *not* begin forwarding that data to MAP until reception from that node has stabilized (i.e. all gaps in reception will be filled). This means that the received data stream may begin after different initial losses at different receivers.
+
+It is not necessary for the multicast protocols to support segmentation. This is because **MAPData** is the only MAPDU ever sent via multicast, and it will be segmented to the proper size by MAP before being sent to the multicast protocol.
+
+The multicast primitives utilized by MAP are summarized in Table A.7-2.
+
+**Table A.7-2/T.125 – Multicast transport protocol service definition**
+
+| Primitive                               | Parameters                                     |
+|-----------------------------------------|------------------------------------------------|
+| MT-Join request<br>MT-Join confirm      | Multicast group address, priority, tx/rx flags |
+| MT-Data request<br>MT-Data indication   | User data                                      |
+| MT-Leave request<br>MT-Leave indication | Reason                                         |
+
+#### A.7.2.1 MT-Join
+
+The *MT-Join* primitives are used to join a multicast group.
+
+There are flags in the *MT-Join request* that allow MAP to specify whether it intends to transmit, receive, or both. The state of these flags can be changed by issuing additional *MT-Join requests*, with no need to invoke *MT-Leave request*.
+
+The *MT-Join confirm* tells MAP whether or not the pending *MT-Join request* was successful.
+
+##### Parameter definitions
+
+*Multicast Group Address*: This is the address of the multicast group to be joined. A NULL value indicates that the transport protocol should create a new group, and return the address to MAP for distribution.
+
+*Priority*: This field is used to specify the priority of this group (relative to all other groups). The permissible range is 0 through 15, with 0 being the highest priority.
+
+*TX/RX Flags*: These flags allow MAP to tell the multicast protocol which of three modes it requires: transmit-only; receive-only; or transmit/receive.
+
+#### A.7.2.2 MT-Data
+
+The *MT-Data* primitives are used to transfer MAPPDUs to all nodes in the group via multicast.
+
+These primitives work the same way for both reliable and unreliable protocols. When MAP wants to send a MAPPDU via multicast, it will invoke *MT-Data request*. This will eventually cause a *MT-Data indication* at all remote nodes that need to receive the data. The order of the requests may not match the order of the indications. For unreliable multicast, there may not be a one-to-one correspondence between requests and indications (some requests may never result in an indication, while other requests may result in multiple indications).
+
+##### Parameter definition
+
+*User Data*: This is a variable length octet string. It is used to carry MAPPDUs.
+
+#### A.7.2.3 MT-Leave
+
+The *MT-Leave* primitives are used to leave a multicast group. *MT-Leave indication* is used to tell MAP that its membership in the group was prematurely terminated.
+
+When MAP decides that it no longer needs to transmit *or* receive data on a given multicast group, it will invoke *MT-Leave request*. The multicast protocol should immediately stop forwarding data from the group to MAP. There is no confirm for this primitive.
+
+*MT-Leave indication* only occurs if the multicast protocol needs to tell MAP that it is no longer joined (even though MAP did not request a leave). This indication is *not* caused by other nodes leaving a group.
+
+##### Parameter definition
+
+*Reason*: This contains the reason why the multicast group was left. This is one of: provider initiated; or unspecified failure.
+
+### A.7.3 Local information
+
+For MAP to handle many transport protocols simultaneously, with no prior knowledge of their capabilities, there will have to be local configuration information. Each transport protocol is described to MAP in a generic fashion. This information is used by MAP during the transport protocol arbitration process, and includes the following parameters:
+
+- *Transport Protocol ID*: This is used to uniquely identify the transport protocol during the protocol arbitration process.
+- *Transport Protocol Type*: Each transport protocol must be identified as one of the following: reliable unicast; unreliable unicast; reliable multicast; or unreliable multicast.
+- *Preference Weighting*: This relative weighting is used to determine which transport protocols are preferred over others.
+- *Maximum Number of Connections*: This is only relevant for unicast protocols. This is the maximum number of connections that the unicast protocol recommends *per MAP connection*.
+- *Maximum Payload Size*: This is the maximum payload size that the transport protocol can handle. Note that for reliable unicast, the transport protocol *must* be able to handle up to
+
+16 384 bytes (with segmentation, if necessary), so this is just a recommended maximum size.
+
+- *Configuration Data:* When MAP is ready to arbitrate protocols with a remote node, it gets a block of configuration data from each candidate protocol (which can be NULL). This information is passed to the remote node during protocol arbitration, where it is passed to the equivalent protocol on that node (if it exists). MAP on the called node then gets the configuration data to be returned from its local stack, in order to complete the protocol arbitration process. This configuration data should be separately retrieved for each MAP connection that is arbitrated.
+
+The information contained in the configuration data block is separately defined for each transport protocol. The format of these blocks can either be standardized (along with transport protocol profiles), or can be proprietary. An example of how it might be used would be to communicate a dynamic IP port number back to the caller.
+
+## A.8 Protocol specification
+
+This subclause contains a step-by-step description of how MAP works, which includes several PDU timing diagrams. Figure A.8-1 illustrates the domain hierarchy that was used to generate these diagrams.
+
+![Figure A.8-1/T.125: Sample domain hierarchy diagram. It shows a hierarchical structure with four nodes. Node 1 is at the top. Node 2 is below Node 1, connected by a vertical line with an arrow pointing up to Node 1. Node 3 and Node 4 are at the bottom, connected to Node 2 by lines that merge into a single vertical line with an arrow pointing up to Node 2. The diagram is labeled T1600710-97 at the bottom right.](57134800ac3a97b6212b27b93aa196ac_img.jpg)
+
+```
+graph BT; Node3[Node 3] --- Node2[Node 2]; Node4[Node 4] --- Node2; Node2 --> Node1[Node 1];
+```
+
+T1600710-97
+
+Figure A.8-1/T.125: Sample domain hierarchy diagram. It shows a hierarchical structure with four nodes. Node 1 is at the top. Node 2 is below Node 1, connected by a vertical line with an arrow pointing up to Node 1. Node 3 and Node 4 are at the bottom, connected to Node 2 by lines that merge into a single vertical line with an arrow pointing up to Node 2. The diagram is labeled T1600710-97 at the bottom right.
+
+**Figure A.8-1/T.125 – Sample domain referenced by subsequent examples**
+
+### A.8.1 Establishing the initial reliable unicast connection
+
+During processing of an MCS Connect Request, the first thing that must be done is the creation of a reliable unicast connection. The connection is made using the protocol specified by MCS, or the default protocol for the network (if no protocol is specified). This connection is used to transmit all control PDUs (both MCS and MAP). The first MAPDU sent across the new connection by the calling node is **MAPConnectRequest**. This MAPDU contains the following fields:
+
+- A protocol version number identifying which version of MAP the calling node wishes to use.
+- A MAP Service Access Point (MAPSAP) identifying who on the called node should accept the call (this is specified by MCS as part of the network address).
+- A Domain Reference ID that can bind this connection to a particular domain (for the initial connection this field is set to zero).
+
+- Low and high priority values that indicate the range of priorities to be sent on this connection (for the initial connection these fields will both be set to zero).
+
+If the called node wishes to accept the call, it will transmit a **MAPConnectConfirm** back to the calling node. This MAP PDU contains the following fields:
+
+- A protocol version number identifying which version of MAP *will* be used (this must be less than or equal to the value specified by the caller).
+- The MAPSAP on the called node that actually accepted the incoming connection.
+
+If the called node does not wish to accept the incoming call, it will transmit a **MAPDisconnectRequest** back to the calling node. This MAP PDU contains the reason for the rejection. It also contains a field indicating that no confirm is required, so the connection is dropped immediately.
+
+Figure A.8-2 contains a timing diagram that shows a successful call set-up.
+
+![Timing diagram showing a successful call set-up between Node 1 and Node 2. Node 1 sends a MAPConnectRequest to Node 2, and Node 2 responds with a MAPConnectConfirm to Node 1. The diagram includes vertical lines for each node and arrows indicating the direction of the PDUs. A reference number T1602530-97 is at the bottom right.](ef0faba51289e3a364ba51e5ef4d1a43_img.jpg)
+
+```
+
+sequenceDiagram
+    participant N1 as Node 1
+    participant N2 as Node 2
+    N1->>N2: MAPConnectRequest
+    N2-->>N1: MAPConnectConfirm
+  
+```
+
+T1602530-97
+
+Timing diagram showing a successful call set-up between Node 1 and Node 2. Node 1 sends a MAPConnectRequest to Node 2, and Node 2 responds with a MAPConnectConfirm to Node 1. The diagram includes vertical lines for each node and arrows indicating the direction of the PDUs. A reference number T1602530-97 is at the bottom right.
+
+**Figure A.8-2/T.125 – Timing of the connect MAP PDUs**
+
+### A.8.2 Arbitrating transport protocols
+
+Once the initial reliable unicast connection is established, MCS will proceed with its connection set-up. When MCS has completed its set-up, it will pass the following information to MAP: what domain the connection is bound to; what protocol version MCS will be using on the connection; and how many priorities and reliability levels will be used in the domain (this is provided to MAP when the domain parameters are first locked). Once MAP has this information, it can proceed with the process of transport protocol arbitration.
+
+The calling node will issue a **MAPArbitrateProtocolsRequest** that contains a list of the transport protocols that it is willing to use (both unicast and multicast). As a minimum, this list will include the reliable unicast protocol used to create the existing connection. Support for other transport protocols is optional. After comparing this list to its own capabilities, the called node will respond with a **MAPArbitrateProtocolsConfirm** that indicates which protocols are to be used.
+
+If no unreliable protocols are selected, then unreliable data is sent using the reliable protocols (for unicast, unreliable data is sent through the same connections as reliable data). If MCS has indicated that there will be no unreliable data in the domain, then it is unnecessary to include unreliable protocols in either of the arbitration MAP PDUs. If no multicast protocols are selected, then all data is sent via unicast (between these two nodes).
+
+The confirm will always include exactly one reliable unicast protocol. It will optionally include one unreliable unicast protocol. For multicast, it will include all protocols that both nodes have agreed can be used (there can be more than one for each reliability level).
+
+For the reliable unicast protocol, the nodes also arbitrate the number of transport connections that will make up this one MAP connection. If there is more than one transport connection, then unicast data is split between them according to priority. It is perfectly okay for different MAP connections to
+
+be made up of differing numbers of transport connections, even in the same multicast island. The process of creating additional transport connections is detailed in the next subclauses.
+
+The arbitration MAPPDUs also contain a Domain Reference ID. This value is later used by the sender to indicate which domain a MAPPDU is associated with, in the case that the domain cannot be implicitly inferred. Specifically, this value is used when creating additional reliable unicast connections, and when transmitting unreliable data.
+
+Any node can force a re-arbitration of transport protocols with a neighboring node simply by issuing a **MAPArbitrateProtocolsRequest**. To ensure that no connections are lost, however, it is required that the previously selected reliable unicast protocol be available in the protocol menu. If the re-arbitration results in a change to the unicast protocols, it is necessary to make the transition immediately (this process is detailed in a later subclause). Changes to the set of multicast protocols have no direct effect on existing multicast groups. These changes are reflected only in subsequent group allocations (this process is detailed in the subclause on allocating and distributing multicast groups, see A.8.3).
+
+It is possible for adjacent nodes to encounter an "arbitration collision". This occurs when both nodes issue a **MAPArbitrateProtocolsRequest** at the same time. This situation is detectable at both nodes because they will both receive an arbitration request when they were expecting a confirm. When this occurs, the request from the downward node is ignored (and the downward node stops waiting for a confirm). The request from the upward node is processed normally.
+
+Figure A.8-3 illustrates the arbitration process when Node 2 calls Node 1.
+
+![Sequence diagram showing the timing of arbitration MAPPDUs between Node 1 and Node 2. Node 2 sends a MAPArbitrateProtocolsRequest to Node 1, and Node 1 sends a MapArbitrateProtocolsConfirm to Node 2. The diagram includes a reference to T1600730-97.](0bbbad069459da54c1cdef84c90b316a_img.jpg)
+
+```
+sequenceDiagram
+    participant N1 as Node 1
+    participant N2 as Node 2
+    N2->>N1: MAPArbitrateProtocolsRequest
+    N1-->>N2: MapArbitrateProtocolsConfirm
+```
+
+T1600730-97
+
+Sequence diagram showing the timing of arbitration MAPPDUs between Node 1 and Node 2. Node 2 sends a MAPArbitrateProtocolsRequest to Node 1, and Node 1 sends a MapArbitrateProtocolsConfirm to Node 2. The diagram includes a reference to T1600730-97.
+
+**Figure A.8-3/T.125 – Timing of the arbitration MAPPDUs**
+
+#### A.8.2.1 Creating additional reliable unicast connections
+
+As mentioned above, nodes also arbitrate the number of reliable unicast connections that will make up a single MAP connection. If they decide to use more than one, then it is necessary to create the additional connections. This subclause uses the term *connection* to refer to a reliable unicast connection.
+
+This process is initiated by the calling node, who calls upon the selected reliable unicast protocol to create the appropriate number of additional connections. As each connection becomes ready for use, the calling node will issue a **MAPConnectRequest** over it. This MAPPDU will contain the following fields:
+
+- The protocol version number is the same one already selected for the initial connection.
+- The MAPSAP is the same one used to create the initial connection.
+- The Domain Reference ID is the one that was sent in the **MAPArbitrateProtocolsRequest** on the initial connection.
+- The low and high priority values will indicate the range of priorities that will be sent over this connection (the required priorities, as specified by MCS, are typically spread out evenly over the number of connections).
+
+The called node should accept each of the additional connections by issuing a **MAPConnectConfirm** over each one. This MAPDU will contain an exact copy of the first two fields of the request above.
+
+It is a protocol error to refuse one of the additional connections. If one of the two nodes cannot create the agreed upon number of connections, then *all* connections corresponding to this MAP connection must be shut down, severing the lower node from the domain.
+
+It is important that all required priorities be mapped to a connection when this process completes. As each additional connection is brought up, it is mapped to a range of priorities. All required priorities that are not explicitly mapped to an additional connection are handled by the initial connection. These leftover priorities *must* be contiguous with priority zero (which is already mapped to the initial connection).
+
+#### A.8.2.2 Changing reliable unicast connections
+
+After a protocol re-arbitration has occurred, it may be necessary for two nodes to dynamically switch to a different set of reliable unicast connections. This will occur if any of the following conditions exist: the nodes have chosen to switch to a different reliable unicast protocol; the nodes have chosen to use a different number of transport connections; the nodes have elected to change the maximum payload size of the reliable unicast connections (this cannot be done while multicast groups are still active); or the nodes have exchanged new configuration data for the reliable unicast protocol. Note that a dynamic transition cannot occur until the set-up of the previous set of reliable unicast connections is complete.
+
+To dynamically transition to a different set of connections, it is necessary to perform the following steps:
+
+- 1) The initiator of the arbitration must create the agreed upon number of new connections to the remote node using the selected protocol. This node will now be referred to as the "calling node".
+- 2) The calling node will issue a **MAPConnectRequest** on each new connection as it becomes ready. This MAPDU will contain the following fields:
+  - The protocol version number is the same one already selected for the previous connections.
+  - The MAPSAP is the same one used to create the previous connections.
+  - The Domain Reference ID is the one that was sent in the **MAPArbitrateProtocolsRequest** on the previous initial connection.
+  - The low and high priority values will indicate the range of priorities that will be sent over this connection (the required priorities, as specified by MCS, are typically spread out evenly over the number of connections).
+- 3) The called node will respond by sending a **MAPConnectConfirm** on each new connection when the request is received. The protocol version number and the MAPSAP is set the same as in the request.
+- 4) As each confirm is received, the calling node will keep track of which new connections are ready for use. By comparing the priority range of the previous connections with the priority range of the confirmed new connections, the calling node can determine when a previous connection can be shut down (because all of its priorities are covered by new connections). When this occurs, the calling node will issue a **MAPDisconnectRequest** to the previous connection. At this point, the calling node will begin sending all reliable unicast traffic in the priority range of the previous connection on the appropriate new connection(s).
+
+- 5) Upon receiving a disconnect request, the called node will issue a **MAPDisconnectConfirm** on the previous connection. At this point, the called node will begin sending all reliable unicast traffic in the priority range of the previous connection on the appropriate new connection(s). The called node must also keep track of which previous connections have been disconnected. By comparing the priority range of the new connections with the priority range of the previous connections, the called node can determine when it is safe to begin processing data received from a new connection (this occurs when all previous connections that carried data in the priority range of the new connection have been disconnected).
+- 6) When the calling node receives a disconnect confirm, it can be assumed that all pending data on the previous connection has been flushed, and that connection can be shut down. By comparing the priority range of the new connections with the priority range of the previous connections, the calling node can determine when it is safe to begin processing data received from a new connection (this occurs when all previous connections that carried data in the priority range of the new connection have been disconnected).
+
+### A.8.3 Allocating and distributing multicast groups
+
+Once a set of transport protocols have been arbitrated, MAP can begin allocating and distributing multicast group addresses. In order to minimize the number of active multicast groups, MAP should not assign a multicast group address to a metachannel until data traffic is detected that could use the group. No data will be lost, since all data is initially transmitted via unicast.
+
+When MAP detects data flow for which there is no multicast group, a multicast group address may be assigned. This process begins at each node in the domain that either has no upward MAP connection, or has an upward MAP connection but no common multicast protocols with the node above. These nodes become Multicast Group Providers. They will examine the lists of multicast protocols supported by the nodes below them, and attempt to choose the protocol(s) that will result in the fewest number of multicast islands. Ideally, it will be possible to select a single protocol that is supported by *all* downward nodes (allowing everyone below to be in the same multicast island).
+
+Once a multicast protocol is selected for each downward node, MAP will obtain a multicast group address for each different protocol to be used. Depending on a local set of policies, the group address to be assigned may already be in use for another metachannel, or it may be newly allocated. How this allocation is performed is outside the scope of this protocol. Once a multicast group address is decided upon, it is propagated downward using **MAPAddGroupRequest**.
+
+**MAPAddGroupRequest** tells the recipient what channel, reliability level, and priority range the assignment corresponds to. It also tells the recipient which multicast protocol and group address to use. As described in a previous subclause, the act of selecting multicast protocols for the downward nodes results in the definition of multicast island boundaries. All nodes that are told to use the same multicast protocol and group address are, by definition, in the same multicast island.
+
+When a node receives a **MAPAddGroupRequest**, it will add the group to its list of active multicast groups. If it has any downward MAP connections, then it must select a multicast protocol for each downward node. If possible, it should use the same protocol that was selected for it by the node above. If this is not possible for some downward nodes, then it should try to select protocols that will result in the fewest, largest multicast islands. Once the selections are made, the node will obtain a multicast group address for each different protocol to be used, and propagate the information downward using **MAPAddGroupRequest**.
+
+The process of propagating multicast group information downward is depicted in Figure A.8-4.
+
+![Sequence diagram showing the timing of the add group procedure across four nodes. Node 1 sends MAPAddGroupRequest to Node 2. Node 2 sends MAPAddGroupRequest to Node 3. Node 3 sends MAPAddGroupRequest to Node 4. The diagram is labeled T1600740-97.](95be50ec094942200786128aa936cfae_img.jpg)
+
+```
+
+sequenceDiagram
+    participant N1 as Node 1
+    participant N2 as Node 2
+    participant N3 as Node 3
+    participant N4 as Node 4
+    N1->>N2: MAPAddGroupRequest
+    N2->>N3: MAPAddGroupRequest
+    N3->>N4: MAPAddGroupRequest
+    
+```
+
+T1600740-97
+
+Sequence diagram showing the timing of the add group procedure across four nodes. Node 1 sends MAPAddGroupRequest to Node 2. Node 2 sends MAPAddGroupRequest to Node 3. Node 3 sends MAPAddGroupRequest to Node 4. The diagram is labeled T1600740-97.
+
+**Figure A.8-4/T.125 – Timing of the add group procedure**
+
+### A.8.4 Managing multicast data traffic (self-tuning)
+
+Once a multicast group address has been distributed, the nodes in the multicast island can begin to use it. It is not acceptable, however, for the nodes to assume that multicast is working immediately. There are many things that can cause multicast to fail. First of all, not all networks support multicast. This can result in multicast data not reaching one or more nodes in the multicast island. Even if the network does support multicast, other factors, such as Time-To-Live (TTL), can cause multicast data to fall short of its destination.
+
+For these reasons, among others, MAP employs a self-tuning strategy that allows it to depend on multicast only when multicast is working. This strategy works by sending all data via both unicast AND multicast, and then dynamically turning off unicast on those connections that lead to nodes who are successfully receiving the data via multicast.
+
+Unicast data within a multicast island is controlled independently for each "data flow". A data flow is uniquely identified by the following five fields: sender ID; channel ID; reliability level; priority; and data type. By default, all data are sent via unicast to all nodes in the multicast island that need to receive it. The data are also sent to the multicast group by a single node in the multicast island (the multicast sender). When a node detects that it is receiving a given data flow via multicast, it will send a **MAPDisableUnicastRequest** to its neighboring node in the direction of the multicast sender. This will cause the neighboring node to stop forwarding that data flow via unicast.
+
+The identity of the multicast sender for a given data flow is determined by the data type, as follows:
+
+- For non-uniform data, the multicast sender is simply the data flow's original point-of-entry node.
+- For uniform data, all data are unicast upward to the Top Provider before being eligible for multicast. The data are sent to the multicast group by the Multicast Group Provider on its way back down (the multicast sender is *always* the Multicast Group Provider). When sending a **MAPDisableUnicastRequest** for uniform data, it is always sent upward. Furthermore, sender ID shall be ignored when uniquely identifying uniform data flows.
+- For proxy data, all data are unicast upward to the Multicast Group Provider. The Multicast Group Provider will forward the data upward via unicast (if necessary), while simultaneously sending the data back downward (via both unicast and multicast). As with uniform data, the multicast sender is *always* the Multicast Group Provider. When sending a **MAPDisableUnicastRequest** for proxy data, it is always sent upward. Furthermore, sender ID shall be ignored when uniquely identifying proxy data flows.
+
+The proxy data type provides an alternative way of sending non-uniform data. Proxy data **cannot** be used to transmit uniform data. Using proxy data reduces the amount of data flow state information, since all proxy data senders for a given channel ID/reliability level/priority are merged into one data flow. Proxy data is also useful on networks that do not allow nodes to originate multicast information. Knowing when to use proxy data is a local implementation issue. However, once a node
+
+begins sending proxy data for a given sender ID/channel ID/reliability level/priority, it cannot later decide to use the non-uniform data type (the reverse is also true). The decision to use proxy data is strictly local, and different nodes may handle local senders differently.
+
+There is one other important consideration when using proxy data. Each node on the path from the originator to the Multicast Group Provider will see the data twice (once on its way up, and again on its way back down). These nodes should only send the data to MCS once. It does not matter whether this is done as the data flows up, or as it comes back down (but it should be done consistently). Furthermore, the originating node should *never* forward the data back to the user attachment that sent it.
+
+Before a node tells its neighbor to disable unicast for a data flow, it must be certain that it can transition to multicast with no data loss. To ensure this, it must receive at least one data packet via unicast, so that it knows what the next sequence number should be (note that sequence numbers are unique to each data flow, and are assigned by the originator of the data flow). Either before or after receiving this unicast packet, the node must receive a data packet via multicast with a sequence number that is less than or equal to the next expected sequence number. This indicates an overlap in the two data streams, allowing unicast to be disabled.
+
+When data is first transmitted on a new data flow, it is sent via unicast AND multicast throughout the island. Overtime unicast is disabled wherever possible, resulting in optimal network traffic.
+
+Figure A.8-5 shows an example of this self-tuning strategy (refer back to Figure A.8-1 for domain hierarchy). This example tracks the transmission of three data packets from a previously unknown data flow, as follows:
+
+- 1) A user application attached to Node 1 transmits a data packet. Node 1 transmits the data to the multicast group. It also transmits the data to Node 2 via unicast, since Node 2 has not yet disabled unicast for this data flow. Node 4 has not yet finished joining the group, so the multicast data packet only arrives at Nodes 2 and 3. Nodes 2 and 3 will hold the data since they do not yet know what sequence number is valid. When Node 2 receives the data via unicast, it redirects the data to Nodes 3 and 4 (via unicast). Nodes 2 and 3 now recognize that the multicast packet is the same as the unicast packet, so they each issue a **MAPDisableUnicastRequest** in the direction of the sender.
+- 2) The user application at Node 1 transmits another data packet on the same data flow. As before, Node 1 transmits the data to the multicast group. This time Node 1 does *not* transmit the packet to Node 2 via unicast, since Node 2 has already disabled unicast for this data flow. This time the multicast transmission arrives at all three downstream nodes (including Node 4). Node 2 transmits the data via unicast to Node 4, but not to Node 3 (since Node 3 has disabled unicast for this data flow). Node 4 now knows that it is synchronized to the multicast data stream, so it issues a **MAPDisableUnicastRequest** upward.
+- 3) The user application at Node 1 transmits a third data packet on the same data flow. As before, Node 1 transmits the data to the multicast group. This time, however, no one will unicast the data, since all nodes in the island have disabled unicast for this data flow.
+
+![Sequence diagram showing the timing of the disable unicast procedure for a given data flow across four nodes (Node 1, Node 2, Node 3, Node 4). The diagram illustrates the flow of MAPData (1), MAPData (2), and MAPData (3) via unicast and multicast, and the subsequent MAPDisableUnicastRequest messages sent from nodes that received multicast data back to the source node (Node 1).](ea40403ee09ad7bcb209382495f36547_img.jpg)
+
+The diagram illustrates the timing of the disable unicast procedure across four nodes (Node 1, Node 2, Node 3, Node 4). The legend indicates that solid lines with an 'X' at the end represent Unicast, and dashed lines with an 'X' at the end represent Multicast.
+
+- MAPData (1):** Node 1 sends MAPData (1) via unicast to Node 2 and via multicast to Node 3 and Node 4. Node 2 then sends MAPData (1) via unicast to Node 3. Node 4 sends MAPDisableUnicastRequest via unicast to Node 2, which then forwards it via unicast to Node 1.
+- MAPData (2):** Node 1 sends MAPData (2) via unicast to Node 2 and via multicast to Node 3 and Node 4. Node 2 sends MAPData (2) via unicast to Node 3. Node 4 sends MAPDisableUnicastRequest via unicast to Node 3, which then forwards it via unicast to Node 2, and finally via unicast to Node 1.
+- MAPData (3):** Node 1 sends MAPData (3) via unicast to Node 2 and via multicast to Node 3 and Node 4. Node 2 sends MAPData (3) via unicast to Node 3. Node 4 sends MAPDisableUnicastRequest via unicast to Node 3, which then forwards it via unicast to Node 2, and finally via unicast to Node 1.
+
+T1600750-97
+
+Sequence diagram showing the timing of the disable unicast procedure for a given data flow across four nodes (Node 1, Node 2, Node 3, Node 4). The diagram illustrates the flow of MAPData (1), MAPData (2), and MAPData (3) via unicast and multicast, and the subsequent MAPDisableUnicastRequest messages sent from nodes that received multicast data back to the source node (Node 1).
+
+**Figure A.8-5/T.125 – Example timing of the disable unicast procedure for a given data flow**
+
+### A.8.5 Giving up on multicast
+
+The previous subclause focused on what happens when multicast is working. This subclause discusses what a node can do to optimize its transmissions in the case that multicast does not seem to be working.
+
+When a node first begins transmitting data for a non-uniform data flow, it will do so via both unicast and multicast. If the adjacent nodes receive the multicast data, they will disable the unicast transmissions as described in the previous subclause. If the adjacent nodes do not receive the data via multicast, this disabling of unicast will never occur. This could leave the sending node in the position of transmitting every data PDU more times than necessary (once for each adjacent node, plus once for multicast). This problem is most pronounced on a leaf node, who could end up using twice the required bandwidth. This may be unacceptable (especially if the node is attached using a low-speed connection). Unfortunately, the node cannot simply stop transmitting data via multicast. It is possible that a node somewhere in the island (not adjacent) is receiving the multicast data, and may have already disabled unicast.
+
+Each **MAPData** PDU contains a flag that can be used by a node to resolve this problem. This flag is called the Unicast Forward Flag. This flag forces all intermediate nodes in the multicast island to once again forward the data flow via unicast to all receivers (even if they have previously disabled unicast). When a node decides that it wants to stop sending a given data flow via multicast, it simply sends all future **MAPData** PDUs (for that data flow) via unicast only, with the Unicast Forward Flag set. This makes it safe for the node to stop transmitting via multicast.
+
+### A.8.6 Removing multicast groups
+
+When a Multicast Group Provider senses that a multicast group is no longer needed, that group can be removed from the island. For reliable data, it is very important that the group be removed in a manner that guarantees no loss of data.
+
+To ensure this, the Multicast Group Provider will first disable multicast reception for the group. This is done by sending a **MAPDisableMulticastRequest** downward to all nodes in the island (this request is automatically forwarded by each receiving node to those nodes that lie below them). This MAPPDU causes each node to begin the process of re-enabling unicast for all data flows on the group for which unicast was previously disabled. This is done by issuing a **MAPEnableUnicastRequest** in the direction of the sender for each affected data flow. This MAPPDU also causes the group to be marked as disabled, which prohibits any further disabling of unicast for the group. Note that this does NOT cause the nodes to stop transmitting data to the multicast group. Furthermore, the nodes must stay joined as receivers to the multicast group at least until unicast has been successfully enabled for all affected data flows.
+
+When the **MAPDisableMulticastRequest** reaches the bottom nodes in the multicast island, they can respond with a **MAPDisableMulticastConfirm**. Before doing this, they must ensure that all data flows for which unicast was previously disabled on the group are completely re-enabled. To ensure this, each node must have received a **MAPEnableUnicastConfirm** for each outstanding request. Furthermore, each node must examine the sequence number in the confirm to ensure that all in-flight multicast data has been received (if not, it must wait for it to arrive). Once this is done, the **MAPDisableMulticastConfirm** is sent to the node above.
+
+Intermediate nodes in the island must wait until they have received **MAPDisableMulticastConfirm** PDUs from all nodes below them in the island. They must also wait until all previously disabled unicast data flows are re-enabled, as described above. Then they can issue a **MAPDisableMulticastConfirm** to the node above.
+
+Once the Multicast Group Provider has received **MAPDisableMulticastConfirm** PDUs from all downward nodes, and ensured that its unicast data flows are re-enabled, it is known that the group is no longer in use. At this point, the Multicast Group Provider can issue a **MAPRemoveGroupRequest** downward. This MAPPDU will propagate to all nodes in the island, causing each node to leave the group (if it is joined), and remove it from their list of active groups.
+
+Figure A.8-6 illustrates the process of group removal for the sample domain shown in Figure A.8-1. This is a continuation of the example in Figure A.8-5, in which unicast has been disabled for a single sender attached to Node 1.
+
+![Sequence diagram showing the timing of the group removal procedure between four nodes (Node 1, Node 2, Node 3, Node 4). The diagram illustrates the flow of MAPDisableMulticastRequest, MAPDisableMulticastConfirm, MAPEnableUnicastRequest, MAPEnableUnicastConfirm, and MAPRemoveGroupRequest messages across the nodes.](49d7bfbc65a92a7e1bd61777326a212d_img.jpg)
+
+```
+
+sequenceDiagram
+    participant N1 as Node 1
+    participant N2 as Node 2
+    participant N3 as Node 3
+    participant N4 as Node 4
+
+    N1->>N2: MAPDisableMulticastRequest
+    N2->>N3: MAPDisableMulticastRequest
+    N2->>N4: MAPDisableMulticastRequest
+    N1->>N2: MAPEnableUnicastRequest
+    N2->>N3: MAPEnableUnicastRequest
+    N2->>N4: MAPEnableUnicastRequest
+    N1->>N2: MAPEnableUnicastConfirm
+    N2->>N3: MAPEnableUnicastConfirm
+    N2->>N4: MAPEnableUnicastConfirm
+    N1->>N2: MAPDisableMulticastConfirm
+    N2->>N3: MAPDisableMulticastConfirm
+    N2->>N4: MAPDisableMulticastConfirm
+    N1->>N2: MAPRemoveGroupRequest
+    N2->>N3: MAPRemoveGroupRequest
+    N2->>N4: MAPRemoveGroupRequest
+  
+```
+
+T1600760-97
+
+Sequence diagram showing the timing of the group removal procedure between four nodes (Node 1, Node 2, Node 3, Node 4). The diagram illustrates the flow of MAPDisableMulticastRequest, MAPDisableMulticastConfirm, MAPEnableUnicastRequest, MAPEnableUnicastConfirm, and MAPRemoveGroupRequest messages across the nodes.
+
+**Figure A.8-6/T.125 – Timing of the group removal procedure**
+
+## A.9 MAPPDU descriptions
+
+This subclause describes the PDUs that are used by MAP. Each MAPPDU begins with a brief description of what it is used for. This is followed by a table showing the fields that are encoded into the MAPPDU. Finally, there is a description of what each field in the MAPPDU is.
+
+Note that the next subclause contains the ASN.1 definition of each MAPPDU.
+
+### A.9.1 MAPConnectRequest
+
+When creating a new connection between two nodes for a given domain, the first step is to open a reliable unicast connection. **MAPConnectRequest** is the first MAPPDU sent across that connection. The calling node sends this MAPPDU to tell the called node what protocol version it wishes to use. This is just a suggested value. It is up to the called node to make the final decision and communicate it back to the calling node by sending a **MAPConnectConfirm**.
+
+This MAPPDU includes a MAP Service Access Point (MAPSAP) field which allows the calling node to specify who on the called node should receive the incoming call.
+
+This MAPPDU also contains a Domain Reference ID, which allows the calling node to associate this connection with a particular domain. This is used when transport protocol arbitration results in the creation of additional connections, or the transition to a different set of connections.
+
+The following table summarizes the **MAPConnectRequest** contents.
+
+|                     |
+|---------------------|
+| Version Number      |
+| Connection MAPSAP   |
+| Domain Reference ID |
+| Priority Range      |
+
+*Version Number:* This field indicates the version of this protocol that the calling node wishes to use. This consists of both a Major and Minor version number. The value of this field for the protocol defined in this Annex is 1.0 (Major version 1, Minor version 0). Note that this is the suggested value. The called node will determine the actual protocol version to be used.
+
+*Connection MAPSAP:* This field tells the receiver which MAP Service Access Point is to handle the incoming connection. The value zero (0) indicates that the caller wishes to access the default MAPSAP. All other values are assigned and obtained out-of-band to this protocol.
+
+*Domain Reference ID:* This field allows the calling node to associate this connection with a particular domain on the called node. When creating the initial connection to a remote node, this field should be set to zero (0). When creating additional connections, or transitioning to a new set of connections, this field should be set to the value that was sent in the **MAPArbitrateProtocolsRequest** on the initial connection. This value, in conjunction with the calling address, allows the called node to know which domain the in-bound connection is to be bound to.
+
+*Priority Range:* This is the priority range of the data that will be carried on this connection. The initial connection to a remote node will always carry *only* priority zero (zero is the highest priority).
+
+### A.9.2 MAPConnectConfirm
+
+This MAPPDU is used to accept a new connection from another node. It informs the calling node of what protocol version will be used on the connection. It also informs the calling node of which remote MAPSAP accepted the call.
+
+The following table summarizes the **MAPConnectConfirm** contents.
+
+|                   |
+|-------------------|
+| Version Number    |
+| Connection MAPSAP |
+
+*Version Number:* This field indicates the version of this protocol that will be used for this connection. This consists of both a Major and Minor version number. The value of this field for the protocol defined in this Annex is 1.0 (Major version 1, Minor version 0). If the calling node cannot handle (or does not want to handle) the version specified by the called node in this MAPPDU, it must disconnect.
+
+*Connection MAPSAP:* This is the MAPSAP on the called node that actually accepted the call. If the MAPSAP specified in the **MAPConnectRequest** was non-zero, then this field should be set the same. If the MAPSAP in the **MAPConnectRequest** was zero, then this field is set to the valid value of the MAPSAP that accepted the call (which may also be zero).
+
+### A.9.3 MAPDisconnectRequest
+
+This MAPPDU is used to break an existing transport connection between two nodes, or to reject an incoming connection if the called node does not wish to participate in the conference. Once this MAPPDU is sent, the connection cannot be used for the transmission of any other data.
+
+If this MAPPDU is being sent as part of a transition to a new set of reliable unicast connections, the sender should set the Confirm Required flag. This informs the receiver that it should respond by issuing a **MAPDisconnectConfirm** on the same connection.
+
+If the Confirm Required flag is set, then the sending node must wait for the **MAPDisconnectConfirm**, before dropping the connection. This is done to ensure that all data is flushed from the connection before shutting it down.
+
+The following table summarizes the **MAPDisconnectRequest** contents.
+
+|                  |
+|------------------|
+| Reason           |
+| Confirm Required |
+
+*Reason:* This field indicates to the recipient why the connection is being broken or rejected.
+
+*Confirm Required:* This is a Boolean flag that indicates whether or not the receiver should respond with a **MAPDisconnectConfirm**. This flag is set if the disconnect is occurring as part of a transition to a different set of reliable unicast connections. Waiting for the confirm allows both sides to know that all MAPPDUs transmitted on this connection have been processed.
+
+### A.9.4 MAPDisconnectConfirm
+
+This MAPPDU is sent in response to a **MAPDisconnectRequest** that has the Confirm Required flag set. By sending this confirm, both sides can be assured that all data has been flushed from the connection before they shut it down and begin using a new one.
+
+Upon receiving this MAPPDU, the node can safely shut down the connection upon which it arrived. Depending on the state of the replacement connections, it may be possible for the node to begin processing data on one or more of those connections.
+
+This MAPPDU has no fields associated with it.
+
+### A.9.5 MAPArbitrateProtocolsRequest
+
+Once a connection has been established for a given domain between two nodes, this MAPPDU can be used to arbitrate which transport protocols are to be used for data delivery. This MAPPDU *must* be sent by the calling node when the initial connection is made. It may also be sent by any node if it becomes desirable to re-arbitrate the transport protocols at any time.
+
+This MAPPDU tells the receiver which transport protocols are supported by the sender. This includes both unicast and multicast protocols, for both reliability levels. Note that it is *mandatory* that the reliable unicast protocol used for the existing connection be represented in this MAPPDU (this allows the receiver to reject a reliable unicast transition simply by selecting the same protocol already in use).
+
+Each transport protocol listed in this MAPPDU can be assigned a preference weighting by the sender. For the multicast protocols, there is also a field to be used by a downward node to indicate how many nodes in its subtree support the protocol. The upward node can use this information to more wisely select multicast protocols for a given metachannel.
+
+This MAPPDU is also used to communicate a domain reference ID to the receiver. This value, in conjunction with the sender's network address, can subsequently be used to uniquely identify a particular domain to the receiver. This is necessary for those cases in which the domain cannot be implied. Specifically, this value is used when creating additional reliable unicast connections, or when sending unreliable data PDUs.
+
+If adjacent nodes both try to originate a re-arbitration at the same time, the request from the downward node is ignored. This situation is detectable at both nodes because they will both receive an arbitration request when they were expecting a confirm. The upward node responds to this by throwing away the request (and continuing to wait for the confirm). The downward node responds by processing the request (and ceasing to wait for the confirm). If the downward node still wishes to perform re-arbitration, it can issue another request (after sending the confirm).
+
+The following table summarizes the **MAPArbitrateProtocolsRequest** contents.
+
+|                         |
+|-------------------------|
+| Domain Reference ID     |
+| More to Come Flag       |
+| Transport Protocol Menu |
+
+*Domain Reference ID:* This is a locally-assigned value used by the sender to reference a particular domain. After the arbitration process is complete, the sender can use this value to indicate which domain a **MAPConnectRequest** PDU is associated with. It is also used to indicate which domain an unreliable **MAPData** PDU is associated with.
+
+*More to Come Flag:* When set, this flag indicates that there are too many transport protocols to fit in one MAPPDU, so the receiver should wait for subsequent **MAPArbitrateProtocolsRequest** PDUs before processing them. The last MAPPDU in the sequence should have this flag reset.
+
+*Transport Protocol Menu:* This field contains a set of Transport Protocol Request Entries. This is a list of the transport protocols that the sender can use in this conference. This should be a complete list of the protocols supported by the sender (unreliable protocols are optional). It is mandatory that the reliable unicast protocol used to transport this MAPPDU be included in the list. There is a field in each entry allowing the caller to specify which protocols it prefers to use. For a given protocol type, the sender should also list the entries in the order of preference. It is the job of the receiver to select which protocols can actually be used for the connection. For the unicast protocols, the receiver should try to select the preferred protocols if possible. For the multicast protocols, the receiver should select all protocols that are common to both sender and receiver. It is okay if there are no common multicast protocols at a given reliability level (all data will be unicast at that reliability level). It is also okay if there is no common unreliable unicast protocol (unreliable data will be sent through the reliable connections).
+
+#### **A.9.5.1 Transport Protocol Request Entry**
+
+The menu is just a set of Transport Protocol Request Entries, the format of which is defined in the following table.
+
+|                                  |
+|----------------------------------|
+| Transport Protocol ID            |
+| Transport Protocol Type          |
+| Network Address                  |
+| Maximum Payload Fixed Flag       |
+| Maximum Payload Size             |
+| Preference Weighting (optional)  |
+| Node Count (optional)            |
+| Number of Connections (optional) |
+| Configuration Data (optional)    |
+
+*Transport Protocol ID:* This field uniquely identifies the transport protocol. Values for this field will have to be standardized, although it will also be possible to specify proprietary values.
+
+*Transport Protocol Type:* This field is set to one of four values: reliable unicast; unreliable unicast; reliable multicast; or unreliable multicast.
+
+*Network Address:* This is the address at which the originator can be reached using this protocol.
+
+*Maximum Payload Fixed Flag:* This is a Boolean flag that indicates whether or not the Maximum Payload Size is negotiable for this Transport Protocol Entry. See the description of Maximum Payload Size for more detail.
+
+*Maximum Payload Size:* This field specifies the maximum payload size supported by this transport protocol. If the Maximum Payload Fixed Flag is reset, then this is the maximum value supported by the local implementation (which can be negotiated down). If the Maximum Payload Fixed Flag is set, then this is the exact value that must be used in order to accept this Transport Protocol Entry. MAP will use the negotiated values to determine the maximum size of a data frame (data frames are discussed in more detail in the section on **MAPData**). The smallest Maximum Payload Size supported by MAP is 128.
+
+*Preference Weighting:* This optional field is used to indicate to the receiver which protocols are preferred. A higher value indicates a protocol that is preferred over one with a lower value. If the field is not included, then a preference weighting of zero is assumed. This field is not used for multicast protocols when the MAPPDU is being sent downward.
+
+*Node Count:* This optional field is only present for the multicast protocols (reliable and unreliable), and only when the MAPPDU is being sent upward. It indicates how many nodes at or below the sender support this multicast protocol entry. This number can be used by the upward node to make better decisions about which multicast protocol to use when mapping a new metachannel to multicast. For this number to remain accurate, a re-arbitration will have to occur whenever a new MAP capable node joins or leaves the conference. This re-arbitration will only occur on the branch of the domain tree that leads to where the node joined or left. In order to reduce network traffic, re-arbitration should not occur *every* time a node joins or leaves once the conference exceeds a certain size. This field can also be used to prevent the use of multicast when there are fewer than  $N$  nodes that will use it ( $N = 3?$ ).
+
+*Number of Connections:* This optional field is only present for the reliable unicast protocol. It indicates the number of transport connections that the sender wishes to create for this one MAP connection (if this protocol is selected). If the receiver does select this protocol, it should choose a number that is less than or equal to the number specified by the sender.
+
+*Configuration Data:* This optional field is a variable length octet string that is used by the transport protocol stacks to pass configuration information. This field will not be present if the transport stacks do not wish to exchange any configuration data, or if this is a re-arbitration and the transport stacks wish to keep the previously agreed upon value. Note that if this field *is* present during a re-arbitration, and this protocol is selected as a unicast protocol, then it is necessary to transition to a new set of unicast connections (since the configuration data may have changed). The format of this field is specific to each transport protocol. For standardized transport protocols, this field will have to be part of a standard. For proprietary transport protocols, it can be whatever the manufacturer thinks is appropriate. This field can be used to communicate capabilities, and can be modified in the **MAPArbitrateProtocolsConfirm** to arbitrate those capabilities. This field must not be so large that the MAPPPDU exceeds 16 384 bytes in size.
+
+### A.9.6 MAPArbitrateProtocolsConfirm
+
+This MAPPPDU is used to finalize arbitration of transport protocols for a given connection. After receiving a **MAPArbitrateProtocolsRequest**, the receiver should respond by issuing this MAPPPDU.
+
+The request MAPPPDU contained a list of all transport protocols supported by the sender (including preferences). The receiver should select from this list the protocols that can be used on this connection. This includes *exactly* one reliable unicast protocol (and, optionally, one unreliable unicast protocol). If the sender specified preferences for the unicast protocols, these should be taken into consideration. The receiver should also determine the complete set of multicast protocols that are common to the two nodes. Returning this common set in the confirm helps to ensure that the best multicast protocols are selected during group allocation.
+
+This MAPPPDU is also used to communicate a domain reference ID to the receiver. This value, in conjunction with the sender's network address, can subsequently be used to uniquely identify a particular domain to the receiver. This is necessary for those cases in which the domain cannot be implied. Specifically, this value is used when sending unreliable data PDUs.
+
+The following table summarizes the **MAPArbitrateProtocolsConfirm** contents.
+
+|                         |
+|-------------------------|
+| Domain Reference ID     |
+| More to Come Flag       |
+| Transport Protocol Menu |
+
+*Domain Reference ID:* This is a locally-assigned value used by the sender to reference a particular domain. After the arbitration process is complete, the sender can use this value to indicate which domain an unreliable **MAPData** PDU is associated with.
+
+*More to Come Flag:* When set, this flag indicates that there are too many transport protocols to fit in one MAPPPDU, so the receiver should wait for subsequent **MAPArbitrateProtocolsConfirm** PDUs before processing them. The last MAPPPDU in the sequence should have this flag reset.
+
+*Transport Protocol Menu:* This field contains a set of Transport Protocol Confirm Entries. This is a list of the transport protocols that the called node has decided to use on this connection. As a minimum, the called node must indicate a reliable unicast protocol. Optionally, it can indicate an unreliable unicast protocol and protocols for the multicast reliability levels. If an unreliable unicast protocol is not included, then unreliable data will be unicast over the reliable connections. If a given multicast reliability level is not included, then all data at that reliability level will be unicast between these two nodes (multicast islands will be split for that reliability level). If the arbitrated unicast protocols are different than the ones already in use, then a unicast protocol transition must take place.
+
+#### A.9.6.1 Transport Protocol Confirm Entry
+
+The menu is just a set of Transport Protocol Confirm Entries, the format of which is defined in the following table.
+
+|                                  |
+|----------------------------------|
+| Transport Protocol ID            |
+| Transport Protocol Type          |
+| Network Address                  |
+| Maximum Payload Size             |
+| Preference Weighting (optional)  |
+| Node Count (optional)            |
+| Number of Connections (optional) |
+| Configuration Data (optional)    |
+
+*Transport Protocol ID:* This field uniquely identifies the transport protocol. Values for this field will have to be standardized, although it will also be possible to specify proprietary values.
+
+*Transport Protocol Type:* This field is set to one of four values: reliable unicast; unreliable unicast; reliable multicast; or unreliable multicast.
+
+*Network Address:* This is the address at which the originator can be reached using this protocol.
+
+*Maximum Payload Size:* This field specifies the maximum payload size that will be used by this transport protocol. Note that the maximum payload size for a given multicast protocol *must* be the same as the maximum payload size for the unicast protocol at the same reliability level. This is due to the fact that data frames at that reliability level may have to be redirected via unicast at some points within the multicast island. The smallest Maximum Payload Size supported by MAP is 128.
+
+*Preference Weighting:* This optional field is used to indicate to the receiver which protocols are preferred. A higher value indicates a protocol that is preferred over one with a lower value. If the field is not included, then a preference weighting of zero is assumed. This field is only used for multicast protocols when the MAPPDU is being sent upward.
+
+*Node Count:* This optional field is only present for the multicast protocols (reliable and unreliable), and only when the MAPPDU is being sent upward. It indicates how many nodes at or below the sender support this multicast protocol entry. This number can be used by the upward node to make better decisions about which multicast protocol to use when mapping a new metachannel to multicast. For this number to remain accurate, a re-arbitration will have to occur whenever a new MAP capable node joins or leaves the conference. This re-arbitration will only occur on the branch of the domain tree that leads to where the node joined or left. In order to reduce network traffic, re-arbitration should not occur *every* time a node joins or leaves once the conference exceeds a certain size. This field can also be used to prevent the use of multicast when there are fewer than  $N$  nodes that will use it ( $N = 3?$ ).
+
+*Number of Connections:* This optional field is only present for the unicast protocols. It indicates the number of transport connections that will be created for this one MAP connection (at this reliability level). This number should be the lesser of the requested value, and the locally supported value.
+
+*Configuration Data:* This optional field is a variable length octet string that is used by the transport protocol stacks to pass configuration information. This field will not be present if the transport stacks do not wish to exchange any configuration data, or if this is a re-arbitration and the transport stacks wish to keep the previously agreed upon value. Note that if this field *is* present during a
+
+re-arbitration, and this protocol is selected as a unicast protocol, then it is necessary to transition to a new set of unicast connections (since the configuration data may have changed). The format of this field is specific to each transport protocol. For standardized transport protocols, this field will have to be part of the standard. For proprietary stacks, it can be whatever the manufacturer thinks is appropriate. This field can be used to communicate capabilities, and can be modified to arbitrate those capabilities. This field must not be so large that the MAPDU exceeds 16 384 bytes in size.
+
+### A.9.7 MAPData
+
+This MAPDU is the workhorse of the protocol. It is used to carry all user data to its eventual destination. Unlike the TCP/IP stack defined in Recommendation T.123, MAP allows for the concatenation of multiple MCSPDUs into a single **MAPData** PDU (to promote efficient use of the network). MAP also allows for the segmentation of a single MCSPDU into multiple **MAPData** PDUs (when the MCSPDU exceeds the Maximum Payload Size).
+
+Each individual data component of a **MAPData** PDU is referred to as a *data frame*. There can be one or many data frames in a single **MAPData** PDU. The maximum size of a data frame is determined during transport protocol arbitration. It is the largest size that will fit into the maximum payload for a given reliability level (after taking overhead into consideration). The maximum data frame size for one reliability level may be different than that for a different reliability level.
+
+MCSPDUs are broken into data frames at the node acting as the original point-of-entry for the data flow. If necessary, they are re-assembled at all receiving nodes.
+
+**MAPData** supports the notion of header compression. There are several fields in the **MAPData** header that are also included in the MCS data PDU header. If these fields can be extracted from the MCS header of the first data frame in the MAPDU, then they may not be included in the **MAPData** header (they are optional fields). If the first data frame in the MAPDU is a segmented MCS data PDU, the sender will decide whether or not enough of the MCS header is present to extract these fields. The receiver must be prepared to extract these fields if they are not explicitly included in the **MAPData** header.
+
+The following table summarizes the **MAPData** contents.
+
+|                            |
+|----------------------------|
+| Data Descriptor (optional) |
+| Data Frame Array           |
+
+*Data Descriptor*: This optional field is only present when sending MCS data PDUs. When present, the fields within this descriptor describe the data contained in this MAPDU. If this field is not present, then this MAPDU contains MCS control PDUs, which are to be forwarded directly to MCS at the receiving node.
+
+*Data Frame Array*: This is a sequence of Data Frame Entries (as defined below).
+
+#### A.9.7.1 Data Descriptor
+
+A Data Descriptor is only present in a **MAPData** PDU if it is carrying MCS data PDUs. The following table summarizes the Data Descriptor contents.
+
+|                                 |
+|---------------------------------|
+| Unicast Forward Flag            |
+| Starting Sequence Number        |
+| Data Flow Identifier (optional) |
+| Domain Reference ID (optional)  |
+
+*Unicast Forward Flag:* This flag is used to force the recipient to forward this MAPPDU via unicast. When this flag is set, the recipient must begin transmitting all data on this data flow via unicast (even to neighboring nodes that have previously disabled unicast). The mandatory unicast transmission begins with this MAPPDU. This flag should remain set when the PDU is forwarded. Once a sender chooses to set this flag for a particular data flow, the flag must be set for all subsequent **MAPData** PDUs on the same data flow (to avoid race conditions). If this flag is reset, then this MAPPDU should be treated normally.
+
+*Starting Sequence Number:* This field contains the unique sequence number assigned to the first data frame in this MAPPDU. Subsequent data frames in this MAPPDU simply increment from this starting sequence number. Sequence numbers are independently assigned to each data frame by the originator of the data flow.
+
+*Data Flow Identifier:* This optional field must be present if the information cannot be extracted from the first data frame. The fields making up the data flow identifier are those that are required to properly route the data, and to determine which unique data flow the data frames are associated with (which in turn identifies the sequence counter).
+
+*Domain Reference ID:* This optional field is only present for unreliable data. This is the Domain Reference ID that was transmitted by the sender during protocol arbitration. This field may be present for multicast transmissions (for performance reasons), but should be ignored. This value, combined with the network address of the originator, is sufficient to uniquely determine which domain the data is associated with.
+
+#### **A.9.7.2 Data flow identifier**
+
+A data flow identifier is used to identify which data flow a set of data frames is associated with. This information must be explicitly included if it cannot be extracted from the first data frame. The following table summarizes the Data Flow Identifier contents.
+
+|                           |
+|---------------------------|
+| Sender ID (optional)      |
+| Metachannel ID (optional) |
+| Channel ID                |
+| Reliability Level         |
+| Priority                  |
+| Data Type (optional)      |
+
+*Sender ID:* This optional field is only present for non-uniform data, or for uniform or proxy data flowing upward via unicast. This field may also be excluded if the information can be extracted from the MCS header of the first data frame. This field indicates the MCS User ID of the user application that originated the data associated with this data flow.
+
+*Metachannel ID:* This optional field may be excluded if the information can be extracted from the MCS header of the first data frame. This field identifies which metachannel is being referenced, and contains three sub-fields: channel ID; reliability level; and priority.
+
+*Data Type:* This optional field may be excluded if the information can be extracted from the MCS header of the first data frame. This field indicates what type of data this is. This is one of: non-uniform; uniform; or proxy.
+
+#### A.9.7.3 Data frame entry
+
+**MAPData** PDUs contain an array of data frames. The following table summarizes the Data Frame Entry contents.
+
+|                    |
+|--------------------|
+| First Segment Flag |
+| Last Segment Flag  |
+| User Data          |
+
+*First Segment Flag:* This flag indicates whether or not this data frame is the first segment of a MCSPDU. If this flag is set, then this is the first data frame in a MCSPDU. If this flag is reset, then this is not the first data frame in a MCSPDU.
+
+*Last Segment Flag:* This flag indicates whether or not this data frame is the last segment of a MCSPDU. If this flag is set, then this is the last data frame in a MCSPDU. If this flag is reset, then this is not the last data frame in a MCSPDU.
+
+*User Data:* This is the user data from the MCSPDU.
+
+### A.9.8 MAPAddGroupRequest
+
+This MAPPDU is used to propagate multicast group assignments downward within a domain. This is done whenever MAP detects a data flow for which there is no group assignment. This process is originated by each node in the domain that either has no upward MAP connection, or has an upward MAP connection but no common multicast protocols with the node above. This process is continued by each node that receives a **MAPAddGroupRequest** from the node above it.
+
+Each node should examine the lists of multicast protocols that are supported by the nodes beneath it (these lists are constructed during transport protocol arbitration). Based on this information, each node must tell the nodes beneath it which multicast protocol and group address to use. It should select those protocol(s) that will result in the fewest, largest multicast islands.
+
+When selecting a protocol for each downward node, there are several things that should be considered:
+
+- 1) *What protocol versions are in use at the downward nodes?* During connection establishment, both MCS and MAP arbitrate protocol versions with each adjacent node. When selecting multicast protocols for the downward nodes, remember that nodes using different protocol versions *cannot* be in the same multicast island (even if they support the same multicast protocol). This is simply because PDU formats are different.
+- 2) *What protocols are supported by the downward nodes?* Obviously, a node can only select from those protocols that the downward nodes have agreed to support. It should attempt to select the protocols that are most broadly supported.
+- 3) *What maximum payload sizes were arbitrated with the downward nodes?* During protocol arbitration, each node should attempt to select the same maximum payload sizes that have already been arbitrated with other connections in the same domain. If different nodes insist on different maximum payload sizes, then they cannot be in the same multicast island (all nodes in an island must agree on the same maximum payload size, for both unicast and multicast).
+
+- 4) *What protocol was assigned from above?* If a node is performing this selection in response to a **MAPAddGroupRequest** from above, then it should try to use the same protocol that was assigned to it (when possible). This is based on the fact that the node above has broader visibility, and can therefore make better decisions.
+- 5) *How many nodes in each subtree support each protocol?* During protocol arbitration, downward nodes include a node count with each multicast protocol that they agree to use. This number tells the upward node how many nodes in each of its subtrees support that protocol. By summing these numbers for all downward connections, a node can choose the multicast protocol with the broadest support. This gives some visibility beyond one level of the domain hierarchy.
+- 6) *Which protocols are preferred?* During protocol arbitration, downward nodes can also communicate their protocol preferences. This information could be used to finalize a protocol selection if the other factors do not clearly indicate a better choice.
+
+Once a multicast protocol has been selected for each downward node, this information is communicated to those nodes by sending a **MAPAddGroupRequest** to each of them. This will cause each receiving node to add that group to their list of active groups. It will also cause each node to continue propagating the group assignment downward by repeating the above steps for each of their downward connections.
+
+Since **MAPAddGroupRequest** specifies the range of priorities that are to use the multicast group, it is possible for different priorities to use different groups (even for the same channel). When determining which multicast group to send data to, MAP uses channel ID, reliability level, *and* priority. If a given priority is not mapped to multicast, then data at that priority is sent via unicast.
+
+Note that not all nodes in a multicast island will need to join a multicast group immediately. A node will join the group if any of the following conditions are true: if there are local user attachments that need to receive the data; if there are connections through other transport stacks that need to receive the data; or if this node must redirect the data via unicast to any neighbors. Some transport protocols may also require a node to join a group before transmitting data to it (even if that node has no interest in receiving data from the group).
+
+The following table summarizes the **MAPAddGroupRequest** contents.
+
+|                         |
+|-------------------------|
+| Metachannel             |
+| Transport Protocol ID   |
+| Multicast Group Address |
+
+*Metachannel:* This field indicates which metachannel is being mapped to a multicast group.
+
+*Transport Protocol ID:* This field uniquely identifies the transport protocol to be used for this metachannel.
+
+*Multicast Group Address:* This is the multicast group address upon which the data for the metachannel will be sent. This field is formatted as an NSAP address.
+
+#### A.9.8.1 Metachannel
+
+The following table defines the fields that make up a metachannel. This type is used to identify the abstraction that MAP assigns multicast groups to.
+
+|                   |
+|-------------------|
+| Channel ID        |
+| Reliability Level |
+| Priority Range    |
+
+*Channel ID:* This field indicates which MCS channel is associated with the metachannel.
+
+*Reliability Level:* This field indicates which reliability level is associated with the metachannel.
+
+*Priority Range:* This is the priority range that is associated with the metachannel (zero is the highest priority).
+
+### A.9.9 MAPRemoveGroupRequest
+
+This MAP PDU is used to remove multicast groups from downward nodes in the multicast island. This process is originated by the Multicast Group Provider when it becomes necessary to remove a multicast group from use. When a node receives a **MAPRemoveGroupRequest**, it must forward the request downward to any nodes beneath it in the multicast island.
+
+Typically, a **MAPRemoveGroupRequest** will not be issued downward until use of the multicast group has already stopped. It is possible to ensure that a multicast group is not being actively used by issuing a **MAPDisableMulticastRequest** downward, and waiting for a **MAPDisableMulticastConfirm** (from all downward nodes in the multicast island). Once this is done, the Multicast Group Provider can be assured that no one is using the group, so it can be removed without fear of data loss.
+
+When a node receives a **MAPRemoveGroupRequest**, it should immediately remove the group and forward the request downward toward all lower nodes in the island.
+
+The following table summarizes the **MAPRemoveGroupRequest** contents.
+
+|             |
+|-------------|
+| Metachannel |
+|-------------|
+
+*Metachannel:* This field indicates which metachannel the group is being removed from.
+
+### A.9.10 MAPDisableUnicastRequest
+
+This MAP PDU is used to disable unicast data from a neighboring node for a specified data flow.
+
+A node should not transmit this MAP PDU until it has verified that it can transition to multicast reception without losing any data. To do this it must have received at least one data frame via unicast, in order to know what the next expected sequence number is. Furthermore, it must receive a data frame via multicast with a sequence number less than or equal to the expected sequence number (so that it knows it is synchronized). Only then will it know that it is okay to shut off the flow of unicast data (for that data flow).
+
+The following table summarizes the **MAPDisableUnicastRequest** contents.
+
+|                      |
+|----------------------|
+| Data Flow Identifier |
+|----------------------|
+
+*Data Flow Identifier:* This field contains the information necessary to determine which data flow unicast is being disabled for. The data flow identifier is fully defined in the subclause discussing the **MAPData** PDU. Sender ID will be omitted for downward flowing uniform and proxy data flows, but will otherwise be present. Metachannel ID and Data Type will always be present.
+
+### A.9.11 MAPEnableUnicastRequest
+
+This MAPDU is used to re-enable unicast from a neighboring node for a specified data flow.
+
+This MAPDU would be sent if a node determines that it is no longer receiving data via multicast, or that the error rates for multicast transmission are so high that it is not efficient to use it. There must be some local communication between MAP and the transport protocol to determine when this is necessary. This could also happen in response to **MAPSequenceNumber** PDUs that have revealed a stoppage in multicast data flow.
+
+The following table summarizes the **MAPEnableUnicastRequest** contents.
+
+|                      |
+|----------------------|
+| Data Flow Identifier |
+|----------------------|
+
+*Data Flow Identifier:* This field contains the information necessary to determine which data flow unicast is being enabled for. The data flow identifier is fully defined in the subclause discussing the **MAPData** PDU. Sender ID will be omitted for downward flowing uniform and proxy data flows, but will otherwise be present. Metachannel ID and Data Type will always be present.
+
+### A.9.12 MAPEnableUnicastConfirm
+
+This MAPDU confirms that unicast has been re-established for the specified data flow. When a node tells a neighboring node to turn unicast back on, it may still be necessary for it to receive more data via multicast. This would happen if it is already too late for the neighboring node to send some data frames via unicast, because they have already passed through. This MAPDU allows the neighboring node to tell the originator of the **MAPEnableUnicastRequest** what the next sequence number that will be unicast is. That way, the node can continue to use multicast (if possible) to listen for all data frames up through that one. This is necessary in order to ensure that no data are lost during the transition from multicast back to unicast.
+
+For example, a node has received sequence numbers through 20 for a given data flow (but with very high error rates). It may elect to turn on unicast to better deal with the errors. However, the neighboring node may have already processed sequence numbers through 23 for that data flow. If the node immediately begins relying on unicast, it will miss sequence numbers 21 through 23. This confirm tells the originator of the request that the next sequence number it will unicast will be 24, so all sequence numbers through 23 must be received via multicast before it can depend on unicast.
+
+The following table summarizes the **MAPEnableUnicastConfirm** contents.
+
+|                      |
+|----------------------|
+| Data Flow Identifier |
+| Sequence Number      |
+
+*Data Flow Identifier:* This field contains the information necessary to determine which data flow unicast is being enabled for. The data flow identifier is fully defined in the subclause discussing the **MAPData** PDU. Sender ID will be omitted for downward flowing uniform and proxy data flows, but will otherwise be present. Metachannel ID and Data Type will always be present.
+
+*Sequence Number:* This is the next sequence number in the data flow that will travel to the node via unicast. Anything prior to this sequence number must be received via multicast before the node can depend on the unicast data stream.
+
+### A.9.13 MAPDisableMulticastRequest
+
+This MAPPDU is transmitted downward in the multicast island to disable the use of multicast prior to group removal.
+
+When a node receives a **MAPDisableMulticastRequest**, it must initiate the process of re-enabling unicast for any data flows for which unicast was previously disabled (for this group). It does this by sending a **MAPEnableUnicastRequest** in the direction of the sender for each affected data flow. The node should also mark the group as being in the disabled state, which prohibits the node from disabling unicast for any data flows on the group. It should NOT, however, stop transmitting to the group.
+
+The **MAPDisableMulticastRequest** should be repeated downward to all nodes that lie beneath the receiver. A node cannot respond with a **MAPDisableMulticastConfirm** until it has received similar confirms from all downward nodes, AND it has successfully re-enabled unicast for all data flows for which unicast was previously disabled (for this group). It cannot assume that unicast is re-enabled for a data flow until it has received a **MAPEnableUnicastConfirm** for each outstanding request (and it must have received all data via multicast with a sequence number less than the one in each confirm).
+
+The following table summarizes the **MAPDisableMulticastRequest** contents.
+
+|             |
+|-------------|
+| Metachannel |
+|-------------|
+
+*Metachannel:* This is the metachannel associated with the group for which multicast is being disabled. The metachannel type is fully described in the subclause on **MAPRemoveGroupRequest**.
+
+### A.9.14 MAPDisableMulticastConfirm
+
+This MAPPDU is used to confirm that all nodes beneath the receiver have stopped using a multicast group.
+
+When a node receives a **MAPDisableMulticastRequest** from the node above, it should respond by sending a **MAPDisableMulticastConfirm** after two conditions have been met: it must have received **MAPDisableMulticastConfirm** PDUs from all nodes beneath it in the multicast island (if any); and it must be sure that unicast is enabled for all data flows on the group.
+
+The first condition is met as a result of forwarding the **MAPDisableMulticastRequest** to the downward nodes. The second condition is met by re-enabling unicast for any data flows that were previously disabled (this is done using the **MAPEnableUnicastRequest** PDU).
+
+The following table summarizes the **MAPDisableMulticastConfirm** contents.
+
+|             |
+|-------------|
+| Metachannel |
+|-------------|
+
+*Metachannel:* This is the metachannel associated with the group for which multicast has been disabled. The metachannel type is fully described in the subclause on **MAPRemoveGroupRequest**.
+
+### A.9.15 MAPEnableMulticastRequest
+
+This MAPPDU is used to re-enable a multicast group that was previously disabled.
+
+When a node receives a **MAPEnableMulticastRequest** for a group that is marked disabled (but still valid), it will re-enable the use of that group. This means that **MAPDisableUnicastRequest** PDUs can again be processed in order to shut off unicast data flow. A re-enabled group takes on the same state it had when first created.
+
+This request should be repeated downward to all nodes that lie beneath the receiver.  
+The following table summarizes the **MAPEnableMulticastRequest** contents.
+
+|             |
+|-------------|
+| Metachannel |
+|-------------|
+
+*Metachannel:* This is the metachannel associated with the group for which multicast is being re-enabled. The metachannel type is fully described in the subclause on **MAPRemoveGroupRequest**.
+
+### **A.9.16 MAPSequenceNumber**
+
+This MAPPDU is used to inform downstream receivers of what sequence numbers they should have received up until the current time. This MAPPDU is propagated outward from the originator of the data flow via unicast, and is repeated by all receiving nodes to those nodes that lie farther from the sender (across the upward connection, as well as any downward connections that lead to users joined to the specified channel). In this way, all nodes can be informed of what sequence numbers for the data flow should have been received.
+
+This MAPPDU could be used to determine when a node simply stops receiving data on a multicast group. This could be useful for unreliable protocols where there is no attempt at error correction. It may also be useful for transport protocols that do not cleanly detect the loss of a multicast pathway from a sender to a receiver. The exact use of the MAPPDU is for further study.
+
+The following table summarizes the **MAPSequenceNumber** contents.
+
+|                      |
+|----------------------|
+| Data Flow Identifier |
+| Sequence Number      |
+
+*Data Flow Identifier:* This field contains the information necessary to determine which data flow this sequence number is associated with. The data flow identifier is fully defined in the subclause discussing the **MAPData** PDU. Sender ID will be omitted for downward flowing uniform and proxy data flows, but will otherwise be present. Metachannel ID and Data Type will always be present.
+
+*Sequence Number:* This is the last sequence number that was transmitted for the specified data flow.
+
+## **A.10 MAPPDU ASN.1 Definition**
+
+This subclause contains the actual format of the MAPPDUs, using the ASN.1 notation. The contents of this subclause will also be made available as a separate, compilable, text file.
+
+```
+--*****
+--*
+--*      ASN.1 Definition for MAP PDUs
+--*
+--*****
+```
+
+**MAP-PROTOCOL DEFINITIONS AUTOMATIC TAGS ::=**
+
+**BEGIN**
+
+**H221NonStandardIdentifier ::= OCTET STRING (SIZE (4..255))**
+
+```
+
+Key ::= CHOICE
+{
+    object                OBJECT IDENTIFIER,
+    h221NonStandard       H221NonStandardIdentifier
+}
+
+NonStandardParameter ::= SEQUENCE
+{
+    key                   Key,
+    data                  OCTET STRING
+}
+
+NonStandardPDU ::= SEQUENCE
+{
+    data                  NonStandardParameter,
+    ...
+}
+
+VersionNumber ::= SEQUENCE
+{
+    majorVersionNumber    INTEGER (0 .. 65535),
+    minorVersionNumber    INTEGER (0 .. 65535),
+    nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+Priority ::= INTEGER (0 .. 15)
+
+PriorityRange ::= SEQUENCE
+{
+    highPriority           Priority,
+    lowPriority            Priority,
+    nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+MAPConnectRequestPDU ::= SEQUENCE
+{
+    versionNumber          VersionNumber,
+    connectionMAPSAP       INTEGER (0 .. 65535),
+    domainReferenceID      INTEGER (0 .. 65535),
+    priorityRange          PriorityRange,
+    nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+MAPConnectConfirmPDU ::= SEQUENCE
+{
+    versionNumber          VersionNumber,
+    connectionMAPSAP       INTEGER (0 .. 65535),
+    nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+Reason ::= CHOICE
+{
+    providerInitiated      NULL,
+    userRejected           NULL,
+    userInitiated          NULL,
+    invalidMAPSAP          NULL,
+    invalidDomainReferenceID NULL,
+}
+
+```
+
+```
+
+        unicastTransition                NULL,
+        unspecifiedFailure                NULL,
+        nonStandardReason                NonStandardParameter,
+        ...
+    }
+
+MAPDisconnectRequestPDU ::= SEQUENCE
+{
+    reason                                Reason,
+    confirmRequired                       BOOLEAN,
+    nonStandardParameters                 SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+MAPDisconnectConfirmPDU ::= SEQUENCE
+{
+    nonStandardParameters                 SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+TransportProtocolID ::= CHOICE
+{
+    objectProtocolID                      OBJECT IDENTIFIER,
+    h221NonStandardProtocolID             H221NonStandardIdentifier,
+    snapProtocolID                         OCTET STRING (SIZE (5)),
+    nonStandardProtocolID                  NonStandardParameter,
+    ...
+}
+
+TransportProtocolType ::= CHOICE
+{
+    reliableUnicast                       NULL,
+    unreliableUnicast                     NULL,
+    reliableMulticast                      NULL,
+    unreliableMulticast                   NULL,
+    nonStandardProtocolType                NonStandardParameter,
+    ...
+}
+
+NetworkAddress ::= SEQUENCE
+{
+    nsapAddress                           OCTET STRING (SIZE (1..20)),
+    nonStandardParameters                 SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+PayloadSize ::= INTEGER (128 .. 65535)
+
+TransportProtocolRequestEntry ::= SEQUENCE
+{
+    transportProtocolID                    TransportProtocolID,
+    transportProtocolType                  TransportProtocolType,
+    networkAddress                         NetworkAddress,
+    maximumPayloadFixedFlag                BOOLEAN,
+    maximumPayloadSize                     PayloadSize,
+    preferenceWeighting                    INTEGER (0 .. 65535) OPTIONAL,
+    nodeCount                              INTEGER (0 .. 65535) OPTIONAL,
+    numberOfConnections                    INTEGER (0 .. 65535) OPTIONAL,
+    configurationData                      OCTET STRING OPTIONAL,
+
+```
+
+```
+
+        nonStandardParameters          SEQUENCE OF NonStandardParameter OPTIONAL,
+        ...
+    }
+
+MAPArbitrateProtocolsRequestPDU ::= SEQUENCE
+{
+    domainReferenceID                  INTEGER (0 .. 65535),
+    moreToComeFlag                     BOOLEAN,
+    transportProtocolMenu              SEQUENCE OF TransportProtocolRequestEntry,
+    nonStandardParameters              SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+TransportProtocolConfirmEntry ::= SEQUENCE
+{
+    transportProtocolID                TransportProtocolID,
+    transportProtocolType              TransportProtocolType,
+    networkAddress                    NetworkAddress,
+    maximumPayloadSize                 PayloadSize,
+    preferenceWeighting                INTEGER (0 .. 65535) OPTIONAL,
+    nodeCount                         INTEGER (0 .. 65535) OPTIONAL,
+    numberOfConnections                INTEGER (0 .. 65535) OPTIONAL,
+    configurationData                  OCTET STRING OPTIONAL,
+    nonStandardParameters              SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+MAPArbitrateProtocolsConfirmPDU ::= SEQUENCE
+{
+    domainReferenceID                  INTEGER (0 .. 65535),
+    moreToComeFlag                     BOOLEAN,
+    transportProtocolMenu              SEQUENCE OF TransportProtocolConfirmEntry,
+    nonStandardParameters              SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+SenderID ::= INTEGER (1001 .. 65535)
+
+ChannelID ::= INTEGER (1 .. 65535)
+
+ReliabilityLevel ::= CHOICE
+{
+    reliable                          NULL,
+    unreliable                        NULL,
+    nonStandardReliabilityLevel       NonStandardParameter,
+    ...
+}
+
+DataType ::= CHOICE
+{
+    nonuniform                        NULL,
+    uniform                          NULL,
+    proxy                            NULL,
+    nonStandardDataType               NonStandardParameter,
+    ...
+}
+
+DataFlowIdentifier ::= SEQUENCE
+{
+    senderID                          SenderID OPTIONAL,
+
+```
+
+```
+
+    metachannelID SEQUENCE
+    {
+        channelID                ChannelID,
+        reliabilityLevel          ReliabilityLevel,
+        priority                  Priority,
+        ...
+    } OPTIONAL,
+
+    dataType                     DataType OPTIONAL,
+    nonStandardParameters        SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+SequenceNumber ::= INTEGER (0 .. 65535)
+
+DataDescriptor ::= SEQUENCE
+{
+    unicastForwardFlag          BOOLEAN,
+    startingSequenceNumber      SequenceNumber,
+    dataFlowIdentifier          DataFlowIdentifier OPTIONAL,
+    domainReferenceID           INTEGER (0 .. 65535) OPTIONAL,
+    nonStandardParameters        SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+DataFrameEntry ::= SEQUENCE
+{
+    firstSegmentFlag            BOOLEAN,
+    lastSegmentFlag             BOOLEAN,
+    userData                    OCTET STRING,
+    nonStandardParameters        SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+MAPDataPDU ::= SEQUENCE
+{
+    dataDescriptor              DataDescriptor OPTIONAL,
+    dataFrameArray              SEQUENCE OF DataFrameEntry,
+    nonStandardParameters        SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+Metachannel ::= SEQUENCE
+{
+    channelID                   ChannelID,
+    reliabilityLevel            ReliabilityLevel,
+    priorityRange               PriorityRange,
+    nonStandardParameters        SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+MAPAddGroupRequestPDU ::= SEQUENCE
+{
+    metachannel                 Metachannel,
+    transportProtocolID         TransportProtocolID,
+    multicastGroupAddress        NetworkAddress,
+    nonStandardParameters        SEQUENCE OF NonStandardParameter OPTIONAL,
+    ...
+}
+
+```
+
+**MAPRemoveGroupRequestPDU ::= SEQUENCE**
+
+```
+{  
+    metachannel                Metachannel,  
+    nonStandardParameters      SEQUENCE OF NonStandardParameter OPTIONAL,  
+    ...  
+}
+```
+
+**MAPDisableUnicastRequestPDU ::= SEQUENCE**
+
+```
+{  
+    dataFlowIdentifier          DataFlowIdentifier,  
+    nonStandardParameters      SEQUENCE OF NonStandardParameter OPTIONAL,  
+    ...  
+}
+```
+
+**MAPEnableUnicastRequestPDU ::= SEQUENCE**
+
+```
+{  
+    dataFlowIdentifier          DataFlowIdentifier,  
+    nonStandardParameters      SEQUENCE OF NonStandardParameter OPTIONAL,  
+    ...  
+}
+```
+
+**MAPEnableUnicastConfirmPDU ::= SEQUENCE**
+
+```
+{  
+    dataFlowIdentifier          DataFlowIdentifier,  
+    sequenceNumber              SequenceNumber,  
+    nonStandardParameters      SEQUENCE OF NonStandardParameter OPTIONAL,  
+    ...  
+}
+```
+
+**MAPDisableMulticastRequestPDU ::= SEQUENCE**
+
+```
+{  
+    metachannel                Metachannel,  
+    nonStandardParameters      SEQUENCE OF NonStandardParameter OPTIONAL,  
+    ...  
+}
+```
+
+**MAPDisableMulticastConfirmPDU ::= SEQUENCE**
+
+```
+{  
+    metachannel                Metachannel,  
+    nonStandardParameters      SEQUENCE OF NonStandardParameter OPTIONAL,  
+    ...  
+}
+```
+
+**MAPEnableMulticastRequestPDU ::= SEQUENCE**
+
+```
+{  
+    metachannel                Metachannel,  
+    nonStandardParameters      SEQUENCE OF NonStandardParameter OPTIONAL,  
+    ...  
+}
+```
+
+**MAPSequenceNumberPDU ::= SEQUENCE**
+
+```
+{  
+    dataFlowIdentifier          DataFlowIdentifier,  
+    sequenceNumber              SequenceNumber,  
+    nonStandardParameters      SEQUENCE OF NonStandardParameter OPTIONAL,  
+    ...  
+}
+```
+
+**MAPPDU ::= CHOICE**
+
+```
+{
+    mapConnectRequest          MAPConnectRequestPDU,
+    mapConnectConfirm          MAPConnectConfirmPDU,
+    mapDisconnectRequest       MAPDisconnectRequestPDU,
+    mapDisconnectConfirm       MAPDisconnectConfirmPDU,
+    mapArbitrateProtocolsRequest MAPArbitrateProtocolsRequestPDU,
+    mapArbitrateProtocolsConfirm MAPArbitrateProtocolsConfirmPDU,
+    mapData                    MAPDataPDU,
+    mapAddGroupRequest         MAPAddGroupRequestPDU,
+    mapRemoveGroupRequest      MAPRemoveGroupRequestPDU,
+    mapDisableUnicastRequest   MAPDisableUnicastRequestPDU,
+    mapEnableUnicastRequest    MAPEnableUnicastRequestPDU,
+    mapEnableUnicastConfirm    MAPEnableUnicastConfirmPDU,
+    mapDisableMulticastRequest MAPDisableMulticastRequestPDU,
+    mapDisableMulticastConfirm MAPDisableMulticastConfirmPDU,
+    mapEnableMulticastRequest  MAPEnableMulticastRequestPDU,
+    mapSequenceNumber          MAPSequenceNumberPDU,
+    nonStandardPDU             NonStandardPDU,
+    ...
+}
+```
+
+**END**
+
+```
+--*****
+--*
+--*      End of ASN.1 Definition for MAP PDUs
+--*
+--*****
+```
+
+
+
+# ITU-T RECOMMENDATIONS SERIES
+
+|                 |                                                                                                                                |
+|-----------------|--------------------------------------------------------------------------------------------------------------------------------|
+| Series A        | Organization of the work of the ITU-T                                                                                          |
+| Series B        | Means of expression: definitions, symbols, classification                                                                      |
+| Series C        | General telecommunication statistics                                                                                           |
+| Series D        | General tariff principles                                                                                                      |
+| Series E        | Overall network operation, telephone service, service operation and human factors                                              |
+| Series F        | Non-telephone telecommunication services                                                                                       |
+| Series G        | Transmission systems and media, digital systems and networks                                                                   |
+| Series H        | Audiovisual and multimedia systems                                                                                             |
+| Series I        | Integrated services digital network                                                                                            |
+| Series J        | Transmission of television, sound programme and other multimedia signals                                                       |
+| Series K        | Protection against interference                                                                                                |
+| Series L        | Construction, installation and protection of cables and other elements of outside plant                                        |
+| Series M        | TMN and network maintenance: international transmission systems, telephone circuits, telegraphy, facsimile and leased circuits |
+| Series N        | Maintenance: international sound programme and television transmission circuits                                                |
+| Series O        | Specifications of measuring equipment                                                                                          |
+| Series P        | Telephone transmission quality, telephone installations, local line networks                                                   |
+| Series Q        | Switching and signalling                                                                                                       |
+| Series R        | Telegraph transmission                                                                                                         |
+| Series S        | Telegraph services terminal equipment                                                                                          |
+| <b>Series T</b> | <b>Terminals for telematic services</b>                                                                                        |
+| Series U        | Telegraph switching                                                                                                            |
+| Series V        | Data communication over the telephone network                                                                                  |
+| Series X        | Data networks and open system communication                                                                                    |
+| Series Y        | Global information infrastructure                                                                                              |
+| Series Z        | Programming languages                                                                                                          |
\ No newline at end of file
diff --git a/marked/T/T-REC-T.126-200708-I_PDF-E/007b053fe94a8348f75128a584503fd0_img.jpg b/marked/T/T-REC-T.126-200708-I_PDF-E/007b053fe94a8348f75128a584503fd0_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..1a9c037e5fbf072df31bdd6080a4e2244f2c35b0
--- /dev/null
+++ b/marked/T/T-REC-T.126-200708-I_PDF-E/007b053fe94a8348f75128a584503fd0_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:bfd9398e7ba48df02e755b0ad7383f546fc448f61ac1035275f40b016496d9c0
+size 56958
diff --git a/marked/T/T-REC-T.126-200708-I_PDF-E/3121ebddccf183ca63bb9781be440a7e_img.jpg b/marked/T/T-REC-T.126-200708-I_PDF-E/3121ebddccf183ca63bb9781be440a7e_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..70443ff5b232cfa589454fcab0ca2802f4b18f22
--- /dev/null
+++ b/marked/T/T-REC-T.126-200708-I_PDF-E/3121ebddccf183ca63bb9781be440a7e_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:829184124e36593fa08d12c9967c3e645597062d3899d47a863ecaf3cb159731
+size 111828
diff --git a/marked/T/T-REC-T.126-200708-I_PDF-E/94fd137860c16c8dfd75512f10161fe8_img.jpg b/marked/T/T-REC-T.126-200708-I_PDF-E/94fd137860c16c8dfd75512f10161fe8_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..1b5888ca6ef777f0500c64d6afcc46f8a12a6deb
--- /dev/null
+++ b/marked/T/T-REC-T.126-200708-I_PDF-E/94fd137860c16c8dfd75512f10161fe8_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:075c4ff5a294d1af08712de9a9abbaf3106c9695d21a1e91fdf84c854e9fb557
+size 42818
diff --git a/marked/T/T-REC-T.126-200708-I_PDF-E/9ba75f891de20483c291538e38701d96_img.jpg b/marked/T/T-REC-T.126-200708-I_PDF-E/9ba75f891de20483c291538e38701d96_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..557f6ac143f8ba7d6760ec1db90734bfed97b87a
--- /dev/null
+++ b/marked/T/T-REC-T.126-200708-I_PDF-E/9ba75f891de20483c291538e38701d96_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:17095fa4c43caca80ff7fe61b208cb7a665ccca872b2b6ec434f0de5541773ed
+size 40707
diff --git a/marked/T/T-REC-T.126-200708-I_PDF-E/e8ba5d4a3a22e24e44f7935ea26afcb0_img.jpg b/marked/T/T-REC-T.126-200708-I_PDF-E/e8ba5d4a3a22e24e44f7935ea26afcb0_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..d5a35041124e73f88d6638cd17f42a2eb4f6781a
--- /dev/null
+++ b/marked/T/T-REC-T.126-200708-I_PDF-E/e8ba5d4a3a22e24e44f7935ea26afcb0_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:8f24b214263bab4142643453a604fb5196f9397e2500c675cde79d53ce5e5d8e
+size 3645
diff --git a/marked/T/T-REC-T.134-199802-I_PDF-E/raw.md b/marked/T/T-REC-T.134-199802-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..f56d6f3efe7705d43229f8b3350d3f93588e3715
--- /dev/null
+++ b/marked/T/T-REC-T.134-199802-I_PDF-E/raw.md
@@ -0,0 +1,553 @@
+
+
+![ITU logo: a globe with the letters ITU inside, crossed by a lightning bolt.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg)
+
+ITU logo: a globe with the letters ITU inside, crossed by a lightning bolt.
+
+INTERNATIONAL TELECOMMUNICATION UNION
+
+# ITU-T
+
+TELECOMMUNICATION  
+STANDARDIZATION SECTOR  
+OF ITU
+
+# T.134
+
+(02/98)
+
+SERIES T: TERMINALS FOR TELEMATIC SERVICES
+
+---
+
+# **Text chat application entity**
+
+ITU-T Recommendation T.134
+
+(Previously CCITT Recommendation)
+
+---
+
+# ITU-T T-SERIES RECOMMENDATIONS **TERMINALS FOR TELEMATIC SERVICES**
+
+![A large empty rectangular box with a double border.](c803f6f6e2c49429d2951832bd0f208d_img.jpg)
+
+A large empty rectangular box with a double border, likely intended for a diagram or additional text related to the terminal services.
+
+A large empty rectangular box with a double border.
+
+*For further details, please refer to ITU-T List of Recommendations.*
+
+## **ITU-T RECOMMENDATION T.134**
+
+# **TEXT CHAT APPLICATION ENTITY**
+
+## **Summary**
+
+This Recommendation defines a protocol that supports multipoint text conversation.
+
+The T.134 protocol supports multipoint conversation in text by allowing text entered at one site to be advertised within a session to other sites. It enables simple real time text conversation between terminal users.
+
+The text conversation presentation protocol in Recommendation T.140 is used in the text chatting application.
+
+Recommendation T.134 uses services provided by Recommendations T.122 (MCS) and T.124 (GCC) also in their light profile defined in Annex C/T.120.
+
+The Chat protocol is intended to be possible to combine with other data services as well as with video and audio in audiovisual services.
+
+## **Source**
+
+ITU-T Recommendation T.134 was prepared by ITU-T Study Group 16 (1997-2000) and was approved under the WTSC Resolution No. 1 procedure on the 6th of February 1998.
+
+## FOREWORD
+
+ITU (International Telecommunication Union) is the United Nations Specialized Agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the ITU. The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis.
+
+The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics.
+
+The approval of Recommendations by the Members of the ITU-T is covered by the procedure laid down in WTSC Resolution No. 1.
+
+In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC.
+
+## NOTE
+
+In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+## INTELLECTUAL PROPERTY RIGHTS
+
+The ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. The ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process.
+
+As of the date of approval of this Recommendation, the ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementors are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database.
+
+© ITU 1998
+
+All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU.
+
+# CONTENTS
+
+|                                                  | <b>Page</b> |
+|--------------------------------------------------|-------------|
+| 1 Scope.....                                     | 1           |
+| 2 Normative references .....                     | 2           |
+| 3 Definitions .....                              | 2           |
+| 4 Abbreviations.....                             | 3           |
+| 5 Overview.....                                  | 3           |
+| 5.1 CHAT concepts.....                           | 3           |
+| 5.1.1 Text and control.....                      | 4           |
+| 6 Use of MCS .....                               | 4           |
+| 6.1 MCS channel usage.....                       | 5           |
+| 6.2 Use of MCS data services .....               | 5           |
+| 7 Use of GCC.....                                | 5           |
+| 8 Protocol specification .....                   | 6           |
+| 8.1 CHAT sessions .....                          | 6           |
+| 8.2 Capabilities .....                           | 6           |
+| 8.3 CHATPDU formats .....                        | 6           |
+| 8.4 CHATE activation .....                       | 6           |
+| 8.5 Response to long delays or high loads .....  | 6           |
+| 8.6 Text and presentation control entry .....    | 6           |
+| 8.7 Text and presentation control reception..... | 7           |
+| 9 CHATPDU definitions .....                      | 7           |
+| 9.1 ASN.1 definition.....                        | 7           |
+| Annex A – Static channel ID assignments.....     | 8           |
+| Annex B – Object Identifier assignments .....    | 9           |
+| Appendix I – Informative values.....             | 9           |
+
+
+
+## Recommendation T.134
+
+# TEXT CHAT APPLICATION ENTITY
+
+(Geneva, 1998)
+
+# 1 Scope
+
+This Recommendation defines a protocol that supports multipoint text conversation, commonly known as chatting. It uses services provided by Recommendations T.122 (MCS) and T.124 (GCC) also in their light profile specified by Annex C/T.120.
+
+Figure 1 presents an overview of the scope of this Recommendation and its relationship to the other elements of the T.120 framework within a single node.
+
+![Figure 1/T.134 – Scope of this Recommendation. A block diagram showing the architecture of the T.120 framework. At the top is the 'User Application' (Using Recommendation T.140 presentation level chat protocol). Below it is the 'T.120 Application Protocol Recommendations' box, which contains the 'T.134 (CHAT) Application Protocol Entity'. To the right is the 'Node Controller'. Below these is the 'T.120 Infrastructure Recommendations' box, which contains the 'Generic Conference Control (GCC) T.124', the 'Multipoint Communication Service (MCS) T.122/T.125', and the 'Network Specific Transport Protocols T.123'. Arrows indicate the flow of data and control between these components.](0236eff05bcb8f3a343ea7933aaa306b_img.jpg)
+
+```
+graph TD
+    UA["User Application  
+(Using Recommendation T.140 presentation level chat protocol)"]
+    NCE["T.134 (CHAT)  
+Application Protocol Entity"]
+    NCR["Node Controller"]
+    GCC["Generic Conference Control (GCC)  
+T.124"]
+    MCS["Multipoint Communication Service (MCS)  
+T.122/T.125"]
+    NSTP["Network Specific Transport Protocols  
+T.123"]
+
+    UA <--> NCE
+    NCE <--> GCC
+    NCR <--> GCC
+    GCC <--> MCS
+    MCS <--> NSTP
+```
+
+The diagram illustrates the scope of Recommendation T.134 within the T.120 framework. It shows the following components and their interactions:
+
+- User Application**: (Using Recommendation T.140 presentation level chat protocol)
+- T.120 Application Protocol Recommendations**: Contains the **T.134 (CHAT) Application Protocol Entity**.
+- Node Controller**
+- T.120 Infrastructure Recommendations showing the place of this Recommendation**: Contains the **Generic Conference Control (GCC) T.124**, the **Multipoint Communication Service (MCS) T.122/T.125**, and the **Network Specific Transport Protocols T.123**.
+
+Arrows indicate the flow of data and control between these components.
+
+Figure 1/T.134 – Scope of this Recommendation. A block diagram showing the architecture of the T.120 framework. At the top is the 'User Application' (Using Recommendation T.140 presentation level chat protocol). Below it is the 'T.120 Application Protocol Recommendations' box, which contains the 'T.134 (CHAT) Application Protocol Entity'. To the right is the 'Node Controller'. Below these is the 'T.120 Infrastructure Recommendations' box, which contains the 'Generic Conference Control (GCC) T.124', the 'Multipoint Communication Service (MCS) T.122/T.125', and the 'Network Specific Transport Protocols T.123'. Arrows indicate the flow of data and control between these components.
+
+T1604150-97
+
+Figure 1/T.134 – Scope of this Recommendation
+
+# 2 Normative references
+
+The following ITU Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; all users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published.
+
+- ITU-T Recommendation F.710 (1991), *General principles for audiographic conference service*.
+- ITU-T Recommendation T.120 (1996), *Data protocols for multimedia conferencing*.
+- ITU-T Recommendation T.121 (1996), *Generic application template*.
+- ITU-T Recommendation T.122 (1993), *Multipoint communication service for audiographics and audiovisual conferencing service definition*.
+- ITU-T Recommendation T.123 (1996), *Network specific data protocol stacks for multimedia conferencing*.
+- ITU-T Recommendation T.124 (1995), *Generic Conference Control*.
+- ITU-T Recommendation T.125 (1994), *Multipoint communication service protocol specification*.
+- ITU-T Recommendation T.140 (1998), *Text conversation protocol for multimedia application*.
+- ITU-T Recommendation X.680 (1997) | ISO/IEC 8824-1:1998, *Information technology – Abstract Syntax Notation One (ASN.1) – Specification of basic notation*.
+- ITU-T Recommendation X.691 (1997) | ISO/IEC 8825-2:1998, *Information technology – ASN.1 encoding rules – Specification of Packed Encoding Rules (PER)*.
+- ISO/IEC 10646-1:1993 (including Amendments 1996), *Information technology – Universal Multiple-Octet Coded Character Set (UCS) – Part 1: Architecture and Basic Multilingual Plane*.
+
+# 3 Definitions
+
+This Recommendation defines the following terms:
+
+**3.1 Text Chat (CHAT):** A process that enables text entered on one terminal to be displayed at once to the user on that terminal and on one or more other terminals participating in a chat session.
+
+**3.2 Chat Protocol Entity (CHATE):** An Application Protocol Entity that interacts with a user application above and with the local MCS (Multipoint Communication Service) and local GCC (Generic Conference Control) providers below to implement application sharing. Data is exchanged between peer CHATEs using CHATPDUs (Chat Protocol Data Units).
+
+**3.3 handle:** A CHAT session-wide unique number used to identify an addressable item.
+
+**3.4 standard capability:** The capability is defined within the scope of this Recommendation but is not required for all CHATE implementations. Note that all standard capabilities must be negotiated before use.
+
+**3.5 unicode:** Text string format with multilingual capabilities as defined in ISO/IEC 10646-1.
+
+**3.6 window:** A rectangular area on the terminal display corresponding to a user interface display area managed by the terminal window manager.
+
+**3.7 Chat Channel (CHAT-CHANNEL):** A T.120 channel dedicated for use by the text conversation protocol.
+
+# 4 Abbreviations
+
+This Recommendation uses the following abbreviations:
+
+|         |                                                |
+|---------|------------------------------------------------|
+| CHATE   | Text Chat Protocol Entity                      |
+| CHATPDU | Chat Protocol Data Unit                        |
+| GCC     | Generic Conference Control                     |
+| IEC     | International Electrotechnical Commission      |
+| ISO     | International Organization for Standardization |
+| ITU     | International Telecommunication Union          |
+| MCS     | Multipoint Communication Service               |
+
+# 5 Overview
+
+The CHAT protocol enables multipoint text conversation in real time by allowing text entered at one site to be displayed within a session at other sites. Each site can enter text in the session. Exchange of text is maintained on a character-by-character or close to character-by-character basis in order to give the session participants an opportunity to exercise a natural conversation in text. The text and control exchange is done according to Recommendation T.140.
+
+A CHAT session consists of one or more CHATE entities which cooperate via the CHAT protocol to distribute entered text within the session. The CHAT protocol defines interactions between CHATEs. It does not define interactions between a CHATE and the operating system or input and output devices on the local terminal.
+
+## 5.1 CHAT concepts
+
+Figure 2 shows an example collection of CHATEs within a CHAT session.
+
+![Diagram showing three CHATE entities (A, B, and C) connected in a multipoint configuration. CHATE A is at the top, CHATE B is at the bottom left, and CHATE C is at the bottom right. A curved arrow points from A to C, and another curved arrow points from C to A. A horizontal double-headed arrow connects B and C, indicating bidirectional communication between them.](99bae07626f60f9ede10e2e387ef7051_img.jpg)
+
+T1604160-97
+
+Diagram showing three CHATE entities (A, B, and C) connected in a multipoint configuration. CHATE A is at the top, CHATE B is at the bottom left, and CHATE C is at the bottom right. A curved arrow points from A to C, and another curved arrow points from C to A. A horizontal double-headed arrow connects B and C, indicating bidirectional communication between them.
+
+**Figure 2/T.134**
+
+- CHATE A and B both enters text into the CHAT session and displays text received from other CHATEs.
+
+- The MCS provider in the mode with CHATE C acts as an MCU, distributing the CHATPDUs among the CHATEs.
+
+### 5.1.1 Text and control
+
+When text is entered or a control action taken, then the CHATE constructs a suitable chat entry for the other CHATEs.
+
+The CHAT chat entry consists of interleaved text entries and presentation control actions as specified in Recommendation T.140.
+
+# 6 Use of MCS
+
+All T.134 communication shall be through MCS as specified in Recommendation T.122 and keeping within the subset defined by Annex C/T.120. This clause details specific use of MCS services, channel allocation and data priorities. This Recommendation complies with the mechanisms described in Recommendation T.121 regarding proper operations for standard base sessions, and the registration session.
+
+A CHATE uses the MCS service primitives described in Table 6-1 to attach and detach from a domain, join and leave the CHAT channel, and send and receive CHATPDUs.
+
+**Table 6-1/T.134 – MCS primitives needed by a CHATE**
+
+| <b>MCS primitive</b>  | <b>Description</b>                                                                                                                                                                                                                                                                                                          |
+|-----------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| MCS-ATTACH-USER       | Creates an MCS attachment through an MCS SAP to a domain hosted by the MCS provider. A result is confirmed to the requester. If the request is accepted, a user ID is assigned.                                                                                                                                             |
+| MCS-DETACH-USER       | Deletes an MCS attachment that was created previously by invocation of MCS-ATTACH-USER. This primitive may be requested by a user or initiated by a provider. It delivers an indication at every other MCS attachment to the same domain. If provider initiated, an indication is also delivered at the deleted attachment. |
+| MCS-CHANNEL-JOIN      | Used by an application client to join an appropriate channel whose use is defined by the application. This is a prerequisite for receiving data sent to the channel.                                                                                                                                                        |
+| MCS-CHANNEL-LEAVE     | Used by an application client to leave a previously joined channel and thus stop receiving data sent to that channel. The primitive may be user initiated (request only) or provider initiated (indication to affected user only).                                                                                          |
+| MCS-UNIFORM-SEND-DATA | Used to transmit data to other members of a domain. If the sender is a member of the destination channel, it will not receive its own data indications. However, it will receive data indications from other sources addressed to that channel.                                                                             |
+
+MCS request primitives are directed from the CHATE to the MCS provider, while indication primitives are directed from the MCS provider towards the CHATE. Additional detail on the MCS primitives described above can be found in Recommendation T.122 (Multipoint communication service for audiographics and audiovisual conferencing service definition).
+
+## 6.1 MCS channel usage
+
+Table 6-2 describes MCS channel usage for CHATE sessions of the types defined in Recommendation T.121. In the case of a Standard Base Session (see Recommendation T.121) which uses the CHAT protocol, the Channel IDs shown in Table 6-2 shall be used (symbolic IDs shown). For all other session types, the Application Registry Resource IDs shown in the table shall be used for allocating dynamic channels. The given Resource IDs shall be encoded as three-octet T.50 text strings using the characters shown in quotes in Table 6-2.
+
+**Table 6-2/T.134 – Description of CHAT channels**
+
+| <b>Mnemonic</b> | <b>Channel IDs for Static Channel</b> | <b>Application Registry Resource IDs for Dynamic Channels</b> | <b>Description</b>                                                              |
+|-----------------|---------------------------------------|---------------------------------------------------------------|---------------------------------------------------------------------------------|
+| CHAT-CHANNEL    | CHAT-CHANNEL-0                        | "T140"<br>(to be defined)                                     | This channel bears all CHATPDUs to be broadcast to all peer CHATEs in a domain. |
+
+## 6.2 Use of MCS data services
+
+Table 6-3 lists the use of the MCS data service MCS-UNIFORM-SEND-DATA for the CHATPDU. This table includes the channel over which the data is sent and the data priority at which the data is sent.
+
+- The CHAT protocol uses only the Medium MCS priority.
+
+The CHATPDUs specified in this Recommendation are placed in the Data parameter of the MCS-UNIFORM-SEND-DATA primitive. The CHATPDUs are packed into the sequence of octets that form the Data parameter such that the leading bit is placed in the most significant bit of each octet, and filled toward the least significant bit of the octet.
+
+**Table 6-3/T.134 – Use of MCS data primitives for CHATPDUs**
+
+| <b>CHATPDU</b> | <b>Channel</b> | <b>Priority</b> |
+|----------------|----------------|-----------------|
+| ChatentryPDU   | CHAT-CHANNEL   | Medium          |
+
+# 7 Use of GCC
+
+The CHAT protocol may use the procedures defined for a Registration Session and a Standard Base Session in the manner specified in Recommendation T.121 and shall use as its Application Protocol Key the Object Identifier defined in Annex B.
+
+All CHATEs compliant with this Recommendation shall first enrol actively or inactively in the Registration Session using the procedures defined in Recommendation T.121 and shall stay enrolled for as long as support for the CHAT protocol is to be indicated.
+
+CHATEs may enrol in a Public Session or Private Session at their discretion using the procedures defined in Recommendation T.121.
+
+When a session is in conducted mode, a CHATE may be restricted from sending data, depending on the GCC conducted-mode permission mechanism. If the node is given GCC conducted-mode permission, then a CHATE may send any type of ChatPDU. If the node is not given GCC conducted-mode permission, then a CHATE shall not send any type of ChatPDU.
+
+# **8 Protocol specification**
+
+## **8.1 CHAT sessions**
+
+A CHAT session consists of one or more CHATEs enrolled within a conference as described in clause 7. CHATEs may join or leave the CHAT session at any time.
+
+## **8.2 Capabilities**
+
+There are no capabilities to negotiate for this protocol.
+
+## **8.3 CHATPDU formats**
+
+The CHATPDUs contain data from the T.140 protocol.
+
+One CHATPDU can contain one or more entries of text and control items from the T.140 protocol.
+
+**Table 8-1/T.134 – ChatData**
+
+| <b>Parameter</b>  | <b>Description</b>                                         |
+|-------------------|------------------------------------------------------------|
+| <b>ChatString</b> | One or more text and control items from the T.140 protocol |
+
+A ChatPDU can contain non-standard information using the chatNonStandardPDU choice. This uses the H221NonStandardIdentifier to allow an implementation to use non-standard information without conflicting with any other implementation's non-standard information. If a terminal receives a ChatNonStandardPDU it doesn't understand, it shall ignore the PDU.
+
+## **8.4 CHATE activation**
+
+In the CHAT protocol, CHATE activation shall be performed according to Recommendation T.121.
+
+A CHATE shall use the last roster instance number supplied by a GCC-APPLICATION-ROSTER-REPORT indication on the Standard Base Session that contains both itself and other CHATEs enrolled active.
+
+## **8.5 Response to long delays or high loads**
+
+If long delays are experienced or other high load indications, one reason can be that the total volume of CHAT data transmission in a large conference is high. For such cases, a CHATE may process CHAT data such that the volume of the transmission is reduced by buffering text for a longer period than normally done (reduces mean protocol overhead). The buffering timer is a local configuration value that should not exceed the limit documented in Appendix I. A value of zero indicates that no buffering is applied. In low bandwidth applications it may be accepted to configure constantly for the maximum buffering delay.
+
+## **8.6 Text and presentation control entry**
+
+The application enters text and presentation control elements according to Recommendation T.140 to CHATE for distribution.
+
+The entry should be inserted in a ChatentryPDU. If no buffering timer is specified, each entry from the application is sent with a ChatentryPDU.
+
+If a buffering timer is specified, entries are stored sequentially in one ChatentryPDU and sending initiated after the buffer timer has expired. The buffering timer is started when the first entry is stored in the ChatentryPDU.
+
+The buffering timer is a local constant within the CHATE. See Appendix I.
+
+## 8.7 Text and presentation control reception
+
+On reception of a ChatentryPDU, the CHATE extracts its text and presentation control elements and other parameters and submits it to the application for action (commonly as specified in Recommendation T.140).
+
+# 9 CHATPDU definitions
+
+The structure of CHATPDUs for the CHAT protocol are specified as follows using the notation ASN.1 of Recommendation X.680.
+
+The CHATPDUs shall be encoded and placed in the data field of MCS-UNIFORM-SEND-DATA primitives, with the bit string generated by the encoding placed in the GENERAL STRING used by MCS in the order such that for each octet, the leading bit is placed in the most significant bit position and the trailing bit is placed in the least significant bit position.
+
+## 9.1 ASN.1 definition
+
+```
+--|||
+--|||
+```
+
+```
+--
+```
+
+```
+-- Begin CHAT Definitions
+```
+
+```
+--
+```
+
+```
+-- The following base mode ASN.1 definitions are encoded using the BASIC
+```
+
+```
+-- ALIGNED variant of the Packed Encoding Rules of ITU-T Recommendation
+```
+
+```
+-- X.691.
+```
+
+```
+--
+```
+
+```
+--|||
+--|||
+```
+
+**CHAT-PROTOCOL DEFINITIONS AUTOMATIC TAGS ::=**
+
+**BEGIN**
+
+```
+-- NOTE: =====
+```
+
+```
+-- NOTE: All abstract types defined shall be exported
+```
+
+```
+-- NOTE: =====
+```
+
+```
+-- H221NonStandardIdentifier
+```
+
+```
+-- Used to specify non-standard objects using H.221 numbering.
+```
+
+```
+-- The first four octets shall designate country code and
+```
+
+```
+-- manufacturer code, assigned as specified in
+```
+
+```
+-- Annex A/H.221 for NS-cap and NS-comm.
+```
+
+**H221NonStandardIdentifier ::= OCTET STRING (SIZE (4..255))**
+
+**Key ::= CHOICE** -- Identifier of a standard or non-standard object
+
+```
+{
+  object      OBJECT IDENTIFIER,
+  h221NonStandard H221NonStandardIdentifier
+}
+```
+
+```
+
+-- NonStandardParameter
+-- Used to specify non-standard parameters. This includes a
+-- data field which may be used to fill in parameter values
+-- of the type indicated by the NonStandardIdentifier
+NonStandardParameter ::= SEQUENCE
+{
+    key          Key,
+    value        OCTET STRING OPTIONAL
+}
+
+ChatString ::= GeneralString (SIZE (0..255)) -- Chat Protocol String
+
+--|||||
+--|||||
+--
+--          Begin CHATPDU Definitions
+--
+--|||||
+--|||||
+ChatentryPDU ::= SEQUENCE
+{
+    chatString          ChatString,
+    ...
+}
+
+ChatNonStandardPDU ::= SEQUENCE
+{
+    nonStandardTransaction    NonStandardParameter,
+    ...
+}
+
+ChatPDU ::= CHOICE
+{
+    chatentryPDU          ChatentryPDU,
+    chatNonStandardPDU    ChatNonStandardPDU,
+    ...
+}
+
+--|||||
+--|||||
+--
+--          End CHAT Definitions
+--
+--|||||
+--|||||
+
+END
+
+```
+
+# ANNEX A
+
+## Static channel ID assignments
+
+Table A.1 lists the numerical assignment of static channel IDs for the static channels allocated for use by this Recommendation. The numerical assignment of static channel IDs is intended to be centralized in Recommendation T.120, but is included here until T.120 is completed.
+
+**Table A.1/T.134 – Static channel ID assignments**
+
+| Symbolic Name  | Channel ID |
+|----------------|------------|
+| CHAT-CHANNEL-0 | 12         |
+
+## ANNEX B
+
+## Object Identifier assignments
+
+Table B.1 lists the assignment of Object Identifiers defined for use by this Recommendation.
+
+**Table B.1/T.134**
+
+| Object Identifier Value                    | Description                                                                    |
+|--------------------------------------------|--------------------------------------------------------------------------------|
+| {itu-t recommendation t 134 version (0) 1} | This Object Identifier is used to indicate the version of this Recommendation. |
+
+# APPENDIX I
+
+## Informative values
+
+This appendix provides suggested values for various values described within the main body of this Recommendation, based on experience with application sharing on a number of terminal types. These values are not mandatory and the actual values used by a specific CHATE are left to the discretion of the implementer.
+
+### Maximum buffering timer
+
+The maximum time a character should stay buffered before transmission should be kept low in order to let the users perceive the flow of the text without disturbing delays. However, buffering can save bandwidth by decreasing mean protocol overhead per transmitted character.
+
+A maximum buffering timer of 500 ms is recommended.
+
+
+
+# ITU-T RECOMMENDATIONS SERIES
+
+|                 |                                                                                                                                |
+|-----------------|--------------------------------------------------------------------------------------------------------------------------------|
+| Series A        | Organization of the work of the ITU-T                                                                                          |
+| Series B        | Means of expression: definitions, symbols, classification                                                                      |
+| Series C        | General telecommunication statistics                                                                                           |
+| Series D        | General tariff principles                                                                                                      |
+| Series E        | Overall network operation, telephone service, service operation and human factors                                              |
+| Series F        | Non-telephone telecommunication services                                                                                       |
+| Series G        | Transmission systems and media, digital systems and networks                                                                   |
+| Series H        | Audiovisual and multimedia systems                                                                                             |
+| Series I        | Integrated services digital network                                                                                            |
+| Series J        | Transmission of television, sound programme and other multimedia signals                                                       |
+| Series K        | Protection against interference                                                                                                |
+| Series L        | Construction, installation and protection of cables and other elements of outside plant                                        |
+| Series M        | TMN and network maintenance: international transmission systems, telephone circuits, telegraphy, facsimile and leased circuits |
+| Series N        | Maintenance: international sound programme and television transmission circuits                                                |
+| Series O        | Specifications of measuring equipment                                                                                          |
+| Series P        | Telephone transmission quality, telephone installations, local line networks                                                   |
+| Series Q        | Switching and signalling                                                                                                       |
+| Series R        | Telegraph transmission                                                                                                         |
+| Series S        | Telegraph services terminal equipment                                                                                          |
+| <b>Series T</b> | <b>Terminals for telematic services</b>                                                                                        |
+| Series U        | Telegraph switching                                                                                                            |
+| Series V        | Data communication over the telephone network                                                                                  |
+| Series X        | Data networks and open system communications                                                                                   |
+| Series Y        | Global information infrastructure                                                                                              |
+| Series Z        | Programming languages                                                                                                          |
\ No newline at end of file
diff --git a/marked/T/T-REC-T.140-199802-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/T/T-REC-T.140-199802-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..6c3b2397f6e41047d55e53ae3132463cb25a354e
--- /dev/null
+++ b/marked/T/T-REC-T.140-199802-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:a4fcfd496b629234712fa52dc90c9f6694f3694af865f6a7562c928c2fa89cb7
+size 8191
diff --git a/marked/T/T-REC-T.140-199802-I_PDF-E/c803f6f6e2c49429d2951832bd0f208d_img.jpg b/marked/T/T-REC-T.140-199802-I_PDF-E/c803f6f6e2c49429d2951832bd0f208d_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..b6406f41edccbdb7ee24865ee4d0095f76348dce
--- /dev/null
+++ b/marked/T/T-REC-T.140-199802-I_PDF-E/c803f6f6e2c49429d2951832bd0f208d_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:62fa14934a0314a178423207cc0223cb6bbe600484e8700326783190c6789eeb
+size 10343
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/0317016f1967843fe2643d09bd7bee9d_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/0317016f1967843fe2643d09bd7bee9d_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..20a3c6a6c0796bd3604405767c02eef12065dba1
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/0317016f1967843fe2643d09bd7bee9d_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:1bb895a7b46aa41471c4e39f8d59c56a7ea71bce122831aef2bd766b5a7af300
+size 50182
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/042af54276c75e7b7b48a3af1f0a84e5_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/042af54276c75e7b7b48a3af1f0a84e5_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..f0b43b79894bb1cc2053e3e6af0f795bf8972324
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/042af54276c75e7b7b48a3af1f0a84e5_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:8bb26c6c7bb29f1f846184e334e756f23cc18aa6ff80f93cac4e5cad449d4742
+size 13088
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/08246879b7e3340f5c7af67ca43e48ff_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/08246879b7e3340f5c7af67ca43e48ff_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..977658edc64ef179f9b31a473164f2b189da389b
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/08246879b7e3340f5c7af67ca43e48ff_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:49eda89240c0276d899b6855b2898fec053d29aa4f745bc6d2d8057ab9219ce9
+size 48223
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/13dbd16a58861b335d8e10047ae8e524_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/13dbd16a58861b335d8e10047ae8e524_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..ea41eb248443fc0797a9e6bbf5ad5253e4a4fe6b
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/13dbd16a58861b335d8e10047ae8e524_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:88c61eddce79b72d6d08d91fb902a142652ceb734148168a7456d7b9fe992328
+size 14606
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/1da51f3c529c931159de791528434512_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/1da51f3c529c931159de791528434512_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..79f0ac1451925d7f9b74d4b35cb6ad0926ff21e5
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/1da51f3c529c931159de791528434512_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:cd6c866b1e6ed9413512478790686152963979eb96f2535dfc72e0d0833c21fe
+size 35667
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/25560b45ff748b9fc5d85aa004d18aa2_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/25560b45ff748b9fc5d85aa004d18aa2_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..97e031fed81a0be09f569459d53ab733eeb0c419
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/25560b45ff748b9fc5d85aa004d18aa2_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:b789abb8b88fd72770a2910fefe17ff6859e79d23a4bd532441747fc93460804
+size 17060
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..3a58f68885c03bc2fb95bb409d68f7f55947475f
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:97adcbdebb3326a1af9817c0266d6c1cef088a8f97dc377b1e5fd01e721d14f7
+size 8269
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/2ffdb0621c4918479cd1ac7a531b1b92_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/2ffdb0621c4918479cd1ac7a531b1b92_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..c9bee2639fa0a098ccae476f95b4e48bd7215024
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/2ffdb0621c4918479cd1ac7a531b1b92_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:7d0a85d89b3ffa6443be15ebaf3eef354c1736c227c63d3357e23789dde23426
+size 74688
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/3252037b597c9317aced0feed4cb5af0_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/3252037b597c9317aced0feed4cb5af0_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..fe9a4918c7d139a0e76fcc750589e03fbc05a115
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/3252037b597c9317aced0feed4cb5af0_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:8d2cd5091cee4fe46ea4932326076aff633b8a26bc95bc79129c9300d838353c
+size 35167
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/32d36dfe7dc75b7c63f8edf0f28e4009_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/32d36dfe7dc75b7c63f8edf0f28e4009_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..bd3fd30d40ac2b642ba9fbcbcccb033107313b49
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/32d36dfe7dc75b7c63f8edf0f28e4009_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:3ea796ee210c626ed714e32cdf66482159f9f7c3b4606c237d12755706424d34
+size 74052
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/3481cde1adf61b0452dd6489dada6d6a_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/3481cde1adf61b0452dd6489dada6d6a_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..0895507b9d6aac6ec8e34aa781e2a5a05c9d362d
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/3481cde1adf61b0452dd6489dada6d6a_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:2e9b54047d3592bf02698fdc8caf363b858eeebbd6380cac56e303ad18d7ec28
+size 78903
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/35ddc8b19bd31dedba7ba2d696f43bd0_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/35ddc8b19bd31dedba7ba2d696f43bd0_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..303ab0fcc6765976e02e020f974b07222a1dce2a
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/35ddc8b19bd31dedba7ba2d696f43bd0_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:fbfd1c6a8a56fa40a1a29b730f2358022979c9368b104093d03313803661cec6
+size 82700
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/367378559e35017a5e1a6f5c30798c5a_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/367378559e35017a5e1a6f5c30798c5a_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..12ac1b029ebcfb4f01fd870e4894900144cfaa37
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/367378559e35017a5e1a6f5c30798c5a_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:e7d99b0e6e4899578b4b83e082aa2c05a6cfa40774403a9c0e6efdb894f18824
+size 22445
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/3766b291e69420b0437ae278b057b5ee_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/3766b291e69420b0437ae278b057b5ee_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..758ed117ede35d6788f36e6bdf7ca85cf8d15021
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/3766b291e69420b0437ae278b057b5ee_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:cdac4be6e4ee405dbf5d6e66c2cef5c9dd19ab3482ac0885ed2b1800c6096528
+size 65751
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/3a006a7c9c9934695f0fc731344eff8a_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/3a006a7c9c9934695f0fc731344eff8a_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..84b6a0ca1b3bfd0da6a0459f6707a97c08f4b065
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/3a006a7c9c9934695f0fc731344eff8a_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:02dc9f7a799763cf2d7b8bf02f5679b65e60c883ffc87077ca6ad2bee5bde4f0
+size 88187
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/3bf1696c3034743b5ab07a0b5e398347_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/3bf1696c3034743b5ab07a0b5e398347_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..cd59496dd98e373d1f9b105192c02667f62cc21c
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/3bf1696c3034743b5ab07a0b5e398347_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:41f5750680cf33e52306492f9f5f594d849fe20aef50929f5ce4f91fdbc90a76
+size 34908
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/3d46409f8d0190e611a910ff27f8ec07_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/3d46409f8d0190e611a910ff27f8ec07_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..2247f04c086f4fdac4bea8ff7bfe0f85991fff45
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/3d46409f8d0190e611a910ff27f8ec07_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:3eb439e7383099240ba72624776b619a44c257180b1089eb254e5aa2b2a5bce3
+size 27623
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/3df1d2bf049815d761b03fb9cc2bc7ed_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/3df1d2bf049815d761b03fb9cc2bc7ed_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..8253516a76225f115611690fa354b0f0105d28f4
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/3df1d2bf049815d761b03fb9cc2bc7ed_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:a11bacb20992718a9fcb21da5bc58df808adbea5ed02a86871f8eeb71f24642d
+size 29434
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/3f09464f0a8ac9446981a53f9b78df2c_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/3f09464f0a8ac9446981a53f9b78df2c_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..807f2ee79ea08eae607701c01039ffcf45f07b31
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/3f09464f0a8ac9446981a53f9b78df2c_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:51bbd5e9c0edd09d1649928d70806541243f7aa85eb8ea9fc5025160cab3dd68
+size 7729
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/42ab2aee8612b8eb35a8e9597d6c1449_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/42ab2aee8612b8eb35a8e9597d6c1449_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..aee19e0925c38e74ee9a7f054f540f32ca0da7c5
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/42ab2aee8612b8eb35a8e9597d6c1449_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:7bda496388561b9044661a715024a6d8fe1d39175be0b29c6288c9d0ccdb6d23
+size 45972
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/4456970fc44aef8325e9e5c4efe2fcc9_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/4456970fc44aef8325e9e5c4efe2fcc9_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..b56557b7a9289b950b8a63e87da01d157a52211a
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/4456970fc44aef8325e9e5c4efe2fcc9_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:87a673df394060c23311b4745d9f74c4d9ede197f867ab14de410c4c8f14e7e7
+size 63618
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/4801e73fa692059f2ca78196e6e907be_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/4801e73fa692059f2ca78196e6e907be_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..a2a1252c5e40e76622d60051afeebbec7ef2f9e7
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/4801e73fa692059f2ca78196e6e907be_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:e2b62494310d2be35ebf60a914576e51b774a66b2cf4e3d2f151ffcb257343e0
+size 20024
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/48adb97a6a4a14b039450192f25cc1e0_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/48adb97a6a4a14b039450192f25cc1e0_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..8acc972500598ad683a7340e5a87e18672aa5474
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/48adb97a6a4a14b039450192f25cc1e0_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:c132fc6fda5f532c072dd53a8efa0093eb7816e991ddefc2a744375b4b2b43e7
+size 42688
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/50ef8602c7c9edd2da0e2133e772c2a2_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/50ef8602c7c9edd2da0e2133e772c2a2_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..35e91349de4072cbc4b4f6769f2dee5cd7ea51aa
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/50ef8602c7c9edd2da0e2133e772c2a2_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:bf32943bb52d939911a5f07d59333033b60c6ddc3c3984e4eba7db611de2208b
+size 40017
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/5414f65867392f05ba0063b208eeb5e1_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/5414f65867392f05ba0063b208eeb5e1_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..666a8a81196791734564bb091fdeafdd4a38587f
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/5414f65867392f05ba0063b208eeb5e1_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:8a490348a6f1327a507b4121f4f665d434f7b9e0281cf9592a53f73f94467219
+size 40323
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/56a42b3c4e1a79a71c8f27aa03b78b84_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/56a42b3c4e1a79a71c8f27aa03b78b84_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..4948641c1a378f57e4d1fd3b345993f56299c0d0
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/56a42b3c4e1a79a71c8f27aa03b78b84_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:874c6de6c2c6fc7cce36ac8f1fb12ce25bfe4c7f7eea5d6edc536ddbee1a4470
+size 43553
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/57939c16065211317c5442cf2a4009e0_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/57939c16065211317c5442cf2a4009e0_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..62198fe855bd6d00fb0a6257d5cae2de1646eb6c
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/57939c16065211317c5442cf2a4009e0_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:87eca5b7bc7e4764f73ad142ff8c4bbe4540736740ba71e23e4aaf5e0691237e
+size 16189
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/592f13acca3e6d5152dd4489f030d004_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/592f13acca3e6d5152dd4489f030d004_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..ff348c6aab4572be93b5169a4bfe0c9aa826ac48
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/592f13acca3e6d5152dd4489f030d004_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:e40e4a1989f3da3660a65ce44d2c33bc581ab93d1e7d67aa4ffa5c6590dbda29
+size 20188
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/5a01395925fc88802da68fb5ac0f31ff_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/5a01395925fc88802da68fb5ac0f31ff_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..135f2db6164ee06d58cc4b7571c2958a6e26fd8e
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/5a01395925fc88802da68fb5ac0f31ff_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:13549456897cf337326478a4448bb51f3ab083326b2ebb9d2d97a620e068959c
+size 17829
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/5f0cd37cd04eb79e50c13875b337ad29_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/5f0cd37cd04eb79e50c13875b337ad29_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..4cea63f0d2ab71c8166ce3b46955d0d637773b8c
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/5f0cd37cd04eb79e50c13875b337ad29_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:325e034eed9a928f1a900b965c7b381e20d73ac0b1712e1d201b3687bee1dd78
+size 62921
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/65b5e4a95d403df0ea5e8ff94f162a6a_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/65b5e4a95d403df0ea5e8ff94f162a6a_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..e33a14791aa31fbaa86f071479fab02c6337b947
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/65b5e4a95d403df0ea5e8ff94f162a6a_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:9078709f265cff8389ad4d5aac69d440ee676fed94bb05f0985e5145ebf1315d
+size 40760
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/66e89867f97592fd4bfab0e4f2b2054f_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/66e89867f97592fd4bfab0e4f2b2054f_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..b6b4131716fe507032db54f888385e8b0c9dafa5
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/66e89867f97592fd4bfab0e4f2b2054f_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:94aeaa837488c5cfba511d5473d009b3ed2556517b56ba6d5ed7271753c1a9b8
+size 47105
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/69a0bbfb9f60f00d25b9150cfa2204ab_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/69a0bbfb9f60f00d25b9150cfa2204ab_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..4a0846821cf0afc42a02d0c9865efdbff86d548e
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/69a0bbfb9f60f00d25b9150cfa2204ab_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:385db498f32a732e2d62d18af927a55a9e0c5fd38eb6cc401883b216d33b9cf6
+size 81381
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/6a993bfdf2e00cfad01c4d2188a75d86_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/6a993bfdf2e00cfad01c4d2188a75d86_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..563074555b1ccc3550f078bdfa25f912282916b5
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/6a993bfdf2e00cfad01c4d2188a75d86_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:74d41ffd8ab160cec4d6380d981eacf9099a7a41b3bfbbe5b8a3add3a4c91c74
+size 68582
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/7156cf400ef0e19f9d06a5d0549834a3_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/7156cf400ef0e19f9d06a5d0549834a3_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..cb07ee1bd8318fa3db8ab6696cd5242f41e26cf5
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/7156cf400ef0e19f9d06a5d0549834a3_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:f7f3bd86bb50ba974a0aaa061f208095da959aa818aff7b048d6dda3342e13a9
+size 31607
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/71b0a68b4dd64961465d2b0e790538de_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/71b0a68b4dd64961465d2b0e790538de_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..e52a9d490525eae791502f336253a7cbeeaf1b5c
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/71b0a68b4dd64961465d2b0e790538de_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:1eb85f9924599a6cbb1f9efc8643f53c018da580995e855d58d7b8be25536c3d
+size 38178
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/72d448a65347c51989171748789c7d4b_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/72d448a65347c51989171748789c7d4b_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..e7495cd429925291b2de25a993869a5d6f44c300
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/72d448a65347c51989171748789c7d4b_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:8f49435860de038ad905f0145c9a95e7940becd1d7045424771fd1577c50fb30
+size 25109
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/7e61b2e2506cc7e5d6e16ce9c9df25bb_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/7e61b2e2506cc7e5d6e16ce9c9df25bb_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..dd5b53ca81f1ce5753f99a329902b2888293928d
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/7e61b2e2506cc7e5d6e16ce9c9df25bb_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:9296093764a71af3d7595b26fa4ad0b4b7962202f1b99bdbdd5225600c20a776
+size 9280
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/834fb96b114b8fdc001625e1ae28e8b1_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/834fb96b114b8fdc001625e1ae28e8b1_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..7f556a2b222dc66e71198cce9a85b4501103faf6
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/834fb96b114b8fdc001625e1ae28e8b1_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:a87a1209688631d1e4bb0bcb5fadfae7e765991f51cf79d5d04134462268344e
+size 33387
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/8c5d620091865579706e00b6df247461_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/8c5d620091865579706e00b6df247461_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..d71cfa9598f8621d25c45e576bea20c9015e2f4d
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/8c5d620091865579706e00b6df247461_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:b1a4722a0ed5feceefee577147546e5a16ab42e131d4248027e275b633782311
+size 30652
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/8d66c9c295023a1380f9986d3663bb1e_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/8d66c9c295023a1380f9986d3663bb1e_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..457c38d8e4ef49193fe115cc84da8400a656ab04
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/8d66c9c295023a1380f9986d3663bb1e_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:22f4bc229725990ff061ebbcb40f3752e169411e9319388ec73e7dd5ec3724ad
+size 55715
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/909726977de6efd2d4df015198a2907b_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/909726977de6efd2d4df015198a2907b_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..6540d450b01405e2e6dabab74cd898261f031837
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/909726977de6efd2d4df015198a2907b_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:e7523c97103792186edbb62594c3f4f082a3bbfb4577a63e0a33c7bdb391720c
+size 19528
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/9687bd5e8b62cadba093b0d1b70536cd_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/9687bd5e8b62cadba093b0d1b70536cd_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..ee83630915e333b3b85da49581bcde9de15e8709
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/9687bd5e8b62cadba093b0d1b70536cd_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:394c9b5d02892b5cbfd4e2f1ce8286ea416949be34a78388e15973cd139f832b
+size 58444
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/9874e3ac6f14360133f8e1674f79824f_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/9874e3ac6f14360133f8e1674f79824f_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..3cbfa670e6edb665f0d3232532a509cb638ca8f2
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/9874e3ac6f14360133f8e1674f79824f_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:0570db5753fbcb1f9c90c71cb2e7a8ad26817cbf9ddf1d94b58d1cb81a44eba6
+size 32787
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/9c0aa353d4de54327351c9326f198756_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/9c0aa353d4de54327351c9326f198756_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..9c6dd60a4235ab17ceaabde367eb9664e1628b27
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/9c0aa353d4de54327351c9326f198756_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:ef5791e92d55a380e53247c06ef0aefc873c11e41d99554f47a14d66dba647c6
+size 57781
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/9d4fac3c0fc4ca80bbf01b4eeb71f255_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/9d4fac3c0fc4ca80bbf01b4eeb71f255_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..5c72308ec74a3c49b68b812ed3bc8996c07d9313
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/9d4fac3c0fc4ca80bbf01b4eeb71f255_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:2682ade85831e50eaf22e664464190388363b805b43694401e25197d176535a8
+size 87936
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/9ec7afb8bd1d2648de277cd79293d4c1_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/9ec7afb8bd1d2648de277cd79293d4c1_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..3b1471d86261f8705d79060ecdf71b679315365f
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/9ec7afb8bd1d2648de277cd79293d4c1_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:026a1598145465c28529d21ff808d03f061eca0788f14f37d63f2fbc3a0d47e1
+size 72242
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/a0e4d56066bf089079b9b4d24f666b01_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/a0e4d56066bf089079b9b4d24f666b01_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..c3268811e094d3fa38aa4a9b72f477703a9fcfdf
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/a0e4d56066bf089079b9b4d24f666b01_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:a700405431ac496fc2b449ff80088b1d68dc4467fc87f69a0b14c71244187337
+size 63807
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/a2b0b8d868ec4ee43d7d3f0961a12b5e_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/a2b0b8d868ec4ee43d7d3f0961a12b5e_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..30fb8494302a07aab3737cf92e12ba400b0c3c84
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/a2b0b8d868ec4ee43d7d3f0961a12b5e_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:b9fff54b97d3b9a7a57d375a8004cce832c35df5c659333107044b6765221837
+size 21317
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/a37adbbe12ec735a20ead2466363d07a_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/a37adbbe12ec735a20ead2466363d07a_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..42d18a1958253cbf7ddcf632eeac25f0afd68ccb
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/a37adbbe12ec735a20ead2466363d07a_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:cf82e8fb1792033c3272cbffd01e449d88f83fd5f25a869cc51f21513076a006
+size 35792
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/aa22da43c463563d3d0035722bd79449_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/aa22da43c463563d3d0035722bd79449_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..bdf7d5ec755c7ac0017869f5f60c55a024a48184
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/aa22da43c463563d3d0035722bd79449_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:6de7bc37a22f40def52e3f04d8a28f045e8cd9929d703e3295419814eab642cd
+size 55137
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/b3335932702b8668e62791e9fd12c9ff_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/b3335932702b8668e62791e9fd12c9ff_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..6c7361090e7fbfdda291b66a1fcca3f5d7f78a30
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/b3335932702b8668e62791e9fd12c9ff_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:542b961b8ec722e824d3485ae00c31c1536a15ac01189c6ee72846005c449e0b
+size 20700
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/b361fd4d68b14568a6c5acbcd9bfe8ee_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/b361fd4d68b14568a6c5acbcd9bfe8ee_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..f0dba2f1c2090ed932c72e23c922e9240757bbf8
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/b361fd4d68b14568a6c5acbcd9bfe8ee_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:57e62d2f88f6c73b253f405349d13608894001c2a3f14b86f7fd37cae0b7041b
+size 13529
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/bd0283b61b6a59829e9370b29076c79a_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/bd0283b61b6a59829e9370b29076c79a_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..eb529e79f943f776951dedcc9af2d85680e6f8e3
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/bd0283b61b6a59829e9370b29076c79a_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:961bf5afd4a72cc3546458235c25aff29047e542f26d661dd30404b1777050d5
+size 51526
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/bd33d5bc49161429f4c7da76529bcd18_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/bd33d5bc49161429f4c7da76529bcd18_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..b48db89dab03b8c50e6412f57f7cc831bad8da3c
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/bd33d5bc49161429f4c7da76529bcd18_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:bb59adcf70e5b5fd04a1971ea6d3c11574d573fb77a018e7c72b800085893934
+size 50844
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/c2c4e63ebb9afc1ab64e39a159890e0f_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/c2c4e63ebb9afc1ab64e39a159890e0f_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..6f3aaf3965877a6ad1d7e19a28caedb02be87856
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/c2c4e63ebb9afc1ab64e39a159890e0f_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:7a95b10dfd926963c75a6b1d53cc3d98378953bff85a623f982a22d3680ceaa0
+size 54778
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/c93c4b33a2b42c8dd6d82a354f2f89f1_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/c93c4b33a2b42c8dd6d82a354f2f89f1_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..5317894cad029af1d65281c95728972bf055d178
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/c93c4b33a2b42c8dd6d82a354f2f89f1_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:1c45d71e385bd8dd2e534ec0c3077a7c096afaa45f2c2ec96ec0153c18b85bca
+size 29892
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/ca29dcaf8247d96c4fef4ab76ed85076_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/ca29dcaf8247d96c4fef4ab76ed85076_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..dbaceef21fd15bb781c911eef1a1df7bf3ca1366
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/ca29dcaf8247d96c4fef4ab76ed85076_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:ed6d8b4e4f92f09f24d42fe0fa79e21fdfd9411331428ef593ae14c371e7f1e3
+size 56301
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/cbab05075b3d7dc0d27c4cbb0c914a94_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/cbab05075b3d7dc0d27c4cbb0c914a94_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..42db8a14c281564ec67ea0bb5b5801dc910ef878
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/cbab05075b3d7dc0d27c4cbb0c914a94_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:3c55bdc82909aff1caef40817341a80ca0129c9272de31ec4f9d59c1297f84c0
+size 41321
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/d04c50badc78d5ba47bf4e352af4a754_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/d04c50badc78d5ba47bf4e352af4a754_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..d9dac0e73bb751028b58832ed4f9137bee10f480
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/d04c50badc78d5ba47bf4e352af4a754_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:9238cbdff5a06c6fe1d105eef09257d73b44c78d9205214be9fb679fbfe88cfe
+size 54813
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/d1ba2b47c5ebc10187d8e9089eacca4d_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/d1ba2b47c5ebc10187d8e9089eacca4d_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..3edb1ae11c2cc1867278a319d723ecfec3976168
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/d1ba2b47c5ebc10187d8e9089eacca4d_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:f751e5909be994a1123a893b1feaf5a90c166d4cc6dca6781d5d3127fb95e471
+size 69736
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/d79d33da852cb7bca3e87b400a15c3e8_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/d79d33da852cb7bca3e87b400a15c3e8_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..ad3f47470a2f82dcccd8699a4c85fc375ee23376
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/d79d33da852cb7bca3e87b400a15c3e8_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:fb43778edfb85f7701efe36a8e133bc7976a38bfd53166ac851270bb91700bbe
+size 43336
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/d8698aacaeead6dfed9a1e448670a2e4_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/d8698aacaeead6dfed9a1e448670a2e4_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..066362d6cd2c1bb04080a0418e0d5a1477ff006a
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/d8698aacaeead6dfed9a1e448670a2e4_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:a14c77e604402fabc03101bee06b371cb4687af0541d530310a9dc485cb95f7a
+size 41053
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/de63e4b6d8b0aa76b85e1fe3236eac27_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/de63e4b6d8b0aa76b85e1fe3236eac27_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..07dd8537f2d86885d5030902f5050eab7e2fd0a0
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/de63e4b6d8b0aa76b85e1fe3236eac27_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:51993e13b011f679022d1de3a4049612223bd3415757507e74d4c119e393efc8
+size 43790
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/e16bfa31d748f4d99ec4ae3d16656926_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/e16bfa31d748f4d99ec4ae3d16656926_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..9f8069de271d8807ca2fa1ff3d92070bd52ea44b
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/e16bfa31d748f4d99ec4ae3d16656926_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:7bc47dfca38e491afe44ed8ec59381c3151e9e4e9a27c2b51667cf284e8714ae
+size 24327
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/e180f2b5fcbe8001554a7c0677cd3f82_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/e180f2b5fcbe8001554a7c0677cd3f82_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..75e54b05eeb4a9efe7f90a095f1c215457f16e00
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/e180f2b5fcbe8001554a7c0677cd3f82_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:61ccb06efed85ec8128ba62d73756d54a98185a3dce83b32ff9d3278b59bc7a3
+size 46237
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/e18841eb4a995df8354a793459e12fd0_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/e18841eb4a995df8354a793459e12fd0_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..9d05f4debe57d311968215bf9aaa6ce59c3d34ea
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/e18841eb4a995df8354a793459e12fd0_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:38dad0919646321f26179f2cd46819b8aa474de0d82cbccc9a082d9de1c66420
+size 49091
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/e26bb66586e464339df27951d5c9355e_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/e26bb66586e464339df27951d5c9355e_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..6dbe9360069f35e77f5f2c4dea1d6ba16f713392
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/e26bb66586e464339df27951d5c9355e_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:773ca489ccc2f24282162aa78c6cc45a7b50fb94e1465bfd2903ef68b9a9a8d6
+size 36474
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/e47de8ad97151f5c6335b5e83c91a0f4_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/e47de8ad97151f5c6335b5e83c91a0f4_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..7a8a30f34f127ca13215274616e14f50d36af103
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/e47de8ad97151f5c6335b5e83c91a0f4_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:a43faa531eacdab7adb64697219a87bfdfbaa9bde71b3f3d90152b8e5537778c
+size 62455
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/e8e818455bb0d1a6153299a388b94868_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/e8e818455bb0d1a6153299a388b94868_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..2710d17ef8edb3ba2c4b98f41f2b4b35b71a8477
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/e8e818455bb0d1a6153299a388b94868_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:86a0ef39f58173c8ff703872d8a93e62621de32877bcfb0dff33fbe5355d8cfc
+size 85086
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/ed9a039f42c103268d8092afd5e58edb_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/ed9a039f42c103268d8092afd5e58edb_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..8ea8b85ee17d6a6b7b2080b9a1702a2c9c1887a2
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/ed9a039f42c103268d8092afd5e58edb_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:b4bfa239ae487f56c0a747ef7e426224f69ed9222cc5d1cc77cc04784ff092e3
+size 50476
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/ef86416097668984aee7611317e77bb9_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/ef86416097668984aee7611317e77bb9_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..083a6e7806bef859430848dbe6b09ff5827e6ad9
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/ef86416097668984aee7611317e77bb9_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:27377b291e1b2ca4179d300c51afeb6f32cd62793e8f6ab229d32e150736ede4
+size 17061
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/f3f568cc57088117f1c4589f174d3dbf_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/f3f568cc57088117f1c4589f174d3dbf_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..262499f6d495b3614a63c2c64c261af44b86efd8
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/f3f568cc57088117f1c4589f174d3dbf_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:0f66555217c1897f3584525fff67eb525d96437ee7d531253cb11f92118afb4b
+size 69045
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/faa19fa09003307090f38a25ece74252_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/faa19fa09003307090f38a25ece74252_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..f278759a5db066d68bf4f318b974455e8fb454de
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/faa19fa09003307090f38a25ece74252_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:f528a7df47d8587d204b172b57bb939294e04f4188bc3e28f75a89e9de6e0221
+size 59011
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/fb18a83d10ebdad8e3e5ea2e86b36136_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/fb18a83d10ebdad8e3e5ea2e86b36136_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..c0e69f99e2627ed0efd5ed17a2c9fb83e0baff6e
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/fb18a83d10ebdad8e3e5ea2e86b36136_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:dc9de297b4cbd5f33282ef3259902547ead62fe0dd1060b68fef174b4656dbad
+size 43480
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/fda85db2e355bb8e3edcd5a74bf3d673_img.jpg b/marked/T/T-REC-T.171-199610-I_PDF-E/fda85db2e355bb8e3edcd5a74bf3d673_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..1ab7b4118b2c62f4ebbb6d1f5024f632ad128d4d
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/fda85db2e355bb8e3edcd5a74bf3d673_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:144c47564d5fcbbcc133c819b4780e6d28b5e71e23ff333bf645996c06bbbec1
+size 46084
diff --git a/marked/T/T-REC-T.171-199610-I_PDF-E/raw.md b/marked/T/T-REC-T.171-199610-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..5534e36c1a89d23a4c9ff6852ecd10ab26bcdd65
--- /dev/null
+++ b/marked/T/T-REC-T.171-199610-I_PDF-E/raw.md
@@ -0,0 +1,16368 @@
+
+
+![ITU logo: a globe with the letters ITU and a lightning bolt.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg)
+
+ITU logo: a globe with the letters ITU and a lightning bolt.
+
+INTERNATIONAL TELECOMMUNICATION UNION
+
+# ITU-T
+
+TELECOMMUNICATION  
+STANDARDIZATION SECTOR  
+OF ITU
+
+# T.171
+
+(10/96)
+
+SERIES T: TERMINALS FOR TELEMATIC SERVICES
+
+---
+
+**Protocols for interactive audiovisual services:  
+coded representation of multimedia and  
+hypermedia objects**
+
+ITU-T Recommendation T.171
+
+(Previously CCITT Recommendation)
+
+---
+
+# ITU-T T-SERIES RECOMMENDATIONS **TERMINALS FOR TELEMATIC SERVICES**
+
+*For further details, please refer to ITU-T List of Recommendations.*
+
+
+
+# FOREWORD
+
+The ITU-T (Telecommunication Standardization Sector) is a permanent organ of the International Telecommunication Union (ITU). The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis.
+
+The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics.
+
+The approval of Recommendations by the Members of the ITU-T is covered by the procedure laid down in WTSC Resolution No. 1 (Helsinki, March 1-12, 1993).
+
+ITU-T Recommendation T.171 was prepared by ITU-T Study Group 8 (1993-1996) and was approved by the WTSC (Geneva, October 9-18, 1996).
+
+## --- NOTE
+
+In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+© ITU 1997
+
+All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU.
+
+# CONTENTS
+
+|                                                                                  | <i>Page</i> |
+|----------------------------------------------------------------------------------|-------------|
+| 0 Introduction .....                                                             | 1           |
+| 0.1 Application domains for requirements analysis .....                          | 1           |
+| 0.2 Multimedia/Hypermedia application requirements .....                         | 2           |
+| 0.3 Rationale for standardisation of multimedia and hypermedia information ..... | 4           |
+| 0.4 T.171 Objectives .....                                                       | 5           |
+| 0.5 T.171 concepts .....                                                         | 6           |
+| 0.6 The MHEG application interface .....                                         | 10          |
+| 0.7 T.171 extensibility .....                                                    | 10          |
+| 1 Scope .....                                                                    | 10          |
+| 1.1 Specificity of the scope .....                                               | 11          |
+| 1.2 Issues outside T.171 scope .....                                             | 11          |
+| 2 Conformance .....                                                              | 11          |
+| 2.1 Profiles .....                                                               | 11          |
+| 2.2 Syntax .....                                                                 | 11          |
+| 2.3 Semantics .....                                                              | 11          |
+| 3 Normative References .....                                                     | 12          |
+| 4 Definitions .....                                                              | 12          |
+| 5 Symbols and abbreviations .....                                                | 19          |
+| SECTION 1 – OVERVIEW .....                                                       | 21          |
+| 6 T.171 principal feature .....                                                  | 21          |
+| 6.1 Interchanging multimedia objects .....                                       | 21          |
+| 6.2 The object-oriented approach .....                                           | 21          |
+| 6.3 Technical features .....                                                     | 23          |
+| 7 MHEG Engine Assumptions .....                                                  | 27          |
+| 7.1 Handling and Interchange of objects .....                                    | 27          |
+| 7.2 The MHEG application interface .....                                         | 28          |
+| 7.3 Exception handling .....                                                     | 29          |
+| 8 Methodology .....                                                              | 29          |
+| 8.1 Modularity .....                                                             | 29          |
+| 8.2 Methodology of representation of MHEG objects .....                          | 29          |
+| SECTION 2 – GENERIC UTILITY AND USEFUL DEFINITION MECHANISMS .....               | 33          |
+| 9 Presentation Mechanism .....                                                   | 33          |
+| 9.1 Presentation Space (PS) .....                                                | 34          |
+| 9.2 Original Presentation Space (OPS) .....                                      | 37          |
+| 9.3 Channel Presentation Space (CPS) .....                                       | 38          |
+| 9.4 Relative Presentation Space (RPS) .....                                      | 39          |
+| 9.5 CPS mapping .....                                                            | 39          |
+| 10 Generic identification mechanism .....                                        | 40          |
+| 10.1 External identification .....                                               | 41          |
+| 10.2 Internal identification .....                                               | 43          |
+| 10.3 Symbolic identification .....                                               | 47          |
+| 11 Generic reference mechanism .....                                             | 47          |
+| 11.1 Generic reference using generic identification .....                        | 47          |
+| 11.2 Predefined references .....                                                 | 50          |
+| 11.3 ? reference .....                                                           | 50          |
+
+|                                                 | <i>Page</i> |
+|-------------------------------------------------|-------------|
+| 12 Generic Value.....                           | 52          |
+| 12.1 Generic boolean.....                       | 53          |
+| 12.2 Generic numeric.....                       | 53          |
+| 12.3 Generic integer.....                       | 53          |
+| 12.4 Generic ratio .....                        | 53          |
+| 12.5 Generic string.....                        | 54          |
+| 12.6 Generic reference.....                     | 54          |
+| 12.7 Generic list.....                          | 54          |
+| 13 Macro Mechanism.....                         | 54          |
+| 14 Hooks .....                                  | 56          |
+| 15 Extensibility .....                          | 57          |
+| 15.1 Catalogues.....                            | 57          |
+| 15.2 Addition of New MHEG object classes.....   | 58          |
+| 15.3 Extensibility Provision.....               | 58          |
+| SECTION 3 – OVERVIEW OF MHEG CLASSES .....      | 58          |
+| 16 MHEG object classes overview .....           | 58          |
+| 17 Structure of MH-Object Class.....            | 59          |
+| 17.1 Class identification .....                 | 59          |
+| 17.2 MHEG-ID.....                               | 59          |
+| 17.3 General object information .....           | 59          |
+| 18 Structure of Action Class .....              | 60          |
+| 18.1 Elementary actions.....                    | 60          |
+| 18.2 Basic action object.....                   | 61          |
+| 18.3 Nested action object.....                  | 61          |
+| 18.4 Macro action object .....                  | 61          |
+| 19 Structure of Link Class.....                 | 61          |
+| 19.1 Link Condition.....                        | 62          |
+| 19.2 Link Effect.....                           | 71          |
+| 19.3 Basic link object .....                    | 71          |
+| 19.4 Nested link object .....                   | 71          |
+| 19.5 Macro link object.....                     | 72          |
+| 20 Structure of Model Class.....                | 72          |
+| 21 Structure of Script Class.....               | 72          |
+| 22 Structure of Component Class.....            | 72          |
+| 23 Structure of Content Class.....              | 73          |
+| 24 Structure of Multiplexed Content Class ..... | 73          |
+| 25 Structure of Composite Class .....           | 74          |
+| 25.1 Availability Start-up .....                | 75          |
+| 25.2 Availability Close-down.....               | 76          |
+| 25.3 RT-Availability Start-up.....              | 76          |
+| 25.4 Rt-Availability Close-down.....            | 76          |
+| 25.5 Composition Element .....                  | 77          |
+| 25.6 Composition example .....                  | 77          |
+| 26 Structure of Container Class .....           | 78          |
+| 26.1 Container Start-up.....                    | 78          |
+| 26.2 Container Close-down .....                 | 78          |
+| 26.3 Container Element .....                    | 78          |
+
+|                                                     | <i>Page</i>                                       |
+|-----------------------------------------------------|---------------------------------------------------|
+| 27                                                  | Structure of Descriptor Class ..... 79            |
+| 27.1                                                | Related Object ..... 79                           |
+| 27.2                                                | Other Descriptor ..... 81                         |
+| 27.3                                                | Readme ..... 81                                   |
+| 27.4                                                | System Readable Material ..... 81                 |
+| 27.5                                                | Channel Information ..... 81                      |
+| 27.6                                                | Catalogued Style Information ..... 82             |
+| 27.7                                                | Cat Ext elementary action info ..... 82           |
+| 27.8                                                | Cat Ext Attribute Info ..... 82                   |
+| SECTION 4 – MHEG ENTITIES COMMON BEHAVIOUR ..... 82 |                                                   |
+| 28                                                  | MHEG entity behaviour ..... 82                    |
+| 29                                                  | MHEG entity state definition ..... 82             |
+| 29.1                                                | MHEG object availability ..... 83                 |
+| 29.2                                                | Link activation ..... 84                          |
+| 29.3                                                | Channel availability ..... 85                     |
+| 29.4                                                | Rt-object availability ..... 86                   |
+| 29.5                                                | Rt-Component running behaviour ..... 88           |
+| 29.6                                                | Rt-Component presentation behaviour ..... 89      |
+| 30                                                  | Life cycle of MHEG entities ..... 92              |
+| 31                                                  | General action mechanisms ..... 92                |
+| 31.1                                                | Action treatment ..... 92                         |
+| 31.2                                                | Processing of link effect ..... 93                |
+| 31.3                                                | Basic processing of an elementary action ..... 95 |
+| 31.4                                                | Resolution of target set ..... 95                 |
+| 31.5                                                | Arithmetic precision ..... 95                     |
+| 32                                                  | Common action effects and handling ..... 96       |
+| 32.1                                                | Elementary actions ..... 96                       |
+| 32.2                                                | Get actions ..... 96                              |
+| 32.3                                                | Recommended exception handling ..... 97           |
+| 33                                                  | Postpone Behaviour ..... 97                       |
+| 33.1                                                | Behaviour attributes and statuses ..... 97        |
+| 33.2                                                | Actions to change the behaviour ..... 97          |
+| 34                                                  | Returnability Behaviour ..... 98                  |
+| 34.1                                                | Behaviour attributes and statuses ..... 98        |
+| 34.2                                                | Actions to change the behaviour ..... 98          |
+| 35                                                  | Alias Behaviour ..... 98                          |
+| 35.1                                                | Behaviour attributes and statuses ..... 98        |
+| 35.2                                                | Actions to change the behaviour ..... 98          |
+| 36                                                  | Extensibility Behaviour ..... 99                  |
+| 36.1                                                | Behaviour attributes and statuses ..... 99        |
+| 36.2                                                | Catalogued Attribute ..... 99                     |
+| 36.3                                                | Actions to change the behaviour ..... 99          |
+| 36.4                                                | Actions to retrieve the behaviour ..... 100       |
+| SECTION 5 – MHEG OBJECTS BEHAVIOUR ..... 101        |                                                   |
+| 37                                                  | MHEG Objects Availability Behaviour ..... 101     |
+| 37.1                                                | Behaviour attributes and statuses ..... 101       |
+| 37.2                                                | Preparation Status ..... 101                      |
+| 37.3                                                | Actions to change the behaviour ..... 101         |
+| 37.4                                                | Actions to retrieve the behaviour ..... 104       |
+
+|    | <i>Page</i>                                                      |
+|----|------------------------------------------------------------------|
+| 38 | Link Object Activation Behaviour ..... 104                       |
+|    | 38.1 Behaviour attributes and statuses..... 104                  |
+|    | 38.2 Activation Status..... 105                                  |
+|    | 38.3 Actions to change the behaviour..... 105                    |
+|    | 38.4 Actions to retrieve the behaviour..... 105                  |
+| 39 | Link Object Abort Behaviour..... 106                             |
+|    | 39.1 Behaviour attributes and statuses..... 106                  |
+|    | 39.2 Actions to change the behaviour..... 106                    |
+| 40 | Content Class Generic Value Storage Behaviour..... 107           |
+|    | 40.1 Behaviour attributes and statuses..... 107                  |
+|    | 40.2 Data..... 107                                               |
+|    | 40.3 Actions to change the behaviour..... 107                    |
+|    | 40.4 Actions to retrieve the behaviour..... 112                  |
+| 41 | Content Class Copy Behaviour ..... 113                           |
+|    | 41.1 Behaviour attributes and statuses..... 113                  |
+|    | 41.2 Actions to change the behaviour..... 113                    |
+|    | SECTION 6 – RT-OBJECTS BEHAVIOUR ..... 114                       |
+| 42 | Rt-Objects Availability Behaviour..... 114                       |
+|    | 42.1 Behaviour attributes and statuses..... 114                  |
+|    | 42.2 Rt-Availability Status ..... 114                            |
+|    | 42.3 Actions to change the behaviour..... 114                    |
+|    | 42.4 Actions to retrieve the behaviour..... 116                  |
+| 43 | Rt-Objects Running Behaviour ..... 117                           |
+|    | 43.1 Behaviour attributes and statuses..... 117                  |
+|    | 43.2 Running Status..... 117                                     |
+|    | 43.3 Actions to change the behaviour..... 117                    |
+|    | 43.4 Actions to retrieve the behaviour..... 119                  |
+| 44 | Rt-Script Passing Parameters Behaviour..... 120                  |
+|    | 44.1 Behaviour attributes and statuses..... 120                  |
+|    | 44.2 Actions to change the behaviour..... 120                    |
+| 45 | Rt-Scripts Termination Behaviour ..... 121                       |
+|    | 45.1 Behaviour attributes and statuses..... 121                  |
+|    | 45.2 Termination Status..... 121                                 |
+|    | 45.3 Actions to retrieve the behaviour..... 121                  |
+| 46 | Sockets Presentation and Structural Dynamism Behaviour ..... 122 |
+|    | 46.1 Behaviour attributes and statuses..... 122                  |
+|    | 46.2 Actions to change the behaviour..... 122                    |
+| 47 | Rt-Composite Navigation Behaviour ..... 124                      |
+|    | 47.1 Behaviour attributes and statuses..... 124                  |
+|    | 47.2 Rt-Composite Address..... 124                               |
+|    | 47.3 Navigation Command..... 124                                 |
+|    | 47.4 Child ..... 124                                             |
+|    | 47.5 EmptyChild..... 124                                         |
+|    | 47.6 Sibling..... 124                                            |
+|    | 47.7 Ancestor..... 124                                           |
+|    | 47.8 Actions to retrieve the behaviour..... 125                  |
+| 48 | Rt-Components Rps Assignment Behaviour..... 125                  |
+|    | 48.1 Behaviour attributes and statuses..... 125                  |
+|    | 48.2 RPS Assignment ..... 125                                    |
+|    | 48.3 Actions to change the behaviour..... 125                    |
+|    | 48.4 Actions to retrieve the behaviour..... 126                  |
+
+|       |                                             |     |
+|-------|---------------------------------------------|-----|
+| 49    | Rt-Components Perceptability Behaviour..... | 127 |
+| 49.1  | Behaviour attributes and statuses.....      | 127 |
+| 49.2  | Perceptability .....                        | 127 |
+| 49.3  | Presentation Priority .....                 | 127 |
+| 49.4  | Actions to change the behaviour.....        | 127 |
+| 49.5  | Actions to retrieve the behaviour.....      | 129 |
+| 50    | Rt-Components Temporal Behaviour .....      | 129 |
+| 50.1  | Behaviour attributes and statuses.....      | 129 |
+| 50.2  | OD .....                                    | 130 |
+| 50.3  | POD .....                                   | 130 |
+| 50.4  | OVD.....                                    | 130 |
+| 50.5  | PVD .....                                   | 130 |
+| 50.6  | Temporal Termination .....                  | 130 |
+| 50.7  | PVD Position .....                          | 131 |
+| 50.8  | CTP .....                                   | 132 |
+| 50.9  | GTF .....                                   | 133 |
+| 50.10 | Timestone Status.....                       | 133 |
+| 50.11 | Timestone ID .....                          | 133 |
+| 50.12 | Expected OVD Result.....                    | 133 |
+| 50.13 | Expected PVD Result .....                   | 133 |
+| 50.14 | Actions to change the behaviour.....        | 133 |
+| 50.15 | Actions to retrieve the behaviour.....      | 136 |
+| 51    | Rt-Components Spatial Behaviour .....       | 141 |
+| 51.1  | Behaviour attributes and statuses.....      | 141 |
+| 51.2  | OS .....                                    | 141 |
+| 51.3  | POS .....                                   | 141 |
+| 51.4  | Aspect Ratio.....                           | 141 |
+| 51.5  | Resizing Strategy .....                     | 142 |
+| 51.6  | OVS .....                                   | 143 |
+| 51.7  | OAP .....                                   | 143 |
+| 51.8  | OVS Position .....                          | 143 |
+| 51.9  | PVS.....                                    | 144 |
+| 51.10 | OVS Proj Strategy .....                     | 144 |
+| 51.11 | PAP .....                                   | 144 |
+| 51.12 | PVS Position.....                           | 144 |
+| 51.13 | GSF.....                                    | 144 |
+| 51.14 | Spatial Control.....                        | 145 |
+| 51.15 | User Spatial Control .....                  | 145 |
+| 51.16 | Expected Axis Result Param.....             | 145 |
+| 51.17 | Point Type Param .....                      | 145 |
+| 51.18 | Actions to change the behaviour.....        | 145 |
+| 51.19 | Actions to retrieve the behaviour.....      | 151 |
+| 52    | Rt-Components Audible Behaviour .....       | 157 |
+| 52.1  | Behaviour attributes and statuses.....      | 157 |
+| 52.2  | OV .....                                    | 157 |
+| 52.3  | CV.....                                     | 157 |
+| 52.4  | PCV .....                                   | 157 |
+| 52.5  | GVF .....                                   | 158 |
+| 52.6  | Actions to change the behaviour.....        | 158 |
+| 52.7  | Actions to retrieve the behaviour.....      | 159 |
+
+|                                                        | <i>Page</i> |
+|--------------------------------------------------------|-------------|
+| 53 Rt-Mux Stream Choice Behaviour .....                | 160         |
+| 53.1 Behaviour attributes and statuses .....           | 160         |
+| 53.2 Stream Choice .....                               | 161         |
+| 53.3 Stream Chosen State .....                         | 161         |
+| 53.4 Stream Identification .....                       | 161         |
+| 53.5 Actions to change the behaviour .....             | 161         |
+| 53.6 Actions to retrieve the behaviour .....           | 161         |
+| 54 Interaction Behaviour .....                         | 162         |
+| 54.1 Behaviour attributes and statuses .....           | 163         |
+| 54.2 Interaction Type .....                            | 163         |
+| 54.3 Interaction Status .....                          | 163         |
+| 54.4 Selection Status .....                            | 163         |
+| 54.5 Modification Status .....                         | 164         |
+| 54.6 Interaction Ability .....                         | 164         |
+| 54.7 Selectability .....                               | 164         |
+| 54.8 Modifiability .....                               | 164         |
+| 54.9 Min Interact Required .....                       | 164         |
+| 54.10 Max Interact Required .....                      | 165         |
+| 54.11 Number of Interacted Sockets .....               | 165         |
+| 54.12 Actions to change the behaviour .....            | 166         |
+| 54.13 Actions to retrieve the behaviour .....          | 167         |
+| 55 Rt-Components Style Behaviour .....                 | 169         |
+| 55.1 Behaviour attributes and statuses .....           | 170         |
+| 55.2 Style .....                                       | 170         |
+| 55.3 Actions to change the behaviour .....             | 170         |
+| 55.4 Actions to change the behaviour .....             | 170         |
+| 56 Rt-Contents Anchor Behaviour .....                  | 171         |
+| 56.1 Behaviour attributes and statuses .....           | 171         |
+| 56.2 Actions to change the behaviour .....             | 171         |
+| SECTION 7 – CHANNELS BEHAVIOUR .....                   | 173         |
+| 57 Channel Availability Behaviour .....                | 173         |
+| 57.1 Behaviour attributes and statuses .....           | 173         |
+| 57.2 Channel Availability Status .....                 | 173         |
+| 57.3 Actions to change the behaviour .....             | 173         |
+| 57.4 Actions to retrieve the behaviour .....           | 174         |
+| 58 Channel Perceptability Behaviour .....              | 175         |
+| 58.1 Behaviour attributes and statuses .....           | 175         |
+| 58.2 Channel Perceptability .....                      | 175         |
+| 58.3 Actions to change the behaviour .....             | 175         |
+| 58.4 Actions to retrieve the behaviour .....           | 176         |
+| 59 Channel Presentation Space Behaviour .....          | 176         |
+| 59.1 Behaviour attributes and statuses .....           | 176         |
+| 59.2 Actions to change the behaviour .....             | 176         |
+| SECTION 8 – CHANNELS AND RT-COMPONENTS BEHAVIOUR ..... | 177         |
+| 60 Channels and Rt-Components Events Behaviour .....   | 177         |
+| 60.1 Behaviour attributes and statuses .....           | 177         |
+| 60.2 Event .....                                       | 177         |
+| 60.3 Event Data .....                                  | 177         |
+| 60.4 Actions to change the behaviour .....             | 177         |
+| 60.5 Actions to retrieve the behaviour .....           | 178         |
+
+|                                                           |     |
+|-----------------------------------------------------------|-----|
+| SECTION 9 – DETAILED REPRESENTATION OF MHEG OBJECTS ..... | 179 |
+| 61 MH-object class representation attributes .....        | 179 |
+| 61.1 MH-object Class .....                                | 179 |
+| 61.2 Class Identification .....                           | 179 |
+| 61.3 Class ID .....                                       | 180 |
+| 61.4 Description .....                                    | 180 |
+| 61.5 Name .....                                           | 180 |
+| 61.6 Owner .....                                          | 180 |
+| 61.7 Version .....                                        | 180 |
+| 61.8 Date .....                                           | 180 |
+| 61.9 Keywords .....                                       | 180 |
+| 61.10 Copyright .....                                     | 180 |
+| 61.11 Copyright ID .....                                  | 180 |
+| 61.12 Copyright Number .....                              | 180 |
+| 61.13 Licence .....                                       | 180 |
+| 61.14 Cache Priority .....                                | 181 |
+| 61.15 Comments .....                                      | 181 |
+| 62 Action class representation attributes .....           | 181 |
+| 62.1 Action Class .....                                   | 181 |
+| 62.2 Synchro Indicator Param .....                        | 181 |
+| 62.3 Synchro Indicator Macro .....                        | 181 |
+| 62.4 Synchro Indicator .....                              | 182 |
+| 62.5 Synchronised Action .....                            | 182 |
+| 62.6 Action Object .....                                  | 182 |
+| 63 Link class representation attributes .....             | 182 |
+| 63.1 Link Class .....                                     | 182 |
+| 63.2 Link Condition .....                                 | 183 |
+| 63.3 Trigger Condition .....                              | 183 |
+| 63.4 Constraint Condition .....                           | 183 |
+| 63.5 Source Value .....                                   | 183 |
+| 63.6 Comparison Operation .....                           | 183 |
+| 63.7 Comparison Value .....                               | 183 |
+| 63.8 Previous Condition .....                             | 183 |
+| 63.9 Current Condition .....                              | 183 |
+| 63.10 Comparison Operator .....                           | 183 |
+| 63.11 Logical Combination .....                           | 184 |
+| 63.12 Logical Operator .....                              | 184 |
+| 63.13 Condition .....                                     | 184 |
+| 63.14 Link Effect .....                                   | 184 |
+| 63.15 Macro Parameter Resolution .....                    | 184 |
+| 63.16 Usage Value .....                                   | 184 |
+| 64 Model class representation attributes .....            | 184 |
+| 64.1 Model Class .....                                    | 184 |
+| 65 Script class representation attributes .....           | 185 |
+| 65.1 Script Class .....                                   | 185 |
+| 65.2 Script Classification .....                          | 185 |
+| 65.3 Script Data .....                                    | 185 |
+| 65.4 Script Inclusion .....                               | 185 |
+| 65.5 InterchangedScript .....                             | 185 |
+| 66 Component class representation attributes .....        | 185 |
+| 66.1 Component Class .....                                | 186 |
+
+|       | <i>Page</i>                                                   |
+|-------|---------------------------------------------------------------|
+| 67    | Content class representation attributes ..... 186             |
+| 67.1  | Content Class ..... 186                                       |
+| 67.2  | Content Data ..... 186                                        |
+| 67.3  | Data Inclusion ..... 186                                      |
+| 68    | Multiplexed content class representation attributes ..... 186 |
+| 68.1  | Multiplexed Content Class ..... 187                           |
+| 68.2  | Multiplexed Stream ..... 187                                  |
+| 69    | Composite class representation attributes ..... 187           |
+| 69.1  | Composite Class ..... 187                                     |
+| 69.2  | Availability Start-up ..... 188                               |
+| 69.3  | Availability Close-down ..... 188                             |
+| 69.4  | Rt-Availability Start-up ..... 188                            |
+| 69.5  | Rt-Availability Close-down ..... 188                          |
+| 69.6  | Link Object ..... 188                                         |
+| 69.7  | Nb of Elements ..... 188                                      |
+| 69.8  | Composition Element ..... 188                                 |
+| 69.9  | Element Index ..... 189                                       |
+| 69.10 | Associated Model ..... 189                                    |
+| 69.11 | Label ..... 189                                               |
+| 70    | Container class representation attributes ..... 189           |
+| 70.1  | Container Class ..... 189                                     |
+| 70.2  | Container Start-up ..... 189                                  |
+| 70.3  | Container Close-down ..... 190                                |
+| 70.4  | Container Element ..... 190                                   |
+| 71    | Descriptor class representation attributes ..... 190          |
+| 71.1  | Descriptor Class ..... 191                                    |
+| 71.2  | Related Object ..... 191                                      |
+| 71.3  | Object Information ..... 191                                  |
+| 71.4  | Object Size ..... 191                                         |
+| 71.5  | Class Specific Information ..... 191                          |
+| 71.6  | Script Class Information ..... 191                            |
+| 71.7  | Content Class Information ..... 192                           |
+| 71.8  | Mux Content Class Info ..... 192                              |
+| 71.9  | Number of Streams ..... 192                                   |
+| 71.10 | Stream Information ..... 192                                  |
+| 71.11 | Alternative Object ..... 192                                  |
+| 71.12 | Alternative Descriptor Object ..... 192                       |
+| 71.13 | Alternative Readme ..... 192                                  |
+| 71.14 | Offset ..... 192                                              |
+| 71.15 | Other Descriptor ..... 192                                    |
+| 71.16 | Readme ..... 192                                              |
+| 71.17 | System Readable Material ..... 192                            |
+| 71.18 | Channel Information ..... 193                                 |
+| 71.19 | X min ..... 193                                               |
+| 71.20 | X max ..... 193                                               |
+| 71.21 | Y min ..... 193                                               |
+| 71.22 | Y max ..... 193                                               |
+| 71.23 | Z min ..... 193                                               |
+| 71.24 | Z max ..... 193                                               |
+| 71.25 | X Resolution ..... 193                                        |
+| 71.26 | Y Resolution ..... 193                                        |
+
+|                                                                                            | <i>Page</i> |
+|--------------------------------------------------------------------------------------------|-------------|
+| 71.27 Z Resolution.....                                                                    | 193         |
+| 71.28 T Resolution.....                                                                    | 193         |
+| 71.29 F min.....                                                                           | 194         |
+| 71.30 F max .....                                                                          | 194         |
+| 71.31 Audio Dynamic.....                                                                   | 194         |
+| 71.32 Channel Media Type.....                                                              | 194         |
+| 71.33 Event Mapping.....                                                                   | 194         |
+| 71.34 Catalogued Style Information.....                                                    | 194         |
+| 71.35 Cat Ext elementary action Info .....                                                 | 194         |
+| 71.36 Cat Ext Attribute Info .....                                                         | 194         |
+| 72 Behaviours.....                                                                         | 194         |
+| 72.1 Postpone behaviour.....                                                               | 194         |
+| 72.2 Returnability behaviour .....                                                         | 195         |
+| 72.3 Alias behaviour.....                                                                  | 196         |
+| 72.4 Extensibility behaviour.....                                                          | 196         |
+| 72.5 Mheg objects availability behaviour.....                                              | 197         |
+| 72.6 Link object activation behaviour .....                                                | 197         |
+| 72.7 Link object abort behaviour.....                                                      | 198         |
+| 72.8 Content class generic value storage behaviour .....                                   | 198         |
+| 72.9 Content class copy behaviour .....                                                    | 199         |
+| 72.10 Rt-objects availability behaviour .....                                              | 200         |
+| 72.11 Rt-objects running behaviour .....                                                   | 200         |
+| 72.12 Rt-script passing parameter behaviour.....                                           | 201         |
+| 72.13 Sockets presentation and structural dynamism behaviour .....                         | 201         |
+| 72.14 Rt-components rps assignment behaviour .....                                         | 202         |
+| 72.15 Rt-components perceptability behaviour .....                                         | 202         |
+| 72.16 Rt-components temporal behaviour.....                                                | 203         |
+| 72.17 Rt-components spatial behaviour.....                                                 | 205         |
+| 72.18 Rt-components audible behaviour .....                                                | 207         |
+| 72.19 Rt-mux stream choice behaviour .....                                                 | 208         |
+| 72.20 Interaction behaviour .....                                                          | 209         |
+| 72.21 Rt-components style behaviour .....                                                  | 210         |
+| 72.22 Rt-contents anchor behaviour .....                                                   | 210         |
+| 72.23 Channel availability behaviour.....                                                  | 211         |
+| 72.24 Channel perceptability behaviour .....                                               | 211         |
+| 72.25 Channel presentation space behaviour.....                                            | 212         |
+| 72.26 Channels and rt-components events behaviour.....                                     | 212         |
+| 73 Elementary Actions.....                                                                 | 213         |
+| 73.1 List of elementary actions.....                                                       | 213         |
+| 73.2 MHEG entity, data, stream, macro parameter and identification useful definitions..... | 214         |
+| 73.3 References useful definitions.....                                                    | 217         |
+| 73.4 Useful definitions of targets.....                                                    | 222         |
+| 73.5 Generic value useful definitions .....                                                | 226         |
+| 73.6 Evaluated values useful definitions .....                                             | 230         |
+| 73.7 Hooks.....                                                                            | 238         |
+| 73.8 Extensibility .....                                                                   | 238         |
+| 73.9 Presentation space useful definitions .....                                           | 242         |
+| 73.10 Constants useful definitions.....                                                    | 249         |
+| 73.11 Comparison value constants .....                                                     | 256         |
+
+|                                                                          | <i>Page</i> |
+|--------------------------------------------------------------------------|-------------|
+| Annex A – ASN.1 notations (Level C) Coded representation (Level D) ..... | 257         |
+| Annex B – Examples of MHEG systems .....                                 | 291         |
+| B.1 Example of an MHEG Engine .....                                      | 291         |
+| B.2 Application examples .....                                           | 295         |
+| Annex C – Interfaces to media Recommendations and Standards .....        | 302         |
+| C.1 Example of still image content object.....                           | 302         |
+| C.2 Example of audio content object .....                                | 303         |
+| Annex D – Hypertext/Hypermedia Support .....                             | 303         |
+| D.1 Introduction .....                                                   | 303         |
+| D.2 Mechanism for Hypertext/Hypermedia .....                             | 304         |
+| D.3 An example of interrelationships between MHEG and WWW browser .....  | 305         |
+| Annex E – Examples of spatial behaviours .....                           | 306         |
+| E.1 Example 1 .....                                                      | 306         |
+| E.2 Example 2 .....                                                      | 311         |
+| Annex F – Summary of Object Identifiers .....                            | 313         |
+| Annex G – Index .....                                                    | 314         |
+
+## **SUMMARY**
+
+This Recommendation provides an encoding for multimedia/hypermedia information to be used and interchanged by applications in a wide range of domains.
+
+## PROTOCOLS FOR INTERACTIVE AUDIOVISUAL SERVICES: CODED REPRESENTATION OF MULTIMEDIA AND HYPERMEDIA OBJECTS
+
+*(Geneva, 1996)*
+
+### 0 Introduction
+
+This Recommendation provides an encoding for multimedia/hypermedia information to be used and interchanged by applications in a wide range of domains.
+
+The design of this Recommendation has been driven by an analysis of application requirements to identify the generic aspects of these applications and incorporate them in a simple encoding.
+
+#### 0.1 Application domains for requirements analysis
+
+In recent years, an explosion of multimedia applications and services has been apparent in many domains. This subclause illustrates the very wide range of audiovisual computer-based applications on which the requirements analysis has been made.
+
+- **Training and education (also known as teletraining):** The extension of data processing and telematics to support audiovisuals makes it a more attractive tool to educators because it improves the interface with the students. There is also a need to exchange audiovisuals between tools and to reuse audiovisuals in other applications. The audiovisuals must be structured in such a way that they can be updated, modified and personalised easily.
+- **Simulation and games:** These can be made much more realistic by the use of multiple media in computer-based systems. Examples are flight and maritime simulators; these applications are highly interactive.
+- **Sales and advertising:** The association of attractive audiovisuals, showing the products to best advantage, with the stock control and ordering process is a natural commercial evolution.
+- **Office information systems, engineering documentation:** There is a long-standing need to be able to integrate drawings, images, audio and video into all types of office documentation. Integrated documents would also provide an attractive means of internal enterprise communication.
+- **Culture:** The computer processing of audiovisual information makes it possible to extend the audience for theatres, museums and cultural events. It also opens the possibility of new art forms.
+- **Electronic publishing and electronic books:** Much material that is currently published on paper could be enhanced by the integration of audiovisuals and by being available in a hypertext manner over a telecommunication network, for example, tourist guides and yellow pages, which could be a mixed sales and advertising application.
+- **Public information:** The use of audiovisual interfaces makes it possible for the public to use computer-based, real-time information systems, for example, a kiosk at which information is accessed through videotex or locally from CD.
+- **Computer-supported multimedia cooperative work:** There is a need to form effective teams of people who are geographically separated but want to share text, graphics, image, audio and other information, for example, remote maintenance, joint authorship or multimedia electronic mail.
+- **Medical applications:** There is a need for a timely retrieval of audiovisual information, including medical images, medical data and case history, in an integrated way from a remote site. This could be a mixed cooperative work application with different medical experts.
+
+---
+
+<sup>1)</sup> This text is technically aligned with ISO/IEC 13522-1.
+
+- **Interactive television applications:** The emergence of digital television systems on terrestrial, satellite or cable networks, as well as the availability of New modulation and transmission techniques on the telephone network, creates favourable conditions for a New offer of interactive multimedia services based on the merging of television and telematics technologies, providing the users with interactive access to video documents.
+- **New classes of applications:** The widespread availability of remote access to audiovisual data processing systems makes possible New classes of applications such as interactive television, customised news programmes and archive materials.
+
+In the following subclauses, the specific needs of communicating multimedia/hypermedia applications from these domains are examined, leading to a list of application requirements. This set of requirements constitutes the global framework of this Recommendation.
+
+## 0.2 Multimedia/Hypermedia application requirements
+
+In the various domains presented above, interactive multimedia systems are perceived to have increased impact on users through their use of image, video and audio, in addition to traditional text information.
+
+The development of these systems is based upon support for multimedia information in the following areas:
+
+- **Platforms:** Emerging compression standards, such as JPEG (ISO/IEC 10918) or MPEG (ISO/IEC 11172 and ISO/IEC 13818), have enabled the development of dedicated hardware, which, in the future, will be provided as a standard system resource.
+- **Storage:** The increasing capacity of magnetic and optical disks, combined with compression techniques, enables the storage of increasing amounts of high bandwidth information.
+- **Communication:** The increasing availability and bandwidth of digital transmission media, such as ISDN and other broadband telecommunication and broadcasting networks, enables the appropriate exchange of large amounts of data.
+
+Using these facilities, it is anticipated that multimedia applications will be designed to Run on heterogeneous platforms and will be interconnected to offer multimedia services.
+
+These multimedia applications and services will use large quantities of structured multimedia objects resident in workstations, stored on digital interchange medium and retrieved or distributed from remote sources through a network. These multimedia data will represent a significant investment and it is vital that the information be applicable in a world of rapidly evolving systems and technologies. In particular, it is important that information should be interchangeable between the data structures supported by different applications.
+
+The following application requirements can be identified:
+
+- Multimedia database retrieval.
+- Frequent updates of multimedia data.
+- Manipulation of a set of data elements.
+- Creation of multimedia documents on a range of workstations.
+- Composition of multimedia data in time and space.
+- Ability to link part of a document with some other part of the same or another document in an open hyperdocument environment.
+- Synchronisation.
+- Elementary synchronisation: Two objects are synchronised with regard to the same reference origin time (parallel mode) or one with regard to the other (sequential mode).
+- Chained synchronisation: A set of objects are presented one after another in the form of a chain.
+- Cyclic synchronisation: One or more objects are repetitively presented.
+- Conditional synchronisation: The presentation of an object is linked to the satisfaction of a condition.
+
+- Reuse of multimedia data by integration in different documents.
+- Exchange of multimedia data between heterogeneous systems.
+- Space wide range of users, including closed user groups.
+- Real-time interactivity, including acquisition of multimedia data.
+- Telecommunication of multimedia data.
+- Broadcast of multimedia data.
+- Wide range of data volumes and transfer rates.
+- Access control, security.
+- Tariffing.
+- Copyright, licensing.
+- Wide range of support materials.
+- Use of a wide range of terminals and workstations, including devices with minimal resources.
+- Minimal resources: Facilities that the interchange form must provide in order for a given set of objects, running in limited resources environments, to meet their functional specification as determined by the designer.
+- Ease of specification: For specifying the minimum recommended resources needed by the MHEG application.
+- Ease of application: Minimum requirements of an application should be easily recognised by the negotiation process.
+- Flexibility: The mechanism should be reliable across a broad range of system configurations and media formats.
+- Informative rather than restrictive: The using application should have the final determination as to whether a given set of objects can be interpreted.
+- Extensible/open: The representation should function correctly as New formats, classes, and application-dependent parameters are added.
+- Scalability: Trade-off among different application platform capabilities, for example, resolution enhancement relative to presentation time.
+- Composition: The minimum resource requirements for a given MHEG application should be combinable in some consistent and predictable manner when applications are combined.
+- Graceful degradation: The primary concern of minimal resource systems is the manner in which degradation can be handled; an application should be able to express its policy with regard to this issue, for example, by using scalability and related mechanisms.
+- Real-time interchange and presentation.
+- Object placement optimisation: Objects that are likely to be accessed simultaneously are adjacent from the standpoint of the access mechanism.
+- Progressive access of objects: Images may be retrieved and presented in increasing resolution for systems with significant presentation delay; scalable versions of objects may be represented and retrieved for systems with insufficient resources for full fidelity presentation.
+- Partial object retrieval: Large objects may be retrieved in several portions, since the entire content will not be presented at one time.
+- Object sequencing: The order in which objects are expected to be presented should be used by the access mechanism when insufficient throughput would lead to unacceptable delays for the whole object to be interchanged.
+
+- Separate retrieval of object description and object content: The object description should be retrieved without necessarily retrieving the content so that the system can use information about a set of objects to optimise the access for this set and resources needed for the access can be prepared.
+- Global object index: A table of all objects and their position in an object set should be provided to support fast lookup of objects.
+- Object interleaving: Objects that are to be retrieved simultaneously may be interleaved so that large objects do not cause delays for other objects.
+- Resource requirements: Those for retrieval and presentation by the target system should be available by lookup rather than by derivation.
+- Aggregate retrieval: A collection of objects can be aggregated so that they can be retrieved by one step rather than through a series of requests.
+- Ability to reference individual media objects internally and externally.
+- Ability to navigate in a hypermedia fashion.
+- Ability to support arbitrary hyperlink transversal schemes.
+
+These requirements can be summarised in a set of generic needs:
+
+- application designers and distributors require application portability in a multi-vendor environment;
+- applications must handle multimedia information structured in such a way that real-time interactivity (including acquisition of multimedia data), as well as real-time interchange of multimedia data can be ensured;
+- applications must compose and synchronise multimedia data in space and time;
+- applications must be able to define links between multimedia data elements;
+- applications must be able to reuse multimedia data by integration in different contexts;
+- applications must be able to frequently update the multimedia data, as well as to manipulate a set of data elements;
+- applications must be able to be interpreted on different systems, from minimal resources to non-limited resources systems;
+- applications must be interchanged and presented in real-time.
+
+These requirements have led to the definition of this Recommendation for multimedia and hypermedia information.
+
+### **0.3 Rationale for standardisation of multimedia and hypermedia information**
+
+The rationale for a standard defining multimedia and hypermedia information structures is based on the following considerations.
+
+- Standardisation, only at the level of monomedia information is not sufficient to guarantee application portability. Applications do not use the monomedia data separately but must define an associated set of parameters that are necessary for presentation. (Such parameters may include identification of the encoding algorithm applied to the data, decoding parameters relevant to the data, optional attributes to be used for presentation).
+- Standardisation, only at the level of monomedia information, is not sufficient for the design and interchange of multimedia and hypermedia information. Multimedia and hypermedia applications rely on abstractions or data structures that provide features such as synchronisation links and logical links between monomedia data.
+- The design and management of multimedia and hypermedia applications in distributed environments will be eased if the internal details of the information presentation are masked from the application by the use of appropriate abstractions. The application should deal only with functions such as management of information distribution, scheduling of presentation, management of the user dialogue, and other high-level activities.
+
+This Recommendation aims to provide generic multimedia/hypermedia information structures that fulfil these requirements and additionally are suited to:
+
+- real-time presentation using multimedia presentation and synchronisation facilities available on the application platform;
+- real-time interchange using communication facilities available on the application platform;
+- final-form representation in which the information is represented and coded for direct presentation without requiring additional processing of its structure.
+
+## 0.4 T.171 Objectives
+
+### 0.4.1 Interchange
+
+This Recommendation is intended to provide interchange facilities for various media types. The media data may be encoded according to other international standards, e.g. JPEG for still image, MPEG for video, or may be encapsulated using private and proprietary coding techniques. The interchange units defined by this Recommendation are handled by the MHEG engine under the control of a using application.
+
+In order to support multimedia interchange, as opposed to the interchange of multiple media, this Recommendation provides structures for the composition of different media types within a single unit of interchange.
+
+### 0.4.2 Presentation
+
+This Recommendation is intended to support final-form presentation of multiple media types. This Recommendation provides facilities for the identification of the coding technique to enable the use of the appropriate presentation resources on a specific platform.
+
+In order to support multimedia presentation, as opposed to the presentation of multiple media, this Recommendation provides structures for the composition of different media types in a presentation. This composition takes the form of time sequencing, spatial positioning, and logical interaction between the media.
+
+In addition, this Recommendation supports interaction with, and modification of, media data and its associated presentation attributes, e.g. size, position, and volume.
+
+Figure 0.1 illustrates the use of this Recommendation as an interchange unit and as an identifier of multimedia information encoded according to several International Standards.
+
+![Diagram illustrating the use of Recommendation T.171 for interchange and identification of multimedia information. A large container box holds four smaller boxes, each representing a different media type: JPEG, JBIG, MPEG, and TEXT. Each smaller box contains a small square icon and a label. The diagram is labeled T0825480-96/d001.](d79d33da852cb7bca3e87b400a15c3e8_img.jpg)
+
+The diagram shows a large rectangular container box with a handle on top. Inside this container, there are four smaller rectangular boxes arranged in a 2x2 grid. Each of these smaller boxes also has a handle on top and contains a small square icon on the left and a label on the right. The labels are 'JPEG', 'JBIG', 'MPEG', and 'TEXT' from top-left to bottom-right. The entire diagram is labeled 'T0825480-96/d001' at the bottom right.
+
+Diagram illustrating the use of Recommendation T.171 for interchange and identification of multimedia information. A large container box holds four smaller boxes, each representing a different media type: JPEG, JBIG, MPEG, and TEXT. Each smaller box contains a small square icon and a label. The diagram is labeled T0825480-96/d001.
+
+**Figure 0.1/T.171 – Recommendation T.171 for interchange and identification of multimedia information**
+
+### 0.4.3 Minimal resources
+
+This Recommendation is intended to support the specification of the minimal resources required to present the encoded data and provides facilities for the interchange of information relating to these resources, which is provided by the information source.
+
+### 0.4.4 Real time
+
+This Recommendation is intended to ease the real-time interchange of multimedia information and provides facilities to assist a using system to achieve an adequate information flow.
+
+## 0.5 T.171 concepts
+
+This subclause provides a general introduction to the T.171 concepts. The following concepts are presented:
+
+- **MHEG classes; MHEG objects:** This Recommendation is a standard that defines object classes. From these classes, MHEG objects may be instantiated by the object designer (e.g. a computer program) and interchanged between using applications. Any number of MHEG objects may be instantiated from a given MHEG class.
+- **Run time objects (rt-objects):** The MHEG model class is an MHEG abstract class, which provides the following MHEG classes: script, content, multiplexed content, and composite classes. From these model classes, model objects may be instantiated by the object designer and interchanged. In order to reuse the data interchanged in the model objects in different contexts, the object designer is able to create run-time objects, also called rt-objects, from a given model object: for example, the same data in a content object may be presented twice at the same time with different sizes using two rt-content objects, but the content object will be interchanged only once. Any number of rt-objects may be created from a given model object by the object designer.
+- **Channels:** This Recommendation defines logical spaces in which the rt-objects are presented by the user.
+
+### 0.5.1 Object orientation
+
+This Recommendation defines a classification of structures corresponding to units of multimedia/hypermedia information to be interchanged. This classification is based on an analysis of the common behaviour and properties of multimedia/hypermedia information and takes the form of an object-oriented approach to the standardisation. This approach results in autonomous and reusable information structures that are generic to multimedia/hypermedia applications.
+
+In the context of this Recommendation, the term “class” denotes a structure of interchangeable multimedia/hypermedia information from which MHEG objects can be instantiated. This Recommendation makes use of the object-oriented mechanism of deriving subclasses from existing ones, together with the associated concept of inheritance. However, since MHEG objects have to be considered as data rather than executable code, no interference MHEG objects in the form of method signatures is defined.
+
+It should be understood that the use of an object-oriented approach to the definition of MHEG structures, does not imply that a system interpreting these structures must be based upon this approach. While this Recommendation defines an interchange format for multimedia/hypermedia information, it makes no assumptions about the internal representation of MHEG structures or the design of systems, engines, interpreters, tools, or using applications.
+
+The MHEG classes contain a level of complexity that is appropriate for use as generic structures in a wide range of using applications and domains. It is assumed that the semantics associated with the use of MHEG classes are defined at the application level and not at the level of this Recommendation. When using applications interchange multimedia/hypermedia information, they usually rely on interchange Services, which provide the appropriate support for the interchange of data. There are various levels of complexity of data interchange, as shown in Figure 0.2.
+
+In Figure 0.2, applications A and B may be seen as a single application by the user.
+
+Figure 0.2 shows interchange between using applications A and B and identifies the levels at which this interchange takes place.
+
+- Application level: This exchange (Appl) is not covered by this Recommendation. The using application may make use of a script interchange Standard at the next lower layer.
+- Script level: This exchange (S) is covered by ISO/IEC 13522-3 and other Standards for hyperdocument and scriptware interchange and may make use of the MHEG object interchange Standard at the next lower layer.
+- MHEG object level: This exchange (M) is the subject of this Recommendation. It makes use of Recommendations and Standards for the interchange of content data.
+- Non-MHEG content data level: This exchange (C) is addressed by individual monomedia Recommendations and Standards.
+- Other protocol element level: This exchange (OPE) of elements such as messages and acknowledgements is required by the application but is not addressed by this Recommendation.
+
+This model also shows the need to address the binding of the script to the MHEG objects and of MHEG objects to the content data.
+
+![Diagram of the Multimedia/hypermedia interchange model showing five levels of interchange between two applications, A and B.](e180f2b5fcbe8001554a7c0677cd3f82_img.jpg)
+
+The diagram illustrates the Multimedia/hypermedia interchange model. It shows two applications, A and B, interacting at five levels. The levels are represented by boxes in the center, with arrows indicating the flow of data between the applications and the interchange level. The levels are: Application (Appl), Script (S), MHEG object with its content data (M), Non-MHEG content data (C), and Other protocol element (OPE). The interchange levels are connected by a vertical line, indicating a hierarchical relationship. The diagram is labeled T0825490-96/d002.
+
+```
+
+graph TD
+    subgraph A [A]
+        A1[Application]
+        A2[Script]
+        A3[MHEG object with its content data]
+        A4[Non-MHEG content data]
+        A5[Other protocol element]
+    end
+    subgraph Interchange [Interchange]
+        I1[Appl]
+        I2[S]
+        I3[M]
+        I4[C]
+        I5[OPE]
+    end
+    subgraph B [B]
+        B1[ ]
+        B2[ ]
+        B3[ ]
+        B4[ ]
+        B5[ ]
+    end
+    A1 <--> I1
+    I1 <--> B1
+    A2 <--> I2
+    I2 <--> B2
+    A3 <--> I3
+    I3 <--> B3
+    A4 <--> I4
+    I4 <--> B4
+    A5 <--> I5
+    I5 <--> B5
+    I1 --- I2
+    I2 --- I3
+    I3 --- I4
+    I4 --- I5
+
+```
+
+Diagram of the Multimedia/hypermedia interchange model showing five levels of interchange between two applications, A and B.
+
+**Figure 0.2/T.171 – Multimedia/hypermedia interchange model**
+
+## 0.5.2 Encoding
+
+This Recommendation provides a coded representation of each MHEG class. Instances of these coded representations are MHEG objects and represent the data to be interchanged and presented by multimedia/hypermedia applications.
+
+The base-coded representation makes use of Recommendation X.680 “Specification of Abstract Syntax Notation One” (ASN.1) and Recommendation X.690 “Specification of Basic Encoding Rules for ASN.1” and is described in this Recommendation.
+
+Alternative coded representations may be provided. Their coded representation should be isomorphic to the base-coded representation. These different notations and encoding schemes are alternatives used to express the same and unique representation of the MHEG objects.
+
+### 0.5.3 Overview of the MHEG classes
+
+The classes defined in this Recommendation can be used to specify:
+
+- objects containing media information;
+- relationship between objects;
+- dynamic behaviour of objects;
+- information to optimise the real-time handling of objects.
+
+The following instantiable classes are defined in this Recommendation.
+
+#### 0.5.3.1 Content class
+
+The content class is a model class; it contains or refers to the coded representation of media information together with a parameter set containing information required for content presentation. This parameter set contains an identification of the coding method and a field for the specification of application-oriented parameters (e.g. fonts and colour table). The content class also specifies the original size, duration and volume of the data. These values are expressed using generic space and temporal units. From content class, multiplexed content objects can be derived; content objects that are not multiplexed are called pure content object or non-mux content object.
+
+#### 0.5.3.2 Multiplexed content class
+
+The multiplexed content class is a model class that is a subclass of the content class. It contains or refers to the coded representation of a multiplexed media data together with a description of each multiplexed stream.
+
+#### 0.5.3.3 Composite class
+
+The composite class is a model class; it provides the support for associating multimedia and hypermedia objects. This mechanism provides a consistent approach to the linking and synchronisation in time, space, of a set of objects. This class also provides a logical structure to describe the list of possible interactions offered to the user, but does not define the interaction facilities provided by the user interface. Such interaction may be achieved in a variety of ways, e.g. graphical user interface and keyboards. This Recommendation does not define the look and feel of multimedia interactive presentations, nor does it propose to change or add concepts to those existing in typical graphical user interfaces. As this Recommendation is generic and independent of platform and implementation, it describes interaction at a virtual level. It is for a using application to apply these mechanisms using its specific look and feel.
+
+#### 0.5.3.4 Action class
+
+This Recommendation provides an initial behaviour for each MHEG object, run-time object (rt-object), and channel, e.g. default position of an rt-content and provides also a means to modify the initial behaviour of each object by defining a list of elementary actions to be applied to the objects. The modification of the behaviour is achieved by interchanging the corresponding elementary actions within action objects. The action objects are used within a link object to describe the link effect.
+
+The action class defines a structure that specifies a synchronised set of elementary actions to be applied to one or more targets.
+
+#### 0.5.3.5 Elementary actions
+
+This Recommendation defines elementary actions that can affect the following behaviours of an MHEG object, an rt-object, or a channel.
+
+- **Preparation:** Actions are provided to control the availability of the MHEG object in the system. For example, Prepare and Destroy actions may be applied to add and remove an MHEG object from the system.
+- **Creation of run-time objects (rt-objects):** The New action is provided to create rt-objects (rt-script, rt-component) from a model object (script, component); the Delete action is provided to destroy them.
+
+**Presentation:** Actions are provided to control the progress of the rt-components in the system. For example, Run and Stop actions may be applied to control the progression of a time-based rt-component.
+
+- **Rendition:** Actions are provided to control the projection of the rt-component on the system. These actions vary according to the media type. For example, Set GTF action to change the presentation speed for time-based media and Set OVS action to change the presentation size for visible media.
+- **Interaction:** Actions are provided to control the results of interaction with an rt-component in the system. For example, Set Interaction Ability action specifies the selectability and the modifiability of an rt-component.
+- **Activation:** Actions are provided to control the activation of the rt-scripts in the system. For example, Run and Stop actions.
+
+#### 0.5.3.6 Get actions
+
+This Recommendation also defines a means to retrieve the behaviour of an MHEG object, an rt-object or a channel. Actions are provided to get the behaviour attribute or status value of MHEG objects, rt-objects and channels. These actions are called “get actions”. The result of a get action is a generic value or the value “undefined” when an error condition occurs. The get actions are used to express the source and the comparison value of the link condition in a link object or as any parameter of an elementary action.
+
+#### 0.5.3.7 Link class
+
+The link class defines a structure that specifies a set of relationships. Each relationship is defined between one or more sources and one or more targets. The relationship is composed of conditions associated with the sources (link condition) and actions to be applied to the targets (link effect). The actions, which are described in action objects, are to be applied to the targets when the conditions are satisfied.
+
+The source and target can be instances of any MHEG class, including link class and action class. The source and targets can also be any run-time objects.
+
+Instances of the link class are used to specify the time sequencing, spatial positioning, or logical interaction between MHEG objects and run-time objects.
+
+#### 0.5.3.8 Script class
+
+The script class is a model class. It defines a container for complex relationship between MHEG objects, run-time objects and channels, specified in a script language. This Recommendation does not define the script language itself but provides the script class to encapsulate a script and an indication of the language used.
+
+It is assumed that the script language used in a script object is able to reference MHEG objects, rt-objects, and channels, and also to access their attributes. Recommendation T.174 defines an interface to MHEG entities for this purpose and Recommendation T.173 defines a Script interchange Format.
+
+#### 0.5.3.9 Descriptor class
+
+The descriptor class defines a structure for the interchange of resource information about a single or a set of other interchanged objects. The described objects are called “related” objects. The information can be used to facilitate a correspondence between the resources required to present the objects and the resources available to the system, or to perform a negotiation between the source of the MHEG objects and the presentation site.
+
+#### 0.5.3.10 Container class
+
+The container class provides a means to regroup multimedia and hypermedia data in order to interchange them as a whole set.
+
+### 0.5.4 Run-time objects (rt-objects)
+
+For the purpose of reusing model objects (script, component objects) in different presentations or activation, a clear separation is made between the interchanged model object, which contains the reusable data or composition, and the rt-object corresponding to a specific view of the model data or composition.
+
+The rt-objects (rt-script, rt-content, rt-multiplexed content, and rt-composite objects) are created by the object designer using the MHEG action New. The presentation or activation of an rt-object does not affect the model object; this allows the reuse of a same model object in different rt-objects.
+
+### **0.5.5 Channels**
+
+A channel is a logical space in which the rt-components (rt-content and rt-composite objects) are presented and perceived by the user. The channels are created by the object designer using an MHEG action. The object designer may provide information in the descriptor object to facilitate the mapping by the MHEG engine of the logical channels to the real world.
+
+## **0.6 The MHEG application interface**
+
+This Recommendation does not define an Application Programming Interface (API) for the handling of objects in a system. However, it is assumed that the MHEG engine provides facilities to support the actions defined in this Recommendation for use by the using application.
+
+## **0.7 T.171 extensibility**
+
+The scope of the classes defined in this Recommendation is compatible with their use in a wide range of applications and domains. It is recognised that certain applications may require specific functionality not directly provided by the classes, e.g. a using application may require the use of specialised resources available on a given platform. In this case, additional resources, which are not provided directly by this Recommendation, may be associated with the MHEG objects. This association is defined by using one of the following techniques. These techniques do not change the coded representation of the facilities defined by this Recommendation (see clause 15):
+
+- 1) extension of elementary actions;
+- 2) extension of attributes of an MHEG object, an rt-object or a channel;
+- 3) extension of data types, classifications, styles, events, channel media types;
+- 4) addition of new object classes.
+
+NOTE – This facility may be used for example to create and manipulate new attributes such as payment or colour, or to vary some speech modulation parameter in an audio object.
+
+For 1) through 3), a registration procedure and catalogues are provided by ISO/IEC 13522-4. This allows users to define extensions without significant reduction of portability. This extension allows users to use proprietary or registered catalogues (see clauses 14 and 15.1). An MHEG engine can take any catalogue entry into account and thereby introduces the New extension process; another MHEG engine with no extensions may ignore the extension.
+
+The addition of New object classes implies an appropriate adaptation of MHEG engine for interpretation of the new classes, which limits the usage of MHEG objects of these classes to that MHEG engine.
+
+# **1 Scope**
+
+The scope of this Recommendation is the coded representation of final-form multimedia and hypermedia information objects that will be interchanged as units within or across services and applications, by any means of interchange (e.g. storage, local area network, wide area telecommunication, broadcast telecommunications or broadcast networks). These objects define the structure of a multimedia presentation.
+
+These objects, hereafter called MHEG objects, provide the following functionalities supporting for:
+
+- final-form representation;
+- systems with minimal resources;
+
+- interactivity and multimedia synchronisation;
+- real-time presentation;
+- real-time interchange,
+
+as a common base for many multimedia and hypermedia applications.
+
+This Recommendation defines the specifications of MHEG objects common to all types of coded representation and also defines one type of coded representation, the base-coded representation.
+
+## **1.1 Specificity of the scope**
+
+Since it is expected that a wide range of recommendations, standards, and user applications will be users of this Recommendation, the scope focuses on the generic structuring aspects. This Recommendation recognises the semantics implied by the specification of the MHEG objects but does not enforce any semantic interpretation by the using application.
+
+## **1.2 Issues outside T.171 scope**
+
+The scope excludes any standardisation of models, services, systems, protocols or applications that are likely to make use of MHEG objects. Integration of MHEG objects within these models, services, systems, protocols or applications, or interworking, are defined by other standardisation bodies within JTC1 or ITU-T. The generic part of the interface between MHEG objects and applications was defined through liaison and cooperation with those bodies.
+
+The coded representation of content data is not in the scope of this Recommendation.
+
+# **2 Conformance**
+
+The conformance is evaluated on interchanged objects. There is no consideration of conformance for a system, an engine, a process.
+
+An interchanged object is conformant if it can be correctly interpreted. This means that:
+
+- its ASN.1 encoding is correct (conformance of the concrete syntax);
+- its ASN.1 notation is conformant to the grammar specified in this Recommendation (conformance of the abstract syntax).
+
+A conforming MHEG decoder shall recognise and decode all MHEG objects as defined in this Recommendation.
+
+## **2.1 Profiles**
+
+Profiles may be provided by the using applications.
+
+## **2.2 Syntax**
+
+Conformance is on the base representation (this Recommendation). An MHEG object instance is represented using the ASN.1.
+
+Conformance at the level of the coded representation is ensured by the use of international standards for the encoding of the syntax.
+
+## **2.3 Semantics**
+
+This Recommendation provides an encoded representation for expressing an expected behaviour of objects, such as relationship in time and space, but does not define techniques that might handle such relations between the objects.
+
+### 3 Normative References
+
+The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; all users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published.
+
+- ITU-T Recommendation X.680 (1994) | ISO/IEC 8824-1:1995, *Information technology – Abstract Syntax Notation One (ASN.1): Specification of basic notation*.
+- ITU-T Recommendation X.681 (1994) | ISO/IEC 8824-2:1995, *Information technology – Abstract Syntax Notation One (ASN.1): Information object specification*.
+- ITU-T Recommendation X.682 (1994) | ISO/IEC 8824-3:1995, *Information technology – Abstract Syntax Notation One (ASN.1): Constraint specification*.
+- ITU-T Recommendation X.683 (1994) | ISO/IEC 8824-4:1995, *Information technology – Abstract Syntax Notation One (ASN.1): Parameterization of ASN.1 specifications*.
+- ITU-T Recommendation X.690 (1994) | ISO/IEC 8825-1:1995, *Information technology – ASN.1 encoding rules: Specification of Basic Encoding Rules (BER). Canonical Encoding Rules (CER) and Distinguished Encoding Rules (DER)*.
+- ITU-T Recommendation X.691 (1995) | ISO/IEC 8825-2:1995, *Information technology – ASN.1 encoding rules – Specification of Packed Encoding Rules (PER)*.
+- ISO/IEC 13522-4:1996, *Information technology – Coding of multimedia and hypermedia information – Part 4: MHEG registration procedure*.
+
+### 4 Definitions
+
+For the purposes of this Recommendation the following definitions apply.
+
+- Definitions as in Recommendations X.680 and X.690.
+- Definitions in this clause.
+
+**4.1 abstract class:** An MHEG class that cannot be instantiated, i.e. no interchanged objects. These classes encapsulate information and provide inheritance of attributes in its subclasses, and also act as a mechanism for specifying which MHEG actions may be applied to which MHEG classes.
+
+**4.2 action:** An elementary action or a get action.
+
+**4.3 action effect:** Equal to the concatenation of the MHEG effect and the user effect for all elementary actions. For get actions, it is equal to the MHEG effect.
+
+**4.4 action object:** An instance of an MHEG class that defines an organised set of elementary actions.
+
+**4.5 activate; (active):** An elementary action that causes a link object to become active, i.e. only an active link can be fired.
+
+**4.6 alias:** An attribute that can be associated to an MHEG entity, a data, or a stream. It is used as an alternative identification.
+
+**4.7 anchor:** A content object containing anchor information rather than media data. Anchor information is used to position an anchor against a hub document.
+
+**4.8 attribute:** Typed value representing some characteristics of an interchanged MHEG object, an rt-object or a channel.
+
+**4.9 author; object designer:** A computer program or other devices when the objects are generated by mechanical or electronic means.
+
+**4.10 channel:** A logical device in which rt-components are positioned for final presentation. Channels are mapped by an MHEG engine to physical devices like screen windows or loudspeakers for making the rt-objects within them perceivable by the user.
+
+- 4.11 coded representation:** Binary representation of the structure and data within an object instance.
+- 4.12 component object:** An instance of an MHEG class that represents a content object, a multiplexed content object, or a composite object.
+- 4.13 composite object:** An instance of an MHEG class that defines a list of composition elements grouped for presentation. The presentation of a composite object consists of the presentation of its composition elements.
+- 4.14 composition elements:** An attribute of the MHEG composite class that defines its presentation and its subhierarchy.
+- 4.15 constraint condition:** A part of a link condition describing an attribute and a status value. It is referred as an additional condition if trigger conditions within a same link are satisfied.
+- 4.16 container object:** An instance of an MHEG class that defines a list of objects grouped for interchange. It provides a means to group objects without specifying specific relationship.
+- 4.17 content object:** An instance of an MHEG class that provides a consistent structure for the interchange of encoded generic value or any presentation data. It is either a non-mux-content or a multiplexed content.
+- 4.18 data:** Attribute of content and script object.
+- 4.19 default channel:** A channel that is always available to the MHEG engine by the use of a reserved identifier (that is, “Default-Channel”). The elementary actions “New channel” and “Delete channel” are ignored for the default channel. When a root rt-component is not assigned to a specific channel, it is implicitly assigned to the default channel.
+- 4.20 delete; delete channel, (not available):** An elementary action that removes an rt-object or a channel from an MHEG engine. The rt-object or the channel is said to be not available.
+- 4.21 demultiplex:** A means to extract two or more streams of information from one unique combined encoding scheme to achieve separate presentation or exchange.
+- 4.22 descendant:** Any MHEG entity contained in the subhierarchy of which the initial object is the root.
+- NOTE – The graph of the descendancy may contain loops. An entity may be a descendant of itself.
+- 4.23 descriptor object:** An instance of an MHEG class that defines the associated information to any object. A using application may use this object to negotiate characteristics of MHEG engines.
+- 4.24 destroy, not ready, not available:** An elementary action that removes an MHEG object from an MHEG engine. The object is said to be not ready or not available.
+- 4.25 elementary action:** Used to modify the behaviour of an MHEG entity within the MHEG engine. Elementary actions are interchanged within action objects. An elementary action is typically composed of a target set, specific parameters defined for each elementary action, and an optional transition duration.
+- NOTE – Examples of elementary actions: Prepare (target set), Run (target set, number of performances).
+- 4.26 empty socket:** A socket in which no rt-component has been plugged.
+- 4.27 event:** A signal generated by some components or the MHEG engine, e.g. key stroke, mouse movement.
+- 4.28 final form:** An interchange form intended for presentation without requiring change of the structure of the objects.
+- 4.29 fire a link:** Each time a link condition of an active link is satisfied, the link is fired, that is, its link effect is processed.
+
+**4.30 generation:** A composite object has several sockets where component objects are attached. These component objects has the sibling relationship. Therefore, a composite object is said to define one generation of component objects. Several generations may be made if another composite objects are attached in the sockets. As an rt-composite is created from a composite object, an rt-composite also defines some generations.
+
+**4.31 generic value:** One of generic boolean, generic numeric, generic integer, generic ratio, generic string, generic reference, or generic list. It may be a constant or an evaluated value.
+
+**4.32 get action:** Targeted to an MHEG entity and specifies the requested attribute or status value to be evaluated. The result of a get action is to provide a generic value. This generic value is used in the context of the evaluation and is a local value. If the same get action is processed in two different links in parallel, there are two generic values resulting from these two evaluations. These two generic values may be different. A get action can be used and interchanged when a value is allowed, for example, as a parameter of an elementary action or a get action, as a source value or comparison value in a link object.
+
+NOTE – Examples of get actions: Get Preparation Status (target) and Get Running Status (target).
+
+**4.33 hook:** An attribute of the content class and script class containing encoding and decoding information enabling the use of data. The semantics of these parameters are not defined by this Recommendation but are given by the semantics of the data encoding Standard or Recommendation.
+
+**4.34 hypermedia:** The ability to access monomedia and multimedia information by navigating across links.
+
+**4.35 interchange attribute:** An attribute of an interchanged MHEG object.
+
+**4.36 interchange medium:** The medium used to interchange data: it can be a storage medium, a transmission medium, or a combination.
+
+**4.37 interchange value:** The value of an interchanged attribute.
+
+**4.38 label:** A generic string that is associated with an element of a composite. When an rt-composite is created from the composite object, an rt-content is created from this label and automatically plugged into a corresponding socket.
+
+**4.39 link condition:** Conditions to be satisfied in order to fire a link. It is composed of some trigger conditions, some constraint conditions and some logical operators between them.
+
+**4.40 link effect:** Effects of a link when it is fired. It is composed of some elementary actions and/or some action objects.
+
+**4.41 link object:** An instance of an MHEG class that defines spatio-temporal or conditional relationship between MHEG entities. A link object is composed of a link condition and a link effect.
+
+**4.42 macro action:** An action object that offers the facility to replace the parameters in frequently used action objects.
+
+**4.43 macro link:** A link object that offers the facility to replace the parameters in frequently used conditional actions.
+
+**4.44 macro parameter:** A parameter of an action or an attribute of the action class that is replaced by the following information: a macro definition identifier and a default macro usage value.
+
+**4.45 macro usage value:** Within the link effect of a link object, a usage value can be provided for each macro parameter used within the link effect. This assignment is processed when the link is fired.
+
+**4.46 medium (plural media):** A means by which information is perceived, expressed, stored, or transmitted.
+
+![Diagram illustrating the relationships between different meanings of media. The top row shows four interconnected components: 'Interchange (storage or transmission) systems', 'MHEG objects', 'Output and input systems', and 'User'. These are connected by double-headed arrows. Below each component is a corresponding media type: 'Interchange media (storage or transmission)', 'Representation media', 'Perception media', and 'Presentation media'. Vertical lines connect each top component to its respective media type below it. The diagram is labeled T0825500-96/d003 in the bottom right corner.](5414f65867392f05ba0063b208eeb5e1_img.jpg)
+
+```
+graph LR; A[Interchange (storage or transmission) systems] <--> B[MHEG objects]; B <--> C[Output and input systems]; C <--> D[User]; A --- E[Interchange media (storage or transmission)]; B --- F[Representation media]; C --- G[Perception media]; D --- H[Presentation media];
+```
+
+T0825500-96/d003
+
+Diagram illustrating the relationships between different meanings of media. The top row shows four interconnected components: 'Interchange (storage or transmission) systems', 'MHEG objects', 'Output and input systems', and 'User'. These are connected by double-headed arrows. Below each component is a corresponding media type: 'Interchange media (storage or transmission)', 'Representation media', 'Perception media', and 'Presentation media'. Vertical lines connect each top component to its respective media type below it. The diagram is labeled T0825500-96/d003 in the bottom right corner.
+
+**Figure 1/T.171 – Relationships between the different meanings of media**
+
+Figure 1 is intended to clarify the relationship between the different meanings of the term “media”. Representation and presentation media are to be differentiated for virtuality and portability (device independence) purposes. A given character string (coded representation) can be presented using different means (screen, paper, loudspeaker after text-to-speech synthesis). The same command can be input by the user through different equivalent means (for example, selection in a list with a mouse, a tactile screen, with digits plus validation key, with a keyboard to input the corresponding character string, or even through a microphone with a voice recognition system allowing recognition of a limited vocabulary including the name of the above-mentioned command.).
+
+NOTE – This is a weak definition because this term has different meanings depending on the context. Thus, the term is to be avoided in its stand-alone form. To be unambiguous, it should be only used in expressions such as perception medium, representation medium, presentation medium, storage medium, transmission medium.
+
+**4.47 MH object class:** An MHEG object class that is the root of MHEG class hierarchy. It defines attributes common to all other MHEG classes.
+
+**4.48 MHEG class:** An MHEG object class defined by this Recommendation.
+
+**4.49 MHEG effect:** The effect caused by the processing of an elementary action or a get action, which changes or retrieves some internal state.
+
+**4.50 MHEG engine:** A pseudo-mechanism that may consist of a process or a set of processes that interpret MHEG objects encoded according to the encoding specifications of this Recommendation.
+
+NOTE – The way of implementing the MHEG engine is outside the scope of this Recommendation does not define any ingredients inside the MHEG engine.
+
+**4.51 MHEG entity; entity:** Any MHEG object, rt-object, or channel.
+
+**4.52 MHEG object:** A coded representation of a multimedia and/or hypermedia object that conforms to this Recommendation.
+
+**4.53 minimal resources:** A system with minimal buffering capacity, minimal throughput of communication channels, limited computational power.
+
+**4.54 model object:** An instance of an MHEG class that represents a script object or a component object.
+
+**4.55 multimedia representation:** The property of handling several types of representation media.
+
+NOTES
+
+1 – The term multimedia is an adjective; it shall be used attached to a noun that provides the context (e.g. multimedia service or application, multimedia terminal, multimedia network, multimedia presentation).
+
+2 – In this Recommendation, multimedia is used in the sense of multiple representation media. Hence, a remote processing service or videotex, using a keyboard and a textual display, is not multimedia, as the interaction involves only one medium (text).
+
+3 – An MHEG object within a multimedia service or application may contain only one representation medium.
+
+**4.56 multiplex:** A means to combine two or more streams of information into one unique encoding scheme to achieve simultaneous presentation or exchange.
+
+**4.57 multiplexed content object:** An instance of an MHEG class that provides a single consistent structure for the interchange of any multiplexed presentation data.
+
+**4.58 new, new channel, available:** An elementary action which causes an rt-object or a channel to become available to the MHEG engine for further processing (e.g. presentation). The rt-object or the channel is said to be available.
+
+**4.59 non-mux content object:** A pure content object, that is, not a multiplexed content object.
+
+**4.60 null:** A specific value indicating nothing.
+
+**4.61 null data:** Null data is generated by the MHEG engine when referenced by the use of a reserved identifier: “Null-Data”. The null data may replace any kind of data. Actions performed on an rt-script/rt-content made from a script object/content object with a null data are not ignored. The user effect of such action is defined by the hook and classification information provided in the model object.
+
+**4.62 null MHEG object:** A null object is generated by the MHEG engine when referenced by the use of a reserved identifier: “Null-MH”. The null object may replace any object of any MHEG class. An action performed on a null MHEG object causes a null effect.
+
+**4.63 null root rt-object:** A null root rt-object is generated by the MHEG engine when referenced by the use of a reserved identifier: “Null-Root-Rt”. The null root rt-object may replace any root rt-object. An action performed on a null root rt-object causes a null effect.
+
+**4.64 object:** A finite, independent, self-defining piece of information that can be manipulated as a whole by MHEG engines and interchanged as one unit.
+
+NOTES
+
+1 – Within the context of this Recommendation, the object can be of multiple types (e.g. action, link, script, content, composite, descriptor, or container object).
+
+2 – “Self-defining” implies that the object contains or refers to the information necessary for its handling.
+
+3 – The definition is not restricted to digitally-coded objects, but may also be applied to analogue objects (e.g. a videodisk sequence).
+
+**4.65 object class:** Any category of objects that have a specific and homogeneous template (that is, characteristics and behaviour as relevant to the contained information and to their actions modifying their behaviour).
+
+**4.66 parent-child relationship:** Relationship existing when the parent object is a composite object that contains or refers to a child object.
+
+**4.67 perception medium:** The nature of the information as perceived by a human being (e.g. speech, noise, music, text, drawings, moving, scenes).
+
+**4.68 plug:** An elementary action that attaches an rt-component into a socket.
+
+**4.69 prepare; prepared; ready:** An elementary action that causes an object to become available to the MHEG engine for further processing (e.g. presentation). The object is said to be prepared or ready.
+
+- 4.70 presentation:** The rendition of an rt-component to be perceived by an user.
+- 4.71 presentation media:** The means used to reproduce information to a user on an output device (e.g. screen, paper, printer, loudspeaker) or to acquire information from a user with an input device (e.g. keyboard, mouse, microphone, camera).
+- 4.72 presentation space:** The space used to present rt-components to the user. It consists of a temporal axis, three dimensional spatial axes and an audible volume range.
+- 4.73 projection:** A presentation space of a socket may be mapped into the presentation space of its parent or a channel presentation space, changing its temporal position, size or volume. The mapping is called projection. A root rt-component is always projected into a channel presentation space. A number of elementary actions are used to achieve such projection.
+- 4.74 real-time interchange:** The ability to interchange objects between systems within deadlines needed for the presentation schedule to be satisfied. This implies a constant limited delay. Specifically, time-based media and time-synchronised objects have presentation requirements that may not be satisfied by the buffering.
+- 4.75 real-time presentation and interaction:** The ability to present objects within a constant delay. Intrinsically time-based (e.g. audio, video) objects or objects that have time-behaviour or time-constraints (e.g. synchronisation) are concerned.
+- 4.76 real-time system:** To perform operations in a way that gives the user the impression of happening immediately. A real time system means a system with only constant delay. In a wider sense a limited delay and jitter could be accepted. In the context of certain media (e.g. audio, video), real time implies a presentation that meets the original time base requirements.
+- 4.77 render:** The ability to show a certain object in a specific way to the user. A number of elementary actions are used to achieve such specific rendering.
+- 4.78 representation medium:** The type of the interchanged data that defines the nature of the information as described by its coded form.
+
+#### NOTES
+
+1 – Examples of representation media information and their possible coded forms:
+
+- Characters or text: Telex, ASCII, EBCDIC.
+- Graphics: CEPT, NAPLPS or CAPTAIN videotex, CGM.
+- Audio: Recommendation G.711, MIDI, MPEG Audio.
+- Still picture: Fax group 3, JBIG, JPEG.
+- Audio visual sequence: CCIR Recommendation 601 plus associated audio: MPEG.
+
+2 – The representation medium is defined independently of the direction of interchange (i.e. to or from the user or between equipment). Each representation medium may be used for both input or output, e.g. character-type representation may be used for both text display and text input from a keyboard; graphics-type representation may be used for both graphic display and graphic input (location) from a mouse. Audio-type or picture-type representations may be used both for reproduction and capture.
+
+- 4.79 representation of an object:** A description of the object structure and its contents.
+- 4.80 root rt-component:** A non-plugged rt-component. A root rt-component addresses either a root rt-composite or a root rt-content.
+- 4.81 root rt-composite:** An rt-composite that is not plugged.
+- 4.82 root rt-content:** An rt-content that is not plugged. A root rt-content addresses either a root rt-non-mux or a root rt-mux.
+- 4.83 root rt-mux:** An rt-mux that is not plugged.
+- 4.84 root rt-non-mux:** An rt-non-mux that is not plugged.
+
+- 4.85     rt-component:** An rt-component addresses either a root rt-component or an rt-component socket.
+- 4.86     rt-component socket:** A socket in which an rt-component is plugged. An rt-component socket addresses either an rt-composite socket or an rt-content socket.
+- 4.87     rt-composite:** A run-time object created from a model composite object. The elements of an rt-composite are called sockets. An rt-composite addresses either a root rt-composite or an rt-composite socket.
+- 4.88     rt-composite socket:** An rt-composite that is plugged.
+- 4.89     rt-content:** A run-time object created from a model content object. An rt-content addresses either a root rt-content or an rt-content socket.
+- 4.90     rt-content socket:** An rt-content that is plugged. An rt-content socket addresses either an rt-non-mux socket or an rt-mux socket.
+- 4.91     rt-mux:** A run-time content created from a model multiplexed content object. An rt-mux addresses either a root rt-mux or an rt-mux socket.
+- 4.92     rt-mux socket:** An rt-mux that is plugged.
+- 4.93     rt-non-mux:** A run-time content created from a pure model content object, i.e. not from a multiplexed content object. An rt-non-mux addresses either a root rt-non-mux or an rt-non-mux socket.
+- 4.94     rt-non-mux socket:** An rt-non-mux that is plugged.
+- 4.95     rt-object, run-time object:** A run-time object created from a model object. For the purpose of reusing model objects in different contexts, a clear separation has been made between the MHEG model interchange object that contains the original definition and the rt-object corresponding to a specific usage of the model. The use of an rt-object does not affect the model object. This allows the reuse of the same model object in different rt-objects. A model object is considered a template. Any number of rt-objects may be created based on instructions given by the author, i.e. action New. This Recommendation defines an initial behaviour of each rt-object and actions that will modify and retrieve this behaviour. The internal representation of the rt-objects is not defined by the standard. Each MHEG engine may have its own internal representation technique. However, this Recommendation defines the identification techniques to reference an rt-object in order to modify or to retrieve its behaviour.
+- An rt-object addresses either an rt-script or an rt-component.
+- 4.96     rt-script:** A run-time object created from a model script object.
+- 4.97     run-time process:** An ability to process an interpreted code in an MHEG engine.
+- 4.98     script object:** An instance of an MHEG class defining a structure to interchange script data in a specified encoded form.
+- 4.99     scriptware; script software:** A process or set of processes that handle scripts.
+- 4.100    sequencing:** The ordering of the preparation of objects, as specified by the object designer, that makes best use of the available resources to produce an acceptable presentation.
+- 4.101    sibling relationship:** Relationship between sockets of a given generation within an rt-composite.
+
+**4.102 socket:** The elements of an rt-composite in that rt-components are plugged are called sockets. Therefore, a socket is equivalent to an rt-component that is plugged. Once an rt-component is plugged, it can be referenced only via its socket identification. Different types of sockets are defined depending on the rt-component plugged into the socket: empty socket, rt-content socket (an rt-non-mux socket or an rt-mux socket) and rt-composite socket.
+
+**4.103 status:** A value representing the current state of an object within the MHEG engine.
+
+NOTE – The processes composing the MHEG engine are outside the scope of this Recommendation. However, this Recommendation requires a mechanism for evaluating the different statuses of objects within the MHEG engine.
+
+**4.104 storage media:** The means used to store information (e.g. electronic memory, floppy disk, hard disk, optical disk, magnetic tape).
+
+**4.105 structure of an object; MHEG object structure:** A description of how the information in an object is organised.
+
+**4.106 synchronisation:** The presentation of rt-components in time and space according to constraints and relationship defined between those objects. The constraints and relationship may be defined explicitly, within link objects, composite objects, script objects or, implicitly, through the nature of the application.
+
+**4.107 temporal position:** A specified position on the temporal axis of an rt-component or a channel.
+
+**4.108 timestamp:** An identified marker for a temporal position. This marker may be used to trigger links.
+
+**4.109 transition duration:** An optional parameter that may be provided for certain elementary actions, e.g. Set Current Volume (target set, audible volume, transition duration). A transition duration is expressed in GTU. When a transition duration is specified, the corresponding elementary action is to be processed during the specified duration, e.g. the audible volume value changes gradually from its previous value to the specified value within the specified transition duration.
+
+**4.110 transmission media:** The means used to transmit information (e.g. twisted pair, coaxial cables, optical fibres, radio links).
+
+**4.111 trigger condition:** A part of a link condition describing a change of an attribute or status value. If the described change happened, the trigger condition is said to be satisfied.
+
+**4.112 user effect:** The effect caused by the processing of an elementary action that is perceived by a user.
+
+**4.113 using application:** An application that makes use of MHEG objects, including ITU-T Recommendations or ISO Standards.
+
+## 5 Symbols and abbreviations
+
+The following symbols and abbreviations are used in this Recommendation:
+
+|       |                                                                              |
+|-------|------------------------------------------------------------------------------|
+| AP    | Attachment Point                                                             |
+| ASN.1 | Notation and encoding rules as provided by Recommendations X.680 and X.681.  |
+| AVR   | Audible Volume Range                                                         |
+| BER   | Basic ASN.1 Encoding Rules as provided by ITU-T Rec. X.690   ISO/IEC 8825-1. |
+| CC    | Current Condition within a link condition                                    |
+| CGSU  | Channel original Generic Spatial Unit                                        |
+| CPS   | Channel Presentation Space                                                   |
+| CRPS  | Channel Relative Presentation Space                                          |
+| CTP   | Current Temporal Position                                                    |
+| CV    | Current audible Volume                                                       |
+
+|      |                                                                                                                                                                                                                                                                                                                                                                                                         |
+|------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| EA   | Elementary Action                                                                                                                                                                                                                                                                                                                                                                                       |
+| GF   | Generic Factor                                                                                                                                                                                                                                                                                                                                                                                          |
+| GSF  | Generic Spatial Factor                                                                                                                                                                                                                                                                                                                                                                                  |
+| GSU  | Generic Spatial Unit                                                                                                                                                                                                                                                                                                                                                                                    |
+| GTF  | Generic Temporal Factor                                                                                                                                                                                                                                                                                                                                                                                 |
+| GTU  | Generic Temporal Unit                                                                                                                                                                                                                                                                                                                                                                                   |
+| GU   | Generic Unit                                                                                                                                                                                                                                                                                                                                                                                            |
+| GUI  | Graphical User Interface                                                                                                                                                                                                                                                                                                                                                                                |
+| GVF  | Generic audible Volume Factor                                                                                                                                                                                                                                                                                                                                                                           |
+| JBIG | Bi-Level Image Encoding Standard provided by Recommendation T.82: Information technology – Digital Compression and Coding of Bi-level Images.                                                                                                                                                                                                                                                           |
+| JPEG | Photographic Image Encoding Standard provided by Recommendations T.81, T.83, T.84: Information technology – Digital Compression and Coding of Continuous-tone Still Images.                                                                                                                                                                                                                             |
+| LC   | Link Condition within a link object                                                                                                                                                                                                                                                                                                                                                                     |
+| LE   | Link Effect within a link object                                                                                                                                                                                                                                                                                                                                                                        |
+| MH   | Multimedia Hypermedia                                                                                                                                                                                                                                                                                                                                                                                   |
+| MHEG | Adjective meaning of multimedia and hypermedia information coding scheme provided by ISO/IEC JTC1/SC29/WG12 – Multimedia Hypermedia Experts Group.<br><br>NOTE – If MHEG is used without any combination of nouns, it means the working group in JTC1. Otherwise, it should be used as an adjective followed by a noun to be unambiguous in its meaning, e.g. MHEG objects, MHEG actions, MHEG classes. |
+| MPEG | Audiovisual encoding standards provided by Recommendation H.262: Information technology – Coding of Moving Pictures and Associated Audio for Digital Storage Media up to about 1.5 Mbit/s and Recommendation H.222: Information technology – Generic Coding of Moving Pictures And Associated Audio.                                                                                                    |
+| mux  | Multiplexed                                                                                                                                                                                                                                                                                                                                                                                             |
+| OAP  | Original visible size Attachment Point                                                                                                                                                                                                                                                                                                                                                                  |
+| OD   | Original Duration                                                                                                                                                                                                                                                                                                                                                                                       |
+| OGSU | Original Generic Spatial Unit                                                                                                                                                                                                                                                                                                                                                                           |
+| OGTU | Original Generic Temporal Unit                                                                                                                                                                                                                                                                                                                                                                          |
+| OGU  | Original Generic Unit                                                                                                                                                                                                                                                                                                                                                                                   |
+| OGVU | Original Generic audible Volume Unit                                                                                                                                                                                                                                                                                                                                                                    |
+| OPS  | Original Presentation Space                                                                                                                                                                                                                                                                                                                                                                             |
+| OS   | Original Size                                                                                                                                                                                                                                                                                                                                                                                           |
+| OV   | Original audible Volume                                                                                                                                                                                                                                                                                                                                                                                 |
+| OVD  | Original Visible Duration                                                                                                                                                                                                                                                                                                                                                                               |
+| OVS  | Original Visible Size                                                                                                                                                                                                                                                                                                                                                                                   |
+| PAP  | Projected original visible size Attachment Point                                                                                                                                                                                                                                                                                                                                                        |
+| PC   | Previous Condition within a link condition                                                                                                                                                                                                                                                                                                                                                              |
+| PCV  | Projected Current audible Volume                                                                                                                                                                                                                                                                                                                                                                        |
+| POD  | Projected Original Duration                                                                                                                                                                                                                                                                                                                                                                             |
+| POS  | Projected Original Size                                                                                                                                                                                                                                                                                                                                                                                 |
+| PRPS | Parent Relative Presentation Space                                                                                                                                                                                                                                                                                                                                                                      |
+
+|      |                                           |
+|------|-------------------------------------------|
+| PS   | Presentation Space                        |
+| PTU  | Physical Temporal Unit                    |
+| PU   | Physical Unit                             |
+| PVD  | Projected Visible Duration                |
+| PVS  | Projected Visible Size                    |
+| PVU  | Physical audible Volume Unit              |
+| RGSU | Relative Generic Spatial Unit             |
+| RGTU | Relative Generic Temporal Unit            |
+| RGU  | Relative Generic Unit                     |
+| RGVU | Relative Generic audible Volume Unit      |
+| RPS  | Relative Presentation Space               |
+| rt   | Run-Time                                  |
+| TC   | Trigger Condition within a link condition |
+| TD   | Transition Duration                       |
+| VD   | Visible Duration                          |
+
+## SECTION 1 – OVERVIEW
+
+### 6 T.171 principal features
+
+#### 6.1 Interchanging multimedia objects
+
+A multimedia object has little use on its own. It becomes useful in a multimedia application. A multimedia application needs some method by which multimedia objects can be described and represented in an application-independent way for interchanging them with other applications. In this context, this Recommendation provides the means of multimedia object interchange in the form of MHEG objects.
+
+#### 6.2 The object-oriented approach
+
+This Recommendation uses some object-oriented techniques like object classes and inheritance. This subclause describes the specific usage of object-oriented concepts within this Recommendation.
+
+##### 6.2.1 Object classes
+
+This Recommendation uses the term of “object class” solely for denoting structures of interchangeable multimedia/hypermedia objects. As such, MHEG classes specify the structure of MHEG objects rather than their interfaces. Especially, MHEG does not specify methods as part of classes (or their interfaces, respectively).
+
+The purpose of this approach is that MHEG objects be considered as information entities that are interpreted by an appropriate process, i.e. the MHEG engine, to realise behaviour.
+
+##### 6.2.2 Subclasses and inheritance
+
+This Recommendation uses the concept of deriving new classes from existing ones. Subclasses inherit all structure from their superclass (i.e. the class they are subclass of) and add new attributes with the aim to add new behaviours or replace inherited ones with the aim to adapt existing behaviours.
+
+### 6.2.3 Polymorphism
+
+The MHEG engine can perform certain actions on MHEG objects, e.g. prepare them for further usage or set some attribute values. Polymorphism applies to these actions. Polymorphism means that if the application of an action is valid for objects of a certain class, it is also valid for objects of all their subclasses, but the effect may be different for different classes. Polymorphism is a way to represent that the parent has a generic (common) behaviour and that each of the children could have a specific behaviour.
+
+For example, the implementation of a Run action targeted to a run-time content object representing a text is different from the implementation of that targeted to a run-time multiplexed content object representing MPEG bitstream. The generic common behaviour is the presentation (run) of the instance, and the specific part for the video is to present video.
+
+### 6.2.4 Objects and object life cycles
+
+Three forms of MHEG objects are distinguished within this Recommendation as shown in Figure 2:
+
+- 1) The interchangeable multimedia/hypermedia-information, encoded according to Annex A.
+- 2) The representation within the MHEG engine, usable for internal purposes (e.g. MHEG object stored in its native internal representation, computation of link conditions).
+- 3) Copies of 2), usable for presentation by the user. These are referred to as rt-objects.
+
+![Diagram illustrating the different forms of MHEG objects and their life cycle.](fb18a83d10ebdad8e3e5ea2e86b36136_img.jpg)
+
+The diagram is divided into two main sections: 'Scope of this Recommendation' and 'Presentation environment (MHEG engine)'. In the 'Scope of this Recommendation' section, an 'MHEG class' (represented by a circle) leads to 'Form 1 object' (represented by a stack of rectangles) via an arrow labeled 'Creation (instantiation)'. Below 'Form 1 object' is the text 'for interchange'. In the 'Presentation environment (MHEG engine)' section, 'Form 1 object' leads to 'Form 2 object' (represented by a stack of rectangles) via an arrow labeled 'Conversion to internal format'. Below 'Form 2 object' is the text 'for internal use'. 'Form 2 object' then leads to 'Form 3 object' (represented by a stack of rectangles) via an arrow labeled 'Preparing for presentation'. Below 'Form 3 object' is the text 'for presentation'. The diagram is identified by the code 'T0825510-96/d004' at the bottom right.
+
+Diagram illustrating the different forms of MHEG objects and their life cycle.
+
+Figure 2/T.171 – The different forms of MHEG objects
+
+Basically, the life cycle of form 1) objects is out of the scope of this Recommendation. Once they are created by some encoding mechanism as instances of concrete MHEG classes, they remain in existence, e.g. in a repository until destroyed by means not covered by this Recommendation. However, if an MHEG object of form 1), which may be a copy of some original object, is received by an MHEG engine, it is converted into form 2). The form 2) remains in existence until a Destroy action is applied to it. The form 3) comes into existence whenever a New action is applied to an appropriate form 2) object (i.e. a model object), resulting in a copy of this object but of form 3), which can be presented and may have its attribute values changed. Form 3) objects are removed from existence by use of a Delete action.
+
+It should be noted that forms 2) and 3) objects live within a presentation environment, i.e. the MHEG engine. This implies that they are assumed to be extinct whenever the presentation environment vanishes.
+
+## 6.3 Technical features
+
+In this subclause, some technical features achieved by this Recommendation are described.
+
+Because of the generic nature of this Recommendation, nothing prevents an user for combining the following facilities. However, an using application may impose rules to implement a more appropriate architecture.
+
+### 6.3.1 Object composition for interchange and presentation
+
+Two techniques for object composition are used and provided by this Recommendation. One is the container concept provided by the container class which is used as an information packing tool to convey multimedia and hypermedia information. The other is the presentation composition provided by the composite class which is used as an information presentation tool under the control of a multimedia and hypermedia scenario.
+
+The container class enables the combination of a set of multimedia and hypermedia objects to be interchanged between storage systems and presentation systems. The container class groups a set of objects to be interchanged as a whole, taking into account the needs of minimal resource systems. By using this mechanism, the efficient exchange of multimedia data between heterogeneous systems can be achieved on their needs, for example. When objects in a container are to be used in a presentation, a certain number of preparation action is required before the object can participate in this presentation.
+
+Figure 3 illustrates the use of this Recommendation as an interchange unit and as an identifier of multimedia information encoded according to other International Standards.
+
+The composite class enables the combination of a set of multimedia and hypermedia objects to be presented. It provides a common presentation facility for those objects included in it, and describes presentations varying from the simplest monomedia object to complex multimedia and hypermedia interactions.
+
+![Diagram illustrating the interchange and identification of multimedia information. A large container box holds four smaller boxes, each representing a multimedia object. The objects are labeled JPEG, JBIG, MPEG, and TEXT. Each object box contains a small square icon and a label. The container box has a handle on top.](d8698aacaeead6dfed9a1e448670a2e4_img.jpg)
+
+The diagram shows a large rectangular container box with a handle on top. Inside the container, there are four smaller boxes arranged in a 2x2 grid. Each of these smaller boxes also has a handle on top and contains a small square icon and a label. The labels are 'JPEG', 'JBIG', 'MPEG', and 'TEXT' from top-left to bottom-right. The icons are small squares, some of which are shaded. The entire container box is labeled 'T0825520-96/d005' at the bottom right.
+
+Diagram illustrating the interchange and identification of multimedia information. A large container box holds four smaller boxes, each representing a multimedia object. The objects are labeled JPEG, JBIG, MPEG, and TEXT. Each object box contains a small square icon and a label. The container box has a handle on top.
+
+Figure 3/T.171 – Interchange and identification of multimedia information
+
+### 6.3.2 Run-time objects
+
+For the purpose of reusing objects in different contexts, a clear separation is to be made between an interchange object, called **model object**, and a run-time object, called **rt-object**. The model object corresponds to original reusable information. It is an instance of an MHEG object class containing script data, monomedia, multimedia and/or hypermedia information. An rt-object represents one specific use of the model object. It is used for presentation. Any number of rt-objects may be created from a single model object.
+
+The internal representation of rt-objects is not defined by this Recommendation. Each MHEG engine may have its own internal representation technique. The activation and attribute modification of an rt-object do not affect the original model object. This allows the reuse of the same original model object in different contexts.
+
+NOTE – For example, in a hockey game, two content objects are needed: B (blue team) and R (red team). Content B contains the original drawings of a blue team hockey player and content R contains the original drawings of a red team hockey player. Several rt-contents can be made from these model content objects as follows:
+
+- Rt-contents 1 to 10, corresponding to the 10 hockey players from the blue team, are created from the content B.
+- Rt-contents 11 to 20, corresponding to the 10 hockey players from the red team, are created from the content R.
+
+All the information related to the presentation is described for each rt-content. For example, rt-contents 1 to 6 (blue team) and 11 to 16 (red team) have different positions on the rink. Rt-contents 7 to 10 have positions on the blue team bench, and rt-contents 17 to 20 have positions on the red team bench.
+
+The presented size of each rt-content may be different. And the presentation attributes may be evaluated on each rt-content, in order to know at a precise moment if a player (i.e. an rt-content) is in a hospital (not running) or on the ice (running).
+
+### 6.3.3 Individual behaviour common to all rt-objects created from a given model object
+
+This Recommendation offers a mechanism to describe individual behaviour common to all the rt-objects, that may be created from a given model object. The advantages of this facility are:
+
+- the behaviour is described only once and applies to all the rt-objects;
+- the object designer is able to describe a common individual behaviour without knowing the number of rt-objects to be created from the given model object;
+- once prepared, the link applies to all rt-objects already created as well as future made rt-objects.
+
+This facility is provided by the “?” tail reference techniques (see 11.3).
+
+### 6.3.4 Synchronisation
+
+Essentially, multimedia object synchronisation mechanisms are categorised into four classes as follows:
+
+- Elementary synchronisation: Two objects are synchronised either:
+  - both with regard to the same reference origin time (parallel mode); or
+  - one with regard to the other (sequential mode).
+- Chained synchronisation: A set of objects is to be presented one after another in the form of a chain.
+- Cyclic synchronisation: One or more objects is to be repetitively presented.
+- Conditional synchronisation: The presentation of an object is linked to the satisfaction of a condition.
+
+In this Recommendation, these four classes of synchronisation are provided in a single describing manner, which is the conditional synchronisation.
+
+Multimedia object synchronisation levels are categorised into the following four levels:
+
+- 1) Script: The script may contain complex synchronisation taking into account user replies, calculated values, and the state of system resources, for example:
+  - Script synchronisation is not defined by this Recommendation.
+- 2) Conditional: The current state of the presented object may trigger a reflex action to another object, e.g. “when the audio has finished, ask the question”.
+
+- 3) Spatio-temporal: Position in time and space of one object may be relative to another, e.g. “show the product name 2 cm above the image, 2 s after the presentation of the image”.
+- 4) Intermedia: Close synchronisation within a multiplexed content object, e.g. “lip sync” for movies.
+
+Intermedia synchronisation is provided by other standards such as MPEG.
+
+### **6.3.5 Links**
+
+MHEG links are associative, dynamic, and event driven. There are many types of links; however, they may be categorised into two types as follows:
+
+- 1) Object Synchronisation Link: Describes the synchronisation among multimedia objects.
+- 2) Hyperlink: Describes the object relationship in the sense of context. Any related hypermedia objects are linked by this mechanism.
+
+This Recommendation provides both types of links by a single mechanism of object linking within link object.
+
+The set of MHEG links is highly dynamic. Links may be added and removed at any time and may be conditional depending on user activity and previous performance in order to adapt the behaviour during the life of the presentations.
+
+The MHEG links are driven by a change of MHEG entity behaviour, e.g. an object becomes ready, or the volume of an rt-content increases. Each link describes a change that may trigger it and the effect that it will have.
+
+MHEG links are fully resolved and require no further processing other than their direct execution.
+
+### **6.3.6 Input**
+
+In order to support interactive multimedia/hypermedia systems, it is essential to provide some mechanism user input. In this Recommendation, the list of possible interactions offered to the user is described using composite objects. Input is considered a behaviour and is based on selection and modification behaviours of rt-components.
+
+This Recommendation provides facilities to describe the results of the user interaction but does not provide the interaction facilities. Such interaction may be achieved in a variety of ways, e.g. GUIs (Graphical User Interface) and keyboards. This Recommendation does not define the look-and-feel of multimedia interactive presentations, nor does it propose to change or add concepts to those that exist in typical GUIs. As this Recommendation is generic and independent of platform and implementation, it describes interaction at a virtual level.
+
+### **6.3.7 Event handling**
+
+MHEG objects are able to interact with events through event handling mechanisms. An event is generated by either the outer system or the MHEG engine itself.
+
+When an event is generated, the MHEG engine sets the corresponding catalogued event identification to the event attribute and, if needed, associated information to the event data attribute of the rt-object or channel that should receive this event. For example, a mouse click event on a button generated by the GUI can be sent to an rt-object as event number 10 with associated x-y position information.
+
+Event handling mechanisms may be used for general purpose synchronisation and interaction mechanism.
+
+### **6.3.8 Anchor**
+
+In order to support hypertext and hypermedia, this Recommendation provides an anchor mechanism. An anchor is a content object that holds anchor information rather than media data. This anchor information defines an area within another content object data. This area is to be presented on the other data by the GUI with the rendering specified within the objects or using a specified style. As the anchor is interchanged within a content object, rt-content can be created from the content object and all the behaviours of rt-content apply, e.g. running, selection.
+
+### 6.3.9 Real time
+
+This Recommendation has no control over and makes no assumptions about the quality or capability of the underlying networks through which using applications may interchange MHEG objects. There may already exist some LANs (Local Area Network) that could meet all the capacity requirements for real-time interchange of applications, and future standards may specify some WANs (Wide Area Network) with appropriate capabilities. This Recommendation deals with these uncertain circumstances in two ways:
+
+- This Recommendation allows the author to define a set of specifications that would necessarily have to be satisfied to ensure real-time applications regardless of the interchange media capabilities. In addition, the MHEG object specification provides mechanisms that ease real-time interchange independent of the underlying network capabilities.
+- An MHEG descriptor object provides the following:
+  - a description of objects to be supported by the system;
+  - a description of media encoding;
+  - a system-readable material and a read-me mechanism by which communicating applications can negotiate an optimum interchange session. In this regard, the descriptor object provides a placeholder for references to other standards that are needed for allocation of network resources among complementary and competing applications;
+  - offset information of objects.
+
+Requirements for real-time capability are satisfied as follows:
+
+- Object placement optimisation and the progressive access of objects are the responsibility of the using application. Object offset information may be used to achieve quick retrieval of a certain object encoding in another object.
+- The partial object retrieval, object sequencing, and separate retrieval of object description and object content are features of the Prepare and Destroy actions usage and process.
+- The resource requirements are supported by the MHEG descriptor object.
+- The object interleaving is supported by the MHEG multiplexed content object. This Recommendation does not provide interleaving facilities but supports the indication of interleaved objects.
+- Aggregate retrieval is supported by the MHEG container object.
+
+### 6.3.10 Object management
+
+#### 6.3.10.1 Object identification
+
+General object identification is needed for copyright, owner identification, and unique identification. This Recommendation provides a description mechanism for this information in an MHEG object. And among this description mechanism, the unique identification mechanism is a key for the processing of MHEG objects inside the MHEG engine.
+
+An internal identifier and an external identifier are provided in order to support unique identification. These identifiers are used to reference objects. The internal identifier is an encoded identifier within an MHEG object and consists of an identifier or an index. The external identifier acts as a connector between MHEG object domain and entities outside of the MHEG domain and consists of a public identifier and a system identifier.
+
+This Recommendation also provides symbolic identification using aliases. This identification may replace any other identifications.
+
+#### 6.3.10.2 Object reference
+
+Reference to local and remote objects, as an alternative to physical inclusion is needed. This Recommendation provides a generic reference mechanism to any entity defined by this Recommendation.
+
+### 6.3.10.3 Object content
+
+A uniform interface to content data is needed. This Recommendation provides this mechanism in the description of content class.
+
+### 6.3.10.4 Uniform objects
+
+An uniform view of objects by using applications is needed. This Recommendation provides this uniform view by means of MHEG object hierarchy.
+
+### 6.3.11 Minimal resources
+
+Extraction of relevant component data on a timely basis for minimal resource systems is considered in this Recommendation. There are several aspects:
+
+- 1) **Inter-object interleaving:** This is outside the scope of this Recommendation because it is a system issue. MHEG does not provide interleaving facilities but supports the indication of interleaved objects by the use of the multiplexed content object.
+- 2) **Sequencing:** This is defined in this Recommendation by a specific use of the Prepare action.
+- 3) **Degradation and negotiation of required resources:** The descriptor objects provide complementary information about a set of interchanged objects useful for the degradation of some presentation and the negotiation of minimal resources requirements.
+
+### 6.3.12 Presentation and structuring dynamism
+
+Once a run-time composite, called an rt-composite, is made from an original composite object, the rt-components attached to the sockets may be removed or replaced using the plub action. This allows dynamism in the presentation if the plugged rt-contents are changed and a dynamism in the structure of the rt-composite, if the plugged rt-composites are changed.
+
+### 6.3.13 Macro action and link
+
+The macro facility provides a general technique for producing efficient coding of frequently used action objects in which only a few values change from one link to another. The same applies on frequent link conditions in which only a few values change from one link to another. This allows the sharing and reuse of complex behaviours. An author may create a catalogue of predefined action object and link object templates.
+
+### 6.3.14 Static and dynamic assignment of generic value
+
+A generic value may be specified as a constant or as an evaluated result of a get action. Generic values are essential values processed inside an MHEG engine. Generic values can be stored and retrieved from content object data. An evaluated value may be stored after its evaluation, i.e. a constant is stored, e.g. content data = "hello". An evaluated value can also be stored without any processing, i.e. the get action is stored, e.g. content data = Get Preparation Status (target), in which case, the evaluation is performed dynamically each time this generic value is retrieved.
+
+## 7 MHEG Engine Assumptions
+
+### 7.1 Handling and Interchange of objects
+
+This Recommendation does not define the way in which an MHEG engine handles the objects, neither the interchanged MHEG objects nor the rt-objects. But it makes some assumptions about the features of MHEG engines in order to be able to define further actions on the objects.
+
+- 1) This Recommendation assumes that the MHEG object, once it has been interchanged, is used by an using application and handled by the MHEG engine.
+
+- 2) This Recommendation makes no assumptions on the internal structure or organisation of the MHEG engine, with these exceptions:
+- a) The MHEG engine is expected to correctly interpret MHEG effect of MHEG action.
+  - b) The MHEG engine is able to evaluate status and attribute values of MHEG entities which are under its control. The changes that occur on the status or attribute value may be used to express conditions in links.
+  - c) When an MHEG engine uses an entry of a catalogue, it is expected that this engine correctly interpret this entry as described in the catalogue.
+  - d) The MHEG engine is able to work with a user interface support system, when it exists, and to obtain from this user interface system the results of the interaction with the user. These results are formalised by the MHEG engine in order to modify the corresponding interaction statuses. For example, the user interface support system indicate to the MHEG engine that a specific element of a given object has been selected, and thus the MHEG engine will be able to modify the corresponding interaction and selection status. This change of status may fire a link and carry on an action as specified in a given MHEG object.
+
+In order to facilitate understanding of the role played by this Recommendation, this clause shows in more detail the role of the objects in the interchange between two systems, as shown in Figure 4.
+
+![Diagram illustrating the interchange of MHEG objects between two systems, A and B. System A contains an MHEG engine with an MHEG encoder and internal format. System B contains an MHEG engine with an MHEG decoder and internal format. An MHEG object is shown being transmitted from the encoder in A to the decoder in B through an interchange point.](834fb96b114b8fdc001625e1ae28e8b1_img.jpg)
+
+The diagram shows two systems, A and B, separated by a vertical dotted line labeled 'Interchange'. System A is on the left and contains a rounded rectangle labeled 'MHEG engine'. Inside this engine is a box labeled 'MHEG encoder' and a stack of three boxes labeled 'Internal format'. System B is on the right and contains a rounded rectangle labeled 'MHEG engine'. Inside this engine is a box labeled 'MHEG decoder' and a stack of three boxes labeled 'Internal format'. A diamond-shaped box labeled 'MHEG object' is positioned in the center, between the two systems. An arrow points from the 'MHEG encoder' in system A to the 'MHEG object' diamond, and another arrow points from the 'MHEG object' diamond to the 'MHEG decoder' in system B.
+
+T0825530-96/d006
+
+Diagram illustrating the interchange of MHEG objects between two systems, A and B. System A contains an MHEG engine with an MHEG encoder and internal format. System B contains an MHEG engine with an MHEG decoder and internal format. An MHEG object is shown being transmitted from the encoder in A to the decoder in B through an interchange point.
+
+**Figure 4/T.171 – Interchange of MHEG objects**
+
+The MHEG object is defined only at the interchange point between the using applications A and B. When system A wishes to send an MHEG object to B, it calls an MHEG **encoder**, which converts the internal format used by A to the format defined by this Recommendation.
+
+When B receives an MHEG object, the object is decoded by an MHEG **decoder**. The values within the object are passed by the decoder, which may convert them to the internal format used by B.
+
+#### NOTES
+
+1 – The internal formats in the using applications A and B may be the same as the MHEG format, but nothing in this Recommendation requires this.
+
+2 – If the exchange between A and B is in both directions, the two systems may have both encoder and decoder.
+
+## 7.2 The MHEG application interface
+
+The MHEG engine is assumed to provide an interface to the using application. This interface will provide facilities for control of the MHEG engine and is the only access point for the application to MHEG objects within the MHEG engine. This Recommendation does not define the scope or the form of the MHEG engine interface, nor does it define the structure of data passing across this interface.
+
+### 7.3 Exception handling
+
+This Recommendation describes the recommended reactions of an MHEG engine on abnormal or exceptional situations possibly encountered during execution time. These reactions are neither considered to be minimal nor complete, which means that an MHEG engine can do more (e.g. write to a log file or inform the application) or even less (e.g. stop processing). The described behaviour is recommended but not required for conformance.
+
+NOTE – Specific reactions on error conditions are given with each specific situation throughout the section behaviour of ISO 13522-1.
+
+## 8 Methodology
+
+This clause describes the methodology used to specify this Recommendation and is provided as a help to the user in understanding this Recommendation. It does not imply that a conforming system or product uses this methodology for either analysis or implementation. This is the case for the general object orientation that is chosen for the design of this Recommendation.
+
+In the context of this Recommendation, an object class denotes a structure of interchangeable multimedia/hypermedia information, from which MHEG objects can be instantiated. This Recommendation restricts the usage of object-oriented concepts to specialisation, inheritance, and polymorphism.
+
+### 8.1 Modularity
+
+In order to allow an using application to make use of only some of the objects provided for by this Recommendation, the representation itself is in the form of a set of modules organised as follows:
+
+- one module per interchanged object class;
+- one module containing all the useful definitions and the abstract classes;
+- one module containing all the elementary actions.
+
+NOTES
+
+1 – In the way mentioned above, it is expected that an application process will incur the minimum overhead due to the objects not used.
+
+2 – It is intended that any future extension to the representations provided by this Recommendation (see Figure 5) shall also be isomorphic with respect to the modularity of the base representation.
+
+### 8.2 Methodology of representation of MHEG objects
+
+This Recommendation provides a description of an MHEG object, a precise definition of the structure of the object, and a base-coded representation for the object. The base coded representation defined in this Recommendation uses ASN.1.
+
+Alternative structure representations may be provided. They are intended to be isomorphic and equivalent for the purposes of this Recommendation (see Figure 5).
+
+NOTE – It is intended that the base transfer syntax provided by this Recommendation and alternative syntaxes provided by other parts of this Recommendation shall be consistent and that it is possible to convert an MHEG object instance from one to another. However, this process is not defined by this Recommendation.
+
+The representation of an MHEG object is specified through four levels:
+
+- description of representation;
+- object-oriented definition (structure and semantics);
+- notation for the structure of the representation; and
+- the coded representation defined by applying encoding rules to the representation (see Figure 5).
+
+The description of the representation provided by this Recommendation includes the structure of the representation and sufficient semantics to allow a concrete understanding of the meaning of an MHEG object. This Recommendation does not provide semantics for a conforming application process making use of this object.
+
+![Diagram showing the levels of methodology used by this Recommendation, organized into four main sections: A, B, C, and D. Section A is 'Description of the representation'. Section B is 'Precise object oriented definition of the representation'. Section C is 'Isomorphic notations for the structure', containing 'Base' (Syntax using Rec. X.680) and 'Alternate' (Other notations that may be developed). Section D is 'Coded representations of the object', containing 'Base' (Basic encoding rules provided by Rec. X.690) and 'Other coded representations of objects that may be developed'.](e8e818455bb0d1a6153299a388b94868_img.jpg)
+
+The diagram illustrates the methodology levels, structured as follows:
+
+- A**: Description of the representation
+- B**: Precise object oriented definition of the representation
+- C**: Isomorphic notations for the structure
+  - Base**: Syntax using Rec. X.680. This is the BASE representation of the structure.
+  - Alternate**: Other notations that may be developed.
+- D**: Coded representations of the object
+  - Base**: Basic encoding rules provided by Rec. X.690. This is the BASE coded representation of the object.
+  - Other coded representations of objects that may be developed**.
+
+T0825540-96/d007
+
+Diagram showing the levels of methodology used by this Recommendation, organized into four main sections: A, B, C, and D. Section A is 'Description of the representation'. Section B is 'Precise object oriented definition of the representation'. Section C is 'Isomorphic notations for the structure', containing 'Base' (Syntax using Rec. X.680) and 'Alternate' (Other notations that may be developed). Section D is 'Coded representations of the object', containing 'Base' (Basic encoding rules provided by Rec. X.690) and 'Other coded representations of objects that may be developed'.
+
+**Figure 5/T.171 – Levels of the methodology used by this Recommendation**
+
+### **8.2.1 Level A – Description of representation**
+
+Level A provides the description of representation for each useful definition (see Section 2), each MHEG object (see Section 3), and each MHEG entity behaviour (see Sections 4, 5, 6, 7 and 8).
+
+### **8.2.2 Level B – Precise object-oriented definition**
+
+For each MHEG object class, the precise object-oriented definition is given by the following:
+
+- Class hierarchy: From which class it inherits and by which class(es) it is inherited.
+- Usage: Which class(es) it uses and by which class(es) it is used.
+- Structure: Attributes it contains, in addition to the inherited attributes.
+- Textual description: A short explanation of semantics and behaviour.
+
+The structure of classes is described using a context-free grammar in which the conventions described apply:
+
+- **X ::= I, J, K**      X is defined as a sequence of attributes I followed by J followed by K.
+- **X?**      None or one instance of X may occur.
+- **X+**      One or more instances of X may occur.
+- **X\***      Any number of instances of X may occur.
+- **(I | J | K)**      Exactly one of the set is to occur.
+- **(I, J, K)?**      The entire sequence may or may not occur.
+- **(I, J, K)+**      One or more instances of the entire sequence may occur.
+- **(I, J, K)\***      None or more instances of the entire sequence may occur.
+
+The structure and semantics of each representation attribute of the object (B in Figure 5) are described in latter subclauses with the structure shown in Figure 6.
+
+**Attribute name**
+
+- *semantics*
+- *type OR*
+- *structure of subattributes OR*
+- *choice between attributes OR*
+- *list of a subattribute*
+
+**Figure 6/T.171 – Structure of attribute subclause**
+
+**NOTE**
+
+- Each subattribute is described as an attribute.
+- Sequence of (A, B): means that subattribute A is followed by subattribute B.
+- List of (A, B): means that one or more instances of the entire sequence (A, B) may occur.
+
+### 8.2.3 Level C – Isomorphic notations for the structure of MHEG objects
+
+The standard provides a set of equivalent notations for the level B description of the structure of an MHEG object. The notations are equivalent in that they are isomorphic with respect to the MHEG object structure described in level B. However, one of the notations is the base notation, which is to be referred to in case of questions of conformity of a product or application process.
+
+The base notation for the representation of MHEG objects structure is provided by ASN.1. This is known as the base representation (C in Figure 5).
+
+NOTE – It is intended that any future additions to this Recommendation of notations for the representation of MHEG objects shall be isomorphic with MHEG object structure described in level B.
+
+### 8.2.3.1 ASN.1 techniques used in level C
+
+The ASN.1 notation for the structure of each MHEG class is typically as presented in Figure 7.
+
+```
+-- MHEG OBJECT CLASS MODULE
+
+© International Organisation for Standardisation, 1995. Permission to copy in any form
+  is granted for use with conforming MHEG engines and applications as defined in
+  Recommendation T.171, provided this notice is included in all copies.
+
+ISOMHEG-cl {joint-iso-itu-t(2) mheg (19), version (1), class-identifier (xx)},
+DEFINITIONS:=BEGIN
+EXPORTS MHEG-Object-Class;
+IMPORTS MH-Object-Class FROM ISOMHEG-MH {joint-iso-itu-t(2) mheg (19), version (1),
+MH-object (1000)};
+MHEG-Object-Class:= SEQUENCE
+{
+class-identification    OBJECT IDENTIFIER    {joint-iso-itu-t(2),           -- root
+                                              mheg (19),                 -- arc1
+                                              version (1),             -- arc2
+                                              class-identifier (xx)       -- arc3
+                                              },
+COMPONENTS OF MH-object,
+-- object class attributes
+}
+END
+```
+
+Figure 7/T.171 – Example of an ASN.1 module used for MHEG object representation
+
+The following ASN.1 techniques are used to represent the MHEG objects:
+
+- The technique of ASN.1 OBJECT IDENTIFIER is used. The object identifiers defined in this Recommendation are summarised in Annex A. The semantics of the object identifier is defined by reference to the following object identifier tree.
+- **root**: Origin of the standard. It shall be joint-iso-itu-t(2).
+- **arc1**: T.171 identification. It shall be 19. The identification of this Recommendation has been provided by the joint naming authority.
+- **arc2**: MHEG Standard version. It is set to 1 for this version of this Recommendation.
+- **arc3**: Class identifier. It is a number assigned to each MHEG class.
+- The ASN.1 modules are used in this Recommendation to represent the MHEG object classes and superclasses, and also to describe the useful definitions. Each module has an identification, which is expressed with an ASN.1 OBJECT IDENTIFIER. This identification is attached to the definition of the module and is not part of the definition of the MHEG class.
+
+This module OBJECT IDENTIFIER is not encoded within an MHEG object. It is used by another module within the IMPORT/EXPORT facilities in order to identify a module formally.
+
+- The ASN.1 IMPORT/EXPORT and the COMPONENTS OF facilities are used to represent the inheritance of attributes of MHEG object classes. Each superclass defines a SEQUENCE of attributes that are exported. This SEQUENCE is imported by the subclasses and COMPONENTS OF is used in order to inherit these attributes.
+- The ASN.1 IMPORT/EXPORT facilities are also used to represent the MHEG useful definition and the elementary actions. The useful definition module exports the definitions and the abstract classes. The elementary action module exports the elementary actions. Each MHEG object class module imports the corresponding definitions when needed.
+
+- Each MHEG object is represented as a sequence of attributes using the ASN.1 SEQUENCE facilities. Each attribute has an arbitrary structure.
+- The technique of an ASN.1 OBJECT IDENTIFIER is also used to uniquely identify each MHEG object class. This MHEG object class OBJECT IDENTIFIER is part of the definition of the class and will be encoded in each object instance.
+
+### 8.2.3.2 Copyright protection
+
+The formal ASN.1 definition is part of the text of this Recommendation and is protected by copyright. In order to facilitate conformance to MHEG, the formal ASN.1 definition in the body and Annex A . This Recommendation may be copied as specified in the following copyright notice:
+
+- © International Organisation for Standardisation, 1995. Permission to copy in any form is granted for use with conforming MHEG engines and applications as defined in Recommendation T.171, provided this notice is included in all copies.
+
+The permission to copy does not apply to any other material in this Recommendation.
+
+NOTE – An attribute is defined by this Recommendation for specifying the copyright notice attached to an MHEG object.
+
+### 8.2.4 Level D – Coded representation of MHEG objects
+
+This Recommendation provides a set of equivalent coded representations of MHEG objects. The coded representations are equivalent in that they are isomorphic with respect to the level B. However, one of the coded representations is the base-coded representation.
+
+The base coded representation is provided by ASN.1 BER.
+
+NOTE – It is intended that any future additions to this Recommendation of coded representations of MHEG objects shall be of notations isomorphic with the level B.
+
+## SECTION 2 – GENERIC UTILITY AND USEFUL DEFINITION MECHANISMS
+
+This Recommendation provides the following mechanisms:
+
+- Presentation mechanism (see clause 9);
+- Generic identification mechanism (see clause 10);
+- Generic reference mechanism (see clause 11);
+- Generic value (see clause 12);
+- Macro mechanism (see clause 13);
+- Hooks (see clause 14);
+- Extensibility (see clause 15).
+
+These generic mechanisms or definitions are used throughout the technical clauses of this Recommendation.
+
+Their coded representation is grouped in a separate ASN.1 module called “useful definitions module”.
+
+When an MHEG object requires a specific definition, its ASN.1 class representation imports the definition from the useful definition module.
+
+## 9 Presentation Mechanism
+
+This clause describes the general mechanism provided for a Presentation Space (PS) (see 9.1) used to present the rt-components to the user. It is composed of a generic coordinate system in time and space, and it also contains an Audible Volume Range (AVR) for audio expression.
+
+The values used to define the spatial, temporal and audible behaviour of rt-components are expressed in Generic Units (GU), e.g. position, size, duration and volume. This mechanism allows the interpretation of the units with respect to an associated PS.
+
+NOTE – This allows the cohabitation of data coming from different creation tools with different coordinate systems and audible volume ranges.
+
+A PS is associated with each rt-component. It is called Original PS (OPS) (see 9.2). A PS is also associated with each channel. It is called Channel PS (CPS) (see 9.3).
+
+In order to allow placement of children relative to their parent, each rt-component may be projected into a parent PS. For a child, its parent PS is called a Relative PS (RPS) (see 9.4). This parent can also be a child of another parent. So, there is a chain of mapping that ends at CPS: OPS to RPS to RPS...to CPS. At each projection a scaling factor, called Generic Factor (GF), is applied. This GF is defined as a ratio and specifies number of RGU Relative GU (RGU) to be mapped to one Original GU (OGU). Lastly, in order to be perceived by the user, each CPS is mapped by the MHEG engine onto a physical space (see 11.1).
+
+Figure 8 summarises the presentation techniques.
+
+![Figure 8/T.171 – Overview of presentation techniques. This diagram illustrates the mapping process from Component Objects to Physical presentation space. It shows four main stages: Component Object, Rt-Component OPS, Rt-Composite RPS, and Channel CPS, leading to the Physical presentation space. Arrows indicate the flow of data, with scaling factors (GTF, GSF, GVF) applied at each projection step. Successive projections are shown between RPS stages, and CPS mapping leads to the final physical space where PVD, PVS, and PCV are perceived by the user.](8d66c9c295023a1380f9986d3663bb1e_img.jpg)
+
+The diagram illustrates the presentation techniques through a series of mappings and projections:
+
+- Component Object** (containing OD, OS, OV) is mapped to **Rt-Component OPS** (containing OD, OS, OV and OVD, OVS, CV).
+- Rt-Component OPS** is projected to **Rt-Composite RPS** (containing POD, POS, PVD, PVS, PCV) using scaling factors  $\times$  GTF,  $\times$  GSF, and  $\times$  GVF.
+- Rt-Composite RPS** undergoes **Successive projections** to further RPS stages.
+- The final **Rt-Composite RPS** is mapped to **Channel CPS** (containing POD, POS, PVD, PVS, PCV) using scaling factors  $\times$  GTF,  $\times$  GSF, and  $\times$  GVF.
+- Channel CPS** undergoes **CPS mapping** to the **Physical presentation space**, where PVD, PVS, and PCV are perceived by the user in physical units.
+
+T0825550-96/d008
+
+Figure 8/T.171 – Overview of presentation techniques. This diagram illustrates the mapping process from Component Objects to Physical presentation space. It shows four main stages: Component Object, Rt-Component OPS, Rt-Composite RPS, and Channel CPS, leading to the Physical presentation space. Arrows indicate the flow of data, with scaling factors (GTF, GSF, GVF) applied at each projection step. Successive projections are shown between RPS stages, and CPS mapping leads to the final physical space where PVD, PVS, and PCV are perceived by the user.
+
+Figure 8/T.171 – Overview of presentation techniques
+
+## 9.1 Presentation Space (PS)
+
+Each PS is defined as follows:
+
+- a temporal axis T;
+- three spatial axes, X, Y and Z;
+- an AVR.
+
+### 9.1.1 Temporal axis
+
+Each PS has one temporal axis: T.
+
+The temporal axis is an interval  $[0, T\text{EndPoint}]$ , where the  $T\text{EndPoint}$  shall always be greater than or equal to 0. The  $T\text{EndPoint}$  can be specified as infinite. The point 0 is defined as the origin of the temporal axis.
+
+The number of addressable points within a temporal axis is  $(T\text{EndPoint} + 1)$ .
+
+The GU used along this axis is called Generic Temporal Unit (GTU).
+
+![Figure 9/T.171 – The T axis. A horizontal line representing the temporal axis T, starting at 0 and ending at an arrowhead. Tick marks are labeled 0, 1, 2, 3, 4, 5, 6, 7, ..., 1000, ..., Infinite.](3f09464f0a8ac9446981a53f9b78df2c_img.jpg)
+
+T0825560-96/d009
+
+Figure 9/T.171 – The T axis. A horizontal line representing the temporal axis T, starting at 0 and ending at an arrowhead. Tick marks are labeled 0, 1, 2, 3, 4, 5, 6, 7, ..., 1000, ..., Infinite.
+
+Figure 9/T.171 – The T axis
+
+The rt-component temporal behaviour uses temporal positions and temporal durations, which are expressed in GTU within the PS:
+
+- A temporal position:
+  - a point on the T axis;
+  - always defined within the interval [0, TEndPoint] on the corresponding T axis.
+- A duration:
+  - a distance between two temporal positions;
+  - defined as the length of an interval [StartPoint, EndPoint];
+  - always defined within the interval [0, TEndPoint] on the corresponding T axis;
+  - equal to (EndPoint – StartPoint). EndPoint shall be greater than or equal to StartPoint;
+  - the number of addressable points within a duration is (EndPoint – StartPoint + 1).
+
+Figure 10 illustrates temporal position and duration attributes.
+
+The temporal scaling factor is called Generic Temporal Factor (GTF). Its value  $n$  specifies that one Original GTU (OGTU) is to be mapped in  $n$  Relative GTU (RGTU).
+
+![Figure 10/T.171: A diagram of a temporal axis T. It shows a horizontal line with an arrow at the right end labeled 'T'. Two vertical tick marks are on the line. The first is labeled 'Position of StartPoint' and the second is labeled 'Position of EndPoint'. A horizontal bracket above the line between these two points is labeled 'Duration'. Below the diagram is the identifier 'T0825570-96/d010'.](7e61b2e2506cc7e5d6e16ce9c9df25bb_img.jpg)
+
+Figure 10/T.171: A diagram of a temporal axis T. It shows a horizontal line with an arrow at the right end labeled 'T'. Two vertical tick marks are on the line. The first is labeled 'Position of StartPoint' and the second is labeled 'Position of EndPoint'. A horizontal bracket above the line between these two points is labeled 'Duration'. Below the diagram is the identifier 'T0825570-96/d010'.
+
+**Figure 10/T.171 – Temporal position and duration**
+
+### 9.1.2 Spatial axes
+
+Each PS has three spatial axes — X, Y and Z — that shall be spanning a right-handed orthogonal coordinate system.
+
+Each spatial axis is to be perceived by the user in the direction defined by Figure 11: X from left to right, Y from bottom to top, and Z from display towards the user.
+
+NOTE – Extensions may be provided to allow views from alternative directions, e.g. through additional channel attributes.
+
+![Figure 11/T.171: A 3D diagram of a right-handed orthogonal coordinate system. The origin is labeled '0,0,0'. The X-axis points to the right, ending in an arrow and labeled 'X' with '+65535' at the tip. The Y-axis points upwards, ending in an arrow and labeled 'Y' with '+65535' at the tip. The Z-axis points diagonally down and to the left, ending in an arrow and labeled 'Z' with '+65535' at the tip. Below the diagram is the identifier 'T0825580-96/d011'.](042af54276c75e7b7b48a3af1f0a84e5_img.jpg)
+
+Figure 11/T.171: A 3D diagram of a right-handed orthogonal coordinate system. The origin is labeled '0,0,0'. The X-axis points to the right, ending in an arrow and labeled 'X' with '+65535' at the tip. The Y-axis points upwards, ending in an arrow and labeled 'Y' with '+65535' at the tip. The Z-axis points diagonally down and to the left, ending in an arrow and labeled 'Z' with '+65535' at the tip. Below the diagram is the identifier 'T0825580-96/d011'.
+
+**Figure 11/T.171 – The X, Y and Z axes of the presentation space**
+
+All instances of such PS shall be colinear relative to each other, meaning that all X axes are parallel, all Y axes are parallel and all Z axes are parallel.
+
+Each spatial axis is of finite length and is an interval  $[0, \text{SEndPoint}]$ , where  $\text{SEndPoint}$  shall always be greater than or equal to 0. A default value is also provided for  $\text{SEndPoint}$  and is equal to +65535. The point 0 is defined as the origin of each spatial axis. The point (0, 0, 0) is called the spatial origin.
+
+The number of addressable points within a spatial axis is  $(\text{SEndPoint} + 1)$ .
+
+The GU used along each spatial axis is called Generic Spatial Unit (GSU).
+
+The rt-component spatial behaviour uses spatial positions and sizes, which are expressed in GSU within the PS:
+
+- *A spatial position is:*
+  - a triple of points (x, y, z), one point on each spatial axis;
+  - always defined within the interval  $[0, \text{SEndPoint}]$  of the corresponding spatial axis.
+- *A size is:*
+  - a triple of distances (lx, ly, lz), one on each spatial axis, giving the length along each axis in the given order;
+  - each distance is defined as the length of an interval  $[\text{StartPoint}, \text{EndPoint}]$  on the corresponding axis;
+  - each distance shall be defined within the interval  $[0, \text{SEndPoint}]$  of the corresponding spatial axis;
+  - each distance is equal to  $(\text{EndPoint} - \text{StartPoint})$ .  $\text{EndPoint}$  shall be greater than or equal to  $\text{StartPoint}$ ;
+  - the number of addressable points within each distance is  $(\text{EndPoint} - \text{StartPoint} + 1)$ .
+
+Figure 12 illustrates spatial position and size attributes. In this figure, the Z axis is omitted for clarity.
+
+A spatial scaling factor is defined for each spatial axis, which is called Generic Spatial Factor (GSF). Its value n specifies that one Original GSU (OGSU) is to be mapped to n Relative GSU (RGSU).
+
+The GSF may be different for each spatial axis of a PS.
+
+![Figure 12/T.171 – Spatial position and size. A 2D coordinate system with X and Y axes. The origin is labeled (0,0). A gray rectangle represents a spatial object. The bottom-left corner of the rectangle is at the origin (0,0). The bottom-right corner is labeled 'X size'. The top-left corner is labeled 'Y size'. The top-right corner is labeled 'X size'. The Y-axis has two tick marks: 'Position of Y End_Point' at the top and 'Position of Y Start_Point' at the bottom. The X-axis has two tick marks: 'Position of X Start_Point' at the bottom and 'Position of X End_Point' at the top. The origin is labeled (0,0).](a2b0b8d868ec4ee43d7d3f0961a12b5e_img.jpg)
+
+T0825590-96/d012
+
+Figure 12/T.171 – Spatial position and size. A 2D coordinate system with X and Y axes. The origin is labeled (0,0). A gray rectangle represents a spatial object. The bottom-left corner of the rectangle is at the origin (0,0). The bottom-right corner is labeled 'X size'. The top-left corner is labeled 'Y size'. The top-right corner is labeled 'X size'. The Y-axis has two tick marks: 'Position of Y End\_Point' at the top and 'Position of Y Start\_Point' at the bottom. The X-axis has two tick marks: 'Position of X Start\_Point' at the bottom and 'Position of X End\_Point' at the top. The origin is labeled (0,0).
+
+**Figure 12/T.171 – Spatial position and size**
+
+### 9.1.3 Audible Volume Range (AVR)
+
+This Recommendation defines one unique AVR. Every audible expression is described within the AVR. The AVR is defined as the interval  $[0, +255]$ .
+
+The number of addressable points within the AVR is 256.
+
+The unit used along the axis is Generic audible Volume Unit (GVU).
+
+The rt-component audible behaviour uses audible volumes, which are expressed in GVU within the PS. An audible volume is always a point defined within the AVR value provided by this Recommendation.
+
+The audible volume scaling factor is called Generic audible Volume Factor (GVF). Its value  $n$  specifies that one Original GVU (OGVU) is to be mapped in  $n$  Relative GVU (RGVU).
+
+## 9.2 Original Presentation Space (OPS)
+
+### 9.2.1 Initialisation of OS and OD
+
+When an rt-component becomes available, a PS is associated with it, and it is called OPS. The temporal and spatial axes shall be initialised as follows:
+
+- a) The TEndPoint shall be initialised with the Original Duration (OD) value retrieved as follows:
+  - 1) if the OD is encoded within the component object, this value shall be used;
+  - 2) for an rt-content, if the OD is not encoded within the content object, the OD value may be retrieved from information contained in the hook or in the data itself;
+  - 3) otherwise, the OD value shall be set to infinite.
+- b) Each SEndPoint shall be initialised with the Original Size (OS) length value on the corresponding axis, which is retrieved as follows:
+  - 1) If the OS is encoded within the component object:
+    - i) if the length of the OS is provided on an axis, this value shall be used for this spatial axis;
+    - ii) otherwise, the length of the OS on this axis shall be set to 0.
+  - 2) For an rt-content, if the OS is not encoded within the content object, the OS value may be retrieved from information contained in the hook or in the data itself.
+
+NOTE – For a multiplexed content object, the OS of the global multiplexed data is used. The OS may be encoded individually in each stream within a multiplexed content object. This information should not be used to set the OS of the rt-mux. It is just a help for an MHEG Engine to manipulate and present a stream.
+
+- 3) Otherwise, the OS length value shall be set to 0 on each axis.
+
+The following OGU along each OPS axis are defined:
+
+- the GTU along the OPS temporal axis is called Original GTU (OGTU);
+- the GSU along each OPS spatial axis is called Original GSU (OGSU);
+- the GVU along the OPS-AVR is called Original GVU (OGVU).
+
+### 9.2.2 Initialisation of GF
+
+The scaling factors associated with the OPS axes shall be initialised as follows:
+
+- The GTF shall be initialised to 1. It may be changed by the use of the Set GTF action.
+
+NOTE 1 – For example, if the GTF changes from 1 to 10, 1 unit of RGTU lasts 10 times longer than before the change. If the GTF changes from 1 to 1/10, 1 unit of RGTU lasts 10 times shorter than before the change. A GTF value of 0 has the effect of reducing the rt-component duration to an infinitesimal small duration in the RPS, because the whole rt-component duration is perceived within 0 RGTU.
+
+- The GSF on each OPS spatial axis shall be initialised to 1. It may be changed by the use of the Set GSF action.
+
+NOTE 2 – For example, if the GSF changes from 1 to 2 on an axis, 1 OGSU is to be mapped on 2 RGSU on this axis. So the rt-component is perceived twice as large on this axis. A GSF value of 0 on all axes has the effect of reducing the rt-component perception to an infinitesimal small size in the RPS, because the whole rt-component is being perceived within 0 RGSU.
+
+- The GVF shall be initialised to 1. It can be changed by the use of the Set GVF action.
+
+NOTE 3 – For example, if the GVF changes from 1 to 2, 1 OGVU is to be mapped on 2 RGVU. So the rt-component is perceived twice as loud. A GSF value of 0 has the effect reducing the rt-component perception to an infinitesimal small volume in the RPS, because the rt-component volume is being perceived in 0 RGVU.
+
+### 9.2.3 Initialisation of attributes for rt-components
+
+For each rt-component, the following attributes are defined when the OPS is created:
+
+- OD: Defines the initial duration of the rt-component. Its value is retrieved as explained above.
+- Original Visible Duration (OVD): It is a subset of the OD. It defines the part of the OD which is perceived by the user. It shall be initialised to the OD value and may be changed by the use of the Set OVD action.
+- OS: Defines the initial size of the rt-component. Its value is retrieved as explained above.
+- Original Visible Size (OVS): It is defined as a size and then positioned within the OS. The portion of the OS which fits within the OVS is perceived by the user. The portion of the OS that is outside the OVS is clipped. If the OVS exceeds the limits of the OS, the exceeding portion of the OVS is filled by the background of the rt-component. The OVS shall be initialised to the OS value and positioned at the origin of the OS. The size may be changed by the use of a Set OVS action. The position may be changed by the use of the Set OVS Position action.
+
+NOTE – The background of the rt-component is not defined by ISO/IEC 13522-1. The background may be either retrieved from the hook or the data of the component object. A Set Style action can also be used by the author to set a catalogued background style.
+
+### 9.2.4 Initialisation of attributes for rt-contents
+
+For each rt-content the following attributes shall be defined when the OPS is created:
+
+- OV: Defines the initial volume of the rt-content. Its value is retrieved as follows:
+  - 1) if the OV is encoded within the content object, this value is used;
+  - 2) if not, the OV value may be retrieved from information contained in the hook or in the data itself;
+  - 3) otherwise, the OV value is set to the minimum value of the AVR.
+- Current Volume (CV): It corresponds to the volume which will be perceived by the user. It is initialised to the OV value and may be changed by the use of the Set CV action.
+
+NOTE – When an rt-mux is responsible for the presentation of several streams, it is up to the demultiplexing process and the GUI to keep the coherence between the duration, size and volume of the rt-mux itself and the duration, size and volume of each stream selected for this rt-mux.
+
+To ensure the final presentation, the duration and the volume that are encoded within each rt-content shall be expressed in 1 ms (PTU) and 1 dB (PVU), respectively. If the duration and the volume are retrieved from the hook, these values are translated and expressed in 1 ms (PTU) and 1 dB (PVU), respectively.
+
+## 9.3 Channel Presentation Space (CPS)
+
+The CPS shall be initialised as follows:
+
+- The TEndPoint shall be initialised with the CPS Duration value retrieved as follows:
+  - a) if the action Set CPS is targeted to this channel and contains a CPS Duration parameter, this value shall be used;
+  - b) otherwise, the CPS Duration value is set to infinite.
+- Each SEndPoint shall be initialised with the CPS Size length value on the corresponding axis, which is retrieved as follows:
+  - a) If the action Set CPS is targeted to this channel and contains a CPS Size parameter, the following applies:
+    - i) if the length of the CPS Size is provided on an axis, this value is used for this spatial axis;
+    - ii) otherwise, the length of the CPS Size on this axis is set to 0.
+
+- b) Otherwise, the CPS Size length value on each axis is set to the default SEndPoint value provided by this Recommendation.
+
+When different MHEG objects are generated by different authors and take place in the same application, if each of these authors is using the default channel, it is recommended that all the authors are aware of the current CPS definition of the default channel, if it has been changed.
+
+- 3) The AVR is set to the AVR value provided by this Recommendation.
+
+There is no scaling factor associated with the CPS axes.
+
+## 9.4 Relative Presentation Space (RPS)
+
+The Relative PS of an rt-component is the PS in which the rt-component is assigned and projected. Each rt-component is assigned to only one RPS at a given time. The following RPS are defined:
+
+- 1) Parent RPS (PRPS): A socket may be projected within the OPS of its rt-composite parent, in order to describe a composition in time, space or audio. This can be repeated recursively, if the rt-composite parent is itself an rt-composite socket.
+- 2) Channel RPS (CRPS):
+  - a) a socket may also be projected directly within a CPS when this socket does not participate to the composition in time, space or audio described by its parent;
+  - b) each root rt-composite is projected into a CPS.
+
+Initially, each root rt-component is assigned to the default channel, and each socket is assigned to its parent rt-composite PS. This RPS assignment may be changed by the use of the Set RPS Assignment action.
+
+The following RGU along each RPS axis are defined:
+
+- the GTU along the RPS temporal axis is called Relative GTU (RGTU);
+- the GSU along each RPS spatial axis is called Relative GSU (RGSU);
+- the GVU along the RPS AVR is called Relative GVU (RGVU).
+
+The attributes defined for each rt-component within the OPS are projected into the assigned RPS as follows:
+
+- Projected OD (POD): Projection of the OD in the RPS and is calculated as follows:  $OD \times GTF = POD$ .
+- Projected Visible Duration (PVD): Projection of the VD is calculated as follows:  $OVD \times GTF = PVD$ .
+- Projected OS (POS): Projection of the OS in the RPS and is calculated as follows:  $OS \times GSF = POS$ .
+- Projected Visible Size (PVS): Projection of the OVS and is calculated as follows:  $OVS \times GSF = PVS$ . The PVS value can also be set directly by the use of the Set OVS action with the OVS Proj Strategy attribute as “calculated”.
+
+The attribute defined for each rt-content within the OPS is projected into the assigned RPS as follows:
+
+- Projected Current Volume (PCV): Projection of the CV in the RPS and is calculated as follows:  $CV \times GVF = PCV$ .
+
+## 9.5 CPS mapping
+
+Each CPS is a virtual space. It is for the MHEG engine to assign a physical PS to a virtual space, and to convert virtual coordinates (GU) to physical one.
+
+Each CPS is assigned to a physical PS by the MHEG engine. The descriptor object may provide information to facilitate this mapping such as:
+
+- An expected media type mapping may be provided to facilitate the assignment to a physical PS. The MHEG engine associates the CPS with physical devices such as TV sets, workstations, cameras, windows, loudspeakers and microphones.
+
+- A recommended resolution for the physical PS axes may be provided for satisfactory rendition: x-resolution, y-resolution, z-resolution and t-resolution.  
+Authors should take into account the limited possibilities of minimum resource equipment, and not require unduly fine resolutions.
+- A recommended audio dynamic range and a recommended minimum and maximum frequency required for playback may be provided to present audible data with an appropriate amplitude.
+
+The virtual coordinates shall be converted to physical coordinates as follows:
+
+- The CPS temporal axis is mapped to a physical temporal axis. The physical temporal units are expressed in milliseconds. 1 CGTU is mapped to 1 PTU.
+- The CPS spatial axes are mapped to physical spatial axes. The physical spatial units depend on each physical PS, e.g. a pixel, 1 millimetre. 1 CGSU is mapped to 1 PSU.  
+In performing the mapping of each spatial axis onto the physical space, the MHEG engine is responsible that the direction of each spatial axis (see Figure 11) will be correctly perceived by the user. Therefore, considering a CPS-Y axis defined as [0, 65535] in the upward direction, it might be required to map this Y axis onto a physical range [0, 479] in the downward direction for a computer display.
+- The CPS-AVR is mapped on a physical AVR. The physical audible volume units are expressed in decibels [dB] with respect to the physical AVR's limit. 1 CGVU is mapped to 1 PVU.
+
+## 10 Generic identification mechanism
+
+MHEG provides generic mechanisms to identify any MHEG entity, data or stream (see Figure 13).
+
+There are three types of identification mechanisms:
+
+- **External identification:** This identification is not encoded within an MHEG object. The external identifications can be decoded for reference purposes without having to decode the MHEG object (see 10.1).
+- **Internal identification:** This identification is encoded within the MHEG object. The internal identification cannot be discovered until an MHEG object is decoded (see 10.2).
+- **Symbolic identification:** This identification may replace any other external or internal identification (see 10.3).
+
+NOTE – Do not confuse external and internal identification with remote and local objects. A local or remote object may have an external or an internal identification.
+
+![A hierarchical diagram titled 'Generic Identification Mechanism'. It branches into three categories: 'External Identification', 'Internal Identification', and 'Symbolic Identification'. Under 'External Identification' is a list: 'Public Identifier', 'System Identifier'. Under 'Internal Identification' is a list: 'MHEG Identifier', 'Root Rt Identifier', 'Channel Identifier', 'Composition Element Index', 'Container Element Identifier', 'Socket Identifier', 'Stream Identifier'. Under 'Symbolic Identification' is a list: 'Alias'. The diagram is labeled 'T0825600-96/d013' at the bottom right.](71b0a68b4dd64961465d2b0e790538de_img.jpg)
+
+```
+
+graph TD
+    GIM[Generic Identification Mechanism] --> EI[External Identification]
+    GIM --> II[Internal Identification]
+    GIM --> SI[Symbolic Identification]
+    
+    EI --- EI_L["Public Identifier<br/>System Identifier"]
+    II --- II_L["MHEG Identifier<br/>Root Rt Identifier<br/>Channel Identifier<br/>Composition Element Index<br/>Container Element Identifier<br/>Socket Identifier<br/>Stream Identifier"]
+    SI --- SI_L["Alias"]
+  
+```
+
+T0825600-96/d013
+
+A hierarchical diagram titled 'Generic Identification Mechanism'. It branches into three categories: 'External Identification', 'Internal Identification', and 'Symbolic Identification'. Under 'External Identification' is a list: 'Public Identifier', 'System Identifier'. Under 'Internal Identification' is a list: 'MHEG Identifier', 'Root Rt Identifier', 'Channel Identifier', 'Composition Element Index', 'Container Element Identifier', 'Socket Identifier', 'Stream Identifier'. Under 'Symbolic Identification' is a list: 'Alias'. The diagram is labeled 'T0825600-96/d013' at the bottom right.
+
+Figure 13/T.171 – Overview of generic identification mechanism
+
+## 10.1 External identification
+
+This identification mechanism is not defined by this Recommendation and is not encoded within an MHEG object.
+
+NOTE – Distinguish clearly between identification and references. The external identification is not encoded in the MHEG object, but the reference to the MHEG object is encoded within an MHEG object, even if it uses an external reference.
+
+This identification mechanism may be used to identify any MHEG object or data not included in a content or a script object.
+
+This technique is defined in ISO 8879 “Formal Public Identifiers”, and ISO/IEC 9070 “Registration procedures for public text owner identifiers” that provides both ASN.1 and SGML notation for the representation of registered owner identifiers. The external identifier consists of:
+
+- a public identifier (see 10.1.1);
+- a system identifier (see 10.1.2).
+
+### 10.1.1 Public identifier
+
+A public identifier is a character string whose syntax is given by 10.2/ISO 8879. In this Recommendation, a public identifier is encoded as an ASN.1 PrintableString.
+
+NOTE – The encoding method for public identifiers of this Recommendation simplifies that of ISO/IEC 9070 defined in informative Annex D in order to ease implementation.
+
+The example of a public identifier in Figure 14 identifies the image of Lena, the lady with the hat, as it is stored in the system. The example of a public identifier in Figure 15 identifies a remote object requiring telecommunication access. A complete example of a public identifier is given in Figure 16.
+
+![Diagram of a public identifier for a non-registered owner. The string is broken down into segments with vertical lines. From left to right: 'Not a registered owner' points to the first segment; 'Owner identifier: local system' points to the second segment; 'Public text class: not SGML' points to the third segment; 'Public text description: name of image' points to the fourth segment; 'Public text language: English' points to the fifth segment; 'Public text display version: Encoding method (8-bit PCM, row-by-row, no compression)' points to the sixth segment.](7156cf400ef0e19f9d06a5d0549834a3_img.jpg)
+
+**-//local//NONSGML Lena//EN//IAX**
+
+Public text display version:  
+Encoding method (8-bit PCM, row-by-row, no compression)
+
+Public text language: English
+
+Public text description: name of image
+
+Public text class: not SGML
+
+Owner identifier: local system
+
+Not a registered owner
+
+T0825610-96/d014
+
+Diagram of a public identifier for a non-registered owner. The string is broken down into segments with vertical lines. From left to right: 'Not a registered owner' points to the first segment; 'Owner identifier: local system' points to the second segment; 'Public text class: not SGML' points to the third segment; 'Public text description: name of image' points to the fourth segment; 'Public text language: English' points to the fifth segment; 'Public text display version: Encoding method (8-bit PCM, row-by-row, no compression)' points to the sixth segment.
+
+**Figure 14/T.171 – Example of a public identifier for a non-registered owner**
+
+![Diagram of a public identifier for a URL. The string is broken down into segments with vertical lines. From left to right: 'Not a registered owner' points to the first segment; 'Owner identifier: IETF Request for comments 1738, “Uniform Resource Locators” (URL)' points to the second segment; 'URL indicating access protocol, host name and file name' points to the third segment. An arrow points from the explanatory text above to the double slash in the URL segment.](3252037b597c9317aced0feed4cb5af0_img.jpg)
+
+This double slash following “ftp:” is a part of the URL  
+and not an ISO 9070 separator
+
+**-//IETF RFC 1738/ftp://site.university.edu/MHEG/new.mhg**
+
+URL indicating access protocol, host name and file name
+
+Owner identifier: IETF Request for comments 1738,  
+“Uniform Resource Locators” (URL)
+
+Not a registered owner
+
+T0825620-96/d015
+
+Diagram of a public identifier for a URL. The string is broken down into segments with vertical lines. From left to right: 'Not a registered owner' points to the first segment; 'Owner identifier: IETF Request for comments 1738, “Uniform Resource Locators” (URL)' points to the second segment; 'URL indicating access protocol, host name and file name' points to the third segment. An arrow points from the explanatory text above to the double slash in the URL segment.
+
+**Figure 15/T.171 – Example of a public identifier for a URL  
+(Uniform Resource Locator)**
+
+![Diagram showing the breakdown of a public identifier string into its components. The string is +//ISO 9070/RA::-1::RR::Hatz::HATS//NONSGML Lena//EN//ISO 13522-1. Vertical lines point to specific segments: 'Registered owner' points to the start; 'Owner identifier assigned by ISO/IEC 9070 procedure' points to +//ISO 9070/RA::-1::; 'Registration number \](cbab05075b3d7dc0d27c4cbb0c914a94_img.jpg)
+
+**+//ISO 9070/RA::-1::RR::Hatz::HATS//NONSGML Lena//EN//ISO 13522-1**
+
+T0825630-96/d016
+
+Diagram showing the breakdown of a public identifier string into its components. The string is +//ISO 9070/RA::-1::RR::Hatz::HATS//NONSGML Lena//EN//ISO 13522-1. Vertical lines point to specific segments: 'Registered owner' points to the start; 'Owner identifier assigned by ISO/IEC 9070 procedure' points to +//ISO 9070/RA::-1::; 'Registration number \
+
+**Figure 16/T.171 – Example of a public identifier for a registered owner**
+
+In Figure 16, imagine a Ruritanian hat manufacturer called Hatz who applies to the ISO/IEC 9070 Registration Authority and is issued the registration number –1. The company follows the recommended conventions and decides to begin the owner-name components with: “/RR:Hatz”.
+
+The Hatz company decides to set up a group of public MHEG objects containing description of the hats. The additional owner-name component is HATS, thus making the full owner name: ISO/IEC 9070/RA::-1::RR::Hatz::HATS.
+
+### 10.1.2 System identifier
+
+A system identifier provides a system-dependent means of identifying a particular piece of information within the system. It may also be used to indicate the system that supplies the information. The character set and the syntax of the system identifier is not defined by this Recommendation and depends on the system. This Recommendation encodes the system identifier as an ASN.1 OctetString.
+
+NOTE – The system identifier may be used to describe a database or telecommunications request for an object.
+
+Figure 17 shows that identification mechanisms may be combined. This link object has an internal identification encoded internally using an MHEG identifier, and an external identification encoded externally to the object using an external identifier.
+
+![Diagram of a link object. A cylinder labeled 'Link object' contains a box labeled 'MHEG ID = 19'. An arrow labeled 'Handled by an external process' points to the cylinder. Above the cylinder, text reads 'External identifier', 'Public ID = No', and 'System ID = c:\mydir\myobject.mhg'.](367378559e35017a5e1a6f5c30798c5a_img.jpg)
+
+T0825640-96/d017
+
+Diagram of a link object. A cylinder labeled 'Link object' contains a box labeled 'MHEG ID = 19'. An arrow labeled 'Handled by an external process' points to the cylinder. Above the cylinder, text reads 'External identifier', 'Public ID = No', and 'System ID = c:\mydir\myobject.mhg'.
+
+**Figure 17/T.171 – Example of a system identifier without public identifier**
+
+## 10.2 Internal identification
+
+This identification mechanism is encoded within MHEG objects.
+
+The following internal identifications are provided in ISO/IEC 13522-1 to identify an outer entity:
+
+- **MHEG Identifier:** Identify any MHEG object (see 17.2);
+- **Root Rt Identifier:** Identify any root rt-object (see 10.2.2);
+- **Channel Identifier:** Identify any channel (see 10.2.3).
+
+The internal identification is also used to identify an element within a constructed entity. For that purpose, the following is defined:
+
+- An **index**: To provide an identification for an element of a given generation within a constructed entity. Each element is indexed within a generation by sequential integers starting from one. The following notation is used to express index within this Recommendation: `outer_object_identification.i`, where “i” indicates the index within the outer object, e.g. the third element of container object with MHEG ID 1000 is expressed by 1000.3.
+- A **tail**: To provide an identification of an element within a hierarchy of constructed entities. A tail is a list of indexes and it designs a path from an outer entity through an element. Each index corresponds to an index of an element within the constructed entity. Successive indexes correspond to nested elements. The last index in the list is the index of the element to be identified. The following notation is used to express tail: `outer_object_identification.i1.i2.i3....in`, where “i1.i2.i3....in” is a list of indexes indicating the path from the outer object through the element.
+
+The following internal identifications are also provided in ISO/IEC 13522-1 to identify an element:
+
+- 1) **Composition Element Index:** Identify any element of a composite (see 10.2.4);
+- 2) **Container Element Identification:** Identify any element of a container (see 10.2.5);
+- 3) **Socket ID:** Identify any socket (see 10.2.6);
+- 4) **Stream ID:** Identify any stream within a multiplexed content object (see 10.2.7).
+
+### 10.2.1 MHEG identifier
+
+An MHEG identifier may be assigned to each MHEG object. When used, the MHEG Identifier shall be encoded within the MHEG object and shall be composed of the following:
+
+- An optional **application identifier**, which is provided by the application designer. It shall be encoded in this Recommendation as an ASN.1 octet string.
+- An **MH number**, which uniquely identifies an MHEG object within an application. The mh number shall be encoded as an integer. When the MHEG identifier is present, it is mandatory.
+
+A reserved MHEG identifier is provided to identify a null MHEG object: “Null-Mh”.
+
+It is the object designer’s responsibility to ensure that MHEG identifiers are unique among the MHEG objects.
+
+The following notation is used to express MHEG identifiers: a1.a2.a3...an-m, where “a1.a2.a3...an” represents the application identifier and m represents the mh number. When the application identifier is omitted, the MHEG identifiers are expressed using the following notation m.
+
+**Example:** A content object may have the following MHEG identifier: 129.63.24.2-49, and another composite object may have the following MHEG identifier: 700, which means that this composite has no application identifier.
+
+### 10.2.2 Root Rt-ID
+
+A root rt identifier is assigned to each root rt-object. This identifier is mandatory. This identifier is composed of the following:
+
+- The **model object identification**, which identifies the model object. Any one of the identifications provided by this Recommendation to identify an MHEG object may be used to identify this model object, e.g. MHEG identifier, Container Element Index, External ID, Alias.
+- An **rt number**, which is an integer provided by the author.
+
+A reserved root rt identifier is provided to identify a null rt-object: “Null-Root-Rt”.
+
+It is the object designer’s responsibility to ensure that root rt identifiers are unique.
+
+The uniqueness of rt numbers is required at a given instant. An rt number may be reused once this number is again available, i.e. once the rt-object that was using it is deleted. It is not possible to have, at a precise instant, two rt-objects with the same rt number.
+
+The following notation is used to express root rt identifiers: model\_object\_identification:r, where model\_object\_identification can be any one of the identification provided by this Recommendation to identify an MHEG object and “r” is the rt number, e.g. the first rt-composite object created from the composite object identified by MHEG identifier: 700 has the following root rt identifier: 700:1. The third rt-content object created from the content object identified by MHEG identifier: 129.63.24.2-49 has the following rt identifier 129.63.24.2-49:3.
+
+### 10.2.3 Channel identifier
+
+A channel identifier is assigned to each channel. This identifier is mandatory. This identifier is an integer.
+
+A reserved channel identifier is provided to identify the default channel: “Default-Channel”.
+
+It is the object designer’s responsibility to ensure that channel identifiers are unique.
+
+### 10.2.4 Composition element index
+
+The index facility is used in a composite object to identify each element within the composition.
+
+Each composite object defines one generation. The indexes of elements with non-empty associated models are provided by the author. The missing indexes are automatically provided by the MHEG engine; such elements are considered as elements with an empty associated model.
+
+In Figure 18, the five elements in composite object 700 are identified with indexes 1, 2, 3, 4 and 5. The four elements in composite object 701 are identified with indexes 1, 2, 3 and 4. The single element in composite object 702 is identified by index 1. Comp 701 and Comp 702 that are associated models of Comp 700, and Content 7000 that is an associated model of Comp 702, are referenced rather than included. They are identified by using either their own identifier or the index of the composite elements in which they are associated. Figure 18 does not show the composition behaviour in composite objects.
+
+NOTE – The element index is typically used during the construction of the rt-composite.
+
+![Figure 18/T.171 – Indexing of elements in a composite object. The diagram shows three hierarchical structures. Top left: 'Comp 700' (black square) has five children: 'Index 1' (FILE oval), 'Index 2' (empty square, labeled 'Comp 701'), 'Index 3' (OPTION oval), 'Index 4' (empty square, labeled 'Comp 702'), and 'Index 5' (HELP oval). Top right: 'Comp 702' (black square) has one child: 'Index 1' (Content 7000 oval). Bottom left: 'Comp 701' (black square) has four children: 'Index 1' (Open oval), 'Index 2' (New oval), 'Index 3' (Close oval), and 'Index 4' (empty square). Bottom right: 'Content 7000' (black circle) has one child: 'Easy' (rounded rectangle).](c2c4e63ebb9afc1ab64e39a159890e0f_img.jpg)
+
+Figure 18/T.171 – Indexing of elements in a composite object. The diagram shows three hierarchical structures. Top left: 'Comp 700' (black square) has five children: 'Index 1' (FILE oval), 'Index 2' (empty square, labeled 'Comp 701'), 'Index 3' (OPTION oval), 'Index 4' (empty square, labeled 'Comp 702'), and 'Index 5' (HELP oval). Top right: 'Comp 702' (black square) has one child: 'Index 1' (Content 7000 oval). Bottom left: 'Comp 701' (black square) has four children: 'Index 1' (Open oval), 'Index 2' (New oval), 'Index 3' (Close oval), and 'Index 4' (empty square). Bottom right: 'Content 7000' (black circle) has one child: 'Easy' (rounded rectangle).
+
+T0825650-96/d018
+
+**Figure 18/T.171 – Indexing of elements in a composite object**
+
+### 10.2.5 Container element identification
+
+The index facility is used in a container object to identify each element within the container. When a container object contains a hierarchy of embedded container objects, the tail facility is used to identify the embedded elements in the hierarchy of container objects.
+
+Each container object defines one generation. The indexes of elements are automatically provided by the MHEG engine and are indexed in each generation from one, sequentially.
+
+An element in a container object is always an MHEG object. It is possible that a container element, which is an MHEG object, is already assigned another identifier, e.g. an external identifier or an MHEG identifier. In this case, this element has two different identifications, either as an element of a container or as an MHEG object directly.
+
+**NOTE** – The index or tail within a container is typically used to obtain rapid access to elements of a container. When a Prepare action is targeted to an MHEG object using its identification within a container, e.g. 1000.3, element 3 of container 1000, the object may be picked out of the container with minimal processing by the MHEG engine. If an MHEG identifier is encoded within this object, this identifier is available to the MHEG engine as soon as the object is prepared. It is recommended but not required, that further actions on this object typically use the MHEG identifier rather than the container indexing.
+
+In Figure 19, the elements defined in the container object are MHEG objects; they are identified by an index or a tail within the container, e.g. index 1 of container 800 or tails 1000.8.1 and 800.1 identifies the link object with MHEG-ID 810. An MHEG identifier and an external identifier may be also provided for each object.
+
+### 10.2.6 Socket identifier
+
+The index facility is used to identify each element of a given generation of an rt-composite. The tail facility is used in a root rt-composite object to identify each element within the rt-composite.
+
+Each root rt-composite defines a complete hierarchy. In each generation of an rt-composite, the sockets are indexed from one, sequentially and deduced from the composite object model. The tail is used to identify each socket indicating the path from the root rt-composite through the socket.
+
+Figure 20 shows an rt-composite that is a result of a New action applied on an rt-composite made from the model composite object 700 shown in Figure 18. The rt number is 8. This rt-composite is made either directly from the composite object 700 or from the same object considered as element 7 in container 1000.
+
+Container Object: MHEG ID = 1000
+
+![](3766b291e69420b0437ae278b057b5ee_img.jpg)
+
+|                                            |                                                                                                                                                                                                       |               |
+|--------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------|
+| Container start-up<br>Container close-down |                                                                                                                                                                                                       |               |
+| Index 1                                    | Descriptor object                                                                                                                                                                                     | MHEG ID = 100 |
+| Index 2                                    | Action object                                                                                                                                                                                         | MHEG ID = 200 |
+| Index 3                                    | Script object                                                                                                                                                                                         | MHEG ID = 300 |
+| Index 4                                    | Link object                                                                                                                                                                                           | MHEG ID = 400 |
+| Index 5                                    | Content object                                                                                                                                                                                        | MHEG ID = 500 |
+| Index 6                                    | Multiplexed content object                                                                                                                                                                            | MHEG ID = 600 |
+| Index 7                                    | Composite object                                                                                                                                                                                      | MHEG ID = 700 |
+| Index 8                                    | <div>Container object MHEG ID = 800</div> <div> <div>Container start-up<br/>Container close-down</div> <div> Index 1 Link object MHEG ID = 810<br/> Index 2 Script object MHEG ID = 820 </div> </div> |               |
+
+T0825660-96/d019
+
+**Figure 19/T.171 – Indexing of elements in a container object**
+
+![A hierarchical tree diagram showing the indexing of sockets. The root node is a black square labeled 'root rt-composite Identifier = 700:8'. It has five children: 'Index 1' (FILE), 'Index 2' (a black square), 'Index 3' (OPTION), 'Index 4' (a black square), and 'Index 5' (HELP). The 'Index 2' node has four children: 'Index 1' (Open), 'Index 2' (Close), 'Index 3' (New), and 'Index 4' (an empty square). The 'Index 4' node has one child: 'Index 1' (Easy).](50ef8602c7c9edd2da0e2133e772c2a2_img.jpg)
+
+root rt-composite Identifier = 700:8
+
+```
+
+graph TD
+    Root["root rt-composite Identifier = 700:8"]
+    Root --- I1_1["Index 1  
+FILE"]
+    Root --- I2_1["Index 2  
+[Black Square]"]
+    Root --- I3_1["Index 3  
+OPTION"]
+    Root --- I4_1["Index 4  
+[Black Square]"]
+    Root --- I5_1["Index 5  
+HELP"]
+    
+    I2_1 --- I1_2["Index 1  
+Open"]
+    I2_1 --- I2_2["Index 2  
+Close"]
+    I2_1 --- I3_2["Index 3  
+New"]
+    I2_1 --- I4_2["Index 4  
+[Empty Square]"]
+    
+    I4_1 --- I1_3["Index 1  
+Easy"]
+  
+```
+
+A hierarchical tree diagram showing the indexing of sockets. The root node is a black square labeled 'root rt-composite Identifier = 700:8'. It has five children: 'Index 1' (FILE), 'Index 2' (a black square), 'Index 3' (OPTION), 'Index 4' (a black square), and 'Index 5' (HELP). The 'Index 2' node has four children: 'Index 1' (Open), 'Index 2' (Close), 'Index 3' (New), and 'Index 4' (an empty square). The 'Index 4' node has one child: 'Index 1' (Easy).
+
+T0825670-96/d020
+
+**Figure 20/T.171 – Indexing of sockets**
+
+The sockets in the first generation are identified by indexes 1, 2, 3, 4 and 5 like the elements in the composite 700 or as tails 700:8.1, 700:8.2, 700:8.3, 700:8.4 and 700:8.5.
+
+NOTE – These objects can also be identified by tails: 1000.7:8.1, 1000.7:8.2, 1000.7:8.3, 1000.7:8.4 and 1000.7:8.5, because 700:8 can be identified by 1000.7:8. However, see the Note in Container element identification 10.2.5.
+
+The three sockets in the second generation below index 2 of first generation are identified with indexes 1, 2, 3 like the elements in the composite 701 or as tails: 700:8.2.1, 700:8.2.2 and 700:8.2.3.
+
+The socket in the second generation below index 4 of first generation is identified with index 1 as is the element in the composite 702 or as tail: 700:8.4.1.
+
+### 10.2.7 Stream identifier
+
+A stream identifier is used to identify each stream within a multiplexed content object. This identifier is expressed as a tail and designs a path from an outer stream to an inner stream within the multiplexed data.
+
+It is the object designer's responsibility to ensure that stream identifiers are unique within the same multiplexed data.
+
+## 10.3 Symbolic identification
+
+This Recommendation provides a means of assigning a symbolic identification that may be used to replace any other internal or external identification. This symbolic identification is called alias.
+
+Alias provides the following characteristics:
+
+- Addressing entities by another name.
+- Regrouping entities on which the same actions are to be applied at the same time.
+- Multievaluation of objects using a delayed assignment of alias. A complete application may be described by an author using alias. The real assignment of the entity may be done later dynamically.
+
+This is particularly useful for multilingual/internationalisation, multiresolution media format, multiversion of objects and multiencoded media format. For example, an author provides one object for the different languages, and the actions are described by using aliases. Then, Set Alias actions are used to assign the correct language when needed.
+
+An alias is a string that is used as a convenient alternative for an other identification format. An alias is assigned by an author using the Set Alias action.
+
+#### NOTES
+
+1 – This alias is different from the object name in the MH-object class.
+
+2 – For example, Set Alias(START, "e:\appli\start-up.mhg"). This alias is an alternative identification for the external ID identified as "e:\appli\start-up.mhg".
+
+3 – For example, Set Alias(OPTION, 700:8.2). This alias is an alternative identification for the socket 2 of root rt-composite number 8 created from composite model 700 (see Figure 20).
+
+A given entity may have several aliases assigned at the same time. A given alias may be assigned to several entities at the same time.
+
+## 11 Generic reference mechanism
+
+Many MHEG entities, data and streams need to be referenced either from another MHEG object or as a parameter of an action. Targets of action also address the MHEG entities using their reference.
+
+### 11.1 Generic reference using generic identification
+
+The following references are defined:
+
+- 1) **External ID Reference:** Reference to an MHEG object or a data using its External ID (see 10.1).
+- 2) **MHEG ID Reference:** Reference to an MHEG object using its MHEG-ID (see 17.2).
+
+The reference to an MHEG identifier cannot be resolved until the referenced MHEG object is decoded. A using application may provide a mechanism to resolve this reference without decoding the object, e.g. using a table of correspondence between a location of an MHEG object and its MHEG identifier.
+
+- 3) **Root Rt-ID Reference:** Used to reference a root rt-object. It is specified as a reference to the model object followed by a reference to an rt-number. The model object is referenced using one of the references defined for an MHEG object. The reference to an rt number is one of the following:
+  - a) An rt number: Used to reference a root rt-object.
+  - b) The constant \*: Used to reference, at the moment when this reference is solved, all the root rt-objects created from the specified model object.
+  - c) The constant ?: Used to reference a single dynamically determined rt number (see 11.3).  
+For example, taking into account the composite object defined in Figures 18 and 19:
+    - i) 700:\* represents a reference to all the root rt-composite objects created from this composite object model at the moment of the resolution of this reference;
+    - ii) 700:? represents a reference to a dynamically determined root rt-composite object created from this composite object model.
+- 4) **Channel ID Reference:** Reference to a channel using its Channel ID (see 10.2.3).
+- 5) **Tail Reference:** This reference cannot be used directly by the author; it is part of the Container Element Reference and of the Socket ID Reference. It is defined as one of the following:
+  - a) Tail: Used to reference a given element using its tail identification (see 11.1).
+  - b) Tail complement: Defined as either **children** or **descendants**. When used alone, it references the child elements, i.e. one generation or all generations (the descendant elements of the outer entity itself).
+  - c) Tail followed by a tail complement: The tail complement, in that case, applies to the element referenced using the tail identification. This element shall be itself a constructed entity, i.e. another container object or an rt-composite socket.
+- 6) **Container Element Reference:** Reference to an MHEG object using its Container Element. It is specified as a reference to the container object followed by a **Tail Reference**. The container object is referenced using one of the references defined for an MHEG object. The tail reference allows an author to reference:
+  - a) a single MHEG object, or an element of the container;
+  - b) the children of the outer container object;
+  - c) the children of a container object which is an element of the outer container object;
+  - d) the descendants of the outer container object;
+  - e) the descendants of a container object that is an element of the outer container object.
+- 7) NOTE 1 – In Figure 19, 1000.8.children or 800.children represents a reference to the two elements within this embedded container, i.e. link object 810 and multiplexed content object 820.
+- 8) NOTE 2 – 1000.descendants represents a reference to all the elements within container 1000 and within the embedded container 800.
+- 9) NOTE 3 – The reference to a container element cannot be resolved until the referenced container object is decoded. However, if the author has provided an offset information within the descriptor (see 0.5.3.9) for a container element, the MHEG engine may use this offset information to decode only the specified container element without decoding the rest of the container object.
+- 10) NOTE 4 – If an author has provided additional identification to a container element, e.g. an MHEG identifier, this container element may be also referenced using one of the references defined for an MHEG object.
+- 11) **Socket ID Reference:** Used to reference a socket. It is specified as a reference to the root rt-composite followed by a **Socket Tail Reference**. The root rt-composite is referenced using a Root Rt ID Reference. The socket tail reference allows an author to reference:
+  - a) a single socket;
+  - b) the children of the root rt-composite;
+
+- c) the children of an rt-composite socket within the root rt-composite;
+  - d) the descendants of the root rt-composite;
+  - e) the descendants of an rt-composite socket within the root rt-composite.
+- 12) **Socket Tail Reference:** This reference cannot be used directly by the author; it is part of the Socket ID Reference. It is defined as one of the following:
+- a) A tail: Used to reference a given socket using its tail identification (see above).
+  - b) A socket tail complement: It is defined as one of the following:
+    - i) The constants provided by a tail complement, i.e. children or descendants (see above). Used alone, the tail complement applies to the root rt-composite itself.
+    - ii) The constant **?child** used to reference a single dynamically determined socket within the root rt-composite itself.
+    - iii) The constant **?descendant** used to reference a single dynamically determined socket within the descendant sockets of the root rt-composite itself. When ?child or ?descendant is used, the technique to determine the socket is the same as for ? (see 11.3). The individualisation phase, in that case, is made on each child or descendant socket of the specified root rt-composite.
+
+The ?child and ?descendant facilities may be used as follows: for example, a root rt-composite describes a menu; each socket is an item. When one of the items is selected, the same behaviour is specified. This behaviour is processed individually each time one of the items is selected. This is described in a single link using the ?descendant or ?child facilities. The number of sockets children or descendants may be changed during the life of the menu; the link always applies.
+  - c) A tail followed by a socket tail complement: The tail complement, in that case, applies to the socket referenced using the tail identification. This socket shall be an rt-composite socket.
+- 13) NOTE 5 – In Figure 20, 700:8.children represents a reference to all the child elements of the root rt-composite (indexes 1 to 5, first generation).
+- 14) NOTE 6 – 700:8.2.children represents a reference to all the child sockets of the rt-composite socket 700:8.2 (indexes 1 to 4, 2nd generation).
+- 15) NOTE 7 – 700:8.descendants represents a reference to all the descendant sockets of the root rt-composite (all generations).
+- 16) NOTE 8 – 700:?.1 represents a reference to rt-content socket (FILE) of a dynamically determined root rt-composite created from composite object model 700.
+- 17) NOTE 9 – 700:?.descendants represents a reference to all descendant sockets of a dynamically determined root rt-composite created from composite object model 700.
+- 18) NOTE 10 – 700:\*.1 represents a reference to the rt-content socket 1 (FILE) of all the root rt-composite objects created from this composite object model at the moment of the resolution of this reference.
+- 19) NOTE 11 – 700:8.?descendant represents a reference to a single dynamically determined socket between the descendant socket (all generations) of the root rt-composite.
+- 20) NOTE 12 – 700:8.2?child represents a reference to a single dynamically determined socket between the child socket (open, close, new, index) of the rt-composite socket 700:8.2.
+- 21) NOTE 13 – 700:?.?child represents a reference to a single dynamically determined socket between the child socket (one generation) of a dynamically determined root rt-composite created from composite object model 700.
+- 22) **Stream ID Reference:** Reference to a stream using its Stream ID (see 10.2.7).
+- 23) **Alias Reference:** Reference to an MHEG entity or a data or a stream using one of its assigned aliases (see 10.3). The reference to an alias cannot be resolved until the alias has been assigned.
+
+## 11.2 Predefined references
+
+The following predefined reference constants value are also defined:
+
+- 1) **Null-Data**: Reference to a null data.
+- 2) **Null-Mh**: Reference to a null MHEG object.
+- 3) **Null-Root-Rt**: Reference to a null root rt-object.
+- 4) **Default-Channel**: Reference to the default channel.
+- 5) **“This”**: Local reference to a composite or a container within itself. A composite or a container object may be referenced using any one of the referencing techniques defined for an MHEG object (e.g. MHEG-ID reference, container element reference, alias reference, external identifier reference) or by using the “this” facility provided for local referencing purposes within the composite or the container object itself. “This” shall be used only within link and action object; it shall not be used either within a container element reference or within a component object reference of a composition element. The following applies:
+  - a) When the composite or the container object is prepared, “this” takes the value of the composite or the container object identification. When the start-up link, rt start-up and container start-up are activated, the value of “this” is propagated to them.
+  - b) The propagation of the value of “this” to a link object has the effect of replacing each occurrence of “this” within the link condition by the value of “this”.
+  - c) When such a link fires, the value of “this” shall be propagated to its link effect. The following applies:
+    - i) Each occurrence of “this” within the usage value of the macro resolution and within the action object is replaced by the value of “this”. If the action object is a nested action object, any occurrence of “this” within all the embedded action objects is also replaced by the value of “this”.
+    - ii) If the link is a nested link object, the value of “this” is also propagated to the embedded link objects.
+- 6) NOTE 1 – “This” has the role of a local variable within the scope of the composite or the container itself.
+- 7) NOTE 2 – In Figure 18, the availability start-up of the composite object has the following link effect: New this:1, Activate link L1. The link object L1 is defined as follows: TC = this:1.3 becomes selected, LE = Run (this:1.5). When the composite 700 is prepared, the start-up is activated, the root rt-composite number 1 is created and the value this = 700 is propagated to link object L1.
+
+## 11.3 ? reference
+
+? is used in link and action objects to describe an individual behaviour common to all root rt-objects created from a given model object. The advantages of this facility are:
+
+- the behaviour is described only once and applied to all the root rt-objects created from a same model object;
+- the object designer is able to describe an individual behaviour for each root rt-object without knowing the number of root rt-objects that will be created from the given model object;
+- once activated, the link applies to all root rt-objects already created as well as future created root rt-objects;
+- this facility allows a complete independence between all the root rt-objects created from the same model, i.e. they may be presented independently, the behaviour is an individual behaviour attached to each root rt-object.
+
+The reference “model\_object\_identification:?” can be used in a link or in an action object wherever an rt-object reference is allowed. However, the following applies:
+
+- 1) If the link object is not an embedded link, the reference “model\_object\_identification:?” shall be used in the source value of at least one trigger condition in order to assign a usage value to ?.
+
+The composite rt-availability start-up link answers this requirement, its link condition is “this:? becomes available”. All embedded links activated from the rt-availability start-up are active for each new created root rt-composite.
+
+- 2) In an embedded link object, the ? can be used for different model objects, e.g. the following references “model\_object\_identification1:?”; “model\_object\_identification2:?” can be used in the same embedded link object.
+
+It is deprecated to use ? with different model object identifications in a non-embedded link object. Because the ? value is resolved when a trigger condition becomes true and only one trigger condition becomes true at a given time. So, in that case only one ? is resolved and all other references are considered as “undefined” references.
+
+The determination of the rt number to be taken into account in the place of each ? is highly dynamic. When a non-embedded link object is activated, the following phases applies:
+
+- 1) Each link object containing a trigger condition with a source value encoded as “model\_object\_identification:?” is to be evaluated in parallel for each root rt-object created from the indicated model\_object\_identification. For that purpose, all instances of ? with the same model\_object\_identification within the link condition are replaced by a given instance of a root rt-object rt number in each parallel evaluation.
+
+During the activation of such a link object, the root rt-objects created from the indicated model\_object\_identification may vary, i.e. additional root rt-objects may be created or some of them may be destroyed.
+
+- 2) If a trigger condition becomes true for a given root rt-object and if the link condition is satisfied, its rt number becomes the “? usage value”. Each instance of ? with the same model\_object\_identification is replaced by the “? usage value” in the following places:
+  - a) Within the link effect – If the action object defining the link effect is a nested action object, the “? usage value” is also propagated to each instance of the ? with the same model\_object\_identification within the embedded action objects.
+  - b) When an embedded link object is activated from this link object, the following applies:
+    - i) a specific instance of the embedded link object handles this “? usage value”;
+    - ii) the “? usage value” is propagated to each instance of the ? with the same model\_object\_identification within this instance of embedded link;
+    - iii) if this instance of the embedded link object contains some ? not resolved within a trigger condition, the same phases, i.e. 1) and 2) apply;
+    - iv) if some ? remains unresolved after all phases 1) and 2), the corresponding references are to be considered as “undefined”.
+- 3) Phase 1 is processed in parallel on all root rt-objects created from the model object. If the link condition of a nested link object becomes true for two root rt-objects in parallel in phase 1, e.g. 700:3 and 700:4, the phase 2 is to be processed for each ? usage value in parallel. That is, if the link effect activates an embedded link, two instances of this embedded link are handled in parallel for both ? usage values of 700:3 and 700:4.
+
+If the link is deactivated, this link cannot be fired for any “? usage value”.
+
+This example takes into account composite object defined in Figure 18:
+
+- Its start-up may have the following link effect: new 700:3, new 700:9.
+- Its rt-availability start-up link effect is: activate link object L1.
+- Link L1 is an embedded link object, it is defined as follows: TC = 700:?.3 becomes selected, LE = run 700:?.5. This link is used to describe an individual behaviour common to all root rt-composites which may be created from model object 700, i.e. for 700:3, 700:9 but also for any future root rt-composite created from the model 700.
+
+The following applies:
+
+- 1) When the rt-availability start-up is activated, i.e. each time a new root rt-composite is created, an instance of L1 handles this new root rt-composite. The rt number of this new made root rt-composite is considered as the “? usage value” and is transmitted to this instance of L1.
+
+- 2) In fact, there is one instance of link L1 per root rt-composite already created from 700. So we can consider that link L1 is active for all root rt-composite created from 700 and that its trigger is evaluated each time the selection status of the socket 3 of any root rt-composite created from 700 changes.
+- 3) When the trigger of an instance of link L1 becomes true for a root rt-composite, e.g. 700:2, the link condition becomes true and the value of this root rt-composite rt number is considered as the “? usage value”. This value is transmitted to the link effect of this instance of link L1. So the fifth socket of 700:2 becomes running.
+- 4) When both 700:2.3 and 700:3.3 are selected in parallel, two instances of the link L1 are satisfied in parallel, their link effect is to be performed in parallel. That is, socket 5 of 700:2 and socket 5 of 700:3 become running in parallel.
+
+Following is another example:
+
+- Link object L1 is defined as follows: TC = 700:?3 becomes selected, LE = run (700:?5), activate (link object L2, link object L3).
+- Link L2 is an embedded link object defined as follows: LC: 900:3.1 becomes selected AND 700:?2 is running, LE: stop 700:?5 run 700:?2.
+- Link L3 is a more complex embedded link object, it is defined as follows: LC: 999:?1 becomes selected AND (700:?5) is running, LE: stop (999:?1, 700:?5) run (999:?2, 700:?2).
+
+The following applies:
+
+- 1) Instances of Link L1 are handled as explained in the previous example.
+- 2) Consider now that an instance of L1 link condition is satisfied for 700:7, 7 becomes the “? usage value” for composite 700. This value is transmitted to the link effect of this instance of L1. That is, the socket 5 of 700:7 becomes running as in the previous example, but additionally links L2 and L3 are activated.
+- 3) When L2 is activated, an instance of L2 handles the “? usage value” and all appearances of 700:? are replaced by 700:7 in the link effect of this instance. When this instance of link L2 is handled and when its link condition becomes true, i.e. 900:3.1 is selected and 700:7.2 is running, then 700:7.5 is stopped and 700:7.2 becomes running.
+- 4) When L3 is activated, and instance of L3 handles the “? usage value” and all appearances of 700:? are replaced by 700:7 in the link effect of this instance. As one ? is remaining in a trigger condition, the instance of link L3 is evaluated in parallel for all root rt-composites created from 999. If the trigger condition of this instance of L3 is valid for 999:9, the “? usage value” 9 is replaced in this instance and so 999:9.1 and 700:7.5 are stopped and 999:7.2 and 700:7.2 becomes running.
+
+## 12 Generic Value
+
+This clause describes the mechanisms provided by this Recommendation for specifying values in a generic way. The generic values are typically used to express:
+
+- elementary action parameters;
+- get action parameters;
+- conditions;
+- MHEG object attributes.
+
+A generic value may be defined as follows:
+
+- 1) **constant**: A specific constant is also provided to identify an unspecified value: “unspecified”.  
+The “unspecified” value is used in link condition as a comparison value.
+- 2) **evaluated values**: An evaluated value is the result of the process of a get action by the MHEG engine. When the MHEG engine is not able to process a get action, this get action is evaluated as the constant value “undefined”.
+
+The generic values may be stored in and retrieved from the data field of a content object.
+
+The type of a generic value is one of the following:
+
+- Generic boolean (see 12.1);
+- Generic numeric (see 12.2);
+- Generic integer (see 12.3);
+- Generic ratio (see 12.4);
+- Generic string (see 12.5);
+- Generic reference (see 12.6);
+- Generic list (see 12.7).
+
+It is the object designer's responsibility to ensure that the generic values given as parameters of actions conform in type and number to the specification of the parameters as specified in this Recommendation. If the actual parameters do not conform in type or number to what is expected, it is an error and the action shall be ignored.
+
+The type of a generic value determines the following:
+
+- the set of values that it can possibly take;
+- common semantics of these values.
+
+### **12.1 Generic boolean**
+
+A generic boolean value has one of the following values: TRUE, FALSE.
+
+The generic boolean value may be specified as follows:
+
+- a boolean constant;
+- a result of the evaluation of a get action;
+- a result of a logical operation within a link condition;
+- a result of a comparison operation within a link condition.
+
+### **12.2 Generic numeric**
+
+A generic numeric value is a numeric. The design of this Recommendation does not limit the numerical values in any way. The values may be integers, reals or complex; however, the coded representations may impose limitations. The ASN.1 syntax defined in this Recommendation supports only integer values.
+
+NOTE – It is recommended that authors assume this limitation.
+
+The generic numeric value may be specified as follows:
+
+- a numeric constant;
+- a result of the evaluation of a get action.
+
+### **12.3 Generic integer**
+
+A generic integer value shall be an integer.
+
+The generic integer value may be used as follows:
+
+- an integer constant;
+- a result of the evaluation of a get action.
+
+### **12.4 Generic ratio**
+
+A generic ratio value is a pair of integers (m, n) with m being the numerator and n the denominator of a fraction. If n is omitted, it is assumed to be 100, interpreting m as a percentage. n shall be greater than 1.
+
+A generic ratio value may be used as follows:
+
+- a ratio constant;
+- a result of the evaluation of a get action.
+
+## 12.5 Generic string
+
+A generic string value is a string of any number of characters. The design of this Recommendation does not limit the coding scheme of string values in any way. The values may be represented in any code sets. However, the coded representations may impose limitations. The ASN.1 syntax defined in this Recommendation supports only GraphicString.
+
+NOTE 1 – It is recommended that the authors assume this limitation.
+
+GraphicString contains all G sets + SPACE as defined in ASN.1. Such specification allows for international string.
+
+The string is considered as a whole, i.e. the component characters cannot be addressed individually.
+
+NOTE 2 – Typically, the character string is used as a label, e.g. “Help”.
+
+The generic string value may be specified as follows:
+
+- a string constant;
+- a result of the evaluation of a get action.
+
+There is a difference between the lowercase and uppercase character.
+
+## 12.6 Generic reference
+
+A generic reference is one of the references defined by this Recommendation (see Generic reference mechanism).
+
+A generic reference value may be specified as follows:
+
+- a reference constant;
+- a result of the evaluation of a get action.
+
+## 12.7 Generic list
+
+A generic list value is an ordered set, possibly empty, of generic values of any type. Each element of a generic list value may have a distinct type from the other elements of the list. Each element of a generic list is implicitly indexed.
+
+NOTES
+
+1 – An element of a list may be another generic list.
+
+2 – Each element, within a list or a sublist, may be retrieved separately using the Get Data action facility.
+
+3 – The generic list type may be used to construct vectors (same type for all elements of the list) and compound sets (sets of elements of various types).
+
+A generic list value may be specified as follows:
+
+- a list of constants;
+- a result of the evaluation of a get action.
+
+## 13 Macro Mechanism
+
+The macro mechanism provides a general technique for producing efficient coding of frequently used action and link objects in which only a few values are changed from one to another. This allows the sharing and reuse of complex behaviours. An author may create a catalogue of predefined action and link object templates, that are also called macro action object (see 18.4) and macro link object (see 19.5). In a macro action object or a macro link object, at least one attribute is encoded as a macro parameter value.
+
+A macro parameter value is composed of:
+
+- A Macro Def ID: It is either a string or an integer. It is used as a symbol representing the macro parameter. A given Macro Def ID may be used by many macro parameter values.
+- A Default usage value: It is a value to be assigned to the attribute encoded as a macro parameter value when the macro usage value assignment is omitted.
+
+Each link object contains an optional set of attributes called “macro parameter resolution” and which is used to resolve the macro parameter value contained in its link effect. Each macro parameter resolution is composed of a Macro Def ID and the corresponding macro usage value to be assigned to the Macro Def ID.
+
+When a link object is fired, the link effect is to be processed. The first step of this process is called the macro resolution phase and is limited to this link effect process.
+
+NOTE 1 – As the same link may be fired several times in parallel, therefore, the macro resolution phase is limited to a given link effect process.
+
+The aim of this phase is to assign a macro usage value to each macro parameter value contained in the link effect. Each macro parameter resolution is propagated to the action object describing the link effect. The following applies:
+
+- if this action is a nested action object, the macro parameter resolution is also propagated to the embedded action object;
+- if an embedded link object is activated from this link effect, the macro parameter resolution is propagated to this embedded link object except if this embedded link object itself contains a macro parameter resolution which uses the same Macro Def ID.
+
+During the propagation phase, for each macro parameter value, the following applies:
+
+- The Macro Def ID of the macro parameter value is retrieved from one of the propagated macro parameter resolution: This macro parameter value is replaced by the corresponding macro usage value of this propagated macro parameter resolution.
+- NOTE 2 – Even if the usage value is not compatible with the expected type of the attribute encoded as macro parameter value, the MHEG engine is required to assign it. It is for the object designer to ensure the compatibility.
+- NOTE 3 – If the usage value is an evaluated value, the macro parameter value is replaced by this Get action without processing it.
+- Otherwise, this macro parameter value is replaced by the corresponding default usage value encoded within this macro parameter value. If no default usage value is provided, this macro parameter value is replaced by the value “undefined”.
+
+These abbreviations are used for the following examples:
+
+- MPR      Macro Parameter Resolution
+- MD I     Macro Def ID
+- MUV     Macro Usage Value
+- DUV     Default Usage Value (when DUV is omitted, no default usage value is provided).
+- ALE      Action in Link Effect
+
+**Example 1 – Simple link effect.**
+
+L1 has following specifications:
+
+- LC1: Button1 becomes selected.
+- MPR1: (MDI = TARGET1, MUV = 700:1), (MDI = TARGET2, MUV = 700:2).
+- ALE1: New(MDI = TARGET1), New(MDI = TARGET2), Run(MDI = TARGET1), Run(MDI = TARGET2).
+
+If LC1 is satisfied, the macro resolution phase is processed and ALE1 is processed as follows:
+
+- ALE1: New(700:1), New(700:2), Run(700:1), Run(700:2).
+
+**Example 2 – Embedded action within link effect.**
+
+L2 has following specifications:
+
+- LC2: Button1 becomes selected.
+- MPR2: (MDI = SYNC, MUV = serial), (MDI = TARGET1, MUV = 700:1), (MDI = TARGET2, MUV = 700:2).
+- ALE2:    ActionObject1.
+
+And ActionObject1 is as follows:
+
+- Synchro indicator: SYNC.
+- Action set: New(TARGET1), Run(TARGET1), Stop(TARGET2).
+
+If LC2 is satisfied, the macro resolution phase is processed and each MUV is propagated to ActionObject1, and ActionObject1 is processed as follows:
+
+- Synchro indicator: Serial.
+- Action set: New(700:1), Run(700:1), Stop(700:2).
+
+If synchro indicator is resolved as “undefined”, the action is not processed.
+
+**Example 3** – Embedded links within link effect.
+
+L3 has following specifications:
+
+- LC3: Button1 becomes selected..
+- MPR3: (MDI = TARGET1, MUV = 700:1).
+- ALE3: New(TARGET1), Activate(L10), Activate(L20).
+
+L10 is as follows:
+
+- LC10: If TARGET1 is “not running”.
+- MPR10: None.
+- LE10: Run(TARGET1).
+
+And L20 is as follows:
+
+- LC20: If TARGET1 is “not running”.
+- MPR20: (MDI = TARGET1, MUV = 999:1).
+- ALE20: New(TARGET1), Run(TARGET1).
+
+If LC3 is satisfied, MPR3 is propagated to ALE3, L10 and L20. And L10 is processed as follows:
+
+- LC10: If 700:1 is “not running”.
+- LE10: Run(700:1).
+
+However, L20 is processed as follows:
+
+- LC20: If 700:1 is “not running”.
+- ALE20: New(999:1), Run(999:1).
+
+## 14 Hooks
+
+This clause describes the support for the handling of hooks, which are used in content, script and descriptor objects. Hooks provide the information for the type identification of the encoded data. A hook consists of the encoding information that identifies the encoding method and an optional encoding description that may be used for specifying parameters of the encoding method.
+
+Two kinds of hooks are provided, one for the content data and another for the script data:
+
+- 1) **Content hook:** Composed of an identification field for the data encoding standard and a descriptive field:
+  - a) The content encoding information contains an identification of the content encoding standard. A wide range of existing encoding standards such as MPEG, G711 or JPEG are maintained in the registered catalogue via the procedure described in ISO/IEC 13522-4. Private encoding formats can also be provided using a proprietary catalogue.
+  - b) The content encoding description gives a more precise description of the characteristics needed to decode the content. The semantics of these parameters are not defined by MHEG but are given by the semantics of the data encoding Standard or Recommendation with respect to the using application. Such information may also be provided within the content encoding catalogues.
+
+- 2) **Script hook:** Composed of an identification field for scripting language and a descriptive field:
+  - a) Scripting encoding information contains an identification of the script encoding standard. A wide range of existing encoding standards such as C, C++ or Lisp are maintained in the registered catalogue via the procedure described in ISO/IEC 13522-4. Private encoding formats can also be provided using a proprietary catalogue.
+  - b) Scripting language description gives a more precise description of the characteristics needed to decode the script. The semantics of these parameters are not defined by MHEG but are given by the semantics of the data encoding Standard or Recommendation with respect to the using application. Such information may also be provided within the script encoding catalogues.
+
+## 15 Extensibility
+
+Following extensibility is provided by this Recommendation:
+
+- 1) Catalogues (see 15.1);
+- 2) Addition of new MHEG object classes (see 15.2);
+- 3) Extensibility Provision (see 15.3).
+
+### 15.1 Catalogues
+
+ISO/IEC 13522-1 provides a set of catalogues to maintain compatibility between MHEG engines and to allow extensibility. New concepts can be made available to all MHEG systems if you register a reference to a format identifier in a registered catalogue or only to one group of applications if you register it in a proprietary catalogue:
+
+- 1) The registered catalogues are maintained in accordance with ISO/IEC 13522-4. Standardised, well-known concepts are listed in the registered catalogue. It is possible to register upcoming concepts in this catalogue.
+- 2) Application-specific concepts reside in the proprietary catalogue, which is private to only one set of applications. These catalogues can only be referenced by special MHEG engines. The maintenance of the proprietary catalogue is assured by the using application.
+
+Within each catalogue, an optional description may be associated with each entry to clarify the usage of it.
+
+An MHEG engine can take any catalogue entry into account, thereby, introducing the concept of this entry within its process. When an author provides an MHEG object or an action using such an entry, this MHEG engine will be able to process this object or this action. If the author uses an entry not taken into account by the MHEG engine, the MHEG object or the action will be ignored by this engine.
+
+For each of the following attributes used by this Recommendation, a registered catalogue is provided, and a using application may also maintain a proprietary catalogue for private use:
+
+- **Content encoding** contains a precise description of the content encoding methods that may be used in the content hook, e.g. ISO/IEC 11172-2 (MPEG2 video). A content encoding description may be associated with each entry of this catalogue.
+- **Content classification** is provided as an optional assistance in determining the type of content data. It provides information on the type of data. For media data it is used to indicate the perception media, e.g. text, graphics, audio. This information may be used in a negotiation process, a database, or by an MHEG engine to choose a decoder.
+- **Script encoding** contains the script languages that may be used in the script hook, e.g. C++, Smalltalk, SMSL. A script encoding description may be associated with each entry of this catalogue.
+- **Script classification** is provided as an optional assistance in determining the type of script language. This information may be used in a negotiation process, a database, or by an MHEG engine to choose a script decoder.
+- **Media type** contains the medium type that may be used in the descriptor object in order to help the mapping of a channel to a physical device, e.g. text, still image or video.
+
+- **Style** contains the styles that may be used in the set style action, e.g. for user interaction: button, slider, entry field. The styles may depend on the GUI on the platform and on user personalisation by the user. Additional information may be associated with each entry of this catalogue in order to define the style more precisely, e.g. a value range for a slider, an orientation for a menu.
+- **Event** contains a list of catalogued event identifiers (e.g. mouse click, keyboard key pressed, remote control command) that may be used in the descriptor object to indicate the expected mapping of event identifiers provided by the author to the catalogued event identifiers. Additional information may be associated with each entry of this catalogue in order to define the event more precisely, e.g. the position of the click.
+- **Extended elementary action** contains a list of catalogued elementary actions used in the “catalogued elementary action” action. These catalogued elementary actions are used to extend the number of elementary actions defined by this Recommendation, e.g. draw a line, arithmetic operation. Additional information may be associated with each entry of this catalogue in order to define the behaviour of an action more precisely, e.g. the parameters, the MHEG effect, the allowed periods, additional error conditions.
+- **Extended attribute** contains a list of catalogued attributes used in the set catalogued attribute action. These catalogued attributes are used to extend the number of attributes of MHEG entities defined in this Recommendation, e.g. colour, text fonts. Additional information may be associated with each entry of this catalogue in order to define the attribute more precisely, e.g. the type.
+
+## 15.2 Addition of New MHEG object classes
+
+This Recommendation reserves numbers 0 to 9999 of ASN.1 OBJECT IDENTIFIER arc3. The numbers from 0 to 9999 shall not be used privately. However, a using application may use other numbers to create new object classes, that may be complete new object classes or modifications of certain existing object classes.
+
+## 15.3 Extensibility Provision
+
+In order to enable future extension of attributes, “Extensibility Provision” encoded as “...” in ASN.1 is provided. “Extensibility Provision” is added to the following places in ASN.1:
+
+- “elementary action” attribute;
+- “evaluated value” attribute;
+- “description” attribute of MH-object class;
+- each leaf class of MHEG object.
+
+And for each “Extensibility Provision” attribute, a list of tags numbered from 0 to 9999 is reserved in order to be used in other Recommendations of the T.170 series. Reserved tags shall not be used privately.
+
+# SECTION 3 – OVERVIEW OF MHEG CLASSES
+
+The following clauses present the structure provided by MHEG to interchange multimedia and hypermedia information. The MHEG engine parses this structure.
+
+## 16 MHEG object classes overview
+
+The object-oriented approach was chosen for the design of the standard because it fits the requirements of active, autonomous and reusable objects. The interchanged object classes have been classified as shown in Figure 21. Each interchanged object belongs to one of the **emphasised** classes. Abstract classes have been added to describe common attributes or to group classes dealing with similar topics. MHEG does not define methods on its classes. Thus, use of the object-oriented paradigm is limited to attribute inheritance.
+
+In Figure 21, the greater-than sign ( > ) means “has the following subclasses”. Only the instances of classes that have been emphasised may be interchanged. The useful definitions are not considered to be a separate class. They are merely a convenient grouping of utility attributes.
+
+![MHEG inheritance tree diagram showing the hierarchy from MH-OBJECT to various subclasses like ACTION, LINK, MODEL, SCRIPT, COMPONENT, CONTENT, MULTIPLEXED CONTENT, COMPOSITE, CONTAINER, and DESCRIPTOR.](4801e73fa692059f2ca78196e6e907be_img.jpg)
+
+```
+
+graph TD
+    MH-OBJECT > ACTION
+    MH-OBJECT > LINK
+    MH-OBJECT > MODEL
+    MH-OBJECT > CONTAINER
+    MH-OBJECT > DESCRIPTOR
+    MODEL > SCRIPT
+    MODEL > COMPONENT
+    COMPONENT > CONTENT
+    COMPONENT > COMPOSITE
+    CONTENT > MULTIPLEXED_CONTENT[MULTIPLEXED CONTENT]
+  
+```
+
+MHEG inheritance tree diagram showing the hierarchy from MH-OBJECT to various subclasses like ACTION, LINK, MODEL, SCRIPT, COMPONENT, CONTENT, MULTIPLEXED CONTENT, COMPOSITE, CONTAINER, and DESCRIPTOR.
+
+Figure 21/T.171 – MHEG inheritance tree
+
+## 17 Structure of MH-Object Class
+
+This clause describes the common structure provided for interchanging all the instances of MHEG classes, the MHEG objects, defined by this Recommendation. This mechanism provides a consistent approach to the identification and interchange of MHEG objects.
+
+The MH-Object class provides the following information for the identification of MHEG objects.
+
+### 17.1 Class identification
+
+The class identification is composed of the identification of the standard, the standard version and a specific identifier unique for each MHEG object class. The class identification attribute is encoded at level C using the ASN.1 technique of OBJECT IDENTIFIER (see 8.2.3.1). For the ease of encoding, this attribute is not encoded within MH-object class at level C. This attribute is encoded individually for each interchanged class in order to assign a unique number for each class instead of inherited directly from MH-object class.
+
+### 17.2 MHEG-ID
+
+An MHEG-ID may be provided to uniquely identify an interchanged object within the scope of an application.
+
+### 17.3 General object information
+
+MH-object class also gives supplementary information for an MHEG object as follows:
+
+- 1) Name of the MHEG object.
+- 2) Owner of the MHEG object.
+- 3) Version of the MHEG object.
+- 4) Last modification date of the MHEG object.
+- 5) List of keywords qualifying the MHEG object.
+- 6) Readable copyright information relative to the MHEG object.
+- 7) Copyright identifier used by certain authorised organisation to identify the copyright work type of the MHEG object. For example:
+  - a) ISBN (International Standard Book Number) for book;
+  - b) ISSN (International Standard Serial Number) for periodical publications;
+  - c) ISRC (International Standard Record Code) for sound recording;
+  - d) ISAN (International Standard for Audiovisual Number) for audiovisual application.
+
+- 8) Copyright number used by certain authorised organisation to uniquely identify the copyright information assigned to the MHEG object within a copyright identifier scope, e.g. 2-11072557-5 is an ISBN copyright number.
+- 9) Readable licence information relative to the usage of the MHEG object.
+- 10) Cache priority, which may be used by the MHEG engine as a hint of how to manage the MHEG objects. This is an integer in the range from 0 to 255. The value 0 means that the MHEG engine should delete the object from its memory space entirely if it receives a Destroy action. The value 255 means that the MHEG engine is strongly encouraged to cache the MHEG object within its memory space at the time of a Destroy action. Other values may be interpreted by each MHEG engine independently taking into account the range. However, the MHEG engine is not obliged to follow this instruction. This is only provided as a hint information for the MHEG engine.
+- 11) Readable comments relative to the MHEG object.
+- 12) Extensibility provision used by other standards which describes an extension of this Recommendation.
+
+## 18 Structure of Action Class
+
+The action class defines a reusable arrangement of elementary actions. Action objects that are instances of the action class are used in link objects in order to describe their link effects. A given action object may be addressed by many link objects. Several link conditions in different links may be satisfied at the same instant and are assumed to be fired and processed in parallel. Therefore, the processing of actions describing the link effect has a local effect limited to the link itself.
+
+The MHEG action class consists of following information:
+
+- 1) A synchro indicator specifies the type of processing of the synchronised actions. Two values are defined: “parallel” and “serial”. When it is set to “serial”, all the actions within the “synchronised action set” are processed in serial. When it is set to parallel, all these actions are processed in parallel (see 31.3). Since synchronised actions may be processed in parallel, it is the author’s responsibility to take into account any side effects due to the parallelism. Specification of contradictory actions is deprecated.
+
+### NOTES
+
+1 – An action object that calls for a parallel Run and stop of an rt-content is ambiguous since the final state is not defined.
+
+2 – An action object that calls in the same serial group for an rt-content to run and stop after a delay of one second is not ambiguous. The rt-content is to be presented for one second.
+
+3 – An MHEG engine is not required to perform true parallel processing, but authors must organise the group as if they were to be processed in parallel.
+
+- 2) A synchronised action set is a set of elementary actions and/or other embedded action objects.
+
+Using this structure, an author is able to describe the following action objects:
+
+- Basic action object (see 18.2);
+- Nested action object (see 18.3);
+- Macro action object (see 18.4).
+
+### 18.1 Elementary actions
+
+This Recommendation defines a list of elementary actions that may be included in an action object to modify the behaviour of MHEG entities (see Section 4, “MHEG entities common behaviour”), e.g. Prepare, Run. The structure of each elementary action is as follows:
+
+- 1) A target set is defined as a list of generic references or only one generic reference. Each elementary action is to be processed on the specified target set. If more than one target is specified in the target set, whatever the value of the synchro indicator is, the elementary action is processed in parallel on all the targets specified in the target set. Authors should assume that the MHEG engine applies the elementary action to the multiple targets in parallel.
+
+A common target set can be specified for several elementary actions by using the alias mechanism (see 10.3) or macro parameter mechanism (see clause 13).
+
+- 2) An optional transition duration may be provided for some elementary actions. A transition duration is expressed in GTU. When a transition duration is specified, the corresponding elementary action is to be processed during this transition duration. When no transition duration is specified, a null duration is taken into account.
+- 3) The specific action parameters are defined for each elementary action (see Sections 4, 5, 6, 7 and 8).
+
+## 18.2 Basic action object
+
+A basic action object contains only elementary actions. It does not contain macro parameters or embedded action objects within its synchronised action set.
+
+NOTE – The using application is responsible for determining the appropriate number of elementary actions.
+
+In Figure 22, the MHEG engine completes the parallel processing of the MHEG effect of elementary action 1 on targets T1, T2 and T3. When completed, the MHEG effect of elementary action 2 is processed on T4.
+
+![Diagram of a basic action object structure. A rectangular box is divided into two sections. The top section is labeled 'Synchro indicator:serial'. The bottom section is labeled 'Synchronised action set' and contains a bulleted list: '- Elementary action 1 (Targets T1, T2, T3)' and '- Elementary action 2 (Target T4)'.](57939c16065211317c5442cf2a4009e0_img.jpg)
+
+```
+
+    graph TD
+      subgraph Box [ ]
+        direction TB
+        A["Synchro indicator:serial"]
+        B["Synchronised action set"]
+        B --- C["- Elementary action 1 (Targets T1, T2, T3)"]
+        B --- D["- Elementary action 2 (Target T4)"]
+      end
+  
+```
+
+Diagram of a basic action object structure. A rectangular box is divided into two sections. The top section is labeled 'Synchro indicator:serial'. The bottom section is labeled 'Synchronised action set' and contains a bulleted list: '- Elementary action 1 (Targets T1, T2, T3)' and '- Elementary action 2 (Target T4)'.
+
+T0825680-96/d021
+
+**Figure 22/T.171 – Example of a basic action object**
+
+## 18.3 Nested action object
+
+In order to describe more complex behaviour, an embedded action object may be contained in the synchronised action set. The embedded action object can be itself a nested action object. A complete hierarchy of action objects can be designed using this mechanism.
+
+NOTE – The using application is responsible for determining the appropriate depth of nesting.
+
+In the example of Figure 23, the MHEG engine processes the MHEG effect of elementary action 1 on target T. When completed, the MHEG engine processes, in parallel, the MHEG effect of elementary action A on target S and the MHEG effect of elementary action B on target R. When completed, the MHEG effect of elementary action 2 is processed on target R.
+
+## 18.4 Macro action object
+
+In order to produce efficient coding of frequently used action objects in which only a few values change from one link to another, the synchro indicator attribute of an action object and each parameter of an elementary action may be specified as a macro parameter value. A macro action object contains at least one macro parameter value. Each macro parameter value is resolved when the link object which uses this action is fired (see 19.3 for more details).
+
+# 19 Structure of Link Class
+
+An MHEG link class is defined for specifying spatial, temporal and conditional relations between, and actions upon, MHEG entities. The link contains a condition, which when satisfied evaluates to true or provokes the processing of actions on targets that produce the required effect. The link is said to be fired.
+
+![Diagram of a nested action object structure. The outer container has a 'Synchro indicator: serial' at the top, followed by a 'Synchronised action set' section. Inside this set are 'Elementary action 1 (Target T)' and 'Elementary action 2 (Target R)'. An 'Action object "embedded"' is nested within 'Elementary action 1'. This embedded object has a 'Synchro indicator: parallel' and a 'Synchronised actions' section containing 'Elementary action A (Target S)' and 'Elementary action B (Target R)'.](3bf1696c3034743b5ab07a0b5e398347_img.jpg)
+
+```
+
+graph TD
+    subgraph OuterBox [ ]
+        direction TB
+        S1[Synchro indicator: serial]
+        subgraph SynchronisedActionSet [Synchronised action set]
+            direction TB
+            EA1[Elementary action 1 (Target T)]
+            subgraph EmbeddedBox [Action object "embedded"]
+                direction TB
+                S2[Synchro indicator: parallel]
+                subgraph SynchronisedActions [Synchronised actions]
+                    direction TB
+                    EA2A[Elementary action A (Target S)]
+                    EA2B[Elementary action B (Target R)]
+                end
+            end
+            EA2[Elementary action 2 (Target R)]
+        end
+    end
+
+```
+
+T0825690-96/d022
+
+Diagram of a nested action object structure. The outer container has a 'Synchro indicator: serial' at the top, followed by a 'Synchronised action set' section. Inside this set are 'Elementary action 1 (Target T)' and 'Elementary action 2 (Target R)'. An 'Action object "embedded"' is nested within 'Elementary action 1'. This embedded object has a 'Synchro indicator: parallel' and a 'Synchronised actions' section containing 'Elementary action A (Target S)' and 'Elementary action B (Target R)'.
+
+**Figure 23/T.171 – Example of a nested action object**
+
+Only those link objects that have been activated can be firable (see 29.2). Several link conditions in different links may be satisfied at the same instant and are assumed to be fired and processed in parallel by the MHEG engine.
+
+The link object is separated from the objects that produce the triggering contexts. The basic behaviour of each MHEG entity (e.g. volume, channel on/off) is part of the entity itself. During the life of the entities, change in the behaviour can be used to trigger a separate link object that calls for the actions to be processed. These actions, in turn, modify the basic behaviour of any other MHEG entity, for example, to increase a volume. This may in turn generate further changes in behaviour and trigger further links.
+
+Each instance of a link class contains a link condition and a link effect.
+
+Using this structure, an author is able to describe the following types of link objects:
+
+- Basic link object (see 19.3);
+- Nested link object (see 19.4);
+- Macro link object (see 19.5).
+
+## 19.1 Link condition
+
+The link condition is defined as either a trigger condition (see 19.1.1) or a logical combination of trigger and constraint conditions (see 0).
+
+The link condition is evaluated as follows:
+
+- 1) When a link object becomes active, the link condition is evaluated to false.
+- 2) If the link condition is a single trigger condition, the link condition evaluates the value of the trigger condition. If the link condition is a logical combination of conditions, the link condition evaluates the value of the top node of the logical tree combining the conditions (see Figure 25).
+- 3) If the link condition is evaluated to true, the link is fired, i.e. its link effect is processed by the MHEG engine (see 31.2). If the link condition is evaluated to false or “undefined”, the link is not fired, i.e. its link effect is not processed.
+
+A link may be fired several times during its activation, each time its link condition becomes true.
+
+![Diagram of Link object structure showing Link condition and Link effect components.](32d36dfe7dc75b7c63f8edf0f28e4009_img.jpg)
+
+**Link object**
+
+The diagram illustrates the structure of a Link object, which is divided into two main sections: **Link condition** and **Link effect**.
+
+**Link condition** is further divided into two options, separated by the word "or":
+
+- Single trigger condition**: A box representing a single condition.
+- Logical combinations of conditions**: A tree structure where:
+  - Black circles represent **Logical operators**.
+  - Rectangles represent **Trigger condition** or **Constraint condition**.
+  - Lines connect operators to their respective conditions.
+
+**Link effect** contains two boxes:
+
+- Resolution of macros (optional)**: A box for macro resolution.
+- Action object (simple, nested or macro action)**: A box for the action to be performed.
+
+T0825700-96/023
+
+Diagram of Link object structure showing Link condition and Link effect components.
+
+**Figure 24/T.171 – Link object structure**
+
+![Two examples of logical trees describing combinations of conditions.](66e89867f97592fd4bfab0e4f2b2054f_img.jpg)
+
+The diagram shows two examples of logical trees:
+
+**Example 1 (Top):**
+
+- Root node: **AND** (true)
+  - Left child: **OR** (true)
+    - Left child: **Trigger A** (true)
+    - Right child: **Trigger B** (false)
+  - Right child: **AND** (true)
+    - Left child: **Constraint C** (true)
+    - Right child: **XOR** (true)
+      - Left child: **Constraints D** (false)
+      - Right child: **Constraints E** (true)
+      - Right child: **Constraints F** (false)
+
+**Example 2 (Bottom):**
+
+- Root node: **OR** (false)
+  - Left child: **AND** (false)
+    - Left child: **Trigger G** (false)
+    - Right child: **Constraint H** (true)
+  - Right child: **NOT** (false)
+    - Child: **AND** (true)
+      - Left child: **Trigger I** (true)
+      - Right child: **Constraint J** (true)
+
+Two examples of logical trees describing combinations of conditions.
+
+T0825710-96/d024
+
+**Figure 25/T.171 – Examples of logical tree describing a logical combination of conditions**
+
+### 19.1.1 Trigger condition
+
+A trigger condition describes the occurrence of a change in MHEG entities' behaviour triggering the link. The trigger is described as a change of attribute or status value of an MHEG entity. The following behaviour changes are triggerable:
+
+- 1) Temporal changes: Provoked by timestones or delay.
+- 2) Action changes: Consequences of any elementary action.
+- 3) Interaction changes: Occur, for example, when the user selects a menu or clicks on a button.
+- 4) Any catalogued event changes: Occur, for example, when a system event happens.
+
+The trigger condition is expressed as a transition, i.e. as a double condition on the same source. It is composed of the following:
+
+- a source value;
+- a previous condition, which expresses the condition to be satisfied before the transition occurs;
+- a current condition, which expresses the expected condition to satisfy after the transition occurs.
+
+A trigger condition evaluates a boolean value or “undefined”. The following applies:
+
+- 1) When a link object becomes active, each trigger condition is evaluated to false.
+- 2) Evaluates the previous condition of each trigger condition.
+- 3) The source value of each trigger condition is an evaluated value on a target attribute or a status, e.g. get preparation status (target). When the value of this attribute or status changes, the following steps are applied for the corresponding trigger condition:
+  - a) assigns this value to the current comparison value and evaluates the current condition;
+  - b) evaluates the trigger condition by processing the following logical operation: “previous condition” AND “current condition”:
+    - i) if the result is true and if the link condition is defined as a single trigger condition, the link condition is evaluated to true;
+    - ii) if the result is true and if this trigger condition is part of a logical combination of conditions, this logical combination of conditions is to be evaluated (see 19.1.8).
+  - c) Evaluates the trigger condition to false.
+  - d) Go to 2.
+
+NOTE – Steps 3) a) and 3) d) should be considered as an atomic operation for link, i.e. if a value tested by a trigger condition changes when the MHEG engine is processing steps 3) a) to 3) d), the processing of such a change is delayed until the current processing enters in step 3).
+
+Table 1 shows some examples of trigger conditions. In the example, Get CV (rt-content N) means Get CV action targeted to the rt-content N in order to retrieve the current audible volume (CV), Get Event (rt-content N) means Get Event action targeted to the rt-content N in order to retrieve the number of most recently happened event, and Get Data (content A) means Get Data action targeted to the content object A in order to retrieve the contained generic value contained.
+
+**Table 1/T.171 — Examples of trigger conditions**
+
+| Trigger source value        | Previous condition                                                              |                          | Current condition |                          | Semantics                                                                                                                                                                                                                                                                                                                  | Nature of the Change                                                                                                                                                                                                                                                                             |
+|-----------------------------|---------------------------------------------------------------------------------|--------------------------|-------------------|--------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+|                             | Operator                                                                        | Previous value           | Operator          | Current value            |                                                                                                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                                                  |
+| Get CV<br>(rt-content N)    | ==                                                                              | 10                       | <                 | 5                        | rt-content N had CV equal to 10, and decreases to less than five.                                                                                                                                                                                                                                                          | Change from a specified previous value to a specified current value.                                                                                                                                                                                                                             |
+| Get CV<br>(rt-content N)    | ==                                                                              | Get Data<br>(content A)  | <                 | Get Data<br>(content B)  | rt-content N had CV equal to the value specified in the data of content object A, and changes to a value less than that of the value in content object B.                                                                                                                                                                  |                                                                                                                                                                                                                                                                                                  |
+| Get CV<br>(rt-content N)    | Any                                                                             | “unspecified”            | Any               | “unspecified”            | The CV of rt-content N has changed. The value is not significant.                                                                                                                                                                                                                                                          | Change from an "unspecified" value to an "unspecified" value. The trigger is on a change of the source value without regard for its previous and current values.                                                                                                                                 |
+| Get CV<br>(rt-content N)    | ==                                                                              | 10                       | Any               | “unspecified”            | The CV of rt-content N was 10 and has changed. The new value is not significant.                                                                                                                                                                                                                                           | Change from a specified value to an "unspecified" value. The trigger is on a change of the source value without regard for its current value.                                                                                                                                                    |
+| Get CV<br>(rt-content N)    | Any                                                                             | “unspecified”            | >                 | 10                       | The CV of rt-content N becomes greater than 10. The previous value is not significant. Note that the previous value may have been greater than 10.                                                                                                                                                                         | Change from any previous value to a specified current value range.                                                                                                                                                                                                                               |
+| Get CV<br>(rt-content N)    | Any                                                                             | “unspecified”            | ==                | 10                       | The CV of rt-content N becomes equal to 10. The previous value is not significant. Note that the previous value may have been equal to 10.                                                                                                                                                                                 | Change from an "unspecified" value to a specified current value. The trigger is on a change of the source value whatever its previous value.                                                                                                                                                     |
+| Get CV<br>(rt-content N)    | <                                                                               | Get CV<br>(rt-content P) | >                 | Get CV<br>(rt-content P) | The CV of rt-content N was less than the CV of rt-content P and has become greater.                                                                                                                                                                                                                                        | Change with respect to other rt-contents.                                                                                                                                                                                                                                                        |
+| Get Event<br>(rt-content N) | Any                                                                             | “unspecified”            | ==                | 10                       | The event 10 has occurred on rt-content N. The previous event value is not significant.                                                                                                                                                                                                                                    | Becomes true any rising of the event 10.                                                                                                                                                                                                                                                         |
+| Get Event<br>(rt-content N) | ==                                                                              | 10                       | ==                | 10                       | The previous event occurred to rt-content N was 10. The same event occurs again.                                                                                                                                                                                                                                           | Becomes true for each successive rising of the event 10.                                                                                                                                                                                                                                         |
+| Get CV<br>(rt-content N)    | Previous condition is omitted, i.e. it is the negation of the current condition |                          | >=                | 5                        | The CV of rt-content N was less than 5 and increases greater than or equal to 5. The previous condition is interpreted as $CV < 5$ . The previous value range is $(-\infty, 4)$ , the current value range is $[5, +\infty)$ . These two value ranges do not overlap and their union is the whole range of integer numbers. | Change from a previous value range to a current value range where the two value ranges do not overlap and where the union of the value ranges is the largest possible value range. In that case, the previous condition is omitted, and so interpreted as the negation of the current condition. |
+
+### 19.1.2 Constraint condition
+
+A constraint condition may be provided within a logical combination of conditions. It expresses a required contextual state at the moment when one of the trigger conditions is satisfied. A constraint condition makes it possible to specify more precisely the context in which the link condition will be satisfied.
+
+A constraint condition is composed of a source value and a current condition which expresses the expected condition to satisfy.
+
+NOTE – Constraints do not require a previous condition because they express contextual states at the moment when the trigger is satisfied.
+
+A constraint condition evaluates a boolean value or “undefined”. It is satisfied when the specified current condition is satisfied for the source value. The constraint conditions are to be evaluated at the instant when one of the trigger conditions becomes true.
+
+Table 2 shows some examples of constraint conditions.
+
+**Table 2/T.171 – Examples of constraint conditions**
+
+| Source Value          | Current condition |                      | Semantics                                                                  |
+|-----------------------|-------------------|----------------------|----------------------------------------------------------------------------|
+|                       | Operator          | Current Value        |                                                                            |
+| Get CV (rt-content N) | <                 | 5                    | rt-content N has CV value less than five.                                  |
+| Get CV (rt-content N) | <                 | Get Data (content A) | rt-content N has CV value less than that of the value in content object A. |
+| Get CV (rt-content N) | ==                | 5                    | rt-content N has CV value equal to five.                                   |
+
+### 19.1.3 Source value
+
+The source value is a value used as the base of the comparison described in the previous condition and the current condition. The presence of the source value in the condition is mandatory.
+
+The source value is always provided by an evaluated value, i.e. it is expressed as a result of a get action.
+
+### 19.1.4 Comparison value
+
+The comparison value is a value that is to be compared to the source value using the comparison operator in the previous and the current conditions. The presence of the comparison value in the condition is mandatory.
+
+The comparison value is specified as one of the following:
+
+- 1) An evaluated value, i.e. it is expressed as a result of a get action.
+- 2) A constant value.
+- 3) One of the comparison value constants defined by this Recommendation, e.g. “ready”, “not ready” for the preparation status.
+- 4) “Unspecified” value to indicate that the value to be compared with the source is not important; what is important is that the value has changed. The following applies:
+  - a) Within a trigger condition:
+    - i) Within the previous condition: It means that the trigger condition is on a change of the source value whatever its previous value was.
+    - ii) Within the current condition: It means that it is a condition on a change of the source value whatever its current value becomes.
+
+- iii) Within both the previous and the current condition: It means that it is a condition on a change of value whatever its previous value was and whatever its current value becomes.
+
+The current value can be the same as the previous value, but the engine as wilfully set the same value to an attribute or a status. This is particularly useful for successive rising of the same event (see 6.3.7) or timestone (see 72.16.14), i.e. the same event may occur several times, each time the event identifier is set to the corresponding value.
+
+- b) Within a constraint condition: It means that the constraint condition is always evaluated to true.
+
+### 19.1.5 Previous condition
+
+The previous condition is used in trigger condition only. It is composed of a comparison operator and a previous comparison value.
+
+The previous comparison value is a generic value (see clause 11).
+
+When the previous condition is omitted, the previous condition is to be interpreted as the negation of the indicated current condition, and the following applies:
+
+- the comparison operator of the previous condition is the negation of the comparison operator of the current condition;
+- the comparison value of the previous condition is the same as the comparison value of the current condition.
+
+The previous condition is satisfied when the result of the comparison operation between the source value and the previous comparison value using the specified comparison operator is evaluated to true.
+
+### 19.1.6 Current condition
+
+The current condition is mandatory in a generic condition, and it is composed of a comparison operator and the current comparison value.
+
+The current comparison value is a generic value (see clause 11).
+
+The current condition is satisfied when the result of the comparison operation between the source value and the current comparison value using the specified comparison operator is evaluated to true.
+
+### 19.1.7 Comparison operator
+
+The comparison operator used in the previous and the current condition is one of the following:
+
+- == Comparison for equality;
+- != Comparison for inequality;
+- < Comparison for strict inferiority;
+- <= Comparison for inferiority or equality;
+- > Comparison for strict superiority;
+- >= Comparison for superiority or equality.
+
+NOTE 1 – A using application may provide other comparison operators.
+
+A comparison operation is a comparison between the source and a comparison value. The result of the comparison is as defined in Table 3.
+
+**Table 3/T.171 – Comparison operations**
+
+| <b>Comparison operator</b> | <b>Source Value (SV)</b>                                                                                                      | <b>Comparison Value (CV)</b>                                                                                                  | <b>Result Value (Boolean or “undefined”)</b> | <b>Remarks</b>                       |
+|----------------------------|-------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------|--------------------------------------|
+| ==                         | Generic boolean<br>Generic numeric<br>Generic integer<br>Generic ratio<br>Generic string<br>Generic reference<br>Generic list | Generic boolean<br>Generic numeric<br>Generic integer<br>Generic ratio<br>Generic string<br>Generic reference<br>Generic list | True: if SV == CV<br>False: otherwise        | See 1)<br>See 2)<br>See 3)<br>See 4) |
+| !=                         | Generic boolean<br>Generic numeric<br>Generic integer<br>Generic ratio<br>Generic string<br>Generic reference<br>Generic list | Generic boolean<br>Generic numeric<br>Generic integer<br>Generic ratio<br>Generic string<br>Generic reference<br>Generic list | True: if SV != CV<br>False: otherwise        | See 1)<br>See 2)<br>See 3)<br>See 4) |
+| <                          | Generic numeric<br>Generic integer<br>Generic ratio<br>Generic list of generic numeric /<br>generic integer / generic ratio   | Generic numeric<br>Generic integer<br>Generic ratio<br>Generic list of generic numeric /<br>generic integer / generic ratio   | True: if SV < CV<br>False: otherwise         | See 1)<br>See 4)                     |
+| <=                         | Generic numeric<br>Generic integer<br>Generic ratio<br>Generic list of generic numeric /<br>generic integer / generic ratio   | Generic numeric<br>Generic integer<br>Generic ratio<br>Generic list of generic numeric /<br>generic integer / generic ratio   | True: if SV <= CV<br>False: otherwise        | See 1)<br>See 4)                     |
+| >                          | Generic numeric<br>Generic integer<br>Generic ratio<br>Generic list of generic numeric /<br>generic integer / generic ratio   | Generic numeric<br>Generic integer<br>Generic ratio<br>Generic list of generic numeric /<br>generic integer / generic ratio   | True: if SV > CV<br>False: otherwise         | See 1)<br>See 4)                     |
+| >=                         | Generic numeric<br>Generic integer<br>Generic ratio<br>Generic list of generic numeric /<br>generic integer / generic ratio   | Generic numeric<br>Generic integer<br>Generic ratio<br>Generic list of generic numeric /<br>generic integer / generic ratio   | True: if SV >= CV<br>False: otherwise        | See 1)<br>See 4)                     |
+| Any                        | Any                                                                                                                           | CV type is not the same as SV type                                                                                            | False                                        | See 5)                               |
+| Any                        | Any SV type<br>“undefined”<br>“undefined”<br>“undefined”                                                                      | “undefined”<br>Any CV type<br>“unspecified”<br>“undefined”                                                                    | “undefined”                                  | See 6)                               |
+| Any                        | Any SV type                                                                                                                   | “unspecified”                                                                                                                 | True                                         | See 7)                               |
+
+This Recommendation does not define the semantics of operations on types of values different from those presented in Table 3. If such an operation is to be processed by the MHEG engine and if no semantics have been provided by the using application, this operation is evaluated to the value “undefined”.
+
+NOTE 2 – True > False and “Hello” <= “Bye!” are evaluated to “undefined”.
+
+In order to evaluate a result of some operations, the following applies:
+
+- 1) Two generic ratios shall be compared as follows:
+  - a) If the denominator is omitted, it is assumed as 100. For example: (10/100) == (10/omitted) is true.
+
+- b) A generic ratio is reduced if it is not irreducible. This reduction should be done only for comparison purposes. The value of the generic ratio still remains as it was before reduction. For example: (10/100) becomes (1/10) for comparison.
+  - c) A generic ratio is considered as a list containing two generic integer elements. So, the comparison between two lists applies (see below).
+- 2) The comparison between strings is made at the level of each character. The uppercase characters are distinguished from the lowercase characters.
+- NOTE 3 – It is similar to a comparison between two lists (see below). The strings need to have the same size, and each character needs to be identical.
+- NOTE 4 – Examples: Comparison of strings: “HELLO” == “HELLO” is true. “hello” == “HELLO” is false. “Hello” != “Hello” is false.
+- 3) The comparison of two references is made on the addressed entities. Two different references may address the same entity. In that case, the comparison for equality is evaluated to true. A comparison may be made between references addressing groups of entities. In that case, the comparison is made at the level of the addressed entities. The comparison for equality between two groups not having the same number of entities is evaluated to false. When the MHEG engine is unable to compare two references, the result of the comparison is evaluated to the value “undefined”.
+- NOTE 5 – This situation may occur when references are not yet resolved by the MHEG engine or when a reference addresses an unknown object.
+- NOTE 6 – For example: A content object has an MHEG-ID as 1000 and its external ID is “e:\mydir\content.mhg”. 1000 == “e:\mydir\content.mhg” is true. If an alias, e.g. ContentA, is assigned to this content, ContentA == 1000 is true, ContentA != “e:\mydir\content.mhg” is false.
+- 4) Two lists shall be compared as follows:
+- a) If the two lists have different lengths (i.e. not the same number of elements), the result of the comparison is evaluated to false.
+  - b) If the two lists have the same length (i.e. the same number of elements), the comparison is realised at the level of each element. Two elements in the same position of the two lists are compared using the comparison operator:
+    - i) If one of the comparisons at the level of elements is evaluated to false, the comparison at the level of the list is evaluated to false.
+    - ii) If one of the comparisons at the level of elements is evaluated to “undefined”, the comparison at the level of the list is evaluated to “undefined”.
+    - iii) Otherwise the comparison at the list level is evaluated to true. A logical AND operation is processed between the result of each compared elements.
+  - c) Two lists of length zero are considered to be strictly equal. For example: comparison of generic list of generic numeric: (2, 3, 5) == (2, 3) is false, (2, 3, 5) == (2, 3, 5) is true, (2, 3, 5) == (2, 4, 5) is false, (2, 3, 5) > (0, 1, 6) is false because 6 > 5, () <= () is true.
+- 5) The result of a comparison between non-compatible types is always evaluated to the value false. For example: comparison of non-compatible values: 3 != true is false, 5 != “a” is false.
+- 6) The comparison of two values is always gives the value “undefined” if one of the values is an “undefined” value. For example: (2, 3, 5) == (2, undefined, 5) is “undefined”, (2, 3, 5) > (0, 1, undefined) is “undefined”, “undefined” == “undefined” is “undefined”, “undefined” == “unspecified” is “undefined”.
+- 7) A given comparison value may be specified by the author as “unspecified” in the place of any comparison value. The comparison of a value with an “unspecified” value always gives true except if the value to be compared is “undefined”.
+- NOTE 7 – For example: (2, 5, 7) <= (2, unspecified, unspecified) is true, (2, 5, 7) >= (2, unspecified, unspecified) is true, “Hello” == unspecified is true, “undefined” <= “unspecified” is “undefined”.
+- NOTE 8 – Distinguish clearly between “undefined” and “unspecified” values. The value “undefined” is not provided by an author. It is always a result of a get action with an error or a result of a comparison operation containing a source value or a comparison value evaluated to “undefined”. The value “unspecified” is a wilful omission by the author.
+
+### 19.1.8 Logical combination
+
+A logical combination of conditions is defined as follows:
+
+- 1) A logical operator defines a logical operator to be applied to the list of conditions.
+- 2) A list of conditions. Each condition is either a trigger condition, a constraint condition, or another logical combination of conditions. It is a recursive structure. If the operator NOT is used, the list of conditions shall contain only one condition. If the other operators are used, the list of conditions shall contain at least two conditions.
+
+A logical combination of conditions has the form of a logical tree. The leaves of the logical tree are trigger or constraint conditions. A logical operator is attached to each node.
+
+The two trees described in Figure 25 show different combinations of conditions. Any other types of combinations may be provided. Some combinations are meaningless, for example OR (Trigger Condition K, Trigger Condition L, Constraint Condition M). In that case, the constraint condition is useless.
+
+The evaluation of the logical combination of conditions is as follows:
+
+- 1) Each trigger condition is evaluated as specified in 19.1.1.
+- 2) Each time one of the trigger conditions becomes true, the following applies:
+  - a) each constraint condition is evaluated as specified in 0;
+  - b) then each node is evaluated as follows in a bottom up manner:
+    - i) the logical operator attached to the node is applied on the evaluated conditions attached to this node, as specified in 19.1.9;
+    - ii) each node evaluates the result of the previous logical operation, i.e. a boolean value or “undefined”.
+- 3) The link condition evaluates the value of the top node, i.e. the logical tree’s root in Figure 25.
+
+### 19.1.9 Logical operator
+
+The logical operator is used within a logical operation. The following logical operators are defined:
+
+- 1) AND: logical and;
+- 2) OR: logical or;
+- 3) XOR: logical exclusive or;
+- 4) NOT: logical negation.
+
+A logical operation is composed of a logical operator and a list of operands. The result of the logical operation is evaluated as follows when the operator NOT is used:
+
+- 1) If the operator NOT is used with one operand, the result is as follows:
+
+|                    |            |             |
+|--------------------|------------|-------------|
+| a) NOT True        | evaluates: | False       |
+| b) NOT False       | evaluates: | True        |
+| c) NOT “undefined” | evaluates: | “undefined” |
+- 2) Otherwise the result is “undefined”.
+
+The result of the logical operation is evaluated as follows when operator NOT is used:
+
+- 1) If the operator AND, OR or XOR is used with n operands, n greater than 2, the logical operation is decomposed in n-1 operations, that are evaluated from left to right.
+
+For example: AND (c1, c2, c3, ..., cn-1, cn) is decomposed as  
+AND(...AND(AND(AND(c1, c2), c3), ...), cn)
+- 2) If the operator AND is used on two operands, the result is as follows:
+
+|                                |            |             |
+|--------------------------------|------------|-------------|
+| a) True AND True               | evaluates: | True        |
+| b) False AND False             | evaluates: | False       |
+| c) “undefined” AND “undefined” | evaluates: | “undefined” |
+| d) True AND False              | evaluates: | False       |
+| e) True AND “undefined”        | evaluates: | “undefined” |
+| f) False AND “undefined”       | evaluates: | “undefined” |
+
+- 3) If the operator OR is used on two operands, the result is as follows:
+  - a) True OR True evaluates: True
+  - b) False OR False evaluates: False
+  - c) “undefined” OR “undefined” evaluates: “undefined”
+  - d) True OR False evaluates: True
+  - e) True OR “undefined” evaluates: True
+  - f) False OR “undefined” evaluates: False
+- 4) If the operator XOR is used on two operands, the result is as follows:
+  - a) True XOR True evaluates: False
+  - b) False XOR False evaluates: False
+  - c) “undefined” XOR “undefined” evaluates: “undefined”
+  - d) True XOR False evaluates: True
+  - e) True XOR “undefined” evaluates: “undefined”
+  - f) False XOR “undefined” evaluates: “undefined”
+- 5) If the operator AND, OR or XOR is used on one operand, the result is “undefined”.
+
+## 19.2 Link Effect
+
+The link effect contains the following information:
+
+- 1) An optional macro resolution used to assign a usage value to each macro parameter. The macro resolution is defined as a list of macro parameter resolutions. Each macro parameter resolution is defined as:
+  - a) macro Def ID identifies one of the macro parameters;
+  - b) macro usage value specified as a generic value.
+- 2) An action, which may be a Basic action object (see 18.2), a nested action object (see 18.3) or a macro action object (see 18.4).
+
+The link effect is processed as specified in 31.2 when the link condition becomes satisfied, i.e. it becomes evaluated to true.
+
+## 19.3 Basic link object
+
+A basic link object is defined as a combination of a basic link condition and a basic link effect. The combinations that can be made can form a simple link object or a more complex one.
+
+A basic link condition does not contain any macro parameter. The following basic link conditions can be defined:
+
+- 1) TC;
+- 2) simple logical combination of conditions, e.g. TC AND CC, TC1 OR TC2;
+- 3) complex logical combination of TC and CC, e.g. NOT (((TC1 AND CC1) OR (TC2 AND NOT (CC3 AND CC4 AND CC5)) XOR (TC3 AND CC6)).
+
+A basic link effect does not contain any Activate actions (targeted to link objects). The following basic link effects can be defined:
+
+- 1) no macro parameter resolution and a basic action object;
+- 2) no macro parameter resolution and a nested action object;
+- 3) a set of macro parameter resolution and a macro action.
+
+## 19.4 Nested link object
+
+In order to describe more complex behaviour, a nested link object may be provided by an author. A nested link object contains an Activate elementary action within its link effect. The target of this Activate elementary action is called embedded link object. When the nested link object fires, the embedded link object is activated.
+
+The embedded link object can be itself a nested link object. A complete hierarchy of link objects can be designed using this mechanism.
+
+NOTE – For example, considering the link objects L1, L2 and L3 as follows:
+
+- L1 has LE1 as (run Image1, activate L2);
+- L2 has LE2 as (run Image2, activate L3);
+- L3 has LE3 as (run Content6).
+
+If the link condition of L1 is satisfied, presentation of Image1 begins and embedded L2 is activated each time due to the LE1. If the link condition of L2 is satisfied after this activation of L2, presentation of Image2 begins and embedded L3 is activated due to the LE2. And so on.
+
+The links L2 and L3 are called embedded links from the L1 point of view. The link L3 is called embedded link from the L2 point of view.
+
+## 19.5 Macro link object
+
+In order to produce efficient coding of frequently used link objects in which only a few values change from one link condition to another, a macro link object is an embedded link object which contains at least one macro parameter value within its link condition. Each macro parameter value is resolved when it is activated from a nested link object (see 6.3.13).
+
+NOTE – The macro link object needs to be an embedded link object, otherwise the macro parameter value will never be resolved, so the link condition described will never be satisfied.
+
+## 20 Structure of Model Class
+
+The model objects, instance of model classes, may be interchanged within or across using applications. A model object is considered as a template object. From this model, rt-objects may be created based on instructions given by the author.
+
+The model class is an abstract class inherited by script class and component class.
+
+Any number of rt-objects may be created from a given model object. The activation of an rt-object does not affect the model object. This allows the reuse of the same model object in different contexts, i.e. different rt-objects.
+
+The internal representation of the rt-objects is not defined by this Recommendation. Each MHEG engine will have its own internal representation technique.
+
+NOTE – The model class contains no interchange attribute.
+
+## 21 Structure of Script Class
+
+An MHEG script class is defined for specifying complex conditional actions upon MHEG entities. The script objects, instances of script class, may be interchanged within or across applications. A script object is as a model object. From this model, rt-scripts may be created based on instructions given by the author.
+
+The MHEG script class provides the following information for the interchange of scripts.
+
+- Optional script classification (see clause 14): Provides as an assistance in determining the type of the script data.
+- Script hook (see clause 14): Identifies the scripting language and describes the encoding and decoding information enabling the use of the script data. It is composed of an identification and a description of the scripting language.
+- Script data: Inclusion or reference of the encoded script itself or to a “Null-Data”.
+
+## 22 Structure of Component Class
+
+The component class is an abstract class inherited by content class and composite class.
+
+The component objects, instances of component classes, may be interchanged within or across using applications.
+
+A component object is a model object. From this model, rt-components may be created based on instructions given by the author.
+
+In addition to the attributes inherited from model class, the component class defines an optional “OPS initialisation” attribute, which is composed of an OD and an OS. This attribute is used to initialise the OPS of each rt-component created from this component object. The OD and OS are used to initialise the OPS-T axis and X, Y, Z axes lengths. The AVR is set to the range value provided by this Recommendation. The OD and OS are provided as an optional assistance to the MHEG engine. It is for the object designer to ensure that this information is compatible with similar information that may be contained in the hook or in the data.
+
+## 23 Structure of Content Class
+
+This clause describes the support provided by this Recommendation for the handling of encoded data. This mechanism is common to all types of encoded data and provides a consistent approach to the identification of the type and the interchange of the following:
+
+- Data that may be presented to, and perceived by, the user, e.g. graphics, audio data.
+- Data that cannot be presented to the user in an immediate way.
+- Null data that may or may not be presented to the user depending on information given in hook or classification attributes or depending on the styles applied, e.g. a transparent area with a rectangle around the area.
+- Generic value stored in the data – This value may be presented to the user depending on information given in hook or classification attributes or depending on the styles applied, e.g. a numeric may be presented as a pure numeric or as a slider, a string as a pure string or as a button. This value may be also used to store a value to be retrieved later, e.g. for a comparison in a link condition or for another attribute assignment. Specific get data and set data actions allow to retrieve and to modify this value, e.g. Set CV [target set, Get Data (content target)].
+
+A content object is a model object. From this model, rt-contents may be created based on instructions given by the author.
+
+An MHEG content class is defined that provides the following information for the type identification and interchange of encoded data:
+
+- Optional data classification provided as an assistance in determining the type of the data. The classification is either proprietary or registered, e.g. generic value, graphics or video (see clause 14).
+- Content Hook describes the encoding and decoding information enabling the use of the encoded data (see clause 14).
+- Optional OV provided as an assistance in determining the current audible volume encoded within the data. When provided, this OV shall be defined within the AVR (see 9.1.3).
+- Content Data – Inclusion or reference to a generic value, an encoded data provided by other Recommendations and Standards and by this Recommendation or a “Null Data”. The generic value in this Recommendation is encoded in ASN.1 using the syntax defined for Generic Value in the Useful Definition module.
+
+## 24 Structure of Multiplexed Content Class
+
+This clause describes the support provided by this Recommendation for the handling of multiplexed data. This mechanism extends the mechanism provided by content class.
+
+An MHEG multiplexed content class provides a list of ordered streams in addition to the information provided by content class. It describes the streams contained in the multiplexed data.
+
+Each stream is composed of the following:
+
+- 1) Stream identifier – Each stream has a unique identification within a multiplex.
+- 2) Optional catalogued content classification – It is provided as an assistance in determining the type of this stream (see clause 14).
+- 3) Content hook – It describes the encoding and decoding information enabling the use of this stream (see clause 14).
+
+NOTE – An example of a multiplexed content object:
+
+- *Data Hook:*
+  - MPEG-System
+- *Data:*
+  - Multiplexed data
+- *Streams:*
+  - Stream identifier: 2.1, stream hook: MPEG2-Video
+  - Stream identifier: 2.4, stream hook: MPEG2-Audio
+  - Stream identifier: 2.5, stream hook: MPEG2-Audio
+
+## 25 Structure of Composite Class
+
+This class provides the support for associating multimedia and hypermedia objects. This mechanism provides a consistent approach to the synchronisation in time and space and linking of a set of objects.
+
+This class provides also the logical structure to describe the list of possible interactions offered to the user but does not define the interaction facilities provided by the user interface. Such interaction may be achieved in a variety of ways, for example, Graphical User Interfaces, keyboards, etc. This Recommendation does not define the look and feel of multimedia interactive presentations, or does it propose to change or add concepts to those that exist in typical Graphical User Interfaces. As this Recommendation is generic and independent of platform and implementation, it describes interaction at a virtual level. It is for a using application to apply these mechanisms using its specific look and feel.
+
+NOTE 1 – In this way, this Recommendation achieves a consistent interface between an MHEG engine and the user interaction services or other applications, while still allowing the author to maintain the local look and feel.
+
+Each composite object provides the means to describe one generation of information and its behaviour. Each generation is made up of a list of elements. The element is the basic building block of the composite class. Each element provides also a means to point to another generation defined by another composite object. Thus, a recursive structure is built up with the repetitive use of composite object and pointers in their elements.
+
+Each generation represents a unit in the logic of the presentation intended by the author.
+
+There are typically intrinsic relationships between sibling elements of a same generation.
+
+There are also typical intrinsic relationships of propagation between generations.
+
+NOTE 2 – A typical use of a composite object is to define one element for each choice to be offered to the user in the main menu. A second composite is used to describe the choices of the submenu.
+
+NOTE 3 – Another typical use of a composite object is to define elements that are to be presented simultaneously.
+
+The MHEG composite class provides the following information in addition to a generic identification of the composition:
+
+- 1) Composition behaviour: This set of behaviours may describe the sequencing and interrelationships between the elements of this composite and the hyperlinking between different kinds of information. The composition behaviour contains the following information:
+  - a) Predefined behaviour for specifying initial behaviours – The following start-up and close-down are defined:
+    - i) Availability start-up: When the composite object is prepared.
+    - ii) Availability close-down: When the composite object is destroyed.
+
+- iii) rt-availability start-up: When one rt-composite is created from the composite object.
+- iv) rt-availability close-down: When one rt-composite is deleted.
+- b) A set of links for specifying conditional actions.
+- c) A set of actions – Actions and links are used to describe the behaviour of each element and the interrelationships between parent and siblings.
+- 2) The number of elements contained in the composition defined by this composite.
+- 3) Composition elements – Each composite defines one generation. One generation is composed of the list of all the sibling elements.
+
+Empty elements are not represented in Figure 26.
+
+![Figure 26/T.171 – Example of a composite object structure. The diagram shows a hierarchy of composite objects. At the top is 'Composite A', which contains four elements: 'Index 1 Associated label "TITLE"', 'Index 3 Associated content object', 'Index 4 Associated multiplexed content object', and 'Index 5 Associated composite object'. Below 'Index 3' is a 'Content object'. Below 'Index 4' is a 'Multiplexed content object'. Below 'Index 5' is 'Composite B', which contains three empty slots represented by circles. A black rectangle is shown at the top of Composite A and above Composite B. The identifier 'T0825720-96/d025' is at the bottom right.](bd0283b61b6a59829e9370b29076c79a_img.jpg)
+
+Figure 26/T.171 – Example of a composite object structure. The diagram shows a hierarchy of composite objects. At the top is 'Composite A', which contains four elements: 'Index 1 Associated label "TITLE"', 'Index 3 Associated content object', 'Index 4 Associated multiplexed content object', and 'Index 5 Associated composite object'. Below 'Index 3' is a 'Content object'. Below 'Index 4' is a 'Multiplexed content object'. Below 'Index 5' is 'Composite B', which contains three empty slots represented by circles. A black rectangle is shown at the top of Composite A and above Composite B. The identifier 'T0825720-96/d025' is at the bottom right.
+
+**Figure 26/T.171 – Example of a composite object structure**
+
+## 25.1 Availability Start-up
+
+The availability start-up is a link object that always has the same link condition: when the preparation status of the composite object becomes ready [i.e. Get Preparation Status (“this”) becomes ready]. The link effect may be used for additional preparation effect of the composite. It is either a personalised link effect provided by the author or one of the following default link effects:
+
+- Automatic start-up 1: Activate all the included or referenced links within the specific behaviour.
+- Automatic start-up 2: Prepare all the referenced associated model objects.
+- Automatic start-up 3: Prepare all the referenced action and link objects in specific behaviour.
+- Automatic start-up 4: Activate all the included or referenced links within the specific behaviour, and prepare all the referenced associated model objects.
+- Automatic start-up 5: Prepare all the referenced associated model objects, and prepare all the referenced action and link objects in specific behaviour.
+
+When the availability start-up is omitted, there is no start-up effect, i.e. the availability start-up is inhibited.
+
+NOTE – The availability start-up is a link. It is not to be confused with a constructor. It is processed only when the composite object’s preparation status becomes “ready”.
+
+## 25.2 Availability Close-down
+
+The availability close-down is a link object that always has the same link condition: when the preparation status of the composite object becomes not ready. i.e. Get Preparation Status (“this”) becomes not ready. The link effect may be used for additional destruction effect of the composite. It is either a personalised link effect provided by the author or one of the following default link effects:
+
+- *Automatic Close-down 1:*
+  - destruction of referenced link and action objects in the specific behaviour;
+  - destruction of referenced action objects describing link effect in one of the link objects;
+  - destruction of nested action objects referenced in action objects included or referenced in composition behaviour;
+  - when completed, destruction of the availability close-down link itself.
+- *Automatic Close-down 2:*
+  - destruction of referenced associated components within the composition elements;
+  - when completed, destruction of the availability close-down link itself.
+- *Automatic Close-down 3:*
+  - destruction of referenced link and action objects in the specific behaviour;
+  - destruction of referenced action objects describing link effect in one of the link objects;
+  - destruction of nested action objects referenced in action objects included or referenced in composition behaviour;
+  - destruction of referenced associated components within the composition elements;
+  - when completed, destruction of the availability close-down link itself.
+
+When the availability close-down is omitted, there is no close-down effect, i.e. the availability close-down is inhibited.
+
+NOTE – The availability close-down is a link. It is not to be confused with a destructor. It is processed only when the composite object’s preparation status becomes “not ready”.
+
+## 25.3 RT-Availability Start-up
+
+The rt-availability start-up is a link object that always has the same link condition: when an rt-composite is created from this composite, i.e. Get Rt-Availability Status (“this”:?) becomes available. The link effect may be used for additional preparation effect of the rt-composite. It is either a personalised link effect provided by the author or the following default link effect:
+
+- Automatic Rt-Start-up: Run action is targeted to this rt-composite.
+
+When the rt-availability start-up is omitted, there is no start-up effect, i.e. the rt-availability start-up is inhibited.
+
+NOTE – The availability start-up is a link. It is not to be confused with a constructor of an rt-component. It is processed only when the rt-composite object’s Rt-Availability Status becomes “available” to each rt-composite created from this composite object.
+
+## 25.4 Rt-Availability Close-down
+
+The rt-availability close-down is a link object that always has the same link condition: when an rt-composite created from this composite becomes deleted, i.e. Get Rt-Availability Status (“this”:?) becomes not available. The link effect may be used for additional destruction effect of the rt-composite. It is always a personalised link effect provided by the author. When the rt-availability close-down is omitted, there is no close-down effect, i.e. the rt-availability close-down is inhibited.
+
+NOTE – The availability close-down is a link. It is not to be confused with a distracter of an rt-component. It is processed only when the rt-composite object’s rt-availability status becomes “not available” to each rt-composite created from this composite object.
+
+## 25.5 Composition Element
+
+Each element is composed of the following:
+
+- 1) A composition **element index** – Each element has a unique identification within a composite object.
+- 2) A **associated model** – The associated model may be used to associate information to be presented to the user. The model is either a label, a content, a composite, or an empty model:
+  - a) An label is a generic string – A label may be presented to the user as an interaction item following the style applied to the rt-composite. For example, a label may correspond to a title of a menu or push button.
+  - b) A content represents a terminal element that is either a content object or a multiplexed content object.
+  - c) A composite allows the build-up of a parent-child relationship through successive generations. It is the author's responsibility to avoid the appearance of cycle in the composite object, i.e. an element addressing an ascendant.
+  - d) An empty model – No model is associated with the element.
+
+When an rt-composite is created from the composite object, the MHEG engine creates rt-objects from the associated models described in the composition (an rt-content from an associated label or an associated content, an rt-composite from an associated composite, a “Null-Root-Rt” from an empty associated model). These rt-objects are plugged into the corresponding sockets within the rt-composite.
+
+## 25.6 Composition example
+
+Figure 27 shows an example of a menu using the root rt-composite 700:8 in Figure 20 created from composite 700 in Figure 18. Composite 700 defines a logical structure of composition independently of its presentation. In this example, a style menu has been applied to 700:8 in order to represent different generations of menus and submenus. The following applies:
+
+- The rt-content sockets: “FILE”, “OPTION”, “HELP” are presented in the principal menu.
+- The rt-composite sockets 700:8.2 and 700:8.4 represents the submenus.
+- The rt-content sockets: “open”, “close” and “new” are presented when the first menu is activated.
+- The rt-content socket: “easy” is presented when the second menu is activated.
+
+The presentation of this menu is not defined by this Recommendation; it is part of the look and feel of the presentation system.
+
+![Diagram of menu structure with submenus. The top row contains three boxes: FILE, OPTION, and HELP. Below FILE is a vertical stack of three boxes: open, close, and new. Below OPTION is a single box: easy. The diagram is labeled T0825730-96/d026.](13dbd16a58861b335d8e10047ae8e524_img.jpg)
+
+|       |        |      |
+|-------|--------|------|
+| FILE  | OPTION | HELP |
+| open  | easy   |      |
+| close |        |      |
+| new   |        |      |
+
+T0825730-96/d026
+
+Diagram of menu structure with submenus. The top row contains three boxes: FILE, OPTION, and HELP. Below FILE is a vertical stack of three boxes: open, close, and new. Below OPTION is a single box: easy. The diagram is labeled T0825730-96/d026.
+
+**Figure 27/T.171 – Example of menu structure with submenus**
+
+## 26 Structure of Container Class
+
+This clause describes the support provided for regrouping other MHEG objects. This regroupment is intended to facilitate the interchange in order to obtain a unique set of interchange. Once interchanged, it is ensured that all the included objects have also been interchanged.
+
+This may also be used by the object designer to regroup information participating in a same application.
+
+The container object provides the following facilities:
+
+- an optional predefined behaviour composed of a Container Start-up (see 26.1) and Container Close-down (see 26.2);
+- a list of Container Elements (see 26.3)
+
+### 26.1 Container Start-up
+
+The container start-up is a link object that always has the same link condition: when the preparation status of the container object becomes ready, i.e. Get Preparation Status (“this”) becomes ready. The link effect may be used for additional preparation effect of the container. It is either a personalised link effect provided by the author or one of the following default link effects:
+
+- Automatic Container Start-up 1: Prepare action is targeted to the included objects.
+- Automatic Container Start-up 2: Prepare action is targeted to the included and referenced objects.
+- Automatic Container Start-up 3: Activate link objects included.
+- Automatic Container Start-up 4: Activate link objects included and referenced.
+- Automatic Container Start-up 5: Prepare action is targeted to the included objects; Activate link objects included.
+- Automatic Container Start-up 6: Prepare action is targeted to the included objects; Activate link objects included and referenced.
+- Automatic Container Start-up 7: Prepare action is targeted to the included and referenced objects; Activate link objects included.
+- Automatic Container Start-up 8: Prepare action is targeted to the included and referenced objects; Activate link objects included and referenced.
+
+When the container start-up is omitted, there is no start-up effect, i.e. the container start-up is inhibited.
+
+NOTE – The container start-up is a link. It is not to be confused with a constructor. It is processed only when the container object’s preparation status becomes ready.
+
+### 26.2 Container Close-down
+
+The container close-down is a link object that always has the same link condition: when the preparation status of the container object becomes not ready, i.e. Get Preparation Status (“this”) = not ready. The link effect may be used for additional destruction effect of the container. It is either a personalised link effect provided by the author or one of the following default link effects:
+
+- Automatic Container Close-down;
+- Destruction of referenced objects;
+- when completed, destruction of the availability close-down link itself.
+
+When the container close-down is omitted, there is no close-down effect, i.e. the container close-down is inhibited.
+
+NOTE – The availability close-down is a link. It is not to be confused with a distracter. It is processed only when the container object’s preparation status becomes not ready.
+
+### 26.3 Container Element
+
+This is an ordered list of container elements. Each container element can be an instance of any other MHEG classes that may be included or referenced to. It may be one of the following:
+
+- action object;
+- link object;
+
+- script object;
+- content object;
+- multiplexed content object;
+- composite object;
+- container object;
+- descriptor object.
+
+A container element index is assigned to each container element. Each element has a unique identification within a container: the elements are all indexed from 1 to n by the MHEG engine.
+
+## 27 Structure of Descriptor Class
+
+This clause describes the support provided for the description of other objects that are interchanged. This description is intended to facilitate the negotiation, installation, operation and management of applications that use MHEG objects.
+
+It is recognised that different presentation systems may have widely differing capabilities. By interchanging and interpreting descriptor objects, it is possible to adapt the resources of the presentation system to the requirements of the described objects. The descriptor objects allow MHEG engines to determine whether or not they are able to proceed with a presentation and allow using applications to determine the resources that would be needed for a presentation of a set of objects.
+
+This Recommendation does not require that all objects that are interchanged be the subject of a descriptor object. If no descriptor is associated with an object, it is for the using application to define the description of the object. It is the responsibility of the author to ensure consistency between the descriptor objects and the described objects. This Recommendation does not provide mechanisms to handle errors or inconsistencies in descriptor objects.
+
+A number of facilities ranging from the informal to the formal may be provided by the descriptor object:
+
+- set of related objects (see 27.1);
+- other descriptor (see 27.2);
+- readme (see 27.3);
+- system readable material (see 27.4);
+- set of channel informations (see 27.5);
+- set of catalogued style informations (see 27.6);
+- set of catalogued extended elementary action informations (see 27.7);
+- set of Cat Ext Attribute Info (see 27.8).
+
+### 27.1 Related Object
+
+A set of related objects may be provided in order to specify the scope of the descriptor object. If this set is omitted, the scope of the descriptor object is defined by the using application. In this case, in general, the scope should include all objects belonging to the application. Each related object attribute provides information about a single related object; it is specified as a list of the following attributes:
+
+- Object reference: Identifies the related object to which this object information applies.
+- Object information: Optional. It defines more precisely the related object with the following attributes:
+  - Object size: Indicates the size of the encoded related object in octets (optional).
+  - Class ID: Identifies the class of the related object.
+  - A set of class-specific attributes: This is a choice of attributes sets, which carry object specific information on the related object:
+    - specific attributes on a related script object (see 27.1.1);
+    - specific attributes on a related content object (see 27.1.2);
+    - specific attributes on a related multiplexed content object (see 27.1.3).
+  - Offset: It provides a relative position in octets of an encoded object that is included in another encoded object (see 27.1.5).
+
+This Recommendation does not define how to handle contradictory descriptions, if a given related object is described more than once.
+
+### 27.1.1 Script Class Information
+
+This provides a set of attributes describing the related script object. The following information may be provided:
+
+- Script classification: Informs the executing system about the classification of the related script object (see 15.1).
+- Script hook: Informs the executing system about the script languages used by the related script object. The executing system may use this information to prepare the corresponding script interpreter or to reject this script object if this script interpreter is not available (see clause 14).
+
+### 27.1.2 Content Class Information
+
+This provides a set of attributes describing the related content object. The following information may be provided:
+
+- Content classification: Informs the executing system about the classification of the related content object (see 15.1).
+- Content hook: Informs the executing system about the encoding used for the data of the related content. The executing system may use this information to prepare the corresponding decoder (see clause 14).
+- Alternative objects: Provides a facility to indicate alternative content objects that may be used instead of this related content (see 27.1.4).
+
+### 27.1.3 Mux Content Class Info
+
+This provides a set of attributes describing the related multiplexed content object. The following information may be provided:
+
+- Content class information: Informs the executing system about the whole multiplexed data of the related multiplexed content object, i.e. classification, hook, alternative objects (see 27.1.2).
+- Number of streams: Reflects the number of streams contained within the multiplexed data of the related object.
+- Set of stream information: Each stream information is composed of the following attributes:
+  - Stream identifier: Identifies a stream within the related multiplexed content object.
+  - Content class information: A single stream can be regarded as a single content object; therefore, the attribute set that describes a related content is used, i.e. classification, hook, alternative objects (see 27.1.2).
+
+### 27.1.4 Alternative Object
+
+This provides information about possible alternative content objects that may replace the related object.
+
+Alternative content objects may differ in the encoding or in any other attributes from the related object. The using application may use this facility to adapt the data to be presented to the local environment. It is up to the author of the descriptor to ensure the integrity of alternative objects in the context of the related object.
+
+The alternative objects are described as a list of alternative objects. Each alternative object is composed of the following attributes:
+
+- A reference to an alternative content object.
+- An alternative hook: Specifying the hook of the alternative object.
+- An alternative descriptor object: Reference to the descriptor object describing the alternative object. It is optional.
+- An alternative readme: Optional and specified as a free format string. It may be used by the using application to identify the nature of the alternative object. For example, in a multi-language application, the readme may carry an identification of the language of the alternative object. It is up to the using application to interpret the meaning of the readme.
+
+### **27.1.5 Offset**
+
+An encoded MHEG object may be included within another encoded MHEG object. In order to retrieve this included MHEG object without decoding from the beginning, offset information may be provided. The offset indicates the first octet of the included MHEG object in level-D representation.
+
+## **27.2 Other Descriptor**
+
+A set of references to other descriptor objects may be provided and used by the author to connect different descriptor objects. The connected descriptor objects may describe different objects, and the scope of the descriptors may differ. This Recommendation does not define how to handle contradictory descriptions if the scope of two or more descriptors overlap.
+
+This facility provides a mechanism to create a structured set of descriptors. Possible structures are linked lists or trees. It is in the responsibility of the author to define a useful structure.
+
+## **27.3 Readme**
+
+This informal text provides for a human being with the information and encouragement needed to proceed with the installation and operation of the set of related MHEG objects. The choice of words is left to the author, who may use the readme to point to further sources of information and support.
+
+## **27.4 System Readable Material**
+
+A using application may place information in the descriptor object which it finds useful. This Recommendation does not define either this information or the encoding used by the application. An author or a using application may include information in the descriptor intended for the MHEG engine. However, the author should be aware that this information may not be portable to other MHEG systems.
+
+## **27.5 Channel Information**
+
+A set of channel information may be provided by the author in order for the MHEG engine to map more easily each channel on the real environment. Each channel may be described as follows:
+
+- Channel ID: Identifies the channel to be described.
+- x-min, x-max, y-min, y-max, z-min, z-max: Describe for each spatial axis the minimum and maximum values required for the device associated with this channel.
+- x-resolution, y-resolution, z-resolution: Describe for each spatial axis the resolution for the device associated with this channel. This is the number of addressable spatial physical units.
+- t-resolution: Describes the temporal resolution for the device associated with this channel. This is the number of addressable temporal physical units within one second.
+- f-min, f-max: Define the minimum and maximum presentable frequency required for that channel if audible media are presented on this channel. The units are “hertz”.
+- Audio-dynamic: Defines the audio dynamic required for that channel if audible media are presented on this channel. The units are “dB”.
+- Media types: Specifies the types of the media of the rt-components assigned on this channel. This allows the MHEG engine to assign channels to physical devices. It is one of the catalogued values that can be either registered or proprietary. However, if the presentation system does not support the requested device, the engine may ignore the media type.
+- Events mapping: Specifies the expected events that may occur on this channel or on the rt-components assigned to this channel. It is also possible to assign a catalogued event to each event. This allows an MHEG engine to map the event defined by the author to a real event that may occur in its environment. The catalogued event can be either registered or proprietary. If no mapping on a catalogued event is provided, it is considered that the event identifier provided by the author directly map on catalogued event identifier. If this is not the case, it is for the using application to define how to map the event identifier on a real event. This Recommendation does not define how to handle contradictory descriptions if a given event identifier is mapped more than once.
+
+This Recommendation does not define how to handle contradictory descriptions if a given channel is described more than once.
+
+## 27.6 Catalogued Style Information
+
+A set of catalogued styles may be provided in order to inform the executing system about the catalogued styles used in the Set Style actions interchanged in related action objects. The catalogued style can be either registered or proprietary.
+
+## 27.7 Cat Ext elementary action info
+
+A set of catalogued extended elementary actions may be provided in order to inform the executing system about the catalogued extended elementary actions used in the Catalogued elementary action interchanged in related action objects. The catalogued extended elementary actions can be either registered or proprietary.
+
+## 27.8 Cat Ext Attribute Info
+
+A set of Cat Ext Attributes may be provided in order to inform the executing system about the Cat Ext Attributes used in the Set Catalogued Attribute actions interchanged in related action and link objects. The Cat Ext Attributes can be either registered or proprietary.
+
+# SECTION 4 – MHEG ENTITIES COMMON BEHAVIOUR
+
+This Recommendation defines the expected behaviour and the initial expected behaviour of the MHEG objects, rt-objects and channels through behaviour attributes and their status values. This Recommendation also defines actions to change and retrieve each expected behaviour. The processing effects of these actions that are perceptible to the user are called “user effects”, and the processing effects whose results are only available to the MHEG engine are called “MHEG effect”. Only the MHEG effect is defined by this Recommendation. The user effect is perceived by the user via a certain GUI that decides look and feel of MHEG entities.
+
+## 28 MHEG entity behaviour
+
+The initial behaviour of each MHEG entity provided by this Recommendation may be changed by the interchanging the following instances of MHEG classes:
+
+- Action class used to interchange a set of actions with target references to MHEG objects, rt-objects or channels;
+- Link class used to interchange a set of actions and to specify conditions for those actions;
+- Script class used to interchange scripts that describe complex behaviours.
+
+## 29 MHEG entity state definition
+
+The complete life of an MHEG object, an rt-object or a channel is defined by the following series of diagrams. As some actions are only valid for a certain period of an MHEG entity, the definition of MHEG entity life is used to verify the validity of an action. Two description methods are used as follows:
+
+- 1) Timing diagrams describe the principal behaviour along with the time as shown in Figure 28. This figure shows a status change of a certain MHEG entity. First, this is in period i. After targeting a certain action to this entity, there is some MHEG effect caused by an MHEG engine or a GUI, but still the entity remains in period i. This means that a Get action targeted to the entity during the processing of an MHEG effect always retrieves the value that was attached to the period (the value in period i). After finishing the processing of the MHEG effect, the entity enters in period j. If the period j has some user effect, the appearance of the entity is changed and perceived by a user. The duration of MHEG effect and possible user effect are shown as in Figure 28.
+- 2) Finite state diagrams describe the possible state transitions depending on actions as shown in Figure 29. In this figure, two ellipses (State1, State2) represent states, and 3 boxes (action x, action y, action z) stand for actions that may modify states. The initial status is State1. If action x is targeted, the state remains State1. If action y is targeted after that, the state is changed to State2. And action z causes a retransition to State1. Action x and y are not valid and ignored if the state is State2, and action z is not valid and ignored if the state is State1.
+
+![Figure 28/T.171: Example of timing diagram. The diagram shows a horizontal timeline 't' with two periods, 'Period i' and 'Period j'. An 'Action' box points to the boundary between Period i and Period j. A 'MHEG effect' box is shown below the timeline, starting at the boundary and extending into Period j. A 'User effect' box is shown below the timeline, starting later and extending into Period j. The reference T0825740-96/d027 is at the bottom right.](b3335932702b8668e62791e9fd12c9ff_img.jpg)
+
+Figure 28/T.171: Example of timing diagram. The diagram shows a horizontal timeline 't' with two periods, 'Period i' and 'Period j'. An 'Action' box points to the boundary between Period i and Period j. A 'MHEG effect' box is shown below the timeline, starting at the boundary and extending into Period j. A 'User effect' box is shown below the timeline, starting later and extending into Period j. The reference T0825740-96/d027 is at the bottom right.
+
+Figure 28/T.171 – Example of timing diagram
+
+![Figure 29/T.171: Example of finite state diagrams. The diagram shows two states, 'State1' and 'State2', represented as ovals. 'State1' is labeled 'Initial state'. A self-loop arrow on 'State1' is labeled 'Action x'. A downward arrow from 'State1' to 'State2' is labeled 'Action y'. An upward arrow from 'State2' to 'State1' is labeled 'Action z'. The reference T0825750-96/d028 is at the bottom right.](909726977de6efd2d4df015198a2907b_img.jpg)
+
+Figure 29/T.171: Example of finite state diagrams. The diagram shows two states, 'State1' and 'State2', represented as ovals. 'State1' is labeled 'Initial state'. A self-loop arrow on 'State1' is labeled 'Action x'. A downward arrow from 'State1' to 'State2' is labeled 'Action y'. An upward arrow from 'State2' to 'State1' is labeled 'Action z'. The reference T0825750-96/d028 is at the bottom right.
+
+Figure 29/T.171 – Example of finite state diagrams
+
+Several periods of MHEG entities are defined for the following behaviours:
+
+- MHEG object availability (see 29.1);
+- Link object activation (see 29.2);
+- Channel availability (see 29.3);
+- RT-object availability (see 29.4);
+- Rt-Component running behaviour (see 29.5);
+- Rt-Component presentation behaviour (see 29.6).
+
+## 29.1 MHEG object availability
+
+Figures 30 and 31 show MHEG object availability. Two states are defined as follows:
+
+- **O1:** The MHEG object is not known to the MHEG engine. Even if it is not created, the MHEG object is said to be in period O1. During O1, all MHEG objects except link objects have only one attribute: preparation status which is equal to “not ready”. Link objects additionally have the activation status which is equal to “inactive”. Any other object attributes described in this Recommendation do not exist. Any Get actions evaluate “undefined” to these non-existing attributes.
+- **O2:** The MHEG object is available to the MHEG engine. The preparation status of the MHEG object is “ready”. The object has been decoded. All other object attributes have been created and set to their corresponding interchanged values.
+
+![Timing diagram of MHEG object availability showing objects O1 and O2 over time t. O1 is 'not ready' before and after O2 is 'ready'. Prepare and Destroy actions are shown above the timeline.](a37adbbe12ec735a20ead2466363d07a_img.jpg)
+
+The diagram shows a horizontal timeline labeled 't'. Above the timeline, a box labeled 'Prepare' has an arrow pointing to the start of the first 'O1' block. A box labeled 'Destroy' has an arrow pointing to the start of the 'O2' block. The timeline is divided into three segments by vertical dashed lines. The first segment is labeled 'O1' and contains a box 'Preparation status = "not ready"'. The second segment is labeled 'O2' and contains a box 'Preparation status = "ready"'. The third segment is labeled 'O1' and contains a box 'Preparation status = "not ready"'. The 'O2' block is shaded grey. The timeline ends with an arrow pointing to the right, labeled 't'.
+
+T0825760-96/d029
+
+Timing diagram of MHEG object availability showing objects O1 and O2 over time t. O1 is 'not ready' before and after O2 is 'ready'. Prepare and Destroy actions are shown above the timeline.
+
+**Figure 30/T.171 – Timing diagram of MHEG object availability**
+
+![Finite state diagram of MHEG object availability showing states O1 and O2. O1 is the initial state. Transitions are labeled Prepare and Destroy.](592f13acca3e6d5152dd4489f030d004_img.jpg)
+
+The diagram shows two states, O1 and O2, represented by ovals. O1 is the 'Initial state', indicated by an arrow from the right. There are self-loop arrows on both O1 and O2. Transitions between O1 and O2 are labeled 'Prepare' (from O1 to O2) and 'Destroy' (from O2 to O1). There is also a 'Destroy' label with a self-loop arrow on O1. A 'Prepare' label with a self-loop arrow is on O2.
+
+T0825770-96/d030
+
+Finite state diagram of MHEG object availability showing states O1 and O2. O1 is the initial state. Transitions are labeled Prepare and Destroy.
+
+**Figure 31/T.171 – Finite state diagram of MHEG object availability**
+
+## 29.2 Link activation
+
+Figures 32 and 33 show link activation. Link objects have additionally MHEG object availability states because they are also MHEG objects. The two figures also show the relationship between MHEG object availability and link activation. Two states are defined for link activation as follows:
+
+- **L1:** The activation status of the link object is “inactive”. This link cannot be fired.
+- **L2:** The activation status of the link object is “active”. The link object has been activated. During L2, each time the link condition becomes true, the link is fired. The Link Abort action does not affect these states.
+
+An Activate action targeted to a link whose preparation status is “not ready” implicitly executes a Prepare action.
+
+A Destroy action may also be targeted in L2. Then the link object enters directly in period L1/O1.
+
+![Timing diagram of link object availability and activation. The diagram shows a sequence of events over time (t). The top row shows objects O1, O2, and O1. The middle row shows links L1, L2, and L1. The bottom row shows the preparation and activation status for each object-link pair. Transitions are triggered by Prepare, Activate, Deactivate, and Destroy events.](3481cde1adf61b0452dd6489dada6d6a_img.jpg)
+
+| Event      | Object | Link | Preparation status | Activation status |
+|------------|--------|------|--------------------|-------------------|
+| Prepare    | O1     | L1   | "not ready"        | "inactive"        |
+| Activate   | O2     | L2   | "ready"            | "inactive"        |
+| Deactivate | O2     | L2   | "ready"            | "active"          |
+| Destroy    | O1     | L1   | "ready"            | "inactive"        |
+|            | O1     | L1   | "not ready"        | "inactive"        |
+
+Timing diagram of link object availability and activation. The diagram shows a sequence of events over time (t). The top row shows objects O1, O2, and O1. The middle row shows links L1, L2, and L1. The bottom row shows the preparation and activation status for each object-link pair. Transitions are triggered by Prepare, Activate, Deactivate, and Destroy events.
+
+T0825780-96/d031
+
+Figure 32/T.171 – Timing diagram of link object availability and activation
+
+![Finite state diagram of link object availability and activation. The diagram shows three states: O1/L1, O2/L1, and O2/L2. Transitions are labeled with events: Prepare, Activate, Deactivate, Destroy, and Initial state.](de63e4b6d8b0aa76b85e1fe3236eac27_img.jpg)
+
+```
+
+graph TD
+    O1L1([O1/L1])
+    O2L1([O2/L1])
+    O2L2([O2/L2])
+
+    O1L1 -- Prepare --> O2L1
+    O2L1 -- Prepare --> O1L1
+    O1L1 -- Activate --> O2L2
+    O2L2 -- Activate --> O1L1
+    O1L1 -- Deactivate --> O2L1
+    O2L1 -- Deactivate --> O1L1
+    O1L1 -- Destroy --> O1L1
+    O2L1 -- Destroy --> O1L1
+    O2L2 -- Destroy --> O1L1
+    O2L1 -- Destroy --> O2L2
+    O2L2 -- Destroy --> O2L1
+    O2L1 -- Prepare --> O2L1
+    O2L2 -- Prepare --> O2L2
+    O2L1 -- Deactivate --> O2L1
+    O2L2 -- Deactivate --> O2L2
+    O2L1 -- Activate --> O2L2
+    O2L2 -- Activate --> O2L1
+    O1L1 -- Initial state --> O1L1
+  
+```
+
+Finite state diagram of link object availability and activation. The diagram shows three states: O1/L1, O2/L1, and O2/L2. Transitions are labeled with events: Prepare, Activate, Deactivate, Destroy, and Initial state.
+
+T0825790-96/d032
+
+Figure 33/T.171 – Finite state diagram of link object availability and activation
+
+### 29.3 Channel availability
+
+Figures 34 and 35 show channel availability. Two states are defined as follows:
+
+- **C1:** The channel is not yet created, and not available to the MHEG engine.
+- **C2:** The channel is available to the MHEG engine.
+
+The default channel can neither be created nor be deleted. It is always available to the MHEG engine (i.e. the default channel is always in state C2). Both New channel and Delete channel are ignored for the default channel.
+
+![Timing diagram of channel availability showing states C1 and C2 over time t. Transitions are triggered by 'New channel' and 'Delete channel' events. Availability status is 'not available' for C1 and 'available' for C2.](48adb97a6a4a14b039450192f25cc1e0_img.jpg)
+
+The diagram illustrates the timing of channel availability. A horizontal timeline labeled 't' shows three segments. The first segment is labeled 'C1' and has a box below it stating 'Channel availability status = "not available"'. A 'New channel' event triggers a transition to the second segment, labeled 'C2', which has a box below it stating 'Channel availability status = "available"'. A 'Delete channel' event triggers a transition to the third segment, labeled 'C1', which also has a box below it stating 'Channel availability status = "not available"'. Vertical dashed lines separate the segments, and a horizontal arrow indicates the progression of time 't'.
+
+T0825800-96/d033
+
+Timing diagram of channel availability showing states C1 and C2 over time t. Transitions are triggered by 'New channel' and 'Delete channel' events. Availability status is 'not available' for C1 and 'available' for C2.
+
+Figure 34/T.171 – Timing diagram of channel availability
+
+![Finite state diagram of channel availability with states C1 and C2. Transitions are labeled 'New channel' and 'Delete channel'. C1 is the initial state.](e16bfa31d748f4d99ec4ae3d16656926_img.jpg)
+
+The diagram shows a finite state model with two states, C1 and C2, represented as ovals. C1 is labeled 'Initial state'. Transitions are represented by arrows: a self-loop on C1 labeled 'Delete channel', a transition from C1 to C2 labeled 'New channel', a transition from C2 to C1 labeled 'Delete channel', and a self-loop on C2 labeled 'New channel'.
+
+T0825810-96/d034
+
+Finite state diagram of channel availability with states C1 and C2. Transitions are labeled 'New channel' and 'Delete channel'. C1 is the initial state.
+
+Figure 35/T.171 – Finite state diagram of channel availability
+
+## 29.4 Rt-object availability
+
+Figures 36 and 37 show rt-object availability. They also show the relationship between rt-object availability status and MHEG object availability status belonging to the model object from which the rt-object is derived. Two states are defined as follows:
+
+- **R1:** The model object is prepared (O2), the rt-object is not created, it is not available.
+- **R2:** The rt-object is available to the MHEG engine. During this period the rt-object may be presented, using a Run action.
+
+A New action in O1/R1 prepares the model object implicitly. And a Destroy action in O2/R2 deletes all rt-objects created from this model implicitly.
+
+![Timing diagram of rt-object availability showing Model object and Rt-object states over time.](3a006a7c9c9934695f0fc731344eff8a_img.jpg)
+
+The diagram illustrates the timing of rt-object availability across two layers: Model object and Rt-object, over a time axis *t*.
+
+| Model object | Rt-object | Preparation status | Rt-object availability status |
+|--------------|-----------|--------------------|-------------------------------|
+| O1           | R1        | not ready          | not available                 |
+| O2           | R2        | ready              | not available                 |
+| O2           | R2        | ready              | available                     |
+| O2           | R2        | ready              | not available                 |
+| O1           | R1        | not ready          | not available                 |
+
+Transitions are triggered by: Prepare (O1 to O2), New (O2 to R2), Delete (R2 to O2), and Destroy (O2 to O1).
+
+T0825820-96/d035
+
+Timing diagram of rt-object availability showing Model object and Rt-object states over time.
+
+Figure 36/T.171 – Timing diagram of rt-object availability
+
+![State transition diagram for rt-object availability showing states O1/R1, O2/R1, and O2/R2.](56a42b3c4e1a79a71c8f27aa03b78b84_img.jpg)
+
+```
+
+graph TD
+    O1R1([O1/R1]) -- Prepare --> O2R1([O2/R1])
+    O2R1 -- Destroy --> O1R1
+    O1R1 -- New --> O2R2([O2/R2])
+    O2R2 -- Destroy --> O1R1
+    O2R1 -- New --> O2R2
+    O2R2 -- Delete --> O2R1
+    O2R1 -- Prepare --> O2R1
+    O2R1 -- Delete --> O2R1
+    O2R2 -- Prepare --> O2R2
+    O2R2 -- New --> O2R2
+  
+```
+
+The diagram shows three states: O1/R1 (Initial state), O2/R1, and O2/R2. Transitions are labeled with actions: Prepare, Destroy, New, and Delete.
+
+T0825830-96/d036
+
+State transition diagram for rt-object availability showing states O1/R1, O2/R1, and O2/R2.
+
+Figure 37/T.171 – Timing diagram of rt-object availability
+
+## 29.5 Rt-Component running behaviour
+
+Figures 38 and 39 show rt-component running behaviour. Once an rt-component is “available” (i.e. in R2), it is ready for presentation. Two states are defined as follows:
+
+- **R2:** The rt-component is not running. It is not presented to the user.
+- **R3:** The rt-component is running. It may be presented to the user. During this period, there may be a user effect, which is the result of the running of the rt-component to the user with the specified behaviour attributes. The user effect may be dependent of each MHEG engine and GUI.
+
+If a Run action is targeted to a non-existing rt-component (i.e. the rt-object is in R1), an implicit New action is targeted to this rt-component before processing the Run.
+
+![Timing diagram of rt-component that is 'running'](e26bb66586e464339df27951d5c9355e_img.jpg)
+
+The diagram shows a sequence of states over time (t). A horizontal timeline is divided into three segments by vertical dashed lines. Above the timeline, a 'Run' action box points to the start of the first segment, and a 'Stop' action box points to the start of the second segment. The states are represented by boxes labeled R2, R3, and R2. The first and third segments are labeled 'Running status = "not running"', while the middle segment is labeled 'Running status = "running"'. A horizontal arrow labeled 't' indicates the progression of time.
+
+T0825840-96/d037
+
+Timing diagram of rt-component that is 'running'
+
+Figure 38/T.171 – Timing diagram of rt-component that is “running”
+
+![Running behaviour finite state diagram](5a01395925fc88802da68fb5ac0f31ff_img.jpg)
+
+The diagram shows a finite state machine with two states, R2 and R3, represented by ovals. R2 is the 'Initial state', indicated by an arrow from the text 'Initial state'. Transitions are as follows: a self-loop on R2 labeled 'Stop'; a transition from R2 to R3 labeled 'Run'; a self-loop on R3 labeled 'Run'; and a transition from R3 back to R2 labeled 'Stop'.
+
+T0825850-96/d038
+
+Running behaviour finite state diagram
+
+Figure 39/T.171 – Running behaviour finite state diagram
+
+## 29.6 Rt-Component presentation behaviour
+
+While an rt-component is running (i.e. the rt-component is in R3), presentation behaviour attributes may be changed by targeting certain Set actions.
+
+Figure 40 shows a typical example of a presentation behaviour attribute. In this figure, a presentation behaviour attribute called “A” associated with a certain rt-component is changed from value V0 to V1 during R3 of the rt-component. A user effect may be associated with this attribute value changing. After stopping this rt-component, the attribute A remains as V1 independent of the running status and any other attributes.
+
+![Figure 40/T.171 – Presentation behaviour attributes changing. A timeline diagram showing the state of an rt-component and its presentation behaviour attribute A over time. The timeline is divided into five segments: 1. 'not running' (R2), 2. 'running' (R3) with Attribute A = V0, 3. 'running' (R3) with Attribute A = V1, 4. 'not running' (R2) with Attribute A = V1, and 5. 'running' (R3) with Attribute A = V1. Transitions are marked by 'Run' and 'Stop' actions. A 'Set a presentation behaviour attribute A to V1' action occurs during the second R3 segment. A horizontal arrow labeled 't' indicates the progression of time.](6a993bfdf2e00cfad01c4d2188a75d86_img.jpg)
+
+The diagram illustrates the state transitions of an rt-component and its presentation behaviour attribute A over time. The timeline is divided into five segments, each with a specific running status and attribute value:
+
+- Segment 1:** Running status = "not running", Attribute A = V0. This segment is labeled R2.
+- Segment 2:** Running status = "running", Attribute A = V0. This segment is labeled R3. A "Set a presentation behaviour attribute A to V1" action is triggered during this segment.
+- Segment 3:** Running status = "running", Attribute A = V1. This segment is also labeled R3.
+- Segment 4:** Running status = "not running", Attribute A = V1. This segment is labeled R2.
+- Segment 5:** Running status = "running", Attribute A = V1. This segment is labeled R3.
+
+Transitions between segments are marked by "Run" and "Stop" actions. A horizontal arrow labeled "t" indicates the progression of time.
+
+Figure 40/T.171 – Presentation behaviour attributes changing. A timeline diagram showing the state of an rt-component and its presentation behaviour attribute A over time. The timeline is divided into five segments: 1. 'not running' (R2), 2. 'running' (R3) with Attribute A = V0, 3. 'running' (R3) with Attribute A = V1, 4. 'not running' (R2) with Attribute A = V1, and 5. 'running' (R3) with Attribute A = V1. Transitions are marked by 'Run' and 'Stop' actions. A 'Set a presentation behaviour attribute A to V1' action occurs during the second R3 segment. A horizontal arrow labeled 't' indicates the progression of time.
+
+T0825860-96/d039
+
+Figure 40/T.171 – Presentation behaviour attributes changing
+
+Figure 41 shows a presentation behaviour attribute changing with a certain transition duration. When an rt-component is running, a certain Set action is targeted to it in order to change the presentation behaviour attribute A gradually. In this case, one additional state period R3.TD is defined as follows:
+
+- R3.TD:** The rt-component running status is “running”. The MHEG engine is processing the attribute changing with the transition duration caused by a certain Set action. The duration of R3.TD is equal to the transition duration specified in the Set action. During R3.TD, the value of the specified attribute is changing gradually. When such an action is in a serial synchronised group of actions, the following action in the list is to be processed after the completion of R3.TD. A user effect may be associated with R3.TD. It shows the impact of the transition duration on the attribute value perception. The user may gradually perceive the change of the presentation behaviour attribute value from the previous value to the specified value. The user effect may be dependent of each MHEG engine and GUI.
+
+The MHEG effect of a Set action with some transition duration is composed of two parts:
+
+- the initial processing of the Set action in R3; and
+- the consecutive processing of the attribute changing gradually in R3.TD.
+
+![Timing diagram of Set actions with transition duration (Figure 41/T.171).](bd33d5bc49161429f4c7da76529bcd18_img.jpg)
+
+The diagram illustrates the timing of a Set action with a transition duration. At the top, a box contains the text: "Set presentation behaviour attribute A to V1 with transition duration equal to td." An arrow points from this box to a horizontal timeline labeled 't'. Above the timeline, a double-headed arrow indicates a duration 'td'. The timeline is divided into three segments by vertical dashed lines. The first segment is labeled 'R3' and contains a box with "Presentation behaviour attribute A = V0". The second segment is labeled 'R3.TD' and contains a box with "Presentation behaviour attribute A changes from V0 to V1 gradually". The third segment is labeled 'R3' and contains a box with "Presentation behaviour attribute A = V1". A horizontal arrow labeled 't' points to the right, indicating the progression of time. The reference code "T0825870-96/d040" is located at the bottom right.
+
+Timing diagram of Set actions with transition duration (Figure 41/T.171).
+
+**Figure 41/T.171 – Timing diagram of Set actions with transition duration**
+
+When an MHEG effect of a transition duration is under process and a Stop action is issued on this rt-component, the MHEG effect of the transition duration is terminated after the MHEG effect of the Stop action is completed. The presentation behaviour attribute value takes the specified value in the Set action as if no transition duration was specified. Figure 42 shows this situation.
+
+![Timing diagram of a Set action with transition duration when a Stop action occurs (Figure 42/T.171).](d04c50badc78d5ba47bf4e352af4a754_img.jpg)
+
+The diagram illustrates the timing of a Set action with a transition duration when a Stop action occurs. At the top, a box contains the text: "Set presentation behaviour attribute A to V1 with transition duration equal to td." An arrow points from this box to a horizontal timeline labeled 't'. Above the timeline, a double-headed arrow indicates a duration 'td'. A box labeled "Stop" has an arrow pointing to the timeline. The timeline is divided into three segments by vertical dashed lines. The first segment is labeled 'R3' and contains a box with "Presentation behaviour attribute A = V0". The second segment is labeled 'R3.TD' and contains a box with "Presentation behaviour attribute A changes from V0 to V1 gradually". The third segment is labeled 'R2' and contains a box with "Presentation behaviour attribute A = V1". A horizontal arrow labeled 't' points to the right, indicating the progression of time. The reference code "T0825880-96/d041" is located at the bottom right.
+
+Timing diagram of a Set action with transition duration when a Stop action occurs (Figure 42/T.171).
+
+**Figure 42/T.171 – Timing diagram of a Set action with transition duration when a Stop action occurs**
+
+When an MHEG effect of a transition duration is under process and a Set action is issued on the same attribute, the MHEG effect of the transition duration is terminated. The presentation behaviour attribute value takes the value specified by the last Set action. If the last Set action has no transition duration, the MHEG effect is processed as described in Figure 40. If it has transition duration, the MHEG effect is processed as described in Figure 41. Figure 43 shows an example of the former case.
+
+![Timing diagram of an interrupted set action with transition duration. The diagram shows a timeline with three phases: R3, R3.TD, and R3. Above the timeline, two boxes indicate 'Set presentation behaviour attribute A to V1 with transition duration equal to td.' and 'Set presentation behaviour attribute A to V2'. A double-headed arrow labeled 'td' spans the R3.TD phase. Below the timeline, three boxes show the state of 'Presentation behaviour attribute A': V0 in R3, a gradual change from V0 to V1 in R3.TD, and V2 in the final R3 phase. A horizontal arrow labeled 't' indicates the progression of time.](9687bd5e8b62cadba093b0d1b70536cd_img.jpg)
+
+Set presentation behaviour attribute A to V1 with transition duration equal to td.
+
+Set presentation behaviour attribute A to V2
+
+td
+
+R3 R3.TD R3
+
+t
+
+Presentation behaviour attribute A = V0
+
+Presentation behaviour attribute A changes from V0 to V1 gradually
+
+Presentation behaviour attribute A = V2
+
+T0825890-96/d042
+
+Timing diagram of an interrupted set action with transition duration. The diagram shows a timeline with three phases: R3, R3.TD, and R3. Above the timeline, two boxes indicate 'Set presentation behaviour attribute A to V1 with transition duration equal to td.' and 'Set presentation behaviour attribute A to V2'. A double-headed arrow labeled 'td' spans the R3.TD phase. Below the timeline, three boxes show the state of 'Presentation behaviour attribute A': V0 in R3, a gradual change from V0 to V1 in R3.TD, and V2 in the final R3 phase. A horizontal arrow labeled 't' indicates the progression of time.
+
+**Figure 43/T.171 – Timing diagram of an interrupted set action with transition duration**
+
+Figure 44 shows presentation behaviour attribute changing while an rt-component is “not running”. The rt-component has a presentation behaviour attribute A equal to V0 while it is in R2. When a Set action to change the presentation behaviour attribute A is targeted to this rt-component, the MHEG engine processes the MHEG effect of this Set action. If a transition duration is specified, it is set to 0 meaning that the transition duration is ignored. After processing the MHEG effect, the presentation behaviour attribute A is equal to V1. If a Run action targeted after that, the rt-component is presented with the presentation behaviour attribute A equal to V1.
+
+![Timing diagram of set actions on an rt-component that is 'not running'. The diagram shows a timeline with three phases: R2, an unlabeled phase, and R3. Above the timeline, two boxes indicate 'Set presentation behaviour attribute A to V1 with or without transition duration.' and 'Run'. Below the timeline, three boxes show the state of 'Presentation behaviour attribute A': V0 in R2, V1 in the unlabeled phase, and V1 in R3. A horizontal arrow labeled 't' indicates the progression of time.](e18841eb4a995df8354a793459e12fd0_img.jpg)
+
+Set presentation behaviour attribute A to V1 with or without transition duration.
+
+Run
+
+R2 R3
+
+t
+
+Presentation behaviour attribute A = V0
+
+Presentation behaviour attribute A = V1
+
+Presentation behaviour attribute A = V1
+
+T0825900-96/d043
+
+Timing diagram of set actions on an rt-component that is 'not running'. The diagram shows a timeline with three phases: R2, an unlabeled phase, and R3. Above the timeline, two boxes indicate 'Set presentation behaviour attribute A to V1 with or without transition duration.' and 'Run'. Below the timeline, three boxes show the state of 'Presentation behaviour attribute A': V0 in R2, V1 in the unlabeled phase, and V1 in R3. A horizontal arrow labeled 't' indicates the progression of time.
+
+**Figure 44/T.171 – Timing diagram of set actions on an rt-component that is “not running”**
+
+## 30 Life cycle of MHEG entities
+
+MHEG entities are created and destroyed by using elementary actions. The period between those two actions makes the life of an MHEG entity. During the life, some attributes associated with the MHEG entity are used.
+
+The principal rules between an MHEG entity life and associated attributes are as follows:
+
+- Even if such an MHEG entity does not exist, preparation status (see 29.1), rt-availability status (see 29.4) or channel availability status (see 29.3) exists and is always available. The preparation status is set to “not ready”, the rt-availability status is set to “not ready”, and the channel availability status is set to “not available”.
+- If a Prepare action (see 29.1), a New action (29.4) or a New Channel action (see 29.3) is targeted, the MHEG engine is required to instantiate the specified MHEG entity with its corresponding attributes which are described in different behaviours. The presentation status is set to “ready”, the rt-availability status is set to “ready” and the channel availability status is set to “available”.
+- If a Destroy action (see 29.1), a Delete action (see 29.4) or a Delete Channel action (see 29.3) is targeted, the MHEG engine is required to remove the specified MHEG entity with its corresponding associated attributes except for the preparation status, rt-availability status and channel availability status that are set to “not ready”, “not ready” and “not available”, respectively.
+
+Therefore, if an MHEG entity is destroyed or deleted, only the preparation status, the rt-availability status or the channel availability status is changed. And if there is a link whose condition is “when the preparation status becomes “not ready””, “when the rt-availability status becomes “not ready”” or “when the channel availability status becomes “not available””, it shall be triggered.
+
+On the other hand, other associated attributes with the destroyed or deleted MHEG entity are completely removed without changing their status values. For example, if there is an rt-component which running status is “running”, its running status is removed without changing value. That means the rt-component has been deleted while it was “running”. The running status is no more available after deletion. If there is a link which condition is “when the running status becomes “not running””, it shall not be triggered at the time of the deletion.
+
+## 31 General action mechanisms
+
+This clause summarises the general action mechanisms and its treatment to be processed by the MHEG engine. This mechanism is applied for all other behaviours processing as well as common behaviours processing.
+
+### 31.1 Action treatment
+
+Actions are to be processed satisfying following conditions:
+
+- If an MHEG effect of an action contains a list of subeffects, these subeffects are to be performed by the MHEG engine as if they were a single uninterruptable and indivisible operation.
+- The effect of processing an action on a set of two or more targets is to propagate the action to each target within the set of targets. These actions are processed in parallel. The MHEG effect of the action ends when the MHEG effects of all propagated actions end.
+- In certain cases, in order to process an action, a proceeding action is implicitly executed. This proceeding action may produce a change of status. A link triggered on this change of status is fired before the processing of the specified action ends.
+
+For example, when an rt-object is made from a model object which is not prepared, this Recommendation specifies that an implicit Prepare action is to be targeted to the model object before the New action. A link whose condition is “when a preparation status of the model becomes ready” is to be triggered when the model object enters in O2, and not when the rt-object enters R2.
+
+## 31.2 Processing of link effect
+
+When the link is fired, i.e. the link is activated and the link condition is satisfied, the MHEG engine processes the link effect. Each time the link is fired, the link effect is processed in two phases as follows:
+
+- The macro resolution phase: If some macros are in this link (see clause 13).
+- The action process phase: It consists on processing the action object included or referenced in the link effect. This action object may be a basic action, a nested action or a macro action.
+
+The link effect is processed as summarised in Figure 45.
+
+The action process begins when the link condition is satisfied and the macro resolution accomplished, when the action is a macro action. Each action object is a recursive construction containing a group of synchronised actions accompanied by a synchro indicator.
+
+The synchro indicator specifies if the synchronised actions in the group are to be processed in parallel or in serial. The action group process depends on the synchro indicator. If a synchro indicator attribute is specified as a macro and if this macro is resolved as the value “undefined”, the entire synchronised action set is not processed.
+
+```
+BEGIN ACTION PROCESS of action object within the link effect
+  IF synchro indicator == serial
+    FOR J = 1 TO number_of_synchronised_actions
+      DO
+        IF synchronised_action J == elementary_action
+          PERFORM target resolution of elementary_action J
+          PERFORM the action effect of elementary_action J on the target set
+        ELSE IF synchronised_action J == action_object
+          PERFORM RECURSIVE ACTION PROCESS of action_object J
+        ENDIF
+        WAIT FOR the end of MHEG effect of synchronised_action J
+      ELSE IF synchro_indicator == parallel
+        FOR J = 1 TO number_of_synchronised_actions
+          DO SIMULTANEOUSLY
+            IF synchronised_action J == elementary_action
+              PERFORM target resolution of elementary_action J
+              PERFORM the action effect of elementary_action J on the target set
+            ELSE IF synchronised_action J == action_object
+              PERFORM RECURSIVE ACTION PROCESS on action_object J
+            ENDIF
+          ENDIF
+        ENDIF
+        WAIT FOR the end of MHEG effect of each action in each "synchronised actions"
+        WAIT FOR the end of user effect of each action 'run' in each "synchronised actions"
+        DURING that time IF a target is "running" AND
+          IF its current temporal position == its terminal temporal position
+            PERFORM a Stop action on this target
+      END OF ACTION PROCESS of action object within the link effect
+```
+
+**Figure 45/T.171 – Action process phase**
+
+### 31.2.1 Serial action processing
+
+If all the elementary actions contained in a serial action group are specified to be processed, each elementary action is processed sequentially after the MHEG effect of the previous elementary action is completed.
+
+Figure 46 shows an example. In this figure, 2 elementary actions are included in a link effect. After finishing the MHEG effect of elementary action 1, elementary action 2 is processed.
+
+The duration of the MHEG effect for a serial action list is the sum of duration of the MHEG effects for the serial actions.
+
+If a Run action is contained within the group, the user effect of the Run action continues even after the MHEG effects of the group are completed, except if a Stop action is performed.
+
+![Timeline diagram for serial actions. A horizontal axis labeled 't' shows two sequential shaded rectangular blocks. The first is labeled 'MHEG effect of elementary action 1' and the second 'MHEG effect of elementary action 2'. Above this is a box representing the 'Synchronised action group' with a serial synchro indicator listing both actions in order.](c93c4b33a2b42c8dd6d82a354f2f89f1_img.jpg)
+
+Synchronised action group
+
+Synchro indicator: serial  
+- elementary action 1  
+- elementary action 2
+
+```
+
+graph LR
+    subgraph Serial_Group [Synchronised action group - Serial]
+    A1[elementary action 1] --> A2[elementary action 2]
+    end
+
+```
+
+T0825910-96/d044
+
+Timeline diagram for serial actions. A horizontal axis labeled 't' shows two sequential shaded rectangular blocks. The first is labeled 'MHEG effect of elementary action 1' and the second 'MHEG effect of elementary action 2'. Above this is a box representing the 'Synchronised action group' with a serial synchro indicator listing both actions in order.
+
+**Figure 46/T.171 – Example of processing of serial actions**
+
+### 31.2.2 Parallel action processing
+
+If all the elementary actions contained in a parallel action group are specified to be processed, each elementary action is processed simultaneously. The MHEG effect of the parallel action group ends when the MHEG effects of all the parallel actions end.
+
+When a parallel group is imbricated in a serial group, the MHEG engine is required to wait for the end of the MHEG effect of the set of parallel actions before processing the next action in the serial group.
+
+Figure 47 shows an example of parallel processing. Before processing the elementary action 4, the MHEG engine waits for the end of the MHEG effect of the action group, i.e. the end of the MHEG effect of elementary action 2.
+
+The duration of the MHEG effect for a set of parallel actions is the longest MHEG effect among the parallel actions.
+
+![Timeline diagram for nested parallel actions. A horizontal axis 't' shows: 1. 'MHEG effect of elementary action 1'. 2. A parallel block where 'MHEG effect of elementary action 2' and 'MHEG effect of elementary action 3' start simultaneously; action 3 is longer. 3. 'MHEG effect of elementary action 4' starts only after action 3 ends. Above is a nested box structure showing the serial group containing action 1, a parallel action group (actions 2 & 3), and action 4.](aa22da43c463563d3d0035722bd79449_img.jpg)
+
+Synchronised action group
+
+Synchro indicator: serial  
+– elementary action 1  
+– action group  
+
+Synchro indicator: parallel  
+– elementary action 2  
+– elementary action 3
+
+– elementary action 4
+
+```
+
+graph TD
+    subgraph Serial_Group [Synchronised action group - Serial]
+    A1[elementary action 1] --> P_Group
+    subgraph P_Group [Action Group - Parallel]
+    A2[elementary action 2]
+    A3[elementary action 3]
+    end
+    P_Group --> A4[elementary action 4]
+    end
+
+```
+
+T0825920-96/d045
+
+Timeline diagram for nested parallel actions. A horizontal axis 't' shows: 1. 'MHEG effect of elementary action 1'. 2. A parallel block where 'MHEG effect of elementary action 2' and 'MHEG effect of elementary action 3' start simultaneously; action 3 is longer. 3. 'MHEG effect of elementary action 4' starts only after action 3 ends. Above is a nested box structure showing the serial group containing action 1, a parallel action group (actions 2 & 3), and action 4.
+
+**Figure 47/T.171 – Example of processing parallel actions**
+
+### 31.3 Basic processing of an elementary action
+
+When the MHEG engine processes an elementary action on a single target, the following effects are obtained:
+
+- **MHEG effect without transition duration:** This begins at the instance when the action is targeted, and it ends when the action has been taken into account by the MHEG engine. This typically results in a change of status or behaviour attribute value. See some examples in Figures 30, 32, 34, 36, 38, 40 and 44.
+- **User effect without transition duration:** This effect exists only if the running status is “running”. This effect begins at the instance when the MHEG effect of the Run action ends. This user effect lasts until the MHEG effect of the Stop action ends. The user effect is perceptible by the user during the “running”. Each time a presentation attribute of the target is changed, if the target is “running”, the user effect immediately reflects this change. See some examples in Figures 38 and 40.
+- **MHEG Effect with transition duration:** This begins at the instance when an action specifying a non-null transition duration is targeted to an entity. It ends when the action has been taken into account by the MHEG engine. If the target is not running, the transition duration is set to zero and ignored. See some examples in Figures 41, 42 and 43.
+- **User Effect with transition duration:** This effect exists only when a target is running and a set action with a non-null transition duration is targeted to it. This effect begins at the instance when the MHEG effect of the transition duration begins. The effect of the action is perceptible to the user gradually from the previous value to the specified value. Once the MHEG effect of the transition duration ends, the user effect with transition duration ends. See examples in Figures 41, 42 and 43.
+
+### 31.4 Resolution of target set
+
+A single target (e.g. an MHEG object, a container element, an rt-object, a socket element, a channel) or multiple targets (e.g. some targets, an alias addressing several entities, all the rt-objects made from a model object, all the children of a specified entity) may be specified for each elementary action. Multiple targets are specified as a list of targets. The action effect for each target within a list should be processed in parallel.
+
+#### NOTES
+
+- 1 – Authors should not rely on the order in which the parallel actions are executed.
+- 2 – An MHEG engine is not required to perform true parallel processing.
+
+Processing an action on an undefined target has no effect.
+
+### 31.5 Arithmetic precision
+
+Percentage and ratio may be specified in some of elementary actions’ parameters, for example, Set GTF, Set OVD. And ratio is also used in mapping OPS to RPS.
+
+The general rule to calculate percentage and ratio is that full precision operation should be taken up to the final presentation of objects. Rounding should be done only for the final presentation of objects, i.e. in the final chain of OPS to CPS at channels.
+
+#### NOTES
+
+- 1 – If an rt-object with CV 17 is connected to rt-composite A with GVF 1/3 that is connected to rt-composit B with GTF 3 and rt-composite B is connected to a channel, the final volume to be mapped to a physical device is 17 (Round( $17 \times 1/3 \times 3$ )) and not 18 (Round(Round( $17 \times 1/3$ )  $\times 3$ )).
+- 2 – In above example with changing GTF of rt-composite B to 2, the final volume is 11 (Round( $17 \times 1/3 \times 2$ )).
+- 3 – A profile of this Recommendation or a using application may define another arithmetic precision and rounding policies.
+
+## 32 Common action effects and handling
+
+This clause describes common action effects and handling for all elementary actions and get actions applied for all behaviours throughout this Recommendation. The actual process of elementary actions and get actions is outside the scope of this Recommendation, and should be provided by the MHEG engine.
+
+### 32.1 Elementary actions
+
+Common action effects and handling to all elementary actions are as follows:
+
+- If the MHEG engine is unable to perform the required MHEG effect of an elementary action, it is recommended, but not required, that the MHEG engine notify the using application of it.
+- If the effect of targeting an elementary action to an MHEG object, an rt-object or a channel is not described in this Recommendation, this action is ignored by the MHEG engine.
+- If the whole set of targets becomes no more available during the processing of an elementary action (i.e. all the targets within the set are destroyed or deleted), the process of this action is aborted.
+- If a reference to a target of an elementary action except for Prepare, Activate, New and New Channel actions is invalid, the elementary action is ignored (i.e. with a null effect and completed immediately).
+- If a target within a set of targets for an elementary action does not exist, this action is ignored only for that target.
+- If the reference specification defines an empty set of MHEG objects, rt-objects or channels, the reference is ignored.
+- If the reference is ignored, the MHEG engine behaves as if no entity is addressed.
+- If a Prepare, New or New Channel action is applied to an MHEG entity which has an identifier already assigned to an MHEG entity currently available to the MHEG engine, that action is ignored.
+- If an elementary action is targeted to an rt-object in period R2 with a transition duration parameter, the specified transition parameter value is ignored and the elementary action is performed as if the transition duration is set to 0.
+- If an elementary action is targeted to an rt-object in period R3 with a transition duration parameter, the specified transition parameter value is interpreted by the GTU assigned for the target. The presentation of the target is being gradually changed depending on the elementary action and changing presentation attribute.
+- If a transition duration parameter is specified as a negative value, it is set to 0.
+- This Recommendation does not define the behaviour of the MHEG engine that is executing a sequential synchronised actions group while one or more actions fail.
+
+If some user effect is associated with an elementary action, it is explained in the corresponding clause of the elementary action. If there is nothing about the user effect explained in the clause, no user effect is associated with the elementary action.
+
+### 32.2 Get actions
+
+Common action effects and handling to all get actions are as follows:
+
+- If a reference to a target of a get action except for Get Preparation Status, Get Activation Status, Get Rt-availability Status and Get Channel Availability actions is invalid, the result is to be evaluated to “undefined”.
+- If an MHEG engine is unable to evaluate a get action, this action is evaluated to “undefined”.
+- If a reference to multiple entities (e.g. children tail, descendant tail) is specified, this reference is ignored. The target of a get action needs to address a single entity.
+- If the reference is ignored, the MHEG engine behaves as if no entity is addressed.
+
+### 32.3 Recommended exception handling
+
+This Recommendation does not define any exception handling within the MHEG engine, but recommends following treatments on some situations:
+
+- 1) If an object whose encoding does not conform to this Recommendation is provided to the MHEG engine, ignoring the whole object is recommended.
+- 2) If non-existing entities are referenced except for targets of elementary actions and get actions, following are recommended depending on the invalid reference:
+  - a) in a link condition, respective conditions are evaluated to “undefined”;
+  - b) otherwise (e.g. in a composition element), they are replaced by null objects.
+
+These replacement behaviours are withdrawn as soon as the referenced object comes into existence.
+
+- 3) If an object receives an action for which the corresponding behaviour is not defined by this Recommendation, ignoring this action is recommended. For example, Delete action targeted to a content object, a Set action with an unsupported value targeted to an rt-object.
+
+The behaviour may be defined in an extension to this Recommendation defined by another standard or a using application.
+
+- 4) If other exceptions, e.g. request for a presentation aspect not supported by the presentation environment, or runtime failures like insufficient memory, happen, graceful degradation and sensible fall backs are encouraged.
+
+## 33 Postpone Behaviour
+
+This behaviour postpones the process of any actions. Initially, each action is processed immediately. However, using this facility, any action may be postponed.
+
+### 33.1 Behaviour attributes and statuses
+
+None.
+
+### 33.2 Actions to change the behaviour
+
+This Recommendation defines means to modify this behaviour by the use of the following action:
+
+- Delay action (see 33.2.1).
+
+#### 33.2.1 Delay action
+
+This action inserts a delay between two actions of a serial synchronised action set within an action object.
+
+This action has the following parameters:
+
+- Temporal Unit Ref Param;
+- Duration Param.
+
+This action may be targeted during any period.
+
+##### 33.2.1.1 Delay action effect
+
+The MHEG effect is as follows:
+
+- 1) If the temporal unit reference is specified as an rt-component, the duration of the delay is expressed in OGTU belonging to the rt-component.
+
+When the temporal unit reference indicates an rt-content, the delay is interpreted following the rules of the OPS-RPS-CPS chain exactly like any other temporal attributes.
+- 2) Otherwise (the temporal unit reference is specified as default GF), the duration of the delay is expressed in PTU.
+- 3) If the Delay action is in serial synchronised actions, the MHEG engine waits during the specified duration before processing the next action.
+- 4) The MHEG effect ends when the duration of the delay is expired.
+
+#### **33.2.1.2 Delay additional error conditions**
+
+- if the Duration Parameter parameter value is a negative value, it is set to the value 0;
+- if the specified rt-component does not exist, the retrieved GTF is interpreted as the default-GF.
+
+### **34 Returnability Behaviour**
+
+This behaviour returns information to a using application or external entities outside of the MHEG engine, e.g. a script engine, a GUI, a server.
+
+#### **34.1 Behaviour attributes and statuses**
+
+None.
+
+#### **34.2 Actions to change the behaviour**
+
+This Recommendation defines means to modify this behaviour by the use of the following action:
+
+- Return action (see 34.2.1).
+
+##### **34.2.1 Return action**
+
+This action enables to return information to a using application or external entities outside of the MHEG engine. Generic values or information contained in content objects may be passed.
+
+This action has the following parameters:
+
+- Set of Return Target Param;
+- Return Indicator Param;
+- Set of Returned Generic Value Param;
+- Set of Content Object Ref Param.
+
+This action may be targeted during any period.
+
+##### **34.2.1.1 Return action effect**
+
+The MHEG effect of the Return action is as follows:
+
+Return Indicator Param, Returned Generic Value Param and Content Object Ref Param are passed to the entity specified by the Return Target Parameters. The encoding format of the returned information is not defined by this Recommendation.
+
+##### **34.2.1.2 Return additional error conditions**
+
+None.
+
+### **35 Alias Behaviour**
+
+This behaviour provides a symbolic identification to any generic references. Initially, no alias is given to any references.
+
+#### **35.1 Behaviour attributes and statuses**
+
+None.
+
+#### **35.2 Actions to change the behaviour**
+
+This Recommendation defines means to modify this behaviour by the use of the following actions:
+
+- Set Alias action (see 35.2.1).
+
+### 35.2.1 Set Alias action
+
+This action enables the assignment of aliases to any generic references.
+
+This action has the following parameters:
+
+- Set of Target Param;
+- Set of Alias Spec Param.
+
+This action may be targeted during any period.
+
+#### 35.2.1.1 Set Alias action effect
+
+This effect of this action is as follows:
+
+- 1) according to the Update Command, one or several aliases are added, removed or replaced to a target;
+- 2) if a target is not accessible at the moment of this action, the alias is assigned to the reference as if the target were accessible.
+
+#### 35.2.1.2 Set Alias additional error conditions
+
+None.
+
+## 36 Extensibility Behaviour
+
+This behaviour allows the process of a catalogued elementary action, or the modification or retrieval of a catalogued attribute value (see clause 15).
+
+The main purpose of the catalogued elementary actions is to provide the behaviour that cannot be sensibly controlled like attributes, e.g. draw line, perform some arithmetic operations or stop the MHEG engine.
+
+On the other hand, the main purpose of the catalogued attributes is to deal with the information that can be expressed by attributes, e.g. presentation attributes like font size or channel attributes like current number of assigned rt-components.
+
+The author should distinguish the differences.
+
+Style behaviour is also a kind of extension that is devoted for presentation and interaction. For example, content format (encoding data) conversion is a feature of catalogued elementary actions, while presenting a content in different ways is a feature of the style behaviour (a music code playing in a graphical way or audible way).
+
+### 36.1 Behaviour attributes and statuses
+
+This behaviour is expressed using the following attribute or status:
+
+- Catalogued Attribute (see 36.2).
+
+### 36.2 Catalogued Attribute
+
+A catalogue entry which represents the list of informations that can be, for instance, presentation attributes, font size or channel attributes. The catalogued attribute may be used as a kind of tail to navigate into the hierarchy of the catalogues.
+
+### 36.3 Actions to change the behaviour
+
+This Recommendation defines means to modify this behaviour by the use of the following actions:
+
+- Catalogued Elementary Action action (see 36.3.1);
+- Set Catalogued Attribute action (see 36.3.2).
+
+### **36.3.1 Catalogued Elementary Action action**
+
+This action enables to use an extended elementary action which is registered or proprietary.
+
+This action has the following parameters:
+
+- Set of Target Param;
+- Catalogued Extended EA Param;
+- Set of Elementary Action Param.
+
+This period is described in the catalogue where the extended EA is retrieved.
+
+#### **36.3.1.1 Catalogued Elementary action effect**
+
+The effect of this action is described in the catalogue where the extended elementary action is retrieved.
+
+#### **36.3.1.2 Catalogued Elementary Action additional error conditions**
+
+- The additional errors are also described in the catalogue where the extended elementary action is retrieved.
+
+### **36.3.2 Set Catalogued Attribute action**
+
+This action enables to set a value of a catalogued attribute for the target.
+
+This action has the following parameters:
+
+- Set of Target Param.
+- Cat Ext Attribute Param.
+- Ext Attribute Value Param: A generic value to be assigned to a Cat Ext Attribute.
+- Transition Duration Param: A generic value to be assigned to a Cat Ext Attribute.
+
+This period is described in the catalogue where the extended EA is retrieved.
+
+#### **36.3.2.1 Set Catalogued Attribute action effect**
+
+The action effect depends on the chosen attributes and is described in the corresponding catalogue.
+
+#### **36.3.2.2 Set Catalogued Attribute additional error conditions**
+
+- The additional errors are also described in the catalogue where the extended elementary action is retrieved.
+
+## **36.4 Actions to retrieve the behaviour**
+
+This Recommendation defines means to get this behaviour by the use of the following action:
+
+- Get Catalogued Attribute action (see 36.4.1).
+
+### **36.4.1 Get Catalogued Attribute action**
+
+This action enables to retrieve a value of a catalogued attribute for the target.
+
+This action has the following parameters:
+
+- Target Param.
+- Cat Ext Attribute Param: A generic value to be assigned to a Cat Ext Attribute.
+
+This period is described in the catalogue where the extended EA is retrieved.
+
+#### **36.4.1.1 Get Catalogued Attribute action effect**
+
+The value of the catalogued attribute is retrieved.
+
+#### **36.4.1.2 Get Catalogued Attribute additional error conditions**
+
+- The additional errors are also described in the catalogue where the extended elementary action is retrieved.
+
+## SECTION 5 – MHEG OBJECTS BEHAVIOUR
+
+### 37 MHEG Objects Availability Behaviour
+
+The behaviour is used to express the availability of an MHEG object to the MHEG engine. This behaviour is common for all MHEG objects.
+
+#### 37.1 Behaviour attributes and statuses
+
+This behaviour is expressed using the following attribute or status:
+
+- Preparation Status (see 37.2).
+
+#### 37.2 Preparation Status
+
+The availability of each MHEG object to the MHEG engine may be evaluated. The result of this evaluation is set in the preparation status. The following applies (see Figure 31).
+
+- 1) When an MHEG object is not available to the MHEG engine, its preparation status is evaluated to “not ready”, i.e. the MHEG object is in period O1. Initially an MHEG object is in that state.
+
+NOTE 1 – For example, in that state, the object has not been interchanged to the receiving system, some pre-processing is required to prepare an object for presentation, etc.
+
+- 2) Otherwise, its preparation status is evaluated to “ready”, i.e. the MHEG object is in period O2.
+
+NOTE 2 – An MHEG engine may offer to the using application more detailed diagnostic and information messages, for example, to explain that an object cannot be located, or to indicate error conditions. These messages are not defined by this Recommendation but may be the subject of other standards.
+
+#### 37.3 Actions to change the behaviour
+
+This Recommendation defines means to modify this behaviour by the use of the following actions:
+
+- Prepare action (see 37.3.1);
+- Destroy action (see 37.3.2).
+
+##### 37.3.1 Prepare action
+
+This action makes the MHEG object available to the MHEG engine.
+
+###### NOTES
+
+1 – For example, retrieval of an audiovisual sequence from a disk may require so much time that it may be efficient to start loading it before it is needed.
+
+2 – A using application or a specific profile shall define one concrete behaviour of this action. For example, considering a content object which has large data may be loaded either within the Prepare MHEG effect or outside of it, depending on the adapted strategy.
+
+This action has the following parameter:
+
+- Set of MH-Target Param.
+
+This action may be targeted during the period O1.
+
+##### 37.3.1.1 Prepare action effect
+
+If the preparation status of the target is “not ready”, the following applies:
+
+- 1) Make the target available to the MHEG engine.
+- 2) Process the specific effects of the Prepare action on the following targets:
+  - a) Action object: Implicit Prepare actions are targeted to the embedded (included or referenced) action objects in a nested action object.
+  - b) Link object: Implicit Prepare actions are targeted to the action objects (included or referenced) describing the link effect.
+
+The preparation of a link object does not imply the preparation of any targets of the get actions and elementary actions considered in this link.
+
+- c) Script object: The script data (included or referenced) is made available to the MHEG engine.
+
+Object availability to an MHEG engine is not defined by this Recommendation. For example, the script data may be compiled into executable code and linked to the MHEG engine or it may be in an interpreted form requiring a separate process.
+
+- d) Content object: The content data (included or referenced) is made available to the MHEG engine.
+
+Object availability to an MHEG engine is not defined by this Recommendation. For example, the content data may be in the memory of the MHEG engine or available when required via a telecom or broadcast network.
+
+- e) Composite object:
+
+- i) Composite Prepare actions are targeted to the links and action objects included in the specific behaviour.
+- ii) Implicit Prepare actions are targeted to the associated model objects included in the composition elements.
+- iii) Implicit Activate actions are targeted to the “availability start-up”, “rt-availability start-up”, “availability close-down” and “rt-availability close-down” links.
+
+- 3) NOTE 1 – The object designer may specify an explicit preparation and activation of the link and action objects only when there is a need to include that behaviour in the MHEG engine, or in order to take into account the needs of minimal resource systems.
+
+- 4) NOTE 2 – The object designer may specify an explicit preparation of the referenced associated model objects only when there is a need to create an rt-composite. This takes into account the needs of minimal resource systems:
+
+- a) Container object: Implicit Activate actions are targeted to the “container start-up” and “container close-down” links.
+
+The object designer may specify, within these links, an explicit sequencing of preparation of the objects, and so make these objects available to the MHEG engine when needed, in order to take into account the needs of minimal resource systems.
+
+- b) Descriptor object: The descriptor information (included or referenced) is made available to the MHEG engine.
+
+It is expected that the MHEG engine evaluates the information provided by the descriptor during the execution of the Prepare action. It depends on the implementation of the engine and the execution context how the information is handled.
+
+- 5) Set the preparation status of the target to “ready”. The target enters in period O2. These additional effects are to be processed on the following targets:
+
+- a) Content object: The following behaviours are available:
+
+- i) Generic value storage behaviour;
+- ii) Copy behaviour (see 72.9.1).
+
+- b) Composite object: “Availability start-up” is fired, i.e. its link effect is processed.
+
+- c) Container object: “Container start-up” is fired, i.e. its link effect is processed.
+
+### 37.3.1.2 Prepare additional error conditions
+
+- If one of the targets is an indexed element within a container object, the outer container object needs to be prepared. If it is not prepared, the action is ignored for that target.
+- If one of the targets is not an MHEG object in O1, this action is ignored for that target.
+
+### 37.3.2 Destroy action
+
+This action removes an MHEG object from the MHEG engine in order to release resources (e.g. memory, bandwidth, processing power) in the MHEG engine.
+
+This action has the following parameter:
+
+- Set of MH-Target Param.
+
+This action may be targeted during the period O2.
+
+#### 37.3.2.1 Destroy action effect
+
+If the preparation status of the target is “ready”, the following applies:
+
+- 1) Process the specified effects of the Destroy action on the following targets:
+  - a) Action object:
+    - i) Implicit Destroy actions are targeted to the embedded (included or referenced) action objects in a nested action object.
+
+NOTE 1 – Object designers should be aware of side effects that may occur if these objects are referenced in other objects.
+    - ii) If an action object to be destroyed is under processing, the processing is interrupted.
+
+The way in which the processing is interrupted is not defined by this Recommendation. It is the responsibility of the MHEG engine.
+    - iii) If a nested action object is destroyed in an action object, this nested action object is replaced by a null object.
+
+NOTE 2 –Processing a null object has a null effect.
+  - b) Link object:
+    - i) If the link effect of the target is under process, an implicit Link Abort action is targeted to the link.
+
+As a link may be fired several times during its life, several link effects may be under process at the same time. All of these link effects are concerned.
+    - ii) An implicit Destroy action is targeted to each included or referenced action object.
+
+NOTE 3 – Object designers should be aware of side effects that may occur if this action object is referenced in other objects.
+
+NOTE 4 – The destruction of a link does not imply the destruction of any target for that link.
+  - c) Model object: Implicit Delete action is targeted to all the existing rt-objects created from this model object. The rt-availability status for each rt-object is changed to “not available”. Other behaviours are destroyed.
+
+NOTE 5 – Object designers should be aware that the rt-objects disappear if the original model object is destroyed.
+
+NOTE 6 – It is not defined by this Recommendation how to handle the disappearance of the rt-objects. It is left to the MHEG engine.
+  - d) Script object: The script data (included or referenced) is destroyed.
+
+Object designers should be aware of side effects that may occur if this script data is referenced in another script object.
+  - e) Content object: The content data (included or referenced) is destroyed.
+
+Object designers should be aware of side effects that may occur if this content object data is referenced in another content object.
+  - f) Composite object:
+    - i) Implicit Destroy actions are targeted to the “availability start-up”, “rt-availability start-up” and “rt-availability close-down”;
+    - ii) Implicit Destroy actions are targeted to the links and action objects included in the specific behaviour;
+
+- iii) Implicit Destroy actions are targeted to the included component objects associated with the composition elements;
+  - iv) Associated model objects and labels are also destroyed.
+- g) Container object: An implicit Destroy action is targeted to the “availability start-up” link.
+- 2) Set the preparation status of the target to “not ready”. The target enters in period O1. These additional effects are to be processed on the following targets:
+  - a) Link object: The activation behaviour is changed to “inactivate”.
+  - b) Model object: The rt-availability behaviour is changed to “not available”.
+  - c) Composite object: availability close-down link is fired, i.e. its link effect is processed. After the link effect, availability close-down link is destroyed.
+  - d) Container object: Availability close-down link is fired, i.e. its link effect is processed. After the link effect, availability close-down link is destroyed.
+- 3) Destroy the target.
+
+#### **37.3.2.2 Destroy additional error conditions**
+
+- If one of the targets is not an MHEG object in O2, this action is ignored for that target.
+
+### **37.4 Actions to retrieve the behaviour**
+
+This Recommendation defines means to get this behaviour by the use of the following actions:
+
+- Get Preparation Status action (see 37.4.1).
+
+#### **37.4.1 Get Preparation Status action**
+
+This action gets the preparation status of each MHEG object.
+
+This action has the following parameter:
+
+- MH-Target Param.
+
+This action may be targeted during the periods O1 and O2.
+
+##### **37.4.1.1 MHEG effect**
+
+This action evaluates the preparation status of the target. Following applies:
+
+- 1) if the target is in period O1, the preparation status is evaluated to “not ready”;
+- 2) otherwise (i.e. the target is in period O2), the preparation status is evaluated to “ready”.
+
+##### **37.4.1.2 Get Preparation Status additional error conditions**
+
+None.
+
+## **38 Link Object Activation Behaviour**
+
+This behaviour controls the processing of a link object in the MHEG engine. All link objects have this behaviour. Active link objects are surveyed by the MHEG engine. Whenever a link condition becomes true, the corresponding link effect is performed.
+
+### **38.1 Behaviour attributes and statuses**
+
+This behaviour is expressed using the following attribute or status:
+
+- Activation Status (see 38.2).
+
+## 38.2 Activation Status
+
+After preparing, the activity of each link object to the MHEG engine may be evaluated. The result of this evaluation is set in the activation status.
+
+When a link object is allowed to be fired, its activation status is set to “activate”, i.e. the link object is in period L2.
+
+Otherwise, its activation status is set to “inactive”, i.e. the link object is in period L1.
+
+## 38.3 Actions to change the behaviour
+
+This Recommendation defines means to modify this behaviour by the use of the following actions:
+
+- Activate action (see 38.3.1);
+- Deactivate action (see 38.3.2).
+
+### 38.3.1 Activate action
+
+This action activates link objects, i.e. they may be fired.
+
+This action has the following parameter:
+
+- Set of Link Target Param.
+
+This action may be targeted during the period L1.
+
+#### 38.3.1.1 Activate action targeted to a single link object
+
+The MHEG effect of this action is as follows:
+
+- If the target is in period O2/L1, the activation status of the target is set to “active”.
+- If the target is in period O1, an implicit Prepare action is targeted to this target. After preparing, the activation status of the target is set to “active”.
+
+A link object may be fired only if its preparation status is “ready” and its activation status is “active”, i.e. the link object is in period O2/L2. Once active, the link effect may be processed several times (i.e. each time the link condition becomes true) until the link object is set to “inactive”.
+
+#### 38.3.1.2 Activate additional error conditions
+
+- If one of the targets is not a link object in O1 O2/L1, this action is ignored for that target.
+
+### 38.3.2 Deactivate action
+
+This action deactivates link objects, i.e. they cannot be fired.
+
+This action has the following parameter:
+
+- Set of Link Target Param.
+
+This action may be targeted during the period L2.
+
+#### 38.3.2.1 Deactivate action effect
+
+The MHEG effect of this action is as follows:
+
+- If the target is in period L2, the activation status of the target is set to “inactive”.
+
+#### 38.3.2.2 Deactivate additional error conditions
+
+- If one of the targets is not a link object in L2, this action is ignored for that target.
+
+## 38.4 Actions to retrieve the behaviour
+
+This Recommendation defines means to get this behaviour by the use of the following action:
+
+- Get Activation Status action (see 38.4.1).
+
+### 38.4.1 Get Activation Status action
+
+This action retrieves the activation status value of a link object.
+
+This action has the following parameter:
+
+- Link Target Param.
+
+This action may be targeted during the periods L1 and L2.
+
+#### 38.4.1.1 Get activation status targeted to a link object
+
+The MHEG effect of this action is to retrieve the activation status of the target. The following applies:
+
+- 1) if the target is in period L1, the activation status evaluates to “inactive”;
+- 2) if the target is in period L2, the activation status evaluates to “active”.
+
+#### 38.4.1.2 Get Activation Status additional error conditions
+
+- the target addresses multiple entities, e.g. use of an alias which addresses a list of targets, or use of the “\*” wildcard instead of a given rt-component number, or use of children or descendants tails, the action is ignored for that target;
+- if the target is not a link object, this action is ignored for that target;
+- if the target is not accessible, e.g. the reference cannot be solved, the action is ignored for that target.
+
+## 39 Link Object Abort Behaviour
+
+This behaviour aborts the processing of all the actions that are contained in a link object.
+
+### 39.1 Behaviour attributes and statuses
+
+None.
+
+### 39.2 Actions to change the behaviour
+
+This Recommendation defines means to modify this behaviour by the use of the following action:
+
+- Link Abort action (see 39.2.1).
+
+#### 39.2.1 Link Abort action
+
+This action aborts the processing of all the actions contained in a link object.
+
+This action has the following parameter:
+
+- Set of Link Target Param.
+
+This action may be targeted during the period L2.
+
+##### 39.2.1.1 Link Abort action effect
+
+The effect of the action is as follows:
+
+- 1) The elementary actions currently processed within the link effect of the target are aborted. These elementary actions are directly contained in the link effect or in a nested action object. The rest of the elementary actions contained within the link effect or some nested action objects are not processed.
+- 2) If the aborted elementary action is processing the MHEG effect changing an attribute value, the following applies:
+  - a) If it is without a transition duration, the value is not changed.
+  - b) Otherwise (with a transition duration), the value becomes the current changing value.
+
+What is aborted is the process of the transition duration. That is why the presentation attribute value on which the changing with transition duration is under processing stops its changing at its current value. This is a different effect from a Stop action targeted during that time (see Figure 42).
+
+- 3) If the aborted elementary action is a Run action, an implicit Stop action is targeted to the same target of the Run action.
+
+If the aborted elementary action has a set of targets, the effect depends on the processing state of this elementary action on each target.
+
+#### NOTES
+
+1 – Suppose one Prepare action is targeted to both Object A and Object B within the link L1, and the MHEG effect of the Prepare action for Object A is already terminated (i.e. Object A is in period O2), but the MHEG effect of that for Object B is still under processing (i.e. Object B is in period O1). In this case, if a Link Abort action is targeted to L1, the preparation status of Object A is evaluated as “ready”, however, that of Object B is “not ready”.
+
+2 – A Link Abort action does not affect a link activation status. A link can fire even if a Link Abort action targeted to it is being processed. Only the actions originated by a link before the Link Abort action is targeted to such link are affected by the Link Abort action.
+
+3 – It is advised to limit the use of Link Abort actions as much as possible. Its main role is to terminate the processing of actions that are performing MHEG effects with transition durations in R3.TD.
+
+#### 39.2.1.2 Link Abort additional error conditions
+
+- If one of the targets is not a link object in L2, this action is ignored for that target.
+
+## 40 Content Class Generic Value Storage Behaviour
+
+This behaviour is of storage and retrieval of a generic value within the data of a content object.
+
+### 40.1 Behaviour attributes and statuses
+
+This behaviour is expressed using the following attribute or status:
+
+- Data (see 40.2).
+
+### 40.2 Data
+
+A generic value may be stored in a content object and may be retrieved from a content object for further processing. By using the generic value storage behaviour, a content object may be used as a variable holder.
+
+### 40.3 Actions to change the behaviour
+
+This Recommendation defines means to modify this behaviour by the use of the following actions:
+
+- Set Data action (see 40.3.1);
+- Add action (see 40.3.2);
+- Subtract action (see 40.3.3).
+
+#### 40.3.1 Set Data action
+
+This action enables to store or to modify a generic value in the data field of a content object.
+
+This action has the following parameters:
+
+- Set of Content Target Param;
+- Substitution Indicator Param;
+- Set of Data Element Param.
+
+This action may be targeted during the period O2.
+
+#### 40.3.1.1 Set Data targeted to a single content object
+
+If a set of data element parameters is provided, the elements in this set are interpreted sequentially. For each data element parameter, the following effect applies:
+
+- 1) If the generic list element ID parameter is omitted:
+  - a) And if the substitution indicator parameter is equal to “substitution”, the previously stored generic value is totally substituted by the specified generic value (see Figure 48).
+  - b) Otherwise (substitution indicator parameter is “no substitution”):
+    - i) If the target contains a generic list, the specified generic value is added as a new element of the generic list in the target. If the target contains n elements, the new value is indexed as n + 1th element (see Figure 49).
+    - ii) Otherwise, this action is ignored.
+- 2) Otherwise (generic list element ID parameter is specified):
+  - a) If the target does not store a generic list:
+    - i) If the substitution indicator parameter is “substitution”, the previously stored value is discarded and new generic list is to be created. The specified generic value is stored in the specified generic list element ID, and other elements until the last path numeric in the specified generic list element ID should be filled with “unspecified” (see Figure 50).
+    - ii) Otherwise, this action is ignored.
+  - b) Otherwise (the target is a generic list):
+    - i) If the specified generic list element ID exists in the target:
+      - If the substitution indicator is “substitution”, the specified generic value is stored in the specified element ID, overwriting the previous value (see Figure 51).
+      - Otherwise (the substitution indicator is “no substitution”), this action is ignored.
+    - ii) If the specified generic list element ID does not exist in the target and it is possible to extend generic list element ID as specified, the generic list of the target is extended in order to store the specified generic value. Empty elements created by this extension are filled with “unspecified”. In this case, the substitution indicator is ignored (see Figure 52).
+    - iii) Otherwise (the specified generic list element ID does not exist and it is impossible to extend), this action is ignored (see Figure 53).
+
+The order of the data element parameters is important, especially if no generic list element ID is specified for the generic value with “no substitution” and the target has a generic list.
+
+#### 40.3.1.2 Set Data additional error conditions
+
+- if one of the targets is not a content object in O2, this action is ignored for that target;
+- if the hook of the targeted content object does not specify generic value, this action is ignored;
+- if a set data contains an element value which is specified as a Get Data action applied to the same target content object, this element value is replaced by an “unspecified” value;
+- if the target is not a non-mux content, this action is ignored for that target.
+
+![Figure 48/T.171 – Generic value substitution. This diagram shows two parallel processes. The top process starts with a 'Target Content Generic String' box containing 'Hello', which points to a 'Set Data' box with parameters (Target Content, 'substitution', 'no process', 'Bye'), which then points to a 'Target Content Generic String' box containing 'Bye'. The bottom process starts with a 'Target Content Generic List' box containing a list: 1) 'Hello', 2) false, 3) 'Bye'. This points to a 'Set Data' box with parameters (Target Content, 'substitution', 'no process', true), which then points to a 'Target Content Generic Boolean' box containing 'true'.](fda85db2e355bb8e3edcd5a74bf3d673_img.jpg)
+
+```
+
+graph LR
+    subgraph TopRow
+        A["Target Content  
+Generic String  
+\"Hello\""] --> B["Set Data  
+(Target Content,  
+\"substitution\",  
+\"no process\",  
+\"Bye\")"]
+        B --> C["Target Content  
+Generic String  
+\"Bye\""]
+    end
+    subgraph BottomRow
+        D["Target Content  
+Generic List  
+1) \"Hello\"  
+2) false  
+3) \"Bye\""] --> E["Set Data  
+(Target Content,  
+\"substitution\",  
+\"no process\",  
+true)"]
+        E --> F["Target Content  
+Generic Boolean  
+true"]
+    end
+  
+```
+
+Figure 48/T.171 – Generic value substitution. This diagram shows two parallel processes. The top process starts with a 'Target Content Generic String' box containing 'Hello', which points to a 'Set Data' box with parameters (Target Content, 'substitution', 'no process', 'Bye'), which then points to a 'Target Content Generic String' box containing 'Bye'. The bottom process starts with a 'Target Content Generic List' box containing a list: 1) 'Hello', 2) false, 3) 'Bye'. This points to a 'Set Data' box with parameters (Target Content, 'substitution', 'no process', true), which then points to a 'Target Content Generic Boolean' box containing 'true'.
+
+T0825930-96/d046
+
+**Figure 48/T.171 – Generic value substitution**
+
+![Figure 49/T.171 – Addition of an element to generic list. This diagram shows a single process starting with a 'Target Content Generic List' box containing a list: 1) 'Hello', 2) true. This points to a 'Set Data' box with parameters (Target Content, 'no substitution', 'no process', 'Bye'), which then points to a 'Target Content Generic List' box containing a list: 1) 'Hello', 2) true, 3) 'Bye'.](72d448a65347c51989171748789c7d4b_img.jpg)
+
+```
+
+graph LR
+    A["Target Content  
+Generic List  
+1) \"Hello\"  
+2) true"] --> B["Set Data  
+(Target Content,  
+\"no substitution\",  
+\"no process\",  
+\"Bye\")"]
+    B --> C["Target Content  
+Generic List  
+1) \"Hello\"  
+2) true  
+3) \"Bye\""]
+  
+```
+
+Figure 49/T.171 – Addition of an element to generic list. This diagram shows a single process starting with a 'Target Content Generic List' box containing a list: 1) 'Hello', 2) true. This points to a 'Set Data' box with parameters (Target Content, 'no substitution', 'no process', 'Bye'), which then points to a 'Target Content Generic List' box containing a list: 1) 'Hello', 2) true, 3) 'Bye'.
+
+T0825940-96/d047
+
+**Figure 49/T.171 – Addition of an element to generic list**
+
+![Figure 50/T.171 – Creation of list. This diagram shows a single process starting with a 'Target Content Generic Boolean' box containing 'Hello'. This points to a 'Set Data' box with parameters (Target Content, 'substitution', 'no process', index 3.2, 256), which then points to a 'Target Content Generic List' box containing a list: 1) 'unspecified', 2) 'unspecified', 3) (generic list) with sub-items 3.1) 'unspecified' and 3.2) 256.](3df1d2bf049815d761b03fb9cc2bc7ed_img.jpg)
+
+```
+
+graph LR
+    A["Target Content  
+Generic Boolean  
+\"Hello\""] --> B["Set Data  
+(Target Content,  
+\"substitution\",  
+\"no process\",  
+index 3.2,  
+256)"]
+    B --> C["Target Content  
+Generic List  
+1) \"unspecified\"  
+2) \"unspecified\"  
+3) (generic list)  
+3.1) \"unspecified\"  
+3.2) 256"]
+  
+```
+
+Figure 50/T.171 – Creation of list. This diagram shows a single process starting with a 'Target Content Generic Boolean' box containing 'Hello'. This points to a 'Set Data' box with parameters (Target Content, 'substitution', 'no process', index 3.2, 256), which then points to a 'Target Content Generic List' box containing a list: 1) 'unspecified', 2) 'unspecified', 3) (generic list) with sub-items 3.1) 'unspecified' and 3.2) 256.
+
+T0825950-96/d048
+
+**Figure 50/T.171 – Creation of list**
+
+![Figure 51/T.171: Substitute of an element in a generic list. The diagram shows a flow from a 'Target Content Generic List' to a 'Set Data' box and then to another 'Target Content Generic List'. The first list has elements 1) 'Hello' and 2) false. The 'Set Data' box contains '(Target Content, "substitution", "no process", index 2, "Bye")'. The second list has elements 1) 'Hello' and 2) 'Bye'.](3d46409f8d0190e611a910ff27f8ec07_img.jpg)
+
+Target Content Generic List
+
+1) "Hello"  
+2) false
+
+Set Data  
+(Target Content,  
+"substitution",  
+"no process",  
+index 2,  
+"Bye")
+
+Target Content Generic List
+
+1) "Hello"  
+2) "Bye"
+
+T0825960-96/d049
+
+Figure 51/T.171: Substitute of an element in a generic list. The diagram shows a flow from a 'Target Content Generic List' to a 'Set Data' box and then to another 'Target Content Generic List'. The first list has elements 1) 'Hello' and 2) false. The 'Set Data' box contains '(Target Content, "substitution", "no process", index 2, "Bye")'. The second list has elements 1) 'Hello' and 2) 'Bye'.
+
+**Figure 51/T.171 – Substitute of an element in a generic list**
+
+![Figure 52/T.171: Extension of a list. The diagram shows a flow from a 'Target Content Generic List' to a 'Set Data' box and then to an extended 'Target Content Generic List'. The first list has elements 1) 'Hello', 2) true, and 3) 'Bye'. The 'Set Data' box contains '(Target Content, "substitution", "no process", index 5.3, 256)'. The second list has elements 1) 'Hello', 2) true, 3) 'Bye', 4) 'unspecified', and 5) (generic list) with sub-elements 5.1) 'unspecified', 5.2) 'unspecified', and 5.3) 256.](65b5e4a95d403df0ea5e8ff94f162a6a_img.jpg)
+
+Target Content Generic List
+
+1) "Hello"  
+2) true  
+3) "Bye"
+
+Set Data  
+(Target Content,  
+"substitution",  
+"no process",  
+index 5.3,  
+256)
+
+Target Content Generic List
+
+1) "Hello"  
+2) true  
+3) "Bye"  
+4) "unspecified"  
+5) (generic list)  
+5.1) "unspecified",  
+5.2) "unspecified",  
+5.3) 256
+
+T0825970-96/d050
+
+Figure 52/T.171: Extension of a list. The diagram shows a flow from a 'Target Content Generic List' to a 'Set Data' box and then to an extended 'Target Content Generic List'. The first list has elements 1) 'Hello', 2) true, and 3) 'Bye'. The 'Set Data' box contains '(Target Content, "substitution", "no process", index 5.3, 256)'. The second list has elements 1) 'Hello', 2) true, 3) 'Bye', 4) 'unspecified', and 5) (generic list) with sub-elements 5.1) 'unspecified', 5.2) 'unspecified', and 5.3) 256.
+
+**Figure 52/T.171 – Extension of a list**
+
+![Figure 53/T.171: Incompatible generic list element ID. The diagram shows a flow from a 'Target Content Generic List' to a 'Set Data' box and then to a 'No Effect' box. The first list has elements 1) 'Hello', 2) false, 3) 'Bye', 4) 'unspecified', and 5) (generic list) with sub-elements 5.1) 'unspecified', 5.2) 'unspecified', and 5.3) 256. The 'Set Data' box contains '(Target Content, "substitution", "no process", index 4.1, 256)'. The final box is labeled 'No Effect'.](9874e3ac6f14360133f8e1674f79824f_img.jpg)
+
+Target Content Generic List
+
+1) "Hello"  
+2) false  
+3) "Bye"  
+4) "unspecified"  
+5) (generic list)  
+5.1) "unspecified",  
+5.2) "unspecified",  
+5.3) 256
+
+Set Data  
+(Target Content,  
+"substitution",  
+"no process",  
+index 4.1,  
+256)
+
+No Effect
+
+T0825980-96/d051
+
+Figure 53/T.171: Incompatible generic list element ID. The diagram shows a flow from a 'Target Content Generic List' to a 'Set Data' box and then to a 'No Effect' box. The first list has elements 1) 'Hello', 2) false, 3) 'Bye', 4) 'unspecified', and 5) (generic list) with sub-elements 5.1) 'unspecified', 5.2) 'unspecified', and 5.3) 256. The 'Set Data' box contains '(Target Content, "substitution", "no process", index 4.1, 256)'. The final box is labeled 'No Effect'.
+
+**Figure 53/T.171 – Incompatible generic list element ID**
+
+### 40.3.2 Add action
+
+This action provides an arithmetic operation that adds generic numeric, generic integer or generic ratio to the generic value contained in the data field of the target.
+
+This action has the following parameters:
+
+- Set of Content Target Param;
+- Generic List Elt ID Param;
+- Generic Value Param.
+
+This action may be targeted during the period O2.
+
+#### 40.3.2.1 Add action effect
+
+If the generic list element ID parameter is omitted, this action should be targeted to a content object which does not contain a generic list. Otherwise, this action should be targeted to a content object which contains a generic list and the specified generic list element ID should exist.
+
+The generic value type of the target content data and the specified generic value should be the same, and they are either generic numerics, generic integers or generic ratios.
+
+This action has the following effects:
+
+- 1) if the generic value parameter is provided, the content data or the element data specified by the generic list element ID parameter is increased by the generic value parameter;
+- 2) otherwise, the content data or the element data specified by the generic list element ID parameter is incremented by 1 (generic numeric 1, generic integer 1 or generic ratio 1 depending on the generic value type in the target content object).
+
+#### 40.3.2.2 Add additional error conditions
+
+- if one of the targets is not a content object in O2, this action is ignored for that target;
+- if the generic list element ID parameter is omitted and the target has a generic list, this action is ignored;
+- if the generic list element ID parameter is provided and the target does not have a generic list, this action is ignored;
+- if the generic list element ID parameter is provided and the target does not have a specified element, this action is ignored;
+- if the generic value type of the target content data and the specified generic value are different, this action is ignored;
+- if the generic value type of the target content data is neither generic numerics, generic integers nor generic ratio, this action is ignored;
+- if the target is not a non-mux content, this action is ignored for that target.
+
+### 40.3.3 Subtract action
+
+This action provides an arithmetic operation that subtracts generic numeric, generic integer or generic ratio from the generic value contained in the data field of the target.
+
+This action has the following parameters:
+
+- Set of Content Target Param;
+- Generic List Elt ID Param;
+- Generic Value Param.
+
+This action may be targeted during the period O2.
+
+#### 40.3.3.1 Subtract targeted to a single content object
+
+If the generic list element ID parameter is omitted, this action should be targeted to a content object which does not contain a generic list. Otherwise, this action should be targeted to a content object which contains a generic list and the specified generic list element ID should exist.
+
+The generic value type of the target content data and the specified generic value should be of the same type, and they are either generic numerics, generic integers or generic ratios.
+
+This action has the following effects:
+
+- 1) if the generic value parameter is provided, the content data or the element data specified by the generic list element ID parameter is decreased by the generic value parameter;
+- 2) otherwise, the content data or the element data specified by the generic list element ID parameter is decremented by 1 (generic numeric 1, generic integer 1 or generic ratio 1 depending on the generic value type in the target content object).
+
+#### **40.3.3.2 Subtract additional error conditions**
+
+- if one of the targets is not a content object in O2, this action is ignored for that target;
+- if the generic list element ID parameter is omitted and the target has a generic list, this action is ignored;
+- if the generic list element ID parameter is provided and the target does not have a generic list, this action is ignored;
+- if the generic list element ID parameter is provided and the target does not have a specified element, this action is ignored;
+- if the generic value type of the target content data and the specified generic value are different, this action is ignored;
+- if the generic value type of the target content data is neither generic numerics, generic integers nor generic ratio, this action is ignored;
+- if the target is not a non-mux content, this action is ignored for that target.
+
+### **40.4 Actions to retrieve the behaviour**
+
+This Recommendation defines means to get this behaviour by the use of the following action:
+
+- Get Data action (see 40.4.1).
+
+#### **40.4.1 Get Data action**
+
+This action retrieves a generic value or an element of a generic list stored in a content object.
+
+This action has the following parameters:
+
+- Content Target Param;
+- Generic List Elt ID Param.
+
+This action may be targeted during the period O2.
+
+##### **40.4.1.1 Get Data targeted to a content object**
+
+The MHEG effect of this action is to retrieve a generic value or an element of a generic list stored in a content object. This action evaluates a generic value as follows:
+
+- 1) if generic list element ID parameter is not specified, this action evaluates the whole generic value stored in the target content object;
+- 2) otherwise, this action evaluates the generic value stored in the place specified by the generic list element ID parameter within the target content object.
+
+##### **40.4.1.2 Get Data additional error conditions**
+
+- the target addresses multiple entities, e.g. use of an alias which addresses a list of targets, or use of the “\*” wildcard instead of a given rt-component number, or use of children or descendants tails, the action is ignored for that target;
+- if one of the targets is not a content object in O2, this action is ignored for that target;
+- if the target is not a content object which does not contain a generic value, e.g. a still picture, a video, this action is ignored for that target;
+
+- if the target is not accessible, e.g. the reference cannot be solved, the action is ignored for that target;
+- if the element list index is an incompatible element list index, i.e. it indicates a non-existent path within the data, this action returns “undefined”;
+- if the target is not a non-mux content, this action returns “undefined”.
+
+## **41 Content Class Copy Behaviour**
+
+This behaviour generates new content objects from an existing one.
+
+This behaviour enables to copy a model content object to other independent content objects. The copied content objects have independent identifications provided by the object designer. They are completely independent of the original content object, i.e. any modification to the original does not affect the copied content objects.
+
+### **41.1 Behaviour attributes and statuses**
+
+None.
+
+### **41.2 Actions to change the behaviour**
+
+This Recommendation defines means to modify this behaviour by the use of the following action:
+
+- Copy action (see 41.2.1).
+
+#### **41.2.1 Copy action**
+
+This action specifies a target content object as a source of the copy operation and a set of content objects as destinations of the copy operation.
+
+This action has the following parameters:
+
+- Content Target Param;
+- Set of Destination Param.
+
+This action may be targeted during the period O2.
+
+##### **41.2.1.1 Copy action effect**
+
+The effect of this action is as follows:
+
+- 1) If the content object specified as a destination parameter does not exist, the specified content object is created. If the destination is specified by an MHEG identifier, a content object containing the MHEG identifier is created.
+- 2) All attributes of the target content object except the MHEG identifier attribute are copied in each destination content object.
+
+A target content object may be specified by a container element which is the content object. However, a destination content object shall not be specified by a container element even if it is a content object.
+
+No rt-contents shall exist for a destination content object at the time of a Copy action.
+
+##### **41.2.1.2 Copy additional error conditions**
+
+- if one of the targets is not a content object in O2, this action is ignored for that target;
+- if rt-contents are created from a content object referenced in a destination parameter, this action is ignored for that destination;
+- if a content object referenced in a destination parameter is specified as a container element reference, this action is ignored for that destination;
+- if the target is not a non-mux content, this action is ignored for that target.
+
+## SECTION 6 – RT-OBJECTS BEHAVIOUR
+
+### 42 Rt-Objects Availability Behaviour
+
+This behaviour describes the availability for running for rt-objects by the MHEG engine. All rt-objects have this behaviour.
+
+#### 42.1 Behaviour attributes and statuses
+
+This behaviour is expressed using the following attribute or status:
+
+- Rt-Availability Status (see 42.2).
+
+#### 42.2 Rt-Availability Status
+
+The rt-availability status value of each rt-object should evaluate to “available” if the rt-object is available for running for the MHEG engine, i.e. the rt-object is created from a model object and in period R2. The rt-availability status value of each rt-object should be evaluated to “not-available” if the rt-object is not created or deleted, i.e. the rt-object is in period R1.
+
+Initially, the rt-availability status of each rt-object is “not available”.
+
+#### 42.3 Actions to change the behaviour
+
+This Recommendation defines means to modify this behaviour by the use of the following actions:
+
+- New action (see 42.3.1);
+- Delete action (see 42.3.2).
+
+##### 42.3.1 New action
+
+This action creates rt-objects from model objects. This is used to obtain a kind of view of the model object for running and possibly for perception by the user. The rt-object creation process is outside the scope of this Recommendation and is provided by the MHEG engine.
+
+This action has the following parameter:
+
+- Set of Rt-Target Param.
+
+This action may be targeted during the period R1.
+
+##### 42.3.1.1 New action effect
+
+The MHEG effect is processed immediately. There is no associated user effect. The MHEG effect of this action is as follows:
+
+- 1) Construct the targeted rt-object.  
+It is for the MHEG engine to decide if data copying of the model object is required.
+- 2) Assign the rt-object identifier. This is the target of the New action.
+- 3) Perform specific effects of the New action on the following objects:
+  - a) Rt-script:
+    - i) Passing parameter behaviour is initialised.
+    - ii) Rt-script termination behaviour is set to “not terminated”.
+  - b) Rt-Component:
+    - i) Presentation behaviours are initialised.
+    - ii) Interaction behaviour is initialised.
+
+- c) Rt-Composite:
+  - i) Construct each component within the rt-composite.  
+Each composite object represents one generation. The construction is recursive when a composite object is associated with a composition element. With this facility, the MHEG engine combines all the generations to construct a complete rt-composite.
+  - ii) Target a Plug action to each socket in the rt-composite – The data to be plugged is the data found in the associated model of the corresponding element. When an empty model is associated, a null rt-object is to be plugged in the corresponding socket.
+- 4) NOTE 1 – The Plug action is targeted automatically by the MHEG engine. The author need not specify this action. This is an advantage of the associated model facility in the composite object.
+- 5) NOTE 2 – Strictly speaking, a label or a component object cannot be plugged directly into a socket. When a label is associated, the MHEG engine is expected to create a content object with the label as data and then create an rt-content from this content. When a component is associated, the MHEG engine processes an implicit New action to create an rt-component from that component, and then plugs that rt-component into the socket.
+- 6) NOTE 3 – The New action is propagated to the next generation in the rt-composite through the effect of the Plug action:
+  - sockets presentation and structural dynamism behaviour is initialised;
+  - presentation behaviours are initialised.
+- 7) The running behaviour is initialised to “not running”.
+- 8) Set the rt-availability status of the targeted rt-object to “available”. The created rt-object enters in period R2.
+- 9) Rt-availability start-up link in a composite object is fired.
+
+When the original model object is in O1, an implicit Prepare action is targeted to the model object, and then the New action is applied as above.
+
+#### 42.3.1.2 New additional error conditions
+
+- if in one of the targets, the original object identification addresses an object which is not a model object, this action is ignored for this target;
+- if one of the targets does not address an rt-object, this action is ignored for this target;
+- if one of the targets is not an rt-object in R1, this action is ignored for that target.
+
+#### 42.3.2 Delete action
+
+This action removes rt-objects from the MHEG engine. This may be used to release resources in the MHEG engine. This action does not affect model objects from which rt-objects are created.
+
+This action has the following parameter:
+
+- Set of Rt-Target Param.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+##### 42.3.2.1 Delete action effect
+
+There is no direct user effect associated; however, there may be an indirect user effect in certain cases. The MHEG effect of this action is as follows:
+
+- 1) Perform specific effects of this action to the following targets:
+  - a) *Rt-script*:
+    - i) Passing parameters behaviour is destroyed.
+    - ii) Termination behaviour is destroyed.
+  - b) *Rt-Component*:
+    - i) Presentation behaviours are destroyed.
+    - ii) Interaction behaviour is destroyed.
+
+c) *Rt-Composite:*
+
+- i) Sockets presentation and structural dynamism behaviour is destroyed.  
+The Plug action defined in this behaviour is no longer applied to sockets. This behaviour is no longer possible.
+- ii) Presentation behaviour is destroyed.
+- iii) Propagates the Delete action to each rt-component plugged in each socket of this rt-composite. It destroys the complete rt-composite when the propagation is completed.
+- iv) If a label is plugged in a socket, destroys the dynamically created content object used for the Plug action process.
+
+2) Destroys running behaviour.
+
+3) Destroys the targeted rt-object.
+
+4) Set the rt-availability status of the targeted rt-object to “not available”. The rt-object enters in period R1.
+
+5) Rt-availability close-down link of the corresponding composite object is fired.
+
+#### 42.3.2.2 Delete additional error conditions
+
+- if in one of the targets, the original object identification addresses an object which is not a model object, this action is ignored for this target;
+- if in one of the targets, the original object identification addresses a model object which is not in period O2, this action is ignored for that target because the model object is not yet available;
+- if one of the targets is not an rt-object in R2, R3, and R3.TD, this action is ignored for that target.
+
+### 42.4 Actions to retrieve the behaviour
+
+This Recommendation defines means to get this behaviour by the use of the following action:
+
+- Get Rt-Availability Status action (see 42.4.1).
+
+#### 42.4.1 Get Rt-Availability Status action
+
+This action retrieves the availability status of each rt-object for the MHEG engine.
+
+This action has the following parameter:
+
+- Rt-Target Param.
+
+This action may be targeted during the periods R1, R2, R3 and R3.TD.
+
+##### 42.4.1.1 Get Rt-availability Status targeted to rt-object
+
+The MHEG effect of this action is as follows:
+
+- 1) if the targeted rt-object is in period R1, the rt-availability status is evaluated to “not available”;
+- 2) otherwise, it is evaluated to “available”.
+
+##### 42.4.1.2 Get Rt-Availability Status additional error conditions
+
+- the target addresses multiple entities, e.g. use of an alias which addresses a list of targets, or use of the “\*” wildcard instead of a given rt-component number, or use of children or descendants tails, the action is ignored for that target;
+- if the target is not an rt-object, this action is ignored for that target;
+- if the target is not accessible, e.g. the reference cannot be solved, the action is ignored for that target;
+- if in one of the targets, the original object identification addresses a model object which is not in period O2, this action is ignored for that target because the model object is not yet available.
+
+## 43 Rt-Objects Running Behaviour
+
+This behaviour is used to run and stop rt-objects.
+
+### 43.1 Behaviour attributes and statuses
+
+This behaviour is expressed using the following attribute or status:
+
+- Running Status (see 43.2).
+
+### 43.2 Running Status
+
+An rt-object may be run by the MHEG engine at different moments in time. When an rt-component is running, it may be presented to the user. When an rt-script is running, the script itself is under processing.
+
+The running of each rt-object for the MHEG engine may be evaluated.
+
+Initially, the running status of each rt-object is evaluated to “not running” and the rt-object is in period R2. The running status of each rt-object is evaluated to “running” if the rt-object is running and its presentation or processing is controlled by the MHEG engine.
+
+### 43.3 Actions to change the behaviour
+
+This Recommendation defines means to modify this behaviour by the use of the following actions:
+
+- Run action (see 43.3.1);
+- Stop action (see 43.3.2).
+
+#### 43.3.1 Run action
+
+This action enables the presentation and processing of the rt-object for the MHEG engine.
+
+This action has the following parameters:
+
+- Set of Rt-Target Param;
+- Number of Performances Param.
+
+This action may be targeted during the periods R1 and R2.
+
+##### 43.3.1.1 MHEG effect of Run targeted to a single rt-object
+
+If the rt-availability status of the target is “not available”, an implicit New action is targeted at this rt-object. If the target is in period R2, the MHEG effect is processed immediately as follows:
+
+- 1) Place the target under the control of the presentation or processing system.
+- 2) Set number of completed performances to 0.
+- 3) Perform specific effects as follows:
+  - Rt-Component: The current temporal position is positioned at the current temporal position of its RPS.
+- 4) NOTE 1 – By default, when an rt-component is created, its current temporal position is set to the start point of its OVD, i.e. its initial temporal position.
+- 5) NOTE 2 – The Run action starts the presentation of the rt-component at the current temporal position of the target where it has been left by a previous Run action, i.e. the current temporal position is not reset by targeting the Run action.
+- 6) Set the running status to “running”. The rt-object enters in period R3.
+- 7) If the current temporal position reaches the terminal temporal position, the number of completed performances is increased by 1.
+- 8) If the specified number of performances is not equal to the number of completed performances, the current temporal position is set to the initial temporal position and presentation continues from the beginning of the OVD.
+- 9) The temporal termination of the target affects if the specified number of performances is equal to the number of completed performances.
+
+#### 43.3.1.2 User effect of Run targeted to a single rt-object
+
+The user effect of this action is as follows:
+
+- 1) Rt-script: The user effect is described within the script data. At the end of the process of an rt-script, an implicit stop action is targeted at the rt-script by the MHEG engine.  
+
+NOTE 1 – In that case, the termination status is set to “terminated”. The process of the rt-script has been completed until the end of the script.
+- 2) Rt-Component:
+  - a) The current temporal position of the target progresses within the OVD of the target taking into account the current GTF value. All presentation behaviour attributes may affect the user effect (e.g. position, size, audible volume).
+  - b) When the terminal temporal position (i.e. the end of OVD) of the target is crossed after the specified number of performances, the following applies:
+    - If the temporal termination of the target is equal to “freeze”, the current GTF value is memorised and the GTF value is temporarily set to 0 by the MHEG engine. The GTF of the target becomes 0. The current temporal position remains constant at the terminal temporal position value. The rt-component is still “running”.
+- 3) NOTE 1 – If the information presented is a video, the last frame may be displayed. If it is an audio, no sound may be perceived. If it is a still picture, it may remain presented.
+- 4) NOTE 2 – If the current temporal position is changed to another position, the memorised GTF values is resumed.
+  - Otherwise (the temporal termination of the target is equal to “stop”), an implicit Stop action is targeted to the rt-component.
+- 5) NOTE 3 – By default, the terminal temporal position is set to the rt-component original duration. If this duration is infinite, an explicit Stop action should be targeted to that rt-component to stop the user effect of the Run action.
+- 6) NOTE 4 – If a timestone is positioned on the terminal temporal position, it is crossed as many times as the specified number of performance just when the current temporal position of rt-component crosses it. If an rt-component is set to “freeze” and there is such a timestone, the timestone is crossed just at the time the current temporal position arrives on the terminal temporal position every time.
+- 7) Rt-Composite:
+  - a) All the user effects for rt-component applies.
+  - b) Each time the current temporal position of an rt-composite crosses a temporal position where a child socket is attached, an implicit Run action is to be targeted to that socket.  
+
+A socket may be positioned on a temporal position on its parent T axis (PRPS) using a Set PVD Position action.
+  - c) If the terminal temporal position of an rt-composite is crossed, a Set CTP action is targeted to each socket that is still running to set it to its terminal temporal position.
+- 8) NOTE 5 – The VD of the sockets that are running and not at their terminal temporal position are effectively shortened when the terminal temporal position of the parent is crossed. Whatever their positions, if the parent is terminated, they are terminated too.
+- 9) NOTE 6 – They are positioned at their terminal temporal position so that they restart at their initial temporal position when they become running again.
+
+#### 43.3.1.3 Run additional error conditions
+
+- If the target is not a socket whose parent is not in period R3 or R3.TD, this action is ignored for that target. The parent needs to be running to set the children or descendants running.
+- If one of the targets is not an rt-object in R1 or R2, this action is ignored for that target.
+- If the number of performance is less than 1, this action is ignored for the whole target set.
+
+### 43.3.2 Stop action
+
+This action sets the running status to “not running” and stops possible user effects.
+
+This action has the following parameter:
+
+- Set of Rt-Target Param.
+
+This action may be targeted during the periods R3 and R3.TD.
+
+#### 43.3.2.1 Stop targeted to a single rt-object
+
+The action effect of this action is as follows:
+
+- 1) Perform specific effects to following objects:
+  - a) Rt-Component: The progression of the current temporal position is stopped and it remains at its current value.
+  - b) Rt-Composite: The Stop action is propagated to all child sockets, i.e. to all descendant sockets recursively.
+- 2) NOTE 1 – A socket cannot be running if its parent is not running.
+- 3) NOTE 2 – All sockets, that are assigned to this composition space and that are directly assigned to a channel, are stopped.
+- 4) Stop possible user effects of the target.
+- 5) Set the running status to “not running”. The rt-object enters in period R2, and all the user effects are stopped.
+
+#### 43.3.2.2 Stop additional error conditions
+
+- If one of the targets is not an rt-object in R3 or R3.TD, this action is ignored for that target.
+- If the target is not a socket whose parent is not in period R3 or R3.TD, this action is ignored for that target. The children or descendants cannot be running when the parent is not running. The Stop action is useless in this case.
+
+### 43.4 Actions to retrieve the behaviour
+
+This Recommendation defines means to get this behaviour by the use of the following action:
+
+- Get Running Status action (see 43.4.1).
+
+#### 43.4.1 Get Running Status action
+
+This action gets the running status of each rt-object.
+
+This action has the following parameter:
+
+- Rt-Target Param.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+##### 43.4.1.1 MHEG effect
+
+This action evaluates the running status as follows:
+
+- 1) if the target is in period R3 or R3.TD, the running status is evaluated “running”;
+- 2) otherwise, it is “not running”.
+
+##### 43.4.1.2 Get Running Status additional error conditions
+
+- the target addresses multiple entities, e.g. use of an alias which addresses a list of targets, or use of the “\*” wildcard instead of a given rt-component number, or use of children or descendants tails, the action is ignored for that target;
+- if one of the targets is not an rt-object in R2, R3 or R3.TD, this action is ignored for that target;
+- if the target is not accessible, e.g. the reference cannot be solved, the action is ignored for that target;
+- if in one of the targets, the original object identification addresses a model object which is not in period O2, this action is ignored for that target because the model object is not yet available.
+
+## 44 Rt-Script Passing Parameters Behaviour
+
+This behaviour is used to pass parameters to rt-script.
+
+### 44.1 Behaviour attributes and statuses
+
+None.
+
+### 44.2 Actions to change the behaviour
+
+This Recommendation defines means to modify this behaviour by the use of the following action:
+
+- Set Parameters action (see 44.2.1).
+
+#### 44.2.1 Set Parameters action
+
+This action enables to pass parameters to rt-scripts and to return information back from the rt-script processing. Any number of rt-script parameters may be defined for a given rt-script.
+
+Each rt-script parameter is specified as a generic value or a content object. Since a generic value is a result of a Get action or a constant, using a generic value is similar to “call by value” However, using a content object is similar to “call by reference” since a content object may contain or refer to a generic value, image, video and so on. This action may be targeted at any time during the life of an rt-script even when an rt-script is under processing of a script engine, and may also be targeted several times during the life of the rt-script.
+
+The semantics, the parameter order, the type (input, output or input/output) and any usage of each parameter shall be defined by the object designer and shall be supported by a using application and a script engine.
+
+No passing parameter may be specified. It may be used to signal or to notify the script engine or the MHEG engine. The semantics of this usage depends on the using application.
+
+This action has the following parameters:
+
+- Set of Rt-Script Target Param;
+- Set of Passing Param.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+#### 44.2.1.1 Set Parameter action effect
+
+There is no direct user effect associated with this action. However, there may be an indirect user effect in certain cases.
+
+The MHEG effect of this action is to pass the specified passing parameters to the target.
+
+Content objects in passing parameters may be used to return information from a script engine to the MHEG engine. Therefore, if a content object is used as a parameter from which rt-contents are created and running, there may be indirect user effects by an rt-script due to the data modification within the content object. The presentation of such rt-content may be modified.
+
+Suppose an rt-script is in charge of the access to a database to retrieve information and the results are set into a content object. The result may be used to complete a form filling, for example, as follows:
+
+- An rt-script RS1 is created from a model script object MS1: New (RS1).
+- A content object CO1 and two generic values of integers are passed to RS1 as parameters: Set Parameters (RS1, CO1, 13, 15).
+- RS1 is executed: Run (RS1).
+- The execution of RS1 uses the parameters set by the Set Parameters action during the process. After finishing the script, the execution result is stored in CO1.
+- The value in CO1 may be retrieved by using a link condition for further processing in the MHEG engine: “When the running status of RS1 becomes “not running””, Get Data (CO1).
+
+#### 44.2.1.2 Set Parameters additional error conditions
+
+- if one of the targets is not an rt-script in R2, R3 or R3.TD, this action is ignored for that target;
+- if the reference to content object used to pass parameters is not accessible or does not address a content object, this parameter is replaced by the value “undefined”.
+
+## 45 Rt-Scripts Termination Behaviour
+
+This behaviour evaluates the complete termination of an rt-script process inside a script engine for the MHEG engine.
+
+### 45.1 Behaviour attributes and statuses
+
+This behaviour is expressed using the following attribute or status:
+
+- Termination Status (see 45.2).
+
+### 45.2 Termination Status
+
+This attribute specifies the execution status of an rt-script. It is either “terminated” or “not terminated”. If the execution of an rt-script is completed, the termination status is evaluated to “terminated”. Otherwise, it is evaluated to “not terminated”.
+
+After the creation of an rt-script, the termination status is initialised “not terminated”. After receiving a Run action, the rt-script is executed by a script engine. When it is terminated (i.e. its termination status is changed from “not terminated” to “terminated”), an implicit Stop action is targeted to the rt-script. If a Stop action is targeted during the execution of the rt-script, it becomes “not running” and “not terminated”. Only the rt-objects that are “not terminated” may be rerun. If the same script is to be executed, two different rt-scripts should be made and run. There is no direct relationship between the running status and the termination status.
+
+### 45.3 Actions to retrieve the behaviour
+
+This Recommendation defines means to get this behaviour by the use of the following action:
+
+- Get Termination Status action (see 45.3.1).
+
+#### 45.3.1 Get Termination Status action
+
+This action retrieves the termination status of the target.
+
+This action has the following parameter:
+
+- Rt-Script Target Param.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+#### 45.3.1.1 Get Termination Status action effect
+
+The effect of this action is as follows:
+
+- 1) If the process of the target rt-script is not terminated, the Termination Status should be evaluated to “not terminated”;
+- 2) Otherwise, it should be evaluated to “terminated”.
+
+#### 45.3.1.2 Get Termination Status additional error conditions
+
+- the target addresses multiple entities, e.g. use of an alias which addresses a list of targets, or use of the “\*” wildcard instead of a given rt-component number, or use of children or descendants tails, the action is ignored for that target;
+- if one of the targets is not an rt-script in R2, R3 or R3.TD, this action is ignored for that target;
+- if the target is not accessible, e.g. the reference cannot be solved, the action is ignored for that target.
+
+## 46 Sockets Presentation and Structural Dynamism Behaviour
+
+This behaviour attaches or detaches an rt-component to a socket. This may be done at any time during the life of the rt-composite once the rt-composite is created.
+
+This behaviour has the following particularities:
+
+- 1) Attachment of an rt-content to a socket. This socket becomes an rt-content socket, and the rt-content is perceived through the socket.
+- 2) Attachment of an rt-composite to a socket. This socket becomes an rt-composite socket. A new set of generations is attached to the socket. If each generation contains a set of rt-content sockets, a new depth of presentation may be perceived.
+- 3) Replacement of an rt-content in an rt-content socket. A new rt-content may be perceived.
+- 4) Replacement of an rt-composite in an rt-composite socket. A generation and all its descendants are replaced by a new set of generations. A new generation may be perceived.
+- 5) Detachment of an rt-component from a socket. The socket becomes an empty socket. No presentation is perceived.
+
+Initially, each socket has an rt-component plugged into it. This is a null rt-object or an rt-component created from the associated model information exchanged within the composite.
+
+### 46.1 Behaviour attributes and statuses
+
+None.
+
+### 46.2 Actions to change the behaviour
+
+This Recommendation defines means to modify this behaviour by the use of the following action:
+
+- Plug action (see 46.2.1).
+
+#### 46.2.1 Plug action
+
+This action enables dynamic presentation and structuring of the sockets. It specifies the information to be plugged into a socket. This is used to obtain a different presentation or structure from the same composite object model.
+
+The parent of the target should be in R2, R3 or R3.TD
+
+This action has the following parameters:
+
+- Set of Socket Target Param;
+- Plug In Param.
+
+This action may be targeted during any period.
+
+#### 46.2.1.1 Plug action effect
+
+The MHEG effect of this action is as follows:
+
+- 1) If the specified socket exists, the following applies:
+  - a) If a null rt-object is to be plugged in:
+    - i) An implicit Delete action is targeted to the rt-component currently plugged into the targeted socket.
+    - ii) A null rt-object is attached to the targeted socket. The socket becomes an empty socket.
+    - iii) If the running status of a previous plugged-in socket was “running”, an implicit Run action is targeted to the socket.
+    - iv) Any previous user effects may cease.
+  - b) If an rt-component is to be plugged in:
+    - i) A copy of the specified rt-component to be plugged in is made. This new rt-component has no explicit identification and is referenced only via the socket addressing in which it is to be plugged.
+
+- 2) NOTE 1 – It is for the MHEG engine to assign this identification and ensure that it is unique. It should not be possible for an author to use the same value.
+- 3) NOTE 2 – For an rt-content, a New action may be performed on the model object and then a transfer of behaviour may be performed from the targeted rt-content to this newly created rt-content.
+- 4) NOTE 3 – For an rt-composite, it is not possible to perform a New action on the model composite object in order to make a copy. The created one is not always the same as the targeted rt-composite due to the structural and presentation dynamism behaviour of sockets that may be applied to the rt-composite.
+  - ii) If the running status of the new made rt-component is “running”, it is set to “not running”.
+  - iii) An implicit Delete action is targeted to the rt-component currently plugged into the targeted socket.
+  - iv) The created new rt-content is attached to the targeted socket with its currently associated behaviours.
+  - v) If the running status of previous plugged in socket was “running”, an implicit Run action is targeted to the socket.
+  - vi) Any previous user effects may be modified as a result of the Plug action.
+- c) If a component object is to be plugged in:
+  - i) An rt-component is created from this model component object. This rt-component has no explicit identification and is referenced only via the socket addressing in which it is to be plugged.
+  - ii) This new made rt-component is attached to the targeted socket with its currently associated behaviours.
+  - iii) If the running status of previous plugged in socket was “running”, an implicit Run action is targeted to the socket.
+  - iv) Any previous user effects may be modified as a result of the Plug action.
+- d) If a label is to be plugged in:
+  - i) A content object is dynamically created. This content object has no explicit identification and is referenced only via the socket in which an rt-content created from this content object is to be plugged.
+  - ii) Apply all steps in the case as a component object is to be plugged in.
+- 5) Otherwise (the specified socket does not exist), the specified socket is to be created, and the following applies:
+  - a) If the first index of the socket address does not exist, the children sockets are completed with empty sockets until this socket index. For example, if the number of sockets is  $n$  and the first index of the targeted socket address is  $m$  ( $n < m$ ), new sockets should be indexed from  $n + 1$  to  $m$ .
+  - b) If the second index of the socket address is provided:
+    - i) If the first index indicates an rt-composite and the second index does not exist, the children sockets of this second generation are completed with empty sockets as described in the first index case.
+    - ii) If the first index does not indicate an rt-composite:
+      - An implicit Delete action is targeted to the rt-content currently plugged-in there.
+      - A new rt-composite is created with the number of sockets equal to the second index. Each socket within this rt-composite is created as an empty socket. This new rt-composite has no explicit identification and is referenced only via the socket addressing in which it is to be plugged.
+      - This new rt-composite is plugged into the socket addressed by the first index.
+
+- c) Above steps are repeated until the last index of the targeted socket address.
+- d) Once socket creations are completed, the target addresses an empty socket and the steps for existing socket address described above is applied.
+
+#### 46.2.1.2 Plug additional error conditions
+
+- if one of the targets does not address a socket that exists or does not exist, this action is ignored for that target;
+- if one of the targets is a socket with its parent in period R1, this action is ignored for that target.
+
+## 47 Rt-Composite Navigation Behaviour
+
+This behaviour provides a navigation through the trees formed by the rt-composites.
+
+### 47.1 Behaviour attributes and statuses
+
+This behaviour is expressed using the following attributes or statuses:
+
+- Rt-composite address (see 47.2);
+- Navigation Command (see 47.3);
+- Child (see 47.4);
+- EmptyChild (see 47.5);
+- Sibling (see 47.6);
+- Ancestor (see 47.7).
+
+### 47.2 Rt-Composite Address
+
+An address referencing an rt-composite.
+
+### 47.3 Navigation Command
+
+It gives a navigation path. It is a choice among “Child”, “EmptyChild”, “Sibling” or “Ancestor”.
+
+### 47.4 Child
+
+Navigation path to reach a child. It is expressed as an integer  $N > 0$  for N-th child, “last” which specifies the last indexed child or “random” which specifies randomised indexed child.
+
+### 47.5 EmptyChild
+
+Navigation path to reach an empty socket. It is expressed as an integer  $N > 0$  for N-th empty socket or “last” which specifies the last empty socket in a composite.
+
+### 47.6 Sibling
+
+Navigation path to reach a relative sibling. It is expressed as an integer for relative sibling, e.g. (1 = previous, +1 = next, 0 = current).
+
+### 47.7 Ancestor
+
+Navigation path to reach an ancestor. It is expressed as an integer  $N \geq 0$  for N-th previous generation or “root” which specifies the root. Any ancestor of root is root.
+
+## **47.8 Actions to retrieve the behaviour**
+
+This Recommendation defines means to get this behaviour by the use of the following action:
+
+- Get Rt-Composite Address action (see 47.8.1).
+
+### **47.8.1 Get Rt-Composite Address action**
+
+This action provides means to rise to the root, to descend to leaves and to explore the intermediate levels (nodes) in a composition tree.
+
+This action has the following parameters:
+
+- Rt-Composite Target Param;
+- Navigation Command Param.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+#### **47.8.1.1 Get Rt-Composite Address effect**
+
+The result of the action is a generic reference addressing an rt-composite specified by the navigation command parameter.
+
+##### **NOTES**
+
+- 1 – Clearly this reference is suitable for use as a target of other actions.
+- 2 – It may be stored in a content object with Set Data action (see 72.8.1) to be used later.
+
+This action may be recursively used.
+
+#### **47.8.1.2 Get Rt-Composite Address additional error conditions**
+
+- if one of the targets is not an rt-component in R2, R3 or R3.TD, this action is ignored for that target;
+- if the target is not an rt-component, the action is ignored for that target;
+- if the target is not accessible, e.g. the reference cannot be solved, the action is ignored for that target;
+- if in one of the targets, the original object identification addresses an object which is not a model object, this action is ignored for this target;
+- navigating to a non-existent socket returns “undefined”;
+- if the specified navigation command parameter is invalid, “undefined” is returned.
+
+## **48 Rt-Components Rps Assignment Behaviour**
+
+This behaviour assigns rt-components to an RPS, i.e. a composition space or a channel.
+
+### **48.1 Behaviour attributes and statuses**
+
+This behaviour is expressed using the following attribute or status:
+
+- RPS Assignment (see 48.2).
+
+### **48.2 RPS Assignment**
+
+An RPS is a composition space or a channel.
+
+### **48.3 Actions to change the behaviour**
+
+This Recommendation defines means to modify this behaviour by the use of the following action:
+
+- Set RPS Assignment action (see 48.3.1).
+
+### 48.3.1 Set RPS Assignment action
+
+This action assigns an rt-component to an RPS.
+
+This action has the following parameters:
+
+- Set of Rt-Component Target Param;
+- RPS Assignment Param.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+#### 48.3.1.1 Set RPS Assignment action effect
+
+The MHEG effect of this action is as follows:
+
+- 1) if the RPS parameter is specified as a reference to a channel, the current RPS assignment of this target is changed to the specified channel;
+- 2) otherwise, the current RPS assignment of this target is changed to the PRPS for an rt-component target and to the default channel for a root rt-component target.
+
+After this action, the old OPS-RPS relationship is destroyed and a new one is established. Therefore, previous PVD position mapping and previous PVS mapping of the target are completely destroyed and reinitialised.
+
+#### 48.3.1.2 Set RPS Assignment additional error conditions
+
+- if one of the targets is not an rt-component in R2, R3 or R3.TD, this action is ignored for that target;
+- if the previous RPS assignment and the specified RPS assignment are the same, this action is ignored for that target;
+- if the specified reference to a channel does not address an available channel (i.e. the channel is not in period C2), this reference is replaced by the default channel reference and the action should be applied for the default channel.
+
+## 48.4 Actions to retrieve the behaviour
+
+This Recommendation defines means to get this behaviour by the use of the following action:
+
+- Get RPS Assignment action (see 48.4.1).
+
+### 48.4.1 Get RPS Assignment action
+
+This action retrieves the RPS assignment to an rt-component and a root rt-component.
+
+This action has the following parameter:
+
+- Rt-Component Target Param.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+#### 48.4.1.1 Get RPS Assignment action effect
+
+The MHEG effect of this action is to retrieve the RPS assigned to the target. The following applies:
+
+- 1) if the target is assigned to a channel, this channel identifier is retrieved;
+- 2) If the target is assigned to PRPS, the value “prps” is retrieved.
+
+#### 48.4.1.2 Get RPS Assignment additional error conditions
+
+- the target addresses multiple entities, e.g. use of an alias which addresses a list of targets, or use of the “\*” wildcard instead of a given rt-component number, or use of children or descendants tails, the action is ignored for that target;
+- if the target is not an rt-component, the action is ignored for that target;
+- if the target is not accessible, e.g. the reference cannot be solved, the action is ignored for this target.
+
+## 49 Rt-Components Perceptability Behaviour
+
+This behaviour is used to represent perceptability of rt-components and root rt-components for the MHEG engine.
+
+Rt-Components and root rt-components concerned by this behaviour may be either “visible” or “audible”.
+
+### 49.1 Behaviour attributes and statuses
+
+This behaviour is expressed using the following attributes or statuses:
+
+- Perceptability (see 49.2);
+- Presentation Priority (see 49.3).
+
+### 49.2 Perceptability
+
+The perceptability value is defined in the interval between 0% to 100% represented by a generic ratio.
+
+Each rt-content or root rt-content has a perceptability. How to perceive an rt-content or a root rt-content is influenced by this value. If the perceptability value is set to zero, an rt-content or a root rt-content is not perceived. If the perceptability value is set to 100%, the original perception of an rt-content or a root rt-content is perceived. How to perceive an rt-content or a root rt-content on other perceptability values depends on the MHEG engine.
+
+NOTE – The intensity of a picture may be controlled from 0% to 100%.
+
+Each rt-composite or root rt-composite also has a perceptability. How to perceive its descendants is influenced by this value. If the perceptability value is set to zero, all descendants are not perceived. If the perceptability value is set to 100%, the original perception of all descendants taking into account their own perceptability values is perceived. How to perceive all descendants on other perceptability values depends on the MHEG engine.
+
+Initially, all rt-objects shall have perceptability values as 100%.
+
+### 49.3 Presentation Priority
+
+All rt-components assigned to a same channel have priorities relative to another. The presentation order is determined in one RPS. If this RPS is of an rt-composite, this may have also a presentation priority relative to other rt-components presented in a same RPS.
+
+A presentation priority is defined by an integer from 0 to 255, where 0 represents the highest priority in the presentation stacking order and 255 represents the lowest priority in it.
+
+If two rt-components have the same presentation priority values in the same RPS, the stacking order is defined by Run actions targeted to these rt-components. That means that the rt-component to which a Run action is targeted most recently has higher presentation priority. If the Run actions are targeted in parallel for those rt-components, the stacking order depends on implementation. However, there are no affections for their presentation priority values.
+
+Initially, all rt-components have a presentation priority value 0.
+
+### 49.4 Actions to change the behaviour
+
+This Recommendation defines means to modify this behaviour by the use of the following actions:
+
+- Set Perceptability action (see 49.4.1);
+- Set Presentation Priority action (see 49.4.2).
+
+#### 49.4.1 Set Perceptability action
+
+This action enables to change the perceptability of an rt-component or a root rt-component.
+
+This action has the following parameters:
+
+- Set of Rt-Component Target Param.
+- Perceptability Param: Specifies the perceptability to be assigned to an rt-component.
+
+- Transition Duration Param: Specifies the perceptability to be assigned to an rt-component.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+#### **49.4.1.1 Set Perceptability action effect**
+
+The Set Perceptability action effect is as follows:
+
+- 1) set the perceptability of the targeted rt-component as specified;
+- 2) if the target is running, there may be a user effect associated with this action;
+- 3) if the transition duration parameter is specified, the perceptability is changed gradually.
+
+#### **49.4.1.2 Set Perceptability additional error conditions**
+
+- if one of the targets is not an rt-component in R2, R3 or R3.TD, this action is ignored for that target;
+- if the presentation priority parameter value is not in interval (0%, 100%), it shall be set to the value 0;
+- if the transition duration is negative, it is set to zero.
+
+#### **49.4.2 Set Presentation Priority action**
+
+This action enables to change the presentation priority of an rt-component or a root rt-component.
+
+This action has the following parameters:
+
+- Set of Rt-Component Target Param;
+- Presentation Priority Param;
+- Transition Duration Param.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+#### **49.4.2.1 Set Presentation Priority action effect**
+
+The effect of Set Presentation Priority action is as follows:
+
+- 1) Set the presentation priority of the targeted rt-component is set as specified.
+- 2) If the specified presentation priority is an integer, the presentation priority of the target is set to this value.
+- 3) If the specified presentation priority is “up-priority”, the presentation priority of the target is decreased by 1. If the value is 0, the value remains 0.
+- 4) Otherwise (the specified presentation priority is “down-priority”), the presentation priority of the target is increased by 1. If the value is 255, the value remains 255.
+
+If the target is running, there may be a user effect associated with this action.
+
+If the presentation priority is equal to “up-priority” or “down-priority”, the transition parameter is ignored.
+
+The use of a transition duration parameter allows an rt-component to appear with a gradual presentation priority. Typically, this is accompanied with a special effect such as a change of the stacking order of the presentation progressively.
+
+#### **49.4.2.2 Set Presentation Priority additional error conditions**
+
+- if one of the targets is not an rt-component in R2, R3 or R3.TD, this action is ignored for that target;
+- if the presentation priority parameter value is not in interval (0, 255), it is set to the value 0;
+- if the transition duration is negative, it is set to zero.
+
+## **49.5 Actions to retrieve the behaviour**
+
+This Recommendation defines means to get this behaviour by the use of the following actions:
+
+- Get Perceptability action (see 49.5.1);
+- Get Presentation Priority action (see 49.5.2).
+
+### **49.5.1 Get Perceptability action**
+
+This action retrieves the perceptability value of an rt-component.
+
+This action has the following parameter:
+
+- Rt-Component Target Param.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+#### **49.5.1.1 Get Perceptability action effect**
+
+This action evaluates a generic ratio within the interval (0, 1) that is the current value of the perceptability.
+
+#### **49.5.1.2 Get Perceptability additional error conditions**
+
+- the target addresses multiple entities, e.g. use of an alias which addresses a list of targets, or use of the “\*” wildcard instead of a given rt-component number, or use of children or descendants tails, the action is ignored for that target;
+- if the target is not an rt-component, the action is ignored for that target;
+- if the target is not accessible, e.g. the reference cannot be solved, the action is ignored for that target.
+
+### **49.5.2 Get Presentation Priority action**
+
+This action retrieves the presentation priority value of an rt-component.
+
+This action has the following parameter:
+
+- Rt-Component Target Param.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+#### **49.5.2.1 Get Presentation Priority action effect**
+
+This action evaluates a generic integer within the interval (0, 255) that is the current value of the presentation priority.
+
+#### **49.5.2.2 Get Presentation Priority additional error conditions**
+
+- the target addresses multiple entities, e.g. use of an alias which addresses a list of targets, or use of the “\*” wildcard instead of a given rt-component number, or use of children or descendants tails, the action is ignored for that target;
+- if the target is not an rt-component, the action is ignored for that target;
+- if the target is not accessible, e.g. the reference cannot be solved, the action is ignored for that target.
+
+## **50 Rt-Components Temporal Behaviour**
+
+This behaviour is used to express the presentability of rt-components for the MHEG engine in time.
+
+### **50.1 Behaviour attributes and statuses**
+
+This behaviour is expressed using the following attributes or statuses:
+
+- OD (see 50.2);
+- POD (see 50.3);
+- OVD (see 50.4);
+
+- PVD (see 50.5);
+- Temporal Termination (see 50.6);
+- PVD Position (see 50.7);
+- CTP (see 50.8);
+- GTF (see 50.9);
+- Timestone Status (see 50.10);
+- Timestone ID (see 50.11);
+- Expected OVD Result (see 50.12);
+- Expected PVD Result (see 50.13).
+
+## 50.2 OD
+
+Each rt-component and channel has an OD initialised by the process described in the original presentation space. Each OD for an rt-component is set only once at the time of creation and shall not be changed.
+
+## 50.3 POD
+
+Each OD is projected to its RPS. The projection is POD. The POD of an rt-component is calculated by the GTF assigned to the rt-component as  $POD = OD \times GTF$ .
+
+## 50.4 OVD
+
+Each rt-component has an OVD which is defined as a subset of the OD. Only the part specified as the OVD is perceived by the user. The portion of the OD that is outside the OVD is clipped. The OVD is specified by the initial temporal position and the terminal temporal position that are positions within the OD. Both points are specified by the OGTU in the OPS.
+
+By default, the initial temporal position of the OVD is initialised to 0 (i.e. the origin of the OD), and the terminal temporal position of the OVD is initialised to the length of the OD (i.e. the end point of the OD).
+
+The terminal temporal position may be specified smaller than the initial temporal position (see Figure 56). The length of the OVD is always defined starting from the initial temporal position to the terminal temporal position taking into account the direction of the T axis.
+
+If the terminal temporal position is smaller than the initial temporal position, the VD length is as follows:
+
+- [OD end point (OVD initial temporal position) + (OVD terminal temporal position) OD start point (0)]
+
+Otherwise:
+
+- OVD terminal temporal position (OVD initial temporal position).
+
+## 50.5 PVD
+
+The projection of each OVD in its RPS results in the PVD. The PVD of an rt-component is calculated by the GTF assigned to the rt-component as  $PVD = OVD \times GTF$ .
+
+## 50.6 Temporal Termination
+
+The temporal termination allows an rt-composite to indicate the choice of the termination process when the presentation of the rt-composite is finished run (see 72.11.1).
+
+This attribute is either “freeze” or “stop”. Initially, the temporal termination is set to “freeze”.
+
+## 50.7 PVD Position
+
+The OVD of an rt-composite is projected to its RPS as PVD. The length of the PVD is controlled by the GTF value of the rt-composite, and the position of the PVD is controlled implicitly or explicitly by an elementary action as follows:
+
+- 1) The PVD position of a root rt-component is implicitly determined by a Run action targeted to the root rt-component.
+- 2) After the Run action, the CTP of the target is positioned to its current RPS (CPS) temporal position in the temporal life of the RPS. The PVD of the target is positioned to the RPS taking into account the CTP.
+- 3) The CTP of the target progresses taking into account its GTF value.
+- 4) The PVD position of an rt-component is determined as follows:
+- 5) Initially, the PVD of an rt-component is not positioned to its RPS-OD. If a Run action is targeted to such an rt-component, the CTP of the target is implicitly positioned to its current RPS temporal position in the temporal life of the RPS.
+- 6) Once an rt-component is positioned to its RPS-OD by using a Set PVD Position action, the following applies (see Figure 54):
+- 7) The PVD of the rt-component is attached to the RPS-OD tightly. Therefore, the CTP of the rt-component is calculated from the CTP of its RPS automatically and shall not be changed by a Set CTP action.
+- 8) If the parent CTP exists outside the child PVD, the CTP of an rt-component is “undefined”.
+- 9) If the parent of the rt-composite is running and the parent CTP enters in an rt-component PVD, the running status of the rt-component is set to “running” and presentation begins taking into account the playing direction of the parent (forward or reverse). The CTPs of children progress synchronously with the parent CTP.
+- 10) If the parent of the rt-composite is running and the parent CTP gets out of an rt-component PVD, the running status of the rt-component is set to “not running” and its presentation ends.
+- 11) If a part of the PVD outbounds the OVD of its RPS, such part is clipped and shall not be assigned to RPS. The presentation of such PVD may begin or end at the middle of the PVD corresponding to the edge of parent OVD.
+- 12) The binding of the PVD of the rt-component to its RPS is effective until it is explicitly removed.
+
+NOTE – PVD positions are used to realise temporal composition. As the position is set to the rt-composite object of the RPS, the rt-component is automatically started each time the rt-composite is made “running”.
+
+![Diagram illustrating Forward presentation. A horizontal timeline starts at 0 and ends at OD. A dashed vertical line marks the 'Initial temporal position'. A solid vertical line marks the 'Terminal temporal position'. A double-headed arrow below the timeline indicates the 'OVD' (Original Video Duration) from the initial position to the terminal position. The reference 'T0827740-97/d052' is at the bottom right.](b361fd4d68b14568a6c5acbcd9bfe8ee_img.jpg)
+
+The diagram shows a horizontal timeline representing temporal composition. It starts at a point labeled '0' and ends at a point labeled 'OD'. A dashed vertical line with a downward arrow is labeled 'Initial temporal position'. A solid vertical line with a downward arrow is labeled 'Terminal temporal position'. A horizontal double-headed arrow below the timeline, spanning from the initial to the terminal position, is labeled 'OVD'. The text 'T0827740-97/d052' is located at the bottom right of the diagram.
+
+Diagram illustrating Forward presentation. A horizontal timeline starts at 0 and ends at OD. A dashed vertical line marks the 'Initial temporal position'. A solid vertical line marks the 'Terminal temporal position'. A double-headed arrow below the timeline indicates the 'OVD' (Original Video Duration) from the initial position to the terminal position. The reference 'T0827740-97/d052' is at the bottom right.
+
+Figure 54/T.171 – Forward presentation
+
+## 50.8 CTP
+
+Each rt-component has a CTP within its OVD interval. Initially, the CTP is set to the initial temporal position of the OVD.
+
+The CTP is affected by a Run action and Stop action as follows:
+
+- 1) After a Run action, the CTP progresses at the current GTF (see 50.9) in the PVD of final OPS-RPS chains until the terminal temporal position of the PVD is reached or a Stop action is performed.
+
+### NOTES
+
+- 1 – If the GTF is equal to 0, the CTP remains at its current position.
+- 2 – “Progress” means “increment” if the GTF is positive. It means “decrement” if the GTF is negative.
+- 2) After a Run action, if the CTP passes the end point of the OD, the CTP is set to zero, i.e. the start point of OD (see Figure 55).
+- 3) After a Run action, if the CTP passes the zero point (i.e. the start point of OD), the CTP is set to the end point of the OD (see Figure 56).
+- 4) After a Stop action, the CTP remains at its current value.
+
+![Diagram illustrating Forward presentation with wrap-around. A horizontal line represents the OVD interval from 0 to OD. The 'Initial temporal position' is marked near OD, and the 'Terminal temporal position' is marked near 0. A dashed arrow shows the progression from the initial position to the terminal position, wrapping around from the end of the OVD to the beginning. The label 'OVD' is centered below the line, and 'T0827750-97/d053' is at the bottom right.](ef86416097668984aee7611317e77bb9_img.jpg)
+
+Diagram illustrating Forward presentation with wrap-around. The OVD interval is shown as a horizontal line from 0 to OD. The Initial temporal position is marked near OD, and the Terminal temporal position is marked near 0. A dashed arrow indicates the progression from the initial position to the terminal position, wrapping around from the end of the OVD to the beginning. The label 'OVD' is centered below the line, and 'T0827750-97/d053' is at the bottom right.
+
+Diagram illustrating Forward presentation with wrap-around. A horizontal line represents the OVD interval from 0 to OD. The 'Initial temporal position' is marked near OD, and the 'Terminal temporal position' is marked near 0. A dashed arrow shows the progression from the initial position to the terminal position, wrapping around from the end of the OVD to the beginning. The label 'OVD' is centered below the line, and 'T0827750-97/d053' is at the bottom right.
+
+**Figure 55/T.171 – Forward presentation with wrap-around**
+
+![Diagram illustrating Backward presentation with wrap-around. A horizontal line represents the OVD interval from 0 to OD. The 'Initial temporal position' is marked near 0, and the 'Terminal temporal position' is marked near OD. A dashed arrow shows the progression from the initial position to the terminal position, wrapping around from the beginning of the OVD to the end. The label 'OVD' is centered below the line, and 'T0827760-97/d054' is at the bottom right.](25560b45ff748b9fc5d85aa004d18aa2_img.jpg)
+
+Diagram illustrating Backward presentation with wrap-around. The OVD interval is shown as a horizontal line from 0 to OD. The Initial temporal position is marked near 0, and the Terminal temporal position is marked near OD. A dashed arrow indicates the progression from the initial position to the terminal position, wrapping around from the beginning of the OVD to the end. The label 'OVD' is centered below the line, and 'T0827760-97/d054' is at the bottom right.
+
+Diagram illustrating Backward presentation with wrap-around. A horizontal line represents the OVD interval from 0 to OD. The 'Initial temporal position' is marked near 0, and the 'Terminal temporal position' is marked near OD. A dashed arrow shows the progression from the initial position to the terminal position, wrapping around from the beginning of the OVD to the end. The label 'OVD' is centered below the line, and 'T0827760-97/d054' is at the bottom right.
+
+**Figure 56/T.171 – Backward presentation with wrap-around**
+
+## 50.9 GTF
+
+The presentation speed of an rt-component is controlled by its current GTF. The GTF defines the number of RGTU corresponding to one OGTU. A GTF value may be negative to express that the playback direction is reverse. In this case, the CTP of an rt-component is progressed reversibly if it is running.
+
+NOTE – Channels do not have GTFs. No temporal factors are available for the mapping to CPS.
+
+## 50.10 Timestone Status
+
+A timestone is a marker in a temporal position. An rt-component may have any number of timestones defined along its OD. A timestone is composed of:
+
+- A timestone identifier: A generic integer that value is provided by the author. The value 0 is reserved to express that no timestone has ever encountered for the target.
+- A temporal position: Expressed in OGTU within the interval of the OD.
+
+As a timestone contains a temporal position and is defined in the OPS, the perception of this point may differ on the RPS T-axis.
+
+NOTE – For example, if the GTF value is doubled, the PVD in the RPS is halved and the CTP progresses in double speed. In this case, the temporal position of OPS looks closer in the RPS.
+
+Timestones are crossed by the CTP when an rt-component is running. The timestone status is defined as a last timestone identifier crossed by the CTP.
+
+Initially, the timestone status is 0, and no timestones are provided on an rt-component. Timestones are specified by the author using a Set Timestones action.
+
+## 50.11 Timestone ID
+
+A generic integer. The value 0 is reserved.
+
+## 50.12 Expected OVD Result
+
+Choice among “initial-temporal-position”, “terminal-temporal-position” or “duration”.
+
+## 50.13 Expected PVD Result
+
+Choice among “initial-temporal-position”, “terminal-temporal-position” or “duration”.
+
+## 50.14 Actions to change the behaviour
+
+This Recommendation defines means to modify this behaviour by the use of the following actions:
+
+- Set OVD action (see 50.14.1);
+- Set CTP action (see 50.14.2);
+- Set Temporal Termination action (see 50.14.3);
+- Set PVD Position action (see 50.14.4);
+- Set GTF action (see 50.14.5);
+- Set Timestones action (see 50.14.6).
+
+### 50.14.1 Set OVD action
+
+This action specifies an OVD within an OD.
+
+This action has the following parameters:
+
+- Set of Rt-Component Target Param.
+- Initial Point Spec Param;
+- Terminal Point Spec Param.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+#### 50.14.1.1 Set OVD effect
+
+The initial temporal position and the terminal temporal position may be specified as follows:
+
+- 1) By an absolute value in the OGTU of the target.
+- 2) By a relative value relatively to the OD. The value is interpreted as  $OD \times (\text{specified value})$ . If the calculated value is outside the OD, the value is set to 0 (if negative) or OD (if greater than OD). If the specified value does not indicate an addressable point, this value shall be rounded.
+
+If the target is running, there may be a user effect associated, i.e. the perception duration may be shortened or extended.
+
+#### 50.14.1.2 Set OVD additional error conditions
+
+- if one of the targets is not an rt-component in R2, R3 or R3.TD, this action is ignored for that target;
+- if one of the temporal position parameters specified as an absolute point is not in the interval (0, OD), this action is ignored for the whole target set.
+
+#### 50.14.2 Set CTP action
+
+This action specifies the CTP within the OVD.
+
+This action has the following parameters:
+
+- Set of Rt-Component Target Param.
+- Current Point Spec Param.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+#### 50.14.2.1 Set CTP effect
+
+The CTP may be specified as follows:
+
+- 1) If the position is specified as an absolute value, the CTP is set to this value.
+- 2) If the position is specified as a relative value, this value is interpreted as a relative value to the OVD of the target. The CTP is set to  $OVD \times (\text{specified value})$ .
+- 3) If the position is specified as an original point factor, the CTP is set to (initial temporal position)  $\times$  (specified value).
+- 4) Otherwise (the position is specified as a current point factor), the CTP is set to  $CTP \times (\text{specified value})$ .
+- 5) In above cases, if the calculated value is outside the OVD, the value is set to the nearest point within the OVD.
+- 6) If the specified point does not indicate an addressable point, this value shall be rounded.
+
+If the target is running, there may be a user effect associated. If the playback is forward and the CTP is set to a smaller one, this has the effect of replaying a part of the target. If the playback is forward and the CTP is set to a greater one, this has the effect of skipping a part of the target.
+
+A Set CTP action does not affect any timestamp status. If the target is replayed, a previously passed timestamp may be crossed again. If the target is skipped forward, timestamps within this skipped part are not crossed.
+
+#### 50.14.2.2 Set CTP additional error conditions
+
+- if one of the targets is not an rt-component in R2, R3 or R3.TD, this action is ignored for that target;
+- if the temporal position parameter specified as an absolute point is not in the interval of OVD, this action is ignored for the whole target set;
+- if one of the targets is assigned to its RPS by a Set PVD Position action, this action is ignored for that target.
+
+### 50.14.3 Set Temporal Termination action
+
+This action specifies the type of temporal termination if the CTP reaches the end of presentation.
+
+This action has the following parameters:
+
+- Set of Rt-Target Param.
+- Temporal Termination Param.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+#### 50.14.3.1 Set Temporal Termination effect
+
+This action sets the temporal termination of the target. If the target is at the end of the presentation and the running status is “running”, there may be a user effect changing the previous temporal termination presentation to the specified new one.
+
+#### 50.14.3.2 Set Temporal Termination additional error conditions
+
+- If one of the targets is not an rt-component in R2, R3 or R3.TD, this action is ignored for that target.
+
+### 50.14.4 Set PVD Position action
+
+This action specifies the position within the OD of the parent where to attach the PVD of a socket.
+
+This action has the following parameters:
+
+- Set of Socket Target Param.
+- Temporal Position Param: Specifies temporal position either by an absolute value along a temporal axis or a relative value against a temporal duration.
+
+This action may be targeted during the period R2.
+
+#### 50.14.4.1 Set PVD Position effect
+
+The PVD position may be specified as follows:
+
+- 1) By an absolute value in the RGTU of the target.
+- 2) By a relative value relatively to the OD of the parent. The value is interpreted as  $OD \times (\text{specified value})$ . If the calculated value is outside the OD of the parent, the value is set to 0 (if negative) or OD (if greater than OD). If the specified point does not indicate an addressable point, this value shall be rounded.
+
+If the parent of the target is running, there may be a user effect associated. After performing this action, if the CTP of the parent enters the PVD of the target, this target is to be played.
+
+#### 50.14.4.2 Set PVD Position additional error conditions
+
+- if one of the targets is not an rt-component in R2, this action is ignored for that target;
+- if the temporal position parameter specified as an absolute point is not in the interval of the parent OD, this action is ignored for the whole target set;
+- if the temporal position parameter specified as a relative point is not in the interval of the parent OD, this action is ignored for the whole target set;
+- if the target does not have a PRPS, this action is ignored.
+
+### 50.14.5 Set GTF action
+
+This action defines the presentation speed of an rt-component.
+
+This action has the following parameters:
+
+- Set of Rt-Component Target Param.
+- GTF Param: Generic ratio or default-GF.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+#### 50.14.5.1 Set GTF effect
+
+The GTF value of the target is set to the specified value.
+
+If the target is running, there may be a user effect associated with this action. That is the change of the target presentation speed.
+
+#### 50.14.5.2 Set GTF additional error conditions
+
+- If one of the targets is not rt-component in R2, R3 or R3.TD, this action is ignored for that target.
+
+#### 50.14.6 Set Timestones action
+
+This action specifies a set of timestones to be set within the OD of the target.
+
+This action has the following parameters:
+
+- Set of Rt-Component Target Param.
+- Set of Timestone Spec Param: Generic ratio or default-GF.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+##### 50.14.6.1 Set Timestones action effect
+
+The effect of this action is as follows:
+
+- 1) According to the update command within the timestone specification parameter, specified timestones are added, removed or replaced.
+- 2) If an absolute value is specified as a timestone position, the value is interpreted as the position in the OD.
+- 3) If a relative value is specified as a timestone position, the value,  $OD \times (\text{specified value})$ , is calculated and used.
+- 4) A same timestone may be repeated several times or infinitely. This is specified by the “number of repetitions”. Number of repetitions is valid only for “add” command and ignored for other commands. If the number of repetitions is specified greater than 1, this means the corresponding timestones should be repeated every specified time position as many as specified. For example, Set Timestones (target, ((1, 5, 10), add)) action repeats ten times to add timestone 1 every 5 GTUs from the beginning of the OD.
+
+##### 50.14.6.2 Set Timestones additional error conditions
+
+- If one of the targets is not rt-component in R2, R3 or R3.TD, this action is ignored for that target.
+- If the timestone position parameter is not in the interval of the OD, this timestone is ignored. All other timestones are applied.
+- If the number of repetitions is less than 1 with “add” command, this timestone is ignored. All other timestones are applied.
+
+### 50.15 Actions to retrieve the behaviour
+
+This Recommendation defines means to get this behaviour by the use of the following actions:
+
+- Get OD action (see 50.15.1);
+- Get POD action (see 50.15.2);
+- Get OVD action (see 50.15.3);
+- Get PVD action (see 50.15.4);
+- Get CTP action (see 50.15.5);
+
+- Get Temporal Termination action (see 50.15.6);
+- Get PVD Position action (see 50.15.7);
+- Get GTF action (see 50.15.8);
+- Get Timestone Status action (see 50.15.9).
+
+#### **50.15.1 Get OD action**
+
+This action retrieves the OD of the target expressed in OGTU.
+
+This action has the following parameter:
+
+- Rt-Component Target Param.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+##### **50.15.1.1 Get OD action effect**
+
+The MHEG effect of this action is to retrieve the OD value of the target expressed in OGTU.
+
+##### **50.15.1.2 Get OD additional error conditions**
+
+- the target addresses multiple entities, e.g. use of an alias which addresses a list of targets, or use of the “\*” wildcard instead of a given rt-component number, or use of children or descendants tails, the action is ignored for that target;
+- if the target is not an rt-component, the action is ignored for that target;
+- if the target is not accessible, e.g. the reference cannot be solved, the action is ignored for that target;
+- if one of the targets is not an rt-component in R2, R3 or R3.TD, this action is ignored for that target.
+
+#### **50.15.2 Get POD action**
+
+This action retrieves the POD of the target expressed in RGTU.
+
+This action has the following parameter:
+
+- Rt-Component Target Param.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+##### **50.15.2.1 Get POD action effect**
+
+The MHEG effect of this action is to retrieve the POD value of the target expressed in RGTU.
+
+##### **50.15.2.2 Get POD additional error conditions**
+
+- the target addresses multiple entities, e.g. use of an alias which addresses a list of targets, or use of the “\*” wildcard instead of a given rt-component number, or use of children or descendants tails, the action is ignored for that target;
+- if the target is not an rt-component, the action is ignored for that target;
+- if the target is not accessible, e.g. the reference cannot be solved, the action is ignored for that target;
+- if one of the targets is not an rt-component in R2, R3 or R3.TD, this action is ignored for that target.
+
+#### **50.15.3 Get OVD action**
+
+This action retrieves the OVD of the target expressed in OGTU.
+
+This action has the following parameters:
+
+- Rt-Component Target Param.
+- Expected OVD Result Param: Generic ratio or default-GF.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+### 50.15.3.1 Get OVD action effect
+
+The MHEG effect of this action is to retrieve the OVD value of the target expressed in OG TU as follows:
+
+- 1) if the expected OVD result parameter is “initial-temporal position”, this action retrieves the initial temporal position of the OVD;
+- 2) if the expected OVD result parameter is “terminal temporal position”, this action retrieves the terminal temporal position of the OVD;
+- 3) otherwise (the expected OVD result parameter is “duration”), this action retrieves the duration of the OVD.
+
+### 50.15.3.2 Get OVD additional error conditions
+
+- the target addresses multiple entities, e.g. use of an alias which addresses a list of targets, or use of the “\*” wildcard instead of a given rt-component number, or use of children or descendants tails, the action is ignored for that target;
+- if the target is not an rt-component, the action is ignored for that target;
+- if the target is not accessible, e.g. the reference cannot be solved, the action is ignored for that target;
+- if one of the targets is not an rt-component in R2, R3 or R3.TD, this action is ignored for that target.
+
+### 50.15.4 Get PVD action
+
+This action retrieves the PVD of the target expressed in RG TU.
+
+This action has the following parameters:
+
+- Rt-Component Target Param.
+- Expected PVD Result Param: Generic ratio or default-GF.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+#### 50.15.4.1 Get PVD action effect
+
+The MHEG effect of this action is to retrieve the PVD value of the target expressed in RG TU as follows:
+
+- 1) if the expected PVD result parameter is “initial-temporal position”, this action retrieves the initial temporal position of the PVD;
+- 2) if the expected PVD result parameter is “terminal temporal position”, this action retrieves the terminal temporal position of the PVD;
+- 3) otherwise (the expected PVD result parameter is “duration”), this action retrieves the duration of the PVD.
+
+#### 50.15.4.2 Get PVD additional error conditions
+
+- the target addresses multiple entities, e.g. use of an alias which addresses a list of targets, or use of the “\*” wildcard instead of a given rt-component number, or use of children or descendants tails, the action is ignored for that target;
+- if the target is not an rt-component, the action is ignored for that target;
+- if the target is not accessible, e.g. the reference cannot be solved, the action is ignored for that target.
+
+### 50.15.5 Get CTP action
+
+This action retrieves the CTP value of the target.
+
+This action has the following parameter:
+
+- Rt-Component Target Param.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+#### **50.15.5.1 Get CTP action effect**
+
+The MHEG effect of this action is to retrieve the CTP value of the target. This action evaluates a temporal position expressed in OGTU.
+
+#### **50.15.5.2 Get CTP additional error conditions**
+
+- the target addresses multiple entities, e.g. use of an alias which addresses a list of targets, or use of the “\*” wildcard instead of a given rt-component number, or use of children or descendants tails, the action is ignored for that target;
+- if the target is not an rt-component, the action is ignored for that target;
+- if the target is not accessible, e.g. the reference cannot be solved, the action is ignored for that target;
+- if one of the targets is not an rt-component in R2, R3 or R3.TD, this action is ignored for that target;
+- if a target is positioned to its PRPS by a Set PVD Position action, this action returns “undefined” for that target.
+
+#### **50.15.6 Get Temporal Termination action**
+
+This action retrieves the temporal termination value of the target.
+
+This action has the following parameter:
+
+- Rt-Component Target Param.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+##### **50.15.6.1 Get Temporal Termination action effect**
+
+The MHEG effect of this action is to retrieve the temporal termination value of the target, that is “freeze” or “stop”.
+
+##### **50.15.6.2 Get Temporal Termination additional error conditions**
+
+- the target addresses multiple entities, e.g. use of an alias which addresses a list of targets, or use of the “\*” wildcard instead of a given rt-component number, or use of children or descendants tails, the action is ignored for that target;
+- if the target is not an rt-component, the action is ignored for that target;
+- if the target is not accessible, e.g. the reference cannot be solved, the action is ignored for that target;
+- if one of the targets is not an rt-component in R2, R3 or R3.TD, this action is ignored for that target.
+
+#### **50.15.7 Get PVD Position action**
+
+This action retrieves the PVD position value of the target within its PRPS.
+
+This action has the following parameter:
+
+- Rt-Component Target Param.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+##### **50.15.7.1 Get PVD Position action effect**
+
+The MHEG effect of this action is to retrieve the PVD position value of the target within its PRPS. This action evaluates a temporal position expressed in RGTU.
+
+##### **50.15.7.2 Get PVD Position additional error conditions**
+
+- the target addresses multiple entities, e.g. use of an alias which addresses a list of targets, or use of the “\*” wildcard instead of a given rt-component number, or use of children or descendants tails, the action is ignored for that target;
+- if the target is not an rt-component, the action is ignored for that target;
+
+- if the target is not accessible, e.g. the reference cannot be solved, the action is ignored for that target;
+- if one of the targets is not an rt-component in R2, R3 or R3.TD, this action is ignored for that target;
+- if the target is not positioned to its PRPS, this action returns “undefined”.
+
+### **50.15.8 Get GTF action**
+
+This action retrieves the GTF value of the target.
+
+This action has the following parameter:
+
+- Rt-Component Target Param.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+#### **50.15.8.1 Get GTF action effect**
+
+The MHEG effect of this action is to retrieve the GTF value of the target. This action evaluates a generic ratio.
+
+#### **50.15.8.2 Get GTF additional error conditions**
+
+- the target addresses multiple entities, e.g. use of an alias which addresses a list of targets, or use of the “\*” wildcard instead of a given rt-component number, or use of children or descendants tails, the action is ignored for that target;
+- if the target is not an rt-component, the action is ignored for that target;
+- if the target is not accessible, e.g. the reference cannot be solved, the action is ignored for that target;
+- if one of the targets is not an rt-component in R2, R3 or R3.TD, this action is ignored for that target.
+
+### **50.15.9 Get Timestone Status action**
+
+This action retrieves the timestone status value of the target.
+
+This action has the following parameter:
+
+- Rt-Component Target Param.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+#### **50.15.9.1 Get Timestone Status action effect**
+
+The MHEG effect of this action is to retrieve the timestone status value of the target. This action evaluates an integer corresponding to the timestone identifier of the last timestone crossed by the CTP. If no timestones have ever been crossed, 0 is returned.
+
+#### **50.15.9.2 Get Timestone Status additional error conditions**
+
+- the target addresses multiple entities, e.g. use of an alias which addresses a list of targets, or use of the “\*” wildcard instead of a given rt-component number, or use of children or descendants tails, the action is ignored for that target;
+- if the target is not an rt-component, the action is ignored for that target;
+- if the target is not accessible, e.g. the reference cannot be solved, the action is ignored for that target;
+- if one of the targets is not an rt-component in R2, R3 or R3.TD, this action is ignored for that target.
+
+## 51 Rt-Components Spatial Behaviour
+
+The behaviour describes presentability in space of rt-components for the MHEG engine.
+
+### 51.1 Behaviour attributes and statuses
+
+This behaviour is expressed using the following attributes or statuses:
+
+- OS (see 51.2),
+- POS (see 51.3),
+- Aspect Ratio (see 51.4),
+- Resizing Strategy (see 51.5),
+- OVS (see 51.6),
+- OAP (see 51.7),
+- OVS Position (see 51.8),
+- PVS (see 51.9),
+- OVS Proj Strategy (see 51.10),
+- PAP (see 51.11),
+- PVS Position (see 51.12),
+- GSF (see 51.13),
+- Spatial Control (see 51.14),
+- User Spatial Control (see 51.15),
+- Expected Axis Result Param (see 51.16),
+- Point Type Param (see 51.17).
+
+### 51.2 OS
+
+Each rt-component and each channel has an assigned OS that is defined in its OPS. Therefore, the OS is measured in the OGSU (see Original presentation space for initialisation of each OS).
+
+Each OS for an rt-content is set only once and shall not be changed. However, the OS of an rt-composite may be changed resizing strategy (see 51.5).
+
+### 51.3 POS
+
+Each OS of an rt-component is projected to its RPS. The projection is called POS. Therefore, the POS is measured in the RGSU. It is calculated as  $POS = OS \times GSF$  on each axis.
+
+### 51.4 Aspect Ratio
+
+The aspect ratio is the ratio among the width, the height and the depth along the spatial axes.
+
+The projection of OS is controlled by GSF and the relationship,  $POS = OS \times GSF$ , is always respected. However, in order to preserve the aspect ratio of an rt-component, how to fill the POS is specified independently of the GSF. The value of the aspect ratio attribute is either “preserved” or “not-preserved”. This attribute controls the aspect ratio preserving only for one OS-POS mapping. If the rt-component is to be presented in a channel preserving the aspect ratio, every aspect ratio attribute through the OPS-RPS chains from the rt-component to the channel should be set to “preserved”.
+
+For preserving the aspect ratio, the following applies:
+
+- “Preserved”: The rt-component is scaled preserving the aspect ratio. This scaling is independent of the assigned GSF, and the rt-component is scaled so that at least one of the width, height or depth becomes to fit to the POS. Then, the POS is filled with this scaled rt-component. The scaled rt-component may not entirely fit the POS, i.e. some portion of the POS may not be filled by the scaled rt-component. If on a given axis, the scaled rt-component is smaller than the size of the POS, the scaled rt-component is centred on the interval of such axis. How the portions of POS that are not covered by the scaled rt-component are filled is either defined by a (registered) presentation style or implementation dependent.
+- “Not preserved”: The POS should be filled entirely with the rt-component taking into account the GSF on each axis.
+
+Initially, the aspect ratio attribute value is set to “preserved”.
+
+NOTES
+
+1 – The POS are not affected by the aspect ratio attribute value, i.e. the aspect ratio of the OS and the aspect ratio of the POS may be different on each axis even if the aspect ratio attribute value is “preserved”.
+
+2 – If an axis has a zero value in the OS, such axis is not taken into account in the scaling of the rt-component.
+
+## **51.5 Resizing Strategy**
+
+The OS for each rt-composite may be modified in order to accommodate the modification in size and position of the PVSs of the child rt-components. This is controlled by a resizing strategy attribute. One of the following three attribute values may be set to an rt-composite:
+
+- “Fixed”: The OS of an rt-composite should remain as the initial size of the OS. The OS cannot be changed until another attribute value is assigned. If this attribute is changed from another value to “fixed” and the previous OS is different from the initial size due to the resizing at that time, the OS should be reset to the initial size.
+- “Minimum”: The OS of an rt-composite should have a minimum size that is enough to contain all the PVSs of the child rt-components and greater than or equal to the initial OS of the target on each axis.
+- “Grows only”: The OS of an rt-composite should not be reduced. If a part of an rt-component PVS is positioned outside the OS, the OS becomes the minimum size on each axis that is big enough to include every PVS. However, it is never reduced if the OS is bigger than the actual minimum size enough for every PVS.
+
+The initial value is “fixed”.
+
+The portions of PVSs that outbound the OS of an rt-composite are clipped. However, the values of such PVSs does not change. This situation happens only if the value is “fixed”.
+
+If some portions of a PVS outbound the OS of an rt-composite and its resizing strategy is “minimum” or “grows only”, the PAP position of the PVS may be changed due to the resizing. The MHEG engine should take into account this change.
+
+NOTES
+
+1 – The values of such PVSs remain the same because these rt-components may be assigned later to another RPS or may become completely perceivable due to the change of the parent OS.
+
+2 – The size considerations described above should be done independently on each axis. For example, in the case of “minimum”, if the initial value of the rt-composite OS is  $x = 10$  and  $y = 10$ , and the rt-composite has one rt-component whose PVS is  $x = 5$  and  $y = 20$ , the OS of the rt-composite becomes  $x = 10$  and  $y = 20$ .
+
+If the aspect ratio attribute is set to “preserved” for an rt-composite, the size of the data information may be a subset of the OS in order to preserve the aspect ratio.
+
+## 51.6 OVS
+
+The OVS is a subset of the OS for an rt-component, and is positioned relatively to the OS. The portion of the OS that fits within the OVS is to be presented to the user. The portion of the OS that is outside of the OVS is clipped. If the OVS exceeds the limits of the OS, the exceeding portion of the OVS is filled with a background which depends on the implementation or is specified by an extensibility facility.
+
+The OVS may be specified by one of the following methods (see also OVS Proj Strategy):
+
+- 1) Directly defined in the OPS: The OVS is defined within the OPS by a Set OVS action with OVS Proj Strategy attribute as “calculated”. In this case, a change of the rt-component GSF affects the PVS because the OVS looks like a constant [ $PVS = OVS (\text{constant}) \times GSF$ ]. However, this change does not affect the PAP and the PVS position.
+- 2) Indirectly defined in the RPS: The PVS is defined within the RPS, rather than the OVS, by a Set OVS action with OVS Proj Strategy attribute as “fixed”. The OVS is automatically calculated by  $OVS = PVS / GSF$  on each axis. In this case, the OVS may change dynamically depending on the GSF value. And a change of the rt-component GTF does not affect the PVS because the PVS looks like a constant [ $PVS (\text{constant}) = OVS \times GSF$ ]. This GTF change does not affect the OAP (see 51.7) and the OVS position (see 51.8) to the OVS, but the OVS.
+
+NOTE 1 – However, it affects some part of the OS becoming visible.
+
+The OVS is initialised to the size of the corresponding OS in the OPS using OGSU.
+
+NOTE 2 – Typically, the OVS directly defined in the OPS is used to perform real scaling of an rt-component. Therefore, the PVS and the POS are varied depending on the GTF of the rt-component.
+
+NOTE 3 – Typically, the OVS indirectly defined in the RPS is used to scale only the OS of an rt-component that is projected and perceived through the constant PVS.
+
+## 51.7 OAP
+
+An OAP defines an attachment position within the OVS. This attachment position with the OVS position is used to position the OVS within its OS. Initially, the OAP is set to the origin of the OVS, i.e. (0, 0, 0).
+
+The OAP may be specified by an absolute position within the OVS, or a relative position relatively to the OVS origin expressed by a generic ratio.
+
+If an OVS is specified indirectly by a Set OVS action with OVS Proj Strategy attribute as “fixed”, the OVS may be dynamically changed depending on the corresponding GSF value. In this case, the OAP shall not be affected by the changing OVS. It should keep the current value. If the value is specified by an absolute one, it should be kept. If the value is specified by a relative one, the relative value should be kept.
+
+## 51.8 OVS Position
+
+An OVS position defines a position relatively to the origin of the OS where the corresponding OAP should be positioned. The OVS position with the OAP is used to position the OVS within its OS. Initially, the OVS position is set to the origin of the OS, i.e. (0, 0, 0).
+
+The OVS may be specified by an absolute position within the OS, or a relative position relatively to the OS expressed by a generic ratio.
+
+If an OVS is specified indirectly by a Set OVS action with OVS Proj Strategy attribute as “fixed”, the OVS may be dynamically changed depending on the corresponding GSF value. In this case, the OVS position should not be affected by the changing OVS. It should keep the current value. If the value is specified by an absolute value, it should be kept. If the value is specified by a relative one, it should be kept.
+
+## 51.9 PVS
+
+The PVS is a projection of the OVS of an rt-component to its RPS, and is positioned relatively to the OS of the PRS.
+
+The PVS may be specified by one of the following methods:
+
+- Directly defined in the RPS: The PVS is defined within the RPS by a Set OVS action with OVS Proj Strategy attribute as “fixed”. In this case, the PVS is constant and the corresponding OVS is automatically calculated.
+- Indirectly defined in the OPS: The OVS is defined within the OPS by a Set OVS action with OVS Proj Strategy attribute as “calculated”, a Set OAP action and a Set OVS Position action. In this case, the PVS is calculated according to the GSF value and the corresponding OVS is constant.
+
+The PVS is initialised by the OVS initial value and the GSF initial value.
+
+## 51.10 OVS Proj Strategy
+
+Each rt-component has an OVS Proj Strategy attribute. This attribute defines how to project an OVS to the corresponding PVS. The relationship of the OVS and the PVS,  $PVS = OVS \times GSF$  on each axis, is always respected.
+
+This attribute has either “fixed” or “calculated”. The following applies:
+
+- if the OVS Proj Strategy is equal to “fixed”, the PVS is always fixed;
+- if the OVS changes, the GSF is recalculated;
+- if the GSF changes, the OVS is recalculated;
+- otherwise (“calculated”), the PVS is always calculated;
+- if the OVS changes, the PVS is recalculated;
+- if the GSF changes, the PVS is recalculated.
+
+## 51.11 PAP
+
+A PAP defines an attachment position within the PVS. This attachment position with the PVS position is used to position the PVS within the OS of the RPS. Initially, the PAP is set to the origin of the PVS, i.e. (0, 0, 0).
+
+The PAP may be specified as an absolute position within the PVS, or a relative position relatively to the PVS origin expressed by a generic ratio.
+
+## 51.12 PVS Position
+
+A PVS position defines a position relatively to the origin of the OS of the RPS or to another PVS within the same RPS, where the corresponding PAP should be positioned. The PVS position with the PAP is used to position the PVS within the OS of the RPS. Initially, the PVS position is set to the origin of the OS of RPS, i.e. (0, 0, 0).
+
+The PVS position may be specified by an absolute position within the OS, or a relative position relatively to the OS expressed by a generic ratio.
+
+## 51.13 GSF
+
+The projection of the OPS to RPS is controlled by its GSF value. The GSF defines the number of RGSU corresponding to one OGSU for each axis.
+
+## 51.14 Spatial Control
+
+Moving, resizing, scaling and scrolling an rt-component may be allowed or not to a user independently of the elementary action controls. This attribute indicates that those functions are allowed or not with the combination of the user spatial control attribute value. The spatial control attribute has one of the following values:
+
+- “moving”: indicating the move of the PVS.
+- “resizing”: indicating the resize of the PVS.
+- “scaling”: indicating the scale of the OS.
+- “scrolling”: indicating the scroll of the OS.
+
+NOTE 1 – Scrolling may be allowed for each rt-component and for the parent of the rt-components independently. The scrolling always refers to the PS of the rt-component.
+
+Initially, those user controls are “not allowed”.
+
+It is the responsibility of the MHEG engine with the user interface to make the user knowledgeable of being allowed to perform a given control and to provide the necessary supports (e.g. scroll bars, resizing handles).
+
+For example, if the scrolling is allowed to the rt-component, a mechanism is to be offered by the MHEG engine to operate a scrolling of the OS as perceived through the PVS. It is the responsibility of the MHEG engine to decide which look-and-feel has to be adopted for the scroll mechanism and to decide whether such a mechanism has to be attached to the rt-component.
+
+If the user control is not allowed, it is the responsibility of the MHEG engine to make the user knowledgeable about that (e.g. scroll bars are not displayed, or pressing scroll keys produce a beep).
+
+NOTE 2 – Typically, a scroll mechanism attached to an rt-component may be implemented through a couple of scroll bars.
+
+NOTE 3 – Typically, a scroll mechanism not attached to an rt-component may be implemented with keys or arrows.
+
+## 51.15 User Spatial Control
+
+This attribute is used with the spatial control attributes to indicate whether a certain user spatial control is allowed or not.
+
+## 51.16 Expected Axis Result Param
+
+Choice among “x”, “y”, “z” or “xyz”.
+
+## 51.17 Point Type Param
+
+Choice between “absolute” and “relative”.
+
+## 51.18 Actions to change the behaviour
+
+This Recommendation defines means to modify this behaviour by the use of the following actions:
+
+- Set Aspect Ratio action (see 51.18.1);
+- Set Resizing Strategy action (see 51.18.2);
+- Set OVS Proj Strategy action (see 51.18.3);
+- Set OVS action (see 51.18.4);
+- Set OAP action (see 51.18.5);
+- Set OVS Position action (see 51.18.6);
+- Set PAP action (see 51.18.7);
+- Set PVS Position action (see 51.18.8);
+- Set GSF action (see 51.18.9);
+- Set User Spatial Control action (see 51.18.10).
+
+### **51.18.1 Set Aspect Ratio action**
+
+This action specifies whether the ratio between the OS in the OGSU and the scaled rt-component in the POS of the RGSU is to be preserved for each axis in performing projection of an rt-component OS to the POS.
+
+This action has the following parameters:
+
+- Set of Rt-Component Target Param;
+- Aspect Ratio Param.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+#### **51.18.1.1 Set Aspect Ratio action effect**
+
+The action effect of this action is as follows:
+
+- 1) if the aspect ratio parameter is “preserved”, the aspect ratio of the scaled rt-component should be preserved;
+- 2) otherwise, the rt-component should fit the POS entirely.
+
+This effect continues until the target is destroyed or this action is targeted again with a different value. The continuous effect means that the scaled rt-component within the POS should be recalculated each time the POS is changed in order to maintain the aspect ratio preserved or in order to fit the POS.
+
+If the target is running, there is a user effect associated, i.e. this area where the data information is presented may be stretched to fit the entire POS or squeezed to a subset of it.
+
+#### **51.18.1.2 Set Aspect Ratio additional error conditions**
+
+- If one of the targets is not an rt-component in R2, R3 or R3.TD, this action is ignored for that target.
+
+### **51.18.2 Set Resizing Strategy action**
+
+This action specifies the OS resizing strategy of an rt-composite regarding the modification of the PVSs of the child rt-components positioned in the OS of the rt-composite.
+
+This action has the following parameters:
+
+- Set of Rt-Composite Target Param;
+- Resizing Strategy Param.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+#### **51.18.2.1 Set Resizing Strategy effect**
+
+The action effect is as follows:
+
+- 1) depending on the resizing strategy parameter value (“fixed”, “minimum” or “grows only”), the OS of the target rt-composite may be changed;
+- 2) if “minimum” or “grows only” is assigned, the OS of the rt-composite is recalculated each time the child PVSs are modified and each time the OS does not fit the specified strategy.
+
+This effect continues until the target is destroyed or this action is targeted again with a different value.
+
+#### **51.18.2.2 Set Resizing Strategy additional error conditions**
+
+- If one of the targets is not an rt-component in R2, R3 or R3.TD, this action is ignored for that target.
+
+### **51.18.3 Set OVS Proj Strategy action**
+
+This action set the OVS Proj Strategy to an rt-component.
+
+This action has the following parameters:
+
+- Set of Rt-Component Target Param;
+- OVS Proj Strategy Param.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+#### **51.18.3.1 Set OVS Proj Strategy effect**
+
+The effect of this action is as follows:
+
+- 1) set the OVS Proj Strategy attribute to either “fixed” or “calculated” as specified;
+- 2) if the OVS Proj Strategy attribute is set to “fixed”, the size specification parameter in the Set OVS action is interpreted as RGSU and the Set OVS action sets the PVS;
+- 3) otherwise, the size specification parameter in the Set OVS action is interpreted as OGSU and the Set OVS action sets the OVS directly.
+
+#### **51.18.3.2 Set OVS Proj Strategy additional error conditions**
+
+- If one of the targets is not an rt-component in R2, R3 or R3.TD, this action is ignored for that target.
+
+#### **51.18.4 Set OVS action**
+
+This action sets the OVS directly or indirectly depending on the OVS Proj Strategy attribute of the target.
+
+This action has the following parameters:
+
+- Set of Rt-Component Target Param;
+- Size Spec Param;
+- Transition Duration Param.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+#### **51.18.4.1 Set OVS action effect**
+
+The effect of this action is as follows:
+
+- 1) The size specification parameter may be specified by an absolute value expressed in GSU or a relative value expressed in generic ratio.
+- 2) If the OVS Proj Strategy attribute is equal to “fixed”:
+  - a) The specified values in the size specification parameter are interpreted as in the RPS of the target. Absolute values are considered as expressed in RGSU. Relative values are considered as expressed relatively to the POS of the target.
+  - b) The PVS of the target is directly defined by the interpreted values.
+  - c) The OVS is automatically calculated by the current GSF of the target.
+  - d) If the OVS or the GSU is changed after applying this action, the new GSU or the new OVS is recalculated and is set in order to hold  $PVS = OVS \times GSU$  on each axis.
+- 3) Otherwise:
+  - a) The specified values in the size specification parameter are interpreted as in the OPS of the target. Absolute values are considered as expressed in OGSU. Logical values are considered as expressed relatively to the OS of the target.
+  - b) The OVS of the target is directly defined by the interpreted values.
+  - c) The PVS is automatically calculated by the current GSF of the target.
+  - d) If the OVS or the GSU is changed after applying this action, the new PVS is recalculated in order to hold  $PVS = OVS \times GSU$  on each axis.
+
+If a size specification on an axis is omitted, 100% is applied.
+
+If a non-zero transition duration is specified, the OVS or the PVS is gradually changed depending on the OVS Proj Strategy attribute. There is a user effect associated with this action, i.e. the presented content within the PVS is changed gradually or the PVS is changed gradually. The change of the OVS or the PVS does not affect the OAP, the OVS position, the PAP and the PVS position.
+
+#### **51.18.4.2 Set OVS additional error conditions**
+
+- if one of the targets is not an rt-component in R2, R3 or R3.TD, this action is ignored for that target;
+- if a size specification on an axis is omitted, 100% is applied;
+- if the size specification parameter value is a negative value, this action is ignored for the whole target set;
+- if the transition duration is negative, it is set to zero;
+- if an original point factor or a current point factor is used, this action is ignored for all the targets.
+
+#### **51.18.5 Set OAP action**
+
+This action sets the OAP of an rt-component. The OAP shall be specified within the OVS.
+
+This action has the following parameters:
+
+- Set of Rt-Component Target Param.
+- OAP Param: May be specified as an absolute value or a relative value.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+##### **51.18.5.1 Set OAP action effect**
+
+The OAP may be set to absolute values or relative values to the OVS depending on the OAP parameter.
+
+There may be a user effect changing the presenting portion of the OS.
+
+##### **51.18.5.2 Set OAP additional error conditions**
+
+- if one of the targets is not an rt-component in R2, R3 or R3.TD, this action is ignored for that target;
+- if one of the OAP parameters is specified as an absolute value and it is not in the interval (0, OVS) on an axis, this parameter is set to 0;
+- if one of the OAP parameters is specified as a relative value and it is not in the interval (0, 100%) on an axis, this parameter is set to 0%.
+
+#### **51.18.6 Set OVS Position action**
+
+This action specifies the position of the OVS relatively to the OS.
+
+This action has the following parameters:
+
+- Set of Rt-Component Target Param.
+- OVS Position Param: Allows the specification of a macro parameter instead of a specified position value for the OVS relatively to the OS.
+- Transition Duration Param: Allows the specification of a macro parameter instead of a specified position value for the OVS relatively to the OS.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+##### **51.18.6.1 Set OVS Position action effect**
+
+The OVS position may be set to absolute values in the OPS or relative values to the OS depending on the OAP parameter. The effect of this action is as follows:
+
+- Set the OVS position of the target.
+
+There may be a user effect changing the presenting portion of the OS.
+
+If a non-zero transition duration is specified, the OVS position is gradually changed. There is a user effect associated with this action, i.e. the presenting part of the OS is gradually changed. The change of the OVS position does not affect the OAP.
+
+## NOTES
+
+1 – Any values are allowed for the OVS position parameter in absolute values and relative values.
+
+2 – If some portions of the OS are not within the OVS, they are not perceived by the user. Note that the OVS position may position the OVS completely outside the OS. In this case, the entire OS is not perceived.
+
+### 51.18.6.2 Set OVS Position additional error conditions
+
+- if one of the targets is not an rt-component in R2, R3 or R3.TD, this action is ignored for that target;
+- if the transition duration is negative, it is set to zero.
+
+### 51.18.7 Set PAP action
+
+This action sets the PAP of an rt-component. The PAP shall be specified within the PVS.
+
+This action has the following parameters:
+
+- Set of Rt-Component Target Param.
+- PAP Param: May be specified as an absolute value or a relative value.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+#### 51.18.7.1 Set PAP action effect
+
+The PAP may be set to absolute values or relative values to the PVS depending on the PAP parameter. The effect of this action is as follows.
+
+- Set the PAP of the target.
+
+There may be a user effect changing the presenting position within the RPS.
+
+#### 51.18.7.2 Set PAP additional error conditions
+
+- if one of the targets is not an rt-component in R2, R3 or R3.TD, this action is ignored for that target;
+- if one of the PAP parameters is specified as an absolute value and it is not in the interval (0, PVS) on an axis, this parameter is set to 0;
+- if one of the PAP parameters is specified as a relative value and it is not in the interval (0, 100%) on an axis, this parameter is set to 0%.
+
+### 51.18.8 Set PVS Position action
+
+This action specifies the position of the PVS relatively to the OS of the RPS.
+
+This action has the following parameters:
+
+- Set of Rt-Component Target Param.
+- PVS Position Param: May be specified as an absolute value or a relative value.
+- Transition Duration Param: May be specified as an absolute value or a relative value.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+#### 51.18.8.1 Set PVS Position action effect
+
+The PVS position may be set to absolute values in the RPS or relative values to the OS of the RPS depending on the PAP parameter. The effect of this action is as follows:
+
+- Set the PVS position of the target.
+
+There may be a user effect changing the presenting position within the RPS.
+
+If a non-zero transition duration is specified, the PVS position is gradually changed. There is a user effect associated with this action, i.e. the presenting position of the PVS is gradually changed. The change of the PVS position does not affect the PAP.
+
+Any values are allowed for the PVS position parameter in absolute values and relative values.
+
+#### **51.18.8.2 Set PVS Position additional error conditions**
+
+- if one of the targets is not an rt-component in R2, R3 or R3.TD, this action is ignored for that target;
+- if the transition duration is negative, it is set to zero.
+
+#### **51.18.9 Set GSF action**
+
+This action sets the GSF of the target.
+
+This action has the following parameters:
+
+- Set of Rt-Component Target Param.
+- GSF Param: a generic ratio.
+- Transition Duration Param: A generic ratio.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+##### **51.18.9.1 Set GSF action effect**
+
+If the target is running, there may be a user effect. The presenting rt-component may be changed in its size.
+
+If a non-zero transition duration is specified, the size of the target is gradually changing up to the specified GSF.
+
+##### **51.18.9.2 Set GSF additional error conditions**
+
+- if one of the targets is not an rt-component in R2, R3 or R3.TD, this action is ignored for that target;
+- if the GSF parameter value is a negative value, it is set to the value 0;
+- if the transition duration is negative, it is set to zero.
+
+#### **51.18.10 Set User Spatial Control action**
+
+This action specifies whether the user is able to control some rt-component objects according to the specified functions (see 11.3).
+
+This action has the following parameters:
+
+- Set of Rt-Component Target Param.
+- Set of Spatial Control Param: A generic ratio.
+- User Spatial Control Param.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+##### **51.18.10.1 Set User Spatial Control action effect**
+
+The effect of this action is as follows:
+
+- Specified spatial control parameters are set to “allowed” or “not allowed” according to the user spatial control parameter.
+
+If one of the spatial control functions is allowed, the user may interact the rt-component to perform the function.
+
+##### **51.18.10.2 Set User Spatial Control additional error conditions**
+
+- if one of the targets is not an rt-component in R2, R3 or R3.TD, this action is ignored for that target;
+- if the target is not an rt-component, the action is ignored for that target.
+
+## **51.19 Actions to retrieve the behaviour**
+
+This Recommendation defines means to get this behaviour by the use of the following actions:
+
+- Get OS action (see 51.19.1);
+- Get POS action (see 51.19.2);
+- Get Aspect Ratio action (see 51.19.3);
+- Get Resizing Strategy action (see 51.19.4);
+- Get OVS Proj Strategy action (see 51.19.5);
+- Get OVS action (see 51.19.6);
+- Get OAP action (see 51.19.7);
+- Get OVS Position action (see 51.19.8);
+- Get PVS action (see 51.19.9);
+- Get PAP action (see 51.19.10);
+- Get PVS Position action (see 51.19.11);
+- Get GSF action (see 51.19.12);
+- Get User Spatial Control action (see 51.19.13).
+
+### **51.19.1 Get OS action**
+
+This action retrieves the OS of the target.
+
+This action has the following parameters:
+
+- Rt-Component Target Param;
+- Expected Axis Result Param.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+#### **51.19.1.1 Get OS action effect**
+
+The effect of this action is as follows:
+
+- 1) if the expected axis result parameter is “x”, “y” or “z”, the corresponding size of the OS on that axis is returned as a generic integer;
+- 2) otherwise (“xyz”), all the sizes of the OS are returned as a generic list containing three generic integers.
+
+The return value is measured in the OGSU of the target.
+
+#### **51.19.1.2 Get OS additional error conditions**
+
+- the target addresses multiple entities, e.g. use of an alias which addresses a list of targets, or use of the “\*” wildcard instead of a given rt-component number, or use of children or descendants tails, the action is ignored for that target;
+- if the target is not accessible, e.g. the reference cannot be solved, the action is ignored for that target;
+- if the transition duration is negative, it is set to zero.
+
+### **51.19.2 Get POS action**
+
+This action retrieves the POS of the target.
+
+This action has the following parameters:
+
+- Rt-Component Target Param;
+- Expected Axis Result Param.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+#### 51.19.2.1 Get POS action effect
+
+The effect of this action is as follows:
+
+- 1) if the expected axis result parameter is “x”, “y” or “z”, the corresponding size of the POS on that axis is returned as a generic integer;
+- 2) otherwise (“xyz”), all the sizes of the POS are returned as a generic list containing three generic integers.
+
+The return value is measured in the RGSU of the target.
+
+#### 51.19.2.2 Get POS additional error conditions
+
+- the target addresses multiple entities, e.g. use of an alias which addresses a list of targets, or use of the “\*” wildcard instead of a given rt-component number, or use of children or descendants tails, the action is ignored for that target;
+- if the target is not accessible, e.g. the reference cannot be solved, the action is ignored for that target;
+- if the transition duration is negative, it is set to zero.
+
+#### 51.19.3 Get Aspect Ratio action
+
+This action retrieves the aspect ratio attribute of the target.
+
+This action has the following parameter:
+
+- Rt-Component Target Param.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+##### 51.19.3.1 Get Aspect Ratio action effect
+
+This action evaluates the aspect ratio attribute of the target and returns it.
+
+##### 51.19.3.2 Get Aspect Ratio additional error conditions
+
+- the target addresses multiple entities, e.g. use of an alias which addresses a list of targets, or use of the “\*” wildcard instead of a given rt-component number, or use of children or descendants tails, the action is ignored for that target;
+- if the target is not accessible, e.g. the reference cannot be solved, the action is ignored for that target;
+- if the transition duration is negative, it is set to zero.
+
+#### 51.19.4 Get Resizing Strategy action
+
+This action retrieves the resizing strategy attribute of the target.
+
+This action has the following parameter:
+
+- Rt-Composite Target Param.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+##### 51.19.4.1 Get Resizing Strategy action effect
+
+This action evaluates the resizing strategy attribute of the target and returns it.
+
+##### 51.19.4.2 Get Resizing Strategy additional error conditions
+
+- the target addresses multiple entities, e.g. use of an alias which addresses a list of targets, or use of the “\*” wildcard instead of a given rt-component number, or use of children or descendants tails, the action is ignored for that target;
+- if the target is not accessible, e.g. the reference cannot be solved, the action is ignored for that target;
+- if the transition duration is negative, it is set to zero.
+
+### 51.19.5 Get OVS Proj Strategy action
+
+This action retrieves the OVS Proj Strategy attribute of the target.
+
+This action has the following parameter:
+
+- Rt-Component Target Param.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+#### 51.19.5.1 Get OVS Proj Strategy action effect
+
+This action evaluates the OVS Proj Strategy attribute of the target and returns it.
+
+#### 51.19.5.2 Get OVS Proj Strategy additional error conditions
+
+- the target addresses multiple entities, e.g. use of an alias which addresses a list of targets, or use of the “\*” wildcard instead of a given rt-component number, or use of children or descendants tails, the action is ignored for that target;
+- if the target is not accessible, e.g. the reference cannot be solved, the action is ignored for that target;
+- if the transition duration is negative, it is set to zero.
+
+### 51.19.6 Get OVS action
+
+This action retrieves the OVS of the target.
+
+This action has the following parameters:
+
+- Rt-Component Target Param;
+- Point Type Param;
+- Expected Axis Result Param.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+#### 51.19.6.1 Get OVS action effect
+
+The effect of this action is as follows:
+
+- 1) if the point type parameter is “absolute”, this action evaluates the OVS as absolute values in the OGSU, and returns generic integers;
+- 2) otherwise (“relative”), this action evaluates the OVS as relative values relatively to the corresponding OS, and returns generic ratios;
+- 3) if the expected axis result parameter is “x”, “y” or “z”, the corresponding size of the OVS on that axis is returned;
+- 4) otherwise (“xyz”), all the sizes of the OVS are returned as a generic list containing three elements.
+
+#### 51.19.6.2 Get OVS additional error conditions
+
+- the target addresses multiple entities, e.g. use of an alias which addresses a list of targets, or use of the “\*” wildcard instead of a given rt-component number, or use of children or descendants tails, the action is ignored for that target;
+- if the target is not accessible, e.g. the reference cannot be solved, the action is ignored for that target;
+- if the transition duration is negative, it is set to zero.
+
+### 51.19.7 Get OAP action
+
+This action retrieves the OAP of the target.
+
+This action has the following parameters:
+
+- Rt-Component Target Param;
+- Point Type Param;
+- Expected Axis Result Param.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+#### **51.19.7.1 Get OAP action effect**
+
+The effect of this action is as follows:
+
+- 1) if the point type parameter is “absolute”, this action evaluates the OAP as absolute values in the OGSU within the OVS and returns generic integers;
+- 2) otherwise (“relative”), this action evaluates the OAP as relative values relatively to the corresponding OVS and returns generic ratios;
+- 3) if the expected axis result parameter is “x”, “y” or “z”, the corresponding point of the OAP on that axis is returned;
+- 4) otherwise (“xyz”), all the points of the OAP are returned as a list containing three elements.
+
+#### **51.19.7.2 Get OAP additional error conditions**
+
+- the target addresses multiple entities, e.g. use of an alias which addresses a list of targets, or use of the “\*” wildcard instead of a given rt-component number, or use of children or descendants tails, the action is ignored for that target;
+- if the target is not accessible, e.g. the reference cannot be solved, the action is ignored for that target;
+- if the transition duration is negative, it is set to zero.
+
+#### **51.19.8 Get OVS Position action**
+
+This action retrieves the OVS position of the target.
+
+This action has the following parameters:
+
+- Rt-Component Target Param;
+- Point Type Param;
+- Expected Axis Result Param.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+#### **51.19.8.1 Get OVS Position action effect**
+
+The effect of this action is as follows:
+
+- 1) if the point type parameter is “absolute”, this action evaluates the OVS position as absolute values in the OGSU and returns generic integers;
+- 2) otherwise (“relative”), this action evaluates the OVS position as relative values relatively to the corresponding OS and returns generic ratios;
+- 3) if the expected axis result parameter is “x”, “y” or “z”, the corresponding length of the OVS position on that axis is returned;
+- 4) otherwise (“xyz”), all the lengths of the OVS position are returned as a list containing three elements.
+
+#### **51.19.8.2 Get OVS Position additional error conditions**
+
+- the target addresses multiple entities, e.g. use of an alias which addresses a list of targets, or use of the “\*” wildcard instead of a given rt-component number, or use of children or descendants tails, the action is ignored for that target;
+- if the target is not accessible, e.g. the reference cannot be solved, the action is ignored for that target;
+- if the transition duration is negative, it is set to zero.
+
+#### **51.19.9 Get PVS action**
+
+This action retrieves the PVS of the target.
+
+This action has the following parameters:
+
+- Rt-Component Target Param;
+- Point Type Param;
+- Expected Axis Result Param.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+#### **51.19.9.1 Get PVS action effect**
+
+The effect of this action is as follows:
+
+- 1) if the point type parameter is “absolute”, this action evaluates the PVS as absolute values in the RGSU of the target and returns generic integers;
+- 2) otherwise (“relative”), this action evaluates the PVS as relative values relatively to the OS of the parent and returns generic ratios;
+- 3) if the expected axis result parameter is “x”, “y” or “z”, the corresponding size of the PVS on that axis is returned;
+- 4) otherwise (“xyz”), all the sizes of the PVS are returned as a list containing three elements.
+
+#### **51.19.9.2 Get PVS additional error conditions**
+
+- the target addresses multiple entities, e.g. use of an alias which addresses a list of targets, or use of the “\*” wildcard instead of a given rt-component number, or use of children or descendants tails, the action is ignored for that target;
+- if the target is not accessible, e.g. the reference cannot be solved, the action is ignored for that target;
+- if the transition duration is negative, it is set to zero.
+
+#### **51.19.10 Get PAP action**
+
+This action retrieves the PAP of the target.
+
+This action has the following parameters:
+
+- Rt-Component Target Param;
+- Point Type Param;
+- Expected Axis Result Param.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+#### **51.19.10.1 Get PAP action effect**
+
+The effect of this action is as follows:
+
+- 1) if the point type parameter is “absolute”, this action evaluates the PAP as absolute values in the RGSU of the target within the PVS and returns generic integers;
+- 2) otherwise (“relative”), this action evaluates the PAP as relative values relatively to the corresponding PVS and returns generic ratios;
+- 3) if the expected axis result parameter is “x”, “y” or “z”, the corresponding point of the PAP on that axis is returned;
+- 4) otherwise (“xyz”), all the points of the PAP are returned as a list containing three elements.
+
+#### **51.19.10.2 Get PAP additional error conditions**
+
+- the target addresses multiple entities, e.g. use of an alias which addresses a list of targets, or use of the “\*” wildcard instead of a given rt-component number, or use of children or descendants tails, the action is ignored for that target;
+- if the target is not accessible, e.g. the reference cannot be solved, the action is ignored for that target;
+- if the transition duration is negative, it is set to zero.
+
+### 51.19.11 Get PVS Position action
+
+This action retrieves the PVS position of the target.
+
+This action has the following parameters:
+
+- Rt-Component Target Param;
+- Point Type Param;
+- Expected Axis Result Param.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+#### 51.19.11.1 Get PVS Position action effect
+
+The effect of this action is as follows:
+
+- 1) if the point type parameter is “absolute”, this action evaluates the PVS position as absolute values in the RGSU of the target and returns generic integers;
+- 2) otherwise (“relative”), this action evaluates the PVS position as relative values relatively to the OS of the parent and returns generic ratios;
+- 3) if the expected axis result parameter is “x”, “y” or “z”, the corresponding length of the PVS position on that axis is returned;
+- 4) otherwise (“xyz”), all the lengths of the PVS position are returned as a list containing three elements.
+
+#### 51.19.11.2 Get PVS Position additional error conditions
+
+- the target addresses multiple entities, e.g. use of an alias which addresses a list of targets, or use of the “\*” wildcard instead of a given rt-component number, or use of children or descendants tails, the action is ignored for that target;
+- if the target is not accessible, e.g. the reference cannot be solved, the action is ignored for that target;
+- if the transition duration is negative, it is set to zero.
+
+### 51.19.12 Get GSF action
+
+This action retrieves the GSF of the target.
+
+This action has the following parameters:
+
+- Rt-Component Target Param;
+- Expected Axis Result Param.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+#### 51.19.12.1 Get GSF action effect
+
+The effect of this action is as follows:
+
+- 1) if the expected axis result parameter is “x”, “y” or “z”, the corresponding GSF of the target on that axis is returned as a generic integer;
+- 2) otherwise (“xyz”), all the GSFs of the target are returned as a list containing three generic integers.
+
+#### 51.19.12.2 Get GSF additional error conditions
+
+- the target addresses multiple entities, e.g. use of an alias which addresses a list of targets, or use of the “\*” wildcard instead of a given rt-component number, or use of children or descendants tails, the action is ignored for that target;
+- if the target is not accessible, e.g. the reference cannot be solved, the action is ignored for that target;
+- if the transition duration is negative, it is set to zero.
+
+### 51.19.13 Get User Spatial Control action
+
+This action retrieves the user spatial control attribute value.
+
+This action has the following parameters:
+
+- Rt-Component Target Param;
+- Spatial Control Param.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+#### **51.19.13.1 Get User Spatial Control effect**
+
+The effect of this action is as follows:
+
+- Depending on the specified spatial control parameter (“moving”, “resizing”, “scaling” or “scrolling”), this action returns “allowed” or “not allowed”.
+
+#### **51.19.13.2 Get User Spatial Control additional error conditions**
+
+- the target addresses multiple entities, e.g. use of an alias which addresses a list of targets, or use of the “\*” wildcard instead of a given rt-component number, or use of children or descendants tails, the action is ignored for that target;
+- if the target is not accessible, e.g. the reference cannot be solved, the action is ignored for that target;
+- if the transition duration is negative, it is set to zero.
+
+## **52 Rt-Components Audible Behaviour**
+
+The behaviour describes the audible presentation of rt-components. This Recommendation defines an initial value of this behaviour and means to modify it and to retrieve its value by using actions.
+
+### **52.1 Behaviour attributes and statuses**
+
+This behaviour is expressed using the following attributes or statuses:
+
+- OV (see 52.2);
+- CV (see 52.3);
+- PCV (see 52.4);
+- GVF (see 52.5).
+
+### **52.2 OV**
+
+Each rt-content has an OV that is defined within the AVR. However, there is no OV for an rt-composite. The OV is always measured in the GVU, and shall be in this range (see “Original Presentation Space” for initialisation of each OV).
+
+Each OV for an rt-content is set only once and shall not be changed.
+
+### **52.3 CV**
+
+Each rt-content has a CV that is initialised as the OV. The CV may be changed by using the Set CV action; however, the CV shall be within the AVR.
+
+### **52.4 PCV**
+
+The CV is projected to its RPS. That is called the PCV. The PCV is calculated by the GVF belonging to its RPS (PRPS or CPS) as  $CV \times GVF$ .
+
+NOTE – Each rt-component (rt-content and rt-composite) has a GTF and a GSF. However, rt-contents do not have GVF. Rt-Composites and channels have GVF. Instead of having a GVF, an rt-content has a CV that may be changed.
+
+## 52.5 GVF
+
+The projection of the CV in the OPS to the PCV in the RPS is controlled by the GVF belonging to the RPS. The GVF defines the number of RGVU corresponding to one OGVU Original presentation space.
+
+## 52.6 Actions to change the behaviour
+
+This Recommendation defines means to modify this behaviour by the use of the following actions:
+
+- Set CV action (see 52.6.1),
+- Set GVF action (see 52.6.2).
+
+### 52.6.1 Set CV action
+
+This action sets the CV of the target as specified value.
+
+This action has the following parameters:
+
+- Set of Rt-Content Target Param.
+- CV Param: Specified as an absolute value, a relative value, an original point factor or a current point factor.
+- Transition Duration Param: Specified as an absolute value, a relative value, an original point factor or a current point factor.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+#### 52.6.1.1 Set CV action effect
+
+This effect of this action is as follows:
+
+- 1) If the CV is specified as an absolute value, this value is set to the CV of the target.
+- 2) If the CV is specified as a relative value, this value is interpreted as a relative value to the AVR (0, 255) and the audible volume is calculated by  $255 \times (\text{specified value})$ . The calculated value is set to the CV of the target.
+- 3) If the CV is specified as an original point factor, the value,  $OV \times (\text{specified value})$ , is calculated and set to the CV of the target.
+- 4) Otherwise (the CV is specified as a current point factor), the value,  $(\text{current CV}) \times (\text{specified value})$ , is calculated and set to the CV.
+- 5) In above case, if the calculated value is outside the AVR, the value is set to 0 (if negative) or 255 (if greater than 255).
+
+If a non-zero transition duration is specified, the CV is gradually changed to the specified value.
+
+#### 52.6.1.2 Set CV additional error conditions
+
+- if one of the targets is not an rt-content in R2, R3 or R3.TD, this action is ignored for that target;
+- if the CV parameter defined as an absolute parameter value is not in interval of the AVR, this action is ignored for the whole target set;
+- if the transition duration is negative, it is set to zero.
+
+### 52.6.2 Set GVF action
+
+This action specifies the GVF of an rt-composite or a channel.
+
+This action has the following parameters:
+
+- GVF Target.
+- GVF Param: GVF value to be assigned.
+- Transition Duration Param: GVF value to be assigned.
+
+This action may be targeted during the periods R2, R3, R3.TD and C2.
+
+#### **52.6.2.1 Set GVF action effect**
+
+The effect of this action is as follows:
+
+- 1) the GVF of the target is set to the specified value;
+- 2) if the target is an rt-composite, all the PCVs of descendants are recalculated by this value;
+- 3) otherwise (the target is a channel), all the PCVs of rt-components assigned to this channel are recalculated by this value.
+
+If a non-zero transition duration is specified, the PCVs of the targets are gradually changed.
+
+#### **52.6.2.2 Set GVF additional error conditions**
+
+- if one of the targets is not an rt-composite or a channel in R2, R3, R3.TD or C2, this action is ignored for that target;
+- if the transition duration is negative, it is set to zero.
+
+### **52.7 Actions to retrieve the behaviour**
+
+This Recommendation defines means to get this behaviour by the use of the following actions:
+
+- Get OV action (see 52.7.1);
+- Get CV action (see 52.7.2);
+- Get PCV action (see 52.7.3);
+- Get GVF action (see 52.7.4).
+
+#### **52.7.1 Get OV action**
+
+This action retrieves the OV of the target.
+
+This action has the following parameter:
+
+- Rt-Content Target Param.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+##### **52.7.1.1 Get OV action effect**
+
+The effect of this action is as follows:
+
+- Retrieve the OV of the target expressed in the OGVU.
+
+##### **52.7.1.2 Get OV additional error conditions**
+
+- the target addresses multiple entities, e.g. use of an alias which addresses a list of targets, or use of the “\*” wildcard instead of a given rt-component number, or use of children or descendants tails, the action is ignored for that target;
+- if one of the targets is not an rt-content in R2, R3 or R3.TD, this action is ignored for that target.
+
+#### **52.7.2 Get CV action**
+
+This action retrieves the CV of the target.
+
+This action has the following parameter:
+
+- Rt-Content Target Param.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+##### **52.7.2.1 Get CV action effect**
+
+The effect of this action is as follows:
+
+- Retrieve the CV of the target expressed in the OGVU.
+
+#### 52.7.2.2 Get CV additional error conditions
+
+- the target addresses multiple entities, e.g. use of an alias which addresses a list of targets, or use of the “\*” wildcard instead of a given rt-component number, or use of children or descendants tails, the action is ignored for that target;
+- if one of the targets is not an rt-content in R2, R3 or R3.TD, this action is ignored for that target.
+
+#### 52.7.3 Get PCV action
+
+This action retrieves the PCV of the target.
+
+This action has the following parameter:
+
+- Rt-Content Target Param.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+##### 52.7.3.1 Get PCV action effect
+
+The effect of this action is as follows:
+
+- Retrieve the PCV of the target expressed in the RGVU.
+
+##### 52.7.3.2 Get PCV additional error conditions
+
+- the target addresses multiple entities, e.g. use of an alias which addresses a list of targets, or use of the “\*” wildcard instead of a given rt-component number, or use of children or descendants tails, the action is ignored for that target;
+- if one of the targets is not an rt-content in R2, R3 or R3.TD, this action is ignored for that target.
+
+#### 52.7.4 Get GVF action
+
+This action retrieves the GVF of the target.
+
+This action has the following parameters:
+
+- Rt-Composite Target Param;
+- Channel Target Param.
+
+This action may be targeted during the periods R2, R3 or R3.TD and C2.
+
+##### 52.7.4.1 Get GVF action effect
+
+The effect of this action is as follows:
+
+- Retrieve the GVF of the target as a generic ratio.
+
+##### 52.7.4.2 Get GVF additional error conditions
+
+- the target addresses multiple entities, e.g. use of an alias which addresses a list of targets, or use of the “\*” wildcard instead of a given rt-component number, or use of children or descendants tails, the action is ignored for that target;
+- if one of the targets is not an rt-component or a channel in R2, R3, R3.TD or C2, this action is ignored for that target.
+
+### 53 Rt-Mux Stream Choice Behaviour
+
+This behaviour describes the choices of the stream within an rt-mux. Once streams are chosen, the rt-mux is responsible for these chosen streams and ensure their presentation.
+
+#### 53.1 Behaviour attributes and statuses
+
+This behaviour is expressed using the following attributes or statuses:
+
+- Stream Choice (see 53.2),
+- Stream Chosen State (see 53.3).
+
+## 53.2 Stream Choice
+
+An rt-mux is responsible for the complete multiplexed data presentation or some specified streams presentation individually chosen within the multiplexed data.
+
+The stream choice attribute holds the chosen stream IDs as a list.
+
+Initially, all streams are chosen for an rt-mux, i.e. the rt-mux is responsible for the presentation of the complete multiplexed data. Thus, this attribute holds every stream ID.
+
+Once several streams are chosen for an rt-mux, it is responsible for the presentation of these chosen streams when it becomes “running”. In this case, typically the demultiplexing process is pipelined with the presentation of them, and therefore no new data is generated from the demultiplexing.
+
+## 53.3 Stream Chosen State
+
+Each stream in an rt-mux has a stream chosen state. If it is chosen, the state is “chosen”. Otherwise, the state is “not chosen”.
+
+Each rt-mux also has a stream chosen state. If all the streams of it are chosen, the state is “chosen”. If some streams of it are chosen, the state is “partially chosen”. Otherwise (no streams are chosen), the state is “not chosen”.
+
+## 53.4 Stream Identification
+
+Choice between a stream identifier or “all streams”.
+
+## 53.5 Actions to change the behaviour
+
+This Recommendation defines means to modify this behaviour by the use of the following action:
+
+- Set Stream Choice action (see 53.5.1).
+
+### 53.5.1 Set Stream Choice action
+
+The action chooses the streams that are to be presented within a target rt-mux.
+
+This action has the following parameters:
+
+- Set of Rt-Mux Target Param.
+- Set of Stream Spec Param: GVF value to be assigned.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+#### 53.5.1.1 Set Stream Choice action effect
+
+The effect of this action is as follows:
+
+- 1) according to the specified update command, streams are added, removed or replaced with a new set;
+- 2) if a “remove” command is used and no streams are specified, all streams currently chosen are changed to “not chosen”.
+
+The result of this action is to change stream chosen states of some streams and the rt-mux. There may be a user effect if the target is running.
+
+#### 53.5.1.2 Set Stream Choice additional error conditions
+
+- If one of the targets is not an rt-mux in <validperiod>, this action is ignored for that target.
+
+## 53.6 Actions to retrieve the behaviour
+
+This Recommendation defines means to get this behaviour by the use of the following actions:
+
+- Get Stream Choice action (see 53.6.1),
+- Get Stream Chosen State action (see 53.6.2).
+
+### 53.6.1 Get Stream Choice action
+
+This action retrieves a list of chosen stream IDs of the target.
+
+This action has the following parameter:
+
+- Rt-Mux Target Param.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+#### 53.6.1.1 Get Stream Choice action effect
+
+The effect of this action is as follows:
+
+- A list of chosen stream IDs are retrieved as a generic list.
+
+#### 53.6.1.2 Get Stream Choice additional error conditions
+
+- the target addresses multiple entities, e.g. use of an alias which addresses a list of targets, or use of the “\*” wildcard instead of a given rt-component number, or use of children or descendants tails, the action is ignored for that target;
+- if one of the targets is not an rt-mux in R2, R3 or R3.TD, this action is ignored for that target;
+- if the target is not accessible, e.g. the reference cannot be solved, the action is ignored for that target.
+
+### 53.6.2 Get Stream Chosen State action
+
+This action retrieves the stream state of the target.
+
+This action has the following parameters:
+
+- Rt-Mux Target Param.
+- Stream Identification Param: GVF value to be assigned.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+#### 53.6.2.1 Get Stream Chosen State action effect
+
+The effect of this action is as follows:
+
+- 1) if a stream ID is specified as a value of the stream identifier parameter, the stream state of the stream is retrieved;
+- 2) otherwise (i.e. “all streams” is specified as a value of the stream identifier parameter), the stream state of the target rt-mux is retrieved.
+
+#### 53.6.2.2 Get Stream Chosen State additional error conditions
+
+- the target addresses multiple entities, e.g. use of an alias which addresses a list of targets, or use of the “\*” wildcard instead of a given rt-component number, or use of children or descendants tails, the action is ignored for that target;
+- if one of the targets is not an rt-mux in R2, R3 or R3.TD, this action is ignored for that target;
+- if the target is not accessible, e.g. the reference cannot be solved, the action is ignored for that target.
+
+## 54 Interaction Behaviour
+
+The behaviour describes the interaction between rt-components and the user. Through this behaviour, the MHEG engine and MHEG entities interactive to the user. All rt-components may be interactive. Initially, each rt-component is not interactive.
+
+Through the event behaviour, the MHEG engine and the MHEG entities are also interact to the user. However, this interaction behaviour is dedicated especially to user’s selection and modification that are frequently used.
+
+## 54.1 Behaviour attributes and statuses
+
+This behaviour is expressed using the following attributes or statuses:
+
+- Interaction Type (see 54.2),
+- Interaction Status (see 54.3),
+- Selection Status (see 54.4),
+- Modification Status (see 54.5),
+- Interaction Ability (see 54.6),
+- Selectability (see 54.7),
+- Modifiability (see 54.8),
+- Min Interact Required (see 54.9),
+- Max Interact Required (see 54.10),
+- Number of Interacted Sockets (see 54.11).
+
+## 54.2 Interaction Type
+
+There are two interaction types for rt-components. One is “selection” concerning the user selection, and the other one is “modification” concerning the user modification. The two selection types are independent of each other so that one rt-component may have one of the interaction types of both simultaneously.
+
+The MHEG engine should manage the selection and the modification of rt-components with the help of the user interface. By the value of following interaction attributes, the MHEG engine is able to know the user interactions to rt-components.
+
+The user may interact to rt-components only if they are running. If an rt-component is not running, the user cannot interact to it and any states concerning the interaction behaviour shall not be changed.
+
+The two types of interactions are controlled and retrieved by the same set of elementary actions and get actions specifying the interaction type as a parameter.
+
+## 54.3 Interaction Status
+
+Each rt-component may have the selection status indicating the user selection on it, and each rt-component may also have the modification status indicating the user modification to it.
+
+The interaction status of an rt-component is set only if it is “running”. The interaction status is set explicitly by a Set Interaction Status action or implicitly by the user interaction.
+
+How to interact to rt-components is up to the MHEG engine and the user interface.
+
+### NOTES
+
+1 – Rt-contents may be selected by a mouse positioning and click, and may be modified by a mouse positioning and keyboard input.
+
+2 – Not only the visible rt-contents but also some audible rt-contents and multiplexed contents may be selected or modified. How to do that depends on the MHEG engine implementation and the using application.
+
+The interaction status may be perceptible (visibly or audibly) to show the current status of an rt-component to the user. However, it is an MHEG engine feature and this Recommendation does not specify any methods for that.
+
+## 54.4 Selection Status
+
+The selection status is “selected” or “not selected”. It indicates the results of the user selection.
+
+Initially, each rt-component is “not selected”.
+
+## 54.5 Modification Status
+
+The modification status is “modified”, “not modified” or “modifying”. It indicates the results of the user modification.
+
+Initially, each rt-component is “not modified”.
+
+## 54.6 Interaction Ability
+
+The two interaction types are allowed individually to assign each rt-component. The allowance of the selection is called selectability, and the allowance of the modification is called modifiability.
+
+The selectability tells the MHEG engine whether this rt-component is an item for selection. And the modifiability tells the MHEG engine whether this rt-component is an item for modification. If an rt-component is allowed for selection and modification, the user may select or modify it.
+
+The interaction ability may be perceptible (visibly or audibly) to show the interaction possibility of an rt-component to the user. However, it is the MHEG engine feature and this Recommendation does not specify any methods for that.
+
+## 54.7 Selectability
+
+Each rt-component has the selectability that is “selectable” or “not selectable”. This attribute is indirectly specified by a value but a value of the maximum interaction required attribute for the selection.
+
+The selectability attribute is calculated as follows:
+
+- If the maximum interaction required attribute for the selection is 0, it is “not selectable”.
+
+Otherwise, it is “selectable”.
+
+If an rt-component is “selectable”, the user may interact to it and may select it. Otherwise, the user selection is inhibited.
+
+## 54.8 Modifiability
+
+Each rt-component has the modifiability that is “modifiable” or “not modifiable”. This attribute is not directly specified by a value but a value of the maximum interaction required attribute value for the modification.
+
+The modifiability attribute is calculated as follows:
+
+- If the maximum interaction required attribute for the modification is 0, it is “not modifiable”
+
+Otherwise, it is “modifiable”.
+
+If an rt-component is “modifiable”, the user may interact to it and may modify it. Otherwise, the user modification is inhibited.
+
+## 54.9 Min Interact Required
+
+The selection and modification status for an rt-content is directly determined by a user interaction because the user can directly select and modify the rt-content. However, the selection and modification status for an rt-composite is not directly determined by a user interaction. The selection and modification status for an rt-composite are dynamically determined as follows:
+
+- If a Set Interaction Status action is targeted to an rt-composite, the rt-composite is set to the specified status regardless of the min interact required attribute, the max interact required attribute and some possible “modifying” child rt-components.
+
+NOTE 1 – It is an author’s intention whether to keep consistency among those attribute values if an explicit Set Interaction Status action is used.
+
+If one of the rt-components in an rt-composite is “modifying”, the rt-composite is determined as “modifying”.
+
+If a number of selected or modified rt-components in this rt-composite is greater than or equal to the min interact required attribute value, and if it is less than or equal to the max interact required attribute value, and if the user interaction process is done, then the rt-composite is determined as “selected” or “modified”.
+
+NOTE 2 – The MHEG engine should provide some mechanism that checks the end of user interaction process. It is not an automatic process to determine the interaction status. The user interaction may continue until the number of selected or modified rt-components becomes the value of the max interact required attribute even if the number is greater than the min interact required attribute value.
+
+Otherwise, the rt-composite is “not selected” or “not modified”.
+
+Therefore, the min interact required and max interact required attributes are provided for the MHEG engine as a hint to determine the interaction status of rt-composite.
+
+The number of interacted rt-components in an rt-composite may be changed dynamically due to a Plug action. It is the MHEG engine responsibility to keep the consistency among the children statuses, the parent status, the min interact required and the max interact required attributes for the parent.
+
+NOTE 3 – For example, if a selected rt-component is plugged into an rt-composite that has the max interact required attribute 5 and the number of selected sockets 6, the MHEG engine starts the user interaction process and asks the user to deselect one among the selected 6 sockets in order to satisfy the max interact required condition.
+
+NOTE 4 – For example, if the min interact required attribute is 2 and one of the selected sockets is unplugged, the MHEG engine starts the user interaction process and asks the user to select at least one more socket.
+
+NOTE 5 – For example, if the min interact required attribute is 5 and there are 4 sockets plugged into an rt-composite, the MHEG engine continues the user interaction process until some other rt-components are plugged in and at least 5 sockets are selected.
+
+NOTE 6 – If an rt-composite is not running, some inconsistency among those attributes may exist. Because the user may interact only if the rt-composite is running, the MHEG engine may ask the user later again to interact for that rt-composite if another Run action is targeted. Suppose that an rt-composite with one minute duration and “stop” for the temporal termination attribute is running and its min interact required is set to 1. In this case, if the user does not interact to the sockets of the rt-composite while it is running, the number of interacted sockets are less than the min interact required. If it is set to “running” again, the user interaction process begins again. This may be considered as a timer mechanism of the user interaction.
+
+The min interact required attribute is valid only for rt-composites. The value for an rt-content is always ignored and has no meaning.
+
+If the value of the min interact required attribute of an rt-composite is greater than or equal to 1, it means at least one interacted child is needed to change the interaction status of the parent rt-composite.
+
+Initially, the attribute is set to 0.
+
+## **54.10 Max Interact Required**
+
+The max interact required attribute is used to determine the interaction ability of an rt-component.
+
+The attribute for an rt-composite also gives a hint to the MHEG engine to control the number of interacted children. If the value of the max interact required attribute is greater than or equal to 1, it means that one interacted child is the maximum number of interacted children allowed for the rt-composite.
+
+The value of the max interact required shall be greater than or equal to the value of the min interact required for each interaction type.
+
+The MHEG engine shall prevent the number of interacted rt-components greater than the specified value of the max interact required.
+
+Initially, the attribute is set to 0.
+
+## **54.11 Number of Interacted Sockets**
+
+The number of interacted children may be evaluated. The number of interacted sockets attribute stores the value, and it may be retrieved by a Get Number of Interacted Sockets action.
+
+Initially, no sockets are interacted. Therefore, the attribute is set to 0.
+
+## **54.12 Actions to change the behaviour**
+
+This Recommendation defines means to modify this behaviour by the use of the following actions:
+
+- Set Interaction Ability action (see 54.12.1),
+- Set Interaction Status action (see 54.12.2).
+
+### **54.12.1 Set Interaction Ability action**
+
+This action sets the interaction ability to the target.
+
+This action has the following parameters:
+
+- Set of Rt-Component Target Param.
+- Interaction Type Param: GVF value to be assigned.
+- Min Interact Required Param: GVF value to be assigned.
+- Max Interact Required Param: GVF value to be assigned.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+#### **54.12.1.1 Set Interaction Ability action effect**
+
+According to the specified interaction type, the selection or the modification of the target is set. The effect of this action is as follows:
+
+- 1) the min interact required attribute is set to the specified value;
+- 2) the max interact required attribute is set to the specified value.
+
+The min interact required attribute value has no meaning for rt-contents.
+
+#### **54.12.1.2 Set Interaction Ability additional error conditions**
+
+- if one of the targets is not an rt-component in R2, R3 or R3.TD, this action is ignored for that target;
+- if the min interact required parameter value is a negative value, it is set to the value 0;
+- if the max interact required parameter value is a negative value, it is set to the value 0;
+- if the min interact required is greater than the max interact required, this action is ignored for the whole target set;
+- if the min interact required parameter value is not in interval (0, number of child sockets of the target), this action is ignored for the whole target set;
+- if the max interact required parameter value is not in interval (0, number of child sockets of the target), this action is ignored for the whole target set;
+- if the current number of interacted sockets is greater than the specified max interact required, this action is ignored for that target.
+
+### **54.12.2 Set Interaction Status action**
+
+This action sets the interaction status of the target.
+
+This action has the following parameters:
+
+- Set of Rt-Component Target Param.
+- Interaction Type Param: GVF value to be assigned.
+- Interaction Status Param: GVF value to be assigned.
+
+This action may be targeted during the periods R3 and R3.TD.
+
+#### 54.12.2.1 Set Interaction Status action effect
+
+The effect of this action is to set the interaction status according to the specified interaction type as follows:
+
+- 1) if the specified interaction type is “selection”, the interaction status of the target is set to either “selected” or “not selected”;
+- 2) otherwise (the specified interaction type is “modification”), the interaction status of the target is set to either “modified”, “not modified” or “modifying”.
+
+This action sets the interaction status regardless of any other related attribute values. It is for the author to decide whether to keep consistency among attribute values or not.
+
+#### 54.12.2.2 Set Interaction Status additional error conditions
+
+- If one of the targets is not an rt-component in R3 or R3.TD, this action is ignored for that target.
+
+### 54.13 Actions to retrieve the behaviour
+
+This Recommendation defines means to get this behaviour by the use of the following actions:
+
+- Get Interaction Ability action (see 54.13.1),
+- Get Min Interact Required action (see 54.13.2),
+- Get Max Interact Required action (see 54.13.3),
+- Get Interaction Status action (see 54.13.4),
+- Get Number of Interacted Sockets action (see 54.13.5).
+
+#### 54.13.1 Get Interaction Ability action
+
+This action retrieves the interaction ability of the target.
+
+This action has the following parameters:
+
+- Rt-Component Target Param.
+- Interaction Type Param: GVF value to be assigned.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+#### 54.13.1.1 Get Interaction Ability action effect
+
+According to the specified interaction type, the effect of this action is as follows:
+
+- 1) if the interaction type is “selection”, this action returns “selectable” or “not selectable”;
+- 2) otherwise (the interaction type is “modification”), this action returns “modifiable” or “not modifiable”.
+
+#### 54.13.1.2 Get Interaction Ability additional error conditions
+
+- the target addresses multiple entities, e.g. use of an alias which addresses a list of targets, or use of the “\*” wildcard instead of a given rt-component number, or use of children or descendants tails, the action is ignored for that target;
+- if the target is not an rt-component, the action is ignored for that target;
+- if the target is not accessible, e.g. the reference cannot be solved, the action is ignored for that target;
+- if one of the targets is not rt-component in R2, R3, R3.TD, this action is ignored for that target.
+
+### **54.13.2 Get Min Interact Required action**
+
+This action retrieves the min interact required of the target.
+
+This action has the following parameters:
+
+- Rt-Component Target Param.
+- Interaction Type Param: GVF value to be assigned.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+#### **54.13.2.1 Get Min Interact Required action effect**
+
+According to the specified interaction type, the value of the min interact required attribute for the selection or the modification is retrieved.
+
+#### **54.13.2.2 Get Min Interact Required additional error conditions**
+
+- the target addresses multiple entities, e.g. use of an alias which addresses a list of targets, or use of the “\*” wildcard instead of a given rt-component number, or use of children or descendants tails, the action is ignored for that target;
+- if the target is not an rt-component, the action is ignored for that target;
+- if the target is not accessible, e.g. the reference cannot be solved, the action is ignored for that target;
+- if one of the targets is not rt-component in R2, R3 or R3.TD, this action is ignored for that target.
+
+### **54.13.3 Get Max Interact Required action**
+
+This action retrieves the max interact required of the target.
+
+This action has the following parameters:
+
+- Rt-Component Target Param.
+- Interaction Type Param: GVF value to be assigned.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+#### **54.13.3.1 Get Max Interact Required action effect**
+
+According to the specified interaction type, the value of the max interact required attribute for the selection or the modification is retrieved.
+
+#### **54.13.3.2 Get Max Interact Required additional error conditions**
+
+- the target addresses multiple entities, e.g. use of an alias which addresses a list of targets, or use of the “\*” wildcard instead of a given rt-component number, or use of children or descendants tails, the action is ignored for that target;
+- if the target is not an rt-component, the action is ignored for that target;
+- if the target is not accessible, e.g. the reference cannot be solved, the action is ignored for that target;
+- if one of the targets is not rt-component in R2, R3 or R3.TD, this action is ignored for that target.
+
+### **54.13.4 Get Interaction Status action**
+
+This action retrieves the interaction status of the target.
+
+This action has the following parameters:
+
+- Rt-Component Target Param.
+- Interaction Type Param: GVF value to be assigned.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+#### 54.13.4.1 Get Interaction Status action effect
+
+According to the specified interaction type, the effect of this action is as follows:
+
+- 1) if the interaction type is “selection”, the selection status of the target is returned;
+- 2) otherwise (the interaction type is “modification”), the modification status of the target is returned.
+
+#### 54.13.4.2 Get Interaction Status additional error conditions
+
+- the target addresses multiple entities, e.g. use of an alias which addresses a list of targets, or use of the “\*” wildcard instead of a given rt-component number, or use of children or descendants tails, the action is ignored for that target;
+- if the target is not an rt-component, the action is ignored for that target;
+- if the target is not accessible, e.g. the reference cannot be solved, the action is ignored for that target;
+- if one of the targets is not rt-component in R2, R3 or R3.TD, this action is ignored for that target.
+
+#### 54.13.5 Get Number of Interacted Sockets action
+
+This action retrieves the number of interacted sockets of the target.
+
+This action has the following parameters:
+
+- Rt-Composite Target Param.
+- Interaction Type Param: GVF value to be assigned.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+#### 54.13.5.1 Get Number of Interacted Sockets action effect
+
+According to the specified interaction type, the number of selected or modified sockets is retrieved.
+
+#### 54.13.5.2 Get Number of Interacted Sockets additional error conditions
+
+- the target addresses multiple entities, e.g. use of an alias which addresses a list of targets, or use of the “\*” wildcard instead of a given rt-component number, or use of children or descendants tails, the action is ignored for that target;
+- if the target is not an rt-component, the action is ignored for that target;
+- if the target is not accessible, e.g. the reference cannot be solved, the action is ignored for that target;
+- if one of the targets is not rt-composite in R2, R3 or R3.TD, this action is ignored for that target.
+
+## 55 Rt-Components Style Behaviour
+
+This behaviour describes the style of rt-component. Each rt-component may have a style. A style may change the user perception of rt-contents.
+
+A style is a way of presentation, and may be compared to a predefined behaviour or style of presentation. Applying a style to a target avoids the author describing this behaviour or presentation. The MHEG engine uses the information described in the style to directly map a style to a facility provided by the user interface if possible. If the user interface does not provide such a facility, the MHEG engine is able to interpret the style with the description of the predefined behaviour provided for each style.
+
+The following are some examples of the style behaviour:
+
+- an rt-non-mux containing a generic integer may be displayed as a graphical slider with the style of “slider”;
+- an rt-non-mux containing audio may be listened to through a speaker as audio, or may be displayed as wave in graphical way.
+
+## **55.1 Behaviour attributes and statuses**
+
+This behaviour is expressed using the following attribute or status:
+
+- Style (see 55.2).
+
+## **55.2 Style**
+
+A style is a catalogued entry, either registered or proprietary. This attribute gives a logical style to the rt-component. How the style is perceived by the user depends on the MHEG engine and the GUI.
+
+## **55.3 Actions to change the behaviour**
+
+This Recommendation defines means to modify this behaviour by the use of the following action:
+
+- Set Style action (see 55.3.1).
+
+### **55.3.1 Set Style action**
+
+This action assigns a style to the target.
+
+This action has the following parameters:
+
+- Set of Rt-Component Target Param.
+- Catalogued Style Param.
+- Additional Information Param: It may be used by a specific style to interchange some additional information to be associated with, for example, a value range for a slider style. The number of generic values required and the semantics of those generic values, depend on a style.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+#### **55.3.1.1 Set Style action effect**
+
+The effect of this action is as follows:
+
+- Depending on the specified style param and the additional information param, a style is assigned to the target.
+- The previous style applied to the target is removed.
+
+If a Run action is targeted to the target after applying this action, the target is presented with the current specified style. If the target is running at the time of applying this action, there may be a user effect associated with this action.
+
+NOTE – The MHEG engine may directly map the target on a style facility provided by its user interface. However, certain attributes and statuses may be used in link objects, e.g. the selection status of the target, the position and size of the target. They have to be updated by the MHEG engine according to the style and coherently with the current user interaction.
+
+#### **55.3.1.2 Set Style additional error conditions**
+
+- If one of the targets is not an rt-component in R2, R3 or R3.TD, this action is ignored for that target.
+
+## **55.4 Actions to change the behaviour**
+
+This Recommendation defines means to modify this behaviour by the use of the following actions:
+
+- Get Style action (see 55.4.1).
+
+### **55.4.1 Get Style action**
+
+This action retrieves the current style associated with the target.
+
+This action has the following parameter:
+
+- Rt-Component Target Param.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+### 55.4.1.1 Get Style action effect
+
+The effect of this action is as follows:
+
+- This action evaluates a list corresponding to the catalogued styles that are applied to the target.
+
+### 55.4.1.2 Get Style additional error conditions
+
+- If one of the targets is not an rt-component in R2, R3 or R3.TD, this action is ignored for that target.
+
+## 56 Rt-Contents Anchor Behaviour
+
+This behaviour describes the anchor function of an rt-content. An anchor is an rt-content created from a content object, which contains anchor information.
+
+An anchor is characterised as follows:
+
+- An anchor is distinguished from a normal rt-content by the optional data classification attribute of the content object. If this classification attribute is “Anchor”, then this content object has anchor information inside, and rt-contents created from this content object may be used as anchors.
+- An anchor may be used to create a hotspot on another rt-component. The content data contained in an anchor is used to attach the anchor to another rt-content, e.g. starting point and end point, rectangular area, polygon area. This content data is called anchor information. If an rt-content to which an anchor is attached is modified in its presentation (e.g. resize, move), the anchor should follow its modification and change its position or shape automatically. The semantics of this anchor information is not defined by this Recommendation. It depends on rt-contents to which anchors are attached, the MHEG engine or the application.
+- The hook in an anchor is used to indicate the semantics of anchor information. It provides an encoding format which is used to describe the rendering of the anchor, the attachment points in the rt-content which the anchor is attached to, and the semantic of the anchor. Since the encoding format is registered, the use of the hook is the way to have a generic implementation of anchor mechanism.
+- The anchor information is used by the GUI or some other system that supports the rendering of rt-contents, and appropriate rendering of an anchor is to be done by it.
+- As an anchor is an rt-content, its selection status tells the MHEG engine that the hotspot specified by this anchor is selected by a user action. A Run action or a Stop action may make an anchor active or inactive. A Set Interaction Ability action may also make an anchor active or inactive.
+- An anchor has preparation behaviour, rt-availability behaviour, running behaviour, Interaction behaviour and rt-contents anchor behaviour, but no other behaviours. If such behaviours that should not be applied to an anchor are applied, these behaviours are ignored by the anchor.
+
+Figure 57 shows an example of using anchors. In this figure, three anchors (rt-content 1, rt-content 2, rt-content 3) are attached to the hub document (rt-content A). Depending on the anchor information, each anchor specifies the shape and the position of the hotspot within the hub document. A rendering system displays anchors in an appropriate way. If the user selects one of the anchors, the link objects associated with these anchors are fired and lead the user to another presentation.
+
+### 56.1 Behaviour attributes and statuses
+
+None.
+
+### 56.2 Actions to change the behaviour
+
+This Recommendation defines means to modify this behaviour by the use of the following action:
+
+- Attach Anchor action (see 56.2.1).
+
+![Diagram illustrating anchors and links in a hub document. A large gray rectangle represents the 'Hub document (rt-content A)'. Inside it are three shapes: a rectangle (Anchor 1), an oval (Anchor 3), and a star (Anchor 2). Lines connect these shapes to labels outside the rectangle: 'Anchor 1 (rt-content 1)' for the rectangle, 'Anchor 2 (rt-content 2)' for the star, and 'Anchor 3 (rt-content 3)' for the oval. Below the hub document is a box containing three links: 'Link L1: If rt-content 1 is selected, Run rt-content B', 'Link L2: If rt-content 2 is selected, Run rt-content C', and 'Link L3: If rt-content 3 is selected, Run rt-content D'. The identifier 'T0825990-96/d055' is at the bottom right.](0317016f1967843fe2643d09bd7bee9d_img.jpg)
+
+Hub document (rt-content A)
+
+Anchor 1 (rt-content 1)
+
+Anchor 2 (rt-content 2)
+
+Anchor 3 (rt-content 3)
+
+Link L1: If rt-content 1 is selected, Run rt-content B  
+ Link L2: If rt-content 2 is selected, Run rt-content C  
+ Link L3: If rt-content 3 is selected, Run rt-content D
+
+T0825990-96/d055
+
+Diagram illustrating anchors and links in a hub document. A large gray rectangle represents the 'Hub document (rt-content A)'. Inside it are three shapes: a rectangle (Anchor 1), an oval (Anchor 3), and a star (Anchor 2). Lines connect these shapes to labels outside the rectangle: 'Anchor 1 (rt-content 1)' for the rectangle, 'Anchor 2 (rt-content 2)' for the star, and 'Anchor 3 (rt-content 3)' for the oval. Below the hub document is a box containing three links: 'Link L1: If rt-content 1 is selected, Run rt-content B', 'Link L2: If rt-content 2 is selected, Run rt-content C', and 'Link L3: If rt-content 3 is selected, Run rt-content D'. The identifier 'T0825990-96/d055' is at the bottom right.
+
+**Figure 57/T.171 – Example of anchors**
+
+### 56.2.1 Attach Anchor action
+
+This action attaches anchors to the target.
+
+This action has the following parameters:
+
+- Set of Rt-Content Target Param.
+- Set of Anchor Spec Param: It may be used by a specific style to interchange some additional information to be associated with. For example, a value range for a slider style. How many generic values are required the semantics of those generic values, depends on a style.
+
+This action may be targeted during the periods R2, R3 and R3.TD.
+
+#### 56.2.1.1 Attach Anchor action effect
+
+The effect of this action is as follows:
+
+- Depending on the specified update command, specified anchors are added, removed or replaced.
+
+#### 56.2.1.2 Attach Anchor additional error conditions
+
+- if one of the targets is not an rt-content in R2, R3 or R3.TD, this action is ignored for that target;
+- if one of the anchors is not an anchor (i.e. containing no catalogued classification attribute as “Anchor”), this action is ignored for that anchor.
+
+## SECTION 7 – CHANNELS BEHAVIOUR
+
+### 57 Channel Availability Behaviour
+
+This behaviour describes the availability of channels. Each channel has this behaviour.
+
+#### 57.1 Behaviour attributes and statuses
+
+This behaviour is expressed using the following attribute or status:
+
+- Channel Availability Status (see 57.2).
+
+#### 57.2 Channel Availability Status
+
+The availability of each channel to the MHEG engine may be evaluated. The channel availability status indicates whether a channel is available. This status has one of the two values, “available” or “not available”.
+
+The channel availability status should be evaluated to “not available” if the channel cannot be activated by the MHEG engine, i.e. the channel is in period C1 (see 29.3, “Channel availability”).
+
+NOTE 1 – “Cannot” means that the channel has not been formally created or has been deleted. It does not mean that equipment required to perform the processing is not operational.
+
+For example, the channel has not yet been created by the MHEG engine, i.e. a New action has not yet been targeted.
+
+The channel availability status should be evaluated to “available” if the channel is activated by the MHEG engine, i.e. the channel has been created by the MHEG engine and is in the period C2.
+
+NOTE 2 – The MHEG engine may offer to the using application a more detailed diagnostic and information message. For example, to explain that a channel cannot be created, or to indicate error conditions. These messages are not defined by this Recommendation, but may be defined by another standard.
+
+Initially, each channel expect for the default channel is “not available” to the MHEG engine.
+
+#### 57.3 Actions to change the behaviour
+
+This Recommendation defines means to modify this behaviour by the use of the following actions:
+
+- New Channel action (see 57.3.1);
+- Delete Channel action (see 57.3.2).
+
+##### 57.3.1 New Channel action
+
+This action creates channels. This is used to obtain a logical perception space through which the assigned rt-components are perceived.
+
+The channel creation process is outside the scope of this Recommendation and is provided by the MHEG engine.
+
+This action has the following parameter:
+
+- Set of Channel Target Param.
+
+This action may be targeted during the period C1.
+
+##### 57.3.1.1 New Channel action effect
+
+The MHEG effect of this action is as follows:
+
+- 1) Construct the target channel (see 9.3).
+- 2) Assign a channel identifier (target of this action) to the constructed channel.
+- 3) Initialise the channel perceptability behaviour as “off”.
+- 4) Set the channel availability status of the target to “available”. The created channel enters in period C2.
+
+#### 57.3.1.2 New Channel additional error conditions
+
+- if one of the targets is not a channel in C1, this action is ignored for that target;
+- if an existing channel identifier is used in one of the targets, this action is ignored for that target;
+- if one of the targets is the default channel, this action is ignored for that target.
+
+#### 57.3.2 Delete Channel action
+
+This action removes channels from the MHEG engine. This may be used to release resources in the MHEG engine.
+
+This action has the following parameter:
+
+- Set of Channel Target Param.
+
+This action may be targeted during the period C2.
+
+##### 57.3.2.1 Delete Channel action effect
+
+The effect of this action is as follows:
+
+- 1) Destroy the channel perceptability behaviour.  
+Object designer should be aware that if the channel is “on”, the channel and all associated rt-components disappear. How to handle the disappearance is not defined by this Recommendation. It is left to the MHEG engine.
+- 2) Implicit Stop actions are targeted to all rt-components assigned to the targets.
+- 3) All rt-components assigned to the target are deassigned, and a Set Channel Assignment action targeted to the default channel is implicitly targeted to those rt-components.
+- 4) NOTE 1 – The behaviours of those rt-components remain identical after the deassignment.
+- 5) NOTE 2 – Destroy the target and its CPS.  
+Set the channel availability status of the target to “not available”. The channel enters in period C1.
+
+##### 57.3.2.2 Delete Channel additional error conditions
+
+- if one of the targets is not a channel in C2, this action is ignored for that target;
+- if one of the targets is the default channel, this action is ignored for that target.
+
+#### 57.4 Actions to retrieve the behaviour
+
+This Recommendation defines means to get this behaviour by the use of the following action:
+
+- Get Channel Availability Status action (see 57.4.1).
+
+##### 57.4.1 Get Channel Availability Status action
+
+This action retrieves the channel availability status of the target.
+
+This action has the following parameter:
+
+- Channel Target Param.
+
+This action may be targeted during the periods C1 and C2.
+
+##### 57.4.1.1 Get Channel action effect
+
+The effect of this action is as follows:
+
+- 1) if the target is in period C1, this action evaluates “not available”;
+- 2) otherwise (the target is in period C2), this action evaluates “available”.
+
+#### 57.4.1.2 Get Channel Availability Status additional error conditions
+
+- the target addresses multiple entities, e.g. use of an alias which addresses a list of targets, or use of the “\*” wildcard instead of a given rt-component number, or use of children or descendants tails, the action is ignored for that target;
+- if the target is not a channel, this action is ignored for that target;
+- if the target is not accessible, e.g. the reference cannot be solved, the action is ignored for that target.
+
+## 58 Channel Perceptability Behaviour
+
+This behaviour describes the perceptability of channels. All channels have this behaviour.
+
+### 58.1 Behaviour attributes and statuses
+
+This behaviour is expressed using the following attribute or status:
+
+- Channel Perceptability (see 58.2).
+
+### 58.2 Channel Perceptability
+
+Each channel may be turned on and off. If a channel is turned on, all the rt-components assigned to this channel are perceived by the user. If a channel is turned off, all the rt-components assigned to this channel are no more perceived by the user.
+
+NOTE – Rt-Components may be assigned and positioned to a non-perceptible channel. If the channel is turned on, all the assigned rt-components appear as specified previously.
+
+The channel perceptability has one of the two values, “on” or “off”.
+
+Initially, the default channel is turned on. So the channel perceptability state is “on”. However, all other channels are turned off. So their channel perceptability is “off”.
+
+### 58.3 Actions to change the behaviour
+
+This Recommendation defines means to modify this behaviour by the use of the following action:
+
+- Set Channel Perceptability action (see 58.3.1).
+
+#### 58.3.1 Set Channel Perceptability action
+
+This action changes the channel perceptability of a target.
+
+This action has the following parameters:
+
+- Set of Channel Target Param;
+- Channel Perceptability Param.
+
+This action may be targeted during the period C2.
+
+##### 58.3.1.1 Set Channel Perceptability action effect
+
+The effect of this action is as follows:
+
+- Set the channel perceptability of the target as specified
+  - 1) if the target is set to “off”, the target is turned off;
+  - 2) otherwise (the target is set to “on”), the target is turned on.
+
+There is no effect if the specified value is the same as the current value.
+
+##### 58.3.1.2 Set Channel Perceptability additional error conditions
+
+- If one of the targets is not a channel in C2, this action is ignored for that target.
+
+## **58.4 Actions to retrieve the behaviour**
+
+This Recommendation defines means to get this behaviour by the use of the following action:
+
+- Get Channel Perceptability action (see 58.4.1).
+
+### **58.4.1 Get Channel Perceptability action**
+
+This action retrieves the channel perceptability of the target.
+
+This action has the following parameter:
+
+- Channel Target Param.
+
+This action may be targeted during the period C2.
+
+#### **58.4.1.1 Get Channel Perceptability action effect**
+
+This action evaluates the current value of the channel perceptability attribute, and returns “on” or “off” depending on the state.
+
+#### **58.4.1.2 Get Channel Perceptability additional error conditions**
+
+- the target addresses multiple entities, e.g. use of an alias which addresses a list of targets, or use of the “\*” wildcard instead of a given rt-component number, or use of children or descendants tails, the action is ignored for that target;
+- if one of the targets is not a channel in C2, this action is ignored for that target;
+- if the target is not accessible, e.g. the reference cannot be solved, the action is ignored for that target.
+
+## **59 Channel Presentation Space Behaviour**
+
+This behaviour describes the channel presentation space. At the creation of channels, each presentation space of a channel is initialised to the default values. These values may be changed after creation.
+
+### **59.1 Behaviour attributes and statuses**
+
+None.
+
+### **59.2 Actions to change the behaviour**
+
+This Recommendation defines means to modify this behaviour by the use of the following action:
+
+- Set CPS action (see 59.2.1).
+
+#### **59.2.1 Set CPS action**
+
+This action specifies the CPS of the target channel.
+
+This action has the following parameters:
+
+- Set of Channel Target Param;
+- CPS Initialisation Param.
+
+This action may be targeted during the period C2.
+
+#### **59.2.1.1 Set CPS action effect**
+
+The effect of this action is as follows:
+
+- 1) The temporal axis of the target CPS is set to the specified CPS duration. If it is omitted, the temporal axis is set to infinite.
+- 2) The spatial axis of the target CPS is set to the specified CPS size. If it is omitted on a certain axis, this spatial axis is set to 0.
+
+There may be a user effect. If the spatial axes of the CPS are shrunk, some rt-components projected to this CPS may become invisible.
+
+#### 59.2.1.2 Set CPS additional error conditions
+
+- If one of the targets is not a channel in C2, this action is ignored for that target.
+
+## SECTION 8 – CHANNELS AND RT-COMPONENTS BEHAVIOUR
+
+### 60 Channels and Rt-Components Events Behaviour
+
+This behaviour describes the events that may occur on channels and rt-components.
+
+The behaviour allows the MHEG engine to get events that may arise not only from the MHEG engine but also from some systems or system components outside of it.
+
+#### 60.1 Behaviour attributes and statuses
+
+This behaviour is expressed using the following attributes or statuses:
+
+- Event (see 60.2);
+- Event Data (see 60.3).
+
+#### 60.2 Event
+
+An event is identified by a catalogued entry that is a list. An event identifier 0 is reserved to represent the status that no event has occurred.
+
+The event attribute holds the event identifier that has occurred most recently to a channel or an rt-component. Initially, each event attribute is set to 0. This behaviour may be changed by the occurrence of an event.
+
+#### 60.3 Event Data
+
+An event data attribute stores the information associated with the event most recently received by a channel or rt-component if the event requests to store additional information. The value stored in an event data attribute is a generic value. Its valid structure and allowed values are catalogued associated with an event.
+
+Initially, the value of an event data attribute is set to a specific value depending on the encoding of the MHEG object. In this Recommendation, it is a NULL in ASN.1.
+
+#### 60.4 Actions to change the behaviour
+
+This Recommendation defines means to modify this behaviour by the use of the following action:
+
+- Set Event action (see 60.4.1).
+
+##### 60.4.1 Set Event action
+
+This action sends an event to the target by the intention of the author. This action may be implicitly targeted if the MHEG engine or some systems generate an event and if this event is catalogued.
+
+This action has the following parameters:
+
+- Set of Rt-Component Channel Tg Param.
+- Event Param.
+- Event Data Param: Specifies associated data with an event.
+
+This action may be targeted during the periods R2, R3, R3.TD and C2.
+
+#### **60.4.1.1 Set Event action effect**
+
+The effect of this action is as follows:
+
+- 1) set the event attribute of the target as specified;
+- 2) if the event data is associated with the event, the event data attribute is filled with it;
+- 3) otherwise (the event data is omitted), the event data attribute is set to NULL.
+
+It is an author's responsibility to keep the consistency between the event attribute and the event data attribute if this action is explicitly used.
+
+It is the MHEG engine or the using application responsibility to keep this consistency if this action is implicitly used.
+
+#### **60.4.1.2 Set Event additional error conditions**
+
+- If one of the targets is not an rt-component or a channel in R2, R3, R3.TD or C2, this action is ignored for that target.
+
+### **60.5 Actions to retrieve the behaviour**
+
+This Recommendation defines means to get this behaviour by the use of the following actions:
+
+- Get Event action (see 60.5.1).
+- Get Event Data action (see 60.5.2).
+
+#### **60.5.1 Get Event action**
+
+This action retrieves the event that happened most recently to the target.
+
+This action has the following parameter:
+
+- Rt-Component Channel Tg Param: Specifies associated data with an event.
+
+This action may be targeted during the periods R2, R3, R3.TD and C2.
+
+##### **60.5.1.1 Get Event action effect**
+
+The effect of this action is as follows:
+
+- The event attribute is elevated and stored value is returned.
+
+##### **60.5.1.2 Get Event additional error conditions**
+
+- If one of the targets is not an rt-component or a channel in R2, R3, R3.TD or C2, this action is ignored for that target.
+
+#### **60.5.2 Get Event Data action**
+
+This action retrieves the event data of the target that is associated with the most recently happened event.
+
+This action has the following parameter:
+
+- Rt-Component Channel Tg Param: Specifies associated data with an event.
+
+This action may be targeted during the periods R2, R3, R3.TD and C2.
+
+##### **60.5.2.1 Get Event Data action effect**
+
+The effect of this action is as follows:
+
+- The event data attribute is evaluated and stored value is returned.
+
+##### **60.5.2.2 Get Event Data additional error conditions**
+
+- If one of the targets is not an rt-component or a channel in R2, R3, R3.TD or C2, this action is ignored for that target.
+
+## SECTION 9 – DETAILED REPRESENTATION OF MHEG OBJECTS
+
+### 61 MH-object class representation attributes
+
+Table 4/T.171 – Overview of MH-object class representation attributes
+
+|                                                                                                                                                                                                                                 |
+|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| <b>MH-object Class</b> ::= Class Identification, Mheg ID?, Description?                                                                                                                                                         |
+| <b>Class Identification</b> ::= #joint-iso-itu-t, #mheg, #version, Class ID                                                                                                                                                     |
+| <b>Class ID</b> ::=<br>#action-class-ID   #link-class-ID   #script-class-ID   #content-class-ID   #multiplexed-content-class-ID   #composite-class-ID  <br>#container-class-ID   #descriptor-class-ID   Extensibility Provision |
+| <b>Description</b> ::=<br>Name?, Owner?, Version?, Date?, Keywords?, Copyright?, Copyright ID?, Copyright Number?, Licence?, Cache Priority?,<br>Comments?, Extensibility Provision                                             |
+| <b>Name</b> ::= String                                                                                                                                                                                                          |
+| <b>Owner</b> ::= String                                                                                                                                                                                                         |
+| <b>Version</b> ::= String                                                                                                                                                                                                       |
+| <b>Date</b> ::= <i>\$UTCTime</i>                                                                                                                                                                                                |
+| <b>Keywords</b> ::= String*                                                                                                                                                                                                     |
+| <b>Copyright</b> ::= String                                                                                                                                                                                                     |
+| <b>Copyright ID</b> ::= <i>\$OCTET STRING</i>                                                                                                                                                                                   |
+| <b>Copyright Number</b> ::= <i>\$OCTET STRING</i>                                                                                                                                                                               |
+| <b>Licence</b> ::= String                                                                                                                                                                                                       |
+| <b>Cache Priority</b> ::= Integer                                                                                                                                                                                               |
+| <b>Comments</b> ::= String                                                                                                                                                                                                      |
+
+#### 61.1 MH-object Class
+
+- The MH-object class provides the structure for the identification and interchange of all MHEG objects. It provides also the generic addressing mechanism. MH-object class is an abstract class providing a consistent approach to the precise identification and interchange of all MHEG objects.
+
+Inherits from: NONE
+
+Addresses: NONE
+
+Inherited by: Action, Link, Model, Container and Descriptor classes
+
+Addressed by: NONE
+
+- Sequence of (Class Identification, Mheg ID?, Description?).
+
+#### 61.2 Class Identification
+
+- Identification of the class by:
+  - MHEG Standard: joint-iso-itu (2) mheg (19)
+  - MHEG Standard version: (1)
+  - Class identifier corresponding to the interchanged object
+- Sequence of (joint-iso-itu, mheg, version, Class ID).
+
+### **61.3 Class ID**
+
+- Identification of the MHEG object class of the interchanged object.
+- Choice between (action-class-ID, link-class-ID, script-class-ID, content-class-ID, multiplexed-content-class-ID, composite-class-ID, container-class-ID, descriptor-class-ID, Extensibility Provision).
+
+### **61.4 Description**
+
+- More precise description of an MHEG interchanged object.
+- Sequence of (Name?, Owner?, Version?, Date?, Keywords?, Copyright?, Copyright ID?, Copyright Number?, Licence?, Cache Priority?, Comments?, Extensibility Provision).
+
+### **61.5 Name**
+
+- Name of the MHEG object.
+- String.
+
+### **61.6 Owner**
+
+- Identification of the owner of the MHEG object.
+- String.
+
+### **61.7 Version**
+
+- Identification of the version of the MHEG object.
+- String.
+
+### **61.8 Date**
+
+- Latest modification date of the MHEG object. In the base notation, ASN.1, ISO format Universal Time (UTC) is used.
+- UTCTime.
+
+### **61.9 Keywords**
+
+- List of keywords qualifying the MHEG object.
+- List of (String).
+
+### **61.10 Copyright**
+
+- Content of the copyright attached to the MHEG object.
+- String.
+
+### **61.11 Copyright ID**
+
+- Work type code identifier.
+- OCTET STRING.
+
+### **61.12 Copyright Number**
+
+- Unique identification code of each work.
+- OCTET STRING.
+
+### **61.13 Licence**
+
+- Information concerning the licence attached to the MHEG object.
+- String.
+
+## 61.14 Cache Priority
+
+- It provides a facility for memory management and is used by the MHEG engine for optimisation of Prepare and Destroy actions. The value should be within the interval (0, 255).
+- Integer.
+
+## 61.15 Comments
+
+- Free format comments attached to the MHEG object.
+- String.
+
+## 62 Action class representation attributes
+
+Table 5/T.171 – Overview of Action class representation attributes
+
+|                                                                                         |
+|-----------------------------------------------------------------------------------------|
+| <b>Action Class</b> ::=                                                                 |
+| MH-object Class, Synchro Indicator Param, Synchronised Action+, Extensibility Provision |
+| <b>Synchro Indicator Param</b> ::= Synchro Indicator   Synchro Indicator Macro          |
+| <b>Synchro Indicator Macro</b> ::= Macro Def ID, Synchro Indicator?                     |
+| <b>Synchro Indicator</b> ::= <i>#serial</i>   <i>#parallel</i>                          |
+| <b>Synchronised Action</b> ::= Elementary Action   Action Object                        |
+| <b>Action Object</b> ::= Action Object Reference   Action Class                         |
+
+### 62.1 Action Class
+
+- The action class provides a consistent structure for the interchange of sets of actions. It also provides a consistent structure for the interchange of basic action object, nested action object. Action objects, instances of action class, are used to interchange an organised set of elementary actions.
+
+Inherits from: MH-object Class
+
+Addresses: Action Class
+
+Inherited by: NONE
+
+Addressed by: Link Class, Composite Class, Container Class
+
+- Sequence of (MH-object Class, Synchro Indicator Param, Synchronised Action+, Extensibility Provision).
+
+### 62.2 Synchro Indicator Param
+
+- Parameter of Synchro Indicator.
+- Choice between (Synchro Indicator, Synchro Indicator Macro).
+
+### 62.3 Synchro Indicator Macro
+
+- Allows the specification of a macro parameter instead of a specified Synchro Indicator value.
+- Sequence of (Macro Def ID, Synchro Indicator?).
+
+## 62.4 Synchro Indicator
+
+- This parameter specifies if the following group of synchronised actions are to be performed in parallel or serially.
+- Choice between (serial, parallel).
+
+## 62.5 Synchronised Action
+
+- Defines a recursive structure to express combination of actions. Each synchronised action within this group is either a single elementary action or another nested action object.
+- Choice between (Elementary Action, Action Object).
+
+## 62.6 Action Object
+
+- The action object can be referenced or included in the object.
+- Choice between (Action Object Reference, Action Class).
+
+# 63 Link class representation attributes
+
+Table 6/T.171 – Overview of Link class representation attributes
+
+|                                                                                                                                                |
+|------------------------------------------------------------------------------------------------------------------------------------------------|
+| <b>Link Class</b> ::= MH-object Class, Link Condition, Link Effect, Extensibility Provision                                                    |
+| <b>Link Condition</b> ::= Trigger Condition   Logical Combination                                                                              |
+| <b>Trigger Condition</b> ::= Source Value, Previous Condition?, Current Condition                                                              |
+| <b>Constraint Condition</b> ::= Source Value, Current Condition                                                                                |
+| <b>Source Value</b> ::= Evaluated Value                                                                                                        |
+| <b>Comparison Operation</b> ::= Comparison Operator, Comparison Value                                                                          |
+| <b>Comparison Value</b> ::= Generic Value   Comparison Value Constant   <i>#unspecified</i>                                                    |
+| <b>Previous Condition</b> ::= Comparison Operation                                                                                             |
+| <b>Current Condition</b> ::= Comparison Operation                                                                                              |
+| <b>Comparison Operator</b> ::= <i>#equal</i>   <i>#not-equal</i>   <i>#greater</i>   <i>#greater-equal</i>   <i>#less</i>   <i>#less-equal</i> |
+| <b>Logical Combination</b> ::= Logical Operator, Condition+                                                                                    |
+| <b>Logical Operator</b> ::= <i>#and</i>   <i>#or</i>   <i>#xor</i>   <i>#not</i>                                                               |
+| <b>Condition</b> ::= Trigger Condition   Constraint Condition   Logical Combination                                                            |
+| <b>Link Effect</b> ::= Macro Parameter Resolution*, Action Object                                                                              |
+| <b>Macro Parameter Resolution</b> ::= Macro Def ID, Usage Value                                                                                |
+| <b>Usage Value</b> ::= Generic Value                                                                                                           |
+
+## 63.1 Link Class
+
+- The Link class provides a consistent structure for the interchange of conditional actions targeted to MHEG objects, run-time objects or channels. MHEG link objects, instances of Link class, may be interchanged. A link object is directional and connects one or more sources with one or more targets. The actions defined within the link are processed on the indicated targets only if the conditions are satisfied.
+
+Inherits from: MH-object class
+
+Addresses: Action class
+
+Inherited by: NONE
+
+Addressed by: Composite class, Container Class
+
+- Sequence of (MH-object Class, Link Condition, Link Effect, Extensibility Provision).
+
+### **63.2 Link Condition**
+
+- Defines the condition of the link. The link effect is to be performed each time the link condition becomes evaluated to true.
+- Choice between (Trigger Condition, Logical Combination).
+
+### **63.3 Trigger Condition**
+
+- Defines a trigger condition which is described as a change of an attribute or status value.
+- Sequence of (Source Value, Previous Condition?, Current Condition).
+
+### **63.4 Constraint Condition**
+
+- Defines a constraint condition which tests a current state of a value.
+- Sequence of (Source Value, Current Condition).
+
+### **63.5 Source Value**
+
+- Identifies the status or attribute of an object which is to be compared in a previous or a current condition. The evaluated value is the result of a get action targeted on a single object. Otherwise the source value is “undefined”.
+- Evaluated Value.
+
+### **63.6 Comparison Operation**
+
+- Describes a comparison operation to be performed on source value in order to fulfil a condition.
+- Sequence of (Comparison Operator, Comparison Value).
+
+### **63.7 Comparison Value**
+
+- Specification of the value to be compared to the source value using the comparison operator. It is for the object designer to ensure that the type of the current comparison value is compatible with the source value.
+- Choice between (Generic Value, Comparison Value Constant, unspecified).
+
+### **63.8 Previous Condition**
+
+- Defines the Previous Condition on the source value.  
+If the Previous Condition is omitted, it means that the Previous Condition is evaluated as: NOT Current Condition.
+- Comparison Operation.
+
+### **63.9 Current Condition**
+
+- Defines the Current Condition on the source value.
+- Comparison Operation.
+
+### **63.10 Comparison Operator**
+
+- Specifies the operation to be made between the source value and the comparison value.
+- Choice between (equal, not-equal, greater, greater-equal, less, less-equal).
+
+### 63.11 Logical Combination
+
+- Defines a tree structure to express combination of conditions. The Logical operator constitutes a node of the logical tree of conditions. The set of conditions constitutes the leaves of this node. When the logical operator is NOT, only one condition is allowed. Any other operator needs at least two conditions.
+- Sequence of (Logical Operator, Condition+).
+
+### 63.12 Logical Operator
+
+- Defines the logical operation to be applied between the conditions of the node.
+- Choice between (and, or, xor, not).
+
+### 63.13 Condition
+
+- Defines the conditions on which the logical operation is to be applied.
+- Choice between (Trigger Condition, Constraint Condition, Logical Combination).
+
+### 63.14 Link Effect
+
+- Defines the macro resolution providing a usage value to each macro parameter and the action object to be performed when the result of the link is fired.
+- Sequence of (Macro Parameter Resolution\*, Action Object).
+
+### 63.15 Macro Parameter Resolution
+
+- Associates a usage value to a macro Def ID.
+- Sequence of (Macro Def ID, Usage Value).
+
+### 63.16 Usage Value
+
+- Assigns a usage value to a macro Def ID. It is for the object designer to ensure that the usage value is compatible with the parameter which has been specified using a macro Def ID.
+- Generic Value.
+
+## 64 Model class representation attributes
+
+Table 7/T.171 – Overview of Model class representation attributes
+
+|                                        |
+|----------------------------------------|
+| <b>Model Class</b> ::= MH-object Class |
+|----------------------------------------|
+
+### 64.1 Model Class
+
+- Model Class is an abstract class. The script class and the component class inherit this class. Model class is an abstract class.  
+Inherits from: MH-object class  
+Addresses: NONE  
+Inherited by: Script Class, Component Class  
+Addressed by: NONE
+- MH-object Class.
+
+## 65 Script class representation attributes
+
+Table 8/T.171 – Overview of Script class representation attributes
+
+|                                                                                                                                                                                                                                                                                                                                                                                                                                              |
+|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| <p><b>Script Class</b> ::= Model Class, Script Classification?, Script Hook, Script Data, Extensibility Provision</p> <p><b>Script Classification</b> ::= Catalogued Script Classification</p> <p><b>Script Data</b> ::= Script Inclusion   Data Reference</p> <p><b>Script Inclusion</b> ::= <i>§BIT STRING</i>   <i>§OCTET STRING</i>   InterchangedScript</p> <p><b>InterchangedScript</b> ::= <i>#Imported from ITU-T Rec. T.173</i></p> |
+|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+
+### 65.1 Script Class
+
+- The Script class provides a consistent structure for the interchange of complex actions on MHEG entities. MHEG script objects, instances of Script class, may be interchanged. A script object contains an indication of the scripting language used and the encoded script itself. It is assumed that the scripting language used in a script object is able to reference MHEG entities and access their attributes.  
+Inherits from: Model class  
+Addresses: NONE  
+Inherited by: NONE  
+Addressed by: Container class
+- Sequence of (Model Class, Script Classification?, Script Hook, Script Data, Extensibility Provision).
+
+### 65.2 Script Classification
+
+- One of the catalogued script classification, it may be a registered one or a proprietary one.
+- Catalogued Script Classification.
+
+### 65.3 Script Data
+
+- Encoded script according to the scripting language identified by the script hook. This script data may be included in the script object itself or referenced by using the mechanism of external identifier or alias. A null script data may be also used.
+- Choice between (Script Inclusion, Data Reference).
+
+### 65.4 Script Inclusion
+
+- The script data is included in the interchanged script object.
+- Choice between (BIT STRING, OCTET STRING, InterchangedScript).
+
+### 65.5 InterchangedScript
+
+- The Interchanged Script syntax is provided by Recommendation T.173.
+- Imported from Recommendation T.173.
+
+## 66 Component class representation attributes
+
+Table 9/T.171 – Overview of Component class representation attributes
+
+|                                                                    |
+|--------------------------------------------------------------------|
+| <p><b>Component Class</b> ::= Model Class, OPS Initialisation?</p> |
+|--------------------------------------------------------------------|
+
+## 66.1 Component Class
+
+- Component Class is an abstract class. The content class and the composite class inherit this class. Component class is an abstract class.  
+Inherits from: Model class  
+Addresses: NONE  
+Inherited by: Content Class, Composite Class  
+Addressed by: NONE
+- Sequence of (Model Class, OPS Initialisation?).
+
+## 67 Content class representation attributes
+
+Table 10/T.171 – Overview of Content class representation attributes
+
+|                                                                                                        |
+|--------------------------------------------------------------------------------------------------------|
+| <b>Content Class</b> ::=                                                                               |
+| Component Class, Cat Content Classification?, Content Hook, OV?, Content Data, Extensibility Provision |
+| <b>Content Data</b> ::= Data Inclusion   Data Reference                                                |
+| <b>Data Inclusion</b> ::= <i>\$BIT STRING</i>   <i>\$OCTET STRING</i>   Generic Value                  |
+
+### 67.1 Content Class
+
+- The content class provides a consistent structure for the interchange of encoded data. MHEG content objects, instances of Content class, may be interchanged. A content object provides the identification of the type, and the interchange of data.  
+Inherits from: Component Class  
+Addresses: NONE  
+Inherited by: Multiplexed Content Class  
+Addressed by: Composite Class, Container Class
+- Sequence of (Component Class, Cat Content Classification?, Content Hook, OV?, Content Data, Extensibility Provision).
+
+### 67.2 Content Data
+
+- Encoded data provided by other Recommendations and standards or by proprietary format. This data is included in the content object itself or referenced by using the mechanism of alias or external identifier offered. A Null-Data can also be specified.  
+The content data is not limited to encoding schemes provided by International Standards. The reference to content data facility in this Recommendation provides a mechanism for reference to content data conforming to any standard including private standards.
+- Choice between (Data Inclusion, Data Reference).
+
+### 67.3 Data Inclusion
+
+- The data is included in the interchanged content object.
+- Choice between (BIT STRING, OCTET STRING, Generic Value).
+
+## 68 Multiplexed content class representation attributes
+
+Table 11/T.171 – Overview of Multiplexed content class representation attributes
+
+|                                                                                                  |
+|--------------------------------------------------------------------------------------------------|
+| <b>Multiplexed Content Class</b> ::= Content Class, Multiplexed Stream+, Extensibility Provision |
+| <b>Multiplexed Stream</b> ::= Stream ID, Cat Content Classification?, Content Hook?              |
+
+## 68.1 Multiplexed Content Class
+
+- The multiplexed content class provides a consistent structure for the exchange of multiplexed media data. The multiplexed content class is a model class which is a subclass of the content class. It contains or refers to the coded representation of a multiplexed media data together with a description of each multiplexed stream. A Multiplexed Content Class represents the association between a Content Class and an ordered list of streams describing the streams contained in the multiplexed data.
+
+Inherits from: Content class
+
+Addresses: NONE
+
+Inherited by: NONE
+
+Addressed by: Composite, Container classes
+
+- Sequence of (Content Class, Multiplexed Stream+, Extensibility Provision).
+
+## 68.2 Multiplexed Stream
+
+- Defines a stream of the multiplexed data and specific information.
+- Sequence of (Stream ID, Cat Content Classification?, Content Hook?).
+
+## 69 Composite class representation attributes
+
+Table 12/T.171 – Overview of Composite class representation attributes
+
+### Composite Class ::=
+
+Component Class, Availability Start-up?, Availability Close-down?, Rt-Availability Start-up?, Rt-Availability Close-down?, Action Object\*, Link Object\*, Nb Of Elements, Composition Element\*, Extensibility Provision
+
+### Availability Start-up ::=
+
+Link Effect | *#automatic-start-up-1* | *#automatic-start-up-2* | *#automatic start-up-3* | *#automatic-start-up-4* | *#automatic-start-up-5*
+
+### Availability Close-down ::=
+
+Link Effect | *#automatic-close-down-1* | *#automatic-close-down-2* | *#automatic-close-down-3*
+
+### Rt-Availability Start-up ::= Link Effect | *#automatic-rt-start-up*
+
+### Rt-Availability Close-down ::= Link Effect
+
+### Link Object ::= Link Class | Link Object Reference
+
+### Nb Of Elements ::= Integer
+
+### Composition Element ::= Index, Associated Model
+
+### Element Index ::= Index
+
+### Associated Model ::=
+
+Component Object Reference | Content Class | Multiplexed Content Class | Composite Class | Label
+
+### Label ::= String
+
+## 69.1 Composite Class
+
+- The composite class provides a consistent approach to the synchronisation in time and space, linking, encapsulation of a set of objects and interchange of these objects. MHEG composite objects, instances of composite class, may be interchanged. A composite object addresses actions, links to describe the initial and dynamic behaviour of the component objects and the rt-objects created from these composite objects.
+
+Inherits from: Component class
+
+Addresses: Link, Action, Content, Multiplexed Content and Composite classes
+
+Inherited by: NONE
+
+Addressed by: Composite class
+
+- Sequence of (Component Class, Availability Start-up?, Availability Close-down?, Rt-Availability Start-up?, Rt-Availability Close-down?, Action Object\*, Link Object\*, Nb of Elements, Composition Element\*, Extensibility Provision).
+
+## **69.2 Availability Start-up**
+
+- The composite availability start-up may be used for additional preparation effect of the composite. It is either a personalised link effect provided by the author or one of the default link effects provided by this Recommendation.
+- Choice between (Link Effect, automatic-start-up-1, automatic-start-up-2, automatic start-up-3, automatic-start-up-4, automatic-start-up-5).
+
+## **69.3 Availability Close-down**
+
+- The composite close-down start-up may be used for additional destruction effect of the composite. It is either a personalised link effect provided by the author or one of the default link effects provided by this Recommendation.
+- Choice between (Link Effect, automatic-close-down-1, automatic-close-down-2, automatic-close-down-3).
+
+## **69.4 Rt-Availability Start-up**
+
+- The rt-availability start-up may be used for additional creation effect of the rt-composite. It is either a personalised link effect provided by the author or the default link effect provided by this Recommendation.
+- Choice between (Link Effect, automatic-rt-start-up).
+
+## **69.5 Rt-Availability Close-down**
+
+- The rt-availability close-down may be used for additional destruction effect of the rt-composite. It is always a personalised link effect provided by the author.
+- Link Effect.
+
+## **69.6 Link Object**
+
+- Link object used to describe the behaviour of each element and the interrelationships between parent and siblings. The link object can be referenced or included in the composite object.
+- Choice between (Link Class, Link Object Reference).
+
+## **69.7 Nb of Elements**
+
+- Indicates the number of elements within the composition.
+- Integer.
+
+## **69.8 Composition Element**
+
+- Defines the internal structure of the composite. This structure provides a support for created rt-composites.
+
+If no elements are included, the MHEG engine deduces that the composite has “Nb of Elements” empty elements.
+
+If the last element has an index lower than “Nb of Elements”, the MHEG engine deduces that empty elements are repeated from the last element until the “Nb of Element” element.
+
+Each element has an index and refers a model component object or a label. The component object may be interchanged included in this composite object or externally. The label is always included.
+
+Empty elements are not encoded but are implicitly generated by the MHEG engine.
+
+- Sequence of (Index, Associated Model).
+
+## 69.9 Element Index
+
+- Index of the associated model unique within a composite.
+- Index.
+
+## 69.10 Associated Model
+
+- The element addresses either a component object or a label.
+- Choice between (Component Object Reference, Content Class, Multiplexed Content Class, Composite Class, Label).
+
+## 69.11 Label
+
+- A label is a string, it can be provided as an element of a composite.
+- String.
+
+## 70 Container class representation attributes
+
+**Table 13/T.171 – Overview of Container class representation attributes**
+
+|                                                                                                                                                                                                                                                                                                                                                                                      |
+|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| <b>Container Class ::=</b><br>MH-object Class, Container Start-up?, Container Close-down?, Container Element+, Extensibility Provision                                                                                                                                                                                                                                               |
+| <b>Container Start-up ::=</b><br>Link Effect   <i>#automatic-container-start-up-1</i>   <i>#automatic-container-start-up-2</i>   <i>#automatic-container-start-up-3</i>   <i>#automatic-container-start-up-4</i>   <i>#automatic-container-start-up-5</i>   <i>#automatic-container-start-up-6</i>   <i>#automatic-container-start-up-7</i>   <i>#automatic-container-start-up-8</i> |
+| <b>Container Close-down ::=</b> Link Effect   <i>#automatic-container-close-down</i>                                                                                                                                                                                                                                                                                                 |
+| <b>Container Element ::=</b><br>MH-Reference   Action Class   Link Class   Script Class   Content Class   Multiplexed Content Class   Composite Class   Container Class   Descriptor Class                                                                                                                                                                                           |
+
+### 70.1 Container Class
+
+- The container class provides a consistent structure for the handling of multimedia and hypermedia information.  
+  
+ This regroupment is intended to facilitate the interchange in order to obtain in a unit set of interchange. Defines the elements of the container to be exchanged. The indexes of the components do not require to be encoded because the elements are numbered from 1 to n by the MHEG engine.  
+  
+ Inherits from: MH Object class  
+  
+ Addresses: Link, Action, Script, Content, Multiplexed Content, Composite, Descriptor and Container classes  
+  
+ Inherited by: NONE  
+  
+ Addressed by: NONE
+- Sequence of (MH-object Class, Container Start-up?, Container Close-down?, Container Element+, Extensibility Provision).
+
+### 70.2 Container Start-up
+
+- The container start-up may be used for additional preparation effect of the container. It is either a personalised link effect provided by the author or one of the default link effects provided by this Recommendation.
+- Choice between (Link Effect, *automatic-container-start-up-1*, *automatic-container-start-up-2*, *automatic-container-start-up-3*, *automatic-container-start-up-4*, *automatic-container-start-up-5*, *automatic-container-start-up-6*, *automatic-container-start-up-7*, *automatic-container-start-up-8*).
+
+### 70.3 Container Close-down
+
+- The container availability close-down may be used for additional destruction effect of the container. It is either a personalised link effect provided by the author or the default link effect provided by this Recommendation.
+- Choice between (Link Effect, automatic-container-close-down).
+
+### 70.4 Container Element
+
+- An element can be included or referenced.
+- Choice between (MH-Reference, Action Class, Link Class, Script Class, Content Class, Multiplexed Content Class, Composite Class, Container Class, Descriptor Class).
+
+## 71 Descriptor class representation attributes
+
+Table 14/T.171 – Overview of Descriptor class representation attributes
+
+**Descriptor Class ::=**
+
+MH-object Class, Related Object\*, Other Descriptor\*, Readme?, System Readable Material?, Channel Information\*, Catalogued Style Information\*, Cat Ext elementary action Info\*, Cat Ext Attribute Info\*, Extensibility Provision
+
+**Related Object ::=** MH-Reference, Object Information?
+
+**Object Information ::=** Object Size?, Class ID, Class Specific Information?, Offset?
+
+**Object Size ::=** Integer
+
+**Class Specific Information ::=**
+
+Script Class Information | Content Class Information | Mux Content Class Info
+
+**Script Class Information: ::=** Script Classification?, Script Hook?
+
+**Content Class Information ::=** Cat Content Classification?, Content Hook?, Alternative Object\*
+
+**Mux Content Class Info ::=** Content Class Information, Number Of Streams?, Stream Information\*
+
+**Number Of Streams ::=** Integer
+
+**Stream Information ::=** Stream ID, Content Class Information
+
+**Alternative Object ::=**
+
+Content Object Ref, Content Hook?, Alternative Descriptor Object?, Alternative Readme?
+
+**Alternative Descriptor Object ::=** Descriptor Object Reference
+
+**Alternative Readme ::=** String
+
+**Offset::=Integer**
+
+**Other Descriptor ::=** Descriptor Object Reference
+
+**Readme::=String**
+
+**System Readable Material ::=** *\$BIT STRING* | *\$OCTET STRING*
+
+**Channel Information ::=**
+
+Channel ID, X min?, X max?, Y min?, Y max?, Z min?, Z max?, X Resolution?, Y Resolution?, Z Resolution?, T Resolution?, F min?, F max?, Audio Dynamic?, Channel Media Type\*, Event Mapping\*
+
+**X min: ::=** Integer
+
+**X max ::=** Integer
+
+**Y min ::=** Integer
+
+**Y max ::=** Integer
+
+**Table 14/T.171 – Overview of Descriptor class representation attributes (concluded)**
+
+|                                                                  |
+|------------------------------------------------------------------|
+| <b>Z min</b> ::= Integer                                         |
+| <b>Z max</b> ::= Integer                                         |
+| <b>X Resolution</b> ::= Integer                                  |
+| <b>Y Resolution</b> ::= Integer                                  |
+| <b>Z Resolution</b> ::= Integer                                  |
+| <b>T Resolution</b> ::= Integer                                  |
+| <b>F min</b> ::= Integer                                         |
+| <b>F max</b> ::= Integer                                         |
+| <b>Audio Dynamic</b> ::= Integer                                 |
+| <b>Channel Media Type</b> ::= Catalogued Media Type              |
+| <b>Event Mapping</b> ::= Event, Catalogued Event?                |
+| <b>Catalogued Style Information</b> ::= Catalogued Style         |
+| <b>Cat Ext elementary action Info</b> ::= Catalogued Extended EA |
+| <b>Cat Ext Attribute Info</b> ::= Cat Ext Attribute              |
+
+## 71.1 Descriptor Class
+
+- The descriptor class defines a description of objects that are to be interchanged. The aim is to facilitate the negotiation, installation, operation and management of applications that interchange MHEG objects. MHEG descriptor objects, instances of descriptor class, may be interchanged. A descriptor object describes the support provided for the description of other objects that are interchanged.
+- Sequence of (MH-object Class, Related Object\*, Other Descriptor\*, Readme?, System Readable Material?, Channel Information\*, Catalogued Style Information\*, Cat Ext elementary action Info\*, Cat Ext Attribute Info\*, Extensibility Provision).
+
+## 71.2 Related Object
+
+- Specifies the scope of the descriptor, i.e. the list of MHEG objects concerned by this descriptor.
+- Sequence of (MH-Reference, Object Information?).
+
+## 71.3 Object Information
+
+- Defines more precisely the related object.
+- Sequence of (Object Size?, Class ID, Class Specific Information?, Offset?).
+
+## 71.4 Object Size
+
+- Size of the related encoded object in octets.
+- Integer.
+
+## 71.5 Class Specific Information
+
+- Object specific information.
+- Choice between (Script Class Information, Content Class Information, Mux Content Class Info).
+
+## 71.6 Script Class Information
+
+- Carries information specific to the script class.
+- Sequence of (Script Classification?, Script Hook?).
+
+### **71.7 Content Class Information**
+
+- Carries information specific to the content class.
+- Sequence of (Cat Content Classification?, Content Hook?, Alternative Object\*).
+
+### **71.8 Mux Content Class Info**
+
+- Carries information specific to the multiplexed content class.
+- Sequence of (Content Class Information, Number of Streams?, Stream Information\*).
+
+### **71.9 Number of Streams**
+
+- Reflects the number of sub-streams.
+- Integer.
+
+### **71.10 Stream Information**
+
+- Further information belonging to stream.
+- Sequence of (Stream ID, Content Class Information).
+
+### **71.11 Alternative Object**
+
+- Provides information about possible alternative objects that an engine can use instead of the related object.
+- Sequence of (Content Object Ref, Content Hook?, Alternative Descriptor Object?, Alternative Readme?).
+
+### **71.12 Alternative Descriptor Object**
+
+- References the alternative descriptor where the alternative objects are described.
+- Descriptor Object Reference.
+
+### **71.13 Alternative Readme**
+
+- Identifies the nature of the alternative object.
+- String.
+
+### **71.14 Offset**
+
+- Provides a relative position in octets of an encoded object which is included in another encoded object.
+- Integer.
+
+### **71.15 Other Descriptor**
+
+- Specifies a reference to another descriptor object.
+- Descriptor Object Reference.
+
+### **71.16 Readme**
+
+- Provides readable text for human users.
+- String.
+
+### **71.17 System Readable Material**
+
+- Provides information for using applications.
+- Choice between (BIT STRING, OCTET STRING).
+
+### **71.18 Channel Information**
+
+- Contains information to handle a channel.
+- Sequence of (Channel ID, X min?, X max?, Y min?, Y max?, Z min?, Z max?, X Resolution?, Y Resolution?, Z Resolution?, T Resolution?, F min?, F max?, Audio Dynamic?, Channel Media Type\*, Event Mapping\*).
+
+### **71.19 X min**
+
+- Defines the minimum X-axis value for the device on which this channel is to be mapped.
+- Integer.
+
+### **71.20 X max**
+
+- Defines the maximum X-axis value for the device on which this channel is to be mapped.
+- Integer.
+
+### **71.21 Y min**
+
+- Defines the minimum Y-axis value for the device on which this channel is to be mapped.
+- Integer.
+
+### **71.22 Y max**
+
+- Defines the maximum Y-axis value for the device on which this channel is to be mapped.
+- Integer.
+
+### **71.23 Z min**
+
+- Defines the minimum Z-axis value for the device on which this channel is to be mapped.
+- Integer.
+
+### **71.24 Z max**
+
+- Defines the maximum Z-axis value for the device on which this channel is to be mapped.
+- Integer.
+
+### **71.25 X Resolution**
+
+- Number of addressable spatial physical units on X axis.
+- Integer.
+
+### **71.26 Y Resolution**
+
+- Number of addressable spatial physical units on Y axis.
+- Integer.
+
+### **71.27 Z Resolution**
+
+- Number of addressable spatial physical units on Z axis.
+- Integer.
+
+### **71.28 T Resolution**
+
+- Number of addressable spatial physical units in one second on T axis.
+- Integer.
+
+### 71.29 **F min**
+
+- Defines the minimum presentable frequency for the device on which this channel is to be mapped.
+- Integer.
+
+### 71.30 **F max**
+
+- Defines the maximum presentable frequency for the device on which this channel is to be mapped.
+- Integer.
+
+### 71.31 **Audio Dynamic**
+
+- Defines the audio dynamic for the device on which the channel is to be mapped. The units are dB.
+- Integer.
+
+### 71.32 **Channel Media Type**
+
+- Specifies the type of media of the channel, it is one of the catalogued value which can be either registered or proprietary.
+- Catalogued Media Type.
+
+### 71.33 **Event Mapping**
+
+- Specifies the expected events and their mapping on a catalogued event.
+- Sequence of (Event, Catalogued Event?).
+
+### 71.34 **Catalogued Style Information**
+
+- Specifies which style is used by the related objects.
+- Catalogued Style.
+
+### 71.35 **Cat Ext elementary action Info**
+
+- Specifies which catalogued elementary action is used by the related objects.
+- Catalogued Extended EA.
+
+### 71.36 **Cat Ext Attribute Info**
+
+- Specifies which extended attribute is used by the related objects.
+- Cat Ext Attribute.
+
+## 72 **Behaviours**
+
+### 72.1 **Postpone behaviour**
+
+**Table 15/T.171 – Overview of Postpone behaviour**
+
+**Delay ::=** Temporal Unit Ref Param, Duration Param
+
+**Temporal Unit Ref Param ::=** Temporal Unit Ref | Temporal Unit Ref Macro
+
+**Temporal Unit Ref Macro ::=** Macro Def ID, Temporal Unit Ref?
+
+**Temporal Unit Ref ::=** Rt-Component Reference | default-GF
+
+**Duration Param ::=** Generic Integer Param
+
+### 72.1.1 Delay
+
+- This action enables to delay the process of further actions.
+- Sequence of (Temporal Unit Ref Param, Duration Param).
+
+### 72.1.2 Temporal Unit Ref Param
+
+- Parameter of Temporal Unit Ref.
+- Choice between (Temporal Unit Ref, Temporal Unit Ref Macro).
+
+### 72.1.3 Temporal Unit Ref Macro
+
+- Allows the specification of a macro parameter instead of a specified Temporal Unit Ref value.
+- Sequence of (Macro Def ID, Temporal Unit Ref?).
+
+### 72.1.4 Temporal Unit Ref
+
+- Defines how to retrieve the GTF in order to interpret the delay.
+- Choice between (Rt-Component Reference, default-GF).
+
+### 72.1.5 Duration Param
+
+- The duration is expressed in GTU.
+- Generic Integer Param.
+
+## 72.2 Returnability behaviour
+
+**Table 16/T.171 – Overview of Returnability behaviour**
+
+**Return ::=**
+
+Return Target Param+, Return Indicator Param, Returned Generic Value Param\*, Content Object Ref Param\*
+
+**Return Indicator Param ::=** Generic Numeric Param
+
+**Returned Generic Value Param ::=** Generic Value Param
+
+**Content Object Ref Param ::=** Content Object Ref | Content Object Ref Macro
+
+**Content Object Ref Macro ::=** Macro Def ID, Content Object Ref?
+
+### 72.2.1 Return
+
+- This action enable to return information to a using application or external entities outside the MHEG engine.
+- Sequence of (Return Target Param+, Return Indicator Param, Returned Generic Value Param\*, Content Object Ref Param\*).
+
+### 72.2.2 Return Indicator Param
+
+- Identification for returning information.
+- Generic Numeric Param.
+
+### 72.2.3 Returned Generic Value Param
+
+- A list of generic values to be returned.
+- Generic Value Param.
+
+### 72.2.4 Content Object Ref Param
+
+- A list of content objects to be returned.
+- Choice between (Content Object Ref, Content Object Ref Macro).
+
+### 72.2.5 Content Object Ref Macro
+
+- Allows the specification of a macro parameter instead of a specified Content Object Ref value.
+- Sequence of (Macro Def ID, Content Object Ref?).
+
+## 72.3 Alias behaviour
+
+Table 17/T.171 – Overview of Alias behaviour
+
+**Set Alias** ::= Target Param+, Alias Spec Param+
+
+**Alias Spec Param** ::= Alias Spec | Alias Spec Macro
+
+**Alias Spec Macro** ::= Macro Def ID, Alias Spec?
+
+**Alias Spec** ::= Alias+, Update Command
+
+### 72.3.1 Set Alias
+
+- This action enables the assignment of aliases to any generic references.
+- Sequence of (Target Param+, Alias Spec Param+).
+
+### 72.3.2 Alias Spec Param
+
+- Parameter of Alias Spec.
+- Choice between (Alias Spec, Alias Spec Macro).
+
+### 72.3.3 Alias Spec Macro
+
+- Allows the specification of a macro parameter instead of a specified Alias Spec value.
+- Sequence of (Macro Def ID, Alias Spec?).
+
+### 72.3.4 Alias Spec
+
+- Aliases and an Update Command to be applied.
+- Sequence of (Alias+, Update Command).
+
+## 72.4 Extensibility behaviour
+
+Table 18/T.171 – Overview of Extensibility behaviour
+
+**Catalogued Elementary Action** ::=
+
+Target Param+, Catalogued Extended EA Param, Elementary Action Param\*
+
+**Catalogued Extended EA Param** ::= Catalogued Extended EA | Catalogued Extended EA Macro
+
+**Catalogued Extended EA Macro** ::= Macro Def ID, Catalogued Extended EA?
+
+**Elementary Action Param** ::= Generic Value Param
+
+**Set Catalogued Attribute** ::=
+
+Target Param+, Cat Ext Attribute Param, Ext Attribute Value Param, Transition Duration Param?
+
+**Ext Attribute Value Param** ::= Generic Value Param
+
+#### 72.4.1 Catalogued Elementary Action
+
+- This action enables to use an extended elementary action which is registered or proprietary.
+- Sequence of (Target Param+, Catalogued Extended EA Param, Elementary Action Param\*).
+
+#### 72.4.2 Catalogued Extended EA Param
+
+- Parameter of Catalogued Extended EA.
+- Choice between (Catalogued Extended EA, Catalogued Extended EA Macro).
+
+#### 72.4.3 Catalogued Extended EA Macro
+
+- Allows the specification of a macro parameter instead of a specified Catalogued Extended EA value.
+- Sequence of (Macro Def ID, Catalogued Extended EA?).
+
+#### 72.4.4 Elementary Action Param
+
+- Used to interchange the specific parameters of the catalogued extended elementary action.
+- Generic Value Param.
+
+#### 72.4.5 Set Catalogued Attribute
+
+- This action enables to set a value of a catalogued attribute for the target.
+- Sequence of (Target Param+, Cat Ext Attribute Param, Ext Attribute Value Param, Transition Duration Param?).
+
+#### 72.4.6 Ext Attribute Value Param
+
+- A generic value to be assigned to a Cat Ext Attribute.
+- Generic Value Param.
+
+### 72.5 Mheg objects availability behaviour
+
+**Table 19/T.171 – Overview of Mheg objects availability behaviour**
+
+|                                                                                       |
+|---------------------------------------------------------------------------------------|
+| <p><b>Prepare</b> ::= MH-Target Param+</p> <p><b>Destroy</b> ::= MH-Target Param+</p> |
+|---------------------------------------------------------------------------------------|
+
+#### 72.5.1 Prepare
+
+- This action makes the MHEG object available to the MHEG engine.
+- List of (MH-Target Param).
+
+#### 72.5.2 Destroy
+
+- Removes an MHEG object from the MHEG engine in order to release resources.
+- List of (MH-Target Param).
+
+### 72.6 Link object activation behaviour
+
+**Table 20/T.171 – Overview of Link object activation behaviour**
+
+|                                                                                               |
+|-----------------------------------------------------------------------------------------------|
+| <p><b>Activate</b> ::= Link Target Param+</p> <p><b>Deactivate</b> ::= Link Target Param+</p> |
+|-----------------------------------------------------------------------------------------------|
+
+### 72.6.1 Activate
+
+- Make the link object active.
+- List of (Link Target Param).
+
+### 72.6.2 Deactivate
+
+- Makes the link object inactive.
+- List of (Link Target Param).
+
+## 72.7 Link object abort behaviour
+
+**Table 21/T.171 – Overview of Link object abort behaviour**
+
+|                                          |
+|------------------------------------------|
+| <b>Link Abort</b> ::= Link Target Param+ |
+|------------------------------------------|
+
+### 72.7.1 Link Abort
+
+- Aborts processing of links specified in the target set.
+- List of (Link Target Param).
+
+## 72.8 Content class generic value storage behaviour
+
+**Table 22/T.171 – Overview of Content class generic value storage behaviour**
+
+|                                                                                              |
+|----------------------------------------------------------------------------------------------|
+| <b>Set Data</b> ::= Content Target Param+, Substitution Indicator Param, Data Element Param* |
+|----------------------------------------------------------------------------------------------|
+
+|                                                                                               |
+|-----------------------------------------------------------------------------------------------|
+| <b>Substitution Indicator Param</b> ::= Substitution Indicator   Substitution Indicator Macro |
+|-----------------------------------------------------------------------------------------------|
+
+|                                                                               |
+|-------------------------------------------------------------------------------|
+| <b>Substitution Indicator Macro</b> ::= Macro Def ID, Substitution Indicator? |
+|-------------------------------------------------------------------------------|
+
+|                                                                                  |
+|----------------------------------------------------------------------------------|
+| <b>Substitution Indicator</b> ::= <i>#substitution</i>   <i>#no-substitution</i> |
+|----------------------------------------------------------------------------------|
+
+|                                                                 |
+|-----------------------------------------------------------------|
+| <b>Data Element Param</b> ::= Data Element   Data Element Macro |
+|-----------------------------------------------------------------|
+
+|                                                           |
+|-----------------------------------------------------------|
+| <b>Data Element Macro</b> ::= Macro Def ID, Data Element? |
+|-----------------------------------------------------------|
+
+|                                                                                |
+|--------------------------------------------------------------------------------|
+| <b>Data Element</b> ::= Process Indicator, Generic List Elt ID?, Generic Value |
+|--------------------------------------------------------------------------------|
+
+|                                                                   |
+|-------------------------------------------------------------------|
+| <b>Process Indicator</b> ::= <i>#process</i>   <i>#no-process</i> |
+|-------------------------------------------------------------------|
+
+|                                                                                        |
+|----------------------------------------------------------------------------------------|
+| <b>Add</b> ::= Content Target Param+, Generic List Elt ID Param?, Generic Value Param? |
+|----------------------------------------------------------------------------------------|
+
+|                                                                                              |
+|----------------------------------------------------------------------------------------------|
+| <b>Substract</b> ::= Content Target Param+, Generic List Elt ID Param?, Generic Value Param? |
+|----------------------------------------------------------------------------------------------|
+
+### 72.8.1 Set Data
+
+- This action enables to store or to modify the generic value in a content object.
+- Sequence of (Content Target Param+, Substitution Indicator Param, Data Element Param\*).
+
+### 72.8.2 Substitution Indicator Param
+
+- Parameter of Substitution Indicator.
+- Choice between (Substitution Indicator, Substitution Indicator Macro).
+
+### 72.8.3 Substitution Indicator Macro
+
+- Allows the specification of a macro parameter instead of a specified Substitution Indicator value.
+- Sequence of (Macro Def ID, Substitution Indicator?).
+
+### 72.8.4 Substitution Indicator
+
+- Allowed values for the substitution indicator.
+- Choice between (substitution, no-substitution).
+
+### 72.8.5 Data Element Param
+
+- Parameter of Data Element.
+- Choice between (Data Element, Data Element Macro).
+
+### 72.8.6 Data Element Macro
+
+- Allows the specification of a macro parameter instead of a specified Data Element value.
+- Sequence of (Macro Def ID, Data Element?).
+
+### 72.8.7 Data Element
+
+- Indicates a data to be stored.
+- Sequence of (Process Indicator, Generic List Elt ID?, Generic Value).
+
+### 72.8.8 Process Indicator
+
+- Indicates a data to be stored after evaluated or not.
+- Choice between (process, no-process).
+
+### 72.8.9 Add
+
+- Adds a generic numeric, generic integer or generic ratio to a content data.
+- Sequence of (Content Target Param+, Generic List Elt ID Param?, Generic Value Param?).
+
+### 72.8.10 Subtract
+
+- Offer to subtract generic numeric, generic integer or generic ratio from a content data.
+- Sequence of (Content Target Param+, Generic List Elt ID Param?, Generic Value Param?).
+
+## 72.9 Content class copy behaviour
+
+**Table 23/T.171 – Overview of Content class copy behaviour**
+
+**Copy** ::= Content Target Param, Destination Param+
+
+**Destination Param** ::= Content Target Param
+
+### 72.9.1 Copy
+
+- This action specifies a target content object as a source of the copy operation and a set of content objects as destinations of the copy operation.
+- Sequence of (Content Target Param, Destination Param+).
+
+### 72.9.2 Destination Param
+
+- Content objects to which the target data are to be copied.
+- Content Target Param.
+
+## 72.10 Rt-objects availability behaviour
+
+Table 24/T.171 – Overview of Rt-objects availability behaviour
+
+|                                    |
+|------------------------------------|
+| <b>New</b> ::= Rt-Target Param+    |
+| <b>Delete</b> ::= Rt-Target Param+ |
+
+### 72.10.1 New
+
+- Creates rt-objects from model objects for the MHEG engine.
+- List of (Rt-Target Param).
+
+### 72.10.2 Delete
+
+- Removes rt-objects from the MHEG engine. This may be used to release resources.
+- List of (Rt-Target Param).
+
+## 72.11 Rt-objects running behaviour
+
+Table 25/T.171 – Overview of Rt-objects running behaviour
+
+|                                                                                               |
+|-----------------------------------------------------------------------------------------------|
+| <b>Run</b> ::= Rt-Target Param+, Number Of Performances Param?                                |
+| <b>Number Of Performances Param</b> ::= Number Of Performances   Number Of Performances Macro |
+| <b>Number Of Performances Macro</b> ::= Macro Def ID, Number Of Performances?                 |
+| <b>Number Of Performances</b> ::= Generic Integer   <i>#infinite</i>                          |
+| <b>Stop</b> ::= Rt-Target Param+                                                              |
+
+### 72.11.1 Run
+
+- Enables the presentation of rt-objects by the presentation process.
+- Sequence of (Rt-Target Param+, Number of Performances Param?).
+
+### 72.11.2 Number of Performances Param
+
+- Parameter of Number of Performances.
+- Choice between (Number of Performances, Number of Performances Macro).
+
+### 72.11.3 Number Of Performances Macro
+
+- Allows the specification of a macro parameter instead of a specified Number of Performances value.
+- Sequence of (Macro Def ID, Number of Performances?).
+
+### 72.11.4 Number of Performances
+
+- Specifies the number of performances.
+- Choice between (Generic Integer, infinite).
+
+### 72.11.5 Stop
+
+- Sets the running status to “not running” and stops possible user effects.
+- List of (Rt-Target Param).
+
+## 72.12 Rt-script passing parameter behaviour
+
+Table 26/T.171 – Overview of Rt-script passing parameter behaviour
+
+**Set Parameters** ::= Rt-Script Target Param+, Passing Param\*
+
+**Passing Param** ::= Passing | Passing Macro
+
+**Passing Macro** ::= Macro Def ID, Passing?
+
+**Passing** ::= Generic Value | Content Object Ref
+
+### 72.12.1 Set Parameters
+
+- Offers means to pass parameters to an rt-script.
+- Sequence of (Rt-Script Target Param+, Passing Param\*).
+
+### 72.12.2 Passing Param
+
+- Parameter of Passing.
+- Choice between (Passing, Passing Macro).
+
+### 72.12.3 Passing Macro
+
+- Allows the specification of a macro parameter instead of a specified Passing value.
+- Sequence of (Macro Def ID, Passing?).
+
+### 72.12.4 Passing
+
+- Parameters to be passed to an rt-script.
+- Choice between (Generic Value, Content Object Ref).
+
+## 72.13 Sockets presentation and structural dynamism behaviour
+
+Table 27/T.171 – Overview of Sockets presentation and structural dynamism behaviour
+
+**Plug** ::= Socket Target Param+, Plug In Param
+
+**Plug In Param** ::= Plug In | Plug In Macro
+
+**Plug In Macro** ::= Macro Def ID, Plug In?
+
+**Plug In** ::= Rt-Component Reference | Component Object Reference | Label | Evaluated Reference
+
+### 72.13.1 Plug
+
+- Attaches an rt-component or a label to a socket.
+- Sequence of (Socket Target Param+, Plug In Param).
+
+### 72.13.2 Plug In Param
+
+- Parameter of Plug In.
+- Choice between (Plug In, Plug In Macro).
+
+### 72.13.3 Plug In Macro
+
+- Allows the specification of a macro parameter instead of a specified Plug In value.
+- Sequence of (Macro Def ID, Plug In?).
+
+#### 72.13.4 Plug In
+
+- Specifies the information to be plugged into a socket.
+- Choice between (Rt-Component Reference, Component Object Reference, Label, Evaluated Reference).
+
+### 72.14 Rt-components rps assignment behaviour
+
+**Table 28/T.171 – Overview of Rt-components RPS assignment behaviour**
+
+**Set RPS Assignment** ::= Rt-Component Target Param+, RPS Assignment Param
+
+**RPS Assignment Param** ::= RPS Assignment | RPS Assignment Macro
+
+**RPS Assignment Macro** ::= Macro Def ID, RPS Assignment?
+
+#### 72.14.1 Set RPS Assignment
+
+- Sets the RPS assignment of the target.
+- Sequence of (Rt-Component Target Param+, RPS Assignment Param).
+
+#### 72.14.2 RPS Assignment Param
+
+- Parameter of RPS Assignment.
+- Choice between (RPS Assignment, RPS Assignment Macro).
+
+#### 72.14.3 RPS Assignment Macro
+
+- Allows the specification of a macro parameter instead of a specified RPS Assignment value.
+- Sequence of (Macro Def ID, RPS Assignment?).
+
+### 72.15 Rt-components perceptability behaviour
+
+**Table 29/T.171 – Overview of Rt-components perceptability behaviour**
+
+**Set Perceptability** ::= Rt-Component Target Param+, Perceptability Param, Transition Duration Param?
+
+**Perceptability Param** ::= Generic Ratio Param
+
+**Set Presentation Priority** ::=
+
+Rt-Component Target Param+, Presentation Priority Param, Transition Duration Param?
+
+**Presentation Priority Param** ::= Presentation Priority | Presentation Priority Macro
+
+**Presentation Priority Macro** ::= Macro Def ID, Presentation Priority?
+
+#### 72.15.1 Set Perceptability
+
+- This action enables to change the perceptability of an rt-component or a root rt-component.
+- Sequence of (Rt-Component Target Param+, Perceptability Param, Transition Duration Param?).
+
+#### 72.15.2 Perceptability Param
+
+- Perceptability to be assigned to rt-component.
+- Generic Ratio Param.
+
+### 72.15.3 Set Presentation Priority
+
+- This action enables to change the presentation priority of an rt-component or a root rt-component.
+- Sequence of (Rt-Component Target Param+, Presentation Priority Param, Transition Duration Param?).
+
+### 72.15.4 Presentation Priority Param
+
+- Parameter of Presentation Priority.
+- Choice between (Presentation Priority, Presentation Priority Macro).
+
+### 72.15.5 Presentation Priority Macro
+
+- Allows the specification of a macro parameter instead of a specified Presentation Priority value.
+- Sequence of (Macro Def ID, Presentation Priority?).
+
+## 72.16 Rt-components temporal behaviour
+
+**Table 30/T.171 – Overview of Rt-components temporal behaviour**
+
+|                                                                                                    |
+|----------------------------------------------------------------------------------------------------|
+| <b>Set OVD</b> ::= Rt-Component Target Param+, Initial Point Spec Param, Terminal Point Spec Param |
+| <b>Set CTP</b> ::= Rt-Component Target Param+, Current Point Spec Param                            |
+| <b>Set Temporal Termination</b> ::= Rt-Target Param+, Temporal Termination Param                   |
+| <b>Temporal Termination Param</b> ::= Temporal Termination   Temporal Termination Macro            |
+| <b>Temporal Termination Macro</b> ::= Macro Def ID, Temporal Termination?                          |
+| <b>Set PVD Position</b> ::= Socket Target Param+, Temporal Position Param                          |
+| <b>Temporal Position Param</b> ::= Point Spec Param                                                |
+| <b>Set GTF</b> ::= Rt-Component Target Param+, GTF Param                                           |
+| <b>GTF Param</b> ::= GF Param                                                                      |
+| <b>Set Timestones</b> ::= Rt-Component Target Param+, Timestone Spec Param+                        |
+| <b>Timestone Spec Param</b> ::= Timestone Spec   Timestone Spec Macro                              |
+| <b>Timestone Spec Macro</b> ::= Macro Def ID, Timestone Spec?                                      |
+| <b>Timestone Spec</b> ::= Timestone+, Update Command                                               |
+| <b>Timestone</b> ::= Timestone ID, Timestone Position, Number Of Repetitions                       |
+| <b>Timestone Position</b> ::= Point Spec                                                           |
+| <b>Number Of Repetitions</b> ::= Generic Integer   <i>#infinite</i>                                |
+
+### 72.16.1 Set OVD
+
+- The first Point Spec Param specifies the initial temporal position of the OVD. The second specifies the terminal temporal position of the OVD.
+- Sequence of (Rt-Component Target Param+, Initial Point Spec Param, Terminal Point Spec Param).
+
+### 72.16.2 Set CTP
+
+- This action specifies the CTP within the OVD.
+- Sequence of (Rt-Component Target Param+, Current Point Spec Param).
+
+### 72.16.3 Set Temporal Termination
+
+- Specifies the action to be performed once the terminal temporal position of the rt-component is reached.
+- Sequence of (Rt-Target Param+, Temporal Termination Param).
+
+#### **72.16.4 Temporal Termination Param**
+
+- Parameter of Temporal Termination.
+- Choice between (Temporal Termination, Temporal Termination Macro).
+
+#### **72.16.5 Temporal Termination Macro**
+
+- Allows the specification of a macro parameter instead of a specified Temporal Termination value.
+- Sequence of (Macro Def ID, Temporal Termination?).
+
+#### **72.16.6 Set PVD Position**
+
+- Binds child PVDs to their parent OVD.
+- Sequence of (Socket Target Param+, Temporal Position Param).
+
+#### **72.16.7 Temporal Position Param**
+
+- Specifies temporal position either by an absolute value along a temporal axis or a relative value against a temporal duration.
+- Point Spec Param.
+
+#### **72.16.8 Set GTF**
+
+- This action defines the presentation speed of an rt-component.
+- Sequence of (Rt-Component Target Param+, GTF Param).
+
+#### **72.16.9 GTF Param**
+
+- Generic ratio or default-GF.
+- GF Param.
+
+#### **72.16.10 Set Timestones**
+
+- Sets timestones.
+- Sequence of (Rt-Component Target Param+, Timestone Spec Param+).
+
+#### **72.16.11 Timestone Spec Param**
+
+- Parameter of Timestone Spec.
+- Choice between (Timestone Spec, Timestone Spec Macro).
+
+#### **72.16.12 Timestone Spec Macro**
+
+- Allows the specification of a macro parameter instead of a specified Timestone Spec value.
+- Sequence of (Macro Def ID, Timestone Spec?).
+
+#### **72.16.13 Timestone Spec**
+
+- A set of timestones and the update commands to be applied.
+- Sequence of (Timestone+, Update Command).
+
+#### **72.16.14 Timestone**
+
+- A pair of a timestone identifier and a timestone position and the number of repetitions.
+- Sequence of (Timestone ID, Timestone Position, Number of Repetitions).
+
+#### **72.16.15 Timestone Position**
+
+- Specified by point specification.
+- Point Spec.
+
+#### **72.16.16 Number Of Repetitions**
+
+- Specifies the number of repetitions.
+- Choice between (Generic Integer, infinite).
+
+## 72.17 Rt-components spatial behaviour
+
+**Table 31/T.171 – Overview of Rt-components spatial behaviour**
+
+|                                                                                                                    |
+|--------------------------------------------------------------------------------------------------------------------|
+| <b>Set Aspect Ratio</b> ::= Rt-Component Target Param+, Aspect Ratio Param                                         |
+| <b>Aspect Ratio Param</b> ::= Aspect Ratio   Aspect Ratio Macro                                                    |
+| <b>Aspect Ratio Macro</b> ::= Macro Def ID, Aspect Ratio?                                                          |
+| <b>Set Resizing Strategy</b> ::= Rt-Composite Target Param+, Resizing Strategy Param                               |
+| <b>Resizing Strategy Param</b> ::= Resizing Strategy   Resizing Strategy Macro                                     |
+| <b>Resizing Strategy Macro</b> ::= Macro Def ID, Resizing Strategy?                                                |
+| <b>Set OVS Proj Strategy</b> ::= Rt-Component Target Param+, OVS Proj Strategy Param                               |
+| <b>OVS Proj Strategy Param</b> ::= OVS Proj Strategy   OVS Proj Strategy Macro                                     |
+| <b>OVS Proj Strategy Macro</b> ::= Macro Def ID, OVS Proj Strategy?                                                |
+| <b>Set OVS</b> ::= Rt-Component Target Param+, Size Spec Param, Transition Duration Param?                         |
+| <b>Set OAP</b> ::= Rt-Component Target Param+, OAP Param                                                           |
+| <b>OAP Param</b> ::= Spatial Position Spec Param                                                                   |
+| <b>Set OVS Position</b> ::= Rt-Component Target Param+, OVS Position Param, Transition Duration Param?             |
+| <b>OVS Position Param</b> ::= Spatial Position Spec Param                                                          |
+| <b>Set PAP</b> ::= Rt-Component Target Param+, PAP Param                                                           |
+| <b>PAP Param</b> ::= Spatial Position Spec Param                                                                   |
+| <b>Set PVS Position</b> ::= Rt-Component Target Param+, PVS Position Param, Transition Duration Param?             |
+| <b>PVS Position Param</b> ::= Spatial Position Spec Param                                                          |
+| <b>Set GSF</b> ::= Rt-Component Target Param+, GSF Param, Transition Duration Param?                               |
+| <b>GSF Param</b> ::= GF Param                                                                                      |
+| <b>Set User Spatial Control</b> ::= Rt-Component Target Param+, Spatial Control Param+, User Spatial Control Param |
+| <b>User Spatial Control Param</b> ::= User Spatial Control   User Spatial Control Macro                            |
+| <b>User Spatial Control Macro</b> ::= Macro Def ID, User Spatial Control?                                          |
+
+### 72.17.1 Set Aspect Ratio
+
+- Specifies whether the OS is projected with the aspect ratio preserved or not.
+- Sequence of (Rt-Component Target Param+, Aspect Ratio Param).
+
+### 72.17.2 Aspect Ratio Param
+
+- Specifies the aspect ratio preservation.
+- Choice between (Aspect Ratio, Aspect Ratio Macro).
+
+### 72.17.3 Aspect Ratio Macro
+
+- Allows the specification of a macro parameter instead of a specified Aspect Ratio value.
+- Sequence of (Macro Def ID, Aspect Ratio?).
+
+#### **72.17.4 Set Resizing Strategy**
+
+- Specifies the OS resizing strategy of an rt-composite.
+- Sequence of (Rt-Composite Target Param+, Resizing Strategy Param).
+
+#### **72.17.5 Resizing Strategy Param**
+
+- Specifies the resizing strategy.
+- Choice between (Resizing Strategy, Resizing Strategy Macro).
+
+#### **72.17.6 Resizing Strategy Macro**
+
+- Allows the specification of a macro parameter instead of a specified Resizing Strategy value.
+- Sequence of (Macro Def ID, Resizing Strategy?).
+
+#### **72.17.7 Set OVS Proj Strategy**
+
+- Specifies the OVS Proj Strategy. Choice between “fixed” or “calculated”.
+- Sequence of (Rt-Component Target Param+, OVS Proj Strategy Param).
+
+#### **72.17.8 OVS Proj Strategy Param**
+
+- Parameter of OVS Proj Strategy.
+- Choice between (OVS Proj Strategy, OVS Proj Strategy Macro).
+
+#### **72.17.9 OVS Proj Strategy Macro**
+
+- Allows the specification of a macro parameter instead of a specified OVS Proj Strategy value.
+- Sequence of (Macro Def ID, OVS Proj Strategy?).
+
+#### **72.17.10 Set OVS**
+
+- Set the OVS directly or indirectly depending on the OVS Proj Strategy attribute.
+- Sequence of (Rt-Component Target Param+, Size Spec Param, Transition Duration Param?).
+
+#### **72.17.11 Set OAP**
+
+- Sets the OAP.
+- Sequence of (Rt-Component Target Param+, OAP Param).
+
+#### **72.17.12 OAP Param**
+
+- May be specified as an absolute value or a relative value.
+- Spatial Position Spec Param.
+
+#### **72.17.13 Set OVS Position**
+
+- Sets the OVS position.
+- Sequence of (Rt-Component Target Param+, OVS Position Param, Transition Duration Param?).
+
+#### **72.17.14 OVS Position Param**
+
+- May be specified as an absolute value or a relative value.
+- Spatial Position Spec Param.
+
+#### **72.17.15 Set PAP**
+
+- Sets the PAP.
+- Sequence of (Rt-Component Target Param+, PAP Param).
+
+#### 72.17.16 PAP Param
+
+- May be specified as an absolute value or a relative value.
+- Spatial Position Spec Param.
+
+#### 72.17.17 Set PVS Position
+
+- Sets the PVS position.
+- Sequence of (Rt-Component Target Param+, PVS Position Param, Transition Duration Param?).
+
+#### 72.17.18 PVS Position Param
+
+- May be specified as an absolute value or a relative value.
+- Spatial Position Spec Param.
+
+#### 72.17.19 Set GSF
+
+- Sets GSF.
+- Sequence of (Rt-Component Target Param+, GSF Param, Transition Duration Param?).
+
+#### 72.17.20 GSF Param
+
+- A generic ratio.
+- GF Param.
+
+#### 72.17.21 Set User Spatial Control
+
+- Sets one of the user spatial controls.
+- Sequence of (Rt-Component Target Param+, Spatial Control Param+, User Spatial Control Param).
+
+#### 72.17.22 User Spatial Control Param
+
+- Choice between “allowed” and “not allowed”.
+- Choice between (User Spatial Control, User Spatial Control Macro).
+
+#### 72.17.23 User Spatial Control Macro
+
+- Allows the specification of a macro parameter instead of a specified User Spatial Control value.
+- Sequence of (Macro Def ID, User Spatial Control?).
+
+### 72.18 Rt-components audible behaviour
+
+**Table 32/T.171 – Overview of Rt-components audible behaviour**
+
+**Set CV** ::= Rt-Content Target Param+, CV Param, Transition Duration Param?
+
+**CV Param** ::= Current Point Spec Param
+
+**Set GVF** ::= GVF Target, GVF Param, Transition Duration Param?
+
+**GVF Target** ::= Rt-Composite Targets Param | Channel Targets Param
+
+**Rt-Composite Targets Param** ::= Rt-Composite Target Param+
+
+**Channel Targets Param** ::= Channel Target Param+
+
+**GVF Param** ::= GF Param
+
+#### 72.18.1 Set CV
+
+- Specifies the CV of an rt-content.
+- Sequence of (Rt-Content Target Param+, CV Param, Transition Duration Param?).
+
+#### 72.18.2 CV Param
+
+- Specified as an absolute value, a relative value, an original point factor or a current point factor.
+- Current Point Spec Param.
+
+#### 72.18.3 Set GVF
+
+- This action specifies the GVF of an rt-composite or a channel.
+- Sequence of (GVF Target, GVF Param, Transition Duration Param?).
+
+#### 72.18.4 GVF Target
+
+- Targets for GVF.
+- Choice between (Rt-Composite Targets Param, Channel Targets Param).
+
+#### 72.18.5 Rt-Composite Targets Param
+
+- Targets for GVF.
+- List of (Rt-Composite Target Param).
+
+#### 72.18.6 Channel Targets Param
+
+- Targets for GVF.
+- List of (Channel Target Param).
+
+#### 72.18.7 GVF Param
+
+- GVF value to be assigned.
+- GF Param.
+
+### 72.19 Rt-mux stream choice behaviour
+
+Table 33/T.171 – Overview of Rt-mux stream choice behaviour
+
+**Set Stream Choice** ::= Rt-Mux Target Param+, Stream Spec Param\*
+
+**Stream Spec Param** ::= Stream Spec | Stream Spec Macro
+
+**Stream Spec Macro** ::= Macro Def ID, Stream Spec?
+
+**Stream Spec** ::= Stream ID Reference\*, Update Command
+
+#### 72.19.1 Set Stream Choice
+
+- This action specifies a list of streams to be chosen in the multiplexed data and to be assigned to the target.
+- Sequence of (Rt-Mux Target Param+, Stream Spec Param\*).
+
+#### 72.19.2 Stream Spec Param
+
+- Parameter of Stream Spec.
+- Choice between (Stream Spec, Stream Spec Macro).
+
+#### 72.19.3 Stream Spec Macro
+
+- Allows the specification of a macro parameter instead of a specified Stream Spec value.
+- Sequence of (Macro Def ID, Stream Spec?).
+
+#### 72.19.4 Stream Spec
+
+- Combination of a list of stream ID and an update command.
+- Sequence of (Stream ID Reference\*, Update Command).
+
+#### 72.20 Interaction behaviour
+
+**Table 34/T.171 – Overview of Interaction behaviour**
+
+|                                                                                                                                                    |
+|----------------------------------------------------------------------------------------------------------------------------------------------------|
+| <b>Interaction Status Param</b> ::= Interaction Status   Interaction Status Macro                                                                  |
+| <b>Interaction Status Macro</b> ::= Macro Def ID, Interaction Status?                                                                              |
+| <b>Min Interact Required Param</b> ::= Min Interact Required   Min Interact Required Macro                                                         |
+| <b>Min Interact Required Macro</b> ::= Macro Def ID, Min Interact Required?                                                                        |
+| <b>Max Interact Required Param</b> ::= Max Interact Required   Max Interact Required Macro                                                         |
+| <b>Max Interact Required Macro</b> ::= Macro Def ID, Max Interact Required?                                                                        |
+| <b>Set Interaction Ability</b> ::=<br>Rt-Component Target Param+, Interaction Type Param, Min Interact Required Param, Max Interact Required Param |
+| <b>Set Interaction Status</b> ::= Rt-Component Target Param+, Interaction Type Param, Interaction Status Param                                     |
+
+##### 72.20.1 Interaction Status Param
+
+- Parameter of Interaction Status.
+- Choice between (Interaction Status, Interaction Status Macro).
+
+##### 72.20.2 Interaction Status Macro
+
+- Allows the specification of a macro parameter instead of a specified Interaction Status value.
+- Sequence of (Macro Def ID, Interaction Status?).
+
+##### 72.20.3 Min Interact Required Param
+
+- Parameter of Min Interact Required.
+- Choice between (Min Interact Required, Min Interact Required Macro).
+
+##### 72.20.4 Min Interact Required Macro
+
+- Allows the specification of a macro parameter instead of a specified Min Interact Required value.
+- Sequence of (Macro Def ID, Min Interact Required?).
+
+##### 72.20.5 Max Interact Required Param
+
+- An integer greater than or equal to 0 to indicate the maximum interaction required for an *rt-component*.
+- Choice between (Max Interact Required, Max Interact Required Macro).
+
+##### 72.20.6 Max Interact Required Macro
+
+- Allows the specification of a macro parameter instead of a specified Max Interact Required value.
+- Sequence of (Macro Def ID, Max Interact Required?).
+
+##### 72.20.7 Set Interaction Ability
+
+- This action may be targeted to *rt-components* to initialise or modify their interactivity behaviour.
+- Sequence of (Rt-Component Target Param+, Interaction Type Param, Min Interact Required Param, Max Interact Required Param).
+
+## 72.20.8 Set Interaction Status
+
+- This action assigns a value to the selection status of an rt-component.
+- Sequence of (Rt-Component Target Param+, Interaction Type Param, Interaction Status Param).
+
+## 72.21 Rt-components style behaviour
+
+**Table 35/T.171 – Overview of Rt-components style behaviour**
+
+**Set Style** ::= Rt-Component Target Param+, Catalogued Style Param, Additional Information Param?
+
+**Catalogued Style Param** ::= Catalogued Style | Catalogued Style Macro
+
+**Catalogued Style Macro** ::= Macro Def ID, Catalogued Style?
+
+**Additional Information Param** ::= Generic Value Param
+
+### 72.21.1 Set Style
+
+- Specifies a style to be applied to a target.
+- Sequence of (Rt-Component Target Param+, Catalogued Style Param, Additional Information Param?).
+
+### 72.21.2 Catalogued Style Param
+
+- Parameter of Catalogued Style.
+- Choice between (Catalogued Style, Catalogued Style Macro).
+
+### 72.21.3 Catalogued Style Macro
+
+- Allows the specification of a macro parameter instead of a specified Catalogued Style value.
+- Sequence of (Macro Def ID, Catalogued Style?).
+
+### 72.21.4 Additional Information Param
+
+- Specifies some additional information required for a style.
+- Generic Value Param.
+
+## 72.22 Rt-contents anchor behaviour
+
+**Table 36/T.171 – Overview of Rt-contents anchor behaviour**
+
+**Attach Anchor** ::= Rt-Content Target Param+, Anchor Spec Param+
+
+**Anchor Spec Param** ::= Anchor Spec | Anchor Spec Macro
+
+**Anchor Spec Macro** ::= Macro Def ID, Anchor Spec?
+
+**Anchor Spec** ::= Anchor+, Update Command
+
+**Anchor** ::= Rt-Content Reference | Evaluated Reference
+
+### 72.22.1 Attach Anchor
+
+- Attaches anchors to rt-contents.
+- Sequence of (Rt-Content Target Param+, Anchor Spec Param+).
+
+### 72.22.2 Anchor Spec Param
+
+- Parameter of Anchor Spec.
+- Choice between (Anchor Spec, Anchor Spec Macro).
+
+### 72.22.3 Anchor Spec Macro
+
+- Allows the specification of a macro parameter instead of a specified Anchor Spec value.
+- Sequence of (Macro Def ID, Anchor Spec?).
+
+### 72.22.4 Anchor Spec
+
+- A pair of anchors and the update command.
+- Sequence of (Anchor+, Update Command).
+
+### 72.22.5 Anchor
+
+- Specifies an anchor.
+- Choice between (Rt-Content Reference, Evaluated Reference).
+
+## 72.23 Channel availability behaviour
+
+**Table 37/T.171 – Overview of Channel availability behaviour**
+
+**New Channel** ::= Channel Target Param+
+
+**Delete Channel** ::= Channel Target Param+
+
+### 72.23.1 New Channel
+
+- This action creates channels.
+- List of (Channel Target Param).
+
+### 72.23.2 Delete Channel
+
+- This action removes channels.
+- List of (Channel Target Param).
+
+## 72.24 Channel perceptability behaviour
+
+**Table 38/T.171 – Overview of Channel perceptability behaviour**
+
+**Set Channel Perceptability** ::= Channel Target Param+, Channel Perceptability Param
+
+**Channel Perceptability Param** ::= Channel Perceptability | Channel Perceptability Macro
+
+**Channel Perceptability Macro** ::= Macro Def ID, Channel Perceptability?
+
+### 72.24.1 Set Channel Perceptability
+
+- This action changes the channel perceptability of a target.
+- Sequence of (Channel Target Param+, Channel Perceptability Param).
+
+### 72.24.2 Channel Perceptability Param
+
+- Parameter of Channel Perceptability.
+- Choice between (Channel Perceptability, Channel Perceptability Macro).
+
+### 72.24.3 Channel Perceptability Macro
+
+- Allows the specification of a macro parameter instead of a specified Channel Perceptability value.
+- Sequence of (Macro Def ID, Channel Perceptability?).
+
+### 72.25 Channel presentation space behaviour
+
+**Table 39/T.171 – Overview of Channel presentation space behaviour**
+
+|                                                                                   |
+|-----------------------------------------------------------------------------------|
+| <b>Set CPS</b> ::= Channel Target Param+, CPS Initialisation Param?               |
+| <b>CPS Initialisation Param</b> ::= CPS Initialisation   CPS Initialisation Macro |
+| <b>CPS Initialisation Macro</b> ::= Macro Def ID, CPS Initialisation?             |
+| <b>CPS Initialisation</b> ::= CPS Duration?, CPS Size?                            |
+| <b>CPS Duration</b> ::= Integer   <i>#infinite</i>   Evaluated Integer            |
+| <b>CPS Size</b> ::= Size   Evaluated List                                         |
+
+#### 72.25.1 Set CPS
+
+- This action specifies an CPS of the target.
+- Sequence of (Channel Target Param+, CPS Initialisation Param?).
+
+#### 72.25.2 CPS Initialisation Param
+
+- Parameter of CPS Initialisation.
+- Choice between (CPS Initialisation, CPS Initialisation Macro).
+
+#### 72.25.3 CPS Initialisation Macro
+
+- Allows the specification of a macro parameter instead of a specified CPS Initialisation value.
+- Sequence of (Macro Def ID, CPS Initialisation?).
+
+#### 72.25.4 CPS Initialisation
+
+- Specifies the duration and the size of the CPS.
+- Sequence of (CPS Duration?, CPS Size?).
+
+#### 72.25.5 CPS Duration
+
+- Specifies the duration of the CPS.
+- Choice between (Integer, infinite, Evaluated Integer).
+
+#### 72.25.6 CPS Size
+
+- Specifies the spatial size of the CPS.
+- Choice between (Size, Evaluated List).
+
+### 72.26 Channels and rt-components events behaviour
+
+**Table 40/T.171 – Overview of Channels and rt-components events behaviour**
+
+|                                                                                     |
+|-------------------------------------------------------------------------------------|
+| <b>Set Event</b> ::= Rt-Component Channel Tg Param+, Event Param, Event Data Param? |
+| <b>Event Param</b> ::= Generic List Param                                           |
+| <b>Event Data Param</b> ::= Generic Value Param                                     |
+
+### 72.26.1 Set Event
+
+- The event identifier attribute of the target is set to the specified value.
+- Sequence of (Rt-Component Channel Tg Param+, Event Param, Event Data Param?).
+
+### 72.26.2 Event Param
+
+- Specifies an event.
+- Generic List Param.
+
+### 72.26.3 Event Data Param
+
+- Specifies the data associated with an event.
+- Generic Value Param.
+
+## 73 Elementary Actions
+
+### 73.1 List of elementary actions
+
+**Table 41/T.171 – Overview of list of elementary actions**
+
+#### **Elementary Action ::=**
+
+Set Event | Set CPS | Set Channel Perceptability | New Channel | Delete Channel | Attach Anchor | Get Style | Set Style | Set Interaction Ability | Set Interaction Status | Set Stream Choice | Set CV | Set GVF | Set Aspect Ratio | Set Resizing Strategy | Set OVS | Set OAP | Set OVS Position | Set PAP | Set PVS Position | Set GSF | Set User Spatial Control | Set OVD | Set CTP | Set Temporal Termination | Set PVD Position | Set GTF | Set Timestones | Set Perceptability | Set Presentation Priority | Set RPS Assignment | Plug | Set Parameters | Run | Stop | New | Delete | Copy | Set Data | Add | Subtract | Link Abort | Activate | Deactivate | Prepare | Destroy | Catalogued Elementary Action | Set Catalogued Attribute | Set Alias | Return | Delay | Extensibility Provision
+
+#### 73.1.1 Elementary Action
+
+- This Recommendation defines a list of elementary actions that may be included in an action object to modify the behaviour of MHEG entities.
+- Choice between (Set Event, Set CPS, Set Channel Perceptability, New Channel, Delete Channel, Attach Anchor, Get Style, Set Style, Set Interaction Ability, Set Interaction Status, Set Stream Choice, Set CV, Set GVF, Set Aspect Ratio, Set Resizing Strategy, Set OVS, Set OAP, Set OVS Position, Set PAP, Set PVS Position, Set GSF, Set User Spatial Control, Set OVD, Set CTP, Set Temporal Termination, Set PVD Position, Set GTF, Set Timestones, Set Perceptability, Set Presentation Priority, Set RPS Assignment, Plug, Set Parameters, Run, Stop, New, Delete, Copy, Set Data, Add, Subtract, Link Abort, Activate, Deactivate, Prepare, Destroy, Catalogued Elementary Action, Set Catalogued Attribute, Set Alias, Return, Delay, Extensibility Provision).
+
+## 73.2 MHEG entity, data, stream, macro parameter and identification useful definitions
+
+Table 42/T.171 – Overview of MHEG entity, data, stream and macro parameter, identification useful definitions
+
+|                                                        |
+|--------------------------------------------------------|
+| <b>Using-Application</b> ::= <i>\$NULL</i>             |
+| <b>Alias</b> ::= String                                |
+| <b>Identifier</b> ::= Integer                          |
+| <b>Index</b> ::= Integer                               |
+| <b>Tail Param</b> ::= Tail   Tail Macro                |
+| <b>Tail Macro</b> ::= Macro Def ID, Tail?              |
+| <b>Tail</b> ::= Index*                                 |
+| <b>External ID</b> ::= Public ID?, System ID?          |
+| <b>Public ID</b> ::= <i>\$PrintableString</i>          |
+| <b>System ID</b> ::= <i>\$OCTET STRING</i>             |
+| <b>Null-Data</b> ::= <i>\$NULL</i>                     |
+| <b>Mheg ID</b> ::= Application ID?, Mh Number          |
+| <b>Application ID</b> ::= <i>\$OCTET STRING</i>        |
+| <b>Mh Number</b> ::= Identifier                        |
+| <b>Null-Mh</b> ::= <i>\$NULL</i>                       |
+| <b>Stream ID</b> ::= Tail                              |
+| <b>Rt-Number</b> ::= Identifier                        |
+| <b>Null-Root-Rt</b> ::= <i>\$NULL</i>                  |
+| <b>Socket Identification</b> ::= Socket ID   Alias     |
+| <b>Socket ID</b> ::= Root Rt-Composite Reference, Tail |
+| <b>Channel ID</b> ::= Identifier                       |
+| <b>Default-Channel</b> ::= <i>\$NULL</i>               |
+| <b>Macro Def ID</b> ::= String   Integer               |
+
+### 73.2.1 Using-Application
+
+- The using application is identified by a reserved identifier: “Using-Application”.
+- NULL.
+
+### 73.2.2 Alias
+
+- Identification of an MHEG entity, a data or a stream. It is a sequence of alphanumeric characters which is used as a convenient substitute for the other addressing mechanism. It is for the using application to map this name to a physical address.
+- String.
+
+### 73.2.3 Identifier
+
+- Identification of an MHEG entity.
+- Integer.
+
+#### **73.2.4 Index**
+
+- Identification of an inner element. The indexes are numbered from 1 to n by default.
+- Integer.
+
+#### **73.2.5 Tail Param**
+
+- Parameter of Tail.
+- Choice between (Tail, Tail Macro).
+
+#### **73.2.6 Tail Macro**
+
+- Allows the specification of a macro parameter instead of a specified Tail value.
+- Sequence of (Macro Def ID, Tail?).
+
+#### **73.2.7 Tail**
+
+- Identification of an inner element within a hierarchy. The list of indexes designs a path from an outer entity to an inner element.
+- List of (Index).
+
+#### **73.2.8 External ID**
+
+- Identification of an external information (e.g. an MHEG object, a content data) as defined for by ISO 9070 and ISO 8879.
+
+The technique for reference to external information is based on:
+
+The techniques used in ISO 8879 for “formal public identifiers”.
+
+International Standard ISO 9070 “Registration procedures for public text owner identifier” which provides both ASN.1 and SGML notation for the representation of registered owner identifiers.
+
+The presence of at least one of the two fields is mandatory.
+
+- Sequence of (Public ID?, System ID?).
+
+#### **73.2.9 Public ID**
+
+- Character string whose syntax is given by subclause 10.2 of ISO 8879:1986.  
+Recommendation T.171 uses a simplification of ISO 9070 Informative Annex D shall be used for the encoding of the public identifier.
+- PrintableString.
+
+#### **73.2.10 System ID**
+
+- The system identifier may be used to identify a particular file within the system. It may also be used to indicate the system which supplies the object. This information may be used to describe a database or telecommunications request for an information.
+- OCTET STRING.
+
+#### **73.2.11 Null-Data**
+
+- The null data is identified by a reserved identifier: “Null-Data”.
+- NULL.
+
+#### **73.2.12 Mheg ID**
+
+- Identification of an MHEG interchanged object.
+- Sequence of (Application ID?, Mh Number).
+
+#### **73.2.13 Application ID**
+
+- Identification of the application supplying the object. The semantics of the identification are defined by the using application.
+- OCTET STRING.
+
+#### **73.2.14 MH Number**
+
+- Unique identification of the object within the application. A reserved MH-number is used to address a null object: “Null-MH”.
+- Identifier.
+
+#### **73.2.15 Null-MH**
+
+- The null MHEG object is identified by a reserved identifier: “Null-MH”.
+- NULL.
+
+#### **73.2.16 Stream ID**
+
+- Unique identification of a stream within a multiplex.
+- Tail.
+
+#### **73.2.17 Rt Number**
+
+- Unique identification of a root rt-object created from a given model object.
+- Identifier.
+
+#### **73.2.18 Null-Root-Rt**
+
+- The null root rt-object is identified by a reserved identifier: “Null-Root-Rt”.
+- NULL.
+
+#### **73.2.19 Socket Identification**
+
+- Identification of a socket.
+- Choice between (Socket ID, Alias).
+
+#### **73.2.20 Socket ID**
+
+- Identifier of a socket, i.e. an rt-composite element.
+- Sequence of (Root Rt-Composite Reference, Tail).
+
+#### **73.2.21 Channel ID**
+
+- Identification of a channel.
+- Identifier.
+
+#### **73.2.22 Default-Channel**
+
+- The default channel is identified by a reserved identifier: “Default-Channel”.
+- NULL.
+
+#### **73.2.23 Macro Def ID**
+
+- Identification of a macro parameter within an action.
+- Choice between (String, Integer).
+
+### 73.3 References useful definitions
+
+**Table 43/T.171 – Overview of References useful definitions**
+
+|                                                                                                                                                                                                                                                                           |
+|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| <b>Reference ::=</b><br>Null-Data   Mheg ID Reference   External ID Reference   Container Element Reference   Null-Mh   This   Stream ID Reference   Root Rt-ID Reference   Null-Root-Rt   Socket ID Reference   Channel ID Reference   Default-Channel   Alias Reference |
+| <b>Alias Reference ::=</b> Alias                                                                                                                                                                                                                                          |
+| <b>Mheg ID Reference ::=</b> Mheg ID                                                                                                                                                                                                                                      |
+| <b>External ID Reference ::=</b> External ID                                                                                                                                                                                                                              |
+| <b>Tail Reference ::=</b> Tail?, Tail Complement?                                                                                                                                                                                                                         |
+| <b>Tail Complement ::=</b> # <i>children</i>   # <i>descendants</i>                                                                                                                                                                                                       |
+| <b>Data Reference ::=</b> External ID   Null-Data   Alias Reference                                                                                                                                                                                                       |
+| <b>Mh-Reference ::=</b><br>Mheg ID Reference   External ID Reference   Container Element Reference   Null-Mh   This   Alias Reference                                                                                                                                     |
+| <b>Action Object Reference ::=</b> Mh-Reference                                                                                                                                                                                                                           |
+| <b>Link Object Reference ::=</b> Mh-Reference                                                                                                                                                                                                                             |
+| <b>Model Object Reference ::=</b> Mh-Reference                                                                                                                                                                                                                            |
+| <b>Script Object Reference ::=</b> Mh-Reference                                                                                                                                                                                                                           |
+| <b>Component Object Reference ::=</b> Mh-Reference                                                                                                                                                                                                                        |
+| <b>Content Object Ref ::=</b> Mh-Reference                                                                                                                                                                                                                                |
+| <b>Non-Mux Content Object Ref ::=</b> Mh-Reference                                                                                                                                                                                                                        |
+| <b>Multiplexed Content Object Ref ::=</b> Mh-Reference                                                                                                                                                                                                                    |
+| <b>Stream ID Reference ::=</b> Stream ID                                                                                                                                                                                                                                  |
+| <b>Composite Object Reference ::=</b> Mh-Reference                                                                                                                                                                                                                        |
+| <b>Container Object Reference ::=</b> Mh-Reference                                                                                                                                                                                                                        |
+| <b>Container Element Reference ::=</b> Container Object Reference, Tail Reference                                                                                                                                                                                         |
+| <b>This ::=</b> <i>\$NULL</i>                                                                                                                                                                                                                                             |
+| <b>Descriptor Object Reference ::=</b> Mh-Reference                                                                                                                                                                                                                       |
+| <b>Root Rt-Reference ::=</b> Root Rt-ID Reference   Null-Root-Rt   Alias Reference                                                                                                                                                                                        |
+| <b>Root Rt-ID Reference ::=</b> Model Object Reference, Rt-Number Reference                                                                                                                                                                                               |
+| <b>Rt-Number Reference ::=</b> Rt-Number   # <i>question-mark</i>   # <i>star</i>                                                                                                                                                                                         |
+| <b>Rt-Reference ::=</b> Root Rt-ID Reference   Null-Root-Rt   Socket ID Reference   Alias Reference                                                                                                                                                                       |
+| <b>Rt-Script Reference ::=</b> Rt-Script ID Reference   Null-Root-Rt   Alias Reference                                                                                                                                                                                    |
+| <b>Rt-Script ID Reference ::=</b> Script Object Reference, Rt-Number Reference                                                                                                                                                                                            |
+| <b>Root Rt-Component Reference ::=</b> Root Rt-Component ID Ref   Null-Root-Rt   Alias Reference                                                                                                                                                                          |
+| <b>Root Rt-Component ID Ref ::=</b> Component Object Reference, Rt-Number Reference                                                                                                                                                                                       |
+| <b>Rt-Component Reference ::=</b> Root Rt-Component ID Ref   Null-Root-Rt   Socket ID Reference   Alias Reference                                                                                                                                                         |
+| <b>Root Rt-Content Reference ::=</b> Root Rt-Content ID Ref   Null-Root-Rt   Alias Reference                                                                                                                                                                              |
+| <b>Root Rt-Content ID Ref ::=</b> Content Object Ref, Rt-Number Reference                                                                                                                                                                                                 |
+
+**Table 43/T.171 – Overview of References useful definitions** (*concluded*)
+
+|                                    |                                                                                      |
+|------------------------------------|--------------------------------------------------------------------------------------|
+| <b>Rt-Content Reference</b>        | ::= Root Rt-Content ID Ref   Null-Root-Rt   Socket ID Reference   Alias Reference    |
+| <b>Root Rt-Mux Reference</b>       | ::= Root Rt-Mux ID Reference   Null-Root-Rt   Alias Reference                        |
+| <b>Root Rt-Mux ID Reference</b>    | ::= Multiplexed Content Object Ref, Rt-Number Reference                              |
+| <b>Rt-Mux Reference</b>            | ::= Root Rt-Mux ID Reference   Null-Root-Rt   Socket ID Reference   Alias Reference  |
+| <b>Root Rt-Composite Reference</b> | ::= Root Rt-Composite ID Ref   Null-Root-Rt   Alias Reference                        |
+| <b>Root Rt-Composite ID Ref</b>    | ::= Composite Object Reference, Rt-Number Reference                                  |
+| <b>Rt-Composite Reference</b>      | ::= Root Rt-Composite ID Ref   Null-Root-Rt   Socket ID Reference   Alias Reference  |
+| <b>Socket Reference</b>            | ::= Socket ID Reference   Alias Reference                                            |
+| <b>Socket ID Reference</b>         | ::= Root Rt-Composite Reference, Socket Tail Reference                               |
+| <b>Socket Tail Reference</b>       | ::= Tail?, Socket Tail Complement?                                                   |
+| <b>Socket Tail Complement</b>      | ::= Tail Complement   <i>#question-mark-child</i>   <i>#question-mark-descendant</i> |
+| <b>Channel Reference</b>           | ::= Channel ID Reference   Default-Channel   Alias Reference                         |
+| <b>Channel ID Reference</b>        | ::= Channel ID                                                                       |
+| <b>Rt-Component Channel Ref</b>    | ::= Rt-Component Reference   Channel Reference                                       |
+
+### 73.3.1 Reference
+
+- A reference is used to address an MHEG entity, a data or a stream.
+- Choice between (Null-Data, Mheg ID Reference, External ID Reference, Container Element Reference, Null-Mh, This, Stream ID Reference, Root Rt-ID Reference, Null-Root-Rt, Socket ID Reference, Channel ID Reference, Default-Channel, Alias Reference).
+
+### 73.3.2 Alias Reference
+
+- Reference to a single or multiple MHEG entity or data or stream using the assigned alias.
+- Alias.
+
+### 73.3.3 Mheg ID Reference
+
+- Reference to an MHEG object using its MHEG identifier.
+- Mheg ID.
+
+### 73.3.4 External ID Reference
+
+- Reference to an MHEG entity or a data using its external identifier.
+- External ID.
+
+### 73.3.5 Tail Reference
+
+- Reference to a given element using its tail identification, a tail complement may be provided. The tail can be omitted, in which case the tail complement is applied to the outer entity itself.
+- Sequence of (Tail?, Tail Complement?).
+
+### 73.3.6 Tail Complement
+
+- The tail complement is used to reference the children (one generation) or the descendants (all generations) of the element referenced using its tail or of the outer entity if the tail is omitted.
+- Choice between (children, descendants).
+
+#### **73.3.7 Data Reference**
+
+- Reference to a data of a content or a script object using one of its possible identification.
+- Choice between (External ID, Null-Data, Alias Reference).
+
+#### **73.3.8 MH-Reference**
+
+- Reference to an MHEG object using one of its possible identifications.
+- Choice between (Mheg ID Reference, External ID Reference, Container Element Reference, Null-MH, This, Alias Reference).
+
+#### **73.3.9 Action Object Reference**
+
+- Reference to an action object.
+- MH-Reference.
+
+#### **73.3.10 Link Object Reference**
+
+- Reference to a link object.
+- MH-Reference.
+
+#### **73.3.11 Model Object Reference**
+
+- Reference to a model object. When the model object to be referenced is a composite object, “this” may be used within link and action objects to express local addressing within the composite or the container object.
+- MH-Reference.
+
+#### **73.3.12 Script Object Reference**
+
+- Reference to a script object.
+- MH-Reference.
+
+#### **73.3.13 Component Object Reference**
+
+- Reference to a component object.
+- MH-Reference.
+
+#### **73.3.14 Content Object Ref**
+
+- Reference to a content object or a multiplexed content object.
+- MH-Reference.
+
+#### **73.3.15 Non-Mux Content Object Ref**
+
+- Reference to a non-mux content object, i.e. a pure content object.
+- MH-Reference.
+
+#### **73.3.16 Multiplexed Content Object Ref**
+
+- Reference to a multiplexed content object.
+- MH-Reference.
+
+#### **73.3.17 Stream ID Reference**
+
+- Reference to a stream using its stream identifier.
+- Stream ID.
+
+#### **73.3.18 Composite Object Reference**
+
+- Reference to a composite object, “this” may be used within link and action objects to express local addressing facilities within the composite object.
+- MH-Reference.
+
+### **73.3.19 Container Object Reference**
+
+- Reference to a container object, “this” can be used within link and action objects for local addressing facilities within the composite or the container object.
+- MH-Reference.
+
+### **73.3.20 Container Element Reference**
+
+- Reference to a container element using a reference to the container object defining this element followed by a reference to the element itself.
+- Sequence of (Container Object Reference, Tail Reference).
+
+### **73.3.21 This**
+
+- When the MHEG entity to be referenced is a composite or a container object, “this” can be used within link and action objects for local addressing facilities within the composite or the container object itself.
+- NULL.
+
+### **73.3.22 Descriptor Object Reference**
+
+- Reference to a descriptor object.
+- MH-Reference.
+
+### **73.3.23 Root Rt-Reference**
+
+- Reference to a root rt-object using one of its possible identifications.
+- Choice between (Root Rt-ID Reference, Null-Root-Rt, Alias Reference).
+
+### **73.3.24 Root Rt-ID Reference**
+
+- Reference to a root rt-identifier using a reference to the model object from which it is created and a reference to the rt-number assigned to it.
+- Sequence of (Model Object Reference, Rt-Number Reference).
+
+### **73.3.25 Rt-Number Reference**
+
+- Reference to a specified root rt-object (rt-number) or to a dynamically determined root rt-object (?) or to all root rt-objects created from a given model object (\*).
+- Choice between (Rt-Number, question-mark, star).
+
+### **73.3.26 Rt-Reference**
+
+- Reference to an rt-object, i.e. either a root (rt-script, root rt-component) or a socket.
+- Choice between (Root Rt-ID Reference, Null-Root-Rt, Socket ID Reference, Alias Reference).
+
+### **73.3.27 Rt-Script Reference**
+
+- Reference to an rt-script using one of its possible identifications.
+- Choice between (Rt-Script ID Reference, Null-Root-Rt, Alias Reference).
+
+### **73.3.28 Rt-Script ID Reference**
+
+- Reference to an rt-script identifier using a reference to the model object from which it is created and a reference to the rt-number assigned to it.
+- Sequence of (Script Object Reference, Rt-Number Reference).
+
+### **73.3.29 Root Rt-Component Reference**
+
+- Reference to a root rt-component using one of its possible identifications.
+- Choice between (Root Rt-Component ID Ref, Null-Root-Rt, Alias Reference).
+
+### **73.3.30 Root Rt-Component ID Ref**
+
+- Reference to a root rt-component identifier using a reference to the model object from which it is created and a reference to the rt-number assigned to it.
+- Sequence of (Component Object Reference, Rt-Number Reference).
+
+### **73.3.31 Rt-Component Reference**
+
+- Reference to an rt-component, i.e. either a root or a socket.
+- Choice between (Root Rt-Component ID Ref, Null-Root-Rt, Socket ID Reference, Alias Reference).
+
+### **73.3.32 Root Rt-Content Reference**
+
+- Reference to a root rt-content using one of its possible identifications.
+- Choice between (Root Rt-Content ID Ref, Null-Root-Rt, Alias Reference).
+
+### **73.3.33 Root Rt-Content ID Ref**
+
+- Reference to a root rt-content identifier using a reference to the model object from which it is created and a reference to the rt-number assigned to it.
+- Sequence of (Content Object Ref, Rt-Number Reference).
+
+### **73.3.34 Rt-Content Reference**
+
+- Reference to an rt-content, i.e. either a root or a socket.
+- Choice between (Root Rt-Content ID Ref, Null-Root-Rt, Socket ID Reference, Alias Reference).
+
+### **73.3.35 Root Rt-Mux Reference**
+
+- Reference to a root rt-mux using one of its possible identifications.
+- Choice between (Root Rt-Mux ID Reference, Null-Root-Rt, Alias Reference).
+
+### **73.3.36 Root Rt-Mux ID Reference**
+
+- Reference to a root rt-mux identifier using a reference to the model object from which it is created and a reference to the rt-number assigned to it.
+- Sequence of (Multiplexed Content Object Ref, Rt-Number Reference).
+
+### **73.3.37 Rt-Mux Reference**
+
+- Reference to an rt-mux, i.e. either a root or a socket.
+- Choice between (Root Rt-Mux ID Reference, Null-Root-Rt, Socket ID Reference, Alias Reference).
+
+### **73.3.38 Root Rt-Composite Reference**
+
+- Reference to a root rt-composite using one of its possible identifications.
+- Choice between (Root Rt-Composite ID Ref, Null-Root-Rt, Alias Reference).
+
+### **73.3.39 Root Rt-Composite ID Ref**
+
+- Reference to a root rt-composite identifier using a reference to the model object from which it is created and a reference to the rt-number assigned to it.
+- Sequence of (Composite Object Reference, Rt-Number Reference).
+
+### **73.3.40 Rt-Composite Reference**
+
+- Reference to an rt-composite, i.e. either a root or a socket.
+- Choice between (Root Rt-Composite ID Ref, Null-Root-Rt, Socket ID Reference, Alias Reference).
+
+### **73.3.41 Socket Reference**
+
+- Reference to a socket, using one of its possible identifications. There is no specific reference to a null socket because a null socket, also called an empty socket, is referenced as any other sockets.
+- Choice between (Socket ID Reference, Alias Reference).
+
+#### 73.3.42 Socket ID Reference
+
+- Reference to a socket identifier using a reference to the rt-composite defining this socket followed by a reference to the socket itself. A socket is an element of an rt-composite.
+- Sequence of (Root Rt-Composite Reference, Socket Tail Reference).
+
+#### 73.3.43 Socket Tail Reference
+
+- Reference to a given socket using its tail identification, a tail complement may be provided. The tail can be omitted, in that case the socket tail complement is applied to the root rt-composite itself.
+- Sequence of (Tail?, Socket Tail Complement?).
+
+#### 73.3.44 Socket Tail Complement
+
+- The socket tail complement is used to reference the children or descendants or a single dynamically determined socket within the children (?child), or a single dynamically determined socket within the descendants (? descendant) of the socket referenced by the tail or of the root rt-composite if the tail is omitted.
+- Choice between (Tail Complement, question-mark-child, question-mark-descendant).
+
+#### 73.3.45 Channel Reference
+
+- Reference to a Channel Identifier using one of its possible identifications.
+- Choice between (Channel ID Reference, Default-Channel, Alias Reference).
+
+#### 73.3.46 Channel ID Reference
+
+- Reference to a channel using its channel identifier.
+- Channel ID.
+
+#### 73.3.47 Rt-Component Channel Ref
+
+- Reference to an rt-component or to a channel using one of its possible identifications.
+- Choice between (Rt-Component Reference, Channel Reference).
+
+### 73.4 Useful definitions of targets
+
+Table 44/T.171 – Overview of useful definitions of targets
+
+|                                                                             |
+|-----------------------------------------------------------------------------|
+| <b>Target Param</b> ::= Target   Target Macro                               |
+| <b>Target Macro</b> ::= Macro Def ID, Target?                               |
+| <b>Target</b> ::= Generic Reference                                         |
+| <b>Mh-Target Param</b> ::= Mh-Target   Mh-Target Macro                      |
+| <b>Mh-Target Macro</b> ::= Macro Def ID, Mh-Target?                         |
+| <b>Mh-Target</b> ::= Mh-Reference   Evaluated Reference                     |
+| <b>Link Target Param</b> ::= Mh-Target Param                                |
+| <b>Content Target Param</b> ::= Mh-Target Param                             |
+| <b>Rt-Target Param</b> ::= Rt-Target   Rt-Target Macro                      |
+| <b>Rt-Target Macro</b> ::= Macro Def ID, Rt-Target?                         |
+| <b>Rt-Target</b> ::= Rt-Reference   Evaluated Reference                     |
+| <b>Rt-Script Target Param</b> ::= Rt-Script Target   Rt-Script Target Macro |
+| <b>Rt-Script Target Macro</b> ::= Macro Def ID, Rt-Script Target?           |
+| <b>Rt-Script Target</b> ::= Rt-Script Reference   Evaluated Reference       |
+
+**Table 44/T.171 – Overview of useful definitions of targets (*concluded*)**
+
+|                                      |                                                             |
+|--------------------------------------|-------------------------------------------------------------|
+| <b>Rt-Component Target Param</b>     | ::= Rt-Component Target   Rt-Component Target Macro         |
+| <b>Rt-Component Target Macro</b>     | ::= Macro Def ID, Rt-Component Target?                      |
+| <b>Rt-Component Target</b>           | ::= Rt-Component Reference   Evaluated Reference            |
+| <b>Rt-Content Target Param</b>       | ::= Rt-Content Target   Rt-Content Target Macro             |
+| <b>Rt-Content Target Macro</b>       | ::= Macro Def ID, Rt-Content Target?                        |
+| <b>Rt-Content Target</b>             | ::= Rt-Content Reference   Evaluated Reference              |
+| <b>Rt-Mux Target Param</b>           | ::= Rt-Mux Target   Rt-Mux Target Macro                     |
+| <b>Rt-Mux Target Macro</b>           | ::= Macro Def ID, Rt-Mux Target?                            |
+| <b>Rt-Mux Target</b>                 | ::= Rt-Mux Reference   Evaluated Reference                  |
+| <b>Rt-Composite Target Param</b>     | ::= Rt-Composite Target   Rt-Composite Target Macro         |
+| <b>Rt-Composite Target Macro</b>     | ::= Macro Def ID, Rt-Composite Target?                      |
+| <b>Rt-Composite Target</b>           | ::= Rt-Composite Reference   Evaluated Reference            |
+| <b>Socket Target Param</b>           | ::= Socket Target   Socket Target Macro                     |
+| <b>Socket Target Macro</b>           | ::= Macro Def ID, Socket Target?                            |
+| <b>Socket Target</b>                 | ::= Socket Reference   Evaluated Reference                  |
+| <b>Return Target Param</b>           | ::= Generic Integer Param   Using-Application               |
+| <b>Channel Target Param</b>          | ::= Channel Target   Channel Target Macro                   |
+| <b>Channel Target Macro</b>          | ::= Macro Def ID, Channel Target?                           |
+| <b>Channel Target</b>                | ::= Channel Reference   Evaluated Reference                 |
+| <b>Rt-Component Channel Tg Param</b> | ::= Rt-Component Channel Tg   Rt-Component Channel Tg Macro |
+| <b>Rt-Component Channel Tg Macro</b> | ::= Macro Def ID, Rt-Component Channel Tg?                  |
+| <b>Rt-Component Channel Tg</b>       | ::= Rt-Component Channel Ref   Evaluated Reference          |
+
+#### **73.4.1 Target Param**
+
+- Parameter of Target.
+- Choice between (Target, Target Macro).
+
+#### **73.4.2 Target Macro**
+
+- Allows the specification of a macro parameter instead of a specified Target value.
+- Sequence of (Macro Def ID, Target?).
+
+#### **73.4.3 Target**
+
+- A target of an action addresses an MHEG entity using its reference.
+- Generic Reference.
+
+#### **73.4.4 MH-Target Param**
+
+- Parameter of MH-Target.
+- Choice between (MH-Target, MH-Target Macro).
+
+#### **73.4.5 MH-Target Macro**
+
+- Allows the specification of a macro parameter instead of a specified MH-Target value.
+- Sequence of (Macro Def ID, MH-Target?).
+
+#### **73.4.6 MH-Target**
+
+- An MH-target of an action addresses an MHEG object using its reference.
+- Choice between (MH-Reference, Evaluated Reference).
+
+#### **73.4.7 Link Target Param**
+
+- A link target of an action addresses a link object using its reference.
+- MH-Target Param.
+
+#### **73.4.8 Content Target Param**
+
+- A content target of an action addresses a content object using its reference.
+- MH-Target Param.
+
+#### **73.4.9 Rt-Target Param**
+
+- Parameter of Rt-Target.
+- Choice between (Rt-Target, Rt-Target Macro).
+
+#### **73.4.10 Rt-Target Macro**
+
+- Allows the specification of a macro parameter instead of a specified Rt-Target value.
+- Sequence of (Macro Def ID, Rt-Target?).
+
+#### **73.4.11 Rt-Target**
+
+- An rt-target of an action addresses an rt-object using its reference.
+- Choice between (Rt-Reference, Evaluated Reference).
+
+#### **73.4.12 Rt-Script Target Param**
+
+- Parameter of Rt-Script Target.
+- Choice between (Rt-Script Target, Rt-Script Target Macro).
+
+#### **73.4.13 Rt-Script Target Macro**
+
+- Allows the specification of a macro parameter instead of a specified Rt-Script Target value.
+- Sequence of (Macro Def ID, Rt-Script Target?).
+
+#### **73.4.14 Rt-Script Target**
+
+- An rt-script target of an action addresses an rt-script object using its reference.
+- Choice between (Rt-Script Reference, Evaluated Reference).
+
+#### **73.4.15 Rt-Component Target Param**
+
+- Parameter of Rt-Component Target.
+- Choice between (Rt-Component Target, Rt-Component Target Macro).
+
+#### **73.4.16 Rt-Component Target Macro**
+
+- Allows the specification of a macro parameter instead of a specified Rt-Component Target value.
+- Sequence of (Macro Def ID, Rt-Component Target?).
+
+#### **73.4.17 Rt-Component Target**
+
+- An rt-component target of an action addresses an rt-component object using its reference.
+- Choice between (Rt-Component Reference, Evaluated Reference).
+
+#### **73.4.18 Rt-Content Target Param**
+
+- Parameter of Rt-Content Target.
+- Choice between (Rt-Content Target, Rt-Content Target Macro).
+
+#### **73.4.19 Rt-Content Target Macro**
+
+- Allows the specification of a macro parameter instead of a specified Rt-Content Target value.
+- Sequence of (Macro Def ID, Rt-Content Target?).
+
+#### **73.4.20 Rt-Content Target**
+
+- An rt-content target of an action addresses an rt-content object using its reference.
+- Choice between (Rt-Content Reference, Evaluated Reference).
+
+#### **73.4.21 Rt-Mux Target Param**
+
+- Parameter of Rt-Mux Target.
+- Choice between (Rt-Mux Target, Rt-Mux Target Macro).
+
+#### **73.4.22 Rt-Mux Target Macro**
+
+- Allows the specification of a macro parameter instead of a specified Rt-Mux Target value.
+- Sequence of (Macro Def ID, Rt-Mux Target?).
+
+#### **73.4.23 Rt-Mux Target**
+
+- An rt-mux target of an action addresses an rt-mux object using its reference.
+- Choice between (Rt-Mux Reference, Evaluated Reference).
+
+#### **73.4.24 Rt-Composite Target Param**
+
+- Parameter of Rt-Composite Target.
+- Choice between (Rt-Composite Target, Rt-Composite Target Macro).
+
+#### **73.4.25 Rt-Composite Target Macro**
+
+- Allows the specification of a macro parameter instead of a specified Rt-Composite Target value.
+- Sequence of (Macro Def ID, Rt-Composite Target?).
+
+#### **73.4.26 Rt-Composite Target**
+
+- An rt-composite target of an action addresses an rt-composite object using its reference.
+- Choice between (Rt-Composite Reference, Evaluated Reference).
+
+#### **73.4.27 Socket Target Param**
+
+- Parameter of Socket Target.
+- Choice between (Socket Target, Socket Target Macro).
+
+#### **73.4.28 Socket Target Macro**
+
+- Allows the specification of a macro parameter instead of a specified Socket Target value.
+- Sequence of (Macro Def ID, Socket Target?).
+
+#### **73.4.29 Socket Target**
+
+- A socket target of an action addresses socket using its reference.
+- Choice between (Socket Reference, Evaluated Reference).
+
+#### **73.4.30 Return Target Param**
+
+- When provided it is up to the implementation to map the parameter to the appropriate recipient.
+- Choice between (Generic Integer Param, Using-Application).
+
+#### **73.4.31 Channel Target Param**
+
+- Parameter of Channel Target.
+- Choice between (Channel Target, Channel Target Macro).
+
+#### 73.4.32 Channel Target Macro
+
+- Allows the specification of a macro parameter instead of a specified Channel Target value.
+- Sequence of (Macro Def ID, Channel Target?).
+
+#### 73.4.33 Channel Target
+
+- A channel target of an action addresses a channel using its reference.
+- Choice between (Channel Reference, Evaluated Reference).
+
+#### 73.4.34 Rt-Component Channel Tg Param
+
+- Parameter of Rt-Component Channel Tg.
+- Choice between (Rt-Component Channel Tg, Rt-Component Channel Tg Macro).
+
+#### 73.4.35 Rt-Component Channel Tg Macro
+
+- Allows the specification of a macro parameter instead of a specified Rt-Component Channel Tg value.
+- Sequence of (Macro Def ID, Rt-Component Channel Tg?).
+
+#### 73.4.36 Rt-Component Channel Tg
+
+- An rt-component or channel target of an action addresses an rt-component or a channel using its reference.
+- Choice between (Rt-Component Channel Ref, Evaluated Reference).
+
+### 73.5 Generic value useful definitions
+
+**Table 45/T.171 – Overview of Generic value useful definitions**
+
+|                                                                          |
+|--------------------------------------------------------------------------|
+| <b>Generic Value Param</b> ::= Generic Value   Generic Value Macro       |
+| <b>Generic Value Macro</b> ::= Macro Def ID, Generic Value?              |
+| <b>Generic Value</b> ::= Value   Evaluated Value                         |
+| <b>Value</b> ::= Boolean   Numeric   Ratio   String   List   Reference   |
+| <b>Generic Boolean Param</b> ::= Generic Boolean   Generic Boolean Macro |
+| <b>Generic Boolean Macro</b> ::= Macro Def ID, Generic Boolean?          |
+| <b>Generic Boolean</b> ::= Boolean   Evaluated Boolean                   |
+| <b>Boolean</b> ::= <i>\$BOOLEAN</i>                                      |
+| <b>Generic Numeric Param</b> ::= Generic Numeric   Generic Numeric Macro |
+| <b>Generic Numeric Macro</b> ::= Macro Def ID, Generic Numeric?          |
+| <b>Generic Numeric</b> ::= Numeric   Evaluated Numeric                   |
+| <b>Numeric</b> ::= <i>\$INTEGER</i>                                      |
+| <b>Generic Integer Param</b> ::= Generic Integer   Generic Integer Macro |
+| <b>Generic Integer Macro</b> ::= Macro Def ID, Generic Integer?          |
+| <b>Generic Integer</b> ::= Integer   Evaluated Integer                   |
+| <b>Integer</b> ::= <i>\$INTEGER</i>                                      |
+| <b>Generic Ratio Param</b> ::= Generic Ratio   Generic Ratio Macro       |
+| <b>Generic Ratio Macro</b> ::= Macro Def ID, Generic Ratio?              |
+| <b>Generic Ratio</b> ::= Ratio   Evaluated Ratio                         |
+
+**Table 45/T.171 – Overview of Generic value useful definitions (concluded)**
+
+|                                      |                                                 |
+|--------------------------------------|-------------------------------------------------|
+| <b>Ratio</b> ::=                     | Numerator, Denominator?                         |
+| <b>Numerator</b> ::=                 | Integer                                         |
+| <b>Denominator</b> ::=               | Integer                                         |
+| <b>Generic String Param</b> ::=      | Generic String   Generic String Macro           |
+| <b>Generic String Macro</b> ::=      | Macro Def ID, Generic String?                   |
+| <b>Generic String</b> ::=            | String   Evaluated String                       |
+| <b>String</b> ::=                    | <i>\$GraphicString</i>                          |
+| <b>Generic Reference Param</b> ::=   | Generic Reference   Generic Reference Macro     |
+| <b>Generic Reference Macro</b> ::=   | Macro Def ID, Generic Reference?                |
+| <b>Generic Reference</b> ::=         | Reference   Evaluated Reference                 |
+| <b>Generic List Param</b> ::=        | Generic List   Generic List Macro               |
+| <b>Generic List Macro</b> ::=        | Macro Def ID, Generic List?                     |
+| <b>Generic List</b> ::=              | List   Evaluated List                           |
+| <b>List</b> ::=                      | Value*                                          |
+| <b>Generic List Elt ID Param</b> ::= | Generic List Elt ID   Generic List Elt ID Macro |
+| <b>Generic List Elt ID Macro</b> ::= | Macro Def ID, Generic List Elt ID?              |
+| <b>Generic List Elt ID</b> ::=       | Tail                                            |
+
+#### 73.5.1 Generic Value Param
+
+- Parameter of Generic Value.
+- Choice between (Generic Value, Generic Value Macro).
+
+#### 73.5.2 Generic Value Macro
+
+- Allows the specification of a macro parameter instead of a specified Generic Value value.
+- Sequence of (Macro Def ID, Generic Value?).
+
+#### 73.5.3 Generic Value
+
+- Provides a mechanism to specify values in a generic way. The generic values are typically used to express elementary action parameters, conditions or MHEG object attribute.
+- Choice between (Value, Evaluated Value).
+
+#### 73.5.4 Value
+
+- Specifications of all possible values supported by this Recommendation.
+- Choice between (Boolean, Numeric, Ratio, String, List, Reference).
+
+#### 73.5.5 Generic Boolean Param
+
+- Parameter of Generic Boolean.
+- Choice between (Generic Boolean, Generic Boolean Macro).
+
+#### 73.5.6 Generic Boolean Macro
+
+- Allows the specification of a macro parameter instead of a specified Generic Boolean value.
+- Sequence of (Macro Def ID, Generic Boolean?).
+
+#### **73.5.7 Generic Boolean**
+
+- A generic boolean shall have one of the following values: true, false, a result of a get action.
+- Choice between (Boolean, Evaluated Boolean).
+
+#### **73.5.8 Boolean**
+
+- A boolean is encoded in this Recommendation as an ASN.1 BOOLEAN.
+- BOOLEAN.
+
+#### **73.5.9 Generic Numeric Param**
+
+- Parameter of Generic Numeric.
+- Choice between (Generic Numeric, Generic Numeric Macro).
+
+#### **73.5.10 Generic Numeric Macro**
+
+- Allows the specification of a macro parameter instead of a specified Generic Numeric value.
+- Sequence of (Macro Def ID, Generic Numeric?).
+
+#### **73.5.11 Generic Numeric**
+
+- A generic numeric has one of the following values: a numeric, a result of a get action.
+- Choice between (Numeric, Evaluated Numeric).
+
+#### **73.5.12 Numeric**
+
+- The design of this Recommendation does not limit the numerical values in any way. The values may be integers, reals or complex. However the coded representations may impose limitations. The ASN.1 syntax defined in this Recommendation encodes numeric as an ASN.1 INTEGER, and it is recommended that authors assume this limitation.
+- INTEGER.
+
+#### **73.5.13 Generic Integer Param**
+
+- Parameter of Generic Integer.
+- Choice between (Generic Integer, Generic Integer Macro).
+
+#### **73.5.14 Generic Integer Macro**
+
+- Allows the specification of a macro parameter instead of a specified Generic Integer value.
+- Sequence of (Macro Def ID, Generic Integer?).
+
+#### **73.5.15 Generic Integer**
+
+- A generic integer has one of the following values: an integer, a result of a get action.
+- Choice between (Integer, Evaluated Integer).
+
+#### **73.5.16 Integer**
+
+- An integer is encoded in this Recommendation as an ASN.1 INTEGER.
+- INTEGER.
+
+#### **73.5.17 Generic Ratio Param**
+
+- Parameter of Generic Ratio.
+- Choice between (Generic Ratio, Generic Ratio Macro).
+
+#### **73.5.18 Generic Ratio Macro**
+
+- Allows the specification of a macro parameter instead of a specified Generic Ratio value.
+- Sequence of (Macro Def ID, Generic Ratio?).
+
+#### **73.5.19 Generic Ratio**
+
+- A generic ratio has one of the following values: a ratio, a result of a get action.
+- Choice between (Ratio, Evaluated Ratio).
+
+#### **73.5.20 Ratio**
+
+- A ratio value is a pair of integers (m, n) with m the numerator and n the denominator of a fraction. If the denominator is omitted, it is assumed to be 100, thus interpreting the numerator as a percentage.  
+The numerator shall be greater than 1 and the denominator may be negative.
+- Sequence of (Numerator, Denominator?).
+
+#### **73.5.21 Numerator**
+
+- Numerator of a fraction.
+- Integer.
+
+#### **73.5.22 Denominator**
+
+- Denominator of a fraction.
+- Integer.
+
+#### **73.5.23 Generic String Param**
+
+- Parameter of Generic String.
+- Choice between (Generic String, Generic String Macro).
+
+#### **73.5.24 Generic String Macro**
+
+- Allows the specification of a macro parameter instead of a specified Generic String value.
+- Sequence of (Macro Def ID, Generic String?).
+
+#### **73.5.25 Generic String**
+
+- A generic string has one of the following values: a string, a result of a get action.
+- Choice between (String, Evaluated String).
+
+#### **73.5.26 String**
+
+- A string is encoded in this Recommendation as an ASN.1 Graphic String. This allows for international string specification.
+- GraphicString.
+
+#### **73.5.27 Generic Reference Param**
+
+- Parameter of Generic Reference.
+- Choice between (Generic Reference, Generic Reference Macro).
+
+#### **73.5.28 Generic Reference Macro**
+
+- Allows the specification of a macro parameter instead of a specified Generic Reference value.
+- Sequence of (Macro Def ID, Generic Reference?).
+
+#### **73.5.29 Generic Reference**
+
+- A generic reference has one of the following values: a reference, a result of a get action.
+- Choice between (Reference, Evaluated Reference).
+
+#### **73.5.30 Generic List Param**
+
+- Parameter of Generic List.
+- Choice between (Generic List, Generic List Macro).
+
+### 73.5.31 Generic List Macro
+
+- Allows the specification of a macro parameter instead of a specified Generic List value.
+- Sequence of (Macro Def ID, Generic List?).
+
+### 73.5.32 Generic List
+
+- A generic list has one of the following values: a list, a result of a get action.
+- Choice between (List, Evaluated List).
+
+### 73.5.33 List
+
+- A list of values.
+- List of (Value).
+
+### 73.5.34 Generic List Elt ID Param
+
+- Parameter of Generic List Elt ID.
+- Choice between (Generic List Elt ID, Generic List Elt ID Macro).
+
+### 73.5.35 Generic List Elt ID Macro
+
+- Allows the specification of a macro parameter instead of a specified Generic List Elt ID value.
+- Sequence of (Macro Def ID, Generic List Elt ID?).
+
+### 73.5.36 Generic List Elt ID
+
+- Identification of a generic value which is an element of a generic list.
+- Tail.
+
+## 73.6 Evaluated values useful definitions
+
+**Table 46/T.171 – Overview of Evaluated values useful definitions**
+
+|                                                                                               |
+|-----------------------------------------------------------------------------------------------|
+| <b>Get Event Data</b> ::= Rt-Component Channel Tg Param                                       |
+| <b>Get Event</b> ::= Rt-Component Channel Tg Param                                            |
+| <b>Get Channel Perceptability</b> ::= Channel Target Param                                    |
+| <b>Get Channel Availability Status</b> ::= Channel Target Param                               |
+| <b>Get Style</b> ::= Rt-Component Target Param                                                |
+| <b>Get Number Of Interacted Sockets</b> ::= Rt-Composite Target Param, Interaction Type Param |
+| <b>Get Interaction Status</b> ::= Rt-Component Target Param, Interaction Type Param           |
+| <b>Get Max Interact Required</b> ::= Rt-Component Target Param, Interaction Type Param        |
+| <b>Get Min Interact Required</b> ::= Rt-Component Target Param, Interaction Type Param        |
+| <b>Get Interaction Ability</b> ::= Rt-Component Target Param, Interaction Type Param          |
+| <b>Get Stream Chosen State</b> ::= Rt-Mux Target Param, Stream Identification Param           |
+| <b>Get Stream Choice</b> ::= Rt-Mux Target Param                                              |
+| <b>Get GVF</b> ::= Rt-Composite Target Param   Channel Target Param                           |
+| <b>Get PCV</b> ::= Rt-Content Target Param                                                    |
+| <b>Get CV</b> ::= Rt-Content Target Param                                                     |
+| <b>Get OV</b> ::= Rt-Content Target Param                                                     |
+
+**Table 46/T.171 – Overview of Evaluated values useful definitions (cont.)**
+
+|                                   |                                                                             |
+|-----------------------------------|-----------------------------------------------------------------------------|
+| <b>Get User Spatial Control</b>   | ::= Rt-Component Target Param, Spatial Control Param                        |
+| <b>Get GSF</b>                    | ::= Rt-Component Target Param, Expected Axis Result Param                   |
+| <b>Get PVS Position</b>           | ::= Rt-Component Target Param, Point Type Param, Expected Axis Result Param |
+| <b>Get PAP</b>                    | ::= Rt-Component Target Param, Point Type Param, Expected Axis Result Param |
+| <b>Get PVS</b>                    | ::= Rt-Component Target Param, Point Type Param, Expected Axis Result Param |
+| <b>Get OVS Position</b>           | ::= Rt-Component Target Param, Point Type Param, Expected Axis Result Param |
+| <b>Get OAP</b>                    | ::= Rt-Component Target Param, Point Type Param, Expected Axis Result Param |
+| <b>Get OVS</b>                    | ::= Rt-Component Target Param, Point Type Param, Expected Axis Result Param |
+| <b>Get OVS Proj Strategy</b>      | ::= Rt-Component Target Param                                               |
+| <b>Get Resizing Strategy</b>      | ::= Rt-Composite Target Param                                               |
+| <b>Get Aspect Ratio</b>           | ::= Rt-Component Target Param                                               |
+| <b>Get POS</b>                    | ::= Rt-Component Target Param, Expected Axis Result Param                   |
+| <b>Get OS</b>                     | ::= Rt-Component Target Param, Expected Axis Result Param                   |
+| <b>Get Timestone Status</b>       | ::= Rt-Component Target Param                                               |
+| <b>Get GTF</b>                    | ::= Rt-Component Target Param                                               |
+| <b>Get PVD Position</b>           | ::= Rt-Component Target Param                                               |
+| <b>Get Temporal Termination</b>   | ::= Rt-Component Target Param                                               |
+| <b>Get CTP</b>                    | ::= Rt-Component Target Param                                               |
+| <b>Get PVD</b>                    | ::= Rt-Component Target Param, Expected PVD Result Param                    |
+| <b>Get OVD</b>                    | ::= Rt-Component Target Param, Expected OVD Result Param                    |
+| <b>Get POD</b>                    | ::= Rt-Component Target Param                                               |
+| <b>Get OD</b>                     | ::= Rt-Component Target Param                                               |
+| <b>Get Presentation Priority</b>  | ::= Rt-Component Target Param                                               |
+| <b>Get Perceptability</b>         | ::= Rt-Component Target Param                                               |
+| <b>Get RPS Assignment</b>         | ::= Rt-Component Target Param                                               |
+| <b>Get Rt-Composite Address</b>   | ::= Rt-Composite Target Param, Navigation Command Param                     |
+| <b>Get Termination Status</b>     | ::= Rt-Script Target Param                                                  |
+| <b>Get Running Status</b>         | ::= Rt-Target Param                                                         |
+| <b>Get Rt-Availability Status</b> | ::= Rt-Target Param                                                         |
+| <b>Get Data</b>                   | ::= Content Target Param, Generic List Elt ID Param?                        |
+| <b>Get Activation Status</b>      | ::= Link Target Param                                                       |
+| <b>Get Preparation Status</b>     | ::= Mh-Target Param                                                         |
+| <b>Get Catalogued Attribute</b>   | ::= Target Param, Cat Ext Attribute Param                                   |
+| <b>Get Boolean</b>                | ::= <i>\$NULL</i>                                                           |
+| <b>Get Numeric</b>                | ::= Get Integer                                                             |
+
+**Table 46/T.171 – Overview of Evaluated values useful definitions (concluded)**
+
+|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
+|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| <p><b>Get Integer</b> ::= <br/> Get Preparation Status   Get Activation Status   Get Rt-Availability Status   Get Running Status   Get Termination Status   Get Presentation Priority   Get OD   Get POD   Get PVD   Get CTP   Get Temporal Termination   Get PVD Position   Get Timestone Status   Get Aspect Ratio   Get Resizing Strategy   Get OVS Proj Strategy   Get User Spatial Control   Get CV   Get PCV   Get Stream Chosen State   Get Min Interact Required   Get Max Interact Required   Get Number Of Interacted Sockets   Get Channel Availability Status   Get Channel Perceptability</p> <p><b>Get Ratio</b> ::= Get Perceptability</p> <p><b>Get String</b> ::= \$NULL</p> <p><b>Get Reference</b> ::= Get Rt-Composite Address   Get RPS Assignment</p> <p><b>Get List</b> ::= Get Catalogued Attribute   Get Stream Choice   Get Style   Get Event</p> <p><b>Get Any</b> ::= <br/> Get Data   Get OVD   Get GTF   Get OS   Get POS   Get OVS   Get OAP   Get OVS Position   Get PVS   Get PAP   Get PVS Position   Get GSF   Get GVF   Get Interaction Ability   Get Interaction Status   Get Event Data</p> <p><b>Evaluated Value</b> ::= <br/> Get Boolean   Get Numeric   Get Ratio   Get String   Get Reference   Get List   Get Any   Extensibility Provision</p> <p><b>Evaluated Boolean</b> ::= Get Boolean   Get Any</p> <p><b>Evaluated Numeric</b> ::= Get Numeric   Get Integer   Get Any</p> <p><b>Evaluated Integer</b> ::= Get Integer   Get Any</p> <p><b>Evaluated Ratio</b> ::= Get Ratio   Get Any</p> <p><b>Evaluated String</b> ::= Get String   Get Any</p> <p><b>Evaluated Reference</b> ::= Get Reference   Get Any</p> <p><b>Evaluated List</b> ::= Get List   Get Any</p> |
+|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+
+### 73.6.1 Get Event Data
+
+- Retrieves the event data of the target.
+- Rt-Component Channel Tg Param.
+
+### 73.6.2 Get Event
+
+- Retrieves the event of the target.
+- Rt-Component Channel Tg Param.
+
+### 73.6.3 Get Channel Perceptability
+
+- Retrieves the channel perceptability of the target.
+- Channel Target Param.
+
+### 73.6.4 Get Channel Availability Status
+
+- Retrieves the channel availability status.
+- Channel Target Param.
+
+### 73.6.5 Get Style
+
+- Retrieves the current style associated with the target.
+- Rt-Component Target Param.
+
+### 73.6.6 Get Number of Interacted Sockets
+
+- Retrieves the number of interacted sockets attribute value of the target.
+- Sequence of (Rt-Composite Target Param, Interaction Type Param).
+
+#### **73.6.7 Get Interaction Status**
+
+- Retrieves the interaction status value of the target. This action evaluates “selected” or “not selected” for the selection, and “modified”, “modifying” or “not modified” for the modification.
+- Sequence of (Rt-Component Target Param, Interaction Type Param).
+
+#### **73.6.8 Get Max Interact Required**
+
+- Retrieves the max interact required attribute value of the target.
+- Sequence of (Rt-Component Target Param, Interaction Type Param).
+
+#### **73.6.9 Get Min Interact Required**
+
+- Retrieves the min interact required attribute value of the target.
+- Sequence of (Rt-Component Target Param, Interaction Type Param).
+
+#### **73.6.10 Get Interaction Ability**
+
+- Retrieves the interaction ability of the target.
+- Sequence of (Rt-Component Target Param, Interaction Type Param).
+
+#### **73.6.11 Get Stream Chosen State**
+
+- Retrieves the stream state.
+- Sequence of (Rt-Mux Target Param, Stream Identification Param).
+
+#### **73.6.12 Get Stream Choice**
+
+- Retrieves a list of stream IDs chosen for the target.
+- Rt-Mux Target Param.
+
+#### **73.6.13 Get GVF**
+
+- Retrieves the GVF.
+- Choice between (Rt-Composite Target Param, Channel Target Param).
+
+#### **73.6.14 Get PCV**
+
+- Retrieves the PCV.
+- Rt-Content Target Param.
+
+#### **73.6.15 Get CV**
+
+- Retrieves the CV.
+- Rt-Content Target Param.
+
+#### **73.6.16 Get OV**
+
+- Retrieves the OV.
+- Rt-Content Target Param.
+
+#### **73.6.17 Get User Spatial Control**
+
+- Retrieves the user spatial control attribute value.
+- Sequence of (Rt-Component Target Param, Spatial Control Param).
+
+#### **73.6.18 Get GSF**
+
+- Retrieves the GSF.
+- Sequence of (Rt-Component Target Param, Expected Axis Result Param).
+
+#### **73.6.19 Get PVS Position**
+
+- Retrieves the PVS position.
+- Sequence of (Rt-Component Target Param, Point Type Param, Expected Axis Result Param).
+
+#### **73.6.20 Get PAP**
+
+- Retrieves the PAP.
+- Sequence of (Rt-Component Target Param, Point Type Param, Expected Axis Result Param).
+
+#### **73.6.21 Get PVS**
+
+- Retrieves the PVS.
+- Sequence of (Rt-Component Target Param, Point Type Param, Expected Axis Result Param).
+
+#### **73.6.22 Get OVS Position**
+
+- Retrieves the OVS position.
+- Sequence of (Rt-Component Target Param, Point Type Param, Expected Axis Result Param).
+
+#### **73.6.23 Get OAP**
+
+- Retrieves the OAP.
+- Sequence of (Rt-Component Target Param, Point Type Param, Expected Axis Result Param).
+
+#### **73.6.24 Get OVS**
+
+- Retrieves the OVS.
+- Sequence of (Rt-Component Target Param, Point Type Param, Expected Axis Result Param).
+
+#### **73.6.25 Get OVS Proj Strategy**
+
+- Retrieves the OVS Proj Strategy attribute.
+- Rt-Component Target Param.
+
+#### **73.6.26 Get Resizing Strategy**
+
+- Retrieves the resizing strategy attribute.
+- Rt-Composite Target Param.
+
+#### **73.6.27 Get Aspect Ratio**
+
+- Retrieves the aspect ratio attribute.
+- Rt-Component Target Param.
+
+#### **73.6.28 Get POS**
+
+- Retrieves the POS.
+- Sequence of (Rt-Component Target Param, Expected Axis Result Param).
+
+#### **73.6.29 Get OS**
+
+- Retrieves the OS.
+- Sequence of (Rt-Component Target Param, Expected Axis Result Param).
+
+#### **73.6.30 Get Timestone Status**
+
+- Retrieves the timestone status value.
+- Rt-Component Target Param.
+
+#### **73.6.31 Get GTF**
+
+- Retrieves the GTF of the target.
+- Rt-Component Target Param.
+
+**73.6.32 Get PVD Position**
+
+- Retrieves the PVD position attached to its PRPS.
+- Rt-Component Target Param.
+
+**73.6.33 Get Temporal Termination**
+
+- Offers to retrieve the temporal termination of the target.
+- Rt-Component Target Param.
+
+**73.6.34 Get CTP**
+
+- Offers to retrieve the CTP of the target.
+- Rt-Component Target Param.
+
+**73.6.35 Get PVD**
+
+- Retrieves the PVD, initial temporal position or terminal temporal position of the target.
+- Sequence of (Rt-Component Target Param, Expected PVD Result Param).
+
+**73.6.36 Get OVD**
+
+- Retrieve the OVD, initial temporal position or terminal temporal position of the target.
+- Sequence of (Rt-Component Target Param, Expected OVD Result Param).
+
+**73.6.37 Get POD**
+
+- Retrieves the POD of the target.
+- Rt-Component Target Param.
+
+**73.6.38 Get OD**
+
+- Retrieves the OD of the target.
+- Rt-Component Target Param.
+
+**73.6.39 Get Presentation Priority**
+
+- Retrieves the presentation priority.
+- Rt-Component Target Param.
+
+**73.6.40 Get Perceptability**
+
+- Retrieves the perceptability.
+- Rt-Component Target Param.
+
+**73.6.41 Get RPS Assignment**
+
+- Retrieves the RPS assignment to an rt-component and a root rt-component.
+- Rt-Component Target Param.
+
+**73.6.42 Get Rt-Composite Address**
+
+- Offers means to rise to the root, to descend to leave and to explore the intermediate levels (nodes) in a composition tree.
+- Sequence of (Rt-Composite Target Param, Navigation Command Param).
+
+**73.6.43 Get Termination Status**
+
+- Retrieves the termination status of an rt-script. The result is “terminated” or “not terminated”.
+- Rt-Script Target Param.
+
+**73.6.44 Get Running Status**
+
+- Retrieves the running status of an rt-object or a socket. The result is “running” or “not running”.
+- Rt-Target Param.
+
+#### **73.6.45 Get Rt-Availability Status**
+
+- Provides means to retrieve the availability status of an rt-object. The result is “available” or “not available”.
+- Rt-Target Param.
+
+#### **73.6.46 Get Data**
+
+- This action retrieves a generic value or an element of a generic list stored in a content object.
+- Sequence of (Content Target Param, Generic List Elt ID Param?).
+
+#### **73.6.47 Get Activation Status**
+
+- This action retrieves the activation status value of a link object.
+- Link Target Param.
+
+#### **73.6.48 Get Preparation Status**
+
+- Retrieves the preparation status of an MHEG object. The result is “ready” or “not ready”.
+- MH-Target Param.
+
+#### **73.6.49 Get Catalogued Attribute**
+
+- Retrieves the value of an extended catalogued attribute. The result is a generic value which is described in the corresponding catalogue.
+- Sequence of (Target Param, Cat Ext Attribute Param).
+
+#### **73.6.50 Get Boolean**
+
+- A get boolean is one of the result of a get action that returns a boolean.
+- NULL.
+
+#### **73.6.51 Get Numeric**
+
+- A get numeric is one of the result of a get action that returns a numeric.
+- Get Integer.
+
+#### **73.6.52 Get Integer**
+
+- A get integer is one of the result of a get action that returns an integer.
+- Choice between (Get Preparation Status, Get Activation Status, Get Rt-Availability Status, Get Running Status, Get Termination Status, Get Presentation Priority, Get OD, Get POD, Get PVD, Get CTP, Get Temporal Termination, Get PVD Position, Get Timestone Status, Get Aspect Ratio, Get Resizing Strategy, Get OVS Proj Strategy, Get User Spatial Control, Get CV, Get PCV, Get Stream Chosen State, Get Min Interact Required, Get Max Interact Required, Get Number of Interacted Sockets, Get Channel Availability Status, Get Channel Perceptability).
+
+#### **73.6.53 Get Ratio**
+
+- A get ratio is one of the result of a get action that returns a ratio.
+- Get Perceptability.
+
+#### **73.6.54 Get String**
+
+- A get string is one of the result of a get action that returns a string.
+- NULL.
+
+#### **73.6.55 Get Reference**
+
+- A get reference is one of the result of a get action that returns a reference.
+- Choice between (Get Rt-Composite Address, Get RPS Assignment).
+
+#### **73.6.56 Get List**
+
+- A get list is one of the result of a get action that returns a list.
+- Choice between (Get Catalogued Attribute, Get Stream Choice, Get Style, Get Event).
+
+#### **73.6.57 Get Any**
+
+- A get any is one of the result of a get action that returns any kind of value.
+- Choice between (Get Data, Get OVD, Get GTF, Get OS, Get POS, Get OVS, Get OAP, Get OVS Position, Get PVS, Get PAP, Get PVS Position, Get GSF, Get GVF, Get Interaction Ability, Get Interaction Status, Get Event Data).
+
+#### **73.6.58 Evaluated Value**
+
+- An evaluated value is one of the result of a get action.
+- Choice between (Get Boolean, Get Numeric, Get Ratio, Get String, Get Reference, Get List, Get Any, Extensibility Provision).
+
+#### **73.6.59 Evaluated Boolean**
+
+- An evaluated boolean is one of the result of a get action resulting to a boolean or any.
+- Choice between (Get Boolean, Get Any).
+
+#### **73.6.60 Evaluated Numeric**
+
+- An evaluated numeric is one of the result of a get action resulting to a numeric, an integer or any.
+- Choice between (Get Numeric, Get Integer, Get Any).
+
+#### **73.6.61 Evaluated Integer**
+
+- An evaluated integer is one of the result of a get action resulting to an integer or any.
+- Choice between (Get Integer, Get Any).
+
+#### **73.6.62 Evaluated Ratio**
+
+- An evaluated ratio is one of the result of a get action resulting to a ratio or any.
+- Choice between (Get Ratio, Get Any).
+
+#### **73.6.63 Evaluated String**
+
+- An evaluated string is one of the result of a get action resulting to a string or any.
+- Choice between (Get String, Get Any).
+
+#### **73.6.64 Evaluated Reference**
+
+- An evaluated reference is one of the result of a get action resulting to a reference or any.
+- Choice between (Get Reference, Get Any).
+
+#### **73.6.65 Evaluated List**
+
+- An evaluated list is one of the result of a get action resulting to a list or any.
+- Choice between (Get List, Get Any).
+
+## 73.7 Hooks
+
+Table 47/T.171 – Overview of Hooks
+
+Content Hook ::= Catalogued Content Encoding?, Content Encoding Description?
+
+Content Encoding Description ::= *\$OCTET STRING*
+
+Script Hook ::= Catalogued Script Encoding?, Script Encoding Description?
+
+Script Encoding Description ::= *\$OCTET STRING*
+
+### 73.7.1 Content Hook
+
+- Encoding and decoding information enabling the use of the encoded media or non-media data. This information contains an identification field for the media encoding standard and a field for parameters associated with the encoding.  
+The semantics of these fields are not defined by MHEG but will be under control of MHEG Format Identifier Registration Authority.
+- Sequence of (Catalogued Content Encoding?, Content Encoding Description?).
+
+### 73.7.2 Content Encoding Description
+
+- Additional information associated with reference to specific encoding/decoding techniques. The semantics of this description can be provided in the content encoding catalogue.
+- OCTET STRING.
+
+### 73.7.3 Script Hook
+
+- Encoding and decoding information enabling the use of the encoded scripting language. This information contains an identification field for the script encoding standard and a field for parameters associated with the encoding MHEG Format Identifier Registration Authority.
+- Sequence of (Catalogued Script Encoding?, Script Encoding Description?).
+
+### 73.7.4 Script Encoding Description
+
+- Additional information associated with reference to specific encoding/decoding techniques. The semantics of this description can be provided in the script encoding catalogue.
+- OCTET STRING.
+
+## 73.8 Extensibility
+
+Table 48/T.171 – Overview of Extensibility
+
+Catalogued Content Encoding ::= Registered Content Encoding | Proprietary Content Encoding
+
+Registered Content Encoding ::= *#Imported from ITU-T Rec. T.171 cat*
+
+Proprietary Content Encoding ::= Prop Cat Entry ID
+
+Catalogued Script Encoding ::= Registered Script Encoding | Proprietary Script Encoding
+
+Registered Script Encoding ::= *#Imported from ITU-T Rec. T.171 cat*
+
+Proprietary Script Encoding ::= Prop Cat Entry ID
+
+Cat Content Classification ::= Registered Content Classification | Prop Content Classification
+
+Registered Content Classification ::= *#Imported from ITU-T Rec. T.171 cat*
+
+**Table 48/T.171 – Overview of Extensibility (concluded)**
+
+|                                            |                                                                                       |
+|--------------------------------------------|---------------------------------------------------------------------------------------|
+| Prop Content Classification ::=            | <b>Prop Cat Entry ID</b>                                                              |
+| Catalogued Script Classification ::=       | <b>Registered Script Classification   Prop Script Classification</b>                  |
+| Registered Script Classification ::=       | <i>#Imported from ITU-T Rec. T.171 cat</i>                                            |
+| Prop Script Classification ::=             | <b>Prop Cat Entry ID</b>                                                              |
+| Catalogued Media Type ::=                  | <b>Registered Media Type   Proprietary Media Type</b>                                 |
+| Registered Media Type ::=                  | <i>#Imported from ITU-T Rec. T.171 cat</i>                                            |
+| Proprietary Media Type ::=                 | <b>Prop Cat Entry ID</b>                                                              |
+| Catalogued Style ::=                       | <b>Registered Style   Proprietary Style</b>                                           |
+| Registered Style ::=                       | <i>#Imported from ITU-T Rec. T.171 cat</i>                                            |
+| Proprietary Style ::=                      | <b>Prop Cat Entry ID</b>                                                              |
+| Catalogued Event ::=                       | <b>Registered Event   Proprietary Event</b>                                           |
+| Registered Event ::=                       | <i>#Imported from ITU-T Rec. T.171 cat</i>                                            |
+| Proprietary Event ::=                      | <b>Prop Cat Entry ID</b>                                                              |
+| Catalogued Extended EA ::=                 | <b>Registered Extended Elementary Action   Proprietary Extended Elementary Action</b> |
+| Registered Extended Elementary Action ::=  | <i>#Imported from ITU-T Rec. T.171 cat</i>                                            |
+| Proprietary Extended Elementary Action ::= | <b>Prop Cat Entry ID</b>                                                              |
+| Cat Ext Attribute ::=                      | <b>Registered Extended Attribute   Proprietary Extended Attribute</b>                 |
+| Registered Extended Attribute ::=          | <i>#Imported from ITU-T Rec. T.171 cat</i>                                            |
+| Proprietary Extended Attribute ::=         | <b>Prop Cat Entry ID</b>                                                              |
+| Prop Cat Entry ID ::=                      | <b>Tail   \$OCTET STRING</b>                                                          |
+| Extensibility Provision ::                 | <b>= Pointpointpoint</b>                                                              |
+| Pointpointpoint ::                         | <b>= #INTEGER ::= 9999</b>                                                            |
+
+#### **73.8.1 Catalogued Content Encoding**
+
+- Identification of the encoding of the content data. Two types of catalogues are offered: a registered catalogue and a proprietary catalogue.
+- Choice between (Registered Content Encoding, Proprietary Content Encoding).
+
+#### **73.8.2 Registered Content Encoding**
+
+- Identification of the encoding and decoding techniques within a registered content catalogue.  
+The registered content catalogue is under control of MHEG Format Identifier Registration Authority as specified by ISO/IEC 13522-4.
+- Imported from ISO/IEC 13522-4 cat module.
+
+#### **73.8.3 Proprietary Content Encoding**
+
+- Identification of the encoding and decoding techniques within a proprietary content catalogue.  
+The using application is responsible for the resolution of references to proprietary content catalogue.
+- Prop Cat Entry ID.
+
+#### **73.8.4 Catalogued Script Encoding**
+
+- Identification of the encoding of the scripting language. Two types of catalogues are offered: a registered catalogue and a proprietary catalogue.
+- Choice between (Registered Script Encoding, Proprietary Script Encoding).
+
+#### **73.8.5 Registered Script Encoding**
+
+- Identification of the scripting language within a registered script catalogue.  
+The registered script catalogue is under control of the MHEG Format Identifier Registration Authority as specified by ISO/IEC 13522-4.
+- Imported from ISO/IEC 13522-4 cat module.
+
+#### **73.8.6 Proprietary Script Encoding**
+
+- Identification of the scripting language within a proprietary script catalogue.
+- Prop Cat Entry ID.
+
+#### **73.8.7 Cat Content Classification**
+
+- Identification of data type. For media data, the content classification is used to indicate the perception media, e.g. text, graphics, audio. This information may be used by a negotiation process, a database, or by an MHEG engine to choose a decoder. It is provided as an optional assistance in determining the type of the data. In case of incompatibility between the hook and the classification information, the hook is to be preferred.
+- Choice between (Registered Content Classification, Prop Content Classification).
+
+#### **73.8.8 Registered Content Classification**
+
+- Identification of the type of classification within the registered content catalogue.  
+The Mheg Content classification is under control of the MHEG Format Identifier Registration Authority as specified by ISO/IEC 13522-4.
+- Imported from ISO/IEC 13522-4 cat module.
+
+#### **73.8.9 Prop Content Classification**
+
+- Identification of the data type within the proprietary content catalogue.
+- Prop Cat Entry ID.
+
+#### **73.8.10 Catalogued Script Classification**
+
+- Identification of script type.
+- Choice between (Registered Script Classification, Prop Script Classification).
+
+#### **73.8.11 Registered Script Classification**
+
+- Identification of the type of classification within the registered script catalogue.  
+The registered script classification is under control of the MHEG Format Identifier Registration Authority as specified by ISO/IEC 13522-4.
+- Imported from ISO/IEC 13522-4 cat module.
+
+#### **73.8.12 Prop Script Classification**
+
+- Identification of the script type within the proprietary script classification catalogue.
+- Prop Cat Entry ID.
+
+#### **73.8.13 Catalogued Media Type**
+
+- Identification of media type.
+- Choice between (Registered Media Type, Proprietary Media Type).
+
+#### **73.8.14 Registered Media Type**
+
+- Identification of the type of classification within the registered media type catalogue.  
+The registered media type classification is under control of the MHEG Format Identifier Registration Authority as specified by ISO/IEC 13522-4.
+- Imported from ISO/IEC 13522-4 cat module.
+
+#### **73.8.15 Proprietary Media Type**
+
+- Identification of the media type within the proprietary media type classification catalogue.
+- Prop Cat Entry ID.
+
+#### **73.8.16 Catalogued Style**
+
+- Identification of style.
+- Choice between (Registered Style, Proprietary Style).
+
+#### **73.8.17 Registered Style**
+
+- Identification of the type of classification within the registered style catalogue.  
+The registered style classification is under control of the MHEG Format Identifier Registration Authority as specified by ISO/IEC 13522-4.
+- Imported from ISO/IEC 13522-4 cat module.
+
+#### **73.8.18 Proprietary Style**
+
+- Identification of the style type within the proprietary style classification catalogue.
+- Prop Cat Entry ID.
+
+#### **73.8.19 Catalogued Event**
+
+- Identification of event.
+- Choice between (Registered Event, Proprietary Event).
+
+#### **73.8.20 Registered Event**
+
+- Identification of the type of classification within the registered event catalogue.  
+The registered event classification is under control of the MHEG Format Identifier Registration Authority as specified by ISO/IEC 13522-4.
+- Imported from ISO/IEC 13522-4 cat module.
+
+#### **73.8.21 Proprietary Event**
+
+- Identification of the event type within the proprietary event classification catalogue.
+- Prop Cat Entry ID.
+
+#### **73.8.22 Catalogued Extended EA**
+
+- Identification of catalogued extended elementary action. Either registered one or proprietary one may be used.
+- Choice between (Registered Extended Elementary Action, Proprietary Extended Elementary Action).
+
+#### **73.8.23 Registered Extended Elementary Action**
+
+- Identification of the type of classification within the registered catalogued elementary action catalogue.  
+The registered catalogued elementary action classification is under control of the MHEG Format Identifier Registration Authority as specified by ISO/IEC 13522-4.
+- Imported from ISO/IEC 13522-4 cat module.
+
+#### **73.8.24 Proprietary Extended Elementary Action**
+
+- Identification of the catalogued elementary action type within the proprietary catalogued elementary action classification catalogue.
+- Prop Cat Entry ID.
+
+#### **73.8.25 Cat Ext Attribute**
+
+- Identification of extended attribute.
+- Choice between (Registered Extended Attribute, Proprietary Extended Attribute).
+
+### 73.8.26 Registered Extended Attribute
+
+- Identification of the type of classification within the registered extended attribute catalogue.  
+The registered extended attribute classification is under control of the MHEG Format Identifier Registration Authority as specified by ISO/IEC 13522-4.
+- Imported from ISO/IEC 13522-4 cat module.
+
+### 73.8.27 Proprietary Extended Attribute
+
+- Identification of the extended attribute type within the proprietary extended attribute classification catalogue.
+- Prop Cat Entry ID.
+
+### 73.8.28 Prop Cat Entry ID
+
+- Identification of an entry in a catalogue hierarchy.
+- Choice between (Tail, OCTET STRING).
+
+### 73.8.29 Extensibility Provision
+
+- Means to provide an extensibility of the syntax for a using application.
+- Point point point.
+
+## 73.9 Presentation space useful definitions
+
+Table 49/T.171 – Overview of Presentation space useful definitions
+
+```
+OPS Initialisation ::= OD?, OS?
+min-AVR ::= #INTEGER ::= 0
+max-AVR ::= #INTEGER ::= 255
+GF Param ::= GF | GF Macro
+GF Macro ::= Macro Def ID, GF?
+GF ::= Generic Ratio | default-GF
+default-GF ::= #INTEGER ::= 1
+X GF ::= GF
+Y GF ::= GF
+Z GF ::= GF
+Length ::= Integer
+Point ::= Integer | #terminal
+Temporal Position ::= Point
+Size ::= X Spatial Length?, Y Spatial Length?, Z Spatial Length?
+X Spatial Length ::= Spatial Length
+Y Spatial Length ::= Spatial Length
+Z Spatial Length ::= Spatial Length
+Spatial Length ::= Length | default-spatial-length
+default-spatial-length ::= #INTEGER ::= 65536
+Size Spec Param ::= Size Spec | Size Spec Macro
+Size Spec Macro ::= Macro Def ID, Size Spec?
+Size Spec ::= Lengths Spec | Get List | Get Any
+```
+
+**Table 49/T.171 – Overview of Presentation space useful definitions (concluded)**
+
+|                                                                                                                                  |
+|----------------------------------------------------------------------------------------------------------------------------------|
+| Lengths Spec ::= X Length Spec?, Y Length Spec?, Z Length Spec?                                                                  |
+| X Length Spec ::= Length Spec                                                                                                    |
+| Y Length Spec ::= Length Spec                                                                                                    |
+| Z Length Spec ::= Length Spec                                                                                                    |
+| Length Spec Param ::= Length Spec   Length Spec Macro                                                                            |
+| Length Spec Macro ::= Macro Def ID, Length Spec?                                                                                 |
+| Length Spec ::= Length   Relative Length   Get Integer   Get Ratio   Get Any                                                     |
+| Relative Length ::= Ratio                                                                                                        |
+| Spatial Position ::= X Point?, Y Point?, Z Point?                                                                                |
+| X Point ::= Point                                                                                                                |
+| Y Point ::= Point                                                                                                                |
+| Z Point ::= Point                                                                                                                |
+| Spatial Position Spec Param ::= Spatial Position Spec   Spatial Position Spec Macro                                              |
+| Spatial Position Spec Macro ::= Macro Def ID, Spatial Position Spec?                                                             |
+| Spatial Position Spec ::= Points Spec   Get List   Get Any                                                                       |
+| Points Spec ::= X Point Spec?, Y Point Spec?, Z Point Spec?                                                                      |
+| X Point Spec ::= Point Spec                                                                                                      |
+| Y Point Spec ::= Point Spec                                                                                                      |
+| Z Point Spec ::= Point Spec                                                                                                      |
+| Point Spec Param ::= Point Spec   Point Spec Macro                                                                               |
+| Point Spec Macro ::= Macro Def ID, Point Spec?                                                                                   |
+| Point Spec ::= Point   Relative Point   Get Integer   Get Ratio   Get Any                                                        |
+| Current Point Spec Param ::= Current Point Spec   Current Point Spec Macro                                                       |
+| Current Point Spec Macro ::= Macro Def ID, Current Point Spec?                                                                   |
+| Current Point Spec ::= Point   Relative Point   Original Point Factor   Current Point Factor   Get Integer   Get Ratio   Get Any |
+| Relative Point ::= Ratio                                                                                                         |
+| Original Point Factor ::= Ratio                                                                                                  |
+| Current Point Factor ::= Ratio                                                                                                   |
+| Duration Spec ::= Length Spec                                                                                                    |
+| Initial Point Spec Param ::= Initial Point Spec   Initial Point Spec Macro                                                       |
+| Initial Point Spec Macro ::= Macro Def ID, Initial Point Spec?                                                                   |
+| Terminal Point Spec Param ::= Terminal Point Spec   Terminal Point Spec Macro                                                    |
+| Terminal Point Spec Macro ::= Macro Def ID, Terminal Point Spec?                                                                 |
+| Initial Point Spec ::= Point Spec                                                                                                |
+| Terminal Point Spec ::= Point Spec                                                                                               |
+| Transition Duration Param ::= Generic Integer Param                                                                              |
+
+### **73.9.1 OPS Initialisation**
+
+- Provides the information to build an OPS of an rt-component or a channel. It provides an OD and an OS used to determine the OPS temporal and spatial axes lengths. The AVR is set to the range value provided by this Recommendation.
+- Sequence of (OD?, OS?).
+
+### **73.9.2 min-AVR**
+
+- Minimum AVR value provided by this Recommendation.
+- INTEGER ::= 0.
+
+### **73.9.3 max-AVR**
+
+- Maximum AVR value provided by this Recommendation.
+- INTEGER ::= 255.
+
+### **73.9.4 GF Param**
+
+- Parameter of GF.
+- Choice between (GF, GF Macro).
+
+### **73.9.5 GF Macro**
+
+- Allows the specification of a macro parameter instead of a specified GF value.
+- Sequence of (Macro Def ID, GF?).
+
+### **73.9.6 GF**
+
+- Specifies the GF of an rt-component or a channel.
+- Choice between (Generic Ratio, default-GF).
+
+### **73.9.7 default-GF**
+
+- Default GF value provided by this Recommendation.
+- INTEGER ::= 1.
+
+### **73.9.8 X GF**
+
+- Express the GF on the X axis.
+- GF.
+
+### **73.9.9 Y GF**
+
+- Express the GF on the Y axis.
+- GF.
+
+### **73.9.10 Z GF**
+
+- Express the GF on the Z axis.
+- GF.
+
+### **73.9.11 Length**
+
+- Specifies a length of an interval [Start Point, EndList Point]. It is equal to EndList-Point – Start-Point + 1.
+- Integer.
+
+### **73.9.12 Point**
+
+- Specifies a position within a duration or a size. It is expressed either in GTU or in GSU. The value 0 corresponds to the initial position of the corresponding duration or size. A reserved value “terminal” corresponds to the terminal position of the corresponding duration or size.
+- Choice between (Integer, terminal).
+
+### **73.9.13 Temporal Position**
+
+- Specifies a temporal position. It is expressed in GTU. The position is always specified within a duration.
+- Point.
+
+### **73.9.14 Size**
+
+- Specifies a size by providing the length on each axis: X, Y, Z.
+- Sequence of (X Spatial Length?, Y Spatial Length?, Z Spatial Length?).
+
+### **73.9.15 X Spatial Length**
+
+- Provides the length on X axis.
+- Spatial Length.
+
+### **73.9.16 Y Spatial Length**
+
+- Provides the length on Y axis.
+- Spatial Length.
+
+### **73.9.17 Z Spatial Length**
+
+- Provides the length on Z axis.
+- Spatial Length.
+
+### **73.9.18 Spatial Length**
+
+- Specifies the length of a spatial axis. It is expressed in GSU.
+- Choice between (Length, default-spatial-length).
+
+### **73.9.19 default-spatial-length**
+
+- Default spatial axis length value provided by this Recommendation.
+- INTEGER ::= 65536.
+
+### **73.9.20 Size Spec Param**
+
+- Parameter of Size Spec.
+- Choice between (Size Spec, Size Spec Macro).
+
+### **73.9.21 Size Spec Macro**
+
+- Allows the specification of a macro parameter instead of a specified Size Spec value.
+- Sequence of (Macro Def ID, Size Spec?).
+
+### **73.9.22 Size Spec**
+
+- This elementary action parameter specifies different means to define a size. It is expressed as a length on each axis: x, y, z.
+- Choice between (Lengths Spec, Get List, Get Any).
+
+### **73.9.23 Lengths Spec**
+
+- Expressed as a length on each axis: x, y, z.
+- Sequence of (X Length Spec?, Y Length Spec?, Z Length Spec?).
+
+### **73.9.24 X Length Spec**
+
+- Provides the length on X axis.
+- Length Spec.
+
+### **73.9.25 Y Length Spec**
+
+- Provides the length on Y axis.
+- Length Spec.
+
+#### **73.9.26 Z Length Spec**
+
+- Provides the length on Z axis.
+- Length Spec.
+
+#### **73.9.27 Length Spec Param**
+
+- Parameter of Length Spec.
+- Choice between (Length Spec, Length Spec Macro).
+
+#### **73.9.28 Length Spec Macro**
+
+- Allows the specification of a macro parameter instead of a specified Length Spec value.
+- Sequence of (Macro Def ID, Length Spec?).
+
+#### **73.9.29 Length Spec**
+
+- Each length may be specified as an absolute length, a relative length or as a result of a get integer, get ratio or get any actions.
+- Choice between (Length, Relative Length, Get Integer, Get Ratio, Get Any).
+
+#### **73.9.30 Relative Length**
+
+- Defines a length as a ratio of an interval.
+- Ratio.
+
+#### **73.9.31 Spatial Position**
+
+- Specifies a spatial position by providing a point on each axis: X, Y, Z.
+- Sequence of (X Point?, Y Point?, Z Point?).
+
+#### **73.9.32 X Point**
+
+- Provides the position on X axis.
+- Point.
+
+#### **73.9.33 Y Point**
+
+- Provides the position on Y axis.
+- Point.
+
+#### **73.9.34 Z Point**
+
+- Provides the position on Z axis.
+- Point.
+
+#### **73.9.35 Spatial Position Spec Param**
+
+- Parameter of Spatial Position Spec.
+- Choice between (Spatial Position Spec, Spatial Position Spec Macro).
+
+#### **73.9.36 Spatial Position Spec Macro**
+
+- Allows the specification of a macro parameter instead of a specified Spatial Position Spec value.
+- Sequence of (Macro Def ID, Spatial Position Spec?).
+
+#### **73.9.37 Spatial Position Spec**
+
+- This elementary action parameter specifies different means to define a spatial position. It is expressed as a length on each axis: x, y, z.
+- Choice between (Points Spec, Get List, Get Any).
+
+### **73.9.38 Points Spec**
+
+- Define a position. It is expressed as a length on each axis: x, y, z.
+- Sequence of (X Point Spec?, Y Point Spec?, Z Point Spec?).
+
+### **73.9.39 X Point Spec**
+
+- Length on X axis.
+- Point Spec.
+
+### **73.9.40 Y Point Spec**
+
+- Length on Y axis.
+- Point Spec.
+
+### **73.9.41 Z Point Spec**
+
+- Length on Z axis.
+- Point Spec.
+
+### **73.9.42 Point Spec Param**
+
+- Parameter of Point Spec.
+- Choice between (Point Spec, Point Spec Macro).
+
+### **73.9.43 Point Spec Macro**
+
+- Allows the specification of a macro parameter instead of a specified Point Spec value.
+- Sequence of (Macro Def ID, Point Spec?).
+
+### **73.9.44 Point Spec**
+
+- Each point may be specified as an absolute point, a relative point within a length or as a result of a get integer, get ratio or get any actions. An integer is interpreted as an absolute value. A ratio is interpreted as a relative value.
+- Choice between (Point, Relative Point, Get Integer, Get Ratio, Get Any).
+
+### **73.9.45 Current Point Spec Param**
+
+- Parameter of Current Point Spec.
+- Choice between (Current Point Spec, Current Point Spec Macro).
+
+### **73.9.46 Current Point Spec Macro**
+
+- Allows the specification of a macro parameter instead of a specified Current Point Spec value.
+- Sequence of (Macro Def ID, Current Point Spec?).
+
+### **73.9.47 Current Point Spec**
+
+- Each current point may be specified as an absolute point, a relative point within a length, a factor of the original point value, a factor of the current point value or as a result of a get integer, get ratio or get any actions. An integer is interpreted as an absolute value. A ratio is interpreted as a relative value.
+- Choice between (Point, Relative Point, Original Point Factor, Current Point Factor, Get Integer, Get Ratio, Get Any).
+
+#### **73.9.48 Relative Point**
+
+- Specified as a ratio to be mapped on an interval.
+- Ratio.
+
+#### **73.9.49 Original Point Factor**
+
+- Scaling Factor in relation to the original value of this point. It is defined as a positive ratio which is used as a multiplier of the original value of this point.
+- Ratio.
+
+#### **73.9.50 Current Point Factor**
+
+- Scaling Factor in relation to the current value of this point. It is defined as a positive ratio which is used as a multiplier of the current value of this point.
+- Ratio.
+
+#### **73.9.51 Duration Spec**
+
+- This elementary action parameter specifies different means to define a duration.
+- Length Spec.
+
+#### **73.9.52 Initial Point Spec Param**
+
+- Parameter of Initial Point Spec.
+- Choice between (Initial Point Spec, Initial Point Spec Macro).
+
+#### **73.9.53 Initial Point Spec Macro**
+
+- Allows the specification of a macro parameter instead of a specified Initial Point Spec value.
+- Sequence of (Macro Def ID, Initial Point Spec?).
+
+#### **73.9.54 Terminal Point Spec Param**
+
+- Parameter of Terminal Point Spec.
+- Choice between (Terminal Point Spec, Terminal Point Spec Macro).
+
+#### **73.9.55 Terminal Point Spec Macro**
+
+- Allows the specification of a macro parameter instead of a specified Terminal Point Spec value.
+- Sequence of (Macro Def ID, Terminal Point Spec?).
+
+#### **73.9.56 Initial Point Spec**
+
+- Initial position on the temporal axis.
+- Point Spec.
+
+#### **73.9.57 Terminal Point Spec**
+
+- Terminal position on the temporal axis.
+- Point Spec.
+
+#### **73.9.58 Transition Duration Param**
+
+- An optional parameter which can be provided for certain elementary actions within the presentation behaviour. It is expressed in GTU. When a transition duration is specified, the corresponding elementary action is to be processed during the specified duration, e.g. for set audible volume, the audible volume value changes gradually from its previous value to the specified value within the specified transition duration.
+- Generic Integer Param.
+
+## 73.10 Constants useful definitions
+
+Table 50/T.171 – Overview of Constants useful definitions
+
+|                                                                                            |
+|--------------------------------------------------------------------------------------------|
+| Event Data ::= <b>Value</b>                                                                |
+| Event ::= <b>List</b>                                                                      |
+| Channel Perceptability ::= <i>#on   #off</i>                                               |
+| Channel Availability Status ::= <i>#available   #not-available</i>                         |
+| Style ::= <b>List</b>                                                                      |
+| Max Interact Required ::= <b>Integer</b>                                                   |
+| Min Interact Required ::= <b>Integer</b>                                                   |
+| Modifiability ::= <i>#modifiable   #not-modifiable</i>                                     |
+| Selectability ::= <i>#selectable   #not-selectable</i>                                     |
+| Modification Status ::= <i>#modified   #not-modified   #modifying</i>                      |
+| Selection Status ::= <i>#selected   #not-selected</i>                                      |
+| Interaction Status ::= <b>Selection Status   Modification Status</b>                       |
+| Interaction Type ::= <i>#selection   #modification</i>                                     |
+| Interaction Type Macro ::= <b>Macro Def ID, Interaction Type?</b>                          |
+| Interaction Type Param ::= <b>Interaction Type   Interaction Type Macro</b>                |
+| Stream Identification ::= <b>Stream ID   #all-streams</b>                                  |
+| Stream Identification Macro ::= <b>Macro Def ID, Stream Identification?</b>                |
+| Stream Identification Param ::= <b>Stream Identification   Stream Identification Macro</b> |
+| Stream Chosen State ::= <i>#chosen   #not-chosen   #partially-chosen</i>                   |
+| Stream Choice ::= <b>Generic List</b>                                                      |
+| GVF ::= <b>GF</b>                                                                          |
+| PCV ::= <b>Integer   min-AVR   max-AVR</b>                                                 |
+| CV ::= <b>Integer   min-AVR   max-AVR</b>                                                  |
+| OV ::= <b>Integer   min-AVR   max-AVR</b>                                                  |
+| Point Type Param ::= <i>#absolute   #relative</i>                                          |
+| Spatial Control Macro ::= <b>Macro Def ID, Spatial Control?</b>                            |
+| Spatial Control Param ::= <b>Spatial Control   Spatial Control Macro</b>                   |
+| Expected Axis Result Param ::= <i>#x   #y   #z   #xyz</i>                                  |
+| User Spatial Control ::= <i>#allowed   #not-allowed</i>                                    |
+| Spatial Control ::= <i>#moving   #resizing   #scaling   #scrolling</i>                     |
+| GSF ::= <b>X GF?, Y GF?, Z GF?</b>                                                         |
+| PVS Position ::= <b>Spatial Position Spec</b>                                              |
+| PAP ::= <b>Spatial Position Spec</b>                                                       |
+| OVS Proj Strategy ::= <i>#fixed   #calculated</i>                                          |
+| OVS Position ::= <b>Spatial Position Spec</b>                                              |
+| OAP ::= <b>Spatial Position Spec</b>                                                       |
+| OVS ::= <b>Size Spec</b>                                                                   |
+
+**Table 50/T.171 – Overview of Constants useful definitions (*concluded*)**
+
+|                                                                                                                   |
+|-------------------------------------------------------------------------------------------------------------------|
+| Resizing Strategy ::= <i>#fixed</i>   <i>#minimum</i>   <i>#grows-only</i>                                        |
+| Aspect Ratio ::= <i>#preserved</i>   <i>#not-preserved</i>                                                        |
+| OS ::= <b>Size</b>                                                                                                |
+| Expected PVD Result ::= <i>#initial-temporal-position</i>   <i>#terminal-temporal-position</i>   <i>#duration</i> |
+| Expected PVD Result Macro ::= <b>Macro Def ID, Expected PVD Result?</b>                                           |
+| Expected PVD Result Param ::= <b>Expected PVD Result</b>   <b>Expected PVD Result Macro</b>                       |
+| Expected OVD Result ::= <i>#initial-temporal-position</i>   <i>#terminal-temporal-position</i>   <i>#duration</i> |
+| Expected OVD Result Macro ::= <b>Macro Def ID, Expected OVD Result?</b>                                           |
+| Expected OVD Result Param ::= <b>Expected OVD Result</b>   <b>Expected OVD Result Macro</b>                       |
+| Timestone ID ::= <b>Generic Integer</b>                                                                           |
+| Temporal Termination ::= <i>#freeze</i>   <i>#stop</i>                                                            |
+| OD ::= <b>Integer</b>   <i>#infinite</i>                                                                          |
+| Presentation Priority ::= <b>Generic Integer</b>   <i>#up-priority</i>   <i>#down-priority</i>                    |
+| Perceptability ::= <b>Generic Ratio</b>                                                                           |
+| RPS Assignment ::= <b>Channel Reference</b>   <b>Evaluated Reference</b>   <i>#prps</i>                           |
+| Ancestor ::= <b>Integer</b>   <i>#root</i>                                                                        |
+| Sibling ::= <b>Integer</b>                                                                                        |
+| EmptyChild ::= <b>Integer</b>   <i>#last</i>                                                                      |
+| Child ::= <b>Generic Integer</b>   <i>#last</i>   <i>#random</i>                                                  |
+| Navigation Command ::= <b>Child</b>   <b>EmptyChild</b>   <b>Sibling</b>   <b>Ancestor</b>                        |
+| Navigation Command Macro ::= <b>Macro Def ID, Navigation Command?</b>                                             |
+| Navigation Command Param ::= <b>Navigation Command</b>   <b>Navigation Command Macro</b>                          |
+| Termination Status ::= <i>#terminated</i>   <i>#not-terminated</i>                                                |
+| Running Status ::= <i>#running</i>   <i>#not-running</i>                                                          |
+| Rt-Availability Status ::= <i>#available</i>   <i>#not-available</i>                                              |
+| Activation Status ::= <i>#active</i>   <i>#inactive</i>                                                           |
+| Preparation Status ::= <i>#ready</i>   <i>#not-ready</i>                                                          |
+| Cat Ext Attribute Macro ::= <b>Macro Def ID, Cat Ext Attribute?</b>                                               |
+| Cat Ext Attribute Param ::= <b>Cat Ext Attribute</b>   <b>Cat Ext Attribute Macro</b>                             |
+| Update Command ::= <i>#add</i>   <i>#remove</i>   <i>#replace</i>                                                 |
+
+### 73.10.1 Event Data
+
+- Specifies an associated data with an event.
+- Value.
+
+### 73.10.2 Event
+
+- Specifies an event.
+- List.
+
+### **73.10.3 Channel Perceptability**
+
+- Specifies the channel perceptability. Choice between “on” and “off”.
+- Choice between (on, off).
+
+### **73.10.4 Channel Availability Status**
+
+- Indicates whether a channel is available.
+- Choice between (available, not-available).
+
+### **73.10.5 Style**
+
+- A catalogued entry, either registered or proprietary that gives a logical style to an rt-component.
+- List.
+
+### **73.10.6 Max Interact Required**
+
+- An integer greater than or equal to 0 to indicate the maximum interaction required for an rt-component.
+- Integer.
+
+### **73.10.7 Min Interact Required**
+
+- A integer greater than or equal to 0 to indicate the minimum interaction required for an rt-component.
+- Integer.
+
+### **73.10.8 Modifiability**
+
+- Indicates whether an rt-component is modifiable.
+- Choice between (modifiable, not-modifiable).
+
+### **73.10.9 Selectability**
+
+- Specifies a value of the maximum interaction required attribute for the selection of an rt-component.
+- Choice between (selectable, not-selectable).
+
+### **73.10.10 Modification Status**
+
+- Indicates the result of the user modification.
+- Choice between (modified, not-modified, modifying).
+
+### **73.10.11 Selection Status**
+
+- Indicates the results of the user selection.
+- Choice between (selected, not-selected).
+
+### **73.10.12 Interaction Status**
+
+- Indicates if an rt-component may be modified or selected.
+- Choice between (Selection Status, Modification Status).
+
+### **73.10.13 Interaction Type**
+
+- Specifies the interaction type.
+- Choice between (selection, modification).
+
+### **73.10.14 Interaction Type Macro**
+
+- Allows the specification of a macro parameter instead of a specified Interaction Type value.
+- Sequence of (Macro Def ID, Interaction Type?).
+
+### **73.10.15 Interaction Type Param**
+
+- Parameter of Interaction Type.
+- Choice between (Interaction Type, Interaction Type Macro).
+
+#### **73.10.16 Stream Identification**
+
+- Choice between a stream identifier or “all streams”.
+- Choice between (Stream ID, all-streams).
+
+#### **73.10.17 Stream Identification Macro**
+
+- Allows the specification of a macro parameter instead of a specified Stream Identification value.
+- Sequence of (Macro Def ID, Stream Identification?).
+
+#### **73.10.18 Stream Identification Param**
+
+- Parameter of Stream Identification.
+- Choice between (Stream Identification, Stream Identification Macro).
+
+#### **73.10.19 Stream Chosen State**
+
+- Indicates stream chosen state for each stream within an rt-mux, and for each rt-mux.
+- Choice between (chosen, not-chosen, partially-chosen).
+
+#### **73.10.20 Stream Choice**
+
+- A list of chosen stream IDs in an rt-mux.
+- Generic List.
+
+#### **73.10.21 GVF**
+
+- Specifies the GVF to be applied during the mapping of the OPS into its RPS.
+- GF.
+
+#### **73.10.22 PCV**
+
+- Specifies the PCV of a content object that is a projection of the CV to its parent RPS.
+- Choice between (Integer, min-AVR, max-AVR).
+
+#### **73.10.23 CV**
+
+- Specifies the CV of a content object. It is initialised by the OV and may be changed by using the Set CV action.
+- Choice between (Integer, min-AVR, max-AVR).
+
+#### **73.10.24 OV**
+
+- Specifies the OV of a content object. The OV shall be defined within the AVR. It is used to initialise the CV of each rt-content created from this content.
+- Choice between (Integer, min-AVR, max-AVR).
+
+#### **73.10.25 Point Type Param**
+
+- Choice between “absolute” and “relative”.
+- Choice between (absolute, relative).
+
+#### **73.10.26 Spatial Control Macro**
+
+- Allows the specification of a macro parameter instead of a specified Spatial Control value.
+- Sequence of (Macro Def ID, Spatial Control?).
+
+#### **73.10.27 Spatial Control Param**
+
+- Choice among “moving”, “resizing”, “scaling” and “scrolling”.
+- Choice between (Spatial Control, Spatial Control Macro).
+
+**73.10.28 Expected Axis Result Param**
+
+- Choice among “x”, “y”, “z” or “xyz”.
+- Choice between (x, y, z, xyz).
+
+**73.10.29 User Spatial Control**
+
+- Indicates functions of user spatial controls are allowed or not.
+- Choice between (allowed, not-allowed).
+
+**73.10.30 Spatial Control**
+
+- Indicates functions of user spatial controls.
+- Choice between (moving, resizing, scaling, scrolling).
+
+**73.10.31 GSF**
+
+- A set of three GF used for each axis.
+- Sequence of (X GF?, Y GF?, Z GF?).
+
+**73.10.32 PVS Position**
+
+- Specifies the Position of the PVS relatively to the origin of the OS or to another PVS.
+- Spatial Position Spec.
+
+**73.10.33 PAP**
+
+- Specifies the PAP of the PVS. It is used to position the PVS within the RPS.
+- Spatial Position Spec.
+
+**73.10.34 OVS Proj Strategy**
+
+- Specifies the projection strategy of the OVS to the PVS.
+- Choice between (fixed, calculated).
+
+**73.10.35 OVS Position**
+
+- Specifies the Position of the OVS relatively to the origin of the OS.
+- Spatial Position Spec.
+
+**73.10.36 OAP**
+
+- Specifies the OAP of the OVS. It is used to position the OVS within its OS.
+- Spatial Position Spec.
+
+**73.10.37 OVS**
+
+- Specifies the OVS of an rt-component. It is specified as a subset of the OS.
+- Size Spec.
+
+**73.10.38 Resizing Strategy**
+
+- Defines the resizing strategy of an rt-composite.
+- Choice between (fixed, minimum, grows-only).
+
+**73.10.39 Aspect Ratio**
+
+- Defines if the aspect ratio of an rt-component is to be preserved.
+- Choice between (preserved, not-preserved).
+
+**73.10.40 OS**
+
+- Specifies the OS of a component object or a channel. It is used to initialise the OS of an rt-component. It is also used to build the spatial axes of the OPS, of each rt-component created from this component, or the CPS.
+- Size.
+
+**73.10.41 Expected PVD Result**
+
+- Choice between (initial-temporal-position, terminal-temporal-position, duration).
+
+**73.10.42 Expected PVD Result Macro**
+
+- Allows the specification of a macro parameter instead of a specified Expected PVD Result value.
+- Sequence of (Macro Def ID, Expected PVD Result?).
+
+**73.10.43 Expected PVD Result Param**
+
+- Parameter of Expected PVD Result.
+- Choice between (Expected PVD Result, Expected PVD Result Macro).
+
+**73.10.44 Expected OVD Result**
+
+- Choice between (initial-temporal-position, terminal-temporal-position, duration).
+
+**73.10.45 Expected OVD Result Macro**
+
+- Allows the specification of a macro parameter instead of a specified Expected OVD Result value.
+- Sequence of (Macro Def ID, Expected OVD Result?).
+
+**73.10.46 Expected OVD Result Param**
+
+- Parameter of Expected OVD Result.
+- Choice between (Expected OVD Result, Expected OVD Result Macro).
+
+**73.10.47 Timestone ID**
+
+- A generic integer. The value 0 is reserved.
+- Generic Integer.
+
+**73.10.48 Temporal Termination**
+
+- Determines the presentation when a target reaches to the terminal temporal position.
+- Choice between (freeze, stop).
+
+**73.10.49 OD**
+
+- Specifies the OD of a component object or a channel. It is used to initialise the OD of an rt-component. It is also used to build the temporal axis of the OPS, of each rt-component created from this component, or the CPS.
+- Choice between (Integer, infinite).
+
+**73.10.50 Presentation Priority**
+
+- Determines the presentation stacking order of the rt-components assigned in a same RPS.
+- Choice between (Generic Integer, up-priority, down-priority).
+
+**73.10.51 Perceptability**
+
+- A ratio which defines the perceptability of an rt-component. If Perceptability Status is set to zero rt-content is not perceived. If it is set to 100 the original perception of the rt-content is perceived.
+- Generic Ratio.
+
+**73.10.52 RPS Assignment**
+
+- RPS is either a channel reference, an evaluated reference or PRPS.
+- Choice between (Channel Reference, Evaluated Reference, prps).
+
+**73.10.53 Ancestor**
+
+- Navigation path to reach an ancestor.
+- Choice between (Integer, root).
+
+#### **73.10.54 Sibling**
+
+- Navigation path to reach a relative sibling.
+- Integer.
+
+#### **73.10.55 EmptyChild**
+
+- Navigation path to reach an empty socket.
+- Choice between (Integer, last).
+
+#### **73.10.56 Child**
+
+- Navigation path to reach a child.
+- Choice between (Generic Integer, last, random).
+
+#### **73.10.57 Navigation Command**
+
+- It gives a navigation path.
+- Choice between (Child, EmptyChild, Sibling, Ancestor).
+
+#### **73.10.58 Navigation Command Macro**
+
+- Allows the specification of a macro parameter instead of a specified Navigation Command value.
+- Sequence of (Macro Def ID, Navigation Command?).
+
+#### **73.10.59 Navigation Command Param**
+
+- Parameter of Navigation Command.
+- Choice between (Navigation Command, Navigation Command Macro).
+
+#### **73.10.60 Termination Status**
+
+- Represents the process of an rt-script.
+- Choice between (terminated, not-terminated).
+
+#### **73.10.61 Running Status**
+
+- Indicates if an rt-object is running or not.
+- Choice between (running, not-running).
+
+#### **73.10.62 Rt-Availability Status**
+
+- Indicates if the rt-object has been created from model object or not.
+- Choice between (available, not-available).
+
+#### **73.10.63 Activation Status**
+
+- Indicates if a link object has been activated or not.
+- Choice between (active, inactive).
+
+#### **73.10.64 Preparation Status**
+
+- Indicates the availability of MHEG objects to the MHEG engine.
+- Choice between (ready, not-ready).
+
+#### **73.10.65 Cat Ext Attribute Macro**
+
+- Allows the specification of a macro parameter instead of a specified Cat Ext Attribute value.
+- Sequence of (Macro Def ID, Cat Ext Attribute?).
+
+### 73.10.66 Cat Ext Attribute Param
+
+- Parameter of Cat Ext Attribute.
+- Choice between (Cat Ext Attribute, Cat Ext Attribute Macro).
+
+### 73.10.67 Update Command
+
+- When an attribute of an MHEG entity takes a list of values, this parameter is provided in order to update this list of values. It is used in Set Alias action, Set Timestones action, Set Stream Choice action and Attach Anchor action. It is always used as Attribute Specification = List of (List of attribute value, Update Command)\*.
+
+The following applies:
+
+If the update command is equal to “replace”, the list of current attribute values of the target is removed and replaced by the list of attribute values provided as parameters of the elementary action.
+
+If the update command is equal to “add”, the list of attribute values provided as parameters of the elementary action is added to the current attribute values list of the target. It is ignored to add an attribute which already exists in the current attribute values list.
+
+If the update type is equal to “remove”, the list of attribute values currently provided as parameter of the elementary action is removed from the current attribute values list of the target. It is ignored to remove an attribute which does not exist in the current attribute values list.
+
+Combination of “add” and “remove” update commands may be used within a given attribute specification list. In that case, each command should be evaluated according to the order of the list.
+
+“replace” update command should not be used with “add” or/and “remove” within a given attribute specification list. If it is used with them, the elementary action shall be ignored.
+
+- Choice between (add, remove, replace).
+
+## 73.11 Comparison value constants
+
+**Table 51/T.171 – Overview of Comparison value constants**
+
+Comparison Value Constant ::=
+
+**Preparation Status | Activation Status | Rt-Availability Status | Running Status | Termination Status | #prps | #infinite | Temporal Termination | Aspect Ratio | Resizing Strategy | OVS Proj Strategy | User Spatial Control | Stream Chosen State | Selection Status | Modification Status | Channel Availability Status | Channel Perceptability**
+
+### 73.11.1 Comparison Value Constant
+
+- Specification of the constants defined by this Recommendation which can be used as a comparison value within a link condition of a link object.
+- Choice between (Preparation Status, Activation Status, Rt-Availability Status, Running Status, Termination Status, prps, infinite, Temporal Termination, Aspect Ratio, Resizing Strategy, OVS Proj Strategy, User Spatial Control, Stream Chosen State, Selection Status, Modification Status, Channel Availability Status, Channel Perceptability).
+
+## Annex A
+
+### ASN.1 notations (Level C) Coded representation (Level D)
+
+Useful definitions
+
+-- *Copyright statement:*
+
+-- -----
+
+-- *(c) International Organization for Standardization 1996.*
+
+-- *Permission to copy in any form is granted for use with conforming MHEG Engines and applications*
+
+-- *as defined in ITU-T Recommendation T.171 provided this notice is included in all copies.*
+
+--
+
+ISOMHEG-ud {joint-iso-itu-t(2) mheg(19) version(1) useful-definitions(9)}
+
+DEFINITIONS
+
+IMPLICIT TAGS
+
+::= BEGIN
+
+EXPORTS
+
+Aspect-Ratio,  
+Cat-Content-Classification,  
+Cat-Ext-Attribute,  
+Cat-Ext-Attribute-Param,  
+Catalogued-Event,  
+Catalogued-Extended-Elementary-Action,  
+Catalogued-Media-Type,  
+Catalogued-Script-Classification,  
+Catalogued-Style,  
+Channel-Perceptability,  
+Channel-Target-Param,  
+Class-ID,  
+Comparison-Value-Constant,  
+Component-Class,  
+Content-Hook,  
+Current-Point-Spec-Param,  
+Data-Reference,  
+Evaluated-Integer,  
+Evaluated-List,  
+Evaluated-Reference,  
+Evaluated-Value,  
+Generic-Integer,  
+Generic-Integer-Param,  
+Generic-List-ElT-ID-Param,  
+Generic-List-Param,  
+Generic-Numeric-Param,  
+Generic-Ratio-Param,  
+Generic-Value,  
+Generic-Value-Param,  
+GF-Param,  
+Initial-Point-Spec-Param,  
+Interaction-Status,  
+Interaction-Type-Param,  
+Macro-Def-ID,  
+Mh-object-Class,  
+Mh-Reference,  
+Mh-Target-Param,  
+Model-Class,  
+OVS-Proj-Strategy,  
+Point-Spec,  
+Point-Spec-Param,  
+Presentation-Priority,  
+Resizing-Strategy,  
+Return-Target-Param,  
+RPS-Assignment,  
+Rt-Component-Channel-Tg-Param,
+
+Rt-Component-Reference,  
+ Rt-Component-Target-Param,  
+ Rt-Composite-Target-Param,  
+ Rt-Content-Reference,  
+ Rt-Content-Target-Param,  
+ Rt-Mux-Target-Param,  
+ Rt-Script-Target-Param,  
+ Rt-Target-Param,  
+ Script-Hook,  
+ Size,  
+ Size-Spec-Param,  
+ Socket-Target-Param,  
+ Spatial-Control-Param,  
+ Spatial-Position-Spec-Param,  
+ Target-Param,  
+ Temporal-Termination,  
+ Terminal-Point-Spec-Param,  
+ Update-Command,  
+ User-Spatial-Control,  
+ Value,  
+ OV;
+
+#### IMPORTS
+
+Registered-Content-Encoding,  
+ Registered-Script-Encoding,  
+ Registered-Content-Classification,  
+ Registered-Script-Classification,  
+ Registered-Media-Type,  
+ Registered-Style,  
+ Registered-Event,  
+ Registered-Extended-Elementary-Action,  
+ Registered-Extended-Attribute FROM ISOMHEG-cat {joint-iso-itu-t(2) mheg(19) version(1) catalogues(12)};
+
+```
+
+Mh-object-Class ::= SEQUENCE    {
+mheg-id                Mheg-ID OPTIONAL,
+description            [0] Description OPTIONAL
+}
+Class-ID ::= CHOICE           {
+action-class-id        [0] INTEGER { action-class-id (1)},
+link-class-id          [1] INTEGER { link-class-id (2)},
+script-class-id        [2] INTEGER { script-class-id (3)},
+content-class-id       [3] INTEGER { content-class-id (4)},
+multiplexed-content-class-id [4] INTEGER { multiplexed-content-class-id (5)},
+composite-class-id     [5] INTEGER { composite-class-id (6)},
+container-class-id     [6] INTEGER { container-class-id (7)},
+descriptor-class-id    [7] INTEGER { descriptor-class-id (8)},
+...
+}
+Description ::= SEQUENCE      {
+name                   GraphicString OPTIONAL,
+owner                  [0] GraphicString OPTIONAL,
+version                [1] GraphicString OPTIONAL,
+date                   UTCTime OPTIONAL,
+keywords               SEQUENCE OF GraphicString OPTIONAL,
+copyright              [2] GraphicString OPTIONAL,
+copyright-id           OCTET STRING OPTIONAL,
+copyright-number       [3] OCTET STRING OPTIONAL,
+licence                [4] GraphicString OPTIONAL,
+cache-priority         INTEGER OPTIONAL,
+comments               [5] GraphicString OPTIONAL,
+...
+}
+Model-Class ::= SEQUENCE     {
+COMPONENTS OF Mh-object-Class
+}
+Component-Class ::= SEQUENCE {
+COMPONENTS OF Model-Class,
+ops-initialisation     [1] OPS-Initialisation OPTIONAL
+}
+  
+```
+
+|                                          |                                  |
+|------------------------------------------|----------------------------------|
+| Tail-Param ::= CHOICE                    | {                                |
+| tail                                     | SEQUENCE OF INTEGER,             |
+| tail-macro                               | [0] Tail-Macro                   |
+| }                                        |                                  |
+| Tail-Macro ::= SEQUENCE                  | {                                |
+| macro-def-id                             | Macro-Def-ID,                    |
+| tail                                     | SEQUENCE OF INTEGER OPTIONAL     |
+| }                                        |                                  |
+| External-ID ::= SEQUENCE                 | {                                |
+| public-id                                | PrintableString OPTIONAL,        |
+| system-id                                | OCTET STRING OPTIONAL            |
+| }                                        |                                  |
+| Mheg-ID ::= SEQUENCE                     | {                                |
+| application-id                           | OCTET STRING OPTIONAL,           |
+| mh-number                                | INTEGER                          |
+| }                                        |                                  |
+| Socket-Identification ::= CHOICE         | {                                |
+| socket-id                                | Socket-ID,                       |
+| alias                                    | GraphicString                    |
+| }                                        |                                  |
+| Socket-ID ::= SEQUENCE                   | {                                |
+| root-rt-composite-reference              | Root-Rt-Composite-Reference,     |
+| tail                                     | SEQUENCE OF INTEGER              |
+| }                                        |                                  |
+| Macro-Def-ID ::= CHOICE                  | {                                |
+| string                                   | GraphicString,                   |
+| integer                                  | INTEGER                          |
+| }                                        |                                  |
+| Reference ::= CHOICE                     | {                                |
+| null-data                                | NULL,                            |
+| mheg-id-reference                        | Mheg-ID,                         |
+| external-id-reference                    | [0] External-ID,                 |
+| container-element-reference              | [1] Container-Element-Reference, |
+| null-mh                                  | [2] NULL,                        |
+| this                                     | [3] NULL,                        |
+| stream-id-reference                      | [4] SEQUENCE OF INTEGER,         |
+| root-rt-id-reference                     | [5] Root-Rt-ID-Reference,        |
+| null-root-rt                             | [6] NULL,                        |
+| socket-id-reference                      | [7] Socket-ID-Reference,         |
+| channel-id-reference                     | INTEGER,                         |
+| default-channel                          | [8] NULL,                        |
+| alias-reference                          | GraphicString                    |
+| }                                        |                                  |
+| Tail-Reference ::= SEQUENCE              | {                                |
+| tail                                     | SEQUENCE OF INTEGER OPTIONAL,    |
+| tail-complement                          | Tail-Complement OPTIONAL         |
+| }                                        |                                  |
+| Tail-Complement ::= ENUMERATED           | {                                |
+| children (1),                            |                                  |
+| descendants (2)                          |                                  |
+| }                                        |                                  |
+| Data-Reference ::= CHOICE                | {                                |
+| external-id                              | External-ID,                     |
+| null-data                                | [0] NULL,                        |
+| alias-reference                          | GraphicString                    |
+| }                                        |                                  |
+| Mh-Reference ::= CHOICE                  | {                                |
+| mheg-id-reference                        | Mheg-ID,                         |
+| external-id-reference                    | [0] External-ID,                 |
+| container-element-reference              | [1] Container-Element-Reference, |
+| null-mh                                  | NULL,                            |
+| this                                     | [2] NULL,                        |
+| alias-reference                          | GraphicString                    |
+| }                                        |                                  |
+| Container-Element-Reference ::= SEQUENCE | {                                |
+| container-object-reference               | Mh-Reference,                    |
+| tail-reference                           | Tail-Reference                   |
+| }                                        |                                  |
+
+```
+
+Root-Rt-Reference ::= CHOICE      {
+root-rt-id-reference          Root-Rt-ID-Reference,
+null-root-rt                  NULL,
+alias-reference                GraphicString
+}
+Root-Rt-ID-Reference ::= SEQUENCE {
+model-object-reference        Mh-Reference,
+rt-number-reference           Rt-Number-Reference
+}
+Rt-Number-Reference ::= CHOICE    {
+rt-number                     INTEGER,
+question-mark                  [0] INTEGER { question-mark (1)},
+star                           [1] INTEGER { star (2)}
+}
+Rt-Reference ::= CHOICE          {
+root-rt-id-reference          Root-Rt-ID-Reference,
+null-root-rt                  NULL,
+socket-id-reference           [0] Socket-ID-Reference,
+alias-reference                GraphicString
+}
+Rt-Script-Reference ::= CHOICE   {
+rt-script-id-reference         Rt-Script-ID-Reference,
+null-root-rt                  NULL,
+alias-reference                GraphicString
+}
+Rt-Script-ID-Reference ::= SEQUENCE {
+script-object-reference        Mh-Reference,
+rt-number-reference           Rt-Number-Reference
+}
+Root-Rt-Component-Reference ::= CHOICE {
+root-rt-component-id-ref      Root-Rt-Component-ID-Ref,
+null-root-rt                  NULL,
+alias-reference                GraphicString
+}
+Root-Rt-Component-ID-Ref ::= SEQUENCE {
+component-object-reference     Mh-Reference,
+rt-number-reference           Rt-Number-Reference
+}
+Rt-Component-Reference ::= CHOICE {
+root-rt-component-id-ref      [10] Root-Rt-Component-ID-Ref,
+null-root-rt                  [11] NULL,
+socket-id-reference           [12] Socket-ID-Reference,
+alias-reference                [13] GraphicString
+}
+Root-Rt-Content-Reference ::= CHOICE {
+root-rt-content-id-ref        Root-Rt-Content-ID-Ref,
+null-root-rt                  NULL,
+alias-reference                GraphicString
+}
+Root-Rt-Content-ID-Ref ::= SEQUENCE {
+content-object-ref            Mh-Reference,
+rt-number-reference           Rt-Number-Reference
+}
+Rt-Content-Reference ::= CHOICE   {
+root-rt-content-id-ref        Root-Rt-Content-ID-Ref,
+null-root-rt                  NULL,
+socket-id-reference           [0] Socket-ID-Reference,
+alias-reference                GraphicString
+}
+Root-Rt-Mux-Reference ::= CHOICE  {
+root-rt-mux-id-reference       Root-Rt-Mux-ID-Reference,
+null-root-rt                  NULL,
+alias-reference                GraphicString
+}
+Root-Rt-Mux-ID-Reference ::= SEQUENCE {
+multiplexed-content-object-ref Mh-Reference,
+rt-number-reference           Rt-Number-Reference
+}
+
+```
+
+```
+
+Rt-Mux-Reference ::= CHOICE      {
+root-rt-mux-id-reference      Root-Rt-Mux-ID-Reference,
+null-root-rt                  NULL,
+socket-id-reference           [0] Socket-ID-Reference,
+alias-reference               GraphicString
+}
+Root-Rt-Composite-Reference ::= CHOICE      {
+root-rt-composite-id-ref      Root-Rt-Composite-ID-Ref,
+null-root-rt                  NULL,
+alias-reference               GraphicString
+}
+Root-Rt-Composite-ID-Ref ::= SEQUENCE      {
+composite-object-reference     Mh-Reference,
+rt-number-reference           Rt-Number-Reference
+}
+Rt-Composite-Reference ::= CHOICE      {
+root-rt-composite-id-ref      [28] Root-Rt-Composite-ID-Ref,
+null-root-rt                  [29] NULL,
+socket-id-reference           [30] Socket-ID-Reference,
+alias-reference               [31] GraphicString
+}
+Socket-Reference ::= CHOICE      {
+socket-id-reference           Socket-ID-Reference,
+alias-reference               GraphicString
+}
+Socket-ID-Reference ::= SEQUENCE      {
+root-rt-composite-reference   Root-Rt-Composite-Reference,
+socket-tail-reference         Socket-Tail-Reference
+}
+Socket-Tail-Reference ::= SEQUENCE      {
+tail                           SEQUENCE OF INTEGER OPTIONAL,
+socket-tail-complement        Socket-Tail-Complement OPTIONAL
+}
+Socket-Tail-Complement ::= CHOICE      {
+tail-complement               Tail-Complement,
+question-mark-child           INTEGER { question-mark-child (1)},
+question-mark-descendant     [0] INTEGER { question-mark-descendant (2)}
+}
+Channel-Reference ::= CHOICE      {
+channel-id-reference           [34] INTEGER,
+default-channel               [35] NULL,
+alias-reference               [36] GraphicString
+}
+Rt-Component-Channel-Ref ::= CHOICE      {
+rt-component-reference         [41] Rt-Component-Reference,
+channel-reference             [42] Channel-Reference
+}
+Target-Param ::= CHOICE      {
+target                         Generic-Reference,
+target-macro                   [45] Target-Macro
+}
+Target-Macro ::= SEQUENCE      {
+macro-def-id                   Macro-Def-ID,
+target                         Generic-Reference OPTIONAL
+}
+Mh-Target-Param ::= CHOICE      {
+mh-target                     [2] Mh-Target,
+mh-target-macro                [3] Mh-Target-Macro
+}
+Mh-Target-Macro ::= SEQUENCE      {
+macro-def-id                   Macro-Def-ID,
+mh-target                     Mh-Target OPTIONAL
+}
+Mh-Target ::= CHOICE      {
+mh-reference                   Mh-Reference,
+evaluated-reference            Evaluated-Reference
+}
+
+```
+
+```
+
+Rt-Target-Param ::= CHOICE      {
+rt-target                [5] Rt-Target,
+rt-target-macro          [6] Rt-Target-Macro
+}
+Rt-Target-Macro ::= SEQUENCE   {
+macro-def-id             Macro-Def-ID,
+rt-target                Rt-Target OPTIONAL
+}
+Rt-Target ::= CHOICE           {
+rt-reference              Rt-Reference,
+evaluated-reference      Evaluated-Reference
+}
+Rt-Script-Target-Param ::= CHOICE {
+rt-script-target         [8] Rt-Script-Target,
+rt-script-target-macro   [9] Rt-Script-Target-Macro
+}
+Rt-Script-Target-Macro ::= SEQUENCE {
+macro-def-id             Macro-Def-ID,
+rt-script-target         Rt-Script-Target OPTIONAL
+}
+Rt-Script-Target ::= CHOICE    {
+rt-script-reference      Rt-Script-Reference,
+evaluated-reference      Evaluated-Reference
+}
+Rt-Component-Target-Param ::= CHOICE {
+rt-component-target      Rt-Component-Target,
+rt-component-target-macro [15] Rt-Component-Target-Macro
+}
+Rt-Component-Target-Macro ::= SEQUENCE {
+macro-def-id             Macro-Def-ID,
+rt-component-target      Rt-Component-Target OPTIONAL
+}
+Rt-Component-Target ::= CHOICE {
+rt-component-reference    Rt-Component-Reference,
+evaluated-reference       [14] Evaluated-Reference
+}
+Rt-Content-Target-Param ::= CHOICE {
+rt-content-target        [26] Rt-Content-Target,
+rt-content-target-macro   [27] Rt-Content-Target-Macro
+}
+Rt-Content-Target-Macro ::= SEQUENCE {
+macro-def-id             Macro-Def-ID,
+rt-content-target        Rt-Content-Target OPTIONAL
+}
+Rt-Content-Target ::= CHOICE {
+rt-content-reference      Rt-Content-Reference,
+evaluated-reference       Evaluated-Reference
+}
+Rt-Mux-Target-Param ::= CHOICE {
+rt-mux-target            [45] Rt-Mux-Target,
+rt-mux-target-macro      [46] Rt-Mux-Target-Macro
+}
+Rt-Mux-Target-Macro ::= SEQUENCE {
+macro-def-id             Macro-Def-ID,
+rt-mux-target            Rt-Mux-Target OPTIONAL
+}
+Rt-Mux-Target ::= CHOICE {
+rt-mux-reference         Rt-Mux-Reference,
+evaluated-reference       Evaluated-Reference
+}
+Rt-Composite-Target-Param ::= CHOICE {
+rt-composite-target      Rt-Composite-Target,
+rt-composite-target-macro [33] Rt-Composite-Target-Macro
+}
+Rt-Composite-Target-Macro ::= SEQUENCE {
+macro-def-id             Macro-Def-ID,
+rt-composite-target      Rt-Composite-Target OPTIONAL
+}
+
+```
+
+```
+
+Rt-Composite-Target ::= CHOICE {
+rt-composite-reference      Rt-Composite-Reference,
+evaluated-reference        [32] Evaluated-Reference
+}
+Socket-Target-Param ::= CHOICE {
+socket-target               Socket-Target,
+socket-target-macro         [0] Socket-Target-Macro
+}
+Socket-Target-Macro ::= SEQUENCE {
+macro-def-id               Macro-Def-ID,
+socket-target               Socket-Target OPTIONAL
+}
+Socket-Target ::= CHOICE {
+socket-reference            Socket-Reference,
+evaluated-reference        Evaluated-Reference
+}
+Return-Target-Param ::= CHOICE {
+generic-integer-param       Generic-Integer-Param,
+using-application           NULL
+}
+Channel-Target-Param ::= CHOICE {
+channel-target              Channel-Target,
+channel-target-macro        [38] Channel-Target-Macro
+}
+Channel-Target-Macro ::= SEQUENCE {
+macro-def-id               Macro-Def-ID,
+channel-target              Channel-Target OPTIONAL
+}
+Channel-Target ::= CHOICE {
+channel-reference           Channel-Reference,
+evaluated-reference         [37] Evaluated-Reference
+}
+Rt-Component-Channel-Tg-Param ::= CHOICE {
+rt-component-channel-tg     Rt-Component-Channel-Tg,
+rt-component-channel-tg-macro [44] Rt-Component-Channel-Tg-Macro
+}
+Rt-Component-Channel-Tg-Macro ::= SEQUENCE {
+macro-def-id               Macro-Def-ID,
+rt-component-channel-tg     Rt-Component-Channel-Tg OPTIONAL
+}
+Rt-Component-Channel-Tg ::= CHOICE {
+rt-component-channel-ref     Rt-Component-Channel-Ref,
+evaluated-reference          [43] Evaluated-Reference
+}
+Generic-Value-Param ::= CHOICE {
+generic-value               Generic-Value,
+generic-value-macro         [50] Generic-Value-Macro
+}
+Generic-Value-Macro ::= SEQUENCE {
+macro-def-id               Macro-Def-ID,
+generic-value               Generic-Value OPTIONAL
+}
+Generic-Value ::= CHOICE {
+value                       Value,
+evaluated-value             Evaluated-Value
+}
+Value ::= CHOICE {
+boolean                     BOOLEAN,
+numeric                     INTEGER,
+ratio                       Ratio,
+string                      GraphicString,
+list                        [0] SEQUENCE OF Value,
+reference                    [1] Reference
+}
+Generic-Boolean-Param ::= CHOICE {
+generic-boolean             Generic-Boolean,
+generic-boolean-macro       Generic-Boolean-Macro
+}
+
+```
+
+```
+
+Generic-Boolean-Macro ::= SEQUENCE    {
+macro-def-id           Macro-Def-ID,
+generic-boolean        Generic-Boolean OPTIONAL
+}
+Generic-Boolean ::= CHOICE           {
+boolean                BOOLEAN,
+evaluated-boolean      Evaluated-Boolean
+}
+Generic-Numeric-Param ::= CHOICE     {
+generic-numeric        Generic-Numeric,
+generic-numeric-macro  Generic-Numeric-Macro
+}
+Generic-Numeric-Macro ::= SEQUENCE   {
+macro-def-id           Macro-Def-ID,
+generic-numeric        Generic-Numeric OPTIONAL
+}
+Generic-Numeric ::= CHOICE           {
+numeric                INTEGER,
+evaluated-numeric      Evaluated-Numeric
+}
+Generic-Integer-Param ::= CHOICE     {
+generic-integer        Generic-Integer,
+generic-integer-macro  Generic-Integer-Macro
+}
+Generic-Integer-Macro ::= SEQUENCE   {
+macro-def-id           Macro-Def-ID,
+generic-integer        Generic-Integer OPTIONAL
+}
+Generic-Integer ::= CHOICE           {
+integer                INTEGER,
+evaluated-integer      Evaluated-Integer
+}
+Generic-Ratio-Param ::= CHOICE       {
+generic-ratio          Generic-Ratio,
+generic-ratio-macro    [0] Generic-Ratio-Macro
+}
+Generic-Ratio-Macro ::= SEQUENCE     {
+macro-def-id           Macro-Def-ID,
+generic-ratio          Generic-Ratio OPTIONAL
+}
+Generic-Ratio ::= CHOICE             {
+ratio                  Ratio,
+evaluated-ratio        Evaluated-Ratio
+}
+Ratio ::= SEQUENCE                   {
+numerator              INTEGER,
+denominator            INTEGER OPTIONAL
+}
+Generic-String-Param ::= CHOICE      {
+generic-string         Generic-String,
+generic-string-macro   Generic-String-Macro
+}
+Generic-String-Macro ::= SEQUENCE    {
+macro-def-id           Macro-Def-ID,
+generic-string         Generic-String OPTIONAL
+}
+Generic-String ::= CHOICE            {
+string                 GraphicString,
+evaluated-string       Evaluated-String
+}
+Generic-Reference-Param ::= CHOICE   {
+generic-reference      Generic-Reference,
+generic-reference-macro [45] Generic-Reference-Macro
+}
+
+```
+
+```
+
+Generic-Reference-Macro ::= SEQUENCE {
+macro-def-id           Macro-Def-ID,
+generic-reference      Generic-Reference OPTIONAL
+}
+Generic-Reference ::= CHOICE {
+reference              Reference,
+evaluated-reference    Evaluated-Reference
+}
+Generic-List-Param ::= CHOICE {
+generic-list           Generic-List,
+generic-list-macro     [1] Generic-List-Macro
+}
+Generic-List-Macro ::= SEQUENCE {
+macro-def-id           Macro-Def-ID,
+generic-list           Generic-List OPTIONAL
+}
+Generic-List ::= CHOICE {
+list                  SEQUENCE OF Value,
+evaluated-list        Evaluated-List
+}
+Generic-List-Elt-ID-Param ::= CHOICE {
+generic-list-elt-id    SEQUENCE OF INTEGER,
+generic-list-elt-id-macro [0] Generic-List-Elt-ID-Macro
+}
+Generic-List-Elt-ID-Macro ::= SEQUENCE {
+macro-def-id           Macro-Def-ID,
+generic-list-elt-id    SEQUENCE OF INTEGER OPTIONAL
+}
+Get-Number-Of-Interacted-Sockets ::= SEQUENCE {
+rt-composite-target-param Rt-Composite-Target-Param,
+interaction-type-param    Interaction-Type-Param
+}
+Get-Interaction-Status ::= SEQUENCE {
+rt-component-target-param Rt-Component-Target-Param,
+interaction-type-param    Interaction-Type-Param
+}
+Get-Max-Interact-Required ::= SEQUENCE {
+rt-component-target-param Rt-Component-Target-Param,
+interaction-type-param    Interaction-Type-Param
+}
+Get-Min-Interact-Required ::= SEQUENCE {
+rt-component-target-param Rt-Component-Target-Param,
+interaction-type-param    Interaction-Type-Param
+}
+Get-Interaction-Ability ::= SEQUENCE {
+rt-component-target-param Rt-Component-Target-Param,
+interaction-type-param    Interaction-Type-Param
+}
+Get-Stream-Chosen-State ::= SEQUENCE {
+rt-mux-target-param      Rt-Mux-Target-Param,
+stream-identification-param Stream-Identification-Param
+}
+Get-GVF ::= CHOICE {
+rt-composite-target-param Rt-Composite-Target-Param,
+channel-target-param      Channel-Target-Param
+}
+Get-User-Spatial-Control ::= SEQUENCE {
+rt-component-target-param Rt-Component-Target-Param,
+spatial-control-param     Spatial-Control-Param
+}
+Get-GSF ::= SEQUENCE {
+rt-component-target-param Rt-Component-Target-Param,
+expected-axis-result-param Expected-Axis-Result-Param
+}
+Get-PVS-Position ::= SEQUENCE {
+rt-component-target-param Rt-Component-Target-Param,
+point-type-param         Point-Type-Param,
+expected-axis-result-param Expected-Axis-Result-Param
+}
+
+```
+
+|                                       |                                    |
+|---------------------------------------|------------------------------------|
+| Get-PAP ::= SEQUENCE                  | {                                  |
+| rt-component-target-param             | Rt-Component-Target-Param,         |
+| point-type-param                      | Point-Type-Param,                  |
+| expected-axis-result-param            | Expected-Axis-Result-Param         |
+| }                                     |                                    |
+| Get-PVS ::= SEQUENCE                  | {                                  |
+| rt-component-target-param             | Rt-Component-Target-Param,         |
+| point-type-param                      | Point-Type-Param,                  |
+| expected-axis-result-param            | Expected-Axis-Result-Param         |
+| }                                     |                                    |
+| Get-OVS-Position ::= SEQUENCE         | {                                  |
+| rt-component-target-param             | Rt-Component-Target-Param,         |
+| point-type-param                      | Point-Type-Param,                  |
+| expected-axis-result-param            | Expected-Axis-Result-Param         |
+| }                                     |                                    |
+| Get-OAP ::= SEQUENCE                  | {                                  |
+| rt-component-target-param             | Rt-Component-Target-Param,         |
+| point-type-param                      | Point-Type-Param,                  |
+| expected-axis-result-param            | Expected-Axis-Result-Param         |
+| }                                     |                                    |
+| Get-OVS ::= SEQUENCE                  | {                                  |
+| rt-component-target-param             | Rt-Component-Target-Param,         |
+| point-type-param                      | Point-Type-Param,                  |
+| expected-axis-result-param            | Expected-Axis-Result-Param         |
+| }                                     |                                    |
+| Get-POS ::= SEQUENCE                  | {                                  |
+| rt-component-target-param             | Rt-Component-Target-Param,         |
+| expected-axis-result-param            | Expected-Axis-Result-Param         |
+| }                                     |                                    |
+| Get-OS ::= SEQUENCE                   | {                                  |
+| rt-component-target-param             | Rt-Component-Target-Param,         |
+| expected-axis-result-param            | Expected-Axis-Result-Param         |
+| }                                     |                                    |
+| Get-PVD ::= SEQUENCE                  | {                                  |
+| rt-component-target-param             | Rt-Component-Target-Param,         |
+| expected-pvd-result-param             | Expected-PVD-Result-Param          |
+| }                                     |                                    |
+| Get-OVD ::= SEQUENCE                  | {                                  |
+| rt-component-target-param             | Rt-Component-Target-Param,         |
+| expected-ovd-result-param             | Expected-OVD-Result-Param          |
+| }                                     |                                    |
+| Get-Rt-Composite-Address ::= SEQUENCE |                                    |
+| {                                     |                                    |
+| rt-composite-target-param             | Rt-Composite-Target-Param,         |
+| navigation-command-param              | Navigation-Command-Param           |
+| }                                     |                                    |
+| Get-Data ::= SEQUENCE                 | {                                  |
+| content-target-param                  | Mh-Target-Param,                   |
+| generic-list-elt-id-param             | Generic-List-Elt-ID-Param OPTIONAL |
+| }                                     |                                    |
+| Get-Catalogued-Attribute ::= SEQUENCE | {                                  |
+| target-param                          | Target-Param,                      |
+| cat-ext-attribute-param               | Cat-Ext-Attribute-Param            |
+| }                                     |                                    |
+| Get-Integer ::= CHOICE                | {                                  |
+| get-preparation-status                | Mh-Target-Param,                   |
+| get-activation-status                 | [4] Mh-Target-Param,               |
+| get-rt-availability-status            | Rt-Target-Param,                   |
+| get-running-status                    | [7] Rt-Target-Param,               |
+| get-termination-status                | Rt-Script-Target-Param,            |
+| get-presentation-priority             | Rt-Component-Target-Param,         |
+| get-od                                | [16] Rt-Component-Target-Param,    |
+| get-pod                               | [17] Rt-Component-Target-Param,    |
+| get-pvd                               | [18] Get-PVD,                      |
+| get-ctp                               | [19] Rt-Component-Target-Param,    |
+| get-temporal-termination              | [20] Rt-Component-Target-Param,    |
+| get-pvd-position                      | [21] Rt-Component-Target-Param,    |
+
+|                                  |                                        |
+|----------------------------------|----------------------------------------|
+| get-timestone-status             | [22] Rt-Component-Target-Param,        |
+| get-aspect-ratio                 | [23] Rt-Component-Target-Param,        |
+| get-resizing-strategy            | Rt-Composite-Target-Param,             |
+| get-ovs-proj-strategy            | [24] Rt-Component-Target-Param,        |
+| get-user-spatial-control         | [25] Get-User-Spatial-Control,         |
+| get-cv                           | Rt-Content-Target-Param,               |
+| get-pcv                          | [34] Rt-Content-Target-Param,          |
+| get-stream-chosen-state          | [35] Get-Stream-Chosen-State,          |
+| get-min-interact-required        | [36] Get-Min-Interact-Required,        |
+| get-max-interact-required        | [37] Get-Max-Interact-Required,        |
+| get-number-of-interacted-sockets | [38] Get-Number-Of-Interacted-Sockets, |
+| get-channel-availability-status  | [39] Channel-Target-Param,             |
+| get-channel-perceptability       | [40] Channel-Target-Param              |
+| }                                |                                        |
+| Get-Reference ::= CHOICE         | {                                      |
+| get-rt-composite-address         | [9] Get-Rt-Composite-Address,          |
+| get-rps-assignment               | Rt-Component-Target-Param              |
+| }                                |                                        |
+| Get-List ::= CHOICE              | {                                      |
+| get-catalogued-attribute         | [44] Get-Catalogued-Attribute,         |
+| get-stream-choice                | Rt-Mux-Target-Param,                   |
+| get-style                        | [47] Rt-Component-Target-Param,        |
+| get-event                        | [48] Rt-Component-Channel-Tg-Param     |
+| }                                |                                        |
+| Get-Any ::= CHOICE               | {                                      |
+| get-data                         | [16] Get-Data,                         |
+| get-ovd                          | [17] Get-OVD,                          |
+| get-gtf                          | [18] Rt-Component-Target-Param,        |
+| get-os                           | [19] Get-OS,                           |
+| get-pos                          | [20] Get-POS,                          |
+| get-ovs                          | [21] Get-OVS,                          |
+| get-oap                          | [22] Get-OAP,                          |
+| get-ovs-position                 | [23] Get-OVS-Position,                 |
+| get-pvs                          | [24] Get-PVS,                          |
+| get-pap                          | [25] Get-PAP,                          |
+| get-pvs-position                 | [26] Get-PVS-Position,                 |
+| get-gsf                          | [27] Get-GSF,                          |
+| get-gvf                          | Get-GVF,                               |
+| get-interaction-ability          | [39] Get-Interaction-Ability,          |
+| get-interaction-status           | [40] Get-Interaction-Status,           |
+| get-event-data                   | Rt-Component-Channel-Tg-Param          |
+| }                                |                                        |
+| Evaluated-Value ::= CHOICE       | {                                      |
+| get-boolean                      | NULL,                                  |
+| get-numeric                      | Get-Integer,                           |
+| get-ratio                        | [41] Rt-Component-Target-Param,        |
+| get-string                       | [42] NULL,                             |
+| get-reference                    | [43] Get-Reference,                    |
+| get-list                         | Get-List,                              |
+| get-any                          | [49] Get-Any,                          |
+| ...                              |                                        |
+| }                                |                                        |
+| Evaluated-Boolean ::= CHOICE     | {                                      |
+| get-boolean                      | NULL,                                  |
+| get-any                          | Get-Any                                |
+| }                                |                                        |
+| Evaluated-Numeric ::= CHOICE     | {                                      |
+| get-numeric                      | Get-Integer,                           |
+| get-integer                      | [0] Get-Integer,                       |
+| get-any                          | [1] Get-Any                            |
+| }                                |                                        |
+| Evaluated-Integer ::= CHOICE     | {                                      |
+| get-integer                      | Get-Integer,                           |
+| get-any                          | [41] Get-Any                           |
+| }                                |                                        |
+| Evaluated-Ratio ::= CHOICE       | {                                      |
+| get-ratio                        | Rt-Component-Target-Param,             |
+| get-any                          | Get-Any                                |
+| }                                |                                        |
+
+```
+
+Evaluated-String ::= CHOICE      {
+get-string          NULL,
+get-any             Get-Any
+}
+Evaluated-Reference ::= CHOICE  {
+get-reference       Get-Reference,
+get-any             Get-Any
+}
+Evaluated-List ::= CHOICE      {
+get-list            Get-List,
+get-any             [0] Get-Any
+}
+Content-Hook ::= SEQUENCE      {
+catalogued-content-encoding  Catalogued-Content-Encoding OPTIONAL,
+content-encoding-description [0] OCTET STRING OPTIONAL
+}
+Script-Hook ::= SEQUENCE      {
+catalogued-script-encoding   Catalogued-Script-Encoding OPTIONAL,
+script-encoding-description [0] OCTET STRING OPTIONAL
+}
+Catalogued-Content-Encoding ::= CHOICE      {
+registered-content-encoding   Registered-Content-Encoding,
+proprietary-content-encoding Prop-Cat-Entry-ID
+}
+Catalogued-Script-Encoding ::= CHOICE      {
+registered-script-encoding    Registered-Script-Encoding,
+proprietary-script-encoding   Prop-Cat-Entry-ID
+}
+Cat-Content-Classification ::= CHOICE      {
+registered-content-classification Registered-Content-Classification,
+prop-content-classification      Prop-Cat-Entry-ID
+}
+Catalogued-Script-Classification ::= CHOICE {
+registered-script-classification Registered-Script-Classification,
+prop-script-classification      Prop-Cat-Entry-ID
+}
+Catalogued-Media-Type ::= CHOICE      {
+registered-media-type          Registered-Media-Type,
+proprietary-media-type         Prop-Cat-Entry-ID
+}
+Catalogued-Style ::= CHOICE      {
+registered-style               Registered-Style,
+proprietary-style              Prop-Cat-Entry-ID
+}
+Catalogued-Event ::= CHOICE      {
+registered-event               Registered-Event,
+proprietary-event              Prop-Cat-Entry-ID
+}
+Catalogued-Extended-Elementary-Action ::= CHOICE      {
+registered-extended-elementary-action Registered-Extended-Elementary-Action,
+proprietary-extended-elementary-action Prop-Cat-Entry-ID
+}
+Cat-Ext-Attribute ::= CHOICE      {
+registered-extended-attribute Registered-Extended-Attribute,
+proprietary-extended-attribute Prop-Cat-Entry-ID
+}
+Prop-Cat-Entry-ID ::= CHOICE      {
+tail          SEQUENCE OF INTEGER,
+octet-string  OCTET STRING
+}
+OPS-Initialisation ::= SEQUENCE      {
+od          OD OPTIONAL,
+os          Size OPTIONAL
+}
+
+```
+
+|                                        |                                               |
+|----------------------------------------|-----------------------------------------------|
+| GF-Param ::= CHOICE                    | {                                             |
+| gf                                     | GF,                                           |
+| gf-macro                               | [0] GF-Macro                                  |
+| }                                      |                                               |
+| GF-Macro ::= SEQUENCE                  | {                                             |
+| macro-def-id                           | Macro-Def-ID,                                 |
+| gf                                     | GF OPTIONAL                                   |
+| }                                      |                                               |
+| GF ::= CHOICE                          | {                                             |
+| generic-ratio                          | Generic-Ratio,                                |
+| default-gf                             | INTEGER { default-gf (1)}                     |
+| }                                      |                                               |
+| Point ::= CHOICE                       | {                                             |
+| integer                                | INTEGER,                                      |
+| terminal                               | [0] INTEGER { terminal (1)}                   |
+| }                                      |                                               |
+| Size ::= SEQUENCE                      | {                                             |
+| x-spatial-length                       | Spatial-Length OPTIONAL,                      |
+| y-spatial-length                       | [1] Spatial-Length OPTIONAL,                  |
+| z-spatial-length                       | [2] Spatial-Length OPTIONAL                   |
+| }                                      |                                               |
+| Spatial-Length ::= CHOICE              | {                                             |
+| length                                 | INTEGER,                                      |
+| default-spatial-length                 | [0] INTEGER { default-spatial-length (65536)} |
+| }                                      |                                               |
+| Size-Spec-Param ::= CHOICE             | {                                             |
+| size-spec                              | Size-Spec,                                    |
+| size-spec-macro                        | [0] Size-Spec-Macro                           |
+| }                                      |                                               |
+| Size-Spec-Macro ::= SEQUENCE           | {                                             |
+| macro-def-id                           | Macro-Def-ID,                                 |
+| size-spec                              | Size-Spec OPTIONAL                            |
+| }                                      |                                               |
+| Size-Spec ::= CHOICE                   | {                                             |
+| lengths-spec                           | Lengths-Spec,                                 |
+| get-list                               | Get-List,                                     |
+| get-any                                | [50] Get-Any                                  |
+| }                                      |                                               |
+| Lengths-Spec ::= SEQUENCE              | {                                             |
+| x-length-spec                          | [2] Length-Spec OPTIONAL,                     |
+| y-length-spec                          | [0] Length-Spec OPTIONAL,                     |
+| z-length-spec                          | [1] Length-Spec OPTIONAL                      |
+| }                                      |                                               |
+| Length-Spec-Param ::= CHOICE           | {                                             |
+| length-spec                            | Length-Spec,                                  |
+| length-spec-macro                      | [0] Length-Spec-Macro                         |
+| }                                      |                                               |
+| Length-Spec-Macro ::= SEQUENCE         | {                                             |
+| macro-def-id                           | Macro-Def-ID,                                 |
+| length-spec                            | Length-Spec OPTIONAL                          |
+| }                                      |                                               |
+| Length-Spec ::= CHOICE                 | {                                             |
+| length                                 | INTEGER,                                      |
+| relative-length                        | Ratio,                                        |
+| get-integer                            | Get-Integer,                                  |
+| get-ratio                              | [46] Rt-Component-Target-Param,               |
+| get-any                                | [45] Get-Any                                  |
+| }                                      |                                               |
+| Spatial-Position ::= SEQUENCE          | {                                             |
+| x-point                                | Point OPTIONAL,                               |
+| y-point                                | [1] Point OPTIONAL,                           |
+| z-point                                | [2] Point OPTIONAL                            |
+| }                                      |                                               |
+| Spatial-Position-Spec-Param ::= CHOICE | {                                             |
+| spatial-position-spec                  | Spatial-Position-Spec,                        |
+| spatial-position-spec-macro            | [0] Spatial-Position-Spec-Macro               |
+| }                                      |                                               |
+
+```
+
+Spatial-Position-Spec-Macro ::= SEQUENCE    {
+macro-def-id                Macro-Def-ID,
+spatial-position-spec       Spatial-Position-Spec OPTIONAL
+}
+Spatial-Position-Spec ::= CHOICE    {
+points-spec                 Points-Spec,
+get-list                   Get-List,
+get-any                    [51] Get-Any
+}
+Points-Spec ::= SEQUENCE    {
+x-point-spec               [3] Point-Spec OPTIONAL,
+y-point-spec               [1] Point-Spec OPTIONAL,
+z-point-spec               [2] Point-Spec OPTIONAL
+}
+Point-Spec-Param ::= CHOICE    {
+point-spec                 Point-Spec,
+point-spec-macro           [1] Point-Spec-Macro
+}
+Point-Spec-Macro ::= SEQUENCE    {
+macro-def-id                Macro-Def-ID,
+point-spec                 Point-Spec OPTIONAL
+}
+Point-Spec ::= CHOICE    {
+point                      Point,
+relative-point              Ratio,
+get-integer                 Get-Integer,
+get-ratio                   [46] Rt-Component-Target-Param,
+get-any                     [45] Get-Any
+}
+Current-Point-Spec-Param ::= CHOICE    {
+current-point-spec          Current-Point-Spec,
+current-point-spec-macro    [3] Current-Point-Spec-Macro
+}
+Current-Point-Spec-Macro ::= SEQUENCE    {
+macro-def-id                Macro-Def-ID,
+current-point-spec          Current-Point-Spec OPTIONAL
+}
+Current-Point-Spec ::= CHOICE    {
+point                      Point,
+relative-point              Ratio,
+original-point-factor       [1] Ratio,
+current-point-factor        [2] Ratio,
+get-integer                 [47] Get-Integer,
+get-ratio                   [46] Rt-Component-Target-Param,
+get-any                     [45] Get-Any
+}
+Initial-Point-Spec-Param ::= CHOICE    {
+initial-point-spec          Point-Spec,
+initial-point-spec-macro    [1] Initial-Point-Spec-Macro
+}
+Initial-Point-Spec-Macro ::= SEQUENCE    {
+macro-def-id                Macro-Def-ID,
+initial-point-spec          Point-Spec OPTIONAL
+}
+Terminal-Point-Spec-Param ::= CHOICE    {
+terminal-point-spec         Point-Spec,
+terminal-point-spec-macro    [1] Terminal-Point-Spec-Macro
+}
+Terminal-Point-Spec-Macro ::= SEQUENCE    {
+macro-def-id                Macro-Def-ID,
+terminal-point-spec         Point-Spec OPTIONAL
+}
+Channel-Perceptability ::= ENUMERATED    {
+on (1),
+off (2)
+}
+
+```
+
+```
+
+Channel-Availability-Status ::= ENUMERATED    {
+available (1),
+not-available (2)
+}
+Modifiability ::= ENUMERATED    {
+modifiable (1),
+not-modifiable (2)
+}
+Selectability ::= ENUMERATED    {
+selectable (1),
+not-selectable (2)
+}
+Modification-Status ::= ENUMERATED    {
+modified (1),
+not-modified (2),
+modifying (3)
+}
+Selection-Status ::= ENUMERATED {
+selected (1),
+not-selected (2)
+}
+Interaction-Status ::= CHOICE      {
+selection-status           Selection-Status,
+modification-status       [0] Modification-Status
+}
+Interaction-Type ::= ENUMERATED    {
+selection (1),
+modification (2)
+}
+Interaction-Type-Macro ::= SEQUENCE    {
+macro-def-id              Macro-Def-ID,
+interaction-type           Interaction-Type OPTIONAL
+}
+Interaction-Type-Param ::= CHOICE      {
+interaction-type           Interaction-Type,
+interaction-type-macro     Interaction-Type-Macro
+}
+Stream-Identification ::= CHOICE      {
+stream-id                 SEQUENCE OF INTEGER,
+all-streams               INTEGER { all-streams (1)}
+}
+Stream-Identification-Macro ::= SEQUENCE    {
+macro-def-id              Macro-Def-ID,
+stream-identification     Stream-Identification OPTIONAL
+}
+Stream-Identification-Param ::= CHOICE      {
+stream-identification     Stream-Identification,
+stream-identification-macro [0] Stream-Identification-Macro
+}
+Stream-Chosen-State ::= ENUMERATED    {
+chosen (1),
+not-chosen (2),
+partially-chosen (3)
+}
+PCV ::= CHOICE                      {
+integer                   INTEGER,
+min-avr                  [0] INTEGER { min-avr (0)},
+max-avr                  [1] INTEGER { max-avr (255)}
+}
+CV ::= CHOICE                       {
+integer                   INTEGER,
+min-avr                  [0] INTEGER { min-avr (0)},
+max-avr                  [1] INTEGER { max-avr (255)}
+}
+OV ::= CHOICE                       {
+integer                   INTEGER,
+min-avr                  [0] INTEGER { min-avr (0)},
+max-avr                  [1] INTEGER { max-avr (255)}
+}
+
+```
+
+```
+
+Point-Type-Param ::= ENUMERATED      {
+absolute (1),
+relative (2)
+}
+Spatial-Control-Macro ::= SEQUENCE    {
+macro-def-id           Macro-Def-ID,
+spatial-control         Spatial-Control OPTIONAL
+}
+Spatial-Control-Param ::= CHOICE     {
+spatial-control         Spatial-Control,
+spatial-control-macro   Spatial-Control-Macro
+}
+Expected-Axis-Result-Param ::= ENUMERATED    {
+x (1),
+y (2),
+z (3),
+xyz (4)
+}
+User-Spatial-Control ::= ENUMERATED      {
+allowed (1),
+not-allowed (2)
+}
+Spatial-Control ::= ENUMERATED   {
+moving (1),
+resizing (2),
+scaling (3),
+scrolling (4)
+}
+GSF ::= SEQUENCE                {
+x-gf           GF OPTIONAL,
+y-gf           [0] GF OPTIONAL,
+z-gf           [1] GF OPTIONAL
+}
+OVS-Proj-Strategy ::= ENUMERATED    {
+fixed (1),
+calculated (2)
+}
+Resizing-Strategy ::= ENUMERATED    {
+fixed (1),
+minimum (2),
+grows-only (3)
+}
+Aspect-Ratio ::= ENUMERATED        {
+preserved (1),
+not-preserved (2)
+}
+Expected-PVD-Result ::= ENUMERATED    {
+initial-temporal-position (1),
+terminal-temporal-position (2),
+duration (3)
+}
+Expected-PVD-Result-Macro ::= SEQUENCE    {
+macro-def-id           Macro-Def-ID,
+expected-pvd-result     Expected-PVD-Result OPTIONAL
+}
+Expected-PVD-Result-Param ::= CHOICE     {
+expected-pvd-result     Expected-PVD-Result,
+expected-pvd-result-macro Expected-PVD-Result-Macro
+}
+Expected-OVD-Result ::= ENUMERATED      {
+initial-temporal-position (1),
+terminal-temporal-position (2),
+duration (3)
+}
+Expected-OVD-Result-Macro ::= SEQUENCE    {
+macro-def-id           Macro-Def-ID,
+expected-ovd-result     Expected-OVD-Result OPTIONAL
+}
+
+```
+
+```
+
+Expected-OVD-Result-Param ::= CHOICE      {
+expected-ovd-result          Expected-OVD-Result,
+expected-ovd-result-macro    Expected-OVD-Result-Macro
+}
+Temporal-Termination ::= ENUMERATED      {
+freeze (1),
+stop (2)
+}
+OD ::= CHOICE                      {
+integer                      INTEGER,
+infinite                     [0] INTEGER { infinite (1)}
+}
+Presentation-Priority ::= CHOICE      {
+generic-integer              Generic-Integer,
+up-priority                  [1] INTEGER { up-priority (1)},
+down-priority                [0] INTEGER { down-priority (2)}
+}
+RPS-Assignment ::= CHOICE           {
+channel-reference            Channel-Reference,
+evaluated-reference          [0] Evaluated-Reference,
+prps                        INTEGER { prps (1)}
+}
+Ancestor ::= CHOICE                 {
+integer                      [4] INTEGER,
+root                        [5] INTEGER { root (1)}
+}
+EmptyChild ::= CHOICE               {
+integer                      [1] INTEGER,
+last                        [2] INTEGER { last (1)}
+}
+Child ::= CHOICE                    {
+generic-integer              [6] Generic-Integer,
+last                        INTEGER { last (1)},
+random                      [0] INTEGER { random (2)}
+}
+Navigation-Command ::= CHOICE      {
+child                       Child,
+emptychild                  EmptyChild,
+sibling                     [3] INTEGER,
+ancestor                    Ancestor
+}
+Navigation-Command-Macro ::= SEQUENCE  {
+macro-def-id                Macro-Def-ID,
+navigation-command          Navigation-Command OPTIONAL
+}
+Navigation-Command-Param ::= CHOICE   {
+navigation-command          Navigation-Command,
+navigation-command-macro    Navigation-Command-Macro
+}
+Termination-Status ::= ENUMERATED    {
+terminated (1),
+not-terminated (2)
+}
+Running-Status ::= ENUMERATED      {
+running (1),
+not-running (2)
+}
+Rt-Availability-Status ::= ENUMERATED  {
+available (1),
+not-available (2)
+}
+Activation-Status ::= ENUMERATED      {
+active (1),
+inactive (2)
+}
+
+```
+
+```
+
+Preparation-Status ::= ENUMERATED      {
+ready (1),
+not-ready (2)
+}
+Cat-Ext-Attribute-Macro ::= SEQUENCE    {
+macro-def-id                Macro-Def-ID,
+cat-ext-attribute            Cat-Ext-Attribute OPTIONAL
+}
+Cat-Ext-Attribute-Param ::= CHOICE      {
+cat-ext-attribute            Cat-Ext-Attribute,
+cat-ext-attribute-macro      [0] Cat-Ext-Attribute-Macro
+}
+Update-Command ::= ENUMERATED          {
+add (1),
+remove (2),
+replace (3)
+}
+Comparison-Value-Constant ::= CHOICE    {
+preparation-status           Preparation-Status,
+activation-status             [0] Activation-Status,
+rt-availability-status        [1] Rt-Availability-Status,
+running-status                [2] Running-Status,
+termination-status           [3] Termination-Status,
+prps                          INTEGER { prps (1) },
+infinite                      [4] INTEGER { infinite (2) },
+temporal-termination         [5] Temporal-Termination,
+aspect-ratio                  [6] Aspect-Ratio,
+resizing-strategy              [7] Resizing-Strategy,
+ovs-proj-strategy              [8] OVS-Proj-Strategy,
+user-spatial-control          [9] User-Spatial-Control,
+stream-chosen-state           [10] Stream-Chosen-State,
+selection-status              [11] Selection-Status,
+modification-status           [12] Modification-Status,
+channel-availability-status    [13] Channel-Availability-Status,
+channel-perceptability        [14] Channel-Perceptability
+}
+END
+
+Action Class
+-- Copyright statement:
+-- -----
+-- (c) International organization for Standardization 1996.
+-- Permission to copy in any form is granted for use with conforming MHEG Engines and applications
+-- as defined in ITU-T Recommendation T.171 provided this notice is included in all copies.
+--
+
+ISOMHEG-ac {joint-iso-itu-t(2) mheg(19) version(1) action-class(1)}
+DEFINITIONS
+    IMPLICIT TAGS
+    ::= BEGIN
+
+EXPORTS
+    Action-Object,
+    Action-Class;
+
+IMPORTS
+    Mh-object-Class,
+    Macro-Def-ID,
+    Mh-Reference FROM ISOMHEG-ud {joint-iso-itu-t(2) mheg(19) version(1) action-class(9)}
+    Elementary-Action FROM ISOMHEG-ea {joint-iso-itu-t(2) mheg(19) version(1) action-class(10)};
+
+Action-Class ::= SEQUENCE      {
+OBJECT IDENTIFIER DEFAULT {joint-iso-itu-t(2) mheg(19) version(1) action-class(1)},
+COMPONENTS OF Mh-object-Class,
+synchro-indicator-param      [1] Synchro-Indicator-Param,
+synchronised-action-list     SEQUENCE OF Synchronised-Action,
+...
+}
+
+```
+
+```
+
+Synchro-Indicator-Param ::= CHOICE      {
+synchro-indicator          Synchro-Indicator,
+synchro-indicator-macro    Synchro-Indicator-Macro
+}
+Synchro-Indicator-Macro ::= SEQUENCE    {
+macro-def-id                Macro-Def-ID,
+synchro-indicator          Synchro-Indicator OPTIONAL
+}
+Synchro-Indicator ::= ENUMERATED      {
+serial (1),
+parallel (2)
+}
+Synchronised-Action ::= CHOICE      {
+elementary-action          Elementary-Action,
+action-object              [60] Action-Object
+}
+Action-Object ::= CHOICE            {
+action-object-reference    [0] Mh-Reference,
+action-class                [1] Action-Class
+}
+END
+
+Link Class
+-- Copyright statement:
+-- -----
+-- (c) International organization for Standardization 1996.
+-- Permission to copy in any form is granted for use with conforming MHEG Engines and applications
+-- as defined in ITU-T Recommendation T.171 provided this notice is included in all copies.
+--
+
+ISOMHEG-lk {joint-iso-itu-t(2) mheg(19) version(1) link-class(2)}
+DEFINITIONS
+    IMPLICIT TAGS
+    ::= BEGIN
+
+EXPORTS
+    Link-Class,
+    Link-Effect;
+
+IMPORTS
+    Mh-object-Class,
+    Evaluated-Value,
+    Generic-Value,
+    Comparison-Value-Constant,
+    Macro-Def-ID FROM ISOMHEG-ud {joint-iso-itu-t(2) mheg(19) version(1) useful-definitions(9)}
+    Action-Object FROM ISOMHEG-ac {joint-iso-itu-t(2) mheg(19) version(1) action-class(1)};
+
+Link-Class ::= SEQUENCE      {
+OBJECT IDENTIFIER DEFAULT {joint-iso-itu-t(2) mheg(19) version(1) link-class(2)},
+COMPONENTS OF Mh-object-Class,
+link-condition                [1] Link-Condition,
+link-effect                    Link-Effect,
+...
+}
+
+Link-Condition ::= CHOICE    {
+trigger-condition              Trigger-Condition,
+logical-combination            [0] Logical-Combination
+}
+Trigger-Condition ::= SEQUENCE {
+source-value                    Evaluated-Value,
+previous-condition              Comparison-Operation OPTIONAL,
+current-condition                [0] Comparison-Operation
+}
+Constraint-Condition ::= SEQUENCE {
+source-value                    Evaluated-Value,
+current-condition                Comparison-Operation
+}
+
+```
+
+```
+
+Comparison-Operation ::= SEQUENCE    {
+comparison-operator      Comparison-Operator,
+comparison-value         Comparison-Value
+}
+Comparison-Value ::= CHOICE    {
+generic-value            Generic-Value,
+comparison-value-constant [50] Comparison-Value-Constant,
+unspecified              [51] INTEGER { unspecified (1) }
+}
+Comparison-Operator ::= ENUMERATED    {
+equal (1),
+not-equal (2),
+greater (3),
+greater-equal (4),
+less (5),
+less-equal (6)
+}
+Logical-Combination ::= SEQUENCE    {
+logical-operator          Logical-Operator,
+condition-list            SEQUENCE OF Condition
+}
+Logical-Operator ::= ENUMERATED    {
+and (1),
+or (2),
+xor (3),
+not (4)
+}
+Condition ::= CHOICE    {
+trigger-condition         Trigger-Condition,
+constraint-condition      [0] Constraint-Condition,
+logical-combination       [1] Logical-Combination
+}
+Link-Effect ::= SEQUENCE    {
+macro-parameter-resolution-list SEQUENCE OF Macro-Parameter-Resolution OPTIONAL,
+action-object             Action-Object
+}
+Macro-Parameter-Resolution ::= SEQUENCE    {
+macro-def-id              Macro-Def-ID,
+usage-value               Generic-Value
+}
+END
+
+Script Class
+-- Copyright statement:
+-- -----
+-- (c) International organization for Standardization 1996.
+-- Permission to copy in any form is granted for use with conforming MHEG Engines and applications
+-- as defined in ITU-T Recommendation T.171 provided this notice is included in all copies.
+--
+
+ISOMHEG-sc {joint-iso-itu-t(2) mheg(19) version(1) script-class(3)}
+DEFINITIONS
+    IMPLICIT TAGS
+    ::= BEGIN
+
+EXPORTS
+    Script-Class;
+
+IMPORTS
+    Model-Class,
+    Catalogued-Script-Classification,
+    Script-Hook,
+    Data-Reference FROM ISOMHEG-ud {joint-iso-itu-t(2) mheg(19) version(1) useful-definitions(9)}
+    InterchangedScript FROM ISOMHEG-sir {joint-iso-itu-t(2) mheg(19) version(1) script-interchange-representation(11)};
+
+```
+
+```
+
+Script-Class ::= SEQUENCE      {
+OBJECT IDENTIFIER DEFAULT {joint-iso-itu-t(2) mheg(19) version(1) script-class(3)},
+COMPONENTS OF Model-Class,
+script-classification          [1] Catalogued-Script-Classification OPTIONAL,
+script-hook                    [2] Script-Hook,
+script-data                    Script-Data,
+...
+}
+Script-Data ::= CHOICE        {
+script-inclusion                 Script-Inclusion,
+data-reference                 Data-Reference
+}
+Script-Inclusion ::= CHOICE    {
+bit-string                    BIT STRING,
+octet-string                  OCTET STRING,
+interchangedscript            InterchangedScript
+}
+END
+
+Content Class
+-- Copyright statement:
+-- -----
+-- (c) International organization for Standardization 1996.
+-- Permission to copy in any form is granted for use with conforming MHEG Engines and applications
+-- as defined in ITU-T Recommendation T.171 provided this notice is included in all copies.
+--
+
+ISOMHEG-ct {joint-iso-itu-t(2) mheg(19) version(1) content-class(4)}
+DEFINITIONS
+    IMPLICIT TAGS
+    ::= BEGIN
+
+EXPORTS
+    Content,
+    Content-Class;
+
+IMPORTS
+    OV,
+    Component-Class,
+    Cat-Content-Classification,
+    Content-Hook,
+    Data-Reference,
+    Generic-Value FROM ISOMHEG-ud {joint-iso-itu-t(2) mheg(19) version(1) content-class(9)};
+
+Content-Class ::= SEQUENCE    {
+OBJECT IDENTIFIER DEFAULT {joint-iso-itu-t(2) mheg(19) version(1) content-class(4)},
+COMPONENTS OF Content,
+...
+}
+
+Content ::= SEQUENCE          {
+COMPONENTS OF Component-Class,
+cat-content-classification    [2] Cat-Content-Classification OPTIONAL,
+content-hook                  [3] Content-Hook,
+ov                            [51] OV OPTIONAL,
+content-data                  Content-Data
+}
+
+Content-Data ::= CHOICE      {
+data-inclusion                 Data-Inclusion,
+data-reference                [50] Data-Reference
+}
+Data-Inclusion ::= CHOICE    {
+bit-string                   BIT STRING,
+octet-string                 OCTET STRING,
+generic-value                Generic-Value
+}
+END
+
+```
+
+Multiplexed Content Class
+
+-- Copyright statement:
+
+-- -----
+
+-- (c) International organization for Standardization 1996.
+
+-- Permission to copy in any form is granted for use with conforming MHEG Engines and applications
+
+-- as defined in ITU-T Recommendation T.171 provided this notice is included in all copies.
+
+--
+
+ISOMHEG-mu {joint-iso-itu-t(2) mheg(19) version(1) multiplexed-content-class(5)}
+
+DEFINITIONS
+
+IMPLICIT TAGS
+
+::= BEGIN
+
+EXPORTS
+
+Multiplexed-Content-Class;
+
+IMPORTS
+
+Content FROM ISOMHEG-ct {joint-iso-itu-t(2) mheg(19) version(1) content-class(4)}
+
+Cat-Content-Classification,
+
+Content-Hook FROM ISOMHEG-ud {joint-iso-itu-t(2) mheg(19) version(1) useful-definitions(9)};
+
+Multiplexed-Content-Class ::= SEQUENCE {
+
+OBJECT IDENTIFIER DEFAULT {joint-iso-itu-t(2) mheg(19) version(1) multiplexed-content-class(5)},
+
+COMPONENTS OF Content,
+
+multiplexed-stream-list SEQUENCE OF Multiplexed-Stream,
+
+...
+
+}
+
+Multiplexed-Stream ::= SEQUENCE {
+
+stream-id SEQUENCE OF INTEGER,
+
+cat-content-classification Cat-Content-Classification OPTIONAL,
+
+content-hook [0] Content-Hook OPTIONAL
+
+}
+
+END
+
+Composite Class
+
+-- Copyright statement:
+
+-- -----
+
+-- (c) International organization for Standardization 1996.
+
+-- Permission to copy in any form is granted for use with conforming MHEG Engines and applications
+
+-- as defined in ITU-T Recommendation T.171 provided this notice is included in all copies.
+
+--
+
+ISOMHEG-co {joint-iso-itu-t(2) mheg(19) version(1) composite-class(6)}
+
+DEFINITIONS
+
+IMPLICIT TAGS
+
+::= BEGIN
+
+EXPORTS
+
+Composite-Class;
+
+IMPORTS
+
+Component-Class,
+
+Mh-Reference FROM ISOMHEG-ud {joint-iso-itu-t(2) mheg(19) version(1) useful-definition(9)}
+
+Link-Effect,
+
+Link-Class FROM ISOMHEG-lk {joint-iso-itu-t(2) mheg(19) version(1) link-class(2)}
+
+Action-Object FROM ISOMHEG-ac {joint-iso-itu-t(2) mheg(19) version(1) action-class(1)}
+
+Content-Class FROM ISOMHEG-ct {joint-iso-itu-t(2) mheg(19) version(1) content-class(4)}
+
+Multiplexed-Content-Class FROM ISOMHEG-mu {joint-iso-itu-t(2) mheg(19) version(1) multiplexed-content-class(5)};
+
+Composite-Class ::= SEQUENCE {
+
+OBJECT IDENTIFIER DEFAULT {joint-iso-itu-t(2) mheg(19) version(1) composite-class(6)},
+
+COMPONENTS OF Component-Class,
+
+availability-start-up [14] Availability-Start-up OPTIONAL,
+
+availability-close-down Availability-Close-down OPTIONAL,
+
+rt-availability-start-up Rt-Availability-Start-up OPTIONAL,
+
+```
+
+rt-availability-close-down      [10] Link-Effect OPTIONAL,
+action-object-list             [11] SEQUENCE OF Action-Object OPTIONAL,
+link-object-list               [12] SEQUENCE OF Link-Object OPTIONAL,
+nb-of-elements                 [13] INTEGER,
+composition-element-list       SEQUENCE OF Composition-Element OPTIONAL,
+...
+}
+Availability-Start-up ::= CHOICE {
+link-effect                    Link-Effect,
+automatic-start-up-1           INTEGER { automatic-start-up-1 (1)},
+automatic-start-up-2           [0] INTEGER { automatic-start-up-2 (2)},
+automatic-start-up-3           [1] INTEGER { automatic-start-up-3 (3)},
+automatic-start-up-4           [2] INTEGER { automatic-start-up-4 (4)},
+automatic-start-up-5           [3] INTEGER { automatic-start-up-5 (5)}
+}
+Availability-Close-down ::= CHOICE {
+link-effect                    [4] Link-Effect,
+automatic-close-down-1         [5] INTEGER { automatic-close-down-1 (1)},
+automatic-close-down-2         [6] INTEGER { automatic-close-down-2 (2)},
+automatic-close-down-3         [7] INTEGER { automatic-close-down-3 (3)}
+}
+Rt-Availability-Start-up ::= CHOICE {
+link-effect                    [8] Link-Effect,
+automatic-rt-start-up          [9] INTEGER { automatic-rt-start-up (1)}
+}
+Link-Object ::= CHOICE {
+link-class                    Link-Class,
+link-object-reference          [0] Mh-Reference
+}
+Composition-Element ::= SEQUENCE {
+index                        INTEGER,
+associated-model              Associated-Model
+}
+Associated-Model ::= CHOICE {
+component-object-reference    Mh-Reference,
+content-class                 [3] Content-Class,
+multiplexed-content-class     [4] Multiplexed-Content-Class,
+composite-class               [5] Composite-Class,
+label                        [6] GraphicString
+}
+END
+
+```
+
+Container Class
+
+-- Copyright statement:
+
+-- (c) International organization for Standardization 1996.
+
+-- Permission to copy in any form is granted for use with conforming MHEG Engines and applications
+
+-- as defined in ITU-T Recommendation T.171 provided this notice is included in all copies.
+
+--
+
+ISOMHEG-cr {joint-iso-itu-t(2) mheg(19) version(1) container-class(7)}
+
+DEFINITIONS
+
+IMPLICIT TAGS
+
+::= BEGIN
+
+EXPORTS;
+
+IMPORTS
+
+Mh-object-Class,
+
+Mh-Reference FROM ISOMHEG-ud {joint-iso-itu-t(2) mheg(19) version(1) useful-definition(9)}
+
+Link-Effect,
+
+Link-Class FROM ISOMHEG-lk {joint-iso-itu-t(2) mheg(19) version(1) link-class(2)}
+
+Action-Class FROM ISOMHEG-ac {joint-iso-itu-t(2) mheg(19) version(1) action-class(1)}
+
+Script-Class FROM ISOMHEG-sc {joint-iso-itu-t(2) mheg(19) version(1) script-class(3)}
+
+Content-Class FROM ISOMHEG-ct {joint-iso-itu-t(2) mheg(19) version(1) content-class(4)}
+
+Multiplexed-Content-Class FROM ISOMHEG-mu {joint-iso-itu-t(2) mheg(19) version(1) multiplexed-content-class(5)}
+
+Composite-Class FROM ISOMHEG-co {joint-iso-itu-t(2) mheg(19) version(1) composite-class(6)}
+
+Descriptor-Class FROM ISOMHEG-de {joint-iso-itu-t(2) mheg(19) version(1) descriptor-class(8)};
+
+```
+
+Container-Class ::= SEQUENCE      {
+OBJECT IDENTIFIER DEFAULT {joint-iso-itu-t(2) mheg(19) version(1) container-class(7)},
+COMPONENTS OF Mh-object-Class,
+container-start-up                [10] Container-Start-up OPTIONAL,
+container-close-down              Container-Close-down OPTIONAL,
+container-element-list            [9] SEQUENCE OF Container-Element,
+...
+}
+
+Container-Start-up ::= CHOICE     {
+link-effect                       Link-Effect,
+automatic-container-start-up-1    INTEGER { automatic-container-start-up-1 (1)},
+automatic-container-start-up-2    [0] INTEGER { automatic-container-start-up-2 (2)},
+automatic-container-start-up-3    [1] INTEGER { automatic-container-start-up-3 (3)},
+automatic-container-start-up-4    [2] INTEGER { automatic-container-start-up-4 (4)},
+automatic-container-start-up-5    [3] INTEGER { automatic-container-start-up-5 (5)},
+automatic-container-start-up-6    [4] INTEGER { automatic-container-start-up-6 (6)},
+automatic-container-start-up-7    [5] INTEGER { automatic-container-start-up-7 (7)},
+automatic-container-start-up-8    [6] INTEGER { automatic-container-start-up-8 (8)}
+}
+
+Container-Close-down ::= CHOICE  {
+link-effect                       [7] Link-Effect,
+automatic-container-close-down    [8] INTEGER { automatic-container-close-down (1)}
+}
+
+Container-Element ::= CHOICE     {
+mh-reference                      Mh-Reference,
+action-class                     [3] Action-Class,
+link-class                       [4] Link-Class,
+script-class                     [5] Script-Class,
+content-class                    [6] Content-Class,
+multiplexed-content-class        [7] Multiplexed-Content-Class,
+composite-class                  [8] Composite-Class,
+container-class                  [9] Container-Class,
+descriptor-class                 [10] Descriptor-Class,
+...
+}
+END
+
+```
+
+Descriptor Class
+
+-- *Copyright statement:*
+
+-- -----
+
+-- *(c) International organization for Standardization 1996.*
+
+-- *Permission to copy in any form is granted for use with conforming MHEG Engines and applications*
+
+-- *as defined in ITU-T Recommendation T.171 provided this notice is included in all copies.*
+
+--
+
+ISOMHEG-de {joint-iso-itu-t(2) mheg(19) version(1) descriptor-class(8)}
+
+DEFINITIONS
+
+IMPLICIT TAGS
+
+::= BEGIN
+
+EXPORTS
+
+Descriptor-Class;
+
+IMPORTS
+
+Mh-object-Class,
+
+Mh-Reference,
+
+Catalogued-Style,
+
+Catalogued-Extended-Elementary-Action,
+
+Cat-Ext-Attribute,
+
+Class-ID,
+
+Catalogued-Script-Classification,
+
+Script-Hook,
+
+Cat-Content-Classification,
+
+Content-Hook,
+
+Catalogued-Media-Type,
+
+Value,
+
+Catalogued-Event FROM ISOMHEG-ud {joint-iso-itu-t(2) mheg(19) version(1) useful-definitions(9)};
+
+```
+
+Descriptor-Class ::= SEQUENCE      {
+OBJECT IDENTIFIER DEFAULT {joint-iso-itu-t(2) mheg(19) version(1) descriptor-class(8)},
+COMPONENTS OF Mh-object-Class,
+related-object-list                [1] SEQUENCE OF Related-Object OPTIONAL,
+other-descriptor-list              [2] SEQUENCE OF Mh-Reference OPTIONAL,
+readme                            GraphicString OPTIONAL,
+system-readable-material           System-Readable-Material OPTIONAL,
+channel-information-list           [3] SEQUENCE OF Channel-Information OPTIONAL,
+catalogued-style-information-list  [4] SEQUENCE OF Catalogued-Style OPTIONAL,
+cat-ext-elementary-action-info-list [5] SEQUENCE OF Catalogued-Extended-Elementary-Action OPTIONAL,
+cat-ext-attribute-info-list        [6] SEQUENCE OF Cat-Ext-Attribute OPTIONAL,
+...
+}
+Related-Object ::= SEQUENCE      {
+mh-reference                       Mh-Reference,
+object-information                 Object-Information OPTIONAL
+}
+Object-Information ::= SEQUENCE  {
+object-size                       INTEGER OPTIONAL,
+class-id                         Class-ID,
+class-specific-information         Class-Specific-Information OPTIONAL,
+offset                           INTEGER OPTIONAL
+}
+Class-Specific-Information ::= CHOICE  {
+script-class-information          Script-Class-Information,
+content-class-information        [0] Content-Class-Information,
+mux-content-class-info           [1] Mux-Content-Class-Info
+}
+Script-Class-Information ::= SEQUENCE  {
+script-classification             Catalogued-Script-Classification OPTIONAL,
+script-hook                      [0] Script-Hook OPTIONAL
+}
+Content-Class-Information ::= SEQUENCE  {
+cat-content-classification        Cat-Content-Classification OPTIONAL,
+content-hook                     [0] Content-Hook OPTIONAL,
+alternative-object-list           [1] SEQUENCE OF Alternative-Object OPTIONAL
+}
+Mux-Content-Class-Info ::= SEQUENCE  {
+content-class-information         Content-Class-Information,
+number-of-streams                INTEGER OPTIONAL,
+stream-information-list           SEQUENCE OF Stream-Information OPTIONAL
+}
+Stream-Information ::= SEQUENCE  {
+stream-id                        SEQUENCE OF INTEGER,
+content-class-information         Content-Class-Information
+}
+Alternative-Object ::= SEQUENCE  {
+content-object-ref               Mh-Reference,
+content-hook                    Content-Hook OPTIONAL,
+alternative-descriptor-object     [0] Mh-Reference OPTIONAL,
+alternative-readme               GraphicString OPTIONAL
+}
+System-Readable-Material ::= CHOICE  {
+bit-string                      BIT STRING,
+octet-string                    OCTET STRING
+}
+Channel-Information ::= SEQUENCE  {
+channel-id                      INTEGER,
+x-min                           INTEGER OPTIONAL,
+x-max                           [0] INTEGER OPTIONAL,
+y-min                           [1] INTEGER OPTIONAL,
+y-max                           [2] INTEGER OPTIONAL,
+z-min                           [3] INTEGER OPTIONAL,
+z-max                           [4] INTEGER OPTIONAL,
+x-resolution                    [5] INTEGER OPTIONAL,
+y-resolution                    [6] INTEGER OPTIONAL,
+
+```
+
+```
+
+z-resolution          [7] INTEGER OPTIONAL,
+t-resolution          [8] INTEGER OPTIONAL,
+f-min                 [9] INTEGER OPTIONAL,
+f-max                 [10] INTEGER OPTIONAL,
+audio-dynamic         [11] INTEGER OPTIONAL,
+channel-media-type-list SEQUENCE OF Catalogued-Media-Type OPTIONAL,
+event-mapping-list    [12] SEQUENCE OF Event-Mapping OPTIONAL
+}
+Event-Mapping ::= SEQUENCE {
+event                SEQUENCE OF Value,
+catalogued-event     Catalogued-Event OPTIONAL
+}
+END
+
+Elementary Action Class
+-- Copyright statement:
+-- -----
+-- (c) International organization for Standardization 1996.
+-- Permission to copy in any form is granted for use with conforming MHEG Engines and applications
+-- as defined in ITU-T Recommendation T.171 provided this notice is included in all copies.
+--
+
+ISOMHEG-ea {joint-iso-itu-t(2) mheg(19) version(1) elementary-actions(10)}
+DEFINITIONS
+    IMPLICIT TAGS
+    ::= BEGIN
+
+EXPORTS
+    Elementary-Action;
+
+IMPORTS
+    Generic-Integer-Param,
+    Macro-Def-ID,
+    Rt-Component-Reference,
+    Return-Target-Param,
+    Generic-Numeric-Param,
+    Generic-Value-Param,
+    Mh-Reference,
+    Target-Param,
+    Update-Command,
+    Catalogued-Extended-Elementary-Action,
+    Cat-Ext-Attribute-Param,
+    Mh-Target-Param,
+    Generic-Value,
+    Generic-List-Elt-ID-Param,
+    Rt-Target-Param,
+    Generic-Integer,
+    Rt-Script-Target-Param,
+    Socket-Target-Param,
+    Evaluated-Reference,
+    Rt-Component-Target-Param,
+    RPS-Assignment,
+    Generic-Ratio-Param,
+    Presentation-Priority,
+    Initial-Point-Spec-Param,
+    Terminal-Point-Spec-Param,
+    Current-Point-Spec-Param,
+    Temporal-Termination,
+    Point-Spec-Param,
+    GF-Param,
+    Point-Spec,
+    Aspect-Ratio,
+    Rt-Composite-Target-Param,
+    Resizing-Strategy,
+    OVS-Proj-Strategy,
+    Size-Spec-Param,
+    Spatial-Position-Spec-Param,
+    Spatial-Control-Param,
+    User-Spatial-Control,
+
+```
+
+Rt-Content-Target-Param,  
+ Channel-Target-Param,  
+ Rt-Mux-Target-Param,  
+ Interaction-Status,  
+ Interaction-Type-Param,  
+ Catalogued-Style,  
+ Rt-Content-Reference,  
+ Channel-Perceptability,  
+ Size,  
+ Evaluated-Integer,  
+ Evaluated-List,  
+ Rt-Component-Channel-Tg-Param,  
+ Generic-List-Param FROM ISOMHEG-ud {joint-iso-itu-t(2) mheg(19) version(1) useful-definitions(9)};
+
+```
+
+Delay ::= SEQUENCE {
+temporal-unit-ref-param      Temporal-Unit-Ref-Param,
+duration-param               Generic-Integer-Param
+}
+Temporal-Unit-Ref-Param ::= CHOICE {
+temporal-unit-ref            Temporal-Unit-Ref,
+temporal-unit-ref-macro      Temporal-Unit-Ref-Macro
+}
+Temporal-Unit-Ref-Macro ::= SEQUENCE {
+macro-def-id                 Macro-Def-ID,
+temporal-unit-ref            Temporal-Unit-Ref OPTIONAL
+}
+Temporal-Unit-Ref ::= CHOICE {
+rt-component-reference        Rt-Component-Reference,
+default-gf                    INTEGER { default-gf (1) }
+}
+Return ::= SEQUENCE {
+return-target-param-list      SEQUENCE OF Return-Target-Param,
+return-indicator-param        Generic-Numeric-Param,
+returned-generic-value-param-list SEQUENCE OF Generic-Value-Param OPTIONAL,
+content-object-ref-param-list [0] SEQUENCE OF Content-Object-Ref-Param OPTIONAL
+}
+Content-Object-Ref-Param ::= CHOICE {
+content-object-ref            Mh-Reference,
+content-object-ref-macro      [3] Content-Object-Ref-Macro
+}
+Content-Object-Ref-Macro ::= SEQUENCE {
+macro-def-id                  Macro-Def-ID,
+content-object-ref            Mh-Reference OPTIONAL
+}
+Set-Alias ::= SEQUENCE {
+target-param-list             SEQUENCE OF Target-Param,
+alias-spec-param-list         SEQUENCE OF Alias-Spec-Param
+}
+Alias-Spec-Param ::= CHOICE {
+alias-spec                    Alias-Spec,
+alias-spec-macro              [0] Alias-Spec-Macro
+}
+Alias-Spec-Macro ::= SEQUENCE {
+macro-def-id                  Macro-Def-ID,
+alias-spec                    Alias-Spec OPTIONAL
+}
+Alias-Spec ::= SEQUENCE {
+alias-list                    SEQUENCE OF GraphicString,
+update-command                Update-Command
+}
+Catalogued-Elementary-Action ::= SEQUENCE {
+target-param-list             SEQUENCE OF Target-Param,
+catalogued-extended-elementary-action-param Cat-Ext-Elementary-Action-Param,
+elementary-action-param-list SEQUENCE OF Generic-Value-Param OPTIONAL
+}
+Cat-Ext-Elementary-Action-Param ::= CHOICE {
+cat-ext-elementary-action      Catalogued-Extended-Elementary-Action,
+cat-ext-elementary-action-macro [0] Cat-Ext-Elementary-Action-Macro
+}
+
+```
+
+```
+
+Cat-Ext-Elementary-Action-Macro ::= SEQUENCE    {
+macro-def-id                      Macro-Def-ID,
+
+catalogued-extended-elementary-action    Catalogued-Extended-Elementary-Action OPTIONAL
+}
+Set-Catalogued-Attribute ::= SEQUENCE    {
+target-param-list                  SEQUENCE OF Target-Param,
+cat-ext-attribute-param            Cat-Ext-Attribute-Param,
+ext-attribute-value-param          Generic-Value-Param,
+transition-duration-param          Generic-Integer-Param OPTIONAL
+}
+Set-Data ::= SEQUENCE    {
+content-target-param-list          SEQUENCE OF Mh-Target-Param,
+substitution-indicator-param       Substitution-Indicator-Param,
+data-element-param-list            SEQUENCE OF Data-Element-Param OPTIONAL
+}
+Substitution-Indicator-Param ::= CHOICE    {
+substitution-indicator             Substitution-Indicator,
+substitution-indicator-macro       Substitution-Indicator-Macro
+}
+Substitution-Indicator-Macro ::= SEQUENCE    {
+macro-def-id                      Macro-Def-ID,
+substitution-indicator             Substitution-Indicator OPTIONAL
+}
+Substitution-Indicator ::= ENUMERATED    {
+substitution (1),
+no-substitution (2)
+}
+Data-Element-Param ::= CHOICE    {
+data-element                      Data-Element,
+data-element-macro                 [0] Data-Element-Macro
+}
+Data-Element-Macro ::= SEQUENCE    {
+macro-def-id                      Macro-Def-ID,
+data-element                      Data-Element OPTIONAL
+}
+Data-Element ::= SEQUENCE    {
+process-indicator                 Process-Indicator,
+generic-list-elt-id               SEQUENCE OF INTEGER OPTIONAL,
+generic-value                     [0] Generic-Value
+}
+Process-Indicator ::= ENUMERATED    {
+process (1),
+no-process (2)
+}
+Add ::= SEQUENCE    {
+content-target-param-list          SEQUENCE OF Mh-Target-Param,
+generic-list-elt-id-param          Generic-List-Elt-ID-Param OPTIONAL,
+generic-value-param               [1] Generic-Value-Param OPTIONAL
+}
+Subtract ::= SEQUENCE    {
+content-target-param-list          SEQUENCE OF Mh-Target-Param,
+generic-list-elt-id-param          Generic-List-Elt-ID-Param OPTIONAL,
+generic-value-param               [1] Generic-Value-Param OPTIONAL
+}
+Copy ::= SEQUENCE    {
+content-target-param              Mh-Target-Param,
+destination-param-list            SEQUENCE OF Mh-Target-Param
+}
+Run ::= SEQUENCE    {
+rt-target-param-list              SEQUENCE OF Rt-Target-Param,
+number-of-performances-param      [0] Number-Of-Performances-Param OPTIONAL
+}
+Number-Of-Performances-Param ::= CHOICE    {
+number-of-performances            Number-Of-Performances,
+number-of-performances-macro      [1] Number-Of-Performances-Macro
+}
+
+```
+
+```
+
+Number-Of-Performances-Macro ::= SEQUENCE    {
+macro-def-id                    Macro-Def-ID,
+number-of-performances          [0] Number-Of-Performances OPTIONAL
+}
+Number-Of-Performances ::= CHOICE    {
+generic-integer                  Generic-Integer,
+infinite                        [0] INTEGER { infinite (1)}
+}
+Set-Parameters ::= SEQUENCE    {
+rt-script-target-param-list      SEQUENCE OF Rt-Script-Target-Param,
+passing-param-list              SEQUENCE OF Passing-Param OPTIONAL
+}
+Passing-Param ::= CHOICE    {
+passing                          Passing,
+passing-macro                    Passing-Macro
+}
+Passing-Macro ::= SEQUENCE    {
+macro-def-id                    Macro-Def-ID,
+passing                          Passing OPTIONAL
+}
+Passing ::= CHOICE    {
+generic-value                    [1] Generic-Value,
+content-object-ref              [0] Mh-Reference
+}
+Plug ::= SEQUENCE    {
+socket-target-param-list        SEQUENCE OF Socket-Target-Param,
+plug-in-param                  Plug-In-Param
+}
+Plug-In-Param ::= CHOICE    {
+plug-in                          Plug-In,
+plug-in-macro                    [45] Plug-In-Macro
+}
+Plug-In-Macro ::= SEQUENCE    {
+macro-def-id                    Macro-Def-ID,
+plug-in                          Plug-In OPTIONAL
+}
+Plug-In ::= CHOICE    {
+rt-component-reference           Rt-Component-Reference,
+component-object-reference       Mh-Reference,
+label                           [3] GraphicString,
+evaluated-reference             [4] Evaluated-Reference
+}
+Set-RPS-Assignment ::= SEQUENCE    {
+rt-component-target-param-list  SEQUENCE OF Rt-Component-Target-Param,
+rps-assignment-param           RPS-Assignment-Param
+}
+RPS-Assignment-Param ::= CHOICE    {
+rps-assignment                  RPS-Assignment,
+rps-assignment-macro            RPS-Assignment-Macro
+}
+RPS-Assignment-Macro ::= SEQUENCE    {
+macro-def-id                    Macro-Def-ID,
+rps-assignment                  RPS-Assignment OPTIONAL
+}
+Set-Perceptability ::= SEQUENCE    {
+rt-component-target-param-list  SEQUENCE OF Rt-Component-Target-Param,
+perceptability-param            Generic-Ratio-Param,
+transition-duration-param       Generic-Integer-Param OPTIONAL
+}
+Set-Presentation-Priority ::= SEQUENCE    {
+rt-component-target-param-list  SEQUENCE OF Rt-Component-Target-Param,
+presentation-priority-param     Presentation-Priority-Param,
+transition-duration-param       Generic-Integer-Param OPTIONAL
+}
+Presentation-Priority-Param ::= CHOICE    {
+presentation-priority           Presentation-Priority,
+presentation-priority-macro     Presentation-Priority-Macro
+}
+
+```
+
+```
+
+Presentation-Priority-Macro ::= SEQUENCE    {
+macro-def-id                Macro-Def-ID,
+presentation-priority        Presentation-Priority OPTIONAL
+}
+Set-OVD ::= SEQUENCE                {
+rt-component-target-param-list    SEQUENCE OF Rt-Component-Target-Param,
+initial-point-spec-param          Initial-Point-Spec-Param,
+terminal-point-spec-param        Terminal-Point-Spec-Param
+}
+Set-CTP ::= SEQUENCE                {
+rt-component-target-param-list    SEQUENCE OF Rt-Component-Target-Param,
+current-point-spec-param        Current-Point-Spec-Param
+}
+Set-Temporal-Termination ::= SEQUENCE    {
+rt-target-param-list            SEQUENCE OF Rt-Target-Param,
+temporal-termination-param      Temporal-Termination-Param
+}
+Temporal-Termination-Param ::= CHOICE    {
+temporal-termination            Temporal-Termination,
+temporal-termination-macro      Temporal-Termination-Macro
+}
+Temporal-Termination-Macro ::= SEQUENCE    {
+macro-def-id                    Macro-Def-ID,
+temporal-termination            Temporal-Termination OPTIONAL
+}
+Set-PVD-Position ::= SEQUENCE    {
+socket-target-param-list        SEQUENCE OF Socket-Target-Param,
+temporal-position-param        Point-Spec-Param
+}
+Set-GTF ::= SEQUENCE                {
+rt-component-target-param-list    SEQUENCE OF Rt-Component-Target-Param,
+gtf-param                        GF-Param
+}
+Set-Timestones ::= SEQUENCE    {
+rt-component-target-param-list    SEQUENCE OF Rt-Component-Target-Param,
+timestone-spec-param-list        SEQUENCE OF Timestone-Spec-Param
+}
+Timestone-Spec-Param ::= CHOICE    {
+timestone-spec                  Timestone-Spec,
+timestone-spec-macro            [0] Timestone-Spec-Macro
+}
+Timestone-Spec-Macro ::= SEQUENCE    {
+macro-def-id                    Macro-Def-ID,
+timestone-spec                  Timestone-Spec OPTIONAL
+}
+Timestone-Spec ::= SEQUENCE    {
+timestone-list                  SEQUENCE OF Timestone,
+update-command                  Update-Command
+}
+Timestone ::= SEQUENCE            {
+timestone-id                    Generic-Integer,
+timestone-position              Point-Spec,
+number-of-repetitions           Number-Of-Repetitions
+}
+Number-Of-Repetitions ::= CHOICE    {
+generic-integer                  Generic-Integer,
+infinite                         [0] INTEGER { infinite (1) }
+}
+Set-Aspect-Ratio ::= SEQUENCE    {
+rt-component-target-param-list    SEQUENCE OF Rt-Component-Target-Param,
+aspect-ratio-param              Aspect-Ratio-Param
+}
+Aspect-Ratio-Param ::= CHOICE    {
+aspect-ratio                    Aspect-Ratio,
+aspect-ratio-macro              Aspect-Ratio-Macro
+}
+
+```
+
+```
+
+Aspect-Ratio-Macro ::= SEQUENCE {
+macro-def-id           Macro-Def-ID,
+aspect-ratio           Aspect-Ratio OPTIONAL
+}
+Set-Resizing-Strategy ::= SEQUENCE {
+rt-composite-target-param-list  SEQUENCE OF Rt-Composite-Target-Param,
+resizing-strategy-param        Resizing-Strategy-Param
+}
+Resizing-Strategy-Param ::= CHOICE {
+resizing-strategy           Resizing-Strategy,
+resizing-strategy-macro     Resizing-Strategy-Macro
+}
+Resizing-Strategy-Macro ::= SEQUENCE {
+macro-def-id           Macro-Def-ID,
+resizing-strategy       Resizing-Strategy OPTIONAL
+}
+Set-OVS-Proj-Strategy ::= SEQUENCE {
+rt-component-target-param-list  SEQUENCE OF Rt-Component-Target-Param,
+ovs-proj-strategy-param        OVS-Proj-Strategy-Param
+}
+OVS-Proj-Strategy-Param ::= CHOICE {
+ovs-proj-strategy           OVS-Proj-Strategy,
+ovs-proj-strategy-macro     OVS-Proj-Strategy-Macro
+}
+OVS-Proj-Strategy-Macro ::= SEQUENCE {
+macro-def-id           Macro-Def-ID,
+ovs-proj-strategy       OVS-Proj-Strategy OPTIONAL
+}
+Set-OVS ::= SEQUENCE {
+rt-component-target-param-list  SEQUENCE OF Rt-Component-Target-Param,
+size-spec-param                Size-Spec-Param,
+transition-duration-param      Generic-Integer-Param OPTIONAL
+}
+Set-OAP ::= SEQUENCE {
+rt-component-target-param-list  SEQUENCE OF Rt-Component-Target-Param,
+oap-param                      Spatial-Position-Spec-Param
+}
+Set-OVS-Position ::= SEQUENCE {
+rt-component-target-param-list  SEQUENCE OF Rt-Component-Target-Param,
+ovs-position-param             Spatial-Position-Spec-Param,
+transition-duration-param      Generic-Integer-Param OPTIONAL
+}
+Set-PAP ::= SEQUENCE {
+rt-component-target-param-list  SEQUENCE OF Rt-Component-Target-Param,
+pap-param                      Spatial-Position-Spec-Param
+}
+Set-PVS-Position ::= SEQUENCE {
+rt-component-target-param-list  SEQUENCE OF Rt-Component-Target-Param,
+pvs-position-param             Spatial-Position-Spec-Param,
+transition-duration-param      Generic-Integer-Param OPTIONAL
+}
+Set-GSF ::= SEQUENCE {
+rt-component-target-param-list  SEQUENCE OF Rt-Component-Target-Param,
+gsf-param                      GF-Param,
+transition-duration-param      Generic-Integer-Param OPTIONAL
+}
+Set-User-Spatial-Control ::= SEQUENCE {
+rt-component-target-param-list  SEQUENCE OF Rt-Component-Target-Param,
+spatial-control-param-list     SEQUENCE OF Spatial-Control-Param,
+user-spatial-control-param     User-Spatial-Control-Param
+}
+User-Spatial-Control-Param ::= CHOICE {
+user-spatial-control           User-Spatial-Control,
+user-spatial-control-macro     User-Spatial-Control-Macro
+}
+User-Spatial-Control-Macro ::= SEQUENCE {
+macro-def-id           Macro-Def-ID,
+user-spatial-control   User-Spatial-Control OPTIONAL
+}
+
+```
+
+```
+
+Set-CV ::= SEQUENCE {
+rt-content-target-param-list SEQUENCE OF Rt-Content-Target-Param,
+cv-param Current-Point-Spec-Param,
+transition-duration-param Generic-Integer-Param OPTIONAL
+}
+Set-GVF ::= SEQUENCE {
+gvf-target GVF-Target,
+gvf-param GF-Param,
+transition-duration-param Generic-Integer-Param OPTIONAL
+}
+GVF-Target ::= CHOICE {
+rt-composite-targets-param SEQUENCE OF Rt-Composite-Target-Param,
+channel-targets-param [0] SEQUENCE OF Channel-Target-Param
+}
+Set-Stream-Choice ::= SEQUENCE {
+rt-mux-target-param-list SEQUENCE OF Rt-Mux-Target-Param,
+stream-spec-param-list SEQUENCE OF Stream-Spec-Param OPTIONAL
+}
+Stream-Spec-Param ::= CHOICE {
+stream-spec Stream-Spec,
+stream-spec-macro [0] Stream-Spec-Macro
+}
+Stream-Spec-Macro ::= SEQUENCE {
+macro-def-id Macro-Def-ID,
+stream-spec Stream-Spec OPTIONAL
+}
+Stream-Spec ::= SEQUENCE {
+stream-id-reference-list SEQUENCE OF SEQUENCE OF INTEGER OPTIONAL,
+update-command Update-Command
+}
+Interaction-Status-Param ::= CHOICE {
+interaction-status Interaction-Status,
+interaction-status-macro Interaction-Status-Macro
+}
+Interaction-Status-Macro ::= SEQUENCE {
+macro-def-id Macro-Def-ID,
+interaction-status Interaction-Status OPTIONAL
+}
+Min-Interact-Required-Param ::= CHOICE {
+min-interact-required INTEGER,
+min-interact-required-macro Min-Interact-Required-Macro
+}
+Min-Interact-Required-Macro ::= SEQUENCE {
+macro-def-id Macro-Def-ID,
+min-interact-required INTEGER OPTIONAL
+}
+Max-Interact-Required-Param ::= CHOICE {
+max-interact-required INTEGER,
+max-interact-required-macro Max-Interact-Required-Macro
+}
+Max-Interact-Required-Macro ::= SEQUENCE {
+macro-def-id Macro-Def-ID,
+max-interact-required INTEGER OPTIONAL
+}
+Set-Interaction-Ability ::= SEQUENCE {
+rt-component-target-param-list SEQUENCE OF Rt-Component-Target-Param,
+interaction-type-param Interaction-Type-Param,
+min-interact-required-param Min-Interact-Required-Param,
+max-interact-required-param Max-Interact-Required-Param
+}
+Set-Interaction-Status ::= SEQUENCE {
+rt-component-target-param-list SEQUENCE OF Rt-Component-Target-Param,
+interaction-type-param Interaction-Type-Param,
+interaction-status-param Interaction-Status-Param
+}
+
+```
+
+```
+
+Set-Style ::= SEQUENCE      {
+rt-component-target-param-list  SEQUENCE OF Rt-Component-Target-Param,
+catalogued-style-param          Catalogued-Style-Param,
+additional-information-param    Generic-Value-Param OPTIONAL
+}
+Catalogued-Style-Param ::= CHOICE    {
+catalogued-style                Catalogued-Style,
+catalogued-style-macro          [0] Catalogued-Style-Macro
+}
+Catalogued-Style-Macro ::= SEQUENCE  {
+macro-def-id                    Macro-Def-ID,
+catalogued-style                Catalogued-Style OPTIONAL
+}
+Attach-Anchor ::= SEQUENCE      {
+rt-content-target-param-list    SEQUENCE OF Rt-Content-Target-Param,
+anchor-spec-param-list         SEQUENCE OF Anchor-Spec-Param
+}
+Anchor-Spec-Param ::= CHOICE      {
+anchor-spec                     Anchor-Spec,
+anchor-spec-macro               [0] Anchor-Spec-Macro
+}
+Anchor-Spec-Macro ::= SEQUENCE    {
+macro-def-id                    Macro-Def-ID,
+anchor-spec                     Anchor-Spec OPTIONAL
+}
+Anchor-Spec ::= SEQUENCE          {
+anchor-list                     SEQUENCE OF Anchor,
+update-command                 Update-Command
+}
+Anchor ::= CHOICE                 {
+rt-content-reference            Rt-Content-Reference,
+evaluated-reference             Evaluated-Reference
+}
+Set-Channel-Perceptability ::= SEQUENCE  {
+channel-target-param-list       SEQUENCE OF Channel-Target-Param,
+channel-perceptability-param    Channel-Perceptability-Param
+}
+Channel-Perceptability-Param ::= CHOICE  {
+channel-perceptability          Channel-Perceptability,
+channel-perceptability-macro    Channel-Perceptability-Macro
+}
+Channel-Perceptability-Macro ::= SEQUENCE  {
+macro-def-id                    Macro-Def-ID,
+channel-perceptability          Channel-Perceptability OPTIONAL
+}
+Set-CPS ::= SEQUENCE              {
+channel-target-param-list       SEQUENCE OF Channel-Target-Param,
+cps-initialisation-param        CPS-Initialisation-Param OPTIONAL
+}
+CPS-Initialisation-Param ::= CHOICE      {
+cps-initialisation              CPS-Initialisation,
+cps-initialisation-macro        [0] CPS-Initialisation-Macro
+}
+CPS-Initialisation-Macro ::= SEQUENCE    {
+macro-def-id                    Macro-Def-ID,
+cps-initialisation              CPS-Initialisation OPTIONAL
+}
+CPS-Initialisation ::= SEQUENCE          {
+cps-duration                    CPS-Duration OPTIONAL,
+cps-size                        [2] CPS-Size OPTIONAL
+}
+CPS-Duration ::= CHOICE               {
+integer                         INTEGER,
+infinite                        [0] INTEGER { infinite (1)},
+evaluated-integer               [1] Evaluated-Integer
+}
+
+```
+
+|                                    |                                            |
+|------------------------------------|--------------------------------------------|
+| CPS-Size ::= CHOICE                | {                                          |
+| size                               | Size,                                      |
+| evaluated-list                     | Evaluated-List                             |
+| }                                  |                                            |
+| Set-Event ::= SEQUENCE             | {                                          |
+| rt-component-channel-tg-param-list | SEQUENCE OF Rt-Component-Channel-Tg-Param, |
+| event-param                        | Generic-List-Param,                        |
+| event-data-param                   | Generic-Value-Param OPTIONAL               |
+| }                                  |                                            |
+| Elementary-Action ::= CHOICE       | {                                          |
+| set-event                          | Set-Event,                                 |
+| set-cps                            | [0] Set-CPS,                               |
+| set-channel-perceptability         | [1] Set-Channel-Perceptability,            |
+| new-channel                        | [59] SEQUENCE OF Channel-Target-Param,     |
+| delete-channel                     | [2] SEQUENCE OF Channel-Target-Param,      |
+| attach-anchor                      | [3] Attach-Anchor,                         |
+| get-style                          | Rt-Component-Target-Param,                 |
+| set-style                          | [4] Set-Style,                             |
+| set-interaction-ability            | [5] Set-Interaction-Ability,               |
+| set-interaction-status             | [6] Set-Interaction-Status,                |
+| set-stream-choice                  | [7] Set-Stream-Choice,                     |
+| set-cv                             | [8] Set-CV,                                |
+| set-gvf                            | [9] Set-GVF,                               |
+| set-aspect-ratio                   | [16] Set-Aspect-Ratio,                     |
+| set-resizing-strategy              | [17] Set-Resizing-Strategy,                |
+| set-ovs                            | [18] Set-OVS,                              |
+| set-oap                            | [19] Set-OAP,                              |
+| set-ovs-position                   | [20] Set-OVS-Position,                     |
+| set-pap                            | [21] Set-PAP,                              |
+| set-pvs-position                   | [22] Set-PVS-Position,                     |
+| set-gsf                            | [23] Set-GSF,                              |
+| set-user-spatial-control           | [24] Set-User-Spatial-Control,             |
+| set-ovd                            | [25] Set-OVD,                              |
+| set-ctp                            | [26] Set-CTP,                              |
+| set-temporal-termination           | [27] Set-Temporal-Termination,             |
+| set-pvd-position                   | [28] Set-PVD-Position,                     |
+| set-gtf                            | [29] Set-GTF,                              |
+| set-timestones                     | [30] Set-Timestones,                       |
+| set-perceptability                 | [31] Set-Perceptability,                   |
+| set-presentation-priority          | [32] Set-Presentation-Priority,            |
+| set-rps-assignment                 | [33] Set-RPS-Assignment,                   |
+| plug                               | [39] Plug,                                 |
+| set-parameters                     | [40] Set-Parameters,                       |
+| run                                | [41] Run,                                  |
+| stop                               | [42] SEQUENCE OF Rt-Target-Param,          |
+| new                                | [43] SEQUENCE OF Rt-Target-Param,          |
+| delete                             | [44] SEQUENCE OF Rt-Target-Param,          |
+| copy                               | [45] Copy,                                 |
+| set-data                           | [46] Set-Data,                             |
+| add                                | [47] Add,                                  |
+| subtract                           | [48] Subtract,                             |
+| link-abort                         | [49] SEQUENCE OF Mh-Target-Param,          |
+| activate                           | [50] SEQUENCE OF Mh-Target-Param,          |
+| deactivate                         | [51] SEQUENCE OF Mh-Target-Param,          |
+| prepare                            | [52] SEQUENCE OF Mh-Target-Param,          |
+| destroy                            | [53] SEQUENCE OF Mh-Target-Param,          |
+| catalogued-elementary-action       | [54] Catalogued-Elementary-Action,         |
+| set-catalogued-attribute           | [55] Set-Catalogued-Attribute,             |
+| set-alias                          | [56] Set-Alias,                            |
+| return                             | [57] Return,                               |
+| delay                              | [58] Delay,                                |
+| ...                                |                                            |
+| }                                  |                                            |
+| END                                |                                            |
+
+## Annex B
+
+### Examples of MHEG systems
+
+This Recommendation does not define the structure of the MHEG engine, nor how it handles the interchanged objects. In this annex, an example of the MHEG engine is shown.
+
+#### B.1 Example of an MHEG Engine
+
+Figure B.1 shows an implementation example of the MHEG engine and the relationship between MHEG engine, application, presentation services and access services. The MHEG engine is responsible for all processes within itself and the interworking with other modules. The MHEG engine may use the facilities provided by an operating system and system management services, which are not presented in this figure.
+
+![Figure B.1/T.171 – Example of MHEG engine architecture diagram.](a0e4d56066bf089079b9b4d24f666b01_img.jpg)
+
+The diagram illustrates the architecture of an MHEG engine and its interactions with external components. At the top, an 'Application module' box is connected to an 'Application interface' box. Below the interface is the 'MHEG engine' itself, which contains several internal modules: an 'Encoder' and a 'Decoder' at the top, an 'MHEG entities handler' in the center, and an 'Interpreter' at the bottom. Arrows show bidirectional communication between the 'Encoder' and 'Decoder', and between the 'MHEG entities handler' and the 'Interpreter'. The 'MHEG engine' is surrounded by four vertical bars representing interfaces: 'Presentation interface' on the left, 'User interface and presentation services' on the far left, 'Communication interface' on the right, and 'Communication management services' on the far right. Arrows indicate data flow between these interfaces and the internal components of the MHEG engine. The text 'T0826000-96/d056' is located at the bottom right of the diagram.
+
+Figure B.1/T.171 – Example of MHEG engine architecture diagram.
+
+Figure B.1/T.171 – Example of MHEG engine
+
+The MHEG engine may be composed of several modules as shown in Figure B.1.
+
+##### B.1.1 MHEG decoder
+
+This module converts MHEG objects encoded in ASN.1 to the internal format of the MHEG engine in order to handle MHEG objects.
+
+##### B.1.2 MHEG encoder
+
+This module formats internal MHEG objects into ASN.1 data so that they can be interchanged with another system. It is used when the MHEG engine sends an MHEG object to another system. This module may be optionally required in, for example, an authoring system.
+
+### B.1.3 MHEG entities handler
+
+This module handles MHEG objects, rt-objects, channels in their internal formats, allocates entities and controls the memory management.
+
+#### B.1.3.1 Reference resolution
+
+The MHEG entities handler may also resolve MHEG entities' references. The process of resolving a reference may be as shown in Figure B.2. This figure shows an example of the decision process to resolve references of MHEG entities.
+
+![Flowchart for Reference resolution (Figure B.2/T.171).](faa19fa09003307090f38a25ece74252_img.jpg)
+
+```
+graph TD
+    Start([A reference to be resolved]) --> D1{Access needed now?}
+    D1 -- Yes --> D2{Already resolved?}
+    D1 -- No --> D3{Already resolved?}
+    D2 -- Yes --> D4{Reference mechanism?}
+    D2 -- No --> D4
+    D3 -- Yes --> OK1[OK]
+    D3 -- No --> Forward[Forward reference, to be resolved later when needed]
+    D4 -- External --> AccessNow[Access now]
+    D4 -- Internal --> D5{Preparation path?}
+    D5 -- Yes --> AccessNow
+    D5 -- No --> Error[Error]
+    AccessNow --> OKError[OK or Error]
+```
+
+The flowchart illustrates the decision process for resolving a reference. It starts with 'A reference to be resolved'. A decision diamond asks 'Access needed now?'. If 'Yes', it proceeds to 'Already resolved?'. If 'Yes' here, it goes to 'Reference mechanism?'. If 'No', it also goes to 'Reference mechanism?'. If 'Reference mechanism?' is 'External', it goes to 'Access now'. If 'Internal', it goes to 'Preparation path?'. If 'Preparation path?' is 'Yes', it goes to 'Access now'. If 'No', it results in 'Error'. If 'Access needed now?' is 'No', it goes to 'Already resolved?'. If 'Yes' here, it results in 'OK'. If 'No', it results in 'Forward reference, to be resolved later when needed'. The 'Access now' box leads to 'OK or Error'.
+
+Flowchart for Reference resolution (Figure B.2/T.171).
+
+T0826010-96/d057
+
+**Figure B.2/T.171 – Reference resolution**
+
+When the MHEG engine needs to resolve a reference, two cases may arise as shown in Figure B.2:
+
+- 1) The entity does not need to be accessed immediately. For example, if there is an MHEG entity as a target of an action specified in the link effect of a certain link object and a Prepare action is targeted to this link object, it is not required to prepare the MHEG object at this moment. If the entity is not available for the MHEG engine, the reference to this entity may be left for later completion. This is called “forward reference”. If the entity is accessible for the MHEG engine at the time of request, no further processing is needed.
+- 2) The entity needs to be accessed immediately. For example, if an action object is referenced in a link object and a Prepare action is targeted to this link object, it is required also to prepare the referenced
+
+action object. In this case, the access, decoding and preparation of the entity is needed. Two cases apply as follows:
+
+- 3) If the referenced entity is not resolved yet, the MHEG engine tries to solve the reference. Two cases apply as follows:
+- 4) If the entity is referenced using an external identification, it is assumed that the MHEG engine recognises and resolves the external identification. The reference is considered as resolved.
+- 5) If the entity is referenced using an internal identification, the MHEG engine tries to resolve the reference. Two cases may apply:
+- 6) If a preparation path is available for the MHEG engine, the reference is considered as resolved. The preparation path is not defined by this Recommendation and may be dependent on the using application, the MHEG engine and the site practice. For example, a preparation path may indicate the whereabouts of the container which includes the required objects, or it may be represented in a form of a SQL request, a server address, a file specification, etc.
+- 7) If the MHEG engine is not able to resolve the reference, it is an error.
+- 8) If the referenced entity is considered as accessible for the MHEG engine, the MHEG engine tries to access the object using the communication services.
+
+If no entity is addressed while resolving the reference, no information is addressed.
+
+Depending on the context, this may generate an error condition. For example, if the target of the Prepare action is not accessible, the target remains not available to the MHEG engine. It is the MHEG engine's responsibility to signal this condition to the using application. For example, if a link condition is described on a non-existing MHEG entity, this condition cannot be satisfied now, but it is not an error. This link is not fired at this time; however, it may be fired later.
+
+#### **B.1.4 MHEG interpreter**
+
+This module processes MHEG entities according to this Recommendation. The MHEG interpreter may contain various processes, however; the following processes may be identified.
+
+##### **B.1.4.1 Preparation process**
+
+This process prepares any MHEG entities before their processing in the MHEG engine. For example, retrieving a content data of an audiovisual sequence from a disk may require so long time that it may be efficient to start loading it before it is needed.
+
+The preparation process may interpret the following elementary actions: Prepare action, Destroy action and Get Preparation Status action.
+
+##### **B.1.4.2 Creation process of rt-objects and channels**
+
+This process creates any rt-objects and channels.
+
+The creation process may interpret the following elementary actions: New action, Delete action, Get Rt-Availability Status action, New Channel action, Delete Channel action and Get Channel-Availability Status action.
+
+##### **B.1.4.3 Activation process**
+
+This process activates rt-components to be passed to a presentation process and rt-scripts to be passed to a script engine.
+
+This process may interpret the following elementary actions: Run action, Stop action and Get Running Status.
+
+##### **B.1.4.4 Script process**
+
+This process interprets a script data as described in a script object. Parameters may be exchanged in both ways between the MHEG engine and the script process.
+
+This process may interpret the following elementary action: Set Parameters action.
+
+#### **B.1.4.5 Presentation process**
+
+This process handles the presentation of rt-components. This process may interwork with the user interface and presentation services.
+
+This process may interpret all the elementary actions concerning the presentation. These actions may affect dynamically the rendition of rt-components and channel assignment, such as temporal behaviours, spatial behaviours, audible behaviours. And this process may interpret styles as specified by attributes.
+
+A using application may extend the presentation facilities to its specific renditions, e.g. colour, character fonts. This specific rendition may be interchanged within MHEG objects by using extensions and descriptions in descriptor objects. It is for the using application to ensure that the presentation process available for the MHEG engine is able to present MHEG objects with these specific renditions.
+
+#### **B.1.4.6 Interaction process**
+
+This process interacts with the user, and interworks with the GUI tools existing on the system. This process may handle the interaction behaviour, e.g. selection and modification.
+
+#### **B.1.4.7 Link process**
+
+This process evaluates in parallel all the conditions on MHEG entities described in the link conditions of the activated link objects, and processes the actions described in a link effect if the corresponding link condition is satisfied.
+
+#### **B.1.5 User interface and presentation services**
+
+This module is in charge of the multimedia presentation to the user and of the data acquisition from the user. The presentation module may be also used by the application module to present directly using application information.
+
+#### **B.1.6 Application module**
+
+It is the actual using application which handles, exchanges and manages MHEG entities. The using application handles MHEG entities through the interface provided by this Recommendation (by actions applied to each MHEG entity), possibly through the extensions using a proprietary catalogue. The using application may also need to access directly to the user interface.
+
+The following are possible commands and data facilities for the MHEG engine interface that may be used by the application module.
+
+- start the MHEG engine;
+- stop the MHEG engine;
+- supply MHEG entities or references to MHEG entities to the MHEG engine;
+- accept MHEG entities or references to MHEG entities from the MHEG engine;
+- start the processing of a specified object;
+- stop the processing of a specified object;
+- facilities equivalent to those provided by elementary actions;
+- facilities to access data within the MHEG engine, e.g. attributes, status values, engine statuses;
+- facilities to accept data from the MHEG engine, e.g. as the result of a Return action;
+- handle system management information indicating the result from the above facilities, i.e. errors.
+
+#### **B.1.7 Communication management module**
+
+This module handles the transmission of entities received or/and transmitted, and is in charge of the data access required for the MHEG engine. All data may be stored in local repositories (e.g. CD drive) or in remote repositories (e.g. database accessed through a network). This module is also in charge of the information transmission from the MHEG engine to the using application.
+
+The protocol to interchange is not defined in this Recommendation. During the interchanging process, some specific identification may be added to MHEG entities.
+
+The communication module may be also used by the application module to directly access pieces of software, scripts, external data and so on.
+
+## B.2 Application examples
+
+In this subclause, various usages and configurations of the multimedia/hypermedia systems, such as training applications, passive/interactive presentation of multimedia information, authoring applications, groupware applications, are shown.
+
+### B.2.1 Passive presentation system
+
+Figure B.3 shows a simple multimedia presentation system that is purely passive and only to receive and present MHEG entities. The MHEG entities are sent by a certain external process, and are received through the communication module and presented without any interaction with the user.
+
+![Figure B.3/T.171 – Configuration example of passive presentation system. The diagram shows a system architecture. On the left, a box labeled 'Access to objects and other external resources (e.g. external objects, external data scripts)' has two arrows pointing right: 'Receive MHEG entities' and 'Receive data'. These arrows point to a large box representing the system. Inside this box, at the top, is a shaded box labeled 'MHEG engine' containing three stacked boxes: 'MHEG interpreter', 'MHEG entities handler', and 'MHEG decoder'. Below the MHEG engine is a box labeled 'User interface and presentation services'. A double-headed vertical arrow connects the MHEG engine and the User interface box. Below the User interface box is another box labeled 'Operating system and system management services', connected to the User interface box by another double-headed vertical arrow. The entire system box is labeled with the reference 'T0826020-96/d058' at the bottom right.](4456970fc44aef8325e9e5c4efe2fcc9_img.jpg)
+
+```
+graph TD
+    External[Access to objects and other external resources  
+(e.g. external objects, external data scripts)]
+    subgraph System
+        subgraph MHEG_engine [MHEG engine]
+            MHEG_interpreter[MHEG interpreter]
+            MHEG_entities_handler[MHEG entities handler]
+            MHEG_decoder[MHEG decoder]
+        end
+        UI[User interface and presentation services]
+        OS[Operating system and system management services]
+        MHEG_engine <--> UI
+        UI <--> OS
+    end
+    External -- "Receive MHEG entities" --> MHEG_engine
+    External -- "Receive data" --> UI
+```
+
+T0826020-96/d058
+
+Figure B.3/T.171 – Configuration example of passive presentation system. The diagram shows a system architecture. On the left, a box labeled 'Access to objects and other external resources (e.g. external objects, external data scripts)' has two arrows pointing right: 'Receive MHEG entities' and 'Receive data'. These arrows point to a large box representing the system. Inside this box, at the top, is a shaded box labeled 'MHEG engine' containing three stacked boxes: 'MHEG interpreter', 'MHEG entities handler', and 'MHEG decoder'. Below the MHEG engine is a box labeled 'User interface and presentation services'. A double-headed vertical arrow connects the MHEG engine and the User interface box. Below the User interface box is another box labeled 'Operating system and system management services', connected to the User interface box by another double-headed vertical arrow. The entire system box is labeled with the reference 'T0826020-96/d058' at the bottom right.
+
+Figure B.3/T.171 – Configuration example of passive presentation system
+
+### B.2.2 Enhanced passive presentation system
+
+Figure B.4 shows a multimedia presentation system that is passive with some support of a using application for some specific operations. In this configuration, there is no interaction with the user. However, the MHEG engine may access MHEG entities under the control of the using application.
+
+![Architecture diagram of an enhanced passive presentation system.](d1ba2b47c5ebc10187d8e9089eacca4d_img.jpg)
+
+The diagram illustrates the architecture of an enhanced passive presentation system. It consists of several interconnected components:
+
+- External Resources:** A box on the left labeled "Access to objects and other external resources (e.g. external objects, external data, scripts)".
+- System Boundary:** A large light-gray box containing the core components of the presentation system.
+- Passive application:** A box at the top of the system boundary.
+- MHEG engine:** A central box within the system boundary containing three sub-components: "MHEG interpreter", "MHEG entities handler", and "MHEG decoder".
+- User interface and presentation services:** A box at the bottom of the system boundary.
+- Operating system and system management services:** A box at the very bottom, outside the system boundary.
+
+Interactions are shown with double-headed arrows:
+
+- Between the **External Resources** and the **System Boundary**:
+  - "Multimedia resources"
+  - "Ask for / receive MHEG entities"
+  - "Ask for / receive data"
+- Inside the **System Boundary**:
+  - Between **Passive application** and **MHEG engine**.
+  - Between **MHEG engine** and **User interface and presentation services**.
+  - Between **Passive application** and **User interface and presentation services**.
+- Between **User interface and presentation services** and **Operating system and system management services**.
+
+Architecture diagram of an enhanced passive presentation system.
+
+T0826030-96/d059
+
+Figure B.4/T.171 – Configuration example of enhanced passive presentation system
+
+### B.2.3 Interactive presentation system
+
+Figure B.5 shows a multimedia/hypermedia presentation system that is fully interactive with the user.
+
+![Configuration example of interactive presentation system diagram](9ec7afb8bd1d2648de277cd79293d4c1_img.jpg)
+
+The diagram illustrates the architecture of an interactive presentation system. It features a central system box containing several components, with external access and operating system services.
+
+- External Access:** A box on the left labeled "Access to objects and other external resources (e.g. external objects, external data, scripts)".
+- Central System:** A large box containing:
+  - Interactive application:** At the top.
+  - MHEG engine:** A shaded box containing three stacked components: "MHEG interpreter", "MHEG entities handler", and "MHEG decoder".
+  - User interface and presentation services:** Below the MHEG engine.
+- Operating System:** A box at the bottom labeled "Operating system and system management services".
+
+**Interactions (indicated by double-headed arrows):**
+
+- Between "Access to objects..." and the central system:
+  - "Multimedia resources" (from system to access).
+  - "Ask for / receive MHEG entities" (from access to system).
+  - "Ask for / receive data" (from access to system).
+- Between "Interactive application" and "MHEG engine".
+- Between "MHEG engine" and "User interface and presentation services".
+- Between "User interface and presentation services" and "Operating system and system management services".
+
+T0826040-96/d060
+
+Configuration example of interactive presentation system diagram
+
+**Figure B.5/T.171 – Configuration example of interactive presentation system**
+
+#### B.2.4 Interactive telematic system
+
+Figure B.6 shows an interactive telematic system in the educational environment given in Recommendation F.740. In this system, a student may react to the multimedia presentation and interact to the hypermedia. Depending on the interaction, MHEG entities are exchanged between the terminal and the server. Complex interaction or data process may be done by a using application which may use a script.
+
+The MHEG engine analyses the responses of the student, and it may request further MHEG entities, or content data required by the MHEG entities that are already received from the server. The formal responses of the student are returned to the server as some MHEG objects that may be received by the more sophisticated system used by a teacher.
+
+![Diagram of an interactive telematic system configuration showing the flow between external resources, a training application, an MHEG engine, user interface services, and operating system services.](f3f568cc57088117f1c4589f174d3dbf_img.jpg)
+
+```
+graph TD
+    subgraph System
+        TA[Training application (Script)] <--> ME[MHEG engine]
+        ME <--> UI[User interface and presentation services]
+        UI <--> OS[Operating system and system management services]
+        ME --- MEI[MHEG interpreter]
+        ME --- MEH[MHEG entities handler]
+        ME --- MDC[MHEG decoder]
+    end
+    ER[Access to objects and other external resources  
+(e.g. external objects, external data, scripts)]
+    ER -- Script --> TA
+    ER <-->|Ask for / receive MHEG entities| ME
+    ER <-->|Ask for / receive data| UI
+```
+
+The diagram illustrates the configuration of an interactive telematic system. It features a central system block containing three main components: a 'Training application (Script)' at the top, an 'MHEG engine' in the middle, and 'User interface and presentation services' at the bottom. The 'MHEG engine' is further detailed with three sub-components: 'MHEG interpreter', 'MHEG entities handler', and 'MHEG decoder'. Below the system block is the 'Operating system and system management services'. To the left of the system block is a separate box labeled 'Access to objects and other external resources (e.g. external objects, external data, scripts)'. Bidirectional arrows indicate the flow of data and control: between the Training application and the MHEG engine; between the MHEG engine and the User interface services; between the User interface services and the Operating system services; between the external resources and the Training application (labeled 'Script'); between the external resources and the MHEG engine (labeled 'Ask for / receive MHEG entities'); and between the external resources and the User interface services (labeled 'Ask for / receive data').
+
+Diagram of an interactive telematic system configuration showing the flow between external resources, a training application, an MHEG engine, user interface services, and operating system services.
+
+T0826050-96/d061
+
+Figure B.6/T.171 – Configuration example of interactive telematic service
+
+### B.2.5 Authoring system
+
+Figure B.7 shows an authoring system that creates MHEG objects and relies on several services of the MHEG engine for the dialogue with the author, such as the allocation of MHEG IDs to the objects and the exchange of MHEG objects.
+
+In this system, the MHEG engine as well as the application can access a specific module which is in charge of allocating unique IDs to each MHEG object at the authoring time.
+
+![Configuration example for authoring system diagram](35ddc8b19bd31dedba7ba2d696f43bd0_img.jpg)
+
+The diagram illustrates the configuration of an authoring system. It features a central box representing the system's core components, which includes an 'Authoring application' at the top, a 'MHEG engine' in the middle, and 'User interface and presentation services' at the bottom. The 'MHEG engine' is further detailed with four sub-components: 'MHEG interpreter', 'MHEG entities handler', 'MHEG decoder', and 'MHEG encoder'. To the left of this central box is a vertical rectangle labeled 'Access to objects and other external resources (e.g. external objects, external data, scripts)'. Below this rectangle is a box labeled 'Allocation of MHEG IDs'. The 'Access to objects...' box is connected to the central system box via four horizontal double-headed arrows, labeled from top to bottom: 'Multimedia resources', 'Ask for / receive MHEG IDs', 'Ask for / receive MHEG entities', and 'Ask for / receive data'. The 'Allocation of MHEG IDs' box is connected to the 'Access to objects...' box by a vertical double-headed arrow. The central system box is connected to the 'Operating system and system management services' box at the bottom by a vertical double-headed arrow. The entire central system box is enclosed in a larger light-gray rectangle.
+
+```
+graph TD
+    subgraph SystemBox [ ]
+        AA[Authoring application] <--> ME
+        subgraph MHEG_engine [MHEG engine]
+            MI[MHEG interpreter]
+            MEH[MHEG entities handler]
+            MD[MHEG decoder]
+            ME2[MHEG encoder]
+        end
+        ME <--> UI[User interface and presentation services]
+        UI <--> OS[Operating system and system management services]
+    end
+
+    AO[Access to objects and other external resources  
+(e.g. external objects, external data, scripts)]
+    AID[Allocation of MHEG IDs]
+
+    AO <-->|Multimedia resources| SystemBox
+    AO <-->|Ask for / receive MHEG IDs| SystemBox
+    AO <-->|Ask for / receive MHEG entities| SystemBox
+    AO <-->|Ask for / receive data| SystemBox
+
+    AID <--> AO
+```
+
+Configuration example for authoring system diagram
+
+T0826060-96/d062
+
+Figure B.7/T.171 – Configuration example for authoring system
+
+## B.2.6 Medical System
+
+A media system retrieving some client data, storing it back to the database and interworking between doctors through a network is a typical example of a multimedia/hypermedia information system and a cooperative work system.
+
+The following usages typically apply:
+
+- Database access and update (see Figure B.8): Through a local area network, doctors can access and update electrical medical chart database, in which medical information (e.g. text, image, sound, video) is stored. Doctors can see it on display and update the records as if they were working on paper documents. When the doctors input the request to consult a medical chart, a user application asks for the corresponding MHEG object to the MHEG engine. The MHEG engine gets the MHEG object from the database and presents it in cooperation with the communication manager and the MHEG decoder.
+- Cooperative work: Doctors and specialists in local and remote hospitals interchange medical charts as well as opinions on difficult cases. For this purpose, they need also a live video communication to establish a more friendly relationship among them.
+- Text input by a doctor: Figure B.9 shows the information flow corresponding to the text input by a doctor in a local hospital, which is presented on the display of another doctor located in a remote hospital.
+- Video input from a camera: Figure B.10 shows the information flow corresponding to the video input from a camera located in a remote hospital to the doctor's display in the local hospital.
+
+![Diagram illustrating the procedure of database access and update. The diagram shows a 'Using application' box on the left, a 'MHEG engine' box in the center, and a 'Database' box on the right. The 'MHEG engine' contains four sub-components: 'MHEG entities handler', 'MHEG interpreter', 'MHEG decoder', and 'MHEG encoder'. A 'Communication management module' is located below the 'MHEG engine'. A 'Local area network' is represented by an oval between the 'MHEG engine' and the 'Database'. Arrows indicate the flow of data: A (User request) from the 'Using application' to the 'User interface and presentation services'; B (Ask for MHEG object) from the 'User interface and presentation services' to the 'MHEG engine'; C (Ask for an access to MHEG object) from the 'MHEG engine' to the 'Communication management module'; D (Get the encoded MHEG object) from the 'Database' to the 'Local area network'; E (Interchange of encoded MHEG object) from the 'Local area network' to the 'Communication management module'; F (Decode MHEG object to internal format) from the 'Communication management module' to the 'MHEG decoder'; G (Interpret the object) from the 'MHEG decoder' to the 'MHEG interpreter'; H (Present the object) from the 'MHEG interpreter' to the 'User interface and presentation services'.](2ffdb0621c4918479cd1ac7a531b1b92_img.jpg)
+
+A User request  
+B Ask for MHEG object  
+C Ask for an access to MHEG object  
+D Get the encoded MHEG object  
+E Interchange of encoded MHEG object  
+F Decode MHEG object to internal format  
+G Interpret the object  
+H Present the object
+
+T0826070-96/d063
+
+Diagram illustrating the procedure of database access and update. The diagram shows a 'Using application' box on the left, a 'MHEG engine' box in the center, and a 'Database' box on the right. The 'MHEG engine' contains four sub-components: 'MHEG entities handler', 'MHEG interpreter', 'MHEG decoder', and 'MHEG encoder'. A 'Communication management module' is located below the 'MHEG engine'. A 'Local area network' is represented by an oval between the 'MHEG engine' and the 'Database'. Arrows indicate the flow of data: A (User request) from the 'Using application' to the 'User interface and presentation services'; B (Ask for MHEG object) from the 'User interface and presentation services' to the 'MHEG engine'; C (Ask for an access to MHEG object) from the 'MHEG engine' to the 'Communication management module'; D (Get the encoded MHEG object) from the 'Database' to the 'Local area network'; E (Interchange of encoded MHEG object) from the 'Local area network' to the 'Communication management module'; F (Decode MHEG object to internal format) from the 'Communication management module' to the 'MHEG decoder'; G (Interpret the object) from the 'MHEG decoder' to the 'MHEG interpreter'; H (Present the object) from the 'MHEG interpreter' to the 'User interface and presentation services'.
+
+Figure B.8/T.171 – Procedure of database access and update
+
+![Figure B.9/T.171: Information flow of text input. This diagram shows two identical systems connected via a Wide area network. Each system consists of a 'Using application' box, a 'User interface and presentation services' box, an 'MHEG engine' box, and a 'Communication management module' box. The 'MHEG engine' contains an 'MHEG entities handler' and an 'MHEG interpreter'. The 'Communication management module' contains an 'MHEG decoder' and an 'MHEG encoder'. Arrows indicate the flow of text input: A (Text input) from the application to the UI; B (Ask for modifying corresponding MHEG object) from the UI to the MHEG interpreter; C (Modify to internal format) from the MHEG interpreter to the MHEG entities handler; C' (Present the updated object) from the MHEG entities handler to the UI; D (Encode the MHEG object) from the MHEG entities handler to the MHEG encoder; E (Interchange of encoded MHEG object) from the MHEG encoder to the MHEG decoder; F (Decode MHEG object to internal format) from the MHEG decoder to the MHEG entities handler; G (Interpret the object) from the MHEG entities handler to the MHEG interpreter; H (Present the object) from the MHEG interpreter to the UI; H' (Indicate the modification to using application) from the UI to the application. The Wide area network connects the MHEG encoders and decoders of the two systems.](69a0bbfb9f60f00d25b9150cfa2204ab_img.jpg)
+
+Figure B.9/T.171: Information flow of text input. This diagram shows two identical systems connected via a Wide area network. Each system consists of a 'Using application' box, a 'User interface and presentation services' box, an 'MHEG engine' box, and a 'Communication management module' box. The 'MHEG engine' contains an 'MHEG entities handler' and an 'MHEG interpreter'. The 'Communication management module' contains an 'MHEG decoder' and an 'MHEG encoder'. Arrows indicate the flow of text input: A (Text input) from the application to the UI; B (Ask for modifying corresponding MHEG object) from the UI to the MHEG interpreter; C (Modify to internal format) from the MHEG interpreter to the MHEG entities handler; C' (Present the updated object) from the MHEG entities handler to the UI; D (Encode the MHEG object) from the MHEG entities handler to the MHEG encoder; E (Interchange of encoded MHEG object) from the MHEG encoder to the MHEG decoder; F (Decode MHEG object to internal format) from the MHEG decoder to the MHEG entities handler; G (Interpret the object) from the MHEG entities handler to the MHEG interpreter; H (Present the object) from the MHEG interpreter to the UI; H' (Indicate the modification to using application) from the UI to the application. The Wide area network connects the MHEG encoders and decoders of the two systems.
+
+T0826080-96/d064
+
+- A Text input
+- B Ask for modifying corresponding MHEG object
+- C Modify to internal format
+- C' Present the updated object
+- D Encode the MHEG object
+- E Interchange of encoded MHEG object
+- F Decode MHEG object to internal format
+- G Interpret the object
+- H Present the object
+- H' Indicate the modification to using application
+
+**Figure B.9/T.171 – Information flow of text input**
+
+![Figure B.10/T.171: Information flow of video input. This diagram shows two identical systems connected via a Wide area network. Each system consists of a 'Using application' box, a 'User interface and presentation services' box, an 'MHEG engine' box, and a 'Communication management module' box. The 'MHEG engine' contains an 'MHEG entities handler' and an 'MHEG interpreter'. The 'Communication management module' contains an 'MHEG decoder' and an 'MHEG encoder'. Arrows indicate the flow of video input: A (Video input) from the application to the UI; B (Modify to internal format) from the UI to the MHEG interpreter; C (Encode the MHEG object) from the MHEG interpreter to the MHEG entities handler; C' (Present the updated object) from the MHEG entities handler to the UI; D (Interchange of encoded MHEG object) from the MHEG entities handler to the MHEG encoder; E (Decode MHEG object to internal format) from the MHEG encoder to the MHEG decoder; F (Interpret the object) from the MHEG decoder to the MHEG interpreter; G (Present the object) from the MHEG interpreter to the UI. The Wide area network connects the MHEG encoders and decoders of the two systems.](9d4fac3c0fc4ca80bbf01b4eeb71f255_img.jpg)
+
+Figure B.10/T.171: Information flow of video input. This diagram shows two identical systems connected via a Wide area network. Each system consists of a 'Using application' box, a 'User interface and presentation services' box, an 'MHEG engine' box, and a 'Communication management module' box. The 'MHEG engine' contains an 'MHEG entities handler' and an 'MHEG interpreter'. The 'Communication management module' contains an 'MHEG decoder' and an 'MHEG encoder'. Arrows indicate the flow of video input: A (Video input) from the application to the UI; B (Modify to internal format) from the UI to the MHEG interpreter; C (Encode the MHEG object) from the MHEG interpreter to the MHEG entities handler; C' (Present the updated object) from the MHEG entities handler to the UI; D (Interchange of encoded MHEG object) from the MHEG entities handler to the MHEG encoder; E (Decode MHEG object to internal format) from the MHEG encoder to the MHEG decoder; F (Interpret the object) from the MHEG decoder to the MHEG interpreter; G (Present the object) from the MHEG interpreter to the UI. The Wide area network connects the MHEG encoders and decoders of the two systems.
+
+T0826090-96/d065
+
+- A Video input
+- B Modify to internal format
+- C Encode the MHEG object
+- D Interchange of encoded MHEG object
+- E Decode MHEG object to internal format
+- F Interpret the object
+- G Present the object
+
+**Figure B.10/T.171 – Information flow of video input**
+
+## Annex C
+
+### Interfaces to media Recommendations and Standards
+
+#### C.1 Example of still image content object
+
+This example shows a content object which contains an encoded still image as a content data. The detailed information of this content data is as follows and is shown in Figure C.1:
+
+- 256 (x) × 128 (y) pixels;
+- 150 dpi (x) × 150 dpi (y);
+- 256 grey levels (8 bits/pixel);
+- JPEG compression, baseline and hierarchical (4 levels).
+
+The content object may contain the following information:
+
+- 1) Content data: The corresponding encoded data.
+- 2) Data classification: Still picture.
+- 3) Content original perception: Not encoded. This information is to be retrieved from the hook and the content data.
+- 4) Content hook information:
+  - 5) Content encoding identification: ISO 10918 (JPEG) in the registered catalogue.
+  - 6) Content encoding description:
+    - 7) Byte 1: Luminance picture.
+    - 8) Bytes 2 and 3: y axis pixel density (150 dpi).
+    - 9) Bytes 4 and 5: x axis pixel density (150 dpi).
+    - 10) Byte 6: 8 bits/pixel.
+    - 11) Bytes 7 and 8: 256 (x) pixels.
+    - 12) Bytes 9 and 10: 128 (y) pixels.
+    - 13) Bytes 11 and 12: baseline and hierarchical.
+    - 14) Bytes 13 and 128: 128 bytes of comments, “casa mia”.
+
+![A black and white photograph of a two-story house with a gabled roof, multiple windows, and a small porch. The image is presented in a low-resolution, pixelated format, consistent with the 256x128 pixel specification mentioned in the text.](8c5d620091865579706e00b6df247461_img.jpg)
+
+A black and white photograph of a two-story house with a gabled roof, multiple windows, and a small porch. The image is presented in a low-resolution, pixelated format, consistent with the 256x128 pixel specification mentioned in the text.
+
+T0826100-96/d066
+
+Figure C.1/T.171 – Still picture
+
+## C.2 Example of audio content object
+
+This example shows a content object which contains audio information as a content data. The detailed information of this content data is as follows:
+
+- 1) Duration: 10 s.
+- 2) Sampling frequency: 48 kHz.
+- 3) Stereo mode.
+- 4) MPEG audio, layer 2.
+- 5) Rate: 256 kbit/s.
+- 6) Length: 352 000 bytes.
+- 7) Copyrighted by Deutsch Gramophon.
+- 8) “A baroque music piece from Haydn”.
+
+The content object may contain the following information:
+
+- 1) Content data: The corresponding encoded data is included in the content data.
+- 2) Data classification: Audio.
+- 3) Content original perception: Not encoded. This information is to be retrieved from the hook and the content data.
+- 4) Content hook information:
+  - 5) Content encoding identification: ISO 11172, MPEG-Audio and Annex E/T.101 in the registered catalogue.
+  - 6) Content encoding description:
+    - 7) Byte 1: Rate in kbit/s: 256.
+    - 8) Byte 2: JPEG-audio layer: 2.
+    - 9) Byte 3: Mode stereo.
+    - 10) Byte 4: Sampling frequency in kHz, 48.
+    - 11) Byte 5: Duration in seconds, 10.
+    - 12) Bytes 6 to 10: Length in bytes, 352 000.
+    - 13) Byte 11: Copyrighted, yes.
+    - 14) Bytes 12 and 128: 128 bytes of comments: “a baroque music piece from Haydn, copyrighted by Deutsch Gramophon”.
+
+## Annex D
+
+### Hypertext/Hypermedia Support
+
+#### D.1 Introduction
+
+This Recommendation provides a variety of ways to realise hypertext/hypermedia systems, i.e. hyperlinks. How to realise them completely depends on a certain implementation. The aim of this annex is to show several possible ways and provide some hints for implementers.
+
+The essential points to realise hypertext/hypermedia systems is how to provide so-called anchor and traverse mechanism. The anchor is a specific entity which indicates that some other entities are connected to a specific place or area of a certain entity. The place or area which an anchor is associated with is called a hotspot. A hotspot may be rendered in a specific way by a presentation system in order to indicate that an anchor is attached, e.g. words with underline, words with different colour. The traverse mechanism allows you to explore another entity presentation through an anchor which links two entities.
+
+## **D.2 Mechanism for Hypertext/Hypermedia**
+
+Hypertext/hypermedia mechanisms provided by this annex are categorised into 3 types by using:
+
+- transparent object;
+- anchor attached to an entity;
+- event handling.
+
+### **D.2.1 Transparent Object**
+
+Using a content object, a transparent object can be created and it can be used as an anchor. The typical method may be as follows:
+
+- 1) create a content object with some data, e.g. bitmap;
+- 2) create an rt-content from this model;
+- 3) set its perceptability attribute to 0;
+- 4) set its selectability as selectable;
+- 5) attach this rt-content to an MHEG object with certain positioning corresponding to the place where an anchor should be placed;
+- 6) create a link with the condition 'if this rt-content is selected' run other MHEG object, e.g. display another text.
+
+The transparent object can be considered as an anchor. Its hotspot can be set by some positioning elementary actions. And the traverse is specified by the associated link to the transparent rt-content object.
+
+The content data for this transparent object can be anything as far as the hook indicates what is inside. At least, the content should contain something which indicates the size of this object because this size is used as a size of the hotspot. If the perceptability is set to 0, the appearance of this object completely depends on the GUI, i.e. how to display a selectable object to a screen. It might be possible to set the perceptability not to 0 but around 0. In this case, the object can be perceived as semi-transparent so that a user can distinguish the hotspot. Positioning this rt-content to a certain MHEG object is something considerable. If the MHEG object changes its presentation, e.g. moving, resizing, change font, the attached rt-content should follow its change. As this annex defines the final form presentation, this might not be so big a problem in certain cases.
+
+### **D.2.2 Anchor attached to an Entity**
+
+Using the anchor defined by this Recommendation, an anchor mechanism can be achieved in a straightforward way. The typical way may be as follows:
+
+- 1) create an anchor;
+- 2) create an rt-object from this anchor;
+- 3) set its selectability as selectable;
+- 4) attach this rt-object (rt-anchor) to an MHEG object with the elementary action "attach anchor";
+- 5) create a link with the condition 'if this rt-content is selected' run other MHEG object, e.g. display another text.
+
+The anchor object contains anchor information depending on the content which the anchor is attached to. It is a kind of addressing scheme and tells where the hotspot for this anchor is. The hook can be used to indicate which addressing scheme is used in this anchor. Its hotspot is to be set by using a GUI interpreting this anchor information. Its presentation relies on the GUI, too.
+
+As there is no difference between an anchor and a content object but its presentation, any attributes for a content object can be used that may control some behaviours of an anchor.
+
+If an MHEG object to which the anchor is attached, changes its presentation, the anchor follows the position specified by the address information, because the GUI knows the changing of the presentation and can change the anchor position appropriately.
+
+### D.2.3 Event Handling
+
+An MHEG engine can receive some events from the system outside the engine. This event handling mechanism can be also used for realisation of hypermedia and hypertext. The typical way may be as follows:
+
+- 1) declare necessary events within a descriptor;
+- 2) create a content object corresponding to the descriptor;
+- 3) create an rt-content from this model;
+- 4) create a link with the condition, if some event happens, run other MHEG object, e.g. display another text.
+
+The event attribute and associated event data attribute can control the hyperlink mechanism.
+
+For example, in order to realise a bitmap depending on the position on which the user pointing device, e.g. a mouse, is clicked, the following is an example:
+
+- 1) declare “mouse click” event within a descriptor;
+- 2) create a content object containing a bitmap;
+- 3) create an rt-content from it;
+- 4) create a link which condition is “if the mouse click event happens on this rt-object, run a certain MHEG object depending on the position information stored in the event data attribute”.
+
+This is just an example. Since the event mechanism gives a general purpose method to synchronise and interact both between the MHEG engine and outer systems and between MHEG objects, beside them, many other possible ways can be realised.
+
+### D.2.4 Other Possibility
+
+A composite object can be made with a number of content objects. Each content object holds a piece of information or a unit of information which makes complete information together as aggregated as a composite. For example, a text object can be made as a composite object with a number of contents which have one word for each. In this case, each content object may be a hotspot if every content object is arranged appropriately and is set as selectable.
+
+This method might be difficult and complicated for a complex object.
+
+### D.2.5 Implementation and Cost
+
+In a real application, not only the above described methods may be useful, but also some combination of them. In addition, this annex provides means for even other realisations of hyperlink functionality. It is recommended to choose an appropriate method depending on the cost of realisation and system requirement.
+
+## D.3 An example of interrelationships between MHEG and WWW browser
+
+WWW stands for World Wide Web which is a hypermedia system and currently used widely in the Internet. It uses HyperText Markup Language (HTML), for hypertext markup, and Universal Resource Locator (URL), for identification of WWW objects. A WWW browser which is associated with a presentation system is responsible for handling any anchors that appear in the hypertext written in HTML.
+
+WWW uses an object identification technique called URL different from that used in this Recommendation which is the public identifier defined by ISO/IEC 9070. Therefore, there are two issues to be considered:
+
+- anchors in an HTML document which points to MHEG objects;
+- anchors in an MHEG object which points to HTML documents.
+
+In order to harmonise both issues, ISO/IEC 9070, public identifier, may be a solution.
+
+If public identification is used in this case, it looks like:
+
+Public ID = +IETF//<Protocol>://xxx.yyy.edu/.../zzz.mhg
+
+where zzz.mhg, MIME type associated; <Protocol>, e.g. T.176, ftp, http.
+
+IETF should ask the registration authority of ISO/IEC 9070 for registration of its identifier. And a MIME type for this Recommendation should be registered in IETF. It is an ITU-T responsibility to register T.176 protocol.
+
+And public identification decoder should be in the system, which is shared by both MHEG engine and WWW browsers. This decoder has the intelligence to resolve the reference. If the reference is a WWW object, then this information is passed to the WWW browser, and if the information is an MHEG object, it is passed to the MHEG engine. On the other hand, if the reference is an MHEG object, then this information is passed to the MHEG engine, and the MHEG engine passes the information for a GUI.
+
+## Annex E
+
+### Examples of spatial behaviours
+
+#### E.1 Example 1
+
+This example shows some snapshots of the presentation evolution with an rt-composite composed of two sockets in which two rt-contents are plugged in. They are displayed in the OS of their parent, i.e. their PRGS.
+
+##### E.1.1 Structure of rt-composite and initial settings
+
+Figure E.1 presents the rt-composite structure and the OSs of the rt-components.
+
+![Diagram showing the structure of an rt-composite and its two rt-contents.](9c0aa353d4de54327351c9326f198756_img.jpg)
+
+The diagram illustrates the structure of an rt-composite and its two rt-contents. At the top, a box labeled "rt-composite 'root'" contains two circles labeled "Socket 1" and "Socket 2". A line connects "Socket 1" to a large coordinate system labeled "rt-content 1: 'landscape'". This coordinate system has x and y axes ranging from 0 to 8, with tick marks at every integer. It displays a pixelated black and white image of a landscape with palm trees and a winding path. Another line connects "Socket 2" to a smaller coordinate system labeled "rt-content 2: 'ship'". This coordinate system has x and y axes ranging from 0 to 2, with tick marks at every integer. It displays a pixelated black and white image of a ship on water. The identifier "T0826110-96/d067" is located at the bottom right of the diagram.
+
+Diagram showing the structure of an rt-composite and its two rt-contents.
+
+Figure E.1/T.171 – Rt-composite and rt-content OS
+
+The OS of the rt-composite is composed of the following sockets. The initial settings of these three rt-objects are shown in Table E.1.
+
+Table E.1/T.171 – Initial settings of Example 1
+
+|                          | OS           | RPS<br>assignment | Resizing<br>strategy | OVS<br>projection<br>strategy | GSF | Presentation<br>priority |
+|--------------------------|--------------|-------------------|----------------------|-------------------------------|-----|--------------------------|
+| rt-composite “root”      | $8 \times 8$ | Channel           | Fixed                | Fixed                         | 1.0 | 0                        |
+| rt-content 1 “landscape” | $8 \times 8$ | Parent            | –                    | Calculated                    | 1.0 | 1                        |
+| rt-content 2 “ship”      | $2 \times 2$ | Parent            | –                    | Calculated                    | 1.0 | 0                        |
+
+E.1.2 Initial presentation in CGS
+
+Figure E.2 shows the mapping of PVSs of two rt-contents to their parent OS.
+
+No actions are applied for the rt-content 1. All default values are applied for setting OVS, OAP, OVS position, PAP and PVS position.
+
+For rt-content 2, the following actions are applied:
+
+- Set PAP (rt-content 2, x: 1, y: 0);
+- Set PVS Position (rt-content 2, x, 1, y: 4).
+
+No actions to defined OVS, OAP and OVS position are applied. All default values are applied for that.
+
+The rt-content 1 is overlaid on the rt-content 2 as it has a higher presentation priority.
+
+![Figure E.2/T.171: PVS setting of rt-contents to 'root' OS. The diagram shows an 8x8 coordinate system with x and y axes ranging from 0 to 8. Two content images are shown: 'rt-content 1' (a landscape with trees and a path) and 'rt-content 2' (a ship). Arrows indicate the mapping of PVS (Presentation View Set) for each content to the 'root' OS. Labels include: 'OS of "root" PVS of rt-content 1' pointing to the origin (0,0); 'PVS of rt-content 2' pointing to a box around the ship image; 'PAP of rt-content 2' pointing to the point (1,0); 'PVS position of rt-content 2' pointing to the point (1,4); 'PAP of rt-content 1' pointing to the point (2,1); and 'PVS position of rt-content 1' pointing to the point (2,0.5). The ship image is positioned such that its bottom-left corner is at (1,4). The landscape image is positioned such that its bottom-left corner is at (2,0.5).](ca29dcaf8247d96c4fef4ab76ed85076_img.jpg)
+
+Figure E.2/T.171: PVS setting of rt-contents to 'root' OS. The diagram shows an 8x8 coordinate system with x and y axes ranging from 0 to 8. Two content images are shown: 'rt-content 1' (a landscape with trees and a path) and 'rt-content 2' (a ship). Arrows indicate the mapping of PVS (Presentation View Set) for each content to the 'root' OS. Labels include: 'OS of "root" PVS of rt-content 1' pointing to the origin (0,0); 'PVS of rt-content 2' pointing to a box around the ship image; 'PAP of rt-content 2' pointing to the point (1,0); 'PVS position of rt-content 2' pointing to the point (1,4); 'PAP of rt-content 1' pointing to the point (2,1); and 'PVS position of rt-content 1' pointing to the point (2,0.5). The ship image is positioned such that its bottom-left corner is at (1,4). The landscape image is positioned such that its bottom-left corner is at (2,0.5).
+
+Figure E.2/T.171 – PVS setting of rt-contents to “root” OS
+
+Figure E.3 shows the OS mapping of the rt-composite to its CPS.
+
+Following actions are applied:
+
+- Set OVS (root, x: 4, y: 4);
+- Set OAP (root, x: 50%, y: 50%);
+- Set OVS Position (root, x: 2, y: 4);
+- Set PVS Position (root, x: 2, y: 4).
+
+A Set PAP action is not used. The default value for the PAP of root is used.
+
+![A 2D coordinate system diagram showing the mapping of the 'root' object to its CPS. The x and y axes both range from 0 to 10. A rectangular box labeled 'OS of "root"' is positioned with its bottom-left corner at (2, 2) and its top-right corner at (6, 8). Inside this box, a pixelated image of a ship is shown. A point labeled 'OVS and PVS of "root"' is located at the center of the box, at coordinates (4, 4). A point labeled 'OAP of "root"' is located at the center of the ship image, at coordinates (5, 6). A point labeled 'PAP of "root"' is located at the top-left corner of the box, at coordinates (2, 8). A point labeled 'OVS position of "root"' is located at the bottom-left corner of the box, at coordinates (2, 2). A point labeled 'PVS position of "root"' is located at the bottom-left corner of the box, at coordinates (2, 2). Arrows point from each of these labels to their respective points on the diagram. The text 'T0826130-96/d069' is located at the bottom right of the diagram.](5f0cd37cd04eb79e50c13875b337ad29_img.jpg)
+
+A 2D coordinate system diagram showing the mapping of the 'root' object to its CPS. The x and y axes both range from 0 to 10. A rectangular box labeled 'OS of "root"' is positioned with its bottom-left corner at (2, 2) and its top-right corner at (6, 8). Inside this box, a pixelated image of a ship is shown. A point labeled 'OVS and PVS of "root"' is located at the center of the box, at coordinates (4, 4). A point labeled 'OAP of "root"' is located at the center of the ship image, at coordinates (5, 6). A point labeled 'PAP of "root"' is located at the top-left corner of the box, at coordinates (2, 8). A point labeled 'OVS position of "root"' is located at the bottom-left corner of the box, at coordinates (2, 2). A point labeled 'PVS position of "root"' is located at the bottom-left corner of the box, at coordinates (2, 2). Arrows point from each of these labels to their respective points on the diagram. The text 'T0826130-96/d069' is located at the bottom right of the diagram.
+
+Figure E.3/T.171 – PVS setting of “root” to CPS
+
+### E.1.3 Scrolling
+
+Figure E.4 shows the effect of the following action targeted to the rt-composite “root”.
+
+- Set OVS Position (root, x: 3, y: 4).
+
+The effect of this action is to scroll the OVS of the rt-composite relatively to its OS. Other positions still remain as before.
+
+![A 2D coordinate system diagram illustrating the scrolling of the OVS (Object View Set) of the rt-composite 'root' relative to its OS (Object Set). The x and y axes both range from 0 to 10. A diagonal line with arrows indicates the scrolling direction. A rectangular box labeled 'OVS and PVS of "root"' is shown, containing a pixelated image of a landscape. Labels include 'OS of "root"' at the top, 'PAP of "root"' (Point of Appearance) at (2, 4), 'PVS position of "root"' (Point of Visibility) at (1, 2), 'OVS position of "root"' at (3, 4), and 'OAP of "root"' (Object Appearance Point) at (5, 7). A dotted vertical line is at x=9.](e47de8ad97151f5c6335b5e83c91a0f4_img.jpg)
+
+OS of "root"
+
+OVS and PVS of "root"
+
+OAP of "root"
+
+PAP of "root"
+
+PVS position of "root"
+
+OVS position of "root"
+
+T0826140-96/d070
+
+A 2D coordinate system diagram illustrating the scrolling of the OVS (Object View Set) of the rt-composite 'root' relative to its OS (Object Set). The x and y axes both range from 0 to 10. A diagonal line with arrows indicates the scrolling direction. A rectangular box labeled 'OVS and PVS of "root"' is shown, containing a pixelated image of a landscape. Labels include 'OS of "root"' at the top, 'PAP of "root"' (Point of Appearance) at (2, 4), 'PVS position of "root"' (Point of Visibility) at (1, 2), 'OVS position of "root"' at (3, 4), and 'OAP of "root"' (Object Appearance Point) at (5, 7). A dotted vertical line is at x=9.
+
+Figure E.4/T.171 – Scrolling of the rt-composite
+
+#### E.1.4 Scaling
+
+Figure E.5 shows the effect of the following actions targeted to the rt-composite “root”.
+
+- Set OAP (root, x: 0, y: 0);
+- Set OVS Position (root, x: 0, y: 0);
+- Set GSF (root, x: 0.5, y: 0.5).
+
+The PVS of the rt-composite “root” is not affected by the Set GSF action because the OVS projection strategy is set to “fixed”.
+
+![Figure E.5/T.171: Scaling of the rt-composite. A 2D coordinate system with x and y axes from 0 to 10. A shaded trapezoidal region represents the 'root' composite. The bottom-left corner is at (0,0), labeled 'PVS position of root'. The bottom-right corner is at (5,1), labeled 'OVS position of root'. The top-right corner is at (3.5,6), labeled 'OAP of root'. The top-left corner is at (1,5), labeled 'PVS of root'. A small scene with a ship and palm trees is shown within the trapezoid. A large arrow points from the origin (0,0) towards the center of the trapezoid. Labels 'PAP of root' and 'OVS position of root' also point to the bottom-left and bottom-right corners respectively. A small coordinate system is shown inside the trapezoid, with its origin at (1,1).](ed9a039f42c103268d8092afd5e58edb_img.jpg)
+
+T0826150-96/d071
+
+Figure E.5/T.171: Scaling of the rt-composite. A 2D coordinate system with x and y axes from 0 to 10. A shaded trapezoidal region represents the 'root' composite. The bottom-left corner is at (0,0), labeled 'PVS position of root'. The bottom-right corner is at (5,1), labeled 'OVS position of root'. The top-right corner is at (3.5,6), labeled 'OAP of root'. The top-left corner is at (1,5), labeled 'PVS of root'. A small scene with a ship and palm trees is shown within the trapezoid. A large arrow points from the origin (0,0) towards the center of the trapezoid. Labels 'PAP of root' and 'OVS position of root' also point to the bottom-left and bottom-right corners respectively. A small coordinate system is shown inside the trapezoid, with its origin at (1,1).
+
+Figure E.5/T.171 – Scaling of the rt-composite
+
+### E.1.5 Socket scaling
+
+Figure E.6 shows the effect of the following actions targeted to the rt-content 1.
+
+- Set GSF (rt-content 1, x: 2.0, y: 2.0);
+- Set PVS Position (rt-content 1, x: 3, y: 0).
+
+As the PAP is set to x: 1 and y: 0 previously, the PAP is not affected to the GSF change of the rt-content 1. If the PAP should remain relatively as specified before independent of the GSF change, the PAP should be specified relatively.
+
+![Figure E.6/T.171: A 2D coordinate system showing the scaling and moving of rt-content 1. The x and y axes range from 0 to 10. A rectangular box labeled 'PVS of "root"' is positioned with its bottom-left corner at (1, 1) and its top-right corner at (5, 5). Inside this box is a pixelated image of a sailboat on waves with palm trees in the background. An arrow labeled 'PAP of "root"' points to the point (1, 1) on the x-axis. Another arrow labeled 'PVS position of "root"' points to the origin (0, 0). The text 'T0826160-96/d072' is located at the bottom right of the plot area.](42ab2aee8612b8eb35a8e9597d6c1449_img.jpg)
+
+Figure E.6/T.171: A 2D coordinate system showing the scaling and moving of rt-content 1. The x and y axes range from 0 to 10. A rectangular box labeled 'PVS of "root"' is positioned with its bottom-left corner at (1, 1) and its top-right corner at (5, 5). Inside this box is a pixelated image of a sailboat on waves with palm trees in the background. An arrow labeled 'PAP of "root"' points to the point (1, 1) on the x-axis. Another arrow labeled 'PVS position of "root"' points to the origin (0, 0). The text 'T0826160-96/d072' is located at the bottom right of the plot area.
+
+Figure E.6/T.171 – Scaling and Moving of rt-content 1
+
+## E.2 Example 2
+
+This example shows a typical pull-down menu situation where a submenu is assigned directly to a channel. Such a feature enables the direct control of a submenu without constraining an element to be presented in the RPS of their parent.
+
+### E.2.1 Structure of rt-composite and initial settings
+
+Figure E.7 shows the composition structure of “menu”. Rt-content “file” and “option” compose a top menu. Rt-content “open”, “close” and “new” compose a submenu of “file”.
+
+![Diagram showing the hierarchical structure of a menu system. At the top is 'rt-composite "menu"' with three sockets: Socket 1, Socket 2, and Socket 3. Socket 1 connects to a box labeled 'FILE' with 'rt-content "file"' below it. Socket 3 connects to a box labeled 'OPTION' with 'rt-content "option"' below it. Socket 2 connects to 'rt-composite "submenu"' which has three sockets: Socket 2.1, Socket 2.2, and Socket 2.3. Socket 2.1 connects to a box labeled 'OPEN' with 'rt-content "open"' below it. Socket 2.2 connects to a box labeled 'CLOSE' with 'rt-content "close"' below it. Socket 2.3 connects to a box labeled 'NEW' with 'rt-content "new"' below it. The reference code 'T0826170-96/d073' is at the bottom right.](08246879b7e3340f5c7af67ca43e48ff_img.jpg)
+
+Diagram showing the hierarchical structure of a menu system. At the top is 'rt-composite "menu"' with three sockets: Socket 1, Socket 2, and Socket 3. Socket 1 connects to a box labeled 'FILE' with 'rt-content "file"' below it. Socket 3 connects to a box labeled 'OPTION' with 'rt-content "option"' below it. Socket 2 connects to 'rt-composite "submenu"' which has three sockets: Socket 2.1, Socket 2.2, and Socket 2.3. Socket 2.1 connects to a box labeled 'OPEN' with 'rt-content "open"' below it. Socket 2.2 connects to a box labeled 'CLOSE' with 'rt-content "close"' below it. Socket 2.3 connects to a box labeled 'NEW' with 'rt-content "new"' below it. The reference code 'T0826170-96/d073' is at the bottom right.
+
+**Figure E.7/T.171 – The structure of “menu”**
+
+### E.2.2 Initial presentation in CGS
+
+Figure E.8 shows the initial presentation of menu in a channel. Rt-composite “menu” and rt-composite “submenu” are directly presented in the channel.
+
+Rt-content “file” and “option” are projected to rt-composite “menu”. The PVS of the “menu” is positioned in the channel as shown in Figure E.8. Rt-content “open”, “close” and “new” are projected to rt-composite “submenu”. The PVS of the “submenu” is positioned in the channel as shown in Figure E.8.
+
+![Diagram showing the initial presentation of the menu in a channel. A vertical axis on the left is labeled with values 0 through 7. A horizontal axis at the bottom is labeled with values 0 through 6. Two boxes are shown: 'FILE' and 'OPTION' at a vertical level of 5.5, labeled 'PVS of "menu"'. Below them, at a vertical level of 3.5, are three stacked boxes: 'OPEN', 'CLOSE', and 'NEW', labeled 'PVS of "submenu"'. Arrows indicate projections: one from the origin (0,0) to the bottom-left corner of the 'FILE' box, another from the origin to the bottom-left corner of the 'NEW' box, and a third from the origin to the top-left corner of the 'FILE' box. Labels 'PAP' and 'PVS position' are placed next to the vertical axis at levels 5.5 and 4.5 respectively.](1da51f3c529c931159de791528434512_img.jpg)
+
+Diagram showing the initial presentation of the menu in a channel. A vertical axis on the left is labeled with values 0 through 7. A horizontal axis at the bottom is labeled with values 0 through 6. Two boxes are shown: 'FILE' and 'OPTION' at a vertical level of 5.5, labeled 'PVS of "menu"'. Below them, at a vertical level of 3.5, are three stacked boxes: 'OPEN', 'CLOSE', and 'NEW', labeled 'PVS of "submenu"'. Arrows indicate projections: one from the origin (0,0) to the bottom-left corner of the 'FILE' box, another from the origin to the bottom-left corner of the 'NEW' box, and a third from the origin to the top-left corner of the 'FILE' box. Labels 'PAP' and 'PVS position' are placed next to the vertical axis at levels 5.5 and 4.5 respectively.
+
+**Figure E.8/T.171 – Initial presentation of menu**
+
+**Table E.2/T.171 – Initial settings of Example 2**
+
+|                        | <b>RPS</b> | <b>Resizing strategy</b> |
+|------------------------|------------|--------------------------|
+| rt-composite “menu”    | CGS        | Minimum                  |
+| rt-content “file”      | Parent     | –                        |
+| rt-content “option”    | Parent     | –                        |
+| rt-composite “submenu” | CGS        | Minimum                  |
+| rt-composite “open”    | Parent     | –                        |
+| rt-composite “close”   | Parent     | –                        |
+| rt-composite “new”     | Parent     | –                        |
+
+## **Annex F**
+
+### **Summary of Object Identifiers**
+
+The object identifiers have the form {root arc1 arc2 arc3} where:
+
+- **root** = 2, joint-iso-itu-t standard.
+- **arc1** = 19, MHEG standard identification.
+- **arc2** = 1, version of the standard.
+- **arc3** = number of a class as defined in MH-Object class.
+
+**Table F.1/T.171 – Summary of object Identifier**
+
+| <b>ASN.1 module name</b> | <b>ASN.1 module identifier value</b> | <b>MHEG class identifier</b> | <b>Mnemonic</b> | <b>Class identified</b> |
+|--------------------------|--------------------------------------|------------------------------|-----------------|-------------------------|
+| ISOMHEG-mh               | None                                 | None                         | mh              | Mh-object               |
+| ISOMHEG-ac               | {2 19 1 1}                           | {2 19 1 1}                   | ac              | Action                  |
+| ISOMHEG-lk               | {2 19 1 2}                           | {2 19 1 2}                   | lk              | Link                    |
+| ISOMHEG-mo               | None                                 | None                         | mo              | Model                   |
+| ISOMHEG-sc               | {2 19 1 3}                           | {2 19 1 3}                   | sc              | Script                  |
+| ISOMHEG-cp               | None                                 | None                         | cp              | Component               |
+| ISOMHEG-ct               | {2 19 1 4}                           | {2 19 1 4}                   | ct              | Content                 |
+| ISOMHEG-mu               | {2 19 1 5}                           | {2 19 1 5}                   | mu              | Multiplexed Content     |
+| ISOMHEG-co               | {2 19 1 6}                           | {2 19 1 6}                   | co              | Composite               |
+| ISOMHEG-cr               | {2 19 1 7}                           | {2 19 1 7}                   | cr              | Container               |
+| ISOMHEG-de               | {2 19 1 8}                           | {2 19 1 8}                   | de              | Descriptor              |
+| ISOMHEG-ud               | {2 19 1 9}                           | None                         | ud              | Useful Definition       |
+| ISOMHEG-ea               | {2 19 1 10}                          | None                         | ea              | Elementary Action       |
+
+## Annex G
+
+### Index
+
+#### Index of the clauses
+
+|                                       |     |                                 |     |
+|---------------------------------------|-----|---------------------------------|-----|
+| Action-Class                          | 274 | Cat-Ext-Elementary-Action-Param | 283 |
+| Action-Object                         | 275 |                                 |     |
+| Activation-Status                     | 273 | Channel-Availability-Status     | 271 |
+| Add                                   | 284 |                                 |     |
+| Alias-Spec                            | 283 | Channel-Information             | 281 |
+| Alias-Spec-Macro                      | 283 |                                 |     |
+| Alias-Spec-Param                      | 283 | Channel-Perceptability          | 270 |
+| Alternative-Object                    | 281 |                                 |     |
+| Ancestor                              | 273 | Channel-Perceptability-Macro    | 289 |
+| Anchor                                | 289 |                                 |     |
+| Anchor-Spec                           | 289 | Channel-Perceptability-Param    | 289 |
+| Anchor-Spec-Macro                     | 289 |                                 |     |
+| Anchor-Spec-Param                     | 289 | Channel-Reference               | 261 |
+| Aspect-Ratio                          | 272 |                                 |     |
+| Aspect-Ratio-Macro                    | 287 | Channel-Target                  | 263 |
+| Aspect-Ratio-Param                    | 286 |                                 |     |
+| Associated-Model                      | 279 | Channel-Target-Macro            | 263 |
+| Attach-Anchor                         | 289 |                                 |     |
+| Availability-Close-down               | 279 | Channel-Target-Param            | 263 |
+| Availability-Start-up                 | 279 |                                 |     |
+| Catalogued-Content-Encoding           | 268 | Child                           | 273 |
+| Catalogued-Elementary-Action          | 283 |                                 |     |
+| Catalogued-Event                      | 268 | Class-ID                        | 258 |
+| Catalogued-Extended-Elementary-Action | 268 |                                 |     |
+| Catalogued-Media-Type                 | 268 | Class-Specific-Information      | 281 |
+| Catalogued-Script-Classification      | 268 |                                 |     |
+| Catalogued-Script-Encoding            | 268 | Comparison-Operation            | 276 |
+| Catalogued-Style                      | 268 |                                 |     |
+| Catalogued-Style-Macro                | 289 |                                 |     |
+| Catalogued-Style-Param                | 289 |                                 |     |
+| Cat-Content-Classification            | 268 |                                 |     |
+| Cat-Ext-Attribute                     | 268 |                                 |     |
+| Cat-Ext-Attribute-Macro               | 274 |                                 |     |
+| Cat-Ext-Attribute-Param               | 274 |                                 |     |
+| Cat-Ext-Elementary-Action-Macro       | 284 |                                 |     |
+
+|                             |     |     |                     |     |
+|-----------------------------|-----|-----|---------------------|-----|
+| Comparison-Operator         | 276 |     | Evaluated-Boolean   | 267 |
+| Comparison-Value            | 276 |     |                     |     |
+| Comparison-Value-Constant   |     | 274 |                     |     |
+| Component-Class             | 258 |     |                     |     |
+| Composite-Class             | 278 |     | Evaluated-Integer   | 267 |
+| Composition-Element         | 279 |     |                     |     |
+| Condition                   | 276 |     |                     |     |
+| Constraint-Condition        | 275 |     |                     |     |
+| Container-Class             | 280 |     |                     |     |
+| Container-Close-down        | 280 |     | Evaluated-List      | 268 |
+| Container-Element           | 280 |     |                     |     |
+| Container-Element-Reference |     | 259 |                     |     |
+| Container-Start-up          | 280 |     |                     |     |
+| Content                     | 277 |     | Evaluated-Numeric   | 267 |
+| Content-Class               | 277 |     |                     |     |
+| Content-Class-Information   |     | 281 |                     |     |
+| Content-Data                | 277 |     |                     |     |
+| Content-Hook                | 268 |     |                     |     |
+| Content-Object-Ref-Macro    |     | 283 | Evaluated-Ratio     | 267 |
+| Content-Object-Ref-Param    |     | 283 |                     |     |
+| Copy                        | 284 |     |                     |     |
+| CPS-Duration                | 289 |     |                     |     |
+| CPS-Initialisation          | 289 |     | Evaluated-Reference | 268 |
+| CPS-Initialisation-Macro    |     | 289 |                     |     |
+| CPS-Initialisation-Param    |     | 289 |                     |     |
+| CPS-Size                    | 290 |     |                     |     |
+| Current-Point-Spec          | 270 |     |                     |     |
+| Current-Point-Spec-Macro    |     | 270 | Evaluated-String    | 268 |
+| Current-Point-Spec-Param    |     | 270 |                     |     |
+| CV                          | 271 |     |                     |     |
+| Data-Element                | 284 |     |                     |     |
+| Data-Element-Macro          | 284 |     | Evaluated-Value     | 267 |
+| Data-Element-Param          | 284 |     |                     |     |
+| Data-Inclusion              | 277 |     |                     |     |
+| Data-Reference              | 259 |     |                     |     |
+| Delay                       | 283 |     |                     |     |
+| Description                 | 258 |     | Event-Mapping       | 282 |
+| Descriptor-Class            | 281 |     |                     |     |
+| Elementary-Action           | 290 |     |                     |     |
+| EmptyChild                  | 273 |     |                     |     |
+
+|                            |     |                                  |     |
+|----------------------------|-----|----------------------------------|-----|
+| Expected-Axis-Result-Param | 272 | Get-Interaction-Ability          | 265 |
+| Expected-OVD-Result        | 272 |                                  |     |
+| Expected-OVD-Result-Macro  | 272 |                                  |     |
+| Expected-OVD-Result-Param  | 273 |                                  |     |
+| Expected-PVD-Result        | 272 | Get-Interaction-Status           | 265 |
+| Expected-PVD-Result-Macro  | 272 |                                  |     |
+| Expected-PVD-Result-Param  | 272 |                                  |     |
+| External-ID                | 259 |                                  |     |
+| Generic-Boolean            | 264 |                                  |     |
+| Generic-Boolean-Macro      | 264 | Get-List                         | 267 |
+| Generic-Boolean-Param      | 263 |                                  |     |
+| Generic-Integer            | 264 |                                  |     |
+| Generic-Integer-Macro      | 264 |                                  |     |
+| Generic-Integer-Param      | 264 | Get-Max-Interact-Required        | 265 |
+| Generic-List               | 265 |                                  |     |
+| Generic-List-Elt-ID-Macro  | 265 |                                  |     |
+| Generic-List-Elt-ID-Param  | 265 |                                  |     |
+| Generic-List-Macro         | 265 |                                  |     |
+| Generic-List-Param         | 265 | Get-Min-Interact-Required        | 265 |
+| Generic-Numeric            | 264 |                                  |     |
+| Generic-Numeric-Macro      | 264 |                                  |     |
+| Generic-Numeric-Param      | 264 |                                  |     |
+| Generic-Ratio              | 264 | Get-Number-Of-Interacted-Sockets | 265 |
+| Generic-Ratio-Macro        | 264 |                                  |     |
+| Generic-Ratio-Param        | 264 |                                  |     |
+| Generic-Reference          | 265 |                                  |     |
+| Generic-Reference-Macro    | 265 |                                  |     |
+| Generic-Reference-Param    | 264 | Get-OAP                          | 266 |
+| Generic-String             | 264 |                                  |     |
+| Generic-String-Macro       | 264 |                                  |     |
+| Generic-String-Param       | 264 |                                  |     |
+| Generic-Value              | 263 | Get-OS                           | 266 |
+| Generic-Value-Macro        | 263 |                                  |     |
+| Generic-Value-Param        | 263 |                                  |     |
+| Get-Any                    | 267 |                                  |     |
+| Get-Catalogued-Attribute   | 266 | Get-OVD                          | 266 |
+| Get-Data                   | 266 |                                  |     |
+| Get-GSF                    | 265 |                                  |     |
+| Get-GVF                    | 265 |                                  |     |
+| Get-Integer                | 266 |                                  |     |
+
+|                             |     |                             |     |
+|-----------------------------|-----|-----------------------------|-----|
+| Get-OVS                     | 266 | Mh-Reference                | 259 |
+| Get-OVS-Position            | 266 |                             |     |
+| Get-PAP                     | 266 |                             |     |
+| Get-POS                     | 266 |                             |     |
+| Get-PVD                     | 266 | Mh-Target                   | 261 |
+| Get-PVS                     | 266 |                             |     |
+| Get-PVS-Position            | 265 |                             |     |
+| Get-Reference               | 267 |                             |     |
+| Get-Rt-Composite-Address    | 266 |                             |     |
+| Get-Stream-Chosen-State     | 265 | Mh-Target-Macro             | 261 |
+| Get-User-Spatial-Control    | 265 |                             |     |
+| GF                          | 269 |                             |     |
+| GF-Macro                    | 269 |                             |     |
+| GF-Param                    | 269 | Mh-Target-Param             | 261 |
+| GSF                         | 272 |                             |     |
+| GVF-Target                  | 288 |                             |     |
+| Initial-Point-Spec-Macro    | 270 |                             |     |
+| Initial-Point-Spec-Param    | 270 |                             |     |
+| Interaction-Status          | 271 | Min-Interact-Required-Macro | 288 |
+| Interaction-Status-Macro    | 288 |                             |     |
+| Interaction-Status-Param    | 288 |                             |     |
+| Interaction-Type            | 271 |                             |     |
+| Interaction-Type-Macro      | 271 | Min-Interact-Required-Param | 288 |
+| Interaction-Type-Param      | 271 |                             |     |
+| Length-Spec                 | 269 |                             |     |
+| Length-Spec-Macro           | 269 |                             |     |
+| Length-Spec-Param           | 269 |                             |     |
+| Lengths-Spec                | 269 | Model-Class                 | 258 |
+| Link-Class                  | 275 |                             |     |
+| Link-Condition              | 275 |                             |     |
+| Link-Effect                 | 276 |                             |     |
+| Link-Object                 | 279 | Modifiability               | 271 |
+| Logical-Combination         | 276 |                             |     |
+| Logical-Operator            | 276 |                             |     |
+| Macro-Def-ID                | 259 |                             |     |
+| Macro-Parameter-Resolution  | 276 |                             |     |
+| Max-Interact-Required-Macro | 288 | Modification-Status         | 271 |
+| Max-Interact-Required-Param | 288 |                             |     |
+| Mheg-ID                     | 259 |                             |     |
+| Mh-object-Class             | 258 |                             |     |
+
+|                              |     |                             |     |
+|------------------------------|-----|-----------------------------|-----|
+| Multiplexed-Content-Class    | 278 | Resizing-Strategy           | 272 |
+| Multiplexed-Stream           | 278 |                             |     |
+| Mux-Content-Class-Info       | 281 |                             |     |
+| Navigation-Command           | 273 |                             |     |
+| Navigation-Command-Macro     | 273 | Resizing-Strategy-Macro     | 287 |
+| Navigation-Command-Param     | 273 |                             |     |
+| Number-Of-Performances       | 285 |                             |     |
+| Number-Of-Performances-Macro | 285 |                             |     |
+| Number-Of-Performances-Param | 284 |                             |     |
+| Number-Of-Repetitions        | 286 | Resizing-Strategy-Param     | 287 |
+| Object-Information           | 281 |                             |     |
+| OD                           | 273 |                             |     |
+| OPS-Initialisation           | 268 |                             |     |
+| OV                           | 271 | Return                      | 283 |
+| OVS-Proj-Strategy            | 272 |                             |     |
+| OVS-Proj-Strategy-Macro      | 287 |                             |     |
+| OVS-Proj-Strategy-Param      | 287 |                             |     |
+| Passing                      | 285 |                             |     |
+| Passing-Macro                | 285 | Return-Target-Param         | 263 |
+| Passing-Param                | 285 |                             |     |
+| PCV                          | 271 |                             |     |
+| Plug                         | 285 |                             |     |
+| Plug-In                      | 285 | Root-Rt-Component-ID-Ref    | 260 |
+| Plug-In-Macro                | 285 |                             |     |
+| Plug-In-Param                | 285 |                             |     |
+| Point                        | 269 |                             |     |
+| Point-Spec                   | 270 |                             |     |
+| Point-Spec-Macro             | 270 | Root-Rt-Component-Reference | 260 |
+| Point-Spec-Param             | 270 |                             |     |
+| Points-Spec                  | 270 |                             |     |
+| Point-Type-Param             | 272 |                             |     |
+| Preparation-Status           | 274 | Root-Rt-Composite-ID-Ref    | 261 |
+| Presentation-Priority        | 273 |                             |     |
+| Presentation-Priority-Macro  | 286 |                             |     |
+| Presentation-Priority-Param  | 285 |                             |     |
+| Process-Indicator            | 284 |                             |     |
+| Prop-Cat-Entry-ID            | 268 | Root-Rt-Composite-Reference | 261 |
+| Ratio                        | 264 |                             |     |
+| Reference                    | 259 |                             |     |
+| Related-Object               | 281 |                             |     |
+
+|                               |     |                          |     |
+|-------------------------------|-----|--------------------------|-----|
+| Root-Rt-Content-ID-Ref        | 260 | Rt-Target-Param          | 262 |
+| Root-Rt-Content-Reference     | 260 |                          |     |
+| Root-Rt-ID-Reference          | 260 |                          |     |
+| Root-Rt-Mux-ID-Reference      | 260 |                          |     |
+| Root-Rt-Mux-Reference         | 260 | Run                      | 284 |
+| Root-Rt-Reference             | 260 |                          |     |
+| RPS-Assignment                | 273 |                          |     |
+| RPS-Assignment-Macro          | 285 |                          |     |
+| RPS-Assignment-Param          | 285 |                          |     |
+| Rt-Availability-Start-up      | 279 | Running-Status           | 273 |
+| Rt-Availability-Status        | 273 |                          |     |
+| Rt-Component-Channel-Ref      | 261 |                          |     |
+| Rt-Component-Channel-Tg       | 263 |                          |     |
+| Rt-Component-Channel-Tg-Macro | 263 | Script-Class             | 277 |
+| Rt-Component-Channel-Tg-Param | 263 |                          |     |
+| Rt-Component-Reference        | 260 |                          |     |
+| Rt-Component-Target           | 262 |                          |     |
+| Rt-Component-Target-Macro     | 262 | Script-Class-Information | 281 |
+| Rt-Component-Target-Param     | 262 |                          |     |
+| Rt-Composite-Reference        | 261 |                          |     |
+| Rt-Composite-Target           | 263 |                          |     |
+| Rt-Composite-Target-Macro     | 262 |                          |     |
+| Rt-Composite-Target-Param     | 262 | Script-Data              | 277 |
+| Rt-Content-Reference          | 260 |                          |     |
+| Rt-Content-Target             | 262 |                          |     |
+| Rt-Content-Target-Macro       | 262 |                          |     |
+| Rt-Content-Target-Param       | 262 |                          |     |
+| Rt-Mux-Reference              | 261 | Script-Hook              | 268 |
+| Rt-Mux-Target                 | 262 |                          |     |
+| Rt-Mux-Target-Macro           | 262 |                          |     |
+| Rt-Mux-Target-Param           | 262 |                          |     |
+| Rt-Number-Reference           | 260 | Script-Inclusion         | 277 |
+| Rt-Reference                  | 260 |                          |     |
+| Rt-Script-ID-Reference        | 260 |                          |     |
+| Rt-Script-Reference           | 260 |                          |     |
+| Rt-Script-Target              | 262 |                          |     |
+| Rt-Script-Target-Macro        | 262 | Selectability            | 271 |
+| Rt-Script-Target-Param        | 262 |                          |     |
+| Rt-Target                     | 262 |                          |     |
+| Rt-Target-Macro               | 262 |                          |     |
+
+|                            |     |                        |     |
+|----------------------------|-----|------------------------|-----|
+| Selection-Status           | 271 | Socket-Reference       | 261 |
+| Set-Alias                  | 283 |                        |     |
+| Set-Aspect-Ratio           | 286 |                        |     |
+| Set-Catalogued-Attribute   | 284 |                        |     |
+| Set-Channel-Perceptability | 289 |                        |     |
+| Set-CPS                    | 289 | Socket-Tail-Complement | 261 |
+| Set-CTP                    | 286 |                        |     |
+| Set-CV                     | 288 |                        |     |
+| Set-Data                   | 284 |                        |     |
+| Set-Event                  | 290 |                        |     |
+| Set-GSF                    | 287 | Socket-Tail-Reference  | 261 |
+| Set-GTF                    | 286 |                        |     |
+| Set-GVF                    | 288 |                        |     |
+| Set-Interaction-Ability    | 288 |                        |     |
+| Set-Interaction-Status     | 288 |                        |     |
+| Set-OAP                    | 287 | Socket-Target          | 263 |
+| Set-OVD                    | 286 |                        |     |
+| Set-OVS                    | 287 |                        |     |
+| Set-OVS-Position           | 287 |                        |     |
+| Set-OVS-Proj-Strategy      | 287 |                        |     |
+| Set-PAP                    | 287 | Socket-Target-Macro    | 263 |
+| Set-Parameters             | 285 |                        |     |
+| Set-Perceptability         | 285 |                        |     |
+| Set-Presentation-Priority  | 285 |                        |     |
+| Set-PVD-Position           | 286 |                        |     |
+| Set-PVS-Position           | 287 | Socket-Target-Param    | 263 |
+| Set-Resizing-Strategy      | 287 |                        |     |
+| Set-RPS-Assignment         | 285 |                        |     |
+| Set-Stream-Choice          | 288 |                        |     |
+| Set-Style                  | 289 |                        |     |
+| Set-Temporal-Termination   | 286 | Spatial-Control        | 272 |
+| Set-Timestones             | 286 |                        |     |
+| Set-User-Spatial-Control   | 287 |                        |     |
+| Size                       | 269 |                        |     |
+| Size-Spec                  | 269 |                        |     |
+| Size-Spec-Macro            | 269 | Spatial-Control-Macro  | 272 |
+| Size-Spec-Param            | 269 |                        |     |
+| Socket-ID                  | 259 |                        |     |
+| Socket-Identification      | 259 |                        |     |
+| Socket-ID-Reference        | 261 |                        |     |
+
+|                              |     |     |                            |     |
+|------------------------------|-----|-----|----------------------------|-----|
+| Spatial-Control-Param        | 272 |     | Timestone-Spec-Macro       | 286 |
+| Spatial-Length               | 269 |     |                            |     |
+| Spatial-Position             | 269 |     |                            |     |
+| Spatial-Position-Spec        | 270 |     |                            |     |
+| Spatial-Position-Spec-Macro  |     | 270 |                            |     |
+| Spatial-Position-Spec-Param  |     | 269 |                            |     |
+| Stream-Chosen-State          | 271 |     | Timestone-Spec-Param       | 286 |
+| Stream-Identification        | 271 |     |                            |     |
+| Stream-Identification-Macro  |     | 271 |                            |     |
+| Stream-Identification-Param  |     | 271 |                            |     |
+| Stream-Information           | 281 |     |                            |     |
+| Stream-Spec                  | 288 |     | Trigger-Condition          | 275 |
+| Stream-Spec-Macro            | 288 |     |                            |     |
+| Stream-Spec-Param            | 288 |     |                            |     |
+| Substitution-Indicator       | 284 |     |                            |     |
+| Substitution-Indicator-Macro |     | 284 |                            |     |
+| Substitution-Indicator-Param |     | 284 |                            |     |
+| Subtract                     | 284 |     | Update-Command             | 274 |
+| Synchro-Indicator            | 275 |     |                            |     |
+| Synchro-Indicator-Macro      |     | 275 |                            |     |
+| Synchro-Indicator-Param      |     | 275 |                            |     |
+| Synchronised-Action          | 275 |     |                            |     |
+| System-Readable-Material     |     | 281 | User-Spatial-Control       | 272 |
+| Tail-Complement              | 259 |     |                            |     |
+| Tail-Macro                   | 259 |     |                            |     |
+| Tail-Param                   | 259 |     |                            |     |
+| Tail-Reference               | 259 |     |                            |     |
+| Target-Macro                 | 261 |     |                            |     |
+| Target-Param                 | 261 |     | User-Spatial-Control-Macro | 287 |
+| Temporal-Termination         | 273 |     |                            |     |
+| Temporal-Termination-Macro   |     | 286 |                            |     |
+| Temporal-Termination-Param   |     | 286 |                            |     |
+| Temporal-Unit-Ref            | 283 |     |                            |     |
+| Temporal-Unit-Ref-Macro      |     | 283 |                            |     |
+| Temporal-Unit-Ref-Param      |     | 283 | User-Spatial-Control-Param | 287 |
+| Terminal-Point-Spec-Macro    |     | 270 |                            |     |
+| Terminal-Point-Spec-Param    |     | 270 |                            |     |
+| Termination-Status           | 273 |     |                            |     |
+| Timestone                    | 286 |     |                            |     |
+| Timestone-Spec               | 286 |     | Value                      | 263 |
+
+## Index of the behaviours
+
+| Behaviours                                             | Status and Attributes                                                                                                                       | Elementary Actions                                                                                                                      | Get Actions                                      |
+|--------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------|
+| Postpone behaviour                                     |                                                                                                                                             | <b>Delay</b> (Temporal Unit Ref Param, ...)                                                                                             |                                                  |
+| Returnability behaviour                                |                                                                                                                                             | <b>Return</b> (Return Target Param+, ...)                                                                                               |                                                  |
+| Alias behaviour                                        |                                                                                                                                             | <b>Set Alias</b> (Target Param+, ...)                                                                                                   |                                                  |
+| Extensibility behaviour                                | Catalogued Attribute@Cat<br>Ext Attribute Param@Cat<br>Ext Attribute Macro@                                                                 | <b>Catalogued Elementary Action</b> (Target Param+, ...)<br><b>Set Catalogued Attribute</b> (Target Param+, ...)                        | Get Catalogued Attribute@                        |
+| Mheg objects availability behaviour                    | Preparation Status@                                                                                                                         | <b>Prepare</b> (MH-Target Param+)<br><b>Destroy</b> (MH-Target Param+)                                                                  | Get Preparation Status@                          |
+| Link object activation behaviour                       | Activation Status@                                                                                                                          | <b>Activate</b> (Link Target Param+)<br><b>Deactivate</b> (Link Target Param+)                                                          | Get Activation Status@                           |
+| Link object abort behaviour                            |                                                                                                                                             | <b>Link Abort</b> (Link Target Param+)                                                                                                  |                                                  |
+| Content class generic value storage behaviour          | Data@                                                                                                                                       | <b>Set Data</b> (Content Target Param+, ...)<br><b>Add</b> (Content Target Param+, ...)<br><b>Subtract</b> (Content Target Param+, ...) | Get Data@                                        |
+| Content class copy behaviour                           |                                                                                                                                             | <b>Copy</b> (Content Target Param, ...)                                                                                                 |                                                  |
+| Rt-objects availability behaviour                      | Rt-Availability Status@                                                                                                                     | <b>New</b> (Rt-Target Param+)<br><b>Delete</b> (Rt-Target Param+)                                                                       | Get Rt-Availability Status@                      |
+| Rt-objects running behaviour                           | Running Status@                                                                                                                             | <b>Run</b> (Rt-Target Param+, ...)<br><b>Stop</b> (Rt-Target Param+)                                                                    | Get Running Status@                              |
+| Rt-script passing parameter behaviour                  |                                                                                                                                             | <b>Set Parameters</b> (Rt-Script Target Param+, ...)                                                                                    |                                                  |
+| Rt-scripts termination behaviour                       | Termination Status@                                                                                                                         |                                                                                                                                         | Get Termination Status@                          |
+| Sockets presentation and structural dynamism behaviour |                                                                                                                                             | <b>Plug</b> (Socket Target Param+, ...)                                                                                                 |                                                  |
+| Rt-composite navigation behaviour                      | Rt-Composite Address@Navigation Command<br>Param@Navigation Command<br>Macro@Navigation Command@<br>Child@Empty Child@Sibling@<br>Ancestor@ |                                                                                                                                         | Get Rt-Composite Address@                        |
+| Rt-components rps assignment behaviour                 | RPS Assignment@                                                                                                                             | <b>Set RPS Assignment</b> (Rt-Component Target Param+, ...)                                                                             | Get RPS Assignment@                              |
+| Rt-components perceptability behaviour                 | Perceptability@Presentation Priority@                                                                                                       | <b>Set Perceptability</b> (Rt-Component Target Param+, ...)<br><b>Set Presentation Priority</b> (Rt-Component Target Param+, ...)       | Get Perceptability<br>Get Presentation Priority@ |
+
+### Index of the behaviours *(continued)*
+
+| Behaviours                       | Status and Attributes                                                                                                                                                                                                                                                     | Elementary Actions                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      | Get Actions                                                                                                                                                                                                         |
+|----------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Rt-components temporal behaviour | OD@POD@OVD@PVD@<br>Temporal<br>Termination@PVD<br>Position@CTP@GTF@Timestone<br>Status@Timestone ID@Expected<br>OVD Result Param@Expected OVD<br>Result Macro@Expected OVD<br>Result@Expected PVD Result<br>Param@Expected PVD Result<br>Macro@Expected PVD Result@       | <b>Set OVD</b> (Rt-Component<br>Target Param+, ...)<br><b>Set CTP</b> (Rt-Component<br>Target Param+, ...)<br><b>Set Temporal<br/>Termination</b> (Rt-Target<br>Param+, ...)<br><b>Set PVD Position</b> (Socket<br>Target Param+, ...)<br><b>Set GTF</b> (Rt-Component<br>Target Param+, ...)<br><b>Set Timestones</b> (Rt-<br>Component Target<br>Param+, ...)                                                                                                                                                                                                                         | Get OD<br>Get POD<br>Get OVD<br>Get PVD<br>Get CTP<br>Get Temporal Termination<br>Get PVD Position<br>Get GTF<br>Get Timestone Status@                                                                              |
+| Rt-components spatial behaviour  | OS@POS@Aspect Ratio@Resizing<br>Strategy@OVS@OAP@OVS<br>Position@PVS@OVS Proj<br>Strategy@PAP@PVS<br>Position@GSF@Spatial<br>Control@User Spatial<br>Control@Expected Axis Result<br>Param@Spatial Control<br>Param@Spatial Control<br>Macro@Point Type Param@            | <b>Set Aspect Ratio</b> (Rt-<br>Component Target<br>Param+, ...)<br><b>Set Resizing Strategy</b><br>(Rt-Composite Target<br>Param+, ...)<br><b>Set OVS</b> (Rt-Component<br>Target Param+, ...)<br><b>Set OAP</b> (Rt-Component<br>Target Param+, ...)<br><b>Set OVS Position</b> (Rt-<br>Component Target<br>Param+, ...)<br><b>Set PAP</b> (Rt-Component<br>Target Param+, ...)<br><b>Set PVS Position</b> (Rt-<br>Component Target<br>Param+, ...)<br><b>Set GSF</b> (Rt-Component<br>Target Param+, ...)<br><b>Set User Spatial Control</b><br>(Rt-Component Target<br>Param+, ...) | Get OS<br>Get POS<br>Get Aspect Ratio<br>Get Resizing Strategy<br>Get OVS Proj Strategy<br>Get OVS<br>Get OAP<br>Get OVS Position<br>Get PVS<br>Get PAP<br>Get PVS Position<br>Get GSF<br>Get User Spatial Control@ |
+| Rt-components audible behaviour  | OV@CV@PCV@GVF@                                                                                                                                                                                                                                                            | <b>Set CV</b> (Rt-Content<br>Target Param+, ...)<br><b>Set GVF</b> (GVF Target, ...)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    | Get OV<br>Get CV<br>Get PCV<br>Get GVF@                                                                                                                                                                             |
+| Rt-mux stream choice behaviour   | Stream Choice@Stream Chosen<br>State@Stream Identification<br>Param@Stream Identification<br>Macro@Stream Identification@                                                                                                                                                 | <b>Set Stream Choice</b> (Rt-<br>Mux Target Param+, ...)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                | Get Stream Choice<br>Get Stream Chosen State@                                                                                                                                                                       |
+| Interaction behaviour            | Interaction Type Param@Interaction<br>Type Macro@Interaction<br>Type@Interaction Status@Selection<br>Status@Modification<br>Status@Interaction<br>Ability@Selectability@Modifiability<br>@Min Interact Required@Max<br>Interact Required@Number Of<br>Interacted Sockets@ | <b>Set Interaction Ability</b><br>(Rt-Component Target<br>Param+, ...)<br><b>Set Interaction Status</b><br>(Rt-Component Target<br>Param+, ...)                                                                                                                                                                                                                                                                                                                                                                                                                                         | Get Interaction Ability<br>Get Min Interact Required<br>Get Max Interact Required<br>Get Interaction Status<br>Get Number Of Interacted<br>Sockets@                                                                 |
+| Rt-components style behaviour    | Style                                                                                                                                                                                                                                                                     | <b>Set Style</b> (Rt-Component<br>Target Param+, ...)<br><b>Get Style</b> (Rt-Component<br>Target Param)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |                                                                                                                                                                                                                     |
+| Rt-contents anchor behaviour     |                                                                                                                                                                                                                                                                           | <b>Attach Anchor</b> (Rt-<br>Content Target Param+,<br>...)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                     |
+| Channel availability behaviour   | Channel Availability Status                                                                                                                                                                                                                                               | <b>New Channel</b> (Channel<br>Target Param+)<br><b>Delete Channel</b> (Channel<br>Target Param+)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       | Get Channel Availability<br>Status                                                                                                                                                                                  |
+
+### Index of the behaviours *(concluded)*
+
+| Behaviours                                  | Status and Attributes  | Elementary Actions                                             | Get Actions                 |
+|---------------------------------------------|------------------------|----------------------------------------------------------------|-----------------------------|
+| Channel perceptability behaviour            | Channel Perceptability | <b>Set Channel Perceptability</b> (Channel Target Param+, ...) | Get Channel Perceptability  |
+| Channel presentation space behaviour        |                        | <b>Set CPS</b> (Channel Target Param+, ...)                    |                             |
+| Channels and rt-components events behaviour | Event<br>Event Data    | <b>Set Event</b> (Rt-Component Channel Tg Param+, ...)         | Get Event<br>Get Event Data |
+
+## ITU-T RECOMMENDATIONS SERIES
+
+|                 |                                                                                                                |
+|-----------------|----------------------------------------------------------------------------------------------------------------|
+| Series A        | Organization of the work of the ITU-T                                                                          |
+| Series B        | Means of expression: definitions, symbols, classification                                                      |
+| Series C        | General telecommunication statistics                                                                           |
+| Series D        | General tariff principles                                                                                      |
+| Series E        | Overall network operation, telephone service, service operation and human factors                              |
+| Series F        | Non-telephone telecommunication services                                                                       |
+| Series G        | Transmission systems and media, digital systems and networks                                                   |
+| Series H        | Audiovisual and multimedia systems                                                                             |
+| Series I        | Integrated services digital network                                                                            |
+| Series J        | Transmission of television, sound programme and other multimedia signals                                       |
+| Series K        | Protection against interference                                                                                |
+| Series L        | Construction, installation and protection of cables and other elements of outside plant                        |
+| Series M        | Maintenance: international transmission systems, telephone circuits, telegraphy, facsimile and leased circuits |
+| Series N        | Maintenance: international sound programme and television transmission circuits                                |
+| Series O        | Specifications of measuring equipment                                                                          |
+| Series P        | Telephone transmission quality, telephone installations, local line networks                                   |
+| Series Q        | Switching and signalling                                                                                       |
+| Series R        | Telegraph transmission                                                                                         |
+| Series S        | Telegraph services terminal equipment                                                                          |
+| <b>Series T</b> | <b>Terminals for telematic services</b>                                                                        |
+| Series U        | Telegraph switching                                                                                            |
+| Series V        | Data communication over the telephone network                                                                  |
+| Series X        | Data networks and open system communication                                                                    |
+| Series Z        | Programming languages                                                                                          |
\ No newline at end of file
diff --git a/marked/T/T-REC-T.174-199610-I_PDF-E/11edb7fcedf09ac6a817f8d7b8c61eec_img.jpg b/marked/T/T-REC-T.174-199610-I_PDF-E/11edb7fcedf09ac6a817f8d7b8c61eec_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..1cbde1b5388b5a4ecc9e0ef41d3c9c2e16473110
--- /dev/null
+++ b/marked/T/T-REC-T.174-199610-I_PDF-E/11edb7fcedf09ac6a817f8d7b8c61eec_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:9e51453fc195a09c2ecc628ed301f631ca8f77cc9de4aaf411eacea959b2c763
+size 163479
diff --git a/marked/T/T-REC-T.174-199610-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/T/T-REC-T.174-199610-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..b73ae7b224334eb2b14f93cf7b97a5c04b08fc15
--- /dev/null
+++ b/marked/T/T-REC-T.174-199610-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:516392c22fcb61c1d767adb7daf3bc0cdef2922b2166d36e6ad5c3a5b93848c5
+size 8330
diff --git a/marked/T/T-REC-T.174-199610-I_PDF-E/7d3d5fb5d09c0cd35a9d637be241651e_img.jpg b/marked/T/T-REC-T.174-199610-I_PDF-E/7d3d5fb5d09c0cd35a9d637be241651e_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..36f466711f5b4c93d0a9dbd5b3a464733a712aea
--- /dev/null
+++ b/marked/T/T-REC-T.174-199610-I_PDF-E/7d3d5fb5d09c0cd35a9d637be241651e_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:d2d13a1ab1c3e8b4d79d805a632296f40d58f36b42b6cb10f0b0ad1d740a98cd
+size 21954
diff --git a/marked/T/T-REC-T.174-199610-I_PDF-E/9c6461e1e94afae4dec455e69a2ce152_img.jpg b/marked/T/T-REC-T.174-199610-I_PDF-E/9c6461e1e94afae4dec455e69a2ce152_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..261d8a746dec10e1d00ac8b5d9fa6ee27d8b1768
--- /dev/null
+++ b/marked/T/T-REC-T.174-199610-I_PDF-E/9c6461e1e94afae4dec455e69a2ce152_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:b7161fff1577d3156221d6729ad641c9e3207d8ede6b90b531666dc2019acdd4
+size 138715
diff --git a/marked/T/T-REC-T.174-199610-I_PDF-E/b6671cfafda3820aafe9a24fa7a4d8c7_img.jpg b/marked/T/T-REC-T.174-199610-I_PDF-E/b6671cfafda3820aafe9a24fa7a4d8c7_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..e14ff333aff960e0f885af6894090c43deb4a4c4
--- /dev/null
+++ b/marked/T/T-REC-T.174-199610-I_PDF-E/b6671cfafda3820aafe9a24fa7a4d8c7_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:199e5f438be89b16fc04b767b9f10b42429932ee14b25de7d61303a8f1ca0794
+size 125404
diff --git a/marked/T/T-REC-T.174-199610-I_PDF-E/raw.md b/marked/T/T-REC-T.174-199610-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..c3a1fbe000a66348b8009aa41f1800e19f5acbe7
--- /dev/null
+++ b/marked/T/T-REC-T.174-199610-I_PDF-E/raw.md
@@ -0,0 +1,12674 @@
+
+
+![ITU logo: a globe with the letters ITU inside, and a lightning bolt striking the globe.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg)
+
+ITU logo: a globe with the letters ITU inside, and a lightning bolt striking the globe.
+
+INTERNATIONAL TELECOMMUNICATION UNION
+
+# ITU-T
+
+TELECOMMUNICATION  
+STANDARDIZATION SECTOR  
+OF ITU
+
+# T.174
+
+(10/96)
+
+SERIES T: TERMINALS FOR TELEMATIC SERVICES
+
+---
+
+# **Application Programming Interface (API) for MHEG-1**
+
+ITU-T Recommendation T.174
+
+(Previously CCITT Recommendation)
+
+---
+
+# ITU-T T-SERIES RECOMMENDATIONS **TERMINALS FOR TELEMATIC SERVICES**
+
+*For further details, please refer to ITU-T List of Recommendations.*
+
+# FOREWORD
+
+The ITU-T (Telecommunication Standardization Sector) is a permanent organ of the International Telecommunication Union (ITU). The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis.
+
+The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics.
+
+The approval of Recommendations by the Members of the ITU-T is covered by the procedure laid down in WTSC Resolution No. 1 (Helsinki, March 1-12, 1993).
+
+ITU-T Recommendation T.174 was prepared by ITU-T Study Group 8 (1993-1996) and was approved by the WTSC (Geneva, 9-18 October 1996).
+
+# --- NOTE
+
+In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+© ITU 1997
+
+All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU.
+
+# CONTENTS
+
+|   |                                                                         | <i>Page</i> |
+|---|-------------------------------------------------------------------------|-------------|
+| 1 | Scope .....                                                             | 1           |
+| 2 | References .....                                                        | 1           |
+| 3 | Definitions and abbreviations .....                                     | 2           |
+|   | 3.1 Definitions .....                                                   | 2           |
+|   | 3.2 Abbreviations .....                                                 | 5           |
+| 4 | Conformance .....                                                       | 6           |
+|   | 4.1 Implementation conformance .....                                    | 6           |
+|   | 4.1.1 Conformance requirements .....                                    | 6           |
+|   | 4.1.2 Conformance documentation .....                                   | 7           |
+|   | 4.2 Application conformance .....                                       | 7           |
+|   | 4.2.1 Strictly Conforming Application .....                             | 7           |
+|   | 4.2.2 Conforming Application .....                                      | 8           |
+|   | 4.3 Test Methods .....                                                  | 8           |
+| 5 | General description .....                                               | 8           |
+|   | 5.1 Functional reference model of MHEG using applications .....         | 8           |
+|   | 5.1.1 Reference model for multimedia applications .....                 | 8           |
+|   | 5.1.2 The MHEG-API .....                                                | 12          |
+|   | 5.2 Functional specification of the MHEG-API .....                      | 13          |
+|   | 5.2.1 MHEG usage specifications .....                                   | 13          |
+|   | 5.2.1.1 Definitions .....                                               | 13          |
+|   | 5.2.1.2 MHEG objects .....                                              | 13          |
+|   | 5.2.1.3 Mh-objects .....                                                | 13          |
+|   | 5.2.1.4 Rt-objects .....                                                | 14          |
+|   | 5.2.1.5 Channels .....                                                  | 14          |
+|   | 5.2.1.6 Interchanged MHEG objects .....                                 | 14          |
+|   | 5.2.2 Description of MHEG-related services .....                        | 14          |
+| 6 | API definition principles .....                                         | 15          |
+|   | 6.1 Satisfaction of technical requirements on the MHEG-API .....        | 15          |
+|   | 6.2 Use of Interface Definition Language (IDL) ISO/IEC 14750 [10] ..... | 16          |
+|   | 6.2.1 Comprehensive introduction to IDL .....                           | 16          |
+|   | 6.2.2 The Interface Definition Language .....                           | 16          |
+|   | 6.2.2.1 Objects .....                                                   | 17          |
+|   | 6.2.2.2 Requests .....                                                  | 17          |
+|   | 6.2.2.3 Types .....                                                     | 17          |
+|   | 6.2.2.4 Interfaces .....                                                | 18          |
+|   | 6.2.2.5 Operations .....                                                | 18          |
+|   | 6.2.2.6 Attributes .....                                                | 18          |
+|   | 6.2.2.7 Subtyping versus inheritance .....                              | 18          |
+|   | 6.2.2.8 Subtyping .....                                                 | 19          |
+|   | 6.2.2.9 Inheritance .....                                               | 19          |
+|   | 6.2.3 Principles for mapping IDL interfaces to API primitives .....     | 19          |
+|   | 6.2.4 Fulfilment of technical requirements .....                        | 19          |
+|   | 6.3 Overview of the API definition and general principles .....         | 19          |
+|   | 6.3.1 The MHEG-API Object model .....                                   | 19          |
+| 7 | Definition of the MHEG-API .....                                        | 21          |
+|   | 7.1 Mandatory primitives .....                                          | 21          |
+|   | 7.1.1 MHEGEngine object .....                                           | 21          |
+|   | 7.1.1.1 initialiseEngine operation .....                                | 21          |
+|   | 7.1.1.2 shutdownEngine operation .....                                  | 21          |
+|   | 7.1.1.3 IDL description .....                                           | 21          |
+
+|                                               | <i>Page</i> |
+|-----------------------------------------------|-------------|
+| 7.1.2 NotificationManager object .....        | 21          |
+| 7.1.2.1 getReturnability operation.....       | 21          |
+| 7.1.2.2 getNotification operation .....       | 21          |
+| 7.1.2.3 IDL description .....                 | 22          |
+| 7.1.3 EntityManager object.....               | 22          |
+| 7.1.3.1 getAvailableMhObjects operation ..... | 22          |
+| 7.1.3.2 getAvailableRtObjects operation ..... | 22          |
+| 7.1.3.3 getAvailableChannels operation .....  | 23          |
+| 7.1.3.4 releaseAlias operation.....           | 23          |
+| 7.1.3.5 IDL description .....                 | 23          |
+| 7.1.4 Entity object.....                      | 23          |
+| 7.1.4.1 setAlias operation.....               | 23          |
+| 7.1.4.2 getAlias operation .....              | 24          |
+| 7.1.4.3 IDL description .....                 | 24          |
+| 7.1.5 MhObject object.....                    | 24          |
+| 7.1.5.1 bind operation .....                  | 24          |
+| 7.1.5.2 unbind operation .....                | 25          |
+| 7.1.5.3 prepare operation .....               | 25          |
+| 7.1.5.4 destroy operation.....                | 25          |
+| 7.1.5.5 getPreparationStatus operation .....  | 26          |
+| 7.1.5.6 getIdentifier operation.....          | 26          |
+| 7.1.5.7 kill operation .....                  | 26          |
+| 7.1.5.8 IDL description .....                 | 26          |
+| 7.1.6 MhAction object .....                   | 27          |
+| 7.1.6.1 delay operation.....                  | 27          |
+| 7.1.6.2 IDL description .....                 | 27          |
+| 7.1.7 MhLink object.....                      | 29          |
+| 7.1.7.1 abort operation .....                 | 29          |
+| 7.1.7.2 IDL description .....                 | 29          |
+| 7.1.8 MhModel object.....                     | 29          |
+| 7.1.8.1 IDL description .....                 | 29          |
+| 7.1.9 MhComponent object.....                 | 29          |
+| 7.1.9.1 IDL description .....                 | 29          |
+| 7.1.10 MhGenericContent object.....           | 29          |
+| 7.1.10.1 copy operation.....                  | 29          |
+| 7.1.10.2 IDL description .....                | 30          |
+| 7.1.11 MhContent object.....                  | 30          |
+| 7.1.11.1 setData operation .....              | 30          |
+| 7.1.11.2 getData operation.....               | 31          |
+| 7.1.11.3 IDL description .....                | 31          |
+| 7.1.12 MhMultiplexedContent object.....       | 31          |
+| 7.1.12.1 setMultiplex operation .....         | 31          |
+| 7.1.12.2 setDemultiplex operation .....       | 32          |
+| 7.1.12.3 IDL description .....                | 32          |
+| 7.1.13 MhComposite object.....                | 32          |
+| 7.1.13.1 IDL description .....                | 32          |
+| 7.1.14 MhScript object.....                   | 33          |
+| 7.1.14.1 IDL description .....                | 33          |
+| 7.1.15 MhContainer object .....               | 33          |
+| 7.1.15.1 IDL description .....                | 33          |
+| 7.1.16 MhDescriptor object .....              | 33          |
+| 7.1.16.1 IDL description .....                | 33          |
+| 7.1.17 RtObjectOrSocket object .....          | 33          |
+| 7.1.17.1 setGlobalBehaviour operation.....    | 33          |
+| 7.1.17.2 getGlobalBehaviour operation .....   | 33          |
+| 7.1.17.3 run operation .....                  | 34          |
+| 7.1.17.4 stop operation.....                  | 34          |
+| 7.1.17.5 IDL description .....                | 34          |
+
+|                                                       | <i>Page</i> |
+|-------------------------------------------------------|-------------|
+| 7.1.18 RtObject object .....                          | 35          |
+| 7.1.18.1 bind operation .....                         | 35          |
+| 7.1.18.2 unbind operation .....                       | 35          |
+| 7.1.18.3 new operation.....                           | 35          |
+| 7.1.18.4 delete operation .....                       | 36          |
+| 7.1.18.5 getAvailabilityStatus operation.....         | 36          |
+| 7.1.18.6 getIdentifier operation.....                 | 36          |
+| 7.1.18.7 kill operation .....                         | 37          |
+| 7.1.18.8 getRunningStatus operation .....             | 37          |
+| 7.1.18.9 IDL description .....                        | 37          |
+| 7.1.19 Socket object.....                             | 38          |
+| 7.1.19.1 bind operation .....                         | 38          |
+| 7.1.19.2 unbind operation .....                       | 38          |
+| 7.1.19.3 getIdentifier operation.....                 | 38          |
+| 7.1.19.4 kill operation .....                         | 38          |
+| 7.1.19.5 plug operation .....                         | 39          |
+| 7.1.19.6 setVisibleDurationPosition operation .....   | 39          |
+| 7.1.19.7 getVisibleDurationPosition operation .....   | 39          |
+| 7.1.19.8 IDL description .....                        | 40          |
+| 7.1.20 RtScript object .....                          | 40          |
+| 7.1.20.1 setParameters operation .....                | 40          |
+| 7.1.20.2 getTerminationStatus operation .....         | 41          |
+| 7.1.20.3 IDL description .....                        | 41          |
+| 7.1.21 RtComponentOrSocket object .....               | 41          |
+| 7.1.21.1 setRGS operation .....                       | 41          |
+| 7.1.21.2 getRGS operation.....                        | 42          |
+| 7.1.21.3 setOpacity operation .....                   | 42          |
+| 7.1.21.4 setPresentationPriority operation .....      | 42          |
+| 7.1.21.5 getOpacity operation.....                    | 43          |
+| 7.1.21.6 getEffectiveOpacity operation .....          | 43          |
+| 7.1.21.7 getPresentationPriority operation.....       | 43          |
+| 7.1.21.8 setVisibleDuration operation .....           | 44          |
+| 7.1.21.9 setTemporalTermination operation.....        | 44          |
+| 7.1.21.10 setCurrentTemporalPosition operation .....  | 45          |
+| 7.1.21.11 setSpeed operation .....                    | 45          |
+| 7.1.21.12 setTimestones operation.....                | 46          |
+| 7.1.21.13 getInitialTemporalPosition operation.....   | 46          |
+| 7.1.21.14 getTerminalTemporalPosition operation.....  | 46          |
+| 7.1.21.15 getVDLength operation .....                 | 47          |
+| 7.1.21.16 getTemporalTermination operation .....      | 47          |
+| 7.1.21.17 getCurrentTemporalPosition operation.....   | 47          |
+| 7.1.21.18 getSpeedRate operation.....                 | 48          |
+| 7.1.21.19 getOGTR operation.....                      | 48          |
+| 7.1.21.20 getEffectiveSpeedRate operation .....       | 48          |
+| 7.1.21.21 getEffectiveOGTR operation .....            | 49          |
+| 7.1.21.22 getTimestoneStatus operation .....          | 49          |
+| 7.1.21.23 setPerceptibleSizeProjection operation..... | 49          |
+| 7.1.21.24 setAspectRatio operation .....              | 50          |
+| 7.1.21.25 setVisibleSize operation.....               | 50          |
+| 7.1.21.26 setVisibleSizesAdjustment operation.....    | 51          |
+| 7.1.21.27 setBox operation .....                      | 51          |
+| 7.1.21.28 setDefaultBackground operation.....         | 52          |
+| 7.1.21.29 setAttachmentPoint operation.....           | 52          |
+| 7.1.21.30 setAttachmentPointPosition operation.....   | 53          |
+| 7.1.21.31 setVisibleSizesAlignment operation .....    | 53          |
+| 7.1.21.32 setMovingAbility operation .....            | 54          |
+| 7.1.21.33 setResizingAbility operation.....           | 54          |
+| 7.1.21.34 setScalingAbility operation.....            | 55          |
+| 7.1.21.35 setScrollingAbility operation .....         | 55          |
+
+|                                                                           | <i>Page</i> |
+|---------------------------------------------------------------------------|-------------|
+| 7.1.21.36 getGSR operation.....                                           | 55          |
+| 7.1.21.37 getPS operation .....                                           | 56          |
+| 7.1.21.38 getAspectRatio operation.....                                   | 56          |
+| 7.1.21.39 getPSAP operation .....                                         | 56          |
+| 7.1.21.40 getVSGS operation .....                                         | 57          |
+| 7.1.21.41 getVS operation .....                                           | 57          |
+| 7.1.21.42 getBox operation.....                                           | 57          |
+| 7.1.21.43 getDefaultBackground operation .....                            | 58          |
+| 7.1.21.44 getVSIAP operation .....                                        | 58          |
+| 7.1.21.45 getVSIAPPosition operation .....                                | 58          |
+| 7.1.21.46 getVSEAP operation .....                                        | 59          |
+| 7.1.21.47 getVSEAPPosition operation.....                                 | 59          |
+| 7.1.21.48 getMovingAbility operation.....                                 | 60          |
+| 7.1.21.49 getResizingAbility operation .....                              | 60          |
+| 7.1.21.50 getScalingAbility operation .....                               | 60          |
+| 7.1.21.51 getScrollingAbility operation.....                              | 61          |
+| 7.1.21.52 setSelectability operation .....                                | 61          |
+| 7.1.21.53 setSelectionStatus operation .....                              | 61          |
+| 7.1.21.54 setSelectionPresentationEffectResponsibility operation.....     | 62          |
+| 7.1.21.55 getSelectability operation.....                                 | 62          |
+| 7.1.21.56 getEffectiveSelectability operation .....                       | 63          |
+| 7.1.21.57 getSelectionStatus operation .....                              | 63          |
+| 7.1.21.58 getSelectionMode operation .....                                | 63          |
+| 7.1.21.59 getSelectionPresentationEffectResponsibility operation .....    | 64          |
+| 7.1.21.60 setModifiability operation.....                                 | 64          |
+| 7.1.21.61 setModificationStatus operation .....                           | 65          |
+| 7.1.21.62 setModificationPresentationEffectResponsibility operation.....  | 65          |
+| 7.1.21.63 getModifiability operation .....                                | 65          |
+| 7.1.21.64 getEffectiveModifiability operation.....                        | 66          |
+| 7.1.21.65 getModificationStatus operation .....                           | 66          |
+| 7.1.21.66 getModificationMode operation .....                             | 66          |
+| 7.1.21.67 getModificationPresentationEffectResponsibility operation ..... | 67          |
+| 7.1.21.68 setNoInteractionStyle operation.....                            | 67          |
+| 7.1.21.69 IDL description .....                                           | 67          |
+| 7.1.22 RtComponent object .....                                           | 73          |
+| 7.1.22.1 IDL description .....                                            | 73          |
+| 7.1.23 RtCompositeOrStructuralSocket object.....                          | 73          |
+| 7.1.23.1 setResizingStrategy operation.....                               | 73          |
+| 7.1.23.2 getResizingStrategy operation .....                              | 73          |
+| 7.1.23.3 setAudibleCompositionEffect operation.....                       | 74          |
+| 7.1.23.4 getAudibleCompositionEffect operation .....                      | 74          |
+| 7.1.23.5 getNumberOfSelectedSockets operation .....                       | 74          |
+| 7.1.23.6 getNumberOfModifiedSockets operation .....                       | 75          |
+| 7.1.23.7 setMenuInteractionStyle operation .....                          | 75          |
+| 7.1.23.8 setScrollingListInteractionStyle operation.....                  | 76          |
+| 7.1.23.9 IDL description .....                                            | 77          |
+| 7.1.24 RtComposite object.....                                            | 77          |
+| 7.1.24.1 IDL description .....                                            | 78          |
+| 7.1.25 StructuralSocket object .....                                      | 78          |
+| 7.1.25.1 IDL description .....                                            | 78          |
+| 7.1.26 RtGenericContentOrPresentableSocket object .....                   | 78          |
+| 7.1.26.1 setAudibleVolume operation .....                                 | 78          |
+| 7.1.26.2 getInitialOriginalAudibleVolume operation .....                  | 78          |
+| 7.1.26.3 getCurrentOriginalAudibleVolume operation .....                  | 79          |
+| 7.1.26.4 getEffectiveOriginalAudibleVolume operation .....                | 79          |
+| 7.1.26.5 getPerceptibleAudibleVolume operation .....                      | 79          |
+| 7.1.26.6 setButtonInteractionStyle operation.....                         | 80          |
+| 7.1.26.7 IDL description .....                                            | 81          |
+
+|                                                            | <i>Page</i> |
+|------------------------------------------------------------|-------------|
+| 7.1.27 RtGenericContent object.....                        | 81          |
+| 7.1.27.1 IDL description .....                             | 81          |
+| 7.1.28 GenericPresentableSocket object.....                | 81          |
+| 7.1.28.1 IDL description .....                             | 81          |
+| 7.1.29 RtContentOrPresentableSocket object.....            | 81          |
+| 7.1.29.1 setSliderInteractionStyle operation.....          | 82          |
+| 7.1.29.2 setEntryFieldInteractionStyle operation.....      | 82          |
+| 7.1.29.3 IDL description .....                             | 83          |
+| 7.1.30 RtContent object .....                              | 83          |
+| 7.1.30.1 IDL description .....                             | 83          |
+| 7.1.31 PresentableSocket object.....                       | 83          |
+| 7.1.31.1 IDL description .....                             | 83          |
+| 7.1.32 RtMultiplexedContentOrPresentableSocket object..... | 83          |
+| 7.1.32.1 setStreamChoice operation .....                   | 84          |
+| 7.1.32.2 getStreamChosen operation .....                   | 84          |
+| 7.1.32.3 IDL description .....                             | 84          |
+| 7.1.33 RtMultiplexedContent object.....                    | 85          |
+| 7.1.33.1 IDL description .....                             | 85          |
+| 7.1.34 MultiplexedPresentableSocket object .....           | 85          |
+| 7.1.34.1 IDL description .....                             | 85          |
+| 7.1.35 Channel object .....                                | 85          |
+| 7.1.35.1 bind operation .....                              | 85          |
+| 7.1.35.2 unbind operation .....                            | 85          |
+| 7.1.35.3 new operation.....                                | 86          |
+| 7.1.35.4 delete operation.....                             | 86          |
+| 7.1.35.5 getRtAvailabilityStatus operation .....           | 87          |
+| 7.1.35.6 getIdentifier operation.....                      | 87          |
+| 7.1.35.7 kill operation .....                              | 87          |
+| 7.1.35.8 setPerceptability operation.....                  | 87          |
+| 7.1.35.9 getPerceptability operation .....                 | 88          |
+| 7.1.35.10 getAssignedPerceptibles operation .....          | 88          |
+| 7.1.35.11 IDL description .....                            | 88          |
+| 7.1.36 Parameter definition.....                           | 89          |
+| 7.1.37 Exceptions.....                                     | 105         |
+| 7.1.37.1 InvalidTarget exception .....                     | 105         |
+| 7.1.37.2 InvalidParameter exception.....                   | 105         |
+| 7.1.37.3 NotBound exception .....                          | 105         |
+| 7.1.37.4 AlreadyBound exception .....                      | 105         |
+| 7.1.37.5 IDL definition .....                              | 105         |
+| 7.2 Optional primitives .....                              | 105         |
+| Annex A – Complete IDL definition of the MHEG API.....     | 105         |
+
+## SUMMARY
+
+This Recommendation specifies the abstract Application Programming Interface (API) for the manipulation of multimedia and hypermedia information objects, i.e. the API that shall be provided by MHEG engines for their control by MHEG applications.
+
+## INTRODUCTION
+
+This Recommendation specifies the abstract Application Programming Interface (API) for the manipulation of multimedia and hypermedia information objects, i.e. the API that shall be provided by MHEG engines for their control by MHEG applications.
+
+This Recommendation is part of a broader standardisation framework that specifies the usage of MHEG so that interoperable equipments can be effectively developed to support multimedia information services and applications. This implies:
+
+- specifying additional constraints to the use of MHEG objects within distributed systems and applications using telecommunication networks;
+- defining APIs that building blocks of MHEG-using architectures should provide;
+- defining MHEG profiles complementing the MHEG-1 standard by specifying restrictions on the coded representation and specifying the complete required behaviour of an MHEG engine that should be supported for a given category of applications and/or terminal equipments;
+- defining an MHEG script interchange representation;
+- defining end-to-end protocols for MHEG-using multimedia/hypermedia information services;
+- specifying conformance testing procedures for these standards.
+
+Functional and technical requirements on this Recommendation have been described in ETR 225.
+
+
+
+## APPLICATION PROGRAMMING INTERFACE (API) FOR MHEG-1
+
+(Geneva, 1996)
+
+### 1 Scope
+
+MHEG Part 1 (ISO/IEC 13522-1 [1]) is a generic standard, which specifies the coded representation of interchanged multimedia/hypermedia information objects (MHEG objects). These so-called MHEG objects are handled, interpreted and presented by MHEG engines.
+
+This Recommendation specifies the abstract Application Programming Interface (API) for the manipulation of multimedia and hypermedia information objects, i.e. the API that shall be provided by MHEG engines for their control by MHEG applications.
+
+This API meets the following requirements:
+
+- it is independent of the programming language used for the MHEG application;
+- it is independent of the underlying operating system;
+- it is independent of the mechanism used for interchanging information between the API user (i.e. MHEG application) and the API provider (i.e. MHEG engine), i.e. the messages that are exchanged as the result of triggering API primitives;
+- it is independent of the actual encoding of these messages;
+- it is generic and meant to cover all application requirements;
+- it is conformance testable;
+- it aims to be as easy as possible to implement.
+
+### 2 References
+
+The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; all users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published.
+
+- [1] ISO/IEC 13522-1:1997, *Information technology – Coding of multimedia and hypermedia information – Part 1: MHEG object representation – Base Notation (ASN.1)*.
+- [2] ITU-T Recommendation X.290 (1995), *OSI conformance testing methodology and framework for protocol Recommendations for ITU-T applications – General concepts*.
+- [3] ETR 173: *Terminal Equipment (TE) – Functional Model for Multimedia Applications*.
+- [4] ETR 225: *Terminal Equipment (TE) – API and script representation for MHEG – Requirements and framework*.
+- [5] CCITT Recommendation X.208 (1988), *Specification of Abstract Syntax Notation One (ASN.1)*.
+- [6] CCITT Recommendation X.209 (1988), *Specification of basic encoding rules for Abstract Syntax Notation One (ASN.1)*.
+- [7] ITU-T Recommendation I.113 (1993), *Vocabulary of terms for broadband aspects of ISDN*.
+- [8] ITU-T Recommendation I.112 (1993), *Vocabulary of terms for ISDNs*.
+- [9] CCITT Recommendation Q.9 (1988), *Vocabulary of switching and signalling terms*.
+
+- [10] ISO/IEC 14750<sup>1)</sup>, *Information technology – Open Distributed Processing – Interface Definition Language*.  
+[11] ISO/IEC JTC 1 N 2965:1994, *Guidelines for JTC 1 API Standardisation*.
+
+### 3 Definitions and abbreviations
+
+#### 3.1 Definitions
+
+Due to the particular nature of this Recommendation, some of the words and expressions used in this Recommendation come from the 'telecommunication services' standards glossary, while others come from the 'software technology' standards glossary. This leads to words whose meaning vary according to the context, i.e. the expression within which they are used. For this reason, many of these expressions are defined in this subclause.
+
+Should any ambiguity occur, definitions of the following Standards/Recommendations would apply, in decreasing order:
+
+- ISO/IEC 13522-1 [1] MHEG;
+- any other standard part of ISO/IEC 13522 [1] MHEG;
+- CCITT Recommendation I.113 [7], "Vocabulary of terms for broadband aspects";
+- CCITT Recommendation I.112 [8], "Vocabulary of terms for ISDNs";
+- CCITT Recommendation Q.9 [9], "Vocabulary of switching and signalling terms".
+
+This Recommendation defines the following terms:
+
+**3.1.1 application programming interface (API):** A boundary across which a software application uses facilities of programming languages to invoke software services. These facilities may include procedures or operations, shared data objects and resolution of identifiers.
+
+**3.1.2 function family:** Cluster of functional MHEG-API requirements consisting of functions with related semantics and applying on a same type of target.
+
+**3.1.3 hypermedia:** The ability to access monomedia and multimedia information by interaction with explicit links.
+
+**3.1.4 interactive service:** A service which provides the means for bidirectional exchange of information between users or between users and hosts. Interactive services are subdivided into three classes of services: conversational services, messaging services and retrieval services (CCITT Recommendation I.113 [7]).
+
+**3.1.5 local application:** A piece of software which is part of the (telecommunication) application and is running on the considered equipment.
+
+**3.1.6 MHEG-API:** The API provided by an MHEG engine to MHEG applications for the manipulation of MHEG objects, as defined in this Recommendation.
+
+**3.1.7 MHEG application:** A piece of software which uses the MHEG-API. An MHEG application is therefore a client of an MHEG engine.
+
+**3.1.8 MHEG engine:** A process or a set of processes that interpret MHEG objects encoded according to the encoding specifications of ISO/IEC 13522-1 [1]: Abstract Syntax Notation One (ASN.1) for Part 1, Standard Generalized Markup Language (SGML) for Part 2.
+
+**3.1.9 MHEG using application:** An application which involves the interchange of MHEG objects within itself or with another application.
+
+---
+
+<sup>1)</sup> To be published.
+
+- 3.1.10 multimedia and hypermedia application:** An application which involves the presentation of multimedia information to the user and the interactive navigation across this information by the user.
+- 3.1.11 multimedia and hypermedia information retrieval services (M&HIRS):** A generic set of services which provide users with the capability to access and interchange multimedia and hypermedia information.
+- 3.1.12 multimedia application:** An application which involves the presentation of multimedia information to the user.
+- 3.1.13 multimedia:** The property of handling several types of representation media.
+- 3.1.14 primitive:** One of the basic entry points provided by a provider module to any user module to enable the user module to access the software service(s) supplied by the provider module.
+- 3.1.15 (software) application:** A piece of software answering a set of user's requirements and for use by a computer user.
+- 3.1.16 (software) service:** A set of functions provided by a (server) software or system to a client software or system, usually accessible through an application programming interface.
+- 3.1.17 (telecommunication) application:** A set of a user's requirements (see Recommendation Q.9 [9]).
+- 3.1.18 (telecommunication) service:** That which is offered by an Administration to its customers in order to satisfy a specific telecommunication requirement (see Recommendation I.112 [8]).
+- 3.1.19 terminal application:** A piece of software running on the terminal and performing the part of the processing that is required to make the terminal appropriate for user access to the application. The terminal application is usually the 'master' module in the terminal.
+- 3.1.20 user:** A person or machine delegated by a customer to use the services and/or facilities of a telecommunication network (see Recommendation I.112 [8]).
+- 3.1.21 action (object):** An object that provides operation on objects, e.g. to change their attributes or states.
+- 3.1.22 channel:** A logical space in which rt-components are positioned for final presentation. Channels are mapped by the MHEG engine to physical devices like screen windows or loudspeaker for making the rt-objects within them perceivable by the user.
+- 3.1.23 component (object):** An abstraction which represents objects of Content or Composite type.
+- 3.1.24 composite (object):** A list of Composition Elements grouped for presentation. The presentation of a Composite object consists of the presentation of its Composition Elements.
+- 3.1.25 container (object):** A means to group objects without specifying specific relationships.
+- 3.1.26 content (object):** Encoded generic value, media or non-media data.
+- 3.1.27 descriptor (object):** A structure for the interchange of resource information about a single or a set of other interchanged objects.
+- 3.1.28 (IDL) attribute:** An identifiable association between an object and a value. An attribute **A** is made visible to clients as a pair of operations: **get\_A** and **set\_A**. Read only attributes only generate a **get** operation.
+- 3.1.29 (IDL) class:** An implementation that can be instantiated to create multiple objects with the same behaviour. An object is an instance of a class. Types classify objects according to a common implementation.
+- 3.1.30 (IDL) data type:** A categorisation of values operation arguments, typically covering both behaviour and representation (i.e. the traditional non-Object Oriented (OO) programming language notion of type).
+
+**3.1.31 (IDL) instance:** An object is an instance of an interface if it provides the operations, signatures and semantics specified by that interface. An object is an instance of an implementation if its behaviour is provided by that implementation.
+
+**3.1.32 (IDL) object:** A combination of state and a set of methods that explicitly embodies an abstraction characterised by the behaviour of the relevant requests. An object is an instance of an implementation and an interface. An object models a real-world-entity, and it is implemented as a computational entity that encapsulates state and operations (internally implemented as data and methods) and responds to requester services.
+
+**3.1.33 (IDL) operation:** A service that can be requested. An operation has an associated signature, which may restrict which actual parameters are valid.
+
+**3.1.34 interface definition language (IDL):** A language that specifies types and objects by specifying their interface. It provides a conceptual framework for describing the objects.
+
+**3.1.35 link (object):** An object which defines spatio-temporal relationships between other objects.
+
+**3.1.36 macro (object):** An object that provides the facility to replace the parameters in frequently used action objects.
+
+**3.1.37 Mh-object:** MhObjects (and their subtypes) match form b) objects as defined in ISO/IEC 13522-1: "Information technology – Coding of multimedia and hypermedia information" [1], 6.2.4, i.e. objects available to the MHEG engine.
+
+**3.1.38 (MHEG) elementary action:** An attribute of the MHEG Action class which instructs an object to perform a certain operation, e.g. to change one of its attributes or states.
+
+**3.1.39 MHEG entity:** Any MHEG object, rt-object, content data, script data, socket, channel or other construction identified or referred to in the MHEG standard.
+
+**3.1.40 MHEG interpretation service:** The service takes interchanged MHEG objects and messages issued by the presentation system as an input. It analyses this data in order to trigger the presentation of content data according to its semantics.
+
+**3.1.41 MHEG object handling service:** This facility physically creates, handles and maintains intermediate data structures necessary to implement a client access to the MHEG objects and their contents.
+
+**3.1.42 MHEG object:** A coded representation of an instance of an MHEG object class.
+
+**3.1.43 model object:** Object instantiations from the MHEG classes.
+
+**3.1.44 notification:** A primitive issued by the server on its own initiative to forward information to the client.
+
+**3.1.45 request:** A primitive issued by the client on its own initiative to forward information to the server.
+
+**3.1.46 response:** A primitive issued by the server as a reply to a request to forward information to the client.
+
+**3.1.47 rt-object:** RtObjects (and their subtypes) match form c) objects as defined in ISO/IEC 13522-1: "Information technology – Coding of multimedia and hypermedia information" [1], 6.2.4, i.e. instances of MhObjects available to the presentation process.
+
+**3.1.48 script (object):** Object that provides the structure to interchange script data in a specified encoded form.
+
+**3.1.49 socket:** An element of an rt-composite. Rt-components are plugged into sockets. Different types of sockets are defined depending on the rt-component plugged into the socket:
+
+- empty socket, i.e. a null rt-component is plugged;
+- presentable socket, i.e. an rt-content or an rt-multiplexed content is plugged;
+- structural socket, i.e. an rt-composite is plugged.
+
+## 3.2 Abbreviations
+
+This Recommendation uses the following abbreviations:
+
+|       |                                                                                  |
+|-------|----------------------------------------------------------------------------------|
+| API   | Application Programming Interface                                                |
+| ASN.1 | Abstract Syntax Notation One (as defined in ITU-T Recommendation X.208 [5])      |
+| BER   | Basic Encoding Rules (as defined in Recommendation X.209 [6])                    |
+| C1    | State period for a Channel: 'non-available'                                      |
+| C2    | State period for a Channel: 'processing'                                         |
+| C3    | State period for a Channel: 'available'                                          |
+| C4    | State period for a Channel: 'processing'                                         |
+| CCITT | Comité Consultatif International Télégraphique et Téléphonique                   |
+| CGS   | Channel Generic Space                                                            |
+| CGSU  | Channel Generic Space Unit                                                       |
+| CORBA | Common Object Request Broker Architecture                                        |
+| DIS   | Draft International Standard                                                     |
+| EBNF  | Extended Backus-Naur Form                                                        |
+| ETR   | ETSI Technical Report                                                            |
+| ETS   | European Telecommunication Standard                                              |
+| ETSI  | European Telecommunications Standards Institute                                  |
+| GSR   | Generic Spatial Ratio                                                            |
+| GTU   | Generic Temporal Unit                                                            |
+| IDL   | Interface Definition Language (as defined in ISO/IEC 14750-1 IDL [10])           |
+| IEC   | International Electrotechnical Commission                                        |
+| IOGTR | Initial Original generic space Generic Temporal Ratio                            |
+| IOV   | Initial Original audible Volume                                                  |
+| ISO   | International Organisation for Standardisation                                   |
+| ITU-T | International Telecommunication Union – Telecommunication Standardisation Sector |
+| JTC   | Joint Technical Committee                                                        |
+| MCU   | Multipoint Control Unit                                                          |
+| MHEG  | Multimedia and Hypermedia information coding Experts Group                       |
+| MPEG  | Moving Picture Experts Group                                                     |
+| O1    | State period for an mh-object: 'not ready'                                       |
+| O2    | State period for an mh-object: 'processing'                                      |
+| O3    | State period for an mh-object: 'ready'                                           |
+| O4    | State period for an mh-object: 'processing'                                      |
+| OGS   | Original Generic Space                                                           |
+| OGSU  | Original generic space Generic Spatial Unit                                      |
+| OGTR  | Original generic space Generic Temporal Ratio                                    |
+
+|       |                                                |
+|-------|------------------------------------------------|
+| OGTU  | Original generic space Generic Temporal Unit   |
+| OO    | Object Oriented                                |
+| OSI   | Open Systems Interconnection                   |
+| OV    | Original Volume                                |
+| PRGS  | Parent Relative Generic Space                  |
+| PS    | Perceptible Size                               |
+| PSAP  | Perceptible Size Attachment Point              |
+| R1    | State period for an rt-object: 'not available' |
+| R2    | State period for an rt-object: 'processing'    |
+| R3    | State period for an rt-object: 'available'     |
+| R4    | State period for an rt-object: 'processing'    |
+| RGS   | Relative Generic Space                         |
+| RGSU  | Relative generic space Generic Spatial Unit    |
+| RGTU  | Relative generic space Generic Temporal Unit   |
+| rt    | Run-time                                       |
+| SGML  | Standard Generalized Markup Language           |
+| SIR   | Script Interchange Representation              |
+| SSU   | Service Support Unit                           |
+| VD    | Visible Duration                               |
+| VS    | Visible Size                                   |
+| VSEAP | Visible Size External Attachment Point         |
+| VSGS  | Visible Size Generic Space                     |
+| VSGSU | Visible Size Generic Spatial Unit              |
+| VSIAP | Visible Size Internal Attachment Point         |
+
+## 4 Conformance
+
+An implementation of this Recommendation is an MHEG engine implementation which provides client MHEG applications with one or several language bindings of the abstract Application Programming Interface (API) defined in this Recommendation.
+
+An application of this Recommendation is an MHEG application which uses a language binding of the abstract API defined in this Recommendation to control the behaviour of an MHEG engine.
+
+The following subclauses state requirements associated with the conformance of both implementations and applications to this Recommendation.
+
+### 4.1 Implementation conformance
+
+#### 4.1.1 Conformance requirements
+
+A conforming implementation for a language binding specification for this Recommendation shall meet all of the following criteria:
+
+- 1) The implementation shall support all required behaviour defined in this Recommendation.
+
+- 2) The implementation shall support all required interfaces defined in the language binding specification. Those interfaces shall support the behaviour described in this Recommendation and in the language binding specification.
+- 3) The implementation may provide additional functions or facilities not required by this Recommendation or by the language binding specification. Each such non-standard extension shall be identified as such in the system documentation. Non-standard extensions, when used, may change the behaviour of functions or facilities defined by this Recommendation or by the language binding specification. The conformance document shall define an environment in which an application can be run with the behaviour specified by this Recommendation and the language binding specification. In no case shall such an environment require modification of a Strictly Conforming Application.
+
+#### **4.1.2 Conformance documentation**
+
+A conformance document with the following information shall be available for an implementation claiming conformance to a language binding specification for this Recommendation. The conformance document shall be in two parts. The first part shall have the same structure as this Recommendation, with the information presented in the appropriately numbered sections, clauses, and subclauses. The second part shall have the same structure as the language binding specification, with the information presented in the appropriately numbered sections, clauses, and subclauses. The conformance document shall not contain information about extended features or capabilities outside the scope of this Recommendation and the language binding specification.
+
+The conformance document shall identify the language binding specification to which the implementation conforms.
+
+The conformance document shall contain a statement that indicates the full names, numbers, and dates of the language-independent and language binding specification standards that apply.
+
+The conformance document shall state which of the optional features defined in this Recommendation and in the language binding specification are supported by the implementation.
+
+The conformance document shall describe the behaviour of the implementation for all implementation-defined features defined in this Recommendation and in the language binding specification. This requirement shall be met by listing these features and by providing either a specific reference to the system documentation or full syntax and semantics of these features. The conformance document may specify the behaviour of the implementation for those features where this Recommendation or the language binding specification states that implementations may vary or where features are identified as undefined or unspecified.
+
+No specifications other than those specified by this Recommendation and the language binding specification shall be present in the conformance document.
+
+The phrases "shall document" or "shall be documented" in this Recommendation or in a language binding specification for this Recommendation mean that documentation of the feature shall appear in the conformance document, as described previously, unless the system documentation is explicitly mentioned.
+
+The system documentation should also contain the information found in the conformance document.
+
+## **4.2 Application conformance**
+
+All applications claiming conformance to a language binding specification for this Recommendation shall fall within one of the categories defined in the following subclauses.
+
+### **4.2.1 Strictly Conforming Application**
+
+A Strictly Conforming Application is an application that requires only the mandatory facilities described in this Recommendation, in the language binding specification and in the applicable language standards. Such an application shall accept a behaviour described in this Recommendation or in the language binding specification as unspecified or implementation defined and, for symbolic constants shall accept any value in the ranges permitted by this Recommendation and the language binding specification.
+
+#### **4.2.2 Conforming Application**
+
+A Conforming Application of a language binding specification for this Recommendation is an application that differs from a Strictly Conforming Application in that it may use optional facilities described in this Recommendation, in the language binding specification and in the applicable language standards, as well as non-standard facilities that are consistent with the standard and with the language binding specification. Such an application shall fully document its requirements for these optional and extended facilities in addition to the documentation required of a Conforming Application.
+
+#### **4.3 Test Methods**
+
+Any measurement of conformance to a language binding specification for this Recommendation shall be performed using test methods that conform to Recommendation X.290 [2] and to any additional requirements that may be imposed by the language binding specification.
+
+### **5 General description**
+
+This clause situates the MHEG-API within the architecture of an MHEG using application. It then specifies and classifies the software services that the MHEG API shall provide to its client applications.
+
+#### **5.1 Functional reference model of MHEG using applications**
+
+##### **5.1.1 Reference model for multimedia applications**
+
+ETR 173 [3] "Functional Model for Multimedia Applications" and ETR 225 [4] "API and script representation for MHEG – Requirements and framework" define a generic reference model describing a functional architecture common to all multimedia applications making use of retrieval, conversational and/or distribution services. The model is applicable to all MHEG using applications.
+
+Figures 1 to 3 show how this reference model applies to MHEG using applications for terminal-to-host, terminal-to-terminal and terminal-to-database configurations in both point-to-point and multipoint communication.
+
+In an M&H architecture the following functional units can be identified:
+
+- 1) presentation agent;
+- 2) access agent;
+- 3) local application interpreter;
+- 4) MHEG engine;
+- 5) local information base.
+
+In an M&H architecture the following Interfaces (APIs) can be identified:
+
+- 1) the services of the presentation agent are offered through the presentation API;
+- 2) the services of the MHEG engine are offered through the MHEG-API;
+- 3) the services of the access agent are offered through the access API.
+
+In an M&H architecture the following end-to-end protocols can be identified:
+
+- 1) End-to-end protocol between an application – Distant MHEG engine.
+- 2) End-to-end protocol between an application – Service support function.
+- 3) End-to-end protocol between an access agent – Access agent.
+
+For a "terminal-to-host and database", configuration, the host may use the end-to-end protocol between access agents to reference objects or contents at the database. The database has the same structure as shown in Figure 3.
+
+For a terminal-to-host architecture, the Service Support Unit (SSU) to which the terminal may be connected, may also enable the user to select between different applications. The host is connected to the SSU via the host access network.
+
+![Application architecture reference model for terminal-to-host configurations. The diagram shows three main components: Block Host, Block Network, and Block Terminal, all within a System Terminal_to_Host boundary. Block Host contains MHEG_Engine (1,1), AccessAgent (1,1), and LocalInfoBase (1,1). Block Network contains ServiceSupportUnit (1,). Block Terminal contains LocalApplication (1,1), AccessAgent (1,1), LocalInfoBase (1,1), MHEG_Engine (1,1), and PresentationAgent (1,1). Arrows indicate data flow and dependencies between these components.](9c6461e1e94afae4dec455e69a2ce152_img.jpg)
+
+System Terminal\_to\_Host
+
+```
+
+graph TD
+    subgraph System_Terminal_to_Host [System Terminal_to_Host]
+        subgraph Block_Host [Block Host]
+            MHEG_Engine_H["MHEG_Engine (1,1)"]
+            AccessAgent_H["AccessAgent (1,1)"]
+            LocalInfoBase_H["LocalInfoBase (1,1)"]
+            LocalApplication_H["LocalApplication (1,1)"]
+            MHEG_Engine_H <--> AccessAgent_H
+            AccessAgent_H <--> LocalInfoBase_H
+            LocalApplication_H <--> AccessAgent_H
+        end
+
+        subgraph Block_Network [Block Network]
+            ServiceSupportUnit["ServiceSupportUnit (1,)"]
+        end
+
+        subgraph Block_Terminal [Block Terminal]
+            LocalApplication_T["LocalApplication (1,1)"]
+            AccessAgent_T["AccessAgent (1,1)"]
+            LocalInfoBase_T["LocalInfoBase (1,1)"]
+            MHEG_Engine_T["MHEG_Engine (1,1)"]
+            PresentationAgent_T["PresentationAgent (1,1)"]
+            LocalApplication_T <--> AccessAgent_T
+            AccessAgent_T <--> LocalInfoBase_T
+            MHEG_Engine_T <--> AccessAgent_T
+            MHEG_Engine_T <--> PresentationAgent_T
+            PresentationAgent_T <--> AccessAgent_T
+        end
+
+        Block_Host <--> Block_Network
+        Block_Network <--> Block_Terminal
+        LocalApplication_H <--> LocalApplication_T
+        LocalInfoBase_H <--> LocalInfoBase_T
+        MHEG_Engine_H <--> MHEG_Engine_T
+        PresentationAgent_T <--> PresentationAgent_H
+    end
+
+```
+
+The diagram illustrates the application architecture reference model for terminal-to-host configurations. It is organized into three main sections within a larger container labeled "System Terminal\_to\_Host":
+
+- Block Host:** Contains three components: MHEG\_Engine (1,1), AccessAgent (1,1), and LocalInfoBase (1,1). MHEG\_Engine (1,1) and AccessAgent (1,1) are connected by a bidirectional arrow. AccessAgent (1,1) and LocalInfoBase (1,1) are also connected by a bidirectional arrow. LocalApplication (1,1) is connected to AccessAgent (1,1) by a bidirectional arrow.
+- Block Network:** Contains a single component: ServiceSupportUnit (1,). It is connected to the Block Host and Block Terminal by bidirectional arrows.
+- Block Terminal:** Contains five components: LocalApplication (1,1), AccessAgent (1,1), LocalInfoBase (1,1), MHEG\_Engine (1,1), and PresentationAgent (1,1). LocalApplication (1,1) and AccessAgent (1,1) are connected by a bidirectional arrow. AccessAgent (1,1) and LocalInfoBase (1,1) are connected by a bidirectional arrow. MHEG\_Engine (1,1) and AccessAgent (1,1) are connected by a bidirectional arrow. MHEG\_Engine (1,1) and PresentationAgent (1,1) are connected by a bidirectional arrow. PresentationAgent (1,1) and AccessAgent (1,1) are connected by a bidirectional arrow.
+
+External connections are shown as follows:
+
+- A bidirectional arrow connects the Block Host and Block Network.
+- A bidirectional arrow connects the Block Network and Block Terminal.
+- A bidirectional arrow connects the LocalApplication (1,1) in the Block Host to the LocalApplication (1,1) in the Block Terminal.
+- A bidirectional arrow connects the LocalInfoBase (1,1) in the Block Host to the LocalInfoBase (1,1) in the Block Terminal.
+- A bidirectional arrow connects the MHEG\_Engine (1,1) in the Block Host to the MHEG\_Engine (1,1) in the Block Terminal.
+- A bidirectional arrow connects the PresentationAgent (1,1) in the Block Terminal to the PresentationAgent (1,1) in the Block Host.
+
+T0825160-95/d01
+
+Application architecture reference model for terminal-to-host configurations. The diagram shows three main components: Block Host, Block Network, and Block Terminal, all within a System Terminal\_to\_Host boundary. Block Host contains MHEG\_Engine (1,1), AccessAgent (1,1), and LocalInfoBase (1,1). Block Network contains ServiceSupportUnit (1,). Block Terminal contains LocalApplication (1,1), AccessAgent (1,1), LocalInfoBase (1,1), MHEG\_Engine (1,1), and PresentationAgent (1,1). Arrows indicate data flow and dependencies between these components.
+
+Figure 1/T.174 – Application architecture reference model for terminal-to-host configurations
+
+![Figure 2/T.174 – Application architecture reference model for terminal-to-terminal configurations. The diagram shows a System Terminal_to_Terminal container with two Block Terminal blocks and a central Block Network block. Each Block Terminal contains PresentationAgent, MHEG_Engine, LocalApplication, and LocalInfoBase components. The Block Network contains a ServiceSupportUnit component. Arrows indicate data flow and dependencies between components and the system boundary.](b6671cfafda3820aafe9a24fa7a4d8c7_img.jpg)
+
+The diagram illustrates the application architecture reference model for terminal-to-terminal configurations, enclosed within a large box labeled "System Terminal\_to\_Terminal".
+
+**Block Terminal (Top):**
+
+- Contains components: **PresentationAgent (1,1)**, **MHEG\_Engine (1,1)**, **LocalApplication (1,1)**, and **AccessAgent (1,1)**.
+- LocalInfoBase (1,1)** is also present but not directly connected to the other components within this block.
+- Interactions:
+  - PresentationAgent** and **MHEG\_Engine** are connected by a bidirectional arrow.
+  - MHEG\_Engine** and **LocalApplication** are connected by a bidirectional arrow.
+  - LocalApplication** and **AccessAgent** are connected by a bidirectional arrow.
+  - AccessAgent** and **LocalInfoBase** are connected by a bidirectional arrow.
+  - AccessAgent** has a unidirectional arrow pointing to **PresentationAgent**.
+
+**Block Network:**
+
+- Contains the component: **ServiceSupportUnit (1,)**.
+- It is connected to the top **Block Terminal** and the bottom **Block Terminal** via bidirectional arrows.
+
+**Block Terminal (Bottom):**
+
+- Contains components: **LocalApplication (1,1)**, **MHEG\_Engine (1,1)**, **PresentationAgent (1,1)**, and **AccessAgent (1,1)**.
+- LocalInfoBase (1,1)** is also present but not directly connected to the other components within this block.
+- Interactions:
+  - LocalApplication** and **AccessAgent** are connected by a bidirectional arrow.
+  - AccessAgent** and **LocalInfoBase** are connected by a bidirectional arrow.
+  - AccessAgent** has a unidirectional arrow pointing to **PresentationAgent**.
+  - MHEG\_Engine** and **PresentationAgent** are connected by a bidirectional arrow.
+
+**System Boundary:**
+
+- The entire architecture is enclosed in a box labeled "System Terminal\_to\_Terminal".
+- Arrows indicate the flow of data and control between the components and the system boundary.
+
+Figure 2/T.174 – Application architecture reference model for terminal-to-terminal configurations. The diagram shows a System Terminal\_to\_Terminal container with two Block Terminal blocks and a central Block Network block. Each Block Terminal contains PresentationAgent, MHEG\_Engine, LocalApplication, and LocalInfoBase components. The Block Network contains a ServiceSupportUnit component. Arrows indicate data flow and dependencies between components and the system boundary.
+
+T0825170-95/d02
+
+**Figure 2/T.174 – Application architecture reference model for terminal-to-terminal configurations**
+
+For a terminal-to-terminal architecture, the SSU to which all terminals are connected may be a Multipoint Control Unit (MCU) that controls and manages the application and the different terminals. The end-to-end protocol between an application and a distant MHEG engine is applicable to all terminals. Each terminal application can use the protocol to communicate with each other terminal engine.
+
+For a "terminal-to-database" or "terminal-to-host and database" structure, the database may mainly consist of an access agent used to locate the referenced objects.
+
+The **presentation agent** provides a multimedia content presentation service. It manages the presentation of monomedia data, performs data format decoding and manages the user interaction. It also acts as interface to external devices like smart card readers, VCRs, etc. The presentation agent is accessed by its clients (here the MHEG engine) through the "presentation API" which isolates the software on higher level from the specific features of the various hardware sub-platforms. The presentation agent is only present on a terminal.
+
+The **access agent** provides MHEG object and multimedia content location, access and communication services. It makes the location of the various objects (multimedia contents, MHEG objects, scripts, application specific data) transparent to its clients, i.e. the processes trying to access these objects. When an object is requested, the access agent is able first to locate it (possibly by issuing requests to directory services), then to retrieve it from local or distant storage (possibly by issuing requests to repository services and remote equipments), finally to provide access to it (possibly by using MHEG object and content encoding/decoding services). In the reverse way, the access agent also handles the forwarding of objects to remote equipments, their registration in directories and their storage in repositories.
+
+The **local application** manages the logic of the application on a given platform. The application itself will often be distributed between several platforms (terminals, hosts). The local application is a client of the access agent via the access API, of the MHEG engine via the MHEG-API and of the presentation agent via the presentation API. The local application may make use of a script execution service provided by a script processor. Scripts are parts of the application which are interchanged during the course of an application. A script processor is a functional unit able to execute scripts, it may be the script itself (if interchanged in executable form), a script language interpreter or an MHEG Script Interchange Representation (SIR) interpreter.
+
+The **MHEG engine** provides an MHEG interpretation service. It interprets MHEG objects, manages links between them, triggers actions and orders objects presentation and access. It is controlled by the application through the MHEG-API.
+
+The **local information base** may be used to store objects, contents, scripts, etc. permanently or temporarily on the device. No assumption is made on how those objects are stored and which physical storage device is used.
+
+The **presentation API** allows the terminal MHEG engine to access the multimedia content presentation service provided by a presentation agent.
+
+The **MHEG-API** allows MHEG applications to access the MHEG interpretation service provided by an MHEG engine. The MHEG-API client application may be either the local application, or it may run on a remote device. If the application is running on a remote device, it may access the MHEG-API using the end-to-end protocol "application – distant MHEG engine" (9). The MHEG-API is specified in this Recommendation.
+
+The **access API** allows processes (e.g. local application, script interpreter, MHEG engine, presentation agent) to access the MHEG object and multimedia content location, access and communication services provided by an access agent.
+
+The **service support unit** is a functional unit that handles service specific control parameters and offers functionality that depends on the particular service. An example for a service support unit is the MCU in the case of Videoconferencing service. The functionality handled by the service support unit is service-specific.
+
+The **end-to-end protocol "application – distant MHEG engine"** allows an application running on a distant device to communicate with a local MHEG engine. This protocol enables the implementation of terminal-to-host configurations.
+
+The **end-to-end protocol "application – service support unit"** enables the use of the services provided by the service provider by the terminal application or the user respectively.
+
+The **end-to-end protocol "access agent – access agent"** enables the handling, maintenance and exchange of objects and data in a distributed environment.
+
+### 5.1.2 The MHEG-API
+
+This subclause describes the terminology applicable to the MHEG-API.
+
+The MHEG-API is the interface through which an MHEG application is allowed to control an MHEG engine.
+
+![Diagram of the MHEG-API interface showing the flow between an MHEG Application and an MHEG engine.](7d3d5fb5d09c0cd35a9d637be241651e_img.jpg)
+
+The diagram illustrates the MHEG-API interface. It consists of two main components: the **MHEG Application** at the top and the **MHEG engine** at the bottom. A horizontal line separates them, labeled **MHEG-API** on the right. A vertical line connects the two components. On this vertical line, there are two arrows: one pointing upwards from the MHEG engine to the MHEG Application, labeled **Response Notification**, and one pointing downwards from the MHEG Application to the MHEG engine, labeled **Request**. The identifier **T0825190-95/d04** is located at the bottom right of the diagram.
+
+Diagram of the MHEG-API interface showing the flow between an MHEG Application and an MHEG engine.
+
+**Figure 4/T.174 – The MHEG-API**
+
+An API consists of **primitives**, i.e. basic entry points provided by a **provider** module to any **user** module to enable the user to access **software services** supplied by the provider. These modules are pieces of software, although they can use services provided by computer hardware or other electronic equipment.
+
+The **MHEG-API** gives access to **MHEG interpretation** and (optionally) **MHEG object access** services. **MHEG engines** are the providers, whereas **MHEG applications** are the users. One MHEG engine may provide its software services to several applications. An MHEG engine can therefore be viewed as a **server**, whereas MHEG applications are the **clients** of the software services.
+
+An API primitive is used to transfer some information between its user and its provider. This information consists of control and/or data. The information may be forwarded either from a client to its server or from the server to one of its clients. The information may be generated by its sender either on its own initiative or as a reply to a formerly issued primitive. The following terms are used:
+
+- a **request** is a primitive issued by the client on its own initiative to forward information to the server;
+- a **response** is a primitive issued by the server as a reply to a request to forward information to the client;
+- a **notification** is a primitive issued by the server on its own initiative to forward information to the server.
+
+Different kinds of requests may be considered:
+
+- requests that require no response are called **asynchronous requests**;
+- requests that do not require an immediate response are called **deferred synchronous requests**;
+- requests that require an immediate response, until which the client process cannot proceed, are called **synchronous requests**.
+
+Whether synchronous or asynchronous, requests may result in processing that will, in turn, trigger notifications.
+
+## 5.2 Functional specification of the MHEG-API
+
+### 5.2.1 MHEG usage specifications
+
+This subclause introduces MHEG usage rules. They consist of clarifications and interpretations of the MHEG standard regarding the definition of the main entities addressed by the MHEG standard that may be handled in MHEG using applications.
+
+A clear understanding of the MHEG-related entities implies a formal definition of the identity of the entities that are handled and/or transformed by components of an MHEG using application, as well of how they can be identified or referenced within different components.
+
+#### 5.2.1.1 Definitions
+
+These subclauses introduce the concepts of identity, identification and referencing. The following precisions bring additional semantics with regard to the MHEG standard (which makes no clear distinction between reference and identification), and are applicable as definitions throughout this Recommendation.
+
+The identity of an object is itself. The identity function is defined by  $\text{Identity}(A) = A$ . Any object has an identity. Objects A and B have the same identity if, and only if, A and B are the same object.
+
+The identification of an object is an unambiguous way to determine its identity. If objects A and B have the same identifier, then they have the same identity, i.e. they are the same object. The identifier is often, but not necessarily, contained in the object. Objects may have several identification modes (with different types of identifier), though this is neither a useful nor recommended policy. If an object has no identifier, then it cannot be identified, although it has an identity.
+
+Referencing an object is a convenient way to associate a name with an object. To determine the object which is referenced, the object reference has to be resolved by some process. One reference may only reference one object at a given time, but one object may be referenced in many ways. Unlike its identifier, references to an object are therefore not guaranteed to be unique. Moreover, it is possible to reference objects which otherwise are not identifiable.
+
+#### 5.2.1.2 MHEG objects
+
+According to the MHEG standard, an MHEG object is defined as a coded representation. Therefore, MHEG objects are bitstrings. The identity of an MHEG object is its bitstring. MHEG objects are 'form a' objects as described in the MHEG standard, 6.2.4. MHEG object A and MHEG object B are identical if and only if they **are** the same sequence of bits.
+
+An MHEG object is not a physical object, but rather an abstraction (a specified sequence of bits) which may have many representations (i.e. different objects) of different types: interchanged MHEG objects, stored MHEG objects, mh-objects, etc. Such representations are handled by different software services.
+
+An MHEG object may be identified by an MHEG identifier. MHEG identifiers are the **only** way to identify MHEG objects. The structure and coded representation of MHEG identifiers is defined by the MHEG standard. The MHEG identifier of an MHEG object must be encoded inside the MHEG object. Since the attribute is optional, some MHEG objects do not have an MHEG identifier. Such MHEG objects cannot be identified. The MHEG standard imposes a constraint on the design of MHEG-using applications which is that MHEG object A and MHEG object B shall not have the same MHEG identifier unless they are identical.
+
+The MHEG generic reference describes all possible ways to reference an MHEG object.
+
+#### 5.2.1.3 Mh-objects
+
+An mh-object is an internal representation of an MHEG object within a process or system. An mh-object is not an MHEG object. Within an MHEG engine, mh-objects represent 'available' MHEG objects. Mh-objects are 'form b' objects as described in the MHEG standard, 6.2.4. An mh-object represents one MHEG object, i.e. there is always a bitstring that corresponds to an mh-object. An MHEG engine shall not handle more than one mh-object to represent one MHEG object.
+
+As a consequence, mh-objects handled by MHEG engines may be identified using MHEG identifiers. In addition, other mechanisms for identifying mh-objects (e.g. symbolic identification) may be defined by the application, provided their internal representation allows for it. This is especially useful when some of the MHEG objects represented by an MHEG engine's mh-objects are non-identifiable, i.e. have no MHEG identifier. This allows to guarantee that all mh-objects shall be identifiable.
+
+Mh-objects are referenced the same way MHEG objects are. References to MHEG objects for which the MHEG engine handles an mh-object will usually be resolved by addressing this mh-object.
+
+#### 5.2.1.4 Rt-objects
+
+An rt-object is a run-time 'instance' (or copy) of a 'model' mh-object, which is created and handled by an MHEG engine in the purpose of presentation. An rt-object is not an MHEG object. Within an MHEG engine, rt-objects represent 'rt-available' MHEG objects. Rt-objects are 'form c' objects as described in the MHEG standard, 6.2.4. There may be none or several rt-objects which are 'presentable' copies of one mh-object. An rt-object always has exactly one mh-object as its model.
+
+Rt-objects may be identified using rt-object identifiers whose 'model object identification' part is an MHEG identifier. The structure and coded representation of rt-object identifiers are defined by the MHEG standard. In addition, other mechanisms for identifying mh-objects (e.g. symbolic identification) may be defined by the application, provided their internal representation allows for it. This is especially useful when some of the MHEG objects represented by an MHEG engine's mh-objects used as models for rt-objects are non-identifiable, i.e. have no MHEG identifier. This allows to guarantee that all rt-objects shall be identifiable.
+
+Rt-objects may be referenced using MHEG generic references.
+
+#### 5.2.1.5 Channels
+
+Channels are objects defined by the MHEG standard and handled by the MHEG engines. They may be identified using channel identifiers.
+
+#### 5.2.1.6 Interchanged MHEG objects
+
+Interchanged MHEG objects are representations of MHEG objects which are being communicated at a given point in time using a network or storage medium. One given MHEG object (i.e. bitstring) may be interchanged many times between many places, i.e. represented by many interchanged MHEG objects. An MHEG external identifier may identify an interchanged MHEG object, and therefore reference an MHEG object through its location and time of interchange. However, it should be noted that an MHEG external identifier may not actually identify an MHEG object.
+
+Stored MHEG objects are representations of MHEG objects which are usually located in files or database records. For instance, one given MHEG object (i.e. bitstring) may be stored in many places, i.e. represented by many stored MHEG objects. Such locations are usually identified using file names or database identifiers. An MHEG external identifier may identify a storage location for an MHEG object, and therefore reference an MHEG object through its storage location.
+
+### 5.2.2 Description of MHEG-related services
+
+This subclause introduces the concept of MHEG-related services, i.e. common use software services allowing to handle MHEG-related entities. These services are provided by the building blocks (components) of the MHEG using application architecture upon which the MHEG application is built. Clients and services do not necessarily know each other and may be related through a mediating entity. In this building blocks approach, implementations of the services make use of each other.
+
+An MHEG application may make use of some or all of these following MHEG-related services:
+
+- the **MHEG interpretation service** allows to control the behaviour of an MHEG engine, i.e. the interpretation and presentation of MHEG objects;
+- the **MHEG object access service** allows to access and modify the attributes of 'logical' MHEG objects;
+- the **MHEG object communication service** allows to transfer MHEG objects between locations;
+
+- the **MHEG object location service** allows to manage and resolve references to MHEG objects;
+- the **MHEG object handling service** allows to manage access to and interchange of physical MHEG objects;
+- the **MHEG object storage service** allows to store MHEG object bitstrings and access them;
+- the **MHEG object encoding/decoding service** allows to encode or decode MHEG objects;
+- additional services for real-time distribution, presentation and production of MHEG objects and contents may be considered.
+
+Different kinds of MHEG-related entities, bearing strong relationships with each other but being nevertheless of different types (therefore not comparable), are being handled by these software services:
+
+- the MHEG interpretation service handles rt-objects, sockets, channels and mh-objects;
+- the MHEG object access service handles mh-objects;
+- the MHEG object handling service 'handles' MHEG objects. Since MHEG objects are virtual rather than physical objects, this service relies on services that handle physical 'representations' of MHEG objects, such as storage or transport services;
+- the MHEG object location service handles MHEG generic references. Through the use of maps, it is able to resolve such references, i.e. translate them into identifiers understandable by the requesting application;
+- the MHEG object communication service handles interchanged MHEG objects;
+- the MHEG object storage service handles stored MHEG objects and manages MHEG object storage locations, whose type depend on the underlying storage mechanism, e.g. files, database records;
+- the MHEG object encoding/decoding service provides functions for transforming mh-objects into MHEG objects and vice versa.
+
+The MHEG-API consists of the interface provided by the following services, that shall be provided by Conforming MHEG engines:
+
+- the MHEG interpretation service (mandatory);
+- the MHEG object access service (optional).
+
+## 6 API definition principles
+
+### 6.1 Satisfaction of technical requirements on the MHEG-API
+
+Following the recommendations of ISO/IEC JTC 1 N 2965 [11]: "Guidelines for JTC 1 API Standardisation", the MHEG-API is defined as an abstract API specification, i.e. a language-independent description of the semantics of a set of functionality in an abstract syntax using abstract data types.
+
+Following the recommendations of ETR 225, the MHEG-API standard should meet the following requirements:
+
+- portability;
+- genericity;
+- conformance testability;
+- implementability.
+
+The **portability** requirement states that the MHEG-API standard should enable MHEG applications to use the MHEG object manipulation and interchange service provided by MHEG engines in a way independent of:
+
+- the programming language used for the MHEG application;
+- the underlying operating system.
+
+This Recommendation meets the portability requirement by the definition of an abstract API specification.
+
+The **genericity** requirement states that the MHEG-API standard should provide appropriate support to cover all the common requirements of MHEG applications.
+
+This Recommendation meets the genericity requirement through defining the MHEG-API at the most basic level, e.g. by defining primitives that match MHEG elementary actions and data types that match MHEG data types. This guarantees to maximise the range of MHEG object manipulations made available to applications.
+
+The **conformance testability** requirement states that the MHEG-API standard should make it as easy as possible to ensure the conformance of MHEG engines to the MHEG-API standard, i.e. the correct provision of this API by an MHEG engine under test as well as the conformance of MHEG applications to the MHEG-API standard, i.e. the correct use of this API by an MHEG application under test.
+
+This Recommendation meets the conformance testability requirement by formal expression of the requirements on conforming implementations and conforming applications, as well as by the use of a formal description technique for the definition of the MHEG-API.
+
+The **implementability** requirement states that the MHEG-API standard should take into account simplicity and clarity both in the definition and the formulation to make implementation of conforming MHEG engines as easy as possible.
+
+This Recommendation meets the implementability requirement by the provision of informative guidelines to deduce language binding specifications and message encoding rules from the abstract API specification.
+
+## 6.2 Use of Interface Definition Language (IDL) ISO/IEC 14750 [10]
+
+The MHEG-API is defined using IDL.
+
+### 6.2.1 Comprehensive introduction to IDL
+
+IDL is a formal description technique for specifying the services provided by objects for use by applications or other objects. Although object-oriented communication in distributed environments is actually a technology of some relevance with regard to the definition of a multimedia core toolbox, this Recommendation only considers the use of IDL and its underlying object model as a context-independent formal description technique for the specification of APIs.
+
+Application of IDL should be based on an underlying object model. Such an object model is defined in terms of **object types** which support **operations** characterising the behaviour of objects. **Objects** are instances of object types. Objects may be identified using **object references**. **Non-object types** can be instantiated but do not support operations. Operations are defined by a **signature** consisting of a name, a list of input or output **parameter** types and a list of **result** types. The set of operation signatures defined for a type is the **interface** of that type. **Subtyping** allows to define type hierarchies, with subtypes providing their supertypes' interface as a part of their own interface. **Operation requests** may have different operational semantics such as synchronous, asynchronous, etc. Consequences of an operation request include side effects, results and **exceptions**.
+
+IDL is the language used to describe the interfaces (i.e. the set of operations) provided by objects. It consists of lexical conventions, preprocessing directives and an Extended Backus-Naur Form (EBNF) grammar. An IDL specification of an API consists of data type definitions, constant definitions, exception definitions, interface definitions and module definitions.
+
+### 6.2.2 The Interface Definition Language
+
+This subclause describes the main concepts that are necessary to the understanding of the MHEG-API definition.
+
+The object model provides an organised representation of objects concepts and terminology. It defines a partial model for computation that embodies the key characteristics of objects as realised by the presented technologies.
+
+The object model presented in this Recommendation is abstract in that it is not directly realised by any particular technology.
+
+An objects system provides services to its clients. A client of a service is any entity capable of requesting the service.
+
+#### 6.2.2.1 Objects
+
+An object system includes entities known as objects. An object is an identifiable, encapsulated entity that provides one or more services that can be requested by a client.
+
+#### 6.2.2.2 Requests
+
+Clients request services by issuing requests. A request is an event, i.e. something that occurs at a particular time. The information associated with a request consists of an operation, a target object, zero or more (actual) parameters, and an optional request context.
+
+A *request form* is a description or pattern that can be evaluated or performed multiple times to cause the issuing of requests.
+
+A *value* is anything that may be a legitimate (actual) parameter in a request. A value may identify an object, for the purpose of performing the request. A value that identifies an object is called object name.
+
+An *object reference* that reliably denotes a particular object. Specifically, an object reference will identify the same object each time the reference is used in a request (subject to certain pragmatic limit in space and time). An object may be denoted by multiple, distinct object references.
+
+A request may have parameters that are used to pass data to the target object; it may also have a request context which provides additional information about the request.
+
+A request causes a service to be performed on behalf of the client. One outcome of performing a service is returning to the client the results, if any, defined for the request.
+
+If an abnormal condition occurs during the performance of a request, an *exception* is returned. The exception may carry additional return parameters particular to the exception.
+
+The request parameters are identified by position. A parameter may be an input parameter, an output parameter, or an input-output parameter. A request may also return a single result value, as well as any output parameters.
+
+The following semantics holds for all requests:
+
+- any aliasing of parameter values is neither guaranteed removed nor guaranteed preserved;
+- the order in which aliased output parameters are written is not guaranteed;
+- any output parameters are undefined if an exception is returned;
+- the values which may be returned in an input-output parameter may be constrained by the value which was input.
+
+#### 6.2.2.3 Types
+
+A type is an identifiable with an associated predicate (a single-argument mathematical function with a boolean result) defined over values. A value satisfies a type if the predicate is true for that value. A value that satisfies a type is called *member of the type*.
+
+Types are used in signatures to restrict a possible parameter or to characterise a possible result.
+
+The *extension* of the type is the set of values that satisfy the type at any particular time.
+
+An object type is a type whose members are objects (literally, values that identify objects). In other words, an object type is satisfied only by (values that identify) objects.
+
+#### 6.2.2.4 Interfaces
+
+An *interface* is a description of a set of possible operations that a client may request of an object. An object satisfies an interface if it can be specified as target object in each potential request described by the interface.
+
+An *interface type* is a type that is satisfied by any object (literally, any value that identifies an object) that satisfies a particular interface.
+
+#### 6.2.2.5 Operations
+
+An *operation* is an identifiable entity that denotes a service that can be requested.
+
+An operation is identified by an *operation identifier*. An operation is not a value.
+
+An operation has a signature that describes the legitimate values of request parameters and returned results. In particular a signature consists of:
+
+- a specification of parameters required in requests for that operation;
+- a specification of the results of the operations;
+- a specification of the exceptions that may be raised by a request for the operation and the types of parameters accompanying them;
+- a specification of additional contextual information that may affect the request;
+- an indication of the execution semantics the client should expect from a request for the operation.
+
+A *parameter* is characterised by its mode and its type. The mode indicates whether the value should be passed from the client to the server (in), from the server to the client (out), or both (in-out). The parameter's type constrains the possible value which may be passed in the direction(s) dictated by the mode.
+
+The *return result* is a distinguished out parameter.
+
+An *exception* is an indication that an operation request was not performed successfully. An exception may be accompanied by additional exception-specific information.
+
+A *request context* provides additional, operation-specific information that may effect the performance of a request.
+
+Two styles of *execution semantics* are defined by the object model:
+
+- At-most-once: If an operation request returns successfully, it was performed exactly once; if it returns an exception indication, it was performed at most once.
+- Best-effort: A best-effort operation is a request-only operation, i.e. it cannot return any results and the requester never synchronises with the completion, if any, of the request.
+
+The execution semantics to be expected are associated with an operation. This prevents a client and object implementation from assuming different execution semantics.
+
+Note that the client is able to invoke an at-most-once operation in a synchronous or deferred-synchronous manner.
+
+#### 6.2.2.6 Attributes
+
+An interface may have attributes. An attribute is logically equivalent to declaring a pair of accessor functions: one to retrieve the value of the attribute and one to set the value of the attribute.
+
+An attribute may be read-only, in which case only the retrieval accessor function is defined.
+
+#### 6.2.2.7 Subtyping versus inheritance
+
+Subtyping is a relationship between types based on their interfaces. It defines the rules by which objects of one type are determined to be acceptable in contexts expecting another type. Inheritance is a mechanism for reuse. Many object systems do not distinguish between subtyping and inheritance. The following subclause defines the two concepts separately, but then explicitly states how they are related.
+
+### 6.2.2.8 Subtyping
+
+The object model supports subtyping for object types. Intuitively, one type is a subtype of another if the first is a specialisation or refinement of the second. Operationally it means that any object of the first type can be used in any context that expects an object of the second type; that is, if S is a subtype of T, an object of type S may be used wherever an object of type T may be used. In other words, objects of type S are also of type T. Subtypes can have multiple parent types, with the implication that an object that is an instance of type S is also an instance of all supertypes of type S. The relationships between types define a type hierarchy, which can be drawn as a directed acyclic graph.
+
+### 6.2.2.9 Inheritance
+
+Inheritance is a notational mechanism for defining a type S in terms of another type T. The definition of S inherits all the operations of T and may provide other operations. Intuitively, inherits means that the operations defined for T are also defined for or can be used by S. Subtyping is a relationship between interfaces (types). Inheritance can apply to both interfaces and implementations; that is both interfaces and implementations can be inherited. The object model is concerned with inheritance of interfaces. It does not specify what can happen with implementations of inherited operations (for example, whether they may be changed or overridden by a subtype).
+
+## 6.2.3 Principles for mapping IDL interfaces to API primitives
+
+The MHEG engine interface consists of a set of API primitives that can be organised into clusters according to the target entity of a primitive. Definition of this interface can therefore logically be structured according to the operation provider. In the MHEG-API context, objects that provide interfaces need not be implemented as separate object implementations. More likely, they would be internal entities handled by the MHEG engine. As for the MHEG standard, the MHEG-API definition follows an object-oriented methodology without requiring the implementations to use object-oriented design or programming techniques.
+
+Services are defined not as the interface that a module should provide but as a set of operations conspiring to offer a service, to which clients should have access.
+
+The MHEG-API therefore consists of IDL interface objects which provide operations that map API primitives. The object instance on which an operation is requested corresponds to the main (target) parameter of the API primitive.
+
+## 6.2.4 Fulfilment of technical requirements
+
+The use of IDL contributes to the fulfilment of the portability and implementability technical requirements:
+
+- IDL is independent from a programming language. Moreover, publicly available specifications for IDL language binding to C and C++ exist, and others are under study;
+- IDL provides a complete formal description language which allows a very concise, readable and efficient specification of the MHEG-API. Moreover, this formal description language is also appropriate for automatic compilation, which means that MHEG-API implementations could be automatically generated for a given language and operating system using appropriate IDL compilers. This, of course, could be a major element in facilitating implementability and general use of the standard API rather than any specific interface.
+
+## 6.3 Overview of the API definition and general principles
+
+### 6.3.1 The MHEG-API Object model
+
+This subclause presents the object model, i.e. the object types (interfaces) provided by the MHEG-API and their subtyping relationships.
+
+It may be noted that the objects described hereafter are introduced as useful concepts for specifying the interface, but are not required to be implemented as separate objects. The MHEG-API is specified as an abstract API in terms of operations provided by objects, but implementations of the MHEG-API will be provided by MHEG engine implementations.
+
+![UML class diagram showing the object model for MHEG. The diagram is divided into two main sections: MhObjects and RtObjects. The MhObjects section shows a hierarchy starting with MHEGEngine, EntityManager, and Entity. Entity is a base class for MhObject and Channel. MhObject is a base class for MhAction, MhLink, MhModel, MhContainer, and MhDescriptor. MhModel is a base class for MhComponent and MhScript. MhComponent is a base class for MhGenericContent and MhComposite. MhGenericContent is a base class for MhContent and MhMultiplexedContent. A notation box shows a Super-class with three Sub-classes (Sub-class 1, Sub-class 2, Sub-class 3). The RtObjects section shows a similar hierarchy for real-time objects: RtObjectOrSocket is a base class for RtObject and Socket. RtObject is a base class for RtScript, RtComponent, RtComposite, RtGenericContent, RtContent, and RtMultiplexedContent. RtComponentOrSocket is a base class for RtComponent and Socket. RtCompositeOrStructuralSocket is a base class for RtComposite and StructuralSocket. RtGenericContentOrPresentableSocket is a base class for RtGenericContent and GenericPresentableSocket. RtContentOrPresentableSocket is a base class for RtContent and PresentableSocket. RtMultiplexedContentOrPresentableSocket is a base class for RtMultiplexedContent and MultiplexedPresentableSocket. The diagram is labeled T0825200-95/d05.](11edb7fcedf09ac6a817f8d7b8c61eec_img.jpg)
+
+```
+
+classDiagram
+    class MHEGEngine
+    class EntityManager
+    class Entity
+    class MhObject
+    class Channel
+    class MhAction
+    class MhLink
+    class MhModel
+    class MhContainer
+    class MhDescriptor
+    class MhComponent
+    class MhScript
+    class MhGenericContent
+    class MhComposite
+    class MhContent
+    class MhMultiplexedContent
+    class RtObjectOrSocket
+    class RtObject
+    class Socket
+    class RtScript
+    class RtComponentOrSocket
+    class RtComponent
+    class RtCompositeOrStructuralSocket
+    class StructuralSocket
+    class RtGenericContentOrPresentableSocket
+    class GenericPresentableSocket
+    class RtContentOrPresentableSocket
+    class PresentableSocket
+    class RtMultiplexedContentOrPresentableSocket
+    class MultiplexedPresentableSocket
+
+    MHEGEngine --> EntityManager
+    EntityManager --> Entity
+    Entity <|-- MhObject
+    Entity <|-- Channel
+    MhObject <|-- MhAction
+    MhObject <|-- MhLink
+    MhObject <|-- MhModel
+    MhObject <|-- MhContainer
+    MhObject <|-- MhDescriptor
+    MhModel <|-- MhComponent
+    MhModel <|-- MhScript
+    MhComponent <|-- MhGenericContent
+    MhComponent <|-- MhComposite
+    MhGenericContent <|-- MhContent
+    MhGenericContent <|-- MhMultiplexedContent
+
+    RtObjectOrSocket <|-- RtObject
+    RtObjectOrSocket <|-- Socket
+    RtObject <|-- RtScript
+    RtObject <|-- RtComponent
+    RtObject <|-- RtComposite
+    RtObject <|-- RtGenericContent
+    RtObject <|-- RtContent
+    RtObject <|-- RtMultiplexedContent
+    RtComponent <|-- RtComponentOrSocket
+    RtComponentOrSocket <|-- Socket
+    RtComposite <|-- RtCompositeOrStructuralSocket
+    RtCompositeOrStructuralSocket <|-- StructuralSocket
+    RtGenericContent <|-- RtGenericContentOrPresentableSocket
+    RtGenericContentOrPresentableSocket <|-- GenericPresentableSocket
+    RtContent <|-- RtContentOrPresentableSocket
+    RtContentOrPresentableSocket <|-- PresentableSocket
+    RtMultiplexedContent <|-- RtMultiplexedContentOrPresentableSocket
+    RtMultiplexedContentOrPresentableSocket <|-- MultiplexedPresentableSocket
+  
+```
+
+Notation:
+
+```
+
+classDiagram
+    class Super-class
+    class Sub-class 1
+    class Sub-class 2
+    class Sub-class 3
+    Super-class <|-- Sub-class 1
+    Super-class <|-- Sub-class 2
+    Super-class <|-- Sub-class 3
+  
+```
+
+T0825200-95/d05
+
+UML class diagram showing the object model for MHEG. The diagram is divided into two main sections: MhObjects and RtObjects. The MhObjects section shows a hierarchy starting with MHEGEngine, EntityManager, and Entity. Entity is a base class for MhObject and Channel. MhObject is a base class for MhAction, MhLink, MhModel, MhContainer, and MhDescriptor. MhModel is a base class for MhComponent and MhScript. MhComponent is a base class for MhGenericContent and MhComposite. MhGenericContent is a base class for MhContent and MhMultiplexedContent. A notation box shows a Super-class with three Sub-classes (Sub-class 1, Sub-class 2, Sub-class 3). The RtObjects section shows a similar hierarchy for real-time objects: RtObjectOrSocket is a base class for RtObject and Socket. RtObject is a base class for RtScript, RtComponent, RtComposite, RtGenericContent, RtContent, and RtMultiplexedContent. RtComponentOrSocket is a base class for RtComponent and Socket. RtCompositeOrStructuralSocket is a base class for RtComposite and StructuralSocket. RtGenericContentOrPresentableSocket is a base class for RtGenericContent and GenericPresentableSocket. RtContentOrPresentableSocket is a base class for RtContent and PresentableSocket. RtMultiplexedContentOrPresentableSocket is a base class for RtMultiplexedContent and MultiplexedPresentableSocket. The diagram is labeled T0825200-95/d05.
+
+NOTE 1 – MhObjects (and their subtypes) match form b) objects as defined in ISO/IEC 13522-1: "Information technology – Coding of multimedia and hypermedia information" [1], 6.2.4, i.e. Objects available to the MHEG engine.
+
+NOTE 2 – RtObjects (and their subtypes) match form c) objects as defined in ISO/IEC 13522-1: "Information technology – Coding of multimedia and hypermedia information" [1], 6.2.4, i.e. Instances of MhObjects available to the presentation process.
+
+Figure 5/T.174 – Object model
+
+## 7 Definition of the MHEG-API
+
+### 7.1 Mandatory primitives
+
+#### 7.1.1 MHEGEngine object
+
+The following subclause defines the operations of the MHEGEngine object.
+
+##### 7.1.1.1 initialiseEngine operation
+
+**Synopsis:**
+
+**Interface:** MHEGEngine  
+**Operation:** initialiseEngine  
+**Result:** void
+
+**Description:**
+
+This operation performs any necessary initialisation of the interface. It shall be invoked before any other interface operations defined in this Recommendation are invoked. It can be invoked multiple times, in which case each invocation shall reinitialise the MHEG Engine.
+
+##### 7.1.1.2 shutdownEngine operation
+
+**Synopsis:**
+
+**Interface:** MHEGEngine  
+**Operation:** shutdownEngine  
+**Result:** void
+
+**Description:**
+
+This operation deletes all service-generated interface objects associated with the current session. The next operation that shall be accepted by an MHEG engine is an initialiseEngine operation.
+
+##### 7.1.1.3 IDL description
+
+```
+interface MHEGEngine    {  
+    void    initialiseEngine ();  
+    void    shutdownEngine ();  
+};
+```
+
+#### 7.1.2 NotificationManager object
+
+The following subclause defines the operations of the NotificationManager object.
+
+##### 7.1.2.1 getReturnability operation
+
+**Synopsis:**
+
+**Interface:** NotificationManager  
+**Operation:** getReturnability  
+**Result:** sequence<unsigned short>
+
+**Description:**
+
+This operation retrieves the returnability behaviour of the MHEG engine.
+
+The operation returns a list of numbers identifying available notifications.
+
+##### 7.1.2.2 getNotification operation
+
+**Synopsis:**
+
+**Interface:** NotificationManager  
+**Operation:** getNotification  
+**Result:** void  
+**In:** unsigned short notification\_number  
+**Out:** sequence<GenericValue> values  
+**Out:** sequence<MhObjectReference> objects  
+**Exception:** InvalidParameter
+
+**Description:**
+
+This operation retrieves a notification from the MHEG engine.
+
+The `notification_number` parameter identifies the notification. This identification may be the result of a `getReturnability` operation.
+
+The `values` parameter specifies the returned values.
+
+The `objects` parameter specifies the returned object references.
+
+The `InvalidParameter` exception is raised when the value of one of the parameters prohibits the normal execution of the action. The `completion_status` member indicates whether the action was completed (with a default value assigned to the inadequate parameter) or not. The `parameter_number` member identifies the rank of the invalid parameter.
+
+**7.1.2.3 IDL description**
+
+```
+
+interface      NotificationManager
+{
+    sequence<unsigned short>
+        getReturnability();
+
+    void
+        getNotification(
+            in unsigned short
+                notification_number,
+            out sequence<GenericValue>
+                values,
+            out sequence<MhObjectReference>
+                objects)
+        raises(InvalidParameter);
+};
+```
+
+**7.1.3 EntityManager object**
+
+The following subclause defines the operations of the `EntityManager` object.
+
+**7.1.3.1 getAvailableMhObjects operation****Synopsis:**
+
+**Interface:**        `EntityManager`  
+**Operation:**      `getAvailableMhObjects`  
+**Result:**          `sequence<MHEGIdentifier>`
+
+**Description:**
+
+This operation retrieves the mh-objects available to the MHEG engine.
+
+An mh-object is either 'not ready' (in period O1), 'processing' (in period O2 or O4) or 'ready' (in period O3). The operation retrieves those mh-objects which are in period O3.
+
+The operation returns the identifiers of the available mh-objects.
+
+**7.1.3.2 getAvailableRtObjects operation****Synopsis:**
+
+**Interface:**        `EntityManager`  
+**Operation:**      `getAvailableRtObjects`  
+**Result:**          `sequence<RtObjectIdentifier>`
+
+**Description:**
+
+This operation retrieves the rt-objects available to the MHEG engine.
+
+An rt-object is either 'not available' (in period R1), 'processing' (in period R2 or R4) or 'available' (in period R3 and its subperiods). The operation retrieves those rt-objects which are in period R3.
+
+The operation returns the identifiers of the available rt-objects.
+
+### 7.1.3.3 getAvailableChannels operation
+
+#### Synopsis:
+
+**Interface:** EntityManager  
+**Operation:** getAvailableChannels  
+**Result:** sequence<ChannelIdentifier>
+
+#### Description:
+
+This operation retrieves the channels available to the MHEG engine.
+
+A channel is either 'not available' (in period C1), 'processing' (in period C2 or C4) or 'available' (in period C3). The operation retrieves those channels which are in period C3.
+
+The operation returns the identifiers of the available channels.
+
+### 7.1.3.4 releaseAlias operation
+
+#### Synopsis:
+
+**Interface:** EntityManager  
+**Operation:** releaseAlias  
+**Result:** void  
+**In:** string alias  
+**Exception:** InvalidParameter
+
+#### Description:
+
+This operation enables to release an alias. It cancels the assignments of this alias to entities.
+
+The `alias` parameter specifies the value of the released alias.
+
+The `InvalidParameter` exception is raised when the value of one of the parameters prohibits the normal execution of the action. The `completion_status` member indicates whether the action was completed (with a default value assigned to the inadequate parameter) or not. The `parameter_number` member identifies the rank of the invalid parameter.
+
+### 7.1.3.5 IDL description
+
+```
+interface      EntityManager      {  
+    sequence<MHEGIdentifier>  
+        getAvailableMhObjects();  
+    sequence<RtObjectIdentifier>  
+        getAvailableRtObjects();  
+    sequence<ChannelIdentifier>  
+        getAvailableChannels();  
+    void  
+        release Alias(  
+            in string  
+                alias)  
+        raises(InvalidParameter);  
+};
+```
+
+## 7.1.4 Entity object
+
+The following subclause defines the operations of the `Entity` object.
+
+### 7.1.4.1 setAlias operation
+
+#### Synopsis:
+
+**Interface:** Entity  
+**Operation:** setAlias  
+**Result:** void  
+**In:** string alias  
+**Exception:** InvalidTarget
+
+**Description:**
+
+This operation enables the assignment of an alias to any entity.
+
+The `setAlias` operation triggers the execution of the 'set alias' elementary action with the bound entity as its single target.
+
+The effect of the action on its target, the semantics of its parameters and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 34.2.1.
+
+The `alias` parameter specifies the value of the 'alias' parameter of the 'set alias' action.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+**7.1.4.2 getAlias operation****Synopsis:**
+
+**Interface:** Entity  
+**Operation:** getAlias  
+**Result:** string  
+**Exception:** InvalidTarget
+
+**Description:**
+
+This operation retrieves the alias assigned to an entity.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+**7.1.4.3 IDL description**
+
+```
+interface Entity {
+    void
+        setAlias(
+            in string
+                alias)
+    raises(InvalidTarget);
+
+    string
+        getAlias()
+    raises(InvalidTarget);
+};
+```
+
+**7.1.5 MhObject object**
+
+The following subclause defines the operations of the `MhObject` object. The object inherits from the `Entity` object.
+
+**7.1.5.1 bind operation****Synopsis:**
+
+**Interface:** MhObject  
+**Operation:** bind  
+**Result:** MHEGIdentifier  
+**In:** MhObjectReference mh\_object\_reference  
+**Exception:** AlreadyBound  
+**Exception:** InvalidTarget
+
+**Description:**
+
+This operation binds the `MhObject` instance (an interface object instance) with an MHEG object (an MHEG entity).
+
+The `mh_object_reference` parameter specifies the reference of the MHEG object.
+
+The operation returns the identifier of the bound MHEG object.
+
+The `AlreadyBound` exception is raised when the interface object instance is already bound with an MHEG entity.
+
+The `InvalidTarget` exception is raised when the targeted MHEG entity is not available. The `period` member returns the current period of the target.
+
+### 7.1.5.2 unbind operation
+
+#### Synopsis:
+
+**Interface:** MhObject  
+**Operation:** unbind  
+**Result:** void  
+**Exception:** NotBound
+
+#### Description:
+
+This operation cancels the binding between the MhObject instance (an interface object instance) and an MHEG object (an MHEG entity).
+
+The NotBound exception is raised when the interface object instance is not bound with an MHEG entity.
+
+### 7.1.5.3 prepare operation
+
+#### Synopsis:
+
+**Interface:** MhObject  
+**Operation:** prepare  
+**Result:** MHEGIdentifier  
+**In:** MhObjectReference mh\_object\_reference  
+**Exception:** AlreadyBound  
+**Exception:** InvalidTarget
+
+#### Description:
+
+This operation enables the creation of an MHEG object from a model object by the MHEG engine.
+
+The prepare operation triggers the execution of the 'prepare' elementary action targeted at a single MHEG object.
+
+The effect of the action on its target and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 36.2.1.
+
+The mh\_object\_reference parameter specifies a reference to an MHEG object.
+
+This operation implicitly binds the MhObject instance (an interface object instance) with the new prepared MHEG object (an MHEG entity).
+
+The operation returns the identifier of the new prepared MHEG object bound with the MhObject instance.
+
+The AlreadyBound exception is raised when the interface object instance is already bound with an MHEG entity.
+
+The InvalidTarget exception is raised when the targeted MHEG entity is not available. The period member returns the current period of the target.
+
+### 7.1.5.4 destroy operation
+
+#### Synopsis:
+
+**Interface:** MhObject  
+**Operation:** destroy  
+**Result:** void  
+**Exception:** NotBound  
+**Exception:** InvalidTarget
+
+#### Description:
+
+This operation enables the removing of an MHEG object by the MHEG engine.
+
+The destroy operation triggers the execution of the 'destroy' elementary action targeted at a single MHEG object.
+
+The effect of the action on its target and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 36.2.2.
+
+This operation implicitly cancels the binding between the MhObject instance (an interface object instance) and the new destroyed MHEG object (an MHEG entity).
+
+The NotBound exception is raised when the interface object instance is not bound with an MHEG entity.
+
+The `InvalidTarget` exception is raised when the targeted MHEG entity is not available. The `period` member returns the current period of the target.
+
+#### 7.1.5.5 `getPreparationStatus` operation
+
+##### Synopsis:
+
+**Interface:** `MhObject`  
+**Operation:** `getPreparationStatus`  
+**Result:** `PreparationStatusValue`  
+**Exception:** `NotBound`  
+**Exception:** `InvalidTarget`
+
+##### Description:
+
+This operation retrieves the availability of an MHEG object to the MHEG engine.
+
+The `getPreparationStatus` operation triggers the execution of the 'get preparation status' elementary action with the bound MHEG object as its single target.
+
+The effect of the action on its target, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 36.3.1.
+
+The operation returns the availability of the MHEG object bound with the `MhObject` instance. The returned value is either `NOT_READY`, `PROCESSING` or `READY`.
+
+When the returned value is `NOT_READY`, the operation implicitly cancels the binding between the `MhObject` instance (an interface object instance) and the MHEG object (an MHEG entity).
+
+The `NotBound` exception is raised when the interface object instance is not bound with an MHEG entity.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+#### 7.1.5.6 `getIdentifier` operation
+
+##### Synopsis:
+
+**Interface:** `MhObject`  
+**Operation:** `getIdentifier`  
+**Result:** `MHEGIdentifier`  
+**Exception:** `NotBound`
+
+##### Description:
+
+This operation retrieves the identifier of the MHEG object (an MHEG entity) bound with the `MhObject` instance (an interface object instance).
+
+The `NotBound` exception is raised when the interface object instance is not bound with an MHEG entity.
+
+#### 7.1.5.7 `kill` operation
+
+##### Synopsis:
+
+**Interface:** `MhObject`  
+**Operation:** `kill`  
+**Result:** `void`
+
+##### Description:
+
+This operation deletes the `MhObject` instance (an interface object instance).
+
+#### 7.1.5.8 IDL description
+
+```
+interface      MhObject: Entity                                {
+    MHEGIdentifier
+        bind(
+            in MhObjectReference
+                mh_object_reference)
+    raises(AlreadyBound, InvalidTarget);
+}
+```
+
+```
+
+void
+    unbind()
+
+raises (NotBound);
+
+MHEGIdentifier
+    prepare(
+        in MhObjectReference
+            mh_object_reference)
+raises (AlreadyBound, InvalidTarget);
+
+void
+    destroy()
+raises (NotBound, InvalidTarget);
+
+PreparationStatusValue
+    getPreparationStatus()
+raises (NotBound, InvalidTarget);
+
+MHEGIdentifier
+    getIdentifier()
+raises (NotBound);
+
+void
+    kill();
+
+};
+
+```
+
+### 7.1.6 MhAction object
+
+The following subclause defines the operations of the MhAction object. The object inherits from the MhObject object.
+
+#### 7.1.6.1 delay operation
+
+##### Synopsis:
+
+|                   |                  |                      |
+|-------------------|------------------|----------------------|
+| <b>Interface:</b> | MhAction         |                      |
+| <b>Operation:</b> | delay            |                      |
+| <b>Result:</b>    | void             |                      |
+| <b>In:</b>        | unsigned short   | nested_action_number |
+| <b>In:</b>        | unsigned long    | delay                |
+| <b>Exception:</b> | InvalidTarget    |                      |
+| <b>Exception:</b> | InvalidParameter |                      |
+
+##### Description:
+
+This operation enables to delay the process of nested actions within the mh-action.
+
+The `nested_action_number` parameter specifies the nested action after which the delay is to be processed.
+
+The `delay` parameter specifies the duration of the delay expressed in Generic Temporal Unit (GTU).
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+The `InvalidParameter` exception is raised when the value of one of the parameters prohibits the normal execution of the action. The `completion_status` member indicates whether the action was completed (with a default value assigned to the inadequate parameter) or not. The `parameter_number` member identifies the rank of the invalid parameter.
+
+#### 7.6.1.2 IDL description
+
+```
+
+interface      MhAction: MhObject
+{
+    void
+        delay(
+            in unsigned short
+                nested_action_number,
+            in unsigned long
+                delay)
+        raises (InvalidTarget, InvalidParameter);
+};
+
+```
+
+### 7.1.7 MhLink object
+
+The following subclause defines the operations of the MhLink object. The object inherits from the MhObject object.
+
+#### 7.1.7.1 abort operation
+
+##### Synopsis:
+
+**Interface:** MhLink  
+**Operation:** abort  
+**Result:** void  
+**Exception:** InvalidTarget
+
+##### Description:
+
+This operation aborts the processing of all the actions that have been activated by a link object. Each time the link condition is satisfied, the actions defining the link effect are activated and processed.
+
+The abort operation triggers the execution of the 'abort' elementary action with the bound link object as its single target.
+
+The effect of the action on its target, the semantics of its parameters and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 38.2.1.
+
+The InvalidTarget exception is raised when the object instance does not represent a valid target for the normal completion of the action. The period member returns the current period of the target.
+
+#### 7.1.7.2 IDL description
+
+```
+interface MhLink: MhObject
+{
+    void
+        abort()
+    raises(InvalidTarget);
+};
+```
+
+### 7.1.8 MhModel object
+
+For the MhModel object no specific operations are defined. The object inherits from the MhObject object.
+
+#### 7.1.8.1 IDL description
+
+```
+interface MhModel: MhObject {};
+```
+
+### 7.1.9 MhComponent object
+
+For the MhComponent object no specific operations are defined. The object inherits from the MhModel object.
+
+#### 7.1.9.1 IDL description
+
+```
+interface MhComponent: MhModel {};
+```
+
+### 7.1.10 MhGenericContent object
+
+The following subclause defines the operations of the MhGenericContent object. The object inherits from the MhComponent object.
+
+#### 7.1.10.1 copy operation
+
+##### Synopsis:
+
+**Interface:** MhContent  
+**Operation:** copy  
+**Result:** void  
+**In:** sequence<MhObjectReference> copies  
+**Exception:** InvalidTarget  
+**Exception:** InvalidParameter
+
+##### Description:
+
+This operation specifies the copy of a content object "source" in a set of content objects "copies" or the copy of a multiplexed content object "source" in a set of multiplexed content objects "copies".
+
+The `copy` operation triggers the execution of the 'copy' elementary action with the bound content object or multiplexed content object as its single target.
+
+The effect of the action on its target, the semantics of its parameters and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 40.2.1.
+
+The `copies` parameter specifies the value of the 'copies' parameter of the 'copy' action.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+The `InvalidParameter` exception is raised when the value of one of the parameters prohibits the normal execution of the action. The `completion_status` member indicates whether the action was completed (with a default value assigned to the inadequate parameter) or not. The `parameter_number` member identifies the rank of the invalid parameter.
+
+### 7.1.10.2 IDL description
+
+```
+interface MhGenericContent: MhComponent {
+    void
+        copy(
+            in sequence<MhObjectReference>
+                copies)
+        raises(InvalidTarget, InvalidParameter);
+};
+```
+
+### 7.1.11 MhContent object
+
+The following subclause defines the operations of the `MhContent` object. The object inherits from the `MhGenericContent` object.
+
+#### 7.1.11.1 setData operation
+
+##### Synopsis:
+
+|                   |                                          |                                     |
+|-------------------|------------------------------------------|-------------------------------------|
+| <b>Interface:</b> | <code>MhContent</code>                   |                                     |
+| <b>Operation:</b> | <code>setData</code>                     |                                     |
+| <b>Result:</b>    | <code>void</code>                        |                                     |
+| <b>In:</b>        | <code>boolean</code>                     | <code>substitution_indicator</code> |
+| <b>In:</b>        | <code>sequence&lt;DataElement&gt;</code> | <code>data_elements</code>          |
+| <b>Exception:</b> | <code>InvalidTarget</code>               |                                     |
+| <b>Exception:</b> | <code>InvalidParameter</code>            |                                     |
+
+##### Description:
+
+This operation allows to store or to modify the generic value in the data of a content object.
+
+The `setData` operation triggers the execution of the 'set data' elementary action with the bound content object as its single target.
+
+The effect of the action on its target, the semantics of its parameters and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 39.2.1.
+
+The `substitution_indicator` parameter specifies the value of the 'substitution indicator' parameter of the 'set data' action.
+
+The `data_elements` parameter specifies the value of the 'data elements' parameter of the 'set data' action.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+The `InvalidParameter` exception is raised when the value of one of the parameters prohibits the normal execution of the action. The `completion_status` member indicates whether the action was completed (with a default value assigned to the inadequate parameter) or not. The `parameter_number` member identifies the rank of the invalid parameter.
+
+### 7.1.11.2 getData operation
+
+#### Synopsis:
+
+|                   |                                   |
+|-------------------|-----------------------------------|
+| <b>Interface:</b> | MhContent                         |
+| <b>Operation:</b> | getData                           |
+| <b>Result:</b>    | GenericValue                      |
+| <b>In:</b>        | sequence<long> element_list_index |
+| <b>Exception:</b> | InvalidTarget                     |
+| <b>Exception:</b> | InvalidParameter                  |
+
+#### Description:
+
+This operation retrieves a generic value or an element of a generic list stored in the data of a content object.
+
+The `getData` operation triggers the execution of the 'get data' elementary action with the bound content object as its single target.
+
+The effect of the action on its target, the semantics of its parameters, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 39.3.1.
+
+The `element_list_index` parameter specifies the value of the 'element list index parameter' parameter of the 'get data' action.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+The `InvalidParameter` exception is raised when the value of one of the parameters prohibits the normal execution of the action. The `completion_status` member indicates whether the action was completed (with a default value assigned to the inadequate parameter) or not. The `parameter_number` member identifies the rank of the invalid parameter.
+
+### 7.1.11.3 IDL description
+
+```
+interface MhContent: MhGenericContent
+{
+    void
+        setData(
+            in boolean
+                substitution_indicator,
+            in sequence<DataElement>
+                data_elements)
+        raises(InvalidTarget, InvalidParameter);
+    GenericValue
+        getData(
+            in sequence<long>
+                element_list_index)
+        raises(InvalidTarget, InvalidParameter);
+};
+```
+
+### 7.1.12 MhMultiplexedContent object
+
+The following subclause defines the operations of the `MhMultiplexedContent` object. The object inherits from the `MhGenericContent` object.
+
+#### 7.1.12.1 setMultiplex operation
+
+##### Synopsis:
+
+|                   |                                        |
+|-------------------|----------------------------------------|
+| <b>Interface:</b> | MhMultiplexedContent                   |
+| <b>Operation:</b> | setMultiplex                           |
+| <b>Result:</b>    | void                                   |
+| <b>In:</b>        | sequence<StreamIdentifier> stream_list |
+| <b>Exception:</b> | InvalidTarget                          |
+| <b>Exception:</b> | InvalidParameter                       |
+
+#### Description:
+
+This operation specifies the multiplexing of a list of content objects, the result is set in one multiplexed content object containing the multiplexed data.
+
+The `setMultiplex` operation triggers the execution of the 'set multiplex' elementary action with the bound multiplexed content object as its single target.
+
+The effect of the action on its target, the semantics of its parameters and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 41.2.1.
+
+The `stream_list` parameter specifies the value of the 'stream list' parameter of the 'set multiplex' action.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+The `InvalidParameter` exception is raised when the value of one of the parameters prohibits the normal execution of the action. The `completion_status` member indicates whether the action was completed (with a default value assigned to the inadequate parameter) or not. The `parameter_number` member identifies the rank of the invalid parameter.
+
+#### 7.1.12.2 setDemultiplex operation
+
+##### Synopsis:
+
+|                   |                                                             |
+|-------------------|-------------------------------------------------------------|
+| <b>Interface:</b> | MhMultiplexedContent                                        |
+| <b>Operation:</b> | setDemultiplex                                              |
+| <b>Result:</b>    | void                                                        |
+| <b>In:</b>        | sequence<StreamIdentifier>                      stream_list |
+| <b>Exception:</b> | InvalidTarget                                               |
+| <b>Exception:</b> | InvalidParameter                                            |
+
+##### Description:
+
+This operation specifies the demultiplexing of a multiple stream data of a multiplexed content object, e.g. a Moving Picture Experts Group (MPEG) stream; the result is set in a list of content objects which are generated if they do not exist yet. Each content object contains one demultiplexed stream.
+
+The `setDemultiplex` operation triggers the execution of the 'set demultiplex' elementary action with the bound multiplexed content object as its single target.
+
+The effect of the action on its target, the semantics of its parameters and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 41.2.2.
+
+The `stream_list` parameter specifies the value of the 'stream list' parameter of the 'set demultiplex' action.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+The `InvalidParameter` exception is raised when the value of one of the parameters prohibits the normal execution of the action. The `completion_status` member indicates whether the action was completed (with a default value assigned to the inadequate parameter) or not. The `parameter_number` member identifies the rank of the invalid parameter.
+
+#### 7.1.12.3 IDL description
+
+```
+interface MhMultiplexedContent: MhGenericContent                      {  
+    void  
+        setMultiplex(  
+            in sequence<StreamIdentifier>  
+                stream_list)  
+        raises(InvalidTarget, InvalidParameter);  
+    void  
+        setDemultiplex(  
+            in sequence<StreamIdentifier>  
+                stream_list)  
+        raises(InvalidTarget, InvalidParameter);  
+};
+```
+
+#### 7.1.13 MhComposite object
+
+For the `MhComposite` object no specific operations are defined. The object inherits from the `MhComponent` object.
+
+##### 7.1.13.1 IDL description
+
+```
+interface MhComposite: MhComponent {};
+```
+
+#### 7.1.14 MhScript object
+
+For the MhScript object no specific operations are defined. The object inherits from the MhModel object.
+
+##### 7.1.14.1 IDL description
+
+```
+interface MhScript: MhModel {};
+```
+
+#### 7.1.15 MhContainer object
+
+For the MhContainer object no specific operations are defined. The object inherits from the MhObject object.
+
+##### 7.1.15.1 IDL description
+
+```
+interface MhContainer: MhObject {};
+```
+
+#### 7.1.16 MhDescriptor object
+
+For the MhDescriptor object no specific operations are defined. The object inherits from the MhObject object.
+
+##### 7.1.16.1 IDL description
+
+```
+interface MhDescriptor: MhObject {};
+```
+
+#### 7.1.17 RtObjectOrSocket object
+
+The following subclause defines the operations of the RtObjectOrSocket object.
+
+##### 7.1.17.1 setGlobalBehaviour operation
+
+###### Synopsis:
+
+|                   |                    |                  |
+|-------------------|--------------------|------------------|
+| <b>Interface:</b> | RtObject           |                  |
+| <b>Operation:</b> | setGlobalBehaviour |                  |
+| <b>Result:</b>    | void               |                  |
+| <b>In:</b>        | GlobalBehaviour    | global_behaviour |
+| <b>Exception:</b> | InvalidTarget      |                  |
+| <b>Exception:</b> | InvalidParameter   |                  |
+
+###### Description:
+
+This operation enables the modification of the global behaviour of an rt-object or a socket.
+
+The setGlobalBehaviour operation triggers the execution of the 'set global behaviour' elementary action with the bound rt-object or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 44.2.1.
+
+The global\_behaviour parameter specifies the value of the 'global behaviour' parameter of the 'set global behaviour' action.
+
+The InvalidTarget exception is raised when the object instance does not represent a valid target for the normal completion of the action. The period member returns the current period of the target.
+
+The InvalidParameter exception is raised when the value of one of the parameters prohibits the normal execution of the action. The completion\_status member indicates whether the action was completed (with a default value assigned to the inadequate parameter) or not. The parameter\_number member identifies the rank of the invalid parameter.
+
+##### 7.1.17.2 getGlobalBehaviour operation
+
+###### Synopsis:
+
+|                   |                    |
+|-------------------|--------------------|
+| <b>Interface:</b> | RtObject           |
+| <b>Operation:</b> | getGlobalBehaviour |
+| <b>Result:</b>    | GenericValue       |
+| <b>Exception:</b> | InvalidTarget      |
+
+###### Description:
+
+This operation retrieves all the attributes value composing the global behaviour of each rt-object or socket to the MHEG engine.
+
+The `getGlobalBehaviour` operation triggers the execution of the 'get global behaviour' elementary action with the bound rt-object or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 44.3.1.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+#### 7.1.17.3 run operation
+
+##### Synopsis:
+
+**Interface:** `RtObject`  
+**Operation:** `run`  
+**Result:** `void`  
+**Exception:** `InvalidTarget`
+
+##### Description:
+
+This operation enables the activation of the rt-object or the socket by the running process.
+
+The `run` operation triggers the execution of the 'run' elementary action with the bound rt-object or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 45.2.1.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+#### 7.1.17.4 stop operation
+
+##### Synopsis:
+
+**Interface:** `RtObject`  
+**Operation:** `stop`  
+**Result:** `void`  
+**Exception:** `InvalidTarget`
+
+##### Description:
+
+This operation removes the rt-object from the running process.
+
+The `stop` operation triggers the execution of the 'stop' elementary action with the bound rt-object as its single target.
+
+The effect of the action on its target, the semantics of its parameters and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 45.2.2.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+#### 7.1.17.5 IDL description
+
+```
+interface RtObjectOrSocket {
+    void
+        setGlobalBehaviour(
+            in GlobalBehaviour
+                global_behaviour)
+        raises(InvalidTarget, InvalidParameter);
+    GenericValue
+        getGlobalBehaviour()
+        raises(InvalidTarget);
+    void
+        run()
+        raises(InvalidTarget);
+    void
+        stop()
+        raises(InvalidTarget);
+};
+```
+
+### 7.1.18 RtObject object
+
+The following subclause defines the operations of the RtObject object. The object inherits from the RtObjectOrSocket and from the Entity object.
+
+#### 7.1.18.1 bind operation
+
+##### Synopsis:
+
+|                   |                    |                     |
+|-------------------|--------------------|---------------------|
+| <b>Interface:</b> | RtObject           |                     |
+| <b>Operation:</b> | bind               |                     |
+| <b>Result:</b>    | RtObjectIdentifier |                     |
+| <b>In:</b>        | RtObjectReference  | rt_object_reference |
+| <b>Exception:</b> | AlreadyBound       |                     |
+| <b>Exception:</b> | InvalidTarget      |                     |
+
+##### Description:
+
+This operation binds the RtObject instance (an interface object instance) with an rt-object (an MHEG entity).
+
+The `rt_object_reference` parameter specifies the reference of the rt-object.
+
+The operation returns the identifier of the bound rt-object.
+
+The `AlreadyBound` exception is raised when the interface object instance is already bound with an MHEG entity.
+
+The `InvalidTarget` exception is raised when the targeted MHEG entity is not available. The `period` member returns the current period of the target.
+
+#### 7.1.18.2 unbind operation
+
+##### Synopsis:
+
+|                   |          |
+|-------------------|----------|
+| <b>Interface:</b> | RtObject |
+| <b>Operation:</b> | unbind   |
+| <b>Result:</b>    | void     |
+| <b>Exception:</b> | NotBound |
+
+##### Description:
+
+This operation cancels the binding between the RtObject instance (an interface object instance) and an rt-object (an MHEG entity).
+
+The `NotBound` exception is raised when the interface object instance is not bound with an MHEG entity.
+
+#### 7.1.18.3 new operation
+
+##### Synopsis:
+
+|                   |                    |                     |
+|-------------------|--------------------|---------------------|
+| <b>Interface:</b> | RtObject           |                     |
+| <b>Operation:</b> | new                |                     |
+| <b>Result:</b>    | RtObjectIdentifier |                     |
+| <b>In:</b>        | RtObjectReference  | rt_object_reference |
+| <b>Exception:</b> | AlreadyBound       |                     |
+| <b>Exception:</b> | InvalidTarget      |                     |
+
+##### Description:
+
+This operation enables the creation of an rt-object from a model object by the MHEG engine.
+
+The `new` operation triggers the execution of the 'new' elementary action targeted at a single rt-object.
+
+The effect of the action on its target and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 43.2.1.
+
+The `rt_object_reference` parameter specifies a reference to an rt-object.
+
+This operation implicitly binds the RtObject instance (an interface object instance) with the new created rt-object (an MHEG entity).
+
+The operation returns the identifier of the new created rt-object bound with the RtObject instance.
+
+The `AlreadyBound` exception is raised when the interface object instance is already bound with an MHEG entity.
+
+The `InvalidTarget` exception is raised when the targeted MHEG entity is not available. The `period` member returns the current period of the target.
+
+#### 7.1.18.4 `delete` operation
+
+##### Synopsis:
+
+**Interface:** `RtObject`  
+**Operation:** `delete`  
+**Result:** `void`  
+**Exception:** `NotBound`  
+**Exception:** `InvalidTarget`
+
+##### Description:
+
+This operation enables the removing of an rt-object by the MHEG engine.
+
+The `delete` operation triggers the execution of the 'delete' elementary action targeted at a single rt-object.
+
+The effect of the action on its target and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 43.2.2.
+
+This operation implicitly cancels the binding between the `RtObject` instance (an interface object instance) and the new deleted rt-object (an MHEG entity).
+
+The `NotBound` exception is raised when the interface object instance is not bound with an MHEG entity.
+
+The `InvalidTarget` exception is raised when the targeted MHEG entity is not available. The `period` member returns the current period of the target.
+
+#### 7.1.18.5 `getAvailabilityStatus` operation
+
+##### Synopsis:
+
+**Interface:** `RtObject`  
+**Operation:** `getAvailabilityStatus`  
+**Result:** `RtAvailabilityStatusValue`  
+**Exception:** `NotBound`  
+**Exception:** `InvalidTarget`
+
+##### Description:
+
+This operation retrieves the availability of an rt-object to the MHEG engine.
+
+The `getAvailabilityStatus` operation triggers the execution of the 'get rt-availability status' elementary action with the bound rt-object as its single target.
+
+The effect of the action on its target, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 43.3.1.
+
+The operation returns the availability of the rt-object bound with the `RtObject` instance. The returned value is either `NOT_AVAILABLE`, `PROCESSING` or `AVAILABLE`.
+
+When the returned value is `NOT_AVAILABLE`, the operation implicitly cancels the binding between the `RtObject` instance (an interface object instance) and the rt-object (an MHEG entity).
+
+The `NotBound` exception is raised when the interface object instance is not bound with an MHEG entity.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+#### 7.1.18.6 `getIdentifier` operation
+
+##### Synopsis:
+
+**Interface:** `RtObject`  
+**Operation:** `getIdentifier`  
+**Result:** `RtObjectIdentifier`  
+**Exception:** `NotBound`
+
+**Description:**
+
+This operation retrieves the identifier of the rt-object (an MHEG entity) bound with the RtObject instance (an interface object instance).
+
+The `NotBound` exception is raised when the interface object instance is not bound with an MHEG entity.
+
+**7.1.18.7 kill operation****Synopsis:**
+
+**Interface:** RtObject  
+**Operation:** kill  
+**Result:** void
+
+**Description:**
+
+This operation deletes the RtObject instance (an interface object instance).
+
+**7.1.18.8 getRunningStatus operation****Synopsis:**
+
+**Interface:** RtObject  
+**Operation:** getRunningStatus  
+**Result:** RunningStatusValue  
+**Exception:** InvalidTarget
+
+**Description:**
+
+This operation gets the activation of each rt-object and each socket by the MHEG engine.
+
+The `getRunningStatus` operation triggers the execution of the 'get running status' elementary action with the bound rt-object or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 45.3.1.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+**7.1.18.9 IDL description**
+
+```
+interface RtObject: Entity {
+    RtObjectIdentifier
+        bind(
+            in RtObjectReference
+                rt_object_reference)
+        raises(AlreadyBound, InvalidTarget);
+    void
+        unbind()
+        raises(NotBound);
+    RtObjectIdentifier
+        new(
+            in RtObjectReference
+                rt_object_reference)
+        raises(AlreadyBound, InvalidTarget);
+    void
+        delete()
+        raises(NotBound, InvalidTarget);
+    RtAvailabilityStatusValue
+        getAvailabilityStatus()
+        raises(NotBound, InvalidTarget);
+    RtObjectIdentifier
+        getIdentifier()
+        raises(NotBound);
+    void
+        kill();
+```
+
+```
+
+        RunningStatusValue
+            getRunningStatus()
+            raises(InvalidTarget);
+};
+
+```
+
+#### 7.1.19 Socket object
+
+The following subclause defines the operations of the Socket object. The object inherits from the RtObjectOrSocket and from the Entity object.
+
+##### 7.1.19.1 bind operation
+
+###### Synopsis:
+
+```
+
+Interface:      Socket
+Operation:     bind
+Result:        SocketIdentification
+In:            SocketReference          socket_reference
+Exception:     AlreadyBound
+Exception:     InvalidTarget
+
+```
+
+###### Description:
+
+This operation binds the Socket instance (an interface object instance) with a socket (an MHEG entity).
+
+The `socket_reference` parameter specifies the reference of the socket.
+
+The operation returns the identifier of the bound socket.
+
+The `AlreadyBound` exception is raised when the interface object instance is already bound with an MHEG entity.
+
+The `InvalidTarget` exception is raised when the targeted MHEG entity is not available. The `period` member returns the current period of the target.
+
+##### 7.1.19.2 unbind operation
+
+###### Synopsis:
+
+```
+
+Interface:      Socket
+Operation:     unbind
+Result:        void
+Exception:     NotBound
+
+```
+
+###### Description:
+
+This operation cancels the binding between the Socket instance (an interface object instance) and a socket (an MHEG entity).
+
+The `NotBound` exception is raised when the interface object instance is not bound with an MHEG entity.
+
+##### 7.1.19.3 getIdentifier operation
+
+###### Synopsis:
+
+```
+
+Interface:      Socket
+Operation:     getIdentifier
+Result:        SocketIdentification
+
+```
+
+###### Description:
+
+This operation retrieves the identifier of the socket (an MHEG entity) bound with the Socket instance (an interface object instance).
+
+The `NotBound` exception is raised when the interface object instance is not bound with an MHEG entity.
+
+##### 7.1.19.4 kill operation
+
+###### Synopsis:
+
+```
+
+Interface:      Socket
+Operation:     kill
+Result:        void
+
+```
+
+**Description:**
+
+This operation deletes the Socket instance (an interface object instance).
+
+**7.1.19.5 plug operation****Synopsis:**
+
+**Interface:** Socket  
+**Operation:** plug  
+**Result:** void  
+**In:** PlugIn plug\_in  
+**Exception:** InvalidTarget
+
+**Description:**
+
+This operation enables a dynamism in the presentation and structure. This operation specifies the information to be plugged into a socket. This is used to obtain a different presentation or structure from the same composite object model.
+
+The `plug` operation triggers the execution of the 'plug' elementary action with the bound socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 48.2.1.
+
+The `plug_in` parameter specifies the value of the 'plug in' parameter of the 'plug' action.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+**7.1.19.6 setVisibleDurationPosition operation****Synopsis:**
+
+**Interface:** Socket  
+**Operation:** setVisibleDurationPosition  
+**Result:** void  
+**In:** VisibleDurationPosition visible\_duration\_position  
+**Exception:** InvalidTarget  
+**Exception:** InvalidParameter
+
+**Description:**
+
+This operation specifies within the perceptible duration of the parent the position where to attach the visible duration of a socket.
+
+The `setVisibleDurationPosition` operation triggers the execution of the 'set visible duration position' elementary action with the bound socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 52.2.4.
+
+The `visible_duration_position` parameter specifies the value of the 'parent relative generic space temporal position' parameter of the 'set visible duration position' action.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+The `InvalidParameter` exception is raised when the value of one of the parameters prohibits the normal execution of the action. The `completion_status` member indicates whether the action was completed (with a default value assigned to the inadequate parameter) or not. The `parameter_number` member identifies the rank of the invalid parameter.
+
+**7.1.19.7 getVisibleDurationPosition operation****Synopsis:**
+
+**Interface:** Socket  
+**Operation:** getVisibleDurationPosition  
+**Result:** unsigned long  
+**Exception:** InvalidTarget
+
+**Description:**
+
+This operation retrieves the visible duration position value of the socket within its parent relative generic space. This value is retrieved in relative generic temporal unit.
+
+The `getVisibleDurationPosition` operation triggers the execution of the 'get VD position' elementary action with the bound socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 52.3.7.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+**7.1.19.8 IDL description**
+
+```
+interface Socket: Entity, RtObjectOrSocket
+{
+    SocketIdentification
+        bind(
+            in SocketReference
+                socket_reference)
+        raises(AlreadyBound, InvalidTarget);
+
+    void unbind()
+        raises(NotBound);
+
+    SocketIdentification
+        getIdentifier();
+
+    void
+        kill();
+
+    void
+        plug(
+            in PlugIn
+                plug_in)
+        raises(InvalidTarget);
+
+    void
+        setVisibleDurationPosition(
+            in VisibleDurationPosition
+                visible_duration_position)
+        raises(InvalidTarget, InvalidParameter);
+
+    unsigned long
+        getVisibleDurationPosition()
+        raises(InvalidTarget);
+};
+```
+
+**7.1.20 RtScript object**
+
+The following subclause defines the operations of the `RtScript` object. The object inherits from the `RtObject` object.
+
+**7.1.20.1 setParameters operation****Synopsis:**
+
+|                   |                                        |                         |
+|-------------------|----------------------------------------|-------------------------|
+| <b>Interface:</b> | <code>RtScript</code>                  |                         |
+| <b>Operation:</b> | <code>setParameters</code>             |                         |
+| <b>Result:</b>    | <code>void</code>                      |                         |
+| <b>In:</b>        | <code>sequence&lt;Parameter&gt;</code> | <code>parameters</code> |
+| <b>Exception:</b> | <code>InvalidTarget</code>             |                         |
+
+**Description:**
+
+This operation enables to pass parameters between rt-scripts and other MHEG entities.
+
+The `setParameters` operation triggers the execution of the 'set parameters' elementary action with the bound rt-script as its single target.
+
+The effect of the action on its target, the semantics of its parameters and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 46.2.1.
+
+The `parameters` parameter specifies the value of the 'parameters' parameter of the 'set parameters' action.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+#### 7.1.20.2 `getTerminationStatus` operation
+
+##### Synopsis:
+
+**Interface:** `RtScript`  
+**Operation:** `getTerminationStatus`  
+**Result:** `TerminationStatusValue`  
+**Exception:** `InvalidTarget`
+
+##### Description:
+
+This operation gets the process termination of each rt-script and by the script process.
+
+The `getTerminationStatus` operation triggers the execution of the 'get termination status' elementary action with the bound rt-script as its single target.
+
+The effect of the action on its target, the semantics of its parameters, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 47.3.1.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+#### 7.1.20.3 IDL description
+
+```
+interface RtScript: RtObject {
+    void
+        setParameters (
+            in sequence<Parameter>
+                parameters)
+    raises(InvalidTarget);
+    TerminationStatusValue
+        getTerminationStatus()
+    raises(InvalidTarget);
+};
+```
+
+#### 7.1.21 `RtComponentOrSocket` object
+
+The following subclause defines the operations of the `RtComponentOrSocket` object.
+
+##### 7.1.21.1 `setRGS` operation
+
+##### Synopsis:
+
+**Interface:** `RtComponentOrSocket`  
+**Operation:** `setRGS`  
+**Result:** `void`  
+**In:** `ChannelIdentifier` `channel_identifier`  
+**Exception:** `InvalidTarget`
+
+##### Description:
+
+This operation assigns an rt-component or a socket to a Relative Generic Space (RGS).
+
+The `setRGS` operation triggers the execution of the 'set RGS' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 50.2.1.
+
+The `channel_identifier` parameter specifies the value of the 'channel identifier' parameter of the 'set RGS' action.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+
+
+The effect of the action on its target, the semantics of its parameters and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 51.2.2.
+
+The `presentation_priority` parameter specifies the value of the 'presentation priority' parameter of the 'set Presentation priority' action.
+
+The `transition_duration` parameter specifies the value of the 'transition duration' parameter of the 'set Presentation priority' action.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+The `InvalidParameter` exception is raised when the value of one of the parameters prohibits the normal execution of the action. The `completion_status` member indicates whether the action was completed (with a default value assigned to the inadequate parameter) or not. The `parameter_number` member identifies the rank of the invalid parameter.
+
+#### 7.1.21.5 `getOpacity` operation
+
+##### Synopsis:
+
+**Interface:** `RtComponentOrSocket`  
+**Operation:** `getOpacity`  
+**Result:** `unsigned short`  
+**Exception:** `InvalidTarget`
+
+##### Description:
+
+This operation retrieves the opacity value of an rt-component or a socket.
+
+The `getOpacity` operation triggers the execution of the 'get opacity' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 51.3.1.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+#### 7.1.21.6 `getEffectiveOpacity` operation
+
+##### Synopsis:
+
+**Interface:** `RtComponentOrSocket`  
+**Operation:** `getEffectiveOpacity`  
+**Result:** `unsigned short`  
+**Exception:** `InvalidTarget`
+
+##### Description:
+
+This operation retrieves the effective opacity value of an rt-component or a socket.
+
+The `getEffectiveOpacity` operation triggers the execution of the 'get effective opacity' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 51.3.2.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+#### 7.1.21.7 `getPresentationPriority` operation
+
+##### Synopsis:
+
+**Interface:** `RtComponentOrSocket`  
+**Operation:** `getPresentationPriority`  
+**Result:** `unsigned short`  
+**Exception:** `InvalidTarget`
+
+##### Description:
+
+This operation retrieves the presentation priority of an rt-component or a socket.
+
+The `getPresentationPriority` operation triggers the execution of the 'get presentation priority' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 51.3.3.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+#### 7.1.21.8 `setVisibleDuration` operation
+
+##### Synopsis:
+
+|                   |                                  |                                         |
+|-------------------|----------------------------------|-----------------------------------------|
+| <b>Interface:</b> | <code>RtComponentOrSocket</code> |                                         |
+| <b>Operation:</b> | <code>setVisibleDuration</code>  |                                         |
+| <b>Result:</b>    | <code>void</code>                |                                         |
+| <b>In:</b>        | <code>TemporalPosition</code>    | <code>initial_temporal_position</code>  |
+| <b>In:</b>        | <code>TemporalPosition</code>    | <code>terminal_temporal_position</code> |
+| <b>Exception:</b> | <code>InvalidTarget</code>       |                                         |
+| <b>Exception:</b> | <code>InvalidParameter</code>    |                                         |
+
+##### Description:
+
+This operation retrieves the presentation priority of an rt-component or a socket.
+
+The `setVisibleDuration` operation triggers the execution of the 'set visible duration' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 51.3.3.
+
+The `initial_temporal_position` parameter specifies the value of the 'initial temporal position' parameter of the 'set visible duration' action.
+
+The `terminal_temporal_position` parameter specifies the value of the 'terminal temporal position' parameter of the 'set visible duration' action.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+The `InvalidParameter` exception is raised when the value of one of the parameters prohibits the normal execution of the action. The `completion_status` member indicates whether the action was completed (with a default value assigned to the inadequate parameter) or not. The `parameter_number` member identifies the rank of the invalid parameter.
+
+#### 7.1.21.9 `setTemporalTermination` operation
+
+##### Synopsis:
+
+|                   |                                     |                                   |
+|-------------------|-------------------------------------|-----------------------------------|
+| <b>Interface:</b> | <code>RtComponentOrSocket</code>    |                                   |
+| <b>Operation:</b> | <code>setTemporalTermination</code> |                                   |
+| <b>Result:</b>    | <code>void</code>                   |                                   |
+| <b>In:</b>        | <code>TemporalTermination</code>    | <code>temporal_termination</code> |
+| <b>Exception:</b> | <code>InvalidTarget</code>          |                                   |
+
+##### Description:
+
+This operation specifies the type of temporal termination when the current temporal position passes the terminal temporal position.
+
+The `setTemporalTermination` operation triggers the execution of the 'set temporal termination' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 52.2.2.
+
+The `temporal_termination` parameter specifies the value of the 'temporal termination' parameter of the 'set temporal termination' action.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+#### 7.1.21.10 setCurrentTemporalPosition operation
+
+##### Synopsis:
+
+|                   |                            |                   |
+|-------------------|----------------------------|-------------------|
+| <b>Interface:</b> | RtComponentOrSocket        |                   |
+| <b>Operation:</b> | setCurrentTemporalPosition |                   |
+| <b>Result:</b>    | void                       |                   |
+| <b>In:</b>        | TemporalPosition           | temporal_position |
+| <b>Exception:</b> | InvalidTarget              |                   |
+| <b>Exception:</b> | InvalidParameter           |                   |
+
+##### Description:
+
+This operation specifies a current temporal position within the VD.
+
+The `setCurrentTemporalPosition` operation triggers the execution of the 'set current temporal position' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 52.2.3.
+
+The `temporal_position` parameter specifies the value of the 'temporal position' parameter of the 'set current temporal position' action.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+The `InvalidParameter` exception is raised when the value of one of the parameters prohibits the normal execution of the action. The `completion_status` member indicates whether the action was completed (with a default value assigned to the inadequate parameter) or not. The `parameter_number` member identifies the rank of the invalid parameter.
+
+#### 7.1.21.11 setSpeed operation
+
+##### Synopsis:
+
+|                   |                     |                     |
+|-------------------|---------------------|---------------------|
+| <b>Interface:</b> | RtComponentOrSocket |                     |
+| <b>Operation:</b> | setSpeed            |                     |
+| <b>Result:</b>    | void                |                     |
+| <b>In:</b>        | Speed               | the_speed           |
+| <b>In:</b>        | unsigned long       | transition_duration |
+| <b>Exception:</b> | InvalidTarget       |                     |
+| <b>Exception:</b> | InvalidParameter    |                     |
+
+##### Description:
+
+This operation defines the speed of the presentation of an rt-component or socket. The effective presentation speed is calculated from this value by the MHEG engine.
+
+The `setSpeed` operation triggers the execution of the 'set speed' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 52.2.5.
+
+The `the_speed` parameter specifies the value of the 'speed' parameter of the 'set speed' action.
+
+The `transition_duration` parameter specifies the value of the 'transition duration' parameter of the 'set speed' action.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+The `InvalidParameter` exception is raised when the value of one of the parameters prohibits the normal execution of the action. The `completion_status` member indicates whether the action was completed (with a default value assigned to the inadequate parameter) or not. The `parameter_number` member identifies the rank of the invalid parameter.
+
+#### 7.1.21.12 setTimestones operation
+
+##### Synopsis:
+
+**Interface:** RtComponentOrSocket  
+**Operation:** setTimestones  
+**Result:** void  
+**In:** sequence<Timestone> timestones  
+**Exception:** InvalidTarget  
+**Exception:** InvalidParameter
+
+##### Description:
+
+This operation specifies a complete set of temporal markers within the perceptible duration of the presentable.
+
+The setTimestones operation triggers the execution of the 'set timestones' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 52.2.6.
+
+The timestones parameter specifies the value of the 'timestones' parameter of the 'set timestones' action.
+
+The InvalidTarget exception is raised when the object instance does not represent a valid target for the normal completion of the action. The period member returns the current period of the target.
+
+The InvalidParameter exception is raised when the value of one of the parameters prohibits the normal execution of the action. The completion\_status member indicates whether the action was completed (with a default value assigned to the inadequate parameter) or not. The parameter\_number member identifies the rank of the invalid parameter.
+
+#### 7.1.21.13 getInitialTemporalPosition operation
+
+##### Synopsis:
+
+**Interface:** RtComponentOrSocket  
+**Operation:** getInitialTemporalPosition  
+**Result:** unsigned long  
+**Exception:** InvalidTarget
+
+##### Description:
+
+This operation retrieves the initial temporal position value of the rt-component or socket. This value is retrieved in Original generic space Generic Temporal Unit (OGTU).
+
+The getInitialTemporalPosition operation triggers the execution of the 'get initial temporal position' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 52.3.2.
+
+The InvalidTarget exception is raised when the object instance does not represent a valid target for the normal completion of the action. The period member returns the current period of the target.
+
+#### 7.1.21.14 getTerminalTemporalPosition operation
+
+##### Synopsis:
+
+**Interface:** RtComponentOrSocket  
+**Operation:** getTerminalTemporalPosition  
+**Result:** unsigned long  
+**Exception:** InvalidTarget
+
+##### Description:
+
+This operation retrieves the terminal temporal position value of the rt-component or socket. This value is retrieved in OGTU.
+
+The `getTerminalTemporalPosition` operation triggers the execution of the 'get terminal temporal position' elementary action with the bound `rt-component` or `socket` as its single target.
+
+The effect of the action on its target, the semantics of its parameters, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 52.3.3.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+#### 7.1.21.15 `getVDLength` operation
+
+##### Synopsis:
+
+|                   |                                                    |
+|-------------------|----------------------------------------------------|
+| <b>Interface:</b> | <code>RtComponentOrSocket</code>                   |
+| <b>Operation:</b> | <code>getVDLength</code>                           |
+| <b>Result:</b>    | <code>unsigned long</code>                         |
+| <b>In:</b>        | <code>GTIndicator</code> <code>gt_indicator</code> |
+| <b>Exception:</b> | <code>InvalidTarget</code>                         |
+
+##### Description:
+
+This operation retrieves the VD length value of the `rt-component` or `socket` either in OG TU or in Relative generic space Generic Temporal Unit (RG TU).
+
+The `getVDLength` operation triggers the execution of the 'get VD length' elementary action with the bound `rt-component` or `socket` as its single target.
+
+The effect of the action on its target, the semantics of its parameters, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 52.3.4.
+
+The `gt_indicator` parameter specifies the value of the 'GT indicator' parameter of the 'get VD length' action.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+#### 7.1.21.16 `getTemporalTermination` operation
+
+##### Synopsis:
+
+|                   |                                     |
+|-------------------|-------------------------------------|
+| <b>Interface:</b> | <code>RtComponentOrSocket</code>    |
+| <b>Operation:</b> | <code>getTemporalTermination</code> |
+| <b>Result:</b>    | <code>TemporalTermination</code>    |
+| <b>Exception:</b> | <code>InvalidTarget</code>          |
+
+##### Description:
+
+This operation retrieves the 'temporal termination' value of the `rt-component` or `socket`.
+
+The `getTemporalTermination` operation triggers the execution of the 'get temporal termination' elementary action with the bound `rt-component` or `socket` as its single target.
+
+The effect of the action on its target, the semantics of its parameters, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 52.3.5.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+#### 7.1.21.17 `getCurrentTemporalPosition` operation
+
+##### Synopsis:
+
+|                   |                                         |
+|-------------------|-----------------------------------------|
+| <b>Interface:</b> | <code>RtComponentOrSocket</code>        |
+| <b>Operation:</b> | <code>getCurrentTemporalPosition</code> |
+| <b>Result:</b>    | <code>unsigned long</code>              |
+| <b>Exception:</b> | <code>InvalidTarget</code>              |
+
+##### Description:
+
+This operation retrieves the current temporal position value of the `rt-component` or `socket`. This value is retrieved in OG TU.
+
+The `getCurrentTemporalPosition` operation triggers the execution of the 'get current temporal position' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 52.3.6.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+#### 7.1.21.18 `getSpeedRate` operation
+
+##### Synopsis:
+
+**Interface:** `RtComponentOrSocket`  
+**Operation:** `getSpeedRate`  
+**Result:** `short`  
+**Exception:** `InvalidTarget`
+
+##### Description:
+
+This operation retrieves the speed rate value of the rt-component or socket. This value is a percentage negative or positive. This speed rate is used to indicate the required change of speed since the Initial Original generic space Generic Temporal Ratio (IOGTR) and also the required direction of the presentation.
+
+The `getSpeedRate` operation triggers the execution of the 'get speed rate' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 52.3.8.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+#### 7.1.21.19 `getOGTR` operation
+
+##### Synopsis:
+
+**Interface:** `RtComponentOrSocket`  
+**Operation:** `getOGTR`  
+**Result:** `unsigned long`  
+**Exception:** `InvalidTarget`
+
+##### Description:
+
+This operation retrieves the Original generic space Generic Temporal Ratio (OGTR) value of the rt-component or socket. This value is a positive or null numeric which corresponds to the number of OGTR to be mapped in one second.
+
+The `getOGTR` operation triggers the execution of the 'get OGTR' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 52.3.9.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+#### 7.1.21.20 `getEffectiveSpeedRate` operation
+
+##### Synopsis:
+
+**Interface:** `RtComponentOrSocket`  
+**Operation:** `getEffectiveSpeedRate`  
+**Result:** `short`  
+**Exception:** `InvalidTarget`
+
+**Description:**
+
+This operation retrieves the effective speed rate value of the rt-component or socket. This value is a percentage negative or positive. This effective speed rate is used to calculate the effective change of speed since the IOGTR and also the effective direction of the presentation.
+
+The `getEffectiveSpeedRate` operation triggers the execution of the 'get effective speed rate' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 52.3.10.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+**7.1.21.21 `getEffectiveOGTR` operation****Synopsis:**
+
+**Interface:** `RtComponentOrSocket`  
+**Operation:** `getEffectiveOGTR`  
+**Result:** `unsigned long`  
+**Exception:** `InvalidTarget`
+
+**Description:**
+
+This operation retrieves the effective OGTR value of the rt-component or socket. This value is a positive or null numeric which corresponds to the effective number of OGTU to be mapped in one second.
+
+The `getEffectiveOGTR` operation triggers the execution of the 'get effective OGTR elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 52.3.11.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+**7.1.21.22 `getTimestoneStatus` operation****Synopsis:**
+
+**Interface:** `RtComponentOrSocket`  
+**Operation:** `getTimestoneStatus`  
+**Result:** `unsigned short`  
+**Exception:** `InvalidTarget`
+
+**Description:**
+
+This operation retrieves the timestone status value of the rt-component or socket.
+
+The `getTimestoneStatus` operation triggers the execution of the 'get timestone status' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 52.3.12.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+**7.1.21.23 `setPerceptibleSizeProjection` operation****Synopsis:**
+
+**Interface:** `RtComponentOrSocket`  
+**Operation:** `setPerceptibleSizeProjection`  
+**Result:** `void`  
+**In:** `PerceptibleSizeProjection` `perceptible_size_projection`  
+**In:** `unsigned long` `transition_duration`  
+**Exception:** `InvalidTarget`  
+**Exception:** `InvalidParameter`
+
+**Description:**
+
+This operation defines the projection of the perceptible size in its RGS.
+
+The `setPerceptibleSizeProjection` operation triggers the execution of the 'set perceptible size projection' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 53.2.1.
+
+The `perceptible_size_projection` parameter specifies the value of the 'perceptible size projection' parameter of the 'set perceptible size projection' action.
+
+The `transition_duration` parameter specifies the value of the 'transition duration' parameter of the 'set perceptible size projection' action.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+The `InvalidParameter` exception is raised when the value of one of the parameters prohibits the normal execution of the action. The `completion_status` member indicates whether the action was completed (with a default value assigned to the inadequate parameter) or not. The `parameter_number` member identifies the rank of the invalid parameter.
+
+**7.1.21.24 setAspectRatio operation****Synopsis:**
+
+|                   |                                  |                        |
+|-------------------|----------------------------------|------------------------|
+| <b>Interface:</b> | <code>RtComponentOrSocket</code> |                        |
+| <b>Operation:</b> | <code>setAspectRatio</code>      |                        |
+| <b>Result:</b>    | <code>void</code>                |                        |
+| <b>In:</b>        | <code>AspectRatio</code>         | <code>preserved</code> |
+| <b>Exception:</b> | <code>InvalidTarget</code>       |                        |
+
+**Description:**
+
+This operation specifies whether in performing the projection of an rt-component or socket in the Channel Generic Space (CGS) [through the chain of mappings Original Generic Space (OGS)-RGS], the ratio between the Perceptible Size (PS) in Original generic space Generic Spatial Unit (OGSU), i.e. the OGS lengths, and the projection in Channel Generic Space Unit (CGSU) of the 'size of the content information' is to be the same for each axis. In such case the aspect ratio is preserved.
+
+The `setAspectRatio` operation triggers the execution of the 'set aspect ratio preserved' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 53.2.3.
+
+The `preserved` parameter specifies the value of the 'preserved' parameter of the 'set aspect ratio preserved' action.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+**7.1.21.25 setVisibleSize operation****Synopsis:**
+
+|                   |                                  |                                  |
+|-------------------|----------------------------------|----------------------------------|
+| <b>Interface:</b> | <code>RtComponentOrSocket</code> |                                  |
+| <b>Operation:</b> | <code>setVisibleSize</code>      |                                  |
+| <b>Result:</b>    | <code>void</code>                |                                  |
+| <b>In:</b>        | <code>VSGS</code>                | <code>the_vsgs</code>            |
+| <b>In:</b>        | <code>VS</code>                  | <code>the_vs</code>              |
+| <b>In:</b>        | <code>unsigned long</code>       | <code>transition_duration</code> |
+| <b>Exception:</b> | <code>InvalidTarget</code>       |                                  |
+| <b>Exception:</b> | <code>InvalidParameter</code>    |                                  |
+
+**Description:**
+
+This operation specifies the Visible Size (VS), which defines which portion of the PS is perceived by the user.
+
+The `setVisibleSize` operation triggers the execution of the 'set visible size' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 53.2.4.
+
+The `the_vsgs` parameter specifies the value of the 'vsgs' parameter of the 'set visible size' action.
+
+The `the_vs` parameter specifies the value of the 'vs' parameter of the 'set visible size' action.
+
+The `transition_duration` parameter specifies the value of the 'transition duration' parameter of the 'set visible size' action.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+The `InvalidParameter` exception is raised when the value of one of the parameters prohibits the normal execution of the action. The `completion_status` member indicates whether the action was completed (with a default value assigned to the inadequate parameter) or not. The `parameter_number` member identifies the rank of the invalid parameter.
+
+**7.1.21.26 setVisibleSizesAdjustment operation****Synopsis:**
+
+|                   |                           |                     |
+|-------------------|---------------------------|---------------------|
+| <b>Interface:</b> | RtComponentOrSocket       |                     |
+| <b>Operation:</b> | setVisibleSizesAdjustment |                     |
+| <b>Result:</b>    | void                      |                     |
+| <b>In:</b>        | sequence<AdjustmentAxis>  | set_of_axes         |
+| <b>In:</b>        | AdjustmentPolicy          | adjustment_policy   |
+| <b>In:</b>        | unsigned long             | transition_duration |
+| <b>Exception:</b> | InvalidTarget             |                     |
+
+**Description:**
+
+This operation specifies the adjustment of a set of VSs on a same axis or on a set of axes. All the VSs to be adjusted needs to be assigned to the same CGS.
+
+The `setVisibleSizesAdjustment` operation triggers the execution of the 'set visible sizes adjustment' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 53.2.5.
+
+The `set_of_axes` parameter specifies the value of the 'set of axes' parameter of the 'set visible sizes adjustment' action.
+
+The `adjustment_policy` parameter specifies the value of the 'adjustment policy' parameter of the 'set visible sizes adjustment' action.
+
+The `transition_duration` parameter specifies the value of the 'transition duration' parameter of the 'set visible sizes adjustment' action.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+**7.1.21.27 setBox operation****Synopsis:**
+
+|                   |                     |     |
+|-------------------|---------------------|-----|
+| <b>Interface:</b> | RtComponentOrSocket |     |
+| <b>Operation:</b> | setBox              |     |
+| <b>Result:</b>    | void                |     |
+| <b>In:</b>        | BoxConstants        | box |
+| <b>Exception:</b> | InvalidTarget       |     |
+
+**Description:**
+
+This operation specifies whether the rt-component or the socket is presented with a box to show the perimeter of the VS.
+
+The `setBox` operation triggers the execution of the 'set box' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 53.2.6.
+
+The `box` parameter specifies the value of the 'box' parameter of the 'set box' action.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+**7.1.21.28 setDefaultBackground operation****Synopsis:**
+
+|                   |                      |                     |
+|-------------------|----------------------|---------------------|
+| <b>Interface:</b> | RtComponentOrSocket  |                     |
+| <b>Operation:</b> | setDefaultBackground |                     |
+| <b>Result:</b>    | void                 |                     |
+| <b>In:</b>        | unsigned short       | background          |
+| <b>In:</b>        | unsigned long        | transition_duration |
+| <b>Exception:</b> | InvalidTarget        |                     |
+| <b>Exception:</b> | InvalidParameter     |                     |
+
+**Description:**
+
+This operation specifies whether the areas within the VS of an rt-component or a socket which are not filled by the presentation process have to be considered as opaque or transparent.
+
+The `setDefaultBackground` operation triggers the execution of the 'set default background' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 53.2.7.
+
+The `background` parameter specifies the value of the 'background' parameter of the 'set default background' action.
+
+The `transition_duration` parameter specifies the value of the 'transition duration' parameter of the 'set default background' action.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+The `InvalidParameter` exception is raised when the value of one of the parameters prohibits the normal execution of the action. The `completion_status` member indicates whether the action was completed (with a default value assigned to the inadequate parameter) or not. The `parameter_number` member identifies the rank of the invalid parameter.
+
+**7.1.21.29 setAttachmentPoint operation****Synopsis:**
+
+|                   |                     |           |
+|-------------------|---------------------|-----------|
+| <b>Interface:</b> | RtComponentOrSocket |           |
+| <b>Operation:</b> | setAttachmentPoint  |           |
+| <b>Result:</b>    | void                |           |
+| <b>In:</b>        | AttachmentPointType | type      |
+| <b>In:</b>        | AttachmentPoint     | positions |
+| <b>Exception:</b> | InvalidTarget       |           |
+| <b>Exception:</b> | InvalidParameter    |           |
+
+**Description:**
+
+This operation specifies one of the following AP: Perceptible Size Attachment Point (PSAP), Visible Size Internal Attachment Point (VSIAP) or Visible Size External Attachment Point (VSEAP).
+
+The `setAttachmentPoint` operation triggers the execution of the 'set attachment point' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 53.2.8.
+
+The `type` parameter specifies the value of the 'type' parameter of the 'set attachment point' action.
+
+The `positions` parameter specifies the value of the 'positions' parameter of the 'set attachment point' action.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+The `InvalidParameter` exception is raised when the value of one of the parameters prohibits the normal execution of the action. The `completion_status` member indicates whether the action was completed (with a default value assigned to the inadequate parameter) or not. The `parameter_number` member identifies the rank of the invalid parameter.
+
+#### 7.1.21.30 `setAttachmentPointPosition` operation
+
+##### Synopsis:
+
+|                   |                                         |                                    |
+|-------------------|-----------------------------------------|------------------------------------|
+| <b>Interface:</b> | <code>RtComponentOrSocket</code>        |                                    |
+| <b>Operation:</b> | <code>setAttachmentPointPosition</code> |                                    |
+| <b>Result:</b>    | <code>void</code>                       |                                    |
+| <b>In:</b>        | <code>AttachmentPointType</code>        | <code>type</code>                  |
+| <b>In:</b>        | <code>ReferenceType</code>              | <code>vseap_reference_point</code> |
+| <b>In:</b>        | <code>Lengths</code>                    | <code>the_lengths</code>           |
+| <b>In:</b>        | <code>unsigned long</code>              | <code>transition_duration</code>   |
+| <b>Exception:</b> | <code>InvalidTarget</code>              |                                    |
+| <b>Exception:</b> | <code>InvalidParameter</code>           |                                    |
+
+##### Description:
+
+This operation specifies the position of the VSIAP relatively to the PSAP, or the position of the VSEAP in its RGS relatively to the origin or to another VSEAP.
+
+The `setAttachmentPointPosition` operation triggers the execution of the 'set attachment point position' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 53.2.9.
+
+The `type` parameter specifies the value of the 'type' parameter of the 'set attachment point position' action.
+
+The `vseap_reference_point` parameter specifies the value of the 'vseap reference point' parameter of the 'set attachment point position' action.
+
+The `the_lengths` parameter specifies the value of the 'lengths' parameter of the 'set attachment point position' action.
+
+The `transition_duration` parameter specifies the value of the 'transition duration' parameter of the 'set attachment point position' action.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+The `InvalidParameter` exception is raised when the value of one of the parameters prohibits the normal execution of the action. The `completion_status` member indicates whether the action was completed (with a default value assigned to the inadequate parameter) or not. The `parameter_number` member identifies the rank of the invalid parameter.
+
+#### 7.1.21.31 `setVisibleSizesAlignment` operation
+
+##### Synopsis:
+
+|                   |                                       |                                  |
+|-------------------|---------------------------------------|----------------------------------|
+| <b>Interface:</b> | <code>RtComponentOrSocket</code>      |                                  |
+| <b>Operation:</b> | <code>setVisibleSizesAlignment</code> |                                  |
+| <b>Result:</b>    | <code>void</code>                     |                                  |
+| <b>In:</b>        | <code>SizeBorder</code>               | <code>size_border</code>         |
+| <b>In:</b>        | <code>long</code>                     | <code>interval</code>            |
+| <b>In:</b>        | <code>unsigned long</code>            | <code>transition_duration</code> |
+| <b>Exception:</b> | <code>InvalidTarget</code>            |                                  |
+
+**Description:**
+
+This operation specifies the alignment of a set of VSs. The VSs are aligned on a border and an interval between two VSs may be provided. All the VSs to be aligned needs to be assigned to the same CGS.
+
+The `setVisibleSizesAlignment` operation triggers the execution of the 'set visible sizes alignment' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 53.2.10.
+
+The `size_border` parameter specifies the value of the 'size border' parameter of the 'set visible sizes alignment' action.
+
+The `interval` parameter specifies the value of the 'interval' parameter of the 'set visible sizes alignment' action.
+
+The `transition_duration` parameter specifies the value of the 'transition duration' parameter of the 'set visible sizes alignment' action.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+**7.1.21.32 `setMovingAbility` operation****Synopsis:**
+
+|                   |                                  |                             |
+|-------------------|----------------------------------|-----------------------------|
+| <b>Interface:</b> | <code>RtComponentOrSocket</code> |                             |
+| <b>Operation:</b> | <code>setMovingAbility</code>    |                             |
+| <b>Result:</b>    | <code>void</code>                |                             |
+| <b>In:</b>        | <code>UserControls</code>        | <code>moving_ability</code> |
+| <b>Exception:</b> | <code>InvalidTarget</code>       |                             |
+
+**Description:**
+
+This operation specifies whether the user is able to move or not to move the VS of the targets in their CGS.
+
+The `setMovingAbility` operation triggers the execution of the 'set moving ability' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 53.2.11.
+
+The `moving_ability` parameter specifies the value of the 'moving ability' parameter of the 'set moving ability' action.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+**7.1.21.33 `setResizingAbility` operation****Synopsis:**
+
+|                   |                                  |                               |
+|-------------------|----------------------------------|-------------------------------|
+| <b>Interface:</b> | <code>RtComponentOrSocket</code> |                               |
+| <b>Operation:</b> | <code>setResizingAbility</code>  |                               |
+| <b>Result:</b>    | <code>void</code>                |                               |
+| <b>In:</b>        | <code>UserControls</code>        | <code>resizing_ability</code> |
+| <b>Exception:</b> | <code>InvalidTarget</code>       |                               |
+
+**Description:**
+
+This operation specifies whether the user is able to resize or not the VS of the targets in their CGS.
+
+The `setResizingAbility` operation triggers the execution of the 'set resizing ability' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 53.2.12.
+
+The `resizing_ability` parameter specifies the value of the 'resizing ability' parameter of the 'set resizing ability' action.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+#### 7.1.21.34 `setScalingAbility` operation
+
+##### Synopsis:
+
+|                   |                                  |                              |
+|-------------------|----------------------------------|------------------------------|
+| <b>Interface:</b> | <code>RtComponentOrSocket</code> |                              |
+| <b>Operation:</b> | <code>setScalingAbility</code>   |                              |
+| <b>Result:</b>    | <code>void</code>                |                              |
+| <b>In:</b>        | <code>UserControls</code>        | <code>scaling_ability</code> |
+| <b>Exception:</b> | <code>InvalidTarget</code>       |                              |
+
+##### Description:
+
+This operation specifies whether the user is able to scale or not the PS of the targets in their CGS.
+
+The `setScalingAbility` operation triggers the execution of the 'set scaling ability' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 53.2.13.
+
+The `scaling_ability` parameter specifies the value of the 'scaling ability' parameter of the 'set scaling ability' action.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+#### 7.1.21.35 `setScrollingAbility` operation
+
+##### Synopsis:
+
+|                   |                                  |                                |
+|-------------------|----------------------------------|--------------------------------|
+| <b>Interface:</b> | <code>RtComponentOrSocket</code> |                                |
+| <b>Operation:</b> | <code>setScrollingAbility</code> |                                |
+| <b>Result:</b>    | <code>void</code>                |                                |
+| <b>In:</b>        | <code>UserControls</code>        | <code>scrolling_ability</code> |
+| <b>Exception:</b> | <code>InvalidTarget</code>       |                                |
+
+##### Description:
+
+This operation specifies whether the user is able to scroll or not the PS through the VS of the targets in their CGS.
+
+The `setScrollingAbility` operation triggers the execution of the 'set scrolling ability' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 53.2.14.
+
+The `scrolling_ability` parameter specifies the value of the 'scrolling ability' parameter of the 'set scrolling ability' action.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+#### 7.1.21.36 `getGSR` operation
+
+##### Synopsis:
+
+|                   |                                  |  |
+|-------------------|----------------------------------|--|
+| <b>Interface:</b> | <code>RtComponentOrSocket</code> |  |
+| <b>Operation:</b> | <code>getGSR</code>              |  |
+| <b>Result:</b>    | <code>unsigned short</code>      |  |
+| <b>Exception:</b> | <code>InvalidTarget</code>       |  |
+
+**Description:**
+
+This operation retrieves the Generic Spatial Ratio (GSR) value of the OGS of the rt-component or socket. This ratio defines the number of OGSU which are to be mapped in one Relative generic space Generic Spatial Unit (RGSU).
+
+The `getGSR` operation triggers the execution of the 'get GSR' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 53.4.1.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+**7.1.21.37 getPS operation****Synopsis:**
+
+|                   |                                  |                 |
+|-------------------|----------------------------------|-----------------|
+| <b>Interface:</b> | <code>RtComponentOrSocket</code> |                 |
+| <b>Operation:</b> | <code>getPS</code>               |                 |
+| <b>Result:</b>    | <code>SpecifiedPosition</code>   |                 |
+| <b>In:</b>        | <code>GSIndicator</code>         | <code>gs</code> |
+| <b>Exception:</b> | <code>InvalidTarget</code>       |                 |
+
+**Description:**
+
+This operation retrieves the PS value of the rt-component or socket either in OGSU or in RGSU.
+
+The `getPS` operation triggers the execution of the 'get PS' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 53.4.2.
+
+The `gs` parameter specifies the value of the 'gs' parameter of the 'get PS' action.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+**7.1.21.38 getAspectRatio operation****Synopsis:**
+
+|                   |                                  |  |
+|-------------------|----------------------------------|--|
+| <b>Interface:</b> | <code>RtComponentOrSocket</code> |  |
+| <b>Operation:</b> | <code>getAspectRatio</code>      |  |
+| <b>Result:</b>    | <code>AspectRatio</code>         |  |
+| <b>Exception:</b> | <code>InvalidTarget</code>       |  |
+
+**Description:**
+
+This operation retrieves the aspect ratio value of the PS of the rt-component or socket.
+
+The `getAspectRatio` operation triggers the execution of the 'get aspect ratio' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 53.4.4.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+**7.1.21.39 getPSAP operation****Synopsis:**
+
+|                   |                                  |                         |
+|-------------------|----------------------------------|-------------------------|
+| <b>Interface:</b> | <code>RtComponentOrSocket</code> |                         |
+| <b>Operation:</b> | <code>getPSAP</code>             |                         |
+| <b>Result:</b>    | <code>SpecifiedPosition</code>   |                         |
+| <b>In:</b>        | <code>PointType</code>           | <code>point_type</code> |
+| <b>Exception:</b> | <code>InvalidTarget</code>       |                         |
+
+**Description:**
+
+This operation retrieves the PSAP value of the rt-component or socket.
+
+The `getPSAP` operation triggers the execution of the 'get PSAP' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 53.4.5.
+
+The `point_type` parameter specifies the value of the 'point type' parameter of the 'get PSAP' action.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+**7.1.21.40 getVSGS operation****Synopsis:**
+
+**Interface:** RtComponentOrSocket  
+**Operation:** getVSGS  
+**Result:** VSGS  
+**Exception:** InvalidTarget
+
+**Description:**
+
+This operation retrieves the Visible Size Generic Space (VSGS) value of the rt-component or socket.
+
+The `getVSGS` operation triggers the execution of the 'get VSGS' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 53.4.6.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+**7.1.21.41 getVS operation****Synopsis:**
+
+**Interface:** RtComponentOrSocket  
+**Operation:** getVS  
+**Result:** SpecifiedPosition  
+**Exception:** InvalidTarget
+
+**Description:**
+
+This operation retrieves the VS value of the rt-component or socket in Visible Size Generic Spatial Unit (VSGSU).
+
+The `getVS` operation triggers the execution of the 'get vs' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 53.4.7.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+**7.1.21.42 getBox operation****Synopsis:**
+
+**Interface:** RtComponentOrSocket  
+**Operation:** getBox  
+**Result:** BoxConstants  
+**Exception:** InvalidTarget
+
+**Description:**
+
+This operation retrieves the visible size box value of the rt-component or socket.
+
+The `getBox` operation triggers the execution of the 'get box' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 53.4.8.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+**7.1.21.43 `getDefaultBackground` operation****Synopsis:**
+
+**Interface:** `RtComponentOrSocket`  
+**Operation:** `getDefaultBackground`  
+**Result:** `unsigned short`  
+**Exception:** `InvalidTarget`
+
+**Description:**
+
+This operation retrieves the default background value of the VS of the rt-component or socket.
+
+The `getDefaultBackground` operation triggers the execution of the 'get default background' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 53.4.9.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+**7.1.21.44 `getVSIAP` operation****Synopsis:**
+
+**Interface:** `RtComponentOrSocket`  
+**Operation:** `getVSIAP`  
+**Result:** `SpecifiedPosition`  
+**In:** `PointType` `point_type`  
+**Exception:** `InvalidTarget`
+
+**Description:**
+
+This operation retrieves the VSIAP value of the rt-component or socket.
+
+The `getVSIAP` operation triggers the execution of the 'get VSIAP' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 53.4.10.
+
+The `point_type` parameter specifies the value of the 'point type' parameter of the 'get VSIAP' action.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+**7.1.21.45 `getVSIAPPosition` operation****Synopsis:**
+
+**Interface:** `RtComponentOrSocket`  
+**Operation:** `getVSIAPPosition`  
+**Result:** `SpecifiedPosition`  
+**Exception:** `InvalidTarget`
+
+**Description:**
+
+This operation retrieves the VSIAP position value of the rt-component or socket. This is used to position the VSIAP relatively to the PSAP.
+
+The `getVSIAPPosition` operation triggers the execution of the 'get VSIAP position' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 53.4.11.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+**7.1.21.46 `getVSEAP` operation****Synopsis:**
+
+|                   |                                  |                         |
+|-------------------|----------------------------------|-------------------------|
+| <b>Interface:</b> | <code>RtComponentOrSocket</code> |                         |
+| <b>Operation:</b> | <code>getVSEAP</code>            |                         |
+| <b>Result:</b>    | <code>SpecifiedPosition</code>   |                         |
+| <b>In:</b>        | <code>PointerType</code>         | <code>point_type</code> |
+| <b>Exception:</b> | <code>InvalidTarget</code>       |                         |
+
+**Description:**
+
+This operation retrieves the VSEAP value of the rt-component or socket.
+
+The `getVSEAP` operation triggers the execution of the 'get VSEAP' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 53.4.12.
+
+The `point_type` parameter specifies the value of the 'point type' parameter of the 'get VSEAP' action.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+**7.1.21.47 `getVSEAPPosition` operation****Synopsis:**
+
+|                   |                                  |                              |
+|-------------------|----------------------------------|------------------------------|
+| <b>Interface:</b> | <code>RtComponentOrSocket</code> |                              |
+| <b>Operation:</b> | <code>getVSEAPPosition</code>    |                              |
+| <b>Result:</b>    | <code>SpecifiedPosition</code>   |                              |
+| <b>In:</b>        | <code>ReferencePoint</code>      | <code>reference_point</code> |
+| <b>Exception:</b> | <code>InvalidTarget</code>       |                              |
+
+**Description:**
+
+This operation retrieves the VSEAP position value of the rt-component or socket relatively to a reference point. This is used to position the VSEAP relatively to the PSAP.
+
+The `getVSEAPPosition` operation triggers the execution of the 'get VSEAP position' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 53.4.13.
+
+The `reference_point` parameter specifies the value of the 'reference point' parameter of the 'get VSEAP position' action.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+#### 7.1.21.48 `getMovingAbility` operation
+
+##### Synopsis:
+
+**Interface:** `RtComponentOrSocket`  
+**Operation:** `getMovingAbility`  
+**Result:** `UserControls`  
+**Exception:** `InvalidTarget`
+
+##### Description:
+
+This operation retrieves the moving ability value of the rt-component or socket.
+
+The `getMovingAbility` operation triggers the execution of the 'get moving ability' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 53.4.14.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+#### 7.1.21.49 `getResizingAbility` operation
+
+##### Synopsis:
+
+**Interface:** `RtComponentOrSocket`  
+**Operation:** `getResizingAbility`  
+**Result:** `UserControls`  
+**Exception:** `InvalidTarget`
+
+##### Description:
+
+This operation retrieves the resizing ability value of the rt-component or socket.
+
+The `getResizingAbility` operation triggers the execution of the 'get resizing ability' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 53.4.15.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+#### 7.1.21.50 `getScalingAbility` operation
+
+##### Synopsis:
+
+**Interface:** `RtComponentOrSocket`  
+**Operation:** `getScalingAbility`  
+**Result:** `UserControls`  
+**Exception:** `InvalidTarget`
+
+##### Description:
+
+This operation retrieves the scaling ability value of the rt-component or socket.
+
+The `getScalingAbility` operation triggers the execution of the 'get scaling ability' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 53.4.16.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+### 7.1.21.51 `getScrollingAbility` operation
+
+#### Synopsis:
+
+**Interface:** `RtComponentOrSocket`  
+**Operation:** `getScrollingAbility`  
+**Result:** `UserControls`  
+**Exception:** `InvalidTarget`
+
+#### Description:
+
+This operation retrieves the scrolling ability value of the rt-component or socket.
+
+The `getScrollingAbility` operation triggers the execution of the 'get scrolling ability' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 53.4.17.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+### 7.1.21.52 `setSelectability` operation
+
+#### Synopsis:
+
+**Interface:** `RtComponentOrSocket`  
+**Operation:** `setSelectability`  
+**Result:** `void`  
+**In:** `unsigned short` `min_number_of_selections`  
+**In:** `unsigned short` `max_number_of_selections`  
+**Exception:** `InvalidTarget`  
+**Exception:** `InvalidParameter`
+
+#### Description:
+
+This operation assigns a 'minimum number of selections required' value and a 'maximum number of selections required' value to an rt-component or a socket. The MHEG engine calculates the 'selectability' value of the rt-component or socket from these two values. The 'effective selectability' value of the rt-component or socket is also calculated by the MHEG engine from this 'selectability' value and the 'effective selectability' value of the parent of the rt-component or socket.
+
+The `setSelectability` operation triggers the execution of the 'set selectability' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 57.2.1.
+
+The `min_number_of_selections` parameter specifies the value of the 'min number of selections' parameter of the 'set selectability' action.
+
+The `max_number_of_selections` parameter specifies the value of the 'max number of selections' parameter of the 'set selectability' action.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+The `InvalidParameter` exception is raised when the value of one of the parameters prohibits the normal execution of the action. The `completion_status` member indicates whether the action was completed (with a default value assigned to the inadequate parameter) or not. The `parameter_number` member identifies the rank of the invalid parameter.
+
+### 7.1.21.53 `setSelectionStatus` operation
+
+#### Synopsis:
+
+**Interface:** `RtComponentOrSocket`  
+**Operation:** `setSelectionStatus`  
+**Result:** `void`  
+**In:** `SelectionStatusValue` `selection_state`  
+**Exception:** `InvalidTarget`
+
+**Description:**
+
+This operation assigns a value to the 'selection status' of an rt-component or a socket.
+
+The `setSelectionStatus` operation triggers the execution of the 'set selection status' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 57.2.2.
+
+The `selection_state` parameter specifies the value of the 'selection state' parameter of the 'set selection status' action.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+**7.1.21.54 setSelectionPresentationEffectResponsibility operation****Synopsis:**
+
+|                   |                                                           |                                 |
+|-------------------|-----------------------------------------------------------|---------------------------------|
+| <b>Interface:</b> | <code>RtComponentOrSocket</code>                          |                                 |
+| <b>Operation:</b> | <code>setSelectionPresentationEffectResponsibility</code> |                                 |
+| <b>Result:</b>    | <code>void</code>                                         |                                 |
+| <b>In:</b>        | <code>Responsibility</code>                               | <code>the_responsibility</code> |
+| <b>Exception:</b> | <code>InvalidTarget</code>                                |                                 |
+
+**Description:**
+
+This operation assigns a value to the 'selection presentation effect responsibility' of an rt-component or a socket. This attribute indicates if it is the MHEG engine or the author who is responsible for reflecting a new state of the rt-component or socket as its single target
+
+The `setSelectionPresentationEffectResponsibility` operation triggers the execution of the 'set selection presentation effect responsibility' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 57.2.3.
+
+The `the_responsibility` parameter specifies the value of the 'responsibility' parameter of the 'set selection presentation effect responsibility' action.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+**7.1.21.55 getSelectability operation****Synopsis:**
+
+|                   |                                  |                                       |
+|-------------------|----------------------------------|---------------------------------------|
+| <b>Interface:</b> | <code>RtComponentOrSocket</code> |                                       |
+| <b>Operation:</b> | <code>getSelectability</code>    |                                       |
+| <b>Result:</b>    | <code>void</code>                |                                       |
+| <b>Out:</b>       | <code>unsigned short</code>      | <code>min_number_of_selections</code> |
+| <b>Out:</b>       | <code>unsigned short</code>      | <code>max_number_of_selections</code> |
+| <b>Exception:</b> | <code>InvalidTarget</code>       |                                       |
+
+**Description:**
+
+This operation retrieves the 'minimum number of selections required' and the 'maximum number of selections required'. If the 'maximum number of selections required' is equal to 0, the 'selectability' of the rt-component or socket is 'not selectable'.
+
+The `getSelectability` operation triggers the execution of the 'get selectability' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 57.3.1.
+
+The `min_number_of_selections` parameter specifies the value of the 'min number of selections' parameter of the 'get selectability' action.
+
+The `max_number_of_selections` parameter specifies the value of the 'max number of selections' parameter of the 'get selectability' action.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+#### 7.1.21.56 `getEffectiveSelectability` operation
+
+##### Synopsis:
+
+**Interface:** `RtComponentOrSocket`  
+**Operation:** `getEffectiveSelectability`  
+**Result:** `EffectiveSelectability`  
+**Exception:** `InvalidTarget`
+
+##### Description:
+
+This operation retrieves the 'effective selectability' attribute value of the rt-component or socket.
+
+The `getEffectiveSelectability` operation triggers the execution of the 'get effective selectability' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 57.3.2.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+#### 7.1.21.57 `getSelectionStatus` operation
+
+##### Synopsis:
+
+**Interface:** `RtComponentOrSocket`  
+**Operation:** `getSelectionStatus`  
+**Result:** `SelectionStatusValue`  
+**Exception:** `InvalidTarget`
+
+##### Description:
+
+This operation retrieves the 'selection status' value of the rt-component or socket.
+
+The `getSelectionStatus` operation triggers the execution of the 'get selection status' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 57.3.3.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+#### 7.1.21.58 `getSelectionMode` operation
+
+##### Synopsis:
+
+**Interface:** `RtComponentOrSocket`  
+**Operation:** `getSelectionMode`  
+**Result:** `SelectionModeValue`  
+**Exception:** `InvalidTarget`
+
+##### Description:
+
+This operation retrieves the 'selection mode' attribute value of the rt-component or socket.
+
+The `getSelectionMode` operation triggers the execution of the 'get selection mode' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 57.3.4.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+### 7.1.21.59 `getSelectionPresentationEffectResponsibility` operation
+
+#### Synopsis:
+
+**Interface:** `RtComponentOrSocket`  
+**Operation:** `getSelectionPresentationEffectResponsibility`  
+**Result:** `Responsibility`  
+**Exception:** `InvalidTarget`
+
+#### Description:
+
+This operation retrieves the 'selection presentation effect responsibility' attribute value of the rt-component or socket.
+
+The `getSelectionPresentationEffectResponsibility` operation triggers the execution of the 'get selection presentation effect responsibility' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 57.3.6.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+### 7.1.21.60 `setModifiability` operation
+
+#### Synopsis:
+
+**Interface:** `RtComponentOrSocket`  
+**Operation:** `setModifiability`  
+**Result:** `void`  
+**In:** `unsigned short` `min_number_of_modifications`  
+**In:** `unsigned short` `max_number_of_modifications`  
+**Exception:** `InvalidTarget`  
+**Exception:** `InvalidParameter`
+
+#### Description:
+
+This operation assigns a 'minimum number of modifications required' value and a 'maximum number of modifications required' value to an rt-component or a socket. The MHEG engine calculates the 'modifiability' value of the rt-component or socket from these two values. The 'effective modifiability' value of the rt-component or socket is also calculated by the MHEG engine from this 'modifiability' value and the 'effective modifiability' value of the parent of the rt-component or socket.
+
+The `setModifiability` operation triggers the execution of the 'set modifiability' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 58.2.1.
+
+The `min_number_of_modifications` parameter specifies the value of the 'min number of modifications' parameter of the 'set modifiability' action.
+
+The `max_number_of_modifications` parameter specifies the value of the 'max number of modifications' parameter of the 'set modifiability' action.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+The `InvalidParameter` exception is raised when the value of one of the parameters prohibits the normal execution of the action. The `completion_status` member indicates whether the action was completed (with a default value assigned to the inadequate parameter) or not. The `parameter_number` member identifies the rank of the invalid parameter.
+
+#### 7.1.21.61 setModificationStatus **operation**
+
+##### Synopsis:
+
+**Interface:** RtComponentOrSocket  
+**Operation:** setModificationStatus  
+**Result:** void  
+**In:** ModificationStatusValue modification\_state  
+**Exception:** InvalidTarget
+
+##### Description:
+
+This operation assigns a value to the 'modification status' of an rt-component or a socket.
+
+The setModificationStatus operation triggers the execution of the 'set modification status' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 58.2.2.
+
+The modification\_state parameter specifies the value of the 'modification state' parameter of the 'set modification status' action.
+
+The InvalidTarget exception is raised when the object instance does not represent a valid target for the normal completion of the action. The period member returns the current period of the target.
+
+#### 7.1.21.62 setModificationPresentationEffectResponsibility **operation**
+
+##### Synopsis:
+
+**Interface:** RtComponentOrSocket  
+**Operation:** setModificationPresentationEffectResponsibility  
+**Result:** void  
+**In:** Responsibility the\_responsibility  
+**Exception:** InvalidTarget
+
+##### Description:
+
+This operation assigns a value to the 'modification presentation effect responsibility' of an rt-component or a socket. This attribute indicates if it is the MHEG engine or the author who is responsible for reflecting a new state of the component or socket.
+
+The setModificationPresentationEffectResponsibility operation triggers the execution of the 'set modification presentation effect responsibility' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 58.2.3.
+
+The the\_responsibility parameter specifies the value of the 'responsibility' parameter of the 'set modification presentation effect responsibility' action.
+
+The InvalidTarget exception is raised when the object instance does not represent a valid target for the normal completion of the action. The period member returns the current period of the target.
+
+#### 7.1.21.63 getModifiability **operation**
+
+##### Synopsis:
+
+**Interface:** RtComponentOrSocket  
+**Operation:** getModifiability  
+**Result:** void  
+**Out:** unsigned short min\_numbers\_of\_modifications  
+**Out:** unsigned short max\_numbers\_of\_modifications  
+**Exception:** InvalidTarget
+
+##### Description:
+
+This operation retrieves the 'minimum number of modifications required' and the 'maximum number of modifications required'. If the 'maximum number of modifications required' is equal to 0 the 'modifiability' of the rt-component or socket is 'not modifiable'.
+
+The `getModifiability` operation triggers the execution of the 'get modifiability' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 58.3.1.
+
+The `min_numbers_of_modifications` parameter specifies the value of the 'min numbers of modifications' parameter of the 'get modifiability' action.
+
+The `max_numbers_of_modifications` parameter specifies the value of the 'max numbers of modifications' parameter of the 'get modifiability' action.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+#### **7.1.21.64     `getEffectiveModifiability` operation**
+
+##### **Synopsis:**
+
+**Interface:**         `RtComponentOrSocket`  
+**Operation:**        `getEffectiveModifiability`  
+**Result:**            `EffectiveModifiability`  
+**Exception:**        `InvalidTarget`
+
+##### **Description:**
+
+This operation retrieves the 'effective modifiability' attribute value of the rt-component or socket.
+
+The `getEffectiveModifiability` operation triggers the execution of the 'get effective modifiability' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 58.3.2.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+#### **7.1.21.65     `getModificationStatus` operation**
+
+##### **Synopsis:**
+
+**Interface:**         `RtComponentOrSocket`  
+**Operation:**        `getModificationStatus`  
+**Result:**            `ModificationStatusValue`  
+**Exception:**        `InvalidTarget`
+
+##### **Description:**
+
+This operation retrieves the 'modification status' value of the rt-component or socket.
+
+The `getModificationStatus` operation triggers the execution of the 'get modification status' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 58.3.3.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+#### **7.1.21.66     `getModificationMode` operation**
+
+##### **Synopsis:**
+
+**Interface:**         `RtComponentOrSocket`  
+**Operation:**        `getModificationMode`  
+**Result:**            `ModificationModeValue`  
+**Exception:**        `InvalidTarget`
+
+##### **Description:**
+
+This operation retrieves the 'modification mode' attribute value of the rt-component or socket.
+
+The `getModificationMode` operation triggers the execution of the 'get modification mode' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 58.3.4.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+#### **7.1.21.67     `getModificationPresentationEffectResponsibility` operation**
+
+##### **Synopsis:**
+
+**Interface:**            `RtComponentOrSocket`  
+**Operation:**          `getModificationPresentationEffectResponsibility`  
+**Result:**             `Responsibility`  
+**Exception:**          `InvalidTarget`
+
+##### **Description:**
+
+This operation retrieves the 'modification presentation effect responsibility' attribute value of the rt-component or socket.
+
+The `getModificationPresentationEffectResponsibility` operation triggers the execution of the 'get modification presentation effect responsibility' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 58.3.6.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+#### **7.1.21.68     `setNoInteractionStyle` operation**
+
+##### **Synopsis:**
+
+**Interface:**            `RtComponentOrSocket`  
+**Operation:**          `setNoInteractionStyle`  
+**Result:**             `void`  
+**Exception:**          `InvalidTarget`
+
+##### **Description:**
+
+This operation deassigns the currently assigned interaction style to an rt-component or a socket.
+
+The `setNoInteractionStyle` operation triggers the execution of the 'set no style' elementary action with the bound rt-component or socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 59.2.6.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+#### **7.1.21.69     IDL description**
+
+```
+interface RtComponentOrSocket {  
+    void  
+        setRGS(  
+            in ChannelIdentifier  
+                channel_identifier)  
+    raises(InvalidTarget);  
+  
+    RGSValue  
+        getRGS()  
+    raises(InvalidTarget);  
+}
+```
+
+```
+
+void
+    setOpacity(
+        in unsigned short
+            opacity_rate,
+        in unsigned long
+            transition_duration)
+raises(InvalidTarget);
+
+void
+    setPresentationPriority(
+        in PresentationPriority
+            presentation_priority,
+        in unsigned long
+            transition_duration)
+raises(InvalidTarget, InvalidParameter);
+
+unsigned short
+    getOpacity()
+raises(InvalidTarget);
+
+unsigned short
+    getEffectiveOpacity()
+raises(InvalidTarget);
+
+unsigned short
+    getPresentationPriority()
+raises(InvalidTarget);
+
+void
+    setVisibleDuration(
+        in TemporalPosition
+            initial_temporal_position,
+        in TemporalPosition
+            terminal_temporal_position)
+raises(InvalidTarget, InvalidParameter);
+
+void
+    setTemporalTermination(
+        in TemporalTermination
+            temporal_termination)
+raises(InvalidTarget);
+
+void
+    setCurrentTemporalPosition(
+        in TemporalPosition
+            temporal_position)
+raises(InvalidTarget, InvalidParameter);
+
+void
+    setSpeed(
+        in Speed
+            the_speed,
+        in unsigned long
+            transition_duration)
+raises(InvalidTarget, InvalidParameter);
+
+void
+    setTimestones(
+        in sequence<Timestone>
+            timestones)
+raises(InvalidTarget, InvalidParameter);
+
+unsigned long
+    getInitialTemporalPosition()
+raises(InvalidTarget);
+
+unsigned long
+    getTerminalTemporalPosition()
+raises(InvalidTarget);
+
+unsigned long
+    getVDLength(
+        in GTIndicator
+            gt_indicator)
+raises(InvalidTarget);
+
+```
+
+```
+
+TemporalTermination
+    getTemporalTermination()
+raises(InvalidTarget);
+
+unsigned long
+    getCurrentTemporalPosition()
+raises(InvalidTarget);
+
+short
+    getSpeedRate()
+raises(InvalidTarget);
+
+unsigned long
+    getOGTR()
+raises(InvalidTarget);
+
+short
+    getEffectiveSpeedRate()
+raises(InvalidTarget);
+
+unsigned long
+    getEffectiveOGTR()
+raises(InvalidTarget);
+
+unsigned short
+    getTimestoneStatus()
+raises(InvalidTarget);
+
+void
+    setPerceptibleSizeProjection(
+        in PerceptibleSizeProjection
+            perceptible_size_projection,
+        in unsigned long
+            transition_duration)
+raises(InvalidTarget, InvalidParameter);
+
+void
+    setAspectRatio(
+        in AspectRatio
+            preserved)
+raises(InvalidTarget);
+
+void
+    setVisibleSize(
+        in VSGS
+            the_vsgs,
+        in VS
+            the_vs,
+        in unsigned long
+            transition_duration)
+raises(InvalidTarget, InvalidParameter);
+
+void
+    setVisibleSizesAdjustment(
+        in sequence<AdjustmentAxis>
+            set_of_axes,
+        in AdjustmentPolicy
+            adjustment_policy,
+        in unsigned long
+            transition_duration)
+raises(InvalidTarget);
+
+void
+    setBox(
+        in BoxConstants
+            box)
+raises(InvalidTarget);
+
+void
+    setDefaultBackground(
+        in unsigned short
+            background,
+        in unsigned long
+            transition_duration)
+raises(InvalidTarget, InvalidParameter);
+
+```
+
+```
+
+void
+    setAttachmentPoint(
+        in AttachmentPointType
+            type,
+        in AttachmentPoint
+            positions)
+raises(InvalidTarget, InvalidParameter);
+
+void
+    setAttachmentPointPosition(
+        in AttachmentPointType
+            type,
+        in ReferenceType
+            vseap_reference_point,
+        in Lengths
+            the_lengths,
+        in unsigned long
+            transition_duration)
+raises(InvalidTarget, InvalidParameter);
+
+void
+    setVisibleSizesAlignment(
+        in SizeBorder
+            size_border,
+        in long
+            interval,
+        in unsigned long
+            transition_duration)
+raises(InvalidTarget);
+
+void
+    setMovingAbility(
+        in UserControls
+            moving_ability)
+raises(InvalidTarget);
+
+void
+    setResizingAbility(
+        in UserControls
+            resizing_ability)
+raises(InvalidTarget);
+
+void
+    setScalingAbility(
+        in UserControls
+            scaling_ability)
+raises(InvalidTarget);
+
+void
+    setScrollingAbility(
+        in UserControls
+            scrolling_ability)
+raises(InvalidTarget);
+
+unsigned short
+    getGSR()
+raises(InvalidTarget);
+
+SpecifiedPosition
+    getPS(
+        in GSIndicator
+            gs)
+raises(InvalidTarget);
+
+AspectRatio
+    getAspectRatio()
+raises(InvalidTarget);
+
+SpecifiedPosition
+    getPSAP(
+        in PointType
+            point_type)
+raises(InvalidTarget);
+
+```
+
+```
+
+VSGS
+    getVSGS()
+raises(InvalidTarget);
+
+SpecifiedPosition
+    getVS()
+raises(InvalidTarget);
+
+BoxConstants
+    getBox()
+raises(InvalidTarget);
+
+unsigned short
+    getDefaultBackground()
+raises(InvalidTarget);
+
+SpecifiedPosition
+    getVSIAP(
+        in PointType
+            point_type)
+raises(InvalidTarget);
+
+SpecifiedPosition
+    getVSIAPPosition()
+raises(InvalidTarget);
+
+SpecifiedPosition
+    getVSEAP(
+        in PointType
+            point_type)
+raises(InvalidTarget);
+
+SpecifiedPosition
+    getVSEAPPosition(
+        in ReferencePoint
+            reference_point)
+raises(InvalidTarget);
+
+UserControls
+    getMovingAbility()
+raises(InvalidTarget);
+
+UserControls
+    getResizingAbility()
+raises(InvalidTarget);
+
+UserControls
+    getScalingAbility()
+raises(InvalidTarget);
+
+UserControls
+    getScrollingAbility()
+raises(InvalidTarget);
+
+void
+    setSelectability(
+        in unsigned short
+            min_number_of_selections,
+        in unsigned short
+            max_number_of_selections)
+raises(InvalidTarget, InvalidParameter);
+
+void
+    setSelectionStatus(
+        in SelectionStatusValue
+            selection_state)
+raises(InvalidTarget);
+
+void
+    setSelectionPresentationEffectResponsibility(
+        in Responsibility
+            the_responsibility)
+raises(InvalidTarget);
+
+```
+
+```
+
+void
+    getSelectability(
+        out unsigned short
+            min_number_of_selections,
+        out unsigned short
+            max_number_of_selections)
+raises(InvalidTarget);
+
+EffectiveSelectability
+    getEffectiveSelectability()
+raises(InvalidTarget);
+
+SelectionStatusValue
+    getSelectionStatus()
+raises(InvalidTarget);
+
+SelectionModeValue
+    getSelectionMode()
+raises(InvalidTarget);
+
+Responsibility
+    getSelectionPresentationEffectResponsibility()
+raises(InvalidTarget);
+
+void
+    setModifiability(
+        in unsigned short
+            min_number_of_modifications,
+        in unsigned short
+            max_number_of_modifications)
+raises(InvalidTarget, InvalidParameter);
+
+void
+    setModificationStatus(
+        in ModificationStatusValue
+            modification_state)
+raises(InvalidTarget);
+
+void
+    setModificationPresentationEffectResponsibility(
+        in Responsibility
+            the_responsibility)
+raises(InvalidTarget);
+
+void
+    getModifiability(
+        out unsigned short
+            min_numbers_of_modifications,
+        out unsigned short
+            max_numbers_of_modifications)
+raises(InvalidTarget);
+
+EffectiveModifiability
+    getEffectiveModifiability()
+raises(InvalidTarget);
+
+ModificationStatusValue
+    getModificationStatus()
+raises(InvalidTarget);
+
+ModificationModeValue
+    getModificationMode()
+raises(InvalidTarget);
+
+Responsibility
+    getModificationPresentationEffectResponsibility()
+raises(InvalidTarget);
+
+void
+    setNoInteractionStyle()
+raises(InvalidTarget);
+};
+
+```
+
+### 7.1.22 RtComponent **object**
+
+For the RtComponent object no specific operations are defined. The object inherits from the RtComponentOrSocket object and from the RtObject object.
+
+#### 7.1.22.1 IDL description
+
+```
+interface RtComponent: RtComponentOrSocket, RtObject {};
+```
+
+### 7.1.23 RtCompositeOrStructuralSocket **object**
+
+The following subclause defines the operations of the RtCompositeOrStructuralSocket object.
+
+#### 7.1.23.1 setResizingStrategy **operation**
+
+##### Synopsis:
+
+|                   |                                                         |
+|-------------------|---------------------------------------------------------|
+| <b>Interface:</b> | RtCompositeOrStructuralSocket                           |
+| <b>Operation:</b> | setResizingStrategy                                     |
+| <b>Result:</b>    | void                                                    |
+| <b>In:</b>        | ResizingStrategy                      resizing_strategy |
+| <b>Exception:</b> | InvalidTarget                                           |
+
+##### Description:
+
+This operation specifies the PS resizing strategy that an rt-composite or structural socket is to have regarding the modification of the VSs of the child sockets having a Parent Relative Generic Space (PRGS).
+
+The setResizingStrategy operation triggers the execution of the 'set resizing strategy' elementary action with the bound rt-composite or structural socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 53.2.2.
+
+The resizing\_strategy parameter specifies the value of the 'resizing strategy' parameter of the 'set resizing strategy' action.
+
+The InvalidTarget exception is raised when the object instance does not represent a valid target for the normal completion of the action. The period member returns the current period of the target.
+
+#### 7.1.23.2 getResizingStrategy **operation**
+
+##### Synopsis:
+
+|                   |                               |
+|-------------------|-------------------------------|
+| <b>Interface:</b> | RtCompositeOrStructuralSocket |
+| <b>Operation:</b> | getResizingStrategy           |
+| <b>Result:</b>    | ResizingStrategy              |
+| <b>Exception:</b> | InvalidTarget                 |
+
+##### Description:
+
+This operation retrieves the resizing strategy value of the rt-composite or structural socket.
+
+The getResizingStrategy operation triggers the execution of the 'get resizing strategy' elementary action with the bound rt-composite or structural socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 53.4.3.
+
+The InvalidTarget exception is raised when the object instance does not represent a valid target for the normal completion of the action. The period member returns the current period of the target.
+
+### 7.1.23.3     `setAudibleCompositionEffect`   **operation**
+
+#### **Synopsis:**
+
+|                   |                                            |                                  |
+|-------------------|--------------------------------------------|----------------------------------|
+| <b>Interface:</b> | <code>RtCompositeOrStructuralSocket</code> |                                  |
+| <b>Operation:</b> | <code>setAudibleCompositionEffect</code>   |                                  |
+| <b>Result:</b>    | <code>void</code>                          |                                  |
+| <b>In:</b>        | <code>unsigned short</code>                | <code>audible_effect</code>      |
+| <b>In:</b>        | <code>unsigned long</code>                 | <code>transition_duration</code> |
+| <b>Exception:</b> | <code>InvalidTarget</code>                 |                                  |
+
+#### **Description:**
+
+This operation specifies the audible composition effect of an rt-composite or a structural socket. This effect is to be propagated to their descendant sockets having a PRGS. It is used to calculate the effective Original Volume (OV) of the descendant sockets having a PRGS.
+
+The `setAudibleCompositionEffect` operation triggers the execution of the 'set audible composition effect' elementary action with the bound rt-composite or structural socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 54.2.2.
+
+The `audible_effect` parameter specifies the value of the 'audible effect' parameter of the 'set audible composition effect' action.
+
+The `transition_duration` parameter specifies the value of the 'transition duration' parameter of the 'set audible composition effect' action.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The period member returns the current period of the target.
+
+### 7.1.23.4     `getAudibleCompositionEffect`   **operation**
+
+#### **Synopsis:**
+
+|                   |                                            |
+|-------------------|--------------------------------------------|
+| <b>Interface:</b> | <code>RtCompositeOrStructuralSocket</code> |
+| <b>Operation:</b> | <code>getAudibleCompositionEffect</code>   |
+| <b>Result:</b>    | <code>unsigned short</code>                |
+| <b>Exception:</b> | <code>InvalidTarget</code>                 |
+
+#### **Description:**
+
+This operation retrieves the audible composition effect value of the rt-composite or structural socket. This effect is expressed as a percentage and used to determine the effective OV of the child sockets of the rt-composite or structural socket having as PRGS the rt-composite or structural socket. This effect is recursive for the child sockets of the structural sockets having as PRGS the rt-composite or structural socket, and so on.
+
+The `getAudibleCompositionEffect` operation triggers the execution of the 'get audible composition effect' elementary action with the bound rt-composite or structural socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 54.3.3.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The period member returns the current period of the target.
+
+### 7.1.23.5     `getNumberOfSelectedSockets`   **operation**
+
+#### **Synopsis:**
+
+|                   |                                            |
+|-------------------|--------------------------------------------|
+| <b>Interface:</b> | <code>RtCompositeOrStructuralSocket</code> |
+| <b>Operation:</b> | <code>getNumberOfSelectedSockets</code>    |
+| <b>Result:</b>    | <code>unsigned short</code>                |
+| <b>Exception:</b> | <code>InvalidTarget</code>                 |
+
+#### **Description:**
+
+This operation retrieves the 'number of selected sockets' attribute value of the rt-composite or structural socket.
+
+The `getNumberOfSelectedSockets` operation triggers the execution of the 'get number of selected sockets' elementary action with the bound rt-composite or structural socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 57.3.5.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+#### 7.1.23.6 `getNumberOfModifiedSockets` operation
+
+##### Synopsis:
+
+**Interface:** `RtCompositeOrStructuralSocket`  
+**Operation:** `getNumberOfModifiedSockets`  
+**Result:** `unsigned short`  
+**Exception:** `InvalidTarget`
+
+##### Description:
+
+This operation retrieves the 'number of modified sockets' attribute value of the rt-composite or structural socket.
+
+The `getNumberOfModifiedSockets` operation triggers the execution of the 'get number of modified sockets' elementary action with the bound rt-composite or structural socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 58.3.5.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+#### 7.1.23.7 `setMenuInteractionStyle` operation
+
+##### Synopsis:
+
+**Interface:** `RtCompositeOrStructuralSocket`  
+**Operation:** `setMenuInteractionStyle`  
+**Result:** `void`  
+**In:** `Orientation` `upper_menu_orientation`  
+**In:** `sequence <Association>` `list_of_associations`  
+**Exception:** `InvalidTarget`  
+**Exception:** `InvalidParameter`
+
+##### Description:
+
+This operation assigns the menu interaction style to an rt-composite or a structural socket. This operation defines a style which affects the complete rt-composite or structural socket, i.e all generations.
+
+The `setMenuInteractionStyle` operation triggers the execution of the 'set menu style' elementary action with the bound rt-composite or structural socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 59.2.4.
+
+The `upper_menu_orientation` parameter specifies the value of the 'upper menu orientation' parameter of the 'set menu style' action.
+
+The `list_of_associations` parameter specifies the value of the 'list of associations' parameter of the 'set menu style' action.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+The `InvalidParameter` exception is raised when the value of one of the parameters prohibits the normal execution of the action. The `completion_status` member indicates whether the action was completed (with a default value assigned to the inadequate parameter) or not. The `parameter_number` member identifies the rank of the invalid parameter.
+
+### 7.1.23.8 setScrollingListInteractionStyle operation
+
+#### Synopsis:
+
+|                   |                                  |                      |
+|-------------------|----------------------------------|----------------------|
+| <b>Interface:</b> | RtCompositeOrStructuralSocket    |                      |
+| <b>Operation:</b> | setScrollingListInteractionStyle |                      |
+| <b>Result:</b>    | void                             |                      |
+| <b>In:</b>        | PerceptibleReference             | background           |
+| <b>In:</b>        | unsigned short                   | visible_items_number |
+| <b>In:</b>        | SocketTail                       | first_item           |
+| <b>In:</b>        | Separator                        | the_separator        |
+| <b>In:</b>        | Orientation                      | the_orientation      |
+| <b>In:</b>        | SliderSide                       | slider_side          |
+| <b>In:</b>        | PerceptibleReference             | slider               |
+| <b>In:</b>        | PerceptibleReference             | slider_cursor        |
+| <b>In:</b>        | PerceptibleReference             | slider_background    |
+| <b>In:</b>        | long                             | slider_min_value     |
+| <b>In:</b>        | long                             | slider_max_value     |
+| <b>Exception:</b> | InvalidTarget                    |                      |
+| <b>Exception:</b> | InvalidParameter                 |                      |
+
+#### Description:
+
+This operation assigns the scrolling list interaction style to an rt-composite or a structural socket. This operation defines a style which affects the first generation and only the child presentable sockets of the rt-composite or structural socket.
+
+The `setScrollingListInteractionStyle` operation triggers the execution of the 'set scrolling list style' elementary action with the bound rt-composite or structural socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 59.2.5.
+
+The `background` parameter specifies the value of the 'background' parameter of the 'set scrolling list style' action.
+
+The `visible_items_number` parameter specifies the value of the 'number of visible items' parameter of the 'set scrolling list style' action.
+
+The `first_item` parameter specifies the value of the 'first item' parameter of the 'set scrolling list style' action.
+
+The `the_separator` parameter specifies the value of the 'separator' parameter of the 'set scrolling list style' action.
+
+The `the_orientation` parameter specifies the value of the 'scrolling list orientation' parameter of the 'set scrolling list style' action.
+
+The `slider_side` parameter specifies the value of the 'slider side' parameter of the 'set scrolling list style' action.
+
+The `slider`, `slider_cursor`, `slider_background`, `slider_min_value`, `slider_max_value` parameters specify the values of the parameters of the 'set slider style' action embedded by the 'set scrolling list style' action.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+The `InvalidParameter` exception is raised when the value of one of the parameters prohibits the normal execution of the action. The `completion_status` member indicates whether the action was completed (with a default value assigned to the inadequate parameter) or not. The `parameter_number` member identifies the rank of the invalid parameter.
+
+### 7.1.23.9 IDL description
+
+```
+interface RtCompositeOrStructuralSocket {
+
+    void
+        setResizingStrategy(
+            in ResizingStrategy
+                resizing_strategy)
+        raises(InvalidTarget);
+
+    ResizingStrategy
+        getResizingStrategy()
+        raises(InvalidTarget);
+
+    void
+        setAudibleCompositionEffect(
+            in unsigned short
+                audible_effect,
+            in unsigned long
+                transition_duration)
+        raises(InvalidTarget);
+
+    unsigned short
+        getAudibleCompositionEffect()
+        raises(InvalidTarget);
+
+    unsigned short
+        getNumberOfSelectedSockets()
+        raises(InvalidTarget);
+
+    unsigned short
+        getNumberOfModifiedSockets()
+        raises(InvalidTarget);
+
+    void
+        setMenuInteractionStyle(
+            in Orientation
+                upper_menu_orientation,
+            in sequence <Association>
+                list_of_associations)
+        raises(InvalidTarget, InvalidParameter);
+
+    void
+        setScrollingListInteractionStyle(
+            in PerceptibleReference
+                background,
+            in unsigned short
+                visible_items_number,
+            in SocketTail
+                first_item,
+            in Separator
+                the_separator,
+            in Orientation
+                the_orientation,
+            in SliderSide
+                slider_side,
+            in PerceptibleReference
+                slider,
+            in PerceptibleReference
+                slider_cursor,
+            in PerceptibleReference
+                slider_background,
+            in long
+                slider_min_value,
+            in long
+                slider_max_value)
+        raises(InvalidTarget, InvalidParameter);
+
+};
+```
+
+### 7.1.24 RtComposite object
+
+For the `RtComposite` object no specific operations are defined. The object inherits from the `RtCompositeOrStructuralSocket` object and from the `RtComponent` object.
+
+#### 7.1.24.1 IDL description
+
+```
+interface RtComposite: RtCompositeOrStructuralSocket, RtComponent {};
+```
+
+#### 7.1.25 StructuralSocket object
+
+For the `StructuralSocket` object no specific operations are defined. The object inherits from the `RtCompositeOrStructuralSocket` object and from the `Socket` object.
+
+#### 7.1.25.1 IDL description
+
+```
+interface StructuralSocket: RtCompositeOrStructuralSocket, Socket {};
+```
+
+#### 7.1.26 RtGenericContentOrPresentableSocket object
+
+The following subclause defines the operations of the `RtGenericContentOrPresentableSocket` object.
+
+##### 7.1.26.1 `setAudibleVolume` operation
+
+###### Synopsis:
+
+|                   |                                                                                                |
+|-------------------|------------------------------------------------------------------------------------------------|
+| <b>Interface:</b> | <code>RtGenericContentOrPresentableSocket</code>                                               |
+| <b>Operation:</b> | <code>setAudibleVolume</code>                                                                  |
+| <b>Result:</b>    | <code>void</code>                                                                              |
+| <b>In:</b>        | <code>AudibleVolume</code> <span style="float: right;"><code>audible_volume</code></span>      |
+| <b>In:</b>        | <code>unsigned long</code> <span style="float: right;"><code>transition_duration</code></span> |
+| <b>Exception:</b> | <code>InvalidTarget</code>                                                                     |
+| <b>Exception:</b> | <code>InvalidParameter</code>                                                                  |
+
+###### Description:
+
+This action specifies the audible volume of an rt-content, an rt-multiplexed content, a presentable socket or a multiplexed presentable socket.
+
+The `setAudibleVolume` operation triggers the execution of the 'set audible volume' elementary action with the bound rt-content, rt-multiplexed content, presentable socket or multiplexed presentable socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 54.2.1.
+
+The `audible_volume` parameter specifies the value of the 'audible volume' parameter of the 'set audible volume' action.
+
+The `transition_duration` parameter specifies the value of the 'transition duration' parameter of the 'set audible volume' action.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+The `InvalidParameter` exception is raised when the value of one of the parameters prohibits the normal execution of the action. The `completion_status` member indicates whether the action was completed (with a default value assigned to the inadequate parameter) or not. The `parameter_number` member identifies the rank of the invalid parameter.
+
+##### 7.1.26.2 `getInitialOriginalAudibleVolume` operation
+
+###### Synopsis:
+
+|                   |                                                  |
+|-------------------|--------------------------------------------------|
+| <b>Interface:</b> | <code>RtGenericContentOrPresentableSocket</code> |
+| <b>Operation:</b> | <code>getInitialOriginalAudibleVolume</code>     |
+| <b>Result:</b>    | <code>unsigned long</code>                       |
+| <b>Exception:</b> | <code>InvalidTarget</code>                       |
+
+###### Description:
+
+This operation retrieves the initial original audible volume value of the rt-content, rt-multiplexed content, presentable socket or multiplexed presentable socket. This initial volume is expressed in original generic audible volume unit within the interval defined by the original audible volume range.
+
+The `getInitialOriginalAudibleVolume` operation triggers the execution of the 'get IOV' elementary action with the bound `rt-content`, `rt-multiplexed content`, `presentable socket` or `multiplexed presentable socket` as its single target.
+
+The effect of the action on its target, the semantics of its parameters, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 54.3.1.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+#### 7.1.26.3 `getCurrentOriginalAudibleVolume` operation
+
+##### Synopsis:
+
+**Interface:** `RtGenericContentOrPresentableSocket`  
+**Operation:** `getCurrentOriginalAudibleVolume`  
+**Result:** `unsigned long`  
+**Exception:** `InvalidTarget`
+
+##### Description:
+
+This operation retrieves the current original audible volume value of the `rt-content`, `rt-multiplexed content`, `presentable socket` or `multiplexed presentable socket`. This current volume is expressed in original generic audible volume unit within the interval defined by the original audible volume range.
+
+The `getCurrentOriginalAudibleVolume` operation triggers the execution of the 'get current OV' elementary action with the bound `rt-content`, `rt-multiplexed content`, `presentable socket` or `multiplexed presentable socket` as its single target.
+
+The effect of the action on its target, the semantics of its parameters, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 54.3.2.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+#### 7.1.26.4 `getEffectiveOriginalAudibleVolume` operation
+
+##### Synopsis:
+
+**Interface:** `RtGenericContentOrPresentableSocket`  
+**Operation:** `getEffectiveOriginalAudibleVolume`  
+**Result:** `unsigned long`  
+**Exception:** `InvalidTarget`
+
+##### Description:
+
+This operation retrieves the effective original audible volume value of the `rt-content`, `rt-multiplexed content`, `presentable socket` or `multiplexed presentable socket`. This effective volume is expressed in original generic audible volume unit within the interval defined by the original audible volume range. It is calculated by the MHEG engine using the current original audible volume and the audible composition effect.
+
+The `getEffectiveOriginalAudibleVolume` operation triggers the execution of the 'get effective OV' elementary action with the bound `rt-content`, `rt-multiplexed content`, `presentable socket` or `multiplexed presentable socket` as its single target.
+
+The effect of the action on its target, the semantics of its parameters, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 54.3.4.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+#### 7.1.26.5 `getPerceptibleAudibleVolume` operation
+
+##### Synopsis:
+
+**Interface:** `RtGenericContentOrPresentableSocket`  
+**Operation:** `getPerceptibleAudibleVolume`  
+**Result:** `unsigned long`  
+**Exception:** `InvalidTarget`
+
+## Description:
+
+This operation retrieves the perceptible original audible volume value of the rt-content, rt-multiplexed content, presentable socket or multiplexed presentable socket in the assigned channel. This perceptible volume is expressed in channel generic audible volume unit within the interval defined by the channel audible volume range. It is calculated by the MHEG engine and corresponds to a projection of the effective original audible volume in the channel generic space.
+
+The `getPerceptibleAudibleVolume` operation triggers the execution of the 'get perceptible OV' elementary action with the bound rt-content, rt-multiplexed content, presentable socket or multiplexed presentable socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 54.3.5.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+### 7.1.26.6 `setButtonInteractionStyle` operation
+
+#### Synopsis:
+
+|                   |                                     |                          |
+|-------------------|-------------------------------------|--------------------------|
+| <b>Interface:</b> | RtGenericContentOrPresentableSocket |                          |
+| <b>Operation:</b> | setButtonInteractionStyle           |                          |
+| <b>Result:</b>    | void                                |                          |
+| <b>In:</b>        | PresentationState                   | initial_state            |
+| <b>In:</b>        | AlternatePresentation               | alternate_presentation_1 |
+| <b>In:</b>        | AlternatePresentation               | alternate_presentation_2 |
+| <b>In:</b>        | AlternatePresentation               | alternate_presentation_3 |
+| <b>Exception:</b> | InvalidTarget                       |                          |
+| <b>Exception:</b> | InvalidParameter                    |                          |
+
+#### Description:
+
+This operation assigns the button interaction style to an rt-content, rt-multiplexed content, a presentable socket or a multiplexed presentable socket.
+
+The `setButtonInteractionStyle` operation triggers the execution of the 'set button style' elementary action with the bound rt-content, rt-multiplexed content, presentable socket or multiplexed presentable socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 59.2.1.
+
+The `initial_state` parameter specifies the value of the 'initial state' parameter of the 'set button style' action.
+
+The `alternate_presentation_1` parameter specifies the value of the 'alternate presentation 1' parameter of the 'set button style' action.
+
+The `alternate_presentation_2` parameter specifies the value of the 'alternate presentation 2' parameter of the 'set button style' action.
+
+The `alternate_presentation_3` parameter specifies the value of the 'alternate presentation 3' parameter of the 'set button interaction style' action.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+The `InvalidParameter` exception is raised when the value of one of the parameters prohibits the normal execution of the action. The `completion_status` member indicates whether the action was completed (with a default value assigned to the inadequate parameter) or not. The `parameter_number` member identifies the rank of the invalid parameter.
+
+### 7.1.26.7 IDL description
+
+```
+interface RtGenericContentOrPresentableSocket {
+
+    void
+        setAudibleVolume(
+            in AudibleVolume
+                audible_volume,
+            in unsigned long
+                transition_duration)
+        raises(InvalidTarget, InvalidParameter);
+
+    unsigned long
+        getInitialOriginalAudibleVolume()
+        raises(InvalidTarget);
+
+    unsigned long
+        getCurrentOriginalAudibleVolume()
+        raises(InvalidTarget);
+
+    unsigned long
+        getEffectiveOriginalAudibleVolume()
+        raises(InvalidTarget);
+
+    unsigned long
+        getPerceptibleAudibleVolume()
+        raises(InvalidTarget);
+
+    void
+        setButtonInteractionStyle(
+            in PresentationState
+                initial_state,
+            in AlternatePresentation
+                alternate_presentation_1,
+            in AlternatePresentation
+                alternate_presentation_2,
+            in AlternatePresentation
+                alternate_presentation_3)
+        raises(InvalidTarget, InvalidParameter);
+
+};
+```
+
+### 7.1.27 RtGenericContent object
+
+For the `RtGenericContent` object no specific operations are defined. The object inherits from the `RtGenericContentOrPresentableSocket` object and from the `RtComponent` object.
+
+#### 7.1.27.1 IDL description
+
+```
+interface RtGenericContent: RtGenericContentOrPresentableSocket, RtComponent {};
+```
+
+### 7.1.28 GenericPresentableSocket object
+
+For the `GenericPresentableSocket` object no specific operations are defined. The object inherits from the `RtGenericContentOrPresentableSocket` object and from the `Socket` object.
+
+#### 7.1.28.1 IDL description
+
+```
+interface GenericPresentableSocket: RtGenericContentOrPresentableSocket, Socket
+{};
+```
+
+### 7.1.29 RtContentOrPresentableSocket object
+
+The following subclause defines the operations of the `RtContentOrPresentableSocket` object.
+
+### 7.1.29.1 setSliderInteractionStyle operation
+
+#### Synopsis:
+
+|                   |                              |                 |
+|-------------------|------------------------------|-----------------|
+| <b>Interface:</b> | RtContentOrPresentableSocket |                 |
+| <b>Operation:</b> | setSliderInteractionStyle    |                 |
+| <b>Result:</b>    | void                         |                 |
+| <b>In:</b>        | PerceptibleReference         | cursor          |
+| <b>In:</b>        | PerceptibleReference         | background      |
+| <b>In:</b>        | Orientation                  | the_orientation |
+| <b>In:</b>        | short                        | min_value       |
+| <b>In:</b>        | short                        | max_value       |
+| <b>Exception:</b> | InvalidTarget                |                 |
+| <b>Exception:</b> | InvalidParameter             |                 |
+
+#### Description:
+
+This operation assigns the slider interaction style to an rt-content or a presentable socket created from a content object model which contains a generic numeric as 'content data'.
+
+The `setSliderStyle` operation triggers the execution of the 'set slider style' elementary action with the bound rt-content or presentable socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 59.2.2.
+
+The `cursor` parameter specifies the value of the 'cursor' parameter of the 'set slider style' action.
+
+The `background` parameter specifies the value of the 'background' parameter of the 'set slider style' action.
+
+The `the_orientation` parameter specifies the value of the 'orientation' parameter of the 'set slider style' action.
+
+The `min_value` parameter specifies the value of the 'minimum value' parameter of the 'set slider style' action.
+
+The `max_value` parameter specifies the value of the 'maximum value' parameter of the 'set slider style' action.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+The `InvalidParameter` exception is raised when the value of one of the parameters prohibits the normal execution of the action. The `completion_status` member indicates whether the action was completed (with a default value assigned to the inadequate parameter) or not. The `parameter_number` member identifies the rank of the invalid parameter.
+
+### 7.1.29.2 setEntryFieldInteractionStyle operation
+
+#### Synopsis:
+
+|                   |                               |            |
+|-------------------|-------------------------------|------------|
+| <b>Interface:</b> | RtContentOrPresentableSocket  |            |
+| <b>Operation:</b> | setEntryFieldInteractionStyle |            |
+| <b>Result:</b>    | void                          |            |
+| <b>In:</b>        | EchoStyle                     | echo_style |
+| <b>In:</b>        | PerceptibleReference          | background |
+| <b>Exception:</b> | InvalidTarget                 |            |
+| <b>Exception:</b> | InvalidParameter              |            |
+
+#### Description:
+
+This operation assigns the entry field interaction style to an rt-content or a presentable socket created from a content object model which contains a generic numeric or a generic string as 'content data'.
+
+The `setEntryFieldInteractionStyle` operation triggers the execution of the 'set entry field style' elementary action with the bound rt-content or presentable socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 59.2.3.
+
+The `echo_style` parameter specifies the value of the 'echo style' parameter of the 'set entry field style' action.
+
+The `background` parameter specifies the value of the 'background' parameter of the 'set entry field style' action.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+The `InvalidParameter` exception is raised when the value of one of the parameters prohibits the normal execution of the action. The `completion_status` member indicates whether the action was completed (with a default value assigned to the inadequate parameter) or not. The `parameter_number` member identifies the rank of the invalid parameter.
+
+### 7.1.29.3 IDL description
+
+```
+interface RtContentOrPresentableSocket
+{
+    void
+        setSliderInteractionStyle(
+            in PerceptibleReference
+                cursor,
+            in PerceptibleReference
+                background,
+            in Orientation
+                the_orientation,
+            in short
+                min_value,
+            in short
+                max_value)
+        raises(InvalidTarget, InvalidParameter);
+    void
+        setEntryFieldInteractionStyle(
+            in EchoStyle
+                echo_style,
+            in PerceptibleReference
+                background)
+        raises(InvalidTarget, InvalidParameter);
+};
+```
+
+### 7.1.30 RtContent object
+
+For the `RtContent` object no specific operations are defined. The object inherits from the `RtContentOrPresentableSocket` object and from the `RtGenericContent` object.
+
+#### 7.1.30.1 IDL description
+
+```
+interface RtContent: RtContentOrPresentableSocket, RtGenericContent {};
+```
+
+### 7.1.31 PresentableSocket object
+
+For the `PresentableSocket` object no specific operations are defined. The object inherits from the `RtContentOrPresentableSocket` object and from the `GenericPresentableSocket` object.
+
+#### 7.1.31.1 IDL description
+
+```
+interface PresentableSocket: RtContentOrPresentableSocket,
+GenericPresentableSocket {};
+```
+
+### 7.1.32 RtMultiplexedContentOrPresentableSocket object
+
+The following subclause defines the operations of the `RtMultiplexedContentOrPresentableSocket` object.
+
+### 7.1.32.1 `setStreamChoice` operation
+
+#### Synopsis:
+
+**Interface:** `RtMultiplexedContentOrPresentableSocket`  
+**Operation:** `setStreamChoice`  
+**Result:** `void`  
+**In:** `StreamIdentifier` `stream_identifier`  
+**Exception:** `InvalidTarget`  
+**Exception:** `InvalidParameter`
+
+#### Description:
+
+This operation specifies a stream to be chosen in the multiplexed data and assigned to the rt-multiplexed content or multiplexed presentable socket. Once a stream is chosen for an rt-multiplexed content or a multiplexed presentable socket, when it becomes running, the rt-multiplexed content or the multiplexed presentable socket is responsible for the presentation of this chosen stream.
+
+The `setStreamChoice` operation triggers the execution of the 'set stream choice' elementary action with the bound rt-multiplexed content or multiplexed presentable socket as its single target.
+
+The `stream_identifier` parameter specifies the value of the 'stream choice' parameter of the 'set stream choice' action.
+
+The effect of the action on its target, the semantics of its parameters and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 55.2.1.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+The `InvalidParameter` exception is raised when the value of one of the parameters prohibits the normal execution of the action. The `completion_status` member indicates whether the action was completed (with a default value assigned to the inadequate parameter) or not. The `parameter_number` member identifies the rank of the invalid parameter.
+
+### 7.1.32.2 `getStreamChosen` operation
+
+#### Synopsis:
+
+**Interface:** `RtMultiplexedContentOrPresentableSocket`  
+**Operation:** `getStreamChosen`  
+**Result:** `StreamValue`  
+**Exception:** `InvalidTarget`
+
+#### Description:
+
+This operation retrieves the stream chosen for the rt-multiplexed content or multiplexed presentable socket.
+
+The `getStreamChosen` operation triggers the execution of the 'get stream chosen' elementary action with the bound rt-multiplexed content or multiplexed presentable socket as its single target.
+
+The effect of the action on its target, the semantics of its parameters, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 55.3.1.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+### 7.1.32.3 IDL description
+
+```
+interface RtMultiplexedContentOrPresentableSocket {
+    void
+        setStreamChoice (
+            in StreamIdentifier
+                stream_identifier)
+        raises (InvalidTarget, InvalidParameter);
+    StreamValue
+        getStreamChosen ()
+        raises (InvalidTarget);
+};
+```
+
+### 7.1.33 RtMultiplexedContent object
+
+For the RtMultiplexedContent object no specific operations are defined. The object inherits from the RtMultiplexedContentOrPresentableSocket object and from the RtGenericContent object.
+
+#### 7.1.33.1 IDL description
+
+```
+interface RtMultiplexedContent: RtMultiplexedContentOrPresentableSocket,
+RtGenericContent {};
+```
+
+### 7.1.34 MultiplexedPresentableSocket object
+
+For the MultiplexedPresentableSocket object no specific operations are defined. The object inherits from the RtMultiplexedContentOrPresentableSocket object and from the GenericPresentableSocket object.
+
+#### 7.1.34.1 IDL description
+
+```
+interface MultiplexedPresentableSocket: RtMultiplexedContentOrPresentableSocket,
+GenericPresentableSocket {};
+```
+
+### 7.1.35 Channel object
+
+The following subclause defines the operations of the Channel object. The object inherits from the Entity object.
+
+#### 7.1.35.1 bind operation
+
+##### Synopsis:
+
+|                   |                   |                   |
+|-------------------|-------------------|-------------------|
+| <b>Interface:</b> | Channel           |                   |
+| <b>Operation:</b> | bind              |                   |
+| <b>Result:</b>    | ChannelIdentifier |                   |
+| <b>In:</b>        | ChannelReference  | channel_reference |
+| <b>Exception:</b> | AlreadyBound      |                   |
+| <b>Exception:</b> | InvalidTarget     |                   |
+
+##### Description:
+
+This operation binds the Channel instance (an interface object instance) with a channel (an MHEG entity).
+
+The channel\_reference parameter specifies the reference of the channel.
+
+The operation returns the identifier of the bound channel.
+
+The AlreadyBound exception is raised when the interface object instance is already bound with an MHEG entity.
+
+The InvalidTarget exception is raised when the targeted MHEG entity is not available. The period member returns the current period of the target.
+
+#### 7.1.35.2 unbind operation
+
+##### Synopsis:
+
+|                   |          |
+|-------------------|----------|
+| <b>Interface:</b> | Channel  |
+| <b>Operation:</b> | unbind   |
+| <b>Result:</b>    | void     |
+| <b>Exception:</b> | NotBound |
+
+##### Description:
+
+This operation cancels the binding between the Channel instance (an interface object instance) and a channel (an MHEG entity).
+
+The NotBound exception is raised when the interface object instance is not bound with an MHEG entity.
+
+### 7.1.35.3      new operation
+
+#### Synopsis:
+
+|                   |                        |                                 |
+|-------------------|------------------------|---------------------------------|
+| <b>Interface:</b> | Channel                |                                 |
+| <b>Operation:</b> | new                    |                                 |
+| <b>Result:</b>    | ChannelIdentifier      |                                 |
+| <b>In:</b>        | ChannelReference       | channel_reference               |
+| <b>In:</b>        | OriginalDefDeclaration | original_definition_declaration |
+| <b>Exception:</b> | AlreadyBound           |                                 |
+| <b>Exception:</b> | InvalidTarget          |                                 |
+
+#### Description:
+
+This operation enables the creation of a channel by the MHEG engine.
+
+The `new` operation triggers the execution of the 'new channel' elementary action targeted at a single channel.
+
+The effect of the action on its target, the semantics of its parameters and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 61.2.1.
+
+The `channel_reference` parameter specifies a reference to a channel.
+
+The `original_definition_declaration` parameter specifies the value of the 'original definition declaration' parameter of the 'new channel' action.
+
+This operation implicitly binds the Channel instance (an interface object instance) with the new created channel (an MHEG entity).
+
+The operation returns the identifier of the new created channel bound with the Channel instance.
+
+The `AlreadyBound` exception is raised when the interface object instance is already bound with an MHEG entity.
+
+The `InvalidTarget` exception is raised when the targeted MHEG entity is not available. The `period` member returns the current period of the target.
+
+### 7.1.35.4      delete operation
+
+#### Synopsis:
+
+|                   |               |
+|-------------------|---------------|
+| <b>Interface:</b> | Channel       |
+| <b>Operation:</b> | delete        |
+| <b>Result:</b>    | void          |
+| <b>Exception:</b> | NotBound      |
+| <b>Exception:</b> | InvalidTarget |
+
+#### Description:
+
+This operation enables the removing of a channel by the MHEG engine.
+
+The `delete` operation triggers the execution of the 'delete channel' elementary action targeted at a single channel.
+
+The effect of the action on its target and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 61.2.2.
+
+This operation implicitly cancels the binding between the Channel instance (an interface object instance) and the new deleted channel (an MHEG entity).
+
+The `NotBound` exception is raised when the interface object instance is not bound with an MHEG entity.
+
+The `InvalidTarget` exception is raised when the targeted MHEG entity is not available. The `period` member returns the current period of the target.
+
+#### 7.1.35.5     getRtAvailabilityStatus **operation**
+
+##### **Synopsis:**
+
+**Interface:**         Channel  
+**Operation:**        getAvailability  
+**Result:**            ChannelStatusValue  
+**Exception:**        NotBound  
+**Exception:**        InvalidTarget
+
+##### **Description:**
+
+This operation retrieves the availability of a channel to the MHEG engine.
+
+The `getAvailability` operation triggers the execution of the 'get channel availability status' elementary action with the bound channel as its single target.
+
+The effect of the action on its target, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 61.3.1.
+
+The operation returns the availability of the channel bound with the Channel instance. The returned value is either `NOT_AVAILABLE`, `PROCESSING` or `AVAILABLE`.
+
+When the returned value is `NOT_AVAILABLE`, the operation implicitly cancels the binding between the Channel instance (an interface object instance) and the channel (an MHEG entity).
+
+The `NotBound` exception is raised when the interface object instance is not bound with an MHEG entity.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+#### 7.1.35.6     getIdentifier **operation**
+
+##### **Synopsis:**
+
+**Interface:**         Channel  
+**Operation:**        getIdentifier  
+**Result:**            ChannelIdentifier  
+**Exception:**        NotBound
+
+##### **Description:**
+
+This operation retrieves the identifier of the channel (an MHEG entity) bound with the Channel instance (an interface object instance).
+
+The `NotBound` exception is raised when the interface object instance is not bound with an MHEG entity.
+
+#### 7.1.35.7     kill **operation**
+
+##### **Synopsis:**
+
+**Interface:**         Channel  
+**Operation:**        kill  
+**Result:**            void
+
+##### **Description:**
+
+This operation deletes the Channel instance (an interface object instance).
+
+#### 7.1.35.8     setPerceptability **operation**
+
+##### **Synopsis:**
+
+**Interface:**         Channel  
+**Operation:**        setPerceptability  
+**Result:**            void  
+**In:**                ChannelPerceptabilityValue             channel\_perceptability  
+**Exception:**        InvalidTarget
+
+**Description:**
+
+This operation enables to turn on or off a channel. This is used to enable or disable the perception of a channel by a user.
+
+The `setPerceptability` operation triggers the execution of the 'set channel perceptability' elementary action with the bound channel as its single target.
+
+The effect of the action on its target, the semantics of its parameters and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 62.2.1.
+
+The `channel_perceptability` parameter specifies the value of the 'perceptability' parameter of the 'set channel perceptability' action.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+**7.1.35.9      `getPerceptability` operation****Synopsis:**
+
+**Interface:**            `Channel`  
+**Operation:**          `getPerceptability`  
+**Result:**             `ChannelPerceptabilityValue`  
+**Exception:**          `InvalidTarget`
+
+**Description:**
+
+This operation retrieves the perceptability of a channel.
+
+The `getPerceptability` operation triggers the execution of the 'get channel perceptability' elementary action with the bound channel as its single target.
+
+The effect of the action on its target, the computation of its result and the error conditions that cause exceptions to be raised are defined by the MHEG standard, 62.3.1.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+**7.1.35.10    `getAssignedPerceptibles` operation****Synopsis:**
+
+**Interface:**            `Channel`  
+**Operation:**          `getAssignedPerceptibles`  
+**Result:**             `sequence<PerceptibleReference>`  
+**Exception:**          `InvalidTarget`
+
+**Description:**
+
+This operation retrieves the perceptibles assigned to the channel.
+
+The `getAssignedPerceptibles` operation has no corresponding MHEG elementary action. It is symmetrical to the 'get RGS' elementary action which retrieves the channel assigned to a perceptible.
+
+The `InvalidTarget` exception is raised when the object instance does not represent a valid target for the normal completion of the action. The `period` member returns the current period of the target.
+
+**7.1.35.11    IDL description**
+
+```
+interface Channel: Entity {
+    ChannelIdentifier
+    bind(
+        in ChannelReference
+        channel_reference)
+    raises (AlreadyBound, InvalidTarget);
+    void
+    unbind()
+    raises (NotBound);
+```
+
+```
+
+ChannelIdentifier
+    new(
+        in ChannelReference
+            channel_reference,
+        in OriginalDefDeclaration
+            original_definition_declaration)
+raises(AlreadyBound, InvalidTarget);
+
+void
+    delete()
+raises(NotBound, InvalidTarget);
+
+ChannelStatusValue
+    getAvailability()
+raises(NotBound, InvalidTarget);
+
+ChannelIdentifier
+    getIdentifier()
+raises(NotBound);
+
+void
+    kill();
+
+void
+    setPerceptability(
+        in ChannelPerceptabilityValue
+            channel_perceptability)
+raises(InvalidTarget);
+
+ChannelPerceptabilityValue
+    getPerceptability()
+raises(InvalidTarget);
+
+sequence<PerceptibleReference>
+    getAssignedPerceptibles()
+raises(InvalidTarget);
+};
+
+```
+
+### 7.1.36 Parameter definition
+
+The following subclause defines the parameters that are used by the mandatory primitives.
+
+```
+
+//=====
+typedef sequence<long> ApplicationIdentifier;
+
+// Corresponding MHEG datatype: Object-Number
+//=====
+typedef long ObjectNumber;
+
+// Interface: MhObject Operation: bind
+// Interface: MhObject Operation: prepare
+// Interface: MhObject Operation: getIdentifier
+// Corresponding MHEG datatype: MHEG-Identifier
+//=====
+struct MHEGIdentifier {
+    sequence<ApplicationIdentifier,1>
+        application_identifier;
+    ObjectNumber
+        object_number;
+};
+
+// Corresponding MHEG datatype: Public-Identifier
+//=====
+typedef string PublicIdentifier;
+
+// Corresponding MHEG datatype: System-Identifier
+//=====
+typedef string SystemIdentifier;
+
+```
+
+```
+
+// Corresponding MHEG datatype: External-Long-Identifier
+//=====
+struct ExternalLongIdentifier {
+    PublicIdentifier
+        public_identifier;
+    SystemIdentifier
+        system_identifier;
+};
+
+// Corresponding MHEG datatype: Alias
+//=====
+typedef string Alias;
+
+// Corresponding MHEG datatype: Container-Child-Reference
+//=====
+enum ContainerChildReference {
+    CHILD,
+    DESCENDANT
+};
+
+// Interface: MhObject Operation: getPreparationStatus
+// Corresponding MHEG datatype: Preparation-Status-Value
+//=====
+enum PreparationStatusValue {
+    READY,
+    NOT_READY,
+    PROCESSING
+};
+
+// Interface: MhMultiplexedContent Operation: setMultiplex
+// Interface: MhMultiplexedContent Operation: setDemultiplex
+// Interface: RtMultiplexedContentOrPresentableSocket Operation: setStreamChoice
+// Corresponding MHEG datatype: Stream-Identifier
+//=====
+typedef sequence<long> StreamIdentifier;
+
+// Corresponding MHEG datatype: Rt-Dynamic-Reference
+//=====
+enum RtDynamicReference {
+    QUESTION_MARK,
+    STAR
+};
+
+// Interface: RtObject Operation: getAvailabilityStatus
+// Corresponding MHEG datatype: Rt-Availibility-Status-Value
+//=====
+enum RtAvailabilityStatusValue {
+    RT_AVAILIBILITY_STATUS_VALUE_AVAILABLE,
+    RT_AVAILIBILITY_STATUS_VALUE_NOT_AVAILABLE,
+    RT_AVAILIBILITY_STATUS_VALUE_PROCESSING
+};
+
+// Interface: RtObject Operation: getRunningStatus
+// Corresponding MHEG datatype: Running-Status-Value
+//=====
+enum RunningStatusValue {
+    RUNNING_STATUS_VALUE_RUNNING,
+    RUNNING_STATUS_VALUE_NOT_RUNNING,
+    RUNNING_STATUS_VALUE_PROCESSING
+};
+
+// Interface: RtScript Operation: getTerminationStatus
+// Corresponding MHEG datatype: Termination-Status-Value
+//=====
+enum TerminationStatusValue {
+    TERMINATED,
+    NOT_TERMINATED
+};
+
+// Interface: RtComponentOrSocket Operation: setRGS
+// Interface: Channel Operation: getIdentifier
+// Corresponding MHEG datatype: Channel-Identifier
+//=====
+typedef long ChannelIdentifier;
+
+```
+
+```
+
+// Corresponding MHEG datatype: Priority-Level
+//=====
+enum PriorityLevel {
+    INCREMENT_PRIORITY,
+    DECREMENT_PRIORITY
+};
+
+// Interface: RtComponentOrSocket Operation: setVisibleDuration
+// Corresponding MHEG datatype: Temporal-Position
+//=====
+enum TemporalPositionTag { SPECIFIED_TEMPORAL_POINT_TAG,
+LOGICAL_TEMPORAL_PD_POINT_TAG };
+union TemporalPosition
+switch (TemporalPositionTag){
+    case SPECIFIED_TEMPORAL_POINT_TAG:
+        long
+            specified_temporal_point;
+    case LOGICAL_TEMPORAL_PD_POINT_TAG:
+        long
+            logical_temporal_PD_point;
+};
+
+// Interface: RtComponentOrSocket Operation: setCurrentTemporalPosition
+// Corresponding MHEG datatype: Current-Temporal-Position
+//=====
+enum CurrentTemporalPositionTag {
+CURRENT_TEMPORAL_POSITION_SPECIFIED_TEMPORAL_POINT_TAG,
+CURRENT_TEMPORAL_POSITION_LOGICAL_TEMPORAL_VD_POINT_TAG };
+union CurrentTemporalPosition
+switch (CurrentTemporalPositionTag){
+    case CURRENT_TEMPORAL_POSITION_SPECIFIED_TEMPORAL_POINT_TAG:
+        long
+            specified_temporal_point;
+    case CURRENT_TEMPORAL_POSITION_LOGICAL_TEMPORAL_VD_POINT_TAG:
+        long
+            logical_temporal_vd_point;
+};
+
+// Interface: RtComponentOrSocket Operation: setTemporalTermination
+// Interface: RtComponentOrSocket Operation: getTemporalTermination
+// Corresponding MHEG datatype: Temporal-Termination
+//=====
+enum TemporalTermination {
+    TEMPORAL_TERMINATION_FREEZE,
+    TEMPORAL_TERMINATION_STOP
+};
+
+// Interface: RtComponentOrSocket Operation: setSpeed
+// Corresponding MHEG datatype: Speed
+//=====
+enum SpeedTag { SPECIFIED_OGTR_TAG, SPEED_RATE_TAG, SCALING_FACTOR_TAG };
+union Speed
+switch (SpeedTag){
+    case SPECIFIED_OGTR_TAG:
+        long
+            specified_OGTR;
+    case SPEED_RATE_TAG:
+        long
+            speed_rate;
+    case SCALING_FACTOR_TAG:
+        long
+            scaling_factor;
+};
+
+// Corresponding MHEG datatype: Timestone-Position
+//=====
+enum TimestonePositionTag { TIMESTONE_POSITION_SPECIFIED_TEMPORAL_POINT_TAG,
+TIMESTONE_POSITION_LOGICAL_TEMPORAL_PD_POINT_TAG,
+TIMESTONE_POSITION_LOGICAL_TEMPORAL_VD_POINT_TAG };
+union TimestonePosition
+switch (TimestonePositionTag){
+    case TIMESTONE_POSITION_SPECIFIED_TEMPORAL_POINT_TAG:
+        long
+            specified_temporal_point;
+
+```
+
+```
+
+    case TIMESTONE_POSITION_LOGICAL_TEMPORAL_PD_POINT_TAG:
+        long
+            logical_temporal_PD_point;
+    case TIMESTONE_POSITION_LOGICAL_TEMPORAL_VD_POINT_TAG:
+        long
+            logical_temporal_VD_point;
+};
+
+// Interface: RtComponentOrSocket Operation: getVDLength
+// Corresponding MHEG datatype: GT-Indicator
+//=====
+enum GTIndicator {
+    OGTU,
+    RGTU
+};
+
+// Corresponding MHEG datatype: Perceptible-Projection
+//=====
+enum PerceptibleProjectionTag { SPECIFIED_SIZE_TAG, IOGSR_SCALING_FACTOR_TAG,
+COGSR_SCALING_FACTOR_TAG };
+union PerceptibleProjection
+switch (PerceptibleProjectionTag){
+    case SPECIFIED_SIZE_TAG:
+        long
+            specified_size;
+    case IOGSR_SCALING_FACTOR_TAG:
+        long
+            iogsr_scaling_factor;
+    case COGSR_SCALING_FACTOR_TAG:
+        long
+            cogsr_scaling_factor;
+};
+
+// Interface: RtComponentOrSocket Operation: setAspectRatioPreserved
+// Interface: RtComponentOrSocket Operation: getAspectRatio
+// Corresponding MHEG datatype: Aspect-Ratio
+//=====
+enum AspectRatio {
+    PRESERVED,
+    NOT_PRESERVED
+};
+
+// Interface: RtComponentOrSocket Operation: setVisibleSize
+// Interface: RtComponentOrSocket Operation: getVSGS
+// Corresponding MHEG datatype: VSGS
+//=====
+enum VSGS {
+    THIS,
+    RELATIVE
+};
+
+// Corresponding MHEG datatype: Size-Attribute
+//=====
+enum SizeAttributeTag { SIZE_ATTRIBUTE_SPECIFIED_SIZE_TAG,
+SIZE_ATTRIBUTE_IVS_RELATIVE_TAG, SIZE_ATTRIBUTE_CVS_RELATIVE_TAG };
+union SizeAttribute
+switch (SizeAttributeTag){
+    case SIZE_ATTRIBUTE_SPECIFIED_SIZE_TAG:
+        long
+            specified_size;
+    case SIZE_ATTRIBUTE_IVS_RELATIVE_TAG:
+        long
+            ivs_relative;
+    case SIZE_ATTRIBUTE_CVS_RELATIVE_TAG:
+        long
+            cvs_relative;
+};
+
+```
+
+```
+
+// Interface: RtComponentOrSocket Operation: setVisibleSizesAdjustment
+// Corresponding MHEG datatype: Adjustment-Axis
+//=====
+enum AdjustmentAxis {
+    X_AXIS,
+    Y_AXIS,
+    Z_AXIS
+};
+
+// Corresponding MHEG datatype: Sub-Socket-Reference
+//=====
+enum SubSocketReference {
+    SUB_SOCKET_REFERENCE_CHILD,
+    SUB_SOCKET_REFERENCE_DESCENDANT,
+    SUB_SOCKET_REFERENCE_QUESTION_MARK_CHILD,
+    SUB_SOCKET_REFERENCE_QUESTION_MARK_DESCENDANT
+};
+
+// Interface: RtComponentOrSocket Operation: setBox
+// Interface: RtComponentOrSocket Operation: getBox
+// Corresponding MHEG datatype: Box-Constants
+//=====
+enum BoxConstants {
+    PRESENTED,
+    NOT_PRESENTED
+};
+
+// Interface: RtComponentOrSocket Operation: setAttachmentPointPosition
+// Corresponding MHEG datatype: Reference-Type
+//=====
+enum ReferenceType {
+    VSIAP,
+    VSEAP
+};
+
+// Interface: RtComponentOrSocket Operation: setAttachmentPoint
+// Interface: RtComponentOrSocket Operation: setAttachmentPointPosition
+// Corresponding MHEG datatype: Attachment-Point-Type
+//=====
+enum AttachmentPointType {
+    ATTACHMENT_POINT_TYPE_PSAP,
+    ATTACHMENT_POINT_TYPE_VSIAP,
+    ATTACHMENT_POINT_TYPE_VSEAP
+};
+
+// Interface: RtComponentOrSocket Operation: setVisibleSizesAlignment
+// Corresponding MHEG datatype: Size-Border
+//=====
+enum SizeBorder {
+    TOP,
+    BOTTOM,
+    RIGHT,
+    LEFT,
+    UPPER_Z,
+    LOWER_Z,
+    CENTER_X,
+    CENTER_Y,
+    CENTER_Z
+};
+
+// Interface: RtComponentOrSocket Operation: setMovingAbility
+// Interface: RtComponentOrSocket Operation: setResizingAbility
+// Interface: RtComponentOrSocket Operation: setScalingAbility
+// Interface: RtComponentOrSocket Operation: setScrollingAbility
+// Interface: RtComponentOrSocket Operation: getMovingAbility
+// Interface: RtComponentOrSocket Operation: getResizingAbility
+// Interface: RtComponentOrSocket Operation: getScalingAbility
+// Interface: RtComponentOrSocket Operation: getScrollingAbility
+// Corresponding MHEG datatype: User-Controls
+//=====
+enum UserControls {
+    ALLOWED,
+    NOT_ALLOWED
+};
+
+```
+
+```
+
+// Interface: RtComponentOrSocket Operation: getPS
+// Corresponding MHEG datatype: GS-Indicator
+//=====
+enum GSIndicator {
+    OGSU,
+    RGSU
+};
+
+// Interface: RtComponentOrSocket Operation: getPSAP
+// Interface: RtComponentOrSocket Operation: getVSIAP
+// Corresponding MHEG datatype: Point-Type
+//=====
+enum PointType {
+    RELATIVE_POINT,
+    ABSOLUTE_POINT
+};
+
+// Interface: RtComponentOrSocket Operation: setSelectionStatus
+// Interface: RtComponentOrSocket Operation: getSelectionStatus
+// Corresponding MHEG datatype: Selection-Status-Value
+//=====
+enum SelectionStatusValue {
+    SELECTED,
+    NOT_SELECTED
+};
+
+// Interface: RtComponentOrSocket Operation:
+//   setSelectionPresentationEffectResponsibility
+// Interface: RtComponentOrSocket Operation:
+//   getSelectionPresentationEffectResponsibility
+// Interface: RtComponentOrSocket Operation:
+//   setModificationPresentationEffectResponsibility
+// Interface: RtComponentOrSocket Operation:
+//   getModificationPresentationEffectResponsibility
+// Corresponding MHEG datatype: Responsibility
+//=====
+enum Responsibility {
+    MHEG_ENGINE,
+    AUTHOR
+};
+
+// Interface: RtComponentOrSocket Operation: getEffectiveSelectability
+// Corresponding MHEG datatype: Effective-Selectability
+//=====
+enum EffectiveSelectability {
+    EFFECTIVELY_SELECTABLE,
+    EFFECTIVELY_NOT_SELECTABLE
+};
+
+// Interface: RtComponentOrSocket Operation: setModificationStatus
+// Interface: RtComponentOrSocket Operation: getModificationStatus
+// Corresponding MHEG datatype: Modification-Status-Value
+//=====
+enum ModificationStatusValue {
+    MODIFIED,
+    MODIFYING,
+    NOT_MODIFIED
+};
+
+// Interface: RtComponentOrSocket Operation: getEffectiveModifiability
+// Corresponding MHEG datatype: Effective-Modifiability
+//=====
+enum EffectiveModifiability {
+    EFFECTIVELY_MODIFIABLE,
+    EFFECTIVELY_NOT_MODIFIABLE
+};
+
+```
+
+```
+
+// Interface: RtCompositeOrStructuralSocket Operation: setResizingStrategy
+// Interface: RtCompositeOrStructuralSocket Operation: getResizingStrategy
+// Corresponding MHEG datatype: Resizing-Strategy
+//=====
+enum ResizingStrategy {
+    FIXED,
+    MINIMUM,
+    GROWS_ONLY
+};
+
+// Interface: RtCompositeOrStructuralSocket Operation: setMenuInteractionStyle
+// Interface: RtCompositeOrStructuralSocket Operation:
+//   setScrollingListInteractionStyle
+// Interface: RtContentOrPresentableSocket Operation: setSliderInteractionStyle
+// Corresponding MHEG datatype: Orientation
+//=====
+enum Orientation {
+    HORIZONTAL,
+    VERTICAL
+};
+
+// Corresponding MHEG datatype: Presentation-Persistence
+//=====
+enum PresentationPersistence {
+    PERSISTENT,
+    NOT_PERSISTENT
+};
+
+// Interface: RtCompositeOrStructuralSocket Operation:
+//   setScrollingListInteractionStyle
+// Corresponding MHEG datatype: Slider-Side
+//=====
+enum SliderSide {
+    SIDE1,
+    SIDE2
+};
+
+// Interface: RtGenericContentOrPresentableSocket Operation: setAudibleVolume
+// Corresponding MHEG datatype: Audible-Volume
+//=====
+enum AudibleVolumeTag { SPECIFIED_VOLUME_TAG, LOGICAL_VOLUME_TAG,
+IOV_SCALING_FACTOR_TAG, OV_SCALING_FACTOR_TAG };
+union AudibleVolume
+switch (AudibleVolumeTag){
+    case SPECIFIED_VOLUME_TAG:
+        long
+        specified_volume;
+    case LOGICAL_VOLUME_TAG:
+        long
+        logical_volume;
+    case IOV_SCALING_FACTOR_TAG:
+        long
+        iov_scaling_factor;
+    case OV_SCALING_FACTOR_TAG:
+        long
+        ov_scaling_factor;
+};
+
+// Interface: RtGenericContentOrPresentableSocket Operation:
+//   setButtonInteractionStyle
+// Corresponding MHEG datatype: Presentation-State
+//=====
+enum PresentationState {
+    SELECTABLE_NOT_SELECTED,
+    SELECTABLE_SELECTED,
+    NOT_SELECTABLE_SELECTED,
+    NOT_SELECTABLE_NOT_SELECTED
+};
+
+// Corresponding MHEG datatype: Echo-Mode
+//=====
+enum EchoMode {
+    ITSELF,
+    HIDDEN
+};
+
+```
+
+```
+
+// Interface: RtContentOrPresentableSocket Operation:
+//   setEntryFieldInteractionStyle
+// Corresponding MHEG datatype: Echo-Style
+//=====
+enum EchoStyleTag { MODE_TAG, SPECIFIED_TAG };
+union EchoStyle
+switch (EchoStyleTag){
+    case MODE_TAG:
+        EchoMode
+        mode;
+    case SPECIFIED_TAG:
+        string
+        specified;
+};
+
+// Corresponding MHEG datatype: Channel-Reference
+//=====
+enum ChannelReferenceTag { CHANNEL_IDENTIFIER_TAG, ALIAS_TAG,
+NULL_CHANNEL_REFERENCE_TAG };
+union ChannelReference
+switch (ChannelReferenceTag){
+    case CHANNEL_IDENTIFIER_TAG:
+        ChannelIdentifier
+        channel_identifier;
+    case ALIAS_TAG:
+        Alias
+        alias;
+};
+
+// Corresponding MHEG datatype: Interval
+//=====
+struct Interval {
+    sequence<long,1>
+    start_point;
+    sequence<long,1>
+    end_point;
+};
+
+// Corresponding MHEG datatype: Generic-Volume-Range
+//=====
+struct GenericVolumeRange {
+    sequence<long,1>
+    maximum_volume;
+    sequence<long,1>
+    minimum_volume;
+};
+
+// Interface: Channel Operation: new
+// Corresponding MHEG datatype: Original-Def-Declaration
+//=====
+struct OriginalDefDeclaration {
+    sequence<long,1>
+    generic_temporal_ratio;
+    sequence<Interval,1>
+    x_axis_interval;
+    sequence<Interval,1>
+    y_axis_interval;
+    sequence<Interval,1>
+    z_axis_interval;
+    sequence<GenericVolumeRange,1>
+    audible_volume_range_declaration;
+};
+
+// Interface: Channel Operation: getAvailability
+// Corresponding MHEG datatype: Channel-Status-ValueCHANNEL-STATUS-VALUE-
+//=====
+enum ChannelStatusValue {
+    CHANNEL_STATUS_VALUE_AVAILABLE,
+    CHANNEL_STATUS_VALUE_NOT_AVAILABLE,
+    CHANNEL_STATUS_VALUE_PROCESSING
+};
+
+```
+
+```
+
+// Interface: Channel Operation: setPerceptability
+// Interface: Channel Operation: getPerceptability
+// Corresponding MHEG datatype: Channel-Perceptability-Values
+//=====
+enum ChannelPerceptabilityValue {
+    ON,
+    OFF
+};
+
+// Interface: NotificationManager Operation: getNotification
+// Interface: MhContent Operation: getData
+// Corresponding MHEG datatype: Generic-Value
+//=====
+enum GenericValueTag { BOOLEAN_FIELD_TAG, NUMERIC_TAG, STRING_FIELD_TAG,
+    GENERIC_LIST_TAG, UNSPECIFIED_TAG };
+union GenericValue
+switch (GenericValueTag){
+    case BOOLEAN_FIELD_TAG:
+        boolean
+        boolean_field;
+    case NUMERIC_TAG:
+        long
+        numeric;
+    case STRING_FIELD_TAG:
+        string
+        string_field;
+    case GENERIC_LIST_TAG:
+        sequence<GenericValue>
+        generic_list;
+};
+
+// Corresponding MHEG datatype: Generic-String
+//=====
+enum GenericStringTag { GENERIC_STRING_CONSTANT_TAG,
+    GENERIC_STRING_UNSPECIFIED_TAG };
+union GenericString
+switch (GenericStringTag){
+    case GENERIC_STRING_CONSTANT_TAG:
+        string
+        constant;
+};
+
+// Interface: Socket Operation: setVisibleDurationPosition
+// Corresponding MHEG datatype: Visible-Duration
+//=====
+enum VisibleDurationPositionTag {
+    VISIBLE_DURATION_POSITION_SPECIFIED_TEMPORAL_POINT_TAG,
+    VISIBLE_DURATION_POSITION_LOGICAL_TEMPORAL_PD_POINT_TAG,
+    VISIBLE_DURATION_POSITION_LOGICAL_TEMPORAL_VD_POINT_TAG };
+union VisibleDurationPosition
+switch (VisibleDurationPositionTag){
+    case VISIBLE_DURATION_POSITION_SPECIFIED_TEMPORAL_POINT_TAG:
+        long
+        specified_temporal_point;
+    case VISIBLE_DURATION_POSITION_LOGICAL_TEMPORAL_PD_POINT_TAG:
+        long
+        logical_temporal_PD_point;
+    case VISIBLE_DURATION_POSITION_LOGICAL_TEMPORAL_VD_POINT_TAG:
+        long
+        logical_temporal_VD_point;
+};
+
+// Interface: RtComponentOrSocket Operation: getRGS
+// Corresponding MHEG datatype: none
+//=====
+enum RGSValueTag { RGS_VALUE_CHANNEL_IDENTIFIER_TAG, RGS_VALUE_NULL_CHANNEL_TAG,
+    RGS_VALUE_PRGS_TAG };
+union RGSValue
+switch (RGSValueTag){
+    case RGS_VALUE_CHANNEL_IDENTIFIER_TAG:
+        ChannelIdentifier
+        channel_identifier;
+};
+
+```
+
+```
+
+// Corresponding MHEG datatype: Generic-Numeric
+//=====
+enum GenericNumericTag { GENERIC_NUMERIC_CONSTANT_TAG,
+GENERIC_NUMERIC_UNSPECIFIED_TAG };
+union GenericNumeric
+switch (GenericNumericTag){
+    case GENERIC_NUMERIC_CONSTANT_TAG:
+        long
+            constant;
+};
+
+// Interface: RtComponentOrSocket Operation: getSelectionMode
+// Corresponding MHEG datatype: none
+//=====
+enum SelectionModeValueTag { USER_INTERACTION_TAG, NO_SELECTION_TAG,
+MHEG_ACTION_TAG, USING_APPLICATION_ACTION_TAG };
+union SelectionModeValue
+switch (SelectionModeValueTag){
+    case USER_INTERACTION_TAG:
+        unsigned long
+            user_interaction;
+};
+
+// Interface: RtComponentOrSocket Operation: getModificationMode
+// Corresponding MHEG datatype: none
+//=====
+enum ModificationModeValueTag { MODIFICATION_MODE_VALUE_USER_INTERACTION_TAG,
+MODIFICATION_MODE_VALUE_NO_MODIFICATION_TAG,
+MODIFICATION_MODE_VALUE_MHEG_ACTION_TAG,
+MODIFICATION_MODE_VALUE_USING_APPLICATION_ACTION_TAG,
+MODIFICATION_MODE_VALUE_CHILD_TAG };
+union ModificationModeValue
+switch (ModificationModeValueTag){
+    case MODIFICATION_MODE_VALUE_USER_INTERACTION_TAG:
+        unsigned long
+            user_interaction;
+};
+
+// Corresponding MHEG datatype: External-Identifier
+//=====
+enum ExternalIdentifierTag { EXTERNAL_LONG_ID_TAG, PUBLIC_ID_TAG,
+SYSTEM_ID_TAG };
+union ExternalIdentifier
+switch (ExternalIdentifierTag){
+    case EXTERNAL_LONG_ID_TAG:
+        ExternalLongIdentifier
+            external_long_id;
+    case PUBLIC_ID_TAG:
+        PublicIdentifier
+            public_id;
+    case SYSTEM_ID_TAG:
+        SystemIdentifier
+            system_id;
+};
+
+// Corresponding MHEG datatype: Container-Tail
+//=====
+struct ContainerTail {
+    sequence<long>
+        indexes;
+    enum ContainerTailTag { INDEX_TAG, CONTAINER_CHILD_REF_TAG } tag;
+    union ContainerTail
+    switch (ContainerTailTag){
+        case INDEX_TAG:
+            long
+                index;
+        case CONTAINER_CHILD_REF_TAG:
+            ContainerChildReference
+                container_child_ref;
+    } end;
+};
+
+```
+
+```
+
+// Corresponding MHEG datatype: Specified-Sizes
+//=====
+struct SpecifiedSizes {
+    sequence<GenericNumeric,1>
+        x_axis_length;
+    sequence<GenericNumeric,1>
+        y_axis_length;
+    sequence<GenericNumeric,1>
+        z_axis_length;
+};
+
+// Corresponding MHEG datatype: Attachment-Attribute
+//=====
+enum AttachmentAttributeTag { SPECIFIED_POSITION_TAG, LOGICAL_POSITION_TAG };
+union AttachmentAttribute
+switch (AttachmentAttributeTag){
+    case SPECIFIED_POSITION_TAG:
+        GenericNumeric
+            specified_position;
+    case LOGICAL_POSITION_TAG:
+        GenericNumeric
+            logical_position;
+};
+
+// Corresponding MHEG datatype: Length-Attribute
+//=====
+enum LengthAttributeTag { SPECIFIED_LENGTH_TAG, RELATIVE_LENGTH_TAG };
+union LengthAttribute
+switch (LengthAttributeTag){
+    case SPECIFIED_LENGTH_TAG:
+        GenericNumeric
+            specified_length;
+    case RELATIVE_LENGTH_TAG:
+        GenericNumeric
+            relative_length;
+};
+
+// Interface: RtComponentOrSocket Operation: getPS
+// Interface: RtComponentOrSocket Operation: getPSAP
+// Interface: RtComponentOrSocket Operation: getVS
+// Interface: RtComponentOrSocket Operation: getVSIAP
+// Interface: RtComponentOrSocket Operation: getVSIAPPosition
+// Interface: RtComponentOrSocket Operation: getVSEAP
+// Interface: RtComponentOrSocket Operation: getVSEAPPosition
+// Corresponding MHEG datatype: Specified-Position
+//=====
+struct SpecifiedPosition {
+    GenericNumeric
+        x_point;
+    GenericNumeric
+        y_point;
+    GenericNumeric
+        z_point;
+};
+
+// Interface: RtComponentOrSocket Operation: setPresentationPriority
+// Corresponding MHEG datatype: Presentation-Priority
+//=====
+enum PresentationPriorityTag { GENERIC_NUMERIC_TAG, PRIORITY_LEVEL_TAG };
+union PresentationPriority
+switch (PresentationPriorityTag){
+    case GENERIC_NUMERIC_TAG:
+        GenericNumeric
+            generic_numeric;
+    case PRIORITY_LEVEL_TAG:
+        PriorityLevel
+            priority_level;
+};
+
+```
+
+```
+
+// Interface: RtComponentOrSocket Operation: setTimestones
+// Corresponding MHEG datatype: Timestone
+//=====
+struct Timestone {
+    long
+        timestone_identifier;
+    TimestonePosition
+        timestone_position;
+};
+
+// Interface: RtComponentOrSocket Operation: setVisibleSize
+// Corresponding MHEG datatype: none
+//=====
+enum VSTag { X_SIZE_ATTRIBUTE_TAG, Y_SIZE_ATTRIBUTE_TAG, Z_SIZE_ATTRIBUTE_TAG };
+union VS
+switch (VSTag){
+    case X_SIZE_ATTRIBUTE_TAG:
+        SizeAttribute
+            x_size_attribute;
+    case Y_SIZE_ATTRIBUTE_TAG:
+        SizeAttribute
+            y_size_attribute;
+    case Z_SIZE_ATTRIBUTE_TAG:
+        SizeAttribute
+            z_size_attribute;
+};
+
+// Interface: RtComponentOrSocket Operation: setAttachmentPoint
+// Corresponding MHEG datatype: none
+//=====
+struct AttachmentPoint {
+    sequence<AttachmentAttribute,1>
+        x_attachment;
+    sequence<AttachmentAttribute,1>
+        y_attachment;
+    sequence<AttachmentAttribute,1>
+        z_attachment;
+};
+
+// Interface: RtComponentOrSocket Operation: setAttachmentPointPosition
+// Corresponding MHEG datatype: Lengths
+//=====
+struct Lengths {
+    sequence<LengthAttribute,1>
+        x_length;
+    sequence<LengthAttribute,1>
+        y_length;
+    sequence<LengthAttribute,1>
+        z_length;
+};
+
+// Interface: RtMultiplexedContentOrPresentableSocket Operation: getStreamChosen
+// Corresponding MHEG datatype: none
+//=====
+enum StreamValueTag { STREAM_IDENTIFIER_TAG, NO_STREAM_CHOSEN_TAG };
+union StreamValue
+switch (StreamValueTag){
+    case STREAM_IDENTIFIER_TAG:
+        StreamIdentifier
+            stream_identifier;
+};
+
+// Interface: MhContent Operation: setData
+// Corresponding MHEG datatype: Data-Element
+//=====
+struct DataElement {
+    sequence<long>
+        element_list_index;
+    GenericValue
+        generic_value;
+};
+
+```
+
+```
+
+// Interface: NotificationManager Operation: getNotification
+// Interface: MhObject Operation: bind
+// Interface: MhObject Operation: prepare
+// Interface: MhGenericContent Operation: copy
+// Corresponding MHEG datatype: Mh-Object-Reference
+//=====
+struct MhObjectReference {
+enum MhObjectReferenceHeadTag { MHEG_IDENTIFIER_TAG, EXTERNAL_IDENTIFIER_TAG,
+ALIAS_TAG, NULL_OBJECT_REF_TAG } head_tag;
+union MhObjectReferenceHead
+switch (MhObjectReferenceHeadTag){
+case MHEG_IDENTIFIER_TAG:
+MHEGIdentifier
+mheg_identifier;
+case EXTERNAL_IDENTIFIER_TAG:
+ExternalIdentifier
+external_identifier;
+case ALIAS_TAG:
+Alias
+alias;
+} head;
+enum MhObjectReferenceTailTag { CONTAINER_ELEMENT_REFERENCE_TAG,
+OTHER_REFERENCE_TAG } tail_tag;
+union MhObjectReferenceTail
+switch (MhObjectReferenceTailTag){
+case CONTAINER_ELEMENT_REFERENCE_TAG:
+ContainerTail
+container_tail;
+} tail;
+};
+
+// Interface: RtComponentOrSocket Operation: setPerceptibleSizeProjection
+// Corresponding MHEG datatype: Perceptible-Size-Projection
+//=====
+struct PerceptibleSizeProjection {
+sequence<PerceptibleProjection,1>
+x_perceptible_size_projection;
+sequence<PerceptibleProjection,1>
+y_perceptible_size_projection;
+sequence<PerceptibleProjection,1>
+z_perceptible_size_projection;
+};
+
+// Corresponding MHEG datatype: Rt-Object-Number-Reference
+//=====
+enum RtObjectNumberReferenceTag { RT_OBJECT_NUMBER_TAG, RT_DYNAMIC_REFERENCE_TAG
+};
+union RtObjectNumberReference
+switch (RtObjectNumberReferenceTag){
+case RT_OBJECT_NUMBER_TAG:
+long
+rt_object_number;
+case RT_DYNAMIC_REFERENCE_TAG:
+RtDynamicReference
+rt_dynamic_reference;
+};
+
+// Interface: RtObject Operation: bind
+// Interface: RtObject Operation: new
+// Corresponding MHEG datatype: Rt-Object-Reference
+//=====
+struct RtObjectReference {
+MhObjectReference
+model_object_reference;
+RtObjectNumberReference
+rt_object_number_reference;
+};
+
+```
+
+```
+
+// Corresponding MHEG datatype: Rt-Reference
+//=====
+enum RtReferenceTag { RT_REFERENCE_RT_OBJECT_REFERENCE_TAG,
+RT_REFERENCE_ALIAS_TAG, RT_REFERENCE_NULL_RT_OBJECT_TAG };
+union RtReference
+switch (RtReferenceTag){
+    case RT_REFERENCE_RT_OBJECT_REFERENCE_TAG:
+        RtObjectReference
+            rt_object_reference;
+    case RT_REFERENCE_ALIAS_TAG:
+        Alias
+            alias;
+};
+
+// Corresponding MHEG datatype: Socket-Tail
+//=====
+struct SocketTail {
+    sequence<long>
+        indexes;
+    enum SocketTailTag { INDEX_TAG, SUB_SOCKET_REF_TAG } tag;
+    union SocketTail
+    switch (SocketTailTag){
+        case INDEX_TAG:
+            long
+                index;
+        case SUB_SOCKET_REF_TAG:
+            SubSocketReference
+                sub_socket_ref;
+    } end;
+};
+
+// Corresponding MHEG datatype: Indexed-Child-Socket
+//=====
+struct IndexedChildSocket {
+    long
+        index;
+    SocketTail
+        tail;
+};
+
+// Interface: Socket Operation: bind
+// Interface: Socket Operation: getIdentification
+// Corresponding MHEG datatype: Socket-Identification
+//=====
+struct SocketIdentification {
+    RtReference
+        rt_composite_reference;
+    SocketTail
+        socket_tail;
+};
+
+// Interface: Socket Operation: bind
+// Corresponding MHEG datatype: Socket-Reference
+//=====
+enum SocketReferenceTag { SOCKET_REFERENCE_SOCKET_IDENT_TAG,
+SOCKET_REFERENCE_ALIAS_TAG };
+union SocketReference
+switch (SocketReferenceTag){
+    case SOCKET_REFERENCE_SOCKET_IDENT_TAG:
+        SocketIdentification
+            socket_ident;
+    case SOCKET_REFERENCE_ALIAS_TAG:
+        Alias
+            alias;
+};
+
+// Corresponding MHEG datatype: Rt-Object-Socket-Reference
+//=====
+enum RtObjectSocketReferenceTag { RT_REFERENCE_TAG, SOCKET_REFERENCE_TAG };
+union RtObjectSocketReference
+switch (RtObjectSocketReferenceTag){
+    case RT_REFERENCE_TAG:
+        RtReference
+            rt_reference;
+
+```
+
+```
+
+    case SOCKET_REFERENCE_TAG:
+        SocketReference
+            socket_reference;
+};
+
+// Interface: RtCompositeOrStructuralSocket Operation:
+//   setScrollingListInteractionStyle
+// Interface: RtContentOrPresentableSocket Operation: setSliderInteractionStyle
+// Interface: RtContentOrPresentableSocket Operation:
+//   setEntryFieldInteractionStyle
+// Interface: Channel Operation: getAssignedPerceptibles
+// Corresponding MHEG datatype: Perceptible-Reference
+//=====
+enum PerceptibleReferenceTag { RT_COMPONENT_REFERENCE_TAG,
+RT_SOCKET_REFERENCE_TAG };
+union PerceptibleReference
+switch (PerceptibleReferenceTag){
+    case RT_COMPONENT_REFERENCE_TAG:
+        RtReference
+            rt_component_reference;
+    case RT_SOCKET_REFERENCE_TAG:
+        SocketReference
+            rt_socket_reference;
+};
+
+// Interface: RtCompositeOrStructuralSocket Operation:
+//   setScrollingListInteractionStyle
+// Corresponding MHEG datatype: Separator
+//=====
+enum SeparatorTag { NO_TAG, YES_DEFAULT_TAG, SEPARATOR_PIECE_TAG };
+union Separator
+switch (SeparatorTag){
+    case SEPARATOR_PIECE_TAG:
+        PerceptibleReference
+            separator_piece;
+};
+
+// Interface: RtCompositeOrStructuralSocket Operation: setMenuInteractionStyle
+// Corresponding MHEG datatype: Association
+//=====
+struct Association {
+    sequence<SocketReference,1>
+        title;
+    sequence<Separator,1>
+        separator;
+    sequence<SocketReference,1>
+        submenu;
+    sequence<PresentationPersistence,1>
+        submenu_presentation_persistence;
+    sequence<Orientation,1>
+        submenu_orientation;
+};
+
+// Interface: RtSocket Operation: plug
+// Corresponding MHEG datatype: Plug-In
+//=====
+enum PlugInTag { PLUG_IN_RT_COMPONENT_REFERENCE_TAG,
+PLUG_IN_COMPONENT_REFERENCE_TAG, PLUG_IN_LABEL_TAG };
+union PlugIn
+switch (PlugInTag){
+    case PLUG_IN_RT_COMPONENT_REFERENCE_TAG:
+        RtObjectReference
+            rt_component_reference;
+    case PLUG_IN_COMPONENT_REFERENCE_TAG:
+        MhObjectReference
+            component_reference;
+    case PLUG_IN_LABEL_TAG:
+        GenericString
+            label;
+};
+
+```
+
+```
+
+// Interface: RtComponentOrSocket Operation: getVSEAPPosition
+// Corresponding MHEG datatype: none
+//=====
+enum ReferencePointTag { VSEAP_POSITION_ORIGIN_RGS_TAG,
+VSEAP_POSITION_ORIGIN_CGS_TAG, VSEAP_POSITION_SAME_RGS_COMPONENT_TAG,
+VSEAP_POSITION_SAME_CGS_COMPONENT_TAG, VSEAP_POSITION_SPECIFIED_POSITION_TAG };
+union ReferencePoint
+switch (ReferencePointTag){
+    case VSEAP_POSITION_SAME_RGS_COMPONENT_TAG:
+        RtObjectSocketReference
+            same_RGS_component;
+    case VSEAP_POSITION_SAME_CGS_COMPONENT_TAG:
+        RtObjectSocketReference
+            same_CGS_component;
+    case VSEAP_POSITION_SPECIFIED_POSITION_TAG:
+        SpecifiedPosition
+            specified_position;
+};
+
+// Interface: RtScript Operation: setParameters
+// Corresponding MHEG datatype: Parameter
+//=====
+enum ParameterTag { GENERIC_VALUE_TAG, MH_OBJECT_REFERENCE_TAG };
+union Parameter
+switch (ParameterTag){
+    case GENERIC_VALUE_TAG:
+        GenericValue
+            generic_value;
+    case MH_OBJECT_REFERENCE_TAG:
+        MhObjectReference
+            mh_object_reference;
+};
+
+// Interface: RtObjectOrSocket Operation: setGlobalBehaviour
+// Corresponding MHEG datatype: Global-Behaviour
+//=====
+enum GlobalBehaviourTag { GLOBAL_BEHAVIOUR_RT_REFERENCE_TAG,
+GLOBAL_BEHAVIOUR_GENERIC_LIST_TAG, GLOBAL_BEHAVIOUR_UNSPECIFIED_TAG };
+union GlobalBehaviour
+switch (GlobalBehaviourTag){
+    case GLOBAL_BEHAVIOUR_RT_REFERENCE_TAG:
+        RtReference
+            rt_reference;
+    case GLOBAL_BEHAVIOUR_GENERIC_LIST_TAG:
+        GenericValue
+            generic_list;
+};
+
+// Interface: RtComponentOrSocket Operation: setVisibleSizesAdjustment
+// Corresponding MHEG datatype: Adjustment-PolicyADJUSTMENT-POLICY-
+//=====
+enum AdjustmentPolicyTag { ADJUSTMENT_POLICY_COMPONENT_REFERENCE_TAG,
+ADJUSTMENT_POLICY_SPECIFIED_TAG, ADJUSTMENT_POLICY_GREATEST_TAG,
+ADJUSTMENT_POLICY_SMALLEST_TAG };
+union AdjustmentPolicy
+switch (AdjustmentPolicyTag){
+    case ADJUSTMENT_POLICY_COMPONENT_REFERENCE_TAG:
+        RtObjectSocketReference
+            component_reference;
+    case ADJUSTMENT_POLICY_SPECIFIED_TAG:
+        SpecifiedSizes
+            specified;
+};
+
+```
+
+```
+
+// Interface: RtObject Operation: bind
+// Interface: RtObject Operation: new
+// Interface: RtObject Operation: getIdentifier
+// Corresponding MHEG datatype: none
+//=====
+struct RtObjectIdentifier {
+    MHEGIdentifier
+    model_object_id;
+    long
+    rt_object_number;
+};
+
+// Interface: RtGenericContentOrPresentableSocket Operation:
+//   setButtonInteractionStyle
+// Corresponding MHEG datatype: Alternate-Presentation-State
+//=====
+struct AlternatePresentation {
+    PresentationState
+    presentation_state;
+    PerceptibleReference
+    perceptible_target;
+};
+
+```
+
+### 7.1.37 Exceptions
+
+#### 7.1.37.1 InvalidTarget exception
+
+##### Description:
+
+The InvalidTarget exception is raised when the targeted MHEG entity is not available. The `period` member returns the current period of the target.
+
+#### 7.1.37.2 InvalidParameter exception
+
+##### Description:
+
+The InvalidParameter exception is raised when the value of one of the parameters prohibits the normal execution of the action. The `completion_status` member indicates whether the action was completed (with a default value assigned to the inadequate parameter) or not. The `parameter_number` member identifies the rank of the invalid parameter.
+
+#### 7.1.37.3 NotBound exception
+
+##### Description:
+
+The NotBound exception is raised when the interface object instance is not bound with an MHEG entity.
+
+#### 7.1.37.4 AlreadyBound exception
+
+##### Description:
+
+The AlreadyBound exception is raised when the interface object instance is already bound with an MHEG entity. The `entity_identifier` member identifies the bound entity.
+
+#### 7.1.37.5 IDL definition
+
+```
+
+exception InvalidTarget {
+    unsigned short period;
+};
+
+enum CompletionStatus { YES, NO};
+
+exception InvalidParameter {
+    CompletionStatus completion_status;
+    unsigned short period;
+};
+
+typedef long EntityIdentifier
+exception AlreadyBound {
+    EntityIdentifier entity_identifier;
+};
+
+exception NotBound {};
+
+```
+
+## 7.2 Optional primitives
+
+The following objects shall be used to modify MHEG objects in form b:
+
+- mhAction
+- mhComposite
+- mhContainer
+- mhContent
+- mhDescriptor
+- mhLink
+- mhMultiplexedContent
+- mhScript
+
+## Annex A
+
+### Complete IDL definition of the MHEG API
+
+```
+//=====
+typedef sequence<long> ApplicationIdentifier;
+// Corresponding MHEG datatype: Object-Number
+//=====
+typedef long ObjectNumber;
+
+// Interface: MhObject Operation: bind
+// Interface: MhObject Operation: prepare
+// Interface: MhObject Operation: getIdentifier
+// Corresponding MHEG datatype: MHEG-Identifier
+//=====
+struct MHEGIdentifier {
+    sequence<ApplicationIdentifier,1>
+        application_identifier;
+    ObjectNumber
+        object_number;
+};
+
+// Corresponding MHEG datatype: Public-Identifier
+//=====
+typedef string PublicIdentifier;
+
+// Corresponding MHEG datatype: System-Identifier
+//=====
+typedef string SystemIdentifier;
+
+// Corresponding MHEG datatype: External-Long-Identifier
+//=====
+struct ExternalLongIdentifier {
+    PublicIdentifier
+        public_identifier;
+    SystemIdentifier
+        system_identifier;
+};
+
+// Corresponding MHEG datatype: Alias
+//=====
+typedef string Alias;
+
+// Corresponding MHEG datatype: Container-Child-Reference
+//=====
+enum ContainerChildReference {
+    CHILD,
+    DESCENDANT
+};
+```
+
+```
+
+// Interface: MhObject Operation: getPreparationStatus
+// Corresponding MHEG datatype: Preparation-Status-Value
+//=====
+enum PreparationStatusValue {
+    READY,
+    NOT_READY,
+    PROCESSING
+};
+
+// Interface: MhMultiplexedContent Operation: setMultiplex
+// Interface: MhMultiplexedContent Operation: setDemultiplex
+// Interface: RtMultiplexedContentOrPresentableSocket Operation: setStreamChoice
+// Corresponding MHEG datatype: Stream-Identifier
+//=====
+typedef sequence<long> StreamIdentifier;
+
+// Corresponding MHEG datatype: Rt-Dynamic-Reference
+//=====
+enum RtDynamicReference {
+    QUESTION_MARK,
+    STAR
+};
+
+// Interface: RtObject Operation: getAvailabilityStatus
+// Corresponding MHEG datatype: Rt-Availibility-Status-Value
+//=====
+enum RtAvailabilityStatusValue {
+    RT_AVAILABILITY_STATUS_VALUE_AVAILABLE,
+    RT_AVAILABILITY_STATUS_VALUE_NOT_AVAILABLE,
+    RT_AVAILABILITY_STATUS_VALUE_PROCESSING
+};
+
+// Interface: RtObject Operation: getRunningStatus
+// Corresponding MHEG datatype: Running-Status-Value
+//=====
+enum RunningStatusValue {
+    RUNNING_STATUS_VALUE_RUNNING,
+    RUNNING_STATUS_VALUE_NOT_RUNNING,
+    RUNNING_STATUS_VALUE_PROCESSING
+};
+
+// Interface: RtScript Operation: getTerminationStatus
+// Corresponding MHEG datatype: Termination-Status-Value
+//=====
+enum TerminationStatusValue {
+    TERMINATED,
+    NOT_TERMINATED
+};
+
+// Interface: RtComponentOrSocket Operation: setRGS
+// Interface: Channel Operation: getIdentifier
+// Corresponding MHEG datatype: Channel-Identifier
+//=====
+typedef long ChannelIdentifier;
+
+// Corresponding MHEG datatype: Priority-Level
+//=====
+enum PriorityLevel {
+    INCREMENT_PRIORITY,
+    DECREMENT_PRIORITY
+};
+
+// Interface: RtComponentOrSocket Operation: setVisibleDuration
+// Corresponding MHEG datatype: Temporal-Position
+//=====
+enum TemporalPositionTag { SPECIFIED_TEMPORAL_POINT_TAG,
+LOGICAL_TEMPORAL_PD_POINT_TAG };
+union TemporalPosition
+switch (TemporalPositionTag){
+    case SPECIFIED_TEMPORAL_POINT_TAG:
+        long
+            specified_temporal_point;
+
+```
+
+```
+
+    case LOGICAL_TEMPORAL_PD_POINT_TAG:
+        long
+            logical_temporal_PD_point;
+};
+
+// Interface: RtComponentOrSocket Operation: setCurrentTemporalPosition
+// Corresponding MHEG datatype: Current-Temporal-Position
+//=====
+enum CurrentTemporalPositionTag {
+CURRENT_TEMPORAL_POSITION_SPECIFIED_TEMPORAL_POINT_TAG,
+CURRENT_TEMPORAL_POSITION_LOGICAL_TEMPORAL_VD_POINT_TAG };
+union CurrentTemporalPosition
+switch (CurrentTemporalPositionTag){
+    case CURRENT_TEMPORAL_POSITION_SPECIFIED_TEMPORAL_POINT_TAG:
+        long
+            specified_temporal_point;
+    case CURRENT_TEMPORAL_POSITION_LOGICAL_TEMPORAL_VD_POINT_TAG:
+        long
+            logical_temporal_vd_point;
+};
+
+// Interface: RtComponentOrSocket Operation: setTemporalTermination
+// Interface: RtComponentOrSocket Operation: getTemporalTermination
+// Corresponding MHEG datatype: Temporal-Termination
+//=====
+enum TemporalTermination {
+    TEMPORAL_TERMINATION_FREEZE,
+    TEMPORAL_TERMINATION_STOP
+};
+
+// Interface: RtComponentOrSocket Operation: setSpeed
+// Corresponding MHEG datatype: Speed
+//=====
+enum SpeedTag { SPECIFIED_OGTR_TAG, SPEED_RATE_TAG, SCALING_FACTOR_TAG };
+union Speed
+switch (SpeedTag){
+    case SPECIFIED_OGTR_TAG:
+        long
+            specified_OGTR;
+    case SPEED_RATE_TAG:
+        long
+            speed_rate;
+    case SCALING_FACTOR_TAG:
+        long
+            scaling_factor;
+};
+
+// Corresponding MHEG datatype: Timestone-Position
+//=====
+enum TimestonePositionTag { TIMESTONE_POSITION_SPECIFIED_TEMPORAL_POINT_TAG,
+TIMESTONE_POSITION_LOGICAL_TEMPORAL_PD_POINT_TAG,
+TIMESTONE_POSITION_LOGICAL_TEMPORAL_VD_POINT_TAG };
+union TimestonePosition
+switch (TimestonePositionTag){
+    case TIMESTONE_POSITION_SPECIFIED_TEMPORAL_POINT_TAG:
+        long
+            specified_temporal_point;
+    case TIMESTONE_POSITION_LOGICAL_TEMPORAL_PD_POINT_TAG:
+        long
+            logical_temporal_PD_point;
+    case TIMESTONE_POSITION_LOGICAL_TEMPORAL_VD_POINT_TAG:
+        long
+            logical_temporal_VD_point;
+};
+
+// Interface: RtComponentOrSocket Operation: getVDLength
+// Corresponding MHEG datatype: GT-Indicator
+//=====
+enum GTIndicator {
+    OGTU,
+    RGTU
+};
+
+```
+
+```
+
+// Corresponding MHEG datatype: Perceptible-Projection
+//=====
+enum PerceptibleProjectionTag { SPECIFIED_SIZE_TAG, IOGSR_SCALING_FACTOR_TAG,
+COGSR_SCALING_FACTOR_TAG };
+union PerceptibleProjection
+switch (PerceptibleProjectionTag){
+    case SPECIFIED_SIZE_TAG:
+        long
+            specified_size;
+    case IOGSR_SCALING_FACTOR_TAG:
+        long
+            iogsr_scaling_factor;
+    case COGSR_SCALING_FACTOR_TAG:
+        long
+            cogsr_scaling_factor;
+};
+
+// Interface: RtComponentOrSocket Operation: setAspectRatioPreserved
+// Interface: RtComponentOrSocket Operation: getAspectRatio
+// Corresponding MHEG datatype: Aspect-Ratio
+//=====
+enum AspectRatio {
+    PRESERVED,
+    NOT_PRESERVED
+};
+
+// Interface: RtComponentOrSocket Operation: setVisibleSize
+// Interface: RtComponentOrSocket Operation: getVSGS
+// Corresponding MHEG datatype: VSGS
+//=====
+enum VSGS {
+    THIS,
+    RELATIVE
+};
+
+// Corresponding MHEG datatype: Size-Attribute
+//=====
+enum SizeAttributeTag { SIZE_ATTRIBUTE_SPECIFIED_SIZE_TAG,
+SIZE_ATTRIBUTE_IVS_RELATIVE_TAG,
+SIZE_ATTRIBUTE_CVS_RELATIVE_TAG };
+union SizeAttribute
+switch (SizeAttributeTag){
+    case SIZE_ATTRIBUTE_SPECIFIED_SIZE_TAG:
+        long
+            specified_size;
+    case SIZE_ATTRIBUTE_IVS_RELATIVE_TAG:
+        long
+            ivs_relative;
+    case SIZE_ATTRIBUTE_CVS_RELATIVE_TAG:
+        long
+            cvs_relative;
+};
+
+// Interface: RtComponentOrSocket Operation: setVisibleSizesAdjustment
+// Corresponding MHEG datatype: Adjustment-Axis
+//=====
+enum AdjustmentAxis {
+    X_AXIS,
+    Y_AXIS,
+    Z_AXIS
+};
+
+// Corresponding MHEG datatype: Sub-Socket-Reference
+//=====
+enum SubSocketReference {
+    SUB_SOCKET_REFERENCE_CHILD,
+    SUB_SOCKET_REFERENCE_DESCENDANT,
+    SUB_SOCKET_REFERENCE_QUESTION_MARK_CHILD,
+    SUB_SOCKET_REFERENCE_QUESTION_MARK_DESCENDANT
+};
+
+```
+
+```
+
+// Interface: RtComponentOrSocket Operation: setBox
+// Interface: RtComponentOrSocket Operation: getBox
+// Corresponding MHEG datatype: Box-Constants
+//=====
+enum BoxConstants {
+    PRESENTED,
+    NOT_PRESENTED
+};
+
+// Interface: RtComponentOrSocket Operation: setAttachmentPointPosition
+// Corresponding MHEG datatype: Reference-Type
+//=====
+enum ReferenceType {
+    VSIAP,
+    VSEAP
+};
+
+// Interface: RtComponentOrSocket Operation: setAttachmentPoint
+// Interface: RtComponentOrSocket Operation: setAttachmentPointPosition
+// Corresponding MHEG datatype: Attachment-Point-Type
+//=====
+enum AttachmentPointType {
+    ATTACHMENT_POINT_TYPE_PSAP,
+    ATTACHMENT_POINT_TYPE_VSIAP,
+    ATTACHMENT_POINT_TYPE_VSEAP
+};
+
+// Interface: RtComponentOrSocket Operation: setVisibleSizesAlignment
+// Corresponding MHEG datatype: Size-Border
+//=====
+enum SizeBorder {
+    TOP,
+    BOTTOM,
+    RIGHT,
+    LEFT,
+    UPPER_Z,
+    LOWER_Z,
+    CENTER_X,
+    CENTER_Y,
+    CENTER_Z
+};
+
+// Interface: RtComponentOrSocket Operation: setMovingAbility
+// Interface: RtComponentOrSocket Operation: setResizingAbility
+// Interface: RtComponentOrSocket Operation: setScalingAbility
+// Interface: RtComponentOrSocket Operation: setScrollingAbility
+// Interface: RtComponentOrSocket Operation: getMovingAbility
+// Interface: RtComponentOrSocket Operation: getResizingAbility
+// Interface: RtComponentOrSocket Operation: getScalingAbility
+// Interface: RtComponentOrSocket Operation: getScrollingAbility
+// Corresponding MHEG datatype: User-Controls
+//=====
+enum UserControls {
+    ALLOWED,
+    NOT_ALLOWED
+};
+
+// Interface: RtComponentOrSocket Operation: getPS
+// Corresponding MHEG datatype: GS-Indicator
+//=====
+enum GSIndicator {
+    OGSU,
+    RGSU
+};
+
+// Interface: RtComponentOrSocket Operation: getPSAP
+// Interface: RtComponentOrSocket Operation: getVSIAP
+// Corresponding MHEG datatype: Point-Type
+//=====
+enum PointType {
+    RELATIVE_POINT,
+    ABSOLUTE_POINT
+};
+
+```
+
+```
+
+// Interface: RtComponentOrSocket Operation: setSelectionStatus
+// Interface: RtComponentOrSocket Operation: getSelectionStatus
+// Corresponding MHEG datatype: Selection-Status-Value
+//=====
+enum SelectionStatusValue {
+    SELECTED,
+    NOT_SELECTED
+};
+
+// Interface: RtComponentOrSocket Operation:
+//   setSelectionPresentationEffectResponsibility
+// Interface: RtComponentOrSocket Operation:
+//   getSelectionPresentationEffectResponsibility
+// Interface: RtComponentOrSocket Operation:
+//   setModificationPresentationEffectResponsibility
+// Interface: RtComponentOrSocket Operation:
+//   getModificationPresentationEffectResponsibility
+// Corresponding MHEG datatype: Responsibility
+//=====
+enum Responsibility {
+    MHEG_ENGINE,
+    AUTHOR
+};
+
+// Interface: RtComponentOrSocket Operation: getEffectiveSelectability
+// Corresponding MHEG datatype: Effective-Selectability
+//=====
+enum EffectiveSelectability {
+    EFFECTIVELY_SELECTABLE,
+    EFFECTIVELY_NOT_SELECTABLE
+};
+
+// Interface: RtComponentOrSocket Operation: setModificationStatus
+// Interface: RtComponentOrSocket Operation: getModificationStatus
+// Corresponding MHEG datatype: Modification-Status-Value
+//=====
+enum ModificationStatusValue {
+    MODIFIED,
+    MODIFYING,
+    NOT_MODIFIED
+};
+
+// Interface: RtComponentOrSocket Operation: getEffectiveModifiability
+// Corresponding MHEG datatype: Effective-Modifiability
+//=====
+enum EffectiveModifiability {
+    EFFECTIVELY_MODIFIABLE,
+    EFFECTIVELY_NOT_MODIFIABLE
+};
+
+// Interface: RtCompositeOrStructuralSocket Operation: setResizingStrategy
+// Interface: RtCompositeOrStructuralSocket Operation: getResizingStrategy
+// Corresponding MHEG datatype: Resizing-Strategy
+//=====
+enum ResizingStrategy {
+    FIXED,
+    MINIMUM,
+    GROWS_ONLY
+};
+
+// Interface: RtCompositeOrStructuralSocket Operation: setMenuInteractionStyle
+// Interface: RtCompositeOrStructuralSocket Operation:
+//   setScrollingListInteractionStyle
+// Interface: RtContentOrPresentableSocket Operation: setSliderInteractionStyle
+// Corresponding MHEG datatype: Orientation
+//=====
+enum Orientation {
+    HORIZONTAL,
+    VERTICAL
+};
+
+```
+
+```
+
+// Corresponding MHEG datatype: Presentation-Persistence
+//=====
+enum PresentationPersistence {
+    PERSISTENT,
+    NOT_PERSISTENT
+};
+
+// Interface: RtCompositeOrStructuralSocket Operation:
+//   setScrollingListInteractionStyle
+// Corresponding MHEG datatype: Slider-Side
+//=====
+enum SliderSide {
+    SIDE1,
+    SIDE2
+};
+
+// Interface: RtGenericContentOrPresentableSocket Operation: setAudibleVolume
+// Corresponding MHEG datatype: Audible-Volume
+//=====
+enum AudibleVolumeTag { SPECIFIED_VOLUME_TAG, LOGICAL_VOLUME_TAG,
+IOV_SCALING_FACTOR_TAG,
+OV_SCALING_FACTOR_TAG };
+union AudibleVolume
+switch (AudibleVolumeTag){
+    case SPECIFIED_VOLUME_TAG:
+        long
+            specified_volume;
+    case LOGICAL_VOLUME_TAG:
+        long
+            logical_volume;
+    case IOV_SCALING_FACTOR_TAG:
+        long
+            iov_scaling_factor;
+    case OV_SCALING_FACTOR_TAG:
+        long
+            ov_scaling_factor;
+};
+
+// Interface: RtGenericContentOrPresentableSocket Operation:
+//   setButtonInteractionStyle
+// Corresponding MHEG datatype: Presentation-State
+//=====
+enum PresentationState {
+    SELECTABLE_NOT_SELECTED,
+    SELECTABLE_SELECTED,
+    NOT_SELECTABLE_SELECTED,
+    NOT_SELECTABLE_NOT_SELECTED
+};
+
+// Corresponding MHEG datatype: Echo-Mode
+//=====
+enum EchoMode {
+    ITSELF,
+    HIDDEN
+};
+
+// Interface: RtContentOrPresentableSocket Operation:
+//   setEntryFieldInteractionStyle
+// Corresponding MHEG datatype: Echo-Style
+//=====
+enum EchoStyleTag { MODE_TAG, SPECIFIED_TAG };
+union EchoStyle
+switch (EchoStyleTag){
+    case MODE_TAG:
+        EchoMode
+            mode;
+    case SPECIFIED_TAG:
+        string
+            specified;
+};
+
+```
+
+```
+
+// Corresponding MHEG datatype: Channel-Reference
+//=====
+enum ChannelReferenceTag { CHANNEL_IDENTIFIER_TAG, ALIAS_TAG,
+NULL_CHANNEL_REFERENCE_TAG };
+union ChannelReference
+switch (ChannelReferenceTag){
+    case CHANNEL_IDENTIFIER_TAG:
+        ChannelIdentifier
+            channel_identifier;
+    case ALIAS_TAG:
+        Alias
+            alias;
+};
+
+// Corresponding MHEG datatype: Interval
+//=====
+struct Interval {
+    sequence<long,1>
+        start_point;
+    sequence<long,1>
+        end_point;
+};
+
+// Corresponding MHEG datatype: Generic-Volume-Range
+//=====
+struct GenericVolumeRange {
+    sequence<long,1>
+        maximum_volume;
+    sequence<long,1>
+        minimum_volume;
+};
+
+// Interface: Channel Operation: new
+// Corresponding MHEG datatype: Original-Def-Declaration
+//=====
+struct OriginalDefDeclaration {
+    sequence<long,1>
+        generic_temporal_ratio;
+    sequence<Interval,1>
+        x_axis_interval;
+    sequence<Interval,1>
+        y_axis_interval;
+    sequence<Interval,1>
+        z_axis_interval;
+    sequence<GenericVolumeRange,1>
+        audible_volume_range_declaration;
+};
+
+// Interface: Channel Operation: getAvailability
+// Corresponding MHEG datatype: Channel-Status-ValueCHANNEL-STATUS-VALUE-
+//=====
+enum ChannelStatusValue {
+    CHANNEL_STATUS_VALUE_AVAILABLE,
+    CHANNEL_STATUS_VALUE_NOT_AVAILABLE,
+    CHANNEL_STATUS_VALUE_PROCESSING
+};
+
+// Interface: Channel Operation: setPerceptability
+// Interface: Channel Operation: getPerceptability
+// Corresponding MHEG datatype: Channel-Perceptability-Values
+//=====
+enum ChannelPerceptabilityValue {
+    ON,
+    OFF
+};
+
+// Interface: NotificationManager Operation: getNotification
+// Interface: MhContent Operation: getData
+// Corresponding MHEG datatype: Generic-Value
+//=====
+enum GenericValueTag { BOOLEAN_FIELD_TAG, NUMERIC_TAG, STRING_FIELD_TAG,
+GENERIC_LIST_TAG,
+UNSPECIFIED_TAG };
+union GenericValue
+
+```
+
+```
+
+switch (GenericValueTag){
+    case BOOLEAN_FIELD_TAG:
+        boolean
+        boolean_field;
+    case NUMERIC_TAG:
+        long
+        numeric;
+    case STRING_FIELD_TAG:
+        string
+        string_field;
+    case GENERIC_LIST_TAG:
+        sequence<GenericValue>
+        generic_list;
+};
+
+// Corresponding MHEG datatype: Generic-String
+//=====
+enum GenericStringTag { GENERIC_STRING_CONSTANT_TAG,
+GENERIC_STRING_UNSPECIFIED_TAG };
+union GenericString
+switch (GenericStringTag){
+    case GENERIC_STRING_CONSTANT_TAG:
+        string
+        constant;
+};
+
+// Interface: Socket Operation: setVisibleDurationPosition
+// Corresponding MHEG datatype: Visible-Duration
+//=====
+enum VisibleDurationPositionTag {
+VISIBLE_DURATION_POSITION_SPECIFIED_TEMPORAL_POINT_TAG,
+VISIBLE_DURATION_POSITION_LOGICAL_TEMPORAL_PD_POINT_TAG,
+VISIBLE_DURATION_POSITION_LOGICAL_TEMPORAL_VD_POINT_TAG };
+union VisibleDurationPosition
+switch (VisibleDurationPositionTag){
+    case VISIBLE_DURATION_POSITION_SPECIFIED_TEMPORAL_POINT_TAG:
+        long
+        specified_temporal_point;
+    case VISIBLE_DURATION_POSITION_LOGICAL_TEMPORAL_PD_POINT_TAG:
+        long
+        logical_temporal_PD_point;
+    case VISIBLE_DURATION_POSITION_LOGICAL_TEMPORAL_VD_POINT_TAG:
+        long
+        logical_temporal_VD_point;
+};
+
+// Interface: RtComponentOrSocket Operation: getRGS
+// Corresponding MHEG datatype: none
+//=====
+enum RGSValueTag { RGS_VALUE_CHANNEL_IDENTIFIER_TAG, RGS_VALUE_NULL_CHANNEL_TAG,
+RGS_VALUE_PRGS_TAG };
+union RGSValue
+switch (RGSValueTag){
+    case RGS_VALUE_CHANNEL_IDENTIFIER_TAG:
+        ChannelIdentifier
+        channel_identifier;
+};
+
+// Corresponding MHEG datatype: Generic-Numeric
+//=====
+enum GenericNumericTag { GENERIC_NUMERIC_CONSTANT_TAG,
+GENERIC_NUMERIC_UNSPECIFIED_TAG };
+union GenericNumeric
+switch (GenericNumericTag){
+    case GENERIC_NUMERIC_CONSTANT_TAG:
+        long
+        constant;
+};
+
+```
+
+```
+
+// Interface: RtComponentOrSocket Operation: getSelectionMode
+// Corresponding MHEG datatype: none
+//=====
+enum SelectionModeValueTag { USER_INTERACTION_TAG, NO_SELECTION_TAG,
+MHEG_ACTION_TAG,
+USING_APPLICATION_ACTION_TAG };
+union SelectionModeValue
+switch (SelectionModeValueTag){
+    case USER_INTERACTION_TAG:
+        unsigned long
+            user_interaction;
+};
+
+// Interface: RtComponentOrSocket Operation: getModificationMode
+// Corresponding MHEG datatype: none
+//=====
+enum ModificationModeValueTag { MODIFICATION_MODE_VALUE_USER_INTERACTION_TAG,
+MODIFICATION_MODE_VALUE_NO_MODIFICATION_TAG,
+MODIFICATION_MODE_VALUE_MHEG_ACTION_TAG,
+MODIFICATION_MODE_VALUE_USING_APPLICATION_ACTION_TAG,
+MODIFICATION_MODE_VALUE_CHILD_TAG };
+union ModificationModeValue
+switch (ModificationModeValueTag){
+    case MODIFICATION_MODE_VALUE_USER_INTERACTION_TAG:
+        unsigned long
+            user_interaction;
+};
+
+// Corresponding MHEG datatype: External-Identifier
+//=====
+enum ExternalIdentifierTag { EXTERNAL_LONG_ID_TAG, PUBLIC_ID_TAG, SYSTEM_ID_TAG
+};
+union ExternalIdentifier
+switch (ExternalIdentifierTag){
+    case EXTERNAL_LONG_ID_TAG:
+        ExternalLongIdentifier
+            external_long_id;
+    case PUBLIC_ID_TAG:
+        PublicIdentifier
+            public_id;
+    case SYSTEM_ID_TAG:
+        SystemIdentifier
+            system_id;
+};
+
+// Corresponding MHEG datatype: Container-Tail
+//=====
+struct ContainerTail {
+    sequence<long>
+        indexes;
+    enum ContainerTailTag { INDEX_TAG, CONTAINER_CHILD_REF_TAG } tag;
+    union ContainerTail
+    switch (ContainerTailTag){
+        case INDEX_TAG:
+            long
+                index;
+        case CONTAINER_CHILD_REF_TAG:
+            ContainerChildReference
+                container_child_ref;
+    } end;
+};
+
+// Corresponding MHEG datatype: Specified-Sizes
+//=====
+struct SpecifiedSizes {
+    sequence<GenericNumeric,1>
+        x_axis_length;
+    sequence<GenericNumeric,1>
+        y_axis_length;
+    sequence<GenericNumeric,1>
+        z_axis_length;
+};
+
+```
+
+```
+
+// Corresponding MHEG datatype: Attachment-Attribute
+//=====
+enum AttachmentAttributeTag { SPECIFIED_POSITION_TAG, LOGICAL_POSITION_TAG };
+union AttachmentAttribute
+switch (AttachmentAttributeTag){
+    case SPECIFIED_POSITION_TAG:
+        GenericNumeric
+            specified_position;
+    case LOGICAL_POSITION_TAG:
+        GenericNumeric
+            logical_position;
+};
+
+// Corresponding MHEG datatype: Length-Attribute
+//=====
+enum LengthAttributeTag { SPECIFIED_LENGTH_TAG, RELATIVE_LENGTH_TAG };
+union LengthAttribute
+switch (LengthAttributeTag){
+    case SPECIFIED_LENGTH_TAG:
+        GenericNumeric
+            specified_length;
+    case RELATIVE_LENGTH_TAG:
+        GenericNumeric
+            relative_length;
+};
+
+// Interface: RtComponentOrSocket Operation: getPS
+// Interface: RtComponentOrSocket Operation: getPSAP
+// Interface: RtComponentOrSocket Operation: getVS
+// Interface: RtComponentOrSocket Operation: getVSIAP
+// Interface: RtComponentOrSocket Operation: getVSIAPPosition
+// Interface: RtComponentOrSocket Operation: getVSEAP
+// Interface: RtComponentOrSocket Operation: getVSEAPPosition
+// Corresponding MHEG datatype: Specified-Position
+//=====
+struct SpecifiedPosition {
+    GenericNumeric
+        x_point;
+    GenericNumeric
+        y_point;
+    GenericNumeric
+        z_point;
+};
+
+// Interface: RtComponentOrSocket Operation: setPresentationPriority
+// Corresponding MHEG datatype: Presentation-Priority
+//=====
+enum PresentationPriorityTag { GENERIC_NUMERIC_TAG, PRIORITY_LEVEL_TAG };
+union PresentationPriority
+switch (PresentationPriorityTag){
+    case GENERIC_NUMERIC_TAG:
+        GenericNumeric
+            generic_numeric;
+    case PRIORITY_LEVEL_TAG:
+        PriorityLevel
+            priority_level;
+};
+
+// Interface: RtComponentOrSocket Operation: setTimestones
+// Corresponding MHEG datatype: Timestone
+//=====
+struct Timestone {
+    long
+        timestone_identifier;
+    TimestonePosition
+        timestone_position;
+};
+
+```
+
+```
+
+// Interface: RtComponentOrSocket Operation: setVisibleSize
+// Corresponding MHEG datatype: none
+ 
+enum VSTag { X_SIZE_ATTRIBUTE_TAG, Y_SIZE_ATTRIBUTE_TAG, Z_SIZE_ATTRIBUTE_TAG };
+union VS
+switch (VSTag){
+    case X_SIZE_ATTRIBUTE_TAG:
+        SizeAttribute
+            x_size_attribute;
+    case Y_SIZE_ATTRIBUTE_TAG:
+        SizeAttribute
+            y_size_attribute;
+    case Z_SIZE_ATTRIBUTE_TAG:
+        SizeAttribute
+            z_size_attribute;
+};
+
+// Interface: RtComponentOrSocket Operation: setAttachmentPoint
+// Corresponding MHEG datatype: none
+ 
+struct AttachmentPoint {
+    sequence<AttachmentAttribute,1>
+        x_attachment;
+    sequence<AttachmentAttribute,1>
+        y_attachment;
+    sequence<AttachmentAttribute,1>
+        z_attachment;
+};
+
+// Interface: RtComponentOrSocket Operation: setAttachmentPointPosition
+// Corresponding MHEG datatype: Lengths
+ 
+struct Lengths {
+    sequence<LengthAttribute,1>
+        x_length;
+    sequence<LengthAttribute,1>
+        y_length;
+    sequence<LengthAttribute,1>
+        z_length;
+};
+
+// Interface: RtMultiplexedContentOrPresentableSocket Operation: getStreamChosen
+// Corresponding MHEG datatype: none
+ 
+enum StreamValueTag { STREAM_IDENTIFIER_TAG, NO_STREAM_CHOSEN_TAG };
+union StreamValue
+switch (StreamValueTag){
+    case STREAM_IDENTIFIER_TAG:
+        StreamIdentifier
+            stream_identifier;
+};
+
+// Interface: MhContent Operation: setData
+// Corresponding MHEG datatype: Data-Element
+ 
+struct DataElement {
+    sequence<long>
+        element_list_index;
+    GenericValue
+        generic_value;
+};
+
+// Interface: NotificationManager Operation: getNotification
+// Interface: MhObject Operation: bind
+// Interface: MhObject Operation: prepare
+// Interface: MhGenericContent Operation: copy
+// Corresponding MHEG datatype: Mh-Object-Reference
+ 
+struct MhObjectReference {
+    enum MhObjectReferenceHeadTag { MHEG_IDENTIFIER_TAG, EXTERNAL_IDENTIFIER_TAG,
+    ALIAS_TAG, NULL_OBJECT_REF_TAG } head_tag;
+    union MhObjectReferenceHead
+
+```
+
+```
+
+switch (MhObjectReferenceHeadTag) {
+    case MHEG_IDENTIFIER_TAG:
+        MHEGIdentifier
+            mheg_identifier;
+    case EXTERNAL_IDENTIFIER_TAG:
+        ExternalIdentifier
+            external_identifier;
+    case ALIAS_TAG:
+        Alias
+            alias;
+} head;
+enum MhObjectReferenceTailTag { CONTAINER_ELEMENT_REFERENCE_TAG,
+OTHER_REFERENCE_TAG
+} tail_tag;
+union MhObjectReferenceTail
+switch (MhObjectReferenceTailTag) {
+    case CONTAINER_ELEMENT_REFERENCE_TAG:
+        ContainerTail
+            container_tail;
+} tail;
+};
+
+// Interface: RtComponentOrSocket Operation: setPerceptibleSizeProjection
+// Corresponding MHEG datatype: Perceptible-Size-Projection
+//=====
+struct PerceptibleSizeProjection {
+    sequence<PerceptibleProjection,1>
+        x_perceptible_size_projection;
+    sequence<PerceptibleProjection,1>
+        y_perceptible_size_projection;
+    sequence<PerceptibleProjection,1>
+        z_perceptible_size_projection;
+};
+
+// Corresponding MHEG datatype: Rt-Object-Number-Reference
+//=====
+enum RtObjectNumberReferenceTag { RT_OBJECT_NUMBER_TAG, RT_DYNAMIC_REFERENCE_TAG
+};
+union RtObjectNumberReference
+switch (RtObjectNumberReferenceTag) {
+    case RT_OBJECT_NUMBER_TAG:
+        long
+            rt_object_number;
+    case RT_DYNAMIC_REFERENCE_TAG:
+        RtDynamicReference
+            rt_dynamic_reference;
+};
+
+// Interface: RtObject Operation: bind
+// Interface: RtObject Operation: new
+// Corresponding MHEG datatype: Rt-Object-Reference
+//=====
+struct RtObjectReference {
+    MhObjectReference
+        model_object_reference;
+    RtObjectNumberReference
+        rt_object_number_reference;
+};
+
+// Corresponding MHEG datatype: Rt-Reference
+//=====
+enum RtReferenceTag { RT_REFERENCE_RT_OBJECT_REFERENCE_TAG,
+RT_REFERENCE_ALIAS_TAG,
+RT_REFERENCE_NULL_RT_OBJECT_TAG };
+union RtReference
+switch (RtReferenceTag) {
+    case RT_REFERENCE_RT_OBJECT_REFERENCE_TAG:
+        RtObjectReference
+            rt_object_reference;
+    case RT_REFERENCE_ALIAS_TAG:
+        Alias
+            alias;
+};
+
+```
+
+```
+
+// Corresponding MHEG datatype: Socket-Tail
+//=====
+struct SocketTail {
+    sequence<long>
+        indexes;
+    enum SocketTailTag { INDEX_TAG, SUB_SOCKET_REF_TAG } tag;
+    union SocketTail
+    switch (SocketTailTag){
+        case INDEX_TAG:
+            long
+                index;
+        case SUB_SOCKET_REF_TAG:
+            SubSocketReference
+                sub_socket_ref;
+    } end;
+};
+
+// Corresponding MHEG datatype: Indexed-Child-Socket
+//=====
+struct IndexedChildSocket {
+    long
+        index;
+    SocketTail
+        tail;
+};
+
+// Interface: Socket Operation: bind
+// Interface: Socket Operation: getIdentification
+// Corresponding MHEG datatype: Socket-Identification
+//=====
+struct SocketIdentification {
+    RtReference
+        rt_composite_reference;
+    SocketTail
+        socket_tail;
+};
+
+// Interface: Socket Operation: bind
+// Corresponding MHEG datatype: Socket-Reference
+//=====
+enum SocketReferenceTag { SOCKET_REFERENCE_SOCKET_IDENT_TAG,
+SOCKET_REFERENCE_ALIAS_TAG };
+union SocketReference
+switch (SocketReferenceTag){
+    case SOCKET_REFERENCE_SOCKET_IDENT_TAG:
+        SocketIdentification
+            socket_ident;
+    case SOCKET_REFERENCE_ALIAS_TAG:
+        Alias
+            alias;
+};
+
+// Corresponding MHEG datatype: Rt-Object-Socket-Reference
+//=====
+enum RtObjectSocketReferenceTag { RT_REFERENCE_TAG, SOCKET_REFERENCE_TAG };
+union RtObjectSocketReference
+switch (RtObjectSocketReferenceTag){
+    case RT_REFERENCE_TAG:
+        RtReference
+            rt_reference;
+    case SOCKET_REFERENCE_TAG:
+        SocketReference
+            socket_reference;
+};
+
+// Interface: RtCompositeOrStructuralSocket Operation:
+//   setScrollingListInteractionStyle
+// Interface: RtContentOrPresentableSocket Operation: setSliderInteractionStyle
+// Interface: RtContentOrPresentableSocket Operation:
+//   setEntryFieldInteractionStyle
+// Interface: Channel Operation: getAssignedPerceptibles
+// Corresponding MHEG datatype: Perceptible-Reference
+
+```
+
+```
+
+//=====
+enum PerceptibleReferenceTag { RT_COMPONENT_REFERENCE_TAG,
+RT_SOCKET_REFERENCE_TAG };
+union PerceptibleReference
+switch (PerceptibleReferenceTag){
+    case RT_COMPONENT_REFERENCE_TAG:
+        RtReference
+            rt_component_reference;
+    case RT_SOCKET_REFERENCE_TAG:
+        SocketReference
+            rt_socket_reference;
+};
+
+// Interface: RtCompositeOrStructuralSocket Operation:
+// setScrollingListInteractionStyle
+// Corresponding MHEG datatype: Separator
+//=====
+enum SeparatorTag { NO_TAG, YES_DEFAULT_TAG, SEPARATOR_PIECE_TAG };
+union Separator
+switch (SeparatorTag){
+    case SEPARATOR_PIECE_TAG:
+        PerceptibleReference
+            separator_piece;
+};
+
+// Interface: RtCompositeOrStructuralSocket Operation: setMenuInteractionStyle
+// Corresponding MHEG datatype: Association
+//=====
+struct Association {
+    sequence<SocketReference,1>
+        title;
+    sequence<Separator,1>
+        separator;
+    sequence<SocketReference,1>
+        submenu;
+    sequence<PresentationPersistence,1>
+        submenu_presentation_persistence;
+    sequence<Orientation,1>
+        submenu_orientation;
+};
+
+// Interface: RtSocket Operation: plug
+// Corresponding MHEG datatype: Plug-In
+//=====
+enum PlugInTag { PLUG_IN_RT_COMPONENT_REFERENCE_TAG,
+PLUG_IN_COMPONENT_REFERENCE_TAG,
+PLUG_IN_LABEL_TAG };
+union PlugIn
+switch (PlugInTag){
+    case PLUG_IN_RT_COMPONENT_REFERENCE_TAG:
+        RtObjectReference
+            rt_component_reference;
+    case PLUG_IN_COMPONENT_REFERENCE_TAG:
+        MhObjectReference
+            component_reference;
+    case PLUG_IN_LABEL_TAG:
+        GenericString
+            label;
+};
+
+// Interface: RtComponentOrSocket Operation: getVSEAPPosition
+// Corresponding MHEG datatype: none
+//=====
+enum ReferencePointTag { VSEAP_POSITION_ORIGIN_RGS_TAG,
+VSEAP_POSITION_ORIGIN_CGS_TAG,
+VSEAP_POSITION_SAME_RGS_COMPONENT_TAG, VSEAP_POSITION_SAME_CGS_COMPONENT_TAG,
+VSEAP_POSITION_SPECIFIED_POSITION_TAG };
+union ReferencePoint
+switch (ReferencePointTag){
+    case VSEAP_POSITION_SAME_RGS_COMPONENT_TAG:
+        RtObjectSocketReference
+            same_RGS_component;
+};
+
+```
+
+```
+
+    case VSEAP_POSITION_SAME_CGS_COMPONENT_TAG:
+        RtObjectSocketReference
+            same_CGS_component;
+    case VSEAP_POSITION_SPECIFIED_POSITION_TAG:
+        SpecifiedPosition
+            specified_position;
+};
+
+// Interface: RtScript Operation: setParameters
+// Corresponding MHEG datatype: Parameter
+//=====
+enum ParameterTag { GENERIC_VALUE_TAG, MH_OBJECT_REFERENCE_TAG };
+union Parameter
+switch (ParameterTag){
+    case GENERIC_VALUE_TAG:
+        GenericValue
+            generic_value;
+    case MH_OBJECT_REFERENCE_TAG:
+        MhObjectReference
+            mh_object_reference;
+};
+
+// Interface: RtObjectOrSocket Operation: setGlobalBehaviour
+// Corresponding MHEG datatype: Global-Behaviour
+//=====
+enum GlobalBehaviourTag { GLOBAL_BEHAVIOUR_RT_REFERENCE_TAG,
+GLOBAL_BEHAVIOUR_GENERIC_LIST_TAG,
+GLOBAL_BEHAVIOUR_UNSPECIFIED_TAG };
+union GlobalBehaviour
+switch (GlobalBehaviourTag){
+    case GLOBAL_BEHAVIOUR_RT_REFERENCE_TAG:
+        RtReference
+            rt_reference;
+    case GLOBAL_BEHAVIOUR_GENERIC_LIST_TAG:
+        GenericValue
+            generic_list;
+};
+
+// Interface: RtComponentOrSocket Operation: setVisibleSizesAdjustment
+// Corresponding MHEG datatype: Adjustment-PolicyADJUSTMENT-POLICY-
+//=====
+enum AdjustmentPolicyTag { ADJUSTMENT_POLICY_COMPONENT_REFERENCE_TAG,
+ADJUSTMENT_POLICY_SPECIFIED_TAG, ADJUSTMENT_POLICY_GREATEST_TAG,
+ADJUSTMENT_POLICY_SMALLEST_TAG
+};
+union AdjustmentPolicy
+switch (AdjustmentPolicyTag){
+    case ADJUSTMENT_POLICY_COMPONENT_REFERENCE_TAG:
+        RtObjectSocketReference
+            component_reference;
+    case ADJUSTMENT_POLICY_SPECIFIED_TAG:
+        SpecifiedSizes
+            specified;
+};
+
+// Interface: RtObject Operation: bind
+// Interface: RtObject Operation: new
+// Interface: RtObject Operation: getIdentifier
+// Corresponding MHEG datatype: none
+//=====
+struct RtObjectIdentifier {
+    MHEGIdentifier
+        model_object_id;
+    long
+        rt_object_number;
+};
+
+// Interface: RtGenericContentOrPresentableSocket Operation:
+// setButtonInteractionStyle
+// Corresponding MHEG datatype: Alternate-Presentation-State
+//=====
+struct AlternatePresentation {
+    PresentationState
+        presentation_state;
+};
+
+```
+
+```
+
+        PerceptibleReference
+            perceptible_target;
+};
+
+// Exceptions
+//=====
+exception InvalidTarget {
+    unsigned short period;
+};
+
+enum CompletionStatus { YES, NO};
+
+exception InvalidParameter {
+    CompletionStatus completion_status;
+    unsigned short period;
+};
+
+typedef long EntityIdentifier;
+
+exception AlreadyBound {
+    EntityIdentifier entity_identifier;
+};
+
+exception NotBound {};
+
+interface MHEGEngine {
+    void
+        initialiseEngine();
+    void
+        shutdownEngine();
+};
+
+interface NotificationManager {
+    sequence<unsigned short>
+        getReturnability();
+
+    void
+        getNotification(
+            in unsigned short
+                notification_number,
+            out sequence<GenericValue>
+                values,
+            out sequence<MhObjectReference>
+                objects)
+        raises(InvalidParameter);
+};
+
+interface EntityManager {
+    sequence<MHEGIdentifier>
+        getAvailableMhObjects();
+
+    sequence<RtObjectIdentifier>
+        getAvailableRtObjects();
+
+    sequence<ChannelIdentifier>
+        getAvailableChannels();
+
+    void
+        releaseAlias(
+            in string
+                alias)
+        raises(InvalidParameter);
+};
+
+interface Entity {
+    void
+        setAlias(
+            in string
+                alias)
+        raises(InvalidTarget);
+};
+
+```
+
+```
+
+        string
+            getAlias()
+        raises(InvalidTarget);
+};
+
+interface MhObject: Entity {
+    MHEGIdentifier
+        bind(
+            in MhObjectReference
+                mh_object_reference)
+        raises(AlreadyBound, InvalidTarget);
+
+    void
+        unbind()
+        raises(NotBound);
+
+    MHEGIdentifier
+        prepare(
+            in MhObjectReference
+                mh_object_reference)
+        raises(AlreadyBound, InvalidTarget);
+
+    void
+        destroy()
+        raises(NotBound, InvalidTarget);
+
+    PreparationStatusValue
+        getPreparationStatus()
+        raises(NotBound, InvalidTarget);
+
+    MHEGIdentifier
+        getIdentifier()
+        raises(NotBound);
+
+    void
+        kill();
+};
+
+interface MhAction: MhObject {
+    void
+        delay(
+            in unsigned short
+                nested_action_number,
+            in unsigned long
+                delay)
+        raises(InvalidTarget, InvalidParameter);
+};
+
+interface MhLink: MhObject {
+    void
+        abort()
+        raises(InvalidTarget);
+};
+
+interface MhModel: MhObject {};
+
+interface MhComponent: MhModel {};
+
+interface MhGenericContent: MhComponent {
+    void
+        copy(
+            in sequence<MhObjectReference>
+                copies)
+        raises(InvalidTarget, InvalidParameter);
+};
+
+```
+
+```
+
+interface MhContent: MhGenericContent {
+    void
+        setData(
+            in boolean
+                substitution_indicator,
+            in sequence<DataElement>
+                data_elements)
+        raises(InvalidTarget, InvalidParameter);
+    GenericValue
+        getData(
+            in sequence<long>
+                element_list_index)
+        raises(InvalidTarget, InvalidParameter);
+};
+
+interface MhMultiplexedContent: MhGenericContent {
+    void
+        setMultiplex(
+            in sequence<StreamIdentifier>
+                stream_list)
+        raises(InvalidTarget, InvalidParameter);
+    void
+        setDemultiplex(
+            in sequence<StreamIdentifier>
+                stream_list)
+        raises(InvalidTarget, InvalidParameter);
+};
+
+interface MhComposite: MhComponent {};
+interface MhScript: MhModel {};
+interface MhContainer: MhObject {};
+interface MhDescriptor: MhObject {};
+interface RtObjectOrSocket {
+    void
+        setGlobalBehaviour(
+            in GlobalBehaviour
+                global_behaviour)
+        raises(InvalidTarget, InvalidParameter);
+    GenericValue
+        getGlobalBehaviour()
+        raises(InvalidTarget);
+    void
+        run()
+        raises(InvalidTarget);
+    void
+        stop()
+        raises(InvalidTarget);
+};
+
+interface RtObject: Entity {
+    RtObjectIdentifier
+        bind(
+            in RtObjectReference
+                rt_object_reference)
+        raises(AlreadyBound, InvalidTarget);
+    void
+        unbind()
+        raises(NotBound);
+};
+
+```
+
+```
+
+RtObjectIdentifier
+    new(
+        in RtObjectReference
+            rt_object_reference)
+raises(AlreadyBound, InvalidTarget);
+
+void
+    delete()
+raises(NotBound, InvalidTarget);
+
+RtAvailabilityStatusValue
+    getAvailabilityStatus()
+raises(NotBound, InvalidTarget);
+
+RtObjectIdentifier
+    getIdentifier()
+raises(NotBound);
+
+void
+    kill();
+
+RunningStatusValue
+    getRunningStatus()
+raises(InvalidTarget);
+};
+
+interface Socket: Entity, RtObjectOrSocket {
+    SocketIdentification
+        bind(
+            in SocketReference
+                socket_reference)
+raises(AlreadyBound, InvalidTarget);
+
+void
+    unbind()
+raises(NotBound);
+
+SocketIdentification
+    getIdentifier();
+void
+    kill();
+
+void
+    plug(
+        in PlugIn
+            plug_in)
+raises(InvalidTarget);
+
+void
+    setVisibleDurationPosition(
+        in VisibleDurationPosition
+            visible_duration_position)
+raises(InvalidTarget, InvalidParameter);
+
+unsigned long
+    getVisibleDurationPosition()
+raises(InvalidTarget);
+};
+
+interface RtScript: RtObject {
+    void
+        setParameters(
+            in sequence<Parameter>
+                parameters)
+raises(InvalidTarget);
+
+TerminationStatusValue
+    getTerminationStatus()
+raises(InvalidTarget);
+};
+
+interface RtComponentOrSocket {
+
+```
+
+```
+
+void
+    setRGS (
+        in ChannelIdentifier
+            channel_identifier)
+raises(InvalidTarget);
+
+RGSValue
+    getRGS ()
+raises(InvalidTarget);
+
+void
+    setOpacity(
+        in unsigned short
+            opacity_rate,
+        in unsigned long
+            transition_duration)
+raises(InvalidTarget);
+
+void
+    setPresentationPriority(
+        in PresentationPriority
+            presentation_priority,
+        in unsigned long
+            transition_duration)
+raises(InvalidTarget, InvalidParameter);
+
+unsigned short
+    getOpacity()
+raises(InvalidTarget);
+
+unsigned short
+    getEffectiveOpacity()
+raises(InvalidTarget);
+
+unsigned short
+    getPresentationPriority()
+raises(InvalidTarget);
+
+void
+    setVisibleDuration(
+        in TemporalPosition
+            initial_temporal_position,
+        in TemporalPosition
+            terminal_temporal_position)
+raises(InvalidTarget, InvalidParameter);
+
+void
+    setTemporalTermination(
+        in TemporalTermination
+            temporal_termination)
+raises(InvalidTarget);
+
+void
+    setCurrentTemporalPosition(
+        in TemporalPosition
+            temporal_position)
+raises(InvalidTarget, InvalidParameter);
+
+void
+    setSpeed(
+        in Speed
+            the_speed,
+        in unsigned long
+            transition_duration)
+raises(InvalidTarget, InvalidParameter);
+
+void
+    setTimestones(
+        in sequence<Timestone>
+            timestones)
+raises(InvalidTarget, InvalidParameter);
+
+unsigned long
+    getInitialTemporalPosition()
+raises(InvalidTarget);
+
+```
+
+```
+
+unsigned long
+    getTerminalTemporalPosition()
+raises(InvalidTarget);
+
+unsigned long
+    getVDLength(
+        in GTIndicator
+            gt_indicator)
+raises(InvalidTarget);
+
+TemporalTermination
+    getTemporalTermination()
+raises(InvalidTarget);
+
+unsigned long
+    getCurrentTemporalPosition()
+raises(InvalidTarget);
+
+short
+    getSpeedRate()
+raises(InvalidTarget);
+
+unsigned long
+    getOGTR()
+raises(InvalidTarget);
+
+short
+    getEffectiveSpeedRate()
+raises(InvalidTarget);
+
+unsigned long
+    getEffectiveOGTR()
+raises(InvalidTarget);
+
+unsigned short
+    getTimestoneStatus()
+raises(InvalidTarget);
+
+void
+    setPerceptibleSizeProjection(
+        in PerceptibleSizeProjection
+            perceptible_size_projection,
+        in unsigned long
+            transition_duration)
+raises(InvalidTarget, InvalidParameter);
+
+void
+    setAspectRatio(
+        in AspectRatio
+            preserved)
+raises(InvalidTarget);
+
+void
+    setVisibleSize(
+        in VSGS
+            the_vsgs,
+        in VS
+            the_vs,
+        in unsigned long
+            transition_duration)
+raises(InvalidTarget, InvalidParameter);
+
+void
+    setVisibleSizesAdjustment(
+        in sequence<AdjustmentAxis>
+            set_of_axes,
+        in AdjustmentPolicy
+            adjustment_policy,
+        in unsigned long
+            transition_duration)
+raises(InvalidTarget);
+
+void
+    setBox(
+        in BoxConstants
+            box)
+raises(InvalidTarget);
+
+```
+
+```
+
+void
+    setDefaultBackground(
+        in unsigned short
+            background,
+        in unsigned long
+            transition_duration)
+raises(InvalidTarget, InvalidParameter);
+
+void
+    setAttachmentPoint(
+        in AttachmentPointType
+            type,
+        in AttachmentPoint
+            positions)
+raises(InvalidTarget, InvalidParameter);
+
+void
+    setAttachmentPointPosition(
+        in AttachmentPointType
+            type,
+        in ReferenceType
+            vseap_reference_point,
+        in Lengths
+            the_lengths,
+        in unsigned long
+            transition_duration)
+raises(InvalidTarget, InvalidParameter);
+
+void
+    setVisibleSizesAlignment(
+        in SizeBorder
+            size_border,
+        in long
+            interval,
+        in unsigned long
+            transition_duration)
+raises(InvalidTarget);
+
+void
+    setMovingAbility(
+        in UserControls
+            moving_ability)
+raises(InvalidTarget);
+
+void
+    setResizingAbility(
+        in UserControls
+            resizing_ability)
+raises(InvalidTarget);
+
+void
+    setScalingAbility(
+        in UserControls
+            scaling_ability)
+raises(InvalidTarget);
+
+void
+    setScrollingAbility(
+        in UserControls
+            scrolling_ability)
+raises(InvalidTarget);
+
+unsigned short
+    getGSR()
+raises(InvalidTarget);
+
+SpecifiedPosition
+    getPS(
+        in GSIndicator
+            gs)
+raises(InvalidTarget);
+
+AspectRatio
+    getAspectRatio()
+raises(InvalidTarget);
+
+```
+
+```
+
+SpecifiedPosition
+    getPSAP(
+        in PointType
+            point_type)
+raises(InvalidTarget);
+
+VSGS
+    getVSGS()
+raises(InvalidTarget);
+
+SpecifiedPosition
+    getVS()
+raises(InvalidTarget);
+
+BoxConstants
+    getBox()
+raises(InvalidTarget);
+
+unsigned short
+    getDefaultBackground()
+raises(InvalidTarget);
+
+SpecifiedPosition
+    getVSIAP(
+        in PointType
+            point_type)
+raises(InvalidTarget);
+
+SpecifiedPosition
+    getVSIAPPosition()
+raises(InvalidTarget);
+
+SpecifiedPosition
+    getVSEAP(
+        in PointType
+            point_type)
+raises(InvalidTarget);
+
+SpecifiedPosition
+    getVSEAPPosition(
+        in ReferencePoint
+            reference_point)
+raises(InvalidTarget);
+
+UserControls
+    getMovingAbility()
+raises(InvalidTarget);
+
+UserControls
+    getResizingAbility()
+raises(InvalidTarget);
+
+UserControls
+    getScalingAbility()
+raises(InvalidTarget);
+
+UserControls
+    getScrollingAbility()
+raises(InvalidTarget);
+
+void
+    setSelectability(
+        in unsigned short
+            min_number_of_selections,
+        in unsigned short
+            max_number_of_selections)
+raises(InvalidTarget, InvalidParameter);
+
+void
+    setSelectionStatus(
+        in SelectionStatusValue
+            selection_state)
+raises(InvalidTarget);
+
+void
+    setSelectionPresentationEffectResponsibility(
+        in Responsibility
+            the_responsibility)
+
+```
+
+```
+
+raises(InvalidTarget);
+
+void
+    getSelectability(
+        out unsigned short
+            min_number_of_selections,
+        out unsigned short
+            max_number_of_selections)
+raises(InvalidTarget);
+
+EffectiveSelectability
+    getEffectiveSelectability()
+raises(InvalidTarget);
+
+SelectionStatusValue
+    getSelectionStatus()
+raises(InvalidTarget);
+
+SelectionModeValue
+    getSelectionMode()
+raises(InvalidTarget);
+
+Responsibility
+    getSelectionPresentationEffectResponsibility()
+raises(InvalidTarget);
+
+void
+    setModifiability(
+        in unsigned short
+            min_number_of_modifications,
+        in unsigned short
+            max_number_of_modifications)
+raises(InvalidTarget, InvalidParameter);
+
+void
+    setModificationStatus(
+        in ModificationStatusValue
+            modification_state)
+raises(InvalidTarget);
+
+void
+    setModificationPresentationEffectResponsibility(
+        in Responsibility
+            the_responsibility)
+raises(InvalidTarget);
+
+void
+    getModifiability(
+        out unsigned short
+            min_numbers_of_modifications,
+        out unsigned short
+            max_numbers_of_modifications)
+raises(InvalidTarget);
+
+EffectiveModifiability
+    getEffectiveModifiability()
+raises(InvalidTarget);
+
+ModificationStatusValue
+    getModificationStatus()
+raises(InvalidTarget);
+
+ModificationModeValue
+    getModificationMode()
+raises(InvalidTarget);
+
+Responsibility
+    getModificationPresentationEffectResponsibility()
+raises(InvalidTarget);
+
+void
+    setNoInteractionStyle()
+raises(InvalidTarget);
+};
+
+```
+
+```
+
+interface RtComponent: RtComponentOrSocket, RtObject {};
+interface RtCompositeOrStructuralSocket {
+    void
+        setResizingStrategy(
+            in ResizingStrategy
+                resizing_strategy)
+        raises(InvalidTarget);
+    ResizingStrategy
+        getResizingStrategy()
+        raises(InvalidTarget);
+    void
+        setAudibleCompositionEffect(
+            in unsigned_short
+                audible_effect,
+            in unsigned_long
+                transition_duration)
+        raises(InvalidTarget);
+    unsigned_short
+        getAudibleCompositionEffect()
+        raises(InvalidTarget);
+    unsigned_short
+        getNumberOfSelectedSockets()
+        raises(InvalidTarget);
+    unsigned_short
+        getNumberOfModifiedSockets()
+        raises(InvalidTarget);
+    void
+        setMenuInteractionStyle(
+            in Orientation
+                upper_menu_orientation,
+            in sequence <Association>
+                list_of_associations)
+        raises(InvalidTarget, InvalidParameter);
+    void
+        setScrollingListInteractionStyle(
+            in PerceptibleReference
+                background,
+            in unsigned_short
+                visible_items_number,
+            in SocketTail
+                first_item,
+            in Separator
+                the_separator,
+            in Orientation
+                the_orientation,
+            in SliderSide
+                slider_side,
+            in PerceptibleReference
+                slider,
+            in PerceptibleReference
+                slider_cursor,
+            in PerceptibleReference
+                slider_background,
+            in long
+                slider_min_value,
+            in long
+                slider_max_value)
+        raises(InvalidTarget, InvalidParameter);
+};
+interface RtComposite: RtCompositeOrStructuralSocket, RtComponent {};
+interface StructuralSocket: RtCompositeOrStructuralSocket, Socket {};
+interface RtGenericContentOrPresentableSocket {
+
+```
+
+```
+
+void
+    setAudibleVolume(
+        in AudibleVolume
+            audible_volume,
+        in unsigned_long
+            transition_duration)
+raises(InvalidTarget, InvalidParameter);
+
+unsigned long
+    getInitialOriginalAudibleVolume()
+raises(InvalidTarget);
+
+unsigned long
+    getCurrentOriginalAudibleVolume()
+raises(InvalidTarget);
+
+unsigned long
+    getEffectiveOriginalAudibleVolume()
+raises(InvalidTarget);
+
+unsigned long
+    getPerceptibleAudibleVolume()
+raises(InvalidTarget);
+
+void
+    setButtonInteractionStyle(
+        in PresentationState
+            initial_state,
+        in AlternatePresentation
+            alternate_presentation_1,
+        in AlternatePresentation
+            alternate_presentation_2,
+        in AlternatePresentation
+            alternate_presentation_3)
+raises(InvalidTarget, InvalidParameter);
+};
+
+interface RtGenericContent: RtGenericContentOrPresentableSocket, RtComponent {};
+
+interface GenericPresentableSocket: RtGenericContentOrPresentableSocket, Socket
+{};
+
+interface RtContentOrPresentableSocket {
+
+    void
+        setSliderInteractionStyle(
+            in PerceptibleReference
+                cursor,
+            in PerceptibleReference
+                background,
+            in Orientation
+                the_orientation,
+            in short
+                min_value,
+            in short
+                max_value)
+raises(InvalidTarget, InvalidParameter);
+
+    void
+        setEntryFieldInteractionStyle(
+            in EchoStyle
+                echo_style,
+            in PerceptibleReference
+                background)
+raises(InvalidTarget, InvalidParameter);
+
+};
+
+interface RtContent: RtContentOrPresentableSocket, RtGenericContent {};
+
+interface PresentableSocket: RtContentOrPresentableSocket,
+GenericPresentableSocket {};
+
+interface RtMultiplexedContentOrPresentableSocket {
+
+```
+
+```
+
+void
+    setStreamChoice(
+        in StreamIdentifier
+            stream_identifier)
+raises(InvalidTarget, InvalidParameter);
+
+StreamValue
+    getStreamChosen()
+raises(InvalidTarget);
+};
+
+interface RtMultiplexedContent: RtMultiplexedContentOrPresentableSocket,
+RtGenericContent {};
+
+interface MultiplexedPresentableSocket: RtMultiplexedContentOrPresentableSocket,
+GenericPresentableSocket {};
+
+interface Channel: Entity {
+    ChannelIdentifier
+        bind(
+            in ChannelReference
+                channel_reference)
+raises(AlreadyBound, InvalidTarget);
+
+void
+    unbind()
+raises(NotBound);
+
+ChannelIdentifier
+    new(
+        in ChannelReference
+            channel_reference,
+        in OriginalDefDeclaration
+            original_definition_declaration)
+raises(AlreadyBound, InvalidTarget);
+
+void
+    delete()
+raises(NotBound, InvalidTarget);
+
+ChannelStatusValue
+    getAvailability()
+raises(NotBound, InvalidTarget);
+
+ChannelIdentifier
+    getIdentifier()
+raises(NotBound);
+
+void
+    kill();
+
+void
+    setPerceptability(
+        in ChannelPerceptabilityValue
+            channel_perceptability)
+raises(InvalidTarget);
+
+ChannelPerceptabilityValue
+    getPerceptability()
+raises(InvalidTarget);
+
+sequence<PerceptibleReference>
+    getAssignedPerceptibles()
+raises(InvalidTarget);
+};
+
+module x {
+interface EvaluatedValue;
+
+// Corresponding MHEG datatype: RGS-Constants
+//=====
+enum RGSConstants {
+    NULL_CHANNEL,
+    PRGS_
+};
+
+```
+
+```
+
+// Corresponding MHEG datatype: Stream-Chosen
+//=====
+enum StreamChosen {
+    NO_STREAM_CHOSEN
+};
+
+// Corresponding MHEG datatype: Selection-Mode-Constants
+//=====
+enum SelectionModeConstants {
+    NO_SELECTION,
+    MHEG_ACTION,
+    USING_APPLICATION_ACTION
+};
+
+// Corresponding MHEG datatype: Modification-Mode-Constants
+//=====
+enum ModificationModeConstants {
+    MODIFICATION_MODE_CONSTANTS_NO_MODIFICATION,
+    MODIFICATION_MODE_CONSTANTS_MHEG_ACTION,
+    MODIFICATION_MODE_CONSTANTS_USING_APPLICATION_ACTION,
+    MODIFICATION_MODE_CONSTANTS_CHILD
+};
+
+// Corresponding MHEG datatype: Comparison-Value-Constant
+//=====
+enum ComparisonValueConstantTag { TEMPORAL_TERMINATION_TAG,
+RESIZING_STRATEGY_TAG, VSGS_TAG, RESPONSIBILITY_TAG,
+PREPARATION_STATUS_VALUE_TAG, RT_AVAILABILITY_STATUS_VALUE_TAG,
+RUNNING_STATUS_VALUE_TAG, TERMINATION_STATUS_VALUE_TAG, RGS_CONSTANTS_TAG,
+USER_CONTROLS_TAG, ASPECT_RATIO_TAG, BOX_CONSTANTS_TAG, STREAM_CHOSEN_TAG,
+EFFECTIVE_SELECTABILITY_TAG, SELECTION_STATUS_VALUE_TAG,
+SELECTION_MODE_CONSTANTS_TAG, EFFECTIVE_MODIFIABILITY_TAG,
+MODIFICATION_STATUS_VALUE_TAG, MODIFICATION_MODE_CONSTANTS_TAG,
+CHANNEL_STATUS_VALUE_TAG, CHANNEL_PERCEPTABILITY_VALUES_TAG };
+union ComparisonValueConstant
+switch (ComparisonValueConstantTag){
+    case TEMPORAL_TERMINATION_TAG:
+        TemporalTermination
+            temporal_termination;
+    case RESIZING_STRATEGY_TAG:
+        ResizingStrategy
+            resizing_strategy;
+    case VSGS_TAG:
+        VSGS
+            vsgs;
+    case RESPONSIBILITY_TAG:
+        Responsibility
+            responsibility;
+    case PREPARATION_STATUS_VALUE_TAG:
+        PreparationStatusValue
+            preparation_status_value;
+    case RT_AVAILABILITY_STATUS_VALUE_TAG:
+        RtAvailabilityStatusValue
+            rt_availability_status_value;
+    case RUNNING_STATUS_VALUE_TAG:
+        RunningStatusValue
+            running_status_value;
+    case TERMINATION_STATUS_VALUE_TAG:
+        TerminationStatusValue
+            termination_status_value;
+    case RGS_CONSTANTS_TAG:
+        RGSConstants
+            rgs_constants;
+    case USER_CONTROLS_TAG:
+        UserControls
+            user_controls;
+    case ASPECT_RATIO_TAG:
+        AspectRatio
+            aspect_ratio;
+    case BOX_CONSTANTS_TAG:
+        BoxConstants
+            box_constants;
+
+```
+
+```
+
+case STREAM_CHOSEN_TAG:
+    StreamChosen
+        stream_chosen;
+case EFFECTIVE_SELECTABILITY_TAG:
+    EffectiveSelectability
+        effective_selectability;
+case SELECTION_STATUS_VALUE_TAG:
+    SelectionStatusValue
+        selection_status_value;
+case SELECTION_MODE_CONSTANTS_TAG:
+    SelectionModeConstants
+        selection_mode_constants;
+case EFFECTIVE_MODIFIABILITY_TAG:
+    EffectiveModifiability
+        effective_modifiability;
+case MODIFICATION_STATUS_VALUE_TAG:
+    ModificationStatusValue
+        modification_status_value;
+case MODIFICATION_MODE_CONSTANTS_TAG:
+    ModificationModeConstants
+        modification_mode_constants;
+case CHANNEL_STATUS_VALUE_TAG:
+    ChannelStatusValue
+        channel_status_value;
+case CHANNEL_PERCEPTABILITY_VALUES_TAG:
+    ChannelPerceptabilityValue
+        channel_perceptability_value;
+};
+
+// Corresponding MHEG datatype: Data-Reference
+//=====
+enum DataReferenceTag { EXTERNAL_IDENTIFIER_TAG, ALIAS_TAG };
+union DataReference
+switch (DataReferenceTag){
+    case EXTERNAL_IDENTIFIER_TAG:
+        ExternalIdentifier
+            external_identifier;
+    case ALIAS_TAG:
+        Alias
+            alias;
+};
+
+// Corresponding MHEG datatype: Reference
+//=====
+enum ReferenceTag { MHEG_OBJECT_REF_TAG, RT_OBJECT_REF_TAG, CHANNEL_ID_TAG,
+SOCKET_IDENT_REF_TAG, NULL_REF_TAG };
+union Reference
+switch (ReferenceTag){
+    case MHEG_OBJECT_REF_TAG:
+        MhObjectReference
+            mh_object_ref;
+    case RT_OBJECT_REF_TAG:
+        RtObjectReference
+            rt_object_ref;
+    case CHANNEL_ID_TAG:
+        ChannelIdentifier
+            channel_id;
+    case SOCKET_IDENT_REF_TAG:
+        SocketIdentification
+            socket_ident_ref;
+};
+
+// Corresponding MHEG datatype: Generic-Reference
+//=====
+enum GenericReferenceTag { REFERENCE_TAG, EVALUATED_VALUE_TAG, UNSPECIFIED_TAG };
+union GenericReference
+switch (GenericReferenceTag){
+    case REFERENCE_TAG:
+        Reference
+            reference;
+    case EVALUATED_VALUE_TAG:
+        EvaluatedValue
+            evaluated_value;
+};
+
+```
+
+```
+
+// Corresponding MHEG datatype: Macro-Def-Id
+//=====
+enum MacroDefIdTag { STRING_FIELD_TAG, NUMERIC_TAG };
+union MacroDefId
+switch (MacroDefIdTag){
+    case STRING_FIELD_TAG:
+        string
+        string_field;
+    case NUMERIC_TAG:
+        long
+        numeric;
+};
+
+// Corresponding MHEG datatype: Target-Macro
+//=====
+struct TargetMacro {
+    MacroDefId
+    macro_def_id;
+    sequence<GenericReference,1>
+    generic_reference;
+};
+
+// Corresponding MHEG datatype: Target-Parameter
+//=====
+enum TargetParameterTag { GENERIC_REFERENCE_TAG, TARGET_MACRO_TAG };
+union TargetParameter
+switch (TargetParameterTag){
+    case GENERIC_REFERENCE_TAG:
+        GenericReference
+        generic_reference;
+    case TARGET_MACRO_TAG:
+        TargetMacro
+        target_macro;
+};
+
+// Corresponding MHEG datatype: Targets-Parameter
+//=====
+typedef sequence<TargetParameter> TargetsParameter;
+
+// Corresponding MHEG datatype: Mh-Target-Macro
+//=====
+struct MhTargetMacro {
+    MacroDefId
+    macro_def_id;
+    sequence<MhObjectReference,1>
+    mh_object_reference;
+};
+
+// Corresponding MHEG datatype: Mh-Target-Parameter
+//=====
+enum MhTargetParameterTag { MH_REFERENCE_TAG, EVALUATED_TARGET_TAG,
+MH_TARGET_MACRO_TAG };
+union MhTargetParameter
+switch (MhTargetParameterTag){
+    case MH_REFERENCE_TAG:
+        MhObjectReference
+        mh_reference;
+    case EVALUATED_TARGET_TAG:
+        EvaluatedValue
+        evaluated_target;
+    case MH_TARGET_MACRO_TAG:
+        MhTargetMacro
+        mh_target_macro;
+};
+
+// Corresponding MHEG datatype: Mh-Targets-Parameter
+//=====
+typedef sequence<MhTargetParameter> MhTargetsParameter;
+
+```
+
+```
+
+// Corresponding MHEG datatype: Rt-Target-Macro
+//=====
+struct RtTargetMacro {
+    MacroDefId
+        macro_def_id;
+    sequence<RtReference,1>
+        rt_reference;
+};
+
+// Corresponding MHEG datatype: Rt-Target-Parameter
+//=====
+enum RtTargetParameterTag { RT_TARGET_PARAMETER_RT_REFERENCE_TAG,
+RT_TARGET_PARAMETER_EVALUATED_TARGET_TAG, RT_TARGET_PARAMETER_RT_TARGET_MACRO_TAG
+};
+union RtTargetParameter
+switch (RtTargetParameterTag){
+    case RT_TARGET_PARAMETER_RT_REFERENCE_TAG:
+        RtReference
+            rt_reference;
+    case RT_TARGET_PARAMETER_EVALUATED_TARGET_TAG:
+        EvaluatedValue
+            evaluated_target;
+    case RT_TARGET_PARAMETER_RT_TARGET_MACRO_TAG:
+        RtTargetMacro
+            rt_target_macro;
+};
+
+// Corresponding MHEG datatype: Rt-Targets-Parameter
+//=====
+typedef sequence<RtTargetParameter> RtTargetsParameter;
+
+// Corresponding MHEG datatype: Socket-Target-Macro
+//=====
+struct SocketTargetMacro {
+    MacroDefId
+        macro_def_id;
+    sequence<SocketReference,1>
+        socket_reference;
+};
+
+// Corresponding MHEG datatype: Socket-Target-Parameter
+//=====
+enum SocketTargetParameterTag { SOCKET_TARGET_PARAMETER_SOCKET_REFERENCE_TAG,
+SOCKET_TARGET_PARAMETER_EVALUATED_TARGET_TAG,
+SOCKET_TARGET_PARAMETER_SOCKET_TARGET_MACRO_TAG };
+union SocketTargetParameter
+switch (SocketTargetParameterTag){
+    case SOCKET_TARGET_PARAMETER_SOCKET_REFERENCE_TAG:
+        SocketReference
+            socket_reference;
+    case SOCKET_TARGET_PARAMETER_EVALUATED_TARGET_TAG:
+        EvaluatedValue
+            evaluated_target;
+    case SOCKET_TARGET_PARAMETER_SOCKET_TARGET_MACRO_TAG:
+        SocketTargetMacro
+            socket_target_macro;
+};
+
+// Corresponding MHEG datatype: Socket-Targets-Parameter
+//=====
+typedef sequence<SocketTargetParameter> SocketTargetsParameter;
+
+// Corresponding MHEG datatype: Rt-Socket-Target-Macro
+//=====
+struct RtSocketTargetMacro {
+    MacroDefId
+        macro_def_id;
+    sequence<RtObjectSocketReference,1>
+        rt_socket_reference;
+};
+
+```
+
+```
+
+// Corresponding MHEG datatype: Rt-Socket-Target-Parameter
+//=====
+enum RtSocketTargetParameterTag {
+RT_SOCKET_TARGET_PARAMETER_RT_SOCKET_REFERENCE_TAG,
+RT_SOCKET_TARGET_PARAMETER_EVALUATED_TARGET_TAG,
+RT_SOCKET_TARGET_PARAMETER_RT_SOCKET_TARGET_MACRO_TAG };
+union RtSocketTargetParameter
+switch (RtSocketTargetParameterTag){
+    case RT_SOCKET_TARGET_PARAMETER_RT_SOCKET_REFERENCE_TAG:
+        RtObjectSocketReference
+            rt_socket_reference;
+    case RT_SOCKET_TARGET_PARAMETER_EVALUATED_TARGET_TAG:
+        EvaluatedValue
+            evaluated_target;
+    case RT_SOCKET_TARGET_PARAMETER_RT_SOCKET_TARGET_MACRO_TAG:
+        RtSocketTargetMacro
+            rt_socket_target_macro;
+};
+
+// Corresponding MHEG datatype: Rt-Socket-Targets-Parameter
+//=====
+typedef sequence<RtSocketTargetParameter> RtSocketTargetsParameter;
+
+// Corresponding MHEG datatype: Channel-Target-Macro
+//=====
+struct ChannelTargetMacro {
+    MacroDefId
+        macro_def_id;
+    sequence<ChannelReference,1>
+        channel_reference;
+};
+
+// Corresponding MHEG datatype: Channel-Target-Parameter
+//=====
+enum ChannelTargetParameterTag { CHANNEL_TARGET_PARAMETER_CHANNEL_REFERENCE_TAG,
+CHANNEL_TARGET_PARAMETER_EVALUATED_TARGET_TAG,
+CHANNEL_TARGET_PARAMETER_CHANNEL_TARGET_MACRO_TAG };
+union ChannelTargetParameter
+switch (ChannelTargetParameterTag){
+    case CHANNEL_TARGET_PARAMETER_CHANNEL_REFERENCE_TAG:
+        ChannelReference
+            channel_reference;
+    case CHANNEL_TARGET_PARAMETER_EVALUATED_TARGET_TAG:
+        EvaluatedValue
+            evaluated_target;
+    case CHANNEL_TARGET_PARAMETER_CHANNEL_TARGET_MACRO_TAG:
+        ChannelTargetMacro
+            channel_target_macro;
+};
+
+// Corresponding MHEG datatype: Channel-Targets-Parameter
+//=====
+typedef sequence<ChannelTargetParameter> ChannelTargetsParameter;
+
+// Corresponding MHEG datatype: Element-List-Index-Macro
+//=====
+struct ElementListIndexMacro {
+    MacroDefId
+        macro_def_id;
+    sequence<sequence<GenericNumeric>,1>
+        generic_numeric_list;
+};
+
+// Corresponding MHEG datatype: Element-List-Index-Parameter
+//=====
+enum ElementListIndexParameterTag { GENERIC_NUMERIC_LIST_TAG,
+ELEMENT_LIST_INDEX_MACRO_TAG };
+union ElementListIndexParameter
+switch (ElementListIndexParameterTag){
+    case GENERIC_NUMERIC_LIST_TAG:
+        sequence<GenericNumeric>
+            generic_numeric_list;
+};
+
+```
+
+```
+
+        case ELEMENT_LIST_INDEX_MACRO_TAG:
+            ElementListIndexMacro
+                element_list_index_macro;
+};
+
+// Corresponding MHEG datatype: Get-Data
+//=====
+struct GetData {
+    MhTargetParameter
+        content_target_parameter;
+    sequence<ElementListIndexParameter,1>
+        element_list_index_parameter;
+};
+
+// Corresponding MHEG datatype: GT-Indicator-Macro
+//=====
+struct GTIndicatorMacro {
+    MacroDefId
+        macro_def_id;
+    sequence<GTIndicator,1>
+        gt_indicator;
+};
+
+// Corresponding MHEG datatype: GT-Indicator-Parameter
+//=====
+enum GTIndicatorParameterTag { GT_INDICATOR_TAG, GT_INDICATOR_MACRO_TAG };
+union GTIndicatorParameter
+switch (GTIndicatorParameterTag){
+    case GT_INDICATOR_TAG:
+        GTIndicator
+            gt_indicator;
+    case GT_INDICATOR_MACRO_TAG:
+        GTIndicatorMacro
+            gt_indicator_macro;
+};
+
+// Corresponding MHEG datatype: Get-PD
+//=====
+struct GetPD {
+    RtSocketTargetParameter
+        target;
+    sequence<GTIndicatorParameter,1>
+        gt_indicator;
+};
+
+// Corresponding MHEG datatype: Get-VD-Length
+//=====
+struct GetVDLength {
+    RtSocketTargetParameter
+        target;
+    GTIndicatorParameter
+        gt_indicator;
+};
+
+// Corresponding MHEG datatype: GS-Indicator-Macro
+//=====
+struct GSIndicatorMacro {
+    MacroDefId
+        macro_def_id;
+    sequence<GSIndicator,1>
+        gs_indicator;
+};
+
+// Corresponding MHEG datatype: GS-Indicator-Parameter
+//=====
+enum GSIndicatorParameterTag { GS_INDICATOR_TAG, GS_INDICATOR_MACRO_TAG };
+union GSIndicatorParameter
+switch (GSIndicatorParameterTag){
+    case GS_INDICATOR_TAG:
+        GSIndicator
+            gs_indicator;
+    case GS_INDICATOR_MACRO_TAG:
+        GSIndicatorMacro
+            gs_indicator_macro;
+};
+
+```
+
+```
+
+// Corresponding MHEG datatype: Perceptible-Size-Parameter
+//=====
+struct PerceptibleSizeParameter {
+    RtSocketTargetParameter
+        target;
+    sequence<GSIndicatorParameter,1>
+        generic_space;
+};
+
+// Corresponding MHEG datatype: Point-Type-Macro
+//=====
+struct PointTypeMacro {
+    MacroDefId
+        macro_def_id;
+    sequence<PointType,1>
+        point_type;
+};
+
+// Corresponding MHEG datatype: Point-Type-Parameter
+//=====
+enum PointTypeParameterTag { POINT_TYPE_TAG, POINT_TYPE_MACRO_TAG };
+union PointTypeParameter
+switch (PointTypeParameterTag){
+    case POINT_TYPE_TAG:
+        PointType
+            point_type;
+    case POINT_TYPE_MACRO_TAG:
+        PointTypeMacro
+            point_type_macro;
+};
+
+// Corresponding MHEG datatype: AP-Parameter
+//=====
+struct APParameter {
+    RtSocketTargetParameter
+        target;
+    sequence<PointTypeParameter,1>
+        type;
+};
+
+// Corresponding MHEG datatype: Reference-Point-Macro
+//=====
+struct ReferencePointMacro {
+    MacroDefId
+        macro_def_id;
+    sequence<ReferencePoint,1>
+        reference_point;
+};
+
+// Corresponding MHEG datatype: Reference-Point-Parameter
+//=====
+enum ReferencePointParameterTag { REFERENCE_POINT_TAG, REFERENCE_POINT_MACRO_TAG };
+union ReferencePointParameter
+switch (ReferencePointParameterTag){
+    case REFERENCE_POINT_TAG:
+        ReferencePoint
+            reference_point;
+    case REFERENCE_POINT_MACRO_TAG:
+        ReferencePointMacro
+            reference_point_macro;
+};
+
+```
+
+```
+
+// Corresponding MHEG datatype: VSEAP-Position-Parameter
+//=====
+struct VSEAPPositionParameter {
+    RtSocketTargetParameter
+        target;
+    sequence<ReferencePointParameter,1>
+        reference_point;
+};
+
+// Corresponding MHEG datatype: Generic-Value
+//=====
+enum GenericValueTag { GENERIC_VALUE_BOOLEAN_FIELD_TAG,
+GENERIC_VALUE_NUMERIC_TAG, GENERIC_VALUE_STRING_FIELD_TAG,
+GENERIC_VALUE_GENERIC_LIST_TAG, GENERIC_VALUE_REFERENCE_TAG,
+GENERIC_VALUE_UNSPECIFIED_TAG, GENERIC_VALUE_EVALUATED_VALUE_TAG };
+union GenericValue
+switch (GenericValueTag){
+    case GENERIC_VALUE_BOOLEAN_FIELD_TAG:
+        boolean
+            boolean_field;
+    case GENERIC_VALUE_NUMERIC_TAG:
+        long
+            numeric;
+    case GENERIC_VALUE_STRING_FIELD_TAG:
+        string
+            string_field;
+    case GENERIC_VALUE_GENERIC_LIST_TAG:
+        sequence<GenericValue>
+            generic_list;
+    case GENERIC_VALUE_REFERENCE_TAG:
+        Reference
+            reference;
+    case GENERIC_VALUE_EVALUATED_VALUE_TAG:
+        EvaluatedValue
+            evaluated_value;
+};
+
+// Corresponding MHEG datatype: Generic-Boolean
+//=====
+enum GenericBooleanTag { GENERIC_BOOLEAN_CONSTANT_TAG,
+GENERIC_BOOLEAN_EVALUATED_VALUE_TAG, GENERIC_BOOLEAN_UNSPECIFIED_TAG };
+union GenericBoolean
+switch (GenericBooleanTag){
+    case GENERIC_BOOLEAN_CONSTANT_TAG:
+        boolean
+            constant;
+    case GENERIC_BOOLEAN_EVALUATED_VALUE_TAG:
+        EvaluatedValue
+            evaluated_value;
+};
+
+// Corresponding MHEG datatype: Generic-Numeric
+//=====
+enum GenericNumericTag { GENERIC_NUMERIC_CONSTANT_TAG,
+GENERIC_NUMERIC_EVALUATED_VALUE_TAG, GENERIC_NUMERIC_UNSPECIFIED_TAG };
+union GenericNumeric
+switch (GenericNumericTag){
+    case GENERIC_NUMERIC_CONSTANT_TAG:
+        long
+            constant;
+    case GENERIC_NUMERIC_EVALUATED_VALUE_TAG:
+        EvaluatedValue
+            evaluated_value;
+};
+
+// Corresponding MHEG datatype: Generic-String
+//=====
+enum GenericStringTag { GENERIC_STRING_CONSTANT_TAG,
+GENERIC_STRING_EVALUATED_VALUE_TAG, GENERIC_STRING_UNSPECIFIED_TAG };
+union GenericString
+switch (GenericStringTag){
+
+```
+
+```
+
+    case GENERIC_STRING_CONSTANT_TAG:
+        string
+            constant;
+    case GENERIC_STRING_EVALUATED_VALUE_TAG:
+        EvaluatedValue
+            evaluated_value;
+};
+
+// Corresponding MHEG datatype: Value-Macro
+//=====
+struct ValueMacro {
+    MacroDefId
+        macro_def_id;
+    sequence<GenericValue,1>
+        generic_value;
+};
+
+// Corresponding MHEG datatype: Boolean-Macro
+//=====
+struct BooleanMacro {
+    MacroDefId
+        macro_def_id;
+    sequence<GenericBoolean,1>
+        generic_boolean;
+};
+
+// Corresponding MHEG datatype: Numeric-Macro
+//=====
+struct NumericMacro {
+    MacroDefId
+        macro_def_id;
+    sequence<GenericNumeric,1>
+        generic_numeric;
+};
+
+// Corresponding MHEG datatype: String-Macro
+//=====
+struct StringMacro {
+    MacroDefId
+        macro_def_id;
+    sequence<GenericString,1>
+        generic_string;
+};
+
+// Corresponding MHEG datatype: Boolean-Parameter
+//=====
+enum BooleanParameterTag { GENERIC_BOOLEAN_TAG, BOOLEAN_MACRO_TAG };
+union BooleanParameter
+switch (BooleanParameterTag){
+    case GENERIC_BOOLEAN_TAG:
+        GenericBoolean
+            generic_boolean;
+    case BOOLEAN_MACRO_TAG:
+        BooleanMacro
+            boolean_macro;
+};
+
+// Corresponding MHEG datatype: Numeric-Parameter
+//=====
+enum NumericParameterTag { GENERIC_NUMERIC_TAG, NUMERIC_MACRO_TAG };
+union NumericParameter
+switch (NumericParameterTag){
+    case GENERIC_NUMERIC_TAG:
+        GenericNumeric
+            generic_numeric;
+    case NUMERIC_MACRO_TAG:
+        NumericMacro
+            numeric_macro;
+};
+
+```
+
+```
+
+// Corresponding MHEG datatype: String-Parameter
+//=====
+enum StringParameterTag { GENERIC_STRING_TAG, STRING_MACRO_TAG };
+union StringParameter
+switch (StringParameterTag){
+    case GENERIC_STRING_TAG:
+        GenericString
+            generic_string;
+    case STRING_MACRO_TAG:
+        StringMacro
+            string_macro;
+};
+
+// Corresponding MHEG datatype: Value-Parameter
+//=====
+enum ValueParameterTag { GENERIC_VALUE_TAG, VALUE_MACRO_TAG };
+union ValueParameter
+switch (ValueParameterTag){
+    case GENERIC_VALUE_TAG:
+        GenericValue
+            generic_value;
+    case VALUE_MACRO_TAG:
+        ValueMacro
+            value_macro;
+};
+
+// Corresponding MHEG datatype: Generic-Volume-Range
+//=====
+struct GenericVolumeRange {
+    sequence<long,1>
+        maximum_volume;
+    sequence<long,1>
+        minimum_volume;
+};
+
+// Corresponding MHEG datatype: Original-Size
+//=====
+struct OriginalSize {
+    sequence<long,1>
+        x_length;
+    sequence<long,1>
+        y_length;
+    sequence<long,1>
+        z_length;
+};
+
+// Corresponding MHEG datatype: Original-Perception
+//=====
+struct OriginalPerception {
+    sequence<long,1>
+        initial_GTR;
+    sequence<long,1>
+        original_duration;
+    sequence<OriginalSize,1>
+        original_size;
+    sequence<GenericVolumeRange,1>
+        audible_volume_range;
+    sequence<long,1>
+        original_volume;
+};
+
+// Corresponding MHEG datatype: Content-Encoding-Identification
+//=====
+enum ContentEncodingIdentificationTag { MHEG_CONTENT_CATALOGUE_TAG,
+PROPRIETARY_CONTENT_CATALOGUE_TAG };
+union ContentEncodingIdentification
+switch (ContentEncodingIdentificationTag){
+    case MHEG_CONTENT_CATALOGUE_TAG:
+        long
+            mheg_content_catalogue;
+    case PROPRIETARY_CONTENT_CATALOGUE_TAG:
+        long
+            proprietary_content_catalogue;
+};
+
+```
+
+```
+
+// Corresponding MHEG datatype: Content-Hook
+//=====
+struct ContentHook {
+    ContentEncodingIdentification
+        content_encoding_identification;
+    string
+        content_encoding_description;
+};
+
+// Corresponding MHEG datatype: Script-Encoding-Identification
+//=====
+enum ScriptEncodingIdentificationTag { MHEG_SCRIPT_CATALOGUE_TAG,
+PROPRIETARY_SCRIPT_CATALOGUE_TAG };
+union ScriptEncodingIdentification
+switch (ScriptEncodingIdentificationTag){
+    case MHEG_SCRIPT_CATALOGUE_TAG:
+        long
+            mheg_script_catalogue;
+    case PROPRIETARY_SCRIPT_CATALOGUE_TAG:
+        long
+            proprietary_script_catalogue;
+};
+
+// Corresponding MHEG datatype: Script-Hook
+//=====
+struct ScriptHook {
+    ScriptEncodingIdentification
+        script_encoding_identification;
+    string
+        script_encoding_description;
+};
+
+// Corresponding MHEG datatype: Content-Classification
+//=====
+enum ContentClassificationTag { MHEG_CONTENT_CLASSIFICATION_TAG,
+PROPRIETARY_CONTENT_CLASSIFICATION_TAG };
+union ContentClassification
+switch (ContentClassificationTag){
+    case MHEG_CONTENT_CLASSIFICATION_TAG:
+        long
+            mheg_content_classification;
+    case PROPRIETARY_CONTENT_CLASSIFICATION_TAG:
+        long
+            proprietary_content_classification;
+};
+
+// Corresponding MHEG datatype: Script-Classification
+//=====
+enum ScriptClassificationTag { MHEG_SCRIPT_CLASSIFICATION_TAG,
+PROPRIETARY_SCRIPT_CLASSIFICATION_TAG };
+union ScriptClassification
+switch (ScriptClassificationTag){
+    case MHEG_SCRIPT_CLASSIFICATION_TAG:
+        long
+            mheg_script_classification;
+    case PROPRIETARY_SCRIPT_CLASSIFICATION_TAG:
+        long
+            proprietary_script_classification;
+};
+
+// Corresponding MHEG datatype: Evaluated-Value
+//=====
+interface EvaluatedValue {
+enum EvaluatedValueTag { GET_PREPARATION_STATUS_TAG, GET_DATA_TAG,
+GET_RT_AVAILABILITY_STATUS_TAG, GET_GLOBAL_BEHAVIOUR_TAG, GET_RUNNING_STATUS_TAG,
+GET_TERMINATION_STATUS_TAG, GET_RGS_TAG, GET_OPACITY_TAG,
+GET_EFFECTIVE_OPACITY_TAG, GET_PRESENTATION_PRIORITY_TAG, GET_PD_TAG,
+GET_INITIAL_TEMPORAL_POSITION_TAG, GET_TERMINAL_TEMPORAL_POSITION_TAG,
+GET_VD_LENGTH_TAG, GET_CURRENT_TEMPORAL_POSITION_TAG, GET_VD_POSITION_TAG,
+GET_SPEED_RATE_TAG, GET_OGTR_TAG, GET_EFFECTIVE_SPEED_RATE_TAG,
+
+```
+
+```
+
+GET_EFFECTIVE_OGTR_TAG, GET_TIMESTONE_STATUS_TAG, GET_GSR_TAG, GET_PS_TAG,
+GET_RESIZING_STRATEGY_TAG, GET_ASPECT_RATIO_TAG, GET_PSAP_TAG, GET_VSGS_TAG,
+GET_VS_TAG, GET_BOX_TAG, GET_DEFAULT_BACKGROUND_TAG, GET_VSIAP_TAG,
+GET_VSIAP_POSITION_TAG, GET_VSEAP_TAG, GET_VSEAP_POSITION_TAG,
+GET_MOVING_ABILITY_TAG, GET_RESIZING_ABILITY_TAG, GET_SCALING_ABILITY_TAG,
+GET_SCROLLING_ABILITY_TAG, GET_IOV_TAG, GET_CURRENT_OV_TAG,
+GET_AUDIBLE_COMPOSITION_EFFECT_TAG, GET_EFFECTIVE_OV_TAG, GET_PERCEPTIBLE_OV_TAG,
+GET_STREAM_CHOSEN_TAG, GET_SELECTABILITY_TAG, GET_EFFECTIVE_SELECTABILITY_TAG,
+GET_SELECTION_STATUS_TAG, GET_SELECTION_MODE_TAG,
+GET_NUMBER_SELECTED_SOCKETS_TAG,
+GET_SELECTION_PRESENTATION_EFFECT_RESPONSIBILITY_TAG, GET_MODIFIABILITY_TAG,
+GET_EFFECTIVE_MODIFIABILITY_TAG, GET_MODIFICATION_STATUS_TAG,
+GET_MODIFICATION_MODE_TAG, GET_NUMBER_MODIFIED_SOCKETS_TAG,
+GET_MODIFICATION_PRESENTATION_EFFECT_RESPONSIBILITY_TAG,
+GET_CHANNEL_AVAILABILITY_STATUS_TAG, GET_CHANNEL_PERCEPTABILITY_TAG };
+union EvaluatedValue
+switch (EvaluatedValueTag){
+    case GET_PREPARATION_STATUS_TAG:
+        MhTargetParameter
+            get_preparation_status;
+    case GET_DATA_TAG:
+        GetData
+            get_data;
+    case GET_RT_AVAILABILITY_STATUS_TAG:
+        RtTargetParameter
+            get_rt_availability_status;
+    case GET_GLOBAL_BEHAVIOUR_TAG:
+        RtTargetParameter
+            get_global_behaviour;
+    case GET_RUNNING_STATUS_TAG:
+        RtTargetParameter
+            get_running_status;
+    case GET_TERMINATION_STATUS_TAG:
+        RtTargetParameter
+            get_termination_status;
+    case GET_RGS_TAG:
+        RtSocketTargetParameter
+            get_RGS;
+    case GET_OPACITY_TAG:
+        RtSocketTargetParameter
+            get_opacity;
+    case GET_EFFECTIVE_OPACITY_TAG:
+        RtSocketTargetParameter
+            get_effective_opacity;
+    case GET_PRESENTATION_PRIORITY_TAG:
+        RtSocketTargetParameter
+            get_presentation_priority;
+    case GET_PD_TAG:
+        GetPD
+            get_PD;
+    case GET_INITIAL_TEMPORAL_POSITION_TAG:
+        RtSocketTargetParameter
+            get_initial_temporal_position;
+    case GET_TERMINAL_TEMPORAL_POSITION_TAG:
+        RtSocketTargetParameter
+            get_terminal_temporal_position;
+    case GET_VD_LENGTH_TAG:
+        GetVDLength
+            get_VD_length;
+    case GET_CURRENT_TEMPORAL_POSITION_TAG:
+        RtSocketTargetParameter
+            get_current_temporal_position;
+    case GET_VD_POSITION_TAG:
+        SocketTargetParameter
+            get_VD_position;
+    case GET_SPEED_RATE_TAG:
+        RtSocketTargetParameter
+            get_speed_rate;
+
+```
+
+```
+
+case GET_OGTR_TAG:
+    RtSocketTargetParameter
+        get_OGTR;
+case GET_EFFECTIVE_SPEED_RATE_TAG:
+    RtSocketTargetParameter
+        get_effective_speed_rate;
+case GET_EFFECTIVE_OGTR_TAG:
+    RtSocketTargetParameter
+        get_effective_OGTR;
+case GET_TIMESTONE_STATUS_TAG:
+    RtSocketTargetParameter
+        get_timestone_status;
+case GET_GSR_TAG:
+    RtSocketTargetParameter
+        get_GSR;
+case GET_PS_TAG:
+    PerceptibleSizeParameter
+        get_PS;
+case GET_RESIZING_STRATEGY_TAG:
+    RtSocketTargetParameter
+        get_resizing_strategy;
+case GET_ASPECT_RATIO_TAG:
+    RtSocketTargetParameter
+        get_aspect_ratio;
+case GET_PSAP_TAG:
+    APPParameter
+        get_PSAP;
+case GET_VSGS_TAG:
+    RtSocketTargetParameter
+        get_VSGS;
+case GET_VS_TAG:
+    RtSocketTargetParameter
+        get_VS;
+case GET_BOX_TAG:
+    RtSocketTargetParameter
+        get_box;
+case GET_DEFAULT_BACKGROUND_TAG:
+    RtSocketTargetParameter
+        get_default_background;
+case GET_VSIAP_TAG:
+    APPParameter
+        get_VSIAP;
+case GET_VSIAP_POSITION_TAG:
+    RtSocketTargetParameter
+        get_VSIAP_position;
+case GET_VSEAP_TAG:
+    APPParameter
+        get_VSEAP;
+case GET_VSEAP_POSITION_TAG:
+    VSEAPPositionParameter
+        get_VSEAP_position;
+case GET_MOVING_ABILITY_TAG:
+    RtSocketTargetParameter
+        get_moving_ability;
+case GET_RESIZING_ABILITY_TAG:
+    RtSocketTargetParameter
+        get_resizing_ability;
+case GET_SCALING_ABILITY_TAG:
+    RtSocketTargetParameter
+        get_scaling_ability;
+case GET_SCROLLING_ABILITY_TAG:
+    RtSocketTargetParameter
+        get_scrolling_ability;
+case GET_IOV_TAG:
+    RtSocketTargetParameter
+        get_IOV;
+case GET_CURRENT_OV_TAG:
+    RtSocketTargetParameter
+        get_current_OV;
+
+```
+
+```
+
+case GET_AUDIBLE_COMPOSITION_EFFECT_TAG:
+    RtSocketTargetParameter
+        get_audible_composition_effect;
+case GET_EFFECTIVE_OV_TAG:
+    RtSocketTargetParameter
+        get_effective_OV;
+case GET_PERCEPTIBLE_OV_TAG:
+    RtSocketTargetParameter
+        get_perceptible_OV;
+case GET_STREAM_CHOSEN_TAG:
+    RtSocketTargetParameter
+        get_stream_chosen;
+case GET_SELECTABILITY_TAG:
+    RtSocketTargetParameter
+        get_selectability;
+case GET_EFFECTIVE_SELECTABILITY_TAG:
+    RtSocketTargetParameter
+        get_effective_selectability;
+case GET_SELECTION_STATUS_TAG:
+    RtSocketTargetParameter
+        get_selection_status;
+case GET_SELECTION_MODE_TAG:
+    RtSocketTargetParameter
+        get_selection_mode;
+case GET_NUMBER_SELECTED_SOCKETS_TAG:
+    RtSocketTargetParameter
+        get_number_selected_sockets;
+case GET_SELECTION_PRESENTATION_EFFECT_RESPONSIBILITY_TAG:
+    RtSocketTargetParameter
+        get_selection_presentation_effect_responsibility;
+case GET_MODIFIABILITY_TAG:
+    RtSocketTargetParameter
+        get_modifiability;
+case GET_EFFECTIVE_MODIFIABILITY_TAG:
+    RtSocketTargetParameter
+        get_effective_modifiability;
+case GET_MODIFICATION_STATUS_TAG:
+    RtSocketTargetParameter
+        get_modification_status;
+case GET_MODIFICATION_MODE_TAG:
+    RtSocketTargetParameter
+        get_modification_mode;
+case GET_NUMBER_MODIFIED_SOCKETS_TAG:
+    RtSocketTargetParameter
+        get_number_modified_sockets;
+case GET_MODIFICATION_PRESENTATION_EFFECT_RESPONSIBILITY_TAG:
+    RtSocketTargetParameter
+        get_modification_presentation_effect_responsibility;
+case GET_CHANNEL_AVAILABILITY_STATUS_TAG:
+    ChannelTargetParameter
+        get_channel_availability_status;
+case GET_CHANNEL_PERCEPTABILITY_TAG:
+    ChannelTargetParameter
+        get_channel_perceptability;
+};
+attribute EvaluatedValue evaluated_value;
+};
+
+// Corresponding MHEG datatype: Delay-Targets
+//=====
+enum DelayTargetsTag { PERCEPTIBLE_TARGETS_TAG, NULL_CHANNEL_TAG };
+union DelayTargets
+switch (DelayTargetsTag){
+    case PERCEPTIBLE_TARGETS_TAG:
+        sequence<RtObjectSocketReference>
+            perceptible_targets;
+};
+
+```
+
+```
+
+// Corresponding MHEG datatype: Delay-Targets-Macro
+//=====
+struct DelayTargetsMacro {
+    MacroDefId
+        macro_def_id;
+    sequence<DelayTargets,1>
+        delay_targets;
+};
+
+// Corresponding MHEG datatype: Delay-Targets-Parameter
+//=====
+enum DelayTargetsParameterTag { DELAY_TARGETS_TAG, DELAY_TARGETS_MACRO_TAG };
+union DelayTargetsParameter
+switch (DelayTargetsParameterTag) {
+    case DELAY_TARGETS_TAG:
+        DelayTargets
+            delay_targets;
+    case DELAY_TARGETS_MACRO_TAG:
+        DelayTargetsMacro
+            delay_targets_macro;
+};
+
+// Corresponding MHEG datatype: Delay
+//=====
+struct Delay {
+    sequence<DelayTargetsParameter,1>
+        targets_parameter;
+    NumericParameter
+        duration;
+};
+
+// Corresponding MHEG datatype: Values
+//=====
+typedef sequence<GenericValue> Values;
+
+// Corresponding MHEG datatype: Values-Macro
+//=====
+struct ValuesMacro {
+    MacroDefId
+        macro_def_if;
+    sequence<Values,1>
+        values;
+};
+
+// Corresponding MHEG datatype: Returned-Values-Parameter
+//=====
+enum ReturnedValuesParameterTag { VALUES_TAG, VALUES_MACRO_TAG };
+union ReturnedValuesParameter
+switch (ReturnedValuesParameterTag) {
+    case VALUES_TAG:
+        Values
+            values;
+    case VALUES_MACRO_TAG:
+        ValuesMacro
+            values_macro;
+};
+
+// Corresponding MHEG datatype: Return
+//=====
+struct Return {
+    NumericParameter
+        return_indicator_param;
+    sequence<ReturnedValuesParameter,1>
+        returned_values_param;
+    sequence<MhTargetsParameter,1>
+        returned_objects_param;
+};
+
+// Corresponding MHEG datatype: Set-Alias
+//=====
+struct SetAlias {
+    sequence<TargetsParameter,1>
+        targets_parameter;
+};
+
+```
+
+```
+
+        StringParameter
+            given_alias;
+};
+
+// Corresponding MHEG datatype: Data-Element
+//=====
+struct DataElement {
+    sequence<ElementListIndexParameter,1>
+        element_list_index_param;
+    sequence<BooleanParameter,1>
+        process_indicator_param;
+    sequence<ValueParameter,1>
+        value_parameter;
+};
+
+// Corresponding MHEG datatype: Set-Data
+//=====
+struct SetData {
+    sequence<MhTargetsParameter,1>
+        content_targets_param;
+    sequence<BooleanParameter,1>
+        substitution_indicator_param;
+    sequence<sequence<DataElement>,1>
+        data_elements;
+};
+
+// Corresponding MHEG datatype: Copy
+//=====
+struct Copy {
+    sequence<MhTargetParameter,1>
+        source;
+    MhTargetsParameter
+        copies;
+};
+
+// Corresponding MHEG datatype: Stream
+//=====
+struct Stream {
+    sequence<long>
+        stream_id;
+    MhTargetParameter
+        content_target;
+};
+
+// Corresponding MHEG datatype: Set-Multiplex
+//=====
+struct SetMultiplex {
+    sequence<MhTargetsParameter,1>
+        multiplex_targets;
+    sequence<Stream>
+        streams;
+};
+
+// Corresponding MHEG datatype: Set-Demultiplex
+//=====
+struct SetDemultiplex {
+    sequence<MhTargetParameter,1>
+        multiplex_targets;
+    sequence<Stream>
+        multiplex;
+};
+
+// Corresponding MHEG datatype: Global-Behaviour
+//=====
+enum GlobalBehaviourTag { GLOBAL_BEHAVIOUR_GET_GLOBAL_BEHAVIOUR_TAG,
+GLOBAL_BEHAVIOUR_GET_DATA_TAG, GLOBAL_BEHAVIOUR_UNSPECIFIED_TAG };
+union GlobalBehaviour
+switch (GlobalBehaviourTag){
+    case GLOBAL_BEHAVIOUR_GET_GLOBAL_BEHAVIOUR_TAG:
+        RtTargetParameter
+            get_global_behaviour;
+
+```
+
+```
+
+        case GLOBAL_BEHAVIOUR_GET_DATA_TAG:
+            GetData
+                get_data;
+};
+
+// Corresponding MHEG datatype: Global-Behaviour-Macro
+//=====
+struct GlobalBehaviourMacro {
+    MacroDefId
+        macro_def_id;
+    sequence<GlobalBehaviour,1>
+        global_behaviour;
+};
+
+// Corresponding MHEG datatype: Global-Behaviour-Parameter
+//=====
+enum GlobalBehaviourParameterTag { GLOBAL_BEHAVIOUR_TAG,
+GLOBAL_BEHAVIOUR_MACRO_TAG };
+union GlobalBehaviourParameter
+switch (GlobalBehaviourParameterTag){
+    case GLOBAL_BEHAVIOUR_TAG:
+        GlobalBehaviour
+            global_behaviour;
+    case GLOBAL_BEHAVIOUR_MACRO_TAG:
+        GlobalBehaviourMacro
+            global_behaviour_macro;
+};
+
+// Corresponding MHEG datatype: Set-Global-Behaviour
+//=====
+struct SetGlobalBehaviour {
+    sequence<RtSocketTargetsParameter,1>
+        rt_sockets_targets_param;
+    sequence<GlobalBehaviourParameter,1>
+        global_behaviour_param;
+};
+
+// Corresponding MHEG datatype: Parameter
+//=====
+enum ParameterTag { PARAMETER_GENERIC_VALUE_TAG, PARAMETER_CONTENT_TARGET_TAG };
+union Parameter
+switch (ParameterTag){
+    case PARAMETER_GENERIC_VALUE_TAG:
+        ValueParameter
+            generic_value;
+    case PARAMETER_CONTENT_TARGET_TAG:
+        MhTargetParameter
+            content_target;
+};
+
+// Corresponding MHEG datatype: Parameters-Macro
+//=====
+struct ParametersMacro {
+    MacroDefId
+        macro_def_id;
+    sequence<sequence<Parameter>,1>
+        parameters;
+};
+
+// Corresponding MHEG datatype: Parameters-Parameter
+//=====
+enum ParametersParameterTag { PARAMETERS_TAG, PARAMETERS_MACRO_TAG };
+union ParametersParameter
+switch (ParametersParameterTag){
+    case PARAMETERS_TAG:
+        sequence<Parameter>
+            parameters;
+    case PARAMETERS_MACRO_TAG:
+        ParametersMacro
+            parameters_macro;
+};
+
+```
+
+```
+
+// Corresponding MHEG datatype: Set-Parameters
+//=====
+struct SetParameters {
+    sequence<RtTargetsParameter,1>
+        rt_script_targets_parameter;
+    ParametersParameter
+        parameters;
+};
+
+// Corresponding MHEG datatype: Plug-In
+//=====
+enum PlugInTag { RT_COMPONENT_REFERENCE_TAG, COMPONENT_REFERENCE_TAG, LABEL_TAG
+};
+union PlugIn
+switch (PlugInTag){
+    case RT_COMPONENT_REFERENCE_TAG:
+        RtObjectReference
+            rt_component_reference;
+    case COMPONENT_REFERENCE_TAG:
+        MhObjectReference
+            component_reference;
+    case LABEL_TAG:
+        GenericString
+            label;
+};
+
+// Corresponding MHEG datatype: Plug-In-Macro
+//=====
+struct PlugInMacro {
+    MacroDefId
+        macro_def_id;
+    sequence<PlugIn,1>
+        plug_in;
+};
+
+// Corresponding MHEG datatype: Plug-In-Parameter
+//=====
+enum PlugInParameterTag { PLUG_IN_TAG, PLUG_IN_MACRO_TAG };
+union PlugInParameter
+switch (PlugInParameterTag){
+    case PLUG_IN_TAG:
+        PlugIn
+            plug_in;
+    case PLUG_IN_MACRO_TAG:
+        PlugInMacro
+            plug_in_macro;
+};
+
+// Corresponding MHEG datatype: Plug
+//=====
+struct Plug {
+    sequence<SocketTargetsParameter,1>
+        socket_targets_parameter;
+    PlugInParameter
+        plug_in_parameter;
+};
+
+// Corresponding MHEG datatype: Set-RGS
+//=====
+struct SetRGS {
+    sequence<RtSocketTargetsParameter,1>
+        perceptible_targets_param;
+    sequence<ChannelTargetParameter,1>
+        rgs_parameter;
+};
+
+// Corresponding MHEG datatype: Set-Opacity
+
+```
+
+```
+
+//=====
+struct SetOpacity {
+    sequence<RtSocketTargetsParameter,1>
+        perceptible_targets_param;
+    sequence<NumericParameter,1>
+        opacity_rate;
+    sequence<NumericParameter,1>
+        transition_duration_param;
+};
+
+// Corresponding MHEG datatype: Presentation-Priority
+//=====
+enum PresentationPriorityTag { PRESENTATION_PRIORITY_GENERIC_NUMERIC_TAG,
+PRESENTATION_PRIORITY_PRIORITY_LEVEL_TAG };
+union PresentationPriority
+switch (PresentationPriorityTag){
+    case PRESENTATION_PRIORITY_GENERIC_NUMERIC_TAG:
+        GenericNumeric
+            generic_numeric;
+    case PRESENTATION_PRIORITY_PRIORITY_LEVEL_TAG:
+        PriorityLevel
+            priority_level;
+};
+
+// Corresponding MHEG datatype: Presentation-Priority-Macro
+//=====
+struct PresentationPriorityMacro {
+    MacroDefId
+        macro_def_id;
+    sequence<PresentationPriority,1>
+        presentation_priority;
+};
+
+// Corresponding MHEG datatype: Presentation-Priority-Parameter
+//=====
+enum PresentationPriorityParameterTag { PRESENTATION_PRIORITY_TAG,
+PRESENTATION_PRIORITY_MACRO_TAG };
+union PresentationPriorityParameter
+switch (PresentationPriorityParameterTag){
+    case PRESENTATION_PRIORITY_TAG:
+        PresentationPriority
+            presentation_priority;
+    case PRESENTATION_PRIORITY_MACRO_TAG:
+        PresentationPriorityMacro
+            presentation_priority_macro;
+};
+
+// Corresponding MHEG datatype: Set-Presentation-Priority
+//=====
+struct SetPresentationPriority {
+    sequence<RtSocketTargetsParameter,1>
+        perceptible_targets_param;
+    sequence<PresentationPriorityParameter,1>
+        presentation_priority_param;
+    sequence<NumericParameter,1>
+        transition_duration_param;
+};
+
+// Corresponding MHEG datatype: Temporal-Position-Macro
+//=====
+struct TemporalPositionMacro {
+    MacroDefId
+        macro_def_id;
+    sequence<TemporalPosition,1>
+        temporal_position;
+};
+
+// Corresponding MHEG datatype: Temporal-Position-Parameter
+//=====
+enum TemporalPositionParameterTag { TEMPORAL_POSITION_TAG,
+TEMPORAL_POSITION_MACRO_TAG };
+union TemporalPositionParameter
+
+```
+
+```
+
+switch (TemporalPositionParameterTag) {
+    case TEMPORAL_POSITION_TAG:
+        TemporalPosition
+            temporal_position;
+    case TEMPORAL_POSITION_MACRO_TAG:
+        TemporalPositionMacro
+            temporal_position_macro;
+};
+
+// Corresponding MHEG datatype: Set-Visible-Duration
+//=====
+struct SetVisibleDuration {
+    sequence<RtSocketTargetsParameter,1>
+        perceptible_targets_parameter;
+    sequence<TemporalPositionParameter,1>
+        initial_temporal_position_parameter;
+    sequence<TemporalPositionParameter,1>
+        terminal_temporal_position_parameter;
+};
+
+// Corresponding MHEG datatype: Temporal-Termination-Macro
+//=====
+struct TemporalTerminationMacro {
+    MacroDefId
+        macro_def_id;
+    sequence<TemporalTermination,1>
+        temporal_termination;
+};
+
+// Corresponding MHEG datatype: Temporal-Termination-Parameter
+//=====
+enum TemporalTerminationParameterTag {
+    TEMPORAL_TERMINATION_PARAMETER_TEMPORAL_TERMINATION_TAG,
+    TEMPORAL_TERMINATION_PARAMETER_TEMPORAL_TERMINATION_MACRO_TAG };
+union TemporalTerminationParameter
+switch (TemporalTerminationParameterTag) {
+    case TEMPORAL_TERMINATION_PARAMETER_TEMPORAL_TERMINATION_TAG:
+        TemporalTermination
+            temporal_termination;
+    case TEMPORAL_TERMINATION_PARAMETER_TEMPORAL_TERMINATION_MACRO_TAG:
+        TemporalTerminationMacro
+            temporal_termination_macro;
+};
+
+// Corresponding MHEG datatype: Set-Temporal-Termination
+//=====
+struct SetTemporalTermination {
+    sequence<RtSocketTargetsParameter,1>
+        perceptible_targets_parameter;
+    TemporalTerminationParameter
+        temporal_termination_parameter;
+};
+
+// Corresponding MHEG datatype: Current-Temporal-Position-Macro
+//=====
+struct CurrentTemporalPositionMacro {
+    MacroDefId
+        macro_def_id;
+    sequence<CurrentTemporalPosition,1>
+        current_temporal_termination;
+};
+
+// Corresponding MHEG datatype: Current-Temporal-Position-Parameter
+//=====
+enum CurrentTemporalPositionParameterTag { CURRENT_TEMPORAL_POSITION_TAG,
+    CURRENT_TEMPORAL_POSITION_MACRO_TAG };
+union CurrentTemporalPositionParameter
+switch (CurrentTemporalPositionParameterTag) {
+    case CURRENT_TEMPORAL_POSITION_TAG:
+        CurrentTemporalPosition
+            current_temporal_position;
+    case CURRENT_TEMPORAL_POSITION_MACRO_TAG:
+        CurrentTemporalPositionMacro
+            current_temporal_position_macro;
+};
+
+```
+
+```
+
+// Corresponding MHEG datatype: Set-Current-Temporal-Position
+//=====
+struct SetCurrentTemporalPosition {
+    sequence<RtSocketTargetsParameter,1>
+        perceptible_targets_parameter;
+    sequence<CurrentTemporalPositionParameter,1>
+        temporal_position_parameter;
+};
+
+// Corresponding MHEG datatype: Visible-Duration-Macro
+//=====
+struct VisibleDurationPositionMacro {
+    MacroDefId
+        macro_def_id;
+    sequence<VisibleDurationPosition,1>
+        visible_duration_position;
+};
+
+// Corresponding MHEG datatype: Visible-Duration-Parameter
+//=====
+enum VisibleDurationPositionParameterTag { VISIBLE_DURATION_POSITION_TAG,
+VISIBLE_DURATION_POSITION_MACRO_TAG };
+union VisibleDurationPositionParameter
+switch (VisibleDurationPositionParameterTag){
+    case VISIBLE_DURATION_POSITION_TAG:
+        VisibleDurationPosition
+            visible_duration_position;
+    case VISIBLE_DURATION_POSITION_MACRO_TAG:
+        VisibleDurationPositionMacro
+            visible_duration_position_macro;
+};
+
+// Corresponding MHEG datatype: Set-Visible-Duration-Position
+//=====
+struct SetVisibleDurationPosition {
+    sequence<SocketTargetsParameter,1>
+        socket_targets;
+    sequence<VisibleDurationPositionParameter,1>
+        visible_duration_position_param;
+};
+
+// Corresponding MHEG datatype: Speed-Macro
+//=====
+struct SpeedMacro {
+    MacroDefId
+        macro_def_id;
+    sequence<Speed,1>
+        speed;
+};
+
+// Corresponding MHEG datatype: Speed-Parameter
+//=====
+enum SpeedParameterTag { SPEED_TAG, SPEED_MACRO_TAG };
+union SpeedParameter
+switch (SpeedParameterTag){
+    case SPEED_TAG:
+        Speed
+            speed;
+    case SPEED_MACRO_TAG:
+        SpeedMacro
+            speed_macro;
+};
+
+// Corresponding MHEG datatype: Set-Speed
+//=====
+struct SetSpeed {
+    RtSocketTargetsParameter
+        perceptible_targets_parameter;
+    sequence<SpeedParameter,1>
+        speed_parameter;
+    sequence<NumericParameter,1>
+        transition_duration_parameter;
+};
+
+```
+
+```
+
+// Corresponding MHEG datatype: Timestone-Macro
+//=====
+struct TimestoneMacro {
+    MacroDefId
+        macro_def_id;
+    sequence<Timestone,1>
+        timestone;
+};
+
+// Corresponding MHEG datatype: Timestone-Parameter
+//=====
+enum TimestoneParameterTag { Timestone_TAG, Timestone_MACRO_TAG };
+union TimestoneParameter
+switch (TimestoneParameterTag){
+    case Timestone_TAG:
+        Timestone
+            timestone;
+    case Timestone_MACRO_TAG:
+        TimestoneMacro
+            timestone_macro;
+};
+
+// Corresponding MHEG datatype: Set-Timestones
+//=====
+struct SetTimestones {
+    sequence<RtSocketTargetsParameter,1>
+        perceptible_targets_parameter;
+    sequence<sequence<TimestoneParameter>,1>
+        timestones_parameter;
+};
+
+// Corresponding MHEG datatype: Perceptible-Size-Projection-Macro
+//=====
+struct PerceptibleSizeProjectionMacro {
+    MacroDefId
+        macro_def_id;
+    sequence<PerceptibleSizeProjection,1>
+        perceptible_size_projection;
+};
+
+// Corresponding MHEG datatype: Perceptible-Size-Projection-Parameter
+//=====
+enum PerceptibleSizeProjectionParameterTag { PERCEPTIBLE_SIZE_PROJECTION_TAG,
+PERCEPTIBLE_SIZE_PROJECTION_MACRO_TAG };
+union PerceptibleSizeProjectionParameter
+switch (PerceptibleSizeProjectionParameterTag){
+    case PERCEPTIBLE_SIZE_PROJECTION_TAG:
+        PerceptibleSizeProjection
+            perceptible_size_projection;
+    case PERCEPTIBLE_SIZE_PROJECTION_MACRO_TAG:
+        PerceptibleSizeProjectionMacro
+            perceptible_size_projection_macro;
+};
+
+// Corresponding MHEG datatype: Set-Perceptible-Size-Projection
+//=====
+struct SetPerceptibleSizeProjection {
+    sequence<RtSocketTargetsParameter,1>
+        perceptible_targets_parameter;
+    PerceptibleSizeProjectionParameter
+        perceptible_size_projection;
+    sequence<NumericParameter,1>
+        transition_duration_parameter;
+};
+
+// Corresponding MHEG datatype: Resizing-Strategy-Macro
+//=====
+struct ResizingStrategyMacro {
+    MacroDefId
+        macro_def_id;
+    sequence<ResizingStrategy,1>
+        resizing_strategy;
+};
+
+```
+
+```
+
+// Corresponding MHEG datatype: Resizing-Strategy-Parameter
+//=====
+enum ResizingStrategyParameterTag {
+RESIZING_STRATEGY_PARAMETER_RESIZING_STRATEGY_TAG,
+RESIZING_STRATEGY_PARAMETER_RESIZING_STRATEGY_MACRO_TAG };
+union ResizingStrategyParameter
+switch (ResizingStrategyParameterTag){
+    case RESIZING_STRATEGY_PARAMETER_RESIZING_STRATEGY_TAG:
+        ResizingStrategy
+            resizing_strategy;
+    case RESIZING_STRATEGY_PARAMETER_RESIZING_STRATEGY_MACRO_TAG:
+        ResizingStrategyMacro
+            resizing_strategy_macro;
+};
+
+// Corresponding MHEG datatype: Set-Resizing-Strategy
+//=====
+struct SetResizingStrategy {
+    sequence<RtSocketTargetsParameter,1>
+        perceptible_targets_parameter;
+    sequence<ResizingStrategyParameter,1>
+        resizing_strategy_parameter;
+};
+
+// Corresponding MHEG datatype: Set-Aspect-Ratio-Preserved
+//=====
+struct SetAspectRatioPreserved {
+    sequence<RtSocketTargetsParameter,1>
+        perceptible_targets_parameter;
+    BooleanParameter
+        preserved;
+};
+
+// Corresponding MHEG datatype: VSGS-Macro
+//=====
+struct VSGSMacro {
+    MacroDefId
+        macro_def_id;
+    sequence<VSGS,1>
+        vsgs;
+};
+
+// Corresponding MHEG datatype: VSGS-Parameter
+//=====
+enum VSGSParameterTag { VSGS_PARAMETER_VSGS_TAG, VSGS_PARAMETER_VSGS_MACRO_TAG };
+union VSGSParameter
+switch (VSGSParameterTag){
+    case VSGS_PARAMETER_VSGS_TAG:
+        VSGS
+            vsgs;
+    case VSGS_PARAMETER_VSGS_MACRO_TAG:
+        VSGSMacro
+            vsgs_macro;
+};
+
+// Corresponding MHEG datatype: Size-Attribute-Macro
+//=====
+struct SizeAttributeMacro {
+    MacroDefId
+        macro_def_id;
+    sequence<SizeAttribute,1>
+        size_attribute;
+};
+
+// Corresponding MHEG datatype: Size-Attribute-Parameter
+//=====
+enum SizeAttributeParameterTag { SIZE_ATTRIBUTE_TAG, SIZE_ATTRIBUTE_MACRO_TAG };
+union SizeAttributeParameter
+switch (SizeAttributeParameterTag){
+    case SIZE_ATTRIBUTE_TAG:
+        SizeAttribute
+            size_attribute;
+
+```
+
+```
+
+        case SIZE_ATTRIBUTE_MACRO_TAG:
+            SizeAttributeMacro
+                size_attribute_macro;
+};
+
+// Corresponding MHEG datatype: VS-Parameter
+//=====
+enum VSParameterTag { X_SIZE_ATTRIBUTE_PARAMETER_TAG,
+Y_SIZE_ATTRIBUTE_PARAMETER_TAG, Z_SIZE_ATTRIBUTE_PARAMETER_TAG };
+union VSParameter
+switch (VSParameterTag){
+    case X_SIZE_ATTRIBUTE_PARAMETER_TAG:
+        SizeAttributeParameter
+            x_size_attribute_parameter;
+    case Y_SIZE_ATTRIBUTE_PARAMETER_TAG:
+        SizeAttributeParameter
+            y_size_attribute_parameter;
+    case Z_SIZE_ATTRIBUTE_PARAMETER_TAG:
+        SizeAttributeParameter
+            z_size_attribute_parameter;
+};
+
+// Corresponding MHEG datatype: Set-Visible-Size
+//=====
+struct SetVisibleSize {
+    sequence<RtSocketTargetsParameter,1>
+        perceptible_targets_parameter;
+    VSGSPParameter
+        vsgs_parameter;
+    VSParameter
+        vs_parameter;
+    sequence<NumericParameter,1>
+        transition_duration_parameter;
+};
+
+// Corresponding MHEG datatype: Adjustment-Axis-Macro
+//=====
+struct AdjustmentAxisMacro {
+    MacroDefId
+        macro_def_id;
+    sequence<AdjustmentAxis,1>
+        adjustment_axis;
+};
+
+// Corresponding MHEG datatype: Adjustment-Axis-Parameter
+//=====
+enum AdjustmentAxisParameterTag { ADJUSTMENT_AXIS_TAG, ADJUSTMENT_AXIS_MACRO_TAG
+};
+union AdjustmentAxisParameter
+switch (AdjustmentAxisParameterTag){
+    case ADJUSTMENT_AXIS_TAG:
+        AdjustmentAxis
+            adjustment_axis;
+    case ADJUSTMENT_AXIS_MACRO_TAG:
+        AdjustmentAxisMacro
+            adjustment_axis_macro;
+};
+
+// Corresponding MHEG datatype: Adjustment-Policy-Macro
+//=====
+struct AdjustmentPolicyMacro {
+    MacroDefId
+        macro_def_id;
+    sequence<AdjustmentPolicy,1>
+        adjustment_policy;
+};
+
+// Corresponding MHEG datatype: Adjustment-Policy-Parameter
+//=====
+enum AdjustmentPolicyParameterTag { ADJUSTMENT_POLICY_TAG,
+ADJUSTMENT_POLICY_MACRO_TAG };
+union AdjustmentPolicyParameter
+switch (AdjustmentPolicyParameterTag){
+
+```
+
+```
+
+    case ADJUSTMENT_POLICY_TAG:
+        AdjustmentPolicy
+            adjustment_policy;
+    case ADJUSTMENT_POLICY_MACRO_TAG:
+        AdjustmentPolicyMacro
+            adjustment_policy_macro;
+};
+
+// Corresponding MHEG datatype: Set-Visible-Sizes-Adjustment
+//=====
+struct SetVisibleSizesAdjustment {
+    sequence<AdjustmentAxisParameter>
+        adjustment_axis_set;
+    AdjustmentPolicyParameter
+        adjustment_policy;
+    sequence<NumericParameter,1>
+        transition_duration_parameter;
+};
+
+// Corresponding MHEG datatype: Set-Box
+//=====
+struct SetBox {
+    sequence<RtSocketTargetsParameter,1>
+        perceptible_targets_parameter;
+    sequence<BooleanParameter,1>
+        box_parameter;
+};
+
+// Corresponding MHEG datatype: Set-Default-Background
+//=====
+struct SetDefaultBackground {
+    sequence<RtSocketTargetsParameter,1>
+        perceptible_targets_parameter;
+    sequence<NumericParameter,1>
+        background_parameter;
+    sequence<NumericParameter,1>
+        transition_duration;
+};
+
+// Corresponding MHEG datatype: Attachment-Point-Type-Macro
+//=====
+struct AttachmentPointTypeMacro {
+    MacroDefId
+        macro_def_id;
+    sequence<AttachmentPointType,1>
+        attachment_point_type;
+};
+
+// Corresponding MHEG datatype: Attachment-Point-Type-Parameter
+//=====
+enum AttachmentPointTypeParameterTag { ATTACHMENT_POINT_TYPE_TAG,
+ATTACHMENT_POINT_TYPE_MACRO_TAG };
+union AttachmentPointTypeParameter
+switch (AttachmentPointTypeParameterTag) {
+    case ATTACHMENT_POINT_TYPE_TAG:
+        AttachmentPointType
+            attachment_point_type;
+    case ATTACHMENT_POINT_TYPE_MACRO_TAG:
+        AttachmentPointTypeMacro
+            attachment_point_type_macro;
+};
+
+// Corresponding MHEG datatype: Attachment-Attribute-Macro
+//=====
+struct AttachmentAttributeMacro {
+    MacroDefId
+        macro_def_id;
+    sequence<AttachmentAttribute,1>
+        attachment_attribute;
+};
+
+```
+
+```
+
+// Corresponding MHEG datatype: Attachment-Attribute-Parameter
+//=====
+enum AttachmentAttributeParameterTag { ATTACHMENT_ATTRIBUTE_TAG,
+ATTACHMENT_ATTRIBUTE_MACRO_TAG };
+union AttachmentAttributeParameter
+switch (AttachmentAttributeParameterTag){
+    case ATTACHMENT_ATTRIBUTE_TAG:
+        AttachmentAttribute
+            attachment_attribute;
+    case ATTACHMENT_ATTRIBUTE_MACRO_TAG:
+        AttachmentAttributeMacro
+            attachment_attribute_macro;
+};
+
+// Corresponding MHEG datatype: Attachment-Point-Parameter
+//=====
+struct AttachmentPointParameter {
+    sequence<AttachmentAttributeParameter,1>
+        x_attachment_parameter;
+    sequence<AttachmentAttributeParameter,1>
+        y_attachment_parameter;
+    sequence<AttachmentAttributeParameter,1>
+        z_attachment_parameter;
+};
+
+// Corresponding MHEG datatype: Set-Attachment-Point
+//=====
+struct SetAttachmentPoint {
+    sequence<RtSocketTargetsParameter,1>
+        perceptible_targets_parameter;
+    sequence<AttachmentPointTypeParameter,1>
+        attachment_point_type_param;
+    sequence<AttachmentPointParameter,1>
+        attachment_point_param;
+};
+
+// Corresponding MHEG datatype: Reference-Type-Macro
+//=====
+struct ReferenceTypeMacro {
+    MacroDefId
+        macro_def_id;
+    sequence<ReferenceType,1>
+        reference_type;
+};
+
+// Corresponding MHEG datatype: Reference-Type-Parameter
+//=====
+enum ReferenceTypeParameterTag { REFERENCE_TYPE_TAG, REFERENCE_TYPE_MACRO_TAG };
+union ReferenceTypeParameter
+switch (ReferenceTypeParameterTag){
+    case REFERENCE_TYPE_TAG:
+        ReferenceType
+            reference_type;
+    case REFERENCE_TYPE_MACRO_TAG:
+        ReferenceTypeMacro
+            reference_type_macro;
+};
+
+// Corresponding MHEG datatype: VSEAP-Reference-Point
+//=====
+enum VSEAPReferencePointTag { ORIGIN_TAG, COMPONENT_TAG };
+union VSEAPReferencePoint
+switch (VSEAPReferencePointTag){
+    case COMPONENT_TAG:
+        SocketTargetParameter
+            component;
+};
+
+// Corresponding MHEG datatype: VSEAP-Reference-Point-Macro
+//=====
+struct VSEAPReferencePointMacro {
+    MacroDefId
+        macro_def_id;
+
+```
+
+```
+
+sequence<VSEAPReferencePoint,1>
+    vseap_reference;
+};
+
+// Corresponding MHEG datatype: VSEAP-Reference-Parameter
+//=====
+enum VSEAPReferenceParameterTag { VSEAP_REFERENCE_TAG, VSEAP_REFERENCE_MACRO_TAG
+};
+union VSEAPReferenceParameter
+switch (VSEAPReferenceParameterTag){
+    case VSEAP_REFERENCE_TAG:
+        VSEAPReferencePoint
+            vseap_reference;
+    case VSEAP_REFERENCE_MACRO_TAG:
+        VSEAPReferencePointMacro
+            vseap_reference_macro;
+};
+
+// Corresponding MHEG datatype: Length-Attribute-Macro
+//=====
+struct LengthAttributeMacro {
+    MacroDefId
+        macro_def_id;
+    sequence<LengthAttribute,1>
+        length_attribute;
+};
+
+// Corresponding MHEG datatype: Length-Attribute-Parameter
+//=====
+enum LengthAttributeParameterTag { LENGTH_ATTRIBUTE_TAG,
+LENGTH_ATTRIBUTE_MACRO_TAG };
+union LengthAttributeParameter
+switch (LengthAttributeParameterTag){
+    case LENGTH_ATTRIBUTE_TAG:
+        LengthAttribute
+            length_attribute;
+    case LENGTH_ATTRIBUTE_MACRO_TAG:
+        LengthAttributeMacro
+            length_attribute_macro;
+};
+
+// Corresponding MHEG datatype: Lengths-Parameter
+//=====
+struct LengthsParameter {
+    sequence<LengthAttributeParameter,1>
+        x_length_parameter;
+    sequence<LengthAttributeParameter,1>
+        y_position_parameter;
+    sequence<LengthAttributeParameter,1>
+        z_position_parameter;
+};
+
+// Corresponding MHEG datatype: Set-Attachment-Point-Position
+//=====
+struct SetAttachmentPointPosition {
+    sequence<RtSocketTargetsParameter,1>
+        perceptible_targets_parameter;
+    sequence<ReferenceTypeParameter,1>
+        attachment_type_parameter;
+    sequence<VSEAPReferenceParameter,1>
+        vseap_reference_parameter;
+    sequence<LengthsParameter,1>
+        positions_parameter;
+    sequence<NumericParameter,1>
+        transition_duration_parameter;
+};
+
+// Corresponding MHEG datatype: Size-Border-Macro
+//=====
+struct SizeBorderMacro {
+    MacroDefId
+        macro_def_id;
+    sequence<SizeBorder,1>
+        size_border;
+};
+
+```
+
+```
+
+// Corresponding MHEG datatype: Size-Border-Parameter
+//=====
+enum SizeBorderParameterTag { SIZE_BORDER_TAG, SIZE_BORDER_MACRO_TAG };
+union SizeBorderParameter
+switch (SizeBorderParameterTag) {
+    case SIZE_BORDER_TAG:
+        SizeBorder
+            size_border;
+    case SIZE_BORDER_MACRO_TAG:
+        SizeBorderMacro
+            size_border_macro;
+};
+
+// Corresponding MHEG datatype: Set-Visible-Sizes-Alignment
+//=====
+struct SetVisibleSizesAlignment {
+    sequence<RtSocketTargetsParameter,1>
+        perceptible_targets_parameter;
+    sequence<SizeBorderParameter,1>
+        size_border_parameter;
+    sequence<NumericParameter,1>
+        margin_parameter;
+    sequence<NumericParameter,1>
+        transition_duration;
+};
+
+// Corresponding MHEG datatype: User-Controls-Macro
+//=====
+struct UserControlsMacro {
+    MacroDefId
+        macro_def_id;
+    sequence<UserControls,1>
+        user_controls;
+};
+
+// Corresponding MHEG datatype: User-Controls-Parameter
+//=====
+enum UserControlsParameterTag { USER_CONTROLS_PARAMETER_USER_CONTROLS_TAG,
+USER_CONTROLS_PARAMETER_USER_CONTROLS_MACRO_TAG };
+union UserControlsParameter
+switch (UserControlsParameterTag) {
+    case USER_CONTROLS_PARAMETER_USER_CONTROLS_TAG:
+        UserControls
+            user_controls;
+    case USER_CONTROLS_PARAMETER_USER_CONTROLS_MACRO_TAG:
+        UserControlsMacro
+            user_controls_macro;
+};
+
+// Corresponding MHEG datatype: Set-Moving-Ability
+//=====
+struct SetMovingAbility {
+    sequence<RtSocketTargetsParameter,1>
+        perceptible_targets_parameter;
+    sequence<UserControlsParameter,1>
+        allowed;
+};
+
+// Corresponding MHEG datatype: Set-Resizing-Ability
+//=====
+struct SetResizingAbility {
+    sequence<RtSocketTargetsParameter,1>
+        perceptible_targets_parameter;
+    sequence<UserControlsParameter,1>
+        allowed;
+};
+
+// Corresponding MHEG datatype: Set-Scaling-Ability
+//=====
+struct SetScalingAbility {
+    sequence<RtSocketTargetsParameter,1>
+        perceptible_targets_parameter;
+    sequence<UserControlsParameter,1>
+        allowed;
+};
+
+```
+
+```
+
+// Corresponding MHEG datatype: Set-Scrolling-Ability
+//=====
+struct SetScrollingAbility {
+    sequence<RtSocketTargetsParameter,1>
+        perceptible_targets_parameter;
+    sequence<UserControlsParameter,1>
+        allowed;
+};
+
+// Corresponding MHEG datatype: Audible-Volume-Macro
+//=====
+struct AudibleVolumeMacro {
+    MacroDefId
+        macro_def_id;
+    sequence<AudibleVolume,1>
+        audible_volume;
+};
+
+// Corresponding MHEG datatype: Audible-Volume-Parameter
+//=====
+enum AudibleVolumeParameterTag { AUDIBLE_VOLUME_TAG, AUDIBLE_VOLUME_MACRO_TAG };
+union AudibleVolumeParameter
+switch (AudibleVolumeParameterTag){
+    case AUDIBLE_VOLUME_TAG:
+        AudibleVolume
+            audible_volume;
+    case AUDIBLE_VOLUME_MACRO_TAG:
+        AudibleVolumeMacro
+            audible_volume_macro;
+};
+
+// Corresponding MHEG datatype: Set-Audible-Volume
+//=====
+struct SetAudibleVolume {
+    sequence<RtSocketTargetsParameter,1>
+        perceptible_targets_parameter;
+    sequence<AudibleVolumeParameter,1>
+        audible_volume_parameter;
+    sequence<NumericParameter,1>
+        transition_duration_parameter;
+};
+
+// Corresponding MHEG datatype: Set-Audible-Composition-Effect
+//=====
+struct SetAudibleCompositionEffect {
+    sequence<RtSocketTargetsParameter,1>
+        perceptible_targets_parameter;
+    sequence<NumericParameter,1>
+        audible_effect_parameter;
+    sequence<NumericParameter,1>
+        transition_duration_parameter;
+};
+
+// Corresponding MHEG datatype: Stream-Identifier-Macro
+//=====
+struct StreamIdentifierMacro {
+    MacroDefId
+        macro_def_id;
+    sequence<StreamIdentifier,1>
+        stream_identifier;
+};
+
+// Corresponding MHEG datatype: Stream-Identifier-Parameter
+//=====
+enum StreamIdentifierParameterTag { STREAM_IDENTIFIER_TAG,
+STREAM IDENTIFIER MACRO TAG };
+union StreamIdentifierParameter
+switch (StreamIdentifierParameterTag){
+    case STREAM_IDENTIFIER_TAG:
+        StreamIdentifier
+            stream_identifier;
+    case STREAM_IDENTIFIER_MACRO_TAG:
+        StreamIdentifierMacro
+            stream_identifier_macro;
+};
+
+```
+
+```
+
+// Corresponding MHEG datatype: Set-Stream-Choice
+//=====
+struct SetStreamChoice {
+    RtSocketTargetsParameter
+        rt_multiplexed_content_socket_param;
+    sequence<StreamIdentifierParameter,1>
+        stream_identifier_parameter;
+};
+
+// Corresponding MHEG datatype: Set-Selectability
+//=====
+struct SetSelectability {
+    sequence<RtSocketTargetsParameter,1>
+        perceptible_targets_parameter;
+    sequence<NumericParameter,1>
+        min_number_selections;
+    sequence<NumericParameter,1>
+        max_number_selections;
+};
+
+// Corresponding MHEG datatype: Selection-State-Macro
+//=====
+struct SelectionStateMacro {
+    MacroDefId
+        macro_def_id;
+    sequence<SelectionStatusValue,1>
+        modification_state;
+};
+
+// Corresponding MHEG datatype: Selection-State-Parameter
+//=====
+enum SelectionStateParameterTag { SELECTION_STATE_MACRO_TAG, SELECTION_STATE_TAG };
+union SelectionStateParameter
+switch (SelectionStateParameterTag){
+    case SELECTION_STATE_MACRO_TAG:
+        SelectionStateMacro
+            selection_state_macro;
+    case SELECTION_STATE_TAG:
+        SelectionStatusValue
+            selection_state;
+};
+
+// Corresponding MHEG datatype: Set-Selection-Status
+//=====
+struct SetSelectionStatus {
+    sequence<RtSocketTargetsParameter,1>
+        perceptible_targets_parameter;
+    sequence<SelectionStateParameter,1>
+        selection_state_parameter;
+};
+
+// Corresponding MHEG datatype: Responsibility-Macro
+//=====
+struct ResponsibilityMacro {
+    MacroDefId
+        macro_def_id;
+    sequence<Responsibility,1>
+        responsibility;
+};
+
+// Corresponding MHEG datatype: Responsibility-Parameter
+//=====
+enum ResponsibilityParameterTag { RESPONSIBILITY_PARAMETER_RESPONSIBILITY_TAG,
+RESPONSIBILITY_PARAMETER_RESPONSIBILITY_MACRO_TAG };
+union ResponsibilityParameter
+switch (ResponsibilityParameterTag){
+    case RESPONSIBILITY_PARAMETER_RESPONSIBILITY_TAG:
+        Responsibility
+            responsibility;
+    case RESPONSIBILITY_PARAMETER_RESPONSIBILITY_MACRO_TAG:
+        ResponsibilityMacro
+            responsibility_macro;
+};
+
+```
+
+```
+
+// Corresponding MHEG datatype: Set-Selection-Presentation-Effect-Responsibility
+//=====
+struct SetSelectionPresentationEffectResponsibility {
+    sequence<RtSocketTargetsParameter,1>
+        perceptible_targets_parameter;
+    sequence<ResponsibilityParameter,1>
+        selection_responsibility;
+};
+
+// Corresponding MHEG datatype: Set-Modifiability
+//=====
+struct SetModifiability {
+    sequence<RtSocketTargetsParameter,1>
+        perceptible_targets_parameter;
+    sequence<NumericParameter,1>
+        min_number_modifications;
+    sequence<NumericParameter,1>
+        max_number_modifications;
+};
+
+// Corresponding MHEG datatype: Modification-State-Macro
+//=====
+struct ModificationStateMacro {
+    MacroDefId
+        macro_def_id;
+    sequence<ModificationStatusValue,1>
+        modification_state;
+};
+
+// Corresponding MHEG datatype: Modification-State-Parameter
+//=====
+enum ModificationStateParameterTag { MODIFICATION_STATE_MACRO_TAG,
+MODIFICATION_STATE_TAG };
+union ModificationStateParameter
+switch (ModificationStateParameterTag){
+    case MODIFICATION_STATE_MACRO_TAG:
+        ModificationStateMacro
+            modification_state_macro;
+    case MODIFICATION_STATE_TAG:
+        ModificationStatusValue
+            modification_state;
+};
+
+// Corresponding MHEG datatype: Set-Modification-Status
+//=====
+struct SetModificationStatus {
+    sequence<RtSocketTargetsParameter,1>
+        perceptible_targets_parameter;
+    sequence<ModificationStateParameter,1>
+        modification_state_parameter;
+};
+
+// Corresponding MHEG datatype: Set-Modification-Presentation-Effect-
+// Responsibility
+//=====
+struct SetModificationPresentationEffectResponsibility {
+    sequence<RtSocketTargetsParameter,1>
+        perceptible_targets_parameter;
+    sequence<ResponsibilityParameter,1>
+        modification_responsibility;
+};
+
+// Corresponding MHEG datatype: Presentation-State-Macro
+//=====
+struct PresentationStateMacro {
+    MacroDefId
+        macro_def_id;
+    sequence<PresentationState,1>
+        presentation_state;
+};
+
+```
+
+```
+
+// Corresponding MHEG datatype: Presentation-State-Parameter
+//=====
+enum PresentationStateParameterTag { PRESENTATION_STATE_MACRO_TAG,
+PRESENTATION_STATE_TAG };
+union PresentationStateParameter
+switch (PresentationStateParameterTag){
+    case PRESENTATION_STATE_MACRO_TAG:
+        PresentationStateMacro
+            presentation_state_macro;
+    case PRESENTATION_STATE_TAG:
+        PresentationState
+            presentation_state;
+};
+
+// Corresponding MHEG datatype: Alternate-Presentation-State-Macro
+//=====
+struct AlternatePresentationMacro {
+    MacroDefId
+        macro_def_id;
+    sequence<AlternatePresentation,1>
+        alternate_presentation_state;
+};
+
+// Corresponding MHEG datatype: Alternate-Presentation-State-Parameter
+//=====
+enum AlternatePresentationParameterTag { ALTERNATE_PRESENTATION_MACRO_TAG,
+ALTERNATE_PRESENTATION_TAG };
+union AlternatePresentationParameter
+switch (AlternatePresentationParameterTag){
+    case ALTERNATE_PRESENTATION_MACRO_TAG:
+        AlternatePresentationMacro
+            alternate_presentation_macro;
+    case ALTERNATE_PRESENTATION_TAG:
+        AlternatePresentation
+            alternate_presentation;
+};
+
+// Corresponding MHEG datatype: Set-Button-Style
+//=====
+struct SetButtonStyle {
+    sequence<RtSocketTargetsParameter,1>
+        targets;
+    sequence<PresentationStateParameter,1>
+        initial_state;
+    sequence<AlternatePresentationParameter,1>
+        alternate_presentation1;
+    sequence<AlternatePresentationParameter,1>
+        alternate_presentation2;
+    sequence<AlternatePresentationParameter,1>
+        alternate_presentation3;
+};
+
+// Corresponding MHEG datatype: Orientation-Macro
+//=====
+struct OrientationMacro {
+    MacroDefId
+        macro_def_id;
+    sequence<Orientation,1>
+        orientation;
+};
+
+// Corresponding MHEG datatype: Orientation-Parameter
+//=====
+enum OrientationParameterTag { ORIENTATION_TAG, ORIENTATION_MACRO_TAG };
+union OrientationParameter
+switch (OrientationParameterTag){
+    case ORIENTATION_TAG:
+        Orientation
+            orientation;
+    case ORIENTATION_MACRO_TAG:
+        OrientationMacro
+            orientation_macro;
+};
+
+```
+
+```
+
+// Corresponding MHEG datatype: Set-Slider-Style
+//=====
+struct SetSliderStyle {
+    sequence<RtSocketTargetsParameter,1>
+        targets;
+    sequence<RtSocketTargetParameter,1>
+        cursor;
+    sequence<RtSocketTargetParameter,1>
+        background;
+    sequence<OrientationParameter,1>
+        orientation;
+    sequence<NumericParameter,1>
+        min_value;
+    NumericParameter
+        max_value;
+};
+
+// Corresponding MHEG datatype: Echo-Style-Macro
+//=====
+struct EchoStyleMacro {
+    MacroDefId
+        macro_def_id;
+    sequence<EchoStyle,1>
+        echo_style;
+};
+
+// Corresponding MHEG datatype: Echo-Style-Parameter
+//=====
+enum EchoStyleParameterTag { ECHO_STYLE_MACRO_TAG, ECHO_STYLE_TAG };
+union EchoStyleParameter
+switch (EchoStyleParameterTag){
+    case ECHO_STYLE_MACRO_TAG:
+        EchoStyleMacro
+            echo_style_macro;
+    case ECHO_STYLE_TAG:
+        EchoStyle
+            echo_style;
+};
+
+// Corresponding MHEG datatype: Set-Entry-Field-Style
+//=====
+struct SetEntryFieldStyle {
+    sequence<RtSocketTargetsParameter,1>
+        targets;
+    sequence<EchoStyleParameter,1>
+        echo;
+    sequence<RtSocketTargetParameter,1>
+        background;
+};
+
+// Corresponding MHEG datatype: Association-Macro
+//=====
+struct AssociationMacro {
+    MacroDefId
+        macro_def_id;
+    sequence<Association,1>
+        association;
+};
+
+// Corresponding MHEG datatype: Association-Parameter
+//=====
+enum AssociationParameterTag { ASSOCIATION_TAG, ASSOCIATION_MACRO_TAG };
+union AssociationParameter
+switch (AssociationParameterTag){
+    case ASSOCIATION_TAG:
+        Association
+            association;
+    case ASSOCIATION_MACRO_TAG:
+        AssociationMacro
+            association_macro;
+};
+
+```
+
+```
+
+// Corresponding MHEG datatype: Set-Menu-Style
+//=====
+struct SetMenuStyle {
+    sequence<RtSocketTargetsParameter,1>
+        targets;
+    sequence<OrientationParameter,1>
+        upper_menu_orientation;
+    sequence<AssociationParameter>
+        associations;
+};
+
+// Corresponding MHEG datatype: Socket-Tail-Macro
+//=====
+struct SocketTailMacro {
+    MacroDefId
+        macro_def_id;
+    sequence<SocketTail,1>
+        socket_tail;
+};
+
+// Corresponding MHEG datatype: Socket-Tail-Parameter
+//=====
+enum SocketTailParameterTag { SOCKET_TAIL_TAG, SOCKET_TAIL_MACRO_TAG };
+union SocketTailParameter
+switch (SocketTailParameterTag){
+    case SOCKET_TAIL_TAG:
+        SocketTail
+            socket_tail;
+    case SOCKET_TAIL_MACRO_TAG:
+        SocketTailMacro
+            socket_tail_macro;
+};
+
+// Corresponding MHEG datatype: Separator-Macro
+//=====
+struct SeparatorMacro {
+    MacroDefId
+        macro_def_id;
+    sequence<Separator,1>
+        separator;
+};
+
+// Corresponding MHEG datatype: Separator-Parameter
+//=====
+enum SeparatorParameterTag { SEPARATOR_MACRO_TAG, SEPARATOR_TAG };
+union SeparatorParameter
+switch (SeparatorParameterTag){
+    case SEPARATOR_MACRO_TAG:
+        SeparatorMacro
+            separator_macro;
+    case SEPARATOR_TAG:
+        Separator
+            separator;
+};
+
+// Corresponding MHEG datatype: Slider-Side-Macro
+//=====
+struct SliderSideMacro {
+    MacroDefId
+        macro_def_id;
+    sequence<SliderSide,1>
+        slider_side;
+};
+
+// Corresponding MHEG datatype: Slider-Side-Parameter
+//=====
+enum SliderSideParameterTag { SLIDER_SIDE_TAG, SLIDER_SIDE_MACRO_TAG };
+union SliderSideParameter
+switch (SliderSideParameterTag){
+    case SLIDER_SIDE_TAG:
+        SliderSide
+            slider_side;
+
+```
+
+```
+
+        case SLIDER_SIDE_MACRO_TAG:
+            SliderSideMacro
+                slider_side_macro;
+};
+
+// Corresponding MHEG datatype: Set-Slider-Style-Macro
+//=====
+struct SetSliderStyleMacro {
+    MacroDefId
+        macro_def_id;
+    sequence<SetSliderStyle,1>
+        set_slider_style;
+};
+
+// Corresponding MHEG datatype: Set-Slider-Style-Parameter
+//=====
+enum SetSliderStyleParameterTag { SET_SLIDER_STYLE_MACRO_TAG,
+SET_SLIDER_STYLE_ACTION_TAG };
+union SetSliderStyleParameter
+switch (SetSliderStyleParameterTag){
+    case SET_SLIDER_STYLE_MACRO_TAG:
+        SetSliderStyleMacro
+            set_slider_style_macro;
+    case SET_SLIDER_STYLE_ACTION_TAG:
+        SetSliderStyle
+            set_slider_style_action;
+};
+
+// Corresponding MHEG datatype: Set-Scrolling-List-Style
+//=====
+struct SetScrollingListStyle {
+    sequence<RtSocketTargetsParameter,1>
+        targets;
+    sequence<RtSocketTargetParameter,1>
+        background;
+    sequence<NumericParameter,1>
+        visible_items_number;
+    sequence<SocketTailParameter,1>
+        first_item;
+    sequence<SeparatorParameter,1>
+        separator;
+    sequence<OrientationParameter,1>
+        orientation;
+    sequence<SliderSideParameter,1>
+        slider_side;
+    sequence<SetSliderStyleParameter,1>
+        set_slider_style_action;
+};
+
+// Corresponding MHEG datatype: Original-Def-Declaration-Macro
+//=====
+struct OriginalDefDeclarationMacro {
+    MacroDefId
+        macro_def_id;
+    sequence<OriginalDefDeclaration,1>
+        original_definition;
+};
+
+// Corresponding MHEG datatype: Original-Def-Declaration-Parameter
+//=====
+enum OriginalDefDeclarationParameterTag { ORIGINAL_DEFINITION_TAG,
+ORIGINAL_DEFINITION_MACRO_TAG };
+union OriginalDefDeclarationParameter
+switch (OriginalDefDeclarationParameterTag){
+    case ORIGINAL_DEFINITION_TAG:
+        OriginalDefDeclaration
+            original_definition;
+    case ORIGINAL_DEFINITION_MACRO_TAG:
+        OriginalDefDeclarationMacro
+            original_definition_macro;
+};
+
+```
+
+```
+
+// Corresponding MHEG datatype: New-Channel
+//=====
+struct NewChannel {
+    sequence<ChannelTargetsParameter,1>
+        channel_targets_parameter;
+    sequence<OriginalDefDeclarationParameter,1>
+        original_definition;
+};
+
+// Corresponding MHEG datatype: Channel-Perceptability-Values-Macro
+//=====
+struct ChannelPerceptabilityValueMacro {
+    MacroDefId
+        macro_def_id;
+    sequence<ChannelPerceptabilityValue,1>
+        channel_perceptability_value;
+};
+
+// Corresponding MHEG datatype: Perceptability-Parameter
+//=====
+enum PerceptabilityParameterTag { CHANNEL_PERCEPTABILITY_VALUE_TAG,
+CHANNEL_PERCEPTABILITY_VALUE_MACRO_TAG };
+union PerceptabilityParameter
+switch (PerceptabilityParameterTag){
+    case CHANNEL_PERCEPTABILITY_VALUE_TAG:
+        ChannelPerceptabilityValue
+            channel_perceptability_value;
+    case CHANNEL_PERCEPTABILITY_VALUE_MACRO_TAG:
+        ChannelPerceptabilityValueMacro
+            channel_perceptability_value_macro;
+};
+
+// Corresponding MHEG datatype: Set-Channel-Perceptability
+//=====
+struct SetChannelPerceptability {
+    sequence<ChannelTargetsParameter,1>
+        channel_targets_parameter;
+    sequence<PerceptabilityParameter,1>
+        perceptability_parameter;
+};
+
+// Corresponding MHEG datatype: Elementary-Action
+//=====
+enum ElementaryActionTag { DELAY_TAG, RETURN_TAG, SET_ALIAS_TAG, PREPARE_TAG,
+DESTROY_TAG, ABORT_TAG, SET_DATA_TAG, COPY_TAG, SET_MULTIPLEX_TAG,
+SET_DEMULTIPLEX_TAG, NEW_TAG, DELETE_TAG, SET_GLOBAL_BEHAVIOUR_TAG, RUN_TAG,
+STOP_TAG, SET_PARAMETERS_TAG, PLUG_TAG, SET_RGS_TAG, SET_OPACITY_TAG,
+SET_PRESENTATION_PRIORITY_TAG, SET_VISIBLE_DURATION_TAG,
+SET_TEMPORAL_TERMINATION_TAG, SET_CURRENT_TEMPORAL_POSITION_TAG,
+SET_VISIBLE_DURATION_POSITION_TAG, SET_SPEED_TAG, SET_TIMESTONES_TAG,
+SET_PERCEPTIBLE_SIZE_PROJECTION_TAG, SET_RESIZING_STRATEGY_TAG,
+SET_ASPECT_RATIO_PRESERVED_TAG, SET_VISIBLE_SIZE_TAG,
+SET_VISIBLE_SIZES_ADJUSTMENT_TAG, SET_BOX_TAG, SET_DEFAULT_BACKGROUND_TAG,
+SET_ATTACHMENT_POINT_TAG, SET_ATTACHMENT_POINT_POSITION_TAG,
+SET_VISIBLE_SIZES_ALIGNMENT_TAG, SET_MOVING_ABILITY_TAG,
+SET_RESIZING_ABILITY_TAG, SET_SCALING_ABILITY_TAG, SET_SCROLLING_ABILITY_TAG,
+SET_AUDIBLE_VOLUME_TAG, SET_AUDIBLE_COMPOSITION_EFFECT_TAG,
+SET_STREAM_CHOICE_TAG, SET_SELECTABILITY_TAG, SET_SELECTION_STATUS_TAG,
+SET_SELECTION_PRESENTATION_EFFECT_RESPONSIBILITY_TAG, SET_MODIFIABILITY_TAG,
+SET_MODIFICATION_STATUS_TAG,
+SET_MODIFICATION_PRESENTATION_EFFECT_RESPONSIBILITY_TAG, SET_BUTTON_STYLE_TAG,
+SET_SLIDER_STYLE_TAG, SET_ENTRY_FIELD_STYLE_TAG, SET_MENU_STYLE_TAG,
+SET_SCROLLING_LIST_STYLE_TAG, SET_NO_STYLE_TAG, NEW_CHANNEL_TAG,
+DELETE_CHANNEL_TAG, SET_CHANNEL_PERCEPTABILITY_TAG };
+union ElementaryAction
+switch (ElementaryActionTag){
+    case DELAY_TAG:
+        Delay
+            delay;
+    case RETURN_TAG:
+        Return
+            return;
+};
+
+```
+
+```
+
+case SET_ALIAS_TAG:
+    SetAlias
+        set_alias;
+case PREPARE_TAG:
+    sequence<MhTargetsParameter,1>
+        prepare;
+case DESTROY_TAG:
+    sequence<MhTargetsParameter,1>
+        destroy;
+case ABORT_TAG:
+    sequence<MhTargetsParameter,1>
+        abort;
+case SET_DATA_TAG:
+    SetData
+        set_data;
+case COPY_TAG:
+    Copy
+        copy;
+case SET_MULTIPLEX_TAG:
+    SetMultiplex
+        set_multiplex;
+case SET_DEMULTIPLEX_TAG:
+    SetDemultiplex
+        set_demultiplex;
+case NEW_TAG:
+    sequence<RtTargetsParameter,1>
+        new;
+case DELETE_TAG:
+    sequence<RtTargetsParameter,1>
+        delete;
+case SET_GLOBAL_BEHAVIOUR_TAG:
+    SetGlobalBehaviour
+        set_global_behaviour;
+case RUN_TAG:
+    sequence<RtSocketTargetsParameter,1>
+        run;
+case STOP_TAG:
+    sequence<RtSocketTargetsParameter,1>
+        stop;
+case SET_PARAMETERS_TAG:
+    SetParameters
+        set_parameters;
+case PLUG_TAG:
+    Plug
+        plug;
+case SET_RGS_TAG:
+    SetRGS
+        set_RGS;
+case SET_OPACITY_TAG:
+    SetOpacity
+        set_opacity;
+case SET_PRESENTATION_PRIORITY_TAG:
+    SetPresentationPriority
+        set_presentation_priority;
+case SET_VISIBLE_DURATION_TAG:
+    SetVisibleDuration
+        set_visible_duration;
+case SET_TEMPORAL_TERMINATION_TAG:
+    SetTemporalTermination
+        set_temporal_termination;
+case SET_CURRENT_TEMPORAL_POSITION_TAG:
+    SetCurrentTemporalPosition
+        set_current_temporal_position;
+case SET_VISIBLE_DURATION_POSITION_TAG:
+    SetVisibleDurationPosition
+        set_visible_duration_position;
+case SET_SPEED_TAG:
+    SetSpeed
+        set_speed;
+case SET_TIMESTONES_TAG:
+    SetTimestones
+        set_timestones;
+
+```
+
+```
+
+case SET_PERCEPTIBLE_SIZE_PROJECTION_TAG:
+    SetPerceptibleSizeProjection
+        set_perceptible_size_projection;
+case SET_RESIZING_STRATEGY_TAG:
+    SetResizingStrategy
+        set_resizing_strategy;
+case SET_ASPECT_RATIO_PRESERVED_TAG:
+    SetAspectRatioPreserved
+        set_aspect_ratio_preserved;
+case SET_VISIBLE_SIZE_TAG:
+    SetVisibleSize
+        set_visible_size;
+case SET_VISIBLE_SIZES_ADJUSTMENT_TAG:
+    SetVisibleSizesAdjustment
+        set_visible_sizes_adjustment;
+case SET_BOX_TAG:
+    SetBox
+        set_box;
+case SET_DEFAULT_BACKGROUND_TAG:
+    SetDefaultBackground
+        set_default_background;
+case SET_ATTACHMENT_POINT_TAG:
+    SetAttachmentPoint
+        set_attachment_point;
+case SET_ATTACHMENT_POINT_POSITION_TAG:
+    SetAttachmentPointPosition
+        set_attachment_point_position;
+case SET_VISIBLE_SIZES_ALIGNMENT_TAG:
+    SetVisibleSizesAlignment
+        set_visible_sizes_alignment;
+case SET_MOVING_ABILITY_TAG:
+    SetMovingAbility
+        set_moving_ability;
+case SET_RESIZING_ABILITY_TAG:
+    SetResizingAbility
+        set_resizing_ability;
+case SET_SCALING_ABILITY_TAG:
+    SetScalingAbility
+        set_scaling_ability;
+case SET_SCROLLING_ABILITY_TAG:
+    SetScrollingAbility
+        set_scrolling_ability;
+case SET_AUDIBLE_VOLUME_TAG:
+    SetAudibleVolume
+        set_audible_volume;
+case SET_AUDIBLE_COMPOSITION_EFFECT_TAG:
+    SetAudibleCompositionEffect
+        set_audible_composition_effect;
+case SET_STREAM_CHOICE_TAG:
+    SetStreamChoice
+        set_stream_choice;
+case SET_SELECTABILITY_TAG:
+    SetSelectability
+        set_selectability;
+case SET_SELECTION_STATUS_TAG:
+    SetSelectionStatus
+        set_selection_status;
+case SET_SELECTION_PRESENTATION_EFFECT_RESPONSIBILITY_TAG:
+    SetSelectionPresentationEffectResponsibility
+        set_selection_presentation_effect_responsibility;
+case SET_MODIFIABILITY_TAG:
+    SetModifiability
+        set_modifiability;
+case SET_MODIFICATION_STATUS_TAG:
+    SetModificationStatus
+        set_modification_status;
+case SET_MODIFICATION_PRESENTATION_EFFECT_RESPONSIBILITY_TAG:
+    SetModificationPresentationEffectResponsibility
+        set_modification_presentation_effect_responsibility;
+case SET_BUTTON_STYLE_TAG:
+    SetButtonStyle
+        set_button_style;
+
+```
+
+```
+
+case SET_SLIDER_STYLE_TAG:
+    SetSliderStyle
+        set_slider_style;
+case SET_ENTRY_FIELD_STYLE_TAG:
+    SetEntryFieldStyle
+        set_entry_field_style;
+case SET_MENU_STYLE_TAG:
+    SetMenuStyle
+        set_menu_style;
+case SET_SCROLLING_LIST_STYLE_TAG:
+    SetScrollingListStyle
+        set_scrolling_list_style;
+case SET_NO_STYLE_TAG:
+    sequence<RtSocketTargetsParameter,1>
+        set_no_style;
+case NEW_CHANNEL_TAG:
+    NewChannel
+        new_channel;
+case DELETE_CHANNEL_TAG:
+    sequence<ChannelTargetsParameter,1>
+        delete_channel;
+case SET_CHANNEL_PERCEPTABILITY_TAG:
+    SetChannelPerceptability
+        set_channel_perceptability;
+};
+
+// Corresponding MHEG datatype: Keywords
+//=====
+typedef sequence<string> Keywords;
+
+// Corresponding MHEG datatype: Description
+//=====
+struct Description {
+    sequence<string,1>
+        name;
+    sequence<string,1>
+        owner;
+    sequence<string,1>
+        version;
+    sequence<string,1>
+        date;
+    sequence<Keywords,1>
+        keywords;
+    sequence<string,1>
+        copyright;
+    sequence<string,1>
+        licence;
+    sequence<string,1>
+        comment;
+};
+
+// Corresponding MHEG datatype: Class-Identifier
+//=====
+enum ClassIdentifier {
+    ACTION_CLASS,
+    LINK_CLASS,
+    SCRIPT_CLASS,
+    CONTENT_CLASS,
+    MULTIPLEXED_CONTENT_CLASS,
+    COMPOSITE_CLASS,
+    CONTAINER_CLASS,
+    DESCRIPTOR_CLASS
+};
+
+// Corresponding MHEG datatype: OBJECTIDENTIFIER
+//=====
+struct OBJECTIDENTIFIER {
+    unsigned short root;
+    unsigned short arc1;
+    unsigned short arc2;
+    unsigned short arc3;
+};
+
+```
+
+```
+
+// Corresponding MHEG datatype: Synchro-Indicator
+//=====
+enum SynchroIndicator {
+    SERIAL,
+    PARALLEL
+};
+
+// Corresponding MHEG datatype: Synchro-Indicator-Macro
+//=====
+struct SynchroIndicatorMacro {
+    MacroDefId
+        macro_def_id;
+    sequence<SynchroIndicator,1>
+        synchro_indicator;
+};
+
+// Corresponding MHEG datatype: Synchro-Indicator-Parameter
+//=====
+enum SynchroIndicatorParameterTag { SYNCHRO_INDICATOR_TAG,
+SYNCHRO_INDICATOR_MACRO_TAG };
+union SynchroIndicatorParameter
+switch (SynchroIndicatorParameterTag){
+    case SYNCHRO_INDICATOR_TAG:
+        SynchroIndicator
+            synchro_indicator;
+    case SYNCHRO_INDICATOR_MACRO_TAG:
+        SynchroIndicatorMacro
+            synchro_indicator_macro;
+};
+
+// Corresponding MHEG datatype: Performances
+//=====
+typedef long Performances;
+
+// Corresponding MHEG datatype: Performances-Macro
+//=====
+struct PerformancesMacro {
+    MacroDefId
+        macro_def_id;
+    sequence<Performances,1>
+        performances;
+};
+
+// Corresponding MHEG datatype: Performances-Parameter
+//=====
+enum PerformancesParameterTag { PERFORMANCES_TAG, PERFORMANCES_MACRO_TAG };
+union PerformancesParameter
+switch (PerformancesParameterTag){
+    case PERFORMANCES_TAG:
+        Performances
+            performances;
+    case PERFORMANCES_MACRO_TAG:
+        PerformancesMacro
+            performances_macro;
+};
+
+interface ActionClass;
+
+// Corresponding MHEG datatype: Action
+//=====
+enum ActionTag { ACTION_REFERENCE_TAG, ACTION_CLASS_TAG };
+union Action
+switch (ActionTag){
+    case ACTION_REFERENCE_TAG:
+        MhObjectReference
+            action_reference;
+    case ACTION_CLASS_TAG:
+        ActionClass
+            action_class;
+};
+
+// Corresponding MHEG datatype: Synchronized-Action
+//=====
+enum SynchronizedActionTag { ELEMENTARY_ACTION_TAG, ACTION_TAG };
+
+```
+
+```
+
+union SynchronizedAction
+switch (SynchronizedActionTag){
+    case ELEMENTARY_ACTION_TAG:
+        ElementaryAction
+            elementary_action;
+    case ACTION_TAG:
+        Action
+            action;
+};
+
+// Corresponding MHEG datatype: Action-Class
+//=====
+interface ActionClass {
+attribute OBJECTIDENTIFIER
+    object_identification;
+attribute sequence<MHEGIdentifier,1>
+    mheg_identifier;
+attribute sequence<Description,1>
+    the_description;
+attribute sequence<SynchroIndicatorParameter,1>
+    synchro_indicator_parameter;
+attribute sequence<TargetsParameter,1>
+    target_set_parameter;
+attribute sequence<PerformancesParameter,1>
+    performances_parameter;
+attribute sequence<SynchronizedAction>
+    synchronized_actions;
+};
+
+// Corresponding MHEG datatype: Logical-Operator
+//=====
+enum LogicalOperator {
+    AND,
+    OR,
+    XOR,
+    NAND,
+    NOR,
+    NXOR
+};
+
+// Corresponding MHEG datatype: Comparison-Operator
+//=====
+enum ComparisonOperator {
+    EQUAL,
+    NOT_EQUAL,
+    GREATER,
+    GREATER_EQUAL,
+    LESS,
+    LESS_EQUAL
+};
+
+// Corresponding MHEG datatype: Comparison-Value
+//=====
+enum ComparisonValueTag { COMPARISON_VALUE_GENERIC_VALUE_TAG,
+COMPARISON_VALUE_COMPARISON_VALUE_CONSTANT_TAG };
+union ComparisonValue
+switch (ComparisonValueTag){
+    case COMPARISON_VALUE_GENERIC_VALUE_TAG:
+        GenericValue
+            generic_value;
+    case COMPARISON_VALUE_COMPARISON_VALUE_CONSTANT_TAG:
+        ComparisonValueConstant
+            comparison_value_constant;
+};
+
+// Corresponding MHEG datatype: Evaluated-Condition
+//=====
+struct EvaluatedCondition {
+    ComparisonOperator
+        comparison_operator;
+    ComparisonValue
+        comparison_value;
+};
+
+```
+
+```
+
+// Corresponding MHEG datatype: Previous-Condition
+//=====
+enum PreviousConditionTag { EVALUATED_CONDITION_TAG, NEGATION_TAG };
+union PreviousCondition
+switch (PreviousConditionTag){
+    case EVALUATED_CONDITION_TAG:
+        EvaluatedCondition
+            evaluated_condition;
+};
+
+// Corresponding MHEG datatype: Generic-Condition
+//=====
+struct GenericCondition {
+    EvaluatedValue
+        source_value;
+    sequence<PreviousCondition,1>
+        previous_condition;
+    EvaluatedCondition
+        current_condition;
+};
+
+// Corresponding MHEG datatype: Link-Condition
+//=====
+enum LinkConditionTag { LOGICAL_COMBINATION_TAG, GENERIC_CONDITION_TAG };
+union LinkCondition
+switch (LinkConditionTag){
+    case LOGICAL_COMBINATION_TAG:
+        struct LogicalCombination {
+            sequence<LogicalOperator,1>
+                logical_operator;
+            sequence<LinkCondition>
+                conditions;
+        } logical_combination;
+    case GENERIC_CONDITION_TAG:
+        GenericCondition
+            generic_condition;
+};
+
+// Corresponding MHEG datatype: Macro-Resolution-Parameter
+//=====
+struct MacroResolutionParameter {
+    MacroDefId
+        macro_def_id;
+    sequence<GenericValue,1>
+        usage_value;
+};
+
+// Corresponding MHEG datatype: Link-Effect
+//=====
+struct LinkEffect {
+    sequence<sequence<MacroResolutionParameter>,1>
+        macro_resolution;
+    Action
+        action;
+};
+
+// Corresponding MHEG datatype: Link-Class
+//=====
+interface LinkClass {
+attribute OBJECTIDENTIFIER
+    object_identification;
+attribute sequence<MHEGIdentifier,1>
+    mheg_identifier;
+attribute sequence<Description,1>
+    the_description;
+attribute sequence<LinkCondition,1>
+    link_condition;
+attribute LinkEffect
+    link_effect;
+};
+
+// Corresponding MHEG datatype: Script-Inclusion
+//=====
+enum ScriptInclusionTag { OCTETSTRING_TAG, BITSTRING_TAG };
+union ScriptInclusion
+
+```
+
+```
+
+switch (ScriptInclusionTag){
+    case OCTETSTRING_TAG:
+        string
+            octetstring;
+    case BITSTRING_TAG:
+        string
+            bitstring;
+};
+
+// Corresponding MHEG datatype: Script-Data
+//=====
+enum ScriptDataTag { SCRIPT_INCLUSION_TAG, DATA_REFERENCE_TAG };
+union ScriptData
+switch (ScriptDataTag){
+    case SCRIPT_INCLUSION_TAG:
+        ScriptInclusion
+            script_inclusion;
+    case DATA_REFERENCE_TAG:
+        DataReference
+            data_reference;
+};
+
+// Corresponding MHEG datatype: Script-Class
+//=====
+interface ScriptClass {
+attribute OBJECTIDENTIFIER
+    object_identification;
+attribute sequence<MHEGIdentifier,1>
+    mheg_identifier;
+attribute sequence<Description,1>
+    the_description;
+attribute sequence<ScriptClassification,1>
+    script_classification;
+attribute ScriptHook
+    script_hook_information;
+attribute ScriptData
+    script_data;
+};
+
+// Corresponding MHEG datatype: Data-Inclusion
+//=====
+enum DataInclusionTag { DATA_INCLUSION_OCTET_STRING_TAG,
+DATA_INCLUSION_BIT_STRING_TAG };
+union DataInclusion
+switch (DataInclusionTag){
+    case DATA_INCLUSION_OCTET_STRING_TAG:
+        string
+            octet_string;
+    case DATA_INCLUSION_BIT_STRING_TAG:
+        string
+            bit_string;
+};
+
+// Corresponding MHEG datatype: Content-Data
+//=====
+enum ContentDataTag { CONTENT_DATA_DATA_INCLUSION_TAG,
+CONTENT_DATA_DATA_REFERENCE_TAG };
+union ContentData
+switch (ContentDataTag){
+    case CONTENT_DATA_DATA_INCLUSION_TAG:
+        DataInclusion
+            data_inclusion;
+    case CONTENT_DATA_DATA_REFERENCE_TAG:
+        DataReference
+            data_reference;
+};
+
+// Corresponding MHEG datatype: Content-Class
+//=====
+interface ContentClass {
+attribute OBJECTIDENTIFIER
+    object_identification;
+
+```
+
+```
+
+attribute MHEGIdentifier
+    mheg_identifier;
+attribute Description
+    the_description;
+attribute ContentClassification
+    classification;
+attribute OriginalPerception
+    original_perception;
+attribute ContentHook
+    content_hook;
+attribute ContentData
+    content_data;
+};
+
+// Corresponding MHEG datatype: Multiplexed-Stream
+//=====
+struct MultiplexedStream {
+    sequence<sequence<long>,1>
+        stream_identifier;
+    sequence<ContentClassification,1>
+        stream_classification;
+    sequence<OriginalPerception,1>
+        stream_original_perception;
+    ContentHook
+        hook_stream;
+};
+
+// Corresponding MHEG datatype: Multiplexed-Content-Class
+//=====
+interface MultiplexedContentClass {
+attribute OBJECTIDENTIFIER
+    object_identification;
+attribute sequence<MHEGIdentifier,1>
+    mheg_identifier;
+attribute sequence<Description,1>
+    the_description;
+attribute sequence<ContentClassification,1>
+    mux_classification;
+attribute sequence<OriginalPerception,1>
+    original_perception;
+attribute ContentHook
+    mux_hook;
+attribute ContentData
+    mux_data;
+attribute sequence<sequence<MultiplexedStream>,1>
+    multiplexed_streams;
+};
+
+// Corresponding MHEG datatype: Link
+//=====
+enum LinkTag { LINK_REFERENCE_TAG, LINK_CLASS_TAG };
+union Link
+switch (LinkTag){
+    case LINK_REFERENCE_TAG:
+        MhObjectReference
+            mh_object_reference;
+    case LINK_CLASS_TAG:
+        LinkClass
+            link;
+};
+
+// Corresponding MHEG datatype: Specific-Behaviour
+//=====
+enum SpecificBehaviourTag { ACTIONS_TAG, LINKS_TAG };
+union SpecificBehaviour
+switch (SpecificBehaviourTag){
+    case ACTIONS_TAG:
+        sequence<Action>
+            actions;
+    case LINKS_TAG:
+        sequence<Link>
+            links;
+};
+
+```
+
+```
+
+// Corresponding MHEG datatype: Availability-Start-Up
+// Corresponding MHEG datatype: Availability-Close-Down
+// Corresponding MHEG datatype: Rt-Availability-Start-Up
+//=====
+enum PredefinedBehaviourTag { PREDEFINED_BEHAVIOUR_LINK_CLASS_TAG,
+PREDEFINED_BEHAVIOUR_INHIBIT_TAG };
+union PredefinedBehaviour
+switch (PredefinedBehaviourTag){
+    case PREDEFINED_BEHAVIOUR_LINK_CLASS_TAG:
+        LinkClass
+            link_class;
+};
+
+// Corresponding MHEG datatype: Predefined-Behaviour
+//=====
+struct PredefinedBehaviours {
+    sequence<PredefinedBehaviour,1>
+        availability_start_up;
+    sequence<PredefinedBehaviour,1>
+        availability_close_down;
+    sequence<PredefinedBehaviour,1>
+        rt_availability_start_up;
+    sequence<LinkClass,1>
+        rt_availability_close_down;
+};
+
+// Corresponding MHEG datatype: Composition-Behaviour
+//=====
+struct CompositionBehaviour {
+    PredefinedBehaviours
+        predefined_behaviours;
+    SpecificBehaviour
+        specific_behaviour;
+};
+
+interface CompositeClass;
+
+// Corresponding MHEG datatype: Component
+//=====
+enum ComponentTag { MH_OBJECT_REFERENCE_TAG, CONTENT_TAG,
+MULTIPLEXED_CONTENT_TAG, COMPOSITE_TAG };
+union Component
+switch (ComponentTag){
+    case MH_OBJECT_REFERENCE_TAG:
+        MhObjectReference
+            mh_object_reference;
+    case CONTENT_TAG:
+        ContentClass
+            content;
+    case MULTIPLEXED_CONTENT_TAG:
+        MultiplexedContentClass
+            multiplexed_content;
+    case COMPOSITE_TAG:
+        CompositeClass
+            composite;
+};
+
+// Corresponding MHEG datatype: Associated-Model
+//=====
+enum AssociatedModelTag { ASSOCIATED_MODEL_COMPONENT_TAG,
+ASSOCIATED_MODEL_ASSOCIATED_LABEL_TAG };
+union AssociatedModel
+switch (AssociatedModelTag){
+    case ASSOCIATED_MODEL_COMPONENT_TAG:
+        Component
+            component;
+    case ASSOCIATED_MODEL_ASSOCIATED_LABEL_TAG:
+        string
+            associated_label;
+};
+
+```
+
+```
+
+// Corresponding MHEG datatype: Element
+//=====
+struct Element {
+    long
+        element_index;
+    AssociatedModel
+        associated_model;
+};
+
+// Corresponding MHEG datatype: Composition
+//=====
+struct Composition {
+    long
+        nb_elements;
+    sequence<Element>
+        elements;
+};
+
+// Corresponding MHEG datatype: Composite-Class
+//=====
+interface CompositeClass {
+attribute OBJECTIDENTIFIER
+    object_identification;
+attribute sequence<MHEGIdentifier,1>
+    mheg_identifier;
+attribute sequence<Description,1>
+    the_description;
+attribute sequence<CompositionBehaviour,1>
+    composition_behaviour;
+attribute sequence<OriginalPerception,1>
+    original_perception;
+attribute Composition
+    elements;
+};
+
+// Corresponding MHEG datatype: Container-Default-Behaviour
+//=====
+struct ContainerDefaultBehaviour {
+    sequence<PredefinedBehaviour,1>
+        availability_start_up;
+    sequence<PredefinedBehaviour,1>
+        availability_close_down;
+};
+
+interface ContainerClass;
+interface DescriptorClass;
+
+// Corresponding MHEG datatype: Mh-Element
+//=====
+enum MhElementTag { MH_ELEMENT_MH_OBJECT_REFERENCE_TAG, MH_ELEMENT_ACTION_TAG,
+MH_ELEMENT_LINK_TAG, MH_ELEMENT_SCRIPT_TAG, MH_ELEMENT_CONTENT_TAG,
+MH_ELEMENT_MUX_CONTENT_TAG, MH_ELEMENT_COMPOSITE_TAG, MH_ELEMENT_CONTAINER_TAG,
+MH_ELEMENT_DESCRIPTOR_TAG };
+union MhElement
+switch (MhElementTag){
+    case MH_ELEMENT_MH_OBJECT_REFERENCE_TAG:
+        MhObjectReference
+            mh_object_reference;
+    case MH_ELEMENT_ACTION_TAG:
+        ActionClass
+            action;
+    case MH_ELEMENT_LINK_TAG:
+        LinkClass
+            link;
+    case MH_ELEMENT_SCRIPT_TAG:
+        ScriptClass
+            script;
+    case MH_ELEMENT_CONTENT_TAG:
+        ContentClass
+            content;
+    case MH_ELEMENT_MUX_CONTENT_TAG:
+        MultiplexedContentClass
+            mux_content;
+
+```
+
+```
+
+    case MH_ELEMENT_COMPOSITE_TAG:
+        CompositeClass
+            composite;
+    case MH_ELEMENT_CONTAINER_TAG:
+        ContainerClass
+            container;
+    case MH_ELEMENT_DESCRIPTOR_TAG:
+        DescriptorClass
+            descriptor;
+};
+
+// Corresponding MHEG datatype: Container-Class
+//=====
+interface ContainerClass {
+attribute OBJECTIDENTIFIER
+    object_identification;
+attribute sequence<MHEGIdentifier,1>
+    mheg_identifier;
+attribute sequence<Description,1>
+    the_description;
+attribute ContainerDefaultBehaviour
+    container_default_behaviour;
+attribute sequence<MhElement>
+    container_elements;
+};
+
+// Corresponding MHEG datatype: Delay-Bounds
+//=====
+struct DelayBounds {
+    long
+        lower_value;
+    long
+        upper_value;
+};
+
+// Corresponding MHEG datatype: Degradation
+//=====
+enum Degradation {
+    GUARANTEED,
+    BEST_EFFORT,
+    NOT_GUARANTEED
+};
+
+// Corresponding MHEG datatype: Quality-Of-Service
+//=====
+struct QualityOfService {
+    sequence<Degradation,1>
+        degradation;
+    sequence<boolean,1>
+        reliability;
+    sequence<DelayBounds,1>
+        delay_bounds;
+    sequence<long,1>
+        jitter_bounds;
+};
+
+// Corresponding MHEG datatype: Script-Class-Information
+//=====
+struct ScriptClassInformation {
+    sequence<ScriptClassification,1>
+        script_classification;
+    sequence<ScriptHook,1>
+        script_hook;
+};
+
+// Corresponding MHEG datatype: Alternative-Object
+//=====
+struct AlternativeObject {
+    MhObjectReference
+        content_or_mux_object;
+    sequence<ContentHook,1>
+        alternative_hook;
+    sequence<MhObjectReference,1>
+        alternative_descriptor;
+};
+
+```
+
+```
+
+        sequence<string,1>
+            alternative_keyword;
+};
+
+// Corresponding MHEG datatype: Content-Class-Information
+//=====
+struct ContentClassInformation {
+    sequence<ContentClassification,1>
+        content_classification;
+    sequence<ContentHook,1>
+        content_hook;
+    sequence<sequence<AlternativeObject>,1>
+        alternative_object;
+};
+
+// Corresponding MHEG datatype: Stream-Information
+//=====
+struct StreamInformation {
+    sequence<StreamIdentifier,1>
+        stream_identifier;
+    sequence<ContentClassInformation,1>
+        content_class_information;
+};
+
+// Corresponding MHEG datatype: Multiplexed-Content-Class-Information
+//=====
+struct MultiplexedContentClassInformation {
+    sequence<ContentClassification,1>
+        multiplexed_content_classification;
+    sequence<ContentHook,1>
+        multiplexed_content_hook;
+    sequence<long,1>
+        stream_number;
+    sequence<sequence<StreamInformation>,1>
+        stream_information;
+    sequence<sequence<AlternativeObject>,1>
+        alternative_object;
+};
+
+// Corresponding MHEG datatype: Class-Specific
+//=====
+enum ClassSpecificTag { SCRIPT_CLASS_INFORMATION_TAG,
+CONTENT_CLASS_INFORMATION_TAG, MULTIPLEXED_CONTENT_CLASS_INFORMATION_TAG };
+union ClassSpecific
+switch (ClassSpecificTag){
+    case SCRIPT_CLASS_INFORMATION_TAG:
+        ScriptClassInformation
+            script_class_information;
+    case CONTENT_CLASS_INFORMATION_TAG:
+        ContentClassInformation
+            content_class_information;
+    case MULTIPLEXED_CONTENT_CLASS_INFORMATION_TAG:
+        MultiplexedContentClassInformation
+            multiplexed_content_class_information;
+};
+
+// Corresponding MHEG datatype: Object-Information
+//=====
+struct ObjectInformation {
+    sequence<long,1>
+        object_size;
+    sequence<ClassIdentifier,1>
+        class_identifier;
+    sequence<ClassSpecific,1>
+        class_specific;
+    sequence<QualityOfService,1>
+        quality_of_service;
+};
+
+// Corresponding MHEG datatype: Related-Object
+//=====
+struct RelatedObject {
+    MhObjectReference
+        object_reference;
+};
+
+```
+
+```
+
+sequence<ObjectInformation,1>
+    object_information;
+};
+
+// Corresponding MHEG datatype: System-Readable-Material
+//=====
+enum SystemReadableMaterialTag { SYSTEM_READABLE_MATERIAL_BITSTRING_TAG,
+SYSTEM_READABLE_MATERIAL_OCTETSTRING_TAG };
+union SystemReadableMaterial
+switch (SystemReadableMaterialTag){
+    case SYSTEM_READABLE_MATERIAL_BITSTRING_TAG:
+        string
+            bitstring;
+    case SYSTEM_READABLE_MATERIAL_OCTETSTRING_TAG:
+        string
+            octetstring;
+};
+
+// Corresponding MHEG datatype: General-Information
+//=====
+struct GeneralInformation {
+    sequence<string,1>
+        readme;
+    sequence<SystemReadableMaterial,1>
+        system_readable_material;
+};
+
+// Corresponding MHEG datatype: Media-Type
+//=====
+enum MediaType {
+    AUDIBLE,
+    LEFT_AUDIBLE,
+    RIGHT_AUDIBLE,
+    VISIBLE
+};
+
+// Corresponding MHEG datatype: Predefined-Selection-Mode
+//=====
+enum PredefinedSelectionMode {
+    MOUSE_BUTTON_1_DOWN,
+    MOUSE_BUTTON_2_DOWN,
+    MOUSE_BUTTON_3_DOWN,
+    MOUSE_BUTTONS_1_2_DOWN,
+    MOUSE_BUTTONS_1_3_DOWN,
+    MOUSE_BUTTONS_2_3_DOWN,
+    MOUSE_BUTTON_1_UP,
+    MOUSE_BUTTON_2_UP,
+    MOUSE_BUTTON_3_UP,
+    MOUSE_BUTTONS_1_2_UP,
+    MOUSE_BUTTONS_1_3_UP,
+    MOUSE_BUTTONS_2_3_UP,
+    MOUSE_SINGLE_CLICK_ON_BUTTON_1,
+    MOUSE_SINGLE_CLICK_ON_BUTTON_2,
+    MOUSE_SINGLE_CLICK_ON_BUTTON_3,
+    MOUSE_SINGLE_CLICK_ON_BUTTONS_12,
+    MOUSE_SINGLE_CLICK_ON_BUTTONS_13,
+    MOUSE_SINGLE_CLICK_ON_BUTTONS_23,
+    MOUSE_DOUBLE_CLICK_ON_BUTTON_1,
+    MOUSE_DOUBLE_CLICK_ON_BUTTON_2,
+    MOUSE_DOUBLE_CLICK_ON_BUTTON_3,
+    MOUSE_DOUBLE_CLICK_ON_BUTTONS_12,
+    MOUSE_DOUBLE_CLICK_ON_BUTTONS_13,
+    MOUSE_DOUBLE_CLICK_ON_BUTTONS_23,
+    MOUSE_TRIPLE_CLICK_ON_BUTTON_1,
+    MOUSE_TRIPLE_CLICK_ON_BUTTON_2,
+    MOUSE_TRIPLE_CLICK_ON_BUTTON_3,
+    MOUSE_TRIPLE_CLICK_ON_BUTTONS_12,
+    MOUSE_TRIPLE_CLICK_ON_BUTTONS_13,
+    MOUSE_TRIPLE_CLICK_ON_BUTTONS_23,
+    MOUSE_ENTER,
+    MOUSE_LEAVE,
+    MOUSE_POINTER_MOTION,
+
+```
+
+```
+
+    MOUSE_BUTTON_1_MOTION,
+    MOUSE_BUTTON_2_MOTION,
+    MOUSE_BUTTON_3_MOTION,
+    MOUSE_BUTTONS_1_2_MOTION,
+    MOUSE_BUTTONS_1_3_MOTION,
+    MOUSE_BUTTONS_2_3_MOTION,
+    KEY_PRESS,
+    KEY_RELEASE
+};
+
+// Corresponding MHEG datatype: Physical-Selection-Mode
+//=====
+enum PhysicalSelectionModeTag { PRIVATE_MODE_TAG, PREDEFINED_TAG };
+union PhysicalSelectionMode
+switch (PhysicalSelectionModeTag){
+    case PRIVATE_MODE_TAG:
+        long
+            private_mode;
+    case PREDEFINED_TAG:
+        PredefinedSelectionMode
+            predefined;
+};
+
+// Corresponding MHEG datatype: Selection-Mode
+//=====
+struct SelectionMode {
+    long
+        logical_selection_mode;
+    sequence<PhysicalSelectionMode,1>
+        physical_selection_mode;
+};
+
+// Corresponding MHEG datatype: Predefined-Modification-Mode
+//=====
+enum PredefinedModificationMode {
+    MEDIA_EDITOR
+};
+
+// Corresponding MHEG datatype: Physical-Modification-Mode
+//=====
+enum PhysicalModificationModeTag { PHYSICAL_MODIFICATION_MODE_NUMERIC_TAG,
+PHYSICAL_MODIFICATION_MODE_PREDEFINED_TAG };
+union PhysicalModificationMode
+switch (PhysicalModificationModeTag){
+    case PHYSICAL_MODIFICATION_MODE_NUMERIC_TAG:
+        long
+            numeric;
+    case PHYSICAL_MODIFICATION_MODE_PREDEFINED_TAG:
+        PredefinedModificationMode
+            predefined;
+};
+
+// Corresponding MHEG datatype: Modification-Mode
+//=====
+struct ModificationMode {
+    long
+        logical_modification_mode;
+    sequence<PhysicalModificationMode,1>
+        physical_modification_mode;
+};
+
+// Corresponding MHEG datatype: Channel-Information
+//=====
+struct ChannelInformation {
+    sequence<ChannelIdentifier,1>
+        channel_id;
+    sequence<long,1>
+        x_min;
+    sequence<long,1>
+        x_max;
+    sequence<long,1>
+        y_min;
+
+```
+
+```
+
+sequence<long,1>
+    y_max;
+sequence<long,1>
+    z_min;
+sequence<long,1>
+    z_max;
+sequence<long,1>
+    x_granularity;
+sequence<long,1>
+    y_granularity;
+sequence<long,1>
+    z_granularity;
+sequence<long,1>
+    t_granularity;
+sequence<long,1>
+    f_min;
+sequence<long,1>
+    f_max;
+sequence<long,1>
+    audio_dynamic;
+sequence<MediaType,1>
+    media_type;
+sequence<SelectionMode,1>
+    selection_mode;
+sequence<ModificationMode,1>
+    modification_mode;
+};
+
+// Corresponding MHEG datatype: Interaction-Style-Information
+//=====
+enum InteractionStyleInformation {
+    BUTTON,
+    SLIDER,
+    ENTRY_FIELD,
+    MENU,
+    SCROLLING_LIST
+};
+
+// Corresponding MHEG datatype: Descriptor-Class
+//=====
+interface DescriptorClass {
+attribute OBJECTIDENTIFIER
+    object_identification;
+attribute sequence<MHEGIdentifier,1>
+    mheg_identifier;
+attribute sequence<Description,1>
+    the_description;
+attribute sequence<sequence<RelatedObject>,1>
+    related_objects;
+attribute sequence<sequence<MhObjectReference>,1>
+    other_descriptors;
+attribute sequence<GeneralInformation,1>
+    general_information;
+attribute sequence<sequence<ChannelInformation>,1>
+    channel_information;
+attribute sequence<sequence<InteractionStyleInformation>,1>
+    interaction_styles_information;
+};
+
+}; // end of module
+
+```
+
+## ITU-T RECOMMENDATIONS SERIES
+
+|                 |                                                                                                                |
+|-----------------|----------------------------------------------------------------------------------------------------------------|
+| Series A        | Organization of the work of the ITU-T                                                                          |
+| Series B        | Means of expression: definitions, symbols, classification                                                      |
+| Series C        | General telecommunication statistics                                                                           |
+| Series D        | General tariff principles                                                                                      |
+| Series E        | Overall network operation, telephone service, service operation and human factors                              |
+| Series F        | Non-telephone telecommunication services                                                                       |
+| Series G        | Transmission systems and media, digital systems and networks                                                   |
+| Series H        | Audiovisual and multimedia systems                                                                             |
+| Series I        | Integrated services digital network                                                                            |
+| Series J        | Transmission of television, sound programme and other multimedia signals                                       |
+| Series K        | Protection against interference                                                                                |
+| Series L        | Construction, installation and protection of cables and other elements of outside plant                        |
+| Series M        | Maintenance: international transmission systems, telephone circuits, telegraphy, facsimile and leased circuits |
+| Series N        | Maintenance: international sound programme and television transmission circuits                                |
+| Series O        | Specifications of measuring equipment                                                                          |
+| Series P        | Telephone transmission quality, telephone installations, local line networks                                   |
+| Series Q        | Switching and signalling                                                                                       |
+| Series R        | Telegraph transmission                                                                                         |
+| Series S        | Telegraph services terminal equipment                                                                          |
+| <b>Series T</b> | <b>Terminals for telematic services</b>                                                                        |
+| Series U        | Telegraph switching                                                                                            |
+| Series V        | Data communication over the telephone network                                                                  |
+| Series X        | Data networks and open system communication                                                                    |
+| Series Z        | Programming languages                                                                                          |
\ No newline at end of file
diff --git a/marked/T/T-REC-T.180-199806-I_PDF-E/raw.md b/marked/T/T-REC-T.180-199806-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..be7ba93eb9b98840c3d0f9b7a8b5482db86543d2
--- /dev/null
+++ b/marked/T/T-REC-T.180-199806-I_PDF-E/raw.md
@@ -0,0 +1,11250 @@
+
+
+![ITU logo: a globe with the letters ITU inside, crossed by a lightning bolt.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg)
+
+ITU logo: a globe with the letters ITU inside, crossed by a lightning bolt.
+
+INTERNATIONAL TELECOMMUNICATION UNION
+
+# ITU-T
+
+TELECOMMUNICATION  
+STANDARDIZATION SECTOR  
+OF ITU
+
+# T.180
+
+(06/98)
+
+SERIES T: TERMINALS FOR TELEMATIC SERVICES
+
+---
+
+# **Homogeneous access mechanism to communication services**
+
+ITU-T Recommendation T.180
+
+(Previously CCITT Recommendation)
+
+---
+
+## ITU-T T-SERIES RECOMMENDATIONS **TERMINALS FOR TELEMATIC SERVICES**
+
+![A large empty rectangular box with a double border.](c803f6f6e2c49429d2951832bd0f208d_img.jpg)
+
+A large empty rectangular box with a double border, likely intended for a diagram or additional text related to the terminal services.
+
+A large empty rectangular box with a double border.
+
+*For further details, please refer to ITU-T List of Recommendations.*
+
+# **HOMOGENEOUS ACCESS MECHANISM TO COMMUNICATION SERVICES**
+
+## **Summary**
+
+This Recommendation specifies a homogenous access mechanism to communication services (called XAPI). The XAPI, which is an abbreviation for eXtensive Application Programming Interface, is an operating system and language-independent programming interface to general communication services.
+
+This Recommendation specifies a set of functions which allow XAPI users to have access to the services of an underlying provider. These functions apply to all providers which are specified in this Recommendation. A model of communication is introduced which defines the semantics of those XAPI functions which are communication related.
+
+Making available appropriate providers, the communication system can be tailored to specific requirements, and all communication services are accessible via one homogenous access mechanism.
+
+## **Source**
+
+ITU-T Recommendation T.180 was prepared by ITU-T Study Group 8 (1997-2000) and was approved under the WTSC Resolution No. 1 procedure on the 18<sup>th</sup> of June 1998.
+
+# FOREWORD
+
+ITU (International Telecommunication Union) is the United Nations Specialized Agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the ITU. The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis.
+
+The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics.
+
+The approval of Recommendations by the Members of the ITU-T is covered by the procedure laid down in WTSC Resolution No. 1.
+
+In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC.
+
+## NOTE
+
+In this Recommendation the term *recognized operating agency (ROA)* includes any individual, company, corporation or governmental organization that operates a public correspondence service. The terms *Administration*, *ROA* and *public correspondence* are defined in the *Constitution of the ITU (Geneva, 1992)*.
+
+# INTELLECTUAL PROPERTY RIGHTS
+
+The ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. The ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process.
+
+As of the date of approval of this Recommendation, the ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementors are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database.
+
+© ITU 1999
+
+All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU.
+
+# CONTENTS
+
+|                                                                         | <b>Page</b> |
+|-------------------------------------------------------------------------|-------------|
+| 1 Scope.....                                                            | 1           |
+| 2 References.....                                                       | 1           |
+| 3 Definitions .....                                                     | 2           |
+| 4 Abbreviations.....                                                    | 3           |
+| 5 Structure of this Recommendation .....                                | 4           |
+| 6 Introduction to the XAPI.....                                         | 5           |
+| 6.1 Location of the XAPI.....                                           | 5           |
+| 6.2 Phases of communication .....                                       | 7           |
+| 6.3 Applications that are supported by XAPI .....                       | 9           |
+| 7 A Model of communication.....                                         | 12          |
+| 7.1 Classes of communication .....                                      | 12          |
+| 7.1.1 Peer-to-peer communication.....                                   | 12          |
+| 7.1.2 Multipeer communication.....                                      | 14          |
+| 7.2 The state transition diagram as part of the model .....             | 18          |
+| 8 Description of the XAPI .....                                         | 22          |
+| 8.1 XAPI in point-to-point and in multipoint environments .....         | 22          |
+| 8.2 XAPI functions and the corresponding state transition diagram ..... | 25          |
+| 9 XAPI functions .....                                                  | 31          |
+| 9.1 Conventions .....                                                   | 34          |
+| 9.2 Communication-related functions.....                                | 35          |
+| 9.2.1 X-CONCONF/x_conconf.....                                          | 35          |
+| 9.2.2 X-CONIND/x_conind.....                                            | 36          |
+| 9.2.3 X-CONREQ/x_conreq.....                                            | 36          |
+| 9.2.4 X-CONRSP/x_conrsp.....                                            | 37          |
+| 9.2.5 X-RCVDATA/x_rcvdata.....                                          | 38          |
+| 9.2.6 X-RCVDIS/x_rcvdis .....                                           | 39          |
+| 9.2.7 X-RCVINFO/x_rcvinfo.....                                          | 40          |
+| 9.2.8 X-RCVSP/x_rcvsp .....                                             | 40          |
+| 9.2.9 X-RELCONF/x_relconf .....                                         | 41          |
+| 9.2.10 X-RELIND/x_relind .....                                          | 41          |
+| 9.2.11 X-RELREQ/x_relreq .....                                          | 42          |
+| 9.2.12 X-RELRSP/x_relrsp .....                                          | 42          |
+| 9.2.13 X-SNDDATA/x_snddata.....                                         | 42          |
+| 9.2.14 X-SNDDIS/x_snddis .....                                          | 43          |
+
+|                                                                             | <b>Page</b> |
+|-----------------------------------------------------------------------------|-------------|
+| 9.2.15 X-SNDINFO/x_sndinfo.....                                             | 44          |
+| 9.2.16 X-SNDSP/x_sndsp .....                                                | 44          |
+| 9.3 Not communication-related functions.....                                | 45          |
+| 9.3.1 Functions for the initialization and de-initialization phase .....    | 45          |
+| 9.3.2 Utility functions .....                                               | 47          |
+| Annex A – Interface definition language description .....                   | 52          |
+| Annex B – Error codes .....                                                 | 65          |
+| Appendix I – Examples of XAPI access to service providers.....              | 69          |
+| I.1 XAPI access to the service provider for the ISDN B-channel .....        | 70          |
+| I.1.1 Scope .....                                                           | 70          |
+| I.1.2 References.....                                                       | 70          |
+| I.1.3 Definitions .....                                                     | 71          |
+| I.1.4 Abbreviations.....                                                    | 71          |
+| I.1.5 Conventions .....                                                     | 71          |
+| I.1.6 Introduction to the ISDN physical service provider access .....       | 72          |
+| I.1.7 Description of the access to the ISDN physical service provider ..... | 72          |
+| I.2 XAPI access to the service provider for BFT over T.30.....              | 78          |
+| I.2.1 Scope .....                                                           | 78          |
+| I.2.2 References.....                                                       | 79          |
+| I.2.3 Definitions .....                                                     | 79          |
+| I.2.4 Abbreviations.....                                                    | 79          |
+| I.2.5 Conventions .....                                                     | 80          |
+| I.2.6 Introduction to the BFT(T.30) provider access .....                   | 81          |
+| I.2.7 Description of the access to the BFT(T.30) provider .....             | 81          |
+| I.3 XAPI access to the service provider for FAX4 and BFT.....               | 92          |
+| I.3.1 Scope .....                                                           | 92          |
+| I.3.2 References.....                                                       | 93          |
+| I.3.3 Definitions .....                                                     | 94          |
+| I.3.4 Abbreviations.....                                                    | 94          |
+| I.3.5 Conventions .....                                                     | 94          |
+| I.3.6 Introduction to the FAX4/BFT service provider access .....            | 95          |
+| I.3.7 Description of the access to the FAX4/BFT service provider .....      | 95          |
+| I.4 XAPI access to the service provider for ACSE and ROSE .....             | 125         |
+| I.4.1 Scope .....                                                           | 125         |
+| I.4.2 References.....                                                       | 126         |
+| I.4.3 Definitions .....                                                     | 127         |
+| I.4.4 Abbreviations.....                                                    | 127         |
+
+|                                                                               | <b>Page</b> |
+|-------------------------------------------------------------------------------|-------------|
+| I.4.5 Conventions .....                                                       | 127         |
+| I.4.6 Introduction to the ACSE/ROSE provider access .....                     | 128         |
+| I.4.7 Description of the access to the ACSE/ROSE provider .....               | 131         |
+| I.5 XAPI access to a Service Provider for Audio and Video (AV) Control.....   | 163         |
+| I.5.1 Scope .....                                                             | 163         |
+| I.5.2 References.....                                                         | 163         |
+| I.5.3 Definitions .....                                                       | 164         |
+| I.5.4 Abbreviations.....                                                      | 164         |
+| I.5.5 Conventions .....                                                       | 165         |
+| I.5.6 Introduction to the video codec service provider access .....           | 166         |
+| I.5.7 Description of the access to the Video Codec Service Provider.....      | 167         |
+| I.6 XAPI access to the service provider for the T.120 conference control..... | 242         |
+| I.6.1 Scope .....                                                             | 242         |
+| I.6.2 References.....                                                         | 244         |
+| I.6.3 Definitions .....                                                       | 244         |
+| I.6.4 Abbreviations.....                                                      | 244         |
+| I.6.5 Conventions .....                                                       | 244         |
+| I.6.6 Introduction to the conference control provider access .....            | 245         |
+| I.6.7 Description of the access to the conference control provider .....      | 247         |
+| I.7 XAPI access to the service provider for T.127 MBFT .....                  | 273         |
+| I.7.1 Scope .....                                                             | 273         |
+| I.7.2 References.....                                                         | 275         |
+| I.7.3 Definitions .....                                                       | 275         |
+| I.7.4 Abbreviations.....                                                      | 275         |
+| I.7.5 Conventions .....                                                       | 276         |
+| I.7.6 Introduction to the MBFT service provider access.....                   | 277         |
+| I.7.7 Description of the access to the MBFT service provider.....             | 277         |
+| Appendix II – Tutorial: XAPI and selected providers .....                     | 310         |
+| II.1 XAPI and the ACSE/ROSE provider .....                                    | 310         |
+| II.2 XAPI and the specific T.120 conference provider.....                     | 315         |
+| II.2.1 The T.120 system model.....                                            | 315         |
+| II.2.2 T.120 MBFT conferencing .....                                          | 317         |
+
+
+
+# Recommendation T.180
+
+# HOMOGENEOUS ACCESS MECHANISM TO COMMUNICATION SERVICES
+
+(Geneva, 1998)
+
+# 1 Scope
+
+The XAPI, which is an abbreviation for eXtensive Application Programming Interface, is an operating system and language-independent homogenous access mechanism to general communication services. It is not dedicated to a certain layer, but allows access to all layers of the OSI reference model and other layered communication models (e.g. conferencing). The XAPI provides a framework of functions for the use in communication applications. All communication services are accessible through this set of functions. The XAPI does not impose any restrictions on the service interface of the underlying communication platform.
+
+Which services are made available via the XAPI depends on the installed service providers, and not on the XAPI, which only provides the access mechanism. New service providers can be added in the XAPI configuration. Thus, the communication system can be tailored to specific requirements and all communication services are accessible via one homogeneous access mechanism.
+
+# 2 References
+
+The following ITU-T Recommendations and other references contain provision which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; all users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published.
+
+- ITU-T Recommendation F.581 (1993), *Guidelines for Programming Communication Interfaces (PCIs) definition: Service Recommendation.*
+- ITU-T Recommendation H.320 (1997), *Narrow-band visual telephone systems and terminal equipment.*
+- ITU-T Recommendation T.30 (1996), *Procedures for document facsimile transmission in the general switched telephone network.*
+- ITU-T Recommendation T.120 (1996), *Data protocols for multimedia conferencing.*
+- ITU-T Recommendation T.121 (1996), *Generic application template.*
+- ITU-T Recommendation T.122 (1998), *Multipoint communication service – Service definition.*
+- ITU-T Recommendation T.123 (1996), *Network specific data protocol stacks for multimedia conferencing.*
+- ITU-T Recommendation T.124 (1998), *Generic Conference Control.*
+- ITU-T Recommendation T.125 (1994), *Multipoint communication service protocol specification.*
+- ITU-T Recommendation T.127 (1995), *Multipoint binary file transfer protocol.*
+
+- ITU-T Recommendation T.434 (1996), *Binary file transfer format for the telematic services*.
+- ITU-T Recommendation X.200 (1994) | ISO/IEC 7498-1:1994, *Information technology – Open Systems Interconnection – Basic Reference Model: The Basic Model*.
+
+# 3 Definitions
+
+**3.1** For the purposes of this Recommendation, the following terms as defined in Recommendation X.200 apply:
+
+- **(N)-connection;**
+- **(N)-entity;**
+- **(N)-layer;**
+- **(N)-service;**
+- **(N)-Service Access Point (SAP).**
+
+**3.2** For the purposes of this Recommendation, the following terms as defined in Recommendation T.124 apply:
+
+- **conference;**
+- **Multipoint Control Unit;**
+- **node;**
+- **terminal.**
+
+**3.3** This Recommendation defines the following terms:
+
+**3.3.1 application connection:** Serves for communication between application entities.
+
+**3.3.2 application entity:** A service user, or some other entity, which may participate in a connection.
+
+**3.3.3 application system:** A protocol stack comprising some or all of the OSI layers 5 (Session) to 7 (Application).
+
+**3.3.4 communication endpoint:** Synonymously used for "Service Endpoint".
+
+**3.3.5 communication platform:** Consists in a number of communication service providers, in a homogeneous access mechanism, by means of which service users, which are distributed in space, may establish communication between them.
+
+**3.3.6 conference control:** Encompasses functions such as conference establishment and termination, information about each node which is participating in the same conference, information about each application entity in the conference, coordination of conference conductorship, as well as other miscellaneous functions.
+
+**3.3.7 connection:** A logical association between two or more entities, enabling communication between them.
+
+**3.3.8 control entity:** A specific service user which handles conference control and which may participate in a connection.
+
+**3.3.9 control connection:** Serves for communication between control entities.
+
+**3.3.10 multipeer relationship:** In a multipeer relationship, the users may negotiate the characteristics of their interaction and, afterwards, communicate with each other obeying the rules they have negotiated: all users (an entity and its peers) have potential equal rights.
+
+**3.3.11 multipoint aware application:** An application entity which is able to participate in a multipoint connection.
+
+**3.3.12 multipoint connection:** A connection between more than two entities.
+
+**3.3.13 Peer-to-peer relationship:** In a peer-to-peer relationship, the users may negotiate the characteristics of their interaction and, afterwards, communicate obeying the rules they have negotiated: both users (an entity and its peer entity) have potential equal rights.
+
+**3.3.14 point-to-point connection:** A connection between two entities.
+
+**3.3.15 protocol module:** The implementation of a communication protocol whose services can be accessed via the XAPI. Usually a protocol module implements a single layer in the OSI sense.
+
+**3.3.16 service access point:** The point at which services are provided to a user. Associated with each SAP is an address.
+
+**3.3.17 service endpoint:** Specifies the local link between a service user and a service provider. It consists of two parts: a SAP address and an additional identifier (optional), which is unique within the scope of the SAP.
+
+**3.3.18 service provider:** A communication protocol stack that provides a certain service to the user at the upper interface of its topmost protocol module.
+
+**3.3.19 session:** A peer-to-peer or multipeer relationship between application entities which are communicating via an application connection. In general, a session brings into focus a specific topic of discussion.
+
+**3.3.20 transport system:** A protocol stack comprising some or all of the OSI layers 1 (Physic) to 4 (Transport).
+
+# 4 Abbreviations
+
+This Recommendation uses the following abbreviations:
+
+|      |                                     |
+|------|-------------------------------------|
+| AAL  | ATM Adaptation Layer                |
+| ACSE | Association Control Service Element |
+| ATM  | Asynchronous Transfer Mode          |
+| AVC  | Audiovisual Control                 |
+| BFT  | Binary File Transfer                |
+| CLS  | Connectionless Service              |
+| COS  | Connection oriented Service         |
+| CSCW | Computer-Supported Cooperative Work |
+| Fd   | File Descriptor                     |
+| GCC  | Generic Conference Control          |
+| HDLC | High-Level Data-Link Control        |
+| IDL  | Interface Definition Language       |
+| ISDN | Integrated Services Digital Network |
+| MBFT | Multipoint Binary File Transfer     |
+| MCS  | Multipoint Communication Service    |
+
+|      |                                             |
+|------|---------------------------------------------|
+| MCU  | Multipoint Control Unit                     |
+| MRPC | Multipoint Remote Procedure Call            |
+| NSAP | Network Service Access Point                |
+| NSM  | Network-Specific Mappings                   |
+| OSI  | Open Systems Interconnection                |
+| PDId | Parallel Data Identifier                    |
+| PDU  | Protocol Data Unit                          |
+| PSAP | Presentation Service Access Point           |
+| PSTN | Public Switched Telephone Network           |
+| QoS  | Quality of Service                          |
+| RDC  | Remote Device Control                       |
+| ROSE | Remote Operations Service Element           |
+| RTSE | Reliable Transfer Service Element           |
+| SAP  | Service Access Point                        |
+| SP   | Service Primitive                           |
+| SSAP | Session Service Access Point                |
+| TCP  | Transmission Control Protocol               |
+| TSAP | Transport Service Access Point              |
+| XAPI | eXtensive Application Programming Interface |
+
+# 5      **Structure of this Recommendation**
+
+The description of the XAPI is divided into three steps, each step representing a specific level of abstraction. The main part of this Recommendation contains steps 1 and 2 which are common for all providers. Step 3 is defined in Appendix I containing a list of examples of service providers. Appendix I contains seven parts (I.1 to I.7).
+
+### **Step 1:**
+
+Subclauses 6 and 7 introduce the XAPI and a model of communication which is supported by the XAPI. The model represents appropriate connection-oriented communication service primitives which apply not only to peer-to-peer but also to multipeer communication. The service primitives and their sequences possible at a service access point describe a generic communication structure which is applicable to data services as well as to multimedia services.
+
+### **Step 2:**
+
+Subclauses 8 and 9 introduce the XAPI functions in detail. The relationship of the functions with respect to the model of communication (step 1) is pointed out.
+
+### Step 3:
+
+Steps 1 and 2 specify those aspects of the XAPI which apply to all providers and which are used by all types of applications. Steps 1 and 2 do not contain any protocol-specific information as option or service primitive definitions. All definitions that may be carried by XAPI services, but related to the specific underlying protocol stacks, are contained as examples in the following subclauses of Appendix I:
+
+- Subclause I.1: XAPI access to the service provider for the ISDN B-channel
+- Subclause I.2: XAPI access to the service provider for BFT over T.30
+- Subclause I.3: XAPI access to the service provider for FAX4 and BFT
+- Subclause I.4: XAPI access to the service provider for ACSE and ROSE
+- Subclause I.5: XAPI access to the service provider for audio and video control
+- Subclause I.6: XAPI access to the service provider for T.120 conference control
+- Subclause I.7: XAPI access to the service provider for T.127 MBFT
+
+An IDL description of the XAPI can be found in Annex A.
+
+A list of error codes that may be returned by the XAPI functions is given in Annex B.
+
+Appendix I describes the access of the XAPI user to specific providers.
+
+A tutorial is presented in Appendix II.
+
+# 6 Introduction to the XAPI
+
+The XAPI, which is an abbreviation for eXtensive Application Programming Interface, is an operating system and language-independent homogenous access mechanism to general communication services. It is not dedicated to a certain layer, but allows access to all layers of the OSI reference model and other layered communication models (e.g. conferencing). The XAPI provides a framework of functions for the use in communication applications. All communication services are accessible through this set of functions. The XAPI imposes no restrictions on the service interface of the underlying communication platform.
+
+The services made available via XAPI depend on the installed service providers, and not on XAPI which only provides the access mechanism. New service providers can be added in the XAPI configuration. Thus the communication system can be tailored to specific requirements, and all communication features are accessible via one homogeneous interface.
+
+This Recommendation specifies the general aspects of the XAPI, as they apply to all providers and as they are used by all types of applications. It does not contain any protocol-specific information as option or service primitive definitions. All definitions that are carried by XAPI services, but related to the specific underlying protocols, are contained as examples in Appendix I: e.g. XAPI access to the service provider for BFT over T.30, XAPI access to the service provider for ACSE and ROSE, XAPI access to the service provider for audio and video control, XAPI access to the service provider for T.120 MBFT, etc.
+
+## 6.1 Location of the XAPI
+
+The XAPI is a communication interface inside a terminal equipment. It allows a service user to communicate with its respective service provider. Therefore, two entities can be distinguished around the XAPI. These are the service user (XAPI user, or user for short) and the service provider (or provider for short).
+
+The XAPI defines a number of functions. First, the XAPI allows for the binding between a user and a provider (Initialization phase). After having performed successfully this process, a connection between the user and its peer(s) may be established, maintained and released (Communication establishment phase, Data transfer phase, Communication release phase). Finally, the interaction between user and provider is terminated (De-initialization phase).
+
+There are several XAPI utility functions which can be used in all phases of communication. These functions are used to inform the XAPI user about current events on a service endpoint or indicate that no event is available, to change the execution mode (i.e. synchronous or asynchronous mode) of the XAPI functions for the service endpoint, to inform the user about the current characteristics of the underlying service providers, to negotiate protocol options, to provide error handling, etc.
+
+A service endpoint specifies a local link between a specific XAPI user and a specific provider. During the initialization phase a service endpoint is created and activated for use in communication. Figure 1 gives a picture of how the XAPI relates to user and provider after the creation of a communication path between them. Fd is the name of the accessory service endpoint.
+
+![Diagram showing the local link between a service user (XAPI user) and a service provider, connected via the XAPI interface.](a33da0f14e456f92539ce3e9b7d81f9a_img.jpg)
+
+```
+
+graph TD
+    User["service user  
+(XAPI user)"] --- XAPI
+    XAPI --- Provider["service provider"]
+    style XAPI fill:none,stroke:none
+  
+```
+
+The diagram illustrates the connection between a service user and a service provider through the XAPI. A box at the top is labeled "service user (XAPI user)". A box at the bottom is labeled "service provider". A thick horizontal line represents the XAPI interface. A vertical line connects the service user box to the XAPI line, and another vertical line connects the XAPI line to the service provider box. The label "XAPI" is placed to the right of the horizontal line. Below the diagram, the identifier "T0827060-97" is written.
+
+Diagram showing the local link between a service user (XAPI user) and a service provider, connected via the XAPI interface.
+
+**Figure 1/T.180 – Local link between user and provider,  
+identified by the service endpoint Fd**
+
+The XAPI supports connection-mode operations defined in the framework of OSI (e.g. ACSE/ROSE) and non-OSI (e.g. Video Codec Controller) as well as communication functions for multipoint environments (e.g. conferencing).
+
+The location of the XAPI depends on the choice of the underlying provider. Figure 2 shows the general location of the XAPI within an OSI-like structured platform: the XAPI is located within the application layer (layer 7) of the OSI Reference Model.
+
+NOTE – The location also reflects the fact that the XAPI may be realized as a driver interface which is designed for use in different system architectures. Therefore, task-oriented functions such as file handling shall not be performed below the XAPI.
+
+![Diagram showing the location of XAPI within an OSI-like structured platform. The diagram is divided into two main sections: 'XAPI user' at the top and 'provider' at the bottom, separated by a thick horizontal line labeled 'XAPI'. The 'XAPI user' section contains a box labeled 'Layer 7'. The 'provider' section contains a stack of boxes labeled 'Layer 6', 'Layer 5', 'Layer 4', 'Layer 3', 'Layer 2', and 'Layer 1' from top to bottom. A bracket on the right side of the provider section is labeled 'provider'. A small text 'T0827070-97' is located at the bottom center of the diagram.](33ed1f9b27c7c21c797aa928b0f06851_img.jpg)
+
+Diagram showing the location of XAPI within an OSI-like structured platform. The diagram is divided into two main sections: 'XAPI user' at the top and 'provider' at the bottom, separated by a thick horizontal line labeled 'XAPI'. The 'XAPI user' section contains a box labeled 'Layer 7'. The 'provider' section contains a stack of boxes labeled 'Layer 6', 'Layer 5', 'Layer 4', 'Layer 3', 'Layer 2', and 'Layer 1' from top to bottom. A bracket on the right side of the provider section is labeled 'provider'. A small text 'T0827070-97' is located at the bottom center of the diagram.
+
+**Figure 2/T.180 – Location of the XAPI within an OSI-like structured platform**
+
+## 6.2 Phases of communication
+
+The XAPI supports connection-oriented communication between users. The four communication phases provided by XAPI functions are:
+
+- Initialization/de-initialization,
+- Connection establishment,
+- Data transfer,
+- Connection release.
+
+Communication-related additional functions which are not mapped to a specific communication phase are listed in this subclause too.
+
+In the following, these phases as well as the additional functions are briefly described. A detailed definition of the functions is contained in clauses 8 and 9 respectively. Clause 7 introduces the semantic model for the communication-relevant functions of the XAPI.
+
+#### – Initialization/de-Initialization phase
+
+During the initialization phase, a service endpoint for the required service provider is created and activated for use in communication. In the following, this service endpoint is called Fd or Fd-i. When communication has finished, the endpoint is first deactivated and finally destructed in the de-initialization phase. There are four XAPI functions, supporting initialization and de-initialization. They are listed in the sequential order, in which they are used:
+
+Open:       x\_open  
+ Bind:       x\_bind  
+ Unbind:     x\_unbind  
+ Close:      x\_close
+
+#### – **Connection establishment phase**
+
+During the connection establishment phase, users of the same service establish a connection between them (e.g. a Telefax terminal is connected to the remote Telefax terminal), or each of them establishes access to some appropriate multipoint connection by means of which they may communicate in a multipoint fashion with each other (e.g. a multipoint aware user application is connected to a multipoint session which offers communication facilities to matching user applications).
+
+These functions are supported by the XAPI in the connection establishment phase:
+
+|                     |           |
+|---------------------|-----------|
+| Connect request:    | x_conreq  |
+| Connect confirm:    | x_conconf |
+| Connect indication: | x_conind  |
+| Connect response:   | x_conrsp  |
+
+#### – **Data transfer phase**
+
+Once communication has been established, data may be transferred. There are functions to initiate the transfer of data, and additional functions (i.e. x\_sndsp and x\_rcvsp) that may be invoked during the data transfer phase. The latter serve for different purposes; e.g. the functions are used to change the set of capabilities which characterize the data transfer phase. These functions are supported by the XAPI in the data transfer phase:
+
+|                            |           |
+|----------------------------|-----------|
+| Send data:                 | x_snddata |
+| Receive data:              | x_rcvdata |
+| Send service primitive:    | x_sndsp   |
+| Receive service primitive: | x_rcvsp   |
+
+#### – **Connection release phase**
+
+The XAPI provides two ways to leave the communication: abortive release (disconnection) and orderly release. The abortive release is a mandatory feature and is to be supported by all service providers. The orderly release is an optional feature. These functions are supported by the XAPI in the connection release phase:
+
+|                       |           |
+|-----------------------|-----------|
+| Send disconnect:      | x_snddis  |
+| Receive disconnect:   | x_rcvdis  |
+| Release request:      | x_relreq  |
+| Release confirmation: | x_relconf |
+| Release indication:   | x_relind  |
+| Release response:     | x_relrsp  |
+
+#### – **Additional communication-related functions**
+
+During connection establishment, data transfer, and connection release, general information services (e.g. information on conferences that are currently in existence) may be invoked by the user. In general, these services are not related to some specific connection. These functions are supported by the XAPI:
+
+|                      |           |
+|----------------------|-----------|
+| Send information:    | x_sndinfo |
+| Receive information: | x_rcvinfo |
+
+The function `x_rcvend` indicates to the user that the local resource management has finished all operations concerning the release phase of a connection and that a new connection may now be established:
+
+Receive end: `x_rcvend`
+
+## 6.3 Applications that are supported by XAPI
+
+Various kinds of applications are supported by XAPI. Figure 3 shows examples of XAPI users and sketches underlying providers.
+
+![Figure 3/T.180: Example: Applications, protocols and networks around the XAPI. The diagram illustrates a layered architecture. At the top, four ovals represent 'Applications': 'XAPI MBFT user', 'XAPI H.320 user', 'XAPI FAX 3/4 user', and 'XAPI Mail user'. These are connected to a central rectangular box labeled 'XAPI', which is part of a 'Homogeneous access structure'. Below this, three vertical rectangles of decreasing height represent 'Different types of protocols and transparent access'. At the bottom, three boxes represent 'Networks': 'ISDN', 'ATM', and 'PSTN'. The entire diagram is labeled with 'T0827080-97' at the bottom right.](df82d77a0d2637cbf2da9ea920a554fa_img.jpg)
+
+Figure 3/T.180 illustrates the architecture around the XAPI interface. It shows four types of applications (XAPI MBFT user, XAPI H.320 user, XAPI FAX 3/4 user, and XAPI Mail user) connected to a central XAPI block, which represents a homogeneous access structure. This structure is then connected to three different types of protocols and transparent access (ISDN, ATM, and PSTN), which are the underlying networks. The diagram is labeled T0827080-97.
+
+Figure 3/T.180: Example: Applications, protocols and networks around the XAPI. The diagram illustrates a layered architecture. At the top, four ovals represent 'Applications': 'XAPI MBFT user', 'XAPI H.320 user', 'XAPI FAX 3/4 user', and 'XAPI Mail user'. These are connected to a central rectangular box labeled 'XAPI', which is part of a 'Homogeneous access structure'. Below this, three vertical rectangles of decreasing height represent 'Different types of protocols and transparent access'. At the bottom, three boxes represent 'Networks': 'ISDN', 'ATM', and 'PSTN'. The entire diagram is labeled with 'T0827080-97' at the bottom right.
+
+**Figure 3/T.180 – Example: Applications, protocols and networks around the XAPI**
+
+Different types of applications are recognized that make use of XAPI. This implies that the use of XAPI functions may have different interpretations in different application environments.
+
+There are point-to-point applications, where two users are directly connected during the communication phase and "multipoint-aware" applications, where many users may communicate with each other. Typical examples for point-to-point applications are Binary File Transfer (according to Recommendation T.434) or Telefax applications. As XAPI is the communication interface, store-and-forward applications also fall into this type of point-to-point communication.
+
+There are also applications where the user may be connected to a service (e.g. offered by the network operator). The service itself may connect other providers on behalf of the requesting user and provide the requested information. In this case, no direct connection exists between end-users for a specific time period during the communication phase. (This may be the case when an application download is necessary from a level-1 gateway, before the user can be connected to the service provider.)
+
+Additionally, the XAPI may be used in cases where nesting of applications is supported: a first "general" application is established and "specific" applications may be invoked afterwards (see Figure 15). Conferences are an example of such a configuration, in which several users can agree to establish a conference as the general application and subsequently select specific multipoint-aware applications that are used in the conference (e.g. Multipoint Binary File Transfer, Still Image, etc.).
+
+The different types of applications may have an impact on the use of the XAPI functions in the four communication phases. For example, for the point-to-point applications, only one initialization phase is necessary (i.e. only one connection is needed). In turn, for conference configurations, more than one connection may be needed. Details are described in clause 7.
+
+The XAPI divides XAPI user processes from service providers. So the XAPI is that part of the functionality of a platform by means of which an arbitrary user may have access to appropriate services to meet the user requirements.
+
+Many types of applications may have access to different service providers. Figure 4 illustrates the access to the communication platform.
+
+![](9c6461e1e94afae4dec455e69a2ce152_img.jpg)
+
+|                                      |                 |                       |                                    |                      |                     |               |
+|--------------------------------------|-----------------|-----------------------|------------------------------------|----------------------|---------------------|---------------|
+| Telephony<br>G.711<br>G.722<br>G.728 | Video-telephony | Video-on-demand       | Still image transfer               | Document handling    | Electronic commerce | Joint editing |
+| Multipoint Binary File transfer      | Conferencing    | Moving image transfer | Pointer service and joined viewing | Binary file transfer | Home shopping       | CSCW          |
+
+![A diagram showing the access to a communication platform across seven layers. Layer 7 is a shaded bar labeled 'XAPI'. Below it, Layer 6 contains various protocols like BFT, ROSE, FAX4, MBFT, MRPC, and Node controller. Layer 5 contains GCC and MCS. Layer 4 contains X.225 and X.224. Layer 3 contains TCP. Layer 2 contains T.30 and Header accdg. to T.70. Layer 1 contains various ISDN and PSTN protocols like H.221, H.230, H.242, I.361, I.430/I.431, I.432, and X.21/X.2 bis. Arrows indicate bidirectional communication between the XAPI layer and the protocols in the lower layers.](7f25db95ce3916c0e09803b861a2f7bc_img.jpg)
+
+The diagram illustrates the access to a communication platform across seven layers:
+
+- Layer 7:** A shaded bar labeled "XAPI".
+- Layer 6:** Contains protocols: BFT (T.434), ROSE, FAX4 (T.563, T.503), MBFT (T.127), MRPC, and Node controller (Conf.).
+- Layer 5:** Contains protocols: GCC and MCS.
+- Layer 4:** Contains protocols: X.225 and X.224.
+- Layer 3:** Contains protocol: TCP.
+- Layer 2:** Contains protocols: T.30 and Header accdg. to T.70.
+- Layer 1:** Contains protocols: T.30, Header accdg. to T.70, H.221, H.230, H.242, I.361, I.430/I.431, I.432, and X.21/X.2 bis.
+
+Arrows indicate bidirectional communication between the XAPI layer and the protocols in the lower layers.
+
+A diagram showing the access to a communication platform across seven layers. Layer 7 is a shaded bar labeled 'XAPI'. Below it, Layer 6 contains various protocols like BFT, ROSE, FAX4, MBFT, MRPC, and Node controller. Layer 5 contains GCC and MCS. Layer 4 contains X.225 and X.224. Layer 3 contains TCP. Layer 2 contains T.30 and Header accdg. to T.70. Layer 1 contains various ISDN and PSTN protocols like H.221, H.230, H.242, I.361, I.430/I.431, I.432, and X.21/X.2 bis. Arrows indicate bidirectional communication between the XAPI layer and the protocols in the lower layers.
+
+Figure 4/T.180 – Example: Access to the communication platform
+
+Using this platform, single medium as well as multimedia applications and/or point-to-point as well as multipoint applications are supported by appropriate providers.
+
+Figure 4 *bis* shows the relationship between the XAPI, the T.611 and the T.200 interfaces.
+
+![Diagram illustrating the relationship between XAPI, T.611, and T.200 interfaces. The diagram is organized into three main layers. The top layer, labeled 'Applications', contains four ovals: 'Workflow', 'Conferencing', 'Video-on-Demand', and 'Other MM core services'. The middle layer, labeled 'Generic teleservices', contains four ovals: 'MM-Mail', 'MM-Collaboration', 'Telematic Services', and 'MM-Archive'. The bottom layer contains a large oval labeled 'Generic Communication System' and seven smaller ovals: 'Mobile', 'CATV', 'Internet', 'PSTN', 'X.25 Frame Relay', 'ATM', and 'ISDN'. A thick horizontal line separates the 'Generic teleservices' layer from the 'Generic Communication System' layer, with the text 'XAPI – Homogeneous Access Mechanism to Communication Services' to its right. Two horizontal lines labeled 'T.611' are positioned between the 'Applications' and 'Generic teleservices' layers, with lines connecting 'Workflow' to 'MM-Mail', 'Conferencing' to 'MM-Collaboration', and 'Video-on-Demand' to 'Telematic Services'. A horizontal line labeled 'T.200' is positioned between the 'Generic Communication System' and the bottom layer, with lines connecting the 'Generic Communication System' to 'Mobile', 'CATV', 'Internet', 'PSTN', 'X.25 Frame Relay', 'ATM', and 'ISDN'. The reference 'T0828070-98' is located at the bottom right of the diagram.](5445597cceefaca1ac89e710fe339325_img.jpg)
+
+Diagram illustrating the relationship between XAPI, T.611, and T.200 interfaces. The diagram is organized into three main layers. The top layer, labeled 'Applications', contains four ovals: 'Workflow', 'Conferencing', 'Video-on-Demand', and 'Other MM core services'. The middle layer, labeled 'Generic teleservices', contains four ovals: 'MM-Mail', 'MM-Collaboration', 'Telematic Services', and 'MM-Archive'. The bottom layer contains a large oval labeled 'Generic Communication System' and seven smaller ovals: 'Mobile', 'CATV', 'Internet', 'PSTN', 'X.25 Frame Relay', 'ATM', and 'ISDN'. A thick horizontal line separates the 'Generic teleservices' layer from the 'Generic Communication System' layer, with the text 'XAPI – Homogeneous Access Mechanism to Communication Services' to its right. Two horizontal lines labeled 'T.611' are positioned between the 'Applications' and 'Generic teleservices' layers, with lines connecting 'Workflow' to 'MM-Mail', 'Conferencing' to 'MM-Collaboration', and 'Video-on-Demand' to 'Telematic Services'. A horizontal line labeled 'T.200' is positioned between the 'Generic Communication System' and the bottom layer, with lines connecting the 'Generic Communication System' to 'Mobile', 'CATV', 'Internet', 'PSTN', 'X.25 Frame Relay', 'ATM', and 'ISDN'. The reference 'T0828070-98' is located at the bottom right of the diagram.
+
+**Figure 4 *bis*/T.180 – Relationship between XAPI, T.611, and T.200 interfaces**
+
+# 7 A Model of communication
+
+This clause describes a model of communication which is supported by the XAPI. The model represents appropriate connection-oriented communication service primitives, which apply not only to peer-to-peer but also to multipoint communication. The service primitives and their sequences possible at service access points describe a generic communication structure, which is applicable to data services as well as to multimedia services.
+
+## 7.1 Classes of communication
+
+### 7.1.1 Peer-to-peer communication
+
+The OSI reference model describes cooperation between computers independent of implementation aspects.
+
+The *layer* is one of the basic concepts of the OSI reference model. When referring to a single layer, it is conventional to call it the (N)-layer. In the same way, the layer above is the (N + 1)-layer and the layer beneath the (N – 1)-layer.
+
+The (N)-layer protocol provides the functionality of the (N)-layer: every layer is defined by a precise set of functions and associated messages [Protocol Data Units (PDUs)]. A "local part" of an (N)-layer protocol is called (N)-entity.
+
+The purpose of a protocol is to provide a service to users (entities) residing above the respective layer boundary.
+
+(N)-service users have access to the (N)-service only at (N)-Service Access Points [(N)-SAPs]. Associated with each SAP is an address. The address of that SAP can be used to identify the entity. A service endpoint consists of a SAP address and an additional identifier, which is unique within the scope of the SAP.
+
+Most OSI relationships among communicating users (applications) are peer-to-peer. In a peer-to-peer relationship, the users may negotiate the characteristics of their interaction: both users (an entity and its peer entity) have potential equal rights.
+
+In the framework of the OSI reference model, two modes of operations are defined: connection oriented (CO) operation and connectionless (CL) operation.
+
+For connection mode operation, an (N)-connection is defined as "an association established by the (N)-layer between two or more (N + 1)-entities for the transfer of data". Three phases of operation are characterizing this mode, namely connection establishment, data transfer, and connection release.
+
+The definition of the OSI services for connections between two entities (point-to-point connections) reflects these modes: for CO operation dedicated services such as (N)-CONNECT for connection establishment, (N)-DATA in the data transfer phase, and (N)-DISCONNECT or (N)-RELEASE for connection release are specified. The elements of these services are called service primitives. They apply at specific service endpoints.
+
+These primitives and their sequences specify services which may be accessed at (almost) any layer boundary: the layer specific information is contained in accessory parameters. Thus the primitives and their sequences give rise to call the model also a generic communication structure.
+
+There are OSI services in the data transfer phase, which apply only to a few layers. The OSI Session Service S-TOKEN-PLEASE is an example. In the model of communication described in this subclause these (and other) services are subsumed under the primitives X-SNDSP and X-RCVSP (see below).
+
+Figure 5 shows the (N)-CONNECT service. User A is the initiator of an (N)-connection (A, B). Correct (N)-connection establishment between entity A (user A) and its peer entity (user B) is performed by communicating the service primitives 1 to 4 in the order stated.
+
+![Sequence diagram of (N)-CONNECT service primitives between two users and a provider.](e69b9188aa2c14ec6b21c83f711fef65_img.jpg)
+
+The diagram illustrates the sequence of service primitives for the (N)-CONNECT service. It shows two (N)-service users, user A and user B, interacting with an (N)-service provider. User A's interface is labeled (N)-SAP A and User B's is labeled (N)-SAP B. The sequence of events is as follows:
+
+- 1 (N)-CONNECT request: User A sends a request to the provider.
+- 2 (N)-CONNECT indication: The provider sends an indication to User B.
+- 3 (N)-CONNECT response: User B sends a response to the provider.
+- 4 (N)-CONNECT confirmation: The provider sends a confirmation to User A.
+
+The diagram is identified by the reference T0827100-97.
+
+Sequence diagram of (N)-CONNECT service primitives between two users and a provider.
+
+**Figure 5/T.180 – Sequence of service primitives of the (N)-CONNECT service**
+
+### 7.1.2 Multipeer communication
+
+The primitives described in 7.1.1 will now be used to access services offered in point-to-point environments as well as in multipoint environments. To differentiate between the "pure" OSI semantics of the services and the semantics described in this subclause, the services and the primitives are prefixed by the character X- (e.g. X-CONNECT service).
+
+The X-primitives allow entities to access connection-oriented services at specific service endpoints. These services are:
+
+- connection establishment service (X-CONNECT service);
+- data transfer service (X-DATA service);
+- primitive transfer service (X-SP service);
+- disconnect service (X-DISCONNECT service);
+- orderly release service (X-RELEASE service);
+- information service (X-INFO service).
+
+The semantics of these services are provider dependent. The X-primitives and the sequences of service primitives at a service endpoint are defined in 7.2 (see Figure 10). The introduction of connectionless services is out of the scope of this Recommendation.
+
+A connection is a logical association between two or more entities, enabling communication between them. As an example, and from the viewpoint of a service endpoint, a connection is established by the usage of an allowed sequence of primitives of the X-CONNECT service. Which primitives apply depends on the provider.
+
+A connection between two entities is called a *point-to-point* connection. A connection between more than two entities is called a *multipoint* connection.
+
+In peer-to-peer relationships, two users (applications) may exchange information via a point-to-point connection.
+
+In multipeer-to-multipeer relationships, multiple users (applications) may exchange information via a multipoint connection.
+
+Point-to-point and multipoint environments offer the communication facilities of an underlying provider to users rather than describe the relationship among users.
+
+In point-to-point environments, the negotiation of the user requirements and the provider facilities is usually performed by a single service, the X-CONNECT service. Afterwards, both users may send and receive data using the X-DATA service.
+
+In multipoint environments, negotiating the provider facilities is more complex than in point-to-point environments. Therefore, it may be advantageous to separate the negotiation of the provider facilities from that of the user requirements.
+
+Conference environments may be looked at as multipoint environments, where specific conference providing services are added. Separating conference users from conference providers,
+
+conference users may access:
+
+- conference control services (e.g. getting information on conferences, creating a conference, joining a conference, leaving a conference, etc.); as well as
+- conference application services (e.g. multipoint file transfer, whiteboard, audio, video, device control, etc.); and
+
+conference providers may support:
+
+- conference control (providing the services required from users, controlling the conference resources, ...); as well as
+- application protocols (e.g. protocols providing file transfer, protocols providing whiteboards, protocols providing audio, ...); and
+- multipoint communication.
+
+Application protocols are point-to-point protocols using point-to-point communication functions, or multipoint protocols using multipoint communication functions. Conference control may comprise specific conference management functions (e.g. conference conductorship).
+
+Figure 6 shows an example of a conference, consisting in three conference users A, B, and C, and a conference providing service S, and a conference provider. The service S consists in a user part and a provider part (the latter being part of the conference provider).
+
+![Diagram of a conference environment showing users A, B, and C, a service S, and a conference provider.](f0b7aaa539a2f77c98d53ed6c1c2366b_img.jpg)
+
+The diagram illustrates the architecture of a conference environment. At the top, four entities are shown: 'conference providing service S (user part)', 'conference user A', 'conference user B', and 'conference user C'. Each entity is represented by a box containing three vertical bars: a solid grey bar for 'conference control', a cross-hatched bar for 'application a1', and a horizontally striped bar for 'application a2'. Below these boxes are 'APs' (Application Points) for service S and 'SAPs' (Service Access Points) for users A, B, and C. These are connected to a large horizontal box at the bottom labeled 'conference provider'. A legend at the bottom identifies the bar patterns: solid grey for 'conference control', cross-hatched for 'application a1', and horizontally striped for 'application a2'. The reference 'T0827110-97' is located at the bottom right of the diagram area.
+
+Diagram of a conference environment showing users A, B, and C, a service S, and a conference provider.
+
+**Figure 6/T.180 – Users and provider of an example conference**
+
+The service S (user part and/or provider part) supports conference control services as described above whereas the remainder of the conference provider is concerned with functions of the multipoint environment.
+
+Figure 6 describes the separation of conference users from the conference provider rather than the mapping of user and provider functions on real systems. Figure 7 shows a possible configuration for the example conference, consisting in three terminals and a Multipoint Control Unit (MCU). The multipoint connection (cK, cA, cB, cC) handles the communication between the control entities (e.g. the T.120 Node Controller) of the terminals and the MCU. cX is the name of the control-SAP (or endpoint of the SAP) identifying the control entity residing in system X.
+
+![Diagram of a multipoint connection configuration showing MCU K, Terminal A, Terminal B, and Terminal C. MCU K contains a 'conference providing service S (user part)' and a '(provider part)'. Terminal A, B, and C each contain a 'conference user' and a control entity. The control entities are connected via a common line to the provider part of MCU K. The connection points are labeled cK, cA, cB, and cC.](366a77fdefb0097b3289b4a011911390_img.jpg)
+
+The diagram illustrates a multipoint connection configuration. On the left is 'MCU K', which is divided into a 'conference providing service S (user part)' and a '(provider part)'. The user part contains a control entity labeled 'cK'. To the right are three terminals: 'Terminal A', 'Terminal B', and 'Terminal C'. Each terminal contains a 'conference user' and a control entity labeled 'cA', 'cB', and 'cC' respectively. A horizontal line connects the control entities 'cA', 'cB', and 'cC' to the '(provider part)' of 'MCU K'. The connection points are labeled 'cK', 'cA', 'cB', and 'cC'.
+
+Diagram of a multipoint connection configuration showing MCU K, Terminal A, Terminal B, and Terminal C. MCU K contains a 'conference providing service S (user part)' and a '(provider part)'. Terminal A, B, and C each contain a 'conference user' and a control entity. The control entities are connected via a common line to the provider part of MCU K. The connection points are labeled cK, cA, cB, and cC.
+
+**Figure 7/T.180 – Example configuration: Multipoint connection (cK, cA, cB, cC)**
+
+The address space of the control connection will comprise addresses of control entities of terminals and of other nodes (e.g. MCUs) participating in a conference. The connection may be identified by a list of addresses, or by the name of a list (e.g. a number), or by some other mechanism.
+
+If the conference providing service S is not subdivided in a user part and a provider part (i.e. there is no service access point cK in the example above), then the services of S may be requested by identifying the node or the service in the control connection: (K, cA, cB, cC) or (S, cA, cB, cC) in the example above.
+
+In general, a *control connection* serves for communication between control entities (residing in terminals or in other nodes) and between control entities and provider parts of conference providing services. As an example, creating a conference means establishing a control connection.
+
+Figure 8 shows the multipoint connection (A-a1, B-a1, C-a1), which handles the communication between the entities of the application a1: entities of application a1, residing at different terminals, may communicate in a multipoint fashion with each other. X-ai is the name of the application-SAP (or endpoint of the SAP) identifying the application entity ai residing in system X.
+
+![Figure 8/T.180: Example configuration: Multipoint connection (A-a1, B-a1, C-a1). The diagram shows four entities: MCU K, Terminal A, Terminal B, and Terminal C. MCU K contains a 'conference providing service S' and a '(provider part)'. Terminal A contains a 'conference user A' with three internal components (solid, cross-hatched, and striped rectangles) and a connection point 'A-a1'. Terminal B contains a 'conference user B' with two internal components and a connection point 'B-a1'. Terminal C contains a 'conference user C' with three internal components and a connection point 'C-a1'. A horizontal line connects the '(provider part)' of MCU K to the connection points 'A-a1', 'B-a1', and 'C-a1' of the terminals.](7133ccf78043568ca62ecbcd43628a4a_img.jpg)
+
+Figure 8/T.180: Example configuration: Multipoint connection (A-a1, B-a1, C-a1). The diagram shows four entities: MCU K, Terminal A, Terminal B, and Terminal C. MCU K contains a 'conference providing service S' and a '(provider part)'. Terminal A contains a 'conference user A' with three internal components (solid, cross-hatched, and striped rectangles) and a connection point 'A-a1'. Terminal B contains a 'conference user B' with two internal components and a connection point 'B-a1'. Terminal C contains a 'conference user C' with three internal components and a connection point 'C-a1'. A horizontal line connects the '(provider part)' of MCU K to the connection points 'A-a1', 'B-a1', and 'C-a1' of the terminals.
+
+**Figure 8/T.180 – Example configuration: Multipoint connection (A-a1, B-a1, C-a1)**
+
+In the same way, the multipoint connection (A-a2, C-a2) will handle the communication between the entities of the application a2.
+
+Therefore, these connections are called application connections. Application connections rely on the conference creation process performed earlier.
+
+The address space of an application connection will comprise addresses of application entities. The connection may be identified by a list of addresses, or by the name of a list (e.g. a number), or by some other mechanism.
+
+In general, an *application connection* serves for communication between application entities.
+
+An application connection provides the activities of a *session*. As an example, the members of a session may cooperate via the exchange of files interactively between them using the services of the data transfer phase of an application connection. If supported by the connection, a session may comprise the transfer of more than one data flow (e.g. file transfer) in parallel.
+
+The identification of a connection should remain unchanged even in cases where the members participating in a session will change. Therefore, it might be convenient to identify a connection by a number rather than by listing the addresses of the actual participants.
+
+Figure 9 shows the example configuration together with the three multipoint connections discussed above.
+
+![Figure 9/T.180: Example configuration: Sketching all multipoint connections. This diagram is similar to Figure 8 but shows the internal structure of the entities more fully. MCU K has a '(user part)' box above its '(provider part)'. Terminal A has three internal components and three connection points labeled 'A-a1', 'A-a2', and 'A-a3'. Terminal B has two internal components and two connection points labeled 'B-a1' and 'B-a2'. Terminal C has three internal components and three connection points labeled 'C-a1', 'C-a2', and 'C-a3'. A horizontal line connects the '(provider part)' of MCU K to the first connection point of each terminal (A-a1, B-a1, C-a1).](ea4fd10a9a501c602f2bea0f7f711877_img.jpg)
+
+Figure 9/T.180: Example configuration: Sketching all multipoint connections. This diagram is similar to Figure 8 but shows the internal structure of the entities more fully. MCU K has a '(user part)' box above its '(provider part)'. Terminal A has three internal components and three connection points labeled 'A-a1', 'A-a2', and 'A-a3'. Terminal B has two internal components and two connection points labeled 'B-a1' and 'B-a2'. Terminal C has three internal components and three connection points labeled 'C-a1', 'C-a2', and 'C-a3'. A horizontal line connects the '(provider part)' of MCU K to the first connection point of each terminal (A-a1, B-a1, C-a1).
+
+**Figure 9/T.180 – Example configuration: Sketching all multipoint connections**
+
+As pointed out above, a conference may handle more than one connection. Conference control may be supplied by a separate connection (i.e. control connection). In this case,
+
+- the X-CONNECT service at a control-SAP, identifying the control connection, will be used to establish or join a conference or to invite to a conference; and
+- for each multipoint aware application, the X-CONNECT service at an application-SAP, identifying the specific application connection, will attach the application to the provider and user requirements will be negotiated.
+
+Roughly spoken, the control connection is concerned with the management of the conference environment, and each application connection is concerned with the usage of the conference environment by a specific application.
+
+If no control connection is used, conference control functions are added to application connections.
+
+In any case, each multipoint connection is established by applying the X-CONNECT service. Having applied successfully this service, the connection is in the data transfer phase. The specific semantics of the X-CONNECT service and the services of the data transfer phase depend on the provider.
+
+## **7.2 The state transition diagram as part of the model**
+
+The access to each connection (point-to-point or multipoint) is handled by the usage of the service primitives at appropriate service endpoints. This subclause specifies the service primitives and their sequences possible at some service endpoint (local view). The specification of the interdependencies between service primitives at different service endpoints accessing the same service (global view) is outside the scope of this Recommendation.
+
+Figure 10 shows a state transition diagram, which presents the sequences of service primitives possible at a service endpoint. With this generic type of service any kind of CO OSI service may be accessed as well as CO-oriented non-OSI services such as video (video codecs) or other communication services (e.g. multipoint aware applications or conference systems).
+
+![Figure 10/T.180 – Sequence of service primitives at a service endpoint. This state transition diagram shows the sequence of service primitives at a service endpoint. States are represented by ovals: Idle, Incon, Outcon, Outrel, Inrel, Connected, and any state. Transitions are labeled with service primitives. From Idle to Incon: X-CONIND. From Incon to Idle: X-SNDDIS, X-RCVDIS, X-CONRSP(-). From Idle to Outcon: X-CONREQ. From Outcon to Idle: X-SNDDIS, X-RCVDIS, X-CONCONF(-). From Incon to Connected: X-SNDDIS, X-RCVDIS. From Outcon to Connected: X-CONCONF(+). From Outrel to Connected: X-RELREQ. From Inrel to Connected: X-RELIND. From Connected to Idle: X-CONREQ. From Connected to Incon: X-CONRSP(+). From Connected to Outrel: X-RCVDATA, X-RCVSP. From Connected to Inrel: X-RELIND. From Connected to any state: X-SNDDATA, X-RCVDATA, X-SNDSP, X-RCVSP. From any state to Connected: X-SNDINFO, X-RCVININFO. From Outrel to Idle: X-SNDDIS, X-RCVDIS, X-RELCONF. From Inrel to Idle: X-RCVDIS, X-RELRSP. A self-loop is shown on the 'any state' oval.](aaf3e6e44cdeabd6d1df869c5f392ea1_img.jpg)
+
+```
+
+graph TD
+    Idle((Idle))
+    Incon((Incon))
+    Outcon((Outcon))
+    Outrel((Outrel))
+    Inrel((Inrel))
+    Connected((Connected))
+    any_state((any state))
+
+    Idle -- X-CONIND --> Incon
+    Incon -- "X-SNDDIS  
+X-RCVDIS  
+X-CONRSP(-)" --> Idle
+    Idle -- X-CONREQ --> Outcon
+    Outcon -- "X-SNDDIS  
+X-RCVDIS  
+X-CONCONF(-)" --> Idle
+    Incon -- "X-SNDDIS  
+X-RCVDIS" --> Connected
+    Outcon -- X-CONCONF(+) --> Connected
+    Outrel -- X-RELREQ --> Connected
+    Inrel -- X-RELIND --> Connected
+    Connected -- X-CONREQ --> Idle
+    Connected -- "X-CONRSP(+)" --> Incon
+    Connected -- "X-RCVDATA  
+X-RCVSP" --> Outrel
+    Connected -- "X-SNDDATA  
+X-RCVDATA  
+X-SNDSP  
+X-RCVSP" --> any_state
+    any_state -- "X-SNDINFO  
+X-RCVININFO" --> Connected
+    Outrel -- "X-SNDDIS  
+X-RCVDIS  
+X-RELCONF" --> Idle
+    Inrel -- "X-RCVDIS  
+X-RELRSP" --> Idle
+
+    style any_state fill:none,stroke:none
+
+```
+
+Figure 10/T.180 – Sequence of service primitives at a service endpoint. This state transition diagram shows the sequence of service primitives at a service endpoint. States are represented by ovals: Idle, Incon, Outcon, Outrel, Inrel, Connected, and any state. Transitions are labeled with service primitives. From Idle to Incon: X-CONIND. From Incon to Idle: X-SNDDIS, X-RCVDIS, X-CONRSP(-). From Idle to Outcon: X-CONREQ. From Outcon to Idle: X-SNDDIS, X-RCVDIS, X-CONCONF(-). From Incon to Connected: X-SNDDIS, X-RCVDIS. From Outcon to Connected: X-CONCONF(+). From Outrel to Connected: X-RELREQ. From Inrel to Connected: X-RELIND. From Connected to Idle: X-CONREQ. From Connected to Incon: X-CONRSP(+). From Connected to Outrel: X-RCVDATA, X-RCVSP. From Connected to Inrel: X-RELIND. From Connected to any state: X-SNDDATA, X-RCVDATA, X-SNDSP, X-RCVSP. From any state to Connected: X-SNDINFO, X-RCVININFO. From Outrel to Idle: X-SNDDIS, X-RCVDIS, X-RELCONF. From Inrel to Idle: X-RCVDIS, X-RELRSP. A self-loop is shown on the 'any state' oval.
+
+**Figure 10/T.180 – Sequence of service primitives at a service endpoint**
+
+The semantics of the X-primitives are described below.
+
+This diagram covers the connection establishment phase, the data transfer phase, and the connection release phase. Which services are made available to users depend on the underlying provider.
+
+In the following, the service primitives are described which are supporting these three phases.
+
+The connect service may comprise end-to-end confirmation using the request, the indication, the response, and the confirmation primitives in a peer-to-peer like manner (see Figure 5 for example), or it may comprise some other functionality (i.e. no peer-to-peer confirmation).
+
+In general, applying the connect service will force the local user as well as the provider to switch to the data transfer phase of a connection. This service will address the remote user(s) and/or the provider.
+
+During connection establishment phase (X-CONNECT service), either:
+
+- e1 two users of the same service (i.e. a user and its peer) establish a connection between them, (one user is considered *active* and initiates the connection, while the other user is *passive* and waits for any other service user to request a connection); or
+- e2 a user establishes a control connection to communicate in a control service defined fashion (e.g. to negotiate provider facilities); or
+- e3 a user establishes an application connection (i.e. an application is connected to the provider), which then offers multipoint services to the application; or
+
+- e4 a user establishes a connection combining e2 and e3 services.
+
+The service primitives that are supporting the connection establishment phase are:
+
+- **X-CONREQ** requests a connection to a remote service user (e1), or it requests access to some appropriate server to communicate in a server-defined fashion (e2), or it requests an application to be connected to the provider (e3), or it requests a combined service, consisting in e2 and e3 services. The called user's protocol address(es) or a service-related address is passed as an argument. Additional parameters may be passed as arguments too.
+- **X-CONCONF** is used in conjunction with X-CONREQ to establish a connection or an access to the requested service. X-CONREQ does not wait for an answer from the called user or service. On receipt of the X-CONCONF primitive, the calling user may determine whether or not the request has been accepted by the remote user or by the server.
+- **X-CONIND** indicates a connection request from a remote service user. It provides the calling user's protocol address, maybe some protocol-specific (or service-specific) parameters proposed by the caller, and the user data from the connect indication protocol data unit.
+- **X-CONRSP** is initialized by the passive user to accept a connection or a service after an X-CONIND has been received. Protocol-specific (service-specific) parameters and user data may be submitted as arguments of the X-CONRSP. A negative response may or may not be provided.
+
+Once, a connection has been established, data may be transferred (X-DATA service). There are service primitives to transfer data, and additional service primitives (X-SP service) that serve for different purposes, e.g. they may be used to change the set of capabilities which characterize the communication (e.g. change of QoS). Depending on the provider, transfer of parallel data flow may be supported by the connection. Parallel data may be transferred by the provider due to differing priorities. There are four primitives defined for use in the data transfer phase:
+
+- **X-SNDDATA** enables the user to play the role of a source of user-relevant information. Playing this role data of any type and of any priority (if supported by the service provider) are sent over the connection to the communication partner(s). The data transfer between the peers is controlled by protocol-specific parameters that, usually, have been negotiated in the connection establishment phase. Additional protocol-specific parameters may be specified in the X-SNDDATA.
+- **X-RCVDATA** enables the user to play the role of a sink of user-relevant information. Playing this role data of any type and of any priority are received over the connection which have been sent by the source. Beside the user data, X-RCVDATA may deliver protocol-specific parameters as additional information concerning the user data.
+- **X-SNDSP** enables the user to transfer a protocol-specific service primitive, or other control information, or some other connection-related information to the provider and/or other user(s). Examples are the transfer of information between the applications (e.g. for the OSI Session Provider, the S-TOKEN-PLEASE rq. is transferred to the provider to request a data token from the active side), or the change of the set of capabilities which characterize the communication (e.g. for the H.320 service provider, the mode switch request primitive is passed to the provider to initiate a change of the current transmission mode). In the latter case, it depends on the
+
+provider whether a service primitive is handled completely local (e.g. changing only parameter values of a local codec) or leads to a data transfer. The available service primitives are defined in the descriptions of the appropriate service providers.
+
+- **X-RCVSP** enables the user to receive a protocol-specific service primitive, or other control information, or some other connection related information. The primitive may indicate the receipt of a protocol data unit or may be generated as result of some internal state changes or events in the local service provider. The primitives that may be returned are defined in the descriptions of the appropriate service providers.
+
+Two ways are provided to release a connection: abortive release (X-DISCONNECT service) and orderly release (X-RELEASE service). The abortive release is a mandatory feature and to be supported by all XAPI service providers. The orderly release is an optional feature.
+
+The abortive release may be invoked in the connection establishment phase or the data transfer phase. The abortive release takes effect immediately on request. Once an abortive release has been initiated there is no guarantee that data on the way between a user and its peer(s) will be delivered correctly. They may be lost. Service primitives supporting abortive release are:
+
+- **X-SNDDIS** initiates an abortive release during the data transfer phase or rejects an incoming call during connection establishment. X-SNDDIS takes user data and service primitive parameters as arguments.
+- **X-RCVDIS** may be used during data transfer and connection establishment. The parameters of the X-RCVDIS indicate the reason for the abortive release.
+
+An orderly release may be invoked by either user in the data transfer phase only. The orderly release procedure allows a user and its peer(s) to gracefully release a connection and thus prevents the loss of data that may occur during an abortive release. Orderly release is a confirmed service. In an orderly release, protocol-specific parameters may be negotiated between the user and its peer(s). Conflicts are assumed to be solved by the provider. In the case of multipoint communication, the orderly release causes specific synchronization. The usage of the orderly release service in multipoint environments is for further study. Primitives supporting orderly release are:
+
+- **X-RELREQ** initiates an orderly release during the data transfer phase. The function takes user data and service primitive parameters as arguments, but it is protocol dependent if they are supported by the service provider and will be transferred to the remote user(s) or not. The connection is not terminated before the release confirmation has arrived at the service endpoint and data or service primitives can be received from the endpoint while waiting for the release confirmation. Sending data is not possible in this state.
+- **X-RELCONF** receives a release confirmation from the service endpoint. The primitive may contain user data and service primitive parameters. If a parameter negotiation has been initiated with the X-RELREQ, the negotiation results are contained as service primitive parameters of the release confirmation. The communication is finished with the X-RELCONF. A negative confirmation is not provided by the model.
+- **X-RELIND** receives a release indication from the service endpoint. The primitive may contain the user data and service primitive parameters submitted with the X-RELREQ. The application has to respond to the indication with an X-RELRSP immediately. After reception of the release indication, no more data may be sent.
+
+- **X-RELRSP** responds to a previously received orderly release indication. The primitive takes user data and service primitive parameters as arguments, but it is protocol dependent if they are supported by the service provider or not. If the remote user initiated a parameter negotiation with the release request, the application may respond to the proposals returned by the X-RELIND primitive. The final values for the negotiated parameters have to be specified as service primitive parameters in the X-RELRSP. The communication is finished with the X-RELRSP. Refusing the release with X-RELRSP(–) is not provided by the model.
+
+General information services (e.g. information on conferences that are currently in existence) may be invoked by the user in any state (X-INFO service). In general, these services are not related to some specific connection.
+
+- **X-SNDINFO** initiates an information request.
+- **X-RCVINFO** may be used to receive information.
+
+In Figure 10, there are six possible states for a service endpoint representing the connection establishment phase, the data transfer phase, and the connection release phase:
+
+- **Idle** The service endpoint is active and the connection establishment phase may be performed.
+- **Outcon** The endpoint is engaged in active connection establishment. An outgoing call has been initiated and now a connect confirmation is awaited.
+- **Incon** The endpoint is engaged in passive connection establishment. An incoming connect indication has been received and now a connect response is awaited from the user.
+- **Connected** A connection has been established on this service endpoint which is now in the data transfer phase.
+- **Inrel** An orderly release indication has been received on this endpoint and now a release response is awaited from the user.
+- **Outrel** An orderly release has been initiated on this endpoint by the user and now an orderly release confirmation is awaited.
+
+The states Inrel and Outrel are significant only for services that support orderly release.
+
+# 8 Description of the XAPI
+
+This clause introduces the architecture of the XAPI, the XAPI functions, and the relationship of the functions with respect to the model of communication, which was introduced in clause 7. XAPI offers point-to-point applications as well as multipoint-aware applications a homogeneous access mechanism to communication services.
+
+## 8.1 XAPI in point-to-point and in multipoint environments
+
+As stated in clause 6, the XAPI is a communication interface inside a terminal equipment. It allows a service user to communicate with its respective service provider. The location of the XAPI depends on the choice of the underlying provider.
+
+Looking from the OSI Reference Model to audio or video applications (or to specific data applications), the functionality of some OSI layers is not needed.
+
+These layers are empty in Figure 11.
+
+The left part of Figure 11 shows an ATM service provider offering the "OSI Network Service" (data, or audio, or video) to the XAPI user. The right part of the figure shows an X.25 service provider together with an X.224 service provider offering the OSI transport service to the XAPI user.
+
+![Figure 11/T.180: XAPI Access to the OSI transport service provider and the OSI network service provider. The diagram shows two protocol stacks separated by an XAPI interface. The left stack (OSI network service provider) includes layers 4-7 (Functions), four empty layers, a dashed box for Coordination function, Signal, and Control, another dashed box for Adaptation layer, ATM layer, and Physical layer. The right stack (OSI transport service provider) includes layers 5-7 (Functions), three empty layers, Layer 4 (X.224), Layer 3 (e.g. X.25 packet layer), Layer 2 (e.g. X.25 data link layer), and Layer 1 (e.g. X.21). Brackets on the right group the top layers as 'XAPI user process' and the bottom layers as 'XAPI service provider'. A reference T0827160-97 is at the bottom right.](5d3455c6c2a37cb3aff761fedeb8644e_img.jpg)
+
+Figure 11/T.180: XAPI Access to the OSI transport service provider and the OSI network service provider. The diagram shows two protocol stacks separated by an XAPI interface. The left stack (OSI network service provider) includes layers 4-7 (Functions), four empty layers, a dashed box for Coordination function, Signal, and Control, another dashed box for Adaptation layer, ATM layer, and Physical layer. The right stack (OSI transport service provider) includes layers 5-7 (Functions), three empty layers, Layer 4 (X.224), Layer 3 (e.g. X.25 packet layer), Layer 2 (e.g. X.25 data link layer), and Layer 1 (e.g. X.21). Brackets on the right group the top layers as 'XAPI user process' and the bottom layers as 'XAPI service provider'. A reference T0827160-97 is at the bottom right.
+
+**Figure 11/T.180 – XAPI Access to the OSI transport service provider and the OSI network service provider**
+
+In a conference environment, conference users and conference providers can be distinguished around the XAPI.
+
+Figure 12 shows a Generic Model of a Conference platform together with the concept of separating conference control (using a control connection) and application functions (using application connections) from each other, as described in clause 7.
+
+The conference provider shown in Figure 12 may be looked at as the local part of the conference provider (i.e. the restriction of the provider functionality to a system), as shown in Figure 4.
+
+![Figure 12/T.180 – Generic Model of a Conference platform: Separating conference control and application functions. The diagram shows a horizontal XAPI line connecting two main sections: 'conference user' (top) and 'conference provider' (bottom). In the 'conference user' section, there are boxes for 'conference control (XAPI user)', 'application-1 (XAPI user)', and 'application-n (XAPI user)'. In the 'conference provider' section, there are boxes for 'conference control (provider)', 'application-1 (provider)', and 'application-n (provider)'. Vertical lines connect each user box to its corresponding provider box, labeled 'Fd-cc', 'Fd-a1', and 'Fd-an' respectively. Ellipses between application-1 and application-n indicate multiple applications. The label 'T0827170-97' is at the bottom right.](692541e65db4dc852988ce77ebb60ce5_img.jpg)
+
+Figure 12/T.180 – Generic Model of a Conference platform: Separating conference control and application functions. The diagram shows a horizontal XAPI line connecting two main sections: 'conference user' (top) and 'conference provider' (bottom). In the 'conference user' section, there are boxes for 'conference control (XAPI user)', 'application-1 (XAPI user)', and 'application-n (XAPI user)'. In the 'conference provider' section, there are boxes for 'conference control (provider)', 'application-1 (provider)', and 'application-n (provider)'. Vertical lines connect each user box to its corresponding provider box, labeled 'Fd-cc', 'Fd-a1', and 'Fd-an' respectively. Ellipses between application-1 and application-n indicate multiple applications. The label 'T0827170-97' is at the bottom right.
+
+**Figure 12/T.180 – Generic Model of a Conference platform: Separating conference control and application functions**
+
+The functionality of the providers shown in Figure 12 depends on the specific local part of the conference provider.
+
+From the XAPI point of view this separation is supported by the creation of:
+
+- a (conference) service endpoint (named Fd-cc in Figure 12) specifying a local link between the XAPI user part of the conference control and its provider part; and
+- a (application) service endpoint for each application process (named Fd-a1 to Fd-an in Figure 12) specifying a local link between the user part of an application process and its application protocol instance (provider part).
+
+The interaction of an XAPI user and the corresponding provider at a specific Fd is described by the sequences of XAPI service primitives at that specific service endpoint. For peer-to-peer as well as for multipeer communication (e.g. for conferencing), the same XAPI functions apply for each service endpoint:
+
+- A service endpoint is initialized using the `x_open()` and the `x_bind()` functions.
+- Connection establishment is supported by the `x_conreq()` and the `x_conconf()` functions (or by the `x_conind()` and the `x_conrsp()` functions).
+- The data transfer phase is supported by the `x_snddata()` and `x_rcvdata()`, and/or by the `x_sndsp()` and `x_rcvsp()` functions.
+- Connection release is supported by the `x_snddis()`, or by the `x_rcvdis()` functions (or by the functions of the orderly release).
+- The service endpoint is de-initialized using the `x_unbind()` and the `x_close()` functions.
+- The functions `x_sndinfo()` and `x_rcvinfo()` may be used for transferring appropriate information between user and provider via the XAPI.
+
+NOTE – For conference control as well as for other applications, the connect service may comprise end-to-end confirmation [using the request, the indication, the response, and the confirmation functions in a peer-to-peer like manner (see Figure 3 for example)], or it may comprise minor functionality (i.e. no peer-to-peer confirmation).
+
+According to the Generic Model of a Conference platform (see Figure 12), there is a separate user instance (accessing the provider at the service endpoint Fd-cc) that controls the conference, thus unburdening these functions from all other conference applications. If such an instance does not exist, conference control (if any) has to be handled by some (or by all) multipoint-aware applications. This does not affect the usability of the XAPI: as for other cases, the XAPI user access to some appropriate provider has to be specified in a separate part of Appendix I.
+
+## 8.2 XAPI functions and the corresponding state transition diagram
+
+The XAPI functions may be divided in two classes: the class of communication-related functions and the class of not communication-related functions. Communication-related functions get their specific semantics from the service primitives described in clause 7.
+
+The communication-related XAPI functions together with the corresponding service primitives are listed in Table 1.
+
+**Table 1/T.180 – Communication-related XAPI functions**
+
+| <b>XAPI function</b> | <b>X-primitive</b> |
+|----------------------|--------------------|
+| x_conreq()           | X-CONREQ           |
+| x_conind()           | X-CONIND           |
+| x_conrsp()           | X-CONRSP           |
+| x_conconf()          | X-CONCONF          |
+| x_snddata()          | X-SNDDATA          |
+| x_rcvdata()          | X-RCVDATA          |
+| x_sndsp()            | X-SNDSP            |
+| x_rcvsp()            | X-RCVSP            |
+| x_snddis()           | X-SNDDIS           |
+| x_rcvdis()           | X-RCVDIS           |
+| x_relreq()           | X-RELREQ           |
+| x_relind()           | X-RELIND           |
+| x_relrsp()           | X-RELRSP           |
+| x_relconf()          | X-RELCONF          |
+| x_sndinfo()          | X-SNDINFO          |
+| x_rcvinfo()          | X-RCVINFO          |
+
+The XAPI functions that are not related to communication may be subdivided in two classes: the class of functions supporting the initialization and de-initialization phase, and the class of utility functions.
+
+Table 2 shows the functions supporting initialization and de-initialization and a specific function, indicating explicitly that the local resource management has finished all operations concerning the connection release phase of a connection.
+
+**Table 2/T.180 – XAPI functions supporting initialization/de-initialization**
+
+|            |                                              |
+|------------|----------------------------------------------|
+| x_open()   | create and open a service endpoint           |
+| x_bind()   | activate a service endpoint                  |
+| x_unbind() | deactivate a service endpoint                |
+| x_close()  | close a service endpoint                     |
+| x_rcvend() | receive end indication from service provider |
+
+XAPI utility functions do not change the state of a service endpoint. Table 3 shows a list of the XAPI utility functions (sorted ascending in alphabetical order).
+
+**Table 3/T.180 – List of utility functions**
+
+|              |                                                                                                           |
+|--------------|-----------------------------------------------------------------------------------------------------------|
+| x_b2c()      | select a value of type character string out of a buffer                                                   |
+| x_b2l()      | select a value of type long out of a buffer                                                               |
+| x_c2b()      | write a value of type character string into a buffer                                                      |
+| x_chexmod()  | change execution mode                                                                                     |
+| x_error()    | produce an error message                                                                                  |
+| x_getinfo()  | get protocol-specific information from the service provider                                               |
+| x_look()     | look for the current event on a service endpoint                                                          |
+| x_l2b()      | write a value of type long into a buffer                                                                  |
+| x_optmgmt()  | manage options for a service endpoint                                                                     |
+| x_rcverror() | retrieve error indication from a service provider                                                         |
+| x_strerror() | produce an error message string                                                                           |
+| x_sync()     | synchronize data structures of the XAPI library with the information from the underlying service provider |
+
+Figure 13 shows a state transition diagram that presents the sequences of XAPI functions possible at a service endpoint. XAPI utility functions are not shown. Except for state X\_UNINIT, they may be called in any state. Which functions are made available via the XAPI depends on the specific providers.
+
+![State transition diagram for XAPI function calls showing states X_UNINIT, X_UNBND, X_IDLE, X_WAITEND, X_INCON, X_OUTCON, X_OUTREL, X_INREL, and X_CONNECTED with various function call transitions.](f9c64800d9bace9b4315646d1057be3c_img.jpg)
+
+```
+
+graph TD
+    X_UNINIT([X_UNINIT]) -- x_open() --> X_UNBND([X_UNBND])
+    X_UNBND -- x_close() --> X_UNINIT
+    X_UNBND -- x_bind() --> X_IDLE([X_IDLE])
+    X_IDLE -- x_unbind() --> X_UNBND
+    X_IDLE -- x_conind() --> X_WAITEND([X_WAITEND])
+    X_WAITEND -- x_rcvend() --> X_IDLE
+    X_WAITEND -- x_conreq() --> X_IDLE
+    X_WAITEND -- "x_snddis(), x_rcvdis(), x_conrsp(), \"-\"" --> X_INCON([X_INCON])
+    X_WAITEND -- "x_snddis(), x_rcvdis(), x_conconf(), \"-\"" --> X_OUTCON([X_OUTCON])
+    X_INCON -- "x_snddis(), x_rcvdis()" --> X_WAITEND
+    X_OUTCON -- "x_snddis(), x_rcvdis(), x_conconf(), \"-\"" --> X_WAITEND
+    X_INCON -- x_conrsp() --> X_OUTREL([X_OUTREL])
+    X_OUTCON -- x_conconf() --> X_INREL([X_INREL])
+    X_OUTREL -- "x_rcvdata(), x_rcvsp()" --> X_OUTREL
+    X_INREL -- "x_rcvdis(), x_relrs()" --> X_OUTCON
+    X_OUTREL -- x_relreq() --> X_CONNECTED([X_CONNECTED])
+    X_INREL -- x_relind() --> X_CONNECTED
+    X_CONNECTED -- "x_sndinfo(), x_rcvinfo()" --> AnyState([any state without X_UNINIT and X_UNBND])
+    AnyState -- "x_snddata(), x_rcvdata(), x_sndsp(), x_rcvsp()" --> X_CONNECTED
+    X_CONNECTED -- "x_snddata(), x_rcvdata(), x_sndsp(), x_rcvsp()" --> X_CONNECTED
+  
+```
+
+The diagram illustrates the sequence of XAPI function calls between various states. The states are represented by ovals: X\_UNINIT, X\_UNBND, X\_IDLE, X\_WAITEND, X\_INCON, X\_OUTCON, X\_OUTREL, X\_INREL, and X\_CONNECTED. Transitions are labeled with function names. A self-loop on X\_CONNECTED is labeled with x\_snddata(), x\_rcvdata(), x\_sndsp(), and x\_rcvsp(). A transition from X\_CONNECTED to a state labeled 'any state without X\_UNINIT and X\_UNBND' is labeled with x\_sndinfo() and x\_rcvinfo(). A transition from this state back to X\_CONNECTED is labeled with x\_snddata(), x\_rcvdata(), x\_sndsp(), and x\_rcvsp(). A transition from X\_OUTREL to X\_CONNECTED is labeled with x\_relreq(). A transition from X\_INREL to X\_CONNECTED is labeled with x\_relind(). A transition from X\_OUTCON to X\_INREL is labeled with x\_conconf(). A transition from X\_INCON to X\_OUTREL is labeled with x\_conrsp(). A transition from X\_OUTREL to X\_OUTCON is labeled with x\_rcvdata() and x\_rcvsp(). A transition from X\_INREL to X\_OUTCON is labeled with x\_rcvdis() and x\_relrs(). A transition from X\_OUTCON to X\_WAITEND is labeled with x\_snddis(), x\_rcvdis(), x\_conconf(), and "-". A transition from X\_INCON to X\_WAITEND is labeled with x\_snddis(), x\_rcvdis(), x\_conrsp(), and "-". A transition from X\_WAITEND to X\_IDLE is labeled with x\_rcvend(). A transition from X\_IDLE to X\_WAITEND is labeled with x\_conind(). A transition from X\_WAITEND to X\_IDLE is labeled with x\_conreq(). A transition from X\_IDLE to X\_UNBND is labeled with x\_unbind(). A transition from X\_UNBND to X\_IDLE is labeled with x\_bind(). A transition from X\_UNBND to X\_UNINIT is labeled with x\_close(). A transition from X\_UNINIT to X\_UNBND is labeled with x\_open().
+
+State transition diagram for XAPI function calls showing states X\_UNINIT, X\_UNBND, X\_IDLE, X\_WAITEND, X\_INCON, X\_OUTCON, X\_OUTREL, X\_INREL, and X\_CONNECTED with various function call transitions.
+
+**Figure 13/T.180 – Sequence of XAPI function calls  
+(fragmentation of user data is not shown)**
+
+From the viewpoint of the mapping defined in Table 1, the structure shown in Figure 13 may be looked at as a refinement of the structure shown in Figure 8. The refinement preserves all the sequences of service primitives which are defined in Figure 8.
+
+For each service endpoint, the XAPI has nine possible states:
+
+- X\_UNINIT            The service endpoint is not initialized. This is the initial and the final state.
+- X\_UNBND            The service endpoint is initialized but not activated.
+- X\_IDLE             The service endpoint is active and the connection establishment phase may performed.
+- X\_OUTCON           The endpoint is engaged in active connection establishment. An outgoing call has been initiated and now a connect confirmation is awaited.
+- X\_INCON            The endpoint is engaged in passive connection establishment. An incoming connect indication has been received and now a connect response is awaited from the user.
+- X\_CONNECTED        A connection has been established on this service endpoint which is now in the data transfer phase.
+- X\_INREL            An orderly release indication has been received on this endpoint and now a release response is awaited from the user.
+- X\_OUTREL           An orderly release has been initiated on this endpoint by the user and now an orderly release confirmation is awaited.
+- X\_WAITEND          The connection established on this endpoint has been released. Now the endpoint is waiting for an end indication from the service provider, which indicates that the service provider is ready to establish a new connection.
+
+The states X\_INREL and X\_OUTREL are significant only for services that support orderly release.
+
+Figure 14 shows an example sequence for the communication between two or more users. Fd is the name of the service endpoint, which is created and activated by the usage of the x\_open() and x\_bind() function calls. After having performed this phase successfully, a connection between the user and its peer(s) is established [x\_conreq() and x\_conconf() functions]. In the Data transfer phase data are exchanged between the users [x\_snddata(), x\_rcvdata()]. Afterwards, the connection is released [x\_snddis()], the x\_rcvend() function is performed, and the service endpoint Fd is deactivated [x\_unbind()] and finally destructed [x\_close()].
+
+![](f57c7b37d7a05a99618104f390089f03_img.jpg)
+
+| Phases                             | (multi)peer-to-(multi)peer<br>example sequence                                                                                                                 |
+|------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Phase of local resource management | <div> <div>x_open()<br/>x_bind()</div> <div>Fd</div> </div>                                                                                                    |
+|                                    | <div> <div>Connection establishment phase</div> <div> <div>x_conreq()<br/>x_conconf()</div> <div>at Fd</div> </div> </div>                                     |
+|                                    | <div> <div>Data transfer phase</div> <div> <div> x_snddata()<br/>x_rcvdata()<br/>● ● ●<br/>(exchanging data among users) </div> <div>at Fd</div> </div> </div> |
+|                                    | <div> <div>Connection release phase</div> <div> <div>x_snddis()<br/>x_rcvend()</div> <div>at Fd</div> </div> </div>                                            |
+|                                    | <div> <div> x_unbind()<br/>x_close() </div> <div>Fd</div> </div>                                                                                               |
+
+T0827190-97
+
+**Figure 14/T.180 – Example sequence of XAPI function calls**
+
+Figure 15 shows an example sequence of XAPI function calls for conference purposes together with an example sequence for peer-to-peer communication.
+
+The sequence at the right side consists of two parts of activities, namely an activity which handles participation in a conference (service endpoint Fd-cc and accessory primitives) and an activity which handles applications running in a conference (service endpoint Fd-a1 and accessory primitives). This sequence also applies even to the case of a conference with only two users being involved (point-to-point configuration).
+
+![](e64c7b989e5bdb2708cd7aefd18b06e1_img.jpg)
+
+| Phases                                          | Peer-to-peer<br>example sequence              | Example sequence<br>for conferencing                                                  |                                                                                                  |
+|-------------------------------------------------|-----------------------------------------------|---------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------|
+| Phase of local (conference) resource management |                                               | <div>x_open()<br/>x_bind()<br/>Fd-cc</div>                                            |                                                                                                  |
+|                                                 |                                               | <div>Participation in a conference<br/>x_conreq()<br/>x_conconf()<br/>at Fd-cc</div>  |                                                                                                  |
+|                                                 | Phase of conference management                |                                                                                       | <div>x_open()<br/>x_bind()<br/>Fd-a1</div>                                                       |
+|                                                 |                                               | Connection establishment phase                                                        | <div>x_conreq()<br/>x_conconf()<br/>at Fd</div>                                                  |
+|                                                 |                                               |                                                                                       | <div>x_conreq()<br/>x_conconf()<br/>at Fd-a1</div>                                               |
+|                                                 |                                               | Data transfer phase                                                                   | <div>x_snddata()<br/>x_rcvdata()<br/>● ● ●<br/>(exchanging data among two users)<br/>at Fd</div> |
+|                                                 | Connection release phase                      | <div>x_snddis()<br/>x_rcvend()<br/>at Fd</div>                                        |                                                                                                  |
+|                                                 |                                               | <div>x_unbind()<br/>x_close()<br/>Fd</div>                                            |                                                                                                  |
+|                                                 |                                               | <div>x_unbind()<br/>x_close()<br/>Fd-a1</div>                                         |                                                                                                  |
+|                                                 |                                               | <div>Disconnecting from a conference<br/>x_rcvdis()<br/>x_rcvend()<br/>at Fd-cc</div> |                                                                                                  |
+|                                                 | <div>x_unbind()<br/>x_close()<br/>Fd-cc</div> |                                                                                       |                                                                                                  |
+
+T0827200-97
+
+**Figure 15/T.180 – Two example sequences of XAPI function calls for peer-to-peer and for conferencing**
+
+As can be seen from the example, the latter sequences of function calls may coincide with those defined in the peer-to-peer case.
+
+Conference management services (see Figure 15) may be required at any instant of time after having created a conference (e.g. adding an additional node to an existing conference). So the phase of conference management will encompass the inner phases:
+
+- local application resource management;
+- connection establishment;
+- data transfer; and
+- connection release.
+
+Users may join or leave a running conference and applications may be added to or removed from a conference. These operations do not only affect the phases connection establishment, data transfer, and connection release, but will require operations of the local application resource management too. Last, but not least, the phase of local conference resource management may be influenced by these operations and, therefore, it may encompass all other phases.
+
+# 9 XAPI functions
+
+The XAPI functions may be divided in two classes: the class of communication-related functions and the class of not communication-related functions. The communication-related functions are described in 9.2. The XAPI functions that are not related to communication may be subdivided in two classes: the class of functions supporting the initialization and de-initialization phase, described in 9.3.1, and the class of utility functions, described in 9.3.2.
+
+A list of the XAPI functions is given in 8.2. Figure 13 shows the state transition diagram.
+
+Annex A contains an IDL description of the XAPI. A list of error codes that may be returned by the XAPI functions is given in Annex B.
+
+### General buffer format
+
+Figure 16 shows the general buffer format.
+
+Several entries can be concatenated in one buffer. Three types of buffers are used: Option, service primitive parameter, or address buffers. The value of an entry immediately follows the entry header with no padding or alignment characters in between. The header consists of three members: *len*, *name*, and *status*.
+
+The *len* field gives the total length of the entry. This comprises the entry header and the entry value.
+
+The *name* field identifies the entry.
+
+The *status* field is used to indicate success or failure of an option negotiation (see function *x\_optmgmt*); is it not used for service primitive parameter and address buffers.
+
+![Diagram of the general buffer format showing two concatenated entries. Each entry has a header with len, name, and status, followed by a value field. The first entry is followed by alignment characters. The second entry is followed by an ellipsis indicating further entries.](f10dc32e3673e1392029a49e958a9d6c_img.jpg)
+
+| first entry |      |        |       |                         | second entry |      |        |       |     |  |
+|-------------|------|--------|-------|-------------------------|--------------|------|--------|-------|-----|--|
+| len         | name | status | value | alignment<br>characters | len          | name | status | value | ... |  |
+
+Diagram of the general buffer format showing two concatenated entries. Each entry has a header with len, name, and status, followed by a value field. The first entry is followed by alignment characters. The second entry is followed by an ellipsis indicating further entries.
+
+T0827210-97
+
+**Figure 16/T.180 – General buffer format**
+
+For reading and writing buffer entries, the functions *x\_b2c()*, *x\_b2l()*, *x\_c2b()*, and *x\_l2b()* are helpful. The reading functions *x\_b2c()* and *x\_b2l()* will return the *len*, *name*, *status*, and *value* of the entry and an index to the next entry. The writing functions *x\_c2b()* and *x\_l2b()* take *len*, *name*, and *value* as arguments, write them into the buffer and return an index to the next entry.
+
+### Protocol options
+
+The protocol options are introduced in XAPI as a flexible mechanism to exchange protocol information between the user and the service provider. It enables the user to express special wishes about the settings of some protocol parameters and it allows the service provider to pass information about the protocol parameters used to the user. Protocol options are used to control the general behaviour of a protocol module or to temporarily override some configuration parameters. Each option is specific for a certain protocol module. They must not be confounded with service primitive parameters.
+
+The XAPI function *x\_optmgmt()* is the only one that conveys options between the service user and the service provider. Except for the XAPI-level options described below, all options are passed transparently between provider and user. The XAPI is the carrier only. The options are interpreted, processed, managed, and stored by the provider.
+
+The service provider has a default value for each option it supports. These defaults are sufficient for the majority of communication relations. Hence, a user should only request options actually needed to perform the task and leave all others at their default value.
+
+Each option is characterized by several attributes.
+
+### Option attributes
+
+*Connection-related* options are intimately related to a particular connection in a connection-mode service. Connection-related options are usually negotiated between the two peer entities during connection setup. Therefore, some ancillary information is transferred from the calling entity to the called entity and back in most cases. The interpretation and further processing of this information is protocol-dependent.
+
+An option can have purely local relevance. *Local options* are negotiated solely between the service user and the local service provider. The remote entity is neither informed about the settings of local options nor influenced by these options.
+
+Options that are not connection-related do not contain information destined for the remote service user. Some can have only local relevance; others have external relevance as they influence the transmission of data.
+
+An option can either or not be an *absolute requirement*. This is explicitly defined for each option. An absolute requirement must not be diminished or changed by the service provider. In some cases an option is partly absolute.
+
+An option can be restricted to *read-only access* in some, or all, states of the service endpoint.
+
+The *scope* of an option defines the period of time during which the option is in effect. The lifetime of an option is the time the option has a value assigned and can be accessed by the user. The lifetime is restricted to the time the service provider is accessible through a service endpoint. After the return of *x\_open()*, all options are set to their default values. They will lose their values when the last endpoint accessing the service provider is closed. Do not confound the scope of an option with its lifetime. The scope is limited to the time the option is in effect.
+
+There are two classes of scope. Each option belongs to one and only one of these classes. The widest scope possible is called *permanent scope*. It comprises the whole lifetime of the option. The scope of connection-related options is the time the connection exists. Some connection-related options have an even smaller scope as they are restricted to the data transfer phase of the connection. They come out of scope when connection release is initiated, i.e. the service endpoint leaves the state *X\_CONNECTED*. Options retain their values while they are out of scope. The next time they come into scope, they will start with the old value, which may be different from the default value.
+
+### Option negotiation
+
+A service user can initiate an option negotiation with a call to *x\_optmgt()* with the NEGOTIATE flag set in the *flags* field of the input parameter *req*.
+
+The negotiation rules depend on whether an option is an absolute requirement or not. If the proposed option value is legal and an absolute requirement, the following two outcomes are possible:
+
+The negotiation succeeds and the option is set to the required value; *x\_optmgt()* successfully returns and reports SUCCESS in the *status* field of the option header.
+
+The negotiation is rejected if the option is supported but the proposed value cannot be accepted. *x\_optmgt()* will successfully return in this case, but report FAILURE in the *status* field of the option header.
+
+If the proposed option value is legal but not an absolute requirement:
+
+The negotiated value is of equal or less quality than the proposed value. *x\_optmgt()* will indicate this in the *status* field of the output option. SUCCESS indicates that the proposed value could be negotiated; PARTSUCCESS indicates that the proposed value was diminished.
+
+If the *name* field of the header is unknown to the protocol module selected by *level*, or if the option is not supported at all, the function *x\_optmgt()* succeeds, but reports NOTSUPPORT in the *status* field of this option on return.
+
+Not all options are independent from one another. A requested option might conflict with the value of another option. Therefore, options that depend on one another must not be negotiated independently, but have to be submitted all together in one *x\_optmgt()* call to avoid temporary inconsistencies or conflicts. Thus conflicts can be detected at negotiation time. If only one of two or more dependent options shall be set to a new value, all the dependent options have to be negotiated in one *x\_optmgt()* call, even if their values need not to be changed. If a conflict between dependent options is detected by the service provider, *x\_optmgt()* will successfully return, but report FAILURE in the *status* field of the concerned options.
+
+If the service user submits multiple options in one call and one option is not supported by the service provider, all other options within the buffer are not influenced by this and the legal options are negotiated as usual.
+
+A violation of access rights occurs when the user tries to negotiate an option which is restricted to read-only access. The function *x\_optmgt()* will return successfully in this case, but the option is not changed and READONLY is returned in the *status* field of this option.
+
+If the service user submits multiple options in one call and one of them causes a violation of access rights, all other options within the buffer are not influenced by this and the legal options are negotiated as usual.
+
+As *x\_optmgt()* handles options for one module only, multi-module conflicts cannot be detected at negotiation time. It is left for the user to avoid conflicts between options of different protocol modules.
+
+### XAPI-level options
+
+There is only one XAPI-level option: the trace option O\_TRACE. It switches on/off traces in XAPI functions and protocol modules. The *level* argument in the *x\_optmgt()* call selects the target module. The XAPI functions are selected with *level* XAPI\_LEVEL. For protocol modules, the protocol module identifier has to be used as *level*.
+
+The option value specifies the trace level which controls the amount of traces generated.
+
+The following trace levels are defined:
+
+- `OV_NOTRACE` switches all traces off (default value);
+- `OV_BUFFTRACE` enables the buffer trace for received and sent PDUs; all trace messages are disabled;
+- `OV_ERR` enables error trace messages and disables buffer traces;
+- `OV_ERR_BUF` enables error trace messages plus buffer traces;
+- `OV_WRN` enables error and warning trace messages; buffer traces are disabled;
+- `OV_WRN_BUF` enables error and warning trace messages plus buffer traces;
+- `OV_INF` enables error, warning, and information trace messages; buffer traces are disabled;
+- `OV_INF_BUF` enables error, warning, and information trace messages plus buffer traces.
+
+Buffer traces and trace messages cannot be switched independently. A change in the `O_TRACE` option value always effects both categories. The combinations of the different levels of message traces and buffer traces may be calculated by the user with the bitwise-OR operator.
+
+### Option attributes
+
+The option `O_TRACE`
+
+- is an absolute requirement;
+- is not connection related;
+- has only local meaning;
+- has permanent scope.
+
+The way to access the generated trace data depends on the base operating system.
+
+Note that the error messages generated by the service provider are not affected by the trace level. These error messages are generated whenever an error condition is detected. Usually, they will be written to a system-specific error log file.
+
+## 9.1 Conventions
+
+The description of the XAPI functions, their parameters and fields is independent of hardware and operating systems.
+
+For each XAPI function, a list of parameters is specified.
+
+The meaning of the functions and parameters is described for two types of providers:
+
+- point-to-point (abbreviation p-p);
+- multipoint (mp) with the two types of endpoints being supported: the conference control (abbreviation mp-c) and the application endpoint (mp-a).
+
+If there is a different meaning for the function or parameters of the supported endpoints of the provider types, this is noticed. If there is only one description for a function or parameter, it is meaningful for all types of the supported endpoints.
+
+In a multipoint environment, all communication-related functions at application endpoints are only available if the conference control endpoint is in the active state.
+
+Different providers may cause the specification of provider-specific parameters and/or sets of values for these parameters.
+
+For each specific provider, a separate part of Appendix I describes the XAPI functions, their parameters, and values.
+
+The description of the XAPI functions in the following subclauses is in an alphabetical order.
+
+## 9.2 Communication-related functions
+
+For each XAPI function, the relation between the function and the accessory service primitive is defined. Afterwards, a description of the parameters of the XAPI function is given.
+
+### 9.2.1 X-CONCONF/x\_conconf
+
+**Description:** This primitive enables the XAPI user to determine the status of a previously sent connect request and is used in conjunction with X-CONREQ. In the case of a positive connect confirm, the service endpoint changes to state "Connected". If the service provider supports the capability of negative connect responses (confirm), then an appropriate information may be returned to indicate that the communication was not accepted. In this case, the service endpoint will be in state "Idle".
+
+The meaning of a positive X-CONCONF is for:
+
+*p-p*: a connection between peer entities is established
+
+*mp-c*: a control connection to a conference service provider and to other conference members is established
+
+*mp-a*: the access of an application to a session in an active conference is established
+
+**Function in XAPI:**
+
+**Name:** x\_conconf(fd, call, xerror)
+
+**Parameters:**
+
+*fd*: Identification of the local service endpoint where the active connection establishment has been initiated with *x\_conreq*
+
+*call*: The parameter *call* contains information related to the newly established connection. It is structured in the following parameters:
+
+- *address*: contains address information
+  - p-p*: specifies the responding protocol address, i.e. the address of the responding service user
+  - mp-c*: specifies the address of the conference service provider and may contain a list of active conference members
+  - mp-a*: not used
+- *parameter*: contains the protocol specific parameters
+  - p-p*: protocol-specific parameters of the peer-to-peer connection establishment
+  - mp-c*: Conference-specific parameters
+  - mp-a*: session and application-specific parameters
+- *user\_data*: contains optional data
+  - p-p*: contains any user data that are received from the responding user
+  - mp-c*: additional conference-specific information received from the conference service provider (e.g. information about authentication, billing) and other conference members
+  - mp-a*: additional information of the local application service provider
+- *sequence*: no meaning
+- *flags*: to indicate a local segmentation of information at the interface, or a negative connect confirmation
+
+*xerror*: Error codes
+
+Return value: indicates successful completion or failure
+
+### 9.2.2 X-CONIND/x\_conind
+
+Description: X-CONIND enables a passive user to initiate connection establishment. This service primitive may be diverted from an X-CONREQ. After the receipt of this primitive, the endpoint changes to state "Incon".
+
+The meaning for:
+
+*p-p*: indicates the passive user to establish a connection between the active user and itself
+
+*mp-c*: invitation to conference
+
+*mp-a*: indicates an application that it may use an application connection belonging to a conference to facilitate communication between all or a group of conference members
+
+Function in XAPI:
+
+Name: x\_conind(fd, call, xerror)
+
+Parameters:
+
+*fd*: Identification of the local service endpoint where the passive connection establishment is initiated with *x\_conind*
+
+*call*: The parameter *call* contains information related to the new connection which will be established. It is structured in the following parameters:
+
+- *called\_addr*: contains address information of the called user
+- *calling\_addr*: contains address information of the calling user
+- *parameter*: contains the protocol-specific parameters
+  - p-p*: protocol specific parameters transferred in the connect indication primitive
+  - mp-c*: Conference specific parameters
+  - mp-a*: session- and application-specific parameters
+- *user\_data*: contains optional data
+  - p-p*: contains any user data transferred from the calling to the called user
+  - mp-c*: additional conference-specific information sent to the conference service provider or other conference members (e.g. information about authentication, billing)
+  - (*mp-a*): additional information to the application
+- *sequence*: local unique identification number of the connect indication
+- *flags*: to indicate a local segmentation at the interface or a negative connect confirmation
+
+*xerror*: Error codes
+
+Return value: indicates successful completion or failure
+
+### 9.2.3 X-CONREQ/x\_conreq
+
+Description: This primitive enables a user to initiate active communication establishment. The communication establishment is initialized and the endpoint changes to state "Outcon".
+
+The meaning for:
+
+*p-p*: to establish a connection to another peer entity
+
+*mp-c*: to establish a control connection to a conference service provider and to other conference members
+
+*mp-a*: the application wants to use an application connection belonging to a conference to facilitate communication between all or a group of conference members
+
+Function in XAPI:
+
+Name: x\_conreq(fd, sndcall, xerror)
+
+Parameters:
+
+*fd*: The identification of the local service endpoint where the communication will be established
+
+*sndcall*: The parameter *sndcall* specifies information needed by the service provider to establish the communication. It is structured in the following parameters:
+
+- *address*: contains address information
+  - p-p*: specifies the destination protocol address, i.e. the address of the called service user
+  - mp-c*: specifies the address of the conference service provider and may contain a list of conference members to be invited
+  - mp-a*: not used
+- *parameter*: contains the protocol-specific parameters that should be used in connection establishment
+  - p-p*: protocol-specific parameters needed for peer-to-peer connection establishment
+  - mp-c*: Conference-specific parameters
+  - mp-a*: session- and application-specific parameters
+- *user\_data*: contains optional data
+  - p-p*: contains any user data that shall be sent to the called user with the connect request
+  - mp-c*: additional information for the conference service provider or other conference members
+  - mp-a*: additional information to the local session service provider
+- *sequence*: no meaning
+- *flags*: to indicate a local segmentation at the interface
+
+*xerror*: Error codes
+
+Return value: indicates successful completion or failure
+
+### 9.2.4 X-CONRSP/x\_conrsp
+
+Description: This primitive is issued by a service user to respond to a previously received connect indication. The communication establishment is now complete for the passive user and the endpoint changes to state "Connected". The service provider may or may not support the capability to send negative connect responses. In the case of a negative response, no communication is established and the service endpoint will be in state "Idle".
+
+The meaning is for:
+
+*p-p*: the passive user responds to the indication to establish a connection
+
+*mp-c*: the member responds to an invitation to a conference
+
+*mp-a*: the application responds to the invitation that it may use an application connection belonging to a conference to facilitate communication between all or a group of conference members
+
+Function in XAPI:
+
+Name: x\_conrsp(fd, resfd, call, xerror)
+
+Parameters:
+
+- fd*: The parameter *fd* identifies the service endpoint where the connect indication arrived
+- resfd*: *Resfd* specifies the local service endpoint where the connection is to be established. A service user may accept a connection on either the same, or on a different, local service endpoint than the one on which the connect indication arrived. Before the connection can be accepted on the same endpoint (*resfd* = *fd*), the user must have responded to any previous connect indications received on that service endpoint. If a different service endpoint is specified (*resfd* ≠ *fd*), then both endpoints must refer to the same service provider.
+- call*: The parameter *call* contains information related to the new connection which will be established. It is structured in the following parameters:
+- *address*: contains address information
+    - p-p*: specifies the responding protocol address, i.e. the address of the responding service user
+    - mp-c*: specifies the address of the conference service provider and may contain a list of active conference members
+    - mp-a*: specifies all or a group of the actual in the session active conference members (session-members)
+  - *parameter*: contains the protocol-specific parameters
+    - p-p*: protocol-specific parameters of the peer-to-peer connection establishment
+    - mp-c*: Conference-specific parameters
+    - mp-a*: session- and application-specific parameters
+  - *user\_data*: contains optional data
+    - p-p*: any user data that are received from the responding user
+    - mp-c*: additional conference-specific information received from the conference service provider (e.g. information about authentication, billing) and other conference members
+    - mp-a*: additional information to be passed to the local session service provider
+  - *sequence*: local unique identification number which corresponds to the connect indication
+  - *flags*: to indicate a local segmentation at the interface or a negative connect confirmation
+- xerror*: Error codes
+- Return value: indicates successful completion or failure
+
+#### 9.2.5 X-RCVDATA/x\_rcvdata
+
+Description: This primitive offers the user either normal or expedited data or data with a specific priority. This service primitive does not change the state of the service endpoint.
+
+The meaning is for:
+
+- p-p*: the user receives data from the peer user
+- mp-c*: the conference member receives conference-specific information from another conference member
+- mp-a*: the session member receives data or application-specific information from another session member
+
+Function in XAPI:
+
+Name: x\_rcvdata(fd, data, flags, xerror)
+
+Parameters:
+
+*fd*: Identification of the service endpoint
+
+*data*: The parameter *data* contains the received data and related protocol-specific information. It is structured in the following parameters:
+
+- *parameter*: additional information about the data
+- *p-p*: service primitive parameters which provide additional information about the user data
+- *mp-c*: additional information about the conference data (e.g. identification of the sending conference member)
+- *mp-a*: additional information about the session data (e.g. identification of a dataflow, if more than one dataflow is provided in the session; the identification of the sending session member)
+- *data*: the received data
+
+*flags*: indication of a local segmentation at the interface and the priority of the data
+
+*p-p*: indication of expedited data
+
+*mp-c*: priority of the data
+
+*mp-a*: priority of the data
+
+*xerror*: Error codes
+
+Return value: indicates successful completion or failure
+
+#### 9.2.6 X-RCVDIS/x\_rcvdis
+
+Description: This primitive informs the user that a disconnect condition has occurred. A disconnect is an abortive release. The service primitive X-RCVDIS indicates the end of the data transfer phase. The endpoint changes to state "Idle".
+
+The meaning is for:
+
+*p-p*: the end of the connection
+
+*mp-c*: no longer member in the conference
+
+*mp-a*: no longer member in the session
+
+Function in XAPI:
+
+Name: x\_rcvdis(fd, disc, xerror)
+
+Parameters:
+
+*fd*: Identification of the service endpoint
+
+*disc*: The parameter *disc* contains disconnect related information. It is structured in the following parameters:
+
+- *user\_data*:
+  - p-p*: contains user data of the other user
+  - mp-c*: contains user data of the conference providing service perhaps created by another conference member
+  - mp-a*: contains user data of another session member
+- *parameter*: contains service primitive parameters about the reason for disconnecting
+- *origination*: specifies the origin of the disconnect
+
+- *sequence*: local unique identification number which corresponds to a connect indication. It is only meaningful in the case where the indication is immediately followed by the disconnect.
+
+*xerror*: Error codes
+
+Return value: indicates successful completion or failure
+
+#### 9.2.7 X-RCVINFO/x\_rcvinfo
+
+Description: The X-RCVINFO primitive is used to receive appropriate information from the provider. This service primitive does not change the state of the service endpoint. It is allowed in all states except the states "Uninit" and "Unbnd".
+
+Function in XAPI:
+
+Name: x\_rcvinfo(fd, level, info, par, flags, xerror)
+
+Parameters:
+
+*fd*: Identification of the service endpoint
+
+*level*: Identification of the protocol module which generated the service primitive. This is one of the protocol module IDs which are available
+
+*info*: Identification of the name of the protocol-specific service primitive  
+*p-p*: not used  
+*mp-c*: e.g. Information services for the conference  
+*mp-a*: e.g. Information services for the session
+
+*par*: contains the parameters and user data of the service primitive
+
+- *parameter*: contains the parameters of the service primitive  
+*p-p*: not used  
+*mp-c*: e.g. parameters of the conference-specific information service  
+*mp-a*: e.g. parameters of the session-specific information service
+- *data*: contains the user data of the service primitive
+
+*flags*: indication of a local segmentation at the interface
+
+*xerror*: Error codes
+
+Return value: indicates successful completion or failure
+
+#### 9.2.8 X-RCVSP/x\_rcvsp
+
+Description: The X-RCVSP primitive is used to receive a protocol-specific service primitive. This service primitive does not change the state of the service endpoint. It is only allowed in the states "Connected" and "Outrel".
+
+Function in XAPI:
+
+Name: x\_rcvsp(fd, level, spname, sp, flags, xerror)
+
+Parameters:
+
+*fd*: Identification of the service endpoint
+
+*level*: Identification of protocol module which generated the service primitive. This is one of the protocol module IDs which are available
+
+*spname*: Identification of the name of the protocol-specific service primitive  
+*p-p*: (e.g. in the OSI-session protocol S-TOKEN-PLEASE service)  
+*mp-c*: Conference-specific services  
+*mp-a*: Session-specific services
+
+*sp*: contains the parameters and user data of the service primitive
+
+- *parameter*: contains the parameters of the service primitive
+- p-p*: contains the parameters of the service primitive
+- mp-c*: e.g. identification of the sending conference member
+- mp-a*: e.g. identification of a dataflow; if more than one dataflow is provided in the session, the identification of the sending session member
+- *data*: contains the user data of the service primitive
+
+*flags*: indication of a local segmentation at the interface
+
+*xerror*: Error codes
+
+Return value: indicates successful completion or failure
+
+#### 9.2.9 X-RELCONF/x\_relconf
+
+Description: The X-RELCONF primitive is used to receive the confirmation for a previously requested orderly release. The endpoint changes to state "Idle". This primitive is only used in a point-to-point configuration. The use in a multipoint environment is for further study.
+
+Function in XAPI:
+
+Name: x\_relconf(fd, rel, xerror)
+
+Parameters:
+
+*fd*: Identification of the service endpoint
+
+*rel*: contains protocol-specific parameters and the user data
+
+- *parameter*: contains the release confirmation service primitive
+- *user data*: contains user data of the remote peer entity
+- *flags*: indication of a local segmentation at the interface
+
+*xerror*: Error codes
+
+Return value: indicates successful completion or failure
+
+#### 9.2.10 X-RELIND/x\_relind
+
+Description: The X-RELIND primitive is used to receive a release indication. This indicates the end of the data transfer on this connection to the user. After reception of a release indication, the user may not send any more data over the connection. The endpoint changes to state "Inrel". This primitive is only used in a point-to-point configuration. The use in a multipoint environment is for further study.
+
+Function in XAPI:
+
+Name: x\_relind(fd, rel, xerror)
+
+Parameters:
+
+*fd*: Identification of the service endpoint
+
+*rel*: contains protocol-specific parameters and the user data
+
+- *parameter*: contains the release indication service primitive
+- *user data*: contains user data of the remote peer entity
+- *flags*: indication of a local segmentation at the interface
+
+*xerror*: Error codes
+
+Return value: indicates successful completion or failure
+
+#### 9.2.11 X-RELREQ/x\_relreq
+
+**Description:** The X-RELREQ primitive enables a user to initiate an orderly release of an existing connection and indicates to the service provider that there is no more data to send. The endpoint changes to state "Outrel". However, a user may continue to receive data until the confirmation for the orderly release request has arrived at the service endpoint. This primitive is only used in a point-to-point configuration. The use in a multipoint environment is for further study.
+
+Function in XAPI:
+
+Name: x\_relreq(fd, rel, xerror)
+
+Parameters:
+
+*fd*: Identification of the service endpoint  
+*rel*: contains protocol-specific parameters and the user data  
+– *parameter*: contains the release request service primitive  
+– *user data*: contains user data  
+– *flags*: indication of a local segmentation at the interface  
+*xerror*: Error codes
+
+Return value: indicates successful completion or failure
+
+#### 9.2.12 X-RELRSP/x\_relrsp
+
+**Description:** The X-RELRSP primitive responds to a previously received release indication. The endpoint changes to state "Idle". This primitive is only used in a point-to-point configuration. The use in a multipoint environment is for further study.
+
+Function in XAPI:
+
+Name: x\_relrsp(fd, rel, xerror)
+
+Parameters:
+
+*fd*: Identification of the service endpoint  
+*rel*: contains protocol-specific parameters and the user data  
+– *parameter*: contains the release response service primitive  
+– *user data*: contains user data  
+– *flags*: indication of a local segmentation at the interface  
+*xerror*: Error codes
+
+Return value: indicates successful completion or failure
+
+#### 9.2.13 X-SNDDATA/x\_snddata
+
+**Description:** This primitive is used to send either normal or expedited data or data with a specific priority. This service primitive does not change the state of the service endpoint.
+
+The meaning is for:
+
+*p-p*: the user sends data to the peer user
+
+*mp-c*: the conference member sends conference-specific information to one, a group or all other conference members
+
+*mp-a*: the session member sends application-specific information (data) to a group or all other session members
+
+Function in XAPI:
+
+Name: x\_snddata(fd, data, flags, xerror)
+
+Parameters:
+
+*fd*: Identification of the service endpoint
+
+*data*: The parameter *data* contains the data to be sent and related protocol-specific information. It is structured in the following parameters:
+
+- *parameter*: additional information about the data
+- *p-p*: service primitive parameters which provide additional information about the user data
+- *mp-c*: additional information about the conference data (e.g. identification of the receiving conference member)
+- *mp-a*: additional information about the session data (e.g. identification of a dataflow; if more than one dataflow is provided in the session, the identification of the sending session member)
+- *data*: the data to be sent
+
+*flags*: indication of a local segmentation at the interface and the priority of the data
+
+*p-p*: indication of normal or expedited data
+
+*mp-c*: priority of the data
+
+*mp-a*: priority of the data
+
+*xerror*: Error codes
+
+Return value: indicates successful completion or failure
+
+#### 9.2.14 X-SNDDIS/x\_snddis
+
+Description: This primitive is used to initiate an abortive release. Upon successful return, the endpoint changes to state "Idle".
+
+The meaning is for:
+
+*p-p*: the end of the connection
+
+*mp-c*: the member leaves the conference
+
+*mp-a*: the member leaves the session
+
+Function in XAPI:
+
+Name: x\_snddis(fd, disc, xerror)
+
+Parameters:
+
+*fd*: Identification of the service endpoint
+
+*disc*: The parameter *disc* contains disconnect-related information. It is structured in the following parameters:
+
+- *user\_data*: contains user data
+- *p-p*: the user may send disconnect-related user data to the peer user
+- *mp-c*: the conference member may send disconnect-related user data to the conference providing service and so perhaps to other conference members
+- *mp-a*: the session member may send disconnect-related user data to other session members
+- *parameter*: contains service primitive parameters about the reason of disconnecting
+- *origination*: no meaning
+
+- *sequence*: local unique identification number which corresponds to a connect indication. It is only meaningful when X-SNDDIS is an answer to a connect indication
+
+*xerror*: Error codes
+
+Return value: indicates successful completion or failure
+
+#### 9.2.15 X-SNDINFO/x\_sndinfo
+
+Description: The X-SNDINFO primitive is used to send appropriate information to the provider. This service primitive does not change the state of the service endpoint. It is allowed in all states except the states "Uninit" and "Unbnd".
+
+Function in XAPI:
+
+Name: x\_sndinfo(fd, level, info, par, flags, xerror)
+
+Parameters:
+
+*fd*: Identification of the service endpoint
+
+*level*: Identification of the protocol module which shall get the info. This is one of the protocol module IDs which are available
+
+*info*: Identification of the name of the protocol-specific service primitive  
+*p-p*: not used  
+*mp-c*: e.g. Information services for the conference  
+*mp-a*: e.g. Information services for the session
+
+*par*: contains the parameters and user data of the service primitive
+
+- *parameter*: contains the parameters of the service primitive  
+*p-p*: not used  
+*mp-c*: e.g. parameters of the conference-specific information service  
+*mp-a*: e.g. parameters of the session-specific information service
+- *data*: contains the user data of the service primitive
+
+*flags*: indication of a local segmentation at the interface
+
+*xerror*: Error codes
+
+Return value: indicates successful completion or failure
+
+#### 9.2.16 X-SNDSP/x\_sndsp
+
+Description: The X-SNDSP primitive is used to pass a protocol-specific service primitive to the service provider. The primitive does not change the state of the service endpoint. It is only allowed in the state "Connected".
+
+Function in XAPI:
+
+Name: x\_sndsp(fd, level, spname, sp, flags, xerror)
+
+Parameters:
+
+*fd*: Identification of the service endpoint
+
+*level*: Identification of protocol module which shall get the service primitive. This is one of the protocol module IDs which are available
+
+*spname*: Identification of the name of the protocol-specific service primitive  
+*p-p*: e.g. in the OSI-session protocol S-TOKEN-PLEASE service  
+*mp-c*: Conference-specific services  
+*mp-a*: Session-specific services
+
+*sp*: contains the parameters and user data of the service primitive
+
+- *parameter*: contains the parameters of the service primitive
+- *p-p*: contains the parameters of the service primitive
+- *mp-c*: e.g. identification of the receiving conference member
+- *mp-a*: e.g. identification of a dataflow; if more than one dataflow is provided in the session, the identification of the sending session member
+- *data*: contains the user data of the service primitive
+
+*flags*: indication of a local segmentation at the interface
+
+*xerror*: Error codes
+
+Return value: indicates successful completion or failure
+
+## 9.3 Not communication-related functions
+
+### 9.3.1 Functions for the initialization and de-initialization phase
+
+A description of the functions for the initialization and de-initialization phase is given.
+
+##### 9.3.1.1 x\_bind
+
+**Description:** This function executes in two steps: first, link a transport system; second, associate a protocol address to the service endpoint identified by *fd*. On successful completion the service endpoint is activated and changes to state "Idle". The service provider may now begin to enqueue incoming connect indications, or the application may start an active connection establishment. If the service provider, which is accessed through the endpoint identified by *fd*, comprises an application system only, a transport system has to be linked below this application system in order to complete the protocol stack. This first step can be omitted if the service provider's protocol stack is already complete; this means that it comprises a built-in transport system.
+
+**Name:** x\_bind(*fd*, *trans\_name*, *req*, *ret*, *info*, *xerror*)
+
+**Parameters:**
+
+*fd*: Identification of the service endpoint
+
+*trans\_name*: specifies the name of the transport system
+
+*req*: Identification of the name of the protocol-specific service primitive
+
+- *own\_address*: contains the own protocol address
+- *qlen*: the number of incoming calls that may be queued by the service provider for this endpoint
+
+*ret*: Identification of the name of the protocol-specific service primitive
+
+- *own\_address*: contains the protocol address which has been bound to the service endpoint
+- *qlen*: negotiation of the number of incoming calls that may be queued by the service provider for this endpoint
+
+*info*: contains the characteristics of the service provider
+
+*xerror*: Error codes
+
+Return value: indicates successful completion or failure
+
+##### 9.3.1.2 x\_close
+
+Description: Informs the service provider that the user is finished with the service endpoint identified by *fd*, and frees any local XAPI library resources associated with the endpoint. In addition, *x\_close()* closes the file descriptor associated with the service endpoint. The function *x\_close()* should be called from the "Unbnd" state. However, this function does not check state information, so it may be called from any state to close a service endpoint. If this occurs, the local library resources associated with the endpoint will be freed automatically, and the operating system specific call for closing files, e.g. *close()*, will be issued for that file descriptor. This will break any connection that may be associated with the service endpoint. An *x\_close()* issued on a service endpoint engaged in data transfer may cause data previously sent, or data not yet received, to be lost. It is not recommended to simply close a file descriptor identifying an XAPI service endpoint with the operating system-specific function call. Instead, the *x\_close()* function should always be used to close a service endpoint. This enables the XAPI library to free the local resources allocated for this endpoint.
+
+Name: x\_close(*fd*, *xerror*)
+
+Parameters:
+
+*fd*: Identification of the service endpoint
+
+*xerror*: Error codes
+
+Return value: indicates successful completion or failure
+
+##### 9.3.1.3 x\_open
+
+Description: This function must be called as the first step to create a local service endpoint. A service provider is to be accessed through the newly created endpoint.
+
+Name: x\_open (*prov\_name*, *mode*, *info*, *xerror*)
+
+Parameters:
+
+*prov\_name*: Name of the service provider
+
+*mode*: specifies the initial execution mode for the service endpoint
+
+*info*: contains the characteristics of the service provider to be accessed
+
+*xerror*: Error codes
+
+Return value: generates a valid file descriptor or indicates failure
+
+##### 9.3.1.4 x\_rcvend
+
+Description: Indicates that the service provider is ready to establish a new connection on this endpoint. If charging units are supported, they will be returned.
+
+Name: x\_open(*fd*, *end*, *xerror*)
+
+Parameters:
+
+*fd*: Identification of the service endpoint
+
+*end*: contains parameters
+
+*xerror*: Error codes
+
+Return value: indicates successful completion or failure
+
+##### 9.3.1.5 x\_unbind
+
+Description: Deactivates the service endpoint identified by *fd* which was previously activated by an *x\_bind()* call. On completion of *x\_unbind()*, no further data or events destined for this service endpoint will be accepted by the service provider. If the service provider accessed through the endpoint has a dynamically linked transport system below its application system, the transport system is unlinked from the application system. Built-in transport systems are not affected by *x\_unbind()*. In both cases, the protocol address that has been associated with the endpoint on *x\_bind()* is removed from the service endpoint. If this was a passive endpoint (one with a value of *qlen* greater than zero) the protocol address is now free again and may be used to activate another passive endpoint. The deactivated service endpoint can be reactivated by a subsequent call to *x\_bind()*.
+
+Name: x\_unbind(*fd*, *xerror*)
+
+Parameters:
+
+*fd*: Identification of the service endpoint
+
+*xerror*: Error codes
+
+Return value: indicates successful completion or failure
+
+#### 9.3.2 Utility functions
+
+#### 9.3.2.1 x\_b2c
+
+Description: Selects a value of type character string out of a buffer.
+
+Use this function to read options, service primitive parameters, and address buffers.
+
+Name: x\_b2c(*nb*, *index*, *len*, *name*, *status*, *xerror*)
+
+Parameters:
+
+*nb*: identifies a buffer
+
+*index*: next entry in the chosen buffer
+
+*len*: length of the entry value
+
+*name*: name of the entry
+
+*status*: indicates success or failure of an option negotiation; unused for address and parameter buffers
+
+*xerror*: Error codes
+
+Return value: a value of type character string or indication of failure
+
+#### 9.3.2.2 x\_b2l
+
+Description: Selects a value of type long out of a buffer.
+
+Use this function to read option, service primitive parameter, and address buffers.
+
+Name: x\_b2l(*nb*, *index*, *len*, *name*, *status*, *xerror*)
+
+Parameters:
+
+*nb*: identifies a buffer
+
+*index*: next entry in the chosen buffer
+
+*len*: length of the entry value
+
+*name*: name of the entry
+
+*status*: indicates success or failure of an option negotiation; unused for address and parameter buffers
+
+*xerror*: Error codes
+
+Return value: a value of type long or indication of failure
+
+#### 9.3.2.3 x\_c2b
+
+Description: Writes a value of type character string into a buffer.  
+Use this function to write option, service primitive parameter, and address buffers.
+
+Name: x\_c2b(nb, index, len, name, value, xerror)
+
+Parameters:
+
+*nb*: identifies a buffer
+
+*index*: next entry in the chosen buffer
+
+*len*: length of the entry value
+
+*name*: name of the entry
+
+*value*: value of the entry
+
+*xerror*: Error codes
+
+Return value: indicates successful completion or failure
+
+#### 9.3.2.4 x\_chexmod
+
+Description: Changes the execution mode for the service endpoint identified by *fd*. The *mode* argument specifies the new execution mode:
+
+SYNCHRON to switch to synchronous execution mode
+
+ASYNCHRON to switch to asynchronous execution mode
+
+The initial execution mode for a service endpoint is assigned when the endpoint is created with the *x\_open()* function. The user may change the execution mode at any time.
+
+Depending on the operating system, maybe not all execution modes are supported for all service providers.
+
+Name: x\_chexmod(fd, mode, xerror)
+
+Parameters:
+
+*fd*: identifies the service endpoint
+
+*mode*: specifies the new execution mode
+
+*xerror*: Error codes
+
+Return value: indicates successful completion or failure
+
+#### 9.3.2.5 x\_error
+
+Description: Writes a message to the standard error output.
+
+The whole message is written as follows: First, the string pointed to by *errmsg* followed by a colon and a space is written. Then, the error message string corresponding to the error indicated by *xerror* is written, followed by a newline character.
+
+The messages are the same as returned by *x\_strerror()*. If an error code is unknown, *x\_error()* writes the string
+
+"<error>: error unknown"
+
+where <error> is the (decimal) error number supplied as value of *xerror*.
+
+Name: *x\_error(errmsg, xerror)*
+
+Parameters:
+
+*errmsg*: user-supplied error message
+
+*xerror*: error code returned by an XAPI function call
+
+Return value: indicates completion
+
+##### 9.3.2.6 **x\_getinfo**
+
+Description: Returns by *info* the current characteristics of the underlying service provider and/or connection associated with the service endpoint identified by *fd*. This is the same information as returned by *x\_open()* and *x\_bind()*, although not necessarily precisely the same values as some of them might have been changed in a peer-to-peer negotiation during connection establishment. The function *x\_getinfo()* enables a service user to access this information during any phase of communication.
+
+Name: *x\_getinfo(fd, info, xerror)*
+
+Parameters:
+
+*fd*: identifies the service endpoint
+
+*info*: shows the current characteristics of the underlying service provider
+
+*xerror*: Error codes
+
+Return value: indicates successful completion or failure
+
+##### 9.3.2.7 **x\_look**
+
+Description: Returns the current event on the service endpoint identified by *fd*. The user should then call *x\_look()* to see which event occurred. The function *x\_look()* acts independent of the current execution mode.
+
+The function may also be used to poll a service endpoint periodically for asynchronous events.
+
+Name: *x\_look(fd, xerror)*
+
+Parameters:
+
+*fd*: identifies the service endpoint
+
+*xerror*: Error codes
+
+Return value: indicates the current event or failure
+
+##### 9.3.2.8 **x\_l2b**
+
+Description: Writes a value of type long into a buffer.
+
+Use this function to write options, service primitive parameters, and address buffers.
+
+Name: *x\_l2b(nb, index, len, name, value, xerror)*
+
+Parameters:
+
+*nb*: identifies a buffer  
+*index*: next entry in the chosen buffer  
+*len*: length of the entry value  
+*name*: name of the entry  
+*value*: value of the entry  
+*xerror*: Error codes
+
+Return value: indicates successful completion or failure
+
+##### 9.3.2.9 x\_optmgt
+
+Description: Enables a user to retrieve, verify or negotiate protocol options with the service provider or the XAPI library. It can be used to negotiate non-connection-related options or preset connection-related options for future connections. The function can process and return all options related to the specified service endpoint. The function may be called in all states of the endpoint except X\_UNINIT.
+
+A call of *x\_optmgt()* is an atomic operation, i.e. it always acts independent of the current execution mode and the caller is blocked until the return of *x\_optmgt()*.
+
+The protocol module which is the object of the *x\_optmgt()* call is denoted by the *level* parameter. To handle XAPI-level options, XAPI\_LEVEL has to be specified as *level*.
+
+The parameters *req* and *ret* both reference an option management structure which contains the members *options* and *flags*.
+
+On input, the *options* buffer of *req* contains the requested options and the *flags* specify the action that shall be taken with these options. On return, the result of the option management call is available in *ret*. What is returned in the *options* buffer of *ret* and in *flags* depends on the action which has been specified in *req*. The *flags* field of *req* must specify one of the following actions: NEGOTIATE, CHECK, DEFAULT, CURRENT. The *status* field in the header of each returned option is set to indicate the result of the action. The value is SUCCESS, PARTSUCCESS, READONLY, NOTSUPPORT, or FAILURE. The overall result of the action is returned in *ret->flags*. It contains the worst single result, whereby the rating is done according to the order (from worst to best) FAILURE, NOTSUPPORT, READONLY, PARTSUCCESS, SUCCESS.
+
+Name: x\_optmgt(fd, level, req, ret, xerror)
+
+Parameters:
+
+*fd*: identifies the service endpoint  
+*level*: a protocol module identifier that selects the target protocol module  
+*req*: contains the option specifications which shall be passed to the protocol module and the action to take with the options:  
+– *options*  
+– *flags*  
+*ret*: contains the result of the option management call:  
+– *options*  
+– *flags*  
+*xerror*: Error codes
+
+Return value: indicates successful completion or failure
+
+##### 9.3.2.10 `x_rcverror`
+
+Description: Is used to retrieve an error indication that has been generated by the service provider. It is the consuming function for the XAPI event ERROR and must be issued, if this event occurred at a service endpoint or a previous function failed with ER\_ERROR.
+
+The function behaves independent of the execution mode.
+
+Name: `x_rcverror(fd, err, xerror)`
+
+Parameters:
+
+*fd*: identifies the service endpoint
+
+*err*: gives some basic information about the location where the error has been detected, and the reason for failure:
+
+- *level*: identifies the protocol module which generated the error indication
+- *service*: specifies the service that caused the error indication
+- *cause*: cause code
+- *diagnostic*: conditional, some additional information about the error
+
+*xerror*: Error codes
+
+Return value: indicates successful completion or failure
+
+##### 9.3.2.11 `x_strerror`
+
+Description: Maps the XAPI error number *errnum* to an error message string and returns the string. If an error code is unknown, `x_strerror()` returns the string
+
+`"<error>: error unknown"`
+
+where <error> is the (decimal) error number supplied as input.
+
+Name: `x_strerror(errnum)`
+
+Parameters:
+
+*errnum*: specifies an XAPI-level error code
+
+Return value: error message string
+
+##### 9.3.2.12 `x_sync`
+
+Description: Synchronizes the data structures managed by the XAPI library with the information from the underlying service provider. In doing so it can convert an uninitialized file descriptor (not obtained from an `x_open()` call) to an initialized service endpoint by updating and allocating the necessary library data structures. Usually they are allocated and initialized by `x_open()`.
+
+The function `x_sync()` also allows two cooperating processes which both access the same service endpoint, to synchronize their interaction with the service provider. It is important to remember that the service provider treats all users of a service endpoint as a single user. If multiple processes are using the same endpoint, they should coordinate their activities so as not to violate the state of the service endpoint. The function `x_sync()` returns the current state of the service endpoint to the caller, thereby enabling the user to verify the state before taking further action. This coordination is only valid among cooperating processes; it is possible that a process or an incoming event could change the endpoint's state **after** an `x_sync()` is issued.
+
+Name: `x_sync(fd, xerror)`
+
+Parameters:
+
+*fd*: identifies the service endpoint
+
+*xerror*: Error codes
+
+Return value: indicates the current state or failure
+
+# ANNEX A
+
+## Interface definition language description
+
+This annex provides additional information concerning the XAPI functions (see clause 9). It contains an IDL description of the XAPI.
+
+IDL defines the types of objects according to the operations that may be performed on them and the parameters to those operations.
+
+module x
+
+{
+
+```
+/* */
+/* Asynchronous events returned by x_look() */
+/* */
+```
+
+```
+const short NOEVENT      = 0x0000;    /* no event present at the endpoint      */
+const short ERROR        = 0x0001;    /* error condition detected by the       */
+                                      /* service provider                      */
+const short CONIND       = 0x0002;    /* connection indication received        */
+const short CONCONF      = 0x0004;    /* connect confirmation received         */
+const short DATA         = 0x0008;    /* normal data received                  */
+const short EXDATA       = 0x0010;    /* expedited data received               */
+const short SP           = 0x0020;    /* service primitive received            */
+const short DISCONNECT   = 0x0040;    /* disconnect received                   */
+const short RELIND= 0x0080;           /* orderly release indication received   */
+const short RELCONF      = 0x0100;    /* orderly release confirmation received */
+const short GODATA       = 0x0200;    /* normal data may be sent again         */
+const short GOEXDATA     = 0x0400;    /* expedited data may be sent again      */
+const short END          = 0x0800;    /* end indication received               */
+const short EVENTS       = 0x0FFF;    /* event mask                            */
+```
+
+```
+/* */
+/* Bit-Flag Definitions */
+/* The bit-masks are used in the flags field of call_struct, conind_struct, */
+/* optmgmt_struct, release_struct and in the flags argument of x_snddata(), */
+/* x_rcvdata(), x_snddis(), x_rcvdis, x_sndsp(), x_rcvsp()                  */
+/* */
+```
+
+```
+const unsigned long NOFLAG = 0x0000;  /* no flag is set                        */
+const unsigned long MORE   = 0x0001;  /* more data                             */
+                                      /* used in struct x_call, x_conind,      */
+                                      /* x_snddata(), x_rcvdata()              */
+```
+
+```
+
+const unsigned long EXPEDITED = 0x0002; /* expedited data */
+/* used in x_snddata(), x_rcvdata() */
+const unsigned long NEGATIVE = 0x0004; /* negative confirmation/response */
+/* used in struct x_call */
+
+/* ----- */
+/* Option Management Bit-Flag Definitions */
+/* The bit-masks are used in the flags field of optmgmt_struct. */
+/* Input bits are marked with (i) and output bits with (o). */
+/* ----- */
+
+const unsigned long NEGOTIATE = 0x00000100; /* (i) negotiate (set) options */
+const unsigned long CHECK = 0x00000200; /* (i) check options */
+const unsigned long DEFAULT = 0x00000400; /* (i) get default values of options */
+const unsigned long CURRENT = 0x00000800; /* (i) get current values of options */
+const unsigned long SUCCESS = 0x00001000; /* (o) successful option negotiation */
+const unsigned long PARTSUCCESS = 0x00002000; /* (o) partially successful option negotiation */
+const unsigned long READONLY = 0x00004000; /* (o) option is readonly */
+const unsigned long NOTSUPPORT = 0x00008000; /* (o) option is not supported */
+const unsigned long FAILURE = 0x00010000; /* (o) failure in option negotiation */
+
+/* ----- */
+/* Execution modes */
+/* Used in x_open() and x_chexmod() calls */
+/* ----- */
+
+const short SYNCHRON = 1; /* synchronous execution mode */
+const short ASYNCHRON = 2; /* asynchronous execution mode */
+
+/* ----- */
+/* Protocol Module Identifiers */
+/* ----- */
+
+const unsigned long NO_MODULE = 0x7FFFFFFF; /* no protocol module present */
+const unsigned long XAPI_LEVEL = 20; /* denotes the XAPI library; to access XAPI-level options with x_optmgmt() */
+const unsigned long TOP_LEVEL = 2; /* Topmost protocol module; the special value is defined in the provider info */
+
+```
+
+```
+
+/* ----- */
+/* General purpose service parameter values                                     */
+/* ----- */
+
+const unsigned long PV_TRUE      = 1;      /* parameter value boolean true      */
+const unsigned long PV_FALSE    = 0;      /* parameter value boolean false      */
+
+/* ----- */
+/* Names of address components                                                 */
+/* ----- */
+
+const unsigned long A_OUTBAND_ADR = 1;      /* outband address                    */
+const unsigned long A_INBAND_ADR  = 3;      /* inband address                     */
+const unsigned long A_INB_SUBADR  = 4;      /* inband subaddress                  */
+const unsigned long A_SERVICE     = 5;      /* service indicator                  */
+const unsigned long A_P_SELECTOR  = 1000;   /* presentation selector              */
+const unsigned long A_S_SELECTOR  = 1001;   /* session selector                   */
+const unsigned long A_T_SELECTOR  = 1002;   /* transport selector                 */
+
+/* ----- */
+/* Constants defining the maximum length for address components                */
+/* ----- */
+
+const unsigned long C_MAX_IBADR    = 32;    /* max. length of inband address      */
+const unsigned long C_MAX_IBSADR   = 32;    /* max. length of inband subaddress   */
+const unsigned long C_MAX_OBADR    = 32;    /* max. length of outband address     */
+const unsigned long C_MAX_SERVICE  = 6;     /* max. length of service indicator    */
+const unsigned long C_MAX_PSEL     = 32;    /* max. length of presentation selector */
+const unsigned long C_MAX_SSEL     = 16;    /* max. length of session selector     */
+const unsigned long C_MAX_TSEL     = 32;    /* max. length of transport selector   */
+
+/* ----- */
+/* Constants defining the maximum length for session components                */
+/* ----- */
+
+const unsigned long C_MAX_REF      = 64;    /* max. length of service user reference */
+/*                                     /* and common reference                 */
+const unsigned long C_MAX_ARI      = 4;     /* max. length of additional information */
+
+/* ----- */
+/* XAPI-level Options                                                         */
+/* ----- */
+
+const unsigned long O_TRACE        = 1;     /* XAPI trace option                   */
+
+```
+
+```
+
+/* ----- */
+/* Defined values for option O_TRACE */
+/* ----- */
+
+const unsigned long OV_NOTRACE    = 0x00; /* switches all traces off (default) */
+const unsigned long OV_BUFFTRACE = 0x01; /* enables buffer trace for          */
+/* received and sent PDUs;          */
+/* all trace messages are disabled */
+const unsigned long OV_ERR       = 0x10; /* enables error trace messages      */
+/* and disables buffer traces       */
+const unsigned long OV_ERR_BUF   = 0x11; /* enables error trace messages      */
+/* plus buffer traces               */
+const unsigned long OV_WRN       = 0x30; /* enables error and warning         */
+/* trace messages;                 */
+/* buffer traces are disabled      */
+const unsigned long OV_WRN_BUF   = 0x31; /* enables error and warning trace   */
+/* messages plus buffer traces     */
+const unsigned long OV_INF       = 0x70; /* enables error, warning, and       */
+/* info trace messages;           */
+/* buffer traces are disabled      */
+const unsigned long OV_INF_BUF   = 0x71; /* enables error, warning, and       */
+/* info trace messages plus       */
+/* buffer traces                  */
+
+/* ----- */
+/* General Definitions */
+/* ----- */
+
+const unsigned long INFINITE      = ~0; /* 0xFFFFFFFF;                      */
+/* BBB: value needs to be checked in */
+/* language mappings infinite size   */
+/* suitable for unsigned long        */
+const unsigned long UNSPECIFIED  = ~1; /* 0xFFFFFFF;                       */
+/* BBB: value needs to be checked in */
+/* language mappings unspecified size */
+/* suitable for unsigned long        */
+
+/* ----- */
+/* Service Provider Capabilities */
+/* ----- */
+
+const unsigned long SPC_COS       = 0x00000001; /* connection-mode service */
+const unsigned long SPC_CLS       = 0x00000002; /* connectionless service  */
+const unsigned long SPC_ORD_REL   = 0x00000004; /* orderly release         */
+const unsigned long SPC_0DATA     = 0x00000008; /* zero-length data units  */
+const unsigned long SPC_DATA      = 0x00000010; /* (normal) data           */
+const unsigned long SPC_EXPDATA   = 0x00000020; /* expedited data          */
+const unsigned long SPC_NEGCONRSP = 0x00000040; /* negative connect response */
+const unsigned long SPC_NEGCONCNF = 0x00000080; /* negative connect confirm. */
+const unsigned long SPC_MORECONRQ = 0x00000100; /* MORE in x_conreq()      */
+
+```
+
+```
+
+const unsigned long SPC_MORECONCF = 0x00000200; /* MORE in x_conconf() */
+const unsigned long SPC_MORECONIN = 0x00000400; /* MORE in x_conind() */
+const unsigned long SPC_MORECONRP = 0x00000800; /* MORE in x_conrsp() */
+const unsigned long SPC_MORERELRQ = 0x00001000; /* MORE in x_relreq() */
+const unsigned long SPC_MORERELCF = 0x00002000; /* MORE in x_relconf() */
+const unsigned long SPC_MORERELIN = 0x00004000; /* MORE in x_relind() */
+const unsigned long SPC_MORERELRP = 0x00008000; /* MORE in x_relrsp() */
+const unsigned long SPC_SP        = 0x00010000; /* send service primitive */
+const unsigned long SPC_MORESNDSP = 0x00020000; /* MORE in x_sndsp() */
+const unsigned long SPC_MORERCVSP = 0x00030000; /* MORE in x_rcvsp() */
+const unsigned long SPC_MORESNDDIS= 0x00040000; /* MORE in x_snddis() */
+const unsigned long SPC_MORERCVDIS= 0x00050000; /* MORE in x_rcvdis() */
+const unsigned long SPC_MASK      = 0x000FFFFF; /* all defined capabilities */
+
+/*   */
+/* Disconnect Origination */
+/*   */
+
+const unsigned long PROVIDER_ABORT = 0x00000001; /* disconnect generated */
+                                                 /* by the service provider */
+const unsigned long ABORT          = 0x00000002; /* disconnect generated */
+                                                 /* by the user */
+
+/*   */
+/* Services indicated in error_struct */
+/*   */
+
+const unsigned long CONNECT_REQ    = 0x01;  /* connect request; x_conreq() */
+const unsigned long CONNECT_RES    = 0x02;  /* connect response; x_conrsp() */
+const unsigned long DATA_REQ       = 0x03;  /* data request; x_snddata() */
+const unsigned long EXPDATA_REQ    = 0x04;  /* expedited data request; */
+                                            /* x_snddata() */
+const unsigned long DISC_REQ       = 0x05;  /* disconnect request; x_snddis() */
+const unsigned long RELEASE_REQ    = 0x06;  /* release request; x_relreq() */
+const unsigned long RELEASE_RES    = 0x07;  /* release response; x_relrsp() */
+const unsigned long SND_SP         = 0x08;  /* send service primitive; */
+                                            /* x_sndsp() */
+
+/*   */
+/* Cause Codes indicated in error_struct */
+/*   */
+
+const unsigned long CC_BADEVENT    = 0x01;  /* requested service unknown */
+                                            /* to the service provider */
+const unsigned long CC_UNEXPECT    = 0x02;  /* requested service not allowed */
+                                            /* in current state of */
+                                            /* service provider */
+const unsigned long CC_NOTSUPPORT  = 0x03;  /* requested service not */
+                                            /* supported by the service */
+                                            /* provider */
+
+```
+
+```
+
+const unsigned long CC_BADVALUE      = 0x04; /* illegal value specified for a */
+                                             /* a service parameter           */
+const unsigned long CC_MANDMISS      = 0x05; /* mandatory service parameter   */
+                                             /* missing                       */
+const unsigned long CC_OTHER         = 0x06; /* any other error               */
+const unsigned long CC_NOSPACE       = 0x07; /* no space                      */
+const unsigned long CC_SPNAME        = 0x08; /* SP_name incorrect             */
+const unsigned long CC_ADDCOMP       = 0x09; /* additional component          */
+                                             /* incorrect                     */
+const unsigned long CC_BADLENGTH     = 0x0A; /* string or value too long      */
+const unsigned long CC_SEQ           = 0x0B; /* SEQ incorrect                 */
+
+```
+
+```
+
+/*  */
+/* Service parameters for x_rcvend() */
+/*  */
+
+```
+
+```
+
+const unsigned long P_CONN_TIME      = 0x01; /* Connection time    */
+const unsigned long P_DISC_TIME      = 0x02; /* Disconnection time */
+const unsigned long P_CHARGE         = 0x03; /* Charging units     */
+const unsigned long P_DISC_REASON    = 0x04; /* Disconnect reason  */
+
+```
+
+```
+
+/*  */
+/* Possible states of a service endpoint */
+/*  */
+
+```
+
+```
+
+const short UNINIT      = 0; /* uninitialized                */
+const short UNBND       = 1; /* unbound                      */
+const short IDLE        = 2; /* idle                         */
+const short OUTCON      = 3; /* outgoing connection pending   */
+const short INCON       = 4; /* incoming connection pending   */
+const short CONNECT     = 5; /* connected / data transfer    */
+const short OUTREL      = 6; /* outgoing release pending     */
+const short INREL       = 7; /* incoming release pending     */
+const short WAITEND     = 8; /* waiting for end indication   */
+
+```
+
+```
+
+typedef sequence < octet > octet_sequence;
+
+```
+
+```
+
+/*  */
+/* provinfo_struct */
+/* Service provider information structure; returned by x_open(), */
+/* x_bind() and x_getinfo(). */
+/*  */
+
+```
+
+```
+
+typedef unsigned long ten_unsigned_longs[10];
+
+```
+
+```
+
+struct provinfo_struct
+{
+    /* Protocol module identifiers of the modules in the service
+     * provider's protocol stack. If no protocol module is present on
+     * a certain layer in the protocol stack, the corresponding ln_pmid
+
+```
+
+```
+
+* field(s) is(are) set to NO_MODULE
+*/
+ten_unsigned longs   17_pmid;           /* layer 7 protocol module IDs      */
+unsigned long         16_pmid;           /* layer 6 protocol module ID       */
+unsigned long         15_pmid;           /* layer 5 protocol module ID       */
+unsigned long         14_pmid;           /* layer 4 protocol module ID       */
+unsigned long         13_pmid;           /* layer 3 protocol module ID       */
+unsigned long         12_pmid;           /* layer 2 protocol module ID       */
+unsigned long         11_pmid;           /* layer 1 protocol module ID       */
+unsigned long         Monitor_pmid;      /* Monitor protocol module ID       */
+
+unsigned long         max_qlen;           /* max. supported value for qlen    */
+
+/* Buffer sizes recommended for the service provider. Output buffers
+ * with these sizes will be sufficient in all cases.
+ */
+unsigned long         addr_buff_size;     /* address buffer size               */
+unsigned long         optn_buff_size;     /* option buffer size                */
+unsigned long         parm_buff_size;     /* SP parameter buffer size         */
+unsigned long         data_frgmt_size;    /* maximum data fragment size       */
+unsigned long         end_buff_size;      /* end indication buffer size       */
+
+/* Maximum data unit sizes supported by the service provider.
+ */
+unsigned long         max_sdu_size;        /* max. size of a (normal)          */
+                                           /* service data unit                 */
+unsigned long         max_esdu_size;       /* max. size of an expedited        */
+                                           /* service data unit                 */
+unsigned long         max_conn_user_data;  /* max. user data size for          */
+                                           /* connection primitives             */
+unsigned long         max_disc_user_data;  /* max. user data size for          */
+                                           /* disconnect primitives             */
+unsigned long         max_rels_user_data;  /* max. user data size for          */
+                                           /* release primitives                */
+
+/* The capabilities of the service provider are represented as
+ * bit-field. A capability is supported by the application system,
+ * if the corresponding bit is set in prov_capabilities; it is not
+ * supported, if the bit is cleared.
+ */
+unsigned long         prov_capabilities;    /* service provider capabilities    */
+};
+
+```
+
+```
+
+/* ----- */
+/* bind_struct                                     */
+/* argument structure for x_bind()                   */
+/* ----- */
+
+```
+
+```
+
+struct bind_struct
+{
+    octet_sequenceown_address;           /* own NSAP address          */
+    unsigned long qlen;                   /* number of incoming calls  */
+                                         /* to be queued for the endpoint */
+};
+
+```
+
+```
+
+/* ----- */
+/* call_struct                                     */
+/* argument structure for connection establishment */
+/* ----- */
+
+```
+
+```
+
+struct call_struct
+{
+    octet_sequenceaddress;               /* address buffer            */
+    octet_sequenceparameter;             /* SP parameter buffer       */
+    octet_sequenceuser_data;             /* user data buffer          */
+    unsigned long sequence_nr;            /* sequence number           */
+    unsigned long flags;                  /* flags; MORE / NEGATIVE    */
+};
+
+```
+
+```
+
+/* ----- */
+/* conind_struct                                    */
+/* argument structure for connect indication        */
+/* ----- */
+
+```
+
+```
+
+struct conind_struct
+{
+    octet_sequencecalled_addr;           /* address buffer called address */
+    octet_sequencecalling_addr;          /* address buffer calling address */
+    octet_sequenceparameter;             /* SP parameter buffer          */
+    octet_sequenceuser_data;             /* user data buffer             */
+    unsigned long sequence_nr;            /* sequence number              */
+    unsigned long flags;                  /* flags; MORE                  */
+};
+
+```
+
+```
+
+/* ----- */
+/* data_struct                                     */
+/* argument structure for x_snddata() and x_rcvdata() */
+/* ----- */
+
+```
+
+```
+
+struct data_struct
+{
+    octet_sequenceparameter;          /* SP parameter buffer      */
+    octet_sequencedata;               /* data buffer              */
+};
+
+```
+
+```
+
+/* ----- */
+/* discon_struct                                   */
+/* argument structure for x_snddis() and x_rcvdis() */
+/* ----- */
+
+```
+
+```
+
+struct discon_struct
+{
+    octet_sequenceuser_data;          /* user data buffer         */
+    octet_sequenceparameter;          /* SP parameter buffer      */
+    unsigned long origination;         /* origination of disconnect; */
+                                        /* used on output only      */
+    unsigned long sequence_nr;         /* sequence number; used only */
+                                        /* when an incoming call is rejected */
+};
+
+```
+
+```
+
+/* ----- */
+/* error_struct                                     */
+/* argument structure for x_rcverrors()             */
+/* ----- */
+
+```
+
+```
+
+struct error_struct
+{
+    unsigned long level;               /* protocol module ID of the originator module */
+    unsigned long service;             /* requested service that caused the error      */
+    unsigned long cause;               /* cause code specifying the reason of failure  */
+    unsigned long diagnostic;          /* additional protocol-specific diagnostic information */
+};
+
+```
+
+```
+
+/* ----- */
+/* end_struct                                       */
+/* argument structure for x_rcvend()               */
+/* ----- */
+
+```
+
+```
+
+struct end_struct
+{
+    octet_sequence parameter;          /* SP parameter buffer      */
+};
+
+```
+
+```
+
+/* ----- */
+/* optmgmt_struct                                */
+/* argument structure for x_optmgmt()             */
+/* ----- */
+
+```
+
+```
+
+struct optmgmt_struct
+{
+    octet_sequenceoptions;      /* option definitions          */
+    unsigned long flags;        /* what to do with options    */
+};
+
+```
+
+```
+
+/* ----- */
+/* release_struct                                */
+/* argument structure for orderly release         */
+/* ----- */
+
+```
+
+```
+
+struct release_struct
+{
+    octet_sequenceparameter;    /* SP parameter buffer        */
+    octet_sequenceuser_data;    /* user data buffer           */
+    unsigned long flags;        /* flags; MORE                */
+};
+
+```
+
+```
+
+/* ----- */
+/* sp_struct                                    */
+/* argument structure for x_sndsp() and x_rcvsp() */
+/* ----- */
+
+```
+
+```
+
+struct sp_struct
+{
+    octet_sequenceparameter;    /* SP parameter buffer        */
+    octet_sequencedata;         /* data buffer                 */
+};
+
+```
+
+```
+
+exception XERROR
+{
+    short error_code;
+};
+
+```
+
+```
+
+interface ep
+{
+    short bind(
+        in      short fd,
+        in      string trans_name,
+        in      bind_struct req,
+        out     bind_struct ret,
+        out     provinfo_struct info)
+        raises ( XERROR );
+};
+
+```
+
+```
+
+short chexmod(      in      short fd,
+                  in      short mode)
+    raises ( XERROR );
+
+short close(        in      short fd
+                  )
+    raises ( XERROR );
+
+short conconf(      in      short fd,
+                  out      call_struct call)
+    raises ( XERROR );
+
+short conind(       in      short fd,
+                  out      conind_struct call)
+    raises ( XERROR );
+
+short conreq(       in      short fd,
+                  in      call_struct sndcall)
+    raises ( XERROR );
+
+short conrsp(       in      short fd,
+                  in      short resfd,
+                  in      call_struct call)
+    raises ( XERROR );
+
+short getinfo(      in      short fd,
+                  out      provinfo_struct info)
+    raises ( XERROR );
+
+short look(         in      short fd
+                  )
+    raises ( XERROR );
+
+    short optmgmt(   in      short fd,
+                  in      unsigned long level,
+                  in      optmgmt_struct req,
+                  out     optmgmt_struct ret)
+        raises ( XERROR );
+
+short rcvdata(      in      short fd,
+                  out      data_struct data,
+                  out      unsigned long flags)
+    raises ( XERROR );
+
+short rcvdis(       in      short fd,
+                  out      discon_struct disc,
+                  out      unsigned long flags)
+    raises ( XERROR );
+
+```
+
+```
+
+short rcvend(          in      short fd,
+                     out      end_struct end)
+                     raises ( XERROR );
+
+short rcverror(        in      short fd,
+                     out      error_struct err)
+                     raises ( XERROR );
+
+short rcvinfo(         in      short fd,
+                     out      unsigned long level,
+                     out      unsigned long info,
+                     out      sp_struct par,
+                     out      unsigned long flags)
+                     raises ( XERROR );
+
+short rcvsp(           in      short fd,
+                     out      unsigned long level,
+                     out      unsigned long spname,
+                     out      sp_struct sp,
+                     out      unsigned long flags)
+                     raises ( XERROR );
+
+short relconf(         in      short fd,
+                     out      release_struct rel)
+                     raises ( XERROR );
+
+short relind(          in      short fd,
+                     out      release_struct rel)
+                     raises ( XERROR );
+
+short relreq(          in      short fd,
+                     in      release_struct rel)
+                     raises ( XERROR );
+
+short relrsp(          in      short fd,
+                     in      release_struct rel)
+                     raises ( XERROR );
+
+short snddata(         in      short fd,
+                     in      data_struct data,
+                     in      unsigned long flags)
+                     raises ( XERROR );
+
+short snddis(          in      short fd,
+                     in      discon_struct disc,
+                     in      unsigned long flags)
+                     raises ( XERROR );
+
+```
+
+```
+
+short sndinfo(      in      short fd,
+                   in      unsigned long level,
+                   in      unsigned long info,
+                   in      sp_struct par,
+                   in      unsigned long flags)
+    raises ( XERROR );
+
+short sndsp(        in      short fd,
+                   in      unsigned long level,
+                   in      unsigned long spname,
+                   in      sp_struct sp,
+                   in      unsigned long flags)
+    raises ( XERROR );
+
+short sync(         in      short fd
+                   )
+    raises ( XERROR );
+
+short unbind(       in      short fd
+                   )
+    raises ( XERROR );
+
+};
+
+interface api
+{
+    string b2c (      in      octet_sequence nb,
+                    inout    unsigned long index,
+                    out      unsigned long len,
+                    out      unsigned long name,
+                    out      unsigned long status)
+        raises ( XERROR );
+
+    long b2l(         in      octet_sequence nb,
+                    inout    unsigned long index,
+                    out      unsigned long len,
+                    out      unsigned long name,
+                    out      unsigned long status)
+        raises ( XERROR );
+
+    short c2b(        in      octet_sequence nb,
+                    inout    unsigned long index,
+                    in      unsigned long len,
+                    in      unsigned long name,
+                    in      string value)
+        raises ( XERROR );
+
+    short error(      in      string errmsg,
+                    in      short xerror);
+
+```
+
+```
+
+short l2b(          in      octet_sequence nb,
+                  inout    unsigned long index,
+                  in      unsigned long len,
+                  in      unsigned long name,
+                  in      long value)
+    raises ( XERROR );
+
+short open(         in      string prov_name,
+                  in      short mode,
+                  out     provinfo_struct info)
+    raises ( XERROR );
+
+string strerror(    in      short ernum);
+};
+
+};
+
+```
+
+# ANNEX B
+
+## Error codes
+
+An application program using the XAPI has to deal with errors on three levels. The first is the **XAPI error level**. Each function returns `-1` to indicate failure and `0` (zero) to indicate success. In case of failure, the integer output parameter *xerror* is set to one of the error codes defined below. The error code provides some more detailed information about the reason of failure. In case of success, *xerror* is set to `NOERROR`.
+
+The second level is the **operating system error level**. When an operating system service routine called by the application fails, the error is reported in an operating-system-dependent way. The XAPI functions use operating system calls, too, but these calls are hidden from the application. When an XAPI function fails due to an error in an operating system call, the error code reported by the system is mapped to the corresponding XAPI-level error code, which is returned to the user as described above. In some rare cases, if there is no XAPI error code corresponding to the system error, the XAPI function will return failure and indicate the special XAPI-level error code `ER_SYSERR`. The application may then access and check the operating system error code. For the meaning of the system error codes, refer to the operating system documentation. Note that the system error codes may (will) be different for the various base operating systems. This affects the portability of an application that checks system error codes. The XAPI-level error codes, conversely, are identical for all base operating systems.
+
+Two utility functions can be used to map XAPI-level error codes to short text error messages. Both utilities take the error code as argument; *x\_error* prints the corresponding error message to the standard error output *stderr*, while *x\_strerror* returns the corresponding error message character string. For system level errors there may be similar functions available among the operating system services.
+
+As result of a severe error, a major protocol error, for example, or some local resource problems, a service endpoint and the corresponding file descriptor may be unusable for all XAPI and system calls except *x\_close*. To continue in this case, all users of the *fd* must close it, i.e. call *x\_close*. Then a new service endpoint may be created and initialized to continue with communication.
+
+The third level is the **service provider error level**. A service provider may generate an asynchronous event ERROR whenever the application program shall be informed about an error condition. This could be
+
+- the reception of an incorrect or incomplete service primitive from the local application; or
+- a request that is not allowed in the current protocol-specific state of the service provider.
+
+The reception of an erroneous or out-of-order PDU from the peer entity is not indicated to the local application but handled by the service provider in a protocol-specific way.
+
+The ERROR event is indicated to the application as are all other asynchronous events and has to be received from the service endpoint with the consuming function *x\_rcverror*. On return, this function yields a service-specific error code and possibly further information about the error as output. The concrete error conditions and the corresponding error codes are defined in the service descriptions.
+
+Error codes at the service provider error level are listed in the appropriate providers (see I.1 to I.7). All other error codes that may be returned by the XAPI functions are listed below.
+
+For each error code a short explanation of the possible reason is given. The error codes are sorted in ascending numerical order.
+
+|              |      |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
+|--------------|------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| NOERROR      | 8001 | No error occurred; all in perfect order. This "error code" is returned in <i>xerror</i> if the function successfully completed.                                                                                                                                                                                                                                                                                                                                                      |
+| ER_BADFD     | 8002 | The file descriptor <i>fd</i> passed as argument does not identify a service endpoint. Maybe <i>fd</i> was not obtained as result of an <i>x_open()</i> call.                                                                                                                                                                                                                                                                                                                        |
+| ER_OUTSTATE  | 8003 | The function was issued in the wrong state of the service endpoint.                                                                                                                                                                                                                                                                                                                                                                                                                  |
+| ER_LOOK      | 8004 | An asynchronous event has occurred on this service endpoint and requires immediate attention. Call <i>x_look()</i> , please.                                                                                                                                                                                                                                                                                                                                                         |
+| ER_NODATA    | 8005 | The XAPI consuming function was called in asynchronous mode, but the requested event and no other asynchronous event are currently available at the service endpoint. The function <i>x_rcvdata()</i> , for instance, looks for a DATA resp. EXDATA event; if none is present at the time of calling, this error code is returned in asynchronous mode.                                                                                                                              |
+| ER_BADFLAG   | 8010 | An invalid flag is specified in the <i>flags</i> field. This error is returned if either an unknown flag is specified or the flag is not allowed for this XAPI function. Note that for some flags it depends on the service provider capabilities whether a certain flag may be used with the function or not. Check the <i>prov_capabilities</i> field in the service provider information structure ( <i>provinfo_struct</i> ) which is returned as output of <i>x_getinfo()</i> . |
+| ER_BADNEG    | 8011 | The negative flag is not the same (set or cleared) as in the previous function calls. If multiple calls to <i>x_conrsp()</i> are used to respond to one connect indication, the value of the NEGATIVE flag must be the same in all of these calls.                                                                                                                                                                                                                                   |
+| ER_NOINFOBUF | 8012 | No buffer has been specified to keep the service provider information returned by <i>x_getinfo()</i> .                                                                                                                                                                                                                                                                                                                                                                               |
+| ER_BADNAME   | 8013 | An invalid service provider identifier, or an invalid transport system identifier has been specified.                                                                                                                                                                                                                                                                                                                                                                                |
+
+|              |      |                                                                                                                                                                                                                                                                                                                       |
+|--------------|------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| ER_BADADDR   | 8014 | The specified protocol address is in an incorrect format or contained illegal information.                                                                                                                                                                                                                            |
+| ER_DATASIZE  | 8015 | The amount of user data specified in the call exceeds the limits allowed by the service provider. Check the values specified in the service provider information structure ( <i>provinfo_struct</i> ) which is returned as output of <i>x_getinfo()</i> .                                                             |
+| ER_NOADDR    | 8016 | No own protocol address was specified in the <i>x_bind()</i> call and the service provider could not allocate one.                                                                                                                                                                                                    |
+| ER_ADDRBUSY  | 8017 | There is already a service endpoint with <i>qlen</i> greater than 0 bound to the requested address.                                                                                                                                                                                                                   |
+| ER_ACCESS    | 8018 | The application does not have permission to use the specified address.                                                                                                                                                                                                                                                |
+| ER_NOSYCH    | 8019 | The synchronous execution mode is not supported for this service endpoint.                                                                                                                                                                                                                                            |
+| ER_NOASYCH   | 8020 | The asynchronous execution mode is not supported for this service endpoint.                                                                                                                                                                                                                                           |
+| ER_BADSEQ    | 8021 | An invalid sequence number is specified in an <i>x_conrsp()</i> or <i>x_snddis()</i> call. If multiple calls to <i>x_conrsp()</i> are used to respond to one connect indication, the value of the sequence number must be the same in all of these calls.                                                             |
+| ER_QUEUEFULL | 8022 | The maximum number of outstanding (unresponded) connect indications has been reached. The user has to accept or reject some of these connections before more connect indications can be received with <i>x_conind()</i> .                                                                                             |
+| ER_BADQLEN   | 8023 | At the time of activation, a queue length of zero has been specified for the endpoint referenced by <i>fd</i> . Thus, the endpoint must not be used with <i>x_conind()</i> calls to wait for incoming calls.                                                                                                          |
+| ER_WAITCONF  | 8024 | The function <i>x_conreq()</i> was called in asynchronous mode and successfully initiated the connection establishment procedure, but did not wait for a response from the remote user. Now the local user has to arrange to wait for a connect confirmation, e.g. by calling <i>x_conconf()</i> in synchronous mode. |
+| ER_MOREDATA  | 8025 | The function <i>x_conreq()</i> was called in asynchronous mode with the MORE flag set. To complete the connect request, more user data is required; the local user has to make another <i>x_conreq()</i> call.                                                                                                        |
+| ER_INDOUST   | 8026 | The function <i>x_conrsp()</i> was called with <i>fd</i> equal to <i>resfd</i> , but there are outstanding connection indications on the endpoint. They must be handled, either by rejecting or accepting them on a different endpoint, before the endpoint identified by <i>fd</i> may be used in a connection.      |
+| ER_PROVMISM  | 8027 | The file descriptors <i>fd</i> and <i>resfd</i> specified in the <i>x_conrsp()</i> call do not refer to the same service provider.                                                                                                                                                                                    |
+| ER_RESQLEN   | 8028 | The function <i>x_conrsp()</i> was called with <i>fd</i> not equal to <i>resfd</i> , and the endpoint referenced by <i>resfd</i> has been bound with a <i>qlen</i> that is greater than 0.                                                                                                                            |
+
+|              |      |                                                                                                                                                                                                                                                                                                                                                                           |
+|--------------|------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| ER_RESTRANS  | 8029 | The function <i>x_conrsp()</i> was called with <i>fd</i> not equal to <i>resfd</i> , and the endpoint referenced by <i>resfd</i> has used a different transport system beneath the application system.                                                                                                                                                                    |
+| ER_BADACTN   | 8030 | An invalid action is specified in the <i>flags</i> field as input of <i>x_optmgmt()</i> .                                                                                                                                                                                                                                                                                 |
+| ER_BADOPT    | 8031 | At least one of the options submitted in the <i>x_optmgmt()</i> call specifies an illegal value.                                                                                                                                                                                                                                                                          |
+| ER_BADLEVEL  | 8032 | The value specified as <i>level</i> in an <i>x_optmgmt()</i> or <i>x_sndsp()</i> call does not select any protocol module of the service provider. The identifiers of the protocol modules in the service provider's protocol stack are available in the <i>provinfo_struct</i> which is returned as output of <i>x_open()</i> , <i>x_bind()</i> and <i>x_getinfo()</i> . |
+| ER_NOERRBUFF | 8033 | No <i>error_struct</i> has been specified for the output of <i>x_rcverror()</i> .                                                                                                                                                                                                                                                                                         |
+| ER_NODIS     | 8034 | No disconnect indication currently exists at the specified service endpoint.                                                                                                                                                                                                                                                                                              |
+| ER_FLOW      | 8035 | The sending function is called in asynchronous mode and the flow control mechanism prevents the service provider from accepting the request at this time.                                                                                                                                                                                                                 |
+| ER_NOTSUPP   | 8036 | This function is not supported by the underlying service provider.                                                                                                                                                                                                                                                                                                        |
+| ER_STATECHNG | 8037 | The service endpoint is just undergoing a state change and therefore the function <i>x_sync()</i> could not determine the current state.                                                                                                                                                                                                                                  |
+| ER_SYSERR    | 8041 | An operating system call returned an error during execution of this XAPI function. More information about the failure might be gathered in an operating-system-dependent way.                                                                                                                                                                                             |
+| ER_INTR      | 8042 | The execution of this XAPI function was interrupted by a signal.                                                                                                                                                                                                                                                                                                          |
+| ER_PROTO     | 8043 | This error indicates that a communication problem has been detected between XAPI and the service provider for which there is no other suitable XAPI error code defined.                                                                                                                                                                                                   |
+| ER_NOPARAM   | 8044 | This error code may be returned by the functions <i>x_b2c()</i> and <i>x_b2l()</i> if there is no parameter value found in the buffer.                                                                                                                                                                                                                                    |
+| ER_NOSND     | 8045 | A sending function was called but no further sending is allowed because the connection is destroyed. The events already received from the service provider may be consumed by the corresponding consuming functions (e.g. <i>x_rcvdis()</i> ).                                                                                                                            |
+| ER_ERROR     | 8046 | An error indication has arrived. Call <i>x_error()</i> , please.                                                                                                                                                                                                                                                                                                          |
+| ER_LIMITS    | 8048 | An system limit has been reached. When returned by <i>x_open()</i> , this indicates that the number of open file descriptors in the process or the system has been reached; when returned by a sending function, this indicates that a buffer was too long.                                                                                                               |
+| ER_CONFIG    | 8049 | An error in accessing the service providers or transport systems configuration file has been detected.                                                                                                                                                                                                                                                                    |
+
+|                 |      |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
+|-----------------|------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| ER_BADMODE      | 8050 | An invalid mode has been specified.                                                                                                                                                                                                                                                                                                                                                                                                                                                |
+| ER_TRANSLINK    | 8051 | The function <i>x_bind()</i> failed to link the specified transport system below the service providers application system. This error is returned for two reasons:<br><br>The service provider has a built-in transport system which cannot be replaced by a dynamically linked transport system, or a system error occurred while dynamically linking the transport system. In this case more information about the reason of failure may be available on operating system level. |
+| ER_NOEND        | 8052 | The function <i>x_rcvend()</i> has been called, but no END event is available at the service endpoint.                                                                                                                                                                                                                                                                                                                                                                             |
+| ER_NOERROR      | 8054 | The function <i>x_rcverror()</i> has been called, but no ERROR event is available at the service endpoint.                                                                                                                                                                                                                                                                                                                                                                         |
+| ER_NOCONREQ     | 8055 | The function <i>x_conreq()</i> has been called on a passive service endpoint (i.e. when binding the endpoint with <i>x_bind()</i> the <i>qlen</i> field of <i>bind_struct</i> was greater than zero). Initiating a connection is only allowed on active service endpoints ( <i>qlen</i> = 0).                                                                                                                                                                                      |
+| ER_REM_GENRPC   | 8056 | A general Remote Procedure Call (RPC) failure has occurred in the remote XAPI.                                                                                                                                                                                                                                                                                                                                                                                                     |
+| ER_REM_RPC_PROC | 8057 | The remote procedure call failed.                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
+| ER_REM_CALLBACK | 8058 | The remote XAPI failed to set up the callback channel.                                                                                                                                                                                                                                                                                                                                                                                                                             |
+| ER_REM_NOSERVER | 8059 | The server process of the remote XAPI is not started or is terminated.                                                                                                                                                                                                                                                                                                                                                                                                             |
+
+# APPENDIX I
+
+## Examples of XAPI access to service providers
+
+The access to the service providers specified in this appendix serve as examples. They do not claim completeness (e.g. the access to a multipoint transport service provider may be specified). The list of specifications presented in this appendix may be extended if required.
+
+An application which requests access to a service has to select an appropriate service provider prior to the usage of the service. Thus the communication system can be tailored to specific requirements, and all communication services are accessible via one homogenous access mechanism.
+
+### Available providers
+
+This appendix contains the following service providers:
+
+- I.1 XAPI access to the service provider for the ISDN B-channel;
+- I.2 XAPI access to the service provider for BFT over T.30;
+- I.3 XAPI access to the service provider for FAX4 and BFT;
+- I.4 XAPI access to the service provider for ACSE and ROSE;
+- I.5 XAPI access to the service provider for audio and video control;
+- I.6 XAPI access to the service provider for T.120 conference control;
+- I.7 XAPI access to the service provider for T.127 MBFT.
+
+## I.1 XAPI access to the service provider for the ISDN B-channel
+
+This part of Appendix I describes an example of how the service provider can be implemented, if an application needs the access to the specified service.
+
+### I.1.1 Scope
+
+The XAPI, which is an abbreviation for eXtensive Application Programming Interface, is an operating system and language-independent programming interface to general communication services. Detailed information about the XAPI is given in the main part of this Recommendation, which is very important for understanding this appendix.
+
+Which services are made available via the XAPI depends on the installed service providers and not on the XAPI, which only provides the access mechanism.
+
+This part describes the XAPI access to the ISDN B-channel.
+
+Figure I.1-1 shows the structure of the protocol stack that is accessible via the XAPI when selecting the ISDN B-channel service:
+
+![Diagram showing the structure of the ISDN B-channel service provider. It consists of three main components: 'Application' at the top, 'XAPI' in the middle, and 'I.430/I.431' at the bottom. A double-headed vertical arrow connects 'Application' and 'XAPI'. A single-headed vertical arrow points from 'XAPI' down to 'I.430/I.431'. Below the 'I.430/I.431' box, the text 'B-channel' is centered, and 'T0827220-97' is positioned to the right.](ee0bf6a260cff72af8f0df0639b6a7c5_img.jpg)
+
+```
+graph TD; Application[Application] <--> XAPI[XAPI]; XAPI --> I430[I.430/I.431];
+```
+
+B-channel T0827220-97
+
+Diagram showing the structure of the ISDN B-channel service provider. It consists of three main components: 'Application' at the top, 'XAPI' in the middle, and 'I.430/I.431' at the bottom. A double-headed vertical arrow connects 'Application' and 'XAPI'. A single-headed vertical arrow points from 'XAPI' down to 'I.430/I.431'. Below the 'I.430/I.431' box, the text 'B-channel' is centered, and 'T0827220-97' is positioned to the right.
+
+**Figure I.1-1/T.180 – Structure of the ISDN B-channel service provider**
+
+### I.1.2 References
+
+The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; all users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published.
+
+[I.430] ITU-T Recommendation I.430 (1995), *Basic user-network interface – Layer 1 specification*.
+
+- [I.431] ITU-T Recommendation I.431 (1993), *Primary rate user-network interface – Layer 1 specification.*
+- [Q.921] ITU-T Recommendation Q.921 (1997), *ISDN User-network interface – Data link layer specification.*
+- [ETS 300 129:1991-09] *Integrated Services Digital Network (ISDN); User-network interface data link layer specifications. Application of CCITT Recommendations Q.920/I.440 and Q.921/I.441.*
+- [Q.931] CCITT Recommendation Q.931 (1988), *ISDN user-network interface layer 3 specification for basic call control.*
+- [ETS 300 102-1:1990-12] *Integrated Services Digital Network (ISDN); User-network interface layer 3; Specifications for basic call control.*
+
+### **I.1.3 Definitions**
+
+### **I.1.4 Abbreviations**
+
+This part uses the following abbreviations:
+
+|       |                                                                                                                                                                              |
+|-------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| DSS 1 | Digital Subscriber Signalling System No. 1                                                                                                                                   |
+| ISDN  | Integrated Services Digital Network                                                                                                                                          |
+| ISO   | International Organization for Standardization                                                                                                                               |
+| NSAP  | Network Service Access Point                                                                                                                                                 |
+| OSI   | Open Systems Interconnection                                                                                                                                                 |
+| PHT   | abbreviation string specifying service specific definitions of the B-channel (PHysical) service provider, Transparent access (e.g. parameter names, service primitive names) |
+| XAPI  | eXtensive Application Programming Interface                                                                                                                                  |
+
+### **I.1.5 Conventions**
+
+Each service is described via three kinds of tables.
+
+In the first kind of table the service and its service elements are described. It contains a row for each service element of the service (where service element means either request, indication, response, or confirmation) with its corresponding XAPI function and a short description.
+
+In the second kind of table the use of the service primitive parameters within the service elements are described. It contains a row for each service primitive parameter of the service. The service primitive parameter name is stored within the first column, the succeeding columns contain the use of the parameter in the service elements:
+
+|       |                                                                                                                                                                                                                                                                                                                                                         |
+|-------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Blank | The service parameter is absent.                                                                                                                                                                                                                                                                                                                        |
+| C     | Presence of the service parameter is conditional. Firstly, there may be a condition in the service provider to provide a parameter in an indication or confirmation. Secondly, there may be interdependencies between parameters of the same or the preceding service primitive.                                                                        |
+| M     | Presence of the service parameter is mandatory.                                                                                                                                                                                                                                                                                                         |
+| U     | Presence of the service parameter is a user option. If the user does not specify a value for such a parameter and there is no default value for that parameter, nothing is passed to the service provider. If the user does not specify a value for such a parameter and there is a default value, the default value is passed to the service provider. |
+
+- (=) The value of the service parameter is identical to the value of the corresponding service parameter in the preceding service element. In the special case of a parameter, whose presence in the preceding service is a user option, for which a default value is defined, and the parameter was not specified in the preceding service element, the symbol (=) indicates that the parameter value is identical to the default value.
+
+The third kind of table is used to describe the service primitive parameter containing the type of value and its scope, possible default values and a detailed description. For each service primitive parameter, one description table is given.
+
+A **naming convention** is used throughout the XAPI in order to distinguish between the common functions, identifiers and values, and service specific identifiers and values. All service-specific settings of the XAPI ISDN B-channel service access are defined within the present part of this appendix and start with **X\_PHT\_** or **x\_pht\_**.
+
+Extended naming conventions:
+
+- SP\_ Service Primitive;
+- P\_ Parameter;
+- PV\_ Parameter Value;
+- O\_ Option;
+- OV\_ Option Value.
+
+### **I.1.6 Introduction to the ISDN physical service provider access**
+
+The ISDN B-channel service handles connection establishment, access to the B-channel for the data transfer and disconnection.
+
+The XAPI gives a uniform access method; it is hidden from the XAPI user whether the D-channel or the B-channel is the destination for a special service request.
+
+### **I.1.7 Description of the access to the ISDN physical service provider**
+
+#### **I.1.7.1 Service initialization**
+
+##### **I.1.7.1.1 Creation of an ISDN B-channel service access point with `x_open()`**
+
+A communication endpoint accessing the ISDN physical service provider is created when calling the `x_open()` function with the service provider identification string "**X\_PHT\_ISDN**".
+
+The service provider comprises the D-channel protocols and the B-channel protocol module on the physical layer. Of course, no transport system has to be linked below it with the `x_bind()` function, as the protocol stack is already complete.
+
+##### **I.1.7.1.2 Activation of an ISDN B-channel service access point with `x_bind()`**
+
+`x_bind()` is to be called to activate the ISDN B-channel service endpoint. The function has the task to bind an address to the service endpoint.
+
+No transport system has to be specified as argument of the `x_bind()` function, as the physical layer is the only layer which is needed in the B-channel.
+
+##### **I.1.7.1.3 Protocol addresses**
+
+The protocol address to be used is the NSAP address. Selectors are meaningless for the ISDN B-channel service.
+
+###### I.1.7.1.3.1 The Application's own Address
+
+The own address may be specified in the *own\_address* buffer of the *bind\_struct* passed as argument to the *x\_bind()* function. For a passive application, it is returned in the *called\_addr* buffer of the *x\_conind()* function.
+
+For a passive application, it is not supported to specify the own responding NSAP address in the *address* buffer of the *call\_struct* in the *x\_conrsp()* function, as this value is not transferred by the network.
+
+NOTE – The specification of the application's own protocol address is completely optional. If no address information is specified, the own address is derived from system configuration information and the bound value is returned as output parameter of the *x\_bind()* function.
+
+The own address consists of the NSAP address only. The NSAP address has to comprise the local ISDN outband address, i.e. the address information used in the D-channel. The own ISDN inband address and subaddress parameters as well as the protocol selectors are meaningless in the ISDN B-channel service. If specified, they will be ignored.
+
+Table I.1-1 shows the address component which has to be specified in the *x\_bind()* call.
+
+**Table I.1-1/T.180 – Address component specified in the *x\_bind()* call**
+
+| ISDN network | Address component | Value                                                                            |
+|--------------|-------------------|----------------------------------------------------------------------------------|
+| ISDN/DSS 1   | A_OUTBAND_ADR     | A decimal digit, which is locally mapped on the Multiple Subscriber Number (MSN) |
+
+###### I.1.7.1.3.2 The address of the communication partner
+
+On the sending side, the address of the communication partner has to be specified in the *address* buffer of the *call\_struct* passed as argument to the *x\_conreq()* function. On the receiving side, the address of the communication partner is returned in the *calling\_addr* buffer of the *x\_conind()* function.
+
+The address of the communication partner comprises at least the peer's ISDN outband address. The peer's ISDN inband address and subaddress as well as the protocol selectors are meaningless, as there is a data transfer in the B-channel without further protocols.
+
+Table I.1-2 shows the address component to be used in the *address* buffer specifying the called NSAP address in an *x\_conreq()* call.
+
+**Table I.1-2/T.180 – Address component specifying the called NSAP address in an *x\_conreq()* call**
+
+| ISDN network | Address component | Value                                                                                      |
+|--------------|-------------------|--------------------------------------------------------------------------------------------|
+| ISDN/DSS 1   | A_OUTBAND_ADR     | Optional the country code, optional the area code and the Multiple Subscriber Number (MSN) |
+
+##### I.1.7.1.4 Configuration of the service provider
+
+The protocol module of the service provider behaves according to configured protocol options. Protocol options are used to control the general behaviour of a protocol module (they must not be confounded with service primitive parameters). The preconfigured values of the protocol options are sufficient for the majority of communication relations.
+
+Currently, there are no options for the protocol modules of the access to the ISDN B-channel, which could be set by the XAPI function *x\_optmgmt()*.
+
+#### **I.1.7.2 Connection Establishment service**
+
+##### **I.1.7.2.1 Service description**
+
+During the connection establishment phase, two users of the same service establish a connection between them. The XAPI user must already have prepared a service endpoint before the connection establishment phase can start.
+
+The service elements and their corresponding XAPI functions needed for Connection Establishment are described in Table I.1-3.
+
+**Table I.1-3/T.180 – Service elements and their corresponding XAPI functions for Connection Establishment**
+
+| <b>Service element</b> | <b>XAPI function</b> | <b>Description</b>                                                                                                                       |
+|------------------------|----------------------|------------------------------------------------------------------------------------------------------------------------------------------|
+| Connect Request        | <i>x_conreq()</i>    | The Connect Request is passed to the provider to request the establishment of a connection.                                              |
+| Connect Indication     | <i>x_conind()</i>    | The Connect Indication is generated by the provider to indicate the request from a remote terminal to establish a connection.            |
+| Connect Response       | <i>x_conrsp()</i>    | The Connect Response is passed to the provider as reaction to a previously received connect indication as positive or negative response. |
+| Connect Confirmation   | <i>x_conconf()</i>   | The Connect Confirmation is generated by the provider as positive or negative confirmation of a local establishment.                     |
+
+##### **I.1.7.2.2 Service parameters**
+
+There are no service parameters to be specified during connection establishment.
+
+#### **I.1.7.3 Services in the connected state**
+
+##### **I.1.7.3.1 Data Transfer service**
+
+###### **I.1.7.3.1.1 Service description**
+
+The Data Transfer service can be used to transfer transparent data in the B-channel.
+
+Flow control, i.e. the ability to read received data fast enough during the data transfer, is up to the XAPI user. Also, the segmentation of larger portions which shall be transmitted is up to the XAPI user.
+
+The service elements and their corresponding XAPI functions needed for Data Transfer are described in Table I.1-4.
+
+**Table I.1-4/T.180 – Service elements and their corresponding XAPI functions for Data Transfer**
+
+| Service elements | XAPI function | Description                                                                     |
+|------------------|---------------|---------------------------------------------------------------------------------|
+| Data Request     | x_snddata()   | The Data Request is passed to the provider to transmit data.                    |
+| Data Indication  | x_rcvdata()   | The Data Indication is generated by the provider to indicate the received data. |
+
+###### **I.1.7.3.1.2 Service parameters**
+
+There are no service parameters defined for the Data Transfer service.
+
+#### **I.1.7.4 Disconnect service**
+
+##### **I.1.7.4.1 Service description**
+
+The Disconnect service allows either service user to disconnect the connection.
+
+The service elements and their corresponding XAPI functions needed for Disconnection are described in Table I.1-5.
+
+**Table I.1-5/T.180 – Service elements and their corresponding XAPI functions for Disconnect**
+
+| Service elements      | XAPI function | Description                                                                                                                                                                                            |
+|-----------------------|---------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Disconnect Request    | x_snddis()    | The Disconnect Request is passed to the provider to request a disconnection.                                                                                                                           |
+| Disconnect Indication | x_rcvdis()    | The Disconnect Indication is generated by the provider to indicate the release of a connection due to peer or to provider.                                                                             |
+| End Indication        | x_rcvend()    | The End Indication is generated by the provider to indicate that the service provider is ready to establish a new connection. In addition, it contains some information about the released connection. |
+
+##### **I.1.7.4.2 Service parameters**
+
+Table I.1-6 specifies the parameters needed for disconnection.
+
+**Table I.1-6/T.180 – Parameters of the Disconnect service**
+
+| Parameter       | Disconnect service |            |                |
+|-----------------|--------------------|------------|----------------|
+|                 | Request            | Indication | End Indication |
+| X_PHT_P_REASON  |                    | M          |                |
+| X_P_CONN_TIME   |                    |            | M              |
+| X_P_DISC_TIME   |                    |            | M              |
+| X_P_CHARGE      |                    |            | C              |
+| X_P_DISC_REASON |                    |            | C              |
+
+##### I.1.7.4.3 Service parameter descriptions
+
+Tables I.1-7 to I.1-11 define the parameters for the Disconnect service.
+
+**Table I.1-7/T.180**
+
+|                |                                                                                                                         |
+|----------------|-------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_PHT_P_REASON                                                                                                          |
+| Type of value  | unsigned long                                                                                                           |
+| Legal values   | The values are directly mapped from the underlying hardware. See the hardware documentation to get further information. |
+| Default value  | none                                                                                                                    |
+| Description    | The parameter indicates the cause of the disconnection.                                                                 |
+
+**Table I.1-8/T.180**
+
+|                |                                                          |
+|----------------|----------------------------------------------------------|
+| Parameter name | X_P_CONN_TIME                                            |
+| Type of value  | unsigned long                                            |
+| Legal values   | the time in seconds since 01.01.1970 00:00:00 GMT        |
+| Default value  | none                                                     |
+| Description    | This parameter contains the time of physical connection. |
+
+**Table I.1-9/T.180**
+
+|                |                                                                                                                                                                     |
+|----------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_P_DISC_TIME                                                                                                                                                       |
+| Type of value  | unsigned long                                                                                                                                                       |
+| Legal values   | the time in seconds since 01.01.1970 00:00:00 GMT                                                                                                                   |
+| Default value  | none                                                                                                                                                                |
+| Description    | This parameter contains the time of physical disconnection. If X_P_CONN_TIME and X_P_DISCON_TIME are both set to zero, no physical connection could be established. |
+
+**Table I.1-10/T.180**
+
+|                |                                                                                                                                                          |
+|----------------|----------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_P_CHARGE                                                                                                                                               |
+| Type of value  | unsigned long                                                                                                                                            |
+| Legal values   | any number                                                                                                                                               |
+| Default value  | zero                                                                                                                                                     |
+| Description    | This parameter contains, if available, the charging unit of the connection. It is only set if both network and network connection provide this facility. |
+
+**Table I.1-11/T.180**
+
+|                |                                                                                                                         |
+|----------------|-------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_P_DISC_REASON                                                                                                         |
+| Type of value  | unsigned long                                                                                                           |
+| Legal values   | The values are directly mapped from the underlying hardware. See the hardware documentation to get further information. |
+| Default value  | zero                                                                                                                    |
+| Description    | This parameter contains, if available, the disconnection reason.                                                        |
+
+#### **I.1.7.5 Usage of XAPI functions**
+
+This subclause provides some protocol-specific remarks to the use of the XAPI functions. The functions are mentioned in alphabetical order.
+
+- **x\_conconf** The user\_data buffer in the *call\_struct* is empty, as transfer of user data is not available in the connection establishment phase.
+- **x\_conind** The user\_data buffer in the *conind\_struct* is empty, as transfer of user data is not available in the connection establishment phase.
+- **x\_conreq** The user\_data buffer in the *call\_struct* is empty, as transfer of user data is not available in the connection establishment phase. Usage of the MORE flag is not supported.
+- **x\_conrsp** The user\_data buffer in the *call\_struct* is empty, as transfer of user data is not available in the connection establishment phase. Usage of the MORE flag is not supported.
+- **x\_rcvdata** Expedited data are not available.
+- **x\_rcvdis** The user\_data buffer in the *discon\_struct* is empty, as transfer of user data is not available in the disconnection.
+- **x\_snddata** Expedited data are not available. Usage of the MORE flag is not supported.
+- **x\_snddis** The user\_data buffer in the *discon\_struct* may not be used, as transfer of user data is not available in the disconnection. Usage of the MORE flag is not supported.
+
+#### **I.1.7.6 Tables of error codes**
+
+The XAPI error-level error codes are defined in Annex B.
+
+##### **I.1.7.6.1 CC\_BADVALUE**
+
+An invalid mandatory parameter is given: *diagnostic* contains the corresponding parameter identifier.
+
+##### **I.1.7.6.2 CC\_MANDMISS**
+
+A mandatory parameter is missing: *diagnostic* contains the number of missing mandatory parameters.
+
+##### **I.1.7.6.3 CC\_BADEVENT**
+
+An invalid event is specified: *diagnostic* contains the bad event identifier.
+
+##### **I.1.7.6.4 CC\_SEQ**
+
+An incorrect sequence number is given: *diagnostic* contains the bad sequence number.
+
+##### **I.1.7.6.5 CC\_SPNAME**
+
+An invalid service primitive name is given: *diagnostic* contains the bad service primitive name.
+
+##### **I.1.7.6.6 CC\_ADDCOMP**
+
+An additional parameter (neither address parameter nor service primitive parameter) is incorrect: no *diagnostic* is given.
+
+##### **I.1.7.6.7 CC\_BADLENGTH**
+
+An address or parameter buffer contains an illegal length value: *diagnostic* contains the length.
+
+##### **I.1.7.6.8 CC\_UNEXPECT**
+
+If the cause code indicates a unexpected event, the value of *diagnostic* will contain the actual state identifier in which the unexpected event caused the error indication.
+
+##### **I.1.7.6.9 CC\_NOTSUPPORT**
+
+An event is given which is not supported: the value of *diagnostic* contains the identifier of the unsupported event which has been submitted with the XAPI function call that caused the error indication.
+
+##### **I.1.7.6.10 CC\_OTHER**
+
+If the cause code indicates the CC\_OTHER error code, the value of *diagnostic* contains the identifier which caused the error indication.
+
+## **I.2 XAPI access to the service provider for BFT over T.30**
+
+This part of Appendix I describes as an example how the service provider can be implemented, if an application needs the access to the specified service.
+
+### **I.2.1 Scope**
+
+The XAPI, which is an abbreviation for eXtensive Application Programming Interface, is an operating system and language-independent programming interface to general communication services. Detailed information about the XAPI is given in the main part of this Recommendation, which is very important for understanding this appendix.
+
+Which services are made available via the XAPI, depends on the installed service providers, and not on the XAPI which only provides the access mechanism.
+
+This part describes the XAPI access to the BFT(T.30) service provider.
+
+Figure I.2-1 shows the structure of the protocol stack that is accessible via the XAPI when selecting the BFT(T.30) service provider:
+
+![Diagram showing the structure of the protocol stack for BFT(T.30) service provider. It consists of three main components: 'Application' at the top, 'XAPI' in the middle, and 'T.30 Adaption Layer for BFT' at the bottom. Double-headed vertical arrows connect 'Application' to 'XAPI' and 'XAPI' to the 'T.30 Adaption Layer for BFT'. Below the 'T.30 Adaption Layer for BFT' box, the text 'B-channel' is centered, and 'T0827230-97' is positioned to the right.](5509e6ec160899dd306e462bb6a3643b_img.jpg)
+
+```
+
+graph TD
+    Application[Application] <--> XAPI[XAPI]
+    XAPI <--> T30[T.30 Adaption Layer for BFT]
+    T30 --- Bchannel[B-channel]
+    T30 --- T082723097[T0827230-97]
+
+```
+
+Diagram showing the structure of the protocol stack for BFT(T.30) service provider. It consists of three main components: 'Application' at the top, 'XAPI' in the middle, and 'T.30 Adaption Layer for BFT' at the bottom. Double-headed vertical arrows connect 'Application' to 'XAPI' and 'XAPI' to the 'T.30 Adaption Layer for BFT'. Below the 'T.30 Adaption Layer for BFT' box, the text 'B-channel' is centered, and 'T0827230-97' is positioned to the right.
+
+**Figure I.2-1/T.180 – Structure of the BFT(T.30) service provider**
+
+### I.2.2 References
+
+The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; all users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published.
+
+- [T.4] ITU-T Recommendation T.4 (1996), *Standardization of Group 3 facsimile terminals for document transmission*.
+- [T.30] ITU-T Recommendation T.30 (1996), *Procedures for document facsimile transmission in the general switched telephone network*.
+- [T.434] ITU-T Recommendation T.434 (1996), *Binary file transfer format for the telematic services*.
+
+### I.2.3 Definitions
+
+This part defines the following terms:
+
+**I.2.3.1 service provider:** A communication system that provides a certain service to user.
+
+**I.2.3.2 transport system:** A protocol stack comprising some or all the OSI layer 1 (physical layer) to 4 (transport layer)
+
+### I.2.4 Abbreviations
+
+This part uses the following abbreviations:
+
+- BF3                      acronym string specifying service specific definitions of the BFT(T.30) provider (e.g. parameter names, service primitive names)
+- BFT                     Binary File Transfer
+
+|       |                                                |
+|-------|------------------------------------------------|
+| DSS 1 | Digital Subscriber Signalling System No. 1     |
+| ISDN  | Integrated Services Digital Network            |
+| ISO   | International Organization for Standardization |
+| NSAP  | Network Service Access Point                   |
+| OSI   | Open Systems Interconnection                   |
+| TWA   | Two-Way Alternate                              |
+| XAPI  | eXtensive Application Programming Interface    |
+
+### 1.2.5 Conventions
+
+Each service is described via three kinds of tables.
+
+In the first table, the service and its service elements are described. It contains a row for each service element of the service (where service element means either request, indication, response, or confirmation) with its corresponding XAPI function and a short description.
+
+In the second table, the use of the service primitive parameters within the service elements are described. It contains a row for each service primitive parameter of the service. The service primitive parameter name is stored within the first column; the following columns contain the use of the parameter in the service elements:
+
+Blank The service parameter is absent.
+
+C Presence of the service parameter is conditional. Firstly, there may be a condition in the service provider to provide a parameter in an indication or confirmation. Secondly, there may be interdependencies between parameters of the same or the preceding service primitive.
+
+M Presence of the service parameter is mandatory.
+
+U Presence of the service parameter is a user option. If the user does not specify a value for such a parameter and there is no default value for that parameter, nothing is passed to the service provider. If the user does not specify a value for such a parameter and there is a default value, the default value is passed to the service provider.
+
+(=) The value of the service parameter is identical to the value of the corresponding service parameter in the preceding service element. In the special case of a parameter, whose presence in the preceding service is a user option, for which a default value is defined, and the parameter was not specified in the preceding service element, the symbol (=) indicates that the parameter value is identical to the default value.
+
+The third kind of table is used to describe the service primitive parameter containing the type of value and its scope, possible default values and a detailed description. For each service primitive parameter, one description table is given.
+
+A **naming convention** is used throughout the XAPI in order to distinguish between the common functions, identifiers and values, and service specific identifiers and values. All service-specific settings of the XAPI BFT(T.30) service access are defined within the present part of this appendix and start with **X\_BF3\_** or **x\_bf3\_**.
+
+Extended naming conventions:
+
+- SP\_ Service Primitive;
+- P\_ Parameter;
+- PV\_ Parameter Value;
+
+- O\_ Option;
+- OV\_ Option Value.
+
+### **I.2.6 Introduction to the BFT(T.30) provider access**
+
+The BFT(T.30) service is provided by a T.30 adaption module, which transmits BFT [T.434] encoded files according to Recommendation [T.30].
+
+It gives the means of synchronized Binary File Transfer between cooperating Telematic applications: An application can:
+
+- establish a connection with another BFT user;
+- exchange binary files in a synchronized manner; and
+- release a connection.
+
+There are no restrictions which are made for implementation.
+
+This implementation expects data encoded according to Binary File Transfer format [T.434] in each *x\_snddata()* and delivers with each *x\_rcvdata()* encoded data in the same format.
+
+### **I.2.7 Description of the access to the BFT(T.30) provider**
+
+#### **I.2.7.1 Service initialization**
+
+##### **I.2.7.1.1 Creation of a BFT(T.30) Service Access Point with *x\_open()***
+
+A communication endpoint accessing the BFT(T.30) service provider is created when calling the *x\_open()* function with the service provider identification string "X\_BFT\_T.30\_ISDN".
+
+The service provider comprises the D-channel protocols and the B-channel protocol module (T.30 adaptation) on the physical layer. Of course, no transport system has to be linked below it with the *x\_bind()* function, as the protocol stack is already complete.
+
+##### **I.2.7.1.2 Activation of BFT(T.30) Service Access Point with *x\_bind()***
+
+*x\_bind()* is to be called to activate the BFT(T.30) service endpoint. The function has the task to bind an address to the service endpoint.
+
+No transport system has to be specified as argument of the *x\_bind()* function, as the T.30 adaptation layer is the only layer which is needed in the B-channel.
+
+##### **I.2.7.1.3 Protocol addresses**
+
+The protocol address to be used is the NSAP address. Selectors are meaningless for the BFT(T.30) service.
+
+###### **I.2.7.1.3.1 The Application's own Address**
+
+The own address may be specified in the *own\_address* buffer of the *bind\_struct* passed as argument to the *x\_bind()* function. It is returned in the *called\_addr* buffer of the *x\_conind()* function.
+
+For a passive application it is not supported to specify the own responding NSAP address in the *address* buffer of the *call\_struct* in the *x\_conrsp()* function, as this value is not transferred by the network.
+
+NOTE – The specification of the application's own protocol address is completely optional. If no address information is specified, the own address is derived from system configuration information and the bound value is returned as output parameter of the *x\_bind()* function.
+
+The own address consists of the NSAP address only. The NSAP address has to comprise the local ISDN outband address, i.e. the address information used in the D-channel. The own ISDN inband address and subaddress parameters as well as the protocol selectors are meaningless in the BFT(T.30) service. If specified, they will be ignored.
+
+Table I.2-1 shows the address component which has to be specified in the *x\_bind()* call.
+
+**Table I.2-1/T.180 – Address component specified in the *x\_bind()* call**
+
+| ISDN network | Address component | Value                                                                            |
+|--------------|-------------------|----------------------------------------------------------------------------------|
+| ISDN/DSS 1   | A_OUTBAND_ADR     | A decimal digit, which is locally mapped on the MSN (multiple subscriber number) |
+
+###### **I.2.7.1.3.2 The address of the communication partner**
+
+On the sending side the address of the communication partner has to be specified in the *address* buffer of the *call\_struct* passed as argument to the *x\_conreq()* function. On the receiving side the address of the communication partner is returned in the *calling\_addr* buffer of the *x\_conind()* function.
+
+The address of the communication partner comprises at least the peer's ISDN outband address. The peer's ISDN inband address and subaddress as well as the protocol selectors are meaningless, as there is a transparent data transfer in the B-channel without further protocols.
+
+Table I.2-2 shows the address component to be used in the *address* buffer specifying the called NSAP address in an *x\_conreq()* call.
+
+**Table I.2-2/T.180 – Address component specifying the called NSAP address in an *x\_conreq()* call**
+
+| ISDN network | Address component | Value                                                                                       |
+|--------------|-------------------|---------------------------------------------------------------------------------------------|
+| ISDN/DSS 1   | A_OUTBAND_ADR     | Optional the country code, optional the area code, and the Multiple Subscriber Number (MSN) |
+
+##### **I.2.7.1.4 Configuration of the service provider**
+
+The protocol module of the service provider behaves according to configured protocol options. Protocol options are used to control the general behaviour of a protocol module (they must not be confounded with service primitive parameters). The preconfigured values of the protocol options are sufficient for the majority of communication relations.
+
+Currently, there are no options for the protocol modules of the BFT(T.30) service provider which could be set by the XAPI function *x\_optmgmt()*.
+
+#### **I.2.7.2 Connection Establishment service**
+
+##### **I.2.7.2.1 Service description**
+
+During connection establishment phase two users of the same service establish a connection between each other. Both users must have already prepared an active service endpoint before they can enter the connection establishment phase.
+
+The service elements and their corresponding XAPI functions needed for BFT(T.30) Connection Establishment are described in Table I.2-3.
+
+**Table I.2-3/T.180 – Service elements and their corresponding XAPI functions  
+for Connection Establishment**
+
+| Service element      | XAPI function      | Description                                                                                                                                      |
+|----------------------|--------------------|--------------------------------------------------------------------------------------------------------------------------------------------------|
+| Connect Request      | <i>x_conreq()</i>  | The Connect Request service is passed to the provider to request the establishment of a BFT(T.30) connection.                                    |
+| Connect Indication   | <i>x_conind()</i>  | The Connect Indication service is generated by the provider to indicate the request from a remote terminal to establish a BFT(T.30) connection.  |
+| Connect Response     | <i>x_conrsp()</i>  | The Connect Response service is passed to the provider as reaction to a previously received connect indication as positive or negative response. |
+| Connect Confirmation | <i>x_conconf()</i> | The Connect Confirmation service is generated by the provider as positive or negative confirmation of a local BFT(T.30) establishment.           |
+
+##### **I.2.7.2.2 Service parameters**
+
+There are no service parameters defined for the Connection Establishment service.
+
+#### **I.2.7.3 Services in the connected state**
+
+The T.30 adaption layer for BFT provides several services in the connected state. While the service endpoint used to access the provider is in state X\_CONNECTED these service primitives can be passed to the provider *rsp.* retrieved from the provider with calls of *x\_snddata()* and *x\_sndsp()* *rsp.* *x\_rcvdata()* and *x\_rcvsp()*.
+
+The data transfer works in a so called TWA (Two-Way Alternate) mode. This means the initiator and responder act in a sink/source relationship, in which only one of them may send data at a time. The owner of the Data Token, which is the initiator of the connection when entering the X\_CONNECTED state, may then give control to the responder by issuing the X\_BF3\_SP\_GIVE\_TOKEN\_Q service primitive.
+
+##### **I.2.7.3.1 Data Transfer service**
+
+###### **I.2.7.3.1.1 Service description**
+
+The Data Transfer service allows the BFT(T.30) service users to transfer files alternately.
+
+The service elements and their corresponding XAPI functions needed for Data Transfer are described in Table I.2-4.
+
+**Table I.2-4/T.180 – Service elements and their corresponding XAPI functions  
+for Data Transfer**
+
+| Service element | XAPI function      | Description                                                                             |
+|-----------------|--------------------|-----------------------------------------------------------------------------------------|
+| Data Request    | <i>x_snddata()</i> | The Data Request service is passed to the provider to transmit data.                    |
+| Data Indication | <i>x_rcvdata()</i> | The Data Indication service is generated by the provider to indicate the received data. |
+
+###### I.2.7.3.1.2 Service parameters
+
+There are no service parameters defined for the Data Transfer service.
+
+##### I.2.7.3.2 Checkpoint service
+
+###### I.2.7.3.2.1 Service description
+
+The BFT(T.30) service uses a checkpoint mechanism in the file transfer. This means each checkpoint in BFT mode is confirmed by the receiver.
+
+The service elements and their corresponding XAPI functions needed for the Checkpoint service are described in Table I.2-5.
+
+**Table I.2-5/T.180 – Service elements and their corresponding XAPI functions for the Checkpoint service**
+
+| Service element         | XAPI function | Service element identifier | Description                                                                                                                   |
+|-------------------------|---------------|----------------------------|-------------------------------------------------------------------------------------------------------------------------------|
+| Checkpoint Request      | x_sndsp()     | X_BF3_SP_CHK_Q             | The Checkpoint Request is passed to the provider to request the checkpointing from the active side.                           |
+| Checkpoint Indication   | x_rcvsp()     | X_BF3_SP_CHK_I             | The Checkpoint Indication is generated by the provider at the passive side to indicate the reception of a Checkpoint Request. |
+| Checkpoint Response     | x_sndsp()     | X_BF3_SP_CHK_P             | The Checkpoint Response is passed to the provider to confirm the checkpoint at the passive side.                              |
+| Checkpoint Confirmation | x_rcvsp()     | X_BF3_SP_CHK_C             | The Checkpoint Confirmation is given to the sender of the Checkpoint Request as acknowledgement of the command.               |
+
+###### I.2.7.3.2.2 Service parameter
+
+Table I.2-6 specifies the parameters of the Checkpoint service.
+
+**Table I.2-6/T.180 – Parameters of the Checkpoint service**
+
+| Parameter      | Checkpoint service |            |          |              |
+|----------------|--------------------|------------|----------|--------------|
+|                | Request            | Indication | Response | Confirmation |
+| X_BF3_P_CHK_NR | M                  | M (=)      | M (=)    | M (=)        |
+
+###### I.2.7.3.2.3 Service parameter description
+
+Table I.2-7 describes the parameter for the Checkpoint service.
+
+**Table I.2-7/T.180**
+
+|                |                                                   |
+|----------------|---------------------------------------------------|
+| Parameter name | X_BF3_P_CHK_NR                                    |
+| Type of value  | unsigned long                                     |
+| Legal values   | any number greater than zero                      |
+| Default value  | none                                              |
+| Description    | This parameter identifies the current checkpoint. |
+
+##### I.2.7.3.3 End of File service
+
+###### I.2.7.3.3.1 Service description
+
+The BFT(T.30) service uses a checkpoint mechanism in the file transfer. If the last data was transmitted, the End of File service is used.
+
+The service elements and their corresponding XAPI functions needed for the End of File service are described in Table I.2-8.
+
+**Table I.2-8/T.180 – Service elements and their corresponding XAPI functions for the End of File service**
+
+| Service element          | XAPI function | Service element identifier | Description                                                                                                                    |
+|--------------------------|---------------|----------------------------|--------------------------------------------------------------------------------------------------------------------------------|
+| End of File Request      | x_sndsp()     | X_BF3_SP_EOF_Q             | The End of File Request is passed to the provider to request the final checkpoint from the active side.                        |
+| End of File Indication   | x_rcvsp()     | X_BF3_SP_EOF_I             | The End of File Indication is generated by the provider at the passive side to indicate the reception of the final checkpoint. |
+| End of File Response     | x_sndsp()     | X_BF3_SP_EOF_P             | The End of File Response is passed to the provider to confirm the final checkpoint at the passive side.                        |
+| End of File Confirmation | x_rcvsp()     | X_BF3_SP_EOF_C             | The End of File Confirmation is sent to the originator of the End of File Request as acknowledgement of the command.           |
+
+###### I.2.7.3.3.2 Service parameter
+
+Table I.2-9 specifies the parameter of the End of File service.
+
+**Table I.2-9/T.180 – Parameter of the End of File service**
+
+| Parameter      | Checkpoint service |            |          |              |
+|----------------|--------------------|------------|----------|--------------|
+|                | Request            | Indication | Response | Confirmation |
+| X_BF3_P_CHK_NR | M                  | M (=)      | M (=)    | M (=)        |
+
+##### I.2.7.3.3 Service parameter description
+
+Table I.2-10 describes the parameter for the Checkpoint service.
+
+**Table I.2-10/T.180**
+
+|                |                                                   |
+|----------------|---------------------------------------------------|
+| Parameter name | X_BF3_P_CHK_NR                                    |
+| Type of value  | unsigned long                                     |
+| Legal values   | any number greater than zero                      |
+| Default value  | none                                              |
+| Description    | This parameter identifies the current checkpoint. |
+
+##### I.2.7.3.4 Data Token service
+
+###### I.2.7.3.4.1 Service description
+
+As stated above, data transfer works in a so-called TWA (Two-Way Alternate) mode. This means, the initiator and the responder act in a sink/source relationship, in which only one of them may send data at a time. The owner of the Data Token may give control to the responder by issuing the X\_BF3\_SP\_GIVE\_TOKEN\_Q service primitive.
+
+The service elements and their corresponding XAPI functions needed for the Data Token service are described in Table I.2-11.
+
+**Table I.2-11/T.180 – Service elements and their corresponding XAPI functions for the Data Token service**
+
+| Service element      | XAPI function | Service element identifier | Description                                                                                                                                                                                                                             |
+|----------------------|---------------|----------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Data Token Request   | x_sndsp()     | X_BF3_SP_DATA_TOKEN_Q      | The Data Token Request is passed to the provider to hand over the right for transmitting data from the active side to the passive side. The active side becomes now the passive side and the passive side becomes now the active side.  |
+| DataToken Indication | x_revsp()     | X_BF3_SP_DATA_TOKEN_I      | The Data Token Indication is generated by the provider to indicate that the remote side has handed over the right for transmitting data. The active side becomes now the passive side and the passive side becomes now the active side. |
+
+###### I.2.7.3.4.2 Service parameters
+
+There are no service parameters defined for the Data Token service.
+
+##### I.2.7.3.5 States in the connected state
+
+In the BFT(T.30) protocol, the data transfer is managed in eight states, which may be entered by the service provider while the endpoint used for access is in state X\_CONNECTED:
+
+States which are entered, if the service provider is the initiator (active side) (see Figure I.2-2):
+
+- state 10 This is the initial state. It is entered when the service endpoint enters state X\_CONNECTED. The service user is now able to transmit data with x\_snddata(). This is the only state from which an X\_BF3\_SP\_DATA\_TOKEN\_Q can be issued. In all data transfer states abortive disconnection has to be used to end the communication.
+- state 11 This state is entered after sending data with x\_snddata(). In this state, the user may send more data (x\_snddata()), send X\_BF3\_SP\_CHK\_Q to indicate a checkpoint, or X\_BF3\_SP\_EOF\_Q to indicate the end of the file. This state is also entered when an X\_BF3\_SP\_CHK\_C was received, which indicates that the checkpoint is confirmed.
+- state 12 This state is entered when an X\_BF3\_SP\_CHK\_Q was sent and an X\_BF3\_SP\_CHK\_C is pending.
+- state 13 This state is entered, when an X\_BF3\_SP\_EOF\_Q was sent and an X\_BF3\_SP\_EOF\_C is pending.
+
+![State transition diagram for data transfer states in active mode. The diagram shows five states: state 10, state 11, state 12, state 13, and state 20. Transitions are as follows: state 10 to state 11 via x_snddata(); state 10 to state 20 via X_BF3_SP_DATA_TOKEN_Q; state 11 to state 11 via x_snddata(); state 11 to state 12 via X_BF3_SP_CHK_Q; state 11 to state 13 via X_BF3_SP_EOF_Q; state 12 to state 11 via X_BF3_SP_CHK_C; state 13 to state 10 via X_BF3_SP_EOF_C. A reference T0827240-97 is noted near state 13.](886963464425186f4a465fa8155d2a3c_img.jpg)
+
+```
+graph TD
+    state10([state 10]) -- "x_snddata()" --> state11([state 11])
+    state10 -- "X_BF3_SP_DATA_TOKEN_Q" --> state20([state 20])
+    state11 -- "x_snddata()" --> state11
+    state11 -- "X_BF3_SP_CHK_Q" --> state12([state 12])
+    state11 -- "X_BF3_SP_EOF_Q" --> state13([state 13])
+    state12 -- "X_BF3_SP_CHK_C" --> state11
+    state13 -- "X_BF3_SP_EOF_C" --> state10
+```
+
+State transition diagram for data transfer states in active mode. The diagram shows five states: state 10, state 11, state 12, state 13, and state 20. Transitions are as follows: state 10 to state 11 via x\_snddata(); state 10 to state 20 via X\_BF3\_SP\_DATA\_TOKEN\_Q; state 11 to state 11 via x\_snddata(); state 11 to state 12 via X\_BF3\_SP\_CHK\_Q; state 11 to state 13 via X\_BF3\_SP\_EOF\_Q; state 12 to state 11 via X\_BF3\_SP\_CHK\_C; state 13 to state 10 via X\_BF3\_SP\_EOF\_C. A reference T0827240-97 is noted near state 13.
+
+**Figure I.2-2/T.180 – Data transfer states in active mode**
+
+States which are entered, if the service provider is the responder (receiving side) (see Figure I.2-3):
+
+- state 20 This is the initial state. It is entered when the service endpoint enters state X\_CONNECTED. The service user may now receive Data with the function x\_rcvdata(). If an X\_BF3\_SP\_GIVE\_TOKEN\_I was received, the automaton enters the state10. In all data transfer states abortive disconnection has to be used to end the communication.
+- state 21 This state is entered after receiving data with x\_rcvdata(). In this state, the user may receive more data (x\_rcvdata()), receive X\_BF3\_SP\_CHK\_I to indicate a checkpoint, or X\_BF3\_SP\_EOF\_I to indicate the end of the file. This state is also entered, when an X\_BF3\_SP\_CHK\_P was sent, which indicates that the checkpoint is confirmed.
+
+- state 22 This state is entered when an X\_BF3\_SP\_CHK\_I was received, which indicates a checkpoint. The service user has now to confirm this checkpoint by sending an X\_BF3\_SP\_CHK\_P.
+- state 23 This state is entered when an X\_BF3\_SP\_EOF\_I was received, which indicates the successfully transmission of the whole file. The service user has now to confirm the end of the file with X\_BF3\_SP\_EOF\_P.
+
+![State transition diagram for data transfer states in passive mode. The diagram shows five states: state 10, state 20, state 21, state 22, and state 23. Transitions are as follows: state 20 to state 10 via X_BF3_SP_DATA_TOKEN_I; state 20 to state 21 via x_rcvdata(); state 21 to state 20 via x_rcvdata(); state 21 to state 23 via X_BF3_SP_EOF_I; state 23 to state 20 via X_BF3_SP_EOF_P; state 21 to state 22 via X_BF3_SP_CHK_I; state 22 to state 21 via X_BF3_SP_CHK_P. There is a self-loop on state 21 labeled x_rcvdata(). A reference T0827250-97 is noted near state 23.](6f46eccb86e008f8bc7af8ea3ab806a7_img.jpg)
+
+```
+
+graph TD
+    state10([state 10])
+    state20([state 20])
+    state21([state 21])
+    state22([state 22])
+    state23([state 23])
+
+    state20 -- "X_BF3_SP_DATA_TOKEN_I" --> state10
+    state20 -- "x_rcvdata()" --> state21
+    state21 -- "x_rcvdata()" --> state20
+    state21 -- "X_BF3_SP_EOF_I" --> state23
+    state23 -- "X_BF3_SP_EOF_P" --> state20
+    state21 -- "X_BF3_SP_CHK_I" --> state22
+    state22 -- "X_BF3_SP_CHK_P" --> state21
+    state21 -- "x_rcvdata()" --> state21
+  
+```
+
+State transition diagram for data transfer states in passive mode. The diagram shows five states: state 10, state 20, state 21, state 22, and state 23. Transitions are as follows: state 20 to state 10 via X\_BF3\_SP\_DATA\_TOKEN\_I; state 20 to state 21 via x\_rcvdata(); state 21 to state 20 via x\_rcvdata(); state 21 to state 23 via X\_BF3\_SP\_EOF\_I; state 23 to state 20 via X\_BF3\_SP\_EOF\_P; state 21 to state 22 via X\_BF3\_SP\_CHK\_I; state 22 to state 21 via X\_BF3\_SP\_CHK\_P. There is a self-loop on state 21 labeled x\_rcvdata(). A reference T0827250-97 is noted near state 23.
+
+**Figure I.2-3/T.180 – Data transfer states in passive mode**
+
+#### I.2.7.4 Connection Abort service
+
+##### I.2.7.4.1 Service description
+
+The abort service provides the means by which either BFT(T.30) service user or provider can instantaneously release the connection and have the other BFT(T.30) service user informed of the release. Use of this service will cause loss of undelivered data.
+
+The service elements and their corresponding XAPI functions needed for abort of BFT(T.30) connection are described in Table I.2-12.
+
+**Table I.2-12/T.180 – Service elements and their corresponding XAPI functions for the Connection Abort service**
+
+| Service element  | XAPI function | Description                                                                                                                   |
+|------------------|---------------|-------------------------------------------------------------------------------------------------------------------------------|
+| Abort Request    | x_snddis()    | The Abort Request is passed to the provider to request an abnormal BFT(T.30) connection release.                              |
+| Abort Indication | x_rcvdis()    | The Abort Indication is generated by the provider to indicate the abnormal release of a BFT(T.30) connection.                 |
+| End Indication   | x_rcvend()    | The End Indication is generated by the provider to indicate that the service provider is ready to establish a new connection. |
+
+##### I.2.7.4.2 Service parameter
+
+Table I.2-13 specifies the parameter needed for a abortive BFT(T.30) release.
+
+**Table I.2-13/T.180 – Parameters of the Connection Abort service**
+
+| Parameter      | Abort service |            |                |
+|----------------|---------------|------------|----------------|
+|                | Request       | Indication | End Indication |
+| X_BF3_P_REASON |               | U          |                |
+
+##### I.2.7.4.3 Service parameter description
+
+Table I.2-14 defines the parameter for the abort service.
+
+**Table I.2-14/T.180**
+
+|                |                                                         |                                                  |    |
+|----------------|---------------------------------------------------------|--------------------------------------------------|----|
+| Parameter name | X_FX3_P_REASON                                          |                                                  |    |
+| Type of value  | unsigned long                                           |                                                  |    |
+| Legal values   | X_FX3_PV_R_NOREASON                                     | /* no reason                                     | */ |
+|                | X_FX3_PV_R_NOBFT                                        | /* connection establishment not possible, no     | */ |
+|                |                                                         | /* facsimile terminal reached                    | */ |
+|                | X_FX3_PV_R_SLOW                                         | /* error during file transfer, delivered         | */ |
+|                |                                                         | /* data too slow                                 | */ |
+|                | X_FX3_PV_R_NOANS                                        | /* abort because of incorrect behaviour          |    |
+|                |                                                         | of remote terminal                               | */ |
+|                | X_FX3_PV_R_REMDISC                                      | /* remote disconnect                             | */ |
+|                | X_FX3_PV_R_NOCMD                                        | /* unexpected disconnect during file reception   | */ |
+|                | X_FX3_PV_R_INCOMPAT                                     | /* Transfer mode is not supported by             |    |
+|                |                                                         | remote terminal, e.g.                            | */ |
+|                |                                                         | /* high resolution, file transfer                | */ |
+|                | X_FX3_PV_R_BADDATA                                      | /* error during file transfer, wrong encoded BFT | */ |
+|                | X_FX3_PV_R_PROTO                                        | /* protocol error, the remote terminal does not  | */ |
+|                |                                                         | /* conform to T.30                               | */ |
+| Default value  | X_FX3_PV_R_NOREASON                                     |                                                  |    |
+| Description    | The parameter indicates the cause of the disconnection. |                                                  |    |
+
+#### I.2.7.5 Usage of XAPI functions
+
+This subclause provides some protocol-specific remarks to XAPI functions. The functions are mentioned in alphabetical order. If a function is not listed, there are no special remarks.
+
+- **x\_conconf** The user\_data buffer in the *call\_struct* is empty, as transfer of user data is not available in the connection establishment phase.
+- **x\_conind** The user\_data buffer in the *conind\_struct* is empty, as transfer of user data is not available in the connection establishment phase.
+- **x\_conreq** The user\_data buffer in the *call\_struct* is empty, as transfer of user data is not available in the connection establishment phase. Usage of the MORE flag is not supported.
+- **x\_conrsp** The user\_data buffer in the *call\_struct* is empty, as transfer of user data is not available in the connection establishment phase. Usage of the MORE flag is not supported.
+
+- **x\_rcvdis** The user\_data buffer in the *discon\_struct* is empty, as transfer of user data is not available in the disconnection.
+- **x\_snddata** This function can only be called if BFT(T.30) service provider is in state 10 or state 11. Expedited data is not available at the XAPI BFT(T.30) service access point. Usage of the MORE flag is not supported.
+- **x\_snddis** The user\_data buffer in the *discon\_struct* may not be used, as transfer of user data is not available in the disconnection. Usage of the MORE flag is not supported.
+- **x\_sndsp** Usage of the MORE flag is not supported.
+
+#### **I.2.7.6 Tables of error codes**
+
+The XAPI error-level error codes are defined in Annex B.
+
+##### **I.2.7.6.1 CC\_BADVALUE**
+
+An invalid mandatory parameter is given: *diagnostic* contains the corresponding parameter identifier.
+
+##### **I.2.7.6.2 CC\_MANDMISS**
+
+A mandatory parameter is missing: *diagnostic* contains the number of missing mandatory parameters.
+
+##### **I.2.7.6.3 CC\_BADEVENT**
+
+An invalid event is specified: *diagnostic* contains the bad event identifier.
+
+##### **I.2.7.6.4 CC\_SEQ**
+
+An incorrect sequence number is given: *diagnostic* contains the bad sequence number.
+
+##### **I.2.7.6.5 CC\_SPNAME**
+
+An invalid service primitive name is given: *diagnostic* contains the bad service primitive name.
+
+##### **I.2.7.6.6 CC\_ADDCOMP**
+
+An additional parameter (neither address parameter nor service primitive parameter) is incorrect: no *diagnostic* is given.
+
+##### **I.2.7.6.7 CC\_BADLENGTH**
+
+An address or parameter buffer contains an illegal length value: *diagnostic* contains the length.
+
+##### **I.2.7.6.8 CC\_UNEXPECT**
+
+If the cause code indicates an unexpected event: the value of *diagnostic* will contain the actual state identifier in which the unexpected event caused the error indication. Table I.2-15 contains the values defined for the *diagnostic* parameter.
+
+**Table I.2-15/T.180**
+
+| <b>Name</b>    | <b>Description</b>                                                                                                                                                                                                                               |
+|----------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| X_BF3_STATE_10 | A service is requested, which is not expected in this state. Only the following services are expected: <ul style="list-style-type: none"> <li>• X_BF3_SP_DATA_TOKEN_Q</li> <li>• x_snddata()</li> <li>• x_snddis()</li> </ul>                    |
+| X_BF3_STATE_11 | A service is requested, which is not expected in this state. Only the following services are expected: <ul style="list-style-type: none"> <li>• x_snddata()</li> <li>• X_BF3_SP_CHK_Q</li> <li>• X_BF3_SP_EOF_Q</li> <li>• x_snddis()</li> </ul> |
+| X_BF3_STATE_12 | A service is requested, which is not expected in this state. Only the following service is expected: <ul style="list-style-type: none"> <li>• x_snddis()</li> </ul>                                                                              |
+| X_BF3_STATE_13 | A service is requested, which is not expected in this state. Only the following service is expected: <ul style="list-style-type: none"> <li>• x_snddis()</li> </ul>                                                                              |
+| X_BF3_STATE_20 | A service is requested, which is not expected in this state. Only the following service is expected: <ul style="list-style-type: none"> <li>• x_snddis()</li> </ul>                                                                              |
+| X_BF3_STATE_21 | A service is requested, which is not expected in this state. Only the following service is expected: <ul style="list-style-type: none"> <li>• x_snddis()</li> </ul>                                                                              |
+| X_BF3_STATE_22 | A service is requested, which is not expected in this state. Only the following services are expected: <ul style="list-style-type: none"> <li>• X_BF3_SP_CHK_P</li> <li>• x_snddis()</li> </ul>                                                  |
+| X_BF3_STATE_23 | A service is requested, which is not expected in this state. Only the following services are expected: <ul style="list-style-type: none"> <li>• X_BF3_SP_EOF_P</li> <li>• x_snddis()</li> </ul>                                                  |
+
+##### **I.2.7.6.9 CC\_NOTSUPPORT**
+
+An event is given which is not supported: the value of *diagnostic* contains the identifier of the unsupported event which has been submitted with the XAPI function call that caused the error indication.
+
+##### **I.2.7.6.10 CC\_OTHER**
+
+If the cause code indicates the CC\_OTHER error code, the value of *diagnostic* contains the identifier which caused the error indication.
+
+#### I.2.7.7 Table of service primitives
+
+**Table I.2-16/T.180**
+
+| Name                  | Description              |
+|-----------------------|--------------------------|
+| X_BF3_SP_DATA_TOKEN_Q | Data token request       |
+| X_BF3_SP_DATA_TOKEN_I | Data token indication    |
+| X_BF3_SP_CHK_Q        | Checkpoint request       |
+| X_BF3_SP_CHK_I        | Checkpoint indication    |
+| X_BF3_SP_CHK_P        | Checkpoint response      |
+| X_BF3_SP_CHK_C        | Checkpoint confirmation  |
+| X_BF3_SP_EOF_Q        | End of file request      |
+| X_BF3_SP_EOF_I        | End of file indication   |
+| X_BF3_SP_EOF_P        | End of file response     |
+| X_BF3_SP_EOF_C        | End of file confirmation |
+
+#### I.2.7.8 Table of service primitive parameters
+
+**Table I.2-17/T.180**
+
+| Name           | Legal values                                                                                                                                                                              |
+|----------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| X_BF3_P_CHK_NR | number greater than 0                                                                                                                                                                     |
+| X_BF3_P_REASON | X_FX3_PV_R_NOREASON<br>X_FX3_PV_R_NOBFT<br>X_FX3_PV_R_SLOW<br>X_FX3_PV_R_NOANS<br>X_FX3_PV_R_REMDISC<br>X_FX3_PV_R_NOCMD<br>X_FX3_PV_R_INCOMPAT<br>X_FX3_PV_R_BADDATA<br>X_FX3_PV_R_PROTO |
+
+## I.3 XAPI access to the service provider for FAX4 and BFT
+
+This part of Appendix I describes an example of how the service provider can be implemented, if an application needs the access to the specified service.
+
+### I.3.1 Scope
+
+The XAPI, which is an abbreviation for eXtensive Application Programming Interface, is an operating system and language-independent programming interface to general communication services. Detailed information about the XAPI is given in the main part of this Recommendation, which is very important for understanding this appendix.
+
+Which services are made available via the XAPI depends on the installed service providers and not on the XAPI, which only provides the access mechanism.
+
+This part describes the XAPI access to the FAX4/BFT service provider.
+
+Figure I.3-1 shows the structure of the protocol stack that is accessible via the XAPI when selecting the FAX4/BFT service provider:
+
+![Figure I.3-1/T.180 – Structure of the FAX4/BFT service provider. The diagram shows a vertical stack of five components connected by bidirectional arrows. From top to bottom: 'Application', 'XAPI' (shaded box), 'FAX4/BFT protocol module', 'T.62 protocol module', and 'Transport system comprising layers 1-4'. A reference code 'T0827260-97' is located at the bottom right of the diagram.](48adb97a6a4a14b039450192f25cc1e0_img.jpg)
+
+```
+graph TD; Application[Application] <--> XAPI[XAPI]; XAPI <--> FAX4[FAX4/BFT protocol module]; FAX4 <--> T62[T.62 protocol module]; T62 <--> Transport[Transport system comprising layers 1-4];
+```
+
+T0827260-97
+
+Figure I.3-1/T.180 – Structure of the FAX4/BFT service provider. The diagram shows a vertical stack of five components connected by bidirectional arrows. From top to bottom: 'Application', 'XAPI' (shaded box), 'FAX4/BFT protocol module', 'T.62 protocol module', and 'Transport system comprising layers 1-4'. A reference code 'T0827260-97' is located at the bottom right of the diagram.
+
+**Figure I.3-1/T.180 – Structure of the FAX4/BFT service provider**
+
+The XAPI user is able to select one transport system (comprising layers 1 to 4) among the set of transport systems available in the XAPI communication platform to act as the underlying transport service provider.
+
+### **I.3.2 References**
+
+The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations are subject to revision; all users of this Recommendation and other references are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published.
+
+- [T.62] ITU-T Recommendation T.62 (1993), *Control procedures for teletex and Group 4 facsimile services*.
+- [T.434] ITU-T Recommendation T.434 (1996), *Binary file transfer format for the telematic services*.
+
+- [T.503] CCITT Recommendation T.503 (1991), *A document application profile for the interchange of Group 4 facsimile documents.*
+- [T.563] ITU-T Recommendation T.563 (1996), *Terminal characteristics for Group 4 facsimile apparatus.*
+- [T.571] CCITT Recommendation T.571 (1992), *Terminal characteristics for the telematic file transfer within the teletex service.*
+
+### **I.3.3 Definitions**
+
+### **I.3.4 Abbreviations**
+
+This part uses the following abbreviations:
+
+|       |                                                                                                                                 |
+|-------|---------------------------------------------------------------------------------------------------------------------------------|
+| BFT   | Binary File Transfer                                                                                                            |
+| DSS 1 | Digital Subscriber Signalling System No. 1                                                                                      |
+| FX4   | acronym string specifying service specific definitions of the FAX4/BFT provider (e.g. parameter names, service primitive names) |
+| HDLC  | High-Level Data-Link Control                                                                                                    |
+| ISDN  | Integrated Services Digital Network                                                                                             |
+| ISO   | International Organization for Standardization                                                                                  |
+| NSAP  | Network Service Access Point                                                                                                    |
+| OSI   | Open Systems Interconnection                                                                                                    |
+| XAPI  | eXtensive Application Programming Interface                                                                                     |
+
+### **I.3.5 Conventions**
+
+Each service is described via three kinds of tables.
+
+In the first kind of table the service and its service elements are described. It contains a row for each service element of the service (where service element means either request, indication, response, or confirmation) with its corresponding XAPI function and a short description.
+
+In the second kind of table the use of the service primitive parameters within the service elements are described. It contains a row for each service primitive parameter of the service. The service primitive parameter name is stored within the first column; the following columns contain the use of the parameter in the service elements:
+
+|       |                                                                                                                                                                                                                                                                                                                                                         |
+|-------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Blank | The service parameter is absent.                                                                                                                                                                                                                                                                                                                        |
+| C     | Presence of the service parameter is conditional. Firstly, there may be a condition in the service provider to provide a parameter in an indication or confirmation. Secondly, there may be interdependencies between parameters of the same or the preceding service primitive.                                                                        |
+| M     | Presence of the service parameter is mandatory.                                                                                                                                                                                                                                                                                                         |
+| U     | Presence of the service parameter is a user option. If the user does not specify a value for such a parameter and there is no default value for that parameter, nothing is passed to the service provider. If the user does not specify a value for such a parameter and there is a default value, the default value is passed to the service provider. |
+
+- (=) The value of the service parameter is identical to the value of the corresponding service parameter in the preceding service element. In the special case of a parameter, whose presence in the preceding service is a user option, for which a default value is defined, and the parameter was not specified in the preceding service element, the symbol (=) indicates that the parameter value is identical to the default value.
+
+The third kind of table is used to describe the service primitive parameter containing the type of value and its scope, possible default values and a detailed description. For each service primitive parameter, one description table is given.
+
+A **naming convention** is used throughout the XAPI in order to distinguish between the common functions, identifiers and values and service-specific identifiers and values. All service-specific settings of the XAPI FAX4/BFT service access are defined within the present part of this appendix and start with **X\_FX4\_** or **x\_fx4\_**.
+
+Extended naming conventions:
+
+- SP\_ Service Primitive;
+- P\_ Parameter;
+- PV\_ Parameter Value;
+- O\_ Option;
+- OV\_ Option Value.
+
+### **I.3.6 Introduction to the FAX4/BFT service provider access**
+
+The FAX4/BFT service is provided by the combination of a transport system selected by the application and the FAX4/BFT protocol module. The FAX4/BFT protocol module is implemented according to the Recommendations [T.503], [T.563], [T.434] and [T.571] and resides on top of [T.62].
+
+It gives the means of synchronized FAX4/Binary File Transfer between cooperating Telematic applications: An application can:
+
+- establish a connection with another FAX4/BFT user;
+- exchange facsimile/binary files in a synchronized manner; and
+- release connection in an orderly manner.
+
+Each protocol element is directly mapped to the corresponding session protocol element of T.62. The only restriction is that resuming of interrupted documents is currently not accessible to the user of the FAX4/BFT service.
+
+The implementation expects T.6 coded Data in case of Facsimile Group 4 and in case of BFT any binary data in each *x\_snddata()* call. All ASN.1 coding is done within the service provider. The checkpointing (page boundary) must be initiated by the service user. In case of BFT a checkpoint should be inserted every 2 kilo-octets (according to Recommendation T.571) but other values may be used to improve transmission speed.
+
+### **I.3.7 Description of the access to the FAX4/BFT service provider**
+
+#### **I.3.7.1 Service initialization**
+
+##### **I.3.7.1.1 Selection of the FAX4/BFT service provider with *x\_open()***
+
+A communication endpoint accessing the FAX4/BFT service provider is created when calling the *x\_open()* function with an appropriate service provider identification string. The available identifiers
+
+depend on the actual system configuration. In the standard configuration, "X\_FAX4\_BFT\_ISDN" identifies the service provider which comprises the FAX4/BFT and T.62 session protocol modules as well as a transport system based on the ISDN network. On the protocol levels two to four, there are implementations of HDLC LAP B: ISO/IEC 8208 and Recommendation T.70.
+
+If this service provider is selected, it is not necessary to link a transport system below it (using the *x\_bind()* function) as the protocol stack is already complete.
+
+##### I.3.7.1.2 Selection of the underlying transport system with *x\_bind()*
+
+*x\_bind()* is to be called to activate the FAX4/BFT service endpoint. The function has the following tasks:
+
+- if the service provider, which has been selected with *x\_open()*, does not comprise a transport system, link a transport system below the available protocol modules;
+- bind an address to the service endpoint.
+
+If the service provider X\_FAX4\_BFT\_ISDN has been selected in the *x\_open()* function, no transport system has to be specified in the *x\_bind()* function.
+
+The list of all service providers and transport systems available in the standard configuration (and the protocol modules they comprise) is contained in Annex B.
+
+##### I.3.7.1.3 Protocol addresses
+
+The reader should be familiar with those general concepts and the terminology, as the present part of this appendix relies on the explanations given there and just informs about the service specifics.
+
+The protocol address to be used for the BFT/FAX4 service is the NSAP address. Selectors are meaningless for the FAX4/BFT service.
+
+###### I.3.7.1.3.1 The application's own address
+
+The own address may be specified in the *own\_address* buffer of the *bind\_struct* passed as argument to the *x\_bind()* function. For a passive application it is returned in the *called\_addr* buffer of the *x\_conind()* function.
+
+For a passive application it is not supported to specify the own responding NSAP address in the *address* buffer of the *call\_struct* in the *x\_conrsp()* function, as this value is not transferred by the network.
+
+Note that specification of the application's own protocol address is completely optional. If no address information is specified, the own address is derived from system configuration information and the bound value is returned as output parameter of the *x\_bind()* function.
+
+The own address consists of the NSAP address only. The NSAP address has to comprise the local ISDN outband address, i.e. the address information used in the D-channel. The own ISDN inband address and subaddress parameters as well as the protocol selectors are meaningless in the FAX4/BFT service. If specified, they will be ignored.
+
+Table I.3-1 shows the address component which has to be specified in the *x\_bind()* call.
+
+**Table I.3-1/T.180 – Address component specified in the *x\_bind()* call**
+
+| ISDN network | Address component | Value                                                                            |
+|--------------|-------------------|----------------------------------------------------------------------------------|
+| ISDN/DSS 1   | A_OUTBAND_ADR     | A decimal digit, which is locally mapped on the Multiple Subscriber Number (MSN) |
+
+###### I.3.7.1.3.2 The address of the communication partner
+
+On the sending side, the address of the communication partner has to be specified in the *address* buffer of the *call\_struct* passed as argument to the *x\_conreq()* function. On the receiving side, the address of the communication partner is returned in the *calling\_addr* buffer of the *x\_conind()* function.
+
+The address of the communication partner comprises at least the peer's ISDN outband address. The peer's ISDN inband address and subaddress as well as the protocol selectors are meaningless for the BFT/FAX4 service.
+
+Table I.3-2 shows the address component to be used in the *address* buffer specifying the called NSAP address in an *x\_conreq()* call.
+
+**Table I.3-2/T.180 – Address component specifying the called NSAP address  
+in an *x\_conreq()* call**
+
+| ISDN network | Address component | Value                                                                                      |
+|--------------|-------------------|--------------------------------------------------------------------------------------------|
+| ISDN/DSS 1   | A_OUTBAND_ADR     | Optional the country code, optional the area code and the Multiple Subscriber Number (MSN) |
+
+##### I.3.7.1.4 Configuration of the service provider
+
+The protocol modules of the service provider behave according to configured protocol options. Protocol options are used to control the general behaviour of a protocol module (they must not be confounded with service primitive parameters). The preconfigured values of the protocol options are sufficient for the majority of communication relations.
+
+Currently, there are no options for the protocol modules of the FAX4/BFT service provider, which could be set by the XAPI function *x\_optmngmt()*.
+
+#### I.3.7.2 Connection Establishment service
+
+##### I.3.7.2.1 Service description
+
+During the connection establishment phase, two users of the same service establish a connection between each other. Both users must have already prepared an active service endpoint before they can enter the connection establishment phase.
+
+The service elements and their corresponding XAPI functions needed for FAX4/BFT Connection Establishment are described in Table I.3-3.
+
+**Table I.3-3/T.180 – Service elements and their corresponding XAPI functions for Connection Establishment**
+
+| Service element      | XAPI function | Description                                                                                                                                      |
+|----------------------|---------------|--------------------------------------------------------------------------------------------------------------------------------------------------|
+| Connect Request      | x_conreq()    | The Connect Request service is passed to the provider to request the establishment of a FAX4/BFT connection.                                     |
+| Connect Indication   | x_conind()    | The Connect Indication service is generated by the provider to indicate the request from a remote terminal to establish a FAX4/BFT connection.   |
+| Connect Response     | x_conrsp()    | The Connect Response service is passed to the provider as reaction to a previously received connect indication as positive or negative response. |
+| Connect Confirmation | x_conconf()   | The Connect Confirmation service is generated by the provider as positive or negative confirmation of a local FAX4/BFT establishment.            |
+
+##### I.3.7.2.2 Service parameters
+
+Table I.3-4 specifies the parameters of the FAX4/BFT Connection Establishment service.
+
+**Table I.3-4/T.180 – Parameters of the Connection Establishment service**
+
+| Parameter            | Connect Service |            |          |              |
+|----------------------|-----------------|------------|----------|--------------|
+|                      | Request         | Indication | Response | Confirmation |
+| X_FX4_P_OWN_TERMID   |                 | M          |          | M            |
+| X_FX4_P_FAR_TERMID   | U               | C (=)      |          | U            |
+| X_FX4_P_REASON       |                 |            |          | C            |
+| X_FX4_P_PLEASE_TOKEN |                 |            | U        | C (=)        |
+| X_FX4_P_DATE_TIME    |                 | M          |          | M            |
+
+##### I.3.7.2.3 Service parameter descriptions
+
+Tables I.3-5 to I.3-9 describe the parameters for the Connection Establishment service.
+
+**Table I.3-5/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
+|----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_FX4_P_OWN_TERMID                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
+| Type of value  | char [X_FX4_C_MAX_TERMID]                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
+| Legal values   | A sequence of characters not '\0' terminated and no longer as X_FX4_C_MAX_TERMID characters.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
+| Default value  | none                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
+| Description    | <p>The parameter indicates the own terminal identifier as described in Recommendation F.200<sup>1</sup> with a maximum length of X_FX4_C_MAX_TERMID characters. The terminal identifier consists of up to 6 parts, namely:</p> <ul style="list-style-type: none"><li>– the DNIC (Data Network Identification Code) (maximum 4 characters);</li><li>– separator "-";</li><li>– the international phone number (maximum 12 characters);</li><li>– optional an extension (maximum 4 characters);</li><li>– separator "-";</li><li>– mnemonic part (minimum 3 characters);</li></ul> <p>The sum of all parts should not exceed 24 characters.</p> |
+
+**Table I.3-6/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
+|----------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_FX4_P_FAR_TERMID                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
+| Type of value  | char [X_FX4_C_MAX_TERMID]                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
+| Legal values   | A sequence of characters not '\0' terminated and no longer as X_FX4_C_MAX_TERMID characters.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
+| Default value  | empty string                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
+| Description    | <p>The parameter indicates the remote terminal identifier as described in recommendation F.200<sup>1</sup> with a maximum length of X_FX4_C_MAX_TERMID characters. The terminal identifier consist of up to 6 parts, namely:</p> <ul style="list-style-type: none"><li>– the DNIC (Data Network Identification Code) (maximum 4 characters)</li><li>– separator "-";</li><li>– the international phone number (maximum 12 characters);</li><li>– optional an extension (maximum 4 characters);</li><li>– separator "-";</li><li>– mnemonic part (minimum 3 characters);</li></ul> <p>The sum of all parts should not exceed 24 characters.</p> |
+
+---
+
+<sup>1</sup> Recommendation F.200, *Teletex service*: This Recommendation has been withdrawn.
+
+**Table I.3-7/T.180**
+
+|                |                                                                                      |                                       |    |
+|----------------|--------------------------------------------------------------------------------------|---------------------------------------|----|
+| Parameter name | X_FX4_P_REASON                                                                       |                                       |    |
+| Type of value  | long                                                                                 |                                       |    |
+| Legal values   | X_FX4_PV_R_NO_REASON                                                                 | /* no error reason given              | */ |
+|                | X_FX4_PV_R_NO_CTX                                                                    | /* no more contexts of this type      | */ |
+|                | X_FX4_PV_R_LOCERR                                                                    | /* local terminal error               | */ |
+|                | X_FX4_PV_R_PROCERR                                                                   | /* procedure error                    | */ |
+|                | X_FX4_PV_R_LOCPROCERR                                                                | /* local terminal and procedure error | */ |
+|                | X_FX4_PV_R_SSNAC                                                                     | /* session can not be accepted        | */ |
+|                | X_FX4_PV_R_ERRMSG                                                                    | /* error message exists (text)        | */ |
+|                | X_FX4_PV_R_NOMEM                                                                     | /* no memory available                | */ |
+|                | X_FX4_PV_R_TRANSERR                                                                  | /* transmission error                 | */ |
+|                | X_FX4_PV_R_PNOERR                                                                    | /* wrong page number                  | */ |
+|                | X_FX4_PV_R_FMTERR                                                                    | /* format error                       | */ |
+|                | X_FX4_PV_R_RJCAP                                                                     | /* capabilities not supported         | */ |
+|                | X_FX4_PV_R_SVOK                                                                      | /* return code positive               | */ |
+|                | X_FX4_PV_R_SVNAV                                                                     | /* service not available              | */ |
+| Default value  | X_FX4_PV_R_NO_REASON                                                                 |                                       |    |
+| Description    | This parameter indicates the reason for a negative response or for an error request. |                                       |    |
+
+**Table I.3-8/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                      |  |  |
+|----------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--|--|
+| Parameter name | X_FX4_P_PLEASE_TOKEN                                                                                                                                                                                                                                                                                                                                                                 |  |  |
+| Type of value  | unsigned long                                                                                                                                                                                                                                                                                                                                                                        |  |  |
+| Legal values   | PV_TRUE<br>PV_FALSE                                                                                                                                                                                                                                                                                                                                                                  |  |  |
+| Default value  | PV_FALSE                                                                                                                                                                                                                                                                                                                                                                             |  |  |
+| Description    | <p>This parameter indicates a request control, which is used, if the transmission token is requested. The current owner of the transmission token may ignore this request or may give the transmission right to the passive side by issuing the X_FX4_SP_GIVE_TOKEN_Q service primitive.</p> <p>Initially, the initiator of a connection is the owner of the transmission token.</p> |  |  |
+
+**Table I.3-9/T.180**
+
+|                |                                                                                                                                                                                |  |  |
+|----------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--|--|
+| Parameter name | X_FX4_P_DATE_TIME                                                                                                                                                              |  |  |
+| Type of value  | char[X_FX4_C_MAX_DATE]                                                                                                                                                         |  |  |
+| Legal values   | A sequence of chars, not '\0' terminated, up to X_FX4_C_MAX_DATE characters long.                                                                                              |  |  |
+| Default value  | none                                                                                                                                                                           |  |  |
+| Description    | <p>The parameter indicates the connect time and has the following format:<br/>YY-MM-DD-HH:mm<br/>with YY = year<br/>MM = month<br/>DD = day<br/>HH = hour<br/>mm = minutes</p> |  |  |
+
+#### I.3.7.3 Services in the connected state
+
+The FAX4/BFT protocol module provides several services in the connected state. While the service endpoint used to access the provider is in state X\_CONNECTED these service primitives can be passed to the provider resp. retrieved from the provider with calls of *x\_snddata()*, *x\_sndsp()* resp. *x\_rcvdata()*, *x\_rcvsp()*.
+
+The data transfer works in a so called TWA (Two-Way Alternate) mode. This means the initiator and responder act in a sink/source relationship, in which only one of them may send data at a time. The responder may signal in some responses [*x\_conrsp()*, X\_FX4\_SP\_EOP\_P, X\_FX4\_SP\_EOD\_P] a request control to indicate that the responder has information to transmit. The owner of the Data Token, which is the initiator of the connection when entering the X\_CONNECTED state, may then give control to the responder by issuing the X\_FX4\_SP\_GIVE\_TOKEN\_Q service primitive. If the token was exchanged, it must be exchanged again before an orderly release can be initiated. This means in general:
+
+- the initiator of the connection owns the Data Token;
+- the responder may ask for the token (X\_FX4\_PV\_PLEASE\_TOKEN);
+- the initiator may hand over the Data Token by the service primitive X\_FX4\_SP\_GIVE\_TOKEN\_Q;
+- if the responder has got the Data Token, he must return the Data Token to the initiator by issuing the service primitive X\_FX4\_SP\_GIVE\_TOKEN\_Q before releasing the connection;
+- only the initiator can initiate an orderly release request.
+
+##### I.3.7.3.1 Start of Document service
+
+###### I.3.7.3.1.1 Service description
+
+The Start of Document service indicates the start of the document to the receiver of the document. It also indicates the start of the first page.
+
+The service elements and their corresponding XAPI functions needed for the Start of Document are described in Table I.3-10.
+
+**Table I.3-10/T.180 – Service elements and their corresponding XAPI functions for Start of Document**
+
+| Service element              | XAPI function    | Service element identifier | Description                                                                                                                                 |
+|------------------------------|------------------|----------------------------|---------------------------------------------------------------------------------------------------------------------------------------------|
+| Start of Document Request    | <i>x_sndsp()</i> | X_FX4_SP_SOD_Q             | The Start of Document Request is passed to the provider to request the start of the document transmission from the active side.             |
+| Start of Document Indication | <i>x_rcvsp()</i> | X_FX4_SP_SOD_I             | The Start of Document Indication is generated by the provider to indicate that the reception of a document has started by the passive side. |
+
+**Table I.3-10/T.180 – Service elements and their corresponding XAPI functions for Start of Document (*concluded*)**
+
+| Service element                | XAPI function | Service element identifier | Description                                                                                                                                                                                                     |
+|--------------------------------|---------------|----------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Start of Document Confirmation | x_revsp()     | X_FX4_SP_SOD_C             | The Start of Document confirmation is sent to the sender of the Start of Document Request as acknowledgement of the command. The user should examine the parameters to check if the capabilities were accepted. |
+
+###### I.3.7.3.1.2 Service parameters
+
+Table I.3-11 specifies the parameters of the Start of Document service.
+
+**Table I.3-11/T.180 – Parameters of the Start of Document service**
+
+| Parameter                                                                                                                                                                                                                                                                                                            | Start of Document service |            |              |
+|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------|------------|--------------|
+|                                                                                                                                                                                                                                                                                                                      | Request                   | Indication | Confirmation |
+| X_FX4_P_DOC_TYPE                                                                                                                                                                                                                                                                                                     | M                         | M (=)      |              |
+| X_FX4_P_BFT_FNAME                                                                                                                                                                                                                                                                                                    | MC <sup>a)</sup>          | C (=)      |              |
+| X_FX4_P_BFT_PATH                                                                                                                                                                                                                                                                                                     | MC <sup>a)</sup>          | C (=)      |              |
+| X_FX4_P_BFT_COMPR                                                                                                                                                                                                                                                                                                    | MC <sup>a)</sup>          | C (=)      |              |
+| X_FX4_P_FAX_DENSITY                                                                                                                                                                                                                                                                                                  | UC <sup>b)</sup>          | C (=)      | C (=)        |
+| X_FX4_P_FAX_COMPRESSION                                                                                                                                                                                                                                                                                              | UC <sup>b)</sup>          | C (=)      | C (=)        |
+| X_FX4_P_FAX_DIMENSION                                                                                                                                                                                                                                                                                                | UC <sup>b)</sup>          | C (=)      | C (=)        |
+| X_FX4_P_DOCREF                                                                                                                                                                                                                                                                                                       | M                         | M (=)      |              |
+| X_FX4_P_ACCEPT                                                                                                                                                                                                                                                                                                       |                           |            | M            |
+| X_FX4_P_REASON                                                                                                                                                                                                                                                                                                       |                           |            | M            |
+| <sup>a)</sup> Presence depends on the value of the parameter X_FX4_P_DOC_TYPE. If the value of X_FX4_P_DOC_TYPE is X_FX4_PV_FAX, this parameter is mandatory.<br><sup>b)</sup> Presence depends on the value of the parameter X_FX4_P_DOC_TYPE. If set to X_FX4_PV_BFT, presence of this parameter is a user option. |                           |            |              |
+
+###### I.3.7.3.1.3 Service parameter descriptions
+
+Tables I.3-12 to I.3-21 describe the parameters for the Start of Document service.
+
+**Table I.3-12/T.180**
+
+|                |                                                                                                                                                                                                                                                     |
+|----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_FX4_P_DOC_TYPE                                                                                                                                                                                                                                    |
+| Type of value  | long                                                                                                                                                                                                                                                |
+| Legal values   | X_FX4_PV_FAX<br>X_FX4_PV_BFT                                                                                                                                                                                                                        |
+| Default value  | none                                                                                                                                                                                                                                                |
+| Description    | This parameter indicates the type of document which should be transmitted. The value could be either X_FX4_PV_FAX or X_FX4_PV_BFT. In case of X_FX4_PV_FAX, the document content has to contain T.6 encoded data, or any other type of binary data. |
+
+**Table I.3-13/T.180**
+
+|                |                                                                                                                                                                  |
+|----------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_FX4_P_BFT_FNAME                                                                                                                                                |
+| Type of value  | char [X_FX4_C_MAX_NAME]                                                                                                                                          |
+| Legal values   | Any sequence of characters not containing '\0'. The length is restricted to X_FX4_C_MAX_NAME.                                                                    |
+| Default value  | none                                                                                                                                                             |
+| Description    | This parameter indicates the file name of the binary file which should be transmitted. This parameter may only be used, if the X_FX4_P_DOC_TYPE is X_FX4_PV_BFT. |
+
+**Table I.3-14/T.180**
+
+|                |                                                                                                                                                                  |
+|----------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_FX4_P_BFT_PATH                                                                                                                                                 |
+| Type of value  | char [X_FX4_C_MAX_PATH]                                                                                                                                          |
+| Legal values   | Any sequence of characters not containing '\0'. The length is restricted to X_FX4_C_MAX_PATH.                                                                    |
+| Default value  | none                                                                                                                                                             |
+| Description    | This parameter indicates the path name of the binary file which should be transmitted. This parameter may only be used, if the X_FX4_P_DOC_TYPE is X_FX4_PV_BFT. |
+
+**Table I.3-15/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                                                          |
+|----------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_FX4_P_BFT_COMPR                                                                                                                                                                                                                                                                                                                                                                                                                        |
+| Type of value  | char [X_FX4_C_MAX_NAME]                                                                                                                                                                                                                                                                                                                                                                                                                  |
+| Legal values   | Any sequence of characters not containing '\0'. The length is restricted to X_FX4_C_MAX_NAME.                                                                                                                                                                                                                                                                                                                                            |
+| Default value  | none                                                                                                                                                                                                                                                                                                                                                                                                                                     |
+| Description    | <p>This parameter indicates the compression mode in which the binary file is transmitted.</p> <p>This parameter may only be used, if the X_FX4_P_DOC_TYPE is X_FX4_PV_BFT.</p> <p>This parameter should be omitted if the file is not compressed.</p> <p>Since Recommendation T.434 does not make any restriction on the contents of this attribute, the sender and receiver agree upon a string for the used compression algorithm.</p> |
+
+**Table I.3-16/T.180**
+
+|                |                                                                                                                                                                              |
+|----------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_FX4_P_FAX_DENSITY                                                                                                                                                          |
+| Type of value  | unsigned long                                                                                                                                                                |
+| Legal values   | <p>One of the following values:</p> <p>X_FX4_PV_DENS_200;</p> <p>X_FX4_PV_DENS_240;</p> <p>X_FX4_PV_DENS_300;</p> <p>X_FX4_PV_DENS_400.</p>                                  |
+| Default value  | X_FX4_PV_DENS_200                                                                                                                                                            |
+| Description    | <p>This parameter indicates the density of the FAX4 document which should be transmitted.</p> <p>This parameter may only be used if the X_FX4_P_DOC_TYPE = X_FX4_PV_FAX.</p> |
+
+**Table I.3-17/T.180**
+
+|                |                                                                                                                                                                                                                            |
+|----------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_FX4_P_FAX_DIMENSION                                                                                                                                                                                                      |
+| Type of value  | unsigned long                                                                                                                                                                                                              |
+| Legal values   | <p>X_FX4_PV_DIM_A4</p> <p>X_FX4_PV_DIM_B4</p> <p>X_FX4_PV_DIM_A3</p> <p>X_FX4_PV_DIM_AM_LETTER</p> <p>X_FX4_PV_DIM_AM_LEGAL</p> <p>X_FX4_PV_DIM_AM_LEDGER</p> <p>X_FX4_PV_DIM_JAP_LETTER</p> <p>X_FX4_PV_DIM_JAP_LEGAL</p> |
+| Default value  | X_FX4_PV_DIM_A4.                                                                                                                                                                                                           |
+| Description    | <p>This parameter indicates the density of the FAX4 document which should be transmitted.</p> <p>This parameter may only be used if the X_FX4_P_DOC_TYPE is X_FX4_PV_FAX.</p>                                              |
+
+**Table I.3-18/T.180**
+
+|                |                                                                                                                                                                                  |
+|----------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_FAX4_P_FAX_COMPRESSION                                                                                                                                                         |
+| Type of value  | unsigned long                                                                                                                                                                    |
+| Legal values   | PV_TRUE<br>PV_FALSE                                                                                                                                                              |
+| Default value  | PV_TRUE                                                                                                                                                                          |
+| Description    | This parameter indicates the T.6 compression mode within the FAX4 document which should be transmitted. This parameter may only be used if the X_FX4_P_DOC_TYPE is X_FX4_PV_FAX. |
+
+**Table I.3-19/T.180**
+
+|                |                                                                                                                                                                                                                 |
+|----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_FX4_P_DOCREF                                                                                                                                                                                                  |
+| Type of value  | char [X_FX4_C_MAX_DOC_REF]                                                                                                                                                                                      |
+| Legal values   | Any sequence of the characters '0', '1', '2', ..., '9' not containing '\0'. The length is restricted to X_FX4_C_MAX_DOC_REF.                                                                                    |
+| Default value  | none                                                                                                                                                                                                            |
+| Description    | This parameter indicates the document reference number. This number should start by 1 and should be incremented for every document, which is transmitted in the same connection. Leading zeros will be ignored. |
+
+**Table I.3-20/T.180**
+
+|                |                                                                                                                               |
+|----------------|-------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_FX4_P_ACCEPT                                                                                                                |
+| Type of value  | unsigned long                                                                                                                 |
+| Legal values   | PV_TRUE<br>PV_FALSE                                                                                                           |
+| Default value  | PV_TRUE                                                                                                                       |
+| Description    | This parameter indicates if a Connect Request or Start of Document Request was accepted (= PV_TRUE) or rejected (= PV_FALSE). |
+
+**Table I.3-21/T.180**
+
+|                |                                                                                      |                                       |    |
+|----------------|--------------------------------------------------------------------------------------|---------------------------------------|----|
+| Parameter name | X_FX4_P_REASON                                                                       |                                       |    |
+| Type of value  | long                                                                                 |                                       |    |
+| Legal values   | X_FX4_PV_R_NO_REASON                                                                 | /* no error reason given              | */ |
+|                | X_FX4_PV_R_NO_CTX                                                                    | /* no more contexts of this type      | */ |
+|                | X_FX4_PV_R_LOCERR                                                                    | /* local terminal error               | */ |
+|                | X_FX4_PV_R_PROCERR                                                                   | /* procedure error                    | */ |
+|                | X_FX4_PV_R_LOCPROCERR                                                                | /* local terminal and procedure error | */ |
+|                | X_FX4_PV_R_SSNAC                                                                     | /* session can not be accepted        | */ |
+|                | X_FX4_PV_R_ERRMSG                                                                    | /* error message exists (text)        | */ |
+|                | X_FX4_PV_R_NOMEM                                                                     | /* no memory available                | */ |
+|                | X_FX4_PV_R_TRANSERR                                                                  | /* transmission error                 | */ |
+|                | X_FX4_PV_R_PNOERR                                                                    | /* wrong page number                  | */ |
+|                | X_FX4_PV_R_FMTERR                                                                    | /* format error                       | */ |
+|                | X_FX4_PV_R_RJCAP                                                                     | /* capabilities not supported         | */ |
+|                | X_FX4_PV_R_SVOK                                                                      | /* return code positive               | */ |
+|                | X_FX4_PV_R_SVNAV                                                                     | /* service not available              | */ |
+| Default value  | X_FX4_PV_R_NO_REASON                                                                 |                                       |    |
+| Description    | This parameter indicates the reason for a negative response or for an error request. |                                       |    |
+
+##### I.3.7.3.2 Data Transfer service
+
+###### I.3.7.3.2.1 Service description
+
+The Data Transfer service allows both FAX4/BFT service users to transfer documents alternately.
+
+The service elements and their corresponding XAPI functions needed for Data Transfer are described in Table I.3-22.
+
+**Table I.3-22/T.180 – Service elements and their corresponding XAPI functions for Data Transfer**
+
+| Service element | XAPI function | Description                                                                                                       |
+|-----------------|---------------|-------------------------------------------------------------------------------------------------------------------|
+| Data Request    | x_snddata()   | The Data Request service is passed to the provider to transmit real data (T.6 data or binary data).               |
+| Data Indication | x_rcvdata()   | The Data Indication service is generated by the provider to indicate the received data (T.6 data or binary data). |
+
+###### I.3.7.3.2.2 Service parameter
+
+Table I.3-23 specifies the parameter of the Data Transfer service.
+
+**Table I.3-23/T.180 – Parameters of the Data Transfer service**
+
+| Parameter        | Data Transfer service |            |
+|------------------|-----------------------|------------|
+|                  | Request               | Indication |
+| X_FX4_P_BLOCK_NR | M                     | M          |
+
+###### I.3.7.3.2.3 Service parameter description
+
+Table I.3-24 describes the parameter for the Data Transfer service.
+
+**Table I.3-24/T.180**
+
+|                |                                                                       |
+|----------------|-----------------------------------------------------------------------|
+| Parameter name | X_FX4_P_BLOCK_NR                                                      |
+| Type of value  | unsigned long                                                         |
+| Legal values   | any number                                                            |
+| Default value  | none                                                                  |
+| Description    | The parameter indicates the current block number in the current page. |
+
+##### I.3.7.3.3 Page Boundary service
+
+###### I.3.7.3.3.1 Service description
+
+The FAX4/BFT service uses a checkpoint mechanism in the document transfer. This means each page (or checkpoint in BFT mode) is confirmed by the receiver.
+
+The service elements and their corresponding XAPI functions needed for the Page Boundary service are described in Table I.3-25.
+
+**Table I.3-25/T.180 – Service elements and their corresponding XAPI functions for Page Boundary**
+
+| Service element          | XAPI function | Service element identifier | Description                                                                                                                                                                                 |
+|--------------------------|---------------|----------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| End of Page Request      | x_sndsp()     | X_FX4_SP_EOP_Q             | The End of Page Request is passed to the provider to request the checkpointing from the active side.                                                                                        |
+| End of Page Indication   | x_rcvsp()     | X_FX4_SP_EOP_I             | The End of Page Indication is generated by the provider to indicate the reception of a checkpoint by the passive side.                                                                      |
+| End of Page Response     | x_sndsp()     | X_FX4_SP_EOP_P             | The End of Page Response is passed to the provider to confirm the checkpoint from the active side.                                                                                          |
+| End of Page Confirmation | x_rcvsp()     | X_FX4_SP_EOP_C             | The End of Page Confirmation is given to the sender of the End of Page Request as acknowledgement of the command. The user should examine the parameters to check if the page was accepted. |
+
+###### I.3.7.3.3.2 Service parameters
+
+Table I.3-26 specifies the parameters of the Page Boundary service.
+
+**Table I.3-26/T.180 – Parameters of the Page Boundary service**
+
+| Parameter            | Page Boundary service |            |          |              |
+|----------------------|-----------------------|------------|----------|--------------|
+|                      | Request               | Indication | Response | Confirmation |
+| X_FX4_P_PAGE_NR      | M                     | M (=)      | M (=)    | M (=)        |
+| X_FX4_P_REC_JEOP     |                       |            | U        | C (=)        |
+| X_FX4_P_ACCEPT       |                       |            | U        | C (=)        |
+| X_FX4_P_REASON       |                       |            | U        | C (=)        |
+| X_FX4_P_PLEASE_TOKEN |                       |            | U        | C (=)        |
+
+##### **I.3.7.3.3 Service parameter descriptions**
+
+Tables I.3-27 to I.3-31 describe the parameters for the Page Boundary service.
+
+**Table I.3-27/T.180**
+
+|                |                                                   |
+|----------------|---------------------------------------------------|
+| Parameter name | X_FX4_P_PAGE_NR                                   |
+| Type of value  | unsigned long                                     |
+| Legal values   | any number greater than zero                      |
+| Default value  | none                                              |
+| Description    | This parameter indicates the current page number. |
+
+**Table I.3-28/T.180**
+
+|                |                                                                                                                                                     |
+|----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_FX4_P_REC_JEOP                                                                                                                                    |
+| Type of value  | unsigned long                                                                                                                                       |
+| Legal values   | PV_TRUE<br>PV_FALSE                                                                                                                                 |
+| Default value  | PV_FALSE                                                                                                                                            |
+| Description    | This parameter indicates if the receiver can not receive more pages. If this parameter is set to PV_TRUE, the sender should abort the transmission. |
+
+**Table I.3-29/T.180**
+
+|                |                                                                                                                                                    |
+|----------------|----------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_FX4_P_ACCEPT                                                                                                                                     |
+| Type of value  | unsigned long                                                                                                                                      |
+| Legal values   | PV_TRUE<br>PV_FALSE                                                                                                                                |
+| Default value  | PV_TRUE                                                                                                                                            |
+| Description    | This parameter indicates if a Connect Request, Start of Document Request or End of Page Request was accepted (= PV_TRUE) or rejected (= PV_FALSE). |
+
+**Table I.3-30/T.180**
+
+|                |                                                                              |                          |    |
+|----------------|------------------------------------------------------------------------------|--------------------------|----|
+| Parameter name | X_FX4_P_REASON                                                               |                          |    |
+| Type of value  | long                                                                         |                          |    |
+| Legal values   | X_FX4_PV_R_NO_REASON                                                         | /* no error reason given | */ |
+|                | X_FX4_PV_R_LOCERR                                                            | /* local terminal error  | */ |
+|                | X_FX4_PV_R_PROCERR                                                           | /* procedure error       | */ |
+|                | X_FX4_PV_R_NOMEM                                                             | /* no memory available   | */ |
+|                | X_FX4_PV_R_TRANSERR                                                          | /* transmission error    | */ |
+|                | X_FX4_PV_R_PNOERR                                                            | /* wrong page number     | */ |
+|                | X_FX4_PV_R_FMTERR                                                            | /* format error          | */ |
+| Default value  | X_FX4_PV_R_NO_REASON                                                         |                          |    |
+| Description    | This parameter indicates the reason of a negative response or error request. |                          |    |
+
+**Table I.3-31/T.180**
+
+|                |                                                                                                                                                                                                                                                                                       |  |  |
+|----------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--|--|
+| Parameter name | X_FX4_P_PLEASE_TOKEN                                                                                                                                                                                                                                                                  |  |  |
+| Type of value  | unsigned long                                                                                                                                                                                                                                                                         |  |  |
+| Legal values   | PV_TRUE<br>PV_FALSE                                                                                                                                                                                                                                                                   |  |  |
+| Default value  | PV_FALSE                                                                                                                                                                                                                                                                              |  |  |
+| Description    | This parameter indicates a request control which is used if the transmission token is requested. The current owner of the transmission token may ignore this request or may give the transmission request to the passive side by issuing the X_FX4_SP_GIVE_TOKEN_Q service primitive. |  |  |
+
+##### **I.3.7.3.4 End of document service**
+
+###### **I.3.7.3.4.1 Service description**
+
+The FAX4/BFT service uses a checkpoint mechanism in the document transfer. This means each page (or checkpoint in BFT mode) is confirmed from the receiver. If the last page was transmitted, the End of Document service is used instead of End of Page.
+
+The service elements and their corresponding XAPI functions needed for the End of Document service are described in Table I.3-32.
+
+**Table I.3-32/T.180 – Service elements and their corresponding XAPI functions for End of Document**
+
+| Service element              | XAPI function | Service element identifier | Description                                                                                                                        |
+|------------------------------|---------------|----------------------------|------------------------------------------------------------------------------------------------------------------------------------|
+| End of Document Request      | x_sndsp()     | X_FX4_SP_EOD_Q             | The End of Document Request is passed to the provider to request the final checkpoint from the active side.                        |
+| End of Document Indication   | x_rcvsp()     | X_FX4_SP_EOD_I             | The End of Document Indication is generated by the provider to indicate the reception of the final checkpoint by the passive side. |
+| End of Document Response     | x_sndsp()     | X_FX4_SP_EOD_P             | The End of Document Response is passed to the provider to confirm the final checkpoint from the active side.                       |
+| End of Document Confirmation | x_rcvsp()     | X_FX4_SP_EOD_C             | The End of Document Confirmation is sent to the originator of the Start of Document Request as acknowledgement of the command.     |
+
+###### I.3.7.3.4.2 Service parameters
+
+Table I.3-33 specifies the parameters of the End of Document service.
+
+**Table I.3-33/T.180 – Parameters of the End of Document service**
+
+| Parameter            | End of Document service |            |          |              |
+|----------------------|-------------------------|------------|----------|--------------|
+|                      | Request                 | Indication | Response | Confirmation |
+| X_FX4_P_PAGE_NR      | M                       | M (=)      | M (=)    | M (=)        |
+| X_FX4_P_PLEASE_TOKEN |                         |            | U        | C (=)        |
+
+###### I.3.7.3.4.3 Service parameter descriptions
+
+Tables I.3-34 and I.3-35 describe the parameters for the End of Document service.
+
+**Table I.3-34/T.180**
+
+|                |                                                   |
+|----------------|---------------------------------------------------|
+| Parameter name | X_FX4_P_PAGE_NR                                   |
+| Type of value  | unsigned long                                     |
+| Legal values   | any number greater than zero                      |
+| Default value  | none                                              |
+| Description    | This parameter indicates the current page number. |
+
+**Table I.3-35/T.180**
+
+|                |                                                                                                                                                                                                                                                                                       |
+|----------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_FX4_P_PLEASE_TOKEN                                                                                                                                                                                                                                                                  |
+| Type of value  | unsigned long                                                                                                                                                                                                                                                                         |
+| Legal values   | PV_TRUE<br>PV_FALSE                                                                                                                                                                                                                                                                   |
+| Default value  | PV_FALSE                                                                                                                                                                                                                                                                              |
+| Description    | This parameter indicates a request control which is used if the transmission token is requested. The current owner of the transmission token may ignore this request or may give the transmission request to the passive side by issuing the X_FX4_SP_GIVE_TOKEN_Q service primitive. |
+
+##### **I.3.7.3.5 Resynchronize document service**
+
+###### **I.3.7.3.5.1 Service description**
+
+The FAX4/BFT service uses a resynchronization mechanism for an abnormal end of a document transfer. This means the initiator of the document transfer indicates the passive side the abnormal end of the document transfer phase; this indication is passed to the XAPI user.
+
+The service elements and their corresponding XAPI functions needed for the Resynchronize Document service are described in Table I.3-36.
+
+**Table I.3-36/T.180 – Service elements and their corresponding XAPI functions for Resynchronize Document**
+
+| Service element                   | XAPI function | Service element identifier | Description                                                                                          |
+|-----------------------------------|---------------|----------------------------|------------------------------------------------------------------------------------------------------|
+| Resynchronize Document Indication | x_rcvsp()     | X_FX4_SP_RSYN_I            | The Resynchronize Document Indication is an indication of the abnormal end of the document transfer. |
+
+###### **I.3.7.3.5.2 Service parameter**
+
+Table I.3-37 specifies the parameter of the Resynchronize Document service.
+
+**Table I.3-37/T.180 – Parameters of the Resynchronize Document service**
+
+| Parameter      | Resynchronize Document service |
+|----------------|--------------------------------|
+|                | Indication                     |
+| X_FX4_P_REASON | C                              |
+
+###### I.3.7.3.5.3 Service parameter description
+
+Table I.3-38 describes the parameter for the Resynchronize Document service.
+
+**Table I.3-38/T.180**
+
+|                |                                                                           |                          |    |
+|----------------|---------------------------------------------------------------------------|--------------------------|----|
+| Parameter name | X_FX4_P_REASON                                                            |                          |    |
+| Type of value  | long                                                                      |                          |    |
+| Legal values   | X_FX4_PV_R_NO_REASON                                                      | /* no error reason given | */ |
+|                | X_FX4_PV_R_LOCERR                                                         | /* local terminal error  | */ |
+|                | X_FX4_PV_R_PROCERR                                                        | /* procedure error       | */ |
+|                | X_FX4_PV_R_NOMEM                                                          | /* no memory available   | */ |
+|                | X_FX4_PV_R_TRANSERR                                                       | /* transmission error    | */ |
+|                | X_FX4_PV_R_PNOERR                                                         | /* wrong page number     | */ |
+|                | X_FX4_PV_R_FMTERR                                                         | /* format error          | */ |
+| Default value  | X_FX4_PV_R_NO_REASON                                                      |                          |    |
+| Description    | This parameter indicates the reason for an abnormal ending of a document. |                          |    |
+
+##### I.3.7.3.6 Give Token service
+
+###### I.3.7.3.6.1 Service description
+
+The data transfer works in a so called TWA (Two-Way Alternate) mode. This means the initiator and responder acts in a sink/source relationship, in which only one of them may send data at a time. The responder may signal in some responses [x\_conrsp(), X\_FX4\_SP\_EOP\_P, X\_FX4\_SP\_EOD\_P] a request control to indicate that the responder has information to transmit. The owner of the Data Token may then give control to the responder by issuing the X\_FX4\_SP\_GIVE\_TOKEN\_Q service primitive. If the token was exchanged, it must be exchanged again before an orderly release can be initiated. This means in general:
+
+- the initiator of the connection owns the Data Token;
+- the responder may ask for the token (X\_FX4\_PV\_PLEASE\_TOKEN);
+- the initiator may hand over the Data Token by the service primitive X\_FX4\_SP\_GIVE\_TOKEN\_Q;
+- if the responder has received the Data Token, he must return the Data Token to the initiator by issuing the service primitive X\_FX4\_SP\_GIVE\_TOKEN\_Q before releasing the connection;
+- only the initiator can initiate an orderly release request.
+
+The service elements and their corresponding XAPI functions needed for the Give Token service are described in Table I.3-39.
+
+**Table I.3-39/T.180 – Service elements and their corresponding XAPI functions for Give Token**
+
+| Service element       | XAPI function          | Service element identifier         | Description                                                                                                                                                                                                                             |
+|-----------------------|------------------------|------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Give Token Request    | <code>x_sndsp()</code> | <code>X_FX4_SP_GIVE_TOKEN_Q</code> | The Give Token Request is passed to the provider to hand over the right for transmitting data from the active side to the passive side. The active side now becomes the passive side and the passive side now becomes the active side.  |
+| Give Token Indication | <code>x_revsp()</code> | <code>X_FX4_SP_GIVE_TOKEN_I</code> | The Give Token Indication is generated by the provider to indicate that the remote side has handed over the right for transmitting data. The active side now becomes the passive side and the passive side now becomes the active side. |
+
+###### **I.3.7.3.6.2 Service parameters**
+
+There are no service parameters defined for the Give Token service.
+
+##### **I.3.7.3.7 States in the connected state**
+
+In the FAX4/BFT protocol the data transfer is managed in ten states, which may be entered by the service provider while the endpoint used for access is in state `X_CONNECTED`:
+
+States which are entered, if the service provider is the initiator (active side) (see Figure I.3-2):
+
+- state 10      This is the initial state. It is entered when the service endpoint enters state `X_CONNECTED`. Orderly release may be started from this state only. In all other data transfer states abortive disconnection has to be used to end the communication. This is also the only state from which an `X_FX4_SP_GIVE_TOKEN_Q` can be issued.
+- state 11      This state is entered when an `X_FX4_SP_SOD_Q` was sent and an `X_FX4_SP_SOD_C` is pending.
+- state 12      This state is entered when a positive `X_FX4_SP_SOD_C` was received. The service user is now able to transmit data with `x_snddata()`.
+- state 13      This state is entered after sending data with `x_snddata()`. In this state, the user may send more data (`x_snddata()`), send `X_FX4_SP_EOP_Q` to indicate a page boundary, or `X_FX4_SP_EOD_Q` to indicate the end of the document.  
+This state is entered, when an `X_FX4_SP_EOP_C` was received, which indicates that the checkpoint is confirmed.
+- state 14      This state is entered when an `X_FX4_SP_EOP_Q` was sent and an `X_FX4_SP_EOP_C` is pending.
+- state 15      This state is entered when an `X_FX4_SP_EOD_Q` was received and an `X_FX4_SP_EOD_C` is pending.
+
+![State transition diagram for data transfer states in active mode. The diagram shows states 10, 11, 12, 13, 14, 15, and 20. Transitions are labeled with events like X_FX4_SP_GIVE_TOKEN_Q, X_FX4_SP_SOD_Q, X_FX4_SP_SOD_C (accepted), X_DATA_Q, X_FX4_SP_EOP_Q, X_FX4_SP_EOP_C, X_FX4_SP_EOD_Q, and X_FX4_SP_EOD_C. A large curved arrow loops from state 15 back to state 10.](33cbd34b2ff74e39d12fae4db73f5b41_img.jpg)
+
+```
+
+graph TD
+    state20([state 20]) -- "X_FX4_SP_GIVE_TOKEN_Q" --> state10([state 10])
+    state10 -- "X_FX4_SP_SOD_Q" --> state11([state 11])
+    state11 -- "X_FX4_SP_SOD_C (accepted)" --> state12([state 12])
+    state12 -- "X_DATA_Q" --> state13([state 13])
+    state13 -- "X_DATA_Q" --> state13
+    state13 -- "X_FX4_SP_EOP_Q" --> state14([state 14])
+    state14 -- "X_FX4_SP_EOP_C" --> state13
+    state14 -- "X_FX4_SP_EOD_Q" --> state15([state 15])
+    state15 -- "X_FX4_SP_EOD_C" --> state10
+  
+```
+
+T0827270-97
+
+State transition diagram for data transfer states in active mode. The diagram shows states 10, 11, 12, 13, 14, 15, and 20. Transitions are labeled with events like X\_FX4\_SP\_GIVE\_TOKEN\_Q, X\_FX4\_SP\_SOD\_Q, X\_FX4\_SP\_SOD\_C (accepted), X\_DATA\_Q, X\_FX4\_SP\_EOP\_Q, X\_FX4\_SP\_EOP\_C, X\_FX4\_SP\_EOD\_Q, and X\_FX4\_SP\_EOD\_C. A large curved arrow loops from state 15 back to state 10.
+
+**Figure I.3-2/T.180 – Data transfer states in active mode**
+
+States which are entered, if the service provider is the responder (receiving side) (see Figure I.3-3):
+
+state 20 This is the initial state. It is entered when the service endpoint enters state X\_CONNECTED. Orderly release may be started from this state only. In all other data transfer states, abortive disconnection has to be used to end the communication. If a X\_FX4\_SP\_GIVE\_TOKEN\_I was received, the automaton enters the state 10. Before the connection can be orderly released, the token must be returned by
+
+X\_FX4\_GIVE\_TOKEN\_Q to the initiator side. If an X\_FX4\_SP\_RSYN\_I was received, the automaton will stay in this state.
+
+state 21 This state is entered when an X\_FX4\_SP\_SOD\_I was received. The service user may now receive Data with the function *x\_rcvdata()*. If an X\_FX4\_SP\_RSYN\_I was received, the automaton enters the state 20.
+
+state 22 This state is entered when an X\_FX4\_SP\_EOP\_I was received, which indicates the end of the current page (checkpoint). The service user has now to confirm this page by sending an X\_FX4\_SP\_EOP\_P.
+
+state 23 This state is entered when an X\_FX4\_SP\_EOD\_I was received, which indicates the successfully transmission of the whole document. The service user has now to confirm the end of the document with X\_FX4\_SP\_EOD\_P.
+
+The user may ask for the transmission token (please token request), by setting the parameter X\_FX4\_P\_PLEASE\_TOKEN equal PV\_TRUE in the service primitives *x\_conrsp()*, X\_FX4\_SP\_EOP\_P or X\_FX4\_SP\_EOD\_P. The active side may then hand over the transmission token by issuing the service primitive X\_FX4\_SP\_GIVE\_TOKEN\_Q.
+
+![State transition diagram for data transfer states in passive mode. The diagram shows four states: state 10, state 20, state 21, and state 23. Transitions are labeled with service primitives. State 20 has a self-loop for X_FX4_SP_RSYN_I and a transition to state 10 for X_FX4_SP_GIVE_TOKEN_I. State 21 has a self-loop for X_DATA_I and a transition to state 20 for X_FX4_SP_RSYN_I. State 23 has a transition to state 20 for X_FX4_SP_RSYN_I and a transition to state 21 for X_FX4_SP_EOP_I. State 21 has a transition to state 23 for X_FX4_SP_EOP_I. State 23 has a transition to state 21 for X_FX4_SP_EOP_P and a transition to state 20 for X_FX4_SP_EOD_I. State 20 has a transition to state 23 for X_FX4_SP_EOD_P. State 23 has a transition to state 20 for X_FX4_SP_EOD_P. The diagram is labeled T0827280-97.](34b381406f073080ef510a32772b2612_img.jpg)
+
+```
+
+graph TD
+    state10([state 10])
+    state20([state 20])
+    state21([state 21])
+    state23([state 23])
+
+    state20 -- "X_FX4_SP_RSYN_I" --> state20
+    state20 -- "X_FX4_SP_GIVE_TOKEN_I" --> state10
+    state21 -- "X_DATA_I" --> state21
+    state21 -- "X_FX4_SP_RSYN_I" --> state20
+    state23 -- "X_FX4_SP_RSYN_I" --> state20
+    state21 -- "X_FX4_SP_EOP_I" --> state23
+    state23 -- "X_FX4_SP_EOP_P" --> state21
+    state23 -- "X_FX4_SP_EOD_I" --> state20
+    state20 -- "X_FX4_SP_EOD_P" --> state23
+    state23 -- "X_FX4_SP_EOD_P" --> state20
+  
+```
+
+T0827280-97
+
+State transition diagram for data transfer states in passive mode. The diagram shows four states: state 10, state 20, state 21, and state 23. Transitions are labeled with service primitives. State 20 has a self-loop for X\_FX4\_SP\_RSYN\_I and a transition to state 10 for X\_FX4\_SP\_GIVE\_TOKEN\_I. State 21 has a self-loop for X\_DATA\_I and a transition to state 20 for X\_FX4\_SP\_RSYN\_I. State 23 has a transition to state 20 for X\_FX4\_SP\_RSYN\_I and a transition to state 21 for X\_FX4\_SP\_EOP\_I. State 21 has a transition to state 23 for X\_FX4\_SP\_EOP\_I. State 23 has a transition to state 21 for X\_FX4\_SP\_EOP\_P and a transition to state 20 for X\_FX4\_SP\_EOD\_I. State 20 has a transition to state 23 for X\_FX4\_SP\_EOD\_P. State 23 has a transition to state 20 for X\_FX4\_SP\_EOD\_P. The diagram is labeled T0827280-97.
+
+**Figure I.3-3/T.180 – Data transfer states in passive mode**
+
+#### **I.3.7.4 Connection Release service**
+
+##### **I.3.7.4.1 Service description**
+
+The orderly release service allows FAX4/BFT service users to release the connection in an orderly manner. The release may only be requested by the side who has initiated the connection and who
+
+owns the Data Token. The orderly release can not be requested during the document transfer phase (between X\_FX4\_SP\_SOD\_Q and X\_FX4\_SP\_EOD\_Q).
+
+The service elements and their corresponding XAPI functions needed for Connection Release are described in Table I.3-40.
+
+**Table I.3-40/T.180 – Service elements and their corresponding XAPI functions for Connection Release**
+
+| Service element      | XAPI function | Description                                                                                                                                                                                           |
+|----------------------|---------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Release Request      | x_relreq()    | The Release Request is passed to the provider to request a normal FAX4/BFT connection release.                                                                                                        |
+| Release Indication   | x_relind()    | The Release Indication is generated by the provider to indicate the orderly release of a FAX4/BFT connection by the remote side.                                                                      |
+| Release Response     | x_relrsp()    | The Release Response is passed to the provider as reaction to a previously received release indication as positive response.                                                                          |
+| Release Confirmation | x_relconf()   | The Release Confirmation is generated by the provider as positive confirmation of a normal FAX4/BFT release.                                                                                          |
+| End Indication       | x_rcvend()    | The End Indication is generated by the provider to indicate that the service provider is ready to establish a new connection. In addition it contains some information about the released connection. |
+
+##### I.3.7.4.2 Service parameters
+
+Table I.3-41 specifies the parameters of the Connection Release service.
+
+**Table I.3-41/T.180 – Parameters of the Connection Release service**
+
+| Parameter       | Connection Release service |            |          |              |                |
+|-----------------|----------------------------|------------|----------|--------------|----------------|
+|                 | Request                    | Indication | Response | Confirmation | End Indication |
+| X_P_CONN_TIME   |                            |            |          |              | M              |
+| X_P_DISC_TIME   |                            |            |          |              | M              |
+| X_P_CHARGE      |                            |            |          |              | C              |
+| X_P_DISC_REASON |                            |            |          |              | C              |
+
+##### I.3.7.4.3 Service parameter descriptions
+
+Tables I.3-42 to I.3-45 describe the parameters for the Connection Release service.
+
+**Table I.3-42/T.180**
+
+|                |                                                          |
+|----------------|----------------------------------------------------------|
+| Parameter name | X_P_CONN_TIME                                            |
+| Type of value  | unsigned long                                            |
+| Legal values   | the time in seconds since 01.01.1970 00:00:00 GMT        |
+| Default value  | none                                                     |
+| Description    | This parameter contains the time of physical connection. |
+
+**Table I.3-43/T.180**
+
+|                |                                                                                                                                                                 |
+|----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_P_DISC_TIME                                                                                                                                                   |
+| Type of value  | unsigned long                                                                                                                                                   |
+| Legal values   | the time in seconds since 01.01.1970 00:00:00 GMT                                                                                                               |
+| Default value  | none                                                                                                                                                            |
+| Description    | This parameter contains the time of physical disconnection. If X_P_CONN_TIME and X_P_DISCON_TIME both set to zero, no physical connection could be established. |
+
+**Table I.3-44/T.180**
+
+|                |                                                                                                                                                          |
+|----------------|----------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_P_CHARGE                                                                                                                                               |
+| Type of value  | unsigned long                                                                                                                                            |
+| Legal values   | any number                                                                                                                                               |
+| Default value  | zero                                                                                                                                                     |
+| Description    | This parameter contains, if available, the charging unit of the connection. It is only set if both network and network connection provide this facility. |
+
+**Table I.3-45/T.180**
+
+|                |                                                                                                                         |
+|----------------|-------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_P_DISC_REASON                                                                                                         |
+| Type of value  | unsigned long                                                                                                           |
+| Legal values   | The values are directly mapped from the underlying hardware. See the hardware documentation to get further information. |
+| Default value  | zero                                                                                                                    |
+| Description    | This parameter contains, if available, the disconnection reason.                                                        |
+
+#### **I.3.7.5 Connection abort service**
+
+##### **I.3.7.5.1 Service description**
+
+The abort service provides the means by which either FAX4/BFT service user or provider can instantaneously release the connection and have the other FAX4/BFT service user informed of the release. Use of this service will cause loss of undelivered data.
+
+The service elements and their corresponding XAPI functions needed for abort of FAX4/BFT connection are described in Table I.3-46.
+
+**Table I.3-46/T.180 – Service elements and their corresponding XAPI functions for Connection Abort**
+
+| Service element  | XAPI function | Description                                                                                                                                                                                           |
+|------------------|---------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Abort Request    | x_snddis()    | The Abort Request is passed to the provider to request an abnormal FAX4/BFT connection release.                                                                                                       |
+| Abort Indication | x_rcvdis()    | The Abort Indication is generated by the provider to indicate the abnormal release of a FAX4/BFT connection.                                                                                          |
+| End Indication   | x_rcvend()    | The End Indication is generated by the provider to indicate that the service provider is ready to establish a new connection. In addition it contains some information about the released connection. |
+
+##### I.3.7.5.2 Service parameters
+
+Table I.3-47 specifies the parameters needed for an abortive FAX4/BFT release.
+
+**Table I.3-47/T.180 – Parameters of the Connection Abort service**
+
+| Parameter       | Abort Service |            |                |
+|-----------------|---------------|------------|----------------|
+|                 | Request       | Indication | End Indication |
+| X_FX4_P_REASON  | M             | M          |                |
+| X_P_CONN_TIME   |               |            | M              |
+| X_P_DISC_TIME   |               |            | M              |
+| X_P_CHARGE      |               |            | C              |
+| X_P_DISC_REASON |               |            | C              |
+
+##### I.3.7.5.3 Service parameter descriptions
+
+Tables I.3-48 to I.3-52 describe the parameters for the abort service.
+
+**Table I.3-48/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
+|----------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_FX4_P_REASON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
+| Type of value  | long                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
+| Legal values   | <p>Legal values for Request and Indication:</p> <p>X_FX4_PV_R_NO_REASON /* no error reason given */</p> <p>X_FX4_PV_R_LOCERR /* local terminal error */</p> <p>X_FX4_PV_R_PROCERR /* procedure error */</p> <p>X_FX4_PV_R_NOMEM /* no memory available */</p> <p>X_FX4_PV_R_TRANSERR /* transmission error */</p> <p>X_FX4_PV_R_PNOERR /* wrong page number */</p> <p>X_FX4_PV_R_FMTERR /* format error */</p> <p>Legal values only for the Indication:</p> <p>X_FX4_PV_R_NO_CTX /* no more contexts of this type */</p> <p>X_FX4_PV_R_LOCPROCERR /* local terminal and procedure error */</p> <p>X_FX4_PV_R_SSNAC /* session can not be accepted */</p> <p>X_FX4_PV_R_ERRMSG /* error message exists (text) */</p> <p>X_FX4_PV_R_RJCAP /* capabilities not supported */</p> <p>X_FX4_PV_R_SVOK /* return code positive */</p> <p>X_FX4_PV_R_SVNAV /* service not available */</p> |
+| Default value  | X_FX4_PV_R_NO_REASON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
+| Description    | This parameter indicates the abort reason.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
+
+**Table I.3-49/T.180**
+
+|                |                                                          |
+|----------------|----------------------------------------------------------|
+| Parameter name | X_P_CONN_TIME                                            |
+| Type of value  | unsigned long                                            |
+| Legal values   | the time in seconds since 01.01.1970 00:00:00 GMT        |
+| Default value  | none                                                     |
+| Description    | This parameter contains the time of physical connection. |
+
+**Table I.3-50/T.180**
+
+|                |                                                                                                                                                                 |
+|----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_P_DISC_TIME                                                                                                                                                   |
+| Type of value  | unsigned long                                                                                                                                                   |
+| Legal values   | the time in seconds since 01.01.1970 00:00:00 GMT                                                                                                               |
+| Default value  | none                                                                                                                                                            |
+| Description    | This parameter contains the time of physical disconnection. If X_P_CONN_TIME and X_P_DISCON_TIME both set to zero, no physical connection could be established. |
+
+**Table I.3-51/T.180**
+
+|                |                                                                                                                                                          |
+|----------------|----------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_P_CHARGE                                                                                                                                               |
+| Type of value  | unsigned long                                                                                                                                            |
+| Legal values   | any number                                                                                                                                               |
+| Default value  | zero                                                                                                                                                     |
+| Description    | This parameter contains, if available, the charging unit of the connection. It is only set if both network and network connection provide this facility. |
+
+**Table I.3-52/T.180**
+
+|                |                                                                                                                         |
+|----------------|-------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_P_DISC_REASON                                                                                                         |
+| Type of value  | unsigned long                                                                                                           |
+| Legal values   | The values are directly mapped from the underlying hardware. See the hardware documentation to get further information. |
+| Default value  | zero                                                                                                                    |
+| Description    | This parameter contains, if available, the disconnection reason.                                                        |
+
+#### **I.3.7.6 Usage of XAPI functions**
+
+This subclause provides some protocol-specific remarks to XAPI functions. The functions are mentioned in alphabetical order. If a function is not listed, there are no special remarks.
+
+- **x\_conconf** The user\_data buffer in the *call\_struct* is empty, as transfer of user data is not available in the connection establishment phase.
+- **x\_conind** The user\_data buffer in the *conind\_struct* is empty, as transfer of user data is not available in the connection establishment phase.
+- **x\_conreq** The user\_data buffer in the *call\_struct* is empty, as transfer of user data is not available in the connection establishment phase. Usage of the MORE flag is not supported.
+- **x\_conrsp** The user\_data buffer in the *call\_struct* is empty, as transfer of user data is not available in the connection establishment phase. Usage of the MORE flag is not supported.
+- **x\_rcvdata** Expedited data are not available.
+- **x\_rcvdis** The user\_data buffer in the *discon\_struct* is empty, as transfer of user data is not available in the disconnection.
+- **x\_relconf** The user\_data buffer in the *release\_struct* is empty, as transfer of user data is not available in the connection release phase.
+- **x\_relind** The user\_data buffer in the *release\_struct* is empty, as transfer of user data is not available in the connection release phase.
+- **x\_relreq** The user\_data buffer in the *release\_struct* is empty, as transfer of user data is not available in the connection release phase. Usage of the MORE flag is not supported.
+- **x\_relrsp** The user\_data buffer in the *release\_struct* is empty, as transfer of user data is not available in the connection release phase. Usage of the MORE flag is not supported.
+
+- **x\_snddata** This function can only be called, if FAX4/BFT service provider is in state 12 or 13. Expedited data is not available at the XAPI FAX4/BFT service access point. Usage of the MORE flag is not supported.
+- **x\_snddis** The user\_data buffer in the *discon\_struct* may not be used, as transfer of user data is not available in the disconnection. Usage of the MORE flag is not supported.
+- **x\_sndsp** Usage of the MORE flag is not supported.
+
+#### **I.3.7.7 Tables of error codes**
+
+The XAPI error-level error codes are defined in Annex B.
+
+##### **I.3.7.7.1 CC\_BADVALUE**
+
+An invalid mandatory parameter is given: *diagnostic* contains the corresponding parameter identifier.
+
+##### **I.3.7.7.2 CC\_MANDMISS**
+
+A mandatory parameter is missing: *diagnostic* contains the number of missing mandatory parameters.
+
+##### **I.3.7.7.3 CC\_BADEVENT**
+
+An invalid event is specified: *diagnostic* contains the bad event identifier.
+
+##### **I.3.7.7.4 CC\_SEQ**
+
+An incorrect sequence number is given: *diagnostic* contains the bad sequence number.
+
+##### **I.3.7.7.5 CC\_SPNAME**
+
+An invalid service primitive name is given: *diagnostic* contains the bad service primitive name.
+
+##### **I.3.7.7.6 CC\_ADDCOMP**
+
+An additional parameter (neither address parameter nor service primitive parameter) is incorrect: no *diagnostic* is given.
+
+##### **I.3.7.7.7 CC\_BADLENGTH**
+
+An address or parameter buffer contains an illegal length value: *diagnostic* contains the length.
+
+##### **I.3.7.7.8 CC\_UNEXPECT**
+
+If the cause code indicates an unexpected event, the value of *diagnostic* will contain the actual state identifier in which the unexpected event caused the error indication. Table I.3-53 contains the values defined for the *diagnostic* parameter.
+
+**Table I.3-53/T.180 – Data transfer states**
+
+| Name           | Description                                                                                                                                                                                                                                                   |
+|----------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| X_FX4_STATE_10 | <p>A service is requested, which is not expected in this state. Only the following services are expected:</p> <ul style="list-style-type: none"> <li>• X_FX4_SP_GIVE_TOKEN_Q</li> <li>• X_FX4_SP_SOD_Q</li> <li>• x_relreq()</li> <li>• x_snddis()</li> </ul> |
+| X_FX4_STATE_11 | <p>A service is requested, which is not expected in this state. Only the following service is expected:</p> <ul style="list-style-type: none"> <li>• x_snddis()</li> </ul>                                                                                    |
+| X_FX4_STATE_12 | <p>A service is requested, which is not expected in this state. Only the following services are expected:</p> <ul style="list-style-type: none"> <li>• x_snddata()</li> <li>• x_snddis()</li> </ul>                                                           |
+| X_FX4_STATE_13 | <p>A service is requested, which is not expected in this state. Only the following services are expected:</p> <ul style="list-style-type: none"> <li>• x_snddata()</li> <li>• X_FX4_SP_EOP_Q</li> <li>• X_FX4_SP_EOD_Q</li> <li>• x_snddis()</li> </ul>       |
+| X_FX4_STATE_14 | <p>A service is requested, which is not expected in this state. Only the following service is expected:</p> <ul style="list-style-type: none"> <li>• x_snddis()</li> </ul>                                                                                    |
+| X_FX4_STATE_15 | <p>A service is requested, which is not expected in this state. Only the following service is expected:</p> <ul style="list-style-type: none"> <li>• x_snddis()</li> </ul>                                                                                    |
+| X_FX4_STATE_20 | <p>A service is requested, which is not expected in this state. Only the following service is expected:</p> <ul style="list-style-type: none"> <li>• x_snddis()</li> </ul>                                                                                    |
+| X_FX4_STATE_21 | <p>A service is requested, which is not expected in this state. Only the following service is expected:</p> <ul style="list-style-type: none"> <li>• x_snddis()</li> </ul>                                                                                    |
+| X_FX4_STATE_22 | <p>A service is requested, which is not expected in this state. Only the following services are expected:</p> <ul style="list-style-type: none"> <li>• X_FX4_SP_EOP_P</li> <li>• x_snddis()</li> </ul>                                                        |
+| X_FX4_STATE_23 | <p>A service is requested, which is not expected in this state. Only the following services are expected:</p> <ul style="list-style-type: none"> <li>• X_FX4_SP_EOD_P</li> <li>• x_snddis()</li> </ul>                                                        |
+
+##### I.3.7.7.9 CC\_NOTSUPPORT
+
+An event is given, which is not supported; the value of *diagnostic* contains the identifier of the unsupported event which has been submitted with the XAPI function call that caused the error indication.
+
+##### I.3.7.7.10 CC\_OTHER
+
+If the cause code indicates the CC\_OTHER error code, the value of *diagnostic* contains the identifier which caused the error indication.
+
+#### I.3.7.8 Table of service primitives
+
+Table I.3-54/T.180
+
+| Name                  | Description                    |
+|-----------------------|--------------------------------|
+| X_FX4_SP_GIVE_TOKEN_Q | Give token request             |
+| X_FX4_SP_GIVE_TOKEN_I | Give token indication          |
+| X_FX4_SP_SOD_Q        | Start of document request      |
+| X_FX4_SP_SOD_I        | Start of document indication   |
+| X_FX4_SP_SOD_C        | Start of document confirmation |
+| X_FX4_SP_EOP_Q        | End of page request            |
+| X_FX4_SP_EOP_I        | End of page indication         |
+| X_FX4_SP_EOP_P        | End of page response           |
+| X_FX4_SP_EOP_C        | End of page confirmation       |
+| X_FX4_SP_EOD_Q        | End of document request        |
+| X_FX4_SP_EOD_I        | End of document indication     |
+| X_FX4_SP_EOD_P        | End of document response       |
+| X_FX4_SP_EOD_C        | End of document confirmation   |
+
+#### I.3.7.9 Table of service primitive parameters
+
+Table I.3-55/T.180
+
+| Name               | Legal values                 |
+|--------------------|------------------------------|
+| X_FX4_P_ACCEPT     | PV_TRUE<br>PV_FALSE          |
+| X_FX4_P_BFT_COMPR  | char [X_FX4_C_MAX_NAME]      |
+| X_FX4_P_BFT_FNAME  | char [X_FX4_C_MAX_NAME]      |
+| X_FX4_P_BFT_PATH   | char [X_FX4_C_MAX_PATH]      |
+| X_FX4_P_BLOCK_NR   | any number                   |
+| X_FX4_P_DATE_TIME  | char [X_FX4_C_MAX_DATE]      |
+| X_FX4_P_DOCREF     | char [X_FX4_C_MAX_DOC_REF]   |
+| X_FX4_P_DOC_TYPE   | X_FX4_PV_BFT<br>X_FX4_PV_FAX |
+| X_FX4_P_OWN_TERMID | char [X_FX4_C_MAX_TERMID]    |
+
+**Table I.3-55/T.180 (concluded)**
+
+| Name                    | Legal values                                                                                                                                                                                                                                                                                           |
+|-------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| X_FX4_P_FAR_TERMID      | char [X_FX4_C_MAX_TERMID]                                                                                                                                                                                                                                                                              |
+| X_FX4_P_FAX_COMPRESSION | PV_TRUE<br>PV_FALSE                                                                                                                                                                                                                                                                                    |
+| X_FX4_P_FAX_DENSITY     | X_FX4_PV_DENS_200.<br>X_FX4_PV_DENS_240.<br>X_FX4_PV_DENS_300.<br>X_FX4_PV_DENS_400.                                                                                                                                                                                                                   |
+| X_FX4_P_FAX_DIMENSION   | X_FX4_PV_DIM_A4<br>X_FX4_PV_DIM_B4<br>X_FX4_PV_DIM_A3<br>X_FX4_PV_DIM_AM_LETTER<br>X_FX4_PV_DIM_AM_LEGAL<br>X_FX4_PV_DIM_AM_LEDGER<br>X_FX4_PV_DIM_JAP_LETTER<br>X_FX4_PV_DIM_JAP_LEGAL                                                                                                                |
+| X_FX4_P_PAGE_NR         | number greater than 0                                                                                                                                                                                                                                                                                  |
+| X_FX4_P_PLEASE_TOKEN    | PV_TRUE<br>PV_FALSE                                                                                                                                                                                                                                                                                    |
+| X_FX4_P_REASON          | X_FX4_PV_R_NO_REASON<br>X_FX4_PV_R_NO_CTX<br>X_FX4_PV_R_LOCERR<br>X_FX4_PV_R_PROCERR<br>X_FX4_PV_R_LOCPROCERR<br>X_FX4_PV_R_SSNAC<br>X_FX4_PV_R_ERRMSG<br>X_FX4_PV_R_NOMEM<br>X_FX4_PV_R_TRANSERR<br>X_FX4_PV_R_PNOERR<br>X_FX4_PV_R_FMTERR<br>X_FX4_PV_R_RJCAP<br>X_FX4_PV_R_SVOK<br>X_FX4_PV_R_SVNAV |
+| X_FX4_P_REC_JEOP        | PV_TRUE<br>PV_FALSE                                                                                                                                                                                                                                                                                    |
+| X_P_CONN_TIME           | the time in seconds since 01.01.1970 00:00:00 GMT                                                                                                                                                                                                                                                      |
+| X_P_DISC_TIME           | the time in seconds since 01.01.1970 00:00:00 GMT                                                                                                                                                                                                                                                      |
+| X_P_CHARGE              | any number                                                                                                                                                                                                                                                                                             |
+| X_P_DISC_REASON         | The values are directly mapped from the underlying hardware. See the hardware documentation to get further information.                                                                                                                                                                                |
+
+## I.4 XAPI access to the service provider for ACSE and ROSE
+
+This part of Appendix I describes an example of how the service provider can be implemented, if an application needs the access to the specified service.
+
+### I.4.1 Scope
+
+The XAPI, which is an abbreviation for eXtensive Application Programming Interface, is an operating system and language-independent programming interface to general communication services. Detailed information about the XAPI is given in the main part of this Recommendation, which is very important for understanding this appendix.
+
+Which services are made available via the XAPI depends on the installed service providers, and not on the XAPI which only provides the access mechanism.
+
+This part describes the XAPI access to the ACSE/ROSE service provider.
+
+In this provider, the connection establishment, release and abort service are performed via the ACSE accessible at XAPI, whereas in the connected state the ROSE service is available via XAPI.
+
+Figure I.4-1 shows the structure of the protocol stack that is accessible via the XAPI.
+
+![Diagram of the ACSE/ROSE service provider protocol stack structure.](46c9f96273985599bf874713263feb52_img.jpg)
+
+```
+graph TD; Application[Application] <--> XAPI[XAPI]; XAPI <--> X227[X.227 protocol module]; XAPI <--> X229[X.229 protocol module]; X227 <--> X226[X.226 protocol module]; X229 <--> X226; X226 <--> X225[X.225 protocol module]; X225 <--> Transport[transport system comprising layers 1-4];
+```
+
+The diagram illustrates the structure of the ACSE/ROSE service provider protocol stack. It shows a vertical hierarchy of components connected by bidirectional arrows. At the top is the 'Application' box. Below it is the 'XAPI' box, which is shaded gray. The 'XAPI' box connects to two parallel boxes: 'X.227 protocol module' on the left and 'X.229 protocol module' on the right. Both of these connect to a single 'X.226 protocol module' box. This then connects to an 'X.225 protocol module' box, which finally connects to the bottom-most box, 'transport system comprising layers 1-4'. The 'XAPI' box is the central interface point for the application.
+
+T0827290-97
+
+Diagram of the ACSE/ROSE service provider protocol stack structure.
+
+**Figure I.4-1/T.180 – Structure of the ACSE/ROSE service provider**
+
+The XAPI user is able to select one transport system (comprising the layers 1 to 4) among the set of transport systems available in the XAPI communication platform to act as the underlying transport service provider.
+
+The interface is specified following the pattern of the standardized ROSE service interface [X.219] and the standardized ACSE service interface [X.217].
+
+### I.4.2 References
+
+The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; all users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published.
+
+- [I.430] ITU-T Recommendation I.430 (1995), *Basic user-network interface – Layer 1 specification.*
+- [I.431] ITU-T Recommendation I.431 (1993), *Primary rate user-network interface – Layer 1 specification.*
+- [T.90] CCITT Recommendation T.90 (1992), *Characteristics and protocols for terminals for telematic services in ISDN.*
+- [X.75] ITU-T Recommendation X.75 (1996), *Packet-switched signalling system between public networks providing data transmission services.*
+- [X.200] ITU-T Recommendation X.200 | ISO/IEC 7498-1:1994, *Information technology – Open Systems Interconnection – Basic reference model: The basic model.*
+- [X.208] CCITT Recommendation X.208 (1988), *Specification of Abstract Syntax Notation One (ASN 1).*
+- [X.214] ITU-T Recommendation X.214 (1995) | ISO/IEC 8072:1996, *Information technology – Open Systems Interconnection – Transport service definition.*
+- [X.217] ITU-T Recommendation X.217 (1995) | ISO/IEC 8649:1996, *Information technology – Open Systems Interconnection – Service definition for the association control service element.*
+- [X.219] CCITT Recommendation X.219 (1988) | ISO/IEC 9072-1:1989, *Remote operations: Model, notation and service definition.*
+- [X.224] ITU-T Recommendation X.224 (1995) | ISO/IEC 8073:1997, *Information technology – Open Systems Interconnection – Protocol for providing the connection-mode transport service.*
+- [X.225] ITU-T Recommendation X.225 (1995) | ISO/IEC 8327-1:1996, *Information technology – Open Systems Interconnection – Connection-oriented session protocol: Protocol specification.*
+- [X.226] ITU-T Recommendation X.226 (1994) | ISO/IEC 8823-1:1994, *Information technology – Open Systems Interconnection – Connection-oriented presentation protocol: Protocol specification.*
+- [X.227] ITU-T Recommendation X.227 (1995) | ISO/IEC 8650-1:1996, *Information technology – Open Systems Interconnection – Connection-oriented protocol for the association control service element: Protocol specification.*
+
+[X.229] CCITT Recommendation X.229 (1988) | ISO/IEC 9072-2:1989, *Remote operations: Protocol specification*.
+
+[ISO 8208] ISO/IEC 8208:1995, *Information technology – Data communications – X.25 Packet Layer Protocol for Data Terminal Equipment*.
+
+### **I.4.3 Definitions**
+
+### **I.4.4 Abbreviations**
+
+This part uses the following abbreviations:
+
+|       |                                                                                                                                  |
+|-------|----------------------------------------------------------------------------------------------------------------------------------|
+| ACS   | abbreviation string specifying service specific definitions of the ACSE provider (e.g. parameter names, service primitive names) |
+| ACSE  | Association Control Service Element                                                                                              |
+| APDU  | Application Protocol Data Unit                                                                                                   |
+| ASE   | Application Service Element                                                                                                      |
+| DSS 1 | Digital Subscriber Signalling System No. 1                                                                                       |
+| HDLC  | High-Level Data-Link Control                                                                                                     |
+| ISDN  | Integrated Services Digital Network                                                                                              |
+| ISO   | International Organization for Standardization                                                                                   |
+| NSAP  | Network Service Access Point                                                                                                     |
+| OSI   | Open Systems Interconnection                                                                                                     |
+| PSAP  | Presentation Service Access Point                                                                                                |
+| PSEL  | Presentation Selector                                                                                                            |
+| ROS   | abbreviation string specifying service specific definitions of the ROSE provider (e.g. parameter names, service primitive names) |
+| ROSE  | Remote Operations Service Element                                                                                                |
+| RTSE  | Reliable Transfer Service Element                                                                                                |
+| SSAP  | ACSE/ROSE Service Access Point                                                                                                   |
+| SSEL  | Session Service Selector                                                                                                         |
+| TSAP  | Transport Service Access Point                                                                                                   |
+| TSEL  | Transport Service Selector                                                                                                       |
+| XAPI  | eXtensive Application Programming Interface                                                                                      |
+
+### **I.4.5 Conventions**
+
+Each service is described via three kinds of tables.
+
+In the first kind of table the service and its service elements are described. It contains a row for each service element of the service (where service element means either request, indication, response, or confirmation) with its corresponding XAPI function and a short description.
+
+In the second kind of table the use of the service primitive parameters within the service elements are described. It contains a row for each service primitive parameter of the service. The service primitive parameter name is stored within the first column, the following columns contain the use of the parameter in the service elements:
+
+|       |                                                                                                                                                                                                                                                                                                                                                                                                                                      |
+|-------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Blank | The service parameter is absent.                                                                                                                                                                                                                                                                                                                                                                                                     |
+| C     | Presence of the service parameter is conditional. Firstly, there may be a condition in the service provider to provide a parameter in an indication or confirmation; secondly, there may be interdependencies between parameters of the same or the preceding service primitive.                                                                                                                                                     |
+| M     | Presence of the service parameter is mandatory.                                                                                                                                                                                                                                                                                                                                                                                      |
+| U     | Presence of the service parameter is a user option. If the user does not specify a value for such a parameter and there is no default value for that parameter, nothing is passed to the service provider. If the user does not specify a value for such a parameter and there is a default value, the default value is passed to the service provider.                                                                              |
+| (=)   | The value of the service parameter is identical to the value of the corresponding service parameter in the preceding service element. In the special case of a parameter, whose presence in the preceding service is a user option, for which a default value is defined, and the parameter was not specified in the preceding service element, the symbol (=) indicates that the parameter value is identical to the default value. |
+
+The third kind of table is used to describe the service primitive parameter containing the type of value and its scope, possible default values and a detailed description. For each service primitive parameter, one description table is given.
+
+A **naming convention** is used throughout the XAPI in order to distinguish between the common functions, identifiers and values, and service specific identifiers and values. All service-specific settings of the XAPI ACSE/ROSE service access are defined within the present part of this appendix and start with **X\_ROS\_**, **x\_ros\_**, **X\_ACS**, or **x\_acs**.
+
+Extended naming conventions:
+
+- SP\_ Service Primitive;
+- P\_ Parameter;
+- PV\_ Parameter Value;
+- O\_ Option;
+- OV\_ Option Value.
+
+### I.4.6 Introduction to the ACSE/ROSE provider access
+
+The ACSE/ROSE service is provided by the combination of a transport system and the Session, Presentation, ACSE and ROSE protocol module, selected by the application. The ROSE protocol module is implemented according to the requirements of [X.229] and the service which is provided follows the pattern of [X.219]. The ACSE protocol module is implemented according to the requirements of [X.227] and the service which is provided follows the pattern of [X.217].
+
+It provides basic facilities for the control of an application-association between two application-entities which communicate by means of a presentation-connection, e.g.
+
+- establish an association with another ACSE user;
+- normal release of an association with another ACSE user; and
+- abnormal release of an association with another ACSE user.
+
+It provides the means of interactive applications between cooperating ACSE/ROSE users. An application can:
+
+- invoke operations by one ACSE/ROSE user and perform operations by another ACSE/ROSE user;
+
+- support synchronous and asynchronous operations;
+- group operations into a set of linked operations;
+- perform the control of the application association by ACSE.
+
+The referenced Remote Operation notation (RO-notation) allows an Application Service Element (ASE) to be defined for the support of a particular application or group of applications. This ASE consists of a BIND operation (establishes an association), one or more operations to implement an interactive protocol, and an UNBIND operation (releases the association). The BIND and UNBIND operations are implemented using the services provided by ACSE while the other operations are implemented using the ROSE services. Therefore, the service provider gives access to the services of the ROSE plus those of the ACSE service.
+
+#### **I.4.6.1 Restrictions to Recommendations X.227 and X.229**
+
+The ACSE service supports two modes of operation, i.e. the normal mode and the X.410-1984 mode. At the XAPI, only the normal mode is accessible, which allows the ACSE user to take full advantage of the functionality provided by both ACSE and the presentation service.
+
+Functional units are used for the purpose of identification of Presentation service user requirements and are negotiated during connection establishment.
+
+Two categories of functional units are supported by the service provider:
+
+- a) Session functional units, comprising:
+  - Kernel;
+  - Duplex;
+  - Half-duplex;
+  - Minor synchronize;
+  - Exception;
+  - Capability data;
+  - Activity management.
+- b) Presentation functional units, comprising:
+  - Kernel.
+
+The Presentation Context Definition List is also negotiated during connection establishment. To each abstract syntax a transfer syntax is assigned, which is used for encoding and decoding the user data during the lifetime of the connection. The possibility to negotiate a default context, as it is provided by the ACSE Recommendation, is not supposed. Therefore, the negotiation of the Presentation Context Definition List is mandatory during connection establishment. The negotiation is described in the next subclause.
+
+#### **I.4.6.2 Service-specific features**
+
+Due to the goal of a modular and object-oriented design of the protocol modules, special attention to the encoding/decoding mechanism of the user data is required.
+
+The idea is, that each protocol itself encodes/decodes its PDUs to make the Presentation layer independent of the layers above with their abstract syntax and transfer syntaxes. As a consequence (and extending the standardized service interface), the application does not only provide the context identifier and abstract syntax for each presentation context (i.e. each protocol module above presentation) but also the (list of) transfer syntaxes supported by each protocol module.
+
+This has the following consequences for the ACSE-user:
+
+##### – *Negotiation of the presentation context definition list*
+
+During connection establishment, a presentation context definition list is negotiated by the ACSE-user communication partners. It consists of a list of triples, one for each abstract syntax, which is proposed by the association initiator and accepted (or not accepted) by the association responder. Each triple consists of an odd integer identifying the triple, the abstract syntax and the (list of) supported transfer syntaxes. The odd integer identifying the triple is called presentation context identifier. After negotiation, only the presentation context identifier is used to identify an abstract syntax and the corresponding transfer syntax.
+
+NOTE – It must be ensured that the transfer syntaxes proposed in the presentation context definition list match the supported transfer syntaxes of the protocol modules of the service provider.
+
+##### – *Encoding and decoding of the user data*
+
+ACSE user data are treated as transparent data by the ACSE protocol module. If there is any special format to be used for the ACSE user data, it is up to the application to generate and interpret that format. The application is required to encode/decode the ACSE user data passed/received to/from XAPI in the *user\_data* parameter of *call\_struct*, *release\_struct* or *discon\_struct*. The data in the user data must be encoded as a data stream comprising a list of one or more non-concatenated ASN.1 EXTERNAL types. The following rules apply to the components of the EXTERNAL type:
+
+- If presentation context negotiation has been completed, the presentation context identifier also identifies the encoding rules (transfer syntax) for the data value and the "direct-reference OBJECT IDENTIFIER" shall not be included;
+- If presentation context negotiation is not complete, an object identifier value is also needed which identifies the encoding rules (transfer syntax) used for the encoding.
+
+ROSE defines five different Operation Classes which classify operations according to two possible operation modes (synchronous and asynchronous). The Association Class defines which ROSE user is allowed to invoke operations. The Operation Class and Association Class have to be agreed between ROSE users. It is not part of the ACSE/ROSE provider to negotiate these features. OSI Applications making use of ROSE (e.g. DTAM, DFR, MHS) define which Operation Class and Association Class are allowed within a specific application.
+
+Due to the fact that there is no negotiation of Operation and Association Class within the ACSE/ROSE provider, the parameters Invoke-Id (to identify an operation and to correlate the request of an invocation with its replies) and Linked-Id (in the case of a child operation to identify the parent operation) can not be examined by ACSE/ROSE. In particular, it is not controlled if an invocation exists for an incoming reply, i.e. result, error or rejection, or if the specified parent operation exists for the invocation of a child operation.
+
+ACSE/ROSE does not define a distinct abstract syntax for the encoding of its PDUs. Instead, it provides a set of abstract syntax definitions that are used by the application making use of ACSE/ROSE. Therefore, the service user must inform the service provider which abstract syntaxes are used within the ROSE PDUs. To support this feature, each ROSE service primitive must be provided with a service primitive parameter (X\_ROS\_P\_CTXT\_ID) that indicates the abstract syntax of the application.
+
+##### **BIND and UNBIND encoding**
+
+At the XAPI, the ACSE/ROSE BIND/UNBIND operations are implemented using the primitives of the ACSE services A\_ASSOCIATE and A\_RELEASE.
+
+##### Application data encoding
+
+The *argument*, *result*, or *parameter* components of ROSE APDUs are treated as transparent data by the ROSE protocol module. It is under the responsibility of the XAPI user to encode and decode the application data.
+
+### I.4.7 Description of the access to the ACSE/ROSE provider
+
+#### I.4.7.1 Service initialization
+
+##### I.4.7.1.1 Creation of a service access point with *x\_open()*
+
+A communication endpoint accessing the ACSE and ROSE protocol modules is created when calling the *x\_open()* function with an appropriate service provider identification string. A communication endpoint accessing the ROSE protocol module is always created together. The available identifiers depend on the actual system configuration. In the standard configuration "**X\_ACSE\_ROSE\_ISDN**" identifies the ISO ACSE/ROSE service provider with access to the ROSE and ACSE services. In this case the application system comprises the ISO Session, Presentation, ACSE and ROSE protocol modules; the transport system comprises ISO Transport Class 0, ISO 8208, HDLC LAP B and I.430/I.431.
+
+##### I.4.7.1.2 Activation of a service access point with *x\_bind()*
+
+*x\_bind()* is to be called to activate the service endpoint. The function has the following tasks:
+
+- if the service provider, which has been selected with *x\_open()*, does not comprise a transport system, link a transport system below the available protocol modules;
+- bind an address to the service endpoint.
+
+In the standard configuration, if "**X\_ACSE\_ROSE\_ISDN**" was selected in the *x\_open()* function, no transport system has to be specified as argument of the *x\_bind()* function as the service provider's protocol stack is already complete.
+
+##### I.4.7.1.3 Protocol addresses
+
+The address to be used to identify the peer entity is the tuple of  
+(PSEL, SSEL, TSEL, NSAP Address),
+
+where the selectors are optional depending on the peer's requirements.
+
+The XAPI service provider itself does not support selectors as address information on the local side; the own address consists of the NSAP address only.
+
+###### I.4.7.1.3.1 The application's own address
+
+The own address (only NSAP is supported as explained above) may be specified in the *own\_address* buffer of the *bind\_struct* passed as argument to the *x\_bind()* function. For a passive application, it is returned in the *called\_addr* buffer of the *x\_conind()* function.
+
+For a passive application it is not supported to specify the own responding NSAP address in the *address* buffer of the *call\_struct* in the *x\_conrsp()* function, as this value is not transferred by the network.
+
+Note that specification of the application's own protocol address is completely optional. If no address information is specified, the own address is derived from system configuration information and the value actually bound is returned as output parameter of the *x\_bind()* function.
+
+The own address consists of the NSAP address only. The NSAP address has to comprise the local ISDN outband address, i.e. the address information used in the D-channel. The own ISDN inband address and subaddress parameters as well as the protocol selectors are not supported. If specified, they will be ignored.
+
+Table I.4-1 shows the address component which has to be specified in the *x\_bind()* call.
+
+**Table I.4-1/T.180 – Address component specified in the *x\_bind()* call**
+
+| ISDN network | Address component | Value                                                                            |
+|--------------|-------------------|----------------------------------------------------------------------------------|
+| ISDN/DSS 1   | A_OUTBAND_ADR     | A decimal digit, which is locally mapped on the Multiple Subscriber Number (MSN) |
+
+###### I.4.7.1.3.2 The address of the communication partner
+
+On the sending side, the address of the communication partner has to be specified in the *address* buffer of the *call\_struct* passed as argument to the *x\_conreq()* function. On the receiving side, the address of the communication partner is returned in the *calling\_addr* buffer of the *x\_conind()* function.
+
+The address of the communication partner comprises at least the peer's ISDN outband address. The peer's ISDN inband address and subaddress are meaningless, whereas usage of protocol selectors is according to the peer's requirements.
+
+Table I.4-2 shows the address components to be used in the *address* buffer specifying the called Presentation address in an *x\_conreq()* call:
+
+**Table I.4-2/T.180 – Address components specifying the called NSAP address in an *x\_conreq()* call**
+
+| ISDN network | Address component | Value                                                                                      |
+|--------------|-------------------|--------------------------------------------------------------------------------------------|
+| ISDN/DSS 1   | A_OUTBAND_ADR     | optional the country code, optional the area code and the multiple subscriber number (MSN) |
+| ISDN/DSS 1   | A_T_SELECTOR      | called Transport selector (optional)                                                       |
+| ISDN/DSS 1   | A_S_SELECTOR      | called Session selector (optional)                                                         |
+| ISDN/DSS 1   | A_P_SELECTOR      | called Presentation selector (optional)                                                    |
+
+##### I.4.7.1.4 Configuration of the service provider
+
+The protocol modules of the service provider behave according to configured protocol options. Protocol options are used to control the general behaviour of a protocol module (they must not be confounded with service primitive parameters). The pre-configured values of the protocol options are sufficient for the majority of communication relations.
+
+Currently, there are no options for the protocol modules of the Presentation service provider, which could be set by the XAPI function *x\_optmgmt()*.
+
+#### **I.4.7.2 Connection Establishment service**
+
+##### **I.4.7.2.1 Service description**
+
+During the connection establishment phase, two users of the same service establish a connection between them. The XAPI user must already have prepared a service endpoint before the connection establishment phase can start.
+
+The service elements and their corresponding XAPI functions needed for ACSE Connection Establishment are described in the Table I.4-3.
+
+**Table I.4-3/T.180 – Service elements and their corresponding XAPI functions for Connection Establishment**
+
+| <b>Service element</b> | <b>XAPI function</b> | <b>Description</b>                                                                                                                       |
+|------------------------|----------------------|------------------------------------------------------------------------------------------------------------------------------------------|
+| Connect Request        | x_conreq()           | The Connect Request is passed to the provider to request the establishment of a connection.                                              |
+| Connect Indication     | x_conind()           | The Connect Indication is generated by the provider to indicate the request from a remote terminal to establish a connection.            |
+| Connect Response       | x_conrsp()           | The Connect Response is passed to the provider as reaction to a previously received Connect Indication as positive or negative response. |
+| Connect Confirmation   | x_conconf()          | The Connect Confirmation is generated by the provider of a local establishment.                                                          |
+
+##### **I.4.7.2.2 Service parameters**
+
+Table I.4-4 specifies the parameters of the ACSE Connection Establishment service.
+
+NOTE – Some parameters belong together forming one data structure, so that they have to occur in a special order.
+
+The first is the context definition list, which is formed by a list of triples comprising the presentation context id, the abstract syntax and a (list of) supported transfer syntaxes. Each triple must occur always in the same order within the parameter buffer. The order is X\_ACS\_P\_CTXT\_ID, X\_ACS\_P\_AS and (possibly several times) X\_ACS\_P\_TS.
+
+The second is the context definition result list, which is also formed by a list of triples comprising the presentation context identifier, the result, i.e. acceptance or rejection of the proposed presentation context and, if the result is acceptance, the transfer syntax, which should be used. There are as many triples as there are in the presentation context definition list.
+
+The value of diagnosis parameter (X\_ACS\_P\_DIAG) depends on the value of the result source parameter (X\_ACS\_P\_RES\_SRC). Thus, it is important that the result source precedes the diagnosis.
+
+**Table I.4-4/T.180 – Parameters of the Connection Establishment service**
+
+| Parameter              | Connect Service |            |          |              |
+|------------------------|-----------------|------------|----------|--------------|
+|                        | Request         | Indication | Response | Confirmation |
+| X_ACS_P_MAX_SUDATA     |                 | M          |          | C            |
+| X_ACS_P_APP_CTXT       | M               | M (=)      | M        | M (=)        |
+| X_ACS_P_CTXT_ID        | M               | M (=)      |          |              |
+| X_ACS_P_AS             | M               | M (=)      |          |              |
+| X_ACS_P_TS             | U               | C (=)      |          |              |
+| X_ACS_P_CTXT_RES       |                 | M          | M        | M (=)        |
+| X_ACS_P_TS_RES         |                 | C          | C        | C (=)        |
+| X_ACS_P_RES            |                 |            | M        | M (=)        |
+| X_ACS_P_RES_SRC        |                 |            |          | M            |
+| X_ACS_P_DIAG           |                 |            | U        | C (=)        |
+| X_ACS_P_SUR            | M               | M (=)      | M        | M (=)        |
+| X_ACS_P_CAG_AEQ        | U               | C (=)      |          |              |
+| X_ACS_P_CAG_AEID       | U               | C (=)      |          |              |
+| X_ACS_P_CAG_APT        | U               | C (=)      |          |              |
+| X_ACS_P_CAG_APIID      | U               | C (=)      |          |              |
+| X_ACS_P_CAD_AEQ        | U               | C (=)      |          |              |
+| X_ACS_P_CAD_AEID       | U               | C (=)      |          |              |
+| X_ACS_P_CAD_APT        | U               | C (=)      |          |              |
+| X_ACS_P_CAD_APIID      | U               | C (=)      |          |              |
+| X_ACS_P_RES_AEQ        |                 |            | U        | C (=)        |
+| X_ACS_P_RES_AEID       |                 |            | U        | C (=)        |
+| X_ACS_P_RES_APT        |                 |            | U        | C (=)        |
+| X_ACS_P_RES_APIID      |                 |            | U        | C (=)        |
+| X_ACS_P_INIT_SYN_POINT | C               | C (=)      | C        | C (=)        |
+| X_ACS_P_TOKEN          | C               | C (=)      | C        | C (=)        |
+| X_ACS_P_S_CASUR        | U               | C (=)      |          |              |
+| X_ACS_P_S_CDSUR        |                 |            | U        | C (=)        |
+| X_ACS_P_S_CR           | U               | C (=)      | U        | C (=)        |
+| X_ACS_P_S_ARI          | U               | C (=)      | U        | C (=)        |
+| X_ACS_P_PROV_REJ       |                 |            | U        |              |
+
+##### I.4.7.2.3 Service parameter description
+
+Tables I.4-5 to I.4-34 list the parameters for the Connection Establishment service.
+
+**Table I.4-5/T.180**
+
+|                |                                                                                                                                                                                                                           |
+|----------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_ACS_P_MAX_SUDATA                                                                                                                                                                                                        |
+| Type of value  | unsigned long                                                                                                                                                                                                             |
+| Legal values   | X_ACS_PV_RESTRICTED, i.e. session user data are restricted<br>X_ACS_PV_UNRESTRICTED, i.e. session user data are not restricted                                                                                            |
+| Default value  | none                                                                                                                                                                                                                      |
+| Description    | A restriction of the session service user data length causes restrictions for the ACSE user data.<br>The total length of an ASN.1 coded presentation PDU embedding an ASN.1 coded ACSE PDU is restricted to 65 539 bytes. |
+
+**Table I.4-6/T.180**
+
+|                |                                                                                                                                                           |
+|----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_ACS_P_APP_CTXT                                                                                                                                          |
+| Type of value  | long[]                                                                                                                                                    |
+| Legal values   | Values must be given as a sequence of long values which form an object identifier identifying the application context name.                               |
+| Default value  | none                                                                                                                                                      |
+| Description    | The parameter identifies the application context. In the Response or Confirmation service either the same or a different application context is returned. |
+
+**Table I.4-7/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                       |
+|----------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_ACS_P_CTXT_ID                                                                                                                                                                                                                                                                                                                                                                                       |
+| Type of value  | long                                                                                                                                                                                                                                                                                                                                                                                                  |
+| Legal values   | Odd integer values which must be different for each presentation context definition.                                                                                                                                                                                                                                                                                                                  |
+| Default value  | none                                                                                                                                                                                                                                                                                                                                                                                                  |
+| Description    | The parameter indicates the presentation context identification. The parameter has to be immediately followed by the parameter X_ACS_P_AS and (several) X_ACS_P_TS at the XAPI interface. X_ACS_P_CTXT_ID, X_ACS_P_AS and (several) X_ACS_P_TS are components of the presentation context definition. There may be a list of those triples which constitute the presentation context definition list. |
+
+**Table I.4-8/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                           |
+|----------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_ACS_P_AS                                                                                                                                                                                                                                                                                                                                                                                |
+| Type of value  | long[]                                                                                                                                                                                                                                                                                                                                                                                    |
+| Legal values   | Values must be given as a sequence of long values which form an object identifier identifying an abstract syntax.                                                                                                                                                                                                                                                                         |
+| Default value  | none                                                                                                                                                                                                                                                                                                                                                                                      |
+| Description    | The parameter indicates the abstract syntax name. The parameter must follow the parameter X_ACS_P_CTXT_ID and must be followed by (several) X_ACS_P_TS at the XAPI interface. X_ACS_P_CTXT_ID, X_ACS_P_AS and (several) X_ACS_P_TS are components of the presentation context definition. There may be a list of those triples which constitute the presentation context definition list. |
+
+**Table I.4-9/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                             |
+|----------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_ACS_P_TS                                                                                                                                                                                                                                                                                                                                                  |
+| Type of value  | long[]                                                                                                                                                                                                                                                                                                                                                      |
+| Legal values   | Values must be given as a sequence of long values which form an object identifier identifying an transfer syntax.                                                                                                                                                                                                                                           |
+| Default value  | {2, 1, 1} the object identifier of transfer syntax X.209                                                                                                                                                                                                                                                                                                    |
+| Description    | The parameter indicates the transfer syntax name. The parameter must follow the parameter X_ACS_P_CTXT_ID and X_ACS_P_AS at the XAPI interface. X_ACS_P_CTXT_ID, X_ACS_P_AS and (several) X_ACS_P_TS are components of the presentation context definition. There may be a list of those triples which constitute the presentation context definition list. |
+
+**Table I.4-10/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
+|----------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_ACS_P_CTXT_RES                                                                                                                                                                                                                                                                                                                                                                                                                                        |
+| Type of value  | long                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
+| Legal values   | <p>The value indicates the acceptance or rejection of the presentation context definition. The following legal values are defined:</p> <p style="margin-left: 40px;">X_ACS_PV_CTXT_ACC      Acceptance;</p> <p style="margin-left: 40px;">X_ACS_PV_CTXT_REJ_U    User rejection;</p> <p style="margin-left: 40px;">X_ACS_PV_CTXT_REJ_P    Provider rejection;</p> <p style="margin-left: 40px;">X_ACS_PV_CTXT_UNDEF    Result is not specified yet.</p> |
+| Default value  | none                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
+| Description    | The parameter indicates the acceptance or rejection of each presentation context definition list parameter. The parameter must be followed by X_RTS_P_TS_RES at the XAPI interface. X_ACS_P_CTXT_RES and X_ACS_P_TS_RES are components of the presentation context definition result. There may be a list of those tuples which constitute the presentation context definition result list.                                                             |
+
+**Table I.4-11/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
+|----------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_ACS_P_TS_RES                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
+| Type of value  | long[]                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
+| Legal values   | Values must be given as a sequence of long values which form an object identifier identifying a transfer syntax.                                                                                                                                                                                                                                                                                                                                                                                            |
+| Default value  | {2, 1, 1} the object identifier of transfer syntax X.209                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
+| Description    | The parameter indicates the transfer syntax name, which has been chosen out of the list of proposed transfer syntaxes within the context definition list and which has to be used. The parameter must follow the parameter X_ACS_P_CTXT_RES at the XAPI interface only if the result is acceptance. X_ACS_P_CTXT_RES and X_ACS_P_TS_RES are components of the presentation context definition result. There may be a list of those tuples which constitute the presentation context definition result list. |
+
+**Table I.4-12/T.180**
+
+|                |                                                                                                                                                                  |
+|----------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_ACS_P_RES                                                                                                                                                      |
+| Type of value  | unsigned long                                                                                                                                                    |
+| Legal values   | X_ACS_PV_ACCEPT Association accepted;<br>X_ACS_PV_REJ_PERM Permanent rejection of the association;<br>X_ACS_PV_REJ_TRANS Transient rejection of the association. |
+| Default value  | none                                                                                                                                                             |
+| Description    | The parameter indicates the result of the connection establishment procedure.                                                                                    |
+
+**Table I.4-13/T.180**
+
+|                |                                                                                                                                                                                           |
+|----------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_ACS_P_RES_SRC                                                                                                                                                                           |
+| Type of value  | unsigned long                                                                                                                                                                             |
+| Legal values   | X_ACS_PV_ACSE_SU ACSE service user;<br>X_ACS_PV_ACSE_SP ACSE service provider;<br>X_ACS_PV_PRESENT_SP Presentation service provider.                                                      |
+| Default value  | none                                                                                                                                                                                      |
+| Description    | The parameter indicates the resulting source of the X_ACS_P_RES parameter. If the value of the X_ACS_P_RES parameter is X_ACS_PV_ACCEPT, the value of this parameter is X_ACS_PV_ACSE_SU. |
+
+**Table I.4-14/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
+|----------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_ACS_P_DIAG                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
+| Type of value  | unsigned long                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
+| Legal values   | X_ACS_PV_UNUSED<br>X_ACS_PV_NO_ACSE<br>X_ACS_PV_NO_REASON<br>X_ACS_PV_APP_CTXT_NAME<br>X_ACS_PV_CAG_AP_TITLE<br>X_ACS_PV_CAG_AE_QUAL<br>X_ACS_PV_CAG_AP_ID<br><br>X_ACS_PV_CAG_AE_ID<br><br>X_ACS_PV_CAD_AP_TITLE<br>X_ACS_PV_CAD_AE_QUAL<br>X_ACS_PV_CAD_AP_ID<br><br>X_ACS_PV_CAD_AE_ID                                                                                                                                                                                                      | UNUSED<br>No common ACSE version;<br>No reason given;<br>Application context name not supported;<br>Calling AP title not recognized;<br>Calling AE qualifier not recognized;<br>Calling AP invocation identifier not recognized;<br><br>Calling AE invocation identifier not recognized;<br><br>Called AP title not recognized;<br>Called AE qualifier not recognized;<br>Called AP invocation identifier not recognized;<br><br>Called AE invocation identifier not recognized. |
+| Default value  | none                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
+| Description    | <p>The parameter provides diagnostic information about the result of the connection services. The parameter is only used if the X_ACS_P_RES parameter has the value X_ACS_PV_REJ_PERM or X_ACS_PV_REJ_TRANS.</p> <p>If the X_ACS_P_RES_SRC parameter has the value X_ACS_PV_ACSE_SP, this parameter can take the values X_ACS_PV_UNUSED and X_ACS_PV_NO_ACSE. If the X_ACS_P_RES_SRC parameter has the value X_ACS_PV_ACSE_SU, this parameter can take all values except X_ACS_PV_NO_ACSE.</p> |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
+
+**Table I.4-15/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                        |  |
+|----------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--|
+| Parameter name | X_ACS_P_SUR                                                                                                                                                                                                                                                                                            |  |
+| Type of value  | unsigned long                                                                                                                                                                                                                                                                                          |  |
+| Legal values   | X_ACS_PV_SUR_HALFDUPLEX<br>X_ACS_PV_SUR_DUPLEX<br>X_ACS_PV_SUR_MINSYNC<br>X_ACS_PV_SUR_EXCEPT<br>X_ACS_PV_SUR_CDATA<br>X_ACS_PV_SUR_ACTMGMT                                                                                                                                                            |  |
+| Default value  | none                                                                                                                                                                                                                                                                                                   |  |
+| Description    | <p>The parameter indicates the session user requirements = functional units. The values form a bitmask and must be given as one or more items in the integer format OR'ed together (e.g. X_ACS_PV_SUR_HALFDUPLEX   X_ACS_PV_SUR_ACTMGMT). Not all combination of values are allowed (see [X.217]).</p> |  |
+
+**Table I.4-16/T.180**
+
+|                |                                                                                                |
+|----------------|------------------------------------------------------------------------------------------------|
+| Parameter name | X_ACS_P_CAG_AEQ                                                                                |
+| Type of value  | char[]                                                                                         |
+| Legal values   | buffer with user encoded AE-qualifier                                                          |
+| Default value  | none                                                                                           |
+| Description    | The parameter indicates the calling AE-qualifier. It must be encoded as ANY single ASN.1 type. |
+
+**Table I.4-17/T.180**
+
+|                |                                                                |
+|----------------|----------------------------------------------------------------|
+| Parameter name | X_ACS_P_CAG_AEID                                               |
+| Type of value  | long                                                           |
+| Legal values   | any integer value                                              |
+| Default value  | none                                                           |
+| Description    | This parameter indicates the calling AE invocation identifier. |
+
+**Table I.4-18/T.180**
+
+|                |                                                                                             |
+|----------------|---------------------------------------------------------------------------------------------|
+| Parameter name | X_ACS_P_CAG_APT                                                                             |
+| Type of value  | char[]                                                                                      |
+| Legal values   | buffer with user encoded AP title                                                           |
+| Default value  | none                                                                                        |
+| Description    | The parameter identifies the calling AP-title. It must be encoded as ANY single ASN.1 type. |
+
+**Table I.4-19/T.180**
+
+|                |                                                                |
+|----------------|----------------------------------------------------------------|
+| Parameter name | X_ACS_P_CAG_APIID                                              |
+| Type of value  | long                                                           |
+| Legal values   | any integer value                                              |
+| Default value  | none                                                           |
+| Description    | This parameter indicates the calling AP invocation identifier. |
+
+**Table I.4-20/T.180**
+
+|                |                                                                                               |
+|----------------|-----------------------------------------------------------------------------------------------|
+| Parameter name | X_ACS_P_CAD_AEQ                                                                               |
+| Type of value  | char[]                                                                                        |
+| Legal values   | buffer with user encoded AE-qualifier                                                         |
+| Default value  | none                                                                                          |
+| Description    | The parameter indicates the called AE-qualifier. It must be encoded as ANY single ASN.1 type. |
+
+**Table I.4-21/T.180**
+
+|                |                                                               |
+|----------------|---------------------------------------------------------------|
+| Parameter name | X_ACS_P_CAD_AEID                                              |
+| Type of value  | long                                                          |
+| Legal values   | any integer value                                             |
+| Default value  | none                                                          |
+| Description    | This parameter indicates the called AE invocation identifier. |
+
+**Table I.4-22/T.180**
+
+|                |                                                                                            |
+|----------------|--------------------------------------------------------------------------------------------|
+| Parameter name | X_ACS_P_CAD_APT                                                                            |
+| Type of value  | char[]                                                                                     |
+| Legal values   | buffer with user encoded AP title                                                          |
+| Default value  | none                                                                                       |
+| Description    | The parameter identifies the called AP-title. It must be encoded as ANY single ASN.1 type. |
+
+**Table I.4-23/T.180**
+
+|                |                                                               |
+|----------------|---------------------------------------------------------------|
+| Parameter name | X_ACS_P_CAD_APIID                                             |
+| Type of value  | long                                                          |
+| Legal values   | any integer value                                             |
+| Default value  | none                                                          |
+| Description    | This parameter indicates the called AP invocation identifier. |
+
+**Table I.4-24/T.180**
+
+|                |                                                                                                   |
+|----------------|---------------------------------------------------------------------------------------------------|
+| Parameter name | X_ACS_P_RES_AEQ                                                                                   |
+| Type of value  | char[]                                                                                            |
+| Legal values   | buffer with user encoded AE-qualifier                                                             |
+| Default value  | none                                                                                              |
+| Description    | The parameter indicates the responding AE-qualifier. It must be encoded as ANY single ASN.1 type. |
+
+**Table I.4-25/T.180**
+
+|                |                                                                   |
+|----------------|-------------------------------------------------------------------|
+| Parameter name | X_ACS_P_RES_AEID                                                  |
+| Type of value  | long                                                              |
+| Legal values   | any integer value                                                 |
+| Default value  | none                                                              |
+| Description    | This parameter indicates the responding AE invocation identifier. |
+
+**Table I.4-26/T.180**
+
+|                |                                                                                                |
+|----------------|------------------------------------------------------------------------------------------------|
+| Parameter name | X_ACS_P_RES_APT                                                                                |
+| Type of value  | char[]                                                                                         |
+| Legal values   | buffer with user encoded AP title                                                              |
+| Default value  | none                                                                                           |
+| Description    | The parameter identifies the responding AP-title. It must be encoded as ANY single ASN.1 type. |
+
+**Table I.4-27/T.180**
+
+|                |                                                                   |
+|----------------|-------------------------------------------------------------------|
+| Parameter name | X_ACS_P_RES_APID                                                  |
+| Type of value  | long                                                              |
+| Legal values   | any integer value                                                 |
+| Default value  | none                                                              |
+| Description    | This parameter indicates the responding AP invocation identifier. |
+
+**Table I.4-28/T.180**
+
+|                |                                                             |
+|----------------|-------------------------------------------------------------|
+| Parameter name | X_ACS_P_INIT_SYN_POINT                                      |
+| Type of value  | unsigned long                                               |
+| Legal values   | integer value in the range 0 to 999999                      |
+| Default value  | none                                                        |
+| Description    | The parameter identifies the initial synchronization point. |
+
+**Table I.4-29/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
+|----------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_ACS_P_TOKEN                                                                                                                                                                                                                                                                                                                      |                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
+| Type of value  | unsigned long                                                                                                                                                                                                                                                                                                                      |                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
+| Legal values   | X_ACS_PV_DATA_TOK_REQ<br>X_ACS_PV_DATA_TOK_ACP<br>X_ACS_PV_DATA_TOK_ACP_C<br>X_ACS_PV_MIN_TOK_REQ<br>X_ACS_PV_MIN_TOK_ACP<br>X_ACS_PV_MIN_TOK_ACP_C<br>X_ACS_PV_MAJ_TOK_REQ<br>X_ACS_PV_MAJ_TOK_ACP<br>X_ACS_PV_MAJ_TOK_ACP_C                                                                                                      | Data token assigned to requestor side;<br>Data token assigned to acceptor side;<br>Data token assigned to acceptor choice;<br>Synchronize-minor token assigned to requestor side;<br>Synchronize-minor token assigned to acceptor side;<br>Synchronize-minor token assigned to acceptor choice;<br>Major/activity token assigned to requestor side;<br>Major/activity token assigned to acceptor side;<br>Major/activity token assigned to acceptor choice. |
+| Default value  | none                                                                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
+| Description    | This parameter indicates a list of the initial sides to which the available tokens are assigned. The value of the parameter is dependent on X_ACS_P_SUR. Values of the parameter must be given as one or more items OR'ed together (e.g. X_ACS_PV_DATA_TOK_REQ   X_ACS_PV_MAJ_TOK_REQ). Not all combination of values are allowed. |                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
+
+**Table I.4-30/T.180**
+
+|                |                                                                                                                                                                                                                                 |
+|----------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_ACS_P_S_CASUR                                                                                                                                                                                                                 |
+| Type of value  | char[]                                                                                                                                                                                                                          |
+| Legal values   | any sequence of characters, not '\0' terminated. The value is within the range of 0 (zero) up to X_C_MAX_REF octets of characters.                                                                                              |
+| Default value  | none                                                                                                                                                                                                                            |
+| Description    | The parameter indicates the calling session service user reference, which contains the identification of the calling application. It is part of the session connection id, which is used to obviously identify the association. |
+
+**Table I.4-31/T.180**
+
+|                |                                                                                                                                                                                                                               |
+|----------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_ACS_P_S_CDSUR                                                                                                                                                                                                               |
+| Type of value  | char[]                                                                                                                                                                                                                        |
+| Legal values   | any sequence of characters, not '\0' terminated. The value is within the range of 0 (zero) up to X_C_MAX_REF octets of characters.                                                                                            |
+| Default value  | none                                                                                                                                                                                                                          |
+| Description    | The parameter indicates the called session service user reference, which contains the identification of the called application. It is part of the session connection id, which is used to obviously identify the association. |
+
+**Table I.4-32/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                          |
+|----------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_ACS_P_S_CR                                                                                                                                                                                                                                                                                                                                                             |
+| Type of value  | char[]                                                                                                                                                                                                                                                                                                                                                                   |
+| Legal values   | any sequence of characters, not '\0' terminated. The value is within the range of 0 (zero) up to X_C_MAX_REF octets of characters.                                                                                                                                                                                                                                       |
+| Default value  | none                                                                                                                                                                                                                                                                                                                                                                     |
+| Description    | The parameter indicates the common reference, which contains the date and time reference information showing the year, month, day, hour and minute. This time represents the local time at the calling terminal and is intended to represent the time of call origination. It is part of the session connection id, which is used to obviously identify the association. |
+
+**Table I.4-33/T.180**
+
+|                |                                                                                                                                                                                               |
+|----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_ACS_P_S_ARI                                                                                                                                                                                 |
+| Type of value  | char[]                                                                                                                                                                                        |
+| Legal values   | any sequence of characters, not '\0' terminated. The value is within the range of 0 (zero) up to X_C_MAX_ARI octets of characters.                                                            |
+| Default value  | none                                                                                                                                                                                          |
+| Description    | The parameter indicates the additional information, which contains a document reference number. It is part of the session connection id, which is used to obviously identify the association. |
+
+**Table I.4-34/T.180**
+
+|                |                                                                                                                                                                                                                                            |
+|----------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_ACS_P_PROV_REJ                                                                                                                                                                                                                           |
+| Type of value  | unsigned long                                                                                                                                                                                                                              |
+| Legal values   | PV_TRUE<br>PV_FALSE                                                                                                                                                                                                                        |
+| Default value  | PV_FALSE                                                                                                                                                                                                                                   |
+| Description    | The parameter has to be set to PV_TRUE when detecting a syntactical error in the encoded user data or a semantic error in the proposed context definition list. In this case the Presentation will perform a Presentation provider reject. |
+
+#### **I.4.7.3 Services in the connected state**
+
+The ROSE protocol module provides several services in the connected state which are accessible via the XAPI:
+
+- the RO-INVOKE service (request of a remote operation to be performed);
+- the RO-RESULT service (return of the positive reply of a successfully performed operation);
+- the RO-ERROR service (return of the negative reply of a unsuccessfully performed operation);
+- the RO-REJECT-U service (rejection of the request or reply); and
+- the RO-REJECT-P service (information about problem).
+
+While the service endpoint used to access the provider is in state X\_CONNECTED the corresponding service primitives can be passed to the provider or retrieved from the provider with calls of *x\_sndsp()* or *x\_rcvsp()*, respectively.
+
+The ROSE services specify operations which exceed the transfer services of other protocol modules (e.g. pure transfer services in the RTSE, Session or Transport service access points). Transfer services in XAPI sense enable XAPI users to send and receive either normal or expedited data without additional parameters. ROSE operations transfer additional information beside the application data. Due to this reason the functions *x\_sndsp()* and *x\_rcvsp()* are used to send and receive, respectively, ROSE operations.
+
+##### **I.4.7.3.1 RO-INVOKE service**
+
+###### **I.4.7.3.1.1 Service description**
+
+The RO-INVOKE service is used to request the start of a remote operation.
+
+The service elements and their corresponding XAPI functions needed for RO-INVOKE are described in Table I.4-35.
+
+**Table I.4-35/T.180 – Service elements and their corresponding XAPI functions for the invoke service**
+
+| Service Element      | Service element identifier | XAPI function | Description                                                                                                  |
+|----------------------|----------------------------|---------------|--------------------------------------------------------------------------------------------------------------|
+| RO-INVOKE Request    | X_ROS_SP_ROIV_Q            | x_sndsp()     | The RO-INVOKE Request is passed to the provider to send a request to start a remote operation.               |
+| RO-INVOKE Indication | X_ROS_SP_ROIV_I            | x_rcvsp()     | The RO-INVOKE Indication is passed to the provider to receive a request for the start of a remote operation. |
+
+###### I.4.7.3.1.2 Service parameters
+
+Table I.4-36 specifies the parameters of the ROSE Invoke service.
+
+**Table I.4-36/T.180 – Parameters of the Invoke service**
+
+| Parameter                                                                                                                                                                                                                                                                                                                                                                                                  | RO-INVOKE service |                |
+|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------|----------------|
+|                                                                                                                                                                                                                                                                                                                                                                                                            | Request           | Indication     |
+| X_ROS_P_CTXT_ID                                                                                                                                                                                                                                                                                                                                                                                            | M                 | M              |
+| X_ROS_P_INV_ID                                                                                                                                                                                                                                                                                                                                                                                             | M                 | M              |
+| X_ROS_P_LINK_ID                                                                                                                                                                                                                                                                                                                                                                                            | U                 | C (=)          |
+| X_ROS_P_VAL_INT                                                                                                                                                                                                                                                                                                                                                                                            | C (Note 1)        | C (=) (Note 1) |
+| X_ROS_P_VAL_ID                                                                                                                                                                                                                                                                                                                                                                                             | C (Note 1)        | C (=) (Note 1) |
+| NOTE 1 – Either of the parameters X_ROS_P_VAL_INT or X_ROS_P_VAL_ID is present.<br>NOTE 2 – The operation argument is contained in the <i>data</i> buffer of <i>sp_struct</i> of the <i>x_sndsp()</i> resp. <i>x_rcvsp()</i> function.<br>NOTE 3 – The parameter X_ROS_P_CTXT_ID is the presentation context identification which was negotiated in the ACSE connection establishment for the application. |                   |                |
+
+###### I.4.7.3.1.3 Service parameter description
+
+Tables I.4-37 to I.4-41 specify the parameters for the ROSE Invoke services.
+
+**Table I.4-37/T.180**
+
+|                |                                                                                                                   |
+|----------------|-------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_ROS_P_CTXT_ID                                                                                                   |
+| Type of value  | long                                                                                                              |
+| Legal values   | odd integer value                                                                                                 |
+| Default value  | none                                                                                                              |
+| Description    | The parameter indicates the presentation context identification of the application data of the RO-INVOKE service. |
+
+**Table I.4-38/T.180**
+
+|                |                                                                                                                                                                          |
+|----------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_ROS_P_INV_ID                                                                                                                                                           |
+| Type of value  | long                                                                                                                                                                     |
+| Legal values   | any integer value                                                                                                                                                        |
+| Default value  | none                                                                                                                                                                     |
+| Description    | The parameter identifies the request of a RO-INVOKE service and is used to correlate this request with the corresponding replies or the invocation of linked operations. |
+
+**Table I.4-39/T.180**
+
+|                |                                                                                                                                                                                                                                         |
+|----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_ROS_P_LINK_ID                                                                                                                                                                                                                         |
+| Type of value  | long                                                                                                                                                                                                                                    |
+| Legal values   | any integer value                                                                                                                                                                                                                       |
+| Default value  | none                                                                                                                                                                                                                                    |
+| Description    | The parameter identifies a child-operation and the parameter identifies the invocation of the linked parent-operation. The value is that of the X_ROS_P_INV_ID parameter of the RO-INVOKE indication primitive of the parent-operation. |
+
+**Table I.4-40/T.180**
+
+|                |                                                                                                                                                                                                                                                             |
+|----------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_ROS_P_VAL_INT                                                                                                                                                                                                                                             |
+| Type of value  | long                                                                                                                                                                                                                                                        |
+| Legal values   | any integer value                                                                                                                                                                                                                                           |
+| Default value  | none                                                                                                                                                                                                                                                        |
+| Description    | The parameter indicates the identifier of the operation to be invoked. As the identifier of the operation may either be an integer value or an object identifier, either this parameter (X_ROS_P_VAL_INT) or the parameter (X_ROS_P_VAL_ID) may be present. |
+
+**Table I.4-41/T.180**
+
+|                |                                                                                                                                                                                                                                                             |
+|----------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_ROS_P_VAL_ID                                                                                                                                                                                                                                              |
+| Type of value  | long[]                                                                                                                                                                                                                                                      |
+| Legal values   | Values must be given as a sequence of values in the decimal integer format that are separated by blanks and enclosed in braces (NumberForm of ASN.1 Object Identifier).                                                                                     |
+| Default value  | none                                                                                                                                                                                                                                                        |
+| Description    | The parameter indicates the identifier of the operation to be invoked. As the identifier of the operation may either be an integer value or an object identifier, either this parameter (X_ROS_P_VAL_ID) or the parameter (X_ROS_P_VAL_INT) may be present. |
+
+##### I.4.7.3.2 RO-RESULT service
+
+###### I.4.7.3.2.1 Service description
+
+The RO-RESULT service is used to reply to a previous RO-INVOKE service in the case of a successfully performed operation.
+
+The service elements and their corresponding XAPI functions needed for RO-RESULT are described in Table I.4-42.
+
+**Table I.4-42/T.180 – Service elements and their corresponding XAPI functions for the Result service**
+
+| Service element      | Service element identifier | XAPI function | Description                                                                                                                                        |
+|----------------------|----------------------------|---------------|----------------------------------------------------------------------------------------------------------------------------------------------------|
+| RO-RESULT Request    | X_ROS_SP_RORE_Q            | x_sndsp()     | The RO-RESULT Request is passed to the provider to send a reply to a previous RO_INVOKE service in the case of a successfully performed operation. |
+| RO-RESULT Indication | X_ROS_SP_RORE_I            | x_rcvsp()     | The RO-RESULT Indication is generated by the provider to indicate the reply of a successfully performed operation.                                 |
+
+###### I.4.7.3.2.2 Service parameters
+
+Table I.4-43 specifies the parameters of the RO-RESULT service.
+
+**Table I.4-43/T.180 – Parameters of the Result service**
+
+| Parameter                                                                                                                                                        | RO-Result service |            |
+|------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------|------------|
+|                                                                                                                                                                  | Request           | Indication |
+| X_ROS_P_CTXT_ID                                                                                                                                                  | M                 | M          |
+| X_ROS_P_INV_ID                                                                                                                                                   | M                 | M (=)      |
+| X_ROS_P_VAL_INT                                                                                                                                                  | U                 | C (=)      |
+| X_ROS_P_VAL_ID                                                                                                                                                   | U                 | C (=)      |
+| NOTE 1 – The operation result is contained in the <i>data</i> buffer of <i>sp_struct</i> of the <i>x_sndsp()</i> resp. <i>x_rcvsp()</i> function.                |                   |            |
+| NOTE 2 – The parameter X_ROS_P_CTXT_ID is the presentation context identification which was negotiated in the ACSE connection establishment for the application. |                   |            |
+
+###### I.4.7.3.2.3 Service parameter description
+
+Tables I.4-44 to I.4-47 list the parameters for the RO-RESULT services.
+
+**Table I.4-44/T.180**
+
+|                |                                                                                                                   |
+|----------------|-------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_ROS_P_CTXT_ID                                                                                                   |
+| Type of value  | long                                                                                                              |
+| Legal values   | odd integer value                                                                                                 |
+| Default value  | none                                                                                                              |
+| Description    | The parameter indicates the presentation context identification of the application data of the RO-RESULT service. |
+
+**Table I.4-45/T.180**
+
+|                |                                                                                                                                                      |
+|----------------|------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_ROS_P_INV_ID                                                                                                                                       |
+| Type of value  | long                                                                                                                                                 |
+| Legal values   | any integer value                                                                                                                                    |
+| Default value  | none                                                                                                                                                 |
+| Description    | The parameter identifies the corresponding RO-INVOKE service. The value is that of the corresponding RO-INVOKE indication service (X_ROS_SP_ROIV_Q). |
+
+**Table I.4-46/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                                                              |
+|----------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_ROS_P_VAL_INT                                                                                                                                                                                                                                                                                                                                                                                                                              |
+| Type of value  | long                                                                                                                                                                                                                                                                                                                                                                                                                                         |
+| Legal values   | any integer value                                                                                                                                                                                                                                                                                                                                                                                                                            |
+| Default value  | none                                                                                                                                                                                                                                                                                                                                                                                                                                         |
+| Description    | The parameter indicates the identifier of an invoked and successfully performed operation. The value is that of the corresponding RO-INVOKE indication service (X_ROS_SP_ROIV_I) and is only present if application data are available on this service. As the identifier of the operation may either be an integer value or an object identifier, either this parameter (X_ROS_P_VAL_INT) or the parameter (X_ROS_P_VAL_ID) may be present. |
+
+**Table I.4-47/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                                                              |
+|----------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_ROS_P_VAL_ID                                                                                                                                                                                                                                                                                                                                                                                                                               |
+| Type of value  | long[]                                                                                                                                                                                                                                                                                                                                                                                                                                       |
+| Legal values   | Values must be given as a sequence of values in the decimal integer format that are separated by blanks and enclosed in braces (NumberForm of ASN.1 Object Identifier).                                                                                                                                                                                                                                                                      |
+| Default value  | none                                                                                                                                                                                                                                                                                                                                                                                                                                         |
+| Description    | The parameter indicates the identifier of an invoked and successfully performed operation. The value is that of the corresponding RO-INVOKE indication service (X_ROS_SP_ROIV_I) and is only present if application data are available on this service. As the identifier of the operation may either be an integer value or an object identifier, either this parameter (X_ROS_P_VAL_ID) or the parameter (X_ROS_P_VAL_INT) may be present. |
+
+##### **I.4.7.3.3 RO-ERROR service**
+
+###### **I.4.7.3.3.1 Service description**
+
+The RO-ERROR service is used to reply to a previous RO-INVOKE service in the case of an unsuccessfully performed operation.
+
+The service elements and their corresponding XAPI functions needed for RO-ERROR are described in Table I.4-48.
+
+**Table I.4-48/T.180 – Service elements and their corresponding XAPI functions for the Error service**
+
+| Service element     | Service element identifier | XAPI function | Description                                                                                                                                          |
+|---------------------|----------------------------|---------------|------------------------------------------------------------------------------------------------------------------------------------------------------|
+| RO-ERROR Request    | X_ROS_SP_ROER_Q            | x_sndsp()     | The RO-ERROR Request is passed to the provider to send a reply to a previous RO-INVOKE service in the case of an unsuccessfully performed operation. |
+| RO-ERROR Indication | X_ROS_SP_ROER_I            | x_rcvsp()     | The RO-RESULT Indication is generated by the provider to indicate the reply of an unsuccessfully performed operation.                                |
+
+###### I.4.7.3.3.2 Service parameters
+
+Table I.4-49 specifies the parameters of the RO-ERROR service.
+
+**Table I.4-49/T.180 – Parameters of the Error service**
+
+| Parameter                                                                                                                                                        | RO-ERROR service |                |
+|------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------|----------------|
+|                                                                                                                                                                  | Request          | Indication     |
+| X_ROS_P_CTXT_ID                                                                                                                                                  | M                | M              |
+| X_ROS_P_INV_ID                                                                                                                                                   | M                | M (=)          |
+| X_ROS_P_VAL_INT                                                                                                                                                  | C (Note 1)       | C (=) (Note 1) |
+| X_ROS_P_VAL_ID                                                                                                                                                   | C (Note 1)       | C(=) (Note 1)  |
+| NOTE 1 – Either of the parameters X_ROS_P_VAL_INT or X_ROS_P_VAL_ID is present.                                                                                  |                  |                |
+| NOTE 2 – The operation parameter is contained in the <i>data</i> buffer of <i>sp_struct</i> of the <i>x_sndsp()</i> resp. <i>x_rcvsp()</i> function.             |                  |                |
+| NOTE 3 – The parameter X_ROS_P_CTXT_ID is the presentation context identification which was negotiated in the ACSE connection establishment for the application. |                  |                |
+
+###### I.4.7.3.3.3 Service parameter description
+
+Tables I.4-50 to I.4-53 list the parameters for the RO-ERROR services.
+
+**Table I.4-50/T.180**
+
+|                |                                                                                                                  |
+|----------------|------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_ROS_P_CTXT_ID                                                                                                  |
+| Type of value  | long                                                                                                             |
+| Legal values   | odd integer value                                                                                                |
+| Default value  | none                                                                                                             |
+| Description    | The parameter indicates the presentation context identification of the application data of the RO-ERROR service. |
+
+**Table I.4-51/T.180**
+
+|                |                                                                                                                                                      |
+|----------------|------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_ROS_P_INV_ID                                                                                                                                       |
+| Type of value  | long                                                                                                                                                 |
+| Legal values   | any integer value                                                                                                                                    |
+| Default value  | none                                                                                                                                                 |
+| Description    | The parameter identifies the corresponding RO-INVOKE service. The value is that of the corresponding RO-INVOKE indication service (X_ROS_SP_ROIV_Q). |
+
+**Table I.4-52/T.180**
+
+|                |                                                                                                                                                                                                                                                                        |
+|----------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_ROS_P_VAL_INT                                                                                                                                                                                                                                                        |
+| Type of value  | long                                                                                                                                                                                                                                                                   |
+| Legal values   | any integer value                                                                                                                                                                                                                                                      |
+| Default value  | none                                                                                                                                                                                                                                                                   |
+| Description    | The parameter identifies the error that occurred during the execution of the operation. As the identifier of the error may either be an integer value or an object identifier, either this parameter (X_ROS_P_VAL_INT) or the parameter X_ROS_P_VAL_ID may be present. |
+
+**Table I.4-53/T.180**
+
+|                |                                                                                                                                                                                                                                                                        |
+|----------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_ROS_P_VAL_ID                                                                                                                                                                                                                                                         |
+| Type of value  | long[]                                                                                                                                                                                                                                                                 |
+| Legal values   | Values must be given as a sequence of values in the decimal integer format that are separated by blanks and enclosed in braces (NumberForm of ASN.1 Object Identifier).                                                                                                |
+| Default value  | none                                                                                                                                                                                                                                                                   |
+| Description    | The parameter identifies the error that occurred during the execution of the operation. As the identifier of the error may either be an integer value or an object identifier, either this parameter (X_ROS_P_VAL_INT) or the parameter X_ROS_P_VAL_ID may be present. |
+
+##### **I.4.7.3.4 RO-REJECT-U service**
+
+###### **I.4.7.3.4.1 Service description**
+
+The RO-REJECT-U service is used by a ROSE user to reject a request (RO-INVOKE service) or a reply (RO-RESULT, RO-ERROR services) of the other ROSE user if it has detected a problem.
+
+The service elements and their corresponding XAPI functions needed for RO-REJECT-U are described in Table I.4-54.
+
+**Table I.4-54/T.180 – Service elements and their corresponding XAPI functions for the Reject-U service**
+
+| Service element        | Service element identifier | XAPI function | Description                                                                                                                                                                   |
+|------------------------|----------------------------|---------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| RO-REJECT-U Request    | X_ROS_SP_ROREJU_Q          | x_sndsp()     | The RO-REJECT-U Request is passed to the provider to send a rejection to a previous RO-INVOKE, RO-RESULT or RO-ERROR service if a problem has been detected by the ROSE user. |
+| RO-REJECT-U Indication | X_ROS_SP_ROREJU_I          | x_rcvsp()     | The RO-REJECT-U Indication is generated by the provider to indicate a rejection of a previous RO-INVOKE, RO-RESULT or RO-ERROR service.                                       |
+
+###### I.4.7.3.4.2 Service parameters
+
+Table I.4-55 specifies the parameters of the RO-REJECT-U service.
+
+**Table I.4-55/T.180 – Parameters of the Checkpoint service**
+
+| Parameter                                                                                                                                                      | RO-REJECT-U service |            |
+|----------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------|------------|
+|                                                                                                                                                                | Request             | Indication |
+| X_ROS_P_INV_ID                                                                                                                                                 | U                   | C (=)      |
+| X_ROS_P_CTXT_ID                                                                                                                                                | M                   | M          |
+| X_ROS_P_REJ_REAS                                                                                                                                               | M                   | M (=)      |
+| NOTE – The parameter X_ROS_P_CTXT_ID is the presentation context identification which was negotiated in the ACSE connection establishment for the application. |                     |            |
+
+###### I.4.7.3.4.3 Service parameter description
+
+Tables I.4-56 to I.4-58 list the parameters for the RO-REJECT-U service.
+
+**Table I.4-56/T.180**
+
+|                |                                                                                                                                                      |
+|----------------|------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_ROS_P_INV_ID                                                                                                                                       |
+| Type of value  | long                                                                                                                                                 |
+| Legal values   | any integer value                                                                                                                                    |
+| Default value  | none                                                                                                                                                 |
+| Description    | The parameter identifies the corresponding RO-INVOKE service. The value is that of the corresponding RO-INVOKE indication service (X_ROS_SP_ROIV_Q). |
+
+**Table I.4-57/T.180**
+
+|                |                                                                                                         |
+|----------------|---------------------------------------------------------------------------------------------------------|
+| Parameter name | X_ROS_P_CTXT_ID                                                                                         |
+| Type of value  | long                                                                                                    |
+| Legal values   | odd integer value                                                                                       |
+| Default value  | none                                                                                                    |
+| Description    | The parameter indicates the presentation context identification of the data of the RO-REJECT-U service. |
+
+**Table I.4-58/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
+|----------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_ROS_P_REJ_REAS                                                                                                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
+| Type of value  | unsigned long                                                                                                                                                                                                                                                                                                                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
+| Legal values   | X_ROS_PV_DUP_INV<br>X_ROS_PV_UNREC_OP<br>X_ROS_PV_MIST_ARG<br>X_ROS_PV_RES_LIM<br>X_ROS_PV_INIT_REL<br>X_ROS_PV_UNREC_LINKID<br>X_ROS_PV_UNEXP_LINKRES<br>X_ROS_PV_UNEXP_CHDOP<br>X_ROS_PV_RE_UNREC_INV<br><br>X_ROS_PV_UNEXP_RERES<br>X_ROS_PV_MIST_RES<br>X_ROS_PV_ER_UNREC_INV<br><br>X_ROS_PV_UNEXP_ERRES<br>X_ROS_PV_UNREC_ER<br>X_ROS_PV_UNEXP_ER<br>X_ROS_PV_MIST_PAR | Duplication-invocation;<br>Unrecognized operation;<br>Mistyped argument;<br>Resource limitation;<br>Initiator-releasing;<br>Unrecognized linked identifier;<br>Unexpected link-response;<br>Unexpected child operation;<br>Unrecognized invocation (reject of RO_RESULT);<br><br>Unexpected result response;<br>Mistyped result;<br>Unrecognized invocation (reject of RO-ERROR);<br><br>Unexpected error response;<br>Unrecognized error;<br>Unexpected error;<br>Mistyped parameter. |
+| Default value  | none                                                                                                                                                                                                                                                                                                                                                                         |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
+| Description    | The parameter specifies the reason for rejection.                                                                                                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
+
+##### **I.4.7.3.5 RO-REJECT-P service**
+
+###### **I.4.7.3.5.1 Service description**
+
+The RO-REJECT-P service is used to advise a ROSE user of a problem detected by a ROSE provider.
+
+The service elements and their corresponding XAPI functions needed for RO-REJECT-P are described in Table I.4-59.
+
+**Table I.4-59/T.180 – Service elements and their corresponding XAPI functions for the Reject-P service**
+
+| Service element        | Service element identifier | XAPI function | Description                                                                                                                                                                                          |
+|------------------------|----------------------------|---------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| RO-REJECT-P Indication | X_ROS_SP_ROREJP_I          | x_rcvsp()     | The RO-REJECT-P Indication is generated by the provider to indicate a provider rejection to a previous RO-INVOKE, RO-RESULT or RO-ERROR service if a problem has been detected by the ROSE provider. |
+
+###### I.4.7.3.5.2 Service parameters
+
+Table I.4-60 specifies the parameters of the RO-REJECT-P service.
+
+**Table I.4-60/T.180 – Parameters of the Reject-P service**
+
+| Parameter                                                                                                                                                                                                                                                                                                                                                                                | RO-REJECT-P Service |
+|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------|
+|                                                                                                                                                                                                                                                                                                                                                                                          | Indication          |
+| X_ROS_P_INV_ID                                                                                                                                                                                                                                                                                                                                                                           | C                   |
+| X_ROS_P_PREJ_REAS                                                                                                                                                                                                                                                                                                                                                                        | M                   |
+| NOTE – Due to the fact that the Linked-Id and Invoke-Id are not examined by the ROSE provider and the application data of the ROSE APDUs are already encoded by the XAPI user, the ROSE provider will accept all ROSE request service primitives from the XAPI user. Therefore, it is not necessary to support the Returned-parameters parameter of the RO-REJECT-P service at the XAPI. |                     |
+
+###### I.4.7.3.5.3 Service parameter description
+
+Tables I.4-61 to I.4-62 list the parameters for the RO-REJECT-P service.
+
+**Table I.4-61/T.180**
+
+|                |                                                                                                                                                      |
+|----------------|------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_ROS_P_INV_ID                                                                                                                                       |
+| Type of value  | long                                                                                                                                                 |
+| Legal values   | any integer value                                                                                                                                    |
+| Default value  | none                                                                                                                                                 |
+| Description    | The parameter identifies the corresponding invocation. The value is that of the corresponding RO-INVOKE, RO-RESULT, RO-ERROR or RO-REJECT-U service. |
+
+**Table I.4-62/T.180**
+
+|                |                                                                                                                      |
+|----------------|----------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_ROS_P_PREJ_REAS                                                                                                    |
+| Type of value  | unsigned long                                                                                                        |
+| Legal values   | X_ROS_PV_UNREC_APDU unrecognized APDU<br>X_ROS_PV_MIST_APDU mistyped APDU<br>X_ROS_PV_BAD_STRU badly structured APDU |
+| Default value  | none                                                                                                                 |
+| Description    | The parameter specifies the reason for rejection.                                                                    |
+
+##### **I.4.7.3.6 State transition tables/diagrams**
+
+To handle the ROSE services while the service endpoint is in state X\_CONNECTED, the ROSE service provider distinguishes no additional states.
+
+#### **I.4.7.4 Connection Release service**
+
+##### **I.4.7.4.1 Service description**
+
+The orderly release service allows either ACSE service user to release the ACSE connection in an orderly manner. This is done cooperatively between the two ACSE service users without the loss of data after all in-transit data have been delivered and accepted by both ACSE service users.
+
+The service elements and their corresponding XAPI functions needed for ACSE Connection Release service are described in Table I.4-63.
+
+**Table I.4-63/T.180 – Service elements and their corresponding XAPI functions for the Connection Release service**
+
+| <b>Service element</b> | <b>XAPI function</b> | <b>Description</b>                                                                                                                                                                                             |
+|------------------------|----------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Release Request        | x_relreq()           | The Release Request is passed to the provider to request a normal ACSE connection release.                                                                                                                     |
+| Release Indication     | x_relind()           | The Release Indication is generated by the provider to indicate the orderly release of a ACSE connection by the remote side.                                                                                   |
+| Release Response       | x_relrsp()           | The Release Response is passed to the provider as reaction to a previously received Release Indication as positive response.                                                                                   |
+| Release Confirmation   | x_relconf()          | The Release Confirmation is generated by the provider as positive confirmation of a normal ACSE release.                                                                                                       |
+| End Indication         | x_revend()           | The End Indication is generated by the service provider to indicate that the service provider is ready to establish a new connection. In addition, it contains some information about the released connection. |
+
+##### I.4.7.4.2 Service parameters
+
+Table I.4-64 specifies the parameters of the ACSE Connection Release service.
+
+**Table I.4-64/T.180 – Parameters of the Connection Release service**
+
+| Parameter       | Release service |            |          |              |                |
+|-----------------|-----------------|------------|----------|--------------|----------------|
+|                 | Request         | Indication | Response | Confirmation | End Indication |
+| X_ACS_P_REASON  | U               | C (=)      | U        | C (=)        |                |
+| X_P_CONN_TIME   |                 |            |          |              | M              |
+| X_P_DISC_TIME   |                 |            |          |              | M              |
+| X_P_CHARGE      |                 |            |          |              | C              |
+| X_P_DISC_REASON |                 |            |          |              | C              |
+
+##### I.4.7.4.3 Service parameter description
+
+Tables I.4-65 to I.4-69 define the parameter for the Connection Release service.
+
+**Table I.4-65/T.180**
+
+|                |                                                                                                                                                                                                                                                       |
+|----------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_ACS_P_REASON                                                                                                                                                                                                                                        |
+| Type of value  | unsigned long                                                                                                                                                                                                                                         |
+| Legal values   | When used on the Request or Response primitive:<br>X_ACS_PV_NORMAL Normal;<br>X_ACS_PV_USDEF User defined.<br>When used on the Request primitive:<br>X_ACS_PV_URGENT Urgent.<br>When used on the reponse primitive:<br>X_ACS_PV_NOT_FIN Not finished. |
+| Default value  | none                                                                                                                                                                                                                                                  |
+| Description    | The parameter indicates the general urgency of the Release Request and in the Release Reponse information about the Release Request.                                                                                                                  |
+
+**Table I.4-66/T.180**
+
+|                |                                                          |
+|----------------|----------------------------------------------------------|
+| Parameter name | X_P_CONN_TIME                                            |
+| Type of value  | unsigned long                                            |
+| Legal values   | the time in seconds since 01.01.1970 00:00:00 GMT        |
+| Default value  | none                                                     |
+| Description    | This parameter contains the time of physical connection. |
+
+**Table I.4-67/T.180**
+
+|                |                                                                                                                                                                      |
+|----------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_P_DISC_TIME                                                                                                                                                        |
+| Type of value  | unsigned long                                                                                                                                                        |
+| Legal values   | the time in seconds since 01.01.1970 00:00:00 GMT                                                                                                                    |
+| Default value  | none                                                                                                                                                                 |
+| Description    | This parameter contains the time of physical disconnection. If X_P_CONN_TIME and X_P_DISCON_TIME were both set to zero, no physical connection could be established. |
+
+**Table I.4-68/T.180**
+
+|                |                                                                                                                                                          |
+|----------------|----------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_P_CHARGE                                                                                                                                               |
+| Type of value  | unsigned long                                                                                                                                            |
+| Legal values   | any number                                                                                                                                               |
+| Default value  | zero                                                                                                                                                     |
+| Description    | This parameter contains, if available, the charging unit of the connection. It is only set if both network and network connection provide this facility. |
+
+**Table I.4-69/T.180**
+
+|                |                                                                                                                         |
+|----------------|-------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_P_DISC_REASON                                                                                                         |
+| Type of value  | unsigned long                                                                                                           |
+| Legal values   | The values are directly mapped from the underlying hardware. See the hardware documentation to get further information. |
+| Default value  | zero                                                                                                                    |
+| Description    | This parameter contains, if available, the disconnection reason.                                                        |
+
+#### **I.4.7.5 Connection Abort service**
+
+##### **I.4.7.5.1 Service description**
+
+The abort service provides the means by which either ACSE service user or ACSE itself can instantaneously release the ACSE connection and have the other ACSE service user informed of the release. Use of this service will cause loss of undelivered data.
+
+The *origination* parameter of the *x\_snddis()* and *x\_rcvdis()* function must be set to ABORT in this case.
+
+The service elements and their corresponding XAPI functions needed for user abort of ACSE connection are described in the Table I.4-70.
+
+**Table I.4-70/T.180 – Service elements and their corresponding XAPI functions for the Connection Abort service**
+
+| Service element  | XAPI function | Description                                                                                                                                                                                                    |
+|------------------|---------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Abort Request    | x_snddis()    | The Abort Request is passed to the provider to request an abnormal ACSE connection release.                                                                                                                    |
+| Abort Indication | x_rcvdis()    | The Abort Indication is generated by the provider to indicate the abnormal release of an ACSE connection due to ACSE user.                                                                                     |
+| End Indication   | x_rcvend()    | The End Indication is generated by the service provider to indicate that the service provider is ready to establish a new connection. In addition, it contains some information about the released connection. |
+
+##### **I.4.7.5.2 Service parameters**
+
+Table I.4-71 specifies the ACSE service elements and their parameters needed for abortive ACSE release.
+
+NOTE – If the Abort service primitive contains user data, additional information is necessary to qualify the user data. When relying on the XAPI ACSE/ROSE service provider, the coding/decoding of ACSE user data has to be done by the ACSE service user.
+
+If the abort service primitive contains user data and the ACSE Connect Request service primitive contained a context definition list, a so-called "presentation context identifier list" (see also 6.4.2/[X.226]) has to be specified in the abort service primitive. It consists of a list of pairs X\_ACS\_P\_CTXT\_ID (representing a presentation context id) and X\_ACS\_P\_TS (representing the name of the transfer syntax used for the coding of the specified presentation context).
+
+The list has to contain one pair for each presentation context used in the user data parameter. The second parameter of such a pair is optional; if omitted, the default value representing X.209 is used. If the transfer syntax parameter is available, it has to follow immediately the corresponding context id parameter. Furthermore, the elements contained in the list have to follow immediately one another.
+
+**Table I.4-71/T.180 – Parameters of the Connection Abort service**
+
+| Parameter       | Abort service |            |                |
+|-----------------|---------------|------------|----------------|
+|                 | Request       | Indication | End Indication |
+| X_ACS_P_AB_SRC  |               | C          |                |
+| X_ACS_P_CTXT_ID | C             | C (=)      |                |
+| X_ACS_P_TS      | C             | C (=)      |                |
+| X_P_CONN_TIME   |               |            | M              |
+| X_P_DISC_TIME   |               |            | M              |
+| X_P_CHARGE      |               |            | C              |
+| X_P_DISC_REASON |               |            | C              |
+
+##### I.4.7.5.3 Service parameter description
+
+Tables I.4-72 to I.4-78 list the parameters for the user abortive ACSE abort service.
+
+**Table I.4-72/T.180**
+
+|                |                                                                    |
+|----------------|--------------------------------------------------------------------|
+| Parameter name | X_ACS_P_AB_SRC                                                     |
+| Type of value  | unsigned long                                                      |
+| Legal values   | X_ACS_PV_SU ACSE service user<br>X_ACS_PV_SP ACSE service provider |
+| Default value  | X_ACS_PV_SU                                                        |
+| Description    | The parameter indicates the initiating source of the abort.        |
+
+**Table I.4-73/T.180**
+
+|                |                                                                                                                                                                                      |
+|----------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_ACS_P_CTXT_ID                                                                                                                                                                      |
+| Type of value  | unsigned long                                                                                                                                                                        |
+| Legal values   | identifier of presentation contexts contained in the user data                                                                                                                       |
+| Default value  | none                                                                                                                                                                                 |
+| Description    | This parameter identifies one of the presentation contexts used in the user data parameter of the service primitive. For each used presentation context, a value has to be provided. |
+
+**Table I.4-74/T.180**
+
+|                |                                                                                                                                                                                                   |
+|----------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_ACS_P_TS                                                                                                                                                                                        |
+| Type of value  | long[]                                                                                                                                                                                            |
+| Legal values   | Values must be given as a sequence of long values which form an object identifier identifying a transfer syntax.                                                                                  |
+| Default value  | {2, 1, 1} the object identifier of transfer syntax X.209                                                                                                                                          |
+| Description    | The parameter indicates the transfer syntax name belonging to the previously specified presentation context identifier. If available, it has to follow immediately the parameter X_ACS_P_CTXT_ID. |
+
+**Table I.4-75/T.180**
+
+|                |                                                          |
+|----------------|----------------------------------------------------------|
+| Parameter name | X_P_CONN_TIME                                            |
+| Type of value  | unsigned long                                            |
+| Legal values   | the time in seconds since 01.01.1970 00:00:00 GMT        |
+| Default value  | none                                                     |
+| Description    | This parameter contains the time of physical connection. |
+
+**Table I.4-76/T.180**
+
+|                |                                                                                                                                                                 |
+|----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_P_DISC_TIME                                                                                                                                                   |
+| Type of value  | unsigned long                                                                                                                                                   |
+| Legal values   | the time in seconds since 01.01.1970 00:00:00 GMT                                                                                                               |
+| Default value  | None                                                                                                                                                            |
+| Description    | this parameter contains the time of physical disconnection. If X_P_CONN_TIME and X_P_DISCON_TIME both set to zero, no physical connection could be established. |
+
+**Table I.4-77/T.180**
+
+|                |                                                                                                                                                          |
+|----------------|----------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_P_CHARGE                                                                                                                                               |
+| Type of value  | unsigned long                                                                                                                                            |
+| Legal values   | any number                                                                                                                                               |
+| Default value  | zero                                                                                                                                                     |
+| Description    | This parameter contains, if available, the charging unit of the connection. It is only set if both network and network connection provide this facility. |
+
+**Table I.4-78/T.180**
+
+|                |                                                                                                                         |
+|----------------|-------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_P_DISC_REASON                                                                                                         |
+| Type of value  | unsigned long                                                                                                           |
+| Legal values   | The values are directly mapped from the underlying hardware. See the hardware documentation to get further information. |
+| Default value  | zero                                                                                                                    |
+| Description    | This parameter contains, if available, the disconnection reason.                                                        |
+
+#### **I.4.7.6 Connection Provider Abort service**
+
+##### **I.4.7.6.1 Service description**
+
+The provider abort service provides the means by which the ACSE protocol modules may indicate the release of the connection for reason below to the ACSE service provider.
+
+The *origination* parameter of the *x\_snddis()* and *x\_rcvdis()* function must be set to PROVIDER\_ABORT in this case.
+
+The provider abort service elements and their corresponding XAPI functions are described in Table I.4-79.
+
+**Table I.4-79/T.180 – Service elements and their corresponding XAPI functions  
+for the Connection Provider Abort service**
+
+| Service element           | XAPI function | Description                                                                                                                                                                                                    |
+|---------------------------|---------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Provider Abort Indication | x_rcvdis()    | The Provider Abort Indication service is generated by the provider to indicate the abnormal release of an ACSE connection by the ACSE provider.                                                                |
+| End Indication            | x_rcvend()    | The End Indication is generated by the service provider to indicate that the service provider is ready to establish a new connection. In addition, it contains some information about the released connection. |
+
+##### **I.4.7.6.2 Service parameters**
+
+Table I.4-80 specifies the parameters needed for provider abortive ACSE release.
+
+**Table I.4-80/T.180 – Parameters of the Connection Provider Abort service**
+
+| Parameter        | Provider Abort service |                |
+|------------------|------------------------|----------------|
+|                  | Indication             | End Indication |
+| X_ACS_P_PRO_REAS | C                      |                |
+| X_P_CONN_TIME    |                        | M              |
+| X_P_DISC_TIME    |                        | M              |
+| X_P_CHARGE       |                        | C              |
+| X_P_DISC_REASON  |                        | C              |
+
+##### **I.4.7.6.3 Service parameter description**
+
+Tables I.4-81 to I.4-85 list the parameters for the provider abortive ACSE release service.
+
+**Table I.4-81/T.180**
+
+|                |                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                                                     |
+|----------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_ACS_P_PRO_REAS                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                     |
+| Type of value  | unsigned long                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                                                     |
+| Legal values   | X_ACS_PV_NOT_SPEC<br>X_ACS_PV_UNREC_PPDU<br>X_ACS_PV_UNEXP_PPDU<br>X_ACS_PV_UNEXP_SSP<br>X_ACS_PV_UNREC_PAR<br>X_ACS_PV_UNEXP_PAR<br>X_ACS_PV_INV_PARVAL<br>X_ACS_PV_TRANS_DIS<br>X_ACS_PV_SESS_PROTERR<br>X_ACS_PV_SESS_PICS | Reason not specified;<br>Unrecognized PPDU;<br>Unexpected PPDU;<br>Unexpected session service primitive;<br>Unrecognized PPDU parameter;<br>Unexpected PPDU parameter;<br>Invalid PPDU parameter value;<br>Transport connection aborted;<br>Session protocol error;<br>Session unable to support requested feature. |
+| Default value  | X_ACS_PV_NOT_SPEC                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                                                                     |
+| Description    | The parameter indicates the reason for the termination of the association.                                                                                                                                                    |                                                                                                                                                                                                                                                                                                                     |
+
+**Table I.4-82/T.180**
+
+|                |                                                          |
+|----------------|----------------------------------------------------------|
+| Parameter name | X_P_CONN_TIME                                            |
+| Type of value  | unsigned long                                            |
+| Legal values   | the time in seconds since 01.01.1970 00:00:00 GMT        |
+| Default value  | none                                                     |
+| Description    | This parameter contains the time of physical connection. |
+
+**Table I.4-83/T.180**
+
+|                |                                                                                                                                                                 |
+|----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_P_DISC_TIME                                                                                                                                                   |
+| Type of value  | unsigned long                                                                                                                                                   |
+| Legal values   | the time in seconds since 01.01.1970 00:00:00 GMT                                                                                                               |
+| Default value  | none                                                                                                                                                            |
+| Description    | This parameter contains the time of physical disconnection. If X_P_CONN_TIME and X_P_DISCON_TIME both set to zero, no physical connection could be established. |
+
+**Table I.4-84/T.180**
+
+|                |                                                                                                                                                          |
+|----------------|----------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_P_CHARGE                                                                                                                                               |
+| Type of value  | unsigned long                                                                                                                                            |
+| Legal values   | any number                                                                                                                                               |
+| Default value  | zero                                                                                                                                                     |
+| Description    | This parameter contains, if available, the charging unit of the connection. It is only set if both network and network connection provide this facility. |
+
+**Table I.4-85/T.180**
+
+|                |                                                                                                                         |
+|----------------|-------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_P_DISC_REASON                                                                                                         |
+| Type of value  | unsigned long                                                                                                           |
+| Legal values   | The values are directly mapped from the underlying hardware. See the hardware documentation to get further information. |
+| Default value  | zero                                                                                                                    |
+| Description    | This parameter contains, if available, the disconnection reason.                                                        |
+
+#### **I.4.7.7 Usage of XAPI functions**
+
+This subclause provides some protocol-specific remarks to the use of the XAPI functions. The functions are mentioned in alphabetical order.
+
+- x\_sndsp()* This XAPI function contains in the *data* buffer of *sp\_struct* the encoded *argument*, *result* and *parameter* components of the ROSE APDUs in encoded form.
+- x\_rcvsp()* This XAPI function contains in the *data* buffer of *sp\_struct* the *argument*, *result* and *parameter* components of the ROSE APDUs in encoded format.
+
+#### **I.4.7.8 Tables of error codes**
+
+The XAPI error-level error codes are defined in Annex B.
+
+##### **I.4.7.8.1 CC\_BADVALUE**
+
+If the cause code indicates a parameter error with a bad value, the value of *diagnostic* will contain the erroneous parameter identifier which has been submitted with the XAPI function call that caused the error indication or one of the identifiers X\_ACS\_CTX\_DEF\_LIST, X\_ACS\_CTX\_DEF\_RES\_LIST, X\_ACS\_CTX\_ID\_LIST, if the error occurred within a context definition list, a context definition result list or a context identifier list, respectively.
+
+##### **I.4.7.8.2 CC\_MANDMISS**
+
+If the cause code indicates that a mandatory parameter is missing, the value of *diagnostic* will contain the missing parameter identifier that caused the error indication.
+
+##### **I.4.7.8.3 CC\_BADEVENT**
+
+If the cause code indicates a bad event, the value of *diagnostic* will contain the bad event identifier which has been submitted with the XAPI function call that caused the error indication.
+
+##### **I.4.7.8.4 CC\_UNEXPECT**
+
+If the cause code indicates a unexpected event, the value of *diagnostic* will contain the actual state identifier in which the unexpected event caused the error indication.
+
+##### **I.4.7.8.5 CC\_NOTSUPPORT**
+
+If the cause code indicates an unsupported event, the value of *diagnostic* will contain the identifier of the unsupported event which has been submitted with the XAPI function call that caused the error indication.
+
+##### **I.4.7.8.6 CC\_OTHER**
+
+If the cause code indicates the CC\_OTHER error code, the value of *diagnostic* will contain the identifier which caused the error indication.
+
+## **I.5 XAPI access to a Service Provider for Audio and Video (AV) Control**
+
+This part of Appendix I describes an example of how the service provider can be implemented if an application needs access to the specified service.
+
+### **I.5.1 Scope**
+
+The XAPI, which is an abbreviation for eXtensive Application Programming Interface, is an operating system and language-independent programming interface to general communication services. Detailed information about the XAPI is given in the main part of this Recommendation, which is very important for understanding this appendix.
+
+Which services are made available via the XAPI depends on the installed service providers and not on the XAPI, which only provides the access mechanism.
+
+The AV Codec can be seen as the "heart" of an audiovisual terminal. The service provider enables the XAPI user to:
+
+- establish a connection to a remote communication partner;
+- release or disconnect a previously established connection;
+- control the communication to the remote partner; and
+- control the behaviour of the local AV Codec.
+
+The processing of audio and video signals is solely the task of the AV Codec. The AV Codec Controller only controls this processing. The communication path for the terminal-to-network control signals is provided in the D-channel while the AV communication with the remote entity, the path for the terminal-to-terminal control signals is provided as a single B/H<sub>0</sub>/H<sub>11</sub>/H<sub>12</sub>-channel or multiple B/H<sub>0</sub>-channels.
+
+This part does not refer to a concrete AV Codec, but describes the access to an ideal service provider according to Recommendation H.320 and related Recommendations. A concrete service provider, which is built on a certain AV Codec hardware, need not implement exactly this ideal service provider. Thus, it is necessary to have some release notes for each concrete service provider that explain the differences to the ideal service provider.
+
+Each concrete service provider has to implement all services described throughout this part and their standardized parameters. Note that the set of allowed values for a standardized service parameter may be restricted by a concrete service provider. It should not be necessary to extend the value range of a standardized parameter because it is defined as the maximum possible according to the Recommendations. The non-standardized service parameters described here provide a guideline for the implementation of useful non-standard features in a concrete service provider. They need not be implemented at all and even additional non-standard parameters, not mentioned here, may be implemented. But in order to provide portability of XAPI applications, it is a good idea to follow these guidelines as far as possible in the design of a concrete service provider. (For the same reason XAPI application programmers should not persist in the presence of a certain non-standard parameter.)
+
+### **I.5.2 References**
+
+The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; all users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published.
+
+- [H.221] ITU-T Recommendation H.221 (1997), *Frame structure for a 64 to 1920 kbit/s channel in audiovisual teleservices.*
+- [H.230] ITU-T Recommendation H.230 (1997), *Frame-synchronous control and indication signals for audiovisual systems.*
+- [H.231] ITU-T Recommendation H.231 (1997), *Multipoint control units for audiovisual systems using digital channels up to 1920 Kbit/s.*
+- [H.242] ITU-T Recommendation H.242 (1993), *System for establishing communication between audiovisual terminals using digital channels up to 2 Mbit/s.*
+- [H.243] ITU-T Recommendation H.243 (1997), *Procedures for establishing communication between three or more audiovisual terminals using digital channels up to 1920 Kbit/s.*
+- [H.261] ITU-T Recommendation H.261 (1993), *Video codec for audiovisual services at  $p \times 64$  kbit/s.*
+- [H.320] TU-T Recommendation H.320 (1997), *Narrow-band visual telephone systems and terminal equipment.*
+- [H.331] ITU-T Recommendation H.331 (1993), *Broadcasting type audiovisual multipoint systems and terminal equipment.*
+- [I.430] ITU-T Recommendation I.430 (1995), *Basic user network interface – Layer 1 specification.*
+- [I.431] ITU-T Recommendation I.431 (1993), *Primary rate user network interface – Layer 1 specification.*
+
+### **I.5.3 Definitions**
+
+### **I.5.4 Abbreviations**
+
+This part uses the following abbreviations:
+
+|                 |                                                                      |
+|-----------------|----------------------------------------------------------------------|
+| AC              | Additional Channel                                                   |
+| AV              | Audio and Video                                                      |
+| BAS             | Bit-rate Allocation Signal                                           |
+| C&I             | Control and Indication (H.320)                                       |
+| DSS 1           | Digital Subscriber Signalling System No. 1                           |
+| ECS             | Encryption Control Signal                                            |
+| FAS             | Frame Alignment Signal                                               |
+| H <sub>0</sub>  | Channel consisting of six 64 kbit/s time-slots (384 kbit/s)          |
+| H <sub>11</sub> | Channel consisting of twenty-four 64 kbit/s time-slots (1536 kbit/s) |
+| H <sub>12</sub> | Channel consisting of thirty 64 kbit/s time-slots (1920 kbit/s)      |
+| HSD             | High-Speed Data                                                      |
+| IC              | Initial Channel                                                      |
+| ISDN            | Integrated Services Digital Network                                  |
+| ISO             | International Organization for Standardization                       |
+| LSD             | Low-Speed Data                                                       |
+
+|      |                                                                                                                                                                                                       |
+|------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| MBE  | Multiple Byte Extension                                                                                                                                                                               |
+| MCU  | Multipoint Control Unit                                                                                                                                                                               |
+| MLP  | Multi-Layer Protocol                                                                                                                                                                                  |
+| NSAP | Network Service Access Point                                                                                                                                                                          |
+| OSI  | Open Systems Interconnection                                                                                                                                                                          |
+| PHC  | is used as service identification part in the names defined by the Access to an AV Codec Controller Service. The letters PHC are short for "Physical layer, access to an <b>H</b> -Codec controller". |
+| SBE  | Single Byte Extension                                                                                                                                                                                 |
+| SC   | Service Channel                                                                                                                                                                                       |
+| TS   | Time Slot                                                                                                                                                                                             |
+| XAPI | eXtensive Application Programming Interface                                                                                                                                                           |
+
+### 1.5.5 Conventions
+
+Each service is described via three kinds of tables.
+
+In the first kind of table the service and its service elements are described. It contains a row for each service element of the service (where service element means either request, indication, response, or confirmation) with its corresponding XAPI function and a short description.
+
+In the second kind of table the use of the service primitive parameters within the service elements are described. It contains a row for each service primitive parameter of the service. The service primitive parameter name is stored within the first column; the succeeding columns contain the use of the parameter in the service elements:
+
+|       |                                                                                                                                                                                                                                                                                                                                                                                                                                      |
+|-------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Blank | The service parameter is absent.                                                                                                                                                                                                                                                                                                                                                                                                     |
+| C     | Presence of the service parameter is conditional. Firstly, there may be a condition in the service provider to provide a parameter in an indication or confirmation, secondly, there may be interdependencies between parameters of the same or the preceding service primitive.                                                                                                                                                     |
+| M     | Presence of the service parameter is mandatory.                                                                                                                                                                                                                                                                                                                                                                                      |
+| U     | Presence of the service parameter is a user option. If the user does not specify a value for such a parameter and there is no default value for that parameter, nothing is passed to the service provider. If the user does not specify a value for such a parameter and there is a default value, the default value is passed to the service provider.                                                                              |
+| (=)   | The value of the service parameter is identical to the value of the corresponding service parameter in the preceding service element. In the special case of a parameter, whose presence in the preceding service is a user option, for which a default value is defined, and the parameter was not specified in the preceding service element, the symbol (=) indicates that the parameter value is identical to the default value. |
+
+The third kind of table is used to describe the service primitive parameter containing the type of value and its scope, possible default values and a detailed description. For each service primitive parameter, one description table is given.
+
+A **naming convention** is used throughout the XAPI in order to distinguish between the common functions, identifiers and values, and service-specific identifiers and values. All service-specific settings of the XAPI AV Codec service access are defined within the present part of this appendix and start with **X\_PHC\_** or **x\_phc\_**.
+
+Extended naming conventions:
+
+- SP\_ Service Primitive;
+- P\_ Parameter;
+- PV\_ Parameter Value;
+- O\_ Option;
+- OV\_ Option Value.
+
+### I.5.6 Introduction to the video codec service provider access
+
+Because of the technical progress in video processing and in telecommunication, it is possible to transfer AV data in a high quality in narrow-band networks. Recommendation H.320 and its related Recommendations define inband and outband signalling procedures as well as codings for audio and video data for visual telephone systems. Recommendation H.221 defines the frame structure for 64 to 1920 kbit/s channel in audiovisual services, and Recommendation H.242 defines a system for establishing communication between audiovisual terminals using digital channels up to 2 Mbit/s.
+
+An important requirement of the H.320 series is the compatibility of videophones to ISDN – and analog telephones. All videophones start the connection establishment phase using one B/H<sub>0</sub>/H<sub>11</sub>/H<sub>12</sub>-channel, audio mode G.711 (3.1 kHz, 64 kbit/s). After the connection is established, both terminals exchange their capabilities and change to the best common mode of operation. This initialization procedure is defined in Recommendation H.242. In order to increase bandwidth, additional B/H<sub>0</sub>-channels may be established by the calling terminal. A larger bandwidth allows the improvement of the quality of speech as well as the best quality for the motion image sequences.
+
+Table I.5-1 shows important video communication modes in ISDN according to Recommendations H.221 and H.242:
+
+**Table I.5-1/T.180 – Audio/Video communication modes in ISDN**
+
+| Number of B-channels  | Video        | Audio                       |
+|-----------------------|--------------|-----------------------------|
+| Use of one B-channel  | 46.4 kbit/s  | 16 kbit/s: 3.1 kHz          |
+| Use of two B-channels | 68.8 kbit/s  | 56 kbit/s: 3.1 kHz or 7 kHz |
+|                       | 92.8 kbit/s  | 32 kbit/s: 7 kHz            |
+|                       | 108.8 kbit/s | 16 kbit/s: 3.1 kHz          |
+
+NOTE – The use of two B-channels improves the quality of videophone communications. The video bandwidth of 108.8 kbit/s provides the best quality of picture in ISDN if two B-channels are used.
+
+The XAPI Audio/Video Codec Control Service, as the name already suggests, provides the means to *control* a service provider performing audio/video communication conforming to the requirements of H.320 and its related Recommendations H.221, H.230, H.231, H.242 and H.243.
+
+Service primitives for connection establishment and release as well as for switching the mode of communication (e.g. change bandwidth for the audio data, change number of used lines) or the local receive capabilities are provided.
+
+The audio/video data themselves are actually not passed between XAPI user and service provider via XAPI function calls. These isochronous data streams have to be transferred without any delays between the system components. Commonly available hardware in personal computers does not allow to carry these data fast enough via the bus, therefore they are transferred by directly interconnecting audio/video I/O equipment, AV Codec and network interface.
+
+According to Recommendation H.320 and related Recommendations, the subscribers are also able to initiate a transfer of asynchronous data (e.g. transmission of still images, transmission of group 3 or group 4 facsimile documents) besides audio/video communication. Transfer of asynchronous data is not covered by the restrictions explained above. Therefore, a data transfer service is provided to exchange asynchronous data between the XAPI user and the service provider. The available video bandwidth is decreased by the data transfer rate.
+
+### **I.5.7 Description of the access to the Video Codec Service Provider**
+
+#### **I.5.7.1 Service initialization**
+
+##### **I.5.7.1.1 Creation of a AV Codec Service Access Point with *x\_open()***
+
+A communication endpoint accessing the AV Codec service provider is created when calling the *x\_open()* function with an appropriate service provider identification string. The available identifiers depend on the actual system configuration. In the standard configuration, "X\_PHC\_ISDN" identifies the AV Codec control service provider with ISDN as underlying network.
+
+##### **I.5.7.1.2 Activation of a AV Codec Service Access Point with *x\_bind()***
+
+*x\_bind()* is to be called to activate the AV Codec service endpoint. The function has the task to bind the application's own address to the service endpoint.
+
+##### **I.5.7.1.3 Addresses**
+
+The network address (NSAP) is used to identify the called or calling entity.
+
+###### **I.5.7.1.3.1 Specification of the application's own address**
+
+The own address may be specified in the *own\_address* buffer of the *bind\_struct* passed as argument to the *x\_bind()* function. For a passive application it is returned in the *called\_addr* buffer of the *x\_conind()* function.
+
+For a passive application it is not supported to specify the (own) responding NSAP address in the *address* buffer of the *call\_struct* in the *x\_conrsp()* call, because this value is not transferred by the network.
+
+Note that specification of the application's own protocol address in the *x\_bind()* call is optional. If no address information is specified, it is taken from the XAPI configuration and the actually bound address is returned as output parameter of the *x\_bind()* function. It is strongly recommended to trust in the XAPI configuration and not to specify the own address in the *x\_bind()* call.
+
+The own address consists of the NSAP address only. The NSAP address has to comprise the local ISDN outband address, i.e. the address information used in the D-channel. The own ISDN inband address and subaddress parameters as well as the protocol selectors are meaningless in the Audio/Video Codec Control service. If specified, they will be ignored.
+
+Table I.5-2 shows the address component which has to be specified in the *x\_bind()* call:
+
+**Table I.5-2/T.180 – Address component specified in the *x\_bind()* call**
+
+| ISDN network | Address component | Value                                                                                               |
+|--------------|-------------------|-----------------------------------------------------------------------------------------------------|
+| ISDN/DSS 1   | A_OUTBAND_ADR     | A decimal digit, which is locally mapped to one of the available MSNs (Multiple Subscriber Numbers) |
+
+###### Binding of multiple addresses
+
+In an audiovisual communication according to Recommendations H.221/H.241, multiple channels (up to six B-channels) may be used for one connection. Therefore, multiple addresses have to be bound to a service endpoint if this feature is to be used. The binding of multiple addresses can be achieved by specifying as many A\_OUTBAND\_ADR address components in the *own\_address* buffer of the *x\_bind()* call, as addresses have to be bound. The number of A\_OUTBAND\_ADR components is limited to six for the AV Codec Control service provider.
+
+A passive application has to specify one address for each B-channel to be established. If two B-channels shall be established on the same address, this address has to be mentioned twice in the *own\_address* buffer. Or, the other way around, if an address is specified only once, then only one (ISDN) connection will be accepted for that address.
+
+###### I.5.7.1.3.2 The address of the communication partner
+
+On the active side, the address of the communication partner has to be specified in the *address* buffer of the *call\_struct* passed as argument to the *x\_conreq()* function. On the passive side, the address of the communication partner is returned in the *calling\_addr* buffer of the *x\_conind()* function.
+
+The address of the communication partner comprises at least the peer's ISDN outband address. The peer's ISDN inband address and subaddress as well as the protocol selectors are meaningless for the Audio/Video Codec Control service.
+
+Note that only one called outband address may be specified in the *x\_conreq()*. It is used to establish the initial channel of the AV connection. Additional channels may be added later with the elements of the Mode Switch service. Therefore, only one calling address is returned in the connect indication on the passive side.
+
+Table I.5-3 shows the address component to be used in the *address* buffer specifying the called NSAP address in a *x\_conreq()* call :
+
+**Table I.5-3/T.180 – Address component specifying the called NSAP address in a *x\_conreq()* call**
+
+| ISDN network | Address component | Value                                                                                      |
+|--------------|-------------------|--------------------------------------------------------------------------------------------|
+| ISDN/DSS 1   | A_OUTBAND_ADR     | Optional the country code, optional the area code and the Multiple Subscriber Number (MSN) |
+
+##### I.5.7.1.4 Configuration of the service provider
+
+Protocol options are used to control the general behavior of the service provider. There is a default value defined for each option. These preconfigured values are sufficient for the majority of communication relations. The Option Management service can be used to set protocol options and to retrieve the current or default values of protocol options.
+
+#### I.5.7.2 Connection Establishment service
+
+##### I.5.7.2.1 Service description
+
+During the connection establishment phase, two users of the same service establish a connection between them. The XAPI user must already have prepared a service endpoint before the connection establishment phase can start.
+
+For active establishment of an AV connection, the XAPI function *x\_conreq()* is used. The user can optionally specify local capabilities as service parameters. The local capabilities define the receiver capabilities of the own AV terminal. The service provider generates a positive or negative connect confirmation primitive as a response to the connect request. The positive confirmation signals that an ISDN connection, the Initial Channel (IC), has been established successfully and that both terminals have started to exchange their capabilities on the IC. Later, when the mode initialization procedure is completed on the IC, Additional Channels (ACs) may be added to the connection to increase the total bandwidth. The establishment of additional channels is done with elements of the Mode Switch service. Note that only the AV terminal that initiated the establishment of the IC [the terminal which called *x\_conreq()*], is allowed to establish additional channels.
+
+At the passive side, the service provider generates a connect indication to indicate a pending call of a remote AV terminal. The XAPI user can accept or reject the call by calling the XAPI function *x\_conrsp()*. If the connection is accepted, the capability exchange procedure and the mode initialization procedure according to Recommendation H.242 starts. In the *x\_conrsp()* function call, the local receive capabilities may optionally be specified as service parameters. The default capabilities are used, if none are specified.
+
+For both the active and the passive sides, the **X\_PHC\_SP\_INIT\_COMPL** service primitive indicates the successful completion of the mode initialization procedure. Both terminals have exchanged their receive capabilities and switched their receiver/transmitter to a common mode of communication. If the initialization procedure fails, the AV connection is cleared and the service provider generates a disconnect indication. The XAPI user then has to call *x\_rcvdis()* as consuming function.
+
+The elements of the Connection Establishment service and the corresponding XAPI functions are defined in Table I.5-4.
+
+**Table I.5-4/T.180 – Service elements and their corresponding XAPI functions for Connection Establishment**
+
+| Service element    | XAPI function     | Description                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
+|--------------------|-------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Connect Request    | <i>x_conreq()</i> | The Connect Request is passed to the provider to request the establishment of an AV connection. The own local capabilities to be used in the initial capability exchange may be specified as service parameters. If no capabilities are specified, the default values are used.                                                                                                                                                                                                                                   |
+| Connect Indication | <i>x_conind()</i> | The Connect Indication is generated by the provider to indicate a pending call from a remote terminal. The physical connection is not yet established. A positive connect response will accept the call and start the mode initialization procedure according to Recommendation H.242. The AV connection will be fully operational after successful completion of the initialization procedure. This is indicated with an <b>X_PHC_SP_INIT_COMPL</b> primitive. A negative connect response will reject the call. |
+
+**Table I.5-4/T.180 – Service elements and their corresponding XAPI functions  
+for Connection Establishment (*concluded*)**
+
+| Service element      | XAPI function | Description                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
+|----------------------|---------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Connect Response     | x_conrsp()    | The Connect Response is passed to the provider as reaction to a previously received connect indication. A positive connect response will accept the call and start the mode initialization procedure according to Recommendation H.242. A negative connect response will reject the call. If the call is accepted, the own local capabilities to be used in the initial capability exchange may be specified as service parameters. If no capabilities are specified, the default values are used. |
+| Connect Confirmation | x_conconf()   | The Connect Confirmation is generated by the provider as positive or negative response to a previous connection establishment request. A positive confirmation indicates that the remote terminal accepted the call and the mode initialization procedure is just going on. When it is finished successfully, the AV connection is fully operational. During mode initialization the audio path of the connection may be already available.                                                        |
+
+The element of the mode initialization procedure and the corresponding XAPI function are defined in Table I.5-5.
+
+**Table I.5-5/T.180 – Service elements and their corresponding XAPI function  
+for mode initialization**
+
+| Service element         | XAPI function | Service element identifier | Description                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
+|-------------------------|---------------|----------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Initialization Complete | x_rcvsp()     | X_PHC_SP_INIT_COMPL        | The X_PHC_SP_INIT_COMPL primitive is generated by the service provider to indicate that the mode initialization procedure according to Recommendation H.242 has been finished successfully. The local and remote capabilities and the selected receive and transmit communication mode are presented to the XAPI user as service parameters. Both terminals are operating in the indicated mode. The XAPI user should store the remote capabilities and observe them as limits to avoid failures in later mode switch requests. |
+
+##### **I.5.7.2.2 Service parameters**
+
+The following tables specify the parameters of the Connection Establishment service. There are two groups of parameters: the capability parameters and the communication mode parameters.
+
+The table below shows the local and remote receiving capability parameters. The capabilities are important for the selection of the communication mode used between the two AV terminals. Each side has to select a transmitting mode which is compatible with the receive capabilities of the other terminal. The selected transmitting mode is indicated to the partner with BAS commands and the own transmitter is switched to the selected mode. The other terminal has to switch its receiver according to the mode indicated by the received BAS commands. The local capability parameters share the prefix X\_PHC\_P\_LCAP\_ in their names, and the remote capability parameters share the prefix X\_PHC\_P\_RCAP\_.
+
+The specification of local capabilities is optional. If a capability parameter is not specified in a service element, the default value will be used by the service provider. The default value itself is defined by the value of a protocol option. For each capability parameter there is a corresponding protocol option which defines the default value for this parameter. For the protocol option, a constant default value is defined in the XAPI configuration.
+
+The local receive capabilities are transmitted to the remote terminal during connection establishment. If the value X\_PHC\_PV\_CAPNON is specified for a capability parameter (either explicit or implicit as default), this capability is not transmitted to the remote terminal.
+
+The receive capabilities of the remote terminal will be available after successful completion of the H.242 mode initialization procedure. They are presented to the service user as parameters of the init-complete service element (X\_PHC\_SP\_INIT\_COMPL). For capabilities which were not transmitted by the remote terminal, the value X\_PHC\_PV\_CAPNON is returned.
+
+Table I.5-6 specifies the capability parameters of the Connection Establishment service.
+
+**Table I.5-6/T.180 – Capability Parameters of the Connection Establishment service**
+
+| Parameter            | Connect service |            |          |              |               |
+|----------------------|-----------------|------------|----------|--------------|---------------|
+|                      | Request         | Indication | Response | Confirmation | Init Complete |
+| X_PHC_P_LCAP_AUDIO   | U               |            | U        |              | M             |
+| X_PHC_P_LCAP_VIDEO   | U               |            | U        |              | M             |
+| X_PHC_P_LCAP_DATA    | U               |            | U        |              | M             |
+| X_PHC_P_LCAP_HDATA   | U               |            | U        |              | M             |
+| X_PHC_P_LCAP_TFRATE  | U               |            | U        |              | M             |
+| X_PHC_P_LCAP_TFLINES | U               |            | U        |              | M             |
+| X_PHC_P_LCAP_MISC    | U               |            | U        |              | M             |
+| X_PHC_P_LCAP_DATAPPL | U               |            | U        |              | M             |
+| X_PHC_P_LCAP_NONSTD  | U               |            | U        |              | C             |
+| X_PHC_P_FALLBACK     | U               |            |          |              |               |
+| X_PHC_P_RCAP_AUDIO   |                 |            |          |              | M             |
+| X_PHC_P_RCAP_VIDEO   |                 |            |          |              | M             |
+| X_PHC_P_RCAP_DATA    |                 |            |          |              | M             |
+| X_PHC_P_RCAP_HDATA   |                 |            |          |              | M             |
+| X_PHC_P_RCAP_TFRATE  |                 |            |          |              | M             |
+| X_PHC_P_RCAP_TFLINES |                 |            |          |              | M             |
+| X_PHC_P_RCAP_MISC    |                 |            |          |              | M             |
+| X_PHC_P_RCAP_DATAPPL |                 |            |          |              | M             |
+| X_PHC_P_RCAP_NONSTD  |                 |            |          |              | C             |
+
+Table I.5-7 specifies the communication mode parameters. They are always returned by the init-complete primitive and indicate the receive and transmit mode that is currently used in the audiovisual communication on the actually established connection. The receive mode parameters share the prefix X\_PHC\_P\_RMOD\_ in their names and the transmit mode parameters share the prefix X\_PHC\_P\_TMOD\_.
+
+**Table I.5-7/T.180 – Communication mode parameters of the Connection Establishment service**
+
+| Parameter            | Connect service |            |          |              |               |
+|----------------------|-----------------|------------|----------|--------------|---------------|
+|                      | Request         | Indication | Response | Confirmation | Init-complete |
+| X_PHC_P_RMOD_AUDIO   |                 |            |          |              | M             |
+| X_PHC_P_RMOD_VIDEO   |                 |            |          |              | M             |
+| X_PHC_P_RMOD_DATA    |                 |            |          |              | M             |
+| X_PHC_P_RMOD_HDATA   |                 |            |          |              | M             |
+| X_PHC_P_RMOD_TFRATE  |                 |            |          |              | M             |
+| X_PHC_P_RMOD_SYNC    |                 |            |          |              | M             |
+| X_PHC_P_RMOD_DATAPPL |                 |            |          |              | M             |
+| X_PHC_P_RMOD_MISC    |                 |            |          |              | M             |
+| X_PHC_P_TMOD_AUDIO   |                 |            |          |              | M             |
+| X_PHC_P_TMOD_VIDEO   |                 |            |          |              | M             |
+| X_PHC_P_TMOD_DATA    |                 |            |          |              | M             |
+| X_PHC_P_TMOD_HDATA   |                 |            |          |              | M             |
+| X_PHC_P_TMOD_TFRATE  |                 |            |          |              | M             |
+| X_PHC_P_TMOD_SYNC    |                 |            |          |              | M             |
+| X_PHC_P_TMOD_DATAPPL |                 |            |          |              | M             |
+| X_PHC_P_TMOD_MISC    |                 |            |          |              | M             |
+| X_PHC_P_MODE_TFLINES |                 |            |          |              | M             |
+
+##### **I.5.7.2.3 Service parameter descriptions**
+
+Tables I.5-8 to I.5-26 define the capability parameters for the elements of the Connection Establishment service. The definitions of the communication mode parameters can be found below in I.5.7.3.2, "Mode Switch service".
+
+###### I.5.7.2.3.1 Local capability parameters
+
+**Table I.5-8/T.180**
+
+|                       |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                 |                              |                      |                              |                      |                                   |                       |                                          |                       |                                                 |                    |                                 |                    |                                                            |
+|-----------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------|------------------------------|----------------------|------------------------------|----------------------|-----------------------------------|-----------------------|------------------------------------------|-----------------------|-------------------------------------------------|--------------------|---------------------------------|--------------------|------------------------------------------------------------|
+| Parameter name        | X_PHC_P_LCAP_AUDIO                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |                 |                              |                      |                              |                      |                                   |                       |                                          |                       |                                                 |                    |                                 |                    |                                                            |
+| Type of value         | long                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |                 |                              |                      |                              |                      |                                   |                       |                                          |                       |                                                 |                    |                                 |                    |                                                            |
+| Legal values          | X_PHC_PV_CAPNON<br>X_PHC_PV_AUDIO_711_A<br>X_PHC_PV_AUDIO_711_U<br>X_PHC_PV_AUDIO_722_64<br>X_PHC_PV_AUDIO_722_48<br>X_PHC_PV_AUDIO_16K<br>X_PHC_PV_AUDIO_ISO                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |                 |                              |                      |                              |                      |                                   |                       |                                          |                       |                                                 |                    |                                 |                    |                                                            |
+| Default value         | The default value is defined by the value of the X_PHC_O_LCAP_AUDIO option.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |                 |                              |                      |                              |                      |                                   |                       |                                          |                       |                                                 |                    |                                 |                    |                                                            |
+| Description           | <p>The parameter specifies the audio reception capabilities of the local receiver. The parameter values correspond to the audio capabilities defined in the BAS table of Recommendation H.221:</p> <table> <tr> <td>X_PHC_PV_CAPNON</td> <td>No audio capability defined;</td> </tr> <tr> <td>X_PHC_PV_AUDIO_711_A</td> <td>Audio decoding G.711, A-law;</td> </tr> <tr> <td>X_PHC_PV_AUDIO_711_U</td> <td>Audio decoding G.711, <math>\mu</math>-law;</td> </tr> <tr> <td>X_PHC_PV_AUDIO_722_64</td> <td>Audio decoding G.722 (mode 1) and G.711;</td> </tr> <tr> <td>X_PHC_PV_AUDIO_722_48</td> <td>Audio decoding G.722 (modes 1, 2, 3) and G.711;</td> </tr> <tr> <td>X_PHC_PV_AUDIO_16K</td> <td>Audio decoding G.728 and G.711;</td> </tr> <tr> <td>X_PHC_PV_AUDIO_ISO</td> <td>Audio decoding ISO standard at all rates up to 384 kbit/s;</td> </tr> </table> <p>It is possible to select more than one of the audio capabilities listed above. In this case the parameter values have to be combined using a bit-wise OR. Each parameter value sets one bit position of the X_PHC_P_LCAP_AUDIO parameter.</p> | X_PHC_PV_CAPNON | No audio capability defined; | X_PHC_PV_AUDIO_711_A | Audio decoding G.711, A-law; | X_PHC_PV_AUDIO_711_U | Audio decoding G.711, $\mu$ -law; | X_PHC_PV_AUDIO_722_64 | Audio decoding G.722 (mode 1) and G.711; | X_PHC_PV_AUDIO_722_48 | Audio decoding G.722 (modes 1, 2, 3) and G.711; | X_PHC_PV_AUDIO_16K | Audio decoding G.728 and G.711; | X_PHC_PV_AUDIO_ISO | Audio decoding ISO standard at all rates up to 384 kbit/s; |
+| X_PHC_PV_CAPNON       | No audio capability defined;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |                 |                              |                      |                              |                      |                                   |                       |                                          |                       |                                                 |                    |                                 |                    |                                                            |
+| X_PHC_PV_AUDIO_711_A  | Audio decoding G.711, A-law;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |                 |                              |                      |                              |                      |                                   |                       |                                          |                       |                                                 |                    |                                 |                    |                                                            |
+| X_PHC_PV_AUDIO_711_U  | Audio decoding G.711, $\mu$ -law;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |                 |                              |                      |                              |                      |                                   |                       |                                          |                       |                                                 |                    |                                 |                    |                                                            |
+| X_PHC_PV_AUDIO_722_64 | Audio decoding G.722 (mode 1) and G.711;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |                 |                              |                      |                              |                      |                                   |                       |                                          |                       |                                                 |                    |                                 |                    |                                                            |
+| X_PHC_PV_AUDIO_722_48 | Audio decoding G.722 (modes 1, 2, 3) and G.711;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                 |                              |                      |                              |                      |                                   |                       |                                          |                       |                                                 |                    |                                 |                    |                                                            |
+| X_PHC_PV_AUDIO_16K    | Audio decoding G.728 and G.711;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                 |                              |                      |                              |                      |                                   |                       |                                          |                       |                                                 |                    |                                 |                    |                                                            |
+| X_PHC_PV_AUDIO_ISO    | Audio decoding ISO standard at all rates up to 384 kbit/s;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |                 |                              |                      |                              |                      |                                   |                       |                                          |                       |                                                 |                    |                                 |                    |                                                            |
+
+**Table I.5-9/T.180**
+
+|                      |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |                 |                              |                     |                              |                    |                                 |                      |                                      |                      |                                      |                      |                                      |                      |                                      |                    |                                                  |                    |                                 |                      |                                                              |
+|----------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------|------------------------------|---------------------|------------------------------|--------------------|---------------------------------|----------------------|--------------------------------------|----------------------|--------------------------------------|----------------------|--------------------------------------|----------------------|--------------------------------------|--------------------|--------------------------------------------------|--------------------|---------------------------------|----------------------|--------------------------------------------------------------|
+| Parameter name       | X_PHC_P_LCAP_VIDEO                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                 |                              |                     |                              |                    |                                 |                      |                                      |                      |                                      |                      |                                      |                      |                                      |                    |                                                  |                    |                                 |                      |                                                              |
+| Type of value        | long                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |                 |                              |                     |                              |                    |                                 |                      |                                      |                      |                                      |                      |                                      |                      |                                      |                    |                                                  |                    |                                 |                      |                                                              |
+| Legal values         | X_PHC_PV_CAPNON<br>X_PHC_PV_VIDEO_QCIF<br>X_PHC_PV_VIDEO_CIF<br>X_PHC_PV_VIDEO_PINV1<br>X_PHC_PV_VIDEO_PINV2<br>X_PHC_PV_VIDEO_PINV3<br>X_PHC_PV_VIDEO_PINV4<br>X_PHC_PV_VIDEO_IMP<br>X_PHC_PV_VIDEO_ISO<br>X_PHC_PV_VIDEO_AVISO                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |                 |                              |                     |                              |                    |                                 |                      |                                      |                      |                                      |                      |                                      |                      |                                      |                    |                                                  |                    |                                 |                      |                                                              |
+| Default value        | The default value is defined by the value of the X_PHC_O_LCAP_VIDEO option.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |                 |                              |                     |                              |                    |                                 |                      |                                      |                      |                                      |                      |                                      |                      |                                      |                    |                                                  |                    |                                 |                      |                                                              |
+| Description          | <p>The parameter specifies the video reception capabilities of the local receiver. The parameter values correspond to the video capabilities defined in the BAS table of Recommendation H.221:</p> <table> <tr> <td>X_PHC_PV_CAPNON</td> <td>No video capability defined;</td> </tr> <tr> <td>X_PHC_PV_VIDEO_QCIF</td> <td>Video decoding of QCIF only;</td> </tr> <tr> <td>X_PHC_PV_VIDEO_CIF</td> <td>Video decoding of CIF and QCIF;</td> </tr> <tr> <td>X_PHC_PV_VIDEO_PINV1</td> <td>Minimum picture interval of 1/29.97;</td> </tr> <tr> <td>X_PHC_PV_VIDEO_PINV2</td> <td>Minimum picture interval of 2/29.97;</td> </tr> <tr> <td>X_PHC_PV_VIDEO_PINV3</td> <td>Minimum picture interval of 3/29.97;</td> </tr> <tr> <td>X_PHC_PV_VIDEO_PINV4</td> <td>Minimum picture interval of 4/29.97;</td> </tr> <tr> <td>X_PHC_PV_VIDEO_IMP</td> <td>Improved video algorithm (for future use only!);</td> </tr> <tr> <td>X_PHC_PV_VIDEO_ISO</td> <td>Video decoding to ISO standard.</td> </tr> <tr> <td>X_PHC_PV_VIDEO_AVISO</td> <td>Video decoding composite audio/video signal to ISO standard.</td> </tr> </table> <p>It is possible to select more than one of the video capabilities listed above. In this case the parameter values have to be combined using a bit-wise OR. Each parameter value sets one bit position of the X_PHC_P_LCAP_VIDEO parameter.</p> | X_PHC_PV_CAPNON | No video capability defined; | X_PHC_PV_VIDEO_QCIF | Video decoding of QCIF only; | X_PHC_PV_VIDEO_CIF | Video decoding of CIF and QCIF; | X_PHC_PV_VIDEO_PINV1 | Minimum picture interval of 1/29.97; | X_PHC_PV_VIDEO_PINV2 | Minimum picture interval of 2/29.97; | X_PHC_PV_VIDEO_PINV3 | Minimum picture interval of 3/29.97; | X_PHC_PV_VIDEO_PINV4 | Minimum picture interval of 4/29.97; | X_PHC_PV_VIDEO_IMP | Improved video algorithm (for future use only!); | X_PHC_PV_VIDEO_ISO | Video decoding to ISO standard. | X_PHC_PV_VIDEO_AVISO | Video decoding composite audio/video signal to ISO standard. |
+| X_PHC_PV_CAPNON      | No video capability defined;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |                 |                              |                     |                              |                    |                                 |                      |                                      |                      |                                      |                      |                                      |                      |                                      |                    |                                                  |                    |                                 |                      |                                                              |
+| X_PHC_PV_VIDEO_QCIF  | Video decoding of QCIF only;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |                 |                              |                     |                              |                    |                                 |                      |                                      |                      |                                      |                      |                                      |                      |                                      |                    |                                                  |                    |                                 |                      |                                                              |
+| X_PHC_PV_VIDEO_CIF   | Video decoding of CIF and QCIF;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |                 |                              |                     |                              |                    |                                 |                      |                                      |                      |                                      |                      |                                      |                      |                                      |                    |                                                  |                    |                                 |                      |                                                              |
+| X_PHC_PV_VIDEO_PINV1 | Minimum picture interval of 1/29.97;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |                 |                              |                     |                              |                    |                                 |                      |                                      |                      |                                      |                      |                                      |                      |                                      |                    |                                                  |                    |                                 |                      |                                                              |
+| X_PHC_PV_VIDEO_PINV2 | Minimum picture interval of 2/29.97;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |                 |                              |                     |                              |                    |                                 |                      |                                      |                      |                                      |                      |                                      |                      |                                      |                    |                                                  |                    |                                 |                      |                                                              |
+| X_PHC_PV_VIDEO_PINV3 | Minimum picture interval of 3/29.97;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |                 |                              |                     |                              |                    |                                 |                      |                                      |                      |                                      |                      |                                      |                      |                                      |                    |                                                  |                    |                                 |                      |                                                              |
+| X_PHC_PV_VIDEO_PINV4 | Minimum picture interval of 4/29.97;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |                 |                              |                     |                              |                    |                                 |                      |                                      |                      |                                      |                      |                                      |                      |                                      |                    |                                                  |                    |                                 |                      |                                                              |
+| X_PHC_PV_VIDEO_IMP   | Improved video algorithm (for future use only!);                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |                 |                              |                     |                              |                    |                                 |                      |                                      |                      |                                      |                      |                                      |                      |                                      |                    |                                                  |                    |                                 |                      |                                                              |
+| X_PHC_PV_VIDEO_ISO   | Video decoding to ISO standard.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |                 |                              |                     |                              |                    |                                 |                      |                                      |                      |                                      |                      |                                      |                      |                                      |                    |                                                  |                    |                                 |                      |                                                              |
+| X_PHC_PV_VIDEO_AVISO | Video decoding composite audio/video signal to ISO standard.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |                 |                              |                     |                              |                    |                                 |                      |                                      |                      |                                      |                      |                                      |                      |                                      |                    |                                                  |                    |                                 |                      |                                                              |
+
+**Table I.5-10/T.180**
+
+|                       |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |                 |                            |                   |                                  |                   |                              |                    |                               |                    |                               |                    |                               |                    |                               |                    |                               |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                       |                                       |                       |                                         |                      |                                              |
+|-----------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------|----------------------------|-------------------|----------------------------------|-------------------|------------------------------|--------------------|-------------------------------|--------------------|-------------------------------|--------------------|-------------------------------|--------------------|-------------------------------|--------------------|-------------------------------|---------------------|---------------------------------|---------------------|---------------------------------|---------------------|---------------------------------|---------------------|---------------------------------|---------------------|---------------------------------|---------------------|---------------------------------|---------------------|---------------------------------|---------------------|---------------------------------|---------------------|---------------------------------|-----------------------|---------------------------------------|-----------------------|-----------------------------------------|----------------------|----------------------------------------------|
+| Parameter name        | X_PHC_P_LCAP_DATA                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |                 |                            |                   |                                  |                   |                              |                    |                               |                    |                               |                    |                               |                    |                               |                    |                               |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                       |                                       |                       |                                         |                      |                                              |
+| Type of value         | long                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |                 |                            |                   |                                  |                   |                              |                    |                               |                    |                               |                    |                               |                    |                               |                    |                               |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                       |                                       |                       |                                         |                      |                                              |
+| Legal values          | X_PHC_PV_CAPNON<br>X_PHC_PV_DATA_VAR<br>X_PHC_PV_DATA_300                      X_PHC_PV_DATA_1200<br>X_PHC_PV_DATA_4800                    X_PHC_PV_DATA_6400<br>X_PHC_PV_DATA_8000                    X_PHC_PV_DATA_9600<br>X_PHC_PV_DATA_14400                   X_PHC_PV_DATA_16000<br>X_PHC_PV_DATA_24000                   X_PHC_PV_DATA_32000<br>X_PHC_PV_DATA_40000                   X_PHC_PV_DATA_48000<br>X_PHC_PV_DATA_56000                   X_PHC_PV_DATA_62400<br>X_PHC_PV_DATA_64000<br><br>X_PHC_PV_DATA_MLP4000    X_PHC_PV_DATA_MLP6400<br>X_PHC_PV_DATA_VARMLP                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |                 |                            |                   |                                  |                   |                              |                    |                               |                    |                               |                    |                               |                    |                               |                    |                               |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                       |                                       |                       |                                         |                      |                                              |
+| Default value         | The default value is defined by the value of the X_PHC_O_LCAP_DATA option.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |                 |                            |                   |                                  |                   |                              |                    |                               |                    |                               |                    |                               |                    |                               |                    |                               |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                       |                                       |                       |                                         |                      |                                              |
+| Description           | <p>The parameter specifies the Low-Speed Data (LSD) reception capabilities of the local receiver. The parameter values correspond to the LSD capabilities defined in the BAS table of Recommendation H.221:</p> <table style="border: none;"> <tr><td>X_PHC_PV_CAPNON</td><td>No LSD capability defined;</td></tr> <tr><td>X_PHC_PV_DATA_VAR</td><td>Can accept variable rate of LSD;</td></tr> <tr><td>X_PHC_PV_DATA_300</td><td>Can accept LSD at 300 bit/s;</td></tr> <tr><td>X_PHC_PV_DATA_1200</td><td>Can accept LSD at 1200 bit/s;</td></tr> <tr><td>X_PHC_PV_DATA_4800</td><td>Can accept LSD at 4800 bit/s;</td></tr> <tr><td>X_PHC_PV_DATA_6400</td><td>Can accept LSD at 6400 bit/s;</td></tr> <tr><td>X_PHC_PV_DATA_8000</td><td>Can accept LSD at 8000 bit/s;</td></tr> <tr><td>X_PHC_PV_DATA_9600</td><td>Can accept LSD at 9600 bit/s;</td></tr> <tr><td>X_PHC_PV_DATA_14400</td><td>Can accept LSD at 14 400 bit/s;</td></tr> <tr><td>X_PHC_PV_DATA_16000</td><td>Can accept LSD at 16 000 bit/s;</td></tr> <tr><td>X_PHC_PV_DATA_24000</td><td>Can accept LSD at 24 000 bit/s;</td></tr> <tr><td>X_PHC_PV_DATA_32000</td><td>Can accept LSD at 32 000 bit/s;</td></tr> <tr><td>X_PHC_PV_DATA_40000</td><td>Can accept LSD at 40 000 bit/s;</td></tr> <tr><td>X_PHC_PV_DATA_48000</td><td>Can accept LSD at 48 000 bit/s;</td></tr> <tr><td>X_PHC_PV_DATA_56000</td><td>Can accept LSD at 56 000 bit/s;</td></tr> <tr><td>X_PHC_PV_DATA_62400</td><td>Can accept LSD at 62 400 bit/s;</td></tr> <tr><td>X_PHC_PV_DATA_64000</td><td>Can accept LSD at 64 000 bit/s;</td></tr> <tr><td>X_PHC_PV_DATA_MLP4000</td><td>Can accept MLP at 4 kbit/s in the SC;</td></tr> <tr><td>X_PHC_PV_DATA_MLP6400</td><td>Can accept MLP at 6.4 kbit/s in the SC;</td></tr> <tr><td>X_PHC_PV_DATA_VARMLP</td><td>Can accept MLP at up to 64 kbit/s in the IC.</td></tr> </table> <p>It is possible to select more than one of the low-speed data capabilities listed above. In this case the parameter values have to be combined using a bit-wise OR. Each parameter value sets one bit position of the X_PHC_P_LCAP_DATA parameter.</p> | X_PHC_PV_CAPNON | No LSD capability defined; | X_PHC_PV_DATA_VAR | Can accept variable rate of LSD; | X_PHC_PV_DATA_300 | Can accept LSD at 300 bit/s; | X_PHC_PV_DATA_1200 | Can accept LSD at 1200 bit/s; | X_PHC_PV_DATA_4800 | Can accept LSD at 4800 bit/s; | X_PHC_PV_DATA_6400 | Can accept LSD at 6400 bit/s; | X_PHC_PV_DATA_8000 | Can accept LSD at 8000 bit/s; | X_PHC_PV_DATA_9600 | Can accept LSD at 9600 bit/s; | X_PHC_PV_DATA_14400 | Can accept LSD at 14 400 bit/s; | X_PHC_PV_DATA_16000 | Can accept LSD at 16 000 bit/s; | X_PHC_PV_DATA_24000 | Can accept LSD at 24 000 bit/s; | X_PHC_PV_DATA_32000 | Can accept LSD at 32 000 bit/s; | X_PHC_PV_DATA_40000 | Can accept LSD at 40 000 bit/s; | X_PHC_PV_DATA_48000 | Can accept LSD at 48 000 bit/s; | X_PHC_PV_DATA_56000 | Can accept LSD at 56 000 bit/s; | X_PHC_PV_DATA_62400 | Can accept LSD at 62 400 bit/s; | X_PHC_PV_DATA_64000 | Can accept LSD at 64 000 bit/s; | X_PHC_PV_DATA_MLP4000 | Can accept MLP at 4 kbit/s in the SC; | X_PHC_PV_DATA_MLP6400 | Can accept MLP at 6.4 kbit/s in the SC; | X_PHC_PV_DATA_VARMLP | Can accept MLP at up to 64 kbit/s in the IC. |
+| X_PHC_PV_CAPNON       | No LSD capability defined;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |                 |                            |                   |                                  |                   |                              |                    |                               |                    |                               |                    |                               |                    |                               |                    |                               |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                       |                                       |                       |                                         |                      |                                              |
+| X_PHC_PV_DATA_VAR     | Can accept variable rate of LSD;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |                 |                            |                   |                                  |                   |                              |                    |                               |                    |                               |                    |                               |                    |                               |                    |                               |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                       |                                       |                       |                                         |                      |                                              |
+| X_PHC_PV_DATA_300     | Can accept LSD at 300 bit/s;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |                 |                            |                   |                                  |                   |                              |                    |                               |                    |                               |                    |                               |                    |                               |                    |                               |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                       |                                       |                       |                                         |                      |                                              |
+| X_PHC_PV_DATA_1200    | Can accept LSD at 1200 bit/s;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |                 |                            |                   |                                  |                   |                              |                    |                               |                    |                               |                    |                               |                    |                               |                    |                               |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                       |                                       |                       |                                         |                      |                                              |
+| X_PHC_PV_DATA_4800    | Can accept LSD at 4800 bit/s;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |                 |                            |                   |                                  |                   |                              |                    |                               |                    |                               |                    |                               |                    |                               |                    |                               |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                       |                                       |                       |                                         |                      |                                              |
+| X_PHC_PV_DATA_6400    | Can accept LSD at 6400 bit/s;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |                 |                            |                   |                                  |                   |                              |                    |                               |                    |                               |                    |                               |                    |                               |                    |                               |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                       |                                       |                       |                                         |                      |                                              |
+| X_PHC_PV_DATA_8000    | Can accept LSD at 8000 bit/s;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |                 |                            |                   |                                  |                   |                              |                    |                               |                    |                               |                    |                               |                    |                               |                    |                               |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                       |                                       |                       |                                         |                      |                                              |
+| X_PHC_PV_DATA_9600    | Can accept LSD at 9600 bit/s;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |                 |                            |                   |                                  |                   |                              |                    |                               |                    |                               |                    |                               |                    |                               |                    |                               |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                       |                                       |                       |                                         |                      |                                              |
+| X_PHC_PV_DATA_14400   | Can accept LSD at 14 400 bit/s;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |                 |                            |                   |                                  |                   |                              |                    |                               |                    |                               |                    |                               |                    |                               |                    |                               |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                       |                                       |                       |                                         |                      |                                              |
+| X_PHC_PV_DATA_16000   | Can accept LSD at 16 000 bit/s;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |                 |                            |                   |                                  |                   |                              |                    |                               |                    |                               |                    |                               |                    |                               |                    |                               |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                       |                                       |                       |                                         |                      |                                              |
+| X_PHC_PV_DATA_24000   | Can accept LSD at 24 000 bit/s;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |                 |                            |                   |                                  |                   |                              |                    |                               |                    |                               |                    |                               |                    |                               |                    |                               |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                       |                                       |                       |                                         |                      |                                              |
+| X_PHC_PV_DATA_32000   | Can accept LSD at 32 000 bit/s;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |                 |                            |                   |                                  |                   |                              |                    |                               |                    |                               |                    |                               |                    |                               |                    |                               |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                       |                                       |                       |                                         |                      |                                              |
+| X_PHC_PV_DATA_40000   | Can accept LSD at 40 000 bit/s;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |                 |                            |                   |                                  |                   |                              |                    |                               |                    |                               |                    |                               |                    |                               |                    |                               |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                       |                                       |                       |                                         |                      |                                              |
+| X_PHC_PV_DATA_48000   | Can accept LSD at 48 000 bit/s;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |                 |                            |                   |                                  |                   |                              |                    |                               |                    |                               |                    |                               |                    |                               |                    |                               |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                       |                                       |                       |                                         |                      |                                              |
+| X_PHC_PV_DATA_56000   | Can accept LSD at 56 000 bit/s;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |                 |                            |                   |                                  |                   |                              |                    |                               |                    |                               |                    |                               |                    |                               |                    |                               |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                       |                                       |                       |                                         |                      |                                              |
+| X_PHC_PV_DATA_62400   | Can accept LSD at 62 400 bit/s;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |                 |                            |                   |                                  |                   |                              |                    |                               |                    |                               |                    |                               |                    |                               |                    |                               |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                       |                                       |                       |                                         |                      |                                              |
+| X_PHC_PV_DATA_64000   | Can accept LSD at 64 000 bit/s;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |                 |                            |                   |                                  |                   |                              |                    |                               |                    |                               |                    |                               |                    |                               |                    |                               |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                       |                                       |                       |                                         |                      |                                              |
+| X_PHC_PV_DATA_MLP4000 | Can accept MLP at 4 kbit/s in the SC;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |                 |                            |                   |                                  |                   |                              |                    |                               |                    |                               |                    |                               |                    |                               |                    |                               |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                       |                                       |                       |                                         |                      |                                              |
+| X_PHC_PV_DATA_MLP6400 | Can accept MLP at 6.4 kbit/s in the SC;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |                 |                            |                   |                                  |                   |                              |                    |                               |                    |                               |                    |                               |                    |                               |                    |                               |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                       |                                       |                       |                                         |                      |                                              |
+| X_PHC_PV_DATA_VARMLP  | Can accept MLP at up to 64 kbit/s in the IC.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |                 |                            |                   |                                  |                   |                              |                    |                               |                    |                               |                    |                               |                    |                               |                    |                               |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                     |                                 |                       |                                       |                       |                                         |                      |                                              |
+
+**Table I.5-11/T.180**
+
+|                          |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |                   |                            |                    |                              |                    |                               |                    |                               |                     |                               |                    |                               |                          |                               |                       |                                                     |                       |                                                     |                       |                                                      |                       |                                                      |                    |                                  |                      |                                |                      |                              |                       |                               |                       |                               |                       |                               |                       |                               |                       |                               |                       |                                  |
+|--------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------|----------------------------|--------------------|------------------------------|--------------------|-------------------------------|--------------------|-------------------------------|---------------------|-------------------------------|--------------------|-------------------------------|--------------------------|-------------------------------|-----------------------|-----------------------------------------------------|-----------------------|-----------------------------------------------------|-----------------------|------------------------------------------------------|-----------------------|------------------------------------------------------|--------------------|----------------------------------|----------------------|--------------------------------|----------------------|------------------------------|-----------------------|-------------------------------|-----------------------|-------------------------------|-----------------------|-------------------------------|-----------------------|-------------------------------|-----------------------|-------------------------------|-----------------------|----------------------------------|
+| Parameter name           | X_PHC_P_LCAP_HDATA                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |                   |                            |                    |                              |                    |                               |                    |                               |                     |                               |                    |                               |                          |                               |                       |                                                     |                       |                                                     |                       |                                                      |                       |                                                      |                    |                                  |                      |                                |                      |                              |                       |                               |                       |                               |                       |                               |                       |                               |                       |                               |                       |                                  |
+| Type of value            | long                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |                   |                            |                    |                              |                    |                               |                    |                               |                     |                               |                    |                               |                          |                               |                       |                                                     |                       |                                                     |                       |                                                      |                       |                                                      |                    |                                  |                      |                                |                      |                              |                       |                               |                       |                               |                       |                               |                       |                               |                       |                               |                       |                                  |
+| Legal values             | <p>X_PHC_PV_CAPNON</p> <table style="width:100%"> <tr> <td>X_PHC_PV_HDATA_64</td> <td>X_PHC_PV_HDATA_128</td> </tr> <tr> <td>X_PHC_PV_HDATA_192</td> <td>X_PHC_PV_HDATA_256</td> </tr> <tr> <td>X_PHC_PV_HDATA_320</td> <td>X_PHC_PV_HDATA_384</td> </tr> <tr> <td>X_PHC_PV_HDATA_512</td> <td>X_PHC_PV_HDATA_768</td> </tr> <tr> <td>X_PHC_PV_HDATA_1152</td> <td>X_PHC_PV_HDATA_1536</td> </tr> <tr> <td>X_PHC_PV_HDATA_VAR</td> <td></td> </tr> <tr> <td><br/>X_PHC_PV_HDATA_MLP62</td> <td><br/>X_PHC_PV_HDATA_MLP64</td> </tr> <tr> <td>X_PHC_PV_HDATA_MLP128</td> <td>X_PHC_PV_HDATA_MLP192</td> </tr> <tr> <td>X_PHC_PV_HDATA_MLP256</td> <td>X_PHC_PV_HDATA_MLP320</td> </tr> <tr> <td>X_PHC_PV_HDATA_MLP384</td> <td></td> </tr> <tr> <td>X_PHC_PV_HDATA_VARMLP</td> <td></td> </tr> </table>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            | X_PHC_PV_HDATA_64 | X_PHC_PV_HDATA_128         | X_PHC_PV_HDATA_192 | X_PHC_PV_HDATA_256           | X_PHC_PV_HDATA_320 | X_PHC_PV_HDATA_384            | X_PHC_PV_HDATA_512 | X_PHC_PV_HDATA_768            | X_PHC_PV_HDATA_1152 | X_PHC_PV_HDATA_1536           | X_PHC_PV_HDATA_VAR |                               | <br>X_PHC_PV_HDATA_MLP62 | <br>X_PHC_PV_HDATA_MLP64      | X_PHC_PV_HDATA_MLP128 | X_PHC_PV_HDATA_MLP192                               | X_PHC_PV_HDATA_MLP256 | X_PHC_PV_HDATA_MLP320                               | X_PHC_PV_HDATA_MLP384 |                                                      | X_PHC_PV_HDATA_VARMLP |                                                      |                    |                                  |                      |                                |                      |                              |                       |                               |                       |                               |                       |                               |                       |                               |                       |                               |                       |                                  |
+| X_PHC_PV_HDATA_64        | X_PHC_PV_HDATA_128                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |                   |                            |                    |                              |                    |                               |                    |                               |                     |                               |                    |                               |                          |                               |                       |                                                     |                       |                                                     |                       |                                                      |                       |                                                      |                    |                                  |                      |                                |                      |                              |                       |                               |                       |                               |                       |                               |                       |                               |                       |                               |                       |                                  |
+| X_PHC_PV_HDATA_192       | X_PHC_PV_HDATA_256                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |                   |                            |                    |                              |                    |                               |                    |                               |                     |                               |                    |                               |                          |                               |                       |                                                     |                       |                                                     |                       |                                                      |                       |                                                      |                    |                                  |                      |                                |                      |                              |                       |                               |                       |                               |                       |                               |                       |                               |                       |                               |                       |                                  |
+| X_PHC_PV_HDATA_320       | X_PHC_PV_HDATA_384                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |                   |                            |                    |                              |                    |                               |                    |                               |                     |                               |                    |                               |                          |                               |                       |                                                     |                       |                                                     |                       |                                                      |                       |                                                      |                    |                                  |                      |                                |                      |                              |                       |                               |                       |                               |                       |                               |                       |                               |                       |                               |                       |                                  |
+| X_PHC_PV_HDATA_512       | X_PHC_PV_HDATA_768                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |                   |                            |                    |                              |                    |                               |                    |                               |                     |                               |                    |                               |                          |                               |                       |                                                     |                       |                                                     |                       |                                                      |                       |                                                      |                    |                                  |                      |                                |                      |                              |                       |                               |                       |                               |                       |                               |                       |                               |                       |                               |                       |                                  |
+| X_PHC_PV_HDATA_1152      | X_PHC_PV_HDATA_1536                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |                   |                            |                    |                              |                    |                               |                    |                               |                     |                               |                    |                               |                          |                               |                       |                                                     |                       |                                                     |                       |                                                      |                       |                                                      |                    |                                  |                      |                                |                      |                              |                       |                               |                       |                               |                       |                               |                       |                               |                       |                               |                       |                                  |
+| X_PHC_PV_HDATA_VAR       |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |                   |                            |                    |                              |                    |                               |                    |                               |                     |                               |                    |                               |                          |                               |                       |                                                     |                       |                                                     |                       |                                                      |                       |                                                      |                    |                                  |                      |                                |                      |                              |                       |                               |                       |                               |                       |                               |                       |                               |                       |                               |                       |                                  |
+| <br>X_PHC_PV_HDATA_MLP62 | <br>X_PHC_PV_HDATA_MLP64                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |                   |                            |                    |                              |                    |                               |                    |                               |                     |                               |                    |                               |                          |                               |                       |                                                     |                       |                                                     |                       |                                                      |                       |                                                      |                    |                                  |                      |                                |                      |                              |                       |                               |                       |                               |                       |                               |                       |                               |                       |                               |                       |                                  |
+| X_PHC_PV_HDATA_MLP128    | X_PHC_PV_HDATA_MLP192                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |                   |                            |                    |                              |                    |                               |                    |                               |                     |                               |                    |                               |                          |                               |                       |                                                     |                       |                                                     |                       |                                                      |                       |                                                      |                    |                                  |                      |                                |                      |                              |                       |                               |                       |                               |                       |                               |                       |                               |                       |                               |                       |                                  |
+| X_PHC_PV_HDATA_MLP256    | X_PHC_PV_HDATA_MLP320                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |                   |                            |                    |                              |                    |                               |                    |                               |                     |                               |                    |                               |                          |                               |                       |                                                     |                       |                                                     |                       |                                                      |                       |                                                      |                    |                                  |                      |                                |                      |                              |                       |                               |                       |                               |                       |                               |                       |                               |                       |                               |                       |                                  |
+| X_PHC_PV_HDATA_MLP384    |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |                   |                            |                    |                              |                    |                               |                    |                               |                     |                               |                    |                               |                          |                               |                       |                                                     |                       |                                                     |                       |                                                      |                       |                                                      |                    |                                  |                      |                                |                      |                              |                       |                               |                       |                               |                       |                               |                       |                               |                       |                               |                       |                                  |
+| X_PHC_PV_HDATA_VARMLP    |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |                   |                            |                    |                              |                    |                               |                    |                               |                     |                               |                    |                               |                          |                               |                       |                                                     |                       |                                                     |                       |                                                      |                       |                                                      |                    |                                  |                      |                                |                      |                              |                       |                               |                       |                               |                       |                               |                       |                               |                       |                               |                       |                                  |
+| Default value            | The default value is defined by the value of the X_PHC_O_LCAP_HDATA option.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                   |                            |                    |                              |                    |                               |                    |                               |                     |                               |                    |                               |                          |                               |                       |                                                     |                       |                                                     |                       |                                                      |                       |                                                      |                    |                                  |                      |                                |                      |                              |                       |                               |                       |                               |                       |                               |                       |                               |                       |                               |                       |                                  |
+| Description              | <p>The parameter specifies the high-speed data reception capabilities of the local receiver. The parameter values correspond to the HSD capabilities defined in the BAS table of Recommendation H.221:</p> <table style="width:100%"> <tr> <td>X_PHC_PV_CAPNON</td> <td>No HSD capability defined;</td> </tr> <tr> <td>X_PHC_PV_HDATA_64</td> <td>Can accept HSD at 64 kbit/s;</td> </tr> <tr> <td>X_PHC_PV_HDATA_128</td> <td>Can accept HSD at 128 kbit/s;</td> </tr> <tr> <td>X_PHC_PV_HDATA_192</td> <td>Can accept HSD at 192 kbit/s;</td> </tr> <tr> <td>X_PHC_PV_HDATA_256</td> <td>Can accept HSD at 256 kbit/s;</td> </tr> <tr> <td>X_PHC_PV_HDATA_320</td> <td>Can accept HSD at 320 kbit/s;</td> </tr> <tr> <td>X_PHC_PV_HDATA_384</td> <td>Can accept HSD at 384 kbit/s;</td> </tr> <tr> <td>X_PHC_PV_HDATA_512</td> <td>Can accept HSD at 512 kbit/s (for future use only);</td> </tr> <tr> <td>X_PHC_PV_HDATA_768</td> <td>Can accept HSD at 768 kbit/s (for future use only);</td> </tr> <tr> <td>X_PHC_PV_HDATA_1152</td> <td>Can accept HSD at 1152 kbit/s (for future use only);</td> </tr> <tr> <td>X_PHC_PV_HDATA_1536</td> <td>Can accept HSD at 1536 kbit/s (for future use only);</td> </tr> <tr> <td>X_PHC_PV_HDATA_VAR</td> <td>Can accept variable rate of HSD;</td> </tr> <tr> <td>X_PHC_PV_HDATA_MLP62</td> <td>Can accept MLP at 62.4 kbit/s;</td> </tr> <tr> <td>X_PHC_PV_HDATA_MLP64</td> <td>Can accept MLP at 64 kbit/s;</td> </tr> <tr> <td>X_PHC_PV_HDATA_MLP128</td> <td>Can accept MLP at 128 kbit/s;</td> </tr> <tr> <td>X_PHC_PV_HDATA_MLP192</td> <td>Can accept MLP at 192 kbit/s;</td> </tr> <tr> <td>X_PHC_PV_HDATA_MLP256</td> <td>Can accept MLP at 256 kbit/s;</td> </tr> <tr> <td>X_PHC_PV_HDATA_MLP320</td> <td>Can accept MLP at 320 kbit/s;</td> </tr> <tr> <td>X_PHC_PV_HDATA_MLP384</td> <td>Can accept MLP at 384 kbit/s;</td> </tr> <tr> <td>X_PHC_PV_HDATA_VARMLP</td> <td>Can accept MLP at variable rate.</td> </tr> </table> <p>It is possible to select more then one of the high-speed data capabilities listed above. In this case the parameter values have to be combined using a bit-wise OR. Each parameter value sets one bit position of the X_PHC_P_LCAP_HDATA parameter.</p> | X_PHC_PV_CAPNON   | No HSD capability defined; | X_PHC_PV_HDATA_64  | Can accept HSD at 64 kbit/s; | X_PHC_PV_HDATA_128 | Can accept HSD at 128 kbit/s; | X_PHC_PV_HDATA_192 | Can accept HSD at 192 kbit/s; | X_PHC_PV_HDATA_256  | Can accept HSD at 256 kbit/s; | X_PHC_PV_HDATA_320 | Can accept HSD at 320 kbit/s; | X_PHC_PV_HDATA_384       | Can accept HSD at 384 kbit/s; | X_PHC_PV_HDATA_512    | Can accept HSD at 512 kbit/s (for future use only); | X_PHC_PV_HDATA_768    | Can accept HSD at 768 kbit/s (for future use only); | X_PHC_PV_HDATA_1152   | Can accept HSD at 1152 kbit/s (for future use only); | X_PHC_PV_HDATA_1536   | Can accept HSD at 1536 kbit/s (for future use only); | X_PHC_PV_HDATA_VAR | Can accept variable rate of HSD; | X_PHC_PV_HDATA_MLP62 | Can accept MLP at 62.4 kbit/s; | X_PHC_PV_HDATA_MLP64 | Can accept MLP at 64 kbit/s; | X_PHC_PV_HDATA_MLP128 | Can accept MLP at 128 kbit/s; | X_PHC_PV_HDATA_MLP192 | Can accept MLP at 192 kbit/s; | X_PHC_PV_HDATA_MLP256 | Can accept MLP at 256 kbit/s; | X_PHC_PV_HDATA_MLP320 | Can accept MLP at 320 kbit/s; | X_PHC_PV_HDATA_MLP384 | Can accept MLP at 384 kbit/s; | X_PHC_PV_HDATA_VARMLP | Can accept MLP at variable rate. |
+| X_PHC_PV_CAPNON          | No HSD capability defined;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |                   |                            |                    |                              |                    |                               |                    |                               |                     |                               |                    |                               |                          |                               |                       |                                                     |                       |                                                     |                       |                                                      |                       |                                                      |                    |                                  |                      |                                |                      |                              |                       |                               |                       |                               |                       |                               |                       |                               |                       |                               |                       |                                  |
+| X_PHC_PV_HDATA_64        | Can accept HSD at 64 kbit/s;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |                   |                            |                    |                              |                    |                               |                    |                               |                     |                               |                    |                               |                          |                               |                       |                                                     |                       |                                                     |                       |                                                      |                       |                                                      |                    |                                  |                      |                                |                      |                              |                       |                               |                       |                               |                       |                               |                       |                               |                       |                               |                       |                                  |
+| X_PHC_PV_HDATA_128       | Can accept HSD at 128 kbit/s;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |                   |                            |                    |                              |                    |                               |                    |                               |                     |                               |                    |                               |                          |                               |                       |                                                     |                       |                                                     |                       |                                                      |                       |                                                      |                    |                                  |                      |                                |                      |                              |                       |                               |                       |                               |                       |                               |                       |                               |                       |                               |                       |                                  |
+| X_PHC_PV_HDATA_192       | Can accept HSD at 192 kbit/s;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |                   |                            |                    |                              |                    |                               |                    |                               |                     |                               |                    |                               |                          |                               |                       |                                                     |                       |                                                     |                       |                                                      |                       |                                                      |                    |                                  |                      |                                |                      |                              |                       |                               |                       |                               |                       |                               |                       |                               |                       |                               |                       |                                  |
+| X_PHC_PV_HDATA_256       | Can accept HSD at 256 kbit/s;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |                   |                            |                    |                              |                    |                               |                    |                               |                     |                               |                    |                               |                          |                               |                       |                                                     |                       |                                                     |                       |                                                      |                       |                                                      |                    |                                  |                      |                                |                      |                              |                       |                               |                       |                               |                       |                               |                       |                               |                       |                               |                       |                                  |
+| X_PHC_PV_HDATA_320       | Can accept HSD at 320 kbit/s;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |                   |                            |                    |                              |                    |                               |                    |                               |                     |                               |                    |                               |                          |                               |                       |                                                     |                       |                                                     |                       |                                                      |                       |                                                      |                    |                                  |                      |                                |                      |                              |                       |                               |                       |                               |                       |                               |                       |                               |                       |                               |                       |                                  |
+| X_PHC_PV_HDATA_384       | Can accept HSD at 384 kbit/s;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |                   |                            |                    |                              |                    |                               |                    |                               |                     |                               |                    |                               |                          |                               |                       |                                                     |                       |                                                     |                       |                                                      |                       |                                                      |                    |                                  |                      |                                |                      |                              |                       |                               |                       |                               |                       |                               |                       |                               |                       |                               |                       |                                  |
+| X_PHC_PV_HDATA_512       | Can accept HSD at 512 kbit/s (for future use only);                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |                   |                            |                    |                              |                    |                               |                    |                               |                     |                               |                    |                               |                          |                               |                       |                                                     |                       |                                                     |                       |                                                      |                       |                                                      |                    |                                  |                      |                                |                      |                              |                       |                               |                       |                               |                       |                               |                       |                               |                       |                               |                       |                                  |
+| X_PHC_PV_HDATA_768       | Can accept HSD at 768 kbit/s (for future use only);                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |                   |                            |                    |                              |                    |                               |                    |                               |                     |                               |                    |                               |                          |                               |                       |                                                     |                       |                                                     |                       |                                                      |                       |                                                      |                    |                                  |                      |                                |                      |                              |                       |                               |                       |                               |                       |                               |                       |                               |                       |                               |                       |                                  |
+| X_PHC_PV_HDATA_1152      | Can accept HSD at 1152 kbit/s (for future use only);                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |                   |                            |                    |                              |                    |                               |                    |                               |                     |                               |                    |                               |                          |                               |                       |                                                     |                       |                                                     |                       |                                                      |                       |                                                      |                    |                                  |                      |                                |                      |                              |                       |                               |                       |                               |                       |                               |                       |                               |                       |                               |                       |                                  |
+| X_PHC_PV_HDATA_1536      | Can accept HSD at 1536 kbit/s (for future use only);                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |                   |                            |                    |                              |                    |                               |                    |                               |                     |                               |                    |                               |                          |                               |                       |                                                     |                       |                                                     |                       |                                                      |                       |                                                      |                    |                                  |                      |                                |                      |                              |                       |                               |                       |                               |                       |                               |                       |                               |                       |                               |                       |                                  |
+| X_PHC_PV_HDATA_VAR       | Can accept variable rate of HSD;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |                   |                            |                    |                              |                    |                               |                    |                               |                     |                               |                    |                               |                          |                               |                       |                                                     |                       |                                                     |                       |                                                      |                       |                                                      |                    |                                  |                      |                                |                      |                              |                       |                               |                       |                               |                       |                               |                       |                               |                       |                               |                       |                                  |
+| X_PHC_PV_HDATA_MLP62     | Can accept MLP at 62.4 kbit/s;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |                   |                            |                    |                              |                    |                               |                    |                               |                     |                               |                    |                               |                          |                               |                       |                                                     |                       |                                                     |                       |                                                      |                       |                                                      |                    |                                  |                      |                                |                      |                              |                       |                               |                       |                               |                       |                               |                       |                               |                       |                               |                       |                                  |
+| X_PHC_PV_HDATA_MLP64     | Can accept MLP at 64 kbit/s;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |                   |                            |                    |                              |                    |                               |                    |                               |                     |                               |                    |                               |                          |                               |                       |                                                     |                       |                                                     |                       |                                                      |                       |                                                      |                    |                                  |                      |                                |                      |                              |                       |                               |                       |                               |                       |                               |                       |                               |                       |                               |                       |                                  |
+| X_PHC_PV_HDATA_MLP128    | Can accept MLP at 128 kbit/s;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |                   |                            |                    |                              |                    |                               |                    |                               |                     |                               |                    |                               |                          |                               |                       |                                                     |                       |                                                     |                       |                                                      |                       |                                                      |                    |                                  |                      |                                |                      |                              |                       |                               |                       |                               |                       |                               |                       |                               |                       |                               |                       |                                  |
+| X_PHC_PV_HDATA_MLP192    | Can accept MLP at 192 kbit/s;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |                   |                            |                    |                              |                    |                               |                    |                               |                     |                               |                    |                               |                          |                               |                       |                                                     |                       |                                                     |                       |                                                      |                       |                                                      |                    |                                  |                      |                                |                      |                              |                       |                               |                       |                               |                       |                               |                       |                               |                       |                               |                       |                                  |
+| X_PHC_PV_HDATA_MLP256    | Can accept MLP at 256 kbit/s;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |                   |                            |                    |                              |                    |                               |                    |                               |                     |                               |                    |                               |                          |                               |                       |                                                     |                       |                                                     |                       |                                                      |                       |                                                      |                    |                                  |                      |                                |                      |                              |                       |                               |                       |                               |                       |                               |                       |                               |                       |                               |                       |                                  |
+| X_PHC_PV_HDATA_MLP320    | Can accept MLP at 320 kbit/s;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |                   |                            |                    |                              |                    |                               |                    |                               |                     |                               |                    |                               |                          |                               |                       |                                                     |                       |                                                     |                       |                                                      |                       |                                                      |                    |                                  |                      |                                |                      |                              |                       |                               |                       |                               |                       |                               |                       |                               |                       |                               |                       |                                  |
+| X_PHC_PV_HDATA_MLP384    | Can accept MLP at 384 kbit/s;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |                   |                            |                    |                              |                    |                               |                    |                               |                     |                               |                    |                               |                          |                               |                       |                                                     |                       |                                                     |                       |                                                      |                       |                                                      |                    |                                  |                      |                                |                      |                              |                       |                               |                       |                               |                       |                               |                       |                               |                       |                               |                       |                                  |
+| X_PHC_PV_HDATA_VARMLP    | Can accept MLP at variable rate.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |                   |                            |                    |                              |                    |                               |                    |                               |                     |                               |                    |                               |                          |                               |                       |                                                     |                       |                                                     |                       |                                                      |                       |                                                      |                    |                                  |                      |                                |                      |                              |                       |                               |                       |                               |                       |                               |                       |                               |                       |                               |                       |                                  |
+
+**Table I.5-12/T.180**
+
+|                      |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |                 |                                      |                     |                                                |                     |                                                |                     |                                                |                     |                                                |                     |                                                |                      |                                                 |                      |                                                 |
+|----------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------|--------------------------------------|---------------------|------------------------------------------------|---------------------|------------------------------------------------|---------------------|------------------------------------------------|---------------------|------------------------------------------------|---------------------|------------------------------------------------|----------------------|-------------------------------------------------|----------------------|-------------------------------------------------|
+| Parameter name       | X_PHC_P_LCAP_TFRATE                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |                 |                                      |                     |                                                |                     |                                                |                     |                                                |                     |                                                |                     |                                                |                      |                                                 |                      |                                                 |
+| Type of value        | long                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |                 |                                      |                     |                                                |                     |                                                |                     |                                                |                     |                                                |                     |                                                |                      |                                                 |                      |                                                 |
+| Legal values         | X_PHC_PV_CAPNON<br>X_PHC_PV_TFRATE_128<br>X_PHC_PV_TFRATE_192<br>X_PHC_PV_TFRATE_256<br>X_PHC_PV_TFRATE_512<br>X_PHC_PV_TFRATE_768<br>X_PHC_PV_TFRATE_1152<br>X_PHC_PV_TFRATE_1472                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |                 |                                      |                     |                                                |                     |                                                |                     |                                                |                     |                                                |                     |                                                |                      |                                                 |                      |                                                 |
+| Default value        | The default value is defined by the value of the X_PHC_O_LCAP_TFRATE option.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |                 |                                      |                     |                                                |                     |                                                |                     |                                                |                     |                                                |                     |                                                |                      |                                                 |                      |                                                 |
+| Description          | <p>The parameter specifies the transfer rate reception capabilities of the local receiver. The parameter values correspond to the transfer rate capabilities defined in the BAS table of Recommendation H.221:</p> <table> <tr> <td>X_PHC_PV_CAPNON</td> <td>No transfer rate capability defined;</td> </tr> <tr> <td>X_PHC_PV_TFRATE_128</td> <td>Capable of accepting transfer rate 128 kbit/s;</td> </tr> <tr> <td>X_PHC_PV_TFRATE_192</td> <td>Capable of accepting transfer rate 192 kbit/s;</td> </tr> <tr> <td>X_PHC_PV_TFRATE_256</td> <td>Capable of accepting transfer rate 256 kbit/s;</td> </tr> <tr> <td>X_PHC_PV_TFRATE_512</td> <td>Capable of accepting transfer rate 512 kbit/s;</td> </tr> <tr> <td>X_PHC_PV_TFRATE_768</td> <td>Capable of accepting transfer rate 768 kbit/s;</td> </tr> <tr> <td>X_PHC_PV_TFRATE_1152</td> <td>Capable of accepting transfer rate 1152 kbit/s;</td> </tr> <tr> <td>X_PHC_PV_TFRATE_1472</td> <td>Capable of accepting transfer rate 1472 kbit/s.</td> </tr> </table> <p>It is possible to select more then one of the transfer rate capabilities listed above. In this case the parameter values have to be combined using a bit-wise OR. Each parameter value sets one bit position of the X_PHC_P_LCAP_TFRATE parameter.</p> | X_PHC_PV_CAPNON | No transfer rate capability defined; | X_PHC_PV_TFRATE_128 | Capable of accepting transfer rate 128 kbit/s; | X_PHC_PV_TFRATE_192 | Capable of accepting transfer rate 192 kbit/s; | X_PHC_PV_TFRATE_256 | Capable of accepting transfer rate 256 kbit/s; | X_PHC_PV_TFRATE_512 | Capable of accepting transfer rate 512 kbit/s; | X_PHC_PV_TFRATE_768 | Capable of accepting transfer rate 768 kbit/s; | X_PHC_PV_TFRATE_1152 | Capable of accepting transfer rate 1152 kbit/s; | X_PHC_PV_TFRATE_1472 | Capable of accepting transfer rate 1472 kbit/s. |
+| X_PHC_PV_CAPNON      | No transfer rate capability defined;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |                 |                                      |                     |                                                |                     |                                                |                     |                                                |                     |                                                |                     |                                                |                      |                                                 |                      |                                                 |
+| X_PHC_PV_TFRATE_128  | Capable of accepting transfer rate 128 kbit/s;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |                 |                                      |                     |                                                |                     |                                                |                     |                                                |                     |                                                |                     |                                                |                      |                                                 |                      |                                                 |
+| X_PHC_PV_TFRATE_192  | Capable of accepting transfer rate 192 kbit/s;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |                 |                                      |                     |                                                |                     |                                                |                     |                                                |                     |                                                |                     |                                                |                      |                                                 |                      |                                                 |
+| X_PHC_PV_TFRATE_256  | Capable of accepting transfer rate 256 kbit/s;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |                 |                                      |                     |                                                |                     |                                                |                     |                                                |                     |                                                |                     |                                                |                      |                                                 |                      |                                                 |
+| X_PHC_PV_TFRATE_512  | Capable of accepting transfer rate 512 kbit/s;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |                 |                                      |                     |                                                |                     |                                                |                     |                                                |                     |                                                |                     |                                                |                      |                                                 |                      |                                                 |
+| X_PHC_PV_TFRATE_768  | Capable of accepting transfer rate 768 kbit/s;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |                 |                                      |                     |                                                |                     |                                                |                     |                                                |                     |                                                |                     |                                                |                      |                                                 |                      |                                                 |
+| X_PHC_PV_TFRATE_1152 | Capable of accepting transfer rate 1152 kbit/s;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |                 |                                      |                     |                                                |                     |                                                |                     |                                                |                     |                                                |                     |                                                |                      |                                                 |                      |                                                 |
+| X_PHC_PV_TFRATE_1472 | Capable of accepting transfer rate 1472 kbit/s.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |                 |                                      |                     |                                                |                     |                                                |                     |                                                |                     |                                                |                     |                                                |                      |                                                 |                      |                                                 |
+
+**Table I.5-13/T.180**
+
+|                      |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |                     |                                                   |                     |                                                      |                     |                                                        |                     |                                                       |                     |                                                       |                     |                                                      |                     |                                               |                     |                                                       |                     |                                                         |                     |                                                        |                     |                                                        |                      |                                              |                      |                                              |
+|----------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------|---------------------------------------------------|---------------------|------------------------------------------------------|---------------------|--------------------------------------------------------|---------------------|-------------------------------------------------------|---------------------|-------------------------------------------------------|---------------------|------------------------------------------------------|---------------------|-----------------------------------------------|---------------------|-------------------------------------------------------|---------------------|---------------------------------------------------------|---------------------|--------------------------------------------------------|---------------------|--------------------------------------------------------|----------------------|----------------------------------------------|----------------------|----------------------------------------------|
+| Parameter name       | X_PHC_P_LCAP_TFLINES                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |                     |                                                   |                     |                                                      |                     |                                                        |                     |                                                       |                     |                                                       |                     |                                                      |                     |                                               |                     |                                                       |                     |                                                         |                     |                                                        |                     |                                                        |                      |                                              |                      |                                              |
+| Type of value        | long                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |                     |                                                   |                     |                                                      |                     |                                                        |                     |                                                       |                     |                                                       |                     |                                                      |                     |                                               |                     |                                                       |                     |                                                         |                     |                                                        |                     |                                                        |                      |                                              |                      |                                              |
+| Legal values         | X_PHC_PV_TFLINES_1B<br>X_PHC_PV_TFLINES_2B<br>X_PHC_PV_TFLINES_3B<br>X_PHC_PV_TFLINES_4B<br>X_PHC_PV_TFLINES_5B<br>X_PHC_PV_TFLINES_6B<br>X_PHC_PV_TFLINES_1H<br>X_PHC_PV_TFLINES_2H<br>X_PHC_PV_TFLINES_3H<br>X_PHC_PV_TFLINES_4H<br>X_PHC_PV_TFLINES_5H<br>X_PHC_PV_TFLINES_H11<br>X_PHC_PV_TFLINES_H12                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |                     |                                                   |                     |                                                      |                     |                                                        |                     |                                                       |                     |                                                       |                     |                                                      |                     |                                               |                     |                                                       |                     |                                                         |                     |                                                        |                     |                                                        |                      |                                              |                      |                                              |
+| Default value        | The default value is defined by the value of the X_PHC_O_LCAP_TFLINES option.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |                     |                                                   |                     |                                                      |                     |                                                        |                     |                                                       |                     |                                                       |                     |                                                      |                     |                                               |                     |                                                       |                     |                                                         |                     |                                                        |                     |                                                        |                      |                                              |                      |                                              |
+| Description          | <p>The parameter specifies the transfer line reception capabilities of the local receiver. The parameter values correspond to the transfer line capabilities defined in the BAS table of Recommendation H.221:</p> <table data-bbox="403 925 1412 1680"> <tr> <td>X_PHC_PV_TFLINES_1B</td> <td>Can handle AV data on one 64 kbit/s channel only;</td> </tr> <tr> <td>X_PHC_PV_TFLINES_2B</td> <td>Can handle AV data on one or two 64 kbit/s channels;</td> </tr> <tr> <td>X_PHC_PV_TFLINES_3B</td> <td>Can handle AV data on one to three 64 kbit/s channels;</td> </tr> <tr> <td>X_PHC_PV_TFLINES_4B</td> <td>Can handle AV data on one to four 64 kbit/s channels;</td> </tr> <tr> <td>X_PHC_PV_TFLINES_5B</td> <td>Can handle AV data on one to five 64 kbit/s channels;</td> </tr> <tr> <td>X_PHC_PV_TFLINES_6B</td> <td>Can handle AV data on one to six 64 kbit/s channels;</td> </tr> <tr> <td>X_PHC_PV_TFLINES_1H</td> <td>Can handle AV data on one 384 kbit/s channel;</td> </tr> <tr> <td>X_PHC_PV_TFLINES_2H</td> <td>Can handle AV data on one or two 384 kbit/s channels;</td> </tr> <tr> <td>X_PHC_PV_TFLINES_3H</td> <td>Can handle AV data on one to three 384 kbit/s channels;</td> </tr> <tr> <td>X_PHC_PV_TFLINES_4H</td> <td>Can handle AV data on one to four 384 kbit/s channels;</td> </tr> <tr> <td>X_PHC_PV_TFLINES_5H</td> <td>Can handle AV data on one to five 384 kbit/s channels;</td> </tr> <tr> <td>X_PHC_PV_TFLINES_H11</td> <td>Can handle AV data on a 1536 kbit/s channel;</td> </tr> <tr> <td>X_PHC_PV_TFLINES_H12</td> <td>Can handle AV data on a 1920 kbit/s channel.</td> </tr> </table> <p>The selected parameter value defines the maximum number of transfer lines which can be handled by the local receiver. According to Recommendation H.242 the transfer lines capability has an explicit meaning (the ability to handle as many channels as indicated) but also an implicit meaning. The calling terminal implicitly signals its intention to establish the indicated number of channels and the called terminal implicitly signals its intention to accept the indicated number of connections.</p> | X_PHC_PV_TFLINES_1B | Can handle AV data on one 64 kbit/s channel only; | X_PHC_PV_TFLINES_2B | Can handle AV data on one or two 64 kbit/s channels; | X_PHC_PV_TFLINES_3B | Can handle AV data on one to three 64 kbit/s channels; | X_PHC_PV_TFLINES_4B | Can handle AV data on one to four 64 kbit/s channels; | X_PHC_PV_TFLINES_5B | Can handle AV data on one to five 64 kbit/s channels; | X_PHC_PV_TFLINES_6B | Can handle AV data on one to six 64 kbit/s channels; | X_PHC_PV_TFLINES_1H | Can handle AV data on one 384 kbit/s channel; | X_PHC_PV_TFLINES_2H | Can handle AV data on one or two 384 kbit/s channels; | X_PHC_PV_TFLINES_3H | Can handle AV data on one to three 384 kbit/s channels; | X_PHC_PV_TFLINES_4H | Can handle AV data on one to four 384 kbit/s channels; | X_PHC_PV_TFLINES_5H | Can handle AV data on one to five 384 kbit/s channels; | X_PHC_PV_TFLINES_H11 | Can handle AV data on a 1536 kbit/s channel; | X_PHC_PV_TFLINES_H12 | Can handle AV data on a 1920 kbit/s channel. |
+| X_PHC_PV_TFLINES_1B  | Can handle AV data on one 64 kbit/s channel only;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |                     |                                                   |                     |                                                      |                     |                                                        |                     |                                                       |                     |                                                       |                     |                                                      |                     |                                               |                     |                                                       |                     |                                                         |                     |                                                        |                     |                                                        |                      |                                              |                      |                                              |
+| X_PHC_PV_TFLINES_2B  | Can handle AV data on one or two 64 kbit/s channels;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |                     |                                                   |                     |                                                      |                     |                                                        |                     |                                                       |                     |                                                       |                     |                                                      |                     |                                               |                     |                                                       |                     |                                                         |                     |                                                        |                     |                                                        |                      |                                              |                      |                                              |
+| X_PHC_PV_TFLINES_3B  | Can handle AV data on one to three 64 kbit/s channels;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |                     |                                                   |                     |                                                      |                     |                                                        |                     |                                                       |                     |                                                       |                     |                                                      |                     |                                               |                     |                                                       |                     |                                                         |                     |                                                        |                     |                                                        |                      |                                              |                      |                                              |
+| X_PHC_PV_TFLINES_4B  | Can handle AV data on one to four 64 kbit/s channels;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |                     |                                                   |                     |                                                      |                     |                                                        |                     |                                                       |                     |                                                       |                     |                                                      |                     |                                               |                     |                                                       |                     |                                                         |                     |                                                        |                     |                                                        |                      |                                              |                      |                                              |
+| X_PHC_PV_TFLINES_5B  | Can handle AV data on one to five 64 kbit/s channels;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |                     |                                                   |                     |                                                      |                     |                                                        |                     |                                                       |                     |                                                       |                     |                                                      |                     |                                               |                     |                                                       |                     |                                                         |                     |                                                        |                     |                                                        |                      |                                              |                      |                                              |
+| X_PHC_PV_TFLINES_6B  | Can handle AV data on one to six 64 kbit/s channels;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |                     |                                                   |                     |                                                      |                     |                                                        |                     |                                                       |                     |                                                       |                     |                                                      |                     |                                               |                     |                                                       |                     |                                                         |                     |                                                        |                     |                                                        |                      |                                              |                      |                                              |
+| X_PHC_PV_TFLINES_1H  | Can handle AV data on one 384 kbit/s channel;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |                     |                                                   |                     |                                                      |                     |                                                        |                     |                                                       |                     |                                                       |                     |                                                      |                     |                                               |                     |                                                       |                     |                                                         |                     |                                                        |                     |                                                        |                      |                                              |                      |                                              |
+| X_PHC_PV_TFLINES_2H  | Can handle AV data on one or two 384 kbit/s channels;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |                     |                                                   |                     |                                                      |                     |                                                        |                     |                                                       |                     |                                                       |                     |                                                      |                     |                                               |                     |                                                       |                     |                                                         |                     |                                                        |                     |                                                        |                      |                                              |                      |                                              |
+| X_PHC_PV_TFLINES_3H  | Can handle AV data on one to three 384 kbit/s channels;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |                     |                                                   |                     |                                                      |                     |                                                        |                     |                                                       |                     |                                                       |                     |                                                      |                     |                                               |                     |                                                       |                     |                                                         |                     |                                                        |                     |                                                        |                      |                                              |                      |                                              |
+| X_PHC_PV_TFLINES_4H  | Can handle AV data on one to four 384 kbit/s channels;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |                     |                                                   |                     |                                                      |                     |                                                        |                     |                                                       |                     |                                                       |                     |                                                      |                     |                                               |                     |                                                       |                     |                                                         |                     |                                                        |                     |                                                        |                      |                                              |                      |                                              |
+| X_PHC_PV_TFLINES_5H  | Can handle AV data on one to five 384 kbit/s channels;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |                     |                                                   |                     |                                                      |                     |                                                        |                     |                                                       |                     |                                                       |                     |                                                      |                     |                                               |                     |                                                       |                     |                                                         |                     |                                                        |                     |                                                        |                      |                                              |                      |                                              |
+| X_PHC_PV_TFLINES_H11 | Can handle AV data on a 1536 kbit/s channel;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |                     |                                                   |                     |                                                      |                     |                                                        |                     |                                                       |                     |                                                       |                     |                                                      |                     |                                               |                     |                                                       |                     |                                                         |                     |                                                        |                     |                                                        |                      |                                              |                      |                                              |
+| X_PHC_PV_TFLINES_H12 | Can handle AV data on a 1920 kbit/s channel.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |                     |                                                   |                     |                                                      |                     |                                                        |                     |                                                       |                     |                                                       |                     |                                                      |                     |                                               |                     |                                                       |                     |                                                         |                     |                                                        |                     |                                                        |                      |                                              |                      |                                              |
+
+**Table I.5-14/T.180**
+
+|                        |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |                 |                                     |                    |                                                        |                   |                                                      |                   |                                                       |                        |                                                         |                       |                                                                             |
+|------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------|-------------------------------------|--------------------|--------------------------------------------------------|-------------------|------------------------------------------------------|-------------------|-------------------------------------------------------|------------------------|---------------------------------------------------------|-----------------------|-----------------------------------------------------------------------------|
+| Parameter name         | X_PHC_P_LCAP_MISC                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |                 |                                     |                    |                                                        |                   |                                                      |                   |                                                       |                        |                                                         |                       |                                                                             |
+| Type of value          | long                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |                 |                                     |                    |                                                        |                   |                                                      |                   |                                                       |                        |                                                         |                       |                                                                             |
+| Legal values           | X_PHC_PV_CAPNON<br>X_PHC_PV_MISC_ENCR<br>X_PHC_PV_MISC_ESC<br>X_PHC_PV_MISC_MBE<br>X_PHC_PV_MISC_RESTRICT<br>X_PHC_PV_MISC_6BHCOMP                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |                 |                                     |                    |                                                        |                   |                                                      |                   |                                                       |                        |                                                         |                       |                                                                             |
+| Default value          | The default value is defined by the value of the X_PHC_O_LCAP_MISC option.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |                 |                                     |                    |                                                        |                   |                                                      |                   |                                                       |                        |                                                         |                       |                                                                             |
+| Description            | <p>The parameter specifies the miscellaneous reception capabilities of the local receiver. The parameter values correspond to the capabilities defined in the BAS table of Recommendation H.221:</p> <table> <tr> <td>X_PHC_PV_CAPNON</td> <td>No capability of this type defined;</td> </tr> <tr> <td>X_PHC_PV_MISC_ENCR</td> <td>Capable of handling the encryption on the ECS channel;</td> </tr> <tr> <td>X_PHC_PV_MISC_ESC</td> <td>Capable of accepting non-zero call/family ESC codes;</td> </tr> <tr> <td>X_PHC_PV_MISC_MBE</td> <td>Capable of handling multiple-byte extension messages;</td> </tr> <tr> <td>X_PHC_PV_MISC_RESTRICT</td> <td>Restricted mode: can work only at <math>p \times 56</math> kbit/s;</td> </tr> <tr> <td>X_PHC_PV_MISC_6BHCOMP</td> <td>Capable of providing compatibility between 6B and H<sub>0</sub> terminals.</td> </tr> </table> <p>It is possible to select more than one of the miscellaneous capabilities listed above. In this case the parameter values have to be combined using a bit-wise OR. Each parameter value sets one bit position of the X_PHC_P_LCAP_MISC parameter.</p> | X_PHC_PV_CAPNON | No capability of this type defined; | X_PHC_PV_MISC_ENCR | Capable of handling the encryption on the ECS channel; | X_PHC_PV_MISC_ESC | Capable of accepting non-zero call/family ESC codes; | X_PHC_PV_MISC_MBE | Capable of handling multiple-byte extension messages; | X_PHC_PV_MISC_RESTRICT | Restricted mode: can work only at $p \times 56$ kbit/s; | X_PHC_PV_MISC_6BHCOMP | Capable of providing compatibility between 6B and H <sub>0</sub> terminals. |
+| X_PHC_PV_CAPNON        | No capability of this type defined;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |                 |                                     |                    |                                                        |                   |                                                      |                   |                                                       |                        |                                                         |                       |                                                                             |
+| X_PHC_PV_MISC_ENCR     | Capable of handling the encryption on the ECS channel;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |                 |                                     |                    |                                                        |                   |                                                      |                   |                                                       |                        |                                                         |                       |                                                                             |
+| X_PHC_PV_MISC_ESC      | Capable of accepting non-zero call/family ESC codes;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |                 |                                     |                    |                                                        |                   |                                                      |                   |                                                       |                        |                                                         |                       |                                                                             |
+| X_PHC_PV_MISC_MBE      | Capable of handling multiple-byte extension messages;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |                 |                                     |                    |                                                        |                   |                                                      |                   |                                                       |                        |                                                         |                       |                                                                             |
+| X_PHC_PV_MISC_RESTRICT | Restricted mode: can work only at $p \times 56$ kbit/s;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |                 |                                     |                    |                                                        |                   |                                                      |                   |                                                       |                        |                                                         |                       |                                                                             |
+| X_PHC_PV_MISC_6BHCOMP  | Capable of providing compatibility between 6B and H <sub>0</sub> terminals.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |                 |                                     |                    |                                                        |                   |                                                      |                   |                                                       |                        |                                                         |                       |                                                                             |
+
+**Table I.5-15/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                      |
+|----------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_PHC_P_LCAP_DATAPPL                                                                                                                                                                                                                                                                                                                 |
+| Type of value  | long                                                                                                                                                                                                                                                                                                                                 |
+| Legal values   | X_PHC_PV_CAPNON<br>X_PHC_PV_APPL_STILLPIC_LSD<br>X_PHC_PV_APPL_STILLPIC_HSD<br>X_PHC_PV_APPL_STILLPIC_SPATIAL<br>X_PHC_PV_APPL_STILLPIC_PROG<br>X_PHC_PV_APPL_STILLPIC_ARITH<br>X_PHC_PV_APPL_STILLIMAGE<br>X_PHC_PV_APPL_CURSORDATA<br>X_PHC_PV_APPL_FAX3<br>X_PHC_PV_APPL_FAX4<br>X_PHC_PV_APPL_V120_LSD<br>X_PHC_PV_APPL_V120_HSD |
+
+**Table I.5-15/T.180 (concluded)**
+
+|                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |                 |                                     |                            |                                                        |                            |                                                        |                                |                                                     |                             |                                                         |                              |                                                        |                          |                                                                   |                          |                                 |                    |                                |                    |                                |                        |                                                  |                        |                                                  |
+|--------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------|-------------------------------------|----------------------------|--------------------------------------------------------|----------------------------|--------------------------------------------------------|--------------------------------|-----------------------------------------------------|-----------------------------|---------------------------------------------------------|------------------------------|--------------------------------------------------------|--------------------------|-------------------------------------------------------------------|--------------------------|---------------------------------|--------------------|--------------------------------|--------------------|--------------------------------|------------------------|--------------------------------------------------|------------------------|--------------------------------------------------|
+| Default value                  | The default value is defined by the value of the X_PHC_O_LCAP_DATAPPL option.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |                 |                                     |                            |                                                        |                            |                                                        |                                |                                                     |                             |                                                         |                              |                                                        |                          |                                                                   |                          |                                 |                    |                                |                    |                                |                        |                                                  |                        |                                                  |
+| Description                    | <p>The parameter specifies the reception application capabilities within LSD/HSD channels of the local receiver. The parameter values correspond to the capabilities defined in the BAS table of Recommendation H.221:</p> <table style="width: 100%; border: none;"> <tr><td style="width: 40%;">X_PHC_PV_CAPNON</td><td>No capability of this type defined;</td></tr> <tr><td>X_PHC_PV_APPL_STILLPIC_LSD</td><td>Capable of the ISO still picture baseline mode on LSD;</td></tr> <tr><td>X_PHC_PV_APPL_STILLPIC_HSD</td><td>Capable of the ISO still picture baseline mode on HSD;</td></tr> <tr><td>X_PHC_PV_APPL_STILLPIC_SPATIAL</td><td>Capable of the ISO still picture and spatial modes;</td></tr> <tr><td>X_PHC_PV_APPL_STILLPIC_PROG</td><td>Capable of the ISO still picture and progressive modes;</td></tr> <tr><td>X_PHC_PV_APPL_STILLPIC_ARITH</td><td>Capable of the ISO still picture and arithmetic modes;</td></tr> <tr><td>X_PHC_PV_APPL_STILLIMAGE</td><td>Capable of still image encoded according to Recommendation H.261;</td></tr> <tr><td>X_PHC_PV_APPL_CURSORDATA</td><td>Can handle graphic cursor data;</td></tr> <tr><td>X_PHC_PV_APPL_FAX3</td><td>Capable receiving Fax group 3;</td></tr> <tr><td>X_PHC_PV_APPL_FAX4</td><td>Capable receiving Fax group 4;</td></tr> <tr><td>X_PHC_PV_APPL_V120_LSD</td><td>Capable of V.120 terminal adaptation within LSD;</td></tr> <tr><td>X_PHC_PV_APPL_V120_HSD</td><td>Capable of V.120 terminal adaptation within HSD.</td></tr> </table> <p>It is possible to select more than one of the application capabilities listed above. In this case the parameter values have to be combined using a bit-wise OR. Each parameter value sets one bit position of the X_PHC_P_LCAP_DATAPPL parameter.</p> | X_PHC_PV_CAPNON | No capability of this type defined; | X_PHC_PV_APPL_STILLPIC_LSD | Capable of the ISO still picture baseline mode on LSD; | X_PHC_PV_APPL_STILLPIC_HSD | Capable of the ISO still picture baseline mode on HSD; | X_PHC_PV_APPL_STILLPIC_SPATIAL | Capable of the ISO still picture and spatial modes; | X_PHC_PV_APPL_STILLPIC_PROG | Capable of the ISO still picture and progressive modes; | X_PHC_PV_APPL_STILLPIC_ARITH | Capable of the ISO still picture and arithmetic modes; | X_PHC_PV_APPL_STILLIMAGE | Capable of still image encoded according to Recommendation H.261; | X_PHC_PV_APPL_CURSORDATA | Can handle graphic cursor data; | X_PHC_PV_APPL_FAX3 | Capable receiving Fax group 3; | X_PHC_PV_APPL_FAX4 | Capable receiving Fax group 4; | X_PHC_PV_APPL_V120_LSD | Capable of V.120 terminal adaptation within LSD; | X_PHC_PV_APPL_V120_HSD | Capable of V.120 terminal adaptation within HSD. |
+| X_PHC_PV_CAPNON                | No capability of this type defined;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |                 |                                     |                            |                                                        |                            |                                                        |                                |                                                     |                             |                                                         |                              |                                                        |                          |                                                                   |                          |                                 |                    |                                |                    |                                |                        |                                                  |                        |                                                  |
+| X_PHC_PV_APPL_STILLPIC_LSD     | Capable of the ISO still picture baseline mode on LSD;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |                 |                                     |                            |                                                        |                            |                                                        |                                |                                                     |                             |                                                         |                              |                                                        |                          |                                                                   |                          |                                 |                    |                                |                    |                                |                        |                                                  |                        |                                                  |
+| X_PHC_PV_APPL_STILLPIC_HSD     | Capable of the ISO still picture baseline mode on HSD;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |                 |                                     |                            |                                                        |                            |                                                        |                                |                                                     |                             |                                                         |                              |                                                        |                          |                                                                   |                          |                                 |                    |                                |                    |                                |                        |                                                  |                        |                                                  |
+| X_PHC_PV_APPL_STILLPIC_SPATIAL | Capable of the ISO still picture and spatial modes;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |                 |                                     |                            |                                                        |                            |                                                        |                                |                                                     |                             |                                                         |                              |                                                        |                          |                                                                   |                          |                                 |                    |                                |                    |                                |                        |                                                  |                        |                                                  |
+| X_PHC_PV_APPL_STILLPIC_PROG    | Capable of the ISO still picture and progressive modes;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |                 |                                     |                            |                                                        |                            |                                                        |                                |                                                     |                             |                                                         |                              |                                                        |                          |                                                                   |                          |                                 |                    |                                |                    |                                |                        |                                                  |                        |                                                  |
+| X_PHC_PV_APPL_STILLPIC_ARITH   | Capable of the ISO still picture and arithmetic modes;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |                 |                                     |                            |                                                        |                            |                                                        |                                |                                                     |                             |                                                         |                              |                                                        |                          |                                                                   |                          |                                 |                    |                                |                    |                                |                        |                                                  |                        |                                                  |
+| X_PHC_PV_APPL_STILLIMAGE       | Capable of still image encoded according to Recommendation H.261;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |                 |                                     |                            |                                                        |                            |                                                        |                                |                                                     |                             |                                                         |                              |                                                        |                          |                                                                   |                          |                                 |                    |                                |                    |                                |                        |                                                  |                        |                                                  |
+| X_PHC_PV_APPL_CURSORDATA       | Can handle graphic cursor data;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |                 |                                     |                            |                                                        |                            |                                                        |                                |                                                     |                             |                                                         |                              |                                                        |                          |                                                                   |                          |                                 |                    |                                |                    |                                |                        |                                                  |                        |                                                  |
+| X_PHC_PV_APPL_FAX3             | Capable receiving Fax group 3;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |                 |                                     |                            |                                                        |                            |                                                        |                                |                                                     |                             |                                                         |                              |                                                        |                          |                                                                   |                          |                                 |                    |                                |                    |                                |                        |                                                  |                        |                                                  |
+| X_PHC_PV_APPL_FAX4             | Capable receiving Fax group 4;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |                 |                                     |                            |                                                        |                            |                                                        |                                |                                                     |                             |                                                         |                              |                                                        |                          |                                                                   |                          |                                 |                    |                                |                    |                                |                        |                                                  |                        |                                                  |
+| X_PHC_PV_APPL_V120_LSD         | Capable of V.120 terminal adaptation within LSD;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |                 |                                     |                            |                                                        |                            |                                                        |                                |                                                     |                             |                                                         |                              |                                                        |                          |                                                                   |                          |                                 |                    |                                |                    |                                |                        |                                                  |                        |                                                  |
+| X_PHC_PV_APPL_V120_HSD         | Capable of V.120 terminal adaptation within HSD.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |                 |                                     |                            |                                                        |                            |                                                        |                                |                                                     |                             |                                                         |                              |                                                        |                          |                                                                   |                          |                                 |                    |                                |                    |                                |                        |                                                  |                        |                                                  |
+
+**Table I.5-16/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |          |                                                |          |               |             |                                        |            |                              |
+|----------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------|------------------------------------------------|----------|---------------|-------------|----------------------------------------|------------|------------------------------|
+| Parameter name | X_PHC_P_LCAP_NONSTD                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |          |                                                |          |               |             |                                        |            |                              |
+| Type of value  | unsigned char [ ], 5 ... 255 bytes<br>or no value at all to revoke a previously specified non-standard capability                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |          |                                                |          |               |             |                                        |            |                              |
+| Legal values   | a sequence of bytes not longer than X_PHC_C_MAX_NONSTD                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |          |                                                |          |               |             |                                        |            |                              |
+| Default value  | none                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |          |                                                |          |               |             |                                        |            |                              |
+| Description    | <p>The parameter specifies the non-standard reception capabilities of the local receiver. The maximum length for a non-CCITT capabilities message is 255 bytes. The minimum length is 5 bytes.</p> <table style="width: 100%; border: none;"> <tr><td style="width: 15%;">[byte 0]</td><td>Country code according to Recommendation T.35;</td></tr> <tr><td>[byte 1]</td><td>Country code;</td></tr> <tr><td>[byte 2, 3]</td><td>Manufacturer code (e.g. company 4711);</td></tr> <tr><td>[byte 4-n]</td><td>e.g. terminal type identity.</td></tr> </table> <p>The first two bytes define the country code and the next two bytes specify the terminal manufacturer code. The first byte of the country code is set according to Recommendation T.35; the second byte and bytes 3 to 4 of the manufacturer code are assigned nationally.</p> <p>Note that due to the effective bandwidth of the BAS (0.4 kbit/s or 50 bytes per second), the transmission time for a capability exchange including non-standard capabilities of maximum length may be more than 5 seconds.</p> | [byte 0] | Country code according to Recommendation T.35; | [byte 1] | Country code; | [byte 2, 3] | Manufacturer code (e.g. company 4711); | [byte 4-n] | e.g. terminal type identity. |
+| [byte 0]       | Country code according to Recommendation T.35;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |          |                                                |          |               |             |                                        |            |                              |
+| [byte 1]       | Country code;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |          |                                                |          |               |             |                                        |            |                              |
+| [byte 2, 3]    | Manufacturer code (e.g. company 4711);                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |          |                                                |          |               |             |                                        |            |                              |
+| [byte 4-n]     | e.g. terminal type identity.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |          |                                                |          |               |             |                                        |            |                              |
+
+**Table I.5-17/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
+|----------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_PHC_P_FALLBACK                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
+| Type of value  | unsigned long                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
+| Legal values   | PV_TRUE<br>PV_FALSE                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
+| Default value  | PV_TRUE                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
+| Description    | <p>The parameter specifies the fallback feature of the local terminal. The X_PHC_P_FALL_BACK parameter is a user optional service parameter of the Connect Request service element. It enables/disables the automatic retrial if the initial connection establishment with service "video phone" failed. In the retrial the service "phone" is used what usually allows to establish a connection to a <b>non</b> video phone terminal, e.g. an ordinary ISDN phone. If the retrial is successful, the audio mode G.711 unframed is indicated in the init-complete. If the retrial is not successful, the connect request fails and a negative connect confirmation is passed to the user.</p> <p>If X_PHC_P_FALL_BACK is set to PV_FALSE the automatic "phone" retrial is omitted and a connect request will fail if the "video phone" call is not accepted.</p> |
+
+###### I.5.7.2.3.2 Remote capability parameters
+
+**Table I.5-18/T.180**
+
+|                |                                                                                                                                                                                                                                                      |
+|----------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_PHC_P_RCAP_AUDIO                                                                                                                                                                                                                                   |
+| Type of value  | long                                                                                                                                                                                                                                                 |
+| Legal values   | X_PHC_PV_CAPNON<br>X_PHC_PV_AUDIO_711_A<br>X_PHC_PV_AUDIO_711_U<br>X_PHC_PV_AUDIO_722_64<br>X_PHC_PV_AUDIO_722_48<br>X_PHC_PV_AUDIO_16K<br>X_PHC_PV_AUDIO_ISO                                                                                        |
+| Default value  | none                                                                                                                                                                                                                                                 |
+| Description    | <p>The parameter specifies the audio reception capabilities of the remote receiver. The parameter values are described above; see parameter X_PHC_P_LCAP_AUDIO. The value X_PHC_PV_CAPNON indicates that no value is set by the remote terminal.</p> |
+
+**Table I.5-19/T.180**
+
+|                |                                                                                                                                                                                                                                               |
+|----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_PHC_P_RCAP_VIDEO                                                                                                                                                                                                                            |
+| Type of value  | long                                                                                                                                                                                                                                          |
+| Legal values   | X_PHC_PV_CAPNON<br>X_PHC_PV_VIDEO_QCIF<br>X_PHC_PV_VIDEO_CIF<br>X_PHC_PV_VIDEO_PINV1<br>X_PHC_PV_VIDEO_PINV2<br>X_PHC_PV_VIDEO_PINV3<br>X_PHC_PV_VIDEO_PINV4<br>X_PHC_PV_VIDEO_IMP<br>X_PHC_PV_VIDEO_ISO<br>X_PHC_PV_VIDEO_AVISO              |
+| Default value  | none                                                                                                                                                                                                                                          |
+| Description    | The parameter specifies the video reception capabilities of the remote receiver. The parameter values are described above; see parameter X_PHC_P_LCAP_VIDEO. The value X_PHC_PV_CAPNON indicates that no value is set by the remote terminal. |
+
+**Table I.5-20/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
+|----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_PHC_P_RCAP_DATA                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
+| Type of value  | long                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
+| Legal values   | X_PHC_PV_CAPNON<br><br>X_PHC_PV_DATA_VAR<br>X_PHC_PV_DATA_300                      X_PHC_PV_DATA_1200<br>X_PHC_PV_DATA_4800                    X_PHC_PV_DATA_6400<br>X_PHC_PV_DATA_8000                   X_PHC_PV_DATA_9600<br>X_PHC_PV_DATA_14400                  X_PHC_PV_DATA_16000<br>X_PHC_PV_DATA_24000                  X_PHC_PV_DATA_32000<br>X_PHC_PV_DATA_40000                  X_PHC_PV_DATA_48000<br>X_PHC_PV_DATA_56000                  X_PHC_PV_DATA_62400<br>X_PHC_PV_DATA_64000<br><br>X_PHC_PV_DATA_MLP4000    X_PHC_PV_DATA_MLP6400<br>X_PHC_PV_DATA_VARMLP |
+| Default value  | none                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
+| Description    | The parameter specifies the low-speed data reception capabilities of the remote receiver. The parameter values are described above; see parameter X_PHC_P_LCAP_DATA. The value X_PHC_PV_CAPNON indicates that no value is set by the remote terminal.                                                                                                                                                                                                                                                                                                                             |
+
+**Table I.5-21/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
+|----------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_PHC_P_RCAP_HDATA                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
+| Type of value  | long                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
+| Legal values   | X_PHC_PV_CAPNON<br>X_PHC_PV_HDATA_64                      X_PHC_PV_HDATA_128<br>X_PHC_PV_HDATA_192                  X_PHC_PV_HDATA_256<br>X_PHC_PV_HDATA_320                  X_PHC_PV_HDATA_384<br>X_PHC_PV_HDATA_512                  X_PHC_PV_HDATA_768<br>X_PHC_PV_HDATA_1152                X_PHC_PV_HDATA_1536<br>X_PHC_PV_HDATA_VAR<br>X_PHC_PV_HDATA_MLP62              X_PHC_PV_HDATA_MLP64<br>X_PHC_PV_HDATA_MLP128            X_PHC_PV_HDATA_MLP192<br>X_PHC_PV_HDATA_MLP256            X_PHC_PV_HDATA_MLP320<br>X_PHC_PV_HDATA_MLP384<br>X_PHC_PV_HDATA_VARMLP |
+| Default value  | none                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
+| Description    | The parameter specifies the high-speed data reception capabilities of the remote receiver. The parameter values are described above; see parameter X_PHC_P_LCAP_HDATA. The value X_PHC_PV_CAPNON indicates that no value is set by the remote terminal.                                                                                                                                                                                                                                                                                                                    |
+
+**Table I.5-22/T.180**
+
+|                |                                                                                                                                                                                                                                                        |
+|----------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_PHC_P_RCAP_TFRATE                                                                                                                                                                                                                                    |
+| Type of value  | long                                                                                                                                                                                                                                                   |
+| Legal values   | X_PHC_PV_CAPNON<br>X_PHC_PV_TFRATE_128<br>X_PHC_PV_TFRATE_192<br>X_PHC_PV_TFRATE_256<br>X_PHC_PV_TFRATE_512<br>X_PHC_PV_TFRATE_768<br>X_PHC_PV_TFRATE_1152<br>X_PHC_PV_TFRATE_1472                                                                     |
+| Default value  | none                                                                                                                                                                                                                                                   |
+| Description    | The parameter specifies the transfer rate reception capabilities of the remote receiver. The parameter values are described above; see parameter X_PHC_P_LCAP_TFRATE. The value X_PHC_PV_CAPNON indicates that no value is set by the remote terminal. |
+
+**Table I.5-23/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                           |
+|----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_PHC_P_RCAP_TFLINES                                                                                                                                                                                                                                                                                      |
+| Type of value  | long                                                                                                                                                                                                                                                                                                      |
+| Legal values   | X_PHC_PV_TFLINES_1B<br>X_PHC_PV_TFLINES_2B<br>X_PHC_PV_TFLINES_3B<br>X_PHC_PV_TFLINES_4B<br>X_PHC_PV_TFLINES_5B<br>X_PHC_PV_TFLINES_6B<br>X_PHC_PV_TFLINES_1H<br>X_PHC_PV_TFLINES_2H<br>X_PHC_PV_TFLINES_3H<br>X_PHC_PV_TFLINES_4H<br>X_PHC_PV_TFLINES_5H<br>X_PHC_PV_TFLINES_H11<br>X_PHC_PV_TFLINES_H12 |
+| Default value  | none                                                                                                                                                                                                                                                                                                      |
+| Description    | The parameter specifies the transfer line reception capabilities of the remote receiver. The parameter values are described above; see parameter X_PHC_P_LCAP_TFLINES.                                                                                                                                    |
+
+**Table I.5-24/T.180**
+
+|                |                                                                                                                                                                                                                                                      |
+|----------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_PHC_P_RCAP_MISC                                                                                                                                                                                                                                    |
+| Type of value  | long                                                                                                                                                                                                                                                 |
+| Legal values   | X_PHC_PV_CAPNON<br>X_PHC_PV_MISC_ENCR<br>X_PHC_PV_MISC_ESC<br>X_PHC_PV_MISC_MBE<br>X_PHC_PV_MISC_RESTRICT<br>X_PHC_PV_MISC_6BHCOMP                                                                                                                   |
+| Default value  | none                                                                                                                                                                                                                                                 |
+| Description    | The parameter specifies the miscellaneous reception capabilities of the remote receiver. The parameter values are described above; see parameter X_PHC_P_LCAP_MISC. The value X_PHC_PV_CAPNON indicates that no value is set by the remote terminal. |
+
+**Table I.5-25/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                      |
+|----------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_PHC_P_RCAP_DATAPPL                                                                                                                                                                                                                                                                                                                 |
+| Type of value  | long                                                                                                                                                                                                                                                                                                                                 |
+| Legal values   | X_PHC_PV_CAPNON<br>X_PHC_PV_APPL_STILLPIC_LSD<br>X_PHC_PV_APPL_STILLPIC_HSD<br>X_PHC_PV_APPL_STILLPIC_SPATIAL<br>X_PHC_PV_APPL_STILLPIC_PROG<br>X_PHC_PV_APPL_STILLPIC_ARITH<br>X_PHC_PV_APPL_STILLIMAGE<br>X_PHC_PV_APPL_CURSORDATA<br>X_PHC_PV_APPL_FAX3<br>X_PHC_PV_APPL_FAX4<br>X_PHC_PV_APPL_V120_LSD<br>X_PHC_PV_APPL_V120_HSD |
+| Default value  | none                                                                                                                                                                                                                                                                                                                                 |
+| Description    | The parameter specifies the reception application capabilities within LSD/HSD channels of the remote receiver. The parameter values are described above; see parameter X_PHC_P_LCAP_DATAPPL. The value X_PHC_PV_CAPNON indicates that no value is set by the remote terminal.                                                        |
+
+**Table I.5-26/T.180**
+
+|                |                                                                                                                                                                      |
+|----------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_PHC_P_RCAP_NONSTD                                                                                                                                                  |
+| Type of value  | unsigned char [ ], 5 ... 255 bytes                                                                                                                                   |
+| Legal values   | a sequence of bytes not longer than X_PHC_C_MAX_NONSTD                                                                                                               |
+| Default value  | none                                                                                                                                                                 |
+| Description    | The parameter specifies the non-standard reception capabilities of the remote receiver. The parameter values are described above; see parameter X_PHC_P_LCAP_NONSTD. |
+
+#### I.5.7.3 Services in the connected state
+
+The connected state of an audiovisual communication is entered with the reception of the init-complete (X\_PHC\_SP\_INIT\_COMPL) service primitive. There are four services available that can be used in the connected state to control the communication:
+
+- the Capability Exchange service to initiate a capability exchange with the remote terminal, e.g. to signal a different own capability set;
+- the Mode Switch service to change the currently used communication mode, e.g. to open or close a low speed data channel;
+- the Data Transfer service to send and receive data on a previously opened data channel;
+- the Control and Indication (C&I) service to send BAS commands to the remote terminal or receive BAS commands sent by the remote terminal.
+
+The capability exchange, the mode switch, and the C&I services all use the BAS for transmission. Therefore, requests from these services have to be scheduled so that the BAS is used by only one service at a time. The (effective) transfer rate available in the BAS is 0.4 kbit/s, which is equal to 50 bytes per second; thus the time needed for transmission of a command must not be neglected. The
+
+longest possible non-standard command, for example, comprises 256 bytes, and the transmission in the BAS would take a little bit more than five seconds. During this time the BAS is occupied and cannot be used to transmit another request.
+
+To avoid that the BAS is overrun, a flow control mechanism is used. After each request concerning the BAS, the application has to wait for the corresponding confirmation before the next BAS request is passed to the service provider. This does not only apply within a service but also between the three services using the BAS. If, for example, the application just requested a capability exchange, no mode switch request and no transmit C&I request may be passed to the service provider until the capability exchange confirmation is received. For each request concerning the BAS, the service provider checks whether there is an outstanding confirmation and will reject the request and generate an error indication with cause CC\_UNEXPECT if there is one.
+
+##### **I.5.7.3.1 Capability Exchange service**
+
+The Capability Exchange service is used to change one or more receive capabilities of the local terminal dynamically while the AV communication is active. The service elements capability exchange request and capability exchange confirmation are provided for this. They are defined as service primitives that are exchanged with the service provider through the XAPI function *x\_sndsp()* and *x\_rcvsp()*.
+
+###### **I.5.7.3.1.1 Service description**
+
+The **capability exchange request** primitive initiates a capability exchange sequence according to Recommendation H.242. It forces framing in both directions of transmission and the exchange of terminal capability codes with the peer entity. Either terminal may initiate the sequence, and there is no problem caused by both doing so simultaneously or nearly simultaneously. The terminal X which initiates the capability exchange first reinstates framing with the procedure defined in Recommendation H.242 and then transmits its current capability set. When the other terminal Y detects the incoming capability set, it begins transmission of its own set of capability codes. Note that the receiving terminal Y need not change its capability set in response to the new capability set of terminal X.
+
+The successful completion of the capability exchange sequence is indicated to the initiator with an **capability exchange confirmation** service primitive. It conveys two capability sets as output service parameters: the own capabilities (that have been included in the request) and the capabilities of the remote terminal. Both capability sets are complete, i.e. all parameters are present with one exception: the non-standard capability parameter is not present if no non-standard capabilities are specified locally or received from the remote terminal. Note that a capability parameter will take the value X\_PHC\_PV\_CAPNON if no such capability is present. The application should store the remote capabilities and observe them as limits to avoid failures in later mode switch requests.
+
+The capability exchange request requires the BAS for transmission and thus has to be coordinated with the other BAS requests (see I.5.7.3 above). No capability exchange request may be submitted while a capability exchange-, an add line-, a mode switch-, or a transfer C&I confirmation is outstanding.
+
+The capability exchange sequence is supervised by a timer (value about 10s). If the timer expires without multiframe alignment, an error indication is generated with cause code CC\_OTHER and diagnostic X\_PHC\_DC\_UNSYNC. If multiframe alignment could be achieved, but, even with retries, no complete capability set of the remote terminal was received within one timer period, an error indication with cause CC\_OTHER and diagnostic X\_PHC\_DC\_NOCAPSET is generated.
+
+The specification of the own, local capabilities parameters in the capability exchange request service primitive is optional. For each parameter not specified in the capability exchange request service primitive, the protocol machine adds the currently used value to the transmitted capability set. If the XAPI user wants to revoke a capability from the currently used set, it depends on the capability parameter which value has to be specified in the capability exchange request:
+
+- For a parameter that represents a group of capabilities and whose actual value is formed as the bit-wise OR combination of several defined values, X\_PHC\_PV\_CAPNON has to be specified to revoke all capabilities of this group. To revoke only some of the present capabilities, the new value is formed by switching off the bits corresponding to the capabilities to be revoked.
+
+Example: Assume that the variable *curr\_data\_cap* holds the current value of low-speed data capabilities and that this value is equal to X\_PHC\_PV\_DATA\_1200 | X\_PHC\_PV\_DATA\_9600 | X\_PHC\_PV\_DATA\_14400.
+
+To revoke the capability to receive LSD at 1200 bit/s, the value *curr\_data\_cap* & ~X\_PHC\_PV\_DATA\_1200 has to be specified for parameter X\_PHC\_P\_LCAP\_DATA in a capability exchange request.
+
+- For a parameter that takes exactly one value (and not the bit-wise OR combination of several defined values), the new value has to be specified to revoke or decrease capabilities.
+
+Example: To decrease the number of transfer lines supported from at most six B-channels to at most two B-channels, the value of the X\_PHC\_P\_LCAP\_TFLINES has to be changed from X\_PHC\_PV\_TFLINES\_6B to X\_PHC\_PV\_TFLINES\_2B in a capability exchange.
+
+- To revoke non-standard capabilities, the parameter X\_PHC\_LCAP\_NONSTD has to be specified in a capability exchange request without a value.
+
+**Hint:** There is a way to find out the currently active capability sets: a capability exchange request without any parameter will leave all local capabilities untouched and initiate a capability exchange with the currently used set. The capability exchange confirmation will yield the complete own and remote capability set.
+
+The service elements and their corresponding XAPI functions needed for Capability Exchange are described in Table I.5-27.
+
+**Table I.5-27/T.180 – Service elements and their corresponding XAPI functions for Capability Exchange**
+
+| Service element             | XAPI function | Service element identifier | Description                                                                                                                                                                                                                                                                                                    |
+|-----------------------------|---------------|----------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Capability Exchange Request | x_sndsp()     | X_PHC_SP_CAP_EXCHANGE_Q    | The Capability Exchange Request is passed to the provider to initiate a capability exchange sequence according to Recommendation H.242. The service element may be used by the active and the passive communication partner. The identifier of the corresponding service primitive is X_PHC_SP_CAP_EXCHANGE_Q. |
+
+**Table I.5-27/T.180 – Service elements and their corresponding XAPI functions  
+for Capability Exchange (*concluded*)**
+
+| Service element                  | XAPI function | Service element identifier | Description                                                                                                                                                                                                                                                                                                                 |
+|----------------------------------|---------------|----------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Capability Exchange Confirmation | x_revsp()     | X_PHC_SP_CAP_EXCHANGE_C    | The Capability Exchange Confirmation is passed to the initiator of the capability exchange request as acknowledgement of the command. The possibly changed local and remote capabilities are indicated to the user as service parameters. The identifier of the corresponding service primitive is X_PHC_SP_CAP_EXCHANGE_C. |
+
+###### I.5.7.3.1.2 Service parameters
+
+Table I.5-28 specifies the parameters of the Capability Exchange service.
+
+**Table I.5-28/T.180 – Parameters of the Capability Exchange service**
+
+| Parameter            | Capability Exchange service |              |
+|----------------------|-----------------------------|--------------|
+|                      | Request                     | Confirmation |
+| X_PHC_P_LCAP_AUDIO   | U                           | M            |
+| X_PHC_P_LCAP_VIDEO   | U                           | M            |
+| X_PHC_P_LCAP_DATA    | U                           | M            |
+| X_PHC_P_LCAP_HDATA   | U                           | M            |
+| X_PHC_P_LCAP_TFRATE  | U                           | M            |
+| X_PHC_P_LCAP_TFLINES | U                           | M            |
+| X_PHC_P_LCAP_MISC    | U                           | M            |
+| X_PHC_P_LCAP_DATAPPL | U                           | M            |
+| X_PHC_P_LCAP_NONSTD  | U                           | C            |
+| X_PHC_P_RCAP_AUDIO   |                             | M            |
+| X_PHC_P_RCAP_VIDEO   |                             | M            |
+| X_PHC_P_RCAP_DATA    |                             | M            |
+| X_PHC_P_RCAP_HDATA   |                             | M            |
+| X_PHC_P_RCAP_TFRATE  |                             | M            |
+| X_PHC_P_RCAP_TFLINES |                             | M            |
+| X_PHC_P_RCAP_MISC    |                             | M            |
+| X_PHC_P_RCAP_DATAPPL |                             | M            |
+| X_PHC_P_RCAP_NONSTD  |                             | C            |
+
+The definitions of the capability parameters can be found above in I.1.7.2, "Connection Establishment service".
+
+##### I.5.7.3.2 Mode Switch service
+
+The Mode Switch service enables the application program to dynamically switch the mode of an active AV communication or increase/decrease the number of connected channels in a multichannel connection. The service can be used at any time during a communication, after the mode initialization procedure has been completed, i.e. after an `X_PHC_SP_INIT_COMPL` has been received. The mode switching sequence as described in Recommendation H.242 is performed to change the used communication mode. Furthermore, the application is notified about mode switches which are initiated by the remote terminal.
+
+###### I.5.7.3.2.1 Service description
+
+There are service elements to increase or decrease the number of channels in a multichannel connection and there are service elements that initiate or indicate a change of the communication mode on the currently established channels.
+
+In an AV communication the two transmission directions are, in principle, independent. There may be symmetrical modes where the mode in receive direction is the same as in transmit direction and asymmetrical ones where the two modes differ. For a conversational application, a videophone for example, a symmetrical mode would be best, whereas to operate a remote supervision camera would require an asymmetrical communication mode.
+
+Thus, the communication mode as indicated to the application program distinguishes receive and transmission modes. For convenience, the global communication mode is split into several categories, e.g. video mode, audio mode, and data mode. For each category there is one service parameter giving the current receive mode and one for the transmit mode. The only exception is the number of established transfer lines (B-channels) because each channel provides a full-duplex connection that can be used in both directions simultaneously. There is only one parameter giving the number of currently connected lines.
+
+After successful completion of the mode initialization procedure on the Initial Channel (IC), Additional Channels (ACs) may be added to the AV connection with an **add line request** to increase the total bandwidth. Only the active AV terminal that initiated the establishment of the IC [the terminal which called `x_conreq()`], is allowed to establish additional channels. Up to five ACs may be added simultaneously with one add line request. The number of channels to be established and the addresses to be used are specified as service parameters. The **add line confirmation**, which is generated as acknowledgment to an add line request, indicates the number of successfully established new channels. A value of 0 indicates that no new channels could be established. A mode switch indication (see below) will follow when the new channels are synchronized to the initial channel and included in the AV communication. The parameter `X_PHC_P_MODE_TFLINES` then indicates the now available bandwidth (number of channels). As default the new channels are used to increase the video bandwidth. No add line request may be submitted while an add line confirmation or any other confirmation from a BAS request (capability exchange-, mode switch-, or transfer C&I confirmation) is outstanding. Altogether, inclusive of the initial channel, no more channels will be established than those indicated by the value of the `X_PHC_P_LCAP_TFLINES` parameter. An add line request with this maximum number of channels already reached will be answered immediately with an add line confirmation of 0 channels.
+
+The add line request may be used to establish additional B-channels in a multi-B-channel connection and to set up additional  $H_0$ -channels in a multi- $H_0$ -channel connection. Only channels of the same type may be combined in a multichannel connection.
+
+When establishing new channels, the service provider uses the addresses (phone numbers) in the same sequence as they are specified in the add line request. Each number is tried only once. The process stops when either the requested or maximum number of channels is reached or the specified
+
+numbers are exhausted. Then the add line confirmation is generated which indicates the number of successful established channels and the corresponding addresses. Unused addresses are ignored. In the case of basic rate interfaces ( $S_0$ ) one has to specify a number twice to set up two B-channels on the same interface. If an additional channel shall be established at the same interface as the initial channel, the number used in the *x\_conreq()* has to be specified in the add line request too.
+
+On the passive side, the service provider automatically accepts incoming calls for additional channels, as long as the maximum number of channels defined in X\_PHC\_P\_LCAP\_TFLINES is not yet reached. When the new channel is successfully synchronized with the initial channel, the passive application is informed about the new number of channels with a mode switch indication. As on the active side, the parameter X\_PHC\_P\_MODE\_TFLINES indicates the now available number of channels. Note that only the terminal that initiated establishment of the initial channel is allowed to establish additional channels. The service provider will generate an error indication with cause code CC\_UNEXPECT if an add line request is submitted on the passive side of an AV connection.
+
+With a **hang-up line request**, previously established additional channels may be disconnected again. A parameter specifies the number of channels to be closed. The hang-up line request implies a mode switch request that decreases the used transfer rate so that the specified number of channels becomes idle. These idle channels are then disconnected. Note that only additional channels may be closed with a hang-up line request; the initial channel has to be disconnected with *x\_relreq()* or *x\_snddis()*. As response to a hang-up line request, the application gets a mode switch indication in which the value of X\_PHC\_P\_MODE\_TFLINES is decremented by the number of closed channels. The hang-up line request may be used by either the active terminal or the passive terminal. If used on the passive side, it is advisable to decrease the value of X\_PHC\_P\_LCAP\_TFLINES accordingly in a following capability exchange, to prevent the active terminal from re-establishing the closed additional channels.
+
+The **mode switch request** can be used by either terminal at any time after successful mode initialization (reception of X\_PHC\_SP\_INIT\_COMPL) to dynamically change the mode in an active AV communication. The mode switching sequence according to Recommendation H.242 is followed. If a mode switch is requested while the Codec is receiving or transmitting unframed, the appropriate frame reinstatement procedure is executed automatically prior to the mode switch to enforce a framed mode. The service provider generates a **mode switch confirmation** as response to a previous mode switch request. The new communication mode is indicated by the service parameters. The mode switch request requires the BAS for transmission and thus has to be coordinated with the other BAS requests (see I.5.7.3 above). No mode switch request may be submitted while a mode switch-, an add line-, a capability exchange-, or a transfer C&I confirmation is outstanding.
+
+A mode switch request will fail:
+
+- if one of the specified parameters has an invalid value. The service provider will generate an error indication with cause CC\_BADVALUE in this case;
+- if an inconsistent combination of audio, video, and data is specified, the service provider will generate an error indication with cause CC\_OTHER and diagnostic X\_PHC\_DC\_BADCOMBI in this case;
+- if the requested mode is in conflict with the known receive and decode capabilities of the remote terminal. The service provider will generate an error indication with cause CC\_OTHER and diagnostic X\_PHC\_DC\_CAPCONFLICT in this case.
+
+If a mode switch request fails, the current communication mode is retained.
+
+The **mode switch indication** is generated by the service provider to inform the application about a mode switch initiated by the remote partner or an automatic mode switch triggered by a local condition. Usually no action is required on this indication.
+
+Some notes to communication mode switching:
+
+NOTE 1 – An AV terminal always has to switch its receiver/decoder according to the BAS commands received from the other end terminal, which itself has to transmit data as specified by the previously sent BAS commands. This, of course, applies for both directions. If the own transmitting mode is changed, the remote terminal has to change its receive mode accordingly. Conversely, if the remote terminal initiates a mode switch, the service provider automatically switches the local receiver to the new mode and indicates the mode switch to the application. No action is required on this indication.
+
+NOTE 2 – The own transmitting mode may be changed only according to the known receive and decode capabilities of the remote terminal. The service provider checks whether the new mode specified in a mode switch request is within the known capabilities of the remote terminal. The current mode will not be changed, if the specified new mode is in conflict with the remote capabilities for one category, even if the values specified in other categories are supported by the remote terminal. In this case, the mode switch confirmation generated as response to the mode switch request, will indicate an unchanged communication mode.
+
+NOTE 3 – The service provider will automatically initiate a mode switch if the remote terminal changes its capabilities so that the current mode is no longer receivable/decodable. The new transmission mode is selected by the service provider in accordance with the new capability set of the remote terminal. The new mode is indicated to the application. No action is required on this indication.
+
+NOTE 4 – It is not possible to request a change of the own receive/decoding mode because it always has to correspond to the transmission/encoding mode of the remote terminal. (See also Note 1.) However, there is an indirect way to control the own receiver: A new, different capability set is indicated to the remote terminal with a capability exchange request. If the current reception mode is then no longer allowed with the new capability set, the remote terminal has to switch to another transmission mode and the own receiver has to follow this. But this only works if the own capability set is decreased. If the capability set is increased, i.e. previously unsupported capabilities are signalled, the remote terminal is not enforced to take advantage of the new capabilities and change its transmission mode. The currently used transmission mode may be kept as long as it corresponds to the receiving capabilities of the other side.
+
+NOTE 5 – If the video bandwidth would become zero as the result of a mode switch request, the service provider automatically sends a video command "Freeze picture Request" (VCF) to the remote terminal before the mode switch is executed. The VCF will freeze the picture at the remote terminal until a picture release signal is sent or a time-out period of at least six seconds has expired. The VCF is not automatically repeated by the service provider. If the application wishes to continue the freezing of the picture, it should send VCF repeatedly with an appropriate period.
+
+The service elements and their corresponding XAPI functions needed for Mode Switch are described in Table I.5-29.
+
+**Table I.5-29/T.180 – Service elements and their corresponding XAPI functions  
+for Mode Switch**
+
+| Service element       | XAPI function | Service element identifier | Description                                                                                                                                                                                                                                                                                                                                                |
+|-----------------------|---------------|----------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Add Line Request      | x_sndsp()     | X_PHC_SP_ADD_LINE_Q        | <p>The Add Line Request primitive is passed to the provider to establish additional channels for a multi channel connection and include the new channels in the AV communication. The number of ACs to be established and the addresses to be used are specified as parameters.</p> <p>X_PHC_SP_ADD_LINE_Q is the identifier of the service primitive.</p> |
+| Add Line Confirmation | x_rcvsp()     | X_PHC_SP_ADD_LINE_C        | <p>The Add Line Confirmation is passed to the application as a response to a previous add line request. The number of established new channels and the corresponding phone numbers are indicated to the application as output service parameters.</p> <p>X_PHC_SP_ADD_LINE_C is the identifier of the service primitive.</p>                               |
+| Hang-up Line Request  | x_sndsp()     | X_PHC_SP_HUP_LINE_Q        | <p>The Hang-up Line Request may be submitted to close some or all of the additional channels. The initial channel is not affected.</p> <p>X_PHC_SP_HUP_LINE_Q is the identifier of the service primitive.</p>                                                                                                                                              |
+| Mode Switch Request   | x_sndsp()     | X_PHC_SP_MODE_SWITCH_Q     | <p>The Mode Switch Request primitive is passed to the provider to initiate a change of the current transmission mode. The new mode is defined by the service parameters. Only categories to be changed must be specified. All others keep their values.</p> <p>X_PHC_SP_MODE_SWITCH_Q is the identifier of the service primitive.</p>                      |
+
+**Table I.5-29/T.180 – Service elements and their corresponding XAPI functions  
+for Mode Switch (concluded)**
+
+| Service element          | XAPI function | Service element identifier | Description                                                                                                                                                                                                                                                                                                                                                                                       |
+|--------------------------|---------------|----------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Mode Switch Confirmation | x_rcvsp()     | X_PHC_SP_MODE_SWITCH_C     | <p>The Mode Switch Confirmation is passed to the application as a response to a previous mode switch request. The service parameters indicate the current receive and transmit mode. If mode switching succeeded, the transmit mode is equal to the one specified in the request.</p> <p>X_PHC_SP_MODE_SWITCH_C is the identifier of the service primitive.</p>                                   |
+| Mode Switch Indication   | x_rcvsp()     | X_PHC_SP_MODE_SWITCH_I     | <p>The Mode Switch Indication is passed to the application when the communication mode was changed by the provider without request from the application. See Notes above for the situations where such automatically mode changes are necessary. The service parameters indicate the new receive and transmit mode.</p> <p>X_PHC_SP_MODE_SWITCH_I is the identifier of the service primitive.</p> |
+
+NOTE 6 – The current communication mode is indicated to the application with:
+
+- 1) the X\_PHC\_SP\_INIT\_COMPL primitive;
+- 2) the X\_PHC\_SP\_MODE\_SWITCH\_C; and
+- 3) the X\_PHC\_SP\_MODE\_SWITCH\_I.
+
+The application may save this mode information internally, if it is required to know the current mode at any time. If the application hasn't done so, or the saved mode information has unfortunately been lost, there is a simple way to retrieve the current communication mode from the service provider: a mode switch request with no parameters will leave the current communication mode unchanged and will be answered immediately by the provider with a mode switch confirmation that indicates the current mode within the service parameters.
+
+###### I.5.7.3.2.2 Service parameters
+
+Table I.5-30 specifies the parameters of the Mode Switch service.
+
+**Table I.5-30/T.180 – Parameters of the Mode Switch service**
+
+| Parameter            | Mode Switch service element |                        |                          |
+|----------------------|-----------------------------|------------------------|--------------------------|
+|                      | Mode Switch Request         | Mode Switch Indication | Mode Switch Confirmation |
+| X_PHC_P_RMOD_AUDIO   |                             | M                      | M                        |
+| X_PHC_P_RMOD_VIDEO   |                             | M                      | M                        |
+| X_PHC_P_RMOD_DATA    |                             | M                      | M                        |
+| X_PHC_P_RMOD_HDATA   |                             | M                      | M                        |
+| X_PHC_P_RMOD_TFRATE  |                             | M                      | M                        |
+| X_PHC_P_RMOD_SYNC    |                             | M                      | M                        |
+| X_PHC_P_RMOD_DATAPPL |                             | M                      | M                        |
+| X_PHC_P_RMOD_MISC    |                             | M                      | M                        |
+| X_PHC_P_TMOD_AUDIO   | U                           | M                      | M                        |
+| X_PHC_P_TMOD_VIDEO   | U                           | M                      | M                        |
+| X_PHC_P_TMOD_DATA    | U                           | M                      | M                        |
+| X_PHC_P_TMOD_HDATA   | U                           | M                      | M                        |
+| X_PHC_P_TMOD_TFRATE  | U                           | M                      | M                        |
+| X_PHC_P_TMOD_SYNC    |                             | M                      | M                        |
+| X_PHC_P_TMOD_DATAPPL | U                           | M                      | M                        |
+| X_PHC_P_TMOD_MISC    | U                           | M                      | M                        |
+| X_PHC_P_MODE_TFLINES | U                           | M                      | M                        |
+| X_PHC_P_NUM_LINES    | M                           | M                      | M                        |
+| A_OUTBAND_ADR        | M                           | C                      |                          |
+
+###### I.5.7.3.2.3 Receive mode parameters
+
+Tables I.5-31 to I.5-49 describe the parameters for the Mode Switch service.
+
+**Table I.5-31/T.180**
+
+|                           |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |                     |                                                  |                     |                                      |                       |                                              |                           |                                                      |                       |                                                   |                       |                                                           |                       |                                                      |                       |                                                      |                       |                                                      |                      |                                                                                      |                       |                                                                                 |                       |                                                                                |                       |                                                                                |                       |                                                                                  |                    |                           |
+|---------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------|--------------------------------------------------|---------------------|--------------------------------------|-----------------------|----------------------------------------------|---------------------------|------------------------------------------------------|-----------------------|---------------------------------------------------|-----------------------|-----------------------------------------------------------|-----------------------|------------------------------------------------------|-----------------------|------------------------------------------------------|-----------------------|------------------------------------------------------|----------------------|--------------------------------------------------------------------------------------|-----------------------|---------------------------------------------------------------------------------|-----------------------|--------------------------------------------------------------------------------|-----------------------|--------------------------------------------------------------------------------|-----------------------|----------------------------------------------------------------------------------|--------------------|---------------------------|
+| Parameter name            | X_PHC_P_RMOD_AUDIO                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |                     |                                                  |                     |                                      |                       |                                              |                           |                                                      |                       |                                                   |                       |                                                           |                       |                                                      |                       |                                                      |                       |                                                      |                      |                                                                                      |                       |                                                                                 |                       |                                                                                |                       |                                                                                |                       |                                                                                  |                    |                           |
+| Type of value             | long                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |                     |                                                  |                     |                                      |                       |                                              |                           |                                                      |                       |                                                   |                       |                                                           |                       |                                                      |                       |                                                      |                       |                                                      |                      |                                                                                      |                       |                                                                                 |                       |                                                                                |                       |                                                                                |                       |                                                                                  |                    |                           |
+| Legal values              | X_PHC_PV_MDAU_OFF_U<br>X_PHC_PV_MDAU_OFF_F<br>X_PHC_PV_MDAU_G711A_U<br>X_PHC_PV_MDAU_G711A_F<br>X_PHC_PV_MDAU_G711U_U<br>X_PHC_PV_MDAU_G711U_F<br>X_PHC_PV_MDAU_G722_M1<br>X_PHC_PV_MDAU_G722_M2<br>X_PHC_PV_MDAU_G722_M3<br>X_PHC_PV_MDAU_ISO_64<br>X_PHC_PV_MDAU_ISO_128<br>X_PHC_PV_MDAU_ISO_192<br>X_PHC_PV_MDAU_ISO_256<br>X_PHC_PV_MDAU_ISO_384<br>X_PHC_PV_MDAU_G728                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |                     |                                                  |                     |                                      |                       |                                              |                           |                                                      |                       |                                                   |                       |                                                           |                       |                                                      |                       |                                                      |                       |                                                      |                      |                                                                                      |                       |                                                                                 |                       |                                                                                |                       |                                                                                |                       |                                                                                  |                    |                           |
+| Default value             | none                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |                     |                                                  |                     |                                      |                       |                                              |                           |                                                      |                       |                                                   |                       |                                                           |                       |                                                      |                       |                                                      |                       |                                                      |                      |                                                                                      |                       |                                                                                 |                       |                                                                                |                       |                                                                                |                       |                                                                                  |                    |                           |
+| Description               | <p>This parameter is returned by the service provider in mode switch indications and confirmations. It indicates the current audio receive mode.</p> <table> <tr> <td>X_PHC_PV_MDAU_OFF_U</td> <td>No audio signal and no framing in the I-channel;</td> </tr> <tr> <td>X_PHC_PV_MDAU_OFF_F</td> <td>No audio signal, FAS and BAS in use;</td> </tr> <tr> <td>X_PHC_PV_MDAU_G711A_U</td> <td>G.711 audio at 64 kbit/s, A-law, no framing;</td> </tr> <tr> <td>X_PHC_PV_MDAU_G711A_F and</td> <td>G.711 audio at 56 kbit/s, A-law, FAS and BAS in use;</td> </tr> <tr> <td>X_PHC_PV_MDAU_G711U_U</td> <td>G.711 audio at 64 kbit/s, <math>\mu</math>-law, no framing;</td> </tr> <tr> <td>X_PHC_PV_MDAU_G711U_F</td> <td>G.711 audio at 56 kbit/s, <math>\mu</math>-law, FAS and BAS in use;</td> </tr> <tr> <td>X_PHC_PV_MDAU_G722_M1</td> <td>G.722 7 kHz audio at 64 kbit/s, no framing (mode 1);</td> </tr> <tr> <td>X_PHC_PV_MDAU_G722_M2</td> <td>G.722 7 kHz audio at 56 kbit/s, no framing (mode 2);</td> </tr> <tr> <td>X_PHC_PV_MDAU_G722_M3</td> <td>G.722 7 kHz audio at 48 kbit/s, no framing (mode 3);</td> </tr> <tr> <td>X_PHC_PV_MDAU_ISO_64</td> <td>ISO standard audio at 64 kbit/s in time-slot 2 (TS2) of an <math>H_0</math> or greater channel;</td> </tr> <tr> <td>X_PHC_PV_MDAU_ISO_128</td> <td>ISO standard audio at 128 kbit/s in TS2 and TS3 of an <math>H_0</math> or greater channel;</td> </tr> <tr> <td>X_PHC_PV_MDAU_ISO_192</td> <td>ISO standard audio at 192 kbit/s in TS2 to TS4 of an <math>H_0</math> or greater channel;</td> </tr> <tr> <td>X_PHC_PV_MDAU_ISO_256</td> <td>ISO standard audio at 256 kbit/s in TS2 to TS5 of an <math>H_0</math> or greater channel;</td> </tr> <tr> <td>X_PHC_PV_MDAU_ISO_384</td> <td>ISO standard audio at 384 kbit/s in TS2 to TS7 of a channel greater than <math>H_0</math>;</td> </tr> <tr> <td>X_PHC_PV_MDAU_G728</td> <td>G.728 audio at 16 kbit/s.</td> </tr> </table> | X_PHC_PV_MDAU_OFF_U | No audio signal and no framing in the I-channel; | X_PHC_PV_MDAU_OFF_F | No audio signal, FAS and BAS in use; | X_PHC_PV_MDAU_G711A_U | G.711 audio at 64 kbit/s, A-law, no framing; | X_PHC_PV_MDAU_G711A_F and | G.711 audio at 56 kbit/s, A-law, FAS and BAS in use; | X_PHC_PV_MDAU_G711U_U | G.711 audio at 64 kbit/s, $\mu$ -law, no framing; | X_PHC_PV_MDAU_G711U_F | G.711 audio at 56 kbit/s, $\mu$ -law, FAS and BAS in use; | X_PHC_PV_MDAU_G722_M1 | G.722 7 kHz audio at 64 kbit/s, no framing (mode 1); | X_PHC_PV_MDAU_G722_M2 | G.722 7 kHz audio at 56 kbit/s, no framing (mode 2); | X_PHC_PV_MDAU_G722_M3 | G.722 7 kHz audio at 48 kbit/s, no framing (mode 3); | X_PHC_PV_MDAU_ISO_64 | ISO standard audio at 64 kbit/s in time-slot 2 (TS2) of an $H_0$ or greater channel; | X_PHC_PV_MDAU_ISO_128 | ISO standard audio at 128 kbit/s in TS2 and TS3 of an $H_0$ or greater channel; | X_PHC_PV_MDAU_ISO_192 | ISO standard audio at 192 kbit/s in TS2 to TS4 of an $H_0$ or greater channel; | X_PHC_PV_MDAU_ISO_256 | ISO standard audio at 256 kbit/s in TS2 to TS5 of an $H_0$ or greater channel; | X_PHC_PV_MDAU_ISO_384 | ISO standard audio at 384 kbit/s in TS2 to TS7 of a channel greater than $H_0$ ; | X_PHC_PV_MDAU_G728 | G.728 audio at 16 kbit/s. |
+| X_PHC_PV_MDAU_OFF_U       | No audio signal and no framing in the I-channel;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |                     |                                                  |                     |                                      |                       |                                              |                           |                                                      |                       |                                                   |                       |                                                           |                       |                                                      |                       |                                                      |                       |                                                      |                      |                                                                                      |                       |                                                                                 |                       |                                                                                |                       |                                                                                |                       |                                                                                  |                    |                           |
+| X_PHC_PV_MDAU_OFF_F       | No audio signal, FAS and BAS in use;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |                     |                                                  |                     |                                      |                       |                                              |                           |                                                      |                       |                                                   |                       |                                                           |                       |                                                      |                       |                                                      |                       |                                                      |                      |                                                                                      |                       |                                                                                 |                       |                                                                                |                       |                                                                                |                       |                                                                                  |                    |                           |
+| X_PHC_PV_MDAU_G711A_U     | G.711 audio at 64 kbit/s, A-law, no framing;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |                     |                                                  |                     |                                      |                       |                                              |                           |                                                      |                       |                                                   |                       |                                                           |                       |                                                      |                       |                                                      |                       |                                                      |                      |                                                                                      |                       |                                                                                 |                       |                                                                                |                       |                                                                                |                       |                                                                                  |                    |                           |
+| X_PHC_PV_MDAU_G711A_F and | G.711 audio at 56 kbit/s, A-law, FAS and BAS in use;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |                     |                                                  |                     |                                      |                       |                                              |                           |                                                      |                       |                                                   |                       |                                                           |                       |                                                      |                       |                                                      |                       |                                                      |                      |                                                                                      |                       |                                                                                 |                       |                                                                                |                       |                                                                                |                       |                                                                                  |                    |                           |
+| X_PHC_PV_MDAU_G711U_U     | G.711 audio at 64 kbit/s, $\mu$ -law, no framing;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |                     |                                                  |                     |                                      |                       |                                              |                           |                                                      |                       |                                                   |                       |                                                           |                       |                                                      |                       |                                                      |                       |                                                      |                      |                                                                                      |                       |                                                                                 |                       |                                                                                |                       |                                                                                |                       |                                                                                  |                    |                           |
+| X_PHC_PV_MDAU_G711U_F     | G.711 audio at 56 kbit/s, $\mu$ -law, FAS and BAS in use;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |                     |                                                  |                     |                                      |                       |                                              |                           |                                                      |                       |                                                   |                       |                                                           |                       |                                                      |                       |                                                      |                       |                                                      |                      |                                                                                      |                       |                                                                                 |                       |                                                                                |                       |                                                                                |                       |                                                                                  |                    |                           |
+| X_PHC_PV_MDAU_G722_M1     | G.722 7 kHz audio at 64 kbit/s, no framing (mode 1);                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |                     |                                                  |                     |                                      |                       |                                              |                           |                                                      |                       |                                                   |                       |                                                           |                       |                                                      |                       |                                                      |                       |                                                      |                      |                                                                                      |                       |                                                                                 |                       |                                                                                |                       |                                                                                |                       |                                                                                  |                    |                           |
+| X_PHC_PV_MDAU_G722_M2     | G.722 7 kHz audio at 56 kbit/s, no framing (mode 2);                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |                     |                                                  |                     |                                      |                       |                                              |                           |                                                      |                       |                                                   |                       |                                                           |                       |                                                      |                       |                                                      |                       |                                                      |                      |                                                                                      |                       |                                                                                 |                       |                                                                                |                       |                                                                                |                       |                                                                                  |                    |                           |
+| X_PHC_PV_MDAU_G722_M3     | G.722 7 kHz audio at 48 kbit/s, no framing (mode 3);                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |                     |                                                  |                     |                                      |                       |                                              |                           |                                                      |                       |                                                   |                       |                                                           |                       |                                                      |                       |                                                      |                       |                                                      |                      |                                                                                      |                       |                                                                                 |                       |                                                                                |                       |                                                                                |                       |                                                                                  |                    |                           |
+| X_PHC_PV_MDAU_ISO_64      | ISO standard audio at 64 kbit/s in time-slot 2 (TS2) of an $H_0$ or greater channel;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |                     |                                                  |                     |                                      |                       |                                              |                           |                                                      |                       |                                                   |                       |                                                           |                       |                                                      |                       |                                                      |                       |                                                      |                      |                                                                                      |                       |                                                                                 |                       |                                                                                |                       |                                                                                |                       |                                                                                  |                    |                           |
+| X_PHC_PV_MDAU_ISO_128     | ISO standard audio at 128 kbit/s in TS2 and TS3 of an $H_0$ or greater channel;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |                     |                                                  |                     |                                      |                       |                                              |                           |                                                      |                       |                                                   |                       |                                                           |                       |                                                      |                       |                                                      |                       |                                                      |                      |                                                                                      |                       |                                                                                 |                       |                                                                                |                       |                                                                                |                       |                                                                                  |                    |                           |
+| X_PHC_PV_MDAU_ISO_192     | ISO standard audio at 192 kbit/s in TS2 to TS4 of an $H_0$ or greater channel;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |                     |                                                  |                     |                                      |                       |                                              |                           |                                                      |                       |                                                   |                       |                                                           |                       |                                                      |                       |                                                      |                       |                                                      |                      |                                                                                      |                       |                                                                                 |                       |                                                                                |                       |                                                                                |                       |                                                                                  |                    |                           |
+| X_PHC_PV_MDAU_ISO_256     | ISO standard audio at 256 kbit/s in TS2 to TS5 of an $H_0$ or greater channel;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |                     |                                                  |                     |                                      |                       |                                              |                           |                                                      |                       |                                                   |                       |                                                           |                       |                                                      |                       |                                                      |                       |                                                      |                      |                                                                                      |                       |                                                                                 |                       |                                                                                |                       |                                                                                |                       |                                                                                  |                    |                           |
+| X_PHC_PV_MDAU_ISO_384     | ISO standard audio at 384 kbit/s in TS2 to TS7 of a channel greater than $H_0$ ;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |                     |                                                  |                     |                                      |                       |                                              |                           |                                                      |                       |                                                   |                       |                                                           |                       |                                                      |                       |                                                      |                       |                                                      |                      |                                                                                      |                       |                                                                                 |                       |                                                                                |                       |                                                                                |                       |                                                                                  |                    |                           |
+| X_PHC_PV_MDAU_G728        | G.728 audio at 16 kbit/s.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |                     |                                                  |                     |                                      |                       |                                              |                           |                                                      |                       |                                                   |                       |                                                           |                       |                                                      |                       |                                                      |                       |                                                      |                      |                                                                                      |                       |                                                                                 |                       |                                                                                |                       |                                                                                |                       |                                                                                  |                    |                           |
+
+**Table I.5-32/T.180**
+
+|                             |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |                   |                     |                     |  |                    |                                                           |  |                                                           |                   |                                                                                                             |                     |                                                                                      |                             |  |                     |                                |                     |                                |                     |                                |                     |                                |
+|-----------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------|---------------------|---------------------|--|--------------------|-----------------------------------------------------------|--|-----------------------------------------------------------|-------------------|-------------------------------------------------------------------------------------------------------------|---------------------|--------------------------------------------------------------------------------------|-----------------------------|--|---------------------|--------------------------------|---------------------|--------------------------------|---------------------|--------------------------------|---------------------|--------------------------------|
+| Parameter name              | X_PHC_P_RMOD_VIDEO                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |                   |                     |                     |  |                    |                                                           |  |                                                           |                   |                                                                                                             |                     |                                                                                      |                             |  |                     |                                |                     |                                |                     |                                |                     |                                |
+| Type of value               | long                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |                   |                     |                     |  |                    |                                                           |  |                                                           |                   |                                                                                                             |                     |                                                                                      |                             |  |                     |                                |                     |                                |                     |                                |                     |                                |
+| Legal values                | X_PHC_PV_MDVI_OFF<br>X_PHC_PV_MDVI_H261<br>X_PHC_PV_MDVI_ISO<br>X_PHC_PV_MDVI_AVISO<br>X_PHC_PV_MDVI_PINV1<br>X_PHC_PV_MDVI_PINV2<br>X_PHC_PV_MDVI_PINV3<br>X_PHC_PV_MDVI_PINV4                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |                   |                     |                     |  |                    |                                                           |  |                                                           |                   |                                                                                                             |                     |                                                                                      |                             |  |                     |                                |                     |                                |                     |                                |                     |                                |
+| Default value               | none                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |                   |                     |                     |  |                    |                                                           |  |                                                           |                   |                                                                                                             |                     |                                                                                      |                             |  |                     |                                |                     |                                |                     |                                |                     |                                |
+| Description                 | <p>This parameter is returned by the service provider in mode switch indications and confirmations. It indicates the current video receive mode.</p> <p>A legal value of the video mode parameter is either X_PHC_PV_MDVI_OFF or a combination of one video coding value, one video picture format value, and one video frame rate value. The bit-wise OR operator is used to combine the three values.</p> <table> <tr> <td>X_PHC_PV_MDVI_OFF</td> <td>Video switched off;</td> </tr> <tr> <td colspan="2"><b>Video coding</b></td> </tr> <tr> <td>X_PHC_PV_MDVI_H261</td> <td>Video is on, coding is according to Recommendation H.261.</td> </tr> <tr> <td></td> <td>Video data occupies all capacity not otherwise allocated;</td> </tr> <tr> <td>X_PHC_PV_MDVI_ISO</td> <td>Video is on, coding is according to ISO standard. Video data occupies all capacity not otherwise allocated;</td> </tr> <tr> <td>X_PHC_PV_MDVI_AVISO</td> <td>ISO standard composite audio/video data occupy all capacity not otherwise allocated.</td> </tr> <tr> <td colspan="2"><br/><b>Video frame rate</b></td> </tr> <tr> <td>X_PHC_PV_MDVI_PINV1</td> <td>Picture Interval is 1/29.75 s;</td> </tr> <tr> <td>X_PHC_PV_MDVI_PINV2</td> <td>Picture Interval is 2/29.75 s;</td> </tr> <tr> <td>X_PHC_PV_MDVI_PINV3</td> <td>Picture Interval is 3/29.75 s;</td> </tr> <tr> <td>X_PHC_PV_MDVI_PINV4</td> <td>Picture Interval is 4/29.75 s.</td> </tr> </table> | X_PHC_PV_MDVI_OFF | Video switched off; | <b>Video coding</b> |  | X_PHC_PV_MDVI_H261 | Video is on, coding is according to Recommendation H.261. |  | Video data occupies all capacity not otherwise allocated; | X_PHC_PV_MDVI_ISO | Video is on, coding is according to ISO standard. Video data occupies all capacity not otherwise allocated; | X_PHC_PV_MDVI_AVISO | ISO standard composite audio/video data occupy all capacity not otherwise allocated. | <br><b>Video frame rate</b> |  | X_PHC_PV_MDVI_PINV1 | Picture Interval is 1/29.75 s; | X_PHC_PV_MDVI_PINV2 | Picture Interval is 2/29.75 s; | X_PHC_PV_MDVI_PINV3 | Picture Interval is 3/29.75 s; | X_PHC_PV_MDVI_PINV4 | Picture Interval is 4/29.75 s. |
+| X_PHC_PV_MDVI_OFF           | Video switched off;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |                   |                     |                     |  |                    |                                                           |  |                                                           |                   |                                                                                                             |                     |                                                                                      |                             |  |                     |                                |                     |                                |                     |                                |                     |                                |
+| <b>Video coding</b>         |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |                   |                     |                     |  |                    |                                                           |  |                                                           |                   |                                                                                                             |                     |                                                                                      |                             |  |                     |                                |                     |                                |                     |                                |                     |                                |
+| X_PHC_PV_MDVI_H261          | Video is on, coding is according to Recommendation H.261.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |                   |                     |                     |  |                    |                                                           |  |                                                           |                   |                                                                                                             |                     |                                                                                      |                             |  |                     |                                |                     |                                |                     |                                |                     |                                |
+|                             | Video data occupies all capacity not otherwise allocated;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |                   |                     |                     |  |                    |                                                           |  |                                                           |                   |                                                                                                             |                     |                                                                                      |                             |  |                     |                                |                     |                                |                     |                                |                     |                                |
+| X_PHC_PV_MDVI_ISO           | Video is on, coding is according to ISO standard. Video data occupies all capacity not otherwise allocated;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |                   |                     |                     |  |                    |                                                           |  |                                                           |                   |                                                                                                             |                     |                                                                                      |                             |  |                     |                                |                     |                                |                     |                                |                     |                                |
+| X_PHC_PV_MDVI_AVISO         | ISO standard composite audio/video data occupy all capacity not otherwise allocated.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |                   |                     |                     |  |                    |                                                           |  |                                                           |                   |                                                                                                             |                     |                                                                                      |                             |  |                     |                                |                     |                                |                     |                                |                     |                                |
+| <br><b>Video frame rate</b> |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |                   |                     |                     |  |                    |                                                           |  |                                                           |                   |                                                                                                             |                     |                                                                                      |                             |  |                     |                                |                     |                                |                     |                                |                     |                                |
+| X_PHC_PV_MDVI_PINV1         | Picture Interval is 1/29.75 s;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |                   |                     |                     |  |                    |                                                           |  |                                                           |                   |                                                                                                             |                     |                                                                                      |                             |  |                     |                                |                     |                                |                     |                                |                     |                                |
+| X_PHC_PV_MDVI_PINV2         | Picture Interval is 2/29.75 s;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |                   |                     |                     |  |                    |                                                           |  |                                                           |                   |                                                                                                             |                     |                                                                                      |                             |  |                     |                                |                     |                                |                     |                                |                     |                                |
+| X_PHC_PV_MDVI_PINV3         | Picture Interval is 3/29.75 s;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |                   |                     |                     |  |                    |                                                           |  |                                                           |                   |                                                                                                             |                     |                                                                                      |                             |  |                     |                                |                     |                                |                     |                                |                     |                                |
+| X_PHC_PV_MDVI_PINV4         | Picture Interval is 4/29.75 s.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |                   |                     |                     |  |                    |                                                           |  |                                                           |                   |                                                                                                             |                     |                                                                                      |                             |  |                     |                                |                     |                                |                     |                                |                     |                                |
+
+**Table I.5-33/T.180**
+
+|                       |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |  |                      |                   |                      |                                                           |                       |                                                            |                       |                                                            |                       |                                                            |                       |                                              |                       |                                                                        |
+|-----------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--|----------------------|-------------------|----------------------|-----------------------------------------------------------|-----------------------|------------------------------------------------------------|-----------------------|------------------------------------------------------------|-----------------------|------------------------------------------------------------|-----------------------|----------------------------------------------|-----------------------|------------------------------------------------------------------------|
+| Parameter name        | X_PHC_P_RMOD_DATA                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |  |                      |                   |                      |                                                           |                       |                                                            |                       |                                                            |                       |                                                            |                       |                                              |                       |                                                                        |
+| Type of value         | long                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |  |                      |                   |                      |                                                           |                       |                                                            |                       |                                                            |                       |                                                            |                       |                                              |                       |                                                                        |
+| Legal values          | X_PHC_PV_MDAT_LSDOFF<br>X_PHC_PV_MDAT_LSD300      X_PHC_PV_MDAT_LSD1200<br>X_PHC_PV_MDAT_LSD4800    X_PHC_PV_MDAT_LSD6400<br>X_PHC_PV_MDAT_LSD8000    X_PHC_PV_MDAT_LSD9600<br>X_PHC_PV_MDAT_LSD14400   X_PHC_PV_MDAT_LSD16000<br>X_PHC_PV_MDAT_LSD24000   X_PHC_PV_MDAT_LSD32000<br>X_PHC_PV_MDAT_LSD40000   X_PHC_PV_MDAT_LSD48000<br>X_PHC_PV_MDAT_LSD56000   X_PHC_PV_MDAT_LSD62400<br>X_PHC_PV_MDAT_LSD64000   X_PHC_PV_MDAT_LSDVAR<br>X_PHC_PV_MDAT_MLPOFF<br>X_PHC_PV_MDAT_MLP4000    X_PHC_PV_MDAT_MLP6400<br>X_PHC_PV_MDAT_MLPVAR                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |  |                      |                   |                      |                                                           |                       |                                                            |                       |                                                            |                       |                                                            |                       |                                              |                       |                                                                        |
+| Default value         | none                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |  |                      |                   |                      |                                                           |                       |                                                            |                       |                                                            |                       |                                                            |                       |                                              |                       |                                                                        |
+| Description           | <p>This parameter is returned by the service provider in mode switch indications and confirmations. It indicates the current LSD/MLP receive bit rate. For each rate the occupied bits of the I-channel are mentioned. LSD and MLP may be switched on simultaneously, but the used bits must not overlap.</p> <p>A legal value of the LSD/MLP mode parameter is the bit-wise OR combination of one LSD value and one MLP value. The combination of variable LSD and variable MLP is not allowed. LSD and MLP both switched off is indicated by the value (X_PHC_PV_MDAT_LSDOFF   X_PHC_PV_MDAT_MLPOFF).</p> <table> <tr> <td>X_PHC_PV_MDAT_LSDOFF</td><td>LSD switched off;</td></tr> <tr> <td>X_PHC_PV_MDAT_LSD300</td><td>LSD on at fixed rate of 300 bit/s in SC, octets 38 to 40;</td></tr> <tr> <td>X_PHC_PV_MDAT_LSD1200</td><td>LSD on at fixed rate of 1200 bit/s in SC, octets 29 to 40;</td></tr> <tr> <td>X_PHC_PV_MDAT_LSD4800</td><td>LSD on at fixed rate of 4800 bit/s in SC, octets 33 to 80;</td></tr> <tr> <td>X_PHC_PV_MDAT_LSD6400</td><td>LSD on at fixed rate of 6400 bit/s in SC, octets 17 to 80;</td></tr> <tr> <td>X_PHC_PV_MDAT_LSD8000</td><td>LSD on at fixed rate of 8000 bit/s in bit 7;</td></tr> <tr> <td>X_PHC_PV_MDAT_LSD9600</td><td>LSD on at fixed rate of 9600 bit/s in bit 7 and octets 25 to 40 of SC;</td></tr> </table> |  | X_PHC_PV_MDAT_LSDOFF | LSD switched off; | X_PHC_PV_MDAT_LSD300 | LSD on at fixed rate of 300 bit/s in SC, octets 38 to 40; | X_PHC_PV_MDAT_LSD1200 | LSD on at fixed rate of 1200 bit/s in SC, octets 29 to 40; | X_PHC_PV_MDAT_LSD4800 | LSD on at fixed rate of 4800 bit/s in SC, octets 33 to 80; | X_PHC_PV_MDAT_LSD6400 | LSD on at fixed rate of 6400 bit/s in SC, octets 17 to 80; | X_PHC_PV_MDAT_LSD8000 | LSD on at fixed rate of 8000 bit/s in bit 7; | X_PHC_PV_MDAT_LSD9600 | LSD on at fixed rate of 9600 bit/s in bit 7 and octets 25 to 40 of SC; |
+| X_PHC_PV_MDAT_LSDOFF  | LSD switched off;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |  |                      |                   |                      |                                                           |                       |                                                            |                       |                                                            |                       |                                                            |                       |                                              |                       |                                                                        |
+| X_PHC_PV_MDAT_LSD300  | LSD on at fixed rate of 300 bit/s in SC, octets 38 to 40;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |  |                      |                   |                      |                                                           |                       |                                                            |                       |                                                            |                       |                                                            |                       |                                              |                       |                                                                        |
+| X_PHC_PV_MDAT_LSD1200 | LSD on at fixed rate of 1200 bit/s in SC, octets 29 to 40;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |  |                      |                   |                      |                                                           |                       |                                                            |                       |                                                            |                       |                                                            |                       |                                              |                       |                                                                        |
+| X_PHC_PV_MDAT_LSD4800 | LSD on at fixed rate of 4800 bit/s in SC, octets 33 to 80;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |  |                      |                   |                      |                                                           |                       |                                                            |                       |                                                            |                       |                                                            |                       |                                              |                       |                                                                        |
+| X_PHC_PV_MDAT_LSD6400 | LSD on at fixed rate of 6400 bit/s in SC, octets 17 to 80;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |  |                      |                   |                      |                                                           |                       |                                                            |                       |                                                            |                       |                                                            |                       |                                              |                       |                                                                        |
+| X_PHC_PV_MDAT_LSD8000 | LSD on at fixed rate of 8000 bit/s in bit 7;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |  |                      |                   |                      |                                                           |                       |                                                            |                       |                                                            |                       |                                                            |                       |                                              |                       |                                                                        |
+| X_PHC_PV_MDAT_LSD9600 | LSD on at fixed rate of 9600 bit/s in bit 7 and octets 25 to 40 of SC;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |  |                      |                   |                      |                                                           |                       |                                                            |                       |                                                            |                       |                                                            |                       |                                              |                       |                                                                        |
+
+**Table I.5-33/T.180 (concluded)**
+
+|                        |                                                                                                                      |
+|------------------------|----------------------------------------------------------------------------------------------------------------------|
+| X_PHC_PV_MDAT_LSD14400 | LSD on at fixed rate of 1200 bit/s in bit 7 and octets 25 to 40 of SC;                                               |
+| X_PHC_PV_MDAT_LSD16000 | LSD on at fixed rate of 16 000 bit/s in bits 6 and 7;                                                                |
+| X_PHC_PV_MDAT_LSD24000 | LSD on at fixed rate of 24 000 bit/s in bits 5 to 7;                                                                 |
+| X_PHC_PV_MDAT_LSD32000 | LSD on at fixed rate of 32 000 bit/s in bits 4 to 7;                                                                 |
+| X_PHC_PV_MDAT_LSD40000 | LSD on at fixed rate of 40 000 bit/s in bits 3 to 7;                                                                 |
+| X_PHC_PV_MDAT_LSD48000 | LSD on at fixed rate of 48 000 bit/s in bits 2 to 7;                                                                 |
+| X_PHC_PV_MDAT_LSD56000 | LSD on at fixed rate of 56 000 bit/s in bits 1 to 7;                                                                 |
+| X_PHC_PV_MDAT_LSD62400 | LSD on at fixed rate of 62 400 bit/s in bits 1 to 7 and octets 17 to 80 of SC;                                       |
+| X_PHC_PV_MDAT_LSD64000 | LSD on at fixed rate of 64 000 bit/s in bits 1 to 8, no framing;                                                     |
+| X_PHC_PV_MDAT_LSDVAR   | LSD on at variable rate occupying all I-channel capacity not allocated for audio, FAS, BAS, ECS, and fixed-rate MLP; |
+| X_PHC_PV_MDAT_MLPOFF   | MLP switched off;                                                                                                    |
+| X_PHC_PV_MDAT_MLP4000  | MLP on at fixed rate of 4000 bit/s in SC, octets 41 to 80;                                                           |
+| X_PHC_PV_MDAT_MLP6400  | MLP on at fixed rate of 6400 bit/s in SC, octets 17 to 80;                                                           |
+| X_PHC_PV_MDAT_MLPVAR   | MLP on at variable rate occupying all I-channel capacity not allocated for audio, FAS, BAS, ECS, and fixed rate LSD. |
+
+**Table I.5-34/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |  |
+|----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--|
+| Parameter name | X_PHC_P_RMOD_HDATA                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |  |
+| Type of value  | long                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |  |
+| Legal values   | <p> X_PHC_PV_MDHD_HSDOFF<br/> X_PHC_PV_MDHD_HSD64                      X_PHC_PV_MDHD_HSD128<br/> X_PHC_PV_MDHD_HSD192                  X_PHC_PV_MDHD_HSD256<br/> X_PHC_PV_MDHD_HSD320                  X_PHC_PV_MDHD_HSD384 </p> <p> X_PHC_PV_MDHD_HMLPOFF<br/> X_PHC_PV_MDHD_HMLP62                  X_PHC_PV_MDHD_HMLP128<br/> X_PHC_PV_MDHD_HMLP192                  X_PHC_PV_MDHD_HMLP256<br/> X_PHC_PV_MDHD_HMLP320                  X_PHC_PV_MDHD_HMLP384 </p>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |  |
+| Default value  | none                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |  |
+| Description    | <p>This parameter is returned by the service provider in mode switch indications and confirmations. It indicates the current HSD/H-MLP receive mode. For each mode the occupied time-slots of an H<sub>0</sub> or greater channel are mentioned. HSD and H-MLP may be switched on simultaneously, but the used time-slots must not overlap.</p> <p>A legal value of the HSD/H-MLP mode parameter is the bit-wise OR combination of one HSD value and one H-MLP value. HSD and H-MLP both switched off is indicated by the value (X_PHC_PV_MDHD_HSDOFF   X_PHC_PV_MDHD_HMLPOFF).</p> <p>NOTE – HSD/H-MLP commands are defined in Annex A/H.221.</p> <p> X_PHC_PV_MDHD_HSDOFF                  HSD switched off;<br/> X_PHC_PV_MDHD_HSD64                  HSD on in highest numbered channel/time-slot; FAS and BAS are removed in the case of multiple B-channels;<br/> <br/> X_PHC_PV_MDHD_HSD128                  HSD on in 2 highest-numbered time-slots of an H<sub>0</sub> or greater channel;<br/> X_PHC_PV_MDHD_HSD192                  HSD on in 3 highest-numbered time-slots of an H<sub>0</sub> or greater channel;<br/> X_PHC_PV_MDHD_HSD256                  HSD on in 4 highest-numbered time-slots of an H<sub>0</sub> or greater channel;<br/> X_PHC_PV_MDHD_HSD320                  HSD on in 5 highest-numbered time-slots of an H<sub>0</sub> or greater channel;<br/> X_PHC_PV_MDHD_HSD384                  HSD on in highest numbered H<sub>0</sub> channel, or 6 highest numbered time-slots of a greater channel; </p> |  |
+
+**Table I.5-34/T.180 (concluded)**
+
+|             |                       |                                                                                                   |
+|-------------|-----------------------|---------------------------------------------------------------------------------------------------|
+| Description | X_PHC_PV_MDHD_HMLPOFF | H-MLP switched off;                                                                               |
+|             | X_PHC_PV_MDHD_HMLP62  | H-MLP on at 62.4 kbit/s in the second B-channel, occupying all bits except FAS and BAS positions; |
+|             | X_PHC_PV_MDHD_HMLP64  | H-MLP on at 64 kbit/s in time-slot 2 of an H <sub>0</sub> or greater channel;                     |
+|             | X_PHC_PV_MDHD_HMLP128 | H-MLP on at 128 kbit/s in time-slots 2 and 3 of an H <sub>0</sub> or greater channel;             |
+|             | X_PHC_PV_MDHD_HMLP192 | H-MLP on at 192 kbit/s in time-slots 2 to 4 of an H <sub>0</sub> or greater channel;              |
+|             | X_PHC_PV_MDHD_HMLP256 | H-MLP on at 256 kbit/s in time-slots 2 to 5 of an H <sub>0</sub> or greater channel;              |
+|             | X_PHC_PV_MDHD_HMLP320 | H-MLP on at 320 kbit/s in time-slots 2 to 6 of an H <sub>0</sub> or greater channel;              |
+|             | X_PHC_PV_MDHD_HMLP384 | H-MLP on at 384 kbit/s in time-slots 2 to 7 of a channel greater than H <sub>0</sub> .            |
+
+**Table I.5-35/T.180**
+
+|                        |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |                        |                                       |                        |                                       |                       |                                          |                      |                         |                      |                         |                       |                                               |                       |                                               |
+|------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------|---------------------------------------|------------------------|---------------------------------------|-----------------------|------------------------------------------|----------------------|-------------------------|----------------------|-------------------------|-----------------------|-----------------------------------------------|-----------------------|-----------------------------------------------|
+| Parameter name         | X_PHC_P_RMOD_DATAPPL                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |                        |                                       |                        |                                       |                       |                                          |                      |                         |                      |                         |                       |                                               |                       |                                               |
+| Type of value          | long                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |                        |                                       |                        |                                       |                       |                                          |                      |                         |                      |                         |                       |                                               |                       |                                               |
+| Legal values           | X_PHC_PV_MDAP_LSDISOSP<br>X_PHC_PV_MDAP_HSDISOSP<br>X_PHC_PV_MDAP_LSDCURS<br>X_PHC_PV_MDAP_LSDFAX<br>X_PHC_PV_MDAP_HSDFAX<br>X_PHC_PV_MDAP_LSDV120<br>X_PHC_PV_MDAP_HSDV120                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |                        |                                       |                        |                                       |                       |                                          |                      |                         |                      |                         |                       |                                               |                       |                                               |
+| Default value          | none                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |                        |                                       |                        |                                       |                       |                                          |                      |                         |                      |                         |                       |                                               |                       |                                               |
+| Description            | <p>This parameter is returned by the service provider in mode switch indications and confirmations. It indicates to which application the data belong that are currently received as LSD resp. HSD. A legal value of the data application parameter is either a single LSD value, a single HSD value, or the bit-wise OR combination of one LSD value and one HSD value. (Note that LSD and HSD may be activated simultaneously.)</p> <table border="0"> <tr> <td>X_PHC_PV_MDAP_LSDISOSP</td> <td>ISO still picture switched on in LSD;</td> </tr> <tr> <td>X_PHC_PV_MDAP_HSDISOSP</td> <td>ISO still picture switched on in HSD;</td> </tr> <tr> <td>X_PHC_PV_MDAP_LSDCURS</td> <td>Graphics cursor data switched on in LSD;</td> </tr> <tr> <td>X_PHC_PV_MDAP_LSDFAX</td> <td>FAX switched on in LSD;</td> </tr> <tr> <td>X_PHC_PV_MDAP_HSDFAX</td> <td>FAX switched on in HSD;</td> </tr> <tr> <td>X_PHC_PV_MDAP_LSDV120</td> <td>V.120 terminal adaptation switched on in LSD;</td> </tr> <tr> <td>X_PHC_PV_MDAP_HSDV120</td> <td>V.120 terminal adaptation switched on in HSD.</td> </tr> </table> | X_PHC_PV_MDAP_LSDISOSP | ISO still picture switched on in LSD; | X_PHC_PV_MDAP_HSDISOSP | ISO still picture switched on in HSD; | X_PHC_PV_MDAP_LSDCURS | Graphics cursor data switched on in LSD; | X_PHC_PV_MDAP_LSDFAX | FAX switched on in LSD; | X_PHC_PV_MDAP_HSDFAX | FAX switched on in HSD; | X_PHC_PV_MDAP_LSDV120 | V.120 terminal adaptation switched on in LSD; | X_PHC_PV_MDAP_HSDV120 | V.120 terminal adaptation switched on in HSD. |
+| X_PHC_PV_MDAP_LSDISOSP | ISO still picture switched on in LSD;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |                        |                                       |                        |                                       |                       |                                          |                      |                         |                      |                         |                       |                                               |                       |                                               |
+| X_PHC_PV_MDAP_HSDISOSP | ISO still picture switched on in HSD;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |                        |                                       |                        |                                       |                       |                                          |                      |                         |                      |                         |                       |                                               |                       |                                               |
+| X_PHC_PV_MDAP_LSDCURS  | Graphics cursor data switched on in LSD;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |                        |                                       |                        |                                       |                       |                                          |                      |                         |                      |                         |                       |                                               |                       |                                               |
+| X_PHC_PV_MDAP_LSDFAX   | FAX switched on in LSD;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |                        |                                       |                        |                                       |                       |                                          |                      |                         |                      |                         |                       |                                               |                       |                                               |
+| X_PHC_PV_MDAP_HSDFAX   | FAX switched on in HSD;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |                        |                                       |                        |                                       |                       |                                          |                      |                         |                      |                         |                       |                                               |                       |                                               |
+| X_PHC_PV_MDAP_LSDV120  | V.120 terminal adaptation switched on in LSD;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |                        |                                       |                        |                                       |                       |                                          |                      |                         |                      |                         |                       |                                               |                       |                                               |
+| X_PHC_PV_MDAP_HSDV120  | V.120 terminal adaptation switched on in HSD.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |                        |                                       |                        |                                       |                       |                                          |                      |                         |                      |                         |                       |                                               |                       |                                               |
+
+**Table I.5-36/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |  |
+|----------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--|
+| Parameter name | X_PHC_P_RMOD_TFRATE                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |  |
+| Type of value  | long                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |  |
+| Legal values   | <div> <div> X_PHC_PV_MDTR_1X64<br/> X_PHC_PV_MDTR_3X64<br/> X_PHC_PV_MDTR_5X64<br/> X_PHC_PV_MDTR_1X384<br/> X_PHC_PV_MDTR_3X384<br/> X_PHC_PV_MDTR_5X384<br/> X_PHC_PV_MDTR_128<br/> X_PHC_PV_MDTR_256<br/> X_PHC_PV_MDTR_768<br/> X_PHC_PV_MDTR_1472<br/> X_PHC_PV_MDTR_1920 </div> <div> X_PHC_PV_MDTR_2X64<br/> X_PHC_PV_MDTR_4X64<br/> X_PHC_PV_MDTR_6X64<br/> X_PHC_PV_MDTR_2X384<br/> X_PHC_PV_MDTR_4X384<br/> X_PHC_PV_MDTR_192<br/> X_PHC_PV_MDTR_512<br/> X_PHC_PV_MDTR_1152<br/> X_PHC_PV_MDTR_1536 </div> </div>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |  |
+| Default value  | none                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |  |
+| Description    | <p>This parameter is returned by the service provider in mode switch indications and confirmations. It indicates the current receive transfer rate.</p> <p>If the transfer rate is less than the connected capacity, the information occupies the lowest-numbered channel(s)/time-slot(s).</p> <div> <div> X_PHC_PV_MDTR_1X64<br/> X_PHC_PV_MDTR_2X64<br/> X_PHC_PV_MDTR_3X64<br/> X_PHC_PV_MDTR_4X64<br/> X_PHC_PV_MDTR_5X64<br/> X_PHC_PV_MDTR_6X64<br/> X_PHC_PV_MDTR_1X384<br/> X_PHC_PV_MDTR_2X384<br/> X_PHC_PV_MDTR_3X384 channels<br/> X_PHC_PV_MDTR_4X384 channels<br/> X_PHC_PV_MDTR_5X384 </div> <div> Signal occupies one 64 kbit/s channel;<br/> Signal occupies two 64 kbit/s channels with FAS/BAS in each;<br/> Signal occupies three 64 kbit/s channels with FAS/BAS in each;<br/> Signal occupies four 64 kbit/s channels with FAS/BAS in each;<br/> Signal occupies five 64 kbit/s channels with FAS/BAS in each;<br/> Signal occupies six 64 kbit/s channels with FAS/BAS in each;<br/> Signal occupies one 384 kbit/s channels with FAS and BAS in the first 64 kbit/s time-slot. The effective channel may be the whole of an H<sub>0</sub> channel or the lowest-numbered time-slots of an H<sub>11</sub> or an H<sub>12</sub> channel;<br/> Signal occupies two 384 kbit/s channels with FAS/BAS in each;<br/> Signal occupies three 384 kbit/s with FAS/BAS in each;<br/> Signal occupies four 384 kbit/s with FAS/BAS in each;<br/> Signal occupies five 384 kbit/s channels with FAS/BAS in each; </div> </div> |  |
+
+**Table I.5-36/T.180 (concluded)**
+
+|  |                    |                                                                                                                                                                                                        |
+|--|--------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+|  | X_PHC_PV_MDTR_128  | Signal occupies 128 kbit/s, with FAS and BAS in the first 64 kbit/s time-slot (TS1). The effective channel occupies the lowest-numbered time-slots of a channel with corresponding or higher capacity; |
+|  | X_PHC_PV_MDTR_192  | Signal occupies 192 kbit/s, with FAS and BAS in TS1;                                                                                                                                                   |
+|  | X_PHC_PV_MDTR_256  | Signal occupies 256 kbit/s, with FAS and BAS in TS1;                                                                                                                                                   |
+|  | X_PHC_PV_MDTR_512  | Signal occupies 512 kbit/s, with FAS and BAS in TS1;                                                                                                                                                   |
+|  | X_PHC_PV_MDTR_768  | Signal occupies 768 kbit/s, with FAS and BAS in TS1;                                                                                                                                                   |
+|  | X_PHC_PV_MDTR_1152 | Signal occupies 1152 kbit/s, with FAS and BAS in TS1;                                                                                                                                                  |
+|  | X_PHC_PV_MDTR_1472 | Signal occupies 1472 kbit/s, with FAS and BAS in TS1;                                                                                                                                                  |
+|  | X_PHC_PV_MDTR_1536 | Signal occupies 1536 kbit/s, with FAS and BAS in TS1;                                                                                                                                                  |
+|  | X_PHC_PV_MDTR_1920 | Signal occupies 1920 kbit/s, with FAS and BAS in TS1.                                                                                                                                                  |
+
+**Table I.5-37/T.180**
+
+|                     |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |  |                    |                                             |                     |                                            |                     |                                                                                                                                           |
+|---------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--|--------------------|---------------------------------------------|---------------------|--------------------------------------------|---------------------|-------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name      | X_PHC_P_RMOD_SYNC                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |  |                    |                                             |                     |                                            |                     |                                                                                                                                           |
+| Type of value       | long                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |  |                    |                                             |                     |                                            |                     |                                                                                                                                           |
+| Legal values        | X_PHC_PV_MDSY_NONE<br>X_PHC_PV_MDSY_ICHAN<br>X_PHC_PV_MDSY_ACHAN                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |  |                    |                                             |                     |                                            |                     |                                                                                                                                           |
+| Default value       | none                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |  |                    |                                             |                     |                                            |                     |                                                                                                                                           |
+| Description         | <p>This parameter is returned by the service provider in mode switch indications and confirmations. It indicates the current synchronization status in receive direction.</p> <table> <tr> <td>X_PHC_PV_MDSY_NONE</td><td>All incoming signals are received unframed;</td></tr> <tr> <td>X_PHC_PV_MDSY_ICHAN</td><td>FAS and BAS are received in the I-channel;</td></tr> <tr> <td>X_PHC_PV_MDSY_ACHAN</td><td>FAS and BAS are received in all additional channels and they are synchronized with the I-channel, i.e. multiframe alignment is validated.</td></tr> </table> |  | X_PHC_PV_MDSY_NONE | All incoming signals are received unframed; | X_PHC_PV_MDSY_ICHAN | FAS and BAS are received in the I-channel; | X_PHC_PV_MDSY_ACHAN | FAS and BAS are received in all additional channels and they are synchronized with the I-channel, i.e. multiframe alignment is validated. |
+| X_PHC_PV_MDSY_NONE  | All incoming signals are received unframed;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |  |                    |                                             |                     |                                            |                     |                                                                                                                                           |
+| X_PHC_PV_MDSY_ICHAN | FAS and BAS are received in the I-channel;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |  |                    |                                             |                     |                                            |                     |                                                                                                                                           |
+| X_PHC_PV_MDSY_ACHAN | FAS and BAS are received in all additional channels and they are synchronized with the I-channel, i.e. multiframe alignment is validated.                                                                                                                                                                                                                                                                                                                                                                                                                                   |  |                    |                                             |                     |                                            |                     |                                                                                                                                           |
+
+**Table I.5-38/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
+|----------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_PHC_P_RMOD_MISC                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
+| Type of value  | long                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
+| Legal values   | X_PHC_PV_MDMS_ECSACT<br>X_PHC_PV_MDMS_6BH0COMP<br>X_PHC_PV_MDMS_RESTRICT<br>X_PHC_PV_MDMS_DERESTRICT                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
+| Default value  | none                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
+| Description    | <p>This parameter is returned by the service provider in mode switch indications and confirmations. It indicates miscellaneous attributes currently active in receive direction. The attributes are independent and represented as one bit within the parameter value. If the bit is set to 1, the attribute is active; otherwise, it is inactive. The bit-wise AND operator can be used to check a single attribute from the parameter value.</p> <p>X_PHC_PV_MDMS_ECSACT                      ECS channel active;</p> <p>X_PHC_PV_MDMS_6BH0COMP                  6B-H<sub>0</sub> compatibility mode is active.<br/>(For H<sub>0</sub> terminals only);</p> <p>X_PHC_PV_MDMS_RESTRICT                  Communicating over a restricted network<br/>(Bit 7 of the I-channel is treated as SC<br/>and bit 8 is discarded in every other<br/>channel);</p> <p>X_PHC_PV_MDMS_DERESTRICT              Revert to unrestricted network operation<br/>(Bit 8 of the I-channel is treated as SC).</p> |
+
+###### **I.5.7.3.2.4 Transmit mode parameters**
+
+**Table I.5-39/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                             |
+|----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_PHC_P_TMOD_AUDIO                                                                                                                                                                                                                                                                                                                                                          |
+| Type of value  | long                                                                                                                                                                                                                                                                                                                                                                        |
+| Legal values   | X_PHC_PV_MDAU_OFF_U<br>X_PHC_PV_MDAU_OFF_F<br>X_PHC_PV_MDAU_G711A_U<br>X_PHC_PV_MDAU_G711A_F<br>X_PHC_PV_MDAU_G711U_U<br>X_PHC_PV_MDAU_G711U_F<br>X_PHC_PV_MDAU_G722_M1<br>X_PHC_PV_MDAU_G722_M2<br>X_PHC_PV_MDAU_G722_M3<br>X_PHC_PV_MDAU_ISO_64<br>X_PHC_PV_MDAU_ISO_128<br>X_PHC_PV_MDAU_ISO_192<br>X_PHC_PV_MDAU_ISO_256<br>X_PHC_PV_MDAU_ISO_384<br>X_PHC_PV_MDAU_G728 |
+
+**Table I.5-39/T.180 (concluded)**
+
+|               |                                                                                                                                                                                                                                                                                                                                                                                                                             |
+|---------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Default value | none                                                                                                                                                                                                                                                                                                                                                                                                                        |
+| Description   | <p>This parameter may be specified in a mode switch request to select the audio mode to be used in transmit direction.</p> <p>The parameter is returned by the service provider in mode switch indications and confirmations. There it indicates the currently active audio mode in transmit direction.</p> <p>See the corresponding receive mode parameter X_PHC_P_RMOD_AUDIO for a description of the defined values.</p> |
+
+**Table I.5-40/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
+|----------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_PHC_P_TMOD_VIDEO                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
+| Type of value  | long                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
+| Legal values   | X_PHC_PV_MDVI_OFF<br>X_PHC_PV_MDVI_H261<br>X_PHC_PV_MDVI_ISO<br>X_PHC_PV_MDVI_AVISO<br>X_PHC_PV_MDVI_PINV1<br>X_PHC_PV_MDVI_PINV2<br>X_PHC_PV_MDVI_PINV3<br>X_PHC_PV_MDVI_PINV4                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
+| Default value  | none                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
+| Description    | <p>This parameter may be specified in a mode switch request to select the video mode to be used in transmit direction.</p> <p>The parameter is returned by the service provider in mode switch indications and confirmations. There it indicates the currently active video mode in transmit direction.</p> <p>See the corresponding receive mode parameter X_PHC_P_RMOD_VIDEO for a description of the defined values.</p> <p>A legal value of the video mode parameter is either X_PHC_PV_MDVI_OFF or a combination of one video coding value, one video picture format value, and one video frame rate value. The bit-wise OR operator is used to combine the three values.</p> |
+
+**Table I.5-41/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |  |
+|----------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--|
+| Parameter name | X_PHC_P_TMOD_DATA                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |  |
+| Type of value  | long                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |  |
+| Legal values   | X_PHC_PV_MDAT_LSDOFF<br>X_PHC_PV_MDAT_LSD300                      X_PHC_PV_MDAT_LSD1200<br>X_PHC_PV_MDAT_LSD4800                  X_PHC_PV_MDAT_LSD6400<br>X_PHC_PV_MDAT_LSD8000                  X_PHC_PV_MDAT_LSD9600<br>X_PHC_PV_MDAT_LSD14400                X_PHC_PV_MDAT_LSD16000<br>X_PHC_PV_MDAT_LSD24000                X_PHC_PV_MDAT_LSD32000<br>X_PHC_PV_MDAT_LSD40000                X_PHC_PV_MDAT_LSD48000<br>X_PHC_PV_MDAT_LSD56000                X_PHC_PV_MDAT_LSD62400<br>X_PHC_PV_MDAT_LSD64000                X_PHC_PV_MDAT_LSDVAR<br><br>X_PHC_PV_MDAT_MLPOFF<br>X_PHC_PV_MDAT_MLP4000                  X_PHC_PV_MDAT_MLP6400<br>X_PHC_PV_MDAT_MLPVAR                                                                      |  |
+| Default value  | none                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |  |
+| Description    | <p>This parameter may be specified in a mode switch request to switch on/off LSD or MLP in transmit direction at a certain bit rate. LSD and MLP may be switched on simultaneously, but the occupied bits of the I-channel must not overlap.</p> <p>The parameter is returned by the service provider in mode switch indications and confirmations. There it indicates the currently enabled LSD/MLP bit rate in transmit direction.</p> <p>See the corresponding receive mode parameter X_PHC_P_RMOD_DATA for a description of the defined values.</p> <p>A legal value of the LSD/MLP mode parameter is the bit-wise OR combination of one LSD value and one MLP value. The combination of variable LSD and variable MLP is not allowed.</p> |  |
+
+**Table I.5-42/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                                                             |  |
+|----------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--|
+| Parameter name | X_PHC_P_TMOD_HDATA                                                                                                                                                                                                                                                                                                                                                                                                                          |  |
+| Type of value  | long                                                                                                                                                                                                                                                                                                                                                                                                                                        |  |
+| Legal values   | X_PHC_PV_MDHD_HSDOFF<br>X_PHC_PV_MDHD_HSD64                      X_PHC_PV_MDHD_HSD128<br>X_PHC_PV_MDHD_HSD192                  X_PHC_PV_MDHD_HSD256<br>X_PHC_PV_MDHD_HSD320                  X_PHC_PV_MDHD_HSD384<br>X_PHC_PV_MDHD_HMLPOFF<br>X_PHC_PV_MDHD_HMLP62                    X_PHC_PV_MDHD_HMLP128<br>X_PHC_PV_MDHD_HMLP192                  X_PHC_PV_MDHD_HMLP256<br>X_PHC_PV_MDHD_HMLP320                  X_PHC_PV_MDHD_HMLP384 |  |
+
+**Table I.5-42/T.180 (concluded)**
+
+|               |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
+|---------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Default value | none                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
+| Description   | <p>This parameter may be specified in a mode switch request to switch on/off HSD or H-MLP in transmit direction at a certain bit rate. HSD and H-MLP may be switched on simultaneously, but the occupied time-slots of an <math>H_0</math> or greater channel must not overlap.</p> <p>The parameter is returned by the service provider in mode switch indications and confirmations. There it indicates the currently enabled HSD/H-MLP bit rate in transmit direction.</p> <p>See the corresponding receive mode parameter X_PHC_P_RMOD_HDATA for a description of the defined values.</p> <p>A legal value of the HSD/H-MLP mode parameter is the bit-wise OR combination of one HSD value and one H-MLP value.</p> |
+
+**Table I.5-43/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
+|----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_PHC_P_TMOD_DATAPPL                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
+| Type of value  | long                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
+| Legal values   | X_PHC_PV_MDAP_LSDISOSP<br>X_PHC_PV_MDAP_HSDISOSP<br>X_PHC_PV_MDAP_LSDCURS<br>X_PHC_PV_MDAP_LSDFAX<br>X_PHC_PV_MDAP_HSDFAX<br>X_PHC_PV_MDAP_LSDV120<br>X_PHC_PV_MDAP_HSDV120                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
+| Default value  | none                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
+| Description    | <p>This parameter may be specified in a mode switch request to define the application that transmits data as LSD or HSD. The information is passed to the remote terminal as a BAS command. A legal value of the data application parameter is either a single LSD value, a single HSD value, or the bit-wise OR combination of one LSD value and one HSD value. (Note that LSD and HSD may be activated simultaneously.)</p> <p>The parameter is returned by the service provider in mode switch indications and confirmations. It indicates which application currently uses LSD or HSD for transmission.</p> <p>See the corresponding receive mode parameter X_PHC_P_RMOD_DATAPPL for a description of the defined values.</p> |
+
+**Table I.5-44/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
+|----------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_PHC_P_TMOD_TFRATE                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
+| Type of value  | long                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
+| Legal values   | X_PHC_PV_MDTR_1X64<br>X_PHC_PV_MDTR_2X64<br>X_PHC_PV_MDTR_3X64<br>X_PHC_PV_MDTR_4X64<br>X_PHC_PV_MDTR_5X64<br>X_PHC_PV_MDTR_6X64<br>X_PHC_PV_MDTR_1X384<br>X_PHC_PV_MDTR_2X384<br>X_PHC_PV_MDTR_3X384<br>X_PHC_PV_MDTR_4X384<br>X_PHC_PV_MDTR_5X384<br>X_PHC_PV_MDTR_128<br>X_PHC_PV_MDTR_192<br>X_PHC_PV_MDTR_256<br>X_PHC_PV_MDTR_512<br>X_PHC_PV_MDTR_768<br>X_PHC_PV_MDTR_1152<br>X_PHC_PV_MDTR_1472<br>X_PHC_PV_MDTR_1536<br>X_PHC_PV_MDTR_1920                                                                                                                                                                                                                                                                                                                                                                                                                                         |
+| Default value  | none                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
+| Description    | <p>This parameter may be specified in a mode switch request to select the transfer rate in transmit direction. The specified value must not exceed the available connected capacity. If it is less than the connected capacity, the information occupies the lowest-numbered channel(s)/time-slot(s).</p> <p>Note the difference between e.g. X_PHC_PV_MDTR_2X64 and X_PHC_PV_MDTR_128. The first value is applicable for a connected capacity of two or more B-channels only, whereas the second can only be used if the connected capacity is a H<sub>0</sub> or greater channel.</p> <p>The parameter is returned by the service provider in mode switch indications and confirmations. There it indicates the currently active transfer rate in transmit direction.</p> <p>See the corresponding receive mode parameter X_PHC_P_RMOD_TFRATE for a description of the defined values.</p> |
+
+**Table I.5-45/T.180**
+
+|                       |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |  |                      |                                           |                       |                                                                                   |                       |                                                                                                                                             |
+|-----------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--|----------------------|-------------------------------------------|-----------------------|-----------------------------------------------------------------------------------|-----------------------|---------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name        | X_PHC_P_TMOD_SYNC                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |  |                      |                                           |                       |                                                                                   |                       |                                                                                                                                             |
+| Type of value         | long                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |  |                      |                                           |                       |                                                                                   |                       |                                                                                                                                             |
+| Legal values          | X_PHC_PV_MDSY_UNFRAM<br>X_PHC_PV_MDSY_IC_FRMD<br>X_PHC_PV_MDSY_AC_FRMD                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |  |                      |                                           |                       |                                                                                   |                       |                                                                                                                                             |
+| Default value         | none                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |  |                      |                                           |                       |                                                                                   |                       |                                                                                                                                             |
+| Description           | <p>This parameter is returned by the service provider in mode switch indications and confirmations. It indicates the currently synchronization state in transmit direction.</p> <table> <tr> <td>X_PHC_PV_MDSY_UNFRAM</td><td>Transmission is unframed in all channels.</td></tr> <tr> <td>X_PHC_PV_MDSY_IC_FRMD</td><td>FAS and BAS are transmitted in the I-channel and the remote terminal sends A = 0;</td></tr> <tr> <td>X_PHC_PV_MDSY_AC_FRMD</td><td>FAS and BAS are transmitted in all additional channels and the remote terminal sends A = 0 in each, i.e. multiframe alignment is validated.</td></tr> </table> |  | X_PHC_PV_MDSY_UNFRAM | Transmission is unframed in all channels. | X_PHC_PV_MDSY_IC_FRMD | FAS and BAS are transmitted in the I-channel and the remote terminal sends A = 0; | X_PHC_PV_MDSY_AC_FRMD | FAS and BAS are transmitted in all additional channels and the remote terminal sends A = 0 in each, i.e. multiframe alignment is validated. |
+| X_PHC_PV_MDSY_UNFRAM  | Transmission is unframed in all channels.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |  |                      |                                           |                       |                                                                                   |                       |                                                                                                                                             |
+| X_PHC_PV_MDSY_IC_FRMD | FAS and BAS are transmitted in the I-channel and the remote terminal sends A = 0;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |  |                      |                                           |                       |                                                                                   |                       |                                                                                                                                             |
+| X_PHC_PV_MDSY_AC_FRMD | FAS and BAS are transmitted in all additional channels and the remote terminal sends A = 0 in each, i.e. multiframe alignment is validated.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |  |                      |                                           |                       |                                                                                   |                       |                                                                                                                                             |
+
+**Table I.5-46/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |  |
+|----------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--|
+| Parameter name | X_PHC_P_TMOD_MISC                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |  |
+| Type of value  | long                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |  |
+| Legal values   | X_PHC_PV_MDMS_ECSACT<br>X_PHC_PV_MDMS_6BH0COMP<br>X_PHC_PV_MDMS_RESTRICT<br>X_PHC_PV_MDMS_DERESTRICT                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |  |
+| Default value  | none                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |  |
+| Description    | <p>This parameter may be specified in a mode switch request to define miscellaneous attributes that shall be active in transmit direction. The attributes are independent and represented as one bit within the parameter value. If the bit is set to 1, the attribute is active; otherwise, it is not active. The bit-wise AND operator can be used to select a single attribute from the parameter value.</p> <p>The parameter is returned by the service provider in mode switch indications and confirmations. It indicates which miscellaneous attributes are currently active for transmission.</p> <p>See the corresponding receive mode parameter X_PHC_P_RMOD_MISC for a description of the defined values.</p> |  |
+
+###### I.5.7.3.2.5 Transfer line parameters
+
+**Table I.5-47/T.180**
+
+|                    |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |                    |               |                   |                                                  |                   |                                                    |                   |                                                    |                   |                                                    |                   |                                                    |                   |                                                    |                    |                                                                 |                    |                                                                  |                    |                                                                   |                    |                                                                   |                    |                                                                   |                   |                                                                   |                   |                                                                   |
+|--------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------|---------------|-------------------|--------------------------------------------------|-------------------|----------------------------------------------------|-------------------|----------------------------------------------------|-------------------|----------------------------------------------------|-------------------|----------------------------------------------------|-------------------|----------------------------------------------------|--------------------|-----------------------------------------------------------------|--------------------|------------------------------------------------------------------|--------------------|-------------------------------------------------------------------|--------------------|-------------------------------------------------------------------|--------------------|-------------------------------------------------------------------|-------------------|-------------------------------------------------------------------|-------------------|-------------------------------------------------------------------|
+| Parameter name     | X_PHC_P_MODE_TFLINES                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |                    |               |                   |                                                  |                   |                                                    |                   |                                                    |                   |                                                    |                   |                                                    |                   |                                                    |                    |                                                                 |                    |                                                                  |                    |                                                                   |                    |                                                                   |                    |                                                                   |                   |                                                                   |                   |                                                                   |
+| Type of value      | long                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |                    |               |                   |                                                  |                   |                                                    |                   |                                                    |                   |                                                    |                   |                                                    |                   |                                                    |                    |                                                                 |                    |                                                                  |                    |                                                                   |                    |                                                                   |                    |                                                                   |                   |                                                                   |                   |                                                                   |
+| Legal values       | <p>X_PHC_PV_MDTL_NONE</p> <p>X_PHC_PV_MDTL_1XB<br/>X_PHC_PV_MDTL_2XB<br/>X_PHC_PV_MDTL_3XB<br/>X_PHC_PV_MDTL_4XB<br/>X_PHC_PV_MDTL_5XB<br/>X_PHC_PV_MDTL_6XB</p> <p>X_PHC_PV_MDTL_1XH0<br/>X_PHC_PV_MDTL_2XH0<br/>X_PHC_PV_MDTL_3XH0<br/>X_PHC_PV_MDTL_4XH0<br/>X_PHC_PV_MDTL_5XH0</p> <p>X_PHC_PV_MDTL_H11<br/>X_PHC_PV_MDTL_H12</p>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |                    |               |                   |                                                  |                   |                                                    |                   |                                                    |                   |                                                    |                   |                                                    |                   |                                                    |                    |                                                                 |                    |                                                                  |                    |                                                                   |                    |                                                                   |                    |                                                                   |                   |                                                                   |                   |                                                                   |
+| Default value      | none                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |                    |               |                   |                                                  |                   |                                                    |                   |                                                    |                   |                                                    |                   |                                                    |                   |                                                    |                    |                                                                 |                    |                                                                  |                    |                                                                   |                    |                                                                   |                    |                                                                   |                   |                                                                   |                   |                                                                   |
+| Description        | <p>This parameter indicates the number of connected lines. Note that there is no difference between receive and transmit directions because each line can be used in both directions.</p> <table> <tr> <td>X_PHC_PV_MDTL_NONE</td> <td>No connection</td> </tr> <tr> <td>X_PHC_PV_MDTL_1XB</td> <td>1 B-channel connected; total capacity 64 kbit/s;</td> </tr> <tr> <td>X_PHC_PV_MDTL_2XB</td> <td>2 B-channels connected; total capacity 128 kbit/s;</td> </tr> <tr> <td>X_PHC_PV_MDTL_3XB</td> <td>3 B-channels connected; total capacity 192 kbit/s;</td> </tr> <tr> <td>X_PHC_PV_MDTL_4XB</td> <td>4 B-channels connected; total capacity 256 kbit/s;</td> </tr> <tr> <td>X_PHC_PV_MDTL_5XB</td> <td>5 B-channels connected; total capacity 320 kbit/s;</td> </tr> <tr> <td>X_PHC_PV_MDTL_6XB</td> <td>6 B-channels connected; total capacity 384 kbit/s;</td> </tr> <tr> <td>X_PHC_PV_MDTL_1XH0</td> <td>1 H<sub>0</sub>-channel connected; total capacity 384 kbit/s;</td> </tr> <tr> <td>X_PHC_PV_MDTL_2XH0</td> <td>2 H<sub>0</sub>-channels connected; total capacity 768 kbit/s;</td> </tr> <tr> <td>X_PHC_PV_MDTL_3XH0</td> <td>3 H<sub>0</sub>-channels connected; total capacity 1152 kbit/s;</td> </tr> <tr> <td>X_PHC_PV_MDTL_4XH0</td> <td>4 H<sub>0</sub>-channels connected; total capacity 1536 kbit/s;</td> </tr> <tr> <td>X_PHC_PV_MDTL_5XH0</td> <td>5 H<sub>0</sub>-channels connected; total capacity 1920 kbit/s;</td> </tr> <tr> <td>X_PHC_PV_MDTL_H11</td> <td>1 H<sub>11</sub>-channel connected; total capacity 1536 kbit/s;</td> </tr> <tr> <td>X_PHC_PV_MDTL_H12</td> <td>1 H<sub>12</sub>-channel connected; total capacity 1920 kbit/s.</td> </tr> </table> | X_PHC_PV_MDTL_NONE | No connection | X_PHC_PV_MDTL_1XB | 1 B-channel connected; total capacity 64 kbit/s; | X_PHC_PV_MDTL_2XB | 2 B-channels connected; total capacity 128 kbit/s; | X_PHC_PV_MDTL_3XB | 3 B-channels connected; total capacity 192 kbit/s; | X_PHC_PV_MDTL_4XB | 4 B-channels connected; total capacity 256 kbit/s; | X_PHC_PV_MDTL_5XB | 5 B-channels connected; total capacity 320 kbit/s; | X_PHC_PV_MDTL_6XB | 6 B-channels connected; total capacity 384 kbit/s; | X_PHC_PV_MDTL_1XH0 | 1 H <sub>0</sub> -channel connected; total capacity 384 kbit/s; | X_PHC_PV_MDTL_2XH0 | 2 H <sub>0</sub> -channels connected; total capacity 768 kbit/s; | X_PHC_PV_MDTL_3XH0 | 3 H <sub>0</sub> -channels connected; total capacity 1152 kbit/s; | X_PHC_PV_MDTL_4XH0 | 4 H <sub>0</sub> -channels connected; total capacity 1536 kbit/s; | X_PHC_PV_MDTL_5XH0 | 5 H <sub>0</sub> -channels connected; total capacity 1920 kbit/s; | X_PHC_PV_MDTL_H11 | 1 H <sub>11</sub> -channel connected; total capacity 1536 kbit/s; | X_PHC_PV_MDTL_H12 | 1 H <sub>12</sub> -channel connected; total capacity 1920 kbit/s. |
+| X_PHC_PV_MDTL_NONE | No connection                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |                    |               |                   |                                                  |                   |                                                    |                   |                                                    |                   |                                                    |                   |                                                    |                   |                                                    |                    |                                                                 |                    |                                                                  |                    |                                                                   |                    |                                                                   |                    |                                                                   |                   |                                                                   |                   |                                                                   |
+| X_PHC_PV_MDTL_1XB  | 1 B-channel connected; total capacity 64 kbit/s;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |                    |               |                   |                                                  |                   |                                                    |                   |                                                    |                   |                                                    |                   |                                                    |                   |                                                    |                    |                                                                 |                    |                                                                  |                    |                                                                   |                    |                                                                   |                    |                                                                   |                   |                                                                   |                   |                                                                   |
+| X_PHC_PV_MDTL_2XB  | 2 B-channels connected; total capacity 128 kbit/s;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |                    |               |                   |                                                  |                   |                                                    |                   |                                                    |                   |                                                    |                   |                                                    |                   |                                                    |                    |                                                                 |                    |                                                                  |                    |                                                                   |                    |                                                                   |                    |                                                                   |                   |                                                                   |                   |                                                                   |
+| X_PHC_PV_MDTL_3XB  | 3 B-channels connected; total capacity 192 kbit/s;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |                    |               |                   |                                                  |                   |                                                    |                   |                                                    |                   |                                                    |                   |                                                    |                   |                                                    |                    |                                                                 |                    |                                                                  |                    |                                                                   |                    |                                                                   |                    |                                                                   |                   |                                                                   |                   |                                                                   |
+| X_PHC_PV_MDTL_4XB  | 4 B-channels connected; total capacity 256 kbit/s;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |                    |               |                   |                                                  |                   |                                                    |                   |                                                    |                   |                                                    |                   |                                                    |                   |                                                    |                    |                                                                 |                    |                                                                  |                    |                                                                   |                    |                                                                   |                    |                                                                   |                   |                                                                   |                   |                                                                   |
+| X_PHC_PV_MDTL_5XB  | 5 B-channels connected; total capacity 320 kbit/s;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |                    |               |                   |                                                  |                   |                                                    |                   |                                                    |                   |                                                    |                   |                                                    |                   |                                                    |                    |                                                                 |                    |                                                                  |                    |                                                                   |                    |                                                                   |                    |                                                                   |                   |                                                                   |                   |                                                                   |
+| X_PHC_PV_MDTL_6XB  | 6 B-channels connected; total capacity 384 kbit/s;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |                    |               |                   |                                                  |                   |                                                    |                   |                                                    |                   |                                                    |                   |                                                    |                   |                                                    |                    |                                                                 |                    |                                                                  |                    |                                                                   |                    |                                                                   |                    |                                                                   |                   |                                                                   |                   |                                                                   |
+| X_PHC_PV_MDTL_1XH0 | 1 H <sub>0</sub> -channel connected; total capacity 384 kbit/s;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |                    |               |                   |                                                  |                   |                                                    |                   |                                                    |                   |                                                    |                   |                                                    |                   |                                                    |                    |                                                                 |                    |                                                                  |                    |                                                                   |                    |                                                                   |                    |                                                                   |                   |                                                                   |                   |                                                                   |
+| X_PHC_PV_MDTL_2XH0 | 2 H <sub>0</sub> -channels connected; total capacity 768 kbit/s;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |                    |               |                   |                                                  |                   |                                                    |                   |                                                    |                   |                                                    |                   |                                                    |                   |                                                    |                    |                                                                 |                    |                                                                  |                    |                                                                   |                    |                                                                   |                    |                                                                   |                   |                                                                   |                   |                                                                   |
+| X_PHC_PV_MDTL_3XH0 | 3 H <sub>0</sub> -channels connected; total capacity 1152 kbit/s;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |                    |               |                   |                                                  |                   |                                                    |                   |                                                    |                   |                                                    |                   |                                                    |                   |                                                    |                    |                                                                 |                    |                                                                  |                    |                                                                   |                    |                                                                   |                    |                                                                   |                   |                                                                   |                   |                                                                   |
+| X_PHC_PV_MDTL_4XH0 | 4 H <sub>0</sub> -channels connected; total capacity 1536 kbit/s;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |                    |               |                   |                                                  |                   |                                                    |                   |                                                    |                   |                                                    |                   |                                                    |                   |                                                    |                    |                                                                 |                    |                                                                  |                    |                                                                   |                    |                                                                   |                    |                                                                   |                   |                                                                   |                   |                                                                   |
+| X_PHC_PV_MDTL_5XH0 | 5 H <sub>0</sub> -channels connected; total capacity 1920 kbit/s;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |                    |               |                   |                                                  |                   |                                                    |                   |                                                    |                   |                                                    |                   |                                                    |                   |                                                    |                    |                                                                 |                    |                                                                  |                    |                                                                   |                    |                                                                   |                    |                                                                   |                   |                                                                   |                   |                                                                   |
+| X_PHC_PV_MDTL_H11  | 1 H <sub>11</sub> -channel connected; total capacity 1536 kbit/s;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |                    |               |                   |                                                  |                   |                                                    |                   |                                                    |                   |                                                    |                   |                                                    |                   |                                                    |                    |                                                                 |                    |                                                                  |                    |                                                                   |                    |                                                                   |                    |                                                                   |                   |                                                                   |                   |                                                                   |
+| X_PHC_PV_MDTL_H12  | 1 H <sub>12</sub> -channel connected; total capacity 1920 kbit/s.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |                    |               |                   |                                                  |                   |                                                    |                   |                                                    |                   |                                                    |                   |                                                    |                   |                                                    |                    |                                                                 |                    |                                                                  |                    |                                                                   |                    |                                                                   |                    |                                                                   |                   |                                                                   |                   |                                                                   |
+
+**Table I.5-48/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
+|----------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_PHC_P_NUM_LINES                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
+| Type of value  | long                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
+| Legal values   | 1 ... 5                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
+| Default value  | none                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
+| Description    | <p>This parameter is mandatory for add line requests and hang-up line requests. In case of add line it specifies the number of additional channels to be established and in case of hang-up line the number of additional channels to be closed.</p> <p>The parameter is returned by an add line confirmation. There it indicates the number of successfully established new channels.</p> <p>Including the initial channel, at most the number of lines indicated by the value of the X_PHC_P_LCAP_TFLINES parameter will be established. The value of X_PHC_P_NUM_LINES will be decremented internally if the requested value plus the number of already established channels would exceed this maximum value.</p> |
+
+**Table I.5-49/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
+|----------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_A_OUTBAND_ADR                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
+| Type of value  | unsigned char []                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
+| Legal values   | See the corresponding clause in the main part of this Recommendation.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
+| Default value  | none                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
+| Description    | <p>This parameter is mandatory for add line requests. It specifies one outband address (phone number) to be used for establishment of an additional channel. The parameter may be specified more than once in the parameter buffer, at most five times. Note that the number of channels to be established is defined by the X_PHC_P_NUM_LINES parameter and not by the number of addresses. Additional addresses are ignored.</p> <p>The parameter is returned in an add line confirmation if an additional channel was successfully established. The value is one of the addresses specified in the request. It indicates the number used to dial up the channel. The parameter will appear in the parameter buffer as many times as new additional channels were established.</p> |
+
+##### **I.5.7.3.3 Data Transfer service**
+
+Beside the AV communication, additional channels for asynchronous data transfer may be activated with the Mode Switch service. The data transfer service enables the application program to access a previously activated data channel. The audio and video channels cannot be accessed with the Data Transfer service. Other services have to be used to control AV communication.
+
+NOTE 1 – According to Recommendation H.242 and T.120, MLP and H-MLP are combined to a single MLP subchannel, if both are activated. The bit rate of the combined channel is the sum of the MLP and H-MLP bit rates.
+
+NOTE 2 – Activated data channels occupy a part of the total bandwidth and thus decrease the available bandwidth for video data. Audio bandwidth is not influenced by the activation of data channels.
+
+NOTE 3 – LSD and HSD channels can be used in one direction only. To get a full-duplex connection for asynchronous data transfer, both terminals have to activate an LSD or HSD channel. The bit rates need not necessarily be the same in both directions.
+
+###### I.5.7.3.3.1 Service description
+
+The Data Transfer service comprises two elements. The XAPI function *x\_snddata()* is used to transmit data on a previously established data channel, and the XAPI function *x\_rcvdata()* is used to receive data from a data channel.
+
+If a data channel has been opened for receiving, the service provider will store data at the service endpoint until it is received by the application with an *x\_rcvdata()* call. If the application does not call *x\_rcvdata()* for a longer time, the service provider may run out of storage if no flow control mechanism is used that would stop the sender before this happens. In case of data overflow, some or all of the stored data is released without notification. To avoid loss of data, an application should call *x\_rcvdata()* as soon as data is available at the service endpoint.
+
+The service elements and their corresponding XAPI functions needed for Data Transfer are described in Table I.5-50.
+
+**Table I.5-50/T.180 – Service elements and their corresponding XAPI functions for Data Transfer**
+
+| Service element | XAPI function      | Description                                                                                                                                                                                                           |
+|-----------------|--------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Data Request    | <i>x_snddata()</i> | The Data Request is passed to the provider to transmit asynchronous data.<br><br>– not applicable for AV Data:<br>The service parameter X_PHC_P_DATA_TYPE is used to specify the type of data passed to the provider. |
+| Data Indication | <i>x_rcvdata()</i> | The Data Indication is generated by the provider to indicate received data.<br><br>– not applicable for AV Data:<br>The service parameter X_PHC_P_DATA_TYPE specifies the type of data received by the provider.      |
+
+###### I.5.7.3.3.2 Service parameter
+
+Table I.5-51 specifies the parameter of the Data Transfer service.
+
+**Table I.5-51/T.180 – Parameter of the Data Transfer service**
+
+| Parameter         | Data Transfer service |            |
+|-------------------|-----------------------|------------|
+|                   | Request               | Indication |
+| X_PHC_P_DATA_TYPE | M                     | M          |
+
+##### I.5.7.3.3 Service parameter description
+
+Table I.5-52 describes the parameter for the Data Transfer service.
+
+**Table I.5-52/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                    |
+|----------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_PHC_P_DATA_TYPE                                                                                                                                                                                                                                                                                                  |
+| Type of value  | long                                                                                                                                                                                                                                                                                                               |
+| Legal values   | X_PHC_PV_LSD_DATA<br>X_PHC_PV_HSD_DATA<br>X_PHC_PV_MLP_DATA                                                                                                                                                                                                                                                        |
+| Default value  | none                                                                                                                                                                                                                                                                                                               |
+| Description    | This parameter is used to specify the type of data sent or received by the service provider. The following values for the service parameter X_PHC_P_DATA_TYPE are defined:<br><br>X_PHC_PV_LSD_DATA      low-speed data;<br>X_PHC_PV_HSD_DATA      high-speed data;<br>X_PHC_PV_MLP_DATA      multilayer protocol. |
+
+##### I.5.7.3.4 Control and Indication service
+
+The Control and Indication (C&I) service enables the application to transmit commands and indications to the remote communication partner and to receive commands and indications sent by the remote partner. The service can be used at any time during a communication after the mode initialization procedure has been completed, i.e. after an X\_PHC\_SP\_INIT\_COMPL has been received.
+
+The C&I service provides the basic commands and indications defined in Recommendation H.230. They are classified into four groups:
+
+- 1) C&I related to audio;
+- 2) C&I related to video;
+- 3) C&I for maintenance purposes; and
+- 4) C&I related to simple multipoint conferences not using MLP.
+
+Beside this, the C&I service provides some means to transmit and receive non-standard commands according to Recommendation H.221.
+
+Recommendations H.242 and H.243 define some procedures to be followed in establishment and during an audiovisual communication. Recommendation H.242 deals with the communication of two AV terminals, while Recommendation H.243 concerns conference calls of three or more AV terminals and the communication between the MCU (Multipoint Control Unit) and an AV terminal. In order to provide interoperability with other AV terminals and communication equipment, the application should obey the rules given in these Recommendations.
+
+###### I.5.7.3.4.1 Service description
+
+The **transmit C&I request** can be used by either terminal at any time after successful mode initialization (reception of X\_PHC\_SP\_INIT\_COMPL) to transmit a single command or a sequence of commands within the BAS to the remote terminal. The BAS is accessible only if operating in a framed mode. No automatic frame reinstatement is provided. A transmit C&I request will fail if the I-channel is not synchronized at the time the transmission is requested. An error indication primitive with cause code CC\_OTHER and diagnostic X\_PHC\_DC\_UNSYNC is generated by the service
+
+provider and an ERROR event occurs at the service endpoint. The application has to call *x\_rcverror()* to consume the event and retrieve the error indication. To avoid this failure, the application should check the current synchronization state of the I-channel before a C&I transmission is requested. If transmission is currently unframed, the application has to switch to a framed mode prior to the C&I transmit request. (The parameter X\_PHC\_P\_TMOD\_SYNC of mode switch indications and confirmations shows the current synchronization state in transmission direction.)
+
+The service provider generates a **transmit C&I confirmation** as response to a previous transmit C&I request. This confirmation has only local meaning and is used for flow control purposes. It indicates that transmission of the command or command sequence on the BAS completed and the BAS is now free again for other requests. The confirmation does not imply that the remote terminal understood or accepted the command. Note that due to the effective bandwidth of the BAS (0.4 kbit/s or 50 bytes per second), the transmission time for a longer command sequence will soon count in seconds, which is a really long time in modern computing.
+
+The transmit C&I request requires the BAS for transmission and thus has to be coordinated with the other BAS requests (see I.5.7.3 above). No transmit C&I request may be submitted while a transmit C&I-, a mode switch-, an add line-, or a capability exchange confirmation is outstanding.
+
+A **transmit C&I indication** is generated by the service provider to indicate received commands or indications to the application. It depends on the received command whether an action is required by the application or whether the service provider or Codec already took the appropriate action and the command is indicated for information only.
+
+The service elements and their corresponding XAPI functions needed for Control and Indication are described in Table I.5-53.
+
+**Table I.5-53/T.180 – Service elements and their corresponding XAPI functions for Control and Indication**
+
+| Service element           | XAPI function | Service element identifier | Description                                                                                                                                                                                                                                                                                  |
+|---------------------------|---------------|----------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Transmit C&I Request      | x_sndsp()     | X_PHC_SP_TRA_CAI_Q         | The Transmit C&I Request primitive is passed to the provider to send one or more commands or indications to the remote terminal. The commands and indications to be transmitted are specified as service parameters.<br>X_PHC_SP_TRA_CAI_Q is the identifier of the service primitive.       |
+| Transmit C&I Confirmation | x_rcvsp()     | X_PHC_SP_TRA_CAI_C         | The Transmit C&I Confirmation primitive is generated by the service provider as acknowledgment of a previous transmit C&I request. It indicates that transmission completed. There are no service parameters defined.<br>X_PHC_SP_TRA_CAI_C is the identifier of the service primitive.      |
+| Received C&I Indication   | x_rcvsp()     | X_PHC_SP_REC_CAI_I         | The Received C&I Indication primitive is passed to the application to indicate the reception of a command or indication from the communication partner. The service parameters specify the received command or indication.<br>X_PHC_SP_REC_CAI_I is the identifier of the service primitive. |
+
+###### **I.5.7.3.4.2 Service parameters**
+
+Table I.5-54 specifies the parameters of the Control and Indication service. Each parameter corresponds to one command or indication. In a transmit C&I request, multiple parameters (commands) may be specified. The commands are transmitted one after another in the sequence of the parameters in the parameter buffer.
+
+An X\_PHC\_SP\_REC\_CAI\_I primitive always returns only one received command or indication to the application.
+
+NOTE 1 – There are C&I parameters that have no value. These "no-value-parameters" represent simple commands like, Video Command "Freeze Picture". If the parameter is specified in a transmit C&I request, the corresponding command is sent to the remote partner. And, vice versa, if the parameter is returned by a received C&I indication, the corresponding command or indication has been received from the remote terminal (or MCU).
+
+NOTE 2 – The service provider may act in one of the following ways upon the reception of a C&I:
+
+- 1) The requested (appropriate) action is taken and no indication is passed to the application. Some commands that are handled by the Codec internally are treated in this way. A received video command "Freeze Picture Request", for example, is handled internally and the user will note the result: a frozen picture on the screen. It is not necessary to inform the application program.
+- 2) The requested (appropriate) action is taken and an X\_PHC\_SP\_REC\_CAI\_I is passed to the application program for information. Some commands that are handled by the Codec internally and/or require immediate reaction are treated in this way. A received loopback command "Video Loop Request", for example, is handled internally but maybe it would a good idea to inform the user that video loopback is active and thus the own picture is not transmitted to the remote terminal any more.
+- 3) No action is taken and the received command or indication is passed on to the application program with an X\_PHC\_SP\_REC\_CAI\_I. It depends on the C&I whether the application has to act on this indication or not. A received "Multipoint Indication Visualization" (MIV), for example, is simply passed on by the service provider. Such a MIV is transmitted by an MCU to indicate to a terminal that its video signal is being seen by the other terminals. It is up to the application to use this information and, e.g. put on a little red light to inform the person in front of the camera.
+
+**Table I.5-54/T.180 – Parameters of the Control and Indication service**
+
+| Parameter           | Control and Indication service |            |
+|---------------------|--------------------------------|------------|
+|                     | Request                        | Indication |
+| X_PHC_P_H230_AIM    | U                              | C          |
+| X_PHC_P_H230_AIA    | U                              | C          |
+| X_PHC_P_H230_VCF    | U                              |            |
+| X_PHC_P_H230_VCU    | U                              |            |
+| X_PHC_P_H230_VIS    | U                              | C          |
+| X_PHC_P_H230_VIA    | U                              | C          |
+| X_PHC_P_H230_VIA2   | U                              | C          |
+| X_PHC_P_H230_VIA3   | U                              | C          |
+| X_PHC_P_H230_VIR    | U                              | C          |
+| X_PHC_P_H230_LCA    | U                              | C          |
+| X_PHC_P_H230_LCV    | U                              | C          |
+| X_PHC_P_H230_LCD    | U                              | C          |
+| X_PHC_P_H230_LCO    | U                              | C          |
+| X_PHC_P_H230_MCV    | U                              |            |
+| X_PHC_P_H230_MIV    |                                | C          |
+| X_PHC_P_H230_MCC    |                                | C          |
+| X_PHC_P_H230_CN_MCC |                                | C          |
+
+**Table I.5-54/T.180 – Parameters of the Control and Indication service (concluded)**
+
+| Parameter           | Control and Indication service |            |
+|---------------------|--------------------------------|------------|
+|                     | Request                        | Indication |
+| X_PHC_P_H230_MCS    |                                | C          |
+| X_PHC_P_H230_MCN    |                                | C          |
+| X_PHC_P_H230_MIZ    |                                | C          |
+| X_PHC_P_H230_CN_MIZ |                                | C          |
+| X_PHC_P_H230_MIS    |                                | C          |
+| X_PHC_P_H230_CN_MIS |                                | C          |
+| X_PHC_P_CMD_NONSTD  | U                              | C          |
+
+Tables I.5-55 to I.5-78 describe the parameters for the Control and Indication Service.
+
+###### I.5.7.3.4.3 C&I service parameters related to audio
+
+**Table I.5-55/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
+|----------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_PHC_P_H230_AIM                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
+| Type of value  | no value                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
+| Legal values   | not applicable                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
+| Default value  | not applicable                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
+| Description    | <p>This parameter is returned in a receive C&amp;I indication if an Audio Indicate "Muted" (<b>AIM</b>) symbol has been received. The symbol is used to indicate that the content of the audio channel does not represent a normal audio signal. The audio encoder may be without audio input or an electronically-generated tone may have been substituted.</p> <p>The service provider does not take any action upon receipt of AIM.</p> <p>The parameter may be specified in a transmit C&amp;I request to disconnect the audio source (microphone) from the input of the audio encoder and send an AIM to the remote terminal.</p> |
+
+**Table I.5-56/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
+|----------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_PHC_P_H230_AIA                                                                                                                                                                                                                                                                                                                                                                                                                                      |
+| Type of value  | no value                                                                                                                                                                                                                                                                                                                                                                                                                                              |
+| Legal values   | not applicable                                                                                                                                                                                                                                                                                                                                                                                                                                        |
+| Default value  | not applicable                                                                                                                                                                                                                                                                                                                                                                                                                                        |
+| Description    | <p>This parameter is returned in a receive C&amp;I indication if an Audio Indicate "Active" (<b>AIA</b>) symbol has been received. It is the complementary to AIM (see above).</p> <p>The service provider does not take any action upon receipt of AIA.</p> <p>The parameter may be specified in a transmit C&amp;I request to reconnect the audio source (microphone) to the input of the audio encoder and send an AIA to the remote terminal.</p> |
+
+###### I.5.7.3.4.4 C&I service parameters related to video
+
+**Table I.5-57/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                    |
+|----------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_PHC_P_H230_VCF                                                                                                                                                                                                                                                                                   |
+| Type of value  | no value                                                                                                                                                                                                                                                                                           |
+| Legal values   | not applicable                                                                                                                                                                                                                                                                                     |
+| Default value  | not applicable                                                                                                                                                                                                                                                                                     |
+| Description    | <p>This parameter may be specified in a transmit C&amp;I request to send a Video Command "Freeze Picture Request" (<b>VCF</b>) symbol to the remote terminal. See Recommendation H230 for the meaning of VCF.</p> <p>The service provider does not indicate a received VCF to the application.</p> |
+
+**Table I.5-58/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                 |
+|----------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_PHC_P_H230_VCU                                                                                                                                                                                                                                                                                |
+| Type of value  | no value                                                                                                                                                                                                                                                                                        |
+| Legal values   | not applicable                                                                                                                                                                                                                                                                                  |
+| Default value  | not applicable                                                                                                                                                                                                                                                                                  |
+| Description    | <p>This parameter may be specified in a transmit C&amp;I request to send a Video Command "Fast Update Request" (<b>VCU</b>) symbol to the remote terminal. See Recommendation H230 for the meaning of VCU.</p> <p>The service provider does not indicate a received VCU to the application.</p> |
+
+**Table I.5-59/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
+|----------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_PHC_P_H230_VIS                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
+| Type of value  | no value                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
+| Legal values   | not applicable                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
+| Default value  | not applicable                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
+| Description    | <p>This parameter is returned in a receive C&amp;I indication if a Video Indicate "Suppressed" (<b>VIS</b>) symbol has been received. It is used to indicate that the content of the video does not represent a normal camera image. The video encoder may be without video input or an electronically-generated pattern may have been substituted.</p> <p>The service provider does not take any action upon receipt of VIS.</p> <p>The parameter may be specified in a transmit C&amp;I request to disconnect the current video source from the input of the video encoder and send a VIS to the remote terminal.</p> |
+
+**Table I.5-60/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
+|----------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_PHC_P_H230_VIA                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
+| Type of value  | no value                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
+| Legal values   | not applicable                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
+| Default value  | not applicable                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
+| Description    | <p>This parameter is returned in a receive C&amp;I indication if a Video Indicate "Active" (<b>VIA</b>) symbol has been received. It is the complementary to VIS (see above). If there are more video sources to be distinguished, VIA indicates that "video No. 1" is now active.</p> <p>The service provider does not take any action upon receipt of VIA.</p> <p>The parameter may be specified in a transmit C&amp;I request to connect video source No. 1 (usually the camera) to the input of the video encoder and send a VIA to the remote terminal.</p> |
+
+**Table I.5-61/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
+|----------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_PHC_P_H230_VIA2                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
+| Type of value  | no value                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
+| Legal values   | not applicable                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
+| Default value  | not applicable                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
+| Description    | <p>This parameter is returned in a receive C&amp;I indication if a Video Indicate "Source 2 Active" (<b>VIA2</b>) symbol has been received. It is equivalent to VIA, but designating "video No. 2" the as source.</p> <p>The service provider does not take any action upon receipt of VIA2.</p> <p>The parameter may be specified in a transmit C&amp;I request to connect video source No. 2 to the input of the video encoder and send a VIA2 to the remote terminal.</p> |
+
+**Table I.5-62/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
+|----------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_PHC_P_H230_VIA3                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
+| Type of value  | no value                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
+| Legal values   | not applicable                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
+| Default value  | not applicable                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
+| Description    | <p>This parameter is returned in a receive C&amp;I indication if a Video Indicate "Source 3 Active" (<b>VIA3</b>) symbol has been received. It is equivalent to VIA, but designating "video No. 3" as the source.</p> <p>The service provider does not take any action upon receipt of VIA3.</p> <p>The parameter may be specified in a transmit C&amp;I request to connect video source No. 3 to the input of the video encoder and send a VIA3 to the remote terminal.</p> |
+
+**Table I.5-63/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
+|----------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_PHC_P_H230_VIR                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
+| Type of value  | no value                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
+| Legal values   | not applicable                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
+| Default value  | not applicable                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
+| Description    | <p>This parameter is returned in a receive C&amp;I indication if a Video Indicate "Ready to Activate" (<b>VIR</b>) symbol has been received.</p> <p>The service provider does not take any action upon receipt of VIR.</p> <p>The parameter may be specified in a transmit C&amp;I request to send a VIR to the remote terminal. The symbol is transmitted by a terminal whose user has decided not to send video unless she/he will also receive video from the other end.</p> |
+
+###### I.5.7.3.4.5 C&I service parameters for maintenance purposes
+
+**Table I.5-64/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                         |
+|----------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_PHC_P_H230_LCA                                                                                                                                                                                                                                                                                                                                                                                        |
+| Type of value  | no value                                                                                                                                                                                                                                                                                                                                                                                                |
+| Legal values   | not applicable                                                                                                                                                                                                                                                                                                                                                                                          |
+| Default value  | not applicable                                                                                                                                                                                                                                                                                                                                                                                          |
+| Description    | <p>This parameter is returned in a receive C&amp;I indication if a Loopback Command "Audio Loop Request" (<b>LCA</b>) symbol has been received.</p> <p>The service provider (Codec) acts on this command and connects the output of the audio decoder to the input of the audio encoder.</p> <p>The parameter may be specified in a transmit C&amp;I request to send an LCA to the remote terminal.</p> |
+
+**Table I.5-65/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                         |
+|----------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_PHC_P_H230_LCV                                                                                                                                                                                                                                                                                                                                                                                        |
+| Type of value  | no value                                                                                                                                                                                                                                                                                                                                                                                                |
+| Legal values   | not applicable                                                                                                                                                                                                                                                                                                                                                                                          |
+| Default value  | not applicable                                                                                                                                                                                                                                                                                                                                                                                          |
+| Description    | <p>This parameter is returned in a receive C&amp;I indication if a Loopback Command "Video Loop Request" (<b>LCV</b>) symbol has been received.</p> <p>The service provider (Codec) acts on this command and connects the output of the video decoder to the input of the video encoder.</p> <p>The parameter may be specified in a transmit C&amp;I request to send an LCV to the remote terminal.</p> |
+
+**Table I.5-66/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
+|----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_PHC_P_H230_LCD                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
+| Type of value  | no value                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
+| Legal values   | not applicable                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
+| Default value  | not applicable                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
+| Description    | <p>This parameter is returned in a receive C&amp;I indication if a Loopback Command "Digital Loop Request" (<b>LCD</b>) symbol has been received.</p> <p>The service provider (Codec) acts on this command and disconnects the output of the multiplexer from the outgoing path, replacing it with the input to the demultiplexer. In the case of multiple B or H<sub>0</sub> connections, loopback is activated in each connection.</p> <p>The parameter may be specified in a transmit C&amp;I request to send an LCD to the remote terminal.</p> |
+
+**Table I.5-67/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                                                       |
+|----------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_PHC_P_H230_LCO                                                                                                                                                                                                                                                                                                                                                                                                                      |
+| Type of value  | no value                                                                                                                                                                                                                                                                                                                                                                                                                              |
+| Legal values   | not applicable                                                                                                                                                                                                                                                                                                                                                                                                                        |
+| Default value  | not applicable                                                                                                                                                                                                                                                                                                                                                                                                                        |
+| Description    | <p>This parameter is returned in a receive C&amp;I indication if a Loopback Command "Loops Off" (<b>LCO</b>) symbol has been received.</p> <p>The service provider (Codec) acts on this command and disconnects all currently active loops and restores data, audio, and video signal paths to their normal condition.</p> <p>The parameter may be specified in a transmit C&amp;I request to send an LCO to the remote terminal.</p> |
+
+###### **I.5.7.3.4.6 C&I service parameters related to multipoint conferences**
+
+**Table I.5-68/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                          |
+|----------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_PHC_P_H230_MCV                                                                                                                                                                                                                                                                                                         |
+| Type of value  | no value                                                                                                                                                                                                                                                                                                                 |
+| Legal values   | not applicable                                                                                                                                                                                                                                                                                                           |
+| Default value  | not applicable                                                                                                                                                                                                                                                                                                           |
+| Description    | <p>The parameter may be specified in a transmit C&amp;I request to send a Multipoint Command "Visualization Forcing" (<b>MCV</b>).</p> <p>The symbol is transmitted by a terminal to force an associated MCU to broadcast the own video signal. (Used, e.g. to transmit the picture of the chairman or another VIP.)</p> |
+
+**Table I.5-69/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                   |
+|----------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_PHC_P_H230_MIV                                                                                                                                                                                                                                                                                                                                                                                  |
+| Type of value  | no value                                                                                                                                                                                                                                                                                                                                                                                          |
+| Legal values   | not applicable                                                                                                                                                                                                                                                                                                                                                                                    |
+| Default value  | not applicable                                                                                                                                                                                                                                                                                                                                                                                    |
+| Description    | <p>This parameter is returned in a receive C&amp;I indication if a Multipoint Indication "Visualization" (<b>MIV</b>) symbol has been received.</p> <p>The symbol is transmitted by an MCU to indicate to a terminal that its video signal is being seen by the other terminals. Also known as "On-Air" indication.</p> <p>The service provider does not take any action upon receipt of MIV.</p> |
+
+**Table I.5-70/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
+|----------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_PHC_P_H230_MCC                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
+| Type of value  | no value                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
+| Legal values   | not applicable                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
+| Default value  | not applicable                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
+| Description    | <p>This parameter is returned in a receive C&amp;I indication if a Multipoint Command "Conference" (<b>MCC</b>) symbol has been received.</p> <p>The symbol is transmitted by an MCU to a terminal to force a symmetrical communication mode. The terminal receiving MCC must make its outgoing transfer rate equal to its incoming transfer rate and its outgoing audio rate equal to its incoming audio rate.</p> <p>If necessary, the service provider switches the used communication mode as required and informs the application with a mode switch indication.</p> <p>For further study: How to handle mode switch requests from the application while MCC is active? a) Ignore them, b) let them fail, c) handle as usual, d) restrict them to mode categories other than transfer and audio rate?</p> |
+
+**Table I.5-71/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                      |
+|----------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_PHC_P_H230_CN_MCC                                                                                                                                                                                                                                                                                                  |
+| Type of value  | no value                                                                                                                                                                                                                                                                                                             |
+| Legal values   | not applicable                                                                                                                                                                                                                                                                                                       |
+| Default value  | not applicable                                                                                                                                                                                                                                                                                                       |
+| Description    | <p>This parameter is returned in a receive C&amp;I indication if a Multipoint Command "Cancel MCC" has been received.</p> <p>The symbol is transmitted by an MCU to cancel the effect of a previously sent MCC.</p> <p>The restrictions to mode switch requests which became active with the MCC are now lifted.</p> |
+
+**Table I.5-72/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
+|----------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_PHC_P_H230_MCS                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
+| Type of value  | no value                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
+| Legal values   | not applicable                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
+| Default value  | not applicable                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
+| Description    | <p>This parameter is returned in a receive C&amp;I indication if a Multipoint Command "Symmetrical Data Transmission" (<b>MCS</b>) symbol has been received.</p> <p>The symbol is transmitted by an MCU when setting up data broadcasting. On receipt, a terminal must prepare itself for data reception and insure, by mode change if necessary, that its outgoing data channel occupies the same capacity as its incoming data channel. A terminal in receipt of MCS cannot initiate data broadcasting.</p> <p>If necessary, the service provider switches the used communication mode as required and informs the application with a mode switch indication.</p> |
+
+**Table I.5-73/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
+|----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_PHC_P_H230_MCN                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
+| Type of value  | no value                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
+| Legal values   | not applicable                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
+| Default value  | not applicable                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
+| Description    | <p>This parameter is returned in a receive C&amp;I indication if a Multipoint Command "Negating MCS" (<b>MCN</b>) symbol has been received.</p> <p>The symbol is transmitted by an MCU at the completion of data broadcasting. On receipt, a terminal close any outgoing data channel which it has opened as result of a previous reception of MCS. Following the end of data reception and the receipt of MCN, a terminal is permitted to initiate data broadcasting.</p> <p>If necessary, the service provider uses the outgoing data channels as required and informs the application with a mode switch indication.</p> |
+
+**Table I.5-74/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                     |
+|----------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_PHC_P_H230_MIZ                                                                                                                                                                                                                                                                                                                                                                    |
+| Type of value  | no value                                                                                                                                                                                                                                                                                                                                                                            |
+| Legal values   | not applicable                                                                                                                                                                                                                                                                                                                                                                      |
+| Default value  | not applicable                                                                                                                                                                                                                                                                                                                                                                      |
+| Description    | <p>This parameter is returned in a receive C&amp;I indication if a Multipoint Indication "Zero-communication" (<b>MIZ</b>) symbol has been received.</p> <p>The symbol is transmitted by an MCU to a terminal for information, with the meaning that no other terminals are yet connected to the MCU.</p> <p>The service provider does not take any action upon receipt of MIZ.</p> |
+
+**Table I.5-75/T.180**
+
+|                |                                                                                                                                                                                                                                                                                    |
+|----------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_PHC_P_H230_CN_MIZ                                                                                                                                                                                                                                                                |
+| Type of value  | no value                                                                                                                                                                                                                                                                           |
+| Legal values   | not applicable                                                                                                                                                                                                                                                                     |
+| Default value  | not applicable                                                                                                                                                                                                                                                                     |
+| Description    | <p>This parameter is returned in a receive C&amp;I indication if a Multipoint Indication "Cancel MIZ" has been received.</p> <p>The symbol is transmitted by an MCU to revoke a previous MIZ.</p> <p>The service provider does not take any action upon receipt of Cancel MIZ.</p> |
+
+**Table I.5-76/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
+|----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_PHC_P_H230_MIS                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
+| Type of value  | no value                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
+| Legal values   | not applicable                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
+| Default value  | not applicable                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
+| Description    | <p>This parameter is returned in a receive C&amp;I indication if a Multipoint Indication "Secondary Status" (<b>MIS</b>) symbol has been received.</p> <p>The symbol is transmitted by an MCU to a terminal for information, with the meaning that since other terminals of higher capability are participating in the conference-call, this terminal will not necessarily receive all the signals that are sent to those other terminals (see Recommendation H.243).</p> <p>The service provider does not take any action upon receipt of MIS.</p> |
+
+**Table I.5-77/T.180**
+
+|                |                                                                                                                                                                                                                                                                                    |
+|----------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_PHC_P_H230_CN_MIS                                                                                                                                                                                                                                                                |
+| Type of value  | no value                                                                                                                                                                                                                                                                           |
+| Legal values   | not applicable                                                                                                                                                                                                                                                                     |
+| Default value  | not applicable                                                                                                                                                                                                                                                                     |
+| Description    | <p>This parameter is returned in a receive C&amp;I indication if a Multipoint Indication "Cancel MIS" has been received.</p> <p>The symbol is transmitted by an MCU to revoke a previous MIS.</p> <p>The service provider does not take any action upon receipt of Cancel MIS.</p> |
+
+###### I.5.7.3.4.7 C&I service parameters for non-standard commands
+
+Table I.5-78/T.180
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
+|----------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_PHC_P_CMD_NONSTD                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
+| Type of value  | unsigned char [ ], 5 ... 255 bytes                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
+| Legal values   | Any sequence of bytes.<br>The minimum length is 5, the maximum length is <b>X_PHC_C_MAX_NONSTD</b> (255).<br>The first 4 bytes have a special meaning, see description below.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
+| Default value  | none                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
+| Description    | <p>This parameter may be specified in a transmit C&amp;I request to send a non-CCITT command message to the remote terminal. The first two bytes of the value specify a country code, and the next two bytes specify a terminal manufacturer code. The meaning of all following bytes is defined by the manufacturer.</p> <p>[byte 0] Country code according to Recommendation T.35<br/>[byte 1] Country code<br/>[bytes 2,3] Manufacturer Code (e.g. Company 4711)<br/>[bytes 5-n] Manufacturer specific</p> <p>The second byte of the country code and the manufacturer code are assigned nationally.</p> <p>This parameter is returned in a receive C&amp;I indication if a non-CCITT command message has been received. The first four bytes have the same meaning as defined above. The service provider takes no action upon receipt of a non-CCITT command message and does not check country and/or manufacturer code. All bytes are passed on as received. The <i>len</i> field specifies the length of the message.</p> <p>Note that due to the effective bandwidth of the BAS (0.4 kbit/s resp. 50 bytes per second), the transmission time for a non-standard command of maximum length will be more than 5 seconds.</p> |
+
+#### I.5.7.4 Connection Release service
+
+##### I.5.7.4.1 Service description
+
+The Connection Release service enables the XAPI user to release the AV connection in an orderly manner. It may be used by either terminal after successful mode initialization (reception of service primitive X\_PHC\_SP\_INIT\_COMPL). The "mode 0 forcing" procedure is initiated and all B-/H<sub>0</sub>-channels are released in a controlled manner as defined in Recommendation H.242. No orderly release indication (to be consumed with a *x\_relind()* calls) is defined. If an orderly connection release is initiated by the remote terminal, the local terminal will get a mode switch indication (service primitive X\_PHC\_MODE\_SWITCH\_I) as a result of the mode 0 forcing. After this, the disconnection of the initial channel will be indicated to the application with a disconnect indication (see below).
+
+The elements of the Connection Release service and the corresponding XAPI functions are described in Table I.5-79.
+
+**Table I.5-79/T.180 – Service elements and their corresponding XAPI functions  
+for Connection Release**
+
+| Service element      | XAPI Function | Description                                                                                                                                                                                           |
+|----------------------|---------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Release Request      | x_relreq()    | The Release Request is passed to the provider to request an orderly AV connection release.                                                                                                            |
+| Release Confirmation | x_relconf()   | The Release Confirmation is generated by the provider as positive confirmation of an orderly AV Connection release.                                                                                   |
+| End Indication       | x_rcvend()    | The End Indication is generated by the provider to indicate that the service provider is ready to establish a new connection. In addition it contains some information about the released connection. |
+
+##### **I.5.7.4.2 Service parameters**
+
+Table I.5-80 specifies the parameters of the Connection Release service:
+
+**Table I.5-80/T.180**
+
+| Parameter       | Connection Release service |              |                |
+|-----------------|----------------------------|--------------|----------------|
+|                 | Request                    | Confirmation | End Indication |
+| X_P_CONN_TIME   |                            |              | M              |
+| X_P_DISC_TIME   |                            |              | M              |
+| X_P_CHARGE      |                            |              | C              |
+| X_P_DISC_REASON |                            |              | C              |
+
+##### **I.5.7.4.3 Service parameter descriptions**
+
+Tables I.5-81 to I.5-84 describe the parameters for the Connection Release service.
+
+**Table I.5-81/T.180**
+
+|                |                                                                           |
+|----------------|---------------------------------------------------------------------------|
+| Parameter name | X_P_CONN_TIME                                                             |
+| Type of value  | unsigned long                                                             |
+| Legal values   | the time in seconds since 01.01.1970 00:00:00 GMT                         |
+| Default value  | none                                                                      |
+| Description    | This parameter contains the time of physical connection of the I-channel. |
+
+**Table I.5-82/T.180**
+
+|                |                                                                                                                                                                                  |
+|----------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_P_DISC_TIME                                                                                                                                                                    |
+| Type of value  | unsigned long                                                                                                                                                                    |
+| Legal values   | the time in seconds since 01.01.1970 00:00:00 GMT                                                                                                                                |
+| Default value  | none                                                                                                                                                                             |
+| Description    | This parameter contains the time of physical disconnection of the I-channel. If X_P_CONN_TIME and X_P_DISCON_TIME both set to zero, no physical connection could be established. |
+
+**Table I.5-83/T.180**
+
+|                |                                                                                                                                                                                                    |
+|----------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_P_CHARGE                                                                                                                                                                                         |
+| Type of value  | unsigned long                                                                                                                                                                                      |
+| Legal values   | any number                                                                                                                                                                                         |
+| Default value  | zero                                                                                                                                                                                               |
+| Description    | This parameter contains the number of charging units for the connection (including all transfer lines used). It will be present only if both network and network connection provide this facility. |
+
+**Table I.5-84/T.180**
+
+|                |                                                                                                                         |
+|----------------|-------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_P_DISC_REASON                                                                                                         |
+| Type of value  | unsigned long                                                                                                           |
+| Legal values   | The values are directly mapped from the underlying hardware. See the hardware documentation to get further information. |
+| Default value  | zero                                                                                                                    |
+| Description    | This parameter contains, if available, the reason for disconnecting the I-channel.                                      |
+
+#### **I.5.7.5 Connection Abort service**
+
+##### **I.5.7.5.1 Service description**
+
+The Connection Abort service allows either user of the AV Codec control service to disconnect all established channels at once. The mode 0 forcing procedure of Recommendation H.242 is not followed. Use of this service will cause loss of undelivered data of the data transfer service (LSD/HSD).
+
+The service elements and their corresponding XAPI functions needed for disconnection of an AV Codec connection are described in Table I.5-85.
+
+**Table I.5-85/T.180 – Service elements and their corresponding XAPI functions for Connection Abort**
+
+| Service element       | XAPI function | Description                                                                                                                                                                                                                                   |
+|-----------------------|---------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Disconnect Request    | x_snddis()    | The Disconnect Request is passed to the provider to request a disconnection.                                                                                                                                                                  |
+| Disconnect Indication | x_rcvdis()    | The Disconnect Indication is generated by the provider to indicate the release of all channels of an AV connection including the initial channel. The disconnection may be initiated by the local service provider or the remote peer entity. |
+| End Indication        | x_rcvend()    | The End Indication is generated by the provider to indicate that the endpoint is ready again to establish a new connection. In addition it contains some information about the aborted connection.                                            |
+
+##### I.5.7.5.2 Service parameters
+
+Table I.5-86 specifies the parameters of the Connection Abort service:
+
+**Table I.5-86/T.180**
+
+| Parameter       | Abort service |            |                |
+|-----------------|---------------|------------|----------------|
+|                 | Request       | Indication | End Indication |
+| X_P_CONN_TIME   |               |            | M              |
+| X_P_DISC_TIME   |               |            | M              |
+| X_P_CHARGE      |               |            |                |
+| X_P_DISC_REASON |               |            |                |
+
+##### I.5.7.5.3 Service parameter descriptions
+
+Tables I.5-87 to I.5-90 describe the parameters for the Connection Abort service.
+
+**Table I.5-87/T.180**
+
+|                |                                                                           |
+|----------------|---------------------------------------------------------------------------|
+| Parameter name | X_P_CONN_TIME                                                             |
+| Type of value  | unsigned long                                                             |
+| Legal values   | the time in seconds since 01.01.1970 00:00:00 GMT                         |
+| Default value  | none                                                                      |
+| Description    | This parameter contains the time of physical connection of the I-channel. |
+
+**Table I.5-88/T.180**
+
+|                |                                                                                                                                                                                  |
+|----------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_P_DISC_TIME                                                                                                                                                                    |
+| Type of value  | unsigned long                                                                                                                                                                    |
+| Legal values   | the time in seconds since 01.01.1970 00:00:00 GMT                                                                                                                                |
+| Default value  | none                                                                                                                                                                             |
+| Description    | This parameter contains the time of physical disconnection of the I-channel. If X_P_CONN_TIME and X_P_DISCON_TIME both set to zero, no physical connection could be established. |
+
+**Table I.5-89/T.180**
+
+|                |                                                                                                                                                                                                    |
+|----------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_P_CHARGE                                                                                                                                                                                         |
+| Type of value  | unsigned long                                                                                                                                                                                      |
+| Legal values   | any number                                                                                                                                                                                         |
+| Default value  | zero                                                                                                                                                                                               |
+| Description    | This parameter contains the number of charging units for the connection (including all transfer lines used). It will be present only if both network and network connection provide this facility. |
+
+**Table I.5-90/T.180**
+
+|                |                                                                                                                         |
+|----------------|-------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_P_DISC_REASON                                                                                                         |
+| Type of value  | unsigned long                                                                                                           |
+| Legal values   | The values are directly mapped from the underlying hardware. See the hardware documentation to get further information. |
+| Default value  | zero                                                                                                                    |
+| Description    | This parameter contains, if available, the reason for disconnecting the I-channel.                                      |
+
+#### **I.5.7.6 Local Control service**
+
+The Local Control service is based on the XAPI function *x\_sndsp()* and enables the user of the AV Codec control service to trigger local actions. The service can be used by either partner at any time after successful mode initialization. One of the defined actions is, for example, to send a picture release signal within the H.261 data to cancel a previously submitted VCF (video command freeze picture request).
+
+The elements of the Local Control service and their parameters are listed in Tables I.5-91 and I.5-92.
+
+**Table I.5-91/T.180 – Service element and their corresponding XAPI function for Local Control**
+
+| Service element       | XAPI function | Service element identifier | Description                                                                                                                                                                        |
+|-----------------------|---------------|----------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Local Control Request | x_sndsp()     | X_PHC_SP_LCTRL_Q           | The Local Control Request primitive is submitted to the provider to initiate the local action specified as service parameter. Multiple actions with one request are not supported. |
+
+**Table I.5-92/T.180 – Parameters of the Local Control**
+
+| Parameter                | Local Control service |
+|--------------------------|-----------------------|
+|                          | Request               |
+| X_PHC_P_H261CMD_SNDINTRA | U                     |
+| X_PHC_P_H261CMD_PICTREL  | U                     |
+
+##### **I.5.7.6.1 Service parameter descriptions**
+
+Tables I.5-93 and I.5-94 describe the parameters for the Local Control service.
+
+**Table I.5-93/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
+|----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_PHC_P_H261CMD_SNDINTRA                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
+| Type of value  | no value                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
+| Legal values   | not applicable                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
+| Default value  | not applicable                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
+| Description    | <p>This parameter may be specified in a local control request to initiate the sending of one intra coded frame. This action is sometimes useful if an external video switch is used to change the source of video input signals. After switching the video source, an enforced intra frame will help the remote decoder to get back on the right way.</p> <p>The general H.261 encoding mode as specified by the X_PHC_O_H261_ENCODE option is not influenced by an enforced intra frame.</p> |
+
+**Table I.5-94/T.180**
+
+|                |                                                                                                                                                                                                                                                                          |
+|----------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_PHC_P_H261CMD_PICTREL                                                                                                                                                                                                                                                  |
+| Type of value  | no value                                                                                                                                                                                                                                                                 |
+| Legal values   | not applicable                                                                                                                                                                                                                                                           |
+| Default value  | not applicable                                                                                                                                                                                                                                                           |
+| Description    | This parameter may be specified in a local control request to send a picture release signal within H.261 data to the remote terminal. On reception of picture release, the remote terminal will cancel a previously received VCF (video command freeze picture request). |
+
+#### I.5.7.7 Option management
+
+The **management of protocol options** is based on the XAPI function *x\_optmgt()*. It enables the XAPI user to set the value of a protocol option, to check a value without changing the current value, and to retrieve the current or default value. See the main part of this Recommendation for a detailed description of option management in general and the manual page of the *x\_optmgt()* function. The option management may be used in any state of the service endpoint. Protocol options have only local meaning. If a connection is established on an endpoint, changes in protocol options are not indicated to the remote partner. But the data transmission over this connection may be influenced by the current setting of some protocol options. For each protocol option, there is a default value defined in the XAPI configuration. This default is sufficient for the majority of applications and usually need not be changed.
+
+The AV Codec control service supports five groups of protocol options:
+
+- the default capability options: For each local capability parameter there is a corresponding protocol option which defines the default value for this parameter. If the parameter is not specified in a request, the value of the corresponding protocol option is used instead;
+- standard H.261 options which control the video encoding process;
+- non-standard H.261 options;
+- non-standard audio options;
+- non-standard maintenance options.
+
+The standard options have to be implemented by each concrete service provider while the non-standard options need not be present in all implementations. Sometimes it depends on the Codec hardware if an option can be implemented or not. All options have permanent scope, i.e. they are in effect for the whole lifetime of the service endpoint. The default option values are usually configured to the maximum values supported by the underlying hardware.
+
+##### I.5.7.7.1 Protocol option descriptions
+
+Tables I.5-95 to I.5-118 describe the protocol options.
+
+###### I.5.7.7.1.1 Default capability options
+
+**Table I.5-95/T.180**
+
+|               |                                                                                                                                                                                                                                                                                                              |
+|---------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Option name   | X_PHC_O_LCAP_AUDIO                                                                                                                                                                                                                                                                                           |
+| Type of value | long                                                                                                                                                                                                                                                                                                         |
+| Legal values  | X_PHC_PV_CAPNON<br>X_PHC_PV_AUDIO_711_A<br>X_PHC_PV_AUDIO_711_U<br>X_PHC_PV_AUDIO_722_64<br>X_PHC_PV_AUDIO_722_48<br>X_PHC_PV_AUDIO_16K<br>X_PHC_PV_AUDIO_ISO                                                                                                                                                |
+| Default value | The configured default value may be retrieved with the <i>x_optmgt()</i> function.                                                                                                                                                                                                                           |
+| Description   | The option defines the default value of parameter X_PHC_P_LCAP_AUDIO, which specifies the local audio reception capabilities in the connection establishment and capability exchange service. The option may take the same values as defined for the parameter. See above for a description of these values. |
+
+**Table I.5-96/T.180**
+
+|               |                                                                                                                                                                                                                                                                                                              |
+|---------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Option name   | X_PHC_O_LCAP_VIDEO                                                                                                                                                                                                                                                                                           |
+| Type of value | long                                                                                                                                                                                                                                                                                                         |
+| Legal values  | X_PHC_PV_CAPNON<br>X_PHC_PV_VIDEO_QCIF<br>X_PHC_PV_VIDEO_CIF<br>X_PHC_PV_VIDEO_PINV1<br>X_PHC_PV_VIDEO_PINV2<br>X_PHC_PV_VIDEO_PINV3<br>X_PHC_PV_VIDEO_PINV4<br>X_PHC_PV_VIDEO_IMP<br>X_PHC_PV_VIDEO_ISO<br>X_PHC_PV_VIDEO_AVISO                                                                             |
+| Default value | The configured default value may be retrieved with the <i>x_optmgmt()</i> function.                                                                                                                                                                                                                          |
+| Description   | The option defines the default value of parameter X_PHC_P_LCAP_VIDEO, which specifies the local video reception capabilities in the connection establishment and capability exchange service. The option may take the same values as defined for the parameter. See above for a description of these values. |
+
+**Table I.5-97/T.180**
+
+|               |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
+|---------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Option name   | X_PHC_O_LCAP_DATA                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
+| Type of value | long                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
+| Legal values  | X_PHC_PV_CAPNON<br>X_PHC_PV_DATA_VAR<br>X_PHC_PV_DATA_300                      X_PHC_PV_DATA_1200<br>X_PHC_PV_DATA_4800                    X_PHC_PV_DATA_6400<br>X_PHC_PV_DATA_8000                    X_PHC_PV_DATA_9600<br>X_PHC_PV_DATA_14400                   X_PHC_PV_DATA_16000<br>X_PHC_PV_DATA_24000                   X_PHC_PV_DATA_32000<br>X_PHC_PV_DATA_40000                   X_PHC_PV_DATA_48000<br>X_PHC_PV_DATA_56000                   X_PHC_PV_DATA_62400<br>X_PHC_PV_DATA_64000<br>X_PHC_PV_DATA_MLP4000    X_PHC_PV_DATA_MLP6400<br>X_PHC_PV_DATA_VARMLP |
+| Default value | The configured default value may be retrieved with the <i>x_optmgmt()</i> function.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
+| Description   | The option defines the default value of parameter X_PHC_P_LCAP_DATA, which specifies the local LSD and MLP reception capabilities in the connection establishment and capability exchange service. The option may take the same values as defined for the parameter. See above for a description of these values.                                                                                                                                                                                                                                                              |
+
+**Table I.5-98/T.180**
+
+|               |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
+|---------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Option name   | X_PHC_O_LCAP_HDATA                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
+| Type of value | long                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
+| Legal values  | X_PHC_PV_CAPNON<br>X_PHC_PV_HDATA_64                      X_PHC_PV_HDATA_128<br>X_PHC_PV_HDATA_192                   X_PHC_PV_HDATA_256<br>X_PHC_PV_HDATA_320                   X_PHC_PV_HDATA_384<br>X_PHC_PV_HDATA_512                   X_PHC_PV_HDATA_768<br>X_PHC_PV_HDATA_1152                  X_PHC_PV_HDATA_1536<br>X_PHC_PV_HDATA_VAR<br>X_PHC_PV_HDATA_MLP62                X_PHC_PV_HDATA_MLP64<br>X_PHC_PV_HDATA_MLP128               X_PHC_PV_HDATA_MLP192<br>X_PHC_PV_HDATA_MLP256               X_PHC_PV_HDATA_MLP320<br>X_PHC_PV_HDATA_MLP384<br>X_PHC_PV_HDATA_VARMLP |
+| Default value | The configured default value may be retrieved with the <i>x_optmgmt()</i> function.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
+| Description   | The option defines the default value of parameter X_PHC_P_LCAP_HDATA, which specifies the local HSD and HMLP reception capabilities in the connection establishment and capability exchange service. The option may take the same values as defined for the parameter. See above for a description of these values.                                                                                                                                                                                                                                                                     |
+
+**Table I.5-99/T.180**
+
+|               |                                                                                                                                                                                                                                                                                                             |
+|---------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Option name   | X_PHC_O_LCAP_TFRATE                                                                                                                                                                                                                                                                                         |
+| Type of value | long                                                                                                                                                                                                                                                                                                        |
+| Legal values  | X_PHC_PV_CAPNON<br>X_PHC_PV_TFRATE_128<br>X_PHC_PV_TFRATE_192<br>X_PHC_PV_TFRATE_256<br>X_PHC_PV_TFRATE_512<br>X_PHC_PV_TFRATE_768<br>X_PHC_PV_TFRATE_1152<br>X_PHC_PV_TFRATE_1472                                                                                                                          |
+| Default value | The configured default value may be retrieved with the <i>x_optmgmt()</i> function.                                                                                                                                                                                                                         |
+| Description   | The option defines the default value of parameter X_PHC_P_LCAP_TFRATE, which specifies the local transfer rate capabilities in the connection establishment and capability exchange service. The option may take the same values as defined for the parameter. See above for a description of these values. |
+
+**Table I.5-100/T.180**
+
+|               |                                                                                                                                                                                                                                                                                                               |
+|---------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Option name   | X_PHC_O_LCAP_TFLINES                                                                                                                                                                                                                                                                                          |
+| Type of value | long                                                                                                                                                                                                                                                                                                          |
+| Legal values  | X_PHC_PV_TFLINES_1B<br>X_PHC_PV_TFLINES_2B<br>X_PHC_PV_TFLINES_3B<br>X_PHC_PV_TFLINES_4B<br>X_PHC_PV_TFLINES_5B<br>X_PHC_PV_TFLINES_6B<br>X_PHC_PV_TFLINES_1H<br>X_PHC_PV_TFLINES_2H<br>X_PHC_PV_TFLINES_3H<br>X_PHC_PV_TFLINES_4H<br>X_PHC_PV_TFLINES_5H<br>X_PHC_PV_TFLINES_H11<br>X_PHC_PV_TFLINES_H12     |
+| Default value | The configured default value may be retrieved with the <i>x_optmgmt()</i> function.                                                                                                                                                                                                                           |
+| Description   | The option defines the default value of parameter X_PHC_P_LCAP_TFLINES, which specifies the local transfer lines capabilities in the connection establishment and capability exchange service. The option may take the same values as defined for the parameter. See above for a description of these values. |
+
+**Table I.5-101/T.180**
+
+|               |                                                                                                                                                                                                                                                                                                            |
+|---------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Option name   | X_PHC_O_LCAP_MISC                                                                                                                                                                                                                                                                                          |
+| Type of value | long                                                                                                                                                                                                                                                                                                       |
+| Legal values  | X_PHC_PV_CAPNON<br>X_PHC_PV_MISC_ENCR<br>X_PHC_PV_MISC_ESC<br>X_PHC_PV_MISC_MBE<br>X_PHC_PV_MISC_RESTRICT<br>X_PHC_PV_MISC_6BHCOMP                                                                                                                                                                         |
+| Default value | The configured default value may be retrieved with the <i>x_optmgmt()</i> function.                                                                                                                                                                                                                        |
+| Description   | The option defines the default value of parameter X_PHC_P_LCAP_MISC, which specifies some local miscellaneous capabilities in the connection establishment and capability exchange service. The option may take the same values as defined for the parameter. See above for a description of these values. |
+
+**Table I.5-102/T.180**
+
+|               |                                                                                                                                                                                                                                                                                                                                      |
+|---------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Option name   | X_PHC_O_LCAP_DATAPPL                                                                                                                                                                                                                                                                                                                 |
+| Type of value | long                                                                                                                                                                                                                                                                                                                                 |
+| Legal values  | X_PHC_PV_CAPNON<br>X_PHC_PV_APPL_STILLPIC_LSD<br>X_PHC_PV_APPL_STILLPIC_HSD<br>X_PHC_PV_APPL_STILLPIC_SPATIAL<br>X_PHC_PV_APPL_STILLPIC_PROG<br>X_PHC_PV_APPL_STILLPIC_ARITH<br>X_PHC_PV_APPL_STILLIMAGE<br>X_PHC_PV_APPL_CURSORDATA<br>X_PHC_PV_APPL_FAX3<br>X_PHC_PV_APPL_FAX4<br>X_PHC_PV_APPL_V120_LSD<br>X_PHC_PV_APPL_V120_HSD |
+| Default value | The configured default value may be retrieved with the <i>x_optmgmt()</i> function.                                                                                                                                                                                                                                                  |
+| Description   | The option defines the default value of parameter X_PHC_P_LCAP_DATAPPL, which specifies the local data application capabilities in the connection establishment and capability exchange service. The option may take the same values as defined for the parameter. See above for a description of these values.                      |
+
+###### **I.5.7.7.1.2 Standard H.261 options**
+
+**Table I.5-103/T.180**
+
+|               |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
+|---------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Option name   | X_PHC_O_H261_ENCODE                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
+| Type of value | long                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
+| Legal values  | X_PHC_OV_H261_SIMPLE<br>X_PHC_OV_H261_CIF<br>X_PHC_OV_H261_INTER<br>X_PHC_OV_H261_MOTNEST<br>X_PHC_OV_H261_LOOPFILTER                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
+| Default value | The configured default value may be retrieved with the <i>x_optmgmt()</i> function.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
+| Description   | <p>This option controls the H.261 video encoding. A value of X_PHC_OV_H261_SIMPLE specifies the simplest possible encoding, intra frames only in QCIF format. The other defined values each control one additional encoding feature that may be enabled by setting this value. To enable more than one feature, the corresponding values have to be combined with the bit-wise OR operator.</p> <p>X_PHC_OV_H261_CIF                      Use CIF instead of QCIF;<br/>X_PHC_OV_H261_INTER                  Use intra and inter frames;<br/>X_PHC_OV_H261_MOTNEST              Use intra and inter frames and motion estimation;<br/>X_PHC_OV_H261_LOOPFILTER          Switch the loop filter on.</p> <p>The values X_PHC_OV_H261_INTER and X_PHC_OV_H261_MOTNEST must not be specified together.</p> <p>The option is not an absolute requirement. The specified value may be diminished by the service provider if the requested feature is not supported by the Codec hardware.</p> |
+
+**Table I.5-104/T.180**
+
+|               |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
+|---------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Option name   | X_PHC_O_H261_CODERPINV                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
+| Type of value | long                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
+| Legal values  | 1 ... 100                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
+| Default value | The configured default value may be retrieved with the <i>x_optmgmt()</i> function.                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
+| Description   | This option controls the minimum picture interval used in H.261 video encoding. The interval is not specified as absolute value but relative to the maximum speed supported by the Codec hardware. The option value specifies the percentage of the maximum speed to be used in encoding. A value of 50, for example, tells the Codec to work as fast as possible, and a value of 100 means "full speed ahead". Note that a decreased picture interval usually results in improved picture quality because more data can be transmitted for one picture. |
+
+**Table I.5-105/T.180**
+
+|               |                                                                                                                                                                                                                       |
+|---------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Option name   | X_PHC_O_H261_AUDIODELAY                                                                                                                                                                                               |
+| Type of value | long                                                                                                                                                                                                                  |
+| Legal values  | 0 ... 1000                                                                                                                                                                                                            |
+| Default value | 0                                                                                                                                                                                                                     |
+| Description   | This option controls the delay of received audio signals. It compensates the signal processing time of the video decoder to maintain lip synchronization. The option value specifies the audio delay in milliseconds. |
+
+###### I.5.7.7.1.3 Non-standard H.261 options
+
+**Table I.5-106/T.180**
+
+|               |                                                                                                                                                                                                                                                                                                                              |
+|---------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Option name   | X_PHC_O_H261NS_SOURCE                                                                                                                                                                                                                                                                                                        |
+| Type of value | long                                                                                                                                                                                                                                                                                                                         |
+| Legal values  | 1 ... 16                                                                                                                                                                                                                                                                                                                     |
+| Default value | The configured default value may be retrieved with the <i>x_optmgmt()</i> function. Usually it is set to 1.                                                                                                                                                                                                                  |
+| Description   | This option selects the source for input video signals. The option value specifies the source number. It depends on the hardware which number corresponds to which connector. If the requested source is not available or not ready, the <i>x_optmgmt()</i> call fails with NOTSUPPORT, and the current setting is retained. |
+
+**Table I.5-107/T.180**
+
+|               |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
+|---------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Option name   | X_PHC_O_H261NS_DCODFILTER                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
+| Type of value | unsigned char [] with at least one element                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
+| Legal values  | The legal values depend on the concrete service provider. See the release notes for further information. There is one option value that has to be implemented by all concrete service providers supporting this option: an array with only one element that is set to 0. This value specifies that no filter is enabled.                                                                                                                                                                                                                                                                                                                                                                       |
+| Default value | 0, no filter enabled                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
+| Description   | <p>This option selects and enables one of the present video decoding filters. It depends on the concrete service provider what kind of filters are present and with which numbers they are denoted. The first byte of the option value specifies the filter to be used. A value of 0 disables all filters. The additional elements of the option value (if there are any at all) are parameters which control the operation of the filter. The number of filter parameters and their meaning depend on the filter selected by the first element of the option value.</p> <p>This option can be used, for example, to enable a filter that smoothes the edges in the decoded video picture.</p> |
+
+**Table I.5-108/T.180**
+
+|               |                                                                                                                                                                                                                                                                                             |
+|---------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Option name   | X_PHC_O_H261NS_INTERPAR                                                                                                                                                                                                                                                                     |
+| Type of value | unsigned char [4]                                                                                                                                                                                                                                                                           |
+| Legal values  | The legal values depend on the concrete service provider. See the release notes for further information.                                                                                                                                                                                    |
+| Default value | The configured default value may be retrieved with the <i>x_optmgmt()</i> function.                                                                                                                                                                                                         |
+| Description   | <p>This option defines four parameters that control the coding of inter frames in Recommendation H.261.</p> <p>byte [0] upper boundary;<br/> byte [1] lower boundary;<br/> byte [2] fixed value;<br/> byte [3] switch on/off adaptive quantization; a value of 1 means on, 0 means off.</p> |
+
+**Table I.5-109/T.180**
+
+|               |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
+|---------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Option name   | X_PHC_O_H261NS_MOTNPAR                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
+| Type of value | unsigned char [] with at least one element                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
+| Legal values  | The legal values depend on the concrete service provider. See the release notes for further information.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
+| Default value | The configured default value may be retrieved with the <i>x_optmgmt()</i> function.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
+| Description   | <p>This option selects one of the present algorithms for motion estimation in H.261 video encoding. It depends on the concrete service provider which algorithms are present and with which numbers they are denoted. The first byte of the option value selects the algorithm by number. The additional elements of the option value (if there are any at all) are parameters used within the algorithm. The number of parameters and their meaning depend on the selected algorithm. Note that the use of motion estimation is enabled resp. disabled with the standard option H.261 encoding (X_PHC_O_H261_ENCODE).</p> |
+
+**Table I.5-110/T.180**
+
+|               |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
+|---------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Option name   | X_PHC_O_H261NS_LOOPPAR                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
+| Type of value | unsigned char [] with at least one element                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
+| Legal values  | The legal values depend on the concrete service provider. See the release notes for further information.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
+| Default value | The configured default value may be retrieved with the <i>x_optmgmt()</i> function.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
+| Description   | <p>This option selects one of the present loop filters for use in H.261 video encoding. It depends on the concrete service provider which filters are present and with which numbers they are denoted. The first byte of the option value selects the filter by number. The additional elements of the option value (if there are any at all) are parameters that control the filter. The number of parameters and their meaning depend on the selected filter.</p> <p>Note that the use of motion estimation is enabled resp. disabled with the standard option H.261 encoding (X_PHC_O_H261_ENCODE).</p> |
+
+**Table I.5-111/T.180**
+
+|               |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
+|---------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Option name   | X_PHC_O_H261NS_PREFILTER                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
+| Type of value | unsigned char [] with at least one element                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
+| Legal values  | The legal values depend on the concrete service provider. See the release notes for further information. There is one option value that has to be implemented by all concrete service providers supporting this option: an array with only one element that is set to 0. This value specifies that no filter is enabled.                                                                                                                                                                                                                                                                                                                                                                  |
+| Default value | 0, no filter enabled                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
+| Description   | <p>This option selects and enables one of the present video pre-filters. It depends on the concrete service provider what kind of filters are present and with which numbers they are denoted. The first byte of the option value specifies the filter to be used. A value of 0 disables all filters. The additional elements of the option value (if there are any at all) are parameters which control the operation of the filter. The number of filter parameters and their meaning depend on the filter selected by the first element of the option value.</p> <p>This option can be used, for example, to enable a filter that smoothes the edges in the decoded video picture.</p> |
+
+**Table I.5-112/T.180**
+
+|               |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
+|---------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Option name   | X_PHC_O_H261NS_POSTFILTER                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
+| Type of value | unsigned char [] with at least one element                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
+| Legal values  | The legal values depend on the concrete service provider. See the release notes for further information. There is one option value that has to be implemented by all concrete service providers supporting this option: an array with only one element that is set to 0. This value specifies that no filter is enabled.                                                                                                                                                                                                                                                                                                                                                                   |
+| Default value | 0, no filter enabled                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
+| Description   | <p>This option selects and enables one of the present video post filters. It depends on the concrete service provider what kind of filters are present and with which numbers they are denoted. The first byte of the option value specifies the filter to be used. A value of 0 disables all filters. The additional elements of the option value (if there are any at all) are parameters which control the operation of the filter. The number of filter parameters and their meaning depend on the filter selected by the first element of the option value.</p> <p>This option can be used, for example, to enable a filter that smoothes the edges in the decoded video picture.</p> |
+
+**Table I.5-113/T.180**
+
+|               |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
+|---------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Option name   | X_PHC_O_H261NS_OUTPUT                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
+| Type of value | long                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
+| Legal values  | X_PHC_OV_VFRMT_PAL_N<br>X_PHC_OV_VFRMT_PAL_M<br>X_PHC_OV_VFRMT_PAL_BG<br>X_PHC_OV_VFRMT_PAL_443<br>X_PHC_OV_VFRMT_SECAM<br>X_PHC_OV_VFRMT_NTSC_M<br>X_PHC_OV_VFRMT_NTSC_443<br>X_PHC_OV_VFRMT_BW                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
+| Default value | The configured default value may be retrieved with the <i>x_optmgmt()</i> function.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
+| Description   | <p>This option controls the video output format. Only one output format may be selected at one time, i.e. the defined values must not be combined.</p> X_PHC_OV_VFRMT_PAL_N                      PAL with 50 Hz;<br>X_PHC_OV_VFRMT_PAL_M                      PAL with 60 Hz;<br>X_PHC_OV_VFRMT_PAL_443                    PAL with 60 Hz;<br>X_PHC_OV_VFRMT_SECAM                      SECAM with 50 Hz;<br>X_PHC_OV_VFRMT_NTSC_M                    NTSC with 60 Hz;<br>X_PHC_OV_VFRMT_NTSC_443                   NTSC with 60 Hz;<br>X_PHC_OV_VFRMT_BW                          monochrome black and white.<br><p>The option is an absolute requirement. The <i>x_optmgmt()</i> call will fail if the requested video output format is not supported by the Codec hardware.</p> |
+
+**Table I.5-114/T.180**
+
+|               |                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
+|---------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Option name   | X_PHC_O_H261NS_INPUT                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
+| Type of value | long                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
+| Legal values  | X_PHC_OV_VFRMT_PAL_N<br>X_PHC_OV_VFRMT_PAL_M<br>X_PHC_OV_VFRMT_PAL_BG<br>X_PHC_OV_VFRMT_PAL_443<br>X_PHC_OV_VFRMT_SECAM<br>X_PHC_OV_VFRMT_NTSC_M<br>X_PHC_OV_VFRMT_NTSC_443<br>X_PHC_OV_VFRMT_BW                                                                                                                                                                                                                                                                     |
+| Default value | The configured default value may be retrieved with the <i>x_optmgt()</i> function.                                                                                                                                                                                                                                                                                                                                                                                   |
+| Description   | This option controls the video input format. Only one input format may be selected at one time, i.e. the defined values must not be combined. The option may take the same values as the output format option. The selected format applies to all video signal sources, if there is more than one available. The option is an absolute requirement. The <i>x_optmgt()</i> call will fail if the requested video input format is not supported by the Codec hardware. |
+
+###### **I.5.7.7.1.4 Non-standard audio options**
+
+**Table I.5-115/T.180**
+
+|               |                                                                                                                                                                                                                                                                                                                                               |
+|---------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Option name   | X_PHC_O_NSAUD_SOURCE                                                                                                                                                                                                                                                                                                                          |
+| Type of value | long                                                                                                                                                                                                                                                                                                                                          |
+| Legal values  | 1 ... 16                                                                                                                                                                                                                                                                                                                                      |
+| Default value | The configured default value may be retrieved with the <i>x_optmgt()</i> function. Usually it is set to 1.                                                                                                                                                                                                                                    |
+| Description   | This option selects the source for input audio signals. The option value specifies the source number. It depends on the hardware which number corresponds to which connector resp. signal level. If the requested source is not available or not ready, the <i>x_optmgt()</i> call fails with NOTSUPPORT and the current setting is retained. |
+
+**Table I.5-116/T.180**
+
+|               |                                                                                                                                                                                   |
+|---------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Option name   | X_PHC_O_NSAUD_SPEAKER                                                                                                                                                             |
+| Type of value | long                                                                                                                                                                              |
+| Legal values  | 0, 1                                                                                                                                                                              |
+| Default value | 1                                                                                                                                                                                 |
+| Description   | This option controls the local speaker. A value of 1 switches the speaker on, and a value of 0 switches it off. The setting of the audio volume is not influenced by this option. |
+
+**Table I.5-117/T.180**
+
+|               |                                                                                                              |
+|---------------|--------------------------------------------------------------------------------------------------------------|
+| Option name   | X_PHC_O_NSAUD_VOLUME                                                                                         |
+| Type of value | long                                                                                                         |
+| Legal values  | any value in the range of 0 ... 127 with 127 being loudest                                                   |
+| Default value | The configured default value may be retrieved with the <i>x_optmgmt()</i> function. Usually it is set to 63. |
+| Description   | This option controls the audio output volume.                                                                |
+
+###### **I.5.7.7.1.5 Non-standard maintenance options**
+
+**Table I.5-118/T.180**
+
+|                      |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |                  |                              |                    |                                                         |                    |                                                         |                      |                                                     |
+|----------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------|------------------------------|--------------------|---------------------------------------------------------|--------------------|---------------------------------------------------------|----------------------|-----------------------------------------------------|
+| Option name          | X_PHC_O_NSMNT_LOCAL_LOOP                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |                  |                              |                    |                                                         |                    |                                                         |                      |                                                     |
+| Type of value        | long                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |                  |                              |                    |                                                         |                    |                                                         |                      |                                                     |
+| Legal values         | X_PHC_OV_LLP_OFF<br>X_PHC_OV_LLP_AUDIO<br>X_PHC_OV_LLP_VIDEO<br>X_PHC_OV_LLP_DIGITAL                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |                  |                              |                    |                                                         |                    |                                                         |                      |                                                     |
+| Default value        | X_PHC_OV_LLP_OFF, all local loops deactivated                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |                  |                              |                    |                                                         |                    |                                                         |                      |                                                     |
+| Description          | <p>This option controls a local loop back of output signals to the input. Corresponding to the remote loops there are three local loops defined: audio, video and digital.</p> <p>For each loop there is one value defined that has to be specified as option value to activate the loop. To activate more than one loop simultaneously, the option has to be set to the bit-wise OR combination of the corresponding values. The option value X_PHC_OV_LLP_OFF deactivates all local loops</p> <table> <tr> <td>X_PHC_OV_LLP_OFF</td> <td>All local loops deactivated;</td> </tr> <tr> <td>X_PHC_OV_LLP_AUDIO</td> <td>Local loop back of audio output signals to audio input;</td> </tr> <tr> <td>X_PHC_OV_LLP_VIDEO</td> <td>Local loop back of video output signals to video input;</td> </tr> <tr> <td>X_PHC_OV_LLP_DIGITAL</td> <td>Local loop back of digital output to digital input.</td> </tr> </table> | X_PHC_OV_LLP_OFF | All local loops deactivated; | X_PHC_OV_LLP_AUDIO | Local loop back of audio output signals to audio input; | X_PHC_OV_LLP_VIDEO | Local loop back of video output signals to video input; | X_PHC_OV_LLP_DIGITAL | Local loop back of digital output to digital input. |
+| X_PHC_OV_LLP_OFF     | All local loops deactivated;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |                  |                              |                    |                                                         |                    |                                                         |                      |                                                     |
+| X_PHC_OV_LLP_AUDIO   | Local loop back of audio output signals to audio input;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |                  |                              |                    |                                                         |                    |                                                         |                      |                                                     |
+| X_PHC_OV_LLP_VIDEO   | Local loop back of video output signals to video input;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |                  |                              |                    |                                                         |                    |                                                         |                      |                                                     |
+| X_PHC_OV_LLP_DIGITAL | Local loop back of digital output to digital input.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |                  |                              |                    |                                                         |                    |                                                         |                      |                                                     |
+
+#### **I.5.7.8 Usage of XAPI functions**
+
+This subclause provides some protocol-specific remarks on the use of the XAPI functions. The functions are mentioned in alphabetical order.
+
+- |           |                                                                                                                                                                                                  |
+|-----------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| x_conconf | The <i>user_data</i> buffer in the <i>call_struct</i> is empty, as transfer of user data is not supported in the connection establishment phase.                                                 |
+| x_conind  | The <i>user_data</i> buffer in the <i>conind_struct</i> is empty, as transfer of user data is not supported in the connection establishment phase.                                               |
+| x_conreq  | The <i>user_data</i> buffer in the <i>call_struct</i> has to be empty, as transfer of user data is not supported in the connection establishment phase. Usage of the MORE flag is not supported. |
+| x_conrsp  | The <i>user_data</i> buffer in the <i>call_struct</i> has to be empty, as transfer of user data is not supported in the connection establishment phase. Usage of the MORE flag is not supported. |
+
+|                        |                                                                                                                                                                                                                                                                                                                                      |
+|------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| <code>x_bind</code>    | The address buffer <i>own_address.buf</i> of the <i>bind_struct</i> may be set to the NULL pointer. In this case the endpoint is bound to a preconfigured address. The service endpoint may be bound to multiple addresses. To achieve this, the address parameter <code>A_OUTBAND_ADR</code> may be repeated in the address buffer. |
+| <code>x_open</code>    | To create an endpoint accessing the AV Codec control service provider for ISDN, the service provider name "X_PHC_ISDN" must be used.                                                                                                                                                                                                 |
+| <code>x_relconf</code> | The <i>user_data</i> buffer in the <i>release_struct</i> is empty, as transfer of user data is not supported in the connection release phase.                                                                                                                                                                                        |
+| <code>x_relind</code>  | The AV Codec control service provider does not support passive orderly release. The XAPI event RELIND will never occur when accessing this provider. Thus the <i>x_relind()</i> consuming function need not be called by the application.                                                                                            |
+| <code>x_relreq</code>  | The <i>user_data</i> buffer in the <i>release_struct</i> has to be empty, as transfer of user data is not supported in the connection release phase. Usage of the MORE flag is not supported.                                                                                                                                        |
+| <code>x_relrsp</code>  | The AV Codec control service provider does not support passive orderly release. No release indication is defined to which the application could respond. Thus the application need not call the XAPI function <i>x_relresp()</i> .                                                                                                   |
+| <code>x_rcvdata</code> | Expedited data is not supported. This service is not applicable for AV data.                                                                                                                                                                                                                                                         |
+| <code>x_rcvdis</code>  | The <i>user_data</i> buffer in the <i>discon_struct</i> is empty, as transfer of user data is not supported by the connection abort service.                                                                                                                                                                                         |
+| <code>x_snddata</code> | Expedited data is not supported. This service is not applicable for AV data.                                                                                                                                                                                                                                                         |
+| <code>x_snddis</code>  | The <i>user_data</i> buffer in the <i>discon_struct</i> has to be empty, as transfer of user data is not supported by the connection abort service. Usage of the MORE flag is not supported.                                                                                                                                         |
+
+#### **I.5.7.9 Tables of error codes**
+
+The XAPI error-level error codes are defined in Annex B.
+
+##### **I.5.7.9.1 CC\_BADVALUE**
+
+The cause code `CC_BADVALUE` indicates that a parameter with a bad value was specified. The value of *diagnostic* then indicates the erroneous parameter identifier which has been submitted with the XAPI function call that caused the error indication.
+
+##### **I.5.7.9.2 CC\_MANDMISS**
+
+The cause code `CC_MANDMISS` indicates that a mandatory parameter is missing. The value of *diagnostic* then indicates the missing parameter identifier that caused the error indication.
+
+##### **I.5.7.9.3 CC\_BADEVENT**
+
+The cause code `CC_BADEVENT` indicates that an unknown event occurred. The value of *diagnostic* then indicates the bad event identifier which has been submitted with the XAPI function call that caused the error indication.
+
+##### **I.5.7.9.4 CC\_UNEXPECT**
+
+The cause code `CC_UNEXPECT` indicates that an event occurred which is unexpected in the current state of communication. The value of *diagnostic* then indicates the actual state identifier in which the unexpected event caused the error indication.
+
+##### **I.5.7.9.5 CC\_NOTSUPPORT**
+
+The cause code CC\_NOTSUPPORT indicates that an unsupported event occurred. The value of *diagnostic* then indicates the identifier of the unsupported event which has been submitted with the XAPI function call that caused the error indication.
+
+##### **I.5.7.9.6 CC\_OTHER**
+
+The cause code CC\_OTHER is used if none of the cause codes mentioned above applies. The following diagnostic codes are defined in the AV Codec control service:
+
+|                             |                                                                                                                                       |
+|-----------------------------|---------------------------------------------------------------------------------------------------------------------------------------|
+| <b>X_PHC_DC_UNSYNC</b>      | A transmit C&I request was submitted while the initial channel is not synchronized.                                                   |
+| <b>X_PHC_DC_NOCAPSET</b>    | No complete capability set of the remote terminal was received in a capability exchange.                                              |
+| <b>X_PHC_DC_BADCOMBI</b>    | An inconsistent combination of audio, video, and data is specified in a mode switch request.                                          |
+| <b>X_PHC_DC_CAPCONFLICT</b> | The new mode specified in a mode switch request is in conflict with the known receive and decode capabilities of the remote terminal. |
+
+## **I.6 XAPI access to the service provider for the T.120 conference control**
+
+This part of Appendix I describes an example of how the service provider can be implemented, if an application needs access to the specified service.
+
+### **I.6.1 Scope**
+
+The XAPI, which is an abbreviation for eXtensive Application Programming Interface, is an operating system and language-independent programming interface to general communication services. Detailed information about the XAPI is given in the main part of this Recommendation, which is very important for understanding this appendix.
+
+Which services are made available via the XAPI depends on the installed service providers and not on the XAPI which only provides the access mechanism.
+
+This part describes the XAPI access to the T.120 conference control. The Generic Conference Control (GCC) protocol is specified in Recommendation T.124.
+
+Figure I.6-1 shows the structure of the protocol stack that is accessible via the XAPI when selecting the conference control provider.
+
+![Diagram showing the structure of the T.120 conference control provider. It includes an Application layer, XAPI layer, T.120 Conference control module (node controller), and a Conference provider box containing T.124 GCC protocol module, T.125 MCS protocol module, and T.123 network-specific transport protocol module.](dbe8aad2b5ea5fdf87cc3a21e496e1b9_img.jpg)
+
+```
+
+graph TD
+    Application[Application] <--> XAPI[XAPI]
+    XAPI <--> T120[T.120 Conference control module  
+(node controller)]
+    T120 <--> T124[T.124 GCC protocol module]
+    subgraph Conference_provider [Conference provider  
+(without node controller  
+and application protocols)]
+        T124 <--> T125[T.125 MCS protocol module]
+        T125 <--> T123[T.123 network-specific  
+transport protocol module]
+    end
+
+```
+
+T0827300-97
+
+Diagram showing the structure of the T.120 conference control provider. It includes an Application layer, XAPI layer, T.120 Conference control module (node controller), and a Conference provider box containing T.124 GCC protocol module, T.125 MCS protocol module, and T.123 network-specific transport protocol module.
+
+**Figure I.6-1/T.180 – Structure of the T.120 conference control provider**
+
+The XAPI user is able to select one transport system (comprising the layers 1 to 4) among the set of transport systems available in the XAPI communication platform to act as the underlying transport service provider.
+
+The conference control provider consists of the T.120 conference control module (node controller) and the T.124 GCC protocol module, the T.125 MCS protocol module, and the T.123 Network-specific-transport protocol stack modules.
+
+The conference provider comprises the T.124 GCC protocol module, the T.125 MCS protocol module, the T.123 Network-specific transport protocol stack modules, the node controller module and the application protocol modules (e.g. the T.127 MBFT protocol module).
+
+When a user (at the terminal) is connected to a conference, all modules of the conference provider are initialized and activated. First the node controller module, the T.124 GCC protocol module, the T.125 MCS protocol module, and the T.123 Network-specific transport protocol stack modules will be initialized and activated. Afterwards, applications may be connected to the conference (see I.7, "XAPI access to the service provider for T.127 MBFT").
+
+The reader should be familiar with the T.120-series of Recommendations (see References).
+
+### **I.6.2 References**
+
+The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; all users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published.
+
+- [T.120] ITU-T Recommendation T.120 (1996), *Data protocols for multimedia conferencing*.
+- [T.122] ITU-T Recommendation T.122 (1993), *Multipoint communication service – Service definition*.
+- [T.123] ITU-T Recommendation T.123 (1996), *Network specific data protocol stacks for multimedia conferencing*.
+- [T.124] ITU-T Recommendation T.124 (1998), *Generic Conference Control*.
+- [T.125] ITU-T Recommendation T.125 (1998), *Multipoint communication service protocol specification*.
+
+### **I.6.3 Definitions**
+
+### **I.6.4 Abbreviations**
+
+This part uses the following abbreviations:
+
+|       |                                             |
+|-------|---------------------------------------------|
+| DSS 1 | Digital Subscriber Signalling System No.1   |
+| GCC   | Generic Conference Control                  |
+| HDLC  | High-Level Data-Link Control                |
+| ISDN  | Integrated Services Digital Network         |
+| MCS   | Multipoint Communication Service            |
+| MCU   | Multipoint Control Unit                     |
+| MBFT  | Multipoint Binary File Transfer             |
+| PDU   | Protocol Data Unit                          |
+| SP    | Service Primitive                           |
+| XAPI  | eXtensive Application Programming Interface |
+
+### **I.6.5 Conventions**
+
+Each service is described via three kinds of tables.
+
+In the first kind of table the service and its service elements are described. It contains a row for each service element of the service (where service element means either request, indication, response, or confirmation) with its corresponding XAPI function and a short description.
+
+In the second kind of table the use of the service primitive parameters within the service elements are described. It contains a row for each service primitive parameter of the service. The service primitive parameter name is stored within the first column; the succeeding columns contain the use of the parameter in the service elements:
+
+Blank The service parameter is absent.
+
+- C Presence of the service parameter is conditional. Firstly, there may be a condition in the service provider to provide a parameter in an indication or confirmation; secondly, there may be interdependencies between parameters of the same or the preceding service primitive.
+- M Presence of the service parameter is mandatory.
+- U Presence of the service parameter is a user option. If the user does not specify a value for such a parameter and there is no default value for that parameter, nothing is passed to the service provider. If the user does not specify a value for such a parameter and there is a default value, the default value is passed to the service provider.
+- (=) The value of the service parameter is identical to the value of the corresponding service parameter in the preceding service element. In the special case of a parameter, whose presence in the preceding service is a user option, for which a default value is defined, and the parameter was not specified in the preceding service element, the symbol (=) indicates that the parameter value is identical to the default value.
+
+The third kind of table is used to describe the service primitive parameter containing the type of value and its scope, possible default values and a detailed description. For each service primitive parameter one description table is given.
+
+A **naming convention** is used throughout the XAPI in order to distinguish between the common functions, identifiers and values, and service-specific identifiers and values. All service-specific settings of the node controller service access are defined within the present part of this appendix and start with **X\_CON\_** or **x\_con\_**.
+
+Extended naming conventions:
+
+- SP\_ Service Primitive;
+- P\_ Parameter;
+- PV\_ Parameter Value;
+- O\_ Option;
+- OV\_ Option Value.
+
+### 1.6.6 Introduction to the conference control provider access
+
+The conference control provider enables a user to participate in a conference.
+
+The service is provided by a combination of a transport system according to Recommendation T.123, the MCS protocol module according to Recommendations T.125 and T.122, the GCC protocol module according to Recommendation T.124, and functions of the node controller.
+
+The T.120 conference control provider offers the XAPI user the following groups of services as defined in the T.124 GCC service:
+
+- conference establishment and termination;
+- conference roster;
+- application roster;
+- conference conductorship;
+- miscellaneous functions.
+
+All mandatory and some conditional services of the T.124 GCC service are supported. The following services of the above specified groups are supported:
+
+- *Conference establishment and termination* – conference creation, conference query, joining a conference, invitation to a conference (passive only), leaving a conference, indication of ejection of a user, indication of termination of a conference;
+
+- *Conference roster* – indication of the actual conference roster, announce of the presence in a conference (this service is not visible to the XAPI user);
+- *Application roster* – application roster report indication;
+- *Conference conductorship* – indication of conductor assign and release, information about the conference conductor, if any;
+- *Miscellaneous functions*.
+
+Recommendation T.120 supports the following configurations:
+
+- direct connection between two terminals without MCU
+
+![Diagram showing a direct connection between two terminals without an MCU.](b3e20b3a7c662b6f564c2b92175a2909_img.jpg)
+
+```
+
+graph LR
+    T1([Terminal]) --- T2([Terminal])
+  
+```
+
+T0827310-97
+
+Diagram showing a direct connection between two terminals without an MCU.
+
+**Figure I.6-2/T.180 – Example configuration: Direct connection between two terminals without MCU**
+
+- connection between terminals and multiport terminals without MCUs
+
+![Diagram showing a connection between a terminal, a multiport terminal, and another terminal without MCUs.](b18c13296cba7ef8a7113fc1b8ac6ef1_img.jpg)
+
+```
+
+graph LR
+    T1([Terminal]) --- MT([Multiport terminal])
+    MT --- T2([Terminal])
+  
+```
+
+T0827320-97
+
+Diagram showing a connection between a terminal, a multiport terminal, and another terminal without MCUs.
+
+**Figure I.6-3/T.180 – Example configuration: Connection between terminals and multiport terminals without MCUs**
+
+- hierarchical configuration of MCUs and terminals
+
+![Diagram showing a hierarchical configuration of MCUs and terminals.](b441ce2f4621bf0259ef1965a02eebea_img.jpg)
+
+```
+
+graph TD
+    MCU1([MCU]) --- MCU2([MCU])
+    MCU1 --- MCU3([MCU])
+    MCU2 --- T1([Terminal])
+    MCU2 --- T2([Terminal])
+    MCU3 --- T3([Terminal])
+    MCU3 --- T4([Terminal])
+  
+```
+
+T0827330-97
+
+Diagram showing a hierarchical configuration of MCUs and terminals.
+
+**Figure I.6-4/T.180 – Example configuration: Hierarchical configuration of MCUs and terminals**
+
+Restrictions, which are made for implementation:
+
+Only the hierarchical configuration of MCUs and terminals is supported. Each terminal is directly connected to a MCU (see Figure I.6-4).
+
+The XAPI interface is taken into consideration only in a terminal. Therefore, only GCC services which correspond to a terminal are allowed.
+
+Optional and most conditional services are not supported:
+
+- *Conference establishment and termination* – active invitation to conference, lock or unlock the conference, information about change between locked or unlocked, active termination of a conference, active ejection of a user, active conference transfer;
+- *Conference roster* – information about the actual conference roster;
+- *Application roster* – active or passive invocation of an application;
+- *Conference conductorship* – active conductor assign, active conductor release, conductor please, conductor give, conductor permission ask and grant;
+- *Miscellaneous functions* – conference time remaining, conference time inquire, conference extend, conference assistance, conference text message.
+
+### **I.6.7 Description of the access to the conference control provider**
+
+#### **I.6.7.1 Service initialization**
+
+##### **I.6.7.1.1 Creation of a conference control service access point with `x_open()`**
+
+A communication endpoint accessing conference control service provider is created when calling the `x_open()` function with an appropriate service provider identification string. The available identifiers depend on the actual system configuration. In the standard configuration, "X\_T.120\_CONF\_ISDN" identifies the conference control provider with the node controller, T.124 GCC and T.122/T.125 MCS as underlying functionality as well as a transport system based on the ISDN network. On the protocol levels two to four, there are implementations of HDLC LAP B, ISO 8208 and T.70.
+
+##### **I.6.7.1.2 Selection of the underlying transport system with `x_bind()`**
+
+`x_bind()` is to be called to activate the conference control service endpoint. The function has the following tasks:
+
+- If the service provider, which has been selected with `x_open()`, does not comprise a transport system, link a transport system below the available protocol modules;
+- Bind an address to the service endpoint.
+
+If the service provider X\_T.120\_CONF\_ISDN has been selected in the `x_open()` function, no transport system has to be specified in the `x_bind()` function.
+
+##### **I.6.7.1.3 Protocol addresses**
+
+The protocol address to be used for the conference control service is the NSAP address. Selectors are meaningless for the conference control service.
+
+###### **I.6.7.1.3.1 The application's own address**
+
+The own address may be specified in the `own_address` buffer of the `bind_struct` passed as argument to the `x_bind()` function. It is returned in the `called_addr` buffer of the `x_conind()` function.
+
+For a passive application it is not supported to specify the own responding NSAP address in the `address` buffer of the `call_struct` in the `x_conrsp()` function, as this value is not transferred by the network.
+
+Note that specification of the application's own protocol address is completely optional. If no address information is specified, the own address is derived from system configuration information and the bound value is returned as output parameter of the *x\_bind()* function.
+
+The own address consists of the NSAP address only. The NSAP address has to comprise the local ISDN outband address, i.e. the address information used in the D-channel. The own ISDN inband address and subaddress parameters as well as the protocol selectors are meaningless for the conference control service. If specified, they will be ignored.
+
+Table I.6-1 shows the address component which has to be specified in the *x\_bind()* call:
+
+**Table I.6-1/T.180 – Address component specified in the *x\_bind()* call**
+
+| ISDN network | Address component | Value                                                                            |
+|--------------|-------------------|----------------------------------------------------------------------------------|
+| ISDN/DSS 1   | A_OUTBAND_ADR     | A decimal digit, which is locally mapped on the Multiple Subscriber Number (MSN) |
+
+###### **I.6.7.1.3.2 The address of the communication partner**
+
+On the sending side, the address of the communication partner has to be specified in the *address* buffer of the *call\_struct* passed as argument to the *x\_conreq()* function. On the receiving side, the address of the communication partner is returned in the *calling\_addr* buffer of the *x\_conind()* function.
+
+The address of the communication partner comprises at least the peer's ISDN outband address. The peer's ISDN inband address and subaddress as well as the protocol selectors are meaningless for the conference control service.
+
+Table I.6-2 shows the address component to be used in the *address* buffer specifying the called NSAP address in a *x\_conreq()* call:
+
+**Table I.6-2/T.180 – Address component specifying the called NSAP address in a *x\_conreq()* call**
+
+| ISDN network | Address component | Value                                                                                      |
+|--------------|-------------------|--------------------------------------------------------------------------------------------|
+| ISDN/DSS 1   | A_OUTBAND_ADR     | Optional the country code, optional the area code and the Multiple Subscriber Number (MSN) |
+
+##### **I.6.7.1.4 Configuration of the service provider**
+
+Protocol options are used to control the general behavior of the service provider. There is a default value defined for each option. These preconfigured values are sufficient for the majority of communication relations.
+
+XAPI enables applications to express their wishes about the settings of protocol options by using the XAPI function *x\_optmgmt()*.
+
+Tables I.6-3 and I.6-4 define the protocol options.
+
+**Table I.6-3/T.180**
+
+|               |                                              |
+|---------------|----------------------------------------------|
+| Option name   | X_CON_O_AROSTER                              |
+| Type of value | unsigned long                                |
+| Legal values  | PV_TRUE<br>PV_FALSE                          |
+| Default value | PV_TRUE                                      |
+| Attributes    |                                              |
+| Description   | Receiving of application roster indications. |
+
+**Table I.6-4/T.180**
+
+|               |                                             |
+|---------------|---------------------------------------------|
+| Option name   | X_CON_O_CROSTER                             |
+| Type of value | unsigned long                               |
+| Legal values  | PV_TRUE<br>PV_FALSE                         |
+| Default value | PV_TRUE                                     |
+| Attributes    |                                             |
+| Description   | Receiving of Conference Roster Indications. |
+
+#### **I.6.7.2 Connection Establishment service**
+
+##### **I.6.7.2.1 Service description**
+
+The Connection Establishment service enables the XAPI user to become a participant of a conference. There are two possibilities to become a participant:
+
+- The XAPI user itself will actively become a participant of a conference. In this case the x\_conreq and x\_conconf connection establishment service elements are used.
+- The XAPI user is invited to a conference. In this case the x\_conind and x\_conrsp connection establishment service elements are used.
+
+When the terminal is a participant of the conference, all supported applications (e.g. T.127 MBFT) can be started.
+
+The elements of the Connection Establishment service and the corresponding XAPI functions for the active participation are defined in Table I.6-5.
+
+**Table I.6-5/T.180 – Service elements and their corresponding XAPI functions for Connection Establishment for active participation**
+
+| Service element      | XAPI function | Description                                                                                                                                                                                                                                                                    |
+|----------------------|---------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Connect Request      | x_conreq()    | The Connect Request is passed to the provider to request the establishment of a connection to the Top provider of the conference. The own local capabilities to be used may be specified as service parameters. If no capabilities are specified, the default values are used. |
+| Connect Confirmation | x_conconf()   | The Connect Confirmation is a positive or negative response to a previous connection establishment request. A positive confirmation indicates that the terminal is a participant of the conference.                                                                            |
+
+The elements of the Connection Establishment service and the corresponding XAPI functions for invitation to participate in a conference are defined in Table I.6-6.
+
+**Table I.6-6/T.180 – Service elements and their corresponding XAPI functions for Connection Establishment for invitation to participate**
+
+| Service element    | XAPI function | Description                                                                                                                                                                                                                                                                 |
+|--------------------|---------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Connect Indication | x_conind()    | The Connect Indication is passed from the provider to the user to request the establishment of a connection to the conference. The own local capabilities to be used may be specified as service parameters. If no capabilities are specified, the default values are used. |
+| Connect Response   | x_conrsp()    | The Connect Response is a positive or negative response to a previous connection establishment indication. A positive response indicates that the terminal will be a participant of the conference.                                                                         |
+
+##### **I.6.7.2.2 Service parameters for active participation**
+
+Table I.6-7 specifies the parameters of the Connection Establishment service for active participation in a conference.
+
+The specification of provider capabilities is optional. If a capability parameter is not specified in a service element, the default value will be used by the service provider. The default value itself is defined by the value of a protocol option. For each capability parameter there is a corresponding protocol option which defines the default value for this parameter. For the protocol option, a constant default value is defined in the XAPI configuration.
+
+**Table I.6-7/T.180 – Parameters of the active participation service**
+
+| Parameter            | Connect service |              |
+|----------------------|-----------------|--------------|
+|                      | Request         | Confirmation |
+| X_CON_P_CR_JOIN      | M               |              |
+| X_CON_P_CONF_NAME    | M               | M (=)        |
+| X_CON_P_CNAME_M_CD   | C               |              |
+| X_CON_P_CNAME_M_CG   | U               |              |
+| X_CON_P_CONV_PASS    | U               |              |
+| X_CON_P_PASS         | C               | C            |
+| X_CON_P_PASS_CLEAR   |                 | C            |
+| X_CON_P_LOCKED       | C               | C            |
+| X_CON_P_LISTED       | C               | C            |
+| X_CON_P_CONDUCT      | C               | C            |
+| X_CON_P_TERM_MOD     | C               | C            |
+| X_CON_P_COND_PRIV    | C               | C            |
+| X_CON_P_COND_M_PRIV  | C               | C            |
+| X_CON_P_NCOND_M_PRIV | C               | C            |
+| X_CON_P_CONF_DESCR   | C               | C            |
+| X_CON_P_CALLER_ID    | U               |              |
+| X_CON_P_LOC_NETADDR  | U               |              |
+| X_CON_P_NODE_NAME    | U               |              |
+| X_CON_P_PART_NAME    | U               |              |
+| X_CON_P_SITE_INFO    | U               |              |
+| X_CON_P_NODE_ID      |                 | C            |
+| X_CON_P_DATA_PRI     | U               | C            |
+| X_CON_P_RESULT       |                 | M            |
+
+# **I.6.7.2.3 Service parameter description for active participation**
+
+Tables I.6-8 to I.6-30 define the parameters for the elements x\_conreq and x\_conconf of the Connection Establishment service.
+
+**Table I.6-8/T.180**
+
+|                |                                                                                                                    |
+|----------------|--------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_CON_P_CR_JOIN                                                                                                    |
+| Type of value  | unsigned long                                                                                                      |
+| Legal values   | X_CON_PV_CREATE<br>X_CON_PV_JOIN                                                                                   |
+| Default value  | X_CON_PV_CREATE                                                                                                    |
+| Description    | The parameter indicates if a new conference shall be created or if the user wishes to join an existing conference. |
+
+**Table I.6-9/T.180**
+
+|                |                                                                                                   |
+|----------------|---------------------------------------------------------------------------------------------------|
+| Parameter name | X_CON_P_CONF_NAME                                                                                 |
+| Type of value  | struct X_CON_P_CONF_NAME {<br>string<256>    numeric_string;<br>string<256>    text_string;<br>}; |
+| Legal values   | a numerical string along with an optional text string, from zero to 255 characters each           |
+| Default value  | none                                                                                              |
+| Description    | Name by which the conference is identified                                                        |
+
+**Table I.6-10/T.180**
+
+|                |                                                                                                                                                                                                                                    |
+|----------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_CON_P_CNAME_M_CD                                                                                                                                                                                                                 |
+| Type of value  | string<255>                                                                                                                                                                                                                        |
+| Legal values   | a numerical string up to 255 digits in length                                                                                                                                                                                      |
+| Default value  | none                                                                                                                                                                                                                               |
+| Description    | Name Modifier by which the conference is identified in the called node if a conference with identical conference name already exists. This parameter is only meaningful if joining a conference (X_CON_P_CR_JOIN = X_CON_PV_JOIN). |
+
+**Table I.6-11/T.180**
+
+|                |                                                                                                                                       |
+|----------------|---------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_CON_P_CNAME_M.CG                                                                                                                    |
+| Type of value  | string<255>                                                                                                                           |
+| Legal values   | a numerical string up to 255 digits in length                                                                                         |
+| Default value  | none                                                                                                                                  |
+| Description    | Name Modifier by which the conference is identified in the calling node if a conference with identical conference name already exists |
+
+**Table I.6-12/T.180**
+
+|                |                                                                                                                       |
+|----------------|-----------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_CON_P_CONV_PASS                                                                                                     |
+| Type of value  | struct X_CON_P_CONV_PASS {<br>string<256>    numeric_string;<br>string<256>    text_string;<br>};                     |
+| Legal values   | a numerical string along with an optional text string, from zero to 255 characters each                               |
+| Default value  | None                                                                                                                  |
+| Description    | Password used by the convener to identify itself. It can be used in later operations, when he rejoins the conference. |
+
+**Table I.6-13/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
+|----------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_CON_P_PASS                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
+| Type of value  | struct X_CON_P_PASS {<br>string<256>    numeric_string;<br>string<256>    text_string;<br>};string                                                                                                                                                                                                                                                                                                                                                                                     |
+| Legal values   | a numerical string along with an optional text string, from zero to 255 characters each                                                                                                                                                                                                                                                                                                                                                                                                |
+| Default value  | none                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
+| Description    | Password for a password-protected conference. If the XAPI user creates the conference (X_CON_P_CR_JOIN = X_CON_PV_CREATE), the conference may be protected with a password in the x_conreq function. If the XAPI user joins the conference (X_CON_P_CR_JOIN = X_CON_PV_JOIN), the x_conreq function must contain this parameter for a password-protected conference. If the password is not o.k., in this case the x_conconf function may contain more information about the password. |
+
+**Table I.6-14/T.180**
+
+|                |                                                                                                                                                                                                              |
+|----------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_CON_P_PASS_CLEAR                                                                                                                                                                                           |
+| Type of value  | unsigned long                                                                                                                                                                                                |
+| Legal values   | PV_TRUE<br>PV_FALSE                                                                                                                                                                                          |
+| Default value  | none                                                                                                                                                                                                         |
+| Description    | It indicates whether it is a password-protected conference. This parameter is used only in the x_conconf function, when it is a response to a x_conreq with the parameter (X_CON_P_CR_JOIN = X_CON_PV_JOIN). |
+
+**Table I.6-15/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                        |
+|----------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_CON_P_LOCKED                                                                                                                                                                                                                                                                                         |
+| Type of value  | unsigned long                                                                                                                                                                                                                                                                                          |
+| Legal values   | PV_TRUE<br>PV_FALSE                                                                                                                                                                                                                                                                                    |
+| Default value  | PV_FALSE                                                                                                                                                                                                                                                                                               |
+| Description    | Setting this parameter indicates that the conference is locked. Nobody can join the conference by itself. New conference participants can only be invited. In the x_conreq function the value PV_TRUE is allowed only in the case when creating a conference (i.e. X_CON_P_CR_JOIN = X_CON_PV_CREATE). |
+
+**Table I.6-16/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
+|----------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_CON_P_LISTED                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
+| Type of value  | unsigned long                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
+| Legal values   | PV_TRUE<br>PV_FALSE                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
+| Default value  | PV_TRUE                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
+| Description    | This parameter indicates that this conference may be listed when using the conference information service. This parameter must be used in the x_conreq function when a conference is created (X_CON_P_CR_JOIN = X_CON_PV_CREATE) but not when joining a conference (X_CON_P_CR_JOIN = X_CON_PV_JOIN). This parameter is used in the x_conconf function when a conference is joined (X_CON_P_CR_JOIN = X_CON_PV_JOIN) but not when creating a conference (X_CON_P_CR_JOIN = X_CON_PV_CREATE). |
+
+**Table I.6-17/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
+|----------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_CON_P_CONDUCT                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
+| Type of value  | PV_TRUE<br>PV_FALSE                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
+| Legal values   | PV_FALSE                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
+| Default value  | none                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
+| Description    | This parameter indicates that the conference may be placed in the conducted mode. This parameter must be used in the x_conreq function when a conference is created (X_CON_P_CR_JOIN = X_CON_PV_CREATE) but not when joining a conference (X_CON_P_CR_JOIN = X_CON_PV_JOIN). This parameter is used in the x_conconf function when a conference is joined (X_CON_P_CR_JOIN = X_CON_PV_JOIN) but not when creating a conference (X_CON_P_CR_JOIN = X_CON_PV_CREATE). |
+
+**Table I.6-18/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
+|----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_CON_P_TERM_MOD                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
+| Type of value  | unsigned long                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
+| Legal values   | X_CON_PV_AUTOMATIC<br>X_CON_PV_MANUAL                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
+| Default value  | X_CON_PV_AUTOMATIC                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
+| Description    | This parameter indicates whether the conference shall remain in existence until explicitly terminated (X_CON_PV_MANUAL) or if the conference will terminate in the case no nodes are joined to it (X_CON_PV_AUTOMATIC). This parameter must be used in the x_conreq function when a conference is created (X_CON_P_CR_JOIN = X_CON_PV_CREATE) but not when joining a conference (X_CON_P_CR_JOIN = X_CON_PV_JOIN). This parameter is used in the x_conconf function when a conference is joined (X_CON_P_CR_JOIN = X_CON_PV_JOIN) but not when creating a conference (X_CON_P_CR_JOIN = X_CON_PV_CREATE). |
+
+**Table I.6-19/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
+|----------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_CON_P_COND_PRIV                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
+| Type of value  | sequence<unsigned long, 6>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
+| Legal values   | PV_TRUE / PV_FALSE    Conference termination;<br>PV_TRUE / PV_FALSE    Eject a user;<br>PV_TRUE / PV_FALSE    Add a user;<br>PV_TRUE / PV_FALSE    Lock a conference;<br>PV_TRUE / PV_FALSE    Unlock a conference;<br>PV_TRUE / PV_FALSE    Conference transfer.                                                                                                                                                                                                                                                                                                             |
+| Default Value  | PV_TRUE, PV_TRUE, PV_TRUE, PV_TRUE, PV_TRUE, PV_TRUE                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
+| Description    | This parameter indicates which functions the convener is designating as allowable to be used by the conference conductor, if any. The values are specified in the same order as listed above. This parameter may be used in the x_conreq function when a conference is created (X_CON_P_CR_JOIN = X_CON_PV_CREATE) but not when joining a conference (X_CON_P_CR_JOIN = X_CON_PV_JOIN). This parameter may be in the x_conconf function when a conference is joined (X_CON_P_CR_JOIN = X_CON_PV_JOIN) but not when creating a conference (X_CON_P_CR_JOIN = X_CON_PV_CREATE). |
+
+**Table I.6-20/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
+|----------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_CON_P_COND_M_PRIV                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
+| Type of value  | sequence<unsigned long, 6>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
+| Legal values   | PV_TRUE / PV_FALSE    Conference termination;<br>PV_TRUE / PV_FALSE    Eject a user;<br>PV_TRUE / PV_FALSE    Add a user;<br>PV_TRUE / PV_FALSE    Lock a conference;<br>PV_TRUE / PV_FALSE    Unlock a conference;<br>PV_TRUE / PV_FALSE    Conference transfer.                                                                                                                                                                                                                                                                                                                    |
+| Default value  | PV_TRUE, PV_TRUE, PV_TRUE, PV_TRUE, PV_TRUE, PV_TRUE                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
+| Description    | This parameter indicates which functions the convener is designating as allowable to be used by any node in a conducted-mode conference. The values are specified in the same order as listed above. This parameter may be used in the x_conreq function when a conference is created (X_CON_P_CR_JOIN = X_CON_PV_CREATE) but not when joining a conference (X_CON_P_CR_JOIN = X_CON_PV_JOIN). This parameter may be in the x_conconf function when a conference is joined (X_CON_P_CR_JOIN = X_CON_PV_JOIN) but not when creating a conference (X_CON_P_CR_JOIN = X_CON_PV_CREATE). |
+
+**Table I.6-21/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
+|----------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_CON_P_NCOND_M_PRIV                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
+| Type of value  | sequence <unsigned long, 6>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
+| Legal values   | PV_TRUE / PV_FALSE    Conference termination;<br>PV_TRUE / PV_FALSE    Eject a user;<br>PV_TRUE / PV_FALSE    Add a user;<br>PV_TRUE / PV_FALSE    Lock a conference;<br>PV_TRUE / PV_FALSE    Unlock a conference;<br>PV_TRUE / PV_FALSE    Conference transfer.                                                                                                                                                                                                                                                                                                                        |
+| Default value  | PV_TRUE, PV_TRUE, PV_TRUE, PV_TRUE, PV_TRUE, PV_TRUE                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
+| Description    | This parameter indicates which functions the convener is designating as allowable to be used by any node in a non-conducted-mode conference. The values are specified in the same order as listed above. This parameter may be used in the x_conreq function when a conference is created (X_CON_P_CR_JOIN = X_CON_PV_CREATE) but not when joining a conference (X_CON_P_CR_JOIN = X_CON_PV_JOIN). This parameter may be in the x_conconf function when a conference is joined (X_CON_P_CR_JOIN = X_CON_PV_JOIN) but not when creating a conference (X_CON_P_CR_JOIN = X_CON_PV_CREATE). |
+
+**Table I.6-22/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                                                        |
+|----------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_CON_P_CONF_DESCR                                                                                                                                                                                                                                                                                                                                                                                                                     |
+| Type of value  | string<256>                                                                                                                                                                                                                                                                                                                                                                                                                            |
+| Legal values   | a text string, from zero to 255 characters                                                                                                                                                                                                                                                                                                                                                                                             |
+| Default value  | none                                                                                                                                                                                                                                                                                                                                                                                                                                   |
+| Description    | This parameter may be used to describe the conference. This parameter may be used in the x_conreq function when a conference is created (X_CON_P_CR_JOIN = X_CON_PV_CREATE) but not when joining a conference (X_CON_P_CR_JOIN = X_CON_PV_JOIN). This parameter may be in the x_conconf function when a conference is joined (X_CON_P_CR_JOIN = X_CON_PV_JOIN) but not when creating a conference (X_CON_P_CR_JOIN = X_CON_PV_CREATE). |
+
+**Table I.6-23/T.180**
+
+|                |                                                          |
+|----------------|----------------------------------------------------------|
+| Parameter name | X_CON_P_CALLER_ID                                        |
+| Type of value  | string<256>                                              |
+| Legal values   | a text string, from zero to 255 characters               |
+| Default value  | none                                                     |
+| Description    | This parameter may be used to describe the calling node. |
+
+**Table I.6-24/T.180**
+
+|                |                                                                                                                                                                                   |
+|----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_CON_P_LOC_NETADDR                                                                                                                                                               |
+| Type of value  | unsigned long                                                                                                                                                                     |
+| Legal values   | PV_TRUE<br>PV_FALSE                                                                                                                                                               |
+| Default value  | PV_FALSE                                                                                                                                                                          |
+| Description    | This parameter is used to indicate whether the local provider shall send the own Network Address parameter or not. This parameter is included in the conference description list. |
+
+**Table I.6-25/T.180**
+
+|                |                                                                                                                       |
+|----------------|-----------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_CON_P_NODE_NAME                                                                                                     |
+| Type of value  | string<255>                                                                                                           |
+| Legal values   | a string up to 255 characters                                                                                         |
+| Default value  | none                                                                                                                  |
+| Description    | This parameter is used to indicate the name of a node. This parameter is included in the conference description list. |
+
+**Table I.6-26/T.180**
+
+|                |                                                                   |
+|----------------|-------------------------------------------------------------------|
+| Parameter name | X_CON_P_PART_NAME                                                 |
+| Type of value  | sequence<string<255> >                                            |
+| Legal values   | a list of strings each up to 255 characters                       |
+| Default value  | none                                                              |
+| Description    | This parameter is used to indicate the names of the participants. |
+
+**Table I.6-27/T.180**
+
+|                |                                                                                                                               |
+|----------------|-------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_CON_P_SITE_INFO                                                                                                             |
+| Type of value  | string<255>                                                                                                                   |
+| Legal values   | a string up to 255 characters                                                                                                 |
+| Default value  | none                                                                                                                          |
+| Description    | This parameter is used to indicate information about the node. This parameter is included in the conference description list. |
+
+**Table I.6-28/T.180**
+
+|                |                                                                                                     |
+|----------------|-----------------------------------------------------------------------------------------------------|
+| Parameter name | X_CON_P_NODE_ID                                                                                     |
+| Type of value  | unsigned long                                                                                       |
+| Legal values   | an integer between 1001 and 65535                                                                   |
+| Default value  | none                                                                                                |
+| Description    | This parameter is used to indicate the own node identification from the local provider to the user. |
+
+**Table I.6-29/T.180**
+
+|                |                                                                            |
+|----------------|----------------------------------------------------------------------------|
+| Parameter name | X_CON_P_DATA_PRI                                                           |
+| Type of value  | unsigned long                                                              |
+| Legal values   | an integer between 1 and 4                                                 |
+| Default value  | 1                                                                          |
+| Description    | This parameter is used to indicate the number of data transfer priorities. |
+
+**Table I.6-30/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                                                                                                                                                                                       |
+|----------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_CON_P_RESULT                                                                                                                                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                                                                                                                                                                                       |
+| Type of value  | unsigned long                                                                                                                                                                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                                                                                                                                       |
+| Legal values   | X_CON_PV_ACCEPT<br>X_CON_PV_USER_REJECTED<br>X_CON_PV_RESOURCE_NOT_AVAIL<br>X_CON_PV_SYMMETRY_BREAK<br>X_CON_PV_ILOCKED_NOT_SUPP<br>X_CON_PV_NAME/MOD_EXIST<br>X_CON_PV_DOM_PAR_UNACC<br>X_CON_PV_DOM_NOT_HIERARCH<br>X_CON_PV_LOWER_LAY_DIS<br>X_CON_PV_UNSPECIFIED<br>X_CON_PV_INV_CONF<br>X_CON_PV_INV_PASSW<br>X_CON_PV_CHALLENGE_RSP_REQ<br>X_CON_PV_INV_CHALLENGE_RSP<br>X_CON_PV_INV_CONVENER_PASSW | Accepted;<br>User rejected;<br>Resources not available;<br>Symmetry breaking;<br>Locked conference not supported;<br>Conference name and modifier already exist;<br>Domain parameters unacceptable;<br>Domain not hierarchical;<br>Lower layer initiated disconnect;<br>Unspecified failure;<br>Invalid conference;<br>Invalid password;<br>Challenge response required;<br>Invalid challenge response;<br>Invalid convener password. |
+| Default value  | X_CON_PV_ACCEPT                                                                                                                                                                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                                                                                                                                                                                       |
+| Description    | This parameter indicates the success or failure of the connection establishment request.                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                                                                                                                       |
+
+#### I.6.7.2.4 Service parameters for invitation to participate in a conference
+
+**Table I.6-31/T.180 – Parameters for invitation to participate service**
+
+| Parameter          | Connect service |          |
+|--------------------|-----------------|----------|
+|                    | Indication      | Response |
+| X_CON_P_CONF_NAME  | M               | M (=)    |
+| X_CON_P_CNAME_MOD  |                 | C        |
+| X_CON_P_CALLER_ID  | U               |          |
+| X_CON_P_PASS_CLEAR | M               |          |
+| X_CON_P_LOCKED     | M               |          |
+| X_CON_P_LISTED     | M               |          |
+
+**Table I.6-31/T.180 – Parameters for invitation to participate service (concluded)**
+
+| Parameter            | Connect service |          |
+|----------------------|-----------------|----------|
+|                      | Indication      | Response |
+| X_CON_P_CONDUCT      | M               |          |
+| X_CON_P_TERM_MOD     | M               |          |
+| X_CON_P_COND_PRIV    | C               |          |
+| X_CON_P_COND_M_PRIV  | C               |          |
+| X_CON_P_NCOND_M_PRIV | C               |          |
+| X_CON_P_CONF_DESCR   | C               |          |
+| X_CON_P_LOC_NETADDR  |                 | U        |
+| X_CON_P_DATA_PRI     | C               | C        |
+| X_CON_P_RESULT       |                 | M        |
+
+**I.6.7.2.5 Service parameter description for invitation to participate in a conference**
+
+Tables I.6-32 to I.6-46 define the parameters for the elements x\_conind and x\_conrsp of the Connection Establishment service.
+
+**Table I.6-32/T.180**
+
+|                |                                                                                             |
+|----------------|---------------------------------------------------------------------------------------------|
+| Parameter name | X_CON_P_CONF_NAME                                                                           |
+| Type of value  | struct X_CON_P_CONF_NAME {<br>string<256> numeric_string;<br>string<256> text_string;<br>}; |
+| Legal values   | a numerical string along with an optional text string, from zero to 255 characters each     |
+| Default value  | none                                                                                        |
+| Description    | Name by which the conference is identified.                                                 |
+
+**Table I.6-33/T.180**
+
+|                |                                                                                                                                       |
+|----------------|---------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_CON_P_CNAME_MOD                                                                                                                     |
+| Type of value  | string<255>                                                                                                                           |
+| Legal values   | a numerical string up to 255 digits in length                                                                                         |
+| Default value  | none                                                                                                                                  |
+| Description    | Name Modifier by which the conference is identified in the called node if a conference with identical conference name already exists. |
+
+**Table I.6-34/T.180**
+
+|                |                                                               |
+|----------------|---------------------------------------------------------------|
+| Parameter name | X_CON_P_CALLER_ID                                             |
+| Type of value  | string<256>                                                   |
+| Legal values   | This parameter is a text string, from zero to 255 characters. |
+| Default value  | none                                                          |
+| Description    | This parameter may be used to describe the calling node.      |
+
+**Table I.6-35/T.180**
+
+|                |                                                             |
+|----------------|-------------------------------------------------------------|
+| Parameter name | X_CON_P_PASS_CLEAR                                          |
+| Type of value  | unsigned long                                               |
+| Legal values   | PV_TRUE<br>PV_FALSE                                         |
+| Default value  | none                                                        |
+| Description    | It indicates whether it is a password-protected conference. |
+
+**Table I.6-36/T.180**
+
+|                |                                                                                                                                                          |
+|----------------|----------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_CON_P_LOCKED                                                                                                                                           |
+| Type of value  | unsigned long                                                                                                                                            |
+| Legal values   | PV_TRUE<br>PV_FALSE                                                                                                                                      |
+| Default value  | PV_FALSE                                                                                                                                                 |
+| Description    | Setting this parameter indicates that the conference is locked. Nobody can join the conference itself. A new conference participant can only be invited. |
+
+**Table I.6-37/T.180**
+
+|                |                                                                                                            |
+|----------------|------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_CON_P_LISTED                                                                                             |
+| Type of value  | unsigned long                                                                                              |
+| Legal values   | PV_TRUE<br>PV_FALSE                                                                                        |
+| Default value  | PV_TRUE                                                                                                    |
+| Description    | This parameter indicates that this conference may be listed when using the conference information service. |
+
+**Table I.6-38/T.180**
+
+|                |                                                                                   |
+|----------------|-----------------------------------------------------------------------------------|
+| Parameter name | X_CON_P_CONDUCT                                                                   |
+| Type of value  | PV_TRUE<br>PV_FALSE                                                               |
+| Legal values   | PV_FALSE                                                                          |
+| Default value  | none                                                                              |
+| Description    | This parameter indicates that the conference may be placed in the conducted mode. |
+
+**Table I.6-39/T.180**
+
+|                |                                                                                                                                                                                                                        |
+|----------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_CON_P_TERM_MOD                                                                                                                                                                                                       |
+| Type of value  | unsigned long                                                                                                                                                                                                          |
+| Legal values   | X_CON_PV_AUTOMATIC<br>X_CON_PV_MANUAL                                                                                                                                                                                  |
+| Default value  | X_CON_PV_AUTOMATIC                                                                                                                                                                                                     |
+| Description    | This parameter indicates whether the conference shall remain in existence until explicitly terminated (X_CON_PV_MANUAL) or if the conference will terminate when there are no nodes joined to it (X_CON_PV_AUTOMATIC). |
+
+**Table I.6-40/T.180**
+
+|                |                                                                                                                                                                                                                                                                   |
+|----------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_CON_P_COND_PRIV                                                                                                                                                                                                                                                 |
+| Type of value  | sequence <unsigned long>                                                                                                                                                                                                                                          |
+| Legal values   | PV_TRUE / PV_FALSE    Conference termination;<br>PV_TRUE / PV_FALSE    Eject a user;<br>PV_TRUE / PV_FALSE    Add a user;<br>PV_TRUE / PV_FALSE    Lock a conference;<br>PV_TRUE / PV_FALSE    Unlock a conference;<br>PV_TRUE / PV_FALSE    Conference transfer. |
+| Default value  | PV_TRUE , PV_TRUE , PV_TRUE , PV_TRUE , PV_TRUE , PV_TRUE                                                                                                                                                                                                         |
+| Description    | This parameter indicates which functions the convener has designated as allowable to be used by the conference conductor, if any. The values are specified in the same order as listed above.                                                                     |
+
+**Table I.6-41/T.180**
+
+|                |                                                                                                                                                                                                                                                                   |
+|----------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_CON_P_COND_M_PRIV                                                                                                                                                                                                                                               |
+| Type of value  | sequence<unsigned long, 6>                                                                                                                                                                                                                                        |
+| Legal values   | PV_TRUE / PV_FALSE    Conference termination;<br>PV_TRUE / PV_FALSE    Eject a user;<br>PV_TRUE / PV_FALSE    Add a user;<br>PV_TRUE / PV_FALSE    Lock a conference;<br>PV_TRUE / PV_FALSE    Unlock a conference;<br>PV_TRUE / PV_FALSE    Conference transfer. |
+| Default value  | PV_TRUE, PV_TRUE, PV_TRUE, PV_TRUE, PV_TRUE, PV_TRUE                                                                                                                                                                                                              |
+| Description    | This parameter indicates which functions the convener has designated as allowable to be used by any node in a conducted-mode conference. The values are specified in the same order as listed above.                                                              |
+
+**Table I.6-42/T.180**
+
+|                |                                                                                                                                                                                                                                                                   |
+|----------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_CON_P_NCOND_M_PRIV                                                                                                                                                                                                                                              |
+| Type of value  | sequence <unsigned long, 6>                                                                                                                                                                                                                                       |
+| Legal values   | PV_TRUE / PV_FALSE    Conference termination;<br>PV_TRUE / PV_FALSE    Eject a user;<br>PV_TRUE / PV_FALSE    Add a user;<br>PV_TRUE / PV_FALSE    Lock a conference;<br>PV_TRUE / PV_FALSE    Unlock a conference;<br>PV_TRUE / PV_FALSE    Conference transfer. |
+| Default value  | PV_TRUE, PV_TRUE, PV_TRUE, PV_TRUE, PV_TRUE, PV_TRUE                                                                                                                                                                                                              |
+| Description    | This parameter indicates which functions the convener has designated as allowable to be used by any node in a non-conducted-mode conference. The values are specified in the same order as listed above.                                                          |
+
+**Table I.6-43/T.180**
+
+|                |                                                               |
+|----------------|---------------------------------------------------------------|
+| Parameter name | X_CON_P_CONF_DESCR                                            |
+| Type of value  | string<256>                                                   |
+| Legal values   | This parameter is a text string, from zero to 255 characters. |
+| Default value  | none                                                          |
+| Description    | This parameter may be used to describe the conference.        |
+
+**Table I.6-44/T.180**
+
+|                |                                                                                                                                                                                   |
+|----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_CON_P_LOC_NETADDR                                                                                                                                                               |
+| Type of value  | unsigned long                                                                                                                                                                     |
+| Legal values   | PV_TRUE<br>PV_FALSE                                                                                                                                                               |
+| Default value  | PV_FALSE                                                                                                                                                                          |
+| Description    | This parameter is used to indicate whether the local provider shall send the own Network Address parameter or not. This parameter is included in the conference description list. |
+
+**Table I.6-45/T.180**
+
+|                |                                                                            |
+|----------------|----------------------------------------------------------------------------|
+| Parameter name | X_CON_P_DATA_PRI                                                           |
+| Type of value  | unsigned long                                                              |
+| Legal values   | an integer between 1 and 4                                                 |
+| Default value  | 1                                                                          |
+| Description    | This parameter is used to indicate the number of data transfer priorities. |
+
+**Table I.6-46/T.180**
+
+|                |                                                                                                                                                              |
+|----------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_CON_P_RESULT                                                                                                                                               |
+| Type of value  | unsigned long                                                                                                                                                |
+| Legal values   | X_CON_PV_ACCEPT                      Accepted;<br>X_CON_PV_USER_REJECT              User rejected;<br>X_CON_PV_UNSPECIFIED              Unspecified failure. |
+| Default value  | X_CON_PV_ACCEPT                                                                                                                                              |
+| Description    | This parameter indicates the success or failure of the connection establishment request.                                                                     |
+
+In the non-connected state there is also the Query Information service available.
+
+### **I.6.7.3 Services in the connected state**
+
+There are no services available except all information services.
+
+### **I.6.7.4 Disconnect service**
+
+#### **I.6.7.4.1 Service description**
+
+The Disconnect service enables the XAPI user to leave a conference. There are two possibilities to leave the conference:
+
+- The XAPI user itself will actively leave a conference. In this case the x\_snddis XAPI function is used.
+- The XAPI user is disconnected from a conference. In this case the x\_rcvdis XAPI function is used.
+
+The service elements of the Disconnect service and the corresponding XAPI functions are defined in Table I.6-47.
+
+**Table I.6-47/T.180 – Service elements and their corresponding XAPI functions for the Disconnect service**
+
+| Service element       | XAPI function | Description                                                                                                                   |
+|-----------------------|---------------|-------------------------------------------------------------------------------------------------------------------------------|
+| Disconnect Request    | x_snddis()    | The Disconnect Request is passed to the provider to disconnect itself from the conference.                                    |
+| Disconnect Indication | x_rcvdis()    | The Disconnect Indication is passed to the user to indicate that the node is no longer a participant of the conference.       |
+| End Indication        | x_revend()    | The End Indication is generated by the provider to indicate that the service provider is ready to establish a new connection. |
+
+#### **I.6.7.4.2 Service parameters**
+
+Table I.6-48 specifies the parameters of the Disconnect service.
+
+**Table I.6-48/T.180 – Parameters of the Disconnect service**
+
+| Parameter         | Disconnect service |            |
+|-------------------|--------------------|------------|
+|                   | Request            | Indication |
+| X_CON_P_TERM_NODE |                    | C          |
+| X_CON_P_REASON    |                    | C          |
+
+### I.6.7.4.3 Service parameter description
+
+Tables I.6-49 and I.6-50 define the parameters for the functions x\_snddis and x\_rcvdis of the Disconnect service.
+
+**Table I.6-49/T.180**
+
+|                |                                                                                         |
+|----------------|-----------------------------------------------------------------------------------------|
+| Parameter name | X_CON_P_TERM_NODE                                                                       |
+| Type of value  | unsigned long                                                                           |
+| Legal values   | an integer between 1001 and 65535                                                       |
+| Default value  | none                                                                                    |
+| Description    | This parameter indicates the node ID of that node which was requesting the termination. |
+
+**Table I.6-50/T.180**
+
+|                |                                                            |                                                               |
+|----------------|------------------------------------------------------------|---------------------------------------------------------------|
+| Parameter name | X_CON_P_REASON                                             |                                                               |
+| Type of value  | unsigned long                                              |                                                               |
+| Legal values   | X_CON_PV_USER_INI                                          | User initiated;                                               |
+|                | X_CON_PV_EJECTED_NODE                                      | Ejected node;                                                 |
+|                | X_CON_PV_UNKNOWN                                           | Unknown;                                                      |
+|                | X_CON_PV_NORM_TERM                                         | Requested normal termination;                                 |
+|                | X_CON_PV_TIMED_TERM                                        | Requested timed conference termination;                       |
+|                | X_CON_PV_NO_PART                                           | No more participants in automatically terminating conference; |
+|                | X_CON_PV_ERROR                                             | Error termination;                                            |
+|                | X_CON_PV_HNODE_DIS                                         | Higher node disconnected;                                     |
+|                | X_CON_PV_HNODE_EJECT                                       | Higher node ejected.                                          |
+| Default value  | none                                                       |                                                               |
+| Description    | This parameter indicates the reason for the disconnection. |                                                               |
+
+In the non-connected state there is also the Query Information service available.
+
+### I.6.7.5 Conference Information service
+
+#### I.6.7.5.1 Conference Query service
+
+This service may be used to determine what conferences are currently in existence at a particular MCU. This service is available to the user in every state of the XAPI.
+
+#### I.6.7.5.1.1 Service description
+
+The service elements and their corresponding XAPI functions needed for the Conference Query service are described in Table I.6-51.
+
+**Table I.6-51/T.180 – Service elements and their corresponding XAPI functions for the Query service**
+
+| Service element    | Service element identifier | XAPI function | Description                                                                                                                        |
+|--------------------|----------------------------|---------------|------------------------------------------------------------------------------------------------------------------------------------|
+| Query Request      | X_CON_QUERY_Q              | x_sndinfo()   | The Information Request is passed to the provider to request the information about actual listed conferences in the requested MCU. |
+| Query Confirmation | X_CON_QUERY_C              | x_rcvinfo()   | The Information Confirmation is a positive or negative response to a previous information request.                                 |
+
+#### I.6.7.5.1.2 Service parameters
+
+Table I.6-52 specifies the parameters of the Query service.
+
+**Table I.6-52/T.180 – Parameters of the Query service**
+
+| Parameter          | Conference Query service |              |
+|--------------------|--------------------------|--------------|
+|                    | Request                  | Confirmation |
+| X_CON_P_DESCR_LIST |                          | C            |
+| X_CON_P_USER_DATA  | O                        | O            |
+| X_CON_P_RESULT     |                          | M            |
+
+#### I.6.7.5.1.3 Service parameter description
+
+Tables I.6-53 to I.6-55 specify the parameters of the Query service.
+
+**Table I.6-53/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |                                 |            |               |                  |                |               |                           |                |               |                         |              |                  |                                |               |                 |                                 |           |               |                  |
+|----------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------|------------|---------------|------------------|----------------|---------------|---------------------------|----------------|---------------|-------------------------|--------------|------------------|--------------------------------|---------------|-----------------|---------------------------------|-----------|---------------|------------------|
+| Parameter name | X_CON_P_DESCR_LIST                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |                                 |            |               |                  |                |               |                           |                |               |                         |              |                  |                                |               |                 |                                 |           |               |                  |
+| Type of value  | <pre>typedef struct Description {     string Conf_Name;     string Name_Modifier;     string Conf_Descript;     unsigned long    Lock_Unlock;     unsigned long    Passw_in_Clear;     string Net_Addr; }; sequence&lt;Description&gt;;</pre>                                                                                                                                                                                                                                                                                                                |                                 |            |               |                  |                |               |                           |                |               |                         |              |                  |                                |               |                 |                                 |           |               |                  |
+| Legal values   | <table> <tr> <td>Conf_Name:</td><td>A text string</td><td>Conference name;</td></tr> <tr> <td>Name_Modifier:</td><td>A text string</td><td>Conference name modifier;</td></tr> <tr> <td>Conf_Descript:</td><td>A text string</td><td>Conference description;</td></tr> <tr> <td>Lock_Unlock:</td><td>PV_TRUE,PV_FALSE</td><td>Conference locked or unlocked;</td></tr> <tr> <td>Passw_in_Clea</td><td>PV_TRUE,PVFALSE</td><td>Password in the clear required;</td></tr> <tr> <td>Net_Addr:</td><td>A text string</td><td>Network address.</td></tr> </table> |                                 | Conf_Name: | A text string | Conference name; | Name_Modifier: | A text string | Conference name modifier; | Conf_Descript: | A text string | Conference description; | Lock_Unlock: | PV_TRUE,PV_FALSE | Conference locked or unlocked; | Passw_in_Clea | PV_TRUE,PVFALSE | Password in the clear required; | Net_Addr: | A text string | Network address. |
+| Conf_Name:     | A text string                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                | Conference name;                |            |               |                  |                |               |                           |                |               |                         |              |                  |                                |               |                 |                                 |           |               |                  |
+| Name_Modifier: | A text string                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                | Conference name modifier;       |            |               |                  |                |               |                           |                |               |                         |              |                  |                                |               |                 |                                 |           |               |                  |
+| Conf_Descript: | A text string                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                | Conference description;         |            |               |                  |                |               |                           |                |               |                         |              |                  |                                |               |                 |                                 |           |               |                  |
+| Lock_Unlock:   | PV_TRUE,PV_FALSE                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             | Conference locked or unlocked;  |            |               |                  |                |               |                           |                |               |                         |              |                  |                                |               |                 |                                 |           |               |                  |
+| Passw_in_Clea  | PV_TRUE,PVFALSE                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              | Password in the clear required; |            |               |                  |                |               |                           |                |               |                         |              |                  |                                |               |                 |                                 |           |               |                  |
+| Net_Addr:      | A text string                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                | Network address.                |            |               |                  |                |               |                           |                |               |                         |              |                  |                                |               |                 |                                 |           |               |                  |
+| Default value  | none                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |                                 |            |               |                  |                |               |                           |                |               |                         |              |                  |                                |               |                 |                                 |           |               |                  |
+| Description    | This parameter contains the conference description list with the specified parameters for each listed conference in the requested node.                                                                                                                                                                                                                                                                                                                                                                                                                      |                                 |            |               |                  |                |               |                           |                |               |                         |              |                  |                                |               |                 |                                 |           |               |                  |
+
+**Table I.6-54/T.180**
+
+|                |                                                               |
+|----------------|---------------------------------------------------------------|
+| Parameter name | X_CON_P_USER_DATA                                             |
+| Type of value  | string<256>                                                   |
+| Legal values   | This parameter is a text string, from zero to 255 characters. |
+| Default value  | none                                                          |
+| Description    | This parameter may be used for optional user data.            |
+
+**Table I.6-55/T.180**
+
+|                           |                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |  |                 |           |                        |                |                        |                                 |                           |                          |                        |                                   |                      |                      |
+|---------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--|-----------------|-----------|------------------------|----------------|------------------------|---------------------------------|---------------------------|--------------------------|------------------------|-----------------------------------|----------------------|----------------------|
+| Parameter name            | X_CON_P_RESULT                                                                                                                                                                                                                                                                                                                                                                                                                                                  |  |                 |           |                        |                |                        |                                 |                           |                          |                        |                                   |                      |                      |
+| Type of value             | unsigned long                                                                                                                                                                                                                                                                                                                                                                                                                                                   |  |                 |           |                        |                |                        |                                 |                           |                          |                        |                                   |                      |                      |
+| Legal values              | <table> <tr> <td>X_CON_PV_ACCEPT</td><td>Accepted;</td></tr> <tr> <td>X_CON_PV_USER_REJECTED</td><td>User rejected;</td></tr> <tr> <td>X_CON_PV_DOM_PAR_UNACC</td><td>Domain parameters unacceptable;</td></tr> <tr> <td>X_CON_PV_DOM_NOT_HIERARCH</td><td>Domain not hierarchical;</td></tr> <tr> <td>X_CON_PV_LOWER_LAY_DIS</td><td>Lower layer initiated disconnect;</td></tr> <tr> <td>X_CON_PV_UNSPECIFIED</td><td>Unspecified failure.</td></tr> </table> |  | X_CON_PV_ACCEPT | Accepted; | X_CON_PV_USER_REJECTED | User rejected; | X_CON_PV_DOM_PAR_UNACC | Domain parameters unacceptable; | X_CON_PV_DOM_NOT_HIERARCH | Domain not hierarchical; | X_CON_PV_LOWER_LAY_DIS | Lower layer initiated disconnect; | X_CON_PV_UNSPECIFIED | Unspecified failure. |
+| X_CON_PV_ACCEPT           | Accepted;                                                                                                                                                                                                                                                                                                                                                                                                                                                       |  |                 |           |                        |                |                        |                                 |                           |                          |                        |                                   |                      |                      |
+| X_CON_PV_USER_REJECTED    | User rejected;                                                                                                                                                                                                                                                                                                                                                                                                                                                  |  |                 |           |                        |                |                        |                                 |                           |                          |                        |                                   |                      |                      |
+| X_CON_PV_DOM_PAR_UNACC    | Domain parameters unacceptable;                                                                                                                                                                                                                                                                                                                                                                                                                                 |  |                 |           |                        |                |                        |                                 |                           |                          |                        |                                   |                      |                      |
+| X_CON_PV_DOM_NOT_HIERARCH | Domain not hierarchical;                                                                                                                                                                                                                                                                                                                                                                                                                                        |  |                 |           |                        |                |                        |                                 |                           |                          |                        |                                   |                      |                      |
+| X_CON_PV_LOWER_LAY_DIS    | Lower layer initiated disconnect;                                                                                                                                                                                                                                                                                                                                                                                                                               |  |                 |           |                        |                |                        |                                 |                           |                          |                        |                                   |                      |                      |
+| X_CON_PV_UNSPECIFIED      | Unspecified failure.                                                                                                                                                                                                                                                                                                                                                                                                                                            |  |                 |           |                        |                |                        |                                 |                           |                          |                        |                                   |                      |                      |
+| Default value             | X_CON_PV_ACCEPT                                                                                                                                                                                                                                                                                                                                                                                                                                                 |  |                 |           |                        |                |                        |                                 |                           |                          |                        |                                   |                      |                      |
+| Description               | This parameter indicates the success or failure of the Conference Query service.                                                                                                                                                                                                                                                                                                                                                                                |  |                 |           |                        |                |                        |                                 |                           |                          |                        |                                   |                      |                      |
+
+### I.6.7.5.2 Conference Conductor Inquire service
+
+This service may be issued to find out whether the conference is conducted or not. If so, further information is given:
+
+- which node is the conductor;
+- if the requesting node has been granted conducted-mode permission.
+
+This service is available to the user only in the connected state of the XAPI.
+
+#### I.6.7.5.2.1 Service description
+
+The service elements and their corresponding XAPI functions needed for the Conductor Inquire service are described Table I.6-56.
+
+**Table I.6-56/T.180 – Service elements and their corresponding XAPI functions for the Conductor Inquire service**
+
+| Service element                | Service element identifier | XAPI function | Description                                                                                        |
+|--------------------------------|----------------------------|---------------|----------------------------------------------------------------------------------------------------|
+| Conductor Inquire Request      | X_COND_INQUIRE_Q           | x_sndinfo()   | The Information Request is passed to the provider to request the information about the conductor.  |
+| Conductor Inquire Confirmation | X_COND_INQUIRE_C           | x_rcvinfo()   | The Information Confirmation is a positive or negative response to a previous information request. |
+
+#### I.6.7.5.2.2 Service parameters
+
+Table I.6-57 specifies the parameters of the conference Conductor Inquire service.
+
+**Table I.6-57/T.180 – Parameter of the Conductor Inquire service**
+
+| Parameter          | Conference Conductor Inquire service |              |
+|--------------------|--------------------------------------|--------------|
+|                    | Request                              | Confirmation |
+| X_CON_P_CONDUCTED  |                                      | M            |
+| X_CON_P_COND_NODE  |                                      | C            |
+| X_CON_P_PERMISSION |                                      | C            |
+
+#### I.6.7.5.2.3 Service parameter description
+
+Tables I.6-58 to I.6-60 specify the parameters of the Conductor Inquire service.
+
+**Table I.6-58/T.180**
+
+|                |                                                                                                  |
+|----------------|--------------------------------------------------------------------------------------------------|
+| Parameter name | X_CON_P_CONDUCTED                                                                                |
+| Type of value  | unsigned long                                                                                    |
+| Legal values   | PV_TRUE<br>PV_FALSE                                                                              |
+| Default value  | PV_FALSE                                                                                         |
+| Description    | This parameter indicates whether the conference is currently in conducted or non-conducted mode. |
+
+**Table I.6-59/T.180**
+
+|                |                                                                                                                                            |
+|----------------|--------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_CON_P_COND_NODE                                                                                                                          |
+| Type of value  | unsigned long                                                                                                                              |
+| Legal values   | an integer between 1001 and 65 535                                                                                                         |
+| Default value  | none                                                                                                                                       |
+| Description    | This parameter indicates the node ID of the current conference conductor. It is only available if the conference is in the conducted mode. |
+
+**Table I.6-60/T.180**
+
+|                |                                                                                                                                                |
+|----------------|------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_CON_P_PERMISSION                                                                                                                             |
+| Type of value  | unsigned long                                                                                                                                  |
+| Legal values   | PV_TRUE<br>PV_FALSE                                                                                                                            |
+| Default value  | none                                                                                                                                           |
+| Description    | This parameter indicates if the conference is in the conducted mode, whether or not the local node has been granted conducted mode permission. |
+
+### **I.6.7.5.3 Conference Roster Report service**
+
+This service informs the user, in the case when the conference roster has changed for any reason. This service is available to the user only in the connected state of the XAPI.
+
+#### **I.6.7.5.3.1 Service description**
+
+The service element and their corresponding XAPI function needed for the Conference Roster Report service are described in Table I.6-61.
+
+**Table I.6-61/T.180 – Service element and their corresponding XAPI function for the Conference Roster Report service**
+
+| Service element              | Service element identifier | XAPI function | Description                                                                  |
+|------------------------------|----------------------------|---------------|------------------------------------------------------------------------------|
+| Conference Roster Indication | X_CON_C_REP_I              | x_revinfo()   | The service informs the user in the case when the Conference Roster changes. |
+
+#### **I.6.7.5.3.2 Service parameter**
+
+Table I.6-62 specifies the parameter of the Conference Roster Report service.
+
+**Table I.6-62/T.180 – Parameter of the Conference Roster Report service**
+
+| Parameter       | Conference Roster Service |
+|-----------------|---------------------------|
+|                 | Indication                |
+| X_CON_P_CROSTER | M                         |
+
+### I.6.7.5.3.3 Service parameter description
+
+Table I.6-63 specifies the parameter of the Conference Roster Report service.
+
+**Table I.6-63/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                            |                                                                        |                                        |
+|----------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------|----------------------------------------|
+| Parameter name | X_CON_P_CROSTER                                                                                                                                                                                                                                                                                                                                            |                                                                        |                                        |
+| Type of value  | typedef struct Conference {<br>unsigned long               NodeID;<br>unsigned long               Node_Type;<br>string                      Node_Name;<br>sequence<string<255> >    Part_List;<br>string                      Site_Info;<br>string                      Net_Addr;<br>string                      User_Data;<br>};<br>sequence<Conference>; |                                                                        |                                        |
+| Legal values   | NodeID                                                                                                                                                                                                                                                                                                                                                     | A number in the range 1 001 to 65 535;                                 |                                        |
+|                | Node_Type                                                                                                                                                                                                                                                                                                                                                  | X_CON_PV_TERMINAL,<br>X_CON_PV_MULTIPORT_TERMINAL,<br>or X_CON_PV_MCU; |                                        |
+|                | Node_Name                                                                                                                                                                                                                                                                                                                                                  | A text string;                                                         |                                        |
+|                | Part_List                                                                                                                                                                                                                                                                                                                                                  | A list of text strings                                                 | Participants' names;                   |
+|                | Site_Info                                                                                                                                                                                                                                                                                                                                                  | A text string                                                          | Additional information about the node; |
+|                | Net_Addr                                                                                                                                                                                                                                                                                                                                                   | A text string                                                          | Network Address;                       |
+|                | User_Data                                                                                                                                                                                                                                                                                                                                                  | A text string                                                          | Additional user data.                  |
+| Default value  | none                                                                                                                                                                                                                                                                                                                                                       |                                                                        |                                        |
+| Description    | This parameter contains a description of each node joined to the conference. The parameters Node Name, Participants Names, Site Information, Network Address, and User Data in the List of Conference Nodes are conditional.                                                                                                                               |                                                                        |                                        |
+
+### I.6.7.5.4 Application Roster Report service
+
+This service informs the user in the case when a application roster has changed. This service is available to the user only in the connected state of the XAPI.
+
+#### I.6.7.5.4.1 Service description
+
+The service element and their corresponding XAPI function needed for the Application Roster Report service are described in Table I.6-64.
+
+**Table I.6-64/T.180 – Service element and their corresponding XAPI function for the Application Roster Report service**
+
+| Service Element               | Service element identifier | XAPI function | Description                                                                                                                                                                                                 |
+|-------------------------------|----------------------------|---------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Application Roster Indication | X_CON_A_REP_I              | x_revinfo()   | The Service informs the user in the case when the Application Roster changes. The Application Roster Indication is generated by the provider to support a session member with session-specific information. |
+
+#### I.6.7.5.4.2 Service parameter
+
+Table I.6-65 specifies the parameters of the Application Roster Report service.
+
+**Table I.6-65/T.180 – Parameter of the Application Roster Report service**
+
+| Parameter       | Application Roster Service |
+|-----------------|----------------------------|
+|                 | Indication                 |
+| X_CON_P_AROSTER | M                          |
+
+#### I.6.7.5.4.3 Service parameter description
+
+Table I.6-66 specifies the parameter of the Application Roster Report service.
+
+**Table I.6-66/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
+|----------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_CON_P_AROSTER                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
+| Type of value  | <pre> typedef struct ApplicationRecord {     unsigned long    NodeID;     unsigned long    EntityID;     unsigned long    Active;     unsigned long    Cond_Cap;     string           UserApplicationID;     sequence&lt;string&gt; NCollapsCapsList; };  typedef struct ApplicationCapability {     unsigned long    CapabilityID;     unsigned long    CapabilityValue; };  typedef struct Session{     string                                     ApplicationProtocolKey;     unsigned long                                SessionID;     sequence&lt;ApplicationRecord&gt; ApplicationRecordList;     sequence&lt;ApplicationCapability&gt; ApplicationCapabilityList; };  sequence&lt;Session&gt;; </pre> |
+
+**Table I.6-66/T.180 (concluded)**
+
+|               |                                                                                    |                                                                   |
+|---------------|------------------------------------------------------------------------------------|-------------------------------------------------------------------|
+| Legal values  | NodeID                                                                             | A number in the range 1 001 to 65 535                             |
+|               | EntityID                                                                           | A 16-bit numeric identifier                                       |
+|               | Active                                                                             | PV_TRUE / PV_FALSE Ready to receive data;                         |
+|               | Cond_Cap                                                                           | PV_TRUE / PV_FALSE Conducting capable;                            |
+|               | UserApplicationID                                                                  | A text string Identifies the conference control user application; |
+|               | NCollapsCapsList                                                                   | A list of text strings Non-collapsing capabilities;               |
+|               | CapabilityID                                                                       | A number Identifies an application capability;                    |
+|               | CapabilityValue                                                                    | A number Dependent from the capability class;                     |
+|               | ApplicationProtocolKey                                                             | A text string Identifies the GCC protocol;                        |
+|               | SessionID                                                                          | A number in the range 1 to 65 535.                                |
+| Default value | none                                                                               |                                                                   |
+| Description   | The Application Roster includes a list of roster entries for all Protocol Session. |                                                                   |
+
+### I.6.7.5.5 Conductor Report service
+
+#### I.6.7.5.5.1 Service description
+
+The service element and their corresponding XAPI function needed for the Conductor Report service are described in Table I.6-67.
+
+**Table I.6-67/T.180 – Service element and their corresponding XAPI function for the Conductor Report service**
+
+| Service element             | Service element identifier | XAPI function | Description                                                                                               |
+|-----------------------------|----------------------------|---------------|-----------------------------------------------------------------------------------------------------------|
+| Conductor Report Indication | X_CON_COND_INFO            | x_rcvinfo()   | The service informs the user in the case when information is received about changes in the conductorship. |
+
+#### I.6.7.5.5.2 Service parameters
+
+Table I.6-68 specifies the parameters of the Conductor Report service.
+
+**Table I.6-68/T.180 – Parameters of the Conductor Report service**
+
+| Parameter         | Conductor Service |
+|-------------------|-------------------|
+|                   | Indication        |
+| X_CON_P_COND_MODE | M                 |
+| X_CON_P_REQ_NODE  | C                 |
+
+#### I.6.7.5.5.3 Service parameter description
+
+Tables I.6-69 and I.6-70 specify the parameters of the Conductor Report service.
+
+**Table I.6-69/T.180**
+
+|                |                                                                                                                              |
+|----------------|------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_CON_P_COND_MODE                                                                                                            |
+| Type of value  | unsigned long                                                                                                                |
+| Legal values   | PV_TRUE<br>PV_FALSE                                                                                                          |
+| Default value  | PV_FALSE                                                                                                                     |
+| Description    | This parameter indicates that the conference is now in the conducted mode (PV_TRUE) or in the non-conducted mode (PV_FALSE). |
+
+**Table I.6-70/T.180**
+
+|                |                                                                                                                                                                                            |
+|----------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_CON_P_REQ_NODE                                                                                                                                                                           |
+| Type of value  | unsigned long                                                                                                                                                                              |
+| Legal values   | an integer between 1001 and 65 535                                                                                                                                                         |
+| Default value  | none                                                                                                                                                                                       |
+| Description    | This parameter is used to indicate the node identification of the conductor. This parameter is only meaningful when the conference is in the conducted mode (X_CON_P_COND_MODE = PV_TRUE). |
+
+### **I.6.7.6 Tables of error codes**
+
+The XAPI error-level error codes are defined in Annex B.
+
+#### **I.6.7.6.1 CC\_BADVALUE**
+
+If the cause code indicates a parameter error with a bad value, the value of *diagnostic* will contain the erroneous parameter identifier which has been submitted with the XAPI function call that caused the error indication or one of the identifiers X\_ACS\_CTX\_DEF\_LIST, X\_ACS\_CTX\_DEF\_RES\_LIST, X\_ACS\_CTX\_ID\_LIST, if the error occurred within a context definition list, context definition result list or context identifier list, respectively.
+
+#### **I.6.7.6.2 CC\_MANDMISS**
+
+If the cause code indicates a mandatory parameter is missing, the value of *diagnostic* will contain the missing parameter identifier that caused the error indication.
+
+#### **I.6.7.6.3 CC\_BADEVENT**
+
+If the cause code indicates a bad event, the value of *diagnostic* will contain the bad event identifier which has been submitted with the XAPI function call that caused the error indication.
+
+#### **I.6.7.6.4 CC\_UNEXPECT**
+
+If the cause code indicates an unexpected event, the value of *diagnostic* will contain the actual state identifier in which the unexpected event caused the error indication.
+
+#### **I.6.7.6.5 CC\_NOTSUPPORT**
+
+If the cause code indicates an unsupported event, the value of *diagnostic* will contain the identifier of the unsupported event which has been submitted with the XAPI function call that caused the error indication.
+
+#### **I.6.7.6.6 CC\_OTHER**
+
+If the cause code indicates the CC\_OTHER error code, the value of *diagnostic* will contain the identifier which caused the error indication.
+
+### **I.7 XAPI access to the service provider for T.127 MBFT**
+
+This part of Appendix I describes an example how the service provider can be implemented, if an application needs access to the specified service.
+
+#### **I.7.1 Scope**
+
+The XAPI, which is an abbreviation for eXtensive Application Programming Interface, is an operating system and language-independent programming interface to general communication services. Detailed information about the XAPI is given in the main part of this Recommendation, which is very important for understanding this appendix.
+
+Which services are made available via the XAPI depends on the installed service providers and not on the XAPI, which only provides the access mechanism.
+
+This part describes the XAPI access to the Multipoint Binary File Transfer (MBFT) Protocol. The MBFT protocol is specified in Recommendation T.127.
+
+Figure I.7-1 shows the structure of the protocol stack that is accessible via the XAPI when selecting the MBFT service provider.
+
+![Figure I.7-1/T.180 – Structure of the T.127 MBFT service provider. The diagram shows a vertical stack of components. At the top is 'Application'. Below it is 'XAPI'. Below 'XAPI' is 'T.127 MBFT protocol module'. Below that is a large box labeled 'Conference provider (without node controller and application protocols)'. Inside this box, from top to bottom, are: 'T.124 GCC protocol module', 'T.125 MCS protocol module', and 'T.123 network-specific transport protocol module'. Bidirectional arrows connect 'Application' to 'XAPI', 'XAPI' to 'T.127 MBFT protocol module', 'T.127 MBFT protocol module' to 'T.124 GCC protocol module', 'T.124 GCC protocol module' to 'T.125 MCS protocol module', and 'T.125 MCS protocol module' to 'T.123 network-specific transport protocol module'. Additionally, a bidirectional arrow connects 'T.127 MBFT protocol module' directly to 'T.125 MCS protocol module'.](28583b06f211df822423d245dfad776f_img.jpg)
+
+```
+
+graph TD
+    Application[Application] <--> XAPI[XAPI]
+    XAPI <--> T127[T.127 MBFT protocol module]
+    subgraph Conference_provider [Conference provider  
+(without node controller and application protocols)]
+        T124[T.124 GCC protocol module]
+        T125[T.125 MCS protocol module]
+        T123[T.123 network-specific transport protocol module]
+        T124 <--> T125
+        T125 <--> T123
+    end
+    T127 <--> T124
+    T127 <--> T125
+
+```
+
+T0827340-97
+
+Figure I.7-1/T.180 – Structure of the T.127 MBFT service provider. The diagram shows a vertical stack of components. At the top is 'Application'. Below it is 'XAPI'. Below 'XAPI' is 'T.127 MBFT protocol module'. Below that is a large box labeled 'Conference provider (without node controller and application protocols)'. Inside this box, from top to bottom, are: 'T.124 GCC protocol module', 'T.125 MCS protocol module', and 'T.123 network-specific transport protocol module'. Bidirectional arrows connect 'Application' to 'XAPI', 'XAPI' to 'T.127 MBFT protocol module', 'T.127 MBFT protocol module' to 'T.124 GCC protocol module', 'T.124 GCC protocol module' to 'T.125 MCS protocol module', and 'T.125 MCS protocol module' to 'T.123 network-specific transport protocol module'. Additionally, a bidirectional arrow connects 'T.127 MBFT protocol module' directly to 'T.125 MCS protocol module'.
+
+**Figure I.7-1/T.180 – Structure of the T.127 MBFT service provider**
+
+The MBFT service provider consists of the T.127 MBFT protocol module, the T.124 GCC protocol module, the T.125 MCS protocol module, and the T.123 Network-specific transport protocol stack modules.
+
+The conference provider comprises the T.124 GCC protocol module, the T.125 MCS protocol module, the T.123 Network-specific transport protocol stack modules, the node controller module, and the application protocol modules (e.g. the T.127 MBFT protocol module).
+
+All modules of the conference provider – with the exception of the application protocol modules – are initialized and activated, when the user (at the terminal) is connected to a conference.
+
+Afterwards, applications may be connected to the conference. The location of an application protocol module is shown in Figure I.7-1: each application protocol uses the protocol stack which was initialized and activated in the phase, when a terminal was connected to the conference (see I.6, XAPI access to the T.120 conference control provider).
+
+The reader should be familiar with the T.120 suite of standards (see References).
+
+## I.7.2 References
+
+The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; all users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published.
+
+- [T.120] ITU-T Recommendation T.120 (1996), *Data protocols for multimedia conferencing*.
+- [T.121] ITU-T Recommendation T.121 (1996), *Generic application template*.
+- [T.122] ITU-T Recommendation T.122 (1998), *Multipoint communication service – Service definition*.
+- [T.123] ITU-T Recommendation T.123 (1996), *Network specific data protocol stacks for multimedia conferencing*.
+- [T.124] ITU-T Recommendation T.124 (1998), *Generic Conference Control*.
+- [T.125] ITU-T Recommendation T.125 (1994), *Multipoint communication service protocol specification*.
+- [T.127] ITU-T Recommendation T.127 (1995), *Multipoint binary file transfer protocol*.
+
+## I.7.3 Definitions
+
+This part defines the following terms:
+
+**I.7.3.1 application:** Synonymously used for User Application.
+
+**I.7.3.2 application protocol entity:** The instantiation of an Application Protocol in a terminal. Application Protocol Entities are employed by User Applications, but are not themselves User Applications.
+
+**I.7.3.3 application protocol module:** Synonymously used for Application Protocol Entity.
+
+**I.7.3.4 application record:** A set of information for a specific Application Protocol Entity at a specific node.
+
+**I.7.3.5 session:** A set of peer Application Protocol Entities.
+
+A group of file transfer applications communicating with each other are said to be participating in the same file transfer session.
+
+**I.7.3.6 MBFT specific transaction:** A sequence of one or more actions (i.e. sending and receiving MBFT PDUs, MCS PDUs, and GCC PDUs respectively) which are needed to distribute a file.
+
+**I.7.3.7 user application:** An entity which makes use of one or more Application Protocol Entities. User Applications have access to an Application Protocol Entity via the XAPI.
+
+## I.7.4 Abbreviations
+
+This part uses the following abbreviations:
+
+- APE Application Protocol Entity
+- BFT Binary File Transfer
+- GCC Generic Conference Control
+- MCS Multipoint Communication Service
+
+MBFT Multipoint Binary File Transfer  
+PDU Protocol Data Unit  
+SP Service Primitive  
+XAPI eXtensive Application Programming Interface
+
+### 1.7.5 Conventions
+
+Each service is described via three kinds of tables. The kind of description is derived from the kind of service and protocol description within OSI Standards.
+
+In the first kind of table the service and its service elements are described. It contains a row for each service element of the service (where service element means either request, indication, response, or confirmation) with its corresponding XAPI function and a short description.
+
+In the second kind of table the use of the service primitive parameters within the service elements are described. It contains a row for each service primitive parameter of the service. The service primitive parameter name is stored within the first column; the succeeding columns contain the use of the parameter in the service elements:
+
+Blank The service parameter is absent.
+
+C Presence of the service parameter is conditional. Firstly, there may be a condition in the service provider to provide a parameter in an indication or confirmation; secondly, there may be interdependencies between parameters of the same or the preceding service primitive.
+
+M Presence of the service parameter is mandatory.
+
+U Presence of the service parameter is a user option. If the user does not specify a value for such a parameter and there is no default value for that parameter, nothing is passed to the service provider. If the user does not specify a value for such a parameter and there is a default value, the default value is passed to the service provider.
+
+(=) The value of the service parameter is identical to the value of the corresponding service parameter in the preceding service element. In the special case of a parameter, whose presence in the preceding service is a user option, for which a default value is defined, and the parameter was not specified in the preceding service element, the symbol (=) indicates that the parameter value is identical to the default value.
+
+The third kind of table is used to describe the service primitive parameter containing the type of value and its scope, possible default values and a detailed description. For each service primitive parameter, one description table is given.
+
+A **naming convention** is used throughout the XAPI in order to distinguish between the common functions, identifiers and values, and service-specific identifiers and values. All service-specific settings of the T.127 MBFT service provider access are defined within the present part of this appendix and start with **X\_MBF\_** or **x\_mbf\_**.
+
+Extended naming conventions:
+
+- SP\_ Service Primitive;
+- P\_ Parameter;
+- PV\_ Parameter Value;
+- O\_ Option;
+- OV\_ Option Value.
+
+## **I.7.6 Introduction to the MBFT service provider access**
+
+The T.127 MBFT Protocol [T.127] supports the interchange of binary files within an interactive conferencing or group working environment where the [T.120] series of Recommendations is in use. It provides mechanisms for:
+
+- simultaneous distribution of multiple files;
+- broadcasting of files to all participants within a conference;
+- selective distribution of files to a subset of participants;
+- conductor control of file distribution;
+- retrieval of files from remote sites;
+- partial retransmission of files following an interruption;
+- remote directory access.
+
+The following services of the above specified groups are supported:
+
+- simultaneous distribution of multiple files;
+- broadcasting of files to all participants within a conference;
+- selective distribution of files to a subset of participants;
+- conductor control of file distribution.
+
+A file transfer user application initiates a file transfer session via its MBFT protocol entity, specifying the application capabilities and session mode. Once a session has been established, all MBFT specific transactions are performed by the MBFT protocol entity on behalf of the user application.
+
+## **I.7.7 Description of the access to the MBFT service provider**
+
+### **I.7.7.1 Service initialization**
+
+#### **I.7.7.1.1 Creation of a T.127 MBFT service access point with *x\_open()***
+
+A communication endpoint accessing the T.127 MBFT service provider is created when calling the *x\_open()* function with an appropriate service provider identification string. The available identifiers depend on the actual system configuration. In the standard configuration, "**X\_T.127\_MBFT**" identifies the T.127 MBFT protocol module.
+
+#### **I.7.7.1.2 Activation of a T.127 MBFT service access point with *x\_bind()***
+
+*x\_bind()* is to be called to activate the T.127 MBFT service endpoint. The function has the task to bind the application's own address to the service endpoint.
+
+In the standard configuration, if "**X\_T.127\_MBFT**" was selected in the *x\_open()* function, a suitable conference system, for example "**X\_T.120\_CONF\_ISDN**" has to be specified as argument of the *x\_bind()* function in order to complete the service provider's protocol stack.
+
+Figure I.7-1 illustrates the protocol modules contained in **X\_T.120\_CONF\_PRO**.
+
+#### **I.7.7.1.3 Addresses**
+
+Prior to connecting an application to a conference, the user has to become a participant within a conference. The address information, which is needed to identify a node within a conference is handled in this early phase (i.e. in the phase of creating or joining a conference). Therefore, binding the application's own address to the service endpoint will rely on this information.
+
+#### I.7.7.1.3.1 Specification of the application's own address
+
+No specific address is in use when activating the service endpoint.
+
+No other parameters are needed.
+
+It is strongly recommended to trust in the XAPI configuration and not to specify the own address or other parameters in the *x\_bind()* call.
+
+#### I.7.7.1.3.2 The address of the communication partner
+
+This parameter has been provided by the conference connection establishment phase [T.124].
+
+#### I.7.7.1.4 Configuration of the service provider
+
+Protocol options are used to control the general behaviour of the service provider. There is a default value defined for each option. These preconfigured values are sufficient for the majority of communication relations.
+
+XAPI enables applications to express their wishes about the settings of protocol options by using the XAPI function *x\_optmgmt()*.
+
+Tables I.7-1 to I.7-8 define the protocol options.
+
+**Table I.7-1/T.180**
+
+|               |                                                                                                                                                                                  |
+|---------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Option name   | X_MBF_O_M_TYPE                                                                                                                                                                   |
+| Type of value | unsigned long                                                                                                                                                                    |
+| Legal values  | X_MBF_OV_RCV_ONLY File Receive Only MBFT Protocol module<br>X_MBF_OV_SND_ONLY File Send Only MBFT Protocol module<br>X_MBF_OV_SND_RCV File Receive and Send MBFT Protocol module |
+| Default value | none                                                                                                                                                                             |
+| Attributes    |                                                                                                                                                                                  |
+| Description   | Indicates the type of the T.127 MBFT protocol module.                                                                                                                            |
+
+**Table I.7-2/T.180**
+
+|               |                                                                                                                                                        |
+|---------------|--------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Option name   | X_MBF_O_MAX_FILE_SIZE                                                                                                                                  |
+| Type of value | unsigned long                                                                                                                                          |
+| Legal values  | X_MBF_OV_FS_UNLIM Unlimited;<br>X_MBF_OV_FS_MAX_VAL Maximum file data payload in octets.                                                               |
+| Default value | X_MBF_OV_FS_UNLIM                                                                                                                                      |
+| Description   | Indicates the maximum file size. Each T.127 MBFT protocol module must specify the maximum file data payload in octets that it is capable of receiving. |
+
+**Table I.7-3/T.180**
+
+|               |                                                                                                                                       |
+|---------------|---------------------------------------------------------------------------------------------------------------------------------------|
+| Option name   | X_MBF_O_MAX_DAT_PAYL                                                                                                                  |
+| Type of value | unsigned long                                                                                                                         |
+| Legal values  | X_MBF_OV_DP_DEF      Default value (8192 octets);<br>X_MBF_OV_DP_MAX_VAL      Maximum number (less or equal 65 536 octets).           |
+| Default value | X_MBF_OV_DP_DEF                                                                                                                       |
+| Description   | Indicates the maximum data payload. This is the maximum number of octets allowed in the data field of T.127 MBFT start and data PDUs. |
+
+**Table I.7-4/T.180**
+
+|               |                                                                                                                                |
+|---------------|--------------------------------------------------------------------------------------------------------------------------------|
+| Option name   | X_MBF_O_COMPR                                                                                                                  |
+| Type of value | unsigned long                                                                                                                  |
+| Legal values  | PV_TRUE<br>PV_FALSE                                                                                                            |
+| Default value | PV_FALSE                                                                                                                       |
+| Attributes    |                                                                                                                                |
+| Description   | Compresses files before being transferred. When actually transferring files, it is possible to select or deselect this option. |
+
+**Table I.7-5/T.180**
+
+|               |                                                                                                                                                          |
+|---------------|----------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Option name   | X_MBF_O_NB_OF_CWOR                                                                                                                                       |
+| Type of value | unsigned long                                                                                                                                            |
+| Legal values  | X_MBF_OV_CW_DEF      Default value (512 codewords);<br>X_MBF_OV_CW_NUM      Total number of codewords (less or equal 65 536).                            |
+| Default value | X_MBF_OV_CW_DEF                                                                                                                                          |
+| Description   | Specifies the total number of codewords to be used by the V.42 <i>bis</i> compression algorithm. This is an upper bound on V.42 <i>bis</i> parameter P1. |
+
+**Table I.7-6/T.180**
+
+|               |                                                                                                                                   |
+|---------------|-----------------------------------------------------------------------------------------------------------------------------------|
+| Option name   | X_MBF_O_MAX_STR_LNGH                                                                                                              |
+| Type of value | unsigned long                                                                                                                     |
+| Legal values  | X_MBF_OV_STR_DEF      Default value (6);<br>X_MBF_OV_STR_VAL      Maximum string length (less or equal 250).                      |
+| Default value | X_MBF_OV_STR_DEF                                                                                                                  |
+| Description   | Specifies the maximum string length input to the V.42 <i>bis</i> encoder. This is an upper bound on V.42 <i>bis</i> parameter P2. |
+
+
+
+**Table I.7-9/T.180 – Service elements and their corresponding XAPI functions for Connection Establishment**
+
+| Service element      | XAPI function | Description                                                                                                                                                                                                   |
+|----------------------|---------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Connect Request      | x_conreq()    | The Connect Request is passed to the provider to request the establishment of an connection for file transfer purposes.                                                                                       |
+| Connect Confirmation | x_conconf()   | The Connect Confirmation is generated by the provider as positive or negative response to a previous connection establishment request. A positive confirmation indicates that the provider accepted the call. |
+
+### I.7.7.2.2 Service parameters
+
+Table I.7-10 specifies the parameters of the Connection Establishment service.
+
+There are two groups of parameters: the parameters which specify general aspects of a MBFT session and the MBFT service provider capability parameters.
+
+The parameters specifying general aspects of a MBFT session are:
+
+- the user application ID;
+- the conference name;
+- the session name;
+- whether or not the provider should support the conductor role;
+- the type of activity: transmit files only, receive files only, transmit and receive files; files which are neither transmitted nor received (application inactive);
+- the actual list of participants in the session.
+
+The specification of provider capabilities is optional. If a capability parameter is not specified in a service element, the default value will be used by the service provider. The default value itself is defined by the value of a protocol option. For each capability parameter there is a corresponding protocol option which defines the default value for this parameter. For the protocol option, a constant default value is defined in the XAPI configuration.
+
+**Table I.7-10/T.180 – Parameters of the Connection Establishment service**
+
+| Parameter             | Connect Service |              |
+|-----------------------|-----------------|--------------|
+|                       | Request         | Confirmation |
+| X_MBF_P_CNAME         | M               | M(=)         |
+| X_MBF_P_CNAME_M       | C               | C(=)         |
+| X_MBF_P_SESS_TYPE     | M               | M            |
+| X_MBF_P_SESS_ID       | U               | M            |
+| X_MBF_P_LIST_OF_MEMB  | U               |              |
+| X_MBF_P_USER_APP_ID   | U               |              |
+| X_MBF_P_COND_OP_CAP   | U               |              |
+| X_MBF_P_M_MODE        | U               | M            |
+| X_MBF_P_MAX_FILE_SIZE | U               | C            |
+
+**Table I.7-10/T.180 – Parameters of the Connection Establishment service (concluded)**
+
+| Parameter            | Connect Service |              |
+|----------------------|-----------------|--------------|
+|                      | Request         | Confirmation |
+| X_MBF_P_MAX_DAT_PAYL | U               | C            |
+| X_MBF_P_COMPR        | U               | C            |
+| X_MBF_P_NB_OF_CWOR   | U               | C            |
+| X_MBF_P_MAX_STR_LNGH | U               | C            |
+| X_MBF_P_NON_STD_CAP  | C               | C            |
+| X_MBF_P_NODE_ID      |                 | C            |
+| X_MBF_P_ENTITY_ID    |                 | C            |
+| X_MBF_P_RESULT       |                 | M            |
+
+**I.7.7.2.3 Service parameter descriptions**
+
+Tables I.7-11 to I.7-27 describe the parameters for the Connection Establishment service.
+
+**Table I.7-11/T.180**
+
+|                |                                                                                                                       |
+|----------------|-----------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_MBF_P_CNAME                                                                                                         |
+| Type of value  | <pre> struct X_MBF_P_CNAME {     string&lt;256&gt;    numeric_string;     string&lt;256&gt;    text_string; }; </pre> |
+| Legal values   | a numerical string along with an optional text string, from zero to 255 characters each                               |
+| Default value  | none                                                                                                                  |
+| Description    | Name by which the conference is identified.                                                                           |
+
+**Table I.7-12/T.180**
+
+|                |                                                                                                                    |
+|----------------|--------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_MBF_P_CNAME_M                                                                                                    |
+| Type of value  | string<255>                                                                                                        |
+| Legal values   | a numerical string up to 255 digits in length                                                                      |
+| Default value  | none                                                                                                               |
+| Description    | Name Modifier by which the conference is identified if a conference with identical conference name already exists. |
+
+**Table I.7-13/T.180**
+
+|                |                                                                                                                                                                                                                 |
+|----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_MBF_P_SESS_TYPE                                                                                                                                                                                               |
+| Type of value  | unsigned long                                                                                                                                                                                                   |
+| Legal values   | X_MBF_PV_SESS_REG Registration session;<br>X_MBF_PV_SESS_STD Standard Base session;<br>X_MBF_PV_SESS_NSTD Non-Standard base session;<br>X_MBF_PV_SESS_PUB Public session;<br>X_MBF_PV_SESS_PRI Private session. |
+| Default value  | X_MBF_PV_SESS_STD                                                                                                                                                                                               |
+| Description    | Parameter by which the session type is identified.                                                                                                                                                              |
+
+**Table I.7-14/T.180**
+
+|                |                                   |
+|----------------|-----------------------------------|
+| Parameter name | X_MBF_P_SESS_ID                   |
+| Type of value  | unsigned long                     |
+| Legal values   | a number in the range 1 to 65 535 |
+| Default value  | none                              |
+| Description    | Session Identifier.               |
+
+**Table I.7-15/T.180**
+
+|                |                                                                                                  |
+|----------------|--------------------------------------------------------------------------------------------------|
+| Parameter name | X_MBF_P_LIST_OF_MEMB                                                                             |
+| Type of value  | sequence<unsigned long>                                                                          |
+| Legal values   | a list of numbers in the range 1001 to 65 535                                                    |
+| Default value  | none                                                                                             |
+| Description    | This parameter is used to invite participants (specified by their NodeIDs) to a private session. |
+
+**Table I.7-16/T.180**
+
+|                |                              |
+|----------------|------------------------------|
+| Parameter name | X_MBF_P_USER_APP_ID          |
+| Type of value  | string                       |
+| Legal values   | a text string                |
+| Default value  | none                         |
+| Description    | User Application Identifier. |
+
+**Table I.7-17/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
+|----------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_MBF_P_COND_OP_CAP                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
+| Type of value  | unsigned long                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
+| Legal values   | PV_TRUE<br>PV_FALSE                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
+| Default value  | PV_FALSE                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
+| Description    | The Conducting Operation Capable parameter indicates whether the MBFT Protocol module is capable of operating as a session conductor. Each MBFT Session has its own conductor, namely the MBFT Protocol module at the conducting node participating in that Session. If there is more than one MBFT Protocol module at the conducting node in a given MBFT Session, then it is a local matter for GCC at the conducting node to decide which MBFT Protocol module adopts the role of session conductor. |
+
+**Table I.7-18/T.180**
+
+|                |                                                                                                                                                                                                                                                                   |
+|----------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_MBF_P_M_MODE                                                                                                                                                                                                                                                    |
+| Type of value  | unsigned long                                                                                                                                                                                                                                                     |
+| Legal values   | X_MBF_PV_MM_REC                      Receive files only;<br>X_MBF_PV_MM_SND                      Transmit files only;<br>X_MBF_PV_MM_SND_REC                Transmit and receive files;<br>X_MBF_PV_MM_N_SND_REC              Neither transmit nor receive files. |
+| Default value  | none                                                                                                                                                                                                                                                              |
+| Description    | Indicates the T.127 MBFT protocol module mode. It is dependent from the protocol option X_MBF_O_M_TYPE.                                                                                                                                                           |
+
+**Table I.7-19/T.180**
+
+|                |                                                                                                                                                        |
+|----------------|--------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_MBF_P_MAX_FILE_SIZE                                                                                                                                  |
+| Type of value  | unsigned long                                                                                                                                          |
+| Legal values   | X_MBF_PV_FS_UNLIM                    Unlimited;<br>X_MBF_PV_FS_MAX_VAL                Maximum file data payload in octets.                             |
+| Default value  | X_MBF_PV_FS_UNLIM                                                                                                                                      |
+| Description    | Indicates the maximum file size. Each T.127 MBFT protocol module must specify the maximum file data payload in octets that it is capable of receiving. |
+
+**Table I.7-20/T.180**
+
+|                |                                                                                                                                                       |
+|----------------|-------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_MBF_P_MAX_DAT_PAYL                                                                                                                                  |
+| Type of value  | unsigned long                                                                                                                                         |
+| Legal values   | X_MBF_PV_DP_DEF                      Default value (8192 octets);<br>X_MBF_PV_DP_MAX_VAL                Maximum number (less or equal 65 536 octets). |
+| Default value  | X_MBF_PV_DP_DEF                                                                                                                                       |
+| Description    | Indicates the maximum data payload. This is the maximum number of octets allowed in the data field of T.127 MBFT start and data PDUs.                 |
+
+**Table I.7-21/T.180**
+
+|                |                                                                                                                                                                                                              |
+|----------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_MBF_P_COMPR                                                                                                                                                                                                |
+| Type of value  | unsigned long                                                                                                                                                                                                |
+| Legal values   | PV_TRUE<br>PV_FALSE                                                                                                                                                                                          |
+| Default value  | PV_FALSE                                                                                                                                                                                                     |
+| Description    | This parameter is used to negotiate use of V.42 <i>bis</i> compression for file data. T.127 MBFT protocol modules should assert this capability if they are able to receive V.42 <i>bis</i> compressed data. |
+
+**Table I.7-22/T.180**
+
+|                |                                                                                                                                                          |
+|----------------|----------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_MBF_P_NB_OF_CWOR                                                                                                                                       |
+| Type of value  | unsigned long                                                                                                                                            |
+| Legal values   | X_MBF_PV_CW_DEF Default value (512 codewords);<br>X_MBF_PV_CW_NUM Total number of codewords (less or equal 65 536).                                      |
+| Default value  | X_MBF_PV_CW_DEF                                                                                                                                          |
+| Description    | Specifies the total number of codewords to be used by the V.42 <i>bis</i> compression algorithm. This is an upper bound on V.42 <i>bis</i> parameter P1. |
+
+**Table I.7-23/T.180**
+
+|                |                                                                                                                                   |
+|----------------|-----------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_MBF_P_MAX_STR_LNGH                                                                                                              |
+| Type of value  | unsigned long                                                                                                                     |
+| Legal values   | X_MBF_PV_STR_DEF Default value (6);<br>X_MBF_PV_STR_VAL Maximum string length (less or equal 250).                                |
+| Default value  | X_MBF_PV_STR_DEF                                                                                                                  |
+| Description    | Specifies the maximum string length input to the V.42 <i>bis</i> encoder. This is an upper bound on V.42 <i>bis</i> parameter P2. |
+
+**Table I.7-24/T.180**
+
+|                |                                                                                                            |
+|----------------|------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_MBF_P_NON_STD_CAP                                                                                        |
+| Type of value  | unsigned long                                                                                              |
+| Legal values   | X_MBF_PV_NSC_UNSP Unspecified.                                                                             |
+| Default value  | X_MBF_PV_NSC_UNSP                                                                                          |
+| Description    | This parameter is used to negotiate non-standard functions, including non-standard compression techniques. |
+
+**Table I.7-25/T.180**
+
+|                |                                      |
+|----------------|--------------------------------------|
+| Parameter name | X_MBF_P_NODE_ID                      |
+| Type of value  | unsigned long                        |
+| Legal values   | a number in the range 1001 to 65 535 |
+| Default value  | none                                 |
+| Description    | Indicates the own Node ID.           |
+
+**Table I.7-26/T.180**
+
+|                |                                                                                                                                                                                   |
+|----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_MBF_P_ENTITY_ID                                                                                                                                                                 |
+| Type of value  | unsigned long                                                                                                                                                                     |
+| Legal values   | a 16-bit numeric identifier                                                                                                                                                       |
+| Default value  | none                                                                                                                                                                              |
+| Description    | Indicates the Entity ID of the corresponding MBFT Protocol module. The combination of the Entity ID and the Node ID uniquely identifies the MBFT Protocol module in a conference. |
+
+**Table I.7-27/T.180**
+
+|                |                                                                                                                                                                                           |                                                                                                                                                                                                                                                                            |
+|----------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_MBF_P_RESULT                                                                                                                                                                            |                                                                                                                                                                                                                                                                            |
+| Type of value  | unsigned long                                                                                                                                                                             |                                                                                                                                                                                                                                                                            |
+| Legal values   | X_MBF_PV_R_ACCEPT<br>X_MBF_PV_R_INV_CONF<br>X_MBF_PV_R_T_CONG<br>X_MBF_PV_R_TM_RES<br>X_MBF_PV_R_TM_USER<br>X_MBF_PV_R_NS_SESS_TYPE<br>X_MBF_PV_R_WRONG_SESS_TYPE<br>X_MBF_PV_R_NO_REASON | Connection accepted;<br>Rejection; invalid conference;<br>Rejection; temporary congestion;<br>Rejection; too many resources;<br>Rejection; too many users;<br>Rejection; session type not supported;<br>Rejection; wrong session type;<br>Rejection, reason not specified. |
+| Default value  | X_MBF_PV_R_ACCEPT                                                                                                                                                                         |                                                                                                                                                                                                                                                                            |
+| Description    | Indicates the success or failure of the connection establishment request.                                                                                                                 |                                                                                                                                                                                                                                                                            |
+
+### **I.7.7.3 Services in the connected state**
+
+The purpose of the services provided in the connected state is to distribute files among the session members. Additional services comprise getting information about the session (e.g. getting the actual list of the session members) and changing (some of) the session parameters negotiated in the connection establishment phase.
+
+#### **I.7.7.3.1 Services which apply to file distribution**
+
+Once the session has been established, all MBFT specific transactions are performed by the T.127 MBFT protocol module on behalf of the user application.
+
+### I.7.7.3.1.1 File Offer service
+
+#### I.7.7.3.1.1.1 Service description
+
+The File Offer service is used to offer a file to all intended recipients. These recipients are either all participants of the conference or a subset of them. Establishing a private sub-session within the existing session or using an already existing sub-session is part of the File Offer service and may be used to restrict the number of recipients.
+
+The service elements and their corresponding XAPI functions needed are described in Table I.7-28.
+
+**Table I.7-28/T.180 – Service elements and their corresponding XAPI functions for File Offer**
+
+| Service element         | Service element identifier | XAPI function | Description                                                                                          |
+|-------------------------|----------------------------|---------------|------------------------------------------------------------------------------------------------------|
+| File Offer Request      | X_MBF_SP_FO_Q              | x_sndsp()     | The File Offer Request is passed to the provider to send a request to all intended recipients.       |
+| File Offer Indication   | X_MBF_SP_FO_I              | x_revsp()     | The File Offer Indication is generated by the provider to indicate the offering of a file.           |
+| File Offer Response     | X_MBF_SP_FO_P              | x_sndsp()     | The File Offer Response is passed to the provider to indicate acceptance or rejection.               |
+| File Offer Confirmation | X_MBF_SP_FO_C              | x_rcvsp()     | The File Offer Confirmation is generated by the provider as acknowledgement of the previous request. |
+
+Two modes of offering a file are supported by the File Offer service. The recipients may either accept (reject) the offer or they are not asked to acknowledge the offer. In the latter case, only the request and the indication primitives apply.
+
+#### I.7.7.3.1.1.2 Service parameters
+
+Table I.7-29 specifies the parameters of the File Offer service.
+
+**Table I.7-29/T.180 – Parameters of the File Offer service**
+
+| Parameter            | File Offer service |            |          |              |
+|----------------------|--------------------|------------|----------|--------------|
+|                      | Request            | Indication | Response | Confirmation |
+| X_MBF_P_NODE_ID      |                    | M          |          |              |
+| X_MBF_P_ENTITY_ID    |                    | M          |          |              |
+| X_MBF_P_FHEADER_T434 | M                  | M (=)      |          |              |
+| X_MBF_P_SELECTIVE    | M                  |            |          |              |
+| X_MBF_P_FTS_MEMB     | C                  |            |          |              |
+| X_MBF_P_FILE_REF     | M                  | M (=)      | C (=)    | C (=)        |
+| X_MBF_P_COMPR        | U                  | C (=)      |          |              |
+
+**Table I.7-29/T.180 – Parameters of the File Offer service (concluded)**
+
+| Parameter            | File Offer service |            |          |              |
+|----------------------|--------------------|------------|----------|--------------|
+|                      | Request            | Indication | Response | Confirmation |
+| X_MBF_P_NB_OF_CWOR   | U                  | C (=)      |          |              |
+| X_MBF_P_MAX_STR_LNGH | U                  | C (=)      |          |              |
+| X_MBF_P_ACK_Q        | M                  | M (=)      |          |              |
+| X_MBF_P_REJ_FTS_MEMB |                    |            |          | C            |
+| X_MBF_P_ACK_P        |                    |            | C        |              |
+| X_MBF_P_FO_REASON    |                    |            | C        |              |
+
+**I.7.7.3.1.1.3 Service parameter descriptions**
+
+Tables I.7-30 to I.7-39 list the parameters of the File Offer service. The parameters X\_MBF\_P\_COMPR, X\_MBF\_P\_NB\_OF\_CWOR, and X\_MBF\_P\_MAX\_STR\_LNGH are described in the connection establishment phase. Therefore, their description is omitted in this subclause.
+
+**Table I.7-30/T.180**
+
+|                |                                                              |
+|----------------|--------------------------------------------------------------|
+| Parameter name | X_MBF_P_NODE_ID                                              |
+| Type of value  | unsigned long                                                |
+| Legal values   | a number in the range 1001 to 65 535                         |
+| Default value  | none                                                         |
+| Description    | Indicates the Node ID of the file offering user application. |
+
+**Table I.7-31/T.180**
+
+|                |                                                                                                                                                                                                                                            |
+|----------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_MBF_P_ENTITY_ID                                                                                                                                                                                                                          |
+| Type of value  | unsigned long                                                                                                                                                                                                                              |
+| Legal values   | a 16-bit numeric identifier                                                                                                                                                                                                                |
+| Default value  | none                                                                                                                                                                                                                                       |
+| Description    | Indicates the MBFT Protocol Entity ID of the file offering user application. The combination of the Entity ID and the Node ID uniquely identifies the MBFT Protocol Entity in a conference and so the corresponding MBFT user application. |
+
+**Table I.7-32/T.180**
+
+|                |                                                                                                                                                         |
+|----------------|---------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_MBF_P_FHEADER_T434                                                                                                                                    |
+| Type of value  | struct                                                                                                                                                  |
+| Legal values   | a list of optional BFT file attributes defined in Recommendation T.434                                                                                  |
+| Default value  | T.434 protocol version number                                                                                                                           |
+| Description    | Uses the T.434 file header structure and should include sufficient information to allow intending recipients to determine whether the file is required. |
+
+**Table I.7-33/T.180**
+
+|                |                                                                                                  |
+|----------------|--------------------------------------------------------------------------------------------------|
+| Parameter name | X_MBF_P_SELECTIVE                                                                                |
+| Type of value  | unsigned long                                                                                    |
+| Legal values   | PV_TRUE      Distribution to a subgroup;<br>PV_FALSE     Broadcasting.                           |
+| Default value  | PV_FALSE                                                                                         |
+| Description    | Indicates the distribution of the file to all or to a subgroup of file transfer session members. |
+
+**Table I.7-34/T.180**
+
+|                |                                                                              |
+|----------------|------------------------------------------------------------------------------|
+| Parameter name | X_MBF_P_FTS_MEMB                                                             |
+| Type of value  | sequence<sequence<unsigned long, 2> >                                        |
+| Legal values   | a list of tuples, each consisting of two numbers: NodeID and EntityID        |
+| Default value  | none                                                                         |
+| Description    | Contains a list of user applications for establishing a private sub-session. |
+
+**Table I.7-35/T.180**
+
+|                |                                                                                                                                                                                                                                 |
+|----------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_MBF_P_FILE_REF                                                                                                                                                                                                                |
+| Type of value  | string                                                                                                                                                                                                                          |
+| Legal values   | a numerical number                                                                                                                                                                                                              |
+| Default value  | none                                                                                                                                                                                                                            |
+| Description    | Indicates the file reference number (i.e. dataflow identification). This number should start by 1 and should be incremented for every file transfer which is transmitted in the same connection. Leading zeros will be ignored. |
+
+**Table I.7-36/T.180**
+
+|                |                                                                                                     |
+|----------------|-----------------------------------------------------------------------------------------------------|
+| Parameter name | X_MBF_P_ACK_Q                                                                                       |
+| Type of value  | unsigned long                                                                                       |
+| Legal values   | PV_TRUE<br>PV_FALSE                                                                                 |
+| Default value  | PV_FALSE                                                                                            |
+| Description    | Indicates that receiving user applications must signal whether or not they wish to accept the file. |
+
+**Table I.7-37/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
+|----------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_MBF_P_REJ_FTS_MEMB                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
+| Type of value  | sequence<sequence<unsigned long, 3> >                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
+| Legal values   | A list of tripels, each consisting of three numbers: NodeID, EntityID, and Reason for Rejection.                                                                                                                                                                                                                                                                                                                                                                                                                        |
+| Default value  | none                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
+| Description    | Indicates the members which are unable or do not wish to receive the offered file. The possible reasons for rejection are:<br>X_MBF_PV_FOR_NORESP                No response;<br>X_MBF_PV_FOR_UNSPEC                Unspecified;<br>X_MBF_PV_FOR_FEXIST                File exists;<br>X_MBF_PV_FOR_FNOTREQUIRE        File not required;<br>X_MBF_PV_FOR_INSUFFRES            Insufficient resources;<br>X_MBF_PV_FOR_UNSUPPCOMPR        Compression unsupported;<br>algorithm identified in File Offer not supported. |
+
+**Table I.7-38/T.180**
+
+|                |                                                      |
+|----------------|------------------------------------------------------|
+| Parameter name | X_MBF_P_ACK_P                                        |
+| Type of value  | unsigned long                                        |
+| Legal values   | PV_TRUE<br>PV_FALSE                                  |
+| Default value  | PV_FALSE                                             |
+| Description    | Indicates the intention to receive the offered file. |
+
+**Table I.7-39/T.180**
+
+|                |                                                                                                                              |                                                                                                                                                                   |
+|----------------|------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_MBF_P_FO_REASON                                                                                                            |                                                                                                                                                                   |
+| Type of value  | unsigned long                                                                                                                |                                                                                                                                                                   |
+| Legal values   | X_MBF_PV_FOR_UNSPEC<br>X_MBF_PV_FOR_FEXIST<br>X_MBF_PV_FOR_FNOTREQUIRE<br>X_MBF_PV_FOR_INSUFFRES<br>X_MBF_PV_FOR_UNSUPPCOMPR | Unspecified;<br>File exists;<br>File not required;<br>Insufficient resources;<br>Compression unsupported;<br>algorithm identified in File Offer<br>not supported. |
+| Default value  | none                                                                                                                         |                                                                                                                                                                   |
+| Description    | Informs the transmitter why the intended recipient is unable or does not wish to receive the file offered.                   |                                                                                                                                                                   |
+
+**I.7.7.3.1.2 Start of File service****I.7.7.3.1.2.1 Service description**
+
+The Start of File service indicates the start of the document to the receiver. It also indicates the start of the first data part.
+
+The service elements and their corresponding XAPI functions needed are described in Table I.7-40.
+
+**Table I.7-40/T.180 – Service elements and their corresponding XAPI functions for Start of File**
+
+| Service element          | Service element identifier | XAPI function | Description                                                                                       |
+|--------------------------|----------------------------|---------------|---------------------------------------------------------------------------------------------------|
+| Start of File Request    | X_MBF_SP_SOF_Q             | x_sndsp()     | The Start of File Request is passed to the provider to send a request to all intended recipients. |
+| Start of File Indication | X_MBF_SP_SOF_I             | x_rcvsp()     | The Start of File Indication is generated by the provider to indicate the start of a file.        |
+
+**I.7.7.3.1.2.2 Service parameters**
+
+Table I.7-41 specifies the parameters of the Start of File service.
+
+**Table I.7-41/T.180 – Parameters of the Start of File service**
+
+| Parameter            | Start of File service |            |
+|----------------------|-----------------------|------------|
+|                      | Request               | Indication |
+| X_MBF_P_NODE_ID      |                       | M          |
+| X_MBF_P_ENTITY_ID    |                       | M          |
+| X_MBF_P_FHEADER_T434 | M                     | M (=)      |
+| X_MBF_P_FILE_REF     | M (=)                 | M (=)      |
+| X_MBF_P_EOF          | M                     | M (=)      |
+
+**Table I.7-41/T.180 – Parameters of the Start of File service (concluded)**
+
+| Parameter            | Start of File service |            |
+|----------------------|-----------------------|------------|
+|                      | Request               | Indication |
+| X_MBF_P_CRC          | M                     | M (=)      |
+| X_MBF_P_COMPR        | U                     | C (=)      |
+| X_MBF_P_NB_OF_CWOR   | U                     | C (=)      |
+| X_MBF_P_MAX_STR_LNGH | U                     | C (=)      |
+| X_MBF_P_DATA_OFFSET  | M                     | M (=)      |
+
+**I.7.7.3.1.2.3 Service parameter descriptions**
+
+Tables I.7-42 to I.7-48 list the parameters of the Start of File service. The parameters X\_MBF\_P\_COMPR, X\_MBF\_P\_NB\_OF\_CWOR, and X\_MBF\_P\_MAX\_STR\_LNGH are described in the connection establishment phase. Therefore, their description is omitted in this subclause.
+
+**Table I.7-42/T.180**
+
+|                |                                                              |
+|----------------|--------------------------------------------------------------|
+| Parameter name | X_MBF_P_NODE_ID                                              |
+| Type of value  | unsigned long                                                |
+| Legal values   | a number in the range 1001 to 65 535                         |
+| Default value  | none                                                         |
+| Description    | Indicates the Node ID of the file offering user application. |
+
+**Table I.7-43/T.180**
+
+|                |                                                                                                                                                                                             |
+|----------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_MBF_P_ENTITY_ID                                                                                                                                                                           |
+| Type of value  | unsigned long                                                                                                                                                                               |
+| Legal values   | a 16-bit numeric identifier                                                                                                                                                                 |
+| Default value  | none                                                                                                                                                                                        |
+| Description    | Indicates the MBFT Protocol Entity ID of the file offering user application. The combination of the Entity ID and the Node ID uniquely identifies the MBFT Protocol module in a conference. |
+
+**Table I.7-44/T.180**
+
+|                |                                                                                                |
+|----------------|------------------------------------------------------------------------------------------------|
+| Parameter name | X_MBF_P_FHEADER_T434                                                                           |
+| Type of value  | struct                                                                                         |
+| Legal values   | a list of optional BFT file attributes defined in Recommendation T.434                         |
+| Default value  | T.434 protocol version number                                                                  |
+| Description    | Uses the T.434 file header structure and should include all fields defined in the source file. |
+
+**Table I.7-45/T.180**
+
+|                |                                                                                |
+|----------------|--------------------------------------------------------------------------------|
+| Parameter name | X_MBF_P_FILE_REF                                                               |
+| Type of value  | string                                                                         |
+| Legal values   | a numerical number                                                             |
+| Default value  | none                                                                           |
+| Description    | Indicates the file reference number which was given in the File Offer Request. |
+
+**Table I.7-46/T.180**
+
+|                |                                |
+|----------------|--------------------------------|
+| Parameter name | X_MBF_P_EOF                    |
+| Type of value  | unsigned long                  |
+| Legal values   | PV_TRUE<br>PV_FALSE            |
+| Default value  | PV_FALSE                       |
+| Description    | Indicates the end of the file. |
+
+**Table I.7-47/T.180**
+
+|                |                                                                                                                                                   |
+|----------------|---------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_MBF_P_CRC                                                                                                                                       |
+| Type of value  | unsigned long                                                                                                                                     |
+| Legal values   | X_MBF_PV_CRC_NO          No CRC;<br>X_MBF_PV_CRC_SINGLE      Single CRC sent at end of File Transfer;<br>X_MBF_PV_CRC_CUMU        Cumulative CRC. |
+| Default value  | X_MBF_PV_CRC_NO                                                                                                                                   |
+| Description    | Indicates the use of a cyclic redundancy check.                                                                                                   |
+
+**Table I.7-48/T.180**
+
+|                |                                                                                                           |
+|----------------|-----------------------------------------------------------------------------------------------------------|
+| Parameter name | X_MBF_P_DATA_OFFSET                                                                                       |
+| Type of value  | unsigned long                                                                                             |
+| Legal values   |                                                                                                           |
+| Default value  | none                                                                                                      |
+| Description    | Specifies the starting offset in octets from the beginning of the file data (so zero denotes the origin). |
+
+### **I.7.7.3.1.3 Data Transfer service**
+
+#### **I.7.7.3.1.3.1 Service Description**
+
+The Data Transfer service is used to transfer files between session members.
+
+The service elements and their corresponding XAPI functions needed are described in Table I.7-49.
+
+**Table I.7-49/T.180 – Service elements and their corresponding XAPI functions for Data Transfer**
+
+| Service element          | XAPI function | Description                                                                              |
+|--------------------------|---------------|------------------------------------------------------------------------------------------|
+| Data Transfer Request    | x_snddata()   | The Data Transfer Request is passed to the provider to transmit data.                    |
+| Data Transfer Indication | x_rcvdata()   | The Data Transfer Indication is generated by the provider to indicate the received data. |
+
+#### I.7.7.3.1.3.2 Service parameters
+
+Table I.7-50 specifies the parameters of the Data Transfer service.
+
+**Table I.7-50/T.180 – Parameters of the Data Transfer service**
+
+| Parameter         | Data Transfer service |            |
+|-------------------|-----------------------|------------|
+|                   | Request               | Indication |
+| X_MBF_P_FILE_REF  | M (=)                 | M (=)      |
+| X_MBF_P_EOF       | M                     | M (=)      |
+| X_MBF_P_ABORT     | M                     | M (=)      |
+| X_MBF_P_CRC_CHECK | C                     | C          |
+
+#### I.7.7.3.1.3.3 Service parameter descriptions
+
+Tables I.7-51 to I.7-54 list the parameters of the Data Transfer service.
+
+**Table I.7-51/T.180**
+
+|                |                                                                                |
+|----------------|--------------------------------------------------------------------------------|
+| Parameter name | X_MBF_P_FILE_REF                                                               |
+| Type of value  | string                                                                         |
+| Legal values   | a numerical number                                                             |
+| Default value  | none                                                                           |
+| Description    | Indicates the file reference number which was given in the File Offer Request. |
+
+**Table I.7-52/T.180**
+
+|                |                                |
+|----------------|--------------------------------|
+| Parameter name | X_MBF_P_EOF                    |
+| Type of value  | unsigned long                  |
+| Legal values   | PV_TRUE<br>PV_FALSE            |
+| Default value  | PV_FALSE                       |
+| Description    | Indicates the end of the file. |
+
+**Table I.7-53/T.180**
+
+|                |                                                                      |
+|----------------|----------------------------------------------------------------------|
+| Parameter name | X_MBF_P_ABORT                                                        |
+| Type of value  | unsigned long                                                        |
+| Legal values   | PV_TRUE<br>PV_FALSE                                                  |
+| Default value  | PV_FALSE                                                             |
+| Description    | This parameter is set to TRUE if the file transfer is being aborted. |
+
+**Table I.7-54/T.180**
+
+|                |                              |
+|----------------|------------------------------|
+| Parameter name | X_MBF_P_CRC_CHECK            |
+| Type of value  | unsigned long                |
+| Legal values   | a 32-bit number              |
+| Default value  | none                         |
+| Description    | The cyclic redundancy check. |
+
+#### **I.7.7.3.1.4 Please Privilege service**
+
+##### **I.7.7.3.1.4.1 Service description**
+
+The Please Privilege service is used in the conducted mode by user applications at non-conducting nodes to request permission to act from the conductor. The following privileges are available:
+
+- source file transfers;
+- request file transfers;
+- selective file transfers;
+- source file transfers with higher priority;
+- issue a file transfer abort;
+- use non-standard extensions.
+
+The service elements and their corresponding XAPI functions needed are described in Table I.7-55.
+
+**Table I.7-55/T.180 – Service elements and their corresponding XAPI functions for Please Privilege**
+
+| <b>Service element</b>      | <b>Service element identifier</b> | <b>XAPI function</b> | <b>Description</b>                                                                               |
+|-----------------------------|-----------------------------------|----------------------|--------------------------------------------------------------------------------------------------|
+| Please Privilege Request    | X_MBF_SP_PP_Q                     | x_sndsp()            | The Please Privilege Request is passed to the provider to request privileges from the conductor. |
+| Please Privilege Indication | X_MBF_SP_PP_I                     | x_rcvsp()            | The Please Privilege Indication is generated by the provider to indicate a privilege request.    |
+
+##### **I.7.7.3.1.4.2 Service parameters**
+
+Table I.7-56 specifies the parameters of the Please Privilege service.
+
+**Table I.7-56/T.180 – Parameters of the  
+Please Privilege service**
+
+| Parameter         | Please Privilege service |            |
+|-------------------|--------------------------|------------|
+|                   | Request                  | Indication |
+| X_MBF_P_PRI_FT    | U                        | C (=)      |
+| X_MBF_P_PRI_FQ    | U                        | C (=)      |
+| X_MBF_P_PRI_SEL   | U                        | C (=)      |
+| X_MBF_P_PRI_ORITY | U                        | C (=)      |
+| X_MBF_P_PRI_ABORT | U                        | C (=)      |
+| X_MBF_P_PRI_NSTD  | U                        | C (=)      |
+
+### I.7.7.3.1.4.3 Service parameter descriptions
+
+Tables I.7-57 to I.7-62 list the parameters of the Please Privilege service.
+
+**Table I.7-57/T.180**
+
+|                |                                                                                              |
+|----------------|----------------------------------------------------------------------------------------------|
+| Parameter name | X_MBF_P_PRI_FT                                                                               |
+| Type of value  | unsigned long                                                                                |
+| Legal values   | PV_TRUE<br>PV_FALSE                                                                          |
+| Default value  | PV_FALSE                                                                                     |
+| Description    | Indicates whether the requesting user application wants permission to source file transfers. |
+
+**Table I.7-58/T.180**
+
+|                |                                                                                                         |
+|----------------|---------------------------------------------------------------------------------------------------------|
+| Parameter name | X_MBF_P_PRI_FQ                                                                                          |
+| Type of value  | unsigned long                                                                                           |
+| Legal values   | PV_TRUE<br>PV_FALSE                                                                                     |
+| Default value  | PV_FALSE                                                                                                |
+| Description    | Indicates whether the requesting user application wants permission to request files or retransmissions. |
+
+**Table I.7-59/T.180**
+
+|                |                                                                                                |
+|----------------|------------------------------------------------------------------------------------------------|
+| Parameter name | X_MBF_P_PRI_SEL                                                                                |
+| Type of value  | unsigned long                                                                                  |
+| Legal values   | PV_TRUE<br>PV_FALSE                                                                            |
+| Default value  | PV_FALSE                                                                                       |
+| Description    | Indicates whether the requesting user application wants permission to selective file transfer. |
+
+**Table I.7-60/T.180**
+
+|                |                                                                                                    |
+|----------------|----------------------------------------------------------------------------------------------------|
+| Parameter name | X_MBF_P_PRI_ORITY                                                                                  |
+| Type of value  | unsigned long                                                                                      |
+| Legal values   | PV_TRUE<br>PV_FALSE                                                                                |
+| Default value  | PV_FALSE                                                                                           |
+| Description    | Indicates whether the requesting user application wants permission to send with a higher priority. |
+
+**Table I.7-61/T.180**
+
+|                |                                                                                                    |
+|----------------|----------------------------------------------------------------------------------------------------|
+| Parameter name | X_MBF_P_PRI_ABORT                                                                                  |
+| Type of value  | unsigned long                                                                                      |
+| Legal values   | PV_TRUE<br>PV_FALSE                                                                                |
+| Default value  | PV_FALSE                                                                                           |
+| Description    | Indicates whether the requesting user application wants permission to issue a file transfer abort. |
+
+**Table I.7-62/T.180**
+
+|                |                                                                                                                                        |
+|----------------|----------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_MBF_P_PRI_NSTD                                                                                                                       |
+| Type of value  | unsigned long                                                                                                                          |
+| Legal values   | PV_TRUE<br>PV_FALSE                                                                                                                    |
+| Default value  | PV_FALSE                                                                                                                               |
+| Description    | Indicates whether the requesting user application wants permission to use any negotiated non-standard extensions to the MBFT protocol. |
+
+### **I.7.7.3.1.5 Assign Privilege service**
+
+#### **I.7.7.3.1.5.1 Service description**
+
+The Assign Privilege service is used in the conducted mode by the conductor to grant or revoke privileges for user applications at non-conducting nodes. The following privileges are available:
+
+- source file transfers;
+- request file transfers;
+- selective file transfers;
+- source file transfers with higher priority;
+- issue a file transfer abort;
+- use non-standard extensions.
+
+The service elements and their corresponding XAPI functions needed are described in Table I.7-63.
+
+**Table I.7-63/T.180 – Service elements and their corresponding XAPI functions for Assign Privilege**
+
+| Service element             | Service element identifier | XAPI function | Description                                                                                                               |
+|-----------------------------|----------------------------|---------------|---------------------------------------------------------------------------------------------------------------------------|
+| Assign Privilege Request    | X_MBF_SP_AP_Q              | x_sndsp()     | The Assign Privilege Request is passed to the provider to assign privileges to user applications at non-conducting nodes. |
+| Assign Privilege Indication | X_MBF_SP_AP_I              | x_rcvsp()     | The Assign Privilege Indication is generated by the provider to indicate assigned privileges from the conductor.          |
+
+#### **I.7.7.3.1.5.2 Service parameters**
+
+Table I.7-64 specifies the parameters of the Assign Privilege service.
+
+**Table I.7-64/T.180 – Parameter of the Assign Privilege service**
+
+| Parameter       | Assign Privilege service |            |
+|-----------------|--------------------------|------------|
+|                 | Request                  | Indication |
+| X_MBF_P_PRI_LST | M                        | M (=)      |
+
+#### **I.7.7.3.1.5.3 Service parameter descriptions**
+
+Table I.7-65 describes the parameter of the Assign Privilege service.
+
+**Table I.7-65/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
+|----------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_MBF_P_PRI_LST                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
+| Type of value  | sequence<sequence<unsigned long, 8> >                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
+| Legal values   | A list of 8-tuples, each consisting of eight numbers: NodeID, EntityID, and the six privileges parameters.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
+| Default value  | none                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
+| Description    | <p>Contains a list of one or more user applications and the privileges assigned to them:</p> <p>The File Transfer parameter indicates whether the user application has been granted permission to source file transfers.</p> <p>The File Request parameter indicates whether the user application has been granted permission to request files or retransmissions.</p> <p>The Selective File Transfer parameter indicates whether the user application has been granted permission to selective file transfer.</p> <p>The Priority parameter indicates whether the user application has been granted permission to send with a higher priority.</p> <p>The Abort parameter indicates whether the user application has been granted permission to issue a file transfer abort.</p> <p>The Non-Standard parameter indicates whether the user application has been granted permission to issue any negotiated non-standard extensions to the MBFT protocol.</p> |
+
+### **I.7.7.3.2 Information services**
+
+The services described in this subclause allow session members to get information about the current session. The member may either request information or he will get information from the provider in cases where specific parameters characterizing the current session have changed their values.
+
+#### **I.7.7.3.2.1 Application Roster service**
+
+##### **I.7.7.3.2.1.1 Service description**
+
+The Application Roster service is used to support members with session-specific information.
+
+The service elements and their corresponding XAPI functions needed are described in Table I.7-66.
+
+**Table I.7-66/T.180 – Service element and their corresponding XAPI function for Application Roster**
+
+| Service element               | Service element identifier | XAPI function | Description                                                                                                                   |
+|-------------------------------|----------------------------|---------------|-------------------------------------------------------------------------------------------------------------------------------|
+| Application Roster Indication | X_MBF_SP_AR_I              | x_rcvinfo()   | The Application Roster Indication is generated by the provider to support a session member with session-specific information. |
+
+##### **I.7.7.3.2.1.2 Service parameters**
+
+Table I.7-67 specifies the parameters of the Application Roster service.
+
+**Table I.7-67/T.180 – Parameter of the Application Roster service**
+
+| Parameter       | Application Roster service |
+|-----------------|----------------------------|
+|                 | Indication                 |
+| X_MBF_P_AROSTER | M                          |
+
+**I.7.7.3.2.1.3 Service parameter descriptions**
+
+Table I.7-68/T.180 defines the parameter for the Application Roster service.
+
+**Table I.7-68/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |  |
+|----------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--|
+| Parameter name | X_MBF_P_AROSTER                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |  |
+| Type of value  | <pre> typedef struct ApplicationRecord {     unsigned long    NodeID;     unsigned long    EntityID;     unsigned long    Active;     unsigned long    Cond_Cap;     string           UserApplicationID;     sequence&lt;string&gt; NCollapsCapsList; };  typedef struct ApplicationCapability {     unsigned long    CapabilityID;     unsigned long    CapabilityValue; };  typedef struct Session{     string                               ApplicationProtocolKey;     unsigned long                        SessionID;     sequence&lt;ApplicationRecord&gt;         ApplicationRecordList;     sequence&lt;ApplicationCapability&gt;     ApplicationCapabilityList; };  sequence&lt;Session&gt;; </pre> |  |
+| Legal values   | <p>NodeID: A number in the range 1001 to 65 535;</p> <p>EntityID: A 16-bit numeric identifier;</p> <p>Active: PV_TRUE/PV_FALSE Ready to receive data;</p> <p>Cond_Cap: PV_TRUE/PV_FALSE Conducting capable;</p> <p>UserApplicationID: A text string Identifies the MBFT user application;</p> <p>NCollapsCapsList: A list of text strings Non-Collapsing capabilities;</p> <p>CapabilityID: A number Identifies an Application Capability;</p> <p>CapabilityValue: A number Dependent from the Capability Class;</p> <p>ApplicationProtocolKey: A text string Identifies the MBFT Protocol;</p> <p>SessionID: A number in the range 1 to 65 535.</p>                                                         |  |
+| Default value  | none                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |  |
+| Description    | The Application Roster includes a list of roster entries for a specific or each MBFT Protocol Session.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |  |
+
+### I.7.7.3.2.2 Conference Roster service
+
+#### I.7.7.3.2.2.1 Service description
+
+The service elements and their corresponding XAPI functions needed are described in Table I.7-69.
+
+**Table I.7-69/T.180 – Service element and their corresponding XAPI function for Conference Roster**
+
+| Service element              | Service element identifier | XAPI function | Description                                                   |
+|------------------------------|----------------------------|---------------|---------------------------------------------------------------|
+| Conference Roster Indication | X_MBF_SP_CR_I              | x_rcvinfo()   | The Service indicates whenever the Conference Roster changes. |
+
+#### I.7.7.3.2.2.2 Service parameters
+
+Table I.7-70 specifies the parameter of the Conference Roster service.
+
+**Table I.7-70/T.180 – Parameter of the Conference Roster service**
+
+| Parameter       | Conference Roster service |
+|-----------------|---------------------------|
+|                 | Indication                |
+| X_MBF_P_CROSTER | M                         |
+
+#### I.7.7.3.2.2.3 Service parameter descriptions
+
+Table I.7-71 defines the parameter for the Conference Roster service.
+
+**Table I.7-71/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                    |
+|----------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_MBF_P_CROSTER                                                                                                                                                                                                                                                                                                                    |
+| Type of value  | <pre>typedef struct Conference {     unsigned long      NodeID;     unsigned long      Node_Type;     string              Node_Name;     sequence&lt;string&lt;255&gt; &gt; Part_List;     string              Site_Info     string              Net_Addr;     string              User_Data; }; sequence&lt;Conference&gt;;</pre> |
+
+**Table I.7-71/T.180 (concluded)**
+
+|               |                                                                                                                                                                                                                                                                                                                                                                                           |
+|---------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Legal values  | NodeID: A number in the range 1001 to 65 535;<br>Node_Type: X_CON_PV_TERMINAL,<br>X_CON_PV_MULTIPORT_TERMINAL,<br>or X_CON_PV_MCU;<br>Node_Name: A text string;<br>Part_List: A list of text strings Participants' Names;<br>Site_Info A text string Additional Information about the node;<br>Net_Addr: A text string Network address;<br>User_Data: A text string Additional user data. |
+| Default value | none                                                                                                                                                                                                                                                                                                                                                                                      |
+| Description   | This parameter contains a description of each node joined to the conference. The parameters Node Name, Participants Names, Site Information, Network Address, and User Data in the List of Conference Nodes are conditional.                                                                                                                                                              |
+
+### I.7.7.3.2.3 Conference Conductor Inquire service
+
+This service may be issued to find out whether the conference is conducted or not, and if so, which node is the conductor, and if the requesting node has been granted conducted-mode permission.
+
+#### I.7.7.3.2.3.1 Service description
+
+The service elements and their corresponding XAPI functions needed are described in Table I.7-72.
+
+**Table I.7-72/T.180 – Service elements and their corresponding XAPI functions for Conference Conductor Inquire**
+
+| Service element                           | Service element identifier | XAPI function | Description                                                                                                         |
+|-------------------------------------------|----------------------------|---------------|---------------------------------------------------------------------------------------------------------------------|
+| Conference Conductor Inquire Request      | X_MBF_SP_CCI_Q             | x_sndinfo()   | The Conference Conductor Inquire Request is passed to the provider to request information about the conductor.      |
+| Conference Conductor Inquire Confirmation | X_MBF_SP_CCI_C             | x_rcvinfo()   | The Conference Conductor Inquire Confirmation is a positive or negative response to a previous information request. |
+
+#### I.7.7.3.2.3.2 Service parameters
+
+Table I.7-73 specifies the parameters of the Conference Conductor Inquire service.
+
+**Table I.7-73/T.180 – Parameters of the Conference Conductor Inquire service**
+
+| Parameter          | Conference Conductor Inquire service |              |
+|--------------------|--------------------------------------|--------------|
+|                    | Request                              | Confirmation |
+| X_MBF_P_CONDUCTED  |                                      | M            |
+| X_MBF_P_COND_NODE  |                                      | C            |
+| X_MBF_P_PERMISSION |                                      | C            |
+
+**I.7.7.3.2.3.3 Service parameter descriptions**
+
+Tables I.7-74 to I.7-76 define the parameters for the Conference Conductor Inquire service.
+
+**Table I.7-74/T.180**
+
+|                |                               |
+|----------------|-------------------------------|
+| Parameter name | X_MBF_P_CONDUCTED             |
+| Type of value  | unsigned long                 |
+| Legal values   | PV_TRUE<br>PV_FALSE           |
+| Default value  | none                          |
+| Description    | Indicates the conducted mode. |
+
+**Table I.7-75/T.180**
+
+|                |                                                                                                                             |
+|----------------|-----------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_MBF_P_COND_NODE                                                                                                           |
+| Type of value  | unsigned long                                                                                                               |
+| Legal values   | a number between 1001 and 65 535                                                                                            |
+| Default value  | none                                                                                                                        |
+| Description    | Indicates the node ID of the current conference conductor. It is only available if the conference is in the conducted mode. |
+
+**Table I.7-76/T.180**
+
+|                |                                                                                                                                                      |
+|----------------|------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_MBF_P_PERMISSION                                                                                                                                   |
+| Type of value  | unsigned long                                                                                                                                        |
+| Legal values   | PV_TRUE<br>PV_FALSE                                                                                                                                  |
+| Default value  | none                                                                                                                                                 |
+| Description    | Indicates whether or not the local node has been granted conducted mode permission. It is only available if the conference is in the conducted mode. |
+
+**I.7.7.3.2.4 Conductor Report service****I.7.7.3.2.4.1 Service description**
+
+The service element and their corresponding XAPI function needed is described in Table I.7-77.
+
+**Table I.7-77/T.180 – Service elements and their corresponding XAPI functions for Conductor Report**
+
+| Service element             | Service element identifier | XAPI function | Description                                                                 |
+|-----------------------------|----------------------------|---------------|-----------------------------------------------------------------------------|
+| Conductor Report Indication | X_MBF_CONDR_I              | x_rcvinfo()   | The Conductor Report Indication informs about changes in the conductorship. |
+
+#### I.7.7.3.2.4.2 Service parameters
+
+Table I.7-78 specifies the parameters of the Conductor Report service.
+
+**Table I.7-78/T.180 – Parameters of the Conductor Report service**
+
+| Parameter         | Conductor Report Service |
+|-------------------|--------------------------|
+|                   | Indication               |
+| X_MBF_P_COND_MODE | M                        |
+| X_MBF_P_REQ_NODE  | C                        |
+
+#### I.7.7.3.2.4.3 Service parameter descriptions
+
+Tables I.7-79 and I.7-80 define the parameters for the Conductor Report service.
+
+**Table I.7-79/T.180**
+
+|                |                                                                                                                              |
+|----------------|------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_CON_P_COND_MODE                                                                                                            |
+| Type of value  | unsigned long                                                                                                                |
+| Legal values   | PV_TRUE<br>PV_FALSE                                                                                                          |
+| Default value  | PV_FALSE                                                                                                                     |
+| Description    | This parameter indicates that the conference is now in the conducted mode (PV_TRUE) or in the non-conducted mode (PV_FALSE). |
+
+**Table I.7-80/T.180**
+
+|                |                                                                                                                                                                |
+|----------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_CON_P_REQ_NODE                                                                                                                                               |
+| Type of value  | unsigned long                                                                                                                                                  |
+| Legal values   | a number between 1001 and 65 535                                                                                                                               |
+| Default value  | none                                                                                                                                                           |
+| Description    | Indicates the conductor node identification. This parameter is only meaningful when the conference is now in the conducted mode (X_MBF_P_COND_MODE = PV_TRUE). |
+
+#### I.7.7.3.3 Services which change session parameters
+
+A T.127 MBFT protocol module may change its capabilities at any time by re-enrolling. To do this, the user application issues a service request with the revised parameter values. Any changes of
+
+parameter values will not affect transactions already in progress. Changes will take effect when the next transaction is initiated.
+
+### I.7.7.3.3.1 Change Resource service
+
+#### I.7.7.3.3.1.1 Service description
+
+The Change Resource service is used to request the provider to change the values of specific session-related parameters.
+
+The service elements and their corresponding XAPI functions needed are described in Table I.7-81.
+
+**Table I.7-81/T.180 – Service elements and their corresponding XAPI functions for Change Resource**
+
+| Service element              | Service element identifier | XAPI function | Description                                                                                                          |
+|------------------------------|----------------------------|---------------|----------------------------------------------------------------------------------------------------------------------|
+| Change Resource Request      | X_MBF_SP_CHR_Q             | x_sndsp()     | The Change Resource Request is passed to the provider to request the change of values of session-related parameters. |
+| Change Resource Confirmation | X_MBF_SP_CHR_C             | x_rcvsp()     | The Change Resource Confirmation is generated by the provider as acknowledgement of the previous request.            |
+
+#### I.7.7.3.3.1.2 Service parameters
+
+Table I.7-82 specifies the parameters of the Change Resource service.
+
+**Table I.7-82/T.180 – Parameters of the Change Resource service**
+
+| Parameter             | Change Resource service |              |
+|-----------------------|-------------------------|--------------|
+|                       | Request                 | Confirmation |
+| X_MBF_P_COND_OP_CAP   | U                       |              |
+| X_MBF_P_M_MODE        | U                       | M            |
+| X_MBF_P_LIST_OF_MEMB  | U                       |              |
+| X_MBF_P_EXPEL_MEMB    | U                       |              |
+| X_MBF_P_MAX_FILE_SIZE | U                       | C            |
+| X_MBF_P_MAX_DAT_PAYL  | U                       | C            |
+| X_MBF_P_COMPR         | U                       | C            |
+| X_MBF_P_NB_OF_CWOR    | U                       | C            |
+| X_MBF_P_MAX_STR_LNGH  | U                       | C            |
+| X_MBF_P_NON_STD_CAP   | C                       | C            |
+| X_MBF_P_CHR_RESULT    |                         | M            |
+
+### I.7.7.3.3.1.3 Service parameter descriptions
+
+Tables I.7-83 to I.7-93 list the parameters of the Change Resource service.
+
+**Table I.7-83/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
+|----------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_MBF_P_COND_OP_CAP                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
+| Type of value  | unsigned long                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
+| Legal values   | PV_TRUE<br>PV_FALSE                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
+| Default value  | PV_FALSE                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
+| Description    | The Conducting Operation Capable parameter indicates whether the MBFT Protocol module is capable of operating as a session conductor. Each MBFT Session has its own conductor, namely the MBFT Protocol module at the conducting node participating in that Session. If there is more than one MBFT Protocol module at the conducting node in a given MBFT Session, then it is a local matter for GCC at the conducting node to decide which MBFT Protocol module adopts the role of session conductor. |
+
+**Table I.7-84/T.180**
+
+|                |                                                                                                                                                                                                                        |
+|----------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_MBF_P_M_MODE                                                                                                                                                                                                         |
+| Type of value  | unsigned long                                                                                                                                                                                                          |
+| Legal values   | X_MBF_PV_MM_REC           Receive files only;<br>X_MBF_PV_MM_SND          Transmit files only;<br>X_MBF_PV_MM_SND_REC      Transmit and receive files;<br>X_MBF_PV_MM_N_SND_REC    Neither transmit nor receive files. |
+| Default value  | none                                                                                                                                                                                                                   |
+| Description    | Indicates the T.127 MBFT protocol module mode. It is dependent from the protocol option X_MBF_O_M_TYPE.                                                                                                                |
+
+**Table I.7-85/T.180**
+
+|                |                                                                                                  |
+|----------------|--------------------------------------------------------------------------------------------------|
+| Parameter name | X_MBF_P_LIST_OF_MEMB                                                                             |
+| Type of value  | sequence<unsigned long>                                                                          |
+| Legal values   | A list of numbers in the range 1001 to 65 535                                                    |
+| Default value  | none                                                                                             |
+| Description    | This parameter is used to invite participants (specified by their NodeIDs) to a private session. |
+
+**Table I.7-86/T.180**
+
+|                |                                                                                              |
+|----------------|----------------------------------------------------------------------------------------------|
+| Parameter name | X_MBF_P_EXPEL_MEMB                                                                           |
+| Type of value  | sequence<unsigned long>                                                                      |
+| Legal values   | A list of numbers in the range 1001 to 65 535                                                |
+| Default value  | none                                                                                         |
+| Description    | This parameter is used to expel members (specified by their NodeIDs) from a private session. |
+
+**Table I.7-87/T.180**
+
+|                |                                                                                                                                                        |
+|----------------|--------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_MBF_P_MAX_FILE_SIZE                                                                                                                                  |
+| Type of value  | unsigned long                                                                                                                                          |
+| Legal values   | X_MBF_PV_FS_UNLIM      Unlimited;<br>X_MBF_PV_FS_MAX_VAL    Maximum file data payload in octets.                                                       |
+| Default value  | X_MBF_PV_FS_UNLIM                                                                                                                                      |
+| Description    | Indicates the maximum file size. Each T.127 MBFT protocol module must specify the maximum file data payload in octets that it is capable of receiving. |
+
+**Table I.7-88/T.180**
+
+|                |                                                                                                                                       |
+|----------------|---------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_MBF_P_MAX_DAT_PAYL                                                                                                                  |
+| Type of value  | unsigned long                                                                                                                         |
+| Legal values   | X_MBF_PV_DP_DEF          Default value (8192 octets)<br>X_MBF_PV_DP_MAX_VAL    Maximum number (less or equal 65 536 octets)           |
+| Default value  | X_MBF_PV_DP_DEF                                                                                                                       |
+| Description    | Indicates the maximum data payload. This is the maximum number of octets allowed in the data field of T.127 MBFT start and data PDUs. |
+
+**Table I.7-89/T.180**
+
+|                |                                                                                                                                                                                                              |
+|----------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_MBF_P_COMPR                                                                                                                                                                                                |
+| Type of value  | unsigned long                                                                                                                                                                                                |
+| Legal values   | PV_TRUE<br>PV_FALSE                                                                                                                                                                                          |
+| Default value  | PV_FALSE                                                                                                                                                                                                     |
+| Description    | This parameter is used to negotiate use of V.42 <i>bis</i> compression for file data. T.127 MBFT protocol modules should assert this capability if they are able to receive V.42 <i>bis</i> compressed data. |
+
+**Table I.7-90/T.180**
+
+|                |                                                                                                                                                          |
+|----------------|----------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_MBF_P_NB_OF_CWOR                                                                                                                                       |
+| Type of value  | unsigned long                                                                                                                                            |
+| Legal values   | X_MBF_PV_CW_DEF      Default value (512 codewords)<br>X_MBF_PV_CW_NUM      Total number of codewords (less or equal 65 536).                             |
+| Default value  | X_MBF_PV_CW_DEF                                                                                                                                          |
+| Description    | Specifies the total number of codewords to be used by the V.42 <i>bis</i> compression algorithm. This is an upper bound on V.42 <i>bis</i> parameter P1. |
+
+**Table I.7-91/T.180**
+
+|                |                                                                                                                                   |
+|----------------|-----------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_MBF_P_MAX_STR_LNGH                                                                                                              |
+| Type of value  | unsigned long                                                                                                                     |
+| Legal values   | X_MBF_PV_STR_DEF      Default value (6)<br>X_MBF_PV_STR_VAL      Maximum string length (less or equal 250)                        |
+| Default value  | X_MBF_PV_STR_DEF                                                                                                                  |
+| Description    | Specifies the maximum string length input to the V.42 <i>bis</i> encoder. This is an upper bound on V.42 <i>bis</i> parameter P2. |
+
+**Table I.7-92/T.180**
+
+|                |                                                                                                            |
+|----------------|------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_MBF_P_NON_STD_CAP                                                                                        |
+| Type of value  | unsigned long                                                                                              |
+| Legal values   | X_MBF_PV_NSC_UNSP      Unspecified                                                                         |
+| Default value  | X_MBF_PV_NSC_UNSP                                                                                          |
+| Description    | This parameter is used to negotiate non-standard functions, including non-standard compression techniques. |
+
+**Table I.7-93/T.180**
+
+|                |                                                                                                                                                                                                                                                                                                                                              |
+|----------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Parameter name | X_MBF_P_CHR_RESULT                                                                                                                                                                                                                                                                                                                           |
+| Type of value  | unsigned long                                                                                                                                                                                                                                                                                                                                |
+| Legal values   | X_MBF_PV_CHR_SUCC      Success;<br>X_MBF_PV_R_T_CON      Rejection; temporary congestion;<br>X_MBF_PV_R_DOM_DIS      Rejection; conference domain disconnected;<br>X_MBF_PV_R_TM_RES      Rejection; too many resources;<br>X_MBF_PV_R_TM_USER      Rejection; too many users;<br>X_MBF_PV_R_NO_REASON      Rejection, reason not specified. |
+| Default value  | X_MBF_PV_CHR_SUCC                                                                                                                                                                                                                                                                                                                            |
+| Description    | Indicates the success or failure of the Change Resource Request.                                                                                                                                                                                                                                                                             |
+
+#### I.7.7.4 Disconnect Service
+
+##### I.7.7.4.1 Service description
+
+The Disconnect service is used to disconnect a member from the session. The Disconnect may be performed:
+
+- by any session member;
+- by the session provider.
+
+The Disconnect service does not guarantee delivery of information once the release phase is entered.
+
+The service elements and their corresponding XAPI functions needed for disconnection are described in Table I.7-94.
+
+**Table I.7-94/T.180 – Service elements and their corresponding XAPI functions for Disconnect**
+
+| Service element       | XAPI function | Description                                                                                                                     |
+|-----------------------|---------------|---------------------------------------------------------------------------------------------------------------------------------|
+| Disconnect Request    | x_snddis()    | The Disconnect Request is passed to the provider to request a session disconnection.                                            |
+| Disconnect Indication | x_rcvdis()    | The Disconnect Indication is generated by the provider to indicate the session disconnection initiated by the session provider. |
+| End Indication        | x_rcvend()    | The End Indication is generated by the provider to indicate that the service provider is ready to establish a new connection.   |
+
+##### I.7.7.4.2 Service Parameters
+
+There are no MBFT protocol-specific parameters of the Disconnect service.
+
+##### I.7.7.5 Tables of error codes
+
+The XAPI error-level error codes are defined in Annex B.
+
+##### I.7.7.5.1 CC\_BADVALUE
+
+If the cause code indicates a parameter error with a bad value, the value of *diagnostic* will contain the erroneous parameter identifier which has been submitted with the XAPI function call that caused the error indication.
+
+##### I.7.7.5.2 CC\_MANDMISS
+
+If the cause code indicates a mandatory parameter is missing, the value of *diagnostic* will contain the missing parameter identifier that caused the error indication.
+
+##### I.7.7.5.3 CC\_BADEVENT
+
+If the cause code indicates a bad event, the value of *diagnostic* will contain the bad event identifier which has been submitted with the XAPI function call that caused the error indication.
+
+#### **I.7.7.5.4 CC\_UNEXPECT**
+
+If the cause code indicates a unexpected event, the value of *diagnostic* will contain the actual state identifier in which the unexpected event caused the error indication.
+
+#### **I.7.7.5.5 CC\_NOTSUPPORT**
+
+If the cause code indicates an unsupported event, the value of *diagnostic* will contain the identifier of the unsupported event which has been submitted with the XAPI function call that caused the error indication.
+
+#### **I.7.7.5.6 CC\_OTHER**
+
+If the cause code indicates the CC\_OTHER error code, the value of *diagnostic* will contain the identifier which caused the error indication.
+
+## **APPENDIX II**
+
+### **Tutorial: XAPI and selected providers**
+
+This appendix describes the overall structure of selected providers and gives some information with respect to the XAPI. Subclauses I.4 (ACSE/ROSE), I.6 (T.120 Conference Control), and I.7 (MBFT) supply the reader with the full information needed to access these providers via the XAPI.
+
+#### **II.1 XAPI and the ACSE/ROSE provider**
+
+In this subclause the overall structure of the OSI Association Control Service Element (ACSE) and the OSI Remote Operation Service Element (ROSE) is presented. These services describe the communication between two OSI application entities, namely an invoking (or client) application entity, a performing (or server) application entity and their usage of remote operation services.
+
+The application entities will first establish an application association and then, in the connected state, will use remote operations for communication purposes.
+
+ACSE provides the elements that are used to manage the establishment and release of an application association. The association control service is provided by the service primitives:
+
+- A-ASSOCIATE request/indication/response/confirmation;
+- A-RELEASE request/indication/response/confirmation;
+- A-ABORT request/indication;
+- A-P-ABORT indication.
+
+Recommendation X.227 specifies the protocol for the ACSE. The protocol data units are listed below:
+
+- A-ASSOCIATE-REQUEST application-protocol-data-unit (AARQ);
+- A-ASSOCIATE-RESPONSE application-protocol-data-unit (AARE);
+- A-RELEASE-REQUEST application-protocol-data-unit (RLRQ);
+- A-RELEASE-RESPONSE application-protocol-data-unit (RLRE);
+- A-ABORT application-protocol-data-unit (ABRT).
+
+ROSE provides the capability to request that a process be executed on the same or on another system. It passes a description of the operation and associated parameters from the client to the server that may provide a result on the outcome. The ROSE services are provided in conjunction with the ACSE.
+
+The remote operation service is provided by the service primitives:
+
+- RO-INVOKE request/indication;
+- RO-RESULT request/indication;
+- RO-ERROR request/indication;
+- RO-REJECT-U request/indication;
+- RO-REJECT-P indication.
+
+Recommendation X.229 specifies the protocol and procedures for the ROSE. The protocol data units are listed below:
+
+- RO-INVOKE application-protocol-data-unit (ROIV);
+- RO-RESULT application-protocol-data-unit (RORS);
+- RO-ERROR application-protocol-data-unit (ROER);
+- RO-REJECT application-protocol-data-unit (RORJ).
+
+Figure II.1 shows the structure of the protocol stack that is accessible via the XAPI when selecting an provider comprising ACSE and ROSE. The ROSE service is provided by the combination of a Transport system, the Session, the Presentation, and the ROSE protocol module, selected by the application.
+
+![Diagram of the ACSE/ROSE provider structure showing the protocol stack layers and their connections.](dd49b205277adfeab9df64f5dc4c402c_img.jpg)
+
+The diagram illustrates the structure of the ACSE/ROSE provider. At the top, a box labeled 'XAPI user' is connected to a horizontal line representing the 'XAPI' interface. Below this line, a vertical line labeled 'Fd-AR' connects to a large shaded rectangular area representing the 'service provider'. Inside this area, the protocol stack is shown as a series of stacked boxes: 'X.227 protocol module (ACSE)' and 'X.229 protocol module (ROSE)' are at the top, both connected to 'X.226 protocol module (Present.)'. This is followed by 'X.225 protocol module (Session)', and at the bottom is a box labeled 'transport system comprising layers 1-4'. A bracket on the left side of the shaded area is labeled 'service provider'. The text 'T0827350-97' is located at the bottom right of the diagram.
+
+Diagram of the ACSE/ROSE provider structure showing the protocol stack layers and their connections.
+
+**Figure II.1/T.180 – Structure of the ACSE/ROSE provider**
+
+Figure II.2 shows the client/server model. Both systems are structured as shown in Figure II.1. In addition, two ROSE protocol-data-units are depicted which may serve as examples for the communication between the two application entities.
+
+An application can:
+
+- invoke operations by one ROSE user and perform operations by an other ROSE user;
+- perform the control of the application association by ACSE.
+
+![Diagram of a client/server model based on XAPI ACSE/ROSE provider.](33af44bc1e5166e9cc1f4f29077ee09b_img.jpg)
+
+The diagram illustrates a client/server model based on XAPI ACSE/ROSE provider. It shows two identical system architectures connected by two horizontal arrows. Each system architecture consists of an 'XAPI user client' box at the top, connected to a thick horizontal line labeled 'XAPI'. Below this line is a box labeled 'Fd-AR-client'. Inside the 'Fd-AR-client' box are three sub-components: 'X.227', 'X.229', and 'X.226'. 'X.227' and 'X.229' are connected to 'X.226'. Below 'X.226' are three black dots. The two systems are connected by two horizontal arrows: the top arrow points from left to right and is labeled 'ROIV', and the bottom arrow points from right to left and is labeled 'RORS'. The identifier 'T0827360-97' is located at the bottom right of the diagram.
+
+Diagram of a client/server model based on XAPI ACSE/ROSE provider.
+
+**Figure II.2/T.180 – Client/server model based on XAPI ACSE/ROSE provider**
+
+Figure I.3 shows an example sequence of XAPI function calls. The client system initiates an association, connecting the client to the server. Afterwards, and in the connected state, the client requests a remote service operation which is performed by the server. The positive reply is returned to the client.
+
+![Sequence diagram showing the interaction between Fd-AR-client and Fd-AR-server. The diagram illustrates the sequence of events for an A-ASSOCIATE and RO-INVOKE operation. On the client side, x_conreq (A-ASSOCIATE req.) is sent, followed by x_sndsp (RO-INVOKE req.), and x_rcvsp (RO-RESULT ind.). On the server side, x_conind (A-ASSOCIATE ind.) is received, followed by x_rcvsp (RO-INVOKE ind.), and x_sndsp (RO-RESULT req.). The server also sends x_conrsp(+) [A-ASSOCIATE rsp.(+)] back to the client. The client then sends x_conconf(+) [A-ASSOCIATE conf.(+)] back to the server. The sequence ends with three dots indicating further interactions.](733da1815169d31c06238e8cd6ae23f2_img.jpg)
+
+```
+
+sequenceDiagram
+    participant Client as Fd-AR-client
+    participant Server as Fd-AR-server
+
+    Client->>Server: x_conreq (A-ASSOCIATE req.)
+    Server->>Server: x_conind (A-ASSOCIATE ind.)
+    Server->>Client: x_conrsp(+) [A-ASSOCIATE rsp.(+)]
+    Client->>Server: x_conconf(+) [A-ASSOCIATE conf.(+)]
+    Client->>Server: x_sndsp (RO-INVOKE req.)
+    Server->>Server: x_rcvsp (RO-INVOKE ind.)
+    Server->>Client: x_sndsp (RO-RESULT req.)
+    Client->>Server: x_rcvsp (RO-RESULT ind.)
+    Note over Client, Server: ...
+  
+```
+
+Sequence diagram showing the interaction between Fd-AR-client and Fd-AR-server. The diagram illustrates the sequence of events for an A-ASSOCIATE and RO-INVOKE operation. On the client side, x\_conreq (A-ASSOCIATE req.) is sent, followed by x\_sndsp (RO-INVOKE req.), and x\_rcvsp (RO-RESULT ind.). On the server side, x\_conind (A-ASSOCIATE ind.) is received, followed by x\_rcvsp (RO-INVOKE ind.), and x\_sndsp (RO-RESULT req.). The server also sends x\_conrsp(+) [A-ASSOCIATE rsp.(+)] back to the client. The client then sends x\_conconf(+) [A-ASSOCIATE conf.(+)] back to the server. The sequence ends with three dots indicating further interactions.
+
+T0827370-97
+
+**Figure II.3/T.180 – An example sequence**
+
+A service endpoint (e.g. Fd-AR-client) accessing the ACSE/ROSE provider is created when using the `x_open` function and is activated when using the `x_bind` function:
+
+`x_open`
+
+- Name of the service provider ("X\_ACSE\_ROSE\_ISDN");
+- Execution mode;
+- Information (e.g. characteristics of the local service provider);
+- `xerror` (error codes or the parameter *Fd-AR-client*).
+
+`x_bind`
+
+- Fd-AR-client;
+- Name of the transport system (not needed in the standard configuration);
+- Requested own protocol address;
+- Bound own protocol address;
+- Information;
+- `xerror` (error codes).
+
+In the standard configuration, if "X\_ACSE\_ROSE\_ISDN" was selected in the `x_open` function, no transport system has to be specified as argument of the `x_bind` function as the service provider's protocol stack is already complete.
+
+Connection establishment is performed by ACSE. The address to be used to identify the peer entity (called address) is the tuple of (Presentation-selector, Session-selector, Transport-selector, NSAP Address), where the selectors are optional depending on the peer's requirements.
+
+x\_conreq
+
+- Fd-AR-client,
+- Called address (see above), user data, protocol parameters (see below),
+- xerror.
+
+The protocol parameters are listed below (list not complete). For brevity, only those parameters are listed which apply for the Request primitive and which are mandatory for this primitive.
+
+- X\_ACS\_P\_APP\_CTXT: This parameter identifies the application context. In the Response or Confirmation primitive either the same or a different application context is returned.
+- X\_ACS\_P\_CTXT\_ID: This parameter identifies the presentation context identification.
+- X\_ACS\_P\_AS: This parameter indicates the abstract syntax name.
+- X\_ACS\_P\_SUR: This parameter indicates the session user requirements.
+
+ROSE defines five different Operation Classes which classify operations according to two possible operation modes (synchronous and asynchronous). The Association Class defines which ROSE user is allowed to invoke operations. The Operation Class and Association Class have to be agreed between ROSE users. It is not part of the ROSE provider to negotiate these features. OSI Applications making use of ROSE (e.g. DTAM, MHS) define which Operation Class and Association Class are allowed within a specific application.
+
+Due to the fact that there is no negotiation of Operation and Association Classes within the ROSE provider, the parameters Invoke-Id (to identify an operation and to correlate the request of an invocation with its replies) and Linked-Id (in the case of a child operation to identify the parent operation) can not be examined by ROSE. Especially it is not controlled, if an invocation exists to an incoming reply, i.e. result, error or rejection or if the specified parent operation exists to the invocation of an child operation.
+
+ROSE does not define a distinct abstract syntax for the encoding of its PDUs. Instead, it provides a set of abstract syntax definitions that are used by the application making use of ROSE. Therefore, the service user must inform the service provider which abstract syntax are used within the ROSE PDUs. To support this feature, each ROSE service primitive must be provided with a service primitive parameter (X\_ROS\_P\_CTXT\_ID) that indicates the abstract syntax of the application.
+
+While the service endpoint used to access the provider is in the connected state, the corresponding service primitives can be passed to the provider or retrieved from the provider using the XAPI function calls x\_sndsp and x\_rcvsp.
+
+x\_sndsp/x\_rcvsp
+
+- Fd-AR-client;
+- Level (identifies the protocol module which shall get the service primitive);
+- Spname (e.g. RO-INVOKE);
+- Sp (parameters of the service primitive (see below) and user data);
+- xerror.
+
+The RO-INVOKE primitive is used to request the start of a remote operation. The parameters of this primitive are listed below.
+
+- X\_ROS\_P\_CTXT\_ID: This parameter indicates the presentation context identification of the application data of the RO-INVOKE primitive. This parameter is the presentation context identification which was negotiated in the ACSE establishment for the application.
+- X\_ROS\_P\_INV\_ID: This parameter identifies the RO-INVOKE primitive and is used to correlate this primitive with the corresponding replies.
+- X\_ROS\_P\_LINK\_ID: This parameter identifies a child-operation and identifies the invocation of the linked parent-operation. The value is that of the X\_ROS\_P\_INV\_ID parameter of the RO-INVOKE indication primitive of the parent-operation.
+- X\_ROS\_P\_VAL\_INT: This parameter indicates the identifier of the operation to be invoked. As the identifier of the operation may either be an integer value or an object identifier, either this parameter (legal values are any integer values) or the parameter X\_ROS\_P\_VAL\_ID may be present.
+- X\_ROS\_P\_VAL\_ID: This parameter indicates the identifier of the operation to be invoked. As the identifier of the operation may either be an integer value or an object identifier, either this parameter or the parameter X\_ROS\_P\_VAL\_INT may be present.
+
+## **II.2 XAPI and the specific T.120 conference provider**
+
+### **II.2.1 The T.120 system model**
+
+The T.120 protocol provides a means of telecommunicating all forms of data/telematic media between two or more multimedia terminals and of managing such communication. They provide a multipoint data communication service that has a particular application in multimedia conferencing.
+
+The T.120 protocol can handle one or more simultaneous "conferences"; any terminal may participate in more than one of these if authorized to do so; the convener of any one conference may control the participation in that conference and the flow of information in that conference.
+
+Audio/Video applications and/or data applications such as File Transfer or Still Image may be used in a conference.
+
+Figure II.4 shows the structure of a T.120-series-based Conference platform. Furthermore, the location of the XAPI is depicted.
+
+![Figure II.4/T.180 – Structure of a T.120-series conference terminal. The diagram shows a hierarchical structure starting from a 'User of the conference' at the top, connected to a 'Man-machine interface'. This interface has two 'Control/Data' paths leading to a 'Conference Shell (eventually void)'. The shell is divided into two parts: 'Conference Control User Part' and 'Conference-Data Applications User Part'. These parts connect to the 'XAPI' layer via service endpoints 'Fd-cc' and 'Fd-ai' respectively. The 'Fd-cc' path leads to a 'Node Controller', and the 'Fd-ai' path leads to 'Application Protocol Entities (T.126, T.127...)'. Both of these connect to a 'Generic Conference Control T.124 (GCC)', which then connects to a 'Multipoint Communication Service T.122/T.125 (MCS)', and finally to 'Network Transport Protocols (T.123)' at the bottom. A reference 'T0827380-97' is noted at the bottom right.](b6453246018f11d6b771d4e0a3976328_img.jpg)
+
+Figure II.4/T.180 – Structure of a T.120-series conference terminal. The diagram shows a hierarchical structure starting from a 'User of the conference' at the top, connected to a 'Man-machine interface'. This interface has two 'Control/Data' paths leading to a 'Conference Shell (eventually void)'. The shell is divided into two parts: 'Conference Control User Part' and 'Conference-Data Applications User Part'. These parts connect to the 'XAPI' layer via service endpoints 'Fd-cc' and 'Fd-ai' respectively. The 'Fd-cc' path leads to a 'Node Controller', and the 'Fd-ai' path leads to 'Application Protocol Entities (T.126, T.127...)'. Both of these connect to a 'Generic Conference Control T.124 (GCC)', which then connects to a 'Multipoint Communication Service T.122/T.125 (MCS)', and finally to 'Network Transport Protocols (T.123)' at the bottom. A reference 'T0827380-97' is noted at the bottom right.
+
+**Figure II.4/T.180 – Structure of a T.120-series conference terminal**
+
+The XAPI conference user (see Figure 12) comprises the user parts of:
+
+- the Conference Control communicating with the provider (i.e. the Node Controller) via the service endpoint Fd-cc,
+- zero, one or more (standard or non-standard) Data Applications each communicating with the provider via a separate service endpoint Fd-a1, ..., -ak.
+
+A Conference Shell functionality making the access of a human user to conference services easier may or may not be part of the XAPI user.
+
+The XAPI conference provider comprises the:
+
+- Node Controller;
+- (standard or non-standard) Data Application Protocol Entities;
+- the remaining provider functions as shown in Figure II.4 (GCC, MCS, ...).
+
+The term "Node Controller" is used to describe the element that provides the T.120 management function or role at a terminal or Multipoint Control Unit (MCU).
+
+The T.124 Generic Conference Control (GCC) provides a set of services for setting up and managing the multipoint conference.
+
+The T.122/T.125 Multipoint Communication Service (MCS) provides a general multipoint connection-oriented data service. It collects point-to-point Transport connections and combines them to form a Multipoint Domain. Within that Domain a large number of logical channels are provided that can provide one-to-one, one-to-many and many-to-one data delivery.
+
+## **II.2.2 T.120 MBFT conferencing**
+
+Recommendation T.127 defines the Multipoint Binary File Transfer (MBFT) Protocol. This protocol supports the interchange of binary files within an interactive conferencing or group working environment where the T.120-series of Recommendations is in use.
+
+A basic file transfer application conforming to this Recommendation may simply offer the ability to broadcast one file at a time to all applications which support the MBFT protocol. Optional advanced features defined in T.127 include:
+
+- broadcast of multiple files simultaneously;
+- "private" distribution of files to a selected subset of the conference;
+- conductor control of file distribution.
+
+Prior to activating a file transfer application, the user has to create or to join a conference (the node that creates a conference is called the convener). In general, the XAPI conference user at a terminal has access to conference management functions such as:
+
+- c1 information services to determine what conferences are currently in existence;
+- c2 creation of a conference;
+- c3 joining an existing conference;
+- c4 leaving a conference;
+- c5 adding a node to an existing conference;
+- c6 terminating the entire conference;
+- c7 forcing a particular node to be disconnected from a conference;
+- c8 requesting that an Application Protocol Entity be invoked at a specified set of nodes,
+- ... ..
+
+via the service endpoint *Fd-cc* (see Figure 12).
+
+Functions such as disconnecting a node from a conference are only defined for the convener or some other specific nodes.
+
+Figure II.5 shows an example configuration. User A (at terminal A) creates a call-through conference, i.e. A calls into MCU K and adds the users B (at terminal B) and C (at terminal C), which are called by that MCU.
+
+A Multipoint Control Unit (MCU) is a special network element that serves to connect terminals and other MCU's in a multipoint fashion.
+
+NOTE – The example given in Figure II.5 represents the same conference configuration as that given in clause 7 (e.g. Figure 7).
+
+![Diagram of a conference configuration showing Terminal A (convener) connected to MCU K, which is then connected to Terminal B and Terminal C.](99bc201efaff9a7c0a66a617b474a29c_img.jpg)
+
+```
+graph LR; A((Terminal A (convener))) --- K((MCU K)); K --- B((Terminal B)); K --- C((Terminal C))
+```
+
+The diagram illustrates a conference configuration. On the left, a circle represents 'Terminal A (convener)'. A horizontal line connects it to a central circle labeled 'MCU K'. From 'MCU K', two lines branch out to the right, connecting to two more circles: 'Terminal B' (top) and 'Terminal C' (bottom). Below 'Terminal C' is the text 'T0827390-97'.
+
+Diagram of a conference configuration showing Terminal A (convener) connected to MCU K, which is then connected to Terminal B and Terminal C.
+
+**Figure II.5/T.180 – An example conference configuration**
+
+Figure II.6 shows an example sequence at terminal A sketching the creation of the conference specified above in terms of XAPI function calls.
+
+![Sequence diagrams showing the creation of a conference. The first diagram shows the initial creation of a conference by Fd-cA, involving a request (x_conreq), a request to the Node Controller (GCC-Conference-Create rq.), and a confirmation (x_conconf(+)). The second diagram shows adding member B, involving a request (x_sndsp), a request to the Node Controller (GCC-Conference-Add rq.), and a confirmation (x_rcvsp). The third diagram shows adding member C, following a similar pattern. Each diagram includes a final state where all members are present and no applications are in use.](08246879b7e3340f5c7af67ca43e48ff_img.jpg)
+
+**Sequence Diagram 1: Initial Conference Creation**
+
+Participants: Fd-cA, Action of the Node Controller, other actions
+
+1. Fd-cA sends **x\_conreq** (requesting the creation of a conference) to Action of the Node Controller.
+
+2. Action of the Node Controller sends **creating a GCC-Conference-Create rq.** to other actions.
+
+3. other actions send a protocol element from K to A to Fd-cA.
+
+4. Fd-cA receives **x\_conconf(+)** (conference created) from other actions.
+
+Final State: A is member of the conference, no applications are in use.
+
+**Sequence Diagram 2: Adding Member B**
+
+Participants: Fd-cA, Action of the Node Controller, other actions
+
+1. Fd-cA sends **x\_sndsp** (A adds B to the conference) to Action of the Node Controller.
+
+2. Action of the Node Controller sends **creating a GCC-Conference-Add rq.** to other actions.
+
+3. other actions send a protocol element from A to K, which initiates the invitation of terminal B: GCC-Conference-Invite rq at K to Fd-cA.
+
+4. Fd-cA receives **x\_rcvsp** (B is added to the conference) from other actions.
+
+Final State: A and B are members of the conference, no applications are in use.
+
+**Sequence Diagram 3: Adding Member C**
+
+Participants: Fd-cA, Action of the Node Controller, other actions
+
+1. Fd-cA sends **x\_sndsp** (A adds C to the conference) to Action of the Node Controller.
+
+2. Action of the Node Controller sends **creating a GCC-Conference-Add rq.** to other actions.
+
+3. other actions send a protocol element from A to K, which initiates the invitation of terminal C: GCC-Conference-Invite rq at K to Fd-cA.
+
+4. Fd-cA receives **x\_rcvsp** (C is added to the conference) from other actions.
+
+Final State: A, B, and C are members of the conference, no applications are in use.
+
+T0827400-97
+
+Sequence diagrams showing the creation of a conference. The first diagram shows the initial creation of a conference by Fd-cA, involving a request (x\_conreq), a request to the Node Controller (GCC-Conference-Create rq.), and a confirmation (x\_conconf(+)). The second diagram shows adding member B, involving a request (x\_sndsp), a request to the Node Controller (GCC-Conference-Add rq.), and a confirmation (x\_rcvsp). The third diagram shows adding member C, following a similar pattern. Each diagram includes a final state where all members are present and no applications are in use.
+
+**Figure II.6/T.180 – Creation of a conference example sequence**
+
+The service endpoint Fd-cA accessing the conference control provider (Node Controller of terminal A) is created when using the x\_open function and is activated when using the x\_bind function:
+
+x\_open
+
+- Name of the service provider ("X\_T.120\_CONF\_ISDN", ...);
+
+- Execution mode;
+- Information (e.g. characteristics of the local service provider);
+- xerror (error codes or the parameter "Fd-cA").
+
+x\_bind
+
+- Fd-cA;
+- Requested own protocol address;
+- Bound own protocol address;
+- Information;
+- xerror.
+
+Communication establishment (creating a new conference at MCU K to which terminal A is automatically joined) is supervised by the Node Controller. User A initiates the function:
+
+x\_conreq
+
+- Fd-cA;
+- Called address, user data, protocol parameters (see below);
+- xerror.
+
+The protocol parameters are listed below (list not complete):
+
+- Conference Name: Name by which the conference to be created is identified;
+- Conference Locked: Setting this flag immediately locks a conference;
+- Conference Listed: The TRUE setting of this flag indicates that this conference may be listed;
+- Conference Conductible: The TRUE setting of this flag indicates that this conference may be placed in conducted mode;
+- Termination Method: This parameter indicates whether the conference shall remain in existence until explicitly terminated by the Convener or convener-designated node.
+
+Having successfully performed all actions shown in Figure II.6, the XAPI users A (convener), B and C are members of the conference. No applications are in use at this point in time. At that time, the control connection is defined by the tuple (Fd-cA, Fd-cB, Fd-cC, K). It consists in the GCC Broadcast Channel, the Convenor Channel, and – for each node – the Node ID channel (see Annex A/Recommendation T.120).
+
+In the remainder of this subclause, MBFT-related structures and actions are described.
+
+The conference user at a terminal has access to MBFT management and information transfer functions such as:
+
+- f1 connecting the MBFT application to the conference;
+- f2 offer a file;
+- f3 accept a file,
+- ...
+
+via the service endpoint Fd-file-transfer.
+
+The purpose of the example conference is to "broadcast" files from one participant to others. Therefore, a file transfer application is used which is supported by the MBFT T.127 protocol.
+
+Two types of channels are used within T.127: control channels and data channels. Control channels are used for managing all aspects of the file transfer (offering files, requesting files), whereas data channels are used exclusively for the transfer of file data. Only one file can be transmitted on each
+
+data channel at a time, but additional data channels can be used to allow distribution of multiple files simultaneously.
+
+Figure II.7 shows the terminals, the MCU, and the MBFT channel structure for the example configuration. MBFT-CHANNEL-0 is the name of the control channel and MBFT-CHANNEL-1 is the name of a broadcast data channel on which files are distributed. Fd-fA, Fd-fB, and Fd-fC are the respective service endpoints.
+
+![Diagram of the MBFT channel structure showing Terminal A, Terminal B, MCU K, and Terminal C connected via MBFT-CHANNEL-0 and MBFT-CHANNEL-1.](6a8b298a198b8ca2067f7adf3c8c6317_img.jpg)
+
+The diagram illustrates the MBFT channel structure for an example configuration involving four entities: Terminal A (convener), Terminal B, MCU K, and Terminal C.
+
+**Terminal A (convener) and Terminal B:** Each contains a **Conf. Control** block and a **File transfer user appl.** block. They are connected via an **XAPI** interface. Below this, there are **Fd-cA** and **Fd-fA** (for Terminal A) or **Fd-cB** and **Fd-fB** (for Terminal B) connections. These connect to a **Node Contr.** block, which is linked to an **MBFT T.127** block. Both are connected to a **GCC T.124** block, which in turn connects to an **MCS T.122/T.125** block.
+
+**MCU K:** Contains a **Node Contr.** block connected to a **GCC T.124** block, which connects to an **MCS T.122/T.125** block. It is connected to the network via an **XAPI** interface with **Fd-mcuK**.
+
+**Terminal C:** Similar to Terminals A and B, it contains **Conf. Control**, **File transfer user appl.**, **XAPI**, **Fd-cC**, **Fd-fC**, **Node Contr.**, **MBFT T.127**, **GCC T.124**, and **MCS T.122/T.125** blocks.
+
+**MBFT Channels:**
+
+- MBFT-CHANNEL-0 (Control Channel):** Represented by solid lines, it connects the **MCS T.122/T.125** blocks of Terminal A, Terminal B, MCU K, and Terminal C.
+- MBFT-CHANNEL-1 (Data Channel):** Represented by dashed lines, it connects the **MBFT T.127** blocks of Terminal A, Terminal B, and Terminal C.
+
+T0827410-97
+
+Diagram of the MBFT channel structure showing Terminal A, Terminal B, MCU K, and Terminal C connected via MBFT-CHANNEL-0 and MBFT-CHANNEL-1.
+
+**Figure II.7/T.180 – The MBFT channel structure (example)**
+
+Other channels, such as the GCC Broadcast Channel, or the Convener Channel are not shown in Figure II.7.
+
+NOTE – In general, the functionality of a MCU will differ from that of a terminal. Nevertheless, using a XAPI for MCUs as shown in Figure II.7 may contribute to a more sophisticated architecture of such a node and may ease software development.
+
+A MBFT session is characterized by:
+
+- a single control channel (see Figure II.7);
+- a single broadcast data channel (see Figure II.7);
+- zero or more acknowledged data channels (not used for the example);
+- zero or more private sub-sessions (not used for the example);
+- a session ID.
+
+A MBFT session may now be initiated locally by the user application or remotely through use of the GCC-Application-Invoke mechanism.
+
+Figure II.8 shows user A connecting the file transfer application to the conference and receiving a file.
+
+![Sequence diagram showing the interaction between Fd-fA and the MBFT T.127 protocol for connecting a file transfer application and receiving a file.](4e453d478a82d0f883c69bbf1a6afe41_img.jpg)
+
+```
+
+sequenceDiagram
+    participant Fd-fA
+    participant MBFT_T127 as Actions of the MBFT T.127 protocol (and related actions)
+
+    Fd-fA->>MBFT_T127: x_conreq  
+(initiating a MBFT Standard Base Session)
+    MBFT_T127->>GCC: GCC-Permission-To-Enroll ind.
+    MBFT_T127->>MCS: MCS-Attach-User req.
+    MBFT_T127->>MCS: MCS-Attach-User con.  
+(getting the MBFT User ID)
+    MBFT_T127->>MCS: MCS-Channel-Join req.  
+(Channel ID = MBFT User ID)
+    MBFT_T127->>MCS: MCS-Channel-Join con.  
+(User ID channel joined)
+    MBFT_T127->>MCS: MCS-Channel-Join req.  
+(Channel ID = MBFT-CHANNEL-0)
+    MBFT_T127->>MCS: MCS-Channel-Join con.  
+(control channel joined)
+    MBFT_T127->>MCS: MCS-Channel-Join req.  
+(Channel ID = MBFT-CHANNEL-1)
+    MBFT_T127->>MCS: MCS-Channel-Join con.  
+(data channel joined)
+    Note over MBFT_T127: ...
+    MBFT_T127->>GCC: GCC-Application-Enroll req.  
+(Active, Session ID)
+    MBFT_T127->>GCC: GCC-Application-Enroll con.
+    GCC->>MBFT_T127: GCC-Application-Roster-Report ind.
+    MBFT_T127->>Fd-fA: x_conconf(+)
+    MBFT_T127->>Fd-fA: x_rcvsp [obtain a File-OfferPDU (MBFT-CHANNEL-0)]
+    MBFT_T127->>Fd-fA: x_rcvsp [obtain a File-StartPDU (MBFT-CHANNEL-1)]
+    MBFT_T127->>Fd-fA: x_rcvdata [obtain a File-DataPDU (MBFT-CHANNEL-1)]
+    Note over MBFT_T127: ...
+  
+```
+
+T0827420-97
+
+Sequence diagram showing the interaction between Fd-fA and the MBFT T.127 protocol for connecting a file transfer application and receiving a file.
+
+**Figure II.8/T.180 – User A: Connecting the file transfer application to the conference and receiving a file**
+
+After having obtained a MBFT User ID, the T.127 protocol shall join control and data channels by issuing two MCS-Channel-Join requests, specifying MBFT-CHANNEL-0 and MBFT-CHANNEL-1 as respective channels to join. Once positive confirmation of joining these channels has been received ("channel joined" in Figure II.8), the application shall enrol active by issuing a GCC-Application-Enrol request from the T.127 protocol to the GCC provider.
+
+Afterwards, files may be exchanged. Figure II.8 shows the receipt of a file.
+
+A service endpoint (e.g. Fd-fA) accessing the MBFT T.127 protocol is created when using the `x_open` function and is activated when using the `x_bind` function:
+
+`x_open`
+
+- Name of the service provider ("X\_T.127\_MBFT", ...);
+- Execution mode;
+- Information (e.g. characteristics of the local service provider);
+- `xerror` (error codes or the parameter "Fd-fA").
+
+`x_bind`
+
+- Fd-fA;
+- `xerror`.
+
+During the connection establishment phase, an MBFT user establishes a connection (i.e. creating a new session or joining an already existing session) to other MBFT users. The connection is identified by the conference name and the session identifier respectively.
+
+`x_conreq`
+
+- Fd-fA;
+- Conference name, session type, session identifier, other parameters;
+- `xerror`.
+
+Some protocol parameters are listed below:
+
+- Conference Name: Name by which the conference is identified;
+- Session type: Parameter by means of which the session type is identified;
+- Session Identifier: Number by which the session is identified;
+- Other parameters: e.g. indicating the maximum file size, negotiating use of V.42 *bis* compression for file data, ...
+
+NOTE – In the example above the application connection is defined by (Fd-fA, Fd-fB, Fd-fC). It consists in MBFT-CHANNEL-0, MBFT-CHANNEL-1, and – for each MBFT application protocol entity – the MBFT User ID Channel.
+
+## ITU-T RECOMMENDATIONS SERIES
+
+|                 |                                                                                                                                |
+|-----------------|--------------------------------------------------------------------------------------------------------------------------------|
+| Series A        | Organization of the work of the ITU-T                                                                                          |
+| Series B        | Means of expression: definitions, symbols, classification                                                                      |
+| Series C        | General telecommunication statistics                                                                                           |
+| Series D        | General tariff principles                                                                                                      |
+| Series E        | Overall network operation, telephone service, service operation and human factors                                              |
+| Series F        | Non-telephone telecommunication services                                                                                       |
+| Series G        | Transmission systems and media, digital systems and networks                                                                   |
+| Series H        | Audiovisual and multimedia systems                                                                                             |
+| Series I        | Integrated services digital network                                                                                            |
+| Series J        | Transmission of television, sound programme and other multimedia signals                                                       |
+| Series K        | Protection against interference                                                                                                |
+| Series L        | Construction, installation and protection of cables and other elements of outside plant                                        |
+| Series M        | TMN and network maintenance: international transmission systems, telephone circuits, telegraphy, facsimile and leased circuits |
+| Series N        | Maintenance: international sound programme and television transmission circuits                                                |
+| Series O        | Specifications of measuring equipment                                                                                          |
+| Series P        | Telephone transmission quality, telephone installations, local line networks                                                   |
+| Series Q        | Switching and signalling                                                                                                       |
+| Series R        | Telegraph transmission                                                                                                         |
+| Series S        | Telegraph services terminal equipment                                                                                          |
+| <b>Series T</b> | <b>Terminals for telematic services</b>                                                                                        |
+| Series U        | Telegraph switching                                                                                                            |
+| Series V        | Data communication over the telephone network                                                                                  |
+| Series X        | Data networks and open system communications                                                                                   |
+| Series Y        | Global information infrastructure                                                                                              |
+| Series Z        | Programming languages                                                                                                          |
\ No newline at end of file
diff --git a/marked/T/T-REC-T.192-199806-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/T/T-REC-T.192-199806-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..96136846cbe9673733a28f2a181256d07f7f8180
--- /dev/null
+++ b/marked/T/T-REC-T.192-199806-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:2eebe57da2cd011b7a2d919d33b57dd168b1c5ddf77eedae7ae1d6101841a8d1
+size 8368
diff --git a/marked/T/T-REC-T.192-199806-I_PDF-E/76b0cd79baaedd942af4dc42f2e764b8_img.jpg b/marked/T/T-REC-T.192-199806-I_PDF-E/76b0cd79baaedd942af4dc42f2e764b8_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..226fd54c36405fec17afb1fcf1ccb214b7bc473e
--- /dev/null
+++ b/marked/T/T-REC-T.192-199806-I_PDF-E/76b0cd79baaedd942af4dc42f2e764b8_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:b8d0aa06b72f144ba41c83dc78b212135fab1758734ff6b33db927c8b48157e7
+size 62906
diff --git a/marked/T/T-REC-T.192-199806-I_PDF-E/raw.md b/marked/T/T-REC-T.192-199806-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..edad6925bc30236ebeecab06c1a60f71d412febf
--- /dev/null
+++ b/marked/T/T-REC-T.192-199806-I_PDF-E/raw.md
@@ -0,0 +1,2232 @@
+
+
+![ITU logo: a globe with the letters ITU inside, and a lightning bolt striking the globe.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg)
+
+ITU logo: a globe with the letters ITU inside, and a lightning bolt striking the globe.
+
+INTERNATIONAL TELECOMMUNICATION UNION
+
+# ITU-T
+
+TELECOMMUNICATION  
+STANDARDIZATION SECTOR  
+OF ITU
+
+# T.192
+
+(06/98)
+
+SERIES T: TERMINALS FOR TELEMATIC SERVICES
+
+---
+
+**Cooperative Document Handling – Complex services: Joint synchronous editing and joint document presentation/viewing**
+
+ITU-T Recommendation T.192
+
+(Previously CCITT Recommendation)
+
+---
+
+# ITU-T T-SERIES RECOMMENDATIONS **TERMINALS FOR TELEMATIC SERVICES**
+
+*For further details, please refer to ITU-T List of Recommendations.*
+
+# **ITU-T RECOMMENDATION T.192**
+
+# **COOPERATIVE DOCUMENT HANDLING – COMPLEX SERVICES: JOINT SYNCHRONOUS EDITING AND JOINT DOCUMENT PRESENTATION/VIEWING**
+
+## **Summary**
+
+This Recommendation specifies document communication services to be provided on top of existing base standards or profiles, giving constraints on them and rules on how to use and combine them.
+
+Recommendation T.190 specifies basic services, such as storing, retrieval, manipulation, pointing or token-interchange. Some of these basic services can be used as stand-alone services, but all of them are candidates to build more complex services, such as joint synchronous editing and joint document presentation/viewing.
+
+This Recommendation specifies complex document communication services that are built on top of the basic ones.
+
+## **Source**
+
+ITU-T Recommendation T.192 was prepared by ITU-T Study Group 8 (1997-2000) and was approved under the WTSC Resolution No. 1 procedure on the 18th of June 1998.
+
+## FOREWORD
+
+ITU (International Telecommunication Union) is the United Nations Specialized Agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the ITU. The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis.
+
+The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics.
+
+The approval of Recommendations by the Members of the ITU-T is covered by the procedure laid down in WTSC Resolution No. 1.
+
+In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC.
+
+## NOTE
+
+In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+## INTELLECTUAL PROPERTY RIGHTS
+
+The ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. The ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process.
+
+As of the date of approval of this Recommendation, the ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementors are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database.
+
+© ITU 1998
+
+All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU.
+
+# CONTENTS
+
+|                                                                         | <i>Page</i> |
+|-------------------------------------------------------------------------|-------------|
+| 1 Scope .....                                                           | 1           |
+| 2 References .....                                                      | 1           |
+| 2.1 ITU-T Recommendations .....                                         | 1           |
+| 2.2 Additional references .....                                         | 2           |
+| 3 Definitions .....                                                     | 2           |
+| 4 Abbreviations .....                                                   | 2           |
+| 5 Introduction to document communication complex services .....         | 3           |
+| 5.1 Classification of complex services .....                            | 4           |
+| 5.2 Joint Synchronous Editing (SE) .....                                | 5           |
+| 5.2.1 Description .....                                                 | 5           |
+| 5.2.2 Service construction rules .....                                  | 6           |
+| 5.3 Joint document Presentation/Viewing (PV) .....                      | 7           |
+| 5.3.1 Joint document Presentation/Viewing with 1 presenter (PV1) .....  | 10          |
+| 5.3.1.1 Description .....                                               | 10          |
+| 5.3.1.2 Service construction rules .....                                | 10          |
+| 5.3.2 Joint document Presentation/Viewing with n presenters (PVn) ..... | 11          |
+| 5.3.2.1 Description .....                                               | 11          |
+| 5.3.2.2 Service construction rules .....                                | 11          |
+| 6 Document aspects concerning the SE and PV complex services .....      | 11          |
+| 6.1 Non-ODA documents .....                                             | 11          |
+| 7 Communication aspects concerning the SE and PV complex services ..... | 12          |
+| 7.1 Combined DTAM-DM and DTAM-TK (DTAM-DM/TK) .....                     | 12          |
+| 7.1.1 Description .....                                                 | 12          |
+| 7.1.2 Services, protocols and profiles .....                            | 12          |
+| 7.1.3 Use for document communication .....                              | 12          |
+| 7.2 Multipoint Communication Service (MCS) .....                        | 12          |
+| 7.2.1 Description .....                                                 | 12          |
+| 7.2.2 Services, protocols and profiles .....                            | 13          |
+| 7.2.3 Use for document communication .....                              | 13          |
+| 7.3 Generic Conference Control (GCC) .....                              | 13          |
+| 7.3.1 Description .....                                                 | 13          |
+| 7.3.2 Services, protocols and profiles .....                            | 13          |
+| 7.3.3 Use for document communication .....                              | 14          |
+| 8 Components and design rules for the SE and PV complex services .....  | 14          |
+| 8.1 Definition of document related service attributes .....             | 14          |
+| 8.1.1 The service attribute "document location" .....                   | 15          |
+| 8.1.2 The service attribute "document copies" .....                     | 16          |
+| 8.1.3 The service attribute "document access rights" .....              | 16          |
+| 8.1.4 The service attribute "store access rights" .....                 | 16          |
+| 8.1.5 The service attribute "document format" .....                     | 16          |
+| 8.1.6 The service attribute "functionality level" .....                 | 16          |
+| 8.1.7 The service attribute "document access order" .....               | 16          |
+
+|          |                                                                                                       |    |
+|----------|-------------------------------------------------------------------------------------------------------|----|
+| 8.2      | Definition of communication related service attributes.....                                           | 17 |
+| 8.2.1    | The service attribute "number of communicating entities".....                                         | 17 |
+| 8.2.2    | The service attribute "communication type" .....                                                      | 18 |
+| 8.2.3    | The service attribute "communication module" .....                                                    | 18 |
+| 8.2.4    | The service attribute "association" .....                                                             | 18 |
+| 8.2.5    | The service attribute "synchronization".....                                                          | 18 |
+| 8.2.6    | The service attribute "conference type" .....                                                         | 19 |
+| 8.3      | Definition of implementation related service attributes .....                                         | 19 |
+| 8.3.1    | The service attribute "basic services" .....                                                          | 19 |
+| 8.3.2    | The service attribute "static information".....                                                       | 20 |
+| 8.4      | Rules for the formal definition of complex services.....                                              | 20 |
+| 8.4.1    | Rules and notation for the assignment of values to the document related service attributes.....       | 20 |
+| 8.4.2    | Rules and notation for the assignment of values to the communication related service attributes.....  | 21 |
+| 8.4.3    | Rules and notation for the assignment of values to the implementation related service attributes..... | 22 |
+| 8.4.4    | Rules and notation for the selection of the communication modules.....                                | 22 |
+| 8.4.5    | Application rules .....                                                                               | 23 |
+| 9        | Formal definition of the SE complex service.....                                                      | 24 |
+| 9.1      | Document related service attributes .....                                                             | 24 |
+| 9.2      | Communication related service attributes .....                                                        | 25 |
+| 9.3      | Implementation related service attributes.....                                                        | 25 |
+| 9.4      | Selection of communication modules.....                                                               | 25 |
+| 9.5      | Application rules .....                                                                               | 26 |
+| 9.5.1    | Application rules when using DTAM-DM/TK.....                                                          | 26 |
+| 9.5.1.1  | Case 1: "association" = 'one-to-one' and "conference type" = 'fixed' .....                            | 26 |
+| 9.5.1.2  | Case 2: "association" = 'one-to-several' and "conference type" = 'fixed' .....                        | 28 |
+| 9.5.1.3  | Case 3: "association" = 'one-to-several' and "conference type" = 'flexible' .....                     | 31 |
+| 10       | Formal definition of the PV1 complex service .....                                                    | 33 |
+| 10.1     | Document related service attributes .....                                                             | 33 |
+| 10.2     | Communication related service attributes .....                                                        | 33 |
+| 10.3     | Implementation related service attributes.....                                                        | 34 |
+| 10.4     | Selection of communication modules.....                                                               | 34 |
+| 10.5     | Application rules .....                                                                               | 35 |
+| 10.5.1   | Application rules when using DTAM-DM/TK.....                                                          | 35 |
+| 10.5.1.1 | Case 1: "association" = 'one-to-one' and "conference type" = 'fixed' .....                            | 35 |
+| 10.5.1.2 | Case 2: "association" = 'one-to-several' and "conference type" = 'fixed' .....                        | 36 |
+| 10.5.1.3 | Case 3: "association" = 'one-to-several' and "conference type" = 'flexible' .....                     | 38 |
+| 11       | Formal definition of the PVn complex service .....                                                    | 40 |
+| 11.1     | Document related service attributes .....                                                             | 40 |
+| 11.2     | Communication related service attributes .....                                                        | 40 |
+| 11.3     | Implementation related service attributes.....                                                        | 40 |
+| 11.4     | Selection of communication modules.....                                                               | 41 |
+
+|                                                                                            | <i>Page</i> |
+|--------------------------------------------------------------------------------------------|-------------|
+| 11.5 Application rules .....                                                               | 41          |
+| 11.5.1 Application rules when using DTAM-DM/TK.....                                        | 42          |
+| 11.5.1.1 Case 1: "association" = 'one-to-one' and "conference type" = 'fixed' .....        | 42          |
+| 11.5.1.2 Case 2: "association" = 'one-to-several' and "conference type" = 'fixed' .....    | 43          |
+| 11.5.1.3 Case 3: "association" = 'one-to-several' and "conference type" = 'flexible' ..... | 45          |
+| Annex A – ASN.1 specification.....                                                         | 48          |
+| Appendix I – Implementation guidelines .....                                               | 49          |
+| I.1 General implementation guidelines .....                                                | 49          |
+| I.1.1 Quality of Service (QOS) .....                                                       | 49          |
+| I.1.2 Security .....                                                                       | 49          |
+| I.1.3 Handling documents in non-ODA formats .....                                          | 49          |
+| I.1.4 Complex services token distribution .....                                            | 50          |
+| I.1.5 Steps coordination in MCS.....                                                       | 50          |
+| I.1.6 Alternative implementation to the CSS .....                                          | 50          |
+| I.1.7 Leaving the session.....                                                             | 51          |
+| I.1.8 Handling of error situations .....                                                   | 51          |
+| I.2 Specific implementation hints for the SE complex service .....                         | 51          |
+| I.3 Specific implementation hints for the PV1 complex service .....                        | 51          |
+| I.4 Specific implementation hints for the PVn complex service .....                        | 52          |
+| Appendix II – Bibliography .....                                                           | 52          |
+| II.1 Document architectures.....                                                           | 52          |
+| II.1.1 Generic Abstract Interface.....                                                     | 52          |
+| II.2 Communication architectures.....                                                      | 52          |
+| II.2.1 Multipoint Communication Service (MCS) and Generic Conference Control (GCC) .....   | 52          |
+| II.2.2 Cooperative Document Handling (CDH) .....                                           | 53          |
+| II.2.3 Multipoint DTAM-DM (M-DTAM-DM) and Multipoint Remote Procedure Call (M-RPC).....    | 53          |
+| II.2.4 Profiles .....                                                                      | 53          |
+
+
+
+# COOPERATIVE DOCUMENT HANDLING – COMPLEX SERVICES: JOINT SYNCHRONOUS EDITING AND JOINT DOCUMENT PRESENTATION/VIEWING
+
+(Geneva, 1998)
+
+# 1 Scope
+
+The Open Document Architecture (ODA) base Recommendations | International Standards and associated profiles specify the means to represent and interchange complex documents.
+
+Communication base Recommendations | International Standards and associated profiles, specifying interchange, remote manipulation and management of documents at the application layer of the Open Systems Interconnection (OSI) Reference Model, have also been specified, as Document Transfer And Manipulation (DTAM) and Document Filing and Retrieval (DFR).
+
+Standards concerning multipoint communication and multimedia conferencing applications (see T.120 series of Recommendations) are being specified to support the needs of a rapidly growing telecommunication market.
+
+Standardizing document communication services will help implementors and service providers to extend the use and acceptance of these services in Europe. Furthermore, the standardization of document communication service profiles will facilitate interworking.
+
+This Recommendation specifies document communication services to be provided on top of existing base standards or profiles, giving constraints on them and rules on how to use and combine them.
+
+Recommendation T.190 specifies basic services, such as storing, retrieval, manipulation, pointing or token-interchange. Some of these basic services can be used as stand-alone services, but all of them are candidates to build more complex services, such as joint synchronous editing and joint document presentation/viewing.
+
+This Recommendation specifies complex document communication services that are built on top of the basic ones.
+
+# 2 References
+
+The following ITU-T Recommendations, and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; all users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published.
+
+## 2.1 ITU-T Recommendations
+
+- ITU-T Recommendation T.122 (1998), *Multipoint communication service – Service definition*.
+- ITU-T Recommendation T.124 (1998), *Generic Conference Control*.
+- ITU-T Recommendation T.125 (1994), *Multipoint communication service protocol specification*.
+- ITU-T Recommendation T.190 (1995), *Cooperative Document Handling (CDH) – Framework and basic services*.
+
+## 2.2 Additional references
+
+- ISO/IEC 9594:1995, *The Directory*.
+- ISO/IEC 10031-2:1991, *Information technology – Text and office systems – Distributed-office-applications model – Part 2: Distinguished-object-reference and associated procedures*.
+- ETS 300 498-1 (1996), *Open Document Architecture (ODA) – ODA communication services – Part 1: Basic services*.
+
+# 3 Definitions
+
+For the purposes of this Recommendation, all the definitions in Recommendation T.190 apply. In addition, this Recommendation defines the following terms.
+
+**3.1 central service server:** A server that controls the complex service token and centralizes the distribution of the document updates for a specific complex service. It is used to simplify the communication mechanism, since only one communication link between a user and the server is needed.
+
+**3.2 complex service session:** The whole of the processes and events in the time interval between initialization and termination of an application implementing a complex service.
+
+**3.3 initiator:** The user that initiates a complex service session.
+
+**3.4 master copy:** The copy of a document that is used as a reference. It is updated at the end of a complex service session.
+
+**3.5 moderator:** The user that is in charge of distributing the complex service token. It may be the initiator, a specific user, or the holder of the complex service token (in this case, the moderator role is changing during the complex service session).
+
+**3.6 presenter:** A user who presents the content and the structure of a document to other users (the viewers).
+
+**3.7 joint document Presentation/Viewing (PV) session:** A complex service session with the PV complex service.
+
+**3.8 PV token:** A token used in the PV session to indicate which user is in turn to access and present a document.
+
+**3.9 joint Synchronous Editing (SE) session:** A complex service session with the SE complex service.
+
+**3.10 SE token:** A token used in the SE session to indicate which user is in turn to access and manipulate a document.
+
+**3.11 viewer:** A user who follows the presentation of the content and the structure of a document provided by another user (the presenter).
+
+# 4 Abbreviations
+
+For the purposes of this Recommendation, all the abbreviations in Recommendation T.190 apply. In addition, this Recommendation uses the following abbreviations:
+
+|     |                                                  |
+|-----|--------------------------------------------------|
+| AEE | Associations Establishment End step              |
+| AEI | Associations Establishment Initiation step       |
+| AP  | Asynchronous document Production complex service |
+| AR  | Associations Release step                        |
+| CDH | Cooperative Document Handling                    |
+| CS  | Complex Service                                  |
+
+|             |                                                                                    |
+|-------------|------------------------------------------------------------------------------------|
+| CSS         | Central Service Server                                                             |
+| DTAM-DM/TK  | Combined Document Transfer And Manipulation – Document Manipulation/Token exchange |
+| DTAM-DM-SYM | Document Transfer and Manipulation – Document Manipulation – Symmetric             |
+| EWOS        | European Workshop for Open Systems                                                 |
+| FDS         | Final Document Synchronization step                                                |
+| GC          | GCC conference Creation step                                                       |
+| GCC         | Generic Conference Control                                                         |
+| GE          | GCC conference invitation End step                                                 |
+| GI          | GCC conference Invitation step                                                     |
+| GT          | GCC conference Termination step                                                    |
+| IDS         | Initial Document Synchronization step                                              |
+| ISSS        | Information Society Standardization System                                         |
+| MCJ         | MCS Channel Joining step                                                           |
+| MCR         | MCS Channel Release step                                                           |
+| MCS         | Multipoint Communication Service                                                   |
+| MCU         | Multipoint Control Unit                                                            |
+| MDE         | MCS Domain Establishment step                                                      |
+| MDR         | MCS Domain Release step                                                            |
+| M-DTAM-DM   | Multipoint – Document Transfer And Manipulation – Document Manipulation            |
+| M-RPC       | Multipoint – Remote Procedure Call                                                 |
+| MUA         | MCS Users Attachment step                                                          |
+| MUD         | MCS Users Detachment step                                                          |
+| O           | Operation step                                                                     |
+| PV          | Joint document Presentation/Viewing complex service                                |
+| PV1         | PV with 1 presenter                                                                |
+| PVn         | PV with n presenters                                                               |
+| SE          | Joint Synchronous Editing complex service                                          |
+| SM          | Selection/Management step                                                          |
+| SP          | Sequential document Production complex service                                     |
+| SP1         | SP with 1 document server                                                          |
+| SPn         | SP with n document servers                                                         |
+
+# 5 Introduction to document communication complex services
+
+This Recommendation specifies services for document communication. Basic services are specified in Recommendation T.190. This Recommendation specifies Complex Services (CS) with clause 5 providing an introduction and clauses 9, 10 and 11 providing the formal definition of the complex services.
+
+Complex services are built on top of basic services and make use of existing document and communication base Recommendations | International Standards and profiles.
+
+Six CS in four categories are considered, and a number is assigned to each CS:
+
+- Category 1: Joint Synchronous Editing (SE), which consists of:
+  - SE, joint synchronous editing (CS1).
+- Category 2: Joint document Presentation/Viewing (PV), which consists of:
+  - PV1, joint document presentation/viewing with 1 presenter (CS2);
+  - PVn, joint document presentation/viewing with n presenters (CS3).
+- Category 3: Sequential document Production (SP), which consists of:
+  - SP1, sequential document production with 1 document server (CS4);
+  - SPn, sequential document production with n document servers (CS5).
+- Category 4: Asynchronous document Production (AP), which consists of:
+  - AP, asynchronous document production (CS6).
+
+The complex services of category 1 (SE) and category 2 (PV) are specified in this Recommendation. The complex services of categories 3 (SP) and 4 (AP), both introduced in Recommendation T.190, are left for further study.
+
+## 5.1 Classification of complex services
+
+Table 1 classifies the complex services taking into account the following characteristics:
+
+- Granularity: Complex services working on:
+  - full documents; and/or
+  - document fragments.
+- Altering, or type of operations provided:
+  - Altering: Information in the document is modified.
+  - Non-altering: Information in the document is not modified.
+- Connectivity, or communicating entities relationships:
+  - one communicating entity associated to several communicating entities;
+  - several communicating entities associated to one communicating entity;
+  - several communicating entities associated to several communicating entities.
+- Synchronization:
+  - Synchronous: User access to the document(s) is controlled (and serialized) by means of the complex service (normally using a token handling mechanism).
+  - Asynchronous: User access to the document(s) may occur in random order (and is normally managed by an application).
+- Document production:
+  - Sequential production: A document is generated in a sequential manner, following certain rules.
+  - Non-sequential production: No rules are defined for the order in which different parts of a document need to be generated.
+  - No production: Documents are not produced with the complex service.
+
+- Use of the Multipoint Communication Service (MCS) (see Recommendations T.122 and T.125):
+  - No need: There is no need for MCS.
+  - Possible: MCS is useful, although other alternatives exist.
+
+**Table 1/T.192 – Classification of complex services**
+
+|                     |                                   | Complex services |     |     |     |     |    |
+|---------------------|-----------------------------------|------------------|-----|-----|-----|-----|----|
+|                     | Characteristics                   | SE               | PV1 | PVn | SP1 | SPn | AP |
+| Granularity         | Works on full documents           |                  |     |     | ✓   | ✓   |    |
+|                     | Works on document fragments       | ✓                | ✓   | ✓   | ✓   | ✓   | ✓  |
+| Altering            | Altering operations               | ✓                |     |     | ✓   | ✓   | ✓  |
+|                     | Non-altering operations           |                  | ✓   | ✓   |     |     |    |
+| Connectivity        | One to several comm. Entities     |                  | ✓   |     |     |     |    |
+|                     | Several to one comm. Entities     |                  |     |     | ✓   |     | ✓  |
+|                     | Several to several comm. Entities | ✓                |     | ✓   |     | ✓   |    |
+| Synchronization     | Synchronous                       | ✓                | ✓   | ✓   | ✓   | ✓   |    |
+|                     | Asynchronous                      |                  |     |     |     |     | ✓  |
+| Document production | Sequential production             |                  |     |     | ✓   | ✓   |    |
+|                     | Non-sequential production         | ✓                |     |     |     |     | ✓  |
+|                     | No production                     |                  | ✓   | ✓   |     |     |    |
+| MCS use             | No need for MCS                   |                  |     |     | ✓   | ✓   | ✓  |
+|                     | MCS may be used                   | ✓                | ✓   | ✓   |     |     |    |
+
+## 5.2 Joint Synchronous Editing (SE)
+
+For the SE complex service, the following subclauses give a description and some service construction rules, that highlight the basic services on which the complex service is founded and how these basic services are combined together. Figures 1 and 2 are used for this purpose. Let  $n$  be the number of users participating in a SE session,  $n > 1$ .
+
+### 5.2.1 Description
+
+The SE complex service consists of the remote editing of one or more documents by several users in an interactive and synchronous manner.
+
+The basic principles which constitute the SE complex service are:
+
+- Several pre-determined users cooperate to jointly edit one or more pre-determined documents. Although every user may have a full or partial copy of a document, only one copy is designated the master copy, in which the result of the joint editing is stored. The master copy may be stored in one of the user servers. Local copies of a document can be useful to avoid data transfer overheads when some users view a document.
+- One user will initiate the SE session. This user is called the initiator.
+- Optionally, the initiator, or another user, may take the role of moderator of the SE session. The moderator is in charge of distributing the SE token, introduced below.
+- Users communicate to a Central Service Server (CSS) or to all the other users.
+
+- If users communicate to a CSS, the CSS is in charge of coordinating the whole process of joint synchronous editing. The CSS takes the role of moderator of the SE session. One-to-one symmetric associations will be established between the users and the CSS. All the updates will be sent from a user to the CSS, that, in turn, will send the updates to the other users.
+- If users communicate to all the other users, two communication alternatives are possible:
+  - Use of MCS – MCS provides interactive multipoint communication functions to the users. One one-to-several association (one MCS channel) will be established between all users. All the updates will be sent from a user to all the other users.
+  - Use of the Generic Conference Control (GCC) facilities (see Recommendation T.124) – GCC provides, together with MCS, interactive multipoint conferencing functions to the users.
+
+NOTE – A third possible communication alternative could be the use of one-to-one associations without any CSS. Then  $n * (n - 1)/2$  one-to-one associations need to be established in order to allow for communication between all users. This is not specified as a solution in this Recommendation because of the high costs (e.g. a SE session with 10 users requires 45 associations with a very complicated token handling procedure). Nevertheless, some further information for this case is given in I.1.6.
+- Before manipulation starts, an Initial Document Synchronization (IDS) phase is necessary, where all users get, if not yet available, the document(s) or document fragment(s) which are to be jointly edited during the SE session.
+- There is no specific pre-established order in which the users access and manipulate the documents.
+- A SE token exists. The SE token is used to indicate which user is next in line to manipulate a document. Only the holder of the SE token can manipulate a document at any one time, while the others optionally view. The moderator controls the SE token and distributes it according to requests of users. The moderator can be the initiator, a pre-defined specific user, the user holding the SE token (i. e. the moderator role may change during the complex service session), or the CSS, if any.
+- When a user manipulates a document fragment, this operation is sent to all other users.
+- Before the SE session terminates, a Final Document Synchronization (FDS) phase is necessary, where the final version of the master copy of the document(s) is validated.
+
+### 5.2.2 Service construction rules
+
+Depending on the association type, two variants of the SE complex service are considered:
+
+- several one-to-one associations, i.e. SE with CSS;
+- one one-to-several association, i.e. SE without CSS.
+
+The two variants are illustrated in Figures 1 and 2 respectively. Let  $n$  be the number of users participating in a SE session,  $n > 1$ .
+
+Figure 1 gives an overview of the SE complex service using a CSS.
+
+In this case, the SE complex service consists of the remote editing of one or more documents by several users in an interactive and synchronous manner, where  $n - 1$  users communicate with an intermediate CSS, located at user 1.
+
+One-to-one associations are established between the  $n - 1$  users and the CSS. The CSS receives the manipulation operations and sends up-dates to the rest of the users. The CSS has the moderator role, meaning that it is responsible for assigning the SE token during the SE session.
+
+Figure 2 gives an overview of the SE complex service without CSS.
+
+In this case, the SE complex service consists of the remote editing of one or more documents by several users in an interactive and synchronous manner, without any intermediate CSS, so all users intercommunicate between themselves.
+
+![Diagram illustrating Joint Synchronous Editing (SE) with Central Service Server (CSS). The diagram shows multiple users (User 1/CSS, User 2, User 3, ..., User n) each with a client and a server. User 1/CSS is the Central Service Server. A legend indicates: a black dot represents the SE token; a lightning bolt arrow represents document manipulation (storing, retrieval); a cylinder represents the master copy of the document; and a smaller cylinder represents an optional local copy of the document. The diagram shows the SE token being passed between users and the master copy residing on the CSS server.](33ed1f9b27c7c21c797aa928b0f06851_img.jpg)
+
+● SE token
+
+⚡ Document manipulation  
+[, storing, retrieval]
+
+🗄 Master copy of the document
+
+🗄 Optional local copy of the document
+
+T0827770-97/d01
+
+Diagram illustrating Joint Synchronous Editing (SE) with Central Service Server (CSS). The diagram shows multiple users (User 1/CSS, User 2, User 3, ..., User n) each with a client and a server. User 1/CSS is the Central Service Server. A legend indicates: a black dot represents the SE token; a lightning bolt arrow represents document manipulation (storing, retrieval); a cylinder represents the master copy of the document; and a smaller cylinder represents an optional local copy of the document. The diagram shows the SE token being passed between users and the master copy residing on the CSS server.
+
+**Figure 1/T.192 – Joint Synchronous Editing (SE) with Central Service Server (CSS),  
+when CSS has the master copy of the document**
+
+One one-to-several association (MCS channel) is established between all users. No CSS exists. The role of moderator, i.e. the user responsible for assigning the SE token during the SE session, needs to be agreed.
+
+The SE complex service is based on the following basic services:
+
+- manipulation;
+- token-interchange;
+- retrieval (optional);
+- storing (optional).
+
+The manipulation basic service is used to manipulate the document remotely and to send up-dates to other users. The purpose of the SE token is to know which user is in turn to access and manipulate a document. The token-interchange basic service is used to interchange the SE token. The retrieval basic service may be used for the IDS phase. The storing basic service may be used for the FDS phase.
+
+## 5.3 Joint document Presentation/Viewing (PV)
+
+The PV complex services category consists of the remote presentation or joint viewing of a document, where a user (the presenter) presents the content of a document to other users (the viewers).
+
+![Diagram illustrating Joint Synchronous Editing (SE) without a Central Service Server (CSS). The diagram shows multiple users (User 1, User 2, ..., User n) each with a local client and server. A document server is also present. An SE token (black dot) is shown. Arrows indicate document storing and manipulation. A legend defines the symbols: SE token, [Document storing], Document manipulation, Master copy of the document, and Optional local copy of the document.](fa859e4e468bfb2710a94527f2c504af_img.jpg)
+
+The diagram illustrates a distributed system for Joint Synchronous Editing (SE) without a Central Service Server (CSS). It shows multiple users (User 1, User 2, ..., User n) each consisting of a Client and a Server. A separate Document server is also present. An SE token (represented by a black dot) is shown. Arrows indicate the flow of data and control. A legend defines the symbols used:
+
+- SE token
+- [Document storing]
+- ↔ Document manipulation [, storing, retrieval]
+- Master copy of the document
+- ◐ Optional local copy of the document
+
+T0827780-97/d02
+
+Diagram illustrating Joint Synchronous Editing (SE) without a Central Service Server (CSS). The diagram shows multiple users (User 1, User 2, ..., User n) each with a local client and server. A document server is also present. An SE token (black dot) is shown. Arrows indicate document storing and manipulation. A legend defines the symbols: SE token, [Document storing], Document manipulation, Master copy of the document, and Optional local copy of the document.
+
+**Figure 2/T.192 – Joint Synchronous Editing (SE) without Central Service Server (CSS), when the master copy of the document is not on any of the user servers**
+
+The basic principles which constitute the PV complex services are:
+
+- Several pre-determined users cooperate to jointly present/view one or more pre-determined documents. Every user has a full copy of the document(s).
+- One user will initiate the PV session. This user is called the initiator.
+- Optionally, the initiator, or another user, may take the role of moderator of the PV session. The moderator is in charge of distributing the PV token, introduced below, if any.
+- The user who presents (at a given time) the content of a document is called presenter.
+- Users who do not present (at a given time) are called viewers.
+- The presenter communicates to all viewers.
+- Users may establish several one-to-one associations or one one-to-several association.
+- If one-to-one associations are used, several one-to-one associations need to be established in order to allow for communication between all users through a CSS (see 5.2.1).
+
+- MCS may be used. Then, the establishment of one one-to-several association (one MCS channel) is enough (see 5.2.1).
+- GCC may also be used (see 5.2.1).
+- Before presentation starts, an IDS phase is necessary, where all users get, if not yet available, the document(s) which are subject to the PV session.
+- When a presenter points to a document fragment, this operation is sent to all viewers.
+- A PV token may exist. Only the holder of the PV token can present a document. The moderator controls the PV token and distributes it according to requests of viewers. The moderator can be the initiator, a pre-defined specific user, the user holding the PV token (i.e. the moderator role is changing during the PV session).
+
+The PV complex services are classified according to the number of users who can present a document to the other users, the two following cases are considered:
+
+- PV1, i.e. a joint document presentation/viewing with 1 presenter;
+- PVn, i.e. a joint document presentation/viewing with n presenters.
+
+For each of these PV complex services, the following subclauses give a description and some service construction rules, that highlight the basic services on which the complex service is founded and how these basic services are combined together. Figures 3 and 4 are used for this purpose. Let n be the number of users participating in a PV session,  $n > 1$ .
+
+![Diagram illustrating Joint document Presentation/Viewing with 1 presenter (PV1). The diagram shows a Presenter (Client 1, Server 1) connected to multiple Viewers (Client 2, Server 2; Client 3, Server 3; ...; Client n, Server n). Arrows indicate pointing or multi-pointing from the Presenter to the Viewers. Servers are represented by cylinders, with the Presenter's server being the master copy and others being optional local copies.](df82d77a0d2637cbf2da9ea920a554fa_img.jpg)
+
+The diagram illustrates a Joint document Presentation/Viewing (PV1) scenario with one presenter and multiple viewers. On the left, the 'Presenter' box contains 'Client 1' and 'Server 1' (represented by a cylinder). On the right, there are three 'Viewer' boxes: 'Viewer 1' with 'Client 2' and 'Server 2', 'Viewer 2' with 'Client 3' and 'Server 3', and 'Viewer n - 1' with 'Client n' and 'Server n'. Arrows point from the Presenter to each Viewer. A legend at the bottom left explains the symbols: an arrow for 'Pointing (n = 2) or Multi-pointing (n > 2)', a cylinder for 'Master copy of the document', and a shaded cylinder for 'Optional local copy of the document'. The Presenter's server is the master copy, while the Viewers' servers are optional local copies. Ellipses (...) indicate additional viewers between Viewer 2 and Viewer n - 1. The identifier 'T0827790-97/d03' is located at the bottom right of the diagram area.
+
+Diagram illustrating Joint document Presentation/Viewing with 1 presenter (PV1). The diagram shows a Presenter (Client 1, Server 1) connected to multiple Viewers (Client 2, Server 2; Client 3, Server 3; ...; Client n, Server n). Arrows indicate pointing or multi-pointing from the Presenter to the Viewers. Servers are represented by cylinders, with the Presenter's server being the master copy and others being optional local copies.
+
+**Figure 3/T.192 – Joint document Presentation/Viewing with 1 presenter (PV1), when the master copy of the document is on the presenter's server**
+
+![Diagram illustrating Joint document Presentation/Viewing with n presenters (PVn). A Presenter (Client n, Server n) sends a PV token (black dot) to multiple Viewers (Client 1, Server 1; Client 2, Server 2; Client 3, Server 3; ...). The Presenter also sends pointing or multi-pointing signals (arrows) to the Viewers. The Master copy of the document is on Server 1, and optional local copies are on Servers 2, 3, and n.](76b0cd79baaedd942af4dc42f2e764b8_img.jpg)
+
+● PV token
+
+→ Pointing (n = 2) or Multi-pointing (n > 2)
+
+Master copy of the document
+
+Optional local copy of the document
+
+T0827800-97/d04
+
+Diagram illustrating Joint document Presentation/Viewing with n presenters (PVn). A Presenter (Client n, Server n) sends a PV token (black dot) to multiple Viewers (Client 1, Server 1; Client 2, Server 2; Client 3, Server 3; ...). The Presenter also sends pointing or multi-pointing signals (arrows) to the Viewers. The Master copy of the document is on Server 1, and optional local copies are on Servers 2, 3, and n.
+
+**Figure 4/T.192 – Joint document Presentation/Viewing with n presenters (PVn), when the master copy of the document is on one of the user servers**
+
+### 5.3.1 Joint document Presentation/Viewing with 1 presenter (PV1)
+
+#### 5.3.1.1 Description
+
+The PV1 complex service consists of the remote presentation or joint viewing of one or more documents, where one user (the presenter) presents the content and structure of a document to the other users (the viewers).
+
+No PV token is needed.
+
+#### 5.3.1.2 Service construction rules
+
+Figure 3 gives an overview of the PV1 complex service.
+
+The PV1 complex service is based on the following basic services:
+
+- pointing (if there is only one viewer) or multi-pointing (if there are more than one viewer);
+- retrieval (optional).
+
+The pointing or multi-pointing basic services are used because the presenter needs to identify document fragments to one or several viewers, respectively. The retrieval basic service may be used for the IDS phase.
+
+### 5.3.2 Joint document Presentation/Viewing with n presenters (PVn)
+
+#### 5.3.2.1 Description
+
+The PVn complex service consists of the remote presentation or joint viewing of one or more documents, where several users (the presenters) present the content of a document to the other users (the viewers).
+
+In the PVn complex service, all users are provided with the ability to present the content of a document to the other users, but at a given time only one user presents, while the others view.
+
+Most of the characteristics of the PV1 complex service are still valid. The main differences with the PV1 complex service are:
+
+- more than one user may present;
+- a PV token is needed to control who is presenting.
+
+#### 5.3.2.2 Service construction rules
+
+Figure 4 gives an overview of the PVn complex service.
+
+The PVn complex service is based on the following basic services:
+
+- pointing (if there is only one viewer) or multi-pointing (if there are more than one viewer);
+- token-interchange;
+- retrieval (optional).
+
+The pointing or multi-pointing basic services are used because the presenter needs to identify document fragments to one or several viewers, respectively. The purpose of the PV token is to know which user is next in line to present the document. The token-interchange basic service is used to interchange the PV token. The retrieval basic service may be used for the IDS phase.
+
+# 6 Document aspects concerning the SE and PV complex services
+
+In clause 7/T.190, document aspects of the basic services are specified. The ODA Recommendations and International Standard, ITU-T Rec. T.410 series | ISO/IEC 8613, are considered as the method for representing and interchanging documents.
+
+This Recommendation specifies another document aspect, i.e. the use of non-ODA documents.
+
+## 6.1 Non-ODA documents
+
+Complex services specified in this Recommendation shall be applicable to non-ODA documents.
+
+There are two cases of handling documents:
+
+- Handling of full documents: In this case, since the operations are independent from the document structure, all basic and complex services shall apply to both ODA documents and non-ODA documents.
+- Handling of document fragments: In this case, a method to identify document fragments is needed in order to apply basic and complex services to non-ODA documents.
+
+NOTE – It is outside the scope of this Recommendation to specify such an identification mechanism. The European Workshop for Open Systems (EWOS), that is planned to be replaced by the ISSS (Information Society Standardization System), a CEN division, in September 1997, is working on the definition of a Generic Abstract Interface allowing manipulation of any kind of document.
+
+In case of working on non-ODA documents, the document format shall be specified following the rules given in 8.1.5, 8.3.2 and Annex A. More information is given in I.1.3.
+
+# **7 Communication aspects concerning the SE and PV complex services**
+
+In addition to the communication modules described in clause 8/T.190, the following communication modules are needed to specify document communication complex services:
+
+- combined DTAM-DM and DTAM-TK (DTAM-DM/TK);
+- Multipoint Communication Service (MCS);
+- Generic Conference Control (GCC).
+
+## **7.1 Combined DTAM-DM and DTAM-TK (DTAM-DM/TK)**
+
+### **7.1.1 Description**
+
+The DTAM-DM communication module is described in 8.4/T.190. The DTAM-TK communication module is described in 8.5/T.190.
+
+In addition to this, a combined DTAM-DM/DTAM-TK communication module exists, that allows a symmetric communication for remote document manipulation of documents, combined with a token interchange capability in order to synchronize the communicating entities.
+
+All the features of DTAM-DM and DTAM-TK apply.
+
+### **7.1.2 Services, protocols and profiles**
+
+The DTAM-DM symmetric abstract services are contained in the DTAM-DM-SYM application service element. The DTAM-TK abstract services are contained in the DTAM-TK application service element. Both application service elements and their combined use are specified in Recommendation T.435.
+
+The combined DTAM-DM/DTAM-TK protocol is specified in Recommendation T.436. This protocol makes use of the Association Control Service Element (ACSE), the Remote Operations Service Element (ROSE) and the presentation service.
+
+The profiles AOD11, AOD12 and AOD13, as specified in 8.4.2/T.190, also apply to this communication module.
+
+The basicReadOnlyLevel is one of the manipulation levels which can be indicated in the arguments of the abstract DTAM bind operation, as specified in 8.1/T.435.
+
+### **7.1.3 Use for document communication**
+
+DTAM-DM/TK is used for the remote interactive symmetric manipulation of documents where a token is needed to synchronize communicating entities.
+
+## **7.2 Multipoint Communication Service (MCS)**
+
+### **7.2.1 Description**
+
+Multipoint Communication Service (MCS) provides a general multipoint connection-oriented data service. It collects point-to-point transport connections and combines them to form a multipoint domain. Within that domain, a large number of logical channels can provide one-to-one, one-to-many and many-to-one data delivery. Nodes within an MCS domain are hierarchically organized in a tree structure. Data delivery normally follows the most efficient path to the nodes that are to receive the data, but a mechanism is also provided to guarantee that data from multiple source nodes is received in the same sequence at all nodes. MCS acts as a resource provider to the layers above, providing channels and token resources on demand. A large number of tokens are provided for applications to use for coordinating events and processes.
+
+### **7.2.2 Services, protocols and profiles**
+
+The MCS service and protocol are specified in Recommendations T.122 and T.125, respectively.
+
+Although the MCS is located at the OSI application layer, in the case of the basic mode profile, it works directly on top of the transport layer.
+
+No profile for MCS is fully specified for the moment.
+
+NOTE – Although no profile for MCS has still been approved, work for the definition of profiles for MCS is progressing very fast in ITU-T SG 16. Furthermore, EWOS (ISSS after September 1997) has started work on the definition of a taxonomy of profiles for MCS, taking into account the requirements of this Recommendation.
+
+### **7.2.3 Use for document communication**
+
+The MCS communication module is used to provide, when needed, the multipoint communication function to other interactive document communication modules, such as DTAM-DM or DFR modules. For this reason, it is different from the others.
+
+In order to incorporate MCS into the interactive document communication modules based on one-to-one associations, those modules need some extensions.
+
+The basic idea of the extensions is to change or remove the bind and unbind operations in order to handle MCS instead of ACSE, and to use Multipoint Remote Procedure Call (M-RPC), introduced later, instead of ROSE.
+
+NOTE 1 – These extensions are not yet specified. There is a first proposal from ITU-T SG 8 for Multipoint DTAM-DM (M-DTAM-DM) (see II.2.3).
+
+M-RPC is a new application service element that consists of the current ROSE with the added capability to send the data to multiple recipients through the use of MCS. Basically, the only change is to use MCS-SEND-DATA primitives instead of P-DATA ones.
+
+NOTE 2 – The M-RPC service and protocol are not yet specified. There is a first proposal from ITU-T SG 8 (see II.2.3).
+
+## **7.3 Generic Conference Control (GCC)**
+
+### **7.3.1 Description**
+
+Generic Conference Control (GCC) provides a set of services for setting up and managing multipoint conferences. It provides access control and arbitration of capabilities. GCC facilities are used by applications to coordinate independent use of the MCS channels and tokens within the same multipoint domain. Nodes can join and leave meetings at any time and GCC facilities can be used to query a node to find a desired meeting. GCC also makes a centralized registry facility available to applications in order to identify dynamically assigned channels and tokens.
+
+### **7.3.2 Services, protocols and profiles**
+
+The GCC service and protocol are specified in Recommendation T.124.
+
+GCC defines a service on top of MCS, and is intended to be used by specific applications, such as:
+
+- still image conferencing;
+- multipoint binary file transfer;
+- other private applications.
+
+These applications using GCC may also make direct use of MCS at the same time. The GCC Recommendation details how the MCS primitives are used.
+
+No profile for GCC is fully specified for the moment.
+
+NOTE – Although no profile for GCC has still been approved, work for the definition of profiles for GCC is progressing very fast in ITU-T SG 16. Furthermore, EWOS (ISSS after September 1997) is studying the possibility to develop a taxonomy of profiles for GCC, taking into account the requirements of this Recommendation.
+
+### 7.3.3 Use for document communication
+
+The GCC communication module is used to provide, when needed, conferencing functions to other interactive document communication modules, such as DTAM-DM or DFR modules. For this reason, it is, as MCS, different from the others.
+
+In order to combine GCC with interactive document communication modules based on one-to-one associations, those modules need some extensions similar to those described in 7.2.3.
+
+# 8 Components and design rules for the SE and PV complex services
+
+This clause provides a common base for the formal definition of complex services. It provides the rules to make such a formal definition.
+
+Complex services perform operations on service objects by using communication modules. Service objects are document stores, documents, document fragments, communicating entities and communication links. Some objects are more related to document aspects, others are related to communication aspects, and others are related to implementation aspects.
+
+Services are specified in terms of attributes, which describe their features. Attributes take values from a well-defined set of attribute values.
+
+Three service attribute sets are defined:
+
+- document related service attributes;
+- communication related service attributes;
+- implementation related service attributes.
+
+For each attribute set, all attributes and their values are described. Throughout the text of this Recommendation, the names of service attributes are embedded in quotation marks, i.e. "attribute-name", and the values of service attributes are embedded in apostrophes, i.e. 'attribute-value'.
+
+If the attribute "example-attribute" takes the value 'example-value', the following notation is used:
+
+"example-attribute" equals 'example-value'.
+
+Subclause 8.4 defines the way in which the attribute values are assigned to the document, communication and implementation related attributes for the specification of complex services.
+
+Rules for the selection and restriction of the communication modules, which shall be used by the complex services, are also specified.
+
+Finally, application rules are provided, which may include further dynamic constraints on operations of the selected and restricted communication module when applying the complex services in communication applications.
+
+## 8.1 Definition of document related service attributes
+
+This subclause defines the document related service attribute set.
+
+The document related service attributes are:
+
+- "document location";
+- "document copies";
+- "document access rights";
+- "store access rights";
+
+- "document format";
+- "functionality level";
+- "document access order".
+
+Some of these document related attributes are the same as in 9.1/T.190. Other attributes are modified or new. Table 2 gives an overview.
+
+The following subclauses describe the meaning of the modified or new document related service attributes, their values and the meaning of those values.
+
+For unchanged attributes a reference to the Recommendation T.190 is given.
+
+**Table 2/T.192 – Comparison of document related attributes for basic and complex services**
+
+| Attribute                | Basic services                                                                                            | Complex services     |                                                                                                           |
+|--------------------------|-----------------------------------------------------------------------------------------------------------|----------------------|-----------------------------------------------------------------------------------------------------------|
+|                          | Values                                                                                                    | Changes to Attribute | Values                                                                                                    |
+| "document location"      | 'local'<br>'remote'                                                                                       | <b>Modified</b>      | 'local'<br>'remote'<br>'moving'<br>'duplicated'                                                           |
+| "document copies"        | 'one'<br>'several'                                                                                        | <b>Unchanged</b>     | 'one'<br>'several'                                                                                        |
+| "document access rights" | 'no-access'<br>'read-only'<br>'extended-read'<br>'add-only'<br>'delete-only'<br>'modify'<br>'full-access' | <b>Unchanged</b>     | 'no-access'<br>'read-only'<br>'extended-read'<br>'add-only'<br>'delete-only'<br>'modify'<br>'full-access' |
+| "store access rights"    | 'no-access'<br>'read-only'<br>'extended-read'<br>'add-only'<br>'delete-only'<br>'modify'<br>'full-access' | <b>Unchanged</b>     | 'no-access'<br>'read-only'<br>'extended-read'<br>'add-only'<br>'delete-only'<br>'modify'<br>'full-access' |
+| "document format"        | FOD011'<br>FOD026'<br>FOD036'                                                                             | <b>Modified</b>      | FOD011'<br>FOD026'<br>FOD036'<br>'non-ODA'                                                                |
+| "functionality level"    | T'<br>D'<br>F'<br>F-SF'<br>DS-F-SF'<br>DM-F-SF'<br>D-F-SF'                                                | <b>Modified</b>      | D'<br>F'<br>F-SF'<br>DS-F-SF'<br>DM-F-SF'<br>D-F-SF'                                                      |
+| "document access order"  | –                                                                                                         | <b>New</b>           | 'sequential'<br>'random'                                                                                  |
+
+### 8.1.1 The service attribute "document location"
+
+This service attribute determines where the information, which is subject of the communication application, is located.
+
+The service attribute "document location" may take one of the following values:
+
+- 'local';
+- 'remote';
+- 'moving';
+- 'duplicated'.
+
+The values 'local' and 'remote' are defined as in 9.1/T.190.
+
+If access to the information is changing between 'local' and 'remote', the attribute has the value 'moving'. If access to the information is possible in different locations at the same time, the attribute has the value 'duplicated'.
+
+### **8.1.2 The service attribute "document copies"**
+
+This service attribute is defined as in 9.1/T.190.
+
+### **8.1.3 The service attribute "document access rights"**
+
+This service attribute is defined as in 9.1/T.190.
+
+### **8.1.4 The service attribute "store access rights"**
+
+This service attribute is defined as in 9.1/T.190.
+
+### **8.1.5 The service attribute "document format"**
+
+This service attribute determines the structure of the document which is subject of the communication application.
+
+The service attribute "document format" may take one of the following values:
+
+- 'FOD011';
+- 'FOD026';
+- 'FOD036';
+- 'non-ODA'.
+
+The values 'FOD011', 'FOD026' and 'FOD036' are defined as in 9.1/T.190.
+
+If the document is not in ODA format, then the attribute has the value 'non-ODA'.
+
+Clause 6 gives further information about the value 'non-ODA'.
+
+### **8.1.6 The service attribute "functionality level"**
+
+A service may deal with service objects like document stores, documents or document fragments, on which operations may be performed. The service attribute "functionality level" determines a set of service objects and operations.
+
+The service attribute "functionality level" may take one of the following values:
+
+- 'D';
+- 'F';
+- 'F-SF';
+- 'DS-F-SF';
+- 'DM-F-SF';
+- 'D-F-SF'.
+
+The value 'T' has been deleted because no complex service is independent of documents, while all other values are defined as in 9.1/T.190.
+
+The operations on service objects provided by the selected communication module may be restricted by rules given in the "Application rules" subclauses of the formal definitions of document communication complex services in clauses 9, 10 and 11.
+
+### **8.1.7 The service attribute "document access order"**
+
+This service attribute determines the access order to service objects.
+
+The service attribute "document access order" may take one of the following values:
+
+- 'sequential';
+- 'random'.
+
+If access to the service objects is performed in a strictly sequential order, the attribute has the value 'sequential', otherwise it has the value 'random'.
+
+## 8.2 Definition of communication related service attributes
+
+This subclause defines the communication related service attribute set.
+
+The communication related service attributes are:
+
+- "number of communicating entities";
+- "communication type";
+- "communication module";
+- "association";
+- "synchronization";
+- "conference type".
+
+Some of these communication related attributes are the same as in 9.2/T.190. Other attributes are modified or new. Table 3 gives an overview.
+
+The following subclauses describe the meaning of the modified or new communication related service attributes, their values and the meaning of those values.
+
+For unchanged attributes a reference to Recommendation T.190 is given.
+
+**Table 3/T.192 – Comparison of communication related attributes for basic and complex services**
+
+| Attribute                          | Basic services                                                            | Complex services     |                                                                                                |
+|------------------------------------|---------------------------------------------------------------------------|----------------------|------------------------------------------------------------------------------------------------|
+|                                    | Values                                                                    | Changes to Attribute | Values                                                                                         |
+| "number of communicating entities" | 'one-to-one'<br>'one-to-several'                                          | <b>Modified</b>      | 'one-to-several'<br>'several-to-one'<br>'several-to-several'                                   |
+| "communication type"               | 'end-to-end'<br>'store-and-forward'                                       | <b>Unchanged</b>     | 'end-to-end'<br>'store-and-forward'                                                            |
+| "communication module"             | 'DFR'<br>'DTAM-BT-NM'<br>'DTAM-DM'<br>'DTAM-TK'<br>'DFR/DTAM-DM'<br>'MHS' | <b>Modified</b>      | 'DFR'<br>'DTAM-BT-NM'<br>'DTAM-DM'<br>'DTAM-DM/TK'<br>'DFR/DTAM-DM'<br>'MHS'<br>'MCS'<br>'GCC' |
+| "association"                      | –                                                                         | <b>New</b>           | 'one-to-one'<br>'one-to-several'                                                               |
+| "synchronization"                  | –                                                                         | <b>New</b>           | 'synchronous'<br>'asynchronous'                                                                |
+| "conference type"                  | –                                                                         | <b>New</b>           | 'fixed'<br>'flexible'                                                                          |
+
+### 8.2.1 The service attribute "number of communicating entities"
+
+This service attribute gives the number of communicating entities, in a communication application, on both sides of the communication links.
+
+The service attribute "number of communicating entities" may take one of the following values:
+
+- 'one-to-several';
+- 'several-to-one';
+- 'several-to-several'.
+
+The value 'one-to-one' has been deleted because no complex service contemplates the case where one communicating entity accesses only one communicating entity. The value 'one-to-several' is defined as in 9.2/T.190. The value 'several-to-one' means that several communicating entities are accessing only one communicating entity. The value 'several-to-several' means that several communicating entities are accessing more than one communicating entity.
+
+### 8.2.2 The service attribute "communication type"
+
+This service attribute is defined as in 9.2/T.190.
+
+### 8.2.3 The service attribute "communication module"
+
+This service attribute specifies the communication module which is used by the service to carry out the communication process.
+
+The service attribute "communication module" may take one of the following values, with the exceptions given below:
+
+- 'DFR';
+- 'DTAM-BT-NM';
+- 'DTAM-DM';
+- 'DTAM-DM/TK';
+- 'DFR/DTAM-DM';
+- 'MHS';
+- 'MCS';
+- 'GCC'.
+
+The value 'DTAM-TK' has been deleted because, in complex services, the DTAM-TK module is always used in combination with other modules.
+
+The values 'DFR', 'DTAM-BT-NM', 'DTAM-DM', 'DFR/DTAM-DM' and 'MHS' are defined as in 9.2/T.190.
+
+In case of "communication module" equals 'DTAM-DM/TK', the communication module DTAM-DM/TK shall be used.
+
+In case of "communication module" equals 'MCS' or 'GCC', a second value from the rest of possible values is needed.
+
+In case of "communication module" equals 'MCS', the communication module MCS shall be used in combination with a module from any other value except 'GCC'.
+
+In case of "communication module" equals 'GCC', the communication module GCC shall be used in combination with a module from any other value except 'MCS'.
+
+NOTE – Although the GCC communication module is always used in combination with the MCS module (see 7.3), this is assumed in this Specification. Then, the combination of values 'MCS' and 'GCC' is not relevant.
+
+Characteristics of the DTAM-DM/TK, MCS and GCC communication modules are summarized in clause 7.
+
+Complex services may need the use of stand-alone basic services. In this case, the communication modules used by those basic services are not included in the list of values.
+
+### 8.2.4 The service attribute "association"
+
+This service attribute specifies the kind of association to be used.
+
+The service attribute "association" may take one of the following values:
+
+- 'one-to-one';
+- 'one-to-several'.
+
+The value 'one-to-one' shall be used if a communicating entity is connected with only one other entity, otherwise the value 'one-to-several' shall be used.
+
+### 8.2.5 The service attribute "synchronization"
+
+This service attribute specifies if the complex service is synchronous or not.
+
+The service attribute "synchronization" may take one of the following values:
+
+- 'synchronous';
+- 'asynchronous'.
+
+The value 'synchronous' shall be used if user access to the document(s) is controlled (and serialized) by means of the complex service, normally using a token handling mechanism. Otherwise, i.e. if user access to the document(s) may occur in random order, the value 'asynchronous' shall be used.
+
+### **8.2.6 The service attribute "conference type"**
+
+This service attribute specifies the type of conference that the complex service will follow, in relation to the use of special conferencing capabilities, like those provided by GCC (see 7.3).
+
+The service attribute "conference type" may take one of the following values:
+
+- 'fixed';
+- 'flexible'.
+
+If special conferencing capabilities are used, then the attribute value shall equal 'flexible'. If not, the value 'fixed' shall be used.
+
+## **8.3 Definition of implementation related service attributes**
+
+This subclause defines the implementation related service attribute set.
+
+The implementation related service attributes are:
+
+- "basic services";
+- "static information".
+
+All these attributes are specific for complex services.
+
+The following subclauses describe the meaning of the attributes, their values and the meaning of those values.
+
+### **8.3.1 The service attribute "basic services"**
+
+This service attribute gives a list of the basic services used for the implementation of the complex service, if any.
+
+The service attribute "basic services" may take zero or more of the following values:
+
+- 'STR';
+- 'DST';
+- 'RTR';
+- 'SAR';
+- 'MNP';
+- 'PNT';
+- 'MPT';
+- 'TKI'.
+
+The value 'STR' shall be used when the storing basic service is needed for the implementation of the complex service; the value 'DST' shall be used when the distribution basic service is needed for the implementation of the complex service; the value 'RTR' shall be used when the retrieval basic service is needed for the implementation of the complex service; the value 'SAR' shall be used when the storing-and-retrieval basic service is needed for the implementation of the complex service; the value 'MNP' shall be used when the manipulation basic service is needed for the implementation of the complex service; the value 'PNT' shall be used when the pointing basic service is needed for the implementation of the complex service; the value 'MPT' shall be used when the multi-pointing basic service is needed for the implementation of the complex service; the value 'TKI' shall be used when the token-interchange basic service is needed for the implementation of the complex service.
+
+This is a multi-valued attribute.
+
+The basic services are specified in Recommendation T.190.
+
+### 8.3.2 The service attribute "static information"
+
+This service attribute identifies the static information that an implementation of the complex service needs. This static information is interchanged during the establishment of the complex service session.
+
+The service attribute "static information" may take zero or more of the following values:
+
+- 'user-ids';
+- 'doc-ids';
+- 'non-ODA-format';
+- 'moderator-id'.
+
+The value 'user-ids' shall be used when identification of the users is needed to perform the complex service; the value 'doc-ids' shall be used when identification of one or more documents (and identification of the sites in which their corresponding master copies are) in which to work is needed to perform the complex service; the value 'non-ODA-format' shall be used when the value of the attribute "document format" equals 'non-ODA' in order to identify the document format used; the value 'moderator-id' shall be used when identification of the user that will take the role of moderator is needed to perform the complex service. The mechanism to provide the actual identifications is specified later.
+
+This is a multi-valued attribute.
+
+## 8.4 Rules for the formal definition of complex services
+
+For the formal definition of complex services, as given in clauses 9, 10 and 11, five steps are followed:
+
+- assignment of values to the document related service attributes;
+- assignment of values to the communication related service attributes;
+- assignment of values to the implementation related service attributes;
+- selection of the communication modules;
+- specification of application rules.
+
+Rules and notation to follow these steps are given in the following subclauses.
+
+### 8.4.1 Rules and notation for the assignment of values to the document related service attributes
+
+The assignment of values to the document related service attributes is done using the notation depicted in Table 4.
+
+In the "Service attribute" column, names of document related service attributes are given.
+
+In the "Attribute value(s)" column, all possible values of all service attributes are given for reference.
+
+For each document related service attribute, tables in clauses 9, 10 and 11 (Tables 8 to 28) (formal definition of complex services) provide, in the "Attribute value(s)" column, either a unique value or a list of values. In the first case, the unique value is the one that the attribute shall take. In the second case, one and only one value shall be selected, as specified in the last column of the tables.
+
+For some complex services, attributes may be not applicable. In this case, 'N/A' is given in the "Attribute value(s)" column of the tables.
+
+In the tables shown in clauses 9, 10 and 11 (Tables 8 to 28), the "Value description" column is used to explain the choice of the values and the possible dependencies the chosen value may have on values of other service attributes.
+
+**Table 4/T.192 – Values for document related service attributes for a complex service**
+
+| Service attribute        | Attribute value(s)                                                                                        | Value description |
+|--------------------------|-----------------------------------------------------------------------------------------------------------|-------------------|
+| "document location"      | 'local'<br>'remote'<br>'moving'<br>'duplicated'                                                           |                   |
+| "document copies"        | 'one'<br>'several'                                                                                        |                   |
+| "document access rights" | 'no-access'<br>'read-only'<br>'extended-read'<br>'add-only'<br>'delete-only'<br>'modify'<br>'full-access' |                   |
+| "store access rights"    | 'no-access'<br>'read-only'<br>'extended-read'<br>'add-only'<br>'delete-only'<br>'modify'<br>'full-access' |                   |
+| "document format"        | FOD011'<br>FOD026'<br>FOD036'<br>'non-ODA'                                                                |                   |
+| "functionality level"    | 'D'<br>'F'<br>'F-SF'<br>'DS-F-SF'<br>'DM-F-SF'<br>'D-F-SF'                                                |                   |
+| "document access order"  | 'sequential'<br>'random'                                                                                  |                   |
+
+### 8.4.2 Rules and notation for the assignment of values to the communication related service attributes
+
+The assignment of values to the communication related service attributes is done using the notation depicted in Table 5.
+
+In the "Service attribute" column, names of communication related service attributes are given.
+
+In the "Attribute value(s)" column, all possible values of all service attributes are given for reference.
+
+For each communication related service attribute, tables in clauses 9, 10 and 11 (Tables 8 to 28) (formal definition of complex services) provide, in the "Attribute value(s)" column, either a unique value or a list of values. In the first case, the unique value is the one that the attribute shall take. In the second case, one and only one value shall be selected, when no exception to this rule is given, as specified in the last column of the tables.
+
+In the Tables 8 to 28 shown in clauses 9, 10 and 11, the "Value description" column is used to explain the choice of the values and the possible dependencies the chosen value may have on values of other service attributes.
+
+**Table 5/T.192 – Values for communication related service attributes for a complex service**
+
+| Service attribute                  | Attribute value(s)                                                                             | Value description |
+|------------------------------------|------------------------------------------------------------------------------------------------|-------------------|
+| "number of communicating entities" | 'one-to-several'<br>'several-to-one'<br>'several-to-several'                                   |                   |
+| "communication type"               | 'end-to-end'<br>'store-and-forward'                                                            |                   |
+| "communication module"             | 'DFR'<br>'DTAM-BT-NM'<br>'DTAM-DM'<br>'DTAM-DM/TK'<br>'DFR/DTAM-DM'<br>'MHS'<br>'MCS'<br>'GCC' |                   |
+| "association"                      | 'one-to-one'<br>'one-to-several'                                                               |                   |
+| "synchronization"                  | 'synchronous'<br>'asynchronous'                                                                |                   |
+| "conference type"                  | 'fixed'<br>'flexible'                                                                          |                   |
+
+### **8.4.3 Rules and notation for the assignment of values to the implementation related service attributes**
+
+The assignment of values to the implementation related service attributes is done using the notation depicted in Table 6.
+
+In the "Service attribute" column, names of implementation related service attributes are given.
+
+In the "Attribute value(s)" column, all possible values of all service attributes are given for reference.
+
+For each implementation related service attribute, tables in clauses 9, 10 and 11 (Tables 8 to 28) (formal definition of complex services) provide, in the "Attribute value(s)" column, either zero values or a list of values. In the first case, the attribute has no value. In the second case, all the values shall apply.
+
+In the Tables 8 to 28 shown in clauses 9, 10 and 11, the "Value description" column is used to explain the choice of the values and the possible dependencies the chosen value(s) may have on values of other service attributes.
+
+### **8.4.4 Rules and notation for the selection of the communication modules**
+
+The selection of the communication modules and their possible restrictions (e.g. profiles) is done using the notation depicted in Table 7, using the selection mechanism described hereafter.
+
+The selection mechanism consists of a sequence of the following steps, that are to be followed to select a communication module and its restrictions (e.g. profiles) from Table 7:
+
+- Step 1: Choice of one item from the "functionality level" column; this item selects a row of the table.
+- Step 2: Choice of one or two values (see 8.2.3) of the service attribute "communication module"; this choice selects one or two columns of the table.
+- Step 3: Choice of the table entry or entries at the cross point of the selected row from step 1 and the selected column or columns from step 2.
+
+- Step 4: If the table entry (entries) is (are) empty, the service cannot be performed with the chosen combination of "functionality level" and "communication module" attribute values; otherwise, the table entry (entries) contains (contain) the restrictions that shall be applied to the selected communication module. In case 'MCS' or 'GCC' are one of the selected values of the "communication module" attribute, then the corresponding table indicates that they are possible, and the text accompanying the table specifies how to combine the communication modules. Further dynamic constraints on operations of the selected and restricted communication module(s) may be specified in 8.4.5.
+
+As specified in 8.2.3, complex services may need the use of stand-alone basic services. In this case, the communication modules used by those basic services are not included in the table.
+
+**Table 6/T.192 – Values for implementation related service attributes for a complex service**
+
+| Service attribute    | Attribute value(s)                                                   | Value description |
+|----------------------|----------------------------------------------------------------------|-------------------|
+| "basic services"     | 'STR'<br>'DST'<br>'RTR'<br>'SAR'<br>'MNP'<br>'PNT'<br>'MPT'<br>'TKI' |                   |
+| "static information" | 'user-ids'<br>'doc-ids'<br>'non-ODA-format'<br>'moderator-id'        |                   |
+
+**Table 7/T.192 – Selection of communication modules for a complex service**
+
+|                       | "communication module" |              |           |              |               |       |       |       |
+|-----------------------|------------------------|--------------|-----------|--------------|---------------|-------|-------|-------|
+| "functionality level" | 'DFR'                  | 'DTAM-BT-NM' | 'DTAM-DM' | 'DTAM-DM/TK' | 'DFR/DTAM-DM' | 'MHS' | 'MCS' | 'GCC' |
+| 'D'                   |                        |              |           |              |               |       |       |       |
+| 'F'                   |                        |              |           |              |               |       |       |       |
+| 'F-SF'                |                        |              |           |              |               |       |       |       |
+| 'DS-F-SF'             |                        |              |           |              |               |       |       |       |
+| 'DM-F-SF'             |                        |              |           |              |               |       |       |       |
+| 'D-F-SF'              |                        |              |           |              |               |       |       |       |
+
+### 8.4.5 Application rules
+
+Application rules specify further dynamic constraints on operations of the selected and restricted communication module when applying a complex service in communication applications.
+
+The application rules may, in relation to the operations in the communication modules:
+
+- prohibit the performance of some operations;
+- allow some operations only under certain conditions;
+- allow some operations only with specific arguments;
+- prescribe a certain order of operations.
+
+Application rules are given as a sequence of steps, that fall into one of the following categories, that, in turn, may have sub-steps identified by sequential numbers:
+
+- Associations Establishment Initiation step (AEI);
+- Associations Establishment End step (AEE);
+- Associations Release step (AR);
+- Initial Document Synchronization step (IDS);
+- Final Document Synchronization step (FDS);
+- Selection/Management step (SM);
+- Operations step (O);
+- MCS Domain Establishment step (MDE);
+- MCS Domain Release step (MDR);
+- MCS Users Attachment step (MUA);
+- MCS Users Detachment step (MUD);
+- MCS Channel Joining step (MCJ);
+- MCS Channel Release step (MCR);
+- GCC conference Creation step (GC);
+- GCC conference Termination step (GT);
+- GCC conference Invitation step (GI);
+- GCC conference invitation End step (GE).
+
+Steps or sub-steps may be equivalent to steps of basic services. In this case, they are identified by the corresponding basic service abbreviation and step number, as specified in clause 10/T.190.
+
+# 9 Formal definition of the SE complex service
+
+This clause defines the joint Synchronous Editing (SE) complex service, introduced in 5.1, using the rules given in clause 8.
+
+## 9.1 Document related service attributes
+
+For each document related service attribute, Table 8 provides attribute value(s) and value description, following the rules and notation specified in 8.4.1.
+
+**Table 8/T.192 – Values for document related service attributes for the SE complex service**
+
+| Service attribute        | Attribute value(s)                         | Value description                                                                                    |
+|--------------------------|--------------------------------------------|------------------------------------------------------------------------------------------------------|
+| "document location"      | 'duplicated'                               | Nevertheless, a master copy of the document(s) exists (exist).                                       |
+| "document copies"        | 'several'                                  |                                                                                                      |
+| "document access rights" | 'full-access'                              |                                                                                                      |
+| "store access rights"    | N/A                                        | The document store is not manipulated (see "functionality level" attribute).                         |
+| "document format"        | FOD011'<br>FOD026'<br>FOD036'<br>'non-ODA' | This attribute shall take only one of the possible values, depending on the document format desired. |
+| "functionality level"    | F-SF'                                      |                                                                                                      |
+| "document access order"  | 'random'                                   |                                                                                                      |
+
+## 9.2 Communication related service attributes
+
+For each communication related service attribute, Table 9 provides attribute value(s) and value description, following the rules and notation specified in 8.4.2.
+
+**Table 9/T.192 – Values for communication related service attributes for the SE complex service**
+
+| Service attribute                  | Attribute value(s)                       | Value description                                                                                                                                                                                                                                                                     |
+|------------------------------------|------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| "number of communicating entities" | 'several-to-one'<br>'several-to-several' | This attribute shall take only one of the possible values, depending on the value of the "association" attribute. The value 'several-to-one' corresponds to the value 'one-to-one' of the "association" attribute, while the value 'several-to-several' corresponds to the other one. |
+| "communication type"               | 'end-to-end'                             |                                                                                                                                                                                                                                                                                       |
+| "communication module"             | DTAM-DM/TK'                              |                                                                                                                                                                                                                                                                                       |
+| "association"                      | 'one-to-one'<br>'one-to-several'         | This attribute shall take only one of the possible values, depending on the topology desired.                                                                                                                                                                                         |
+| "synchronization"                  | 'synchronous'                            |                                                                                                                                                                                                                                                                                       |
+| "conference type"                  | 'fixed'<br>'flexible'                    | This attribute shall take only one of the possible values, depending on the conferencing facilities desired.                                                                                                                                                                          |
+
+## 9.3 Implementation related service attributes
+
+For each implementation related service attribute, Table 10 provides attribute value(s) and value description, following the rules and notation specified in 8.4.3.
+
+**Table 10/T.192 – Values for implementation related service attributes for the SE complex service**
+
+| Service attribute    | Attribute value(s)                                            | Value description                                                                                                                                                                                                                                    |
+|----------------------|---------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| "basic services"     | 'STR'<br>'RTR'<br>'MNP'<br>'TKI'                              | All the basic services associated to these values are needed, in a mandatory or optional manner, for the implementation of the complex service.                                                                                                      |
+| "static information" | 'user-ids'<br>'doc-ids'<br>'non-ODA-format'<br>'moderator-id' | The value 'moderator-id' is only needed when the "association" attribute has the value 'one-to-several'. The value 'non-ODA-format' is only needed when the "document format" attribute has the value 'non-ODA'. The other values are always needed. |
+
+## 9.4 Selection of communication modules
+
+Depending on the chosen values of the attributes "functionality level", "association" and "conference type", the following communication module restrictions shall apply:
+
+- For "functionality level" equals 'F-SF', one communication module shall be possible (DTAM-DM/TK).
+- For "association" equals 'one-to-one', the communication module selected, with the restrictions specified in Table 11 (AOD13 profile), shall be used.
+
+- For "association" equals 'one-to-several' and "conference type" equals 'fixed', the use of MCS is possible. Then, the communication module selected, with the restrictions specified in Table 11, shall be combined with MCS.
+- For "association" equals 'one-to-several' and "conference type" equals 'flexible', the use of GCC is possible. Then, the communication module selected, with the restrictions specified in Table 11, shall be combined with GCC.
+
+The communication module restrictions presented in Table 11 are defined in clause 8.
+
+**Table 11/T.192 – Selection of communication modules for the SE complex service**
+
+| "functionality level" | "communication module" |              |           |              |               |       |          |          |
+|-----------------------|------------------------|--------------|-----------|--------------|---------------|-------|----------|----------|
+|                       | 'DFR'                  | 'DTAM-BT-NM' | 'DTAM-DM' | 'DTAM-DM/TK' | 'DFR/DTAM-DM' | 'MHS' | 'MCS'    | 'GCC'    |
+| 'D'                   |                        |              |           |              |               |       |          |          |
+| 'F'                   |                        |              |           |              |               |       |          |          |
+| 'F-SF'                |                        |              |           | AOD13        |               |       | Possible | Possible |
+| 'DS-F-SF'             |                        |              |           |              |               |       |          |          |
+| 'DM-F-SF'             |                        |              |           |              |               |       |          |          |
+| 'D-F-SF'              |                        |              |           |              |               |       |          |          |
+
+## 9.5 Application rules
+
+This subclause specifies the rules the SE complex service shall follow when using communication module.
+
+### 9.5.1 Application rules when using DTAM-DM/TK
+
+The SE complex service is only applicable to document fragments. DTAM-DM/TK, restricted to the AOD13 profile, shall be used.
+
+There are three possible cases depending on the values of the "association" and "conference type" attributes:
+
+- Case 1: "association" = 'one-to-one' and "conference type" = 'fixed'.
+- Case 2: "association" = 'one-to-several' and "conference type" = 'fixed'.
+- Case 3: "association" = 'one-to-several' and "conference type" = 'flexible'.
+
+#### 9.5.1.1 Case 1: "association" = 'one-to-one' and "conference type" = 'fixed'
+
+In this case, one-to-one DTAM-DM/TK associations shall be used.
+
+Before the service is requested, the following information, identified in the "static information" attribute (see 8.3.2) shall be known for later distribution:
+
+- Users identifiers: A list of the n users (U1 to Un, U1 being the initiator, moderator and holder of the central service server) that will participate in the complex service session; they are identified according to the ASN.1 definition given in Annex A.
+- Document(s) identifier(s): A list of the documents (if any), with their corresponding document sites, that will be used in the complex service session; they are identified according to the ASN.1 definition given in Annex A.
+- Non-ODA format: The format of the document(s) in case they are not in ODA; it is identified according to the ASN.1 definition given in Annex A.
+
+User U1 will manage a central service server in charge of establishing n – 1 associations with the rest of users (U2 to Un) and distributing the SE token.
+
+When the service is requested (user U1 initiates a SE session with users U2 to Un on the document(s) previously identified, located in identified document sites), a series of steps shall be followed.
+
+This sequence of steps is summarized in Table 12.
+
+**Table 12/T.192 – Summary of application rules steps for the SE complex service,  
+when using DTAM-DM/TK communication module  
+and when "association" = 'one-to-one' and "conference type" = 'fixed'**
+
+| Steps | Sub-steps | Description                                                                                                                                                            |
+|-------|-----------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| AEI   |           | Associations Establishment Initiation                                                                                                                                  |
+| IDS   |           | Optionally, Initial Document Synchronization                                                                                                                           |
+| AEE   |           | Associations Establishment End                                                                                                                                         |
+| O     |           | Manipulation of the document(s) by the Ui users and token interchange (repeated until the moderator wants to close the session, when the moderator holds the SE token) |
+| FDS   |           | Optionally, Final Document Synchronization                                                                                                                             |
+| AR    |           | Associations Release                                                                                                                                                   |
+
+A detailed description of the steps follows:
+
+- **Step AEI:** Associations establishment initiation, starting with the connection of user U1 (initiator, central service server) to the users U2 to Un (the following steps are repeated for all the users U2 to Un, identified as Ui):
+  - user U1 issues a DTAMBind operation (DTAM-DM/TK application context) to the user Ui, with the following restrictions in the following parameters of the Bind argument:
+    - a) the value of the "dtamManipulationCapabilities" parameter shall correspond to the AOD13 profile (see 7.1.2);
+    - b) the value of the "applicationRequirements" parameter shall contain the ASN.1 data structure defined in Annex A, containing:
+      - i) the identification of the complex service (CS1);
+      - ii) the information identified by the "static information" implementation related attribute.
+- **Step IDS:** Optionally, initial document synchronization:
+  - retrieval of the identified document(s) from the identified document site, by all Ui users that need it; the RTR basic service, as specified in Recommendation T.190, shall be used.
+- **Step AEE:** Associations establishment end, finishing with the connection of user U1 (central service server) to the users U2 to Un (the following steps are repeated for all the users U2 to Un, identified as Ui):
+  - the DTAM Bind results are returned.
+- **Step O:** Manipulation of the document(s) by the Ui users and token interchange (repeated until the moderator wants to close the session, when the moderator holds the SE token):
+  - optionally, the moderator starts AOD13 operations for manipulation (MNP basic service with DTAM-DM steps 2, 3 and 4) (see 10.5.4.2/T.190);
+  - the moderator gives the SE token to another user with the TK-TOKEN-GIVE primitive (TKI basic service with DTAM-TK step 2) (see 10.8.4.1/T.190);
+  - in parallel, any user may request the SE token to the moderator with the TK-TOKEN-PLEASE primitive (TKI basic service with DTAM-TK step 2) (see 10.8.4.1/T.190);
+  - the user holding the SE token issues AOD13 operations for manipulation (see above);
+  - the user holding the SE token gives it back to the moderator with the TK-TOKEN-GIVE primitive (see above).
+
+- **Step FDS:** Optionally, final document synchronization:
+  - if the master copy of the document(s) is not on any of the user servers (i.e. the master copy has not been directly manipulated during the SE session), and if the document(s) have been modified, then the moderator stores the actually updated document (the copy that was manipulated on all the user servers during the session) where it was initially retrieved in step IDS. The STR basic service, as specified in Recommendation T.190, shall be used.
+- **Step AR:** Associations release (the following steps are repeated for all the users U2 to Un, identified as Ui):
+  - user U1 (the initiator) issues a DTAMUnbind operation to the user Ui.
+
+#### 9.5.1.2 Case 2: "association" = 'one-to-several' and "conference type" = 'fixed'
+
+In this case, MCS shall be used, with the restrictions specified hereafter.
+
+NOTE – MCS profiles, under development in ITU-T SG 16 and under study in EWOS (ISSS after September 1997), may comply in the future with these restrictions.
+
+Before the service is requested, the information identified in the "static information" attribute (see 8.3.2) shall be known for later distribution. This information is described in 9.5.1.1. Furthermore, the following information, not described in 9.5.1.1, shall be known:
+
+- Moderator identifier: Identification of the user that will take the role of moderator during the complex service session; it is identified according to the ASN.1 definition given in Annex A.
+
+Furthermore, a MCU shall be available.
+
+When the service is requested [user U1 initiates a SE session with users U2 to Un on the document(s) previously identified, located in the identified document site], a series of steps shall be followed.
+
+This sequence of steps is summarized in Table 13.
+
+**Table 13/T.192 – Summary of application rules steps for the SE complex service, when using DTAM-DM/TK communication module and when "association" = 'one-to-several' and "conference type" = 'fixed'**
+
+| Steps | Sub-steps | Description                                                                                                                                    |
+|-------|-----------|------------------------------------------------------------------------------------------------------------------------------------------------|
+| MDE   |           | MCS Domain Establishment                                                                                                                       |
+|       | MDE.1     | Connection of user U1 and the MCU                                                                                                              |
+|       | MDE.2     | Connection of users U2 to Un                                                                                                                   |
+| MUA   |           | MCS Attachment of users U1 to Un                                                                                                               |
+| MCJ   |           | Joining of a specified MCS static channel by all users U1 to Un                                                                                |
+| IDS   |           | Optionally, Initial Document Synchronization                                                                                                   |
+| O     |           | Manipulation of the document(s) by the Ui users                                                                                                |
+|       | O.1       | Optionally, initial assignment of the SE token                                                                                                 |
+|       | O.2       | Manipulation operations and token interchange (repeated until the moderator wants to close the session, when the moderator holds the SE token) |
+| FDS   |           | Optionally, Final Document Synchronization                                                                                                     |
+| MCR   |           | MCS Channel Release                                                                                                                            |
+| MUD   |           | MCS Users Detachment                                                                                                                           |
+| MDR   |           | MCS Domain Release                                                                                                                             |
+
+A detailed description of the steps follows:
+
+- **Step MDE:** MCS domain establishment, this consists of the following sub-steps:
+  - **Sub-step MDE.1:** Connection of user U1 and the MCU:
+    - a) User U1 (the initiator) issues a MCS-CONNECT-PROVIDER req primitive to the MCU, with the following restrictions in the following parameters:
+      - i) the value of the "called domain selector" parameter shall be the OCTET STRING "CS1" (identification of the complex service);
+      - ii) the value of the "upward/downward flag" parameter shall be 'up';
+      - iii) the following restrictions apply to the following parameters of the "domain parameters" parameter:
+        - 1) "number of data transfer priorities" shall be 1;
+        - 2) the "user data" parameter shall contain the ASN.1 data structure defined in Annex A, containing:
+          - the identification of the complex service (CS1);
+          - the information identified by the "static information" implementation related attribute.
+    - b) At the reception of the corresponding MCS-CONNECT-PROVIDER ind primitive, the MCU shall answer with a MCS-CONNECT-PROVIDER resp primitive, with the following restrictions in the following parameters:
+      - i) the value of the "domain parameters" parameter shall be the same as that received in the corresponding indication primitive.
+    - c) The corresponding MCS-CONNECT-PROVIDER conf primitive arrives at user U1.
+  - **Sub-step MDE.2:** Connection of users U2 to Un (the following steps are repeated for all the users U2 to Un, identified as Ui):
+    - a) The MCU issues a MCS-CONNECT-PROVIDER req primitive to Ui, with the following restrictions in the following parameters:
+      - i) the value of the "upward/downward flag" parameter shall be 'down';
+      - ii) the values of the "called domain selector" and "domain parameters" parameters shall be the same as those sent in the MCS-CONNECT-PROVIDER req primitive previously issued by user U1.
+    - b) At the reception of the corresponding MCS-CONNECT-PROVIDER ind primitive, user Ui shall answer with a MCS-CONNECT-PROVIDER resp primitive, with the following restrictions in the following parameters:
+      - i) the value of the "domain parameters" parameter shall be the same as that received in the corresponding indication primitive.
+    - c) the corresponding MCS-CONNECT-PROVIDER conf primitive arrives at the MCU.
+- **Step MUA:** MCS attachment of users U1 to Un (the following steps are repeated for all the users U1 to Un, identified as Ui):
+  - user Ui issues a MCS-ATTACH-USER req primitive to the MCU, with the following restrictions in the following parameters:
+    - a) the value of the "domain selector" parameter shall be the OCTET STRING "CS1" (identification of the complex service);
+  - the corresponding MCS-ATTACH-USER conf primitive arrives at user Ui, conveying the MCS User Id for Ui.
+
+- **Step MCJ:** Joining of an specified MCS static channel by all users U1 to Un (the following steps are repeated for all the users U1 to Un, identified as Ui):
+  - user Ui issues a MCS-CHANNEL-JOIN req primitive, with the following restrictions in the following parameters:
+    - a) the value of the "channel to join" parameter shall be 1;
+    - b) the corresponding MCS-CHANNEL-JOIN conf primitive arrives at user Ui.
+- **Step IDS:** Optionally, initial document synchronization:
+  - retrieval of the identified document(s) from the identified document site, by all Ui users that need it; the RTR basic service, as specified in Recommendation T.190, shall be used.
+- **Step O:** Manipulation of the document(s) by the Ui users, this consists of the following sub-steps (all DTAM operations are transported by MCS-SEND-DATA services):
+  - **Sub-step O.1:** Optionally, initial assignment of the token; user U1 gives the SE token to the moderator (previously identified) with the TK-TOKEN-GIVE primitive (TKI basic service with DTAM-TK step 2) (see 10.8.4.1/T.190).
+  - **Sub-step O.2:** Manipulation operations and token interchange (repeated until the moderator wants to close the session, when the moderator holds the SE token):
+    - a) optionally, the moderator starts AOD13 operations for manipulation (MNP basic service with DTAM-DM steps 2, 3 and 4) (see 10.5.4.2/T.190);
+    - b) the moderator gives the SE token to another user with the TK-TOKEN-GIVE primitive (TKI basic service with DTAM-TK step 2) (see 10.8.4.1/T.190);
+    - c) in parallel, any user may request the SE token from the moderator with the TK-TOKEN-PLEASE primitive (TKI basic service with DTAM-TK step 2) (see 10.8.4.1/T.190);
+    - d) the user holding the SE token issues AOD13 operations for manipulation (see above);
+    - e) the user holding the SE token gives it back to the moderator with the TK-TOKEN-GIVE primitive (see above).
+- **Step FDS:** Optionally, final document synchronization:
+  - if the master copy of the document(s) is not on any of the user servers (i.e. the master copy has not been directly manipulated during the SE session), and if the document(s) have been modified, then the moderator stores the actually updated document (the copy that was manipulated on all the user servers during the session) where it was initially retrieved in step IDS. The STR basic service, as specified in Recommendation T.190, shall be used.
+- **Step MCR:** MCS channel release:
+  - users U1 to Un issue a MCS-CHANNEL-LEAVE req primitive, with the following restrictions in the following parameters:
+    - a) the value of the "channel" parameter shall be 1;
+  - the corresponding MCS-CHANNEL-LEAVE ind primitives arrive at all U1 to Un users.
+- **Step MUD:** MCS users detachment:
+  - users U1 to Un issue a MCS-DETACH-USER req primitive;
+  - users still attached receive the corresponding MCS-DETACH-USER ind primitive.
+- **Step MDR:** MCS domain release:
+  - users U1 to Un issue a MCS-DISCONNECT-PROVIDER req primitive;
+  - the corresponding MCS-DISCONNECT-PROVIDER ind primitives arrive at the MCU.
+
+#### 9.5.1.3 Case 3: "association" = 'one-to-several' and "conference type" = 'flexible'
+
+In this case, GCC shall be used, with the restrictions specified here.
+
+NOTE – GCC profiles, under development in ITU-T SG 16 and under consideration in EWOS (ISSS after September 1997), may comply in the future with these restrictions.
+
+Before the service is requested, the information identified in the "static information" attribute (see 8.3.2) shall be known for later distribution. This information is described in 9.5.1.2.
+
+Furthermore, a MCU shall be available.
+
+When the service is requested [user U1 initiates a SE session with users U2 to Un on the document(s) previously identified, located in the identified document site], a series of steps shall be followed.
+
+This sequence of steps is summarized in Table 14.
+
+**Table 14/T.192 – Summary of application rules steps for the SE complex service, when using DTAM-DM/TK communication module and when "association" = 'one-to-several' and "conference type" = 'flexible'**
+
+| Steps | Sub-steps | Description                                                                                                                                       |
+|-------|-----------|---------------------------------------------------------------------------------------------------------------------------------------------------|
+| GC    |           | GCC conference Creation                                                                                                                           |
+| GI    |           | GCC conference Invitation to users U2 to Un                                                                                                       |
+| IDS   |           | Optionally, Initial Document Synchronization                                                                                                      |
+| GE    |           | GCC conference invitation End                                                                                                                     |
+| O     |           | Manipulation of the document(s) by the Ui users                                                                                                   |
+|       | O.1       | Optionally, initial assignment of the SE token                                                                                                    |
+|       | O.2       | Manipulation operations and token interchange (repeated until the moderator wants to close the SE session, when the moderator holds the SE token) |
+| FDS   |           | Optionally, Final Document Synchronization                                                                                                        |
+| GT    |           | GCC conference termination                                                                                                                        |
+
+A detailed description of the steps follows:
+
+– **Step GC:** GCC conference creation:
+
+- user U1 (the initiator) issues a GCC-CONFERENCE-CREATE req primitive to the MCU, with the following restrictions in the following parameters:
+  - a) the value of the "conference name" parameter shall be the OCTET STRING "CS1" (identification of the complex service);
+  - b) the value of the "conference locked flag" parameter shall be 'TRUE';
+  - c) the value of the "conference conducted flag" parameter shall be 'FALSE';
+  - d) the value of the "termination method" parameter shall be 'manually';
+  - e) the "user data" parameter shall contain the ASN.1 data structure defined in Annex A, containing:
+    - i) the identification of the complex service (CS1);
+    - ii) the information identified by the "static information" implementation related attribute;
+- the corresponding GCC-CONFERENCE-CREATE conf primitive arrives at user U1.
+
+- **Step GI:** GCC conference invitation to users U2 to Un (the following steps are repeated for all the users U2 to Un, identified as Ui):
+  - user U1 issues a GCC-CONFERENCE-INVITE req primitive to the Ui users, with the following restrictions in the following parameters:
+    - a) the value of the "conference id" parameter shall be the same as that previously received by user U1 in the GCC-CONFERENCE-CREATE conf primitive;
+    - b) the value of the "user data" parameter shall be the same as that sent in the GCC-CONFERENCE-CREATE req primitive previously issued by user U1;
+    - c) the value of the "called address" parameter shall contain the address of user Ui;
+  - the corresponding GCC-CONFERENCE-INVITE ind primitive arrives at users Ui.
+- **Step IDS:** Optionally, initial document synchronization:
+  - retrieval of the identified document(s) from the identified document site, by all Ui users that need it; the RTR basic service, as specified in Recommendation T.190, shall be used.
+- **Step GE:** GCC conference invitation end (the following steps are repeated for all the users U2 to Un, identified as Ui):
+  - user Ui issues a GCC-CONFERENCE-INVITE resp primitive to user U1;
+  - the corresponding GCC-CONFERENCE-INVITE conf primitive arrives at user U1.
+- **Step O:** Manipulation of the document(s) by the Ui users, this consists of the following sub-steps (all DTAM operations are transported by MCS-SEND-DATA services):
+  - **Sub-step O.1:** Optionally, initial assignment of the SE token; user U1 gives the token to the moderator (previously identified) with the TK-TOKEN-GIVE primitive (TKI basic service with DTAM-TK step 2) (see 10.8.4.1/T.190).
+  - **Sub-step O.2:** Manipulation operations and token interchange (repeated until the moderator wants to close the SE session, when the moderator holds the SE token):
+    - a) optionally, the moderator starts AOD13 operations for manipulation (MNP basic service with DTAM-DM steps 2, 3 and 4) (see 10.5.4.2/T.190);
+    - b) the moderator gives the SE token to another user with the TK-TOKEN-GIVE primitive (TKI basic service with DTAM-TK step 2) (see 10.8.4.1/T.190);
+    - c) in parallel, any user may request the SE token from the moderator with the TK-TOKEN-PLEASE primitive (TKI basic service with DTAM-TK step 2) (see 10.8.4.1/T.190);
+    - d) the user holding the SE token issues AOD13 operations for manipulation (see above);
+    - e) the user holding the SE token gives it back to the moderator with the TK-TOKEN-GIVE primitive (see above).
+- **Step FDS:** Optionally, final document synchronization:
+  - If the master copy of the document(s) is not on any of the user servers (i.e. the master copy has not been directly manipulated during the SE session), and if the document(s) have been modified, then the moderator stores the actually updated document (the copy that was manipulated on all the user servers during the session) where it was initially retrieved in step IDS. The STR basic service, as specified in Recommendation T.190, shall be used.
+
+– **Step GT:** GCC conference termination:
+
+- user U1 (the initiator) issues a GCC-CONFERENCE-TERMINATE req primitive to the users U2 to Un, with the following restrictions in the following parameters:
+  - a) the value of the "conference id" parameter shall be the same as that previously received by user U1 in the GCC-CONFERENCE-CREATE conf primitive;
+- the corresponding GCC-CONFERENCE-TERMINATE ind primitives arrive at all U2 to Un users;
+- the corresponding GCC-CONFERENCE-TERMINATE conf primitive arrives at user U1.
+
+# 10 Formal definition of the PV1 complex service
+
+This clause defines the joint document presentation/viewing with one presenter (PV1) complex service, introduced in 5.3.1, using the rules given in clause 8.
+
+## 10.1 Document related service attributes
+
+For each document related service attribute, Table 15 provides attribute value(s) and value description, following the rules and notation specified in 8.4.1.
+
+**Table 15/T.192 – Values for document related service attributes for the PV1 complex service**
+
+| Service attribute        | Attribute value(s)             | Value description                                                                                    |
+|--------------------------|--------------------------------|------------------------------------------------------------------------------------------------------|
+| "document location"      | 'remote'                       |                                                                                                      |
+| "document copies"        | 'several'                      |                                                                                                      |
+| "document access rights" | 'read-only'                    |                                                                                                      |
+| "store access rights"    | N/A                            |                                                                                                      |
+| "document format"        | FOD026'<br>FOD036'<br>non-ODA' | This attribute shall take only one of the possible values, depending on the document format desired. |
+| "functionality level"    | F'                             |                                                                                                      |
+| "document access order"  | 'random'                       |                                                                                                      |
+
+## 10.2 Communication related service attributes
+
+For each communication related service attribute, Table 16 provides attribute value(s) and value description, following the rules and notation specified in 8.4.2.
+
+**Table 16/T.192 – Values for communication related service attributes for the PV1 complex service**
+
+| Service attribute                  | Attribute value(s)               | Value description                                                                             |
+|------------------------------------|----------------------------------|-----------------------------------------------------------------------------------------------|
+| "number of communicating entities" | 'one-to-several'                 |                                                                                               |
+| "communication type"               | 'end-to-end'                     |                                                                                               |
+| "communication module"             | 'DTAM-DM'                        |                                                                                               |
+| "association"                      | 'one-to-one'<br>'one-to-several' | This attribute shall take only one of the possible values, depending on the topology desired. |
+| "synchronization"                  | 'synchronous'                    |                                                                                               |
+| "conference type"                  | 'fixed'                          |                                                                                               |
+
+## 10.3 Implementation related service attributes
+
+For each implementation related service attribute, Table 17 provides attribute value(s) and value description, following the rules and notation specified in 8.4.3.
+
+**Table 17/T.192 – Values for implementation related service attributes for the PV1 complex service**
+
+| Service attribute    | Attribute value(s)                          | Value description                                                                                                                               |
+|----------------------|---------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------|
+| "basic services"     | RTR'<br>PNT'<br>MPT'                        | All the basic services associated to these values are needed, in a mandatory or optional manner, for the implementation of the complex service. |
+| "static information" | `user-ids`<br>`doc-ids`<br>`non-ODA-format` | The value `non-ODA-format` is only needed when the "document format" attribute has the value `non-ODA`. The other values are always needed.     |
+
+## 10.4 Selection of communication modules
+
+Depending on the chosen values of the attributes "functionality level", "association" and "conference type", the following communication module restrictions shall apply:
+
+- For "functionality level" equals 'F', one communication module shall be possible (DTAM-DM/TK).
+- For "association" equals 'one-to-one', the communication module selected, with the restrictions specified in Table 18 (basic read only level), shall be used.
+- For "association" equals 'one-to-several' and "conference type" equals 'fixed', the use of MCS is possible. Then, the communication module selected, with the restrictions specified in Table 18, shall be combined with MCS.
+- For "association" equals 'one-to-several' and "conference type" equals 'flexible', the use of GCC is possible. Then, the communication module selected, with the restrictions specified in Table 18, shall be combined with GCC.
+
+The communication module restrictions presented in Table 18 are defined in clause 8.
+
+**Table 18/T.192 – Selection of communication modules for the PV1 complex service**
+
+| "functionality level" | "communication module" |              |           |                       |               |       |          |          |
+|-----------------------|------------------------|--------------|-----------|-----------------------|---------------|-------|----------|----------|
+|                       | 'DFR'                  | 'DTAM-BT-NM' | 'DTAM-DM' | 'DTAM-DM/TK'          | 'DFR/DTAM-DM' | 'MHS' | 'MCS'    | 'GCC'    |
+| 'D'                   |                        |              |           |                       |               |       |          |          |
+| 'F'                   |                        |              |           | Basic Read Only Level |               |       | Possible | Possible |
+| 'F-SF'                |                        |              |           |                       |               |       |          |          |
+| 'DS-F-SF'             |                        |              |           |                       |               |       |          |          |
+| 'DM-F-SF'             |                        |              |           |                       |               |       |          |          |
+| 'D-F-SF'              |                        |              |           |                       |               |       |          |          |
+
+## 10.5 Application rules
+
+This subclause specifies the rules the PV1 complex service shall follow when using communication module.
+
+### 10.5.1 Application rules when using DTAM-DM/TK
+
+The PV1 complex service is only applicable to document fragments. DTAM-DM/TK, restricted to its Basic Read Only Level, shall be used.
+
+There are three possible cases depending on the values of the "association" and "conference type" attributes:
+
+- Case 1: "association" = 'one-to-one' and "conference type" = 'fixed'.
+- Case 2: "association" = 'one-to-several' and "conference type" = 'fixed'.
+- Case 3: "association" = 'one-to-several' and "conference type" = 'flexible'.
+
+#### 10.5.1.1 Case 1: "association" = 'one-to-one' and "conference type" = 'fixed'
+
+In this case, one-to-one DTAM-DM/TK associations shall be used.
+
+Before the service is requested, the information identified in the "static information" attribute (see 8.3.2) shall be known for later distribution. This information is described in 9.5.1.1.
+
+User U1 will manage a central service server in charge of establishing  $n - 1$  associations with the rest of users (U2 to Un).
+
+When the service is requested [user U1 initiates a PV1 session with users U2 to Un on the document(s) previously identified, located in the identified document site], a series of steps shall be followed.
+
+This sequence of steps is summarized in Table 19.
+
+**Table 19/T.192 – Summary of application rules steps for the PV1 complex service,  
+when using DTAM-DM/TK communication module  
+and when "association" = 'one-to-one' and "conference type" = 'fixed'**
+
+| Steps | Sub-steps | Description                                                                                                 |
+|-------|-----------|-------------------------------------------------------------------------------------------------------------|
+| AEI   |           | Associations Establishment Initiation                                                                       |
+| IDS   |           | Optionally, Initial Document Synchronization                                                                |
+| AEE   |           | Associations Establishment End                                                                              |
+| O     |           | Presentation of the document(s) by the user U1 (repeated until the presenter wants to close the PV session) |
+| AR    |           | Associations Release                                                                                        |
+
+A detailed description of the steps follows:
+
+- **Step AEI:** Associations establishment initiation, starting with the connection of user U1 (initiator, central service server) to the users U2 to Un (the following steps are repeated for all the users U2 to Un, identified as Ui):
+  - user U1 issues a DTAMBind operation (DTAM-DM/TK application context) to the user Ui, with the following restrictions in the following parameters of the Bind argument:
+    - a) the value of the "dtamManipulationCapabilities" parameter shall correspond to the basic read only level (see 7.1.2);
+    - b) the value of the "applicationRequirements" parameter shall contain the ASN.1 data structure defined in Annex A, containing:
+      - i) the identification of the complex service (CS2);
+      - ii) the information identified by the "static information" implementation related attribute.
+
+- **Step IDS:** Optionally, initial document synchronization:
+  - retrieval of the identified document(s) from the identified document site, by all U<sub>i</sub> users that need it; the RTR basic service, as specified in Recommendation T.190, shall be used.
+- **Step AEE:** Associations establishment end, finishing with the connection of user U<sub>1</sub> (central service server) to the users U<sub>2</sub> to U<sub>n</sub> (the following steps are repeated for all the users U<sub>2</sub> to U<sub>n</sub>, identified as U<sub>i</sub>):
+  - the DTAM Bind results are returned.
+- **Step O:** Presentation of the document(s) by the user U<sub>1</sub> (repeated until the presenter wants to close the PV session):
+  - the DM-POINT operation shall be used to point to a document fragment inside the document(s) being presented (PNT or MPT basic service with DTAM-DM steps 2, 3 and 4) (see 10.6.4.1/T.190 and 10.7.4.1/T.190).
+- **Step AR:** Associations release (the following steps are repeated for all the users U<sub>2</sub> to U<sub>n</sub>, identified as U<sub>i</sub>):
+  - user U<sub>1</sub> (the initiator) issues a DTAMUnbind operation to the user U<sub>i</sub>.
+
+#### 10.5.1.2 Case 2: "association" = 'one-to-several' and "conference type" = 'fixed'
+
+In this case, MCS shall be used, with the restrictions specified hereafter.
+
+NOTE – MCS profiles, under development in ITU-T SG 16 and under study in EWOS (ISSS after September 1997), may comply in the future with these restrictions.
+
+Before the service is requested, the information identified in the "static information" attribute (see 8.3.2) shall be known for later distribution. This information is described in 9.5.1.1.
+
+Furthermore, a MCU shall be available.
+
+When the service is requested [user U<sub>1</sub> initiates a PV1 session with users U<sub>2</sub> to U<sub>n</sub> on the document(s) previously identified, located in the identified document site], a series of steps shall be followed.
+
+This sequence of steps is summarized in Table 20.
+
+**Table 20/T.192 – Summary of application rules steps for the PV1 complex service, when using DTAM-DM/TK communication module and when "association" = 'one-to-several' and "conference type" = 'fixed'**
+
+| Steps | Sub-steps | Description                                                                                                             |
+|-------|-----------|-------------------------------------------------------------------------------------------------------------------------|
+| MDE   |           | MCS Domain Establishment                                                                                                |
+|       | MDE.1     | Connection of user U <sub>1</sub> and the MCU                                                                           |
+|       | MDE.2     | Connection of users U <sub>2</sub> to U <sub>n</sub>                                                                    |
+| MUA   |           | MCS Attachment of Users U <sub>1</sub> to U <sub>n</sub>                                                                |
+| MCJ   |           | Joining of a specified MCS static channel by all users U <sub>1</sub> to U <sub>n</sub>                                 |
+| IDS   |           | Optionally, Initial Document Synchronization                                                                            |
+| O     |           | Presentation of the document(s) by the user U <sub>1</sub> (repeated until the presenter wants to close the PV session) |
+| MCR   |           | MCS Channel Release                                                                                                     |
+| MUD   |           | MCS Users Detachment                                                                                                    |
+| MDR   |           | MCS Domain Release                                                                                                      |
+
+A detailed description of the steps follows:
+
+- **Step MDE:** MCS domain establishment, this consists of the following sub-steps:
+  - **Sub-step MDE.1:** Connection of user U1 and the MCU:
+    - a) User U1 (the initiator) issues a MCS-CONNECT-PROVIDER req primitive to the MCU, with the following restrictions in the following parameters:
+      - i) the value of the "called domain selector" parameter shall be the OCTET STRING "CS2" (identification of the complex service);
+      - ii) the value of the "upward/downward flag" parameter shall be 'up';
+      - iii) the following restrictions apply to the following parameters of the "domain parameters" parameter:
+        - 1) "number of data transfer priorities" shall be 1;
+        - 2) the "user data" parameter shall contain the ASN.1 data structure defined in Annex A, containing:
+          - the identification of the complex service (CS2);
+          - the information identified by the "static information" implementation related attribute.
+    - b) At the reception of the corresponding MCS-CONNECT-PROVIDER ind primitive, the MCU shall answer with a MCS-CONNECT-PROVIDER resp primitive, with the following restrictions in the following parameters:
+      - i) the value of the "domain parameters" parameter shall be the same as that received in the corresponding indication primitive.
+    - c) The corresponding MCS-CONNECT-PROVIDER conf primitive arrives at user U1.
+  - **Sub-step MDE.2:** Connection of users U2 to Un (the following steps are repeated for all the users U2 to Un, identified as Ui):
+    - a) The MCU issues a MCS-CONNECT-PROVIDER req primitive to Ui, with the following restrictions in the following parameters:
+      - i) the value of the "upward/downward flag" parameter shall be 'down';
+      - ii) the values of the "called domain selector" and "domain parameters" parameters shall be the same as those sent in the MCS-CONNECT-PROVIDER req primitive previously issued by user U1.
+    - b) At the reception of the corresponding MCS-CONNECT-PROVIDER ind primitive, user Ui shall answer with a MCS-CONNECT-PROVIDER resp primitive, with the following restrictions in the following parameters:
+      - i) the value of the "domain parameters" parameter shall be the same as that received in the corresponding indication primitive.
+    - c) The corresponding MCS-CONNECT-PROVIDER conf primitive arrives at the MCU.
+- **Step MUA:** MCS attachment of users U1 to Un (the following steps are repeated for all the users U1 to Un, identified as Ui):
+  - user Ui issues a MCS-ATTACH-USER req primitive to the MCU, with the following restrictions in the following parameters:
+    - a) the value of the "domain selector" parameter shall be the OCTET STRING "CS2" (identification of the complex service);
+  - the corresponding MCS-ATTACH-USER conf primitive arrives at user Ui, conveying the MCS User Id for Ui.
+- **Step MCJ:** Joining of an specified MCS static channel by all users U1 to Un (the following steps are repeated for all the users U1 to Un, identified as Ui):
+  - user Ui issues a MCS-CHANNEL-JOIN req primitive, with the following restrictions in the following parameters:
+    - a) the value of the "channel to join" parameter shall be 1;
+  - the corresponding MCS-CHANNEL-JOIN conf primitive arrives at user Ui.
+
+- **Step IDS:** Optionally, initial document synchronization:
+  - retrieval of the identified document(s) from the identified document site, by all U<sub>i</sub> users that need it; the RTR basic service, as specified in Recommendation T.190, shall be used.
+- **Step O:** Presentation of the document(s) by the user U<sub>1</sub> (repeated until the presenter wants to close the PV session):
+  - the DM-POINT operation (this DTAM operation is transported by MCS-SEND-DATA services) shall be used to point to a document fragment inside the document(s) being presented (PNT or MPT basic service with DTAM-DM steps 2, 3 and 4) (see 10.6.4.1/T.190 and 10.7.4.1/T.190).
+- **Step MCR:** MCS channel release:
+  - users U<sub>1</sub> to U<sub>n</sub> issue a MCS-CHANNEL-LEAVE req primitive, with the following restrictions in the following parameters:
+    - a) the value of the "channel" parameter shall be 1;
+  - the corresponding MCS-CHANNEL-LEAVE ind primitives arrive at all U<sub>1</sub> to U<sub>n</sub> users.
+- **Step MUD:** MCS users detachment:
+  - users U<sub>1</sub> to U<sub>n</sub> issue a MCS-DETACH-USER req primitive;
+  - users still attached receive the corresponding MCS-DETACH-USER ind primitive.
+- **Step MDR:** MCS domain release:
+  - users U<sub>1</sub> to U<sub>n</sub> issue a MCS-DISCONNECT-PROVIDER req primitive;
+  - the corresponding MCS-DISCONNECT-PROVIDER ind primitives arrive at the MCU.
+
+#### 10.5.1.3 Case 3: "association" = 'one-to-several' and "conference type" = 'flexible'
+
+In this case, GCC shall be used, with the restrictions specified hereafter.
+
+NOTE – GCC profiles, under development in ITU-T SG 16 and under consideration in EWOS (ISSS after September 1997), may comply in the future with these restrictions.
+
+Before the service is requested, the information identified in the "static information" attribute (see 8.3.2) shall be known for later distribution. This information is described in 9.5.1.1.
+
+Furthermore, a MCU shall be available.
+
+When the service is requested [user U<sub>1</sub> initiates a PV1 session with users U<sub>2</sub> to U<sub>n</sub> on the document(s) previously identified, located in the identified document site], a series of steps shall be followed.
+
+This sequence of steps is summarized in Table 21.
+
+**Table 21/T.192 – Summary of application rules steps for the PV1 complex service, when using DTAM-DM/TK communication module and when "association" = 'one-to-several' and "conference type" = 'flexible'**
+
+| Steps | Sub-steps | Description                                                                                                             |
+|-------|-----------|-------------------------------------------------------------------------------------------------------------------------|
+| GC    |           | GCC conference Creation                                                                                                 |
+| GI    |           | GCC conference Invitation to users U <sub>2</sub> to U <sub>n</sub>                                                     |
+| IDS   |           | Optionally, Initial Document Synchronization                                                                            |
+| GE    |           | GCC conference Invitation End                                                                                           |
+| O     |           | Presentation of the document(s) by the user U <sub>1</sub> (repeated until the presenter wants to close the PV session) |
+| GT    |           | GCC conference Termination                                                                                              |
+
+A detailed description of the steps follows:
+
+- **Step GC:** GCC conference creation:
+  - user U1 (the initiator) issues a GCC-CONFERENCE-CREATE req primitive to the MCU, with the following restrictions in the following parameters:
+    - a) the value of the "conference name" parameter shall be the OCTET STRING "CS2" (identification of the complex service);
+    - b) the value of the "conference locked flag" parameter shall be 'TRUE';
+    - c) the value of the "conference conducted flag" parameter shall be 'FALSE';
+    - d) the value of the "termination method" parameter shall be 'manually';
+    - e) the "user data" parameter shall contain the ASN.1 data structure defined in Annex A, containing:
+      - i) the identification of the Complex Service (CS2);
+      - ii) the information identified by the "static information" implementation related attribute;
+    - f) the corresponding GCC-CONFERENCE-CREATE conf primitive arrives at user U1.
+- **Step GI:** GCC conference invitation to users U2 to Un (the following steps are repeated for all the users U2 to Un, identified as Ui):
+  - user U1 issues a GCC-CONFERENCE-INVITE req primitive to the Ui users, with the following restrictions in the following parameters:
+    - a) the value of the "conference id" parameter shall be the same as that previously received by user U1 in the GCC-CONFERENCE-CREATE conf primitive;
+    - b) the value of the "user data" parameter shall be the same as that sent in the GCC-CONFERENCE-CREATE req primitive previously issued by user U1;
+    - c) the value of the "called address" parameter shall contain the address of user Ui;
+  - the corresponding GCC-CONFERENCE-INVITE ind primitive arrives at users Ui.
+- **Step IDS:** Optionally, initial document synchronization:
+  - retrieval of the identified document(s) from the identified document site, by all Ui users that need it; the RTR basic service, as specified in Recommendation T.190, shall be used.
+- **Step GE:** GCC conference invitation end (the following steps are repeated for all the users U2 to Un, identified as Ui):
+  - user Ui issues a GCC-CONFERENCE-INVITE resp primitive to user U1;
+  - the corresponding GCC-CONFERENCE-INVITE conf primitive arrives at user U1.
+- **Step O:** Presentation of the document(s) by the user U1 (repeated until the presenter wants to close the PV session):
+  - the DM-POINT operation (this DTAM operation is transported by MCS-SEND-DATA services) shall be used to point to a document fragment inside the document(s) being presented (PNT or MPT basic service with DTAM-DM steps 2, 3 and 4) (see 10.6.4.1/T.190 and 10.7.4.1/T.190).
+- **Step GT:** GCC conference termination:
+  - user U1 (the initiator) issues a GCC-CONFERENCE-TERMINATE req primitive to the users U2 to Un, with the following restrictions in the following parameters:
+    - a) the value of the "conference id" parameter shall be the same as that previously received by user U1 in the GCC-CONFERENCE-CREATE conf primitive;
+
+- the corresponding GCC-CONFERENCE-TERMINATE ind primitives arrive at all U2 to Un users;
+- the corresponding GCC-CONFERENCE-TERMINATE conf primitive arrives at user U1.
+
+# 11 Formal definition of the PVn complex service
+
+This clause defines the joint document Presentation/Viewing with n presenters (PVn) complex service, introduced in 5.3.2, using the rules given in clause 8.
+
+## 11.1 Document related service attributes
+
+For each document related service attribute, Table 22 provides attribute value(s) and value description, following the rules and notation specified in 8.4.1.
+
+**Table 22/T.192 – Values for document related service attributes for the PVn complex service**
+
+| Service attribute        | Attribute value(s)              | Value description                                                                                    |
+|--------------------------|---------------------------------|------------------------------------------------------------------------------------------------------|
+| "document location"      | 'duplicated'                    |                                                                                                      |
+| "document copies"        | 'several'                       |                                                                                                      |
+| "document access rights" | 'read-only'                     |                                                                                                      |
+| "store access rights"    | N/A                             |                                                                                                      |
+| "document format"        | FOD026'<br>FOD036'<br>'non-ODA' | This attribute shall take only one of the possible values, depending on the document format desired. |
+| "functionality level"    | F'                              |                                                                                                      |
+| "document access order"  | 'random'                        |                                                                                                      |
+
+## 11.2 Communication related service attributes
+
+For each communication related service attribute, Table 23 provides attribute value(s) and value description, following the rules and notation specified in 8.4.2.
+
+**Table 23/T.192 – Values for communication related service attributes for the PVn complex service**
+
+| Service attribute                  | Attribute value(s)               | Value description                                                                             |
+|------------------------------------|----------------------------------|-----------------------------------------------------------------------------------------------|
+| "number of communicating entities" | 'several-to-several'             |                                                                                               |
+| "communication type"               | 'end-to-end'                     |                                                                                               |
+| "communication module"             | 'DTAM-DM/TK'                     |                                                                                               |
+| "association"                      | 'one-to-one'<br>'one-to-several' | This attribute shall take only one of the possible values, depending on the topology desired. |
+| "synchronization"                  | 'synchronous'                    |                                                                                               |
+| "conference type"                  | 'fixed'                          |                                                                                               |
+
+## 11.3 Implementation related service attributes
+
+For each implementation related service attribute, Table 24 provides attribute value(s) and value description, following the rules and notation specified in 8.4.3.
+
+**Table 24/T.192 – Values for implementation related service attributes for the PVn complex service**
+
+| Service attribute    | Attribute value(s)                                            | Value description                                                                                                                                                                                                                                    |
+|----------------------|---------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| "basic services"     | RTR'<br>PNT'<br>MPT'<br>TKI'                                  | All the basic services associated to these values are needed, in a mandatory or optional manner, for the implementation of the complex service.                                                                                                      |
+| "static information" | `user-ids'<br>`doc-ids'<br>`non-ODA-format'<br>`moderator-id' | The value `moderator-id` is only needed when the "association" attribute has the value `one-to-several`. The value `non-ODA-format` is only needed when the "document format" attribute has the value `non-ODA`. The other values are always needed. |
+
+## 11.4 Selection of communication modules
+
+Depending on the chosen values of the attributes "functionality level", "association" and "conference type", the following communication module restrictions shall apply:
+
+- For "functionality level" equals 'F', one communication module shall be possible (DTAM-DM/TK).
+- For "association" equals 'one-to-one', the communication module selected, with the restrictions specified in Table 25 (basic read only level), shall be used.
+- For "association" equals 'one-to-several' and "conference type" equals 'fixed', the use of MCS is possible. Then, the communication module selected, with the restrictions specified in Table 25, shall be combined with MCS.
+- For "association" equals 'one-to-several' and "conference type" equals 'flexible', the use of GCC is possible. Then, the communication module selected, with the restrictions specified in Table 25, shall be combined with GCC.
+
+The communication module restrictions presented in Table 25 are defined in clause 8.
+
+**Table 25/T.192 – Selection of communication modules for the PVn complex service**
+
+| "functionality level" | "communication module" |              |           |                       |               |       |          |          |
+|-----------------------|------------------------|--------------|-----------|-----------------------|---------------|-------|----------|----------|
+|                       | 'DFR'                  | 'DTAM-BT-NM' | 'DTAM-DM' | 'DTAM-DM/TK'          | 'DFR/DTAM-DM' | 'MHS' | 'MCS'    | 'GCC'    |
+| 'D'                   |                        |              |           |                       |               |       |          |          |
+| 'F'                   |                        |              |           | Basic Read Only Level |               |       | Possible | Possible |
+| 'F-SF'                |                        |              |           |                       |               |       |          |          |
+| 'DS-F-SF'             |                        |              |           |                       |               |       |          |          |
+| 'DM-F-SF'             |                        |              |           |                       |               |       |          |          |
+| 'D-F-SF'              |                        |              |           |                       |               |       |          |          |
+
+## 11.5 Application rules
+
+This subclause specifies the rules the PVn complex service shall follow when using communication module.
+
+### 11.5.1 Application rules when using DTAM-DM/TK
+
+The PVn complex service is only applicable to document fragments. DTAM-DM/TK, restricted to the AOD13 profile, shall be used.
+
+There are three possible cases depending on the values of the "association" and "conference type" attributes:
+
+- Case 1: "association" = 'one-to-one' and "conference type" = 'fixed'.
+- Case 2: "association" = 'one-to-several' and "conference type" = 'fixed'.
+- Case 3: "association" = 'one-to-several' and "conference type" = 'flexible'.
+
+#### 11.5.1.1 Case 1: "association" = 'one-to-one' and "conference type" = 'fixed'
+
+In this case, one-to-one DTAM-DM/TK associations shall be used.
+
+Before the service is requested, the information identified in the "static information" attribute (see 8.3.2) shall be known for later distribution. This information is described in 9.5.1.1.
+
+User U1 will manage a central service server in charge of establishing  $n - 1$  associations with the rest of users (U2 to Un) and distributing the PV token.
+
+When the service is requested [user U1 initiates a PV session with users U2 to Un on the document(s) previously identified, located in the identified document site], a series of steps shall be followed.
+
+This sequence of steps is summarized in Table 26.
+
+**Table 26/T.192 – Summary of application rules steps for the PVn complex service, when using DTAM-DM/TK communication module and when "association" = 'one-to-one' and "conference type" = 'fixed'**
+
+| Steps | Sub-steps | Description                                                                                                                                                               |
+|-------|-----------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| AEI   |           | Associations Establishment Initiation                                                                                                                                     |
+| IDS   |           | Optionally, Initial Document Synchronization                                                                                                                              |
+| AEE   |           | Associations Establishment End                                                                                                                                            |
+| O     |           | Presentation of the document(s) by the $U_i$ users and token interchange (repeated until the moderator wants to close the session, when the moderator holds the PV token) |
+| AR    |           | Associations Release                                                                                                                                                      |
+
+A detailed description of the steps follows:
+
+- **Step AEI:** Associations establishment initiation, starting with the connection of user U1 (initiator, central service server) to the users U2 to Un (the following steps are repeated for all the users U2 to Un, identified as  $U_i$ ):
+  - user U1 issues a DTAMBind operation (DTAM-DM/TK application context) to the user  $U_i$ , with the following restrictions in the following parameters of the Bind argument:
+    - a) the value of the "dtamManipulationCapabilities" parameter shall correspond to the basic read only level (see 7.1.2);
+    - b) the value of the "applicationRequirements" parameter shall contain the ASN.1 data structure defined in Annex A, containing:
+      - i) the identification of the Complex Service (CS3);
+      - ii) the information identified by the "static information" implementation related attribute.
+
+- **Step IDS:** Optionally, initial document synchronization:
+  - retrieval of the identified document(s) from the identified document site, by all U<sub>i</sub> users that need it; the RTR basic service, as specified in Recommendation T.190, shall be used.
+- **Step AEE:** Associations establishment end, finishing with the connection of user U<sub>1</sub> (central service server) to the users U<sub>2</sub> to U<sub>n</sub> (the following steps are repeated for all the users U<sub>2</sub> to U<sub>n</sub>, identified as U<sub>i</sub>):
+  - the DTAM Bind results are returned.
+- **Step O:** Presentation of the document(s) by the U<sub>i</sub> users and token interchange (repeated until the moderator wants to close the session, when the moderator holds the PV token):
+  - optionally, the moderator starts issuing DM-POINT operations (PNT or MPT basic service with DTAM-DM steps 2, 3 and 4) (see 10.6.4.1/T.190 and 10.7.4.1/T.190);
+  - the moderator gives the PV token to another user with the TK-TOKEN-GIVE primitive (TKI basic service with DTAM-TK step 2) (see 10.8.4.1/T.190);
+  - in parallel, any user may request the PV token from the moderator with the TK-TOKEN-PLEASE primitive (TKI basic service with DTAM-TK step 2) (see 10.8.4.1/T.190);
+  - the user holding the PV token issues DM-POINT operations (see above);
+  - the user holding the PV token gives it back to the moderator with the TK-TOKEN-GIVE primitive (see above).
+- **Step AR:** Associations release (the following steps are repeated for all the users U<sub>2</sub> to U<sub>n</sub>, identified as U<sub>i</sub>):
+  - user U<sub>1</sub> (the initiator) issues a DTAMUnbind operation to the user U<sub>i</sub>.
+
+#### 11.5.1.2 Case 2: "association" = 'one-to-several' and "conference type" = 'fixed'
+
+In this case, MCS shall be used, with the restrictions specified hereafter.
+
+NOTE – MCS profiles, under development in ITU-T SG 16 and under study in EWOS (ISSS after September 1997), may comply in the future with these restrictions.
+
+Before the service is requested, the information identified in the "static information" attribute (see 8.3.2) shall be known for later distribution. This information is described in 9.5.1.2.
+
+Furthermore, a MCU shall be available.
+
+When the service is requested [user U<sub>1</sub> initiates a PV session with users U<sub>2</sub> to U<sub>n</sub> on the document(s) previously identified, located in the identified document site], a series of steps shall be followed.
+
+This sequence of steps is summarized in Table 27.
+
+A detailed description of the steps follows:
+
+- **Step MDE:** MCS domain establishment, this consists of the following sub-steps:
+  - **Sub-step MDE.1:** Connection of user U<sub>1</sub> and the MCU:
+    - a) User U<sub>1</sub> (the initiator) issues a MCS-CONNECT-PROVIDER req primitive to the MCU, with the following restrictions in the following parameters:
+      - i) the value of the "called domain selector" parameter shall be the OCTET STRING "CS3" (identification of the complex service);
+      - ii) the value of the "upward/downward flag" parameter shall be 'up';
+      - iii) the following restrictions apply to the following parameters of the "domain parameters" parameter:
+        - 1) "number of data transfer priorities" shall be 1;
+        - 2) the "user data" parameter shall contain the ASN.1 data structure defined in Annex A, containing:
+          - the identification of the Complex Service (CS3);
+          - the information identified by the "static information" implementation related attribute.
+
+- b) At the reception of the corresponding MCS-CONNECT-PROVIDER ind primitive, the MCU shall answer with a MCS-CONNECT-PROVIDER resp primitive, with the following restrictions in the following parameters:
+  - i) the value of the "domain parameters" parameter shall be the same as that received in the corresponding indication primitive;
+- c) the corresponding MCS-CONNECT-PROVIDER conf primitive arrives at user U1.
+
+**Table 27/T.192 – Summary of application rules steps for the PVn complex service, when using DTAM-DM/TK communication module and when "association" = 'one-to-several' and "conference type" = 'fixed'**
+
+| Steps | Sub-steps | Description                                                                                                                                    |
+|-------|-----------|------------------------------------------------------------------------------------------------------------------------------------------------|
+| MDE   |           | MCS Domain Establishment                                                                                                                       |
+|       | MDE.1     | Connection of user U1 and the MCU                                                                                                              |
+|       | MDE.2     | Connection of users U2 to Un                                                                                                                   |
+| MUA   |           | MCS attachment of users U1 to Un                                                                                                               |
+| MCJ   |           | Joining of a specified MCS static channel by all users U1 to Un                                                                                |
+| IDS   |           | Optionally, initial document synchronization                                                                                                   |
+| O     |           | Presentation of the document(s) to the Ui users                                                                                                |
+|       | O.1       | Optionally, initial assignment of the PV token                                                                                                 |
+|       | O.2       | Presentation operations and token interchange (repeated until the moderator wants to close the session, when the moderator holds the PV token) |
+| MCR   |           | MCS channel release                                                                                                                            |
+| MUD   |           | MCS users detachment                                                                                                                           |
+| MDR   |           | MCS domain release                                                                                                                             |
+
+- **Sub-step MDE.2:** Connection of users U2 to Un (the following steps are repeated for all the users U2 to Un, identified as Ui):
+  - a) The MCU issues a MCS-CONNECT-PROVIDER req primitive to Ui, with the following restrictions in the following parameters:
+    - i) the value of the "upward/downward flag" parameter shall be 'down';
+    - ii) the values of the "called domain selector" and "domain parameters" parameters shall be the same as those sent in the MCS-CONNECT-PROVIDER req primitive previously issued by user U1.
+  - b) At the reception of the corresponding MCS-CONNECT-PROVIDER ind primitive, user Ui shall answer with a MCS-CONNECT-PROVIDER resp primitive, with the following restrictions in the following parameters:
+    - i) the value of the "domain parameters" parameter shall be the same as that received in the corresponding indication primitive.
+  - c) The corresponding MCS-CONNECT-PROVIDER conf primitive arrives at the MCU.
+- **Step MUA:** MCS attachment of users U1 to Un (the following steps are repeated for all the users U1 to Un, identified as Ui):
+  - user Ui issues a MCS-ATTACH-USER req primitive to the MCU, with the following restrictions in the following parameters:
+    - a) the value of the "domain selector" parameter shall be the OCTET STRING "CS3" (identification of the complex service);
+  - the corresponding MCS-ATTACH-USER conf primitive arrives at user Ui, conveying the MCS User Id for Ui.
+
+- **Step MCJ:** Joining of an specified MCS static channel by all users U1 to Un (the following steps are repeated for all the users U1 to Un, identified as Ui):
+  - user Ui issues a MCS-CHANNEL-JOIN req primitive, with the following restrictions in the following parameters:
+    - a) the value of the "channel to join" parameter shall be 1;
+  - the corresponding MCS-CHANNEL-JOIN conf primitive arrives at user Ui.
+- **Step IDS:** Optionally, initial document synchronization:
+  - retrieval of the identified document(s) from the identified document site, by all Ui users that need it; the RTR basic service, as specified in Recommendation T.190, shall be used.
+- **Step O:** Presentation of the document(s) to the Ui users, this consists of the following sub-steps (all DTAM operations are transported by MCS-SEND-DATA services):
+  - **Sub-step O.1:** Optionally, initial assignment of the token; user U1 gives the token to the moderator (previously identified) with the TK-TOKEN-GIVE primitive (TKI basic service with DTAM-TK step 2) (see 10.8.4.1/T.190).
+  - **Sub-step O.2:** Presentation operations and token interchange (repeated until the moderator wants to close the session, when the moderator holds the PV token):
+    - a) optionally, the moderator starts issuing DM-POINT operations (PNT or MPT basic service with DTAM-DM steps 2, 3 and 4) (see 10.6.4.1/T.190 and 10.7.4.1/T.190);
+    - b) the moderator gives the PV token to another user with the TK-TOKEN-GIVE primitive (TKI basic service with DTAM-TK step 2) (see 10.8.4.1/T.190);
+    - c) in parallel, any user may request the PV token from the moderator with the TK-TOKEN-PLEASE primitive (TKI basic service with DTAM-TK step 2) (see 10.8.4.1/T.190);
+    - d) the user holding the PV token issues DM-POINT operations (see above);
+    - e) the user holding the PV token gives it back to the moderator with the TK-TOKEN-GIVE primitive (see above).
+- **Step MCR:** MCS channel release:
+  - users U1 to Un issue a MCS-CHANNEL-LEAVE req primitive, with the following restrictions in the following parameters:
+    - a) the value of the "channel" parameter shall be 1;
+  - the corresponding MCS-CHANNEL-LEAVE ind primitives arrive at all U1 to Un users.
+- **Step MUD:** MCS users detachment:
+  - users U1 to Un issue a MCS-DETACH-USER req primitive;
+  - users still attached receive the corresponding MCS-DETACH-USER ind primitive.
+- **Step MDR:** MCS domain release:
+  - users U1 to Un issue a MCS-DISCONNECT-PROVIDER req primitive;
+  - the corresponding MCS-DISCONNECT-PROVIDER ind primitives arrive at the MCU.
+
+#### 11.5.1.3 Case 3: "association" = 'one-to-several' and "conference type" = 'flexible'
+
+In this case, GCC shall be used, with the restrictions specified hereafter.
+
+NOTE – GCC profiles, under development in ITU-T SG 16 and under consideration in EWOS (ISSS after September 1997), may comply in the future with these restrictions.
+
+Before the service is requested, the information identified in the "static information" attribute (see 8.3.2) shall be known for later distribution. This information is described in 9.5.1.2.
+
+Furthermore, a MCU shall be available.
+
+When the service is requested [user U1 initiates a PV session with users U2 to Un on the document(s) previously identified, located in the identified document site], a series of steps shall be followed.
+
+This sequence of steps is summarized in Table 28.
+
+**Table 28/T.192 – Summary of application rules steps for the PVn complex service, when using DTAM-DM/TK communication module and when "association" = 'one-to-several' and "conference type" = 'flexible'**
+
+| Steps | Sub-steps | Description                                                                                                                                    |
+|-------|-----------|------------------------------------------------------------------------------------------------------------------------------------------------|
+| GC    |           | GCC conference Creation                                                                                                                        |
+| GI    |           | GCC conference Invitation to users U2 to Un                                                                                                    |
+| IDS   |           | Optionally, Initial Document Synchronization                                                                                                   |
+| GE    |           | GCC conference invitation End                                                                                                                  |
+| O     |           | Presentation of the document(s) by the Ui users                                                                                                |
+|       | O.1       | Optionally, initial assignment of the PV token                                                                                                 |
+|       | O.2       | Presentation operations and token interchange (repeated until the moderator wants to close the session, when the moderator holds the PV token) |
+| GT    |           | GCC conference Termination                                                                                                                     |
+
+A detailed description of the steps follows:
+
+– **Step GC:** GCC conference creation:
+
+- user U1 (the initiator) issues a GCC-CONFERENCE-CREATE req primitive to the MCU, with the following restrictions in the following parameters:
+  - a) the value of the "conference name" parameter shall be the OCTET STRING "CS3" (identification of the complex service);
+  - b) the value of the "conference locked flag" parameter shall be 'TRUE';
+  - c) the value of the "conference conducted flag" parameter shall be 'FALSE';
+  - d) the value of the "termination method" parameter shall be 'manually';
+  - e) the "user data" parameter shall contain the ASN.1 data structure defined in Annex A, containing:
+    - i) the identification of the complex service (CS3);
+    - ii) the information identified by the "static information" implementation related attribute;
+- the corresponding GCC-CONFERENCE-CREATE conf primitive arrives at user U1.
+
+– **Step GI:** GCC conference invitation to users U2 to Un (the following steps are repeated for all the users U2 to Un, identified as Ui):
+
+- user U1 issues a GCC-CONFERENCE-INVITE req primitive to the Ui users, with the following restrictions in the following parameters:
+  - a) the value of the "conference id" parameter shall be the same as that previously received by user U1 in the GCC-CONFERENCE-CREATE conf primitive;
+
+- b) the value of the "user data" parameter shall be the same as that sent in the GCC-CONFERENCE-CREATE req primitive previously issued by user U1;
+  - c) the value of the "called address" parameter shall contain the address of user Ui;
+- the corresponding GCC-CONFERENCE-INVITE ind primitive arrives at users Ui.
+- **Step IDS:** Optionally, initial document synchronization:
+  - retrieval of the identified document(s) from the identified document site, by all Ui users that need it; the RTR basic service, as specified in Recommendation T.190, shall be used.
+- **Step GE:** GCC conference invitation end (the following steps are repeated for all the users U2 to Un, identified as Ui):
+  - user Ui issues a GCC-CONFERENCE-INVITE resp primitive to user U1;
+  - the corresponding GCC-CONFERENCE-INVITE conf primitive arrives at user U1.
+- **Step O:** Presentation of the document(s) to the Ui users, this consists of the following sub-steps (all DTAM operations are transported by MCS-SEND-DATA services):
+  - **Sub-step O.1:** Optionally, initial assignment of the PV token; user U1 gives the token to the moderator (previously identified) with the TK-TOKEN-GIVE primitive (TKI basic service with DTAM-TK step 2) (see 10.8.4.1/T.190).
+  - **Sub-step O.2:** Presentation operations and token interchange (repeated until the moderator wants to close the session, when the moderator holds the PV token):
+    - a) optionally, the moderator starts issuing DM-POINT operations (PNT or MPT basic service with DTAM-DM steps 2, 3 and 4) (see 10.6.4.1/T.190 and 10.7.4.1/T.190);
+    - b) the moderator gives the PV token to another user with the TK-TOKEN-GIVE primitive (TKI basic service with DTAM-TK step 2) (see 10.8.4.1/T.190);
+    - c) in parallel, any user may request the PV token to the moderator with the TK-TOKEN-PLEASE primitive (TKI basic service with DTAM-TK step 2) (see 10.8.4.1/T.190);
+    - d) the user holding the PV token issues DM-POINT operations (see above);
+    - e) the user holding the PV token gives it back to the moderator with the TK-TOKEN-GIVE primitive (see above).
+- **Step GT:** GCC conference termination:
+  - user U1 (the initiator) issues a GCC-CONFERENCE-TERMINATE req primitive to the users U2 to Un, with the following restrictions in the following parameters:
+    - a) the value of the "conference id" parameter shall be the same as that previously received by user U1 in the GCC-CONFERENCE-CREATE conf primitive;
+  - the corresponding GCC-CONFERENCE-TERMINATE ind primitives arrive at all U2 to Un users;
+  - the corresponding GCC-CONFERENCE-TERMINATE conf primitive arrives at user U1.
+
+# Annex A
+
+## ASN.1 specification
+
+This annex contains the specification of the necessary ASN.1 data structures.
+
+A module is specified containing one ASN.1 data structure for representing the information that shall be interchanged at the beginning of the complex service session. When this information is interchanged, it is specified in the application rules of every complex service specification in clauses 9, 10 and 11. The information contained in this data structure is named InitialInformation, and, apart from the Complex Service identification, it contains what is called StaticInformation, that is introduced in the description of the "static information" attribute (see 8.3.2).
+
+The ASN.1 module is the following:
+
+**MODULE Initial-Information { }**
+
+**DEFINITIONS IMPLICIT TAGS ::= BEGIN**
+
+**EXPORTS EVERYTHING;**
+
+**IMPORTS Document-Reference**  
+**FROM Document-Profile-Descriptor { 2 8 1 5 6 }**  
+*-- see ITU-T Rec. T.415 | ISO/IEC 8613-5*
+
+**DOR**  
+**FROM DOR-definition { 2 11 0 }**  
+*-- see ISO/IEC 10031-2*
+
+**DistinguishedName**  
+**FROM InformationFramework { 2 5 1 1 }**  
+*-- see CCITT Rec. X.500 serie | ISO/IEC 9594*
+
+**InitialInformation ::= SEQUENCE {**  
+**complexServiceId [0] OCTET STRING,**  
+**staticInformation [1] StaticInformation }**
+
+**StaticInformation ::= SEQUENCE {**  
+**userIds [0] UserIds,**  
+**docIds [1] DocIds,**  
+**non-ODA-format [2] Non-ODA-format,**  
+**moderatorId [3] ModeratorId }**
+
+**UserIds ::= SEQUENCE OF UserId**
+
+**UserId ::= Name**
+
+**Name ::= CHOICE {**  
+**formal [0] DistinguishedName,**  
+**informal [1] OCTET STRING }**
+
+**DocIds ::= SEQUENCE OF DocId**
+
+**DocId ::= SEQUENCE {**  
+**document [0] DocumentId,**  
+**site [1] SiteId }**
+
+**DocumentId ::= CHOICE {**  
+**oda [0] Document-Reference,**  
+**doam [1] DOR,**  
+**directory [2] DistinguishedName,**  
+**object [3] OBJECT IDENTIFIER,**  
+**informal [4] OCTET STRING }**
+
+**SiteId ::= Name**
+
+**Non-ODA-format ::= OCTET STRING**  
+*-- An alternative representation may be used in the future.*
+
+**ModeratorId ::= UserId**
+
+**END**
+
+# **Appendix I**
+
+## **Implementation guidelines**
+
+This appendix contains guidelines for implementors of the complex services defined in this Recommendation.
+
+In I.1, general aspects are considered which are valid for every complex service.
+
+Subsequent subclauses give specific guidance on how to implement the complex services of this Recommendation:
+
+- joint synchronous editing complex service SE (CS1);
+- joint presentation/viewing with 1 presenter complex service PV1 (CS2);
+- joint presentation/viewing with n presenters complex service PVn (CS3).
+
+## **I.1 General implementation guidelines**
+
+In this subclause, general topics, valid for every complex service, are considered.
+
+### **I.1.1 Quality of Service (QOS)**
+
+QOS is defined, in the context of communication applications, as the collective effect of service performance which determines the degree of satisfaction of a user of the service or communication application.
+
+QOS is defined and measured in terms of parameters related to speed, accuracy and dependability of the normal phases of the communication between communicating entities, i.e. access, information transfer, and disengagement.
+
+In the context of the services specified in this Recommendation, those kinds of QOS parameters are left to the communication modules used. Then, QOS is related to the services as far as it is related to the involved communication modules.
+
+For more details see II.1.3/T.190.
+
+### **I.1.2 Security**
+
+Security can be achieved by administrative, logical or physical means. Only logical means are considered by this Recommendation, and should be provided mainly by the communication modules.
+
+The complex service session specified in this Recommendation needs some minimum security. From a logical point of view, in the case where MCS (with or without GCC) is used, the security is based on the fact that only one MCS domain is created for the closed group of users, the security mechanisms should therefore be put on that phase of the complex service session.
+
+Additional information is contained in II.1.4/T.190.
+
+### **I.1.3 Handling documents in non-ODA formats**
+
+This Recommendation clearly indicates in clause 6 that non-ODA documents can be used in the document communication services specified. For manipulating inside documents, a location model and an abstract interface for manipulation is needed. This is already available in ODA and some proprietary formats. Although the solution of mapping to ODA is always possible, standardization efforts are being made to specify a generic abstract interface for manipulation of documents able to work on any kind of document (see II.1.1).
+
+When the documents involved in the complex service session are not in ODA format, it is necessary to know which format is used.
+
+There are two attributes related to this concept. First, the "document format" attribute, that includes the value 'non-ODA'. In the case where this value is selected, a second attribute, "static information" includes the value 'non-ODA-format', meaning that the format of the document (the non-ODA format) needs to be specified and interchanged in the initial phases of the complex service session, as specified in the application rules.
+
+In this annex, it is stated that the non-ODA format is represented as an OCTET STRING. This is clearly a simplification. However, an OCTET STRING can always be the coding of a different ASN.1 value giving a better representation. Nevertheless, codes to identify other standard and proprietary document formats defined elsewhere can be used here.
+
+The minimum classification could be to distinguish between processable and final-form documents.
+
+### **I.1.4 Complex services token distribution**
+
+Some of the specified complex services need a token that controls who can manipulate or present a document. The complex service token is distributed by the moderator or a Central Service Server (CSS), if any.
+
+When no CSS is used, the moderator is selected by the initiator, and it is indicated in one of the static information values. The criteria to assign the moderator role are out of the scope of this Recommendation.
+
+Furthermore, criteria for token distribution, that could be done by software or by human being decision, are also outside of the scope of this Recommendation.
+
+### **I.1.5 Steps coordination in MCS**
+
+When using MCS, there is a need to know when all involved users have completed every step. In particular, it would be convenient to start the MUA step when all users have finished the MDE step, to start the MCJ step when all users have completed the MUA step, to start the IDS step when all users have finished the MCJ step, and, even more important, to start the O step when all users have completed the IDS step and to know when the O step has finished.
+
+For this purpose, there are several solutions, such as use of tokens or interchange of checking messages.
+
+As a reference, a solution based on the use of MCS tokens is outlined in the following.
+
+After every user has completed the IDS step, the user shall inhibit a MCS token. The initiator will not start an O step until the initiator has checked that all the users have inhibited the token.
+
+In order for the initiator to identify which user has not inhibited the token, all users may send also a MCS-SEND-DATA primitive informing about the correspondence between their MCS user id and complex service user id.
+
+When the moderator decides to finish a complex service session, the moderator shall grab a second MCS token. The rest of users may recognize that the session has finished by checking if that token has been grabbed.
+
+### **I.1.6 Alternative implementation to the CSS**
+
+For one-to-one associations, this Recommendation specifies the need of a Central Service Server (CSS) to coordinate the associations and the token, if any.
+
+In case one-to-one associations are used without a CSS, it is necessary to establish one-to-one associations between all the pairs of users, since no user takes the role of coordinator (as the CSS did). If the number of users ( $n$ ) is big, then many associations  $[n * (n - 1)/2]$  are needed.
+
+To send up-dates or point operations when all the associations have been established is not difficult. The main problem is to handle the complex service token. All the established DTAM associations have their own DTAM token, even those not implied in a specific interchange of up-dates (when, for example, user U1 is sending up-dates to users U2 and U3, the association between user U2 and U3 is inactive, and where the token is between U2 and U3 is irrelevant, until the token is given to another user). There is no means of knowing to whom the token has been given by the moderator, unless this is explicitly informed to all the users using an external mechanism.
+
+### **I.1.7 Leaving the session**
+
+This Specification assumes that all users leave the SE or PV sessions just at their end. However, it might be sensible to leave before termination. So, implementations could choose to provide this option.
+
+There are a few cases in which simply leaving the session before it finishes should not be allowed:
+
+- The user has any exclusive tokens.
+- The user is the moderator of the service.
+- The user has some modifications of the documents that have not been reported to the rest of the users.
+- There are only two users left. In this case the service is meaningless with only one user.
+
+### **I.1.8 Handling of error situations**
+
+This Specification does not consider the case in which an error occurs. Examples of errors are:
+
+- waiting for a primitive that never arrives;
+- disconnection of the holder of the token;
+- disconnection of the moderator, etc.
+
+Implementations should take this into account by taking the appropriate measures, like including timers, forbidding specific actions, etc.
+
+In general, the error handling and recovery mechanisms provided in the used base standards should be followed. If they do not exist or are not enough, then the application should include them.
+
+## **I.2 Specific implementation hints for the SE complex service**
+
+There are three alternatives for the implementation of the joint Synchronous Editing (SE) complex service:
+
+- use of GCC;
+- use of MCS;
+- use of one-to-one associations with a Central Service Server (CSS).
+
+If GCC is available in all users, this is the recommended implementation.
+
+If GCC is not available and MCS is available, then the use of MCS is recommended.
+
+The last option is to use the CSS. Nevertheless, the use of CSS is a simple solution when complex communication modules, like MCS or GCC, are not available.
+
+## **I.3 Specific implementation hints for the PV1 complex service**
+
+There are three alternatives for the implementation of the joint Presentation/Viewing with one presenter (PV1) complex service:
+
+- use of GCC;
+- use of MCS;
+- use of one-to-one associations with a Central Service Server (CSS).
+
+If GCC is available in all users, this is the recommended implementation.
+
+If GCC is not available and MCS is available, then the use of MCS is recommended.
+
+The last option is to use the CSS. Nevertheless, the use of CSS is a simple solution when complex communication modules, like MCS or GCC, are not available.
+
+Since no token interchange is needed, and all the process is controlled by one user, the use of CSS might be the best solution for a few users.
+
+**I.4 Specific implementation hints for the PVn complex service**
+
+There are three alternatives for the implementation of the joint Presentation/Viewing with n presenters (PVn) complex service:
+
+- use of GCC;
+
+- use of MCS;
+
+- use of one-to-one associations with a Central Service Server (CSS).
+
+If GCC is available in all users, this is the recommended implementation.
+
+If GCC is not available and MCS is available, then the use of MCS is recommended.
+
+The last option is to use the CSS. Nevertheless, the use of CSS is a simple solution when complex communication modules, like MCS or GCC, are not available.
+
+**Appendix II**
+
+**Bibliography**
+
+For the purposes of this Recommendation, the following bibliography provides additional source information about document and communication architectures, so far as they are relevant to this Recommendation.
+
+**II.1 Document architectures**
+
+**II.1.1 Generic Abstract Interface**
+
+- EWOS EG SMMI 96/085 (1996): *Contribution to the topic Generic Abstract Interface for the manipulation of documents*, J. Delgado *et al.*
+
+- EWOS TA 96/091 (EWOS EG SMMI 96/098 rev.) (1996): *New work item for Generic Abstract Interface for the manipulation of documents*, J. Delgado.
+
+- EWOS EG SMMI 96/180 (1996): *New Project Proposal – Generic Abstract Interface for the Manipulation of Documents (GAI)*, J. Delgado.
+
+NOTE – At the date of producing this Recommendation, the work in EWOS on the Generic Abstract Interface for the manipulation of documents was still being developed; it is very probable therefore, that newer documents exist.
+
+**II.2 Communication architectures**
+
+**II.2.1 Multipoint Communication Service (MCS) and Generic Conference Control (GCC)**
+
+- ITU-T Recommendation T.123 (1996), *Network specific data protocol stacks for multimedia conferencing.*
+
+- ITU-T Q3/16 T.120C – 162 (1997), *Lightweight Profiles for the T.120 Architecture – T-LITE*, B. Pulito.
+
+NOTE – At the date of producing this Recommendation, the work on implementation guidelines, profiles, and new applications in the context of the ITU-T T.120 series of Recommendations was very actively being developed; it is very probable therefore, that newer documents exist.
+
+52 Recommendation T.192 (06/98)
+
+### **II.2.2 Cooperative Document Handling (CDH)**
+
+- ITU-T Recommendation T.190 (1995), *Cooperative document handling (CDH) – Framework and basic services*.
+- ITU-T Recommendation T.191 (1996), *Cooperative Document Handling (CDH) – Joint synchronous editing (Point-to-point)*.
+
+### **II.2.3 Multipoint DTAM-DM (M-DTAM-DM) and Multipoint Remote Procedure Call (M-RPC)**
+
+- D309/A, ITU-T SG8 (February 1996): *ETSI PT76 contribution: Discussion of the architecture of the joint synchronous editing service*.
+- D364/G, ITU-T SG8 (February 1996): *Collaborative Document Handling in the Multi-Point Environment*.
+
+NOTE – At the date of producing this Recommendation, the work on M-RPC and M-DTAM-DM was still being developed; it is very probable therefore, that newer documents exist.
+
+### **II.2.4 Profiles**
+
+- EWOS EG SMMI 96/143 (1996): *Proposals for profiling ITU-T T.120 Recommendations*, J. Delgado and J. J. Acebron.
+- EWOS EG SMMI 96/178 (1996): *New Project Proposal – Desktop Conferencing (DTC)*", I. Campbell-Grant.
+- EWOS EG SMMI 97/048 (1997): *Desktop Conferencing Project Status – Relation with related work*, J. Delgado.
+
+NOTE – At the date of producing this Recommendation, the work in EWOS on profiling Recommendation T.120 was still being developed; it is very probable therefore, that newer documents exist.
+
+
+
+# ITU-T RECOMMENDATIONS SERIES
+
+|                 |                                                                                                                                |
+|-----------------|--------------------------------------------------------------------------------------------------------------------------------|
+| Series A        | Organization of the work of the ITU-T                                                                                          |
+| Series B        | Means of expression: definitions, symbols, classification                                                                      |
+| Series C        | General telecommunication statistics                                                                                           |
+| Series D        | General tariff principles                                                                                                      |
+| Series E        | Overall network operation, telephone service, service operation and human factors                                              |
+| Series F        | Non-telephone telecommunication services                                                                                       |
+| Series G        | Transmission systems and media, digital systems and networks                                                                   |
+| Series H        | Audiovisual and multimedia systems                                                                                             |
+| Series I        | Integrated services digital network                                                                                            |
+| Series J        | Transmission of television, sound programme and other multimedia signals                                                       |
+| Series K        | Protection against interference                                                                                                |
+| Series L        | Construction, installation and protection of cables and other elements of outside plant                                        |
+| Series M        | TMN and network maintenance: international transmission systems, telephone circuits, telegraphy, facsimile and leased circuits |
+| Series N        | Maintenance: international sound programme and television transmission circuits                                                |
+| Series O        | Specifications of measuring equipment                                                                                          |
+| Series P        | Telephone transmission quality, telephone installations, local line networks                                                   |
+| Series Q        | Switching and signalling                                                                                                       |
+| Series R        | Telegraph transmission                                                                                                         |
+| Series S        | Telegraph services terminal equipment                                                                                          |
+| <b>Series T</b> | <b>Terminals for telematic services</b>                                                                                        |
+| Series U        | Telegraph switching                                                                                                            |
+| Series V        | Data communication over the telephone network                                                                                  |
+| Series X        | Data networks and open system communications                                                                                   |
+| Series Y        | Global information infrastructure                                                                                              |
+| Series Z        | Programming languages                                                                                                          |
\ No newline at end of file
diff --git a/marked/T/T-REC-T.22-199303-I_PDF-E/0cc86fe8fc37b0edc9581f2af9459a52_img.jpg b/marked/T/T-REC-T.22-199303-I_PDF-E/0cc86fe8fc37b0edc9581f2af9459a52_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..cfa735b682273d2b15631b0fe7c7b2b8b75f443d
--- /dev/null
+++ b/marked/T/T-REC-T.22-199303-I_PDF-E/0cc86fe8fc37b0edc9581f2af9459a52_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:0870b33c7a5c63e36969e201068ddd170af6d67c181f20e8616751382c216cf6
+size 24549
diff --git a/marked/T/T-REC-T.22-199303-I_PDF-E/0f2a1e4a7b12fe5b8749882ecd636f5c_img.jpg b/marked/T/T-REC-T.22-199303-I_PDF-E/0f2a1e4a7b12fe5b8749882ecd636f5c_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..aa90f45a7f25557dd65efa9fddd4ba5a1f35d029
--- /dev/null
+++ b/marked/T/T-REC-T.22-199303-I_PDF-E/0f2a1e4a7b12fe5b8749882ecd636f5c_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:54d7bb396f664b30e4780bd2a20bdad6988dc33521ff22c8c2449a8856b16cf3
+size 35060
diff --git a/marked/T/T-REC-T.22-199303-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/T/T-REC-T.22-199303-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..d18e09889497b9638cda9550ea92cb84487f6eec
--- /dev/null
+++ b/marked/T/T-REC-T.22-199303-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:6291a9bd1ec0a6407b25473669e591c3ffb4342d924d234c6ce322abbdb2aeb0
+size 8361
diff --git a/marked/T/T-REC-T.22-199303-I_PDF-E/5f8af0cfcf796986f40e70571bb950f5_img.jpg b/marked/T/T-REC-T.22-199303-I_PDF-E/5f8af0cfcf796986f40e70571bb950f5_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..cbcc1dc69cc480abf615c4542daeffc084a0397d
--- /dev/null
+++ b/marked/T/T-REC-T.22-199303-I_PDF-E/5f8af0cfcf796986f40e70571bb950f5_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:d590b9ee6a986cc5a2c6d8e80326cc4793b24b3ebb82f8c30cf6e8541ec340a5
+size 46353
diff --git a/marked/T/T-REC-T.22-199303-I_PDF-E/967c30813761a8952ecc5e16bf42ea45_img.jpg b/marked/T/T-REC-T.22-199303-I_PDF-E/967c30813761a8952ecc5e16bf42ea45_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..e925f63d9b60590a182da90ebd407a0b057f0ecb
--- /dev/null
+++ b/marked/T/T-REC-T.22-199303-I_PDF-E/967c30813761a8952ecc5e16bf42ea45_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:bd12cb053ca6e4c454f6a8deacd3ef66f89c130d51df22bfeeaf410eab24de63
+size 372909
diff --git a/marked/T/T-REC-T.22-199303-I_PDF-E/bb6d33498937738ff5dac8d91c9ebaad_img.jpg b/marked/T/T-REC-T.22-199303-I_PDF-E/bb6d33498937738ff5dac8d91c9ebaad_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..0a57b3faa43f0abee5f56135430b33517a9aa5c3
--- /dev/null
+++ b/marked/T/T-REC-T.22-199303-I_PDF-E/bb6d33498937738ff5dac8d91c9ebaad_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:613f25d725ed34f70631d9ddcecdcf9fb20912427d52fbf10c4f0d0986ba5c07
+size 37881
diff --git a/marked/T/T-REC-T.22-199303-I_PDF-E/raw.md b/marked/T/T-REC-T.22-199303-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..74e1fceb9c45a447e8bf5430b4221210a5cb0d78
--- /dev/null
+++ b/marked/T/T-REC-T.22-199303-I_PDF-E/raw.md
@@ -0,0 +1,332 @@
+
+
+![ITU logo: a globe with the letters ITU inside, and a lightning bolt symbol below it.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg)
+
+ITU logo: a globe with the letters ITU inside, and a lightning bolt symbol below it.
+
+INTERNATIONAL TELECOMMUNICATION UNION
+
+# ITU-T
+
+TELECOMMUNICATION  
+STANDARDIZATION SECTOR  
+OF ITU
+
+## T.22
+
+(03/93)
+
+**TERMINAL EQUIPMENT AND PROTOCOLS  
+FOR TELEMATIC SERVICES**
+
+---
+
+**STANDARDIZED TEST CHARTS FOR  
+DOCUMENT FACSIMILE TRANSMISSIONS**
+
+**ITU-T Recommendation T.22**
+
+(Previously "CCITT Recommendation")
+
+---
+
+# FOREWORD
+
+The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the International Telecommunication Union. The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis.
+
+The World Telecommunication Standardization Conference (WTSC), which meets every four years, established the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics.
+
+ITU-T Recommendation T.22 was prepared by the ITU-T Study Group VIII (1988-1993) and was approved by the WTSC (Helsinki, March 1-12, 1993).
+
+# --- NOTES
+
+1 As a consequence of a reform process within the International Telecommunication Union (ITU), the CCITT ceased to exist as of 28 February 1993. In its place, the ITU Telecommunication Standardization Sector (ITU-T) was created as of 1 March 1993. Similarly, in this reform process, the CCIR and the IFRB have been replaced by the Radiocommunication Sector.
+
+2 In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+# CONTENTS
+
+|                                                                                                                                                 | <i>Page</i> |
+|-------------------------------------------------------------------------------------------------------------------------------------------------|-------------|
+| Annex A – Description of the standardized document facsimile test charts .....                                                                  | 1           |
+| A.1    Dimensions of the test charts .....                                                                                                      | 1           |
+| A.2    Test chart No. 4 – Black-white facsimile test chart BW01 .....                                                                           | 2           |
+| Pattern descriptions.....                                                                                                                       | 2           |
+| A.2.1    Pattern 1 – ITU-T border of 4 scales (between arrowheads) with inch and millimeter markings.....                                       | 2           |
+| A.2.2    Pattern 2 – Black bar across full page width, and a scale in inches across the top and along the left side .....                       | 2           |
+| A.2.3    Pattern 3 – Four patterns of truncated fan-type multiple-line pattern with low taper rate .....                                        | 2           |
+| A.2.4    Pattern 4 – Gurley type Pestrecov star pattern with circles of 50, 100 and 200 lines per 25.4 mm .....                                 | 2           |
+| A.2.5    Pattern 5 – Alternating black and white lines .....                                                                                    | 2           |
+| A.2.6    Pattern 6 – Black-white bar patterns .....                                                                                             | 2           |
+| A.2.7    Pattern 7 – Isolated black and white lines .....                                                                                       | 2           |
+| A.2.8    Pattern 8 – NIST type resolution pattern .....                                                                                         | 2           |
+| A.2.9    Pattern 9 – Tapered isolated black and white line patterns with the line width calibrated in microns or inches .....                   | 2           |
+| A.2.10   Pattern 10 – Black-white bar pattern of 5 black plus white bars per 25.4 mm .....                                                      | 3           |
+| A.2.11   Pattern 11 – Parallel lines inclined at 5 degrees from vertical .....                                                                  | 3           |
+| A.2.12   Pattern 12 – NIST type resolution pattern .....                                                                                        | 3           |
+| A.2.13   Pattern 13 – Diagonal line for checking irregularities in vertical pitch .....                                                         | 3           |
+| A.2.14   Pattern 14 – ISO character hexagonal line patterns for readability testing .....                                                       | 3           |
+| A.2.15   Pattern 15 – Halftone dot screens of 10, 50 and 90 percent black .....                                                                 | 3           |
+| A.2.16   Pattern 16 – Line crossing pattern.....                                                                                                | 3           |
+| A.2.17   Pattern 17 – Text in English, Arabic, Chinese, Russian, Spanish and French. English text is in 12, 10, 8, 6, 4 and 2 point sizes ..... | 3           |
+| A.3    Test Chart No. 5 – Continuous tone facsimile test chart CT01 .....                                                                       | 3           |
+| Pattern descriptions.....                                                                                                                       | 3           |
+| A.3.1    Pattern 1 – A continuous (stepless) density wedge .....                                                                                | 3           |
+| A.3.2    Pattern 2 – A reverse of the continuous wedge of Pattern 1 .....                                                                       | 3           |
+| A.3.3    Pattern 3 – A 48-step density tablet .....                                                                                             | 3           |
+| A.3.4    Pattern 4 – A set of 16 horizontal gray scale strips .....                                                                             | 3           |
+| A.3.5    Pattern 5 – An architectural photo showing fine detail.....                                                                            | 5           |
+| A.3.6    Pattern 6 – Portrait .....                                                                                                             | 5           |
+
+
+
+# STANDARDIZED TEST CHARTS FOR DOCUMENT FACSIMILE TRANSMISSIONS
+
+(Helsinki, 1993)
+
+The ITU-T,
+
+*considering*
+
+(a) that a standardized test chart to check the quality of document facsimile transmissions will have great advantages. The advancing technology of document facsimile has brought forth monochrome testing requirements that cannot be adequately met with current test charts. New higher resolution needs and transmission of high quality continuous tone gray scale must be taken into consideration;
+
+(b) that conflicting test chart reproduction requirements for black-white patterns and continuous tone has led to the definition of two new test charts:
+
+- one, high contrast “facsimile test chart” for evaluating the technical quality of the page and the legibility of the text;
+- the other, “continuous tone addendum” for the evaluation of the technical quality of continuous tone information,
+
+*unanimously adopts the view*
+
+(1) that tests of document facsimile transmission quality should be carried out in the international service using the ITU-T standardized test charts;
+
+(2) that these test charts should be produced by the ITU under the supervision of the ITU-T and should be offered for sale by the ITU. There are two types of charts:
+
+- Test chart No. 4: “Facsimile test chart” intended for the general evaluation of technical quality;
+- Test chart No. 5: “Continuous tone addendum” intended to check tonal quality.
+
+The charts are described in Annex A; the specimens printed in Annex A cannot be used for measurements;
+
+(3) that the charts should be used with electronic document storage facilities, electronic document transmission facilities, and facsimile apparatus in accordance with appropriate T-Series Recommendations.
+
+# Annex A
+
+## Description of the standardized document facsimile test charts
+
+(This annex forms an integral part of this Recommendation)
+
+## A.1 Dimensions of the test charts
+
+| Test chart No. 4 | Test chart No. 5 |
+|------------------|------------------|
+| – length: 302 mm | 279 mm           |
+| – width: 222 mm  | 216 mm           |
+
+They are divided into sections numbered:
+
+- 1-17 on test chart No. 4 for resolution testing,
+- 1-6 on test chart No. 5 for tonal quality testing.
+
+A test-chart section number is also the last part of a subclause number denoting the subclause, in A.2 and A.3 below, which describe in detail the given section of the test chart.
+
+## **A.2 Test chart No. 4 – Black-white facsimile test chart BW01**
+
+This monochrome test chart has black-white patterns, text and line work printed on high gamma photographic paper for optimum sharpness and high contrast without fogging the white areas next to black markings. The overall size of the printed chart is  $222 \times 302$  mm ( $8 \frac{3}{4} \times 11 \frac{7}{8}$  inches) to allow for maximum paper size tolerances.
+
+### **Pattern descriptions**
+
+The overall size of the printed chart is  $222 \times 302$  mm. The patterns that make up the chart are defined below. Refer to the corresponding numbers on the test chart 4 pattern arrangement.
+
+#### **A.2.1 Pattern 1 – ITU-T border of 4 scales (between arrowheads) with inch and millimeter markings**
+
+The 5 and 10 mm lines are extended. The arrows near the ends (and pointing vertically downwards) are  $8 \frac{1}{2}$  inches apart and centered on the page.
+
+#### **A.2.2 Pattern 2 – Black bar across full page width, and a scale in inches across the top and along the left side**
+
+Markings start from 0 in the middle of the page with 0.1 inch scale. The vertical border at the left side of the chart is marked in inches.
+
+#### **A.2.3 Pattern 3 – Four patterns of truncated fan-type multiple-line pattern with low taper rate**
+
+The larger patterns are calibrated in black plus white lines per inch, and the smaller ones are calibrated in microns.
+
+#### **A.2.4 Pattern 4 – Gurley type Pestrecov star pattern with circles of 50, 100 and 200 lines per 25.4 mm**
+
+This pattern is better for detecting some moire phenomena than pattern 3.
+
+#### **A.2.5 Pattern 5 – Alternating black and white lines**
+
+Upper pattern is 150 lines per 25.4 mm, inclined at 3 degrees from vertical. The lower pattern is 200 lines per 25.4 mm, inclined at 2 degrees from vertical. The angle is to allow the lines to drift through a match and a mismatch with the photosensor array elements.
+
+#### **A.2.6 Pattern 6 – Black-white bar patterns**
+
+Bar Patterns of 100, 150, 200, 300, 400 and 600 lines per 25.4 mm.
+
+#### **A.2.7 Pattern 7 – Isolated black and white lines**
+
+The vertical pattern is inclined at 5 degrees from vertical.
+
+#### **A.2.8 Pattern 8 – NIST type resolution pattern**
+
+Calibrated in line pairs (black plus white) per millimeter with the smallest patterns near the center of the chart.
+
+#### **A.2.9 Pattern 9 – Tapered isolated black and white line patterns with the line width calibrated in microns or inches**
+
+#### **A.2.10 Pattern 10 – Black-white bar pattern of 5 black plus white bars per 25.4 mm**
+
+#### **A.2.11 Pattern 11 – Parallel lines inclined at 5 degrees from vertical**
+
+#### **A.2.12 Pattern 12 – NIST type resolution pattern**
+
+Calibrated in line pairs (black plus white) per millimeter with the smallest patterns near the edge of the chart.
+
+#### **A.2.13 Pattern 13 – Diagonal line for checking irregularities in vertical pitch**
+
+Received lines with errors will show breaks or steps in this line.
+
+#### **A.2.14 Pattern 14 – ISO character hexagonal line patterns for readability testing**
+
+#### **A.2.15 Pattern 15 – Halftone dot screens of 10, 50 and 90 percent black**
+
+The 65 and 120 are the number of dots per 25.4 mm measured at a 45 degree angle.
+
+#### **A.2.16 Pattern 16 – Line crossing pattern**
+
+The center to center line separation is 0.15 inches on the left end and 0.05 inches on the right end. The number of scanning line crossings of both lines multiplied by 10 is the vertical line pitch in lines per 25.4 mm.
+
+#### **A.2.17 Pattern 17 – Text in English, Arabic, Chinese, Russian, Spanish and French. English text is in 12, 10, 8, 6, 4 and 2 point sizes**
+
+### **A.3 Test Chart No. 5 – Continuous tone facsimile test chart CT01**
+
+This continuous tone test chart is printed on low gamma photographic material that preserves the complete gray scale between paper white and black for continuous tone photographs. It can be used for testing both facsimile machines with gray scale capability and those machines that are black-white only. The black-white threshold setting of the facsimile scanner can be set very accurately with this chart.
+
+### **Pattern descriptions**
+
+The overall size of the printed chart is 279 × 216 mm. The patterns that make up the chart are defined below. Refer to the corresponding numbers on the test chart 5 pattern arrangement.
+
+#### **A.3.1 Pattern 1 – A continuous (stepless) density wedge**
+
+From black on the left to white on the right.
+
+#### **A.3.2 Pattern 2 – A reverse of the continuous wedge of Pattern 1**
+
+White on the left.
+
+#### **A.3.3 Pattern 3 – A 48-step density tablet**
+
+With 3 rows of 16 density steps from white to black. Steps are designed for equal-perceptibility human observers (see Table A.1).
+
+#### **A.3.4 Pattern 4 – A set of 16 horizontal gray scale strips**
+
+From black to white (see Table A.2).
+
+TABLE A.1/T.22
+
+##### **Pattern 3 density values**
+
+|    | A    | B    | C    |
+|----|------|------|------|
+| 1  | 0.00 | 0.29 | 0.85 |
+| 2  | 0.02 | 0.33 | 0.90 |
+| 3  | 0.03 | 0.37 | 0.93 |
+| 4  | 0.04 | 0.38 | 0.97 |
+| 5  | 0.06 | 0.39 | 1.01 |
+| 6  | 0.09 | 0.43 | 1.06 |
+| 7  | 0.10 | 0.45 | 1.10 |
+| 8  | 0.12 | 0.50 | 1.16 |
+| 9  | 0.12 | 0.54 | 1.20 |
+| 10 | 0.14 | 0.56 | 1.27 |
+| 11 | 0.15 | 0.60 | 1.31 |
+| 12 | 0.17 | 0.62 | 1.33 |
+| 13 | 0.19 | 0.66 | 1.41 |
+| 14 | 0.21 | 0.68 | 1.50 |
+| 15 | 0.23 | 0.69 | 1.60 |
+| 16 | 0.24 | 0.73 | 1.71 |
+
+TABLE A.2/T.22
+
+##### **Pattern 4 density values**
+
+| Strip | Density | Strip | Density |
+|-------|---------|-------|---------|
+| 1     | 1.937   | 9     | 0.937   |
+| 2     | 1.812   | 10    | 0.812   |
+| 3     | 1.687   | 11    | 0.687   |
+| 4     | 1.562   | 12    | 0.562   |
+| 5     | 1.437   | 13    | 0.437   |
+| 6     | 1.312   | 14    | 0.313   |
+| 7     | 1.187   | 15    | 0.187   |
+| 8     | 1.062   | 16    | 0.062   |
+
+#### **A.3.5 Pattern 5 – An architectural photo showing fine detail**
+
+#### **A.3.6 Pattern 6 – Portrait**
+
+
+
+![A comprehensive Black-White Facsimile Test Chart (ITU-T Test Chart No. 4) featuring various resolution and contrast tests, including line patterns, character sets in multiple languages, and numerical scales.](967c30813761a8952ecc5e16bf42ea45_img.jpg)
+
+This test chart includes the following sections:
+
+- Resolution Tests:**
+  - Top center: A circular pattern of lines with a scale from 40 to 500.
+  - Top right: A series of horizontal lines with a scale from 100 to 500.
+  - Bottom right: A series of vertical lines with a scale from 1.4 to 2.5.
+- Character Sets:**
+  - Courier 12 pt.**: ABCDEFGHIJKLMNOPQRSTUVWXYZ, abcdefghijklmnopqrstuvwxyz, 1234567890
+  - Prestige Elite Bold**: ABCDEFGHIJKLMNOPQRSTUVWXYZ, abcdefghijklmnopqrstuvwxyz, 1234567890
+  - Italia Book**: ABCDEFGHIJKLMNOPQRSTUVWXYZ, abcdefghijklmnopqrstuvwxyz, 1234567890
+  - 13.75P**: 男女体操 (Gymnastics), 家庭用品 (Household items), 新春景色 (New Year's scenery), 普通教育 (General education)
+  - 7.875P**: 男女体操 (Gymnastics), 家庭用品 (Household items), 新春景色 (New Year's scenery), 普通教育 (General education)
+  - Groupo nº 1**: HELVETICA 8 PUNTOS, ABCDEFGHIJKLMNOPQRSTUVWXYZ, abcdefghijklmnopqrstuvwxyz, 1234567890, \$ 23 œ F [ ] ç N . £ - ± x : © • ß \_ é + = \$ / ( ) & % \*
+  - Groupe n° 1**: HELVETICA 10 POINTS, ABCDEFGHIJKLMNOPQRSTUVWXYZ, abcdefghijklmnopqrstuvwxyz, 1234567890, \$ 23 œ F [ ] ç N . £ - ± x : © • ß \_ é + = \$ / ( ) & % \*
+- Other Tests:**
+  - Left side: A series of horizontal lines with a scale from 1 to 11.
+  - Right side: A series of vertical lines with a scale from 1 to 11.
+  - Bottom center: A series of horizontal lines with a scale from 1 to 11.
+
+A comprehensive Black-White Facsimile Test Chart (ITU-T Test Chart No. 4) featuring various resolution and contrast tests, including line patterns, character sets in multiple languages, and numerical scales.
+
+T0814420-93/d02
+
+### Test chart 5 – Pattern arrangement
+
+1
+
+2
+
+3
+
+4
+
+5
+
+6
+
+T0813010-93/d03
+
+![Color calibration chart with 16 color patches and grayscale bars.](0f2a1e4a7b12fe5b8749882ecd636f5c_img.jpg)
+
+A color calibration chart featuring two horizontal bars at the top: a black-to-white gradient bar and a white-to-black gradient bar. Below these are 16 numbered color patches (1-16) arranged in a single row. To the left of the patches are three rows labeled A, B, and C. Row A contains 16 grayscale patches from white to black. Row B contains 16 grayscale patches from light gray to dark gray. Row C contains 16 grayscale patches from medium gray to black.
+
+Color calibration chart with 16 color patches and grayscale bars.
+
+![Horizontal grayscale calibration bar.](5f8af0cfcf796986f40e70571bb950f5_img.jpg)
+
+A horizontal grayscale calibration bar consisting of 16 distinct horizontal bands of varying shades of gray, ranging from black at the top to white at the bottom.
+
+Horizontal grayscale calibration bar.
+
+![Black and white photograph of a classical building with arches.](bb6d33498937738ff5dac8d91c9ebaad_img.jpg)
+
+A black and white photograph of a classical building with multiple levels of arches and columns, viewed through a foreground archway.
+
+Black and white photograph of a classical building with arches.
+
+![Black and white portrait of a man wearing a cap.](0cc86fe8fc37b0edc9581f2af9459a52_img.jpg)
+
+A black and white portrait of a man with a mustache, wearing a dark cap and a light-colored shirt, looking slightly to the side.
+
+Black and white portrait of a man wearing a cap.
+
+T0814410-93
+
+CONTINUOUS TONE FACSIMILE TEST CHART CTO1 ITU-T TEST CHART No 5
\ No newline at end of file
diff --git a/marked/T/T-REC-T.23-199404-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/T/T-REC-T.23-199404-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..173615024ed34987f0e2b4b174132278e1fe11a3
--- /dev/null
+++ b/marked/T/T-REC-T.23-199404-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:a3ec95b4c6a359c98c33d6c299fc9956b421c5836fd12c405c2247e2b79a1d93
+size 8289
diff --git a/marked/T/T-REC-T.23-199404-I_PDF-E/440e59dae4772c0152116a3abd34331a_img.jpg b/marked/T/T-REC-T.23-199404-I_PDF-E/440e59dae4772c0152116a3abd34331a_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..8759bd26c4a38e586b65e76bd7ccaf6b1abe261d
--- /dev/null
+++ b/marked/T/T-REC-T.23-199404-I_PDF-E/440e59dae4772c0152116a3abd34331a_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:7771469b531414ab9b2cc77d543cf40ce8c719e80a770771312bcea10627ec87
+size 233432
diff --git a/marked/T/T-REC-T.23-199404-I_PDF-E/a738993919a50143787084ee7ce6e2f2_img.jpg b/marked/T/T-REC-T.23-199404-I_PDF-E/a738993919a50143787084ee7ce6e2f2_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..699a9b040ace6b70550f0b182ae5c6d926882e1a
--- /dev/null
+++ b/marked/T/T-REC-T.23-199404-I_PDF-E/a738993919a50143787084ee7ce6e2f2_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:96093b10032c4e4bb7164eed2874e48a7b21257d3208f765786842f130ff6a1b
+size 88365
diff --git a/marked/T/T-REC-T.23-199404-I_PDF-E/adb1f42239329fa8283d1a40005f989f_img.jpg b/marked/T/T-REC-T.23-199404-I_PDF-E/adb1f42239329fa8283d1a40005f989f_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..872630fdf6134c9c7bee840d821ca6d6dafa5bea
--- /dev/null
+++ b/marked/T/T-REC-T.23-199404-I_PDF-E/adb1f42239329fa8283d1a40005f989f_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:df4a2263c730dec109a0d63a0718155ae3a7182209efcf5c29774eb9c16a3e07
+size 57897
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/00a0b3a0485d8e735df9cb73dbdf36d6_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/00a0b3a0485d8e735df9cb73dbdf36d6_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..97d87392667e4f012ce76f2c08a97126808ba416
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/00a0b3a0485d8e735df9cb73dbdf36d6_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:7a6545f76b429615f3acd47daf351b00e6f63d36e94b29268d1c665b548ceb13
+size 82770
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/028803093e6d1195c9c470b0abd490c6_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/028803093e6d1195c9c470b0abd490c6_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..e478120497a76003d69c5f59f4fd7d9938558c9a
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/028803093e6d1195c9c470b0abd490c6_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:4078ef7aa69fe27cdf08a39f729868d0d60236df0bb5bc0f30ce3046b32face2
+size 90829
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/0317016f1967843fe2643d09bd7bee9d_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/0317016f1967843fe2643d09bd7bee9d_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..1ed48428cb6d018b3b040dc24f3d5049c0479089
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/0317016f1967843fe2643d09bd7bee9d_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:a3deafbfae2c574bc4ecd5973fd0f71a543591b4399fc5c5df0e975016d28e68
+size 74919
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/031de8ea6c5568a02faffd59b5c337f7_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/031de8ea6c5568a02faffd59b5c337f7_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..5548caf07ce53cb058fb8915956c0406f62380b2
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/031de8ea6c5568a02faffd59b5c337f7_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:c6b6eca51c07319c9d5dfff429498b1c50d202a0fdad0c44179aa74f0e789ae2
+size 70913
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/034e9e9df7d08c9361f774ccc42653dd_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/034e9e9df7d08c9361f774ccc42653dd_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..61129d2d9418fcef978f056c4aea7e1935bebb5d
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/034e9e9df7d08c9361f774ccc42653dd_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:19e9f2372bf82c49dbb51a8d970062e37496fb3368586cdcebfa9ca6b89d7e7c
+size 39233
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/0430961685816a74c8faf59054dac844_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/0430961685816a74c8faf59054dac844_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..e61152b76dcbea1fe88fb9f2a2763c4c25f179f2
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/0430961685816a74c8faf59054dac844_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:66279b6b57e1b2f391051a1a2f0339c34f43a750bd97d36a45688bccd51b15aa
+size 21856
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/04ec44ae764ec85291cd94eb5e663da1_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/04ec44ae764ec85291cd94eb5e663da1_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..841fbff8e75b39eff047c1bacd7dca60dd9bfec2
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/04ec44ae764ec85291cd94eb5e663da1_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:54db2f8baac82ae78b94be791aa08c583b5a2c140ec6ee3428115cbfd0a7c015
+size 38916
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/08a978a124d3ed6cf1a3d0cfd89418d0_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/08a978a124d3ed6cf1a3d0cfd89418d0_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..682897fbd3788fcb3057f02dc74e00fab2245290
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/08a978a124d3ed6cf1a3d0cfd89418d0_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:fe4a5bad44886b778b8f6ec5a8f261bfe8f3e76b2cfff498fda84749e7ed09ff
+size 110072
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/08dce7ad4c512fdf0c0cde60415fade6_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/08dce7ad4c512fdf0c0cde60415fade6_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..090735b1d7e747b9e05ff404d5b1c15d341c2a49
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/08dce7ad4c512fdf0c0cde60415fade6_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:0de878463d82ff0a7b783956345af639a33c43f912eb5515f6321342587412ea
+size 110746
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/0a42e05c07941450f34e4f7117725834_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/0a42e05c07941450f34e4f7117725834_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..1db0fde196a4af4300cb1c79f6c7a5c8cc3392cc
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/0a42e05c07941450f34e4f7117725834_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:fd7546302dd93744d6c6dcf6e9f01ef68a6a4fcb824a988e507ebb75adcd3f18
+size 135210
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/0c47111d859618d4b5ab9b334ec3641a_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/0c47111d859618d4b5ab9b334ec3641a_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..8d3f2399afdb4b567fc9f47f7f653f98c892149c
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/0c47111d859618d4b5ab9b334ec3641a_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:65820dd901267c64b6144f7c8a4cb56e812030c81f61b8c0d62a7ce0878bbda5
+size 19663
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/0c52cbf5660095ad246a36ecdfd11674_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/0c52cbf5660095ad246a36ecdfd11674_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..c4d62652de3fb9394f9679b203668475d9ea0ab7
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/0c52cbf5660095ad246a36ecdfd11674_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:f3e0bf29d99af512fde673979a787d8e72145662f476e9d4118a5d9599f5ce5c
+size 25860
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/0ccaa59b5bc46884777e728ee3dadaa7_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/0ccaa59b5bc46884777e728ee3dadaa7_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..0966b4a75e5b26a5294c75d4deb741511730c78b
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/0ccaa59b5bc46884777e728ee3dadaa7_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:885266892923744778db158ad6a0c028aa12818d9c32fd148408da89c6c484ea
+size 40933
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/10f4e3a2f3c016555ee12a5b556ba834_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/10f4e3a2f3c016555ee12a5b556ba834_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..f5622660cf9c72e9daefd59a069b6441db9ea76d
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/10f4e3a2f3c016555ee12a5b556ba834_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:0012ce6ade4266458a1e23055ff5e666287a6260af9a90f99bd1d7fcad4e10bb
+size 43268
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/11edb7fcedf09ac6a817f8d7b8c61eec_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/11edb7fcedf09ac6a817f8d7b8c61eec_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..5f2cec9ee3822d6b82b13d02a3921684551332e9
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/11edb7fcedf09ac6a817f8d7b8c61eec_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:b2d0875c2386017c7442d38c628da4b46a33b11eaeb1ace9f41eb6765575ffa4
+size 220904
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/123eec6e76ec730433647d09867bf6b2_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/123eec6e76ec730433647d09867bf6b2_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..e4e6de25e0eb18f3a7f3adf44a32c0999069d694
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/123eec6e76ec730433647d09867bf6b2_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:e41a6d6ebd816148d29869c55994e8d4423aa8edffd79f74ae7f9213d28d4047
+size 87943
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/12c19090355e19922e23044633b9d1ea_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/12c19090355e19922e23044633b9d1ea_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..f83762b1e223eb29929d592aa9a7cb2098cd0053
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/12c19090355e19922e23044633b9d1ea_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:926c7da7bcd52a0ac8ce5667ec10442346f72c0d975805b1173090eba5115b80
+size 47979
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/143c8ee1010bf7669caabfbed815df1b_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/143c8ee1010bf7669caabfbed815df1b_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..82cc6f4d40f65447dc47c5a7af723ad1388fb122
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/143c8ee1010bf7669caabfbed815df1b_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:1ba2fbdb64aec8822e28753e24a8f0683170cc470d320fb527ee8c8bb33718c6
+size 83695
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/1582c665ca9405e127473c291eaed480_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/1582c665ca9405e127473c291eaed480_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..db92ef6af52fc2227c92490eb5dcd9dc7350756f
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/1582c665ca9405e127473c291eaed480_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:c504f26afa2cf7e713d5c3316b96ee375464a6bc252741b34a27f0ab8e774759
+size 177703
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/16563dc7c141a645e1b8cd9c4aa1cb23_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/16563dc7c141a645e1b8cd9c4aa1cb23_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..818ed16d6cf2e7397d2d341fec6ff1a47a0c9089
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/16563dc7c141a645e1b8cd9c4aa1cb23_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:fd4d7eebbdfce2617a9449ad29eb582f98638f9ecdab049e9bb52e8f012fd77a
+size 45010
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/1675f8038d3084252c0aae7b648814d2_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/1675f8038d3084252c0aae7b648814d2_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..7d12aa710b705b4a610fff252d37812dabdc584e
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/1675f8038d3084252c0aae7b648814d2_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:1e7811527bfa71707f01b28f3054d4da10e5963c157872b276efa31297cc9809
+size 84633
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/199607ec43a5b7ad43b1896e152e742b_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/199607ec43a5b7ad43b1896e152e742b_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..93799489c65babc222e375ef06398e50f42e69fb
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/199607ec43a5b7ad43b1896e152e742b_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:a0a1570e4cd1c6a5cbf73ffa846c264fa9d59fd0f90a0881681bbff693222544
+size 99127
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/1d62ade6b682fdfb8e192d10a06246a4_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/1d62ade6b682fdfb8e192d10a06246a4_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..8ae726ae1f13b27962218381226c5889fd29418d
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/1d62ade6b682fdfb8e192d10a06246a4_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:9398501a66ef00e767b36f5921ba3a9ad1581d2feaeba80d4e68961aee926e3a
+size 96851
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/1d9db146e81fd7b66f1a05cce57c7112_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/1d9db146e81fd7b66f1a05cce57c7112_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..e78ada659a07108bceabf72a670e86388410be78
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/1d9db146e81fd7b66f1a05cce57c7112_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:434c21214217b7be6c8e77ecdb88fd3da1d5d6f7bef176a79ffba1f5dd5819cd
+size 89657
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/1daee79ab1ab652586116f083d50ed9d_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/1daee79ab1ab652586116f083d50ed9d_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..4d40acf76121f4fccdf91de9de4e8ba376f108ee
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/1daee79ab1ab652586116f083d50ed9d_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:56fc1d6604c57dada6ed90c51a4b82b905c24cbb1d57378732a36edf844d438c
+size 82425
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/1dd97d21e745e17aa9bf424cac55737d_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/1dd97d21e745e17aa9bf424cac55737d_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..741124591f3173695d3eb38a4db4377ed3a5615e
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/1dd97d21e745e17aa9bf424cac55737d_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:4f3c59d563ce657757a24cd53863da22ac074623194d7b4b8e0b53ae225fd0dc
+size 41893
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/25b2ef5bcf30bfa9a31d59f48fddb3a7_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/25b2ef5bcf30bfa9a31d59f48fddb3a7_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..f4bb90f31fdd998d3579c609edd2163211f00930
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/25b2ef5bcf30bfa9a31d59f48fddb3a7_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:6eada73a980135983cf3efd883d9a99363045875490b1d6e24af7d97dc518e87
+size 91102
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/26d6d8d333f84acff82b7a9f9b303da6_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/26d6d8d333f84acff82b7a9f9b303da6_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..9415b82e67dbf73dd466023293d98d3c05efa5f7
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/26d6d8d333f84acff82b7a9f9b303da6_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:b51f36715c84cff04c35eeb7a5591080079179a1f338a35adfc17c5b147f34d9
+size 137913
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/2810d94a8fabcf09cbed8122b6860609_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/2810d94a8fabcf09cbed8122b6860609_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..2fb6289584aeda93b54250829f65fa0d0c352d40
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/2810d94a8fabcf09cbed8122b6860609_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:6f22354971ea1d31a2cbe0ed47930ffdcaff696fc495470f138a0878afe6f0c2
+size 93587
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/29aa6165ccf449dee0b4335676fa7b1a_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/29aa6165ccf449dee0b4335676fa7b1a_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..36f33572ba4cb77be5742df6008458ced6395725
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/29aa6165ccf449dee0b4335676fa7b1a_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:ac4e4e6dd6e48ac862046d5fa805e67d3d3de4cd255f0395c4edf5d411fabf40
+size 70787
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/2b4d94db97c0fb76bc846c812e5f2127_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/2b4d94db97c0fb76bc846c812e5f2127_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..174f139e1c487050241bce2e8e3c4d57d4f3e3bf
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/2b4d94db97c0fb76bc846c812e5f2127_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:7c232389722438c42ecd0ed1e7c2bad9b0c3186ff481a3c8e6af90dc89836e49
+size 165476
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/3069a023e71b03c236b8d4ca8d49452c_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/3069a023e71b03c236b8d4ca8d49452c_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..98fde6ee9dcc2e0b980a4c6ef14231ee2d8694a3
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/3069a023e71b03c236b8d4ca8d49452c_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:cdce5a8bf110db8cad5eb80131b83da8ba0ceda0dad925d92ef4956569eb5e31
+size 49233
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/3100b9f8708f586e472f3d9e44f10e52_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/3100b9f8708f586e472f3d9e44f10e52_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..45593563b7af36c798ccbfd9c8efad326fc4fe14
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/3100b9f8708f586e472f3d9e44f10e52_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:2d6308a97207af1177d4cb19bbed888bb2fed06b64aeb9671acef038bebb2913
+size 66881
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/3220d3a933797114c1ba20d5c4ec093d_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/3220d3a933797114c1ba20d5c4ec093d_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..d3b43a30ab89abdd45962605c9d91a9abb49d88a
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/3220d3a933797114c1ba20d5c4ec093d_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:fbc44d88d4f8ab01206a7e84df80555dd01aaf937854a646d5de92ac058cc700
+size 45128
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/32f264af2367681436292b13acdfd2f9_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/32f264af2367681436292b13acdfd2f9_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..85747676581a3ff513fa57485882e6b17618822f
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/32f264af2367681436292b13acdfd2f9_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:72666617c4b7c1d9ce7474a95f912333b0503373b5d4d8fb523419ffd291e7af
+size 29909
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/32fef1546b300cd971dacf02ca1d21d7_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/32fef1546b300cd971dacf02ca1d21d7_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..4ee9d1e36d76a1ac211623f450c791bbe16b16d6
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/32fef1546b300cd971dacf02ca1d21d7_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:ed77b44ede07a52cce924bc990bbe48a6b6ce7a5c1f860a2f1dc70894659a5cd
+size 132860
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/33013933550b78b0f07d622a01705b10_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/33013933550b78b0f07d622a01705b10_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..d1ea6d8c12137dc74f20c5a07133b8fcf6e962c0
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/33013933550b78b0f07d622a01705b10_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:c3eeb573cdf7d0190449117c5e2e9c962afcfb8ad1f569d22be6c13faa99930a
+size 16833
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/33d39ec22f2b13308b36d07d0af593e1_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/33d39ec22f2b13308b36d07d0af593e1_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..89316096e2de7ac520cacc345bc29463e549d6d9
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/33d39ec22f2b13308b36d07d0af593e1_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:6b3ca9a68bb2d935fb38b317933591d26e5a2693a2e6bc10c35bc61a753897e5
+size 93639
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/33d95af6c9ade7cf0415756cc5ea9803_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/33d95af6c9ade7cf0415756cc5ea9803_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..af57211a3a83d40ce8461b0e44cbad7ef53f7e75
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/33d95af6c9ade7cf0415756cc5ea9803_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:96bbb80a90c6cd519a9aae4dc1db4d2b14ca9e46aadb8e0c63c3e3b73bb71e7c
+size 113912
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/3429a2cee05dee88538d8b6816a5a877_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/3429a2cee05dee88538d8b6816a5a877_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..ad6794f57c0ebe3ab37f255a0ad114d76c12decb
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/3429a2cee05dee88538d8b6816a5a877_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:9f47635b446273204d73a2149a9a7111db31e75e88db3052162ad0c2fd8607f9
+size 114966
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/3481cde1adf61b0452dd6489dada6d6a_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/3481cde1adf61b0452dd6489dada6d6a_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..23e2a455cb9f2c0c556a58aa3f4937e6bd4d4018
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/3481cde1adf61b0452dd6489dada6d6a_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:bfee409546f129a84c7e7e79b4b82ca841bdc2131fe2e6a92a76e15d15924f36
+size 44468
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/365b54f616aff249b4e6c0edafdcb9b3_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/365b54f616aff249b4e6c0edafdcb9b3_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..f5219a20b109a3d642d11fff31fd5ba8df3da1f8
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/365b54f616aff249b4e6c0edafdcb9b3_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:215dff723752f25d2a51201091e90f954bc7a591459821dacdad60e0a25bc49b
+size 133721
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/366a77fdefb0097b3289b4a011911390_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/366a77fdefb0097b3289b4a011911390_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..2afbb67d3e56961409b0a112630c528897da76e1
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/366a77fdefb0097b3289b4a011911390_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:16cf9f51d5c79feeea15d6abf4232e2e0392c32b3378621c1125aa531bd24d32
+size 44720
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/3809104951720e80671ab7c4cf470f9a_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/3809104951720e80671ab7c4cf470f9a_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..3feffd10f868529eaa82b2b1865bc803d15720ee
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/3809104951720e80671ab7c4cf470f9a_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:25ed49dfce5fa9c5d616f09ecb09e8c9ea98f216bf53a28863dc65eb553beff3
+size 20670
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/38326516c33003c1d5f103e26466d4fa_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/38326516c33003c1d5f103e26466d4fa_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..07e3d33a86dec9e480d1977e12419b9ac36a2e01
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/38326516c33003c1d5f103e26466d4fa_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:8f52484b3a0e2b4d1e942e049a2d866ff6a83b1ed6b4e2693cdfa6ab82ef7e6e
+size 48121
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/38cbce07f83fba6d5a7c46605bd5743f_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/38cbce07f83fba6d5a7c46605bd5743f_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..305a90b94ece55d250236499c8722129dd22f0b2
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/38cbce07f83fba6d5a7c46605bd5743f_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:faa003f9139d6d174858f3163a23666979b2319e862460721a6dd16e05b477c4
+size 51992
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/39148db4c9dfc296c5abced7b560a75b_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/39148db4c9dfc296c5abced7b560a75b_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..8faa4a151345105c5cf765976d41fcd1a3a42697
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/39148db4c9dfc296c5abced7b560a75b_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:04ad47ba687c71154519fcb0c2da6ab49139885791c1de4b202599ffc588e4e7
+size 103786
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/3af2fc22afa44863b4fdcb07aa719bc9_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/3af2fc22afa44863b4fdcb07aa719bc9_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..937988b830eb08abeef456a0a342b751f014e495
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/3af2fc22afa44863b4fdcb07aa719bc9_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:a077ed558b4aaece47bcd6867900b31a4cfa80fd3865516f81294574f656f80d
+size 57743
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/3c51c7ad97fe744faddbbdc1053bdbeb_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/3c51c7ad97fe744faddbbdc1053bdbeb_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..bffed46fd34e26e374a67042f1788b874dc2b664
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/3c51c7ad97fe744faddbbdc1053bdbeb_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:0bf19d7bf04bcf363ca1189f3a441d844808091d2e224c6ebd933e6e7bfa0c97
+size 25643
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/3c721884a92b102becb43b52f6110e47_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/3c721884a92b102becb43b52f6110e47_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..c06d194c64ae7a409081ef32652f6ba2563ebdce
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/3c721884a92b102becb43b52f6110e47_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:09cf789190f4c6c03785bb3fb1c21992315e699872d519e3947e6c0705a6fc5b
+size 74456
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/3ce6b213ec556257e32ff7451182369d_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/3ce6b213ec556257e32ff7451182369d_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..43e302cb5702955f9e6d067dd918aceb84f2d09d
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/3ce6b213ec556257e32ff7451182369d_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:a8389fdfd5376374c21c625f372d44fc85396431adb26938f18005cf4ec440e4
+size 92508
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/3d13999d5257e24e629f65f28bf10251_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/3d13999d5257e24e629f65f28bf10251_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..0bdb2eef2d1564e90008d830b6dbe1fe9bdbd059
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/3d13999d5257e24e629f65f28bf10251_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:ff4afd2562a76f3f10ed9d1f2529c670db1fe0afbf6fea33ae1cef472c435ae1
+size 61713
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/3d1ae2a6b8a50db31e4930b5da97fc95_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/3d1ae2a6b8a50db31e4930b5da97fc95_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..6d03a7469ce60fd3afe524969762e437337e85f0
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/3d1ae2a6b8a50db31e4930b5da97fc95_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:bfb1377256d2f839cfc258db6704126fc7cf2059f54990a5e1ca5f96a1746672
+size 137714
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/3df1d2bf049815d761b03fb9cc2bc7ed_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/3df1d2bf049815d761b03fb9cc2bc7ed_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..473152c51684e16ed6250f077006c27b167a33cd
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/3df1d2bf049815d761b03fb9cc2bc7ed_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:6dba3c05cdee2db0f9687c8adf0f6993b175e55c46153fddd38f1ffa3ab6612e
+size 56770
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/3e8b6c66edbfbca22863e12c1062afac_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/3e8b6c66edbfbca22863e12c1062afac_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..66e664330f7eb1f62ec14e9676ab490acb4b6bdc
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/3e8b6c66edbfbca22863e12c1062afac_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:392d633aa7e1ee149004f667a780cc402b53abf4c2004c23a02f3c4b3f85150b
+size 45329
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/3f1b6583b85a3ffee7d3341f131a657c_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/3f1b6583b85a3ffee7d3341f131a657c_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..5aed22c5e6a4fc38c5e094568597208519933428
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/3f1b6583b85a3ffee7d3341f131a657c_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:c7b2a12102dae83399d95833c548ea7bfd08b9506f392efbee24cd0385a2154e
+size 69965
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/401f020d9ab5904f584424eabb596d2c_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/401f020d9ab5904f584424eabb596d2c_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..3ece255f142a8e8fc6cc0ccf976493a51d4edd32
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/401f020d9ab5904f584424eabb596d2c_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:c98330edd340b34fe183471e070b45f0fc7cf826fd54213f0bfeebc51e7fb05b
+size 57896
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/42d94bb6cf8d257623490abe9b2c0188_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/42d94bb6cf8d257623490abe9b2c0188_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..aa3adf45a28d67851398f184893b89568cd93ee2
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/42d94bb6cf8d257623490abe9b2c0188_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:571c46c9df06ff2d11f077e99cd4a3d006a0b8bcd45dfe9233c7788240ce9551
+size 29396
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/4562b7df9e2e257eac16ccb0e5eb8932_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/4562b7df9e2e257eac16ccb0e5eb8932_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..2ff539e660a92b5ae6183331dda78b55ecad2b70
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/4562b7df9e2e257eac16ccb0e5eb8932_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:1800a00944ae59622ddd88c0f9a91f233b3cf8b89802d41cac8efc4b746e5fe5
+size 115373
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/45b810f0e4539dc7a7ddde549defc08f_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/45b810f0e4539dc7a7ddde549defc08f_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..748b85a03409a564c8dc349e253d5f6c274c19d1
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/45b810f0e4539dc7a7ddde549defc08f_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:e9c55d36317af768f1921b8f48f6522757e0ea700c252fc7cae282f5c25069d8
+size 30271
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/47702b55f927e2e85ac03e79a7ebe350_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/47702b55f927e2e85ac03e79a7ebe350_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..b4a674cbcbecdbea71ef9a98e39d0f788d1a6061
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/47702b55f927e2e85ac03e79a7ebe350_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:bffe3d91763ecba54256a66754bca01e614370f27f81f5ae5bddbc17257ca08b
+size 93336
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/4851479cde0f63d07f4db536c69bbdef_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/4851479cde0f63d07f4db536c69bbdef_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..f25d829a889696a3c21de3484c1cfcc8b38df242
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/4851479cde0f63d07f4db536c69bbdef_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:d9b886e6e53fc57f495380b08a8c9d458ed42f37f9d2e9cccd284b69f3aad028
+size 53023
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/4ae4505e885586e481a3ad3bff5198b7_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/4ae4505e885586e481a3ad3bff5198b7_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..63c0d4f465a62733e5e36706b79ed8ffcd7b35aa
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/4ae4505e885586e481a3ad3bff5198b7_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:4ae0f0f625d3b0744e4e0d967793aec3e6c1eaee43afff182357b722036b92c2
+size 97895
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/4aee0befd462bc1dc8b0a556275fd14e_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/4aee0befd462bc1dc8b0a556275fd14e_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..3727d65d5fb71fe9cf632ab54b919dca216018d9
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/4aee0befd462bc1dc8b0a556275fd14e_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:d6c1c9ac730db80639aa24e92ebdab9c932776ccfc1cf266410f99a047b12ef4
+size 34650
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/4b4c0ab4b626b263181cead3042e06eb_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/4b4c0ab4b626b263181cead3042e06eb_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..fa08c90f1fe8af0f97cfdab909469276e839a9cd
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/4b4c0ab4b626b263181cead3042e06eb_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:70abb3f3bab0b53d1c3d131af37e649ed369fe6d4dd688413af39874d73a3bd5
+size 84455
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/4c4cd9cc5afb43f9e3111e1ba45e701a_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/4c4cd9cc5afb43f9e3111e1ba45e701a_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..0f0c6687c7925a2a2e0693254d8c9da0b1fc23da
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/4c4cd9cc5afb43f9e3111e1ba45e701a_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:24bbb8e5a8bae158088a66db0573f8a15ecb93e29c51738cf80fdd1038d1439d
+size 151951
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/4cb497b8657c6247d4faab7691cd93f2_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/4cb497b8657c6247d4faab7691cd93f2_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..d59bf7289542cdfaf45b97e526385bc7987ca1e2
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/4cb497b8657c6247d4faab7691cd93f2_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:6a3e5db28b83e19385832ba1f91e38ebe5bef3f1922cf6a89e15d48012c3b1a0
+size 24514
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/4cf20a1cc0755dff37937135bda4e2c6_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/4cf20a1cc0755dff37937135bda4e2c6_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..ffbef42daa1002a73283d5b15074ff84f19396a0
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/4cf20a1cc0755dff37937135bda4e2c6_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:79127246104ea799e199c0522155981196f09eb7a092ba781e8b8be5a2fe2c6d
+size 49396
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/4ef412e08808c40e0beb7808d36b9379_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/4ef412e08808c40e0beb7808d36b9379_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..7a80151b6d3991c0c2b65a0af86a6efe74b497eb
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/4ef412e08808c40e0beb7808d36b9379_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:4097a3b68059c3e69a158b4d40c02a25202352981cf6590c6b641807581146ba
+size 92931
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/507613acfd7f6ef6af724a2005f24024_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/507613acfd7f6ef6af724a2005f24024_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..52c9e1e1cc9abda89c2fbd02ee50bbc13feb7720
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/507613acfd7f6ef6af724a2005f24024_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:3ae37a5f93bde1c15f95483fc0768a19521f2da77270de157b3b15d7042c6a9d
+size 61419
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/51167ecef86d85cdc6dde05a3afb74b8_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/51167ecef86d85cdc6dde05a3afb74b8_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..5a69294a7b9918fb0f5f90cc1a8b2aee413f2063
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/51167ecef86d85cdc6dde05a3afb74b8_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:86c0b1d1f9c9bbbcde1155e14da375fc5dcf3479e1c74aa96da026a9df4b2637
+size 71052
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/51501a01b2c29ac95e126882508f8831_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/51501a01b2c29ac95e126882508f8831_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..c0db87449b0a27ee26a81231e519a59846d1534b
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/51501a01b2c29ac95e126882508f8831_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:ed336ba92ff8dedfd894ddfd9791be8b302efe9ca79022559c124221838b0c71
+size 43754
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/53499879d98034410ecba2c386c58f0c_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/53499879d98034410ecba2c386c58f0c_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..88ee9b1c161ad4cb92fd70b88405675063ce6ca5
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/53499879d98034410ecba2c386c58f0c_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:8787ef7a555fb36fee2751c6445cfd896e285fc404efb5d2b94bb0d355d1c7cf
+size 70516
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/543dbf9a0f62120aacfce4baebce2b06_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/543dbf9a0f62120aacfce4baebce2b06_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..b729cfbec8fb72a35a3d7dfc8efb649b0aa9bddc
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/543dbf9a0f62120aacfce4baebce2b06_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:09d3c8d53f0d4ba54de35daa0d2dad38a02987597eaca06c8f9456916a87b382
+size 49486
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/54a1e5d91d7f442361767b1f8c81c777_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/54a1e5d91d7f442361767b1f8c81c777_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..7b9229bfe10eb93e36a4357e414fb2959295d663
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/54a1e5d91d7f442361767b1f8c81c777_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:8bdfca17f1d6e72ca046960c8260ce6919a4baff99598e6d52d08afc9f3c0c54
+size 105156
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/55f11fbbe5ef616ee7a1814f932acbaa_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/55f11fbbe5ef616ee7a1814f932acbaa_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..32aacdcc8aefe853ea57adbd68e1e268191a80c4
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/55f11fbbe5ef616ee7a1814f932acbaa_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:b0e6dedfefb5887802e4242f3896399bda3b0ab70e43dd014dade6acc7e73b99
+size 91174
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/5a3dccee8ce4d2fa1986aba4ae8ad6e2_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/5a3dccee8ce4d2fa1986aba4ae8ad6e2_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..59669b218a2c201aa99aa18ed4b5f824026f0f33
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/5a3dccee8ce4d2fa1986aba4ae8ad6e2_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:eee9af6b518782b34e5bddc9a00601ce71be1a1b323bee7c1949848a3b5b3e55
+size 112010
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/5b2d39d25213a565ea34f3d22befcc49_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/5b2d39d25213a565ea34f3d22befcc49_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..96888475d2f377591ff0bfe0a9969ce72849bae2
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/5b2d39d25213a565ea34f3d22befcc49_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:cb59966074b0a73f9bfdbfbc7fbefb4652d4b20f4f26160c7232f8279c540396
+size 25979
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/5b41b3f299c364a673453693f7cf0689_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/5b41b3f299c364a673453693f7cf0689_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..7c3d0afeaa4f5425f32c5c59fbdf267177351000
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/5b41b3f299c364a673453693f7cf0689_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:bbc331f8ce561ab98f25b8b54b31a76eab0a5a8227f10d21e8e7cc1b9daad658
+size 41626
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/5c62022cb5436e57bc6748b98ce6d2c8_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/5c62022cb5436e57bc6748b98ce6d2c8_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..92b0c2e8e4f4b98c5f73704c964f541898dc9027
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/5c62022cb5436e57bc6748b98ce6d2c8_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:cfc6a2dfb652af5966f63b0f4c1dc419e130b09ae062b8e8b8f99734a6b9a625
+size 21050
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/5c690861d263afceef4f7ab56ab13264_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/5c690861d263afceef4f7ab56ab13264_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..fe9001f2ecda192946f1303dc7f84ff88bdff757
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/5c690861d263afceef4f7ab56ab13264_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:1529712139f1da092a465d00d2b72f10978cc39b010b2a47c7c57c86f5b65729
+size 75089
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/5e022ae60ba810b1e6de0645671b9dd3_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/5e022ae60ba810b1e6de0645671b9dd3_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..ecf893fe48800fc14f9f0faa74fcba3639e7fa9a
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/5e022ae60ba810b1e6de0645671b9dd3_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:06c754e2d93b85ff964109206045e4d24b182cf997bb5d893f9b799cb824dd63
+size 60373
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/5e90ca04dc493a9f9aabbdbb720d39d6_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/5e90ca04dc493a9f9aabbdbb720d39d6_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..017ec1ce21fd3848cf33690afb364fd9b2fa8a76
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/5e90ca04dc493a9f9aabbdbb720d39d6_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:f85fb30aaf8765b7a7be8754ad5f005d8572c55adbe5f5820b43d7cd7867da03
+size 124105
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/5eb69662cc4fa7d0d49b4eb22951c204_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/5eb69662cc4fa7d0d49b4eb22951c204_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..c208711f6461ade7be3f9b793bbe6651ad4dd441
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/5eb69662cc4fa7d0d49b4eb22951c204_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:8fc8e796fa06b47e118deeb72a5cad5729661101911a7ad67ca50d7766dc6ca3
+size 63855
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/5ec3284657e4df0df3653dd61d0ecd13_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/5ec3284657e4df0df3653dd61d0ecd13_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..8b11a6f24c7338ee681e45750bc5f029b194d4a1
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/5ec3284657e4df0df3653dd61d0ecd13_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:d814c4bb4be546b3f1e93e65e64665dbcfba64fcc2396351c0fb77cf2149f692
+size 58115
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/5ee1bbbf85b473f78af9ec8368a4159a_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/5ee1bbbf85b473f78af9ec8368a4159a_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..00995237b25af50282ac5ed29ade10935583f238
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/5ee1bbbf85b473f78af9ec8368a4159a_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:1449d698d914aafecf0cac732be2e96d9f2ffb81eca40fc97a6e5ff828f0d8a9
+size 51185
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/5ee80a63ec53c60d7306b5a44984afcf_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/5ee80a63ec53c60d7306b5a44984afcf_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..3af2b6ec19d075176398f54e5e076731370ea6f5
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/5ee80a63ec53c60d7306b5a44984afcf_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:f27a63bf5d0b817ad063e02370b382ee3595412ed906524279c5561aa39ddab3
+size 88450
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/5fa2a363bcfaa9255ff936aad4e243ce_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/5fa2a363bcfaa9255ff936aad4e243ce_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..32628fb474e5a498a2ccba4e93bf7519786a6a99
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/5fa2a363bcfaa9255ff936aad4e243ce_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:24637e3ea446d0875fe259f30087cc59a6201b0978dc210c42b3f81087c094e2
+size 146360
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/5ff967638ed80b570723c608aa77fa39_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/5ff967638ed80b570723c608aa77fa39_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..b6d0a8c5cca89ce52e73efde67d0545cefaa416c
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/5ff967638ed80b570723c608aa77fa39_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:2c23c5c1a9d8d48d14d23ae15494ab7acfb7ee1d00459a2e1b373d3cf552c9b2
+size 38993
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/60f844d947ea0bccdd9f64d81d5f8d26_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/60f844d947ea0bccdd9f64d81d5f8d26_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..dcee21fe12d8560d63841a1931d74a6c956178fb
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/60f844d947ea0bccdd9f64d81d5f8d26_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:e12c827151bd3bf625c97c3a98202a16d2500cb8c94fb726511dfc3a6828c2eb
+size 103495
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/61887c08b198861558621bc776880d6d_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/61887c08b198861558621bc776880d6d_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..0cccf6f8d48f51644cdf239698b5fa422d26a6dc
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/61887c08b198861558621bc776880d6d_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:3ecc549459995401219eead59fb82b8bccfb49ae671aa72f287d4a4a1e405575
+size 105428
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/61c08b1e5f00e659941d459eb3d567e0_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/61c08b1e5f00e659941d459eb3d567e0_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..10c8df67b23faaa2f90f652eb69c556dfcc9e54e
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/61c08b1e5f00e659941d459eb3d567e0_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:8cb087c35abefe034cdd4ffd091aa4f8622c944dc9b149df842cfa13ed34b736
+size 101147
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/62c855224c9ca68e4f6998b9575e607d_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/62c855224c9ca68e4f6998b9575e607d_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..fb5cb58803873ea81e5ee009b4064edf694e11e9
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/62c855224c9ca68e4f6998b9575e607d_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:ffd84d265fee37152ada7ec14a34b2788126f1acdb3e139b4a8faf0e3f444ace
+size 86016
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/63e5fe58c604c0b282b186ee78b760ae_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/63e5fe58c604c0b282b186ee78b760ae_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..e80ccdecdda8a73d1afc91eeea753d64102cb0a3
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/63e5fe58c604c0b282b186ee78b760ae_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:2f456738df1a53a73a4ec89f72798f69cb62ffcc4255960c0f685517300258ea
+size 49193
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/6762c05f927b2b9c2404c465ef0a8d01_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/6762c05f927b2b9c2404c465ef0a8d01_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..93cc1ddf3daf552af5c1fab7bcf5ce598ba82787
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/6762c05f927b2b9c2404c465ef0a8d01_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:e8e3775fdec4b7f83cb986d526cb358ee9366a832f9a0950cfb22429e1a8a7fc
+size 121320
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/67cbb5a621a69ab58534bb3376bbb724_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/67cbb5a621a69ab58534bb3376bbb724_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..6dbf7c09311032c38fd635f4cb2af1e430f3be06
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/67cbb5a621a69ab58534bb3376bbb724_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:c58a5be485f46c70980da5b6736a16d647ca60226a90678d2d6e91b1ef2fc476
+size 92344
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/691626a7032a642bb74793336c37e274_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/691626a7032a642bb74793336c37e274_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..bba5950b121f84ecc4534821da11e2de49110614
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/691626a7032a642bb74793336c37e274_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:07b8274bbff6d3e52f8be32a8ebb5881c4d43bdf79bbfaf2624fe1264b14ee03
+size 56536
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/692541e65db4dc852988ce77ebb60ce5_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/692541e65db4dc852988ce77ebb60ce5_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..174f2d65b3b03318ece2d8e616c12a20d792ffd6
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/692541e65db4dc852988ce77ebb60ce5_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:010c4527c599ae1be06df7e48caeb1a1c455d5e4865958752df56cfe5a234ffc
+size 41664
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/69b7bd65e85cdef6fdd7fb0a8194257c_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/69b7bd65e85cdef6fdd7fb0a8194257c_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..23eeff5da3caef525e475b001ab0e75ca39702f1
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/69b7bd65e85cdef6fdd7fb0a8194257c_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:6afc9d10ff0f17848567831d101601547ef88d566ad4c284bd55b53fdfbe8cf2
+size 163108
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/69cd894571cdd119f21e31f50b5bc919_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/69cd894571cdd119f21e31f50b5bc919_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..8997f6001550fa049f43403165f28f9af31a36a3
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/69cd894571cdd119f21e31f50b5bc919_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:4c7e48529ed888d90c255442adcd445cbeff651b91dbd3072d69ceb494b94c7e
+size 25972
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/6a2b92323d788c2e7e9e570025885181_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/6a2b92323d788c2e7e9e570025885181_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..d4420de07fd056282c2030a108c188efc760dc29
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/6a2b92323d788c2e7e9e570025885181_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:3adfdadccb8ff6762ae9ca28f1cd8348148e6291effdab2d05120ece3d69a352
+size 27608
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/6ca842602b0473809416a9cf0d4106a4_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/6ca842602b0473809416a9cf0d4106a4_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..d3b9a6f4a4268e4776e500d6d7f150ec83ba1b9a
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/6ca842602b0473809416a9cf0d4106a4_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:9e211fb9f4802355727951d1eff7ba3057063c8560c232d2d675d3861cce6eda
+size 120129
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/6e30434e24bb6d94869199fec410fea4_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/6e30434e24bb6d94869199fec410fea4_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..9e9bc29537f75c5f3eec767e039934bce41685f1
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/6e30434e24bb6d94869199fec410fea4_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:b5a4e551ce675353fd23ebdb9ef90c4be1615a1509c177f7b6cdf4302b99c1ea
+size 128442
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/701f4311e49f346390759520fcd19af4_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/701f4311e49f346390759520fcd19af4_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..23dee451e49511491a5b905fd26cefe13b77ecf9
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/701f4311e49f346390759520fcd19af4_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:437ca6c4c883d555c3860b7ffb7e14a7aa60a5f85aabd3d430f508ee69453470
+size 58593
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/704082cc3e11776bda29595c76411362_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/704082cc3e11776bda29595c76411362_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..22a1a0fe121268241f8de5e30d5cf27ac95a2f34
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/704082cc3e11776bda29595c76411362_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:e018491e7103c1985d733415c338619f9fee1283c06f0d628b060e868c5927b7
+size 32163
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/74fd2e41231630ea45706acca03e46f7_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/74fd2e41231630ea45706acca03e46f7_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..509551472cf0c48980fc2841ded957736d9dd9fb
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/74fd2e41231630ea45706acca03e46f7_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:1b3189763e1e7a1baa46fe0c5c5daccfeccfae69036b9980168cf187c1880b9f
+size 64773
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/75a51aa7d7e96605567cc8bde2ee2999_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/75a51aa7d7e96605567cc8bde2ee2999_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..f0439966a9eef98c7ab07c151bca1c14613e2db8
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/75a51aa7d7e96605567cc8bde2ee2999_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:99bd5e5f9fd3b4363275ecb19ff870b188088fc85ab9a8906a5a488c611c5fb5
+size 93237
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/773bb1698c96c3aea54d138ddcc7cfd5_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/773bb1698c96c3aea54d138ddcc7cfd5_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..3d8d18e779229e7f66405d321ba08dd3bf80bcd1
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/773bb1698c96c3aea54d138ddcc7cfd5_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:7debb5f330fd3430536bd827c871e0fc1ad1bb4f99fed931ffc400d2fd8ffd60
+size 37986
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/7792f9e14df0f92a9eed5c5d61a21eca_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/7792f9e14df0f92a9eed5c5d61a21eca_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..3dcf289b6cab6410409f47ffa9fd430645fcd4bb
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/7792f9e14df0f92a9eed5c5d61a21eca_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:fca4ea3b6e2d0f684366fb34d9268310508022b17f8a727c2ccf4afa380eb819
+size 69208
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/77959075c823bb5169480d7b8ff82a63_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/77959075c823bb5169480d7b8ff82a63_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..af3800adfbdb9c21fa2e4eab7f55e4317ae2358f
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/77959075c823bb5169480d7b8ff82a63_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:ca49333b1d3dc37340bf56426f1f05040b9ca9143a4774f093da348be5b4e14f
+size 75167
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/78aea0de3fc350db7622b6948715b628_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/78aea0de3fc350db7622b6948715b628_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..7b8c53a71e35ee3f6e494cf65a623b2998fcf6c6
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/78aea0de3fc350db7622b6948715b628_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:e8d37e6211d9dcdd614f2ea7050cc45609465b218eacbbfc9769b1b3f85b9786
+size 24479
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/79403f771ea4876ca26ecee2f288b1d1_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/79403f771ea4876ca26ecee2f288b1d1_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..ae281309ee33d0beb256185091ced821bd3a4a7e
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/79403f771ea4876ca26ecee2f288b1d1_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:ded70b469b8cff267a0e415511c286a07239e4bda5ab4c7611746a92a4e4fe2e
+size 82894
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/7a0750f26d97d22b11aca5bbce495726_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/7a0750f26d97d22b11aca5bbce495726_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..e09c666e0818bc56ea0cfc585dcb32b27541cdd4
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/7a0750f26d97d22b11aca5bbce495726_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:a42c4453584a8a127ce5c67b3b69dfc304e49fe039a22bfcbb1a49e54f7f8d7c
+size 41810
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/7ae836e598020d937ed1478c2ef13025_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/7ae836e598020d937ed1478c2ef13025_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..74957e91ccd6438a0c7407f949c2c662dfebc166
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/7ae836e598020d937ed1478c2ef13025_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:affdb5ba0ffdb6882f9769b0377cda46fdb48ba778ef50bc77cb70f80836e95e
+size 114200
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/7c6fd006fc4d304794392d41fab4ee10_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/7c6fd006fc4d304794392d41fab4ee10_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..1eb3519daf541c38beb00014c04c1ded3f5beaed
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/7c6fd006fc4d304794392d41fab4ee10_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:581290af7c2afe7fceba1461bb651a185687aa11880aeb6b095e23fa3aa8ad6c
+size 55630
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/7d1c9af7fe4b35fa7ea5ed76a5f1ceac_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/7d1c9af7fe4b35fa7ea5ed76a5f1ceac_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..a07374037d52ba14f5c12d53a004cf4917e1f7ac
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/7d1c9af7fe4b35fa7ea5ed76a5f1ceac_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:f31356355d93fe07a316e36445c776c63e994b7b2325e516160839fe06ba91ed
+size 21868
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/7e1f88e0cc7be8060240e12252a833d1_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/7e1f88e0cc7be8060240e12252a833d1_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..8eabaa43aaa111c540cffb4c9f101daf406b49d4
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/7e1f88e0cc7be8060240e12252a833d1_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:ad9eb1893612a46552342574a1054afaa08a033823695b53608fd6a4ae0424f7
+size 62762
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/7e5f0aeb4d1adb2bbeed7cdd265a1707_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/7e5f0aeb4d1adb2bbeed7cdd265a1707_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..f79fc293618c52c42795b8bd92fbea32877f0046
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/7e5f0aeb4d1adb2bbeed7cdd265a1707_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:2657bfc06dd7ce66163978877ac67c645f55228cc90e63d84d3ca10f9e3d6d25
+size 97057
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/7f25db95ce3916c0e09803b861a2f7bc_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/7f25db95ce3916c0e09803b861a2f7bc_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..2c57ba89926ac6d5a7c66729890d46874be24471
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/7f25db95ce3916c0e09803b861a2f7bc_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:599a115d1615dc1389cdd60fe4732230367ebbacbe639d7cd7d35078d13655ad
+size 88556
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/812e188283162af0b54fb3e30ffee51b_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/812e188283162af0b54fb3e30ffee51b_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..8d37ace4541f0c7405ee14ffcc525a0ac9cc24e8
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/812e188283162af0b54fb3e30ffee51b_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:191c11827813dfaa7e241bba3d81db84a1eeb4ef397ff8feed644a3eec9b25d6
+size 69249
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/819f1d00e68b342a246b64fa888a97f9_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/819f1d00e68b342a246b64fa888a97f9_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..c3922ad0c325d1c12c6bc3feb3073aba460e5f32
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/819f1d00e68b342a246b64fa888a97f9_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:254572518878686758e38ffbf80ad866ae79ab58371c98d107b06c11450df50b
+size 45944
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/83852ec55d4802521a727926336bedab_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/83852ec55d4802521a727926336bedab_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..07196208f602b9f34fb21f491f22b638dab59d19
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/83852ec55d4802521a727926336bedab_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:57ae51f93147c1b7f0c170af0771d40194dd807094ed81f251939037e7dfdf49
+size 86110
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/845e014e3b8677eb735d0e21f21206be_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/845e014e3b8677eb735d0e21f21206be_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..790d09befd14758fc1e6fe3b72c30a647a2eb972
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/845e014e3b8677eb735d0e21f21206be_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:4a312d9326d02dcf985432a0b6c941e7119cddd68af5e25f0d77493a5d17e4c9
+size 82004
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/86ac58f5114fa0d6d76c1a81e4aeda21_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/86ac58f5114fa0d6d76c1a81e4aeda21_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..4941c261fd0e18e7cd51ef7b0f72ec9f847b8b4c
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/86ac58f5114fa0d6d76c1a81e4aeda21_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:1fdb9cebb99f25b313ce1d8f27ad01d8f7e81cb67cedb955919d272e2b7246cd
+size 26758
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/86c74ee06f834f849f6cd094ca0b5867_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/86c74ee06f834f849f6cd094ca0b5867_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..a5f98f9565a5f2a00c79c6511b7859b2500e96a9
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/86c74ee06f834f849f6cd094ca0b5867_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:dbef54909627cda54ec086700c40874c4ab7a49489b0eacd19457de6fb5a0e9e
+size 115372
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/87f8b579bc67022e8dd0a0a50585fd4d_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/87f8b579bc67022e8dd0a0a50585fd4d_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..9949745708a31603474aa6e9b7c197125ee4af55
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/87f8b579bc67022e8dd0a0a50585fd4d_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:362ff4341db65167eaf5d529064fa12de80d7c40e552d5e7bd19b6338bf5a828
+size 95713
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/8966721dc9e71a11b8af6a278b37301b_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/8966721dc9e71a11b8af6a278b37301b_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..7e04be818d2b34145b0466b76efc9c116e04d02e
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/8966721dc9e71a11b8af6a278b37301b_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:f6f5888fc097eecedcbb2fbc007ce0746d5849bd21ba976f9cecd2278c823250
+size 7483
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/8c126c290eea7c5d7807a293fd40f2d9_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/8c126c290eea7c5d7807a293fd40f2d9_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..648d8d49dd4752b597944dad18d7bfe7c557c818
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/8c126c290eea7c5d7807a293fd40f2d9_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:0ebf811cc96e52277a3721e237d8f69771e9a96738bf66dd9f7a97adb6729eb0
+size 85005
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/8c348bf9c2c81b018017ae1d19506a9a_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/8c348bf9c2c81b018017ae1d19506a9a_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..d887daabfe89acd71bc20fd65652676e0a16b836
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/8c348bf9c2c81b018017ae1d19506a9a_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:4e48c3ec4d716e0db8b1d673b66736825689f23338f0ab331d3ec37e5a06627a
+size 165747
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/909726977de6efd2d4df015198a2907b_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/909726977de6efd2d4df015198a2907b_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..4f2eb224c70f87158bab9dcbc9257e183e0bb804
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/909726977de6efd2d4df015198a2907b_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:8bea03493b21aa53f86e65986d1dfd7d581e9b4c806bc1fa68f2b16ebd7fd4dc
+size 56408
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/91f404ac02e6fa9439a7f5cc7af0e2bb_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/91f404ac02e6fa9439a7f5cc7af0e2bb_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..fda657679c847fde98bc70838505b642d459e1b0
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/91f404ac02e6fa9439a7f5cc7af0e2bb_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:4415189886e97b5d106260241e783b60a819bcacdd313328efa818c5bdf39cbb
+size 114619
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/92c9263daf7fbd044894e2b273ae21af_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/92c9263daf7fbd044894e2b273ae21af_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..3c7d8464fa92922d3d3656287b14e094995605e9
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/92c9263daf7fbd044894e2b273ae21af_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:883a38506ae51bfecc820f5f0b906bc5ce759e36bbf1d92e2c5b26e05775a23c
+size 130833
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/92e26d86c5a582766cb9afdbd2c1aee7_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/92e26d86c5a582766cb9afdbd2c1aee7_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..185359d01f622d57c7a2771196aefdf9e3d06dbd
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/92e26d86c5a582766cb9afdbd2c1aee7_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:d7c6de79ba5a29760aa751ccf1d47c071a983f3598dfef828247b8a0e6ff15ce
+size 41803
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/98e54d5540b2efe3e24af3cf936bc4ea_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/98e54d5540b2efe3e24af3cf936bc4ea_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..b09cd2d676012e397e4a5f0dd9bb4a4bca3257a0
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/98e54d5540b2efe3e24af3cf936bc4ea_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:4d3b7e285e1a451ac7554591ca2c5266860f66f987b842a07c182cfc31b69848
+size 130917
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/9a5927586a691c4908aa2cf98bd47ebb_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/9a5927586a691c4908aa2cf98bd47ebb_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..fb6e892fd9c88309cf7804bba8718d3143d7bf2c
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/9a5927586a691c4908aa2cf98bd47ebb_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:db62d836388e93f052fd8e7825d810064a28ee2dcdfd9880d85a43fffa67e52a
+size 79580
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/9b6977f95ef47e2c87cd4979c09a7edb_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/9b6977f95ef47e2c87cd4979c09a7edb_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..b2590a5a51f37a971d8da6482c30f1ea7f009cf4
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/9b6977f95ef47e2c87cd4979c09a7edb_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:3dd15066aadf30baee65affea99a2b8faa1f27b56839a6b71794b2107c7707f9
+size 85706
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/a37adbbe12ec735a20ead2466363d07a_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/a37adbbe12ec735a20ead2466363d07a_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..426f3b4c6fc46ae7f3182979d4152e02ea7ed72e
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/a37adbbe12ec735a20ead2466363d07a_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:e81900ef47daf3aafe2f347d326153b94bef810da7ecd2d94d70065876e2f819
+size 45063
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/a3f7894bf388f7bbbde87323c46760df_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/a3f7894bf388f7bbbde87323c46760df_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..6ecb70079fc7e75d353e37e76dac968a41898ff6
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/a3f7894bf388f7bbbde87323c46760df_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:53faa929a48f7ad93b8b625254f8e71f53c187d16d8f515e83a036befbc6145d
+size 39315
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/a44551dad21acf5d915934680da21740_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/a44551dad21acf5d915934680da21740_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..99a4fd80743a60900e6717cd2b96ccae1949b7a0
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/a44551dad21acf5d915934680da21740_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:9e702ed8540152a6135f8f1f2d9c7c08a272eddff69aaa415109c2410fe06bc0
+size 122985
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/a470a6ac2c62c28490aa633071c565a9_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/a470a6ac2c62c28490aa633071c565a9_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..04fccb1ac1454b540ff7f713de756ca64a9f1348
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/a470a6ac2c62c28490aa633071c565a9_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:b25dcc4d7605eea7bc692895d7e6a7f06fc6f7c72831039a828bd69ac9dab7ef
+size 71245
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/a48ecbf3100ebf31b5d615267fa263c3_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/a48ecbf3100ebf31b5d615267fa263c3_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..1865f77ec3771c719298056e0d93f64df7272883
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/a48ecbf3100ebf31b5d615267fa263c3_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:43638b8afd5f80067c93a4b2577fa2cb04b558ccbf817478d92b2f975e8a13e7
+size 24448
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/a76fa39f5daf6a026e032495262ed0f6_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/a76fa39f5daf6a026e032495262ed0f6_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..ae1aebceac8d0818e10f5357f953411983173c18
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/a76fa39f5daf6a026e032495262ed0f6_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:0758088027158779ca67483bbd97632b0c340e9ac49d3d677cfe20878ee7152d
+size 70559
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/add5c678c1d8eedc51d3e8f86ca21e3a_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/add5c678c1d8eedc51d3e8f86ca21e3a_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..1805bb61da0061942bd3e7e13a709eb67235077f
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/add5c678c1d8eedc51d3e8f86ca21e3a_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:3479346520d511a1d0224a9eda2692fbe4e41253ecc4467f28c02eca59bdf540
+size 130908
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/af3b2fa532cb9b02a2aaeeb49e0118d0_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/af3b2fa532cb9b02a2aaeeb49e0118d0_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..f76f79ba0193a9502f27bc8c400f368d35c4402d
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/af3b2fa532cb9b02a2aaeeb49e0118d0_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:f945ea937f9b81c1ddf8cf12bdd86e5e29be3926c25e8222c3a80029bfd1cdc0
+size 53640
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/b1ec498620251169dcfc839e18443154_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/b1ec498620251169dcfc839e18443154_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..33ec40a5356c6529a2f4d02aaa902512a8134f53
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/b1ec498620251169dcfc839e18443154_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:b9f889ce11a088fef117ff0195a48d2fabfe7aaaf815f7657b74a53113b16b91
+size 49141
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/b3335932702b8668e62791e9fd12c9ff_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/b3335932702b8668e62791e9fd12c9ff_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..bc82dc120050ed906736a39110352ae9023c7f24
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/b3335932702b8668e62791e9fd12c9ff_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:d35cb4b7e2e29e25e8a62c4a213ca32a5ac9ceace8d85f53180ad8f4d3ca371b
+size 25341
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/b46063d0aa9f16339e823bd0179e22e3_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/b46063d0aa9f16339e823bd0179e22e3_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..bd711468d58051c627e2ddbe2a88e64414cfb51f
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/b46063d0aa9f16339e823bd0179e22e3_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:668c3323c3b83ec83f7551a98470ac83719db9a8834343940777f4d794b38b77
+size 28788
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/b5057d14125b4990fdeb226f025d5bf5_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/b5057d14125b4990fdeb226f025d5bf5_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..69560dfadafabd6d07ff87614f13aba2065843ad
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/b5057d14125b4990fdeb226f025d5bf5_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:9dafe700ac6ffb5b5cedc5e095882aebc3cfc035ee6bbaead8ee7da157785489
+size 37718
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/b6f6f51bf96aef85ffe1dcd9d57f398b_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/b6f6f51bf96aef85ffe1dcd9d57f398b_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..4dcf5d4092216cb2749628dd507f4f4be4ecada2
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/b6f6f51bf96aef85ffe1dcd9d57f398b_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:d0ed5ccfc6fb62795bb693cc5f82bbb7d2570a5d7d4b1ed24cc4db11255dbd0a
+size 65720
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/b99ddca16383b6f00fc70050d695a235_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/b99ddca16383b6f00fc70050d695a235_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..2eee2114ceda8d59921b70785549edd5b74569ed
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/b99ddca16383b6f00fc70050d695a235_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:e7bdd614236346e824eca47d84a9f1d99cba5e81f6921c1d2bee379f684cc017
+size 39689
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/ba02765d3e16e98d341f563cb74e8716_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/ba02765d3e16e98d341f563cb74e8716_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..b4cce52eef6320a802eaaa2b38b5cf828649f6b5
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/ba02765d3e16e98d341f563cb74e8716_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:723e76927f89d59671d1c2972486f58c9340cdca71bc27fa13f430b0c6092b88
+size 123774
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/baf8e707713cfcf1fd4e6aa38dd94597_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/baf8e707713cfcf1fd4e6aa38dd94597_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..2e9af621cb544599ceb11d39757d6fdfd75bcf04
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/baf8e707713cfcf1fd4e6aa38dd94597_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:14b4ee6ef3b99d53e8802db3e02fada770aafabd0e43912a30a6969f62eaac92
+size 120895
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/bb4d2112ed07e2031c92fbff3494af9f_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/bb4d2112ed07e2031c92fbff3494af9f_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..6ccd63a15fe42eeeb6a5675eec16ad72a48355e8
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/bb4d2112ed07e2031c92fbff3494af9f_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:b5220956019b24de7083d09de2fea1c4b26f5d187d784edfc9f883324a083e87
+size 128661
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/bb8035cd106b4d77b3615e90645f8e37_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/bb8035cd106b4d77b3615e90645f8e37_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..3f16ee48eede3aef28127b81c8525f4b194ab882
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/bb8035cd106b4d77b3615e90645f8e37_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:13d68d07fd81cf9c4d3d65bc188252a6e340b8f5ffec565e076463474426935a
+size 67382
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/bbdb91b475e5915fd7e690eea9e6220b_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/bbdb91b475e5915fd7e690eea9e6220b_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..b3c6c25341be93c5c052274181ccb0bf7421b025
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/bbdb91b475e5915fd7e690eea9e6220b_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:a1628d646c6435fe8792fe4b72de0d407dcfc8629274a81fa484b6042d37cb98
+size 47332
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/bbde47e1cdb21db57ec50c7436fb547d_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/bbde47e1cdb21db57ec50c7436fb547d_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..f2b3b13bd73fd48dd3ff93ac8a48b89177f8d512
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/bbde47e1cdb21db57ec50c7436fb547d_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:a9bf216bba86db304e2da20de8eb726949b2ef6b687bdb5b3dac26b11066ab46
+size 52034
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/bbf92fa724597efff9a7b4625ec54041_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/bbf92fa724597efff9a7b4625ec54041_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..c8e73fe8e25e70d63648d3c5e880ce838950c727
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/bbf92fa724597efff9a7b4625ec54041_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:570574b983e6f1922343c867d3555cd513c0827c1dbeef3a1c5b39ef0582b58b
+size 76376
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/bdee2715697a4142d16a360549fa7c7f_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/bdee2715697a4142d16a360549fa7c7f_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..5a9a225463ca9e2dbe45afd78d98945032a94fce
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/bdee2715697a4142d16a360549fa7c7f_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:f5dc9da3def959f9c5420d6b4cc3f9f6989b7fc00319dd5acc62bfd0592dc965
+size 119304
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/beda549cc2a4e2b9ac7f74fe9ed72b67_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/beda549cc2a4e2b9ac7f74fe9ed72b67_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..2fca71f66100f98edc1b4bb3b11553971fca19f8
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/beda549cc2a4e2b9ac7f74fe9ed72b67_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:09270dd6f1b6edb3744123d4ee57d916af27bce8e606a1029cf0a792bd4bce77
+size 70904
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/bef134816f55f50b735c92ac0c01da38_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/bef134816f55f50b735c92ac0c01da38_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..cccc949105eaaaf3def4db9f1884c2d0509e9897
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/bef134816f55f50b735c92ac0c01da38_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:5a3221aee04020ddb5b1c5d63c3ee33d64adb5db831a887bcc84036edf5b9fbe
+size 75797
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/c1df61cc3717e878a48e530218403403_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/c1df61cc3717e878a48e530218403403_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..aa67eed3f8d559331b21536b74a96d3ee7adc553
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/c1df61cc3717e878a48e530218403403_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:5211bde6bb39a475967d3eb2832673ba2085b4b98436b848825ae2f791300356
+size 2867
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/c21bad844b5cb6026c067a1f43ce67c3_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/c21bad844b5cb6026c067a1f43ce67c3_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..c07c1f6949a9bb7cf92168f5f218b2e689476224
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/c21bad844b5cb6026c067a1f43ce67c3_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:3be5a95ad3f863205610b602e4384ae201506e2563e598ddab98a79640522410
+size 33381
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/c2dbaf7c88ad38cb8620f6d731935ed8_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/c2dbaf7c88ad38cb8620f6d731935ed8_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..045c6a55522394577286062fd2d79a222f72afe0
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/c2dbaf7c88ad38cb8620f6d731935ed8_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:ce20525d2da05812b88fab412ad6af25cb16e56d7a3beb2e9fdf8102fd54bbdd
+size 28040
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/c355b8056bdd4728357d7d5ed18792ca_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/c355b8056bdd4728357d7d5ed18792ca_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..b1261743da3cbc1ff27c43709d04b6344d11321a
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/c355b8056bdd4728357d7d5ed18792ca_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:89e00ed41fe7b4d4ecc9dd0e2e62a5c69d4b8a4f569bf98cd44c9925f4cff07e
+size 124421
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/c5452f95f3b28f1bfe29e84fbc2e1267_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/c5452f95f3b28f1bfe29e84fbc2e1267_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..77ca95d5deffdc9f5c123b9f2b1eeb8fac3753e3
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/c5452f95f3b28f1bfe29e84fbc2e1267_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:ef0e9bcb2d33868d1c6aa806e689fdf4c1bc5737439df7b87adaea6103424de3
+size 40602
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/c6240283e2f65a6d02db47fa4ab0c518_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/c6240283e2f65a6d02db47fa4ab0c518_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..683084c3cc9e3a321d1a59081510d08d33f7d8ae
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/c6240283e2f65a6d02db47fa4ab0c518_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:1c303230188f95c840c82f921a250bd2b34c741e5ad6f63ef5ec5e31129240e1
+size 45775
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/c700124873e73d0731c82ef7e12b71f4_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/c700124873e73d0731c82ef7e12b71f4_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..bb4ceeb3afc293736f5aa85fb5f59770d131e7df
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/c700124873e73d0731c82ef7e12b71f4_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:a0ffb54f71244a99b926a541780444d1bb334d84bd77c5ccd1c62451348130b9
+size 137873
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/c916a9fb4d2c440522379dedf3f76119_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/c916a9fb4d2c440522379dedf3f76119_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..29f86f59505ffd28c70eb6dc7f4a5055dac96193
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/c916a9fb4d2c440522379dedf3f76119_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:e1460155aa87d374ca7ef03580790e112215018cbb70d5dea5fc4088cd1907e7
+size 94130
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/ca86f53f9735fe98b6c6003d1b759f64_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/ca86f53f9735fe98b6c6003d1b759f64_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..5b611143903850e7ba9b74db5e585d0bbe2f8396
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/ca86f53f9735fe98b6c6003d1b759f64_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:4b7e439fa462175c82844b12552c20f94090deaead47c446de777eeacfb808e3
+size 37731
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/cb74fd9f5ec715dd3e2e325b864b48bc_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/cb74fd9f5ec715dd3e2e325b864b48bc_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..d14ce7d447e22fc8fa61a82ba2dd70af4de94f47
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/cb74fd9f5ec715dd3e2e325b864b48bc_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:69ac89dbd72237ae4ba16a48b9c60df45e2527b5568ca7af0490b3e37b145587
+size 9090
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/cbb2d311b20781a595488445ded48d0a_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/cbb2d311b20781a595488445ded48d0a_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..91497b5c66f2b9fe33a1454323b1b6933a866338
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/cbb2d311b20781a595488445ded48d0a_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:ac762fb2229924236ad8d9438fedbd85dc79cf6bec92ba4d14770e6f75c2548a
+size 119177
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/cc91bf9aed46f8b219ebceaee276d195_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/cc91bf9aed46f8b219ebceaee276d195_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..d1dec4e752751533cb2723bcc4ee56f9c0f63591
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/cc91bf9aed46f8b219ebceaee276d195_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:4fa8b6b6e12b89df302fcd4f30c7b456cf152430952c26dc6884841151b5983e
+size 78676
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/d4e22bbe01024f0a4981d41da11252a9_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/d4e22bbe01024f0a4981d41da11252a9_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..2de2dcdd0d7e32a4e53abf45017de62a5e4da915
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/d4e22bbe01024f0a4981d41da11252a9_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:5dd10cc1a304eb9228c69984b424597043f51758b59fe455fb0b4d92756e6020
+size 60740
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/d5e2d0294025e6c1a539b51cb92b58b3_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/d5e2d0294025e6c1a539b51cb92b58b3_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..510a72a7309df0e3487f574fff4c84ce97741a22
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/d5e2d0294025e6c1a539b51cb92b58b3_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:faba333d0b459bc21d35926ac97442ad7436363ec7560acae426cdede29a150c
+size 62324
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/d7896dd2d38adf224c3b76cd22d29c10_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/d7896dd2d38adf224c3b76cd22d29c10_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..0c8369fe43d349619d3ee2701a6237c555658a2f
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/d7896dd2d38adf224c3b76cd22d29c10_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:7f3cb1fd4887eb1f09d11a24453457d5772e4a2d27cf986f005bd8ff42b4d9f1
+size 66098
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/d884367c84ba50f250499f79c4b4b950_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/d884367c84ba50f250499f79c4b4b950_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..a15f10942f74e4fc423184f302938f11097dc5f0
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/d884367c84ba50f250499f79c4b4b950_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:35dd49f26aafea26f0e6b93e0865a93c44b32d7f8a5c55e38908f7db7486b33d
+size 18552
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/dbd074feb5cce1300f42f91da8f673d1_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/dbd074feb5cce1300f42f91da8f673d1_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..ec40abc73bca2a2e7063f90e234e58c7fb0eb75d
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/dbd074feb5cce1300f42f91da8f673d1_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:d5fef1565689317da34acda6dcc1760faefa442174d747a3204b5188e9e8bd32
+size 135918
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/dc7f3c8b7f8859a78d5705f104504e4c_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/dc7f3c8b7f8859a78d5705f104504e4c_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..582408107c22fd9e0183ac2498638ad38cdfe4c8
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/dc7f3c8b7f8859a78d5705f104504e4c_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:9e7cc013a12cfd1d34e7aa524e25aa27fdc3a4eb009e489b33a6fcb13f4a9148
+size 75442
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/e3eebf9854831ba50eca8b26c468f65e_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/e3eebf9854831ba50eca8b26c468f65e_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..ae9763d21535f64ec7a2f3788e540b6f41734a43
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/e3eebf9854831ba50eca8b26c468f65e_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:88ed233e7df5977cc5dcdb41b2168f568f5e4355d0e335be3b318a40d8249cb1
+size 63972
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/e451401f8fa77b466f401d5fce15b26c_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/e451401f8fa77b466f401d5fce15b26c_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..fd36b5ee32af7ccebf38fcdf4d5e30de6a1ccd8d
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/e451401f8fa77b466f401d5fce15b26c_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:9e27e3f42f8f04af4266307d2893317ee6c7b39317ab958d7135ad0a8d9105f6
+size 121655
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/e47d450f315d0b633906c03cc91f90ef_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/e47d450f315d0b633906c03cc91f90ef_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..ba118fd163d5d597aa4380073c5cdad7ae6eb929
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/e47d450f315d0b633906c03cc91f90ef_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:79401d7faf04c8f2991d7100ff897847fdcc762f855c8417f820724a67ba2e8f
+size 40430
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/e492fe1061d82aa76cbf7114f57eb90c_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/e492fe1061d82aa76cbf7114f57eb90c_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..666a26d58bf2a7466817c25d9ef7b5eef2640fae
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/e492fe1061d82aa76cbf7114f57eb90c_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:af26816d63c8723922cd2852d7198d65d0c5d949d2f171e2f8c0494de6101509
+size 94628
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/e5eedb1e90a22814f090917b3411be8f_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/e5eedb1e90a22814f090917b3411be8f_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..86f147a2405f175854f3ee55ea7e89a4f9ca2616
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/e5eedb1e90a22814f090917b3411be8f_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:443826abadbdaf3098d9fc06a869d0cc2a26534f74da9786ce3d5ba4d379b182
+size 69430
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/e64c7b989e5bdb2708cd7aefd18b06e1_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/e64c7b989e5bdb2708cd7aefd18b06e1_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..0213f2d842b021a93330d94a845d7b444ee99754
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/e64c7b989e5bdb2708cd7aefd18b06e1_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:5fa2027beeb0616851d46484de3b04e5c0c7c08f9c1794cb291879851e09c852
+size 67508
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/e7b22e97c8d8064fe5f7cdfc4f2a5371_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/e7b22e97c8d8064fe5f7cdfc4f2a5371_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..2c87f26bc974d596e59dfb167f81c51254740732
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/e7b22e97c8d8064fe5f7cdfc4f2a5371_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:5309e37b5d1f883549a2b889b5b9e118c19d122a1e1c70db3408b295fc4b2415
+size 69669
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/e817de1b2f803560e39d541c3966532b_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/e817de1b2f803560e39d541c3966532b_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..07bb92fa0de1597b718f3f4fb0dbc9feefe7c95a
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/e817de1b2f803560e39d541c3966532b_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:ac12f64e2b5b1e13b96dc66edf45048bd12efba11951c71d00eee4ad2e82d545
+size 71974
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/e8681a7c5b90ebe66b2ea31d561cf697_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/e8681a7c5b90ebe66b2ea31d561cf697_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..23d5b5eb194047517c4619b70875cd33c6a16837
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/e8681a7c5b90ebe66b2ea31d561cf697_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:fc58def8c78c6a0ced1a6fdc856d1ace8808cb5e947fb26b3e12de6216bab48d
+size 76675
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/e8ba5d4a3a22e24e44f7935ea26afcb0_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/e8ba5d4a3a22e24e44f7935ea26afcb0_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..36cf51f8ba07e44aa7a4b009f3ba08eb2b570b1c
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/e8ba5d4a3a22e24e44f7935ea26afcb0_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:11780faeee75ba39ab4ed9de67a9e67abec0d9ba3068ebec661dea70c16e29d3
+size 4338
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/e8e818455bb0d1a6153299a388b94868_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/e8e818455bb0d1a6153299a388b94868_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..c21387e17365ed11f00ac2b202c050b2f7067bce
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/e8e818455bb0d1a6153299a388b94868_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:789cb9584191a9f8353dd3845932c9e653486c01fa3e02427c779f46588907fd
+size 30527
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/eb115632012e88aba296fed016baad57_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/eb115632012e88aba296fed016baad57_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..69dc7401c93a20529780bd31835d64c6a2a0541f
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/eb115632012e88aba296fed016baad57_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:ec77ac0eeef8028bf5183367bac2982051ec56b53ed5c6fd1c91531ebd43c5ca
+size 24872
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/eccb7897052cefaeededf354d23bdbce_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/eccb7897052cefaeededf354d23bdbce_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..2d0b95ef5ff5110070ce5d9b0f0152e1413d9237
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/eccb7897052cefaeededf354d23bdbce_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:c7112dfcc24fe9897d2b77abafddb7d3db5be1c585e9db0cef3c31b32b7b96f6
+size 29826
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/eda1a0f033926f48febc095bce470c58_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/eda1a0f033926f48febc095bce470c58_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..c2e3c655841613e836b29284f012e4e822938977
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/eda1a0f033926f48febc095bce470c58_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:dea6008fc8cf2151b86a743dfcb361c8b20003d251a0bebb662db33f96916285
+size 109305
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/f117583d264d1fa4b9c67c44879bb3e7_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/f117583d264d1fa4b9c67c44879bb3e7_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..4fb6d2a261cd0cf3e9d484695d089db0d4334c82
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/f117583d264d1fa4b9c67c44879bb3e7_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:3ce4637906d436c7252f5f8b4c27ba0df825f685f698bc312744f3805b86c295
+size 124575
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/f2b561f8d2d2b8402379552179d9fbef_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/f2b561f8d2d2b8402379552179d9fbef_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..b48e696dec5d2885cb1006bbb5e3800981ffa8ab
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/f2b561f8d2d2b8402379552179d9fbef_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:28fe71c4ba066bd6a5ec94ef2a53ea3f14a112aa2f63f2838e99f6f285466351
+size 135194
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/f3f568cc57088117f1c4589f174d3dbf_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/f3f568cc57088117f1c4589f174d3dbf_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..54514619628e2fa49dab857eac07b324e2f63399
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/f3f568cc57088117f1c4589f174d3dbf_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:3ae7b3b46e382c5b845433ee665ff075b3dea88904c02ddda40ffc8040941881
+size 37698
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/f57c7b37d7a05a99618104f390089f03_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/f57c7b37d7a05a99618104f390089f03_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..995ee400163a1effe91a6ae6a1668e2c32405ffd
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/f57c7b37d7a05a99618104f390089f03_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:fa83f18f94736074d528546bf23a14afa3fe974235c85bd24aa4515bf77b9f82
+size 37613
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/f79479a95458154a50c70d85622714ea_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/f79479a95458154a50c70d85622714ea_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..70c28727a4527fff63b32cead9cd8fb918e32b93
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/f79479a95458154a50c70d85622714ea_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:4b8a27ab19db5b83c7842c9f48cf7fb80ce3ab581d057c4c582367a335039e0c
+size 131080
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/f7b8e904ed324350738ba643e3273572_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/f7b8e904ed324350738ba643e3273572_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..7bc8b3f12b7912b31d557fe8ee68482f88db5688
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/f7b8e904ed324350738ba643e3273572_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:fd67143f218a794ce876330168dece5d1100fdae13f7791852a2cb904041718d
+size 88048
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/f803be090d37a5189dbc87c1c87b6c63_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/f803be090d37a5189dbc87c1c87b6c63_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..ac50910c259a03b92f25787803bd615f5b8f48a9
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/f803be090d37a5189dbc87c1c87b6c63_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:b5a2020da338178cc7b55d6bb345d3b0e106c857aa31354c666860d045df3598
+size 48485
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/f814714d4415807ccec0645e664397e6_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/f814714d4415807ccec0645e664397e6_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..6eaf7cb2338dde550fb05ad7784db892e39e231b
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/f814714d4415807ccec0645e664397e6_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:8503a29267baa9b2feff0e5681c7d431a6008bb03834c4b4597fd798411b1124
+size 87304
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/f905876e79e35f5de8372c4945a27c50_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/f905876e79e35f5de8372c4945a27c50_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..cf0754a7ab5639f3d55135370e9d8ca19a088dc9
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/f905876e79e35f5de8372c4945a27c50_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:645cdb1631207d63b42577332ace431b413a1d29835cc1bce1f33df0b95a3e5c
+size 97224
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/f912dca77834dec85a50503dea8c99be_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/f912dca77834dec85a50503dea8c99be_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..50987d0d6f135b57fce2dac5edd4e3e8cea9bd05
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/f912dca77834dec85a50503dea8c99be_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:e6bda163cc2f274307df8f4d10a7631f7a50559dd6c2f1b9f7e4c7dde9e23a96
+size 48037
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/f9c64800d9bace9b4315646d1057be3c_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/f9c64800d9bace9b4315646d1057be3c_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..7212e497e007a5c7466c8d4988e6c58b9a70de68
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/f9c64800d9bace9b4315646d1057be3c_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:b79c3dd38f06837b01b9aa4f809b245d1f8829e47c3620c5f2dddfb784d710d7
+size 117648
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/fb4503cfc4abdcdf439a898cde5bab68_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/fb4503cfc4abdcdf439a898cde5bab68_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..920b59b7ff380ab229cec8364510e9cfc5d05be1
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/fb4503cfc4abdcdf439a898cde5bab68_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:1aa67ff4ee730dfd216f2f727e1df66dd6628b2f98928ea20d16583f922b37b2
+size 13628
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/ff7ce44f3fdd51bae7b231f34df07c6a_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/ff7ce44f3fdd51bae7b231f34df07c6a_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..4249fafaa63238dd47b4577c5f1001bdfbe4dfc1
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/ff7ce44f3fdd51bae7b231f34df07c6a_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:aeca886c43950097408c63a92254022bbb914ec1e5ec0eddb952ed7031084b3b
+size 73732
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/ff86a9199e2ee52e0a198605699d277d_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/ff86a9199e2ee52e0a198605699d277d_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..fc1acb059257ebd06b37bfab6bde92896222266a
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/ff86a9199e2ee52e0a198605699d277d_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:badf5466a1020ea0c7a64c413da91dcef43c7eb86137a82631be6f9866b85700
+size 87886
diff --git a/marked/T/T-REC-T.30-200509-I_PDF-E/ffe88a9bb668f71402c41928110ce08b_img.jpg b/marked/T/T-REC-T.30-200509-I_PDF-E/ffe88a9bb668f71402c41928110ce08b_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..57bdd14119fdaec3bc02d556589f8b7416bd7c9d
--- /dev/null
+++ b/marked/T/T-REC-T.30-200509-I_PDF-E/ffe88a9bb668f71402c41928110ce08b_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:db8fff93ba2d05f7a1a5b9d3517b0ce75970b1ef822d1d80691ccfa8a54a9911
+size 39886
diff --git a/marked/T/T-REC-T.31-199508-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/T/T-REC-T.31-199508-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..d583707f19a457fe8e134f2d2deb6f735f3ca9ef
--- /dev/null
+++ b/marked/T/T-REC-T.31-199508-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:2eeb0a4a477a2bb88f1f7e6a009f9c1727919f0c2913331cfdb5766ea903d8f7
+size 8321
diff --git a/marked/T/T-REC-T.31-199508-I_PDF-E/raw.md b/marked/T/T-REC-T.31-199508-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..094043a831bb0e9bec9246f8d3836f8265b757df
--- /dev/null
+++ b/marked/T/T-REC-T.31-199508-I_PDF-E/raw.md
@@ -0,0 +1,891 @@
+
+
+![ITU logo: a globe with the letters ITU inside, and a lightning bolt symbol.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg)
+
+ITU logo: a globe with the letters ITU inside, and a lightning bolt symbol.
+
+INTERNATIONAL TELECOMMUNICATION UNION
+
+# ITU-T
+
+TELECOMMUNICATION  
+STANDARDIZATION SECTOR  
+OF ITU
+
+## T.31
+
+(08/95)
+
+# TERMINALS FOR TELEMATIC SERVICES ---
+
+# ASYNCHRONOUS FACSIMILE DCE CONTROL – SERVICE CLASS 1
+
+## ITU-T Recommendation T.31
+
+(Previously “CCITT Recommendation”)
+
+---
+
+# FOREWORD
+
+The ITU-T (Telecommunication Standardization Sector) is a permanent organ of the International Telecommunication Union (ITU). The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis.
+
+The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics.
+
+The approval of Recommendations by the Members of the ITU-T is covered by the procedure laid down in WTSC Resolution No. 1 (Helsinki, March 1-12, 1993).
+
+ITU-T Recommendation T.31 was prepared by ITU-T Study Group 8 (1993-1996) and was approved under the WTSC Resolution No. 1 procedure on the 11th of August 1995.
+
+## --- NOTE
+
+In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+© ITU 1995
+
+All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU.
+
+# CONTENTS
+
+|                                                                           | <i>Page</i> |
+|---------------------------------------------------------------------------|-------------|
+| 1 Introduction and scope .....                                            | 1           |
+| 1.1 Facsimile terminals .....                                             | 1           |
+| 1.2 Facsimile DCE .....                                                   | 1           |
+| 1.3 Scope .....                                                           | 1           |
+| 1.4 Overview .....                                                        | 1           |
+| 2 Normative references .....                                              | 2           |
+| 3 Definitions .....                                                       | 3           |
+| 4 Abbreviations .....                                                     | 3           |
+| 5 Facsimile DTE–DCE interchange circuits .....                            | 3           |
+| 5.1 DTE–DCE communication link data rates .....                           | 4           |
+| 5.2 Asynchronous to synchronous conversion .....                          | 4           |
+| 5.3 Flow control .....                                                    | 4           |
+| 5.4 Serial data interchange circuits .....                                | 4           |
+| 6 Autodialler services .....                                              | 5           |
+| 6.1 Command syntax .....                                                  | 5           |
+| 6.2 Command execution .....                                               | 6           |
+| 6.3 Response syntax .....                                                 | 6           |
+| 6.4 Capabilities identification and control .....                         | 6           |
+| 6.5 Call answering .....                                                  | 7           |
+| 6.6 Call origination .....                                                | 7           |
+| 6.7 Call termination .....                                                | 7           |
+| 6.8 Result codes .....                                                    | 7           |
+| 6.9 Serial port flow control .....                                        | 8           |
+| 6.10 Serial port speed control .....                                      | 8           |
+| 6.11 Transparent data commands .....                                      | 8           |
+| 7 Facsimile Service Class 1 .....                                         | 9           |
+| 7.1 Connection establishment .....                                        | 9           |
+| 7.2 Waiting and silence detection .....                                   | 10          |
+| 7.3 Data transfer .....                                                   | 10          |
+| 7.4 HDLC framing, transparency, and error detection .....                 | 10          |
+| 7.5 Facsimile carrier error message response .....                        | 10          |
+| 8 Service Class 1 commands and responses .....                            | 10          |
+| 8.1 Command summary .....                                                 | 11          |
+| 8.2 Capabilities identification and control .....                         | 12          |
+| 8.3 Service Class 1 action commands .....                                 | 13          |
+| 8.4 Service Class 1 result codes .....                                    | 15          |
+| 8.5 Service Class 1 parameters .....                                      | 16          |
+| Annex A – Interworking with existing facsimile DTE .....                  | 18          |
+| Appendix I – Service Class 1 example sessions .....                       | 20          |
+| I.1 Calling sequence, transmitting a single page facsimile .....          | 20          |
+| I.2 Answering and receiving a single page facsimile .....                 | 21          |
+| Appendix II – Recommendations for DTE compatibility .....                 | 23          |
+| II.1 Clarification of switching from HDLC reception to transmission ..... | 23          |
+| II.2 Clarification of switching transmit modulation schemes .....         | 23          |
+
+# **SUMMARY**
+
+A Group 3 Facsimile Terminal may include a DTE and a Facsimile DCE. This Recommendation describes a Facsimile DCE that includes physical and data layer functions. The corresponding DTE must implement the T.30 session protocol, and any necessary higher layer functions, such as Recommendations T.4, T.6 or T.434.
+
+## **KEYWORDS**
+
+Class 1; DCE; Group 3 Facsimile; Modem; Programmable Communications Interface.
+
+## **ASYNCHRONOUS FACSIMILE DCE CONTROL – SERVICE CLASS 1**
+
+*(Geneva, 1995)*
+
+# **1 Introduction and scope**
+
+## **1.1 Facsimile terminals**
+
+Group 3 facsimile machines were developed for sending digitized documents over the General Switched Telephone Network (GSTN). These facsimile terminals are now in widespread use around the world.
+
+The operation of Group 3 facsimile terminals has been standardized in Recommendations T.4, T.6 and T.30.
+
+## **1.2 Facsimile DCE**
+
+There are two types of adapters which allow Data Terminal Equipment (DTE) to communicate as Group 3 facsimile terminals. Some of these adapters are installed inside the DTE, on the processor bus; these are called “FAX boards”. Others are configured as an external “facsimile DCE”, connected to the DTE by a standard serial port (e.g. Recommendation V.24), using serial data interchange, as defined in Recommendation V.4.
+
+## **1.3 Scope**
+
+This Recommendation contains protocols for use between a DTE and a Facsimile DCE. It includes automatic calling and answering.
+
+This Recommendation defines the commands that the DTE may issue to configure and control the DCE, and the responses the facsimile DCE may issue to those commands.
+
+This Recommendation is useful for intelligent DTEs and DTE software, facsimile DCEs, and facsimile terminals with digital connection to DTEs.
+
+This Recommendation assumes that the DTE and DCE are connected via serial asynchronous connection using V.24 circuits. However, the protocols defined may be implemented in any environment that provide a character serial bidirectional data stream, including processor bus attached “fax boards”, local area networks, Small Computer Systems Interface (ISO 9316), IEEE 1284 parallel ports, etc. The adaptation of the protocols and procedures to these alternative communication schemes is beyond the scope of this Recommendation.
+
+## **1.4 Overview**
+
+A system including a DTE and a facsimile DCE partitions Group 3 facsimile functions between the two devices. There are several levels in the communications path where a functional partition can be made. This Recommendation describes protocols for use at one of those levels, Service Class 1. Each level is described as a “Service Class” based on the functions performed by the DCE.
+
+### **1.4.1 Service Class 1**
+
+Clause 7 describes a set of services at the physical and data link layers: waiting, signalling, and HDLC data formatting. T.30 session management and T.4 image data handling are done by the DTE.
+
+### **1.4.2 Service Class 2**
+
+Recommendation T.32, Asynchronous Facsimile DCE Control, Service Class 2, describes a facsimile DCE which provides a set of services described by Recommendation T.30. The facsimile DCE makes and terminates calls, manages the communication session, and transports image data. The DTE prepares and interprets image data in compressed form, as described in Recommendation T.4.
+
+# 2 Normative references
+
+The following ITU-T Recommendations, and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; all users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published.
+
+- ITU-T Recommendation T.4 (1993), *Standardization of Group 3 facsimile apparatus for document transmission.*
+- ITU-T Recommendation T.30 (1993), *Procedures for document facsimile transmission in the general switched telephone network.*
+- ITU-T Recommendation T.32 (1995), *Asynchronous facsimile DCE control – Service Class 2.*
+- CCITT Recommendation T.50 (1992), *International Reference Alphabet (IRA) (formerly International Alphabet No. 5 or IA5) – Information technology – 7-bit coded character set for information interchange.*
+- CCITT Recommendation V.4 (1988), *General structure of signals of International Alphabet No. 5 code for character oriented data transmission over public telephone networks.*
+- ITU-T Recommendation V.8 (1994), *Procedures for starting and ending sessions of data transmission over the general switched telephone network.*
+- CCITT Recommendation V.17 (1991), *A 2-wire modem for facsimile applications with rates up to 14 400 bit/s.*
+- CCITT Recommendation V.21 (1988), *300 bits per second duplex modem standardized for use in the general switched telephone network.*
+- ITU-T Recommendation V.24 (1993), *List of definitions for interchange circuits between data terminal equipment (DTE) and data circuit-terminating equipment (DCE).*
+- CCITT Recommendation V.25 (1988), *Automatic answering equipment and/or parallel automatic calling equipment on the general switched telephone network including procedures for disabling of echo control devices for both manually and automatically established calls.*
+- ITU-T Recommendation V.25 *ter* (1995), *Serial asynchronous automatic dialling and control.*
+- CCITT Recommendation V.27 *ter* (1988), *4800/2400 bits per second modem standardized for use in the general switched telephone network.*
+- CCITT Recommendation V.29 (1988), *9600 bits per second modem standardized for use on point-to-point 4-wire leased telephone-type circuits.*
+- CCITT Recommendation V.33 (1988), *14 400 bits per second modem standardized for use on point-to-point 4-wire leased telephone-type circuits.*
+- ITU-T Recommendation V.34 (1994), *A modem operating at data signalling rates of up to 28 800 bit/s for use on the general switched telephone network and on leased point-to-point 2-wire telephone-type circuits.*
+- ISO 2111: 1985, *Data communication – Basic mode control procedures – Code independent information transfer.*
+
+# 3 Definitions
+
+For the purposes of this Recommendation, the following definitions apply:
+
+**3.1 DTE, Data Terminal Equipment:** A DTE is any terminal or computer capable of providing commands and data to operate a DCE or facsimile DCE. In practice, these are computers of any size.
+
+**3.2 DCE, Data Circuit Terminating Equipment:** A DCE is any device that connects a DTE to a communications network. This Recommendation focuses on DCEs which connect to the General Switched Telephone Network (GSTN). This class of DCEs includes DCEs compatible with the V-Series modem Recommendations and facsimile DCEs described below.
+
+**3.3 Facsimile DCE:** A facsimile DCE is a device which provides facsimile communication facilities between a DTE and the GSTN. A Class 1 facsimile DCE includes the following functions:
+
+- control functions;
+- interchange circuits to the DTE;
+- HDLC data link layer functions;
+- V-Series signal converters;
+- autodialler functions;
+- GSTN interface.
+
+**3.4 Facsimile DTE:** A facsimile DTE must provide those Group 3 facsimile functions and services not provided by the facsimile DCE. The specific implementation of these functions is beyond the scope of this Recommendation.
+
+# 4 Abbreviations
+
+For the purposes of this Recommendation, the following abbreviations are used:
+
+|       |                                                                           |
+|-------|---------------------------------------------------------------------------|
+| CCITT | International Telegraph and Telephone Consultative Committee              |
+| IEEE  | Institute of Electrical and Electronics Engineers                         |
+| IRA   | International Reference Alphabet (Recommendation T.50)                    |
+| ISO   | International Organization for Standardization                            |
+| ITU-T | International Telecommunication Union – Telecommunication Standardization |
+| XON   | IRA DC1 character, used to enable data flow on the opposite circuit       |
+| XOFF  | IRA DC3 character, used to disable data flow on the opposite circuit      |
+
+# 5 Facsimile DTE-DCE interchange circuits
+
+A facsimile DCE described by this Recommendation uses an asynchronous serial connection between the DTE and the DCE. Serial data is formatted in 10 bit character frames, including a start bit, 8 data bits, no parity and 1 stop bit (see Recommendation V.4). Use of this protocol on other DTE-DCE interfaces is beyond the scope of this Recommendation.
+
+## 5.1 DTE-DCE communication link data rates
+
+The DTE-facsimile DCE communications link shall provide full duplex character data at rates fast enough to accommodate the transfer of synchronous T.30 Phase C data. A data rate greater than or equal to 18000 bit/s (e.g. 19200 bit/s) is the minimum rate needed to support 14400 bit/s V.17 Phase C data. With flow control, it is not necessary, and not recommended, to change the DTE-DCE communications link data rate during facsimile operation. Mechanisms to set the DTE-DCE serial rate are described in 6.10 and 6.2.10/V.25 *ter* (IPR parameter).
+
+## 5.2 Asynchronous to synchronous conversion
+
+Group 3 data communication is bit-synchronous. The DCE must delete, start and stop elements from these characters before transmission and add them to received octets. Bit sequencing is maintained between the DTE-DCE interface and the DCE-remote station interface, as specified in Recommendations T.4 and T.30.
+
+## 5.3 Flow control
+
+Flow control is necessary to match the DTE-DCE data rate to the line signalling rate and to the requirements of Group 3 data transmission. (For example, provision must be made for minimum scan line times.) Provision of in-band unidirectional DC1/DC3 (T.50 1/1 and 1/3) flow control is mandatory; flow control using V.24 circuits 106 and 133 is optional.
+
+This Recommendation specifies a mandatory command to configure DCE flow control, the +IFC command from 6.2.12/V.25 *ter*.
+
+The response times of the DCE to indication of a DTE not-ready condition and of the DTE to indication of a DCE not-ready condition are for further study. These times should be kept as short as practical. DCEs should accommodate latency in the DTE recognition of the DCE not-ready indication by accepting several characters on Circuit 103 after the indication is given.
+
+NOTE – A facsimile DCE may provide additional data buffering beyond the needs of flow control.
+
+## 5.4 Serial data interchange circuits
+
+### 5.4.1 Mandatory circuits
+
+The required circuits are shown in Table 1:
+
+TABLE 1/T.31
+
+**Mandatory serial data interchange circuits**
+
+| V.24 circuit | Description      |
+|--------------|------------------|
+| 102          | Signal ground    |
+| 103          | Transmitted data |
+| 104          | Received data    |
+
+### 5.4.2 Optional circuits
+
+The optional circuits are shown in Table 2:
+
+TABLE 2/T.31
+
+**Optional serial data interchange circuits**
+
+| V.24 circuit | Description                                |
+|--------------|--------------------------------------------|
+| 133          | Ready for receiving                        |
+| 105          | Request to send                            |
+| 106          | Ready for sending                          |
+| 107          | Data set ready                             |
+| 108/2        | Data terminal ready                        |
+| 109          | Data channel received line signal detector |
+| 125          | Calling indicator                          |
+
+Provision of additional circuits is optional, but not addressed in this Recommendation.
+
+### 5.4.3 Optional circuit behaviour
+
+The behaviour of circuits 105, 106, and 133 is described in 6.9 and 6.2.12/V.25 *ter*.
+
+The behaviour of circuit 108/2 is described in 6.6.
+
+The behaviour of circuit 125 is described in 6.4.
+
+Circuit 107, if provided, shall be held in the ON condition at all times when the DCE is powered on and +FCLASS = 1.0. Manufacturers may provide an option, controlled by the AT&C command (6.2.8/V.25 *ter*), to cause Circuit 107 to obey the V.24 definition, which is for circuit 107 to be ON only when the DCE is off-hook, and OFF when the DCE is on-hook.
+
+Circuit 109, if provided, shall normally be held in the ON condition at all times when the DCE is powered on and +FCLASS = 1.0. Manufacturers may provide an option to cause circuit 109 to obey the definitions in the selected V-Series modem. The &C command, defined in 6.2.8/V.25 *ter*, may be used for this purpose; the &C0 setting holds circuit 109 always in the ON condition, and the &C1 setting would select the behaviour in which circuit 109 indicates the status of the selected V-Series modem.
+
+# 6 Autodialler services
+
+The protocol described in this Recommendation requires services common to those provided by serial asynchronous Automatic Calling Equipment (ACE).
+
+## 6.1 Command syntax
+
+The T.50 International Alphabet No. 5 is used for the issuance of commands and responses. Only the low order 7 bits of each character are used for commands or parameters; the high order bit is ignored. Upper case characters are equivalent to lower case characters.
+
+For data transmission or reception, all 8 bits are needed.
+
+A command line is a string of characters sent from a DTE to the facsimile DCE, while the DCE is in a command state. Command lines have a prefix, a body, and a terminator. The prefix consists of the IRA characters “AT” or “at”. The body is a string of commands restricted to printable IRA characters. Space characters (IRA 2/0) and control characters other than CR (IRA 0/13), LF (IRA 0/10) and BS (IRA 0/8) in the command string are ignored. The default terminator is the IRA <CR> character; DCE may implement the S3 register command defined in 6.2.1/V.25 *ter*.
+
+Characters that precede the AT prefix are ignored.
+
+Characters within the command line shall be parsed as commands with associated parameter values. The basic commands consist of single IRA characters, or single characters preceded by a prefix character (e.g. “&”, IRA 3/6) and followed by a numeric parameter. Missing numeric parameters are evaluated as 0.
+
+The commands described in this Recommendation are preceded by the “+F” characters (IRA 2/11, 4/6), and they are terminated by the “;” character (IRA 3/11) or by the command line termination character (e.g. <CR>). The “+F” lead-in is reserved in Recommendation V.25 *ter*.
+
+## **6.2 Command execution**
+
+Upon receipt of the termination character, the DCE shall commence execution of the commands in the command line, if any. The DCE shall execute the commands in the body of the command line left-to-right. Each command is individually executed regardless of what follows on the line. If all commands execute properly, a final result code, for the final command, is issued after execution of the final command. If an invalid command is encountered, or if execution of any command results in an error, execution of the command line is terminated at that point and all subsequent commands on the line are ignored. Commands in the line prior to the error will have already been executed.
+
+### **6.2.1 Command execution time**
+
+Parameter commands are assumed to execute instantaneously; these cannot be aborted. Action commands which require time to execute (see 8.3) may be aborted while in progress, until the final result code is issued (see 6.8).
+
+### **6.2.2 Aborting commands**
+
+Commands which may be aborted are explicitly noted in the description of the command. Aborting of commands is accomplished by the transmission from the DTE to the DCE of any character, other than those explicitly required (e.g. <DC1> and <DC3> for flow control). A single character shall be sufficient to abort the command in progress. When such an aborting event is recognized by the DCE, it shall terminate the command in progress and return an OK result code to the DCE.
+
+## **6.3 Response syntax**
+
+This Recommendation describes two types of responses: information text and result codes.
+
+Information text responses shall always be preceded by the IRA characters <CR> <LF>, and followed by <CR> <LF>, unless set to some other characters by user option. If provided by the manufacturer, the S3 and S4 registers defined in 6.2.1/V.25 *ter* and 6.2.2/V.25 *ter* may be used to select the command line termination character (default <CR>) and the response formatting character (default <LF>).
+
+A facsimile DCE described by this Recommendation shall provide verbose (alphabetic) and non-verbose (numeric) format for result code responses to the DTE. A user-selectable option shall be provided to select the format; a method to do so is defined in 6.2.6/V.25 *ter*, ATV.
+
+In the verbose format, result code responses are preceded by the IRA characters <CR> <LF>, and followed by <CR> <LF>. In the non-verbose format, result code responses are preceded by no characters, and followed by a single <CR>.
+
+## **6.4 Capabilities identification and control**
+
+A facsimile DCE shall maintain a parameter for identification and control of facsimile services, “+FCLASS”. This parameter can be read to determine the current setting, written to change the current setting, and interrogated to determine the allowed range. This parameter is described in 8.2.
+
+## 6.5 Call answering
+
+A facsimile DCE provide for automatic and manual answering of calls. The ATA command described in 6.3.5/V.25 *ter* is recommended.
+
+A facsimile DCE shall generate a CED tone, as required by Recommendation T.30. Facsimile answer connect actions are specified in 7.1.1.
+
+NOTE – The use of other signalling conventions in place of CED (e.g. the ANSam signal from Recommendation V.8) is for future study. The DCE may indicate incoming calls on V.24 Circuit 125, or using the RING result code (see 6.8), or both.
+
+## 6.6 Call origination
+
+A facsimile DCE shall provide for automatic and manual origination of calls. The ATD<string> command described in 6.3.1/V.25 *ter* is recommended.
+
+A facsimile DCE shall generate a CNG tone, as described by Recommendation T.30. Facsimile origination connect actions are specified in 7.1.2.
+
+NOTE – The use of other signalling conventions in place of or in addition to CNG (e.g. the CI signal from Recommendation V.8) is for future study.
+
+## 6.7 Call termination
+
+A facsimile DCE described by this Recommendation shall provide for automatic and manual termination of calls. An ON-to-OFF transition of V.24 Circuit 108/2, if provided, shall cause the DCE to disconnect the call and go on-hook, unless configured otherwise by the user (see 6.2.9/V.25 *ter*, AT&D). The ATH command described in 6.3.6/V.25 *ter* is recommended.
+
+## 6.8 Result codes
+
+See Table 3.
+
+TABLE 3/T.31
+
+### Mandatory autodialler result codes
+
+| Numeric                                                                                                                      | Verbose    | Description                                                                                                                                                                                               |
+|------------------------------------------------------------------------------------------------------------------------------|------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| 0                                                                                                                            | OK         | The previous command or operation was completed normally; the DCE is ready for another command                                                                                                            |
+| 1                                                                                                                            | CONNECT    | The DCE has entered the data transfer state                                                                                                                                                               |
+| 3                                                                                                                            | NO CARRIER | The DCE has detected the loss of carrier from the remote facsimile terminal during a reception operation. The local DCE is ready for a command. This message does not imply that the DCE has gone On-Hook |
+| 4                                                                                                                            | ERROR      | The previous command or operation was not recognized or was completed abnormally; the DCE is ready for another command                                                                                    |
+| NOTE – The ATX command defined in 6.2.7/V.25 <i>ter</i> may be used by a Facsimile DCE; this command enables other messages. |            |                                                                                                                                                                                                           |
+
+Other result codes described in Table 1/V.25 *ter* may be provided by the DCE.
+
+## 6.9 Serial port flow control
+
+A facsimile DCE shall provide for DC1/DC3 (XON/XOFF) flow control. A facsimile DCE may also implement other types of flow control, such as V.24 Circuits 106 and 133. The DCE shall support the +IFC command from 6.2.12/V.25 *ter*. The DCE shall also support the +FLO command (Annex A).
+
+## 6.10 Serial port speed control
+
+The DCE may detect the DTE-DCE serial port data rate based on the “AT” or “at” command line prefix. Otherwise, the DCE may require a fixed serial port rate determined by the manufacturer, by user strap option, or by an explicit command. The DCE shall support the +IPR command, 6.2.10/V.25 *ter*. The DCE shall also support the +FPR command (Annex A).
+
+## 6.11 Transparent data commands
+
+A Service Class 2 Facsimile DCE transfers Phase C data in streams while executing data transfer commands (+FDT, see 8.3.3; +FDR, see 8.3.4). A Facsimile DCE shall recognize transparent data stream commands in transmitted data, and it shall insert transparent data stream commands into received data. This method is based on ISO 2111.
+
+The T.50 <DLE> character (1/0) is used as a special character, to precede command characters. Character pairs <DLE> <command> are used to mark the end of data, and to convey other commands or status information between DTE and DCE. These characters are octet-aligned. Character pairs used are summarized in Table 4. The following example patterns are used:
+
+TABLE 4/T.31
+
+**Transparent data commands**
+
+| Data stream                                                                                                          | Definition                                                      |
+|----------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------|
+| Any data...<DLE> <ETX>                                                                                               | End of stream                                                   |
+| Any data...<DLE> <DLE>...                                                                                            | Single 1/0 in data stream                                       |
+| Any data...<DLE> <SUB>...                                                                                            | Two consecutive 1/0 1/0 in data stream, if +FDD = 1 (see 8.5.3) |
+| Any data...<DLE> <command>                                                                                           | Remove <DLE> <command>, and interpret <command> if valid        |
+| NOTE – The use of new valid transparent data commands, in addition to those defined in Table 4, is for future study. |                                                                 |
+
+### 6.11.1 DTE to DCE streams
+
+The DCE shall decode the data stream from the DTE, and remove all character pairs beginning with <DLE>. The DCE shall recognize <DLE> <ETX> as the stream terminator. The DCE shall recognize and replace <DLE> <DLE> by a single <DLE>. If the +FDD parameter is set to 1 (see 8.5.3), the DCE shall recognize and replace <DLE> <SUB> (IRA 1/0, 1/10) by <DLE> <DLE>.
+
+The DTE shall encode stream data to the DCE, and insert a <DLE> character ahead of <10h> data. If the +FDD = 1, the DTE may also replace consecutive pairs of <10h> <10h> by <DLE> <SUB> (IRA 1/0, 1/10).
+
+### 6.11.2 DCE to DTE streams
+
+The DTE shall decode the data stream from the DCE, and remove all character pairs beginning with <DLE>. The DTE shall recognize <DLE> <ETX> as the stream terminator. The DTE shall recognize and replace <DLE> <DLE> by a single <DLE>. If the +FDD parameter is set to 1 (see 8.5.3), the DTE shall recognize and replace <DLE> <SUB> by <DLE> <DLE>.
+
+The DCE shall encode stream data to the DTE, and insert a <DLE> character ahead of <10h> data. If the +FDD = 1, the DCE may also replace consecutive pairs of <10h> <10h> by <DLE> <SUB>.
+
+# 7 Facsimile Service Class 1
+
+A Service Class 1 facsimile DCE provides a basic level of services necessary to support Group 3 facsimile operation. This requires support from the facsimile DTE to implement the T.30 recommended procedures for document facsimile transmission and Recommendation T.4 for representing facsimile images.
+
+Service Class 1 includes the following services, as required or optional in Group 3 facsimile:
+
+- a) connection;
+- b) waiting and silence detection;
+- c) data transmission and reception;
+- d) HDLC data framing, transparency and error detection;
+- e) message generation.
+
+## 7.1 Connection establishment
+
+### 7.1.1 Answer connection
+
+The DCE must be set for Service Class 1 operation prior to answering a call; this can be done by setting +FCLASS = 1.0 (see 8.2.3).
+
+After the call is answered, (see 6.3.5/V.25 *ter*) an answering Service Class 1 facsimile DCE generates a CED tone as described in 6.5. Then it enters clause 2/V.21 transmit state with HDLC framing, as described for the +FTH = 3 command (see 8.3.5), and issues a CONNECT result code. The DTE shall then begin transmission of the first T.30 control frame. As per Recommendation T.30, for proper interaction with manually originated facsimile stations, detection of CNG is not required. The DCE manufacturer may provide a user-setable parameter to cause the DCE to abandon the call if no CED or DIS is received within a specified time (see S7, 6.3.10/V.25 *ter*).
+
+NOTE – The use of other signalling conventions in place of or in addition to CED and clause 2/V.21 (e.g. V.8 call negotiation signals, and the V.34 modem carrier) is for future study.
+
+### 7.1.2 Originate connection
+
+The DCE must be set for Service Class 1 operation prior to originating a call; this can be done by setting +FCLASS = 1.0.
+
+After the call is placed (see 6.3.1/V.25 *ter*), an originating Service Class 1 facsimile DCE shall generate a CNG tone as described in 6.6. Then it enters clause 2/V.21 receive state with HDLC framing, as described for the +FRH = 3 command (see 8.3.6). The DTE should be prepared to accept the first T.30 control frame. As per Recommendation T.30, for proper interaction with manually answered facsimile stations, detection of CED should not be required. The DCE manufacturer may provide a user-setable parameter to cause the DCE to abandon the call if no CED or DIS is received within a specified time (see S7, 6.3.10/V.25 *ter*).
+
+NOTE – The use of other signalling conventions in place of CNG and clause 2/V.21 (e.g. V.8 call negotiation signals, and the V.34 modem carrier) is for future study.
+
+## 7.2 Waiting and silence detection
+
+These commands are used to implement signalling delineation as required in 5.3.2.3/T.30, and Notes 3 and 4 in clause 5/T.30 and the “signal gone” test required in 5.2/T.30.
+
+### 7.2.1 Waiting
+
+A Service Class 1 facsimile DCE can be commanded to pause with an idle line, using the +FTS = <time> command (see 8.3.1).
+
+### 7.2.2 Silence detection
+
+A Service Class 1 facsimile DCE can be commanded to wait for a specified amount of silence on the line, using the +FRS = <time> command (see 8.3.2).
+
+## 7.3 Data transfer
+
+A Service Class 1 facsimile DCE can transfer serial data using any supported signalling method. Clause 2/V.21 and V.27 *ter* signalling are mandatory, as required by Recommendations T.4 and T.30. V.29, V.17 and V.33 signalling are optional. The use of Recommendation V.34 is for further study.
+
+Facsimile data transmission and reception, without HDLC framing, are controlled by two commands: +FTM = <mod> and +FRM = <mod> respectively (see 8.3.3 and 8.3.4).
+
+## 7.4 HDLC framing, transparency, and error detection
+
+HDLC framing is used in all Group 3 facsimile control signalling (see 5.3/T.30), and is optional for Phase C data in Error Correcting Mode (Annex A/T.4, Annex A/T.30). A Service Class 1 facsimile DCE supports HDLC framing as required for 300 bit/s V.21 signalling, and may optionally provide HDLC framing using any supported signalling method.
+
+In these modes the DCE has several tasks:
+
+- a) transmit flags on an idle line;
+- b) recognize and delete received flags;
+- c) HDLC zero bit insertion/deletion;
+- d) generate FCS for transmitted frames;
+- e) detect and check FCS for received frames;
+- f) recognize final frames.
+
+All other required HDLC services are provided by the DTE.
+
+These facilities are invoked using the +FTH = <MOD> and +FRH = <MOD> commands (see 8.3.5 and 8.3.6).
+
+## 7.5 Facsimile carrier error message response
+
+Service Class 1 facsimile DCEs are commanded by the DTE to look for a particular tone or carrier signal. If the DCE detects that it received a different signal, the DCE shall inform the DTE with the +FCERROR message (see 8.4). This allows the DTE to recover by commanding the DCE to look for an alternative tone or carrier signal.
+
+# 8 Service Class 1 commands and responses
+
+This clause contains detailed descriptions of each DTE command and DCE response message, including syntax, allowable arguments, description of action, result codes, timing, aborting events and cross references.
+
+## 8.1 Command summary
+
+See Table 5.
+
+TABLE 5/T.31
+
+### Class 1 command summary
+
+| Command                                                                                                                                                                                                                                                                                                                                                                                         | Reference              | Description                                 |
+|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------|---------------------------------------------|
+| +FCLASS                                                                                                                                                                                                                                                                                                                                                                                         | 8.2.1 to 8.2.3         | Select, read or test Service Class (Note 1) |
+| +FTS = <Time>                                                                                                                                                                                                                                                                                                                                                                                   | 8.3.1                  | Stop transmission and pause                 |
+| +FRS = <Time>                                                                                                                                                                                                                                                                                                                                                                                   | 8.3.2                  | Wait for silence                            |
+| +FTM = <MOD>                                                                                                                                                                                                                                                                                                                                                                                    | 8.3.3                  | Transmit data with <MOD> carrier            |
+| +FRM = <MOD>                                                                                                                                                                                                                                                                                                                                                                                    | 8.3.4                  | Receive data with <MOD> carrier             |
+| +FTH = <MOD>                                                                                                                                                                                                                                                                                                                                                                                    | 8.3.5                  | Transmit HDLC data with <MOD> carrier       |
+| +FRH = <MOD>                                                                                                                                                                                                                                                                                                                                                                                    | 8.3.6                  | Receive HDLC data with <MOD> carrier        |
+| +FAR = <off/on>                                                                                                                                                                                                                                                                                                                                                                                 | 8.5.1                  | Adaptive reception control                  |
+| +FCL =                                                                                                                                                                                                                                                                                                                                                                                          | 8.5.2                  | Carrier loss timeout                        |
+| +FDD = <value>                                                                                                                                                                                                                                                                                                                                                                                  | 8.5.3                  | Double escape character replacement control |
+| +FIT = <time>, <action>                                                                                                                                                                                                                                                                                                                                                                         | 8.5.4                  | DTE inactivity timeout                      |
+| +GMI?                                                                                                                                                                                                                                                                                                                                                                                           | 6.1.4/V.25 <i>ter</i>  | Report manufacturer ID                      |
+| +GMM?                                                                                                                                                                                                                                                                                                                                                                                           | 6.1.5/V.25 <i>ter</i>  | Report model ID                             |
+| +GMR?                                                                                                                                                                                                                                                                                                                                                                                           | 6.1.6/V.25 <i>ter</i>  | Report revision ID                          |
+| +IPR =                                                                                                                                                                                                                                                                                                                                                                                          | 6.2.10/V.25 <i>ter</i> | Local DTE-DCE serial port rate              |
+| +IFC =                                                                                                                                                                                                                                                                                                                                                                                          | 6.2.12/V.25 <i>ter</i> | Local DTE-DCE flow control                  |
+| A                                                                                                                                                                                                                                                                                                                                                                                               | 6.3.5/V.25 <i>ter</i>  | Answer                                      |
+| D <string>                                                                                                                                                                                                                                                                                                                                                                                      | 6.3.1/V.25 <i>ter</i>  | Dial                                        |
+| H                                                                                                                                                                                                                                                                                                                                                                                               | 6.3.6/V.25 <i>ter</i>  | Hangup                                      |
+| NOTE – Some of these commands and parameters are defined for other Facsimile DCE Service Classes. For any Facsimile DCE that supports multiple Service Classes, the DCE shall implement only one instance of those common parameters, visible for each Service Class that supports those common parameters, and those parameter values shall persist during changes of Facsimile Service Class. |                        |                                             |
+
+All of the action commands (see 8.3.1 to 8.3.6) return an ERROR result code if issued when the DCE is on-hook.
+
+All commands using the <MOD> value and all parameters can be tested for the range of values supported by the DCE, using the +<command>=? syntax. The DCE returns information text consisting of a list of all supported values, separated by commas. For example, a “+FTH=?” command to a minimum Class 1 DCE would report: <CR> <LF> <“3”> <CR> <LF> (ATV1). A completely capable DCE could report (with ATV0, 6.2.6/V.25 *ter*):
+
+3,24,48,72,73,74,96,97,98,121,122,145,146<CR>.
+
+The MOD parameter may take on the following values (see Table 6):
+
+TABLE 6/T.31
+
+### **Service Class 1 command modulation select codes**
+
+| <MOD><br>Value | Modulation           | Train time | Rate<br>(bit/s) | Required    |
+|----------------|----------------------|------------|-----------------|-------------|
+| 3              | Clause 2/V.21        |            | 300             | +FTH & +FRH |
+| 24             | Rec. V.27 <i>ter</i> |            | 2 400           | +FTM & +FRM |
+| 48             | Rec. V.27 <i>ter</i> |            | 4 800           | +FTM & +FRM |
+| 72             | Rec. V.29            |            | 7 200           |             |
+| 73             | Rec. V.17            | Long       | 7 200           |             |
+| 74             | Rec. V.17            | Short      | 7 200           |             |
+| 96             | Rec. V.29            |            | 9 600           |             |
+| 97             | Rec. V.17            | Long       | 9 600           |             |
+| 98             | Rec. V.17            | Short      | 9 600           |             |
+| 121            | Rec. V.17 or V.33    | Long       | 12 000          |             |
+| 122            | Rec. V.17            | Short      | 12 000          |             |
+| 145            | Rec. V.17 or V.33    | Long       | 14 400          |             |
+| 146            | Rec. V.17            | Short      | 14 400          |             |
+
+All other codes are reserved.
+
+NOTE – The use of Recommendation V.34 for data transfer is for further study.
+
+## 8.2 Capabilities identification and control
+
+### 8.2.1 Service class indication, +FCLASS?
+
+The current Service Class setting of a facsimile DCE is read by the “+FCLASS?” command. The information text response is a single value:
+
+- 0 indicates a data modem (e.g. Recommendation V.25 *ter*);
+- 1.0 indicates a Service Class 1 facsimile DCE;
+- 2.0 indicates a Service Class 2 facsimile DCE (e.g. Recommendation T.32).
+
+Other values are reserved.
+
+NOTE – Some existing DCE accept and report values 1 (IRA 3/1) and 2 (IRA 3/2) for +FCLASS.
+
+### 8.2.2 Service class capabilities, +FCLASS = ?
+
+The Service Classes available from a facsimile DCE are tested by the “+FCLASS = ?” command. The information text response is a list of values, separated by commas. For example, a DCE that supported data communication and facsimile Service Class 1 would respond with “0,1.0” as the information text.
+
+### 8.2.3 Service class selection, +FCLASS = <value>
+
+The Service Class may be set by the DTE from the choices available (see above), using the “+FCLASS = <value>” command. To configure a DCE for Service Class 1, the DTE issues the command: “AT+FCLASS = 1.0”.
+
+NOTE – Parameters defined in other standards (e.g. Recommendation V.25 *ter*) may be used while +FCLASS = 1.0 (e.g. ATV, ATX, AT&D, ATS7, ATS8). However, this Recommendation does not specify the relationship between these parameter settings made while +FCLASS = 1.0 or while +FCLASS = 0. DTE should set these commands explicitly while +FCLASS = 1.0.
+
+## 8.3 Service Class 1 action commands
+
+### 8.3.1 Transmit silence, +FTS = <Time>
+
+- Write syntax: FTS = <Time>
+- Valid values: see Table 6
+- Default value: none
+- Mandatory values: 0-255
+
+The command +FTS = <Time> causes the DCE to stop any transmission. The DCE then waits for the specified amount of time, and then sends the OK result code to the DTE. The value <Time> is in 10 millisecond intervals.
+
+### 8.3.2 Receive silence, +FRS = <Time>
+
+- Write syntax: +FRS = <Time>
+- Valid values: see Table 6
+- Default value: none
+- Mandatory values: 0-255
+
+The command +FRS = <Time> causes the DCE to listen, and to report back an OK result code when silence has been present on the line for the amount of time specified. The value <Time> is in 10 millisecond intervals. The command will terminate when the required amount of silence on the line is detected or when the DTE sends the DCE another character other than DC1 (0/1) or DC3 (0/3), which is discarded. In either event, the OK result code will be returned to the DTE.
+
+### 8.3.3 Facsimile transmit, +FTM = <MOD>
+
+- Write syntax: +FTM = <MOD>
+- Valid values: see Table 6
+- Default value: none
+- Mandatory values: 24, 48
+
+The command +FTM = <MOD> causes the DCE to transmit data using the modulation selected in <MOD>. <MOD> may have the values shown in Table 6.
+
+The DCE returns the CONNECT result code and transmits the proper training sequence in the selected mode, followed by constant 1 bits, until data is received from the DTE. During execution of the +FTM command, the DCE shall issue the CONNECT result code at the beginning of transmission of the training pattern for the selected modulation scheme rather than at the end of training.
+
+The DCE shall detect <DLE> <ETX> characters as data stream terminators, as described in 6.11. The DCE shall filter the data stream as specified in 6.11.1.
+
+The DCE buffers data in this mode. The configured flow control method will be used by the DCE as necessary to pause the DTE.
+
+If the DCE's transmit buffer becomes empty and the last transmitted character is IRA NUL (00), the DCE shall continue to transmit NULs until the DTE sends more data or five seconds elapses. After five seconds elapse with an empty transmit buffer, the DCE will turn off transmit carrier and return to command state, returning the ERROR result code.
+
+If the DCE's transmit buffer becomes empty and the last transmitted character was not NUL, the DCE shall turn off transmit carrier, return to command state and send the OK result code to the DTE.
+
+NOTE – In order to reliably produce  $1.5 \pm 0.15$  seconds of zero bits for TCF, the DTE should send sufficient <NUL> (IRA 0/0) characters to generate the required number of zero bits.
+
+### 8.3.4 Facsimile receive, +FRM = <MOD>
+
+- Write syntax: +FRM = <MOD>
+- Valid values: see Table 6
+- Default value: none
+- Mandatory values: 24, 48
+
+The command +FRM = <MOD> causes the DCE to enter receive mode using the modulation specified in <MOD>. <MOD> may have the values shown in Table 6.
+
+When the selected carrier is detected, the DCE will send the CONNECT result code to the DTE. If a different signal is detected, and +FAR = 0 (see 8.5.1), the DCE shall send a +FCERROR (Connect Error, see 8.4) result code to the DTE, and return to command state; if +FAR = 1, see 8.5.1.
+
+The DCE shall transfer all received data patterns to the DTE as consecutive start-stop framed octets, including leading Marking condition or Flags. The DCE shall mark the end of the stream with the <DLE> <ETX> characters. The DCE shall filter data streams as specified in 6.11.2.
+
+The DCE shall return to command state upon loss of carrier, and send the NO CARRIER result code to the DTE.
+
+The DCE shall obey the configured flow control from the DTE. If the DTE sends any character to the DCE other than DC1 or DC3 while the DCE is in this mode, the DCE shall enter command state and send the OK result code to the DTE.
+
+### 8.3.5 HDLC transmit, +FTH = <MOD>
+
+- Write syntax: FTH = <MOD>
+- Valid values: see Table 6
+- Default value: none
+- Mandatory value: 3
+
+The command +FTH = <MOD> causes the DCE to transmit data framed in HDLC protocol using the modulation mode selected. <MOD> may have the values shown in Table 6.
+
+The DCE shall send the CONNECT result code to the DTE, and transmit signal converter training (if required) followed by flags until the first octet of data is sent by the DTE. During execution of the +FTH command, the DCE shall issue the CONNECT result code at the beginning of transmission of the training pattern for the selected modulation scheme rather than at the end of training.
+
+The DCE shall decode the data stream as specified in 6.11.1. The DCE shall detect the <DLE> <ETX> characters as a data stream terminator, as specified in 6.11.1.
+
+When the buffer becomes empty, the DCE shall compute and append the Frame Check Sequence (FCS) and a closing flag to the frame. The DCE shall ensure that the minimum number of flags required by Recommendation T.30 are sent before the DTE begins to transmit data. Note that the DTE should always indicate the end of transmitted HDLC frames by appending the <DLE> <ETX> sequence.
+
+The DCE shall check the Final Frame bit in the control field of each frame; this is the 5th received bit of the second octet of each frame. If the Final Frame bit is 1, the DCE shall cease transmitting after the frame is sent, return to command state, and send the OK result code to the DTE. If the Final Frame bit is 0, the DCE shall send the CONNECT result code to the DTE and continue to transmit flags until one of the following actions is taken by the DTE:
+
+- a) if the DTE sends additional data, the DCE shall transmit another frame;
+- b) if the DTE sends only <DLE> <ETX> (a null frame), the DCE shall turn off transmit carrier and send the OK result code to the DTE;
+- c) if five seconds elapses from the time when the DCE reported the CONNECT result code without any additional data transmitted from the DTE, the DCE shall turn off transmit carrier, return to command mode, and send the ERROR result code to the DTE.
+
+The DCE performs HDLC transparency functions and FCS generation while in this mode.
+
+The DCE buffers data in HDLC transmit mode. The DCE will use the configured method of flow control to pause the DTE as necessary.
+
+### 8.3.6 HDLC receive, +FRH = <MOD>
+
+- Write syntax: +FRH = <MOD>
+- Valid values: see Table 6
+- Default value: none
+- Mandatory value: 3
+
+The command +FRH = <MOD> causes the DCE to receive HDLC framed data using the modulation mode selected in <MOD>, and deliver the next received frame to the DTE. <MOD> may have the values shown in Table 6.
+
+If the DCE detects the selected carrier with an HDLC flag, the DCE shall send the CONNECT result code to the DTE. When the selected carrier is detected, the DCE shall send the CONNECT result code to the DTE. If a different signal is detected, and +FAR = 0 (see 8.5.1), the DCE shall send a +FCERROR (Connect Error, see 8.4) result code to the DTE, and return to command state; if +FAR = 1, see 8.5.1. The DCE shall return to command state upon loss of carrier, sending the NO CARRIER result code to the DTE.
+
+The DCE strips flags, and receives and buffers frames. The received data, starting with the first non-flag octet and continuing through the last FCS octet shall be transferred to the DTE. The DTE may ignore the value of the FCS octets. The DCE performs HDLC zero-bit deletion and error checking. The DCE shall filter the data stream as specified in 6.11.2.
+
+After the FCS octets are transferred, the DCE shall mark the end of the frame with the characters <DLE> <ETX>, and report the status of the frame reception to the DTE:
+
+- a) if the frame was received correctly (FCS is OK), the DCE shall return the OK result code;
+- b) if the frame was received in error (FCS is not OK, or carrier lost, or data lost due to data overflow), the DCE shall return the ERROR result code; the DTE should discard the frame.
+
+After the status result code, the DCE shall accept new commands from the DTE.
+
+The DCE shall obey the configured flow control from the DTE (see +IFC, 6.2.12/V.25 *ter*). If the DTE sends any character to the DCE other than DC1 or DC3 while the DCE is in this mode, the DCE shall enter command state and return the OK result code, and may discard any buffered data.
+
+After sending the result code indicating that frame reception is complete, the DCE shall continue to receive and buffer data in the selected mode. If the DTE issues another +FRH = <MOD> command, the DCE shall return another CONNECT result code and continue with HDLC reception. If the DTE issues any command that changes modulation, the DCE shall stop the receive process; any buffered data shall be discarded and the command will be obeyed.
+
+## 8.4 Service Class 1 result codes
+
+### 8.4.1 Connect error
+
+If the DCE detects a data carrier or tone of any kind, other than that specified in a +FRM or +FRH command, it shall send the +FCERROR result code and return to command state. This allows the DTE to recover by reconfiguration of the DCE to determine the nature of that signal.
+
+The +FCERROR message has the following syntax:
+
+- Verbose                Numeric
+- +FCERROR            +F4
+
+### 8.4.2 Adaptive modulation detection report
+
+If the +FAR parameter is set to 1, and if V.21 flags are detected while executing a +FRH = <mod> or +FRM = <mod> command, the DCE shall generate an intermediate result code to indicate V.21 reception (see 8.3.4 and 8.3.6). This report shall be issued before the CONNECT final result code. This report has the following syntax:
+
+- +FRH:3
+
+## 8.5 Service Class 1 parameters
+
+This Recommendation contains one parameter to condition the use of the +FRM and +FRH commands, one parameter to specify the handling of sequential escape characters, and two commands to specify timers.
+
+### 8.5.1 Adaptive reception control (+FAR)
+
+- Write syntax:            +FAR = <value>
+- Valid values:            0, 1
+- Default value:           0
+- Mandatory value:        0
+
+If Adaptive Reception is enabled, the DCE shall adaptively detect the selected message carrier or V.21 control messages. If the expected carrier is detected, the DCE shall operate as specified in the respective +FRM = <mod> or +FRH = <mod> commands. If V.21 flag preamble is detected instead, the DCE shall issue a +FRH:3 intermediate result code, and then execute an implied +FRH = 3 command.
+
+- +FAR = 0                Adaptive Reception Disabled (default).
+- +FAR = 1                Adaptive Reception Enabled.
+
+### 8.5.2 Carrier loss timeout, +FCL
+
+- Write syntax:            +FCL = <time>
+- Valid values:            <time> = 0-255 in 100 ms increments
+- Default value:           Manufacturer specific
+- Mandatory values:       0-255
+
+The FCL parameter allows the DTE to select the DCE's loss-of-carrier delay between initial loss-of-carrier and qualified loss-of-carrier, when the DCE will give up and exit a receive mode. Intermediate (less than FCL timeout) loss-of-carrier should be indicated by insertion of the SQ-BAD signal quality indicator in the received data stream.
+
+In unframed receive modes, if the DCE detects RTC as described in Recommendation T.30 prior to initial loss of the high speed carrier, or if the DCE detects V.21 carrier after initial loss of high speed carrier, then the DCE shall immediately accept the loss-of-carrier as qualified, without waiting for the FCL timer to expire.
+
+In HDLC receive modes if the DCE detects HDLC abort prior to initial loss of the high speed carrier, or if the DCE detects V.21 carrier after initial loss of high speed carrier, then the DCE shall immediately accept the loss-of-carrier as qualified, without waiting for the FCL timer to expire.
+
+### 8.5.3 Double escape character replacement, +FDD
+
+- Write syntax:            +FDD = <value>
+- Valid values:            0, 1, see Table 7
+- Default value:           0
+- Mandatory value:        0
+
+This optional parameter conditions the use of the <DLE> <SUB> pair to encode consecutive <1/0> <1/0> in data. This may be used to prevent unbound expansion of data that contains many <1/0> patterns. Use of <DLE> <character> commands are described in 6.11. See Table 7.
+
+TABLE 7/T.31
+
+#### **+FDD parameter values and functions**
+
+| +FDD Value | DCE decode of <DLE><SUB> | DCE encoding of <1/0> <1/0> |
+|------------|--------------------------|-----------------------------|
+| 0          | <DLE> <DLE> or discard   | <DLE> <DLE> <DLE> <DLE>     |
+| 1          | <DLE> <DLE>              | <DLE> <SUB>                 |
+
+### **8.5.4 DTE inactivity timeout, +FIT**
+
+- Write syntax:            +FIT = <time>, <action>
+- Valid values:            Time = unlimited, action = 0,1
+- Default value:           Time = 0, action = 0
+- Mandatory value:        Time = 0-255 (in seconds), action = 0
+
+A Service Class 1 facsimile DCE shall provide a DTE inactivity timer that allows the DCE to break away from an unsuccessful connection attempt at any stage of a facsimile transfer. The DTE inactivity timer only works while the DCE is off-hook.
+
+The <time> parameter indicates the DTE inactivity timeout in seconds. The required timeout is 1 to 255 seconds. The value of 0 indicates that timeout is disabled. Any values greater than 255 are optional values for the DCE manufacturer. The <action> parameter has two meanings.
+
+The inactivity timer starts when the DCE has taken some action that requires DTE response. If the DTE does respond, the DCE shall reset the inactivity timer. Tables 8 and 9 define these sets of events.
+
+TABLE 8/T.31
+
+#### **Inactivity timer start and stop events**
+
+| On-line state                    | Start timer event                                    | Stop timer event         |
+|----------------------------------|------------------------------------------------------|--------------------------|
+| Waiting for a command            | DCE sends final result code                          | DTE sends AT or "at"     |
+| Waiting for transmit data        | DCE sends CONNECT after +FTM or +FTH command         | DTE sends data           |
+| Waiting for transmit data        | DCE sends <DC1> or sets V.24 Ckt 106 ON              | DTE sends data           |
+| Waiting to deliver received data | DCE sends <DC3> after +FRM or +FRH command           | DTE sends <DC1>          |
+| Waiting to deliver received data | DTE sets V.24 Ckt 133 OFF after +FRM or +FRH command | DTE sets V.24 Ckt 133 ON |
+
+TABLE 9/T.31
+
+#### **DCE responses to DTE inactivity**
+
+| <action> | Description                                                                                                                                                                        |
+|----------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| 0        | Upon timeout, the DCE shall go on-hook, executing an implied ATH command; then reset to +FCLASS = 0 if +FCLASS = 0 is supported by the DCE                                         |
+| 1        | Upon timeout, the DCE shall only go on-hook. This feature is used to detect possible system failure, when either no line or DTE activity has occurred for a minimum amount of time |
+
+# **Annex A**
+
+## **Interworking with existing facsimile DTE**
+
+(This annex forms an integral part of this Recommendation)
+
+The DCE shall implement additional syntax for the V.25 *ter* commands referred to in Table A.1, in order to interwork with existing Facsimile DTE which use the +F syntax commands. See also Table A.2.
+
+TABLE A.1/T.31
+
+### **Common functions in Recommendations V.25 *ter* and T.31**
+
+| Function     | V.25 <i>ter</i> command | V.25 <i>ter</i> reference | +F syntax Command | Recommended implementation      |
+|--------------|-------------------------|---------------------------|-------------------|---------------------------------|
+| Modem ID     | +GMI                    | 6.1.4                     | +FMI              | +FMI as same definition as +GMI |
+| Model ID     | +GMM                    | 6.1.5                     | +FMM              | +FMM as same definition as +GMM |
+| Revision ID  | +GMR                    | 6.1.6                     | +FMR              | +FMR as same definition as +GMR |
+| Port rate    | +IPR                    | 6.2.10                    | +FPR              | See Table A.2                   |
+| Flow control | +IFC                    | 6.2.12                    | +FLO              | See Table A.2                   |
+
+TABLE A.2/T.31
+
+### **+F Syntax command implementation**
+
+| DTE command                                         | DCE action               | Description or notes                                           |
+|-----------------------------------------------------|--------------------------|----------------------------------------------------------------|
+| +FMI?                                               | Execute +GMI?            | Report DCE Manufacturer ID                                     |
+| +FMM?                                               | Execute +GMM?            | Report DCE model ID                                            |
+| +FMR?                                               | Execute +GMR?            | Report DCE revision ID                                         |
+| +FLO = 0                                            | Execute +IFC = 0,0       | Turn off flow control                                          |
+| +FLO = 1                                            | Execute +IFC = 1,1       | Select DC1/DC3 flow control                                    |
+| +FLO = 2                                            | Execute +IFC = 2,2       | Select Ckt 106/133 flow control                                |
+| +FPR = 0                                            | Execute +IPR = 0         | Select automatic rate detection                                |
+| +FPR = 1                                            | Execute +IPR = 2400      | Set DTE-DCE to 2400 bit/s                                      |
+| +FPR = 2                                            | Execute +IPR = 4800      | Set DTE-DCE rate to 4800 bit/s                                 |
+| +FPR = 4                                            | Execute +IPR = 9600      | Set DTE-DCE rate to 9600 bit/s                                 |
+| +FPR = 8                                            | Execute +IPR = 19 200    | Set DTE-DCE rate to 19 200 bit/s                               |
+| +FPR = 10                                           | Execute +IPR = 38 400    | Set DTE-DCE rate to 38 400 bit/s                               |
+| +FPR = 18                                           | Execute +IPR = 57 600    | Set DTE-DCE rate to 57 600 bit/s                               |
+| +FLO = ? (if all values listed above are supported) | Report (0,1,2)           | DCE supports DC1/DC3 and Ckt 106/133 flow control              |
+| +FPR = ? (if all values listed above are supported) | Report (0,1,2,4,8,10,18) | DCE supports 2400, 4800, 9600, 19 200, 38 400 and 57 600 bit/s |
+| +FLO? (if +IFC = 0,0)                               | Report 0                 | DTE-DCE flow control is disabled                               |
+| +FLO? (if +IFC = 1,1)                               | Report 1                 | DTE-DCE flow control is DC1/DC3                                |
+| +FLO? (if +IFC = 2,2)                               | Report 2                 | DTE-DCE flow control is V.24 Ckt 106/133                       |
+| +FLO? (all other +IFC settings)                     | Report 255               | 255 indicates invalid setting                                  |
+| +FPR? (if +IPR = 0)                                 | Report 0                 | DTE-DCE rate is automatically detected                         |
+| +FPR? (if +IFC = 2400)                              | Report 1                 | DTE-DCE rate is 2400 bit/s                                     |
+| +FPR? (if +IFC = 4800)                              | Report 2                 | DTE-DCE rate is 4800 bit/s                                     |
+| +FPR? (if +IFC = 9600)                              | Report 4                 | DTE-DCE rate is 9600 bit/s                                     |
+| +FPR? (if +IFC = 19 200)                            | Report 8                 | DTE-DCE rate is 19 200 bit/s                                   |
+| +FPR? (if +IFC = 38 400)                            | Report 10                | DTE-DCE rate is 38 400 bit/s                                   |
+| +FPR? (if +IFC = 57 600)                            | Report 18                | DTE-DCE rate is 57 600 bit/s                                   |
+| +FPR? (all other +IPR settings)                     | Report 255               | 255 indicates invalid setting                                  |
+
+# Appendix I
+
+## Service Class 1 example sessions
+
+(This appendix does not form an integral part of this Recommendation)
+
+### Example sessions – Transmission and reception of Group 3 facsimile images with Class 1 commands and responses
+
+In this subclause, examples of the interchange between the DTE and the DCE are given for various cases. Comments are interspersed to explain how various situations should be handled. The commands and responses are in CAPITAL letters, while the comments are in lower case.
+
+Refer to Recommendation T.30 for descriptions and flow charts of Group 3 Facsimile Procedures, and for timing requirements. Refer to Appendix II/T.30 for abbreviations.
+
+NOTE – All streams of data denoted by <.frame> are terminated by the <DLE> <ETX> characters (IRA 1/0, 0/3), and they are filtered as described in 6.11.
+
+### I.1 Calling sequence, transmitting a single page facsimile
+
+TABLE I.1/T.31
+
+| DTE commands                                                                             | DCE responses                                    | Local DCE action                                                                                                                 | Remote station action                                                         | Notes                                                                                                                                     |
+|------------------------------------------------------------------------------------------|--------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------|
+| AT+FCLASS = 1.0                                                                          | OK                                               | Set Class1                                                                                                                       |                                                                               |                                                                                                                                           |
+| ATD <string>                                                                             | CONNECT<br><NSF frame><br><DLE> <ETX><br>OK      | Dial and send CNG<br>Look for Rec. V.21<br>Detecte flags                                                                         | Answers<br>Sends CED, Rec. V.21<br>Sends HDLC flags<br><br>Sends NSF<br>Frame | AT+FRH = 3<br>implied by dialing with<br>+FCLASS = 1.0                                                                                    |
+| AT+FRH = 3                                                                               | CONNECT<br><CSI frame data><br><DLE> <ETX><br>OK | Detect flags<br>get CSI<br>get FCS<br>accept FCS                                                                                 | send CSI frame<br><br>check FCS                                               | frame status OK                                                                                                                           |
+| AT+FRH = 3                                                                               | CONNECT<br><DIS frame data><br><DLE> <ETX><br>OK | Detect flags<br>get DIS<br>get FCS<br>accept FCS                                                                                 | Send DIS frame<br><br>send FCS                                                | DTE must detect final<br>frame bit to anticipate<br>loss-of-carrier                                                                       |
+| AT+FRH = 3                                                                               | NO CARRIER                                       | detect loss-of-carrier                                                                                                           | drop carrier                                                                  |                                                                                                                                           |
+| AT+FTH = 3<br><br><TSI frame data><br><DLE> <ETX><br><br><DCS frame data><br><DLE> <ETX> | CONNECT<br><br>CONNECT<br><br>OK                 | send V.21 carrier<br>send flags<br>send TSI frame<br>send FCS<br>send flags<br>send DCS frame<br>send FCS, flags<br>drop carrier | detect carrier<br>detect flags<br>get TSI frame<br><br>get DCS frame          | Final frame bit clear<br>tells the DCE to expect<br>another frame.<br>Final frame bit set tells<br>the DCE not to expect<br>another frame |
+| AT+FTS = 8;<br>+FTM = 96<br><br><TCF data pattern><br><DLE> <ETX>                        | CONNECT<br><br>OK                                | wait 80 msec<br>send V.29 carrier<br><br>send TCF data<br>drop carrier                                                           | detect carrier<br><br>get TCF data                                            |                                                                                                                                           |
+
+TABLE I.1/T.31 (*end*)
+
+| DTE commands                                                   | DCE responses                                    | Local DCE action                                                                              | Remote station action                                         | Notes                            |
+|----------------------------------------------------------------|--------------------------------------------------|-----------------------------------------------------------------------------------------------|---------------------------------------------------------------|----------------------------------|
+| AT+FRH = 3                                                     | CONNECT<br><CFR frame data><br><DLE> <ETX><br>OK | detect carrier<br>detect flags<br>get CFR frame<br>check FCS<br>accept FCS                    | send V.21 carrier<br>send flags<br>send CRF frame<br>send FCS | Final frame bit set.<br>frame OK |
+| AT+FRH = 3                                                     | NO CARRIER                                       | detect loss-of-carrier                                                                        | drop carrier                                                  |                                  |
+| AT+FTM = 96<br><page image data><br><DLE> <ETX>                | CONNECT<br><br>OK                                | send V.29 carrier<br>send page data<br>drop carrier                                           | detect carrier<br>receive page                                |                                  |
+| AT+FTS = 8;<br>+FTH = 3<br><br><EOP frame data><br><DLE> <ETX> | CONNECT<br><br>OK                                | wait 80 msec<br>send V.21 carrier<br>send flags<br>send EOP frame<br>send FCS<br>drop carrier | detects carrier<br>detects flags<br>receives EOP              | final frame                      |
+| AT+FRH = 3                                                     | CONNECT<br><MCF frame data><br><DLE> <ETX><br>OK | detect carrier<br>detect flags<br>get MCF frame<br>check FCS<br>accept FCS                    | send V.21 carrier<br>send flags<br>send MCF frame<br>send FCS | Final frame bit set.<br>frame OK |
+| AT+FRH = 3                                                     | NO CARRIER                                       | detect loss-of-carrier                                                                        | drop carrier                                                  |                                  |
+| AT+FTH = 3<br><br><DCN frame><br><DLE><ETX>                    | CONNECT<br><br>OK                                | send V.21 carrier<br>send flags<br>send DCN frame<br>send FCS<br>drop carrier                 | detects carrier<br>detects flags<br>receives DCN              | final frame                      |
+| ATH0                                                           | OK                                               | Hang Up                                                                                       | hangup                                                        |                                  |
+
+### I.2 Answering and receiving a single page facsimile
+
+TABLE I.2/T.31
+
+| DTE commands                                                                      | DCE responses                    | Local DCE action                                                                                                                                                | Remote station action                                                                                     | Notes                                                                                                              |
+|-----------------------------------------------------------------------------------|----------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------|
+| AT+FCLASS = 1.0                                                                   | OK                               | Set to Class 1                                                                                                                                                  |                                                                                                           |                                                                                                                    |
+|                                                                                   | RING <-                          | detect Ringing                                                                                                                                                  | Dials [, send CNG]                                                                                        |                                                                                                                    |
+| ATA<br><br><CSI frame data><br><DLE> <ETX><br><br><DIS frame data><br><DLE> <ETX> | CONNECT<br><br>CONNECT<br><br>OK | off-hook,<br>send CED,<br>send V.21 carrier<br>send flag(s)<br>send CSI data<br>send FCS<br>send flag(s)<br>send DIS data<br>send FCS and flags<br>drop carrier | get CED,<br>detect carrier<br>detect flags<br>receive CSI<br>get FCS<br>get flags<br>get DIS<br>get flags | AT+FTH = 3 implied<br>by answering with<br>+FCLASS = 1.0.<br>not final<br>frame<br><br><br><br><br><br>final frame |
+
+TABLE I.2/T.31 (end)
+
+| DTE commands                                      | DCE responses                                             | Local DCE action                                                                 | Remote station action                                                             | Notes                                                       |
+|---------------------------------------------------|-----------------------------------------------------------|----------------------------------------------------------------------------------|-----------------------------------------------------------------------------------|-------------------------------------------------------------|
+| AT+FRH = 3                                        | CONNECT<br><TSI frame data><br><DLE> <ETX><br>OK          | detect carrier<br>detect flags<br>receive TSI<br>receive FCS<br>accept FCS       | sends V.21 carrier<br>send flags<br>send TSI frame<br>send FCS                    | frame OK                                                    |
+| AT+FRH = 3                                        | CONNECT<br><DCS frame data><br><DLE> <ETX><br>OK          | receive DCS<br>receive FCS<br>accept FCS                                         | send DCS frame<br>send FCS                                                        | final frame bit set<br>frame OK                             |
+| AT+FRH = 3                                        | NO CARRIER                                                | detect loss-of-carrier                                                           | drop carrier                                                                      | DTE did not check final<br>frame bit and issued<br>+FRH = 3 |
+| AT+FRM = 96                                       | CONNECT<br><TCF data><br><DLE> <ETX><br>NO CARRIER        | detect carrier<br>receive TCF<br>detect loss-of-carrier                          | wait 75 msec<br>send V.29 carrier<br>send TCF data<br>drop carrier                |                                                             |
+| AT+FTH = 3<br><br><CFR frame data><br><DLE> <ETX> | CONNECT<br><br>OK                                         | send V.21 carrier<br>send flags<br>send CFR frame<br>send FCS<br>drop carrier    | detects carrier<br>detects flags<br>receives CFR                                  | final frame                                                 |
+| AT+FRM = 96                                       | CONNECT<br><page image data><br><DLE> <ETX><br>NO CARRIER | detect carrier<br>receive page<br>detect loss-of-carrier                         | send V.29 carrier<br>send page data<br>drop carrier                               |                                                             |
+|                                                   | CONNECT<br><EOP frame data><br><DLE> <ETX><br>OK          | detects carrier<br>detects flags<br>receives EOP<br>receives FCS<br>accepts FCS  | waits 75 msec<br>sends V.21 carrier<br>sends flags<br>sends EOP frame<br>send FCS | frame OK                                                    |
+| AT+FRH = 3                                        | NO CARRIER                                                | detect loss-of-carrier                                                           | drops carrier                                                                     |                                                             |
+| AT+FTH = 3<br><br><MCF frame data><br><DLE> <ETX> | CONNECT<br><br>OK                                         | send V.21 carrier<br>send flags<br>send MCF frame<br>send FCS<br>drop carrier    | detect carrier<br>detect flags<br>receive MCF<br>frame                            | final frame                                                 |
+| AT+FRH = 3                                        | CONNECT<br><DCN frame data><br><DLE> <ETX><br>OK          | receives carrier<br>detects flags<br>receives DCN<br>receives FCS<br>accepts FCS | send V.21 carrier<br>send flags<br>send DCN frame<br>send FCS                     | frame OK                                                    |
+| AT+FRH = 3                                        | NO CARRIER                                                | detect loss-of-carrier                                                           | drops carrier                                                                     |                                                             |
+| ATH0                                              | OK                                                        | hangs up                                                                         |                                                                                   | end of session                                              |
+
+# Appendix II
+
+## Recommendations for DTE compatibility
+
+(This appendix does not form an integral part of this Recommendation)
+
+### II.1 Clarification of switching from HDLC reception to transmission
+
+Failure by the DTE, after receipt of a final HDLC frame in a series, to wait for the conclusion of signals from the remote (i.e. loss-of-carrier) may result in initiation of transmission before the remote facsimile device has turned off its modulator. This can result in the remote device failing to receive the entire training sequence, resulting thereby in failure to receive the entire transmission. Although such rapid switching of the direction of transmission is not prohibited by Recommendation T.30, it is not advised because of this overlap possibility.
+
+Three possible ways for the DTE to avoid overlapping transmitted and received carriers are:
+
+- a) issue an additional +FRH command and wait for the NO CARRIER result code, which indicates the loss of received signal (note that, in some cases, line noise will occur during carrier shut-off, and the DCE may deliver some data and an ERROR result code; such occurrences after reception of a frame with the “final” bit set should be ignored);
+- b) use the +FRS command to cause the DCE to wait for silence before beginning transmission; or
+- c) use the +FTS command to insert a fixed period of time before initiating transmission.
+
+### II.2 Clarification of switching transmit modulation schemes
+
+Recommendation T.30 requires that facsimile devices insert  $75 \pm 20$  milliseconds of silence when switching from transmission of one modulation scheme to another. It is the responsibility of the DTE software to specify the point at which this silent period is to be included. The +FTS command is the preferred method of implementing this silent period. For example, if the DCE has been transmitting image data in +FTM = 96 mode, after concluding the transmission with <DLE> <ETX> and receiving an OK result code, the DTE can insert 70 milliseconds of silence and switch to V.21/HDLC mode to send the post-page message by using the command string “AT+FTS = 7; +FTH = 3”.
\ No newline at end of file
diff --git a/marked/T/T-REC-T.32-199508-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/T/T-REC-T.32-199508-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..34377f03bb1b57337e3fcbb9bb9fe715af00b487
--- /dev/null
+++ b/marked/T/T-REC-T.32-199508-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:ec845ef5dd3192986efb6000c40f809ed55794ab672de98ccaa29bae4f70c278
+size 8401
diff --git a/marked/T/T-REC-T.32-199508-I_PDF-E/c99bf3a0530a3e58f5f2d2790ba7441b_img.jpg b/marked/T/T-REC-T.32-199508-I_PDF-E/c99bf3a0530a3e58f5f2d2790ba7441b_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..2adcc2277fa0143598a6a273c0928da58b1ab14a
--- /dev/null
+++ b/marked/T/T-REC-T.32-199508-I_PDF-E/c99bf3a0530a3e58f5f2d2790ba7441b_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:9ce18bb37568bda908b1af900b9e45a1f2f00bb88cdefcd623071c399fd65e2c
+size 76549
diff --git a/marked/T/T-REC-T.33-199607-I_PDF-E/042733dc5e8e7f5f30b60adba3266cde_img.jpg b/marked/T/T-REC-T.33-199607-I_PDF-E/042733dc5e8e7f5f30b60adba3266cde_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..27b67a5bfec85e408b8f265a72d147bc4be533ae
--- /dev/null
+++ b/marked/T/T-REC-T.33-199607-I_PDF-E/042733dc5e8e7f5f30b60adba3266cde_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:0e42c4e45809304719b493d8d3c18d80ffdfe08dc2f997120bf75d1195c5a339
+size 61150
diff --git a/marked/T/T-REC-T.33-199607-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/T/T-REC-T.33-199607-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..653de272961a40ec25eb914003b793fd98e8729e
--- /dev/null
+++ b/marked/T/T-REC-T.33-199607-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:6d4392fa7c206984f7665b03d9fdb25ee9fce6dbed29323bdc025668ca8fea2f
+size 8294
diff --git a/marked/T/T-REC-T.33-199607-I_PDF-E/2ee59e629035d641140e55f4d215b0d7_img.jpg b/marked/T/T-REC-T.33-199607-I_PDF-E/2ee59e629035d641140e55f4d215b0d7_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..c7e38554d57dd69a7c8a8e0b27536682d69c9f6b
--- /dev/null
+++ b/marked/T/T-REC-T.33-199607-I_PDF-E/2ee59e629035d641140e55f4d215b0d7_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:451fa6f827c0a59a951f1403aaa1c560fb41606245802db50b156fea3b060ada
+size 41794
diff --git a/marked/T/T-REC-T.33-199607-I_PDF-E/af7916c89a458fdab6c3f443217388ae_img.jpg b/marked/T/T-REC-T.33-199607-I_PDF-E/af7916c89a458fdab6c3f443217388ae_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..6904ccb45dbb8547d2e35f3ed44dfae823d78530
--- /dev/null
+++ b/marked/T/T-REC-T.33-199607-I_PDF-E/af7916c89a458fdab6c3f443217388ae_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:904a4472f1adbe91b4236a84c965b7655a7879d93dbd343f5118a6bf3333cb56
+size 94253
diff --git a/marked/T/T-REC-T.33-199607-I_PDF-E/ebff22fb5dd6f50a90e44dca0f82f285_img.jpg b/marked/T/T-REC-T.33-199607-I_PDF-E/ebff22fb5dd6f50a90e44dca0f82f285_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..a69951315bc359df48cdc6d779485b171e80e2d6
--- /dev/null
+++ b/marked/T/T-REC-T.33-199607-I_PDF-E/ebff22fb5dd6f50a90e44dca0f82f285_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:298354236ffef269406943dbdeceb022351a81892d996ccdda25e4df0119a0d6
+size 79099
diff --git a/marked/T/T-REC-T.33-199607-I_PDF-E/raw.md b/marked/T/T-REC-T.33-199607-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..87e1706959766681aa6c7803290963f1cde95ce1
--- /dev/null
+++ b/marked/T/T-REC-T.33-199607-I_PDF-E/raw.md
@@ -0,0 +1,457 @@
+
+
+![ITU logo: a globe with the letters ITU inside, and a lightning bolt striking the globe.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg)
+
+ITU logo: a globe with the letters ITU inside, and a lightning bolt striking the globe.
+
+INTERNATIONAL TELECOMMUNICATION UNION
+
+# ITU-T
+
+TELECOMMUNICATION  
+STANDARDIZATION SECTOR  
+OF ITU
+
+# T.33
+
+(07/96)
+
+SERIES T: TERMINAL EQUIPMENTS AND  
+PROTOCOLS FOR TELEMATIC SERVICES
+
+---
+
+**Facsimile routing utilizing  
+the Subaddress**
+
+ITU-T Recommendation T.33
+
+(Previously «CCITT Recommendation»)
+
+---
+
+# FOREWORD
+
+The ITU-T (Telecommunication Standardization Sector) is a permanent organ of the International Telecommunication Union (ITU). The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis.
+
+The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics.
+
+The approval of Recommendations by the Members of the ITU-T is covered by the procedure laid down in WTSC Resolution No. 1 (Helsinki, March 1-12, 1993).
+
+ITU-T Recommendation T.33 was prepared by ITU-T Study Group 8 (1993-1996) and was approved under the WTSC Resolution No. 1 procedure on the 3rd of July 1996.
+
+# --- NOTE
+
+In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+© ITU 1996
+
+All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU.
+
+# CONTENTS
+
+|                                                                    | <i>Page</i> |
+|--------------------------------------------------------------------|-------------|
+| 1 Introduction and scope .....                                     | 1           |
+| 2 Normative References .....                                       | 1           |
+| 3 Definitions.....                                                 | 2           |
+| 4 Representation of Subaddress .....                               | 2           |
+| 4.1 Rules for use of delimiters in Subaddress.....                 | 2           |
+| 4.2 Representation of Subaddress Facsimile Information Field ..... | 2           |
+| 5 Encoding of the Subaddress Facsimile Information Field .....     | 3           |
+| 5.1 Example of Subaddress FIF construction .....                   | 3           |
+| 6 Decoding of the Subaddress Facsimile Information Field .....     | 4           |
+| Annex A – Description of Backus-Naur Notation.....                 | 6           |
+| Annex B – Outline of the Facsimile Routing Procedure .....         | 6           |
+| B.1 Definitions .....                                              | 6           |
+| B.2 Procedure for Facsimile Routing .....                          | 7           |
+| B.3 Flow diagram of Routing Procedure.....                         | 8           |
+| Appendix I – Representation of Facsimile Address .....             | 10          |
+| I.1 Representation of Facsimile Address.....                       | 10          |
+| I.2 Representation of Facsimile Address on printed materials.....  | 10          |
+| Appendix II –Examples of Facsimile Address and Subaddress .....    | 11          |
+| II.1 Examples of Facsimile Address.....                            | 11          |
+| II.2 Additional examples of Subaddress FIF coding .....            | 11          |
+
+# **SUMMARY**
+
+This Recommendation defines application rules for the routing of Group 3 facsimile messages using the Subaddress (SUB) signal as defined in Recommendation T.30. The aspects which are addressed include placement of telephone address components (phone extensions and secondary dialling numbers) within the SUB frame, encoding and decoding rules, and an outline of the facsimile routing procedure.
+
+## **KEYWORDS**
+
+Facsimile, Group 3, Routing.
+
+# FACSIMILE ROUTING UTILIZING THE SUBADDRESS
+
+(Geneva, 1996)
+
+# 1 Introduction and scope
+
+There is a requirement within the marketplace to provide reliable routing of facsimile messages which are received by a Group 3 facsimile terminal and then require further routing to reach the final recipient. Environments where this requirement exists include Local Area Networks, facsimile mailbox systems and facsimile services. Related applications may entail use of telephone extensions or secondary telephone numbers to enable this routing. This Recommendation is intended to address these requirements.
+
+This Recommendation defines optional encoding methods for the routing of Group 3 facsimile messages using the Subaddress (SUB) signal as defined in the Recommendation T.30. This Recommendation addresses the following aspects of facsimile message routing within the Group 3 facsimile procedure:
+
+- Definition of a Subaddress representation whose contents may include phone extensions, a phone number or a combination of these elements.
+- Placement, encoding and decoding of telephone number and extension information within the Facsimile Information Frame of the Subaddress signal.
+- Outline and a flow diagram of a facsimile routing procedure.
+
+Definitions of the method and user interface to be used for the entry of telephone number and subaddress information by an operator of a facsimile device or facsimile software are beyond the scope of this Recommendation. The methods by which a facsimile message may be routed after reception by a facsimile terminal are also beyond the scope of this Recommendation.
+
+# 2 Normative References
+
+The following Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision: all users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published.
+
+- CCITT Recommendation E.123 (1988), *Notation for national and international phone Numbers.*
+- CCITT Recommendation E.164 (1991), *Numbering plan for the ISDN era.*
+- CCITT Recommendation T.6 (1988), *Facsimile coding schemes and coding control functions for Group 4 facsimile apparatus.*
+- ITU-T Recommendation T.4 (1993), *Standardization of Group 3 facsimile apparatus for document transmission.*
+- ITU-T Recommendation T.30 (1993), *Procedures for document facsimile transmission in the general switched telephone network.*
+- CCITT Recommendation T.434 (1992), *Binary file transfer format for the telematic services.*
+- ITU-T Recommendation F.551 (1993), *Service Recommendation for the telematic file transfer within Telefax 3, Telefax 4, teletex services and messaging handling services.*
+
+# 3 Definitions
+
+For the purposes of this Recommendation, the following definitions apply:
+
+**3.1 telephone number:** This is a multiple digit string with dial modifiers as defined in Recommendation E.123.
+
+**3.2 extension:** For the purposes of this Recommendation, this is defined as string of one or more digits representing a unique destination assigned to a specific person for receipt of facsimile messages. This is commonly known as a “phone extension”.
+
+**3.3 telephone address:** This is an address entity which shall include a telephone number and may include one or more extensions.
+
+**3.4 second stage telephone number:** This is a telephone number which is reserved for use after the initial dialling of the telephone number in the facsimile procedure.
+
+**3.5 subaddress signal (SUB):** This is a signal defined in Recommendation T.30 which is intended to provide further routing in the Group 3 facsimile procedure.
+
+**3.6 subaddress content:** This is information content which may be transferred using the Subaddress signal (SUB) within Group 3 facsimile Recommendation T.30. For purposes of this Recommendation, the information content to be transferred may consist of one or more telephone extensions, a second stage dial number or a combination of these elements.
+
+**3.7 subaddress facsimile information field:** This is a character string whose size, encoding and permissible characters are defined generically in Recommendation T.30. As of the publication date of this Recommendation, these permissible characters are numeric digits 0-9 and the \*, # and SPACE characters and the total length of the Subaddress FIF is 20 octets. The SPACE character is reserved for use in padding to fill up to the full permitted length of the subaddress.
+
+**3.8 facsimile message:** This is any information which can be communicated between Group 3 facsimile terminals per Recommendations T.4 and T.30 and optionally per Recommendations T.6, T.30, T.434 and F.551.
+
+**3.9 BNF:** All objects defined in this Recommendation are described using a Backus Naur Form (BNF) style of grammar. A definition of these production rules is contained within Annex A.
+
+# 4 Representation of Subaddress
+
+## 4.1 Rules for use of delimiters in Subaddress
+
+For consistency with current trends in use of telephone keypad characters as expressed in Recommendation E.164 and other ITU-T Recommendations, the # character shall be used within the subaddress FIF as a delimiter between multiple extensions and two consecutive # characters (i.e. ##) shall be used as a delimiter between telephone addresses. The \* character shall be reserved for user applications.
+
+For compact representation, the first character to be represented in a Subaddress FIF shall be the first numeric digit for the case of an extension and a single # for the case of a telephone address.
+
+## 4.2 Representation of Subaddress Facsimile Information Field
+
+The Subaddress Content to be placed within the Subaddress Facsimile Information Field (FIF) shall be represented as defined in this subclause for compliance with this Recommendation. The representation of the Subaddress Content and its components is provided in BNF form.
+
+The information content of the Subaddress FIF may be composed of the following components which were defined in clause 3:
+
+<Extension> ::= Extension
+
+<Second\_Stage\_Number> ::= Second Stage Telephone Number
+
+The combination of a Second Stage Telephone Number and the extensions associated with that telephone number make up a Telephone Address, which is signified in the BNF notation below as a Complete Address. One or more occurrences of these components may be encoded within the Subaddress FIF per the rules defined below.
+
+### **Components**
+
+<Digit> ::= 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | \*  
+<Extension> ::= <Digit>{<Digit>}  
+<Multi\_Extension> ::= <Extension>{#<Extension>}  
+<Second\_Stage\_Number> ::= <Digit>{<Digit>}  
+<Complete\_Address> ::= <Second\_Stage\_Number>{#<Multi\_Extension>}  
+<Multi\_Complete\_Address> ::= <Complete\_Address>{##<Complete\_Address>}  
+<First\_Address> ::= <Multi\_Extension> | #<Complete\_Address>
+
+### **Subaddress FIF Representation**
+
+<Subaddress> ::= <First\_Address>{##<Multi\_Complete\_Address>}
+
+# **5 Encoding of the Subaddress Facsimile Information Field**
+
+This clause defines how to encode and place Subaddress Content within the Facsimile Information Field (FIF) of the SUB signal within the Group 3 facsimile procedure. The sending facsimile terminal shall build the FIF for the SUB signal. The routing information to be placed within the Subaddress FIF shall be in the form of Subaddress Content as defined in clause 4.
+
+The octets of the Subaddress FIF shall be coded per Table 3/T.30. The Subaddress Content shall be right justified and placed in the least significant octets of the SUB FIF frame. Per Recommendation T.30, the unused octets in the FIF shall be padded from the left and filled with the "space" character. The least significant bit of the least significant digit shall be the first bit transmitted.
+
+## **5.1 Example of Subaddress FIF construction**
+
+An example is provided to illustrate the process of constructing a Subaddress FIF and the order of transmission of SUB octets. This example assumes a fixed length FIF of 20 octets, where padding characters used to fill up the SUB FIF to its full length.
+
+In the sample case, suppose that the Subaddress Content to be placed in the FIF frame is as follows:
+
+#1234567890#1234
+
+In placing the Subaddress content into the FIF octets, the SPACE character (shown below as "S") shall be used to pad from the left as shown in Table 1:
+
+TABLE 1/T.33
+
+Placement of octets in Subaddress FIF
+
+|   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
+|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
+| S | S | S | S | # | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 0 | # | 1 | 2 | 3 | 4 |
+|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
+
+In hexadecimal representation, this can be represented as shown below in Figure 1:
+
+![Diagram showing the order of transmission of SUB FIF octets. A sequence of 16 octets is shown, indexed 20 to 34. The first octet (index 34) is labeled 'Least significant octet' and the last octet (index 20) is labeled 'Most significant octet'. Below the sequence, two boxes show the binary representation of the first and last octets. The first octet (index 34) is shown as 00110100, with the first bit transmitted (the leftmost bit) indicated. The last octet (index 20) is shown as 00100000, with the last bit transmitted (the rightmost bit) indicated. The diagram also includes references to (hex) and (binary) representations and a standard reference T0825320-96/d01.](2ee59e629035d641140e55f4d215b0d7_img.jpg)
+
+Most significant octet
+
+Least significant octet
+
+20 20 20 20 23 31 32 33 34 35 36 37 38 39 40 23 31 32 33 34
+
+(hex)
+
+(binary)
+
+00100000
+
+Last bit transmitted
+
+(hex)
+
+(binary)
+
+00110100
+
+First bit transmitted
+
+T0825320-96/d01
+
+Diagram showing the order of transmission of SUB FIF octets. A sequence of 16 octets is shown, indexed 20 to 34. The first octet (index 34) is labeled 'Least significant octet' and the last octet (index 20) is labeled 'Most significant octet'. Below the sequence, two boxes show the binary representation of the first and last octets. The first octet (index 34) is shown as 00110100, with the first bit transmitted (the leftmost bit) indicated. The last octet (index 20) is shown as 00100000, with the last bit transmitted (the rightmost bit) indicated. The diagram also includes references to (hex) and (binary) representations and a standard reference T0825320-96/d01.
+
+FIGURE 1/T.33  
+Order of transmission of SUB FIF octets
+
+According to the rules of Recommendation T.30, the least significant octet (<34> or (0011 0100) in this example) is the first octet transmitted and the least significant bit of the least significant octet is transmitted first. In turn, the most significant octet (<20> or (0010 0000) in this example) is the last octet transmitted.
+
+# 6 Decoding of the Subaddress Facsimile Information Field
+
+If subaddress information has been exchanged during the Group 3 facsimile procedure, the receiving facsimile terminal shall receive the optional SUB signal during T.30 negotiations. The Facsimile Information Field for the SUB signal shall contain the Subaddress octets. The Subaddress Content may be extracted from the SUB FIF by processing octets from left to right, ignoring leading "space" characters used for padding.
+
+The Subaddress Content may then be decoded for routing purposes. As defined in 4.2, the Subaddress Content may consist of one or more phone extensions, one or more second stage phone numbers or combinations of these components. Where the subaddress FIF includes phone extensions, it may be assumed that these extensions are associated with the preceding telephone number. Where the first components in the SUB FIF are one or more extensions, these are associated with the previously dialled telephone number. The formal representation of Subaddress Content has been defined in 4.2. The rules for the decoding of Subaddress Content shall include the following:
+
+- The first non-SPACE character to be represented in a Subaddress FIF shall be the first numeric digit for the case of an extension and a single # for the case of a telephone address.
+- A single # is the delimiter between multiple extensions.
+- Two consecutive # characters are the delimiters between multiple addresses.
+
+A state diagram for the decoding of the Subaddress FIF is shown in Figure 2:
+
+![State diagram for decoding Subaddress FIF. The diagram shows a flow from START to Consume Leading Spaces, then to a decision diamond 'Next Char'. From 'Next Char', the flow branches based on input: '#' leads to 'Consume #', 'char' leads to 'Collect Ext char', and 'eoi' leads to 'End'. 'Consume #' leads to another 'Next Char' diamond. This diamond branches: 'char' leads to 'Collect SST char', which loops back to the first 'Next Char' diamond; '#' leads to 'Consume # and Terminate SST', which loops back to the first 'Next Char' diamond; 'eoi' leads to 'Terminate SST', which leads to 'End'. 'Collect Ext char' leads to a third 'Next Char' diamond. This diamond branches: 'char' loops back to 'Collect Ext char'; '#' leads to 'Consume # and Terminate Ext', which loops back to the first 'Next Char' diamond; 'eoi' leads to 'Terminate Ext', which leads to 'End'.](ebff22fb5dd6f50a90e44dca0f82f285_img.jpg)
+
+```
+
+graph TD
+    START([START]) --> CLS[Consume Leading Spaces]
+    CLS --> N1{Next Char}
+    N1 -- '#' --> C1[Consume #]
+    N1 -- 'char' --> CE1[Collect Ext char]
+    N1 -- 'eoi' --> E1([End])
+    C1 --> N2{Next Char}
+    N2 -- 'char' --> CS1[Collect SST char]
+    CS1 --> N1
+    N2 -- '#' --> C2[Consume # and Terminate SST]
+    C2 --> N1
+    N2 -- 'eoi' --> T1[Terminate SST]
+    T1 --> E1
+    CE1 --> N3{Next Char}
+    N3 -- 'char' --> CE1
+    N3 -- '#' --> C3[Consume # and Terminate Ext]
+    C3 --> N1
+    N3 -- 'eoi' --> T2[Terminate Ext]
+    T2 --> E1
+  
+```
+
+(Note) T0824060-95/d02
+
+State diagram for decoding Subaddress FIF. The diagram shows a flow from START to Consume Leading Spaces, then to a decision diamond 'Next Char'. From 'Next Char', the flow branches based on input: '#' leads to 'Consume #', 'char' leads to 'Collect Ext char', and 'eoi' leads to 'End'. 'Consume #' leads to another 'Next Char' diamond. This diamond branches: 'char' leads to 'Collect SST char', which loops back to the first 'Next Char' diamond; '#' leads to 'Consume # and Terminate SST', which loops back to the first 'Next Char' diamond; 'eoi' leads to 'Terminate SST', which leads to 'End'. 'Collect Ext char' leads to a third 'Next Char' diamond. This diamond branches: 'char' loops back to 'Collect Ext char'; '#' leads to 'Consume # and Terminate Ext', which loops back to the first 'Next Char' diamond; 'eoi' leads to 'Terminate Ext', which leads to 'End'.
+
+SST Second Stage Telephone Number  
+ Ext Phone Extension  
+ eoi End of Input
+
+NOTE – Implementors may check the validity of the collected address information from the Subaddress FIF frame.
+
+FIGURE 2/T.33  
+ State diagram for decoding Subaddress FIF
+
+# Annex A
+
+## Description of Backus-Naur Notation
+
+(This annex forms an integral part of this Recommendation)
+
+The following provides a description of the Backus-Naur style syntax which is used in the body of this Recommendation.
+
+| Symbol  | Description of use                                                                 |
+|---------|------------------------------------------------------------------------------------|
+| literal | A token (or component) is noted by a literal.                                      |
+| ::=     | This is the production assignment operator.                                        |
+|         | This symbol is used to separate alternative tokens or groups of tokens.            |
+| < >     | A non-terminal token is noted by a literal enclosed by the “<” and “>” characters. |
+| [ ]     | An optional token or group of tokens is enclosed by the “[” and “]” characters.    |
+| { }     | A group of tokens enclosed in “{” and “}” may be repeated 0, 1 or more times.      |
+
+# Annex B
+
+## Outline of the Facsimile Routing Procedure
+
+(This annex forms an integral part of this Recommendation)
+
+This annex provides an outline of a facsimile routing procedure utilizing the subaddress for informative purposes.
+
+## B.1 Definitions
+
+The following signals used during Group 3 facsimile negotiations are referenced in this annex. The signals are defined in Recommendation T.30.
+
+|     |                               |
+|-----|-------------------------------|
+| DCS | Digital Command Signal        |
+| DIS | Digital Identification Signal |
+| DTC | Digital Transmit Command      |
+| FIF | Facsimile Information Field   |
+| SUB | Subaddress                    |
+
+Other terms used in this annex are defined below.
+
+**B.1.1 facsimile address:** A Facsimile Address shall be defined as the combination of a facsimile telephone number and an optional subaddress. A representation of the facsimile address is defined in I.1.
+
+## **B.2 Procedure for Facsimile Routing**
+
+The procedure described in this annex utilizes the subaddress (SUB) signal and the Facsimile Address as defined within this annex for purposes of routing facsimile messages beyond the called facsimile terminal. A flow diagram of this procedure is contained in this annex.
+
+When routing via this procedure is desired, the operator of the calling facsimile device or facsimile software shall enter the Facsimile Address or its components by some means. The facsimile terminal or software shall parse the Facsimile Address into its components if required, using the telephone number to dial the remote facsimile terminal and reserving the Subaddress Content to build the Facsimile Information Field (FIF) for a Subaddress (SUB) signal.
+
+The sending facsimile terminal shall build the FIF for the SUB signal, converting the subaddress as entered by the operator into the FIF. The SUB as contained within the Facsimile Address shall be placed in the least significant octets of the SUB FIF frame (right justified) and then padded on the left by adding SPACE characters as required to fill the remaining octets of the FIF.
+
+During the Phase B identification of capabilities, if bit 49 of the DIS/DTC is set, indicating that the receiving machine supports subaddressing, the optional SUB signal may be sent preceding the DCS and bit 49 of the DCS should be set (for fax terminals which comply with Recommendation T.30 of 1995 or later). The FIF which follows the SUB signal shall contain the Subaddress octets, where the least significant bit of the least significant octet shall be the first bit transmitted. If bit 49 of the DIS/DTC is not set by the called fax terminal, this indicates that the subaddress capability is not supported. This is an exception condition when the calling device is attempting to transmit with a recipient whose facsimile address includes a subaddress. The action to be taken in this case shall be manufacturer specific. The calling terminal may optionally issue a DCN signal and disconnect the line in this situation. The manufacturer may alternatively elect to support a "Subaddress Override" capability which can be specified by the operator. As indicated by the flowchart in B.3, if the "Subaddress Override" has been specified by the operator, the calling terminal may issue a DCS signal (and other optional signals excluding the SUB) and continue the facsimile procedure.
+
+If subaddress information has been exchanged during the facsimile procedure, upon completion of the fax transmission, the receiving facsimile terminal or system shall store both the facsimile message and the subaddress. The subaddress may then be used as a means to identify the intended recipient or recipients for the message. This can be accomplished by parsing the Subaddress FIF to obtain its components per the procedure described in clause 6. The components shall consist of one or more phone extensions, second stage dialling numbers, or complete addresses, which are combinations of these components. These components have been defined in clause 4. The actions to be taken by the receiving facsimile terminal or system upon receipt of the Subaddress information are application specific. The means by which routing may be accomplished are beyond the scope of this procedure.
+
+## B.3 Flow diagram of Routing Procedure
+
+See Figure B.1.
+
+![Flow diagram of Routing Procedure showing Calling station and Called Station processes.](042733dc5e8e7f5f30b60adba3266cde_img.jpg)
+
+The flow diagram illustrates the routing procedure for a calling station and a called station. The process begins with the 'Calling station' where an operator enters a fax address. A decision is made on whether a SUB (Subaddress) is present. If 'No', the process proceeds to a 'Valid SUB?' decision. If 'Yes', it proceeds to 'Parse address, Store Phone no. and SUB'. From 'Valid SUB?', if 'No', it loops back to the 'SUB Present?' decision. If 'Yes', it proceeds to 'Build SUB FIF', then 'Dial Phone No.', and finally 'Phase A Procedure', leading to connector 'B'. The 'Called Station' process starts with 'Answer Phone', followed by 'Phase A Procedure', leading to connector 'B1'. The document identifier 'T0824070-95/d03' is located at the bottom right of the diagram area.
+
+```
+graph TD
+    subgraph Calling_station [Calling station]
+        A[Operator Enters Fax Address] --> B{SUB Present?}
+        B -- No --> C{Valid SUB?}
+        B -- Yes --> D[Parse address, Store Phone no. and SUB]
+        C -- No --> B
+        C -- Yes --> E[Build SUB FIF]
+        E --> F[Dial Phone No.]
+        F --> G[Phase A Procedure]
+        G --> H((B))
+    end
+
+    subgraph Called_Station [Called Station]
+        I[Answer Phone] --> J[Phase A Procedure]
+        J --> K((B1))
+    end
+
+    H --- K
+```
+
+T0824070-95/d03
+
+Flow diagram of Routing Procedure showing Calling station and Called Station processes.
+
+FIGURE B.1/T.33  
+Routing Procedure using Subaddress where calling station wishes to transmit
+
+![Flowchart of the Routing Procedure using Subaddress where calling station wishes to transmit. The diagram shows two parallel processes: one for the Calling Station and one for the Called Station. The Calling Station process starts with a start node 'B', followed by 'Begin Phase B', 'Receive DIS', and a decision 'Bit 49 of DIS Set?'. If 'Yes', it transmits 'SUB, Optional Signals & DCS'. If 'No', it goes to a dashed decision 'SUB Override?'. If 'Yes', it transmits 'DCS, (not SUB)'. If 'No', it goes to end node 'E'. Both paths lead to 'Complete Facsimile Procedure', followed by end node 'E'. From 'E', a dashed box contains 'xmt DCN' and 'Disconnect the Line'. The Called Station process starts with start node 'B1', followed by 'Begin Phase B (Send DIS)', 'RCV SUB, DCS, etc.', 'Store SUB FIF', 'Complete Facsimile Procedure', 'Store Facsimile Message', and 'Route Message'.](af7916c89a458fdab6c3f443217388ae_img.jpg)
+
+```
+
+graph TD
+    subgraph Calling_Station [Calling Station]
+        B((B)) --> B1[Begin Phase B]
+        B1 --> RDIS[Receive DIS]
+        RDIS --> D1{Bit 49 of DIS Set?}
+        D1 -- Yes --> T1[xmt SUB, Optional Signals & DCS]
+        D1 -- No --> D2{SUB Override?}
+        D2 -- Yes --> T2[xmt DCS, (not SUB)]
+        D2 -- No --> E1((E))
+        T1 --> CFP1[Complete Facsimile Procedure]
+        T2 --> CFP1
+        CFP1 --> E1
+        E1 --> DCN[xmt DCN]
+        DCN --> DCL[Disconnect the Line]
+    end
+
+    subgraph Called_Station [Called Station]
+        B1_1((B1)) --> B1_2[Begin Phase B (Send DIS)]
+        B1_2 --> RCV[RCV SUB, DCS, etc.]
+        RCV --> SIF[Store SUB FIF]
+        SIF --> CFP2[Complete Facsimile Procedure]
+        CFP2 --> SSM[Store Facsimile Message]
+        SSM --> RM[Route Message]
+    end
+
+```
+
+T0824080-95/d04
+
+Flowchart of the Routing Procedure using Subaddress where calling station wishes to transmit. The diagram shows two parallel processes: one for the Calling Station and one for the Called Station. The Calling Station process starts with a start node 'B', followed by 'Begin Phase B', 'Receive DIS', and a decision 'Bit 49 of DIS Set?'. If 'Yes', it transmits 'SUB, Optional Signals & DCS'. If 'No', it goes to a dashed decision 'SUB Override?'. If 'Yes', it transmits 'DCS, (not SUB)'. If 'No', it goes to end node 'E'. Both paths lead to 'Complete Facsimile Procedure', followed by end node 'E'. From 'E', a dashed box contains 'xmt DCN' and 'Disconnect the Line'. The Called Station process starts with start node 'B1', followed by 'Begin Phase B (Send DIS)', 'RCV SUB, DCS, etc.', 'Store SUB FIF', 'Complete Facsimile Procedure', 'Store Facsimile Message', and 'Route Message'.
+
+FIGURE B.1/T.33 (*concluded*)  
+**Routing Procedure using Subaddress where  
+calling station wishes to transmit**
+
+# Appendix I
+
+## Representation of Facsimile Address
+
+(This appendix does not form an integral part of this Recommendation)
+
+## I.1 Representation of Facsimile Address
+
+A Facsimile Address may be represented as follows, using terms whose syntax are defined in the main body of this Recommendation and in normative references:
+
+**Facsimile Address** ::= <Telephone Number>([#] | [#<Subaddress>])
+
+## I.2 Representation of Facsimile Address on printed materials
+
+On printed materials, the Facsimile Address which includes a subaddress may be represented as follows:
+
+**Facsimile Address** ::= <Telephone Number>#<subaddress>
+
+where:
+
+- The Telephone Number shall be printed in accordance with Recommendation E.123.
+- The terminator of the telephone number shall be #, as specified in Recommendation E.123.
+- The subaddress may contain characters up to the total length of the Subaddress FIF. The permissible characters for the subaddress are defined in Recommendation T.30.
+
+# Appendix II
+
+## Examples of Facsimile Address and Subaddress
+
+(This appendix does not form an integral part of this Recommendation)
+
+The purpose of this appendix is to provide examples for the printing of a facsimile address and examples of the coding of Subaddress content.
+
+## II.1 Examples of Facsimile Address
+
+Examples of a Facsimile Address follow, showing the address as it could appear on printed materials and the coding of Subaddress FIF Content. Please note that the full Subaddress FIF shall be padded from the left with the SPACE character to fill the length for the field.
+
+| Example                                      | Printed Facsimile Address | Subaddress FIF Content |
+|----------------------------------------------|---------------------------|------------------------|
+| Phone number plus extension                  | +1-203-234-2222#1234      | 1234                   |
+| Phone number plus secondary Telephone Number | +1-203-234-2222##234-4444 | #2344444               |
+
+## II.2 Additional examples of Subaddress FIF coding
+
+Additional examples of coding for the Subaddress FIF Content are shown below. Please note that the full Subaddress FIF shall be padded from the left with the SPACE character to fill the length for the field.
+
+| Example                                               | Subaddress FIF Content |
+|-------------------------------------------------------|------------------------|
+| Multiple extensions                                   | 1234#5678#8910         |
+| Secondary telephone number plus two extensions        | #6174444100#1234#567   |
+| Two extensions followed by secondary telephone number | 1234#5678##2032223     |
+| Two secondary telephone numbers                       | #2037445555##6446666   |
\ No newline at end of file
diff --git a/marked/T/T-REC-T.330-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/T/T-REC-T.330-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..66412856f54ae0b24854202e8f031f6a04b88ee0
--- /dev/null
+++ b/marked/T/T-REC-T.330-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:a7cafe25d563af62a326eb0e9930129524893e0fb16cb431aacd25f8ed54ed31
+size 7392
diff --git a/marked/T/T-REC-T.330-198811-I_PDF-E/34f788b0e5bc8af774fa5561c22e6d01_img.jpg b/marked/T/T-REC-T.330-198811-I_PDF-E/34f788b0e5bc8af774fa5561c22e6d01_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..77a6da3883ac40eb86e35309e8d6102d4af1f75a
--- /dev/null
+++ b/marked/T/T-REC-T.330-198811-I_PDF-E/34f788b0e5bc8af774fa5561c22e6d01_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:c3e11bf2225748a96a36c2663748643bc0c2a2091b0c9ead6fa039c18db65dce
+size 20051
diff --git a/marked/T/T-REC-T.330-198811-I_PDF-E/4801720824e4b5e2361a5564f91cfb70_img.jpg b/marked/T/T-REC-T.330-198811-I_PDF-E/4801720824e4b5e2361a5564f91cfb70_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..a9bdf05ac3c19d479b4c2713c80696baffdb77c4
--- /dev/null
+++ b/marked/T/T-REC-T.330-198811-I_PDF-E/4801720824e4b5e2361a5564f91cfb70_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:ae1eea4345dc7f77bdf5b412069067dcd6d0cfcfa20b53bd35cb12ee5eac8796
+size 18721
diff --git a/marked/T/T-REC-T.330-198811-I_PDF-E/b3baf3a29b67c7425d2562ddbc52f0cc_img.jpg b/marked/T/T-REC-T.330-198811-I_PDF-E/b3baf3a29b67c7425d2562ddbc52f0cc_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..30c6fa1a80b0fbea280a27da50ef67c6a5aab4e8
--- /dev/null
+++ b/marked/T/T-REC-T.330-198811-I_PDF-E/b3baf3a29b67c7425d2562ddbc52f0cc_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:bf9e9388671530b48f35a9c1342823aac8f051453fa5381674b13ab14f4ab488
+size 45308
diff --git a/marked/T/T-REC-T.330-198811-I_PDF-E/raw.md b/marked/T/T-REC-T.330-198811-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..22e818abc5346f3285dd5eb50dcb6aed1f7e6073
--- /dev/null
+++ b/marked/T/T-REC-T.330-198811-I_PDF-E/raw.md
@@ -0,0 +1,3170 @@
+
+
+![ITU logo: a globe with the letters ITU and a lightning bolt symbol.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg)
+
+ITU logo: a globe with the letters ITU and a lightning bolt symbol.
+
+INTERNATIONAL TELECOMMUNICATION UNION
+
+**ITU-T**
+
+TELECOMMUNICATION  
+STANDARDIZATION SECTOR  
+OF ITU
+
+**T.330**
+
+**TERMINAL EQUIPMENT AND PROTOCOLS FOR  
+TELEMATIC SERVICES**
+
+---
+
+**TELEMATIC ACCESS TO INTERPERSONAL  
+MESSAGE SYSTEM**
+
+**ITU-T Recommendation T.330**
+
+(Extract from the *Blue Book*)
+
+---
+
+# NOTES
+
+1 ITU-T Recommendation T.330 was published in Fascicle VII.5 of the *Blue Book*. This file is an extract from the *Blue Book*. While the presentation and layout of the text might be slightly different from the *Blue Book* version, the contents of the file are identical to the *Blue Book* version and copyright conditions remain unchanged (see below).
+
+2 In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+# Recommendation T.330
+
+# TELEMATIC ACCESS TO INTERPERSONAL MESSAGE SYSTEM
+
+(Melbourne, 1988)
+
+The establishment in various countries of telematic services and computer-based store-and-forward message service in association with public data networks creates a need to produce standards to facilitate international message exchange between subscribers to such services.
+
+The CCITT,
+
+*considering*
+
+- (a) the need for interpersonal messaging and message transfer services;
+- (b) the need to transfer messages of different types having a large variety of formats;
+- (c) that within the X Series of Recommendations services and optional user facilities for public data networks are defined;
+- (d) that the F Series of Recommendations defines telematic services and that the T Series of Recommendations defines terminal equipment and control procedures for telematic services;
+- (e) that a set of Recommendation describes various aspects of message handling systems: X.400 Series;
+- (f) that Recommendation T.300 describes general principles of telematic interworking,
+
+*unanimously declares*
+
+that this Recommendation describes the access protocol to be used by telematic terminals when making additional use of the interpersonal messaging system.
+
+# CONTENTS
+
+|   |                                                                          |
+|---|--------------------------------------------------------------------------|
+| 0 | <i>Introduction</i>                                                      |
+| 1 | <i>Scope and field of application</i>                                    |
+| 2 | <i>References</i>                                                        |
+| 3 | <i>Definitions</i>                                                       |
+| 4 | <i>Abbreviations</i>                                                     |
+| 5 | <i>Conventions</i>                                                       |
+| 6 | <i>Overview of telematic access to IPMS</i>                              |
+|   | 6.1 Abstract model                                                       |
+|   | 6.2 Functional model                                                     |
+|   | 6.3 Access for registered and non-registered users                       |
+| 7 | <i>IPMS in the context of telematic interworking</i>                     |
+|   | 7.1 Objects and ports description                                        |
+|   | 7.2 Origination, reception and management ports, services and operations |
+|   | 7.3 Miscellanea port services and operations                             |
+| 8 | <i>Refinement of the TLMA object</i>                                     |
+|   | 8.1 Object and ports description                                         |
+|   | 8.2 The mhs-doc-xfer port operations                                     |
+
+|    |                                                               |
+|----|---------------------------------------------------------------|
+| 9  | <i>Abstract errors</i>                                        |
+| 10 | <i>Realization of abstract operations</i>                     |
+|    | 10.1 Description of TAPDU                                     |
+|    | 10.2 Operation of the TLMAU                                   |
+| 11 | <i>Formats and coding of TAPDU</i>                            |
+|    | 11.1 Principles                                               |
+|    | 11.2 Structure and format of TAPDU                            |
+|    | 11.3 Coding of TAPDU                                          |
+|    | 11.4 Format of TAPDU                                          |
+|    | 11.5 Reference between TAPDU components and its coding format |
+| 12 | <i>Error recovery</i>                                         |
+| 13 | <i>Control procedures</i>                                     |
+|    | 13.1 Session control procedures                               |
+|    | 13.2 Document control procedures                              |
+|    | 13.3 Log-on procedures                                        |
+
+*Annex A* - Formal definition of TLMA abstract service
+
+*Annex B* - Format of TAPDU components
+
+*Annex C* - Element ID list
+
+*Annex D* - Element of service for TTX/IPM service intercommunications
+
+# **0 Introduction**
+
+Recommendation T.330 is one of a series of Recommendations dealing with telematic interworking. Telematic interworking is the generic name for a set of applications provided to telematic users. Each of those applications is called a telematic interworking application (TIA).
+
+Access to and participating in interpersonal messaging system (IPMS) are one of the telematic interworking applications. This Recommendation aims at specifying this application.
+
+# **1 Scope and field of application**
+
+This Recommendation defines the abstract service provided by the telematic agent (TLMA) which is defined as an object of IPMS. It specifies not only abstract operations provided by TLMAU but also access protocol (P5) to be used between a TLMAU and a telematic (TLM) terminal, when participating in and accessing the IPMS. The P5 access protocol is a generalized access protocol; it is applicable to other applications such as network based storage for the teletex service. The TLM terminals being considered in this Recommendation are teletex, G4 facsimile and mixed mode terminals. The use of other types of TLM terminals are for further study.
+
+Other Recommendations in the series contain description on telematic interworking model, the functions of the telematic access unit (TLMAU), and telematic access protocol to specific services, such as telematic, telex, directory, etc. Recommendation T.300 outlines the principles of telematic interworking procedures.
+
+Section 6 of this Recommendation defines overview of telematic access to IPMS provided by TLMA object. Section 7 defines the IPMS in the context of telematic interworking. Section 8 refines the TLMA object and defines abstract operations at a specific port of TLMAU and TLM terminal. Section 9 defines abstract errors used in telematic interworking. Section 10 specifies an access protocol (P5). Section 11 specifies formatting and coding rule of protocol. Section 12 specifies an error recovery mechanism. Section 13 specifies control procedures.
+
+The purpose of a TLMAU is to aid the user of a TLM terminal in gaining access to the features of the IPMS. The TLMAU, which is associated with a message transfer system (MTS), provides the TLM terminal with access to the IPMS.
+
+The TLMAU may also provide a *document storage (DS)* facility to accept delivery of messages from the MTS for TLM users. Document storage is basically defined as a TLM terminal storage extension facility located in the TLMAU allowing reservation of a specific amount of storage for an individual user. Users of TLM terminals may also be registered as users of DS.
+
+# 2 References
+
+This Recommendation cites the documents listed below.
+
+## 2.1 *Telematic interworking*
+
+- Rec. T.300: General principles of telematic interworking.
+
+## 2.2 *Message handling systems*
+
+- Rec. X.400: Message handling systems: System and service overview
+- Rec. X.402: Message handling systems: Overall architecture
+- Rec. X.407: Message handling systems: Abstract service definition conventions
+- Rec. X.411: Message handling systems: Message transfer system: Abstract service definition and procedures
+- Rec. X.413: Message handling systems: Message store: Abstract service definition
+- Rec. X.419: Message handling systems: Protocol specifications
+- Rec. X.420: Message handling systems: Interpersonal messaging system
+
+## 2.3 *Control procedures*
+
+- Rec. T.62: Control procedures for Teletex and Group 4 facsimile services
+
+## 2.4 *ASN.1 coding*
+
+- Rec. X.208: Specification of abstract syntax notation one (ASN.1)
+- Rec. X.219: Remote operation
+
+## 2.5 *Address*
+
+- Rec. X.121: International numbering plan for public data networks
+
+## 2.6 *Character repertoires*
+
+- Rec. T.61: Character repertoire and coded character sets for the international Teletex service
+
+## 2.7 *Intercommunication*
+
+- Rec. F.422: Intercommunication between Teletex service and IPM service.
+- Rec. F.203: Network based storage for the Teletex service.
+
+# 3 Definitions
+
+This Recommendation uses the terms many of those used in Recommendations X.402, X.411 and X.420.
+
+In addition to the above terms, this Recommendation uses as terms the names of abstract objects, ports, operations and errors; the names of ASN.1 data types; the names of the information item types and values this Recommendation specifies.
+
+# 4 Abbreviations
+
+|         |                                          |
+|---------|------------------------------------------|
+| ASN.1   | Abstract syntax notation one             |
+| AU      | Access unit                              |
+| C       | Conditional/consumer                     |
+| CDC     | Command document continue                |
+| CF      | Conversion facility                      |
+| CSCC    | Command session change control           |
+| CSS     | Command session start                    |
+| DN      | Delivery status notification             |
+| DS      | Document storage                         |
+| G3      | Group 3 facsimile                        |
+| G4      | Group 4 facsimile                        |
+| ID      | Identity                                 |
+| IP      | Interpersonal                            |
+| IPM     | Interpersonal messaging                  |
+| IPMAS   | Interpersonal messaging abstract service |
+| IPME    | Interpersonal messaging environment      |
+| IPMS    | Interpersonal messaging system           |
+| IPM-UA  | Interpersonal messaging user agent       |
+| IPN     | Interpersonal notification               |
+| M       | Mandatory                                |
+| S       | Message store                            |
+| T       | Message transfer                         |
+| TA      | Message transfer agent                   |
+| TAS     | Message transfer abstract service        |
+| MTS     | Message transfer system                  |
+| NDN     | Non-delivery status notification         |
+| NL      | New line                                 |
+| NRN     | Non-receipt notification                 |
+| O/R     | Originator/receipt                       |
+| PDAU    | Physical delivery access unit            |
+| PTTXAU  | Public Teletex access unit               |
+| P5      | Telematic access protocol                |
+| RN      | Receipt status notification              |
+| S       | Supplier                                 |
+| TAPDU   | Telematic access protocol data unit      |
+| TIA     | Telematic interworking application       |
+| TID     | Terminal identification                  |
+| TLM     | Telematic                                |
+| TLMA    | Telematic agent                          |
+| TLMAU   | Telematic access unit                    |
+| TLM-TER | Telematic terminal                       |
+| TLXAU   | Telex access unit                        |
+| TTX     | Teletex                                  |
+| UA      | User agent                               |
+
+# 5 Conventions
+
+This Recommendation uses the descriptive conventions identified below.
+
+## 5.1 *ASN.1*
+
+This Recommendation uses the following ASN.1-based descriptive conventions for the indicated purposes:
+
+- a) to specify the functional objects, the OBJECT and REFINE macros and associated conventions of Recommendation X.407;
+- b) to specify the information objects (and other data types and values of all kinds), ASN.1 itself;
+- c) to specify the abstract service, the PORT and ABSTRACT-BIND, -UNBIND, -OPERATION, and -ERROR macros and associated conventions of Recommendation X.407.
+
+## 5.2 *Grade*
+
+Whenever this Recommendation describes a class of data structure (e.g. Headings) having components (e.g. fields), each component is categorized as one of the following grades:
+
+- a) Mandatory (M): A mandatory component shall be present in every member of the class.
+- b) Conditional (C): A conditional component shall be present in a member of the class as dictated by this Recommendation.
+
+# 6 Overview of telematic access to IPMS
+
+## 6.1 *Abstract model*
+
+This Recommendation makes use of the message handling abstract service definitions conventions defined in Recommendation X.407. These conventions provide a descriptive tool for the specification of information processing tasks in abstract terms. This ensures that a tasks functional requirements are stated independently of its realization.
+
+## 6.2 *Functional model*
+
+This section provides a functional model of telematic access to IPMS. The purpose of this model is to provide a general description of the functional entities, which are then explicitly defined using the definitions and conventions found in Recommendation X.407, and further refined as necessary, in following sections (see Figure 1/T.330).
+
+![Functional model diagram for Telematic access to IPMS. The diagram shows a sequence of functional entities: LM-TER, TLMA, OS, MTS, MS, and UA. LM-TER is connected to TLMA, which is connected to OS. OS is connected to MTS. MTS is connected to MS, which is connected to UA. There is also a direct connection from MTS to UA. The diagram is labeled 'FIGURE 1/T.330' at the bottom right.](34f788b0e5bc8af774fa5561c22e6d01_img.jpg)
+
+```
+graph LR
+    LM-TER --- TLMA
+    TLMA --- OS
+    OS --- MTS
+    MTS --- MS
+    MS --- UA
+    MTS --- UA
+```
+
+Functional model diagram for Telematic access to IPMS. The diagram shows a sequence of functional entities: LM-TER, TLMA, OS, MTS, MS, and UA. LM-TER is connected to TLMA, which is connected to OS. OS is connected to MTS. MTS is connected to MS, which is connected to UA. There is also a direct connection from MTS to UA. The diagram is labeled 'FIGURE 1/T.330' at the bottom right.
+
+FIGURE 1/T.330
+
+**Telematic access to IPMS: Functional model**
+
+The functional model comprises the following functional entities:
+
+- Telematic agent (TLMA): Logical entity only which comprises the TLMAU and the telematic terminal. The TLMA is useful as an object in the refinement of the IPMS.
+- Telematic access unit (TLMAU): Functional entity which provides all of the interworking functions between telematic codes and protocols and IPMS codes and protocols. The TLMAU also supports the DS functionality.
+- Telematic terminal (TLM-TER): The telematic terminal.
+- Access unit (AU): Functional entity which provides access to message handling applications for indirect users of the MTS.
+- Document storage (DS): Extension of the telematic terminal storage capabilities. The TLMAU may optionally, on a subscription basis, deliver messages to a DS. The terminal may then retrieve the message for the document storage when convenient.
+- Message store (MS): Functional entity which provides single direct user of message handling with capabilities for message storage. Although the MS and DS provide a similar functionality, there is no relationship between the two.
+- Message transfer system (MTS): Functional entity which conveys information objects between individual users and members of distribution lists.
+- User agent (UA): Functional entity by means of which a direct user engages in message handling.
+
+## 6.3 *Access for registered and non-registered users*
+
+Two types of access to the IPM service are defined within this Recommendation. Registered users of the IPM service who wish to use telematic terminal equipment to access the IPM service are provided with complete IPM service functionality with any full implementation of this Recommendation.
+
+Telematic terminal equipment users who are not registered IPM service subscribers but who wish to direct a message to an IPM service user are provided with a subset of the functionality defined within this Recommendation, in accordance with Recommendation F.422 and Annex D of this Recommendation. This functionality is referred to as a public teletex access unit (PTTXAU).
+
+# 7 **IPMS in the context of telematic interworking**
+
+## 7.1 *Objects and ports description*
+
+The refinement of the IPMS is found in Recommendation X.420 (interpersonal messaging system). The IPMS refinement describes secondary objects, one of which is the telematic agent (TLMA) which is paired to the MTS by the import and export ports.
+
+The TLMA is visible to the telematic user through four ports, namely: origination, reception, management and miscellanea. The origination, reception and management port services and operations are described fully in Recommendation X.420. The miscellanea port services and operations are described in this Recommendation. The import and export port services and operations are described in Recommendation X.411.
+
+```
+tlma          OBJECT
+PORTS { origination [S],
+         reception  [S],
+         management [S],
+         miscellanea [S],
+         import     [C],
+         export     [C]}
+:: = id-ot-tlma
+```
+
+The IPMS comprises any number of TLMA.
+
+TLM users are communicants in telematic interworking. A TLM user originates or receives information objects whose types are specified in Recommendation X.420 and this Recommendation.
+
+```
+
+tlm-user      OBJECT
+  PORTS { origination [C],
+           reception  [C],
+           management [C],
+           miscellanea [C] }
+  ::= id-ot-tlm-user
+
+```
+
+A telematic user is associated with the TLMA by means of the origination, reception, management and miscellanea ports. A telematic user is a supplier [S] of no ports and a consumer [C] of all TLMA ports. The TLMA is a supplier of all TLMA ports and consumer of no ports.
+
+The general access to IPMS is illustrated in Figure 2/T.330.
+
+![Diagram illustrating the general access to IPMS. The diagram shows a central 'IPMS' block containing 'TLMA', 'MTS', 'IPM-UA', and 'AU'. 'TLMA' is connected to 'IPM user' (left) via 'Origination', 'Reception', 'Management', and 'Miscellanea' ports. 'IPM-UA' is connected to 'IPM user' (right) via 'Origination', 'Reception', and 'Management' ports. 'MTS' is connected to 'TLMA' via 'Import' and 'Export' ports. 'MTS' is connected to 'IPM-UA' via 'Substitution', 'Delivery', and 'Administration' ports. 'AU' is connected to 'MTS' and 'User' (bottom).](b3baf3a29b67c7425d2562ddbc52f0cc_img.jpg)
+
+The diagram illustrates the general access to IPMS. It shows a central 'IPMS' block containing 'TLMA', 'MTS', 'IPM-UA', and 'AU'. 'TLMA' is connected to 'IPM user' (left) via 'Origination', 'Reception', 'Management', and 'Miscellanea' ports. 'IPM-UA' is connected to 'IPM user' (right) via 'Origination', 'Reception', and 'Management' ports. 'MTS' is connected to 'TLMA' via 'Import' and 'Export' ports. 'MTS' is connected to 'IPM-UA' via 'Substitution', 'Delivery', and 'Administration' ports. 'AU' is connected to 'MTS' and 'User' (bottom).
+
+Diagram illustrating the general access to IPMS. The diagram shows a central 'IPMS' block containing 'TLMA', 'MTS', 'IPM-UA', and 'AU'. 'TLMA' is connected to 'IPM user' (left) via 'Origination', 'Reception', 'Management', and 'Miscellanea' ports. 'IPM-UA' is connected to 'IPM user' (right) via 'Origination', 'Reception', and 'Management' ports. 'MTS' is connected to 'TLMA' via 'Import' and 'Export' ports. 'MTS' is connected to 'IPM-UA' via 'Substitution', 'Delivery', and 'Administration' ports. 'AU' is connected to 'MTS' and 'User' (bottom).
+
+FIGURE 2/T.330
+
+### General access to IPMS
+
+An interpersonal messaging user agent (IPM-UA) is a secondary object that provides the interpersonal messaging abstract service (IPMAS) to a single IPM user. An IPM-UA is a specialized instance of the more general object, UA. An IPM-UA performs its function with help from the MTS.
+
+A telematic agent (TLMA) is an object that provides the abstract service which comprises IPMAS and telematic specific abstract service, to a single TLM user. A TLMA is an instance of the more general object UA. A TLMA performs its function with help from the MTS.
+
+A message transfer system (MTS), upon which all other IPMS components relay, is the provider of the message transfer abstract service (MTAS). It performs its function without assistance.
+
+An interpersonal messaging system (IPMS) is the object by means of which all users communicate in interpersonal messaging.
+
+The access unit (AU) could be a physical delivery access unit (PDAU), or telex access unit (TLXAU). The descriptions of these objects found in relevant Recommendations,
+
+## 7.2 *Origination, reception and management ports, services and operations*
+
+The abstract operations available at these ports, as described in X.420, are:
+
+origination PORT
+
+```
+CONSUMER INVOKERS { OriginateProbe,
+                     OriginateIPM,
+                     OriginateRN,
+                     CancelIPM }
+:: = id-pt-origination
+```
+
+reception PORT
+
+```
+CONSUMER INVOKERS { ReceiveReport,
+                     ReceiveIPM,
+                     ReceiveRN,
+                     ReceiveNRN }
+:: = id-pt-reception
+```
+
+management PORT
+
+```
+CONSUMER INVOKERS { ChangeAutoDiscard,
+                     ChangeAutoAcknowledgment,
+                     ChangeAutoForwarding }
+:: = id-pt-management
+```
+
+The abstract operations are fully described in Recommendation X.420.
+
+## 7.3 *Miscellanea port services and operations*
+
+Besides IPM abstract services, the following abstract services are available at the miscellanea port. They are provided by the TLMA object as the miscellanea abstract services.
+
+miscellanea PORT
+
+```
+SUPPLIER PERFORMS { ChangeSubscriptionProfile,
+                     DSList,
+                     DSDelete,
+                     DSFetch,
+                     MessageStatus }
+:: = id-pt-miscellanea
+```
+
+### 7.3.1 *ChangeSubscriptionProfile*
+
+The ChangeSubscriptionProfile abstract operation enables a user to change the registered subscription profile which specifies relationship with the TLMAU, such as DS mode, error recovery mode and message delete mode.
+
+ChangeSubscriptionProfile :: = ABSTRACT-OPERATION
+
+```
+ARGUMENT SET { ds-mode           [0] DSMode OPTIONAL,
+                error-recovery-mode [1] ErrorRecoveryMode OPTIONAL,
+                message-delete-mode [2] MessageDeleteMode OPTIONAL }
+
+RESULT {}
+
+ERRORS { name-error,
+         ds-error,
+         subscription-profile-error }
+```
+
+#### 7.3.1.1 *Arguments of ChangeSubscriptionProfile*
+
+This abstract operation has the following arguments:
+
+- a) DS-mode (C): The document storage mode to be applied. One of the following values:
+  - 1) retrieval: In the mode, the TLMAU holds the messages in the DS until they are explicitly deleted by the user;
+  - 2) auto output: In this mode, the TLMAU tries to output messages under user subscribed conditions after they are delivered to the DS.
+
+- b) Error-recovery-mode (C): This mode, whose recovery mechanism is defined in § 12 of this Recommendation has to be applied. (Recovery-1, 2 or 3.)
+- c) Message-delete-mode (C): Mode to be applied. One of the following values:
+  - 1) auto delete: In this mode, the messages in the DS are deleted as soon as they are output to the user by the performance of the DS fetch abstract operation with no delete-after-output argument (in case of retrieval mode), or by the automatically output (in case of auto-output mode);
+  - 2) manual delete: In this mode, the messages in the DS are held until the DS delete abstract operation or DS fetch abstract operation whose delete-after-output argument is "delete after output", will be carried out.
+
+#### 7.3.1.2 *Results of ChangeSubscriptionProfile*
+
+This abstract operation has no results.
+
+#### 7.3.1.3 *Error of ChangeSubscriptionProfile*
+
+This abstract operation has name-error, ds~error and subscription-profile error. These abstract errors are commonly described in § 9.
+
+### 7.3.2 *DSList*
+
+The DSList abstract operation enables a user to get a list of messages (IPMs, IPNs or reports) currently held in the document storage (DS).
+
+DSList ::= ABSTRACT-OPERATION
+
+ARGUMENT {}  
+ RESULT SET {[0] SET OF ListReport OPTIONAL }  
+ ERRORS { subscription-error,  
+           name-error,  
+           ds-error }
+
+ListReport ::= SET { retrieval-id                 [0] RetrievalIdentifier,  
+                     message-type            [1] MessageType,  
+                     priority                 [2] Priority OPTIONAL,  
+                     message-length         [3] MessageLength OPTIONAL,  
+                     originator-name        [4] OrName OPTIONAL }
+
+#### 7.3.2.1 *Argument of DSList*
+
+This abstract operation has no argument.
+
+#### 7.3.2.2 *Results of DSList*
+
+This abstract-operation has the following results:
+
+- a) List-report: The characteristics of message held in DS.
+  - 1) Retrieval-id (M): The retrieval-Id assigned to the message in DS.
+  - 2) Message-type (M): The type of message (IPM, RN, NRN or report).
+  - 3) Priority (C): The priority of the message (normal, non-urgent or urgent).
+  - 4) Message-length (C): The length of the message in octet.
+  - 5) Originator-name (C): The originator name of the message.
+
+#### 7.3.2.3 *Errors of DSList*
+
+This abstract operation has subscription-error, name-error and ds-error. These abstract errors are described in § 9.
+
+### 7.3.3 *DSDelete*
+
+The DSDelete abstract operation enable a user to delete one or more specified messages in DS.
+
+DSDelete ::= ABSTRACT-OPERATION
+
+ARGUMENT SET { selector [0] SET OF RetrievalIdentifier }  
+RESULT {}  
+ERRORS { subscription-error,  
+          name-error,  
+          ds-error }
+
+#### 7.3.3.1 *Arguments of DSDelete*
+
+This abstract operation has the following arguments:
+
+- a) Selector (M): The selector is the list of the retrieval-id of messages that have to be deleted.
+
+#### 7.3.3.2 *Results of DSDelete*
+
+This abstract operation has no results.
+
+#### 7.3.3.3 *Errors of DSDelete*
+
+This abstract operation has subscription-error, name-error and ds-error. These abstract errors are described in § 9.
+
+### 7.3.4 *DSFetch*
+
+The DSFetch abstract operation enables a user to get one or more specified messages (IPMs, IPNs or reports) from DS.
+
+DSFetch ::= ABSTRACT-OPERATION
+
+ARGUMENT SET OF { retrieval-id [0] RetrievalIdentifier,  
+                                  delete-after-output [1] DeleteAfterOutput OPTIONAL }  
+RESULT SET { retrieval-id [0] RetrievalIdentifier,  
+              message-report [1] MessageReport  
+ERRORS { subscription-error,  
+          name-error,  
+          ds-error }
+
+#### 7.3.4.1 *Arguments of DSFetch*
+
+This abstract operation has the following arguments:
+
+- a) Retrieval-id (M): The retrieval-id assigned to the message in DS.
+- b) Delete-after-output (C): This value indicates whether or not the message is deleted after retrieval. If this argument does not exist, registered mode, message-delete-mode, is applied.
+
+#### 7.3.4.2 *Results of DSFetch*
+
+This abstract-operation has the following results:
+
+- a) Retrieval-id (M): The retrieval-id assigned to the message that was reported.
+- b) Message report (M): Envelope and content of reported message IPM, RN, NRN or report), assigned by retrieval-id.
+
+#### 7.3.4.3 *Errors of DSFetch*
+
+This abstract operation has subscription-error, name-error and ds-error. These abstract errors are described in § 9.
+
+### 7.3.5 *MessageStatus*
+
+The MessageStatus abstract operation enables a user to get an information on the actual status of the previously submitted IPM.
+
+MessageStatus ::= ABSTRACT-OPERATION
+
+ARGUMENT SET { [0] QueryIdentifier OPTIONAL }  
+RESULT SET { report-time [0] DateandTime,  
+reported-message-id [1] MessageIdentifier,  
+[2] SEQUENCE OF StatusInfo }
+
+ERRORS { subscription-error,  
+name-error,  
+message-status-error }
+
+QueryIdentifier ::= CHOICE { submission-id [0] MessageIdentifier,  
+correlation-info [1] CallIdentification }
+
+StatusInfo ::= SET { status [0] Status,  
+per-recipient-info [1] PerRecipientReportDeliveryFields OPTIONAL }
+
+#### 7.3.5.1 Arguments of MessageStatus
+
+This abstract operation has the following arguments:
+
+- a) Query-identifier (C): This identifier enables the TLMAU to identify the message whose status is being reported. Two types of query-identifiers are available:
+  - 1) submission-Id (C): The message-Id of the originated message whose status wants to query, returned as a result of the OriginateIPM abstract operation;
+  - 2) correlation-info (C): The call-identification of the originated message whose status wants to query.
+
+#### 7.3.5.2 Results of MessageStatus
+
+This abstract operation has the following results:
+
+- a) Report-time (M): The date and time the report is made.
+- b) Message-id (M): The message-identifier of the originated message whose status is being reported, returned as a result of the OriginateIPM abstract operation.
+- c) Status-info (M): The status information of previously submitted messages.
+  - 1) Status: The status of the previously submitted IPM (in-process, delivered or non-delivered).
+  - 2) Per-recipient-info: Information about subject-message's status with respect to particular intended-recipients. A sequence of MTS per-recipient-field items, one for each recipient. This component does not exist until status component become delivered or non-delivered.
+
+#### 7.3.5.3 Errors of MessageStatus
+
+This abstract operation has subscription-error, name-error and message-status-error. These abstract errors are described in § 9.
+
+# 8 Refinement of the TLMA object
+
+## 8.1 Object and ports description
+
+In this Recommendation, the TLMA is refined further into secondary objects namely: the TLMA and the TLM-TER object.
+
+tlma-refinement REFINE tlma AS  
+tlmau mhs-doc-xfer [S] PAIRED with { tlm-ter }  
+tlm-ter origination [S] VISIBLE  
+reception [S] VISIBLE  
+management [S] VISIBLE  
+miscellanea [S] VISIBLE  
+::= id-ref-secondary
+
+The mhs-doc-xfer is a port that enables the interaction of the TLM-TER and the TLMAU.
+
+Figure 3/T.330 illustrates refinement of TLMA.
+
+![Figure 3/T.330: Refinement of TLMA. The diagram shows a sequence of interactions between a TLM user and a TLM terminal. The TLM user has ports for Origination, Reception, Management, and Miscellaneous. The TLM terminal has ports for mhs-doc-xfer, Import, and Export. A dashed oval labeled 'TLMA' encloses the TLM user and the TLM terminal. Arrows indicate the flow of messages between the TLM user and the TLM terminal, and between the TLM terminal and the TLM user. The TLM user sends Origination and Reception messages to the TLM terminal. The TLM terminal sends Management and Miscellaneous messages to the TLM user. The TLM terminal also sends mhs-doc-xfer, Import, and Export messages to the TLM user. The TLM user sends mhs-doc-xfer, Import, and Export messages to the TLM terminal.](4801720824e4b5e2361a5564f91cfb70_img.jpg)
+
+Figure 3/T.330: Refinement of TLMA. The diagram shows a sequence of interactions between a TLM user and a TLM terminal. The TLM user has ports for Origination, Reception, Management, and Miscellaneous. The TLM terminal has ports for mhs-doc-xfer, Import, and Export. A dashed oval labeled 'TLMA' encloses the TLM user and the TLM terminal. Arrows indicate the flow of messages between the TLM user and the TLM terminal, and between the TLM terminal and the TLM user. The TLM user sends Origination and Reception messages to the TLM terminal. The TLM terminal sends Management and Miscellaneous messages to the TLM user. The TLM terminal also sends mhs-doc-xfer, Import, and Export messages to the TLM user. The TLM user sends mhs-doc-xfer, Import, and Export messages to the TLM terminal.
+
+FIGURE 3/T.330
+
+### Refinement of TLMA
+
+A telematic access unit (TLMAU) is a secondary object to the TLMA object. It provides a TLM-TER with access to any TLM user within the interpersonal messaging environment. (IPME: see Recommendation X.420.)
+
+The TLM-TER is a secondary object to the TLMA object.
+
+TLM-TERs are communicants in telematic interworking. A TLM-TER sends or receives documents, embodying information objects whose types are specified In Recommendation X.420 and this Recommendation.
+
+TLM-TER shall be addressable by at least a Network address (see Recommendation X.402), and may also be addressed by one or more other forms of ORName.
+
+```
+
+tlm-ter          OBJECT
+  PORTS { origination    [S],
+           reception     [S],
+           management    [S],
+           miscellanea   [S],
+           mhs-doc-xfer  [C] }
+  ::= id-ot-tlm-ter
+
+```
+
+```
+
+tlmau           OBJECT
+  PORTS { mhs-doc-xfer   [S],
+           import        [C],
+           export        [C] }
+  ::= id-ot-tlm-user
+
+```
+
+The TLMA comprises one TLM terminal and one TLMAU.
+
+## 8.2 The mhs-doc-xfer port operations
+
+The following abstract operations are available at the mhs-doc-xfer port. The correspondence between mhs-doc-xfer port abstract operations and IPMS ports plus telematic specific port abstract operations are described in Table 1/T.330.
+
+In this Recommendation TLM terminals implicitly bind a certain port at the time that the session is established and implicitly unbind a certain port at the time the session is released because Recommendation T.62 session procedure does not have association control.
+
+```
+
+mhs-doc-xfer PORT
+  SUPPLIER PERFORMS { MessageSend,
+                     MessageProbe,
+                     ExplicitReceive,
+                     MessageCancel,
+                     Register,
+                     DSList,
+                     DSDelete,
+                     DSFetch,
+                     MessageStatus }
+  CONSUMER PERFORMS { MessageDeliver,
+                     ReceiptStatusNotice,
+                     DeliveryStatusNotice }
+  ::= id-pt-mhs-doc-xfer
+
+```
+
+TABLE 1/T.330
+
+### **Operations of mhs-doc-xfer port**
+
+| IPMS ports and telematic specific port |                                                                                                 |          |           | mhs-doc-xfer port                                                                                    |         |           |
+|----------------------------------------|-------------------------------------------------------------------------------------------------|----------|-----------|------------------------------------------------------------------------------------------------------|---------|-----------|
+| Port                                   | Abstract operation                                                                              | Invoker  | Performer | Abstract operation                                                                                   | Invoker | Performer |
+| Origination                            | (1) OriginateIPM<br>(2) OriginateProbe<br>(3) OriginateRN<br>(4) CancelIPM                      | TLM-User | TLM-TER   | (1) MessageSend<br>(2) MessageProbe<br>(3) ExplicitReceive<br>(4) MessageCancel                      | TLM-TER | TLMAU     |
+| Reception                              | (1) ReceiveIPM<br>(2) ReceiveRN<br>(3) ReceiveNRN<br>(4) ReceiveReport                          | TLM-TER  | User      | (1) MessageDeliver<br>(2) ReceiptStatusNotice<br>(3) ReceiptStatusNotice<br>(4) DeliveryStatusNotice | TLMAU   | TLM-TER   |
+| Management                             | (1) ChangeAutoDiscard<br>(2) ChangeAutoAcknowledge<br>(3) ChangeAutoForwarding                  | TLM-User | TLM-TER   | (1) Register<br>(2) Register<br>(3) Register                                                         | TLM-TER | TLMAU     |
+| Miscellanea                            | (1) ChangeSubscriptionProfile<br>(2) DSList<br>(3) DSDelete<br>(4) DSFetch<br>(5) MessageStatus | TLM-User | TLM-TER   | (1) Register<br>(2) DSList<br>(3) DSDelete<br>(4) DSFetch<br>(5) MessageStatus                       | TLM-TER | TLMAU     |
+
+### **8.2.1 MessageSend**
+
+MessageSend is the abstract operation at mhs-doc-xfer port that is invoked by TLM terminal to perform OriginateIPM abstract operation at TLM terminal. This abstract operation is used to submit the IPM from TLM terminal to TLMAU.
+
+The description of OriginateIPM abstract operation is in Recommendation X.420.
+
+### **8.2.2 MessageProbe**
+
+MessageProbe is the abstract operation at mhs-doc-xfer port that is invoked by TLM terminal to perform OriginateProbe abstract operation at TLM terminal. This abstract operation is used to determine whether or not this IPM could be delivered to one or more recipients.
+
+The description of OriginateProbe abstract operation is in Recommendation X.420.
+
+### **8.2.3 ExplicitReceive**
+
+ExplicitReceive is the abstract operation at mhs-doc-xfer port that is invoked by TLM terminal perform OriginateRN abstract operation at TLM terminal. This abstract operation is used to be originated by the actual-recipient of the subject IPM of whom RN is requested by means of notification-requests component of the subject IPM's recipient-specification.
+
+The description of OriginateRN abstract operation is in Recommendation X.420.
+
+### **8.2.4 MessageCancel**
+
+MessageCancel is the abstract operation at mhs-doc-xfer port that is invoked by TLM terminal to perform CancelIPM abstract operation at TLM terminal. This abstract operation is used to cancel if it can the delivery of previously originated message whose content is an IPM and for which deferred delivery was requested. There is no result in MessageCancel abstract operation.
+
+The description of CancelIPM abstract operation is in Recommendation X.420.
+
+### 8.2.5 *MessageDeliver*
+
+MessageDeliver is the abstract operation at mhs-doc-xfer port that is invoked by TLMAU to perform ReceiveIPM at TLM terminal. This abstract operation is used to deliver the IPM from TLMAU to TLM terminal. There is no result or error in MessageDeliver abstract operation.
+
+The description of ReceiveIPM abstract operation is in Recommendation X.420.
+
+### 8.2.6 *ReceiptStatusNotice*
+
+ReceiptStatusNotice is the abstract operation at mhs-doc-xfer port that is invoked by TLMAU to perform ReceiveRN or ReceiveNRN abstract operation at TLM terminal. This abstract operation is used to report the IPN that was invoked by an IPM originated by means of the MessageSend abstract operation. There is no result or error in ReceiptStatusNotice abstract operation.
+
+The description of ReceiveRN or ReceiveNRN abstract operation is in Recommendation X.420.
+
+### 8.2.7 *DeliveryStatusNotice*
+
+DeliveryStatusNotice is the abstract operation at mhs-doc-xfer port that invoked by TLMAU to perform ReceiveReport abstract operation at TLM terminal. This abstract operation is used to deliver the DN that was invoked by a IPM originated by means of the MessageSend abstract operation. There is no result or error in DeliveryStatusNotice abstract operation.
+
+The description of ReceiveReport abstract operation is in Recommendation X.420.
+
+### 8.2.8 *Register*
+
+Register is the abstract operation at mhs-doc-xfer port that is invoked by TLM terminal to perform all management port's abstract operations and ChangeSubscriptionProfile mode abstract operation. This abstract operation is used to register or change the parameters that will be kept on the parameter list of TLMAU.
+
+The description of all management port's abstract operations is in Recommendation X.420 and ChangeSubscriptionProfile abstract operation found in § 7.3.1 of this Recommendation.
+
+### 8.2.9 *DSList*
+
+DSList is the abstract operation at mhs-doc-xfer port that is invoked by TLM terminal to perform DSList abstract operation at TLM terminal. This abstract operation is used to request the status list of a previously delivered IPMs, RNs, NRNs or reports.
+
+The description of DSList abstract operation is in § 7.3.2 of this Recommendation.
+
+### 8.2.10 *DSDelete*
+
+DSDelete is the abstract operation at mhs-doc-xfer port that is invoked by TLM terminal to perform DSDelete abstract operation at TLM terminal, and is used to delete one or more messages from the DS. There is no result in DSDelete abstract operation.
+
+The description of DSDelete abstract operation is in § 7.3.3 of this Recommendation.
+
+### 8.2.11 *DSFetch*
+
+DSFetch is the abstract operation at mhs-doc-xfer port that is invoked by TLM terminal to perform DSFetch abstract operation, and is used to fetch one specified message (IPM, RN, NRN or report), from the DS.
+
+The description of DSFetch abstract operation is in § 7.3.4 of this Recommendation.
+
+### 8.2.12 *MessageStatus*
+
+MessageStatus is the abstract operation at mhs-doc-xfer port that invoked by TLM terminal to perform MessageStatus abstract operation. This abstract operation is used to know the status of previously submitted IPM by means of MessageSend abstract operation.
+
+The description of MessageStatus abstract operation is in § 7.3.5 of this Recommendation.
+
+# 9 Abstract errors
+
+The abstract errors that may be reported in response to the invocation of abstract operations at the IPM's origination, reception and management ports are subscription error, name error and cancellation error, and in miscellaneous port, subscription profile error, DS error and message status error. They are defined and described in the present section.
+
+## a) Subscription error
+
+The subscription error abstract error reports that the user has not subscribed to one or more of the element of service implicit in his invocation of the abstract operation when performance is aborted.
+
+The description of abstract error macro and abstract errors of subscription error is in Recommendation X.420.
+
+## b) Name error
+
+The name error abstract error reports that one or more of the O/R names supplied as argument of the abstract operation whose performance is aborted, or as components of its arguments, are invalid.
+
+The description of abstract error macro and abstract errors of name error is in Recommendation X.420.
+
+## c) Cancellation error
+
+The cancellation error abstract error reports that the user's request to cancel the delivery of a message cannot be performed.
+
+The description of abstract error macro and abstract errors of cancellation error is in Recommendation X.420.
+
+## d) Subscription profile error
+
+The user's request to change his subscription-profile cannot be performed, because one or more arguments proposed are unacceptable.
+
+subscription-profile-error ABSTRACT-ERROR
+
+```
+PARAMETER SET { problem [0] SubscriptionProfileProblem }  
+::= 0
+```
+
+This abstract error has the following parameters:
+
+1) Problem (M): The specific subscription profile related problem encountered.
+
+SubscriptionProfileProblem ::= CHOICE { [0] not-changed }
+
+This parameter may assume any one of the following values:
+
+- not-changed: One or more subscription-profile arguments proposed are unacceptable, this abstract-operation is not performed.
+
+## e) DS error
+
+The argument related DS cannot be performed because one or more arguments are improperly specified.
+
+ds-error ABSTRACT-ERROR
+
+```
+PARAMETER SET { problem [0] DSProblem }  
+::= 1
+```
+
+This abstract error has the following parameter:
+
+1) Problem (M): The specific DS related problem encountered.
+
+```
+DSProblem ::= CHOICE { [0] no-message-in-ds,  
+                        [1] ds-not-supported,  
+                        [2] ds-not-subscribed,  
+                        [3] retrieval-identifier-invalid,  
+                        [4] parameter-invalid }
+```
+
+This parameter may assume any one of the following values:
+
+- no-message-in-ds: User requests to perform DS related abstract operation when there is no message in DS.
+
+- ds-not-supported: User requests to perform DS related abstract-operation when TLMAU does not provide DS.
+- ds-not-subscribed: User requests to perform DS related abstract-operation when he does not subscribe to DS.
+- retrieval-identifier-invalid: The retrieval-id proposed is invalid.
+- parameter-invalid: One or more arguments proposed are invalid.
+
+## f) **MessageStatusError**
+
+No such message can be assigned by the query-identifier for message status abstract operation.
+
+**message-status-error**    **ABSTRACT-ERROR**
+
+**PARAMETER SET { problem [0] MessageStatusProblem }**  
+    **::= 2**
+
+This abstract-error has the following parameter:
+
+- 1) **Problem (M):** The specific message status related problem encountered.
+
+**MessageStatusProblem ::= CHOICE { [0] query-identifier-invalid }**
+
+This parameter may assume any one of the following values:
+
+- query-identifier-invalid: The query-identifier proposal is unacceptable.
+
+# **10 Realization of abstract operations**
+
+How a TLMAU realizes the mhs-doc-xfer port by means of which it interacts with a TLM terminal is specified in this section. But how a TLMA realizes the ports by means of which it interacts with a TLM user and MTS is outside the scope of this Recommendation.
+
+Telematic access protocol for accessing to IPMS, called P5 protocol, is provided to realize the interaction, which means abstract operations performed at the mhs-doc-xfer port, between a TLMAU and a TLM terminal. The concrete interactions, which correspond to abstract operations, are realized as telematic access protocol data units (TAPDUs).
+
+It should be noted that the TLMAU may not support all the conditional TAPDUs and all the optional elements or parameters of a TAPDU. The actual support of the TAPDUs and parameters depends on the application and the version of the colocated MTA.
+
+The relationship between abstract operations at the mhs-doc-xfer port and associated TAPDUs are summarized in Table 2/T.330.
+
+## **10.1 Description of TAPDU**
+
+### **10.1.1 MessageSend**
+
+A TLM terminal sends a Send-TAPDU to invoke the MessageSend abstract operation. The TLMAU returns a SendAck-TAPDU to report the result of that operation, or may return an Exception-TAPDU (§ 10.1.1.3) to report an abstract error.
+
+TABLE 2/T.330
+
+#### **Relationship between abstract operation and TAPDU**
+
+| mhs-doc-xfer Abstract operation | TAPDU                          |              | Direction of transfer       |
+|---------------------------------|--------------------------------|--------------|-----------------------------|
+| Operation                       | TAPDU Name                     | TLMAU Status | TLM $\leftrightarrow$ TLMAU |
+| MessageSend                     | (O) Send-TAPDU                 | M            | →                           |
+|                                 | (R) SendAck-TAPDU              | C            | ←                           |
+|                                 | (E) Exception-TAPDU            | M            | ←                           |
+| MessageProbe                    | (O) Probe-TAPDU                | C            | →                           |
+|                                 | (R) ProbeAck-TAPDU             | C            | ←                           |
+|                                 | (E) Exception-TAPDU            | C            | ←                           |
+| ExplicitReceive                 | (O) ExplicitRN-TAPDU           | C            | →                           |
+|                                 | (R) ExplicitRNAck-TAPDU        | C            | ←                           |
+|                                 | (E) Exception-TAPDU            | C            | ←                           |
+| MessageCancel                   | (O) Cancel-TAPDU               | C            | →                           |
+|                                 | (R) –                          | –            |                             |
+|                                 | (E) Exception-TAPDU            | C            | ←                           |
+| MessageDeliver                  | (O) Deliver-TAPDU              | M            | ←                           |
+| ReceiptStatusNotice             | (O) ReceiptStatusNotice-TAPDU  | M            | ←                           |
+| DeliveryStatusNotice            | (O) DeliveryStatusNotice-TAPDU | M            | ←                           |
+| Register                        | (O) Register-TAPDU             | C            | →                           |
+|                                 | (R) RegisterAck-TAPDU          | C            | ←                           |
+|                                 | (E) Exception-TAPDU            | C            | ←                           |
+| DSLlist                         | (O) DSQuery-TAPDU              | C            | →                           |
+|                                 | (R) DSReport-TAPDU             | C            | ←                           |
+|                                 | (E) Exception-TAPDU            | C            | ←                           |
+| DSDelete                        | (O) MessageDelete-TAPDU        | C            | →                           |
+|                                 | (R) –                          | –            |                             |
+|                                 | (E) Exception-TAPDU            | C            | ←                           |
+| DSFetch                         | (O) OutputRequest-TAPDU        | C (Note 1)   | →                           |
+|                                 | (R) OutputMessage-TAPDU        | C (Note 1)   | ←                           |
+|                                 | (E) Exception-TAPDU            | C (Note 1)   | ←                           |
+| MessageStatus                   | (O) StatusQuery-TAPDU          | C            | →                           |
+|                                 | (R) StatusReport-TAPDU         | C            | ←                           |
+|                                 | (E) Exception-TAPDU            | C            | ←                           |
+
+O Argument      R Result                      E Error
+
+M Mandatory      C Conditional
+
+*Note 1* – In cases where TLMAU provides DS, these TAPDU are mandatory.
+
+*Note 2* – A message may arrive at a TLM terminal as a result of either a Deliver-TAPDU or OutputMessage-TAPDU. The Deliver-TAPDU is applicable when delivery occurs directly to a TLM terminal. The OutputMessage-TAPDU is only applicable in the case that DS is subscribed.
+
+#### 10.1.1.1 *Send-TAPDU*
+
+The Send-TAPDU comprises the following elements:
+
+| Send-TAPDU                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |  |
+|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--|
+| <pre> Send-TAPDU ::= SEQUENCE {     [0] SEQUENCE {         send [0] SendTAPDUId,         [1] SEQUENCE {             quantityOfDocs          QuantityOfDocsElementId,             number-of-docs          NumberOfAssociatedDocuments } OPTIONAL },     -- See Note 1     [1] SET {         [0] SEQUENCE {             priority                  PriorityElementId,             priority-ind              PriorityValue DEFAULT normal } OPTIONAL,         [1] SEQUENCE {             perMessageIndicators      PerMessageIndicatorsElementId,             SEQUENCE {                 deferred-delivery-time [0] DateandTime OPTIONAL,                 [1] SET {                     disclose-recipients      [0] DiscloseRecipientsValue OPTIONAL,                     alternate-recipient-allowed [1] AlternateRecipientAllowedValue OPTIONAL,                     recipient-reassignment-prohibited [2] ReassignmentValue OPTIONAL }}} OPTIONAL,         [2] SEQUENCE {             conversion                  ConversionElementId,             conversion-info             ConversionInfoValue } OPTIONAL,         [3] SEQUENCE {             contentinfo                  ContentInfoElementId,             content-return-request       ContentReturnRequestValue } OPTIONAL,         [4] SEQUENCE {             returnAddress                ReturnAddressElementId,             postal-address                PostalAddressValue OPTIONAL,         [5] SEQUENCE {             latestdelivery                LatestDeliveryElementId,             latest-delivery-time          DateandTime } OPTIONAL },         [6] SEQUENCE {             to                            ToElementId,             SET OF SEQUENCE {                 primary-recipient [0] ORDescriptor,                 [1] RecOptions }}} OPTIONAL,     -- See Note 2         [7] SEQUENCE {             cc                            CCElementId,             SET OF SEQUENCE {                 copy-recipient [0] ORDescriptor,                 [1] RecOptions }}} OPTIONAL,     -- See Note 2         [8] SEQUENCE {             bcc                            BCCElementId,             SET OF SEQUENCE {                 blind-copy-recipient [0] ORDescriptor,                 [1] RecOptions }}} OPTIONAL },     -- See Note 2 </pre> |  |
+
+##### Send-TAPDU (continued)
+
+-- Send-TAPDU Definition (continued)
+
+```
+[2] SET {
+    [0] SEQUENCE {
+        thisIPM                                ThisIPMElementId,
+        this-ipm-id                            IPMIdentifier } OPTIONAL,
+    -- See Note 3
+    [1] SEQUENCE {
+        from                                    FromElementId,
+        originating-user                       ORDescriptor } OPTIONAL,
+    [2] SEQUENCE {
+        authorizing                            AuthorizingElementId,
+        SET OF
+        authorizing-user                       OrDescriptor } OPTIONAL,
+    [3] SEQUENCE {
+        repliedToIPM                           RepliedToIPMElementId,
+        replied-to-ipm-id                     IPMIdentifier } OPTIONAL,
+    [4] SEQUENCE {
+        obsoletedIPMs                         ObsoletedIPMsElementId,
+        SEQUENCE OF
+        obsoleted-ipm-id                     IPMIdentifier } OPTIONAL,
+    [5] SEQUENCE {
+        relatedIPMs                           RelatedIPMsElementId,
+        SEQUENCE OF
+        related-ipm-id                     IPMIdentifier } OPTIONAL,
+    [6] SEQUENCE {
+        subject                                SubjectElementId,
+        subject-content                       SubjectContent } OPTIONAL,
+    [7] SEQUENCE {
+        contentIndicator                      ContentIndicatorElementId,
+        SEQUENCE {
+            expiry-time [0] DateandTime OPTIONAL,
+            [1] SET {
+                importance [0] ImportanceValue DEFAULT normal,
+                sensitivity [1] SensitivityValue OPTIONAL }}} OPTIONAL,
+    [8] SEQUENCE {
+        reply                                  ReplyElementId,
+        SEQUENCE {
+            reply-time[0] DateandTime,
+            [1] SET OF {
+                reply-recipient                ORDescriptor }} OPTIONAL,
+    [9] SEQUENCE {
+        language                              LanguageElementId,
+        language-ind                          LanguagueInd } OPTIONAL,
+MsgIncomplete [10] MsgIncompleteElementId OPTIONAL },
+-- Body
+[3] SET {
+    [0] SEQUENCE {
+        BodyType                              BodyTypeElementId,
+        SET OF {
+            Body-part                         BodyPartValue } OPTIONAL }}
+```
+
+##### Send-TAPDU (end)
+
+-- *Send-TAPDU Definition (continued)*
+
+-- *Definition of RecOptions*
+
+*RecOptions* ::= SET {
+
+|                                          |                                                |
+|------------------------------------------|------------------------------------------------|
+| user-report-request                      | [1] UserReportRequestValue OPTIONAL,           |
+| explicit-conversion                      | [2] ExplicitConversionValue OPTIONAL OPTIONAL, |
+| rn-request                               | [3] RNRequestValue OPTIONAL,                   |
+| nrn-request                              | [4] NRNRequestValue OPTIONAL,                  |
+| return-request                           | [5] ReturnRequestValue OPTIONAL,               |
+| reply-request                            | [6] ReplyRequestValue DEFAULT noReply,         |
+| requested-delivery-method                | [7] RequestedDelValue OPTIONAL,                |
+| terminal-type                            | [8] TerminalTypeValue OPTIONAL,                |
+| physical-forwarding-prohibited           | [9] PhyForProhibValue OPTIONAL,                |
+| physical-forwarding-address-request      | [10] PhyforAdrValue OPTIONAL,                  |
+| physical-delivery-modes                  | [11] PhyDelModValue OPTIONAL,                  |
+| registered-mail-type                     | [12] RegMailTypeValue OPTIONAL,                |
+| recipient-number-for-advice              | [13] RecNumAdvValue OPTIONAL,                  |
+| physical-delivery-report-request         | [14] PhyDelRepValue OPTIONAL,                  |
+| originator-requested-alternate-recipient | [15] OrgRecAltValue OPTIONAL,                  |
+
+*Note 1* – This element must be present when ControllInfo is conveyed by a normal document and more than one TAPDU are conveyed in this session.
+
+*Note 2* – OR Descriptor must contain an ORAddress and at least one of these addresses must be present.
+
+*Note 3* – When this element is omitted, the TLMAU shall construct this component which consists of the following components: originator name, date and time, and if necessary, a sequence number.
+
+#### 10.1.1.2 *SendAck-TAPDU*
+
+The SendAck-TAPDU comprises the following elements:
+
+| SendAck-TAPDU                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |  |
+|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--|
+| <pre> SendAck-TAPDU ::= SEQUENCE {   [0] SEQUENCE {     sendAck [0] SendAckTAPDUId,     [1] SEQUENCE {       correlationInfo          CorrelationInfoElementId,       call-id                  CallIdentification },   -- See Note   [1] SET {     [0] SEQUENCE {       submissionId             SubmissionIdElementId,       submission-msg-id        MessageIdentifier },     [1] SEQUENCE {       submissionTime            SubmissionTimeElementId,       submission-time           DateandTime }}} </pre> |  |
+
+*Note* – This element is a session connection information that identifies previous Send-TAPDU being reported on.
+
+#### 10.1.1.3 *Exception-TAPDU*
+
+The Exception- TAPDU comprises the following elements:
+
+| Exception-TAPDU                                                                                                                                                                                                                                                                                                                                                     |  |
+|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--|
+| <pre> Exception-TAPDU ::= SEQUENCE {   [0] SEQUENCE {     exception [0] ExceptionTAPDUId,     [1] SEQUENCE {       correlationInfo          CorrelationInfoElementId,       call-id                  CallIdentification },   -- See Note   [2] SEQUENCE {     errors                     ErrorsElementId,     error-cause                ErrorCauseValue }}} </pre> |  |
+
+*Note* – This element is a session connection information that identifies associated TAPDU being reported on e.g. Send-TAPDU.
+
+### 10.1.2 *MessageProbe*
+
+A TLM terminal sends a Probe-TAPDU to invoke the MessageProbe abstract operation. The TLMAU returns a ProbeAck-TAPDU to report the result of that operation, or may return an Exception-TAPDU (§ 10.1.1.3) to report an abstract error.
+
+#### 10.1.2.1 *Probe-TAPDU*
+
+The Probe-TAPDU comprises the following elements:
+
+| Probe-TAPDU                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
+|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| <pre> Probe-TAPDU ::= SEQUENCE {   [0] SEQUENCE {     probe [0] ProbeTAPDUId,     [1] SEQUENCE {       quantityOfDocs          QuantityOfDocsElementId,       number-of-docs          NumberOfAssociatedDocuments } OPTIONAL },   [1] SET {     -- Continuation see send-TAPDU.     -- Note that only few elements of the Send-TAPDU are relevant for a Probe-TAPDU.     -- Not relevant elements will be ignored.     -- At least one recipient must be present. </pre> |
+
+#### 10.1.2.2 *ProbeAck-TAPDU*
+
+The ProbeAck-TAPDU comprises the following elements:
+
+| ProbeAck-TAPDU                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
+|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| <pre> ProbeAck-TAPDU ::= SEQUENCE {   [0] SEQUENCE {     probeAck [0] ProbeAckTAPDUId,     [1] SEQUENCE {       correlationInfo          CorrelationInfoElementId,       call-id                  CallIdentification }},   [1] SET {     [0] SEQUENCE {       probeId                  ProbeElementId,       probe-msg-id             MessageIdentifier },     [1] SEQUENCE {       submissionTime            SubmissionTimeElementId,       submission-time           DateandTime }}} </pre> |
+
+### 10.1.3 *ExplicitReceive*
+
+A TLM terminal sends an ExplicitRN-TAPDU to invoke the ExplicitReceive abstract operation. The TLMAU returns an ExplicitRNAck-TAPDU to report the result of that operation, or may return an Exception-TAPDU (see § 10.1.1.3), to report an abstract error.
+
+#### 10.1.3.1 *ExplicitRN-TAPDU*
+
+The ExplicitRN-TAPDU comprises the following elements:
+
+| ExplicitRN-TAPDU                |                                          |
+|---------------------------------|------------------------------------------|
+| ExplicitRN-TAPDU ::= SEQUENCE { |                                          |
+| [0]                             | explicitRN                               |
+| [1] SET {                       | ExplicitRNTAPDUId,                       |
+| [0] SEQUENCE {                  | RecipientsElementId,                     |
+| recipients                      | ORName },                                |
+| recipient-name                  |                                          |
+| [1] SEQUENCE {                  | PriorityElementId,                       |
+| priority                        | PriorityValue DEFAULT normal } OPTIONAL, |
+| priority-ind                    |                                          |
+| [2] SEQUENCE {                  | SubjectIPMElementId,                     |
+| subjectIPM                      | IPMIdentifier { OPTIONAL,                |
+| subject-ipm-id                  |                                          |
+| [3] SEQUENCE {                  | IPNOriginatorElementId,                  |
+| IPNOriginator                   | ORDescriptor } OPTIONAL,                 |
+| ipn-originating-user            |                                          |
+| [4] SEQUENCE {                  | TimeOfReceiptElementId,                  |
+| timeOfReceipt                   | DateandTime } OPTIONAL,                  |
+| receipt-time                    |                                          |
+| [5] SEQUENCE {                  | ConvertedInfoTypesElementId,             |
+| convertedInfoTypes              | SET OF                                   |
+| eIT                             | EITValue } OPTIONAL }}                   |
+
+*Note* – If receipt-time element defined in Receipt is omitted, TLMAU extracts one from the CES of the session in which this TAPDU was transferred. This may differ from the time of actual receipt of IPM.
+
+#### 10.1.3.2 *ExplicitRNack-TAPDU*
+
+The ExplicitRNack-TAPDU comprises the following elements:
+
+| ExplicitRNack-TAPDU                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |  |
+|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--|
+| <pre> ExplicitRN-TAPDU ::= SEQUENCE {   [0] SEQUENCE {     explicitRNack [0] ExplicitRNTAPDUId,     [1] SEQUENCE {       correlationInfo          CorrelationInfoElementId,       call-id                  CallIdentification }},   [1] SET {     [0] SEQUENCE {       submissionId             SubmissionElementId,       submission-msg-id        MessageIdentifier },     [1] SEQUENCE {       submissionTime           SubmissionTimeElementId,       submission-time          DateandTime }}} </pre> |  |
+
+### 10.1.4 *MessageCancel*
+
+A TLM terminal sends a Cancel-TAPDU to invoke the MessageCancel abstract operation. The TLMAU returns no TAPDU to report the result of that operation, or may return an Exception-TAPDU (see § 10.1.1.3), to report an abstract error.
+
+#### 10.1.4.1 *Cancel-TAPDU*
+
+The Cancel-TAPDU comprises the following elements:
+
+| Cancel-TAPDU                                                                                                                                                                                                                                                                                                                                                                  |  |
+|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--|
+| <pre> Cancel-TAPDU ::= SEQUENCE {   cancel [0] CancelTAPDUId,   [1] SEQUENCE {     submissionId             SubmissionIdElementId,     submission-msg-id        MessageIdentifier } OPTIONAL,   [2] SEQUENCE {     correlation-Info          Correlation-InfoElementId,     call-id                  CallIdentification } OPTIONAL }  -- one of these must be present. </pre> |  |
+
+### 10.1.5 MessageDeliver
+
+A TLMAU sends a Deliver-TAPDU to invoke the MessageDeliver abstract operation.
+
+#### 10.1.5.1 Deliver-TAPDU
+
+The Deliver-TAPDU comprises the following elements:
+
+| Deliver-TAPDU                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |  |
+|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--|
+| <pre> Deliver-TAPDU ::= SEQUENCE {   [0] SEQUENCE {     deliver [0] DeliverTAPDUId,     [1] SEQUENCE {       quantityOfDocs       number-of-docs       QuantityOfDocsElementId,       NumberOfAssociatedDocuments } OPTIONAL },   -- MTS parameters   [1] SET {     [0] SEQUENCE {       priority       priority-ind       PriorityElementId,       PriorityValue DEFAULT normal } OPTIONAL },     [1] SEQUENCE {       originator       originator-name       OriginatorElementId,       ORName } OPTIONAL,     [2] SEQUENCE {       thisRecipient       this-recipient-name       ThisRecipientElementId,       ORName },     [3] SEQUENCE {       orgIntendedRecipient       org-intended-recipient-name       OrgIntendedRecipientElementId,       ORName } OPTIONAL,     [4] SEQUENCE {       otherRecipients       SET OF       otherRecipient-name       OtherRecipientsElementId,       ORName } OPTIONAL,     [5] SEQUENCE {       redirectedfrom       SEQUENCE OF       redirected-from       RedirectedFromElementId,       ORName } OPTIONAL,     [6] SEQUENCE {       submissionTime       submission-time       SubmissionTimeElementId,       DateandTime },     [7] SEQUENCE {       deliveryId       delivery-msg-id       DeliveryElementId,       MessageIdentifier } OPTIONAL,     [8] SEQUENCE {       conversionIndication       SET {         [0] SET OF         eIT         EITValue OPTIONAL }}       conversion-prohibited [1] ConversionProhibitedValue OPTIONAL },     [9] SEQUENCE {       convertedInfoTypes       SET OF       eIT       ConvertedInfoTypesElementId,       EITValue }},   }</pre> |  |
+
+##### Deliver-TAPDU (continued)
+
+-- Deliver-TAPDU Definition (continued)
+
+-- IPMS parameters
+
+```
+
+[2] SET {
+    [0] SEQUENCE {
+        thisIPM                                     ThisIPMElementId,
+        this-ipm-id                                 IPMIdentifier },
+    [1] SEQUENCE {
+        from                                         FromElementId,
+        originating-user                            OrDescriptor } OPTIONAL,
+    [2] SEQUENCE {
+        authorizing                                 AuthorizingElementId,
+        SET OF
+        authorizing-user                            ORDescriptor } OPTIONAL,
+    [3] SEQUENCE {
+        to                                           ToElementId,
+        SET OF SEQUENCE {
+            primary-recipient [0] ORDescriptor,
+            [1] NotificationSpecification }} OPTIONAL,
+    [4] SEQUENCE {
+        cc                                           CCElementId,
+        SET OF SEQUENCE {
+            copy-recipient [0] ORDescriptor,
+            [1] NotificationSpecification }} OPTIONAL,
+    [5] SEQUENCE {
+        bcc                                           BCCElementId,
+        SET OF SEQUENCE {
+            blind-copy-recipient [0] ORDescriptor,
+            [1] NotificationSpecification }} OPTIONAL,
+    [6] SEQUENCE {
+        repliedToIPM                                RepliedToIPMElementId,
+        replied-to-ipm-id                            IPMIdentifier } OPTIONAL,
+    [7] SEQUENCE {
+        obsoletedIPMs                               ObsoletedIPMsElementId,
+        SET OF
+        obsoleted-ipm-id                            IPMIdentifier } OPTIONAL,
+    [8] SEQUENCE {
+        relatedIPMs                                 RelatedIPMsElementId,
+        SET OF
+        related-ipm-id                              IPMIdentifier } OPTIONAL,
+    [9] SEQUENCE {
+        subject                                       SubjectElementId,
+        subject-content                             SubjectContent } OPTIONAL,
+    [10] SEQUENCE {
+        contentIndicator                             ContentIndicatorElementId,
+        SEQUENCE {
+            expiry-time    [0] DateandTime OPTIONAL,
+                        [1] SET {
+            importance     [0] ImportanceValue DEFAULT normal,
+            sensitivity     [1] SensitivityValue OPTIONAL,
+            auto-forwarded [2] AutoForwardedValue DEFAULT
+                        notAutoForward }}} OPTIONAL,
+
+```
+
+| Deliver-TAPDU ( <i>end</i> )                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |  |
+|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--|
+| <pre> -- Deliver-TAPDU Definition (continued)     [11] SEQUENCE {         reply             SEQUENCE {                 reply-time [0] DateandTime,                 [1] SET OF                     reply-recipient                         ORDescriptor }} OPTIONAL,     [12] SEQUENCE {         language             LanguageElementId,         language-ind             LanguageInd } OPTIONAL, MsgIncomplete [13] MsgIncompleteElementId OPTIONAL },     -- Body     [3] SEQUENCE {         [0] SEQUENCE {             bodyType                 BodyTypeElementId,             body-part                 BodyPartValue } OPTIONAL,         [1] SEQUENCE {             forwardedInfo                 ForwardedInfoElementId,             SEQUENCE {                 forwarded-time [0] DateandTime,                 [1] DeliveryEnvelope }} OPTIONAL,      -- Delivery Envelope contains same set of MTS parameters of Deliver-TAPDU}} </pre> |  |
+| <pre> -- Definition of Notification Specification Notification Specification ::= SET {     rn-request      [0] RNRequestValue OPTIONAL,     nrn-request     [1] NRNRequestValue OPTIONAL,     return-request  [2] ReturnRequestValue OPTIONAL,     reply-request   [3] ReplyRequestValue DEFAULT                     noReply } </pre>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |  |
+
+### 10.1.6 *ReceiptStatusNotice*
+
+A TLMAU terminal sends a ReceiptStatusNotice-TAPDU to invoke the ReceiptStatusNotice abstract operation.
+
+#### 10.1.6.1 *ReceiptStatusNotice-TAPDU*
+
+The ReceiptStatusNotice-TAPDU comprises the following elements:
+
+##### ReceiptStatusNotice-TAPDU
+
+```
+
+ReceiptStatusNotice-TAPDU ::= SEQUENCE {
+  [0] SEQUENCE {
+    receiptStatusNotice [0] ReceiptStatusNoticeTAPDUId,
+    [1] SEQUENCE {
+      quantityOfDocs      QuantityOfDocsElementId,
+      number-of-docs      NumberOfAssociatedDocuments } OPTIONAL },
+  -- MTS parameters
+  [1] SET {
+    [0] SEQUENCE {
+      priority      PriorityElementId,
+      priority-ind  PriorityValue },
+    [1] SEQUENCE {
+      deliveryId    DeliveryIdElementId,
+      delivery-id   MessageIdentifier } OPTIONAL,
+    [2] SEQUENCE {
+      originator    OriginatorElementId,
+      originator-name ORName } OPTIONAL,
+    [3] SEQUENCE {
+      thisRecipient ThisRecipientElementId,
+      this-recipient-name ORName },
+    [4] SEQUENCE {
+      submissionTime SubmissionTimeElementId,
+      submissionTime DateandTime },
+    [5] SEQUENCE {
+      timeOfDelivery TimeOfDeliveryElementId,
+      delivery-time   DateandTime },
+    [6] SEQUENCE {
+      conversionIndication ConversionIndicationElementId,
+      SET {
+        [0] SET OF
+          eIT      EITValue } OPTIONAL }}
+    conversion-prohibited [1] ConversionProhibitedValue OPTIONAL },
+    [7] SEQUENCE {
+      convertedInfotypes      ConvertedInfoTypesElementId,
+      SET OF
+        elt      EITValue },
+  --IPMS parameters
+  [2] SET {
+    [0] SEQUENCE {
+      notificationType      NotificationTypeElementId,
+      report-type           ReportTypeValue },
+    [1] SEQUENCE {
+      subjectIPM            SubjectIPMElementId,
+      subject-ipm-id        IPMIdentifier },
+    [2] SEQUENCE {
+      IPNOriginator         IPNOriginatorElementId,
+      ipn-originating-user  ORDescriptor } OPTIONAL,
+    [3] SEQUENCE {
+      preferredRecipient     PreferredRecipientElementId,
+      preferred-recipient    ORDescriptor } OPTIONAL,
+  }
+
+```
+
+##### ReceiptStatusNotice-TAPDU (end)
+
+-- *ReceiptStatusNotice-TAPDU Definition (continued)*
+
+```
+
+[4] SET {
+    [0] SEQUENCE {
+        timeOfReceipt          TimeOfReceiptElementId,
+        receipt-time           DateandTime },
+    [1] SEQUENCE {
+        typeOfReceipt          TypeOfReceiptElementId,
+        type-of-receipt        TypeOfReceiptValue DEFAULT manual } OPTIONAL,
+    [2] SEQUENCE {
+        supplReceiptInfo       SupplReceiptInfoElementId,
+        suppl-receipt-info     SupplementaryInformation } OPTIONAL } OPTIONAL,
+[5] SET {
+    [0] SEQUENCE {
+        nonReceiptInfo         NonReceiptInfoElementId,
+        SET {
+            non-receipt-reason [0] NonReceiptReasonValue,
+            discard-reason    [1] DiscardReasonValue OPTIONAL }} OPTIONAL,
+    [1] SEQUENCE {
+        comments               CommentElementId,
+        comments               Comment },
+messageReturnedInd [2] MessageReturnedIndElementId OPTIONAL }}}
+
+```
+
+### 10.1.7 *DeliveryStatusNotice*
+
+A TLMAU terminal sends a DeliveryStatusNotice-TAPDU to invoke the DeliveryStatusNotice abstract operation.
+
+#### 10.1.7.1 *DeliveryStatusNotice-TAPDU*
+
+The DeliveryStatusNotice-TAPDU comprises the following elements:
+
+##### DeliveryStatusNotice-TAPDU
+
+```
+
+DeliveryStatusNotice-TAPDU ::= SEQUENCE {
+  [0] SEQUENCE {
+    deliveryStatusNotice [0] DeliveryStatusNoticeTAPDUId,
+    [1] SEQUENCE {
+      quantityOfDocs      QuantityOfDocsElementId,
+      number-of-docs      NumberOfAssociatedDocuments } OPTIONAL },
+    [2] SEQUENCE {
+      correlationInfo      CorrelationInfoElementId,
+      call-id              CallIdentification },
+  [1] SET {
+    [0] SEQUENCE {
+      submissionId          SubmissionIdElementId,
+      submission-msg-id      MessageIdentifier } OPTIONAL,
+    [1] SEQUENCE {
+      probeId              ProbeIdElementId,
+      submission-msg-id      MessageIdentifier } OPTIONAL,
+    [2] SET OF {
+      [0] SEQUENCE {
+        reportedRecipient      ReportedRecipientElementId,
+        reported-recipient-name ORName },
+      [1] SEQUENCE {
+        notificationType        NotificationTypeElementId,
+        report-type              ReportTypeValue },
+      [2] SEQUENCE {
+        intendedRecipient        IntendedRecipientElementId,
+        intended-recipient-name  ORName },
+      [3] SEQUENCE {
+        convertedInfoTypes      ConvertedInfoTypesElementId,
+        SET OF
+        eIT                      EITValue },
+      [4] SET {
+        -- In case of Delivery Notification,
+        -- this set of element shall be present.
+        [0] SEQUENCE {
+          timeOfDelivery          TimeOfDeliveryElementId,
+          delivery-time            DateandTime },
+        [1] SEQUENCE {
+          typeOfUA                TypeOfUAElementId,
+          type-of-ua              TypeOfUA DEFAULT public } OPTIONAL,
+        [2] SEQUENCE {
+          supplInfo                SupplInfoElementId,
+          suppl-info              SupplementaryInformation } OPTIONAL,
+        [5] SET {
+          -- In case of Non Delivery Notification,
+          -- this set of element shall be present.
+          [0] SEQUENCE {
+            nonDeliveryReason      NonDeliveryReasonElementId,
+            SET {
+              reason-code          [0] ReasonCodeValue,
+              diagnostic-code      [1] DiagnosticCodeValue OPTIONAL }}} OPTIONAL },
+    contentReturned [3] ContentReturnedElementId OPTIONAL }}
+
+```
+
+### 10.1.8 Register
+
+A TLM terminal sends a Register-TAPDU to invoke the register abstract operation. The TLMAU returns a RegisterAck-TAPDU, if necessary, to report the result of that operation, or may return an Exception-TAPDU (see § 10.1.1.3) to report an abstract error.
+
+#### 10.1.8.1 Register-TAPDU
+
+The Register-TAPDU comprises the following elements:
+
+| Register-TAPDU                |                         |                                                           |
+|-------------------------------|-------------------------|-----------------------------------------------------------|
+| Register-TAPDU ::= SEQUENCE { |                         |                                                           |
+| [0]                           | register                | TAPDUIdValue,                                             |
+| [1] SET {                     |                         |                                                           |
+| [0] SET {                     |                         |                                                           |
+| [0] SEQUENCE {                | expiredDiscard          | ExpiredDiscardElementId,                                  |
+|                               | discard-ipm             | DiscardValue DEFAULT discard } OPTIONAL,                  |
+| [1] SEQUENCE {                | obsoleteDiscard         | ObsoleteDiscardElementId,                                 |
+|                               | discard-ipm             | DiscardValue DEFAULT discard } OPTIONAL },                |
+| [1] SET {                     |                         |                                                           |
+| [0] SEQUENCE {                | autoFWDIPMs             | AutoFWDIPMsElementId,                                     |
+|                               | auto-fwd-ipms           | AutoFWDIPMsValue DEFAULT not-auto-forward } OPTIONAL,     |
+| [1] SEQUENCE {                | autoFWDRecipients       | AutoFWDRecipientsElementId,                               |
+|                               | SET OF {                |                                                           |
+|                               | auto-fwd-recipient-name | ORName } } OPTIONAL,                                      |
+| [2] SEQUENCE {                | autoFWDHeading          | AutoFWDHeadingElementId,                                  |
+|                               | auto-fwd-heading        | AutoFWDHeading } OPTIONAL,                                |
+| <i>-- For further study</i>   |                         |                                                           |
+| [3] SEQUENCE {                | autoFWDComment          | AutoFWDCommentElementId,                                  |
+|                               | auto-fwd-comment        | AutoFWDComment } OPTIONAL },                              |
+| [2] SET {                     |                         |                                                           |
+| [0] SEQUENCE {                | dsMode                  | DSModeElementId,                                          |
+|                               | ds-mode                 | DSModeValue } OPTIONAL,                                   |
+| [1] SEQUENCE {                | tLMAUOperation          | TLMAUOperationElementId,                                  |
+|                               | SET {                   |                                                           |
+|                               | error-recovery-mode     | [0] ErrorRecoveryModeValue OPTIONAL,                      |
+|                               | auto-acknowledgment     | [1] AutoAcknowledgment DEFAULT manual } } OPTIONAL,       |
+| [2] SEQUENCE {                | supplRecipientInfo      | SupplRecipientInfoElementId,                              |
+|                               | suppl-recipient-info    | SupplementaryInformation } OPTIONAL,                      |
+| [3] SEQUENCE {                | autoOutput              | AutoOutputElementId,                                      |
+|                               | SET {                   |                                                           |
+|                               | frequency               | [0] Frequency OPTIONAL,                                   |
+|                               | output-time             | [1] DateandTime OPTIONAL } } OPTIONAL,                    |
+| [4] SEQUENCE {                | messageDeleteMode       | MessageDeleteModeElementId,                               |
+|                               | message-delete-mode     | MessageDeleteModeValue DEFAULT auto-delete } OPTIONAL } } |
+
+#### 10.1.8.2 RegisterAck-TAPDU
+
+The RegisterAck-TAPDU comprises the following elements:
+
+| RegisterAck-TAPDU     |                    |
+|-----------------------|--------------------|
+| RegisterAck-TAPDU ::= |                    |
+| registerAck           | RegisterAckTAPDUId |
+
+### 10.1.9 DSList
+
+A TLM terminal sends a DSQuery-TAPDU to invoke the DSList abstract operation. The TLMAU returns a DSReport-TAPDU to report the result of that operation, or may return an Exception-TAPDU (see § 10.1.1.3) to report an abstract error.
+
+#### 10.1.9.1 DSQuery-TAPDU
+
+The DSQuery-TAPDU comprises the following elements:
+
+| DSQuery-TAPDU     |                |
+|-------------------|----------------|
+| DSQuery-TAPDU ::= |                |
+| dsQuery           | DSQueryTAPDUId |
+
+#### 10.1.9.2 DSReport-TAPDU
+
+The DSReport-TAPDU comprises the following elements:
+
+| DSReport-TAPDU                |                                          |
+|-------------------------------|------------------------------------------|
+| DSReport-TAPDU ::= SEQUENCE { |                                          |
+| [0]                           | dsReport                                 |
+| [1] SET OF {                  | DSReportTAPDUId,                         |
+| [0] SEQUENCE {                | RetrievalIdElementId,                    |
+| retrievalId                   | RetrievalIdentifier },                   |
+| [1] SEQUENCE {                | MessageTypeElementId,                    |
+| messageType                   | MessageTypeValue },                      |
+| [2] SEQUENCE {                | OriginatorElementId,                     |
+| originator                    | ORName } OPTIONAL,                       |
+| [3] SEQUENCE {                | PriorityElementId,                       |
+| priority                      | PriorityValue DEFAULT normal } OPTIONAL, |
+| [4] SEQUENCE {                | MessageLengthElementId,                  |
+| messageLength                 | MessageLength } OPTIONAL}}               |
+
+### 10.1.10 *DSDelete*
+
+A TLM terminal sends a MessageDelete-TAPDU to invoke the DSDelete abstract operation. The TLMAU returns no TAPDU to report the result of that operation, or may return an Exception-TAPDU (see § 10.1.1.3) to report an abstract error.
+
+#### 10.1.10.1 *MessageDelete-TAPDU*
+
+The MessageDelete-TAPDU comprises the following elements:
+
+| MessageDelete-TAPDU                                                                                                                                                                                                                                          |  |
+|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--|
+| MessageDelete-TAPDU ::= SEQUENCE {<br>messageDelete [0] MessageDeleteTAPDUId,<br>[1] SEQUENCE {<br>SET OF {           messageSelector                           MessageSelectorElementId,<br>retrieval-id                            RetrievalIdentifier }}} |  |
+
+### 10.1.11 *DSFetch*
+
+A TLM terminal sends an OutputRequest-TAPDU to invoke the DSFetch abstract operation. The TLMAU returns an OutputMessage-TAPDU to report the result of that operation, or may return an Exception-TAPDU (see § 10.1.1.3) to report an abstract error.
+
+The OutputMessage-TAPDU is sent by TLMAU to be output the message from DS. This TAPDU is triggered by one of the following events:
+
+- 1) some rule (not defined in this Recommendation) which causes TLMAU to establish a connection to the TLM terminal and to send a message at a specific time, for example, the TLM terminal has registered its times of availability with TLMAU;
+- 2) the TLM terminal establishes a connection to TLMAU and initiates a CSCC which is taken as an implicit request for output by TLMAU;
+- 3) receipt of an OutputRequest-TAPDU.
+
+#### 10.1.11.1 *OutputRequest-TAPDU*
+
+The OutputRequest-TAPDU comprises the following elements:
+
+| OutputRequest-TAPDU                                                                                                                                                                                                                                                                                                                                                                                                                                                 |  |
+|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--|
+| OutputRequest-TAPDU ::= SEQUENCE {<br>[0]                   outputRequest                           OutputRequestTAPDUId,<br>[1] SET OF SEQUENCE {<br>[0] SEQUENCE {<br>retrievalId                           RetrievalIdElementId,<br>retrieval-id                         RetrievalIdentifier },<br>[1] SEQUENCE {<br>deleteAfterOutput                   DeleteAfterOutputElementId,<br>delete-after-output                 DeleteAfterOutputValue } OPTIONAL }} |  |
+
+#### 10.1.11.2 OutputMessage-TAPDU
+
+The OutputMessage-TAPDU comprises the following elements:
+
+| OutputMessage-TAPDU                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |  |
+|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--|
+| <pre> OutputMessage-TAPDU ::= SEQUENCE {   [0] SEQUENCE {     outputMessage [0] OutputMessageTAPDUId,     [1] SEQUENCE {       quantityOfDocs                      QuantityOfDocsElementId,       number-of-docs                      NumberOfAssociatedDocuments } OPTIONAL },   [1] SET OF SEQUENCE {     [0] SEQUENCE {       retrievalId                        RetrievalIdElementId,       retrieval-id                        RetrievalIdentifier }     [1] SEQUENCE {       messageType                        MessageTypeElementId,       message-type                       MessageTypeValue }     [2] SEQUENCE {       timeOfDelivery                     TimeOfDeliveryElementId,       delivery-time                      DateandTime }      -- The remaining Components of this TAPDU are identical to the components in the Deliver,     DeliverStatusNotice and ReceiptStatusNotice-TAPDU. The actual components to be used depend upon the     MessageType parameter value specified in the MessageType component. }} </pre> |  |
+
+*Note* – The RetrievalIdentifier is an identifier which identifies a message in DS.
+
+### 10.1.12 MessageState
+
+A TLM terminal sends a StatusQuery-TAPDU to invoke the MessageState abstract operation. The TLMAU returns a StatusReport-TAPDU to report the result of that operation, or returns an Exception-TAPDU to report an abstract error.
+
+#### 10.1.12.1 StatusQuery-TAPDU
+
+The StatusQuery-TAPDU comprises the following elements:
+
+| StatusQuery-TAPDU                                                                                                                                                                                                                                                                                                                                                                                                                                                                |  |
+|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--|
+| <pre> StatusQuery-TAPDU ::= SEQUENCE {   [0]     statusQuery                        StatusQueryTAPDUId,   [1] SET {     [0] SEQUENCE {       submissionId                      SubmissionIdElementId,       submission-msg-id                 MessageIdentifier } OPTIONAL,     -- See Note     [1] SEQUENCE {       correlationInfo                   CorrelationInfoElementId,       call-id                           CallIdentification } OPTIONAL }}     -- See Note </pre> |  |
+
+*Note* – If none of these are present all outstanding (in operation) operations will be reported.
+
+#### 10.1.12.2 StatusReport-TAPDU
+
+The StatusReport-TAPDU comprises the following elements:
+
+| StatusReport-TAPDU                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |  |
+|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--|
+| <pre> StatusReport-TAPDU ::= SEQUENCE {   [0] SEQUENCE {     statusReport [0] StatusReportTAPDUId     [1] SEQUENCE {       correlationInfo      CorrelationInfoElementId,       call-id              CallIdentification }},   [1] SET {     [0] SEQUENCE {       timeOfReport          TimeOfReportElementId,       report-time           DateandTime},     [1] SEQUENCE {       reportedMessageId     ReportedMessageIdElementId,       reported-message-id   MessageTypeValue },     [2] SET OF SEQUENCE {       [0] SEQUENCE {         actualRecipient      ActualRecipientElementId,         actual-recipient-name ORName },       [1] SEQUENCE {         messageStatus [1] MessageStatusElementId,         status         StatusValue },       [2] SET {         -- In case of DN, this set         -- of element shall be present.         [0] SEQUENCE {           timeOfDelivery      TimeOfDeliveryElementId,           delivery-time       DateandTime },         [1] SEQUENCE {           typeOfUA            TypeOfUAElementId,           type-of-ua         TypeOfUA DEFAULT public } OPTIONAL } OPTIONAL     },     [3] SEQUENCE {       -- In case of DN, this set       -- of element shall be present.       nonDeliveryReason      NonDeliveryReasonElementId,       SET {         reason-code [0] ReasonCodeValue,         diagnostic-code [1] DiagnosticCodeValue } OPTIONAL }} OPTIONAL }}, </pre> |  |
+
+## 10.2 Operation of the TLMAU
+
+The section describes how the TLMAU will provide the TLM abstract service. The TLM abstract operations have been defined by abstract operations, sometimes with associated results or errors. These abstract operations, results and errors are realized via the exchange of TAPDUs between the TLM terminal and the TLMAU.
+
+The realization of the abstract operations for the import and export ports linking the TLMAU and the MTS, is beyond the scope of this Recommendation. For the purpose of this section import and export operations will be considered to be similar to submission and delivery port operations.
+
+### 10.2.1 MessageSend
+
+The MessageSend operation will be provided by the TLMAU via the Send-, SendAck- and Exception-TAPDUs:
+
+Upon receipt of Send-TAPDU by the TLMAU, the TLMAU will take the following actions:
+
+- 1) The TLMAU will invoke the MTAS import abstract operation MessageSubmission with the following argument values:
+
+#### Source of MTAS MessageSubmission arguments
+
+| MessageSubmission argument         | CorrespondingSend-TAPDU component |                                       | Operation                                    |
+|------------------------------------|-----------------------------------|---------------------------------------|----------------------------------------------|
+|                                    | Element name                      | Value name                            |                                              |
+| originator-name                    | –                                 | –                                     | Authenticate User (Note 1)                   |
+| original-encoded-information-types | –                                 | –                                     | set by TLMAU to EITs of submitted IPM's body |
+| content-type                       | –                                 | –                                     | set by TLMAU to "IPMS"                       |
+| content-identifier                 | –                                 | –                                     | Local matter                                 |
+| content-correlator                 | –                                 | –                                     | Local matter                                 |
+| recipient-name                     | to, cc, bcc                       | primary-, copy-, blind-copy-recipient | constructed by TLMAU                         |
+
+*Note 1* – Authenticate User is constructed from TID obtained from CSS terminal ID.
+
+*Note 2* – The IPM submitted as the content is constructed by the TLMAU. Send-TAPDU components representing IPMS elements are mapped onto the corresponding IPMS application protocol data unit (APDU) elements.
+
+*Note 3* – A multi-document messages will be submitted as an IP message with a multi-part body, each body part corresponding to a submitted document.
+
+*Note 4* – When this-IPM of IPMS element is omitted, the TLMAU shall construct this component which consists of the following components: originator name, Date and Time and, if necessary, a sequence number.
+
+Other message submission arguments have a corresponding Send-TAPDU component. If this component is omitted, the default value applies.
+
+- 2) If the MessageSubmission operation results in an error or if an error is detected in the Send-TAPDU, the TLMAU will return an Exception-TAPDU to the originating TLM terminal.
+- 3) The TLMAU will, when required, return a SendAck-TAPDU to the originating TLM terminal following the successful completion of the MessageSubmission operation. The values of the SendAck-TAPDU will be set as follows:
+
+#### Source of SendAck-TAPDU components
+
+| SendAck-TAPDU component |                   | Source                                                                   |
+|-------------------------|-------------------|--------------------------------------------------------------------------|
+| Element name            | Value name        |                                                                          |
+| correlationInfo         | call-id           | CallIdentification that identifies previous Send-TAPDU being reported on |
+| submissionId            | submission-msg-id | MTS message-submission-identifier                                        |
+| submissionTime          | submission-time   | MTS message-submission-time                                              |
+
+- 4) The TLMAU will maintain a one-to-one correlation between MTS message-submission-identifiers and correlation information values to facilitate status query.
+
+### 10.2.2 *MessageProbe*
+
+The MessageProbe operation is provided by the TLMAU via the Probe-, ProbeAck- and Exception-TAPDUs.
+
+Upon receipt of the Probe-TAPDU by the TLMAU, the TLMAU will take the following actions:
+
+- 1) The TLMAU will invoke the MTAS import abstract operation ProbeSubmission with the following argument values:  
+Source of MTAS ProbeSubmission arguments.  
+See § 10.2.1 - MessageSubmission arguments.
+- 2) If the Probe operation results in an error or if an error is detected in the Probe-TAPDU, the TLMAN will return an Exception-TAPDU to the originator.
+- 3) The TLMAU will, when required, return a ProbeAck-TAPDU to the originator, following the successful completion of the probe operation. The values of the ProbeAck-TAPDU will be set as follows:
+
+#### Source of ProbeAck-TAPDU components
+
+| ProbeAck-TAPDU component |                 | Source                                                                    |
+|--------------------------|-----------------|---------------------------------------------------------------------------|
+| Element name             | Value name      |                                                                           |
+| correlationInfo          | call-id         | CallIdentification that identifies previous Probe-TAPDU being reported on |
+| probeId                  | probe-msg-id    | MTS probe-submission-identifier                                           |
+| submissionTime           | submission-time | MTS probe-submission-time                                                 |
+
+### 10.2.3 *ExplicitReceive*
+
+The *ExplicitReceive* operation is provided by the TLMAU via the *ExplicitRN*-, *ExplicitRNAck*- and *Exception-TAPDU*s.
+
+Upon receipt of the *ExplicitRN-TAPDU* the TLMAU will take the following actions:
+
+- 1) The TLMAU will invoke the MTAS import abstract operation *MessageSubmission* with the following argument values:
+
+#### Source of MTAS *MessageSubmission* components
+
+| MessageSubmission argument         | Corresponding<br>ExplicitRN-TAPDU component |                | Operation                                   |
+|------------------------------------|---------------------------------------------|----------------|---------------------------------------------|
+|                                    | Element name                                | Value name     |                                             |
+| originator-name                    | –                                           | –              | authenticate user                           |
+| original-encoded-information-types | –                                           | –              | set by TLMAU to “unspecified”               |
+| content-type                       | –                                           | –              | set by TLMAU to “IPMS”                      |
+| content-identifier                 | –                                           | –              | Local matter                                |
+| priority                           | priority                                    | priority-ind   |                                             |
+| per-message-indicators             |                                             |                |                                             |
+| disclose-recipients                | –                                           | –              | set to “disclosure-of recipient-prohibited” |
+| conversion-prohibited              | –                                           | –              | set to “conversion-prohibited”              |
+| alternate-recipient-allowed        | –                                           | –              | set to “alternate-recipient-prohibited”     |
+| content-return-request             | –                                           | –              | set to “content-return-not-requested”       |
+| recipient-name                     | recipients                                  | recipient-name |                                             |
+| originator-report-request          | –                                           | –              | set by TLMAU to “no report”                 |
+| content                            | –                                           | –              | identified as IPN                           |
+
+*Note 1* – The IPN submitted as the content is constructed by the TLMAU. *ExplicitRN-TAPDU* elements representing IPMS elements are mapped onto the corresponding IPMS APDU elements.
+
+*Note 2* – If receipt-time is omitted, the TLMAU extracts the Receipt time from the CSS of the session in which this TAPDU was transferred to. This time may differ from the time of actual receipt of IPM.
+
+*Note 3* – Set acknowledgment-mode of IPN to "manual".
+
+- 2) If the Message-Submission operation results in an error, or if an error is detected in the ExplicitRN-TAPDU, the TLMAU will return an Exception-TAPDU to the originator.
+- 3) The TLMAU will, when required, return a ExplicitRNAck-TAPDU to the originator, following the succesful completion of the MessageSubmission operation. The values of the ExplicitRNAck-TAPDU will be set as follows:
+
+#### Source of ExplicitRNAck-TAPDU components
+
+| ExplicitRNAck-TAPDU component |                   | Source                                                                         |
+|-------------------------------|-------------------|--------------------------------------------------------------------------------|
+| Element name                  | Value name        |                                                                                |
+| correlationInfo               | call-id           | CallIdentification that identifies previous ExplicitRN-TAPDU being reported on |
+| submissionId                  | submission-msg-id | MTS message-submission-identifier                                              |
+| submissionTime                | submission-time   | MTS message-submission-time                                                    |
+
+### 10.2.4 *MessageCancel*
+
+The MessageCancel operation is provided by the TLMAU via the Cancel- and Exception-TAPDUs.
+
+Upon receipt of the Cancel-TAPDU by the TLMAU, the TLMAU will take the following actions:
+
+The TLMAU will invoke the MTAS abstract operation CancelDeferredDelivery with the following argument value:
+
+#### Source of CancelDeferredDelivery arguments
+
+| CancelDeferredDelivery argument | Corresponding Cancel-TAPDU component |                   | Operation |
+|---------------------------------|--------------------------------------|-------------------|-----------|
+|                                 | Element name                         | Value name        |           |
+| message-submission-identifier   | submissionId                         | submission-msg-id |           |
+
+If the CancelDeferredDelivery operation results in an error, or if an error is detected in the Cancel-TAPDU, the TLMAU will return an Exception-TAPDU to the originating TLM terminal.
+
+### 10.2.5 *MessageDeliver*
+
+The MessageDeliver operation is provided by the TLMAU via the Deliver-TAPDU.
+
+When the MTAS abstract operation MessageDelivery is invoked by the MTS with an IPM as the MTS message content, the TLMAU will take the following actions:
+
+- 1) The TLMAU will construct a Deliver-TAPDU for transmission to the destination TLM terminal with the following element values:
+
+#### Source of Deliver-TAPDU component
+
+| Deliver-TAPDU component |                         | Corresponding MessageDelivery argument | Operation                                                                                                      |
+|-------------------------|-------------------------|----------------------------------------|----------------------------------------------------------------------------------------------------------------|
+| Element name            | Value name              |                                        |                                                                                                                |
+| quantityOfDocs          | number-of-docs          | —                                      | when control Information is conveyed by a normal document, set number of associated documents in Deliver-TAPDU |
+| priority                | priority-ind            | priority                               |                                                                                                                |
+| originator              | originator-name         | originator-name                        |                                                                                                                |
+| thisRecipient           | this-recipient-name     | this-recipient-name                    |                                                                                                                |
+| intendedRecipient       | intended-recipient-name | originally-intended-recipient-name     |                                                                                                                |
+| otherRecipients         | other-recipient-name    | other-recipient-names                  |                                                                                                                |
+| submissionTime          | submission-time         | message-submission-time                |                                                                                                                |
+| timeOfDelivery          | delivery-time           | message-delivery-time                  |                                                                                                                |
+| deliveryId              | delivery-msg-id         | message-delivery-identifier            |                                                                                                                |
+| conversionIndication    | eIT                     | original-encoded-information-types     |                                                                                                                |
+| conversionIndication    | conversion-prohibited   | delivery-flags                         |                                                                                                                |
+| convertedInfoTypes      | eIT                     | converted-encoded-information-types    |                                                                                                                |
+
+*Note 1* – The IPM received by TLMAU is used to construct the Deliver-TAPDU, Deliver-TAPDU elements, representing MTS and IPMS elements of service, are constructed by the TLMAU from the MessageDeliver operation arguments and IPMS application protocol data unit (APDU) values as indicated above.
+
+*Note 2* – Multi-part body message will be sent to the destination TLM terminal by the TLMAU as a multi-document message, each document corresponding to an IP message body part.
+
+- 2) If the TLMAU is unable to deliver the constructed Deliver-TAPDU to the designation TLM terminal, then an IPN will be constructed for return to the IPMS originator. This IPN will be submitted according to § 10.2.6.
+- 3) The definition of the export port MessageDeliver abstract operation should include a result argument indicating successful delivery or non-delivery. The MTS would then return delivery notifications to the originators of messages routed through a TLMAU only after the result value was indicated.
+
+### 10.2.6 *ReceiptStatusNotice*
+
+The ReceiptStatusNotice operation is provided by the TLMAU via the ReceiptStatusNotice-TAPDU.
+
+When the MTAS abstract operation MessageDelivery is invoked by the MTS with an IPN as the IPMS content, the TLMAU will take the following actions:
+
+- 1) The TLMAU will construct a ReceiptStatusNotice-TAPDU for transmission to the destination TLM terminal with the following element values:
+
+#### Source of ReceiptStatusNotice-TAPDU components
+
+| ReceiptStatusNotice-TAPDU component |                       | Corresponding MessageDelivery and receiveRN/NRN argument | Operation                                                                                                                  |
+|-------------------------------------|-----------------------|----------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------|
+| Element name                        | Value name            |                                                          |                                                                                                                            |
+| quantityOfDocs                      | number-of-docs        | —                                                        | when control Information is conveyed by a normal document, set number of associated documents in ReceiptStatusNotice-TAPDU |
+| priority                            | priority-ind          | priority                                                 |                                                                                                                            |
+| deliveryId                          | delivery-id           | message-delivery-identifier                              |                                                                                                                            |
+| originator                          | originator-name       | originator-identifier                                    | if this element is omitted, this argument should be constructed from TID obtains from CSS                                  |
+| thisRecipient                       | this-recipient-name   | this-recipient-identifier                                |                                                                                                                            |
+| submissionTime                      | submission-time       | message-submission-time                                  |                                                                                                                            |
+| timeOfDelivery                      | delivery-time         | message-delivery-time                                    |                                                                                                                            |
+| conversionIndication                | eIT                   | original-encoded-information-types                       |                                                                                                                            |
+| conversionIndication                | conversion-prohibited | delivery-flags                                           |                                                                                                                            |
+| convertedInfoTypes                  | eIT                   | converted-encoded-information-types                      |                                                                                                                            |
+| notificationType                    | report-type           | choice                                                   |                                                                                                                            |
+| subjectIPM                          | subject-imps-id       | subject-ipm                                              |                                                                                                                            |
+| iPNOriginator                       | ipn-originating-user  | ipn-originator                                           |                                                                                                                            |
+| preferredRecipient                  | preferred-recipient   | ipm-preferred-recipient                                  |                                                                                                                            |
+| timeOfReceipt                       | receipt-time          | receipt-time                                             |                                                                                                                            |
+| typeOfReceipt                       | type-of-receipt       | acknowledgment-mode                                      |                                                                                                                            |
+| supplReceiptInfo                    | suppl-receipt-info    | suppl-receipt-info                                       |                                                                                                                            |
+| nonReceiptInfo                      | non-receipt-reason    | non-receipt-reason                                       |                                                                                                                            |
+| nonReceiptInfo                      | discard-reason        | discard-reason                                           |                                                                                                                            |
+| comment                             | comments              | auto-forward-comment                                     |                                                                                                                            |
+| messageReturnedInd                  | —                     | returned-ipm                                             |                                                                                                                            |
+
+*Note* – What is received by the TLMAU is used to construct the ReceiptStatusNotice-TAPDU. ReceiptStatusNotice-TAPDU elements representing MTS and IPMS elements of service, are constructed by the TLMAU from the MessageDeliver operation arguments and IPMS APDU values, as indicated above.
+
+### 10.2.7 *DeliveryStatusNotice*
+
+The DeliveryStatusNotice operations are provided by the TLMAU via the DeliveryStatusNotice-TAPDU.
+
+When the MTS abstract operation ReportDelivery is invoked by the MTS, the TLMAU will take the following actions:
+
+- 1) The TLMAU will construct a DeliveryStatusNotice-TAPDU for transmission to the destination TLM terminal with the following element values:
+
+#### Source of DeliveryStatusNotice-TAPDU components
+
+| DeliveryStatusNotice-TAPDU component |                         | Corresponding ReportDelivery argument | Operation                                                                                                                  |
+|--------------------------------------|-------------------------|---------------------------------------|----------------------------------------------------------------------------------------------------------------------------|
+| Element name                         | Value name              |                                       |                                                                                                                            |
+| quantityOfDocs                       | number-of-docs          | –                                     | when control Information is conveyed by a normal document, set number of associated documents in DeliverStatusNotice-TAPDU |
+| correlationInfo                      | call-id                 | –                                     | CallIdentification that identifies previous Send-TAPDU being reported on                                                   |
+| priority                             | priority-ind            | priority                              |                                                                                                                            |
+| SubmissionId                         | submission-id           | subject-identifier                    |                                                                                                                            |
+| probeId                              | submission-id           | subject-identifier                    |                                                                                                                            |
+| reportedRecipient                    | reported-recipient-name | actual-recipient-identifier           |                                                                                                                            |
+| notificationType                     | report-type             | report                                |                                                                                                                            |
+| intendedRecipient                    | intended-recipient-name | originally-intended-recipient         |                                                                                                                            |
+| convertedInfoType                    | eIT                     | converted-encoded-information-types   |                                                                                                                            |
+| timeOfDelivery                       | delivery-time           | message-delivery-time                 |                                                                                                                            |
+| typeOfUA                             | type-of-ua              | type-of-MTS-user                      |                                                                                                                            |
+| nonDeliveryReason                    | reason-code             | non-delivery-reason-code              |                                                                                                                            |
+| nonDeliveryReason                    | diagnostic-code         | non-delivery-diagnostic-code          |                                                                                                                            |
+| contentReturned                      |                         | returned-content                      |                                                                                                                            |
+
+- 2) When required, the TLMAU will accumulate notifications pertaining to a single Send-TAPDU and construct a single DeliveryStatusNotice-TAPDU from multiple ReportDelivery operations.
+
+### 10.2.8 *Register*
+
+The register operation is provided by the TLMAU via the register-, RegisterAck- and Exception-TAPDUs.
+
+Upon receipt of the Register-TAPDU, the TLMAU will take the following actions:
+
+- If a message delete mode was selected, the TLMAU will subsequently operate according to the new mode with respect to messages output from the DS of the TLM terminal originating the Register-TAPDU,
+
+- If an error recovery mode was selected, the TLMAU will subsequently handle error recovery according to the selected criteria for all transactions with the originator of the Register-TAPDU.
+- If a DS mode was selected, the TLMAU will subsequently either hold for retrieval, or auto output messages in the DS of the originator of the Register-TAPDU according to the DS mode selected in this TAPDU.
+- If the auto discard mode was enabled by the Register-TAPDU, then the TLMAU will commence automatic deletion of messages in the DS belonging to the originator of the Register-TAPDU when they are obsoleted by subsequent received IPM's.
+- If the auto acknowledgement function was enabled by the Register-TAPDU, then the TLMAU will automatically format and submit receipt notifications for subsequent IP messages directed to the originator of the Register-TAPDU. These notifications will be submitted, either following successful delivery of the IP message to the TLM terminal, or upon deposit of the IP message in the TLM terminal's DS.
+- If an error is detected with the Register-TAPDU, the TLMAU will return an Exception-TAPDU to the originator.
+
+### 10.2.9 *DSList*
+
+The DSList operation is implemented by the TLMAU as an internal operation and does not involve the MTS. The DS list operation is provided via the DSQuery-, DSReport- and Exception-TAPDUs as follows:
+
+Upon receipt of the DSQuery-TAPDU by the TLMAU, the TLMAU will take the following actions:
+
+- The TLMAU will prepare a DSReport-TAPDU for return to the originator. If there are no messages in DS, the DSReport-TAPDU will indicate this.
+- If an error is detected with the DSQuery-TAPDU, the TLMAU will return an Exception-TAPDU to the originator.
+
+### 10.2.10 *DSDelete*
+
+The DSDelete operation is implemented by the TLMAU as an internal operation and does not involve the MTS. The DS Delete operation is provided via the DSDelete- and Exception-TAPDUs as follows:
+
+- The TLMAU will delete the indicated message(s) from the DS.
+- If an error is detected with the DSDelete-TAPDU or the message indicated is not available for deletion, the TLMAU will return an Exception-TAPDU to the originator.
+
+### 10.2.11 *DSFetch*
+
+The DSFetch operation is implemented by the TLMAU as an internal operation and does not involve the MTS. The DSFetch operation is provided via the OutputRequest-, OutputMessage- and Exception-TAPDUs as follows:
+
+Upon receipt of the OutputRequest-TAPDU by the TLMAU, the TLMAU will take the following actions:
+
+- For each message indicated in the OutputRequest-TAPDU and found in the DS, the TLMAU will prepare and return an OutputMessage-TAPDU.
+- If the delete-after-output function was indicated in the OutputMessage-TAPDU the TLMAU will delete the indicated message(s) from the DS after output.
+- If the "auto delete" message delete mode is subscribed to then the TLMAU will delete the indicated message(s) from the DS after output regardless of whether the delete-after-output function was selected in the OutputRequest-TAPDU.
+- If an error is detected with the OutputRequest-TAPDU or the message(s) indicated were not available for output, the TLMAU will return an Exception-TAPDU to the originator. If some of a list of indicated messages are available in DS then the TLMAU will output those available, and then return an Exception-TAPDU for those not available or incorrectly indicated.
+- If the "auto output" DS mode is subscribed to then the output and associated deletion functions will be executed when the user subscribed conditions are met.
+
+### 10.2.12 *OutputMessage*
+
+The delivery-time in this TAPDU is the time when the DS received the message.
+
+### 10.2.13 *MessageStatus*
+
+The MessageStatus operation is implemented by the TLMAU as an internal operation and does not involve the MTS. This operation is applicable only when the TLMAU accumulates notifications for previously submitted multi-address messages. The operations provided by the TLMAU via the StatusQuery-, StatusReport-and Exception-TAPDUs.
+
+Upon receipt of the StatusQuery-TAPDU by the TLMAU, the TLMAU will take the following actions:
+
+- The TLMAU will construct a StatusReport-TAPDU from accumulated notifications pertaining to the message identified in the StatusRequest-TAPDU.
+- The TLMAU will not allow StatusQuery operation for ReceiptStatusNotice.
+- If an error is detected with the StatusReport-TAPDU or there is no record of the message indicated, the TLMAU will return an Exception-TAPDU to the originator.
+
+# 11 **Formats and encoding of TAPDU**
+
+## 11.1 *Principles*
+
+Elements of a telematic access protocol data unit (TAPDU) shall be coded using human-readable graphic characters of Recommendation T.61 coding scheme. Other coding rules such as machine-readable coding are for further study.
+
+## 11.2 *Structure of TAPDU*
+
+- 1) A TAPDU is composed of one or more documents. The first one contains control information optionally followed by one or more documents with text (message body information). Within one session one or more TAPDU may be conveyed.
+- 2) Control information is conveyed in either a control document or a normal document.
+- 3) The control information is subdivided into a TAPDUs and elements each containing a number field and/or name field, and optionally one or more element value fields. An element number field, which is language independent, and the element name, which is language dependent, uniquely identify an element. In case of international access, the element number field must always be present.
+- 4) The value fields of an element may contain the same TAPDU information types or different TAPDU information types. The element value Fields (called components) are categorized as follows:
+  - components with pre-defined values, i.e. components with a specific, enumerable set of known, unique values (predefined value);
+  - components with a wide range of values which are not pre-defined (general value).
+- 5) There are two different types of component fields:
+  - primitive component;
+  - constructor component.
+- 6) Each primitive component contains only one parameter. Each constructor component contains more than one parameter.
+- 7) A parameter contains a parameter value, optionally preceded by a Parameter-Id. which identifies the parameters.
+- 8) The formal description of the structure of a TAPDU is shown in Table 3/T.330.
+- 9) A line may contain an Element-Id field and component fields, or the first component field of the element starts on a new line.
+- 10) If the number of characters of the component exceeds the remaining number of characters on this line, the component must be divided into two or more lines by "NL" function. However, it is not allowed to divide the component within a parameter.
+
+TABLE 3/T.330  
+**The structure of TAPDUs**
+
+```
+
+TAPDU ::= SEQUENCE {
+    ControlInfo,
+    SEQUENCE OF MessageBodyInfo OPTIONAL },
+ControlInfo ::= SEQUENCE {
+    TAPDUId,
+    Elements OPTIONAL }
+TAPDUId ::= SEQUENCE {
+    TAPDUNumber OPTIONAL,
+    TAPDUName OPTIONAL }
+
+    -- One of these must be present.
+Elements ::= SEQUENCE {
+    ElementId,
+    ElementValues }
+ElementId ::= SEQUENCE {
+    ElementNumber OPTIONAL,
+    ElementName OPTIONAL }
+
+    -- One of these must be present.
+ElementValues ::= SET OF Component
+    -- See Note
+Component ::= CHOICE {
+    PrimitiveComponent,
+    ConstructorComponent }
+
+PrimitiveComponent ::= Parameter
+ConstructorComponent ::= SET OF Parameter
+Parameter ::= SEQUENCE {
+    ParameterId OPTIONAL,
+    ParameterValue }
+
+```
+
+*Note* – Order of components as prescribed by the TAPDU descriptions in § 10.
+
+## 11.3 Coding rule
+
+### 11.3.1 TAPDU ID
+
+- 1) The TAPDU number assigned to TAPDU shall consist of two parts separated by a "period" (.). The first part identifies the application, for example, "3" is assigned to this application. The second part identifies the procedures specified in the application.
+- 2) Where national requirements dictate the use of non-standardized TAPDU numbers. Administrations may choose any values in the range 1000-1999 for the first part of non-standardized application identifiers.
+- 3) Other rules applied to TAPDU number and name are same as those of the element number and name, described below.
+
+### 11.3.2 Element ID
+
+- 1) The element number shall be sequentially assigned a different number.
+- 2) An element number is always closed by the character "colon" (:).
+- 3) There shall be no restriction of the number of digits for element numbers and any leading zeros are ignored.
+- 4) Where national requirements dictate the use of non-standardized element numbers Administrations may choose any values in the range 1000-1999 for non-standardized elements.
+
+- 5) The element number and the element name shall be separated by the character "space".
+- 6) An element name shall be represented by a text string, that is a sequence of graphic characters. Capital and small characters have the same effect.
+- 7) An element name is always closed by the character "colon" (:).
+
+### 11.3.3 *Element value fields*
+
+For unregistered TLM-users with international access, the pre-defined values as defined in the following tables have to be applied. For all other cases, these values can be replaced by nationally defined values.
+
+### 11.3.4 *Separators and common rules*
+
+- 1) TAPDU-Ids and elements shall be preceded by the following delimiters:
+  - "CR LF" sequence, or
+  - "CR LF BS +" sequence.
+- 2) The Element-Id and the First component shall be separated by the character "space" or "New Line" functions ("NL" = "CR LF" or "LF CR").
+- 3) Components shall be separated by "comma" (",") and optionally "NL".
+- 4) When components with pre-defined and not pre-defined values are contained in an element, they shall be separated by a "NL" and the line with the pre-defined values should start with the character "=".
+- 5) Parameters within one component field shall be separated by the character "slash" ("/" ) or "semi-colon" (";"). "CR LF" within a parameter is not allowed, except if the parameter is longer than 1 line.
+- 6) The actual value of a parameter value is encoded by a sequence of graphic characters. Capital and small characters have the same effect.
+- 7) If some pre-defined values are absent but required, then their default value shall apply.
+- 8) The element ID and the first element value field shall be separated by the character "space" or the "NL" function.
+- 9) Contiguous "NL" and "LF" are considered as one "NL".
+- 10) Contiguous embedded spaces are considered as one space. Leading spaces in a line are ignored.
+- 11) The character sequence "Space //" indicates that the following of the line shall be considered as a comment.
+
+## 11.4 *Format of TAPDU*
+
+The format of each TAPDU according to the above coding rules is shown in Annex C of this Recommendation.
+
+## 11.5 *Reference between TAPDU components and its coding format*
+
+This section provides the tables necessary for the encoding of TAPDU components.
+
+### 11.5.1 *TAPDUId and elementId* (see Table 4/T.330)
+
+Table 4/T.330 comprises four columns:
+
+- 1) The first column contains the TAPDUId or Element-Id name as used in the ASN.1 description of § 10.
+- 2) The second column contains the type of this element:
+  - a) primitive: the element contains only one elementValue field;
+  - b) constructor: the element may contain more than one elementValue field.
+- 3) The third column contains the actual coding format of the TAPDUId or element-Id.
+- 4) The last column contains remarks.
+
+### 11.5.2 *ElementValues* (see Table 5/T.330)
+
+Table 5/T.330 comprises five columns:
+
+- 1) The first column contains the ElementValue name (component name) as used in the ASN.1 description of § 10.
+- 2) The second column contains the type of ElementValue field:
+  - a) primitive: the component contains only one parameter.
+  - b) constructor: the component may contain more than one parameter.
+
+- 3) The third column contains the type of the value:
+  - a) predefined;
+  - b) general, as defined in this section.
+- 4) The fourth column contains the actual coding format, or, in case of general value, a reference name which points to the actual coding format in Table 6/T.330.
+- 5) The last column contains remarks.
+
+### 11.5.3 *General values* (see Table 6/T.330)
+
+Table 6/T.330 comprises five columns:
+
+- 1) The first column contains the reference name (general value name) used in Table 5/T.330.
+- 2) The second column contains the name of the parameter.
+- 3) The third column contains the code of the value.
+- 4) The fourth column contains the keyword and format of this parameter,
+- 5) The last column contains remarks.
+
+TABLE 4/T.330
+
+#### Format encoding of TAPDU and ElementId
+
+| TAPDUId and ElementId name | Type        | T.61 Character coding format               | Remarks           |
+|----------------------------|-------------|--------------------------------------------|-------------------|
+| authorizing                | Constructor | <u>21</u> : □ AUTHORIZING:                 |                   |
+| autoFWDComment             | Primitive   | 79 : □ AUTO-FWD-COMMENT:                   |                   |
+| autoFWDHeading             |             | 78 : □ AUTO-FWD-HEADING:                   | For further study |
+| autoFWDIPMs                | Primitive   | 76 : □ AUTO-FWD-IPMS:                      |                   |
+| autoFWDRecipients          | Constructor | 77 : □ AUTO-FWD-RECIPIENTS:                |                   |
+| autoOutput                 | Constructor | <u>60</u> : □ AUTO-OUTPUT:                 |                   |
+| bcc                        | Constructor | <u>24</u> : □ BCC:                         |                   |
+| bodyType                   | Constructor | <u>31</u> : □ BODY-TYPE:                   |                   |
+| cancel                     | –           | <u>3.13</u> : □ CANCEL:                    |                   |
+| cc                         | Constructor | <u>23</u> : □ CC:                          |                   |
+| comment                    | Primitive   | <u>50</u> : □ COMMENT:                     |                   |
+| contentIndicator           | Constructor | <u>18</u> : □ CONTENT-INDICATOR:           |                   |
+| contentInfo                | Primitive   | <u>17</u> : □ CONTENT-INFO:                |                   |
+| contentReturned            | –           | <u>72</u> : □ CONTENT-RETURNED-INDICATION: |                   |
+| conversion                 | Primitive   | <u>16</u> : □ CONVERSION:                  |                   |
+| conversionIndication       | Constructor | <u>42</u> : □ CONVERSION-INDICATION:       |                   |
+| convertedInfoTypes         | Primitive   | <u>44</u> : □ CONVERTED-INFORMATION-TYPES: |                   |
+| correlationInfo            | Primitive   | <u>1</u> : □ CORRELATION-INFORMATION:      |                   |
+| deleteAfterOutput          | Primitive   | <u>80</u> : □ DELETE-AFTER-OUTPUT:         |                   |
+| deliver                    | –           | <u>3.3</u> : □ DELIVER:                    |                   |
+| deliveryId                 | Primitive   | <u>35</u> : □ DELIVERY-ID:                 |                   |
+| deliveryStatusNotice       | –           | <u>3.4</u> : □ DELIVERY-STATUS-NOTICE:     |                   |
+| dsMode                     | Primitive   | <u>58</u> : □ DS-MODE:                     |                   |
+| dsQuery                    | –           | <u>3.7</u> : □ DS-QUERY:                   |                   |
+| dsReport                   | –           | <u>3.8</u> : □ DS-REPORT:                  |                   |
+| errors                     | Primitive   | <u>9</u> : □ ERRORS:                       |                   |
+| exception                  | –           | <u>3.12</u> : □ EXCEPTION:                 |                   |
+| expiredDiscard             | Primitive   | <u>73</u> : □ EXPIRED-DISCARD:             |                   |
+| explicitRN                 | –           | <u>3.6</u> : □ EXPLICIT-RN:                |                   |
+| explicitRNAck              | –           | <u>3.16</u> : □ EXPLICIT-RN-ACK:           |                   |
+| forwardedInfo              | Constructor | <u>32</u> : □ FORWARDED-INFO:              |                   |
+| from                       | Primitive   | <u>20</u> : □ FROM:                        |                   |
+
+TABLE 4/T.330 (cont.)
+
+| TAPDUId and ElementId name | Type        | T.61 Character coding format                                      | Remarks                    |
+|----------------------------|-------------|-------------------------------------------------------------------|----------------------------|
+| orgIntendedRecipient       | Primitive   | <u>40</u> : <input type="checkbox"/> INTENDED-RECIPIENT:          |                            |
+| iPNOriginator              | Primitive   | <u>69</u> : <input type="checkbox"/> IPN-ORIGINATOR:              |                            |
+| language                   | Primitive   | <u>53</u> : <input type="checkbox"/> LANGUAGE:                    |                            |
+| latestDelivery             | Primitive   | <u>34</u> : <input type="checkbox"/> LATEST-DELIVERY:             |                            |
+| messageDelete              | –           | <u>3.18</u> : <input type="checkbox"/> MESSAGE-DELETE:            |                            |
+| messageDeleteMode          | Primitive   | <u>81</u> : <input type="checkbox"/> MESSAGE-DELETE-MODE:         |                            |
+| messageLength              | Primitive   | <u>37</u> : <input type="checkbox"/> MESSAGE-LENGTH:              |                            |
+| messageReturnedInd         | –           | <u>51</u> : <input type="checkbox"/> MESSAGE-RETURNED-INDICATION: |                            |
+| messageSelector            | Primitive   | <u>82</u> : <input type="checkbox"/> MESSAGE-SELECTOR:            |                            |
+| messageStatus              | Primitive   | <u>83</u> : <input type="checkbox"/> MESSAGE-STATUS:              |                            |
+| messageType                | Primitive   | <u>52</u> : <input type="checkbox"/> MESSAGE-TYPE:                |                            |
+| msgIncomplete              | –           | <u>67</u> : <input type="checkbox"/> MSG-INCOMPLETE:              | This element has not value |
+| nonDeliveryReason          | Primitive   | <u>46</u> : <input type="checkbox"/> NON-DELIVERY-REASON:         |                            |
+| nonReceiptInfo             | Primitive   | <u>49</u> : <input type="checkbox"/> NON-RECEIPT-INFO:            |                            |
+|                            |             | <u>43</u> : <input type="checkbox"/> NOTIFICATION-TYPE:           |                            |
+| obsoletedDiscard           | Primitive   | <u>74</u> : <input type="checkbox"/> OBSOLETED-DISCARD:           |                            |
+| obsoletedIPMs              | Constructor | <u>29</u> : <input type="checkbox"/> OBSOLETED:                   |                            |
+| otherRecipients            | Constructor | <u>41</u> : <input type="checkbox"/> OTHER-RECIPIENTS:            |                            |
+| outputMessage              | –           | <u>3.10</u> : <input type="checkbox"/> OUTPUT-MESSAGE:            |                            |
+| outputRequest              | –           | <u>3.9</u> : <input type="checkbox"/> OUTPUT-REQUEST:             |                            |
+| perMessageIndicators       | Constructor | <u>19</u> : <input type="checkbox"/> FLAGS:                       |                            |
+| preferredRecipient         | Primitive   | <u>70</u> : <input type="checkbox"/> PREFERRED-RECIPIENT:         |                            |
+| priority                   | Primitive   | <u>13</u> : <input type="checkbox"/> PRIORITY:                    |                            |
+| probe                      | –           | <u>3.2</u> : <input type="checkbox"/> PROBE:                      |                            |
+| probeAck                   | –           | <u>3.15</u> : <input type="checkbox"/> PROBE-ACK:                 |                            |
+| probeId                    | Primitive   | <u>66</u> : <input type="checkbox"/> PROBE-ID:                    |                            |
+| quantityOfDocs             | Primitive   | <u>62</u> : <input type="checkbox"/> QUANTITY-OF-DOCS:            |                            |
+| recipients                 | Constructor | <u>15</u> : <input type="checkbox"/> RECIPIENTS:                  |                            |
+| receiptStatusNotice        | –           | <u>3.5</u> : <input type="checkbox"/> RECEIPT-STATUS-NOTICE:      |                            |
+| redirectedFrom             | Constructor | <u>54</u> : <input type="checkbox"/> REDIRECTED-FROM:             |                            |
+| register                   | –           | <u>3.11</u> : <input type="checkbox"/> REGISTER:                  |                            |
+| registerAck                | –           | <u>3.17</u> : <input type="checkbox"/> REGISTER-ACK:              |                            |
+
+TABLE 4/T.330 (end)
+
+| TAPDUId and ElementId name | Type        | T.61 Character coding format             | Remarks |
+|----------------------------|-------------|------------------------------------------|---------|
+| related IPMs               | Constructor | <u>28</u> : □ RELATED-IPMS:              |         |
+| repliedToIPM               | Primitive   | <u>30</u> : □ REPLIED-TO-IPM:            |         |
+| reply                      | Constructor | <u>25</u> : □ REPLY:                     |         |
+| reportedMessageId          | Primitive   | <u>75</u> : □ REPORTED-MESSAGE-ID:       |         |
+| reportedRecipient          | Primitive   | <u>3</u> : □ REPORTED-RECIPIENT:         |         |
+| retrievalId                | Primitive   | <u>38</u> : □ RETRIEVAL-ID:              |         |
+| returnAddress              | Primitive   | <u>36</u> : □ RETURN-ADDRESS:            |         |
+| send                       | –           | <u>3.1</u> : □ SEND:                     |         |
+| sendAck                    | –           | <u>3.14</u> : □ SEND-ACK:                |         |
+| statusQuery                | –           | <u>3.19</u> : □ STATUS-QUERY:            |         |
+| status Report              | –           | <u>3.20</u> : □ STATUS-REPORT:           |         |
+| subject                    | Primitive   | <u>26</u> : □ SUBJECT:                   |         |
+| subjectIPM                 | Primitive   | <u>71</u> : □ SUBJECT-IPM:               |         |
+| submissionId               | Primitive   | <u>65</u> : □ SUBMISSION-ID:             |         |
+| submissionTime             | Primitive   | <u>33</u> : □ SUBMISSION-TIME:           |         |
+| supplInfo                  | Primitive   | <u>68</u> : □ SUPPLEMENTARY-INFORMATION: |         |
+| supplReceiptInfo           | Primitive   | <u>68</u> : □ SUPPLEMENTARY-INFORMATION: |         |
+| thisIPM                    | Primitive   | <u>27</u> : □ THIS-IPM:                  |         |
+| thisRecipient              | Primitive   | <u>39</u> : □ THIS-RECIPIENT:            |         |
+| timeOfDelivery             | Primitive   | <u>4</u> : □ TIME-OF-DELIVERY:           |         |
+| timeOfReceipt              | Primitive   | <u>47</u> : □ TIME-OF-RECEIPT:           |         |
+| timeOfReport               | Primitive   | <u>84</u> : □ TIME-OF-REPORT:            |         |
+| tLMAUOperation             | Constructor | <u>59</u> : □ TLMAU-OPERATION:           |         |
+| to                         | Constructor | <u>22</u> : □ TO:                        |         |
+| typeOfReceipt              | Primitive   | <u>48</u> : □ TYPE-OF-RECEIPT:           |         |
+| typeOfUA                   | Primitive   | <u>45</u> : □ TYPE-OF-UA:                |         |
+
+#### *Conventions:*
+
+- 1) Primitive: element contains only one element value field.
+- 2) Constructor: element may contain more than one element value field.
+- 3) abcde: underlined characters, i.e. "abc" are mandatory in case of international access (see § 11.2).
+- 4) □: space character.
+
+TABLE 5/T330  
+Format encoding of elements values
+
+| Element value name            | Type of element value field | Type of value | T.61 character coding format                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  | Remarks |
+|-------------------------------|-----------------------------|---------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------|
+| alternate-recipient-allowed   | Primitive                   | Predefined    | <u>Allowed</u>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |         |
+| authorizing                   | Constructor                 | –             | <u>21:☐ AUTHORIZING:</u>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |         |
+| authorizing-user              | Constructor                 | General       | <i>OR Descriptor</i>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |         |
+| auto-acknowledgment           | Primitive                   | Predefined    | <u>Auto-Receipt</u> , <u>Manual-Receipt</u> (default)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |         |
+| auto-forwarded                | Primitive                   | Predefined    | <u>Auto-forwarded</u> , <u>Not-Auto-forwarded</u> (default)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |         |
+| auto-fwd-Comment              | Primitive                   | General       | <i>any Text</i>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |         |
+| auto-fwd-ipms                 | Primitive                   | Predefined    | <u>Auto-forwarded</u> , <u>Not-Auto-forwarded</u> (default)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |         |
+| auto-fwd-recipient-name       | Constructor                 | General       | <i>OR Name</i>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |         |
+| blind-copy-recipient          | Constructor                 | General       | <i>OR Descriptor</i>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |         |
+| body-part                     | Primitive                   | Predefined    | <u>IA5Text</u> , <u>TLX</u> , <u>Voice</u> , <u>G3Fax</u> , <u>G4Fax-Class1</u> , <u>TTX</u> , <u>Videotex</u> , <u>Message</u> , <u>Mixed-Mode</u> , <u>Encrypted</u>                                                                                                                                                                                                                                                                                                                                                                                                        |         |
+| call-id                       | Primitive                   | General       | <i>Call Identification</i>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |         |
+| comments                      | Primitive                   | General       | <i>Comments</i>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |         |
+| content-return-request        | Primitive                   | Predefined    | <u>Content-Return-Request</u>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |         |
+| conversion-info               |                             |               | <u>NO</u> , <u>Yes</u> ; <u>WLOSS</u>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |         |
+| copy-recipient                | Constructor                 | General       | <i>OR Descriptor</i>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |         |
+| deferred-delivery-time        | Primitive                   | General       | <i>Date and Time</i>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |         |
+| delete-after-output           | Primitive                   | Predefined    | <u>Keep</u> , <u>Delete</u>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |         |
+| delivery-msg-id               | Primitive                   | General       | <i>Message Identifier</i>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |         |
+|                               | Primitive                   | General       | <i>Date and Time</i>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |         |
+| diagnostic-code <sup>a)</sup> | Primitive                   | Predefined    | <u>Unrecognized-OR-Name</u> , <u>Ambiguous-OR-Name</u> , <u>MTS-Congestion</u> , <u>Loop-Detected</u> , <u>Recipient-Unavailable</u> , <u>Maximum-Time-Expired</u> , <u>Content-Too-Long</u> , <u>Conversion-Impractical</u> , <u>Encoded-Information-Type-Unsupported</u> , <u>Conversion-Prohibited</u> , <u>Invalid-Arguments</u> , <u>Implicit-Conversion-Not-Subscribed</u> , <u>Content-Syntax-Error</u> , <u>Pragmatic-Constraint-Violation</u> , <u>Protocol-Violation</u> , <u>Content-Not-Supported</u> , <u>Too-Many-Recipient</u> , <u>No-Bilateral-Agreement</u> |         |
+
+TABLE 5/T.330 (cont.)
+
+| Element value name      | Type of element value field | Type of value | T.61 character coding format                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   | Remarks                                                                          |
+|-------------------------|-----------------------------|---------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------|
+| discard-ipm             | Primitive                   | Predefined    | <u>Discard</u> (default), <u>Not-Discard</u>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |                                                                                  |
+| discard-reason          | Primitive                   | Predefined    | <u>IPM-Expired</u> , <u>IPM-Obsoleted</u> , <u>User-Subscription-Terminated</u>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |                                                                                  |
+| disclose-recipients     | Primitive                   | Predefined    | <u>No-Disclosure</u>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |                                                                                  |
+| dsMode                  | Primitive                   | –             | 58: <input type="checkbox"/> DS-MODE:                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |                                                                                  |
+| ds-mode                 | Primitive                   | Predefined    | <u>Auto-Output</u> , <u>Retrieval</u>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |                                                                                  |
+| eIT                     | Primitive                   | Predefined    | <u>IA5Text</u> , <u>TLX</u> , <u>Voice</u> , <u>G3Fax</u> , <u>G4Fax-Class1</u> , <u>TTX</u> , <u>Videotex</u> , <u>Undefined</u> , <u>Mixed-Mode</u>                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |                                                                                  |
+| error-cause             | Primitive                   | Predefined    | <u>IPMS-Element-of-Service-Not-Subscribed</u> ,* <u>MTS-Element-of-Service-Not-Subscribed</u> ,* <u>Name-Malformed</u> ,* <u>IPM-Not-Submitted</u> , <u>IPM-Transferred</u> , <u>IPM-Delivered</u> , <u>Element-of-Service-Not-Subscribed</u> ,* <u>Message-Delivered</u> , <u>Message-Transferred</u> , <u>Originator-Invalid</u> ,* <u>Query-Identifier-Invalid</u> ,* <u>Recipient-Improperly-Specified</u> ,* <u>Submission-Identifier-Invalid</u> ,* <u>NO-Message-in-DS</u> , <u>DS-Not-Supported</u> , <u>DS-Not-Subscribed</u> , <u>Retrieval-Identifier-Invalid</u> ,* <u>Parameter-Invalid</u> ,* <u>Not-Changed</u> | * optionally followed by the name, service, parameter, etc. concerned in “ ... ” |
+| error-recovery-mode     | Primitive                   | Predefined    | <u>Recovery-1</u> , <u>Recovery-2</u> , <u>Recovery-3</u>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |                                                                                  |
+| expiry-time             | Primitive                   | General       | <i>Date and Time</i>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |                                                                                  |
+| explicit-conversion     | Primitive                   | Predefined    | <u>TLX</u> , <u>IA5</u> , <u>G3</u> , <u>G4</u> , <u>VTX</u> , <u>TTX</u>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |                                                                                  |
+| forwarded-time          | Primitive                   | General       | <i>Date and Time</i>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |                                                                                  |
+| frequency               | Primitive                   | General       | <i>Frequency</i>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |                                                                                  |
+| importance              | Primitive                   | Predefined    | <u>Low</u> , <u>Normal</u> (default), <u>High</u>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |                                                                                  |
+| intended-recipient-name | Constructor                 | General       | <i>OR Name</i>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |                                                                                  |
+| ipn-originating-user    | Constructor                 | General       | <i>OR Descriptor</i>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |                                                                                  |
+| language-ind            | Primitive                   | Predefined    |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                | ffs                                                                              |
+| latest-delivery-time    | Primitive                   | General       | <i>Date and Time</i>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |                                                                                  |
+| message-delete-mode     | Primitive                   | Predefined    | <u>Auto-Delete</u> (default), <u>Manual-Delete</u>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |                                                                                  |
+| message-length          | Primitive                   | General       | <i>Message Length</i>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |                                                                                  |
+| messageType             | Primitive                   | –             | 52: <input type="checkbox"/> MESSAGE-TYPE:                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |                                                                                  |
+| non-receipt-reason      | Primitive                   | Predefined    | <u>IPM-DISCARD</u> , <u>IPM-Auto-forwarded</u>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |                                                                                  |
+| nrn-request             | Primitive                   | Predefined    | <u>NRN-Request</u>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |                                                                                  |
+| number-of-docs          | Primitive                   | General       | <i>Number Of Associated Documents</i>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |                                                                                  |
+
+TABLE 5/T.330 (cont.)
+
+| Element value name                       | Type of element value field | Type of value | T.61 character coding format                                                          | Remarks |
+|------------------------------------------|-----------------------------|---------------|---------------------------------------------------------------------------------------|---------|
+| obsoleted-ipm-id                         | Constructor                 | General       | <i>IPM Identifier</i>                                                                 |         |
+| originating-user                         | Constructor                 | General       | <i>OR Descriptor</i>                                                                  |         |
+| originator-name                          | Constructor                 | General       | <i>OR Name</i>                                                                        |         |
+| originator-requested-alternate-recipient | Constructor                 | General       | <i>OR Name</i>                                                                        |         |
+| other-recipient-name                     | Constructor                 | General       | <i>OR Name</i>                                                                        |         |
+| output-time                              | Primitive                   | General       | <i>Date and Time</i>                                                                  |         |
+| Physical-delivery-mode                   | Primitive                   | Predefined    | "PDM= "OM (default), EMS, SPEC, COL, TLXA, TTXA, PHA, BFAX                            |         |
+| Physical-delivery-report-request         | Primitive                   | Predefined    | "REP= "UND (default), PDS, MHS, PDMHS                                                 |         |
+| Physical-forwarding-address-request      | Primitive                   | Predefined    | PFAR                                                                                  |         |
+| Physical-forwarding-prohibited           | Primitive                   | Predefined    | PFP                                                                                   |         |
+| postal-address                           | Primitive                   | General       | <i>Or Name</i>                                                                        |         |
+| preferred-recipient                      | Constructor                 | General       | <i>OR Descriptor</i>                                                                  |         |
+| primary-recipient                        | Constructor                 | General       | <i>OR Descriptor</i>                                                                  |         |
+| priority-ind                             | Primitive                   | Predefined    | <u>Urgent</u> , <u>Non-Urgent</u> , <u>Normal</u> (default)                           |         |
+| probe-msg-id                             | Primitive                   | General       | <i>Message Identifier</i>                                                             |         |
+| reason-code                              | Primitive                   | Predefined    | <u>Transfer-Failure</u> , <u>Unable-To-Transfer</u> , <u>Conversion-Not-Performed</u> |         |
+| receipt-time                             | Primitive                   | General       | <i>Date and Time</i>                                                                  |         |
+| recipient-name                           | Constructor                 | General       | <i>OR Name</i>                                                                        |         |
+| recipient-number-for-advice              | Primitive                   | General       | "CALL= "Number                                                                        |         |
+| recipient-reassignment-prohibited        | Primitive                   | Predefined    | RRP                                                                                   |         |
+| redirected-from                          | Constructor                 | General       | <i>OR Name</i>                                                                        |         |
+| registered-mail-type                     | Primitive                   | Predefined    | NRM (default), RM; RMA                                                                |         |
+| related-ipm-id                           | Constructor                 | General       | <i>IPM Identifier</i>                                                                 |         |
+| replied-to-ipm-id                        | Constructor                 | General       | <i>IPM Identifier</i>                                                                 |         |
+| reply-recipient                          | Constructor                 | General       | <i>OR Descriptor</i>                                                                  |         |
+| reply-request                            | Primitive                   | Predefined    | <u>Reply</u> , <u>No-Reply</u> (default)                                              |         |
+| reply-time                               | Primitive                   | General       | <i>Date and Time</i>                                                                  |         |
+| reported-message-id                      | Primitive                   | General       | <i>Message Identifier</i>                                                             |         |
+
+TABLE 5/T.330 (end)
+
+| Element value name        | Type of element value field | Type of value | T.61 character coding format                                                | Remarks |
+|---------------------------|-----------------------------|---------------|-----------------------------------------------------------------------------|---------|
+| reported-recipient-name   | Constructor                 | General       | <i>OR Name</i>                                                              |         |
+| report-time               | Primitive                   | General       | <i>Date and Time</i>                                                        |         |
+| report-type               | Primitive                   | Predefined    | <u>Receipt</u> , <u>Non-Receipt</u> , <u>Delivery</u> , <u>Non-delivery</u> |         |
+| requested-delivery-method | Primitive                   | Predefined    | "RDL=" ANY (default), MAS, PD, TLX, TTX, G3, G4 IA5, VTX                    |         |
+| retrieval-id              | Primitive                   | General       | <i>Retrieval Identifier</i>                                                 |         |
+| return-request            | Primitive                   | Predefined    | <u>Return</u> -Request                                                      |         |
+| rn-request                | Primitive                   | Predefined    | <u>RN</u> -Request                                                          |         |
+| sensitivity               | Primitive                   | Predefined    | <u>Personal</u> , <u>Private</u> , <u>Company-Confidential</u>              |         |
+| status                    | Primitive                   | Predefined    | <u>In-Process</u> , <u>Delivered</u> , <u>Non-Delivered</u>                 |         |
+| subject-content           | Primitive                   | General       | <i>Subject</i>                                                              |         |
+| subject-ipm-id            | Primitive                   | General       | <i>Message Identifier</i>                                                   |         |
+| submission-msg-id         | Primitive                   | General       | <i>Message Identifier</i>                                                   |         |
+| submissionTime            | Primitive                   | –             | 33: □ SUBMISSION-TIME:                                                      |         |
+| suppl-Info                | Primitive                   | General       | <i>Supplementary Information</i>                                            |         |
+| suppl-receipt-Info        | Primitive                   | General       | <i>Supplementary Information</i>                                            |         |
+| terminal-type             | Primitive                   | Predefined    | "TTyp=" TLX, TTX, G3, G4, IA5, vtx                                          |         |
+| this-recipient-name       | Constructor                 | General       | <i>OR Name</i>                                                              |         |
+| this-ipm-id               | Constructor                 | General       | <i>IPM Identifier</i>                                                       |         |
+| type-of-receipt           | Primitive                   | Predefined    | <u>Manual</u> (default), <u>Automatic</u>                                   |         |
+| type-of-ua                | Primitive                   | Predefined    | <u>Private</u> , <u>Public</u> (default)                                    |         |
+| user-report-request       | Primitive                   | Predefined    | <u>No-Report</u> , <u>Non-Delivery-Report</u> , <u>Report</u>               |         |
+
+a) More diagnostic-codes can be found in Recommendation X.411 and should be translated into appropriate T.61 text.
+
+*Note* – The character strings in italics in the fourth column are the entry name of the General value list, Table 6/T.330.
+
+*Conventions:*
+
+- 1) Primitive: elementary or value contains only one component.
+- 2) Constructor: element or value contains more than one component.
+- 3) abcde: underlined characters, i.e. "abc" are mandatory.
+
+TABLE 6/T.330
+
+#### General value list
+
+| General value                  | Value attribute             |                    |                                                                    | Remarks |
+|--------------------------------|-----------------------------|--------------------|--------------------------------------------------------------------|---------|
+| Name                           | Parameter name              | Code <sup>a)</sup> | Format/Keyword                                                     |         |
+| Call identification            |                             |                    | Each component is separated by the character “ / ”                 |         |
+|                                | TLMAU TID                   | T.61               | Defined in Rec. F.200                                              |         |
+|                                | TLM TID                     | T.61               | Defined in Rec. F.200                                              |         |
+|                                | Date and time               | P                  | YY-MM-DD-HH:mm                                                     |         |
+|                                | Document rel. No.           | N                  | 001 ~ 999                                                          |         |
+|                                | Additional session rel. No. | N                  | 01 ~ 99                                                            |         |
+| Comments                       | —                           | P                  |                                                                    |         |
+| Date and time                  | —                           | P                  | YY-MM-DD-HH:mm                                                     |         |
+| Frequency                      | —                           | N                  | In minutes                                                         |         |
+| IPM identifier                 |                             |                    | <IPM Identifier> ::= <OR Name> “/” <Local Message ID> “>”          |         |
+|                                | Or name                     |                    | See OR name                                                        |         |
+|                                | Local message ID            | A15                | “LID=” <Local Message ID>                                          |         |
+| Message identifier             | —                           | P                  |                                                                    |         |
+| Message length                 | —                           | N                  | In octets                                                          |         |
+| Number of associated documents | —                           | N                  |                                                                    |         |
+| OR descriptor                  | OR name                     |                    | See OR name                                                        |         |
+|                                | Free form name              | T.61               | “Free Form Name=” <Free Form Name>   “FM=” <Free Form Name>        |         |
+|                                | Telephone number            | P                  | “Telephone Number=” <Telephone Number>   “TEL=” <Telephone Number> |         |
+
+TABLE 6/T.330 (cont.)
+
+| General value | Value attribute               |                    |                                                                                                                                                                                | Remarks                   |
+|---------------|-------------------------------|--------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------|
+| Name          | Parameter name                | Code <sup>a)</sup> | Format/Keyword                                                                                                                                                                 |                           |
+| OR name       |                               |                    | <OR Name> ::= <Standard Attribute Lists> <Domain Defined Attribute List>                                                                                                       |                           |
+|               | Standard attribute list       |                    | <Standard Attribute List> ::= “<” <Keyword.Att> (“;” <Keyword.Att>)* “>”                                                                                                       |                           |
+|               | Country name                  | N/P                | “ <b>Country Name</b> =” <Country Name>   “ <b>CN</b> =” <Country Name>                                                                                                        | Default: Country of TLMAU |
+|               | Administration domain name    | N/P                | “ <b>Administration Domain Name</b> =” <Administration Domain Name>   “ <b>ADMD</b> =” <Administration Domain Name>                                                            | Default: ADMD of TLMAU    |
+|               | Network address               | N                  | “ <b>X121 Address</b> =” <Network Address>   “ <b>X121</b> =” <Network Address>   “ <b>Network Address</b> =” <Network Address>                                                |                           |
+|               | Terminal identifier           | P                  | “ <b>Terminal ID</b> =” <Terminal Identifier>   “ <b>TID</b> =” <Terminal Identifier>                                                                                          |                           |
+|               | Private domain name           | N/P                | “ <b>Private Domain Name</b> =” <Private Domain Name>   “ <b>PRMD</b> =” <Private Domain Name>                                                                                 |                           |
+|               | Organisation name             | P                  | “ <b>Organization Name</b> =” <Organization Name>   “ <b>ON</b> =” <Organization Name>                                                                                         |                           |
+|               | Numeric user identifier       | N                  | “ <b>User Agent ID</b> =” <Numeric User Identifier>   “ <b>UAID</b> =” <Numeric User Identifier>   “ <b>NUID</b> =” <Numeric User Identifier>                                  |                           |
+|               | Surname                       | P                  | “ <b>SurName</b> =” <SurName>   “ <b>SN</b> =” <SurName>                                                                                                                       |                           |
+|               | Given name                    | P                  | “ <b>Given Name</b> =” <Given Name>   “ <b>GN</b> =” <Given Name>                                                                                                              |                           |
+|               | Initials                      | P                  | “ <b>Initials</b> =” <Initial>   “ <b>I</b> =” <Initial>                                                                                                                       |                           |
+|               | Generation qualifier          | P                  | “ <b>Generation Qualifier</b> =” <Generation Qualifier>   “ <b>GQ</b> =” <Generation Qualifier>                                                                                |                           |
+|               | Organization unit name        | P                  | “ <b>Organization Unit Name</b> =” <Organization Unit Name>   “ <b>OU</b> =” <Organization Unit Name>                                                                          |                           |
+|               | Domain defined attribute list |                    | <Domain Defined Attributes List> ::= “<DDA=” <Type> “,” <Value> (“,” <Type> “,” <Value>)* “>”   “<Domain Defined Attributes=” <Type> “,” <Value> (“,” <Type> “,” <Value>)* “>” |                           |
+|               | Type                          | P                  |                                                                                                                                                                                |                           |
+|               | Value                         | P                  |                                                                                                                                                                                |                           |
+
+TABLE 6/T.330 (cont.)
+
+| General value          | Value attribute                                |                    |                 | Remarks                                                             |
+|------------------------|------------------------------------------------|--------------------|-----------------|---------------------------------------------------------------------|
+| Name                   | Parameter name                                 | Code <sup>a)</sup> | Format/Keyword  |                                                                     |
+| OR name<br>(continued) | Postal address                                 |                    |                 |                                                                     |
+|                        | PDS-name                                       | P                  | “PDSN=” <value> |                                                                     |
+|                        | Physical delivery country name                 | N/P                | “PDCN=” <value> |                                                                     |
+|                        | Postal code                                    | N/P                | “PC=” <value>   |                                                                     |
+|                        | Physical delivery office name                  | P                  | “PDNA=” <value> |                                                                     |
+|                        | Physical delivery office number                | P                  | “PDNU=” <value> |                                                                     |
+|                        | Extension OR address components                | P                  | “EOA=” <value>  |                                                                     |
+|                        | Physical delivery personal name                | P                  | “PNP=” <value>  |                                                                     |
+|                        | Physical delivery organization name            | P                  | “ONP=” <value>  |                                                                     |
+|                        | Extension physical delivery address components | P                  | “EPD=” <value>  |                                                                     |
+|                        | Unformatted postal address                     | P                  | “UPA=” <value>  | Max. 6 lines,<br>max. 30 characters<br>per line separated<br>by “-” |
+|                        | Street address                                 | P                  | “STA=” <value>  |                                                                     |
+|                        | Post office box address                        | P                  | “POB=” <value>  |                                                                     |
+|                        | Poste restante address                         | P                  | “PRA=” <value>  |                                                                     |
+|                        | Unique postal name                             | P                  | “UN=” <value>   |                                                                     |
+|                        | Local postal attributes                        | P                  | “LPA=” <value>  |                                                                     |
+
+TABLE 6/T.330 (end)
+
+| General value             | Value attribute |                    |                | Remarks |
+|---------------------------|-----------------|--------------------|----------------|---------|
+| Name                      | Parameter name  | Code <sup>a)</sup> | Format/Keyword |         |
+| Retrieval identifier      | –               | N/P                |                |         |
+| Subject                   | –               | T.61               |                |         |
+| Supplementary information | –               | P                  |                |         |
+
+<sup>a)</sup> N = Numeric string in T.61 character set; P = Printable string in T.61 character set; AI5 = string in T.61 character set; T.61 = T.61 string.
+
+<sup>b)</sup> Descr.Att in OR Descriptor and Keyword Att in OR Name contains a Parameter-Id and a parameter-value. The Parameter-Ids appear with bold characters in this table.
+
+*Note 1* – Syntactical conventions are defined as follows and the character size does not make any sense:
+
+<...> Represents a syntactical item, non-terminal
+
+(...)\* Iteration
+
+| Exclusive or alternatives
+
+"abc" Explicit characters abc.
+
+*Note 2* – Maximum length of parameter values can be found in X.400-Series Recommendations.
+
+# 12 Error recovery
+
+This section specifies the error recovery mechanisms for errors which may occur during the communication between a TLM terminal and a TLMAU. The type of recovery will depend upon whether the error occurred during the transmission of control information or a normal document. The recovery mechanism of Recommendation T.62 shall apply. In addition, the qualifications given in the following paragraphs shall apply.
+
+For both directions of transfer, if an error is detected during the transmission of a document containing control information, the transmitted part shall be discarded and the complete TAPDU retransmitted.
+
+If an error is detected during the transmission of a document containing message body, the recovery mechanism depends upon the direction of transfer. In the TLMAU-to-TLM terminal direction, two possibilities for recovery are available, the first one is to apply the rules of Recommendation T.62 using CDC, the second one is the complete retransmission of the TAPDU. In the TLM terminal-to-TLMAU direction, three possible recovery mechanisms are identified, the choice of which is a national matter:
+
+- 1) No recovery is provided. The complete TAPDU (control information and message body) must be retransmitted.
+- 2) The TLMAU shall retain the received part up to the last acknowledged checkpoint. The originating TLM terminal is required to resume the sending of the remainder of the TAPDU by using CDC protocol element as described in Recommendation T.62. The TLMAU shall automatically link the retained part with the resumed part prior to sending to the MTS. If the originating TLM terminal does not resume the sending within a predetermined time or if the TLMAU receives new TAPDU within that time, the TLMAU shall discard the received part of the TAPDU.
+- 3) The last acknowledged normal document is considered the end of the TAPDU. The TLMAU will send this part to the MTS as a complete message. If the TLM terminal wishes to resume transmission of the interrupted TAPDU, it must first resend the control information. There is no correlation between the original message and the continued message at a recipient TLMAU or IPM-UA.
+
+*Note 1* – For failures occurring between document boundaries, the last acknowledged document shall be regarded as the end of the current TAPDU.
+
+*Note 2* – A TAPDU, which may be composed of more than one document, cannot be considered complete before at least two documents were received.
+
+*Note 3* – If there is a relationship between the sequence of normal documents (for example a multi-Part body message) being transferred, the recovery mechanism 2 should not be used.
+
+# 13 Control procedures
+
+## 13.1 *Session control procedure*
+
+The session control procedures shall be in accordance with Recommendation T.612. However, the qualifications listed in the following subsections shall also apply.
+
+### 13.1.1 *Session element of procedure*
+
+The values of mandatory parameters used during session establishment shall be as given in Table 7/T.330. The format of the TLMAU terminal identifier shall be that specified in Recommendation F.200.
+
+### 13.1.2 *Session rules*
+
+Change control (CSCC/RSCCP exchange) may occur inside TAPDU boundaries but should occur outside document boundaries.
+
+## 13.2 *Document control procedures*
+
+The document control procedures shall be in accordance with Recommendation T.62.
+
+Control information is conveyed in either a control document or a normal document. Where encoded information types of the control information is Teletex, the body of the IP-message is conveyed in a sequence (at least one) of normal documents.
+
+*Note* – The use of the normal document for conveying control information should be restricted to Teletex access to IPMS.
+
+TABLE 7/T.330
+
+### **Mandatory parameter values during session establishment**
+
+| T.62<br>parameters                               | Call Originator                                                                                                                  |                                                                                                                           |
+|--------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------|
+|                                                  | TLM terminal                                                                                                                     | TLMAU                                                                                                                     |
+| Terminal identifier of calling terminal (in CSS) | TLM TID                                                                                                                          | TLMAU's TID                                                                                                               |
+| Terminal identifier of called terminal (in RSSP) | TLMAU TID                                                                                                                        | TLM TID                                                                                                                   |
+| Date and time                                    | Date and time the TLM terminal originated call                                                                                   | Date and time the TLMAU terminal originated call                                                                          |
+| Service identifier                               | Telematic                                                                                                                        | Telematic                                                                                                                 |
+| Window size                                      | Note 1                                                                                                                           | Note 1                                                                                                                    |
+| Session user data                                | Basic terminal capabilities and interchange format(s) which are available as receiving capabilities of the TLM terminal (Note 1) | Basic terminal capabilities and interchange format(s) which are available as receiving capabilities of the TLMAU (Note 1) |
+
+*Note 1* – This parameter is mandatory for the Group 4 facsimile service.
+
+*Note 2* – TID means terminal identification.
+
+*Note 3* – Negotiation of the capabilities of handling control document encoded in T.61 characters is not needed.
+
+In a multiple-TAPDU session, the TAPDUs are delimited by at least one of the following methods:
+
+- 1) implicitly, that is, by the first document of the TAPDU being a control document;
+- 2) explicitly, that is, by the first document of the TAPDU containing a parameter indicating the number of subsequence documents in the TAPDU.
+
+*Note* – The second method is mandatory for multiple-action-unit session, where the first document of the TAPDU is a normal document.
+
+When a single TAPDU is sent on a session connection, the TAPDU is delimited only by the end of the session.
+
+## 13.3 *Log-on procedure*
+
+It is conceivable that many subscribers will commonly use a single TLM terminal, some mechanism is required to identify a specific user by intermediate system, i.e. log-on procedure using user name and password. Detailed procedure requires further study.
+
+# ANNEX A
+
+(to Recommendation T.330)
+
+## **Formal definition of TLMA abstract service**
+
+This Annex is an integral part of this Recommendation.
+
+This Annex, a supplement to § 7, formally defines for reference purposes the abstract service TLMA (telematic agent). It uses the PORT and ABSTRACT-BIND, -UNBIND, -OPERATION, and -ERROR macro of Recommendation X.407.
+
+```
+
+TLMAAbsService {ccitt-t330}
+DEFINITIONS IMPLICIT TAGS ::=
+BEGIN
+
+-- Prologue
+EXPORTS
+
+    -- Primary port types
+    miscellanea
+
+IMPORTS
+
+    -- Abstract service
+    origination, reception, management
+    FROM IPMSAbstractService {joint-iso-ccitt
+        mhs(6) imps(1) modules(0) abstract-service(3) }
+    import, export
+    FROM MTSAbstractService {joint-iso-ccitt
+        mhs(6) mts(3) modules(0) mTS-abstract-service(3) }
+
+    -- Information objects and their aspects
+    IPM, RN, NRN
+    FROM IPMSInformationObjects {joint-iso-ccitt
+        mhs(6) ipms(1) modules(0) information-objects(2) }
+
+    -- Functional objects
+    tlma
+    FROM IPMSFunctionalObjects {joint iso-ccitt
+        mhs(6) ipms(1) modules(0) functional-objects(1) }
+
+    -- MTAS aspects
+    MessageDeliveryEnvelope, ORName, MessageIdentifier, Priority, Time, ReportDelivery-Envelope,
+    PerRecipientReportDeliveryFields
+    FROM MTSAbstractService {joint-iso-ccitt
+        mhs(6) mts(3) modules(0) mTS-abstract-service(3) }
+
+    --Abstract services macros
+    OBJECT, PORT, ABSTRACT-BIND, ABSTRACT-ERROR, ABSTRACT-OPERATION
+    From AbstractServiceNotation {joint-iso-ccitt
+        mhs(6) adsdc(2) modules(0) notation(1) }
+
+DatenandTime ::= Time
+
+-- Object
+tlma OBJECT
+    PORTS {
+        origination [S],
+        reception [S],
+        management [S],
+        miscellanea [S],
+        import [C],
+        export [C] }
+    ::= id-ot-tlma
+
+-- Ports
+miscellanea PORT
+    SUPPLIER PERFORMS {
+        ChangeSubscriptionProfile,
+        DSList,
+        DSDelete,
+        DSFetch,
+        MessageStatus }
+    ::= id-pt-miscellanea
+
+```
+
+TLMAAbsService (continuation)
+
+-- *Miscellanea port specific abstract error problems*
+
+SubscriptionProfileProblem ::= ENUMERATED {  
+    not-changed(0) }
+
+DSProblem ::= ENUMERATED {  
+    no-message-in-ds(0),  
+    ds-not-supported(1),  
+    ds-not-subscribed(2),  
+    retrieval-identifier-invalid(3),  
+    parameter-invalid(4) }
+
+MessageStatusProblem ::= ENUMERATED {  
+    query-identifier-invalid(0)
+
+-- *RetrievalIdentifier*
+
+RetrievalIdentifier ::= PrintableString
+
+-- *CallIdentification*
+
+CallIdentification ::= SEQUENCE {  
+    TLMAU TID                   [0] TerminalIdentifier,  
+    TLM TID                    [1] TerminalIdentifier,  
+    date-and-time               [2] DateAndTime,  
+    document-ref-num            [3] DocumentReferenceNumber,  
+    additional-session-ref-num [4] AdditionalSessionReferenceNumber OPTIONAL }
+
+TerminalIdentifier ::= PrintableString     -- *defined in Recommendation F.200* --
+
+DocumentReferenceNumber ::= NumericString
+
+AdditionalSessionReferenceNumber ::= NumericString
+
+-- *Change subscription profile abstract operation component types*
+
+DSMode ::= SET {  
+    [0] Mode,  
+    frequency [1] Frequency OPTIONAL,  
+    time       [2] DateandTime OPTIONAL }
+
+Mode ::= CHOICE {  
+    [0] auto-output,  
+    [1] retrieval }
+
+Frequency ::= NumericString     -- *in minutes* --
+
+ErrorRecoveryMode ::= CHOICE {     -- *see § 12 in this Recommendation* --  
+    [0] recovery-1,                 -- *no-recovery* --  
+    [1] recovery-2,                 -- *full-support-of-T.62-recovery-procedures* --  
+    [2] recovery-3                  -- *recovery-of-document-basis* --}
+
+MessageDeleteMode ::= CHOICE {  
+    [0] auto-delete,  
+    [1] manual-delete }
+
+-- *DS List abstract operation component types*
+
+ListReport ::= SET {  
+    retrieval-id               [0] RetrievalIdentifier,  
+    message-type               [1] MessageType,  
+    priority                    [2] Priority OPTIONAL,  
+    message-length              [3] MessageLength OPTIONAL,  
+    originator-name             [4] ORName OPTIONAL }
+
+MessageType ::= CHOICE {  
+    [0] ipm,  
+    [1] receipt-notice,  
+    [2] non-receipt-notice,  
+    [3] report }
+
+MessageLength ::= NumericString     -- *in octet* --
+
+### *TLMAAbsService (continuation)*
+
+-- *DS Fetch abstract operation component types*
+
+DeleteAfterOutput ::= CHOICE {  
+    [0] delete,  
+    [1] keep }
+
+MessageReport ::= CHOICE {  
+    ipm-fetch      [0] IPMFetch,  
+    rn-fetch       [1] RNFetch,  
+    nrn-fetch      [2] NRNFetch,  
+    report-fetch   [3] ReportFetch }
+
+IPMFetch ::= SEQUENCE {  
+    envelope[0] MessageDeliveryEnvelope,  
+    content [1] IPM }
+
+RNFetch ::= SEQUENCE {  
+    envelope[0] MessageDeliveryEnvelope,  
+    -- *not used intended-recipient-name and other recipient-name of deliver-envelope in RNFetch* --  
+    content [1] RN }
+
+NRNFetch ::= SEQUENCE {  
+    [0] number-of-docs [0] NumberOfAssociatedDocument OPTIONAL,  
+    [1] SET {  
+        envelope        [1] MessageDeliveryEnvelope,  
+        -- *not used intended-recipient-name and other recipient-name of deliver-envelope in NRNFetch* --  
+    content [2] NRN }}
+
+ReportFetch ::= SEQUENCE {  
+    [0] SET {  
+        number-of-docs [0] NumberOfAssociatedDocuments OPTIONAL,  
+        call-id        [1] CallIdentification },  
+    [1] SET {  
+        envelope         [0] ReportDeliveryEnvelope,  
+        returned-content [1] IPM OPTIONAL }}}
+
+NumberOfAssociatedDocuments ::= NumericString
+
+-- *Message status abstract service*
+
+QueryIdentifier ::= CHOICE {  
+    submission-id [0] MessageIdentifier,  
+    call-id       [1] CallIdentification }
+
+StatusInfo ::= SET {  
+                   [0] Status,  
+    per-recipient-info [1] PerRecipientReportDeliveryFields OPTIONAL }
+
+Status ::= CHOICE {  
+    [0] in-process,  
+    [1] delivered,  
+    [2] non-delivered }
+
+-- *Miscellanea abstract-operations*
+
+ChangeSubscriptionProfile ::= ABSTRACT-OPERATION
+
+    ARGUMENT SET {  
+        ds-mode             [0] DSMode OPTIONAL,  
+        error-recovery-mode [1] ErrorRecoveryMode OPTIONAL,  
+        message-delete-mode [2] MessageDeleteMode OPTIONAL }  
+    RESULT { }  
+    ERRORS {  
+        name-error,  
+        ds-error,  
+        subscription-profile-error }
+
+TLMAAbsService (*continuation*)
+
+DSList ::= ABSTRACT-OPERATION
+
+```
+    ARGUMENT {}
+    RESULT SET {
+        list-reports [0] SET OF ListReport OPTIONAL }
+    ERRORS {
+        subscription-error,
+        name-error,
+        ds-error }
+```
+
+DSDelete ::= ABSTRACT-OPERATION
+
+```
+    ARGUMENT SET {
+        selector [0] SET OF RetrievalIdentifier }
+    RESULT
+    ERRORS {
+        subscription-error,
+        name-error,
+        ds-error }
+```
+
+DSFetch ::= ABSTRACT-OPERATION
+
+```
+    ARGUMENT SET {
+        selector [0] SET OF RetrievalIdentifier,
+        delete-after-output [1] DeleteAfterOutput OPTIONAL }
+    RESULT SET {
+        retrieval-id [0] RetrievalIdentifier,
+        message-report [1] MessageReport }
+    ERRORS {
+        subscription-error,
+        name-error,
+        ds-error }
+```
+
+MessageStatus ::= ABSTRACT-OPERATION
+
+```
+    ARGUMENT SET {
+        [0] QueryIdentifier }
+    RESULT SET {
+        report-time [0] DateandTime,
+        reported-message-id [1] MessageIdentifier,
+        [2] SET OF StatusInfo }
+    ERRORS {
+        subscription-error,
+        name-error,
+        message-status-error }
+```
+
+-- *Miscellanea port specific abstract errors*
+
+subscription-profile-error ABSTRACT-ERROR
+
+```
+    PARAMETER SET {
+        problem [0] SubscriptionProfileProblem }
+    ::= 0
+```
+
+ds-error ABSTRACT-ERROR
+
+```
+    PARAMETER SET {
+        problem [0] DSProblem }
+    ::= 1
+```
+
+message-status-error ABSTRACT-ERROR
+
+```
+    PARAMETER SET {
+        problem [0] MessageStatusProblem }
+    ::= 2
+```
+
+END -- *of TLMAAbsService*
+
+## **Format of TAPDU components**
+
+In this Annex the formats of the control information for different examples TAPDUS are shown. The principles of encoding are given in § 11. The formats of elements as defined in § 11 are illustrated by the use of the following four different syntax elements:
+
+- 1) The elements number field is represented by a sequence of numeric graphic characters.
+- 2) The element name field is represented by a text string giving the CCITT language reference name of the field. The actual value shall be a language-dependent representation of that reference name.
+- 3) Separators are shown as they shall be represented in the actual control information.
+- 4) Element value fields are shown in square brackets ("[" and "]"). The actual parameter values are described in § 11.
+
+*Note* - The examples shown below are not exhaustive. Not all types (element value of the TAPDU description in § 10 (ASN.1 description)) are included.
+
+## B.1 *Conventions*
+
+Following symbols are used in this Annex:
+
+- 1) NL new line function such as (CR LF or LF CR) or LF.
+- 2) □ space character.
+- 3) [ ] element value field. Actual values are defined in § 11 of this Recommendation.
+- 4) [ ] iteration.
+
+## B.2 *Example of TAPDU*
+
+### B.2.1 *Send-TAPDU*
+
+- 3.1: □ SEND:
+- 62: □ QUANTITY-OF-DOCS: □ [number-of-docs]
+- 13: □ PRIORITY: □ [priority-ind]
+- 19: □ FLAGS:  
+[deferred-delivery-time] 'NL'  
+= [disclose-recipients],[alternate-recipient-allowed]
+- 16: □ CONVERSION: □ [conversion-prohibited]
+- 17: □ CONTENT-INFO: □ [content-return-request]
+- 27: □ THIS-IPM:  
+[this-ipm-id]
+- 20: □ FROM:  
+[originating-user]
+- 21: □ AUTHORIZING:  
+[ [authorizing-user] 'NL']
+- 22: □ TO:  
+[ [primary-recipient] 'NL' ]  
+=[user-report-request],[rn-request],[nrm-request],[return-request],[reply-request ] 'NL' ]
+
+- 23:  CC:  
+[ [copy-recipient] 'NL'  
+=[rn-request],[nrn-request],[return-request],[reply-request] 'NL' ]
+- 24:  BCC:  
+[ [blind-copy-recipient] 'NL' ]
+- 30:  REPLIED-TO-IPM:  
+[replied-to-ipm-id]
+- 29:  OBSOLETES:  
+[ [obsoleted-ipm-id] 'NL' ]
+- 28:  RELATED-IPMS:  
+[ [related-ipm-id] 'NL' ]
+- 26:  SUBJECT:  
+[subject-content]
+- 18:  CONTENT-INDICATOR:  
+[expiry-time] 'NL'  
+= [importance],[sensitivity]
+- 25:  REPLY:  
+[reply-time] 'NL'  
+[ [reply-recipient] 'NL' ]
+- 31:  BODY-TYPE: [ [body-part], ]
+
+### B.2.2 *SendAck-TAPDU*
+
+- 3.14:  SEND-ACK:
+- 1:  CORRELATION-INFORMATION:  
+[call-id]
+- 65:  SUBMISSION-ID:  
+[submission-msg-id]
+- 33:  SUBMISSION-TIME:  
+[submission-time]
+
+### B.2.3 *Exception-TAPDU*
+
+- 3.12:  EXCEPTION:
+- 1:  CORRELATION-INFORMATION:  
+[call-id]
+- 9:  ERRORS: [error-cause]
+
+### B.2.4 *Probe-TAPDU*
+
+- 3.2:  PROBE:
+
+### B.2.5 *ProbeAck-TAPDU*
+
+- 3.15:□ PROBE-ACK:
+- 1:□ CORRELATION-INFORMATION:  
+[call-id]
+- 66:□ PROBE-ID:  
+[probe-msg-id]
+- 33:□ SUBMISSION-TIME:  
+[submission-time]
+
+### B.2.6 *ExplicitRN-TAPDU*
+
+- 3.6:□ EXPLICIT-RN:
+- 15:□ RECIPIENTS:  
+[recipient-name]
+- 13:□ PRIORITY: □ [priority-ind]
+- 71:□ SUBJECT-IPM:  
+[subject-ipm-id]
+- 69:□ IPN-ORIGINATOR:  
+[ipn-originating-user]
+- 47:□ TIME-OF-RECEIPT:  
+[receipt-time]
+- 44:□ CONVERTED-INFORMATION-TYPES:  
+[ [eIT], ]
+
+### B.2.7 *ExplicitRNack-TAPDU*
+
+- 3.16:□ EXPLICIT-RN-ACK:
+- 1:□ CORRELATION-INFORMATION:  
+[call-id]
+- 65:□ SUBMISSION-ID:  
+[submission-msg-id]
+- 33:□ SUBMISSION-TIME:  
+[submission-time]
+
+### B.2.8 *Cancel-TAPDU*
+
+- 3.13:□ CANCEL:
+- 65:□ SUBMISSION-ID:  
+[submission-msg-id]
+- 1:□ CORRELATION-INFORMATION:  
+[call-id]
+
+### B.2.9 *Deliver-TAPDU*
+
+- 3.3:□ DELIVER:
+- 62:□ QUANTITY-OF-DOCS:□[number-of-docs]
+- 13:□ PRIORITY:□[priority-ind]
+- 14:□ ORIGINATOR:  
+[originator-name]
+- 39:□ THIS-RECIPIENT:  
+[this-recipient-name]
+- 40:□ INTENDED-RECIPIENT:  
+[intended-recipient-name]
+- 41:□ OTHER-RECIPIENTS:  
+[ [other-recipient-name] 'NL']
+- 33:□ SUBMISSION-TIME:  
+[submission-time]
+- 35:□ DELIVERY-ID:  
+[delivery-msg-id]
+- 42:□ CONVERSION-INDICATION:  
+[ [eIT],] [conversion-prohibition]
+- 44:□ CONVERTED-INFORMATION-TYPES:  
+[ [eIT], ]
+- 27:□ THIS-IPM:  
+[this-ipm-id]
+- 20:□ FROM:  
+[originating-user]
+- 21:□ AUTHORIZING:  
+[ [authorizing-user] 'NL']
+- 22:□ TO:  
+[ [primary-recipient] 'NL'  
+=[rn-request],[nrn-request],[return-request],[reply-request] 'NL']
+- 23:□ CC:  
+[ [copy-recipient] 'NL'  
+=[rn-request],[nrn-request],[return-request],[reply-request] 'NL']
+- 24:□ BCC:  
+[[blind-copy-recipient] 'NL'  
+=[rn-request],[nrn-request],[return-request],[reply-request] 'NL']
+- 30:□ REPLIED-TO-IPM:  
+[replied-to-ipm-id]
+- 29:□ OBSOLETES:  
+[ [obsoleted-ipm-id] 'NL']
+- 28:□ RELATED-IPMS:  
+[ [related-ipm-id], 'NL']
+- 26:□ SUBJECT:  
+[subject-content]
+
+- 18:☐ CONTENT-INDICATOR:  
+[expiry-time] 'NL'  
+=[importance],[sensitivity],[autoforwarded]
+- 25:☐ REPLY:  
+[reply-time], 'NL'  
+[ [reply-recipient] 'NL' ]
+- 67:☐ EXTENSIONS:☐  
+[ [extension-type] 'NL'  
+[extension-value] 'NL' ]
+- 31:☐ BODY-TYPE:☐[body-part]
+- 32:☐ FORWARDED-INFO:  
+[forwarded-time] 'NL'  
+  
+//The delivery-envelope follows.
+
+### B.2.10 *ReceiptStatusNotice-TAPDU*
+
+- 3.5:☐ RECEIPT-STATUS-NOTICE:
+- 62:☐ QUANTITY-OF-DOCS:☐[number-of-docs]
+- 13:☐ PRIORITY:☐[priority-ind]
+- 35:☐ DELIVERY-ID:  
+[delivery-id]
+- 14:☐ ORIGINATOR:  
+[originator-name]
+- 39:☐ THIS-RECIPIENT:  
+[this-recipient-name]
+- 33:☐ SUBMISSION-TIME:  
+[submission-time]
+- 4:☐ TIME-OF-DELIVERY:  
+[delivery-time]
+- 42:☐ CONVERSION-INDICATION:  
+[ [eIT], ] [conversion-prohibition]
+- 44:☐ CONVERTED-INFORMATION-TYPES:  
+[ [eIT], ]
+- 43:☐ NOTIFICATION-TYPE:☐[report-type]
+- 71:☐ SUBJECT-IPM:  
+[subject-ipm-id]
+- 69:☐ IPN-ORIGINATOR:  
+[ipn-originating-user]
+- 70:☐ PREFERRED-RECIPIENT:  
+[preferred-recipient]  
+  
+//The following three elements appear in case of RN.
+- 47:☐ TIME-OF-RECEIPT:  
+[receipt-time]
+
+- 48:□ TYPE-OF-RECEIPT:  
+[type-of-receipt]
+- 68:□ SUPPLEMENTARY-INFORMATION:  
+[suppl-receipt-info]  
+//The following three elements appear in case of NRN.
+- 49:□ NON-RECEIPT-INFO:  
+[non-receipt-reason],[discard-reason]
+- 50:□ COMMENTS:  
+[comments]
+- 51:□ MESSAGE-RETURNED-INDICATION:
+
+### B.2.11 *DeliveryStatusNotice-TAPDU*
+
+- 3.4:□ DELIVERY-STATUS-NOTICE:
+- 62:□ QUANTITY-OF-DOCS:□[number-of-docs]
+- 1:□ CORRELATION-INFORMATION:  
+[call-id]
+- 65:□ SUBMISSION-ID:  
+[submission-msg-id]
+- 66:□ PROBE-ID:  
+[probe-msg-id]  
+[ //repeated for each recipient]
+- 3:□ REPORTED-RECIPIENT:  
+[reported-recipient-name]
+- 43:□ NOTIFICATION-TYPE:□[report-type]
+- 40:□ INTENDED-RECIPIENT:  
+[intended-recipient-name]
+- 44:□ CONVERTED-INFORMATION-TYPES:  
+[ [eIT], ]  
+//The following three elements appear in case of DN.
+- 4:□ TIME-OF-DELIVERY:  
+[delivery-time]
+- 45:□ TYPE-OF-UA:  
+[type-of-ua]
+- 68:□ SUPPLEMENTARY-INFORMATION:  
+[suppl-info]  
+//The following two elements appear in case of NDN.
+- 46:□ NON-DELIVERY-REASON:  
+[reason-code],[diagnostic-code]  
+]
+- 72:□ CONTENT-RETURNED-INDICATION:
+
+### B.2.12 *Register-TAPDU*
+
+- 3.11:□ REGISTER:
+- 73:□ EXPIRED-DISCARD:□[discard-ipm]
+- 74:□ OBSOLETE-DISCARD:□[discard-ipm]
+- 76:□ AUTO-FWD-IPMS:□  
+[auto-fwd-ipms]
+- 77:□ AUTO-FWD-RECIPIENTS:□  
+[ [auto-fwd-recipient], ]
+- 78:□ AUTO-FWD-HEADING:□  
+[auto-fwd-heading]
+- 79:□ AUTO-FWD-COMMENT:□  
+[auto-fwd-comment]
+- 58:□ DS-MODE:□[ds-mode]
+- 59:□ TLMAU-OPERATION:□[error-recovery-mode],[auto-acknowledgement]
+- 60:□ AUTO-OUTPUT:  
+[frequency] 'NL'  
+[output-time]
+- 81:□ MESSAGE-DELETE-MODE:□[message-delete-mode]
+- //and other components require further study.
+
+### B.2.13 *RegisterAck-TAPDU*
+
+- 3.11:□ REGISTER-ACK:
+
+### B.2.14 *DSQuery-TAPDU*
+
+- 3.7:□ DS-QUERY:
+
+### B.2.15 *DSReport-TAPDU*
+
+- 3.8:□ DS-REPORT:
+- [ //repeated for each message
+- 38:□ RETRIEVAL-ID:  
+[retrieval-id]
+- 52:□ MESSAGE-TYPE:□[message-type]
+- 14:□ ORIGINATOR:  
+[originator-name]
+- 13:□ PRIORITY:□[priority-ind]
+- 37:□ MESSAGE-LENGTH:□[message-length]
+- ]
+
+### B.2.16 *MessageDelete-TAPDU*
+
+3.18:□ MESSAGE-DELETE:  
+82:□ MESSAGE-SELECTOR:  
+[ [retrieval-id] 'NL' ]
+
+### B.2.17 *OutputRequest-TAPDU*
+
+3.9:□ OUTPUT-REQUEST:  
+[ //repeated for each retrieval identifier  
+38:□ RETRIEVAL-ID:  
+[retrieval-id]  
+80:□ DELETE-AFTER-OUTPUT:□[delete-after-output]  
+]
+
+### B.2.18 *OutputMessage-TAPDU*
+
+3.10:□ OUTPUT-MESSAGE:  
+[ //repeated for each message  
+62:□ QUANTITY-OF-DOCS:□[number-of-docs]  
+38:□ RETRIEVAL-ID:  
+[retrieval-id]  
+52:□ MESSAGE-TYPE:□[message-type]  
+4:□ TIME-OF-DELIVERY:  
+[delivery-time]  
+]
+
+The remaining Components of this TAPDU are identical to the components in the Delivery.  
+DeliveryStatusNotice and ReceiptStatusNotice-TAPDU. The actual components to be used depend upon the Message  
+Type parameter value specified in the Message Type component.
+
+### B.2.19 *StatusQuery-TAPDU*
+
+3.19:□ STATUS-QUERY:  
+14:□ ORIGINATOR:  
+[originator-name]  
+65:□ SUBMISSION-ID:  
+[submission-msg-id]  
+1:□ CORRELATION-INFORMATION:  
+[call-id]
+
+### B.2.20 *StatusReport-TAPDU*
+
+- 3.20:□ STATUS-REPORT:
+- 1:□ CORRELATION-INFORMATION:  
+[call-id]
+- 84:□ TIME-OF-REPORT:  
+[report-time]
+- 75:□ REPORTED-MESSAGE-ID:  
+[reported-message-id]  
+[ //repeated for each message]
+- 83:□ MESSAGE-STATUS:  
+[status]
+- 4:□ TIME-OF-DELIVERY:  
+[delivery-time]
+- 45:□ TYPE-OF-UA:  
+[type-of-ua]
+- 46:□ NON-DELIVERY-REASON:  
+[reason-code],[diagnostic-code]  
+]
+
+# ANNEXE C (to Recommendation T.330)
+
+## Element ID list
+
+This Annex provides a table which maps the coding of TAPDU and the corresponding element ID. The element ID list Table C-1/T.330 comprises:
+
+- 1) The first column contains the element number and element name, as defined in § 11 of this Recommendation.
+- 2) The second column contains the TAPDUId or ElementId name defined in § 10 of this Recommendation.
+- 3) The third column contains the type of the TAPDU element, defined in § 10 of this Recommendation.
+- 4) The fourth column contains the Remarks.
+
+TABLE C-1/T.330
+
+## **Element ID list**
+
+| TAPDUId/element ID                                    | Name                  | Type        | Remarks         |
+|-------------------------------------------------------|-----------------------|-------------|-----------------|
+| 3.1: <input type="checkbox"/> SEND:                   | send                  | —           |                 |
+| 3.2: <input type="checkbox"/> PROBE:                  | probe                 | —           |                 |
+| 3.3: <input type="checkbox"/> DELIVER:                | deliver               | —           |                 |
+| 3.4: <input type="checkbox"/> DELIVERY-STATUS-NOTICE: | deliveryStatusNotice  | —           |                 |
+| 3.5: <input type="checkbox"/> RECEIPT-STATUS-NOTICE:  | receiptStatusNotice   | —           |                 |
+| 3.6: <input type="checkbox"/> EXPLICIT-RN:            | explicitRN            | —           |                 |
+| 3.7: <input type="checkbox"/> DS-QUERY:               | dsQuery               | —           |                 |
+| 3.8: <input type="checkbox"/> DS-REPORT:              | dsReport              | —           |                 |
+| 3.9: <input type="checkbox"/> OUTPUT-REQUEST:         | outputRequest         | —           |                 |
+| 3.10: <input type="checkbox"/> OUTPUT-MESSAGE:        | outputMessage         | —           |                 |
+| 3.11: <input type="checkbox"/> REGISTER:              | register              | —           |                 |
+| 3.12: <input type="checkbox"/> EXCEPTION:             | exception             | —           |                 |
+| 3.13: <input type="checkbox"/> CANCEL:                | cancel                | —           |                 |
+| 3.14: <input type="checkbox"/> SEND-ACK:              | sendAck               | —           |                 |
+| 3.15: <input type="checkbox"/> PROBE-ACK:             | probeAck              | —           |                 |
+| 3.16: <input type="checkbox"/> EXPLICIT-RN-ACK:       | explicitRNAck         | —           |                 |
+| 3.17: <input type="checkbox"/> REGISTER-ACK:          | registerAck           | —           |                 |
+| 3.18: <input type="checkbox"/> MESSAGE-DELETE:        | messageDelete         | —           |                 |
+| 3.19: <input type="checkbox"/> STATUS-QUERY:          | statusQuery           | —           |                 |
+| 3.20: <input type="checkbox"/> STATUS-REPORT:         | statusReport          | —           |                 |
+| 1: <input type="checkbox"/> CORRELATION-INFORMATION:  | correlationInfo       | Primitive   |                 |
+| 2: <input type="checkbox"/>                           |                       |             | Reserved for CF |
+| 3: <input type="checkbox"/> REPORTED-RECIPIENT:       | reportedRecipient     | Primitive   |                 |
+| 4: <input type="checkbox"/> TIME-OF-DELIVERY:         | timeOfDelivery        | Primitive   |                 |
+| 5: <input type="checkbox"/>                           |                       |             | Reserved for CF |
+| 6: <input type="checkbox"/>                           |                       |             | Reserved for CF |
+| 7: <input type="checkbox"/>                           |                       |             | Reserved for CF |
+| 8:                                                    |                       |             | Reserved for CF |
+| 9: <input type="checkbox"/> ERRORS:                   | errors                | Primitive   |                 |
+| 10:                                                   |                       |             | Reserved for CF |
+| 11:                                                   |                       |             | Reserved for CF |
+| 12: <input type="checkbox"/> RECEIVED-TID             |                       |             | Reserved for CF |
+| 13: <input type="checkbox"/> PRIORITY:                | priority              | Primitive   |                 |
+| 14: <input type="checkbox"/> ORIGINATOR:              | originator            | Constructor |                 |
+| 15: <input type="checkbox"/> RECIPIENTS:              | recipients            | Constructor |                 |
+| 16: <input type="checkbox"/> CONVERSION:              | conversion            | Primitive   |                 |
+| 17: <input type="checkbox"/> CONTENT-INFO:            | contentInfo           | Constructor |                 |
+| 18: <input type="checkbox"/> CONTENT-INDICATOR:       | contentIndicator      | Constructor |                 |
+| 19: <input type="checkbox"/> FLAG:                    | per Message Indicator | Constructor |                 |
+
+TABLE C-1/T.330 (cont.)
+
+| TAPDUId/element ID                | Name                 | Type        | Remarks           |
+|-----------------------------------|----------------------|-------------|-------------------|
+| 20:□ FROM:                        | from                 | Primitive   |                   |
+| 21:□ AUTHORIZING:                 | authorizing          | Constructor |                   |
+| 22:□ TO:                          | to                   | Constructor |                   |
+| 23:□ CC:                          | cc                   | Constructor |                   |
+| 24:□ BCC:                         | bcc                  | Constructor |                   |
+| 25:□ REPLY:                       | reply                | Constructor |                   |
+| 26:□ SUBJECT:                     | subject              | Primitive   |                   |
+| 27:□ THIS-IPM:                    | thisIPM              | Primitive   |                   |
+| 28:□ RELATED-IPMS:                | relatedIPMS          | Constructor |                   |
+| 29:□ OBSOLETES:                   | obsoletedIPMS        | Constructor |                   |
+| 30:□ REPLIED-TO-IPM:              | repliedToIPM         | Primitive   |                   |
+| 31:□ BODY-TYPE:                   | bodyType             | Constructor |                   |
+| 32:□ FORWARDED-INFO:              | forwardedInfo        | Constructor | For further study |
+| 33:□ SUBMISSION-TIME:             | submissionTime       | Primitive   |                   |
+| 34:□ LATEST-DELIVERY:             | date and time        | Primitive   |                   |
+| 35:□ DELIVERY-ID:                 | deliveryId           | Primitive   |                   |
+| 36:□ RETURN-ADDRESS:              | return address       | Primitive   |                   |
+| 37:□ MESSAGE-LENGTH:              | messageLength        | Primitive   |                   |
+| 38:□ RETRIEVAL-ID:                | retrievalId          | Primitive   |                   |
+| 39:□ THIS-RECIPIENT:              | thisRecipient        | Primitive   |                   |
+| 40:□ INTENDED-RECIPIENT:          | intendedRecipient    | Primitive   |                   |
+| 41:□ OTHER-RECIPIENTS:            | otherRecipients      | Constructor |                   |
+| 42:□ CONVERSION-INDICATION:       | conversionIndication | Constructor |                   |
+| 43:□ NOTIFICATION-TYPE:           | notificationType     | Primitive   |                   |
+| 44:□ CONVERTED-INFORMATION-TYPES: | convertedInfoTypes   | Primitive   |                   |
+| 45:□ TYPE-OF-UA:                  | typeOfUA             | Primitive   |                   |
+| 46:□ NON-DELIVERY-REASON:         | nonDeliveryReason    | Primitive   |                   |
+| 47:□ TIME-OF-RECEIPT:             | timeOfReceipt        | Primitive   |                   |
+| 48:□ TYPE-OF-RECEIPT:             | typeOfReceipt        | Primitive   |                   |
+| 49:□ NON-RECEIPT-INFO:            | nonReceiptInfo       | Primitive   |                   |
+| 50:□ COMMENT:                     | comment              | Primitive   |                   |
+| 51:□ MESSAGE-RETURNED-INDICATION: | messageReturnedInd   | —           |                   |
+| 52:□ MESSAGE-TYPE:                | messageType          | Primitive   |                   |
+| 53:□ LANGUAGE:                    | languageInd          | Primitive   |                   |
+| 54:□ REDIRECTED-FROM:             | redirected from      | Constructor |                   |
+
+TABLE C-1/T.330 (end)
+
+| TAPDUId/element ID                | Name                          | Type        | Remarks           |
+|-----------------------------------|-------------------------------|-------------|-------------------|
+| 55:□                              | –                             | –           | Not used          |
+| 56:□                              | –                             | –           | Not used          |
+| 57:□                              | –                             | –           | Not used          |
+| 58:□ DS-MODE:                     | dsMode                        | Primitive   |                   |
+| 59:□ TLMAU-OPERATION:             | tLMAUOperation                | Constructor |                   |
+| 60:□ AUTO-OUTPUT:                 | autoOutput                    | Constructor |                   |
+| 61:□                              | –                             | –           | not used          |
+| 62:□ QUANTITY-OF-DOCS:            | quantityOfDocs                | Primitive   |                   |
+| 63:                               |                               |             | Not assigned      |
+| 64:                               |                               |             | Not assigned      |
+| 65:□ SUBMISSION-ID:               | submissionId                  | Primitive   |                   |
+| 66:□ PROBE-ID:                    | probeId                       | Primitive   |                   |
+| 67:□ MSG-INCOMPLETE:              |                               |             |                   |
+| 68:□ SUPPLEMENTARY-INFORMATION:   | supplReceiptInfo<br>SupplInfo | Primitive   |                   |
+| 69:□ IPN-ORIGINATOR:              | IPNOriginator                 | Primitive   |                   |
+| 70:□ PREFERRED-RECIPIENT:         | preferredRecipient            | Primitive   |                   |
+| 71:□ SUBJECT-IPM:                 | subjectIPM                    | Primitive   |                   |
+| 72:□ CONTENT-RETURNED-INDICATION: | contentReturned               | –           |                   |
+| 73:□ EXPIRED-DISCARD:             | expiredDiscard                | Primitive   |                   |
+| 74:□ OBSOLETE-DISCARD:            | obsoletedDiscard              | Primitive   |                   |
+| 75:□ REPORTED-MESSAGE-ID:         | reportedMessageId             | Primitive   |                   |
+| 76:□ AUTO-FWD-IPMS:               | autoFWDIPMs                   | Primitive   |                   |
+| 77:□ AUTO-FWD-RECIPIENTS:         | autoFWDRecipient              | Primitive   |                   |
+| 78:□ AUTO-FWD-HEADING:            | autoFWDHeading                | Constructor | For further study |
+| 79:□ AUTO-FWD-COMMENT:            | autoFWDComment                | Primitive   |                   |
+| 80:□ DELETE-AFTER-OUTPUT:         | deleteAfterOutput             | Primitive   |                   |
+| 81:□ MESSAGE-DELETE-MODE:         | messageDeleteMode             | Primitive   |                   |
+| 82:□ MESSAGE-SELECTOR:            | messageSelector               | Constructor |                   |
+| 83:□ MESSAGE-STATUS:              | messageStatus                 | Primitive   |                   |
+| 84:□ TIME-OF-REPORT:              | timeOfReport                  | Primitive   |                   |
+
+### *Conventions:*
+
+- 1) Primitive: element contains only one component
+- 2) Constructor: element contains more than one component
+- 3) □: space character
+
+# ANNEX D (to Recommendation T.330)
+
+## **Element of service for TTX/IPM service intercommunication**
+
+This PTXAU provides only the services listed in Table D-1/T.330 to telematic users. These services may be implemented using only the mhs-doc-xfer abstract operations: message send, message delivery, receipt status notice and delivery status notice.
+
+When a non-registered user attempts to access a service not within the PTTXAU set of services, then a subscription error will be returned.
+
+TABLE D-1/T.330
+
+## **Element of service**
+
+| Reference<br>Rec. F.400<br>Annex B | F.400 Elements of service                        | Message<br>submission from<br>TTX<br>to PTTXAU | Message delivery<br>to TTX<br>from PTTXAU | Information<br>generated by<br>PTTXAU |
+|------------------------------------|--------------------------------------------------|------------------------------------------------|-------------------------------------------|---------------------------------------|
+| B.5                                | Authorizing users indication                     |                                                | X                                         |                                       |
+| B.6                                | Auto-forwarded indication                        |                                                | X                                         |                                       |
+| B.8                                | Blind copy recipient indication                  |                                                | X                                         |                                       |
+| B.9                                | Body part encryption indication                  |                                                | X                                         |                                       |
+| B.12                               | Content type indication                          |                                                | X                                         | X                                     |
+| B.13                               | Conversion prohibition                           | X                                              | X                                         |                                       |
+| B.15                               | Converted indication                             |                                                | X                                         |                                       |
+| B.18                               | Cross-referencing indication                     |                                                | X                                         |                                       |
+| B.21                               | Delivery notification                            | X                                              | NA                                        | X                                     |
+| B.22                               | Delivery time stamp indication                   |                                                | X                                         | X                                     |
+| B.25                               | Disclosure of other recipients                   | X                                              | X                                         |                                       |
+| B.26                               | DL expansion history indication                  |                                                | X                                         | X                                     |
+| B.29                               | Expiry date indication                           |                                                | X                                         |                                       |
+| B.31                               | Forwarded IP-message indication                  |                                                | X                                         |                                       |
+| B.32                               | Grade of delivery selection                      | X                                              | X                                         |                                       |
+| B.34                               | Implicit conversion                              |                                                | NA                                        | X                                     |
+| B.35                               | Importance indication                            |                                                | X                                         |                                       |
+| B.37                               | IP-message identification                        |                                                | X                                         | X                                     |
+| B.38                               | Language indication                              |                                                | X                                         |                                       |
+| B.39                               | Latest delivery designation                      |                                                | NA                                        | X                                     |
+| B.41                               | Message identification                           |                                                | X                                         |                                       |
+| B.45                               | Multi-destination delivery                       | X                                              | NA                                        |                                       |
+| B.46                               | Multi-part body                                  |                                                | X                                         |                                       |
+| B.47                               | Non-delivery notification                        |                                                | NA                                        |                                       |
+| B.48                               | Non-receipt notification request indication      | X                                              | NA                                        |                                       |
+| B.52                               | Obsoleting indication                            |                                                | X                                         |                                       |
+| B.54                               | Original encoded information types<br>indication |                                                | X                                         | X                                     |
+| B.55                               | Originator indication                            |                                                | X                                         |                                       |
+| B.56                               | Originator requested alternate recipient         |                                                | X                                         |                                       |
+| B.62                               | Primary and copy recipients indication           | X                                              | X                                         |                                       |
+| B.72                               | Reply request indication                         |                                                | X                                         |                                       |
+| B.73                               | Replying IP-message indication                   |                                                | X                                         |                                       |
+| B.80                               | Sensitivity indication                           |                                                | X                                         |                                       |
+| B.88                               | Subject indication                               | X                                              | X                                         |                                       |
+| B.89                               | Submission time stamp indication                 |                                                | X                                         |                                       |
+
+NA Not applicable
+
+X Applicable
\ No newline at end of file
diff --git a/marked/T/T-REC-T.351-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/T/T-REC-T.351-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..f7b1808c9fca1fed71a2098fdda5865c5e7517f8
--- /dev/null
+++ b/marked/T/T-REC-T.351-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:0e8c06416e341bfba04fd37ce9697aee1659c1de6fec5640473c9f3d16300c23
+size 7352
diff --git a/marked/T/T-REC-T.351-198811-I_PDF-E/raw.md b/marked/T/T-REC-T.351-198811-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..1a72c96caeec5a172fa9b3412926296ce95cf78a
--- /dev/null
+++ b/marked/T/T-REC-T.351-198811-I_PDF-E/raw.md
@@ -0,0 +1,196 @@
+
+
+![ITU logo](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg)
+
+The logo of the International Telecommunication Union (ITU) is located in the top left corner. It features a stylized globe with a lightning bolt passing through it, and the letters 'ITU' are prominently displayed across the center of the globe.
+
+ITU logo
+
+INTERNATIONAL TELECOMMUNICATION UNION
+
+**ITU-T**
+
+TELECOMMUNICATION  
+STANDARDIZATION SECTOR  
+OF ITU
+
+**T.351**
+
+**TERMINAL EQUIPMENT AND PROTOCOLS FOR  
+TELEMATIC SERVICES**
+
+---
+
+**IMAGING PROCESS OF CHARACTER  
+INFORMATION ON FACSIMILE APPARATUS**
+
+**ITU-T Recommendation T.351**
+
+(Extract from the *Blue Book*)
+
+---
+
+## NOTES
+
+1 ITU-T Recommendation T.351 was published in Fascicle VII.5 of the *Blue Book*. This file is an extract from the *Blue Book*. While the presentation and layout of the text might be slightly different from the *Blue Book* version, the contents of the file are identical to the *Blue Book* version and copyright conditions remain unchanged (see below).
+
+2 In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+## **Recommendation T.351**
+
+## **IMAGING PROCESS OF CHARACTER INFORMATION ON FACSIMILE APPARATUS**
+
+*(Melbourne, 1988)*
+
+## **0 Introduction**
+
+This Recommendation defines the page formatting characteristics of the information conversion process, for imaging character-information on a facsimile apparatus.
+
+## **1 Scope and field of application**
+
+This Recommendation intends to specify the method for positioning in a correct manner character structured messages, in facsimile pages, conforming to the format defined in Recommendation T.4 Group 3 facsimile apparatus, and Recommendation T.563 for facsimile Group 4 apparatus. The intention is to insure the printing of the information inside the guaranteed printable area of the facsimile pages.
+
+This Recommendation specifies in terms of facsimile picture elements (pels), the initial position and spacing of the characters along the lines and the spacing between the lines, for creating a facsimile page from the character structured information. It does not define neither the shape, nor the repertoire of the characters to be imaged, which is of the responsibility of the application.
+
+Different types of character encoded information, to be printed on both Group 3 and Group 4 facsimile apparatus, are considered, namely teletex, telex, videotex and IA 5 text.
+
+Consideration of mixed mode information requires further study.
+
+This Recommendation applies when interworking implying image conversion between different type of information, including facsimile, is required within a regulated service, such as MHS service.
+
+## **2 References**
+
+- Recommendation F.1: Operational provisions for the international public telegram service.
+- Recommendation S.5: Standardization of page-printing start-stop equipment and cooperation between page-printing and tape-printing start-stop equipment (ITA No. 2).
+- Recommendation T.4: Standardization of Group 3 facsimile apparatus for document transmission.
+- Recommendation T.50: International Alphabet No.5.
+- Recommendation T.60: Terminal equipment for use in the Teletex service.
+- Recommendation T.61: Character repertoire and coded character sets for the international Teletex service.
+- Recommendation T.563: General aspects of Group 4 facsimile apparatus.
+- Recommendation X.408: Message handling systems: Encoded information type conversion rules.
+
+## **3 Definitions**
+
+See the Recommendations quoted in reference.
+
+## **4 Basic principles**
+
+The figures given in this Recommendation, in terms of number of picture elements and facsimile lines, refer to the standard values defined for the resolution in Recommendation T.4 for Group 3 facsimile apparatus (1728 pels/215 mm and 3.85 lines/mm), and in Recommendation T.563 for Group 4 facsimile apparatus (1728 pels/219.46 mm and 200 lines/25.4 mm).
+
+These figures are defined relatively to the transmitted facsimile lines.
+
+The reference position of the first character line is defined using the base line and home position concepts, as defined in Recommendation T.60, Annexes A and B.
+
+## 5 Imaging of Teletex messages
+
+The figures of this Recommendation are derived from the figures given in Recommendation T.60 for the basic printable area of Teletex, with the same capability of printing a defined number of characters in the left margin, relatively to the home position.
+
+The Teletex pages, to be imaged on facsimile equipments, conform to the character repertoire and character sets defined in Recommendation T.61 and to the pages formats defined for the basic printable area in Recommendation T.60.
+
+### 5.1 Reference position
+
+Table 1/T.351 defines the position of the 5th base line and of the home position, relatively to which is referred the first line of written text, according to Recommendation T.60.
+
+Both horizontal and vertical orientations of the paper are considered. For the horizontal orientation, it is assumed that the printing on the facsimile equipment is performed, starting from the left side of the written text.
+
+TABLE 1/T.351
+
+**Reference position for printing Teletex pages**
+
+| Home position |                                      |                               | 5th base line                   |                                    |
+|---------------|--------------------------------------|-------------------------------|---------------------------------|------------------------------------|
+|               | Horizontal orientation<br>(fax line) | Vertical orientation<br>(pel) | Horizontal orientation<br>(pel) | Vertical orientation<br>(fax line) |
+| Fax G3        | 79th                                 | 205th                         | 1474th                          | 82th                               |
+| Fax G4        | 148th                                | 205th                         | 1474th                          | 164th                              |
+
+### 5.2 Character spacing
+
+From the figures of Table 1/T.351, the first character position on each line is defined; the following characters along the line are positioned according to a character spacing value. Table 2/T.351 defines the values to be used for imaging the characters along the lines, depending on the possible value of the spacing defined for the Teletex page format.
+
+TABLE 2/T.351
+
+**Values of character spacings**
+
+| Character spacing value |                                |                                         |                                   |
+|-------------------------|--------------------------------|-----------------------------------------|-----------------------------------|
+|                         | Defined for<br>Teletex<br>(mm) | Horizontal<br>orientation<br>(fax line) | Vertical<br>orientation<br>(pels) |
+| Fax G3                  | 2.54                           | 10                                      | 20                                |
+|                         | 2.12                           | 8                                       | 16                                |
+|                         | 1.69                           | 7                                       | 14                                |
+| Fax G4                  | 2.54                           | 20                                      | 20                                |
+|                         | 2.12                           | 16                                      | 16                                |
+|                         | 1.69                           | 14                                      | 14                                |
+
+### 5.3 *Line spacing*
+
+The position of the first character line in the facsimile page is defined from the figures of Table 1/T.351; the
+
+following character line are positioned according to a line spacing value. Table 3/T.351 defines the values to be used for imaging the characters lines on the facsimile page, depending on the line spacing value defined for the Teletex page format.
+
+TABLE 3/T.351
+
+#### **Values of line spacing**
+
+| Line spacing value |                                |                                     |                                   |
+|--------------------|--------------------------------|-------------------------------------|-----------------------------------|
+|                    | Defined for<br>Teletex<br>(mm) | Horizontal<br>orientation<br>(pels) | Vertical<br>orientation<br>(pels) |
+| Fax G3             | 4.23                           | 32                                  | 16                                |
+|                    | 6.35                           | 48                                  | 24                                |
+|                    | 8.47                           | 64                                  | 32                                |
+|                    | 3.175                          | 24                                  | 12                                |
+|                    | 5                              | 38                                  | 19                                |
+| Fax G4             | 4.23                           | 32                                  | 32                                |
+|                    | 6.35                           | 48                                  | 48                                |
+|                    | 8.47                           | 64                                  | 64                                |
+|                    | 3.175                          | 24                                  | 24                                |
+|                    | 5                              | 38                                  | 38                                |
+
+### 5.4 *Superscript/subscript*
+
+In the Teletex message, the superscript and subscript functionalities, result in an offset in the printing position of the concerned characters. The allowed offset value for imaging the Teletex pages on the facsimile page is defined in Table 4/T.351.
+
+TABLE 4/T.351
+
+#### **Offset values for superscript/subscript**
+
+| Offset value |                                |                                     |                                        |
+|--------------|--------------------------------|-------------------------------------|----------------------------------------|
+|              | Defined for<br>Teletex<br>(mm) | Horizontal<br>orientation<br>(pels) | Vertical<br>orientation<br>(fax lines) |
+| Fax G3       | 2.12                           | 16                                  | 8                                      |
+| Fax G4       | 2.12                           | 16                                  | 16                                     |
+
+## **6 Imaging of Telex messages**
+
+The telex messages conform to the character set defined in Recommendation F.1, and to the format defined in Recommendation S.5.
+
+When imaged on a facsimile equipment, the telex messages are divided in pages of 55 text lines, as a maximum.
+
+Only the vertical orientation of the paper is to be considered.
+
+The first character of each text line in a page is positioned according to the home position defined in Table 1/T.351.
+
+The first line is referred to the 5th base line, as defined in Table 1/T.351.
+
+The character spacing values to be used are those defined in Table 2/T.351 for the 2.54 mm spacing.
+
+The line spacing values to be used are those defined in Table 3/T.351 for the 4.23 mm spacing.
+
+## **7 Imaging of videotex messages**
+
+For further study.
+
+## **8 Imaging of IA 5 text messages**
+
+IA 5 messages conform to the character set defined in Recommendation T.50.
+
+When imaged on a facsimile equipments, IA 5 messages are formatted in pages of 55 lines of 80 characters.
+
+Only the vertical orientation of the paper is to be considered.
+
+The first character of each text line in a page is positioned according to the home position defined in Table 1/T.351.
+
+The first line is referred to the 5th base line, as defined in Table 1/T.351.
+
+The character spacing values to be used are those defined in Table 2/T.351 for the 2.12 mm spacing.
+
+The line spacing values to be used are those defined in Table 3/T.351 for the 4.23 mm spacing.
\ No newline at end of file
diff --git a/marked/T/T-REC-T.36-199707-I_PDF-E/0019f09403376d6444ee323591fa2e98_img.jpg b/marked/T/T-REC-T.36-199707-I_PDF-E/0019f09403376d6444ee323591fa2e98_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..45f6590b3625f3d2a8c2acd4bf88ed6cd3d5eef4
--- /dev/null
+++ b/marked/T/T-REC-T.36-199707-I_PDF-E/0019f09403376d6444ee323591fa2e98_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:7d20442a257a1dea4484a4490b34acb03cee5682795f0612184fac606182365f
+size 27530
diff --git a/marked/T/T-REC-T.36-199707-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/T/T-REC-T.36-199707-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..b73ae7b224334eb2b14f93cf7b97a5c04b08fc15
--- /dev/null
+++ b/marked/T/T-REC-T.36-199707-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:516392c22fcb61c1d767adb7daf3bc0cdef2922b2166d36e6ad5c3a5b93848c5
+size 8330
diff --git a/marked/T/T-REC-T.36-199707-I_PDF-E/78ffccd66df9bafd96e3e081110d09dd_img.jpg b/marked/T/T-REC-T.36-199707-I_PDF-E/78ffccd66df9bafd96e3e081110d09dd_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..dfe59e06553b9800a740d7856f8a73e31fd68a5e
--- /dev/null
+++ b/marked/T/T-REC-T.36-199707-I_PDF-E/78ffccd66df9bafd96e3e081110d09dd_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:bff4f6c4b4c5ce4a7e3eca76713e61487db2acd26781d96d418daab684ae1c79
+size 49774
diff --git a/marked/T/T-REC-T.36-199707-I_PDF-E/raw.md b/marked/T/T-REC-T.36-199707-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..0d803f3e76b099e4bdeef9752e89319a4d4d9119
--- /dev/null
+++ b/marked/T/T-REC-T.36-199707-I_PDF-E/raw.md
@@ -0,0 +1,2096 @@
+
+
+![ITU logo: a globe with the letters ITU and a lightning bolt symbol.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg)
+
+ITU logo: a globe with the letters ITU and a lightning bolt symbol.
+
+INTERNATIONAL TELECOMMUNICATION UNION
+
+# ITU-T
+
+TELECOMMUNICATION  
+STANDARDIZATION SECTOR  
+OF ITU
+
+# T.36
+
+(07/97)
+
+SERIES T: TERMINALS FOR TELEMATIC SERVICES
+
+---
+
+# **Security capabilities for use with Group 3 facsimile terminals**
+
+ITU-T Recommendation T.36
+
+(Previously CCITT Recommendation)
+
+---
+
+# ITU-T T-SERIES RECOMMENDATIONS **TERMINALS FOR TELEMATIC SERVICES**
+
+*For further details, please refer to ITU-T List of Recommendations.*
+
+## **ITU-T RECOMMENDATION T.36**
+
+# **SECURITY CAPABILITIES FOR USE WITH GROUP 3 FACSIMILE TERMINALS**
+
+## **Summary**
+
+This Recommendation defines the two independent technical solutions which may be used in the context of secure facsimile transmission. The two technical solutions are based upon the HKM/HFX40 algorithms and the RSA algorithm.
+
+Annex A contains information regarding the HKM/HFX40 algorithms.
+
+Annex B contains information regarding the RSA algorithm.
+
+Annex C describes the use of the HKM system to provide secure key management capabilities for facsimile terminals. The provision of the capabilities is described in terms of two main procedures:
+
+- the procedure for one way registration between entities X and Y (procREGxy); and
+- the procedure for the secure transmission of a secret key between entities X and Y (procSTKxy).
+
+Annex D covers the procedures for the use of the HFX40 carrier cipher system to provide message confidentiality for facsimile terminals.
+
+Annex E describes the HFX40-I hashing algorithm, in terms of its use, the necessary calculations and the information to be exchanged between the facsimile terminals to provide integrity for a transmitted facsimile message as either a selected or pre-programmed alternative to the encryption of the message.
+
+## **Source**
+
+ITU-T Recommendation T.36 was prepared by ITU-T Study Group 8 (1997-2000) and was approved under the WTSC Resolution No. 1 procedure on the 2nd of July 1997.
+
+## FOREWORD
+
+ITU (International Telecommunication Union) is the United Nations Specialized Agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the ITU. The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis.
+
+The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics.
+
+The approval of Recommendations by the Members of the ITU-T is covered by the procedure laid down in WTSC Resolution No. 1.
+
+In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC.
+
+## NOTE
+
+In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+## INTELLECTUAL PROPERTY RIGHTS
+
+The ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. The ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process.
+
+As of the date of approval of this Recommendation, the ITU had/had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementors are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database.
+
+© ITU 1997
+
+All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU.
+
+# CONTENTS
+
+|                                                                                                                    | <i>Page</i> |
+|--------------------------------------------------------------------------------------------------------------------|-------------|
+| 1 Scope .....                                                                                                      | 1           |
+| 2 References .....                                                                                                 | 1           |
+| 3 Abbreviations .....                                                                                              | 1           |
+| Annex A – Procedures for secure Group 3 document facsimile transmission using the HKM and HFX system ....          | 3           |
+| A.1 Introduction .....                                                                                             | 3           |
+| A.2 Outline of the secure facsimile document procedure .....                                                       | 3           |
+| Annex B – Security in facsimile G3 based on the RSA algorithm .....                                                | 4           |
+| B.1 Preamble .....                                                                                                 | 4           |
+| B.2 Introduction .....                                                                                             | 4           |
+| B.3 References .....                                                                                               | 4           |
+| B.4 Technical description .....                                                                                    | 4           |
+| Annex C – Procedures for the use of the HKM key management system for secure document facsimile transmission ..... | 4           |
+| C.1 Scope .....                                                                                                    | 4           |
+| C.2 Conventions .....                                                                                              | 5           |
+| C.2.1 General .....                                                                                                | 5           |
+| C.2.2 Symbols .....                                                                                                | 5           |
+| C.3 Description of the HKM algorithm for use with facsimile terminals .....                                        | 5           |
+| C.4 Registration mode .....                                                                                        | 6           |
+| C.4.1 Procedure for the registration between entities X and Y (procREGxy) .....                                    | 6           |
+| C.4.2 Procedure for the registration between entities Y and X (procREGyx) .....                                    | 6           |
+| C.4.3 Procedure for registration in a single call .....                                                            | 6           |
+| C.4.4 Authentication of registration .....                                                                         | 7           |
+| C.5 Secure mode .....                                                                                              | 8           |
+| C.5.1 Procedure for the secure transmission of SK from X to Y (procSTKxy) .....                                    | 8           |
+| C.5.2 Use of procSTKxy and procSTKyx in secure mode .....                                                          | 8           |
+| C.5.3 Mutual authentication of X and Y .....                                                                       | 8           |
+| C.5.4 Secure session key establishment between X and Y .....                                                       | 9           |
+| C.5.5 Confirmation of receipt .....                                                                                | 10          |
+| C.5.6 Confirmation or denial of integrity .....                                                                    | 10          |
+| C.6 The HKM algorithm .....                                                                                        | 11          |
+| C.6.1 Introduction .....                                                                                           | 11          |
+| C.6.2 Stored information .....                                                                                     | 11          |
+| C.6.3 Securely stored information .....                                                                            | 11          |
+| C.6.4 Registration mode .....                                                                                      | 12          |
+| C.6.4.1 procREGxy using algebraic notation .....                                                                   | 12          |
+| C.6.4.2 Calculations at X to derive MPx .....                                                                      | 12          |
+| C.6.4.3 Calculations at X to derive TKx .....                                                                      | 13          |
+| C.6.4.4 Calculations at Y to recover MPx by decrypting TKx .....                                                   | 14          |
+| C.6.4.5 Calculations at Y to derive RCNy .....                                                                     | 15          |
+| C.6.5 Secure mode .....                                                                                            | 16          |
+| C.6.5.1 procSTKxy using algebraic notation .....                                                                   | 16          |
+| C.6.5.2 Calculations at X to re-create MPx .....                                                                   | 16          |
+| C.6.5.3 Calculations at X to form ESSKx using HKMD+1 .....                                                         | 17          |
+| C.6.5.4 Calculations at Y to recover SKx .....                                                                     | 18          |
+| C.6.6 The use of the HKM algorithm in secure mode .....                                                            | 21          |
+
+|                                                                                                                                                  |    |
+|--------------------------------------------------------------------------------------------------------------------------------------------------|----|
+| Annex D – Procedures for the use of the HFX40 carrier cipher to provide message confidentiality for secure document facsimile transmission ..... | 21 |
+| D.1 Scope .....                                                                                                                                  | 21 |
+| D.2 Description of the HFX40 algorithm for use with facsimile terminals in secure mode.....                                                      | 22 |
+| D.3 Example calculations for the HFX40 algorithm.....                                                                                            | 22 |
+| D.3.1 Introduction.....                                                                                                                          | 22 |
+| D.3.2 Stored information .....                                                                                                                   | 23 |
+| D.3.3 Selection of the primes.....                                                                                                               | 23 |
+| D.3.4 Calculations using HFX40 to generate 3 PRSs.....                                                                                           | 23 |
+| D.3.5 Use of the tables to encrypt the message and of the multiplexer to modify the tables.....                                                  | 24 |
+| Annex E – Procedures for the use of the HFX40-I hashing system to provide message integrity for secure document facsimile transmission .....     | 27 |
+| E.1 Scope .....                                                                                                                                  | 27 |
+| E.2 Use of the HFX40-I hashing system.....                                                                                                       | 27 |
+| E.3 The HFX40-I hashing system for use with facsimile terminals.....                                                                             | 28 |
+| E.3.1 Introduction.....                                                                                                                          | 28 |
+| E.3.2 Stored information .....                                                                                                                   | 28 |
+| E.3.3 Re-ordering of the system modulating prime numbers .....                                                                                   | 28 |
+| E.3.4 Calculation of the primitives to be used with HFX40-I .....                                                                                | 29 |
+| E.3.5 Calculation of PH.....                                                                                                                     | 30 |
+| E.3.6 First encryption (scrambling) of PH to form SH .....                                                                                       | 30 |
+| E.3.7 Encryption of SH to form ESH.....                                                                                                          | 32 |
+| E.4 Use of the HKM Algorithm to produce a PseudoRandom Sequence .....                                                                            | 32 |
+| E.4.1 Introduction.....                                                                                                                          | 32 |
+| E.4.1.1 Calculations using HKM to generate a PRS .....                                                                                           | 33 |
+
+# SECURITY CAPABILITIES FOR USE WITH GROUP 3 FACSIMILE TERMINALS
+
+(Geneva, 1997)
+
+# 1 Scope
+
+This Recommendation defines the two independent technical solutions which may be used in the context of secure facsimile transmission:
+
+- a solution based on the HKM/HFX40 algorithms as described in Annex A and in Annex G/T.30;
+- a solution based on the RSA algorithm as described in Annex B and in Annex H/T.30.
+
+## 2 References
+
+The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; all users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published.
+
+- ITU-T Recommendation T.30 (1996), *Procedures for document facsimile transmission in the general switched telephone network*.
+
+## 3 Abbreviations
+
+This Recommendation uses the following abbreviations.
+
+|        |                                                                                                                  |
+|--------|------------------------------------------------------------------------------------------------------------------|
+| ASCII  | American Standard Code for Information Interchange                                                               |
+| B(n)   | Base value (n)                                                                                                   |
+| ESH    | Encrypted and Scrambled plain Hash (24 decimal digits)                                                           |
+| ESIM   | Encrypted Scrambled Integrity Message. A 12-decimal digit number                                                 |
+| ESSK   | Encrypted Scrambled Secret Key. A 12-decimal digit number                                                        |
+| HKM    | the HKM encryption algorithm                                                                                     |
+| HKMD+1 | double encryption using the HKM algorithm                                                                        |
+| IDx    | Last six digits of the facsimile identification (facsimile telephone number) of X                                |
+| IDy    | Last six digits of the facsimile identification (facsimile telephone number) of Y                                |
+| IM     | Integrity Message used to confirm or deny integrity of the received message (12 decimal digits)                  |
+| IMy    | Integrity Message generated by Y to confirm or deny integrity of the received message. A 12-digit decimal number |
+| ITU-T  | International Telecommunication Union – Telecommunication Standardization Sector                                 |
+| mod n  | modulo arithmetic using base n                                                                                   |
+
+|                       |                                                                                                                                                                                                                                         |
+|-----------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| MP <sub>x</sub>       | Mutual Primitive of X. A 16-decimal digit number, only generatable by X. MP <sub>x</sub> is produced by X using the HKM algorithm with primitives formed from UIN <sub>x</sub> , UCN <sub>x</sub> , ID <sub>x</sub> and ID <sub>y</sub> |
+| MP <sub>y</sub>       | Mutual Primitive of Y                                                                                                                                                                                                                   |
+| OT                    | One-Time key. A 6- to 64-decimal digit number agreed by both users                                                                                                                                                                      |
+| OT <sub>x</sub>       | One-Time key as first used by X in X's registration with Y                                                                                                                                                                              |
+| OT <sub>y</sub>       | One-Time key as first used by Y, when Y initiates Y's registration with X to complete the mutual registration, whether it is different or identical to OT <sub>x</sub>                                                                  |
+| PH                    | Plain Hash of the message (24 decimal digits)                                                                                                                                                                                           |
+| P(n)                  | Phase value (n)                                                                                                                                                                                                                         |
+| Primitive             | A 64-digit composite number formed from UIN and UCN                                                                                                                                                                                     |
+| procREG <sub>xy</sub> | Procedure for registration between X and Y                                                                                                                                                                                              |
+| procSTK <sub>xy</sub> | Procedure for the secure transmission of a secret key from X to Y                                                                                                                                                                       |
+| PRS                   | PseudoRandom Sequence                                                                                                                                                                                                                   |
+| RCN                   | Registered Crypt Number. A 16-decimal digit number                                                                                                                                                                                      |
+| RNC <sub>n</sub>      | Non-secret random number associated with an SC <sub>n</sub> . A 4-decimal digit number                                                                                                                                                  |
+| RNIM                  | Non-secret random number associated with an IM. A 4-decimal digit number                                                                                                                                                                |
+| RNK                   | Non-secret random number used to provide variation of the primitives generated from MP <sub>x</sub> when encrypting an SK. A 4-decimal digit number                                                                                     |
+| RNSR <sub>n</sub>     | Non-secret random number associated with an SR <sub>n</sub> . A 4-decimal digit number                                                                                                                                                  |
+| RNSS <sub>n</sub>     | Non-secret random number associated with an SS <sub>n</sub> . A 4-decimal digit number                                                                                                                                                  |
+| SC <sub>n</sub>       | Secret Challenge key, number n. A 12-decimal digit number                                                                                                                                                                               |
+| SH                    | Scrambled plain Hash (24 decimal digits)                                                                                                                                                                                                |
+| SK                    | A Secret Key which may be an SC <sub>n</sub> , SR <sub>n</sub> , SS <sub>n</sub> , etc. A 12-decimal digit number                                                                                                                       |
+| SR <sub>n</sub>       | Secret Response key, number n. A 12-decimal digit number                                                                                                                                                                                |
+| SS                    | Secret Session key used with the HFX40-I integrity algorithm (12 decimal digits)                                                                                                                                                        |
+| SSK                   | Scrambled Secret Key. A 12-decimal digit number                                                                                                                                                                                         |
+| SS <sub>n</sub>       | Secret Session key, number n, to be used with the carrier cipher and/or hash. A 12-decimal digit number                                                                                                                                 |
+| SS <sub>x</sub>       | Secret Session key generated by X to be used with the HFX40 cipher algorithm (12 decimal digits)                                                                                                                                        |
+| TK <sub>x</sub>       | Transfer Key, an encryption of MP <sub>x</sub> generated by X. A 16-decimal digit number                                                                                                                                                |
+| UCN                   | Unique Crypt Number, e.g. UCN <sub>x</sub> , UCN <sub>y</sub> . A 16-decimal digit number known only to the system                                                                                                                      |
+
+|       |                                                                                             |
+|-------|---------------------------------------------------------------------------------------------|
+| UIN   | Unique Identity Number, e.g. UINx, UINy. A 48-decimal digit number known only to the system |
+| X     | Name of one entity                                                                          |
+| x     | Suffix identifying ownership or generation by X                                             |
+| XOR'd | Exclusively OR'd                                                                            |
+| Y     | Name of a second entity                                                                     |
+| y     | Suffix identifying ownership or generation by Y                                             |
+
+# **Annex A**
+
+## **Procedures for secure Group 3 document facsimile transmission using the HKM and HFX system**
+
+## **A.1 Introduction**
+
+**A.1.1** This Annex describes the procedures used by Group 3 document facsimile terminals to provide secure communications using the HKM and HFX systems.
+
+**A.1.2** Use of this Annex is optional.
+
+**A.1.3** The error correction defined in Annex A/T.30 or Annex C/T.30 (as appropriate) is mandatory.
+
+## **A.2 Outline of the secure facsimile document procedure**
+
+**A.2.1** The HKM and HFX systems provide the following capabilities for secure document communications between entities (terminals or terminal operators):
+
+- mutual entity authentication;
+- secret session key establishment;
+- document confidentiality;
+- confirmation of receipt;
+- confirmation or denial of document integrity.
+
+### **A.2.2 Functions**
+
+Key management is provided using the HKM system defined in Annex C. Two procedures are defined: the first being registration and the second being the secure transmission of a secret key. Registration establishes mutual secrets and enables all subsequent transmissions to be provided securely. In subsequent transmissions, the HKM system provides mutual authentication, a secret session key for document confidentiality and integrity, confirmation of receipt and a confirmation or denial of document integrity.
+
+Document confidentiality is provided using the carrier cipher defined in Annex D. The carrier cipher uses a 12-decimal digit key which is approximately equivalent to 40 bits.
+
+Document integrity is provided using the system defined in Annex E. Annex E defines the hashing algorithm including the associated calculations and information exchange.
+
+# Annex B
+
+## Security in facsimile G3 based on the RSA algorithm
+
+## B.1 Preamble
+
+(The preamble is left blank on purpose.)
+
+## B.2 Introduction
+
+This Annex specifies the mechanisms to offer security features based on the RSA cryptographic mechanism.
+
+## B.3 References
+
+- ISO/IEC 9796:1991, *Information technology – Security techniques – Digital signature scheme giving message recovery*.
+- RIVEST (R.L.), SHAMIR (A.), ADLEMAN (L.): A method for obtaining digital signatures and public-key cryptosystems, Annex A: RSA, *CACM (Communications of the ACM)*, Vol. 21, No. 2, pp.120-126, 1978.
+- 2nd ISO/IEC CD 10118-3:1995, *Information technology – Security techniques – Hash functions – Part 3: Dedicated hash-functions*.
+- ISO/IEC JTC 1/SC 27 N1108:
+  - SHA-1 (Secure Hash Algorithm), described in *Secure Hash Standard*, FIPS (Federal Information Processing Standard) PUB 180-1, April 1995, an algorithm which comes from the NIST (National Institute of Standardization) in USA.
+  - MD-5 (RFC 1321).
+- ISO/IEC 9979:1991, *Information technology – Security techniques – Procedures for the Registration of cryptographic algorithms*.
+
+## B.4 Technical description
+
+A full description of this solution is given in Annex H/T.30.
+
+# Annex C
+
+## Procedures for the use of the HKM key management system for secure document facsimile transmission
+
+## C.1 Scope
+
+The purpose of this Annex is to define the HKM key management system to be used with facsimile terminals to enable the secure exchange of keys.
+
+The HKM key management system is intended to be applicable for use with all types of dedicated facsimile terminals but is also equally applicable to computer-based facsimile systems.
+
+This Annex describes the use of the HKM algorithm in two main procedures, procREGxy and procSTKxy to provide:
+
+- mutual authentication (described in C.5.3 and C.6.);
+- the use of a carrier cipher to provide message confidentiality (Annex D);
+
+- the use of a hash function to provide message integrity (Annex E);
+- the secure exchange of keys which may be challenge keys, response keys for authentication and session keys for message confidentiality or message integrity (described in C.5 and C.6).
+
+An algebraic notation is developed to assist in the presentation of the key management protocols and procedures, see C.2.
+
+The HKM system is based upon the use of 19 system prime numbers. These same 19 prime numbers are used also with the message cipher algorithm which is described in Annex D and the main message integrity hash algorithm which is described in Annex E. However, this Annex does not cover the message cipher algorithm nor the main message integrity hash algorithm.
+
+Example calculations are given in C.6 and these can be used to verify the implementation of this Annex.
+
+The HKM key management system is covered by intellectual property rights; however, the owner of those rights has agreed to follow the TSB code of practice. Further details can be obtained from the TSB.
+
+## **C.2 Conventions**
+
+### **C.2.1 General**
+
+The algebraic notation detailed in C.2.2 is used to describe the key management protocols and procedures.
+
+### **C.2.2 Symbols**
+
+|                        |                                                                                                      |
+|------------------------|------------------------------------------------------------------------------------------------------|
+| [ ]                    | brackets the message                                                                                 |
+| { }                    | brackets the algorithm                                                                               |
+| ( )                    | brackets the primitives                                                                              |
+| < >                    | brackets information to be stored                                                                    |
+| > <                    | brackets information to be retrieved from store                                                      |
+| &                      | fusing or modifying, for example UCN <sub>x</sub> with ID <sub>x</sub> , without altering its length |
+| RCN <sub>x</sub> >>>>> | RCN <sub>x</sub> sent to Y                                                                           |
+| >>>>> RCN <sub>x</sub> | receive RCN <sub>x</sub> from X                                                                      |
+| HKM+1                  | encryption using the HKM algorithm                                                                   |
+| HKM-1                  | decryption using the HKM algorithm                                                                   |
+| HKMD+1                 | double encryption using the HKM algorithm                                                            |
+| HKMD-1                 | double decryption using the HKM algorithm                                                            |
+
+## **C.3 Description of the HKM algorithm for use with facsimile terminals**
+
+The HKM algorithm uses secret terminal-specific numbers and other user-specific variables to form primitives which, together with an encryption key, provide the input numbers for calculations using modular arithmetic. The secret numbers, UIN and UCN are stored securely in the facsimile terminal on manufacture or commissioning. There is no necessity to cross-reference them against any form of serial number.
+
+The moduli for the modular arithmetic are provided from a set of 19 special prime numbers stored in the terminal.
+
+The output of the modular arithmetical processes are long PRSs that are used to encrypt a message.
+
+HKM is also used in an irreversible mode, that is, where an encryption process takes place, but where the inverse process cannot be performed.
+
+The above features form the cryptographic basis for the two procedures, procREG<sub>xy</sub> and procSTK<sub>xy</sub>.
+
+Details of the arithmetic and the special prime numbers are given in C.6.
+
+### C.4 Registration mode
+
+#### C.4.1 Procedure for the registration between entities X and Y (procREGxy)
+
+For X to register with Y, X generates an irreversible number by cryptographically combining UINx, and UCNx with IDx and IDy. The 16-digit number formed is MPx, which is used to encrypt and securely transfer keys as explained in the following subclauses.
+
+In a secure environment outside the registration transmissions, the users agree an OT. The user at X selects registration mode and enters the facsimile identification (facsimile telephone number) of Y. IDx and IDy form the basis of the other primitives used by the algorithm. The user at X also enters OTx.
+
+X uses OTx with HKM+1 to encrypt MPx to form TKx which is sent to Y. At Y, OTx is entered and is used with HKM–1 to decrypt TKx and to recover MPx.
+
+Y does not store MPx but encrypts it immediately using HKM+1 with primitives formed from UINy and UCNy modified by IDx and IDy to form RCNy. Y sends RCNy to X to be stored. Y has no need to store RCNy, X will send it back openly to Y when X next initiates a secure transmission to Y.
+
+The two terminals implicitly authenticate themselves since X is the only terminal that can create the MPx relating to Y, and Y is the only terminal that can recover the MPx from RCNy.
+
+procREGxy can be shown using the algebraic notation:
+
+![](78ffccd66df9bafd96e3e081110d09dd_img.jpg)
+
+|                                                                                                                                                |                                                                                                                                                  |
+|------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------|
+| <b><u>X</u></b><br>> UINx, UCNx <<br><br>$MPx = (UINx, UCNx \& IDx \& IDy)\{HKM+1\}[UCNx \& IDx \& IDy]$<br>$TKx = (OTx)\{HKM+1\}[MPx]$<br>TKx | <b><u>Y</u></b><br>> UINy, UCNy <<br><br><br><br>TKx<br>$MPx = (OTx)\{HKM-1\}[TKx]$<br>$RCNy = (UINy, UCNy \& IDx \& IDy)\{HKM+1\}[MPx]$<br>RCNy |
+| RCNy<br><RCNy>                                                                                                                                 |                                                                                                                                                  |
+
+A description and examples of all the calculations for procREGxy are given in C.6.4.
+
+#### C.4.2 Procedure for the registration between entities Y and X (procREGyx)
+
+To complete registration, Y carries out an identical procedure, procREGyx, with X which establishes MPy and RCNx. (OTy agreed by the users at Y, and X may be the same or different to OTx used during procREGxy.)
+
+procREGyx can be represented using the algebraic notation:
+
+![](0019f09403376d6444ee323591fa2e98_img.jpg)
+
+|                                                                                                                                              |                                                                                                                                                  |
+|----------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------|
+| <b><u>Y</u></b><br>>UINy, UCNy<<br><br>$MPy = (UINy, UCNy \& IDy \& IDx)\{HKM+1\}[UCNy \& IDy \& IDx]$<br>$TKy = (OTy)\{HKM+1\}[MPy]$<br>TKy | <b><u>X</u></b><br>> UINx, UCNx <<br><br><br><br>TKy<br>$MPy = (OTy)\{HKM-1\}[TKy]$<br>$RCNx = (UINx, UCNx \& IDy \& IDx)\{HKM+1\}[MPy]$<br>RCNx |
+| RCNx<br><RCNx>                                                                                                                               |                                                                                                                                                  |
+
+#### C.4.3 Procedure for registration in a single call
+
+The two separate registrations using procREGxy and procREGyx can be combined into a single call and is shown below using the algebraic notation. In this example, X initiates the call.
+
+6 Recommendation T.36 (07/97)
+
+**X**
+
+>UIN<sub>x</sub>, UCN<sub>x</sub> <
+
+MP<sub>x</sub> = (UIN<sub>x</sub>, UCN<sub>x</sub> & ID<sub>x</sub> & ID<sub>y</sub>) {HKM+1} [UCN<sub>x</sub> & ID<sub>x</sub> & ID<sub>y</sub>]
+
+TK<sub>x</sub> = (OT<sub>x</sub>) {HKM+1} [MP<sub>x</sub>]
+
+TK<sub>x</sub>
+
+RCN<sub>y</sub>, TK<sub>y</sub>
+
+< RCN<sub>y</sub> >
+
+MP<sub>y</sub> = (OT<sub>y</sub>) {HKM–1} [TK<sub>y</sub>]
+
+RCN<sub>x</sub> = (UIN<sub>x</sub>, UCN<sub>x</sub> & ID<sub>y</sub> & ID<sub>x</sub>) {HKM+1} [MP<sub>y</sub>]
+
+RCN<sub>x</sub>
+
+**Y**
+
+>UIN<sub>y</sub>, UCN<sub>y</sub><
+
+TK<sub>x</sub>
+
+MP<sub>x</sub> = (OT<sub>x</sub>) {HKM–1} [TK<sub>x</sub>]
+
+RCN<sub>y</sub> = (UIN<sub>y</sub>, UCN<sub>y</sub> & ID<sub>x</sub> & ID<sub>y</sub>) {HKM+1} [MP<sub>x</sub>]
+
+MP<sub>y</sub> = (UIN<sub>y</sub>, UCN<sub>y</sub> & ID<sub>y</sub> & ID<sub>x</sub>) {HKM+1} [UCN<sub>y</sub> & ID<sub>y</sub> & ID<sub>x</sub>]
+
+TK<sub>y</sub> = (OT<sub>y</sub>) {HKM+1} [MP<sub>y</sub>]
+
+RCN<sub>y</sub>, TK<sub>y</sub>
+
+RCN<sub>x</sub>
+
+< RCN<sub>x</sub> >
+
+### C.4.4 Authentication of registration
+
+Authentication of registration is included in the procedures for the registrations between entities X and Y by providing challenge/response exchanges between X and Y. The challenge/responses use procSTK<sub>xy</sub> and procSTK<sub>yx</sub> as described in C.5.1. An example, within the procedure for two-way registration in a single call, is shown below using the algebraic notation.
+
+**X**
+
+>UIN<sub>x</sub>, UCN<sub>x</sub> <
+
+MP<sub>x</sub> = (UIN<sub>x</sub>, UCN<sub>x</sub> & ID<sub>x</sub> & ID<sub>y</sub>) {HKM+1} [UCN<sub>x</sub> & ID<sub>x</sub> & ID<sub>y</sub>]
+
+TK<sub>x</sub> = (OT<sub>x</sub>) {HKM+1} [MP<sub>x</sub>]
+
+<SC0<sub>x</sub>> by procSTK<sub>xy</sub> = ESSC0<sub>x</sub>
+
+TK<sub>x</sub>, RNC0<sub>x</sub>, ESSC0<sub>x</sub>
+
+RCN<sub>y</sub>, TK<sub>y</sub>, RNSR0<sub>y</sub>, ESSR0<sub>y</sub>, RNC0<sub>y</sub>, ESSC0<sub>y</sub>
+
+< RCN<sub>y</sub> >
+
+MP<sub>y</sub> = (OT<sub>y</sub>) {HKM–1} [TK<sub>y</sub>]
+
+RCN<sub>x</sub> = (UIN<sub>x</sub>, UCN<sub>x</sub> & ID<sub>y</sub> & ID<sub>x</sub>) {HKM+1} [MP<sub>y</sub>]
+
+ESSR0<sub>y</sub> by procSTK<sub>yx</sub> = SR0<sub>y</sub>
+
+Compare SR0<sub>y</sub> with <SC0<sub>y</sub>>
+
+ESSC0<sub>y</sub> by STK<sub>yx</sub> = SC0<sub>y</sub>
+
+SC0<sub>y</sub> = SR0<sub>x</sub>
+
+SR0<sub>x</sub> by STK<sub>xy</sub> = ESSR0<sub>x</sub>
+
+RCN<sub>x</sub>, RNSR0<sub>x</sub>, ESSR0<sub>x</sub>
+
+**Y**
+
+>UIN<sub>y</sub>, UCN<sub>y</sub> <
+
+TK<sub>x</sub>, RNC0<sub>x</sub>, ESSC0<sub>x</sub>
+
+MP<sub>x</sub> = (OT<sub>x</sub>) {HKM–1} [TK<sub>x</sub>]
+
+RCN<sub>y</sub> = (UIN<sub>y</sub>, UCN<sub>y</sub> & ID<sub>x</sub> & ID<sub>y</sub>) {HKM+1} [MP<sub>x</sub>]
+
+MP<sub>y</sub> = (UIN<sub>y</sub>, UCN<sub>y</sub> & ID<sub>y</sub> & ID<sub>x</sub>) {HKM+1} [UCN<sub>y</sub> & ID<sub>y</sub> & ID<sub>x</sub>]
+
+TK<sub>y</sub> = (OT<sub>y</sub>) {HKM+1} [MP<sub>y</sub>]
+
+ESSC0<sub>x</sub> by procSTK<sub>xy</sub> = SC0<sub>x</sub>
+
+SC0<sub>x</sub> = SR0<sub>y</sub>
+
+SR0<sub>y</sub> by procSTK<sub>yx</sub> = ESSR0<sub>y</sub>
+
+<SC0<sub>y</sub>> by procSTK<sub>yx</sub> = ESSC0<sub>y</sub>
+
+RCN<sub>y</sub>, TK<sub>y</sub>, RNSR0<sub>y</sub>, ESSR0<sub>y</sub>, RNC0<sub>y</sub>, ESSC0<sub>y</sub>
+
+>>>>>>RCNx, RNR0x, ESSR0x
+
+<RCNx>
+
+ESSR0x by procSTKxy = SR0x  
+Compare SR0x with <SC0y>
+
+If challenge SC0x is equal to response SR0y and challenge SC0y is equal to response SR0x, mutual authentication of registration between X with Y is achieved.
+
+## C.5 Secure mode
+
+Once registration of MPx and MPy has been established, the HKM algorithm is used to provide the means for secure communication of secret keys between X and Y. The secret keys may be SC, SR, or SS keys. The procedure, procSTKxy, used for this is described in the following subclauses.
+
+### C.5.1 Procedure for the secure transmission of SK from X to Y (procSTKxy)
+
+SKx, a secret key to be securely communicated from X to Y is scrambled and encrypted using HKMD+1 to form ESSKx. The primitives used with HKMD+1 are generated from MPx and modified by RNKx. RNKx is sent openly to Y together with RCNy and ESSKx.
+
+Y recovers MPx using RCNy and unscrambles and decrypts ESSKx using HKMD-1 to recover SKx. The primitives used with HKMD-1 are derived from MPx, modified by RNKx as at X.
+
+procSTKxy can be represented using the algebraic notation:
+
+X
+
+> UINx, UCNx, RCNy <
+
+MPx = (UINx, UCNx & IDx & IDy){HKM+1}[UCNx & IDx & IDy]
+
+ESSKx = (MPx & RNKx){HKMD+1}[SKx]
+
+RCNy, RNKx, ESSKx >>>>>>
+
+Y
+
+> UINy, UCNy, RCNx <
+
+>>>>>> RCNy, RNKx, ESSKx
+
+MPx = (UINy, UCNy & IDx & IDy){HKM-1}[RCNy]
+
+SKx = (MPx & RNKx){HKMD-1}[ESSKx]
+
+A description and examples of all the calculations for procSTKxy are given in C.6.5.
+
+### C.5.2 Use of procSTKxy and procSTKyx in secure mode
+
+Once X and Y have completed registration all future transmissions can be made securely. The HKM algorithm is used in the secure mode to re-create MPx and MPy to enable the secure transfer of secret keys using procSTKxy and procSTKyx.
+
+### C.5.3 Mutual authentication of X and Y
+
+In this context, X has initiated the call to send a secure message to Y.
+
+#### At X
+
+- X enters the facsimile telephone number of Y;
+- X regenerates MPx, previously used in registration between X and Y;
+- X generates SC1x and RNC1x and stores SC1x;
+- X uses procSTKxy with MPx, RNC1x and SC1x to form ESSC1x;
+- X sends RCNy, RNC1x and ESSC1x to Y.
+
+#### At Y
+
+- Y decrypts RCNy to form MPx;
+- Y uses procSTKxy with MPx, RNC1x and ESSC1x to recover SC1x;
+- Y regenerates MPy;
+- Y uses SC1x as the secret response key, SR1y, and generates RNSR1y;
+- Y uses procSTKyx with MPy, RNSR1y and SR1y to form ESSR1y;
+- Y generates SC1y and RNC1y and stores SC1y;
+- Y uses procSTKyx with MPy, RNC1y and SC1y to form ESSC1y;
+- Y sends RCNx, RNSR1y, ESSR1y, RNC1y and ESSC1y to X.
+
+#### At X
+
+- X decrypts RCN<sub>x</sub> to form MP<sub>y</sub>;
+- X uses procSTK<sub>yx</sub> with MP<sub>y</sub>, RNSR<sub>1y</sub> and ESSR<sub>1y</sub> to form SR<sub>1y</sub>;
+- X compares SR<sub>1y</sub> with SC<sub>1x</sub>, if equal, then Y is authenticated to X;
+- X uses procSTK<sub>yx</sub> with MP<sub>y</sub>, RNC<sub>1y</sub> and ESSC<sub>1y</sub> to recover SC<sub>1y</sub>;
+- X uses SC<sub>1y</sub> as the secret response key, SR<sub>1x</sub>, and generates RNSR<sub>1x</sub>;
+- X uses procSTK<sub>xy</sub> with MP<sub>x</sub>, RNSR<sub>1x</sub> and SR<sub>1x</sub> to form ESSR<sub>1x</sub>;
+- X sends RNSR<sub>1x</sub> and ESSR<sub>1x</sub> to Y.
+
+#### At Y
+
+- Y uses procSTK<sub>xy</sub> with MP<sub>x</sub>, RNSR<sub>1y</sub> and ESSR<sub>1x</sub> to recover SR<sub>1x</sub>;
+- Y compares SR<sub>1x</sub> with SC<sub>1y</sub>, if equal, then X is authenticated to Y.
+
+At this point, X and Y have exchanged RCN<sub>x</sub> and RCN<sub>y</sub> and completed mutual/challenge-response exchanges. If SC<sub>1x</sub> is equal to SR<sub>1y</sub> and SC<sub>1y</sub> is equal to SR<sub>1x</sub>, mutual authentication is achieved.
+
+The process of mutual authentication of X and Y can be represented using the algebraic notation:
+
+#### X
+
+> UIN<sub>x</sub>, UCN<sub>x</sub>, RCN<sub>y</sub> <  
+< SC<sub>1x</sub> > by procSTK<sub>xy</sub> = ESSC<sub>1x</sub>  
+RCN<sub>y</sub>, RNC<sub>1x</sub>, ESSC<sub>1x</sub> >>>>>
+
+>>>>> RCN<sub>x</sub>, RNSR<sub>1y</sub>, ESSR<sub>1y</sub>, RNC<sub>1y</sub>, ESSC<sub>1y</sub>  
+< RCN<sub>x</sub> >  
+ESSR<sub>1y</sub> by procSTK<sub>yx</sub> = SR<sub>1y</sub>  
+Compare SR<sub>1y</sub> with < SC<sub>1x</sub> >  
+ESSC<sub>1y</sub> by procSTK<sub>yx</sub> = SC<sub>1y</sub>  
+SC<sub>1y</sub> = SR<sub>1x</sub>  
+SR<sub>1x</sub> by procSTK<sub>xy</sub> = ESSR<sub>1x</sub>  
+RNSR<sub>1x</sub>, ESSR<sub>1x</sub> >>>>>
+
+#### Y
+
+> UIN<sub>y</sub>, UCN<sub>y</sub>, RCN<sub>x</sub> <  
+>>>>> RCN<sub>y</sub>, RNC<sub>1x</sub>, ESSC<sub>1x</sub>  
+< RCN<sub>y</sub> >  
+ESSC<sub>1x</sub> by procSTK<sub>xy</sub> = SC<sub>1x</sub>  
+SC<sub>1x</sub> = SR<sub>1y</sub>  
+SR<sub>1y</sub> by procSTK<sub>yx</sub> = ESSR<sub>1y</sub>  
+< SC<sub>1y</sub> > by procSTK<sub>yx</sub> = ESSC<sub>1y</sub>  
+RCN<sub>x</sub>, RNSR<sub>1y</sub>, ESSR<sub>1y</sub>, RNC<sub>1y</sub>, ESSC<sub>1y</sub> >>>>>
+
+>>>>> RNSR<sub>1x</sub>, ESSR<sub>1x</sub>  
+ESSR<sub>1x</sub> by procSTK<sub>xy</sub> = SR<sub>1x</sub>  
+Compare SR<sub>1x</sub> with < SC<sub>1y</sub> >
+
+If challenge SC<sub>1x</sub> is equal to response SR<sub>1y</sub> and challenge SC<sub>1y</sub> is equal to response SR<sub>1x</sub>, mutual authentication is achieved.
+
+### **C.5.4 Secret session key establishment between X and Y**
+
+In this context, X has initiated a call to send a secure message to Y and mutual authentication has been satisfactorily established as in C.5.3.
+
+#### At X
+
+- X regenerates MP<sub>x</sub> previously used in registration between X and Y;
+- X generates SS<sub>1x</sub> and RNSS<sub>1x</sub>;
+- X uses procSTK<sub>xy</sub> with MP<sub>x</sub>, RNSS<sub>1x</sub> and SS<sub>1x</sub> to form ESSS<sub>1x</sub>;
+- X sends RCN<sub>y</sub>, RNSS<sub>1x</sub> and ESSS<sub>1x</sub> to Y.
+
+#### At Y
+
+- Y decrypts RCN<sub>y</sub> to recover MP<sub>x</sub>;
+- Y uses procSTK<sub>xy</sub> with MP<sub>x</sub>, RNSS<sub>1x</sub> and ESSS<sub>1x</sub> to recover SS<sub>1x</sub>.
+
+The process of secret session key establishment between X and Y can be shown using the algebraic notation:
+
+#### X
+
+< RCN<sub>y</sub> >  
+SS<sub>1x</sub> by procSTK<sub>xy</sub> = ESSS<sub>1x</sub>  
+RCN<sub>y</sub>, RNSS<sub>1x</sub>, ESSS<sub>1x</sub> >>>>>
+
+#### Y
+
+< RCN<sub>x</sub> >  
+>>>>> RCN<sub>y</sub>, RNSS<sub>1x</sub>, ESSS<sub>1x</sub>  
+ESSS<sub>1x</sub> by procSTK<sub>xy</sub> = SS<sub>1x</sub>
+
+X and Y use SS1x with the carrier cipher, HFX40, to encrypt and decrypt the main message to provide confidentiality (Annex D) and/or with the hash algorithm, HFX40-I, to provide message integrity (Annex E) during transmission.
+
+### C.5.5 Confirmation of receipt
+
+In this context, X initiated a call to send a secure message to Y, mutual authentication was established as in C.5.3, SS1x was securely exchanged as in C.5.4 and the message has been sent. At the end of the message, X sends SC2x to Y which Y uses as SR2y if the message was received intact.
+
+#### At X
+
+- X regenerates MPx, previously used in registration between X and Y;
+- X generates SC2x and RNC2x and stores SC2x;
+- X uses procSTKxy with MPx, RNC2x and SC2x to form ESSC2x;
+- X sends RCNy, RNC2x and ESSC2x to Y.
+
+#### At Y
+
+- Y decrypts RCNy to form MPx;
+- Y uses procSTKxy with MPx, RNC1x and ESSC2x to recover SC2x;
+- Y regenerates MPy;
+- Y uses SC2x as SR2y and generates RNSR2y;
+- Y uses procSTKyx with MPy, RNSR2y and SR2y to form ESSR2y;
+- Y sends RCNx, RNSR2y and ESSR2y to X.
+
+#### At X
+
+- X decrypts RCNx to form MPy;
+- X uses procSTKyx with MPy, RNSR2y and ESSR2y to recover SR2y;
+- X compares SR2y with SC2x, if equal, then Y has confirmed receipt to X.
+
+The process of confirmation of receipt can be represented using the algebraic notation:
+
+|                                                                                                                                                                                                                                                         |                                                                                                                                                                                                                      |
+|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| <p><u><b>X</b></u><br/>&gt; RCNy &lt;</p> <p>&lt; SC2x &gt; by procSTKxy = ESSC2x<br/>RCNy, RNC2x, ESSC2x &gt;&gt;&gt;&gt;&gt;</p> <p>&gt;&gt;&gt;&gt;&gt; RCNx, RNSR2y, ESSR2y<br/>ESSR2y by procSTKyx = SR2y<br/>Compare SR2y with &lt; SC2x &gt;</p> | <p><u><b>Y</b></u><br/>&gt; RCNx &lt;</p> <p>&gt;&gt;&gt;&gt;&gt;RCNy, RNC2x, ESSC2x<br/>ESSC2x by procSTKxy = SC2x<br/>SC2x = SR2y<br/>SR2y by procSTKyx = ESSR2y<br/>RCNx, RNSR2y, ESSR2y &gt;&gt;&gt;&gt;&gt;</p> |
+|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+
+If SR2y, from Y equals SC2x stored by X, X accepts confirmation of receipt of the message by Y.
+
+### C.5.6 Confirmation or denial of integrity
+
+In this context, X initiated a call to send a message to Y protected for integrity, mutual authentication has been satisfactorily established as in C.5.3, SSx has been securely exchanged as in C.5.4 and the message has either passed or failed Y's test for integrity (Annex E).
+
+Y generates IMy to confirm or deny the integrity of the received message. IMy is a 12-digit random number selected from the digits 2 to 9. One digit is randomly selected to be replaced with a '1' to indicate confirmation of integrity or a '0' to indicate denial.
+
+#### At Y
+
+- Y generates a 12-digit random number from the digits 2 to 9;
+- Y generates a random number between 1 and 12 to be the replacement pointer for the above random number;
+- Y changes the digit at the replacement point to either a '1' or a '0' to form IMy;
+- Y generates RNIMy;
+- Y uses procSTKyx with MPy, RNIMy and IMy to form ESIMy;
+- Y sends RCNx, RNIMy and ESIMy to X.
+
+#### At X
+
+- X decrypts RCNx to form MPy;
+- X uses procSTKy<sub>x</sub> with MPy, RNIMy and ESIMy to recover IMy;
+- X checks if IMy contains a '1' or a '0' for confirmation or denial of integrity.
+
+The process of confirmation of integrity can be represented using the algebraic notation:
+
+X
+
+Y
+
+> RCNx <
+
+IMy by procSTKy<sub>x</sub> = ESIMy  
+RCNx, RNIMy, ESIMy >>>>>>
+
+>>>>>> RCNx, RNIMy, ESIMy  
+ESIMy by procSTKy<sub>x</sub> = IMy  
+Check IMy for a '1' or a '0'
+
+If the secret Integrity Message contains a '1', integrity is confirmed; if a '0', integrity is denied.
+
+Example responses:
+
+IMy = 257795199982 Integrity confirmed.
+
+IMy = 317736845378 Integrity confirmed.
+
+IMy = 738543680892 Integrity denied.
+
+IMy = 457745204639 Integrity denied.
+
+## **C.6 The HKM algorithm**
+
+### **C.6.1 Introduction**
+
+This subclause describes the HKM algorithm in terms of the numbers to be stored and the rules for the computations carried out using these numbers during the registration procedure, procREG, and the secure transmission of a key procedure, procSTK. The rules are best explained using numerical examples. The calculations using test values can be used to verify the implementation.
+
+### **C.6.2 Stored information**
+
+All terminals are equipped with the same 19 system modulating prime numbers.
+
+32603 32507 32183 32003 31847 31607 31583 31547 31259  
+31139 30803 30539 30467 30347 30323 30203 29879 29759 29663
+
+The first nine numbers are used with the HKM algorithm for registration, authentication and other key management functions. All 19 numbers are used with the message confidentiality algorithm, Annex D, and with the message integrity algorithm, Annex E.
+
+### **C.6.3 Securely stored information**
+
+Each terminal is equipped, by some suitable process, with two randomly generated decimal digit numbers, which are stored securely in the terminal. These are the 48-digit UIN and the 16-digit UCN. UIN and UCN are used with other identifying numbers to form the primitives for the HKM algorithm.
+
+Test examples for X and Y are:
+
+UIN<sub>x</sub> = 345092978336094172898029844342879120988727823781
+
+UCN<sub>x</sub> = 1333908734565521
+
+UIN<sub>y</sub> = 973557693837783148353709167436722873449819767357
+
+UCN<sub>y</sub> = 7598247578649467
+
+### C.6.4 Registration mode
+
+#### C.6.4.1 procREGxy using algebraic notation
+
+X
+
+>UIN<sub>x</sub>, UCN<sub>x</sub><
+
+MP<sub>x</sub> = (UIN<sub>x</sub>, UCN<sub>x</sub> & ID<sub>x</sub> & ID<sub>y</sub>){HKM+1}[UCN<sub>x</sub> & ID<sub>x</sub> & ID<sub>y</sub>]
+
+TK<sub>x</sub> = (OT<sub>x</sub>){HKM+1}[MP<sub>x</sub>]
+
+TK<sub>x</sub> >>>>>
+
+Y
+
+> UIN<sub>y</sub>, UCN<sub>y</sub> <
+
+>>>>> TK<sub>x</sub>
+
+MP<sub>x</sub> = (OT<sub>x</sub>){HKM-1}[TK<sub>x</sub>]
+
+RCN<sub>y</sub> = (UIN<sub>y</sub>, UCN<sub>y</sub> & ID<sub>x</sub> & ID<sub>y</sub>){HKM+1}[MP<sub>x</sub>]
+
+RCN<sub>y</sub> >>>>>
+
+>>>>> RCN<sub>y</sub>
+
+<RCN<sub>y</sub>>
+
+The following subclauses use test values to show all the calculations used in procREGxy:
+
+#### C.6.4.2 Calculations at X to derive MP<sub>x</sub>
+
+MP<sub>x</sub> = (UIN<sub>x</sub>, UCN<sub>x</sub> & ID<sub>x</sub> & ID<sub>y</sub>){HKM+1}[UCN<sub>x</sub> & ID<sub>x</sub> & ID<sub>y</sub>]
+
+##### C.6.4.2.1 Preliminary calculations with the primitives (UIN<sub>x</sub>, UCN<sub>x</sub> & ID<sub>x</sub> & ID<sub>y</sub>)
+
+UIN<sub>x</sub> = 345092978336094172898029844342879120988727823781
+
+UCN<sub>x</sub> = 1333908734565521
+
+ID<sub>x</sub> = 642092
+
+ID<sub>y</sub> = 538249
+
+A 64-digit Primitive is formed by concatenating UIN<sub>x</sub> and UCN<sub>x</sub>.
+
+Primitive = 3450929783360941728980298443428791209887278237811333908734565521
+
+This primitive is split into two 32 digit numbers, 9 phase primitive values [P(0) to P(8)] are derived from the first number and 9 base primitive values [B(0) to B(8)] are derived from the second number. The phase values are derived by dividing the first number into 7 sets of 4 digits and 2 sets of 2 digits. The base values are derived in exactly the same way from the second number.
+
+The phase primitive values are modified by adding incremental products of 101 and the base values are modified by adding incremental products of 79. The modification by 101 and 79 is used to ensure that modulation by the prime numbers starts as soon as possible.
+
+Using the primitive = 3450929783360941728980298443428791209887278237811333908734565521, the phase and base primitive values are as shown below:
+
+P(0) 3450 + (0 \* 101) = 3450
+
+P(1) 9297 + (1 \* 101) = 9398
+
+P(2) 8336 + (2 \* 101) = 8538
+
+P(3) 941 + (3 \* 101) = 1244
+
+P(4) 7289 + (4 \* 101) = 7693
+
+P(5) 8029 + (5 \* 101) = 8534
+
+P(6) 8443 + (6 \* 101) = 9049
+
+P(7) 42 + (7 \* 101) = 749
+
+P(8) 87 + (8 \* 101) = 895
+
+B(0) 9120 + (0 \* 79) = 9120
+
+B(1) 9887 + (1 \* 79) = 9966
+
+B(2) 2782 + (2 \* 79) = 2940
+
+B(3) 3781 + (3 \* 79) = 4018
+
+B(4) 1333 + (4 \* 79) = 1649
+
+B(5) 9087 + (5 \* 79) = 9482
+
+B(6) 3456 + (6 \* 79) = 3930
+
+B(7) 55 + (7 \* 79) = 608
+
+B(8) 21 + (8 \* 79) = 653
+
+The six digit components of ID<sub>x</sub>, 642092, and ID<sub>y</sub>, 538249, are each split into two three digit groups (642, 092, 538 and 249) and are used to further modify P(0) to P(3) and B(0) to B(3):
+
+P(0) = 3450 + 642 = 4092
+
+P(1) = 9398 + 092 = 9490
+
+P(2) = 8538 + 538 = 9076
+
+P(3) = 1244 + 249 = 1493
+
+B(0) = 9120 + 642 = 9762
+
+B(1) = 9966 + 092 = 10058
+
+B(2) = 2940 + 538 = 3478
+
+B(3) = 4018 + 249 = 4267
+
+##### C.6.4.2.2 Preliminary calculations with the message [UCNx & IDx & IDy]
+
+IDx and IDy are concatenated to form a 12-digit number which is added (mod 10) to UCNx to form a modified UCNx.
+
+$$\begin{aligned} \text{IDx concatenated with IDy} &= 642092538249 \\ \text{UCNx} &= 1333908734565521 \\ \text{Modified UCNx} &= 7753823016955521 \end{aligned}$$
+
+##### C.6.4.2.3 Calculations using HKM+1
+
+The HKM+1 algorithm uses the first 9 prime numbers from C.6.2 as moduli for performing modular arithmetic using the 9 phase primitives, P(0) to P(8) and the 9 base primitives, B(0) to B(8) derived in C.6.4.2.1 to generate a 16-entry (mod 10) PRS. The PRS is added (mod 10) to the modified UCNx to form MPx as explained below.
+
+For example, using the first set of phase and base values, P(0), B(0) and the first prime number:
+
+$$\begin{aligned} \text{P(0) is multiplied by B(0)} \\ 4092 * 9762 &= 39946104 \\ 39946104 \text{ (mod the first prime)} &= 39946104 \text{ (mod 32603)} = 7429 \\ 7429 \text{ is then used as a new phase value, P, and is multiplied by the base value, B(0)} \\ 7429 * 9762 &= 72521898 \\ 72521898 \text{ (mod the first prime)} &= 72521898 \text{ (mod 32603)} = 12826 \end{aligned}$$
+
+This process is carried out a total of 16 times (corresponding to the number of digits in the modified UCNx). It is also repeated for the remaining 8 sets of primes, phase and base values.
+
+The results of the first calculation for each of the 9 prime, phase and base "sets" are added. The result (mod 10) is added (mod 10) to the first digit of the modified UCNx to form the first digit of MPx. The process is repeated for each digit of the modified UCNx.
+
+The results of the above operations to produce the MPx, 4314920574868366, from the modified UCNx, 7753823016955521, are given in Table C.1.
+
+**Table C.1/T.36 – Calculations at X to derive MPx**
+
+| Prime<br>B(n)<br>P(n)                                                      | 32603<br>9762<br>4092 | 32507<br>10058<br>9490 | 32183<br>3478<br>9076 | 32003<br>4267<br>1493 | 31847<br>1649<br>7693 | 31607<br>9482<br>8534 | 31583<br>3930<br>9049 | 31547<br>608<br>749 | 31259<br>653<br>895 | Total  | Last<br>digit | Modified<br>crypt<br>number | Mutual<br>Primitive |
+|----------------------------------------------------------------------------|-----------------------|------------------------|-----------------------|-----------------------|-----------------------|-----------------------|-----------------------|---------------------|---------------------|--------|---------------|-----------------------------|---------------------|
+|                                                                            | 7429                  | 9868                   | 26988                 | 2034                  | 10651                 | 5468                  | 112                   | 13734               | 21773               | 98057  | 7             | 7                           | 4                   |
+|                                                                            | 12826                 | 8473                   | 18636                 | 6265                  | 15802                 | 12096                 | 29581                 | 21864               | 26183               | 151726 | 6             | 7                           | 3                   |
+|                                                                            | 11892                 | 20587                  | 31629                 | 10250                 | 6652                  | 24076                 | 27890                 | 12025               | 30085               | 175086 | 6             | 5                           | 1                   |
+|                                                                            | 23024                 | 26963                  | 4168                  | 20652                 | 13780                 | 22878                 | 14690                 | 23843               | 14853               | 164851 | 1             | 3                           | 4                   |
+|                                                                            | 27809                 | 20460                  | 13954                 | 17825                 | 16309                 | 10355                 | 29559                 | 16471               | 8719                | 161461 | 1             | 8                           | 9                   |
+|                                                                            | 18880                 | 17370                  | 48                    | 20147                 | 14673                 | 14768                 | 4596                  | 13969               | 4369                | 108820 | 0             | 2                           | 2                   |
+|                                                                            | 1801                  | 14842                  | 6029                  | 7191                  | 23904                 | 11166                 | 28387                 | 7009                | 8388                | 108717 | 7             | 3                           | 0                   |
+|                                                                            | 8345                  | 8692                   | 17729                 | 25123                 | 22957                 | 24169                 | 9754                  | 2627                | 7039                | 126435 | 5             | 0                           | 5                   |
+|                                                                            | 21596                 | 12813                  | 31017                 | 21794                 | 21857                 | 19708                 | 23041                 | 19866               | 1394                | 173086 | 6             | 1                           | 7                   |
+|                                                                            | 9154                  | 15406                  | 31893                 | 28283                 | 23236                 | 10672                 | 2669                  | 27574               | 3771                | 150658 | 8             | 6                           | 4                   |
+|                                                                            | 29128                 | 25186                  | 21236                 | 11049                 | 4223                  | 17897                 | 3614                  | 13535               | 24261               | 150129 | 9             | 9                           | 8                   |
+|                                                                            | 16773                 | 26244                  | 31006                 | 5664                  | 21081                 | 1371                  | 22253                 | 27060               | 25379               | 176831 | 1             | 5                           | 6                   |
+|                                                                            | 5760                  | 5312                   | 25818                 | 6023                  | 17492                 | 9345                  | 963                   | 16493               | 5217                | 92423  | 3             | 5                           | 8                   |
+|                                                                            | 21548                 | 19095                  | 4434                  | 1732                  | 22773                 | 14869                 | 26213                 | 27345               | 30729               | 168738 | 8             | 5                           | 3                   |
+|                                                                            | 29623                 | 6154                   | 5795                  | 29754                 | 5064                  | 20638                 | 24927                 | 491                 | 29018               | 151464 | 4             | 2                           | 6                   |
+|                                                                            | 23719                 | 3604                   | 8452                  | 4417                  | 6622                  | 10579                 | 24227                 | 14605               | 5800                | 102025 | 5             | 1                           | 6                   |
+| MPx = (UINx, UCNx & IDx & IDy){HKM+1}[UCNx & IDx & IDy] = 4314920574868366 |                       |                        |                       |                       |                       |                       |                       |                     |                     |        |               |                             |                     |
+
+#### C.6.4.3 Calculations at X to derive TKx
+
+$$\text{TKx} = (\text{OTx})\{\text{HKM+1}\}[\text{MPx}]$$
+
+MPx, is encrypted using the HKM+1 algorithm to form the TKx, using OTx.
+
+$$\text{OTx} = 71628582063812097215$$
+
+OTx is expanded by concatenation to form a 64-digit primitive for the HKM algorithm. The 9 phase and 9 base primitive values are formed from the primitive in a similar way to that shown in C.6.4.2.1. There is however no further modification of P(0) to P(3) and B(0) to B(3).
+
+The results of the calculations with the test values to form P(0) to P(8) and B(0) to B(8) using OTx are shown below:
+
+Primitive = 71628582063812097215 71628582063812097215 71628582063812097215 7162
+
+|      |                         |      |                        |
+|------|-------------------------|------|------------------------|
+| P(0) | $7162 + 0 * 101 = 7162$ | B(0) | $1209 + 0 * 79 = 1209$ |
+| P(1) | $8582 + 1 * 101 = 8683$ | B(1) | $7215 + 1 * 79 = 7294$ |
+| P(2) | $638 + 2 * 101 = 840$   | B(2) | $7162 + 2 * 79 = 7320$ |
+| P(3) | $1209 + 3 * 101 = 1512$ | B(3) | $8582 + 3 * 79 = 8819$ |
+| P(4) | $7215 + 4 * 101 = 7619$ | B(4) | $638 + 4 * 79 = 954$   |
+| P(5) | $7162 + 5 * 101 = 7667$ | B(5) | $1209 + 5 * 79 = 1604$ |
+| P(6) | $8582 + 6 * 101 = 9188$ | B(6) | $7215 + 6 * 79 = 7689$ |
+| P(7) | $6 + 7 * 101 = 713$     | B(7) | $71 + 7 * 79 = 624$    |
+| P(8) | $38 + 8 * 101 = 846$    | B(8) | $62 + 8 * 79 = 694$    |
+
+The phase values, P(0) to P(8), the base values, B(0) to B(8) and the 9 primes are used in the same way as in C.6.4.2.3. MPx forms the message and is added (mod 10) to the PRS and is thus encrypted by the HKM+1 algorithm to form TKx. The results of these operations to produce TKx, 5371333066610533, from MPx, 4314920574868366, are given in Table C.2.
+
+**Table C.2/T.36 – Calculations at X to derive TKx**
+
+| Prime<br>B(n)<br>P(n)                      | 32603<br>1209<br>7162 | 32507<br>7294<br>8683 | 32183<br>7320<br>840 | 32003<br>8819<br>1512 | 31847<br>954<br>7619 | 31607<br>1604<br>7667 | 31583<br>7689<br>9188 | 31547<br>624<br>713 | 31259<br>694<br>846 | Total  | Last<br>digit | Mutual<br>Primitive | Transfer<br>Key |
+|--------------------------------------------|-----------------------|-----------------------|----------------------|-----------------------|----------------------|-----------------------|-----------------------|---------------------|---------------------|--------|---------------|---------------------|-----------------|
+|                                            | 19063                 | 10166                 | 1847                 | 21080                 | 7410                 | 2745                  | 26944                 | 3254                | 24462               | 116971 | 1             | 4                   | <b>5</b>        |
+|                                            | 29449                 | 2337                  | 3180                 | 31096                 | 30953                | 9607                  | 19519                 | 11488               | 2991                | 140620 | 0             | 3                   | <b>3</b>        |
+|                                            | 1365                  | 12410                 | 9291                 | 1917                  | 6993                 | 17019                 | 30758                 | 7343                | 12660               | 99756  | 6             | 1                   | <b>7</b>        |
+|                                            | 20135                 | 19052                 | 7441                 | 8439                  | 15299                | 21635                 | 4758                  | 7717                | 2261                | 106737 | 7             | 4                   | <b>1</b>        |
+|                                            | 21377                 | 30370                 | 14484                | 16566                 | 9320                 | 29661                 | 11148                 | 20264               | 6184                | 159374 | 4             | 9                   | <b>3</b>        |
+|                                            | 23217                 | 16082                 | 12078                | 1859                  | 5967                 | 7709                  | 710                   | 25936               | 9213                | 102771 | 1             | 2                   | <b>3</b>        |
+|                                            | 30773                 | 16852                 | 4259                 | 8985                  | 23752                | 6899                  | 26914                 | 453                 | 16986               | 135873 | 3             | 0                   | <b>3</b>        |
+|                                            | 4534                  | 9521                  | 22736                | 31290                 | 16191                | 3546                  | 9930                  | 30296               | 3641                | 131685 | 5             | 5                   | <b>0</b>        |
+|                                            | 4302                  | 11222                 | 9227                 | 16644                 | 419                  | 30131                 | 15659                 | 8051                | 26134               | 121789 | 9             | 7                   | <b>6</b>        |
+|                                            | 17241                 | 642                   | 21706                | 17678                 | 17562                | 3021                  | 7655                  | 7851                | 6776                | 100132 | 2             | 4                   | <b>6</b>        |
+|                                            | 11052                 | 1740                  | 449                  | 15669                 | 2626                 | 9813                  | 20166                 | 9239                | 13694               | 84448  | 8             | 8                   | <b>6</b>        |
+|                                            | 27241                 | 13830                 | 4014                 | 27960                 | 21138                | 31373                 | 15427                 | 23582               | 900                 | 165465 | 5             | 6                   | <b>1</b>        |
+|                                            | 5339                  | 6799                  | 31584                | 28128                 | 6501                 | 3948                  | 24038                 | 14266               | 30679               | 151282 | 2             | 8                   | <b>0</b>        |
+|                                            | 32060                 | 18731                 | 24391                | 5579                  | 23636                | 11192                 | 4466                  | 5730                | 3847                | 129632 | 2             | 3                   | <b>5</b>        |
+|                                            | 28176                 | 29500                 | 23019                | 12590                 | 1068                 | 30799                 | 8353                  | 10709               | 12803               | 157017 | 7             | 6                   | <b>3</b>        |
+|                                            | 27252                 | 9167                  | 21075                | 12803                 | 31615                | 31462                 | 17978                 | 25999               | 7726                | 185077 | 7             | 6                   | <b>3</b>        |
+| TKx = (OTx){HKM+1}[MPx] = 5371333066610533 |                       |                       |                      |                       |                      |                       |                       |                     |                     |        |               |                     |                 |
+
+#### C.6.4.4 Calculations at Y to recover MPx by decrypting TKx
+
+$MPx = (OTx)\{HKM-1\}[TKx]$
+
+OTx = 71628582063812097215
+
+The same processes as those used to derive TKx in C.6.4.3 are carried out using OTx. The same PRS(mod 10) is generated, however for HKM-1 this is subtracted (mod 10) from TKx which forms the *'message'*. This subtraction process decrypts the TKx to recover MPx.
+
+The results of the calculations with the test values to form P(0) to P(8) and B(0) to B(8) using the above OTx are shown below:
+
+Primitive = 71628582063812097215 71628582063812097215 71628582063812097215 7162
+
+$$\begin{aligned}
+P(0) & 7162 + (0 * 101) = 7162 \\
+P(1) & 8582 + (1 * 101) = 8683 \\
+P(2) & 638 + (2 * 101) = 840 \\
+P(3) & 1209 + (3 * 101) = 1512 \\
+P(4) & 7215 + (4 * 101) = 7619 \\
+P(5) & 7162 + (5 * 101) = 7667 \\
+P(6) & 8582 + (6 * 101) = 9188 \\
+P(7) & 6 + (7 * 101) = 713 \\
+P(8) & 38 + (8 * 101) = 846
+\end{aligned}$$
+
+$$\begin{aligned}
+B(0) & 1209 + (0 * 79) = 1209 \\
+B(1) & 7215 + (1 * 79) = 7294 \\
+B(2) & 7162 + (2 * 79) = 7320 \\
+B(3) & 8582 + (3 * 79) = 8819 \\
+B(4) & 638 + (4 * 79) = 954 \\
+B(5) & 1209 + (5 * 79) = 1604 \\
+B(6) & 7215 + (6 * 79) = 7689 \\
+B(7) & 71 + (7 * 79) = 624 \\
+B(8) & 62 + (8 * 79) = 694
+\end{aligned}$$
+
+The phase values, P(0) to P(8), the base values, B(0) to B(8) and the 9 primes are used in the same way as in C.6.4.3. The identical PRS is generated and subtracted (mod 10) from TKx to recover MPx.
+
+The results of the above operations to recover MPx, 4314920574868366, from TKx, 5371333066610533, are given in Table C.3.
+
+**Table C.3/T.36 – Calculations at Y to recover MPx by decrypting TKx**
+
+| Prime<br>B(n)<br>P(n)                                   | 32603<br>1209<br>7162 | 32507<br>7294<br>8683 | 32183<br>7320<br>840 | 32003<br>8819<br>1512 | 31847<br>954<br>7619 | 31607<br>1604<br>7667 | 31583<br>7689<br>9188 | 31547<br>624<br>713 | 31259<br>694<br>846 | Total  | Last<br>digit | Transfer<br>Key | Mutual<br>Primitive |
+|---------------------------------------------------------|-----------------------|-----------------------|----------------------|-----------------------|----------------------|-----------------------|-----------------------|---------------------|---------------------|--------|---------------|-----------------|---------------------|
+|                                                         | 19063                 | 10166                 | 1847                 | 21080                 | 7410                 | 2745                  | 26944                 | 3254                | 24462               | 116971 | 1             | 5               | 4                   |
+|                                                         | 29449                 | 2337                  | 3180                 | 31096                 | 30953                | 9607                  | 19519                 | 11488               | 2991                | 140620 | 0             | 3               | 3                   |
+|                                                         | 1365                  | 12410                 | 9291                 | 1917                  | 6993                 | 17019                 | 30758                 | 7343                | 12660               | 99756  | 6             | 7               | 1                   |
+|                                                         | 20135                 | 19052                 | 7441                 | 8439                  | 15299                | 21635                 | 4758                  | 7717                | 2261                | 106737 | 7             | 1               | 4                   |
+|                                                         | 21377                 | 30370                 | 14484                | 16566                 | 9320                 | 29661                 | 11148                 | 20264               | 6184                | 159374 | 4             | 3               | 9                   |
+|                                                         | 23217                 | 16082                 | 12078                | 1859                  | 5967                 | 7709                  | 710                   | 25936               | 9213                | 102771 | 1             | 3               | 2                   |
+|                                                         | 30773                 | 16852                 | 4259                 | 8985                  | 23752                | 6899                  | 26914                 | 453                 | 16986               | 135873 | 3             | 3               | 0                   |
+|                                                         | 4534                  | 9521                  | 22736                | 31290                 | 16191                | 3546                  | 9930                  | 30296               | 3641                | 131685 | 5             | 0               | 5                   |
+|                                                         | 4302                  | 11222                 | 9227                 | 16644                 | 419                  | 30131                 | 15659                 | 8051                | 26134               | 121789 | 9             | 6               | 7                   |
+|                                                         | 17241                 | 642                   | 21706                | 17678                 | 17562                | 3021                  | 7655                  | 7851                | 6776                | 100132 | 2             | 6               | 4                   |
+|                                                         | 11052                 | 1740                  | 449                  | 15669                 | 2626                 | 9813                  | 20166                 | 9239                | 13694               | 84448  | 8             | 6               | 8                   |
+|                                                         | 27241                 | 13830                 | 4014                 | 27960                 | 21138                | 31373                 | 15427                 | 23582               | 900                 | 165465 | 5             | 1               | 6                   |
+|                                                         | 5339                  | 6799                  | 31584                | 28128                 | 6501                 | 3948                  | 24038                 | 14266               | 30679               | 151282 | 2             | 0               | 8                   |
+|                                                         | 32060                 | 18731                 | 24391                | 5579                  | 23636                | 11192                 | 4466                  | 5730                | 3847                | 129632 | 2             | 5               | 3                   |
+|                                                         | 28176                 | 29500                 | 23019                | 12590                 | 1068                 | 30799                 | 8353                  | 10709               | 12803               | 157017 | 7             | 3               | 6                   |
+|                                                         | 27252                 | 9167                  | 21075                | 12803                 | 31615                | 31462                 | 17978                 | 25999               | 7726                | 185077 | 7             | 3               | 6                   |
+| Mutual primitive = (OTx){HKM-1}[TKx] = 4314920574868366 |                       |                       |                      |                       |                      |                       |                       |                     |                     |        |               |                 |                     |
+
+#### C.6.4.5 Calculations at Y to derive RCNy
+
+$$RCNy = (UINy, UCNy \& IDx \& IDy)\{HKM+1\}[MPx]$$
+
+Y follows the same preliminary calculations for (UINy, UCNy & IDx & IDy) as used by X to calculate MPx in C.6.4.2 but using UINy and UCNy to form the phase and base values. IDx and IDy are used to modify P(0) to P(3) and B(0) to B(3) as before. The phase and base values are used with the first 9 system modulating prime numbers according to the HKM+1 algorithm to develop a (mod 10) PRS which, added to MPx, forms RCNy, which can be communicated openly.
+
+The results of these calculations using the test values are shown below.
+
+$$\text{Unique Identity Number, UINy} = 973557693837783148353709167436722873449819767357$$
+
+$$\text{Unique Crypt Number, UCNy} = 7598247578649467$$
+
+$$\text{Primitive} = 9735576938377831483537091674367228734498197673577598247578649467$$
+
+$$P(0) \quad 9735 + (0 * 101) = 9735$$
+
+$$B(0) \quad 2873 + (0 * 79) = 2873$$
+
+$$P(1) \quad 5769 + (1 * 101) = 5870$$
+
+$$B(1) \quad 4498 + (1 * 79) = 4577$$
+
+$$P(2) \quad 3837 + (2 * 101) = 4039$$
+
+$$B(2) \quad 1976 + (2 * 79) = 2134$$
+
+$$P(3) \quad 7831 + (3 * 101) = 8134$$
+
+$$B(3) \quad 7357 + (3 * 79) = 7594$$
+
+$$\begin{array}{ll}
+ P(4) & 4835 + (4 * 101) = 5239 \\
+ P(5) & 3709 + (5 * 101) = 4214 \\
+ P(6) & 1674 + (6 * 101) = 2280 \\
+ P(7) & 36 + (7 * 101) = 743 \\
+ P(8) & 72 + (8 * 101) = 880 \\
+ B(4) & 7598 + (4 * 79) = 7914 \\
+ B(5) & 2475 + (5 * 79) = 2870 \\
+ B(6) & 7864 + (6 * 79) = 8338 \\
+ B(7) & 94 + (7 * 79) = 647 \\
+ B(8) & 67 + (8 * 79) = 699
+ \end{array}$$
+
+P(0) to P(3), and B(0) to B(3) are modified as before using IDx and IDy  
+IDx = 642092 IDy = 538249
+
+$$\begin{array}{ll}
+ P(0) = 9735 + 642 = 10377 & B(0) = 2873 + 642 = 3515 \\
+ P(1) = 5870 + 092 = 5962 & B(1) = 4577 + 092 = 4669 \\
+ P(2) = 4039 + 538 = 4577 & B(2) = 2134 + 538 = 2672 \\
+ P(3) = 8134 + 249 = 8383 & B(3) = 7594 + 249 = 7843
+ \end{array}$$
+
+The results of the above operations to produce RCNy, 9865418902725854 from MPx, 43149205748688366, are shown in Table C.4.
+
+**Table C.4/T.36 – Calculations at Y to derive RCNy**
+
+| Prime<br>B(n)<br>P(n) | 32603<br>3515<br>10377 | 32507<br>4669<br>5962 | 32183<br>2672<br>4577 | 32003<br>7843<br>8383 | 31847<br>7914<br>5239 | 31607<br>2870<br>4214 | 31583<br>8338<br>2280 | 31547<br>647<br>743 | 31259<br>699<br>880 | Total  | Last<br>digit | Mutual<br>Primitive | Registered<br>Crypt<br>Number |
+|-----------------------|------------------------|-----------------------|-----------------------|-----------------------|-----------------------|-----------------------|-----------------------|---------------------|---------------------|--------|---------------|---------------------|-------------------------------|
+|                       | 25001                  | 10586                 | 204                   | 13707                 | 28499                 | 20306                 | 29257                 | 7516                | 21199               | 156275 | 5             | 4                   | 9                             |
+|                       | 13430                  | 15394                 | 30160                 | 5924                  | 632                   | 26519                 | 29357                 | 4614                | 1335                | 127365 | 5             | 3                   | 8                             |
+|                       | 29909                  | 1609                  | 1288                  | 25579                 | 1669                  | 31481                 | 10416                 | 19840               | 26654               | 148445 | 5             | 1                   | 6                             |
+|                       | 18063                  | 3304                  | 30138                 | 21293                 | 23808                 | 17664                 | 26941                 | 28398               | 782                 | 170391 | 1             | 4                   | 5                             |
+|                       | 13404                  | 18058                 | 6870                  | 9345                  | 9660                  | 29659                 | 15762                 | 13152               | 15215               | 131125 | 5             | 9                   | 4                             |
+|                       | 3725                   | 22151                 | 12330                 | 5965                  | 16440                 | 3679                  | 6693                  | 23201               | 7225                | 101409 | 9             | 2                   | 1                             |
+|                       | 19572                  | 18252                 | 22551                 | 27112                 | 11165                 | 1992                  | 30656                 | 26222               | 17576               | 175098 | 8             | 0                   | 8                             |
+|                       | 3250                   | 17741                 | 9696                  | 11484                 | 16232                 | 27780                 | 8509                  | 24895               | 837                 | 120424 | 4             | 5                   | 9                             |
+|                       | 12700                  | 4893                  | 397                   | 12570                 | 21097                 | 15746                 | 12624                 | 18095               | 22401               | 120523 | 3             | 7                   | 0                             |
+|                       | 6993                   | 25503                 | 30928                 | 17270                 | 19684                 | 24617                 | 24356                 | 3528                | 28799               | 181678 | 8             | 4                   | 2                             |
+|                       | 30336                  | 366                   | 25855                 | 11914                 | 15499                 | 9145                  | 1638                  | 11232               | 30964               | 136949 | 9             | 8                   | 7                             |
+|                       | 19230                  | 18490                 | 19842                 | 24745                 | 16289                 | 12340                 | 13788                 | 11294               | 12608               | 148626 | 6             | 6                   | 2                             |
+|                       | 7431                   | 23725                 | 12423                 | 8843                  | 26337                 | 15960                 | 2224                  | 19861               | 29213               | 146017 | 7             | 8                   | 5                             |
+|                       | 4962                   | 20676                 | 13583                 | 5148                  | 24250                 | 6657                  | 4491                  | 10438               | 7760                | 97965  | 5             | 3                   | 8                             |
+|                       | 31428                  | 22961                 | 23535                 | 19981                 | 4478                  | 14962                 | 20103                 | 2328                | 16433               | 156209 | 9             | 6                   | 5                             |
+|                       | 10456                  | 29330                 | 32121                 | 24295                 | 25028                 | 18634                 | 7833                  | 23507               | 14614               | 185818 | 8             | 6                   | 4                             |
+
+Registered Crypt Number, RCNy = (UINy, UCNy & IDx & IDy) {HKM+1} [MPx] = 9865418902725854
+
+### C.6.5 Secure mode
+
+#### C.6.5.1 procSTKxy using algebraic notation
+
+The following subclauses use test values to show all calculations used in procSTKxy using HKMD to transfer SKx, between X and Y. The secret key may be specifically an SCn, SRn, SSn, etc.
+
+**X**
+
+> UINx, UCNx, RCNy <
+
+(UINx, UCNx & IDx & IDy){HKM+1}[UCNx & IDx & IDy] = MPx  
+(MPx & RNKx){HKMD+1}[SKx] = ESSKx  
+RCNy, RNKx, ESSKx >>>>>
+
+**Y**
+
+> UINy, UCNy <
+
+>>>>> RCNy, RNKx, ESSKx  
+MPx = (UINy, UCNy & IDx & IDy){HKM-1}[RCNy]  
+SKx = (MPx & RNKx){HKMD-1}[ESSKx]
+
+#### C.6.5.2 Calculations at X to re-create MPx
+
+> UINx, UCNx, RCNy <
+
+MPx = (UINx, UCNx & IDx & IDy){HKM+1}[UCNx & IDx & IDy]
+
+The test values and calculations are identical to those shown in C.6.4.2 giving:
+
+$$MP_x = (UIN_x, UCN_x \& ID_x \& ID_y)\{HKM+1\}[UCN_x \& ID_x \& ID_y] = 4314920574868366$$
+
+#### C.6.5.3 Calculations at X to form ESSK<sub>x</sub> using HKMD+1
+
+$$ESSK_x = (MP_x \& RNK_x)\{HKMD+1\}[SK_x]$$
+
+SK<sub>x</sub> is doubly encrypted using HKMD+1, the first encryption being a scrambling process based on a 12-digit (mod 12) PRS generated using HKM to form SSK<sub>x</sub>, and the second encryption is the normal (mod 10) addition to the 'message', SSK<sub>x</sub>, of the (mod 10) PRS generated using HKM.
+
+##### C.6.5.3.1 Calculations at X to form SSK<sub>x</sub>
+
+MP<sub>x</sub> is repeated and concatenated to form the 64-digit Primitive which is used to derive the phase and base primitive values as shown below.
+
+$$\text{Primitive} = 4314920574868366 \ 4314920574868366 \ 4314920574868366 \ 4314920574868366$$
+
+|      |                           |      |                          |
+|------|---------------------------|------|--------------------------|
+| P(0) | $4314 + (0 * 101) = 4314$ | B(0) | $4314 + (0 * 79) = 4314$ |
+| P(1) | $9205 + (1 * 101) = 9306$ | B(1) | $9205 + (1 * 79) = 9284$ |
+| P(2) | $7486 + (2 * 101) = 7688$ | B(2) | $7486 + (2 * 79) = 7644$ |
+| P(3) | $8366 + (3 * 101) = 8669$ | B(3) | $8366 + (3 * 79) = 8603$ |
+| P(4) | $4314 + (4 * 101) = 4718$ | B(4) | $4314 + (4 * 79) = 4630$ |
+| P(5) | $9205 + (5 * 101) = 9710$ | B(5) | $9205 + (5 * 79) = 9600$ |
+| P(6) | $7486 + (6 * 101) = 8092$ | B(6) | $7486 + (6 * 79) = 7960$ |
+| P(7) | $83 + (7 * 101) = 790$    | B(7) | $83 + (7 * 79) = 636$    |
+| P(8) | $66 + (8 * 101) = 874$    | B(8) | $66 + (8 * 79) = 698$    |
+
+RNK<sub>x</sub>, associated with SK<sub>x</sub>, is divided into 2 pairs of 2 digits and the first pair is added to P(0) and the second pair to P(1) to give new values of P(0) and P(1); new values for B(0) and B(1) are created in an identical manner.
+
+$$RNK_x = 3958$$
+
+|                           |                           |
+|---------------------------|---------------------------|
+| $P(0) = 4314 + 39 = 4353$ | $B(0) = 4314 + 39 = 4353$ |
+| $P(1) = 9306 + 58 = 9364$ | $B(1) = 9284 + 58 = 9342$ |
+
+The prime numbers and the phase and base values are then used with HKM to generate a 12-digit PRS, (mod 12) + 1, (that is, the "Total" column is modulated to the base 12 and 1 is added to produce the PRS). The results of the calculations are given in Table C.5.
+
+**Table C.5/T.36 – Calculations at X to form the (mod 12) + 1 scrambler/descrambler PRS**
+
+| Prime<br>B(n)<br>P(n) | 32603<br>4353<br>4353 | 32507<br>9342<br>9364 | 32183<br>7644<br>7688 | 32003<br>8603<br>8669 | 31847<br>4630<br>4718 | 31607<br>9600<br>9710 | 31583<br>7960<br>8092 | 31547<br>636<br>790 | 31259<br>698<br>874 | Total  | (mod 12) + 1<br>PRS |
+|-----------------------|-----------------------|-----------------------|-----------------------|-----------------------|-----------------------|-----------------------|-----------------------|---------------------|---------------------|--------|---------------------|
+|                       | 6266                  | 2151                  | 914                   | 12417                 | 29145                 | 6957                  | 14583                 | 29235               | 16131               | 117799 | 8                   |
+|                       | 19790                 | 5316                  | 2905                  | 29440                 | 5611                  | 1609                  | 13155                 | 12277               | 6198                | 96301  | 2                   |
+|                       | 8744                  | 23883                 | 31733                 | 578                   | 23625                 | 22184                 | 16155                 | 16063               | 12462               | 155427 | 4                   |
+|                       | 14931                 | 19445                 | 3781                  | 12069                 | 21152                 | 30041                 | 19407                 | 26387               | 8474                | 155687 | 12                  |
+|                       | 16864                 | 6074                  | 1630                  | 11875                 | 4235                  | 11332                 | 7267                  | 30675               | 6901                | 96853  | 2                   |
+|                       | 19639                 | 18593                 | 4899                  | 7049                  | 22145                 | 27513                 | 16847                 | 13254               | 3012                | 132951 | 4                   |
+|                       | 3501                  | 10905                 | 19127                 | 28865                 | 15857                 | 16708                 | 702                   | 6495                | 8023                | 110183 | 12                  |
+|                       | 14252                 | 30079                 | 31602                 | 14318                 | 10575                 | 22882                 | 29312                 | 29710               | 4693                | 187423 | 8                   |
+|                       | 28050                 | 7510                  | 90                    | 30210                 | 13411                 | 30157                 | 19899                 | 30454               | 24778               | 184559 | 12                  |
+|                       | 3415                  | 8314                  | 12117                 | 267                   | 23127                 | 18687                 | 7295                  | 30433               | 8817                | 112472 | 9                   |
+|                       | 31130                 | 10165                 | 31857                 | 24788                 | 8396                  | 25475                 | 18646                 | 17077               | 27502               | 195036 | 1                   |
+|                       | 10822                 | 8483                  | 18330                 | 15175                 | 20140                 | 16641                 | 13643                 | 8804                | 3370                | 115408 | 5                   |
+
+The resultant scrambler/descrambler PRS is then used as the scrambler to scramble the SK<sub>x</sub>. The first digit in the scrambler indicates which digit in SK<sub>x</sub> should be interchanged with the first digit in SK<sub>x</sub>. The second digit in the scrambler indicates the interchange for the second digit of the SK<sub>x</sub> and so on for the remaining digits. The results of this scrambling process to produce SSK<sub>x</sub>, 721647935700, from SK<sub>x</sub>, 309126704577, are shown below.
+
+###### Scrambler PRS
+
+|    |                                                 |
+|----|-------------------------------------------------|
+| 8  | <u>3</u> 091267 <u>0</u> 4577 = SK <sub>x</sub> |
+| 2  | 0 <u>0</u> 9126734577                           |
+| 4  | 00 <u>9</u> 126734577                           |
+| 12 | 001 <u>9</u> 26734577                           |
+| 2  | 0017 <u>2</u> 673457 <u>9</u>                   |
+| 4  | 0217 <u>0</u> 6734579                           |
+| 12 | 021607 <u>7</u> 3457 <u>9</u>                   |
+| 8  | 0216079 <u>3</u> 4577                           |
+| 12 | 02160793 <u>4</u> 577                           |
+| 9  | 021607937 <u>5</u> 74                           |
+| 1  | <u>0</u> 21607935774                            |
+| 5  | 7216 <u>0</u> 7935704                           |
+|    | 721647935700 = SSK <sub>x</sub>                 |
+
+##### C.6.5.3.2 Calculations at X to form ESSK<sub>x</sub>
+
+The same calculations using HKM as in C.6.5.3.1 are used to generate a 12-digit (mod 10) PRS, which is added (mod 10) to SSK<sub>x</sub>, to produce ESSK<sub>x</sub>.
+
+The results of the calculations to produce ESSK<sub>x</sub>, 638378264968, from SSK<sub>x</sub>, 721647935700, are given in Table C.6.
+
+**Table C.6/T.36 – Calculations at X to form ESSK<sub>x</sub>**
+
+| Prime<br>B(n)<br>P(n)                                                   | 32603<br>4353<br>4353 | 32507<br>9342<br>9364 | 32183<br>7644<br>7688 | 32003<br>8603<br>8669 | 31847<br>4630<br>4718 | 31607<br>9600<br>9710 | 31583<br>7960<br>8092 | 31547<br>636<br>790 | 31259<br>698<br>874 | Total  | Last<br>digit | Scrambled<br>Secret<br>Key | Encrypted<br>Scrambled<br>Secret<br>Key |
+|-------------------------------------------------------------------------|-----------------------|-----------------------|-----------------------|-----------------------|-----------------------|-----------------------|-----------------------|---------------------|---------------------|--------|---------------|----------------------------|-----------------------------------------|
+|                                                                         | 6266                  | 2151                  | 914                   | 12417                 | 29145                 | 6957                  | 14583                 | 29235               | 16131               | 117799 | 9             | 7                          | <b>6</b>                                |
+|                                                                         | 19790                 | 5316                  | 2905                  | 29440                 | 5611                  | 1609                  | 13165                 | 12277               | 6198                | 96301  | 1             | 2                          | <b>3</b>                                |
+|                                                                         | 8744                  | 23883                 | 31733                 | 578                   | 23625                 | 22184                 | 16155                 | 16063               | 12462               | 155427 | 7             | 1                          | <b>8</b>                                |
+|                                                                         | 14931                 | 19445                 | 3781                  | 12069                 | 21152                 | 30041                 | 19407                 | 26387               | 8474                | 155687 | 7             | 6                          | <b>3</b>                                |
+|                                                                         | 16864                 | 6074                  | 1630                  | 11875                 | 4235                  | 11332                 | 7267                  | 30675               | 6901                | 96853  | 3             | 4                          | <b>7</b>                                |
+|                                                                         | 19639                 | 18593                 | 4899                  | 7049                  | 22145                 | 27513                 | 16847                 | 13254               | 3012                | 132951 | 1             | 7                          | <b>8</b>                                |
+|                                                                         | 3501                  | 10905                 | 19127                 | 28865                 | 15857                 | 16708                 | 702                   | 6495                | 8023                | 110183 | 3             | 9                          | <b>2</b>                                |
+|                                                                         | 14252                 | 30079                 | 31602                 | 14318                 | 10575                 | 22882                 | 29312                 | 29710               | 4693                | 187423 | 3             | 3                          | <b>6</b>                                |
+|                                                                         | 28050                 | 7510                  | 90                    | 30210                 | 13411                 | 30157                 | 19899                 | 30454               | 24778               | 184559 | 9             | 5                          | <b>4</b>                                |
+|                                                                         | 3415                  | 8314                  | 12117                 | 267                   | 23127                 | 18687                 | 7295                  | 30433               | 8817                | 112472 | 2             | 7                          | <b>9</b>                                |
+|                                                                         | 31130                 | 10165                 | 31857                 | 24788                 | 8396                  | 25475                 | 18646                 | 17077               | 27502               | 195036 | 6             | 0                          | <b>6</b>                                |
+|                                                                         | 10822                 | 8483                  | 18330                 | 15175                 | 20140                 | 16641                 | 13643                 | 8804                | 3370                | 115408 | 8             | 0                          | <b>8</b>                                |
+| SSK <sub>x</sub> = 638378264968                                         |                       |                       |                       |                       |                       |                       |                       |                     |                     |        |               |                            |                                         |
+| X sends RCN <sub>y</sub> , ESSK <sub>x</sub> and RNK <sub>x</sub> to Y. |                       |                       |                       |                       |                       |                       |                       |                     |                     |        |               |                            |                                         |
+
+#### C.6.5.4 Calculations at Y to recover SK<sub>x</sub>
+
+Y
+
+> UIN<sub>y</sub>, UCN<sub>y</sub> <
+
+>>>>>> RCN<sub>y</sub>, RNK<sub>x</sub>, ESSK<sub>x</sub>
+
+MP<sub>x</sub> = (UIN<sub>y</sub>, UCN<sub>y</sub> & ID<sub>x</sub> & ID<sub>y</sub>){HKM-1}[RCN<sub>y</sub>]
+
+SK<sub>x</sub> = (MP<sub>x</sub> & RNK<sub>x</sub>){HKMD-1}[ESSK<sub>x</sub>]
+
+##### C.6.5.4.1 Calculations at Y to recover MP<sub>x</sub>, from RCN<sub>y</sub>
+
+MP<sub>x</sub> = (UIN<sub>y</sub>, UCN<sub>y</sub> & ID<sub>x</sub> & ID<sub>y</sub>){HKM-1}[RCN<sub>y</sub>]
+
+The test values and calculations are identical to those shown in C.6.4.5, except that the decryption process HKM-1 is used to recover MP<sub>x</sub> from RCN<sub>y</sub> by subtracting the 16-digit PRS digit-by-digit from RCN<sub>y</sub>.
+
+The results of these calculations using the test values are shown below.
+
+UINy = 973557693837783148353709167436722873449819767357
+
+UCNy = 7598247578649467
+
+Primitive = 9735576938377831483537091674367228734498197673577598247578649467
+
+P(0) 9735 + 0 \* 101 = 9735
+
+B(0) 2873 + 0 \* 79 = 2873
+
+P(1) 5769 + 1 \* 101 = 5870
+
+B(1) 4498 + 1 \* 79 = 4577
+
+P(2) 3837 + 2 \* 101 = 4039
+
+B(2) 1976 + 2 \* 79 = 2134
+
+P(3) 7831 + 3 \* 101 = 8134
+
+B(3) 7357 + 3 \* 79 = 7594
+
+P(4) 4835 + 4 \* 101 = 5239
+
+B(4) 7598 + 4 \* 79 = 7914
+
+P(5) 3709 + 5 \* 101 = 4214
+
+B(5) 2475 + 5 \* 79 = 2870
+
+P(6) 1674 + 6 \* 101 = 2280
+
+B(6) 7864 + 6 \* 79 = 8338
+
+P(7) 36 + 7 \* 101 = 743
+
+B(7) 94 + 7 \* 79 = 647
+
+P(8) 72 + 8 \* 101 = 880
+
+B(8) 67 + 8 \* 79 = 699
+
+P(0) to P(3), and B(0) to B(3) are modified as before using IDx and IDy.
+
+IDx = 642092 IDy = 538249
+
+P(0) = 9735 + 642 = 10377
+
+B(0) = 2873 + 642 = 3515
+
+P(1) = 5870 + 092 = 5962
+
+B(1) = 4577 + 092 = 4669
+
+P(2) = 4039 + 538 = 4577
+
+B(2) = 2134 + 538 = 2672
+
+P(3) = 8134 + 249 = 8383
+
+B(3) = 7594 + 249 = 7843
+
+The results of using these phase and base primitive values with the 9 primes in the HKM–1 algorithm to produce MPx, 43149205748688366, from RCNy, 9865418902725854, are shown in Table C.7.
+
+**Table C.7/T.36 – Calculations at Y to recover MPx from RCNy**
+
+| Prime<br>B(n)<br>P(n)                                           | 32603<br>3515<br>10377 | 32507<br>4669<br>5962 | 32183<br>2672<br>4577 | 32003<br>7843<br>8383 | 31847<br>7914<br>5239 | 31607<br>2870<br>4214 | 31583<br>8338<br>2280 | 31547<br>647<br>743 | 31259<br>699<br>880 | Total  | Last<br>digit | Registered<br>Crypt<br>Number | Mutual<br>Primitive |
+|-----------------------------------------------------------------|------------------------|-----------------------|-----------------------|-----------------------|-----------------------|-----------------------|-----------------------|---------------------|---------------------|--------|---------------|-------------------------------|---------------------|
+|                                                                 | 25001                  | 10586                 | 204                   | 13707                 | 28499                 | 20306                 | 29257                 | 7516                | 21199               | 156275 | 5             | 9                             | 4                   |
+|                                                                 | 13430                  | 15394                 | 30160                 | 5924                  | 632                   | 26519                 | 29357                 | 4614                | 1335                | 127365 | 5             | 8                             | 3                   |
+|                                                                 | 29909                  | 1609                  | 1288                  | 25579                 | 1669                  | 31481                 | 10416                 | 19840               | 26654               | 148445 | 5             | 6                             | 1                   |
+|                                                                 | 18063                  | 3304                  | 30138                 | 21293                 | 23808                 | 17664                 | 26941                 | 28398               | 782                 | 170391 | 1             | 5                             | 4                   |
+|                                                                 | 13404                  | 18058                 | 6870                  | 9345                  | 9660                  | 29659                 | 15762                 | 13152               | 15215               | 131125 | 5             | 4                             | 9                   |
+|                                                                 | 3725                   | 22151                 | 12330                 | 5965                  | 16440                 | 3679                  | 6693                  | 23201               | 7225                | 101409 | 9             | 1                             | 2                   |
+|                                                                 | 19572                  | 18252                 | 22551                 | 27112                 | 11165                 | 1992                  | 30656                 | 26222               | 17576               | 175098 | 8             | 8                             | 0                   |
+|                                                                 | 3250                   | 17741                 | 9696                  | 11484                 | 16232                 | 27780                 | 8509                  | 24895               | 837                 | 120424 | 4             | 9                             | 5                   |
+|                                                                 | 12700                  | 4893                  | 397                   | 12570                 | 21097                 | 15746                 | 12624                 | 18095               | 22401               | 120523 | 3             | 0                             | 7                   |
+|                                                                 | 6993                   | 25503                 | 30928                 | 17270                 | 19684                 | 24617                 | 24356                 | 3528                | 28799               | 181678 | 8             | 2                             | 4                   |
+|                                                                 | 30336                  | 366                   | 25855                 | 11914                 | 15499                 | 9145                  | 1638                  | 11232               | 30964               | 136949 | 9             | 7                             | 8                   |
+|                                                                 | 19230                  | 18490                 | 19842                 | 24745                 | 16289                 | 12340                 | 13788                 | 11294               | 12608               | 148626 | 6             | 2                             | 6                   |
+|                                                                 | 7431                   | 23725                 | 12423                 | 8843                  | 26337                 | 15960                 | 2224                  | 19861               | 29213               | 146017 | 7             | 5                             | 8                   |
+|                                                                 | 4962                   | 20676                 | 13583                 | 5148                  | 24250                 | 6657                  | 4491                  | 10438               | 7760                | 97965  | 5             | 8                             | 3                   |
+|                                                                 | 31428                  | 22961                 | 23535                 | 19981                 | 4478                  | 14962                 | 20103                 | 2328                | 16433               | 156209 | 9             | 5                             | 6                   |
+|                                                                 | 10456                  | 29330                 | 32121                 | 24295                 | 25028                 | 18634                 | 7833                  | 23507               | 14614               | 185818 | 8             | 4                             | 6                   |
+| MPx = (UINy, UCNy & IDx & IDy){HKM–1}[RCNy] = 43149205748688366 |                        |                       |                       |                       |                       |                       |                       |                     |                     |        |               |                               |                     |
+
+##### C.6.5.4.2 Calculations at Y to recover SKx, from ESSKx, using HKMD–1
+
+$SKx = (MPx \& RNKx)\{HKMD-1\}[ESSKx]$
+
+ESSKx is doubly decrypted using HKMD–1 in the reverse order to the double encryption carried out at X. The first decryption is the (mod 10) subtraction from the 'message' (ESSKx) of the same (mod 10) PRS as used by X. The second decryption is a descrambling process based on the same 12-digit PRS (mod 10) + 1 as used by X.
+
+###### C.6.5.4.2.1 Calculations at Y for the first decryption of ESSK<sub>x</sub>, to recover SSK<sub>x</sub>
+
+The same calculations using HKM, as in C.6.5.3.2, are used to generate a 12-digit (mod 10) PRS, which is subtracted (mod 10) from ESSK<sub>x</sub>, to produce SSK<sub>x</sub>.
+
+MP<sub>x</sub>, is repeated and concatenated to form the 64-digit Primitive which is used to derive phase and base primitive values as shown below.
+
+Primitive = 4314920574868366 4314920574868366 4314920574868366 4314920574868366
+
+$$P(0) \quad 4314 + (0 * 101) = 4314$$
+
+$$B(0) \quad 4314 + (0 * 79) = 4314$$
+
+$$P(1) \quad 9205 + (1 * 101) = 9306$$
+
+$$B(1) \quad 9205 + (1 * 79) = 9284$$
+
+$$P(2) \quad 7486 + (2 * 101) = 7688$$
+
+$$B(2) \quad 7486 + (2 * 79) = 7644$$
+
+$$P(3) \quad 8366 + (3 * 101) = 8669$$
+
+$$B(3) \quad 8366 + (3 * 79) = 8603$$
+
+$$P(4) \quad 4314 + (4 * 101) = 4718$$
+
+$$B(4) \quad 4314 + (4 * 79) = 4630$$
+
+$$P(5) \quad 9205 + (5 * 101) = 9710$$
+
+$$B(5) \quad 9205 + (5 * 79) = 9600$$
+
+$$P(6) \quad 7486 + (6 * 101) = 8092$$
+
+$$B(6) \quad 7486 + (6 * 79) = 7960$$
+
+$$P(7) \quad 83 + (7 * 101) = 790$$
+
+$$B(7) \quad 83 + (7 * 79) = 636$$
+
+$$P(8) \quad 66 + (8 * 101) = 874$$
+
+$$B(8) \quad 66 + (8 * 79) = 698$$
+
+RNK<sub>x</sub>, associated with ESSK<sub>x</sub>, is divided into 2 pairs of 2-digits and the first pair is added to P(0) and the second pair to P(1) to give new values of P(0) and P(1); new values for B(0) and B(1) are created in an identical manner.
+
+RNK<sub>x</sub> = 3958
+
+$$P(0) = 4314 + 39 = 4353$$
+
+$$B(0) = 4314 + 39 = 4353$$
+
+$$P(1) = 9306 + 58 = 9364$$
+
+$$B(1) = 9284 + 58 = 9342$$
+
+The results of the calculations to decrypt ESSK<sub>x</sub>, 638378264968, to form SSK<sub>x</sub>, 721647935700, are given in Table C.8.
+
+**Table C.8/T.36 – Calculations at Y to form SSK<sub>x</sub> from ESSK<sub>x</sub>**
+
+| Prime<br>B(n)<br>P(n)           | 32603<br>4353<br>4353 | 32507<br>9342<br>9364 | 32183<br>7644<br>7688 | 32003<br>8603<br>8669 | 31847<br>4630<br>4718 | 31607<br>9600<br>9710 | 31583<br>7960<br>8092 | 31547<br>636<br>790 | 31259<br>698<br>874 | Total  | Last<br>digit | Encrypted<br>Scrambled<br>Secret<br>Key | Scrambled<br>Secret<br>Key |
+|---------------------------------|-----------------------|-----------------------|-----------------------|-----------------------|-----------------------|-----------------------|-----------------------|---------------------|---------------------|--------|---------------|-----------------------------------------|----------------------------|
+|                                 | 6266                  | 2151                  | 914                   | 12417                 | 29145                 | 6957                  | 14583                 | 29235               | 16131               | 117799 | 9             | 6                                       | 7                          |
+|                                 | 19790                 | 5316                  | 2905                  | 29440                 | 5611                  | 1609                  | 13165                 | 12277               | 6198                | 96301  | 1             | 3                                       | 2                          |
+|                                 | 8744                  | 23883                 | 31733                 | 578                   | 23625                 | 22184                 | 16155                 | 16063               | 12462               | 155427 | 7             | 8                                       | 1                          |
+|                                 | 14931                 | 19445                 | 3781                  | 12069                 | 21152                 | 30041                 | 19407                 | 26387               | 8474                | 155687 | 7             | 3                                       | 6                          |
+|                                 | 16864                 | 6074                  | 1630                  | 11875                 | 4235                  | 11332                 | 7267                  | 30675               | 6901                | 96853  | 3             | 7                                       | 4                          |
+|                                 | 19639                 | 18593                 | 4899                  | 7049                  | 22145                 | 27513                 | 16847                 | 13254               | 3012                | 132951 | 1             | 8                                       | 7                          |
+|                                 | 3501                  | 10905                 | 19127                 | 28865                 | 15857                 | 16708                 | 702                   | 6495                | 8023                | 110183 | 3             | 2                                       | 9                          |
+|                                 | 14252                 | 30079                 | 31602                 | 14318                 | 10575                 | 22882                 | 29312                 | 29710               | 4693                | 187423 | 3             | 6                                       | 3                          |
+|                                 | 28050                 | 7510                  | 90                    | 30210                 | 13411                 | 30157                 | 19899                 | 30454               | 24778               | 184559 | 9             | 4                                       | 5                          |
+|                                 | 3415                  | 8314                  | 12117                 | 267                   | 23127                 | 18687                 | 7295                  | 30433               | 8817                | 112472 | 2             | 9                                       | 7                          |
+|                                 | 31130                 | 10165                 | 31857                 | 24788                 | 8396                  | 25475                 | 18646                 | 17077               | 27502               | 195036 | 6             | 6                                       | 0                          |
+|                                 | 10822                 | 8483                  | 18330                 | 15175                 | 20140                 | 16641                 | 13643                 | 8804                | 3370                | 115408 | 8             | 8                                       | 0                          |
+| SSK <sub>x</sub> = 721647935700 |                       |                       |                       |                       |                       |                       |                       |                     |                     |        |               |                                         |                            |
+
+###### C.6.5.4.2.2 Calculations at Y to derive SK<sub>x</sub> from SSK<sub>x</sub>
+
+The same calculations that were used at X to produce the (mod 12) + 1 PRS (see C.6.5.3.1) are used at Y to produce the same scrambler/descrambler PRS, 8 2 4 12 2 4 12 8 12 9 1 5. This scrambler/descrambler PRS is reversed and used as the descrambler PRS to descramble SSK<sub>x</sub>.
+
+The descrambler PRS is 5 1 9 12 8 12 4 2 12 4 2 8.
+
+The first digit in the descrambler PRS indicates which digit in SSK<sub>x</sub> should be interchanged with the twelfth digit of the SSK<sub>x</sub>. The second digit in the descrambler PRS indicates the interchange for the eleventh digit of the SSK<sub>x</sub> and so on for the remaining digits. The steps of this descrambling process to produce SK<sub>x</sub>, 309126704577, from the SSK<sub>x</sub>, 721647935700, are shown below.
+
+###### Descrambler PRS
+
+|    |                                                  |
+|----|--------------------------------------------------|
+| 5  | 7216 <u>4</u> 793570 <u>0</u> = SSK <sub>x</sub> |
+| 1  | <u>7</u> 216079357 <u>0</u> 4                    |
+| 9  | 02160793 <u>5</u> 774                            |
+| 12 | 02160793 <u>7</u> 57 <u>4</u>                    |
+| 8  | 0216079 <u>3</u> 4577                            |
+| 12 | 021607 <u>9</u> 3457 <u>7</u>                    |
+| 4  | 021 <u>6</u> 07734579                            |
+| 2  | 0 <u>2</u> 1706734579                            |
+| 12 | 001 <u>7</u> 2673457 <u>9</u>                    |
+| 4  | 00 <u>1</u> 926734577                            |
+| 2  | 00 <u>9</u> 126734577                            |
+| 8  | <u>0</u> 091267 <u>3</u> 4577                    |
+
+**309126704577 = SK<sub>x</sub>**
+
+Both X and Y are now in possession of the same SK<sub>x</sub>.
+
+### C.6.6 The use of the HKM algorithm in secure mode
+
+The HKM algorithm is used in the secure mode to re-create MP<sub>x</sub> and MP<sub>y</sub> at X and Y and using procSTK<sub>xy</sub> and procSTK<sub>yx</sub> to securely transfer secret keys to provide mutual authentication, secret session key establishment for message confidentiality and /or message integrity, confirmation of receipt and confirmation or denial of integrity.
+
+The procedures to achieve these capabilities are described in C.5.
+
+# Annex D
+
+## Procedures for the use of the HFX40 carrier cipher to provide message confidentiality for secure document facsimile transmission
+
+## D.1 Scope
+
+This Annex defines the HFX40 carrier cipher system to be used with facsimile terminals to provide message confidentiality. Example calculations using test values are given in D.3. The calculations can be used to verify the implementation of this Annex.
+
+The HFX40 carrier cipher is intended to be applicable for use with all types of dedicated facsimile terminals but is also equally applicable to computer-based facsimile systems.
+
+The HFX40 system is based upon the use of 19 system prime numbers. These same 19 prime numbers are used also with the HKM key management system which is defined in Annex C and the message integrity hash algorithm which is described in Annex E. However, this Annex does not cover the key management system, nor the main message integrity hash algorithm.
+
+Example calculations are given in D.3 and these can be used to verify the implementation of this Annex.
+
+The HFX40 system is covered by intellectual property rights; however, the owner of those rights has agreed to follow the TSB code of practice. Further details can be obtained from the TSB.
+
+## **D.2 Description of the HFX40 algorithm for use with facsimile terminals in secure mode**
+
+The HFX40 algorithm is used to provide message confidentiality using encryption. The algorithm uses a secret key to provide the input numbers for modular arithmetical calculations. The moduli for the modular arithmetic are provided by a selection of 3 primes made from a set of 19 system modulating prime numbers stored in the facsimile terminal. This set of prime numbers is the same as that used by the HKM key management system (Annex C) and the HFX40-I message integrity system (Annex E).
+
+The output of the modular arithmetical processes are long PRSs that are used to encrypt the compressed facsimile message. Only by possessing the secret encryption key is it possible to recreate the message.
+
+The HFX40 algorithm uses a 12-decimal digit key, approximately equivalent to a key length of 40 bits.
+
+The key management procedures are detailed in Annex C.
+
+If mutual registration has been carried out between X and Y, the secure mode can be used to establish mutual authentication of X and Y, following which SSx can be generated at X and transferred securely to Y. If registration has not been carried out, the override mode (see Recommendation T.30) can be used to allow the users at X and Y to manually enter a pre-agreed secret session key to form SSx.
+
+X uses SSx with the HFX40 algorithm to generate three (mod 2) PRSs which are stored as entries in 3 tables, referred to as tables P, Q and R. The number of entries in each table is different. Table P is generated with 1021 entries, table Q with 1019 entries and table R with 1013 entries.
+
+The last 4 entries in each table are used to form a multiplexer to modify the table entries as the message is encrypted and the shortened tables are used to encrypt the message. Table P is now 1017 entries, table Q is 1015 entries and table R is 1009 entries
+
+The first bit of the compressed facsimile message is added (mod 2) to the addition (mod 2) of the bits in the first entries of the tables P, Q and R to form the first bit of the encrypted message. After each message bit has been processed, the corresponding P, Q and R table entries are modified based upon the entries in the multiplexer. The modification in each table is an interchange of the table entry with an entry in the multiplexer which is determined by the entries in the other two tables.
+
+The entry in table P interchanges with the multiplexer entry determined by tables Q and R.
+
+The entry in table Q interchanges with the multiplexer entry determined by tables R and P.
+
+The entry in table R interchanges with the multiplexer entry determined by tables P and Q.
+
+Note, the order has significance.
+
+The second bit of the main message is processed in a similar way with the bits in the second entries in the tables. The new multiplexer formed by the interchange of the first entries in the tables is then used to interchange with the second entries in the tables.
+
+The above procedure is followed for each of the message bits. When in table R entry 1009 has been used, the first (modified) entry is the next to be used. The procedure then continues with the new entries. Similarly, tables P and Q "restart" after entries 1017 and 1015 respectively.
+
+The encrypted message is then sent to Y. Y uses the same SSx with the HFX40 algorithm to generate the identical tables and modifying multiplexer; subtracting the (mod 2) addition of the entries in the tables from the encrypted message to recover the original compressed facsimile message. The SSx used by Y is either transferred securely from X in the secure mode or is formed from the pre-agreed session key entered manually by the user at Y in the override mode.
+
+## **D.3 Example calculations for the HFX40 algorithm**
+
+### **D.3.1 Introduction**
+
+This subclause describes the HFX40 algorithm in terms of the numbers to be stored and the rules for the computations carried out using these numbers to generate the PRSs which are used to encrypt the compressed facsimile message. The calculations can be used to verify the implementation.
+
+### D.3.2 Stored information
+
+All terminals are equipped with the same 19 system modulating prime numbers.
+
+|       |       |       |       |       |       |       |       |       |       |
+|-------|-------|-------|-------|-------|-------|-------|-------|-------|-------|
+| 32603 | 32507 | 32183 | 32003 | 31847 | 31607 | 31583 | 31547 | 31259 |       |
+| 31139 | 30803 | 30539 | 30467 | 30347 | 30323 | 30203 | 29879 | 29759 | 29663 |
+
+### D.3.3 Selection of the primes
+
+For each facsimile call, a different SSx is used to select 3 primes from the 19 stored system modulating primes. SSx is split into four groups of 3 digits. The first 2 groups of three digits, g1 and g2, are XOR'd to form a third group g3. The second 2 groups of 3 digits, g4 and g5, are XOR'd to form a sixth group, g6. 1024 is added to groups g1 to g3 to form P(0) to P(2) and to groups g4 to g6 to form B(0) to B(2). This procedure is shown below using a numerical example.
+
+SSx for this example is 149162536496.
+
+|                       |                           |
+|-----------------------|---------------------------|
+| g1 = 149              | P(0) = 149 + 1024 = 1173  |
+| g2 = 162              | P(1) = 162 + 1024 = 1186  |
+| g3 = g1 XOR g2 = 55   | P(2) = 55 + 1024 = 1079   |
+| g4 = 536              | B(0) = 536 + 1024 = 1560  |
+| g5 = 496              | B(1) = 496 + 1024 = 1520  |
+| g6 = g4 XOR g5 = 1000 | B(2) = 1000 + 1024 = 2024 |
+
+Three 8 digit numbers are then formed by concatenating the pairs P(0) and B(0), P(1) and B(1), and P(2) and B(2) together and modulating each number to the base 19.
+
+|               |       |                        |
+|---------------|-------|------------------------|
+| P(0) and B(0) | gives | 11731560 (mod 19) = 10 |
+| P(1) and B(1) | gives | 11861520 (mod 19) = 10 |
+| P(2) and B(2) | gives | 10792024 (mod 19) = 5  |
+
+In the list of the 19 system modulating prime numbers given in D.3.2 above, the first prime, 32603, is designated prime (0) and the last prime, 29663, prime (18).
+
+Using the first value, 10, obtained from P(0) and B(0), the first prime, i.e. prime (0), 32603 is interchanged with prime (10), 30803.
+
+Using the second value, 10, obtained from P(1) and B(1), the second prime i.e. prime (1), 32507 is interchanged with prime (10), 32603.
+
+Using the third value, 5, obtained from P(2) and B(2), the third prime i.e. prime (2), 32183 is exchanged with prime (5), 31607.
+
+This process is shown below:
+
+|                   |                     |                     |                     |       |       |                     |       |       |       |       |
+|-------------------|---------------------|---------------------|---------------------|-------|-------|---------------------|-------|-------|-------|-------|
+| Unmodified system | 32603               | 32507               | 32183               | 32003 | 31847 | 31607               | 31583 | 31547 | 31259 |       |
+| modulating primes | 31139               | 30803               | 30539               | 30467 | 30347 | 30323               | 30203 | 29879 | 29759 | 29663 |
+| <b>10</b>         | <u><b>30803</b></u> | 32507               | 32183               | 32003 | 31847 | 31607               | 31583 | 31547 | 31259 |       |
+|                   | 31139               | <u><b>32603</b></u> | 30539               | 30467 | 30347 | 30323               | 30203 | 29879 | 29759 | 29663 |
+| <b>10</b>         | 30803               | <u><b>32603</b></u> | 32183               | 32003 | 31847 | 31607               | 31583 | 31547 | 31259 |       |
+|                   | 31139               | <u><b>32507</b></u> | 30539               | 30467 | 30347 | 30323               | 30203 | 29879 | 29759 | 29663 |
+| <b>5</b>          | 30803               | 32603               | <u><b>31607</b></u> | 32003 | 31847 | <u><b>32183</b></u> | 31583 | 31547 | 31259 |       |
+|                   | 31139               | 32507               | 30539               | 30467 | 30347 | 30323               | 30203 | 29879 | 29759 | 29663 |
+
+### D.3.4 Calculations using HFX40 to generate 3 PRSs
+
+The first three primes in the final arrangement, 30803, 32603 and 31607, are used as the moduli for calculations carried out with the 3 phase and 3 base primitive values derived from SSx in D.3.3 to generate three (mod 2) PRSs to be stored in tables P, Q and R. Table P to have 1021 entries, table Q, 1019 entries and table R, 1013 entries.
+
+Example calculations for the first "set", i.e. prime (0) = 30803, phase P(0) = 1173 and base B(0) = 1560:
+
+P(0) is multiplied by B(0):
+
+$$1173 * 1560 = 1829880$$
+
+$$1829880 \text{ [mod prime (0)]} = 1829880 \text{ (mod 30803)} = 12503$$
+
+$$12503 \text{ (mod 2)} = 1$$
+
+12503 is then used as the new phase value and is multiplied by B(0):
+
+$$12503 * 1560 = 19504680$$
+
+$$19504680 \text{ [mod prime (0)]} = 19504680 \text{ (mod 30803)} = 6381$$
+
+$$6381 \text{ (mod 2)} = 1$$
+
+The process is repeated to generate 1021 values to fill the entries in table P.
+
+Similar calculations are carried out with the second and third "sets" of phases, bases and primes to generate entries for tables Q and R. Table D.1 shows 16 further sets of calculations using HFX40.
+
+**Table D.1/T.36– Calculations using HFX40 to generate 3 PRSs**
+
+| Phase | B(0) | New phase<br>(mod<br>30803) | Table P<br>(mod 2) | Phase | B(0) | New phase<br>(mod<br>32603) | Table Q<br>(mod 2) | Phase | *B(0) | New phase<br>(mod<br>31607) | Table R<br>(mod 2) |
+|-------|------|-----------------------------|--------------------|-------|------|-----------------------------|--------------------|-------|-------|-----------------------------|--------------------|
+| 1173  | 1560 | 12503                       | 1                  | 1186  | 1520 | 9555                        | 1                  | 1079  | 2024  | 3013                        | 1                  |
+| 12503 | 1560 | 6381                        | 1                  | 9555  | 1520 | 15265                       | 1                  | 3013  | 2024  | 29768                       | 0                  |
+| 6381  | 1560 | 4991                        | 1                  | 15265 | 1520 | 22067                       | 1                  | 29768 | 2024  | 7490                        | 0                  |
+| 4991  | 1560 | 23604                       | 0                  | 22067 | 1520 | 25956                       | 0                  | 7490  | 2024  | 20007                       | 1                  |
+| 23604 | 1560 | 12655                       | 1                  | 25956 | 1520 | 3490                        | 0                  | 20007 | 2024  | 5601                        | 1                  |
+| 12655 | 1560 | 27780                       | 0                  | 3490  | 1520 | 23114                       | 0                  | 5601  | 2024  | 21118                       | 0                  |
+| 27780 | 1560 | 29767                       | 1                  | 23114 | 1520 | 19849                       | 1                  | 21118 | 2024  | 10168                       | 0                  |
+| 29767 | 1560 | 16399                       | 1                  | 19849 | 1520 | 12705                       | 1                  | 10168 | 2024  | 3875                        | 1                  |
+| 16399 | 1560 | 15950                       | 0                  | 12705 | 1520 | 10624                       | 0                  | 3875  | 2024  | 4464                        | 0                  |
+| 15950 | 1560 | 23979                       | 1                  | 10624 | 1520 | 9995                        | 1                  | 4464  | 2024  | 27141                       | 1                  |
+| 23979 | 1560 | 12398                       | 0                  | 9995  | 1520 | 32005                       | 1                  | 27141 | 2024  | 418                         | 0                  |
+| 12398 | 1560 | 27399                       | 1                  | 32005 | 1520 | 3924                        | 0                  | 418   | 2024  | 24250                       | 0                  |
+| 27399 | 1560 | 18679                       | 1                  | 3924  | 1520 | 30734                       | 0                  | 24250 | 2024  | 27936                       | 0                  |
+| 18679 | 1560 | 30405                       | 1                  | 30734 | 1520 | 28184                       | 0                  | 27936 | 2024  | 29148                       | 0                  |
+| 30405 | 1560 | 25983                       | 1                  | 28184 | 1520 | 31941                       | 1                  | 29148 | 2024  | 16890                       | 0                  |
+| 25983 | 1560 | 27535                       | 1                  | 31941 | 1520 | 4453                        | 1                  | 16890 | 2024  | 18193                       | 1                  |
+| :     | :    | :                           | :                  | :     | :    | :                           | :                  | :     | :     | :                           | :                  |
+| :     | :    | :                           | :                  | :     | :    | :                           | :                  | :     | :     | :                           | :                  |
+
+Table D.2 shows the complete P, Q and R tables.
+
+The last 4 entries of each table are used to form the initial entries in a multiplexer which is used with a "truth table" to modify the P, Q and R table entries as the message is encrypted.
+
+| <u>Multiplexer</u> |          |          | <u>"Truth table"</u> |   |
+|--------------------|----------|----------|----------------------|---|
+| <u>P</u>           | <u>Q</u> | <u>R</u> |                      |   |
+| 1                  | 1        | 1        | 0                    | 0 |
+| 1                  | 1        | 1        | 0                    | 1 |
+| 1                  | 1        | 1        | 1                    | 0 |
+| 0                  | 1        | 1        | 1                    | 1 |
+
+The shortened tables, table P is now 1017 entries, table Q is 1015 entries and table R is 1009 entries, are used to encrypt the message as explained below.
+
+### D.3.5 Use of the tables to encrypt the message and of the multiplexer to modify the tables
+
+The first bit of the main message is added (mod 2) to the (mod 2) addition of the first entries in each of the shortened tables P, Q and R to form the first bit of the encrypted message. The second bit of the main message is processed in the same way with the second entries in the tables and so on. After each message bit has been processed, the corresponding P, Q and R table entries are modified based upon the entries in the multiplexer. The modification in each table is an interchange of the table entry with an entry in the multiplexer which is determined by the entries in the other two tables.
+
+**Table D.2/T.36 – The complete P, Q and R tables**
+
+|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
+|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| <p><b>Table P (1021 entries)</b></p> <p>111010110101111100010100011100100101101100010100111111000000000100110111000011011000011101111<br/> 1101101100000111100001111011010111010110100100010011011010010110001000000101000010010111010101<br/> 1100001001010010011000010011100010010111100010111100110000000110101111111111001111010001111111<br/> 1000110110010111110101001001101101111100001111010111011011110100011000001011010100011010011111<br/> 00010111110100111110110001100111110100010101001000101001100110011001000110011001110110000<br/> 1011000111001110010001011110111011010000000100001010101010111011010010001000000011010011110100<br/> 011000000000000100011001101110110100100000011010111000000011101000010011100100101100011101111<br/> 1010101001111111001111110010000110001000111000001011110001101101101110010011110001110111100<br/> 001011100110010010111011100101011100100110101100010010110100001100011000000000110001010111010<br/> 1111011101000111000000001010000101010000000111001111111111101110110010111000110101001000110<br/> 1001111010101000000010101110000111100101010100001001011111111000000001101111 1110</p>                 |
+| <p><b>Table Q (1019 entries)</b></p> <p>11100011011000111101000001100111011000011100111111100000101011110000111111000101111100001111<br/> 1101011111100101101111111110011101101101001111000101011000101001101101100000110100100110101010<br/> 011110000100111110101111001001000111110110101111010011011100010011101100000011011001101110001<br/> 101110100010101011010011001001110000101111001000011110110110001000010011010111001000010110100<br/> 0000000000000101001111001000111001011111001000010111001011111001111101101010000010101<br/> 0111110111011001110011011110111101001100100011000110101000101011001000101000110111100000000001<br/> 0111100101101011010110001110111100111101100010110011001100011101101010101001011110100011000010<br/> 010110100011101001011110010001111110001110000111111001010111110011100011100011100101110000<br/> 10010000101100111111110000100010100010110011000101000100010011100111010010011001010000<br/> 0010011100101011001101001101010100101001110110100000010000100101000100101110111011011000010<br/> 00011100010101110111101100111011001001110111011000100011101100011101011100 1111</p>                                 |
+| <p><b>Table R (1013 entries)</b></p> <p>1001100101000001101111100011010101110101000110100101001100110001101100011010111000001100001100<br/> 0111000111101000010100100110100111100000000101001100011011010011000001001001000010111101001101<br/> 110100101011010011111010111101110000000011010111111101111100010111000000110011010100001011010<br/> 111000010111010110010110101110101010011110100111011011100000111101111010101000111100000111111<br/> 101000110110110011101101111111000100000011101101001010001010011100101100110001110000000101111<br/> 0110010010100000100111010000100000110010011001011101011011001100100011110100000001000011110001<br/> 0011101110101011000110001110110001100101100100110100010001001100010111001111011111001111011101<br/> 1100101110001101000001011100110010111000000000001001101010110111001111101110010011000011111011<br/> 1001111000111000110111001010101000100101101100011000111001101010000100001111000001100101101010<br/> 000000100110000000111011111101110001111011111000111010100010100100110001111011010011010011010<br/> 1001001101101101100010101101011110000011110000110101011100010001100011001100110100 1111</p> |
+
+After a set of entries in the P, Q and R tables has been used to encrypt a bit of the message:
+
+- the table P entry is interchanged with the multiplexer entry determined by the entries in tables Q and R;
+- the table Q entry is interchanged with the multiplexer entry determined by the entries in tables R and P;
+- the table R entry is interchanged with the multiplexer entry determined by the entries in tables P and Q.
+
+Note, the order has significance.
+
+The following example using the first 7 entries from tables P, Q and R shows in detail how the procedure is carried out.
+
+The first 7 entries in the initial P, Q and R tables are:
+
+| <u>P</u> | <u>Q</u> | <u>R</u> |
+|----------|----------|----------|
+| 1        | 1        | 1        |
+| 1        | 1        | 0        |
+| 1        | 1        | 0        |
+| 0        | 0        | 1        |
+| 1        | 0        | 1        |
+| 0        | 0        | 0        |
+| 1        | 1        | 0        |
+
+The multiplexer initial entries and the truth table are:
+
+| <u>P</u> | <u>Q</u> | <u>R</u> | <u>Truth table</u> |   |
+|----------|----------|----------|--------------------|---|
+| 1        | 1        | 1        | 0                  | 0 |
+| 1        | 1        | 1        | 0                  | 1 |
+| 1        | 1        | 1        | 1                  | 0 |
+| 0        | 1        | 1        | 1                  | 1 |
+
+The first entries in tables P, Q and R are 1, 1 and 1 respectively. The first entry in table P is interchanged according to the first entries in tables Q and R, these are 1 and 1. From the "truth table", the first entry in table P is interchanged with the entry in the P column of the multiplexer which corresponds to (1, 1) in the "truth table", in this case a 0.
+
+The first entry in Q is interchanged with the entry in the Q column of the multiplexer corresponding to (1, 1), in this case a 1.
+
+Similarly the first entry in R is interchanged with the entry in the R column of the multiplexer corresponding to (1, 1), in this case a 1.
+
+The result of this is that the first entries in tables P, Q and R, i.e. 1, 1, 1, become 0, 1, 1 respectively. These entries will be used the next time the first entry in a table is used.
+
+The multiplexer entries after these interchanges are:
+
+| <u>P</u> | <u>Q</u> | <u>R</u> |
+|----------|----------|----------|
+| 1        | 1        | 1        |
+| 1        | 1        | 1        |
+| 1        | 1        | 1        |
+| 1        | 1        | 1        |
+
+The new multiplexer entries are then used with the second entries from tables P, Q and R in exactly the same way. The result of this is that the second entries in tables P, Q and R, 1, 1, 0 become 1, 1, 1 and the multiplexer becomes:
+
+| <u>P</u> | <u>Q</u> | <u>R</u> |
+|----------|----------|----------|
+| 1        | 1        | 1        |
+| 1        | 1        | 1        |
+| 1        | 1        | 1        |
+| 1        | 1        | 0        |
+
+Following the above procedure for the first 5 message bits using the first 5 entries in tables P, Q and R gives the following results:
+
+| <u>Entry</u> | <u>Initial tables</u> |          |          | <u>Tables after encrypting 5 message bits</u> |          |          |
+|--------------|-----------------------|----------|----------|-----------------------------------------------|----------|----------|
+|              | <u>P</u>              | <u>Q</u> | <u>R</u> | <u>P</u>                                      | <u>Q</u> | <u>R</u> |
+| 1            | 1                     | 1        | 1        | 0                                             | 1        | 1        |
+| 2            | 1                     | 1        | 0        | 1                                             | 1        | 1        |
+| 3            | 1                     | 1        | 0        | 1                                             | 1        | 0        |
+| 4            | 0                     | 0        | 1        | 1                                             | 1        | 1        |
+| 5            | 1                     | 0        | 1        | 0                                             | 1        | 1        |
+| 6            | 0                     | 0        | 0        | 0                                             | 0        | 0        |
+| 7            | 1                     | 1        | 0        | 1                                             | 1        | 0        |
+| :            | :                     | :        | :        | :                                             | :        | :        |
+| :            | :                     | :        | :        | :                                             | :        | :        |
+
+The multiplexer settings used to modify the tables after encrypting each of the first 5 message bits are:
+
+| After bit number:          | 1                          | 2                          | 3                          | 4                          | 5                          |
+|----------------------------|----------------------------|----------------------------|----------------------------|----------------------------|----------------------------|
+| (initial setting)          |                            |                            |                            |                            |                            |
+| <u>P</u> <u>Q</u> <u>R</u> | <u>P</u> <u>Q</u> <u>R</u> | <u>P</u> <u>Q</u> <u>R</u> | <u>P</u> <u>Q</u> <u>R</u> | <u>P</u> <u>Q</u> <u>R</u> | <u>P</u> <u>Q</u> <u>R</u> |
+| 1 1 1                      | 1 1 1                      | 1 1 1                      | 1 1 1                      | 1 1 1                      | 1 1 1                      |
+| 1 1 1                      | 1 1 1                      | 1 1 1                      | 1 1 1                      | 0 1 1                      | 1 1 1                      |
+| 1 1 1                      | 1 1 1                      | 1 1 1                      | 1 1 1                      | 1 0 1                      | 1 0 1                      |
+| 0 1 1                      | 1 1 1                      | 1 1 0                      | 1 1 0                      | 1 1 0                      | 1 0 0                      |
+
+The above procedure is followed for each of the message bits. After table R uses entry number 1009, it returns to entry number 1 (the top of the table) and continues the procedure with the table's new entries. Similarly tables Q and P, after bit numbers 1015 and 1017 respectively, "restart" at their new first entries. The procedure is continued until the complete message has been encrypted.
+
+The encrypted message is then sent to Y. Y uses the same SSx with the HFX40 algorithm to generate the identical tables and modifying multiplexer; subtracting the (mod 2) addition of the entries in the tables from the encrypted message to recover the original compressed facsimile message and modifying the tables using the multiplexer.
+
+# **Annex E**
+
+## **Procedures for the use of the HFX40-I hashing system to provide message integrity for secure document facsimile transmission**
+
+## **E.1 Scope**
+
+This Annex describes the HFX40-I hashing algorithm, in terms of its use, the necessary calculations and the information to be exchanged between the facsimile terminals to provide integrity for a transmitted facsimile message as either a selected or pre-programmed alternative to the encryption of the message.
+
+In order to provide message integrity, a hash function is used to map arbitrarily long messages into fixed length values. The hash function generated by the HFX40-I algorithm maps the compressed facsimile message to a sequence of decimal digits.
+
+A hash function is cryptographically strong if it is difficult to find any message that maps to a given hash value or any pair of messages that map to the same hash value. To protect against the possibility of this being achieved by a third party, the HFX40-I algorithm uses primitives derived from a secret key. The resultant hash value of the message is also doubly encrypted to prevent the possibility of a third party reversing the hash function to discover the original primitives.
+
+The HFX40-I hashing algorithm is based upon the use of 19 system prime numbers. These same 19 prime numbers are used also with the HKM key management system which is defined in Annex C and the message carrier cipher which is described in Annex E. However, this Annex does not cover the key management system nor the message carrier cipher.
+
+The secure exchange of the secret key follows the procedures detailed in Annex C.
+
+Example calculations are given in E.3 and E.4 and these can be used to verify the implementation of the algorithm.
+
+The HFX40-I system is covered by intellectual property rights; however, the owner of those rights has agreed to follow the TSB code of practice. Further details can be obtained from the TSB.
+
+## **E.2 Use of the HFX40-I hashing system**
+
+To send a message protected for integrity, the user at X establishes a call to Y with which mutual registration has been carried out (see Annex C). Following successful mutual authentication of X and Y (see Annex C), X generates SSx which is sent securely to Y, using the procedure for the secure transfer of a secret key (procSTKxy) defined in Annex C.
+
+X also uses SSx, to form the primitives for the hash function, HFX40-I. The primitives are used by HFX40-I for modular arithmetical calculations to operate on the compressed facsimile message byte by byte. The moduli for the modular arithmetic are provided by a set of 19 system modulating prime numbers stored in the facsimile terminal. The order in which the 19 prime numbers are used is derived from SSx. This set of prime numbers is the same as that used by the HKM key management system (Annex C) and the HFX40 carrier cipher algorithm (Annex D).
+
+The output of one sequence of modular calculations with one byte of the message is used as the input to the calculation for the next byte of the message, and so on until the complete message has been processed. The resulting PH is doubly encrypted by the session key. The first encryption is a one-way function which scrambles the 24 digits of PH to form
+
+SH. The second encryption uses a one-way variant of the HKM cipher to form ESH. X sends the compressed facsimile message and ESH to Y.
+
+Y recovers SSx using procSTKxy and using the HFX40-I algorithm calculates PH of the received compressed facsimile message. Y performs the same two encryptions of PH as X to form ESH. If ESH matches the value of ESH received from X, not only is the integrity of the message confirmed but the authentication of the sender is also assured. Any discrepancy between the calculated ESH and the received ESH is evidence of loss of integrity.
+
+To provide confirmation or denial of integrity to X, Y generates IMy. IMy is a 12-digit random number selected from the digits 2 to 9 in which one digit is randomly selected to be replaced with a 1 to indicate confirmation of integrity or a 0 to indicate denial. Y sends IMy securely to X using SSx and procSTKyx.
+
+Example responses:
+
+IMy = 257795199982 Integrity confirmed.
+
+IMy = 317736845378 Integrity confirmed.
+
+IMy = 738543680892 Integrity denied.
+
+IMy = 457745204639 Integrity denied.
+
+## E.3 The HFX40-I hashing system for use with facsimile terminals
+
+### E.3.1 Introduction
+
+This subclause describes the HFX40-I hashing system in terms of the numbers to be stored and the rules for the computations carried out using these numbers to generate PH, SH and ESH. The rules are best explained using numerical examples. The numerical examples also use test values to allow verification of the implementation.
+
+### E.3.2 Stored information
+
+All terminals are equipped with the same 19 system modulating prime numbers (also used in Annexes C and D).
+
+32603 32507 32183 32003 31847 31607 31583 31547 31259  
+31139 30803 30539 30467 30347 30323 30203 29879 29759 29663
+
+### E.3.3 Re-ordering of the system modulating prime numbers
+
+X uses SSx to derive three initial phase primitive values, P(0) to P(2) and three base primitive values, B(0) to B(2) to be used with the first three system modulating prime numbers, 32603, 32507 and 32183 to generate 19 entries in a (mod 19) PRS.
+
+SSx is split into six overlapping groups of three digits. The first group being formed of the first 3 digits, the second from the second, third and fourth digits and so on. The first group of three digits are XOR'd with the second, the result of this is XOR'd with the third and so on. Two is added to each of the resulting groups to prevent occurrences of an all zero result. The resulting values then are used as the initial phase and base primitive values, P(0) to P(2) and B(0) to B(2). Table E.1 shows an example for SSx = 568702123345.
+
+**Table E.1/T.36 – Generation of P(0) to P(2) and B(0) to B(2) to re-order the system modulating prime numbers**
+
+| SSx = 568702123345<br>The six groups are: 568, 870, 021, 123, 334 and 345 |     |     |        |       |                  |
+|---------------------------------------------------------------------------|-----|-----|--------|-------|------------------|
+| Group                                                                     |     |     | Result | Add 2 | Phase/Base value |
+| 568                                                                       |     |     | 568    | 570   | P(0)             |
+| 870                                                                       | XOR | 568 | 350    | 352   | P(1)             |
+| 021                                                                       | XOR | 350 | 331    | 333   | P(2)             |
+| 123                                                                       | XOR | 331 | 304    | 306   | B(0)             |
+| 334                                                                       | XOR | 304 | 126    | 128   | B(1)             |
+| 345                                                                       | XOR | 126 | 295    | 297   | B(2)             |
+
+The phase and base primitive values are then used with the first 3 system modulating prime numbers, 32603, 32507 and 32183, in the HKM algorithm to generate the first 19 values in a (mod 19) PRS. An example of the use of HKM with these test values is given in E.4.
+
+The (mod 19) PRS generated is:
+
+10, 14, 0, 12, 2, 14, 9, 6, 10, 1, 2, 9, 17, 6, 14, 5, 3, 15, 5
+
+The 19 system modulating prime numbers are transposed using the PRS to determine the order in which they are to be used in the HFX40-I hash algorithm. The first value in the PRS determines which "numbered" prime is interchanged with the prime in the first position, the second value, which "numbered" prime is interchanged with the prime in the second position, and so on. Table E.2 shows the 19 stages of transpositions against the PRS.
+
+**Table E.2/T.36 – Transposing system modulating prime numbers, "numbers" 0 to 18, using the (mod 19) PRS**
+
+| Step | PRS | Prime "number" (0 to 18) |           |           |           |           |           |           |          |          |           |           |           |           |          |          |          |           |          |           |
+|------|-----|--------------------------|-----------|-----------|-----------|-----------|-----------|-----------|----------|----------|-----------|-----------|-----------|-----------|----------|----------|----------|-----------|----------|-----------|
+|      |     | <u>0</u>                 | 1         | 2         | 3         | 4         | 5         | 6         | 7        | 8        | 9         | <u>10</u> | 11        | 12        | 13       | 14       | 15       | 16        | 17       | 18        |
+| 1    | 10  | <u>10</u>                | 1         | 2         | 3         | 4         | 5         | 6         | 7        | 8        | 9         | <u>0</u>  | 11        | 12        | 13       | 14       | 15       | 16        | 17       | 18        |
+| 2    | 14  | 10                       | <u>14</u> | 2         | 3         | 4         | 5         | 6         | 7        | 8        | 9         | 0         | 11        | 12        | 13       | <u>1</u> | 15       | 16        | 17       | 18        |
+| 3    | 0   | <u>2</u>                 | 14        | <u>10</u> | 3         | 4         | 5         | 6         | 7        | 8        | 9         | 0         | 11        | 12        | 13       | 1        | 15       | 16        | 17       | 18        |
+| 4    | 12  | 2                        | 14        | 10        | <u>12</u> | 4         | 5         | 6         | 7        | 8        | 9         | 0         | 11        | <u>3</u>  | 13       | 1        | 15       | 16        | 17       | 18        |
+| 5    | 2   | 2                        | 14        | <u>4</u>  | 12        | <u>10</u> | 5         | 6         | 7        | 8        | 9         | 0         | 11        | 3         | 13       | 1        | 15       | 16        | 17       | 18        |
+| 6    | 14  | 2                        | 14        | 4         | 12        | 10        | <u>1</u>  | 6         | 7        | 8        | 9         | 0         | 11        | 3         | 13       | <u>5</u> | 15       | 16        | 17       | 18        |
+| 7    | 9   | 2                        | 14        | 4         | 12        | 10        | 1         | <u>9</u>  | 7        | 8        | <u>6</u>  | 0         | 11        | 3         | 13       | 5        | 15       | 16        | 17       | 18        |
+| 8    | 6   | 2                        | 14        | 4         | 12        | 10        | 1         | <u>7</u>  | <u>9</u> | 8        | 6         | 0         | 11        | 3         | 13       | 5        | 15       | 16        | 17       | 18        |
+| 9    | 10  | 2                        | 14        | 4         | 12        | 10        | 1         | 7         | 9        | <u>0</u> | 6         | <u>8</u>  | 11        | 3         | 13       | 5        | 15       | 16        | 17       | 18        |
+| 10   | 1   | 2                        | <u>6</u>  | 4         | 12        | 10        | 1         | 7         | 9        | 0        | <u>14</u> | 8         | 11        | 3         | 13       | 5        | 15       | 16        | 17       | 18        |
+| 11   | 2   | 2                        | 6         | <u>8</u>  | 12        | 10        | 1         | 7         | 9        | 0        | 14        | <u>4</u>  | 11        | 3         | 13       | 5        | 15       | 16        | 17       | 18        |
+| 12   | 9   | 2                        | 6         | 8         | 12        | 10        | 1         | 7         | 9        | 0        | <u>11</u> | 4         | <u>14</u> | 3         | 13       | 5        | 15       | 16        | 17       | 18        |
+| 13   | 17  | 2                        | 6         | 8         | 12        | 10        | 1         | 7         | 9        | 0        | 11        | 4         | 14        | <u>17</u> | 13       | 5        | 15       | 16        | <u>3</u> | 18        |
+| 14   | 6   | 2                        | 6         | 8         | 12        | 10        | 1         | <u>13</u> | 9        | 0        | 11        | 4         | 14        | 17        | <u>7</u> | 5        | 15       | 16        | 3        | 18        |
+| 15   | 14  | 2                        | 6         | 8         | 12        | 10        | 1         | 13        | 9        | 0        | 11        | 4         | 14        | 17        | 7        | <u>5</u> | 15       | 16        | 3        | 18        |
+| 16   | 5   | 2                        | 6         | 8         | 12        | 10        | <u>15</u> | 13        | 9        | 0        | 11        | 4         | 14        | 17        | 7        | 5        | <u>1</u> | 16        | 3        | 18        |
+| 17   | 3   | 2                        | 6         | 8         | <u>16</u> | 10        | 15        | 13        | 9        | 0        | 11        | 4         | 14        | 17        | 7        | 5        | 1        | <u>12</u> | 3        | 18        |
+| 18   | 15  | 2                        | 6         | 8         | 16        | 10        | 15        | 13        | 9        | 0        | 11        | 4         | 14        | 17        | 7        | 5        | <u>3</u> | 12        | <u>1</u> | 18        |
+| 19   | 5   | 2                        | 6         | 8         | 16        | 10        | <u>18</u> | 13        | 9        | 0        | 11        | 4         | 14        | 17        | 7        | 5        | 3        | 12        | 1        | <u>15</u> |
+
+In the above process, the first step interchanged the first prime with prime "number" 10. The second step interchanged the second prime with prime "number" 14. The final step interchanged the nineteenth prime with prime "number" 5.
+
+The final order of the system modulating prime "numbers" is:
+
+2, 6, 8, 16, 10, 18, 13, 9, 0, 11, 4, 14, 17, 7, 5, 3, 12, 1, 15
+
+giving the final order of the system modulating prime numbers:
+
+32183, 31583, 31259, 29879, 30803, 29663, 30347, 31139, 32603
+
+30539, 31847, 30323, 29759, 31547, 31607, 32003, 30467, 32507, 30203
+
+The first three are used with the HFX40-I algorithm to generate PH and in the two encryptions SH and ESH.
+
+### E.3.4 Calculation of the primitives to be used with HFX40-I
+
+Eight phase primitives P(0) to P(7) are derived from SSx as follows.
+
+SSx, 568702123345, is split into eight overlapping groups of four digits. The first group being formed from the first 4 digits, the second from the third to sixth digits and so on. The first group of four digits are XOR'd with the second, the result of this is XOR'd with the third and so on. Two is added to each of the resulting values to prevent occurrences of an all zero result and the resulting values are used as the initial values for P(0) to P(7).
+
+An example with SSx = 568702123345 is shown in Table E.3.
+
+**Table E.3/T.36 – Calculation of the primitives to be used with HFX40-I**
+
+| SSx = 568702123345<br>The eight groups are: 5687, 8702, 7021, 0212, 2123, 1233, 2334 and 3345 |     |       |        |       |                  |
+|-----------------------------------------------------------------------------------------------|-----|-------|--------|-------|------------------|
+| Group                                                                                         |     |       | Result | Add 2 | Phase/Base value |
+| 5687                                                                                          |     |       |        | 5689  | P(0)             |
+| 8702                                                                                          | XOR | 5687  | 14281  | 14283 | P(1)             |
+| 7021                                                                                          | XOR | 14281 | 11428  | 11430 | P(2)             |
+| 212                                                                                           | XOR | 11428 | 11376  | 11378 | P(3)             |
+| 2123                                                                                          | XOR | 11376 | 9275   | 9277  | P(4)             |
+| 1233                                                                                          | XOR | 9275  | 8426   | 8428  | P(5)             |
+| 2334                                                                                          | XOR | 8426  | 10740  | 10742 | P(6)             |
+| 3345                                                                                          | XOR | 10740 | 9445   | 9447  | P(7)             |
+
+### E.3.5 Calculation of PH
+
+The phase values, P(0) to P(7) are used in rotation starting with P(1). When the initial value for P(1) has been used in the calculations with the first byte of the compressed message, it is replaced with a new value generated by the calculations detailed in the following paragraphs. This new value of P(1) is used the next time P(1) is used in the calculations. This same procedure is continued with P(2), P(3), etc. The whole procedure is continued until the end of the message and is explained in more detail below.
+
+Let the current phase value being used be P(n). P(n) is modified to form P'(n) by adding to P(n) the decimal ASCII value of the current message byte, b, and the Q (mod M) value, q, obtained from the previous byte. For the first byte, q = 0.
+
+$$P'(n) = P(n) + b + q$$
+
+Q is derived from P'(n) by multiplying by (b + 1).
+
+$$Q = P'(n) * (b + 1)$$
+
+Q is modulated by one of the 19 re-ordered system modulating prime numbers used in rotation starting from Prime (1) to form the new P(n) and q values. For example, for the first byte of the message, Q (mod M) forms the q value for the second byte and P(n) for the ninth byte. The order of the system modulating prime numbers is as determined in E.3.3. For the first byte of the message, Prime (1) is used, for the second byte Prime (2) and so on.
+
+Table E.4 shows the calculations to produce the hash for a 29 byte compressed facsimile message.
+
+PH, is formed by concatenating the 3 least significant digits of the final eight phase values taken in the order P(0), P(1), P(2), etc. to P(7) to produce a 24-digit number. In this example, from Table E.4:
+
+$$PH = 171\ 666\ 427\ 631\ 042\ 698\ 579\ 505$$
+
+### E.3.6 First encryption (scrambling) of PH to form SH
+
+SSx is used to derive three phase primitives, P(0) to P(2) and three base primitives, B(0) to B(2). SSx is split into six overlapping groups of three. The first digits 1-3 form P(0), digits 3-5 form P(1), digits 4-6 form P(2), digits 7-9 form B(0), digits 9-11 form B(1) and digits 10-12 form B(2).
+
+The first group of three digits are XOR'd with the second, the result of this is XOR'd with the third and so on. Two is added to each of the resulting groups of three to prevent occurrences of an all zero result. The new values are combined with the first 6 groups of three digits from PH to give the new values of P(0) to P(2) and B(0) to B(2).
+
+Table E.5 shows a sample calculation using the same example values as previously.
+
+**Table E.4/T.36 – Hash calculations for a 29 byte compressed facsimile message**
+
+| <b>b</b> | <b>y</b> | <b>P(n)</b> | <b>q</b> | <b>P'(n)</b> | <b>Q</b> | <b>M</b> | <b>Q(mod M)</b> | <b>Hash result</b> |                         |
+|----------|----------|-------------|----------|--------------|----------|----------|-----------------|--------------------|-------------------------|
+| 103      | 1        | 14283       | 0        | 14386        | 1496144  | 31583    | 11743           |                    |                         |
+| 121      | 2        | 11430       | 11743    | 23294        | 2841868  | 31259    | 28558           |                    |                         |
+| 2        | 3        | 11378       | 28558    | 39938        | 119814   | 29879    | 298             |                    |                         |
+| 0        | 4        | 9277        | 298      | 9575         | 9575     | 30803    | 9575            |                    |                         |
+| 34       | 5        | 8428        | 9575     | 18037        | 631295   | 29663    | 8372            |                    |                         |
+| 79       | 6        | 10742       | 8372     | 19193        | 1535440  | 30347    | 18090           |                    |                         |
+| 92       | 7        | 9447        | 18090    | 27629        | 2569497  | 31139    | 16099           |                    |                         |
+| 92       | 0        | 5689        | 16099    | 21880        | 2034840  | 32603    | 13454           |                    |                         |
+| 33       | 1        | 11743       | 13454    | 25230        | 857820   | 30539    | 2728            |                    |                         |
+| 33       | 2        | 28558       | 2728     | 31319        | 1064846  | 31847    | 13895           |                    |                         |
+| 33       | 3        | 298         | 13895    | 14226        | 483684   | 30323    | 28839           |                    |                         |
+| 10       | 4        | 9575        | 28839    | 38424        | 422664   | 29759    | 6038            |                    |                         |
+| 4        | 5        | 8372        | 6038     | 14414        | 72070    | 31547    | 8976            |                    |                         |
+| 238      | 6        | 18090       | 8976     | 27304        | 6525656  | 31607    | 14614           |                    |                         |
+| 161      | 7        | 16099       | 14614    | 30874        | 5001588  | 32003    | 9120            |                    |                         |
+| 141      | 0        | 13454       | 9120     | 22715        | 3225530  | 30467    | 26495           |                    |                         |
+| 24       | 1        | 2728        | 26495    | 29247        | 731175   | 32507    | 16021           |                    |                         |
+| 2        | 2        | 13895       | 16021    | 29918        | 89754    | 30203    | 29348           |                    |                         |
+| 3        | 3        | 28839       | 29348    | 58190        | 232760   | 32183    | 7479            |                    |                         |
+| 62       | 4        | 6038        | 7479     | 13579        | 855477   | 31583    | 2736            |                    |                         |
+| 149      | 5        | 8976        | 2736     | 11861        | 1779150  | 31259    | 28646           |                    |                         |
+| 66       | 6        | 14614       | 28646    | 43326        | 2902842  | 29879    | 4579            | <b>579</b>         | <b>[value for P(6)]</b> |
+| 11       | 7        | 9120        | 4579     | 13710        | 164520   | 30803    | 10505           | <b>505</b>         | <b>[value for P(7)]</b> |
+| 93       | 0        | 26495       | 10505    | 37093        | 3486742  | 29663    | 16171           | <b>171</b>         | <b>[value for P(0)]</b> |
+| 39       | 1        | 16021       | 16171    | 32231        | 1289240  | 30347    | 14666           | <b>666</b>         | <b>[value for P(1)]</b> |
+| 133      | 2        | 29348       | 14666    | 44147        | 5915698  | 31139    | 30427           | <b>427</b>         | <b>[value for P(2)]</b> |
+| 19       | 3        | 7479        | 30427    | 37925        | 758500   | 32603    | 8631            | <b>631</b>         | <b>[value for P(3)]</b> |
+| 124      | 4        | 2736        | 8631     | 11491        | 1436375  | 30539    | 1042            | <b>042</b>         | <b>[value for P(4)]</b> |
+| 92       | 5        | 28646       | 1042     | 29780        | 2769540  | 31847    | 30698           | <b>698</b>         | <b>[value for P(5)]</b> |
+
+**Table E.5/T.36 – Calculation of P(0) to P(2) and B(0) to B(2) for the first encryption of PH**
+
+| Session Key = 568702123345    |     |     |   |              |     |   |                  |   |                           |      |
+|-------------------------------|-----|-----|---|--------------|-----|---|------------------|---|---------------------------|------|
+| <b>Initial P and B values</b> |     |     |   | <b>Add 2</b> |     |   | <b>PH groups</b> |   | <b>New P and B values</b> |      |
+| 568                           |     |     |   | 568          | 570 | + | 171              | = | 741                       | P(0) |
+| 870                           | XOR | 568 | = | 350          | 352 | + | 666              | = | 1018                      | P(1) |
+| 021                           | XOR | 350 | = | 331          | 333 | + | 427              | = | 760                       | P(2) |
+| 123                           | XOR | 331 | = | 304          | 306 | + | 631              | = | 937                       | B(0) |
+| 334                           | XOR | 304 | = | 126          | 128 | + | 042              | = | 170                       | B(1) |
+| 345                           | XOR | 126 | = | 295          | 297 | + | 698              | = | 995                       | B(2) |
+
+The phase and base primitive values, P(0) to P(2) and B(0) to B(2) above, with the first three system modulating prime numbers, 32183, 31583 and 31259 from the re-ordered sequence derived in E.3.3, are used in the HKM algorithm in a similar way to that shown in E.4, to form the following 24-entry (mod 24) PRS:
+
+4, 5, 4, 16, 2, 6, 16, 12, 24, 21, 6, 5, 11, 4, 8, 21, 22, 5, 24, 9, 3, 16, 19, 8
+
+This PRS is used to transpose all 24 digits of PH to form SH. The first value in the PRS determines the position of the digit in PH which is interchanged with the first digit in PH, the second value determines the position of the digit which is interchanged with the second digit and so on. For the above PRS, the first step interchanges position 1 with position 4, the second step interchanges positions 2 and 5 and so on. This process continues until the final step in which position 24 is exchanged with position 8. Table E.6 shows the 24 stages of transpositions against the PRS.
+
+**Table E.6/T.36 – Transposition of PH to create SH**
+
+| Step/position                        | PRS | PH                  | 171         | 666         | 427         | 631         | 042         | 698         | 579         | 505 |
+|--------------------------------------|-----|---------------------|-------------|-------------|-------------|-------------|-------------|-------------|-------------|-----|
+| 1                                    | 4   | <u>6</u> 71         | <u>1</u> 66 | 427         | 631         | 042         | 698         | 579         | 505         |     |
+| 2                                    | 5   | <u>6</u> 6 <u>1</u> | <u>1</u> 76 | 427         | 631         | 042         | 698         | 579         | 505         |     |
+| 3                                    | 4   | <u>6</u> 6 <u>1</u> | <u>1</u> 76 | 427         | 631         | 042         | 698         | 579         | 505         |     |
+| 4                                    | 16  | 66 <u>1</u>         | <u>6</u> 76 | 427         | 631         | 042         | <u>1</u> 98 | 579         | 505         |     |
+| 5                                    | 2   | <u>6</u> 71         | <u>6</u> 66 | 427         | 631         | 042         | <u>1</u> 98 | 579         | 505         |     |
+| 6                                    | 6   | <u>6</u> 71         | <u>6</u> 66 | 427         | 631         | 042         | <u>1</u> 98 | 579         | 505         |     |
+| 7                                    | 16  | 671                 | 66 <u>6</u> | <u>1</u> 27 | 631         | 042         | <u>4</u> 98 | 579         | 505         |     |
+| 8                                    | 12  | 671                 | 666         | <u>1</u> 17 | <u>6</u> 32 | 042         | 498         | 579         | 505         |     |
+| 9                                    | 24  | 671                 | 666         | <u>1</u> 15 | <u>6</u> 32 | 042         | 498         | 579         | <u>5</u> 07 |     |
+| 10                                   | 21  | 671                 | 666         | 115         | <u>9</u> 32 | 042         | 498         | <u>5</u> 76 | 507         |     |
+| 11                                   | 6   | 671                 | <u>6</u> 63 | 115         | <u>9</u> 62 | 042         | 498         | 576         | 507         |     |
+| 12                                   | 5   | 671                 | <u>6</u> 23 | 115         | <u>9</u> 66 | 042         | 498         | 576         | 507         |     |
+| 13                                   | 11  | 671                 | 623         | 115         | <u>9</u> 06 | <u>6</u> 42 | 498         | 576         | 507         |     |
+| 14                                   | 4   | 671                 | <u>4</u> 23 | 115         | 906         | <u>6</u> 62 | 498         | 576         | 507         |     |
+| 15                                   | 8   | 671                 | 423         | <u>1</u> 25 | 906         | <u>6</u> 61 | 498         | 576         | 507         |     |
+| 16                                   | 21  | 671                 | 423         | 125         | 906         | 661         | <u>6</u> 98 | <u>5</u> 74 | 507         |     |
+| 17                                   | 22  | 671                 | 423         | 125         | 906         | 661         | <u>6</u> 58 | 574         | <u>9</u> 07 |     |
+| 18                                   | 5   | 671                 | <u>4</u> 83 | 125         | 906         | 661         | <u>6</u> 52 | 574         | 907         |     |
+| 19                                   | 24  | 671                 | 483         | 125         | 906         | 661         | 652         | <u>7</u> 74 | <u>9</u> 05 |     |
+| 20                                   | 9   | 671                 | 483         | <u>1</u> 27 | 906         | 661         | 652         | <u>7</u> 54 | 905         |     |
+| 21                                   | 3   | <u>6</u> 74         | 483         | <u>1</u> 27 | 906         | 661         | 652         | <u>7</u> 51 | 905         |     |
+| 22                                   | 16  | 674                 | 483         | 127         | 906         | 661         | <u>9</u> 52 | 751         | <u>6</u> 05 |     |
+| 23                                   | 19  | 674                 | 483         | 127         | 906         | 661         | <u>9</u> 52 | <u>0</u> 51 | <u>6</u> 75 |     |
+| 24                                   | 8   | 674                 | 483         | <u>1</u> 57 | 906         | 661         | 952         | 051         | <u>6</u> 72 |     |
+| SH = 674 483 157 906 661 952 051 672 |     |                     |             |             |             |             |             |             |             |     |
+
+### E.3.7 Encryption of SH to form ESH
+
+Three phase primitives, P(0) to P(2), and three base primitives B(0) to B(2) are derived from SSx in a similar process to that in E.3.6, except that the values resulting from the XOR and addition of 2 calculations are combined with the first six groups of three digits in SH to give the new values which are used as the initial values of P(0) to P(2) and B(0) to B(2).
+
+Table E.7 shows the results for the calculations using the SH value obtained in E.3.6.
+
+**Table E.7/T.36 – Calculation of the primitives for the Encryption of EH to form ESH**
+
+| SH = 674 483 157 906 661 952 051 672 |     |     |   |       |     |   |           |   |                    |      |
+|--------------------------------------|-----|-----|---|-------|-----|---|-----------|---|--------------------|------|
+| Initial P and B values               |     |     |   | Add 2 |     |   | SH Groups |   | New P and B values |      |
+| 568                                  |     |     |   | 568   | 570 | + | 674       | = | 1244               | P(0) |
+| 870                                  | XOR | 568 | = | 350   | 352 | + | 483       | = | 835                | P(1) |
+| 021                                  | XOR | 350 | = | 331   | 333 | + | 157       | = | 490                | P(2) |
+| 123                                  | XOR | 331 | = | 304   | 306 | + | 906       | = | 1212               | B(0) |
+| 334                                  | XOR | 304 | = | 126   | 128 | + | 661       | = | 789                | B(1) |
+| 345                                  | XOR | 126 | = | 295   | 297 | + | 952       | = | 1249               | B(2) |
+
+The phase and base primitive values, P(0) to P(2) and B(0) to B(2) above, together with the first three system modulating prime numbers 32183, 31583 and 31259, from the re-ordered sequence derived in E.3.3, are used in the HKM algorithm in a similar way to the example in E.4, to generate 24 entries in a (mod 10) PRS which are added (mod 10) to SH to form ESH.
+
+SH: 674 483 157 906 661 952 051 672
+
+(mod 10) PRS: 402 025 183 343 270 975 304 836
+
+ESH: 076 408 230 249 831 827 355 408
+
+## E.4 Use of the HKM Algorithm to produce a PseudoRandom Sequence
+
+### E.4.1 Introduction
+
+This subclause provides an example using test values to verify the implementation of the operation of the HKM algorithm using modular arithmetic to generate a PseudoRandom Sequence, PRS.
+
+The modular arithmetic uses phase and base primitive values derived in a number of ways from a secret number, such as a session key, or a combination of a secret number and other identifying information, together with moduli taken from the universal set of system modulating prime numbers to generate a PRS which may be further modulated to form a specific PRS.
+
+#### E.4.1.1 Calculations using HKM to generate a PRS
+
+The test values used in this example are those used in E.3.3 to form the 19-entry (mod 19) PRS to re-order the system modulating prime numbers.
+
+The 3 phase primitives, P(0) to P(2) and the 3 base primitives B(0) to B(2) are:
+
+$$\begin{array}{ll} P(0) = 570 & B(0) = 306 \\ P(1) = 352 & B(1) = 128 \\ P(2) = 333 & B(2) = 297 \end{array}$$
+
+The 3 system modulating primes are: 32603, 32507 and 32183
+
+Using the first "set" of phase, base and prime values, P(0), B(0) and 32603:
+
+P(0) is multiplied by B(0)
+
+$$570 * 306 = 174420$$
+
+$$174420 \text{ (mod the first prime)} = 174420 \text{ (mod 32603)} = 11405$$
+
+11405 is then used as a new phase value and is multiplied by the base value, B(0)
+
+$$11405 * 306 = 3489930$$
+
+$$3489930 \text{ (mod the first prime)} = 3489930 \text{ (mod 32603)} = 1409$$
+
+This process is carried out a total of 19 times (corresponding to the number of primes to be re-ordered). The complete process is also repeated for the remaining 2 "sets" of phase, base and prime values to generate similar sequences.
+
+The results of the first calculation from each of the 3 phase, base and prime "sets" are added to form the first value in the total column. The results from each of the other calculations are added to form the other entries in the total column. The resulting sequence in this example is modulated by 19 to generate a (mod 19) PRS. Other suitable numbers can be used to modulate the sequence to generate other specific PRSs.
+
+The full set of calculations is shown in Table E.8.
+
+**Table E.8/T.36 – Calculations using HKM to generate a 19-entry (mod 19) PRS**
+
+| Modulating Prime<br>B(n)<br>P(n) | 32603<br>306<br>570 | 32507<br>128<br>352 | 32183<br>297<br>333 | Total | (mod 19) PRS |
+|----------------------------------|---------------------|---------------------|---------------------|-------|--------------|
+|                                  | 11405               | 12549               | 2352                | 26306 | <b>10</b>    |
+|                                  | 1409                | 13429               | 22701               | 37539 | <b>14</b>    |
+|                                  | 7315                | 28548               | 15950               | 51813 | <b>0</b>     |
+|                                  | 21386               | 13360               | 6249                | 40995 | <b>12</b>    |
+|                                  | 23516               | 19716               | 21522               | 64754 | <b>2</b>     |
+|                                  | 23236               | 20609               | 19800               | 63645 | <b>14</b>    |
+|                                  | 2762                | 4885                | 23294               | 30941 | <b>9</b>     |
+|                                  | 30097               | 7647                | 31156               | 68900 | <b>6</b>     |
+|                                  | 15636               | 3606                | 16811               | 36053 | <b>10</b>    |
+|                                  | 24578               | 6470                | 4502                | 35550 | <b>1</b>     |
+|                                  | 22178               | 15485               | 17591               | 55254 | <b>2</b>     |
+|                                  | 5044                | 31660               | 10881               | 47585 | <b>9</b>     |
+|                                  | 11123               | 21612               | 13357               | 46092 | <b>17</b>    |
+|                                  | 12926               | 3241                | 8520                | 24687 | <b>6</b>     |
+|                                  | 10393               | 24764               | 20166               | 55323 | <b>14</b>    |
+|                                  | 17767               | 16613               | 3264                | 37644 | <b>5</b>     |
+|                                  | 24604               | 13509               | 3918                | 42031 | <b>3</b>     |
+|                                  | 30134               | 6281                | 5058                | 41473 | <b>15</b>    |
+|                                  | 26958               | 23800               | 21808               | 72566 | <b>5</b>     |
+
+# ITU-T RECOMMENDATIONS SERIES
+
+|                 |                                                                                                                |
+|-----------------|----------------------------------------------------------------------------------------------------------------|
+| Series A        | Organization of the work of the ITU-T                                                                          |
+| Series B        | Means of expression: definitions, symbols, classification                                                      |
+| Series C        | General telecommunication statistics                                                                           |
+| Series D        | General tariff principles                                                                                      |
+| Series E        | Overall network operation, telephone service, service operation and human factors                              |
+| Series F        | Non-telephone telecommunication services                                                                       |
+| Series G        | Transmission systems and media, digital systems and networks                                                   |
+| Series H        | Audiovisual and multimedia systems                                                                             |
+| Series I        | Integrated services digital network                                                                            |
+| Series J        | Transmission of television, sound programme and other multimedia signals                                       |
+| Series K        | Protection against interference                                                                                |
+| Series L        | Construction, installation and protection of cables and other elements of outside plant                        |
+| Series M        | Maintenance: international transmission systems, telephone circuits, telegraphy, facsimile and leased circuits |
+| Series N        | Maintenance: international sound programme and television transmission circuits                                |
+| Series O        | Specifications of measuring equipment                                                                          |
+| Series P        | Telephone transmission quality, telephone installations, local line networks                                   |
+| Series Q        | Switching and signalling                                                                                       |
+| Series R        | Telegraph transmission                                                                                         |
+| Series S        | Telegraph services terminal equipment                                                                          |
+| <b>Series T</b> | <b>Terminals for telematic services</b>                                                                        |
+| Series U        | Telegraph switching                                                                                            |
+| Series V        | Data communication over the telephone network                                                                  |
+| Series X        | Data networks and open system communication                                                                    |
+| Series Z        | Programming languages                                                                                          |
\ No newline at end of file
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/03d25ffe678fd3896eaec701688dd617_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/03d25ffe678fd3896eaec701688dd617_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..4433824d0bfa3ae3424f13411eccee706872fb51
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/03d25ffe678fd3896eaec701688dd617_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:b08d588e4abc08d2a0d1acd5a6c00c046284925870f0dc65a9d378b4ab414b32
+size 707
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/077f85b82901283b4657fd2b45fc0294_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/077f85b82901283b4657fd2b45fc0294_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..8f23f7e3ef36a0f45d6e3d5c2c40d06aa1e71135
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/077f85b82901283b4657fd2b45fc0294_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:8411bc982cb7af199a6db17cf6d5fa923774aeaabbc5b95008cbbbf9b7624fb8
+size 36404
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/0a65aacb7165a748a6b858978b0a18eb_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/0a65aacb7165a748a6b858978b0a18eb_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..b9e0063e57736e057cdf823161299244b9f80e71
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/0a65aacb7165a748a6b858978b0a18eb_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:01016286d32ee5cc3817f4dd08082febc69cf4ae48e6159ed675ebcc6ebfeb05
+size 1022
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/0a68b003bef52cf4f7adc736872714b4_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/0a68b003bef52cf4f7adc736872714b4_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..75c6ab80eca21445fb19e329bc3327d4b1d87e7a
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/0a68b003bef52cf4f7adc736872714b4_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:b8d87774b53e3e8f8299d509a50363aaf89e54a8ba7a483a070f04c81eefcf91
+size 1653
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/0ab54b66e397b010140fd64745d23994_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/0ab54b66e397b010140fd64745d23994_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..4433824d0bfa3ae3424f13411eccee706872fb51
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/0ab54b66e397b010140fd64745d23994_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:b08d588e4abc08d2a0d1acd5a6c00c046284925870f0dc65a9d378b4ab414b32
+size 707
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/0cb508fe450c297218f2c72d6c508242_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/0cb508fe450c297218f2c72d6c508242_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..a385094df773a1f3860162d7803a3dab6d376f93
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/0cb508fe450c297218f2c72d6c508242_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:d44828b5de8cb8375ab9e0cd095413678204538849769868d1d4cd310410e6f8
+size 1120
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/0dfdc3be0aff6da9d545ef4a9fbeeba4_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/0dfdc3be0aff6da9d545ef4a9fbeeba4_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..e57c7355be1538a57a636ab2317a772f1dc2a700
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/0dfdc3be0aff6da9d545ef4a9fbeeba4_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:6fe6eed9b794776d47e47babcf3fc173937fb96245c20643ee7e648e12998702
+size 1249
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/107da2e3495b2f24352c9e3b26ec4841_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/107da2e3495b2f24352c9e3b26ec4841_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..233f9535f565943f4c983a4c7c248c1b9ddba943
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/107da2e3495b2f24352c9e3b26ec4841_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:e8ee11acf6af013d657690ece3f7f1f7a82271e24b208bb11112cadbac46c02d
+size 129506
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/12c19090355e19922e23044633b9d1ea_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/12c19090355e19922e23044633b9d1ea_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..4652c69d570f82fe70605eac0918fff9597de5bc
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/12c19090355e19922e23044633b9d1ea_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:fcbdf7ff2fe8904ada250b77db0c81da049492beedfb3b7bd5e8f06adc49feaf
+size 26467
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/13b8b4b75a727e81e9b7e185ed92646b_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/13b8b4b75a727e81e9b7e185ed92646b_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..e6c06de57b1710913cea0b29359e6a5c88b6942b
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/13b8b4b75a727e81e9b7e185ed92646b_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:d5efc1a886aa3c196a7724444303c5b007cfa66de431e0996c11729463aab8ee
+size 1059
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/177cf8047cfab548509c02e2853d2b80_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/177cf8047cfab548509c02e2853d2b80_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..f4a77a7e4a1c25626dc7a1bb21d7ff774741a8a9
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/177cf8047cfab548509c02e2853d2b80_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:73ad62bafc3c20c5adeaf847162398f67e0331d3be58629f70d5ce199ed387df
+size 707
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/1899ae00e6bd96dca7d3907ef8fec5c1_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/1899ae00e6bd96dca7d3907ef8fec5c1_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..aadbdabee68aab63dfaef542519180af066a13ee
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/1899ae00e6bd96dca7d3907ef8fec5c1_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:9305e7f64f69be8d2d7936e13e035ace39ba672042ab0796c2da1e8280bb0808
+size 982
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/18bb6b1b38576996def82c7de5cc0bb1_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/18bb6b1b38576996def82c7de5cc0bb1_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..7ec66b2fd0372af0750ff8775397f28ed711fade
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/18bb6b1b38576996def82c7de5cc0bb1_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:9efb5e0b2d677180655d9dc44cdb2c82199d56e1437b6a463efcaf092a8ac0e8
+size 1211
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/18d8cb951a9ddc3929f9af72e8c183d2_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/18d8cb951a9ddc3929f9af72e8c183d2_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..f4a77a7e4a1c25626dc7a1bb21d7ff774741a8a9
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/18d8cb951a9ddc3929f9af72e8c183d2_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:73ad62bafc3c20c5adeaf847162398f67e0331d3be58629f70d5ce199ed387df
+size 707
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/1ae8fdf55aa601eb1b247ca4776aa383_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/1ae8fdf55aa601eb1b247ca4776aa383_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..d8b75aec23ea6d9bebfdd422e0954ff1376d5630
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/1ae8fdf55aa601eb1b247ca4776aa383_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:59dbed31653afef6246be4b3ca6677c0050c92b445ebb412e5a4860c1c12f0a7
+size 895
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/1c9a5a80a4ed18fdfda1c8ae915966bf_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/1c9a5a80a4ed18fdfda1c8ae915966bf_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..be19436337422ff9352bb08c1859c2f801b6b3a7
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/1c9a5a80a4ed18fdfda1c8ae915966bf_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:ba62c63a66541e1fcd2017b65ad0773025bbcab227abf8df8e396970cff1b64a
+size 12551
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/1ffc81a5ffede49478c6e164968e619a_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/1ffc81a5ffede49478c6e164968e619a_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..159f520d285c6b2058cbe33eb4bed80c0ddf8226
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/1ffc81a5ffede49478c6e164968e619a_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:54e0c165a9a8a9b4042774292d4a64c0e9b2ff73be1b82fe14884e1b8a22931d
+size 1032
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/23a9a17a48fd53a1f6fbf21ec954aa6d_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/23a9a17a48fd53a1f6fbf21ec954aa6d_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..f4a77a7e4a1c25626dc7a1bb21d7ff774741a8a9
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/23a9a17a48fd53a1f6fbf21ec954aa6d_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:73ad62bafc3c20c5adeaf847162398f67e0331d3be58629f70d5ce199ed387df
+size 707
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/24200dcfe446591f0ad63013e7eaece3_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/24200dcfe446591f0ad63013e7eaece3_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..28f99d9d789d51d814e47fc9c34cd206feacdb42
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/24200dcfe446591f0ad63013e7eaece3_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:671185cf2be0ed51efdbfc560b0f6193ba43d0fe8bcd48601e34f929b7ddda10
+size 1829
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/261acba7a637638918e1eb61ff76f9b0_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/261acba7a637638918e1eb61ff76f9b0_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..e8335b95d87bf27d1a4996a4e436397d67da4b2e
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/261acba7a637638918e1eb61ff76f9b0_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:e506623c30bc724bb26a427dfd86b9ba139da6c13fc933c7e07d325ea466595b
+size 1227
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/272b0da7f838387d996a2e1edc966652_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/272b0da7f838387d996a2e1edc966652_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..547cb728e3758df316b3a8f3ff90c08f7096ec96
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/272b0da7f838387d996a2e1edc966652_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:8ff0f1302f581767ebcf46d480e7514a5b59a4cd8b09428ba2257525a530aa32
+size 991
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/29136afec0fda05beed9946c5fcbeaa2_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/29136afec0fda05beed9946c5fcbeaa2_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..f4a77a7e4a1c25626dc7a1bb21d7ff774741a8a9
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/29136afec0fda05beed9946c5fcbeaa2_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:73ad62bafc3c20c5adeaf847162398f67e0331d3be58629f70d5ce199ed387df
+size 707
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/29f586959675cafdf81cf934954908eb_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/29f586959675cafdf81cf934954908eb_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..851eead0abce7d998bee0802438d7cc246f53f2d
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/29f586959675cafdf81cf934954908eb_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:aba84739d1bade5e23ad49abc78f6b0fd658722050dad58b5591e2b076d08252
+size 12822
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/2d29342d19801080318ad1463e6c549b_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/2d29342d19801080318ad1463e6c549b_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..5d0df9cd8b89053c06f0a6bbea2f572d65da2001
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/2d29342d19801080318ad1463e6c549b_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:f4b000841cbbda2c52b1e52c8b7a3b26f1eb7d304df28fde585bbda004fb86c7
+size 1078
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..baae88ea7ecb14e6792d9494433b8c2f688f7784
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:c0ad94d11b4a4a4706af80946b251a1cd8ae366ffd7442c046f616a63e23f740
+size 8341
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/2f13df1aaff665f77d207213ed5fcefc_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/2f13df1aaff665f77d207213ed5fcefc_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..aef1f32612c373c920461336ccc2c3026eeaf638
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/2f13df1aaff665f77d207213ed5fcefc_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:31756aa0fde5efcceeb99c9282c82bd5a1d454ba86e57caf79da8cf6667d572c
+size 1304
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/31a8899b1a9e22ce19532a0f7f661599_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/31a8899b1a9e22ce19532a0f7f661599_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..d78acd6c6e02c6048db444aef11c3ac6e6345597
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/31a8899b1a9e22ce19532a0f7f661599_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:8757a02f3a9e43f56b666741875ebe4b82058f038773119b37ab0b0b4054ed85
+size 942
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/331f0ef3132050223b1066d55c3c925b_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/331f0ef3132050223b1066d55c3c925b_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..0c7c04d65b77d37fe9e0425dfc1d0d0e61d23716
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/331f0ef3132050223b1066d55c3c925b_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:15bcf75c9abbf1246543bce3a2b57f0ec2a9f4ac49dca45ab90597f04760724f
+size 951
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/33a8f3f01dfa8bce75d23017855a13c5_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/33a8f3f01dfa8bce75d23017855a13c5_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..b6b78b7ca7c023d63ed8ef2c16e24125343f5201
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/33a8f3f01dfa8bce75d23017855a13c5_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:7097ae1e1aa31156b2f700cb72568f7ca51ae8b1253d1f31534806564b87913a
+size 14278
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/3733231163bb7df8625f86a7cfb08365_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/3733231163bb7df8625f86a7cfb08365_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..35e039061a3fb774d4ef45f0043a38dbbef5e7ff
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/3733231163bb7df8625f86a7cfb08365_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:8ef43dadcfa679a8a96f2cf84862eff7b3641e49193f07f53849f677a9c947b2
+size 1220
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/373b22107fee43412356511839a8a54e_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/373b22107fee43412356511839a8a54e_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..fb7b0f47d83dbe3ee6c7367fb79591aa799c6d39
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/373b22107fee43412356511839a8a54e_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:d924ea7e72f32561d8b6abed5097ace9c3a4d9601841e4df3eeac79220db940f
+size 1161
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/3991d730c6d44c8f189a746210f45851_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/3991d730c6d44c8f189a746210f45851_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..eb216c125ebfcd508e087ef368c9c214029f807f
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/3991d730c6d44c8f189a746210f45851_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:4d38a2ccc120ae2e6c8c5e6015ed870830aca392e6e53bbda76257b915b7306b
+size 1251
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/39b708e597bf3110ee29955506c476f5_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/39b708e597bf3110ee29955506c476f5_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..27e4a8e29b275ea379720d2dd290a809cf6bc6f9
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/39b708e597bf3110ee29955506c476f5_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:75e0903c48586a9a5126e28e6a4dc500bba553e3aabad6afee815a00c38901de
+size 1578
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/3a3276469026efbb838b2b6016e825a0_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/3a3276469026efbb838b2b6016e825a0_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..db921f01655a6b5b7941c730a250ea8704220ce3
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/3a3276469026efbb838b2b6016e825a0_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:b2f5d26db57fca2e76252d6a5eafedf5f0506e3131ddb1847ec7af1f1b43878d
+size 948
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/3adbb733fab929b36e5c91f902e32dcf_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/3adbb733fab929b36e5c91f902e32dcf_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..f4a77a7e4a1c25626dc7a1bb21d7ff774741a8a9
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/3adbb733fab929b36e5c91f902e32dcf_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:73ad62bafc3c20c5adeaf847162398f67e0331d3be58629f70d5ce199ed387df
+size 707
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/3b0bd33811c58bc62c562042b624dd49_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/3b0bd33811c58bc62c562042b624dd49_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..68986028e7f592da11c8ab203fad08066915021e
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/3b0bd33811c58bc62c562042b624dd49_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:5c1d577ddc8c88359e03e80c829f07e4be2428cc52fa4ec9a2b46846faba7930
+size 913
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/3b209b77c317e84fa84c39bf53a89de1_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/3b209b77c317e84fa84c39bf53a89de1_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..f4a77a7e4a1c25626dc7a1bb21d7ff774741a8a9
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/3b209b77c317e84fa84c39bf53a89de1_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:73ad62bafc3c20c5adeaf847162398f67e0331d3be58629f70d5ce199ed387df
+size 707
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/3b214a38ecd72eb3edf18b4371c0ce51_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/3b214a38ecd72eb3edf18b4371c0ce51_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..97dc83df799bd937a5cbe8834984194a370efe27
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/3b214a38ecd72eb3edf18b4371c0ce51_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:a04f8ee69c94555103ddc43a13e1fbcb95b915312ee105b3e8083b9af9f7330d
+size 1228
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/3bfa6c953b8dc25df07d76d4b0f98f65_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/3bfa6c953b8dc25df07d76d4b0f98f65_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..4433824d0bfa3ae3424f13411eccee706872fb51
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/3bfa6c953b8dc25df07d76d4b0f98f65_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:b08d588e4abc08d2a0d1acd5a6c00c046284925870f0dc65a9d378b4ab414b32
+size 707
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/3c269f1e84210b082c910d84b0cd6da3_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/3c269f1e84210b082c910d84b0cd6da3_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..2012574dc13c656426243c83fa32a5a75750fee6
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/3c269f1e84210b082c910d84b0cd6da3_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:37bcaf1bc0a0908a997f396cb1c5ca10c234dc7660b84120552d910222c5da99
+size 1001
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/40ed77c62efe51f8f3060c7571fb6318_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/40ed77c62efe51f8f3060c7571fb6318_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..1903736ea6479f03a4204774a7dcf9098785e055
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/40ed77c62efe51f8f3060c7571fb6318_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:6cc5746534d1248d9c8cc89d0c83b88128ff8704a5e508661fa365d28c7bb6fc
+size 971
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/41f4af2fa0f4743bfa39bc6778c99ffd_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/41f4af2fa0f4743bfa39bc6778c99ffd_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..90a688a67c8c0d2878971bdcd491b046896364e6
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/41f4af2fa0f4743bfa39bc6778c99ffd_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:404bb6545222eaf001023bd6364e47ef7a3b5cb6e5f7ec00edf7ae27c7f33347
+size 1360
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/4260538218b8b0537f4b66b0aceeedb8_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/4260538218b8b0537f4b66b0aceeedb8_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..fadbad965f33fc093e3f1cda0ca313c1742427b7
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/4260538218b8b0537f4b66b0aceeedb8_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:3d501cb8bf48f8d11475a9ad2fe53ec0c9bb6b5cb3ff9be7e320e2c0b2f456fe
+size 1090
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/4337578c1b2c0abf924ec423268930b1_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/4337578c1b2c0abf924ec423268930b1_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..f97a8eadc0615b97a44b5c03fc06be117f1b1a31
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/4337578c1b2c0abf924ec423268930b1_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:f56ccb8fdca02fd1fc6540affccc4848d88eaf46fbcd3daad19a35bf229c376c
+size 1830
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/457677e58b88549b3e86386a92dfcd2b_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/457677e58b88549b3e86386a92dfcd2b_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..9929bc180cbe3123ec0e08e67d4cd433de122f35
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/457677e58b88549b3e86386a92dfcd2b_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:95d9e0da8c1f18a0207af61ee07d737a6df36974dc708c578e144b0b1297d081
+size 1163
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/49b95722048d37d883a91d525b17b8e4_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/49b95722048d37d883a91d525b17b8e4_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..2dd6b56dd2be9fe6b2cbe244e47e4406d171cc4e
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/49b95722048d37d883a91d525b17b8e4_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:a54fc5ff4e4f4425497d9d4fd474a73cf2e6aab1c29f04706edc4eff089d8824
+size 1158
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/4b15482e14a69ff8e20f3c24dbf006f4_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/4b15482e14a69ff8e20f3c24dbf006f4_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..5c22d6fcafccdb62ae3aca0815974e1d7c40f7e8
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/4b15482e14a69ff8e20f3c24dbf006f4_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:ffa85081dfeff48488fc0b25671ae7fc97ce9703a6b926e9321ce25e1d33be1d
+size 1413
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/4d039891dff51b88fc87d04baabe2dfd_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/4d039891dff51b88fc87d04baabe2dfd_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..42223f30cf973a380728c671ae2cd80ab012fb7b
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/4d039891dff51b88fc87d04baabe2dfd_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:96e12a3373f44d3da654f4e26eb7fba529eac7f48323980ea4da6be1dfd41043
+size 1539
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/4d86313e88c97b80374c74c0142af33d_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/4d86313e88c97b80374c74c0142af33d_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..e8b0c57b7122ea9b65e2189825a92e52ad8b0d80
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/4d86313e88c97b80374c74c0142af33d_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:fcce8fc2231660f248584e1429dfc770de72bfefc975e897c06990833f856ad6
+size 1564
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/4df1d1d19fdfb7e725c4406593154537_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/4df1d1d19fdfb7e725c4406593154537_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..c71c489c32ed6ccf5671e11c5e92f7ea83e36d3e
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/4df1d1d19fdfb7e725c4406593154537_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:8052e6b2c08d8026eabdd32c5415b3830790f94ad1bd989747857eeacd98b027
+size 1257
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/51eb5d272fdbdb02ec742321b25f8b9e_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/51eb5d272fdbdb02ec742321b25f8b9e_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..8981f66fb536d99b4c9a381d9c3e12a72c7a2f5f
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/51eb5d272fdbdb02ec742321b25f8b9e_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:83cdc4d95f0019460f4e282392aff12f2f24c51b01e8b56d94b890fd9fa4d1e8
+size 1559
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/5793a44ffdadd039928e2f9fe6daae06_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/5793a44ffdadd039928e2f9fe6daae06_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..0320a06adbecfb7f52f89e69793c7b9974c8ae25
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/5793a44ffdadd039928e2f9fe6daae06_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:0aa45f02e72c6a9bab409e40600d6378d4699f5e8bd35f0320501dcf1813da60
+size 37512
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/58691c38df1ae8a2f1723967d1fd3182_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/58691c38df1ae8a2f1723967d1fd3182_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..77a5f5a7910b83e33c700dc7f8cb54baaaced369
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/58691c38df1ae8a2f1723967d1fd3182_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:e92749e5a1f01f1b5ed01a44edaf593ae0d31b90624ee61d47f3205e6b05c920
+size 1563
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/5a0de8cde670fb8eb8a284e62e8a2c67_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/5a0de8cde670fb8eb8a284e62e8a2c67_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..3a9645b3e52d5376ad547842c9b45b2de3af4eb3
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/5a0de8cde670fb8eb8a284e62e8a2c67_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:0409b100597798ba9c2ae397048bcd5aa73314f3169b17e0a19f2c0033800ce3
+size 958
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/5b3c16a95a8e4d8e3e9d788833a190c8_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/5b3c16a95a8e4d8e3e9d788833a190c8_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..9eb4159e88cf4a2cd6be47d428e9711bf63c6439
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/5b3c16a95a8e4d8e3e9d788833a190c8_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:67c337cd58ed71406d0f1c9c635f71c56b151fb307b21aa861a2f66a2c045cba
+size 1040
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/5b99b01558164abe3146b9144e6deb48_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/5b99b01558164abe3146b9144e6deb48_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..37c82f9191e3bb7275eddfa0e9cfd6c6d0f33153
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/5b99b01558164abe3146b9144e6deb48_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:cf4ee2d62fa7da96342bc734049e92cb4eedda58cd1da11abf29b94ce6aa8ee5
+size 1094
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/5c8bde33f40711b8fbfb6c234f04aef1_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/5c8bde33f40711b8fbfb6c234f04aef1_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..4bacb34d1cd5733d273ce62b67b1bef7bbfd8579
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/5c8bde33f40711b8fbfb6c234f04aef1_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:a6f6a18e20d40e7294314e13fb1b0febbf5479c780fa23438da578ae4cd332a9
+size 1022
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/61bc9600170a62a82f382cf07a50cbe0_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/61bc9600170a62a82f382cf07a50cbe0_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..746204ff158f1f5fb0e9a77902c6e859e9f03554
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/61bc9600170a62a82f382cf07a50cbe0_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:e70aa65ce7e8af52b77819203c63acb9630713454c4f4339ef6a42fb279af5f0
+size 1313
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/6231ba981d3d1ab7ce0cae71abd08c17_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/6231ba981d3d1ab7ce0cae71abd08c17_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..c63c3736df3baa83a90d5a72968f0db3af92f256
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/6231ba981d3d1ab7ce0cae71abd08c17_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:75b74524b52bb6e9b83126b1cfe0708d5cdf3bac891ea38438420dcf7f93f525
+size 13367
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/64e2bcc7bf695ea6ad89b0a691af274f_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/64e2bcc7bf695ea6ad89b0a691af274f_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..a7677da75c63d4ffd83fba560ff1435bf591596f
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/64e2bcc7bf695ea6ad89b0a691af274f_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:145c7996bfc55d070493a28714cf0148eda8dd083260649c0aa48370b13706bc
+size 969
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/66caf31e06bfa1535de948f1fbe4c8f1_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/66caf31e06bfa1535de948f1fbe4c8f1_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..13eb32c18dd4758cfa0874d6eb25021f9a401f55
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/66caf31e06bfa1535de948f1fbe4c8f1_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:46194847c1d947ac3df3193561346d7119c77014921b68d3e5190c91b6f6cd1a
+size 1469
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/6afdeb128427fca40aea8eef5e90999a_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/6afdeb128427fca40aea8eef5e90999a_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..b32c0a6817a37627437e2979e84ee18ea6e2d450
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/6afdeb128427fca40aea8eef5e90999a_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:109cb42e6d639bb3e5fa7bd7e0e7c21ffee148934a91f8999c159b3e5afda48e
+size 1285
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/6bef7140476346577537d22895e9dd0e_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/6bef7140476346577537d22895e9dd0e_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..63a0f400e7d7d8abb7c3d7522b6054722c28c643
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/6bef7140476346577537d22895e9dd0e_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:10559274c912f671606fe32d99f1c2be62415d3ac191fa0ecd6e26c7f959240e
+size 829
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/6c4813272fa804f643c2d2abce7ecb71_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/6c4813272fa804f643c2d2abce7ecb71_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..060d4670ee50b4fe8b7e265506372a788fd4ee25
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/6c4813272fa804f643c2d2abce7ecb71_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:90c98e8f21022ee58148bd9920a01a102360aea1fd220f63a70eb01db29193b4
+size 1214
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/6c59e8a35306d0f7e2b96ddcf593e7a8_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/6c59e8a35306d0f7e2b96ddcf593e7a8_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..291fe27c0a980840c1c8253262db2bdbdc971ae5
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/6c59e8a35306d0f7e2b96ddcf593e7a8_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:01b156fe7e7dc6ac89656225a90a0d8c64163562ec24e9b683778d1747888309
+size 1627
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/6ebc34a5f3ef20873a191976538d800e_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/6ebc34a5f3ef20873a191976538d800e_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..9f6241b57287521f459c9ef2e54acfa4ba9c4e07
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/6ebc34a5f3ef20873a191976538d800e_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:0c8a40a0eceb7eee78dc4058204b22220d4a7b4dccb1506861490dfe4cb8d761
+size 707
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/6ef107440832607ae9c5b130f349813c_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/6ef107440832607ae9c5b130f349813c_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..4433824d0bfa3ae3424f13411eccee706872fb51
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/6ef107440832607ae9c5b130f349813c_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:b08d588e4abc08d2a0d1acd5a6c00c046284925870f0dc65a9d378b4ab414b32
+size 707
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/73a41e18b9a64b090552df542291770d_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/73a41e18b9a64b090552df542291770d_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..9409eed2ee3e1642b827cceaa84cf6a13b261e0f
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/73a41e18b9a64b090552df542291770d_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:a107842d001649bd3505b5a561a36fde5705902a64b5da50c64c8eeb80f02d71
+size 1617
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/75ffee09e4f5643bb7252c08d9304fb6_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/75ffee09e4f5643bb7252c08d9304fb6_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..e7fa40d5dfa2abf2bcbfc2c320d0b794a5409c69
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/75ffee09e4f5643bb7252c08d9304fb6_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:544ada53b04667caed6c4c9db7b442a6689bb818aeb6baa6e322db808fdcfc4e
+size 1092
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/76671a4f69fde6771e7b01d16486c88e_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/76671a4f69fde6771e7b01d16486c88e_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..4433824d0bfa3ae3424f13411eccee706872fb51
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/76671a4f69fde6771e7b01d16486c88e_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:b08d588e4abc08d2a0d1acd5a6c00c046284925870f0dc65a9d378b4ab414b32
+size 707
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/76b0cd79baaedd942af4dc42f2e764b8_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/76b0cd79baaedd942af4dc42f2e764b8_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..656f6b3f2e13704b482cfe9426b3dd4683b4e531
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/76b0cd79baaedd942af4dc42f2e764b8_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:87853e200dbd8a41cd1df87efd9bbedc5a292cbb009c6292e9c02f9244ffe115
+size 11397
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/778bbd45c3f5a2dd0ba631c2484214af_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/778bbd45c3f5a2dd0ba631c2484214af_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..902b39caf63e5ca6b1d64ddd4b8966f3cb5ac49f
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/778bbd45c3f5a2dd0ba631c2484214af_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:0a4e3522aa9b02ade39ba4417785ba1aa32c6bd4764e0730dbd317b4b893cd82
+size 1010
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/798679874d1c29f8343506a156c79d7e_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/798679874d1c29f8343506a156c79d7e_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..7495ef8cad3a2f9cbccaa1061e4b59fb5074babe
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/798679874d1c29f8343506a156c79d7e_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:c0134217c471ddcf89e9dcf0f8ede2f985c1e4298411ab76f414792a9b657211
+size 64736
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/798a9b16ac0b100457483adb36a35efe_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/798a9b16ac0b100457483adb36a35efe_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..7425b8b381a7c38a5716a8f46b6333bf7b02a65f
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/798a9b16ac0b100457483adb36a35efe_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:d9cb11e914deec4650ee4836364035ca94f784eff4e05d58cd8caf7c6f7d88a1
+size 1307
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/811036de9eaca05b96032d2adb29260c_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/811036de9eaca05b96032d2adb29260c_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..f4a77a7e4a1c25626dc7a1bb21d7ff774741a8a9
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/811036de9eaca05b96032d2adb29260c_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:73ad62bafc3c20c5adeaf847162398f67e0331d3be58629f70d5ce199ed387df
+size 707
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/815a2cdfe027baca05a32e5137a660f1_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/815a2cdfe027baca05a32e5137a660f1_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..9f6241b57287521f459c9ef2e54acfa4ba9c4e07
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/815a2cdfe027baca05a32e5137a660f1_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:0c8a40a0eceb7eee78dc4058204b22220d4a7b4dccb1506861490dfe4cb8d761
+size 707
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/8592a32c2fdf17c1e562f0ba6b7e8e1a_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/8592a32c2fdf17c1e562f0ba6b7e8e1a_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..5e8fdb626e9b93c7bcd98f8848b6bad60b306937
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/8592a32c2fdf17c1e562f0ba6b7e8e1a_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:1b9d648fd7ffa3a861b1df7a9e358d05ef00ff257fd42c426b876224f7139bed
+size 24463
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/85dc87c4d6b2ffb31f32d942ae086e7e_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/85dc87c4d6b2ffb31f32d942ae086e7e_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..8edf6a3fa4e4f2a0c25537307e310e5878f30b4d
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/85dc87c4d6b2ffb31f32d942ae086e7e_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:164931937d60848734cf71e757a5beb0532c4db304ff00dc0413ae2a8b59044c
+size 1676
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/8c348bf9c2c81b018017ae1d19506a9a_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/8c348bf9c2c81b018017ae1d19506a9a_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..21464e50401777561253b0de7a60aa5b4639d163
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/8c348bf9c2c81b018017ae1d19506a9a_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:267938d4197c1742104f4ce338dd3bd61d8692f82f87ae3be1e6d944b06ae4ec
+size 127648
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/8c4e956a7a4cad37d2870d90bc35a336_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/8c4e956a7a4cad37d2870d90bc35a336_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..f357cb2ed5b1f9db59c23c5018b6c9233517d198
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/8c4e956a7a4cad37d2870d90bc35a336_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:d6fa70e07944183320efa35a0be1cab4605c959dba42023fc8ba072abd32c244
+size 1696
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/8e156a047ab39437397ce794a544bd17_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/8e156a047ab39437397ce794a544bd17_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..db77ea7ad04d5cde4654e24f950e13da6e8066c4
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/8e156a047ab39437397ce794a544bd17_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:09289b5e7858de0e049abb13729702290264114b4ea79b8d3357bfb0bba0c7fd
+size 1052
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/9004864120b210d910c922954e0a6373_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/9004864120b210d910c922954e0a6373_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..de972a01e1d1078d14d24f8321394e5c4e652160
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/9004864120b210d910c922954e0a6373_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:cfa5316b441c251895bb602c3ddd64e096d8e189fec133a5e8afde143008c0e7
+size 1388
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/90e239638905cfb5c40eee128202d108_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/90e239638905cfb5c40eee128202d108_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..0c52069ae637ce4bb29d4dd206af45e45aea5b6a
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/90e239638905cfb5c40eee128202d108_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:c18c5656c67dd66baea2d9be42bbd7d32154b558a904e95cdb99736d3ab09f22
+size 894
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/91e829e819bd452379ef45a3266c77ff_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/91e829e819bd452379ef45a3266c77ff_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..f4a77a7e4a1c25626dc7a1bb21d7ff774741a8a9
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/91e829e819bd452379ef45a3266c77ff_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:73ad62bafc3c20c5adeaf847162398f67e0331d3be58629f70d5ce199ed387df
+size 707
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/925e9ce6c680535b457aec8c2bc4e0cb_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/925e9ce6c680535b457aec8c2bc4e0cb_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..9bce474b611a2745dd8c568ee52dfe2208e8890a
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/925e9ce6c680535b457aec8c2bc4e0cb_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:620bfd41fd0fbd4fbebe62525d224ffde7b0936b90270578c473fc56f49ba205
+size 1332
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/936338b1a73120f5096018bc86e40356_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/936338b1a73120f5096018bc86e40356_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..164135164d7884a1fbb762829fc47a73cbf281bd
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/936338b1a73120f5096018bc86e40356_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:c5a766d380666e6d48dd4df8323643ed80315f9ebdab8af8fdfaccda4ce3e9e8
+size 1021
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/96a4ab6b889d10c56fa094fc517573b2_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/96a4ab6b889d10c56fa094fc517573b2_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..e588ea2a4a748e953c28bc3d68526adae0cb2236
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/96a4ab6b889d10c56fa094fc517573b2_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:b3421a060eb0a773038cbc81a80ad5541c0d253578bb1df9e597acfbcbae7f55
+size 1663
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/9707f376b5a29ee0a7cf4f673d63a902_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/9707f376b5a29ee0a7cf4f673d63a902_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..5d3f847eaca174f0cb2a3dafe313df2f242e0ea1
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/9707f376b5a29ee0a7cf4f673d63a902_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:b5494f2ed8bb14a68ce413470ca7d5ea9232a3897bacc3925b8a8d5d7f563286
+size 1112
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/974c48c36a8cb4b1e9ff82cbc656c995_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/974c48c36a8cb4b1e9ff82cbc656c995_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..e24974a265802666732d86e8a24d5192e7482202
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/974c48c36a8cb4b1e9ff82cbc656c995_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:3aaf7d0374f2efebf5c083e5c58053ecc4352c5decd0167e4d6b4427af3db08c
+size 1033
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/9822b8b860d2cb301de35f397f8b0ab9_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/9822b8b860d2cb301de35f397f8b0ab9_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..8e3dde691a8685c637835332512d8c5dd4a8bc2f
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/9822b8b860d2cb301de35f397f8b0ab9_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:3e0de0a8798a8d2201bf4c8aa6c8b326c49186fce47b64d387becb9cedefbb26
+size 1217
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/98339486ecdb0f33314b896d3ca1ab4f_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/98339486ecdb0f33314b896d3ca1ab4f_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..4433824d0bfa3ae3424f13411eccee706872fb51
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/98339486ecdb0f33314b896d3ca1ab4f_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:b08d588e4abc08d2a0d1acd5a6c00c046284925870f0dc65a9d378b4ab414b32
+size 707
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/9b26903dffaa763de6ddbe5a8ca444aa_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/9b26903dffaa763de6ddbe5a8ca444aa_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..f4a77a7e4a1c25626dc7a1bb21d7ff774741a8a9
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/9b26903dffaa763de6ddbe5a8ca444aa_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:73ad62bafc3c20c5adeaf847162398f67e0331d3be58629f70d5ce199ed387df
+size 707
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/9c6461e1e94afae4dec455e69a2ce152_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/9c6461e1e94afae4dec455e69a2ce152_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..6f55498e5f9d2a80a763344b6c23361b6bfa2b6e
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/9c6461e1e94afae4dec455e69a2ce152_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:f38044247796fe1d159756d007eaa8d9556df4c5457aaec91e4bbf3c0deccbe2
+size 103847
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/9c7a9be314bb1d951105ac4d678e0f02_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/9c7a9be314bb1d951105ac4d678e0f02_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..20be3ad803dcf56060867f11b29567081cac21ac
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/9c7a9be314bb1d951105ac4d678e0f02_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:0bf8f0f38a12dbb74ee16ed08ffba43270053831731dd80b67ab615fa4a69f27
+size 1387
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/9f40834a5eb0f5daec3af0d2431fd115_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/9f40834a5eb0f5daec3af0d2431fd115_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..e1ce32e3c10255e2c30be6d734b4095527ceeb8c
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/9f40834a5eb0f5daec3af0d2431fd115_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:0cb1b2df05a2a3636dce8cbe9850d07399578a018f607581463d8f05ac536aec
+size 1296
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/a231ce96b7d5cce760e3b0bd94abf8ab_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/a231ce96b7d5cce760e3b0bd94abf8ab_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..c6bf90ff933f1f960e529942dacc11a6154e646f
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/a231ce96b7d5cce760e3b0bd94abf8ab_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:edf7259da32b5d61fb7b68b3d10b3ba9822ffc85ebf9f0bde0d3536f657201ff
+size 1202
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/a99b7ca0c2723b8f2db01659527c60ca_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/a99b7ca0c2723b8f2db01659527c60ca_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..7475587a03048d6efd5a97a89a970c4d92481de7
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/a99b7ca0c2723b8f2db01659527c60ca_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:6e7b9dca3d3b9b474f6dadccba3cbb99b18b5e2130e9b3ff646192bcc297336b
+size 1496
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/aaf3e6e44cdeabd6d1df869c5f392ea1_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/aaf3e6e44cdeabd6d1df869c5f392ea1_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..de900ddc74a13d44c64ea5804d8d79f04be3b14d
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/aaf3e6e44cdeabd6d1df869c5f392ea1_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:83c6b2d93e2cd153fea72a74a3f2501ac43ee77c3ff64a0a8df9bca223dd4429
+size 125099
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/ae857726e074ccb5764dd8cc8f5892c3_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/ae857726e074ccb5764dd8cc8f5892c3_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..d4a7129582017a8a4d746214e7ef1f1b8d33fa8f
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/ae857726e074ccb5764dd8cc8f5892c3_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:8077161a3236ce0fe46cf32a8fc0da858a877d172ff60c6e2076e86a7f07e1a1
+size 1084
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/ae9ca05e57c7a297eb97f5b8be4a5260_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/ae9ca05e57c7a297eb97f5b8be4a5260_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..23069f65807af22fcb4a3796dfe7783e68047b42
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/ae9ca05e57c7a297eb97f5b8be4a5260_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:6c06e461fb7d90ef4adaf574c1c8593211bb5554b2dfdf39ea0e9dd4fdbda658
+size 1707
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/af7916c89a458fdab6c3f443217388ae_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/af7916c89a458fdab6c3f443217388ae_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..c37fb514a4626b3167e3cbd8a7b6268f3789a265
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/af7916c89a458fdab6c3f443217388ae_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:e6d3a2052e07744eebede1f56f3ae6353ed261eeb8ab57b51cb0bc15c46320dc
+size 15671
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/afcd7568ab58413667e41adb4a4b3366_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/afcd7568ab58413667e41adb4a4b3366_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..b66a7efd28d8689090d1c4a24b94dc424cc50ab5
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/afcd7568ab58413667e41adb4a4b3366_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:a65bdb72e031d952c19b9820aed89af2f3e3f8cbebc3f70ea7c097666f3d277b
+size 1340
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/b245d26892acd965489c846391fadd52_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/b245d26892acd965489c846391fadd52_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..a91628021b71a40cd528df32b304f2f7472e79e9
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/b245d26892acd965489c846391fadd52_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:2fb77e4d34a6ec10a1def017f750a4b2be1a4605f1bfac2db0083e98112fd68c
+size 1135
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/b2884d52e79773fc0720732ed1cb9fa9_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/b2884d52e79773fc0720732ed1cb9fa9_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..550988cf6276350518c95ea4aca10e8d78507a1f
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/b2884d52e79773fc0720732ed1cb9fa9_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:6c5560dde9bad3d403bfba6aacebb7fda495f92bd14011b06e9789571a3622b5
+size 1170
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/b3254f7c02b1b41a97c3a1782c993320_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/b3254f7c02b1b41a97c3a1782c993320_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..09427696189c9cae7575bb86e5adccaf5c95b12b
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/b3254f7c02b1b41a97c3a1782c993320_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:4e78a0534a6bca921c3859baa250862457677a5323aa09558b81b44b0618750c
+size 1180
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/b63cf0c3448d17a13ce1150e63f288ea_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/b63cf0c3448d17a13ce1150e63f288ea_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..4965ce999fd27b218da271b0093e3da373d8ee49
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/b63cf0c3448d17a13ce1150e63f288ea_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:ce8a5ee17f14065326c7a8c82170a5e6c0a2a6e4b4b372ea07000b9b364e23ae
+size 1624
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/b64b01e49de87ca72acf4eff6e656ea5_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/b64b01e49de87ca72acf4eff6e656ea5_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..5517d2e5afa0b41243e38d91761f018603bda784
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/b64b01e49de87ca72acf4eff6e656ea5_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:e744c29ba58427da30bc40cf6a1c972fc4a0d224169ebc3524a1ae8dd476d5a7
+size 1127
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/b6b4e39bd7d2e47e69a5109695db5885_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/b6b4e39bd7d2e47e69a5109695db5885_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..9f6241b57287521f459c9ef2e54acfa4ba9c4e07
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/b6b4e39bd7d2e47e69a5109695db5885_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:0c8a40a0eceb7eee78dc4058204b22220d4a7b4dccb1506861490dfe4cb8d761
+size 707
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/b965770921c96b5317b4eede2f54af1e_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/b965770921c96b5317b4eede2f54af1e_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..463b9821c4e617ed51beb4c25e99a7de7c1539d3
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/b965770921c96b5317b4eede2f54af1e_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:9e194ecd25068bf226dcae0997360239635ab89ea27e0b93a59d4bac4f1dedf8
+size 924
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/bd54fdaf1368502ad721794928a7c150_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/bd54fdaf1368502ad721794928a7c150_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..6968ad28f526a9b234b538864af7aabcba289a81
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/bd54fdaf1368502ad721794928a7c150_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:83fef25c89415bc9732699857599492131eb79ea52cb12d12dd9ac12e341004f
+size 986
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/bf5d84368ff955dde79533bc9e3e80e6_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/bf5d84368ff955dde79533bc9e3e80e6_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..311c660f667152e68cb59aac01baa95fd15431df
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/bf5d84368ff955dde79533bc9e3e80e6_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:a5b2c9a59faf4559193156ca7d94b9e3cbd8b7295f37e40cfab0f9cbfbbdc299
+size 1730
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/c03a680787ce303b15441da085e5b608_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/c03a680787ce303b15441da085e5b608_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..c9423071531bb5c1e5459b17e40b65ff49b31cfd
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/c03a680787ce303b15441da085e5b608_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:389025993972b8fd870b817f5ff2db3319ec0e7f2f8e421dfb302050e54e3fe3
+size 1601
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/c06fd7dbef68a8b788158f2081d9d734_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/c06fd7dbef68a8b788158f2081d9d734_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..2d723d0a42ed7f6bf36dbcf73a1187a85b0aa8db
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/c06fd7dbef68a8b788158f2081d9d734_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:d84cff9536200d0ca487c0949aacbf79b0ed574de6431d766a7a1e70f26177ed
+size 17555
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/c0f64806753a053854921deb8f4fc798_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/c0f64806753a053854921deb8f4fc798_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..31f36a44b1c195c6fbc224f8302e60bf5a9acda4
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/c0f64806753a053854921deb8f4fc798_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:21cb9cda7ea7ed8fafb0a8c980c78c8236486ad29e73ac7b37f8b6fb691a22e5
+size 29813
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/c1ea687d485a0cdddc0899002dc67b0f_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/c1ea687d485a0cdddc0899002dc67b0f_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..17b8f41673dc4e714a768d978bee3638c33442aa
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/c1ea687d485a0cdddc0899002dc67b0f_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:d54cd6504f1b878a7b5ba9d3c0b0eccf8b7fc1b62274a508ddeec60ecf26c7b3
+size 971
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/c22114491c8aa9afa1c4d76b3d8de08d_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/c22114491c8aa9afa1c4d76b3d8de08d_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..54d6c90d8f84e34867a3c4b39a0abe2f0b4fbfa0
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/c22114491c8aa9afa1c4d76b3d8de08d_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:e2d98a137da04c3f2c0028dd546d59ec757a000c2619c5e7078e99b3912f475a
+size 1037
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/c3b87a761eaec5959dd75beea28e011b_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/c3b87a761eaec5959dd75beea28e011b_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..b64b063ef10782fed4f9d49f2fa90070578a8622
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/c3b87a761eaec5959dd75beea28e011b_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:17f81cc2aaba9160f962fbeb30fb4ff8ab0667224a3ecb17fbbe51d536bde877
+size 826
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/c4acc0bcdb9595f0c8d0a3ea1e294137_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/c4acc0bcdb9595f0c8d0a3ea1e294137_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..d5bdc0ea8032d2591ee79fe40ba8cb8b01194ccc
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/c4acc0bcdb9595f0c8d0a3ea1e294137_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:91d15a568c1abe5be12ac216d26690d9a23a9a22dfae13a2160f41f8f4718792
+size 1455
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/c5452f95f3b28f1bfe29e84fbc2e1267_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/c5452f95f3b28f1bfe29e84fbc2e1267_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..8528c09c7701981e2ff6968c533f713e7378f5a3
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/c5452f95f3b28f1bfe29e84fbc2e1267_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:3a4754b30973562ed5ccaac6be57c637ae0bb5446e4e1a33b1d41bfb8b0dd4fe
+size 41147
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/c72ee5099b8b45da185da3d27cde6537_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/c72ee5099b8b45da185da3d27cde6537_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..2124d98186a5308508c87d21e67671786abcab60
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/c72ee5099b8b45da185da3d27cde6537_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:faddb7358e0b82f9cf04a4b3365899f1c1e8175e7d1e7cd478567ab5d3391f72
+size 1222
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/c818de50a70ab5bdf8e6dbf90c8e0b25_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/c818de50a70ab5bdf8e6dbf90c8e0b25_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..ba1d514249bf6aecc4a1973de3df341297eb5740
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/c818de50a70ab5bdf8e6dbf90c8e0b25_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:237ea963155bac5d29a738744599019f10333568a33f83d4f7022458b001439c
+size 1580
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/c914f51f4427bc672dd0526cfc90ebe9_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/c914f51f4427bc672dd0526cfc90ebe9_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..1af978dea45a38e3c7c94500e214ea4a181bce7c
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/c914f51f4427bc672dd0526cfc90ebe9_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:54edfe74d1e0979f83e76e1cc3aeaca675c0945764db4c265bbd47366b1a71a1
+size 38729
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/caa0e00102ffa02c3c844f3bd01d2710_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/caa0e00102ffa02c3c844f3bd01d2710_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..41dc17df922b94b79f80f418db82b6383155fd63
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/caa0e00102ffa02c3c844f3bd01d2710_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:c00d1c0ab091569459aa1dcdd8f72b6fb08e9ba7e5e3da9e60a6a7a8c8c0b731
+size 1696
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/cb864ba6e7a13c850a20311c434cde1d_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/cb864ba6e7a13c850a20311c434cde1d_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..f680111bfd806d1816c8954e2f6eb3ae6e6df7db
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/cb864ba6e7a13c850a20311c434cde1d_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:83958049207770ac2d87f94b28aee86261bac693e30769757754b9a1b4b3cd4b
+size 1360
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/cb8dd5eca74bbf15a81e37c23263c9a8_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/cb8dd5eca74bbf15a81e37c23263c9a8_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..8ad26b4d7d9ccd52a162859ad6342b9e10e28bd2
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/cb8dd5eca74bbf15a81e37c23263c9a8_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:6b0ed4da2179dd07a3ab0b28ec7b8df624fbbe59ada4b296655c1ff26537c159
+size 22086
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/d05106a4684960f3d7747196ecd48868_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/d05106a4684960f3d7747196ecd48868_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..56fc1d453c12eb8ba7f334778a90769fe4049746
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/d05106a4684960f3d7747196ecd48868_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:60b4995637ae1ad4244cc818ff0f5a9c7e75e52407a2324c982dfb96532f170c
+size 1004
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/d080bb3f1bc0e19b51c309e8d27a17d9_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/d080bb3f1bc0e19b51c309e8d27a17d9_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..f9a2ebe0fad0bfcea0f9b65bca342c446628da68
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/d080bb3f1bc0e19b51c309e8d27a17d9_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:de86085cbfe0697b930c29282c0e98ad989b8287853e621d231613f0b85b3ec2
+size 1001
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/d1461890f3b8035d9f2dba94a9c652f4_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/d1461890f3b8035d9f2dba94a9c652f4_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..bb75aeb4577cf7377d7c30c94aeadc2b95b90f6f
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/d1461890f3b8035d9f2dba94a9c652f4_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:6cd5502731e9d93ef657b70398165c0cdeb315d595773c29baed107e44d58524
+size 1113
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/d1c76b0c89a39c0a946b784f19232bc3_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/d1c76b0c89a39c0a946b784f19232bc3_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..f931862f0843b29354b935b0eb2272faea7fff04
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/d1c76b0c89a39c0a946b784f19232bc3_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:d6a790439a11cf5a5dd314649c5b1e8c64acd09a05054b4d8d8c6d180a8ce9d9
+size 1915
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/d6ac74d4ce5afbfbe46eeb84c2cf448c_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/d6ac74d4ce5afbfbe46eeb84c2cf448c_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..b41efee098c878cd45e02394053822cecf6bceff
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/d6ac74d4ce5afbfbe46eeb84c2cf448c_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:10875914ec50fa0918d0cbd3ee764f29ff3dd510f485aaebac266043b0e13693
+size 1051
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/d734a6ea1b381280f043fcf70391b6db_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/d734a6ea1b381280f043fcf70391b6db_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..939e9d1e0465eb59b067dbaa83d4ad7501009831
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/d734a6ea1b381280f043fcf70391b6db_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:9efcac2d4640d53074b78b00b699e979f4760d72a70960c18d4fb4e53300819f
+size 47044
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/d806e2fe6a362ebc9b6eee5179aafe73_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/d806e2fe6a362ebc9b6eee5179aafe73_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..48b48be103b063d563220b1bf8aa8a49d642e977
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/d806e2fe6a362ebc9b6eee5179aafe73_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:87fc0c6c15d66b49e3eba4a9ccff06ad19e11b3c2655878a727596ea64b5ffa5
+size 1661
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/db37526a5e6981ee69137fa99be4faca_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/db37526a5e6981ee69137fa99be4faca_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..d89d0f18a1e44d63521b690561541339e52f52cc
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/db37526a5e6981ee69137fa99be4faca_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:d84a874860f73eb9d3ddaf77c0195b71bc27a90599cab0420a34aacbec2edd8b
+size 1064
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/dbf1c57c53837d15b39a8cd1817f4214_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/dbf1c57c53837d15b39a8cd1817f4214_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..4829dc05007f694df52c3e309622b9272bb3cd3b
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/dbf1c57c53837d15b39a8cd1817f4214_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:1ae97a8a47fcc83a3bc0e92a6d570ad95b0fce1e816e766ae6e2e8a56e06bfd4
+size 926
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/dc37a040cf9e2add7488c7c37cbf3687_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/dc37a040cf9e2add7488c7c37cbf3687_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..748a53ba5ed18697d0da742303cb3b6e825d7a6b
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/dc37a040cf9e2add7488c7c37cbf3687_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:b2d974a773977e085a6d877939482aeff2d34c662a9b859afe699d1d20f8a6ec
+size 25948
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/df81aa6f5798d6e90bf888390f46feca_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/df81aa6f5798d6e90bf888390f46feca_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..5ab1b15807e0af534e8efec7533226130847f6c0
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/df81aa6f5798d6e90bf888390f46feca_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:77ba5eeddc1a95ffa1102fd7bb4df1900b760054a799bbdc7021b67e56a7f3ea
+size 1449
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/e180f2b5fcbe8001554a7c0677cd3f82_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/e180f2b5fcbe8001554a7c0677cd3f82_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..b349149a4bd19134684762af91f73e6fa5dfbb21
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/e180f2b5fcbe8001554a7c0677cd3f82_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:4ac95b3d420ff7735f1bc699d35b02f29421477dff928d8051ee2b85b47f1db2
+size 26122
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/e2b4b910d83f757642a7484c1eea65bb_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/e2b4b910d83f757642a7484c1eea65bb_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..b6d68613b0214c7fd58d39157d9b283d99e7b514
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/e2b4b910d83f757642a7484c1eea65bb_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:18c5502f2fa35a56400c0e4b820e4b42ed0044144c6d7e75ef8e09f115b931b6
+size 1235
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/e3d8b06a332cb0481b0eca139315a760_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/e3d8b06a332cb0481b0eca139315a760_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..e28af44e8dcfedbe75701101c15786a976d5dd96
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/e3d8b06a332cb0481b0eca139315a760_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:d36bda2602dd16e96283a54282bed0415fc490bd26a5f22bce817e7f27a3e50b
+size 1364
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/e6ebd43aba4035106ae0c967b96af905_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/e6ebd43aba4035106ae0c967b96af905_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..abf41f8ad0d3d5e201d0f0025bdd1a479580acae
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/e6ebd43aba4035106ae0c967b96af905_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:6bebfaa7746917c21811634762dfed35c194ecfe9fd85e7742c97bd61837f994
+size 1060
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/e7aeb80519a3d81e8e7390e4aad5e7eb_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/e7aeb80519a3d81e8e7390e4aad5e7eb_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..d09a333a2b0c8051c1c079458a4f245088bfceab
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/e7aeb80519a3d81e8e7390e4aad5e7eb_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:2022d5df70b3454bc8a189ad38c4e74451445593f77715cb629dbfaa3df017f9
+size 1036
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/ec12485963a75a47df8f078c83cc00c9_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/ec12485963a75a47df8f078c83cc00c9_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..19dacc6a600e971564994d880e7efa14229b9697
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/ec12485963a75a47df8f078c83cc00c9_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:51c3de0683f26d9c494919cc7496358dc6d1bbffc189b0ea574f15279d10c3ea
+size 1183
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/ed33858e10de69ce2f952b267e7b972f_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/ed33858e10de69ce2f952b267e7b972f_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..105ba1cdf070037f944a97f35e0a095fff94c16a
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/ed33858e10de69ce2f952b267e7b972f_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:bbb13f38cf264c45c526be44e4a6eed4ef5164f08828bb00066329742049eeef
+size 1619
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/ee63febff1ca59020d69a870622804f7_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/ee63febff1ca59020d69a870622804f7_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..8f8f5040f0c8adada39127d4cd2eec5c06acadf7
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/ee63febff1ca59020d69a870622804f7_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:979d8f8d67c624209f9e24e946c7a637896d05aad6b9de882e3b0d83e18fd4f1
+size 1001
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/eeee55835a191946eeca66d5587398b1_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/eeee55835a191946eeca66d5587398b1_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..8cc615a552d5ba7c9f214eb8bed23c78e869a3c5
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/eeee55835a191946eeca66d5587398b1_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:8b99f37b25ec5d506ce7e3a3bb0ac756a923fb80e39cb59faffd7a466bddc422
+size 1340
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/f193d824c546073b910c43d33bd72adf_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/f193d824c546073b910c43d33bd72adf_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..3d06c410133293faa896506aea2b73be232c66bc
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/f193d824c546073b910c43d33bd72adf_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:65fa92018c9cdbe36dd79faca0c828d71ebb2366581393e0b2d400b50bb78a55
+size 853
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/f1f0f46a3b66c8fcf142dfba8afe3041_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/f1f0f46a3b66c8fcf142dfba8afe3041_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..7a70bf2a18d2e89850d8eaeb2cb537d8764e2de5
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/f1f0f46a3b66c8fcf142dfba8afe3041_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:f1467deb2c2ce645c26bc652f8e3356fa5def484c98ed177cff78057562f9416
+size 1088
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/f3e52020770cccaad4f731a0c989d20d_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/f3e52020770cccaad4f731a0c989d20d_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..9f6241b57287521f459c9ef2e54acfa4ba9c4e07
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/f3e52020770cccaad4f731a0c989d20d_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:0c8a40a0eceb7eee78dc4058204b22220d4a7b4dccb1506861490dfe4cb8d761
+size 707
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/f56279472b70f6ba64434c6d4a4f35b6_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/f56279472b70f6ba64434c6d4a4f35b6_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..c32bf2b24bf6c004eeaccbed512149189c50c2e8
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/f56279472b70f6ba64434c6d4a4f35b6_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:6132d31c801f453856cf8aa158e8d141e6456554947a5f86ddd848b28d748dc1
+size 1010
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/f6cc4587343c65df8268abb6b31f50b4_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/f6cc4587343c65df8268abb6b31f50b4_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..01eaf0f8ed9f0e97eb1ea21db279bf02fa83e056
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/f6cc4587343c65df8268abb6b31f50b4_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:f8739c4c643cd4e93a3b305c34994577996860ead2e95dd040157f80173215f3
+size 1138
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/f9c64800d9bace9b4315646d1057be3c_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/f9c64800d9bace9b4315646d1057be3c_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..2509d3cbe6719fd8a005717b3fd82762fd5e555b
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/f9c64800d9bace9b4315646d1057be3c_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:ef2d4538a7f714c22bc5f8d721a8cb2fe97a12dcda71793467add500e304a6c6
+size 116250
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/f9dfb387910065e909dfd3b231cdc184_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/f9dfb387910065e909dfd3b231cdc184_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..f4a77a7e4a1c25626dc7a1bb21d7ff774741a8a9
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/f9dfb387910065e909dfd3b231cdc184_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:73ad62bafc3c20c5adeaf847162398f67e0331d3be58629f70d5ce199ed387df
+size 707
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/fed4a04822c24fb22cca3a14f4ddae83_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/fed4a04822c24fb22cca3a14f4ddae83_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..67facb27b368d2e731ae6e35f27e1ef94c3103f3
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/fed4a04822c24fb22cca3a14f4ddae83_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:95058e3f480a0e889da34db7a718f1ce98f1303bd4ee83a9469e4053a4a2eeb8
+size 29019
diff --git a/marked/T/T-REC-T.4-200307-I_PDF-E/ffbc261d7c38efbe14f04a941f087051_img.jpg b/marked/T/T-REC-T.4-200307-I_PDF-E/ffbc261d7c38efbe14f04a941f087051_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..9f6241b57287521f459c9ef2e54acfa4ba9c4e07
--- /dev/null
+++ b/marked/T/T-REC-T.4-200307-I_PDF-E/ffbc261d7c38efbe14f04a941f087051_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:0c8a40a0eceb7eee78dc4058204b22220d4a7b4dccb1506861490dfe4cb8d761
+size 707
diff --git a/marked/T/T-REC-T.42-200307-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/T/T-REC-T.42-200307-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..939eb6a57fac47a375526475ba6c31bf67e08b30
--- /dev/null
+++ b/marked/T/T-REC-T.42-200307-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:52a289bbb49d106b16f646b5050f62e5c7cbe1bb201f8c767547c3039abbf359
+size 8245
diff --git a/marked/T/T-REC-T.421-199411-I_PDF-E/043e64d41a3368d138ace3816fd26469_img.jpg b/marked/T/T-REC-T.421-199411-I_PDF-E/043e64d41a3368d138ace3816fd26469_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..3a105f761bd8e237cc60be07d7f0ca1eb466e162
--- /dev/null
+++ b/marked/T/T-REC-T.421-199411-I_PDF-E/043e64d41a3368d138ace3816fd26469_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:28f2004adf77df44bfb7f3928f10b51ddb61e7b73f15159b7a14177f32e7bcb0
+size 27331
diff --git a/marked/T/T-REC-T.421-199411-I_PDF-E/06b83e9b87612260a1221a69827ba169_img.jpg b/marked/T/T-REC-T.421-199411-I_PDF-E/06b83e9b87612260a1221a69827ba169_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..b335f638d7a00bd28cad037c7fe7f9e936389031
--- /dev/null
+++ b/marked/T/T-REC-T.421-199411-I_PDF-E/06b83e9b87612260a1221a69827ba169_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:da885fac52026a823a3cef18032784baaa52a514cf41830ce0a7f23737a9c0d0
+size 45613
diff --git a/marked/T/T-REC-T.421-199411-I_PDF-E/08a978a124d3ed6cf1a3d0cfd89418d0_img.jpg b/marked/T/T-REC-T.421-199411-I_PDF-E/08a978a124d3ed6cf1a3d0cfd89418d0_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..8009f791448c7cfe77b4dac7d7a99abbb9e87ac9
--- /dev/null
+++ b/marked/T/T-REC-T.421-199411-I_PDF-E/08a978a124d3ed6cf1a3d0cfd89418d0_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:b7fefcee49c0e378737b450ab3e2836fad401c36f37a9d9b71f094471f7cc717
+size 62865
diff --git a/marked/T/T-REC-T.421-199411-I_PDF-E/0c08e48c08f96934cd6bc6911f3069dc_img.jpg b/marked/T/T-REC-T.421-199411-I_PDF-E/0c08e48c08f96934cd6bc6911f3069dc_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..9c0aec31a2c727e0afd17d1c3c4b084221c3b2c8
--- /dev/null
+++ b/marked/T/T-REC-T.421-199411-I_PDF-E/0c08e48c08f96934cd6bc6911f3069dc_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:4296b8047b5fb2fba95b233c22552d4475280596f701eae36b5c218bf55eafdc
+size 35891
diff --git a/marked/T/T-REC-T.421-199411-I_PDF-E/1d62ade6b682fdfb8e192d10a06246a4_img.jpg b/marked/T/T-REC-T.421-199411-I_PDF-E/1d62ade6b682fdfb8e192d10a06246a4_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..81baec69f7828c87ac66ef093421211755e31ba5
--- /dev/null
+++ b/marked/T/T-REC-T.421-199411-I_PDF-E/1d62ade6b682fdfb8e192d10a06246a4_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:4d4f995a6206348a1bf4125574a5416c161c64784a28932141977c15ab06e171
+size 202422
diff --git a/marked/T/T-REC-T.421-199411-I_PDF-E/255efa1d461fc79b4ed367aaec11637f_img.jpg b/marked/T/T-REC-T.421-199411-I_PDF-E/255efa1d461fc79b4ed367aaec11637f_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..e2d503a3a0c6a3a14ed5b60ff6a37d0f0bce53d0
--- /dev/null
+++ b/marked/T/T-REC-T.421-199411-I_PDF-E/255efa1d461fc79b4ed367aaec11637f_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:ac17064c145ad66273c1df15745554856ae1676ccda6cc623bc3c3856c53b9f6
+size 65605
diff --git a/marked/T/T-REC-T.421-199411-I_PDF-E/26299f7378ec209838cd016923e68290_img.jpg b/marked/T/T-REC-T.421-199411-I_PDF-E/26299f7378ec209838cd016923e68290_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..4d4c8cdddf6be54d40c2d87e4d8358d6c0ed460c
--- /dev/null
+++ b/marked/T/T-REC-T.421-199411-I_PDF-E/26299f7378ec209838cd016923e68290_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:5d08184df4347f00470fe5d92acfa8942bd09b48bd031884a745796b107fa964
+size 25931
diff --git a/marked/T/T-REC-T.421-199411-I_PDF-E/26d664119ad25250780f554633444e54_img.jpg b/marked/T/T-REC-T.421-199411-I_PDF-E/26d664119ad25250780f554633444e54_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..d93b3e0df340c6bb48f7299266619d23f1874de9
--- /dev/null
+++ b/marked/T/T-REC-T.421-199411-I_PDF-E/26d664119ad25250780f554633444e54_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:82b9d697968c5f85e20a8042d7a8038c240760c714e7ddd50f8d24e64c4e3244
+size 68126
diff --git a/marked/T/T-REC-T.421-199411-I_PDF-E/2c41e286ea9a1b008d3beb348d86096f_img.jpg b/marked/T/T-REC-T.421-199411-I_PDF-E/2c41e286ea9a1b008d3beb348d86096f_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..19a38b98cf948a978b14d80465fc8d25215a7231
--- /dev/null
+++ b/marked/T/T-REC-T.421-199411-I_PDF-E/2c41e286ea9a1b008d3beb348d86096f_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:34774f34affac11baab5dcaeb7cfeb4c03dd03e4e41c11afe24f71e2a12700d1
+size 54554
diff --git a/marked/T/T-REC-T.421-199411-I_PDF-E/2d548db0b26b7bf33244320322d5ee2c_img.jpg b/marked/T/T-REC-T.421-199411-I_PDF-E/2d548db0b26b7bf33244320322d5ee2c_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..aa2b727faa6fa51818ea986ed1d45a8c0846e16f
--- /dev/null
+++ b/marked/T/T-REC-T.421-199411-I_PDF-E/2d548db0b26b7bf33244320322d5ee2c_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:8265f0e87b32882f178980acd7485a5588f05bae474b3d3fee0f8f86c7eabe98
+size 129211
diff --git a/marked/T/T-REC-T.421-199411-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/T/T-REC-T.421-199411-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..2d07bb5021b582b84454339297eb9aae5cd4fb86
--- /dev/null
+++ b/marked/T/T-REC-T.421-199411-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:12aa712315a77106657a20345afe7c2733ba88964a92409312343c7f8c6c27f7
+size 8357
diff --git a/marked/T/T-REC-T.421-199411-I_PDF-E/3334fcca5dac808f4fd3840aba35bc2e_img.jpg b/marked/T/T-REC-T.421-199411-I_PDF-E/3334fcca5dac808f4fd3840aba35bc2e_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..d1a5580c185c2c25233d2f5585601492dfc6ff54
--- /dev/null
+++ b/marked/T/T-REC-T.421-199411-I_PDF-E/3334fcca5dac808f4fd3840aba35bc2e_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:3f4a808b8bb81ef609e924ad95fecb30581f7b4c526f67e387f8cee56e0f3d1b
+size 12016
diff --git a/marked/T/T-REC-T.421-199411-I_PDF-E/396b969fe671a6ae5f086506b9c29718_img.jpg b/marked/T/T-REC-T.421-199411-I_PDF-E/396b969fe671a6ae5f086506b9c29718_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..63b239f2f9229d9fadc9b830846f38c4cc87defa
--- /dev/null
+++ b/marked/T/T-REC-T.421-199411-I_PDF-E/396b969fe671a6ae5f086506b9c29718_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:b11446255d1c8c4764e9c3e85272137137efa7b964c7937ca88cbc563b67cc3e
+size 51651
diff --git a/marked/T/T-REC-T.421-199411-I_PDF-E/4ae4505e885586e481a3ad3bff5198b7_img.jpg b/marked/T/T-REC-T.421-199411-I_PDF-E/4ae4505e885586e481a3ad3bff5198b7_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..ff8d63b1507e6b72d5ec36773cfd2b8676e6276e
--- /dev/null
+++ b/marked/T/T-REC-T.421-199411-I_PDF-E/4ae4505e885586e481a3ad3bff5198b7_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:d42ee16a56710f0fa87c672d0ede55031050f5e046c85bceb21656c2c775c464
+size 61412
diff --git a/marked/T/T-REC-T.421-199411-I_PDF-E/4e85fe330de2c4f5eea6de4b2a53c77f_img.jpg b/marked/T/T-REC-T.421-199411-I_PDF-E/4e85fe330de2c4f5eea6de4b2a53c77f_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..7f3e293d9b51ee8263bc66566491d5aeac100439
--- /dev/null
+++ b/marked/T/T-REC-T.421-199411-I_PDF-E/4e85fe330de2c4f5eea6de4b2a53c77f_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:49adda8dc4aa61432c0d381eced8dd6ca01485bd9a564022b042667a4466d132
+size 27100
diff --git a/marked/T/T-REC-T.421-199411-I_PDF-E/52fe5bc3ba967e0e8f56f1a3ab9d9c3e_img.jpg b/marked/T/T-REC-T.421-199411-I_PDF-E/52fe5bc3ba967e0e8f56f1a3ab9d9c3e_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..873bbaa0bf5a8dc2c660677f91136825f48301b9
--- /dev/null
+++ b/marked/T/T-REC-T.421-199411-I_PDF-E/52fe5bc3ba967e0e8f56f1a3ab9d9c3e_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:1bb285340b9c40c232e44307eefbac422b26314f87997c7bd069de8299c01efa
+size 58746
diff --git a/marked/T/T-REC-T.421-199411-I_PDF-E/5509e6ec160899dd306e462bb6a3643b_img.jpg b/marked/T/T-REC-T.421-199411-I_PDF-E/5509e6ec160899dd306e462bb6a3643b_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..9e37ce5a17a67783aed2ee6c3b7405f1c02db41c
--- /dev/null
+++ b/marked/T/T-REC-T.421-199411-I_PDF-E/5509e6ec160899dd306e462bb6a3643b_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:9bb05e11033ad8ecddf790de94505c1c56ed881a6f640edcd472c4c4b4a3b1c0
+size 61728
diff --git a/marked/T/T-REC-T.421-199411-I_PDF-E/649d03e4c5c42598e91826f372146f65_img.jpg b/marked/T/T-REC-T.421-199411-I_PDF-E/649d03e4c5c42598e91826f372146f65_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..7c10c390d60dbbcf2de57e2bb6381bc742ee2570
--- /dev/null
+++ b/marked/T/T-REC-T.421-199411-I_PDF-E/649d03e4c5c42598e91826f372146f65_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:32460f18979b0bc1f827e73c747e8020f3271f480ac5b9109c6af9f8d402b615
+size 105965
diff --git a/marked/T/T-REC-T.421-199411-I_PDF-E/73b5cce955ba9415a98791db7b0080ad_img.jpg b/marked/T/T-REC-T.421-199411-I_PDF-E/73b5cce955ba9415a98791db7b0080ad_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..abebb74826d6b6270a3a4c07d051a3f4fb0221bb
--- /dev/null
+++ b/marked/T/T-REC-T.421-199411-I_PDF-E/73b5cce955ba9415a98791db7b0080ad_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:48ace38944da4d7c6a19bc8b05b25f90ab2e6ba7813ada6e7055be021d50b97d
+size 103175
diff --git a/marked/T/T-REC-T.421-199411-I_PDF-E/7b8b192e2853ef28d28eff0241ebe86b_img.jpg b/marked/T/T-REC-T.421-199411-I_PDF-E/7b8b192e2853ef28d28eff0241ebe86b_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..d602431ce568f84d361b007518c007235c295fe3
--- /dev/null
+++ b/marked/T/T-REC-T.421-199411-I_PDF-E/7b8b192e2853ef28d28eff0241ebe86b_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:b59459d93ff38515948e40432647c4e8995d3a71d52f5cb0c938e7d05834170e
+size 46323
diff --git a/marked/T/T-REC-T.421-199411-I_PDF-E/7d929ba1b7d09ea8e00b9e7abbbe50c9_img.jpg b/marked/T/T-REC-T.421-199411-I_PDF-E/7d929ba1b7d09ea8e00b9e7abbbe50c9_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..def7f6fa88b2ffbfb76dd40ffbbf94061c6f9f9d
--- /dev/null
+++ b/marked/T/T-REC-T.421-199411-I_PDF-E/7d929ba1b7d09ea8e00b9e7abbbe50c9_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:e3e533518d191cd7092b10a2de0714247d3ffaddf4caeac5b6d5dd8917ff2556
+size 86839
diff --git a/marked/T/T-REC-T.421-199411-I_PDF-E/812e188283162af0b54fb3e30ffee51b_img.jpg b/marked/T/T-REC-T.421-199411-I_PDF-E/812e188283162af0b54fb3e30ffee51b_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..095aa38f6461135e1ea03016f2a7a38d493e5a9a
--- /dev/null
+++ b/marked/T/T-REC-T.421-199411-I_PDF-E/812e188283162af0b54fb3e30ffee51b_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:baf06d716962b99bd19d3346572559b3c1d06d535c5c06adb51df60e5ceff3b7
+size 30431
diff --git a/marked/T/T-REC-T.421-199411-I_PDF-E/9cb54072e43a6b6717eb16036a7640a2_img.jpg b/marked/T/T-REC-T.421-199411-I_PDF-E/9cb54072e43a6b6717eb16036a7640a2_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..e9dc3e88280b6f453061a7a7edc38d5c909b6f77
--- /dev/null
+++ b/marked/T/T-REC-T.421-199411-I_PDF-E/9cb54072e43a6b6717eb16036a7640a2_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:3ed1cdf25a5d72985afc1f518b4b87955572994f1c6624a5ac326116124e8afd
+size 54269
diff --git a/marked/T/T-REC-T.421-199411-I_PDF-E/a003ffe7299e0a48bceb7f1e45a4f1a3_img.jpg b/marked/T/T-REC-T.421-199411-I_PDF-E/a003ffe7299e0a48bceb7f1e45a4f1a3_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..cc899dc0e5d2b3c4dae772197899011b4aa1451a
--- /dev/null
+++ b/marked/T/T-REC-T.421-199411-I_PDF-E/a003ffe7299e0a48bceb7f1e45a4f1a3_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:ad71786c6d6d661cfca5c6b459c94a40d8532546a480a5ff9e24df58397c7967
+size 40909
diff --git a/marked/T/T-REC-T.421-199411-I_PDF-E/ae57a92114d2bd84ef81129e7fbdd89d_img.jpg b/marked/T/T-REC-T.421-199411-I_PDF-E/ae57a92114d2bd84ef81129e7fbdd89d_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..ded97ad2eb288a1791ce08178a7ef5d3cb9b76f4
--- /dev/null
+++ b/marked/T/T-REC-T.421-199411-I_PDF-E/ae57a92114d2bd84ef81129e7fbdd89d_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:9cd6fa67cbf8410f4f2364febe8f50eadb6780bcf8827c2a27ff861864eb0725
+size 36650
diff --git a/marked/T/T-REC-T.421-199411-I_PDF-E/aed5b156b9b0fff9167baba88e5fdcfc_img.jpg b/marked/T/T-REC-T.421-199411-I_PDF-E/aed5b156b9b0fff9167baba88e5fdcfc_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..8f883224204fbba4d7885b00f558f780c1987ebe
--- /dev/null
+++ b/marked/T/T-REC-T.421-199411-I_PDF-E/aed5b156b9b0fff9167baba88e5fdcfc_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:3ef53d4715a7efed42ba513341d9925f1f303e3514765ff4bcc96e5043dd400b
+size 78695
diff --git a/marked/T/T-REC-T.421-199411-I_PDF-E/af3b2fa532cb9b02a2aaeeb49e0118d0_img.jpg b/marked/T/T-REC-T.421-199411-I_PDF-E/af3b2fa532cb9b02a2aaeeb49e0118d0_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..0bd83cf328db2f1df6ebb9c2496b454932a85bb7
--- /dev/null
+++ b/marked/T/T-REC-T.421-199411-I_PDF-E/af3b2fa532cb9b02a2aaeeb49e0118d0_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:ea1bde04a018935567b713327da6430b6fb81b33fe650aef91084194363b8827
+size 95844
diff --git a/marked/T/T-REC-T.421-199411-I_PDF-E/bf316d14a760a28869460fd9b0c9f616_img.jpg b/marked/T/T-REC-T.421-199411-I_PDF-E/bf316d14a760a28869460fd9b0c9f616_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..855fff740176348318100b52098800ef36f55a7d
--- /dev/null
+++ b/marked/T/T-REC-T.421-199411-I_PDF-E/bf316d14a760a28869460fd9b0c9f616_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:bbc01329c877df465c2284549cfe22e734524cf09545c9da063a407c851c7687
+size 107411
diff --git a/marked/T/T-REC-T.421-199411-I_PDF-E/c0ca823603794512478906b302176bca_img.jpg b/marked/T/T-REC-T.421-199411-I_PDF-E/c0ca823603794512478906b302176bca_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..a4d317898cf033088598d2d6f13c5bfc5bc00ab2
--- /dev/null
+++ b/marked/T/T-REC-T.421-199411-I_PDF-E/c0ca823603794512478906b302176bca_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:b9688bfc5969211177d7b02696cbb71e609331be40bd05dc3acbb8b45a21e7d4
+size 46853
diff --git a/marked/T/T-REC-T.421-199411-I_PDF-E/cf4ac1058c52bc3ca37737740afb7f2c_img.jpg b/marked/T/T-REC-T.421-199411-I_PDF-E/cf4ac1058c52bc3ca37737740afb7f2c_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..1dbfe12f999989a4a54f58ef4e7ee826dc337191
--- /dev/null
+++ b/marked/T/T-REC-T.421-199411-I_PDF-E/cf4ac1058c52bc3ca37737740afb7f2c_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:5eae29aecd6367d850c4da0ab5c3936399c7c6ed5d32a9403a535ed7247c8016
+size 45218
diff --git a/marked/T/T-REC-T.421-199411-I_PDF-E/dbfe5a97dc7e71fd9ae813d4bb865e29_img.jpg b/marked/T/T-REC-T.421-199411-I_PDF-E/dbfe5a97dc7e71fd9ae813d4bb865e29_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..a55b997d22f94a58578872f3e16f18c94f7fb07b
--- /dev/null
+++ b/marked/T/T-REC-T.421-199411-I_PDF-E/dbfe5a97dc7e71fd9ae813d4bb865e29_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:c7dd1af90ca80dc69d6ab227062f179635e120189f31b11d3b8cf9b5cc0c6391
+size 104958
diff --git a/marked/T/T-REC-T.421-199411-I_PDF-E/e26bb66586e464339df27951d5c9355e_img.jpg b/marked/T/T-REC-T.421-199411-I_PDF-E/e26bb66586e464339df27951d5c9355e_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..313f439e1288b531afb04f44bf554a9ce2c66464
--- /dev/null
+++ b/marked/T/T-REC-T.421-199411-I_PDF-E/e26bb66586e464339df27951d5c9355e_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:169e57cef4db11eb2275f0e63e87de92c6cf89b8673cdb0580bdacade8f234ad
+size 37686
diff --git a/marked/T/T-REC-T.421-199411-I_PDF-E/e5ded249943a879ef58cae5b6b87c576_img.jpg b/marked/T/T-REC-T.421-199411-I_PDF-E/e5ded249943a879ef58cae5b6b87c576_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..672a0714561640f5b553e80a5a85f08ab0e1a0e5
--- /dev/null
+++ b/marked/T/T-REC-T.421-199411-I_PDF-E/e5ded249943a879ef58cae5b6b87c576_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:02b3e8533fe4e65f540a3d9aa444392c80ff3d62e5834297774b1eb34fd8ec2e
+size 63324
diff --git a/marked/T/T-REC-T.421-199411-I_PDF-E/e9f6a9e6beb9ae97b392bf38b93ad748_img.jpg b/marked/T/T-REC-T.421-199411-I_PDF-E/e9f6a9e6beb9ae97b392bf38b93ad748_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..727d4d4cd3405d0051a2b4a9800b79c1ec5883b0
--- /dev/null
+++ b/marked/T/T-REC-T.421-199411-I_PDF-E/e9f6a9e6beb9ae97b392bf38b93ad748_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:a031c47b2ff019f577dfde91182d1bf4fe5e8eb42a5b60d7fbb294548d6204e7
+size 104549
diff --git a/marked/T/T-REC-T.421-199411-I_PDF-E/raw.md b/marked/T/T-REC-T.421-199411-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..7c8c901995ccbc89bf8b326c7fb93a602d3cb88a
--- /dev/null
+++ b/marked/T/T-REC-T.421-199411-I_PDF-E/raw.md
@@ -0,0 +1,6749 @@
+
+
+![ITU logo: A globe with the letters ITU inside, and a lightning bolt symbol.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg)
+
+ITU logo: A globe with the letters ITU inside, and a lightning bolt symbol.
+
+INTERNATIONAL TELECOMMUNICATION UNION
+
+# ITU-T
+
+TELECOMMUNICATION  
+STANDARDIZATION SECTOR  
+OF ITU
+
+## T.421
+
+(11/94)
+
+# TERMINALS FOR TELEMATIC SERVICES ---
+
+# INFORMATION TECHNOLOGY – OPEN DOCUMENT ARCHITECTURE (ODA) AND INTERCHANGE FORMAT: TABULAR STRUCTURES AND TABULAR LAYOUT
+
+## ITU-T Recommendation T.421
+
+(Previously “CCITT Recommendation”)
+
+---
+
+ITU (International Telecommunication Union) is the United Nations Specialized Agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the ITU. Some 179 member countries, 84 telecom operating entities, 145 scientific and industrial organizations and 38 international organizations participate in ITU-T which is the body which sets world telecommunications standards (Recommendations).
+
+The approval of Recommendations by the Members of ITU-T is covered by the procedure laid down in WTSC Resolution No. 1 (Helsinki, 1993). In addition, the World Telecommunication Standardization Conference (WTSC), which meets every four years, approves Recommendations submitted to it and establishes the study programme for the following period.
+
+In some areas of information technology, which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. The text of ITU-T Recommendation T.421 was approved on 11th of November 1994. The identical text is also published as ISO/IEC International Standard 8613-11.
+
+# --- NOTE
+
+In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+# CONTENTS
+
+|                                                                                          | <i>Page</i> |
+|------------------------------------------------------------------------------------------|-------------|
+| List of Figures .....                                                                    | v           |
+| List of Tables.....                                                                      | vi          |
+| Summary.....                                                                             | vii         |
+| Foreword .....                                                                           | viii        |
+| 1 Scope.....                                                                             | 1           |
+| 2 Normative references .....                                                             | 2           |
+| 2.1 Identical Recommendations   International Standards .....                            | 2           |
+| 2.2 Paired Recommendations   International Standards equivalent in technical terms ..... | 2           |
+| 3 Definitions.....                                                                       | 2           |
+| 4 Abbreviations .....                                                                    | 4           |
+| 5 Conventions.....                                                                       | 4           |
+| 5.1 Content associated with a composite logical object.....                              | 4           |
+| 5.2 The symbol / .....                                                                   | 4           |
+| 6 Relationship to ITU-T Recommendation T.412   ISO/IEC 8613-2.....                       | 5           |
+| 7 Features of tabular structures and tabular layout.....                                 | 5           |
+| 7.1 Content types and inner structures of table entries .....                            | 6           |
+| 7.2 Dimensions of tables, rows and columns .....                                         | 6           |
+| 7.3 Placement of tables .....                                                            | 6           |
+| 7.4 Spanning cells .....                                                                 | 6           |
+| 7.5 Placement of table entries .....                                                     | 6           |
+| 7.5.1 Gutter space around table lines .....                                              | 6           |
+| 7.5.2 Offset of table entries.....                                                       | 7           |
+| 7.5.3 Alignment of a table entry within a table cell .....                               | 7           |
+| 7.5.4 Reference line alignment .....                                                     | 7           |
+| 7.6 Split of tables .....                                                                | 7           |
+| 7.6.1 Direction of table split.....                                                      | 7           |
+| 7.6.2 Repetition of headings .....                                                       | 7           |
+| 7.7 Rendition of table lines .....                                                       | 8           |
+| 7.8 Supplementary lines.....                                                             | 8           |
+| 8 Grid logical components .....                                                          | 8           |
+| 8.1 Logical grids .....                                                                  | 8           |
+| 8.1.1 Logical grid lines and logical grid locations .....                                | 8           |
+| 8.1.2 Major and minor paths .....                                                        | 8           |
+| 8.1.3 Major and minor logical grid lines.....                                            | 8           |
+| 8.1.4 Major and minor sizes of a logical grid .....                                      | 9           |
+| 8.1.5 Logical coordinates .....                                                          | 9           |
+| 8.1.6 Logical grid rectangles.....                                                       | 9           |
+| 8.2 Association of entry objects with logical grid rectangles .....                      | 9           |
+| 9 Grid frame components.....                                                             | 10          |
+| 9.1 Layout grid.....                                                                     | 11          |
+| 9.1.1 Layout grid lines .....                                                            | 11          |
+| 9.1.2 Major and minor paths .....                                                        | 11          |
+| 9.1.3 Major and minor layout grid lines.....                                             | 11          |
+| 9.1.4 Grid line segments .....                                                           | 13          |
+| 9.1.5 Major and minor sizes of a layout grid .....                                       | 13          |
+| 9.1.6 Major and minor dimensions of a layout grid.....                                   | 13          |
+
+|         | <i>Page</i>                                                                        |
+|---------|------------------------------------------------------------------------------------|
+| 9.1.7   | Grid intervals, layout grid locations and layout grid rectangles ..... 13          |
+| 9.1.8   | Dimensions of grid intervals ..... 14                                              |
+| 9.1.9   | Naming of edges of a layout grid rectangle ..... 15                                |
+| 9.1.10  | Grid gutter spaces ..... 16                                                        |
+| 9.1.11  | Position of a layout grid ..... 16                                                 |
+| 9.1.12  | Minimal layout of a layout grid ..... 17                                           |
+| 9.2     | Association of grid frames with grid logical objects ..... 17                      |
+| 9.3     | Binding of entry frames to layout grid rectangles ..... 17                         |
+| 9.3.1   | Correspondence between layout grid lines and logical grid lines ..... 18           |
+| 9.3.2   | Correspondence between layout grid rectangles and logical grid rectangles ..... 18 |
+| 9.3.3   | Layout of content associated with entry objects ..... 18                           |
+| 10      | Duplication of content ..... 18                                                    |
+| 10.1    | Reproductions of content ..... 18                                                  |
+| 10.1.1  | Reproductions of the content of a basic logical object ..... 18                    |
+| 10.1.2  | Reproductions of the content of a target object ..... 19                           |
+| 10.1.3  | Reproduction bundles ..... 19                                                      |
+| 10.2    | Layout of content within reproductions ..... 19                                    |
+| 10.2.1  | Order of layout ..... 19                                                           |
+| 10.2.2  | Splits of content portions ..... 19                                                |
+| 10.2.3  | Effects of layout directive attributes on layout ..... 20                          |
+| 10.3    | Content identifiers for reproductions ..... 22                                     |
+| 11      | Expressions ..... 22                                                               |
+| 11.1    | Grid construction expressions ..... 22                                             |
+| 11.2    | Attributes with grid construction expressions as values ..... 23                   |
+| 11.3    | Grid interval expressions ..... 24                                                 |
+| 11.4    | Interval indicators ..... 24                                                       |
+| 11.5    | Grid gutter expressions ..... 26                                                   |
+| 11.6    | Gutter indicators ..... 27                                                         |
+| 11.7    | Grid line expressions ..... 27                                                     |
+| 11.8    | Line characteristics ..... 27                                                      |
+| 11.9    | Line characteristic expressions ..... 28                                           |
+| 11.10   | Line segment characteristics ..... 28                                              |
+| 12      | Attribute definitions ..... 29                                                     |
+| 12.1    | Layout attributes ..... 29                                                         |
+| 12.1.1  | Frame alignment point ..... 29                                                     |
+| 12.1.2  | Grid dimensions ..... 31                                                           |
+| 12.1.3  | Grid gutters ..... 31                                                              |
+| 12.1.4  | Grid interval dimensions ..... 33                                                  |
+| 12.1.5  | Grid lines ..... 34                                                                |
+| 12.1.6  | Grid position ..... 36                                                             |
+| 12.1.7  | Indent – major; ..... 38                                                           |
+|         | Indent – minor ..... 38                                                            |
+| 12.1.8  | Major path ..... 40                                                                |
+| 12.1.9  | Minor path ..... 40                                                                |
+| 12.1.10 | Position ..... 40                                                                  |
+| 12.1.11 | Reference line alignment – major; ..... 47                                         |
+|         | Reference line alignment – minor ..... 47                                          |
+| 12.1.12 | Supplementary lines ..... 51                                                       |
+| 12.2    | Layout directive attributes ..... 52                                               |
+| 12.2.1  | Block alignment point ..... 52                                                     |
+| 12.2.2  | Grid description ..... 53                                                          |
+| 12.2.3  | Grid frame classes ..... 55                                                        |
+
+|                                                                           | <i>Page</i>                                                                             |
+|---------------------------------------------------------------------------|-----------------------------------------------------------------------------------------|
+| 12.2.4                                                                    | Obligatory same layout objects..... 55                                                  |
+| 12.2.5                                                                    | Presentation precedence..... 57                                                         |
+| 12.2.6                                                                    | Selective same layout objects..... 59                                                   |
+| 12.2.7                                                                    | Supplementary line directive..... 60                                                    |
+| 12.3                                                                      | Presentation attributes..... 61                                                         |
+| 12.3.1                                                                    | Character content architecture ..... 61                                                 |
+| 12.3.2                                                                    | Raster graphics content architecture ..... 63                                           |
+| 12.3.3                                                                    | Geometric graphics content architecture..... 63                                         |
+| 13                                                                        | Reference model of the document layout process with respect to tabular layout ..... 65  |
+| 13.1                                                                      | Layout of reproductions of content..... 65                                              |
+| 13.2                                                                      | Layout reference from a grid logical object to grid frames..... 65                      |
+| 13.3                                                                      | Determination of the dimensions of layout grids..... 66                                 |
+| 13.3.1                                                                    | Constraints on the dimensions of layout grids ..... 66                                  |
+| 13.3.2                                                                    | Minimal layout of the layout grid ..... 66                                              |
+| 13.4                                                                      | Determination of the imaging factors of table lines..... 67                             |
+| 13.5                                                                      | Processing order of basic logical objects ..... 67                                      |
+| 13.6                                                                      | Placement of an entry frame not bound to a grid rectangle ..... 68                      |
+| 13.7                                                                      | Placement of an entry frame bound to a grid rectangle..... 68                           |
+| 13.7.1                                                                    | Determination of the area available for placement of entry frames ..... 68              |
+| 13.7.2                                                                    | Placement of an entry frame within its available area..... 75                           |
+| 13.7.3                                                                    | Placement of temporarily positioned entry frames..... 78                                |
+| 13.7.4                                                                    | Rectification of position of entry frames with centre order ..... 79                    |
+| 14                                                                        | Reference model of the document imaging process with respect to tabular layout ..... 80 |
+| 14.1                                                                      | Generation of images of layout grid lines ..... 80                                      |
+| 14.1.1                                                                    | Direction of a grid line segment..... 80                                                |
+| 14.1.2                                                                    | Position and dimension of a grid line segment ..... 80                                  |
+| 14.1.3                                                                    | Imaging factors for a grid line segment ..... 81                                        |
+| 14.2                                                                      | Generation of images of supplementary lines..... 81                                     |
+| Annex A – Formal definition of tabular structures and tabular layout..... | 82                                                                                      |
+| A.1                                                                       | Layout descriptors..... 82                                                              |
+| A.2                                                                       | Logical descriptors..... 84                                                             |
+| A.3                                                                       | Style descriptors..... 84                                                               |
+| A.4                                                                       | Default value lists ..... 85                                                            |
+| A.5                                                                       | Character presentation attributes..... 85                                               |
+| A.6                                                                       | Raster graphics presentation attributes..... 86                                         |
+| A.7                                                                       | Geometric graphics presentation attributes..... 87                                      |
+| A.8                                                                       | Grid layout descriptors..... 87                                                         |
+| A.9                                                                       | Grid style descriptors ..... 90                                                         |
+| Annex B – Formal definition of tabular structures and tabular layout..... | 92                                                                                      |
+| B.1                                                                       | Example 1 ..... 92                                                                      |
+| B.1.1                                                                     | Generic Layout Structure ..... 92                                                       |
+| B.1.2                                                                     | Explanation ..... 94                                                                    |
+| B.2                                                                       | Example 2 ..... 95                                                                      |
+| B.2.1                                                                     | Generic Logical Structure ..... 95                                                      |
+| B.2.2                                                                     | Specific Logical Structure..... 96                                                      |
+| B.2.3                                                                     | Specific Layout Structure..... 97                                                       |
+| B.2.4                                                                     | Explanation ..... 100                                                                   |
+| B.3                                                                       | Example 3 ..... 104                                                                     |
+| B.3.1                                                                     | Generic Logical Structure ..... 104                                                     |
+| B.3.2                                                                     | Specific Logical Structure..... 104                                                     |
+| B.3.3                                                                     | Specific Layout Structure..... 106                                                      |
+| B.3.4                                                                     | Explanation ..... 108                                                                   |
+
+|                                       | <i>Page</i> |
+|---------------------------------------|-------------|
+| B.4 Example 4 .....                   | 110         |
+| B.4.1 Generic Logical Structure ..... | 110         |
+| B.4.2 Specific Logical Structure..... | 110         |
+| B.4.3 Explanation .....               | 111         |
+| B.5 Example 5 .....                   | 111         |
+| B.5.1 Generic Logical Structure ..... | 111         |
+| B.5.2 Specific Logical Structure..... | 112         |
+| B.5.3 Generic Layout Structure .....  | 118         |
+| B.5.4 Layout Style .....              | 119         |
+| B.5.5 Explanation .....               | 120         |
+| B.6 Example 6 .....                   | 121         |
+| B.6.1 Generic Logical Structure ..... | 121         |
+| B.6.2 Specific Logical Structure..... | 121         |
+| B.6.3 Generic Layout Structure .....  | 121         |
+| B.6.4 Layout Style .....              | 123         |
+| B.6.5 Explanation .....               | 124         |
+| B.7 Example 7 .....                   | 125         |
+| B.7.1 Generic Logical Structure ..... | 125         |
+| B.7.2 Layout Styles .....             | 126         |
+| B.7.3 Presentation Styles .....       | 127         |
+| B.7.4 Generic Layout Structure .....  | 127         |
+| B.7.5 Specific Logical Structure..... | 128         |
+| B.7.6 Explanation .....               | 128         |
+
+# List of Figures
+
+|                                                                                        | <i>Page</i> |
+|----------------------------------------------------------------------------------------|-------------|
+| 1 Logical grid .....                                                                   | 9           |
+| 2 Association of entry objects with logical grid rectangles.....                       | 10          |
+| 3 Layout grid .....                                                                    | 11          |
+| 4 Layout grid lines .....                                                              | 12          |
+| 5 Grid intervals.....                                                                  | 14          |
+| 6 Grid interval dimensions .....                                                       | 15          |
+| 7 Edges of grid rectangles .....                                                       | 16          |
+| 8 Grid origin and grid reference point.....                                            | 17          |
+| 9 Gutter spaces .....                                                                  | 32          |
+| 10 Grid origin and grid reference point.....                                           | 37          |
+| 11 Major alignment of grids .....                                                      | 38          |
+| 12 Indent – major .....                                                                | 39          |
+| 13 Example of first typical case of placement of entry frames with centre order .....  | 46          |
+| 14 Example of second typical case of placement of entry frames with centre order ..... | 46          |
+| 15 Quasi alignment groups.....                                                         | 48          |
+| 16 Alignment groups.....                                                               | 49          |
+| 17 Presentation of reference lines .....                                               | 50          |
+| 18 Processing order of basic logical objects .....                                     | 58          |
+| 19 Alignment points in the character content architecture .....                        | 62          |
+| 20 Alignment points in the raster graphics content architecture .....                  | 64          |
+| 21 Available area for an entry frame with normal order .....                           | 71          |
+
+|                                                              | <i>Page</i> |
+|--------------------------------------------------------------|-------------|
+| 22 Available area for an entry frame with centre order.....  | 72          |
+| 23 Available area for an entry frame with reverse order..... | 73          |
+| 24 Reference line alignment.....                             | 78          |
+| B.1 Generic Layout Structure of Example 1.....               | 93          |
+| B.2 Example 1.....                                           | 94          |
+| B.3 Generic Logical Structure of Example 2.....              | 95          |
+| B.4 Specific Structures of Example 2.....                    | 96          |
+| B.5 Formatted Table of Example 2.....                        | 96          |
+| B.6 Placement of Entry Frame within Grid Rectangle.....      | 97          |
+| B.7 Overflow of Table Contents.....                          | 109         |
+| B.8 Table with Raster Contents.....                          | 111         |
+| B.9 Generic Logical Structure of Example 5.....              | 112         |
+| B.10 Specific Logical Structure of Example 5.....            | 117         |
+| B.11 Layout of Example 5.....                                | 120         |
+| B.12 Indentation.....                                        | 121         |
+| B.13 Cut-in heads.....                                       | 125         |
+| B.14 Redundant duplication of table headings.....            | 126         |
+| B.15 Reference Line Alignment.....                           | 128         |
+
+# List of Tables
+
+|                                                            | <i>Page</i> |
+|------------------------------------------------------------|-------------|
+| 1 Types of grid construction expression.....               | 23          |
+| 2 Positions of grid origins and grid reference points..... | 37          |
+
+# Summary
+
+This Recommendation | International Standard:
+
+- defines a document architecture, in order to allow presentation and processing of tabular material, that can be used in conjunction with the document architecture defined in Recommendation T.412 (1993);
+- defines two types of components, the grid logical component and the grid frame component, which are characterized by association with grids;
+- defines the layout attributes and layout directive attributes, in order to allow representation of tabular layout, applicable to this document architecture;
+- defines the presentation attributes, in order to allow presentation of tabular layout, applicable to the content architectures defined in Recommendation T.416 (1993), Recommendation T.417 (1993) and Recommendation T.418 (1993);
+- describes reference models of the document layout process and the document imaging process which, together with the document processing model described in Recommendation T.412 (1993), determine representation and presentation of tabular layout.
+
+# Foreword
+
+This Recommendation | International Standard was prepared as a joint publication by ITU Study Group 8 and ISO/IEC Joint Technical Committee 1.
+
+At present, the ITU-T Set of Recommendations in the T.410-Series | International Standard ISO/IEC 8613 consists of:
+
+- Introduction and general principles;
+- Document structures;
+- Document profile;
+- Open document interchange formats;
+- Character content architectures;
+- Raster graphics content architectures;
+- Geometric graphics content architectures;
+- Formal specification of the Open Document Architecture (FODA)
+
+(The formal specification is applicable to ISO/IEC 8613 only.)
+
+Further Recommendations | International Standards may be added to this series of ITU-T Recommendations | International Standards.
+
+Development of this series of ITU-T Recommendations | International Standards was originally in parallel with the ECMA 101 standard: *Open Document Architecture*.
+
+This series of ITU-T Recommendations | International Standards is a new edition of the CCITT T.410-Series of Recommendations (1988) and ISO 8613 (1989).
+
+Significant technical changes are the inclusion of the following amendments as agreed by ITU and ISO/IEC:
+
+- Alternative Representation;
+- Annex on use of MHS/MOTIS;
+- Colour;
+- Conformance Testing Annex;
+- Document Application Profile, Proforma and Notation;
+- Security;
+- Streams;
+- Styles;
+- Tiled Raster Graphics.
+
+In addition, a number of technical corrigenda have been applied to this Recommendation | International Standard.
+
+This ITU-T Recommendation | International Standard contains two annexes:
+
+- Annex A – Formal definition of tabular structures and tabular layout.
+- Annex B – Examples.
+
+
+
+## INTERNATIONAL STANDARD
+
+## ITU-T RECOMMENDATION
+
+# INFORMATION TECHNOLOGY – OPEN DOCUMENT ARCHITECTURE (ODA) AND INTERCHANGE FORMAT: TABULAR STRUCTURES AND TABULAR LAYOUT
+
+# 1 Scope
+
+The purpose of the ITU-T Recommendation T.410-Series | ISO/IEC 8613 is to facilitate the interchange of documents.
+
+In the context of these Recommendations | International Standards, documents are considered to be items such as memoranda, letters, invoices, forms and reports, which may include pictures and tabular material. The content elements used within the documents may include graphic characters, raster graphic elements and geometric graphic elements, all potentially within one document.
+
+NOTE – These Recommendations | International Standards are designed to allow for extensions, including typographical features, colour, spreadsheets and additional types of content such as sound.
+
+In addition to the content type defined in these Recommendations | International Standards, ODA also provides for arbitrary content types to be included in documents.
+
+These Recommendations | International Standards apply to the interchange of documents by means of data communications or the exchange of storage media.
+
+These Recommendations | International Standards provide for the interchange of documents for either or both of the following purposes:
+
+- to allow presentation as intended by the originator;
+- to allow processing, such as editing and reformatting.
+
+The composition of a document in interchange can take several forms:
+
+- formatted form, allowing presentation of the document;
+- processable form, allowing processing of the document;
+- formatted processable form, allowing both presentation and processing.
+
+These Recommendations | International Standards also provide for the interchange of ODA information structures used for the processing of interchanged documents.
+
+This Recommendation | International Standard:
+
+- defines a document architecture, in order to allow presentation and processing of tabular material, that can be used in conjunction with the document architecture defined in ITU-T Recommendation T.412 | ISO/IEC 8613-2;
+- defines two types of components, the grid logical component and the grid frame component, which are characterized by association with grids;
+- defines the layout attributes and layout directive attributes, in order to allow representation of tabular layout, applicable to this document architecture;
+- defines the presentation attributes, in order to allow presentation of tabular layout, applicable to the content architectures defined in ITU-T Recommendation T.416 | ISO/IEC 8613-6, ITU-T Recommendation T.417 | ISO/IEC 8613-7, and ITU-T Recommendation T.418 | ISO/IEC 8613-8;
+- describes reference models of the document layout process and the document imaging process which, together with the document processing model described in ITU-T Recommendation T.412 | ISO/IEC 8613-2, determine representation and presentation of tabular layout.
+
+# 2 Normative references
+
+The following ITU-T Recommendations and International Standards contain provisions which, through references, in this text, constitute provisions of this Recommendation | International Standard. At the time of publication, the editions indicated were valid. All Recommendations and Standards are subject to revision, and parties to agreements based on
+
+this Recommendation | International Standard are encouraged to investigate the possibility of applying the most recent edition of the Recommendations and Standards listed below. Members of IEC and ISO maintain registers of currently valid International Standards. The Telecommunication Standardization Bureau of the ITU maintains a list of currently valid ITU-T Recommendations.
+
+## 2.1 Identical Recommendations | International Standards
+
+- ITU-T Recommendation T.411 (1993) | ISO/IEC 8613-1:1994, *Information technology – Open Document Architecture (ODA) and interchange format: Introduction and general principles.*
+- ITU-T Recommendation T.412 (1993) | ISO/IEC 8613-2:1995, *Information technology – Open Document Architecture (ODA) and interchange format: Document structures.*
+- ITU-T Recommendation T.414 (1993) | ISO/IEC 8613-4:1994, *Information technology – Open Document Architecture (ODA) and interchange format: Document profile.*
+- ITU-T Recommendation T.415 (1993) | ISO/IEC 8613-5:1994, *Information technology – Open Document Architecture (ODA) and interchange format: Open document interchange format.*
+- ITU-T Recommendation T.417 (1993) | ISO/IEC 8613-7:1994, *Information technology – Open Document Architecture (ODA) and interchange format: Raster graphics content architectures.*
+- ITU-T Recommendation T.418 (1993) | ISO/IEC 8613-8:1994, *Information technology – Open Document Architecture (ODA) and interchange format: Geometric graphics content architectures.*
+
+## 2.2 Paired Recommendations | International Standards equivalent in technical terms
+
+- CCITT Recommendation X.208 (1988), *Specification of Abstract Syntax Notation One (ASN.1).*  
+ISO/IEC 8824:1990, *Information technology – Open Systems Interconnection – Specification of Abstract Syntax Notation One (ASN.1).*
+- CCITT Recommendation X.209 (1988), *Specification of basic encoding rules for Abstract Syntax Notation One (ASN.1).*  
+ISO/IEC 8825:1990, *Information technology – Open Systems Interconnection – Specification of Basic Encoding Rules for Abstract Syntax Notation One (ASN.1).*
+
+# 3 Definitions
+
+In addition to the definitions given in ITU-T Recommendation T.411 | ISO/IEC 8613-1, the definitions listed below apply to this Recommendation | International Standard.
+
+NOTE – The use of the symbol / is described in 5.2.
+
+**3.1 dimensions of a layout grid:** The height and width of the *layout grid*, measured in scaled measurement units (SMU).
+
+**3.2 entry frame:** An immediately subordinate frame to a *grid frame* which is variably positioned within the superior grid frame.
+
+**3.3 entry frame bound to a layout grid rectangle:** An *entry frame* which is to be laid out within the layout grid rectangle to which it is bound.
+
+**3.4 entry object:** A logical object such that its association with some *logical grid* rectangle within some logical grid is specified.
+
+**3.5 entry object occupying a logical grid rectangle:** An *entry object* such that its association with this logical grid rectangle is specified.
+
+**3.6 grid frame:** A frame which is characterized by the capability to include a *layout grid* within it.
+
+**3.7 grid frame component:** A variant of the composite layout component of frame type which is identified by the value ‘grid frame’ specified for the attribute “object type”.
+
+**3.8 grid gutter space:** A reserved area around a *layout grid line* from which entry frames are excluded.
+
+**3.9 grid gutter space width:** The distance between the bordering lines of a *grid gutter space*, measured in scaled measurement units (SMU).
+
+**3.10 grid interval:** An interval between two adjacent *layout grid lines* which are parallel to each other.
+
+- 3.11 grid interval dimension:** The distance between two adjacent *layout grid lines* in the same direction, measured in scaled measurement units (SMU).
+- 3.12 grid line:** A line forming part of a *logical grid* or *layout grid*, which runs parallel to one of the edges of the grid that includes it.
+- 3.13 grid logical component:** A variant of the composite logical component which is identified by the value 'grid logical' specified for the attribute "object type".
+- 3.14 grid logical object:** A composite logical object which is characterized by its association with a *logical grid*.
+- 3.15 *i*-th major / minor grid interval:** The interval between the (*i* – 1)-th and *i*-th *major / minor layout grid lines*.
+- 3.16 *i*-th major / minor layout grid line:** The *major / minor layout grid line* to which the ordinal number *i* is assigned.  
+NOTE – The numbering scheme is described in 9.1.3.
+- 3.17 *i*-th major / minor logical grid line:** The *major / minor logical grid line* to which the ordinal number *i* is assigned.  
+NOTE – The numbering scheme is described in 8.1.3.
+- 3.18 layout grid:** A rectangular area within a *grid frame* divided by two sets of parallel *layout grid lines* into one or more *layout grid locations*.
+- 3.19 layout grid line:** A line forming part of a *layout grid* which runs parallel to one of the edges of the layout grid.
+- 3.20 layout grid location:** A rectangle within a *layout grid* bounded by two pairs of adjacent *layout grid lines*.
+- 3.21 layout grid rectangle:** A rectangle composed of one or more *layout grid locations* within a *layout grid*.
+- 3.22 logical grid:** A rectangular area associated with a *grid logical object*, divided by two sets of parallel *logical grid lines* into one or more *logical grid locations*.
+- 3.23 logical grid line:** A line forming part of a *logical grid* which runs parallel to one of the edges of the logical grid.
+- 3.24 logical grid location:** A rectangle within a *logical grid* bounded by two pairs of adjacent *logical grid lines*.
+- 3.25 logical grid rectangle:** A rectangle composed of one or more *logical grid locations* within a *logical grid*.
+- 3.26 major / minor dimension of a layout grid:** The length, measured in scaled measurement units (SMU), of the edges of the *layout grid* which are parallel to the *major / minor path*.
+- 3.27 major / minor grid interval:** An interval between adjacent *major / minor layout grid lines*.
+- 3.28 major / minor layout grid line:** A *layout grid line* running parallel to the *minor / major path of the layout grid* that includes it.
+- 3.29 major / minor logical grid line:** A *logical grid line* running parallel to the *minor / major path of the logical grid* that includes it.
+- 3.30 major path:** A direction within a *logical grid* or *layout grid* parallel to one of the edges of the grid.
+- 3.31 major / minor size of a layout grid:** The largest number assigned to a *major / minor layout grid line* within the layout grid.
+- 3.32 major / minor size of a logical grid:** The largest number assigned to a *major / minor logical grid line* within the logical grid.
+- 3.33 minor path:** A direction within a *logical grid* or *layout grid* orthogonal to the *major path* within the same grid.
+- 3.34 reproduction of contents:** A set of one or more content portion descriptions which are reproductions of the content portion descriptions associated with basic logical objects, except that they never include the attribute "content identifier – logical".
+
+# 4 Abbreviations
+
+No abbreviations are defined in this Specification.
+
+# 5 Conventions
+
+In addition to the conventions given in ITU-T Recommendation T.411 | ISO/IEC 8613-1, the following conventions are used throughout this Specification.
+
+## 5.1 Content associated with a composite logical object
+
+The *content associated with a basic logical object* refers to a collection of content portions which are referred to by the attribute “content portions” specified for the basic logical object. If a content portion is associated with a basic logical object, then the content portion description always includes the attribute “content identifier – logical”.
+
+If the layout process duplicates the content associated with a basic logical object, one or more content portions are generated (see clause 10). Those content portions, as a whole, form part of a single and complete reproduction of the source content except for their identification attributes. In particular, they never include the attribute “content identifier – logical”. Hence, those content positions shall not be associated with any basic logical object, even though their source content is associated with the basic logical object.
+
+The *content associated with a composite logical object* refers to the union of the content associated with the basic logical objects which are, not necessarily immediately, subordinate to the composite logical object.
+
+More shortly, the phrase *the content of a logical object* may be used to refer to the content associated with the logical object, whether the logical object is basic or composite.
+
+## 5.2 The symbol /
+
+The symbol / between two words indicates that the two words surrounding the symbol / are two alternatives: each alternative makes the sentence including the alternatives true.
+
+When the symbol / appears in texts, this occurrence of the symbol has its own scope. Unless a NOTE specifies a particular scope for it, its scope is confined to the paragraph that includes this occurrence of the symbol.
+
+If the scope includes more than one occurrence of /, and if the reader selects the first alternative at the first occurrence, the text in the scope makes sense when he selects the first alternative at each subsequent occurrence throughout the scope. In the same way, if the reader selects the second alternative at the first occurrence, the text in the scope makes sense when he selects the second alternative at each subsequent occurrence throughout the scope.
+
+**Example:** If the reader selects the first/second alternative at the first occurrence, the text in the scope makes sense when he selects the first/second alternative at each subsequent occurrence throughout the scope.
+
+# 6 Relationship to ITU-T Recommendation T.412 | ISO/IEC 8613-2
+
+This Specification provides a document architecture that can be used in conjunction with the document architecture defined in ITU-T Recommendation T.412 | ISO/IEC 8613-2.
+
+This Specification defines 14 layout attributes, 7 layout directive attributes and 3 presentation style attributes. These attributes are defined so that they may represent documents including tabular structures and tabular layout, in both their logical and layout aspects, in conjunction with a number of attributes defined in ITU-T Recommendation T.412 | ISO/IEC 8613-2.
+
+The layout directive attributes:
+
+- obligatory same layout objects;
+- selective same layout objects,
+
+impose constraints on the document layout process additional to the layout directive attributes defined in ITU-T Recommendation T.412 | ISO/IEC 8613-2, without affecting their definitions.
+
+This Specification defines two additional object types, *grid logical components* and *grid frame components*.
+
+The layout directive attributes:
+
+- grid descriptions;
+- grid frame classes;
+- presentation precedence;
+- supplementary line directive,
+
+are specifiable only for grid logical components.
+
+The attributes “grid descriptions” and “grid frame classes” are for control of the placement of variably positioned frames within immediately superior grid frames. They never affect the definitions of any layout directive attributes defined in ITU-T Recommendation T.412 | ISO/IEC 8613-2.
+
+The attribute “presentation precedence” is for control of the order in which the document layout process lays out basic logical objects. This attribute may affect such layout directive attributes as “same layout object” and “concatenation”, whose definitions depend on the sequential logical order in specific logical structures. The conjunction of the attribute “presentation precedence” and such attributes may result in unexpected layout, unless the originator generates documents taking interaction between these attributes into consideration.
+
+The attribute “supplementary line directive” is for control of the imaging process to image supplementary lines within grid frames in addition to ordinary grid lines. It never affects the definitions of any layout directive attributes defined in ITU-T Recommendation T.412 | ISO/IEC 8613-2.
+
+This Specification defines a set of particular rules to determine position and dimensions of frames which are immediately subordinate to grid frames. For other frames, the rules defined in ITU-T Recommendation T.412 | ISO/IEC 8613-2 are valid without any changes.
+
+The rest of the attributes defined in this Specification are for the representation of these positioning and dimensioning rules for frames. In particular, the attribute “position” is re-defined in this Specification so that it may provide necessary functions to control placement of frames within immediately superior grid frames.
+
+# 7 Features of tabular structures and tabular layout
+
+This clause provides a description of the chief features of tabular structures and tabular layout which are in the scope of the document architecture defined in this Specification.
+
+Tabular structures involving some or all of those features are represented in accordance with this document architecture, and those structures are embedded into logical and layout structures of documents represented in accordance with the document architecture of ITU-T Recommendation T.412 | ISO/IEC 8613-2.
+
+Further, the reference model of the document layout process described in this Specification may generate specific layout structures including tabular structures, evaluating those tabular structures embedded into logical structures and generic layout structures.
+
+Thereafter, the reference model of the document imaging process described in this Specification may present tabular structures involved in such specific layout structures as human perceptible tabular layout on rendition media.
+
+This Specification introduces new attributes to cover those features of tabular structures and tabular layout. At the end of each subclause of this clause, those attributes which are related to the feature described in the sub-clause will be listed as **Related attributes**.
+
+Only for illustration in this clause, the following terminology is introduced:
+
+- *table cell*: a rectangular area within a table edged with table lines;
+- *table entry*: a piece of content laid out within a table cell;
+- *table line*: a visible or invisible line delimiting table entries distributed within a table.
+
+The framework of tabular layout consists of a set of table lines which intersect one another so that the framework shall provide two-dimensional allocation of table cells. Each table entry is laid out within a respective table cell.
+
+## 7.1 Content types and inner structures of table entries
+
+A table shall allow table entries to contain various types of content, such as character texts, pictures and so forth.
+
+Further, a table shall allow table entries to have an inner structure, such as a picture with a caption, more than one paragraph and so forth.
+
+**Related attributes:** “grid description”
+
+## 7.2 Dimensions of tables, rows and columns
+
+The dimensions of a table (height, width), of a row (height), and a column (width) may be specified in one of the following ways:
+
+- the dimension concerned shall be a specified absolute value;
+- it shall expand to an area available for its presentation;
+- it shall be a minimum value necessary for its presentation.
+
+Additionally, the height of a row and the width of a column may be specified as:
+
+- the dimension concerned shall be in proportion to the dimensions of other particular rows or columns.
+
+**Related attributes:** “grid dimensions”, “grid interval dimensions”
+
+## 7.3 Placement of tables
+
+A table may be aligned within the area available for placement in the horizontal and vertical directions:
+
+- the table may be aligned on the left or right, or centred;
+- the table may be aligned at the top or bottom, or centred;
+- every combination of alignment in the horizontal and vertical directions shall be allowed.
+
+**Related attributes:** “grid position”
+
+## 7.4 Spanning cells
+
+A table cell spanning more than one row and more than one column shall be allowed to appear at an arbitrary position within a table.
+
+**Related attributes:** “grid description”
+
+## 7.5 Placement of table entries
+
+### 7.5.1 Gutter space around table lines
+
+A gutter space, from which any table entries are to be excluded, may be reserved around a table line.
+
+**Related attributes:** “gutters”
+
+### 7.5.2 Offset of table entries
+
+Offsets of a table entry from the edges of the table cell within which the table entry is laid out shall be specifiable.
+
+**Related attributes:** “grid position”
+
+### 7.5.3 Alignment of a table entry within a table cell
+
+A table entry may be aligned within a table cell arbitrarily in the horizontal and vertical directions:
+
+- the table entry may be aligned on the left or the right, or centred;
+- the table entry may be aligned at the top or bottom, or centred;
+- every combination of alignment in the horizontal and vertical directions shall be allowed.
+
+**Related attributes:** “position”
+
+### 7.5.4 Reference line alignment
+
+A table entry may provide an alignment point. If such table entries are in a row or a column, they may be aligned so that all of the alignment points shall be lined up on a reference line in the direction of the row or column. Two of the most typical examples of reference line alignment are *alignment around decimal points* and *base line alignment*.
+
+**Related attributes:** “reference line alignment – major / minor”, “frame alignment point”, “block alignment point”, “alignment point”
+
+In addition, a table entry involved in reference line alignment may be indented from the reference line concerned.
+
+**Related attributes:** “indent – major / minor”
+
+After this alignment, the entire set of table entries may be aligned on the left or the right, or centred, within the row or column.
+
+**Related attributes:** “position”
+
+## 7.6 Split of tables
+
+When a table overflows such an area available for its presentation as a page, a page column, frame and so forth, the table may or may not split into two or more fragments each of which is presented within an individual available area. Further, each fragment of the table may be presented in a different way: for example, the first fragment includes the area for a table title; the last fragment includes the area for notes; the intermediate fragments include neither.
+
+**Related attributes:** “grid frame classes”
+
+### 7.6.1 Direction of table split
+
+When splitting of a table is allowed, it may occur in the horizontal and / or vertical direction:
+
+- a table may be split only at table lines delimiting rows;
+- a table may be split only at table lines delimiting columns;
+- a table may be split both at table lines delimiting rows and at table lines delimiting columns; in this case, the order of presentation of fragments shall be taken into consideration.
+
+**Related attributes:** “indivisibility”, “presentation precedence”
+
+Furthermore, in all the cases, the table shall not be split at an unsuitable table line, such as a horizontal table line immediately following box headings.
+
+**Related attributes:** “same layout object”, “selective same layout objects”
+
+### 7.6.2 Repetition of headings
+
+When a table is split, such headings within the table as box headings may be repeated within each fragment of the table.
+
+**Related attributes:** “obligatory same layout objects”
+
+## 7.7 Rendition of table lines
+
+The method of rendition of a table line shall be determined for each individual line segment composing the table line. For example, if a segment of the table line is within a spanning cell or the stub of the table (the leftmost column for row headings), the line segment shall be rendered invisible.
+
+**Related attributes:** “grid lines”
+
+## 7.8 Supplementary lines
+
+In addition to table lines, some supplementary lines may be presented:
+
+- a diagonal line may divide the top left table cell into two triangles;
+- a reference line may be rendered visible.
+
+**Related attributes:** “supplementary lines, supplementary line directive”
+
+# 8 Grid logical components
+
+A *grid logical component* is a variant of a composite logical component. Any of the attributes applicable to composite logical components are also applicable to a grid logical component. In this Specification, particularly in the **Constituents** clauses of the attribute definitions, grid logical components and ordinary composite logical components may be collectively referred to as “composite logical components”.
+
+A grid logical component is identified by the value ‘grid logical’ specified for the attribute “object type”, and a grid logical object is characterized by the association with a *logical grid*.
+
+Unless the attribute “grid frame classes” is applied to a grid logical object, the layout process shall deal with the grid logical object as an ordinary composite logical object. Hence, those layout directive attributes proper to the grid logical component, namely “grid description”, “presentation precedence” and “supplementary lines” shall never affect the layout of documents.
+
+## 8.1 Logical grids
+
+### 8.1.1 Logical grid lines and logical grid locations
+
+The underlying area of a logical grid is a rectangle within an imaginary plane. This underlying rectangle is dissected by two sets of parallel lines. Each set of parallel lines runs parallel to one of two adjacent edges of the underlying rectangle. The lines and divisions so created comprise the logical grid (see Figure 1).
+
+Such a line is called a *logical grid line*, and a division is called a *logical grid location*.
+
+A logical grid line / location may be simply referred to as a *grid line / location* when it is obvious from the context that it is a logical grid line / location rather than a *layout grid line / location*, and vice versa (see 9.1.1 and 9.1.7).
+
+### 8.1.2 Major and minor paths
+
+The terms *major path* and *minor path* denote the two orthogonal directions within a logical grid which are parallel to the edges of the underlying rectangle.
+
+Conventionally, a logical grid is considered to be upright: the major path is the vertically downward direction, and the minor path is the horizontally rightward direction (see Figure 1).
+
+### 8.1.3 Major and minor logical grid lines
+
+Every logical grid line runs parallel to either the major or minor path.
+
+A logical grid line running parallel to the minor / major path of a logical grid is called a *major / minor logical grid line*. Within a logical grid, every major / minor logical grid line is identified by an ordinal number (see Figure 1):
+
+- a) the number 0 is assigned to the major / minor logical grid line which is the first in the direction of the major / minor path;
+- b) the major / minor logical grid line with number  $n + 1$  is adjacent to the major / minor logical grid line with number  $n$  in the direction of the major / minor path.
+
+![Diagram of a logical grid showing major and minor paths, grid lines, and a grid location.](7b8b192e2853ef28d28eff0241ebe86b_img.jpg)
+
+The diagram illustrates a logical grid as a 6x6 grid of squares. The grid is defined by 7 vertical and 7 horizontal lines. The horizontal lines are labeled on the right as '0th major logical grid line' (top), '1st major logical grid line', and '2nd major logical grid line'. The vertical lines are labeled on the left as '0th minor logical grid line' (left), '1st minor logical grid line', and '2nd minor logical grid line'. An arrow labeled 'Minor path' points to the right above the grid. An arrow labeled 'Major path' points downwards to the left of the grid. One square in the grid, located at the intersection of the 5th vertical line and the 5th horizontal line (counting from 0), is shaded gray and labeled 'Logical grid location'. The text 'TISO5040-95/d01' is printed at the bottom right of the grid.
+
+Diagram of a logical grid showing major and minor paths, grid lines, and a grid location.
+
+Figure 1 – Logical grid
+
+### 8.1.4 Major and minor sizes of a logical grid
+
+The *major / minor size* of a logical grid is defined as the largest ordinal number assigned to a major / minor grid line within the logical grid.
+
+The major / minor size of a logical grid is specified by the parameter “major / minor size” of the attribute “grid description” applied to the grid logical object with which the logical grid is associated.
+
+Since a logical grid is conventionally considered to be upright, its major / minor size corresponds to the number of rows / columns within it.
+
+### 8.1.5 Logical coordinates
+
+Each intersection point of the logical grid is represented by a *logical coordinate pair*: *major logical coordinate* and *minor logical coordinate*.
+
+The major / minor logical coordinate of the point is the ordinal number assigned to the major / minor logical grid line on which the point is located.
+
+Additionally, the special value ‘last’ may be specified for the major / minor logical coordinate. This value specifies that the point is located on the last major / minor logical grid line, to which the largest ordinal number is assigned.
+
+### 8.1.6 Logical grid rectangles
+
+If one or more logical grid locations comprise a rectangle within a logical grid, the rectangle is called a *logical grid rectangle*. Hence, a logical grid rectangle is edged with a pair of major logical grid lines and a pair of minor logical grid lines.
+
+The smallest logical grid rectangle is a single logical location.
+
+A logical grid rectangle may be called simply a *grid rectangle* when it is obvious from the context that it is a logical grid rectangle rather than a *layout grid rectangle*, and vice versa (see 9.1.7).
+
+## 8.2 Association of entry objects with logical grid rectangles
+
+A logical object subordinate to a grid logical object may be associated with a logical grid rectangle within the logical grid associated with the grid logical object (see Figure 2). Such a logical object is called an *entry object* occupying that logical grid rectangle. An entry object is not necessarily an immediate subordinate of the grid logical object.
+
+![Figure 2: Association of entry objects with logical grid rectangles. The diagram shows a hierarchical tree structure on the left and a 3x3 grid on the right. The tree starts with a 'Grid logical object' (open circle) at the top. It has two children: a 'Specific logical structure' (open circle) and another open circle. The 'Specific logical structure' has two children, both 'Entry objects' (filled circles). Each 'Entry object' has a 'Sub-structure below entry object' (open triangle) as a child. The other open circle child of the 'Grid logical object' has one child, an 'Entry object' (filled circle), which in turn has three children, all 'Sub-structures below entry object' (open triangles). On the right, a 3x3 'Logical grid' is shown. Arrows indicate the association: the 'Specific logical structure' points to the top-left cell; the first 'Entry object' points to the top-middle cell; the second 'Entry object' points to the top-right cell; the third 'Entry object' points to the bottom-middle cell. A legend at the bottom left identifies the symbols: a filled circle for 'Entry object' and an open triangle for 'Sub-structure below entry object'. The text 'TISO5050-95/d02' is at the bottom right.](cf4ac1058c52bc3ca37737740afb7f2c_img.jpg)
+
+Figure 2: Association of entry objects with logical grid rectangles. The diagram shows a hierarchical tree structure on the left and a 3x3 grid on the right. The tree starts with a 'Grid logical object' (open circle) at the top. It has two children: a 'Specific logical structure' (open circle) and another open circle. The 'Specific logical structure' has two children, both 'Entry objects' (filled circles). Each 'Entry object' has a 'Sub-structure below entry object' (open triangle) as a child. The other open circle child of the 'Grid logical object' has one child, an 'Entry object' (filled circle), which in turn has three children, all 'Sub-structures below entry object' (open triangles). On the right, a 3x3 'Logical grid' is shown. Arrows indicate the association: the 'Specific logical structure' points to the top-left cell; the first 'Entry object' points to the top-middle cell; the second 'Entry object' points to the top-right cell; the third 'Entry object' points to the bottom-middle cell. A legend at the bottom left identifies the symbols: a filled circle for 'Entry object' and an open triangle for 'Sub-structure below entry object'. The text 'TISO5050-95/d02' is at the bottom right.
+
+Figure 2 – Association of entry objects with logical grid rectangles
+
+These associations between entry objects and logical grid rectangles are specified by the parameter “entry-location association” of the attribute grid description applied to the grid logical object with which the logical grid is associated (see 12.2.2).
+
+In addition, the associations between entry objects and logical grid rectangles affect the order in which the layout process lays out the content of those basic logical objects that are subordinate to the logical grid object. Therefore, if a grid frame is superior to another grid frame, their effects on this processing order of their common subordinate basic logical objects shall be compatible (see 13.5).
+
+# 9 Grid frame components
+
+A *grid frame component* can be any frame except a lowest level frame component. Any of the attributes applicable to frame components except the attribute “permitted categories” are also applicable to a grid frame component. In this Specification, particularly in the **Constituents** clauses of the attribute definitions, grid frame components and ordinary frame components may be collectively referred to as “frame components”.
+
+A grid frame component is identified by the value ‘grid frame’ specified for the attribute “object type”, and a grid frame is characterized by the capability to contain a layout grid within it.
+
+A grid frame contains a layout grid whenever the object description for the grid frame specifies the attribute “grid interval dimensions”. Conversely, without the attribute “grid interval dimensions”, the grid frame does not contain a layout grid.
+
+If a grid frame does not contain a layout grid, the imaging process shall deal with the grid frame as if it were an ordinary frame, and shall not present any layout grid lines within it.
+
+When the layout process reach a grid logical object description specifying the attribute “grid frame classes”, the layout process identifies one or more grid frames within the specific layout structure under construction, in accordance with this attribute. Those identified grid frames are called *grid frames referred to* by the grid logical object (see 9.2).
+
+The layout process generates a layout grid within each referenced grid frame. This layout grid includes the same number of major / minor grid lines (see 9.1.1) as the logical grid associated with the grid logical object does.
+
+## 9.1 Layout grid
+
+### 9.1.1 Layout grid lines
+
+A *layout grid* is composed of a finite number of lines, called *layout grid lines*. Each layout grid line has its own position, length and direction within the grid frame containing the layout grid.
+
+Layout grid lines within a grid frame satisfy the following constraints:
+
+- every layout grid line shall be parallel with one of the edges of the grid frame;
+- no layout grid line shall fall within the border free space of the grid frame;
+- every layout grid line shall have its ends located on the same pair of orthogonal grid lines.
+
+Thus, in ordinary cases, a layout grid is a rectangle divided by a finite number of horizontal and vertical lines, each of which has its ends on opposite edges of the rectangle (see Figure 3).
+
+Two layout grid lines may be located at the same position within the grid frame (see 12.1.4). Further, if the layout grid lines running in one of the two directions are all located at the same position, then the length of the layout grid lines in the orthogonal direction shall be zero. In such degenerate cases, where some layout grid line has no positive length, a layout grid is either a line segment or a single point.
+
+![Diagram of a layout grid within a grid frame.](812e188283162af0b54fb3e30ffee51b_img.jpg)
+
+The diagram illustrates a layout grid within a grid frame. The grid frame is represented by a solid rectangular border. Inside this frame, there is a dashed rectangular border. Within the dashed border, a 4x4 grid of squares is shown, representing the layout grid. Below the main diagram, two small icons are provided: a 4x4 grid of squares labeled 'Layout grid' and a dashed square labeled 'Border of grid frame'. The text 'TISO5060-95/d03' is located at the bottom right of the diagram.
+
+Diagram of a layout grid within a grid frame.
+
+Figure 3 – Layout grid
+
+### 9.1.2 Major and minor paths
+
+The terms *major path* and *minor path* denote two specified directions within a grid frame which are orthogonal to each other. Further, the major / minor path is parallel with one of the edges of the grid frame.
+
+The attribute “major / minor path” specifies the direction of the major / minor path (see 12.1.8 and 12.1.9).
+
+### 9.1.3 Major and minor layout grid lines
+
+A layout grid line running in the direction of the minor / major path is called a *major / minor layout grid line*.
+
+Major / minor layout grid lines within a grid frame are identified by successive ordinal numbers assigned to them (see Figure 4).
+
+![Figure 4 – Layout grid lines. The diagram consists of two parts. The top part shows a 'Grid frame' with a 'Minor path' indicated by a right-pointing arrow at the top. Inside the frame, there are five vertical lines labeled '0th minor layout grid line', '1st minor layout grid line', '2nd minor layout grid line', '3rd minor layout grid line', and '4th minor layout grid line'. A 'Major path' is indicated by a downward-pointing arrow on the left. The bottom part shows another 'Grid frame' with a 'Minor path' indicated by a right-pointing arrow at the top. Inside, there are four horizontal lines labeled '0th major layout grid line', '1st major layout grid line', '2nd major layout grid line', and '3rd major layout grid line'. A 'Major path' is indicated by a downward-pointing arrow on the left. Below the diagrams is a small 2x2 grid icon labeled 'Layout grid' and the text 'TISO5070-95/d04'.](08a978a124d3ed6cf1a3d0cfd89418d0_img.jpg)
+
+Figure 4 – Layout grid lines. The diagram consists of two parts. The top part shows a 'Grid frame' with a 'Minor path' indicated by a right-pointing arrow at the top. Inside the frame, there are five vertical lines labeled '0th minor layout grid line', '1st minor layout grid line', '2nd minor layout grid line', '3rd minor layout grid line', and '4th minor layout grid line'. A 'Major path' is indicated by a downward-pointing arrow on the left. The bottom part shows another 'Grid frame' with a 'Minor path' indicated by a right-pointing arrow at the top. Inside, there are four horizontal lines labeled '0th major layout grid line', '1st major layout grid line', '2nd major layout grid line', and '3rd major layout grid line'. A 'Major path' is indicated by a downward-pointing arrow on the left. Below the diagrams is a small 2x2 grid icon labeled 'Layout grid' and the text 'TISO5070-95/d04'.
+
+Figure 4 – Layout grid lines
+
+This allocation of numbers shall satisfy the following:
+
+- the smallest number assigned to the major / minor layout grid lines is 0;
+- the major / minor layout grid line with number  $n + 1$  is either at the same position as the major / minor layout grid line with number  $n$ , or is adjacent to it in the direction of the major / minor path.
+
+NOTE – When two or more grid lines occupy the same position, the order in which ordinal numbers are allocated to those lines is arbitrary.
+
+### 9.1.4 Grid line segments
+
+A *grid line segment* is a segment of a layout grid line delimited by two consecutively numbered layout grid lines intersecting the layout grid line concerned at right angles.
+
+The  $j$ -th grid line segment of the  $i$ -th major / minor layout grid line is the segment of the  $i$ -th major / minor layout grid line, delimited by the  $(j - 1)$ -th and  $j$ -th minor / major layout grid lines.
+
+Grid line segments are the smallest unit to which a *line segment characteristic* applies (see 11.10). A single line segment characteristic specifies a single set of *imaging factors* (i.e. line width, line type and line colour).
+
+- Each individual grid line segment is imaged with a single line width, a single line type and a single line colour.
+
+- Distinct grid line segments may be imaged with different line widths, different line types or different line colours, even if they are forming part of the common layout grid line.
+
+The attribute “grid lines” applied to the grid frame specifies a set of line segment characteristics, each of which is applicable to each individual grid line segment involved in the relevant layout grid (see 12.1.5).
+
+### 9.1.5 Major and minor sizes of a layout grid
+
+The largest ordinal number assigned to a major / minor grid line within a layout grid is called the *major / minor size* of the layout grid.
+
+In contrast to the case of a logical grid, where the major and minor sizes of the logical grid are explicitly specified by the attribute “grid description” (see 12.2.2), those of a layout grid are only implicitly specified by the attribute “grid interval dimensions” that the object description for the grid frame specifies (see 12.1.4).
+
+The attribute “grid interval dimensions” consists of two parameters “major interval dimensions” and “minor interval dimensions”. The value of each parameter is a *grid interval expression* of the grid sequence construction type (see 11.1) composed of *interval indicators* (see 11.4), namely a sequence of a finite number of interval indicators, when the attribute is specified for an object description. The number of interval indicators involved in the value of the parameter “major / minor interval dimensions” indicates the major / minor size of the layout grid.
+
+### 9.1.6 Major and minor dimensions of a layout grid
+
+If an edge of a layout grid is in the direction of the minor / major path specified for the grid frame including the layout grid, its length in scaled measurement units is called the *major / minor dimension* of the layout grid.
+
+The attribute “grid dimensions” applied to the grid frame specifies the major and minor dimensions of the layout grid within the grid frame (see 12.1.2).
+
+### 9.1.7 Grid intervals, layout grid locations and layout grid rectangles
+
+A *grid interval* is a rectangular area within a layout grid, delimited by two consecutively numbered layout grid lines in the same direction (see Figure 5).
+
+If the grid lines delimiting the grid interval are in the direction of the major / minor path, then the grid interval is called a *major / minor grid interval*. Furthermore, the *i*-th major / minor grid interval is the major / minor grid interval delimited by the (*i* – 1)-th and *i*-th major / minor layout grid lines.
+
+A *layout grid rectangle* is an area within a layout grid edged with two major layout grid lines and two minor layout grid lines. Any grid interval, whether it is major or minor, is a kind of layout grid rectangle.
+
+In particular, a layout grid rectangle is called a *layout grid location* if it is edged with consecutively numbered major layout grid lines and consecutively numbered minor layout grid lines.
+
+In degenerate cases, where the positions of the edging layout grid lines coincide, the grid interval, layout grid rectangle or layout grid location may be a single line segment or a single point in shape.
+
+![Figure 5 – Grid intervals. The diagram consists of two parts. The top part shows a 4x3 grid of cells. The first column is labeled '1st minor grid interval', the second '2nd minor grid interval', the third '3rd minor grid interval', and the fourth '4th minor grid interval'. A horizontal arrow above the grid is labeled 'Minor path' and points to the right. A vertical arrow to the left of the grid is labeled 'Major path' and points downwards. The entire grid is enclosed in a box labeled 'Grid frame'. The bottom part shows a 3x3 grid of cells. The first row is labeled '1st major grid interval', the second row '2nd major grid interval', and the third row '3rd major grid interval'. A horizontal arrow above the grid is labeled 'Minor path' and points to the right. A vertical arrow to the left of the grid is labeled 'Major path' and points downwards. The entire grid is enclosed in a box labeled 'Grid frame'. Below the bottom grid is a small 2x2 grid labeled 'Layout grid'. The text 'TISO5080-95/d05' is located at the bottom right of the diagram.](73b5cce955ba9415a98791db7b0080ad_img.jpg)
+
+Figure 5 – Grid intervals. The diagram consists of two parts. The top part shows a 4x3 grid of cells. The first column is labeled '1st minor grid interval', the second '2nd minor grid interval', the third '3rd minor grid interval', and the fourth '4th minor grid interval'. A horizontal arrow above the grid is labeled 'Minor path' and points to the right. A vertical arrow to the left of the grid is labeled 'Major path' and points downwards. The entire grid is enclosed in a box labeled 'Grid frame'. The bottom part shows a 3x3 grid of cells. The first row is labeled '1st major grid interval', the second row '2nd major grid interval', and the third row '3rd major grid interval'. A horizontal arrow above the grid is labeled 'Minor path' and points to the right. A vertical arrow to the left of the grid is labeled 'Major path' and points downwards. The entire grid is enclosed in a box labeled 'Grid frame'. Below the bottom grid is a small 2x2 grid labeled 'Layout grid'. The text 'TISO5080-95/d05' is located at the bottom right of the diagram.
+
+Figure 5 – Grid intervals
+
+### 9.1.8 Dimensions of grid intervals
+
+The term *grid interval dimension* denotes the distance between two consecutively numbered layout grid lines in the same direction.
+
+If the layout grid lines are in the direction of the minor / major path, the grid interval dimension is called a *major / minor grid interval dimension*. In particular, the distance between the  $(i - 1)$ -th and  $i$ -th major / minor layout grid lines is called the  $i$ -th major / minor grid interval dimension (see Figure 6).
+
+The attribute “grid interval dimensions” applied to a grid frame specifies the dimensions of the grid intervals involved in the grid frame. Evaluation of the values of this attribute produces a set of interval indicators, each of which is to be applied to each individual grid interval.
+
+If this attribute is specified in the class description for the grid frame, the interval indicator applied to each grid interval specifies a rule to determine the dimension of the grid interval. The layout process evaluates this interval indicator, and then determines the dimension of the grid interval.
+
+In particular, the dimension of a grid interval may be determined to be 0, only if no content is laid out within this grid interval, and the interval indicator to be applied specifies one of the following (see 11.4):
+
+- the parameter “fixed dimension” associated with the value 0;
+- the parameter “rule B” with the minimum dimension 0;
+- the parameter “proportional” with the default dimension 0.
+
+If and only if the grid interval dimension is 0, then the two layout grid lines delimiting the grid interval are located at the same position.
+
+If the attribute “grid interval dimensions” is specified in the object description for the grid frame, the interval indicator applied to each grid interval specifies the parameter “fixed dimension” associated with the dimension of the grid interval in scaled measurement units (see 12.1.4).
+
+![Figure 6: Grid interval dimensions. The diagram shows two grid frames illustrating major and minor grid interval dimensions. The top frame shows a 4x3 grid with vertical dimensions labeled '1st minor grid interval dimension' through '4th minor grid interval dimension'. The bottom frame shows a 3x3 grid with vertical dimensions labeled '1st major grid interval dimension' through '3rd major grid interval dimension'. Arrows indicate the 'Major path' (downward) and 'Minor path' (rightward). A small 2x2 'Layout grid' icon is shown at the bottom left, and the text 'TISO5090-95/d06' is at the bottom right.](26d664119ad25250780f554633444e54_img.jpg)
+
+The diagram illustrates grid interval dimensions in two parts. The top part shows a grid frame with a 4x3 grid of cells. The vertical dimensions of the columns are labeled '1st minor grid interval dimension', '2nd minor grid interval dimension', '3rd minor grid interval dimension', and '4th minor grid interval dimension'. The horizontal dimensions of the rows are labeled '1st major grid interval dimension', '2nd major grid interval dimension', and '3rd major grid interval dimension'. Arrows indicate the 'Major path' (downward) and 'Minor path' (rightward). The bottom part shows a similar grid frame with a 3x3 grid of cells. The vertical dimensions of the columns are labeled '1st major grid interval dimension', '2nd major grid interval dimension', and '3rd major grid interval dimension'. The horizontal dimensions of the rows are labeled '1st minor grid interval dimension', '2nd minor grid interval dimension', and '3rd minor grid interval dimension'. Arrows indicate the 'Major path' (downward) and 'Minor path' (rightward). A small 2x2 'Layout grid' icon is shown at the bottom left, and the text 'TISO5090-95/d06' is at the bottom right.
+
+Figure 6: Grid interval dimensions. The diagram shows two grid frames illustrating major and minor grid interval dimensions. The top frame shows a 4x3 grid with vertical dimensions labeled '1st minor grid interval dimension' through '4th minor grid interval dimension'. The bottom frame shows a 3x3 grid with vertical dimensions labeled '1st major grid interval dimension' through '3rd major grid interval dimension'. Arrows indicate the 'Major path' (downward) and 'Minor path' (rightward). A small 2x2 'Layout grid' icon is shown at the bottom left, and the text 'TISO5090-95/d06' is at the bottom right.
+
+Figure 6 – Grid interval dimensions
+
+### 9.1.9 Naming of edges of a layout grid rectangle
+
+The *leading*, *trailing*, *left-hand* and *right-hand* edges of a layout grid rectangle are defined relative to the layout path of the grid frame (see Figure 7):
+
+- The leading and trailing edges are defined as the two opposite edges of the rectangle that are orthogonal to the direction of the layout path, such that the direction from the trailing edge to the leading edge is in the same direction as the layout path.
+- The left-hand and right-hand edges are defined as the two opposite edges of the rectangle that are parallel to the direction of the layout path, such that the direction from the right-hand edge to the left-hand edge is at an angle of 90° anti-clockwise relative to the direction of the layout path.
+
+![Diagram illustrating the edges of a layout grid rectangle. A central rectangle is defined by a solid black border. It is surrounded by a grid of dashed lines. Labels indicate the 'Trailing edge' at the top, 'Leading edge' at the bottom, 'Right-hand edge' on the left, and 'Left-hand edge' on the right. A vertical arrow labeled 'Layout path' points downwards from the top edge. A legend at the bottom shows a dashed line for 'Layout grid lines' and a solid black rectangle for 'Layout grid rectangle'. The text 'TISO5100-95/d07' is located in the bottom right corner of the diagram area.](0c08e48c08f96934cd6bc6911f3069dc_img.jpg)
+
+Diagram illustrating the edges of a layout grid rectangle. A central rectangle is defined by a solid black border. It is surrounded by a grid of dashed lines. Labels indicate the 'Trailing edge' at the top, 'Leading edge' at the bottom, 'Right-hand edge' on the left, and 'Left-hand edge' on the right. A vertical arrow labeled 'Layout path' points downwards from the top edge. A legend at the bottom shows a dashed line for 'Layout grid lines' and a solid black rectangle for 'Layout grid rectangle'. The text 'TISO5100-95/d07' is located in the bottom right corner of the diagram area.
+
+Figure 7 – Edges of grid rectangles
+
+### 9.1.10 Grid gutter spaces
+
+A *grid gutter space* around a layout grid line is a rectangular area within a layout grid, delimited by two lines running parallel to the layout grid line concerned, such that the layout grid line runs equidistant from these two edging lines. The *width of the grid gutter space* is defined as the distance between these two edging lines.
+
+If a variably positioned frame is constrained to be laid out inside some layout grid rectangle within its immediately superior grid frame (see 9.3), the frame shall be excluded from the grid gutter spaces reserved around the four edges of the layout grid rectangle.
+
+The attribute “grid gutters” applied to the grid frame specifies the widths of the grid gutter spaces around the layout grid lines within the grid frame (see 12.1.3).
+
+### 9.1.11 Position of a layout grid
+
+If the grid frame contains a layout grid, the layout grid is positioned within this grid frame so that it shall never fall within the border free space of the grid frame. The attribute “border” applied to the grid frame specifies the border free space to be taken into account in positioning the layout grid (see 9.4.1.3 of ITU-T Rec. T.412 | ISO/IEC 8613-2).
+
+The position of a layout grid within a grid frame is represented in one of the following ways:
+
+- The distances in the direction of the major and minor paths, from the *grid reference point* of the grid frame, to the *grid origin* of the layout grid (see Figure 8) are specified; the grid reference point is one of the corners of the grid frame, while the grid origin is one of the corners of the layout grid; both the grid reference point and the grid origin are defined relative to the major and minor paths of the grid frame (see Table 2).
+- The alignment of the layout grid in the directions of the major and minor paths is specified.
+
+The attribute “grid position” applied to the grid frame specifies the position of the layout grid within the grid frame, in one of the above ways (see 12.1.6).
+
+![Diagram illustrating the grid origin and grid reference point. A grid frame is shown with a grid origin at the top-left corner of the grid. A grid reference point is shown at the top-left corner of the grid frame. A dashed line connects the grid reference point to the grid origin. The grid frame is labeled 'Grid frame'. The grid origin is labeled 'Grid origin'. The grid reference point is labeled 'Grid reference point'. The grid position is labeled 'Grid position'. The minor path is labeled 'Minor path' with an arrow pointing right. The major path is labeled 'Major path' with an arrow pointing down. The diagram is labeled 'TISO5110-95/d08' at the bottom right.](043e64d41a3368d138ace3816fd26469_img.jpg)
+
+Diagram illustrating the grid origin and grid reference point. A grid frame is shown with a grid origin at the top-left corner of the grid. A grid reference point is shown at the top-left corner of the grid frame. A dashed line connects the grid reference point to the grid origin. The grid frame is labeled 'Grid frame'. The grid origin is labeled 'Grid origin'. The grid reference point is labeled 'Grid reference point'. The grid position is labeled 'Grid position'. The minor path is labeled 'Minor path' with an arrow pointing right. The major path is labeled 'Major path' with an arrow pointing down. The diagram is labeled 'TISO5110-95/d08' at the bottom right.
+
+Figure 8 – Grid origin and grid reference point
+
+### 9.1.12 Minimal layout of a layout grid
+
+Determination of the grid interval dimensions involved in a layout grid provides a *minimal layout* of the layout grid, if and only if, for an arbitrary subset of the grid intervals of the layout grid, their determined dimensions cannot be reduced without increasing the determined dimensions for other grid intervals or violating the following constraints:
+
+- constraints on the major and minor dimensions of the layout grid, imposed by the attribute “grid dimensions” (see 12.1.2);
+- constraints on the major and minor interval dimensions of the layout grid, imposed by the attribute “grid interval dimensions” (see 12.1.4).
+
+In general, there may be more than one instance of minimal layout for a single layout grid. The layout process shall generate one of those instances of the minimal layout for the layout grid.
+
+## 9.2 Association of grid frames with grid logical objects
+
+The attribute “grid frame classes” specifies a construction expression whose evaluation may produce a sequence of grid frame classes. If this attribute is applied to a grid logical object, a sequence of one or more grid frames shall be identified in the specific layout structure concerned (see 12.2.3).
+
+A sequence of grid frames to be identified shall satisfy the following conditions:
+
+- the order of grid frames given by the sequence coincides with their sequential layout order;
+- the sequence of frame classes obtained by replacing every grid frame in the sequence with its frame class is one of the values that can be derived from evaluation of the construction expression specified for the attribute.
+
+The content associated with the grid logical object shall be laid out entirely within the grid frames of this set. No other part of the document shall be laid out within any grid frame in this set (see 12.2.3).
+
+If a grid frame is identified in accordance with the attribute “grid frame classes” applied to a grid logical object, the grid frame is called a *grid frame referred to* by the grid logical object.
+
+## 9.3 Binding of entry frames to layout grid rectangles
+
+Every grid frame referred to by a grid logical object contains a layout grid.
+
+This layout grid includes the same number of major / minor grid lines as the logical grid associated with the grid logical object does. By means of ordinal numbers assigned to grid lines within the layout grid and the logical grid, the following correspondences between grid lines and between grid rectangles are defined.
+
+### 9.3.1 Correspondence between layout grid lines and logical grid lines
+
+The correspondence between the major / minor layout grid lines within the layout grid and the major / minor logical grid lines within the logical grid is such that:
+
+- the  $i$ -th major / minor layout grid line corresponds to the  $i$ -th major / minor logical grid line, and vice versa.
+
+### 9.3.2 Correspondence between layout grid rectangles and logical grid rectangles
+
+The correspondence between the layout grid rectangles within the layout grid and the logical grid rectangles within the logical grid is such that:
+
+- a layout grid rectangle corresponds to the logical grid rectangle whose four edging logical grid lines respectively correspond to the four layout grid lines edging the layout grid rectangle, and vice versa.
+
+If a layout grid rectangle corresponds to a logical grid rectangle, the former rectangle is called the *layout counterpart* of the latter rectangle.
+
+### 9.3.3 Layout of content associated with entry objects
+
+The content associated with an entry object, which occupies a logical grid rectangle within the logical grid associated with its superior grid logical object, shall be laid out within frames immediately subordinate to those grid frames referred to by this grid logical object. Moreover, each of those frames shall be located inside the layout counterpart of the logical grid rectangle which the entry object occupies, no matter whether it is variably positioned, or has its position strictly fixed, within its immediately superior grid frames.
+
+A frame to be variably positioned within the immediately superior grid frame is called an *entry frame*. If the content of an entry object is laid out within an entry frame, and therefore the entry frame is constrained to be laid out inside the layout counterpart of the logical grid rectangle which the entry frame occupies, the entry frame is said to be *bound to* that layout grid rectangle.
+
+# 10 Duplication of content
+
+If the attribute “obligatory same layout objects” is applied to a logical object, zero or more target objects shall be identified within the specific logical structure concerned (see 12.2.4). Target objects may be basic or composite. Further, in accordance with this attribute, the layout process may duplicate the content associated with the target objects, and thereafter may lay out the generated reproduction of the content.
+
+## 10.1 Reproductions of content
+
+Whenever the duplication of the content of a target object occurs, a reproduction of the entire content associated with this target object, which is complete except for the identification attributes, shall be generated.
+
+### 10.1.1 Reproductions of the content of a basic logical object
+
+A reproduction of the content associated with a single basic logical object is such that:
+
+- the reproduction shall be a single content portion;
+- this generated content portion shall be a reproduction of the unique content portion, called the *source content portion* or the *source* in short, which was originally associated with the basic logical object before the layout process; this reproduction is complete except that it includes neither of the content portion attributes “content identifier – logical” and “content identifier – layout”;
+- this reproduction shall include the other content portion attributes “type of coding”, “content information”, “alternative representation”, as well as the coding attributes proper to the content architecture;
+- the same value is assigned to each of these attributes as the value assigned to its counterpart attribute in the source content portion.
+
+### 10.1.2 Reproductions of the content of a target object
+
+When the target object is a basic logical object, one content portion shall be generated at each occurrence of the duplication of the content of the target object. This generated content portion shall be coincident with the reproduction of the content associated with the target object as defined in 10.1.1.
+
+When the target object is a composite logical object, one content portion shall be generated for each basic logical object subordinate to the target object, at each occurrence of the duplication of the content of the target object. This content portion shall be a reproduction of the content associated with the basic logical object concerned. Hence, when the target object is superior to more than one basic logical object, the same number of content portions shall be generated. This set of content portions is collectively called a *reproduction of the content associated with the target object*.
+
+### 10.1.3 Reproduction bundles
+
+The duplication of content occurs only in accordance with the attribute “obligatory same layout objects” applied to some logical objects (see 12.2.4).
+
+If the attribute “obligatory same layout objects” is applied to a logical object, a set of zero or more target objects shall be identified. If the duplication of content occurs in accordance with this instance of the attribute, one reproduction shall be generated for the content associated with each of those target objects, at each occurrence of the duplication.
+
+The set of those reproductions, which are generated at a single occurrence of the duplication invoked by a single instance of the attribute “obligatory same layout objects”, is called a *reproduction bundle* generated in accordance with this instance of the attribute.
+
+A single reproduction bundle satisfies that:
+
+- for each basic logical object subordinate to each target object, the reproduction bundle contains one content portion that is a reproduction of the content associated with this basic logical object;
+- the reproduction bundle is composed of only these content portions.
+
+The duplication of content may occur whenever it is necessary. It may occur irrespective of the processing order of basic logical objects (see 12.2.5 and 13.5): the layout process may generate a reproduction of the content associated with a basic logical object, even if it has laid out the content associated with basic logical objects that follow it in the processing order.
+
+NOTE – The processing order of basic logical objects is the order in which the layout process lays out basic logical objects. This order is the same as the sequential logical order, unless the attribute “presentation precedence” exists within the logical structure concerned. In that case, the attribute may affect this order (see 12.2.5 and 13.5).
+
+The duplication of content may occur as many times as is necessary, even if it is in accordance with a single instance of the attribute “obligatory same layout object”.
+
+## 10.2 Layout of content within reproductions
+
+### 10.2.1 Order of layout
+
+Whenever it becomes necessary for the layout process to duplicate content, the layout process suspends the layout of the relevant object until it completes the layout of the reproduction bundle generated at this occurrence of the duplication. The following steps are carried out:
+
+- the layout process generates a bundle of reproductions, each of which is for the content associated with a single target object;
+- the layout process lays out those content portions within the reproduction bundle one by one;
+- the order in which the layout process lays out these content portions is the same as the processing order of the basic logical objects with which their source content portions are associated;
+- the layout process starts again the layout of the relevant object.
+
+### 10.2.2 Splits of content portions
+
+The content portion in a reproduction of the content of a basic logical object may split into more than one content portions during the layout process, if the content portion are required to be laid out within more than one block (see also 6.5.2.5 of ITU-T Rec. T.412 | ISO/IEC 8613-2).
+
+### 10.2.3 Effects of layout directive attributes on layout
+
+A reproduction may be laid out taking account of the layout directive attributes that have affected the layout of the source of the reproduction. This subclause provides descriptions of the way in which the layout directive attributes defined in ITU-T Rec. T.412 | ISO/IEC 8613-2 affect the layout of the content of reproductions. For the layout directive attributes introduced in this Specification, their effects on the layout of reproductions is described in clause 12.
+
+The layout directive attributes defined in ITU-T Rec. T.412 | ISO/IEC 8613-2 are classified into two types:
+
+- a) A layout directive attribute of the first type never refers to content other than that associated with the logical object to which it applies, and the effect of the attribute on the layout is confined to this content.  
+The attributes that belong to this type are the attributes “block alignment”, “fill order”, “offset”, “separation”, “layout category”, “logical stream category”, “layout stream sub-category”, “indivisibility”, “layout object class”, and “new layout object”.
+- b) A layout directive attribute of the second type refers to content other than that associated with the logical object to which it applies. Such an attribute specifies that the content associated with that logical object shall be laid out related to the layout of the referenced content.  
+The attributes of this type are the attributes “concatenation”, “floatability range”, “same layout object”, and “synchronization”.
+
+Principally, a layout directive attribute affects the layout of the content of a reproduction bundle as follows.
+
+- a) When the layout directive attribute is of the first type, within the reproduction bundle, the content whose source content portions are associated with the logical object to which the attribute applies shall be laid out in accordance with this attribute. Moreover, the attribute shall independently affect the layout of each individual reproduction bundle.
+- b) When the layout directive attribute is of the second type, the attribute affects the layout of the reproduction bundle if and only if the *affected content*, whose layout is to be affected by the attribute, and the *referenced content*, to which the layout of the affected content is to be related, are both included in the same reproduction. Otherwise, the attribute shall not affect the layout of the reproduction.  
+If the reproduction bundle includes both the affected content and the referenced content at the same time, the affected content shall be laid out related to the referenced content in accordance with the attribute. Moreover, in this case also, the attributes shall independently affect the layout of each individual reproduction of the content.
+
+The following 10.2.3.1 to 10.2.3.10 provides descriptions of the effect of each attribute on the layout of the content of a reproduction of the content of a basic logical object, or a reproduction bundles.
+
+#### 10.2.3.1 “block alignment”, “fill order”, “offset”, “separation”
+
+If any one of the attributes “block alignment”, “fill order”, “offset”, and “separation” applies to a basic logical object, and the reproduction is for the content associated with this basic logical object, then blocks that contain the content of this reproduction shall be laid out within their immediately superior frames as specified by the attribute (see also 9.7.2, 9.7.4, 9.7.12 and 9.7.14 of ITU-T Rec. T.412 | ISO/IEC 8613-2).
+
+#### 10.2.3.2 “layout category”
+
+If the attribute “layout category” applies to a basic logical object, and the reproduction is for the content associated with this basic logical object, then the content of this reproduction shall be constrained to be placed within lowest level frames such that their “permitted categories” include the layout category specified by the attribute (see 9.7.7 and 9.4.2.6 of ITU-T Rec. T.412 | ISO/IEC 8613-2).
+
+#### 10.2.3.3 “logical stream category”, “logical stream sub-category”
+
+If the attributes “logical stream category” and “logical stream sub-category” define a stream category that applies to a basic logical object, and the reproduction is for the content associated with this basic logical object, then the content of this reproduction is constrained to be placed within layout objects to which a stream category applies that is the same as that which applies to the basic logical object (see also 9.7.1.2, 9.7.9 and 9.7.10 of ITU-T Rec. T.412 | ISO/IEC 8613-2).
+
+#### 10.2.3.4 “indivisibility”
+
+If the attribute “indivisibility” applies to a logical object, then, within the reproduction bundle, the affected content is such that its source content portions are associated with this logical object.
+
+The attribute specifies that the affected content shall be laid out within a single layout object that the attribute specifies. However, the attribute never constrains this layout object to contain any other particular content,
+
+- even if it is associated with the logical object concerned;
+- even if it belongs to another reproduction bundle whose source content portion is associated with the logical object concerned.
+
+(See also 9.7.6 of ITU-T Rec. T.412 | ISO/IEC 8613-2.)
+
+#### **10.2.3.5 “layout object class”**
+
+If the attribute “layout object class” applies to a logical object, then, within the reproduction bundle, the affected content is such that its source content portions are associated with this logical object.
+
+The attribute specifies that the affected content shall be laid out within a single layout object that the attribute specifies. Furthermore, no other content shall be laid out within this layout object,
+
+- even if it is associated with the logical object concerned; or
+- even if it belongs to another reproduction whose source content portions were associated with the logical object concerned.
+
+(See also 9.7.8 of ITU-T Rec. T.412 | ISO/IEC 8613-2.)
+
+#### **10.2.3.6 “new layout object”**
+
+If the attribute “new layout object” applies to a logical object, and the reproduction is for the content associated with the first basic logical object subordinate to this logical object, then the content of this reproduction shall be laid out starting within the next layout object specified by the attribute which does not contain any prior content (see also 9.7.11 of ITU-T Rec. T.412 | ISO/IEC 8613-2).
+
+NOTE – In 10.2.3.8 and 10.2.3.9, the first “basic logical object” and the “last basic logical objects” are the first and last basic logical objects subordinate to the logical objects in the processing order of basic logical objects (see 12.2.5 and 13.5).
+
+#### **10.2.3.7 “concatenation”**
+
+If the attribute “concatenation” applies to a basic logical object with the value ‘concatenated’, then, within the reproduction bundle:
+
+- a) the affected content is such that its source content portion is associated with the basic logical object to which the attribute applies;
+- b) the referenced content is such that their source content portion is associated with the nearest preceding basic logical object which has the same content architecture class, layout category, stream category, and fill order.
+
+The attribute specifies that this affected content and this referenced content shall be concatenated (see also 9.7.3 of ITU-T Rec. T.412 | ISO/IEC 8613-2).
+
+NOTE – In the above, “a preceding basic logical object” is one preceding the basic logical object in the processing order of basic logical objects (see 12.2.5 and 13.5). If the attribute “presentation precedence” exists within the specific logical structure concerned, this order may be different from the sequential logical order.
+
+#### **10.2.3.8 “floatability range”**
+
+If the attribute “floatability range” applies to a logical object, then, within the reproduction bundle:
+
+- a) the affected content is such that its source content portions are associated with the logical object to which the attribute applies;
+- b) one referenced content is such that their source content portions are associated with the logical objects that the sub-parameters “logical object” identifies of the parameter “forward limit”;
+- c) the other referenced content is such that their source content portions are associated with the logical objects that the sub-parameters “logical object” identifies of the parameter “backward limit”;
+
+The attribute specifies that this affected content shall be laid out between the former referenced content and the latter referenced content in the layout sequential order (see also 9.7.5 of ITU-T Rec. T.412 | ISO/IEC 8613-2).
+
+#### **10.2.3.9 “same layout object”**
+
+If the attribute “same layout object” applies to a logical object, then within the reproduction bundle,
+
+- a) the affected content is such that its source content portion is associated with the first basic logical object subordinate to the logical object to which the attribute applies;
+- b) the referenced content is such that its source content portion is associated with the last basic logical object subordinate to the logical object that the parameter “logical object” of the attribute specifies.
+
+The attribute specifies that the start of this affected content and the end of this referenced content shall be laid out within a single layout object which is of the layout object class or object type specified by the parameter “layout object” of the attribute (see also 9.7.13 of ITU-T Rec. T.412 | ISO/IEC 8613-2).
+
+#### 10.2.3.10 “synchronization”
+
+If the attribute “synchronization” applies to a logical object, then, within the reproduction bundle,
+
+- a) the affected content is such that its source content portion is associated with the first basic logical object subordinate to the logical object to which the attribute applies;
+- b) the referenced content is such that its source content portion is associated with the first basic logical object that the attribute specifies.
+
+The attribute specifies that this affected content and this referenced content shall be laid out aligned along a line orthogonal to the direction of the layout path (see also 9.7.15 of ITU-T Rec. T.412 | ISO/IEC 8613-2).
+
+## 10.3 Content identifiers for reproductions
+
+When the content portion of a reproduction of the content associated with a basic logical object is laid out within a block, the attribute “content identifier – layout” shall be assigned to the content portion. In contrast, the attribute “content identifier – logical” shall never be assigned throughout the layout process.
+
+When the content portion is split into more than one content portion, and therefore it is laid out within more than one block, the attribute “content identifier – layout” shall be assigned to each split content portion. In this case also, the “content identifier – logical” shall never be assigned to any split content portion.
+
+Hence, any content portion which stems from a content portion within a reproduction never includes the attribute “content identifier – logical”. In other words, such a content portion shall never be associated with any basic logical object (see 5.1).
+
+This Specification abuses the term *reproduction* or the term *reproduction bundle*: even if content portions within a reproduction (bundle) are split into smaller content portions, the set consisting of these content portions may be also referred to as a reproduction (bundle).
+
+# 11 Expressions
+
+## 11.1 Grid construction expressions
+
+Evaluation of a grid construction expression may produce either an empty sequence or a sequence of one or more *atoms*. Different types of grid construction expression deliver different types of atom.
+
+A grid construction expression shall satisfy the following *deterministic condition*:
+
+- if two sequences of atoms are derived from evaluation of a single grid construction expression, and they are of the same length, these sequences are coincident with each other.
+
+NOTE – The length of a sequence of atoms is defined as the number of atoms composing the sequence. If the sequence is empty, its length is defined as 0.
+
+There are four types of grid construction expressions, each of which delivers a different type of atom (see Table 1):
+
+- grid interval expressions;
+- grid gutter expressions;
+- grid line expressions;
+- line characteristic expressions.
+
+A grid construction expression is either a grid construction term or a grid construction type. A grid construction type is one of the following:
+
+- a grid sequence construction, which consists of one or more grid construction terms, which are to be evaluated in the order specified;
+- a grid aggregate construction, which consists of one or more grid construction terms, which are to be evaluated in an arbitrary order;
+- a grid choice construction, which consists of one or more grid construction terms, one of which is to be evaluated.
+
+A grid construction term is one of the following:
+
+- a grid required construction factor;
+- a grid optional construction factor;
+
+- a grid repetitive construction factor;
+- a grid optional repetitive construction factor.
+
+Each grid construction factor is either an atom or a grid construction type. In the former case, the value of the grid construction factor is the atom. In the latter case, the value of the grid construction factor is derived by evaluation of the grid construction type. Evaluation of the grid construction type may produce either an empty sequence or a sequence of one or more atoms:
+
+- A grid required construction factor is to be evaluated once when the containing grid construction term is evaluated.
+- A grid optional construction factor may be evaluated once or may not be evaluated, when the containing grid construction term is evaluated.
+- A grid repetitive construction factor is to be evaluated one or more times in succession, when the containing grid construction term is evaluated.
+- A grid optional repetitive construction factor may be evaluated one or more times in succession, or may not be evaluated, when the containing grid construction term is evaluated.
+
+**Table 1 – Types of grid construction expression**
+
+| Type of expression             | Attribute                  | Type of atom                |
+|--------------------------------|----------------------------|-----------------------------|
+| Grid interval expression       | “grid interval dimensions” | Interval indicator          |
+| Grid gutter expression         | “grid gutters”             | Gutter indicator            |
+| Grid line expression           | “grid lines”               | Line characteristic         |
+| Line characteristic expression | –                          | Line segment characteristic |
+
+## 11.2 Attributes with grid construction expressions as values
+
+This Specification defines three attributes with parameters whose permissible value is a grid construction expression:
+
+- a) grid interval dimensions (see 12.1.4);
+- b) grid gutters (see 12.1.3);
+- c) grid lines (see 12.1.5).
+
+Each attributes is associated with a different type of grid construction expression (see Table 1):
+
+- a) The permissible value for a parameter of the attribute “grid interval dimensions” is a grid interval expression (see 11.3). The layout process evaluates this attribute specified for a grid frame class description, and determines the grid interval dimensions of the layout grid within the grid frame to which this attribute applies. The determined grid intervals are expressed as a grid interval expression, and then the expression is specified for the grid frame description as a value for the same attribute.  
+The imaging process evaluates the attribute “grid interval dimensions” specified for a grid frame description, and gets the positions where it shall image the layout grid lines involved in its layout grid.
+- b) The permissible value for a parameter of the attribute “grid gutters” is a grid gutter expression (see 11.5). The layout process evaluates this attribute, and calculates available areas for frames immediately subordinate to the grid frame to which the attribute applies.
+- c) The permissible value for a parameter of the attribute “grid lines” is a grid line expression (see 11.7). The layout process evaluates this attribute specified for a grid frame class description, and determines the way in which the imaging process shall image the layout grid lines within the grid frame to which this attribute applies. This way of presenting the layout grid lines is expressed as a grid line expression, and then the expression is specified for the grid frame description as a value of the same attribute.  
+The imaging process evaluates the attribute “grid lines”, and images layout grid lines of the layout grid within the grid frame.
+
+## 11.3 Grid interval expressions
+
+The value of a *grid interval expression* is an *interval indicator* (see 11.4). A grid interval expression may be a value of a parameter of the attribute “grid interval dimensions”.
+
+The attribute “grid interval dimensions” specifies the distances or a rule to determine distances between consecutively numbered major / minor layout grid lines (called the *major / minor grid interval dimension*). This attribute consists of two parameters “major interval dimensions” and “minor interval dimensions”, which respectively specify the dimensions of the major and minor grid intervals of the layout grid within the grid frame to which the attribute is applied.
+
+Evaluation of a grid interval expression specified for the parameter “major / minor interval dimensions” may produce either an empty sequence or a sequence of interval indicators. The length of the derived sequence shall be the same as the major / minor grid size of the layout grid, namely the number of the major / minor grid intervals within the layout grid. Each interval indicator in the sequence specifies the dimension of an individual grid interval: the  $i$ -th interval indicator in the sequence specifies the  $i$ -th major / minor grid interval dimension of the layout grid, namely the distance between  $(i - 1)$ -th and  $i$ -th major / minor layout grid lines.
+
+NOTE – The deterministic condition of the grid construction expression provides for the unique sequence of interval indicators for the given major / minor size of the layout grid.
+
+Whenever the layout process reaches a grid logical object, the process evaluates the attribute “grid frame classes”, if it exists, applied to the grid logical object, and generates one or more grid frames in accordance with the construction expression specified for the attribute. At the same time, the process shall generate a layout grid within each generated grid frame so that this layout grid shall include as many major / minor grid intervals as the logical grid associated with the grid logical object does (see 9.2). Thus, the major and minor sizes of the layout grid are derived from those of the associated logical grid.
+
+## 11.4 Interval indicators
+
+### Constituents:
+
+Terminal factors for grid interval expressions.
+
+### Structure:
+
+One of the parameters “fixed dimension”, “rule B” or “proportional”.
+
+The parameter “rule B” is structured into two optional sub-parameters, “minimum dimension” and “maximum dimension”.
+
+The parameter “proportional” is structured into three optional sub-parameters, “group”, “imaginary dimension” and “default dimension”.
+
+### Permissible values:
+
+For the parameter “fixed dimension”: a non-negative integer.
+
+For the sub-parameters of the parameter “rule B”:
+
+- “minimum dimension”: a non-negative integer;
+- “maximum dimension”: either a non-negative integer or ‘infinitely large’.
+
+For the sub-parameters of the parameter “proportional”:
+
+- “group”: a non-negative integer;
+- “imaginary dimension”: a non-negative integer;
+- “default dimension”: either a non-negative integer or ‘null’.
+
+### Default values:
+
+For the sub-parameters of the parameter “rule B”:
+
+- “minimum dimension”: 0;
+- “maximum dimension”: ‘infinitely large’.
+
+For the sub-parameters of the parameter “proportional”:
+
+- “group”: 0;
+- “imaginary dimension”: 1;
+- “default dimension”: ‘null’.
+
+### Definition:
+
+An interval indicator is one of the following:
+
+#### a) *The parameter “fixed dimension”*
+
+The parameter “fixed dimension” specifies that the dimension of the relevant grid interval to which this interval indicator applies shall be the value specified for this parameter, measured in scaled measurement units (SMU).
+
+#### b) *The parameter “rule B”*
+
+The parameter “rule B” specifies that the dimension of the relevant grid interval shall be determined so that:
+
+- the interval dimension shall be within the range between the value specified for the sub-parameters “minimum dimension” and “maximum dimension”;
+- the interval dimension shall be large enough for the immediately subordinate entry frames which intersect the grid interval.
+
+The detailed definitions for the sub-parameters “minimum dimension” and “maximum dimension” are as follows:
+
+- The sub-parameter “minimum dimension” specifies the lower limit for the relevant grid interval dimension. The grid interval dimension shall not be smaller than this lower limit.
+- The sub-parameter “maximum dimension” specifies an upper limit for the relevant grid interval dimension. The grid interval dimension shall not exceed this upper limit.
+
+If the parameter maximum dimension specifies the value ‘infinitely large’, then there shall be no upper limit for the grid interval dimension.
+
+In addition to these constraints, the interval dimension is subject to constraints on the grid dimensions of the relevant layout grid. Such constraints are specified by the attribute “grid dimensions” applied to the grid frame (see 12.1.2):
+
+- 1) If the parameter “major / minor dimension” of this attribute specifies a non-negative integer, the major / minor dimension of this layout grid shall be the specified value.
+- 2) If the parameter “major / minor dimension” of this attribute specifies the value ‘expansive’, the major / minor dimension of this layout grid shall be the same as the dimension of the area available for the placement of the layout grid in the direction of the major / minor path.
+
+In both cases, where the attribute “grid dimensions” specifies some fixed value for the grid dimension in the same direction as that of the relevant grid interval, the dimension of this grid interval may take an arbitrary value, provided that:
+
+- the total amount of all the grid interval dimensions in the relevant direction is constrained to be this fixed value;
+  - each grid interval dimension in the relevant direction satisfies the constraints imposed by the interval indicator applied to it.
+- 3) If the parameter “major / minor dimension” of this attribute specifies the value ‘rule B’, there exists no constraint on the major / minor grid dimension except for those imposed by the area available for the relevant layout grid.
+
+In this case, the interval dimension shall be a *minimal dimension*. Minimal dimensions for the grid intervals entirely provide an instance of minimal layout of the layout grid. For the details of the minimal layout, refer to 9.1.12.
+
+#### c) *The parameter “proportional”*
+
+The parameter “proportional” specifies that the relevant grid interval dimension to which this interval indicator applies shall be determined so that:
+
+- the interval dimension shall be in specified proportions to other particular grid interval dimensions;
+- the interval dimension shall be large enough for the immediately subordinate entry frame intersecting the grid interval concerned.
+
+The definition of the sub-parameters are as follows:
+
+- The sub-parameter “group” specifies the group of grid intervals whose dimensions are to be determined in proportion to the relevant grid interval dimension.
+
+Within the layout grid, this group consists of those grid intervals such that:
+
+- they are all in the same direction;
+- all the interval indicators that apply to them commonly specify the parameter “proportional”;
+
+- these interval indicators specify the same value for the sub-parameter “group” as the relevant interval indicator does.
+- The sub-parameter “imaginary dimension” specifies the dimension of the grid interval measured in a particular imaginary measurement unit. This imaginary measurement unit is shared by all the grid intervals that belong to the same group.
+
+The layout process shall independently determine the actual dimension for the imaginary measurement unit proper to each individual group of grid intervals. This actual dimension shall be measured in scaled measurement units. Thereafter, the layout process shall determine the dimension of each grid interval that belongs to the group concerned so that:
+
+- the dimension shall be the product of the determined dimension of the relevant imaginary measurement unit and the value specified for the sub-parameter “imaginary dimension” of the interval indicator applied to this grid interval.
+- The sub-parameter “default dimension” specifies the default dimension which the grid interval shall take when no entry frame intersects it.
+
+If this parameter specifies a value of a non-negative integer, the grid interval dimension shall be this specified value, measured in scaled measurement units, irrespective of the dimensions of the other grid intervals in the same group.
+
+If this parameter specifies the value ‘null’, the dimension of the grid interval shall be always determined so as to keep the specified proportions to the dimensions of the other grid intervals in the same group, no matter whether any entry frames intersect it.
+
+In addition to these constraints, the actual dimension of the imaginary measurement unit shall be subject to the constraints imposed by the attribute “grid dimensions”, in the same way as stated in the case of the value “rule B”.
+
+## 11.5 Grid gutter expressions
+
+The value of a *grid gutter expression* is a *gutter indicators*. A grid gutter expression may be a value of a parameter of the attribute “grid gutters”.
+
+The attribute “grid gutters” specifies the gutter space width around major and minor grid lines within the grid frame to which the attribute is applied. The attribute consists of two parameters “around major grid lines” and “around minor grid lines” which respectively specify the gutter space width around major and minor layout grid lines.
+
+Evaluation of a grid gutter expression specified for the parameter “around major / minor grid lines” may produce either an empty sequence or a sequence of gutter indicators. The length of the derived sequence is the same as the number of the major / minor layout grid lines within the layout grid concerned.
+
+Each gutter indicator in the sequence specifies the gutter space width around an individual layout grid line: the *i*-th gutter indicator in the sequence specifies the gutter space width around the *i*-th major / minor grid line.
+
+## 11.6 Gutter indicators
+
+### Constituents:
+
+Terminal factors for grid gutter expressions.
+
+### Structure:
+
+Consists of two optional parameters: “width”, “precedence”.
+
+### Permissible values:
+
+- “width”: a non-negative integer (SMU);
+- “precedence”: a non-negative integer.
+
+### Default values:
+
+- “width”: 0;
+- “precedence”: 0.
+
+### Definition:
+
+A gutter indicator consists of two optional parameters:
+
+- The parameter “width” specifies the gutter space width around the layout grid line to which the gutter indicator is applied. The width is measured in scaled measurement units.
+
+- If two or more layout grid lines occupy the same position within the grid frame, the same number of gutter indicators are applicable in determining the gutter space width around the line into which those layout grid lines merge. In such degenerate cases, the layout process takes account of the parameter “precedence” associated with those gutter indicators:
+  - a) among those gutter indicators applicable, the one having the highest “precedence” shall be applied;
+  - b) if two or more gutter indicators are associated with the highest “precedence”, the last in the sequential order shall be applied.
+
+## 11.7 Grid line expressions
+
+A *grid line expressions* is a *line characteristics*.
+
+A grid line expression may be a value of the parameters “major grid lines” and “minor grid lines” of the attribute “grid lines”. The parameter “major / minor grid lines” specifies a set of sequences of line segment characteristics each of which describes the way in which each individual major / minor grid line is to be imaged.
+
+A line segment characteristic is a triplet of a line width, line type and line colour, and is applied to an individual grid line segment (see 9.1.4) forming part of a layout grid line. Thus, when a layout grid line is imaged, it may be a sequence of line segments each of which may be imaged in a different way.
+
+Direct evaluation of a grid line expression specified for the parameter “major / minor grid lines” may produce a sequence of one or more line characteristics. The length of the derived sequence is the same as the number of the major / minor layout grid lines within the layout grid. Each line characteristic in the sequence is applied to an individual layout grid line: the *i*-th line characteristic in the sequence is applied to the *i*-th major / minor layout grid line.
+
+## 11.8 Line characteristics
+
+### Constituents:
+
+Terminal factors for grid line expressions.
+
+### Structure:
+
+Consists of two optional parameters: “expression” and “precedence”.
+
+### Permissible values:
+
+- “expression”: a line characteristic expression;
+- “precedence”: a non-negative integer.
+
+### Default value:
+
+- “expression”: the grid optional repetitive construction factor which is the default line segment characteristic (see 11.10);
+- “precedence”: 0.
+
+### Definition:
+
+A line characteristic consists of two optional parameters:
+
+- The parameter “expression” takes as its value a line characteristic expression, and the effect is as described in 11.9.
+- If two or more layout grid lines merge into a single line, that same number of line characteristics are applicable to the single line into which those layout grid lines merge. In such degenerate cases, the layout process takes the parameter “precedence” associated with those line characteristics into account:
+  - a) among the line characteristics applicable, the one having the highest “precedence” shall be applied;
+  - b) if two or more line characteristics are associated with the highest “precedence”, the last in the sequential order shall be applied.
+
+## 11.9 Line characteristic expressions
+
+A *line characteristic expressions* is a *line segment characteristics*.
+
+Evaluation of a grid line expression may produce either an empty sequence or a sequence of line characteristics each of which includes one line characteristic expression. Each line characteristic expression in the sequence is applied to an individual major / minor layout grid line in order to determine the way in which it is to be imaged.
+
+Evaluation of a line characteristic expression produces a sequence of one or more line segment characteristics. The length of the derived sequence is the same as the number of the *grid line segments* composing the layout grid line.
+
+Consecutively numbered minor / major layout grid lines may merge into a single line, and therefore the line segment delimited by these grid lines may degenerate into a point. In such cases, the point shall be counted as a line segment. Hence, the number of the line segment composing a layout grid line is the same as the number of the minor / major sizes of the layout grid concerned.
+
+Each line segment characteristic in the sequence specifies the line width, line type and line colour of an individual grid line segment of the layout grid line to which the line characteristic expression is applied: the  $j$ -th line segment characteristic in the sequence specifies the line width, line type and line colour of the  $j$ -th line segment of the major / minor layout grid line, where the  $j$ -th line segment of the layout grid line is between the  $(j - 1)$ -th and  $j$ -th minor / major layout grid lines.
+
+## 11.10 Line segment characteristics
+
+### Constituents:
+
+Terminal factors for line characteristic expressions.
+
+### Structure:
+
+Consists of three optional parameters: “line width”, “line type”, “line colour”.
+
+The parameter “line colour”, if specified, is a choice between two sub-parameters: “implementation defined” and “colour expression”. The sub-parameter “implementation defined” is not substructured. The sub-parameter “colour expression” is structured as defined for the colour expressions in 9.1.4.1 of ITU-T Rec. T.412 | ISO/IEC 8613-2.
+
+### Permissible values:
+
+- “line width”: a non-negative integer (SMU);
+- “line type”: one of ‘solid’, ‘dashed’, ‘dash-dot’, ‘dash-dot-dot’, ‘double’ and ‘invisible’;
+- “line colour”:
+  - “implementation defined”: ‘implementation-defined’;
+  - “colour expression”: a colour expression as defined in 9.1.4.1 of ITU-T Rec. T.412 | ISO/IEC 8613-2.
+
+### Default value:
+
+Each of the parameters is independently defaultable.
+
+For the parameters “line width” and “line type”:
+
+- “line width”: 0;
+- “line type”: ‘solid’.
+
+For the parameter “line colour”, the default value is the sub-parameter “colour expression” with the sub-sub-parameters:
+
+- “colour access mode”: ‘direct’;
+- “colour space id”: 0;
+- “colour specification”: 1, 1, 1;
+- “colour tolerance”:
+  - “unspecified tolerance”: ‘infinite’.
+
+NOTE – The default value for a colour expression is a white colour in RGB space without limit on tolerance.
+
+### Definition:
+
+A line segment characteristic is applied to either a grid line segment of a layout grid line or a supplementary line, and determines its line width, line type and line colour.
+
+The parameter “line colour” specifies the line colour. It either has the value ‘implementation-defined’ (a value that is distinguishable from the colour visible in the layout object) or is given in terms of a colour expression as defined in 9.1.4.1 of ITU-T Rec. T.412 | ISO/IEC 8613-2. In the case of an indexed colour expression the relevant colour table is specified in the attribute “object colour table” applied to the grid frame that includes the grid line segment or the supplementary line.
+
+# 12 Attribute definitions
+
+## 12.1 Layout attributes
+
+### 12.1.1 Frame alignment point
+
+#### **Constituents:**
+
+Frame component descriptions.
+
+#### **Classification:**
+
+Non-mandatory for object class descriptions.
+
+Defaultable for object descriptions.
+
+#### **Structure:**
+
+One of the parameters: “subordinate dependent”, “fixed position”, “variable position”.
+
+The parameter “fixed position” is structured into two optional sub-parameters: “vertical position”, “horizontal position”.
+
+The parameter “variable position” is structured into two optional sub-parameters: “vertical alignment”, “horizontal alignment”.
+
+#### **Permissible values:**
+
+For the parameter “subordinate dependent”: ‘first’, ‘last’.
+
+For the parameter “fixed position”:
+
+- “vertical position”: any integer;
+- “horizontal position”: any integer.
+
+For the parameter “variable position”:
+
+- “vertical alignment”: ‘top’, ‘centre’, ‘bottom’;
+- “horizontal alignment”: ‘left’, ‘centre’, ‘right’.
+
+#### **Default value:**
+
+If no value is specified, the default value is the parameter “subordinate dependent” with the value ‘first’.
+
+##### **Definition:**
+
+**12.1.1.1** The layout process shall take this attribute into account only when applied to a frame subordinate to some grid frame.
+
+This attribute specifies the position of the alignment point associated with the relevant frame to which the attribute applies.
+
+**12.1.1.2** The parameter “subordinate dependent” specifies that the alignment point of the relevant frame shall be located on the alignment point associated with one of the immediately subordinate layout objects, no matter whether it is a frame or a block:
+
+- if the parameter specifies the value ‘first’, then the alignment point of the relevant frame shall occupy the same position as the alignment point of the first immediately subordinate layout object in the sequential layout order;
+- if the parameter specifies the value ‘last’, then the alignment point of the relevant frame shall occupy the same position as the alignment point of the last immediately subordinate layout object in the sequential layout order.
+
+**12.1.1.3** When the attribute specifies the parameter “fixed position”, the sub-parameter “vertical / horizontal position” specifies the vertical / horizontal distance of the alignment point from the reference point of the relevant frame, measured in scaled measurement units.
+
+The vertical position is measured in the top-to-bottom direction:
+
+- If the sub-parameter “vertical position” specifies a positive / negative integer, the alignment point shall be located beneath / above the reference point.
+
+The horizontal position is measured in the left-to-right direction:
+
+- If the sub-parameter “horizontal position” specifies a positive / negative integer, the alignment point shall be located on the right / left of the reference point.
+
+An alignment point specified by the parameter “fixed position” may fall outside the relevant frame.
+
+If this parameter does not specify a value for any of its sub-parameters, then the value zero is assumed for each sub-parameter for which a value is not specified.
+
+**12.1.1.4** If the attribute specifies the parameter “variable position”, the sub-parameter “vertical / horizontal alignment” specifies the vertical / horizontal position of the alignment point:
+
+- If the sub-parameter “vertical alignment” specifies the value ‘top’ / ‘bottom’, then the alignment point shall be located on the top / bottom edge of the relevant frame.  
+If the sub-parameter specifies the value ‘centre’, then the alignment point shall be located equidistant from the top and bottom edges of the relevant frame.
+- If the sub-parameter “horizontal alignment” specifies ‘left’ / ‘right’, then the alignment point shall be located on the left / right edge of the relevant frame.  
+If the sub-parameter specifies the value ‘centre’, then the alignment point shall be located equidistant from the right and left edges of the relevant frame.
+
+NOTE – The left / right edge of the frame may be different from the left-hand / right-hand edge. The former is defined absolutely, while the latter is defined relative to the layout path (see 7.3.3 of ITU-T Rec. T.412 | ISO/IEC 8613-2).
+
+An alignment point specified by the parameter “variable position” is always located within the relevant frame.
+
+If this parameter does not specify a value for any of the sub-parameters, then the value ‘centre’ is assumed for each sub-parameter for which a value is not specified.
+
+### 12.1.2 Grid dimensions
+
+#### Constituents:
+
+Grid frame component descriptions.
+
+#### Classification:
+
+Non-mandatory for object class descriptions.
+
+Defaultable for object descriptions.
+
+#### Structure:
+
+Consists of two optional parameters: “major dimension” and “minor dimension”.
+
+#### Permissible values:
+
+For each parameter: one of a non-negative integer (SMU), ‘rule B’, ‘expansive’.
+
+#### Default value:
+
+Each of the parameters is independently defaultable.
+
+For each parameter: ‘rule B’.
+
+#### Definition:
+
+**12.1.2.1** The layout process shall take this attribute into account only when the relevant grid frame to which this attribute applies is referred to by an instance of the attribute “grid frame classes” which applies to some grid logical object (see 12.2.3).
+
+This attribute specifies the dimensions of the edges of the layout grid within the relevant grid frame.
+
+The parameter “major / minor dimension” specifies the dimension of the edges parallel to the major / minor path of the grid frame. This dimension is equal to the distance between the 0-th and last major / minor layout grid lines.
+
+**12.1.2.2** If the parameter “major / minor dimension” specifies a non-negative integer, the dimension of the edges shall be the value specified by this parameter.
+
+**12.1.2.3** If the parameter “major / minor dimension” specifies the value ‘rule B’, the dimension of the edges shall be determined in accordance with the attribute “grid interval dimensions” applied to the same grid frame. The attribute “grid interval dimensions” specifies the major / minor grid interval dimensions, namely the distances between consecutively numbered major / minor layout grid lines within the grid frame. Therefore, the dimension of the edges parallel to the major / minor path shall be coincident with the total of all the major / minor grid interval dimensions.
+
+**12.1.2.4** If the parameter “major / minor dimension” specifies the value ‘expansive’, the layout grid shall expand to the available area within the relevant grid frame, in the direction of the major / minor path.
+
+**12.1.2.5** No matter which value is specified for this attribute, the grid shall be placed within the relevant grid frame. In addition, if the relevant grid frame has a border free space, the grid shall not fall within the border free space.
+
+### 12.1.3 Grid gutters
+
+#### Constituents:
+
+Grid frame component descriptions.
+
+#### Classification:
+
+Non-mandatory for object class descriptions.
+
+Defaultable for object descriptions.
+
+#### Structure:
+
+Consists of two optional parameters: “around major grid lines” and “around minor grid lines”.
+
+#### Permissible values:
+
+For each parameter: a grid gutter expression.
+
+#### Default value:
+
+Each of the parameters is independently defaultable.
+
+For each parameter: the grid optional repetitive construction factor which is the default gutter indicator.
+
+For the parameters of the default gutter indicator:
+
+- “width”: 0;
+- “precedence”: 0.
+
+#### Definition:
+
+**12.1.3.1** The layout process shall take this attribute into account only when the relevant grid frame to which this attribute applies is referred to by an instance of the attribute “grid frame classes” which applies to some grid logical object (see 12.2.3).
+
+This attribute consists of two parameters: “around major grid lines” and “around minor grid lines”. The parameter “around major / minor grid lines” specifies the gutter space width around the major / minor grid lines within the relevant grid frame to which this attribute is applied.
+
+A gutter space around a layout grid line is a rectangular area within the layout grid, delimited by two lines running parallel to the layout grid line concerned, such that the layout grid line is equidistant from those two edging lines. The width of the gutter space is defined as the distance between those two edging lines (see Figure 9).
+
+The layout process shall take gutter spaces into account in determining the area available for placement of an entry frame: if an entry frame is bound to a layout grid rectangle, the entry frame shall be excluded from the gutter spaces reserved around the four edges of the grid rectangle.
+
+![Diagram of a grid layout showing gutter spaces. The grid is defined by major grid lines (solid lines) and minor grid lines (dashed lines). The gutter spaces are indicated by arrows at the top with values: 2, 4, 4, 4, 4, 4, 8. A 'Major path' arrow points to the right below the grid. The text 'TISO5120-95/d09' is at the bottom right of the grid. Below the diagram, the text reads: 'Grid gutters around major grid lines = SEQ({2,0}, REP({4,0}), {8,0})'.](4ae4505e885586e481a3ad3bff5198b7_img.jpg)
+
+TISO5120-95/d09
+
+Major path
+
+Grid gutters around major grid lines = SEQ({2,0}, REP({4,0}), {8,0})
+
+Diagram of a grid layout showing gutter spaces. The grid is defined by major grid lines (solid lines) and minor grid lines (dashed lines). The gutter spaces are indicated by arrows at the top with values: 2, 4, 4, 4, 4, 4, 8. A 'Major path' arrow points to the right below the grid. The text 'TISO5120-95/d09' is at the bottom right of the grid. Below the diagram, the text reads: 'Grid gutters around major grid lines = SEQ({2,0}, REP({4,0}), {8,0})'.
+
+Figure 9 – Gutter spaces
+
+**12.1.3.2** The parameter “around major / minor grid lines” specifies the grid gutter space width around the major / minor layout grid lines.
+
+Evaluation of the grid gutter expression specified for the parameter “around major / minor grid lines” shall produce a sequence of one or more gutter indicators. The number of gutter indicators in this derived sequence shall be the same as the number of the major / minor layout grid lines within the grid frame (see 11.5): the *i*-th gutter indicator in the sequence specifies the gutter space width around the *i*-th major / minor layout grid line.
+
+Each gutter indicator consists of two optional parameters: “width” and “precedence”. For the definition of these parameters, refer to 11.6.
+
+### 12.1.4 Grid interval dimensions
+
+#### Constituents:
+
+Grid frame component descriptions.
+
+#### Classification:
+
+Non-mandatory.
+
+#### Structure:
+
+Consists of two parameters: “major interval dimensions” and “minor interval dimensions”.
+
+#### Permissible values:
+
+For each parameter: a grid interval expression.
+
+#### Definition:
+
+NOTE – In this definition, the scope of the symbol / is the entire text (see 5.2).
+
+**12.1.4.1** The layout process shall take this attribute into account only when the relevant grid frame to which this attribute applies is referred to by an instance of the attribute “grid frame classes” which applies to some grid logical object (see 12.2.3).
+
+This attribute consists of two parameters: “major interval dimensions” and “minor interval dimensions”. The parameter “major / minor interval dimensions” specifies the dimensions of major / minor grid intervals. The dimension of a major / minor grid interval, called also a *major / minor grid interval dimension*, is the distance between two consecutively numbered major / minor layout grid lines.
+
+**12.1.4.2** If an object class description specifies this attribute, arbitrary grid interval expressions may be specified for the parameters.
+
+In contrast, if an object description specifies this attribute, the grid interval expression specified for the parameter “major / minor grid interval” shall be of the grid sequence construction type composed of interval indicators. Furthermore:
+
+- each interval indicator involved in this grid interval expression shall specify the parameter “fixed dimension” (see 11.4);
+- the number of the interval indicators involved in this grid interval expression shall be the same as the major / minor grid size of the relevant layout grid.
+
+By evaluating this attribute specified for the object description, the imaging process shall determine the absolute dimensions of the grid intervals as well as the grid sizes of the layout grid (see 9.1.5). If the attribute is omitted from the object description, the imaging process shall regard the grid frame as an ordinary frame which does not include any layout grid.
+
+**12.1.4.3** Evaluation of the grid interval expression specified for the parameter “major / minor interval dimensions” shall produce a sequence of one or more interval indicators (see 11.3). The number of interval indicators involved in the derived sequence shall be the same as the major / minor size of the layout grid within the relevant grid frame.
+
+The  $i$ -th interval indicator in the derived sequence specifies the dimension of the  $i$ -th major / minor grid interval (see 9.1.8).
+
+Each interval indicator is one of the following:
+
+- a) the parameter “fixed dimension”;
+- b) the parameter “rule B” with two optional sub-parameters: “minimum dimension” and “maximum dimension”;
+- c) the parameter “proportional” with three optional sub-parameters: “group”, “imaginary dimension” and “default dimension”.
+
+For the definition of these parameters and sub-parameters, refer to 11.4.
+
+**12.1.4.4** If an object description specifies this attribute, evaluation of the grid interval expression specified for the parameter “major / minor interval dimensions” shall produce the unique sequence of interval indicators such that:
+
+- the number of the interval indicators involved in the sequence is the same as the major / minor grid size of the relevant layout grid;
+- each interval indicator specifies the parameter “fixed dimension”.
+
+The  $i$ -th interval indicator in the sequence determines the  $i$ -th major / minor grid interval dimension, measured in scaled measurement units.
+
+### 12.1.5 Grid lines
+
+#### Constituents:
+
+Grid frame component descriptions.
+
+#### Classification:
+
+Non-mandatory for object class descriptions.
+
+Defaultable for object descriptions.
+
+#### Structure:
+
+Consists of the two optional parameters: “major grid lines” and “minor grid lines”.
+
+#### Permissible values:
+
+For each parameter: a grid line expression.
+
+#### Default value:
+
+Each of the parameters is independently defaultable.
+
+For each parameter: the grid optional repetitive construction factor which is the default line characteristic.
+
+For the parameters of the default line characteristic:
+
+- “expression”: the grid optional repetitive construction factor which is the default line segment characteristic;
+
+- “precedence”: 0.
+
+For the parameters “line width” and “line type” of the default line segment characteristic:
+
+- “line width”: 0;
+- “line type”: ‘solid’.
+
+For the parameter “line colour” of the default line segment characteristic, the default value is the sub-parameter “colour expression” with the sub-sub-parameters:
+
+- “colour access mode”: ‘direct’;
+- “colour space id”: 0;
+- “colour specification”: 1, 1, 1;
+- “colour tolerance”:
+  - “unspecified tolerance”: ‘infinite’.
+
+NOTE 1 – The default value for a colour expression is a white colour in RGB space without limit on tolerance.
+
+##### **Definition:**
+
+NOTE 2 – In this definition, the scope of the symbol / is the entire text (see 5.2).
+
+**12.1.5.1** The layout process shall take this attribute into account only when the grid frame to which this attribute applies is referred to by an instance of the attribute “grid frame classes” which applies to some grid logical object (see 12.2.3).
+
+The imaging process shall take this attribute into account only when the relevant object description specifies the attribute “grid interval dimensions” (see 12.1.4).
+
+NOTE – If the object description specifies the attribute “grid interval dimensions”, the grid interval expression specified for each parameter of this attribute shall be of the grid sequence construction type consisting of interval indicators. In particular, the number of the interval indicators involved in the grid interval expression specified for the parameter “major / minor interval dimensions” shall be the same as the major / minor size of the layout grid concerned.
+
+This attribute consists of two parameters: “major grid lines” and “minor grid lines”. The parameter “major / minor grid lines” specifies the way in which major / minor layout grid lines are to be imaged. More precisely, this parameter specifies the line width, line type and line colour applicable for each individual grid line segment of the major / minor layout grid lines.
+
+**12.1.5.2** For the parameter “major / minor grid lines”, a grid line expression is specified.
+
+Evaluation of the grid line expression specified for this parameter shall finally produce a set of sequences each of which consists of one or more line segment characteristics (see 11.10). Principally, each line segment characteristic is applied to each individual *grid line segment* of the major / minor layout grid lines, and determines its line width, line type and line colour, provided that a grid line segment is a segment of a major / minor layout grid line delimited by two consecutively numbered minor / major layout grid lines (see 9.1.4).
+
+Direct evaluation of the grid line expression specified for this parameter shall produce a sequence of line characteristic expressions each of which is associated with a non-negative integer, called a *precedence* (see 11.8). The number of line characteristic expressions in the sequence shall be the same as the number of the major / minor layout grid lines within the grid frame (see 11.8), and the *i*-th line characteristic expression in the sequence shall be applied to the *i*-th major / minor layout grid line in order to determine its appearance.
+
+If two or more major / minor layout grid line occupy the same position within the grid frame, the same number of line characteristic expressions are applicable to the single line into which those layout grid lines merge. In such degenerate cases, the precedence associated with each characteristic expression shall be taken into account:
+
+- a) among all the line characteristic expressions applicable, the one associated with the highest precedence shall be actually applied;
+- b) if there still exist more than one line characteristic expression associated with the highest precedence, the last one in their sequential order shall be applied.
+
+**12.1.5.3** Evaluation of the line characteristic expression applied to the *i*-th major / minor grid line shall produce a sequence of line segment characteristics. The number of line segment characteristics in the sequence shall be the same as the number of the minor / major grid intervals of the layout grid concerned (see 11.9).
+
+The *j*-th line segment characteristic in the sequence specifies the line width, line type and line colour applicable to the *j*-th grid line segment of the *i*-th major / minor layout grid line, where the *j*-th grid line segment is defined as the segment of the *i*-th major / minor layout grid line between the (*j* – 1)-th and *j*-th minor / major layout grid lines.
+
+Each line segment characteristic consists of three optional parameters “line width”, “line type” and “line colour”. For the definition of these parameters, refer to 11.10.
+
+**12.1.5.4** After the layout process evaluates the grid line expression specified for the parameter “major / minor grid lines”, it may modify the derived sequences of line segment characteristics:
+
+- if a grid line segment of a layout grid line is included in the interior of the layout grid rectangle to which some entry frame is bound, the layout process shall replace the line segment characteristic for the segment with one with the value ‘invisible’ specified for the parameter “line type”.
+
+Thereafter, the layout process shall modify the grid line expression specified for the parameter so that evaluation of the modified expression shall uniquely produce these modified sequences of line segment characteristics. The modified expression shall be the value of the parameter “major / minor grid lines” of the attribute “grid lines” specified for the object description.
+
+### 12.1.6 Grid position
+
+#### Constituents:
+
+Grid frame component descriptions.
+
+#### Classification:
+
+Non-mandatory for object class descriptions.
+
+Defaultable for object descriptions.
+
+#### Structure:
+
+Either the parameter “fixed position” or the parameter “variable position”.
+
+The parameter “fixed position” consists of two mandatory sub-parameters: “major position” and “minor position”.
+
+The parameter “variable position” consists of two optional sub-parameters: “major alignment” and “minor alignment”.
+
+#### Permissible values:
+
+For the parameter “fixed position”:
+
+- “major position”: a non-negative integer (SMU);
+- “minor position”: a non-negative integer (SMU).
+
+For the parameter “variable position”:
+
+- “major alignment”: ‘left-hand aligned’, ‘centred’, ‘right-hand aligned’;
+- “minor alignment”: ‘left-hand aligned’, ‘centred’, ‘right-hand aligned’.
+
+#### Default value:
+
+If no value is specified, the default value is the parameter “variable position” with the sub-parameters:
+
+- “major alignment”: ‘centred’;
+- “minor alignment”: ‘centred’.
+
+##### Definition:
+
+**12.1.6.1** The layout process shall take this attribute into account only when the relevant grid frame to which this attribute applies is referred to by an instance of the attribute “grid frame classes” which applies to some grid logical object (see 12.2.3).
+
+The imaging process shall take this attribute into account only when the relevant object description specifies the attribute “grid interval dimensions” (see 12.1.4).
+
+This attribute specifies the position of the associated layout grid within the relevant grid frame.
+
+**12.1.6.2** The *grid reference point* is one of the corners of the relevant grid frame. The *grid origin* is one of the corners of the layout grid. They are defined relative to the directions of the major and the minor paths within the grid frame.
+
+Table 2 provides the definition of the grid reference point and the grid origin.
+
+For example, when the attributes “major path” and “minor path” specify 270° and 90°, the grid origin and the grid reference point are the top-left corners of the layout grid and the grid frame respectively (see Figure 10).
+
+**Table 2 – Positions of grid origins and grid reference points**
+
+| Major path | Minor path | Position            |
+|------------|------------|---------------------|
+| 0°         | 90°        | Bottom-left corner  |
+| 0°         | 270°       | Top-left corner     |
+| 90°        | 90°        | Bottom-right corner |
+| 90°        | 270°       | Bottom-left corner  |
+| 180°       | 90°        | Top-right corner    |
+| 180°       | 270°       | Bottom-right corner |
+| 270°       | 90°        | Top-left corner     |
+| 270°       | 270°       | Top-right corner    |
+
+![Diagram illustrating the grid origin and grid reference point. A grid frame is shown with a 3x3 grid of cells. The grid origin is marked at the top-left corner of the grid. The grid reference point is marked at the top-left corner of the grid frame. The major path is indicated by a downward arrow, and the minor path is indicated by a rightward arrow. The grid position is marked at the top-left corner of the grid.](4e85fe330de2c4f5eea6de4b2a53c77f_img.jpg)
+
+The diagram shows a rectangular grid frame containing a 3x3 grid of cells. A 'Grid reference point' is located at the top-left corner of the frame. A 'Grid origin' is located at the top-left corner of the inner grid. A 'Grid position' is also indicated at the top-left corner of the inner grid. A dashed line connects the 'Grid reference point' to the 'Grid origin'. A 'Major path' arrow points downwards from the 'Grid reference point'. A 'Minor path' arrow points to the right from the 'Grid reference point'. The text 'Grid frame' is at the top right of the frame. The text 'TISO5130-95/d10' is at the bottom right of the frame.
+
+Diagram illustrating the grid origin and grid reference point. A grid frame is shown with a 3x3 grid of cells. The grid origin is marked at the top-left corner of the grid. The grid reference point is marked at the top-left corner of the grid frame. The major path is indicated by a downward arrow, and the minor path is indicated by a rightward arrow. The grid position is marked at the top-left corner of the grid.
+
+**Figure 10 – Grid origin and grid reference point**
+
+**12.1.6.3** If the attribute specifies the parameter “fixed position”, the sub-parameter “major / minor position” specifies the distance of the grid origin from the grid reference point, measured in the directions of the major / minor path. The direction of the major / minor path is specified by the attribute “major / minor path” applied to the relevant grid frame.
+
+The sub-parameter “major / minor position” shall specify a value so that the layout grid shall be placed within the relevant grid frame. If the grid frame has a border free space, this value shall be further constrained so that the layout grid shall not fall within the border free space.
+
+**12.1.6.4** If the attribute specifies the parameter “variable position”, the sub-parameter “major / minor alignment” specifies the alignment of the layout grid within the grid frame.
+
+The alignment specified by the sub-parameter “major / minor alignment” determines the position in the direction orthogonal to the major / minor path:
+
+- if the sub-parameter “major / minor alignment” specifies the value ‘left-hand aligned’, the layout grid shall be positioned as far as possible in the direction which traverses the major / minor path at right angles in an anticlockwise direction, without violating the border allowance of the grid frame;
+- if the sub-parameter “major / minor alignment” specifies the value ‘right-hand aligned’, the layout grid shall be positioned as far as possible in the direction which traverses the major / minor path at right angles in a clockwise direction, without violating the border allowance of the grid frame;
+- if the sub-parameter “major / minor alignment” specifies the value ‘centred’, the layout grid shall be centered in the direction of the minor / major path.
+
+For example, when the attribute “major path” specifies 0°, the alignment specified by the sub-parameter “major alignment” is as follows (see also Figure 11):
+
+- if the sub-parameter specifies the value ‘left-hand aligned’, the layout grid shall be located at the uppermost position as long as it does not fall within the border free space of the grid frame;
+- if the sub-parameter specifies the value ‘right-hand aligned’, the layout grid shall be located at the bottom position as long as it does not fall within the border free space of the grid frame;
+- if the sub-parameter specifies the value ‘centred’, the grid shall be so located that the distance between the top edge of the grid and that of the grid frame shall be the same as the distance between the bottom edge of the grid and that of the grid frame.
+
+If this parameter does not specify a value for any of the sub-parameters, the value ‘centred’ is assumed for each sub-parameter for which a value is not specified.
+
+![Figure 11 – Major alignment of grids. The figure shows three diagrams illustrating grid alignment within a frame. Each diagram consists of a large outer rectangle (the grid frame) and a smaller inner rectangle (the layout grid). 1. 'Left-hand aligned': The inner grid is positioned at the top-left corner of the outer frame. 2. 'Centred': The inner grid is centered within the outer frame. 3. 'Right-hand aligned': The inner grid is positioned at the bottom-right corner of the outer frame. Below each diagram is a horizontal arrow pointing to the right, labeled 'Major path'. The text 'TISO5140-95/d11' is located to the right of the third diagram.](396b969fe671a6ae5f086506b9c29718_img.jpg)
+
+Figure 11 – Major alignment of grids. The figure shows three diagrams illustrating grid alignment within a frame. Each diagram consists of a large outer rectangle (the grid frame) and a smaller inner rectangle (the layout grid). 1. 'Left-hand aligned': The inner grid is positioned at the top-left corner of the outer frame. 2. 'Centred': The inner grid is centered within the outer frame. 3. 'Right-hand aligned': The inner grid is positioned at the bottom-right corner of the outer frame. Below each diagram is a horizontal arrow pointing to the right, labeled 'Major path'. The text 'TISO5140-95/d11' is located to the right of the third diagram.
+
+Figure 11 – Major alignment of grids
+
+### 12.1.7 Indent – major; Indent – minor
+
+#### Constituents:
+
+Frame class descriptions.
+
+#### Classification:
+
+Non-mandatory.
+
+#### Permissible values:
+
+Any integer.
+
+##### Definition:
+
+NOTE – In this definition, the scope of the symbol / is the entire text (see 5.2).
+
+**12.1.7.1** The layout process shall take the attribute “indent – major / minor” into account only when applied to entry frames immediately subordinate to grid frames. Otherwise, the layout process shall ignore this attribute completely.
+
+If the attribute “reference line alignment – major / minor” specifies that the entry frame to which this attribute applies shall be aligned with other entry frames along some reference line, the distance of the alignment point of the entry frame from the reference line shall be the value specified by the attribute “indent – major / minor”.
+
+This distance is measured in scaled measurement units in the direction which traverses the major / minor path of the immediately superior grid frame at right angles in an anticlockwise direction.
+
+NOTE – Even if an entry frame is aligned with other entry frames along a reference line, the attribute “reference line alignment – major / minor” may not be applied to the entry frame (see 12.1.11).
+
+Hence, for example, if the attribute “major path” specifies 270°, and if the attribute “minor path” specifies 90°, then:
+
+- a positive value of the attribute “indent – major” specifies that the alignment point of the entry frame shall be located to the right of the reference line;
+- a negative value of the attribute “indent – major” specifies that the alignment point of the entry frame shall be located to the left of the reference line;
+- a positive value of the attribute “indent – minor” specifies that the alignment point of the entry frame shall be located above the reference line;
+- a negative value of the attribute “indent – minor” specifies that the alignment point of the entry frame shall be located below the reference line;
+- the value 0 of the attribute “indent – major / minor” specifies that the alignment point of the entry frame shall be located on the reference line (see Figure 12).
+
+![Figure 12: Indent – major. This diagram illustrates three rectangular entry frames aligned vertically relative to a central dashed 'Reference line'. The top frame is shifted to the left, with its alignment point (marked with an 'X') to the left of the reference line; the distance is labeled 'd' and the text 'Indent – major = d < 0' is shown. The middle frame is shifted to the right, with its alignment point to the right of the reference line; the distance is labeled 'd' and the text 'Indent – major = d > 0' is shown. The bottom frame is centered on the reference line, with its alignment point on the line; the text 'Indent – major = d = 0' is shown. A vertical arrow on the left labeled 'Major path' points downwards. A horizontal arrow at the bottom indicates the distance 'd' from the reference line to the alignment point. A legend at the bottom left shows 'X Alignment points'. The text 'TISO5150-95/d12' is at the bottom right.](a003ffe7299e0a48bceb7f1e45a4f1a3_img.jpg)
+
+Figure 12: Indent – major. This diagram illustrates three rectangular entry frames aligned vertically relative to a central dashed 'Reference line'. The top frame is shifted to the left, with its alignment point (marked with an 'X') to the left of the reference line; the distance is labeled 'd' and the text 'Indent – major = d < 0' is shown. The middle frame is shifted to the right, with its alignment point to the right of the reference line; the distance is labeled 'd' and the text 'Indent – major = d > 0' is shown. The bottom frame is centered on the reference line, with its alignment point on the line; the text 'Indent – major = d = 0' is shown. A vertical arrow on the left labeled 'Major path' points downwards. A horizontal arrow at the bottom indicates the distance 'd' from the reference line to the alignment point. A legend at the bottom left shows 'X Alignment points'. The text 'TISO5150-95/d12' is at the bottom right.
+
+Figure 12 – Indent – major
+
+### 12.1.8 Major path
+
+#### **Constituents:**
+
+Grid frame component descriptions.
+
+#### **Classification:**
+
+Non-mandatory for object class descriptions.
+
+Defaultable for object descriptions.
+
+#### **Permissible values:**
+
+A set of data elements defined for the attribute: ‘0°’, ‘90°’, ‘180°’, ‘270°’.
+
+#### **Representation:**
+
+In the interchange format, '0°', '90°', '180°', '270°' are represented by the character strings d0, d90, d180, d270.
+
+#### **Default value:**
+
+'270°'.
+
+##### **Definition:**
+
+The layout process shall take this attribute into account only when the relevant grid frame to which this attribute applies is referred to by an instance of the attribute "grid frame classes" which applies to some grid logical object (see 12.2.3).
+
+The imaging process shall take this attribute into account only when the relevant object description specifies the attribute "grid interval dimensions" (see 12.1.4).
+
+This attribute specifies the direction of progression of the allocation of the major grid lines within the relevant grid frame. The specified direction is relative to the horizontal direction.
+
+### **12.1.9 Minor path**
+
+#### **Constituents:**
+
+Grid frame component descriptions.
+
+#### **Classification:**
+
+Non-mandatory for object class descriptions.
+
+Defaultable for object descriptions.
+
+#### **Permissible values:**
+
+A set of data elements defined for the attribute: '90°', '270°'.
+
+#### **Representation:**
+
+In the interchange format, '90°', '270°' are represented by the character strings d90, d270.
+
+#### **Default value:**
+
+'90°'.
+
+##### **Definition:**
+
+The layout process shall take this attribute into account only when the relevant grid frame to which this attribute applies is referred to by an instance of the attribute "grid frame classes" which applies to some grid logical object (see 12.2.3).
+
+The imaging process shall take this attribute into account only when the relevant object description specifies the attribute "grid interval dimensions" (see 12.1.4).
+
+This attribute specifies the direction of progression of the allocation of the minor grid lines within the relevant grid frame. The specified direction is measured anticlockwise from the direction specified by the attribute "major path".
+
+### **12.1.10 Position**
+
+#### **Constituents:**
+
+Frame and block component descriptions.
+
+#### **Classification:**
+
+Non-mandatory for object class descriptions.
+
+Defaultable for object descriptions.
+
+#### **Structure:**
+
+Either, the parameter "fixed position", which has two sub-parameters: "horizontal position" and "vertical position", or the parameter "variable position", which has four optional sub-parameters: "offset", "separation", "alignment" and "fill order".
+
+The sub-parameter "offset" is structured into four optional sub-sub-parameters: "leading offset", "trailing offset", "left-hand offset", "right-hand offset".
+
+The sub-parameter “separation” is structured into three optional sub-sub-parameters: “leading edge”, “trailing edge”, “centre separation”.
+
+#### **Permissible values:**
+
+For the parameter “fixed position”:
+
+- “horizontal position”: a non-negative integer;
+- “vertical position”: a non-negative integer.
+
+For the parameter “variable position”:
+
+- for the sub-parameter “offset”, zero or more of “leading offset”, “trailing offset”, “left-hand offset”, “right-hand offset” may be specified in any instance of this sub-parameter. For each the permissible value is a non-negative integer;
+- for the sub-parameter “separation”, zero or more of “leading edge”, “trailing edge”, “centre separation” may be specified in any instance of this sub-parameter. For each the permissible value is a non-negative integer;
+  - for the sub-parameter “alignment”, the permissible values are ‘right-hand aligned’, ‘centred’, ‘left-hand aligned’;
+- for the sub-parameter “fill order”, the permissible values are ‘normal order’, ‘centre order’, ‘reverse order’.
+
+#### **Default value:**
+
+If no value is specified, the default value is the parameter “fixed position” with the sub-parameters:
+
+- “horizontal position”: 0;
+- “vertical position”: 0.
+
+##### **Definition:**
+
+**12.1.10.1** This attribute specifies the position of the layout object relative to the layout object at the next higher level in the hierarchical structure (i.e. the immediately superior page or frame).
+
+Two cases are to be considered, that of fixed position and that of variable position.
+
+**12.1.10.2** In the case of fixed position, the definition is given in 9.4.1.1 of ITU-T Rec. T.412 | ISO/IEC 8613-2.
+
+**12.1.10.3** The case of variable position may only be specified for frame class descriptions referred to in construction expressions from other frame class descriptions (see 9.3.2.1 of ITU-T Rec. T.412 | ISO/IEC 8613-2). Consequently, block component descriptions, frame descriptions and frame class descriptions referred to in construction expressions specified for page class descriptions may only specify fixed position.
+
+Three cases are further to be considered, according to which of the following applies to a frame whose position within the immediate superior frame shall be determined in accordance with this parameter:
+
+- the immediately superior frame is not a grid frame (case 1);
+- the frame is bound to a layout grid rectangle within the immediately superior grid frame (case 2);
+- the frame is not bound to any layout grid rectangle within the immediately superior grid frame (case 3).
+
+#### **12.1.10.4 Case 1**
+
+In this case, the sub-parameter “fill order” shall not specify ‘centre order’. For the definition of the sub-parameters “offset”, “separation”, “alignment” and “fill order” in this case, refer to 9.4.1.1 of ITU-T Rec. T.412 | ISO/IEC 8613-2.
+
+#### **12.1.10.5 Case 2**
+
+In this case, the relevant layout object to which this attribute applies is to be variably positioned within the particular layout grid rectangle to which the layout object is bound.
+
+Zero or more of the sub-parameters “offset”, “separation”, “alignment” and “fill order” are specified as follows:
+
+##### a) *offset*
+
+This sub-parameter constrains the area available for placement of the relevant entry frame within the layout grid rectangle to which the entry frame is bound.
+
+This sub-parameter specifies minimum amounts of offset between the boundary of the frame and the boundary of the layout grid rectangle.
+
+The sub-parameter is structured into four sub-sub-parameters: “leading offset”, “trailing offset”, “left-hand offset”, “right-hand offset”. These specify the minimum distance between the corresponding edge of the entry frame and the leading, trailing, left-hand and right-hand edge respectively of the layout grid rectangle to which the entry frame is bound.
+
+For each edge, the sub-sub-parameter specifies the amount of offset for that edge in scaled measurement units (for the names of the edges, refer to 9.1.9 of this Specification and 7.3.3 of ITU-T Rec. T.412 | ISO/IEC 8613-2).
+
+If the parameter “variable position” does not specify a value for this sub-parameter, or for any of its sub-sub-parameters, then the value zero is assumed for each sub-sub-parameter for which a value is not specified.
+
+##### b) *separation*
+
+This sub-parameter specifies minimum amounts of separation between this entry frame and the nearest adjacent entry frame which is bound to the same layout grid rectangle within the same immediate superior grid frame. The sub-parameter is structured into three sub-sub-parameters: “leading edge”, “trailing edge”, “centre separation”.
+
+The sub-sub-parameter “leading edge” specifies the minimum separation from the leading edge of the entry frame and the trailing edge of the next entry frame laid out with the same value for the sub-parameter “fill order” within the same layout grid rectangle.
+
+The sub-sub-parameter “trailing edge” specifies the minimum separation from the trailing edge of the entry frame and the leading edge of the immediately preceding entry frame laid out with the same value for the sub-parameter “fill order” within the same layout grid rectangle.
+
+Thus, a constraint on the separation of two adjacent frames which both have the same fill order, and are bound to the same layout grid rectangle, is that the separation shall be equal to, or greater than, the greater of the value of “leading edge” for the first of the entry frames in the direction of layout path and the value of “trailing edge” for the second of the entry frames.
+
+The sub-sub-parameter “centre separation” specifies the minimum separation between two frames which are laid out with different values for the sub-parameter “fill order” within the same layout grid rectangle.
+
+Thus, a constraint on the separation of two adjacent frames which have different fill orders, but are both bound to the same layout grid rectangle, is that the separation shall be equal to, or greater than, the greater of the values of “centre separation” specified for the two frames.
+
+For each edge, the sub-sub-parameter specifies the amount of separation for that edge in scaled measurement units (for the names of edges, refer to 9.1.9 of this Specification and 7.3.3 of ITU-T Rec. T.412 | ISO/IEC 8613-2).
+
+If the parameter “variable position” does not specify a value for this sub-parameter, or for any of its sub-sub-parameters, then the value zero is assumed for each sub-sub-parameter for which a value is not specified.
+
+##### c) *alignment*
+
+This sub-parameter specifies the alignment of the entry frame within the area available for positioning the entry frame inside the layout grid rectangle to which the entry frame is bound. The alignment is in the direction orthogonal to that specified by the attribute “layout path” of the immediately superior grid frame.
+
+This sub-parameter takes one of three values: ‘right-hand aligned’, ‘centred’, ‘left-hand aligned’.
+
+Subject to satisfying constraints on placement specified by:
+
+- the sub-parameter “offset” applied to this entry frame;
+- the attributes “reference line alignment – major” and “indent – major” applied to this entry frame and other sibling entry frames, if the layout path is parallel to, or opposite to, the major path;
+- the attributes “reference line alignment – minor” and “indent – minor” applied to this entry frame and other sibling entry frames, if the layout path is parallel to, or opposite to, the minor path;
+- the attribute “grid gutters” applied to the grid frame immediately superior to the entry frame.
+
+The values of alignment are defined as follows:
+
+- 1) if the value is ‘right-hand aligned’, then this entry frame is to be positioned as close as possible to the right-hand edge of the layout grid rectangle to which the entry frame is bound;
+- 2) if the value is ‘left-hand aligned’, then this entry frame is to be positioned as close as possible to the left-hand edge of the layout grid rectangle to which the entry frame is bound;
+
+- 3) if the value is 'centred', then this entry frame is to be positioned equidistant from the two positions at which the entry frame would be placed if the value were 'right-hand aligned' and 'left-hand aligned'.
+
+NOTE – If an entry frame is involved in reference line alignment, placement of the entry frame within the available area, which is specified by the sub-parameters "offset" and "separation" applied to it and the attribute "grid gutters" applied to the immediately superior grid frame (see 13.7.1), may be further restricted by the available area for other entry frames which are to be aligned with the relevant entry frame.
+
+If the parameter "variable position" does not specify a value for this sub-parameter, then the value 'right-hand-aligned' is assumed.
+
+##### d) *fill order*
+
+The sub-parameter "fill order" specifies how the entry frame is to be positioned within the layout grid rectangle to which the entry frame is bound, relative to the direction of the layout path of the immediately superior grid frame.
+
+The sub-parameter takes one of three values: 'normal order', 'reverse order', 'centre order'.
+
+Subject to satisfying constraints on placement specified by:
+
+- the sub-parameters "offset", "separation" applied to the entry frame;
+- the attributes "reference line alignment – major" and "indent – major" applied to this entry frame and other sibling entry frames, if the layout path is orthogonal to the major path;
+- the attributes "reference line alignment – minor" and "indent – minor" applied to this entry frame and other sibling entry frames, if the layout path is orthogonal to the minor path;
+- the attribute "grid gutters" applied to the grid frame immediately superior to the entry frame.
+
+The values of fill order are defined as follows:
+
+- 1) If the value is 'normal order', then this entry frame is grouped together with any other sibling entry frames bound to the same layout grid rectangle and specifying this value.
+
+These entry frames are positioned after each other in the direction of the layout path of their common immediately superior grid frame. The order in which they are positioned in the direction of the layout path is the same as their sequential layout order.
+
+Additionally, each frame in the group is positioned as far as possible in the direction opposite to the layout path so that the first entry frame in the group shall be located closest to the trailing edge of the layout grid rectangle, of all the entry frames bound to this layout grid rectangle.
+
+- 2) If the value is 'reverse order', then this entry frame is grouped together with any other sibling entry frames bound to the same layout grid rectangle and specifying this value.
+
+These entry frames are positioned after each other in the direction of the layout path of their common immediately superior grid frame. The order in which they are positioned in the direction of the layout path is the same as their sequential layout order.
+
+Additionally, each frame in the group is positioned as far as possible in the direction of the layout path so that the last entry frame in the group shall be located closest to the leading edge of the layout grid rectangle, of all the entry frames bound to this layout grid rectangle.
+
+- 3) If the value is 'centre order', then this entry frame is grouped together with any other sibling entry frames bound to the same layout grid rectangle and specifying this value.
+
+These entry frames are positioned after each other in the direction of the layout path of their common immediately superior grid frame. The order in which they are positioned in the direction of the layout path is the same as their sequential layout order.
+
+Additionally, the entry frames in the group are positioned as close as possible to each other, and are centered, as a group, within the area available for placement of the group. This available area is calculated within the area between the leading edge of the last entry frame with normal order and the trailing edge of the first entry frame with reverse order, which are both bound to the same layout grid rectangle if present.
+
+In the two typical cases, this value of the sub-parameter specifies placement of the entry frames in the group as follows:
+
+- i) If the group is such that:
+  - no entry frame in the group is involved in any of those instances of reference line alignment such that the associated reference line is orthogonal to the layout path;
+  - the values of the sub-sub-parameter "trailing offset" specified for the entry frames in the group do not affect their placement except for the first entry frame;
+
+- the values of the sub-sub-parameter “leading offset” specified for the entry frames in the group do not affect their placement except for the last entry frame,
+
+then those entry frames shall be positioned so that:
+
+- for any two adjacent entry frames in the group, their distance apart shall be equal to the greater of the values of the sub-sub-parameter “centre separation” specified for the two entry frames;
+- their position shall be equidistant from the two positions at which they would be located if they were positioned as far as possible in the direction of, and in the direction opposite to, the layout path (see Figure 13).
+
+ii) If the group is composed of one entry frame such that:
+
+- the entry frame is involved in an instance of reference line alignment such that the associated reference line is orthogonal to the layout path;
+- any entry frame in the alignment group associated with this instance of reference line alignment is the only entry frame to be positioned in centre order within the layout grid rectangle to which it is bound,
+
+then the position of the entry frame shall be equidistant from the two positions at which it would be located if it was positioned as far as possible in the direction of, and in the direction opposite to, the layout path, particularly subject to the constraint by the reference line alignment (see Figure 14).
+
+For more complicated cases, refer to 13.7.
+
+If the parameter “variable position” does not specify a value for this sub-parameter, then the value ‘normal order’ is assumed.
+
+#### 12.1.10.6 Case 3
+
+In this case, the value ‘centre order’ of the sub-parameter “fill order” shall be treated as equivalent to the value ‘normal order’. Hence, an entry frame with centre order and another entry frame with normal order are regarded as having the same fill order.
+
+Zero or more of the sub-parameters “offset”, “separation”, “alignment” and “fill order” are specified as follow:
+
+##### a) *offset*
+
+The definition for this sub-parameter is the same as that described in 9.4.1.1 of ITU-T Rec. T.412 | ISO/IEC 8613-2.
+
+##### b) *separation*
+
+This sub-parameter specifies minimum amounts of separation between this entry frame and the nearest adjacent entry frame bound to no layout grid rectangle within the same immediately superior grid frame. The sub-parameter is structured into three sub-sub-parameters: “leading edge”, “trailing edge”, “centre separation”.
+
+The sub-sub-parameter “leading edge” specifies the minimum separation from the leading edge of the entry frame and the trailing edge of the next entry frame bound to no layout grid rectangle and having the same fill order.
+
+The sub-sub-parameter “trailing edge” specifies the minimum separation from the trailing edge of the entry frame and the leading edge of the immediately preceding entry frame bound to no layout grid rectangle and having the same fill order.
+
+Thus, a constraint on the separation of two adjacent entry frames which both have the same fill order, and are bound to no layout grid rectangle, is that the separation shall be equal to, or greater than, the greater of the value of “leading edge” for the first of the frames in the direction of layout path and the value of “trailing edge” for the second of the frames.
+
+The sub-sub-parameter “centre separation” specifies the minimum separation between two entry frames with different fill orders, and which are both bound to no layout grid rectangle.
+
+Thus, a constraint on the separation of two adjacent frames which have different fill orders, and are bound to no layout grid rectangle, is that the separation shall be equal to, or greater than, the greater of the values of “centre separation” specified for the two entry frames.
+
+For each edge, the sub-sub-parameter specifies the amount of separation for that edge in scaled measurement units (for the names of edges, refer to 9.1.9 of this Specification and 7.3.3 of ITU-T Rec. T.412 | ISO/IEC 8613-2).
+
+If the parameter “variable position” does not specify a value for this sub-parameter, or for any of its sub-sub-parameters, then the value zero is assumed for each sub-sub-parameter for which a value is not specified.
+
+##### c) *alignment*
+
+The definition for this sub-parameter is the same as that described in 9.4.1.1 of ITU-T Rec. T.412 | ISO/IEC 8613-2.
+
+##### d) *fill order*
+
+Although this sub-parameter takes one of three values, ‘normal order’, ‘centre order’, ‘reverse order’, the values ‘normal order’ and ‘centre order’ are treated as equivalent.
+
+Subject to satisfying constraints on placement specified by:
+
+- the sub-parameters “offset”, “separation” applied to an entry frame;
+- the attribute “border” applied to the grid frame immediately superior to the entry frame,
+
+the values of fill order are defined as follows:
+
+- 1) If the value is one of ‘normal order’ or ‘centre order’ then this entry frame is grouped together with any other sibling entry frames bound to no layout grid rectangle and specifying one of these values.
+
+These entry frames are positioned after each other in the direction of the layout path of their common immediately superior grid frame. The entry frames in the group are positioned in their sequential layout order, starting at the distance specified by the trailing offset of the first of these entry frames from the trailing edge of the immediately superior grid frame.
+
+- 2) If the value is ‘reverse order’ then this entry frame is grouped together with any other sibling entry frames bound to no layout grid rectangle and specifying this value.
+
+These entry frames are positioned after each other in the direction of the layout path of their common immediately superior grid frame. The entry frames in the group are positioned in their sequential layout order, ending at the distance specified by the leading offset of the last of these frames from the leading edge of the immediately superior grid frame.
+
+If the parameter “variable position” does not specify a value for this sub-parameter, then the value ‘normal order’ is assumed.
+
+
+
+### **12.1.11 Reference line alignment – major; Reference line alignment – minor**
+
+#### **Constituents:**
+
+Frame class descriptions.
+
+#### **Classification:**
+
+Non-mandatory.
+
+#### **Structure:**
+
+Consists of the two optional parameters: “aligned with” and “reference line”.
+
+#### **Permissible values:**
+
+- “aligned with”: either an empty sequence or a sequence of one or more layout object class identifiers;
+- “reference line”: a line segment characteristic.
+
+##### **Definition:**
+
+NOTE – In this definition, the scope of the symbol / is the entire text (see 5.2).
+
+**12.1.11.1** The layout process shall take the attribute “reference line alignment – major / minor” into account only when specified in an object class description such that:
+
+- the object class description is referred to in construction expressions from other object class descriptions of the grid frame type;
+- the object class description specifies the attribute “position” with the parameter “variable position”.
+
+Otherwise, the layout process shall ignore any specification for this attribute.
+
+This attribute specifies one or more groups of entry frames, each of which is called an *alignment group*, and specifies also that all the entry frames belonging to each alignment group shall be aligned along the reference line associated with the alignment group.
+
+In addition to the reference line, the following are associated with each alignment group:
+
+- a pair of minor / major layout grid lines;
+- one of ‘right-hand aligned’, ‘centred’ or ‘left-hand aligned’, if the layout path of the immediately superior grid frame is parallel to, or opposite to, its major / minor path; this set of values is the same as the set of values that are permissible for the sub-parameter “alignment” of the parameter “variable position” of the attribute “position”;
+- one of ‘normal order’, ‘centre order’ or ‘reverse order’, if the layout path of the immediately superior grid frame orthogonally traverses its major / minor path; this set of values is the same as the set of values that are permissible for the sub-parameter “fill order” of the parameter “variable position” of the attribute “position”.
+
+#### **12.1.11.2 Determination of quasi alignment groups**
+
+The parameter “aligned with” specifies one or more *quasi alignment groups*, and then alignment groups.
+
+A quasi alignment group is also associated with the three items listed in 12.1.11.1: a reference line, a pair of minor / major layout grid lines and one of ‘right-hand aligned’, ‘centred’, ‘left-hand aligned’, ‘normal order’, ‘centre order’ or ‘reverse order’. A quasi alignment group is specified in accordance with the following three constraints (see Figure 15):
+
+- a) All entry frames in a quasi alignment group shall satisfy the following necessary conditions:
+  - they are immediately subordinate to the common grid frame;
+  - they are bound to layout grid rectangles commonly edged with a pair of minor / major layout grid lines; this pair of layout grid lines is the pair of layout grid lines associated with this quasi alignment group;
+  - if the layout path of the immediately superior grid frame is parallel to, or opposite to, its major / minor path, they specify the same value for the sub-parameter “alignment”; this value is the value associated with the quasi alignment group;
+  - if the layout path of the immediately superior grid frame orthogonally traverses its major / minor path, they specify the same value for the sub-parameter “fill order”; this value is the value associated with this quasi alignment group.
+
+- b) If two entry frames satisfy one of the following conditions in addition to these necessary conditions, then both of them belong to the common quasi alignment group concerned:
+- the class description for one of those entry frames specifies this attribute, and the parameter “aligned with” in the value of this attribute specifies the frame class of the other entry frame;
+  - they are both of the same frame class, and the class description specifies this attribute.
+- c) A quasi alignment group is as small as possible: no proper subset of entry frames can be removed from it without violating one of the constraints a) and b).
+
+![Diagram of a 3x3 grid of entry frames illustrating quasi alignment groups. The grid is divided into three columns and three rows. The top row contains frames B1, A1, and A3. The middle row contains B2, C1, and A4. The bottom row contains B3, D1, and A6. Frame B3 is shaded with diagonal lines. Frame A2 is shaded with diagonal lines and is located below D1. A vertical arrow on the left points downwards, labeled 'Layout path'. A horizontal arrow at the bottom points to the right, labeled 'Major path'. A legend at the bottom shows a solid rectangle and a rectangle with diagonal lines, both labeled 'Quasi alignment groups'. The text 'TISO5180-95/d15' is at the bottom right.](255efa1d461fc79b4ed367aaec11637f_img.jpg)
+
+Frame class A: “fill order” = ‘normal order’  
+ “reference line alignment – major”:  
+ “aligned with” = Frame class B
+
+Frame class B: “fill order” = ‘normal order’
+
+TISO5180-95/d15
+
+Major path
+
+Quasi alignment groups
+
+Diagram of a 3x3 grid of entry frames illustrating quasi alignment groups. The grid is divided into three columns and three rows. The top row contains frames B1, A1, and A3. The middle row contains B2, C1, and A4. The bottom row contains B3, D1, and A6. Frame B3 is shaded with diagonal lines. Frame A2 is shaded with diagonal lines and is located below D1. A vertical arrow on the left points downwards, labeled 'Layout path'. A horizontal arrow at the bottom points to the right, labeled 'Major path'. A legend at the bottom shows a solid rectangle and a rectangle with diagonal lines, both labeled 'Quasi alignment groups'. The text 'TISO5180-95/d15' is at the bottom right.
+
+Figure 15 – Quasi alignment groups
+
+#### 12.1.11.3 Determination of alignment groups
+
+If the major / minor path is in the direction of the layout path within the immediately superior grid frame, an arbitrary quasi alignment group determined according to 12.1.11.2 is an alignment group.
+
+If the major / minor path is in the direction orthogonal to the layout path, a quasi alignment group is subdivided into one or more alignment groups as follows (see Figure 16):
+
+- a) entry frames in the quasi alignment group are indexed; the order is the same as the sequential layout order of those entry frames such that they are all in this quasi alignment group, and are bound to the same layout grid rectangle;
+- b) among all entry frames in this quasi alignment group, the entry frames provided with the same index are collected, and compose a single alignment group.
+
+![Diagram illustrating alignment groups in a grid layout. The grid is divided into four quadrants by a vertical 'Major path' and a horizontal 'Layout path'. Entry frames are labeled B1, A1, A3, B2, C1, A4, A5, D1, B3, A2, and A6. Index values are shown on the right: Index = 1 for the top and bottom rows, Index = 2 for the middle row. Alignment groups are indicated by different fill patterns: solid white, cross-hatch, solid grey, and diagonal lines. A legend at the bottom shows these four patterns under the heading 'Alignment groups'. The text 'TISO5190-95/d16' is in the bottom right corner of the grid area.](7d929ba1b7d09ea8e00b9e7abbbe50c9_img.jpg)
+
+Frame class A: "fill order" = 'normal order'  
+ "reference line alignment – major":  
+ "aligned with" = Frame class B
+
+Frame class B: "fill order" = 'normal order'
+
+Layout path
+
+Major path
+
+Index = 1
+
+Index = 2
+
+Index = 3
+
+Index = 1
+
+TISO5190-95/d16
+
+Alignment groups
+
+Diagram illustrating alignment groups in a grid layout. The grid is divided into four quadrants by a vertical 'Major path' and a horizontal 'Layout path'. Entry frames are labeled B1, A1, A3, B2, C1, A4, A5, D1, B3, A2, and A6. Index values are shown on the right: Index = 1 for the top and bottom rows, Index = 2 for the middle row. Alignment groups are indicated by different fill patterns: solid white, cross-hatch, solid grey, and diagonal lines. A legend at the bottom shows these four patterns under the heading 'Alignment groups'. The text 'TISO5190-95/d16' is in the bottom right corner of the grid area.
+
+Figure 16 – Alignment groups
+
+Hence, if two or more entry frames in a quasi alignment group are bound to a single layout grid rectangle, then, for each of such layout grid rectangles:
+
+- the first of those entry frames in the sequential layout order is provided with the index 1;
+- the second of those entry frames in the sequential layout order is provided with the index 2, and so on.
+
+Then:
+
+- the entry frames in this quasi alignment group with the index 1 compose the first alignment group;
+- the entry frames in this quasi alignment group with the index 2 compose the second alignment group, and so on.
+
+#### 12.1.11.4 Placement of an entry frame relative to the reference line
+
+All entry frames in a single alignment group share the same reference line. The reference line runs parallel to the direction of the major / minor path of the immediately superior grid frame.
+
+Every entry frame has an alignment point associated with it. This attribute, together with the attribute "indent – major / minor" if present, specifies the distance of the alignment point of each entry frame in the alignment group, from the reference line associated with the alignment group.
+
+The distance of the alignment point from the reference line is determined as follows:
+
+- the entry frame is positioned so that the distance of its alignment point from the reference line is the value specified by the attribute "indent – major / minor" applied to the entry frame (see 12.1.7);
+- if the attribute "indent – major / minor" does not apply to the entry frame, then the entry frame is positioned so that its alignment point shall be located on the reference line.
+
+#### 12.1.11.5 Placement of the reference line
+
+The position of the reference line is determined so that each entry frame in the alignment group shall be located within the grid rectangle to which it is bound, without violating constraints imposed by:
+
+- the attribute “grid gutters” applied to the immediately superior grid frame (see 12.1.3);
+- the sub-parameters “offset”, “separation”, “alignment” and “fill order” applied to the entry frame (see 12.1.10).
+
+NOTE – By definition, an entry frame is to be variably positioned within the immediately superior grid frame. Therefore, the value of the attribute “position” in the frame class description for the entry frame specifies zero or more of the four sub-parameters “offset”, “separation”, “alignment” and “fill order”.
+
+If an alignment group consists of a single entry frame, the placement of the entry frame according to this attribute shall coincide with the placement without taking this attribute into consideration.
+
+#### 12.1.11.6 Presentation of reference lines
+
+If the optional parameter “reference line” is specified for this attribute, the reference line associated with each alignment group shall be imaged within the immediately superior grid frame as follows (see Figure 17):
+
+- the reference line shall be imaged only within those grid rectangles to which some entry frame in the alignment group is bound;
+- the reference line may be imaged even within the grid gutter space;
+- the line segment characteristics specified for this parameter shall be used in imaging the reference line.
+
+If the layout process evaluates this parameter, it shall add one or more entries to the attribute “supplementary lines” specified in the object description for the immediately superior grid frame so that the imaging process shall be able to image the reference lines as specified by this parameter (see 12.1.12).
+
+| Parliament |      |      |
+|------------|------|------|
+| 55.6       | 50.3 | 56.7 |
+| 36.8       | 40.3 | 46.3 |
+| 31.6       | 56.5 | 43.5 |
+| 61.1       | 50.6 | 45.6 |
+| 52.6       | 34.5 | 49.6 |
+
+T03.drw
+
+Figure 17 – Presentation of reference lines
+
+**12.1.11.7** If the attribute does not specify a value for the parameter “aligned with”, then an empty sequence is assumed.
+
+If the attribute does not specify a value for the parameter “reference line”, the default line segment characteristic with the following parameters is assumed.
+
+For the parameters “line width” and “line type”:
+
+- “line width”: 0;
+- “line type”: ‘solid’.
+
+For the parameter “line colour”:
+
+- “colour expression”:
+  - “colour access mode”: ‘direct’;
+  - “colour space id”: 0;
+  - “colour specification”: 1, 1, 1;
+  - “colour tolerance”:
+    - “unspecified tolerance”: ‘infinite’.
+
+NOTE – The default value for a colour expression is a white colour in RGB space without limit on tolerance.
+
+### 12.1.12 Supplementary lines
+
+#### Constituents:
+
+Grid frame component descriptions.
+
+#### Classification:
+
+Non-mandatory for object class descriptions.
+
+Defaultable for object descriptions.
+
+#### **Structure:**
+
+A sequence of zero or more entries, each of which includes three parameters: “start”, “end”, “imaging factors”. The parameters “start” and “end” are mandatory, while the parameter “imaging factors” is optional.
+
+Each of the parameters “start” and “end” includes two mandatory parameters: “major coordinate” and “minor coordinate”.
+
+#### **Permissible values:**
+
+For the parameters “start” and “end”:
+
+- “major coordinate”: any integer (SMU);
+- “minor coordinate”: any integer (SMU).
+
+For the parameter “imaging factors”: a line segment characteristic.
+
+#### **Default value:**
+
+An empty sequence.
+
+#### **Definition:**
+
+**12.1.12.1** The imaging process shall take this attribute into account only when the relevant object description specifies the attribute “grid interval dimensions” (see 12.1.4).
+
+This attribute specifies zero or more lines to be imaged within the relevant grid frame to which the attribute is applied.
+
+The imaging process shall image zero or more layout grid lines in accordance with the attributes “grid lines” and “grid interval dimensions” applied to the grid frame. It shall image other supplementary lines, such as reference lines, in accordance with this attribute.
+
+**12.1.12.2** Each entry specified for this attribute corresponds to a single line to be imaged within the relevant grid frame.
+
+The parameter “start” specifies the position of one of the extremal points of the line. The parameter “end” specifies the position of the other extremal points of the line. For each, the sub-parameter “major / minor coordinate” specifies the distance of the extremal point from the grid reference point (see 9.1.11) of the grid frame in the direction of the major / minor path. The distance is measured in scaled measurement units.
+
+The imaging process shall image the line between the start and the end extremal points using the line segment characteristic specified for the parameter “imaging factors”. The line segment characteristic specifies its line width, line type and line colour (see 11.10).
+
+If an entry of this attribute does not specify a value for the parameter “imaging factors”, the default line segment characteristic with the following parameters is assumed.
+
+For the parameters “line width” and “line type”:
+
+- “line width”: 0;
+- “line type”: ‘solid’
+
+For the parameter “line colour”:
+
+- “colour expression”:
+  - “colour access mode”: ‘direct’;
+  - “colour space id”: 0;
+  - “colour specification”: 1, 1, 1;
+  - “colour tolerance”:
+    - “unspecified tolerance”: ‘infinite’.
+
+#### **NOTES**
+
+1 The default value for a colour expression is a white colour in RGB space without limit on tolerance.
+
+2 Although the positions of the extremal points of a supplementary line are specified by the parameters named “start” and “end”, the line does not have any direction. Exchanging the values of these parameters would not affect the imaging process at all.
+
+## 12.2 Layout directive attributes
+
+### 12.2.1 Block alignment point
+
+#### Constituents:
+
+May be specified for layout styles.
+
+Applicable only to basic logical component descriptions.
+
+#### Classification:
+
+Non-mandatory.
+
+#### Structure:
+
+One of the parameters: “content dependent”, “fixed position”, “variable position”.
+
+The parameter “fixed position” is structured into two optional sub-parameters: “vertical position”, “horizontal position”.
+
+The parameter “variable position” is structured into two optional sub-parameters: “vertical alignment”, “horizontal alignment”.
+
+#### Permissible values:
+
+For the parameter “content dependent”: ‘applies’.
+
+For the parameter “fixed position”:
+
+- “vertical position”: any integer (SMU);
+- “horizontal position”: any integer (SMU).
+
+For the parameter “variable position”:
+
+- “vertical alignment”: ‘top’, ‘centre’, ‘bottom’;
+- “horizontal alignment”: ‘left’, ‘centre’, ‘right’.
+
+#### Definition:
+
+**12.2.1.1** The layout process shall take this attribute into account only when the relevant basic logical object to which this attribute applies is subordinate to some grid logical object.
+
+This attribute specifies the position of the alignment point associated with each block which accommodates at least part of the content associated with the relevant basic object.
+
+**12.2.1.2** If the attribute specifies the parameter “content dependent”, then the content layout process shall determine the positions of the alignment points. The content layout process shall calculate these positions in accordance with the presentation attribute “alignment point” (see 12.3.1.1, 12.3.2.1 and 12.3.3.1) specified for the content portions associated with the relevant basic logical object.
+
+**12.2.1.3** If the attribute specifies the parameter “fixed position”, then the sub-parameter “vertical position / horizontal position” specifies the vertical / horizontal distance of each alignment point from the reference point of the block with which the alignment point is to be associated. This distance is measured in scaled measurement units.
+
+The vertical position is measured in the top-to-bottom direction:
+
+- if the sub-parameter “vertical position” specifies a positive / negative value, the alignment point shall be located beneath / above the reference point.
+
+The horizontal position is measured in the left-to-right direction:
+
+- if the sub-parameter “horizontal position” specifies a positive / negative value, the alignment point shall be located on the right / left of the reference point.
+
+An alignment point specified by the parameter “fixed position” may fall outside the relevant block.
+
+If this parameter does not specify a value for any of its sub-parameters, then the value zero is assumed for each sub-parameter for which a value is not specified.
+
+**12.2.1.4** If the attribute specifies the parameter “variable position”, then the sub-parameter “vertical / horizontal alignment” specifies the vertical / horizontal position of each alignment point.
+
+- If the sub-parameter “vertical alignment” specifies the value ‘top’ / ‘bottom’, then the alignment point shall be located on the top / bottom edge of the block with which the alignment point is associated.
+
+If the sub-parameter specifies the value ‘centre’, then the alignment point shall be located equidistant from the top and bottom edges of the block.
+
+- If the sub-parameter “horizontal alignment” specifies the value ‘left’ / ‘right’, then the alignment point shall be located on the left / right edge of the block.
+
+If the sub-parameter specifies the value ‘centre’, then the alignment point shall be located equidistant from the right and left edges of the block.
+
+NOTE – The left / right edge of the block may be different from its left-hand / right-hand edge. The former is defined absolutely, while the latter is defined relative to the layout path (see 7.3.3 of ITU-T Rec. T.412 | ISO/IEC 8613-2).
+
+An alignment point specified by the parameter “variable position” is always located within the relevant block.
+
+If this parameter does not specify a value for any of its sub-parameters, then the value ‘centre’ is assumed for each sub-parameter for which a value is not specified.
+
+**12.2.1.5** The attribute “concatenation” may specify that content for more than one basic logical object shall be concatenated within a single block (see 9.7.3 of ITU-T Rec. T.412 | ISO/IEC 8613-2).
+
+If the attribute “block alignment point” is applied to one of those basic logical objects, and is not applied to the others, then the alignment point associated with the block concerned shall be determined in accordance with this unique instance of the attribute.
+
+If this attribute is applied to more than one of those basic logical objects, then the alignment point shall be determined in accordance with the instance of this attribute applied to the last of such basic logical objects in the processing order.
+
+### 12.2.2 Grid description
+
+#### Constituents:
+
+May be specified for layout styles.
+
+Applicable only to grid logical component descriptions.
+
+#### Classification:
+
+Non-mandatory when specified for layout styles.
+
+Non-mandatory when applied to object class descriptions.
+
+Defaultable when applied to object descriptions.
+
+#### Structure:
+
+Consists of three optional parameters: “major size”, “minor size”, “entry-location association”.
+
+The parameter “entry-location association” is a list of entries, each of which is a pair of optional sub-parameters: “locations”, “entries”.
+
+#### Permissible values:
+
+For the parameters “major size” and “minor size”: a positive integer.
+
+For the parameter “entry-location association”:
+
+- “locations”: two logical coordinate pairs, the second one optional; each logical coordinate in such a pair is either a non-negative integer or the special value ‘last’;
+- “entries”: one or more sequences of non-negative integers.
+
+#### Default value:
+
+Each of the parameters is independently defaultable.
+
+For the parameters “major size” and “minor size”: 1.
+
+Each of the sub-parameters of the parameter “entry-location association” is further independently defaultable.
+
+For the sub-parameters:
+
+- “locations”: (0, 0), (‘last’, ‘last’);
+- “entries”: the same value as that of the attribute “subordinate” which is specified for the relevant grid logical object description.
+
+#### **Definition:**
+
+**12.2.2.1** The layout process shall take this attribute into account only when the attribute “grid frame classes” applies to the relevant grid logical object to which this attribute applies.
+
+This attribute specifies the following:
+
+- the major and minor sizes of a logical grid;
+- the association of subordinate logical objects with logical grid rectangles within the relevant logical grid.
+
+**12.2.2.2** The parameter “major / minor size” specifies the major / minor size of the logical grid associated with the relevant grid logical object to which the attribute applies.
+
+The major / minor size of the logical grid is the largest ordinal number assigned to major / minor logical grid lines within the logical grid (see 8.1.4).
+
+**12.2.2.3** The parameter “entry-location association” specifies a list of entries. Each entry specifies the association of one or more logical objects subordinate to the relevant grid logical object, with a single grid rectangle within the logical grid associated with the grid logical object.
+
+- The sub-parameter “locations” in the entry specifies the logical coordinate pairs for two diagonally opposite vertices of the grid rectangle to be specified.
+
+If the second logical coordinate pair is left out in this sub-parameter, the grid rectangle that this sub-parameter specifies shall be the single logical grid location such that the sub-parameter specifies its vertex with the smallest major and minor coordinates. Hence, if the sub-parameter specifies one coordinate pair  $(i, j)$ , the specified logical grid rectangle has the vertices whose logical coordinates are  $(i, j)$ ,  $(i + 1, j)$ ,  $(i + 1, j + 1)$ , and  $(i, j + 1)$ .
+
+- The sub-parameter “entries” specifies one or more sequences.
+
+Each sequence is composed of one or more non-negative integers, and specifies an individual logical object subordinate to the grid logical object: the object identifier of the subordinate logical object is that of the grid logical object followed by this sequence.
+
+This sub-parameter specifies the same number of subordinate logical objects as the number of the sequences specified for this sub-parameter.
+
+For each entry, one or more subordinate objects that the sub-parameter “entry” specifies are defined to be associated with the grid rectangle within the relevant logical grid that the sub-parameter “locations” specifies.
+
+These subordinate logical objects are called *entry objects*. An entry object may or may not be immediately subordinate to the relevant logical object.
+
+If an entry of this attribute does not specify a value for any of the sub-parameters, the following is assumed for each sub-parameter for which a value is not specified:
+
+- “locations”: (0, 0), (‘last’, ‘last’);
+- “entries”: the same value as that of the attribute “subordinate” which is specified for the relevant grid logical object description.
+
+**12.2.2.4** This attribute further specifies that the content associated with every entry object, which is specified by the sub-parameter “entries” specified for the parameter “entry-location association” of the attribute “grid description” that applies to the relevant logical object, shall be laid out within frames such that:
+
+- the frames are immediately subordinate to a grid frame referred to by the relevant grid logical object by means of the attribute “grid frame classes” (see 9.2);
+- the frames are variably positioned within the available area inside the layout counterpart (see 9.3.1) of the logical grid rectangle with which the entry object is associated.
+
+### 12.2.3 Grid frame classes
+
+#### Constituents:
+
+May be specified for layout styles.
+
+Applicable only to grid logical component descriptions.
+
+#### Classification:
+
+Non-mandatory when specified for layout styles.
+
+Non-mandatory when applied to component descriptions.
+
+#### **Permissible values:**
+
+Construction expressions.
+
+#### **Definition:**
+
+**12.2.3.1** This attribute specifies a sequence of one or more grid frames within the specific layout structure concerned, and further specifies that the content associated with the relevant grid logical object to which this attribute applies is to be laid out within these grid frames.
+
+**12.2.3.2** The sequence of grid frames is such that:
+
+- their sequential order is the same as the sequential layout order;
+- if a sequence is formed consisting of the values of the attribute “object class” for all grid frames in this sequence in their sequential layout order, then this sequence shall be a result of evaluation of the construction expression specified for this attribute.
+
+**12.2.3.3** The content associated with an arbitrary basic logical object subordinate to the grid logical object and every reproduction of that content shall be laid out within the grid frames specified for this attribute. Furthermore, no other part of content of the document shall be laid out within those grid frames.
+
+### **12.2.4 Obligatory same layout objects**
+
+#### **Constituents:**
+
+May be specified for layout styles.
+
+Applicable to all logical component descriptions except the document logical root.
+
+#### **Classification:**
+
+Non-mandatory.
+
+#### **Structure:**
+
+Consists of two parameters: “logical objects”, “layout objects”.
+
+#### **Permissible values:**
+
+For the parameter “logical objects”: one or more logical class identifiers.
+
+For the parameter “layout objects”: one or more layout class identifiers.
+
+#### **Definition:**
+
+**12.2.4.1** The parameter “logical objects” identifies zero or more logical objects within the specific logical structure concerned. These logical objects are called *target objects*, while the logical object to which this attribute applies is called the *relevant object*. This attribute also specifies that the content associated with an arbitrary basic logical object subordinate to the relevant object and every reproduction of that content shall be laid out within those layout objects specified by the parameter “layout objects”. Furthermore, each of those layout objects shall contain either:
+
+- the entire content associated with the target objects; or
+- the entire content of a single reproduction bundle in accordance with this attribute applied to the relevant object.
+
+A reproduction bundle is a set composed of a reproduction of the content associated with every target object (see 10.1.3).
+
+When the entire content associated with the relevant object can not be laid out within a single layout object that satisfies the constraints stated above, this attribute also specifies that the content associated with the target objects may be duplicated.
+
+The generated reproduction bundle should be laid out within a single layout object specified by the parameter “layout objects”. Then, the remaining content of the relevant object should be laid out within this same layout object.
+
+**12.2.4.2** The parameter “logical objects” specifies one or more logical object classes. From these logical object classes, the layout process shall generate a list composed of zero or more target objects.
+
+For each logical object class specified for the parameter “logical objects”, at most one target object shall be identified and added to the list. The target object to be identified is the nearest preceding object of the relevant object in the sequential logical order such that:
+
+- the target object shall be of the current logical object class;
+- the target object shall not be superior to the relevant object.
+
+If such a target object does not exist for the current logical object class, nothing shall be added to the list.
+
+NOTE – This is different from the case of the attribute selective same layout objects (see 12.2.6). Here, a target object is a preceding object of the relevant object instead of a following object.
+
+If no target object is identified for any logical object class specified for the parameter “logical objects”, this attribute never affects the layout.
+
+**12.2.4.3** The content associated with the relevant object shall be laid out within one or more layout objects each of which satisfies the following conditions:
+
+- a) the layout object shall be of one of the layout object classes specified for the parameter “layout objects”;
+- b) the layout object shall contain either:
+  - the entire content associated with the target objects; or
+  - the entire content of a single reproduction bundle generated in accordance with this attribute applied to the relevant object (see 10.1.3).
+
+If the content associated with a basic logical object subordinate to the relevant object is duplicated (see 10), the reproduction of this content shall be also laid out within one or more layout objects each of which satisfies these constraints a) and b).
+
+The layout process may duplicate the content associated with the target objects, in order to generate layout that satisfies the constraints a) and b).
+
+The duplication of content may occur only when the layout process is laying out the content associated with a basic logical object subordinate to the relevant object, and it has already laid out the entire content associated with the target objects. Under these conditions, the layout process may duplicate the entire content associated with the target objects in one of the following situations:
+
+- c) there is no layout object that satisfies the constraints a) and b);
+- d) within every layout object that satisfies the constraints a) and b), there is no area available for placement of the content associated with the basic logical object concerned.
+
+### 12.2.5 Presentation precedence
+
+#### Constituents:
+
+May be specified for layout styles.
+
+Applicable to grid logical component descriptions.
+
+#### Classification:
+
+Non-mandatory when specified for layout styles.
+
+Non-mandatory when applied to object class descriptions.
+
+Defaultable when applied to object descriptions.
+
+#### Permissible values:
+
+Either ‘major’ or ‘minor’.
+
+#### Default value:
+
+‘minor’.
+
+#### Definition:
+
+**12.2.5.1** The layout process shall take this attribute into account only when the attribute “grid frame classes” applies to the relevant grid logical object to which this attribute applies. Otherwise, the layout process shall ignore any specification for this attribute.
+
+This attribute specifies the order in which the layout process shall lay out the basic logical objects subordinate to the relevant grid logical object.
+
+**12.2.5.2** For each basic logical object subordinate to the relevant grid logical object, its *major index* and *minor index* are defined in accordance with the parameter “entry-location association” of the attribute “grid description” applied to the relevant grid logical object.
+
+- The major index of the basic logical object is the smallest major logical coordinate of a vertex of the grid rectangle *associated with* this basic logical object. The grid rectangle associated with the basic logical object is the intersection of all the grid rectangles associated with entry objects such that:
+  - a) they are superior to, or equal to, the basic logical object;
+  - b) their association with the grid rectangles is specified by the parameter “entry-location association” of the attribute “grid description” applied to the relevant logical object.
+
+If the basic logical object is neither an entry object nor subordinate to any entry objects satisfying the above conditions a) and b), its major index is defined as  $-\infty$ .
+
+- The minor index of the basic logical object is the smallest minor logical coordinate of a vertex of the grid rectangle associated with the basic logical object.
+
+If the basic logical object is neither an entry object nor subordinate to any entry objects satisfying the above conditions a) and b), its minor index is defined as  $-\infty$ .
+
+**12.2.5.3** The attribute “presentation precedence”, together with these major and minor indices, specifies the order in which the layout process shall lay out those basic logical objects subordinate to the relevant grid logical object. This order is called the *processing order of basic logical objects*.
+
+If the attribute specifies ‘major’ / ‘minor’, the relative position in the processing order of two basic logical objects is determined as follows (see Figure 18):
+
+- a) the basic logical object associated with the smaller minor / major index is defined to be preceding the other in the processing order;
+- b) if both of the basic logical objects are associated with the same minor / major index, the one associated with the smaller major / minor index is defined to be preceding the other in the processing order;
+- c) if both basic logical objects are associated with the same major and minor indices, the layout process takes account of the major and minor indices assigned to them in accordance with another instance of the attribute “presentation precedence” which applies to another grid logical object;
+- d) if the above three rules a) to c) cannot determine the processing order of the two objects, the order shall be the same as their sequential logical order.
+
+If two or more instances of this attribute affect the processing order of common two basic logical objects, their effects on the order shall be compatible with each other (see 13.5).
+
+![Figure 18: Processing order of basic logical objects. The diagram shows two scenarios: 'major' and 'minor' presentation precedence. Each scenario includes a 'Specific logical structure' tree, a 'Grid logical object' tree, and a 'Logical grid' diagram. The 'major' scenario shows a processing order that follows the major path of the grid (top to bottom, left to right). The 'minor' scenario shows a processing order that follows the minor path of the grid (left to right, top to bottom).](649d03e4c5c42598e91826f372146f65_img.jpg)
+
+Specific logical structure
+
+Grid logical object
+
+Minor path
+
+Major path
+
+Logical grid
+
+Presentation precedence = 'major'
+
+Specific logical structure
+
+Grid logical object
+
+Minor path
+
+Major path
+
+Logical grid
+
+Presentation precedence = 'minor'
+
+● Basic logical object
+
+→ Processing order
+
+ISO5200-95/d17
+
+Figure 18: Processing order of basic logical objects. The diagram shows two scenarios: 'major' and 'minor' presentation precedence. Each scenario includes a 'Specific logical structure' tree, a 'Grid logical object' tree, and a 'Logical grid' diagram. The 'major' scenario shows a processing order that follows the major path of the grid (top to bottom, left to right). The 'minor' scenario shows a processing order that follows the minor path of the grid (left to right, top to bottom).
+
+Figure 18 – Processing order of basic logical objects
+
+### 12.2.6 Selective same layout objects
+
+#### Constituents:
+
+May be specified for layout styles.
+
+Applicable to all logical component descriptions except the document logical root.
+
+#### Classification:
+
+Non-mandatory.
+
+#### Structure:
+
+Consists of two parameters: “logical objects”, “layout objects”.
+
+#### Permissible values:
+
+For the parameter “logical objects”: one or more logical class identifiers.
+
+For the parameter “layout objects”: one or more layout class identifiers.
+
+#### **Definition:**
+
+**12.2.6.1** First, the parameter “logical objects” identifies zero or more logical objects within the specific logical structure concerned. These logical objects are called *target objects*, while the logical object to which this attribute applies is called the *relevant object*. Thereafter, this attribute specifies that the end of the content associated with the relevant object and every reproduction of the end of this content shall be laid out within those layout objects specified by the parameter “layout objects”. Furthermore, each of those layout objects shall contain at least either:
+
+- a fragment of the content associated with some target object; or
+- a reproduction of a fragment of the content associated with some target object (see 10.1).
+
+**12.2.6.2** The parameter “logical objects” specifies one or more logical object classes. From these logical object classes, the layout process shall generate a list composed of zero or more target objects.
+
+For each logical object class specified for the parameter “logical objects”, at most one target object shall be identified and added to the list. The target object to be identified is the next logical object of the relevant object in the sequential logical order such that:
+
+- it is not subordinate to the relevant object;
+- it is of the current object class.
+
+Such a target object may not exist for the current logical object class. If not, nothing shall be added to the list.
+
+NOTE – This is different from the case of the attribute “obligatory same layout objects” (see 12.2.4). Here, a target object is a following object of the relevant object instead of a preceding object.
+
+If no target object is identified for any logical object class specified for the parameter “logical objects”, this attribute shall never affect the layout.
+
+**12.2.6.3** The *tail object* of the relevant object denotes the basic logical object whose position is the last in the processing order (see 12.2.5) among all the basic logical objects subordinate to the relevant object.
+
+This attribute specifies that the end of the content associated with this tail object shall be laid out within a layout object which satisfies the following conditions:
+
+- a) the layout object shall be of one of the layout object classes specified for the parameter “layout objects”;
+- b) there shall exist at least one target object such that the layout object contains at least either:
+  - a fragment of the content associated with this target object; or
+  - a fragment of a reproduction of the content associated with a basic logical object subordinate to the target object.
+
+If the content associated with the tail object is duplicated, this attribute also specifies that the end of the reproduction of this content shall be laid out within a layout object which satisfies these constraints a) and b).
+
+### **12.2.7 Supplementary line directive**
+
+#### **Constituents:**
+
+May be specified for layout styles.
+
+Applicable to grid logical component descriptions.
+
+#### **Classification:**
+
+Non-mandatory when specified for layout styles.
+
+Non-mandatory when applied to component descriptions.
+
+#### **Structure:**
+
+A sequence of zero or more entries, each of which includes three parameters: “start”, “end”, “imaging factors”.
+
+The parameters “start” and “end” are mandatory, while the parameter “imaging factors” is optional.
+
+#### **Permissible values:**
+
+For the parameters “start” and “end”: a logical coordinate pair.
+
+For the parameter “imaging factors”: a line segment characteristic.
+
+#### **Definition:**
+
+**12.2.7.1** The layout process shall take this attribute into account only when applied to a grid logical object to which the attribute “grid frame classes” applies.
+
+This attribute specifies zero or more lines to be imaged within every grid frame referred to by the relevant grid logical object by means of the attribute “grid frame classes” (see 12.2.3).
+
+**12.2.7.2** For each entry specified for this attribute, and for each grid frame referred to by the relevant logical object, this entry specifies a single line to be imaged within this grid frame.
+
+The parameters included in this entry further specifies the positions of the two extremal points and the imaging factors (i.e. line width, line type and line colour) of this line.
+
+**12.2.7.3** The parameter “start” specifies the position of one of the extremal points of the line within each grid frame. The parameter “end” specifies the position of the other extremal point of the line.
+
+The logical coordinate pair  $(i, j)$  specified for this parameter specifies that the extremal point shall be placed at the point at which the  $i$ -th major layout grid line and the  $j$ -th minor layout grid line of the layout grid intersect each other.
+
+Taking the attribute “grid interval dimension” applied to the relevant grid frame into account, the layout process shall calculate the actual position of each extremal point, which is a pair of the distances from the grid reference point (see 9.1.11) in the directions of the major and minor paths, in scaled measurement units.
+
+The layout process shall further generate a new entry composed of the parameters “start”, “end” and “imaging factors”. Values shall be assigned to these parameters as follows:
+
+- For the sub-parameter “major / minor coordinate” of the parameter “start” – The calculated distance of the start extremal point from the grid reference point in the direction of the major / minor path.
+- For the sub-parameter “major / minor coordinate” of the parameter “end” – The calculated distance of the end extremal point from the grid reference point in the direction of the major / minor path.
+- For the parameter “imaging factors” – The same value as that assigned to the “imaging factors” specified for the relevant entry of this attribute.
+
+If the relevant entry does not specify a value for this parameter, the default line segment characteristic with the following parameters is assumed:
+
+For the parameters “line width” and “line type”:
+
+- “line width”: 0;
+- “line type”: ‘solid’.
+
+For the parameter “line colour”:
+
+- “colour expression”:
+  - “colour access mode”: ‘direct’;
+  - “colour space id”: 0;
+  - “colour specification”: 1, 1, 1;
+  - “colour tolerance”:
+    - “unspecified tolerance”: ‘infinite’.
+
+NOTE – The default value for a colour expression is a white colour in RGB space without limit on tolerance.
+
+This generated entry shall be a part of the value of the attribute “supplementary lines” specified in the object description of the relevant grid frame (see 12.1.12).
+
+**12.2.7.4** The imaging process shall image the line between the start and the end extremal points using the line segment characteristic specified for the parameter “imaging factors”. The line segment characteristic specifies its line width, line type and line colour.
+
+NOTE – Although the positions of the extremal points of a supplementary line are specified by the parameters named “start” and “end”, the line does not have any direction. Exchanging the values of these parameters would not affect the imaging process at all.
+
+## 12.3 Presentation attributes
+
+This subclause defines three attributes that are used to instruct the content layout process to calculate the position of alignment points associated with blocks. Those attributes are commonly named “alignment point”, and each of them is applicable to one of the content architectures: the character content architecture, the raster graphics content architecture and the geometric graphics content architecture.
+
+### 12.3.1 Character content architecture
+
+#### 12.3.1.1 Alignment point
+
+##### Category:
+
+Shared.
+
+##### Structure:
+
+Consists of two optional parameters: “position in character path”, “position in line progression”.
+
+##### Permissible values:
+
+For the parameter “position in character path”: graphic characters from the set of graphic elements specified by the presentation attributes “graphic character sets” and “graphic character subrepertoire”, or one of the special values ‘start’, ‘end’, or ‘centre’.
+
+For the parameter “position in line progression”: a positive integer, or one of the special values ‘top’, ‘bottom’, ‘centre’, ‘top-baseline’, ‘bottom-baseline’, ‘top-middle-baseline’ and ‘bottom-middle-baseline’.
+
+##### Default value:
+
+For the parameter “position in character path”: ‘centre’.
+
+For the parameter “position in line progression”: ‘centre’.
+
+##### Definition:
+
+**12.3.1.1.1** This attribute specifies the position of the alignment point within a basic layout object. According to the value specified for the attribute, the content layout process shall calculate the position of the alignment point, and shall export the position to the document layout process.
+
+**12.3.1.1.2** The parameter “position in character path” specifies the position of the alignment point in the direction of the character path:
+
+- If the parameter specifies the value ‘start’, the alignment point shall be on the start edge of the positioning area.
+- If the parameter specifies the value ‘end’, the alignment point shall be on the end edge of the positioning area.
+- If the parameter specified the value ‘centre’, the alignment point shall be equidistant from the start and end edges.
+- If the parameter specifies a group of characters, the alignment point shall be at the same position as the position point of the first character images of the first instance of this group of characters in the string positioned in the positioning area. If the specified group of characters does not appear in the string, then the position of the alignment point defaults to the centre of the positioning area.
+
+**12.3.1.1.3** The parameter “position in line progression” specifies the position of the alignment point in the direction of the line progression:
+
+- If the parameter specifies the value ‘top’, the alignment point shall be on the top edge of the positioning area.
+- If the parameter specifies the value ‘bottom’, the alignment point shall be on the bottom edge of the positioning area.
+- If the parameter specified the value ‘centre’, the alignment point shall be equidistant from the top and bottom edges.
+- If the parameter specifies the value ‘top-baseline’, the alignment point shall locate on the baseline nearest to the top edge of the positioning area.
+- If the parameter specifies the value ‘bottom-baseline’, the alignment point shall locate on the baseline nearest to the bottom edge of the positioning area.
+- If the parameter specifies the value ‘top-middle-baseline’ or ‘bottom-middle-baseline’, the position of the alignment point depends on the number of the baselines.
+
+If the block includes an odd number of baselines, the alignment point shall be located on the uniquely determined middle baseline.
+
+If the block includes an even number of baselines, there are two middle baselines. If the value of the parameter is ‘top-middle-baseline’ / ‘bottom-middle-baseline’, then the alignment point shall be located on the middle baseline which is closer to the top / bottom edge.
+
+- If the parameter specifies a positive integer  $i$ , the alignment point shall locate on the  $i$ -th baseline. If  $i$  exceeds the total number of lines, the alignment point shall locate on the last baseline.
+
+NOTE – The positions of alignment points in the character content architecture are illustrated in Figure 19.
+
+![Figure 19: Alignment points in the character content architecture. The diagram illustrates a 'Basic layout object' represented by a large rectangle containing a 'Positioning area'. The rectangle has labeled edges: 'Top edge', 'Bottom edge', 'Start edge' (left), and 'End edge' (right). Eight specific points are marked with 'x' and coordinates: (s,t) at top-left, (e,t) at top-right, (s,c) at middle-left, (e,c) at middle-right, (s,b) at bottom-left, (c,b) at bottom-center, and (e,b) at bottom-right. A central point (c,c) is also marked. Arrows indicate 'Line progression' (downward) and 'Character path' (rightward). Below this is a legend: c (centre), s (start), e (end), t (top), b (bottom). A secondary smaller diagram shows a box with the number '3,141592' intersected by a horizontal 'Baseline' and a vertical dashed line indicating an 'Alignment point' at the comma. Text below specifies: 'position in character path' = ',' and 'position in line progression' = 'top-baseline'.](9cb54072e43a6b6717eb16036a7640a2_img.jpg)
+
+Basic layout object
+
+Positioning area
+
+Top edge
+
+Start edge
+
+Line progression
+
+Character path
+
+End edge
+
+Bottom edge
+
+c (centre), s (start), e (end), t (top), b (bottom)
+
+3,141592 Baseline
+
+Alignment point
+
+“position in character path” = ‘,’
+
+“position in line progression” = ‘top-baseline’
+
+TISO5210-95/d18
+
+Figure 19: Alignment points in the character content architecture. The diagram illustrates a 'Basic layout object' represented by a large rectangle containing a 'Positioning area'. The rectangle has labeled edges: 'Top edge', 'Bottom edge', 'Start edge' (left), and 'End edge' (right). Eight specific points are marked with 'x' and coordinates: (s,t) at top-left, (e,t) at top-right, (s,c) at middle-left, (e,c) at middle-right, (s,b) at bottom-left, (c,b) at bottom-center, and (e,b) at bottom-right. A central point (c,c) is also marked. Arrows indicate 'Line progression' (downward) and 'Character path' (rightward). Below this is a legend: c (centre), s (start), e (end), t (top), b (bottom). A secondary smaller diagram shows a box with the number '3,141592' intersected by a horizontal 'Baseline' and a vertical dashed line indicating an 'Alignment point' at the comma. Text below specifies: 'position in character path' = ',' and 'position in line progression' = 'top-baseline'.
+
+Figure 19 – Alignment points in the character content architecture
+
+### 12.3.2 Raster graphics content architecture
+
+#### 12.3.2.1 Alignment point
+
+##### Category:
+
+Shared.
+
+##### Structure:
+
+Two parameters: “position in pel path”, “position in line progression”.
+
+##### Permissible values:
+
+For the parameter “position in pel path”: ‘start’, ‘end’, ‘centre’.
+
+For the parameter “position in line progression”: ‘top’, ‘bottom’, ‘centre’.
+
+##### Default value:
+
+For the parameter “position in pel path”: ‘centre’.
+
+For the parameter “position in line progression”: ‘centre’.
+
+##### Definition:
+
+**12.3.2.1.1** This attribute specifies the position of the alignment point within a basic layout object. According to the value specified for the attribute, the content layout process shall calculate the position of the alignment point, and shall export the position to the document layout process.
+
+**12.3.2.1.2** The parameter “position in pel path” specifies the position of the alignment point in the direction of the pel path:
+
+- If the parameter specifies the value ‘start’, the alignment point shall be on the start edge of the rectangular area where the clipped pel array is positioned. The start and end edges of the area are defined such that the direction from the start edge to the end edge is in the direction of the pel path.
+- If the parameter specifies the value ‘end’, the alignment point shall be on the end edge of the area where the clipped pel array is positioned.
+- If the parameter specified the value ‘centre’, the alignment point shall be equidistant from the start and end edges.
+
+**12.3.2.1.3** The parameter “position in line progression” specifies the position of the alignment point in the direction of the line progression:
+
+- If the parameter specifies the value ‘top’, the alignment point shall be on the top edge of the rectangular area where the clipped pel array is positioned. The top and bottom edges of the area are defined such that the direction from the top edge to the bottom edge is in the direction of the line progression.
+- If the parameter specifies the value ‘bottom’, the alignment point shall be on the bottom edge of the area where the clipped pel array is positioned.
+- If the parameter specified the value ‘centre’, the alignment point shall be equidistant from the top and bottom edges.
+
+NOTE – The positions of alignment points in the raster graphics content architecture are illustrated in Figure 20.
+
+### **12.3.3 Geometric graphics content architecture**
+
+#### **12.3.3.1 Alignment point**
+
+##### **Category:**
+
+Shared.
+
+##### **Structure:**
+
+Two parameters: “position in x-axis”, “position in y-axis”.
+
+##### **Permissible values:**
+
+For the parameter “position in x-axis”: ‘start’, ‘end’, ‘centre’.
+
+For the parameter “position in y-axis”: ‘top’, ‘bottom’, ‘centre’.
+
+**Default value:**
+
+For the parameter “position in x-axis”: ‘centre’.
+
+For the parameter “position in y-axis”: ‘centre’.
+
+**Definition:**
+
+![Diagram of a basic layout object showing alignment points and line progression.](e5ded249943a879ef58cae5b6b87c576_img.jpg)
+
+The diagram illustrates a 'Basic layout object' as a rectangular frame. Inside, a grid of circles represents the layout. A 'Pel path' is indicated by a horizontal arrow pointing to the right. 'Line progression' is indicated by a vertical arrow pointing downwards. Alignment points are marked with 'x' symbols at the corners and center of the grid: (s,t) at top-left, (c,t) at top-center, (e,t) at top-right, (s,c) at middle-left, (c,c) at center, (e,c) at middle-right, (s,b) at bottom-left, (c,b) at bottom-center, and (e,b) at bottom-right. A legend below the diagram defines the letters: c (centre), s (start), e (end), t (top), b (bottom). The text 'TISO5220-95/d19' is located at the bottom right of the diagram area.
+
+Diagram of a basic layout object showing alignment points and line progression.
+
+**Figure 20 – Alignment points in the raster graphics content architecture**
+
+**12.3.3.1.1** This attribute specifies the position of the alignment point within a basic layout object. According to the value specified for the attribute, the content layout process shall calculate the position of the alignment point, and shall export the position to the document layout process.
+
+**12.3.3.1.2** The parameter “position in x-axis” specifies the position of the alignment point in the direction of the x-axis:
+
+- If the parameter specifies the value ‘start’, the alignment point shall be on the start edge of the basic layout object within which the region of interest has been laid out. The start edge is defined as the edge which has the lowest x-coordinate of the two edges orthogonal to the x-axis.
+- If the parameter specifies the value ‘end’, the alignment point shall be on the end edge of the basic layout object. The end edge is defined as the edge which has the highest x-coordinate of the two edges orthogonal to the x-axis.
+- If the parameter specifies the value ‘centre’, the alignment point shall be equidistant from the start and end edges.
+
+**12.3.3.1.3** The parameter “position in y-axis” specifies the position of the alignment point in the direction of the y-axis.
+
+- If the parameter specifies the value ‘top’, the alignment point shall be on the top edge of the basic layout object. The top edge is defined as the edge which has the highest y-coordinate of the two edges orthogonal to the y-axis.
+- If the parameter specifies the value ‘bottom’, the alignment point shall be on the bottom edge of the basic layout object. The bottom edge is defined as the edge which has the lowest y-coordinate of the two edges orthogonal to the y-axis.
+- If the parameter specifies the value ‘centre’, the alignment point shall be equidistant from the top and bottom edges.
+
+## **13 Reference model of the document layout process with respect to tabular layout**
+
+This clause provides a description of the document layout process as applicable to documents which contain a specific logical structure, a complete generic layout structure and optionally layout styles, presentation styles, and/or a generic logical structure.
+
+This Specification introduces the following additional functions to the document layout process described in ITU-T Rec. T.412 | ISO/IEC 8613-2:
+
+- layout of reproductions of content;
+- a layout reference of a grid logical object to grid frames;
+- determination of the dimensions of a layout grid;
+
+- determination of the imaging factors of table lines.
+
+Additionally, this Specification modifies some functions of the document layout process described in ITU-T Rec. T.412 | ISO/IEC 8613-2 in the following areas:
+
+- processing order of basic logical objects;
+- placement of entry frames within a grid frame.
+
+### 13.1 Layout of reproductions of content
+
+Duplication of content shall occur only in accordance with the layout directive attribute “obligatory same layout objects” (see 12.2.4). The logical object to which this attribute applies is called a relevant object. The sub-parameter “logical objects” of this attribute specifies zero or more logical objects, called target objects.
+
+When the layout process commences to lay out the content associated with the relevant object, its content shall be laid out as far as possible within a single layout object. This layout object shall be of one of the layout object classes specified by the parameter “layout objects” of the attribute “obligatory same layout objects” applied to the relevant object, and shall contain the entire content associated with each of the target objects.
+
+If no such layout object exists, a reproduction of the content associated with each target object may be generated. The entire content of these generated reproductions is laid out within a single layout object of one of the layout object classes specified by the parameter “layout objects”. Then, the content associated with the relevant object is laid out as far as possible within this layout object.
+
+If the area within this layout object available for the content of the relevant object is consumed completely, the content associated with each target object may be duplicated. The entire content of these generated reproductions is laid out within a single layout object of one of the layout object classes specified by the parameter “layout objects”. Then, the layout process continues to lay out the remaining content of the relevant object.
+
+This step shall be repeated until all of the content associated with the relevant object has been laid out subject to the constraints imposed by this attribute.
+
+The relevant object may be a target object of the attribute “obligatory same layout objects” that applies to a different logical object. In such cases, the content of the relevant object may be duplicated. The generated reproduction is also subject to the attribute “obligatory same layout objects” that applies to the relevant object with which the source content portions of the reproduction are associated. Hence, the reproduction shall be laid out in accordance with the same rules as apply to the content associated with the relevant object.
+
+### 13.2 Layout reference from a grid logical object to grid frames
+
+When the layout process reaches an active grid logical object, one or more grid frames are identified within the specific layout structure under construction. These grid frames are said to *be referenced* by the grid logical object (see 9.2).
+
+The layout process shall identify those referenced grid frames in accordance with:
+
+- the attribute “grid frame classes” applied to the grid logical object;
+- the construction expressions specified in the generic layout structure concerned.
+
+The layout process also generates a layout grid within each of the referenced grid frames, whose major and minor sizes are equal to those of the logical grid associated with the grid logical object.
+
+The attribute “grid frame classes” further specifies that the content associated with the grid logical object shall be entirely laid out within these referenced grid frames, and that other parts of the document shall be excluded from any of those referenced grid frames.
+
+In addition, the attribute “grid description” applied to the same grid logical object constrains layout of the content associated with any of those entry objects whose association with their logical grid rectangles are specified by the parameter “entry-location association” of this attribute: the content shall be laid out within frames each of which is such that:
+
+- it is immediately subordinate to one of the referenced grid frames;
+- it is placed within the layout counterpart of the logical grid rectangle with which the entry object is associated (see 8.2).
+
+### 13.3 Determination of the dimensions of layout grids
+
+#### 13.3.1 Constraints on the dimensions of layout grids
+
+The dimensions of a layout grid within a grid frame are subject to the following constraints.
+
+##### 13.3.1.1 Dimensions and border allowance of the grid frame
+
+The layout grid shall be entirely within the grid frame. Furthermore, the layout grid shall not fall within the border free space of the grid frame.
+
+The dimensions and border allowance of the grid frame are specified by the attributes “dimensions” and “border” applied to the grid frame (see also 9.4.1.2 and 9.4.1.3 of ITU-T Rec. T.412 | ISO/IEC 8613-2).
+
+##### 13.3.1.2 Grid dimensions
+
+The attribute “grid dimensions” applied to the grid frame specifies either specific dimensions or a rule to determine the dimensions of the layout grid (see 12.1.2).
+
+The attribute is structured into two parameters “major dimension” and “minor dimension” which specify the dimension of the layout grid in the direction of the major and minor path respectively.
+
+Each parameter includes one of the sub-parameters “fixed dimension”, “expansive dimension” and “rule B”:
+
+- if the parameter specifies the sub-parameter “fixed dimension”, the dimension of the grid shall be the specified value;
+- if the parameter specifies the sub-parameter “expansive dimension”, the dimension shall be the dimension of the area available for placement of the layout grid within the grid frame;
+- if the parameter specifies the sub-parameter “rule B”, the parameter specifies no particular constraints.
+
+##### 13.3.1.3 Grid interval dimensions
+
+The attribute “grid interval dimensions” applied to the grid frame specifies either specific dimensions or a rule to determine the dimensions of the grid intervals of the layout grid (see 12.1.4).
+
+To each grid interval dimension, one of the sub-parameters “fixed dimension”, “proportional” and “rule B” is applied:
+
+- if the parameter specifies the sub-parameter “fixed dimension”, the grid interval dimension concerned shall be the specified value;
+- if the parameter specifies the sub-parameter “proportional”, the ratio of the grid interval dimension to other specified grid interval dimensions shall have the specified value;
+- if the parameter specifies the sub-parameter “rule B”, the parameter specifies no particular constraints on the grid interval dimension.
+
+#### 13.3.2 Minimal layout of the layout grid
+
+The document layout process determines all the grid interval dimensions of a layout grid so that the determination shall provide a *minimal layout* of the layout grid.
+
+Determination of the grid interval dimensions of a layout grid provides a *minimal layout*, if and only if, for an arbitrary subset of the grid intervals of the layout grid, their determined dimensions cannot be decreased without increasing the determined dimensions for other grid intervals or violating the constraints described in 13.3.1.
+
+In general, there may be two or more instances of minimal layout of the layout grid. The layout process is merely constrained to select an arbitrary instance of minimal layout for each layout grid.
+
+Based on the instance of minimal layout that the layout process selects, the layout process assigns values to the parameters of the attribute “grid interval dimensions” specified in the grid frame description corresponding to the relevant grid frame. The specified values are:
+
+- for the parameter “major / minor interval dimensions”, a grid construction expression of the grid sequence construction type composed of interval indicators such that the *i*-th interval indicator has the value of the parameter “fixed dimension” associated with the value of the dimension of the *i*-th major / minor grid interval.
+
+### 13.4 Determination of the imaging factors of table lines
+
+A *grid line segment* is a segment of a layout grid line delimited by two consecutively numbered layout grid lines intersecting that layout grid line at right angles.
+
+The layout process determines the line segment characteristic to be applied to each grid line segment in accordance with the attribute “grid lines” specified by the grid frame class description.
+
+Evaluation of a grid line expression specified for the parameters of the attribute may produce a set of line segment characteristics. Each line segment characteristic applies to an individual grid line segment (see 11.7). This line segment characteristic indicates the imaging factors (the line width, line type and line colour) applicable to the grid line segment (see 11.10).
+
+If the grid line segment is within the interior of some grid rectangle to which one or more entry frames are bound, the line segment characteristic shall be modified so as to specify the invisible line type.
+
+If at least one line segment characteristic derived from the attribute “grid lines” specified in the class description is modified, the layout process assigns values to the attribute “grid lines” specified in the object description corresponding to the relevant grid frame, so that the modification is reflected:
+
+- For the parameter “major / minor grid lines”, a grid line expression of the grid sequence construction type consisting of line characteristics is specified.  
+The value of the parameter “expression” of the  $i$ -th line segment characteristic expression involved is of the grid sequence construction type consisting of line segment characteristics such that the  $j$ -th line segment characteristic indicates the imaging factors of the  $j$ -th line segment of the  $i$ -th major /minor grid line.
+
+If no line segment characteristic derived from evaluation of the attribute “grid lines” is modified, the layout process should assign the same values to this attribute in the object description as those specified for the attribute “grid lines” in the grid frame class description.
+
+### **13.5 Processing order of basic logical objects**
+
+If the relevant specific logical structure does not contain any grid logical objects to which the attribute “grid frame classes” applies, the order in which the layout process lays out the content associated with the basic logical objects of the specific logical structure is their sequential logical order (see 7.1.2 of ITU-T Rec. T.412 | ISO/IEC 8613-2).
+
+If the specific logical structure contains grid logical objects to which the attribute “grid frame classes” applies (called *active grid logical objects*), then the layout process shall determine the order in which it processes basic logical objects according to the values of the parameter “entry-location association” of the attribute “grid description” and the attribute “presentation precedence” which are both applied to those active grid logical objects. These values specified for each active grid logical object provide an independent constraint on the processing order of the basic logical objects subordinate to this grid logical object (see 12.2.5).
+
+Hence, if two or more active grid logical objects are superior to a single basic logical object, the values of the parameter “entry-location association” and the attribute “presentation precedence” applied to those active grid logical objects may impose contradictory constraints on the processing order around this basic logical object. The logical structure shall be designed so that such contradictory situations shall not occur.
+
+If all active grid logical objects satisfy the condition:
+
+- no other active grid logical objects shall be located between an active grid logical object and any of its entry objects, whose association with the grid rectangle is defined by the parameter “entry-location association” of the attribute “grid description” applied to that active grid logical object,
+
+their constraints on the processing order are always compatible. It is recommended that the specific logical structure be designed in this way.
+
+### **13.6 Placement of an entry frame not bound to a grid rectangle**
+
+An entry frame is, by definition, to be variably positioned. Hence, the value of the attribute “position” in the frame class description for the entry frame specifies the four sub-parameters “offset”, “separation”, “alignment” and “fill order”.
+
+If the entry frame is not bound to any grid rectangle, the entry frame shall be laid out within its immediately superior grid frame as described in 10.5.2 of ITU-T Rec. T.412 | ISO/IEC 8613-2, provided that the layout process takes account of only those entry frames which are not bound to any grid rectangle within their common immediately superior grid frame (see 12.1.10).
+
+The area available for placement of the entry frame is determined in accordance with:
+
+- the attribute “border” applied to the immediately superior grid frame;
+- the sub-parameter “offset” applied to the entry frame;
+
+- the sub-parameters “separation” and “fill order” applied to those entry frames which are not bound to any grid rectangles.
+
+The sub-sub-parameters “leading edge” and “trailing edge” of the sub-parameter “separation” constrain the distances between the leading edge and trailing edge of any two adjacent entry frames with the same fill order, neither of which is bound to any grid rectangles.
+
+The sub-sub-parameter “center separation” of the sub-parameter “separation” constrains the distances between the leading edge and trailing edge of the adjacent entry frames with different fill orders, neither of which is bound to any grid rectangles.
+
+The entry frame is positioned within this available area as specified by the sub-parameter “fill order”.
+
+### 13.7 Placement of an entry frame bound to a grid rectangle
+
+If an entry frame accommodates content associated with some entry object, then the entry frame shall be laid out within a particular layout grid rectangle. This entry frame is said to be *bound to* that layout grid rectangle. For placement of the entry frame, the following are carried out:
+
+- determine the area available for placement of the entry frame (see 13.7.1);
+- position the entry frame within the determined available area (see 13.7.2);
+- for each temporarily positioned entry frame, determine the area available for its placement (see 13.7.1 and 13.7.3);
+- position this temporarily positioned entry frame within the determined available area (see 13.7.2 and 13.7.3);
+- repeat the steps c) and d) until no temporarily positioned entry frame is left;
+- rectify the position of the entry frames with centre order which are involved in the above steps (see 13.7.4).
+
+#### 13.7.1 Determination of the area available for placement of entry frames
+
+The area available for placement of an entry frame is confined to the inside of the layout grid rectangle to which the entry frame is bound. Further, the following constrain the available area:
+
+- the attribute “grid gutters” applied to the immediately superior grid frame;
+- the sub-parameter “offset” applied to the entry frame;
+- the sub-parameters “separation” and “fill order” applied to those entry frames which are bound to the same grid rectangle.
+
+In addition, in calculating the available area, some entry frames may be *temporarily positioned*.
+
+##### 13.7.1.1 Constraints imposed by the attribute “grid gutters”
+
+The entry frame is constrained not to fall within the gutter spaces reserved around the edges of the grid rectangle to which the entry frame is bound.
+
+The gutter space widths are specified by the attribute “grid gutters” applied to the immediately superior grid frame (see 12.1.3).
+
+##### 13.7.1.2 Constraints imposed by the sub-parameter “offset”
+
+The entry frame shall be so positioned that the distance between the corresponding edge of the grid rectangle to which the entry frame is bound and the trailing, leading, left-hand and right-hand edges of the entry frame shall be no less than the minimum amounts specified respectively by the four sub-sub-parameters “trailing offset”, “leading offset”, “left-hand offset” and “right-hand offset” of the sub-parameter “offset”.
+
+##### 13.7.1.3 Constraints imposed by the sub-parameter “separation”
+
+The entry frame shall be so positioned that separation from the adjacent sibling entry frames which are also bound to the same grid rectangle shall be no less than the minimum amounts determined in accordance with the sub-parameter “separation” applied to the entry frame and its adjacent siblings. This sub-parameter is structured into three sub-sub-parameters: “leading edge”, “trailing edge” and “centre separation”.
+
+### 13.7.1.3.1 The sub-sub-parameters “leading edge” and “trailing edge”
+
+If the adjacent entry frame is placed earlier in the direction of the layout path within the same grid rectangle, and it is laid out in the same fill order, then the distance between the leading edge of this adjacent entry frame and the trailing edge of the relevant entry frame is constrained to be no less than the maximum of:
+
+- the value of the sub-sub-parameter “leading edge” applied to the adjacent entry frame;
+- the value of the sub-sub-parameter “trailing edge” applied to the entry frame concerned.
+
+If the adjacent entry frame is placed later in the direction of the layout path within the same grid rectangle, and it is laid out in the same fill order, then the distance between the trailing edge of this adjacent entry frame and the leading edge of the relevant entry frame is constrained to be no less than the maximum of:
+
+- the value of the sub-sub-parameter “trailing edge” applied to the adjacent entry frame;
+- the value of the sub-sub-parameter “leading edge” applied to the entry frame concerned.
+
+### 13.7.1.3.2 The sub-sub-parameter “centre separation”
+
+If the adjacent entry frame is laid out in a different fill order within the same grid rectangle, the pair of edges whose distance is to be constrained is one of the following:
+
+- a) the leading edge of the adjacent entry frame and the trailing edge of the relevant entry frame;
+- b) the trailing edge of the adjacent entry frame and the leading edge of the relevant entry frame.
+
+Case a) applies if any of the following applies:
+
+- the normal order applies to the adjacent entry frame, and the centre order applies to the relevant entry frame;
+- the normal order applies to the adjacent entry frame, the reverse order applies to the relevant entry frame, and no entry frame is laid out in centre order within the same grid rectangle;
+- the centre order applies to the adjacent entry frame, and the reverse order applies to the relevant entry frame.
+
+Case b) applies if any of the following applies:
+
+- the centre order applies to the adjacent entry frame, and the normal order applies to the relevant entry frame;
+- the reverse order applies to the adjacent entry frame, and the centre order applies to the relevant entry frame;
+- the reverse order applies to the adjacent entry frame, the normal order applies to the relevant entry frame, and no entry frame is laid out in centre order within the same grid rectangle.
+
+In both of cases a) and b), the distance between the edges is constrained to be no less than the maximum of:
+
+- the value of the sub-sub-parameter “centre separation” applied to the adjacent entry frame;
+- the value of the sub-sub-parameter “centre separation” applied to the entry frame concerned.
+
+### 13.7.1.4 Temporary positioning of entry frames
+
+In calculating the area available for placement of an entry frame, the layout process *temporarily positions* entry frames already laid out within the same grid rectangle. Then, the layout process determines the dimensions of the available area in accordance with the constraints described in 13.7.1.1 – 13.7.1.3.
+
+The layout process may re-calculate the available area for an entry frame which has already been laid out. This re-calculation occurs when the position of the entry frame is to be rectified because the entry frame is involved in some reference line alignment invoked by layout of another entry frame.
+
+Those entry frames which are to be temporarily positioned vary depending on the fill order that applies to the relevant entry frame.
+
+#### 13.7.1.4.1 Available area for an entry frame with normal order
+
+For the purpose of calculating the available area for an entry frame with normal order, all entry frames laid out in centre order are *temporarily positioned* as far as possible in the direction of the layout path, without violating the constraints described in 13.7.1.1 – 13.7.1.3.
+
+For the purpose of re-calculating the available area for an entry frame already laid out, all entry frames laid out in normal order subsequent to the entry frame concerned are further *temporarily positioned* as far as possible in the direction of the layout path, without violating the constraints described in 13.7.1.1 – 13.7.1.3.
+
+Then, the area available for placement is determined taking into account the constraints described in 13.7.1.1 – 13.7.1.3 (see Figure 21).
+
+#### 13.7.1.4.2 Available area for an entry frame with centre order
+
+For the purpose of calculating the available area for an entry frame with centre order, all entry frames laid out in centre order prior to the entry frame concerned are *temporarily positioned* as far as possible in the direction opposite to the layout path, without violating the constraints described in 13.7.1.1 – 13.7.1.3.
+
+For the purpose of re-calculating the available area for an entry frame already laid out, all entry frames laid out in centre order subsequent to the entry frame concerned are further *temporarily positioned* as far as possible in the direction of the layout path, without violating the constraints described in 13.7.1.1 – 13.7.1.3.
+
+Then, the area available for placement is determined taking into account the constraints described in 13.7.1.1 – 13.7.1.3 (see Figure 22).
+
+#### 13.7.1.4.3 Available area for an entry frame with reverse order
+
+For the purpose of calculating the available area for an entry frame with reverse order, all entry frames laid out in centre order and all entry frames laid out in reverse order prior to the entry frame concerned are *temporarily positioned* as far as possible in the direction opposite to the layout path, without violating the constraints described in 13.7.1.1 – 13.7.1.3.
+
+For the purpose of re-calculating the available area for an entry frame already laid out, all entry frames laid out in centre order and all entry frames laid out in reverse order prior to the entry frame concerned are *temporarily positioned* as far as possible in the direction opposite to the layout path, without violating any of the constraints described in 13.7.1.1 – 13.7.1.3.
+
+Then, the area available for placement is determined taking into account the constraints described in 13.7.1.1 – 13.7.1.3 (see Figure 23).
+
+#### 13.7.1.5 The following notations are used in Figures 21, 22 and 23:
+
+- $G_1$  Gutter width around gridline1
+- $G_2$  Gutter width around gridline2
+- $G_3$  Gutter width around gridline3
+- $G_4$  Gutter width around gridline4
+- $O_t$  Trailing offset of the relevant entry frame
+- $O_l$  Leading offset of the relevant entry frame
+- $O_{lh}$  Left-hand offset of the relevant entry frame
+- $O_{rh}$  Right-hand offset of the relevant entry frame
+- $S_t$  Trailing separation of the relevant entry frame
+- $S_l$  Leading edge separation of the relevant entry frame
+- $S_c$  Centre separation of the relevant entry frame
+- $O^{A,t}$  Trailing offset of frame A
+- $O^{A,l}$  Leading offset of frame A
+- $S^{A,t}$  Trailing edge separation of frame A
+- $S^{A,l}$  Leading edge separation of frame A
+- $S^{A,c}$  Centre separation of frame A
+- $H^A$  Height of frame A
+- $O^{B,t}$  Trailing offset of frame B
+- $O^{B,l}$  Leading offset of frame B
+- $S^{B,t}$  Trailing edge separation of frame B
+- $S^{B,l}$  Leading edge separation of frame B
+
+$S^{B,c}$  Centre separation of frame B
+
+$H^B$  Height of frame B
+
+$O^{C,t}$  Trailing offset of frame C
+
+$O^{C,l}$  Leading offset of frame C
+
+$S^{C,t}$  Trailing edge separation of frame C
+
+$S^{C,l}$  Leading edge separation of frame C
+
+$S^{C,c}$  Centre separation of frame C
+
+$H^C$  Height of frame C
+
+![Diagram illustrating the available area for an entry frame with normal order. The diagram shows a layout grid rectangle containing three frames: Frame A (normal), Frame B (centre), and Frame C (reverse). The available area is the shaded region between the frames. Dimensions d1 through d7 are indicated, representing the distances from the frames to the grid lines. A legend defines the layout grid line and layout grid rectangle.](bf316d14a760a28869460fd9b0c9f616_img.jpg)
+
+Layout path ↓
+
+Gridline4
+
+Gridline3
+
+Gridline1
+
+Gridline2
+
+Frame A (normal)
+
+Frame B (centre)
+
+Frame C (reverse)
+
+Available area
+
+d1
+
+d2
+
+d3
+
+d4
+
+d5
+
+d6
+
+d7
+
+..... Layout grid line
+
+□ Layout grid rectangle
+
+TSO5230-95/d20
+
+Diagram illustrating the available area for an entry frame with normal order. The diagram shows a layout grid rectangle containing three frames: Frame A (normal), Frame B (centre), and Frame C (reverse). The available area is the shaded region between the frames. Dimensions d1 through d7 are indicated, representing the distances from the frames to the grid lines. A legend defines the layout grid line and layout grid rectangle.
+
+$$d_1 = \max(O_t, G_1/2, d_5 + H^A + \max(S_t, S_t^A))$$
+
+$$d_2 = \max(O_l, G_2/2, d_6 + H^B + \max(S_c, S_c^B))$$
+
+$$d_3 = \max(O_{lh}, G_3/2)$$
+
+$$d_4 = \max(O_{rh}, G_4/2)$$
+
+$$d_5 = \max(O_t^A, G_1/2)$$
+
+$$d_6 = \max(O_l^B, G_2/2, d_7 + H^C + \max(S_c^B, S_c^C))$$
+
+$$d_7 = \max(O_l^C, G_2/2)$$
+
+Figure 21 – Available area for an entry frame with normal order
+
+![Diagram illustrating the available area for an entry frame with normal order. The diagram shows a layout grid with four vertical grid lines (Gridline1, Gridline2, Gridline3, Gridline4) and three horizontal grid lines (Gridline1, Gridline2, Gridline3). A central 'Available area' is defined by a hatched rectangle. Above it is 'Frame A (normal)' and below it is 'Frame B (centre)'. To the right of the available area is 'Frame C (reverse)'. Dimensions d1 through d7 are indicated by arrows. A 'Layout path' arrow points downwards on the left. A legend at the bottom shows a dashed line for 'Layout grid line' and a solid rectangle for 'Layout grid rectangle'.](e9f6a9e6beb9ae97b392bf38b93ad748_img.jpg)
+
+Layout path
+
+Gridline4
+
+Gridline3
+
+Gridline1
+
+Gridline2
+
+Frame A (normal)
+
+Frame B (centre)
+
+Available area
+
+Frame C (reverse)
+
+d1
+
+d2
+
+d3
+
+d4
+
+d5
+
+d6
+
+d7
+
+Layout grid line
+
+Layout grid rectangle
+
+TISO5240-95/d21
+
+Diagram illustrating the available area for an entry frame with normal order. The diagram shows a layout grid with four vertical grid lines (Gridline1, Gridline2, Gridline3, Gridline4) and three horizontal grid lines (Gridline1, Gridline2, Gridline3). A central 'Available area' is defined by a hatched rectangle. Above it is 'Frame A (normal)' and below it is 'Frame B (centre)'. To the right of the available area is 'Frame C (reverse)'. Dimensions d1 through d7 are indicated by arrows. A 'Layout path' arrow points downwards on the left. A legend at the bottom shows a dashed line for 'Layout grid line' and a solid rectangle for 'Layout grid rectangle'.
+
+$$d_1 = \max(O_t, G_1/2, d_6 + H^B + \max(S_t, S_t^B))$$
+
+$$d_2 = \max(O_l, G_2/2, d_7 + H^C + \max(S_c, S_c^C))$$
+
+$$d_3 = \max(O_{lh}, G_3/2)$$
+
+$$d_4 = \max(O_{rh}, G_4/2)$$
+
+$$d_5 = \max(O_t^A, G_1/2)$$
+
+$$d_6 = \max(O_t^B, G_1/2, d_5 + H^A + \max(S_c^A, S_c^B))$$
+
+$$d_7 = \max(O_l^C, G_2/2)$$
+
+Figure 22 – Available area for an entry frame with normal order
+
+![Diagram illustrating the available area for an entry frame with reverse order. The diagram shows a layout grid with four vertical gridlines (Gridline4, Gridline3, Gridline1, Gridline2) and a horizontal layout path. Three frames are shown: Frame A (normal), Frame B (centre), and Frame C (reverse). The available area is a shaded rectangle. Dimensions d1 through d7 are indicated. A legend shows a dashed line for 'Layout grid line' and a solid rectangle for 'Layout grid rectangle'.](dbfe5a97dc7e71fd9ae813d4bb865e29_img.jpg)
+
+Layout path
+
+Gridline4
+
+Gridline3
+
+Gridline1
+
+Gridline2
+
+Frame A (normal)
+
+Frame B (centre)
+
+Frame C (reverse)
+
+Available area
+
+d5
+
+d6
+
+d7
+
+d1
+
+d4
+
+d3
+
+d2
+
+Layout grid line
+
+Layout grid rectangle
+
+TISO5250-95/d22
+
+Diagram illustrating the available area for an entry frame with reverse order. The diagram shows a layout grid with four vertical gridlines (Gridline4, Gridline3, Gridline1, Gridline2) and a horizontal layout path. Three frames are shown: Frame A (normal), Frame B (centre), and Frame C (reverse). The available area is a shaded rectangle. Dimensions d1 through d7 are indicated. A legend shows a dashed line for 'Layout grid line' and a solid rectangle for 'Layout grid rectangle'.
+
+$$d_1 = \max(O_t, G_1/2, d_7 + H^C + \max(S_t^A, S_t^C))$$
+
+$$d_2 = \max(O_l, G_2/2)$$
+
+$$d_3 = \max(O_h, G_3/2)$$
+
+$$d_4 = \max(O_h, G_4/2)$$
+
+$$d_5 = \max(O_t^A, G_1/2)$$
+
+$$d_6 = \max(O_t^B, G_1/2, d_5 + H^A + \max(S_c^A, S_c^B))$$
+
+$$d_7 = \max(O_t^C, G_1/2, d_6 + H_B + \max(S_c^B, S_c^C))$$
+
+Figure 23 – Available area for an entry frame with reverse order
+
+### 13.7.2 Placement of an entry frame within its available area
+
+If the attribute “reference line alignment – major” or “reference line alignment – minor” is applied to some of the entry frames immediately subordinate to a grid frame, the attribute specifies zero or more groups, each of which is composed of two or more entry frames. These groups of entry frames are called *alignment groups*.
+
+Placement of an entry frame is carried out in one of the following ways: cases a) and b):
+
+- a) if the entry frame to be positioned is included in one of the alignment groups, the layout process positions this relevant entry frame and the other entry frames in this alignment group as a group (see 13.7.2.2);
+- b) if the entry frame is not included in any of the alignment groups, the layout process positions this relevant entry frame independent of any other entry frames (see 13.7.2.1).
+
+### 13.7.2.1 Placement of an independent entry frame
+
+An entry frame which is not involved in any instance of reference line alignment is positioned within its available area under the following constraints.
+
+#### 13.7.2.1.1 Layout path and fill order
+
+In positioning the entry frame in the direction of the layout path of the immediately superior grid frame, the layout process shall take account of the fill order of the entry frame and the layout path.
+
+The fill order, which is specified by the sub-parameter “fill order” applied to the entry frame, has one of the values ‘normal order’, ‘centre order’ and ‘reverse order’:
+
+- If the sub-parameter “fill order” specifies the value ‘normal order’, the entry frame is positioned within the available area as close as possible to the trailing edge of the available area.
+- If the sub-parameter “fill order” specifies ‘centre order’, the entry frame is positioned within the available area as close as possible to the trailing edge of the available area.  
+  
+This position of the entry frame is just temporary. The position of the entry frame, together with those of other entry frames laid out in centre order, shall subsequently be rectified as described in 13.7.4.
+- If the sub-parameter “fill order” specifies the value ‘reverse order’, the entry frame is positioned within the available area as close as possible to the leading edge of the available area.
+
+#### 13.7.2.1.2 Alignment
+
+In positioning the entry frame in the direction orthogonal to the layout path of the immediately superior grid frame, the layout process shall take account of the alignment type applied to the entry frame.
+
+The alignment type, which is specified by the sub-parameter “alignment” applied to the entry frame, has one of the values ‘left-hand aligned’, ‘centred’ and ‘right-hand aligned’:
+
+- if the sub-parameter “alignment” specifies the value ‘left-hand aligned’, the entry frame is positioned as close as possible to the left-hand edge of the available area;
+- if the sub-parameter “alignment” specifies the value ‘centred’, the entry frame is centred, in the direction orthogonal to the layout path, within the available area;
+- if the sub-parameter “alignment” specifies the value ‘right-hand aligned’, the entry frame is positioned as close as possible to the right-hand edge of the available area.
+
+### 13.7.2.2 Placement of entry frames in an alignment group
+
+If the entry frame to be positioned is included in some alignment group, the layout process positions all entry frames in this alignment group as a group. More precisely, the layout process aligns those entry frames along a single reference line.
+
+This reference line is parallel to either the major path or the minor path of the immediately superior grid frame. If the reference line alignment occurs in accordance with the attribute “reference line alignment – major / minor”, then the associated reference line runs parallel to the major / minor path.
+
+In positioning the entry frames in this alignment group, the layout process takes account of:
+
+- the attribute “frame alignment point” applied to the entry frames in the alignment group;
+- the attribute “indent – major” applied to the entry frames in the alignment group, if the reference line is parallel to the major path of the immediately superior grid frame;
+- the attribute “indent – minor” applied to the entry frames in the alignment group, if the reference line is parallel to the minor path of the immediately superior grid frame;
+- the sub-parameters “fill order” and “alignment of the parameter position” applied to the relevant entry frame.
+
+**13.7.2.2.1 Determination of alignment groups**
+
+At the first step of placement of an entry frame, which is involved in reference alignment, the layout process shall identify those alignment groups including the entry frame to be positioned (see 12.1.11). The entry frame is included in one or two alignment groups. Each alignment group is composed of two or more entry frames including the relevant entry frame, and if the entry frame is included in two alignment groups, then their associated reference lines are orthogonal to each other.
+
+Furthermore, the alignment group satisfies the following conditions (see 12.1.11):
+
+- Every entry frame in the alignment group shall be bound to a grid rectangle within the common immediately superior grid frame. Although different entry frames in the group may be bound to different grid rectangles, those grid rectangles shall be edged with two common layout grid lines parallel to their associated reference line.
+- If the reference line is parallel to the layout path of the immediately superior grid frame, the sub-parameter “alignment” applied to each entry frame in the group shall specify a common value.
+- If the reference line is orthogonal to the layout path of the immediately superior grid frame, the sub-parameter “fill order” applied to each entry frame in the group shall specify a common value.
+
+**13.7.2.2.2 Determination of available areas**
+
+At the second step, the layout process calculates the area available for placement of the entry frames in the alignment group.
+
+The available area for the relevant entry frame is calculated as described in 13.7.1.
+
+For the available area for each of the other entry frames in the alignment group:
+
+- if the reference line is orthogonal to the layout path of the immediately superior grid frame, the area is calculated as described in 13.7.1;
+- if the reference line is parallel to the layout path of the immediately superior grid frame, only the position of the entry frame in the direction orthogonal to the reference line is calculated; hence no entry frames are temporarily positioned during the calculation of the available area (see 13.7.1.4).
+
+**13.7.2.2.3 Placement of entry frames in the direction of the reference line**
+
+The position of the relevant entry frame in the direction of the reference line shall be determined in accordance with:
+
+- the sub-parameter “fill order” applied to this entry frame, if the reference line is parallel to the layout path, and if the entry frame is not involved in any other instance of reference line alignment (see 13.7.2.1.1);
+- the sub-parameter “alignment” applied to this entry frame, if the reference line is orthogonal to the layout path, and if the entry frame is not involved in any other instance of reference line alignment (see 13.7.2.1.2);
+- the rule described in 13.7.2.2.4, if the entry frame is involved in another instance of reference line alignment.
+
+The position of each of the other entry frames in the alignment group in the direction of the reference line remains unchanged.
+
+**13.7.2.2.4 Placement of entry frames in the direction orthogonal to the reference line**
+
+The positions of the entry frames in the direction orthogonal to the reference line shall be determined by the following two steps:
+
+- At the first step, the entry frames are positioned relative to the reference line.
+- At the second step, the reference line is positioned. There are two cases:
+  - the reference line is parallel to the layout path;
+  - the reference line is orthogonal to the layout path.
+
+**13.7.2.2.4.1 Placement of entry frames relative to the reference line**
+
+Entry frames which are to be aligned along a single reference line are first positioned relative to the reference line. In this step, the layout process shall take account of the alignment point and the indent applied to each entry frame.
+
+- The attribute “frame alignment point” applied to the entry frame specifies the position of the alignment point associated with the entry frame.
+
+- Either the attribute “indent – major” or “indent – minor” applied to the entry frame specifies the distance between the alignment point associated with the entry frame and the reference line.
+
+If the relevant instance of reference line alignment is in accordance with the attribute “reference line alignment – major / minor”, then the value of the attribute “indent – major / minor” specifies the amount of indent (see also Figure 12). If the attribute “indent – major / minor” does not apply to the entry frame, then the value zero is assumed for this attribute.
+
+Thus, the layout process evaluates the attributes “frame alignment point” and “indent – major / minor” applied to each entry frame involved in this instance of reference line alignment, and determines its position in the orthogonal direction viewed from the reference line concerned.
+
+#### 13.7.2.2.4.2 Placement of the reference line parallel to the layout path
+
+If the reference line is parallel to the layout path of the immediately superior grid frame, the layout process positions the reference line taking account of the sub-parameter “alignment” applied to the entry frames aligned along this reference line.
+
+NOTE – For every entry frame concerned, the sub-parameter “alignment” always specifies the same value (see 12.1.11).
+
+The value of the sub-parameter “alignment” is one of the values ‘left-hand aligned’, ‘centred’ and ‘right-hand aligned’.
+
+Irrespective of the value of the sub-parameter, the reference line shall be positioned so that every entry frame in this alignment group shall fall entirely within the area available for placement of the entry frame.
+
+Subject to this common constraint, the reference line is positioned as follows:
+
+- if the sub-parameter specifies the value ‘left-hand aligned’, the reference line is positioned as far as possible in the direction which traverses the layout path at right angles in an anticlockwise direction;
+- if the sub-parameter specifies the value ‘right-hand aligned’, the reference line is positioned as far as possible in the direction which traverses the layout path at right angles in a clockwise direction;
+- if the sub-parameter specifies the value ‘centred’, the reference line is positioned equidistant from the following two imaginary positions:
+  - the position at which the reference line would be placed, if the sub-parameter specified the value ‘left-hand aligned’;
+  - the position at which the reference line would be placed, if the sub-parameter specified the value ‘right-hand aligned’.
+
+#### 13.7.2.2.4.3 Placement of the reference line running orthogonal to the layout path
+
+If the reference line is orthogonal to the layout path of the immediately superior grid frame, the layout process positions the reference line taking account of the sub-parameter “fill order” applied to the entry frames aligned along this reference line.
+
+NOTE – For every entry frame concerned, the sub-parameter “fill order” specifies the same value (see 12.1.11).
+
+The value of the sub-parameter “fill order” is one of the values ‘normal order’, ‘centre order’ and ‘reverse order’.
+
+Irrespective of the value of the sub-parameter, the reference line shall be positioned so that every entry frame in this alignment group shall fall entirely within the area available for placement of the entry frame (see Figure 24).
+
+Subject to this common constraint, the reference line is to be positioned as follows:
+
+- If the sub-parameter specifies the value ‘normal order’, the reference line is positioned as far as possible in the direction opposite to the layout path.
+- If the sub-parameter specifies ‘centre order’, the reference line is positioned as far as possible in the direction opposite to the layout path.
+
+The position of the reference line determined in this step is just temporary. The position of the reference line, together with that of other entry frames laid out in centre order, shall subsequently be rectified as described 13.7.4.
+
+- If the sub-parameter specifies the value ‘reverse order’, the reference line is positioned as far as possible in the direction of the layout path.
+
+### 13.7.3 Placement of temporarily positioned entry frames
+
+When the layout process calculates the area available for placement of entry frames, it may also *temporarily position* them (see 13.7.1.4). The layout process repositions those temporarily positioned entry frames one by one, in accordance with the rules described in 13.7.
+
+![Figure 24 – Reference line alignment. The diagram consists of two parts. The top part shows a vertical layout path with four rectangular frames. The first frame is shaded and contains an 'X' alignment point. The second frame is unshaded. The third frame is shaded and contains an 'X' alignment point. The fourth frame is unshaded. The bottom part shows a horizontal layout path with three rectangular frames. The first frame is shaded and contains an 'X' alignment point. The second frame is unshaded. The third frame is shaded and contains an 'X' alignment point. A legend indicates that 'X' represents alignment points and shaded areas represent available areas. The text 'TISO5260-95/d23' is located at the bottom right of the diagram.](5509e6ec160899dd306e462bb6a3643b_img.jpg)
+
+TISO5260-95/d23
+
+'left-hand aligned' specified for reference line alignment in major path
+
+X Alignment points  
+ Available areas
+
+Figure 24 – Reference line alignment. The diagram consists of two parts. The top part shows a vertical layout path with four rectangular frames. The first frame is shaded and contains an 'X' alignment point. The second frame is unshaded. The third frame is shaded and contains an 'X' alignment point. The fourth frame is unshaded. The bottom part shows a horizontal layout path with three rectangular frames. The first frame is shaded and contains an 'X' alignment point. The second frame is unshaded. The third frame is shaded and contains an 'X' alignment point. A legend indicates that 'X' represents alignment points and shaded areas represent available areas. The text 'TISO5260-95/d23' is located at the bottom right of the diagram.
+
+**Figure 24 – Reference line alignment**
+
+For each entry frame that is temporarily positioned, the layout process modifies its position in the direction of the layout path, and leaves the position in the direction orthogonal to the layout path unchanged. Hence:
+
+- a) if that entry frame is not involved in any instance of reference line alignment such that the associated reference line is orthogonal to the layout path, the rule described in 13.7.2.1.1 applies to the placement; such a frame is called *independent*;
+- b) if that entry frame is involved in some instance of reference line alignment such that the associated reference line is orthogonal to the layout path, the rule described in 13.7.2.2.3 and 13.7.2.2.4 applies to the placement; such a frame is called *associated*.
+
+The fill orders of those temporarily positioned entry frames are dependent on the fill order of the initial entry frame that the layout process initially tries to lay out:
+
+- if the initial entry frame is positioned in normal order, the fill order of an arbitrary entry frame positioned temporarily is either normal or centre order;
+- if the initial entry frame is positioned in reverse order, the fill order of an arbitrary entry frame positioned temporarily is either reverse or centre order;
+- if the initial entry frame is positioned in centre order, the fill order of an arbitrary entry frame positioned temporarily is always centre order.
+
+The order in which the layout process repositions them varies depending on the values of fill order applied to them.
+
+- The layout process repositions an entry frame with normal / reverse order, if one of the following applies:
+  - a) the entry frame is of the independent type, and it is the first / last in the sequential layout order among those entry frames with normal / reverse order that are temporarily positioned within the layout grid rectangle to which the entry frame concerned is bound and that have not been repositioned yet;
+  - b) the entry frame is of the associated type, and each entry frame in the alignment group is the first / last in the sequential layout order among those entry frames with normal / reverse order that are temporarily positioned within the layout grid rectangle to which this entry frame is bound and that have not been repositioned yet.
+- If one or more entry frames with centre order are temporarily positioned, the layout process shall first reposition all entry frames positioned temporarily in normal or reverse order. Then the layout process repositions an entry frame with centre order, if one of the following applies:
+  - a) the entry frame is of the independent type, and it is the first in the sequential layout order among those entry frames with centre order that are temporarily positioned within the layout grid rectangle to which the entry frame concerned is bound and that have not been repositioned yet;
+  - b) the entry frame is of the associated type, and each entry frame in the alignment group is the first in the sequential layout order among those entry frames with centre order that are temporarily positioned within the layout grid rectangle to which this entry frame is bound and that have not been repositioned yet.
+
+#### 13.7.4 Rectification of position of entry frames with centre order
+
+If entry frames are to be positioned in centre order, and if their positions in the direction of the layout path are determined in accordance with 13.7.2.1.1 and 13.7.2.2.4.3, the positions still remain temporary. At the final step, the layout process shall rectify their positions in the direction of the layout path. The entry frames involved in this rectification are such that:
+
+- they are to be positioned in centre order;
+- their positions in the direction of the layout path are determined in accordance with 13.7.2.1.1 and 13.7.2.2.4.3.
+
+The following two steps are carried out:
+
+- a) the layout process packs those involved entry frames with centre order;
+- b) the layout process moves the involved entry frames as a group in the direction of the layout path.
+
+##### 13.7.4.1 Packing of entry frames
+
+The layout process classifies all the involved entry frames into two groups, which are respectively called the *movable* group and the *immovable* group. The movable and immovable groups shall satisfy the following:
+
+- the movable and immovable groups shall contain no common entry frame;
+- if two entry frames are included respectively in the movable and immovable group, and if they are positioned within the same grid rectangle, then the former entry frame shall precede the latter in the direction of the layout path;
+- there shall be at least one grid rectangle within which at least one entry frame belonging to the movable group and at least one entry frame belonging to the immovable group are positioned;
+- if an entry frame is of the associated type, then all entry frames in the associated alignment group shall be included in either the movable or immovable group to which that entry frame belongs.
+
+The layout process moves all the entry frames in this movable group by the same amount in the direction of the layout path. The distance moved shall be as large as possible, subject to the constraints imposed by:
+
+- the attribute “grid gutters” applied to the immediately superior grid frame;
+- the sub-parameters “offset” and “separation” applied to all the entry frames within the grid frame.
+
+The layout process repeats these procedures until there exists no movable group which can be moved by a positive amount.
+
+#### 13.7.4.2 Final placement of the entry frames
+
+After the involved entry frames are packed, the layout process finally moves all the involved entry frames by the same amount in the direction of the layout path.
+
+The distance moved is one half of the maximum possible, subject to the constraints imposed by:
+
+- the attribute “grid gutters” applied to the immediately superior grid frame;
+- the sub-parameters “offset” and “separation” applied to all the entry frames within the grid frame.
+
+### 14 Reference model of the document imaging process with respect to tabular layout
+
+This clause provides a description of the document imaging process as applicable to documents of the formatted document architecture class or the formatted processable document architecture class (see 6.3.13 of ITU-T Rec. T.412 | ISO/IEC 8613-2).
+
+Such documents include constituents representing a specific layout structure and may optionally include constituents representing a generic layout structure and/or presentation styles. In the case of the formatted processable document architecture class, other constituents are present but these do not affect the imaging process.
+
+Specifically, this clause provides a description of those functions which the document imaging process provides when processing grid frames that include a layout grid.
+
+The functions described in this clause are all additional to the functions described in clause 11 of ITU-T Rec. T.412 | ISO/IEC 8613-2. Hence, they do not affect the definition of the reference model of the document imaging process provided by clause 11 of ITU-T Rec. T.412 | ISO/IEC 8613-2.
+
+The functions described here are:
+
+- generation of images of layout grid lines;
+- generation of images of supplementary lines composing tabular layout.
+
+#### 14.1 Generation of images of layout grid lines
+
+The imaging process identifies the direction, position, dimension and imaging factors of each grid line segment, and then images the grid line segment according to the information identified.
+
+##### 14.1.1 Direction of a grid line segment
+
+If a grid line segment is a segment of a major / minor layout grid line, the grid line segment is called a *major / minor grid line segment*.
+
+The attributes “major / minor path” applied to the grid frame concerned specify the direction of the major / minor path within the grid frame, and hence the direction of minor / major grid line segments respectively.
+
+##### 14.1.2 Position and dimension of a grid line segment
+
+A grid frame that include a layout grid is characterized by the attribute “grid interval dimensions” specified in its object description.
+
+The value of each parameter of the attribute is a grid interval expression of a grid sequence construction type consisting of interval indicators such that every interval indicator involved has the parameter “fixed dimension” associated with a non-negative integer (see 13.3).
+
+Each interval indicator involved in the parameter “major / minor interval dimensions” corresponds to an individual major / minor grid interval, and the non-negative integer specified for the parameter “fixed dimension” specifies the dimension of the corresponding grid interval, measured in scaled measurement units.
+
+The position of the grid origin of the layout grid concerned is specified by the attribute “grid position” applied to the grid frame (see 12.1.6).
+
+Hence, the position and dimension of each line segment are determined in accordance with the attributes “grid interval dimensions” and “grid position” applied to the grid frame.
+
+### **14.1.3 Imaging factors for a grid line segment**
+
+The attribute “grid lines” applied to a grid frame specifies imaging factors (the line width, line type and line colour) of the line segments composing the layout grid within the grid frame.
+
+Evaluation of a grid line segment specified for the parameter “major / minor grid lines” of the attribute provides the line segment characteristics to be applied to the major / minor grid line segments (see 13.4).
+
+## **14.2 Generation of images of supplementary lines**
+
+The imaging process may image one or more lines within a grid frame in accordance with the attribute “supplementary lines” applied to the grid frame.
+
+The attribute “supplementary lines” consists of one or more entries each of which is a triplet of the parameters “start”, “end” and “imaging factors”.
+
+Each entry in the attribute specifies the direction, position, dimension and imaging factors to be used in imaging an individual line:
+
+- The parameter “start” specifies the position of the starting point of the line to which the entry applies. The value is the horizontal and vertical distance of the starting point from the reference point of the grid frame measured in scaled measurement units.
+- The parameter “end” specifies the position of the end point of the line to which the entry applies. The value is the horizontal and vertical distance of the end point from the reference point of the grid frame measured in scaled measurement units.
+- The parameter “imaging factors” specifies a line segment characteristic indicating the imaging factors of the line to which the entry applies (see 11.10).
+
+## **Annex A**
+
+### **Formal definition of tabular structures and tabular layout**
+
+(This annex forms an integral part of this Recommendation | International Standard)
+
+Since this Specification defines a number of attributes in addition to those defined in ITU-T Rec. T.412 | ISO/IEC 8613-2, the formal definition given in ITU-T Rec. T.415 | ISO/IEC 8613-5, ITU-T Rec. T.416 | ISO/IEC 8613-6, ITU-T Rec. T.417 | ISO/IEC 8613-7 and ITU-T Rec. T.418 | ISO/IEC 8613-8 is no longer sufficient to define:
+
+- the format of the data stream used to interchange documents structured in accordance with the conjunction of ITU-T Rec. T.412 | ISO/IEC 8613-2 and this Specification;
+
+- the representation of the constituents which may appear in an interchanged document including tabular materials.
+
+This annex provides sufficient descriptions of ODIF for documents structured in accordance with the conjunction of ITU-T Rec. T.412 | ISO/IEC 8613-2 and this Specification.
+
+Since almost all formal definition given in ITU-T Rec. T.415 | ISO/IEC 8613-5, ITU-T Rec. T.416 | ISO/IEC 8613-6, ITU-T Rec. T.417 | ISO/IEC 8613-7 and ITU-T Rec. T.418 | ISO/IEC 8613-8 remains compatible with the definition introduced by this Specification, this Specification provides only necessary amendments to them to avoid repeating the bulky descriptions that have been already given in those parts. The following components are amended:
+
+- Layout-Descriptors { 2 8 1 5 8 };
+- Logical-Descriptors { 2 8 1 5 9 };
+- Style-Descriptors { 2 8 1 5 10 };
+- Default-Value-Lists { 2 8 1 5 11 };
+- Character-Presentation-Attributes { 2 8 1 6 2 };
+- Raster-Gr-Presentation-Attributes { 2 8 1 7 2 };
+- Geo-Gr-Presentation-Attributes { 2 8 1 8 2 }.
+
+Furthermore, the additional descriptions introduced by this Specification are structured into the two components:
+
+- Grid-Layout-Descriptors { 2 8 1 11 1 };
+- Grid-Style-Descriptors { 2 8 1 11 2 }.
+
+Those components export types to and import types from the existing components defined in ITU-T Rec. T.415 | ISO/IEC 8613-5, ITU-T Rec. T.416 | ISO/IEC 8613-6, ITU-T Rec. T.417 | ISO/IEC 8613-7 and ITU-T Rec. T.418 | ISO/IEC 8613-8.
+
+## A.1 Layout descriptors
+
+Layout-Descriptors { 2 8 1 5 8 }
+
+**DEFINITIONS ::= BEGIN**
+
+**EXPORTS**
+
+-- Put here the descriptions for EXPORTS in 7.9  
+-- of ITU-T Rec. T.415 | ISO/IEC 8613-5. --  
+;
+
+**IMPORTS**
+
+-- Put here the descriptions for IMPORTS in 7.9  
+-- of ITU-T Rec. T.415 | ISO/IEC 8613-5. --  
+-- Append the following items. --  
+**Frame-Alignment-Point,**  
+**Grid-Dimensions, Grid-Gutters,**  
+**Grid-Interval-Dimensions,**  
+**Grid-Lines, Grid-Position,**  
+**Indent,**  
+**Major-Path, Minor-Path,**  
+**Reference-Line-Alignment,**  
+**Supplementary-Lines**  
+**FROM Grid-Layout-Descriptors { 2 8 1 11 1 };**
+
+**Position-Spec-Grid ::= SET {**
+
+**offset**
+
+**leading**
+
+**trailing**
+
+**left-hand**
+
+**right-hand**
+
+**separation**
+
+**leading**
+
+**trailing**
+
+**centre**
+
+**alignment**
+
+**fill-order**
+
+**[0] IMPLICIT SET {**
+
+**[0] IMPLICIT INTEGER OPTIONAL,**
+
+**[1] IMPLICIT INTEGER OPTIONAL,**
+
+**[2] IMPLICIT INTEGER OPTIONAL,**
+
+**[3] IMPLICIT INTEGER OPTIONAL } OPTIONAL,**
+
+**[1] IMPLICIT SET {**
+
+**[0] IMPLICIT INTEGER OPTIONAL,**
+
+**[1] IMPLICIT INTEGER OPTIONAL,**
+
+**[2] IMPLICIT INTEGER OPTIONAL } OPTIONAL,**
+
+**[2] IMPLICIT INTEGER {**
+
+**right-hand (0), centred (1),**
+
+**left-hand (2) } OPTIONAL,**
+
+**[3] IMPLICIT INTEGER {**
+
+**normal (0), reverse (1), centre (2) } OPTIONAL }**
+
+-- Put here the descriptions for types from
+
+**ISO/IEC 8613-11 : 1995 (E)**
+
+```
+-- Dimension-Pair
+-- to
+-- Layout-Object-Descriptor
+-- in 7.9 of ITU-T Rec. T.415 | ISO/IEC 8613-5. --
+```
+
+```
+Layout-Object-Type ::= INTEGER { document-layout-root (0),
+                                  page-set (1), page (2), frame (3), block (4), grid-frame (5) }
+```
+
+```
+Layout-Object-Descriptor-Body ::= SET {
+                                    -- Put here the descriptions for Layout-Object-Descriptor-Body
+                                    -- in 7.9 of ITU-T Rec. T.415 | ISO/IEC 8613-5. --
+                                    -- Append the following descriptions. --
+    frame-alignment-point           [38] Frame-Alignment-Point OPTIONAL,
+    grid-dimensions                 [39] IMPLICIT Grid-Dimensions OPTIONAL,
+    grid-gutters                    [40] IMPLICIT Grid-Gutters OPTIONAL,
+    grid-interval-dimensions        [41] IMPLICIT Grid-Interval-Dimensions OPTIONAL,
+    grid-lines                      [42] IMPLICIT Grid-Lines OPTIONAL,
+    grid-position                   [43] Grid-Position OPTIONAL,
+    major-path                      [44] IMPLICIT Major-Path OPTIONAL,
+    minor-path                      [45] IMPLICIT Minor-Path OPTIONAL,
+    supplementary-lines             [46] IMPLICIT Supplementary-Lines OPTIONAL }
+-- Put here the descriptions for Layout-Class-Descriptor
+-- in 7.9 of ITU-T Rec. T.415 | ISO/IEC 8613-5. --
+```
+
+```
+Layout-Class-Descriptor-Body ::= SET {
+                                    -- Put here the descriptions for Layout-Class-Descriptor-Body
+                                    -- in 7.9 of ITU-T Rec. T.415 | ISO/IEC 8613-5,
+                                    -- except for the descriptions for position. --
+                                    -- Append the following descriptions. --
+    position                        CHOICE {
+        fixed-position                  [3] IMPLICIT Measure-Pair,
+        variable-position               [26] IMPLICIT Position-Spec-Grid } OPTIONAL,
+    frame-alignment-point           [38] Frame-Alignment-Point OPTIONAL,
+    grid-dimensions                 [39] IMPLICIT Grid-Dimensions OPTIONAL,
+    grid-gutters                    [40] IMPLICIT Grid-Gutters OPTIONAL,
+    grid-interval-dimensions        [41] IMPLICIT Grid-Interval-Dimensions OPTIONAL,
+    grid-lines                      [42] IMPLICIT Grid-Lines OPTIONAL,
+    grid-position                   [43] Grid-Position OPTIONAL,
+    major-path                      [44] IMPLICIT Major-Path OPTIONAL,
+    minor-path                      [45] IMPLICIT Minor-Path OPTIONAL,
+    supplementary-lines             [46] IMPLICIT Supplementary-Lines OPTIONAL,
+    indent-major                    [47] IMPLICIT Indent OPTIONAL,
+    indent-minor                    [48] IMPLICIT Indent OPTIONAL,
+    reference-line-alignment-major  [50] IMPLICIT Reference-Line-Alignment OPTIONAL,
+    reference-line-alignment-minor  [51] IMPLICIT Reference-Line-Alignment OPTIONAL }
+END
+```
+
+### A.2 Logical descriptors
+
+Logical-Descriptors { 2 8 1 5 9 }
+
+```
+DEFINITIONS ::= BEGIN
+-- Put here the descriptions for
+-- EXPORTS
+-- IMPORTS
+-- Logical-Object-Descriptor
+-- in 7.10 of ITU-T Rec. T.415 | ISO/IEC 8613-5. --
+```
+
+```
+Logical-Object-Type ::= INTEGER { document-logical-root (0),
+                                  composite-logical-object (1),
+                                  basic-logical-object (2),
+                                  grid-logical-object (3) }
+```
+
+```
+-- Put here the descriptions for types from
+-- Logical-Object-Descriptor-Body
+-- to
+```
+
+82 ITU-T Rec. T.421 (1994 E)
+
+```
+-- Protection
+-- in 7.10 of ITU-T Rec. T.415 | ISO/IEC 8613-5. --
+END
+```
+
+### A.3 Style descriptors
+
+Style-Descriptors { 2 8 1 5 10 }
+
+**DEFINITIONS ::= BEGIN**
+
+```
+EXPORTS
+-- Put here the descriptions for EXPORTS in 7.11
+-- of ITU-T Rec. T.415 | ISO/IEC 8613-5. --
+;
+```
+
+```
+IMPORTS
+-- Put here the descriptions for IMPORTS in 7.11
+-- of ITU-T Rec. T.415 | ISO/IEC 8613-5. --
+-- Append the following descriptions. --
+Block-Alignment-Point,
+Grid-Description, Grid-Frame-Classes,
+Obligatory-Same-Layout-Objects,
+Presentation-Precedence,
+Selective-Same-Layout-Objects,
+Supplementary-Line-Directive
+FROM Grid-Style-Descriptors { 2 8 1 11 2 };
+```
+
+```
+-- Put here the descriptions for types from
+-- Presentation-Style-Descriptor
+-- to
+-- Layout-Style-Descriptor
+-- in 7.11 of ITU-T Rec. T.415 | ISO/IEC 8613-5. --
+```
+
+**Layout-Directives ::= SET {**
+
+```
+-- Put here the descriptions for Layout-Directives
+-- in 7.11 of ITU-T Rec. T.415 | ISO/IEC 8613-5. --
+-- Append the following descriptions. --
+block-alignment-point [25] Block-Alignment-Point OPTIONAL,
+presentation-precedence [26] IMPLICIT Presentation-Precedence OPTIONAL,
+grid-frame-classes [27] Grid-Frame-Classes OPTIONAL,
+obligatory-same-layout-objects [28] IMPLICIT Obligatory-Same-Layout-Objects OPTIONAL,
+selective-same-layout-objects [29] IMPLICIT Selective-Same-Layout-Objects OPTIONAL,
+supplementary-line-directive [30] IMPLICIT Supplementary-Line-Directive OPTIONAL,
+grid-description [31] IMPLICIT Grid-Description OPTIONAL }
+-- Put here the descriptions for types from
+-- Separation
+-- to
+-- Block-Alignment
+-- in 7.11 of ITU-T Rec. T.415 | ISO/IEC 8613-5. --
+END
+```
+
+### A.4 Default value lists
+
+Default-Value-Lists { 2 8 1 5 11 }
+
+**DEFINITIONS ::= BEGIN**
+
+```
+EXPORTS
+-- Put here the descriptions for EXPORTS in 7.12
+-- of ITU-T Rec. T.415 | ISO/IEC 8613-5. --
+;
+```
+
+```
+IMPORTS
+-- Put here the descriptions for IMPORTS in 7.12
+-- of ITU-T Rec. T.415 | ISO/IEC 8613-5. --
+-- Append the following descriptions. --
+Frame-Alignment-Point,
+Grid-Dimensions, Grid-Gutters,
+Grid-Lines, Grid-Position,
+Major-Path, Minor-Path,
+Supplementary-Lines
+FROM Grid-Layout-Descriptors { 2 8 1 11 1 };
+```
+
+```
+-- Put here the descriptions for types from
+-- Default-Value-Lists-Layout
+-- to
+```
+
+-- Page-Attributes  
+ -- in 7.12 of ITU-T Rec. T.415 | ISO/IEC 8613-5. --
+
+**Frame-Attributes ::= SET {**
+
+|                                                     |                                                     |
+|-----------------------------------------------------|-----------------------------------------------------|
+|                                                     | -- Put here the descriptions for Frame-Attributes   |
+|                                                     | -- in 7.12 of ITU-T Rec. T.415   ISO/IEC 8613-5. -- |
+| <b>frame-alignment-point</b>                        | <b>&lt; Attribute OPTIONAL,</b>                     |
+| <b>grid-dimensions</b>                              | <b>&lt; Attribute OPTIONAL,</b>                     |
+| <b>grid-gutters</b>                                 | <b>&lt; Attribute OPTIONAL,</b>                     |
+| <b>grid-lines</b>                                   | <b>&lt; Attribute OPTIONAL,</b>                     |
+| <b>grid-position</b>                                | <b>&lt; Attribute OPTIONAL,</b>                     |
+| <b>major-path</b>                                   | <b>&lt; Attribute OPTIONAL,</b>                     |
+| <b>minor-path</b>                                   | <b>&lt; Attribute OPTIONAL,</b>                     |
+| <b>supplementary-lines</b>                          | <b>&lt; Attribute OPTIONAL }</b>                    |
+| -- Put here the descriptions for types from         |                                                     |
+| -- Block-Attributes                                 |                                                     |
+| -- to                                               |                                                     |
+| -- Basic-Logical-Attributes                         |                                                     |
+| -- in 7.12 of ITU-T Rec. T.415   ISO/IEC 8613-5. -- |                                                     |
+
+**Attribute ::= CHOICE {**
+
+|                              |                                                     |
+|------------------------------|-----------------------------------------------------|
+|                              | -- Put here the descriptions for Attribute          |
+|                              | -- in 7.12 of ITU-T Rec. T.415   ISO/IEC 8613-5. -- |
+|                              | -- Append the following descriptions. --            |
+| <b>frame-alignment-point</b> | <b>[21] Frame-Alignment-Point,</b>                  |
+| <b>grid-dimensions</b>       | <b>[22] IMPLICIT Grid-Dimensions,</b>               |
+| <b>grid-gutters</b>          | <b>[23] IMPLICIT Grid-Gutters,</b>                  |
+| <b>grid-lines</b>            | <b>[24] IMPLICIT Grid-Lines,</b>                    |
+| <b>grid-position</b>         | <b>[25] Grid-Position,</b>                          |
+| <b>major-path</b>            | <b>[26] IMPLICIT Major-Path,</b>                    |
+| <b>minor-path</b>            | <b>[27] IMPLICIT Minor-Path,</b>                    |
+| <b>supplementary-lines</b>   | <b>[28] IMPLICIT Supplementary-Lines }</b>          |
+
+**END**
+
+## A.5 Character presentation attributes
+
+Character-Presentation-Attributes { 2 8 1 6 2 }
+
+**DEFINITIONS ::= BEGIN**
+
+**EXPORTS**
+
+|  |                                                  |
+|--|--------------------------------------------------|
+|  | -- Put here the descriptions for EXPORTS in 11.2 |
+|  | -- of ITU-T Rec. T.416   ISO/IEC 8613-6. --      |
+|  | ;                                                |
+
+**Character-Attributes ::= SET {**
+
+|                                                     |                                                       |
+|-----------------------------------------------------|-------------------------------------------------------|
+|                                                     | -- Put here the descriptions for Character-Attributes |
+|                                                     | -- in 11.2 of ITU-T Rec. T.416   ISO/IEC 8613-6. --   |
+|                                                     | -- Append the following item. --                      |
+| <b>alignment-point</b>                              | <b>[25] Alignment-Point-Char OPTIONAL }</b>           |
+| -- Put here the descriptions for types from         |                                                       |
+| -- One-of-Four-Angles                               |                                                       |
+| -- to                                               |                                                       |
+| -- Pairwise-Kerning                                 |                                                       |
+| -- in 11.2 of ITU-T Rec. T.416   ISO/IEC 8613-6. -- |                                                       |
+| -- Append the following descriptions. --            |                                                       |
+
+**Alignment-Point-Char ::= SET {**
+
+|                                     |                                             |
+|-------------------------------------|---------------------------------------------|
+| <b>position-in-character-path</b>   | <b>CHOICE {</b>                             |
+| <b>alignment-string</b>             | <b>[0] IMPLICIT OCTET STRING,</b>           |
+|                                     | -- string of graphic characters             |
+|                                     | -- from the set of graphic elements         |
+|                                     | -- specified by the presentation attributes |
+|                                     | -- "graphic character sets" and             |
+|                                     | -- "graphic character subrepertoire"        |
+| <b>start</b>                        | <b>[1] IMPLICIT NULL,</b>                   |
+| <b>end</b>                          | <b>[2] IMPLICIT NULL,</b>                   |
+| <b>centre</b>                       | <b>[3] IMPLICIT NULL } OPTIONAL,</b>        |
+| <b>position-in-line-progression</b> | <b>CHOICE {</b>                             |
+| <b>baseline-number</b>              | <b>[4] IMPLICIT INTEGER,</b>                |
+| <b>top</b>                          | <b>[5] IMPLICIT NULL,</b>                   |
+| <b>bottom</b>                       | <b>[6] IMPLICIT NULL,</b>                   |
+
+```
+
+        centre                          [7]  IMPLICIT NULL,
+        top-baseline                    [8]  IMPLICIT NULL,
+        bottom-baseline                 [9]  IMPLICIT NULL,
+        top-middle-baseline             [10] IMPLICIT NULL,
+        bottom-middle-baseline          [11] IMPLICIT NULL } OPTIONAL }
+END
+
+```
+
+## A.6 Raster graphics presentation attributes
+
+Raster-Gr-Presentation-Attributes { 2 8 1 7 2 }
+
+**DEFINITIONS ::= BEGIN**
+
+```
+
+EXPORTS                         -- Put here the descriptions for EXPORTS in 10.2
+                                -- of ITU-T Rec. T.417 | ISO/IEC 8613-7. --
+;
+
+```
+
+```
+
+Raster-Graphics-Attributes ::= SET {
+-- Put here the descriptions for Raster-Graphics-Attributes
+-- in 10.2 of ITU-T Rec. T.417 | ISO/IEC 8613-7. --
+-- Append the following item. --
+
+```
+
+```
+
+    alignment-point             [8] Alignment-Point-Raster-Gr OPTIONAL }
+
+-- Put here the descriptions for types from
+-- One-of-Four-Angles
+-- to
+-- Image-Dimensions
+-- in 10.2 of ITU-T Rec. T.417 | ISO/IEC 8613-7. --
+-- Append the following descriptions. --
+
+```
+
+```
+
+Alignment-Point-Raster-Gr ::= SET {
+    position-in-pel-path        [0] IMPLICIT INTEGER {
+                                    start (0), end (1), centre (2) } OPTIONAL,
+    position-in-line-progression [1] IMPLICIT INTEGER {
+                                    top (0), bottom (1), centre (2) } OPTIONAL }
+
+```
+
+**END**
+
+## A.7 Geometric graphics presentation attributes
+
+Geo-Gr-Presentation-Attributes { 2 8 1 8 2 }
+
+**DEFINITIONS ::= BEGIN**
+
+```
+
+EXPORTS                         -- Put here the descriptions for EXPORTS in 10.2
+                                -- of ITU-T Rec. T.418 | ISO/IEC 8613-8. --
+;
+
+```
+
+```
+
+Geometric-Graphics-Attributes ::= SET {
+-- Put here the descriptions for Geometric-Graphics-Attributes
+-- in 10.2 of ITU-T Rec. T.418 | ISO/IEC 8613-8. --
+-- Append the following item. --
+
+```
+
+```
+
+    alignment-point             [12] Alignment-Point-Geo-Gr OPTIONAL }
+
+-- Put here the descriptions for types from
+-- ASF-Type
+-- to
+-- Picture-Dimensions
+-- in 10.2 of ITU-T Rec. T.418 | ISO/IEC 8613-8. --
+-- Append the following descriptions. --
+
+```
+
+```
+
+Alignment-Point-Geo-Gr ::= SET {
+    position-in-x-axis          [0] IMPLICIT INTEGER {
+                                    start (0), end (1), centre (2) } OPTIONAL,
+    position-in-y-axis          [1] IMPLICIT INTEGER {
+                                    top (0), bottom (1), centre (2) } OPTIONAL }
+
+```
+
+**END**
+
+
+
+Grid-Gutter-Construction-Factor ::= CHOICE {  
+     gutter-indicator [3] Gutter-Indicator,  
+     construction-type Grid-Gutter-Construction-Type }
+
+Gutter-Indicator ::= SEQUENCE {  
+     gutter-space-width [0] IMPLICIT INTEGER OPTIONAL,  
+     precedence [1] IMPLICIT INTEGER OPTIONAL }
+
+Grid-Line-Expression ::= CHOICE {  
+     construction-type Grid-Line-Construction-Type,  
+     single-term-construction [3] Grid-Line-Construction-Term }
+
+Grid-Line-Construction-Type ::= CHOICE {  
+     sequence-construction [0] IMPLICIT Grid-Line-Term-Sequence,  
+     aggregate-construction [1] IMPLICIT Grid-Line-Term-Sequence,  
+     choice-construction [2] IMPLICIT Grid-Line-Term-Sequence }
+
+Grid-Line-Term-Sequence ::= SEQUENCE OF Grid-Line-Construction-Term
+
+Grid-Line-Construction-Term ::= CHOICE {  
+     required-construction-factor [0] Grid-Line-Construction-Factor,  
+     optional-construction-factor [1] Grid-Line-Construction-Factor,  
+     repetitive-construction-factor [2] Grid-Line-Construction-Factor,  
+     optional-repetitive-factor [3] Grid-Line-Construction-Factor }
+
+Grid-Line-Construction-Factor ::= CHOICE {  
+     line-char-expr-with-precedence [3] IMPLICIT SET {  
+         line-char-expression [0] Line-Char-Expression,  
+         precedence [1] IMPLICIT INTEGER OPTIONAL },  
+     construction-type Grid-Line-Construction-Type }
+
+Line-Char-Expression ::= CHOICE {  
+     construction-type Line-Char-Construction-Type,  
+     single-term-construction [3] Line-Char-Construction-Term }
+
+-- NOTE – "Char" stands for "Characteristic".
+
+Line-Char-Construction-Type ::= CHOICE {  
+     sequence-construction [0] IMPLICIT Line-Char-Term-Sequence,  
+     aggregate-construction [1] IMPLICIT Line-Char-Term-Sequence,  
+     choice-construction [2] IMPLICIT Line-Char-Term-Sequence }
+
+Line-Char-Term-Sequence ::= SEQUENCE OF Line-Char-Construction-Term
+
+Line-Char-Construction-Term ::= CHOICE {  
+     required-construction-factor [0] Line-Char-Construction-Factor,  
+     optional-construction-factor [1] Line-Char-Construction-Factor,  
+     repetitive-construction-factor [2] Line-Char-Construction-Factor,  
+     optional-repetitive-factor [3] Line-Char-Construction-Factor }
+
+Line-Char-Construction-Factor ::= CHOICE {  
+     line-segment-characteristic [3] Line-Segment-Characteristic,  
+     construction-type Line-Char-Construction-Type }
+
+Line-Segment-Characteristic ::= SEQUENCE {  
+     line-width [0] IMPLICIT INTEGER OPTIONAL,  
+     line-type [1] IMPLICIT INTEGER {  
+         invisible (0), solid (1), dashed (2),  
+         dot (3), dash-dot (4), dash-dot-dot (5),  
+         double (6) } OPTIONAL,  
+     line-colour Grid-Line-Colour OPTIONAL }
+
+Grid-Line-Colour ::= CHOICE {  
+     implementation-defined [3] IMPLICIT NULL,  
+     colour-expression Colour-Expression }
+
+Frame-Alignment-Point ::= CHOICE {  
+     fixed-position [0] IMPLICIT SET {  
+         vertical-position [0] IMPLICIT INTEGER OPTIONAL,  
+         horizontal-position [1] IMPLICIT INTEGER OPTIONAL },  
+     variable-position [1] IMPLICIT SET {  
+         vertical-alignment [0] IMPLICIT INTEGER {  
+             top (0), centre (1), bottom (2)  
+         } OPTIONAL,  
+         horizontal-alignment [1] IMPLICIT INTEGER {  
+             left (0), centre (1), right (2)  
+         } OPTIONAL },
+
+subordinate-dependent [2] IMPLICIT INTEGER { first (0), last (1) }  
+}
+
+Major-Path ::= One-Of-Four-Angles
+
+Minor-Path ::= One-Of-Two-Angles
+
+One-Of-Two-Angles ::= INTEGER { d90 (0), d270 (1) }
+
+Reference-Line-Alignment ::= SET {  
+aligned-with [0] IMPLICIT SET OF Object-or-Class-Identifier OPTIONAL,  
+reference-line [1] IMPLICIT Line-Segment-Characteristic OPTIONAL }
+
+Indent ::= INTEGER
+
+Grid-Position ::= CHOICE {  
+fixed-position [0] IMPLICIT SET {  
+major-position [0] IMPLICIT INTEGER,  
+minor-position [1] IMPLICIT INTEGER },  
+variable-position [1] IMPLICIT SET {  
+major-alignment [0] IMPLICIT INTEGER {  
+right-hand-aligned (0), centred (1),  
+left-hand-aligned (2) } OPTIONAL,  
+minor-alignment [1] IMPLICIT INTEGER {  
+right-hand-aligned (0), centred (1),  
+left-hand-aligned (2) } OPTIONAL }  
+}
+
+Grid-Dimensions ::= SET {  
+major-dimension [0] CHOICE {  
+fixed-dimension [0] IMPLICIT INTEGER,  
+[1] IMPLICIT INTEGER {  
+rule-b (0), expansive (1) } } OPTIONAL,  
+minor-dimension [1] CHOICE {  
+fixed-dimension [0] IMPLICIT INTEGER,  
+[1] IMPLICIT INTEGER {  
+rule-b (0), expansive (1) } } OPTIONAL  
+}
+
+Grid-Lines ::= SET {  
+major-grid-line [0] Grid-Line-Expression OPTIONAL,  
+minor-grid-line [1] Grid-Line-Expression OPTIONAL }
+
+Grid-Interval-Dimensions ::= SET {  
+major-interval-dimensions [0] Grid-Interval-Expression OPTIONAL,  
+minor-interval-dimensions [1] Grid-Interval-Expression OPTIONAL }
+
+Grid-Gutters ::= SET {  
+around-major-grid-lines [0] Grid-Gutter-Expression OPTIONAL,  
+around-minor-grid-lines [1] Grid-Gutter-Expression OPTIONAL }
+
+Supplementary-Lines ::= SEQUENCE OF Supplementary-Line
+
+Supplementary-Line ::= SET {  
+start [0] IMPLICIT SEQUENCE {  
+start-major [0] IMPLICIT INTEGER,  
+start-minor [1] IMPLICIT INTEGER },  
+end [1] IMPLICIT SEQUENCE {  
+end-major [0] IMPLICIT INTEGER,  
+end-minor [1] IMPLICIT INTEGER },  
+imaging-factors [2] IMPLICIT Line-Segment-Characteristic OPTIONAL }  
+END
+
+## A.9 Grid style descriptors
+
+Grid-Style-Descriptors { 2 8 1 11 2 }
+
+DEFINITIONS ::= BEGIN
+
+EXPORTS
+
+Block-Alignment-Point,  
+Grid-Description, Grid-Frame-Classes,  
+Obligatory-Same-Layout-Objects,  
+Presentation-Precedence,  
+Selective-Same-Layout-Objects,  
+Supplementary-Line-Directive;
+
+**IMPORTS**
+
+Object-or-Class-Identifier,  
+ Construction-Expression  
+ FROM Identifiers-and-Expressions { 2 8 1 5 7 }  
+ Line-Segment-Characteristic  
+ FROM Grid-Layout-Descriptors;
+
+**Block-Alignment-Point ::= CHOICE {**  
+   content-dependent [0] IMPLICIT NULL,  
+   fixed-position [1] IMPLICIT SET {  
+     vertical-position [0] IMPLICIT INTEGER OPTIONAL,  
+     horizontal-position [1] IMPLICIT INTEGER OPTIONAL },  
+   variable-position [2] IMPLICIT SET {  
+     vertical-alignment [0] IMPLICIT INTEGER {  
+       top (0), centre (1), bottom (2) } OPTIONAL,  
+     horizontal-alignment [1] IMPLICIT INTEGER {  
+       left (0), centre (1), right (2) } OPTIONAL }  
+   }  
+**Grid-Description ::= SET {**  
+   major-size [0] IMPLICIT INTEGER OPTIONAL,  
+   minor-size [1] IMPLICIT INTEGER OPTIONAL,  
+   entry-location-association [2] IMPLICIT  
+     Entry-Location-Associations OPTIONAL  
+   }  
+**Entry-Location-Associations ::= SET OF Entry-Location-Association**  
+**Entry-Location-Association ::= SET {**  
+   locations [0] IMPLICIT SEQUENCE {  
+     vertex-major [0] Grid-Coordinate,  
+     vertex-minor [1] Grid-Coordinate,  
+     opposite-vertex-major [2] Grid-Coordinate OPTIONAL,  
+     opposite-vertex-minor [3] Grid-Coordinate OPTIONAL } OPTIONAL,  
+   entries [1] IMPLICIT SET OF  
+     Object-or-Class-Identifier OPTIONAL  
+   }  
+**Grid-Coordinate ::= CHOICE {**  
+   last [0] IMPLICIT INTEGER,  
+       [1] IMPLICIT NULL }  
+**Presentation-Precedence ::= INTEGER { major (0), minor (1) }**  
+**Grid-Frame-Classes ::= Construction-Expression**  
+**Obligatory-Same-Layout-Objects ::= SET {**  
+   logical-objects [0] IMPLICIT SET OF Object-or-Class-Identifier,  
+   layout-objects [1] IMPLICIT SET OF Object-or-Class-Identifier }  
+**Selective-Same-Layout-Objects ::= SET {**  
+   logical-objects [0] IMPLICIT SET OF Object-or-Class-Identifier,  
+   layout-objects [1] IMPLICIT SET OF Object-or-Class-Identifier }  
+**Supplementary-Line-Directive ::= SEQUENCE OF Supplementary-Line-Directive-Unit**  
+**Supplementary-Line-Directive-Unit ::= SEQUENCE {**  
+   start [0] IMPLICIT SEQUENCE {  
+     start-major [0] Grid-Coordinate,  
+     start-minor [1] Grid-Coordinate },  
+   end [1] IMPLICIT SEQUENCE {  
+     end-major [0] Grid-Coordinate,  
+     end-minor [1] Grid-Coordinate },  
+   imaging-factors [2] IMPLICIT  
+     Line-Segment-Characteristic OPTIONAL }  
+**END**
+
+## Annex B
+
+## Examples
+
+(This annex does not form an integral part of this Recommendation | International Standard)
+
+## B.1 Example 1
+
+## B.1.1 Generic Layout Structure
+
+|                            |                                                                    |
+|----------------------------|--------------------------------------------------------------------|
+| Object Type                | document layout root                                               |
+| Object Class Identifier    | 0                                                                  |
+| Generator for Subordinates | REP ( 0 0 )                                                        |
+| Object Type                | page                                                               |
+| Object Class Identifier    | 0 0                                                                |
+| Generator for Subordinates | REQ ( 0 0 0 )                                                      |
+| Object Type                | grid frame                                                         |
+| Object Class Identifier    | 0 0 0 (table frame)                                                |
+| Generator for Subordinates | REP ( CHO ( 0 0 0 0, 0 0 0 1, 0 0 0 2, 0 0 0 3 ) )                 |
+| Layout Path                | 270                                                                |
+| Dimensions                 |                                                                    |
+| Horizontal Dimension       |                                                                    |
+| Fixed Dimension            | 300 (SMU)                                                          |
+| Vertical Dimension         |                                                                    |
+| Fixed Dimension            | 120 (SMU)                                                          |
+| Border                     |                                                                    |
+| Left Hand Edge             |                                                                    |
+| Border Freespace Width     | 15 (SMU)                                                           |
+| Right Hand Edge            |                                                                    |
+| Border Freespace Width     | 15 (SMU)                                                           |
+| Trailing Edge              |                                                                    |
+| Border Freespace Width     | 15 (SMU)                                                           |
+| Leading Edge               |                                                                    |
+| Border Freespace Width     | 15 (SMU)                                                           |
+| Major Path                 | 270                                                                |
+| Minor Path                 | 90                                                                 |
+| Grid Position              |                                                                    |
+| Variable Position          |                                                                    |
+| Major Alignment            | left-aligned                                                       |
+| Minor Alignment            | centred                                                            |
+| Grid Dimensions            |                                                                    |
+| Major                      | rule b                                                             |
+| Minor                      | rule b                                                             |
+| Grid Interval Dimensions   |                                                                    |
+| Major Interval Dimensions  | SEQ (                                                              |
+|                            | rule-b { minimum = 40 , },                                         |
+|                            | OPTREP ( proportional { group = 0, im-dim = 1, default = 0 } )     |
+|                            | )                                                                  |
+| Minor Interval Dimensions  | SEQ (                                                              |
+|                            | fixed-dimension { 100 },                                           |
+|                            | OPTREP ( proportional { group = 1, im-dim = 1, default = 0 } ),    |
+|                            | proportional { group = 1, im-dim = 2, }                            |
+|                            | )                                                                  |
+| Grid Lines                 |                                                                    |
+| Major Grid Lines           | SEQ (                                                              |
+|                            | { OPTREP ( { 4, solid, black } ), precedence = 5 },                |
+|                            | { OPTREP ( { 2, solid, black } ), precedence = 4 },                |
+|                            | OPTREP (                                                           |
+|                            | { SEQ ( { 1, invisible, black }, OPTREP ( { 1, solid, black } ) ), |
+|                            | precedence = 0 }                                                   |
+|                            | ),                                                                 |
+|                            | { OPTREP ( { 4, solid, black } ), precedence = 5 }                 |
+|                            | )                                                                  |
+| Minor Grid Lines           | SEQ (                                                              |
+
+{ OPTREP ( { 4, solid, black } ), precedence = 5 },  
+{ OPTREP ( { 2, solid, black } ), precedence = 4 },  
+OPTREP (  
+    { OPTREP ( { 1, dashed, black } ), precedence = 0 }  
+),  
+{ OPTREP ( { 1, solid, black } ), precedence = 1 },  
+{ OPTREP ( { 4, solid, black } ), precedence = 5 }  
+)
+
+**Grid Gutters****Around Major Grid Lines**
+
+OPTREP ( { width = 10, precedence = 0 } )
+
+**Around Minor Grid Lines**
+
+OPTREP ( { width = 10, precedence = 0 } )
+
+**Object Type**
+
+frame
+
+**Object Class Identifier**
+
+0 0 0 0 (entry frame for box headings)
+
+**Position****Variable Position****Fill Order**
+
+reverse
+
+**Offset**
+
+leading = trailing = left-hand = right-hand = 0
+
+**Alignment**
+
+centred
+
+**Object Type**
+
+frame
+
+**Object Class Identifier**
+
+0 0 0 1 (entry frame for row headings)
+
+**Position****Variable Position****Fill Order**
+
+normal
+
+**Offset**
+
+leading = trailing = left-hand = right-hand = 0
+
+**Alignment**
+
+right-hand aligned
+
+**Object Type**
+
+frame
+
+**Object Class Identifier**
+
+0 0 0 2 (entry frame for numeric data)
+
+**Position****Variable Position****Fill Order**
+
+normal
+
+**Offset**
+
+leading = trailing = left-hand = right-hand = 0
+
+**Alignment**
+
+left-hand aligned
+
+**Object Type**
+
+frame
+
+**Object Class Identifier**
+
+0 0 0 3 (entry frame for figure data)
+
+**Position****Variable Position****Fill Order**
+
+centre order
+
+**Offset**
+
+leading = trailing = left-hand = right-hand = 0
+
+**Alignment**
+
+centred
+
+![Figure B.1 – Generic Layout Structure of Example 1. A hierarchical tree diagram showing the structure of a document layout. The root node is '0' (document layout root). It has a child '00' (page) connected by 'REP'. '00' has a child '000' (grid frame (table frame)) connected by 'REQ'. '000' has four children: '0000' (box heading), '0001' (row heading), '0002' (literal data), and '0003' (figure data), all connected by 'REP CHO'.](26299f7378ec209838cd016923e68290_img.jpg)
+
+```
+
+graph TD
+    0[0 document layout root] -- REP --> 00[00 page]
+    00 -- REQ --> 000[000 grid frame table frame]
+    000 -- "REP CHO" --> 0000[0000 box heading]
+    000 -- "REP CHO" --> 0001[0001 row heading]
+    000 -- "REP CHO" --> 0002[0002 literal data]
+    000 -- "REP CHO" --> 0003[0003 figure data]
+
+```
+
+TIS O5270-95/d24
+
+Figure B.1 – Generic Layout Structure of Example 1. A hierarchical tree diagram showing the structure of a document layout. The root node is '0' (document layout root). It has a child '00' (page) connected by 'REP'. '00' has a child '000' (grid frame (table frame)) connected by 'REQ'. '000' has four children: '0000' (box heading), '0001' (row heading), '0002' (literal data), and '0003' (figure data), all connected by 'REP CHO'.
+
+**Figure B.1 – Generic Layout Structure of Example 1**
+
+### B.1.2 Explanation
+
+The layout object class whose identifier is 0 0 0 defines the generic properties of tabular layout whose example is depicted with Figure B.2. An instance of this grid frame class contains a layout grid which comprises major (horizontal) and minor (vertical) grid lines. The properties of these grid lines, namely their positions, lengths, line types, line widths and line colours, are specified in the layout object class description.
+
+![Figure B.2 – Example 1: A diagram of a tabular layout grid. The grid consists of 2 rows and 7 columns. The first column is 100 SMU wide. The next five columns are each 'Single width', and the last column is 'Double width'. The first row is 40 SMU or over high, and the subsequent four rows are 'Same height'. The grid is drawn with solid lines of varying widths (4 SMU, 2 SMU, 1 SMU) and dashed lines (1 SMU).](c0ca823603794512478906b302176bca_img.jpg)
+
+TIS05280-95/d25
+
+Figure B.2 – Example 1: A diagram of a tabular layout grid. The grid consists of 2 rows and 7 columns. The first column is 100 SMU wide. The next five columns are each 'Single width', and the last column is 'Double width'. The first row is 40 SMU or over high, and the subsequent four rows are 'Same height'. The grid is drawn with solid lines of varying widths (4 SMU, 2 SMU, 1 SMU) and dashed lines (1 SMU).
+
+Figure B.2 – Example 1
+
+The layout object class description 0 0 0 defines the following constraints on tabular layout:
+
+- the table includes one or more rows and one or more columns;
+- the height of the first row is not smaller than 40 SMU;
+- the heights of the following rows are all the same;
+- the width of the first column is 100 SMU;
+- the widths of the following columns except the last one are all the same;
+- the last column is twice as wide as the second column;
+- the four bordering edges of the table are drawn with the wide solid line (4 SMU wide);
+- the separating line of the first and second rows is imaged with the medium wide solid line (2 SMU wide);
+- the other separating lines of adjacent rows are imaged with the narrow solid line (1 SMU wide) within the second and the following columns, and invisible within the first column;
+- the separating line of the first and second columns is drawn with the medium wide solid line (2 SMU wide);
+- the separating line of the last column and its immediately preceding column is drawn with the narrow solid line (1 SMU wide);
+- the other separating lines of adjacent columns are drawn with the narrow dashed line (1 SMU wide);
+- the total width of the table does not exceed 270 SMU;
+- the total height of the table does not exceed 90 SMU;
+- the gutter space width around each line, which specifies a free space around the line to be kept blank, is 10 SMU;
+- the table as a whole is positioned vertically top aligned and horizontally centred within a table frame.
+
+Moreover, the four layout object class descriptions for entry frames, whose identifiers are 0 0 0 0 to 0 0 0 3, define the following constraints on tabular layout:
+
+- the box headings are bottom aligned and horizontally centred;
+- the row headings are top aligned and left-hand aligned (viewed from the reader);
+- the literal data are top aligned and right-hand aligned (viewed from the reader);
+- the figure data are centred in both the horizontal and vertical directions.
+
+**B.2 Example 2****B.2.1 Generic Logical Structure**
+
+|                                |                                                      |
+|--------------------------------|------------------------------------------------------|
+| Object Type                    | document logical root                                |
+| Object Class Identifier        | 2                                                    |
+| Generator for Subordinates     | REQ ( 2 0 )                                          |
+| Object Type                    | grid logical                                         |
+| Object Class Identifier        | 2 0                                                  |
+| Generator for Subordinates     | SEQ ( 2 0 0, OPTREP ( 2 0 1 ) )                      |
+| Grid Frame Classes             | REP ( 0 0 0 ) -- <i>style attribute</i>              |
+| Object Type                    | composite logical                                    |
+| Object Class Identifier        | 2 0 0 (box heading row)                              |
+| Generator for Subordinates     | OPTREP ( 2 0 0 0 )                                   |
+| Object Type                    | basic logical                                        |
+| Object Class Identifier        | 2 0 0 0 (box headings)                               |
+| Layout Object Class            | 0 0 0 0 -- <i>style attribute</i>                    |
+| Object Type                    | composite logical                                    |
+| Object Class Identifier        | 2 0 1 (row)                                          |
+| Generator for Subordinates     | SEQ ( 2 0 1 0, OPTREP ( CHO ( 2 0 1 1, 2 0 1 2 ) ) ) |
+| Obligatory Same Layout Objects | -- <i>style attribute</i>                            |
+| To-Logical-Object-Class        | 2 0 0                                                |
+| To-Layout-Object-Class         | 0 0 0                                                |
+| Object Type                    | basic logical                                        |
+| Object Class Identifier        | 2 0 1 0 (row headings)                               |
+| Layout Object Class            | 0 0 0 1 -- <i>style attribute</i>                    |
+| Object Type                    | basic logical                                        |
+| Object Class Identifier        | 2 0 1 1 (literal data)                               |
+| Layout Object Class            | 0 0 0 2 -- <i>style attribute</i>                    |
+| Object Type                    | composite logical                                    |
+| Object Class Identifier        | 2 0 1 2 (figure data)                                |
+| Generator for Subordinates     | SEQ ( 2 0 1 2 0, 2 0 1 2 1 )                         |
+| Layout Object Class            | 0 0 0 3 -- <i>style attribute</i>                    |
+| Object Type                    | basic logical                                        |
+| Object Class Identifier        | 2 0 1 2 0 (figure)                                   |
+| Block Alignment                | centred -- <i>style attribute</i>                    |
+| Object Type                    | basic logical                                        |
+| Object Class Identifier        | 2 0 1 2 1 (caption)                                  |
+| Block Alignment                | centred -- <i>style attribute</i>                    |
+
+![Figure B.3: Generic Logical Structure of Example 2. A hierarchical tree diagram showing the logical structure of a document. The root is '2' (document logical root), which points to '20' (grid logical (table root)). '20' branches into '200' (box heading row) and '201' (row). '200' points to '2000' (box heading) via 'OPTREP'. '201' branches into '2010' (row heading) and '2012' (figure data) via 'OPTREP CHO'. '2012' branches into '20120' (figure) and '20121' (caption) via 'SEQ'. '2010' points to '2011' (literal data) via 'OPTREP'.](e26bb66586e464339df27951d5c9355e_img.jpg)
+
+```
+
+graph TD
+    2[2] --> 20[20]
+    20 --> 200[200]
+    20 --> 201[201]
+    200 -- OPTREP --> 2000[2000]
+    201 -- OPTREP CHO --> 2010[2010]
+    201 -- OPTREP CHO --> 2012[2012]
+    2012 -- SEQ --> 20120[20120]
+    2012 -- SEQ --> 20121[20121]
+    2010 -- OPTREP --> 2011[2011]
+    
+```
+
+Figure B.3: Generic Logical Structure of Example 2. A hierarchical tree diagram showing the logical structure of a document. The root is '2' (document logical root), which points to '20' (grid logical (table root)). '20' branches into '200' (box heading row) and '201' (row). '200' points to '2000' (box heading) via 'OPTREP'. '201' branches into '2010' (row heading) and '2012' (figure data) via 'OPTREP CHO'. '2012' branches into '20120' (figure) and '20121' (caption) via 'SEQ'. '2010' points to '2011' (literal data) via 'OPTREP'.
+
+TISO5290-95/d26
+
+**Figure B.3 – Generic Logical Structure of Example 2**
+
+## B.2.2 Specific Logical Structure
+
+|                            |                                                                                                                                                                                                                                                                                                                                                                                             |
+|----------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Object Type                | document logical root                                                                                                                                                                                                                                                                                                                                                                       |
+| Object Identifier          | 3                                                                                                                                                                                                                                                                                                                                                                                           |
+| Object Class               | 2                                                                                                                                                                                                                                                                                                                                                                                           |
+| Subordinates               | 0                                                                                                                                                                                                                                                                                                                                                                                           |
+| Object Type                | grid logical                                                                                                                                                                                                                                                                                                                                                                                |
+| Object Identifier          | 3 0                                                                                                                                                                                                                                                                                                                                                                                         |
+| Object Class               | 2 0                                                                                                                                                                                                                                                                                                                                                                                         |
+| Subordinates               | 0, 1, 2                                                                                                                                                                                                                                                                                                                                                                                     |
+| Grid Description           | -- <i>style attribute</i>                                                                                                                                                                                                                                                                                                                                                                   |
+| Major Size                 | 6                                                                                                                                                                                                                                                                                                                                                                                           |
+| Minor Size                 | 5                                                                                                                                                                                                                                                                                                                                                                                           |
+| Entry Location Association | { locations = {(0, 1), }, entries = {0 0} },<br>{ locations = {(0, 2), }, entries = {0 1} },<br>{ locations = {(1, 0), }, entries = {1 0} },<br>{ locations = {(2, 0), }, entries = {2 0} },<br>{ locations = {(1, 1), }, entries = {1 1} },<br>{ locations = {(1, 2), }, entries = {1 2} },<br>{ locations = {(2, 1), }, entries = {2 1} },<br>{ locations = {(2, 2), }, entries = {2 2} } |
+| Object Type                | composite logical                                                                                                                                                                                                                                                                                                                                                                           |
+| Object Identifier          | 3 0 0 (box heading row: 1st row)                                                                                                                                                                                                                                                                                                                                                            |
+| Object Class               | 2 0 0                                                                                                                                                                                                                                                                                                                                                                                       |
+| Subordinates               | 0, 1                                                                                                                                                                                                                                                                                                                                                                                        |
+| Object Type                | basic logical                                                                                                                                                                                                                                                                                                                                                                               |
+| Object Identifier          | 3 0 0 0 (box heading for 2nd column)                                                                                                                                                                                                                                                                                                                                                        |
+| Object Class               | 2 0 0 0                                                                                                                                                                                                                                                                                                                                                                                     |
+| Content Portions           | 0 ('XXX')                                                                                                                                                                                                                                                                                                                                                                                   |
+| Object Type                | basic logical                                                                                                                                                                                                                                                                                                                                                                               |
+| Object Identifier          | 3 0 0 1 (box heading for 3rd column)                                                                                                                                                                                                                                                                                                                                                        |
+| Object Class               | 2 0 0 0                                                                                                                                                                                                                                                                                                                                                                                     |
+| Content Portions           | 0 ('YYY')                                                                                                                                                                                                                                                                                                                                                                                   |
+| Object Type                | composite logical                                                                                                                                                                                                                                                                                                                                                                           |
+| Object Identifier          | 3 0 1 (2nd row)                                                                                                                                                                                                                                                                                                                                                                             |
+| Object Class               | 2 0 1                                                                                                                                                                                                                                                                                                                                                                                       |
+| Subordinates               | 0, 1, 2                                                                                                                                                                                                                                                                                                                                                                                     |
+| Object Type                | basic logical                                                                                                                                                                                                                                                                                                                                                                               |
+| Object Identifier          | 3 0 1 0                                                                                                                                                                                                                                                                                                                                                                                     |
+| Object Class               | 2 0 1 0                                                                                                                                                                                                                                                                                                                                                                                     |
+| Content Portions           | 0 ('AAA')                                                                                                                                                                                                                                                                                                                                                                                   |
+| Object Type                | basic logical                                                                                                                                                                                                                                                                                                                                                                               |
+| Object Identifier          | 3 0 1 1                                                                                                                                                                                                                                                                                                                                                                                     |
+| Object Class               | 2 0 1 1                                                                                                                                                                                                                                                                                                                                                                                     |
+| Content Portions           | 0 ('111111.')                                                                                                                                                                                                                                                                                                                                                                               |
+| Object Type                | basic logical                                                                                                                                                                                                                                                                                                                                                                               |
+| Object Identifier          | 3 0 1 2                                                                                                                                                                                                                                                                                                                                                                                     |
+| Object Class               | 2 0 1 1                                                                                                                                                                                                                                                                                                                                                                                     |
+| Content Portions           | 0 ('22.')                                                                                                                                                                                                                                                                                                                                                                                   |
+| Object Type                | composite logical                                                                                                                                                                                                                                                                                                                                                                           |
+| Object Identifier          | 3 0 2 (3rd row)                                                                                                                                                                                                                                                                                                                                                                             |
+| Object Class               | 2 0 1                                                                                                                                                                                                                                                                                                                                                                                       |
+| Subordinates               | 0, 1, 2                                                                                                                                                                                                                                                                                                                                                                                     |
+| Object Type                | basic logical                                                                                                                                                                                                                                                                                                                                                                               |
+| Object Identifier          | 3 0 2 0                                                                                                                                                                                                                                                                                                                                                                                     |
+| Object Class               | 2 0 1 0                                                                                                                                                                                                                                                                                                                                                                                     |
+| Content Portions           | 0 ('BBB')                                                                                                                                                                                                                                                                                                                                                                                   |
+| Object Type                | basic logical                                                                                                                                                                                                                                                                                                                                                                               |
+| Object Identifier          | 3 0 2 1                                                                                                                                                                                                                                                                                                                                                                                     |
+| Object Class               | 2 0 1 1                                                                                                                                                                                                                                                                                                                                                                                     |
+| Content Portions           | 0 ('33.')                                                                                                                                                                                                                                                                                                                                                                                   |
+| Object Type                | basic logical                                                                                                                                                                                                                                                                                                                                                                               |
+
+|                              |            |
+|------------------------------|------------|
+| Object Identifier            | 3 0 2 2    |
+| Object Class                 | 2 0 1 1    |
+| Content Portions             | 0 ('444.') |
+| Content Identifier – Logical | 3 0 0 0 0  |
+| Content Information          | "XXX"      |
+| Content Identifier – Logical | 3 0 0 1 0  |
+| Content Information          | "YYY"      |
+| Content Identifier – Logical | 3 0 1 0 0  |
+| Content Information          | "AAA"      |
+| Content Identifier – Logical | 3 0 1 1 0  |
+| Content Information          | "111111."  |
+| Content Identifier – Logical | 3 0 1 2 0  |
+| Content Information          | "22."      |
+| Content Identifier – Logical | 3 0 2 0 0  |
+| Content Information          | "BBB"      |
+| Content Identifier – Logical | 3 0 2 1 0  |
+| Content Information          | "33."      |
+| Content Identifier – Logical | 3 0 2 2 0  |
+| Content Information          | "444."     |
+
+### B.2.3 Specific Layout Structure
+
+This subclause provides a description of the specific layout structure which the layout process generates from B.1.1, B.2.1 and B.2.2. The specific layout structure is described in the form of the formatted document architecture.
+
+|                           |                                                                                                                                                                                                                                                                                                                                                                       |
+|---------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Object Type               | document layout root                                                                                                                                                                                                                                                                                                                                                  |
+| Object Identifier         | 1                                                                                                                                                                                                                                                                                                                                                                     |
+| Object Class              | 0                                                                                                                                                                                                                                                                                                                                                                     |
+| Subordinates              | 0                                                                                                                                                                                                                                                                                                                                                                     |
+| Object Type               | page                                                                                                                                                                                                                                                                                                                                                                  |
+| Object Identifier         | 1 0                                                                                                                                                                                                                                                                                                                                                                   |
+| Object Class              | 0 0                                                                                                                                                                                                                                                                                                                                                                   |
+| Subordinates              | 0                                                                                                                                                                                                                                                                                                                                                                     |
+| Object Type               | grid frame                                                                                                                                                                                                                                                                                                                                                            |
+| Object Identifier         | 1 0 0                                                                                                                                                                                                                                                                                                                                                                 |
+| Object Class              | 0 0 0                                                                                                                                                                                                                                                                                                                                                                 |
+| Subordinates              | 0, 1, 2, 3, 4, 5, 6, 7                                                                                                                                                                                                                                                                                                                                                |
+| Dimension                 | HD = 300, VD = 120                                                                                                                                                                                                                                                                                                                                                    |
+| Grid Position             |                                                                                                                                                                                                                                                                                                                                                                       |
+| Fixed Position            |                                                                                                                                                                                                                                                                                                                                                                       |
+| Major Position            | 15                                                                                                                                                                                                                                                                                                                                                                    |
+| Minor Position            | 30                                                                                                                                                                                                                                                                                                                                                                    |
+| Grid Interval Dimensions  |                                                                                                                                                                                                                                                                                                                                                                       |
+| Major Interval Dimensions | SEQ (<br>fixed-dimension { 40 }, fixed-dimension { 22 }, fixed-dimension { 22 },<br>fixed-dimension { 0 }, fixed-dimension { 0 }, fixed-dimension { 0 }<br>)                                                                                                                                                                                                          |
+| Minor Interval Dimensions | SEQ (<br>fixed-dimension { 100 }, fixed-dimension { 35 }, fixed-dimension { 35 },<br>fixed-dimension { 0 }, fixed-dimension { 70 }<br>)                                                                                                                                                                                                                               |
+| Grid Lines                |                                                                                                                                                                                                                                                                                                                                                                       |
+| Major Grid Lines          | SEQ (<br>{ SEQ ({ 4, }, { 4, }, { 4, }, { 4, }, { 4, }, ), },<br>{ SEQ ({ 2, }, { 2, }, { 2, }, { 2, }, { 2, }, ), },<br>{ SEQ ({ 1, invisible, }, { 1, }, { 1, }, { 1, }, { 1, }, ), },<br>{ SEQ ({ 4, }, { 4, }, { 4, }, { 4, }, { 4, }, ), },<br>{ SEQ ({ 4, }, { 4, }, { 4, }, { 4, }, { 4, }, ), },<br>{ SEQ ({ 4, }, { 4, }, { 4, }, { 4, }, { 4, }, ), },<br>) |
+| Minor Grid Lines          | SEQ (<br>{ SEQ ({ 4, }, { 4, }, { 4, }, { 4, }, { 4, }, { 4, }, ), },<br>{ SEQ ({ 2, }, { 2, }, { 2, }, { 2, }, { 2, }, { 2, }, ), },<br>{ SEQ ({ 1, dashed, }, { 1, dashed, }, { 1, dashed, },<br>{ 1, dashed, }, { 1, dashed, }, { 1, dashed, }, ), },<br>)                                                                                                         |
+
+```
+
+{ SEQ ({ 2, , }, { 2, , }, { 2, , }, { 2, , }, { 2, , }, { 2, , }, ), },
+{ SEQ ({ 2, , }, { 2, , }, { 2, , }, { 2, , }, { 2, , }, { 2, , }, ), },
+{ SEQ ({ 4, , }, { 4, , }, { 4, , }, { 4, , }, { 4, , }, { 4, , }, ), },
+)
+
+```
+
+```
+
+Object Type      frame
+Object Identifier 1 0 0 0
+Object Class      0 0 0 0
+Subordinates      0
+Position          HP = 138, VP = 38
+Dimension         HD = 19, VD = 12
+
+```
+
+```
+
+Object Type      frame
+Object Identifier 1 0 0 1
+Object Class      0 0 0 0
+Subordinates      0
+Position          HP = 173, VP = 38
+Dimension         HD = 19, VD = 12
+
+```
+
+```
+
+Object Type      frame
+Object Identifier 1 0 0 2
+Object Class      0 0 0 1
+Subordinates      0
+Position          HP = 35, VP = 60
+Dimension         HD = 19, VD = 12
+
+```
+
+```
+
+Object Type      frame
+Object Identifier 1 0 0 3
+Object Class      0 0 0 2
+Subordinates      0
+Position          HP = 135, VP = 60
+Dimension         HD = 25, VD = 12
+
+```
+
+```
+
+Object Type      frame
+Object Identifier 1 0 0 4
+Object Class      0 0 0 2
+Subordinates      0
+Position          HP = 186, VP = 60
+Dimension         HD = 9, VD = 12
+
+```
+
+```
+
+Object Type      frame
+Object Identifier 1 0 0 5
+Object Class      0 0 0 1
+Subordinates      0
+Position          HP = 35, VP = 82
+Dimension         HD = 17, VD = 12
+
+```
+
+```
+
+Object Type      frame
+Object Identifier 1 0 0 6
+Object Class      0 0 0 2
+Subordinates      0
+Position          HP = 151, VP = 82
+Dimension         HD = 9, VD = 12
+
+```
+
+```
+
+Object Type      frame
+Object Identifier 1 0 0 7
+Object Class      0 0 0 2
+Subordinates      0
+Position          HP = 182, VP = 60
+Dimension         HD = 13, VD = 12
+
+```
+
+```
+
+Object Type      block
+Object Identifier 1 0 0 0 0
+Dimension        HD = 19, VD = 12
+Content Portions 0 ('XXX')
+
+```
+
+```
+
+Object Type      block
+Object Identifier 1 0 0 1 0
+Dimension        HD = 19, VD = 12
+Content Portions 0 ('YYY')
+
+```
+
+```
+
+Object Type      block
+Object Identifier 1 0 0 2 0
+
+```
+
+|                              |                  |
+|------------------------------|------------------|
+| Dimension                    | HD = 19, VD = 12 |
+| Content Portions             | 0 ('AAA')        |
+| Object Type                  | block            |
+| Object Identifier            | 1 0 0 3 0        |
+| Dimension                    | HD = 25, VD = 12 |
+| Content Portions             | 0 ('111111.')    |
+| Object Type                  | block            |
+| Object Identifier            | 1 0 0 4 0        |
+| Dimension                    | HD = 9, VD = 12  |
+| Content Portions             | 0 ('22.')        |
+| Object Type                  | block            |
+| Object Identifier            | 1 0 0 5 0        |
+| Dimension                    | HD = 17, VD = 12 |
+| Content Portions             | 0 ('BBB')        |
+| Object Type                  | block            |
+| Object Identifier            | 1 0 0 6 0        |
+| Dimension                    | HD = 9, VD = 12  |
+| Content Portions             | 0 ('33.')        |
+| Object Type                  | block            |
+| Object Identifier            | 1 0 0 7 0        |
+| Dimension                    | HD = 13, VD = 12 |
+| Content Portions             | 0 ('444.')       |
+| Content Identifier - Logical | 3 0 0 0 0        |
+| Content Identifier - Layout  | 1 0 0 0 0 0      |
+| Content Information          | "XXX"            |
+| Content Identifier - Logical | 3 0 0 1 0        |
+| Content Identifier - Layout  | 1 0 0 1 0 0      |
+| Content Information          | "YYY"            |
+| Content Identifier - Logical | 3 0 1 0 0        |
+| Content Identifier - Layout  | 1 0 0 2 0 0      |
+| Content Information          | "AAA"            |
+| Content Identifier - Logical | 3 0 1 1 0        |
+| Content Identifier - Layout  | 1 0 0 3 0 0      |
+| Content Information          | "111111."        |
+| Content Identifier - Logical | 3 0 1 2 0        |
+| Content Identifier - Layout  | 1 0 0 4 0 0      |
+| Content Information          | "22."            |
+| Content Identifier - Logical | 3 0 2 0 0        |
+| Content Identifier - Layout  | 1 0 0 5 0 0      |
+| Content Information          | "BBB"            |
+| Content Identifier - Logical | 3 0 2 1 0        |
+| Content Identifier - Layout  | 1 0 0 6 0 0      |
+| Content Information          | "33."            |
+| Content Identifier - Logical | 3 0 2 2 0        |
+| Content Identifier - Layout  | 1 0 0 7 0 0      |
+| Content Information          | "444."           |
+
+![](af3b2fa532cb9b02a2aaeeb49e0118d0_img.jpg)
+
+Specific Logical Structure
+
+```
+
+  graph TD
+    3[3 document logical root] --> 30[30 table root]
+    30 --> 300[300 box heading row]
+    30 --> 301[301 2nd row]
+    30 --> 302[302 3rd row]
+    
+    300 --> 3000[3000]
+    300 --> 3001[3001]
+    3000 --> XXX['XXX']
+    3001 --> YYY['YYY']
+    XXX --> 10000[10000]
+    YYY --> 10010[10010]
+    10000 --> 1000[1000]
+    10010 --> 1001[1001]
+
+    301 --> 3010[3010]
+    301 --> 3011[3011]
+    301 --> 3012[3012]
+    3010 --> AAA['AAA']
+    3011 --> 111111['111111.']
+    3012 --> 22['22.']
+    AAA --> 10020[10020]
+    111111 --> 10030[10030]
+    22 --> 10040[10040]
+    10020 --> 1002[1002]
+    10030 --> 1003[1003]
+    10040 --> 1004[1004]
+
+    302 --> 3020[3020]
+    302 --> 3021[3021]
+    302 --> 3022[3022]
+    3020 --> BBB['BBB']
+    3021 --> 33['33.']
+    3022 --> 444['444.']
+    BBB --> 10050[10050]
+    33 --> 10060[10060]
+    444 --> 10070[10070]
+    10050 --> 1005[1005]
+    10060 --> 1006[1006]
+    10070 --> 1007[1007]
+
+    1000 & 1001 & 1002 & 1003 & 1004 & 1005 & 1006 & 1007 --> 100[100 1st table frame]
+    100 --> 10[10 1st page]
+    10 --> 1[1 document layout root]
+  
+```
+
+Specific Logical Structure
+
+TISO5300-95/d27
+
+Figure B.4 – Specific Structures of Example 2
+
+### B.2.4 Explanation
+
+Figure B.5 depicts the image of tabular layout that the layout process generates by applying the generic layout structure (see B.1.1) to the logical structures (see B.2.1 and B.2.2).
+
+![A diagram of a formatted table layout with dimensions. The table is enclosed in a grid frame of 270x90 units. It shows internal cells with content 'XXX', 'YYY', 'AAA', '111111.', '22.', 'BBB', '33.', and '444.', each associated with a numeric ID (1000-1007). Horizontal dimensions are 15, 15, 100, 35, 35, 70, 15, 15. Vertical dimensions are 15, 40, 22, 22, 15.](aed5b156b9b0fff9167baba88e5fdcfc_img.jpg)
+
+grid frame (1 0 0)
+
+|                                                     |                            |                         |
+|-----------------------------------------------------|----------------------------|-------------------------|
+| <p>1002</p> <p>AAA</p> <hr/> <p>1005</p> <p>BBB</p> | <p>1000</p> <p>XXX</p>     | <p>1001</p> <p>YYY</p>  |
+|                                                     | <p>1003</p> <p>111111.</p> | <p>1004</p> <p>22.</p>  |
+|                                                     | <p>1006</p> <p>33.</p>     | <p>1007</p> <p>444.</p> |
+
+Legend:  
+entry frame  
+border
+
+TISO5310-95/d28
+
+A diagram of a formatted table layout with dimensions. The table is enclosed in a grid frame of 270x90 units. It shows internal cells with content 'XXX', 'YYY', 'AAA', '111111.', '22.', 'BBB', '33.', and '444.', each associated with a numeric ID (1000-1007). Horizontal dimensions are 15, 15, 100, 35, 35, 70, 15, 15. Vertical dimensions are 15, 40, 22, 22, 15.
+
+Figure B.5 – Formatted Table of Example 2
+
+**B.2.4.1 Determination of column widths**
+
+The grid frame 1 0 0 is referred to by the grid logical object 3 0 by means of the attribute “grid frame classes” specified for the grid logical object class 2 0 (see 9.2).
+
+Therefore, the layout grid within the grid frame 1 0 0 has the same number of minor grid intervals as the minor size of the logical grid associated with the grid logical object 3 0. The value specified by the parameter “minor size” of the attribute “grid description” applied to this grid logical object is 5, and the layout grid contains 5 columns.
+
+The parameter “minor interval dimensions” applies to the grid frame class 0 0 0 with the value:
+
+```
+SEQ (
+    fixed-dimension { 100 },
+    OPTREP ( proportional { group = 1, im-dim = 1, default = 0 } ),
+    proportional { group = 1, im-dim = 2, }
+)
+```
+
+This parameter specifies the minor grid interval dimensions, namely the widths of the columns within the layout grid. Since the layout grid has 5 minor grid intervals, the grid interval expression specified for the parameter “minor interval dimensions” shall evaluate to a sequence of 5 interval indicators, each of which specifies a rule to determine the dimension of each individual minor grid interval (see 11.4). The sequence to be derived from the expression is:
+
+```
+fixed-dimension{100}
+proportional {group = 1, im-dim = 1, default = 0}
+proportional {group = 1, im-dim = 1, default = 0}
+proportional {group = 1, im-dim = 1, default = 0}
+proportional {group = 1, im-dim = 2,}
+```
+
+The *i*-th interval indicator in the sequence is used to determine the *i*-th minor grid interval dimension.
+
+- the width of the 1st column shall be fixed to be 100 SMU;
+- the 2nd to 5th column widths shall be variable and proportional to one another;
+- each of the 2nd to 4th column widths shall be the default width 0, if no content is laid out within this column;
+- whenever two of the 2nd to 4th column widths are positive, they shall be the same;
+- the 5th column shall be always twice as wide as the positive width of any of the 2nd to 4th columns.
+
+Actually, in Figure B.5, the 2nd and 3rd columns have the same width 35 SMU, which is determined by the horizontal dimension of the image of the text ‘11111.’ and the gutter space widths around the 1st and 2nd minor grid lines.
+
+Since no content is laid out within the 4th column, the default width 0 is applied to the 4th column width. Hence, the 4th column degenerates, and the table looks as if it had only 4 columns.
+
+In contrast with the 4th column, although no content is laid out within the 5th column either, the 5th column is twice as wide as the 2nd and 3rd column: without a default width specified for a proportionally determined grid interval dimension, the grid interval dimension is always determined so as to keep the specified proportion to other grid interval dimensions.
+
+**B.2.4.2 Determination of imaging factors of vertical lines**
+
+The parameter “minor grid lines” is specified for the layout object class 0 0 0 with the value:
+
+```
+SEQ (
+    { OPTREP ( { 4, solid, black } ), precedence = 5 },
+    { OPTREP ( { 2, solid, black } ), precedence = 4 },
+    OPTREP ( { OPTREP ( { 1, dashed, black } ), precedence = 0 } ),
+    { OPTREP ( { 1, solid, black } ), precedence = 1 },
+    { OPTREP ( { 4, solid, black } ), precedence = 5 }
+)
+```
+
+This parameter shall be used to determine the imaging factors of the minor grid lines (vertical lines) forming part of the layout grid. Since the minor size of the layout grid is 5, it contains 6 minor layout grid lines (vertical lines). Hence, the above grid line expression specified for the attribute “minor grid lines” shall evaluate to a sequence of 6 line characteristic expressions. The derived sequence is:
+
+```
+OPTREP ({4, solid, black})
+OPTREP ({2, solid, black})
+OPTREP ({1, dashed, black})
+OPTREP ({1, dashed, black})
+OPTREP ({1, solid, black})
+OPTREP ({4, solid, black})
+```
+
+These line characteristic expressions in the sequence are sequentially applied to the minor grid lines.
+
+To the 0th minor layout grid line (the left edge of the table), for example, the line characteristic expression OPTREP ({4, solid, black}) is applied. Since the major size of the layout grid is 6, the layout grid line is divided into 6 grid line segments. Hence, this line characteristic expression evaluates to the sequence of 6 line segment characteristics:
+
+**{4, solid, black}, {4, solid, black}, {4, solid, black}, {4, solid, black}, {4, solid, black}, {4, solid, black}**
+
+The *i*-th line segment characteristic is applied to the *i*-th grid line segment of the grid line. In this case, since the line segment characteristics involved in the sequence are all the same ({4, solid, black}), the grid line is imaged with the wide solid line (4 SMU wide).
+
+In the same way, OPTREP ({2, solid, black}), OPTREP ({1, dashed, black}), OPTREP ({1, dashed, black}), OPTREP ({1, solid, black}) and OPTREP ({4, solid, black}) are respectively applied to the 1st to 5th minor grid lines.
+
+Since the dimension of the 4th minor grid interval is 0, the vertical lines with which the grid interval is edged, namely the 3rd and 4th minor grid line, merge into a single line. Therefore, two line characteristic expressions OPTREP ({1, dashed, black}) and OPTREP ({1, solid, black}) are applicable to this single line: the former specifies that the line shall be imaged with the narrow dashed line, while the latter does that the line shall be imaged with the narrow solid line.
+
+The layout process takes account of the precedence associated with each line characteristic expression: the line characteristic expression associated with higher precedence shall precede the other. In this case, the expression for the dashed line is associated with precedence 0, whilst the expression for the solid line is associated with precedence 1. Consequently, the line characteristic expression OPTREP ({1, solid, black}) takes precedence over the expression OPTREP ({1, dashed, black}), and therefore the line is imaged with the solid line (see 11.8).
+
+#### B.2.4.3 Determination of heights of rows
+
+Since the major size of the logical grid is specified as 6, the layout grid contains 6 major grid intervals. The parameter “major interval dimensions” specifies the dimensions of those grid intervals, namely the heights of the rows. In the same way as in determining the minor grid interval dimensions, the layout process evaluates the grid interval expression.
+
+```
+SEQ (
+    rule-b {minimum = 30, },
+    OPTREP ( proportional {group = 0, im-dim = 1, default = 0} )
+)
+```
+
+to the sequence of 6 entries:
+
+```
+rule-b {minimum = 40, }
+proportional {group = 0, im-dim = 1, default = 0}
+proportional {group = 0, im-dim = 1, default = 0}
+proportional {group = 0, im-dim = 1, default = 0}
+proportional {group = 0, im-dim = 1, default = 0}
+proportional {group = 0, im-dim = 1, default = 0}
+```
+
+The *i*-th interval indicator in the sequence is used to determine the *i*-th major grid interval dimension:
+
+- the height of the 1st row shall be determined in accordance with the rule B under the condition that it cannot be smaller than 40 SMU;
+- the 2nd to 6th row heights shall be variable and proportional to one another;
+- each of those row heights shall be the default height 0, if no content is laid out within this row;
+- whenever two of those row heights are positive, they shall be the same.
+
+Actually, in Figure B.5, the 2nd and 3rd rows have the same height 22 SMU. Since the dimensions of the 4th to 6th major grid intervals are determined to 0, the corresponding rows degenerate, and the table looks as if it had only 3 rows.
+
+#### B.2.4.4 Determination of imaging factors of horizontal lines
+
+Since the layout grid includes 7 major grid lines, the value of the parameter “major grid lines” evaluates to the sequence of 7 line characteristic expressions:
+
+```
+OPTREP ({4, solid, black})
+OPTREP ({2, solid, black})
+SEQ ({1, invisible, black}, OPTREP ({1, solid, black}))
+SEQ ({1, invisible, black}, OPTREP ({1, solid, black}))
+SEQ ({1, invisible, black}, OPTREP ({1, solid, black}))
+SEQ ({1, invisible, black}, OPTREP ({1, solid, black}))
+OPTREP ({4, solid, black})
+```
+
+These line characteristic expressions in the sequence are sequentially applied to the major grid lines in the layout grid.
+
+For example, the line characteristic expression SEQ ({1, invisible, black}, OPTREP ({1, solid, black})) applies to the 2nd major layout grid line. Since the minor size of the layout grid is 5, and therefore this layout grid line is divided into 5 line segments, the line characteristic expression evaluates to the sequence of 5 line segment characteristics:
+
+**{1, invisible, black}, {1, solid, black}, {1, solid, black}, {1, solid, black}, {1, solid, black}**
+
+NOTE – Because the 3rd and 4th minor grid lines merge into a single line, the 4th line segment on the major grid line degenerates into a point. Nevertheless, this degenerating line segment is counted as well.
+
+The line segment characteristic {1, invisible, black} applies to the 1st line segment of the 2nd major grid line, and the line segment is imaged invisible. The rest of the line segment of the grid line are all imaged with the narrow solid line, since the common line segment characteristic {1, solid, black} applies to them.
+
+The degeneration of the 4th to 6th rows causes the merge of 3rd to 6th major grid lines into a single line (the bottom edge of the table). Hence, the two line characteristic expressions SEQ ({1, invisible, black}, OPTREP ({1, solid, black})) and OPTREP ({4, solid, black}) are applicable to this single line. Since the former expression is associated with precedence 0 whilst the latter with precedence 5, this line is imaged with the wide solid line (4 SMU wide).
+
+#### B.2.4.5 Placement of entry frames within layout grid
+
+The content of an entry object is laid out within the layout grid rectangle which is the layout counterpart of the logical grid rectangle with which the entry object is associated.
+
+For example, the entry object 3 0 0 0 is associated with the logical grid rectangle edged with the 0th and 1st major grid lines, and the 1st and 2nd minor grid lines. This association is specified by the parameter “entry-location association” of the attribute “grid description” specified for the grid logical object 3 0: the parameter includes an entry of {locations = {(0, 1)}, entries = {0 0}}.
+
+Principally, the sub-parameter “locations” specifies the logical coordinates of two diagonally opposite vertices of a logical grid rectangle. However, if the logical grid rectangle is a grid location, the sub-parameter may include only the coordinates of the left-top vertex of the rectangle. Hence, locations = {(0, 1)}, for example, specifies the logical rectangle with a pair of diagonally opposite vertices (0, 1) and (1, 2).
+
+The sub-parameter “entries” identifies those entry objects to be associated with the logical grid rectangle identified by the sub-parameter “locations”. The value for the sub-parameter “entries” is a set of one or more sequences of non-negative integers. The object identifiers of the entry objects are obtained by appending each specified sequence of non-negative integers to the object identifier of the grid logical object for which the sub-parameter is specified. Hence, entries = {0 0}, for example, specifies the object identifier 3 0 0 0.
+
+The layout counterpart of the logical grid rectangle associated with the entry object 3 0 0 0 is the layout grid rectangle edged with the 0th and 1st major (horizontal) layout grid lines, and the 1st and 2nd minor (vertical) layout grid lines. The available area for the entry frame 1 0 0 0, within which the content associated with the entry object 3 0 0 0 is to be laid out, shall be calculated within this layout grid rectangle.
+
+The attribute “grid gutters” specified for the grid frame class 0 0 0 and the sub-parameter “offset” specified for the frame class 0 0 0 0 are taken into account when the layout process calculates this available area. The gutter space widths around the layout grid lines are specified as 10 SMU, and the offsets for the leading, trailing, left-hand and right-hand edges are all 0. Hence, the available area for the entry frame 1 0 0 0 is a rectangle within the layout grid rectangle whose distances from the bordering grid lines of the layout grid rectangle are 5 SMU (see Figure B.6).
+
+When the layout process positions the entry frame 1 0 0 0 within this available area, it further takes account of the following attributes and parameters:
+
+- “layout path” specified for the grid frame class 0 0 0;
+- “alignment” specified for the (entry) frame class 0 0 0 0.
+
+Since the layout path of the grid frame 1 0 0 is 270°, and further the fill order applied to the entry frame 1 0 0 0 is ‘reverse’ (specified for the frame class 0 0 0 0), the entry frame is positioned within the available area so that it shall be as close as possible to the 1st major layout grid line, which is the bottom edge of the rectangle (see Figure B.6).
+
+In horizontally positioning the entry frame 1 0 0 0, the parameter alignment applied to the entry frame is taken into account. Since the specified value is ‘centred’, the entry frame is positioned equidistant from the 1st and 2nd minor grid lines, which are respectively the left and right edges of the rectangle (see Figure B.6).
+
+![Diagram illustrating the placement of an entry frame within a grid rectangle. The diagram shows a grid with major and minor grid lines. The 0th layout major grid line is at the top, and the 1st layout major grid line is below it. The 1st layout minor grid line is on the left, and the 2nd layout minor grid line is on the right. The gutter between the 0th and 1st layout major grid lines is 10. The gutter between the 1st and 2nd layout minor grid lines is 10. The gutter between the 1st and 2nd layout major grid lines is 10. The available area for the frame 1 0 0 0 is shaded. The frame 1 0 0 0 is positioned within the available area, with its top edge aligned with the 0th layout major grid line and its left edge aligned with the 1st layout minor grid line. The frame 1 0 0 0 contains the text 'XXX'.](06b83e9b87612260a1221a69827ba169_img.jpg)
+
+Gutter = 10                      Gutter = 10
+
+0th layout major grid line
+
+1 0 0 0  
+XXX
+
+1st layout major grid line
+
+Gutter = 10
+
+TISO5320-95/d29
+
+1st layout minor grid line                      2nd layout minor grid line
+
+Available area for the frame 1 0 0 0
+
+Diagram illustrating the placement of an entry frame within a grid rectangle. The diagram shows a grid with major and minor grid lines. The 0th layout major grid line is at the top, and the 1st layout major grid line is below it. The 1st layout minor grid line is on the left, and the 2nd layout minor grid line is on the right. The gutter between the 0th and 1st layout major grid lines is 10. The gutter between the 1st and 2nd layout minor grid lines is 10. The gutter between the 1st and 2nd layout major grid lines is 10. The available area for the frame 1 0 0 0 is shaded. The frame 1 0 0 0 is positioned within the available area, with its top edge aligned with the 0th layout major grid line and its left edge aligned with the 1st layout minor grid line. The frame 1 0 0 0 contains the text 'XXX'.
+
+Figure B.6 – Placement of Entry Frame within grid Rectangle
+
+#### B.2.4.6 Placement of layout grid within grid frame
+
+The position of the layout grid itself within the grid frame is determined by the attribute “grid position” applied to the grid frame class 0 0 0.
+
+The parameter “variable position” specified for this attribute specifies that the layout grid is to be variably positioned.
+
+The sub-parameter “major alignment” of this parameter specifies the position of the layout grid in the direction orthogonal to the major path. Since the major path is vertically downward, the sub-parameter specifies the horizontal position of the layout grid. In this example, since the specified value to the sub-parameter is ‘centred’, the layout grid is placed horizontally centred.
+
+On the other hand, the sub-parameter “minor alignment” specifies the position of the layout grid in the direction orthogonal to the minor path, that is, in the vertical direction. Since this sub-parameter specifies the value ‘left-hand aligned’, the grid is positioned as close as possible to the top edge (trailing edge relative to the layout path) of the grid frame 1 0 0 as long as the entry frame does not fall within the border free space of the grid frame (see Figure B.5).
+
+### B.3 Example 3
+
+#### B.3.1 Generic Logical Structure
+
+This example uses the same generic logical structure as that defined in B.2.1.
+
+#### B.3.2 Specific Logical Structure
+
+The specific logical structure dealt with in this example is the extension of B.2.2.
+
+- Replace the object description 3 0 in B.2.2 with the following:
+
+|                          |                           |
+|--------------------------|---------------------------|
+| <b>Object Type</b>       | <b>grid logical</b>       |
+| <b>Object Identifier</b> | <b>3 0</b>                |
+| <b>Object Class</b>      | <b>2 0</b>                |
+| <b>Subordinates</b>      | <b>0, 1, 2, 3, 4</b>      |
+| <b>Grid Description</b>  | -- <i>style attribute</i> |
+| <b>Major Size</b>        | <b>6</b>                  |
+| <b>Minor Size</b>        | <b>5</b>                  |
+
+Entry Location Association      { locations = {(0, 1), }, entries = {0 0} },  
+                                          { locations = {(0, 2), }, entries = {0 1} },  
+                                          { locations = {(1, 0), }, entries = {1 0} },  
+                                          { locations = {(2, 0), }, entries = {2 0} },  
+                                          { locations = {(3, 0), }, entries = {3 0} },  
+                                          { locations = {(4, 0), }, entries = {4 0} },  
+                                          { locations = {(1, 1), }, entries = {1 1} },  
+                                          { locations = {(1, 2), }, entries = {1 2} },  
+                                          { locations = {(2, 1), }, entries = {2 1} },  
+                                          { locations = {(2, 2), }, entries = {2 2} },  
+                                          { locations = {(3, 1), }, entries = {3 1} },  
+                                          { locations = {(3, 2), }, entries = {3 2} },  
+                                          { locations = {(4, 1), }, entries = {4 1} },  
+                                          { locations = {(4, 2), }, entries = {4 2} }
+
+– Append the following descriptions to B.2.2:
+
+|                              |                   |
+|------------------------------|-------------------|
+| Object Type                  | composite logical |
+| Object Identifier            | 3 0 3 (4th row)   |
+| Object Class                 | 2 0 1             |
+| Object Type                  | basic logical     |
+| Object Identifier            | 3 0 3 0           |
+| Object Class                 | 2 0 1 0           |
+| Content Portions             | 0 ('CCC')         |
+| Object Type                  | basic logical     |
+| Object Identifier            | 3 0 3 1           |
+| Object Class                 | 2 0 1 1           |
+| Content Portions             | 0 ('555.')        |
+| Object Type                  | basic logical     |
+| Object Identifier            | 3 0 3 2           |
+| Object Class                 | 2 0 1 1           |
+| Content Portions             | 0 ('66.')         |
+| Object Type                  | composite logical |
+| Object Identifier            | 3 0 4 (5th row)   |
+| Object Class                 | 2 0 1             |
+| Object Type                  | basic logical     |
+| Object Identifier            | 3 0 4 0           |
+| Object Class                 | 2 0 1 0           |
+| Content Portions             | 0 ('DDD')         |
+| Object Type                  | basic logical     |
+| Object Identifier            | 3 0 4 1           |
+| Object Class                 | 2 0 1 1           |
+| Content Portions             | 0 ('7.')          |
+| Object Type                  | basic logical     |
+| Object Identifier            | 3 0 4 2           |
+| Object Class                 | 2 0 1 1           |
+| Content Portions             | 0 ('888.')        |
+| Content Identifier – Logical | 3 0 3 0 0         |
+| Content Information          | 'CCC'             |
+| Content Identifier – Logical | 3 0 3 1 0         |
+| Content Information          | '555.'            |
+| Content Identifier – Logical | 3 0 3 2 0         |
+| Content Information          | '66.'             |
+| Content Identifier – Logical | 3 0 4 0 0         |
+| Content Information          | 'DDD'             |
+| Content Identifier – Logical | 3 0 4 1 0         |
+| Content Information          | '7.'              |
+| Content Identifier – Logical | 3 0 4 2 0         |
+| Content Information          | '888.'            |
+
+### B.3.3 Specific Layout Structure
+
+This subclause provides a description of the specific layout structure that the layout process generates from the generic layout structure (see B.1.1) and the logical structures (see B.3.1 and B.3.2).
+
+The specific layout structure to be generated is the extension of the specific layout structure in B.2.3.
+
+- Replace the value to the attribute “subordinates” in the object description with the identifier 1 in B.2.3 with:
+
+**Subordinates** 0, 1
+
+- Append the following descriptions to B.2.3:
+
+|                                  |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
+|----------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| <b>Object Type</b>               | <b>page</b>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
+| <b>Object Identifier</b>         | <b>1 1</b>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
+| <b>Subordinates</b>              | <b>0</b>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
+| <b>Object Type</b>               | <b>grid frame</b>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
+| <b>Object Identifier</b>         | <b>1 1 0</b>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
+| <b>Subordinates</b>              | <b>0, 1, 2, 3, 4, 5, 6, 7</b>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
+| <b>Dimension</b>                 | <b>HD = 300, VD = 120</b>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
+| <b>Grid Position</b>             |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
+| <b>Fixed Position</b>            |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
+| <b>Major Position</b>            | <b>15</b>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
+| <b>Minor Position</b>            | <b>42</b>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
+| <b>Grid Interval Dimensions</b>  |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
+| <b>Major Interval Dimensions</b> | <b>SEQ (</b><br><b>fixed-dimension {40}, fixed-dimension {0}, fixed-dimension {0} ,</b><br><b>fixed-dimension {22}, fixed-dimension {22}, fixed-dimension {0}</b><br><b>)</b>                                                                                                                                                                                                                                                                                                                                                         |
+| <b>Minor Interval Dimensions</b> | <b>SEQ (</b><br><b>fixed-dimension {100}, fixed-dimension {29}, fixed-dimension {29},</b><br><b>fixed-dimension { 0}, fixed-dimension {58}</b><br><b>)</b>                                                                                                                                                                                                                                                                                                                                                                            |
+| <b>Grid Lines</b>                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
+| <b>Major Grid Lines</b>          | <b>SEQ (</b><br><b>{ SEQ ({ 4, , }, {4, , }, {4, , }, {4, , }, {4, , }, ),</b><br><b>{ SEQ ({ 2, , }, {2, , }, {2, , }, {2, , }, {2, , }, ),</b><br><b>{ SEQ ({ 1, invisible, }, {1, , }, {1, , }, {1, , }, {1, , }, ),</b><br><b>{ SEQ ({ 4, , }, {4, , }, {4, , }, {4, , }, {4, , }, ),</b><br><b>{ SEQ ({ 4, , }, {4, , }, {4, , }, {4, , }, {4, , }, ),</b><br><b>{ SEQ ({ 4, , }, {4, , }, {4, , }, {4, , }, {4, , }, )</b><br><b>)</b>                                                                                          |
+| <b>Minor Grid Lines</b>          | <b>SEQ (</b><br><b>{ SEQ ({ 4, , }, {4, , }, {4, , }, {4, , }, {4, , }, {4, , }, ),</b><br><b>{ SEQ ({ 2, , }, {2, , }, {2, , }, {2, , }, {2, , }, {2, , }, ),</b><br><b>{ SEQ ({1, dashed, }, {1, dashed, }, {1, dashed, }, {1, dashed, },</b><br><b>{1, dashed, }, {1, dashed, },),</b><br><b>{ SEQ ({ 2, , }, {2, , }, {2, , }, {2, , }, {2, , }, {2, , }, ),</b><br><b>{ SEQ ({ 2, , }, {2, , }, {2, , }, {2, , }, {2, , }, {2, , }, ),</b><br><b>{ SEQ ({ 4, , }, {4, , }, {4, , }, {4, , }, {4, , }, {4, , }, )</b><br><b>)</b> |
+| <b>Object Type</b>               | <b>frame</b>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
+| <b>Object Identifier</b>         | <b>1 1 0 0</b>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
+| <b>Subordinates</b>              | <b>0</b>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
+| <b>Position</b>                  | <b>HP = 147, VP = 38</b>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
+| <b>Dimension</b>                 | <b>HD = 19, VD = 12</b>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
+| <b>Object Type</b>               | <b>frame</b>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
+| <b>Object Identifier</b>         | <b>1 1 0 1</b>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
+| <b>Subordinates</b>              | <b>0</b>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
+| <b>Position</b>                  | <b>HP = 176, VP = 38</b>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
+| <b>Dimension</b>                 | <b>HD = 19, VD = 12</b>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
+| <b>Object Type</b>               | <b>frame</b>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
+| <b>Object Identifier</b>         | <b>1 1 0 2</b>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
+| <b>Subordinates</b>              | <b>0</b>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
+| <b>Position</b>                  | <b>HP = 47, VP = 60</b>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
+| <b>Dimension</b>                 | <b>HD = 19, VD = 12</b>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
+| <b>Object Type</b>               | <b>frame</b>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
+| <b>Object Identifier</b>         | <b>1 1 0 3</b>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
+
+|                              |                    |
+|------------------------------|--------------------|
+| Subordinates                 | 0                  |
+| Position                     | HP = 153, VP = 60  |
+| Dimension                    | HD = 13, VD = 12   |
+| Object Type                  | frame              |
+| Object Identifier            | 1 1 0 4            |
+| Subordinates                 | 0                  |
+| Position                     | HP = 186, VP = 60  |
+| Dimension                    | HD = 9, VD = 12    |
+| Object Type                  | frame              |
+| Object Identifier            | 1 1 0 5            |
+| Subordinates                 | 0                  |
+| Position                     | HP = 47, VP = 82   |
+| Dimension                    | "HD = 19, VD = 12" |
+| Object Type                  | frame              |
+| Object Identifier            | 1 1 0 6            |
+| Subordinates                 | 0                  |
+| Position                     | HP = 161, VP = 82  |
+| Dimension                    | HD = 5, VD = 12    |
+| Object Type                  | frame              |
+| Object Identifier            | 1 1 0 7            |
+| Subordinates                 | 0                  |
+| Position                     | HP = 182, VP = 60  |
+| Dimension                    | HD = 13, VD = 12   |
+| Object Type                  | block              |
+| Object Identifier            | 1 1 0 0 0          |
+| Dimension                    | HD = 19, VD = 12   |
+| Content Portions             | 0 ('XXX')          |
+| Object Type                  | block              |
+| Object Identifier            | 1 1 0 1 0          |
+| Dimension                    | HD = 19, VD = 12   |
+| Content Portions             | 0 ('YYY')          |
+| Object Type                  | block              |
+| Object Identifier            | 1 1 0 2 0          |
+| Dimension                    | HD = 19, VD = 12   |
+| Content Portions             | 0 ('CCC')          |
+| Object Type                  | block              |
+| Object Identifier            | 1 1 0 3 0          |
+| Dimension                    | HD = 13, VD = 12   |
+| Content Portions             | 0 ('555.')         |
+| Object Type                  | block              |
+| Object Identifier            | 1 1 0 4 0          |
+| Dimension                    | HD = 9, VD = 12    |
+| Content Portions             | 0 ('66.')          |
+| Object Type                  | block              |
+| Object Identifier            | 1 1 0 5 0          |
+| Dimension                    | HD = 17, VD = 12   |
+| Content Portions             | 0 ('DDD')          |
+| Object Type                  | block              |
+| Object Identifier            | 1 1 0 6 0          |
+| Dimension                    | HD = 5, VD = 12    |
+| Content Portions             | 0 ('7.')           |
+| Object Type                  | block              |
+| Object Identifier            | 1 1 0 7 0          |
+| Dimension                    | HD = 13, VD = 12   |
+| Content Portions             | 0 ('888.')         |
+| Content Identifier – Layout  | 1 1 0 0 0 0        |
+| Content Information          | "XXX"              |
+| Content Identifier – Layout  | 1 1 0 1 0 0        |
+| Content Information          | "YYY"              |
+| Content Identifier – Logical | 3 0 3 0 0          |
+
+|                              |             |
+|------------------------------|-------------|
+| Content Identifier – Layout  | 1 1 0 2 0 0 |
+| Content Information          | "CCC"       |
+| Content Identifier – Logical | 3 0 3 1 0   |
+| Content Identifier – Layout  | 1 0 0 3 0 0 |
+| Content Information          | "555."      |
+| Content Identifier – Logical | 3 0 3 2 0   |
+| Content Identifier – Layout  | 1 1 0 4 0 0 |
+| Content Information          | "66."       |
+| Content Identifier – Logical | 3 0 4 0 0   |
+| Content Identifier – Layout  | 1 1 0 5 0 0 |
+| Content Information          | "DDD"       |
+| Content Identifier – Logical | 3 0 4 1 0   |
+| Content Identifier – Layout  | 1 1 0 6 0 0 |
+| Content Information          | "7."        |
+| Content Identifier – Logical | 3 0 4 2 0   |
+| Content Identifier – Layout  | 1 1 0 7 0 0 |
+| Content Information          | "888."      |
+
+### B.3.4 Explanation
+
+By modifying the specific logical structure B.2.2 as described in B.3.2, a new specific logical structures is defined. Figure B.7 depicts the image of tabular layout that the layout process generates from the extended specific logical structure.
+
+In this example, no room is left for any of the appended rows (4th and 5th rows) within the grid frame 1 0 0: only 6 SMU is left within the available area in the vertical direction (see Figure B.5); at least 22 SMU is necessary to lay out either of the 4th and 5th rows (see Figure B.7).
+
+Since the attribute “generator for subordinates” specified for the document layout root class is REP ( 0 0 ), and since the layout directive “grid frame classes” specified for the table root class 2 0 is REP ( 0 0 0 ), the content of the table may overflow into other grid frames.
+
+#### B.3.4.1 Repetitive layout of box headings
+
+At the occurrence of the overflow of the table content, the layout directive “obligatory same layout objects” specified for the row class 2 0 1 shall be taken into account.
+
+When the layout process commences to lay out the content of the 4th row object 3 0 3, it finds no room left within the grid frame 1 0 0. Then, the layout process generates a new page 1 1 and a new grid frame 1 1 0 within the page.
+
+Before laying out the content of the 4th row, the layout process evaluates the layout directive “obligatory same layout objects” which is specified for the row class 2 0 1, hence, applicable to the 4th row object 3 0 3.
+
+The value of the parameter “logical objects” of this attribute is used to identify a particular logical object called the *target object*. By definition, the target object is the nearest preceding logical object of the 4th row object 3 0 3 which belongs to the logical object class specified by this parameter. Since the value of this parameter is 2 0 0, the target object is the logical object 3 0 0.
+
+Then, the layout directive “obligatory same layout objects” specifies that any fragment of the content associated with the 4th row object shall be laid out with the entire content associated with the target object 3 0 0 within a single instance of the layout object class specified by the other parameter “layout objects”. Hence, if the content associated with the 4th row object is laid out within the grid frame 1 1 0, the layout directive requires that the content associated with the target object is also laid out within the same grid frame.
+
+The content of the target object 3 0 0 has been already laid out within the grid frame 1 0 0. Since the same instance of the layout directive “obligatory same layout objects” is applied to the 2nd and 3rd row objects (all row objects are instances of the common layout object class 2 0 1, and the layout directive is specified for the class description), canceling the layout of the target object within the grid frame 1 0 0 and re-laying them out within the grid frame 1 1 0 causes the violation of the constraint imposed by this layout directive.
+
+To avoid this contradiction, the definition of the layout directive “obligatory same layout objects” allows the layout process to duplicate the content of the target object and to lay out the generated reproduction within different layout objects. In this example, the layout process produces a complete reproduction of the content portions whose values for the attribute “content identifier – logical” are 3 0 0 0 0 and 3 0 0 1 0. The generated reproduction of the two content
+
+portions is respectively the content portions whose values for the attribute “content identifier – layout” are 1 1 0 0 0 0 and 1 1 0 1 0 0. This reproduction is characterized by its lack of “content identifier – logical”.
+
+![Diagram showing grid frames and table content overflow. The top part shows a 'grid frame (1 0 0)' containing a table with cells labeled 1000-1007. The bottom part shows a 'grid frame (1 1 0)' with dimensions, showing how content from the previous frame overflows into the new frame's grid intervals. A legend defines 'entry frame' and 'border'.](2d548db0b26b7bf33244320322d5ee2c_img.jpg)
+
+The diagram illustrates the overflow of table contents across grid frames. The top part shows a 'grid frame (1 0 0)' containing a table with cells labeled 1000-1007. The bottom part shows a 'grid frame (1 1 0)' with dimensions, showing how content from the previous frame overflows into the new frame's grid intervals. A legend defines 'entry frame' and 'border'.
+
+Legend:
+
+- entry frame
+- border
+
+Diagram showing grid frames and table content overflow. The top part shows a 'grid frame (1 0 0)' containing a table with cells labeled 1000-1007. The bottom part shows a 'grid frame (1 1 0)' with dimensions, showing how content from the previous frame overflows into the new frame's grid intervals. A legend defines 'entry frame' and 'border'.
+
+Figure B.7 – Overflow of Table Contents
+
+**B.3.4.2 Prevention of redundant space for already laid out rows**
+
+Since the content of the 2nd and 3rd rows has been already laid out within the grid frame 1 0 0, they shall not be laid out within the grid frame 1 1 0. As a consequence, no content is laid out within the 2nd and 3rd row of the layout grid within the grid frame 1 1 0, and therefore the 2nd and 3rd major grid interval dimensions are determined as the specified default value, namely 0. Thus, even when the content of the table overflow a single grid frame, the space for content which has been already laid out is not generated within another grid frame into which the contents overflow.
+
+**B.4 Example 4**
+
+**B.4.1 Generic Logical Structure**
+
+This example uses the same generic logical structure as that defined in B.3.1.
+
+### B.4.2 Specific Logical Structure
+
+The specific logical structure dealt with in this example is the extension of B.3.2.
+
+- Replace the object description 3 0 in B.3.2 with the following:
+
+|                                   |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
+|-----------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| <b>Object Type</b>                | <b>grid logical</b>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
+| <b>Object Identifier</b>          | <b>3 0</b>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
+| <b>Object Class</b>               | <b>2 0</b>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
+| <b>Subordinates</b>               | <b>0, 1, 2, 3, 4, 5</b>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
+| <b>Grid Description</b>           | <i>-- style attribute</i>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
+| <b>Major Size</b>                 | <b>6</b>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
+| <b>Minor Size</b>                 | <b>5</b>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
+| <b>Entry Location Association</b> | { locations = {(0, 1), }, entries = {0 0} },<br>{ locations = {(0, 2), }, entries = {0 1} },<br>{ locations = {(1, 0), }, entries = {1 0} },<br>{ locations = {(2, 0), }, entries = {2 0} },<br>{ locations = {(3, 0), }, entries = {3 0} },<br>{ locations = {(4, 0), }, entries = {4 0} },<br>{ locations = {(5, 0), }, entries = {5 0} },<br>{ locations = {(1, 1), }, entries = {1 1} },<br>{ locations = {(1, 2), }, entries = {1 2} },<br>{ locations = {(2, 1), }, entries = {2 1} },<br>{ locations = {(2, 2), }, entries = {2 2} },<br>{ locations = {(3, 1), }, entries = {3 1} },<br>{ locations = {(3, 2), }, entries = {3 2} },<br>{ locations = {(4, 1), }, entries = {4 1} },<br>{ locations = {(4, 2), }, entries = {4 2} },<br>{ locations = {(5, 2), }, entries = {5 1} } |
+
+- Append the following descriptions to B.3.2:
+
+|                                     |                                                        |
+|-------------------------------------|--------------------------------------------------------|
+| <b>Object Type</b>                  | <b>composite logical</b>                               |
+| <b>Object Identifier</b>            | <b>3 0 5 (6th row)</b>                                 |
+| <b>Object Class</b>                 | <b>2 0 1</b>                                           |
+| <b>Subordinates</b>                 | <b>0</b>                                               |
+| <b>Object Type</b>                  | <b>basic logical</b>                                   |
+| <b>Object Identifier</b>            | <b>3 0 5 0</b>                                         |
+| <b>Object Class</b>                 | <b>2 0 1 0</b>                                         |
+| <b>Content Portions</b>             | <b>0 ('EEE')</b>                                       |
+| <b>Object Type</b>                  | <b>composite logical</b>                               |
+| <b>Object Identifier</b>            | <b>3 0 5 1</b>                                         |
+| <b>Object Class</b>                 | <b>2 0 1 2</b>                                         |
+| <b>Subordinates</b>                 | <b>0, 1</b>                                            |
+| <b>Object Type</b>                  | <b>basic logical</b>                                   |
+| <b>Object Identifier</b>            | <b>3 0 5 1 0</b>                                       |
+| <b>Object Class</b>                 | <b>2 0 1 2 0</b>                                       |
+| <b>Content Portions</b>             | <b>0 (raster)</b>                                      |
+| <b>Object Type</b>                  | <b>basic logical</b>                                   |
+| <b>Object Identifier</b>            | <b>3 0 5 1 1</b>                                       |
+| <b>Object Class</b>                 | <b>2 0 1 2 1</b>                                       |
+| <b>Content Portions</b>             | <b>0 ('fff')</b>                                       |
+| <b>Content Identifier – Logical</b> | <b>3 0 5 0 0 0</b>                                     |
+| <b>Content Information</b>          | <b>"EEE"</b>                                           |
+| <b>Content Identifier – Logical</b> | <b>3 0 5 1 0 0</b>                                     |
+| <b>Content Information</b>          | <b>/* Array of raster-graphics content elements */</b> |
+| <b>Content Identifier – Logical</b> | <b>3 0 5 1 1 0</b>                                     |
+| <b>Content Information</b>          | <b>"fff"</b>                                           |
+
+### B.4.3 Explanation
+
+Figure B.8 depicts an image of a table with an entry of raster contents.
+
+The composite logical object 3 0 5 0 is an entry object occupying the logical grid rectangle whose vertices are (5, 2), (5, 3), (6, 3) and (6, 2). The content associated with this entry object is laid out within the entry frame 1 2 0 3, which is
+
+an instance of the frame class 0 0 0 3. Since the entry object is superior to two basic logical objects, the entry frame 1 2 0 3 contains two blocks: one is for the figure; the other is for the caption.
+
+![Diagram of a grid frame (1 2 0) showing a 2x2 table structure. The table is enclosed in a solid border. The top-left cell is empty. The top-right cell contains two entry frames: 1200 with 'XXX' and 1201 with 'YYY'. The bottom-left cell contains an entry frame 1202 with 'EEE'. The bottom-right cell contains an entry frame 1203 with a figure of a triangle and the label 'fff'. A dashed border surrounds the entire grid. A legend below shows: a solid rectangle for 'block', a dashed rectangle for 'entry frame', and a dash-dot rectangle for 'border'. The reference TISO5340-95/d31 is at the bottom right.](2c41e286ea9a1b008d3beb348d86096f_img.jpg)
+
+grid frame (1 2 0)
+
+Legend:
+
+- block
+- entry frame
+- border
+
+TISO5340-95/d31
+
+Diagram of a grid frame (1 2 0) showing a 2x2 table structure. The table is enclosed in a solid border. The top-left cell is empty. The top-right cell contains two entry frames: 1200 with 'XXX' and 1201 with 'YYY'. The bottom-left cell contains an entry frame 1202 with 'EEE'. The bottom-right cell contains an entry frame 1203 with a figure of a triangle and the label 'fff'. A dashed border surrounds the entire grid. A legend below shows: a solid rectangle for 'block', a dashed rectangle for 'entry frame', and a dash-dot rectangle for 'border'. The reference TISO5340-95/d31 is at the bottom right.
+
+Figure B.8 – Table with Raster Contents
+
+## B.5 Example 5
+
+### B.5.1 Generic Logical Structure
+
+|                            |                                        |
+|----------------------------|----------------------------------------|
+| Object Type                | document logical root                  |
+| Object Class Identifier    | 2                                      |
+| Generator for Subordinates | REQ ( 2 0 )                            |
+| Object Type                | grid logical (table root)              |
+| Object Class Identifier    | 2 0                                    |
+| Generator for Subordinates | SEQ ( 2 0 0, 2 0 1, OPTREP ( 2 0 2 ) ) |
+| Layout Style               | 4 0                                    |
+| Object Type                | basic logical (table title)            |
+| Object Class Identifier    | 2 0 0                                  |
+| Layout Style               | 4 1                                    |
+| Object Type                | composite logical (attribute group)    |
+| Object Class Identifier    | 2 0 1                                  |
+| Generator for Subordinates | OPTREP ( 2 0 1 0 )                     |
+| Layout Style               | 4 2                                    |
+| Object Type                | basic logical (attribute)              |
+| Object Class Identifier    | 2 0 1 0                                |
+| Layout Style               | 4 3                                    |
+| Object Type                | composite logical (subtable)           |
+| Object Class Identifier    | 2 0 2                                  |
+| Generator for Subordinates | SEQ ( 2 0 2 0, OPTREP ( 2 0 2 1 ) )    |
+| Layout Style               | 4 4                                    |
+| Object Type                | basic logical (subtable title)         |
+| Object Class Identifier    | 2 0 2 0                                |
+| Layout Style               | 4 5                                    |
+| Object Type                | composite logical (tuple)              |
+| Object Class Identifier    | 2 0 2 1                                |
+
+|                            |                                        |
+|----------------------------|----------------------------------------|
+| Generator for Subordinates | SEQ ( 2 0 2 1 0, OPTREP ( 2 0 2 1 1 )) |
+| Layout Style               | 4 6                                    |
+| Object Type                | basic logical (index)                  |
+| Object Class Identifier    | 2 0 2 1 0                              |
+| Layout Style               | 4 7                                    |
+| Object Type                | basic logical (value)                  |
+| Object Class Identifier    | 2 0 2 1 1                              |
+| Layout Style               | 4 8                                    |
+
+![Figure B.9 – Generic Logical Structure of Example 5. A hierarchical tree diagram showing the logical structure of a document. The root node is '2' (document logical root). It has a child '20' (grid logical (table root)). '20' has three children: '200' (table title), '201' (attribute group), and '202' (subtable). '201' has a child '2010' (attribute). '202' has a child '2020' (subtable title) and a child '2021' (tuple). '2021' has two children: '20210' (index) and '20211' (value). The diagram also includes labels 'OPTREP' at various levels.](ae57a92114d2bd84ef81129e7fbdd89d_img.jpg)
+
+```
+
+graph TD
+    2[2] --> 20[20]
+    20 --> 200[200]
+    20 --> 201[201]
+    20 --> 202[202]
+    200 --- title[table title]
+    201 --- ag[attribute group]
+    202 --- subtable[subtable]
+    201 -- OPTREP --> 2010[2010]
+    2010 --- attr[attribute]
+    202 -- OPTREP --> 2020[2020]
+    202 -- OPTREP --> 2021[2021]
+    2020 --- sttitle[subtable title]
+    2021 --- tuple[tuple]
+    2021 -- OPTREP --> 20210[20210]
+    2021 -- OPTREP --> 20211[20211]
+    20210 --- index[index]
+    20211 --- value[value]
+  
+```
+
+TISO5350-95/d32
+
+Figure B.9 – Generic Logical Structure of Example 5. A hierarchical tree diagram showing the logical structure of a document. The root node is '2' (document logical root). It has a child '20' (grid logical (table root)). '20' has three children: '200' (table title), '201' (attribute group), and '202' (subtable). '201' has a child '2010' (attribute). '202' has a child '2020' (subtable title) and a child '2021' (tuple). '2021' has two children: '20210' (index) and '20211' (value). The diagram also includes labels 'OPTREP' at various levels.
+
+Figure B.9 – Generic Logical Structure of Example 5
+
+## B.5.2 Specific Logical Structure
+
+|                   |                       |
+|-------------------|-----------------------|
+| Object Type       | document logical root |
+| Object Identifier | 3                     |
+| Object Class      | 2                     |
+| Subordinates      | 0                     |
+| Object Type       | grid logical          |
+| Object Identifier | 3 0                   |
+| Object Class      | 2 0                   |
+| Subordinates      | 0, 1, 2, 3            |
+| Layout Style      | 4 10                  |
+| Object Type       | basic logical         |
+| Object Identifier | 3 0 0                 |
+| Object Class      | 2 0 0                 |
+| Content Portions  | 0 ('% of Vote')       |
+| Object Type       | composite logical     |
+| Object Identifier | 3 0 1                 |
+| Object Class      | 2 0 1                 |
+| Subordinates      | 0, 1, 2               |
+| Object Type       | basic logical         |
+| Object Identifier | 3 0 1 0               |
+| Object Class      | 2 0 1 0               |
+| Content Portions  | 0 ('1952')            |
+| Object Type       | basic logical         |
+| Object Identifier | 3 0 1 1               |
+| Object Class      | 2 0 1 0               |
+| Content Portions  | 0 ('1957')            |
+| Object Type       | basic logical         |
+| Object Identifier | 3 0 1 2               |
+| Object Class      | 2 0 1 0               |
+
+|                   |                   |
+|-------------------|-------------------|
+| Content Portions  | 0 ('1962')        |
+| Object Type       | composite logical |
+| Object Identifier | 3 0 2             |
+| Object Class      | 2 0 2             |
+| Subordinates      | 0, 1, 2, 3, 4, 5  |
+| Object Type       | basic logical     |
+| Object Identifier | 3 0 2 0           |
+| Object Class      | 2 0 2 0           |
+| Content Portions  | 0 ('Parliament')  |
+| Object Type       | composite logical |
+| Object Identifier | 3 0 2 1           |
+| Object Class      | 2 0 2 1           |
+| Subordinates      | 0, 1, 2, 3        |
+| Object Type       | basic logical     |
+| Object Identifier | 3 0 2 1 0         |
+| Object Class      | 2 0 2 1 0         |
+| Content Portions  | 0 ('Belgaum')     |
+| Object Type       | basic logical     |
+| Object Identifier | 3 0 2 1 1         |
+| Object Class      | 2 0 2 1 1         |
+| Content Portions  | 0 ('55.6')        |
+| Object Type       | basic logical     |
+| Object Identifier | 3 0 2 1 2         |
+| Object Class      | 2 0 2 1 1         |
+| Content Portions  | 0 ('50.3')        |
+| Object Type       | basic logical     |
+| Object Identifier | 3 0 2 1 3         |
+| Object Class      | 2 0 2 1 1         |
+| Content Portions  | 0 ('56.7')        |
+| Object Type       | composite logical |
+| Object Identifier | 3 0 2 2           |
+| Object Class      | 2 0 2 1           |
+| Subordinates      | 0, 1, 2, 3        |
+| Object Type       | basic logical     |
+| Object Identifier | 3 0 2 2 0         |
+| Object Class      | 2 0 2 1 0         |
+| Content Portions  | 0 ('Calcutta')    |
+| Object Type       | basic logical     |
+| Object Identifier | 3 0 2 2 1         |
+| Object Class      | 2 0 2 1 1         |
+| Content Portions  | 0 ('36.8')        |
+| Object Type       | basic logical     |
+| Object Identifier | 3 0 2 2 2         |
+| Object Class      | 2 0 2 1 1         |
+| Content Portions  | 0 ('40.3')        |
+| Object Type       | basic logical     |
+| Object Identifier | 3 0 2 2 3         |
+| Object Class      | 2 0 2 1 1         |
+| Content Portions  | 0 ('46.3')        |
+| Object Type       | composite logical |
+| Object Identifier | 3 0 2 3           |
+| Object Class      | 2 0 2 1           |
+| Subordinates      | 0, 1, 2, 3        |
+| Object Type       | basic logical     |
+| Object Identifier | 3 0 2 3 0         |
+| Object Class      | 2 0 2 1 0         |
+| Content Portions  | 0 ('Gunter')      |
+| Object Type       | basic logical     |
+| Object Identifier | 3 0 2 3 1         |
+| Object Class      | 2 0 2 1 1         |
+| Content Portions  | 0 ('31.6')        |
+
+|                   |                            |
+|-------------------|----------------------------|
+| Object Type       | basic logical              |
+| Object Identifier | 3 0 2 3 2                  |
+| Object Class      | 2 0 2 1 1                  |
+| Content Portions  | 0 ('56.5')                 |
+| Object Type       | basic logical              |
+| Object Identifier | 3 0 2 3 3                  |
+| Object Class      | 2 0 2 1 1                  |
+| Content Portions  | 0 ('43.5')                 |
+| Object Type       | composite logical          |
+| Object Identifier | 3 0 2 4                    |
+| Object Class      | 2 0 2 1                    |
+| Subordinates      | 0, 1, 2, 3                 |
+| Object Type       | basic logical              |
+| Object Identifier | 3 0 2 4 0                  |
+| Object Class      | 2 0 2 1 0                  |
+| Content Portions  | 0 ('Kaira')                |
+| Object Type       | basic logical              |
+| Object Identifier | 3 0 2 4 1                  |
+| Object Class      | 2 0 2 1 1                  |
+| Content Portions  | 0 ('61.1')                 |
+| Object Type       | basic logical              |
+| Object Identifier | 3 0 2 4 2                  |
+| Object Class      | 2 0 2 1 1                  |
+| Content Portions  | 0 ('50.6')                 |
+| Object Type       | basic logical              |
+| Object Identifier | 3 0 2 4 3                  |
+| Object Class      | 2 0 2 1 1                  |
+| Content Portions  | 0 ('45.6')                 |
+| Object Type       | composite logical          |
+| Object Identifier | 3 0 2 5                    |
+| Object Class      | 2 0 2 1                    |
+| Subordinates      | 0, 1, 2, 3                 |
+| Object Type       | basic logical              |
+| Object Identifier | 3 0 2 5 0                  |
+| Object Class      | 2 0 2 1 0                  |
+| Content Portions  | 0 ('Madurai')              |
+| Object Type       | basic logical              |
+| Object Identifier | 3 0 2 5 1                  |
+| Object Class      | 2 0 2 1 1                  |
+| Content Portions  | 0 ('52.6')                 |
+| Object Type       | basic logical              |
+| Object Identifier | 3 0 2 1 2                  |
+| Object Class      | 2 0 2 1 1                  |
+| Content Portions  | 0 ('34.5')                 |
+| Object Type       | basic logical              |
+| Object Identifier | 3 0 2 1 3                  |
+| Object Class      | 2 0 2 1 1                  |
+| Content Portions  | 0 ('39.6')                 |
+| Object Type       | composite logical          |
+| Object Identifier | 3 0 3                      |
+| Object Class      | 2 0 2                      |
+| Subordinates      | 0, 1, 2, 3, 4, 5           |
+| Object Type       | basic logical              |
+| Object Identifier | 3 0 3 0                    |
+| Object Class      | 2 0 2 0                    |
+| Content Portions  | 0 ('Legislative Assembly') |
+| Object Type       | composite logical          |
+| Object Identifier | 3 0 3 1                    |
+| Object Class      | 2 0 2 1                    |
+| Subordinates      | 0, 1, 2, 3                 |
+| Object Type       | basic logical              |
+
+|                   |                   |
+|-------------------|-------------------|
+| Object Identifier | 3 0 3 1 0         |
+| Object Class      | 2 0 2 1 0         |
+| Content Portions  | 0 ('Belgaum')     |
+| Object Type       | basic logical     |
+| Object Identifier | 3 0 3 1 1         |
+| Object Class      | 2 0 2 1 1         |
+| Content Portions  | 0 ('54.3')        |
+| Object Type       | basic logical     |
+| Object Identifier | 3 0 3 1 2         |
+| Object Class      | 2 0 2 1 1         |
+| Content Portions  | 0 ('47.4')        |
+| Object Type       | basic logical     |
+| Object Identifier | 3 0 3 1 3         |
+| Object Class      | 2 0 2 1 1         |
+| Content Portions  | 0 ('54.1')        |
+| Object Type       | composite logical |
+| Object Identifier | 3 0 3 2           |
+| Object Class      | 2 0 2 1           |
+| Subordinates      | 0, 1, 2, 3        |
+| Object Type       | basic logical     |
+| Object Identifier | 3 0 3 2 0         |
+| Object Class      | 2 0 2 1 0         |
+| Content Portions  | 0 ('Calcutta')    |
+| Object Type       | basic logical     |
+| Object Identifier | 3 0 3 2 1         |
+| Object Class      | 2 0 2 1 1         |
+| Content Portions  | 0 ('39.7')        |
+| Object Type       | basic logical     |
+| Object Identifier | 3 0 3 2 2         |
+| Object Class      | 2 0 2 1 1         |
+| Content Portions  | 0 ('42.6')        |
+| Object Type       | basic logical     |
+| Object Identifier | 3 0 3 2 3         |
+| Object Class      | 2 0 2 1 1         |
+| Content Portions  | 0 ('47.2')        |
+| Object Type       | composite logical |
+| Object Identifier | 3 0 3 3           |
+| Object Class      | 2 0 2 1           |
+| Subordinates      | 0, 1, 2, 3        |
+| Object Type       | basic logical     |
+| Object Identifier | 3 0 3 3 0         |
+| Object Class      | 2 0 2 1 0         |
+| Content Portions  | 0 ('Gunter')      |
+| Object Type       | basic logical     |
+| Object Identifier | 3 0 3 3 1         |
+| Object Class      | 2 0 2 1 1         |
+| Content Portions  | 0 ('25.2')        |
+| Object Type       | basic logical     |
+| Object Identifier | 3 0 3 3 2         |
+| Object Class      | 2 0 2 1 1         |
+| Content Portions  | 0 ('39.3')        |
+| Object Type       | basic logical     |
+| Object Identifier | 3 0 3 3 3         |
+| Object Class      | 2 0 2 1 1         |
+| Content Portions  | 0 ('41.5')        |
+| Object Type       | composite logical |
+| Object Identifier | 3 0 3 4           |
+| Object Class      | 2 0 2 1           |
+| Subordinates      | 0, 1, 2, 3        |
+| Object Type       | basic logical     |
+| Object Identifier | 3 0 3 4 0         |
+
+|                   |                   |
+|-------------------|-------------------|
+| Object Class      | 2 0 2 1 0         |
+| Content Portions  | "0 ('Kaira')"     |
+| Object Type       | basic logical     |
+| Object Identifier | 3 0 3 4 1         |
+| Object Class      | 2 0 2 1 1         |
+| Content Portions  | 0 ('52.6')        |
+| Object Type       | basic logical     |
+| Object Identifier | 3 0 3 4 2         |
+| Object Class      | 2 0 2 1 1         |
+| Content Portions  | 0 ('50.0')        |
+| Object Type       | basic logical     |
+| Object Identifier | 3 0 3 4 3         |
+| Object Class      | 2 0 2 1 1         |
+| Content Portions  | 0 ('43.8')        |
+| Object Type       | composite logical |
+| Object Identifier | 3 0 3 5           |
+| Object Class      | 2 0 2 1           |
+| Subordinates      | 0, 1, 2, 3        |
+| Object Type       | basic logical     |
+| Object Identifier | 3 0 3 5 0         |
+| Object Class      | 2 0 2 1 0         |
+| Content Portions  | 0 ('Madurai')     |
+| Object Type       | basic logical     |
+| Object Identifier | 3 0 3 5 1         |
+| Object Class      | 2 0 2 1 1         |
+| Content Portions  | 0 ('38.6')        |
+| Object Type       | basic logical     |
+| Object Identifier | 3 0 3 1 2         |
+| Object Class      | 2 0 2 1 1         |
+| Content Portions  | 0 ('48.6')        |
+| Object Type       | basic logical     |
+| Object Identifier | 3 0 3 1 3         |
+| Object Class      | 2 0 2 1 1         |
+| Content Portions  | 0 ('51.0')        |
+
+![Figure B.10 – Specific Logical Structure of Example 5. A hierarchical tree diagram showing the logical structure of a document layout root. The root is '3', which branches into '30'. '30' branches into '300', '301', '302', and '303'. Each of these further branches into more specific identifiers, ending in a list of values in quotes. The diagram is labeled TISO5360-95/d33 at the bottom right.](1d62ade6b682fdfb8e192d10a06246a4_img.jpg)
+
+```
+
+graph LR
+    3[3] --- 30[30]
+    30 --- 300[300]
+    30 --- 301[301]
+    30 --- 302[302]
+    30 --- 303[303]
+    
+    300 --- V1["'% of Vote'"]
+    
+    301 --- 3010[3010]
+    301 --- 3011[3011]
+    301 --- 3012[3012]
+    301 --- 3020[3020]
+    
+    3010 --- V2["'1952'"]
+    3011 --- V3["'1957'"]
+    3012 --- V4["'1962'"]
+    3020 --- V5["'Parliament'"]
+    
+    302 --- 3021[3021]
+    302 --- 3022[3022]
+    302 --- 3023[3023]
+    302 --- 3024[3024]
+    302 --- 3025[3025]
+    
+    3021 --- 30210[30210]
+    3021 --- 30211[30211]
+    3021 --- 30212[30212]
+    3021 --- 30213[30213]
+    3022 --- 30220[30220]
+    3022 --- 30221[30221]
+    3022 --- 30222[30222]
+    3022 --- 30223[30223]
+    3023 --- 30230[30230]
+    3023 --- 30231[30231]
+    3023 --- 30232[30232]
+    3023 --- 30233[30233]
+    3024 --- 30240[30240]
+    3024 --- 30241[30241]
+    3024 --- 30242[30242]
+    3024 --- 30243[30243]
+    3025 --- 30250[30250]
+    3025 --- 30251[30251]
+    3025 --- 30252[30252]
+    3025 --- 30253[30253]
+    
+    30210 --- V6["'Belgaum'"]
+    30211 --- V7["'55.6'"]
+    30212 --- V8["'50.3'"]
+    30213 --- V9["'56.7'"]
+    30220 --- V10["'Calcutta'"]
+    30221 --- V11["'36.8'"]
+    30222 --- V12["'40.3'"]
+    30223 --- V13["'46.3'"]
+    30230 --- V14["'Gunter'"]
+    30231 --- V15["'31.6'"]
+    30232 --- V16["'56.5'"]
+    30233 --- V17["'45.6'"]
+    30240 --- V18["'Kaira'"]
+    30241 --- V19["'61.1'"]
+    30242 --- V20["'50.6'"]
+    30243 --- V21["'45.6'"]
+    30250 --- V22["'Madurai'"]
+    30251 --- V23["'52.6'"]
+    30252 --- V24["'34.5'"]
+    30253 --- V25["'54.1'"]
+    
+    303 --- 3030[3030]
+    303 --- 3031[3031]
+    303 --- 3032[3032]
+    303 --- 3033[3033]
+    303 --- 3034[3034]
+    303 --- 3035[3035]
+    
+    3030 --- V26["'Legislative Assembly'"]
+    3031 --- 30310[30310]
+    3031 --- 30311[30311]
+    3031 --- 30312[30312]
+    3031 --- 30313[30313]
+    3032 --- 30320[30320]
+    3032 --- 30321[30321]
+    3032 --- 30322[30322]
+    3032 --- 30323[30323]
+    3033 --- 30330[30330]
+    3033 --- 30331[30331]
+    3033 --- 30332[30332]
+    3033 --- 30333[30333]
+    3034 --- 30340[30340]
+    3034 --- 30341[30341]
+    3034 --- 30342[30342]
+    3034 --- 30343[30343]
+    3035 --- 30350[30350]
+    3035 --- 30351[30351]
+    3035 --- 30352[30352]
+    3035 --- 30353[30353]
+    
+    30310 --- V27["'Belgaum'"]
+    30311 --- V28["'54.3'"]
+    30312 --- V29["'47.4'"]
+    30313 --- V30["'54.1'"]
+    30320 --- V31["'Calcutta'"]
+    30321 --- V32["'39.7'"]
+    30322 --- V33["'42.6'"]
+    30323 --- V34["'47.2'"]
+    30330 --- V35["'Gunter'"]
+    30331 --- V36["'25.2'"]
+    30332 --- V37["'39.3'"]
+    30333 --- V38["'41.5'"]
+    30340 --- V39["'Kaira'"]
+    30341 --- V40["'52.6'"]
+    30342 --- V41["'50.0'"]
+    30343 --- V42["'43.8'"]
+    30350 --- V43["'Madurai'"]
+    30351 --- V44["'38.6'"]
+    30352 --- V45["'48.6'"]
+    30353 --- V46["'51.0'"]
+  
+```
+
+TISO5360-95/d33
+
+Figure B.10 – Specific Logical Structure of Example 5. A hierarchical tree diagram showing the logical structure of a document layout root. The root is '3', which branches into '30'. '30' branches into '300', '301', '302', and '303'. Each of these further branches into more specific identifiers, ending in a list of values in quotes. The diagram is labeled TISO5360-95/d33 at the bottom right.
+
+Figure B.10 – Specific Logical Structure of Example 5
+
+## B.5.3 Generic Layout Structure
+
+Object Type                      document layout root  
+ Object Identifier                0
+
+|                            |                                                                 |
+|----------------------------|-----------------------------------------------------------------|
+| Generator for Subordinates | REP ( 0 0 )                                                     |
+| Object Type                | page                                                            |
+| Object Identifier          | 0 0                                                             |
+| Generator for Subordinates | REQ ( 0 0 0 )                                                   |
+| Object Type                | grid frame                                                      |
+| Object Class Identifier    | 0 0 0 (table frame)                                             |
+| Generator for Subordinates | REP ( CHO ( 0 0 0 0, 0 0 0 1, 0 0 0 2, 0 0 0 3 ) )              |
+| Layout Path                | 270                                                             |
+| Dimensions                 |                                                                 |
+| Horizontal Dimension       |                                                                 |
+| Fixed Dimension            | 1680 (SMU)                                                      |
+| Vertical Dimension         |                                                                 |
+| Fixed Dimension            | 1200 (SMU)                                                      |
+| Major Path                 | 270                                                             |
+| Minor Path                 | 90                                                              |
+| Grid Position              |                                                                 |
+| Variable Position          |                                                                 |
+| Major Alignment            | centred                                                         |
+| Minor Alignment            | left-aligned                                                    |
+| Grid Dimensions            |                                                                 |
+| Major                      | rule b                                                          |
+| Minor                      | rule b                                                          |
+| Grid Interval Dimensions   |                                                                 |
+| Major Interval Dimensions  | OPTREP ( proportional { group = 1 , im-dim = 1, default = 0 } ) |
+| Minor Interval Dimensions  | SEQ (                                                           |
+|                            | rule-b { minimum = 240 (SMU) },                                 |
+|                            | OPTREP ( proportional { group = 1, im-dim = 1, default = 0 } )  |
+|                            | )                                                               |
+| Grid Lines                 |                                                                 |
+| Major Grid Lines           | SEQ (                                                           |
+|                            | { OPTREP ( { 1, solid, black } ), precedence = 1 },             |
+|                            | { OPTREP ( { 3, double, black } ), precedence = 2 },            |
+|                            | OPTREP (                                                        |
+|                            | { OPTREP ( { 1, invisible, black } ), precedence = 0 }          |
+|                            | ),                                                              |
+|                            | { OPTREP ( { 1, solid, black } ), precedence = 1 }              |
+|                            | )                                                               |
+| Minor Grid Lines           | SEQ (                                                           |
+|                            | { OPTREP ( { 1, invisible, black } ), precedence = 1 },         |
+|                            | OPTREP (                                                        |
+|                            | { OPTREP ( { 1, solid, black } ), precedence = 0 }              |
+|                            | ),                                                              |
+|                            | { OPTREP ( { 1, invisible, black } ), precedence = 1 }          |
+|                            | )                                                               |
+| Grid Gutters               |                                                                 |
+| Around Major Grid Lines    | OPTREP ( { width = 80 (SMU), precedence = 0 } )                 |
+| Around Minor Grid Lines    | OPTREP ( { width = 160 (SMU), precedence = 0 } )                |
+| Object Type                | frame                                                           |
+| Object Class Identifier    | 0 0 0 0 (entry frame for title and box headings)                |
+| Position                   |                                                                 |
+| Variable Position          |                                                                 |
+| Fill Order                 | normal                                                          |
+| Offset                     | leading = trailing = left-hand = right-hand = 0                 |
+| Alignment                  | centred                                                         |
+| Permitted Categories       | 'title', 'attribute'                                            |
+| Object Type                | frame                                                           |
+| Object Class Identifier    | 0 0 0 1 (entry frame for subtable title)                        |
+| Position                   |                                                                 |
+| Variable Position          |                                                                 |
+| Fill Order                 | normal                                                          |
+| Offset                     | leading = trailing = left-hand = right-hand = 0                 |
+| Alignment                  | right-hand aligned                                              |
+| Permitted Categories       | 'subtitle'                                                      |
+| Object Type                | frame                                                           |
+| Object Class Identifier    | 0 0 0 2 (entry frame for row headings)                          |
+| Position                   |                                                                 |
+
+|                         |                                                      |
+|-------------------------|------------------------------------------------------|
+| Variable Position       |                                                      |
+| Fill Order              | normal                                               |
+| Offset                  | leading = trailing = left-hand = 0, right-hand = 240 |
+| Alignment               | right-hand aligned                                   |
+| Permitted Categories    | 'index'                                              |
+| Object Type             | frame                                                |
+| Object Class Identifier | 0 0 0 3 (entry frame for data items)                 |
+| Position                |                                                      |
+| Variable Position       |                                                      |
+| Fill Order              | normal                                               |
+| Offset                  | leading = trailing = left-hand = right-hand = 0      |
+| Alignment               | centred                                              |
+| Permitted Categories    | 'value'                                              |
+
+#### B.5.4 Layout Style
+
+|                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
+|--------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Layout Style Identifier        | 4 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
+| Grid Frame Classes             | OPTREP ( 0 0 0 )                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
+| Layout Style Identifier        | 4 1                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
+| Layout Category                | 'title'                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
+| Layout Style Identifier        | 4 2                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
+| Layout Style Identifier        | 4 3                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
+| Layout Category                | 'attribute'                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
+| Layout Style Identifier        | 4 4                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
+| Obligatory Same Layout Objects |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
+| Logical Objects                | 2 0 1                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
+| Layout Objects                 | 0 0 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
+| Layout Style Identifier        | 4 5                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
+| Layout Category                | 'subtitle'                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
+| Layout Style Identifier        | 4 6                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
+| Layout Style Identifier        | 4 7                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
+| Layout Category                | 'index'                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
+| Layout Style Identifier        | 4 8                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
+| Layout Category                | 'value'                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
+| Layout Style Identifier        | 4 10                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
+| Grid Description               |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
+| Major Size                     | 14                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
+| Minor Size                     | 4                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
+| Entry Location Association     | { location = { (0, 0), (1,4)}, entries = {0} },<br>{ location = { (1, 1), }, entries = {1 0} },<br>{ location = { (1, 2), }, entries = {1 1} },<br>{ location = { (1, 3), }, entries = {1 2} },<br>{ location = { (2, 0), }, entries = {2 0} },<br>{ location = { (3, 0), }, entries = {2 1 0} },<br>{ location = { (3, 1), }, entries = {2 1 1} },<br>{ location = { (3, 2), }, entries = {2 1 2} },<br>{ location = { (3, 3), }, entries = {2 1 3} },<br>{ location = { (4, 0), }, entries = {2 2 0} },<br>{ location = { (4, 1), }, entries = {2 2 1} },<br>{ location = { (4, 2), }, entries = {2 2 2} },<br>{ location = { (4, 3), }, entries = {2 2 3} },<br>{ location = { (5, 0), }, entries = {2 3 0} },<br>{ location = { (5, 1), }, entries = {2 3 1} },<br>{ location = { (5, 2), }, entries = {2 3 2} },<br>{ location = { (5, 3), }, entries = {2 3 3} },<br>{ location = { (6, 0), }, entries = {2 4 0} },<br>{ location = { (6, 1), }, entries = {2 4 1} },<br>{ location = { (6, 2), }, entries = {2 4 2} },<br>{ location = { (6, 3), }, entries = {2 4 3} },<br>{ location = { (7, 0), }, entries = {2 5 0} },<br>{ location = { (7, 1), }, entries = {2 5 1} },<br>{ location = { (7, 2), }, entries = {2 5 2} }, |
+
+```
+
+{ location = { (7, 3), }, entries = {2 5 3} },
+{ location = { (8, 0), }, entries = {3 0} },
+{ location = { (9, 0), }, entries = {3 1 0} },
+{ location = { (9, 1), }, entries = {3 1 1} },
+{ location = { (9, 2), }, entries = {3 1 2} },
+{ location = { (9, 3), }, entries = {3 1 3} },
+{ location = { (10, 0), }, entries = {3 2 0} },
+{ location = { (10, 1), }, entries = {3 2 1} },
+{ location = { (10, 2), }, entries = {3 2 2} },
+{ location = { (10, 3), }, entries = {3 2 3} },
+{ location = { (11, 0), }, entries = {3 3 0} },
+{ location = { (11, 1), }, entries = {3 3 1} },
+{ location = { (11, 2), }, entries = {3 3 2} },
+{ location = { (11, 3), }, entries = {3 3 3} },
+{ location = { (12, 0), }, entries = {3 4 0} },
+{ location = { (12, 1), }, entries = {3 4 1} },
+{ location = { (12, 2), }, entries = {3 4 2} },
+{ location = { (12, 3), }, entries = {3 4 3} },
+{ location = { (13, 0), }, entries = {3 5 0} },
+{ location = { (13, 1), }, entries = {3 5 1} },
+{ location = { (13, 2), }, entries = {3 5 2} },
+{ location = { (13, 3), }, entries = {3 5 3} }
+
+```
+
+### B.5.5 Explanation
+
+Figure B.11 depicts the image of tabular layout the layout process generates by applying the generic layout structure (see B.5.3) and the layout styles (see B.5.4) to the logical structures (see B.5.1 and B.5.2).
+
+| % of Vote            |      |      |      |
+|----------------------|------|------|------|
+|                      | 1952 | 1957 | 1962 |
+| Parliament           |      |      |      |
+| Belgaum              | 55.6 | 50.3 | 56.7 |
+| Calcutta             | 36.8 | 40.3 | 46.3 |
+| Gunter               | 31.6 | 56.5 | 43.5 |
+| Kaira                | 61.1 | 50.6 | 45.6 |
+| Madurai              | 52.6 | 34.5 | 39.6 |
+| Legislative Assembly |      |      |      |
+| Belgaum              | 54.3 | 47.4 | 54.1 |
+
+|          | 1952 | 1957 | 1962 |
+|----------|------|------|------|
+| Calcutta | 39.7 | 42.6 | 47.2 |
+| Gunter   | 25.2 | 39.3 | 41.5 |
+| Kaira    | 52.6 | 50.0 | 43.8 |
+| Madurai  | 38.6 | 48.6 | 51.0 |
+
+Figure B.11 – Layout of Example 5
+
+#### B.5.5.1 Imaging line segments within spanning cell
+
+A table cell spanning two or more columns or rows, such as the table cell containing ‘% of Vote’ in Figure B.11, is called *spanning cell*. More formally, if an entry frame is bound to a layout grid rectangle which is composed of two or more layout grid locations, the layout grid rectangle is called a *spanning grid rectangle*.
+
+When a line segment of a layout grid line is included in the interior of some spanning rectangle, the line segment shall not be imaged.
+
+For example, since the entry object 3 0 0 occupies a logical grid rectangle whose vertices are (0, 0), (0, 4), (1, 4) and (1,0), the entry frame for the content '% of Vote' is bound to a layout grid rectangle spanning all the columns. The first line segments of the 1st to 3rd minor (vertical) layout grid lines, each of which is between the 0th and 1st major (horizontal) layout grid lines, are included in the interior of this spanning grid rectangle. Therefore, although the parameter "minor grid lines" specifies that these line segments are to be imaged by using the line segment characteristic {1, solid, black}, they are not actually imaged.
+
+### B.5.5.2 Repetitive layout of box headings
+
+In Figure B.11, the content of the table overflows into a second grid frame within a second page. The upper table of Figure B.11 is the part laid out within the first grid frame, whilst the lower is the part laid out within the second grid frame. The content of the logical object 3 0 1, namely '1952', '1957' and '1962', is duplicatedly laid out within the second grid frame, since the layout directive attribute "obligatory same layout objects" are applied to the logical object class 2 0 2.
+
+### B.5.5.3 Indentation within stub
+
+The rightmost column of the table is called a *stub*. In the stub, indentations are used to represent the classification of the row headings.
+
+The content associated with the basic logical objects belonging to the logical object class 2 0 2 0 is laid out within instances of the frame class 0 0 0 1, since the same layout category 'subtitle' is specified for both the object classes. Hence, the content of the entry object 3 0 2 0 ('Parliament') and that of the entry object 3 0 3 0 ('Legislative Assembly') are laid out within lowest-level frames which are instances of the frame class 0 0 0 1.
+
+Since the sub-parameter "alignment" of the attribute "position" specified for the frame class 0 0 0 1 specifies the value 'right-hand aligned', each of those lowest-level frames is positioned within the available area so that its right-hand edge (relative to the layout path of the immediately superior grid frame) shall have the same horizontal position as the corresponding edge of the available area does. The available area is to be determined taking account of the gutter space width around layout grid lines and the offsets of this frame. Since the specified gutter space width around the 0th minor layout grid line is 160 SMU and the right-hand offset specified for the frame class 0 0 0 1 is 0 SMU, the distance between the right-hand edge of the available area for this lowest-level frame and the 0th minor layout grid line is 80 SMU (see Figure B.12).
+
+On the other hand, the content associated with the basic logical objects belonging to the object class 2 0 2 1 0 is laid out within instances of the frame class 0 0 0 2, since the same layout category 'index' is applied to both the object classes. Hence, the content of those basic logical objects ('Belgaum', 'Calcutta', 'Gunter', 'Kaira' and 'Madurai') is laid out within lowest-level frames which are instances of the frame class 0 0 0 2.
+
+Those lowest-level frames are also right-hand aligned within their available areas. However, since the right-hand offset is specified as 240 for the frame class 0 0 0 2, the distance between the right-hand edges of the available areas for the lowest-level frames and the 0th minor layout grid line is 240 SMU (see Figure B.12).
+
+## B.6 Example 6
+
+### B.6.1 Generic Logical Structure
+
+This example uses the same generic logical structure as that defined in B.5.1.
+
+### B.6.2 Specific Logical Structure
+
+This example uses the same specific logical structure as that defined in B.5.2.
+
+### B.6.3 Generic Layout Structure
+
+|                                   |                             |
+|-----------------------------------|-----------------------------|
+| <b>Object Type</b>                | <b>document layout root</b> |
+| <b>Object Identifier</b>          | <b>0</b>                    |
+| <b>Generator for Subordinates</b> | <b>REP ( 0 0 )</b>          |
+
+![Diagram illustrating indentation layout. It shows a vertical stack of text boxes: Parliament, Belgaum, Calcutta, Gunter, Kaira, Madurai, Legislative Assembly, and Belgaum. The layout is defined by a grid with dashed lines. Dimensions are specified: Gutter/2 = 80 (horizontal), Gutter = 80 (vertical), right-hand offset = 240 (horizontal), and Layout path (vertical). A legend indicates that the shaded area is the 'Available area' and the dashed line is the 'Layout grid line'. The reference TISO5370-95/d34 is noted at the bottom right.](52fe5bc3ba967e0e8f56f1a3ab9d9c3e_img.jpg)
+
+TISO5370-95/d34
+
+Diagram illustrating indentation layout. It shows a vertical stack of text boxes: Parliament, Belgaum, Calcutta, Gunter, Kaira, Madurai, Legislative Assembly, and Belgaum. The layout is defined by a grid with dashed lines. Dimensions are specified: Gutter/2 = 80 (horizontal), Gutter = 80 (vertical), right-hand offset = 240 (horizontal), and Layout path (vertical). A legend indicates that the shaded area is the 'Available area' and the dashed line is the 'Layout grid line'. The reference TISO5370-95/d34 is noted at the bottom right.
+
+Figure B.12 – Indentation
+
+|                            |                                                                |
+|----------------------------|----------------------------------------------------------------|
+| Object Type                | page                                                           |
+| Object Identifier          | 0 0                                                            |
+| Generator for Subordinates | REQ ( 0 0 0 )                                                  |
+| Object Type                | grid frame                                                     |
+| Object Class Identifier    | 0 0 0 (table frame)                                            |
+| Generator for Subordinates | REP ( CHO ( 0 0 0 0, 0 0 0 1, 0 0 0 2 ) )                      |
+| Layout Path                | 270                                                            |
+| Dimensions                 |                                                                |
+| Horizontal Dimension       |                                                                |
+| Fixed Dimension            | 1680 (SMU)                                                     |
+| Vertical Dimension         |                                                                |
+| Fixed Dimension            | 1200 (SMU)                                                     |
+| Major Path                 | 270                                                            |
+| Minor Path                 | 90                                                             |
+| Grid Position              |                                                                |
+| Variable Position          |                                                                |
+| Major Alignment            | centred                                                        |
+| Minor Alignment            | left-hand aligned                                              |
+| Grid Dimensions            |                                                                |
+| Major                      | rule b                                                         |
+| Minor                      | rule b                                                         |
+| Grid Interval Dimensions   |                                                                |
+| Major Interval Dimensions  | OPTREP ( proportional { group = 1, im-dim = 1, default = 0 } ) |
+| Minor Interval Dimensions  | SEQ (                                                          |
+|                            | rule-b { minimum = 240 (SMU) },                                |
+|                            | OPTREP ( proportional { group = 1, im-dim = 1, default = 0 } ) |
+|                            | )                                                              |
+| Grid Lines                 |                                                                |
+| Major Grid Lines           | SEQ (                                                          |
+
+|                                |                                                                                                                                                                                                                                                                                           |
+|--------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+|                                | <pre> { OPTREP ( { 1, solid, black } ), precedence = 1 }, { OPTREP ( { 3, double, black } ), precedence = 2 }, OPTREP (     { SEQ ( { 1, invisible, black },             OPTREP ( { 1, solid, black } )), precedence = 0 } ), { OPTREP ( { 1, solid, black } ), precedence = 1 } ) </pre> |
+| Minor Grid Lines               | <pre> SEQ (     { OPTREP ( { 1, invisible, black } ), precedence = 1 },     OPTREP (         { OPTREP ( { 1, solid, black } ), precedence = 0 }     ),     { OPTREP ( { 1, invisible, black } ), precedence = 1 } ) </pre>                                                                |
+| Grid Gutters                   |                                                                                                                                                                                                                                                                                           |
+| Around Major Grid Lines        | OPTREP ( { width = 80 (SMU), precedence = 0 } )                                                                                                                                                                                                                                           |
+| Around Minor Grid Lines        | OPTREP ( { width = 160 (SMU), precedence = 0 } )                                                                                                                                                                                                                                          |
+| Object Type                    | frame                                                                                                                                                                                                                                                                                     |
+| Object Class Identifier        | 0 0 0 0 (entry frame for title, box heading and subtable title)                                                                                                                                                                                                                           |
+| Position                       |                                                                                                                                                                                                                                                                                           |
+| Variable Position              |                                                                                                                                                                                                                                                                                           |
+| Fill Order                     | normal                                                                                                                                                                                                                                                                                    |
+| Offset                         | leading = trailing = left-hand = right-hand = 0                                                                                                                                                                                                                                           |
+| Alignment                      | centred                                                                                                                                                                                                                                                                                   |
+| Permitted Categories           | 'title', 'attribute', 'subtitle'                                                                                                                                                                                                                                                          |
+| Object Type                    | frame                                                                                                                                                                                                                                                                                     |
+| Object Class Identifier        | 0 0 0 1 (entry frame for row headings)                                                                                                                                                                                                                                                    |
+| Position                       |                                                                                                                                                                                                                                                                                           |
+| Variable Position              |                                                                                                                                                                                                                                                                                           |
+| Fill Order                     | normal                                                                                                                                                                                                                                                                                    |
+| Offset                         | leading = trailing = left-hand = right-hand = 0                                                                                                                                                                                                                                           |
+| Alignment                      | right-hand aligned                                                                                                                                                                                                                                                                        |
+| Object Type                    | frame                                                                                                                                                                                                                                                                                     |
+| Object Class Identifier        | 0 0 0 2 (entry frame for data items)                                                                                                                                                                                                                                                      |
+| Position                       |                                                                                                                                                                                                                                                                                           |
+| Variable Position              |                                                                                                                                                                                                                                                                                           |
+| Fill Order                     | normal                                                                                                                                                                                                                                                                                    |
+| Offset                         | leading = trailing = left-hand = right-hand = 0                                                                                                                                                                                                                                           |
+| Alignment                      | centred                                                                                                                                                                                                                                                                                   |
+| Subordinate Dependent          | applied                                                                                                                                                                                                                                                                                   |
+| Permitted Categories           | 'value'                                                                                                                                                                                                                                                                                   |
+| <b>B.6.4 Layout Style</b>      |                                                                                                                                                                                                                                                                                           |
+| Layout Style Identifier        | 4 0                                                                                                                                                                                                                                                                                       |
+| Grid Frame Classes             | OPTREP ( 0 0 0 )                                                                                                                                                                                                                                                                          |
+| Layout Style Identifier        | 4 1                                                                                                                                                                                                                                                                                       |
+| Layout Category                | 'title'                                                                                                                                                                                                                                                                                   |
+| Layout Style Identifier        | 4 2                                                                                                                                                                                                                                                                                       |
+| Layout Style Identifier        | 4 3                                                                                                                                                                                                                                                                                       |
+| Layout Category                | 'attribute'                                                                                                                                                                                                                                                                               |
+| Layout Style Identifier        | 4 4                                                                                                                                                                                                                                                                                       |
+| Layout Style Identifier        | 4 5                                                                                                                                                                                                                                                                                       |
+| Selective Same Layout Objects  |                                                                                                                                                                                                                                                                                           |
+| Logical Objects                | 2 0 2 1                                                                                                                                                                                                                                                                                   |
+| Layout Objects                 | 0 0 0                                                                                                                                                                                                                                                                                     |
+| Layout Category                | 'subtitle'                                                                                                                                                                                                                                                                                |
+| Layout Style Identifier        | 4 6                                                                                                                                                                                                                                                                                       |
+| Obligatory Same Layout Objects |                                                                                                                                                                                                                                                                                           |
+| Logical Objects                | 2 0 1, 2 0 2 0                                                                                                                                                                                                                                                                            |
+| Layout Objects                 | "0 0 0"                                                                                                                                                                                                                                                                                   |
+| Layout Style Identifier        | 4 7                                                                                                                                                                                                                                                                                       |
+| Layout Category                | 'index'                                                                                                                                                                                                                                                                                   |
+
+|                            |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
+|----------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Layout Style Identifier    | 4 8                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
+| Layout Category            | 'value'                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
+| Layout Style Identifier    | "4 10"                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
+| Grid Description           |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
+| Major Size                 | 6                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
+| Minor Size                 | 4                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
+| Entry Location Association | <pre> { location = {(0, 0), (1, 4)} , entries = {0} }, { location = {(1, 1), }, entries = {1 0} }, { location = {(1, 2), }, entries = {1 1} }, { location = {(1, 3), }, entries = {1 2} }, { location = {(2, 1), (3,4)} , entries = {2 0} }, { location = {(3, 0), }, entries = {2 1 0} }, { location = {(3, 1), }, entries = {2 1 1} }, { location = {(3, 2), }, entries = {2 1 2} }, { location = {(3, 3), }, entries = {2 1 3} }, { location = {(3, 0), }, entries = {2 2 0} }, { location = {(3, 1), }, entries = {2 2 1} }, { location = {(3, 2), }, entries = {2 2 2} }, { location = {(3, 3), }, entries = {2 2 3} }, { location = {(3, 0), }, entries = {2 3 0} }, { location = {(3, 1), }, entries = {2 3 1} }, { location = {(3, 2), }, entries = {2 3 2} }, { location = {(3, 3), }, entries = {2 3 3} }, { location = {(3, 0), }, entries = {2 4 0} }, { location = {(3, 1), }, entries = {2 4 1} }, { location = {(3, 2), }, entries = {2 4 2} }, { location = {(3, 3), }, entries = {2 4 3} }, { location = {(3, 0), }, entries = {2 5 0} }, { location = {(3, 1), }, entries = {2 5 1} }, { location = {(3, 2), }, entries = {2 5 2} }, { location = {(3, 3), }, entries = {2 5 3} }, { location = {(4, 1), (5, 4)} , entries = {3 0} }, { location = {(5, 0), }, entries = {3 1 0} }, { location = {(5, 1), }, entries = {3 1 1} }, { location = {(5, 2), }, entries = {3 1 2} }, { location = {(5, 3), }, entries = {3 1 3} }, { location = {(5, 0), }, entries = {3 2 0} }, { location = {(5, 1), }, entries = {3 2 1} }, { location = {(5, 2), }, entries = {3 2 2} }, { location = {(5, 3), }, entries = {3 2 3} }, { location = {(5, 0), }, entries = {3 3 0} }, { location = {(5, 1), }, entries = {3 3 1} }, { location = {(5, 2), }, entries = {3 3 2} }, { location = {(5, 3), }, entries = {3 3 3} }, { location = {(5, 0), }, entries = {3 4 0} }, { location = {(5, 1), }, entries = {3 4 1} }, { location = {(5, 2), }, entries = {3 4 2} }, { location = {(5, 3), }, entries = {3 4 3} }, { location = {(5, 0), }, entries = {3 5 0} }, { location = {(5, 1), }, entries = {3 5 1} }, { location = {(5, 2), }, entries = {3 5 2} }, { location = {(5, 3), }, entries = {3 5 3} } </pre> |
+
+### B.6.5 Explanation
+
+Figure B.13 depicts the image of tabular layout that the layout process generates by applying the different generic layout structure (see B.6.3) and the different layout styles (see B.6.4) to the same logical structures (see B.5.1 and B.5.2).
+
+#### B.6.5.1 Repetitive layout of box headings and cut-in headings
+
+Within the second grid frame into which the content of the table overflows, not only box headings ('1952', '1957' and '1962') but also the cut-in heading ('Legislative Assembly') are repeatedly laid out.
+
+This repetitive layout of the headings is specified by the layout directive "obligatory same layout objects" which is specified for the layout style 4 6, and referred to from the logical object class 2 0 2 1.
+
+When the layout process commences to lay out the content associated with the logical object 3 0 3 2, which is the first content to overflow into the second grid frame, the layout process evaluates this instance of the layout directive "obligatory same layout objects". From the value of the parameter "logical objects", two target objects are identified: the
+
+basic logical object 3 0 3 0 and the composite logical object 3 0 1. The former object is associated with the cut-in heading ‘Legislative Assembly’, while the latter with the box headings ‘1952’, ‘1957’ and ‘1962’. Hence, when the layout process lays out the content of the logical object 3 0 3 2, it generates 4 content portions forming part of a reproduction bundle of the content associated with those target objects. These content portions are laid out within the 2nd grid frame, which is of the layout class that the parameter “layout objects” specifies.
+
+| % of Vote                                         |                      |      |      |
+|---------------------------------------------------|----------------------|------|------|
+|                                                   | 1952                 | 1957 | 1962 |
+| Belgaum<br>Calcutta<br>Gunter<br>Kaira<br>Madurai | Parliament           |      |      |
+|                                                   | 55.6                 | 50.3 | 56.7 |
+|                                                   | 36.8                 | 40.3 | 46.3 |
+|                                                   | 31.6                 | 56.5 | 43.5 |
+|                                                   | 61.1                 | 50.6 | 45.6 |
+|                                                   | 52.6                 | 34.5 | 39.6 |
+| Belgaum                                           | Legislative Assembly |      |      |
+|                                                   | 54.3                 | 47.4 | 54.1 |
+
+  
+
+|                                        | 1952                 | 1957 | 1962 |
+|----------------------------------------|----------------------|------|------|
+| Calcutta<br>Gunter<br>Kaira<br>Madurai | Legislative Assembly |      |      |
+|                                        | 39.7                 | 42.6 | 47.2 |
+|                                        | 25.2                 | 39.3 | 41.5 |
+|                                        | 52.6                 | 50.0 | 43.8 |
+|                                        | 38.6                 | 48.6 | 51.0 |
+
+**Figure B.13 – Cut-in heads**
+
+### B.6.5.2 Prevention of redundant duplication of cut-in headings
+
+Figure B.14 depicts an example of tabular layout where a cut-in heading is redundantly repeated: the first occurrence of the cut-in heading ‘Legislative Assembly’ is unnecessary.
+
+To prevent such redundant layout of cut-in headings from occurring, the layout directive “selective same layout objects” is specified in the layout styles: the layout directive is specified for the layout style 4 5, which is referred to from the logical object class 2 0 2 0. When the layout directive is applied to the logical object 3 0 3 0, whose associated content is ‘Legislative Assembly’, the target object 3 0 3 1 is identified by the parameter “logical objects” of the layout directive. This target object is the nearest following logical object in the sequential logical order as long as it belongs to the logical object class specified by the parameter “logical objects”.
+
+The layout directive “selective same layout objects” specifies that the end of the content associated with the logical object to which the directive is applied shall be laid out together with, at least, some fragments of the content of the target object within a single layout object whose class is specified by the parameter “layout objects” of the directive. Since the first occurrence of the cut-in heading ‘Legislative Assembly’ in Figure B.14 does not satisfy this constraint, it is consequently restrained from occurring.
+
+## B.7 Example 7
+
+### B.7.1 Generic Logical Structure
+
+|                         |                       |
+|-------------------------|-----------------------|
+| Object Type             | document logical root |
+| Object Class Identifier | 2                     |
+
+**Generator for Subordinates**            **REQ ( 2 0 )**  
+**Object Type**                            **grid logical (table root)**  
+**Object Class Identifier**            **2 0**  
+**Generator for Subordinates**            **OPTREP ( 2 0 0 )**
+
+| % of Vote            |                      |      |      |
+|----------------------|----------------------|------|------|
+|                      | 1952                 | 1957 | 1962 |
+|                      | Parliament           |      |      |
+| Belgaum              | 55.6                 | 50.3 | 56.7 |
+| Calcutta             | 36.8                 | 40.3 | 46.3 |
+| Gunter               | 31.6                 | 56.5 | 43.5 |
+| Kaira                | 61.1                 | 50.6 | 45.6 |
+| Madurai              | 52.6                 | 34.5 | 39.6 |
+| Legislative Assembly |                      |      |      |
+|                      | 1952                 | 1957 | 1962 |
+|                      | Legislative Assembly |      |      |
+| Belgaum              | 54.3                 | 47.4 | 54.1 |
+| Calcutta             | 39.7                 | 42.6 | 47.2 |
+| Gunter               | 25.2                 | 39.3 | 41.5 |
+| Kaira                | 52.6                 | 50.0 | 43.8 |
+| Madurai              | 38.6                 | 48.6 | 51.0 |
+
+Figure B.14 – Redundant duplication of table headings
+
+**Object Type**                            **composite logical (data group)**  
+**Object Class Identifier**            **2 0 0**  
+**Generator for Subordinates**            **SEQ ( OPTREP ( 2 0 0 0 ), 2 0 0 1 )**
+
+**Object Type**                            **basic logical (data)**  
+**Object Class Identifier**            **2 0 0 0**  
+**Layout Style**                          **4 0**  
+**Presentation Style**                 **5 0**  
+**Layout Category**                    **'data'**
+
+**Object Type**                            **basic logical (sum)**  
+**Object Class Identifier**            **2 0 0 1**  
+**Layout Style**                          **4 0**  
+**Presentation Style**                 **5 0**  
+**Layout Category**                    **'sum'**
+
+### B.7.2 Layout Styles
+
+**Layout Style Identifier**            **4 0**  
+**Block Alignment Point**  
+    **Content Dependent**            **applies**  
+**Layout Style Identifier**            **4 1**  
+**Grid Description**  
+    **Major Size**                      **6**  
+    **Minor Size**                      **1**  
+    **Entry Location Association**    { location = {(0, 0), }, entries = {0} },  
+                                             { location = {(1, 0), }, entries = {1} },  
+                                             { location = {(2, 0), }, entries = {2} },  
+                                             { location = {(3, 0), }, entries = {3} },
+
+```
+{ location = {(4, 0), }, entries = {4} },
+{ location = {(5, 0), }, entries = {5} }
+```
+
+**B.7.3 Presentation Styles**
+
+|                               |                     |
+|-------------------------------|---------------------|
+| Presentation Style Identifier | 5 0                 |
+| Alignment Point               |                     |
+| Position In Character Path    | ',' (decimal point) |
+
+**B.7.4 Generic Layout Structure**
+
+|                                  |                                                    |
+|----------------------------------|----------------------------------------------------|
+| Object Type                      | document layout root                               |
+| Object Identifier                | 0                                                  |
+| Generator for Subordinates       | REQ ( 0 0 )                                        |
+| Object Type                      | "page"                                             |
+| Object Identifier                | 0 0                                                |
+| Generator for Subordinates       | REQ ( 0 0 0 )                                      |
+| Object Type                      | grid frame                                         |
+| Object Class Identifier          | 0 0 0 (table frame)                                |
+| Generator for Subordinates       | REP ( CHO ( 0 0 0 0, 0 0 0 1 ) )                   |
+| Layout Path                      | 270                                                |
+| Dimensions                       |                                                    |
+| Horizontal Dimension             |                                                    |
+| Variable Dimension               | rule b                                             |
+| Vertical Dimension               |                                                    |
+| Variable Dimension               | rule b                                             |
+| Major Path                       | 270                                                |
+| Minor Path                       | 90                                                 |
+| Grid Position                    |                                                    |
+| Variable Position                |                                                    |
+| Major Alignment                  | centred                                            |
+| Minor Alignment                  | centred                                            |
+| Grid Dimensions                  |                                                    |
+| Major                            | rule b                                             |
+| Minor                            | rule b                                             |
+| Grid Interval Dimensions         |                                                    |
+| Major Interval Dimensions        | OPTREP ( rule-b { , } )                            |
+| Minor Interval Dimensions        | OPTREP ( rule-b { , } )                            |
+| Grid Lines                       |                                                    |
+| Major Grid Lines                 | OPTREP ( { OPTREP ( { 1, invisible, black }, ) } ) |
+| Minor Grid Lines                 | OPTREP ( { OPTREP ( { 1, invisible, black }, ) } ) |
+| Grid Gutters                     |                                                    |
+| Around Major Grid Lines          | OPTREP ( { , } )                                   |
+| Around Minor Grid Lines          | OPTREP ( { , } )                                   |
+| Object Type                      | frame                                              |
+| Object Class Identifier          | 0 0 0 0 (entry frame for data)                     |
+| Position                         |                                                    |
+| Variable Position                |                                                    |
+| Fill Order                       | normal                                             |
+| Offset                           | leading = trailing = left-hand = right-hand = 0    |
+| Alignment                        | centred                                            |
+| Reference Line Alignment – Major |                                                    |
+| Aligned With                     | 0 0 0 1                                            |
+| Frame Alignment Point            |                                                    |
+| subordinate dependent            | first                                              |
+| Permitted Categories             | 'data'                                             |
+| Object Type                      | frame                                              |
+| Object Class Identifier          | 0 0 0 1 (entry frame for sum)                      |
+| Position                         |                                                    |
+| Variable Position                |                                                    |
+| Fill Order                       | normal                                             |
+| Offset                           | leading = trailing = left-hand = right-hand = 0    |
+| Alignment                        | centred                                            |
+| Indent – Major                   | 240 (SMU)                                          |
+| Frame Alignment Point            |                                                    |
+| subordinate dependent            | "first"                                            |
+
+Permitted Categories 'sum'
+
+### B.7.5 Specific Logical Structure
+
+|                              |                                |
+|------------------------------|--------------------------------|
+| Object Type                  | document logical root          |
+| Object Identifier            | 3                              |
+| Object Class                 | 2                              |
+| Subordinates                 | 0                              |
+| Object Type                  | grid logical (table root)      |
+| Object Identifier            | 3 0                            |
+| Object Class                 | 2 0                            |
+| Subordinates                 | 0, 1                           |
+| Layout Style                 | 4 1                            |
+| Object Type                  | composite logical (data group) |
+| Object Identifier            | 3 0 0                          |
+| Object Class                 | 2 0 0                          |
+| Subordinates                 | 0, 1, 2                        |
+| Object Type                  | basic logical (data)           |
+| Object Identifier            | 3 0 0 0                        |
+| Object Class                 | 2 0 0 0                        |
+| Content Portions             | 0                              |
+| Object Type                  | basic logical (data)           |
+| Object Identifier            | 3 0 0 1                        |
+| Object Class                 | 2 0 0 0                        |
+| Content Portions             | 0                              |
+| Object Type                  | basic logical (sum)            |
+| Object Identifier            | 3 0 0 2                        |
+| Object Class                 | 2 0 0 1                        |
+| Content Portions             | 0                              |
+| Object Type                  | composite logical (data group) |
+| Object Identifier            | 3 0 1                          |
+| Object Class                 | 2 0 0                          |
+| Subordinates                 | 0, 1, 2                        |
+| Object Type                  | basic logical (data)           |
+| Object Identifier            | 3 0 1 0                        |
+| Object Class                 | 2 0 0 0                        |
+| Content Portions             | 0                              |
+| Object Type                  | basic logical (data)           |
+| Object Identifier            | 3 0 1 1                        |
+| Object Class                 | 2 0 0 0                        |
+| Content Portions             | 0                              |
+| Object Type                  | basic logical (sum)            |
+| Object Identifier            | 3 0 1 2                        |
+| Object Class                 | 2 0 0 1                        |
+| Content Portions             | 0                              |
+| Content Identifier – Logical | 3 0 0 0 0                      |
+| Content Information          | '1.164'                        |
+| Content Identifier – Logical | 3 0 0 1 0                      |
+| Content Information          | '1.872'                        |
+| Content Identifier – Logical | 3 0 0 2 0                      |
+| Content Information          | '3.036'                        |
+| Content Identifier – Logical | 3 0 1 0 0                      |
+| Content Information          | '9.391'                        |
+| Content Identifier – Logical | 3 0 1 1 0                      |
+| Content Information          | '19.376'                       |
+| Content Identifier – Logical | 3 0 1 2 0                      |
+| Content Information          | '28.376'                       |
+
+### B.7.6 Explanation
+
+Figure B.15 depicts the image of the page that the layout process generates from the logical and layout structures (see B.7.1, B.7.4 and B.7.5) and the layout and presentation styles (see B.7.2 and B.7.3).
+
+![Figure B.15: Reference Line Alignment. A diagram showing a rectangular box containing text aligned to a vertical dashed reference line. The text inside the box is: 1,164, 1,872, 3,036, 9,391, 19,376, and 28,767. Below the box, a horizontal double-headed arrow indicates a distance of 240 units from the reference line to the right edge of the box. The reference line is labeled 'Reference Line' and 'ISO5380-95/d35'.](3334fcca5dac808f4fd3840aba35bc2e_img.jpg)
+
+ISO5380-95/d35  
+--- Reference Line
+
+Figure B.15: Reference Line Alignment. A diagram showing a rectangular box containing text aligned to a vertical dashed reference line. The text inside the box is: 1,164, 1,872, 3,036, 9,391, 19,376, and 28,767. Below the box, a horizontal double-headed arrow indicates a distance of 240 units from the reference line to the right edge of the box. The reference line is labeled 'Reference Line' and 'ISO5380-95/d35'.
+
+**Figure B.15 – Reference Line  
+Alignment**
+
+The generic structures (see B.7.1 and B.7.4) and styles (see B.7.2 and B.7.3) specify that the content associated with a basic logical object belonging to the basic logical object class 2 0 0 0 or 2 0 0 1 shall be laid out within an entry frame which is aligned with other entry frames along a reference line.
+
+The same value of the layout directive attribute “block alignment point” is applied to the basic logical object classes 2 0 0 0 and 2 0 0 1. Since this value specifies the parameter “content dependent” with the value ‘applies’, the alignment points associated with those blocks within which the content of instances of the basic logical object classes is laid out are to be determined in accordance with the presentation style 5 0.
+
+The presentation style 5 0 includes the attribute “alignment point”, and the attribute specifies that the alignment point of a block to which this attribute applies shall locate on the first occurrence of the decimal point.
+
+The rest of this sub-clause is dedicated to explaining how the document and content layout process lay out the content of a basic logical object which is an instance of either the basic logical object class 2 0 0 0 or 2 0 0 1.
+
+When the content layout process formats the character content associate with the basic logical object concerned, the process finds the first occurrence of the decimal point, and exports the position of this occurrence within the block which the content layout process is generating. Conversely, the document layout process imports this position of the alignment point associated with the generated block.
+
+The block is placed within a lowest-level frame which is an instance of either the frame class 0 0 0 0 or 0 0 0 1. For these two frame classes, the attribute “frame alignment point” is specified so that the alignment point of their instance shall be located at the same position as that of the first block included in the instance.
+
+If the basic logical object concerned is an instance of the basic logical object class 2 0 0 0, then the document layout process positions the entry frame so that its alignment point, hence the first occurrence of the decimal point, shall be on a reference line.
+
+If the basic logical object is an instance of the basic logical object class 2 0 0 1, then the document layout process takes account of the attribute “indent – major” specified for the frame class 0 0 0 1. This attribute specifies the distance of the alignment point of the entry frame from the reference line. The distance is measured in the direction which intersects the major path of the immediately superior grid frame at right angles in an anticlockwise direction. Hence, since the specified value of the attribute “indent – major” is 240 SMU and the major path is downward, the entry frame is positioned so that its alignment point shall locate to the right of the reference line, and the distance of the alignment point from the reference line shall be 240 SMU.
\ No newline at end of file
diff --git a/marked/T/T-REC-T.422-199508-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/T/T-REC-T.422-199508-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..653de272961a40ec25eb914003b793fd98e8729e
--- /dev/null
+++ b/marked/T/T-REC-T.422-199508-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:6d4392fa7c206984f7665b03d9fdb25ee9fce6dbed29323bdc025668ca8fea2f
+size 8294
diff --git a/marked/T/T-REC-T.422-199508-I_PDF-E/d53cd0fd1cf896a9353fd63de1505ba2_img.jpg b/marked/T/T-REC-T.422-199508-I_PDF-E/d53cd0fd1cf896a9353fd63de1505ba2_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..d591e9521fe0a46258ca56836dc83aff492ecdb9
--- /dev/null
+++ b/marked/T/T-REC-T.422-199508-I_PDF-E/d53cd0fd1cf896a9353fd63de1505ba2_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:07c3be930e861079e7fcaa185a123cbba65fb663afa725f812c42732fb3f149c
+size 56301
diff --git a/marked/T/T-REC-T.424-199607-I_PDF-E/10781f43062bf3e9601a1e086710556c_img.jpg b/marked/T/T-REC-T.424-199607-I_PDF-E/10781f43062bf3e9601a1e086710556c_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..8dc08c1025e569d10112db8ee996cde2aac0b744
--- /dev/null
+++ b/marked/T/T-REC-T.424-199607-I_PDF-E/10781f43062bf3e9601a1e086710556c_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:7e466a6caee8afa20fbfc07245c13395739df093a05240eb8efb53ac06cbd3d5
+size 22129
diff --git a/marked/T/T-REC-T.424-199607-I_PDF-E/24a89bcaba787f2bc1721356480a4a01_img.jpg b/marked/T/T-REC-T.424-199607-I_PDF-E/24a89bcaba787f2bc1721356480a4a01_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..204a006c48b917bc7f2d1d922dd5840f6c067d07
--- /dev/null
+++ b/marked/T/T-REC-T.424-199607-I_PDF-E/24a89bcaba787f2bc1721356480a4a01_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:c38f35a177128fc268c9330bf7d29f57bf6212b5107b7dc4ef057f92920be14e
+size 44536
diff --git a/marked/T/T-REC-T.424-199607-I_PDF-E/2bacc162a73d75c43a7f90715832bd13_img.jpg b/marked/T/T-REC-T.424-199607-I_PDF-E/2bacc162a73d75c43a7f90715832bd13_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..69a758f1e88916bc34facb272ab66372b408cfa2
--- /dev/null
+++ b/marked/T/T-REC-T.424-199607-I_PDF-E/2bacc162a73d75c43a7f90715832bd13_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:888c7c08b9f3ab20551232e7992cffdf8ccf1d23e1b8b6004fd5d009788d8bd4
+size 181288
diff --git a/marked/T/T-REC-T.424-199607-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/T/T-REC-T.424-199607-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..85bf9991a879a04a36532e45641b6d9d89c6e137
--- /dev/null
+++ b/marked/T/T-REC-T.424-199607-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:ae1d050ffe78941af4f20bcaf940cb693e9a8434670cdd2a139a5542e54782ee
+size 8280
diff --git a/marked/T/T-REC-T.424-199607-I_PDF-E/32ff77da4286b58c4778033acaa10836_img.jpg b/marked/T/T-REC-T.424-199607-I_PDF-E/32ff77da4286b58c4778033acaa10836_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..8da550713b5ba104619610f4082b5d608524017b
--- /dev/null
+++ b/marked/T/T-REC-T.424-199607-I_PDF-E/32ff77da4286b58c4778033acaa10836_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:4397c2e8a56f1146a82878345682f02bc73ea0d593b5539b1acf2affd3499c79
+size 29726
diff --git a/marked/T/T-REC-T.424-199607-I_PDF-E/3c6151f296d5800335472b7dc00ce423_img.jpg b/marked/T/T-REC-T.424-199607-I_PDF-E/3c6151f296d5800335472b7dc00ce423_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..c957b79ca1ab8b52b75730dbaa3943281557a160
--- /dev/null
+++ b/marked/T/T-REC-T.424-199607-I_PDF-E/3c6151f296d5800335472b7dc00ce423_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:4cf9a7e670a78076265fcc4109ab7cc6ffab1dd0fc40ccd40b53bb46923b06b6
+size 37798
diff --git a/marked/T/T-REC-T.424-199607-I_PDF-E/41aef1f5efab13d4f38f69e86c726062_img.jpg b/marked/T/T-REC-T.424-199607-I_PDF-E/41aef1f5efab13d4f38f69e86c726062_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..95d8f3e776c2f552e706cdda64d5df6a508e6171
--- /dev/null
+++ b/marked/T/T-REC-T.424-199607-I_PDF-E/41aef1f5efab13d4f38f69e86c726062_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:669bfc1a43ca1c5fa6b78748a3da68a933f89a66c2c7dea15953ce3ddf47b9c2
+size 30524
diff --git a/marked/T/T-REC-T.424-199607-I_PDF-E/762a17cd79880dbca172bcbbe9375223_img.jpg b/marked/T/T-REC-T.424-199607-I_PDF-E/762a17cd79880dbca172bcbbe9375223_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..21910dc90021cfc0579591653f8dac6eed17d4fd
--- /dev/null
+++ b/marked/T/T-REC-T.424-199607-I_PDF-E/762a17cd79880dbca172bcbbe9375223_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:f0a1f144eb472598347f36fe013e8f72666da0b020d60546e235e4d95f9fe5e1
+size 20168
diff --git a/marked/T/T-REC-T.424-199607-I_PDF-E/7e61b2e2506cc7e5d6e16ce9c9df25bb_img.jpg b/marked/T/T-REC-T.424-199607-I_PDF-E/7e61b2e2506cc7e5d6e16ce9c9df25bb_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..ec8f0f5bc229b50ec0d41728be30bc884e5b3e5d
--- /dev/null
+++ b/marked/T/T-REC-T.424-199607-I_PDF-E/7e61b2e2506cc7e5d6e16ce9c9df25bb_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:1fb9a4e681c48fe3db19869b76e5a5fa9ed1a955ac1b7b984e2b7a50bddcd2b9
+size 46683
diff --git a/marked/T/T-REC-T.424-199607-I_PDF-E/844077b3034f0030b404207db0ad76b4_img.jpg b/marked/T/T-REC-T.424-199607-I_PDF-E/844077b3034f0030b404207db0ad76b4_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..95131b6abed6d42ae06344317290ef92b5d8a622
--- /dev/null
+++ b/marked/T/T-REC-T.424-199607-I_PDF-E/844077b3034f0030b404207db0ad76b4_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:a663b6ea52f25e3fa8d96818962355c6986e5a2e93c0095fa39bc72bcaeac026
+size 90514
diff --git a/marked/T/T-REC-T.424-199607-I_PDF-E/9edb407536d4d4d4a6ac391527af047c_img.jpg b/marked/T/T-REC-T.424-199607-I_PDF-E/9edb407536d4d4d4a6ac391527af047c_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..437c5307c327f848911edf68475e39101b710d43
--- /dev/null
+++ b/marked/T/T-REC-T.424-199607-I_PDF-E/9edb407536d4d4d4a6ac391527af047c_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:9c0b65506081dac86ae009d7d282a3d03595f4aa04cfbe4fc1051b23ab232ecc
+size 17377
diff --git a/marked/T/T-REC-T.424-199607-I_PDF-E/a0e8fe7862a6d7341faf5dac275277cc_img.jpg b/marked/T/T-REC-T.424-199607-I_PDF-E/a0e8fe7862a6d7341faf5dac275277cc_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..25e9aa074452884698fa01a51f42a35598235306
--- /dev/null
+++ b/marked/T/T-REC-T.424-199607-I_PDF-E/a0e8fe7862a6d7341faf5dac275277cc_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:8555cf86da80e190d063155ea07441bc1d447add8ad74c16092bdc7265b7deb6
+size 25398
diff --git a/marked/T/T-REC-T.424-199607-I_PDF-E/ae0a735d106290c594b0bafb1f5e72e7_img.jpg b/marked/T/T-REC-T.424-199607-I_PDF-E/ae0a735d106290c594b0bafb1f5e72e7_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..c0117bd7fc405b3318199576955bee6aaad5e0af
--- /dev/null
+++ b/marked/T/T-REC-T.424-199607-I_PDF-E/ae0a735d106290c594b0bafb1f5e72e7_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:16d59a4ac0cfb232acdd5a8b8a6472fddc7b0ec9c26d180b909efc83ad620464
+size 62285
diff --git a/marked/T/T-REC-T.424-199607-I_PDF-E/cfda9df1319e04207eb28bcefd1dab7b_img.jpg b/marked/T/T-REC-T.424-199607-I_PDF-E/cfda9df1319e04207eb28bcefd1dab7b_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..8c6b8457243be7fe64a054701a09e826d720ffbb
--- /dev/null
+++ b/marked/T/T-REC-T.424-199607-I_PDF-E/cfda9df1319e04207eb28bcefd1dab7b_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:c177c488bc655edc6dec13f35b5af34f2b8666e94b1d5be803d198b417c5433f
+size 80497
diff --git a/marked/T/T-REC-T.424-199607-I_PDF-E/dc23d430e878eb71b8cd589984113940_img.jpg b/marked/T/T-REC-T.424-199607-I_PDF-E/dc23d430e878eb71b8cd589984113940_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..2eb93df77dcca315d603c8bf049ddad10c04663b
--- /dev/null
+++ b/marked/T/T-REC-T.424-199607-I_PDF-E/dc23d430e878eb71b8cd589984113940_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:2bb5d4b94cbc31c38bbde206b6696a78300650fa4a8055fa2f33a7514bd1da9e
+size 12227
diff --git a/marked/T/T-REC-T.424-199607-I_PDF-E/e22af684d8e56d4c61e61bb5ddac1087_img.jpg b/marked/T/T-REC-T.424-199607-I_PDF-E/e22af684d8e56d4c61e61bb5ddac1087_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..5bdd21d81f80ec8fdd587d1c08cae1aab990b6b9
--- /dev/null
+++ b/marked/T/T-REC-T.424-199607-I_PDF-E/e22af684d8e56d4c61e61bb5ddac1087_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:c47d12a7135e22976f3e3e7f19e8823aaa59af676810134e4bf33a16333da175
+size 25700
diff --git a/marked/T/T-REC-T.424-199607-I_PDF-E/ec3647789b5c38fb686f2a0833324e79_img.jpg b/marked/T/T-REC-T.424-199607-I_PDF-E/ec3647789b5c38fb686f2a0833324e79_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..753ec79aea57d74f7826e1804e897687866a70d8
--- /dev/null
+++ b/marked/T/T-REC-T.424-199607-I_PDF-E/ec3647789b5c38fb686f2a0833324e79_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:02bd385334db431272ffe0ccfaf6193099e28ba57952ed65b6cb90b354baf3fe
+size 53109
diff --git a/marked/T/T-REC-T.424-199607-I_PDF-E/fc02903382cebe6fc11e4c0d74b5313f_img.jpg b/marked/T/T-REC-T.424-199607-I_PDF-E/fc02903382cebe6fc11e4c0d74b5313f_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..3bb73b7ae196f89dba696552516e02176382ae1a
--- /dev/null
+++ b/marked/T/T-REC-T.424-199607-I_PDF-E/fc02903382cebe6fc11e4c0d74b5313f_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:a5a89692c6eb6521e87bf042ec15d2156b90dd0a343cc0cfa5e72b94d67c9a77
+size 26322
diff --git a/marked/T/T-REC-T.424-199607-I_PDF-E/fd76efce549d3713543bb5ed9b023c2e_img.jpg b/marked/T/T-REC-T.424-199607-I_PDF-E/fd76efce549d3713543bb5ed9b023c2e_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..1a1241d56d5823a5024b0c6632f53007bf2c1205
--- /dev/null
+++ b/marked/T/T-REC-T.424-199607-I_PDF-E/fd76efce549d3713543bb5ed9b023c2e_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:834a520e86cb13a75c8c21350ad9559b92416df28a54c7ca3dbedbdc2960b7d2
+size 39600
diff --git a/marked/T/T-REC-T.424-199607-I_PDF-E/raw.md b/marked/T/T-REC-T.424-199607-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..005f9cebb52191ed41a678f5c3cd36a887f170eb
--- /dev/null
+++ b/marked/T/T-REC-T.424-199607-I_PDF-E/raw.md
@@ -0,0 +1,2707 @@
+
+
+![ITU logo: a globe with the letters ITU and a lightning bolt symbol.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg)
+
+ITU logo: a globe with the letters ITU and a lightning bolt symbol.
+
+INTERNATIONAL TELECOMMUNICATION UNION
+
+# ITU-T
+
+TELECOMMUNICATION  
+STANDARDIZATION SECTOR  
+OF ITU
+
+# T.424
+
+(07/96)
+
+SERIES T: TERMINAL EQUIPMENTS AND  
+PROTOCOLS FOR TELEMATIC SERVICES
+
+Terminals for telematic services
+
+---
+
+**Information technology – Open Document  
+Architecture (ODA) and interchange  
+format – Temporal relationships and  
+non-linear structures**
+
+ITU-T Recommendation T.424
+
+(Previously “CCITT Recommendation”)
+
+---
+
+# **ITU-T T-SERIES RECOMMENDATIONS** **TERMINAL EQUIPMENTS AND PROTOCOLS FOR TELEMATIC SERVICES**
+
+*For further details, please refer to ITU-T List of Recommendations.*
+
+# FOREWORD
+
+ITU (International Telecommunication Union) is the United Nations Specialized Agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the ITU. Some 179 member countries, 84 telecom operating entities, 145 scientific and industrial organizations and 38 international organizations participate in ITU-T which is the body which sets world telecommunications standards (Recommendations).
+
+The approval of Recommendations by the Members of ITU-T is covered by the procedure laid down in WTSC Resolution No. 1 (Helsinki, 1993). In addition, the World Telecommunication Standardization Conference (WTSC), which meets every four years, approves Recommendations submitted to it and establishes the study programme for the following period.
+
+In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. The text of ITU-T Recommendation T.424 was approved on 3rd of July 1996. The identical text is also published as ISO/IEC International Standard 8613-14.
+
+# --- NOTE
+
+In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+© ITU 1997
+
+All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU.
+
+# CONTENTS
+
+|                                                                                               | <i>Page</i> |
+|-----------------------------------------------------------------------------------------------|-------------|
+| 1 Scope .....                                                                                 | 1           |
+| 2 Normative references .....                                                                  | 2           |
+| 2.1 Identical Recommendations   International Standards .....                                 | 2           |
+| 2.2 Paired Recommendations   International Standards equivalent in technical content .....    | 2           |
+| 2.3 Additional references .....                                                               | 2           |
+| 3 Definitions .....                                                                           | 2           |
+| 4 Abbreviations .....                                                                         | 3           |
+| 5 Conventions .....                                                                           | 3           |
+| 6 Overview .....                                                                              | 3           |
+| 6.1 Constituents of the document structure .....                                              | 3           |
+| 6.2 Document profile attributes .....                                                         | 4           |
+| 6.2.1 Document profile attributes for temporal relationships .....                            | 4           |
+| 6.2.2 Document profile attributes for non-linear structures .....                             | 5           |
+| 6.3 Document sets .....                                                                       | 5           |
+| 7 Temporal relationships .....                                                                | 5           |
+| 7.1 Conceptual principles for temporal relationships .....                                    | 5           |
+| 7.1.1 Synchronization of presentations .....                                                  | 6           |
+| 7.1.2 Temporal characteristics .....                                                          | 6           |
+| 7.2 Attribute definitions for temporal relationships .....                                    | 6           |
+| 7.2.1 Temporal relations .....                                                                | 6           |
+| 7.2.2 Presentation time .....                                                                 | 8           |
+| 7.3 Reference model for the layout process with respect to temporal relationships .....       | 11          |
+| 7.4 Reference model for the presentation process with respect to temporal relationships ..... | 12          |
+| 7.4.1 Reference model for the temporal order of layout objects .....                          | 12          |
+| 7.4.2 Reference model for the processing of the presentation time specifications .....        | 13          |
+| 7.5 ASN.1 representations .....                                                               | 14          |
+| 8 Non-linear structures .....                                                                 | 15          |
+| 8.1 Structural model of a hypermedia document .....                                           | 15          |
+| 8.1.1 Nodes .....                                                                             | 16          |
+| 8.1.2 Links .....                                                                             | 16          |
+| 8.1.3 Link classes .....                                                                      | 16          |
+| 8.2 Descriptive representation of a hypermedia document .....                                 | 16          |
+| 8.3 Attribute definitions for links and link classes .....                                    | 17          |
+| 8.3.1 Link identifier .....                                                                   | 18          |
+| 8.3.2 Link class identifier .....                                                             | 18          |
+| 8.3.3 Link class .....                                                                        | 19          |
+| 8.3.4 Link roles .....                                                                        | 19          |
+| 8.3.5 Other attributes .....                                                                  | 20          |
+| 8.4 Attributes of the document profile .....                                                  | 21          |
+| 8.4.1 Entry point .....                                                                       | 21          |
+| 8.4.2 Links .....                                                                             | 21          |
+| 8.4.3 Link classes .....                                                                      | 21          |
+| 8.4.4 Enciphered links .....                                                                  | 21          |
+| 8.4.5 Pre-sealed document body parts .....                                                    | 21          |
+| 8.5 Structural model of a document set .....                                                  | 22          |
+| 8.5.1 Nodes .....                                                                             | 22          |
+| 8.5.2 Links .....                                                                             | 22          |
+| 8.5.3 Link classes .....                                                                      | 22          |
+| 8.5.4 Document set profile .....                                                              | 22          |
+
+|                                                                                               | <i>Page</i> |
+|-----------------------------------------------------------------------------------------------|-------------|
+| 8.6 Document set profile attributes .....                                                     | 22          |
+| 8.6.1 Entry point .....                                                                       | 24          |
+| 8.6.2 Links .....                                                                             | 24          |
+| 8.6.3 Link classes .....                                                                      | 24          |
+| 8.6.4 Enciphered links .....                                                                  | 24          |
+| 8.6.5 Pre-sealed document body parts .....                                                    | 24          |
+| 8.6.6 Document set characteristics .....                                                      | 24          |
+| 8.6.7 Other attributes .....                                                                  | 25          |
+| 8.6.8 References to documents .....                                                           | 26          |
+| 8.6.9 Security features .....                                                                 | 26          |
+| 8.7 Enciphered link part description .....                                                    | 26          |
+| 8.8 Reference model for the hypermedia document and document set editing process .....        | 26          |
+| 8.9 Reference model for the hypermedia document and document set layout process .....         | 27          |
+| 8.10 Reference Model for the hypermedia document and document set presentation process .....  | 27          |
+| 8.11 ASN.1 representations .....                                                              | 27          |
+| 8.11.1 Document set descriptor .....                                                          | 27          |
+| 8.11.2 Document set profile descriptor .....                                                  | 28          |
+| 8.11.3 Link descriptors .....                                                                 | 28          |
+| Annex A – Structuring conventions for "application comments" .....                            | 30          |
+| Annex B – Usage of the attribute/parameter "application comments" in links .....              | 31          |
+| B.1 Source role .....                                                                         | 31          |
+| B.2 Destination Role .....                                                                    | 31          |
+| B.3 Single-ended Role .....                                                                   | 31          |
+| B.4 Multi-ended Role .....                                                                    | 32          |
+| B.5 Automatic Invocation .....                                                                | 32          |
+| B.6 User Invocation .....                                                                     | 32          |
+| B.7 Link-Path-Selector .....                                                                  | 32          |
+| Annex C – Modifications to other common texts of ITU-T Rec. T.410-Series   ISO/IEC 8613 ..... | 33          |
+| C.1 Modifications to ITU-T Rec. T.411   ISO/IEC 8613-1 .....                                  | 33          |
+| C.1.1 Amendment for the assignment of ASN.1 object identifiers .....                          | 33          |
+| C.2 Modifications to ITU-T Rec. T.412   ISO/IEC 8613-2 .....                                  | 33          |
+| C.2.1 Amendment of the structural model .....                                                 | 33          |
+| C.2.2 Amendment of the processing model .....                                                 | 33          |
+| C.2.3 Amendment of attribute definitions .....                                                | 33          |
+| C.3 Modifications to ITU-T Rec. T.414   ISO/IEC 8613-4 .....                                  | 33          |
+| C.3.1 Document profile attributes for temporal relations .....                                | 33          |
+| C.3.2 Document profile attributes for non-linear structures .....                             | 33          |
+| C.4 Modifications to ITU-T Rec. T.415   ISO/IEC 8613-5 .....                                  | 34          |
+| C.4.1 Amendment of interchange data elements .....                                            | 34          |
+| C.4.2 Amendment of the document profile descriptor .....                                      | 34          |
+| C.4.3 Amendment of layout descriptors .....                                                   | 35          |
+| C.4.4 Amendment of logical descriptors .....                                                  | 35          |
+| Annex D – Examples for specifying temporal relationships .....                                | 36          |
+| Annex E – Compatibility with earlier editions of ITU-T Rec. T.410-Series   ISO/IEC 8613 ..... | 48          |
+| Annex F – Summary of ASN.1 object identifiers .....                                           | 49          |
+| Annex G – Application class tag assignments .....                                             | 50          |
+| Index .....                                                                                   | 51          |
+
+# Summary
+
+This Recommendation | International Standard is one of two (Recommendations T.422 and T.424) which are designed to support the interchange of processable and formatted hypermedia documents (HyperODA). The non-linear structures are required to enable an ODA document to be traversed in a non-linear fashion. It also supports the use of a temporal dimension in ODA documents as well as future non-spatially oriented content architectures .
+
+# Introduction
+
+This Recommendation | International Standard was prepared as a joint publication by ITU Study Group 8 and ISO/IEC Joint Technical Committee 1.
+
+At present, the ITU-T Rec. T.410-Series | ISO/IEC 8613 consists of:
+
+- Introduction and general principles;
+- Document structures;
+- Abstract interface for the manipulation of ODA documents;
+- Document profile;
+- Open document interchange format;
+- Character content architectures;
+- Raster graphics content architectures;
+- Geometric graphics content architectures;
+- Audio content architectures;
+- Formal Specification of the Open Document Architecture (FODA);  
+(The formal specification is applicable to ISO/IEC 8613 only.)
+- Tabular structures and tabular layout;
+- Identification of document fragments.
+
+Further Recommendations | International Standards may be added to this series of Recommendations | International Standards.
+
+Development of this series of Recommendations | International Standards was originally in parallel with the ECMA-101 standard: Open Document Architecture.
+
+This Recommendation | International Standard contains seven annexes:
+
+- Annex A (integral): Structuring conventions for "application comments";
+- Annex B (integral): Usage of the attribute/parameter "application comments" in links;
+- Annex C (integral): Modifications to other parts of ITU-T Rec. T.410-Series | ISO/IEC 8613;
+- Annex D (non-integral): Examples for specifying temporal relationships;
+- Annex E (non-integral): Compatibility with earlier editions of ITU-T Rec. T.410-Series | ISO/IEC 8613;
+- Annex F (non-integral): Summary of ASN.1 object identifiers;
+- Annex G (non-integral): Application class tag assignments.
+
+## INTERNATIONAL STANDARD
+
+## ITU-T RECOMMENDATION
+
+## **INFORMATION TECHNOLOGY – OPEN DOCUMENT ARCHITECTURE (ODA) AND INTERCHANGE FORMAT – TEMPORAL RELATIONSHIPS AND NON-LINEAR STRUCTURES**
+
+# **1 Scope**
+
+The purpose of the ITU-T Rec. T.410-Series | ISO/IEC 8613 is to facilitate the interchange of documents.
+
+In the context of these Recommendations | International Standards, documents are to be items such as memoranda, letters, invoices, forms and reports, which may include pictures and tabular material. The content elements used within the documents may include graphic characters, raster graphics elements and geometric graphics elements, all potentially within one document.
+
+NOTE – These Recommendations | International Standards are designed to allow for extensions, including hypermedia features, spreadsheets and additional types of content such as audio and video.
+
+In addition to the content types defined in these Recommendations | International Standards, ODA also provides for arbitrary content types to be included in documents.
+
+These Recommendations | International Standards apply to the interchange of documents by means of data communication or the exchange of storage media.
+
+These Recommendations | International Standards provide for the interchange of documents for either or both of the following purposes:
+
+- to allow presentation as intended by the originator;
+- to allow processing such as editing and reformatting.
+
+The composition of a document in interchange can take several forms:
+
+- formatted form, allowing presentation of the document;
+- processable form, allowing processing of the document;
+- formatted processable form, allowing both presentation and processing.
+
+These Recommendations | International Standards also provide for the interchange of ODA information structures used for the processing of interchanged documents.
+
+This Recommendation | International Standard:
+
+- extends the concepts of ODA beyond sheets of paper;
+- describes how to specify temporal relationships for the presentation of information in ODA documents such as sequential, parallel or cyclic presentation of particular pieces of information;
+- specifies a reference model for the layout process and presentation process in respect to temporal relationships;
+- introduces the concepts of hypermedia documents where non-linear links between presentable content are provided;
+- describes how to specify non-linear structures in an ODA document such as links between particular pieces of information as commonly found in so-called hypermedia documents;
+- introduces the concept of document sets;
+- defines a document set profile for document sets;
+- defines a reference model for the layout process and presentation process of hypermedia documents and document sets.
+
+# 2 Normative references
+
+The following Recommendations and International Standards contain provisions which, through reference in this text, constitute provisions of this Recommendation | International Standard. At the time of publication, the editions indicated were valid. All Recommendations and Standards are subject to revision, and parties to agreements based on this Recommendation | International Standard are encouraged to investigate the possibility of applying the most recent edition of the Recommendations and International Standards listed below. Members of IEC and ISO maintain registers of currently valid International Standards. The Telecommunication Standardization Bureau of the ITU maintains a list of currently valid ITU-T Recommendations.
+
+## 2.1 Identical Recommendations | International Standards
+
+- ITU-T Recommendation T.411 (1993) | ISO/IEC 8613-1:1994, *Information technology – Open Document Architecture (ODA) and interchange format: Introduction and general principles.*
+- ITU-T Recommendation T.412 (1993) | ISO/IEC 8613-2:1995, *Information technology – Open Document Architecture (ODA) and interchange format: Document structures.*
+- ITU-T Recommendation T.413 | ISO/IEC 8613-3:1995, *Information technology – Open Document Architecture (ODA) and interchange format: Abstract interface for the manipulation of ODA documents.*
+- ITU-T Recommendation T.414 (1993) | ISO/IEC 8613-4:1994, *Information technology – Open Document Architecture (ODA) and interchange format: Document profile.*
+- ITU-T Recommendation T.415 (1993) | ISO/IEC 8613-5:1994, *Information technology – Open Document Architecture (ODA) and interchange format: Open Document Interchange Format.*
+- ITU-T Recommendation T.416 (1993) | ISO/IEC 8613-6:1994, *Information technology – Open Document Architecture (ODA) and interchange format: Character content architectures.*
+- ITU-T Recommendation T.417 (1993) | ISO/IEC 8613-7:1994, *Information technology – Open Document Architecture (ODA) and interchange format: Raster graphics content architectures.*
+- ITU-T Recommendation T.418 (1993) | ISO/IEC 8613-8:1994, *Information technology – Open Document Architecture (ODA) and interchange format: Geometric graphics content architectures.*
+- ITU-T Recommendation T.419 (1995) | ISO/IEC 8613-9:1996, *Information technology – Open Document Architecture (ODA) and interchange format: Audio content architectures.*
+- ITU-T Recommendation T.421 (1994) | ISO/IEC 8613-11:1995, *Information technology – Open Document Architecture (ODA) and interchange format: Tabular structures and tabular layout.*
+- ITU-T Recommendation T.422 (1995) | ISO/IEC 8613-12 *Information technology – Open Document Architecture (ODA) and interchange format: Identification of document fragments.*
+
+## 2.2 Paired Recommendations | International Standards equivalent in technical content
+
+- CCITT Recommendation X.208 (1988), *Specification of Abstract Syntax Notation One (ASN.1).*  
+ISO/IEC 8824:1990, *Information technology – Open Systems Interconnection – Specification of Abstract Syntax Notation One (ASN.1).*
+
+## 2.3 Additional references
+
+- ISO/IEC 2022:1994, *Information technology – Character code structure and extension techniques.*
+- ISO 2375:1985, *Data processing – Procedure for registration of escape sequences.*
+- ISO 8601:1988, *Data elements and interchange formats – Information interchange – Representation of dates and times.*
+
+# 3 Definitions
+
+For the purposes of this Recommendation | International Standard, the definitions given in ITU-T Rec. T.411 | ISO/IEC 8613-1 apply, except those redefined here.
+
+The following additional definitions are used within this Recommendation | International Standard:
+
+- 3.1 block:** A basic layout component that corresponds to a rectangular area within a frame or page for presenting visual content of the document, a time span for presenting time varying content (such as audio content) of a document, or a combination thereof.
+- 3.2 document set:** A document set consists of a document set profile, an (optional) non-integral link part, and an (optional) set of documents or hypermedia documents.
+- 3.3 event:** Either an internal event or an external event.
+- 3.4 external event:** An event which is created by some mechanism external to the document, e.g. by user interaction.
+- 3.5 frame:** A composite layout component that corresponds to a rectangular area within a page or another frame for presenting visual content of the document, a time span for presenting time varying content (such as audio content) of a document, or a combination thereof.
+- 3.6 hypermedia document:** A hypermedia document is distinguished from a normal document by the presence of links.
+- 3.7 integral link:** A link that appears in the link part of the document description.
+- 3.8 internal event:** An event which is issued after a presentation of content is completed.
+- 3.9 link:** A set of information describing a relationship to or between one or more nodes.
+- 3.10 node:** Either a whole document or a document fragment.
+- 3.11 non-integral link:** A link that is separate from a particular document description and only appears in the link part of a document set description.
+- 3.12 page:** A layout component that corresponds to a rectangular area for presenting visual content of the document, a time span for presenting time varying content (such as audio content) of a document, or a combination thereof.
+- 3.13 scaled time unit:** A relative time unit whose mapping to a real time unit is defined by the document profile attribute "time scaling".
+
+# 4 Abbreviations
+
+For the purposes of this Recommendation | International Standard the abbreviations given in ITU-T Rec. T.411 | ISO/IEC 8613-1 apply.
+
+# 5 Conventions
+
+For the purposes of this Recommendation | International Standard the conventions given in ITU-T Rec. T.411 | ISO/IEC 8613-1 apply.
+
+# 6 Overview
+
+This clause provides an overview on the additional constituents and attributes which are added by this specification to the ITU-T Rec. T.410-Series | ISO/IEC 8613.
+
+## 6.1 Constituents of the document structure
+
+The following constituents are added to the ODA document structure as defined in ITU-T Rec. T.412 | ISO/IEC 8613-2:
+
+- link class descriptions;
+- link descriptions.
+
+NOTE – Enciphered link descriptions are included in pre-enciphered document body part descriptions. Seals for links or link classes are included in the document profile attribute "pre-sealed document body parts".
+
+Figure 2 in ITU-T Rec. T.412 | ISO/IEC 8613-2 is extended as follows (see Figure 1):
+
+![Figure 1 – Descriptive model of a document. The diagram shows a hierarchical structure of a document. At the top is 'Document description', which contains 'Document profile' and 'Sub-profile' (represented by a stack of three boxes). Below this is the 'Document body', which contains four main sections: 'Generic part', 'Style part', 'Specific part', and 'Protected part'. At the bottom of the 'Document body' is the 'Link part', which contains 'Link class description' (represented by a stack of three boxes) and 'Link description' (represented by a stack of three boxes). The entire structure is enclosed in a large rounded rectangle. The text 'TISO7410-96/d01' is located at the bottom right of the diagram.](cfda9df1319e04207eb28bcefd1dab7b_img.jpg)
+
+Figure 1 – Descriptive model of a document. The diagram shows a hierarchical structure of a document. At the top is 'Document description', which contains 'Document profile' and 'Sub-profile' (represented by a stack of three boxes). Below this is the 'Document body', which contains four main sections: 'Generic part', 'Style part', 'Specific part', and 'Protected part'. At the bottom of the 'Document body' is the 'Link part', which contains 'Link class description' (represented by a stack of three boxes) and 'Link description' (represented by a stack of three boxes). The entire structure is enclosed in a large rounded rectangle. The text 'TISO7410-96/d01' is located at the bottom right of the diagram.
+
+**Figure 1 – Descriptive model of a document**
+
+In addition to the attributes permitted for link descriptions and link class descriptions (see 8.3), the following attributes are added to the attributes defined in ITU-T Rec. T.412 | ISO/IEC 8613-2: "temporal relations", "presentation time".
+
+The following attributes are added to the attributes defined in ITU-T Rec. T.414 | ISO/IEC 8613-4: "document presentation time", "time scaling", "temporal relations", "links", "link classes".
+
+NOTE – Annex C contains additional details on the modifications to other parts of ITU-T Rec. T.410-Series | ISO/IEC 8613.
+
+## 6.2 Document profile attributes
+
+### 6.2.1 Document profile attributes for temporal relationships
+
+The following attributes are added to the document profile to support temporal relations in ODA documents.
+
+- "document presentation time;"
+- "time scaling";
+- "temporal relations".
+
+NOTE – The structure and semantics of these attributes are defined in C.3.1.
+
+### 6.2.2 Document profile attributes for non-linear structures
+
+The following attributes are added to the document profile to support non-linear structures in ODA documents:
+
+- "links";
+- "link classes";
+- "enciphered links".
+
+NOTE – The structure and semantics of these attributes are defined in Annex C.3.2.
+
+## 6.3 Document sets
+
+The concept of a document set consisting of a document set profile, an (optional) non-integral link part, and an (optional) set of documents or hypermedia documents is introduced. In this context, the constituent *document set profile* is introduced.
+
+# 7 Temporal relationships
+
+## 7.1 Conceptual principles for temporal relationships
+
+Each layout object (document layout root, page set, page, frame and block) has a position and dimension in time, i.e. a point in time – in addition to the spatial position and dimension that some layout objects (pages, frames, blocks) already have – at which the presentation of the content associated with the layout object starts, and a duration, specifying how long the presentation continues.
+
+NOTE 1 – Throughout this document terms such as "content associated with an object" or "content of an object" do not imply that the content is directly associated to the object. (Only basic objects can have directly associated content portions.) If these terms apply to a composite object, the content of content portions associated with all basic objects subordinate to the composite object is meant.
+
+In order to explain the synchronization of presentations, the concept of an *event* is introduced. An event is called an *internal event* if it is issued when the presentation of a particular piece of content is terminated because of time constraints specified in the document for that piece of content. The rules for the occurrence of events are defined in clause 7.1.1. An event is called an *external event* if it is created by some mechanism external to the document, e.g. the presentation of a particular piece of content may be terminated by user interaction.
+
+In general, an event is used to invoke the presentation of temporally succeeding content of the document. The temporal presentation of a document is usually controlled both by internal events and external events. For instance, the moving from one page to the next may be controlled by the external events of user interaction whereas the temporal presentation of the content on a particular page may be controlled by internal events.
+
+Layout objects may overlap in time, i.e. the presentation of the content associated with layout object X may start at the same time as the presentation of the content associated with layout object Y or at a point in time where the presentation of the content associated with layout object Y still continues.
+
+If it is required that on a particular area of a page different layout objects are presented at different points in time, this can be achieved by means of overlapping frames (see example 9 in Annex D).
+
+The duration for the presentation of the content associated with a layout object may be 0 time units, if the presentation of the content requires no time *per se* (e.g. the presentation of a portion of character text). In this case, an event may be issued immediately when the presentation of the content occurs.
+
+NOTE 2 – In practice, the rendition of content (e.g. the rendition of a character text portion on a computer screen) will always take some time depending on the processing speed of the hardware. However, from the conceptual point of view of the temporal relationships model, this time is assumed to be negligible.
+
+The temporal characteristics of the layout objects are defined by the attribute "presentation time" which applies to each layout object (directly or indirectly by means of the defaulting mechanism). In general, the values of these attributes can be determined during the layout process.
+
+With respect to the derivation of the values for the attribute "presentation time", the layout process takes account of the values of the attribute "temporal relations" which defines the temporal requirements of logical objects, and/or of the values of the attribute "presentation time" in the generic layout structure.
+
+### 7.1.1 Synchronization of presentations
+
+#### 7.1.1.1 Parallel presentations
+
+Two or more presentations are regarded as being carried out in parallel if those presentations are initiated at the same time, i.e. the presentations are carried out concurrently.
+
+Parallel presentations are sub-divided into the following three types:
+
+- *Parallel-last*: In this case, an event is issued when all the presentations in the set of presentations have terminated.
+- *Parallel-first*: In this case, an event is issued when any presentation in the set of presentations has terminated.
+- *Parallel-selective*: In this case, an event is issued when a specific presentation in the set of presentations has terminated.
+
+#### 7.1.1.2 Sequential presentations
+
+Two or more presentations are regarded as being sequential if the presentations occur one after the other so that one presentation cannot begin until another presentation has terminated. Thus the ending of a presentation is a pre-condition for starting another presentation.
+
+#### 7.1.1.3 Cyclic presentations
+
+A cyclic presentation is a presentation which is repeated more than once. The number of repetitions can be limited to a specified number or can be specified as being indefinite. In the case of a number, an event is issued when the presentation has been carried out the specified number of times.
+
+In the case of indefinite, it is assumed that an external event will terminate the cyclic presentation, or it is terminated because of time constraints which apply to superior objects. At the start of each cycle the presentation state is reset to the state which was in effect before the first cycle started in respect to the piece of content involved in the cycle (e.g. a computer screen will be cleared totally or in parts).
+
+NOTE – The effect of specifying that a presentation is cyclic means that the subordinate presentations, if any, which are processed in parallel or in sequence, are repeated as specified.
+
+### 7.1.2 Temporal characteristics
+
+Two types of temporal constraints can be specified for presentations, namely:
+
+- start time delays; and
+- duration constraints.
+
+A *start time delay* is a time delay which enables the actual start time of a presentation to be distinguished from the time at which the presentation is invoked. If no start time delay is specified, then the start time of the presentation and the invocation time are coincident.
+
+The *duration constraint* specifies the time for which a presentation is to continue. If no duration is explicitly specified, then no constraints are applicable to the time for which the presentation is to continue. In this case, it depends on the nature of the content when an event will be issued. That is, an event will be issued as soon as the presentation of the content is finished. (For instance, for character content this will be immediately, for audio content this will be at that point in time when the audio content has been presented.)
+
+The above time constraints for a start time and a duration can also be specified for each cycle and a constraint can be specified for the maximum time for each cycle.
+
+## 7.2 Attribute definitions for temporal relationships
+
+Temporal relationships in a document are specified by the attributes "temporal relations" and "presentation time".
+
+### 7.2.1 Temporal relations
+
+The attribute "temporal relations" is classified as a logical attribute.
+
+#### Constituents
+
+Logical document root component descriptions and composite logical object component descriptions.
+
+##### **Classification**
+
+- non-mandatory for object class descriptions;
+- defaultable for object descriptions.
+
+##### **Structure**
+
+The value of the attribute is either 'null' or it consists of the two parameters "synchronization type" and "subordinate nodes".
+
+The parameter "subordinate nodes" is structured into a sequence of entries where each entry consists of the sub-parameters "node identifier" and, optionally, "cyclic", "duration", "start time", "end time" and "application comments".
+
+The sub-parameter "cyclic" is structured into the sub-sub-parameters "number of cycles" and, optionally, "cycle duration" and "cycle start time".
+
+##### **Permissible values**
+
+For the parameter "synchronization type": either 'parallel first', 'parallel last', 'parallel selective' or 'sequential'.
+
+For the sub-parameter "node identifier":
+
+If the attribute is specified for an object class: A sequence of non-negative integers representing an object class identifier which appears in the value of the attribute "generator for subordinates" specified for the object class.
+
+If the attribute is specified for an object: A sequence of non-negative integers representing an object identifier which is immediately subordinate to the object for which the attribute is specified.
+
+For the sub-sub-parameter "number of cycles": Either 'indefinite' or a positive integer.
+
+For the sub-parameters "start time" and "end time" and the sub-sub-parameter "cycle start time": A non-negative integer.
+
+For the sub-parameter "duration" and sub-sub-parameter "cycle duration": Either 'indefinite' or a non-negative integer.
+
+For the sub-parameter "application comments": An octet string with a sub-structure as defined in Annex A.
+
+##### **Default value**
+
+- 'null'.
+
+##### **Definition**
+
+This attribute specifies temporal relations for the presentation of content that is associated with objects immediately subordinate to the object for which the attribute is specified.
+
+A value of 'null' indicates that no temporal relations are specified for the presentation of the content of the immediately subordinate objects.
+
+If the attribute is inherited from a class and its value is not 'null', the values of the sub-parameters "node identifier" (which are object class identifiers) are replaced by object identifiers of those objects which are immediately subordinate to the object which inherits the attribute, and which refer to the respective class. The value of the attribute "generator for subordinates" of the class shall be chosen such that it ensures a unique correspondence between such objects and the object classes referred to by the sub-parameters "node identifier".
+
+The parameter "synchronization type" whose value is either 'parallel first', 'parallel last', 'parallel selective' or 'sequential', specifies the type of synchronization mechanism that is to be applied to the content of the objects identified by the sub-parameters "node identifier" of the parameter "subordinate nodes". That is, this parameter specifies whether the content associated with the subordinate objects is to be presented in parallel or in sequence. In the case of parallel, this parameter indicates whether the synchronization is to be 'parallel-last', 'parallel-first' or 'parallel-selective' as defined in 7.1.1.1.
+
+The parameter "subordinate nodes" specifies the list of subordinate objects whose content is involved in the synchronization process and, optionally, additional presentation constraints which apply to an individual object.
+
+NOTE – The sub-parameter "node identifier" refers to objects or object classes within the same document. If temporal relationships shall be specified for object or object classes which reside in a document fragment separate from the current document, dummy objects or dummy object classes are inserted into the document which act as placeholders for the resolution process as defined by the inclusion rules for distributed documents.
+
+The order of specification of the node identifiers is significant when the synchronization type is 'sequential' or 'parallel selective'. In the case of 'sequential', the content associated with the objects is intended to be presented in the order indicated. In the case of 'parallel selective', the first object specified is the nominated selective node.
+
+The (optional) sub-parameter "start time" specifies the time delay between the invocation of the presentation of the content of the subordinate object and the actual start time at which the content is presented. If the sub-parameter is not specified, invocation time and start time are coincident.
+
+The (optional) sub-parameter "end time" specifies the time delay between the actual time at which the presentation of the content of the subordinate object finishes and the time at which an event is issued.
+
+The (optional) sub-parameter "duration" defines a constraint on the time for which the presentation of the content of an object occurs. If the sub-parameter is not specified, an event is issued with the delay of "end time", if specified, after the presentation of the content, taking account of a possibly specified start time. If the value 'indefinite' is specified, the presentation of the content of the object may continue indefinitely, i.e. until the process is terminated by an external event, by the time constraints specified by the sub-parameter "cyclic" for this object, or by time constraints applying to superior objects.
+
+The (optional) sub-parameter "cyclic" specifies whether or not the content of the object is to be presented more than once. If the sub-parameter is not specified, presentation takes place once. This sub-parameter shall only be specified for objects whose content requires a positive amount of time for presentation, either because of the nature of the content such as audio content or because the sub-sub-parameters "cycle duration" and/or "cycle start time" are specified with a positive value.
+
+The sub-sub-parameter "number of cycles" of the sub-parameter "cyclic" specifies the number of times that the content of the object is to be presented. The value of 'indefinite' indicates that cycles may be repeated indefinitely, i.e. until terminated by an external event, by the time constraints specified by the sub-parameter "duration" for this object, or by time constraints applying to superior objects.
+
+The (optional) sub-sub-parameter "cycle start time" of the sub-parameter "cyclic" specifies the time delay between the invocation of each cycle and the actual start time of each cycle. If the sub-sub-parameter is not specified, a value of 0 (zero) is assumed.
+
+The (optional) sub-sub-parameter "cycle duration" of the sub-parameter "cyclic" defines a constraint on the time for which the cycles may continue to be processed. If the sub-sub-parameter is not specified, a value of 0 (zero) is assumed. If the value 'indefinite' is specified, the cyclic presentation of the content of the object may continue indefinitely, i.e. until the process is terminated by an external event or by other temporal constraints applying to the object.
+
+If the sub-parameter "duration" and the sub-parameter "cyclic" are specified, the sub-parameter "duration" takes precedence over "cyclic", i.e. the cyclic processing of the content associated with the object will be terminated after the number of time units given by the sub-parameter "duration", even if the processing specifications given by the sub-parameter "cyclic" are not yet satisfied.
+
+The sub-parameter "application comments" may be used to specify the semantics of the value 'indefinite' for the sub-parameter "duration". This sub-parameter has no significance for the reference models of the layout or imaging/presentation processes defined in ITU-T Rec T.412 | ISO/IEC 8613-2, nor for any content layout or imaging/presentation processes defined in this Recommendation | International Standard or other common texts of ITU-T Rec. T.410-Series | ISO/IEC 8613.
+
+All time specifications are given in scaled time units.
+
+For the determination of the value of the attribute, steps a), c), e) and j) as in 9.1.2.4 of ITU-T Rec. T.412 | ISO/IEC 8613-2 are applicable.
+
+### 7.2.2 Presentation time
+
+The attribute "presentation time" is classified as a layout attribute.
+
+#### Constituents
+
+Layout component descriptions.
+
+#### Classification
+
+- non-mandatory for object class descriptions;
+- defaultable for object descriptions.
+
+#### Structure
+
+The value of the attribute is either 'null' or it is structured into the optional parameters "timing", "duration", "cyclic" and "application comments". At least one parameter must be specified unless the value is 'null'.
+
+The parameter "timing" consists either of the sub-parameter "fixed timing" or the sub-parameter "variable timing".
+
+The parameter "duration" consists of one of the sub-parameters "fixed duration", "rule A" or "rule B".
+
+The parameter "cyclic" is structured into the sub-parameters "number of cycles" and, optionally, "cycle duration" and "cycle start time".
+
+The sub-parameter "variable timing" consists of one or more of the optional sub-sub-parameters "start offset", "end offset", "start separation" or "end separation".
+
+The sub-parameters "rule A" and "rule B" may specify the (optional) sub-sub-parameters "minimum duration" and/or "maximum duration".
+
+#### Permissible values
+
+For the parameter "application comments": An octet string with a sub-structure as defined in Annex A.
+
+For the sub-parameter "fixed timing": A non-negative integer.
+
+For the sub-parameter "fixed duration": Either 'indefinite', a non-negative integer or a sequence of non-negative integers representing an identifier of a layout object. The identifier of a layout object shall not be specified if the attribute is specified for an object class.
+
+For the sub-parameter "number of cycles": Either 'indefinite' or a positive integer.
+
+For the sub-parameter "cycle start time": A non-negative integer.
+
+For the sub-parameter "cycle duration": Either 'indefinite' or a non-negative integer.
+
+For the sub-sub-parameters "start offset", "end offset", "start separation", "end separation", "minimum duration" and "maximum duration": A non-negative integer.
+
+##### Default value
+
+- 'null'.
+
+##### Definition
+
+This attribute specifies the position and dimension in time for the presentation of the content of the layout object for which the attribute is specified.
+
+If the value of the attribute is 'null', no constraints are specified for the temporal presentation of the content of the layout object.
+
+Two cases for "timing" are to be considered: That of specifying the sub-parameter "fixed timing" and that of specifying the sub-parameter "variable timing".
+
+In the case of fixed timing, the value of the sub-parameter "fixed timing" specifies the time delay between the start of the presentation of its immediately superior object and the start of the presentation of the object itself.
+
+The sub-parameter "variable timing" may only be specified for frame class descriptions that are referred to in construction expressions only from other frame class descriptions. All other layout components, in particular, all specific layout objects, may only specify the sub-parameter "fixed timing".
+
+In the case of variable timing, one or more of the sub-sub-parameters "start offset", "end offset", "start separation" or "end separation" may be specified whose semantics are as follows (the specifications given by these sub-sub-parameters are rules for the temporal layout process to determine the values of the attributes "presentation time" for layout objects created during the layout process):
+
+- the sub-sub-parameter "start offset" specifies the minimum delay between the start of the presentation of a frame belonging to this frame class and the start of the presentation of its immediately superior frame;
+- the sub-sub-parameter "end offset" specifies the minimum delay between the end of the presentation of a frame belonging to this frame class and the end of the presentation of its immediately superior frame;
+- the sub-sub-parameter "start separation" specifies the minimum delay between the start of the presentation of a frame belonging to this frame class and the end of the presentation of that frame which is immediately preceding in sequential layout order;
+- the sub-sub-parameter "end separation" specifies the minimum delay between the end of the presentation of a frame belonging to this frame class and the start of the presentation of that frame which is immediately succeeding in sequential layout order.
+
+Two cases for "duration" are to be considered: That of specifying the sub-parameter "fixed duration" and that of specifying the sub-parameters "rule A" or "rule B".
+
+The sub-parameter "fixed duration" defines a constraint on the time for which the content of an object may continue to be presented. If the sub-parameter is not specified, an event is issued immediately after the presentation of the content, taking account of the value of the parameter "timing", if specified. If the value 'indefinite' is specified by, the presentation of the content may continue indefinitely, i.e. until the process is terminated by an external event or by time constraints applying to superior objects. If a non-negative integer is specified, it defines the number of scaled time units for the presentation of the content of the object. If a layout identifier is specified, it indicates that the presentation of the content of the object shall terminate at the same time as the presentation of the content of the referenced object terminates. A layout identifier shall not be specified at the document layout root level.
+
+NOTE – The sub-parameter "fixed-duration" (when referencing a layout object) may refer only to objects in the same document. If a reference shall be made to an object which resides in a document fragment separate from the current document, a dummy object is inserted into the document which acts as a placeholder for the resolution process as defined by the inclusion rules for distributed documents.
+
+The sub-parameters "rule A" or "rule B" may only be specified for frame class descriptions that are referred to in construction expressions only from other frame class descriptions. All other layout components, in particular, all specific layout objects, may only specify the sub-parameter "fixed duration".
+
+The specifications given by these sub-parameters "rule A" or "rule B" are rules for the temporal layout process to determine the values of the attributes "presentation time" for layout objects created during the layout process. Their semantics is as follows:
+
+- The sub-parameter "rule A" specifies that the duration of the presentation of a frame belonging to this frame class shall be the minimum duration necessary for the presentation of that immediately subordinate frame or block which contains content that is earliest in sequential logical order.
+- The sub-parameter "rule B" specifies that the duration of the presentation of a frame belonging to this frame class shall be the minimum duration necessary for the presentation of all immediate subordinate frames or blocks.
+- The sub-sub-parameters "minimum duration" and "maximum duration" may specify additional constraints for the durations determined by the respective rule. If the value determined by the rule would otherwise be smaller than the value specified by "minimum duration", then the value of "minimum duration" takes precedence. If the value determined by the rule would otherwise be larger than the value specified by "maximum duration", then the value of "maximum duration" takes precedence.
+
+The (optional) parameter "cyclic" specifies whether or not the content of the object is to be presented more than once. If the parameter is not specified, processing takes place once. This parameter shall be specified only for objects whose content requires a positive amount of time for presentation, either because of the nature of the content such as audio content or because the sub-parameters "cycle duration" and/or "cycle start time" are specified with a positive value.
+
+The sub-parameter "number of cycles" of the parameter "cyclic" specifies the number of times that the content of the object is to be presented. The value 'indefinite' indicates that cycles may be repeated indefinitely, i.e. until terminated by an external event, by the time constraints specified by the parameter "duration" for this object, or by time constraints applying to superior objects.
+
+The (optional) sub-parameter "cycle start time" of the parameter "cyclic" specifies the time delay between the invocation of each cycle and the actual start time for each cycle. If the sub-parameter is not specified, a value of 0 (zero) is assumed.
+
+The (optional) sub-parameter "cycle duration" of the parameter "cyclic" defines a constraint on the time for which the cycles may continue to be processed. If the sub-parameter is not specified, a value of 0 (zero) is assumed. If the value 'indefinite' is specified, the cyclic presentation of the content of the object may continue indefinitely, i.e. until the process is terminated by an external event or by other temporal constraints applying to the object.
+
+If the parameter "duration" and the parameter "cyclic" are specified, the parameter "duration" takes precedence over "cyclic", i.e. the cyclic processing of the content associated with the object will be terminated after the number of time units given by the parameter "duration", even if the processing specifications given by the parameter "cyclic" are not yet satisfied.
+
+The parameter "application comments" may be used to specify the semantics of the value 'indefinite' for the sub-parameter "fixed duration". This sub-parameter has no significance for the reference models of the layout or imaging/presentation processes defined in ITU-T Rec T.412 | ISO/IEC 8613-2, nor for any content layout or imaging/presentation processes defined in this Recommendation | International Standard or other common texts of ITU-T Rec T.410-Series | ISO/IEC 8613.
+
+All time specifications are given in scaled time units.
+
+The point in time at which the event associated with the presentation of the content of the layout object is issued is determined by the parameters specified according to the following rules.
+
+Let
+
+- $t_0$  be the number of time units for the presentation of the content of the layout object without taking account of the specifications of the attribute "presentation time", e.g.  $t_0$  will be 0 for content types such as character text or raster graphics;
+- $t_1$  be the number of time units specified by the sub-parameter "fixed timing";
+- $t_2$  be the number of time units specified by the sub-parameter "fixed duration" which may be 'indefinite', or the time at which the object referenced by the sub-parameter "fixed duration" issues an event;
+- $t_3$  be the number of time units required for the cyclic processing of the content as specified by the parameter "cyclic" which may be 'indefinite'.
+
+Table 1 indicates the point in time – relative to the presentation time of the immediately superior object – at which the event occurs for each possible combination of parameters. (If the value of the attribute is 'null', an event will be issued at  $t_0$ .)
+
+**Table 1 – Temporal occurrence of events depending on the specified (sub-) parameter(s)**
+
+| Fixed timing ( $t_1$ ) | Fixed duration ( $t_2$ ) | Cyclic ( $t_3$ ) | Event at    |
+|------------------------|--------------------------|------------------|-------------|
+| –                      | –                        | –                | $t_0$       |
+| +                      | –                        | –                | $t_0 + t_1$ |
+| –                      | +                        | ?                | $t_2$       |
+| +                      | +                        | ?                | $t_1 + t_2$ |
+| –                      | –                        | +                | $t_3$       |
+| +                      | –                        | +                | $t_1 + t_3$ |
+
+A "+" in this table indicates that the parameter is specified, a "–" that it is not specified and a "?" that it may be specified but has no effect on the time at which the event is issued.
+
+If in a sum of time values any one of the operands is 'indefinite', the sum shall have the value 'indefinite', i.e. the presentation of the content will continue until an external event occurs or it may terminate because of temporal constraints which apply to superior layout objects.
+
+External events take precedence over specifications given by the attribute "presentation time", i.e. an external event such as a user interaction always terminates the presentation of the content associated with a layout object, even if, e.g. the time given by the sub-parameter "fixed duration" has not yet expired. The effect of external events is considered implementation-dependent.
+
+For the determination of the value of the attribute, steps a), c), e) and j) as in 9.1.2.4 of ITU-T Rec. T.412 | ISO/IEC 8613-2 are applicable.
+
+## 7.3 Reference model for the layout process with respect to temporal relationships
+
+The reference model of the layout process as described in ITU-T Rec. T.412 | ISO/IEC 8613-2 is extended as follows. The extended layout process:
+
+- consists of the generation of a specific layout structure and the layout of the content of basic logical objects; during this process, the basic logical objects are considered in accordance with their sequential order (as it is);
+- controls the allocation of the time spans and the (spatial) areas at the same time as described in this subclause.
+
+The specifications of temporal relations become effective during the presentation (imaging) process. It is the task of the layout process, to transfer the temporal relationship specifications encountered in the logical structure by means of the attribute "temporal relations" or specifications in the generic layout structure to the layout objects created by the layout process.
+
+In particular, if temporal relations are specified for the content associated with logical objects, the layout objects with which the content will be associated, have to reflect these relations, i.e. the layout process has to add one or more of the attributes "presentation time" with appropriate values for the parameters and sub-parameters to suitable objects in the layout structure.
+
+NOTE 1 – The layout process need not add the attribute "presentation time" explicitly to a specific layout object. Nevertheless, specifications for the temporal presentation of such a layout object may apply if the layout object class to which the layout object belongs contains such specifications. For instance, no temporal relations may be specified within the logical structure of a document, but the generic layout structure may specify, by means of the attribute "presentation time", that each page is to be presented for a specified amount of time after which the next page will be presented automatically.
+
+The document layout process and the content layout process interact as follows: The document layout process informs the content layout process about the available time span (in addition to the available area) which the content layout process may consume. (The available time span may be infinite.) The content layout process informs the document layout process about the required time span it needs for laying out the content. (The required time span may be 0 time units.) If the available time span is smaller than the required time span, the content layout process fails. In this case, the document layout process may try to find a larger available time span, e.g. by starting a new page, and initiate the content layout process again.
+
+NOTE 2 – The spatial layout process and the temporal layout process are separate processes. In particular, the specifications of the attributes "temporal relations" and "presentation time" have no direct implications for the spatial content layout process. However, the spatial layout process and the temporal layout process may interact, e.g. specifications for the temporal layout process may influence the spatial layout process (see example 8 in Annex D).
+
+NOTE 3 – The distinction between the document layout process and the content layout process conforms to the reference model for the layout process described in ITU-T Recommendation T.412 (1993) | ISO/IEC 8613-2:1995. In an actual implementation there may not exist such a distinction.
+
+If concatenation of content occurs, i.e. the content associated with a basic logical object is concatenated with the content of one or more other basic logical objects, only the specification of the attribute "temporal relations" for the first basic logical object, if present, is taken into account; specifications for the other basic logical objects, if present, are ignored.
+
+If the content of one basic logical object is split into several layout objects, the effect of how the temporal specifications are applied to the individual layout objects is considered application dependent. Individual content architectures may specify additional rules for this case.
+
+NOTE 4 – Unresolvable constraints for the temporal presentation of a document are possible. For instance, the constraint that the content of two logical objects A and B shall be presented in parallel may not be resolvable if the content of A and B does not fit on one page. This specification assumes that all constraints can be satisfied; the specification does not define how to handle unresolvable constraints.
+
+## 7.4 Reference model for the presentation process with respect to temporal relationships
+
+The specifications of the attribute "presentation time" encountered in the layout structure are ignored if the concept of time is not supported (e.g. by a printer). If in such a case the content of a particular area on the presentation medium changes with time (e.g. the content portions to be imaged within one particular block are different at time  $t_1$  and  $t_2$ ), the result is considered implementation-dependent. It is recommended that this feature (see example 8 in Annex D on time-varying content in overlapping frames) shall be used only in conjunction with alternative representations.
+
+The following specifications apply only if the concept of time is supported, e.g. by a computer screen connected to a computer system with a built-in clock.
+
+### 7.4.1 Reference model for the temporal order of layout objects
+
+Each layout object has a unique position in time on an abstract (discrete and finite) time axis which corresponds to the position in the sequential layout order of the specific layout structure. Since this position in time is specified implicitly by the sequential layout order, it is called the *implicit time coordinate* of the layout object.
+
+![A diagram showing a horizontal time axis with tick marks. Above the axis, labels indicate sequential order: 1st, 2nd, 3rd, 4th, 5th, 6th, and last. Below the axis, corresponding numerical coordinates are shown: 1, 2, 3, 4, 5, 6, and n. A dashed line indicates a break between 6 and n/last.](dc23d430e878eb71b8cd589984113940_img.jpg)
+
+Layout objects in sequential layout order
+
+```
+
+graph LR
+    subgraph "Layout objects in sequential layout order"
+    A[1st] --- B[2nd] --- C[3rd] --- D[4th] --- E[5th] --- F[6th] -.- G[last]
+    end
+    subgraph "Implicit time coordinate"
+    1 --- 2 --- 3 --- 4 --- 5 --- 6 -.- n
+    end
+
+```
+
+TISO7420-96/d02
+
+A diagram showing a horizontal time axis with tick marks. Above the axis, labels indicate sequential order: 1st, 2nd, 3rd, 4th, 5th, 6th, and last. Below the axis, corresponding numerical coordinates are shown: 1, 2, 3, 4, 5, 6, and n. A dashed line indicates a break between 6 and n/last.
+
+During the presentation process each point on the implicit time axis is mapped to a point on the (discrete and finite) *presentation time axis*, i.e. each layout object receives a *presentation time coordinate* for its invocation. In addition, each layout object receives a presentation time coordinate for its termination which is always greater than the presentation time coordinate for its invocation. That is, each implicit time coordinate is mapped to two presentation time coordinates representing a presentation time interval in which the presentation of the object associated with the implicit time coordinate takes place. This is done according to the following rules:
+
+- Each presentation time coordinate represents a point in time where a presentation starts or an event occurs.
+- All presentation time coordinates are determined by values of the attribute "presentation time" specified (or defaulted) for the layout objects.
+- If object X is superior to object Y, the presentation time coordinate for object X must be less than or equal to the one for object Y, i.e. a subordinate object may not be presented earlier than its superior object.
+
+NOTE – The following example shows a mapping from implicit time coordinates to presentation time coordinates.
+
+![Diagram showing the mapping from implicit time coordinates to presentation time coordinates. A horizontal timeline at the bottom is marked with points 1 through 10. Above this timeline, various horizontal brackets represent the duration of objects 1 through 10. Object 1: from 1 to 2; Object 2: from 1 to 2; Object 3: from 1 to 2; Object 4: from 3 to 6; Object 5: from 3 to 4; Object 6: from 3 to 6; Object 7: from 5 to 8; Object 8: from 7 to 10; Object 9: from 7 to 8; Object 10: from 9 to 10.](10781f43062bf3e9601a1e086710556c_img.jpg)
+
+Implicit time coordinates
+
+Presentation time coordinates
+
+TISO7430-96/d03
+
+Diagram showing the mapping from implicit time coordinates to presentation time coordinates. A horizontal timeline at the bottom is marked with points 1 through 10. Above this timeline, various horizontal brackets represent the duration of objects 1 through 10. Object 1: from 1 to 2; Object 2: from 1 to 2; Object 3: from 1 to 2; Object 4: from 3 to 6; Object 5: from 3 to 4; Object 6: from 3 to 6; Object 7: from 5 to 8; Object 8: from 7 to 10; Object 9: from 7 to 8; Object 10: from 9 to 10.
+
+The layout objects associated with the implicit time coordinates may be: 1: page; 2 and 3: blocks with character text subordinate to the page; 4: page; 5: object with audio content; 6: block with graphics content which is to be presented in parallel with 5; 7: object with audio content which is to be presented after 5 and whose presentation is to terminate when the presentation of 9 terminates; 8: page; 9 and 10: blocks which are to be presented in sequence.
+
+During the presentation process each presentation time coordinate  $i$  is further mapped to a point  $t_i$  in real time. In general, this mapping is only defined partially by the document. For instance, it may be undefined when the presentation of a particular page in a document starts, because moving from one page to the next may require user interaction. However, the presentation of the objects on a page in real time may be defined completely, by means of the attribute "presentation time", as soon as the presentation of the page itself is initiated.
+
+The presentation time coordinates are mapped uniquely to real time coordinates in ascending order, i.e. each presentation time coordinate  $i$  is mapped to exactly one real time coordinate  $t_i$  and  $t_i < t_j$  for  $i < j$ .
+
+### 7.4.2 Reference model for the processing of the presentation time specifications
+
+Temporal relations become effective during the presentation of a document. In particular, all specifications for the presentation of the content of a document in temporal order are given by the attribute "presentation time" specified for the document layout root, page set, page, frame and block components in the layout structure of a document.
+
+If no presentation order is specified explicitly in the layout structure or in a substructure thereof (i.e. the default value as defined in 7.2.2 applies to each layout object), the document is presented in the following temporal order:
+
+- The presentation of the document is started by an external event, e.g. by a user request to present the document.
+- The pages of the document are presented in that order in which they appear in the sequential layout order.
+- Only one page is presented at any point in time.
+- The temporal presentation of all content of the objects on a particular page occurs in parallel.
+
+- Content which does not change with time is presented as long as the page itself is presented (e.g. the content of a block with character text will be visible as long as the page itself).
+- After the termination of the presentation of content which changes with time, the presentation of this content will continue in that state that was reached at its end as long as the page is presented (e.g. for audio content nothing will be perceivable, for video content the final picture of the video – which may be blank – will be visible).
+- The presentation of a page is terminated by an external event (e.g. by user interaction), i.e. the duration is indefinite.
+
+NOTE 1 – A particular implementation may provide additional features for the presentation of a document such as starting the presentation of a document at an arbitrary page number or skipping backwards through the pages of a document. However, the effect of such additional features for the reference model described in this subclause is considered implementation-dependent, e.g. each time a layout object is presented the presentation time coordinate could be started at that point.
+
+If explicit specifications for the presentation order are present, the following rules apply:
+
+- The presentation of a document may start automatically or on the occurrence of an external event (e.g. user interaction) depending on the value of the attribute "document presentation time" in the document profile (see C.3.1). If the attribute is specified, the presentation of the document will start automatically when the specified date and time is reached. Otherwise, the presentation of the document will not start automatically.
+- Whenever the presentation of the content of a layout object is invoked, the presentation process determines that point in time at which the event belonging to the presentation will be issued, according to the rules specified in 7.2.2.
+- Furthermore, whenever the presentation of the content of a composite layout object (i.e. the document layout root, a page set, a page or a frame) is invoked, the presentation time coordinates of its immediately subordinate objects are determined. The presentation coordinate for starting the presentation of the content of an object is either defined by the sequential layout order or by the parameter "invocation time" of the attribute "presentation time", if specified. The presentation time coordinate for terminating the presentation of the content of an object is either defined by the temporal nature of the content or by duration constraints defined by the parameters "duration" or "cyclic" of the attribute "presentation time", if specified.
+- If the sub-parameter "fixed timing" is specified for an object with a value of  $s$ , it is invoked for presentation  $s$  scaled time units after its immediately superior objects started its presentation.  
+NOTE 2 – In particular, this parameter may be used to start the synchronous presentation of the content of two or more objects.
+- If the parameter "duration" and the sub-parameter "cycle duration" are not specified, content which does not change with time is presented as long as the content of the superior frame or page is presented (e.g. the content of a block with character text remains visible as long as the superior frame or page itself).
+- If the sub-parameter "fixed duration" is specified for an object with a integer value of  $s$ , the content of the object is presented for  $s$  scaled time units after the presentation of the content started. If the identifier of a layout object is specified, the presentation of the content of the object continues as long as the content of the referenced layout object is presented.
+- If the sub-parameter "fixed duration" or the sub-parameter "cycle duration" of the parameter "cyclic" is specified, the content will no longer be perceivable after the specified time span has expired, e.g. audio content will no longer be heard, visual content such as character text will no longer be visible.
+- The presentation of the content of an object which a position and dimension in space does not continue when the presentation of its immediately superior object terminates (e.g. the content of a block cannot be visible when the time span for its superior frame has expired).
+
+NOTE 3 – This restriction does not apply for blocks for which the value of the attributes "position" and "dimension" is 'null' such as for blocks with audio content. The content of such blocks may still be presented even if the frames or pages to which these blocks are subordinate are no longer presented.
+
+## 7.5 ASN.1 representations
+
+Temporal-Relationships { 2 8 1 14 0 }
+
+DEFINITIONS
+
+::= BEGIN
+
+IMPORTS
+
+Date-and-Time
+
+FROM Document-Profile-Descriptor { 2 8 1 5 6 }
+
+-- see ITU-T Rec. T.415 | ISO/IEC 8613-5 and C.4
+
+**Object-or-Class-Identifier**  
+**FROM Identifiers-and-Expressions { 2 8 1 5 7 };**  
+*-- see ITU-T Rec. T.415 | ISO/IEC 8613-5*
+
+# **EXPORTS**
+
+**Temporal-Relations, Presentation-Time, Document-Presentation-Time, Time-Scaling;**
+
+**Temporal-Relations** ::= SET{  
+     **synchronization-type** [0] IMPLICIT Synchronization-Type,  
+     **subordinate-nodes** [1] SEQUENCE OF SET{  
+         **node-identifier** [0] IMPLICIT Node-Identifier,  
+         **start-time** [1] IMPLICIT Time-Delay OPTIONAL,  
+         **duration** [2] IMPLICIT Indefinite-or-Time-Delay OPTIONAL,  
+         **cyclic** [3] IMPLICIT Cyclic OPTIONAL,  
+         **end-time** [4] IMPLICIT Time-Delay OPTIONAL,  
+         **application-comments** [5] IMPLICIT OCTET STRING OPTIONAL}}  
+*-- The value 'null' is represented by an empty set*
+
+**Synchronization-Type** ::= INTEGER{parallel-last(0),  
+     parallel-first(1), parallel-selective(2), sequential(3)}
+
+**Node-Identifier** ::= PrintableString  
+*-- only digits and spaces are used*  
+*-- the first digit is either 2 for a logical object class or 3 for a logical object*
+
+**Cyclic** ::= SET{  
+     **number-of-cycles** [0] CHOICE{Indefinite, INTEGER},  
+     **cycle-start-time** [1] IMPLICIT Time-Delay OPTIONAL,  
+     **cycle-duration** [2] IMPLICIT Indefinite-or-Time-Delay OPTIONAL}
+
+**Indefinite** ::=
+
+**Time-Delay** ::= INTEGER { indefinite(-1)}
+
+**Presentation-Time** ::= SET{  
+     **timing** CHOICE{  
+         **fixed-timing** [0] IMPLICIT INTEGER,  
+         **variable-timing** [1] IMPLICIT Time-Spec} OPTIONAL,  
+     **duration** CHOICE{  
+         **fixed-duration** [2] CHOICE{Indefinite-or-Time-Delay, Object-or-Class-Identifier},  
+         **rule-A** [3] IMPLICIT Rule-Spec,  
+         **rule-B** [4] IMPLICIT Rule-Spec} OPTIONAL,  
+     **cyclic** [5] Cyclic OPTIONAL}  
+*-- The value 'null' is represented by an empty set*
+
+**Time-Spec** ::= SET{  
+     **start-offset** [0] IMPLICIT INTEGER OPTIONAL,  
+     **end-offset** [1] IMPLICIT INTEGER OPTIONAL,  
+     **start-separation** [2] IMPLICIT INTEGER OPTIONAL,  
+     **end-separation** [3] IMPLICIT INTEGER OPTIONAL}
+
+**Rule-Spec** ::= SET{  
+     **minimum-duration** [0] IMPLICIT INTEGER OPTIONAL,  
+     **maximum-duration** [1] IMPLICIT INTEGER OPTIONAL}
+
+**Indefinite-or-Time-Delay** ::= CHOICE{  
+     **indefinite** [0] IMPLICIT NULL,  
+     **fixed** [1] Time-Delay}
+
+**Document-Presentation-Time** ::= Date-and-Time
+
+**Time-Scaling** ::= IMPLICIT SEQUENCE {INTEGER,INTEGER}  
+**END**
+
+# 8 Non-linear structures
+
+## 8.1 Structural model of a hypermedia document
+
+The structural model introduces the structural elements of the hypermedia document architecture.
+
+A hypermedia document is distinguished from a normal document by the presence of *links* which establish relationships between *nodes*. Different hypermedia documents may use the same set of nodes and link them in different ways.
+
+A node may be related to any number of other nodes within the same document or within other documents. This means that from a structural point of view, the same node may be referred to by more than one link, although this node is contained (i.e. encoded) only once in the hypermedia document. Thus the links between the nodes are in the form of general directed graphs.
+
+The nodes in a hypermedia document can consist of processable documents or document fragments, formatted documents or document fragments, formatted-processable documents or document fragments or a mixture thereof.
+
+### 8.1.1 Nodes
+
+A node is either a whole document or hypermedia document or a document fragment.
+
+A document is structured as defined in the ITU-T Rec. T.410-Series | ISO/IEC 8613 and in accordance with the extended architectural model defined in clause 6. A document may be in processable, formatted or formatted processable form.
+
+A document fragment is specified by a location expression as defined in ITU-T Rec. T.422 | ISO/IEC 8613-12.
+
+### 8.1.2 Links
+
+Links represent relationships between any number of nodes.
+
+Links are a means to express arbitrary relationships which are an integral part of an ODA document, such as cross-references or pointers to annotations.
+
+Furthermore, links may be used to establish relations between nodes without altering the underlying documents or document fragments, i.e. the same set of nodes may be composed into a number of different hypermedia documents.
+
+Links may be part of the document description (often referred to as *integral links*) or – separated from a particular document description – part of the hypermedia document as a whole (often referred to as *non-integral links*).
+
+### 8.1.3 Link classes
+
+A set of links may have common characteristics, for example:
+
+- to be used by beginners or advanced users;
+- to be processed as a result of a user interaction rather than automatically;
+- pointing to a certain kind of logical objects such as definitions or annotations;
+- representing a cross-reference.
+
+A *link class* is a structural element that may be used for factorizing such common characteristics.
+
+ITU-T Rec. T.410-Series | ISO/IEC 8613 does not define particular link classes; however it provides the means by which link classes may be defined by applications or document application profiles.
+
+## 8.2 Descriptive representation of a hypermedia document
+
+The descriptive representation introduces the descriptive elements of the hypermedia document architecture.
+
+For the purpose of interchange, a hypermedia document is represented as a collection of constituents, each of which is a set of attributes. Within the ITU-T Rec. T.410-Series | ISO/IEC 8613 each attribute is identified by a name and has a value, which either represents a characteristic of a structural element or a relationship with other constituents.
+
+ITU-T Rec. T.412 | ISO/IEC 8613-2 defines the constituents representing a document. In addition, the following types of constituents are defined to represent a hypermedia document:
+
+- link class description;
+- link description;
+- enciphered link descriptions.
+
+Constituents are grouped into sets of constituents, which have inter-relationships as defined in the ITU-T Rec. T.410-Series | ISO/IEC 8613.
+
+The possible types of constituents in the descriptive representation of a hypermedia document are shown in Figure 2.
+
+Figure 2 illustrates that:
+
+- the hypermedia document consists of one document profile, zero, one or more sub-profiles and a number of constituents that form the hypermedia document body;
+- the hypermedia document body consists of constituents representing the links or enciphered links and documents or document fragments containing the nodes;
+- the link part consists of link descriptions or link class descriptions;
+- the protected part includes enciphered link descriptions;
+- the document part consists of the document description as described in the descriptive model of a document in ITU-T Rec. T.412 | ISO/IEC 8613-2, ITU-T Rec. T.422 | ISO/IEC 8613-12 and clause 6.
+
+NOTE – The description of document fragments is included in the document descriptions.
+
+![Figure 2: Descriptive model of a hypermedia document. The diagram shows a hierarchical structure. At the top is the 'Hypermedia document description' box, which contains a 'Document profile' box and a 'Sub-profile' box (represented by a stack of three boxes). Below this is the 'Hypermedia document body' box, which contains three main sections: 'Protected part', 'Link part', and 'Document part'. The 'Protected part' contains a stack of 'Enciphered link part description' boxes. The 'Link part' contains a stack of 'Link class description' boxes and a stack of 'Link description' boxes. The 'Document part' contains a 'Document description' box. At the bottom, a legend indicates that a single box represents a 'Constituent' and a rounded rectangle represents a 'Set of constituents'.](844077b3034f0030b404207db0ad76b4_img.jpg)
+
+TISO7440-96/d04
+
+Figure 2: Descriptive model of a hypermedia document. The diagram shows a hierarchical structure. At the top is the 'Hypermedia document description' box, which contains a 'Document profile' box and a 'Sub-profile' box (represented by a stack of three boxes). Below this is the 'Hypermedia document body' box, which contains three main sections: 'Protected part', 'Link part', and 'Document part'. The 'Protected part' contains a stack of 'Enciphered link part description' boxes. The 'Link part' contains a stack of 'Link class description' boxes and a stack of 'Link description' boxes. The 'Document part' contains a 'Document description' box. At the bottom, a legend indicates that a single box represents a 'Constituent' and a rounded rectangle represents a 'Set of constituents'.
+
+**Figure 2 – Descriptive model of a hypermedia document**
+
+## 8.3 Attribute definitions for links and link classes
+
+Links and link classes consist of a set of attributes.
+
+Table 2 summarizes the attributes which may be specified for link descriptions and link class descriptions.
+
+**Table 2 – Summary of attributes for link descriptions and link class descriptions**
+
+| Link description       | Link class description |
+|------------------------|------------------------|
+| link identifier        | link class identifier  |
+| link class             |                        |
+| link roles             | link roles             |
+| application comments   | application comments   |
+| user-readable comments | user-readable comments |
+| user-visible name      | user-visible name      |
+| temporal relations     | temporal relations     |
+| presentation time      | presentation time      |
+| sealed                 | sealed                 |
+
+The values for defaultable attributes of links can be derived from:
+
+- within the link description;
+- within the link class description;
+- within the ITU-T Rec. T.410-Series | ISO/IEC 8613.
+
+The value of the attribute of a link that is classified as defaultable is determined by the first of the following rules which is applicable:
+
+- if the attribute value is specified for the link description, then that value is used;
+- if the link description concerned refers to a link class description, and that link class description contains a value for the corresponding attribute, then the value of the attribute is derived from that corresponding attribute;
+- the default value defined in ITU-T Rec. T.410-Series | ISO/IEC 8613 is used.
+
+### 8.3.1 Link identifier
+
+#### Constituents
+
+Link descriptions.
+
+#### Classification
+
+- Mandatory.
+
+#### Permissible values
+
+A sequence of two non-negative integers. The value assigned to the first integer is 10.
+
+#### Representation
+
+A character string consisting of decimal numerals and a space character. The space character is used as a separator between successive numerals. The second integer shall be unique within the hypermedia document.
+
+#### Definition
+
+This attribute identifies a link description uniquely within a link part.
+
+### 8.3.2 Link class identifier
+
+#### Constituents
+
+Link class descriptions.
+
+#### Classification
+
+- Mandatory.
+
+#### **Permissible values**
+
+A sequence of two non-negative integers. The value assigned to the first integer is 11.
+
+#### **Representation**
+
+A character string consisting of decimal numerals and a space character. The space character is used as a separator between successive numerals. The second integer shall be unique within the hypermedia document.
+
+##### **Definition**
+
+This attribute identifies a link class description uniquely within a link part.
+
+### **8.3.3 Link class**
+
+#### **Constituents**
+
+Link descriptions.
+
+#### **Classification**
+
+- Non-mandatory.
+
+#### **Permissible values**
+
+The identifier of a link class.
+
+##### **Definition**
+
+This attribute is used to establish a relationship between a link description and its link class description.
+
+The value of this attribute is the identifier of the corresponding link class description (see 8.3.2)
+
+### **8.3.4 Link roles**
+
+#### **Constituents**
+
+Link class descriptions and link descriptions.
+
+#### **Classification**
+
+- non-mandatory for link class descriptions;
+- mandatory for link descriptions.
+
+#### **Structure**
+
+If specified for link class descriptions, a sequence of one or more entries where each entry may consist of the optional parameters "layout style", "presentation style", "application comments", "user-visible name" and "user-readable comments".
+
+If specified for link descriptions, a sequence of one or more entries where each entry consists of the parameter "link ends" and optionally the parameters "layout style", "presentation style", "application comments", "user-visible name" and "user-readable comments".
+
+The parameter "link ends" consists of a set entries, each entry containing the optional sub-parameters "reference name" and "reference qualifier" with the constraint that one of these sub-parameters shall be present, and the optional sub-parameters "layout style", "presentation style", "application comments", "user-visible name" and "user-readable comments".
+
+#### **Permissible values**
+
+For the sub-parameter "reference name": a reference name as defined in ITU-T Rec. T.422 | ISO/IEC 8613-12.
+
+For the sub-parameter "reference qualifier": a location expression as defined in ITU-T Rec. T.422 | ISO/IEC 8613-12.
+
+For the parameter or sub-parameter "layout style": a layout style identifier.
+
+For the parameter or sub-parameter "presentation style": a presentation style identifier.
+
+For the parameter or sub-parameter "application comments": an octet string.
+
+NOTE 1 – It is recommended that application comments in link descriptions are structured as described in Annex A.
+
+For the parameter or sub-parameter "user-visible name": A string of characters from a defined character set. The character set is that specified in the hypermedia document profile attribute "comments character sets". The default character set is the minimum subrepertoire of ISO 6937-2<sup>1)</sup>. In addition to the graphic character set, the control functions CARRIAGE RETURN and LINE FEED may be included in the character string. Code extension control functions for the designation and invocation of graphic character sets may also be included.
+
+For the parameter or sub-parameter "user-readable comments": A string of characters from the character set specified by the hypermedia document profile attribute "comments character sets". The default character set is the minimum subrepertoire of ISO 6937-2. In addition to the graphic character set, the control functions CARRIAGE RETURN and LINE FEED may be included in the character string. Code extension control functions for the designation and invocation of graphic character sets may also be included.
+
+##### Definition
+
+This attribute allows one to identify one or more sets of link ends for a link. For each entry, the parameter "link ends" specifies a set of nodes which serves as one set of link ends for the link.
+
+If the sub-parameter "reference name" is specified, this indicates that the link end resides in an external document (fragment). The sub-parameter "reference name", in conjunction with the parameter "reference name" of the document profile attribute "document references list", provide a mapping to this external document (fragment). If the sub-parameter "reference name" is specified, the sub-parameter "reference qualifier" shall specify only constituents which are a subset of or subordinate to the constituents identified by the parameter "reference qualifier" belonging to the referenced external document (fragment).
+
+NOTE 2 – The attribute "external references list" is defined in ITU-T Rec. T.422 | ISO/IEC 8613-12.
+
+The parameter "application comments" can be used by an application as information about the role of this link.
+
+NOTE 3 – Annex B defines possible information present in such an application comment.
+
+The sub-parameter "application comments" similarly can be used by an application as information about a single link end.
+
+The parameter "presentation style" is used to establish a relationship between this set of link ends and a presentation style. The presentation style may be used to override those attributes defined at the node(s) referred to. The parameter "presentation style" can be used to specify a default presentation style for the set of link ends. If a value is specified for the sub-parameter "presentation style" of the parameter "link ends", it overrides the value of the parameter "presentation style" for the particular link end it applies to.
+
+The parameter "layout style" is used to establish a relationship between this set of link ends and a layout style. The layout style may be used to override those attributes defined at the node(s) referred to. The parameter "layout style" can be used to specify a default layout style for the set of link ends. If a value is specified for the sub-parameter "layout style" of the parameter "link ends", it overrides the value of the parameter "layout style" for the particular link end it applies to.
+
+The parameter "user-visible name" can be used to identify the set of link ends. The parameter is intended to assist in browsing through a hypermedia document. For example, the value of this parameter may be a name which serves to indicate semantics of the link end to a human, such as "definition" or "additional background information". However, such values are not defined by ITU-T Rec. T.410-Series | ISO/IEC 8613.
+
+The sub-parameter "user-visible name" similarly can be used to identify a single link end.
+
+The parameter "user-readable comments" is intended for human perception and may be used to describe the set of link ends.
+
+The sub-parameter "user-readable comments" similarly can be used to describe a single link end.
+
+### 8.3.5 Other attributes
+
+In addition, the attributes "application comments", "user-readable comments", "user-visible name", "sealed", and either "temporal relations" or "presentation time" may be specified. The attribute "temporal relations" may be used if the nodes addressed by the links are in processable form. The attribute "presentation time" may be used if the nodes addressed by the links are in formatted form.
+
+<sup>1)</sup> ISO 6937-2:1983, *Information processing-Coded character sets for text communication – Part 2: Latin alphabetic and non-alphabetic graphic characters*.
+
+## 8.4 Attributes of the document profile
+
+This subclause defines the attributes that may occur within the document profile of a hypermedia document in addition to the document profile attributes defined in ITU-T Rec. T.414 | ISO/IEC 8613-4. Unless specified otherwise, all attributes are classified as non-mandatory.
+
+Where attribute values consist of character strings, the document profile character set is used. This set consists of SPACE, CARRIAGE RETURN, LINE FEED and a set of graphics characters. In the absence of the attribute "document profile character sets," this set of graphic characters consists of the 73 graphic characters of the minimum subrepertoire of ISO 6937-2.
+
+### 8.4.1 Entry point
+
+#### Classification
+
+- Mandatory.
+
+#### Structure
+
+Either a link identifier or the parameter "reference name" and optionally the parameter "reference qualifier".
+
+#### Permissible values
+
+For the parameter "reference name": a reference name as defined in ITU-T Rec. T.422 | ISO/IEC 8613-12.
+
+For the parameter "reference qualifier": a location expression as defined in ITU-T Rec. T.422 | ISO/IEC 8613-12 resulting in an object identifier or a link identifier.
+
+#### Definition
+
+This attribute defines the entry point of a hypermedia document, i.e. the starting point for hypermedia navigation as defined by the author of the hypermedia document. If this attribute refers to an object, that object serves as a root node for the hypermedia document. It is defined such that all other nodes are accessible from the root node by following one or more links.
+
+If the parameter "reference name" is specified, this indicates that the entry point resides in an external document (fragment). The parameter "reference name", in conjunction with the parameter "reference name" of the document profile attribute "external references list", provides a mapping to this external document (fragment). If the parameter "reference name" is specified, the sub-parameter "reference qualifier" shall specify only a constituent which is subordinate to the one identified by the parameter "reference qualifier" belonging to the referenced external document (fragment).
+
+If this attribute refers to a link, this link provides the highest level of choice for navigation.
+
+NOTE – The attribute "external references list" is defined in ITU-T Rec. T.422 | ISO/IEC 8613-12.
+
+### 8.4.2 Links
+
+This attribute is specified if, and only if, the hypermedia document contains link descriptions for non-integral links.
+
+The value of this attribute (if specified) is 'present'.
+
+### 8.4.3 Link classes
+
+This attribute is specified if, and only if, the hypermedia document contains link class descriptions for non-integral links.
+
+The value of this attribute (if specified) is 'present'.
+
+### 8.4.4 Enciphered links
+
+This attribute is specified if, and only if, the hypermedia document contains enciphered link descriptions for non-integral links.
+
+The value of this attribute (if specified) is 'present'.
+
+### 8.4.5 Pre-sealed document body parts
+
+This attribute has the same structure and semantics as the document profile attribute "pre-sealed document body parts" with the modification that the sealed constituents are only link or link class descriptions for non-integral links.
+
+## 8.5 Structural model of a document set
+
+The structural model introduces the structural elements of a document set.
+
+A document set is composed of one *document set profile*, an (optional) set of *links* which establish relationships between nodes and an (optional) set of documents and/or hypermedia documents. Different document sets may use the same set of nodes and link them in different ways.
+
+A node may be related to any number of other nodes within the same document or within other documents. This means that from a structural point of view, the same node may be referred to by more than one link, although this node is contained (i.e. encoded) only once in the document set. Thus the links between the nodes are in the form of general directed graphs.
+
+The nodes in a document set can consist of processable documents or document fragments, formatted documents or document fragments, formatted-processable documents or document fragments or a mixture thereof.
+
+An example of a document set is shown in Figure 3.
+
+### 8.5.1 Nodes
+
+A node is either a whole document or hypermedia document or a document fragment.
+
+A document is structured as defined in the ITU-T Rec. T.410-Series | ISO/IEC 8613 and in accordance with the extended architectural model defined in clause 6. A document may be in processable, formatted or formatted processable form.
+
+A document fragment is specified by a location expression as defined in ITU-T Rec. T.422 | ISO/IEC 8613-12.
+
+### 8.5.2 Links
+
+Links represent relationships between any number of nodes.
+
+Links in a document set are separate from a particular document description part, i.e. they are *non-integral links*.
+
+### 8.5.3 Link classes
+
+A set of links may have common characteristics; for example:
+
+- to be used by beginners or advanced users;
+- to be processed as a result of a user interaction rather than automatically;
+- pointing to a certain kind of logical objects such as definitions or annotations;
+- representing a cross-reference.
+
+A *link class* is a structural element that may be used for factorizing such common characteristics.
+
+ITU-T Rec. T.410-Series | ISO/IEC 8613 does not define particular link classes; however it provides the means by which link classes may be defined by applications or document application profiles.
+
+### 8.5.4 Document set profile
+
+The document set profile consists of a set of attributes which specify characteristics of the document set as a whole as well as the entry point to the document set (root node). It is not the intention of the document set profile to duplicate the information in the document profiles of the documents or hypermedia documents which are part of the document set. The attribute values in the document set profile may differ from all values in the associated document profiles.
+
+A document set profile may be interchanged or stored independent of the nodes and links of the document set.
+
+The document set profile contains information for use by humans beings and for machine processing.
+
+## 8.6 Document set profile attributes
+
+This subclause defines the attributes that may occur within the document set profile. Unless specified otherwise, all attributes are classified as non-mandatory.
+
+Where attribute values consist of character strings, the document set profile character set is used. This set consists of SPACE, CARRIAGE RETURN, LINE FEED and a set of graphics characters. In the absence of the attribute "document set profile character sets," this set of graphic characters consists of the 73 graphic characters of the minimum subrepertoire of ISO 6937-2.
+
+![Figure 3: Illustrative model of the structure of document sets. The diagram shows the hierarchical structure of document sets, from document set profiles to individual link parts and their constituent elements.](2bacc162a73d75c43a7f90715832bd13_img.jpg)
+
+The diagram illustrates the structure of document sets, showing the relationship between document set profiles, link parts, and their constituent elements.
+
+**Document Set Profiles:** Two profiles are shown: "Document set profile 1" and "Document set profile 2", separated by "or". Each profile contains an "Entry point".
+
+**Hypermedia Documents:** Four documents are shown: "Hypermedia document 1", "Hypermedia document 2", "Document 3", and "Document 4".
+
+- Hypermedia document 1:** Contains a tree structure with a "Document profile" and a "Link part" (indicated by a dashed line).
+- Hypermedia document 2:** Contains a tree structure with a "Document profile" and a "Link part" (indicated by a dashed line).
+- Document 3:** Contains a "Sub-tree" and a "Set of constituents" (indicated by a dashed line).
+- Document 4:** Contains a tree structure with a "Region" (indicated by a dashed line).
+
+**Link Part Structure:** A detailed view of a "Link part" shows its internal structure:
+
+- Link descriptor:** Contains "Link descriptor 1", "Link descriptor 2", and "Link descriptor n".
+- Link class descriptor:** Contains "Link class descriptor 1" and "Link class descriptor 2".
+- Link role:** Contains "Link role 1", "Link role 2", and "Link role n".
+- Link end:** Contains "Link end 1", "Link end 2", and "Link end n".
+- Reference:** Contains "Reference", "Presentation style", and "Layout style".
+- Layout style:** Contains "Layout style".
+- Presentation style:** Contains "Presentation style" and "Layout style".
+
+Dashed lines indicate the flow of information and relationships between the various components.
+
+TISO7450-96/d05
+
+Figure 3: Illustrative model of the structure of document sets. The diagram shows the hierarchical structure of document sets, from document set profiles to individual link parts and their constituent elements.
+
+Figure 3 – Illustrative model of the structure of document sets
+
+### 8.6.1 Entry point
+
+#### Classification
+
+- Mandatory.
+
+#### Structure
+
+Either a link identifier or the parameter "reference name" and optionally the parameter "reference qualifier".
+
+#### Permissible values
+
+For the parameter "reference name": a reference name as defined in ITU-T Rec. T.422 | ISO/IEC 8613-12.
+
+For the parameter "reference qualifier": a location expression as defined in ITU-T Rec. T.422 | ISO/IEC 8613-12 resulting in an object identifier or a link identifier.
+
+#### Definition
+
+This attribute defines the entry point of a document set, i.e. the starting point for navigation as defined by the author of the document set. If this attribute refers to an object, that object serves as a root node for the hypermedia document. It is defined such that all other nodes are accessible from the root node by following one or more links.
+
+If the parameter "reference name" is specified, this indicates that the entry point resides in an external document (fragment). The parameter "reference name", in conjunction with the parameter "reference name" of the document profile attribute "external references list", provides a mapping to this external document (fragment). If the parameter "reference name" is specified, the sub-parameter "reference qualifier" shall specify only a constituent which is subordinate to the one identified by the parameter "reference qualifier" belonging to the referenced external document (fragment).
+
+If this attribute refers to a link, this link provides the highest level of choice for navigation.
+
+NOTE – The attribute "external references list" is defined in ITU-T Rec. T.422 | ISO/IEC 8613-12.
+
+### 8.6.2 Links
+
+This attribute is specified if, and only if, the document set contains link descriptions for non-integral links.
+
+The value of this attribute (if specified) is 'present'.
+
+### 8.6.3 Link classes
+
+This attribute is specified if, and only if, the document set contains link class descriptions for non-integral links.
+
+The value of this attribute (if specified) is 'present'.
+
+### 8.6.4 Enciphered links
+
+This attribute is specified if, and only if, the document set contains enciphered link descriptions for non-integral links.
+
+The value of this attribute (if specified) is 'present'.
+
+### 8.6.5 Pre-sealed document body parts
+
+This attribute has the same structure and semantics as the document profile attribute "pre-sealed document body parts" with the modification that the sealed constituents are only link or link class descriptions for non-integral links.
+
+### 8.6.6 Document set characteristics
+
+#### 8.6.6.1 Interchange format class
+
+This attribute specifies the interchange format class used to represent the document set. This attribute shall always be specified. The value of this attribute is 'A'.
+
+NOTE – The definition of interchange format class A as defined in ITU-T Rec. T.415 | ISO/IEC 8613-5 is amended to allow the additional data elements defined by this Recommendation | International Standard.
+
+#### 8.6.6.2 ODA version
+
+This attribute identifies the Document Architecture Standard or Recommendation version, and its publication date, to which the document set conforms. This attribute shall always be specified.
+
+The value of this attribute is structured as defined in 7.3.6 of ITU-T Rec. T.414 | ISO/IEC 8613-4.
+
+#### 8.6.6.3 Non-basic document set characteristics
+
+##### 8.6.6.3.1 Document set profile character sets
+
+This attribute specifies the graphic character set(s), other than the character set specified in clause 8, used in those document set profile attributes that consist of character strings.
+
+The value of this attribute consists of the escape sequence(s) used to announce and to designate the set(s) in accordance with ISO 2022 and the register of ISO 2375.
+
+In the absence of this attribute the same assumptions as specified in 7.3.8.1 of ITU-T Rec. T.414 | ISO/IEC 8613-4 apply.
+
+##### 8.6.6.3.2 Comments character sets
+
+This attribute specifies the graphic character set(s), other than the default character set specified in ITU-T Rec. T.412 | ISO/IEC 8613-2, used by the link attributes "user-readable comments" and "user-visible name" in the link part for non-integral links of the document set.
+
+The value of this attribute consists of the escape sequence(s) used to announce and to designate the set(s) in accordance with ISO 2022 and the register of ISO 2375.
+
+#### 8.6.6.4 Document set description
+
+##### 8.6.6.4.1 Title
+
+This attribute gives the name of the document set represented by the document set profile, the optional link part for the non-integral links and the optional set of documents or document fragments as specified by the author.
+
+The value of this attribute consists of a string of characters from the document set profile character set.
+
+##### 8.6.6.4.2 Subject
+
+This attribute contains information to indicate the subject of the document set.
+
+The value of this attribute consists of a string of characters from the document set profile character set.
+
+##### 8.6.6.4.3 Document reference
+
+This attribute identifies the document set. The attribute's value is used to refer to the document set (see.8.6.8).
+
+The value of this attribute is either an ASN.1 object identifier or a string of characters from the document set profile character set.
+
+##### 8.6.6.4.4 Document type
+
+This attribute specifies the type of document set, e.g. slide show, audio/visual repair manual. This attribute specifies only an informal name; it does not specify a relation to a particular document class description.
+
+The value of this attribute consists of a string of characters from the document set profile character set.
+
+##### 8.6.6.4.5 Abstract
+
+This attribute contains information to summarize the document set.
+
+The value of this attribute consists of a string of characters from the document set profile character set.
+
+##### 8.6.6.4.6 Keywords
+
+This attribute specifies one or more character strings that permit logical associations to be made about the content of the document set.
+
+The value of this attribute consists of string(s) of characters from the document set profile character set.
+
+### 8.6.7 Other attributes
+
+In addition, the following attributes may be specified for the document set profile:
+
+- "document date and time";
+- "creation date and time";
+- "local filing date and time";
+- "expire date and time";
+- "start date and time";
+
+- "purge date and time";
+- "release date and time";
+- "revision history";
+- "organizations";
+- "preparers";
+- "owners";
+- "authors";
+- "copyright";
+- "status";
+- "user-specific codes";
+- "distribution list";
+- "additional information ";
+- "superseded documents";
+- "local file references";
+- "authorization";
+- "security classification";
+- "access rights".
+
+The semantics of these attributes are as defined in ITU-T Rec. T.414 | ISO/IEC 8613-4 with the modification that whenever the descriptions of these attributes use the term *document*, the term *document* shall be replaced by *document set*.
+
+### 8.6.8 References to documents
+
+This attribute specifies reference(s) to any document or document fragment which is referenced in the link part for the non-integral links. It consists of one or more entries.
+
+The value of each entry is either an ASN.1 object identifier or a string of characters from the document set profile character set.
+
+This value is equal to the value of the document profile attribute "document reference" of the document or document fragment referred to.
+
+### 8.6.9 Security features
+
+To prohibit unauthorized access to a document set profile, the document set profile may be enciphered, i.e. a document may contain a constituent of type *enciphered document set profile*.
+
+To support authenticity, integrity and non-repudiation of a document set profile, a document may contain a constituent of type *sealed document set profile*.
+
+## 8.7 Enciphered link part description
+
+To prohibit unauthorized access to links and link classes, these constituents may be enciphered, i.e. a document may contain constituents of type *enciphered link part*.
+
+Enciphered link part descriptions are included in the protected part of a document set. An enciphered link part description consists of two attributes:
+
+- protected part identifier;
+- enciphered information.
+
+The attributes "protected part identifier" and "enciphered information" are as defined in ITU-T Rec. T.412 | ISO/IEC 8613-2 with the following additional/modified semantics:
+
+- The value of the attribute "enciphered information" contains the result of a cryptographic algorithm applied to a sequence of constituents of the link part.
+
+## 8.8 Reference model for the hypermedia document and document set editing process
+
+The reference model for the editing process as defined in ITU-T Rec. T.412 | ISO/IEC 8613-2 applies also to the editing process for a hypermedia document or document set.
+
+In addition, the editing process for a hypermedia document or document set is concerned with the creation/modification of links, link classes and /or the document set profile.
+
+## 8.9 Reference model for the hypermedia document and document set layout process
+
+The reference model for the layout process as described in clause 10 of ITU-T Rec. T.412 | ISO/IEC 8613-2 is extended as follows: if a processable document with a structure as described in ITU-T Rec. T.412 | ISO/IEC 8613-2 contains a link part for integral links, the layout process adds additional links between layout objects created by the layout process to the link part. These additional links reflect the links specified between constituents of the logical structure. Otherwise, the presence of a link part with integral links has no effect to the specific layout structure created by the layout process. In particular, links are not traversed automatically during the layout process.
+
+The remaining specifications in this subclause address only the case that a hypermedia document or document set contains non-integral links and/or that it contains integral links which, in a particular application, are to be taken into account explicitly, thus ignoring the existing sequential order of the constituents of the document.
+
+Since a hypermedia document is distinguished from a normal document by the presence of links which provide different possibilities for reading the content of a hypermedia document, there exists no single visual representation of a hypermedia document. This applies also for a document set with links. Therefore, the layout process as described in this subclause does not result in a (single) specific layout structure as defined in ITU-T Rec. T.412 | ISO/IEC 8613-2.
+
+NOTE 1 – Even if all nodes in a hypermedia document or document set are in formatted form, the union of all specific structures in the nodes does not represent the specific layout structure of a hypermedia document or document set; the concept of the specific structure of a hypermedia document or document set as such does not exist.
+
+The reference model for the layout process specifies only a set of rules for the individual layout processes which are carried out whenever a new node (which is in processable form) is reached by following a node during document browsing. The result of each individual layout process is an *intermediate* specific layout structure according to ITU-T Rec. T.412 | ISO/IEC 8613-2 which is not intended for inclusion into interchanged hypermedia document or document set data streams.
+
+It is assumed that each node (which is in processable form) can be laid out in accordance with the rules defined below and the rules defined in ITU-T Rec. T.412 | ISO/IEC 8613-2. That is, it is assumed that each attribute pertaining to the layout process can be interpreted in accordance with the definition of the attribute. It is outside the scope of this Recommendation | International Standard to indicate how a node containing conflicting or inconsistent information is to be laid out.
+
+During the hypermedia document or document set layout process the layout of each node follows the layout specifications as defined for that node, unless the layout specifications are overridden by the corresponding parameters of the link description (presentation style, layout style, generic structure). In the latter case, the layout process has to be carried out in line with the specifications in the ITU-T Rec. T.410-Series | ISO/IEC 8613 using the values provided by the link description.
+
+NOTE 2 – If there exist specifications with respect to temporal relationships for the presentation of content associated with different nodes, the individual layout processes may need to interact to satisfy these specifications.
+
+## 8.10 Reference Model for the hypermedia document and document set presentation process
+
+The presentation process for a hypermedia document or document set is a sequence of presentation processes as defined in the ITU-T Rec. T.410-Series | ISO/IEC 8613.
+
+An individual presentation process is started whenever:
+
+- a new node (which is in formatted or formatted-processable form) is reached by following a link during document browsing; or
+- an individual document layout process for a node as described in 8.9 is finished.
+
+## 8.11 ASN.1 representations
+
+### 8.11.1 Document set descriptor
+
+**Document-Set-Descriptor { 2 8 1 14 1 }**
+
+**DEFINITIONS ::=** BEGIN
+
+**EXPORTS** Document-Set;
+
+**IMPORTS** Interchange-Data-Element  
+FROM Interchange-Data-Elements { 2 8 1 5 5 }  
+-- see ITU-T Rec. T.415 | ISO/IEC 8613-5
+
+**Document-Set-Profile-Descriptor**  
+**FROM Document-Set-Profile-Descriptor**  
+ -- *see 8.11.2*
+
+**Link-Class-Descriptor, Link-Descriptor,**  
+**Enciphered-Link-Descriptor**  
+**FROM Link-Descriptors;**  
+ -- *see 8.11.3*
+
+```
+Document-Set ::=
+  profile          SEQUENCE{
+    link-classes    Document-Set-Profile-Descriptor,
+    links           [0] SET OF Link-Class-Descriptor OPTIONAL,
+    nodes           [1] SET OF Link-Descriptor OPTIONAL,
+    enciphered-links [2] SET OF Interchange-Data-Element OPTIONAL,
+                  [3] SET OF Enciphered-Link-Descriptor OPTIONAL}
+  END
+```
+
+### 8.11.2 Document set profile descriptor
+
+**Document-Set-Profile-Descriptor { 2 8 1 14 2 }**
+
+**DEFINITIONS ::= BEGIN**
+
+**EXPORTS Document-Set-Profile-Descriptor;**
+
+**IMPORTS**  
+**Location-Expression**  
+**FROM Location-Expressions { 2 8 1 12 0 }**  
+ -- *see ITU-T Rec. T.422 | ISO/IEC 8613-12*
+
+**Reference-Name, External-References-List**  
+**FROM External-References { 2 8 1 12 1 }**  
+ -- *see ITU-T Rec. T.422 | ISO/IEC 8613-12*
+
+**ODA-Version, Document-Description, Dates-and-Times, Originators,**  
+**Other-User-Information, External-References,**  
+**Local-File-References, Security-Information, Sealed-Doc-Bodyparts**  
+**FROM Document-Profile-Descriptor { 2 8 1 5 6 }**  
+ -- *see ITU-T Rec. T.415 | ISO/IEC 8613-5 and C.4*
+
+**Link-or-Link-Class-Identifier**  
+**FROM Link-Descriptors;**  
+ -- *see 8.11.3*
+
+```
+Document-Set-Profile-Descriptor ::=SET{
+  entry-point          Entry-Point,
+  external-references-list [0] IMPLICIT External-References-List OPTIONAL,
+  interchange-format-class [1] IMPLICIT INTEGER {if-a (0)},
+  oda-version          [2] IMPLICIT ODA-Version,
+  profile-character-sets [3] IMPLICIT OCTET STRING OPTIONAL,
+  document-description [4] IMPLICIT Document-Description OPTIONAL,
+  dates-and-times       [5] IMPLICIT Dates-and-Times OPTIONAL,
+  originators           [6] IMPLICIT Originators OPTIONAL,
+  other-user-information [7] IMPLICIT Other-User-Information OPTIONAL,
+  external-references    [8] IMPLICIT External-References OPTIONAL,
+  local-file-references  [9] IMPLICIT Local-File-References OPTIONAL,
+  security-information   [10] IMPLICIT Security-Information OPTIONAL,
+  links                 [11] IMPLICIT NumericString OPTIONAL,
+  link-classes           [12] IMPLICIT NumericString OPTIONAL,
+  enciphered-links       [13] IMPLICIT NumericString OPTIONAL,
+  sealed-links           [14] IMPLICIT Sealed-Doc-Bodyparts OPTIONAL}
+  -- The numeric string has the value 'present', represented by "1"
+```
+
+```
+Entry-Point ::=CHOICE{
+  link-id          Link-or-Link-Class-Identifier,
+  reference         [1] SET{
+    reference-name [0] Reference-Name OPTIONAL,
+    reference-qualifier [1] Location-Expression OPTIONAL}
+  END
+```
+
+### 8.11.3 Link descriptors
+
+**Link-Descriptors { 2 8 1 14 3 }**
+
+```
+
+DEFINITIONS ::= BEGIN
+
+EXPORTS
+    Link-Class-Descriptor, Link-Descriptor,
+    Link-or-Link-Class-Identifier, Enciphered-Link-Descriptor;
+
+IMPORTS
+    Reference-Name
+    FROM External-References { 2 8 1 12 1 }
+    -- see ITU-T Rec. T.422 | ISO/IEC 8613-12
+
+    Location-Expression
+    FROM Location-Expressions { 2 8 1 12 0 }
+    -- see ITU-T Rec. T.422 | ISO/IEC 8613-12
+
+    Style-Identifier, Protected-Part-Identifier
+    FROM Identifiers-and-Expressions { 2 8 1 5 7 }
+    -- see ITU-T Rec. T.415 | ISO/IEC 8613-5
+
+    Comment-String, Sealed
+    FROM Layout-Descriptors { 2 8 1 5 8 }
+    -- see ITU-T Rec. T.415 | ISO/IEC 8613-5
+
+    Temporal-Relations, Presentation-Time
+    FROM Temporal-Relationships;
+    -- see 7.5
+
+Link-or-Link-Class-Identifier ::= [APPLICATION 9] IMPLICIT PrintableString
+--      only digits and space are used in the present version of this Recommendation | International Standard;
+--      other characters are reserved for extensions
+
+Link-Class-Descriptor ::= SET{
+    link-class-identifier      Link-or-Link-Class-Identifier,
+    link-roles                 [1] SEQUENCE OF Link-Role OPTIONAL,
+    user-readable-comments     [2] IMPLICIT Comment-String OPTIONAL,
+    user-visible-name          [3] IMPLICIT Comment-String OPTIONAL,
+    application-comments       [25] IMPLICIT OCTET STRING OPTIONAL,
+    sealed                     [35] IMPLICIT Sealed OPTIONAL,
+    temporal-relations         [38] IMPLICIT Temporal-Relations OPTIONAL,
+    presentation-time          [39] IMPLICIT Presentation-Time OPTIONAL}
+
+Link-Descriptor ::= SET{
+    link-identifier            Link-or-Link-Class-Identifier,
+    link-class                 [0] IMPLICIT Link-or-Link-Class-Identifier OPTIONAL,
+    link-roles                 [1] SEQUENCE OF Link-Role OPTIONAL,
+    user-readable-comments     [2] IMPLICIT Comment-String OPTIONAL,
+    user-visible-name          [3] IMPLICIT Comment-String OPTIONAL,
+    application-comments       [25] IMPLICIT OCTET STRING OPTIONAL,
+    sealed                     [35] IMPLICIT Sealed OPTIONAL,
+    temporal-relations         [38] IMPLICIT Temporal-Relations OPTIONAL,
+    presentation-time          [39] IMPLICIT Presentation-Time OPTIONAL}
+
+Link-Role ::= SET{
+    link-ends                  SET OF Link-End,
+    user-readable-comments     [2] IMPLICIT Comment-String OPTIONAL,
+    user-visible-name          [3] IMPLICIT Comment-String OPTIONAL,
+    application-comments       [25] IMPLICIT OCTET STRING OPTIONAL}
+
+Link-End ::= SET{
+    reference                  SET{
+        reference-name          [0] Reference-Name OPTIONAL
+        reference-qualifier      [1] Location-Expression OPTIONAL},
+    user-readable-comments     [2] IMPLICIT Comment-String OPTIONAL,
+    user-visible-name          [3] IMPLICIT Comment-String OPTIONAL,
+    presentation-style         [17] IMPLICIT Style-Identifier OPTIONAL,
+    layout-style               [19] IMPLICIT Style-Identifier OPTIONAL,
+    application-comments       [25] IMPLICIT OCTET STRING OPTIONAL}
+
+Enciphered-Link-Descriptor ::= SEQUENCE{
+    protected-part-identifier  Protected-Part-Identifier,
+    enciphered-information     OCTET STRING}
+
+END
+
+```
+
+# Annex A
+
+## Structuring conventions for "application comments"
+
+(This annex forms an integral part of this Recommendation | International Standard)
+
+NOTE 1 – This annex contains specifications which are not only useful for this Recommendation | International Standard. Therefore, this annex may be moved to another part (e.g. Part 1 or 2) of ITU-T Rec. T.410-Series | ISO/IEC 8613 with the next republication.
+
+This annex describes conventions for the use of the attribute (or parameter or sub-parameter) "application comments" to represent application specific information that can automatically be extracted by applications.
+
+In order to represent application specific information within the attribute "application comments", an appropriate substructure of this attribute shall be used which is specified subsequently.
+
+According to this Recommendation | International Standard and ITU-T Rec. T.415 | ISO/IEC 8613-5, this attribute is encoded as an ASN.1 OCTET STRING:
+
+**application-comments**                    [...] IMPLICIT OCTET STRING OPTIONAL ....
+
+Within this OCTET STRING, ASN.1 Basic Encoding Rules are applied, again, resulting in a substructure of two components:
+
+**Appl-Comm-Encoding** ::=        SEQUENCE {  
+     **constraint-name**            [0] IMPLICIT PrintableString OPTIONAL,  
+     **external-data**             [1] IMPLICIT OCTET STRING OPTIONAL}
+
+The first component is a PrintableString.
+
+NOTE 2 – This component is intended to be used by document application profiles to identify the DAP constituent constraints defined therein.
+
+The second component is encoded as an ASN.1 OCTET STRING which is, in turn, substructured as a sequence of ASN.1 EXTERNAL types represented in ASN.1 Basic Encoding Rules.
+
+**Appl-Comm-External-Data-Encoding** ::=        SEQUENCE OF EXTERNAL
+
+Each EXTERNAL value shall consist of at least two components:
+
+- an ASN.1 OBJECT IDENTIFIER to uniquely identify the corresponding type; and
+- the value itself, being encoded as an OCTET STRING, again.
+
+NOTE 3 – As defined in CCITT Rec. X.208 and ISO/IEC 8824, one possible form of EXTERNAL is:
+
+**EXTERNAL**                :=        [UNIVERSAL 8] IMPLICIT SEQUENCE {  
+     **direct-reference**        OBJECT IDENTIFIER,  
+     **encoding**                [1] IMPLICIT OCTET STRING}
+
+NOTE 4 – This substructure has been chosen in order to conform to existing document application profiles and to provide maximum flexibility for making use of the attribute "application comments" in arbitrary applications.
+
+# Annex B
+
+## Usage of the attribute/parameter "application comments" in links
+
+(This annex forms an integral part of this Recommendation | International Standard)
+
+This annex specifies ASN.1 object identifiers for use within application comments in link descriptions and link class descriptions. It also provides examples of their use.
+
+## General
+
+Application comments structured in accordance with Annex A use sequences of ASN.1 EXTERNAL data to represent application specific information.
+
+The semantics of each piece of EXTERNAL data are identified by its ASN.1 object identifier. This object identifier is called an *application tag*.
+
+This annex defines a number of application tags that are likely to be useful for many applications of links and their semantics.
+
+NOTE – This annex requires a modification of Annex D of ITU-T Rec. T.411 | ISO/IEC 8613-1 as described in C.1.1.
+
+## B.1 Source role
+
+Applicability: within the parameter "application comments" of an attribute "linkroles".
+
+Structure of octet string: empty.
+
+ASN.1 object identifier: { 2 8 5 14 1 }.
+
+#### Definition
+
+This application tag is used to identify a link role as a possible source for traversal. It can be used to specify the traversal direction of the link:
+
+If "Source Role" applies to only a subset of the link roles of the link, it specifies that the link may only be traversed from the nodes specified by these link roles to the nodes specified by other link roles, in particular those tagged with "Destination Role".
+
+## B.2 Destination Role
+
+Applicability: within the parameter "application comments" of the attribute "linkroles".
+
+Structure of octet string: empty.
+
+ASN.1 object identifier: { 2 8 5 14 2 }.
+
+#### Definition
+
+This application tag is used to identify a link role as a possible destination for traversal. It can be used to specify the traversal direction of the link: if "Destination Role" applies to only a subset of the link roles of the link, it specifies that the link may be traversed only towards the nodes specified by these link roles from the nodes specified by other link roles, in particular those tagged with "Source Role".
+
+NOTE – A combination of "Source Role" and "Destination Role" application tags can be used to describe bidirectional links.
+
+## B.3 Single-ended Role
+
+Applicability: within the parameter "application comments" of the attribute "link roles".
+
+Structure of octet string: empty.
+
+ASN.1 object identifier: { 2 8 5 14 3 }.
+
+#### Definition
+
+This application tag specifies that the number of nodes addressed by this link role is restricted to one.
+
+## B.4 Multi-ended Role
+
+Applicability: within the parameter "application comments" of the attribute "linkroles".
+
+Structure of octet string: empty.
+
+ASN.1 object identifier: { 2 8 5 14 4 }.
+
+#### Definition
+
+This application tag specifies that there is no restriction on the number of nodes addressed by this role.
+
+## B.5 Automatic Invocation
+
+Applicability: within the attribute "application comments" of a link or link class description.
+
+Structure of octet string: empty.
+
+ASN.1 object identifier: { 2 8 5 14 5 }.
+
+#### Definition
+
+This application tag specifies that the link shall be invoked automatically when a hypermedia document is processed (e.g. presented). The processing application shall traverse the link immediately upon encountering it during processing; the destination location of the link becomes the next object in the processing sequence.
+
+NOTE – The processing model for automatic link traversal is not defined by this annex.
+
+## B.6 User Invocation
+
+Applicability: within the attribute "application comments" of a link or link class description.
+
+Structure of octet string: empty.
+
+ASN.1 object identifier: { 2 8 5 14 6 }.
+
+#### Definition
+
+This application tag specifies that the link shall be invoked selectively, i.e. by external events initiated by a user or application. This allows for navigating through the hypermedia document using different paths. The link shall be traversed only at the request of a user. How the user shall make the request is application-specific and beyond the scope of this annex.
+
+## B.7 Link-Path-Selector
+
+Applicability: within the attribute "application comments" of a link or link class description or within the parameter "application comments" of the attribute "link roles".
+
+Structure of octet string: ASN.1 binary encoding of a sequence of externals.
+
+ASN.1 object identifier: { 2 8 5 14 7 }.
+
+#### Definition
+
+This application tag is used to contain application specific information for the selection of a link or of a link role. When used within the parameter "application comments", the application tag "link-path-selector" defines the selection criteria by which the associated set of link ends may be selected for processing. The selection criteria are application-specific, and are not standardized by this annex. Similarly, when used within the attribute "application comments", the application tag defines selection criteria by which the link as a whole may be selected for processing. An example of such application-specific information might be whether the link is intended for use by an expert or a novice user.
+
+# Annex C
+
+## Modifications to other common texts of ITU-T Rec. T.410-Series | ISO/IEC 8613
+
+(This annex forms an integral part of this Recommendation | International Standard)
+
+The specifications contained in this annex are intended to be included into the other common texts of ITU-T Rec. T.410-Series | ISO/IEC 8613 with the next republication.
+
+## C.1 Modifications to ITU-T Rec. T.411 | ISO/IEC 8613-1
+
+### C.1.1 Amendment for the assignment of ASN.1 object identifiers
+
+Annex D needs to be amended to specify that the third component of ASN.1 object identifiers may be 5. In this case, the fourth component is equal to the part number of a Recommendation | International Standard of ITU-T Rec. T.410-Series | ISO/IEC 8613. The permitted values of the fifth component and the semantics of the respective ASN.1 object identifier are defined in that Recommendation | International Standard identified by the fourth component.
+
+## C.2 Modifications to ITU-T Rec. T.412 | ISO/IEC 8613-2
+
+### C.2.1 Amendment of the structural model
+
+In clause 6 the structural model needs to be extended to include a link part with links and link classes with a reference that these concepts are defined in ITU-T Rec. T.424 | ISO/IEC 8613-14.
+
+### C.2.2 Amendment of the processing model
+
+In clauses 6, 10 and 11 the processing model needs to be amended to include temporal relationships and links with a reference that the extended processing model in respect to temporal relationships and links is described in ITU-T Rec. T.424 | ISO/IEC 8613-14.
+
+### C.2.3 Amendment of attribute definitions
+
+In clause 9 the attributes temporal relations and presentation time have to be added with a reference that the structure and semantics of these attributes are defined in ITU-T Rec. T.424 | ISO/IEC 8613-14.
+
+## C.3 Modifications to ITU-T Rec. T.414 | ISO/IEC 8613-4
+
+### C.3.1 Document profile attributes for temporal relations
+
+The following attributes are added to the document profile to support temporal relations in ODA documents.
+
+#### Document presentation time
+
+The value of this attribute is a date character string and a time character string in accordance with ISO 8601.
+
+This attribute specifies the date and time at which the presentation of the document shall start. If the attribute is not specified, the presentation of the document will not start automatically but requires human interaction. If the attribute is specified, the presentation of the document is intended to start automatically at the indicated date and time.
+
+#### Time scaling
+
+The value of the attribute is a sequence of two positive integers  $m$  and  $n$ .
+
+This attribute specifies a scaling factor for all attribute, parameter and sub-parameter values which specify scaled time units. Each scaled time unit equals  $m/n$  seconds. If this attribute is not specified, the sequence of the two integers 1 and 1 is assumed.
+
+#### Temporal relations
+
+This attribute is specified if, and only if, the document contains temporal relationships. The value of this attribute (if specified) is 'present'.
+
+### C.3.2 Document profile attributes for non-linear structures
+
+The following attributes are added to the document profile to support non-linear structures in ODA documents.
+
+#### Links
+
+This attribute is specified if, and only if, the document contains link descriptions for integral links.
+
+The value of this attribute (if specified) is 'present'.
+
+#### Link classes
+
+This attribute is specified if, and only if, the document contains link class descriptions for integral links.
+
+The value of this attribute (if specified) is 'present'.
+
+#### Enciphered links
+
+This attribute is specified if, and only if, the document contains enciphered link or link class descriptions.
+
+The value of this attribute (if specified) is 'present'.
+
+## C.4 Modifications to ITU-T Rec. T.415 | ISO/IEC 8613-5
+
+### C.4.1 Amendment of interchange data elements
+
+In addition to the interchange data elements defined in ITU-T Rec. T.415 | ISO/IEC 8613-5, the following data elements are permitted in interchange format class A:
+
+- link descriptor;
+- link class descriptor;
+- enciphered link descriptor.
+
+These interchange data elements appear in the following order (see 7.2 of ITU-T Rec. T.415 | ISO/IEC 8613-5):
+
+- o) link class descriptors;
+- p) link descriptors;
+- q) enciphered link descriptors.
+
+#### Interchange-Data-Elements { 2 8 1 5 5 }
+
+```
+IMPORTS          -- Existing definition; extended by the following:
+                  Link-Class-Descriptor, Link-Descriptor, Enciphered-Link-Descriptor
+FROM Link-Descriptors { 2 8 1 14 3 }
+-- See ITU-T Rec. T.424 | ISO/IEC 8613-14
+```
+
+```
+Interchange-Data-Element ::= CHOICE{ -- Existing definition; extended by the following:
+link-class                [13] IMPLICIT Link-Class-Descriptor,
+link                      [14] IMPLICIT Link-Descriptor,
+enciphered-link-descriptor [15] IMPLICIT Enciphered-Link-Descriptor}
+```
+
+### C.4.2 Amendment of the document profile descriptor
+
+```
+EXPORTS          -- Existing definition; extended by the following:
+                  Document-Description, Dates-and-Times, Originators,
+                  Other-User-Information, External-References,
+                  Local-File-References, Security-Information, ODA-Version,
+                  Sealed-Doc-Bodyparts, Date-and-Time
+```
+
+```
+IMPORTS          -- Existing definition; extended by the following:
+                  Document-Presentation-Time, Time-Scaling
+FROM Temporal-Relationships { 2 8 1 14 0 }
+-- See ITU-T Rec. T.424 | ISO/IEC 8613-14
+```
+
+```
+Document-Profile-Descriptor ::= SET{ -- Existing definition; replaced and extended by the following:
+links                        [17] IMPLICIT NumericString OPTIONAL,
+link-classes                 [18] IMPLICIT NumericString OPTIONAL,
+enciphered-links             [19] IMPLICIT NumericString OPTIONAL,
+temporal-relations           [20] IMPLICIT NumericString OPTIONAL}
+```
+
+```
+Document-Characteristics ::= SET{ -- Existing definition; modified by the following:
+oda-version                  [8] IMPLICIT ODA-Version,
+```
+
+```
+ODA-Version ::= SEQUENCE{
+standard-or-recommendation Character-Data,
+publication-date           Date-and-Time}
+```
+
+**Document-Security-Attributes** ::= SET{ -- Existing definition; extended by the following:  
+**sealed-links** [8] IMPLICIT Sealed-Doc-Bodyparts OPTIONAL
+
+**Additional-Doc-Characteristics** ::= SET{ -- Existing definition; extended by the following:  
+**time-scaling** [6] IMPLICIT Time-Scaling OPTIONAL,  
+**document-presentation-time** [7] IMPLICIT Document-Presentation-Time OPTIONAL}
+
+### C.4.3 Amendment of layout descriptors
+
+**IMPORTS** -- Existing definition, extended by the following:  
+**Presentation-Time**  
+**FROM Temporal-Relationships { 2 8 1 14 0 }**  
+ -- See ITU-T Rec. T.424 | ISO/IEC 8613-14
+
+**Layout-Object-Descriptor-Body** ::= SET{ -- Existing definition, extended by the following:  
+**presentation-time** [52] IMPLICIT Presentation-Time OPTIONAL}
+
+**Layout-Class-Descriptor-Body** ::= SET{ -- Existing definition, extended by the following:  
+**presentation-time** [52] IMPLICIT Presentation-Time OPTIONAL}
+
+### C.4.4 Amendment of logical descriptors
+
+**IMPORTS** -- Existing definition, extended by the following:  
+**Temporal-Relations**  
+**FROM Temporal-Relationships { 2 8 1 14 0 }**  
+ -- See ITU-T Rec. T.424 | ISO/IEC 8613-14
+
+**Logical-Object-Descriptor-Body** ::= SET{ -- Existing definition, extended by the following:  
+**temporal-relations** [36] IMPLICIT Temporal-Relations OPTIONAL}
+
+**Logical-Class-Descriptor-Body** ::= SET{ -- Existing definition, extended by the following:  
+**temporal-relations** [36] IMPLICIT Temporal-Relations OPTIONAL}
+
+# Annex D
+
+## Examples for specifying temporal relationships
+
+(This annex does not form an integral part of this Recommendation | International Standard)
+
+For better readability, objects are not identified by sequences of integers, as it is the usual way in ODA documents, but by names such as "A" or "B" in the following examples.
+
+### Example 1
+
+Document without any explicitly specified temporal relations.
+
+In this case, the attribute "temporal relations" is not specified in the logical structure, i.e. the default value 'null' is assumed during the layout process.
+
+The layout process does not insert the attribute "presentation time" into the specific layout structure, i.e. the default value 'null' is assumed for the parameter "start time" of this attribute during the presentation process. No time constraints apply during the presentation process. Switching from one page to the next at a computer terminal requires human interaction.
+
+### Example 2
+
+All pages of a document are presented for a specified amount of time, e.g. 20 time units, independent of the content on the page, i.e. independent of the logical structure of the document.
+
+In this case, the attribute "temporal relations" is not specified in the logical structure, i.e. the default value 'null' is assumed during the layout process. The layout process does not insert the attribute "presentation time" into the specific layout structure.
+
+In the generic layout structure, the attribute "presentation time" is specified for the page class(es) to which the pages belong with the following value:
+
+```
+Presentation-Time:  {
+    duration:        {fixed duration: 20}}
+```
+
+According to the defaulting mechanism for the attribute "presentation time", this value applies to all pages of the document, i.e. moving from one page to the next at a computer terminal requires no human interaction but is performed every 20 time units.
+
+### Example 3
+
+Two pieces of content associated with the logical objects A and B are to be presented in sequence; the duration of the first one shall be 20 time units.
+
+In this case, the attribute "temporal relations" is specified for the object immediately superior to the two objects with the following value:
+
+```
+Temporal-Relations: {
+    synchronization-type: sequential,
+    subordinate-nodes:   {
+        (node-identifier: A,
+        duration:        20)
+        (node-identifier: B)}}}
+```
+
+The layout process adds the attribute "presentation time" to the layout object X which receives the content of the logical object A with the following value:
+
+```
+Presentation-Time: {
+    duration:        {fixed duration: 20}}
+```
+
+### Example 4
+
+A piece of content associated with the logical object B is to be presented only after a user interaction is given after the presentation of the content associated with the logical object A.
+
+In this case, the attribute "temporal relations" is specified for the object immediately superior to the two objects with the following value:
+
+```
+Temporal-Relations:      {
+    synchronization-type: sequential,
+    subordinate-nodes:    {
+        (node-identifier: A,
+        duration:         indefinite)
+        (node-identifier: B)}}
+
+```
+
+The layout process adds the attribute "presentation time" to the layout object X which receives the content of the logical object A with the following value:
+
+```
+Presentation-Time:      {
+    duration:             {fixed duration: indefinite}}
+
+```
+
+### Example 5
+
+A piece of audio content associated with the object A is to be presented during the presentation of the content associated with object B, possibly repeatedly, if the presentation of the content of object B takes longer than that of the audio object.
+
+In this case, the attribute "temporal relations" is specified for the document logical root with the following value:
+
+```
+Temporal-Relations:      {
+    synchronization-type: parallel-last,
+    subordinate-nodes:    {
+        (node-identifier: A,
+        duration:         indefinite,
+        cyclic:           {number-of-cycles: indefinite})
+        (node-identifier: B)}}
+
+```
+
+The layout process adds the attribute "presentation time" to the object X which receives the content of the object A with the following value:
+
+```
+Presentation-Time:      {
+    duration:             {fixed duration: indefinite},
+    cyclic:               {number-of-cycles: indefinite}}
+
+```
+
+Note that it is assumed that the presentation process will be terminated by an external event.
+
+### Example 6
+
+A piece of audio content associated with object A is to be presented during the presentation of certain parts of a document, e.g. as long as the content of B, C, and D is presented. The presentation of the audio content shall be repeated, if the presentation of the other content takes longer than that of the audio content.
+
+In this case, the attribute "temporal relations" is specified for the logical object immediately superior to A ... D with the following value:
+
+```
+Temporal-Relations:      {
+    synchronization-type: parallel-last,
+    subordinate-nodes:    {
+        (node-identifier: A,
+        duration:         indefinite,
+        cyclic:           {number-of-cycles: indefinite})
+        (node-identifier: B)
+        (node-identifier: C)
+        (node-identifier: D)}}
+
+```
+
+The layout process adds the attribute "presentation time" to the object X which receives the content of the object A with the following value:
+
+```
+Presentation-Time:      {
+    duration:             {fixed duration: Z},
+    cyclic:               {number-of-cycles: indefinite}}
+
+```
+
+The object Z is the object created by the layout process which contains the content associated with the objects B, C and D. In the case that the layout process creates more than one object, Z shall denote the last of these objects, in sequential layout order.
+
+### **Example 7**
+
+A part of a document may have the following logical structure (see Figure D.1).
+
+![Figure D.1: Logical structure of a document. A hierarchical tree diagram showing a composite logical object E branching into four basic logical objects A, B, C, and D.](32ff77da4286b58c4778033acaa10836_img.jpg)
+
+```
+
+graph TD
+    E[E  
+Composite logical object] --- A[A  
+Basic logical object]
+    E --- B[B  
+Basic logical object]
+    E --- C[C  
+Basic logical object]
+    E --- D[D  
+Basic logical object]
+  
+```
+
+TISO7460-96/d06
+
+Figure D.1: Logical structure of a document. A hierarchical tree diagram showing a composite logical object E branching into four basic logical objects A, B, C, and D.
+
+**Figure D.1 – Logical structure of a document**
+
+The following temporal relationships shall be specified for the objects: the content associated with A and B shall be presented in parallel and the content associated with C and D shall be presented in parallel. The content of the pair (A, B) and of the pair (C, D) shall be presented sequentially and each pair shall be presented for 20 time units.
+
+Therefore, the logical structure has to be changed as follows (see Figure D.2):
+
+![Figure D.2: Modified logical structure of the document. A hierarchical tree diagram showing a composite logical object E branching into two composite logical objects F and G. F branches into A and B, and G branches into C and D.](24a89bcaba787f2bc1721356480a4a01_img.jpg)
+
+```
+
+graph TD
+    E[E  
+Composite logical object] --- F[F  
+Composite logical object]
+    E --- G[G  
+Composite logical object]
+    F --- A[A  
+Basic logical object]
+    F --- B[B  
+Basic logical object]
+    G --- C[C  
+Basic logical object]
+    G --- D[D  
+Basic logical object]
+  
+```
+
+TISO7470-96/d07
+
+Figure D.2: Modified logical structure of the document. A hierarchical tree diagram showing a composite logical object E branching into two composite logical objects F and G. F branches into A and B, and G branches into C and D.
+
+**Figure D.2 – Modified logical structure of the document**
+
+The following specifications have to be made:
+
+For the object E:
+
+```
+Temporal-Relations: {
+  synchronization-type: sequential,
+  subordinate-nodes: {
+    (node-identifier: F,
+    duration: 20)
+    (node-identifier: G,
+    duration: 20)}}}
+```
+
+For the object F:
+
+```
+Temporal-Relations: {
+  synchronization-type: parallel-last,
+  subordinate-nodes: {
+    (node-identifier: A)
+    (node-identifier: B)}}}
+```
+
+For the object G:
+
+```
+Temporal-Relations: {
+  synchronization-type: parallel-last,
+  subordinate-nodes: {
+    (node-identifier: C)
+    (node-identifier: D)}}}
+```
+
+The layout process may create a page X with layout objects T, U, V and W (in this sequential layout order) which contain the content associated with A, B, C and D, respectively (see Figure D.3).
+
+![Figure D.3: Layout structure of the document. A large rectangle labeled 'X' contains four smaller rectangles arranged in a 2x2 grid. The top-left rectangle is labeled 'T', the top-right is 'U', the bottom-left is 'V', and the bottom-right is 'W'.](9edb407536d4d4d4a6ac391527af047c_img.jpg)
+
+TISO7480-96/d08
+
+Figure D.3: Layout structure of the document. A large rectangle labeled 'X' contains four smaller rectangles arranged in a 2x2 grid. The top-left rectangle is labeled 'T', the top-right is 'U', the bottom-left is 'V', and the bottom-right is 'W'.
+
+**Figure D.3 – Layout structure of the document**
+
+The layout process adds the attribute "presentation time" to the objects T and U with the following value:
+
+```
+Presentation-Time: {
+  timing: {fixed timing: 0},
+  duration: {fixed duration: 20}}
+```
+
+The values added to the objects V and W:
+
+```
+Presentation-Time: {
+  timing: {fixed timing: 20},
+  duration: {fixed duration: 20}}
+```
+
+### Example 8:
+
+Same scenario as in the previous example but with the additional constraint, that each page shall be presented for 30 time units.
+
+In this case, the layout process will create two pages Y and Z with the following structure [note that the pair (T, U) requires 20 time units for presentation as well as the pair (V, W), i.e. the two pairs do not fit in the available time span (30 time units) of a single page] (see Figure D.4):
+
+![Figure D.4: Modified layout structure of the document. The diagram shows two pages, X and Y. Page X contains two objects, T and U. Page Y contains two objects, V and W. The objects are arranged in a 2x2 grid within each page frame.](e22af684d8e56d4c61e61bb5ddac1087_img.jpg)
+
+The diagram illustrates the modified layout structure of the document. It shows two pages, X and Y. Page X contains two objects, T and U. Page Y contains two objects, V and W. The objects are arranged in a 2x2 grid within each page frame. The label 'X' is in the top-left corner of the first frame, and 'Y' is in the top-left corner of the second frame. The objects T, U, V, and W are centered within their respective rectangular frames.
+
+TISO7490-96/d09
+
+Figure D.4: Modified layout structure of the document. The diagram shows two pages, X and Y. Page X contains two objects, T and U. Page Y contains two objects, V and W. The objects are arranged in a 2x2 grid within each page frame.
+
+**Figure D.4 – Modified layout structure of the document**
+
+In this case, the layout process adds the attribute "presentation time" to the objects T, U, V and W with the following value:
+
+**Presentation-Time:** {  
+    **timing:** {fixed timing: 0}}
+
+Furthermore, the value for the two pages is:
+
+**Presentation-Time:** {  
+    **duration:** {fixed duration: 30}}
+
+### Example 9
+
+The content of a particular area on a page shall vary with time, e.g. from time  $t_1$  to  $t_2$  character text shall be presented, from  $t_3$  to  $t_4$  a video, from  $t_5$  to  $t_6$  raster graphics.
+
+This effect can be achieved with overlapping frames. The layout process may have created the following layout structure (note that the reference layout process does not deal with overlapping frames; therefore, the original logical structure is not considered in this example) (see Figure D.5):
+
+![Figure D.5: Layout structure of a document. A hierarchical tree diagram showing the structure of a document. The root node is 'A Page'. It branches into four nodes: 'B Frame', 'C Frame', 'D Frame', and 'E Frame'. Each of these nodes further branches into a corresponding block node: 'F Block', 'G Block', 'H Block', and 'I Block' respectively.](762a17cd79880dbca172bcbbe9375223_img.jpg)
+
+```
+
+graph TD
+    A[A Page] --> B[B Frame]
+    A --> C[C Frame]
+    A --> D[D Frame]
+    A --> E[E Frame]
+    B --> F[F Block]
+    C --> G[G Block]
+    D --> H[H Block]
+    E --> I[I Block]
+
+```
+
+TISO7500-96/d10
+
+Figure D.5: Layout structure of a document. A hierarchical tree diagram showing the structure of a document. The root node is 'A Page'. It branches into four nodes: 'B Frame', 'C Frame', 'D Frame', and 'E Frame'. Each of these nodes further branches into a corresponding block node: 'F Block', 'G Block', 'H Block', and 'I Block' respectively.
+
+**Figure D.5 – Layout structure of a document**
+
+Depending on the point in time, the following content of the page shall be shown (See Figure D.6):
+
+![Figure D.6 – Temporally overlapping frames. The diagram shows three vertical frames representing different time intervals. Frame 1 (left) is labeled t1 ≤ t ≤ t2 and contains 'Content of block F' and 'Character text (G)'. Frame 2 (middle) is labeled t3 ≤ t ≤ t4 and contains 'Content of block F' and 'Video (H)'. Frame 3 (right) is labeled t5 ≤ t ≤ t6 and contains 'Content of block F' and 'Raster graphics (I)'. The frames are temporally overlapping, meaning their time intervals intersect. A reference 'TISO7510-96/d11' is at the bottom right.](41aef1f5efab13d4f38f69e86c726062_img.jpg)
+
+Figure D.6 – Temporally overlapping frames. The diagram shows three vertical frames representing different time intervals. Frame 1 (left) is labeled t1 ≤ t ≤ t2 and contains 'Content of block F' and 'Character text (G)'. Frame 2 (middle) is labeled t3 ≤ t ≤ t4 and contains 'Content of block F' and 'Video (H)'. Frame 3 (right) is labeled t5 ≤ t ≤ t6 and contains 'Content of block F' and 'Raster graphics (I)'. The frames are temporally overlapping, meaning their time intervals intersect. A reference 'TISO7510-96/d11' is at the bottom right.
+
+**Figure D.6 – Temporally overlapping frames**
+
+The following specifications have to be made:
+
+For the object C:
+
+**Presentation-Time:** {  
+**timing:** {fixed timing:  $t_1$ },  
+**duration:** {fixed duration:  $t_2-t_1$ }}
+
+For the object D:
+
+**Presentation-Time:** {  
+**timing:** {fixed timing:  $t_3$ },  
+**duration:** {fixed duration:  $t_4-t_3$ }}
+
+For the object E:
+
+**Presentation-Time:** {  
+**timing:** {fixed timing:  $t_5$ },  
+**duration:** {fixed duration:  $t_6-t_5$ }}
+
+Note that  $t_2 \leq t_3$  or  $t_4 \leq t_5$  is not necessarily required.
+
+For  $t_3 < t_2$  or  $t_5 < t_4$  the presentation of the content in the different frames will overlap in time.
+
+### Example 10
+
+Similar scenario to the previous example. However, the presentation of the character text shall continue until the occurrence of an external event (e.g. user interaction), then the video will start and afterwards the raster graphics will be presented for 20 time units.
+
+In this case, the following specifications have to be made:
+
+For the object C:
+
+**Presentation-Time:** {  
+**duration:** {fixed duration: indefinite}}
+
+For the object E:
+
+**Presentation-Time:** {  
+**duration:** {fixed duration: 20}}
+
+The attribute "presentation time" is not required for the object D since it follows object C in sequential layout order.
+
+### Example 11
+
+Specification of temporal relations between content associated with several objects.
+
+A document may have the following logical structure (see Figure D.7):
+
+![Figure D.7: Logical structure of a document. A hierarchical tree diagram showing the logical structure of a document. The root node is 'A Document logical root'. It branches into two nodes: 'B Composite logical object' and 'C Composite logical object'. Node 'B' branches into 'D Audio object' and 'E Basic logical object'. Node 'C' branches into 'F Composite logical object' and 'G Basic logical object'. Node 'F' branches into 'H Basic logical object' and 'I Basic logical object'.](ec3647789b5c38fb686f2a0833324e79_img.jpg)
+
+```
+
+graph TD
+    A["A  
+Document logical root"] --> B["B  
+Composite logical object"]
+    A --> C["C  
+Composite logical object"]
+    B --> D["D  
+Audio object"]
+    B --> E["E  
+Basic logical object"]
+    C --> F["F  
+Composite logical object"]
+    C --> G["G  
+Basic logical object"]
+    F --> H["H  
+Basic logical object"]
+    F --> I["I  
+Basic logical object"]
+  
+```
+
+TISO7520-96/d12
+
+Figure D.7: Logical structure of a document. A hierarchical tree diagram showing the logical structure of a document. The root node is 'A Document logical root'. It branches into two nodes: 'B Composite logical object' and 'C Composite logical object'. Node 'B' branches into 'D Audio object' and 'E Basic logical object'. Node 'C' branches into 'F Composite logical object' and 'G Basic logical object'. Node 'F' branches into 'H Basic logical object' and 'I Basic logical object'.
+
+**Figure D.7 – Logical structure of a document**
+
+For instance, the semantic meaning of B and C may be a "chapter", the content associated with D may be audio content, the content associated with E, G, H and I may be character content.
+
+Now the following temporal relations have to be added:
+
+- D (the audio content) should be presented (possibly repeatedly) as long as E, F, and G are presented;
+- E, F and G should be presented sequentially with a specified time delay;
+- H and I should be presented in parallel.
+
+Therefore, the logical structure of the document is modified as follows (see Figure D.8):
+
+![A hierarchical tree diagram showing the modified logical structure of a document. The root node is 'A Document logical root'. It branches into 'B Composite logical object' and 'C Composite logical object'. Node 'B' further branches into 'D Audio object' and 'K Composite logical object'. Node 'K' branches into 'E Basic logical object', 'F Composite logical object', and 'G Basic logical object'. Node 'F' branches into 'H Basic logical object' and 'I Basic logical object'.](ae0a735d106290c594b0bafb1f5e72e7_img.jpg)
+
+```
+
+graph TD
+    A["A  
+Document logical root"] --> B["B  
+Composite logical object"]
+    A --> C["C  
+Composite logical object"]
+    B --> D["D  
+Audio object"]
+    B --> K["K  
+Composite logical object"]
+    K --> E["E  
+Basic logical object"]
+    K --> F["F  
+Composite logical object"]
+    K --> G["G  
+Basic logical object"]
+    F --> H["H  
+Basic logical object"]
+    F --> I["I  
+Basic logical object"]
+  
+```
+
+TISO7530-96/d13
+
+A hierarchical tree diagram showing the modified logical structure of a document. The root node is 'A Document logical root'. It branches into 'B Composite logical object' and 'C Composite logical object'. Node 'B' further branches into 'D Audio object' and 'K Composite logical object'. Node 'K' branches into 'E Basic logical object', 'F Composite logical object', and 'G Basic logical object'. Node 'F' branches into 'H Basic logical object' and 'I Basic logical object'.
+
+Figure D.8 – Modified logical structure of the document
+
+The temporal relations are specified by the attribute "temporal relations" as follows:
+
+For the composite logical object B:
+
+**Temporal-Relations:** {  
+**synchronization-type:** parallel-first,  
+**subordinate-node:** {  
+   (node-identifier: K)  
+   (node-identifier: D,  
+   cyclic: {  
+     number-of-cycles: indefinite)}}}
+
+For the composite logical object K:
+
+**Temporal-Relations:** {  
+**synchronization-type:** sequential,  
+**subordinate-node:** {  
+   (node-identifier: E)  
+   (node-identifier: F,  
+   start-time: 20)  
+   (node-identifier: G,  
+   start-time: 50)}}}
+
+For the composite logical object F:
+
+**Temporal-Relations:** {  
+**synchronization-type:** parallel-last,  
+**subordinate-node:** {  
+     **(node-identifier:** H)  
+     **(node-identifier:** I)}}}
+
+The layout process may create the following layout structure (see Figure D.9):
+
+![Figure D.9: Layout structure of the document. A hierarchical tree diagram showing the structure of a document layout. The root node is 'T Document layout root'. It branches into three 'Page set' nodes: 'U Page set', 'V Page set', and 'W Page set'. 'U Page set' contains 'X Page', which contains blocks 'L Block' and 'M Block'. 'V Page set' contains 'Y Page', which contains blocks 'N Block', 'O Block', 'P Block', and 'Q Block'. 'W Page set' contains 'Z Page', which contains blocks 'R Block' and 'S Block'.](7e61b2e2506cc7e5d6e16ce9c9df25bb_img.jpg)
+
+```
+
+graph TD
+    T["T  
+Document layout root"] --> U["U  
+Page set"]
+    T --> V["V  
+Page set"]
+    T --> W["W  
+Page set"]
+    U --> X["X  
+Page"]
+    X --> L["L  
+Block"]
+    X --> M["M  
+Block"]
+    V --> Y["Y  
+Page"]
+    Y --> N["N  
+Block"]
+    Y --> O["O  
+Block"]
+    Y --> P["P  
+Block"]
+    Y --> Q["Q  
+Block"]
+    W --> Z["Z  
+Page"]
+    Z --> R["R  
+Block"]
+    Z --> S["S  
+Block"]
+  
+```
+
+TISO7540-96/d14
+
+Figure D.9: Layout structure of the document. A hierarchical tree diagram showing the structure of a document layout. The root node is 'T Document layout root'. It branches into three 'Page set' nodes: 'U Page set', 'V Page set', and 'W Page set'. 'U Page set' contains 'X Page', which contains blocks 'L Block' and 'M Block'. 'V Page set' contains 'Y Page', which contains blocks 'N Block', 'O Block', 'P Block', and 'Q Block'. 'W Page set' contains 'Z Page', which contains blocks 'R Block' and 'S Block'.
+
+**Figure D.9 – Layout structure of the document**
+
+The pages X, Y and Z may look as follows (see Figure D.10):
+
+![Figure D.10: Pages of the document. Three rectangular boxes representing the visual layout of pages X, Y, and Z. Page X (left) contains a large block labeled 'M (E)'. Page Y (middle) contains a block 'N (E)' at the top, followed by two side-by-side blocks 'O (H)' and 'P (I)', and a block 'Q (G)' at the bottom. Page Z (right) contains a block 'R (G)' at the top and a large block 'S (...)' below it.](fd76efce549d3713543bb5ed9b023c2e_img.jpg)
+
+TISO7550-96/d15
+
+Figure D.10: Pages of the document. Three rectangular boxes representing the visual layout of pages X, Y, and Z. Page X (left) contains a large block labeled 'M (E)'. Page Y (middle) contains a block 'N (E)' at the top, followed by two side-by-side blocks 'O (H)' and 'P (I)', and a block 'Q (G)' at the bottom. Page Z (right) contains a block 'R (G)' at the top and a large block 'S (...)' below it.
+
+**Figure D.10 – Pages of the document**
+
+For simplicity, it may be assumed that the layout objects M, ..., S shown on the pages are blocks. The letters in parentheses shall indicate the basic logic objects whose content is displayed within the particular block. For instance, the content associated with logical object E is laid out in block M on page X and in block N on page Y. (The content of block S may be derived from other logical objects which are not listed in the logical structure shown above.) Pages X and Y shall belong to different page sets, because different layout characteristics may apply to the first page and the succeeding pages of a chapter.
+
+The layout process adds the attribute "presentation time" with the indicated values to the following objects:
+
+Object L (object with associated audio content, not shown in the picture of the pages above, since the audio object has a position and dimension of 'null'):
+
+**Presentation-Time:** {  
+**timing:** {fixed timing: 0},  
+**duration:** {fixed duration: R},  
+**cyclic:** {number-of-cycles: indefinite}}
+
+Note that R is the last layout object in sequential order which contains content associated with the basic logical object G.
+
+Object O:
+
+**Presentation-Time:** {  
+**timing:** {fixed timing: 20}}
+
+Object P:
+
+**Presentation-Time:** {  
+**timing:** {fixed timing: 20}}
+
+Object Q:
+
+**Presentation-Time:** {  
+**timing:** {fixed timing: 50}}
+
+### Example 12
+
+Use of generic layout structures
+
+There are a group of processable documents, each of which consists of a sequence of speeches and a cyclic Background Music (BGM) which begins 20 seconds before the start of the first speech and terminates 15 seconds after the end of the last speech. (1 STU is equal to 1 second hereafter.)
+
+In this case, a generic logical structure and a generic layout structure, as shown in Figure D.11, may be used.
+
+In these generic structures, all the values of "content architecture class" for the basic object class "Talks", "BGM", "Talks Frame" and "BGM Frame" are 'formatted processable audio' which defines a content architecture of sampled sound.
+
+In the generic layout structure, all values of "dimension" and "position" are supposed to be zero, since spatial relation makes no sense here and all the directions of progression of the allocation of any immediately subordinates are "temporal first".
+
+For the page class Page:
+
+**Presentation-Time:** {  
+**duration:** {fixed duration: 900}} -- 15 minutes (=900STU-default) is system constraint
+
+For the frame class Page-Frame:
+
+**Presentation-Time:** {  
+**timing:** {fixed timing: 0},  
+**duration:** {Rule-A}}  
+-- minimum to contain its immediately subordinate in sequential order  
+-- Talks Frame – and acts as a constraint on the other – BGM-Frame
+
+For the frame class Talks-Frame:
+
+**Presentation-Time:** {  
+**timing:** {variable timing:  
+**start-offset:** 20, -- interval for BGM  
+**end-offset:** 15, -- as above  
+**start-separation:** 10 -- inter-speech blanking}}
+
+![Figure D.11 – Generic structures. Two hierarchical diagrams showing logical and layout structures.](3c6151f296d5800335472b7dc00ce423_img.jpg)
+
+```
+
+graph TD
+    GLR[Generic logical root] -- SEQ --> Talks
+    GLR -- SEQ --> BGM
+    Talks -- REP --> Speech
+  
+```
+
+```
+
+graph TD
+    GLR[Generic layout root] --> Page
+    Page --> PFrame[Page frame]
+    PFrame -- SEQ --> TFrame[Talks frame]
+    PFrame -- SEQ --> BFrame[BGM frame]
+    TFrame -- REP --> SFrame[Speech frame]
+  
+```
+
+TISO7560-96/d16
+
+Figure D.11 – Generic structures. Two hierarchical diagrams showing logical and layout structures.
+
+Figure D.11 – Generic structures
+
+For the frame class Speech-Frame:
+
+**Presentation-Time:** {  
+**duration:** Rule-B}
+
+For the frame class BGM-Frame:
+
+**Presentation-Time:** {  
+**cyclic:** {number-of-cycles: indefinite}}
+
+With these generic structures, a specific logical structure, as shown in Figure D.12, is formatted into a specific layout structure, of which time relationships are shown in Figure D.13.
+
+Relations among boxes are defined by "generator for subordinates".
+
+The links from
+
+Talks
+
+Speech
+
+BGM
+
+to
+
+Talks Frame
+
+Speech Frame
+
+BGM Frame
+
+respectively, using "layout style" and "layout object class", are omitted here.
+
+![A hierarchical tree diagram showing a specific logical structure. The root node is 'Specific logical root', which branches into 'T1' and 'B1'. 'T1' branches into 'S1' and 'S2'. 'S1' leads to 'Content: 100 s', and 'S2' leads to 'Content: 200 s'. 'B1' leads to 'Content: 50 s'.](fc02903382cebe6fc11e4c0d74b5313f_img.jpg)
+
+```
+
+    graph TD
+      Root[Specific logical root] --> T1[T1]
+      Root --> B1[B1]
+      T1 --> S1[S1]
+      T1 --> S2[S2]
+      S1 --> C1[Content: 100 s]
+      S2 --> C2[Content: 200 s]
+      B1 --> C3[Content: 50 s]
+  
+```
+
+TISO7570-96/d17
+
+A hierarchical tree diagram showing a specific logical structure. The root node is 'Specific logical root', which branches into 'T1' and 'B1'. 'T1' branches into 'S1' and 'S2'. 'S1' leads to 'Content: 100 s', and 'S2' leads to 'Content: 200 s'. 'B1' leads to 'Content: 50 s'.
+
+**Figure D.12 – A specific structure with audio contents of which durations are 100, 200 and 50 s**
+
+![A timeline diagram showing the time sequence of formatted audio content. It consists of horizontal bars with brackets indicating durations: Page (0 to 900), Page frame (0 to 345), S1 (20 to 120), S2 (130 to 330), and B1 (0 to 345 cyclic).](a0e8fe7862a6d7341faf5dac275277cc_img.jpg)
+
+Page: from 0 to 900
+
+Page frame: from 0 to 345
+
+S1: from 20 to 120      S2: from 130 to 330
+
+B1: from 0 to 345 (cyclic)
+
+TISO7580-96/d18
+
+A timeline diagram showing the time sequence of formatted audio content. It consists of horizontal bars with brackets indicating durations: Page (0 to 900), Page frame (0 to 345), S1 (20 to 120), S2 (130 to 330), and B1 (0 to 345 cyclic).
+
+**Figure D.13 – Time sequence of the formatted audio content**
+
+# **Annex E**
+
+## **Compatibility with earlier editions of ITU-T Rec. T.410-Series | ISO/IEC 8613**
+
+(This annex does not form an integral part of this Recommendation | International Standard)
+
+This annex defines the default behaviour for the presentation of a document, in the case where no explicit specifications are given for the temporal presentation of a document or parts thereof.
+
+The presentation of a document is started by an external event, e.g. by a user request to image a document.
+
+The pages of a document are presented in the order in which they occur in the sequential layout order.
+
+Only one page is presented at any point in time.
+
+The presentation of a page is terminated by an external event (e.g. by user interaction), i.e. the duration is indefinite.
+
+The temporal presentation of all content of the objects on a particular page occurs in parallel.
+
+All content of a page remains visible as long as the page itself is presented. All content of a page disappears as soon as the presentation of the page terminates.
+
+# **Annex F**
+
+## **Summary of ASN.1 object identifiers**
+
+(This annex does not form an integral part of this Recommendation | International Standard)
+
+The following ASN.1 object identifiers are assigned in this Specification:
+
+| ASN.1 object identifier value | Description                                                 | Subclause |
+|-------------------------------|-------------------------------------------------------------|-----------|
+| { 2 8 1 14 0 }                | Identifies module<br>Temporal-Relationships                 | 7.5       |
+| { 2 8 1 14 1 }                | Identifies module<br>Hypermedia-Document-Descriptor         | 8.11.1    |
+| { 2 8 1 14 2 }                | Identifies module<br>Hypermedia-Document-Profile-Descriptor | 8.11.2    |
+| { 2 8 1 14 3 }                | Identifies module<br>Link-Descriptors                       | 8.11.3    |
+
+# **Annex G**
+
+## **Application class tag assignments**
+
+(This annex does not form an integral part of this Recommendation | International Standard)
+
+The following application class tag assignments are made in this Specification:
+
+| Tag                  | Data type                     | Subclause |
+|----------------------|-------------------------------|-----------|
+| <b>APPLICATION 9</b> | Link-or-Link-Class-Identifier | 8.11.3    |
+
+# Index
+
+NOTE – The number associated with the index entry indicates the clause or subclause where the index entry can be found.
+
+- |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
+|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| <p><b>A</b></p> <p>application comments, 7, 8, 9, 10, 18, 19, 20, 30, 31, 32</p> <p><b>C</b></p> <p>cycle duration, 7, 8, 9, 10, 14</p> <p>cycle start time, 7, 8, 9, 10</p> <p>cyclic, 6, 7, 8, 9, 10, 11, 14, 15, 37, 43, 45, 46</p> <p><b>D</b></p> <p>document fragment, 10, 16, 17, 22, 25, 26</p> <p>document presentation time, 4, 14</p> <p>document profile, 17</p> <p>document references list, 20</p> <p>document set, 5, 22, 24, 25, 26, 27</p> <p>document set profile, 5, 21, 22, 25, 26</p> <p>duration, 5, 6, 7, 8, 9, 10, 11, 14, 15, 36, 37, 39, 40, 41, 45, 46, 48</p> <p><b>E</b></p> <p>enciphered link, 5, 16, 17, 26, 34</p> <p>enciphered link part, 26</p> <p>enciphered links, 5, 17</p> <p>end offset, 9</p> <p>end separation, 9</p> <p>end time, 7, 8</p> <p>entry point, 21, 22, 24</p> <p>event, 5, 6, 8, 10, 11, 13, 14, 32, 37, 41, 48</p> <p>external event, 5, 6, 8, 10, 11, 13, 14, 32, 37, 41, 48</p> <p>external references list, 21, 24</p> | <p><b>F</b></p> <p>fixed duration, 9, 10, 11, 14, 36, 37, 39, 40, 41, 45</p> <p>fixed timing, 8, 9, 11, 14, 39, 40, 41, 45</p> <p><b>H</b></p> <p>hypermedia document, 5, 15, 16, 17, 19, 20, 21, 22, 26, 27, 32</p> <p>hypermedia document profile, 20</p> <p><b>I</b></p> <p>indefinite, 6, 7, 8, 9, 10, 11, 14, 15, 37, 41, 43, 45, 46, 48</p> <p>integral link, 16, 21, 24, 25, 27, 34</p> <p>interchange format class, 24, 34</p> <p>internal event, 5</p> <p><b>L</b></p> <p>layout style, 19, 20, 27, 46</p> <p>link, 3, 4, 5, 16, 17, 18, 19, 20, 21, 22, 24, 25, 26, 27, 28, 29, 31, 32, 33, 34</p> <p>link class, 3, 4, 5, 16, 17, 18, 19, 21, 22, 24, 26, 31, 32, 33, 34</p> <p>link classes, 3, 4, 5, 16, 17, 22, 26, 33</p> <p>link identifier, 18, 21, 24</p> <p>link roles, 18, 31, 32</p> <p>links, 3, 4, 5, 16, 17, 18, 20, 21, 22, 24, 26, 27, 28, 31, 33, 34, 35, 46</p> <p><b>M</b></p> <p>maximum duration, 9, 10</p> <p>minimum duration, 9, 10</p> <p><b>N</b></p> <p>node, 7, 15, 16, 20, 21, 22, 24, 27, 36, 37, 39, 43, 44</p> <p>node identifier, 7</p> <p>number of cycles, 7, 8, 9</p> <p><b>O</b></p> <p>ODA version, 24</p> |
+|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+
+## P
+
+parallel first, 7
+
+parallel last, 7
+
+parallel selective, 7
+
+presentation style, 19, 20, 27
+
+presentation time, 4, 5, 6, 8, 9, 10, 11, 12, 13, 14, 18, 20, 33, 36, 37, 39, 40, 41, 45
+
+## R
+
+reference name, 19, 20, 21, 24
+
+reference qualifier, 19, 20, 21, 24
+
+rule A, 9, 10
+
+rule B, 9, 10
+
+## S
+
+sealed, 18, 20, 26, 28, 29, 35
+
+start offset, 9
+
+start separation, 9
+
+start time, 6, 7, 8, 9, 10, 36
+
+subordinate nodes, 7
+
+synchronization type, 7
+
+## T
+
+temporal relations, 4, 5, 6, 7, 11, 12, 18, 20, 27, 33, 36, 37, 38, 41, 42, 43
+
+time scaling, 4
+
+timing, 8, 9, 10, 11, 14, 15, 39, 40, 41, 45
+
+## V
+
+variable timing, 8, 9, 45
+
+# ITU-T RECOMMENDATIONS SERIES
+
+|                 |                                                                                                                |
+|-----------------|----------------------------------------------------------------------------------------------------------------|
+| Series A        | Organization of the work of the ITU-T                                                                          |
+| Series B        | Means of expression                                                                                            |
+| Series C        | General telecommunication statistics                                                                           |
+| Series D        | General tariff principles                                                                                      |
+| Series E        | Telephone network and ISDN                                                                                     |
+| Series F        | Non-telephone telecommunication services                                                                       |
+| Series G        | Transmission systems and media                                                                                 |
+| Series H        | Transmission of non-telephone signals                                                                          |
+| Series I        | Integrated services digital network                                                                            |
+| Series J        | Transmission of sound-programme and television signals                                                         |
+| Series K        | Protection against interference                                                                                |
+| Series L        | Construction, installation and protection of cables and other elements of outside plant                        |
+| Series M        | Maintenance: international transmission systems, telephone circuits, telegraphy, facsimile and leased circuits |
+| Series N        | Maintenance: international sound-programme and television transmission circuits                                |
+| Series O        | Specifications of measuring equipment                                                                          |
+| Series P        | Telephone transmission quality                                                                                 |
+| Series Q        | Switching and signalling                                                                                       |
+| Series R        | Telegraph transmission                                                                                         |
+| Series S        | Telegraph services terminal equipment                                                                          |
+| <b>Series T</b> | <b>Terminal equipments and protocols for telematic services</b>                                                |
+| Series U        | Telegraph switching                                                                                            |
+| Series V        | Data communication over the telephone network                                                                  |
+| Series X        | Data networks and open system communication                                                                    |
+| Series Z        | Programming languages                                                                                          |
\ No newline at end of file
diff --git a/marked/T/T-REC-T.43-199707-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/T/T-REC-T.43-199707-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..3a58f68885c03bc2fb95bb409d68f7f55947475f
--- /dev/null
+++ b/marked/T/T-REC-T.43-199707-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:97adcbdebb3326a1af9817c0266d6c1cef088a8f97dc377b1e5fd01e721d14f7
+size 8269
diff --git a/marked/T/T-REC-T.43-199707-I_PDF-E/5a4e62bead259c258d069fd3663ea670_img.jpg b/marked/T/T-REC-T.43-199707-I_PDF-E/5a4e62bead259c258d069fd3663ea670_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..96ac8d715408913a0e72ef7e5a6e036c21ae73ba
--- /dev/null
+++ b/marked/T/T-REC-T.43-199707-I_PDF-E/5a4e62bead259c258d069fd3663ea670_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:fb99b26638fa2e7f315b53b5100eaf4abc346591d79cdf2b8b226fa02a0a7afe
+size 24425
diff --git a/marked/T/T-REC-T.43-199707-I_PDF-E/c2fc2621e8206d24427b56bcb2398fc0_img.jpg b/marked/T/T-REC-T.43-199707-I_PDF-E/c2fc2621e8206d24427b56bcb2398fc0_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..091611032151b5e624b16727e467f1545c536208
--- /dev/null
+++ b/marked/T/T-REC-T.43-199707-I_PDF-E/c2fc2621e8206d24427b56bcb2398fc0_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:492dce431b6ba4574f52a529583b28dd02b36a30bb5dcc88b2db3c56c7fb3fd5
+size 7549
diff --git a/marked/T/T-REC-T.43-199707-I_PDF-E/raw.md b/marked/T/T-REC-T.43-199707-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..af39a7046b72d9a377ce0ceb8071e4756f345c5d
--- /dev/null
+++ b/marked/T/T-REC-T.43-199707-I_PDF-E/raw.md
@@ -0,0 +1,554 @@
+
+
+![ITU logo: a globe with the letters ITU inside, and a lightning bolt striking the globe.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg)
+
+ITU logo: a globe with the letters ITU inside, and a lightning bolt striking the globe.
+
+INTERNATIONAL TELECOMMUNICATION UNION
+
+# ITU-T
+
+TELECOMMUNICATION  
+STANDARDIZATION SECTOR  
+OF ITU
+
+# T.43
+
+(07/97)
+
+SERIES T: TERMINALS FOR TELEMATIC SERVICES
+
+---
+
+**Colour and gray-scale image representations  
+using lossless coding scheme for facsimile**
+
+ITU-T Recommendation T.43
+
+(Previously CCITT Recommendation)
+
+---
+
+# ITU-T T-SERIES RECOMMENDATIONS **TERMINALS FOR TELEMATIC SERVICES**
+
+*For further details, please refer to ITU-T List of Recommendations.*
+
+# **ITU-T RECOMMENDATION T.43**
+
+# **COLOUR AND GRAY-SCALE IMAGE REPRESENTATIONS USING LOSSLESS CODING SCHEME FOR FACSIMILE**
+
+## **Summary**
+
+This Recommendation defines a colour data representation method in order to make it possible to interchange colour and gray-scale image data using Recommendation T.82 coding scheme over facsimile communication services such as Group 3 and Group 4 facsimile. In this Recommendation, three types of images are treated. The first one is one bit per colour CMY(K) or RGB image. The second one is palettized colour image in which palette tables are specified with CIELAB colour space defined in Recommendation T.42. The last one is continuous-tone colour and gray-scale image specified with CIELAB colour space defined in Recommendation T.42.
+
+## **Source**
+
+ITU-T Recommendation T.43 was prepared by ITU-T Study Group 8 (1997-2000) and was approved under the WTSC Resolution No. 1 procedure on the 2nd of July 1997.
+
+## FOREWORD
+
+ITU (International Telecommunication Union) is the United Nations Specialized Agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the ITU. The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis.
+
+The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics.
+
+The approval of Recommendations by the Members of the ITU-T is covered by the procedure laid down in WTSC Resolution No. 1.
+
+In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC.
+
+## NOTE
+
+In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+## INTELLECTUAL PROPERTY RIGHTS
+
+The ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. The ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process.
+
+As of the date of approval of this Recommendation, the ITU had/had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementors are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database.
+
+© ITU 1997
+
+All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU.
+
+# CONTENTS
+
+|   |                                                                        | <i>Page</i> |
+|---|------------------------------------------------------------------------|-------------|
+| 1 | Scope .....                                                            | 1           |
+| 2 | Field of application .....                                             | 1           |
+| 3 | References .....                                                       | 1           |
+| 4 | Definitions .....                                                      | 1           |
+| 5 | Conventions .....                                                      | 1           |
+| 6 | Image representation method .....                                      | 2           |
+|   | 6.1 Overview .....                                                     | 2           |
+|   | 6.2 Colour representation .....                                        | 2           |
+|   | 6.2.1 One bit per colour CMY(K) or RGB image representation .....      | 2           |
+|   | 6.2.2 Palettized colour image representation .....                     | 3           |
+|   | 6.2.3 Continuous-tone colour and gray-scale image representation ..... | 3           |
+| 7 | Data structure specification .....                                     | 4           |
+|   | 7.1 Overview .....                                                     | 4           |
+|   | 7.2 BCIH structure and entry classification .....                      | 5           |
+|   | 7.2.1 BCIH structure .....                                             | 5           |
+|   | 7.2.2 Definition of entries .....                                      | 5           |
+|   | 7.3 BCID structure and application rule for encoding scheme .....      | 7           |
+|   | 7.3.1 Gray code conversion .....                                       | 8           |
+|   | 7.3.2 Usage of T.82 encoding scheme (JBIG) .....                       | 9           |
+|   | 7.3.3 Other encoding schemes .....                                     | 11          |
+
+
+
+# COLOUR AND GRAY-SCALE IMAGE REPRESENTATIONS USING LOSSLESS CODING SCHEME FOR FACSIMILE
+
+(Geneva, 1997)
+
+## 1 Scope
+
+This Recommendation defines colour and gray-scale image representation and their coding schemes in order to make it possible to interchange colour and gray-scale image data such as one bit per colour CMY(K) or RGB image, palettized colour image, and/or continuous-tone colour and gray-scale image, using lossless coding scheme over a facsimile communication service such as Group 3 or Group 4 facsimile.
+
+Its purpose is to specify representation and lossless coding schemes for three types of colour and gray-scale images. The first one is one bit per colour CMY(K) or RGB image. The second one is palettized colour image. The last one is continuous-tone colour and gray-scale image.
+
+This Recommendation, together with documents such as parts of Recommendations T.4 and T.30, or T.563, T.503 and T.521, will define a colour image data format that may be used by colour facsimile service and by other telematic services.
+
+In this Recommendation, the coding scheme specified in Recommendation T.82 (JBIG) is used for lossless encoding of these three types of colour and gray-scale images. Application of other coding schemes are for further study.
+
+## 2 Field of application
+
+This Recommendation defines a colour data representation and coding scheme which mainly enables a receiver to reproduce colour image data as specified by the sender.
+
+It is assumed that when a service is performed using this Recommendation, all non-basic features are subject to negotiation.
+
+## 3 References
+
+The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; all users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published.
+
+- ITU-T Recommendation T.42 (1996), *Continuous-tone colour representation method for facsimile*.
+- ITU-T Recommendation T.82 (1993) | ISO/IEC 11544:1993, *Information technology – Coded representation of picture and audio information – Progressive bi-level image compression*. (Commonly referred to as JBIG standard)
+
+# 4 Definitions
+
+The definitions in Recommendations T.42 and T.82 apply to this Recommendation unless explicitly amended.
+
+**4.1 JBIG: Joint Bi-level Image Experts Group**, and also shorthand for the encoding method, described in Recommendation T.82, which was defined by this group.
+
+## 5 Conventions
+
+The conventions in Recommendations T.42 and T.82 apply to this Recommendation.
+
+# **6 Image representation method**
+
+## **6.1 Overview**
+
+In this Recommendation, the representation methods for three types of colour and gray-scale images that require lossless coding scheme are defined. The first one is one bit per colour CMY(K) or RGB image. The second one is palettized colour image. The last one is continuous-tone colour and gray-scale image. Some of these images are electronically created under the soft-copy environment. Others may be obtained using scanner and image processing techniques such as the dither method.
+
+As the palettized colour image mode may require accurate reproduction in some cases, this mode has to have accurate colour reproduction possibility. Therefore, the colour palette table data of this mode are specified by the device-independent interchange colour space defined in Recommendation T.42. On the other hand, one bit per colour image mode is specified mainly to reproduce colour image using primary colours.
+
+The following represents an example for the use of one bit per colour CMY(K) or RGB mode:
+
+- A sender creates or generates an original colour image with three or four colour components and one bit per colour component using scanner and image processing techniques such as dither. Each bit-plane indicates the on/off of one of the primary colours. The sender encodes this image using lossless encoding method such as Recommendation T.82 (JBIG). The sender then sends the encoded data with the indication of this mode. The receiver receives the data and represents the image on the CRT (soft-copy) or printer (hard-copy) using their own primary colours. Although the sender adds the information about sender's primary colours and the receiver has high reproduction ability, the receiver may not reproduce the accurate colour image, because the tone reproduction property of the printer depends not only on primaries but also on pel recording size.
+
+The following represents an example for the use of palettized colour image mode:
+
+- A sender creates an original colour image using a colour palette in which table data are specified by a specific device-dependent colour space. This colour space may depend on the primaries, white point and gamma of the sender's CRT. The sender converts the device-dependent colour palette to the palette interchange colour space in which table data are specified by the device-independent colour space defined in Recommendation T.42. The sender then sends the interchange colour palette and the image data encoded with a lossless encoding method such as Recommendation T.82 (JBIG). The receiver receives the interchange colour palette and the encoded image data. The interchange colour palette is converted to the receiver-specific colour palette, which is specified by the receiver's device-dependent hard-copy or soft-copy colour space.
+
+The following represents an example for the use of lossless encoded continuous-tone colour image mode:
+
+- A sender creates or generates an original continuous-tone colour or gray-scale image in the colour space defined in Recommendation T.42. In some high-end applications, they need lossless transmission of these images. This Recommendation supports lossless encoding of these images using, such as Recommendation T.82 (JBIG). In order to obtain high data compression ratio using the lossless encoding methods, Gray code conversion technique is introduced.
+
+## **6.2 Colour representation**
+
+Colour representation defines colour image specification method. In this subclause, three types of colour representation methods are defined.
+
+### **6.2.1 One bit per colour CMY(K) or RGB image representation**
+
+In this mode, the colour image is treated as one bit per colour component type image using CMY(K) or RGB primaries. In one bit per colour type image in three colour primaries (CMY or RGB) or in four colour primaries (CMYK), each bit-plane expresses the following colour primaries as shown in Tables 1 to 3.
+
+**Table 1/T.43 – Colour table for one bit  
+per colour "CMYK" image**
+
+| Bit-plane | Colour primaries |
+|-----------|------------------|
+| MSB       | Cyan             |
+| LSB+2     | Magenta          |
+| LSB+1     | Yellow           |
+| LSB       | Black            |
+
+**Table 2/T.43 – Colour table for one bit  
+per colour "CMY" image**
+
+| Bit-plane | Colour primaries |
+|-----------|------------------|
+| MSB       | Cyan             |
+| LSB+1     | Magenta          |
+| LSB       | Yellow           |
+
+**Table 3/T.43 – Colour table for one bit  
+per colour "RGB" image**
+
+| Bit-plane | Colour primaries |
+|-----------|------------------|
+| MSB       | Red              |
+| LSB+1     | Green            |
+| LSB       | Blue             |
+
+### 6.2.2 Palettized colour image representation
+
+Palettized colour images are expressed by indices of 12 bits or less or optionally 13 to 16 bits. The corresponding colour information of each index is given by the colour palette table, in which each entry consists of three component colour coordinates in CIELAB colour space. Each component of the colour coordinate is represented by 8 bits or 12 bits value specified by Recommendation T.42. A colour palette example that has 236 entries and each component is represented by 8 bits precision is shown in Table 4. A colour palette example that has 128 entries and each component is represented by 12 bits precision is shown in Table 5.
+
+### 6.2.3 Continuous-tone colour and gray-scale image representation
+
+In this mode, the colour image is represented by CIELAB colour space specified in Recommendation T.42 and the gray-scale image is represented by L\* component of CIELAB colour space specified in Recommendation T.42. Each component has 8 bits or less or optionally 9 to 12 bits precision. The data structure for this mode is defined for lossless encoding method. In order to obtain high encoding data efficiency, Gray code conversion is used. Currently sub-sampling is not supported in this Recommendation.
+
+Table 4/T.43 – Colour palette table example  
+for 236 entries and 8 bit accuracy
+
+| Index | Component values (8 bits) |                |                |
+|-------|---------------------------|----------------|----------------|
+|       | L <sup>*</sup>            | a <sup>*</sup> | b <sup>*</sup> |
+| 0     | 255                       | 128            | 96             |
+| 1     | 0                         | 128            | 96             |
+| 2     | 128                       | 128            | 96             |
+| –     | –                         | –              | –              |
+| –     | –                         | –              | –              |
+| –     | –                         | –              | –              |
+| 235   | 220                       | 128            | 220            |
+
+Table 5/T.43 – Colour palette table example  
+for 128 entries and 12 bit accuracy
+
+| Index | Component values (12 bits) |                |                |
+|-------|----------------------------|----------------|----------------|
+|       | L <sup>*</sup>             | a <sup>*</sup> | b <sup>*</sup> |
+| 0     | 4095                       | 2048           | 1536           |
+| 1     | 0                          | 2048           | 1536           |
+| 2     | 2048                       | 2048           | 1536           |
+| –     | –                          | –              | –              |
+| –     | –                          | –              | –              |
+| 127   | 3520                       | 2048           | 3520           |
+
+# 7 Data structure specification
+
+## 7.1 Overview
+
+Lossless encoding method such as JBIG can be used as a coding scheme for colour and gray-scale images. In this encoding, an image is resolved into a set of bit-planes, and each bit-plane is coded by lossless encoding method. In resolving an image into bit-planes, Gray code conversion is only used for continuous-tone image. This data structure is defined as BCIE (Bit-plane Colour Image Entity) consisting of BCIH (Bit-plane Colour Image Header), BCID (Bit-plane Colour Image Data) and ending marker (X'FFA9') as shown in Figure 1.
+
+![](c2fc2621e8206d24427b56bcb2398fc0_img.jpg)
+
+|      |      |               |
+|------|------|---------------|
+| BCIH | BCID | Ending marker |
+|------|------|---------------|
+
+Figure 1/T.43 – Data structure of BCIE
+
+## 7.2 BCIH structure and entry classification
+
+### 7.2.1 BCIH structure
+
+The structure of BCIH (Bit-plane Colour Image Header) is specified in Figure 2. BCIH consists of Magic Number X'FFA8' and two or more entries. G3FAX0/G4FAX0 entry and ECIH (End of Colour Image Header) entries are mandatory. Each entry consists of Entry Marker X'FFE1' or X'FFE3', entry length, FAX identifier *n* and entry data. Format of each entry is specified in the subsequent subclauses.
+
+![Diagram showing the data structure of BCIH. The top row is a table with five columns: 'Magic number', 'Entry 1', 'Entry 2', a dashed box representing more entries, and 'ECIH'. Below this, a callout box shows the structure of an entry, divided into four columns: 'Entry marker', 'Length', 'FAX identifier n', and 'DATA'. Dotted lines connect the 'Entry 1' and 'Entry 2' columns of the top table to the 'Entry marker' and 'Length' columns of the callout box respectively.](5a4e62bead259c258d069fd3663ea670_img.jpg)
+
+|              |         |         |  |      |
+|--------------|---------|---------|--|------|
+| Magic number | Entry 1 | Entry 2 |  | ECIH |
+|--------------|---------|---------|--|------|
+
+  
+
+|              |        |                  |      |
+|--------------|--------|------------------|------|
+| Entry marker | Length | FAX identifier n | DATA |
+|--------------|--------|------------------|------|
+
+Diagram showing the data structure of BCIH. The top row is a table with five columns: 'Magic number', 'Entry 1', 'Entry 2', a dashed box representing more entries, and 'ECIH'. Below this, a callout box shows the structure of an entry, divided into four columns: 'Entry marker', 'Length', 'FAX identifier n', and 'DATA'. Dotted lines connect the 'Entry 1' and 'Entry 2' columns of the top table to the 'Entry marker' and 'Length' columns of the callout box respectively.
+
+Figure 2/T.43 – Data structure of BCIH
+
+### 7.2.2 Definition of entries
+
+#### 7.2.2.1 Entry marker
+
+The entry marker X'FFE1' or X'FFE3' will initiate identification of the entry. Marker X'FFE1' is the same code used in JPEG colour fax as 'APP1' and used when length indication is two octet space. Marker X'FFE3' is used when length indication requires four octet space. Each entry is identified by the FAX identifier N. The FAX identifier N is 6 octets value X'47', X'3m', X'46', X'41', X'58', X'n', where m equals 3 or 4 and n equals 0 to maximum X'FF' (255).
+
+#### 7.2.2.2 G3FAX0/G4FAX0 entry
+
+The magic number of the BCIH and this entry uniquely identifies the image data encoded by lossless coding scheme for colour and gray-scale image FAX application. It defines the version, image size, spatial resolution, encoding method, image type, interleave and number of bits. This entry is mandatory. The data format is as follows:
+
+X'FFE1'(Entry marker), length, FAX-identifier 0, version, image size, spatial resolution, coding method, image type, interleave, number of bits.
+
+The above terms are defined as follows:
+
+- |                     |                                                                                                                                                        |
+|---------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Length:             | (2 octets) Total G3FAX0/G4FAX0 entry field octet count including the octet count itself, but excluding the entry marker.                               |
+| FAX-identifier 0:   | (6 octets) X'47', X'3m', X'46', X'41', X'58', X'00' (m = 3 or 4). This identifier specifies G3FAX0/G4FAX0 entry.                                       |
+| Version:            | (2 octets) X'07CD'. This string specifies the year of approval of the standard, for identification in the case of future revision (for example, 1997). |
+| Spatial resolution: | (2 octets) Pixel density in pels/25.4 mm. The basic value is 200. Allowed values are 200, 300 and 400.                                                 |
+| Coding method:      | (1 octet) The value of this parameter specifies the type of lossless coding method.<br><div style="margin-left: 20px;">0: JBIG (see 7.3.2.1.1)</div>   |
+
+In this Recommendation, only "0: JBIG" is allowed. Other numbers are for further study.
+
+Image type: (1 octet) The value of this parameter specifies the image type:
+
+- 0: 1 bit/colour image (using RGB primaries);
+- 1: 1 bit/colour image (using CMY primaries);
+- 2: 1 bit/colour image (using CMYK primaries);
+- 16: Palettized colour image (using CIELAB  
+8 bits/component precision table);
+- 17: Palettized colour image (using CIELAB  
+12 bits/component precision table);
+- 32: Gray-scale image (using L\*);
+- 48: Continuous-tone colour image (using CIELAB).
+
+Number of bits: (4 octets) The value of this parameter specifies the number of bit-planes. For 1 bit/colour image, palettized image and gray-scale images, the first octet of this parameter specifies the total bit-planes. For continuous-tone colour image, the first octet specifies the number of bit-planes of the first colour component, the second, third and fourth octets specify the second, third and fourth colour components respectively. For example, 1 bit/colour (CMYK) case will be defined as X'04', X'00', X'00', X'00'. The 9 bits entries palette colour case will be defined as X'09', X'00', X'00', X'00'. And the colour continuous-tone using 7 bits for L\*, 4 bits for a\* and 4 bits for b\* case will be defined as X'07', X'04', X'04', X'00'.
+
+Following is an example of the string including the Magic Number and Entry Marker for JBIG coded 1997 G4FAX application at 200 pels/25.4 mm, gray-scale, 12 bits/pel:
+
+Example Code String:
+
+|                  |              |                         |                                          |         |
+|------------------|--------------|-------------------------|------------------------------------------|---------|
+| X'FFA8'          | X'FFE1'      | X'0012'                 | X'47', X'34', X'46', X'41', X'58', X'00' | X'07CD' |
+| Magic Number     | Entry Marker | length                  | FAX identifier 0 " G4FAX '0' "           | version |
+|                  |              |                         |                                          |         |
+| X'00C8'    X'00' | X'20'        | X'0C' X'00' X'00' X'00' |                                          |         |
+| res. 200    JBIG | gray         | 12 bit-planes           |                                          |         |
+
+#### 7.2.2.3 ECIH entry
+
+A special entry, the ECIH entry, is used to signal the end of the bit-plane colour image header. No additional entries may follow the ECIH entry. The identifier is followed immediately by the compressed image data. This entry is mandatory. The data format is as follows:
+
+X'FFE1'(Entry Marker), length, FAX identifier 255.
+
+**Length:** (2 octets) Total ECIH entry field octet count, X'08', including the octet count itself, but excluding the Entry Marker.
+
+**FAX identifier 255:** (6 octets) X'47', X'3m', X'46', X'41', X'58', X'FF' (m = 3 or 4). This identifier specifies ECIH entry.
+
+#### 7.2.2.4 G3FAX/G4FAX option entries
+
+G3FAX/G4FAX option identifiers defined as G3FAX1/G4FAX1 for gamut range and G3FAX2/G4FAX2 for illuminant data defined in B.8.3.1/T.503 and in B.8.3.2/T.503 or in E.6.6/T.4 and in E.6.7/T.4 are also applicable to this Recommendation. G3FAX3/G4FAX3 optional identifier is defined for colour palette table. From G3FAX4/G4FAX4 to G3FAX254/G4FAX254 are reserved for future use.
+
+##### 7.2.2.4.1 G3FAX3/G4FAX3 entry for colour palette table
+
+Colour palette table is specified using the Entry Marker X'FFE3' as follows:
+
+X'FFE3'(Entry Marker), length (4 octets), FAX identifier 3, table ID,  $t_{\text{entries}}$ , colour table data.
+
+**Length:** (4 octets) Total G3FAX3/G4FAX3 entry field octet count including the octet count itself, but excluding the Entry Marker.
+
+|                        |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
+|------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| FAX identifier 3:      | (6 octets) X'47', X'3m', X'46', X'41', X'58', X'03' (m = 3 or 4) This identifier specifies G3FAX3/G4FAX3 entry.                                                                                                                                                                                                                                                                                                                                                                 |
+| Table ID:              | (2 octets) This specifies the type of colour palette table.<br><br>0: table specified in CIELAB space<br>(8 bits/comp. precision)<br><br>4: table specified in CIELAB space<br>(12 bits/comp. precision).                                                                                                                                                                                                                                                                       |
+| T <sub>entries</sub> : | (4 octets) It specifies the number of the colour palette table entries. This value should have the following relations:<br><br>N: Number of bits specified in G3FAX0/G4FAX0.<br><br>mb: octets/component in the table:<br>1: 8 bits precision<br>2: 12 bits precision<br><br>$2^{(N - 1)} < t_{\text{entries}} \leq 2^N$<br><br>$\text{length} = 16 + (3 * t_{\text{entries}} * \text{mb}).$                                                                                    |
+| Colour table data:     | ((3 * t <sub>entries</sub> * mb) octets) This data consists of t <sub>entries</sub> colour palette table entries. Each table entry which consists of 3 components, is in sequential order from index = 0 to index = t <sub>entries</sub> - 1. Each component consists of one or two octets value. Its length is specified by the table ID. Each component value is represented by CIELAB space defined in Recommendation T.42. The representation method is specified in 6.2.2. |
+
+Following is an example of the string for the colour palette table for Table 4. It assumes that the table is specified in CIELAB space (8 bit/comp. precision), t<sub>entries</sub> = 236:
+
+Example Code String:
+
+|                        |                      |                                          |              |                            |
+|------------------------|----------------------|------------------------------------------|--------------|----------------------------|
+| X'FFE3'                | X'000002D4'          | X'47', X'33', X'46', X'41', X'58', X'03' | X'0000'      | X'000000EC'                |
+| Entry Marker           | length               | FAX-identifier " G3FAX '3' "             | table ID = 0 | t <sub>entries</sub> = 236 |
+|                        |                      |                                          |              |                            |
+| X'FF', X'80', X'60'    | X'00', X'80', X'60'  | X'80', X'80', X'60'                      | ...          | X'DC', X'80', X'DC'        |
+| index = 0 (255,128,96) | index = 1 (0,128,96) | index = 2 (128,128,96)                   | ...          | index = 235 (220,128,220)  |
+
+Following is an example of the string for the colour palette table for Table 5. It assumes that the table is specified in CIELAB space (12 bit/comp. precision), t<sub>entries</sub> = 128:
+
+Example Code String:
+
+|                            |                           |                                          |              |                              |
+|----------------------------|---------------------------|------------------------------------------|--------------|------------------------------|
+| X'FFE3'                    | X'00000310'               | X'47', X'34', X'46', X'41', X'58', X'03' | X'0004'      | X'00000080'                  |
+| Entry Marker               | length                    | FAX-identifier " G4FAX '3' "             | table ID = 4 | t <sub>entries</sub> = 128   |
+|                            |                           |                                          |              |                              |
+| X'0FFF', X'0800', X'0600'  | X'0000', X'0800', X'0600' | X'0800', X'0800', X'0600'                | ...          | X'0DC0', X'0800', X'0DC0'    |
+| index = 0 (4095,2048,1536) | index = 1 (0,2048,1536)   | index = 2 (2048,2048,1536)               | ...          | index = 127 (3520,2048,3520) |
+
+## 7.3 BCID structure and application rule for encoding scheme
+
+BCID (Bit-plane Colour Image Data) field contains only coded image data. For JBIG coding method, it contains BIE (Bi-level Image Entity) that consists of BIH (Bi-level Image Header) and BID (Bi-level Image Data).
+
+### 7.3.1 Gray code conversion
+
+In encoding the images specified in this Recommendation by bi-level coding method such as JBIG, an image is resolved into a set of bit-planes, and each bit-plane is coded by this coder. In resolving an image into bit-planes, Gray code conversion is only used for continuous-tone images, specified as image type 32 or 48 in the G3FAX0/G4FAX0 entry.
+
+#### 7.3.1.1 Gray code and natural binary code
+
+The conversion between natural binary code and Gray code is as follows: if the MSB in natural binary code is zero, the MSB in Gray code is zero. Similarly, if the MSB in natural binary code is one, the MSB in Gray code is one. Then, checking the pair bits with the lower bit starting from MSB in natural binary code, each transition (0-to-1, and 1-to-0) produces a "1", each non-transition produces a "0". For example, 13, expressed as (1011) in natural binary code, is expressed as (1110) in Gray code ( $1 \geq 1$ ,  $1\text{-to-}0 \geq 1$ ,  $0\text{-to-}1 \geq 1$ ,  $1\text{-to-}1 \geq 0$ ). The following express the relation between two corresponding representations:
+
+$(a_1, a_2, \dots, a_i, \dots, a_{n-1}, a_n)$  and in Gray code  $(b_1, b_2, \dots, b_i, \dots, b_{n-1}, b_n)$  for  $n$ -bit integer  $N$ .
+
+- 1) Conversion from natural binary code to Gray code:
+
+$$b_1 = a_1$$
+
+$$b_i = a_i \text{ EXOR } a_{i-1} \quad i \geq 2$$
+
+- 2) Conversion from Gray code to natural binary code:
+
+$$a_1 = b_1$$
+
+$$a_i = b_i \text{ EXOR } a_{i-1} \quad i \geq 2 \quad \text{EXOR means exclusive OR.}$$
+
+#### 7.3.1.2 Example of Gray code representation
+
+The following table is the comparison of natural binary and Gray code representation for 4 bits integer.
+
+**Tableau 6/T.43 – The comparison of natural binary code and Gray code for 4 bits integer**
+
+| Natural number (N) | Natural binary code | Gray code |
+|--------------------|---------------------|-----------|
+| 0                  | 0000                | 0000      |
+| 1                  | 0001                | 0001      |
+| 2                  | 0010                | 0011      |
+| 3                  | 0011                | 0010      |
+| 4                  | 0100                | 0110      |
+| 5                  | 0101                | 0111      |
+| 6                  | 0110                | 0101      |
+| 7                  | 0111                | 0100      |
+| 8                  | 1000                | 1100      |
+| 9                  | 1001                | 1101      |
+| 10                 | 1010                | 1111      |
+| 11                 | 1011                | 1110      |
+| 12                 | 1100                | 1010      |
+| 13                 | 1101                | 1011      |
+| 14                 | 1110                | 1001      |
+| 15                 | 1111                | 1000      |
+
+### 7.3.2 Usage of T.82 encoding scheme (JBIG)
+
+The BCID (Bit-plane Colour Image Data) field contains only coded image data. For the JBIG coding method, it contains BIE (Bi-level Image Entity) that consists of BIH (Bi-level Image Header) and BID (Bi-level Image Data). Object identifier of this coding T.43 is specified as {0 0 20 43 0}. In order to simplify the colour facsimile standard, only single progression sequential mode is currently supported. Any other modes are left for further study. This subclause gives a description of the JBIG data structure.
+
+#### 7.3.2.1 BIH and marker classification
+
+The rule of parameter setting in BIH for colour facsimile standard is specified in the following subclause. Marker classification is specified in Recommendation T.82.
+
+##### 7.3.2.1.1 Parameters in BIH
+
+The BIH specifies encoded data structure and coding parameters. Parameters in BIH are precisely specified in Recommendation T.82. Table 7 shows the rule of parameter setting for colour facsimile standard.
+
+**Table 7/T.43 – Parameter setting rule for applying Recommendation T.82 to colour and gray-scale image**
+
+| Parameter      | Meaning                                                | Value                                     | Note                                                       |
+|----------------|--------------------------------------------------------|-------------------------------------------|------------------------------------------------------------|
+| D <sub>L</sub> | Initial layer to be transmitted                        | 0 fixed                                   |                                                            |
+| D              | Number of differential layers                          | 0 fixed                                   |                                                            |
+| P              | Number of binary-planes                                | 1 to 36                                   | (Note 1)                                                   |
+| X <sub>D</sub> | Horizontal image size at layer D                       | –                                         | (Note 4)                                                   |
+| Y <sub>D</sub> | Vertical image size at layer D                         | full range of T.82                        |                                                            |
+| L <sub>0</sub> | Lines per stripe at the lowest resolution              | BASIC: 128<br>OPTION: 1 to Y <sub>D</sub> | (Note 6)                                                   |
+| M <sub>X</sub> | Maximum horizontal offset allowed for AT pixel         | 0 to 127                                  |                                                            |
+| M <sub>Y</sub> | Maximum vertical offset allowed for AT pixel           | 0 fixed                                   |                                                            |
+| HITOLO         | Transmission order of differential layers              | 0 fixed                                   | (Note 2)                                                   |
+| SEQ            | Indication of progressive-compatible sequential coding | 0 fixed                                   | (Note 3)                                                   |
+| ILEAVE         | Interleaved transmission order of multiple bit-plane   | 1 fixed                                   | (Note 3)                                                   |
+| SMID           | Transmission order of stripes                          | 0/1                                       | (Note 3)                                                   |
+| LRLTWO         | Model template type                                    | 0/1                                       | 0: 3-line template<br>1: 2-line template                   |
+| VLENGTH        | Indication of possible use of NEWLEN marker segment    | 0/1                                       | 0: NEWLEN is not used<br>1: NEWLEN may be used<br>(Note 5) |
+
+**Table 7/T.43 – Parameter setting rule for applying Recommendation T.82  
+to colour and gray-scale image (concluded)**
+
+| Parameter | Meaning                                               | Value   | Note            |
+|-----------|-------------------------------------------------------|---------|-----------------|
+| TPDON     | Use of typical prediction for differential layers     | 0 fixed | (Note 2)        |
+| TPBON     | Use of typical prediction for lowest-resolution-layer | 0/1     | 0: OFF<br>1: ON |
+| DPON      | Use of Deterministic Prediction                       | 0 fixed | (Note 2)        |
+| DPPRIV    | Use of private DP table                               | 0 fixed | (Note 2)        |
+| DPLAST    | Use of last DP table                                  | 0 fixed | (Note 2)        |
+
+NOTE 1 – In Recommendation T.82, P specifies number of bit-planes. But in colour facsimile application, P specifies the number of binary-planes which means the total number of bit-planes in all colour planes. Since the maximum value of bit-planes per colour component is 12, and the maximum value of colour component is three, the maximum value of P is 36.
+
+NOTE 2 – These parameters are not applied in single-progression sequential coding. Transmitter shall set "0" to these unused parameters. It is not necessary to recognize these parameters at receiver.
+
+NOTE 3 – These parameters are used for interleaving in multiple-level coding.
+
+NOTE 4 – Parameter X<sub>D</sub>, horizontal image size, shall conform to the values defined in clause 2/T.4 for Group 3 facsimile and clause 3/T.563 for Group 4 facsimile.
+
+NOTE 5 – For details, see 6.2.6.2/T.82.
+
+NOTE 6 – When using this Recommendation, BASIC is 128. OPTIONS shall be negotiated by the appropriate facsimile protocols.
+
+**7.3.2.2 Interleave**
+
+In the JBIG coding, interleaving format is identified by the order of three loops: Stripe, Bit-plane, and Resolution. The order of loops is expressed with the combination of three binary JBIG header parameters: SEQ, ILEAVE, and SMID. In colour facsimile application, colour plane and bit-plane are merged into larger binary-plane loop, and the colour plane is put to the outer loop and bit-plane is put to the inner loop. The order of resolution is put to the outest loop considering the possible extension to future progressive mode.
+
+Considering the above assumptions, possible interleaving schemes are restricted to the following:
+
+- 1) Plane interleave: The order of loops from outer side is (Resolution, Plane, Stripe).
+- 2) Stripe interleave: The order of loops from outer side is (Resolution, Stripe, Plane).
+
+The corresponding JBIG Header parameters are (SEQ = 0, ILEAVE = 1, SMID = 0) for (1), and (SEQ = 0, ILEAVE = 1, SMID = 1) for (2).
+
+Plane interleave may require full image size of memory at the transmitter, and require the same size of memory at the receiver for any printing systems as long as (L,a,b) colour space is used. (If CMY colour space will be specified in a future, colour plane memories can be saved at the receiver in thermal transfer or similar printing systems. It needs only one set of statistics memories for coding.)
+
+Stripe interleave requires only stripe-size memory at the transmitter, and also requires same size memory at the receiver for the ink jet or similar printing systems. However, the number of set of statistics memories for coding will correspond to the number of binary-planes to be coded, as long as SDNORM termination is used.
+
+The basic interleave scheme is stripe interleave and 128 line/stripe can be used without negotiation. Other stripe sizes, for example, 256, 512, 1024 lines in stripe interleave, are for further study. Plane interleave can be used with negotiation, and any stripe size can be used.
+
+10 **Recommendation T.43 (07/97)**
+
+In the binary-plane loop, the order among colour components and bit-planes are as follows:
+
+- One bit per colour mode:
+  - One bit per colour "CMY(K)": C, M, Y, (K)
+  - One bit per colour "RGB": R, G, B
+- Palette colour mode: MSB to LSB
+- Continuous-tone colour and gray-scale image: MSB to LSB of L\*, (MSB to LSB of a\*, MSB to LSB of b\*).
+
+#### 7.3.2.3 The bit order of coded data transmission on communication line
+
+The bit order of the coded data on the communication line is LSB first for each octet.
+
+For example, if the coded data stream, which was shown as an example in Table 26/T.82, is obtained by encoder, it is transmitted following the bit order shown below on the communication line:
+
+Coded data stream:
+
+PSCD: 6989 995c 32ea faa0 .....,
+
+MSB LSB
+
+(Bit expression) 01101001 10001001 10011001 01011100 00110010 11101010 .....,
+
+69 89 99 5c 32 ea
+
+Bit order on the communication line:
+
+First
+
+10010110 10010001 10011001 00111010 01001100 01010111.....
+
+### 7.3.3 Other encoding schemes
+
+For further study.
+
+# ITU-T RECOMMENDATIONS SERIES
+
+|                 |                                                                                                                |
+|-----------------|----------------------------------------------------------------------------------------------------------------|
+| Series A        | Organization of the work of the ITU-T                                                                          |
+| Series B        | Means of expression: definitions, symbols, classification                                                      |
+| Series C        | General telecommunication statistics                                                                           |
+| Series D        | General tariff principles                                                                                      |
+| Series E        | Overall network operation, telephone service, service operation and human factors                              |
+| Series F        | Non-telephone telecommunication services                                                                       |
+| Series G        | Transmission systems and media, digital systems and networks                                                   |
+| Series H        | Audiovisual and multimedia systems                                                                             |
+| Series I        | Integrated services digital network                                                                            |
+| Series J        | Transmission of television, sound programme and other multimedia signals                                       |
+| Series K        | Protection against interference                                                                                |
+| Series L        | Construction, installation and protection of cables and other elements of outside plant                        |
+| Series M        | Maintenance: international transmission systems, telephone circuits, telegraphy, facsimile and leased circuits |
+| Series N        | Maintenance: international sound programme and television transmission circuits                                |
+| Series O        | Specifications of measuring equipment                                                                          |
+| Series P        | Telephone transmission quality, telephone installations, local line networks                                   |
+| Series Q        | Switching and signalling                                                                                       |
+| Series R        | Telegraph transmission                                                                                         |
+| Series S        | Telegraph services terminal equipment                                                                          |
+| <b>Series T</b> | <b>Terminals for telematic services</b>                                                                        |
+| Series U        | Telegraph switching                                                                                            |
+| Series V        | Data communication over the telephone network                                                                  |
+| Series X        | Data networks and open system communication                                                                    |
+| Series Z        | Programming languages                                                                                          |
\ No newline at end of file
diff --git a/marked/T/T-REC-T.431-199209-I_PDF-E/raw.md b/marked/T/T-REC-T.431-199209-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..36ed96caa0a8ff7134105887a69855fa9d73fb0f
--- /dev/null
+++ b/marked/T/T-REC-T.431-199209-I_PDF-E/raw.md
@@ -0,0 +1,645 @@
+
+
+![ITU logo: a globe with the letters ITU inside, crossed by a lightning bolt.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg)
+
+ITU logo: a globe with the letters ITU inside, crossed by a lightning bolt.
+
+INTERNATIONAL TELECOMMUNICATION UNION
+
+# CCITT
+
+THE INTERNATIONAL  
+TELEGRAPH AND TELEPHONE  
+CONSULTATIVE COMMITTEE
+
+## T.431
+
+(09/92)
+
+**TERMINAL EQUIPMENT AND PROTOCOLS  
+FOR TELEMATIC SERVICES**
+
+---
+
+**DOCUMENT TRANSFER AND MANIPULATION  
+(DTAM) – SERVICES AND PROTOCOLS –  
+INTRODUCTION AND GENERAL PRINCIPLES**
+
+![CCITT logo: a stylized globe with the letters CCITT inside.](6ed175c791b5e156d9c98a8dbcc3318c_img.jpg)
+
+CCITT logo: a stylized globe with the letters CCITT inside.
+
+**Recommendation T.431**
+
+---
+
+# FOREWORD
+
+The CCITT (the International Telegraph and Telephone Consultative Committee) is a permanent organ of the International Telecommunication Union (ITU). CCITT is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis.
+
+The Plenary Assembly of CCITT which meets every four years, establishes the topics for study and approves Recommendations prepared by its Study Groups. The approval of Recommendations by the members of CCITT between Plenary Assemblies is covered by the procedure laid down in CCITT Resolution No. 2 (Melbourne, 1988).
+
+Recommendation T.431 was revised by Study Group VIII and was approved under the Resolution No. 2 procedure on the 18 of September 1992.
+
+# --- CCITT NOTE
+
+In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized private operating agency.
+
+© ITU 1993
+
+All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU.
+
+# CONTENTS
+
+|                                                                               | <i>Page</i> |
+|-------------------------------------------------------------------------------|-------------|
+| 1 Scope and field of application .....                                        | 1           |
+| 2 References .....                                                            | 1           |
+| 3 Definitions .....                                                           | 3           |
+| 3.1 DTAM service and protocol definitions .....                               | 3           |
+| 3.2 Reference model definitions .....                                         | 3           |
+| 3.3 Service convention definitions .....                                      | 4           |
+| 4 Abbreviations .....                                                         | 4           |
+| 5 DTAM for Telematic applications – General concepts .....                    | 5           |
+| 5.1 The approach to the integrated Telematic application .....                | 5           |
+| 5.2 General communication functions .....                                     | 5           |
+| 5.2.1 Document bulk transfer .....                                            | 5           |
+| 5.2.2 Remote document manipulations .....                                     | 5           |
+| 5.2.3 Remote document access .....                                            | 6           |
+| 5.2.4 Remote document management .....                                        | 6           |
+| 5.3 Communication support functions .....                                     | 6           |
+| 5.4 Telematic Protocol Architecture (TPA) model .....                         | 6           |
+| 5.5 Intercommunication with other environment .....                           | 8           |
+| 6 Overview of Recommendations T.431 to T.433 .....                            | 8           |
+| 6.1 T.431 introduction and general principles .....                           | 8           |
+| 6.2 T.432 DTAM service definition .....                                       | 8           |
+| 6.3 T.433 DTAM protocol specification .....                                   | 8           |
+| 7 Application rules for communication application profiles .....              | 8           |
+| 7.1 General principle .....                                                   | 8           |
+| 7.2 Service class .....                                                       | 10          |
+| 7.3 Functional units .....                                                    | 10          |
+| 7.4 Communication support functions .....                                     | 10          |
+| 7.5 Use of communication application profile .....                            | 10          |
+| 8 Service classes, functional units and communication support functions ..... | 10          |
+| 8.1 Service classes .....                                                     | 11          |
+| 8.1.1 Document bulk transfer class .....                                      | 11          |
+| 8.1.2 Document manipulation class .....                                       | 11          |
+| 8.1.3 Document bulk transfer and manipulation class .....                     | 11          |
+| 8.1.4 Remote document access class .....                                      | 12          |
+| 8.1.5 Remote document management class .....                                  | 12          |
+| 8.2 Functional units .....                                                    | 12          |
+| 8.2.1 Association use control functional unit (Kernel) .....                  | 12          |
+| 8.2.2 Capability functional unit .....                                        | 12          |
+| 8.2.3 Data transmission functional units .....                                | 12          |
+| 8.2.4 Session management functional unit .....                                | 12          |
+| 8.2.5 Exception report functional unit .....                                  | 12          |
+| 8.2.6 Remote document access functional unit .....                            | 13          |
+| 8.2.7 Remote document management functional unit .....                        | 13          |
+| 8.3 Communication support functions .....                                     | 13          |
+| 8.3.1 Document bulk transfer class .....                                      | 13          |
+| 8.3.2 Document manipulation class .....                                       | 13          |
+| 8.3.3 Document bulk transfer and manipulation class .....                     | 13          |
+| 8.3.4 Remote document access class (RDA) .....                                | 13          |
+| 8.3.5 Remote document management class (RDM) .....                            | 13          |
+
+# INTRODUCTION
+
+This Recommendation is one of a set of T.400-Series Recommendations to facilitate the interconnection of Telematic systems and terminals. It is related to other CCITT Recommendations in the set as defined by the Reference Model for Open Systems Interconnection (see Recommendation X.200). The Reference Model subdivides the area of standardization for interconnection into a series of layers of specification, each of manageable size.
+
+The T.430-Series Recommendations define a Document Transfer and Manipulation (DTAM) Service and specify a DTAM Protocol available within the Application Layer of the Reference Model. The DTAM defined in this series of Recommendations is one of the Application Service Elements (ASE), which is specifically designed for document handling. It is concerned with identifiable bodies of information which can be treated as documents, and which may be stored within open systems or accessed, transferred and manipulated between application processes.
+
+This Recommendation and Recommendations T.432 and T.433 define general principles and application rules, basic DTAM services, and protocol, respectively. They provide sufficient facilities to support DTAM and establish a framework for DTAM management.
+
+This Recommendation defines in an abstract way application rules of the DTAM service. DTAM applications defined using these series of Recommendations are specified in terms of service classes. A service class consists of a combination of functional units and communication support functions.
+
+The term document used in this series of Recommendations covers ODA documents as well as other types of information, e.g. files.
+
+# **DOCUMENT TRANSFER AND MANIPULATION (DTAM) – SERVICES AND PROTOCOLS – INTRODUCCION AND GENERAL PRINCIPLES**
+
+*(revised 1992)*
+
+# **1 Scope and field of application**
+
+This Recommendation defines in an abstract way application rules of the DTAM service. Applications defined using this series of Recommendations are specified in terms of service classes. A service class consists of a combination of functional units and communication support functions. The combination of functional units and communication support functions are
+
+## 1) *Functional units provided by DTAM*
+
+- association use control unit (Kernel);
+- capability unit;
+- document bulk transfer unit;
+- document unconfirmed manipulation unit;
+- document confirmed manipulation unit (see Note);
+- typed data transfer unit;
+- remote document management unit (see Note);
+- remote document access unit (see Note);
+- token control unit;
+- exception report unit (see Note).
+
+*Note* – The use of these functional units is left for further study.
+
+## 2) *Communication support functions*
+
+- Association Control Service Element (ACSE) and Presentation layer service;
+- Reliable Transfer Service Element (RTSE);
+- Remote Operation Service Element (ROSE) (see Note);
+- Session service (see Recommendation X.215) according to the rule of Recommendation T.62 *bis*.
+
+*Note* – The use of this communication support function is left for further study.
+
+# **2 References**
+
+- Recommendation T.62 *bis*, *Telematic control procedures for Teletex and Group 4 Facsimile Services based on Recommendations X.215 and X.225*.
+- Recommendation T.400, *Introduction to Document Architecture, Transfer and Manipulation*.
+- Recommendation T.411, *Open Document Architecture (ODA) and Interchange Format – Introduction and General Principles*.
+- Recommendation T.412, *Open Document Architecture (ODA) and Interchange Format – Document Structures*.
+- Recommendation T.414, *Open Document Architecture (ODA) and Interchange Format – Document Profile*.
+- Recommendation T.415, *Open Document Architecture (ODA) and Interchange Format – Open Document Interchange Format (ODIF)*.
+
+- Recommendation T.416, *Open Document Architecture (ODA) and Interchange Format – Character Content Architectures.*
+- Recommendation T.417, *Open Document Architecture (ODA) and Interchange Format – Raster Graphics Content Architectures.*
+- Recommendation T.418, *Open Document Architecture (ODA) and Interchange Format – Geometric Graphics Content Architectures.*
+- Recommendation T.432, *Document Transfer and Manipulation (DTAM) – Services and protocols: Service Definition.*
+- Recommendation T.433, *Document Transfer and Manipulation (DTAM) – Services and protocols: Protocol Specification.*
+- Recommendation T.441, *Document Transfer and Manipulation (DTAM) – Operational Structure.*
+- Recommendation X.200, *Open Systems Interconnection (OSI) - Model and Notation – Reference Model of Open Systems Interconnection for CCITT Applications.*
+- Recommendation X.208, *Open Systems Interconnection (OSI) – Model and Notation – Specification of Abstract Syntax Notation One (ASN.1).*
+- Recommendation X.209, *Open Systems Interconnection (OSI) – Model and Notation – Specification of Basic Encoding Rules for Abstract Syntax Notation One (ASN.1).*
+- Recommendation X.210, *Open Systems Interconnection (OSI) – Service Definitions – Open Systems Interconnection Layer Service Definition Conventions.*
+- Recommendation X.215, *Open Systems Interconnection (OSI) – Service Definitions – Session Service Definition for Open Systems Interconnection for CCITT Applications.*
+- Recommendation X.216, *Open Systems Interconnection (OSI) – Service Definitions – Presentation Service Definition for Open Systems Interconnection for CCITT Applications.*
+- Recommendation X.217, *Open Systems Interconnection (OSI) – Service Definitions – Association Control Service Definition for Open Systems Interconnection for CCITT Applications.*
+- Recommendation X.218, *Open Systems Interconnection (OSI) – Service Definitions – Reliable Transfer: Model and Service Definition.*
+- Recommendation X.219, *Open Systems Interconnection (OSI) – Service Definitions – Remote Operation: Model, Notation and Service Definition.*
+- Recommendation X.225, *Open Systems Interconnection (OSI) – Protocol Specifications – Session Protocol Specification for Open Systems Interconnection for CCITT Applications.*
+- Recommendation X.226, *Open Systems Interconnection (OSI) – Protocol Specifications – Presentation Protocol Specification for Open Systems Interconnection for CCITT Applications.*
+- Recommendation X.227, *Open Systems Interconnection (OSI) – Protocol Specifications – Association Control Protocol Specification for Open Systems Interconnection for CCITT Applications.*
+- Recommendation X.228, *Open Systems Interconnection (OSI) – Protocol Specifications – Reliable Transfer Protocol Specification for Open Systems.*
+- Recommendation X.400, *Message handling systems: Message handling system and service overview.*
+
+# 3 Definitions
+
+Unless explicitly, all terms apply to the view of a system presented for the purpose of open systems interconnection. This implies that the terms relate to a DTAM rather than to any real documents in local system.
+
+The definitions are grouped into major categories, and ordered alphabetically within each category.
+
+For the purpose of T.430-Series Recommendations, the following definitions apply:
+
+## 3.1 *DTAM service and protocol definitions*
+
+The following definitions are applied to the series of Recommendations T.431 to T.433, in addition to the definitions defined in other T.400-Series Recommendations:
+
+### 3.1.1 **document bulk transfer**
+
+Bulk transmission of a document as a whole.
+
+### 3.1.2 **document bulk transfer and manipulation**
+
+An arbitrary combination of document bulk transfer and document manipulation.
+
+### 3.1.3 **document manipulation**
+
+Creation, deletion or modification of one or more constituents or substructures of a document.
+
+### 3.1.4 **DTAM user**
+
+That portion of the application entity which conceptually invokes the DTAM service.
+
+### 3.1.5 **remote document access**
+
+Document selection and access rights via communication.
+
+### 3.1.6 **remote document management**
+
+Document creation or deletion via communication.
+
+### 3.1.7 **service element**
+
+A unit of standardization specifying a complete group of functions.
+
+### 3.1.8 **service primitive**
+
+The smallest defined interaction between the user and the provider of a communication service.
+
+## 3.2 *Reference model definitions*
+
+T.430-Series Recommendations are based on the concept developed in Recommendation X.200 and make use of the following terms defined in it:
+
+- a) application-entity;
+- b) application-process;
+- c) application service element;
+- d) (N)-connection;
+
+- e) open system;
+- f) (N)-protocol;
+- g) (N)-protocol-control-information;
+- h) (N)-protocol-data-unit;
+- i) (N)-service;
+- j) (N)-service-access-point;
+- k) (N)-service-access-point-address;
+- l) (N)-service-data-unit;
+- m) (N)-user-data;
+- n) user element.
+
+## 3.3 *Service convention definitions*
+
+T.430-Series Recommendations make use of the following terms defined in Recommendation X.210 as they apply to the DTAM service:
+
+- a) confirm;
+- b) indication;
+- c) primitive;
+- d) request;
+- e) response;
+- f) service provider;
+- g) service user.
+
+# 4 **Abbreviations**
+
+Abbreviations defined in other Recommendations of the T.400-Series apply also to this Recommendation. T.430-Series Recommendations also use the following abbreviations:
+
+|        |                                               |
+|--------|-----------------------------------------------|
+| ACSE   | Association Control Service Element           |
+| APDU   | Application Protocol Data Unit                |
+| ASE    | Application Service Element                   |
+| BT     | Document Bulk transfer class                  |
+| BTM    | Document Bulk transfer and Manipulation class |
+| DM     | Document Manipulation class                   |
+| MHS-SE | Message Handling System Service Element       |
+| OSI    | Open Systems Interconnection                  |
+| PSAP   | Presentation Service Access Point             |
+| ROSE   | Remote Operation Service Element              |
+| RTSE   | Reliable Transfer Service Element             |
+| TPA    | Telematic Protocol Architecture               |
+| M      | Mandatory                                     |
+| O      | Optional                                      |
+| *      | At least one selection                        |
+| –      | Not permitted                                 |
+
+# 5 DTAM for Telematic applications – General concepts
+
+## 5.1 *The approach to the integrated Telematic application*
+
+T.400-Series Recommendations specify the integrated approach for the Telematic application by defining the Document Transfer and Manipulation (DTAM) which is the common communication function for Telematic services located in the OSI application layer.
+
+DTAM provides document handling facilities in order to realize document bulk transfer, document manipulation, document access and document management for various Telematic applications such as G4 facsimile, mixed mode, processable mode, Videotex, and so on.
+
+## 5.2 *General communication functions*
+
+DTAM provides the following general communication functions.
+
+### 5.2.1 *Document bulk transfer*
+
+This function is used to transfer a document from one system to another in an end-to-end communication. Two modes are defined to perform Document Bulk Transfer:
+
+#### a) *Normal Mode*
+
+Document bulk transfer is ensured in conjunction with the use of ACSE, RTSE and presentation.
+
+#### b) *Transparent Mode*
+
+DTAM protocol elements are directly mapped to the session layer. This mode is only applicable to facsimile Group 4 application.
+
+### 5.2.2 *Remote document manipulations*
+
+An operation can be applied to one or more constituents or a substructure of document and/or the application defined structures such as the operational structure. Operations applying to more than one constituent or a substructure are performed by applying the operation to each of the constituents or the substructures. The operations used by the application have to obey certain rules. Detail specification of the operational structure is described in Recommendation T.441.
+
+#### 5.2.2.1 *Operations for manipulations*
+
+##### 1) *Create operation*
+
+The create operation effects the addition of a constituent to the document or to the application defined structure.
+
+The create operation may carry the constituents, including the values applicable to the created constituent. If attributes are not set by the operation, they are set to their default values (if defined) or remain undefined otherwise. The relationship attributes of the superior are not implicitly modified by the create operation.
+
+##### 2) *Delete operation*
+
+The delete operation provokes the deletion of the identified constituent and all subordinates. The relationship attributes of the superior constituents are not implicitly modified by the delete operation.
+
+*Note* – If content portions are deleted as subordinates of either layout or logical structure, it is the responsibility of the application to ensure that they are also deleted for the complementary structure.
+
+##### 3) *Modify operation*
+
+For the identified constituent, the modify operation assigns new values to the mentioned attributes. Attributes not mentioned in a modify operation remain unchanged. Identification attributes are used in a modify operation to identify the concerned constituent. They are set at the time of the creation of the object or content portion and remain unchanged by modify operations. Other invariable attributes must not occur in this operation.
+
+Whenever applying one of the concerned operations, it is the responsibility of the application to ensure consistency of the document.
+
+##### 4) *Call operation*
+
+The call operation is used to read an object of the Operational Structure which contains a sequence of DTAM protocol data unit which is applicable to the existing document.
+
+##### 5) *Rebuild operation*
+
+The rebuild operation is for further study.
+
+### 5.2.3 *Remote document access*
+
+For further study.
+
+### 5.2.4 *Remote document management*
+
+For further study.
+
+## 5.3 *Communication support functions*
+
+DTAM makes use of the following services as a communication support function to exchange protocol elements between DTAM Protocol Machines (DTAM-PMs):
+
+- a) the service of session layer defined in Recommendation X.215 according to the rule of Recommendation T.62 *bis*;
+- b) the service of ACSE (Association Control Service Element) and the service of presentation layer;
+- c) the service of RTSE (Reliable Transfer Service Element).
+
+*Note* – The use of ROSE (Remote Operation Service Element) is left for further study.
+
+## 5.4 *Telematic Protocol Architecture (TPA) model*
+
+DTAM operates between two Telematic DTAM Protocol Machines (DTAM-PMs) in the application layer of OSI model. Protocol elements are exchanged between DTAM-PMs, using the service of session layer as defined in Recommendation X.215 according to T.62 *bis* rules, or the services of ACSE (Association Control Service Element), presentation layer services and RTSE (Reliable Transfer Service Element). Telematic Protocol Architecture (TPA) model is shown in Figure 1/T.431. The application layer protocol architecture illustrated in this figure is composed of ACSE, RTSE, DTAM application service element, and DTAM user elements.
+
+Inclusion of ROSE element in TPA is left for further study.
+
+![A diagram of the Telematic Protocol Architecture (TPA) model. At the top is the 'DTAM user element' (oval) connected to the 'DTAM service' (dashed box) via a double-headed arrow. The 'DTAM service' is labeled 'Rec. T.400'. Inside it is the 'DTAM service element' (solid box). This element contains a 'Document Body ODA' (solid box) and 'Functional units' (solid box). The 'Document Body ODA' includes 'File', 'Operational structure', 'Document architecture', and 'Content architecture'. The 'Functional units' list: Association use control, Capability, Document Transfer, Document Manipulation, Typed Date Transmission, Exception Report, and Token Control. To the right of the 'DTAM service element' is the 'DTAM protocol' (vertical oval). Arrows labeled 'Interchange Format' and 'Document Transfer, Document Manipulation, Typed data Transfer, etc.' connect the 'Document Body ODA' and 'Functional units' to the 'DTAM protocol'. Below the 'DTAM service' is the 'RTSE' (solid box) with '(Note 2)' below it. Below 'RTSE' is the 'ACSE' (solid box). To the right of 'ACSE' is 'Association control' and 'Context control' with an arrow pointing to a small circle. Below 'ACSE' is the 'Presentation service' (solid box). To the left of 'Presentation service' is 'PSAP' (oval). Below 'Presentation service' is the 'Session service' (solid box) with '(Note 1)' above it. Arrows show bidirectional communication between 'DTAM service element', 'RTSE', 'ACSE', 'Presentation service', and 'Session service'. A reference 'T0805400-90/d01' is at the bottom right of the diagram.](cfef993dcc8fb513de79eb1f93cf26ae_img.jpg)
+
+A diagram of the Telematic Protocol Architecture (TPA) model. At the top is the 'DTAM user element' (oval) connected to the 'DTAM service' (dashed box) via a double-headed arrow. The 'DTAM service' is labeled 'Rec. T.400'. Inside it is the 'DTAM service element' (solid box). This element contains a 'Document Body ODA' (solid box) and 'Functional units' (solid box). The 'Document Body ODA' includes 'File', 'Operational structure', 'Document architecture', and 'Content architecture'. The 'Functional units' list: Association use control, Capability, Document Transfer, Document Manipulation, Typed Date Transmission, Exception Report, and Token Control. To the right of the 'DTAM service element' is the 'DTAM protocol' (vertical oval). Arrows labeled 'Interchange Format' and 'Document Transfer, Document Manipulation, Typed data Transfer, etc.' connect the 'Document Body ODA' and 'Functional units' to the 'DTAM protocol'. Below the 'DTAM service' is the 'RTSE' (solid box) with '(Note 2)' below it. Below 'RTSE' is the 'ACSE' (solid box). To the right of 'ACSE' is 'Association control' and 'Context control' with an arrow pointing to a small circle. Below 'ACSE' is the 'Presentation service' (solid box). To the left of 'Presentation service' is 'PSAP' (oval). Below 'Presentation service' is the 'Session service' (solid box) with '(Note 1)' above it. Arrows show bidirectional communication between 'DTAM service element', 'RTSE', 'ACSE', 'Presentation service', and 'Session service'. A reference 'T0805400-90/d01' is at the bottom right of the diagram.
+
+*Note 1* – In some applications, APDUs defined in DTAM are directly mapped to session service defined in Recommendation X.215.
+
+*Note 2* – The use of RTSE is only available for Bulk Transfer in normal mode.
+
+FIGURE 1/T.431  
+A basic Telematic Protocol Architecture (TPA) model
+
+## 5.5 *Intercommunication with other environment*
+
+Intercommunication with MHS is for further study.
+
+# 6 **Overview of Recommendations T.431 to T.433**
+
+## 6.1 *T.431 introduction and general principles*
+
+This Recommendation provides information about T.430-Series Recommendations as a whole by way of an introductory description of the DTAM service and protocol, an overview of each of the Recommendations and a description of their interdependencies. References necessary for all T.430-Series Recommendations are given, and terms used throughout all T.430-Series Recommendations are defined. Conformance to T.430-Series Recommendations is specified and rules for defining communication application profiles are given.
+
+## 6.2 *T.432 DTAM service definition*
+
+Recommendation T.432 defines in an abstract way the services provided by an application-service-element, the Document Transfer and Manipulation Service Element (DTAM) to support applications in a distributed Telematic systems environment.
+
+## 6.3 *T.433 DTAM protocol specification*
+
+Recommendation T.433 specifies the protocol for the services provided by an application-service-element, the Document Transfer and Manipulation Service Element (DTAM) to support applications in a distributed Telematic systems environment.
+
+# 7 **Application rules for communication application profiles**
+
+Specific communication application profiles may be defined using this T.430-Series Recommendations according to the rules defined in this section. Definition procedure of a communication application profile is summarized in Figure A-1/T.431.
+
+## 7.1 *General principle*
+
+Tables 1/T.431 and 2/T.431 define permissible combinations of a service class, communication support functions and functional units that may be used to define a communication application profile during the life time of association.
+
+A communication application profile must specify
+
+- 1) a service class;
+- 2) functional units;
+- 3) communications support functions
+
+that are conforming to this Recommendation.
+
+TABLE 1/T.431
+
+### **Services associated with functional units**
+
+| Functional unit |                                          | DTAM service                                                                             | Service classes |    |               | Reference |
+|-----------------|------------------------------------------|------------------------------------------------------------------------------------------|-----------------|----|---------------|-----------|
+|                 |                                          |                                                                                          | BT              | DM | BTM           |           |
+| U1              | Association use control unit             | Establishment                                                                            | M               | M  | M             |           |
+|                 |                                          | Termination                                                                              | M               | M  | M             |           |
+|                 |                                          | Abort                                                                                    | M               | M  | M             |           |
+| U2              | Capability unit                          | Capability                                                                               | O               | O  | O             |           |
+| U3              | Document bulk transfer unit              | Document bulk transfer                                                                   | M               | –  | M             |           |
+| U4              | Document manipulation unit (unconfirmed) | Document unconfirmed manipulation Create, Delete, Modify, Call, Others for further study | –               | M  | M             |           |
+| U5              | Document manipulation unit (confirmed)   | Document confirmed manipulation Create, Delete, Modify, Call, Others for further study   | Further study   |    |               |           |
+| U6              | Typed data transmission unit             | Typed data transfer                                                                      | –               | O  | O             |           |
+| U7              | Token control unit                       | Token control                                                                            | O               | O  | O             |           |
+| U8              | Exception report unit                    | Exception reporting                                                                      | Further study   | –  | Further study |           |
+| U10             | Remote document management unit          | Further study                                                                            | Further study   |    |               |           |
+| U11             | Remote document access unit              | Further study                                                                            | Further study   |    |               |           |
+
+TABLE 2/T.431
+
+### **Summary of service classes**
+
+| Service classes                         |                 | DTAM communication support functions                 |
+|-----------------------------------------|-----------------|------------------------------------------------------|
+| Document bulk transfer (direct)         | BT <sub>0</sub> | Direct mapping to Session service (transparent mode) |
+|                                         | BT <sub>1</sub> | ACSE and RTSE and Presentation service (normal mode) |
+| Document manipulation                   | DM <sub>1</sub> | ACSE and Presentation service                        |
+|                                         |                 |                                                      |
+|                                         |                 |                                                      |
+|                                         |                 |                                                      |
+| Document bulk transfer and manipulation | BTM             | ACSE and RTSE and Presentation service (Note 2)      |
+|                                         |                 |                                                      |
+| Remote document access (Note 2)         | RDA             |                                                      |
+| Remote document management (Note 2)     | RDM             |                                                      |
+
+*Note 1* – BT, DM, BTM, RDA and RDM are used to classify DTAM protocol architecture depending on the combination of communication support function.
+
+*Note 2* – These service classes are left for further study.
+
+## 7.2 *Service class*
+
+This Recommendation defines three service classes that are general communication functions provided by DTAM:
+
+- 1) Document bulk transfer;
+- 2) Document manipulation;
+- 3) Document bulk transfer and manipulation.
+
+Recommendations T.432 and T.433 define all DTAM services and procedures as application protocol that may be used in defining each service class. The application profile must specify the required service class depending on the DTAM application profile requirement.
+
+## 7.3 *Functional units*
+
+Table 1/T.431 defines permissible combinations of a service class and functional units. Functional units are used to simplify the procedure as the application protocol. Recommendations T.432 and T.433 define DTAM service and protocol that may be used in an application profile. This subsection defines the rules for using functional units within an application profile, as follows:
+
+- 1) The communication application profile must specify all functional units conforming to a service class.
+- 2) The communication application profile must specify all DTAM service primitives that are associated with functional units.
+- 3) The communication application profile must specify all parameter sets that are associated with a DTAM service, these service primitives must include parameters that are classified as mandatory in the Recommendation T.432.
+- 4) The communication application profile must specify value and default value of DTAM protocol data handled by a functional unit.
+- 5) The communication application profile may specify or exclude the use of any DTAM service primitives that is classified as a user option in Recommendation T.432.
+- 6) The communication application profile may specify as mandatory the use of any DTAM service primitives that is classified as a user option in Recommendation T.432.
+
+## 7.4 *Communication support functions*
+
+Table 2/T.431 defines permissible combinations of a service class and communication support functions. Recommendation T.433 defines DTAM protocol in conjunction with the Association Control Service Element (ACSE), the Reliable Transfer Service Element (RTSE) and Presentation service or Session service (see Recommendation X.215) according to the rule of Recommendation T.62 *bis*. This subsection defines the rules for using communication support functions within an application profile, as follows:
+
+- The application profile must specify all communication support functions conforming to a service class.
+
+## 7.5 *Use of communication application profile*
+
+A single communication application profile is used for one association. The use of more than one communication application profile during the lifetime of association is for further study.
+
+# 8 **Service classes, functional units and communication support functions**
+
+Functional units and service classes are logical groupings of related DTAM services defined in Recommendation T.432.
+
+## 8.1 *Service classes*
+
+Recommendations T.432 and T.433 define all DTAM services and procedures as application protocol that may be used in defining each service class. Which functional units are mandatory and which are optional in each service class; document bulk transfer, document manipulation and document transfer and manipulation are shown in Table 1/T.431.
+
+### 8.1.1 *Document bulk transfer class*
+
+In terminal-to-terminal communications, there exist bulk document transfer applications transmitting documents as a whole, such as G4 facsimile and mixed-mode communications. In this document bulk transfer applications, a document generated at one system (terminal) is transmitted to another system (terminal).
+
+The document bulk transfer class consists of
+
+- a) association use control functional unit;
+- b) optionally, capability functional unit;
+- c) document bulk transfer functional unit;
+- d) exception report functional unit (see Note);
+- e) optionally, token control functional unit.
+
+*Note* – Use of exception report functional unit is for further study.
+
+### 8.1.2 *Document manipulation class*
+
+In Telematic document data base applications, parts of a document may be transferred to generate a whole document sequentially, concatenating parts stored in different resources. The only document manipulation class can be applied to this application. The document manipulation class consists of
+
+- a) association use control functional unit;
+- b) optionally, capability functional unit;
+- c) document manipulation functional unit (unconfirmed),
+- d) optionally, token control functional unit,
+- e) optionally, typed data transmission functional unit.
+
+### 8.1.3 *Document bulk transfer and manipulation class*
+
+In addition to document transfer applications, there exist conversational applications transmitting documents two-way interactively. This service class is achieved by an arbitrary combination of document bulk transfer and document manipulation. For example, in terminal-to-terminal communications, conversational applications include interactive Telematic services with handwriting and pointing, and interactive remote editing of previously transmitted documents. In host access applications, special characteristics of Document Architecture include the use of soft copy media. These enable partial document manipulations such as modification or deletion of portions of the structured document received from the host. In this application, document structure of a previously transmitted document may be manipulated.
+
+*Note* – In host-to-terminal communications the structured document is transferred as a body part for submission, delivery, filing and retrieval. Applicability to other host-to-terminal communications, such as MHS, document filing and retrieval service, is left for further study.
+
+The document bulk transfer and manipulation class consists of
+
+- a) association use control functional unit;
+- b) optionally, capability functional unit;
+- c) document bulk transfer functional unit;
+
+- d) optionally, exception report functional unit;
+- e) optionally, token control functional unit;
+- f) optionally, typed data transmission functional unit.
+
+### 8.1.4 *Remote document access class*
+
+For further study.
+
+### 8.1.5 *Remote document management class*
+
+For further study.
+
+## 8.2 *Functional units*
+
+### 8.2.1 *Association use control functional unit (Kernel)*
+
+DTAM provides the trigger for the use of the association provided in ACSE, and controls association use during communication. Association use control unit supports basic DTAM services for unique discrimination of both AEs, selection of functional units, establishment, termination and abort of association use.
+
+### 8.2.2 *Capability functional unit*
+
+The DTAM capability functional unit provides the means for invocation or negotiation of application and communication characteristics during an association being in effect up to the next subsequent DTAM capability invocation.
+
+### 8.2.3 *Data transmission functional units*
+
+DTAM provides document transfer methods, such as document bulk transfer, document manipulation and typed data transmission. Data transmission unit consists of the following three units:
+
+#### a) *Document bulk transfer functional unit*
+
+DTAM has a function to transmit the document in bulk to the other DTAM under the communication environment negotiated by D-INITIATE service and additionally by D-CAPABILITY service. The documents represented by ODIF (Document Interchange Format) is transmitted using bulk document transfer unit.
+
+#### b) *Document manipulation functional unit (confirmed or unconfirmed)*
+
+In addition to the above bulk transfer, DTAM provides a function to partially modify a document by generating, revising or deleting structures of an existing document. The DTAM user uses this document manipulation unit to manipulate structures in an existing document.
+
+#### c) *Typed data transmission functional unit*
+
+In host-access applications, data sent to the host by the user are fundamentally unstructured retrieval commands and interrupts such as transmission stop requests. The DTAM has a function to pass such data directly on to the DTAM user as typed data. Typed data transmission unit transmits commands for document filing, document retrieval and interrupt without subjecting to token control.
+
+### 8.2.4 *Session management functional unit*
+
+The DTAM has control functions for conversational control provided by the session layer.
+
+#### – Token control functional unit
+
+Transmission rights required for document transfer and document manipulations are controlled with token control unit.
+
+### 8.2.5 *Exception report functional unit*
+
+For further study.
+
+### 8.2.6 *Remote document access functional unit*
+
+For further study.
+
+### 8.2.7 *Remote document management functional unit*
+
+For further study.
+
+## 8.3 *Communication support functions*
+
+This subsection defines permissible combinations of a service class and communication support functions. Valid combinations of service classes and communication support functions are summarized in Table 2/T.431. Recommendations T.432 and T.433 define DTAM services and procedures that specify two communication support functions: the Association Control Service Element (ACSE) service, the RTSE and the Presentation service (see Recommendation X.216) or Session service (see Recommendation X.215) according to the rule of Recommendation T.62 *bis*. Other communication support functions such as ROSE element are left for further study.
+
+### 8.3.1 *Document bulk transfer class*
+
+#### a) *Use of Recommendation T.62 bis (BT<sub>0</sub>)*
+
+Application Protocol Data Units (APDU) defined in DTAM are directly mapped to Session service defined in Recommendation X.215 according to the rule of Recommendation T.62 *bis*.
+
+#### b) *Use of ACSE, RTSE and Presentation layer services (BT<sub>1</sub>)*
+
+Other Telematic document bulk transfer service classes may be provided in conjunction with the ACSE (see Recommendation X.217), the RTSE (see Recommendation X.218) and the Presentation service (see Recommendation X.216).
+
+*Note* – It is the responsibility of the DTAM implementors to make sure that the “session requirements” parameter in the A-ASSOCIATE request primitive will contain the appropriate value to select Session Capability Data FU.
+
+### 8.3.2 *Document manipulation class*
+
+#### – Use of ACSE and Presentation layer services (DM<sub>1</sub>)
+
+The Telematic document manipulation service classes may be provided in conjunction with the ACSE (see Recommendation X.217), and the Presentation service (see Recommendation X.216).
+
+### 8.3.3 *Document bulk transfer and manipulation class*
+
+#### – Use of ACSE, RTSE and Presentation layer services (DM<sub>1</sub>)
+
+Telematic document bulk transfer and manipulation service classes may be provided in conjunction with the ACSE (see Recommendation X.217), the RTSE (see Recommendation X.218) and the Presentation service (see Recommendation X.216).
+
+### 8.3.4 *Remote document access class (RDA)*
+
+For further study.
+
+### 8.3.5 *Remote document management class (RDM)*
+
+For further study.
+
+(to Recommendation T.431)
+
+### **Summary of the definition procedure of a communication application profile**
+
+![Flowchart illustrating the definition procedure of a communication application profile.](4356776ca004ecba5d599667a155d7d4_img.jpg)
+
+```
+
+graph TD
+    DTAM[DTAM Application profile] --> CAP[Communication Application Profile]
+    DTAM -.-> DAP[Document Application Profile]
+    DTAM -.-> OAP[Operational Application Profile]
+    CAP --> SSC[Select Service Class]
+    SSC --> SFU[Specify: Functional Units]
+    SSC --> SCF[Specify: Communication Support Functions]
+    SFU --> DSP[DTAM service primitives]
+    DSP --> DTP[DTAM protocol parameters values and default value]
+    SCF --> SS[Session service]
+    SS --> DTPS[DTAM protocol parameters mapping to session service]
+    SCF --> ASE[ASEs: ACSE, RTSE Presentation service]
+    ASE --> DTPU[DTAM protocol parameters mapping to underline service]
+  
+```
+
+The diagram illustrates the definition procedure of a communication application profile. It starts with a box labeled "DTAM Application profile". A solid line leads down to "Communication Application Profile", while dashed lines branch off to "Document Application Profile" and "Operational Application Profile". From "Communication Application Profile", a solid line leads down to "Select Service Class". From "Select Service Class", two solid lines branch out: one to "Specify: Functional Units" and another to "Specify: Communication Support Functions". From "Specify: Functional Units", a solid line leads to "DTAM service primitives", which then leads to "DTAM protocol parameters values and default value". From "Specify: Communication Support Functions", two solid lines branch out: one to "Session service" (leading to "DTAM protocol parameters mapping to session service") and another to "ASEs: ACSE, RTSE Presentation service" (leading to "DTAM protocol parameters mapping to underline service").
+
+T0805410-90/d02
+
+Flowchart illustrating the definition procedure of a communication application profile.
+
+FIGURE A-1/T.431
+
+**Defining procedure of communication application profile**
\ No newline at end of file
diff --git a/marked/T/T-REC-T.432-199209-I_PDF-E/07b17a620c75522d53916a11e12d1bff_img.jpg b/marked/T/T-REC-T.432-199209-I_PDF-E/07b17a620c75522d53916a11e12d1bff_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..5fc99987fba1ef8c2973f2cd65a3db761274dc02
--- /dev/null
+++ b/marked/T/T-REC-T.432-199209-I_PDF-E/07b17a620c75522d53916a11e12d1bff_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:9db53a2a11ede7485fecab52783126eee9a422419be667a9541def24e6be4ae6
+size 111364
diff --git a/marked/T/T-REC-T.432-199209-I_PDF-E/1c29dadab94c3fa552d270434db09c81_img.jpg b/marked/T/T-REC-T.432-199209-I_PDF-E/1c29dadab94c3fa552d270434db09c81_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..a1e1c88b375962286f845c1659edeb1e6c4a2f93
--- /dev/null
+++ b/marked/T/T-REC-T.432-199209-I_PDF-E/1c29dadab94c3fa552d270434db09c81_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:8f1ef8d194607b5685ff18987713087a3942eefa5e548a003504775e69079ad9
+size 15434
diff --git a/marked/T/T-REC-T.432-199209-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/T/T-REC-T.432-199209-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..89c28e505e9cdce32fb2aa53b394c33a55ddfbd6
--- /dev/null
+++ b/marked/T/T-REC-T.432-199209-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:118afe5c08efa025ef11153bb2c6dc31d6484aa65b690062c50fd5e674e97a79
+size 8346
diff --git a/marked/T/T-REC-T.432-199209-I_PDF-E/399a5af4f606059626c92c92279d54b7_img.jpg b/marked/T/T-REC-T.432-199209-I_PDF-E/399a5af4f606059626c92c92279d54b7_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..9e1ad584b5610629c8eed132b9775324347673a3
--- /dev/null
+++ b/marked/T/T-REC-T.432-199209-I_PDF-E/399a5af4f606059626c92c92279d54b7_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:f0de264fa0c205b21d67d92bc8ef9cf2ef3f8beb5917f948b31f075a39b1e4e9
+size 18396
diff --git a/marked/T/T-REC-T.432-199209-I_PDF-E/421fc75480c21e7ebb25756826652367_img.jpg b/marked/T/T-REC-T.432-199209-I_PDF-E/421fc75480c21e7ebb25756826652367_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..64615aa2f13334178ae6bb81b999aa9c3addbb39
--- /dev/null
+++ b/marked/T/T-REC-T.432-199209-I_PDF-E/421fc75480c21e7ebb25756826652367_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:d4e885445a461581211c6a8eefaaa13b932665c0d83f04a2a2587460998683e2
+size 23563
diff --git a/marked/T/T-REC-T.432-199209-I_PDF-E/5445597cceefaca1ac89e710fe339325_img.jpg b/marked/T/T-REC-T.432-199209-I_PDF-E/5445597cceefaca1ac89e710fe339325_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..e42cfe5a9e737ac39d2edd377ab4453e4d078680
--- /dev/null
+++ b/marked/T/T-REC-T.432-199209-I_PDF-E/5445597cceefaca1ac89e710fe339325_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:168bd9070656eac7ec83d0f29f67e6c1a19a1aeab604bb9f5a920e7b773c41f9
+size 23870
diff --git a/marked/T/T-REC-T.432-199209-I_PDF-E/5b8a756d9a71c35f17db8bcb90b438a3_img.jpg b/marked/T/T-REC-T.432-199209-I_PDF-E/5b8a756d9a71c35f17db8bcb90b438a3_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..26d6e31c75936a92fd1f72491c282f85199fb887
--- /dev/null
+++ b/marked/T/T-REC-T.432-199209-I_PDF-E/5b8a756d9a71c35f17db8bcb90b438a3_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:58ae81b78dac0107a1c16ce203cde3ef991ec3094537d2ee43f1adc5c734d429
+size 16946
diff --git a/marked/T/T-REC-T.432-199209-I_PDF-E/6ed175c791b5e156d9c98a8dbcc3318c_img.jpg b/marked/T/T-REC-T.432-199209-I_PDF-E/6ed175c791b5e156d9c98a8dbcc3318c_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..278e9a00ab4c90fac74738916b9da28ea2d6318c
--- /dev/null
+++ b/marked/T/T-REC-T.432-199209-I_PDF-E/6ed175c791b5e156d9c98a8dbcc3318c_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:2b3fbff69361396c2a8c02a7508f367639dfb4d7a1ed18e637258ca623369b03
+size 5914
diff --git a/marked/T/T-REC-T.432-199209-I_PDF-E/7133ccf78043568ca62ecbcd43628a4a_img.jpg b/marked/T/T-REC-T.432-199209-I_PDF-E/7133ccf78043568ca62ecbcd43628a4a_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..72682c34efb2ba6621e2baa9860ab6a8053117c4
--- /dev/null
+++ b/marked/T/T-REC-T.432-199209-I_PDF-E/7133ccf78043568ca62ecbcd43628a4a_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:ff2f86b1c0d7b46071c7fbbe046d596c03302d4d4c3eac9d8ee61c0295e93b88
+size 20870
diff --git a/marked/T/T-REC-T.432-199209-I_PDF-E/75e4b78ee25f885d73120e3066a5253e_img.jpg b/marked/T/T-REC-T.432-199209-I_PDF-E/75e4b78ee25f885d73120e3066a5253e_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..f7b03124d1dc37b53dba5ae4b8e288c3b6ac9d33
--- /dev/null
+++ b/marked/T/T-REC-T.432-199209-I_PDF-E/75e4b78ee25f885d73120e3066a5253e_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:6b36e82f84f05922be774e10c569d766409ee978c1fbd180ebd9d3ddc7d7fdfa
+size 17264
diff --git a/marked/T/T-REC-T.432-199209-I_PDF-E/75f0cb39f1cd165dfe4a6aa6c4d9388d_img.jpg b/marked/T/T-REC-T.432-199209-I_PDF-E/75f0cb39f1cd165dfe4a6aa6c4d9388d_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..97d94f275223921a1c582f12a55dddda2c170755
--- /dev/null
+++ b/marked/T/T-REC-T.432-199209-I_PDF-E/75f0cb39f1cd165dfe4a6aa6c4d9388d_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:a91c6c205382af0eedd69f6a78bfd837732368b9dbf4f92022261b260355d7e6
+size 22272
diff --git a/marked/T/T-REC-T.432-199209-I_PDF-E/7a02de7ed198501f7a4f6ca37c3f28c5_img.jpg b/marked/T/T-REC-T.432-199209-I_PDF-E/7a02de7ed198501f7a4f6ca37c3f28c5_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..0f06be56be0bada6b385831654e8c293291c7162
--- /dev/null
+++ b/marked/T/T-REC-T.432-199209-I_PDF-E/7a02de7ed198501f7a4f6ca37c3f28c5_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:7ff2e6d0649e4b007e16b8c61983beec2b2fb830466c4db1f3a67e93f7948fc2
+size 16142
diff --git a/marked/T/T-REC-T.432-199209-I_PDF-E/8c348bf9c2c81b018017ae1d19506a9a_img.jpg b/marked/T/T-REC-T.432-199209-I_PDF-E/8c348bf9c2c81b018017ae1d19506a9a_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..35eb2a4fabc8df5e088998f0842231a754bcf958
--- /dev/null
+++ b/marked/T/T-REC-T.432-199209-I_PDF-E/8c348bf9c2c81b018017ae1d19506a9a_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:45b7661fb4665c2daeb03824d1587e705d33c737f0477ead60ee7204e2affae5
+size 17843
diff --git a/marked/T/T-REC-T.432-199209-I_PDF-E/a7585024ebe2bba8ac0757150a12759a_img.jpg b/marked/T/T-REC-T.432-199209-I_PDF-E/a7585024ebe2bba8ac0757150a12759a_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..a4fe603c0896bdc90098b711b8ca0c3f3119d9e9
--- /dev/null
+++ b/marked/T/T-REC-T.432-199209-I_PDF-E/a7585024ebe2bba8ac0757150a12759a_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:061c313255adbb9a962a6838038d6e2e657b65ec7debf60e0c247c2ca8c4f9a4
+size 15519
diff --git a/marked/T/T-REC-T.432-199209-I_PDF-E/a796a6e439fe5969697f79dc5e124acc_img.jpg b/marked/T/T-REC-T.432-199209-I_PDF-E/a796a6e439fe5969697f79dc5e124acc_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..d42518968793821c55c80c4654ee9fda3d890efb
--- /dev/null
+++ b/marked/T/T-REC-T.432-199209-I_PDF-E/a796a6e439fe5969697f79dc5e124acc_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:d68cf0474768af95e153820ea6e955e5dc6b593bd6abba3a358269968fa76903
+size 17028
diff --git a/marked/T/T-REC-T.432-199209-I_PDF-E/ca5dc5fde2061d0ca2051ef7840fc842_img.jpg b/marked/T/T-REC-T.432-199209-I_PDF-E/ca5dc5fde2061d0ca2051ef7840fc842_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..0d5d33fa6b4bde3fce09186e9a7bf0acbb7b7d20
--- /dev/null
+++ b/marked/T/T-REC-T.432-199209-I_PDF-E/ca5dc5fde2061d0ca2051ef7840fc842_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:8fd039307e84e927a0a8bd018a53457cbb466309daad314b3bab975b3e68a2be
+size 15039
diff --git a/marked/T/T-REC-T.432-199209-I_PDF-E/dbbc0baac7341cda76cc4f8355dce23f_img.jpg b/marked/T/T-REC-T.432-199209-I_PDF-E/dbbc0baac7341cda76cc4f8355dce23f_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..01d3ed85520a9238f9111fd26c78c8f286ed8595
--- /dev/null
+++ b/marked/T/T-REC-T.432-199209-I_PDF-E/dbbc0baac7341cda76cc4f8355dce23f_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:8ba42ab05ee1a9dd2dc1a9b82cc544e2ea7593c0b44f88bb60637a12314aad61
+size 18352
diff --git a/marked/T/T-REC-T.432-199209-I_PDF-E/raw.md b/marked/T/T-REC-T.432-199209-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..1d5a898abbba29ac17df49950597d6d1dbe46354
--- /dev/null
+++ b/marked/T/T-REC-T.432-199209-I_PDF-E/raw.md
@@ -0,0 +1,1403 @@
+
+
+![ITU logo: a globe with the letters ITU inside, crossed by a lightning bolt.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg)
+
+ITU logo: a globe with the letters ITU inside, crossed by a lightning bolt.
+
+INTERNATIONAL TELECOMMUNICATION UNION
+
+# CCITT
+
+THE INTERNATIONAL  
+TELEGRAPH AND TELEPHONE  
+CONSULTATIVE COMMITTEE
+
+## T.432
+
+(09/92)
+
+**TERMINAL EQUIPMENT AND PROTOCOLS  
+FOR TELEMATIC SERVICES**
+
+---
+
+**DOCUMENT TRANSFER AND MANIPULATION  
+(DTAM) SERVICES AND PROTOCOLS –  
+SERVICE DEFINITION**
+
+![CCITT logo: a stylized globe with the letters CCITT inside.](6ed175c791b5e156d9c98a8dbcc3318c_img.jpg)
+
+CCITT logo: a stylized globe with the letters CCITT inside.
+
+**Recommendation T.432**
+
+---
+
+# FOREWORD
+
+The CCITT (the International Telegraph and Telephone Consultative Committee) is a permanent organ of the International Telecommunication Union (ITU). CCITT is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis.
+
+The Plenary Assembly of CCITT which meets every four years, establishes the topics for study and approves Recommendations prepared by its Study Groups. The approval of Recommendations by the members of CCITT between Plenary Assemblies is covered by the procedure laid down in CCITT Resolution No. 2 (Melbourne, 1988).
+
+Recommendation T.432 was revised by Study Group VIII and was approved under the Resolution No. 2 procedure on the 18th of September 1992.
+
+# --- CCITT NOTE
+
+In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized private operating agency.
+
+© ITU 1993
+
+All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU.
+
+# CONTENTS
+
+|      |                                                            | <i>Page</i> |
+|------|------------------------------------------------------------|-------------|
+| 1    | Scope and field of application .....                       | 1           |
+| 2    | References .....                                           | 1           |
+| 3    | Definitions and abbreviations.....                         | 1           |
+| 4    | Conventions.....                                           | 1           |
+| 5    | Model of the DTAM service .....                            | 2           |
+| 6    | DTAM services .....                                        | 3           |
+| 6.1  | DTAM association use control .....                         | 3           |
+| 6.2  | DTAM negotiation capability .....                          | 3           |
+| 6.3  | Document bulk transfer .....                               | 4           |
+| 6.4  | Document unconfirmed manipulations .....                   | 4           |
+| 6.5  | Document confirmed manipulations (for further study) ..... | 4           |
+| 6.6  | Typed data transmission .....                              | 4           |
+| 6.7  | Token control.....                                         | 4           |
+| 6.8  | Exception report.....                                      | 4           |
+| 6.9  | Document selection control (for further study).....        | 4           |
+| 6.10 | Document management (for further study).....               | 5           |
+| 6.11 | Document open control (for further study).....             | 5           |
+| 6.12 | Grouping control (for further study) .....                 | 5           |
+| 7    | Functional units.....                                      | 5           |
+| 7.1  | Association use control functional unit.....               | 5           |
+| 7.2  | Capability functional unit .....                           | 5           |
+| 7.3  | Data transmission functional units.....                    | 6           |
+| 7.4  | Exception report functional unit .....                     | 6           |
+| 7.5  | Session management functional units .....                  | 6           |
+| 7.6  | Other functional units .....                               | 6           |
+| 8    | Service overview .....                                     | 7           |
+| 9    | Service definition .....                                   | 8           |
+| 9.1  | D-INITIATE service.....                                    | 8           |
+| 9.2  | D-TERMINATE service.....                                   | 13          |
+
+|                                         | <i>Page</i> |
+|-----------------------------------------|-------------|
+| 9.3 D-P-ABORT service.....              | 14          |
+| 9.4 D-U-ABORT service.....              | 15          |
+| 9.5 D-CAPABILITY service.....           | 16          |
+| 9.6 D-TRANSFER service.....             | 18          |
+| 9.7 D-TYPED-DATA service.....           | 21          |
+| 9.8 D-UNCONFIRMED-CREATE service.....   | 22          |
+| 9.9 D-UNCONFIRMED-DELETE service.....   | 23          |
+| 9.10 D-UNCONFIRMED-MODIFY service.....  | 24          |
+| 9.11 D-UNCONFIRMED-CALL service.....    | 25          |
+| 9.12 D-UNCONFIRMED-REBUILD service..... | 26          |
+| 9.13 D-TOKEN-GIVE service.....          | 26          |
+| 9.14 D-CONTROL-GIVE service.....        | 27          |
+| 9.15 D-TOKEN-PLEASE service.....        | 27          |
+| 9.16 D-P-EXCEPTION-REPORT service.....  | 29          |
+| 9.17 D-U-EXCEPTION-REPORT service.....  | 29          |
+
+# **INTRODUCTION**
+
+This Recommendation defines the services provided by an application-service-element, the Document Transfer and Manipulation Service Element (DTAM), to support applications in a distributed Telematic systems environment. This Recommendation is one of a set of Recommendations defining the services for sets of application-service-elements specifically used by a number of applications.
+
+
+
+# **DOCUMENT TRANSFER AND MANIPULATION (DTAM) SERVICES AND PROTOCOLS – SERVICE DEFINITION**
+
+*(revised 1992)*
+
+# **1 Scope and field of application**
+
+This Recommendation defines in an abstract way the Document Transfer and Manipulation (DTAM) service within the OSI application layer in terms of
+
+- a) the primitive actions and events of the service;
+- b) the parameter data associated with each primitive action and event;
+- c) the relationship between, and the valid sequences of, these actions and events.
+
+The DTAM service is provided in conjunction with the Reliable Transfer Service Element (RTSE) service (Recommendation X.218), the Association Control Service Element (ACSE) service (Recommendation X.217), and the Presentation service (Recommendation X.216). In the Transparent mode, DTAM service is provided in conjunction with the Session service (Recommendation X.215) according to the rules of Recommendation T.62 *bis*.
+
+This Recommendation does not specify individual implementations or products, nor does it contain the implementation of entities and interfaces within a telematic system.
+
+# **2 References**
+
+References are listed in Recommendation T.431.
+
+## **3 Definitions and abbreviations**
+
+Terms and abbreviations are defined in Recommendation T.431.
+
+# **4 Conventions**
+
+This Recommendation defines services for the DTAM following the descriptive conventions defined in Recommendation X.210. In § 9, the definition of each DTAM service includes a table that lists the parameters of its primitives. For a given primitive, the presence of each parameter is described by one of the following values:
+
+|       |                                                                                                |
+|-------|------------------------------------------------------------------------------------------------|
+| blank | not applicable                                                                                 |
+| M     | presence mandatory                                                                             |
+| U     | presence is a user option                                                                      |
+| C     | presence is conditional on a successful negotiation of another parameter in previous primitive |
+| D     | presence is a DTAM-SE service-provider option                                                  |
+| R     | presence subject to conditions defined in Recommendation X.218                                 |
+| A     | presence subject to conditions defined in Recommendation X.217                                 |
+| P     | presence subject to conditions defined in Recommendation X.216                                 |
+
+In addition, the notation (=) indicates that a parameter value is semantically equal to the value to its left in the table.
+
+# 5 Model of the DTAM service
+
+This Recommendation uses the abstract model for a service defined in the OSI service conventions in Recommendation X.210 (see Note 1). The model defines the interactions between the two DTAM-service-users and the DTAM-service-provider that take place between application entities. Information is passed between a DTAM-service-user and the DTAM-service-provider by DTAM service primitives which may carry parameters.
+
+One of the DTAM-service-users is defined as the initiator and the other is defined as the responder.
+
+The model of the DTAM service is illustrated in Figure 1/T.432.
+
+The DTAM service defines a single activity between the initiator and the responder (see Note 2).
+
+*Note 1* – Recommendation X.210 defines a model for the service provided by a layer of the OSI Reference Model.
+
+*Note 2* – At any one time, an application entity may be involved in more than one instance of the DTAM service activity, and each instance is based on a separate application association.
+
+![Figure 1/T.432: Model of DTAM service. This diagram illustrates the architecture of the DTAM service across two entities: the DTAM user (initiator) and the DTAM user (responder). Each user is connected to a DTAM layer via a 'DTAM service' interface. The DTAM layer in each entity interacts with an 'RTSE' (Remote Transfer Service Element) and an 'ACSE' (Application Context Service Element). The RTSE and ACSE layers are connected to a 'Presentation entity' and a 'Session entity' respectively. The diagram shows various protocols and services: X.218: RTSE service, X.228: RTSE protocol, X.217: ACSE service, X.227: ACSE protocol, X.216, X.226: Protocol, X.215, T.62, T.62 bis procedure, and X.225 Session entity. A legend at the bottom indicates that a dark oval represents 'Normal mode (RTSE is only used for Bulk Transfer)' and a light oval represents 'Transparent mode'. The diagram is labeled 'T0811710-93' in the bottom right corner.](07b17a620c75522d53916a11e12d1bff_img.jpg)
+
+Figure 1/T.432: Model of DTAM service. This diagram illustrates the architecture of the DTAM service across two entities: the DTAM user (initiator) and the DTAM user (responder). Each user is connected to a DTAM layer via a 'DTAM service' interface. The DTAM layer in each entity interacts with an 'RTSE' (Remote Transfer Service Element) and an 'ACSE' (Application Context Service Element). The RTSE and ACSE layers are connected to a 'Presentation entity' and a 'Session entity' respectively. The diagram shows various protocols and services: X.218: RTSE service, X.228: RTSE protocol, X.217: ACSE service, X.227: ACSE protocol, X.216, X.226: Protocol, X.215, T.62, T.62 bis procedure, and X.225 Session entity. A legend at the bottom indicates that a dark oval represents 'Normal mode (RTSE is only used for Bulk Transfer)' and a light oval represents 'Transparent mode'. The diagram is labeled 'T0811710-93' in the bottom right corner.
+
+FIGURE 1/T.432  
+Model of DTAM service
+
+The DTAM is provided in two modes of operations:
+
+### a) *Transparent Mode*
+
+This mode is provided solely to allow interworking with older implementations based on Recommendation T.73 - 1984. This mode implies some restriction in use of DTAM services.
+
+### b) *Normal Mode*
+
+This mode is provided to allow full use of DTAM services based on the OSI service definition and protocol specification.
+
+*Note* – It should be taken into account that in some cases the two modes also differ in the means in which the DTAM services are used. An important example is the use of the D-CAPABILITY service (see also § 6.2).
+
+# 6 DTAM services
+
+This section provides a short description of the services of the DTAM service. The services and the primitives by which they are invoked are defined in § 9. For each service, the user of the service (the application entity that begins the sequence of primitives) is stated.
+
+## 6.1 DTAM association use control
+
+Three services are associated with DTAM association use control:
+
+- a) the DTAM establishment service is used by the initiator to create a DTAM association for the application association linking the two DTAM-service-users;
+- b) the DTAM termination service is used by either the initiator or the responder being subject to owning the data token to dissolve the DTAM association between the DTAM-service-user and the DTAM- service-provider;
+
+*Note* – The DTAM termination service is not restricted to map into A-RELEASE service provided by ACSE or RT-CLOSE service provided by RTSE.
+
+- c) the DTAM abort service is used by either the service users or the service provider to dissolve the DTAM association unconditionally.
+
+## 6.2 DTAM negotiation capability
+
+DTAM negotiation capabilities are expressed by means of the D-INITIATE and D-CAPABILITY services for indication and invocation of application and communication characteristics during an association.
+
+Using the D-INITIATE service, an initial set of characteristics must be indicated, which partially can be modified or invoked by using the D-CAPABILITY service. These characteristics are in effect up to the next subsequent D-CAPABILITY service invocation. A D-CAPABILITY service is used by either the initiator or the responder being subject to owning the data token to indicate or invoke the above characteristics.
+
+Attention is drawn to the fact that the concept of how to use the D-INITIATE and D-CAPABILITY services is different for the two modes defined for the DTAM bulk transfer.
+
+- a) Under the DTAM Transparent Mode, one set of application capabilities must be indicated in the D-INITIATE service. This set can be modified during the association. The parameters of the D-CAPABILITY service are mapped to the S-CAPABILITY-DATA service parameters. The invocation of specific characteristics, used in the following document, is achieved by using the S-ACTIVITY-START service element. The service parameters of the S-ACTIVITY-START request are derived from the “document profile” which is not directly transferred to the receiving side under the DTAM Transparent Mode. However, the document profile is generated at the receiving side from the service parameters of S-ACTIVITY-START indication.
+- b) Under the DTAM Normal Mode, several sets of application capabilities may be indicated (at least one set must be present) in the D-INITIATE service. There are no means to modify these parameters during the association.
+
+One specific set of application capabilities may be invoked by using the D-CAPABILITY service to indicate the specific characteristics of the document which will be subsequently transmitted.
+
+## 6.3 *Document bulk transfer*
+
+DTAM provides a function to transmit a document in bulk from one DTAM user to a peer under the communications environment defined by the DTAM association use and the DTAM capability functions.
+
+## 6.4 *Document unconfirmed manipulations*
+
+DTAM provides a function to partially modify a document seen by both users, by generating, revising or deleting structures (pages, blocks, etc.) of an existing document, or to create a new document by generating structure without any confirmation of the manipulation. Five services are associated with document manipulation:
+
+- a) the unconfirmed create operation service is used by both sides to add the constituents of ODA and Operational Structure to an existing document or to create constituents of ODA and Operational Structure;
+- b) the unconfirmed delete operation service is used by both sides to delete the constituents of ODA and Operational Structure of an existing document;
+- c) the unconfirmed modify operation service is used by both sides to modify the attributes of the constituents of ODA and Operational Structure of an existing document;
+- d) the unconfirmed call operation service is used by both sides to request to address or to read an object of the Operational Structure which contains a sequence of the DTAM protocol data units. These protocol data units are applicable to the existing document;
+- e) the unconfirmed rebuild operation service is for further study.
+
+## 6.5 *Document confirmed manipulations (for further study)*
+
+DTAM provides a function to partially modify a document seen by both users, by generating, revising or deleting structure of an existing document or to create a new document by generating structure with a confirmation of the manipulation.
+
+## 6.6 *Typed data transmission*
+
+DTAM optionally provides the function of typed data transmission which is independent of the data token control.
+
+## 6.7 *Token control*
+
+Within DTAM, the right to transfer and manipulate documents is controlled in the following way:
+
+- the control of document transfer is associated with document bulk transfer;
+- the data token is associated with document manipulation.
+
+Token control provides services for exchanging the control of document transfer and for exchanging the data token.
+
+## 6.8 *Exception report*
+
+DTAM optionally provides two exception reporting functions for exceptional error control during the DTAM communication:
+
+- provider exception report (for further study);
+- user exception report (for further study).
+
+## 6.9 *Document selection control (for further study)*
+
+Four services are associated with document selection control:
+
+- a) the document selection service is used by the initiator to select an existing document and to bind the specified document to the DTAM application-association;
+
+- b) the document deselection service is used by the initiator to release the binding between the DTAM application-association and the specified document;
+- c) the document creation service is used by the initiator to create a specified document and to select the newly created document;
+- d) the document deletion service is used by the initiator to release an existing selection in such a way that the previously selected document ceases to exist.
+
+## 6.10 *Document management* (for further study)
+
+Two services are associated with document management:
+
+- a) the read attributes service is used by the initiator to interrogate the document attributes of the selected document;
+- b) the change attributes service is used by the initiator to modify the document attributes of the selected document.
+
+## 6.11 *Document open control* (for further study)
+
+Two services are associated with document open control:
+
+- a) the document open service is used by the initiator to establish the presentation context and the concurrency and commitment controls for data transfer;
+- b) the document close service is used by the initiator to release the context established by the document open service.
+
+## 6.12 *Grouping control* (for further study)
+
+Two services are associated with grouping control:
+
+- a) the beginning of grouping service is used by the initiator to indicate the start of a set of grouped primitives which are to be processed and responded to as a group;
+- b) the end of grouping service is used by the initiator to indicate the end of a set of grouped primitives which are to be processed and responded to as a group.
+
+# 7 **Functional units**
+
+DTAM service classes in Recommendation T.431 and in functional units are logical groupings of related services defined in this Recommendation for the purpose of
+
+- negotiation of the DTAM-service-user's requirements during DTAM application-association establishment;
+- reference by other CCITT Recommendations.
+
+## 7.1 *Association use control functional unit*
+
+The DTAM provides the trigger for the establishment and use of the association. The association use control unit supports the basic DTAM services for unique discrimination of both application entities (AEs), selection of functional units, set of an initial DTAM capability, establishment, termination and abort of association use.
+
+## 7.2 *Capability functional unit*
+
+The DTAM context is the communication environment depending on the document architecture (ODA and Operational Structure) used for data transmission on an association. In addition to the initial DTAM context setting at the start of association use, a context management unit is optionally used to set a more detailed communication environment, such as optional application capabilities.
+
+## 7.3 *Data transmission functional units*
+
+The DTAM provides document transfer methods, such as bulk document transfer, document manipulation and typed data transmission. The data transmission unit consists of the following four units.
+
+### 7.3.1 *Document bulk transfer functional unit*
+
+The DTAM has a function to transmit the document in bulk to the other DTAM user under the communication environment defined at the start of the association use and/or the capability control. The documents represented by the Document Interchange Format defined in Recommendations T.415 and T.441 are transmitted using the document bulk transfer unit. Other types of data may be transferred by using the transfer option defined for the DTAM bulk transfer.
+
+*Note* – The detailed definition of Recommendation T.441 (Interchange Format of Operational Structure) depends on the ongoing work on Operational Structure.
+
+### 7.3.2 *Document unconfirmed manipulation functional unit*
+
+DTAM provides a function to partially modify a document by generating, revising or deleting structures of an existing document or to create a new document. The DTAM user uses a document manipulation unit to manipulate structures of an existing document or to create a new document.
+
+### 7.3.3 *Document confirmed manipulation functional unit*
+
+Use of this functional unit is for further study.
+
+### 7.3.4 *Typed data transmission functional unit*
+
+The DTAM provides a function to pass these units directly to the DTAM user as typed data. User information (e.g. transmission interrupt) can be transported by typed transmission units without being subject to token control.
+
+## 7.4 *Exception report functional unit*
+
+The DTAM provides exception reporting services for exceptional conditions occurring in the DTAM user or DTAM-service-provider.
+
+## 7.5 *Session management functional units*
+
+The DTAM manages dialogue control functions provided by the session layer, the following functional units being available for DTAM communication environment.
+
+### 7.5.1 *Token control functional unit*
+
+Transmission rights required for document transfer and document manipulations are controlled with the token control unit. This functional unit will be selected in the case of the half duplex communication mode.
+
+For the Document manipulation functional unit, only the "data token" is required in nature. However, the right to use the Document manipulation is handled as follows:
+
+- when the Document bulk transfer functional unit is selected in addition to the Document manipulation, D-CONTROL-GIVE service is used;
+- when only the Document manipulation functional unit is selected, D-TOKEN-GIVE service is used.
+
+## 7.6 *Other functional units*
+
+The DTAM will provide a document selection control, a document management, an open control and a grouping control. These DTAM functions are left for further study.
+
+# **8 Service overview**
+
+This Recommendation defines the following services for the management of document transfer and manipulation facilities:
+
+- a) D-INITIATE;
+- b) D-TERMINATE;
+- c) D-P-ABORT;
+- d) D-U-ABORT;
+- e) D-CAPABILITY;
+- f) D-TRANSFER;
+- g) D-TYPED-DATA;
+- h) D-CREATE;
+- i) D-DELETE;
+- j) D-MODIFY;
+- k) D-CALL;
+- l) D-REBUILD;
+- m) D-TOKEN-GIVE;
+- n) D-CONTROL-GIVE;
+- o) D-TOKEN-PLEASE;
+- p) D-U-EXCEPTION-REPORT; and
+- q) D-P-EXCEPTION-REPORT.
+
+## **8.1 D-INITIATE service**
+
+Enables a DTAM-service-user to request the establishment of a DTAM application-association with another AE.
+
+## **8.2 D-TERMINATE service**
+
+Enables the association initiating or responding DTAM-service-user to request the termination of the established application-association. It may do so only if it possesses the data token.
+
+## **8.3 D-P-ABORT service**
+
+Enables a DTAM-service-provider to abort the application-association.
+
+## **8.4 D-U-ABORT service**
+
+Enables a DTAM-service-user to abort the application- association.
+
+## **8.5 D-CAPABILITY service**
+
+Enables the DTAM service user to invoke or negotiate some applications and communication characteristics during the life-time of the association.
+
+## **8.6 D-TRANSFER service**
+
+Enables a DTAM-service-user that possesses the data token to request the bulk document transfer over an application-association.
+
+## **8.7 D-TYPED-DATA service**
+
+Enables a DTAM-service-user to request the data transmission without being subject to token control, which is different from the document transfer service.
+
+## 8.8 **D-CREATE, D-DELETE and D-MODIFY services**
+
+Enable a DTAM service user that possesses the data token to request the creation, deletion and modification of the architectural objects and content-portions of a document.
+
+## 8.9 **D-CALL service**
+
+Enables a DTAM-service-user that possesses the data token to request to address or to read an object of the Operational Structure which contains a sequence of DTAM protocol data units (with some restrictions, i.e. that only D-CREATE, D-DELETE and D-MODIFY can appear in this sequence). These protocol data units are applicable to the existing document.
+
+## 8.10 **D-REBUILD service** is for further study.
+
+## 8.11 **D-TOKEN-GIVE service**
+
+Enables a DTAM-service-user to relinquish the data token to its peer. It may do so only if it possesses the data token.
+
+## 8.12 **D-CONTROL-GIVE service**
+
+Enables a DTAM-service-user to relinquish all the tokens (control) to its peer. It may do so only if it possesses all the tokens.
+
+## 8.13 **D-TOKEN-PLEASE service**
+
+Enables a DTAM-service-user to request the data token. It may do so only if it does not already possess the data token. The data token is requested by either DTAM-service-user to allow the DTAM-service-user to transfer documents.
+
+## 8.14 **D-U-EXCEPTION-REPORT service**
+
+Provides an exception reporting service for exceptional conditions occurring in either DTAM-service-user. This service is for further study.
+
+## 8.15 **D-P-EXCEPTION-REPORT service**
+
+Provides an exception reporting service for exceptional conditions occurring in the DTAM-service-provider. This service is for further study.
+
+# 9 **Service definition**
+
+## 9.0 **DTAM service**
+
+Is a logical interface for data handling between the DTAM user and DTAM service provider. The DTAM services are listed in Table 1/T.432.
+
+## 9.1 *D-INITIATE service*
+
+The DTAM user notifies the DTAM-service-provider of the start of association use with the D-INITIATE service primitive. This service primitive includes parameter sets for
+
+- unique discrimination of both AEs;
+- selection of functional units for the DTAM service used; and
+- establishment of a common communication environment in both systems.
+
+The related service structure consists of four events, as illustrated in Figure 2/T.432.
+
+TABLE 1/T.432
+
+### **DTAM services summary**
+
+| Service                     | Type               |
+|-----------------------------|--------------------|
+| D-INITIATE                  | Confirmed          |
+| D-TERMINATE                 | Confirmed          |
+| D-P-ABORT                   | Provider-initiated |
+| D-U-ABORT                   | Unconfirmed        |
+| D-CAPABILITY                | Confirmed          |
+| D-TRANSFER                  | Provider-confirmed |
+| D-TYPED-DATA                | Unconfirmed        |
+| D-CREATE                    | Unconfirmed        |
+| D-DELETE                    | Unconfirmed        |
+| D-MODIFY                    | Unconfirmed        |
+| D-CALL                      | Unconfirmed        |
+| D-REBUILD (Note)            | Unconfirmed        |
+| D-TOKEN-GIVE                | Unconfirmed        |
+| D-CONTROL-GIVE              | Unconfirmed        |
+| D-TOKEN-PLEASE              | Unconfirmed        |
+| D-P-EXCEPTION-REPORT (Note) | Provider-initiated |
+| D-U-EXCEPTION-REPORT (Note) | Unconfirmed        |
+
+*Note* – D-REBUILD, D-P-EXCEPTION-REPORT and D-U-EXCEPTION-REPORT services are for further study.
+
+![Sequence diagram showing D-INITIATE service events between DTAM user and DTAM provider.](75f0cb39f1cd165dfe4a6aa6c4d9388d_img.jpg)
+
+```
+
+sequenceDiagram
+    participant User1 as DTAM user
+    participant Provider as DTAM provider
+    participant User2 as DTAM user
+
+    User1->>Provider: D-INITIATE request
+    Provider->>User2: D-INITIATE indication
+    User2-->>Provider: D-INITIATE response
+    Provider-->>User1: D-INITIATE confirm
+  
+```
+
+The diagram illustrates the sequence of events for the D-INITIATE service. It involves three entities: DTAM user (left), DTAM provider (middle), and DTAM user (right). The sequence is as follows: 1. A solid arrow labeled 'D-INITIATE request' points from the left DTAM user to the DTAM provider. 2. A solid arrow labeled 'D-INITIATE indication' points from the DTAM provider to the right DTAM user. 3. A solid arrow labeled 'D-INITIATE response' points from the right DTAM user back to the DTAM provider. 4. A solid arrow labeled 'D-INITIATE confirm' points from the DTAM provider back to the left DTAM user. Dotted lines connect the request to the indication and the response to the confirm, showing the logical flow across the provider.
+
+Sequence diagram showing D-INITIATE service events between DTAM user and DTAM provider.
+
+T0811720-93
+
+FIGURE 2/T.432
+
+### **D-INITIATE service events**
+
+### 9.1.1 D-INITIATE service parameters
+
+Table 2/T.432 lists the D-INITIATE service parameters.
+
+TABLE 2/T.432  
+D-INITIATE service parameters  
+(Note 1)
+
+| Parameter                                     | D-INITIATE request | D-INITIATE indication | D-INITIATE response | D-INITIATE confirm |
+|-----------------------------------------------|--------------------|-----------------------|---------------------|--------------------|
+| <i>Transparent Mode</i>                       | U                  |                       |                     |                    |
+| Telematic requirements                        | M                  | M(=)                  | C*                  | C(=)               |
+| Application capabilities                      | M                  | M(=)                  | C*                  | C(=)               |
+| • DTAM-QOS (Note 2)                           | U                  | C(=)                  | U                   | C(=)               |
+| • Account                                     | U                  | C(=)                  | U                   | C(=)               |
+| Service classes (Note 2)                      |                    |                       |                     |                    |
+| Result                                        |                    |                       | M                   | M(=)               |
+| • User information                            | U                  | C(=)                  | U                   | C(=)               |
+| • Application context name                    | A                  | A(=)                  | A                   | A(=)               |
+| • Calling AP title                            | A                  | A(=)                  |                     |                    |
+| • Calling AP invocation-identifier            | A                  | A(=)                  |                     |                    |
+| • Calling AE qualifier                        | A                  | A(=)                  |                     |                    |
+| • Calling AE invocation-identifier            | A                  | A(=)                  |                     |                    |
+| • Called AP title                             | A                  | A(=)                  |                     |                    |
+| • Called AP invocation-identifier             | A                  | A(=)                  |                     |                    |
+| • Called AE qualifier                         | A                  | A(=)                  |                     |                    |
+| • Called AE invocation-identifier             | A                  | A(=)                  |                     |                    |
+| • Responding AP title                         |                    |                       | A                   | A(=)               |
+| • Responding AP invocation-identifier         |                    |                       | A                   | A(=)               |
+| • Responding AE qualifier                     |                    |                       | A                   | A(=)               |
+| • Responding AE invocation-identifier         |                    |                       | A                   | A(=)               |
+| • Calling presentation address                | P                  | P(=)                  |                     |                    |
+| • Called presentation address                 | P                  | P(=)                  |                     |                    |
+| • Responding presentation address             |                    |                       | P                   | P(=)               |
+| • Presentation context definition list        | P                  | P(=)                  |                     |                    |
+| • Presentation context definition result list |                    |                       | P                   | P(=)               |
+| • Presentation requirements                   | P                  | P(=)                  | P                   | P(=)               |
+| • Initial assignment of token                 | P or R             | P(=) or R(=)          | P or R              | P(=) or R(=)       |
+| • Quality of service (Note 3)                 | P                  | P(=)                  | P                   | P(=)               |
+| • Result source                               |                    |                       |                     | A                  |
+
+\* This parameter is mandatory in case the responder returns the “accepted” result parameter to the proposed requirements.
+
+- This parameter does not apply to the Transparent Mode.
+
+*Note 1* – The meaning of the characters used in the table is given in § 4.
+
+*Note 2* – The use of this parameter is for further study.
+
+*Note 3* – When RTSE is used, this parameter is absent and is handled by RTSE.
+
+#### 9.1.1.1 *Transparent Mode*
+
+This non-mandatory parameter is used to indicate to the local DTAM-PM how the DTAM protocol is to be mapped onto the lower layers. Presence of this parameter indicates that the mapping is to be done onto the session service. Absence of this parameter indicates the DTAM Normal Mode.
+
+#### 9.1.1.2 *Telematic requirements*
+
+In this Recommendation, the following functional units are defined for DTAM:
+
+- kernel (association use control);
+- capability;
+- document bulk transfer;
+- typed data transmission;
+- document unconfirmed manipulation;
+- document confirmed manipulation;
+- token control;
+- exception report.
+
+Telematic requirements specify the DTAM functional units which should be used during an association. In this case, each DTAM user proposes use or non-use of each functional unit, except for the kernel functional unit, based on the DTAM user requirements. The functional unit is selected only if both the initiator and the responder propose to use the functional unit.
+
+#### 9.1.1.3 *Application capabilities*
+
+The requested application capabilities parameter indicates, for each direction of transmission, the receiving application capabilities of the requestor. Each DTAM user exchanges its own receiving application capabilities with a peer DTAM user through D-INITIATE service. Values of this parameter may be the reason for subsequent termination. The continued progress of the service is only guaranteed if the DTAM user acts as a sender of a document within the requested receiving capabilities by the peer DTAM user (receiver of document). This parameter is stated independently by each DTAM user as the maximum receiving capabilities when that user is the receiving side. There is no negotiation. The stated value from each DTAM user is maintained and considered by the corresponding user for use when it is the sending DTAM user. The values for each direction of document transfer are not necessarily the same.
+
+The application capabilities parameter consists of one or more sets of sub-parameters. Each set, if present, shall contain one Document Application Profile parameter and, optionally, a combination of the four other parameters described hereafter. For the transfer of other types of data, the file transfer capabilities should be indicated.
+
+##### 9.1.1.3.1 *ODA application capabilities*
+
+###### 9.1.1.3.1.1 *Document application profile*
+
+The parameter specifies the document application profile available to the sender of this parameter as the receiving capabilities. The value of this parameter is one of the capabilities to handle the document application profiles defined by the CCITT and/or ISO.
+
+*Note* – In CCITT applications, document application profiles are defined in the T.500-Series of Recommendations.
+
+###### 9.1.1.3.1.2 *Document architecture class*
+
+This parameter specifies the document architecture class available to the sender of this parameter as the receiving capabilities. The value of this parameter is:
+
+- formatted.
+
+*Note* – This parameter is only present in the Transparent Mode.
+
+###### 9.1.1.3.1.3 *Non-basic document characteristics*
+
+This parameter specifies the non-basic document characteristics available to the sender of this parameter as the receiving capabilities. The attributes and values that may be specified by this parameter are restricted to those that are permitted by the corresponding document application profile.
+
+The format of this parameter is as described in Recommendation T.414.
+
+###### 9.1.1.3.1.4 *Non-basic structural characteristics*
+
+This parameter specifies the non-basic structural characteristics available to the sender of this parameter as the receiving capabilities. The attributes and values that may be specified by this parameter are restricted to those that are permitted by the corresponding document application profile.
+
+The format of this parameter is as described in Recommendation T.414.
+
+###### 9.1.1.3.1.5 *Operational Application Profile*
+
+Detailed specification of Operational Application Profile is for further study.
+
+##### 9.1.1.3.2 *File transfer capabilities*
+
+###### 9.1.1.3.2.1 *BFT (binary file transfer) capabilities*
+
+This parameter indicates the capability to receive files encoded according to the specifications of Recommendation T.434.
+
+###### 9.1.1.3.2.2 *Transparent data capability*
+
+This parameter indicates that the sender is ready to accept (when acting as a receiver) data that are transferred completely transparently.
+
+#### 9.1.1.4 *DTAM-QOS*
+
+DTAM-QOS is left for further study.
+
+#### 9.1.1.5 *Account*
+
+The account parameter identifies the account to which costs incurred in the application-association which is being established are to be charged.
+
+*Note* – Further study will be required.
+
+#### 9.1.1.6 *Service classes*
+
+The use of this parameter is for further study.
+
+#### 9.1.1.7 *Result*
+
+If the DINQ APDU was rejected by the responding DTAM-PM (i.e. a D-INITIATE indication primitive was not issued to the responder), this field is supplied by the responding DTAM-PM, otherwise, this field is the Result parameter from the D-INITIATE response primitive. In either situation, it appears as the Result parameter on the D-INITIATE confirm primitive. This field can take one of the following symbolic values:
+
+- accepted;
+- rejected by responder (reason-not-specified);
+- rejected by responder (protocol Version-not-supported);
+- rejected by responder (DTAM-QOS-not-supported);
+- rejected by responder (application-context-name-not-supported);
+- rejected by responding DTAM-PM.
+
+#### 9.1.1.8 *User information*
+
+This is the User information associated with the initiation of application association.
+
+#### 9.1.1.9 *Application context name*
+
+This parameter is used as defined in Recommendation X.217. The initiator of the application-association shall propose one of the application-context-names for the specific application in the D-INITIATE request primitive.
+
+The responder shall either
+
+- accept the application-context proposed by the initiator and return the same value of this parameter in the D-INITIATE response primitive; or
+- return, in the D-INITIATE response primitive, a Result parameter with the value “rejected by responder (application-context-name-not-supported)” and a different application-context-name in the D-INITIATE response primitive.
+
+#### 9.1.1.10 *Presentation Context Definition List*
+
+The Presentation Context Definition List comprises a presentation-context-definition for each abstract-syntax included in the application-context, i.e. at least one for
+
+- ACSE, and
+- DTAM.
+
+In the case of document bulk transfer (normal mode), RTSE is used as specified in Recommendation X.218. Due to restrictions imposed by Recommendation X.218, the types of the RTSE APDUs and DTAM APDUs form one single named abstract syntax. This single named abstract syntax also includes the types of the application that make use of DTAM.
+
+A presentation-context definition comprises a presentation-context identifier and an abstract syntax name for each of the single named abstract syntaxes.
+
+#### 9.1.1.11 *Quality of service*
+
+When RTSE is used, this parameter is absent and is handled by RTSE.
+
+#### 9.1.1.12 *Other parameters*
+
+Parameters marked with an “R” in Table 2/T.432 are defined in Recommendation X.218.
+
+Parameters marked with an “A” in Table 2/T.432 are defined in Recommendation X.217.
+
+Parameters marked with a “P” in Table 2/T.432 are defined in Recommendation X.216.
+
+## 9.2 *D-TERMINATE service*
+
+The D-TERMINATE service is used by either the association-initiator or the association-responder to request the termination of an application-association. It may do so if it possesses the data token and this service is a confirmed service.
+
+The termination of the application-association is without loss of information in transit. This service cannot be rejected by the association-responding DTAM-service-user.
+
+The related service structure consists of four events, as illustrated in Figure 3/T.432.
+
+### 9.2.1 *D-TERMINATE service parameters*
+
+Table 3/T.432 lists the D-TERMINATE service parameters. These parameters are only present in the Normal Mode for use of the OSI lower layer service. In the case of a Transparent Mode, this service primitive has no parameters.
+
+#### 9.2.1.1 *Charging*
+
+The charging parameter conveys information on the costs attributed to the account during the DTAM application-association which is being released. The use of this parameter is for further study.
+
+#### 9.2.1.2 User Information
+
+This is the User Information associated with the termination of application-association.
+
+![Sequence diagram showing D-TERMINATE service events between DTAM user, DTAM provider, and DTAM user.](5445597cceefaca1ac89e710fe339325_img.jpg)
+
+```
+
+sequenceDiagram
+    participant DTAM_user1 as DTAM user
+    participant DTAM_provider as DTAM provider
+    participant DTAM_user2 as DTAM user
+
+    DTAM_user1->>DTAM_provider: D-TERMINATE request
+    DTAM_provider->>DTAM_user2: D-TERMINATE indication
+    DTAM_user2-->>DTAM_provider: D-TERMINATE response
+    DTAM_provider-->>DTAM_user1: D-TERMINATE confirm
+    
+```
+
+T0811730-93
+
+Sequence diagram showing D-TERMINATE service events between DTAM user, DTAM provider, and DTAM user.
+
+FIGURE 3/T.432
+
+**D-TERMINATE service events**
+
+TABLE 3/T.432
+
+**D-TERMINATE service parameters**
+
+| Parameter                                                                            | D-TERMINATE request | D-TERMINATE indication | D-TERMINATE response | D-TERMINATE confirm |
+|--------------------------------------------------------------------------------------|---------------------|------------------------|----------------------|---------------------|
+| <ul style="list-style-type: none"> <li>Charging</li> <li>User Information</li> </ul> | U                   | C(=)                   | C<br>U               | C<br>C(=)           |
+
+- This parameter does not apply to the Transparent Mode.
+
+*Note* – The meaning of the characters used in the table is given in § 4.
+
+## 9.3 D-P-ABORT service
+
+The D-P-ABORT service provides an indication to both of the DTAM users that the application-association cannot be maintained (e.g. because retransmission is not possible). If it is the sender, the DTAM provider first issues a negative D-TRANSFER confirm primitive for the document information not yet transferred. This service is applicable for Document manipulation as well as Bulk transfer. In the case of Bulk transfer, if it is the receiver, the DTAM provider deletes any partially received document information prior to issuing the D-P-ABORT indication. This service is a provider-initiated service.
+
+The related service structure consists of two events, as illustrated in Figure 4/T.432.
+
+![Sequence diagram for D-P-ABORT service events showing a DTAM provider sending a D-P-ABORT indication to two DTAM users.](5b8a756d9a71c35f17db8bcb90b438a3_img.jpg)
+
+```
+
+sequenceDiagram
+    participant DTAM_provider as DTAM provider
+    participant DTAM_user1 as DTAM user
+    participant DTAM_user2 as DTAM user
+    DTAM_provider->>DTAM_user1: D-P-ABORT indication
+    DTAM_provider->>DTAM_user2: D-P-ABORT indication
+  
+```
+
+T0811740-93
+
+Sequence diagram for D-P-ABORT service events showing a DTAM provider sending a D-P-ABORT indication to two DTAM users.
+
+FIGURE 4/T.432
+
+### **D-P-ABORT service events**
+
+### 9.3.1 *D-P-ABORT service parameters*
+
+The D-P-ABORT service has no parameters.
+
+## 9.4 *D-U-ABORT service*
+
+The D-U-ABORT service enables a DTAM user to abort the application-association. The abort may be requested by either DTAM user. This service is an unconfirmed service.
+
+The related service structure consists of two events, as illustrated in Figure 5/T.432.
+
+![Sequence diagram for D-U-ABORT service events showing a DTAM user sending a D-U-ABORT request to a DTAM provider, which then sends a D-U-ABORT indication to another DTAM user.](75e4b78ee25f885d73120e3066a5253e_img.jpg)
+
+```
+
+sequenceDiagram
+    participant DTAM_user1 as DTAM user
+    participant DTAM_provider as DTAM provider
+    participant DTAM_user2 as DTAM user
+    DTAM_user1->>DTAM_provider: D-U-ABORT request
+    DTAM_provider->>DTAM_user2: D-U-ABORT indication
+  
+```
+
+T0811750-93
+
+Sequence diagram for D-U-ABORT service events showing a DTAM user sending a D-U-ABORT request to a DTAM provider, which then sends a D-U-ABORT indication to another DTAM user.
+
+FIGURE 5/T.432
+
+### **D-U-ABORT service events**
+
+### 9.4.1 *D-U-ABORT service parameters*
+
+Table 4/T.432 lists the parameter of D-U-ABORT.
+
+TABLE 4/T.432
+
+**D-U-ABORT service parameters**
+
+| Parameter                                                        | D-U-ABORT request | D-U-ABORT indication |
+|------------------------------------------------------------------|-------------------|----------------------|
+| <ul style="list-style-type: none"><li>User Information</li></ul> | U                 | C(=)                 |
+
+- This parameter does not apply to the Transparent Mode.
+
+*Note* – The meaning of the characters used in the table is given in § 4.
+
+#### 9.4.1.1 *User Information*
+
+This is the User Information associated with the abort of application-association.
+
+## 9.5 *D-CAPABILITY service*
+
+This service should be used outside the document transmission procedure. The multiple use of the D-CAPABILITY service within a single association may be permitted.
+
+The related service structure consists of four events as illustrated in Figure 6/T.432.
+
+![Sequence diagram showing D-CAPABILITY service events between DTAM user and DTAM provider.](421fc75480c21e7ebb25756826652367_img.jpg)
+
+```
+sequenceDiagram
+    participant DTAM_user as DTAM user
+    participant DTAM_provider as DTAM provider
+    participant DTAM_user2 as DTAM user
+
+    DTAM_user->>DTAM_provider: D-CAPABILITY request
+    DTAM_provider->>DTAM_user2: D-CAPABILITY indication
+    DTAM_user2->>DTAM_provider: D-CAPABILITY response
+    DTAM_provider-->>DTAM_user: D-CAPABILITY confirm
+```
+
+The diagram illustrates the D-CAPABILITY service events. It shows three vertical lifelines: DTAM user (left), DTAM provider (middle), and DTAM user (right). The sequence of events is as follows: 1. A solid arrow labeled 'D-CAPABILITY request' points from the left DTAM user to the DTAM provider. 2. A solid arrow labeled 'D-CAPABILITY indication' points from the DTAM provider to the right DTAM user. 3. A solid arrow labeled 'D-CAPABILITY response' points from the right DTAM user to the DTAM provider. 4. A solid arrow labeled 'D-CAPABILITY confirm' points from the DTAM provider back to the left DTAM user. Dashed lines connect the messages between the provider and the right user, and between the provider and the left user, indicating a return path or continuation of the interaction.
+
+Sequence diagram showing D-CAPABILITY service events between DTAM user and DTAM provider.
+
+T0811760-93
+
+FIGURE 6/T.432
+
+**D-CAPABILITY service events**
+
+### 9.5.1 *D-CAPABILITY service parameters*
+
+Table 5/T.432 lists the D-CAPABILITY service parameters.
+
+TABLE 5/T.432
+
+**D-CAPABILITY service parameters**
+
+| Parameter CAPABILITY                 | D-CAPABILITY request | D-CAPABILITY indication | D-CAPABILITY response | D-CAPABILITY confirm |
+|--------------------------------------|----------------------|-------------------------|-----------------------|----------------------|
+| Application capabilities             |                      |                         |                       |                      |
+| ODA application capabilities         |                      |                         |                       |                      |
+| Document application profile         | U                    | C(=)                    | U                     | C(=)                 |
+| * Document architecture class        | U                    | C(=)                    | U                     | C(=)                 |
+| Non-basic structural characteristics | U                    | C(=)                    | U                     | C(=)                 |
+| Non-basic document characteristics   | U                    | C(=)                    | U                     | C(=)                 |
+| • Operational application profile    | U                    | C(=)                    | U                     | C(=)                 |
+| File transfer capabilities           |                      |                         |                       |                      |
+| • BFT capabilities                   | U                    | C(=)                    | U                     | C(=)                 |
+| • Transparent capability             | U                    | C(=)                    | U                     | C(=)                 |
+| • Capability result                  |                      |                         | M                     | M(=)                 |
+| • User information                   | U                    | C(=)                    | U                     | C(=)                 |
+
+- This parameter is absent in the Transparent Mode.
+
+- \* This parameter is only present in the Transparent Mode.
+
+*Note* – The meaning of the characters used in the table is given in § 4.
+
+#### 9.5.1.1 *Application capabilities*
+
+The application capabilities parameter requested by the requesting DTAM user (requestor: sender of documents or other data) indicates a list of receiving application capabilities that may be required at the responding DTAM user by the requesting DTAM user. Application capabilities consist of the following two groups of parameters.
+
+##### 9.5.1.1.1 *ODA application capabilities*
+
+###### 9.5.1.1.1.1 *Document application profile*
+
+The parameter specifies the document application profile that may be required at the responding DTAM user by the requesting DTAM user. The values of this parameter are any combination of the capabilities to handle the document application profiles defined by the CCITT and/or ISO.
+
+*Note* – In CCITT applications, document application profiles are defined in the T.500-Series of Recommendations.
+
+###### 9.5.1.1.1.2 *Document architecture class*
+
+This parameter specifies the document architecture classes that may be required at the responding DTAM user by the requesting DTAM user. This parameter is only present in the DTAM Transparent Mode. The value of this parameter is:
+
+- formatted.
+
+###### 9.5.1.1.1.3 *Non-basic document characteristics*
+
+This parameter specifies the non-basic document characteristics that may be required at the responding DTAM user by the requesting DTAM user. The attributes and values that may be specified by this parameter are restricted to those that are permitted by the corresponding document application profile.
+
+The format of this parameter is as described in Recommendation T.414.
+
+###### 9.5.1.1.1.4 *Non-basic structural characteristics*
+
+This parameter specifies the non-basic structural characteristics that may be required at the responding DTAM user by the requesting DTAM user. The attributes and values that may be specified by this parameter are restricted to those that are permitted by the corresponding document application profile.
+
+The format of this parameter is as described in Recommendation T.414.
+
+###### 9.5.1.1.1.5 *Operational application profile*
+
+Detailed specifications of operational application profile is for further study.
+
+##### 9.5.1.1.2 *File transfer capabilities*
+
+The file transfer capabilities consist of different options of how a file transfer is supported under DTAM Normal Mode.
+
+*Note* – File transfer capabilities under DTAM Transparent Mode will be handled as specified in the relevant terminal characteristics.
+
+###### 9.5.1.1.2.1 *BFT (binary file transfer) capabilities*
+
+This parameter invokes the following transfer of files encoded according to the specifications of Recommendation T.434.
+
+###### 9.5.1.1.2.2 *Transparent data capability*
+
+This parameter invokes the following transfer of completely transparent data.
+
+#### 9.5.1.2 *Capability result*
+
+This result parameter contains one of the following:
+
+- a) confirmation that all the requested capabilities are available at the DTAM responder;
+- b) a list of the requested capabilities that are available at the DTAM responder;
+- c) a complete list of non-basic receiving capabilities;
+- d) indication that no extended capabilities are available in the DTAM responder, or that none of the capabilities requested by the initiator are available.
+
+#### 9.5.1.3 *User Information*
+
+This parameter is the User Information associated with the capability.
+
+## 9.6 *D-TRANSFER service*
+
+The D-TRANSFER service supports the document bulk transfer which is used to convey the document which contains ODA and Operational Structure or to convey a file to the remote DTAM user. The requestor who requests the D-TRANSFER service must have the data token.
+
+In the DTAM Normal Mode the reliable transfer is performed by the use of RTSE.
+
+In the DTAM Transparent Mode, the DTAM-service-provider performs the reliable transfer of a document but, in case of a problem, it will interrupt the transfer and indicate to the user that the transfer has not been completed. The user will then have the responsibility to start a new transmission by using the D-TRANSFER request primitive with the appropriate parameters.
+
+The related service structure consists of three events, as illustrated in Figure 7/T.432.
+
+![Sequence diagram showing D-TRANSFER service events between two DTAM users and a DTAM provider. The left DTAM user sends a D-TRANSFER request to the DTAM provider. The DTAM provider then sends a D-TRANSFER indication to the right DTAM user. Finally, the right DTAM user sends a D-TRANSFER confirm back to the DTAM provider.](7133ccf78043568ca62ecbcd43628a4a_img.jpg)
+
+```
+
+sequenceDiagram
+    participant User1 as DTAM user
+    participant Provider as DTAM provider
+    participant User2 as DTAM user
+
+    User1->>Provider: D-TRANSFER request
+    Provider->>User2: D-TRANSFER indication
+    User2-->>Provider: D-TRANSFER confirm
+  
+```
+
+T0811770-93
+
+Sequence diagram showing D-TRANSFER service events between two DTAM users and a DTAM provider. The left DTAM user sends a D-TRANSFER request to the DTAM provider. The DTAM provider then sends a D-TRANSFER indication to the right DTAM user. Finally, the right DTAM user sends a D-TRANSFER confirm back to the DTAM provider.
+
+FIGURE 7/T.432
+
+### **D-TRANSFER service events**
+
+### 9.6.1 *D-TRANSFER service parameters*
+
+Table 6/T.432 lists the D-TRANSFER service parameters.
+
+TABLE 6/T.432
+
+#### **D-TRANSFER service parameters** (Note 1)
+
+| Parameter                        | D-TRANSFER request | D-TRANSFER indication | D-TRANSFER confirm |
+|----------------------------------|--------------------|-----------------------|--------------------|
+| Document Information             | M                  | C (Note 2)            |                    |
+| • Transfer Time                  | M                  |                       |                    |
+| * Document Information Type      | M                  | C                     | C(=)               |
+| * Document Reference Information | M                  | M                     | M                  |
+| * Synchronization Point          | C (Note 3)         | (Note 5)              | C (Note 4)         |
+| Result                           |                    |                       | M                  |
+| * Checkpoint Value               | M                  |                       | M                  |
+
+- This parameter does not apply to the Transparent Mode.
+
+- \* This parameter applies to the Transparent Mode only.
+
+*Note 1* – The meaning of the characters used in the table is given in § 4.
+
+*Note 2* – Mandatory in the case of successful D-TRANSFER procedure.
+
+*Note 3* – Mandatory when the Document Information Type has the value Transfer of a document from a synchronization point.
+
+*Note 4* – See § 9.6.1.5 iii).
+
+*Note 5* – Use of this parameter in D-TRANSFER indication is for further study.
+
+#### 9.6.1.1 *Document information*
+
+This consists of an ODA document or a file which may contain any other type of data. ODA documents consist of one or more “interchange data elements” of the types defined in Recommendations T.415, T.441 and T.541, in accordance with the document application profile and operational application profile that are in effect.
+
+When RTSE is used, a single ASN.1 data type is required by Recommendation X.218 to convey the document information within an ASN.1 external type.
+
+*Note* – In the case that ODA documents are transferred by use of RTSE (DTAM Normal Mode), the rules described in Recommendation T.415 § 5.1 apply, and the document information is encoded as an ASN.1 sequence of interchange data elements.
+
+#### 9.6.1.2 *Transfer time*
+
+This parameter defines the time period within which the DTAM-provider must successfully transfer the Document information to the other DTAM-user. This parameter is used only in the DTAM Normal Mode as mandatory parameter and has to be supplied by the requestor of the D-TRANSFER service. The absence of this parameter indicates that the established DTAM application-association is performed under the DTAM Transparent Mode.
+
+#### 9.6.1.3 *Document information type*
+
+This parameter is used only in the DTAM Transparent Mode. It may take different values depending on the primitive where it is used:
+
+- a) in a D-TRANSFER request it shall take one of the following values:
+  - i) “transfer of a document from its beginning”;
+  - ii) “transfer of a document from a synchronization point” when the parameter takes this latter value, the value of the corresponding synchronization point shall be given in the parameter “synchronization point” (see § 9.6.1.5).
+- b) in a D-TRANSFER indication of confirm, it shall take one of the following values:
+  - i) “transfer completed”;
+  - ii) “transfer not completed”; when this parameter takes this latter value, the value of the last positively acknowledged synchronization point is given in the parameter “synchronization point” (see § 9.6.1.5).
+
+*Note* – In a logical interface sense, it is assumed that, for retransmission of document, the complete document is submitted to DTAM Protocol Machine (PM) using the D-TRANSFER service. It is assumed that DTAM-PM locates the checkpoints in the same manner as in the first transmission.
+
+#### 9.6.1.4 *Document reference information*
+
+This parameter uniquely identifies a document in the D-TRANSFER service. The value of this parameter shall be assigned as decimal digits, preferably but not necessarily starting from 001. This value shall then sequentially be incremented by one for each successive document transmission. This parameter shall be assigned to all documents by the DTAM user sending the document.
+
+In order to uniquely identify the documents exchanged, it is recommended that the same value of this parameter should not appear within an application-association. This parameter is used only in the DTAM Transparent Mode.
+
+#### 9.6.1.5 *Synchronization point*
+
+This parameter has different significations depending on the service primitive:
+
+- i) in a D-TRANSFER-request it indicates the requested minor synchronization point number from which the initiator tries to retransmit. It is used together with the value “transfer of a document from a synchronization point” of the parameter Document Information Type;
+- ii) in a D-TRANSFER-indication it indicates the last positively confirmed minor synchronization point number (for further study);
+- iii) in a D-TRANSFER-confirm it indicates the last positively confirmed minor synchronization point number. It is used together with the value “transfer not completed” of the parameter Document Information Type. If no synchronization point was confirmed during the document transfer, this parameter may be absent.
+
+This parameter is used only in the DTAM Transparent Mode.
+
+#### 9.6.1.6 *Result*
+
+This parameter specifies the result of the transfer as follows:
+
+- Document-Information-transferred: positive confirm; the Document-Information has been transferred to, and secured by the receiving DTAM-provider (used for both DTAM modes);
+- Document-information-not-transferred: negative confirm; the Document-Information could not be transferred within the specified transfer time (used for DTAM Normal Mode);
+- Document-Information-not-completely-transferred: negative confirm; the Document-Information could not be completely transferred, remaining part of the document as indicated by the value of the parameter “document information type” (used for DTAM Transparent Mode). The indication of this parameter may have as a result to resume the transmission of the remaining part of the document from the requesting DTAM user;
+- Document-Information-continue-not-possible: negative confirm; this value is used when the document linking information is not available at the sending or receiving side (used for DTAM Transparent Mode). The indication of this parameter may have as a result to retry the transmission of the entire document again from the requesting DTAM user.
+
+This parameter has to be supplied by the DTAM-provider.
+
+#### 9.6.1.7 *Checkpoint value*
+
+Under the DTAM Transparent Mode the places to insert the checkpoints are related to a number of IDEs indicated by the DTAM user. A checkpoint should be set at the end of each segment and a segment should be composed of the number of integral IDE which is indicated by the user. Only the number of IDE of the last segment is equal or inferior to the indicated number.
+
+This parameter specifies the number of IDEs that compose one segment.
+
+*Note* – Some applications may not count IDEs of Document Profile and Document Root.
+
+## 9.7 *D-TYPED-DATA service*
+
+Typed data transmission is used independently of the data token and is issued from both DTAM users when required.
+
+The related service structure consists of two events, as illustrated in Figure 8/T.432.
+
+### 9.7.1 *D-TYPED-DATA service parameter*
+
+The parameters of D-TYPED-DATA are listed in Table 7/T.432.
+
+#### 9.7.1.1 *Typed-Data Information*
+
+Typed-Data Information is chosen from the following strings:
+
+- NumericString;
+- PrintableString;
+- TeletexString;
+- VideotexString;
+- VisibleString;
+- OctetString;
+- IA5String;
+- GraphicString.
+
+![Sequence diagram for D-TYPED-DATA service events showing a request from a DTAM user to a DTAM provider and an indication from the provider to another DTAM user.](8c348bf9c2c81b018017ae1d19506a9a_img.jpg)
+
+```
+
+sequenceDiagram
+    participant User1 as DTAM user
+    participant Provider as DTAM provider
+    participant User2 as DTAM user
+
+    User1->>Provider: D-TYPED-DATA request
+    Provider->>User2: D-TYPED-DATA indication
+  
+```
+
+T0811780-93
+
+Sequence diagram for D-TYPED-DATA service events showing a request from a DTAM user to a DTAM provider and an indication from the provider to another DTAM user.
+
+FIGURE 8/T.432
+
+### **D-TYPED-DATA service events**
+
+TABLE 7/T.432
+
+#### **D-TYPED-DATA service parameters**
+
+| Parameter              | D-TYPED-DATA request | D-TYPED-DATA indication |
+|------------------------|----------------------|-------------------------|
+| Typed-Data Information | M                    | M(=)                    |
+
+*Note* – The meaning of the characters used in the table is given in § 4.
+
+## 9.8 *D-UNCONFIRMED-CREATE service*
+
+The document create operation procedure is used by the requestor of document manipulation to add the constituents of ODA and/or Operational Structure to a document without any confirmation of the create manipulation.
+
+The related service structure consists of two events, as illustrated in Figure 9/T.432.
+
+![Sequence diagram for D-UNCONFIRMED-CREATE service events showing a request from a DTAM user to a DTAM provider and an indication from the provider to another DTAM user.](7a02de7ed198501f7a4f6ca37c3f28c5_img.jpg)
+
+```
+
+sequenceDiagram
+    participant User1 as DTAM user
+    participant Provider as DTAM provider
+    participant User2 as DTAM user
+
+    User1->>Provider: D-CREATE request
+    Provider->>User2: D-CREATE indication
+  
+```
+
+T0811790-93
+
+Sequence diagram for D-UNCONFIRMED-CREATE service events showing a request from a DTAM user to a DTAM provider and an indication from the provider to another DTAM user.
+
+FIGURE 9/T.432
+
+### **D-UNCONFIRMED-CREATE service events**
+
+### 9.8.1 *D-UNCONFIRMED-CREATE service parameters*
+
+Table 8/T.432 lists the D-CREATE service parameters.
+
+TABLE 8/T.432
+
+#### **D-UNCONFIRMED-CREATE service parameters**
+
+| Parameter          | D-CREATE request | D-CREATE indication |
+|--------------------|------------------|---------------------|
+| Create Information | M                | M(=)                |
+
+*Note* – The meaning of the characters used in the table is given in § 4.
+
+#### 9.8.1.1 *Create Information*
+
+This parameter consists of a sequence of sequences of Parent Object or Class Identifiers and Objects which are as defined in Recommendations T.412 and T.441.
+
+## 9.9 *D-UNCONFIRMED-DELETE service*
+
+The document delete operation procedure is used by the requestor of document manipulation to delete the constituents of ODA and/or Operational Structure of an existing document without any confirmation of the delete operation.
+
+The related service structure consists of two events, as illustrated in Figure 10/T.432.
+
+![Sequence diagram showing D-DELETE request and D-DELETE indication between DTAM user and DTAM provider.](1c29dadab94c3fa552d270434db09c81_img.jpg)
+
+```
+sequenceDiagram
+    participant User1 as DTAM user
+    participant Provider as DTAM provider
+    participant User2 as DTAM user
+    User1->>Provider: D-DELETE request
+    Provider-->>User2: D-DELETE indication
+```
+
+T0811800-93
+
+Sequence diagram showing D-DELETE request and D-DELETE indication between DTAM user and DTAM provider.
+
+FIGURE 10/T.432
+
+### **D-UNCONFIRMED-DELETE service events**
+
+### 9.9.1 *D-UNCONFIRMED-DELETE service parameters*
+
+Table 9/T.432 lists the D-DELETE service parameters.
+
+TABLE 9/T.432
+
+**D-UNCONFIRMED-DELETE service parameters**
+
+| Parameter          | D-DELETE request | D-DELETE indication |
+|--------------------|------------------|---------------------|
+| Delete Information | M                | M(=)                |
+
+*Note* – The meaning of the characters used in the table is given in § 4.
+
+#### 9.9.1.1 *Delete Information*
+
+This parameter consists of a sequence of Object or Class Identifiers, Content Portion Identifiers and Operational Information Identifiers which are as defined in Recommendations T.412 and T.441.
+
+## 9.10 *D-UNCONFIRMED-MODIFY service*
+
+The document modify operation procedure is used by the requestor of document manipulation to modify the attributes of constituents of ODA and/or Operational Structure of an existing document without any confirmation of the modify operation.
+
+The related service structure consists of two events, as illustrated in Figure 11/T.432.
+
+![Sequence diagram showing D-UNCONFIRMED-MODIFY service events between DTAM user and DTAM provider.](a7585024ebe2bba8ac0757150a12759a_img.jpg)
+
+```
+sequenceDiagram
+    participant User1 as DTAM user
+    participant Provider as DTAM provider
+    participant User2 as DTAM user
+    User1->>Provider: D-MODIFY request
+    Provider->>User2: D-MODIFY indication
+```
+
+The diagram illustrates the service events for D-UNCONFIRMED-MODIFY. It shows three vertical lifelines: 'DTAM user' on the left, 'DTAM provider' in the center, and 'DTAM user' on the right. A solid arrow labeled 'D-MODIFY request' points from the first 'DTAM user' lifeline to the 'DTAM provider' lifeline. A dashed arrow labeled 'D-MODIFY indication' points from the 'DTAM provider' lifeline to the second 'DTAM user' lifeline. Below the lifelines, the identifier 'T0811810-93' is present.
+
+Sequence diagram showing D-UNCONFIRMED-MODIFY service events between DTAM user and DTAM provider.
+
+FIGURE 11/T.432
+
+**D-UNCONFIRMED-MODIFY service events**
+
+### 9.10.1 *D-UNCONFIRMED-MODIFY service parameters*
+
+Table 10/T.432 lists the D-MODIFY service parameters.
+
+TABLE 10/T.432
+
+**D-UNCONFIRMED-MODIFY service parameters**
+
+| Parameter          | D-MODIFY request | D-MODIFY indication |
+|--------------------|------------------|---------------------|
+| Modify Information | M                | M(=)                |
+
+*Note* – The meaning of the characters used in the table is given in § 4.
+
+#### 9.10.1.1 *Modify Information*
+
+This parameter is a sequence of sequences of Current Object or Class Identifiers and Objects which are as defined in Recommendations T.412 and T.441.
+
+## 9.11 *D-UNCONFIRMED-CALL service*
+
+This procedure is used to address or to read an object of Operational Structure which contains a sequence of DTAM protocol data units (with some restrictions, i.e. that only D-CREATE, D-DELETE and D-MODIFY can appear in this sequence). These protocol data units are applicable to the existing document.
+
+The related service structure consists of two events, as illustrated in Figure 12/T.432.
+
+![Sequence diagram showing D-UNCONFIRMED-CALL service events between DTAM user, DTAM provider, and DTAM user.](ca5dc5fde2061d0ca2051ef7840fc842_img.jpg)
+
+```
+sequenceDiagram
+    participant DTAM_user1 as DTAM user
+    participant DTAM_provider as DTAM provider
+    participant DTAM_user2 as DTAM user
+    DTAM_user1->>DTAM_provider: D-CALL request
+    DTAM_provider-->>DTAM_user2: D-CALL indication
+```
+
+T0811820-93
+
+Sequence diagram showing D-UNCONFIRMED-CALL service events between DTAM user, DTAM provider, and DTAM user.
+
+FIGURE 12/T.432
+
+**D-UNCONFIRMED-CALL service events**
+
+### 9.11.1 *D-UNCONFIRMED-CALL service parameters*
+
+Table 11/T.432 lists the D-CALL service parameters.
+
+TABLE 11/T.432
+
+**D-UNCONFIRMED-CALL service parameters**
+
+| Parameter        | D-CALL request | D-CALL indication |
+|------------------|----------------|-------------------|
+| Call Information | M              | M(=)              |
+
+*Note* – The meaning of the characters used in the table is given in § 4.
+
+#### 9.11.1.1 *Call Information*
+
+This parameter is a sequence of choices of Current Object Identifiers which are defined in Recommendation T.441.
+
+## 9.12 *D-UNCONFIRMED-REBUILD service*
+
+This procedure is used to delete an object of ODA and/or the Operational Structure (and all the subordinates of this object, if any) and create an object immediately after this particular object, updating the attributes of the object with the values carried by the D-REBUILD operation.
+
+This service is for further study.
+
+## 9.13 *D-TOKEN-GIVE service*
+
+The token-give procedure is used by a sender (requestor) to give the data token to the receiver (responder), when the sender wants to give the right to manipulate documents.
+
+The requestor becomes the receiver and the responder becomes the sender.
+
+The related service structure consists of two events, as illustrated in Figure 13/T.432.
+
+![Sequence diagram for D-TOKEN-GIVE service events showing interactions between DTAM user, DTAM provider, and DTAM user.](a796a6e439fe5969697f79dc5e124acc_img.jpg)
+
+```
+sequenceDiagram
+    participant U1 as DTAM user
+    participant P as DTAM provider
+    participant U2 as DTAM user
+    U1->>P: D-TOKEN-GIVE request
+    P-->>U2: D-TOKEN-GIVE indication
+```
+
+The diagram illustrates the sequence of events for the D-TOKEN-GIVE service. It involves three lifelines: DTAM user (left), DTAM provider (middle), and DTAM user (right). The first event is a solid arrow labeled "D-TOKEN-GIVE request" from the left DTAM user to the DTAM provider. The second event is a dashed arrow labeled "D-TOKEN-GIVE indication" from the DTAM provider to the right DTAM user. The identifier "T0811830-93" is located below the lifelines.
+
+Sequence diagram for D-TOKEN-GIVE service events showing interactions between DTAM user, DTAM provider, and DTAM user.
+
+FIGURE 13/T.432
+
+**D-TOKEN-GIVE service events**
+
+### 9.13.1 *D-TOKEN-GIVE service parameters*
+
+D-TOKEN-GIVE service has no parameters.
+
+## 9.14 *D-CONTROL-GIVE service*
+
+The control-give procedure is used by a sender (requestor) to give all the tokens to the receiver (responder). This service can only be requested when the Document bulk transfer functional unit has been selected and the requestor owns all the tokens.
+
+The requestor becomes the receiver and the responder becomes the sender.
+
+The related service structure consists of two events, as illustrated in Figure 14/T.432.
+
+![Sequence diagram for D-CONTROL-GIVE service events showing a request from a DTAM user to a DTAM provider and an indication from the provider to another DTAM user.](dbbc0baac7341cda76cc4f8355dce23f_img.jpg)
+
+```
+sequenceDiagram
+    participant User1 as DTAM user
+    participant Provider as DTAM provider
+    participant User2 as DTAM user
+    User1->>Provider: D-CONTROL-GIVE request
+    Provider->>User2: D-CONTROL-GIVE indication
+```
+
+T0811840-93
+
+Sequence diagram for D-CONTROL-GIVE service events showing a request from a DTAM user to a DTAM provider and an indication from the provider to another DTAM user.
+
+FIGURE 14/T.432
+
+### **D-CONTROL-GIVE service events**
+
+### 9.14.1 *D-CONTROL-GIVE service parameters*
+
+D-CONTROL-GIVE service has no parameters.
+
+## 9.15 *D-TOKEN-PLEASE service*
+
+The token-please procedure is used by a receiver (requestor) to request the data token from the sender (responder), when the receiver wants to request the right to transfer or manipulate documents.
+
+*Note* – The DTAM user, receiving a D-TOKEN-PLEASE indication, is not obliged to surrender the requested token.
+
+The related service structure consists of two events, as illustrated in Figure 15/T.432.
+
+![Sequence diagram showing D-TOKEN-PLEASE request and indication between DTAM user and DTAM provider.](399a5af4f606059626c92c92279d54b7_img.jpg)
+
+```
+
+sequenceDiagram
+    participant DTAM_user1 as DTAM user
+    participant DTAM_provider as DTAM provider
+    participant DTAM_user2 as DTAM user
+
+    DTAM_user1->>DTAM_provider: D-TOKEN-PLEASE request
+    DTAM_provider->>DTAM_user2: D-TOKEN-PLEASE indication
+    
+```
+
+T0811850-93
+
+Sequence diagram showing D-TOKEN-PLEASE request and indication between DTAM user and DTAM provider.
+
+FIGURE 15/T.432
+
+### **D-TOKEN-PLEASE service events**
+
+### 9.15.1 *D-TOKEN-PLEASE service parameters*
+
+Table 12/T.432 lists the D-TOKEN-PLEASE service parameters.
+
+TABLE 12/T.432
+
+#### **D-TOKEN-PLEASE service parameters**
+
+| Parameter       | D-TOKEN-PLEASE request | D-TOKEN-PLEASE indication |
+|-----------------|------------------------|---------------------------|
+| Tokens Priority | U                      | C(=)                      |
+
+*Note* – The meaning of the characters used in the table is given in § 4.
+
+#### 9.15.1.1 *Tokens Priority*
+
+This parameter defines the priority of the action, governed by the data token, that the requestor of the D-TOKEN-PLEASE service wishes to carry out. A priority is assigned to each DTAM user action. The supplied value of this parameter reflects the highest priority APDU awaiting transfer. Priority zero is the highest priority, and is reserved for the action of releasing the association by the initiator. Priority one shall be assigned to high priority documents. Priority two shall be assigned to normal priority documents. Priority three shall be assigned to low priority documents. This parameter has to be supplied by the requestor of the D-TOKEN-PLEASE service.
+
+The use of this parameter is mandatory, when RTSE is used (Bulk Transfer Normal Mode).
+
+*Note* – In the case of DTAM Transparent Mode, this parameter shall not be used.
+
+## 9.16 *D-P-EXCEPTION-REPORT service*
+
+The provider-exception reporting service permits DTAM users to be notified of unanticipated situations not covered by other services. Details are for further study.
+
+## 9.17 *D-U-EXCEPTION-REPORT service*
+
+The user-exception reporting service permits a DTAM user to report an exception condition.
+
+The detailed definition of this service is for further study.
\ No newline at end of file
diff --git a/marked/T/T-REC-T.433-199209-I_PDF-E/15de63f0b5df62e6ab9164f2a72e2e33_img.jpg b/marked/T/T-REC-T.433-199209-I_PDF-E/15de63f0b5df62e6ab9164f2a72e2e33_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..485bd67758b08c2e69f7f5df302210690d449e44
--- /dev/null
+++ b/marked/T/T-REC-T.433-199209-I_PDF-E/15de63f0b5df62e6ab9164f2a72e2e33_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:0e46b3b770ee2b59dedf81fa25cbacab60cc7992dd3f2f9ebc9daa73f768b8ce
+size 106352
diff --git a/marked/T/T-REC-T.433-199209-I_PDF-E/1b23b78336d8bd286c653cbdb38428dd_img.jpg b/marked/T/T-REC-T.433-199209-I_PDF-E/1b23b78336d8bd286c653cbdb38428dd_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..7dbd7f65a5f9b748954c7dd489da9ac44e365581
--- /dev/null
+++ b/marked/T/T-REC-T.433-199209-I_PDF-E/1b23b78336d8bd286c653cbdb38428dd_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:426a3c34f0bcba7b59fab70e63ef0274cfa24e8dae6c0e85481074dd03b2d778
+size 111747
diff --git a/marked/T/T-REC-T.433-199209-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/T/T-REC-T.433-199209-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..426fc8d504d132fbe86ca0b8f03f6e156ed2165f
--- /dev/null
+++ b/marked/T/T-REC-T.433-199209-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:01de97678926fe9ac4560d2561112d323d031b820afa2708e49c79dd6bd8dc4a
+size 8322
diff --git a/marked/T/T-REC-T.433-199209-I_PDF-E/3121ebddccf183ca63bb9781be440a7e_img.jpg b/marked/T/T-REC-T.433-199209-I_PDF-E/3121ebddccf183ca63bb9781be440a7e_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..3b9066a89a7ee685ff5715e1e86dc8cf09f56da6
--- /dev/null
+++ b/marked/T/T-REC-T.433-199209-I_PDF-E/3121ebddccf183ca63bb9781be440a7e_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:3e4a86def5d58aefc5b96fee56564f0453b016b9db4264af0d6f88a344099f64
+size 38563
diff --git a/marked/T/T-REC-T.433-199209-I_PDF-E/6ed175c791b5e156d9c98a8dbcc3318c_img.jpg b/marked/T/T-REC-T.433-199209-I_PDF-E/6ed175c791b5e156d9c98a8dbcc3318c_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..fce4842073d1b3d152d8f057449b7fbc9d6c8c24
--- /dev/null
+++ b/marked/T/T-REC-T.433-199209-I_PDF-E/6ed175c791b5e156d9c98a8dbcc3318c_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:6928aa1daa457f1b3d4c79a244d108a1776abe28d81aa5bf665e2e5feba2f98e
+size 6069
diff --git a/marked/T/T-REC-T.433-199209-I_PDF-E/74b540f71bcf10a8a66b2f01ea8c08ec_img.jpg b/marked/T/T-REC-T.433-199209-I_PDF-E/74b540f71bcf10a8a66b2f01ea8c08ec_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..fbdd72d36eb135b18341d42cab5a2142f0e0bf28
--- /dev/null
+++ b/marked/T/T-REC-T.433-199209-I_PDF-E/74b540f71bcf10a8a66b2f01ea8c08ec_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:11e9fb005d7573e24246ece4204261ff566a6ef713a0a8533fa3c1f7ec62df69
+size 110322
diff --git a/marked/T/T-REC-T.433-199209-I_PDF-E/c494cd874a082a97b50b3c4d3938f467_img.jpg b/marked/T/T-REC-T.433-199209-I_PDF-E/c494cd874a082a97b50b3c4d3938f467_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..885df1a117f03d0e99850aa77468aa60cd04d492
--- /dev/null
+++ b/marked/T/T-REC-T.433-199209-I_PDF-E/c494cd874a082a97b50b3c4d3938f467_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:09f59430f4d6536297d71331511f7b82a98d129ab8bbbc98f089ab946633bf31
+size 135643
diff --git a/marked/T/T-REC-T.435-199508-I_PDF-E/raw.md b/marked/T/T-REC-T.435-199508-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..8d19519217476e3795e821568f1b5ba9d97a80f2
--- /dev/null
+++ b/marked/T/T-REC-T.435-199508-I_PDF-E/raw.md
@@ -0,0 +1,3609 @@
+
+
+![ITU logo: a globe with the letters ITU inside, crossed by a lightning bolt.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg)
+
+ITU logo: a globe with the letters ITU inside, crossed by a lightning bolt.
+
+INTERNATIONAL TELECOMMUNICATION UNION
+
+# ITU-T
+
+TELECOMMUNICATION  
+STANDARDIZATION SECTOR  
+OF ITU
+
+## T.435
+
+(08/95)
+
+# TERMINALS FOR TELEMATIC SERVICES ---
+
+# DOCUMENT TRANSFER AND MANIPULATION (DTAM) – SERVICES AND PROTOCOLS – ABSTRACT SERVICE DEFINITION AND PROCEDURES FOR CONFIRMED DOCUMENT MANIPULATION
+
+## ITU-T Recommendation T.435
+
+(Previously “CCITT Recommendation”)
+
+---
+
+# FOREWORD
+
+The ITU-T (Telecommunication Standardization Sector) is a permanent organ of the International Telecommunication Union (ITU). The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis.
+
+The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics.
+
+The approval of Recommendations by the Members of the ITU-T is covered by the procedure laid down in WTSC Resolution No. 1 (Helsinki, March 1-12, 1993).
+
+ITU-T Recommendation T.435 was prepared by ITU-T Study Group 8 (1993-1996) and was approved under the WTSC Resolution No. 1 procedure on the 11th of August 1995.
+
+# --- NOTE
+
+In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+© ITU 1996
+
+All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU.
+
+# CONTENTS
+
+|                                                               | <i>Page</i> |
+|---------------------------------------------------------------|-------------|
+| 1 Scope .....                                                 | 1           |
+| 2 References .....                                            | 2           |
+| 3 Definitions .....                                           | 3           |
+| 4 Abbreviations .....                                         | 3           |
+| 5 Conventions .....                                           | 4           |
+| 6 Abstract models .....                                       | 4           |
+| 6.1 The DTAM-DM environment .....                             | 4           |
+| 6.1.1 The DTAM-DM client .....                                | 5           |
+| 6.1.2 The DTAM-DM server .....                                | 5           |
+| 6.1.3 The DTAM-DM port .....                                  | 5           |
+| 6.1.4 The DTAM-DM information model .....                     | 6           |
+| 6.1.4.1 Identification of manipulation objects .....          | 6           |
+| 6.1.4.2 Identification of complete documents .....            | 6           |
+| 6.1.4.3 Identification of document fragments .....            | 6           |
+| 6.1.4.4 Identification of document contents information ..... | 7           |
+| 6.2 The DTAM-DM/DTAM-TK combined environment .....            | 7           |
+| 6.2.1 The DTAM-DM/DTAM-TK client/server .....                 | 7           |
+| 6.2.2 The ports in the DTAM-DM/DTAM-TK environment .....      | 7           |
+| 6.2.2.1 The DTAM-DM-SYM port .....                            | 7           |
+| 6.2.2.2 The DTAM-TK port .....                                | 8           |
+| 6.2.3 The use of an application token .....                   | 8           |
+| 6.3 The DTAM-DM/DFR combined environment .....                | 8           |
+| 6.3.1 The DTAM-DM/DFR client .....                            | 10          |
+| 6.3.2 The DTAM-DM/DFR server .....                            | 10          |
+| 6.3.3 The ports in the DTAM-DM/DFR environment .....          | 10          |
+| 7 Overview of abstract services .....                         | 10          |
+| 7.1 Overview of DTAM-DM abstract services .....               | 10          |
+| 7.1.1 DM-DOCUMENT-OPEN abstract service .....                 | 11          |
+| 7.1.2 DM-DOCUMENT-SAVE abstract service .....                 | 11          |
+| 7.1.3 DM-DOCUMENT-DISCARD abstract service .....              | 11          |
+| 7.1.4 DM-DOCUMENT-CLOSE abstract service .....                | 11          |
+| 7.1.5 DM-DOCUMENT-LIST abstract service .....                 | 11          |
+| 7.1.6 DM-GET abstract service .....                           | 11          |
+| 7.1.7 DM-SEARCH abstract service .....                        | 11          |
+| 7.1.8 DM-CREATE abstract service .....                        | 11          |
+| 7.1.9 DM-DELETE abstract service .....                        | 11          |
+| 7.1.10 DM-MODIFY abstract service .....                       | 11          |
+| 7.1.11 DM-COPY abstract service .....                         | 11          |
+| 7.1.12 DM-MOVE abstract service .....                         | 12          |
+| 7.1.13 DM-REPLACE abstract service .....                      | 12          |
+| 7.1.14 DM-RESERVE abstract service .....                      | 12          |
+| 7.1.15 DM-UNRESERVE abstract service .....                    | 12          |
+| 7.1.16 DM-POINT abstract service .....                        | 12          |
+| 7.1.17 DM-MACRO-CALL abstract service .....                   | 12          |
+| 7.1.18 DM-GROUP-BEGIN abstract service .....                  | 12          |
+| 7.1.19 DM-GROUP-END abstract service .....                    | 12          |
+
+|         |                                                      |    |
+|---------|------------------------------------------------------|----|
+| 7.2     | Overview of DTAM-TK abstract services.....           | 12 |
+| 7.2.1   | TK-TOKEN-GIVE abstract service.....                  | 12 |
+| 7.2.2   | TK-TOKEN-PLEASE abstract service.....                | 12 |
+| 8       | Establishment of an application association.....     | 13 |
+| 8.1     | Abstract-bind and Abstract-unbind Parameters .....   | 13 |
+| 8.1.1   | ABSTRACT-BIND parameters .....                       | 13 |
+| 8.1.1.1 | Bind-argument parameters .....                       | 13 |
+| 8.1.1.2 | Bind-result parameters .....                         | 16 |
+| 8.1.1.3 | Bind-error parameters .....                          | 16 |
+| 8.1.2   | ABSTRACT-UNBIND parameters .....                     | 17 |
+| 8.2     | Use of the A-ABORT service .....                     | 17 |
+| 9       | Definition of abstract services.....                 | 17 |
+| 9.1     | Imported data types.....                             | 17 |
+| 9.2     | Defined data types common for abstract services..... | 18 |
+| 9.2.1   | DocumentIdentification .....                         | 18 |
+| 9.2.2   | ManipulationObject .....                             | 18 |
+| 9.2.3   | ObjectValue .....                                    | 18 |
+| 9.2.4   | Oda-Expression.....                                  | 18 |
+| 9.2.5   | ObjectPosition.....                                  | 19 |
+| 9.2.6   | ObjectContent .....                                  | 19 |
+| 9.2.7   | AssignedId .....                                     | 19 |
+| 9.2.8   | NonPermanentIdentifier.....                          | 19 |
+| 9.3     | Definition of DTAM-DM abstract services.....         | 19 |
+| 9.3.1   | DM-DOCUMENT-OPEN abstract service.....               | 20 |
+| 9.3.1.1 | Arguments.....                                       | 20 |
+| 9.3.1.2 | Result .....                                         | 20 |
+| 9.3.1.3 | Errors .....                                         | 20 |
+| 9.3.2   | DM-DOCUMENT-SAVE abstract service.....               | 20 |
+| 9.3.2.1 | Arguments.....                                       | 21 |
+| 9.3.2.2 | Result .....                                         | 21 |
+| 9.3.2.3 | Errors .....                                         | 21 |
+| 9.3.3   | DM-DOCUMENT-DISCARD abstract service.....            | 21 |
+| 9.3.3.1 | Arguments.....                                       | 21 |
+| 9.3.3.2 | Result .....                                         | 21 |
+| 9.3.3.3 | Errors .....                                         | 22 |
+| 9.3.4   | DM-DOCUMENT-CLOSE abstract service.....              | 22 |
+| 9.3.4.1 | Arguments.....                                       | 22 |
+| 9.3.4.2 | Result .....                                         | 22 |
+| 9.3.4.3 | Errors .....                                         | 22 |
+| 9.3.5   | DM-DOCUMENT-LIST abstract service.....               | 22 |
+| 9.3.5.1 | Arguments.....                                       | 23 |
+| 9.3.5.2 | Result .....                                         | 23 |
+| 9.3.5.3 | Errors .....                                         | 23 |
+| 9.3.6   | DM-GET abstract service .....                        | 23 |
+| 9.3.6.1 | Arguments.....                                       | 24 |
+| 9.3.6.2 | Result .....                                         | 24 |
+| 9.3.6.3 | Errors .....                                         | 24 |
+| 9.3.7   | DM-SEARCH abstract service .....                     | 24 |
+| 9.3.7.1 | Arguments.....                                       | 24 |
+| 9.3.7.2 | Result .....                                         | 24 |
+| 9.3.7.3 | Errors .....                                         | 25 |
+| 9.3.8   | DM-CREATE abstract service.....                      | 25 |
+| 9.3.8.1 | Arguments.....                                       | 25 |
+| 9.3.8.2 | Result .....                                         | 25 |
+| 9.3.8.3 | Errors .....                                         | 25 |
+
+|          | <i>Page</i>                                      |
+|----------|--------------------------------------------------|
+| 9.3.9    | DM-DELETE abstract service ..... 26              |
+| 9.3.9.1  | Arguments..... 26                                |
+| 9.3.9.2  | Result ..... 26                                  |
+| 9.3.9.3  | Errors ..... 26                                  |
+| 9.3.10   | DM-MODIFY abstract service ..... 26              |
+| 9.3.10.1 | Arguments..... 27                                |
+| 9.3.10.2 | Result ..... 27                                  |
+| 9.3.10.3 | Errors ..... 27                                  |
+| 9.3.11   | DM-COPY abstract service ..... 27                |
+| 9.3.11.1 | Arguments..... 28                                |
+| 9.3.11.2 | Result ..... 28                                  |
+| 9.3.11.3 | Errors ..... 28                                  |
+| 9.3.12   | DM-MOVE abstract service ..... 28                |
+| 9.3.12.1 | Arguments..... 29                                |
+| 9.3.12.2 | Result ..... 29                                  |
+| 9.3.12.3 | Errors ..... 29                                  |
+| 9.3.13   | DM-REPLACE abstract service ..... 29             |
+| 9.3.13.1 | Arguments..... 30                                |
+| 9.3.13.2 | Result ..... 30                                  |
+| 9.3.13.3 | Errors ..... 30                                  |
+| 9.3.14   | DM-RESERVE abstract service ..... 30             |
+| 9.3.14.1 | Arguments..... 31                                |
+| 9.3.14.2 | Result ..... 31                                  |
+| 9.3.14.3 | Errors ..... 31                                  |
+| 9.3.15   | DM-UNRESERVE abstract service..... 31            |
+| 9.3.15.1 | Arguments..... 32                                |
+| 9.3.15.2 | Result ..... 32                                  |
+| 9.3.15.3 | Errors ..... 32                                  |
+| 9.3.16   | DM-POINT abstract service ..... 32               |
+| 9.3.16.1 | Arguments..... 32                                |
+| 9.3.16.2 | Result ..... 32                                  |
+| 9.3.16.3 | Errors ..... 32                                  |
+| 9.3.17   | DM-MACRO-CALL abstract service..... 32           |
+| 9.3.17.1 | Arguments..... 33                                |
+| 9.3.17.2 | Result ..... 33                                  |
+| 9.3.17.3 | Errors ..... 33                                  |
+| 9.3.18   | DM-GROUP-BEGIN abstract service ..... 33         |
+| 9.3.18.1 | Arguments..... 33                                |
+| 9.3.18.2 | Result ..... 33                                  |
+| 9.3.18.3 | Errors ..... 33                                  |
+| 9.3.19   | DM-GROUP-END abstract service ..... 33           |
+| 9.3.19.1 | Arguments..... 34                                |
+| 9.3.19.2 | Result ..... 34                                  |
+| 9.3.19.3 | Errors ..... 34                                  |
+| 9.4      | Definitions of DTAM-DM abstract errors ..... 34  |
+| 9.4.1    | DM-access-error ..... 34                         |
+| 9.4.2    | DM-attribute-error ..... 35                      |
+| 9.4.3    | DM-update-error ..... 35                         |
+| 9.4.4    | DM-document-error ..... 36                       |
+| 9.4.5    | DM-fragment-error ..... 36                       |
+| 9.4.6    | DM-list-error..... 37                            |
+| 9.4.7    | DM-reservation-error..... 37                     |
+| 9.4.8    | DM-service-error ..... 37                        |
+| 9.4.9    | Error precedence ..... 38                        |
+| 9.5      | Definition of DTAM-TK abstract services ..... 38 |
+| 9.5.1    | TK-TOKEN-GIVE abstract service..... 38           |
+| 9.5.1.1  | Arguments..... 38                                |
+| 9.5.1.2  | Result ..... 38                                  |
+| 9.5.1.3  | Errors ..... 38                                  |
+
+|                                                                                                | <i>Page</i> |
+|------------------------------------------------------------------------------------------------|-------------|
+| 9.5.2 TK-TOKEN-PLEASE abstract service.....                                                    | 38          |
+| 9.5.2.1 Arguments.....                                                                         | 39          |
+| 9.5.2.2 Result .....                                                                           | 39          |
+| 9.5.2.3 Errors .....                                                                           | 39          |
+| 9.6 Definitions of DTAM-TK abstract errors .....                                               | 39          |
+| 9.6.1 TK-service-error .....                                                                   | 39          |
+| Annex A – Formal assignment of object identifiers .....                                        | 40          |
+| Annex B – Formal definition of DTAM-DM and DTAM-TK abstract services.....                      | 41          |
+| Appendix I – Basic procedures for the use of DTAM-DM abstract services .....                   | 54          |
+| I.1 DTAM association establishment .....                                                       | 54          |
+| I.2 Document open .....                                                                        | 54          |
+| I.3 Document manipulations .....                                                               | 54          |
+| I.4 Document save.....                                                                         | 54          |
+| I.5 Document discard .....                                                                     | 54          |
+| I.6 Document close .....                                                                       | 54          |
+| I.7 DTAM association termination.....                                                          | 54          |
+| Appendix II – Basic procedures for the combined use of DTAM-DM and DFR abstract services ..... | 56          |
+| II.1 DTAM-DM/DFR association establishment .....                                               | 56          |
+| II.2 Document filing and retrieval (use of DFR abstract services).....                         | 56          |
+| II.3 Document manipulation (use of DTAM-DM-abstract services) .....                            | 56          |
+| II.4 DTAM-DM/DFR association termination .....                                                 | 56          |
+
+# **SUMMARY**
+
+This Recommendation defines the abstract services for document remote access, presentation, editing, and transfer. It contains two new application service elements for interactive confirmed document manipulation, aligned with, and provided for, the integrated use with applications defined under the Distributed Office Application Model (DOAM). The two application service elements are the DTAM-TM and DTAM-TK.
+
+DTAM-DM provides the facilities to allow all type of remote document manipulation of full documents and document fragments. It is especially designed to be combined with the ODA Abstract Interface for Document manipulation (Recommendation T.413). If document storage and access is requested, provision is made in DTAM-DM that full use of the document filing and retrieval functions defined in ISO/IEC 10166 (DFR) can be made within the DTAM based association. DTAM-TK provides an application token function so that two or more users can communicate in conferences.
+
+
+
+# **DOCUMENT TRANSFER AND MANIPULATION (DTAM) – SERVICES AND PROTOCOLS – ABSTRACT SERVICE DEFINITION AND PROCEDURES FOR CONFIRMED DOCUMENT MANIPULATION**
+
+*(Geneva, 1995)*
+
+# **1 Scope**
+
+ITU-T (former CCITT) specified the seven-layer reference model of Open Systems Interconnection (OSI), Recommendation X.200. The overall objective of the OSI reference model is to define standards allowing systems to communicate.
+
+The OSI application layer is composed of the Application Service Elements (ASE) which are intended to provide specific services for applications.
+
+One of these application service elements is Document Transfer And Manipulation (DTAM). DTAM is designed for document handling, that is, transfer of documents and access and manipulation of document fragments between application entities within open telematic systems. DTAM is defined in the T.430-Series of Recommendations. Recommendation T.431 gives an introduction and describes general principles of DTAM. Recommendations T.432 and T.433 define the application service element for document bulk transfer and unconfirmed document manipulation.
+
+This Recommendation, together with the protocol specifications contained in Recommendation T.436, define two new application service elements for interactive confirmed document manipulation, aligned with (and provided for) the integrated use with applications defined under the Distributed Office Application Model (DOAM), ISO/IEC 10031.
+
+The two application service elements defined by this Recommendation are:
+
+- 1) DTAM-DM – The DTAM application service element for enhanced Document Manipulation; and
+- 2) DTAM-TK – The DTAM application service element for application ToKen exchange.
+
+The DTAM-DM abstract services provide facilities to allow remote operations on any kind of documents or document fragments. If the documents of interest are structured amount of information according to the Open Document Architecture (ODA), the document fragments represent the ODA constituents, the T.410 – and T.420 – Series of Recommendations. Documents of other types may provide other means to identify the document fragments uniquely. Documents and document fragments are considered to be manipulation objects within the scope of this Recommendation.
+
+DTAM-DM can be combined with the Document Filing and Retrieval (DFR) application service element, ISO/IEC 10166 for document access and manipulation applications. Both DFR and DTAM-DM are applications that allow remote operations on any kind of documents. While DTAM-DM is concerned with the manipulation of document fragments, the filing and retrieval of complete documents is in the scope of DFR. When there is a need to manipulate documents altogether as well as document fragments that are kept within a document store, the combined use of DTAM-DM and DFR abstract services is applied.
+
+The DTAM-TK application service element provides for the handling of an application token to structure a dialogue, if two or more users are involved in conference type of applications. DTAM-TK is intended to be used in conjunction with other application service elements, for example, together with DTAM-DM.
+
+The DTAM-DM and DTAM-TK abstract services are provided in conjunction with the Association Control Service Element (ACSE), Recommendation X.217, the Remote Operation Service Element (ROSE), Recommendation X.219, and the Presentation Service, Recommendation X.216.
+
+This Recommendation does not specify individual implementations or products, nor does it contain the implementation of entities or interfaces within a telematic system.
+
+# 2 References
+
+The following Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication the editions indicated were valid. All Recommendations and other references are subject to revision; all users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published.
+
+- ITU-T Recommendation T.411 (1993) ISO/IEC 8613-1:1994, *Information technology – Open Document Architecture (ODA) and interchange format – Introduction and general principles.*
+- ITU-T Recommendation T.412 (1993) ISO/IEC 8613-2:1995, *Information technology – Open Document Architecture (ODA) and interchange format – Document structures.*
+- ITU-T Recommendation T.413 (1994) ISO/IEC 8613-3 (1994), *Information technology Open Document Architecture (ODA) and interchange format – Abstract interface for the manipulation of ODA documents.*
+- ITU-T Recommendation T.414 (1993) ISO/IEC 8613-4:1994, *Information technology – Open Document Architecture (ODA) and interchange format – Document profile.*
+- ITU-T Recommendation T.415 (1993) ISO/IEC 8613-5:1994, *Information technology – Open Document Architecture (ODA) and interchange format – Open Document Interchange Format (ODIF).*
+- ITU-T Recommendation T.416 (1993) ISO/IEC 8613-6:1994, *Information technology – Open Document Architecture (ODA) and interchange format – Character content architecture.*
+- ITU-T Recommendation T.417 (1993) ISO/IEC 8613-7:1994, *Information technology – Open Document Architecture (ODA) and interchange formats – Raster graphics content architectures.*
+- ITU-T Recommendation T.418 (1993) ISO/IEC 8613-8:1994, *Information technology – Open Document Architecture (ODA) and interchange format – Geometric graphics content architecture.*
+- ITU-T Recommendation T.422 (1995) ISO/IEC 8613-12:1994, – *Open Document Architecture (ODA) and interchange format – Document pieces identification.*
+- CCITT Recommendation T.431 (1992), *Document Transfer And Manipulation (DTAM) – Services and protocols – Introduction and general principles.*
+- CCITT Recommendation T.432 (1992), *Document Transfer And Manipulation (DTAM) – Services and protocols – Service definition.*
+- CCITT Recommendation T.433 (1992), *Document Transfer And Manipulation (DTAM) – Services and protocols – Protocol specification.*
+- CCITT Recommendation T.434 (1992), *Binary file transfer format for the telematic services.*
+- ITU-T Recommendation T.436 (1995), *Document Transfer And Manipulation (DTAM) – Services and protocols – Protocol specifications for confirmed document manipulation.*
+- CCITT Recommendation X.200 (1988), *Reference model of Open Systems Interconnection for CCITT applications.*
+- CCITT Recommendation X.208 (1988), *Specification of Abstract Syntax Notation One (ASN.1).*
+- CCITT Recommendation X.209 (1988), *Specification of basic encoding rules for Abstract Syntax Notation One (ASN.1).*
+- CCITT Recommendation X.215 (1988), *Session service definition for Open Systems Interconnection for CCITT applications.*
+- CCITT Recommendation X.216 (1988), *Presentation service definition for Open Systems Interconnection for CCITT applications.*
+- CCITT Recommendation X.217 (1992), *Association control service definition for Open Systems Interconnection for CCITT applications.*
+- CCITT Recommendation X.219 (1988), *Remote operations: Model, notation and service definition.*
+
+- ISO/IEC 10021-3: 1990, *Information technology – Text communication – Message-Oriented Text Interchange Systems (MOTIS) – Part 3: Abstract service definition conventions.*
+- ISO/IEC 10031-1: 1991, *Information technology – Text and office systems – Distributed-office-applications Model – Part 1: General model.*
+- ISO/IEC 10166-1:1991, *Information technology – Text and office systems – Document Filing and Retrieval (DFR) – Part 1: Abstract service definition and procedures.*
+- ISO/IEC 10166-2: 1991, *Information technology – Text and Office systems – Document Filing and Retrieval (DFR) – Part 2: Protocol specification.*
+
+# 3 Definitions
+
+Definitions are given in Recommendation T.431.
+
+Additionally, the following definitions are used in this Recommendation:
+
+- 3.1 DTAM-DM client:** The object in the DTAM-DM environment which consumes the DTAM-DM abstract services provided by a DTAM-DM server.
+- 3.2 DTAM-DM server:** The object in the DTAM-DM environment which supplies the DTAM-DM abstract services.
+- 3.3 DTAM-DM port:** The connection between DTAM-DM client and DTAM-DM server which provides the abstract services, that is, the means to communicate in the DTAM-DM environment.
+- 3.4 DTAM-DM protocol:** The collection of rules which support the realization of the DTAM-DM port abstract services. This set of rules is normally given in a separate protocol specification.
+- 3.5 DTAM-DM environment:** A constellation of communicating objects connected by a DTAM-DM port. The communication procedure follows the rules determined by the DTAM-DM protocol.
+- 3.6 DTAM-TK client/server:** The object in the DTAM-TK environment which performs the DTAM-TK abstract services.
+- 3.7 DTAM-DM/DTAM-TK client/server:** The object in the DTAM-DM/DTAM-TK environment which performs the DTAM-DM and DTAM-TK abstract services.
+- 3.8 DTAM-TK port:** The connection between application entities which provides the DTAM-TK abstract services.
+- 3.9 DTAM-TK protocol:** The collection of rules which support the realization of the DTAM-TK port abstract services. This set of rules is normally given in a separate protocol specification.
+- 3.10 DTAM-DM/DTAM-TK environment:** A communication application which allows the combined usage of DTAM-DM and DTAM-TK abstract services.
+- 3.11 DTAM-DM/DFR client:** The consumer of abstract services supplied by a DTAM-DM/DFR server.
+- 3.12 DTAM-DM/DFR server:** The part of a DTAM-DM/DFR environment that supplies the combined usage of DTAM-DM and DFR abstract services.
+- 3.13 DTAM-DM/DFR environment:** A communication application which allows the combined usage of DTAM-DM and DFR abstract services.
+
+# 4 Abbreviations
+
+Abbreviations are defined in Recommendation T.431.
+
+Additionally, the following abbreviations are used in this Recommendation:
+
+|     |                               |
+|-----|-------------------------------|
+| DM  | Document Manipulation         |
+| TK  | ToKen exchange                |
+| DFR | Document Filing and Retrieval |
+| MO  | Manipulation Object           |
+| UPI | Unique-Permanent-Identifier   |
+
+# 5 Conventions
+
+This Recommendation specifies the DTAM-DM and DTAM-TK abstract services using the abstract syntax notation one, Recommendations X.208 and X.209, in conjunction with the abstract service definition conventions, ISO/IEC 10021.
+
+The applicability of services or service parameters is expressed by one of the following values:
+
+<Blank> Not applicable.
+
+M Mandatory. The item shall be present in any case.
+
+U User option. The presence of the item depends on the user's capabilities. The item may be absent.
+
+C Conditional. The presence of the item depends on conditions stated in this Recommendation.
+
+FS Further Study. Applicability is not clear at this time.
+
+NOTE – ASN.1 specifications in this Recommendation are written using “IMPLICIT TAGS” convention, which means systematic omission, at the time of ASN.1 encoding, of all unnecessary “nested” tags, especially those “recovered” by context-specific ones.
+
+# 6 Abstract models
+
+A client-server environment is an asymmetrical communication application which comprises two objects, the client and the server. Client and server are application entities which are connected by a port. The server is waiting to be contacted by the client so that the server can do something for the client.
+
+The port provides the abstract services, that is, the means to communicate in the environment. The collection of rules which support the realization of the port abstract services is normally given in a separate protocol specification.
+
+Using the notation of the client-server model, this Recommendation provides the following abstract communication environments:
+
+- DTAM-DM environment;
+- DTAM-DM/DTAM-TK combined environment;
+- DTAM-DM/DFR combined environment.
+
+The DTAM-DM environment provides abstract services for manipulations on inner parts of documents, the so called document fragments.
+
+The DTAM-DM/DTAM-TK combined environment provides all abstract services of the DTAM-DM environment, and additionally allows to exchange an application token between two objects, which are client and server at the same time. This combined environment may be used in conference communication applications.
+
+The DTAM-DM/DFR combined environment provides all abstract services of the DTAM-DM environment, and additionally allows to manage a document store. The abstract services provided by DFR allow to handle complete documents altogether instead of document fragments.
+
+These abstract communication environments are described in the following subclauses.
+
+The corresponding protocol specifications are given in Recommendation T.436.
+
+## 6.1 The DTAM-DM environment
+
+This subclause provides an abstract functional model of the DTAM-DM environment. The DTAM-DM environment provides for manipulations of document fragments.
+
+The DTAM-DM environment comprises two objects, the DTAM-DM client and the DTAM-DM server. Both objects are connected by the DTAM-DM port.
+
+Figure 1 shows the DTAM-DM environment.
+
+![Diagram of the DTAM-DM environment showing a DTAM-DM-client object connected to a DTAM-DM-server object via a DTAM-DM-port. The client is represented by an oval with a small square port on its bottom edge. The server is represented by an oval with a larger black square port on its top edge. A line connects the two ports, with the label 'DTAM-DM-port' placed above the line. Below the diagram is the identifier 'T0817970-94/d01'.](af7916c89a458fdab6c3f443217388ae_img.jpg)
+
+Diagram of the DTAM-DM environment showing a DTAM-DM-client object connected to a DTAM-DM-server object via a DTAM-DM-port. The client is represented by an oval with a small square port on its bottom edge. The server is represented by an oval with a larger black square port on its top edge. A line connects the two ports, with the label 'DTAM-DM-port' placed above the line. Below the diagram is the identifier 'T0817970-94/d01'.
+
+FIGURE 1/T.435  
+The DTAM-DM environment
+
+### 6.1.1 The DTAM-DM client
+
+The DTAM-DM client is modeled as an atomic object. The DTAM-DM client consumes the DTAM-DM port abstract services supplied by the DTAM-DM server.
+
+The formal definition of the DTAM-DM client object is:
+
+```
+dtam-dm-client    OBJECT
+                  PORTS { dtam-dm-port [ C ] }
+                  ::= id-ot-dtam-dm-client
+```
+
+### 6.1.2 The DTAM-DM server
+
+The DTAM-DM server is modeled as a separate object. It supplies the DTAM-DM port abstract services to the DTAM-DM client.
+
+The formal definition of the DTAM-DM server object is:
+
+```
+dtam-dm-server    OBJECT
+                  PORTS { dtam-dm-port [ S ] }
+                  ::= id-ot-dtam-dm-server
+```
+
+### 6.1.3 The DTAM-DM port
+
+The DTAM-DM port provides the means for the objects to communicate in the DTAM-DM environment.
+
+The DTAM-DM port is defined as follows:
+
+```
+dtam-dm-port      PORT
+                  CONSUMER INVOKES
+                  {
+                      DM-DOCUMENT-OPEN,
+                      DM-DOCUMENT-SAVE,
+                      DM-DOCUMENT-DISCARD,
+                      DM-DOCUMENT-CLOSE,
+                      DM-DOCUMENT-LIST,
+                      DM-GET,
+                      DM-SEARCH,
+                      DM-CREATE,
+                      DM-DELETE,
+                      DM-MODIFY,
+                      DM-COPY,
+                      DM-MOVE,
+```
+
+```
+
+DM-REPLACE,
+DM-RESERVE,
+DM-UNRESERVE,
+DM-POINT,
+DM-MACRO-CALL,
+DM-GROUP-BEGIN,
+DM-GROUP-END
+}
+SUPPLIER INVOKES
+{
+}
+::= id-pt-dtam-dm-port
+
+```
+
+### 6.1.4 The DTAM-DM information model
+
+A DTAM-DM server offers the DTAM-DM client operations on documents and on the environment which determines the capabilities how the documents can be manipulated. Documents are substructured objects to be considered as Manipulation Objects (MO) which may be for example:
+
+- ODA documents, substructured into several types of objects, classes, styles, contents, among others;
+- ODA document specific constraints defined in Document Application Profiles (DAPs) which allow to handle different semantic features, such as segments, paragraphs, footnotes, tables of contents, etc.;
+- SGML documents, substructured into regions determined by tags;
+- any other types of data in a structured form (including proprietary formats and covering the handling of multimedia data).
+
+The document manipulation environment consists of setting for the capabilities to manipulate a document (e.g. a profile of operations), and for the capabilities necessary to handle documents (e.g. specific profiles, character sets or non-basic characteristics).
+
+#### 6.1.4.1 Identification of manipulation objects
+
+DTAM document handling provides the operations to handle a previously identified document for different purposes, like manipulation or partial reading. The operations consist of three subsequently identified groups:
+
+- one for handling of the complete document;
+- one for handling of structured document fragments;
+- and one for handling the structured document content information.
+
+#### 6.1.4.2 Identification of complete documents
+
+Document identification takes place at the beginning and end of document manipulation. For identification of the relevant document for subsequent manipulation or to save, discard or close a manipulation, the document open, document save, document discard and document close abstract services are offered. A simple list abstract service is provided for application which have no support of the document filing and retrieval capabilities.
+
+More than one document may be opened at the same time. In this case, each of the operations for manipulation shall identify the document to which they apply.
+
+Documents that may be identified by the open, save, discard, list or close abstract services are each type of standardized documents or identifiable data.
+
+Identification mechanisms may be the UPI concept used in DFR, ISO/IEC 10166, among others.
+
+#### 6.1.4.3 Identification of document fragments
+
+Document fragments are identified during document manipulation operations. Therefore, the operations that identify the document fragments are the get-, search-, reserve-, unreserve-, create-, delete-, modify-, replace-, move-, macro-call- and point-operations.
+
+Document fragments of a structured document may be identified by the specific identification mechanism used in the relevant type of structured information, for example using the location model of ODA documents, Recommendation T.413.
+
+A second method for identification that is distinguished by a separated parameter is the identification of a document fragment via an expression that allow to derive which fragment(s) is (are) be manipulated.
+
+#### 6.1.4.4 Identification of document contents information
+
+The contents of documents may be identified by the search operation. The subsequent manipulation of unstructured parts of a document is for further study.
+
+## 6.2 The DTAM-DM/DTAM-TK combined environment
+
+For distributed document manipulation, the requirement is identified that an OSI system will often need to be the manipulating client for documents stored in other document servers, as well as being the document server for documents stored in its own OSI system. For this reason it was chosen to define the DTAM-DM/DTAM-TK abstract services as a symmetric service, allowing each entity to perform both the client and the server roles. Nevertheless there are dependencies which determine the role (client or server) of an entity for a specific moment.
+
+The DTAM-DM/DTAM-TK environment comprises one object, the DTAM-DM/DTAM-TK client/server. This object is connected to two ports, the DTAM-DM-SYM port and the DTAM-TK port. See Figure 2.
+
+![Diagram of the DTAM-DM/DTAM-TK combined environment showing two client/server objects connected by two ports.](bffdddb47fced140f8d17fdc2a29f592_img.jpg)
+
+The diagram illustrates the DTAM-DM/DTAM-TK combined environment. It consists of two identical ovals, each labeled 'DTAM-DM/DTAM-TK client/server'. Each oval has two small black squares on its right side, representing connection points. Two horizontal lines connect these squares between the two ovals. The top line is labeled 'DTAM-DM-SYM port' and the bottom line is labeled 'DTAM-TK port'. The identifier 'T0820010-94/d02' is located at the bottom right of the diagram.
+
+Diagram of the DTAM-DM/DTAM-TK combined environment showing two client/server objects connected by two ports.
+
+FIGURE 2/T.435
+
+### The DTAM-DM/DTAM-TK combined environment
+
+### 6.2.1 The DTAM-DM/DTAM-TK client/server
+
+The DTAM-DM/DTAM-TK client/server is modeled as an atomic object. The DTAM-DM/DTAM-TK client/server supports the abstract operations over the DTAM-DM-SYM port and the DTAM-TK port.
+
+The formal definition of the DTAM-DM/DTAM-TK client/server object is:
+
+```
+
+dtam-dm-tk-client-server    OBJECT
+                            PORTS { dtam-dm-sym-port, dtam-tk-port }
+                            ::= id-ot-dtam-dm-tk-client-server
+
+```
+
+### 6.2.2 The ports in the DTAM-DM/DTAM-TK environment
+
+The ports in the DTAM-DM/DTAM-TK environment are the DTAM-DM-SYM port and the DTAM-TK port. The DTAM-DM-SYM supports the same abstract operations as the DTAM-DM port, however it is a symmetric port. The DTAM-DM-SYM and the DTAM-TK port are defined in the following subclauses.
+
+#### 6.2.2.1 The DTAM-DM-SYM port
+
+The DTAM-DM-SYM port enables an DTAM-DM/DTAM-TK client/server to manipulate document fragments on other document stores and to perform manipulation operations on its own document store.
+
+The DTAM-DM-SYM port is defined as follows:
+
+```
+dtam-dm-sym-port      PORT
+  ABSTRACT OPERATIONS {
+    DM-DOCUMENT-OPEN,
+    DM-DOCUMENT-SAVE,
+    DM-DOCUMENT-DISCARD,
+    DM-DOCUMENT-CLOSE,
+    DM-DOCUMENT-LIST,
+    DM-GET,
+    DM-SEARCH,
+    DM-CREATE,
+    DM-DELETE,
+    DM-MODIFY,
+    DM-COPY,
+    DM-MOVE,
+    DM-REPLACE,
+    DM-RESERVE,
+    DM-UNRESERVE,
+    DM-POINT,
+    DM-MACRO-CALL,
+    DM-GROUP-BEGIN,
+    DM-GROUP-END }
+::= id-pt-dtam-dm-sym-port
+```
+
+#### **6.2.2.2 The DTAM-TK port**
+
+The DTAM-TK port enables the DTAM-DM/DTAM-TK client/server to exchange an application token which determines the role of the DTAM-DM/DTAM-TK client/server at any time. At one time, the DTAM-DM/DTAM-TK client/server can either act as a server or as a client. The use of an application token is specified in 6.2.3.
+
+The DTAM-TK port is defined as follows:
+
+```
+dtam-tk-port      PORT
+  ABSTRACT OPERATIONS {
+    TK-TOKEN-GIVE,
+    TK-TOKEN-PLEASE }
+::= id-pt-dtam-tk-port
+```
+
+### **6.2.3 The use of an application token**
+
+The exchange of an application token between client and server implies that the roles of the application entities in the environment will change. This is illustrated in Figure 3:
+
+User 1 and user 2 are two application entities which are able to operate as client or as server alternatively.
+
+In the start configuration it is assumed that user 1 possesses the application token. User 1 operates as client, while user 2 operates as server. When user 1 performs the DTAM-TK abstract service TK-TOKEN-GIVE, the application token is given to user 2. User 1 switches to the “server-state”, while the operation mode of user 2 is changed to “client-state”.
+
+Using the DTAM-TK abstract service TK-TOKEN-PLEASE, the actual server can request the application token exchange from the client.
+
+## **6.3 The DTAM-DM/DFR combined environment**
+
+This subclause provides an abstract functional model of the DTAM-DM/DFR combined environment. The DTAM-DM/DFR combined environment provides all abstract services of the DTAM-DM environment, and additionally allows to manage a document store.
+
+The DTAM-DM/DFR environment comprises two objects, the DTAM-DM/DFR client and the DTAM-DM/DFR server. Both objects are connected by two ports, the DTAM-DM port and the DFR port.
+
+Figure 4 shows the DTAM-DM/DFR combined environment.
+
+![Diagram a) Start configuration showing User 1 and User 2. User 1 has a Client and a Server. User 2 has a Client and a Server. A Token is shown at the top. Ports are connected between the Client of User 1 and the Server of User 2, and between the Server of User 1 and the Client of User 2.](8fbdfc3d17fb1dae7b2d8f5a287fa9fc_img.jpg)
+
+Diagram a) Start configuration shows two users, User 1 and User 2. Each user has a Client and a Server. A Token is located at the top. The connections are as follows:
+ 
+
+- Client of User 1 is connected to Server of User 2.
+- Server of User 1 is connected to Client of User 2.
+
+Diagram a) Start configuration showing User 1 and User 2. User 1 has a Client and a Server. User 2 has a Client and a Server. A Token is shown at the top. Ports are connected between the Client of User 1 and the Server of User 2, and between the Server of User 1 and the Client of User 2.
+
+a) Start configuration
+
+![Diagram b) End configuration showing the token exchange between User 1 and User 2. The Token is now at the top of User 2. The connections are the same as in diagram a).](2cde062fd82833415971a8bd1a2cafab_img.jpg)
+
+Diagram b) End configuration shows the same two users, User 1 and User 2. The Token has moved to the top of User 2. The connections remain the same:
+ 
+
+- Client of User 1 is connected to Server of User 2.
+- Server of User 1 is connected to Client of User 2.
+
+Diagram b) End configuration showing the token exchange between User 1 and User 2. The Token is now at the top of User 2. The connections are the same as in diagram a).
+
+b) End configuration
+
+T0820020-94/d03
+
+FIGURE 3/T.435  
+The use of an application token
+
+![Diagram showing the DTAM-DM/DFR combined environment. A DTAM-DM/DFR-client is connected to a DTAM-DM/DFR-server via DTAM-DM-ports and DFR-ports.](21ad58fee90f2be50708ff541d225507_img.jpg)
+
+Diagram showing the DTAM-DM/DFR combined environment. A DTAM-DM/DFR-client is connected to a DTAM-DM/DFR-server. The connection is established through DTAM-DM-ports and DFR-ports.
+
+Diagram showing the DTAM-DM/DFR combined environment. A DTAM-DM/DFR-client is connected to a DTAM-DM/DFR-server via DTAM-DM-ports and DFR-ports.
+
+T0817980-94/d04
+
+FIGURE 4/T.435  
+The DTAM-DM/DFR combined environment
+
+### 6.3.1 The DTAM-DM/DFR client
+
+The DTAM-DM/DFR client is modeled as an atomic object. The DTAM-DM/DFR client consumes the DTAM-DM port and the DFR port abstract services supplied by the DTAM-DM/DFR server.
+
+The formal definition of the DTAM-DM/DFR client object is:
+
+```
+dtam-dm-dfr-client  OBJECT
+                    PORTS { dtam-dm-port [ C ], dfr-port [ C ] }
+                    ::= id-ot-dtam-dm-dfr-client
+```
+
+### 6.3.2 The DTAM-DM/DFR server
+
+The DTAM-DM/DFR server is modeled as a separate object. It supplies the DTAM-DM port and the DFR port abstract services to the DTAM-DM/DFR client.
+
+The formal definition of the DTAM-DM/DFR server object is:
+
+```
+dtam-dm-dfr-server  OBJECT
+                    PORTS { dtam-dm-port [ S ], dfr-port [ S ] }
+                    ::= id-ot-dtam-dm-dfr-server
+```
+
+### 6.3.3 The ports in the DTAM-DM/DFR environment
+
+The ports in the DTAM-DM/DFR environment are the DTAM-DM port and the DFR port. The DTAM-DM port is already defined above. The DFR port is defined in ISO/IEC 10166 and imported by this Recommendation.
+
+NOTE – The use of the DM-Document-LIST abstract service is not allowed in the DTAM-DM/DFR environment. In this case the corresponding DFR abstract services shall be used.
+
+# 7 Overview of abstract services
+
+This clause provides an introduction to the DTAM-DM and DTAM-TK abstract services. The formal definition of the abstract services is given in Annex B “Formal definition of abstract services”.
+
+## 7.1 Overview of DTAM-DM abstract services
+
+This Recommendation defines the following DTAM-DM abstract services:
+
+- DM-DOCUMENT-OPEN;
+- DM-DOCUMENT-SAVE;
+- DM-DOCUMENT-DISCARD;
+- DM-DOCUMENT-CLOSE;
+- DM-DOCUMENT-LIST;
+- DM-GET;
+- DM-SEARCH;
+- DM-CREATE;
+- DM-DELETE;
+- DM-MODIFY;
+- DM-COPY;
+- DM-MOVE;
+- DM-REPLACE;
+- DM-RESERVE;
+- DM-UNRESERVE;
+- DM-POINT;
+- DM-MACRO-CALL;
+- DM-GROUP-BEGIN;
+- DM-GROUP-END.
+
+These DTAM-DM abstract services are introduced in the following subclauses.
+
+### **7.1.1 DM-DOCUMENT-OPEN abstract service**
+
+The document open abstract service is used by the DTAM-DM client to select and open documents prior to document manipulations. No inner manipulations can take place on documents which were not opened before. Several documents may be opened at the same time.
+
+### **7.1.2 DM-DOCUMENT-SAVE abstract service**
+
+The document save abstract service is used by the DTAM-DM client to save documents after document manipulations which were done since the use of the last DM-DOCUMENT-OPEN, DM-DOCUMENT-DISCARD or DM-DOCUMENT-SAVE abstract services.
+
+### **7.1.3 DM-DOCUMENT-DISCARD abstract service**
+
+The document discard abstract service is used by the DTAM-DM client to discard document manipulations which were done since the use of the last DM-DOCUMENT-SAVE, DM-DOCUMENT-OPEN or DM-DOCUMENT-DISCARD abstract service.
+
+### **7.1.4 DM-DOCUMENT-CLOSE abstract service**
+
+The document close abstract service is used by the DTAM-DM client to close and derelict documents after document manipulations. All document manipulations which were done since the use of the last DM-DOCUMENT-OPEN, DM-DOCUMENT-SAVE or DM-DOCUMENT-DISCARD abstract service are discarded. To save the document contents before the document will be closed, the DM-DOCUMENT-SAVE abstract service must be used.
+
+### **7.1.5 DM-DOCUMENT-LIST abstract service**
+
+The document list abstract service is used by the DTAM-DM client to request a list of document identifications from the DTAM-DM server that are in-line with the indicated criteria. The use of the document list service is restricted to applications that have limited filing and retrieval capabilities. For applications that support both, filing and retrieval as well as manipulation, the combined usage of DFR and DTAM-DM is recommended.
+
+### **7.1.6 DM-GET abstract service**
+
+The get abstract service is used by the DTAM-DM client to read document fragments.
+
+### **7.1.7 DM-SEARCH abstract service**
+
+The search abstract service is used by the DTAM-DM client to search for specified document fragments. The DTAM-DM client specifies search domains (e.g. to search only in the first chapter) and search criteria. The search abstract service may be used to identify document fragments for invocation of subsequent abstract operations like modify or create, among others.
+
+### **7.1.8 DM-CREATE abstract service**
+
+The create abstract service is used by the DTAM-DM client to add document fragments to an existing document. The create abstract service may carry the document fragment, including the values applicable to the created document fragment. The DTAM-DM client must specify the position of the additional document fragment inside the document.
+
+### **7.1.9 DM-DELETE abstract service**
+
+The delete abstract service is used by the DTAM-DM client to delete document fragments.
+
+### **7.1.10 DM-MODIFY abstract service**
+
+The modify abstract service is used by the DTAM-DM client to modify already existing document fragments. The modify abstract service assigns new values to attributes of the identified document fragment.
+
+### **7.1.11 DM-COPY abstract service**
+
+The copy abstract service is used by the DTAM-DM client to duplicate document fragments to another position of the same or a different document.
+
+### **7.1.12 DM-MOVE abstract service**
+
+The move abstract service is used by the DTAM-DM client to change the position of document fragments inside a document, or from one document to another.
+
+### **7.1.13 DM-REPLACE abstract service**
+
+The replace abstract service is used by the DTAM-DM client to replace document fragments. The replace abstract service effects the deletion of the identified document fragment and the replacement by the new document fragment.
+
+### **7.1.14 DM-RESERVE abstract service**
+
+The reserve abstract service is used by the DTAM-DM client to establish the reservation of the specified document fragment. The reserve abstract operation does not apply to ownership or access rights of document fragments (e.g. the access rights in the document profile of an ODA document).
+
+### **7.1.15 DM-UNRESERVE abstract service**
+
+The unreserve abstract service is used by a DTAM-DM client to release a previous reservation of a document fragment done by using the reserve abstract service.
+
+### **7.1.16 DM-POINT abstract service**
+
+The point abstract service is used by DTAM-DM clients in multi-user applications like joint-editing or joint-viewing.
+
+### **7.1.17 DM-MACRO-CALL abstract service**
+
+This is for further study.
+
+### **7.1.18 DM-GROUP-BEGIN abstract service**
+
+The group-begin abstract service is used by the DTAM-DM client to indicate the start of a set of DTAM-DM abstract services which are to be processed and responded to as a group.
+
+This is for further study.
+
+### **7.1.19 DM-GROUP-END abstract service**
+
+The group-end abstract service is used by the DTAM-DM client to indicate the end of a set of DTAM-DM abstract services which are to be processed and responded to as a group.
+
+This is for further study.
+
+## **7.2 Overview of DTAM-TK abstract services**
+
+This Recommendation defines the following DTAM-TK abstract services:
+
+- TK-TOKEN-GIVE;
+- TK-TOKEN-PLEASE.
+
+These DTAM-TK abstract services are introduced in the following subclauses.
+
+### **7.2.1 TK-TOKEN-GIVE abstract service**
+
+The token-give abstract service surrenders the application token from the current DTAM-TK client to the DTAM-TK server and changes the roles of the application entities in the communication process (from client to server and vice versa). The application token makes use of the ROSE services, Recommendation X.219, and hence has no relationship to communication tokens used in other OSI-layers, for example, the session tokens.
+
+### **7.2.2 TK-TOKEN-PLEASE abstract service**
+
+The token-please abstract service is used by the DTAM-TK server to request the application token from a DTAM-TK client, that is, a request changes the role of the application entities in the communication process.
+
+# 8 Establishment of an application association
+
+The DTAM-DM and DTAM-TK application service elements are used in conjunction with ACSE services and the formal notation of the abstract bind-operation and the unbind-operation. The specification of the abstract bind and unbind operation is specified in Recommendation X.407. The mapping of the bind-operation and unbind-operation on the ACSE services is described in Recommendation X.219.
+
+In the following explanations the terms “DTAM-DM client” and “DTAM-DM server” are used which have only a meaning in the DTAM-DM and DTAM-DM/DFR environment. In the DTAM-DM/DTAM-TK environment these terms must be interpreted as “requesting client/server” and “responding client/server” respectively. In the DTAM-DM/DFR environment these terms must be interpreted as “DTAM-DM/DFR client” and “DTAM-DM/DFR server” respectively.
+
+## 8.1 Abstract-bind and Abstract-unbind Parameters
+
+### 8.1.1 ABSTRACT-BIND parameters
+
+The DTAM-DMBind abstract operation binds the DTAM-DM port of the DTAM-DM client (consumer) to the DTAM-DM server (supplier). In the DTAM-DM/DTAM-TK environment, the DTAM-DMBind abstract operation binds the DTAM-DM-SYM and DTAM-TK ports of the DTAM-DM/DTAM-TK client/server. In the DTAM-DM/DFR environment, the DTAM-DMBind abstract operation binds the DTAM/DM and DFR ports of the DTAM-DM/DFR client (consumer) to the DTAM-DM/DFR server (supplier).
+
+**DTAM-DMBind ::= ABSTRACT-BIND**
+
+|                   |                                                                |
+|-------------------|----------------------------------------------------------------|
+| <b>TO</b>         | {dtam-dm-port[S], dfr-port[S], dtam-dm-sym-port, dtam-tk-port} |
+| <b>BIND</b>       |                                                                |
+| <b>ARGUMENT</b>   | <b>DtamDmBindArgument</b>                                      |
+| <b>RESULT</b>     | <b>DtamDmBindResult</b>                                        |
+| <b>BIND-ERROR</b> | <b>DtamDmBindError</b>                                         |
+
+#### 8.1.1.1 Bind-argument parameters
+
+The DtamDmBindArgument parameter allows to agree on the capabilities used during the association.
+
+**DtamDmBindArgument ::= [0] SEQUENCE {**
+
+|                                     |                                                                        |
+|-------------------------------------|------------------------------------------------------------------------|
+| <b>dtamProtocolVersion</b>          | <b>[0] BIT STRING</b><br>{ version-1 (0) } <b>DEFAULT</b> {version-1}, |
+| <b>dtamManipulationCapabilities</b> | <b>[1] ManipulationCapabilities,</b>                                   |
+| <b>odaApplicationCapabilities</b>   | <b>[2] SEQUENCE OF OdaApplicationCapabilities</b><br><b>OPTIONAL,</b>  |
+| <b>dfrCapablities</b>               | <b>[3] DfrCapabilities OPTIONAL,</b>                                   |
+| <b>bilateralInformation</b>         | <b>[4] SEQUENCE OF</b><br><b>BilateralInformation OPTIONAL,</b>        |
+| <b>applicationRequirements</b>      | <b>[5] ApplicationRequirements OPTIONAL }</b>                          |
+
+- a) **dtamProtocolVersion:** This parameter indicates the DTAM-DM protocol versions which the DTAM-DM client requests. It is a variable length bit string where each bit set to one indicates the version of the DTAM-DM protocol which is requested. Multiple bits may be set indicating the support of multiple versions. No trailing bits higher than the highest version of this Recommendation which the client supports are included. That is, the last bit of the string is set to one. When this parameter is absent, the default value “version-1” is applied.
+
+If the DTAM-DM server supports a requested protocol version, DTAM-DM Abstract-Bind continues normally. Otherwise, the DTAM-DM server will not accept the association with a corresponding error message (see 8.1.1.3).
+
+Version-1 is defined by Recommendation T.436.
+
+- b) **dtamManipulationCapabilities:** This parameter indicates the DTAM-DM capabilities the DTAM/DM client wants to use during the association. The capabilities are negotiated with the DTAM-DM server. If the DTAM-DM server can support these capabilities, the bind operation continues normally. If the DTAM-DM server cannot support these capabilities, the DTAM-DM server will not accept the association with a corresponding error message (see 8.1.1.3).
+
+It is possible to select a standardized DTAM-DM profile or to agree on known bilateral conventions. Alternatively, the manipulation level can be indicated.
+
+See Table 1 for an overview of the relationship between DTAM-DM abstract services and the possible values of manipulationLevelSelection hold in the ManipulationCapabilities parameter.
+
+**ManipulationCapabilities ::= CHOICE {**  
+     **profileSelection** [0] OBJECT IDENTIFIER,  
+     **manipulationLevelSelection** [1] ENUMERATED {  
+         **basicReadOnlyLevel** (0),  
+         **basicManipulationLevel** (1),  
+         **extendedLevel** (2) },  
+     **bilateralAgreement** [2] IMPLICIT OCTET STRING }
+
+- c) **odaApplicationCapabilities:** In the bind-operation, this parameter is optional and shall only be used in the conference type of applications, where each partner has symmetrical capabilities (consists of a client and a server). It specifies the document application profile and, optionally, two other parameters described hereafter as the receiving capabilities of the DTAM-DM/DTAM-TK client/server. The continued progress of the service is only guaranteed if the communication partner acts within the receiving capabilities of the DTAM-DM/DTAM-TK client/server.
+
+The NonBasicOdaDocumentCharacteristics specify the non-basic document characteristics available to the server as the receiving capabilities. The attributes and values that may be specified by this parameter are restricted to those that are permitted by the corresponding document application profile. The format of this parameter is described in Recommendation T.414.
+
+The NonBasicOdaStructuralCharacteristics specify the non-basic structural characteristics available to the server as the receiving capabilities. The attributes and values that may be specified by this parameter are restricted to those that are permitted by the corresponding document application profile. The format of this parameter is described in Recommendation T.414.
+
+**OdaApplicationCapabilities ::= SEQUENCE {**  
+     **odaDocumentApplicationProfile** [0] OBJECT IDENTIFIER,  
+     **nonBasicOdaDocumentCharacteristics** [1] Non-Basic-Doc-Characteristics  
+         OPTIONAL,  
+     **nonBasicOdaStructuralCharacteristics** [2] Non-Basic-Struc-Characteristics  
+         OPTIONAL }
+
+- d) **dfrCapabilities:** In the bind-operation, this parameter is optional and shall only be used in the DTAM-DM/DFR environment. This parameter indicates the DFR capabilities which the DTAM-DM/DFR client requests in the DTAM-DM/DFR environment. This is a DFR protocol version and, optionally, a DFR profile.
+
+The DFR protocol version is a variable length bit string where each bit set to one indicates the version of the DFR protocol which is requested. Multiple bits may be set indicating the support of multiple versions. No trailing bits higher than the highest version of this Recommendation which the client supports are included. That is, the last bit of the string is set to one.
+
+If the DTAM-DM/DFR server supports the requested DFR capabilities, DTAM-DM Abstract-Bind continues normally. Otherwise, the DTAM-DM/DFR server will not accept the association with a corresponding error message (see 8.1.1.3).
+
+**DfrCapabilities ::= SEQUENCE {**  
+     **dfrProtocolVersion** [0] DfrProtocolVersion DEFAULT {version-1},  
+     **dfrProfile** [1] OBJECT IDENTIFIER OPTIONAL }
+
+**DfrProtocolVersion ::= BIT STRING {**  
+     **version-1** (1),  
+     **version-2** (2) }
+
+- Version-1 is defined by ISO/IEC 10166-1:1991
+- Version-2 is defined by ISO/IEC 10166-1:1991 together with ISO/IEC 10166-1:1991/Amd 1.
+
+- e) **bilateralInformation:** This parameter includes bilateral information between the DTAM-DM client and the DTAM-DM server. Format of this bilateral information is as follows:
+
+**BilateralInformation ::= SEQUENCE {**  
+     **serverName** [0] ServerName,  
+     **information** [1] EXTERNAL }
+
+**ServerName ::= DistinguishedName**
+
+- f) **applicationRequirements:** This parameter indicates additional application requirements which are negotiated between the DTAM server and the client. The meaning of this parameter is application dependent. If the DTAM server can support these requirements, the bind operation continues normally. Otherwise, the DTAM server will not accept the association with a corresponding error message (see 8.1.1.3).
+
+**ApplicationRequirement ::= CHOICE {**
+
+**[0] OCTET STRING,**
+
+**[1] OBJECT IDENTIFIER }**
+
+TABLE 1/T.435
+
+##### **Relation between abstract services and the manipulationLevelSelection values**
+
+| DTAM-DM abstract services                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              | manipulationLevelSelection |                        |               |
+|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------|------------------------|---------------|
+|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        | basicReadOnlyLevel         | basicManipulationLevel | extendedLevel |
+| DM-DOCUMENT-OPEN (Note 1)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              | M                          | M                      | M             |
+| DM-DOCUMENT-SAVE (Note 1)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |                            | M                      | M             |
+| DM-DOCUMENT-DISCARD (Note 1)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |                            | M                      | M             |
+| DM-DOCUMENT-CLOSE (Note 1)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             | M                          | M                      | M             |
+| DM-POINT (Note 1)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      | U                          | U                      | U             |
+| DM-DOCUMENT-LIST (Note 2)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              | C                          | C                      | C             |
+| DM-GET (Note 3)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        | M                          | M                      | M             |
+| DM-SEARCH (Note 3)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     | M                          | M                      | M             |
+| DM-CREATE (Note 4)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |                            | M                      | M             |
+| DM-DELETE (Note 4)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |                            | M                      | M             |
+| DM-MODIFY (Note 4)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |                            | M                      | M             |
+| DM-COPY (Note 4)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                            | M                      | M             |
+| DM-MOVE (Note 5)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                            |                        | M             |
+| DM-REPLACE (Note 5)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |                            |                        | M             |
+| DM-RESERVE (Note 5)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |                            |                        | M             |
+| DM-UNRESERVE (Note 5)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |                            |                        | M             |
+| DM-MACRO-CALL (Note 6)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 | FS                         | FS                     | FS            |
+| DM-GROUP-BEGIN (Note 6)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                | FS                         | FS                     | FS            |
+| DM-GROUP-END (Note 6)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  | FS                         | FS                     | FS            |
+| NOTES<br>1 The abstract services DM-DOCUMENT-OPEN and DM-DOCUMENT-CLOSE have to be supported by all values of manipulationLevelSelection. The use of the DM-POINT service is optional (U).<br>2 The use of the DM-DOCUMENT-LIST abstract service is not allowed in combined DTAM-DM/DFR applications. In such a case the DFR list abstract service shall be used instead (C).<br>3 Additionally to the abstract services listed in Note 1, the abstract services DM-GET and DM-SEARCH have to be supported if the value of manipulationLevelSelection is basicReadOnlyLevel (M), other abstract services are not applicable (<blank>).<br>4 Additionally to the abstract services listed in Note 3, the abstract services DM-DOCUMENT-SAVE, DM-DOCUMENT-DISCARD, DM-CREATE, DM-DELETE, DM-MODIFY and DM-COPY have to be supported if the value of manipulationLevelSelection is basicManipulationLevel (M), other abstract services are not applicable (<blank>).<br>5 Additionally to the abstract services listed in Note 4, the abstract services DM-MOVE, DM-REPLACE, DM-RESERVE, DM-UNRESERVE and DM-POINT have to be supported if the value of manipulationLevelSelection is extendedLevel (M).<br>6 The support of the abstract services DM-MACRO-CALL, DM-GROUP-BEGIN and DM-GROUP-END is for further study for all values of manipulationLevelSelection (FS). |                            |                        |               |
+
+#### 8.1.1.2 Bind-result parameters
+
+The DtamDmBindResult parameter indicates the capabilities supported by the DTAM-DM server.
+
+**DtamDmBindResult ::= [1] SEQUENCE {**  
+    **serverSelectedDtamProtocolVersion** [0] BIT STRING  
+        { version-1 (0) } DEFAULT {version-1},  
+    **odaApplicationCapabilities** [1] SEQUENCE OF OdaApplicationCapabilities,  
+    **serverSelectedDfrVersion** [2] BIT STRING  
+        { version-1 (1),  
+          version-2 (2) } OPTIONAL,  
+    **bilateralInformation** [3] SEQUENCE OF  
+        BilateralInformation OPTIONAL }
+
+- a) **serverSelectedDtamProtocolVersion:** The parameter indicates the DTAM-DM protocol version which the DTAM-DM server selected from those proposed by the DTAM-DM client. It is a variable length bit string where only the version selected is set to one. The value of this parameter defines the protocol version to be used for this association.
+- b) **odaApplicationCapabilities:** This parameter specifies the document application profile and, optionally, two other parameters as the receiving capabilities of the DTAM-DM server. The continued progress of the service is only guaranteed if the DTAM-DM client acts within the receiving capabilities of the DTAM-DM server.
+- c) **serverSelectedDfrProtocolVersion:** This parameter is optional and shall only be used in the DTAM-DM/DFR environment. The parameter indicates the DFR protocol version which the DTAM-DM/DFR server selected from those proposed by the DTAM-DM/DFR client. It is a variable length bit string where only the version selected is set to one. The value of this parameter defines the protocol version to be used for this association.
+- d) **bilateralInformation:** This parameter includes bilateral information between DTAM-DM server and DTAM-DM client.
+
+#### 8.1.1.3 Bind-error parameters
+
+The DtamDMBindError parameter reports the errors that may occur during association establishment.
+
+DmServiceProblem reports that the DTAM-DM server cannot establish the association due to some operational error.
+
+The parameter ProtocolProblem indicates that the DTAM-DM server does not support the requested protocol versions. If the DTAM-DM server does not support the requested DTAM-DM or DFR protocol version proposed by the DTAM-DM client, it may optionally indicate the protocol versions which could be supported by the DTAM-DM server.
+
+The parameter ProfileProblem indicates that the DTAM-DM server does not support the requested profiles of the protocol. If the DTAM-DM server does not support the requested DTAM-DM or DFR profiles by the DTAM-DM client, it may optionally indicate the profile which could be supported by the DTAM-DM server.
+
+The DmServiceProblem paramter is also used in the DTAM-DM operations and defined in 9.4.8.
+
+The parameter ApplicationProblem indicates that the DTAM-DM server does not support the requested application requirements. If the DTAM-DM server does not support the requested application requirements, it may optionally indicate the application requirements which could be supported by the DTAM-DM server.
+
+**DtamDmBindError ::= [2] CHOICE {**  
+    **serviceError** [0] DmServiceProblem,  
+    **protocolError** [1] ProtocolProblem,  
+    **profileError** [2] ProfileProblem,  
+    **applicationError** [3] ApplicationProblem }
+
+**ProtocolProblem ::= SEQUENCE {**  
+    **protocol-version-not-supported** [0] SEQUENCE OF ENUMERATED {  
+        dtam-version-not-supported (0),  
+        dfr-version-not-supported (1) },  
+    **supportedDtamProtocolVersions** [1] BIT STRING  
+        { version-1 (0) } OPTIONAL,  
+    **supportedDfrProtocolVersions** [2] BIT STRING  
+        { version-1 (0),  
+          version-2 (1) } OPTIONAL }
+
+**ProfileProblem ::= SEQUENCE {**  
+     **profile-not-supported** [0] SEQUENCE OF ENUMERATED {  
+         **dtam-manipulation-level-not-supported** (0),  
+         **dfr-profile-not-supported** (1) },  
+     **supportedDtamManipulationLevels** [1] SEQUENCE OF ManipulationCapabilities  
+         OPTIONAL,  
+     **supportedDfrProfiles** [2] SEQUENCE OF OBJECT IDENTIFIER  
+         OPTIONAL }
+
+**ApplicationProblem ::= SEQUENCE OF ApplicationRequirements OPTIONAL**
+
+### 8.1.2 ABSTRACT-UNBIND parameters
+
+This subclause defines and describes the unbind-operation parameters for the DTAM-DM, DTAM-DM-SYM, DFR and DTAM-TK port depending on the environment. There are no arguments or errors associated with the unbind-operation.
+
+**DTAM-DMUnBind ::= ABSTRACT-UNBIND**  
+**FROM {dtam-dm-port[S], dfr-port[S], dtam-dm-sym-port, dtam-tk-port}**
+
+## 8.2 Use of the A-ABORT service
+
+The A-ABORT service is initiated by either the client or server to dissolve unconditionally an association. The encoding of the DTAM-DMAbortInfo, which is mapped to the A-ABORT “user information” parameter, is defined by using the ASN.1 EXTERNAL data type.
+
+The DtamDmAbortSource parameter indicates the source of the association abort, if it is the DTAM-DM service provider or service user. The DtamDmAbortReason parameter indicates the reason for the abort. The value “temporary-problem” indicates, that no attempt at association-recovery should be made for a period of time determined by a local rule.
+
+**DTAM-DMAbortInfo ::= [3] SEQUENCE {**  
+     **abortSource** [0] DtamDmAbortSource,  
+     **abortReason** [1] DtamDmAbortReason OPTIONAL,  
+     **userInformation** [2] EXTERNAL OPTIONAL }
+
+**DtamDmAbortSource ::= ENUMERATED {**  
+     **dtamDmServiceUser** (0),  
+     **dtamDmServiceProvider** (1) }
+
+**DtamDmAbortReason ::= ENUMERATED {**  
+     **local-system-problem** (0),  
+     **temporary-problem** (1),  
+     **protocol-error** (2) }
+
+# 9 Definition of abstract services
+
+This clause provides the definition of the DTAM-DM and DTAM-TK abstract services. The complete formal definition is contained in Annex B.
+
+Some data types used in these definitions are defined in other Recommendations or international standards. These data types are imported by this Recommendation.
+
+An argument of any DTAM-DM or DTAM-TK abstract service is a sequence of parameters, some of them being mandatory for the given abstract service, while others are optional. Some of the parameters may be common to all or most of the services. These parameters are defined as common data types.
+
+The definitions of the DTAM-DM and the DTAM-TK abstract services are given in separate subclauses.
+
+## 9.1 Imported data types
+
+From ODA (Recommendation T.413):
+
+**ConstituentType,**  
+**ConstituentIdentifier,**  
+**AttributeValuesType,**  
+**QueryType**
+
+From ODA (Recommendation T.415):
+
+**Non-Basic-Doc-Characteristics,  
+Non-Basic-Struc-Characteristics.  
+Document-Reference**
+
+From ODA (Recommendation T.422):
+
+**Location-expression,  
+Basic-location-expression,  
+Constituent-Locator**
+
+From DFR (ISO/IEC 10166):
+
+**DfrEntryName,**
+
+From MHS (Recommendation X.407):
+
+**ABSTRACT-BIND,  
+ABSTRACT-UNBIND,  
+ABSTRACT-ERROR,  
+ABSTRACT-OPERATION,  
+OBJECT,  
+PORT**
+
+From DS (Recommendation X.500):
+
+**DistinguishedName**
+
+## **9.2 Defined data types common for abstract services**
+
+The following data types are defined as common data types in this Recommendation:
+
+**DocumentId  
+ManipulationObject  
+ObjectValue  
+ObjectPosition  
+ObjectContent  
+AssignedId  
+NonPermanentIdentifier**
+
+### **9.2.1 DocumentIdentification**
+
+**DocumentId ::= CHOICE {  
+    dfrName [0] DfrEntryName,  
+    documentReference [1] Document-Reference,  
+    documentName [2] OCTET STRING,  
+    nonPermanentIdentifier [3] NonPermanentIdentifier }**
+
+### **9.2.2 ManipulationObject**
+
+**ManipulationObject ::= SEQUENCE {  
+    documentIdentifier [0] DocumentId OPTIONAL,  
+    objectValue [1] ObjectValue OPTIONAL }**
+
+### **9.2.3 ObjectValue**
+
+**ObjectValue ::= CHOICE {  
+    odaExpression [0] Oda-expression,  
+    otherExpression [1] OCTET STRING,  
+    anyExpression [2] ANY }**
+
+### **9.2.4 Oda-Expression**
+
+**Oda-Expression ::= CHOICE {  
+    locationExpression [0] Location-Expression,  
+    basicLocationExpression [1] basic-Location-Expression,  
+    constituentLocator [2] Constituent-Locator,  
+    ConstituentIdentifier [3] Constituent-Identifier }**
+
+### 9.2.5 ObjectPosition
+
+**ObjectPosition ::= ENUMERATED {**  
+    **before** (0),  
+    **afterLastChild** (1) **}**
+
+### 9.2.6 ObjectContent
+
+**ObjectContent ::= CHOICE {**  
+    **odaContent** [0] **ConstituentType,**  
+    **octetAligned** [1] **OCTET STRING,**  
+    **anyContent** [2] **ANY }**
+
+### 9.2.7 AssignedId
+
+**AssignedId ::= CHOICE {**  
+    **odaIdentifier** [0] **ConstituentIdentifier,**  
+    **nonOdaIdentifier** [1] **INTEGER,**  
+    **any** [2] **ANY }**
+
+### 9.2.8 NonPermanentIdentifier
+
+**NonPermanentIdentifier ::= CHOICE {**  
+    [0] **INTEGER,**  
+    [1] **OCTET STRING}**
+
+## 9.3 Definition of DTAM-DM abstract services
+
+This Recommendation defines the following DTAM-DM abstract services:
+
+- DM-DOCUMENT-OPEN;
+- DM-DOCUMENT-SAVE;
+- DM-DOCUMENT-DISCARD;
+- DM-DOCUMENT-CLOSE;
+- DM-DOCUMENT-LIST;
+- DM-GET;
+- DM-SEARCH;
+- DM-CREATE;
+- DM-DELETE;
+- DM-MODIFY;
+- DM-COPY;
+- DM-MOVE;
+- DM-REPLACE;
+- DM-RESERVE;
+- DM-UNRESERVE;
+- DM-POINT;
+- DM-MACRO-CALL;
+- DM-GROUP-BEGIN;
+- DM-GROUP-END.
+
+The DTAM-DM abstract services are described according to the definition of the abstract operations macro in Recommendation X.407. In the DTAM-DM or DTAM-DM/DFR environment, all abstract operations are invoked by the consumer (DTAM-DM or DTAM-DM/DFR client) . In the DTAM-DM/DTAM-TK environment all abstract operations are invoked by the actual client (The application token decides whether the DTAM-DM/DTAM-TK client/server is server or client for a specific moment). Each abstract operation always reports either success or an error. The abstract operations are mapped on the ROSE services defined in Recommendation X.219.
+
+These DTAM-DM abstract services are defined in the following subclauses.
+
+### 9.3.1 DM-DOCUMENT-OPEN abstract service
+
+The document open abstract service is used by the DTAM-DM client to select and open documents prior to document manipulations. No inner manipulations can take place on documents which were not opened before. Several documents may be opened at the same time.
+
+**DM-DOCUMENT-OPEN ::= ABSTRACT-OPERATION**
+
+|                 |                                   |
+|-----------------|-----------------------------------|
+| <b>ARGUMENT</b> | <b>DM-DOCUMENT-OPEN-Arguments</b> |
+| <b>RESULT</b>   | <b>DM-DOCUMENT-OPEN-Result</b>    |
+| <b>ERRORS</b>   |                                   |
+| {               |                                   |
+|                 | DM-DocumentError,                 |
+|                 | DM-AccessError,                   |
+|                 | DM-ServiceError                   |
+| }               |                                   |
+
+**DM-DOCUMENT-OPEN-Arguments ::= SEQUENCE**
+
+|   |            |                       |
+|---|------------|-----------------------|
+| { |            |                       |
+|   | documentId | [0] DocumentId,       |
+|   | mode       | [1] ModeType OPTIONAL |
+| } |            |                       |
+
+**ModeType ::= ENUMERATED{ read (0), modify (1), create (2) }**
+
+**DM-DOCUMENT-OPEN-Result ::= CHOICE**
+
+|   |                        |                            |
+|---|------------------------|----------------------------|
+| { |                        |                            |
+|   | noValue                | [0] NULL,                  |
+|   | nonPermanentIdentifier | [1] NonPermanentIdentifier |
+| } |                        |                            |
+
+#### 9.3.1.1 Arguments
+
+The documentId parameter is mandatory and identifies the selected document for further manipulation. The mode parameter is optional and may have three values: 'read', 'modify' and 'create'. If a document is opened with “mode” equal to 'read', it will only be possible to perform read operations on it. In case it is opened with “mode” equal to 'modify', it will be possible to apply all manipulation operations. Finally, the 'create' value means that the document is to be created. In this latter case, the permanent identifier is the identification to be given to the document.
+
+#### 9.3.1.2 Result
+
+The DM-DOCUMENT-OPEN-Result will be returned in case of success. It either carries a nonPermanentIdentifier, which will be used up to the related DM-DOCUMENT-CLOSE operation, where a new permanent identifier will be assigned, or carries no parameter, which implies that the relevant permanent identifier is used throughout the manipulation phase.
+
+#### 9.3.1.3 Errors
+
+The reasons for giving an error in the open service are:
+
+- DM-DocumentError: The documentId parameter does not indicate an existing document.
+- DM-AccessError: The document is already opened by the user, is reserved or the user has no valid access rights.
+- DM-ServiceError: The document cannot be opened due to local reasons.
+
+### 9.3.2 DM-DOCUMENT-SAVE abstract service
+
+The document save abstract service is used by the DTAM-DM client to save documents after document manipulations. This operation is of dedicated importance when used before the DM-DOCUMENT-CLOSE.
+
+```
+
+DM-DOCUMENT-SAVE ::= ABSTRACT-OPERATION
+  ARGUMENT      DM-DOCUMENT-SAVE-Arguments
+  RESULT        DM-DOCUMENT-SAVE-Result
+  ERRORS
+  {
+    DM-AccessError,
+    DM-DocumentError,
+    DM-ServiceError
+  }
+
+```
+
+```
+
+DM-DOCUMENT-SAVE-Arguments ::= SEQUENCE
+{
+  documentId      [0] DocumentId
+}
+
+```
+
+```
+
+DM-DOCUMENT-SAVE-Result ::= NULL
+
+```
+
+#### 9.3.2.1 Arguments
+
+The documentId parameter is mandatory and identifies the selected document for the save service.
+
+#### 9.3.2.2 Result
+
+If the request succeeds, the DM-DOCUMENT-SAVE-Result will be returned. There are no parameters.
+
+In this case, all manipulations that have been invoked since the last DM-DOCUMENT-OPEN, DM DOCUMENT-SAVE or DM-DOCUMENT-DISCARD are permanently stored.
+
+#### 9.3.2.3 Errors
+
+The reasons for giving an error in the save service are:
+
+- **DM-AccessError:** The document is not opened or is reserved by some other user or the user has no valid access rights.
+- **DM-DocumentError:** The document-ID parameter does not indicate an existing document.
+- **DM-ServiceError:** The document cannot be saved due to local reasons.
+
+### 9.3.3 DM-DOCUMENT-DISCARD abstract service
+
+The document discard abstract service is used by the DTAM-DM client to discard document manipulations which were done since the use of the last document save, open or discard abstract service.
+
+```
+
+DM-DOCUMENT-DISCARD ::= ABSTRACT-OPERATION
+  ARGUMENT      DM-DOCUMENT-DISCARD-Arguments
+  RESULT        DM-DOCUMENT-DISCARD-Result
+  ERRORS
+  {
+    DM-AccessError,
+    DM-DocumentError,
+    DM-ServiceError
+  }
+
+```
+
+```
+
+DM-DOCUMENT-DISCARD-Arguments ::= SEQUENCE
+{
+  documentId      [0] DocumentId
+}
+
+```
+
+```
+
+DM-DOCUMENT-DISCARD-Result ::= NULL
+
+```
+
+#### 9.3.3.1 Arguments
+
+The documentId parameter is mandatory and identifies the selected document for the discard service. The modifications done on the document since the last save, open or discard operation are discarded.
+
+#### 9.3.3.2 Result
+
+If the request succeeds, the DM-DOCUMENT-DISCARD-Result will be returned. There are no parameters.
+
+#### 9.3.3.3 Errors
+
+The reasons for giving an error in the discard service are:
+
+- **DM-AccessError:** The document is not opened or is reserved by another user or the user has no valid access rights.
+- **DM-DocumentError:** The document-ID parameter does not indicate an existing document.
+- **DM-ServiceError:** The document cannot be discarded due to local reasons.
+
+### 9.3.4 DM-DOCUMENT-CLOSE abstract service
+
+The document close abstract service is used by the DTAM-DM client to close and derelict documents after document manipulations. The modifications which were done since the use of the last DM-DOCUMENT-OPEN, DM-DOCUMENT-SAVE or DM-DOCUMENT-DISCARD abstract service are discarded. To save the document contents before the document will be closed, the DM-DOCUMENT-SAVE abstract service must be used.
+
+**DM-DOCUMENT-CLOSE ::= ABSTRACT-OPERATION**
+
+|                 |                                    |
+|-----------------|------------------------------------|
+| <b>ARGUMENT</b> | <b>DM-DOCUMENT-CLOSE-Arguments</b> |
+| <b>RESULT</b>   | <b>DM-DOCUMENT-CLOSE-Result</b>    |
+| <b>ERRORS</b>   |                                    |
+| {               |                                    |
+|                 | <b>DM-AccessError,</b>             |
+|                 | <b>DM-DocumentError,</b>           |
+|                 | <b>DM-ServiceError</b>             |
+| }               |                                    |
+
+**DM-DOCUMENT-CLOSE-Arguments ::= SEQUENCE**
+
+|   |                                  |
+|---|----------------------------------|
+| { |                                  |
+|   | <b>documentId</b> [0] DocumentId |
+| } |                                  |
+
+**DM-DOCUMENT-CLOSE-Result ::= CHOICE**
+
+|   |                                   |
+|---|-----------------------------------|
+| { |                                   |
+|   | <b>noValue</b> NULL,              |
+|   | <b>permanentId</b> [0] DocumentId |
+| } |                                   |
+
+#### 9.3.4.1 Arguments
+
+The documentId parameter is mandatory and identifies the selected document for the close service.
+
+#### 9.3.4.2 Result
+
+If the request succeeds, the DM-DOCUMENT-CLOSE-Result carries a permanent identifier, which the server has assigned to the manipulated document. This is only the case, if a nonPermanentIdentifier was used during manipulation (since the DM-DOCUMENT-OPEN). If the permanent identifier was used, no value is returned.
+
+#### 9.3.4.3 Errors
+
+The reasons for giving an error in the close service are:
+
+- **DM-AccessError:** The document is not opened by the user or is reserved or the user has no valid access rights.
+- **DM-DocumentError:** The document-ID parameter does not indicate an existing document.
+- **DM-ServiceError:** The document cannot be closed due to local reasons.
+
+### 9.3.5 DM-DOCUMENT-LIST abstract service
+
+The document list abstract service is used by the DTAM-DM client to request a list of document identifications from the DTAM-DM server that are in-line with the indicated criteria. The use of the document list service is restricted to applications that have limited filing and retrieval capabilities. For applications that support both, filing and retrieval as well as manipulation, the combined usage of DFR and DTAM-DM is recommended.
+
+```
+
+DM-DOCUMENT-LIST ::= ABSTRACT-OPERATION
+    ARGUMENT          DM-DOCUMENT-LIST-Arguments
+    RESULT             DM-DOCUMENT-LIST-Result
+    ERRORS
+    {
+        DM-ListError,
+        DM-ServiceError
+    }
+
+```
+
+```
+
+DM-DOCUMENT-LIST-Arguments ::= CHOICE
+    {
+        odaCriteria      [0] QueryType,
+        otherCriteria     [1] OtherCriteria,
+        anyCriteria       [2] ANY
+    }
+
+```
+
+```
+
+OtherCriteria ::= CHOICE {
+    all           [0] BOOLEAN,
+    prefix        [1] OCTET STRING,
+    suffix        [2] OCTET STRING }
+
+```
+
+```
+
+DM-DOCUMENT-LIST-Result ::= SEQUENCE OF DocumentId
+
+```
+
+#### 9.3.5.1 Arguments
+
+The parameter `odaCriteria` is a query that consists of a logical expression comprising attributes and their values of an ODA document profile. It is defined in Recommendation T.413.
+
+The parameter `OtherCriteria` can be applied to any type of document. It can consist of three different selection criteria. The `all` parameter requires to list all documents. The `prefix` parameter requires to list all documents with document names started with the same string as the prefix. The `suffix` parameter requires to list all documents with document names ending with the same string as the suffix.
+
+The parameter `anyCriteria` requires to list all documents with document names matching the given criteria.
+
+#### 9.3.5.2 Result
+
+As a result, a list of `documentIds` is returned. The document names of these `documentIds` fulfill the specified list criteria.
+
+#### 9.3.5.3 Errors
+
+The reasons for giving an error in the list service are:
+
+- `DM-ListError`: The specified list criteria cannot be accepted.
+- `DM-ServiceError`: The list operation cannot be performed due to local reasons.
+
+### 9.3.6 DM-GET abstract service
+
+The get abstract service is used by the DTAM-DM client to read document fragments.
+
+```
+
+DM-GET ::= ABSTRACT-OPERATION
+    ARGUMENT          DM-GET-Arguments
+    RESULT             DM-GET-Result
+    ERRORS
+    {
+        DM-AccessError,
+        DM-FragmentError,
+        DM-DocumentError,
+        DM-ServiceError
+    }
+
+```
+
+```
+
+DM-GET-Arguments ::= SEQUENCE
+{
+    object          [0] ManipulationObject
+}
+
+```
+
+```
+
+DM-GET-Result ::= SEQUENCE OF SEQUENCE OF ObjectContent
+
+```
+
+#### 9.3.6.1 Arguments
+
+The object parameter is mandatory and carries a 'Location-expression' to identify the selected document and document fragment for the get service.
+
+#### 9.3.6.2 Result
+
+Upon successful completion of the get operation, the result parameter returns the content of the object.
+
+#### 9.3.6.3 Errors
+
+The reasons for giving an error in the get service are:
+
+- **DM-AccessError:** The document is not opened or is reserved by another user.
+- **DM-FragmentError:** The object parameter does not indicate an existing document fragment.
+- **DM-DocumentError:** The document-ID parameter does not indicate an existing document.
+- **DM-ServiceError:** The get operation cannot be performed due to local reasons.
+
+### 9.3.7 DM-SEARCH abstract service
+
+The search abstract service is used by the DTAM-DM client to search for specified document fragments. The DTAM-DM client specifies search domains (e.g. to search only in the first chapter) and search criteria. The search abstract service may be used to identify document fragments for invocation of subsequent abstract operations like modify or create, among others.
+
+**DM-SEARCH ::= ABSTRACT-OPERATION**
+
+|                 |                            |  |
+|-----------------|----------------------------|--|
+| <b>ARGUMENT</b> | <b>DM-SEARCH-Arguments</b> |  |
+| <b>RESULT</b>   | <b>DM-SEARCH-Result</b>    |  |
+| <b>ERRORS</b>   |                            |  |
+| {               |                            |  |
+|                 | <b>DM-AccessError,</b>     |  |
+|                 | <b>DM-FragmentError,</b>   |  |
+|                 | <b>DM-DocumentError,</b>   |  |
+|                 | <b>DM-ServiceError</b>     |  |
+| }               |                            |  |
+
+**DM-SEARCH-Arguments ::= SEQUENCE**
+
+|   |               |                                |
+|---|---------------|--------------------------------|
+| { | <b>object</b> | <b>[0] ManipulationObject,</b> |
+|   | <b>limit</b>  | <b>[1] INTEGER OPTIONAL</b>    |
+| } |               |                                |
+
+**DM-SEARCH-Result ::= SEQUENCE**
+
+|   |                   |                                        |
+|---|-------------------|----------------------------------------|
+| { |                   |                                        |
+|   | <b>objectList</b> | <b>[0] SEQUENCE OF DocFragment-Id,</b> |
+|   | <b>number</b>     | <b>[1] INTEGER</b>                     |
+| } |                   |                                        |
+
+**DocFragment-Id ::= ConstituentIdentifier**
+
+#### 9.3.7.1 Arguments
+
+The object parameter is mandatory and carries a 'Location-expression' to identify the selected document and document fragment for the search service. The limit parameter is optional and indicates the maximum number of objects to be returned by the search service.
+
+#### 9.3.7.2 Result
+
+The objectList parameter contains all object identifications found by the search service. The number parameter indicates the number of found objects. If limit was given, number is not greater than limit. If there are more objects which fulfill the search critera, the operation stops.
+
+#### 9.3.7.3 Errors
+
+The reasons for giving an error in the search service are:
+
+- **DM-AccessError:** The document is not opened or is reserved by another user.
+- **DM-FragmentError:** The object parameter does not indicate an existing document fragment.
+- **DM-DocumentError:** The document-ID parameter does not indicate an existing document.
+- **DM-ServiceError:** The search operation cannot be performed due to local reasons.
+
+### 9.3.8 DM-CREATE abstract service
+
+The create abstract service is used by the DTAM-DM client to add document fragments to an existing document. The create abstract service may carry the document fragment, including the values applicable to the created document fragment. The DTAM-DM client must specify the position of the additional document fragment inside the document.
+
+**DM-CREATE ::= ABSTRACT-OPERATION**
+
+|                 |                            |
+|-----------------|----------------------------|
+| <b>ARGUMENT</b> | <b>DM-CREATE-Arguments</b> |
+| <b>RESULT</b>   | <b>DM-CREATE-Result</b>    |
+| <b>ERRORS</b>   |                            |
+| {               |                            |
+|                 | <b>DM-AccessError,</b>     |
+|                 | <b>DM-FragmentError,</b>   |
+|                 | <b>DM-DocumentError,</b>   |
+|                 | <b>DM-AttributeError,</b>  |
+|                 | <b>DM-UpdateError,</b>     |
+|                 | <b>DM-ServiceError</b>     |
+| }               |                            |
+
+**DM-CREATE-Arguments ::= SEQUENCE**
+
+|   |                    |                                               |
+|---|--------------------|-----------------------------------------------|
+| { |                    |                                               |
+|   | <b>destination</b> | [0] <b>ManipulationObject,</b>                |
+|   | <b>position</b>    | [1] <b>ObjectPosition,</b>                    |
+|   | <b>content</b>     | [2] <b>SEQUENCE OF ObjectContent OPTIONAL</b> |
+| } |                    |                                               |
+
+**DM-CREATE-Result ::= CHOICE**
+
+|   |                   |                                   |
+|---|-------------------|-----------------------------------|
+| { |                   |                                   |
+|   | <b>noValue</b>    | [0] <b>NULL,</b>                  |
+|   | <b>assignedID</b> | [1] <b>SEQUENCE OF AssignedId</b> |
+| } |                   |                                   |
+
+#### 9.3.8.1 Arguments
+
+The destination parameter identifies the selected document and document fragment for the create service. It carries a 'Constituent-Locator'. The position parameter identifies the position of the document fragment in the selected document. The content parameter contains the information of the document fragment to be included in the selected document.
+
+In normal cases, all parameters defined in the DM-CREATE-argument are specified. However, if this abstract service is used to create a new paragraph, not inserting document fragment from client to server, but instantiating a subordinate structure by referring to generic structures or defaulting rules specified in ODA document stored in server, the parameter "content" may not be used.
+
+#### 9.3.8.2 Result
+
+The DM-DOCUMENT-CREATE-Result may carry no parameters or the sequence of new identifiers of the fragments.
+
+#### 9.3.8.3 Errors
+
+The reasons for giving an error in the create service are:
+
+- **DM-AccessError:** The documentId does not indicate an opened document or the user has no valid access rights or the document is reserved by another user.
+- **DM-FragmentError:** The destination parameter does not indicate an existing document fragment.
+- **DM-DocumentError:** The document-ID parameter does not indicate an existing document.
+
+
+
+#### **DM-MODIFY ::= ABSTRACT-OPERATION**
+
+|                 |                            |
+|-----------------|----------------------------|
+| <b>ARGUMENT</b> | <b>DM-MODIFY-Arguments</b> |
+| <b>RESULT</b>   | <b>DM-MODIFY-Result</b>    |
+| <b>ERRORS</b>   |                            |
+| {               |                            |
+|                 | <b>DM-AccessError,</b>     |
+|                 | <b>DM-DocumentError,</b>   |
+|                 | <b>DM-FragmentError,</b>   |
+|                 | <b>DM-AttributeError,</b>  |
+|                 | <b>DM-UpdateError,</b>     |
+|                 | <b>DM-ServiceError</b>     |
+| }               |                            |
+
+#### **DM-MODIFY-Arguments ::= SEQUENCE**
+
+|   |                      |                                |
+|---|----------------------|--------------------------------|
+| { |                      |                                |
+|   | <b>object</b>        | <b>[0] ManipulationObject,</b> |
+|   | <b>modifications</b> | <b>[1] ModificationsType</b>   |
+| } |                      |                                |
+
+##### **DM-MODIFY-Result ::= NULL**
+
+##### **ModificationsType ::= CHOICE**
+
+|   |                           |                              |
+|---|---------------------------|------------------------------|
+| { |                           |                              |
+|   | <b>odaModifications</b>   | <b>[0] OdaModifications,</b> |
+|   | <b>otherModifications</b> | <b>[1] OCTET STRING,</b>     |
+|   | <b>anyModifications</b>   | <b>[2] ANY</b>               |
+| } |                           |                              |
+
+##### **OdaModifications ::= SEQUENCE**
+
+|   |                       |                                  |
+|---|-----------------------|----------------------------------|
+| { |                       |                                  |
+|   | <b>attributeValue</b> | <b>[0] AttributeValuesType,</b>  |
+|   | <b>deleting</b>       | <b>[1] BOOLEAN DEFAULT FALSE</b> |
+| } |                       |                                  |
+
+#### **9.3.10.1 Arguments**
+
+The object parameter is mandatory and carries a 'Location-expression' to identify the selected document and document fragment for the modify service. The modifications parameter contains the new values of the attributes of the identified document fragment.
+
+#### **9.3.10.2 Result**
+
+If the request succeeds, the DM-MODIFY-Result will be returned. There are no parameters.
+
+#### **9.3.10.3 Errors**
+
+The reasons for giving an error in the modify service are:
+
+- **DM-AccessError:** The document is not opened or is reserved by another user or the user has no valid access rights.
+- **DM-FragmentError:** The object parameter does not indicate an existing document fragment.
+- **DM-AttributeError:** It is not possible to modify the attribute value.
+- **DM-DocumentError:** The document-ID parameter does not indicate an existing document.
+- **Dm-UpdateError:** It is not possible to modify a document fragment.
+- **DM-ServiceError:** The document fragment cannot be modified due to local reasons.
+
+### **9.3.11 DM-COPY abstract service**
+
+The copy abstract service is used by the DTAM-DM client to duplicate document fragments to another position of the same or a different document.
+
+#### **DM-COPY ::= ABSTRACT-OPERATION**
+
+|                 |                          |
+|-----------------|--------------------------|
+| <b>ARGUMENT</b> | <b>DM-COPY-Arguments</b> |
+| <b>RESULT</b>   | <b>DM-COPY-Result</b>    |
+| <b>ERRORS</b>   |                          |
+| {               |                          |
+|                 | DM-AccessError,          |
+|                 | DM-DocumentError,        |
+|                 | DM-FragmentError,        |
+|                 | DM-AttributeError,       |
+|                 | DM-UpdateError,          |
+|                 | DM-ServiceError          |
+| }               |                          |
+
+#### **DM-COPY-Arguments ::= SEQUENCE**
+
+|             |                                  |
+|-------------|----------------------------------|
+| {           |                                  |
+| source      | [0] ManipulationObject OPTIONAL, |
+| destination | [1] ManipulationObject OPTIONAL, |
+| position    | [2] ObjectPosition OPTIONAL      |
+| }           |                                  |
+
+**DM-COPY-Result ::= SEQUENCE { newConstituent [0] ManipulationObject }**
+
+#### **9.3.11.1 Arguments**
+
+The source parameter carries a 'Basic-location-expression' to identify the selected document and document fragment to be copied. The destination parameter identifies the document and document fragment which is the destination of the copy service. It carries a 'Constituent-Locator'. The position parameter identifies the position of the document fragment in the destination document which may be the same or a different document.
+
+In normal cases, all the parameters defined in DM-COPY-arguments should be used. In exceptional cases, the parameters defined in DM-COPY-arguments may be omitted as follows:
+
+- If the DM-COPY-argument is used to extract fragments from the buffer and to insert these document fragments into the target document, the parameter “source” may not be used.
+- If the DM-COPY-argument is used to store a document fragment into the buffer with no modifications of the target document, both parameters “destination” and “position” may not be used.
+
+#### **9.3.11.2 Result**
+
+If the request succeeds, the DM-COPY-Result will be returned. The parameter “newConstituent” identifies the new object, by use of a 'constituent-identifier'.
+
+#### **9.3.11.3 Errors**
+
+The reasons for giving an error in the copy service are:
+
+- DM-AccessError: The source and/or destination documentId is not opened or is reserved by another user or the user has no valid access rights.
+- DM-FragmentError: The source and/or destination parameters do not indicate existing document fragments.
+- DM-DocumentError: The document-ID does not indicate an existing source and/or destination document.
+- DM-UpdateError: It is not possible to copy a document fragment.
+- DM-AttributeError: It is not possible to copy attribute values.
+- DM-ServiceError: The copy operation cannot be performed due to local reasons.
+
+### **9.3.12 DM-MOVE abstract service**
+
+The move abstract service is used by the DTAM-DM client to change the position of document fragments inside a document, or from one document to another.
+
+#### **DM-MOVE ::= ABSTRACT-OPERATION**
+
+|                 |                          |
+|-----------------|--------------------------|
+| <b>ARGUMENT</b> | <b>DM-MOVE-Arguments</b> |
+| <b>RESULT</b>   | <b>DM-MOVE-Result</b>    |
+| <b>ERRORS</b>   |                          |
+| {               |                          |
+|                 | DM-AccessError,          |
+|                 | DM-DocumentError,        |
+|                 | DM-FragmentError,        |
+|                 | DM-AttributeError,       |
+|                 | DM-UpdateError,          |
+|                 | DM-ServiceError          |
+| }               |                          |
+
+#### **DM-MOVE-Arguments ::= SEQUENCE**
+
+|   |                                     |
+|---|-------------------------------------|
+| { |                                     |
+|   | source [0] ManipulationObject,      |
+|   | destination [1] ManipulationObject, |
+|   | position [2] ObjectPosition         |
+| } |                                     |
+
+#### **DM-MOVE-Result ::= SEQUENCE**
+
+|   |                                       |
+|---|---------------------------------------|
+| { |                                       |
+|   | newConstituent [0] ManipulationObject |
+| } |                                       |
+
+#### **9.3.12.1 Arguments**
+
+The source parameter carries a 'Basic-location-expression' to identify the selected document and document fragment to be moved. The destination parameter identifies the document and document fragment which is the destination of the move service. It carries a 'Constituent-Locator'. The position parameter identifies the position of the document fragment in the destination document which may be the same or a different document.
+
+#### **9.3.12.2 Result**
+
+If the request succeeds, the DM-MOVE-Result will be returned. The parameter "newConstituent" identifies the new object by use of a 'Constituent-identifier'.
+
+#### **9.3.12.3 Errors**
+
+The reasons for giving an error in the move service are:
+
+- DM-AccessError: The source and/or destination documentId is not opened or is reserved by another user or the user has no valid access rights.
+- DM-FragmentError: The source and/or destination parameters do not indicate existing document fragments.
+- DM-DocumentError: The document-ID does not indicate an existing source and/or destination document.
+- DM-AttributeError: It is not possible to move attribute values.
+- DM-UpdateError: It is not possible to move a document fragment.
+- DM-ServiceError: The move operation cannot be performed due to local reasons.
+
+### **9.3.13 DM-REPLACE abstract service**
+
+The replace abstract service is used by the DTAM-DM client to replace document fragments. The replace abstract service effects the deletion of the identified document fragment and the replacement by the new document fragment.
+
+#### **DM-REPLACE ::= ABSTRACT-OPERATION**
+
+**ARGUMENT**            **DM-REPLACE-Arguments**  
+**RESULT**                **DM-REPLACE-Result**  
+**ERRORS**  
+{  
+    **DM-AccessError,**  
+    **DM-DocumentError,**  
+    **DM-FragmentError,**  
+    **DM-AttributeError,**  
+    **DM-UpdateError,**  
+    **DM-ServiceError**  
+}
+
+#### **DM-REPLACE-Arguments ::= SEQUENCE**
+
+{  
+    **object**        **[0] ManipulationObject,**  
+    **content**       **[1] ObjectContent**  
+}
+
+##### **DM-REPLACE-Result ::= NULL**
+
+#### **9.3.13.1 Arguments**
+
+The object parameter is mandatory and carries a 'Constituent-Locator' to identify the selected document and document fragment for the replace service. The content parameter is mandatory and contains the new document fragment to be inserted.
+
+#### **9.3.13.2 Result**
+
+If the request succeeds, the DM-REPLACE-Result will be returned. There are no parameters.
+
+#### **9.3.13.3 Errors**
+
+The reasons for giving an error in the replace service are:
+
+- DM-AccessError:        The document is not opened or is reserved by another user or the user has no valid access rights.
+- DM-FragmentError:    The object parameter does not indicate an existing document fragment.
+- DM-DocumentError:    The document-ID does not indicate an exisiting document.
+- DM-UpdateError:        It is not possible to replace a document fragment.
+- DM-AttributeError:    It is not possible to replace attribute values.
+- DM-ServiceError:      The replace operation cannot be done due to local reasons.
+
+### **9.3.14 DM-RESERVE abstract service**
+
+The reserve abstract service is used by the DTAM-DM client to establish the reservation of the specified document fragment. The reservation service specifies the document fragment as exclusive-access, which means that other users shall not use the DM-GET, DM-DELETE, DM-MODIFY, DM-COPY, DM-MOVE, DM-REPLACE, DM-RESERVE, DM-UNRESERVE, DM-SEARCH and DM-POINT abstract services that refer to the reserved document fragment.
+
+The document fragment is implicitly unreserved by the DM-CLOSE and explicitly by the DM-UNRESERVE operations.
+
+The reservation process does not apply to ownership or access rights of document parts, which may already be defined for document parts. For ODA documents this is handled by the ODA document profile or subprofile (see Recommendation T.414).
+
+```
+
+DM-RESERVE ::= ABSTRACT-OPERATION
+    ARGUMENT          DM-RESERVE-Arguments
+    RESULT            DM-RESERVE-Result
+    ERRORS
+    {
+        DM-AccessError,
+        DM-DocumentError,
+        DM-FragmentError,
+        DM-ReservationError,
+        DM-ServiceError
+    }
+
+```
+
+```
+
+DM-RESERVE-Arguments ::= SEQUENCE
+{
+    object      [0] ManipulationObject
+}
+
+```
+
+```
+
+DM-RESERVE-Result ::= NULL
+
+```
+
+#### 9.3.14.1 Arguments
+
+The object parameter is mandatory and carries a 'Location-expression' to identify the selected document and document fragment for the reserve service.
+
+#### 9.3.14.2 Result
+
+Should the request succeed, the DM-RESERVE-Result will be returned. There are no parameters.
+
+#### 9.3.14.3 Errors
+
+The reasons for giving an error in the reserve service are:
+
+- **DM-AccessError:** The document is not opened by the user or the user has no valid access rights.
+- **DM-FragmentError:** The object parameter does not indicate an existing document fragment.
+- **DM-DocumentError:** The document-ID parameter does not indicate an existing document.
+- **DM-ReservationError:** The document fragment is reserved.
+- **DM-ServiceError:** The reserve operation cannot be performed due to local reasons.
+
+### 9.3.15 DM-UNRESERVE abstract service
+
+The unreserve abstract service is used by a DTAM-DM client to release a previous reservation of a document fragment done by using the reserve abstract service.
+
+```
+
+DM-UNRESERVE ::= ABSTRACT-OPERATION
+    ARGUMENT          DM-UNRESERVE-Arguments
+    RESULT            DM-UNRESERVE-Result
+    ERRORS
+    {
+        DM-AccessError,
+        DM-DocumentError,
+        DM-FragmentError,
+        DM-ReservationError,
+        DM-ServiceError
+    }
+
+```
+
+```
+
+DM-UNRESERVE-Arguments ::= SEQUENCE
+{
+    object      [0] ManipulationObject
+}
+
+```
+
+```
+
+DM-UNRESERVE-Result ::= NULL
+
+```
+
+#### 9.3.15.1 Arguments
+
+The object parameter is mandatory and carries a 'Location-expression' to identify the selected document and document fragment for the unreserve service.
+
+#### 9.3.15.2 Result
+
+If the request succeeds, the DM-UNRESERVE-Result will be returned. There are no parameters.
+
+#### 9.3.15.3 Errors
+
+The reasons for giving an error in the unreserve service are:
+
+- **DM-AccessError:** The document is not opened by the user or the user has no valid access rights.
+- **DM-FragmentError:** The object parameter does not indicate an existing document fragment.
+- **DM-DocumentError:** The document-ID parameter does not indicate an existing document.
+- **DM-ReservationError:** The document fragment has not been reserved.
+- **DM-ServiceError:** The unreserve operation cannot be performed due to local reasons.
+
+### 9.3.16 DM-POINT abstract service
+
+The point abstract service is used by DTAM-DM clients in multi-user applications like joint-editing or joint-viewing.
+
+**DM-POINT ::= ABSTRACT-OPERATION**
+
+|                 |                           |
+|-----------------|---------------------------|
+| <b>ARGUMENT</b> | <b>DM-POINT-Arguments</b> |
+| <b>RESULT</b>   | <b>DM-POINT-Result</b>    |
+| <b>ERRORS</b>   |                           |
+| {               |                           |
+|                 | <b>DM-AccessError,</b>    |
+|                 | <b>DM-DocumentError,</b>  |
+|                 | <b>DM-FragmentError,</b>  |
+|                 | <b>DM-ServiceError</b>    |
+| }               |                           |
+
+**DM-POINT-Arguments ::= SEQUENCE**
+
+|   |               |                               |
+|---|---------------|-------------------------------|
+| { |               |                               |
+|   | <b>object</b> | <b>[0] ManipulationObject</b> |
+| } |               |                               |
+
+**DM-POINT-Result ::= NULL**
+
+#### 9.3.16.1 Arguments
+
+The object parameter is mandatory and identifies the selected document and document fragment for the point service.
+
+#### 9.3.16.2 Result
+
+If the request succeeds, the DM-POINT-Result will be returned. There are no parameters.
+
+#### 9.3.16.3 Errors
+
+The reasons for giving an error in the point service are:
+
+- **DM-AccessError:** The document is not opened or is reserved by another user.
+- **DM-FragmentError:** The object parameter does not indicate an existing document fragment.
+- **DM-DocumentError:** The document-ID parameter does not indicate an existing document.
+- **DM-ServiceError:** The point operation cannot be performed due to local reasons.
+
+### 9.3.17 DM-MACRO-CALL abstract service
+
+This is for further study.
+
+#### **DM-MACRO-CALL ::= ABSTRACT-OPERATION**
+
+|                        |                                |
+|------------------------|--------------------------------|
+| <b>ARGUMENT</b>        | <b>DM-MACRO-CALL-Arguments</b> |
+| <b>RESULT</b>          | <b>DM-MACRO-CALL-Result</b>    |
+| <b>ERRORS</b>          |                                |
+| {                      |                                |
+| <b>DM-ServiceError</b> |                                |
+| }                      |                                |
+
+**DM-MACRO-CALL-Arguments ::= NULL**
+
+**DM-MACRO-CALL-Result ::= NULL**
+
+#### **9.3.17.1 Arguments**
+
+None.
+
+#### **9.3.17.2 Result**
+
+None.
+
+#### **9.3.17.3 Errors**
+
+The reasons for giving an error in the abstract service are:
+
+- **DM-ServiceError:** The operation cannot be performed due to local reasons.
+
+### **9.3.18 DM-GROUP-BEGIN abstract service**
+
+The group-begin abstract service is used by the DTAM-DM client to indicate the start of a set of DTAM-DM abstract services which are to be processed and responded to as a group.
+
+This is for further study.
+
+#### **DM-GROUP-BEGIN ::= ABSTRACT-OPERATION**
+
+|                        |                                 |
+|------------------------|---------------------------------|
+| <b>ARGUMENT</b>        | <b>DM-GROUP-BEGIN-Arguments</b> |
+| <b>RESULT</b>          | <b>DM-GROUP-BEGIN-Result</b>    |
+| <b>ERRORS</b>          |                                 |
+| {                      |                                 |
+| <b>DM-ServiceError</b> |                                 |
+| }                      |                                 |
+
+**DM-GROUP-BEGIN-Arguments ::=NULL**
+
+**DM-GROUP-BEGIN-Result ::= NULL**
+
+#### **9.3.18.1 Arguments**
+
+None.
+
+#### **9.3.18.2 Result**
+
+None.
+
+#### **9.3.18.3 Errors**
+
+The reasons for giving an error in the abstract service are:
+
+- **DM-ServiceError:** The group-begin operation cannot be performed due to local reasons.
+
+### **9.3.19 DM-GROUP-END abstract service**
+
+The group-end abstract service is used by the DTAM-DM client to indicate the end of a set of DTAM-DM abstract services which are to be processed and responded to as a group.
+
+This is for further study.
+
+```
+
+DM-GROUP-END ::= ABSTRACT-OPERATION
+    ARGUMENT          DM-GROUP-END-Arguments
+    RESULT            DM-GROUP-END-Result
+    ERRORS
+    {
+        DM-ServiceError
+    }
+
+```
+
+**DM-GROUP-END-Arguments ::= NULL**
+
+**DM-GROUP-END-Result ::= NULL**
+
+#### 9.3.19.1 Arguments
+
+None.
+
+#### 9.3.19.2 Result
+
+None.
+
+#### 9.3.19.3 Errors
+
+The reasons for giving an error in the abstract service are:
+
+- **DM-ServiceError:** The group-end operation cannot be performed due to local reasons.
+
+## 9.4 Definitions of DTAM-DM abstract errors
+
+The abstract errors that can be reported in response to the invocation of abstract operations at the DTAM-DM port are defined and described in this subclause.
+
+If any error occurs during the course of an abstract operation invocation, the DTAM-DM server assures that nothing has been changed by the abstract operation.
+
+The list of errors specified in this subclause are the following:
+
+- **DM-AccessError;**
+- **DM-AttributeError;**
+- **DM-UpdateError;**
+- **DM-DocumentError;**
+- **DM-FragmentError;**
+- **DM-ListError;**
+- **DM-ReservationError.**
+- **DM-ServiceError**
+
+Unidentified errors are reported by the relevant parameter of the **DM-Service-Error**.
+
+### 9.4.1 DM-access-error
+
+A **DM-AccessError** reports a problem encountered when attempting to access a document or document fragment specified in the argument of the abstract operation.
+
+```
+
+DM-AccessError ::= ABSTRACT-ERROR
+    PARAMETER CHOICE {
+        docAccessError    [0] DocAccessError,
+        fragAccessError    [1] FragAccessError }
+
+```
+
+```
+
+DocAccessError ::= SEQUENCE {
+    documentId            [0] DocumentId,
+    dmDocAccProblem       [1] DmDocAccProblem }
+
+```
+
+```
+
+DmDocAccProblem ::= ENUMERATED {
+    document-already-open (1),
+    document-not-opened   (2),
+    improper-access-rights (3) }
+
+```
+
+- a) **document-already-open**: The document to be opened has already been opened by the same user;
+- b) **document-not-opened**: The document of the document fragment to be modified, closed or discarded has not been opened yet;
+- c) **improper-access-rights**: An attempt to access the document has been made by a DTAM-DM client with insufficient access rights to this entry. If a DTAM-DM client has no read access right to the document a DM-DocumentError will be reported in order to hide the existence of that document.
+
+**FragAccessError ::= SEQUENCE {**  
+     **entry**                     **[0] ManipulationObject,**  
+     **dmFragAccProblem**       **[1] DmFragAccProblem }**
+
+**DmFragAccProblem ::= ENUMERATED {**  
+     **reserved-by-a-user**       **(1),**  
+     **improper-access-rights**   **(2) }**
+
+- d) **reserved-by-a-user**: The document fragment to be modified is at present reserved by another user;
+- e) **improper-access-rights**: An attempt to access the document fragment has been made by a DTAM-DM client with insufficient access rights to this entry. If a DTAM-DM client has no read access right to the document fragment, a DM-DocumentError will be reported in order to hide the existence of that document.
+
+### 9.4.2 DM-attribute-error
+
+A DM-AttributeError reports a problem encountered while attempting to modify attributes of document fragments.
+
+**DM-AttributeError ::= ABSTRACT-ERROR**  
+     **PARAMETER SEQUENCE {**  
+         **entry**               **[0] ManipulationObject,**  
+         **problems**           **[1] SEQUENCE OF SEQUENCE {**  
+             **problem**       **[0] DmAttributeProblem,**  
+             **type**           **[1] TypeOfAttributeValue OPTIONAL } }**
+
+**DmAttributeProblem ::= ENUMERATED {**  
+     **invalid-syntax**       **(1),**  
+     **constraint-violation**   **(2),**  
+     **illegal-violation**     **(3) }**
+
+**TypeOfAttributeValue ::= CHOICE {**  
+     **odaAttributeValue**     **[0] AttributeValuesType,**  
+     **anyAttributeValue**     **[1] ANY }**
+
+The problems parameter specifies one or several attribute problems encountered. Each problem (identified below) is optional accompanied by the value of the attribute.
+
+- a) **invalid-syntax**: A value, specified in the parameter ModificationsType in the argument of the abstract operation, does not conform to the abstract syntax of the type of the attribute;
+- b) **constraint-violation**: An attribute value supplied in the argument of the abstract operation does not conform to constraints imposed by the standard or document application profile (e.g. the value exceeds the maximum size allowed);
+- c) **illegal-violation**: An attempt was made to modify an attribute which may not be modified by an abstract operation. For ODA documents, the attributes “identifier,” “subordinates” and “content portions” of a constituent shall not be modified (see 7.3.3/T.413).
+
+### 9.4.3 DM-update-error
+
+A DM-UpdateError reports a problem encountered while attempting to modify a document fragment. Deletion, creation, moving, copying and replacing document fragments are also considered here as modifications.
+
+**DM-UpdateError ::= ABSTRACT-ERROR**  
+     **PARAMETER SEQUENCE {**  
+         **entry**               **[0] ManipulationObject,**  
+         **problem**           **[1] DmUpdateProblem }**
+
+**DmUpdateProblem ::= ENUMERATED { illegal-modification     (1) }**
+
+A DmUpdateProblem shall be one of the following:
+
+- a) **illegal-modification**: An attempt has been made to modify a document fragment which would result in an inconsistent state of the document (e.g. to create a logical object in the layout structure of an ODA document).
+
+### 9.4.4 DM-document-error
+
+A DM-DocumentError reports a problem related to the name of a document specified in the argument of an abstract operation. The document which caused a problem is reported as it was specified, accompanied by an indication of the problem encountered. If a DTAM-DM client has no read access to the document, a DM-DocumentError will be reported in order to hide the existence of that document.
+
+**DM-DocumentError ::= ABSTRACT-ERROR**
+
+**PARAMETER SEQUENCE {**  
+**entry** [0] **DocumentId**,  
+**problem** [1] **DmDocumentProblem** }
+
+**DmDocumentProblem ::= ENUMERATED {**
+
+**invalid-upi** (1),  
+**invalid-path-name** (2),  
+**ambiguous-path-name** (3),  
+**invalid-document-reference** (4),  
+**invalid-document-name** (5),  
+**invalid-non-permanent-id** (6) }
+
+- a) **invalid-upi**: The UPI provided in the abstract operation's argument does not refer to any document in the document store;
+- b) **invalid-path-name**: The DfrPathName (either absolute or relative) provided in the abstract operations's argument does not correspond to any existing document in the document store;
+- c) **ambiguous-path-name**: The DfrEntryName provided in the abstract operation's argument is ambiguous, that is, corresponds to more than one document;
+- d) **invalid-document-reference**: The Document-Reference provided in the abstract operation's argument does not correspond to any existing document in the document store;
+- e) **invalid-document-name**: The DocumentName does not refer to any document in the document store;
+- f) **invalid-non-permant-id**: The non-permanent-identifier provided in the abstract operation's argument does not refer to any document in the document store.
+
+### 9.4.5 DM-fragment-error
+
+The DM-FragmentError reports a problem related to the name of the document fragment or the value of the location expression specified in the argument of an abstract operation. The ObjectValue which caused a problem is reported as it was specified, accompanied by an indication of the problem encountered.
+
+**DM-FragmentError ::= ABSTRACT-ERROR**
+
+**PARAMETER SEQUENCE {**  
+**entry** [0] **ObjectValue**,  
+**problem** [1] **DmFragmentProblem** }
+
+**DmFragmentProblem ::= ENUMERATED {**
+
+**invalid-location-expression** (1),  
+**invalid-expression** (2) }
+
+- a) **invalid-location-expression**: The Location-expression provided in the abstract operation's argument does not refer to a document fragment;
+- b) **invalid-expression**: The otherExpression or anyexpression provided in the abstract operation's argument does not refer to a document fragment.
+
+### 9.4.6 DM-list-error
+
+The DM-ListError reports a problem related to the query of the documents available in the document store. The type of query which caused a problem is reported as it was specified.
+
+**DM-ListError ::= ABSTRACT-ERROR**  
+**PARAMETER ListProblem**
+
+**ListProblem ::= CHOICE {**  
+    **all** [0] **BOOLEAN,**  
+    **prefix** [1] **OCTET STRING,**  
+    **suffix** [2] **OCTET STRING,**  
+    **typeOfQuery** [3] **QueryType,**  
+    **anyCriteria** [4] **ANY }**
+
+### 9.4.7 DM-reservation-error
+
+The DM-ReservationError reports a problem occurring when an attempt has been made to reserve or unreserve a document fragment.
+
+**DM-ReserveError ::= ABSTRACT-ERROR**  
+**PARAMETER SEQUENCE {**  
+    **entry** [0] **ManipulationObject,**  
+    **problem** [1] **DmReservationProblem }**
+
+**DmReservationProblem ::= ENUMERATED {**  
+    **already-reserved (1),**  
+    **not-yet-reserved (2) }**
+
+The DmReservationProblem shall be one of the following:
+
+- a) **already-reserved**: An attempt has been made to reserve or unreserve a document fragment which has already been reserved by another user;
+- b) **not-yet-reserved**: An attempt has been made to unreserve a document fragment which is not reserved at the moment.
+
+### 9.4.8 DM-service-error
+
+The DM-ServiceError reports a problem related to the provision of the service, which is not due to an incorrect abstract operation request or the requestor's access rights.
+
+**DM-ServiceError ::= ABSTRACT-ERROR**  
+**PARAMETER DmServiceProblem**
+
+**DmServiceProblem ::= ENUMERATED {**  
+    **server-busy (1),**  
+    **server-unavailable (2),**  
+    **resource-limit-exceeded (3),**  
+    **operation-too-complex (4),**  
+    **unclassified-server-error (5) }**
+
+The DmServiceProblem shall be one of the following:
+
+- a) **server-busy**: The DTAM-DM server is presently too busy to perform the requested abstract operation, but may be able to do so after a short while;
+- b) **server-unavailable**: The DTAM-DM server is currently unavailable. The proposed operation is to unbind DTAM-DM server and DTAM-DM client;
+- c) **resource-limit-exceeded**: The resources of the DTAM-DM server can be exceeded for example when a very large document fragment is to be created or copied in the document store;
+- d) **operation-too-complex**: The requested abstract operation is too complex syntactically or semantically (e.g. the location-expression to determine a document fragment cannot be dissolved);
+- e) **unclassified-server-error**: An error which cannot be categorized in any other way. The reason for this error is implementation specific.
+
+### 9.4.9 Error precedence
+
+Should several error conditions occur simultaneously for the same DTAM-DM abstract operation, only one of them is reported to the requestor. The precedence of these error conditions is as follows beginning with:
+
+- DM-ServiceError;
+- DM-DocumentError;
+- DM-FragmentError;
+- DM-AccessError;
+- DM-ReservationError;
+- DM-AttributeError;
+- DM-UpdateError;
+- DM-ListError.
+
+## 9.5 Definition of DTAM-TK abstract services
+
+This Recommendation defines the following DTAM-TK abstract services:
+
+- TK-TOKEN-GIVE;
+- TK-TOKEN-PLEASE.
+
+These DTAM-TK abstract services are defined in the following subclauses.
+
+### 9.5.1 TK-TOKEN-GIVE abstract service
+
+The token-give abstract service surrenders the application token from a DTAM-TK client/server, who temporarily acts as a client, to a DTAM-TK client/server, who temporarily acts as a server. This abstract operation changes the roles of the DTAM-TK client/server objects in the communication process (from client to server and vice versa).
+
+**TK-TOKEN-GIVE ::= ABSTRACT-OPERATION**
+
+|                        |                                |
+|------------------------|--------------------------------|
+| <b>ARGUMENT</b>        | <b>TK-TOKEN-GIVE-Arguments</b> |
+| <b>RESULT</b>          | <b>TK-TOKEN-GIVE-Result</b>    |
+| <b>ERRORS</b>          |                                |
+| {                      |                                |
+| <b>TK-ServiceError</b> |                                |
+| }                      |                                |
+
+**TK-TOKEN-GIVE-Arguments ::= NULL**
+
+**TK-TOKEN-GIVE-Result ::= NULL**
+
+#### 9.5.1.1 Arguments
+
+None.
+
+#### 9.5.1.2 Result
+
+If the request succeeds, the TK-TOKEN-GIVE-Result will be returned. There are no parameters.
+
+#### 9.5.1.3 Errors
+
+The reasons for giving an error in the abstract service are:
+
+- **TK-ServiceError:** The token-give operation cannot be performed due to local reasons.
+
+### 9.5.2 TK-TOKEN-PLEASE abstract service
+
+The token-please abstract service is used by the DTAM-TK client/server, who temporarily acts as a server, to request the application token from a DTAM-TK client/server, who temporarily acts as a client. This request changes the role of the application entities in the communication process.
+
+The DTAM-TK client/server responds with the TK-TOKEN-GIVE operation if he accepts to exchange the application token. He does not respond if he refuses. The DTAM-TK client/server may respond immediately after reception of the TK-TOKEN-PLEASE abstract operation or may invoke one or more other DTAM-DM operations before he decides to surrender the token.
+
+**TK-TOKEN-PLEASE ::= ABSTRACT-OPERATION**
+
+|                        |                                  |
+|------------------------|----------------------------------|
+| <b>ARGUMENT</b>        | <b>TK-TOKEN-PLEASE-Arguments</b> |
+| <b>RESULT</b>          | <b>TK-TOKEN-PLEASE-Result</b>    |
+| <b>ERRORS</b>          |                                  |
+| {                      |                                  |
+| <b>TK-ServiceError</b> |                                  |
+| }                      |                                  |
+
+**TK-TOKEN-PLEASE-Arguments ::= NULL**
+
+**TK-TOKEN-PLEASE-Result ::= NULL**
+
+#### **9.5.2.1 Arguments**
+
+None.
+
+#### **9.5.2.2 Result**
+
+If the request succeeds, the TK-TOKEN-PLEASE-Result will be returned. There are no parameters.
+
+#### **9.5.2.3 Errors**
+
+The reasons for giving an error in the abstract service are:
+
+- **TK-ServiceError:** The token-please operation cannot be performed due to local reasons.
+
+## **9.6 Definitions of DTAM-TK abstract errors**
+
+The DTAM-TK abstract errors that can be reported in response to the invocation of abstract operations at the DTAM-TK port are defined and described in this subclause.
+
+### **9.6.1 TK-service-error**
+
+The TK-ServiceError reports a problem related to the provision of the service, which is not due to an incorrect abstract operation request or the requestor's access rights.
+
+**TK-ServiceError ::= ABSTRACT-ERROR**
+
+**PARAMETER TKServiceProblem**
+
+**TKServiceProblem ::= ENUMERATED {**  
+    **server-busy** (1),  
+    **server-unavailable** (2),  
+    **unclassified-server-error** (3) **}**
+
+The TKServiceProblem shall be one of the following:
+
+- server-busy:** The DTAM-TK server is presently too busy to perform the requested abstract operation, but may be able after some shorter time period;
+- server-unavailable:** The DTAM-TK server is currently unavailable;
+- unclassified-server-error:** An error which cannot be categorized in any other way. The reason for this error is implementation specific.
+
+# Annex A
+
+## Formal assignment of object identifiers
+
+(This annex forms an integral part of this Recommendation)
+
+All object identifiers which are used in this Recommendation are formally assigned in this annex using the ASN.1 notation:
+
+```
+DTAM-MAN-ObjectIdentifiers { ccitt recommendation t 435 arch(3) modules(0) object-identifiers(0) }
+DEFINITIONS ::=
+BEGIN
+-- Prologue
+-- Exports everything
+-- Imports nothing
+
+ID ::= OBJECT IDENTIFIER
+    id-dtam-dm          ID ::= { ccitt recommendation t 435 dm(1) }    -- Document Manipulation
+    id-dtam-tk          ID ::= { ccitt recommendation t 435 tk(2) }    -- Token Handling
+    id-arch              ID ::= { ccitt recommendation t 435 arch(3)}  -- Overall Architecture
+
+-- Categories
+    id-mod              ID ::= { id-arch 0 }          -- modules
+
+-- Modules
+    id-object-identifiers ID ::= { id-mod 0 }
+
+END -- of DTAM-MAN-ObjectIdentifiers
+
+DTAM-DM-ObjectIdentifiers { ccitt recommendation t 435 dm(1) modules(0) object-identifiers(0) }
+DEFINITIONS ::=
+BEGIN
+-- EXPORTS everything
+IMPORTS
+    ID, id-dtam-dm
+    FROM DTAM-MAN-ObjectIdentifiers { ccitt recommendation t 435 arch(3) modules(0) object-identifiers(0) };
+
+-- Categories
+    id-mod              ID ::= { id-dtam-dm 0 }    -- modules
+    id-ot                ID ::= { id-dtam-dm 1 }    -- objects
+    id-pt                ID ::= { id-dtam-dm 2 }    -- ports
+
+-- Modules
+    id-mod-object-identifiers ID ::= { id-mod 0 }
+    id-mod-abstract-services ID ::= { id-mod 1 }
+
+-- Objects
+    id-ot-dtam-dm-client ID ::= { id-ot 0 }
+    id-ot-dtam-dm-server ID ::= { id-ot 1 }
+    id-ot-dtam-dm-dfr-client ID ::= { id-ot 2 }
+    id-ot-dtam-dm-dfr-server ID ::= { id-ot 3 }
+
+-- Ports
+    id-pt-dtam-dm-port ID ::= { id-pt 0 }
+    id-pt-dtam-dm-sym-port ID ::= { id-pt 1 }    -- only for DTAM-DM/TK environment
+
+END -- of DTAM-DM-ObjectIdentifiers
+```
+
+```
+
+DTAM-TK-ObjectIdentifiers { ccitt recommendation t 435 tk(2) modules(0) object-identifiers(0) }
+DEFINITIONS ::=
+BEGIN
+-- EXPORTS everything
+
+IMPORTS
+    ID, id-dtam-tk
+    FROM DTAM-MAN-ObjectIdentifiers { ccitt recommendation t 435 arch(3) modules(0) object-identifiers(0) };
+
+-- Categories
+
+    id-mod                ID ::= { id-dtam-tk 0 } -- modules
+    id-ot                  ID ::= { id-dtam-tk 1 } -- objects
+    id-pt                  ID ::= { id-dtam-tk 2 } -- ports
+
+-- Modules
+
+    id-mod-object-identifiers ID ::= { id-mod 0 }
+    id-mod-abstract-services ID ::= { id-mod 1 }
+
+-- Objects
+
+    id-ot-dtam-dm-tk-client-server ID ::= { id-ot 0 }
+
+-- Ports
+
+    id-pt-dtam-tk-port ID ::= { id-pt 0 }
+
+END -- of DTAM-TK-ObjectIdentifiers
+
+```
+
+# Annex B
+
+## Formal definition of DTAM-DM and DTAM-TK abstract services
+
+(This annex forms an integral part of this Recommendation)
+
+All abstract services which are used in this Recommendation are formally defined in this Annex B using the ASN.1 notation:
+
+```
+
+DTAM-DM-AbstractServices { ccitt recommendation t 435 dm(1) modules(0) abstract-services(1) }
+DEFINITIONS IMPLICIT TAGS ::=
+BEGIN
+-- EXPORTS everything
+
+IMPORTS
+    ABSTRACT-BIND, ABSTRACT-UNBIND, ABSTRACT-ERROR, ABSTRACT-OPERATION, OBJECT, PORT
+    FROM AbstractServiceNotation
+    { joint-iso-ccitt mhs-motis(6) asdc(2) modules(0) notation(1) }
+    -- see Recommendation X.407
+
+id-ot-dtam-dm-client, id-ot-dtam-dm-server,
+id-ot-dtam-dm-dfr-client, id-ot-dtam-dm-dfr-server,
+id-pt-dtam-dm-port
+
+    FROM DTAM-DM-ObjectIdentifiers
+    { ccitt recommendation t 435 dm(1) modules(0) object-identifiers(0) }
+
+Non-Basic-Doc-Characteristics, Non-Basic-Struc-Characteristics
+
+    FROM Document-Profile-Descriptor { 2 8 1 5 6 }
+
+```
+
+ConstituentType, AttributeValuesType, QueryType, ConstituentIdentifier
+
+FROM Abstract-Operations { 2 8 1 3 0 }  
+-- see Recommendation T.413
+
+Location-expression, Basic-location-expression, Constituent-locator
+
+FROM Location-Model { 2 8 1 12 0 }  
+-- see ITU-T Recommendation T.422
+
+DistinguishedName
+
+FROM InformationFramework  
+{ joint-iso-ccitt ds(5) modules(1) informationFramework(1) }
+
+Document-Reference
+
+FROM Document-Profile-Descriptor { 2 8 1 5 6 }  
+-- see Recommendation T.415
+
+DfrEntryName
+
+FROM DFRAbstractService { iso standard 10166 part-1(1) modules(0) abstract-service(1) };  
+-- see ISO/IEC 10166-1
+
+-- Objects
+
+dtam-dm-client OBJECT  
+PORTS { dtam-dm-port [ C ] }  
+::= id-ot-dtam-dm-client
+
+dtam-dm-server OBJECT  
+PORTS { dtam-dm-port [ S ] }  
+::= id-ot-dtam-dm-server
+
+dtam-dm-dfr-client OBJECT  
+PORTS { dtam-dm-port [ C ], dfr-port [ C ] }  
+::= id-ot-dtam-dm-dfr-client
+
+dtam-dm-dfr-server OBJECT  
+PORTS { dtam-dm-port [ S ], dfr-port [ S ] }  
+::= id-ot-dtam-dm-dfr-server
+
+-- Ports
+
+dtam-dm-port PORT  
+CONSUMER INVOKES  
+{  
+DM-DOCUMENT-OPEN,  
+DM-DOCUMENT-SAVE,  
+DM-DOCUMENT-DISCARD,  
+DM-DOCUMENT-CLOSE,  
+DM-DOCUMENT-LIST,  
+DM-GET,  
+DM-SEARCH,  
+DM-CREATE,  
+DM-DELETE,  
+DM-MODIFY,  
+DM-COPY,  
+DM-MOVE,  
+DM-REPLACE,  
+DM-RESERVE,  
+DM-UNRESERVE,  
+DM-POINT,  
+DM-MACRO-CALL,  
+DM-GROUP-BEGIN,  
+DM-GROUP-END  
+}  
+SUPPLIER INVOKES  
+{  
+}  
+::= id-pt-dtam-dm-port
+
+-- only in the DTAM-DM/DTAM-TK environment
+
+```
+dtam-dm-sym-port  PORT
+  ABSTRACT OPERATIONS {
+    DM-DOCUMENT-OPEN,
+    DM-DOCUMENT-SAVE,
+    DM-DOCUMENT-DISCARD,
+    DM-DOCUMENT-CLOSE,
+    DM-DOCUMENT-LIST,
+    DM-GET,
+    DM-SEARCH,
+    DM-CREATE,
+    DM-DELETE,
+    DM-MODIFY,
+    DM-COPY,
+    DM-MOVE,
+    DM-REPLACE,
+    DM-RESERVE,
+    DM-UNRESERVE,
+    DM-POINT,
+    DM-MACRO-CALL,
+    DM-GROUP-BEGIN,
+    DM-GROUP-END }
+  ::= id-pt-dtam-dm-sym-port
+```
+
+-- Data types
+
+```
+DocumentId ::= CHOICE {
+  dfrName           [0] DfrEntryName,
+  documentReference [1] Document-Reference,
+  documentName      [2] OCTET STRING,
+  nonPermanentIdentifier [3] NonPermanentIdentifier
+}
+
+ManipulationObject ::= SEQUENCE {
+  documentIdentifier [0] DocumentId OPTIONAL,
+  objectValue        [1] ObjectValue OPTIONAL
+}
+
+ObjectValue ::= CHOICE
+{
+  odaExpression [0] OdaExpression,
+  otherExpression [1] OCTET STRING,
+  anyExpression  [2] ANY
+}
+
+OdaExpression ::= CHOICE
+{
+  locationExpression [0] LocationExpression,
+  basicLocationexpression [1] BasicLocationExpression,
+  constituentLocator [2] ConstituentLocator,
+  ConstituentIdentifier [3] ConstituentIdentifier
+}
+
+ObjectPosition ::= ENUMERATED {
+  before (0),
+  afterLastChild (1)
+}
+
+ObjectContent ::= CHOICE {
+  odaContent [0] ConstituentType,
+  octetAligned [1] OCTET STRING,
+  anyContent  [2] ANY
+}
+
+AssignedId ::= CHOICE {
+  odaIdentifier [0] ConstituentIdentifier,
+  nonOdaIdentifier [1] INTEGER,
+  any [2] ANY
+}
+```
+
+```
+
+NonPermanentIdentifier ::= CHOICE
+{
+    [0] INTEGER,
+    [1] OCTET STRING
+}
+
+-- Abstract bind
+
+DTAM-DMBind ::= ABSTRACT-BIND
+TO {dtam-dm-port[S], dfr-port[S], dtam-dm-sym-port, dtam-tk-port} -- depending on the environment
+BIND
+    ARGUMENT    DtamDmBindArgument
+    RESULT       DtamDmBindResult
+    BIND-ERROR   DtamDmBindError
+
+DtamDmBindArgument ::= [0] SEQUENCE
+{
+    dtamProtocolVersion    [0] BIT STRING {
+                                version-1 (0)} DEFAULT {version-1},
+    dtamManipulationCapabilities [1] ManipulationCapabilities,
+    odaApplicationCapabilities [2] SEQUENCE OF OdaApplicationCapabilities OPTIONAL,
+    dfrCapabilities         [3] DfrCapabilities OPTIONAL,
+    bilateralInformation     [4] SEQUENCE OF BilateralInformation OPTIONAL,
+    applicationRequirements  [5] ApplicationRequirements OPTIONAL
+}
+
+OdaApplicationCapabilities ::= SEQUENCE
+{
+    odaDocumentApplicationProfile    [0] OBJECT IDENTIFIER,
+    nonBasicOdaDocumentCharacteristics [1] Non-Basic-Doc-Characteristics OPTIONAL,
+    nonBasicOdaStructuralCharacteristics [2] Non-Basic-Struc-Characteristics OPTIONAL
+}
+
+ManipulationCapabilities ::= CHOICE
+{
+    profileSelection    [0] OBJECT IDENTIFIER,
+    manipulationLevelSelection [1] ENUMERATED {
+        basicReadOnlyLevel    (0),
+        basicManipulationLevel (1),
+        extendedLevel         (2) },
+    bilateralAgreement  [2] IMPLICIT OCTET STRING }
+
+DfrCapabilities ::= SEQUENCE {
+    dfrProtocolVersion [0] DfrProtocolVersion DEFAULT {version-1},
+    dfrProfile          [1] OBJECT IDENTIFIER OPTIONAL }
+
+DfrProtocolVersion ::= BIT STRING
+{
+    version-1 (1),
+    version-2 (2)
+}
+
+BilateralInformation ::= SEQUENCE
+{
+    serverName    [0] ServerName,
+    information    [1] EXTERNAL
+}
+
+ServerName ::= DistinguishedName
+
+ApplicationRequirement ::= CHOICE
+{
+    [0] OCTET STRING,
+    [1] OBJECT IDENTIFIER
+}
+
+```
+
+**DtamDmBindResult ::= [1] SEQUENCE**
+
+```
+{
+    serverSelectedDtamProtocolVersion    [0] BIT STRING
+                                           { version-1 (0) } DEFAULT {version-1},
+    odaApplicationCapabilities           [1] SEQUENCE OF OdaApplicationCapabilities,
+    serverSelectedDfrVersion              [2] BIT STRING
+                                           { version-1 (1),
+                                             version-2 (2) } DEFAULT {version-1},
+    bilateralInformation                   [3] SEQUENCE OF BilateralInformation OPTIONAL }
+}
+```
+
+**DtamDmBindError ::= [2] CHOICE**
+
+```
+{
+    serviceError        [0] DmServiceProblem,
+    protocolError        [1] ProtocolProblem,
+    profileError         [2] ProfileProblem,
+    applicationError     [3] ApplicationProblem
+}
+```
+
+**ProtocolProblem ::= SEQUENCE**
+
+```
+{
+    protocol-version-not-supported    [0] SEQUENCE OF ENUMERATED {
+        dtam-version-not-supported (0),
+        dfr-version-not-supported (1) },
+    supportedDtamProtocolVersions     [1] BIT STRING {
+        version-1 (0) } OPTIONAL,
+    supportedDfrProtocolVersions      [2] BIT STRING {
+        version-1 (0),
+        version-2 (1) } OPTIONAL
+}
+```
+
+**ProfileProblem ::= SEQUENCE**
+
+```
+{
+    profile-not-supported             [0] SEQUENCE OF ENUMERATED {
+        dtam-manipulation-level-not-supported (0),
+        dfr-profile-not-supported (1) },
+    supportedDtamManipulationLevels   [1] SEQUENCE OF ManipulationCapabilities OPTIONAL,
+    supportedDfrProfiles               [2] SEQUENCE OF OBJECT IDENTIFIER OPTIONAL
+}
+```
+
+**ApplicationProblem ::= SEQUENCE OF ApplicationRequirements OPTIONAL**
+
+**DTAM-DMUnBind ::= ABSTRACT-UNBIND**
+
+**FROM** {dtam-dm-port[S], dfr-port[S], dtam-dm-sym-port, dtam-tk-port}  
+*-- depending on the environment*
+
+**DTAM-DMAbortInfo ::= [3] SEQUENCE**
+
+```
+{
+    abortSource        [0] DtamDmAbortSource,
+    abortReason         [1] DtamDmAbortReason OPTIONAL,
+    userInformation     [2] EXTERNAL OPTIONAL }
+}
+```
+
+**DtamDmAbortSource ::= ENUMERATED**
+
+```
+{
+    dtamDmServiceUser    (0),
+    dtamDmServiceProvider (1)
+}
+```
+
+**DtamDmAbortReason ::= ENUMERATED**
+
+```
+{
+    local-system-problem (0),
+    temporary-problem    (1),
+    protocol-error        (2)
+}
+```
+
+-- *Abstract operations*
+
+**DM-DOCUMENT-OPEN ::= ABSTRACT-OPERATION**
+
+|                          |                                   |
+|--------------------------|-----------------------------------|
+| <b>ARGUMENT</b>          | <b>DM-DOCUMENT-OPEN-Arguments</b> |
+| <b>RESULT</b>            | <b>DM-DOCUMENT-OPEN-Result</b>    |
+| <b>ERRORS {</b>          |                                   |
+| <b>DM-DocumentError,</b> |                                   |
+| <b>DM-AccessError,</b>   |                                   |
+| <b>DM-ServiceError</b>   |                                   |
+| <b>}</b>                 |                                   |
+
+**DM-DOCUMENT-OPEN-Arguments ::= SEQUENCE**
+
+{
+
+|                   |                              |
+|-------------------|------------------------------|
+| <b>documentId</b> | <b>[0] DocumentId</b>        |
+| <b>mode</b>       | <b>[1] ModeType OPTIONAL</b> |
+
+}
+
+**ModeType ::= ENUMERATED**
+
+{
+
+|               |             |
+|---------------|-------------|
+| <b>read</b>   | <b>(0),</b> |
+| <b>modify</b> | <b>(1),</b> |
+| <b>create</b> | <b>(2)</b>  |
+
+}
+
+**DM-DOCUMENT-OPEN-Result ::= CHOICE {**
+
+|                               |                                   |
+|-------------------------------|-----------------------------------|
+| <b>noValue</b>                | <b>[0] NULL,</b>                  |
+| <b>nonPermanentIdentifier</b> | <b>[1] NonPermanentIdentifier</b> |
+
+}
+
+**DM-DOCUMENT-SAVE ::= ABSTRACT-OPERATION**
+
+|                          |                                   |
+|--------------------------|-----------------------------------|
+| <b>ARGUMENT</b>          | <b>DM-DOCUMENT-SAVE-Arguments</b> |
+| <b>RESULT</b>            | <b>DM-DOCUMENT-SAVE-Result</b>    |
+| <b>ERRORS {</b>          |                                   |
+| <b>DM-AccessError,</b>   |                                   |
+| <b>DM-DocumentError,</b> |                                   |
+| <b>DM-ServiceError</b>   |                                   |
+| <b>}</b>                 |                                   |
+
+**DM-DOCUMENT-SAVE-Arguments ::= SEQUENCE**
+
+{
+
+|                   |                       |
+|-------------------|-----------------------|
+| <b>documentId</b> | <b>[0] DocumentId</b> |
+|-------------------|-----------------------|
+
+}
+
+**DM-DOCUMENT-SAVE-Result ::= NULL**
+
+**DM-DOCUMENT-DISCARD ::= ABSTRACT-OPERATION**
+
+|                          |                                      |
+|--------------------------|--------------------------------------|
+| <b>ARGUMENT</b>          | <b>DM-DOCUMENT-DISCARD-Arguments</b> |
+| <b>RESULT</b>            | <b>DM-DOCUMENT-DISCARD-Result</b>    |
+| <b>ERRORS {</b>          |                                      |
+| <b>DM-AccessError,</b>   |                                      |
+| <b>DM-DocumentError,</b> |                                      |
+| <b>DM-ServiceError</b>   |                                      |
+| <b>}</b>                 |                                      |
+
+**DM-DOCUMENT-DISCARD-Arguments ::= SEQUENCE**
+
+{
+
+|                   |                       |
+|-------------------|-----------------------|
+| <b>documentId</b> | <b>[0] DocumentId</b> |
+|-------------------|-----------------------|
+
+}
+
+**DM-DOCUMENT-DISCARD-Result ::= NULL**
+
+**DM-DOCUMENT-CLOSE ::= ABSTRACT-OPERATION**
+
+|                          |                                    |
+|--------------------------|------------------------------------|
+| <b>ARGUMENT</b>          | <b>DM-DOCUMENT-CLOSE-Arguments</b> |
+| <b>RESULT</b>            | <b>DM-DOCUMENT-CLOSE-Result</b>    |
+| <b>ERRORS {</b>          |                                    |
+| <b>DM-AccessError,</b>   |                                    |
+| <b>DM-DocumentError,</b> |                                    |
+| <b>DM-ServiceError</b>   |                                    |
+| <b>}</b>                 |                                    |
+
+```
+
+DM-DOCUMENT-CLOSE-Arguments ::= SEQUENCE
+{
+    documentId      [0] DocumentId
+}
+
+DM-DOCUMENT-CLOSE-Result ::= CHOICE
+{
+    noValue      NULL,
+    permanentId  [0] DocumentId
+}
+
+DM-DOCUMENT-LIST ::= ABSTRACT-OPERATION
+    ARGUMENT      DM-DOCUMENT-LIST-Arguments
+    RESULT         DM-DOCUMENT-LIST-Result
+    ERRORS
+    {
+        DM-ListError,
+        DM-ServiceError
+    }
+
+DM-DOCUMENT-LIST-Arguments ::= CHOICE
+{
+    odaCriteria      [0] QueryType,
+    otherCriteria    [1] OtherCriteria,
+    anyCriteria      [2] ANY
+}
+
+OtherCriteria ::= CHOICE {
+    all              [0] BOOLEAN,
+    prefix           [1] OCTET STRING,
+    suffix           [2] OCTET STRING }
+
+DM-DOCUMENT-LIST-Result ::= SEQUENCE OF DocumentId
+
+DM-GET ::= ABSTRACT-OPERATION
+    ARGUMENT      DM-GET-Arguments
+    RESULT         DM-GET-Result
+    ERRORS
+    {
+        DM-AccessError,
+        DM-FragmentError,
+        DM-DocumentError,
+        DM-ServiceError
+    }
+
+DM-GET-Arguments ::= SEQUENCE
+{
+    object      [0] ManipulationObject
+}
+
+DM-GET-Result ::= SEQUENCE OF SEQUENCE OF ObjectContent
+
+DM-SEARCH ::= ABSTRACT-OPERATION
+    ARGUMENT      DM-SEARCH-Arguments
+    RESULT         DM-SEARCH-Result
+    ERRORS
+    {
+        DM-AccessError,
+        DM-FragmentError,
+        DM-DocumentError,
+        DM-ServiceError
+    }
+
+DM-SEARCH-Arguments ::= SEQUENCE
+{
+    object      [0] ManipulationObject,
+    limit       [1] INTEGER OPTIONAL
+}
+
+```
+
+**DM-SEARCH-Result ::=SEQUENCE**
+
+```
+{
+    objectList          [0] SEQUENCE OF DocFragment-Id,
+    number              [1] INTEGER
+}
+```
+
+**DocFragment-Id ::= ObjectContent**
+
+**DM-CREATE ::= ABSTRACT-OPERATION**
+
+```
+ARGUMENT      DM-CREATE-Arguments
+RESULT        DM-CREATE-Result
+ERRORS
+{
+    DM-AccessError,
+    DM-FragmentError,
+    DM-DocumentError,
+    DM-AttributeError,
+    DM-UpdateError,
+    DM-ServiceError
+}
+```
+
+**DM-CREATE-Arguments ::= SEQUENCE**
+
+```
+{
+    destination        [0] ManipulationObject,
+    position            [1] ObjectPosition,
+    content             [2] SEQUENCE OF ObjectContent OPTIONAL
+}
+```
+
+**DM-CREATE-Result ::= CHOICE**
+
+```
+{
+    noValue            [0] NULL,
+    assignedID         [1] SEQUENCE OF AssignedId
+}
+```
+
+**DM-DELETE ::= ABSTRACT-OPERATION**
+
+```
+ARGUMENT      DM-DELETE-Arguments
+RESULT        DM-DELETE-Result
+ERRORS
+{
+    DM-AccessError,
+    DM-FragmentError,
+    DM-DocumentError,
+    DM-AttributeError,
+    DM-UpdateError,
+    DM-ServiceError
+}
+```
+
+**DM-DELETE-Arguments ::= SEQUENCE**
+
+```
+{
+    object            [0] ManipulationObject
+}
+```
+
+**DM-DELETE-Result ::= NULL**
+
+**DM-MODIFY ::= ABSTRACT-OPERATION**
+
+```
+ARGUMENT      DM-MODIFY-Arguments
+RESULT        DM-MODIFY-Result
+ERRORS
+{
+    DM-AccessError,
+    DM-DocumentError,
+    DM-FragmentError,
+    DM-AttributeError,
+    DM-UpdateError,
+    DM-ServiceError
+}
+```
+
+```
+
+DM-MODIFY-Arguments ::= SEQUENCE
+{
+    object                [0] ManipulationObject,
+    modifications         [1] ModificationsType
+}
+
+DM-MODIFY-Result ::= NULL
+
+ModificationsType ::= CHOICE
+{
+    odaModifications     [0] OdaModifications,
+    otherModifications    [1] OCTET STRING,
+    anyModifications     [2] ANY
+}
+
+OdaModifications ::= SEQUENCE
+{
+    attributeValue       [0] AttributeValuesType,
+    deleting             [1] BOOLEAN DEFAULT FALSE
+}
+
+DM-COPY ::= ABSTRACT-OPERATION
+    ARGUMENT          DM-COPY-Arguments
+    RESULT             DM-COPY-Result
+    ERRORS
+    {
+        DM-AccessError,
+        DM-DocumentError,
+        DM-FragmentError,
+        DM-AttributeError,
+        DM-UpdateError,
+        DM-ServiceError
+    }
+
+DM-COPY-Arguments ::= SEQUENCE
+{
+    source                [0] ManipulationObject OPTIONAL,
+    destination           [1] ManipulationObject OPTIONAL,
+    position               [2] ObjectPosition OPTIONAL
+}
+
+DM-COPY-Result ::= SEQUENCE
+{
+    newConstituent       [0] ManipulationObject
+}
+
+DM-MOVE ::= ABSTRACT-OPERATION
+    ARGUMENT          DM-MOVE-Arguments
+    RESULT             DM-MOVE-Result
+    ERRORS {
+        DM-AccessError,
+        DM-DocumentError,
+        DM-FragmentError,
+        DM-AttributeError,
+        DM-UpdateError,
+        DM-ServiceError
+    }
+
+DM-MOVE-Arguments ::= SEQUENCE
+{
+    source                [0] ManipulationObject,
+    destination           [1] ManipulationObject,
+    position               [2] ObjectPosition
+}
+
+```
+
+**DM-MOVE-Result ::= SEQUENCE**
+
+```
+{  
+    newConstituent      [0] ManipulationObject  
+}
+```
+
+**DM-REPLACE ::= ABSTRACT-OPERATION**
+
+```
+    ARGUMENT      DM-REPLACE-Arguments  
+    RESULT        DM-REPLACE-Result  
+    ERRORS  
+    {  
+        DM-AccessError,  
+        DM-DocumentError,  
+        DM-FragmentError,  
+        DM-AttributeError,  
+        DM-UpdateError,  
+        DM-ServiceError  
+    }
+```
+
+**DM-REPLACE-Arguments ::= SEQUENCE**
+
+```
+{  
+    object          [0] ManipulationObject,  
+    content         [1] ObjectContent  
+}
+```
+
+**DM-REPLACE-Result ::= NULL**
+
+**DM-RESERVE ::= ABSTRACT-OPERATION**
+
+```
+    ARGUMENT      DM-RESERVE-Arguments  
+    RESULT        DM-RESERVE-Result  
+    ERRORS  
+    {  
+        DM-AccessError,  
+        DM-DocumentError,  
+        DM-FragmentError,  
+        DM-ReservationError,  
+        DM-ServiceError  
+    }
+```
+
+**DM-RESERVE-Arguments ::= SEQUENCE**
+
+```
+{  
+    object          [0] ManipulationObject  
+}
+```
+
+**DM-RESERVE-Result ::= NULL**
+
+**DM-UNRESERVE ::= ABSTRACT-OPERATION**
+
+```
+    ARGUMENT      DM-UNRESERVE-Arguments  
+    RESULT        DM-UNRESERVE-Result  
+    ERRORS  
+    {  
+        DM-AccessError,  
+        DM-DocumentError,  
+        DM-FragmentError,  
+        DM-ReservationError,  
+        DM-ServiceError  
+    }
+```
+
+**DM-UNRESERVE-Arguments ::= SEQUENCE**
+
+```
+{  
+    object          [0] ManipulationObject  
+}
+```
+
+**DM-UNRESERVE-Result ::= NULL**
+
+**DM-POINT ::= ABSTRACT-OPERATION**
+
+|                 |                           |
+|-----------------|---------------------------|
+| <b>ARGUMENT</b> | <b>DM-POINT-Arguments</b> |
+| <b>RESULT</b>   | <b>DM-POINT-Result</b>    |
+| <b>ERRORS</b>   |                           |
+| {               |                           |
+|                 | <b>DM-AccessError,</b>    |
+|                 | <b>DM-DocumentError,</b>  |
+|                 | <b>DM-FragmentError,</b>  |
+|                 | <b>DM-ServiceError</b>    |
+| }               |                           |
+
+**DM-POINT-Arguments ::= SEQUENCE**
+
+{  
+     **object**            [0] **ManipulationObject**  
+ }
+
+**DM-POINT-Result ::= NULL**
+
+*-- Abstract errors*
+
+**DM-AccessError ::= ABSTRACT-ERROR**
+
+**PARAMETER CHOICE {**  
+     **docAccessError**            [0] **DocAccessError,**  
+     **fragAccessError**            [1] **FragAccessError }**
+
+**DocAccessError ::= SEQUENCE {**  
+     **documentId**                [0] **DocumentId,**  
+     **dmDocAccProblem**            [1] **DmDocAccProblem }**
+
+**DmDocAccProblem ::= ENUMERATED {**  
+     **document-already-open**        (1),  
+     **document-not-opened**         (2),  
+     **improper-access-rights**       (3) }
+
+**FragAccessError ::= SEQUENCE {**  
+     **entry**                        [0] **ManipulationObject,**  
+     **dmFragAccProblem**            [1] **DmFragAccProblem }**
+
+**DmFragAccProblem ::= ENUMERATED {**  
+     **reserved-by-a-user**           (1),  
+     **improper-access-rights**       (2) }
+
+**DM-AttributeError ::= ABSTRACT-ERROR**
+
+**PARAMETER SEQUENCE {**  
+     **entry**        [0] **ManipulationObject,**  
+     **problems** [1] **SEQUENCE OF SEQUENCE {**  
+         **problem** [0] **DmAttributeProblem,**  
+         **type**     [1] **TypeOfAttributeValue OPTIONAL } }**
+
+**DmAttributeProblem ::= ENUMERATED {**  
+     **invalid-syntax**                (1),  
+     **constraint-violation**          (2),  
+     **illegal-violation**              (3) }
+
+**TypeOfAttributeValue ::= CHOICE {**  
+     **odaAttributeValue**            [0] **AttributeValuesType,**  
+     **anyAttributeValue**            [1] **ANY }**
+
+**DM-UpdateError ::= ABSTRACT-ERROR**
+
+**PARAMETER SEQUENCE {**  
+     **entry**                        [0] **ManipulationObject,**  
+     **problem**                      [1] **DmUpdateProblem }**
+
+**DmUpdateProblem ::= ENUMERATED { illegal-modification        (1) }**
+
+```
+
+DM-DocumentError ::= ABSTRACT-ERROR
+PARAMETER SEQUENCE {
+    entry          [0] DocumentId,
+    problem        [1] DmDocumentProblem }
+
+DmDocumentProblem ::= ENUMERATED {
+    invalid-upi          (1),
+    invalid-path-name    (2),
+    ambiguous-path-name  (3),
+    invalid-document-reference (4),
+    invalid-document-name (5),
+    invalid-non-permanent-id (6) }
+
+DM-FragmentError ::= ABSTRACT-ERROR
+PARAMETER SEQUENCE {
+    entry          [0] ObjectValue,
+    problem        [1] DmFragmentProblem }
+
+DmFragmentProblem ::= ENUMERATED {
+    invalid-location-expression (1),
+    invalid-expression          (2) }
+
+DM-ListError ::= ABSTRACT-ERROR
+PARAMETER ListProblem
+
+ListProblem ::= CHOICE {
+    all          [0] BOOLEAN,
+    prefix       [1] OCTET STRING,
+    suffix       [2] OCTET STRING,
+    typeOfQuery  [3] QueryType,
+    anyCriteria  [4] ANY }
+
+DM-ReserveError ::= ABSTRACT-ERROR
+PARAMETER SEQUENCE {
+    entry          [0] ManipulationObject,
+    problem        [1] DmReservationProblem }
+
+DmReservationProblem ::= ENUMERATED {
+    already-reserved (1),
+    not-yet-reserved (2) }
+
+DM-ServiceError ::= ABSTRACT-ERROR
+PARAMETER DmServiceProblem
+
+DmServiceProblem ::= ENUMERATED
+{
+    server-busy          (1),
+    server-unavailable    (2),
+    resource-limit-exceeded (3),
+    operation-too-complex (4),
+    unclassified-server-error (5)
+}
+
+END -- of DTAM-DM-AbstractServices
+
+DTAM-TK-AbstractServices { ccitt recommendation t 435 tk(2) modules(0) abstract-services(1) }
+DEFINITIONS IMPLICIT TAGS ::=
+BEGIN
+-- EXPORTS everything
+
+IMPORTS
+
+    ABSTRACT-ERROR, ABSTRACT-OPERATION, OBJECT, PORT
+
+    FROM AbstractServiceNotation
+    { joint-iso-ccitt mhs-motis(6) asdc(2) modules(0) notation(1) }
+
+```
+
+**id-pt-dtam-dm-sym-port**
+
+```
+FROM DTAM-DM-AbstractServices
+{ ccitt recommendation t 435 dm(1) modules(0) abstract-services(1) }
+```
+
+**id-pt-dtam-tk-port,**
+
+**id-ot-dtam-dm-tk-client-server**
+
+```
+FROM DTAM-TK-ObjectIdentifiers
+{ ccitt recommendation t 435 tk(2) modules(0) object-identifiers(0) };
+```
+
+*-- Objects*
+
+```
+dtam-dm-tk-client-server    OBJECT
+                            PORTS { dtam-dm-sym-port, dtam-tk-port }
+                            ::= id-ot-dtam-dm-tk-client-server
+```
+
+*-- Ports*
+
+```
+dtam-tk-port    PORT
+ABSTRACT OPERATIONS {
+    TK-TOKEN-GIVE,
+    TK-TOKEN-PLEASE }
+::= id-pt-dtam-tk-port
+```
+
+*-- Abstract operations*
+
+```
+TK-TOKEN-GIVE ::= ABSTRACT-OPERATION
+    ARGUMENT      TK-TOKEN-GIVE-Arguments
+    RESULT         TK-TOKEN-GIVE-Result
+    ERRORS
+    {
+        TK-ServiceError
+    }
+```
+
+**TK-TOKEN-GIVE-Arguments ::= NULL**
+
+**TK-TOKEN-GIVE-Result ::= NULL**
+
+```
+TK-TOKEN-PLEASE ::= ABSTRACT-OPERATION
+    ARGUMENT      TK-TOKEN-PLEASE-Arguments
+    RESULT         TK-TOKEN-PLEASE-Result
+    ERRORS
+    {
+        TK-ServiceError
+    }
+```
+
+**TK-TOKEN-PLEASE-Arguments ::= NULL**
+
+**TK-TOKEN-PLEASE-Result ::= NULL**
+
+*-- Abstract errors*
+
+```
+TK-ServiceError ::= ABSTRACT-ERROR
+    PARAMETER TKServiceProblem
+```
+
+```
+TKServiceProblem ::= ENUMERATED {
+    server-busy           (1),
+    server-unavailable    (2),
+    unclassified-server-error (3) }
+```
+
+**END -- of DTAM-TK-AbstractServices**
+
+# **Appendix I**
+
+## **Basic procedures for the use of DTAM-DM abstract services**
+
+(This appendix does not form an integral part of this Recommendation)
+
+The following basic procedures are considered for the use of the DTAM-DM abstract services:
+
+### **I.1 DTAM association establishment**
+
+The DTAM-DM client creates a DTAM association to the DTAM-DM server using the ACSE A-ASSOCIATE service to establish a communication link. During this establishment, the DTAM server exchanges its application capabilities including the manipulation capabilities. These capabilities indicated from the server are interpreted as the server's receiving capabilities, and are not recognized as capability negotiation.
+
+### **I.2 Document open**
+
+Before manipulating document fragments of a document, the DTAM-DM client must open the document using the document open abstract service. The DTAM-DM client can open more than one document within a DTAM association.
+
+### **I.3 Document manipulations**
+
+The DTAM-DM client can manipulate document fragments of documents which have been opened before using convenient DM-\* abstract services. Furthermore, the DTAM-DM client can manipulate among more than one document, e.g. copying a part of one document into another document.
+
+### **I.4 Document save**
+
+After a sequence of document fragment manipulations, the DTAM-DM client can save this document(s) to register the result of this sequence of manipulations.
+
+### **I.5 Document discard**
+
+After a sequence of document fragment manipulations, the DTAM-DM client can undo this sequence of manipulations using the document discard service. All manipulations are discarded until the previous document save operation.
+
+### **I.6 Document close**
+
+After the manipulation of the document fragments, the DTAM-DM client closes the document.
+
+### **I.7 DTAM association termination**
+
+After all the activities for document manipulations, the DTAM-DM client terminates the association using the ACSE A-RELEASE service to close the communication link between the DTAM users.
+
+Figure I.1 illustrates an example for the use of DTAM-DM abstract services.
+
+![Sequence diagram showing DTAM-DM client and server interactions. The diagram is divided into sections: Synchronous (A-ASSOCIATE req./res., DM-DOC-OPEN req./res.), Asynchronous (DTAM-DM operations), Synchronous (DM-DOC-SAVE req./res.), Asynchronous (DTAM-DM operations), and Synchronous (DM-DOC-CLOSE req./res.). A legend at the bottom left defines 'req.' as request and 'res.' as result. A reference code 'T0818010-94/d05' is at the bottom right.](5a9cdc1fed33ae8fb871a8cd4d591729_img.jpg)
+
+DTAM-DM client
+
+DTAM-DM server
+
+Time
+
+A-ASSOCIATE req.
+
+A-ASSOCIATE res.
+
+DM-DOC-OPEN req.
+
+DM-DOC-OPEN res.
+
+DTAM-DM operations
+
+DM-DOC-SAVE req.
+
+DM-DOC-SAVE res.
+
+DTAM-DM operations
+
+DM-DOC-CLOSE req.
+
+DM-DOC-CLOSE res.
+
+req. request
+
+res. result
+
+T0818010-94/d05
+
+Sequence diagram showing DTAM-DM client and server interactions. The diagram is divided into sections: Synchronous (A-ASSOCIATE req./res., DM-DOC-OPEN req./res.), Asynchronous (DTAM-DM operations), Synchronous (DM-DOC-SAVE req./res.), Asynchronous (DTAM-DM operations), and Synchronous (DM-DOC-CLOSE req./res.). A legend at the bottom left defines 'req.' as request and 'res.' as result. A reference code 'T0818010-94/d05' is at the bottom right.
+
+NOTE – The only operations that are asynchronously invoked and results return asynchronously as well, are the operations contained in the DTAM-DM confirmed document manipulation functional unit.
+
+FIGURE I.1/T.435  
+Example for the use of DTAM-DM abstract services
+
+# **Appendix II**
+
+## **Basic procedures for the combined use of DTAM-DM and DFR abstract services**
+
+(This appendix does not form an integral part of this Recommendation)
+
+The configuration for combined use of DTAM-DM and DFR constitutes a client-server system. The DTAM-DM/DFR client makes use of both DTAM-DM and DFR abstract services while the DTAM-DM/DFR server provides both DTAM-DM and DFR abstract services.
+
+The following procedures are applied to the combined use of DTAM-DM and DFR abstract services:
+
+### **II.1 DTAM-DM/DFR association establishment**
+
+The DTAM-DM/DFR client creates a DTAM-DM/DFR association to the DTAM-DM/DFR server by the ACSE A-ASSOCIATE service. Subsets of DTAM-DM and DFR services may be used as agreed during association establishment. During this establishment, the DTAM-DM/DFR client and DTAM-DM/DFR server also have to agree on their application capabilities including manipulation of document fragments.
+
+### **II.2 Document filing and retrieval (use of DFR abstract services)**
+
+After DTAM-DM/DFR association establishment the DTAM-DM/DFR client can use any DFR abstract service, for example to browse, retrieve, manage or delete documents in the document store.
+
+The DTAM-DM/DFR client selects a document using a DFR service and obtains a document identification. Before manipulating the document, the DTAM-DM/DFR client should modify the access rights of the entire document for other DTAM-DM/DFR clients, using the DFR reserve service, in order to prevent other DTAM-DM/DFR clients to access the document.
+
+### **II.3 Document manipulation (use of DTAM-DM-abstract services)**
+
+Before manipulating document fragments, the DTAM-DM/DFR client opens the document. The DTAM-DM/DFR client is able to manipulate fragments of more than one document.
+
+The DTAM-DM/DFR client uses the DTAM-DM abstract services to manipulate the document fragments remotely. For more details about DTAM-DM abstract services, see Appendix I.
+
+During document manipulation, the DTAM-DM/DFR client can use all convenient DFR abstract services.
+
+Upon completion of all document manipulation operations, the DTAM-DM/DFR client closes the document and then unreserves the document using the DFR reserve service in order to allow other DTAM-DM/DFR clients to access the document.
+
+### **II.4 DTAM-DM/DFR association termination**
+
+After all the activities for document filing, retrieval and manipulation the DTAM-DM/DFR client terminates the DTAM-DM/DFR association using the ACSE A-RELEASE service to close the communication link between the DTAM-DM/DFR client and the DTAM-DM/DFR server.
+
+Figure II.1 illustrates an example for the combined use of DTAM-DM and DFR abstract services.
+
+![Sequence diagram showing the combined use of DTAM-DM and DFR abstract services over time. The diagram illustrates the lifecycle of documents and fragments, including opening, creating, searching, copying, deleting, and closing, as well as association establishment and termination.](352d21d1e740e4a58cb17ab8656cfad8_img.jpg)
+
+The diagram illustrates the combined use of DTAM-DM and DFR abstract services over time. A vertical bar on the left represents the progression of time, with a downward arrow labeled "Time".
+
+The sequence of events is as follows:
+
+- DTAM-DM/DFR association establishment (ACSE A-ASSOCIATE service)**: The initial setup of the association.
+- Open document (DTAM-DM open service)**: Document 1 is opened.
+- Create document fragment(s) [DTAM-DM create service(s)]**: Fragment 1 is created within Document 1.
+- Search document (DFR search service)**: Document 2 is searched.
+- Open document (DTAM-DM open service)**: Document 2 is opened.
+- Search document fragment (DTAM-DM search service)**: Fragment 1 is searched within Document 2.
+- Copy document fragment (DTAM-DM copy service)**: Fragment 1 is copied from Document 2.
+- Delete document fragment (DTAM-DM delete service)**: Fragment 2 is deleted from Document 2.
+- Close document (DTAM-DM close service)**: Document 2 is closed.
+- Close document (DTAM-DM close service)**: Document 1 is closed.
+- Copy document DFR copy service)**: Document 3 is created from a copy of Document 1.
+- Delete document (DFR delete service)**: Document 2 is deleted.
+- DTAM-DM/DFR association termination (ACSE A-RELEASE service)**: The association is terminated.
+
+The diagram shows the state of documents and fragments at various points in time. Document 1 is initially open, then closed. Document 2 is opened, searched, and then closed. Document 3 is created and then deleted. Fragment 1 is created, searched, and copied. Fragment 2 is deleted.
+
+Sequence diagram showing the combined use of DTAM-DM and DFR abstract services over time. The diagram illustrates the lifecycle of documents and fragments, including opening, creating, searching, copying, deleting, and closing, as well as association establishment and termination.
+
+T0820030-94/d06
+
+FIGURE II.1/T.435  
+Example for the combined use of DTAM-DM and DFR abstract services
\ No newline at end of file
diff --git a/marked/T/T-REC-T.436-199508-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/T/T-REC-T.436-199508-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..685c8e617498ee202953bbb7377b78c5bb1a9ce3
--- /dev/null
+++ b/marked/T/T-REC-T.436-199508-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:96a2e57f95087f42a659afc90e2a8717f79f30474ba79318bf4b8450fc93ed8b
+size 8407
diff --git a/marked/T/T-REC-T.436-199508-I_PDF-E/6df5629bc2fc6d82f1a1edf9d7340113_img.jpg b/marked/T/T-REC-T.436-199508-I_PDF-E/6df5629bc2fc6d82f1a1edf9d7340113_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..2da868344f30c5333db2d25476bcbbc4f5adf00f
--- /dev/null
+++ b/marked/T/T-REC-T.436-199508-I_PDF-E/6df5629bc2fc6d82f1a1edf9d7340113_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:d2eef93e44b2c6a50cdadf32dfae0c573a3b1594ef97a2cb02fa367b10374167
+size 77996
diff --git a/marked/T/T-REC-T.436-199508-I_PDF-E/997233d405f0d4b89ddeb7683e047f66_img.jpg b/marked/T/T-REC-T.436-199508-I_PDF-E/997233d405f0d4b89ddeb7683e047f66_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..1661e41fc29af18999c5a648a34c6ca493f335be
--- /dev/null
+++ b/marked/T/T-REC-T.436-199508-I_PDF-E/997233d405f0d4b89ddeb7683e047f66_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:6d635117edd5cb91e9a095e1a3ed60aefb537c5a76c06fccb34fe280ae19aacd
+size 47115
diff --git a/marked/T/T-REC-T.436-199508-I_PDF-E/raw.md b/marked/T/T-REC-T.436-199508-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..30b831ef81323a14cadc25698df9169b813b290d
--- /dev/null
+++ b/marked/T/T-REC-T.436-199508-I_PDF-E/raw.md
@@ -0,0 +1,587 @@
+
+
+![ITU logo: a globe with the letters ITU inside, crossed by a lightning bolt.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg)
+
+ITU logo: a globe with the letters ITU inside, crossed by a lightning bolt.
+
+INTERNATIONAL TELECOMMUNICATION UNION
+
+**ITU-T**
+
+TELECOMMUNICATION  
+STANDARDIZATION  
+OF ITU
+
+**T.436**
+
+(08/95)
+
+**TERMINALS FOR TELEMATIC SERVICES**
+
+---
+
+**DOCUMENT TRANSFER AND MANIPULATION  
+(DTAM) – SERVICES AND PROTOCOLS –  
+PROTOCOL SPECIFICATIONS FOR  
+CONFIRMED DOCUMENT MANIPULATION**
+
+**ITU-T Recommendation T.436**
+
+(Previously “CCITT Recommendation”)
+
+---
+
+# FOREWORD
+
+The ITU-T (Telecommunication Standardization Sector) is a permanent organ of the International Telecommunication Union (ITU). The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis.
+
+The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics.
+
+The approval of Recommendations by the Members of the ITU-T is covered by the procedure laid down in WTSC Resolution No. 1 (Helsinki, March 1-12, 1993).
+
+ITU-T Recommendation T.436 was prepared by ITU-T Study Group 8 (1993-1996) and was approved under the WTSC Resolution No. 1 procedure on the 11th of August 1995.
+
+# --- NOTE
+
+In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+© ITU 1996
+
+All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU.
+
+# CONTENTS
+
+*Page*
+
+|   |                                                                     |   |
+|---|---------------------------------------------------------------------|---|
+| 1 | Scope .....                                                         | 1 |
+| 2 | References .....                                                    | 1 |
+| 3 | Definitions .....                                                   | 1 |
+| 4 | Abbreviations .....                                                 | 1 |
+| 5 | Conventions .....                                                   | 2 |
+| 6 | Overview of the protocol specifications .....                       | 2 |
+|   | 6.1 The protocol model .....                                        | 2 |
+|   | 6.2 Refinement of the TPA model .....                               | 3 |
+|   | 6.3 Abstract services provided by the DTAM-DM service element ..... | 3 |
+|   | 6.4 Abstract services provided by the DTAM-TK service element ..... | 4 |
+| 7 | Formal protocol specifications .....                                | 4 |
+|   | 7.1 Formal specification of the DTAM-DM protocol .....              | 4 |
+|   | 7.2 Formal specification of the DTAM-TK protocol .....              | 6 |
+|   | 7.3 Definition of abstract syntax for DTAM-DM .....                 | 7 |
+|   | 7.4 Definition of abstract syntax for DTAM-TK .....                 | 8 |
+| 8 | Conformance .....                                                   | 8 |
+|   | 8.1 Conformance to the DTAM-DM protocol .....                       | 8 |
+|   | 8.2 Conformance to the DTAM-TK protocol .....                       | 8 |
+|   | Annex A – Formal assignment of object identifiers .....             | 9 |
+
+# **SUMMARY**
+
+This Recommendation defines the communication protocol for document remote access, presentation, editing and transfer. It defines the protocol of two new applications service elements for interactive confirmed document manipulation, aligned with, and provided for, the integrated use with applications defined under the Distributed Office Application Model (DOAM). The two application service elements are the DTAM-TM and DTAM-TK. The use of the DTAM-DM application service element is mandatory for document manipulation applications and is used in conjunction with the ACSE and ROSE services elements. Optionally, it may be combined with the DFR-SE (for filing and retrieval purposes) and with the DTAM-TK service element for exchange of an application token in multi-user conferences.
+
+# DOCUMENT TRANSFER AND MANIPULATION (DTAM) – SERVICES AND PROTOCOLS – PROTOCOL SPECIFICATIONS FOR CONFIRMED DOCUMENT MANIPULATION
+
+(Geneva, 1995)
+
+# 1 Scope
+
+Recommendation T.435 defines the abstract services of the application service elements DTAM-DM and DTAM-TK.
+
+The DTAM-DM abstract services provide facilities to allow remote operations on any kind of documents or document fragments.
+
+The DTAM-TK application service element provides for the handling of an application token to structure a dialogue, if two or more users are involved in conference type of applications.
+
+This Recommendation specifies the protocols between DTAM users which apply the DTAM-DM or the DTAM-TK abstract services.
+
+This Recommendation does not specify individual implementations or products, nor does it contain the implementation of entities or interfaces within a telematic system.
+
+# 2 References
+
+The following Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication the editions indicated were valid. All Recommendations and other references are subject to revision; all users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published.
+
+- ITU-T Recommendation T.435 (1995), *Document Transfer And Manipulation (DTAM) – Services and protocols – Abstract service definition and procedures for confirmed document manipulation.*
+
+The references listed in Recommendation T.435 apply also to this Recommendation.
+
+# 3 Definitions
+
+The definitions given in Recommendation T.435 apply also to this Recommendation.
+
+Additionally, the following definitions are used in this Recommendation.
+
+- 3.1 DTAM-DM user:** DTAM-DM client or DTAM-DM server.
+- 3.2 DTAM-TK user:** DTAM-TK client or DTAM-TK server.
+- 3.3 DTAM client:** DTAM-DM client or DTAM-TK client.
+- 3.4 DTAM server:** DTAM-DM server or DTAM-TK server.
+- 3.5 DTAM user:** DTAM client or DTAM server.
+
+# 4 Abbreviations
+
+The abbreviations defined in Recommendation T.435 apply also to this Recommendation.
+
+Additionally, the following abbreviations are used in this Recommendation.
+
+|            |                                               |
+|------------|-----------------------------------------------|
+| ACSE       | Association Control Service Element           |
+| DFR-SE     | Document Filing and Retrieval Service Element |
+| DTAM-DM-SE | DTAM-DM Service Element                       |
+| DTAM-TK-SE | DTAM-TK Service Element                       |
+| ROSE       | Remote Operation Service Element              |
+
+# 5 Conventions
+
+The conventions described in Recommendation T.435 apply also to this Recommendation.
+
+# 6 Overview of the protocol specifications
+
+This clause provides an introduction to the protocol model, its addition to the Telematic Protocol Architecture (TPA) and the DTAM-DM and DTAM- TK protocol specifications. The formal specification of the protocols is given in clause 7: “Formal specification of protocols”.
+
+## 6.1 The protocol model
+
+Figure 1 illustrates the model for communication applications based on this Recommendation.
+
+![Figure 1: The protocol model. This diagram illustrates the communication model between a DTAM client and a DTAM server. At the top, a legend indicates that boxes with a single border are 'Mandatory' and boxes with a double border are 'Optional'. The 'Application layer' contains two main components: the 'DTAM client' and the 'DTAM server'. Each component contains a vertical stack of service elements: DTAM-DM-SE (mandatory), DTAM-TK-SE (optional), DFR-SE (optional), ROSE (mandatory), and ACSE (mandatory). Between the client and server, two protocols are shown: the 'T.436 Protocol' (mandatory) and the 'DFR Protocol' (optional). At the bottom, the 'Presentation layer' is shown, with a 'Presentation connection' line connecting the ACSE elements of both the client and server. The reference 'T0820040-94/d01' is located in the bottom right corner.](6df5629bc2fc6d82f1a1edf9d7340113_img.jpg)
+
+Figure 1: The protocol model. This diagram illustrates the communication model between a DTAM client and a DTAM server. At the top, a legend indicates that boxes with a single border are 'Mandatory' and boxes with a double border are 'Optional'. The 'Application layer' contains two main components: the 'DTAM client' and the 'DTAM server'. Each component contains a vertical stack of service elements: DTAM-DM-SE (mandatory), DTAM-TK-SE (optional), DFR-SE (optional), ROSE (mandatory), and ACSE (mandatory). Between the client and server, two protocols are shown: the 'T.436 Protocol' (mandatory) and the 'DFR Protocol' (optional). At the bottom, the 'Presentation layer' is shown, with a 'Presentation connection' line connecting the ACSE elements of both the client and server. The reference 'T0820040-94/d01' is located in the bottom right corner.
+
+FIGURE 1/T.436
+
+### The protocol model
+
+The protocol model comprises the DTAM-DM, DTAM-TK, DFR, RO and AC application service elements. The DTAM-TK and DFR application service elements are used optionally.
+
+## 6.2 Refinement of the TPA model
+
+The Telematic Protocol Architecture (TPA) model is described in Recommendation T.431 and illustrated in Figure 1/T.431.
+
+This Recommendation provides a refinement of the TPA model for communication applications based on this Recommendation. Figure 2 gives an overview.
+
+![Diagram of the Refinement of the TPA model showing the hierarchy of service elements.](997233d405f0d4b89ddeb7683e047f66_img.jpg)
+
+The diagram illustrates the refinement of the TPA model. It shows a hierarchy of service elements within a large rectangular frame. At the top level, three boxes are arranged horizontally: 'DTAM-DM-SE' on the left, 'DTAM-TK-SE' in the middle, and 'DFR-SE' on the right. Below these, a single wide box labeled 'ROSE' spans the width of the three boxes above it. To the left of the 'ROSE' box is another box labeled 'ACSE'. Below the 'ROSE' and 'ACSE' boxes is a single wide box labeled 'Presentation'. A vertical line extends from the bottom center of the 'Presentation' box to the text 'Underlying services' located below the main frame. In the bottom right corner of the frame, the text 'T0820050-94/d02' is present.
+
+Diagram of the Refinement of the TPA model showing the hierarchy of service elements.
+
+FIGURE 2/T.436
+
+### Refinement of the TPA model
+
+The DTAM-DM application service element makes use of the remote operations which are provided by ROSE.
+
+DTAM-TK and DFR are used optionally and are both ROSE-based.
+
+All application service elements make use of the presentation service.
+
+## 6.3 Abstract services provided by the DTAM-DM service element
+
+The DTAM-DM service element provides the following DTAM-DM abstract services:
+
+- DM-DOCUMENT-OPEN;
+- DM-DOCUMENT-SAVE;
+- DM-DOCUMENT-DISCARD;
+- DM-DOCUMENT-CLOSE;
+- DM-DOCUMENT-LIST;
+- DM-GET;
+- DM-SEARCH;
+- DM-CREATE;
+- DM-DELETE;
+- DM-MODIFY;
+- DM-COPY;
+- DM-MOVE;
+- DM-REPLACE;
+- DM-RESERVE;
+- DM-UNRESERVE;
+
+- DM-POINT;
+- DM-MACRO-CALL;
+- DM-GROUP-BEGIN;
+- DM-GROUP-END.
+
+## 6.4 Abstract services provided by the DTAM-TK service element
+
+The DTAM-TK service element provides the following DTAM-TK abstract services:
+
+- TK-TOKEN-GIVE;
+- TK-TOKEN-PLEASE.
+
+# 7 Formal protocol specifications
+
+This clause provides the formal specification for the DTAM-DM and DTAM-TK protocols.
+
+## 7.1 Formal specification of the DTAM-DM protocol
+
+The protocol is described in terms of DTAM-DM data units exchanged between the peer DTAM-DM-SEs. The PDUs are specified using ASN.1 and the Remote operations OPERATION and ERROR external macros defined in Recommendation X.219.
+
+```
+-- DTAM-DM protocol
+DTAM-DM-Protocol { ccitt recommendation t 436 modules(0) dm-protocol(1) }
+DEFINITIONS ::= BEGIN
+EXPORTS
+
+-- DTAM-DM SE
+    dTAM-DM-SE;
+IMPORTS
+
+-- Application service elements and application contexts
+    APPLICATION-SERVICE-ELEMENT, APPLICATION-CONTEXT,
+    aCSE, rOSE
+        FROM Remote-Operation-Notation-extension
+        { joint-iso-ccitt remote-operation(4) notation-extension(2) }
+
+    dFRSE
+        FROM DFRAccessProtocol
+        { iso standard 10166 part-2(2) modules(0) access-protocol(1) }
+
+-- DTAM-DM abstract services
+    DM-DOCUMENT-OPEN, DM-DOCUMENT-SAVE, DM-DOCUMENT-DISCARD,
+    DM-DOCUMENT-CLOSE, DM-DOCUMENT-LIST,
+    DM-GET, DM-SEARCH,
+    DM-CREATE, DM-DELETE, DM-MODIFY, DM-COPY,
+    DM-MOVE, DM-REPLACE, DM-RESERVE, DM-UNRESERVE, DM-POINT,
+    DM-MACRO-CALL, DM-GROUP-BEGIN, DM-GROUP-END,
+
+-- DTAM-DM abstract errors
+    DM-DocumentError,
+    DM-AccessError,
+    DM-ReservationError,
+    DM-FragmentError,
+    DM-SaveError,
+    DM-ServiceError,
+    DM-ContentError,
+    DM-AttributeError,
+    DM-ListError
+
+        FROM DTAM-DM-AbstractServices
+        { ccitt recommendation t 435 dm(1) modules(0) abstract-services(1) }
+```
+
+```
+
+-- DTAM-DM object identifiers
+    id-ase-dtam-dm, id-ase-dtam-tk,
+    id-as-dtam-dm, id-as-dtam-tk
+        FROM DTAM-DM-TK-ProtocolObjectIdentifiers
+        { ccitt recommendation t 436 modules(0) object-identifiers(0) }
+
+-- DFR object identifiers
+    id-as-acse, id-as-dfrse, id-as-dfr-ext-attr
+        FROM DFRProtocolObjectIdentifiers
+        { iso standard 10166 part-2(2) modules(0) object-identifiers(0) };
+
+-- DTAM-DM application context
+dtam-dm    APPLICATION-CONTEXT
+            APPLICATION SERVICE ELEMENTS
+                { aCSE }
+            BIND DtamBind
+            UNBIND DtamUnbind
+            REMOTE OPERATIONS { rOSE }
+            INITIATOR CONSUMER OF { dTAM-DM-SE }
+            ABSTRACT SYNTAXES
+            {
+                id-as-acse,          -- of ACSE
+                id-as-dtam-dm,       -- of DTAM-DM-SE
+            }
+            ::= id-ac-dtam-dm
+
+-- DTAM-DM/DTAM-TK combined application context
+dtam-dm-tk    APPLICATION-CONTEXT
+                APPLICATION SERVICE ELEMENTS
+                    { aCSE }
+                BIND DtamBind
+                UNBIND DtamUnbind
+                REMOTE OPERATIONS {rOSE}
+                OPERATIONS OF { dTAM-DM-SE, dTAM-TK-SE }
+                ABSTRACT SYNTAXES
+                {
+                    id-as-acse,          -- of ACSE
+                    id-as-dtam-dm,       -- of DTAM-DM-SE
+                    id-as-dtam-tk       -- of DTAM-TK-SE
+                }
+                ::= id-ac-dtam-dm-tk
+
+-- DTAM-DM/DFR combined application context
+dtam-dm-dfr    APPLICATION-CONTEXT
+                APPLICATION SERVICE ELEMENTS
+                    { aCSE }
+                BIND DtamBind
+                UNBIND DtamUnbind
+                REMOTE OPERATIONS { rOSE }
+                INITIATOR CONSUMER OF { dTAM-DM-SE, dFRSE }
+                ABSTRACT SYNTAXES
+                {
+                    id-as-acse,          -- of ACSE
+                    id-as-dtam-dm,       -- of DTAM-DM-SE
+                    id-as-dfrse,         -- of DFR-SE
+                    id-as-dfr-ext-attr   -- of DFR extension attribute set
+                }
+                ::= id-ac-dtam-dm-dfr
+
+-- DTAM-DM service element
+    dTAM-DM-SE    APPLICATION-SERVICE-ELEMENT
+                  CONSUMER INVOKES
+                  {
+                      dm-document-open,
+                      dm-document-save,
+                      dm-document-discard,
+                      dm-document-close,
+                      dm-document-list,
+
+```
+
+```
+
+        dm-get,
+        dm-search,
+        dm-create,
+        dm-delete,
+        dm-modify,
+        dm-copy,
+        dm-move,
+        dm-replace,
+        dm-reserve,
+        dm-unreserve,
+        dm-point,
+        dm-macro-call,
+        dm-group-begin,
+        dm-group-end }
+SUPPLIER INVOKES
+{
+}
+::= id-ase-dtam-dm
+
+-- Remote operations
+        dm-document-open          DM-DOCUMENT-OPEN          ::= 13
+        dm-document-save          DM-DOCUMENT-SAVE           ::= 14
+        dm-document-discard       DM-DOCUMENT-DISCARD         ::= 15
+        dm-document-close         DM-DOCUMENT-CLOSE           ::= 16
+        dm-document-list          DM-DOCUMENT-LIST             ::= 17
+        dm-get                     DM-GET                      ::= 18
+        dm-search                  DM-SEARCH                   ::= 19
+        dm-create                  DM-CREATE                   ::= 20
+        dm-delete                  DM-DELETE                   ::= 21
+        dm-modify                  DM-MODIFY                    ::= 22
+        dm-copy                    DM-COPY                      ::= 23
+        dm-move                    DM-MOVE                      ::= 24
+        dm-replace                 DM-REPLACE                  ::= 25
+        dm-reserve                 DM-RESERVE                   ::= 26
+        dm-unreserve              DM-UNRESERVE                 ::= 27
+        dm-point                   DM-POINT                     ::= 28
+        dm-macro-call              DM-MACRO-CALL               ::= 29
+        dm-group-begin             DM-GROUP-BEGIN              ::= 30
+        dm-group-end               DM-GROUP-END                ::= 31
+
+-- Remote errors
+        dm-document-error          DM-DocumentError           ::= 14
+        dm-access-error           DM-AccessError              ::= 15
+        dm-reservation-error       DM-ReservationError         ::= 16
+        dm-fragment-error         DM-FragmentError            ::= 17
+        dm-save-error              DM-SaveError                ::= 18
+        dm-service-error           DM-ServiceError             ::= 19
+        dm-content-error           DM-ContentError              ::= 20
+        dm-attribute-error         DM-AttributeError            ::= 21
+        dm-list-error              DM-ListError                 ::= 22
+
+END -- of DTAM-DM-Protocol
+
+```
+
+## 7.2 Formal specification of the DTAM-TK protocol
+
+The abstract syntax specification of the DTAM-TK protocol is as follows:
+
+```
+
+DTAM-TK-Protocol { ccitt recommendation t 436 modules(0) tk-protocol(2) }
+DEFINITIONS ::= BEGIN
+EXPORTS
+
+-- DTAM-TK ASE
+        dTAM-TK-SE;
+
+IMPORTS
+
+```
+
+```
+
+-- Application service elements and application contexts
+    APPLICATION-SERVICE-ELEMENT, APPLICATION-CONTEXT,
+    rOSE
+    FROM Remote-Operation-Notation-extension
+    { joint-iso-ccitt remote-operation(4) notation-extension(2) }
+
+-- DTAM-TK abstract services
+    TK-TOKEN-GIVE, TK-TOKEN-PLEASE,
+
+-- DTAM-TK abstract errors
+    TK-ServiceError
+    FROM DTAM-TK-AbstractServices
+    { ccitt recommendation t 435 tk(2) modules(0) abstract-services(1) };
+
+-- DTAM-DM/DTAM-TK combined application context
+    dtam-dm-tk    APPLICATION-CONTEXT
+                  APPLICATION SERVICE ELEMENTS
+                  { aCSE }
+    BIND          DtamBind
+    UNBIND         DtamUnbind
+    REMOTE OPERATIONS { rOSE }
+    OPERATIONS OF { dTAM-DM-SE, dTAM-TK-SE }
+    ABSTRACT SYNTAXES
+    {
+        id-as-acse,          -- of ACSE
+        id-as-dtam-dm,       -- of DTAM-DM-SE
+        id-as-dtam-tk        -- of DTAM-TK-SE
+    }
+    ::= id-ac-dtam-dm-tk
+
+-- DTAM-TK service element
+    DTAM-TK-SE    APPLICATION-SERVICE-ELEMENT
+                  OPERATIONS { tk-token-give, tk-token-please }
+                  ::= id-ase-dtam-tk
+
+-- Remote operations
+    tk-token-give    TK-TOKEN-GIVE        ::= 32
+    tk-token-please  TK-TOKEN-PLEASE      ::= 33
+
+-- Remote errors
+    tk-service-error  TK-ServiceError      ::= 23
+
+END -- of DTAM-TK-Protocol
+
+```
+
+## 7.3 Definition of abstract syntax for DTAM-DM
+
+This Recommendation assigns the ASN.1 object identifier value:
+
+```
+
+id-as-dtam-dm OBJECT IDENTIFIER ::=
+{ ccitt recommendation t 436 abstract-syntax (2) dtam-dm (0) }
+
+```
+
+as an abstract syntax name for the set of presentation data values, each of which is either a value of the ASN.1 type:
+
+**ROSEapdus from Remote-Operations-APDUs**
+
+as defined in Recommendation X.229 with the argument, result or error component filled according to the definitions in the DTAM-DM protocol or a value of one of the ASN.1 type:
+
+**BIND from Remote-Operation-Notation.**  
+**UNBIND from Remote-Operation-Notation**
+
+as defined in Recommendation X.229 with the argument, result or error component filled according to the definitions of DTAM-DMBind and DTAM-DMUnBind in the DTAM-DM protocol.
+
+## 7.4 Definition of abstract syntax for DTAM-TK
+
+This Recommendation assigns the ASN.1 object identifier value:
+
+**id-as-dtam-tk OBJECT IDENTIFIER ::=**  
+**{ ccitt recommendation t 436 abstract-syntax (2) dtam-tk (1) }**
+
+as an abstract syntax name for the set of presentation data values, each of which is either a value of the ASN.1 type:
+
+**ROSEapdus from Remote-Operations-APDUs**
+
+as defined in Recommendation X.229 with the argument, result or error component filled according to the definitions in the DTAM-TK protocol.
+
+# 8 Conformance
+
+This clause provides conformance statements which have to be fulfilled by communication applications based on the DTAM-DM or DTAM-TK protocols.
+
+## 8.1 Conformance to the DTAM-DM protocol
+
+A DTAM-DM communication application claiming conformance to the DTAM-DM protocol specified in this Recommendation shall comply with the requirements noted below.
+
+### 8.1.1 Static requirements
+
+The system shall:
+
+- conform to the abstract-syntax definitions of subclause 7.1: “Formal specification of the DTAM-DM protocol”;
+- conform to one of the application-contexts of subclause 7.1: “Format specification of the DTAM-DM protocol”.
+
+### 8.1.2 Dynamic requirements
+
+The system shall:
+
+- supply operations conforming to subclause “Formal definition of DTAM-DM abstract services” of Annex B/T.435;
+- conform to the use of underlying services as defined in presentation service (Recommendation X.216), ACSE (Recommendation X.217) and ROSE (Recommendation X.219).
+
+## 8.2 Conformance to the DTAM-TK protocol
+
+A DTAM-TK communication application claiming conformance to the DTAM-TK protocol specified in this Recommendation shall comply with the requirements noted below.
+
+### 8.2.1 Static requirements
+
+The system shall:
+
+- conform to the abstract-syntax definitions of subclause 7.2 “Formal specification of the DTAM-TK protocol”;
+- conform to one of the application-contexts of subclause 7.2 “Formal specification of the DTAM-TK protocol” of this Recommendation.
+
+### 8.2.2 Dynamic requirements
+
+The system shall:
+
+- supply operations conforming to subclause “Formal definition of DTAM-TK abstract services” of Annex B/T.435;
+- conform to the use of underlying services as defined in presentation service (Recommendation X.216) and ROSE (Recommendation X. 219).
+
+# Annex A
+
+## Formal assignment of object identifiers
+
+(This annex forms an integral part of this Recommendation)
+
+All object identifiers which are used in this Recommendation are formally assigned in this annex using the ASN. 1 notation:
+
+**DTAM-DM-TK-Protocol { ccitt recommendation t 436 modules(0) object-identifiers(0) }**
+
+**DEFINITIONS ::=**
+
+**BEGIN**
+
+*-- EXPORTS everything*
+
+**ID ::= OBJECT IDENTIFIER**
+
+**id-dtam-tk-dm-protocol ID ::= { ccitt recommendation t 436 }**
+
+*-- Categories*
+
+**id-mod ID ::= { id-dtam-dm-tk-protocol 0 }** *-- modules*
+
+**id-ac ID ::= { id-dtam-dm-tk-protocol 1 }** *-- application context*
+
+**id-as ID ::= { id-dtam-dm-tk-protocol 2 }** *-- abstract syntax*
+
+**id-ase ID ::= { id-dtam-dm-tk-protocol 3 }** *-- application service element*
+
+*-- Modules*
+
+**id-mod-object-identifiers ID ::= { id-mod 0 }**
+
+**id-mod-dm-protocol ID ::= { id-mod 1 }**
+
+**id-mod-tk-protocol ID ::= { id-mod 2 }**
+
+*-- Application context*
+
+**id-ac-dtam-dm ID ::= { id-ac 0 }**
+
+**id-ac-dtam-dm-tk ID ::= { id-ac 1 }**
+
+**id-ac-dtam-dm-dfr ID ::= { id-ac 2 }**
+
+*-- Abstract syntax*
+
+**id-as-dtam-dm ID ::= { id-as 0 }**
+
+**id-as-dtam-tk ID ::= { id-as 1 }**
+
+*-- Application service element*
+
+**id-ase-dtam-dm ID ::= { id-ase 0 }**
+
+**id-ase-dtam-tk ID ::= { id-ase 1 }**
+
+**END -- of DTAM-DM-TK-ProtocolObjectIdentifiers**
\ No newline at end of file
diff --git a/marked/T/T-REC-T.44-200501-I_PDF-E/0f985b39edc1d52ba3600c438bc8f0a5_img.jpg b/marked/T/T-REC-T.44-200501-I_PDF-E/0f985b39edc1d52ba3600c438bc8f0a5_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..ac23cb8f6a8fba387803e22931ab7c0bf4255786
--- /dev/null
+++ b/marked/T/T-REC-T.44-200501-I_PDF-E/0f985b39edc1d52ba3600c438bc8f0a5_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:67a94a6ee521ba950ef52d7833477091e1ced946a75dd471c2bd12de36cbe7ab
+size 36056
diff --git a/marked/T/T-REC-T.44-200501-I_PDF-E/11edb7fcedf09ac6a817f8d7b8c61eec_img.jpg b/marked/T/T-REC-T.44-200501-I_PDF-E/11edb7fcedf09ac6a817f8d7b8c61eec_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..ad636b684547cb7f9c8aded44a3d101a4ce173b5
--- /dev/null
+++ b/marked/T/T-REC-T.44-200501-I_PDF-E/11edb7fcedf09ac6a817f8d7b8c61eec_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:5891dab87c2094f440e10cf5220d2d8ebf19f07e285fa4952ccbb87cee84433d
+size 34635
diff --git a/marked/T/T-REC-T.44-200501-I_PDF-E/2cde062fd82833415971a8bd1a2cafab_img.jpg b/marked/T/T-REC-T.44-200501-I_PDF-E/2cde062fd82833415971a8bd1a2cafab_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..221cdaf00bb2a623c2c4d3159da511df3b61517e
--- /dev/null
+++ b/marked/T/T-REC-T.44-200501-I_PDF-E/2cde062fd82833415971a8bd1a2cafab_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:7ac1301b946c1174331c39176523858683b271b0bbeda4fea8e294c6fdb2a156
+size 34192
diff --git a/marked/T/T-REC-T.44-200501-I_PDF-E/33ed1f9b27c7c21c797aa928b0f06851_img.jpg b/marked/T/T-REC-T.44-200501-I_PDF-E/33ed1f9b27c7c21c797aa928b0f06851_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..cb78c077f76a2a39706d308cb9b5c4ab0abb9cb3
--- /dev/null
+++ b/marked/T/T-REC-T.44-200501-I_PDF-E/33ed1f9b27c7c21c797aa928b0f06851_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:e1d52ecfff9dc031c42710349533f66b19cc26df084bcdc21d21e7f577170dc7
+size 56855
diff --git a/marked/T/T-REC-T.44-200501-I_PDF-E/4801720824e4b5e2361a5564f91cfb70_img.jpg b/marked/T/T-REC-T.44-200501-I_PDF-E/4801720824e4b5e2361a5564f91cfb70_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..a3a853a1a49ced65ce15c66d9a2db4daf6430979
--- /dev/null
+++ b/marked/T/T-REC-T.44-200501-I_PDF-E/4801720824e4b5e2361a5564f91cfb70_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:7d338587d078962c663a33ca782f1435de6f6fa13167f719404a8ddff2d881f0
+size 111695
diff --git a/marked/T/T-REC-T.44-200501-I_PDF-E/724c7777b608e53be38b12b6fb3c43bc_img.jpg b/marked/T/T-REC-T.44-200501-I_PDF-E/724c7777b608e53be38b12b6fb3c43bc_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..c29716ac1430f61018c6f2df2d1f2acf115463f3
--- /dev/null
+++ b/marked/T/T-REC-T.44-200501-I_PDF-E/724c7777b608e53be38b12b6fb3c43bc_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:ec02c1f34b01e0e2b9f83fc26c9456f1a19267198b4fd8ad899f084bdbc83149
+size 60022
diff --git a/marked/T/T-REC-T.44-200501-I_PDF-E/76b0cd79baaedd942af4dc42f2e764b8_img.jpg b/marked/T/T-REC-T.44-200501-I_PDF-E/76b0cd79baaedd942af4dc42f2e764b8_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..c48b99adaa44dc27a9c761322b8ea92b67be02e8
--- /dev/null
+++ b/marked/T/T-REC-T.44-200501-I_PDF-E/76b0cd79baaedd942af4dc42f2e764b8_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:577b1e3805e406684df5a7e6ddcbfde83deab8be65e3c8adb445714029be931a
+size 115991
diff --git a/marked/T/T-REC-T.44-200501-I_PDF-E/8fbdfc3d17fb1dae7b2d8f5a287fa9fc_img.jpg b/marked/T/T-REC-T.44-200501-I_PDF-E/8fbdfc3d17fb1dae7b2d8f5a287fa9fc_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..9c86f53b94393b9e2e524dd29f2a9a8fb2901423
--- /dev/null
+++ b/marked/T/T-REC-T.44-200501-I_PDF-E/8fbdfc3d17fb1dae7b2d8f5a287fa9fc_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:35ae5373fc5ce4d12001471e46d2aa51d42d62dd45aa14e86e1ea067a28c10cd
+size 47314
diff --git a/marked/T/T-REC-T.44-200501-I_PDF-E/a33da0f14e456f92539ce3e9b7d81f9a_img.jpg b/marked/T/T-REC-T.44-200501-I_PDF-E/a33da0f14e456f92539ce3e9b7d81f9a_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..af425af2de595931b1866d8f411563b11384ac6b
--- /dev/null
+++ b/marked/T/T-REC-T.44-200501-I_PDF-E/a33da0f14e456f92539ce3e9b7d81f9a_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:b1d5b2d53c36a9958270ebbbf48e17d853d057c28c76dd2bc76e9e256e0e4bc6
+size 107791
diff --git a/marked/T/T-REC-T.44-200501-I_PDF-E/af7916c89a458fdab6c3f443217388ae_img.jpg b/marked/T/T-REC-T.44-200501-I_PDF-E/af7916c89a458fdab6c3f443217388ae_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..6a8999125cf1d8468ea384e20322de474d03e1d4
--- /dev/null
+++ b/marked/T/T-REC-T.44-200501-I_PDF-E/af7916c89a458fdab6c3f443217388ae_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:158d21a9e102f8a2b33a52db3acc202708579ca09ed79d3cf82163885becc4b3
+size 74757
diff --git a/marked/T/T-REC-T.44-200501-I_PDF-E/e8ba5d4a3a22e24e44f7935ea26afcb0_img.jpg b/marked/T/T-REC-T.44-200501-I_PDF-E/e8ba5d4a3a22e24e44f7935ea26afcb0_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..36cf51f8ba07e44aa7a4b009f3ba08eb2b570b1c
--- /dev/null
+++ b/marked/T/T-REC-T.44-200501-I_PDF-E/e8ba5d4a3a22e24e44f7935ea26afcb0_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:11780faeee75ba39ab4ed9de67a9e67abec0d9ba3068ebec661dea70c16e29d3
+size 4338
diff --git a/marked/T/T-REC-T.44-200501-I_PDF-E/eefe19c5e14dc4d6c316b7f7fbb7d7d7_img.jpg b/marked/T/T-REC-T.44-200501-I_PDF-E/eefe19c5e14dc4d6c316b7f7fbb7d7d7_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..eed51d088feb44a8d8a64cfcd2998c967e44af2d
--- /dev/null
+++ b/marked/T/T-REC-T.44-200501-I_PDF-E/eefe19c5e14dc4d6c316b7f7fbb7d7d7_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:d1925d5d2335d2bbabf754c99a0418d902070aa18bececa3a0a1fa50eeabf3db
+size 84282
diff --git a/marked/T/T-REC-T.44-200501-I_PDF-E/fa859e4e468bfb2710a94527f2c504af_img.jpg b/marked/T/T-REC-T.44-200501-I_PDF-E/fa859e4e468bfb2710a94527f2c504af_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..4715519c01022cbc61b79cab6a91d58115821d18
--- /dev/null
+++ b/marked/T/T-REC-T.44-200501-I_PDF-E/fa859e4e468bfb2710a94527f2c504af_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:2f12402e61af098e5b8cf4601564836b29bf55cdd611d080b764ae95761e9992
+size 55758
diff --git a/marked/T/T-REC-T.44-200501-I_PDF-E/raw.md b/marked/T/T-REC-T.44-200501-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..e6109e9eff45566e7d9926a4f733c8f377716b10
--- /dev/null
+++ b/marked/T/T-REC-T.44-200501-I_PDF-E/raw.md
@@ -0,0 +1,2041 @@
+
+
+I n t e r n a t i o n a l   T e l e c o m m u n i c a t i o n   U n i o n
+
+# ITU-T
+
+TELECOMMUNICATION  
+STANDARDIZATION SECTOR  
+OF ITU
+
+# T.44
+
+(01/2005)
+
+SERIES T: TERMINALS FOR TELEMATIC SERVICES
+
+---
+
+**Mixed Raster Content (MRC)**
+
+ITU-T Recommendation T.44
+
+
+
+# ITU-T Recommendation T.44
+
+# Mixed Raster Content (MRC)
+
+## Summary
+
+This Recommendation specifies the technical features of Mixed Raster Content (MRC) imaging format that enables efficient processing, interchange and archiving of raster-oriented pages containing a mixture of multi-level and bi-level images. This efficiency is realized through segmentation of the image into multiple layers (planes), as determined by image type, and applying image specific encoding, spatial and colour resolution processing.
+
+A rasterized page may contain one or more image types, such as: multi-level continuous-tone or palletized colours (contone) usually associated with naturally occurring images; bi-level detail associated with text and line-art; multi-level colours associated with the text and line-art. This Recommendation makes provisions for processing, interchange, and archiving of these image types in multiple separate layers. Recombining the layers in a prescribed manner regenerates the original image.
+
+This edition of T.44 integrates Amendment 1 (which added a new Annex B which defines provisions for sharing resources across pages, stripes and layers and provisions for using colour tags as a means of representing text colour, that play an essential role in the application of JBIG2 of ITU-T Rec. T.88) with a number of additional modifications to the main body and its annexes that give the definition of the necessary technical specifications to support YCC colour space (as described in ITU-T Rec. T.42). This will allow the YCC colour space to be deployed using almost the same method as that of the LAB colour space.
+
+## Source
+
+ITU-T Recommendation T.44 was approved on 8 January 2005 by ITU-T Study Group 16 (2005-2008) under the ITU-T Recommendation A.8 procedure.
+
+This text includes the typo correction introduced by Erratum 1 (9 June 2005)
+
+## FOREWORD
+
+The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis.
+
+The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics.
+
+The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1.
+
+In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC.
+
+## NOTE
+
+In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure e.g. interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party.
+
+## INTELLECTUAL PROPERTY RIGHTS
+
+ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process.
+
+As of the date of approval of this Recommendation, ITU had received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementors are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database.
+
+© ITU 2005
+
+All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU.
+
+# CONTENTS
+
+###### Page
+
+|         |                                                     |    |
+|---------|-----------------------------------------------------|----|
+| 1       | Scope .....                                         | 1  |
+| 2       | References .....                                    | 1  |
+| 3       | Definitions .....                                   | 1  |
+| 4       | Conventions .....                                   | 3  |
+| 5       | Image representation .....                          | 3  |
+| 6       | Stripe structure .....                              | 3  |
+| 6.1     | Three-layer stripe (3LS) .....                      | 3  |
+| 6.2     | Two-layer stripe (2LS) .....                        | 4  |
+| 6.3     | One-layer stripe (1LS) .....                        | 4  |
+| 7       | Image coding .....                                  | 4  |
+| 7.1     | Spatial resolution .....                            | 4  |
+| 7.2     | Stripe width and layer width .....                  | 10 |
+| 7.3     | Stripe height and layer height .....                | 10 |
+| 7.4     | Layer combination .....                             | 11 |
+| 8       | Layer transmission order .....                      | 11 |
+| 9       | Data format .....                                   | 11 |
+| 9.1     | Overview .....                                      | 11 |
+| 9.2     | Page data structure .....                           | 11 |
+| 9.3     | Stripe data structure .....                         | 16 |
+| 9.4     | EOP (End of Page) .....                             | 17 |
+| 9.5     | Layer data structure .....                          | 17 |
+| 9.6     | Data format summary .....                           | 18 |
+| Annex A | Mixed Raster Content (MRC) Modes 2 and 3 .....      | 20 |
+| A.1     | Scope .....                                         | 20 |
+| A.2     | References .....                                    | 20 |
+| A.3     | Definitions .....                                   | 20 |
+| A.4     | Conventions .....                                   | 20 |
+| A.5     | Image representation .....                          | 20 |
+| A.6     | Stripe structure .....                              | 21 |
+| A.7     | Image coding .....                                  | 21 |
+| A.8     | Layer transmission order .....                      | 23 |
+| A.9     | Data format .....                                   | 23 |
+| Annex B | MRC Mode 4 – Shared resources and colour tags ..... | 31 |
+| B.1     | Scope .....                                         | 32 |
+| B.2     | References .....                                    | 32 |
+| B.3     | Definitions .....                                   | 33 |
+| B.4     | Shared data .....                                   | 33 |
+| B.5     | Colour tags .....                                   | 34 |
+| B.6     | Data format .....                                   | 35 |
+
+# Introduction and background
+
+The Mixed Raster Content (MRC) Recommendation is a way of describing raster-oriented (scanned and/or rasterized synthetic images) documents with both bi-level (text and/or line-art) and multi-level (colour/continuous-tone) data within a page. The goal of this MRC Recommendation is to make exchange of raster-oriented mixed content colour documents among users with varied communication systems possible with higher speed, higher image quality and modest computing resources (memory, storage and processing power).
+
+The dramatic increase in exchange of electronic documents has raised customer expectations and requirements for raster-oriented documents. Colour must be exchanged just as gracefully and efficiently as black & white (bi-level) and quickly reproduce a copy of the original at the best possible image quality for that output device. The following technical relations can be associated with the customer requirements:
+
+- efficient exchange of the raster data is directly related to the file size and compression ratios;
+- image quality in a scan-anywhere, print-anywhere environment is directly related to the exchange of device-independent data forms and the rendering compromises made by the output engine;
+- fast printing with modest resources is related to low complexity of the format.
+
+The best approach to achieve high compression ratios and retain quality is to compress the different segments of the raster data according to their individual attributes. Text and line-art data (bi-level data) would be compressed with an approach that puts high emphasis on maintaining the detail and structure of the input. Pictures and colour gradients (multi-level data) would be compressed using an approach that puts a high emphasis on maintaining the smoothness and accuracy of the colours. These different data types (bi-level and multi-level) are often conceptualized as being on separate layers/planes within the page.
+
+This separation of the data by importance of content (spatial detail vs colour) also directly implies that it is advantageous to use different resolutions for the different data, with a high spatial resolution used for text/line-art and high colour resolution for images/gradients.
+
+This concept of data separation by importance of content has led to development of the base mode 3-layer model on which the MRC Recommendation is built. Provisions to extend the model beyond the base mode are defined in Annex A. The base mode 3-layer model identifies three basic data types that may be contained within a page. These are multi-level data associated with contone colour (continuous-tone and/or palletized colour) image for which mid-to-low spatial and high colour resolution is typically appropriate for good reproduction; bi-level data associated with high detail of text/line-art for which high spatial and low colour resolution is typically appropriate for good reproduction; multi-level data associated with multi-level colours of the text/line-art data for which mid-to-high spatial and mid-colour resolution is typically appropriate for good reproduction. Each page within the MRC model is processed independently. The data types within each page are represented in distinct layers (also referred to as planes) to be image processed, compressed and transmitted independently. Multi-level contone data may be represented in the lower layer, bi-level in the middle layer and multi-level data of text/line-art colours in the upper layer. The lower and upper layers will from here on be referenced as the background and foreground layers respectively, see Figure 1. The process of image regeneration is controlled by the middle bi-level layer that acts as a mask or selector to select whether pixels from the background contone layer or foreground text/line-art colour layer will be reproduced. Due to its selection function, this layer is referenced as the mask or selector layer; throughout this Recommendation the middle layer will be referenced as the mask layer. When the value of a mask layer pixel is one (1), the corresponding pixel from the foreground is selected and reproduced. When the value of the mask layer pixel is zero (0), the corresponding pixel from the background is selected and reproduced, see Figure 2.
+
+Given limited device memory in many facsimile implementations and that mixed content pages often have a mixture of: text/line-art (monochrome or coloured) regions; contone image regions; text/line-art (monochrome or coloured) and contone image regions, there are provisions to subdivide the page into horizontal stripes that span the entire width of the page and isolate individual regions, see Figure 3. Stripes are composed of one or more layers as determined by the image type within the stripe. The mask layer must span the entire width and height of the stripe. The background and foreground layers need not span the width and height of the stripe. Reduction in the amount of white space coded in the background or foreground layers can be realized by taking advantage of the image width and height data included in the layer data stream and a horizontal and vertical offset provision. The default of the foreground base colour is black (layer base colour can be changed to any colour). The base colour is defined such that at mask pixel locations (value = 1) where
+
+a corresponding foreground pixel is not present, the foreground layer base colour is applied. The default of the background base colour is white (layer base colour can be changed to any colour). The base colour is defined such that at mask pixel locations (value = 0) where a corresponding contone image is not present, the background layer base colour is applied, see Figure 4.
+
+The 3-layer model has 3 types of horizontal stripes that are implemented according to the type of data being addressed:
+
+- 3-layer stripe (3LS), so referenced since it contains all three of the foreground, mask and background layers as in Figure 1. The 3LS is appropriate when addressing an image that contains both multi-coloured text/line-art and contone image or monochrome text/line-art on coloured background and contone image, as in stripes 3 and 5 of Figures 3 and 8;
+- 2-layer stripe (2LS), so referenced since it contains coded data for two of the three layers (the third is set to a fixed value). The two layers may be mask and background, as in Figure 6a, or mask and foreground layers, as in Figure 6b. All combination of multiple layers shall include the mask layer. The 2LS is appropriate when addressing an image that contains monochrome text/line-art and contone image or coloured text/line-art and no contone image, as in stripes 2 and 7 of Figures 3 and 8;
+- 1-layer stripe (1LS), so referenced since it contains coded data for only one of the three layers (the other two are set to fixed values). The one layer may be mask, as in Figure 7a, background, as in Figure 7b, or foreground, as in Figure 7c. The 1LS is appropriate when addressing an image that contains one of monochrome text/line-art, contone image or possibly richly coloured graphics, as in stripes 1, 4 and 6 of Figures 3 and 8.
+
+Figure 8 provides an illustration of the various stripe types that may apply to the various image regions within a page.
+
+The 3-layer model requires application of a multi-level coding scheme to the background and foreground layers. Any ITU-T multi-level coding (such as JPEG or JBIG, as defined in ITU-T Recs T.81 and T.43, respectively) may be used for the background or foreground. A bi-level coding scheme is required for the mask layer, any ITU-T bi-level coding (such as JBIG or MMR, as defined in ITU-T Recs T.85 and T.6, respectively) may be used, see Figure 5. The specific coders used throughout the page and over the various layers are identified at the start of each page. This information is provided by parameters in a Start of Page (SOP) Marker Segment. The spatial resolution of the mask layer, to be used throughout the page, is also identified by a SOP parameter. Layers with varied spatial resolutions may be combined within a stripe, the resolution of the foreground and background layers must be integral factors of the mask resolution layer, see Figure 5. The specific resolutions being used in the foreground and background layers are identified within a marker segment at the start of each layer within a stripe. A Start of Stripe marker segment contains parameters indicating type of stripe (1LS, 2LS or 3LS), the foreground and background layer base colour, offset of the foreground and/or background, the stripe height (number of lines) and the mask layer coded data length (number of octets).
+
+An SOP marker segment denotes the beginning of an MRC page. This is followed by page data and terminated with a EOP (End of Page). The page data consists of stripes. During transmission, stripes are sent sequentially from the top of the page, stripe 1 through N, where N is an integer. Within a stripe, the mask layer is transmitted first, followed by the background and then the foreground as appropriate.
+
+
+
+## Recommendation T.44
+
+## Mixed Raster Content (MRC)
+
+# 1 Scope
+
+This Recommendation defines a means to efficiently represent raster-oriented pages that contain a mixture of multi-level and bi-level images. Any of the many ITU-T recommended encoding schemes, such as T.81 (JPEG) for the encoding of multi-level images and T.6 (MMR) for the encoding of bi-level images, may be combined within the context of this Recommendation. Similarly, ITU-T spatial and colour resolutions may be combined within a page. This Recommendation does not define new encodings or resolutions. The method of image segmentation is beyond the scope of this Recommendation; segmentation is left to manufacturers' implementation.
+
+# 2 References
+
+The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation.
+
+- ITU-T Recommendation T.4 (2003), *Standardization of Group 3 facsimile terminals for document transmission*.
+- ITU-T Recommendation T.6 (1988), *Facsimile coding schemes and coding control functions for Group 4 facsimile apparatus*. (Commonly referred to as MMR standard.)
+- ITU-T Recommendation T.42 (2003), *Continuous-tone colour representation method for facsimile*.
+- ITU-T Recommendation T.43 (1997), *Colour and gray-scale image representations using lossless coding scheme for facsimile*.
+- ITU-T Recommendation T.81 (1992) | ISO/IEC 10918-1:1994, *Information technology – Digital compression and coding of continuous-tone still images – Requirements and guidelines*. (Commonly referred to as JPEG standard.)
+- ITU-T Recommendation T.82 (1993) | ISO/IEC 11544:1993, *Information technology – Coded representation of picture and audio information – Progressive bi-level image compression*. (Commonly referred to as JBIG standard.)
+- ITU-T Recommendation T.85 (1995), *Application profile for Recommendation T.82 – Progressive bi-level image compression (JBIG coding scheme) for facsimile apparatus*.
+- ITU-T Recommendation T.86 (1998) | ISO/IEC 10918-4:1999, *Information technology – Digital compression and coding of continuous-tone still images: Registration of JPEG profiles, SPIFF profiles, SPIFF tags, SPIFF colour spaces, APPn markers, SPIFF Compression types and Registration Authorities (REGAUT)*.
+
+# 3 Definitions
+
+The definitions contained in ITU-T Recs T.4, T.6, T.42, T.43, T.81, T.82 and T.85 apply, unless explicitly amended.
+
+**3.1 APP13 marker:** Encoded as X'FFED', is the application marker, registered per ITU-T Rec. T.86, that uniquely identifies MRC.
+
+**3.2 end of page (EOP):** Encoded as two consecutive JPEG EOI (X'FFD9FFD9').
+
+**3.3 JBIG:** Joint Bi-level Image Experts Group, and also shorthand for the encoding method, described in ITU-T Rec. T.82, which was defined by this group.
+
+NOTE – It is expected that JBIG will be changed to JBIG1 when referencing ITU-T Rec. T.82. This nomenclature change is the result of a new standard that is being developed by the JBIG committee. This new standard will be referenced as JBIG2.
+
+**3.4 JPEG:** Joint Photographic Experts Group, and also shorthand for the encoding method, described in ITU-T Rec. T.81, which was defined by this group.
+
+**3.5 layer:** An image, either multi-level or bi-level, that is to be combined with other images using the method described here. Layers are encoded using ITU-T coding methods. One or more layers may be used.
+
+**3.6 background layer:** The "bottom" layer (layer 1), multi-level data associated with a contone image segment, in a 3-layer segmentation of a page containing a combination of bi-level and multi-level images.
+
+At background pixel locations where the contone background image is not present, a background layer base colour (default of white) is applied. A means to define other values of background layer base colour is provided within the syntax described in clause 9.
+
+**3.7 contone layer:** Continuous-tone and/or palletized colour. This definition is intended to account for both scanner and synthetic source image data. When a scanner is the source of an image, both continuous-tone and solid coloured images would be available as continuous-tone data. When the source of an image is synthetic, continuous-tone and solid coloured images may be available as continuous-tone or palletized colour data.
+
+**3.8 foreground layer:** The "top" layer (layer 3), multi-level data associated with colours of text, graphics or line-art, in a 3-layer segmentation of a page containing a combination of bi-level and multi-level images.
+
+At foreground pixel locations where the multi-level data associated with colours of text, graphics or line-art is not present, a foreground layer base colour (default of black) is applied. A means to define other values of foreground layer base colour is provided within the syntax described in clause 9.
+
+**3.9 image layer:** Odd-numbered layer (e.g., layers 1, 3, 5, ...), multi-level data associated with contone images, colours of texts, graphics or line-art, in a multi-layer segmentation of a page containing a combination of bi-level and multi-level images.
+
+At image layer pixel locations, above layer 1, where the image is not present, a layer base colour, default of black, is applied. At layer 1 pixel locations where the image is not present, a layer base colour, default of white, is applied. A means to define other layer base colour values is provided within the syntax described in clause 9.
+
+**3.10 mask layer:** Even-numbered layers (i.e., layers 2, 4, 6, ...), bi-level data, in a multi-layer segmentation of a page containing a combination of bi-level and multi-level images. The bi-level mask layer selects the image layer directly above it or the image(s) below it to be visible. A corresponding image layer pixel above the mask layer is selected for reproduction when a mask layer pixel value is "1". A corresponding pixel from the image or collection of images below the mask is selected when a mask pixel value is "0".
+
+The first mask layer (layer 2) may be distinguished as the main mask. The main mask selects the foreground or background to be visible. In a 3-layer segmentation it is simply referenced as the mask layer. When there is more than one mask layer, the other mask layers (layers 4, 6, 8, ...) may be referenced as the overlay masks.
+
+**3.11 virtual mask layer:** Even-numbered layer (i.e., layers 2, 4, 6, ...) that contains no coded data. A virtual mask layer is used to establish dimensions of a page or stripe when there is no coded mask layer that spans the full dimensions of the page or stripe.
+
+**3.12 Modified Huffman (MH)** is shorthand for the lossless bi-level one-dimensional encoding method described in ITU-T Rec. T.4.
+
+**3.13 modified modified READ (MMR)** (READ is an acronym for Relative Element Address Designate) is shorthand for the lossless bi-level encoding method described in ITU-T Rec. T.6.
+
+**3.14 modified READ (MR)** (READ is an acronym for Relative Element Address Designate) is shorthand for the lossless bi-level two-dimensional encoding method described in ITU-T Rec. T.4.
+
+**3.15 MRC magic number:** MRC Magic number, encoded as the JPEG SOI (Start of Image – X'FFD8') to alert decoders that JPEG application markers registered per ITU-T Rec. T.86 follow.
+
+**3.16 start of page marker segment (SOP):** Encoded as APP13 (X'FFED'), length of segment, SOP ident (MRC0), parameters.
+
+**3.17 start of stripe marker segment (SOST):** Encoded as APP13 (X'FFED'), length of segment, SOST ident (MRC1), parameters.
+
+**3.18 stripe:** An image swath, spanning the width of the page, that may consist of one or more layers.
+
+**3.19 termination number (TN):** Encoded as the JPEG EOI (End of Image – X'FFD9') to alert decoders to the end of the initial JPEG application marker registered per ITU-T Rec. T.86. The TN is located directly after the SOP parameters.
+
+# 4 Conventions
+
+The conventions in ITU-T Rec. T.81 apply to this Recommendation.
+
+# 5 Image representation
+
+This Recommendation includes description of syntax for encapsulating one or more ITU-T encodings on a single page.
+
+A page is composed from a set of page-wide stripes of image data, which are coded independently. The stripes are transmitted sequentially from the top to the bottom of the page.
+
+In the base mode, stripes are composed of one to three (3) layers. Each layer is coded using a recommended ITU-T coding method. The base mode is mandatory and must be supported by all future modes. All future modes should support all previously defined modes unless specified otherwise.
+
+Information required to decode the page, such as coding types used within the layers, is specified within the page header (start of page marker segment). Stripe height is specified within the stripe header (start of stripe marker segment).
+
+Information required to decode a layer is included in the stripe header and the layer data.
+
+In the base mode, the mask layer is transmitted first, followed by the background layer and then the foreground layer.
+
+Details of the syntax are described below.
+
+# 6 Stripe structure
+
+In the base mode, stripes are composed of one to three layers; background layer, mask layer and foreground layer. Annex A makes provision for stripes to be composed of more than three layers. One or more layers may be assigned a fixed value (e.g., fixed colour value). Virtual mask layers and fixed value layers are not counted in classifying the stripe types as follows:
+
+- Three-layer stripe: (3LS)
+- Two-layer stripe: (2LS)
+- One-layer stripe: (1LS)
+
+## 6.1 Three-layer stripe (3LS)
+
+3LS is the basic structure of this Recommendation. The 3LS contains foreground, mask and background layers, see Figure 1 and stripes 3 and 5 of Figure 8. It provides a means to transfer two images and a bi-level mask layer describing their recombination on the same page. This capability enables representation of richly coloured text, graphics, and line-art together with contone imagery in the same region using only multi-level and bi-level coding methods. It also enables representation of monochrome or coloured text, graphics, and line-art that resides on a coloured background together with contone image in the same region. The
+
+text/line-art colour is placed in the foreground layer and the contone image in the background layer. The bi-level mask plane is used to select which of the images is expressed at every pixel location within the stripe. It may contain the high detail text shape or rectangular outlines of text and contone image areas.
+
+## **6.2 Two-layer stripe (2LS)**
+
+2LS is one of the special cases of the 3LS, in which one of the foreground or background layers is assigned a fixed colour value. The mask layer is mandatory in the 2LS stripe. The 2LS contains mask and background or mask and foreground layers. For the case of mask and background, the foreground is set to a layer base colour value (e.g., black), see Figure 6a and stripe 2 of Figure 8. It provides a means to transfer a continuous-tone image, a layer base colour value and a bi-level mask layer describing their recombination on the same page. This capability enables representation of monochrome text, graphics, and line-art together with contone imagery in the same region using only multi-level and bi-level coding methods. The monochrome text/line-art may overlay the coloured image. The text/line-art colour is represented by the fixed foreground value while the contone image is in the background layer. The bi-level mask plane is used to select which of the foreground layer base colour or the background images is expressed at every pixel location within the stripe. The mask contains the high detail shape of text, graphics or line-art. For the case of mask and foreground, the background is set to a layer base colour value (e.g., white), see Figure 6b and stripe 7 of Figure 8. It provides a means to transfer a colour foreground image, a background layer base colour value and a bi-level mask layer describing their recombination on the same page. This capability enables representation of coloured text, graphics, and line-art without contone imagery in the same region using multi-level and bi-level coding methods. The bi-level mask plane is used to select which of the foreground or the background images is expressed at every pixel location within the stripe.
+
+## **6.3 One-layer stripe (1LS)**
+
+1LS is one of the special cases of the 3LS, in which two of the three layers are assigned a fixed value (e.g., fixed colour value in the case of fixed foreground or background layer). The 1LS contains a single coded layer. If the layer is coded using a bi-level coding method, the fixed foreground and background base layer colour values, defined within the stripe, are applied; a bi-level image is treated as a mask layer, see Figure 7a and stripe 1 of Figure 8. A page containing a single bi-level 1LS, where the foreground and background colours are the values of black and white respectively, is similar to a conventional bi-level facsimile page, see Figure 7a. There are two cases if the coding method is multi-level. Case 1: the mask is fixed to "0" (foreground colour is not applied) and the background layer base colour (e.g., white) is applied outside the area coded, see Figure 7b and stripes 4 and 6 of Figure 8. Case 2: the mask is fixed to "1" (background colour is not applied) and the foreground layer base colour (e.g., white in this case) is applied outside the area coded, see Figure 7c. To represent dimensions of pages that contain only case 1 or 2 stripe(s), where there is no coded mask data, a virtual mask layer should be assumed. The resolution of the virtual mask is fixed to that of the foreground or background layer while the dimensions of the virtual mask are fixed to the page dimensions, such as page width and height (number of scan lines). The width of the stripe is fixed to the page width. It is possible in cases 1 and 2 that the foreground or background layers may contain a fixed colour value (e.g., a layer base colour value); in effect there is no encoded colour data.
+
+The 1LS is applied to areas containing only monochrome text, graphics (e.g., business graphics)/line-art, or continuous-tone image data.
+
+# **7 Image coding**
+
+## **7.1 Spatial resolution**
+
+The resolution of the main mask layer is fixed for the entire page and defines the maximum resolution for the page. In general it is possible to define foreground and background layers of lower spatial resolution. Spatial resolution of all layers must be integral factors of the main mask layer resolution. All resolutions used must be square (i.e., same horizontal and vertical values) and conform to ITU-T recommended values. The main mask resolution is specified in the page header. The foreground and background resolutions are indicated in the layer data.
+
+![Diagram showing the decomposition of a text and image into foreground, mask, and background layers.](af7916c89a458fdab6c3f443217388ae_img.jpg)
+
+The diagram illustrates the decomposition of a source image into three distinct layers:
+
+- Foreground (Multi-level, text colour):** This layer contains the text "Did you ever get a sinking feeling?" where the words "ever get a" are red and "sinking feeling?" are green. It is represented as a 3D block with red and green faces.
+- Mask (Bi-level, text shape or rectangular text/contone outline):** This layer defines the shape of the text and the image. It is shown as a 3D block with a white face containing the text outline and a black face containing the image outline.
+- Background (Multi-level contone images):** This layer contains the cartoon image of three people. It is represented as a 3D block with a white face containing the image and a black face.
+
+Arrows indicate the mapping from the source image to these three layers. The source image has "red" and "green" labels pointing to the text colors. The 3D blocks are labeled with "red" and "green" pointing to their respective colored faces. The identifier "T0828670-99/d01" is located at the bottom right of the diagram.
+
+Diagram showing the decomposition of a text and image into foreground, mask, and background layers.
+
+Figure 1/T.44
+
+![Diagram showing the process of generating foreground and background colors based on mask pixel values.](eefe19c5e14dc4d6c316b7f7fbb7d7d7_img.jpg)
+
+The diagram illustrates the process of generating foreground and background colors based on mask pixel values:
+
+- Foreground Generation:**
+  - 1. mask pixel = 1:** When a mask pixel is 1, the foreground color is selected.
+  - 2. foreground pixel selected:** The selected foreground pixel is used to generate the text color.
+  - 3. text colour generated:** The final text color is generated.
+- Background Generation:**
+  - 1. mask pixel = 0:** When a mask pixel is 0, the background color is selected.
+  - 2. background pixel selected:** The selected background pixel is used to generate the contone color.
+  - 3. contone colour generated:** The final contone color is generated.
+
+The diagram shows the flow of data between these steps and the resulting foreground and background layers. The foreground layer has "red" and "green" labels pointing to its colored faces. The background layer has "red" and "green" labels pointing to its colored faces. The identifier "T0828560-99/d02" is located at the bottom right of the diagram.
+
+Diagram showing the process of generating foreground and background colors based on mask pixel values.
+
+Figure 2/T.44
+
+![Cartoon of people on a sinking island Cartoon of people in the water](4801720824e4b5e2361a5564f91cfb70_img.jpg)
+
+|                                                                                                                                                                                  |                                              |
+|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------|
+| <p>If we do not make Recommendations together, we will surely not make them at all.</p>                                                                                          | <p>Stripe 1: monochrome text</p>             |
+| <p>Did you ever get a sinking feeling?</p>                                                                                                                                       | <p>Stripe 2: monochrome text and contone</p> |
+| <p>Time to pull green and red together?</p>                                                                                                                                      | <p>Stripe 3: coloured text and contone</p>   |
+| <p></p>                                                                                                                                                                          | <p>Stripe 4: contone</p>                     |
+| <p>Too yellow late! Too red late!</p>                                                                                                                                            | <p>Stripe 5: coloured text on contone</p>    |
+|                                                                                                                                                                                  | <p>Stripe 6: contone</p>                     |
+| <p>But it is better to have proposed yellow and failed, than to never have proposed blue. But better still to propose and see success in red document and green marketplace.</p> | <p>Stripe 7: coloured text</p>               |
+
+Cartoon of people on a sinking island Cartoon of people in the water
+
+T0828570-99/d03
+
+Figure 3/T.44
+
+![Diagram illustrating the color selection process for text and background in a video frame. It shows a sequence of steps: 1. mask pixel selection, 2. foreground/background pixel selection, and 3. color generation (text or contone). The process is applied to a frame containing text and a cartoon image. A legend shows color selection for red and green channels.](a33da0f14e456f92539ce3e9b7d81f9a_img.jpg)
+
+The diagram illustrates the color selection process for text and background in a video frame. It shows a sequence of steps:
+
+- 1. mask pixel = 1**: Selects foreground pixels (text).
+- 2. foreground pixel selected**: Selects the foreground pixel color (e.g., red for 'Did', green for 'you').
+- 3. text colour generated**: Generates the final text color.
+- 1. mask pixel = 0**: Selects background pixels (cartoon).
+- 2. background pixel selected**: Selects the background pixel color (e.g., white for the cartoon).
+- 3. default background colour (white) generated**: Generates the final background color.
+- 3. contone colour generated**: Generates the final contone color.
+
+The process is applied to a frame containing text and a cartoon image. A legend shows color selection for red and green channels:
+
+- red**: Red color selected.
+- green**: Green color selected.
+- dotted area not coded or sent**: Areas where color information is not present.
+
+Diagram illustrating the color selection process for text and background in a video frame. It shows a sequence of steps: 1. mask pixel selection, 2. foreground/background pixel selection, and 3. color generation (text or contone). The process is applied to a frame containing text and a cartoon image. A legend shows color selection for red and green channels.
+
+T0828580-99/d04
+
+Figure 4/T.44
+
+![Diagram illustrating the structure of a video frame with foreground and mask planes.](33ed1f9b27c7c21c797aa928b0f06851_img.jpg)
+
+The diagram shows a 3D representation of a video frame structure. It consists of three main planes:
+
+- Foreground (e.g., JBIG @ 12 bpp, 100 dpi):** The top plane, which is divided into a red rectangular area and a green rectangular area. Arrows labeled "red" and "green" point to these areas respectively.
+- Mask (e.g., MMR @ 1 bpp, 400 dpi):** The middle plane, which contains the text "Did you ever get a sinking feeling?". A dashed line indicates a "dotted area not coded or sent" above the text.
+- Foreground (e.g., JPEG @ 24 bpp, 200 dpi):** The bottom plane, which contains a cartoon illustration of three people. A dashed line indicates a "dotted area not coded or sent" to the left of the illustration.
+
+The reference ID "T0828590-99/d05" is located at the bottom right of the diagram.
+
+Diagram illustrating the structure of a video frame with foreground and mask planes.
+
+**Figure 5/T.44**
+
+![Diagram illustrating the relationship between foreground, mask, and background planes.](724c7777b608e53be38b12b6fb3c43bc_img.jpg)
+
+The diagram shows a 3D representation of the relationship between three planes:
+
+- Foreground (constant – black):** A plane indicated by a straight arrow from the source image to the top of the 3D block.
+- Mask (Bi-level, text shape or rectangular text/contone outline):** The top face of the 3D block, containing the text "Did you ever get a sinking feeling?". A curved arrow points from the text in the source image to this plane.
+- Background (Multi-level contone images):** The bottom face of the 3D block, containing the cartoon illustration of three people. A curved arrow points from the illustration in the source image to this plane.
+
+The reference ID "T0828600-99/d06" is located at the bottom right of the diagram.
+
+Diagram illustrating the relationship between foreground, mask, and background planes.
+
+**Figure 6a/T.44 – Mask and background**
+
+![Diagram illustrating the relationship between text, foreground, mask, and background for a 3D effect.](fa859e4e468bfb2710a94527f2c504af_img.jpg)
+
+The diagram shows a 2D rectangular box on the left containing the text "Did you ever get a sinking feeling?". The text is color-coded: "Did you" and "ever get a" are red, and "sinking feeling?" is green. Arrows labeled "red" and "green" point to these respective parts of the text. Three arrows originate from the right side of the 2D box and point to a 3D box on the right. The 3D box is labeled "Foreground (Multi-level, text colour)" and contains two colored rectangles (red and green) and the text "Did you ever get a sinking feeling?". Arrows labeled "red" and "green" point to these colored rectangles. The 3D box is also labeled "Mask (Bi-level, text shape or rectangular text/contone outline)". A label "T0828610-99/d07" is located near the bottom right of the 3D box. A label "Background (constant – white)" is located below the 3D box.
+
+Diagram illustrating the relationship between text, foreground, mask, and background for a 3D effect.
+
+**Figure 6b/T.44 – Mask and foreground**
+
+![Diagram illustrating the relationship between text, foreground, mask, and background for a 2D effect.](0f985b39edc1d52ba3600c438bc8f0a5_img.jpg)
+
+The diagram shows a 2D rectangular box on the left containing the text "Did you ever get a sinking feeling?". Three arrows originate from the right side of the 2D box and point to three labels: "Foreground (constant – black)", "Mask (Bi-level, text shape)", and "Background (constant – white)". The "Mask" label points to a 3D box on the right that contains the text "Did you ever get a sinking feeling?". The 3D box is labeled "Mask (Bi-level, text shape)" and "T0828620-99/d08".
+
+Diagram illustrating the relationship between text, foreground, mask, and background for a 2D effect.
+
+**Figure 7a/T.44 – Mask**
+
+![Diagram showing the decomposition of a cartoon image into foreground, mask, and background components.](8fbdfc3d17fb1dae7b2d8f5a287fa9fc_img.jpg)
+
+The diagram illustrates the decomposition of a source image (a cartoon of three people) into three components:
+
+- Foreground (constant – black)**: A black rectangular area representing the foreground mask.
+- Mask (constant – 0)**: A white rectangular area representing the background mask.
+- Background (Multi-level contone images)**: A tilted rectangular area containing the original cartoon image, representing the background.
+
+T0828630-99/d09
+
+Diagram showing the decomposition of a cartoon image into foreground, mask, and background components.
+
+**Figure 7b/T.44 – Background**
+
+![Diagram showing the decomposition of a color graphic image into foreground, mask, and background components.](2cde062fd82833415971a8bd1a2cafab_img.jpg)
+
+The diagram illustrates the decomposition of a source image (a color graphic of a sphere) into three components:
+
+- Foreground (Multi-level, colour graphics images)**: A rectangular area containing the original color graphic, representing the foreground.
+- Mask (constant – 1)**: A white rectangular area representing the foreground mask.
+- Background (constant – white)**: A white rectangular area representing the background.
+
+T0828640-99/d10
+
+Diagram showing the decomposition of a color graphic image into foreground, mask, and background components.
+
+**Figure 7c/T.44 – Foreground**
+
+![Cartoon of five people on a sinking island Cartoon of a sinking island with sharks](76b0cd79baaedd942af4dc42f2e764b8_img.jpg)
+
+|                                                                                                                                                                                  |                                                  |
+|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------|
+| <p>If we do not make recommendations together, we will surely not make them at all.</p>                                                                                          | <p>Stripe 1: 1LS, mask</p>                       |
+| <p>Did you ever get a sinking feeling?</p>                                                                                                                                       | <p>Stripe 2: 2LS, mask/background</p>            |
+| <p>Time to pull green and red together?</p>                                                                                                                                      | <p>Stripe 3: 3LS, mask/background/foreground</p> |
+| <p></p>                                                                                                                                                                          | <p>Stripe 4: 1LS, background</p>                 |
+| <p>Too yellow late! Too red late!</p>                                                                                                                                            | <p>Stripe 5: 3LS, mask/background/foreground</p> |
+|                                                                                                                                                                                  | <p>Stripe 6: 1LS, background</p>                 |
+| <p>But it is better to have proposed yellow and failed, than to never have proposed blue. But better still to propose and see success in red document and green marketplace.</p> | <p>Stripe 7: 2LS, mask/foreground</p>            |
+
+Cartoon of five people on a sinking island Cartoon of a sinking island with sharks
+
+T0828650-99/d11
+
+Figure 8/T.44
+
+## 7.2 Stripe width and layer width
+
+Stripes always span the entire width of a page. The main mask layer must always span the entire width.
+
+This method takes advantage of the image width and height data included in the layer data stream, such as JPEG. A foreground and/or background layer (e.g., JPEG data) is not required to span the entire width. All layers must be fully contained within the boundaries of the stripe. In addition, a horizontal offset may be used to select a starting point to the right of the left stripe boundary. This offset is expressed in the main mask layer pixel units. A simple stripe containing only background (e.g., JPEG data) or foreground (e.g., T.43 JBIG data) image data may use this feature also.
+
+## 7.3 Stripe height and layer height
+
+To limit the data that must be buffered by an application, some applications may choose to limit the maximum height of two or more layer stripes (2LS & 3LS) to a specified number of lines (in mask layer resolution).
+
+One-layer stripes (1LS) are not required to conform to a maximum stripe height, and are only limited by page size. Layers without coded data (i.e., virtual mask layers and image layers with only base layer colour) are not to be counted when considering whether a stripe is a 1LS, 2LS or 3LS stripe.
+
+Stripe and main mask layer heights are always equal. Foreground and background layer heights are less than or equal to stripe heights. All layers must be fully contained within the boundaries of the stripe. In addition, a vertical offset may be used to select a starting point below the first scan line of the stripe. This offset is expressed relative to the first scan line at the top of the stripe and in the main mask pixel units. A simple stripe containing only background (e.g., JPEG) or foreground (e.g., JBIG) data may use this feature also.
+
+## 7.4 Layer combination
+
+Image layers are rendered sequentially in ascending order of layer number (i.e., layer 1 then 3). The background layer (i.e., layer 1), if present, shall be rendered first. Bi-level mask layers (even-numbered layers, such as layer 2) select pixels from their corresponding image layer (odd-numbered layer directly above the mask layer, such as layer 3) for rendering. A corresponding image layer pixel (directly above the mask layer pixel), or its layer base colour value, is selected when a mask pixel value is "1". The selected image layer pixel is rendered on top of any layer that may have been previously rendered. A corresponding image layer pixel shall not be rendered when the mask pixel value is "0". The pixel from the layer below the mask, or its layer base colour value, shall remain visible when the mask pixel value is "0". In the event of an image layer (i.e., layer 3), or portion thereof, without a corresponding mask layer, the image layer shall be rendered on top of any previously rendered layer.
+
+# 8 Layer transmission order
+
+In 3LS, the bi-level mask data is transmitted first, followed by the background layer and then the foreground layer. In 2LS, the bi-level mask image data is transmitted first, followed by the background or foreground layer.
+
+# 9 Data format
+
+## 9.1 Overview
+
+The MRC image data consist of a series of: markers; parameter data that specify the image coder, image size, bit-resolution and spatial resolution; image data. The conventions of Annex B/T.81 are used broadly here. The JPEG registration body, per ITU-T Rec. T.86, has been used to register the marker code, APP13, classified as an application marker.
+
+The MRC page structure for this application has the following elements: parameters, markers, and entropy-coded data segments. Parameters and markers are often organized into marker segments. Parameters are integers of length  $\frac{1}{2}$ , 1, 2 or more octets. Markers are assigned two or more octet codes, an X'FF' octet followed by an octet not equal to X'00' or X'FF' and optionally preceded by extra X'FF' octet codes. This base mode application defines marker segments to denote the Start of Page (SOP), optional marker segments and the Start of Stripe (SOS). The MRC Magic Number (JPEG SOI) is used immediately preceding the application marker as part of the SOP marker segment. The JPEG EOI is used as a termination number located directly after the last SOP parameter. The end of a page (EOP) is defined as X'FFD9FFD9'. These markers are inserted by the encoder, and understood by the decoder in addition to all markers used for the coding methods, such as SOS (start of scan) of ITU-T Rec. T.81.
+
+A distillation of the bit and byte ordering conventions of Annex B/T.81 that are applied throughout this Recommendation follows:
+
+Bits are packed into octets starting at the most significant bit. If a decoder is reading a sequence of bits from a bit-stream, it shall first read the most significant bit of the first octet, the next most significant bit, and so on, then proceed to the next octet.
+
+All multi-octet values shall be interpreted in a most-significant-first manner: the first octet of each value is most significant, and the last octet is the least significant.
+
+## 9.2 Page data structure
+
+The beginning of a MRC page is denoted by the Start of Page Marker Segment, followed by termination number, optional marker segments, page data and EOP. The optional marker segments are optional, unless otherwise stated. Their purpose is to provide insight into reproduction of the image and as such are typically not mandatory for image reproduction. Skipping of any unrecognized optional marker segment is appropriate. Page data consists of stripes 1 to N, as described in 9.2.1.
+
+Marker segments defined in this Recommendation and located between the Start of Page Marker Segment (SOP) and EOP marker shall have the following structure, which is consistent with that of the SOP:
+
+APP13 (X'FFED'), Length of segment, identifier, Optional length (if needed), parameters and/or segment data;
+
+where the Optional length is included when two octets are insufficient to represent the Length of segment and four octets are needed.
+
+In typical use, the 2-octet Length of segment should be sufficient to represent the length of the marker segment header and data, not including the 2-octet APP13 (X'FFED') marker itself; in which case the Optional length will be omitted. In cases where two octets are insufficient, the 2-octet Length of segment will take on a value of zero (0), and the Optional length will be used. If the 2-octet Length of segment is any value less than six (which is the clear minimal size of a marker segment for both the 2-octet length and the 4-octet identifier), then the Optional length is required. Values between one and five are reserved for future use.
+
+All APP13 (X'FFED') markers currently adhere to this rule with the exception of EOH, which does not include the data length in the Length of segment, but includes that length separately as the only parameter in the marker segment header.
+
+### 9.2.1 Start of page marker segment
+
+Start of Page Marker Segment has the following structure:
+
+MRC Magic Number, APP13, Length of segment, SOP ident, version, mask coder, image layer coders, mask resolution, width.
+
+The Start of Page Marker Segment is defined as follows:
+
+|                       |                    |                                                                                                                                                                                                                                                                                                                                                                                                                                |
+|-----------------------|--------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| MRC Magic number:     | 2 octets           | X'FFD8'                                                                                                                                                                                                                                                                                                                                                                                                                        |
+| APP13 Marker:         | 2 octets           | X'FFED'                                                                                                                                                                                                                                                                                                                                                                                                                        |
+| Length of Segment:    | 2 octets           | Length of segment in octets, MSB to LSB, as an integer value including the octet count itself but not including Magic Numbers or APP13.                                                                                                                                                                                                                                                                                        |
+| SOP Ident:            | 4 octets           | 'MRC0', represented as a 3-octet ASCII string plus an hexadecimal count (i.e., X'4D', X'52', X'43', X'00'). This X'00'-terminated string "MRC" uniquely identifies this marker segment as the start of page.                                                                                                                                                                                                                   |
+| Version:              | 1 octet            | Revision number, X'02' indicating revision "2".                                                                                                                                                                                                                                                                                                                                                                                |
+| Mode:                 | 1 octet            | X'01', indicating mode 1.0. Each mode identifies a different level of performance. Mode 1.0 identifies the base level of T.44 as defined by the contents of this Recommendation. Each incremental mode shall be defined in an Annex to this Recommendation and support the capabilities defined in this mode.                                                                                                                  |
+| Mask layer coders:    | 1 or more octet(s) | With value indicating coder as shown in Table 1. The identified coders may be used in any mask layer. The main mask layer is the only mask (even-numbered) layer permitted in this mode (Mode 1.0) and only one coder may be selected. Only one coder shall be used for the main mask (layer 2). The value shall be fixed to zero "0" in the event that there is no mask layer coder (i.e., no coded mask layer data present). |
+| Image layer coders:   | 1 or more octet(s) | With value indicating coders as shown in Table 2. The identified coders may be used in any image layer. Background and foreground are the only image (odd-numbered) layers permitted in Mode 1.0. Any one of the selected coder(s) may be used in an image layer. The value shall be fixed to zero "0" in the event that there is no image layer coder.                                                                        |
+| Main Mask resolution: | 2 octets           | Expressing vertical and horizontal resolution as a single integer value in units of pels/25.4 mm. Basic value is 200 pels/25.4 mm. The value shall be fixed to that of the image layer in the event that there is no coded mask data (layer) in the page.                                                                                                                                                                      |
+
+Page width: 4 octets Expressing page width as a single integer value. For pages with two or more layers, the main mask layer image width defines the page width in using units of the main mask resolution. For pages with only a single layer foreground or background image, no coded mask data, a virtual mask (i.e., a mask layer without coded data) shall be used to define the page width.
+
+**Table 1/T.44 – Mask (even-numbered layer) coder octet(s)**
+
+| Octet bit number                                                                                                                                                                                                                                                                       | Coder used                                         |
+|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------|
+| LSB 0                                                                                                                                                                                                                                                                                  | One-dimensional T.4 (MH) coding                    |
+| 1                                                                                                                                                                                                                                                                                      | Two-dimensional T.4 (MR) coding                    |
+| 2                                                                                                                                                                                                                                                                                      | T.6 (MMR) coding                                   |
+| 3                                                                                                                                                                                                                                                                                      | T.82 (JBIG1) coding applying ITU-T Rec. T.85       |
+| 4                                                                                                                                                                                                                                                                                      | T.88 (JBIG2) coding, Annex B/ T.44 is required     |
+| 5                                                                                                                                                                                                                                                                                      | Reserved                                           |
+| 6                                                                                                                                                                                                                                                                                      | Reserved                                           |
+| MSB 7                                                                                                                                                                                                                                                                                  | Extend, add another octet that follows immediately |
+| NOTE – New bi-level coders (i.e., a <del>5th</del> , 6th and 7th coder) would be assigned bit numbers 4, 5 and 6 respectively. Bit 7, the extend bit, would be set when adding another octet to accommodate additional coders, such as an 8th which would be assigned to bit number 8. |                                                    |
+
+**Table 2/T.44 – Image (odd-numbered layer) coder octet(s)**
+
+| Octet bit number                                                                                                                                                                                                                                                                                    | Coder used                                                                                   |
+|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------|
+| LSB 0                                                                                                                                                                                                                                                                                               | T.81 (JPEG) coding and ITU-T Rec. T.42/LAB                                                   |
+| 1                                                                                                                                                                                                                                                                                                   | T.82 (JBIG1) coding applying ITU-T Recs T.43 and T.42/LAB                                    |
+| 2                                                                                                                                                                                                                                                                                                   | T.45 "Run-length Colour Encoding" and ITU-T Rec. T.42/LAB, Annex B/T.44 is required (Note 1) |
+| 3                                                                                                                                                                                                                                                                                                   | T.81 (JPEG) coding and ITU-T Rec. T.42/YCC                                                   |
+| 4                                                                                                                                                                                                                                                                                                   | T.82 (JBIG1) coding applying ITU-T Recs T.43 and T.42/YCC                                    |
+| 5                                                                                                                                                                                                                                                                                                   | T.45 "Run-length Colour Encoding" and ITU-T Rec. T.42/YCC, Annex B/T.44 is required (Note 1) |
+| 6                                                                                                                                                                                                                                                                                                   | Reserved                                                                                     |
+| MSB 7                                                                                                                                                                                                                                                                                               | Extend, add another octet that follows immediately                                           |
+| NOTE 1 – Coding scheme(s) referencing this Note shall use the SLC (Start of Layer Coded data) marker segment, defined in the Layer Data Structure clause of Annex A/T.44. This means that Mode 1 shall not be used with the referencing coding scheme.                                              |                                                                                              |
+| NOTE 2 – New multi-level coders (i.e., <del>4th through</del> 7th coder) would be assigned bit numbers <del>2 through 6</del> respectively. Bit 7, the extend bit, would be set when adding another octet to accommodate additional coders, such as an 8th which would be assigned to bit number 8. |                                                                                              |
+| NOTE 3 – In Mode 1, the image code shall use either LAB (bits 0, 1 and 2) or YCC (bits 3, 4 and 5), but not both. Therefore, if any of bits 0, 1 or 2 is set, bits 3, 4 and 5 shall not be set. Conversely, if any of bits 3, 4 or 5 is set, bits 0, 1 and 2 shall not be set.                      |                                                                                              |
+
+### 9.2.2 Optional marker segments
+
+The optional marker segments are optional, unless otherwise stated. Their purpose is to provide insight into reproduction of the image and as such are typically not mandatory for image reproduction. Skipping of any unrecognized optional marker segment is appropriate.
+
+Optional marker segments (OMS<sub>x</sub>) consist of marker and associated parameters. The APP13 (X'FFED') marker initiates identification of the entry. Each optional marker segment is identified by the 3-octet ASCII string plus a hexadecimal count for 'MRCn'. The 'MRCn' identifier is a 4-octet value X'4D', X'52', X'43', X'n', where n may equal X'0A' (10) to a maximum of X'FE' (254). The optional marker segments are located after the Termination Number (TN).
+
+Each optional marker segment (OMS<sub>x</sub>) has the following structure: APP13 Marker (X'FFED'), Length of entry, OMS<sub>x</sub> ident (MRCn), Optional length (if needed), entry parameters and/or entry data.
+
+OMS<sub>x</sub> represents specific optional marker segments, where "x" is the value of a character used to distinguish each optional marker segment.
+
+#### 9.2.2.1 Layer base colour gamut range marker segment (OMS<sub>gl</sub>), MRC10 entry
+
+This entry specifies the gamut range information of LAB for indicating image layer (i.e., odd-numbered layers such as background and/or foreground layers) base colour. Structure of the OMS<sub>gl</sub> marker segment entry is as follows:
+
+APP13, length, OMS<sub>gl</sub> identifier, gamut range data for LAB.
+
+The OMS<sub>gl</sub> marker segment is defined as follows:
+
+|                               |           |                                                                                                                                                                                                                                                                                                                                                           |
+|-------------------------------|-----------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| APP13 marker:                 | 2 octets  | X'FFED'                                                                                                                                                                                                                                                                                                                                                   |
+| Length:                       | 2 octets  | Total entry field octet count, MSB to LSB, including the octet count itself, but excluding the APP13 marker.                                                                                                                                                                                                                                              |
+| OMS <sub>gl</sub> identifier: | 4 octets  | 'MRC10', represented as a 3-octet ASCII string plus an hexadecimal count (i.e., X'4D', X'52', X'43', X'0A'). This X'0A'-terminated string "MRC" uniquely identifies this entry marker as containing MRC information about optional gamut range data for LAB used to represent the layer base colour of the image layer in all stripes of the page.        |
+| Gamut range data:             | 12 octets | <p>The data field contains six two-octet signed integers. For example, the two-octet signed integer X'0064' represents 100.</p> <p>The example gamut range <math>L^* = [0, 100]</math>, <math>a^* = [-85, 85]</math>, and <math>b^* = [-75, 125]</math> would be represented by the code:</p> <p>X'0000', X'0064', X'0080', X'00AA', X'0060', X'00C8'</p> |
+
+The calculation from a real value  $L^*$  to an eight-bit value,  $L$ , is made as follows:
+
+$$L = (255/Q) \times L^* + P$$
+
+where the first integer of the first pair,  $P$ , contains the offset of the zero point in  $L^*$  in the eight most significant bits. The second integer of the first pair,  $Q$ , contains the span of the gamut range in  $L^*$ . Rounding to the nearest integer is performed. The second pair contains offset and range values for  $a^*$ . The third pair contains offset and range values for  $b^*$ . If the image is gray-scale ( $L^*$  only), the field still contains six integers, but the last four integers are ignored.
+
+NOTE – This description of gamut range is similar to APP1 (G3FAX1) defined in Annex E/T.4, except that 12-bit numbers are not defined.
+
+#### 9.2.2.2 Layer base colour illuminant marker segment (OMS<sub>i</sub>), MRC11 entry
+
+This entry specifies the illuminant information for indicating image layer (i.e., odd-numbered layers such as background and/or foreground layers) base colour. Structure of OMS<sub>i</sub> entry is as follows:
+
+APP13, length, OMS<sub>i</sub> ident, illuminant data.
+
+This option is for further study with the exception of the default case; the specification of the default illuminant, CIE Illuminant D50 for LAB colour space, may be added for information.
+
+For YCC colour space, D65 is the default illuminant, and the optional illuminant is not permitted. Therefore, this option is not applied for YCC colour space.
+
+The OMSi segment is defined as follows:
+
+|                       |          |                                                                                                                                                                                                                                                                                            |
+|-----------------------|----------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| APP13 marker:         | 2 octets | X'FFED'                                                                                                                                                                                                                                                                                    |
+| Length:               | 2 octets | Total entry field octet, MSB to LSB, count including the octet count itself, but excluding the entry marker.                                                                                                                                                                               |
+| OMSi identifier:      | 4 octets | 'MRC11', represented as a 3-octet ASCII string plus an hexadecimal count (i.e., X'4D', X'52', X'43', X'0B'). This X'0B'-terminated string "MRC" uniquely identifies this entry marker as containing MRC information about optional illuminant data for representing the layer base colour. |
+| Illuminant data:      | 4 octets | The data consist of a four-octet code identifying the illuminant. In the case of a CIE standard illuminant, the four-octet code is one of the following:                                                                                                                                   |
+| – CIE Illuminant D50: |          | X'00', X'44', X'35', X'30'                                                                                                                                                                                                                                                                 |
+| – CIE Illuminant D65: |          | X'00', X'44', X'36', X'35'                                                                                                                                                                                                                                                                 |
+| – CIE Illuminant D75: |          | X'00', X'44', X'37', X'35'                                                                                                                                                                                                                                                                 |
+| – CIE Illuminant SA:  |          | X'00', X'00', X'53', X'41'                                                                                                                                                                                                                                                                 |
+| – CIE Illuminant SC:  |          | X'00', X'00', X'53', X'43'                                                                                                                                                                                                                                                                 |
+| – CIE Illuminant F2:  |          | X'00', X'00', X'46', X'32'                                                                                                                                                                                                                                                                 |
+| – CIE Illuminant F7:  |          | X'00', X'00', X'46', X'37'                                                                                                                                                                                                                                                                 |
+| – CIE Illuminant F11: |          | X'00', X'46', X'31', X'31'                                                                                                                                                                                                                                                                 |
+
+NOTE – This description of illuminant is similar to APP1 (G3FAX2) defined in Annex E/T.4, except the colour temperature alone is not allowed.
+
+#### 9.2.2.3 Layer base colour gamut range marker segment (OMSgy), MRC09 entry
+
+This entry specifies the gamut range information of YCC for indicating image layer (i.e., odd-numbered layers such as background and/or foreground layers) base colour. Structure of the OMSgy marker segment entry is as follows:
+
+APP13, length, OMSgy identifier, gamut range data for YCC.
+
+The OMSgy marker segment is defined as follows:
+
+|                   |           |                                                                                                                                                                                                                                                                                                                                                   |
+|-------------------|-----------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| APP13 marker:     | 2 octets  | X'FFED'                                                                                                                                                                                                                                                                                                                                           |
+| Length:           | 2 octets  | Total entry field octet count, MSB to LSB, including the octet count itself, but excluding the APP13 marker.                                                                                                                                                                                                                                      |
+| OMSgy identifier: | 4 octets  | 'MRC9', represented as a 3-octet ASCII string plus an hexadecimal count (i.e., X'4D', X'52', X'43', X'09'). This X'0C'-terminated string "MRC" uniquely identifies this entry marker as containing MRC information about optional gamut range data for YCC used to represent the layer base colour of the image layer in all stripes of the page. |
+| Gamut range data: | 12 octets | The data field contains six two-octet signed integers. For example, the two-octet signed integer X'03E8' represents 1000. The example gamut range $Y = [0, 1.0]$ , $Cb = [-0.5, 0.5]$ , and $Cr = [-0.5, 0.5]$ would be represented by the code: X'0000', X'03E8', X'0080', X'03E8', X'0080', X'03E8'                                             |
+
+The calculation from a real value Y to an eight-bit value, NY, is made as follows:
+
+$$NY = (255/(Q/1000)) \times Y + P$$
+
+where the first integer of the first pair, P, contains the offset of the zero point in Y in the eight most significant bits. The second integer of the first pair, Q, contains an integer representation of the span of the gamut range in Y whereby the decimal point is implicitly in the third decimal place. Rounding to the nearest integer is performed. The second pair contains offset and range values for Cb. The third pair contains offset
+
+and range values for Cr.
+
+#### 9.2.2.4 MRC3 to MRC8 and 14 to MRC254 entry for future extensions
+
+The entries from MRC3 to MRC8 are to be reserved for future structural marker segments while MRC14 to MRC254 are to be reserved for other future use, such as optional marker segments, encoder marker segments (see Annex A) and reproduction information.
+
+### 9.2.3 TN (Termination Number)
+
+This is the JPEG EOI (End of Image) to alert decoders to the end of the initial JPEG application markers, registered per ITU-T Rec. T.86. The TN is located after the last SOP parameter (i.e., page width).
+
+TN: 2 octets X'FFD9'
+
+## 9.3 Stripe data structure
+
+The beginning of a stripe is denoted by the Start of Stripe Marker Segment, followed by stripe data.
+
+The first layer represented is the mask layer, followed by the background layer, and next the foreground layer (as appropriate). When there are two or more layers, the mask layer shall always be one of them. In the case of background only pixel data, no mask or foreground pixel data, the mask shall be fixed to "0". In the case of foreground only pixel data, no mask or background pixel data, the mask shall be fixed to "1".
+
+Start of Stripe Segment has the following structure:
+
+APP13, Length of segment, SOSSt ident, type of stripe, background layer base colour, foreground layer base colour, offset of background layer relative to upper left-hand pixel in the stripe, offset of foreground layer relative to upper left-hand pixel in the stripe, stripe height (number of lines), length of coded mask layer in number of octets.
+
+In Mode 1 (base mode) all SOSSt parameters must be present (i.e., layer base colour and offset values must be provided for both the foreground and background layers).
+
+The Start of Stripe Marker Segment is defined as follows:
+
+|                               |                    |                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
+|-------------------------------|--------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| APP13 marker:                 |                    | X'FFED'                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
+| Length of Segment:            | 2 octets           | Length of segment in octets, MSB to LSB, as an integer value not including APP13.                                                                                                                                                                                                                                                                                                                                                                               |
+| SOSSt Ident:                  | 4 octets           | 'MRC1', represented as a 3-octet ASCII string plus a hexadecimal count (i.e., X'4D', X'52', X'43', X'01'). This X'01'-terminated string "MRC" uniquely identifies this marker segment as the start of stripe.                                                                                                                                                                                                                                                   |
+| Type of stripe:               | 1 or more octet(s) | With value indicating stripe type as shown in Table 3. The corresponding bit shall be set to "1" for each layer present. When there are $\geq 2$ layers, the main mask layer must be one of the layers (bit 1 set to 1). A maximum of three layers may be present in this mode (Mode 1.0).                                                                                                                                                                      |
+| Background layer base colour: | 3 octets           | Colour encoded using OMSgl for LAB Colour Space or OMSgy for YCC colour space, and the layer base colour gamut range. The default color space is LAB, and if Image layer coder is defined the same colour space as that is used.<br><br>The value is white X'FF', X'80', X'60' for LAB Colour Space and X'FF', X'80', X'80' for YCC colour space unless otherwise specified. If available, custom gamut range may be applied from the optional marker segments. |
+| Foreground layer base colour: | 3 octets           | Colour encoded using OMSgl for LAB Colour Space or OMSgy for YCC colour space, and the layer base colour gamut range. The default colour space is LAB, and if Image layer coder is defined the same colour space as that is used.                                                                                                                                                                                                                               |
+
+|                             |          |                                                                                                                                                                                                                         |
+|-----------------------------|----------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+|                             |          | The value is black X'00', X'80', X'60' for LAB colour space and X'FF', X'80', X'80' for YCC colour space unless specified otherwise. If available, custom gamut range may be applied from the optional marker segments. |
+| Offset of background layer: | 8 octets | Horizontal offset, vertical offset as 2 integer values in mask layer units, as appropriate. Offsets are relative to stripe first scan line and left boundary.                                                           |
+| Offset of foreground layer: | 8 octets | Horizontal offset, vertical offset as 2 integer values in mask layer units, as appropriate. Offsets are relative to stripe first scan line and left boundary.                                                           |
+| Stripe height (lines):      | 4 octets | Height of stripe as an integer value. For images with two or more layers, the main mask layer height defines the stripe height. For single layer images, a virtual mask layer height defines the stripe height.         |
+| Mask layer length (octets): | 4 octets | Coded length of the main mask layer as an integer value, when present. This value must be set to zero (0) when there is no coded mask data.                                                                             |
+
+**Table 3/T.44 – Type of stripe**
+
+| Octet bit number                                                                                                                                                                                                                                                                              | Layer used                                         |
+|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------|
+| LSB 0                                                                                                                                                                                                                                                                                         | Background layer (layer 1)                         |
+| 1                                                                                                                                                                                                                                                                                             | Main mask layer (layer 2)                          |
+| 2                                                                                                                                                                                                                                                                                             | Foreground layer (layer 3)                         |
+| 3                                                                                                                                                                                                                                                                                             | Layer 4                                            |
+| 4                                                                                                                                                                                                                                                                                             | Layer 5                                            |
+| 5                                                                                                                                                                                                                                                                                             | Layer 6                                            |
+| 6                                                                                                                                                                                                                                                                                             | Layer 7                                            |
+| MSB 7                                                                                                                                                                                                                                                                                         | Extend, add another octet that follows immediately |
+| NOTE – Refer to Annex A for stripes with 4 or more layers. Layers above seven (7) would require an additional octet for representation. Bit 7, the extend bit, would be set when adding another octet to accommodate an additional layer such as Layer 8 which would be represented by bit 8. |                                                    |
+
+## 9.4 EOP (End of Page)
+
+This End of Page code indicates the end of MRC page.
+
+EOP: 4 octets X'FFD9', X'FFD9'
+
+## 9.5 Layer data structure
+
+Layers are coded using ITU-T coding methods indicated in the Start of Page Marker Segment. The coding method and resolution of the background and foreground layers are defined in the layer data. The resolutions of the background and foreground layers are restricted to ITU-T recommended values that must be integral factors of the main mask resolution. For example, if the mask resolution is 400 pels/25.4 mm, the background and foreground layer may each be either 100, 200 or 400 pels/25.4 mm.
+
+Main Mask resolution: 2 octets Expresses vertical and horizontal resolution as a single integer value in units of pels/25.4 mm. Basic value is 200 pels/25.4 mm. The value shall be fixed to that of the image layer in the event that there is no coded mask data (layer) in the page.
+
+Page width:
+4 octets
+
+Page width as a single integer value. For pages with two or more layers, the main mask layer image width defines the page width in units of main mask resolution. For pages with only a single layer foreground or background image, no coded mask data, a virtual mask (i.e., a mask layer without coded data) shall be used to define the page width.
+
+## 9.6 Data format summary
+
+### 9.6.1 High-level data format summary
+
+|           |              |                                |                         |                                   |
+|-----------|--------------|--------------------------------|-------------------------|-----------------------------------|
+| SOP       | SOP marker   | X'FFD8', X'FFED', Length, MRC0 |                         |                                   |
+|           | Parameters   | Version, Mode, ...             |                         |                                   |
+| TN        | X'FFD9'      |                                |                         |                                   |
+| OMSgl     | OMSgl marker | X'FFED', Length, MRC10         | parameters              |                                   |
+| OMSi      | OMSi marker  | X'FFED', Length, MRC11         | parameters              |                                   |
+| OMSGy     | OMSGy marker | X'FFED', Length, MRC9          | parameters              |                                   |
+| Page data | Stripe 1     | SOS <sub>t</sub>               | SOS <sub>t</sub> marker | X'FFED', Length, MRC1             |
+|           |              |                                | Parameters              | Type, B.G. layer base colour, ... |
+|           |              | Stripe data                    | Mask layer              | (layer data)                      |
+|           |              |                                | B.G. layer              | (layer data)                      |
+|           |              |                                | F.G. layer              | (layer data)                      |
+|           | ... ..       |                                |                         |                                   |
+|           | Stripe N     | SOS <sub>t</sub>               |                         |                                   |
+|           |              | Stripe data                    |                         |                                   |
+| EOP       | X'FFD9 FFD9' |                                |                         |                                   |
+
+### 9.6.2 Detail data format summary
+
+MRC Magic Number
+
+*SOP marker segment*
+
+APP13 marker
+
+Length of Segment
+
+MRC0 SOP identifier
+
+Version
+
+Mode
+
+Mask coder
+
+Image layer coder
+
+Mask resolution
+
+Page width
+
+TN
+
+*Layer base colour gamut marker segments*
+
+APP13
+
+Length of Segment
+
+MRC10 OMSgl identifier
+
+gamut range data
+
+#### *Layer base colour illuminant marker segments*
+
+APP13
+
+Length of Segment
+
+MRC11 OMSi identifier
+
+Illuminant data
+
+#### *OMSx (Optional marker segments)*
+
+APP13
+
+Length of Segment
+
+MRCn (n = 12 to 254) OMSx identifier
+
+optional maker segment data
+
+#### Stripe 1
+
+*SOS<sub>t</sub>* marker segment
+
+APP13 marker
+
+Length of Segment
+
+MRC1 SOS<sub>t</sub> identifier
+
+Type of stripe
+
+Background layer base colour
+
+Foreground layer base colour
+
+Offset of background layer
+
+Offset of foreground layer
+
+Stripe height (lines)
+
+Mask layer length (octets), when appropriate
+
+#### *Stripe data*
+
+*Mask layer*
+
+Layer coded data
+
+*Background layer*
+
+Layer coded data
+
+*Foreground layer*
+
+Layer coded data
+
+#### Stripe 2
+
+*SOS<sub>t</sub>* marker segment
+
+APP13 marker
+
+##### *Stripe data*
+
+*Mask layer*
+
+Layer coded data
+
+*Background layer*
+
+Layer coded data
+
+*Foreground layer*
+
+Layer coded data
+
+#### Stripe 3
+
+#### Stripe N
+
+EOP (X'FFD9', X'FFD9')
+
+# Annex A
+
+## Mixed Raster Content (MRC) Modes 2 and 3
+
+## A.1 Scope
+
+This annex defines Modes 2 and 3 to ITU-T Rec. T.44. Mode 2 adds SLC (start of layer coded data segment) support to the 3-layer model defined in Mode 1. Mode 3 adds SLC support and extends the model beyond three (3) layers to realize greater capability. Applications implementing Mode 2 shall support Mode 1 while applications supporting Mode 3 shall support modes 1 and 2. As with T.44 Mode 1, this annex does not define new encodings or resolutions. The method of image segmentation is beyond the scope of this annex, segmentation is left to the manufacturer's implementations.
+
+## A.2 References
+
+See the main body of this Recommendation.
+
+## A.3 Definitions
+
+The definitions of the main body of this Recommendation apply, plus the following definitions:
+
+**A.3.1 Encoder specific marker segment (EMSe):** Encoded as APP13 (X'FFED'), length of segment, EMSe ident (MRC12 to 254), parameters/data. This category of marker segments provides information that is specific to the encoding/decoding of the image. These marker segments are not always present since they are encoder dependent. When present, parsing of the EMSe is required for proper decoding of the layer data stream for which they are defined, unless otherwise stated.
+
+**A.3.2 End of header marker segment (EOH):** Encoded as APP13 (X'FFED'), length of segment, EOH ident (MRC255), parameters.
+
+**A.3.3 Start of layer coded marker segment (SLC):** Encoded as APP13 (X'FFED'), length of segment, SLC ident (MRC2), parameters.
+
+## A.4 Conventions
+
+See the main body of this Recommendation.
+
+## A.5 Image representation
+
+This annex includes description of syntax for encapsulating two or more ITU-T encodings on a single page. The base mode is mandatory and shall be supported by this mode.
+
+A page is composed from a set of page-wide stripes of image data. The stripes are transmitted sequentially from the top to the bottom of the page.
+
+The stripes are composed of one or more layers. Each layer is coded using a recommended ITU-T coding method.
+
+Information required to decode the page, such as coding types used within the layers, is specified within the page header (start of page marker segment). Stripe height is specified within the stripe header (start of stripe marker segment).
+
+Information required to decode a layer is included in the stripe header and the layer data.
+
+The main mask layer is transmitted first, followed by the background layer, followed by the foreground layer, and then any subsequent layer in increasing numeric order.
+
+Details of the syntax are described below.
+
+## **A.6 Stripe structure**
+
+Stripes are composed of one or more layers; background layer (layer 1), main mask layer (layer 2) foreground layer (layer 3), a series of overlay mask layers (even-numbered layers 4, 6, 8, ...) and image layers (odd-numbered layers 5, 7, ...). One or more images may be assigned a fixed colour value, while mask layers may be assigned a fixed bit value (i.e., 0, selecting the background or 1, selecting the foreground layer). Virtual mask layers and fixed value layers are not counted in classifying the stripe types as follows:
+
+N layer stripe (NLS)
+
+:  
+:
+
+Three-layer stripe (3LS)
+
+Two-layer stripe (LS)
+
+One-layer stripe (1LS)
+
+### **A.6.1 Three-layer stripe (3LS)**
+
+See the main body of this Recommendation.
+
+### **A.6.2 Two-layer stripe (2LS)**
+
+See the main body of this Recommendation.
+
+### **A.6.3 One-layer stripe (1LS)**
+
+See the main body of this Recommendation.
+
+### **A.6.4 N-layer stripe (NLS)**
+
+N-layer stripes (NLS), where N is an integer, are an extension to the basic structure of ITU-T Rec. T.44, as defined in this annex. The NLS contains more than three (3) layers; see Figure A.1. It provides a means to transfer one or more multi-level image layers (background, foreground, layer 5, layer 7, ...) and one or more bi-level mask layers (layers 2, 4, 6, ...) that define layer recombination on the same page. Beyond layer 1 (background), the layers occur in pairs, 2 and 3, 4 and 5, etc. The main mask layer (layer 2) must span the full dimension of the stripe while other layers (i.e., layer 1, 3, 4, 5, ...) may have an offset and dimensions that are less than those of the stripe. The offset and dimensions of the masks need not be the same as those of the corresponding image layers, see Figure A.1. This capability enables representation of richly coloured text, graphics, and line-art together with contone image using a combination of multi-level and bi-level coding methods.
+
+## **A.7 Image coding**
+
+### **A.7.1 Spatial resolution**
+
+The resolution of the main mask layer is fixed for the entire page and defines the maximum resolution for the page. In general it is possible to define lower spatial resolution for other layers. Spatial resolution of all layers must be integral factors of the main mask resolution. All resolutions used must be square (i.e., same horizontal and vertical values) and conform to ITU-T recommended values. The main mask resolution is specified in the page header. The resolution of other layers is specified in the stripe data stream.
+
+![Diagram illustrating the structure of an N-layer stripe. It shows a stack of layers labeled Layer 1 through Layer 7. Layer 1 is the base layer. Layers 2, 4, and 6 are mask layers, and Layers 3, 5, and 7 are image layers. The layers are shown as overlapping rectangles, indicating they are contained within the stripe boundaries. Vertical dashed lines define the stripe boundaries. A vertical ellipsis at the top indicates additional layers. The reference T0828660-99/d12 is at the bottom.](11edb7fcedf09ac6a817f8d7b8c61eec_img.jpg)
+
+Diagram illustrating the structure of an N-layer stripe. It shows a stack of layers labeled Layer 1 through Layer 7. Layer 1 is the base layer. Layers 2, 4, and 6 are mask layers, and Layers 3, 5, and 7 are image layers. The layers are shown as overlapping rectangles, indicating they are contained within the stripe boundaries. Vertical dashed lines define the stripe boundaries. A vertical ellipsis at the top indicates additional layers. The reference T0828660-99/d12 is at the bottom.
+
+**Figure A.1/T.44 – Mask and image layers in N-layer stripe**
+
+### A.7.2 Stripe width and layer width
+
+Stripes always span the entire width of a page. The main mask layer must always span the entire width.
+
+This method takes advantage of the image width and height data included in the layer data stream. Layers other than the main mask are not required to span the entire width. All layers must be fully contained within the boundaries of the stripe. The width value of the mask layers (even-numbered layers) and the width value of the corresponding image layers (odd-numbered layers) are independent. In addition, for layers other than the main mask layer, a horizontal offset may be used to select a starting point to the right of the left stripe boundary. The offset value of the mask layers (even-numbered layers) and the offset value of the corresponding image layers (odd-numbered layers) are independent. This offset is expressed in the main mask pixel units in the layer data. A simple stripe containing only background (e.g., JPEG data) or foreground (e.g., T.43 JBIG data) image data may use this feature also.
+
+### A.7.3 Stripe height and layer height
+
+To limit the data that must be buffered by an application, some applications may choose to limit the maximum height of two or more layer stripes (2LS to NLS) to a specified number of lines (in main mask layer resolution).
+
+One-layer stripes (1LS) are not required to conform to a maximum stripe height, and are only limited by page size. Layers without coded data (i.e., virtual mask layers and image layers with only base layer colour) are not to be counted when considering whether a stripe is a 1LS, 2LS, 3LS or NLS stripe.
+
+Stripe height and main mask layer height are always equal. Heights of layers, other than the main mask, are less than or equal to stripe heights. All layers must be fully contained within the boundaries of the stripe. The height value of the mask layers (even-numbered layers) and the height value of the corresponding image layers (odd-numbered layers) are independent. In addition, for layers other than the main mask layer, a vertical offset may be used to select a starting point below the first scan line of the stripe. The offset value of the mask layers (even-numbered layers) and the offset value of the corresponding image layers (odd-numbered layers) are independent. This offset is expressed relative to the first scan line at the top of the stripe and in the main mask pixel units. A simple stripe containing only background (e.g., JPEG) or foreground (e.g., T.43 JBIG) data may use this feature also.
+
+### A.7.4 Layer combination
+
+Image layers are rendered sequentially in ascending order of layer number (i.e., layer 1, then 3, then 5, ... then N). The background layer (i.e., layer 1), if present, shall be rendered first. Bi-level mask layers (even-numbered layers, such as layer 2) select pixels from their corresponding image layer (odd-numbered layer directly above the mask layer, such as layer 3) for rendering. A corresponding image layer pixel (directly above the mask layer pixel), or its layer base colour value, is selected when a mask pixel value is "1". The selected image layer pixel is rendered on top of any layer or layers that may have been previously rendered. A corresponding image layer pixel shall not be rendered when the mask pixel value is "0". The pixel from the layer or layer combination below the mask, or its layer base colour value, shall remain visible when the mask pixel value is "0". In the event of an image layer, or portion thereof, without a corresponding mask layer, the image layer shall be rendered on top of any previously rendered layers.
+
+## A.8 Layer transmission order
+
+In NLS, the bi-level main mask data is transmitted first, followed by the background (layer 1), foreground (layer 3), layer 4, layer 5, ..., layer N. In NLS without a background layer, the bi-level main mask image data is transmitted first, followed by the foreground layer, layer 4, layer 5, ..., layer N.
+
+## A.9 Data format
+
+### A.9.1 Overview
+
+The MRC image data consist of a series of: markers; parameters; data that specify the image coder, image size, bit resolution and spatial resolution; coded image data. The conventions of Annex B/T.81 are used broadly here. The JPEG registration body, per ITU-T Rec. T.86, has been used to register the marker code, APP13, classified as an application marker.
+
+~~Markers and/or marker segments used in association with the coding methods (i.e., encoder marker and/or marker segments) may be defined outside of this Recommendation (i.e., foreign encoder markers and/or marker segments). Foreign encoder markers and/or marker segments may be located within or outside of the data stream. A foreign encoder marker located outside the data stream shall be of the APPn form (i.e., an X'FF' octet followed by an octet not equal to X'00' or X'FF' and optionally preceded by extra X'FF' octet codes). Structure of a foreign encoder marker segment located outside the data stream shall be as follows:~~
+
+~~APPn, Length of segment, identifier, parameter and/or data.~~
+
+The MRC page structure for this application has the following elements: Parameters, markers, and entropy-coded data segments. Parameters and markers are often organized into marker segments. Parameters are integers of length ½, 1, 2 or more octets. Markers are assigned two or more octet codes, an X'FF' octet followed by an octet not equal to X'00' or X'FF' and optionally preceded by extra X'FF' octet codes. This application defines marker segments to denote the start of page (SOP), optional marker segments, the start of a stripe (SOSst), the start of layer coded data (SLC), encoder marker segments and end of header (EOH). The MRC Magic Number (JPEG SOI) is used immediately preceding the application marker as part of the SOP marker segment. The JPEG EOI is used as a termination number located directly after the last SOP parameter. The end of a page (EOP) is defined as X'FFD9FFD9'. These markers are inserted by the encoder, and understood by the decoder in addition to all markers used for the coding methods such as the SOI of ITU-T Rec. T.81.
+
+Markers and/or marker segments used in association with the coding methods (i.e., encoder marker and/or marker segments) may be defined outside of this Recommendation (i.e., foreign encoder markers and/or marker segments). Foreign encoder markers and/or marker segments may be located within or outside of the data stream. A foreign encoder marker located outside the data stream shall be of the APPn form (i.e., an X'FF' octet followed by an octet not equal to X'00' or X'FF' and optionally preceded by extra X'FF' octet codes). Structure of a foreign encoder marker segment located outside the data stream shall be as follows:
+
+APPn, Length of segment, identifier, parameter and/or data.
+
+### A.9.2 Page data structure
+
+The beginning of an MRC page is denoted by the Start of Page Marker Segment, followed by optional marker segment(s), Termination Number, page data, and EOP. The parameters of the optional marker segments are optional, unless otherwise stated. Their purpose is to provide insight into reproduction of the
+
+image and as such are typically not mandatory for image reproduction. Skipping of any unrecognized optional marker segment is appropriate. Page data consists of stripes 1 to n (where n is an integer), as described in the next subclause.
+
+#### A.9.2.1 Start of page marker segment
+
+Start of Page Marker Segment has the following structure:
+
+MRC Magic Number, APP13, Length of segment, SOP ident, version, mask coders, image layer coders, main mask resolution, width.
+
+The Start of Page Marker Segment is defined as follows:
+
+|                       |                    |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
+|-----------------------|--------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| MRC Magic Number:     | 2 octets           | X'FFD8'                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
+| APP13 marker:         | 2 octets           | X'FFED'                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
+| Length of Segment:    | 2 octets           | Length of segment in octets, MSB to LSB, as an integer value including the octet count itself but not including Magic Number or APP13.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
+| SOP Ident:            | 4 octets           | 'MRC0', represented as a 3-octet ASCII string plus an hexadecimal count (i.e., X'4D', X'52', X'43', X'00'). This X'00'-terminated string "MRC" uniquely identifies this marker segment as the start of page.                                                                                                                                                                                                                                                                                                                                                                                                                                            |
+| Version:              | 1 octet            | Revision number, X'00' indicting revision "0".                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
+| Mode:                 | 1 octet            | X'02', indicating Mode 2.0. Each mode identifies a different level of performance. Mode 2.0 identifies the SLC (start of layer coded marker segment) supported 3-layer mode of T.44 as defined by the contents of this annex. Applications supporting this mode shall support the capabilities defined in Mode 1.0.<br><br>X'03', indicating Mode 3.0. Each mode identifies a different level of performance. Mode 3.0 identifies the SLC (start of layer coded marker segment) supported N-layer mode of T.44 as defined by the contents of this annex. Applications supporting this mode shall support the capabilities defined in Modes 1.0 and 2.0. |
+| Mask coders:          | 1 or more octet(s) | With value indicating coder as shown in Table 1. The identified coders may be used in any mask layer. Only one coder shall be used in the main mask layer. Only one mask layer is present in Mode 2.0. More than one mask layer (i.e., main mask, layer 2, plus other even-numbered layers) may be present in Mode 3.0. The value shall be fixed to zero "0" in the event that there is no mask layer coder.                                                                                                                                                                                                                                            |
+| Image layer coders:   | 1 or more octet(s) | With value indicating coders as shown in Table 2. The identified coders may be used in any image layer. Only two image layers may be present in Mode 2.0. There is no restriction to the number of image layers that may be present in Mode 3.0 (i.e., image layers, layer 1, 3, plus other odd-numbered layers). The value shall be fixed to zero "0" in the event that there is no image layer coder.                                                                                                                                                                                                                                                 |
+| Main Mask resolution: | 2 octets           | Expressing vertical and horizontal resolution as a single integer value in units of pels/25.4 mm. Basic value is 200 pels/25.4 mm. The value shall be fixed to that of the image layer in the event that there is no coded mask data (layer) in the page.                                                                                                                                                                                                                                                                                                                                                                                               |
+
+|             |          |                                                                                                                                                                                                                                                                                                                                                                    |
+|-------------|----------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Page width: | 4 octets | Expressing page width as a single integer value. For pages with two or more layers, the main mask layer image width defines the page width in units of main mask resolution. For pages with only a single layer foreground or background image, no coded mask data, a virtual mask (i.e., a mask layer without coded data) shall be used to define the page width. |
+|-------------|----------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+
+#### **A.9.2.2 Optional marker segments**
+
+See the main body of this Recommendation.
+
+#### **A.9.2.3 TN (Termination Number)**
+
+See the main body of this Recommendation.
+
+### **A.9.3 Stripe data structure**
+
+The beginning of a stripe is denoted by the Start of Stripe Marker Segment, followed by stripe data.
+
+The first layer represented is the main mask (layer 2), followed by the background (layer 1), followed by the foreground (layer 3), followed by layer 4, followed by layer 5, ..., followed by layer N (as appropriate). When there are two or more layers, the main mask layer shall always be one of them. The stripe height is determined by the height of the first layer within the stripe.
+
+Start of Stripe marker segment has the following structure:
+
+APP13, Length of segment, SOSSt ident, type of stripe.
+
+The Start of Stripe Marker Segment is defined as follows:
+
+|                    |                    |                                                                                                                                                                                                                           |
+|--------------------|--------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| APP13 marker:      | 2 octets           | X'FFED'                                                                                                                                                                                                                   |
+| Length of Segment: | 2 octets           | Length of segment in octets, MSB to LSB, as an integer value not including APP13.                                                                                                                                         |
+| SOSSt Ident:       | 4 octets           | 'MRC1', represented as a 3-octet ASCII string plus an hexadecimal count (i.e., X'4D', X'52', X'43', X'01'). This X'01'-terminated string "MRC" uniquely identifies this marker segment as the start of stripe.            |
+| Type of stripe:    | 1 or more octet(s) | With value indicating stripe type as shown in Table 3. The corresponding bit shall be set to "1" for each layer present. When there are $\geq 2$ layers, the main mask layer shall be one of the layers (bit 1 set to 1). |
+
+### **A.9.4 EOP**
+
+See the main body of this Recommendation.
+
+### **A.9.5 Layer data structure**
+
+Layers are coded using ITU-T coding methods indicated in the Start of Page marker segment. A Start of Layer Coded Data (SLC) marker segment precedes the coded layer data. Parameters of the SLC include layer number, coder, resolution, coded image width and height, layer base colour and layer offset. One or more marker segments that contain encoding related parameters might follow the SLC. New encoder related marker segments may be defined as determined by encoding needs. They may be defined within or outside of this Recommendation. Those defined outside of this Recommendation are frequently referenced as foreign encoder marker segments. End of Header (EOH) marker segment terminates the SLC. The EOH contains the coded data length (octet count) of the layer. Encoder marker segments shall be located between the SLC and EOH. The resolutions of all layers are restricted to ITU-T recommended integral factors of the main mask resolution. For example, if the main mask resolution is 400 pels/25.4 mm, the other layers may each be either 100, 200 or 400 pels/25.4 mm.
+
+#### A.9.5.1 Start of Layer Coded Data (SLC) marker segment
+
+The start of layer coded data is uniquely identified by the SLC marker segment. This marker segment is mandatory for all layers. Structure of the SLC marker segment is as follows:
+
+APP13, length, SLC ident ('MRC2'), layer number, coder, resolution, layer width, layer height, layer base colour, layer offset.
+
+The marker segment is defined as follows:
+
+|                    |                  |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
+|--------------------|------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| APP13 marker:      | 2 octets         | X'FFED'                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
+| Length:            | 2 octets         | Total entry field octet count, MSB to LSB, including the octet count itself. It excludes the APP13 marker, any other marker segments, such as encoder related marker segments and the EOH.                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
+| SLC ident:         | 4 octets         | 'MRC2', represented as a 3-octet ASCII string plus an hexadecimal count (i.e., X'4D', X'52', X'43', X'02'). This X'02'-terminated string "MRC" uniquely identifies this marker segment as the start of layer coded data.                                                                                                                                                                                                                                                                                                                                                                                                                                            |
+| Layer number:      | 1 octet          | Identifies the number, ordering, of the layer. The first SLC after the SOS <sub>t</sub> shall always have an even layer number, it is always a mask layer (i.e., a coded mask layer or a virtual mask layer).                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
+| Coder:             | 2 or more octets | Identify presence of coder and coder used, as per Table A.1. Table A.1 identifies the coder by referencing Table 1 or Table 2 and specifying octet bit number via the hexadecimal value of octets 2-N.                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
+| Resolution:        | 2 octets         | Expressing vertical and horizontal resolutions as single integer values in units of pels/25.4 mm. Basic value is 200 pels/25.4 mm. For layers with no coded data, the value is set to that of the corresponding mask layer or image layer for image and mask layers respectively. For example, if layer three contains no coded data, then its resolution shall be set to that of layer 2, while if layer two contains no coded data, then its resolution shall be set to that of layer 1 or 3, whichever is present.                                                                                                                                               |
+| Layer width:       | 4 octets         | Width of coded image data (number of pixels) in the layer, in main mask layer resolution unit, as an integer value.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
+| Layer height:      | 4 octets         | Number of scan-lines of coded data in the layer, in main mask layer resolution unit, as an integer value. The stripe height is defined by the layer height contained in the first SLC after the SOS <sub>t</sub> .                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
+| Layer base colour: | 3 octets         | Colour encoded using OMS <sub>gl</sub> for LAB Colour Space or OMS <sub>gy</sub> for YCC colour space, and the layer base colour gamut range. The default colour space is LAB, and if Coder is defined the same colour space as that is used. The value is fixed to X'00', X'00', X'00' for mask layers (even-numbered layers) since these layers do not have colours.<br><br>For the Background layer (layer 1), the layer base colour is considered to be white X'FF', X'80', X'60' for LAB colour space and X'FF', X'80', X'80' for YCC colour space, unless specified otherwise. The layer base colour gamut and white point, per ITU-T Rec. T.42, are applied. |
+
+The optional marker segments, Layer Base Colour Gamut Range (OMSgl) for LAB or (OMSgy) for YCC and Layer Base Colour Illuminant (OMSi) for LAB shall be applied, if present.
+
+For Foreground layers (odd-numbered layers 3 to N), the layer base colour is considered to be black X'00', X'80', X'60' for LAB Colour Space and X'00', X'80', X'80' for YCC colour space, unless specified otherwise. The layer base colour gamut and white point, per ITU-T Rec. T.42, are applied. The optional marker segments, Layer Base Colour Gamut Range (OMSgl) for LAB or (OMSgy) for YCC and Layer Base Colour Illuminant (OMSi) for LAB shall be applied, if present.
+
+Offset: 8 octets
+
+Horizontal offset and vertical offset as 2 integer values in main mask layer units, as appropriate. Offsets are relative to stripe first scan line and left boundary. Both the horizontal and vertical offsets of the main mask layer (layer 2) are fixed to X'00', X'00', X'00', X'00'.
+
+**Table A.1/T.44 – Coder identification**
+
+| Octet 1            |           |                                                     | Octets 2..N          |
+|--------------------|-----------|-----------------------------------------------------|----------------------|
+| Octet 1 bit number | Bit value | Definition                                          | Hex value: 'XXX---X' |
+| 0                  | 0         | No coded data, ignore bit 1                         |                      |
+|                    | 1         | Bit 1 identifies coded data from Table 1 or Table 2 |                      |
+| 1                  | 0         | Octets 2-N define octet bit number from Table 1     |                      |
+|                    | 1         | Octets 2-N define octet bit number from Table 2     |                      |
+| 2-7                | Reserved  |                                                     |                      |
+
+#### A.9.5.2 Encoder related marker segments (EMSe)
+
+The encoder marker segments (EMSe) provide information that is specific to the encoding/decoding of the image. These marker segments are not always present since they are encoder dependent. When present, parsing of encoder marker segment(s) is required for proper decoding of the layer data stream for which they are defined, unless otherwise stated.
+
+Encoder related marker segments consist of marker and associated parameters/data. The APP13 (X'FFED') marker initiates identification of each entry. Each encoder related marker segment is identified by the 3-octet ASCII string plus an hexadecimal count for 'MRCn'. The 'MRCn' identifier is a 4-octet value X'4D', X'52', X'43', X'n', where n may equal X'0C' (12) to a maximum of X'FE' (254).
+
+Each encoder related marker segment has the following structure:
+
+APP13 Marker (X'FFED'), Length of entry, encoder marker segment ident (MRCn), Optional length (if needed), parameters and/or data.
+
+EMSe represents specific encoder marker segments, where "EMS" is replaced by an appropriate acronym used to distinguish each encoder marker segment.
+
+Specific encoder marker segments are defined elsewhere within this Recommendation or outside of this Recommendation. A foreign encoder marker segment shall also have the structure:
+
+APPn, Length of segment, identifier, parameter/data; where the APPn marker consists of an X'FF' octet followed by an octet not equal to X'00' or X'FF' and optionally preceded by extra X'FF' octet codes.
+
+#### A.9.5.3 End of Header (EOH) marker segment
+
+The EOH marker segment uniquely identifies the end of the SLC and any other marker segment(s) that may be present. This marker segment is mandatory. The EOH shall directly precede the coded data. Structure of the EOH marker segment is as follows:
+
+APP13, length, EOH ident ('MRC255') and coded data length.
+
+The marker segment is defined as follows:
+
+|                    |          |                                                                                                                                                                                                                |
+|--------------------|----------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| APP13 marker:      | 2 octets | X'FFED'                                                                                                                                                                                                        |
+| Length:            | 2 octets | Total entry field octet count, MSB to LSB, including the octet count itself. It excludes the APP13 marker.                                                                                                     |
+| EOH ident:         | 4 octets | 'MRC255', represented as a 3-octet ASCII string plus an hexadecimal count (i.e., X'4D', X'52', X'43', X'FF'). This X'FF'-terminated string "MRC" uniquely identifies this marker segment as the end of header. |
+| Coded data length: | 4 octets | Octet count of coded data in the layer.                                                                                                                                                                        |
+
+### A.9.6 Data format summary
+
+#### A.9.6.1 High-level data format summary
+
+|                  |                              |              |                                   |                                  |                                                                     |  |  |
+|------------------|------------------------------|--------------|-----------------------------------|----------------------------------|---------------------------------------------------------------------|--|--|
+| <b>SOP</b>       | X'FFD8' X'FFED' Length, MRC0 |              | Version, Mode, ...                |                                  |                                                                     |  |  |
+| <b>TN</b>        | X'FFD9'                      |              |                                   |                                  |                                                                     |  |  |
+| <b>OMSgl</b>     | X'FFED' Length, MRC10        |              | Gamut data for LAB                |                                  |                                                                     |  |  |
+| <b>OMSi</b>      | X'FFED' Length, MRC11        |              | Illuminant data for LAB           |                                  |                                                                     |  |  |
+| <b>OMSgy</b>     | X'FFED' Length, MRC9         |              | Gamut data for YCC                |                                  |                                                                     |  |  |
+| <b>Page data</b> | Stripe 1                     | <b>SOST</b>  | X'FFED' Length MRC1               |                                  | Type                                                                |  |  |
+|                  |                              | Layer 2 (L2) | <b>SLC</b> X'FFED' Length, MRC2   |                                  | Layer number, coder, res., width, height, layer base colour, offset |  |  |
+|                  |                              |              | <b>EOH</b> X'FFED' Length, MRC255 |                                  | coded data length                                                   |  |  |
+|                  |                              |              | coded data                        |                                  |                                                                     |  |  |
+|                  |                              | Stripe data  | L1                                | <b>SLC</b>                       |                                                                     |  |  |
+|                  |                              |              |                                   | <b>EMSe</b> X'FFED' Length, MRCn | Parameters/data                                                     |  |  |
+|                  |                              |              |                                   | <b>EOH</b>                       |                                                                     |  |  |
+|                  |                              |              |                                   | coded data                       |                                                                     |  |  |
+|                  |                              |              | L 3                               |                                  |                                                                     |  |  |
+|                  |                              |              | L 4                               |                                  |                                                                     |  |  |
+|                  |                              |              |                                   |                                  |                                                                     |  |  |
+|                  |                              |              | L N                               |                                  |                                                                     |  |  |
+|                  |                              |              |                                   |                                  |                                                                     |  |  |
+|                  | Stripe N                     | <b>SOST</b>  |                                   |                                  |                                                                     |  |  |
+|                  |                              | Stripe data  |                                   |                                  |                                                                     |  |  |
+| <b>EOP</b>       | X'FFD9FFD9'                  |              |                                   |                                  |                                                                     |  |  |
+
+#### A.9.6.2 Detail data format summary
+
+MRC Magic Number
+
+*SOP marker segment*
+
+APP13 marker
+
+Length of Segment
+
+MRC0 SOP identifier
+
+Version
+
+Mode
+
+Mask coder
+
+Image layer coder
+
+Main mask resolution
+
+Page width
+
+TN
+
+*Layer base colour Gamut marker segment*
+
+APP13
+
+Length of Segment
+
+MRC10 OMSgl identifier
+
+gamut range data
+
+*Layer base colour Illuminant marker segment*
+
+APP13
+
+Length of Segment
+
+MRC11 OMSi identifier
+
+illuminant data
+
+*OMSc (optional marker segments)*
+
+APP13
+
+Length of Segment
+
+MRCn (n = 12 to 254) identifier
+
+...
+
+Page data
+
+Stripe 1
+
+*SOS<sub>t</sub> marker segment*
+
+APP13 marker
+
+Length of Segment
+
+MRC1 SOS<sub>t</sub> identifier
+
+Type of stripe
+
+*Stripe data*
+
+*Mask layer*
+
+*SLC marker segment*
+
+APP13 marker
+
+Length of Segment
+
+MRC2 SLC identifier
+
+layer number
+
+coder
+
+Resolution
+
+Layer width
+
+Layer height
+
+Layer base colour
+
+Offset
+
+*Encoder marker segments*  
+ APP13 marker  
+ Length of Segment  
+ MRCn EMSe identifier  
+     Parameters/data  
+*EOH marker segment*  
+ APP13 marker  
+ Length of Segment  
+ MRC255 EOH identifier  
+     coded data length  
+     Layer coded data -----  
+*Background layer*  
+*SLC marker segment*  
+     :  
+     :  
+*Encoder marker segments*  
+     ...  
+     ...  
+*EOH marker segment*  
+     Layer coded data -----  
+*Foreground layer*  
+*SLC marker segment*  
+     :  
+     :  
+     :  
+*Encoder marker segments*  
+*EOH marker segment*  
+     Layer coded data -----  
+*Layer 4*  
+*SLC marker segment*  
+     :  
+     :  
+     :  
+*Encoder marker segments*  
+*EOH marker segment*  
+     Layer coded data -----  
+*Layer 5*  
+*SLC marker segment*  
+     :  
+     :  
+     :  
+*Encoder marker segments*  
+*EOH marker segment*  
+     Layer coded data -----  
+     :  
+     :  
+     :  
+*Layer N*  
+*SLC marker segment*  
+     :  
+     :  
+     :  
+*Encoder marker segments*  
+*EOH marker segment*  
+     Layer coded data -----
+
+Stripe 2
+
+*SOSSt marker segment*  
+ APP13 marker  
+ -----
+
+```
+
+Stripe data
+  Mask layer
+    Layer coded data -----
+  Background layer
+    Layer coded data -----
+  Foreground layer
+    Layer coded data -----
+  Layer 4
+    Layer coded data -----
+  Layer 5
+    Layer coded data -----
+    :
+    :
+  Layer N
+    Layer coded data -----
+Stripe 3
+  -----
+Stripe N
+  -----
+EOP (X'FFD9', X'FFD9')
+
+```
+
+# Annex B
+
+## MRC Mode 4 – Shared resources and colour tags
+
+## Introduction and background
+
+Improved compression, in terms of both reduced size and less error for lossy methods, is achieved when the compression method closely models and matches the data to be compressed. This is giving rise to a new wave of compression methods that have explicit models of some types of data. MPEG4 includes support for describing objects moving over a static background, something that is seen in video images of the world. ITU-T Rec. T.88 | ISO/IEC 14492 (JBIG2) represents scanned bi-level data by segmenting it into text, halftone, and other regions, and then using separate specialized compression methods to store these regions. The text regions are compressed by extracting symbols (individual text characters), and forming symbol dictionaries. The same symbol shapes (each one representing a text character from a certain font in a certain size) are used across multiple text regions and pages, to improve compression. Halftone regions are similarly represented using dictionaries of halftone patterns.
+
+Using these dictionaries, JBIG2 can achieve a large increase in compression relative to other bi-level image compression methods: 3-5 times greater compression than T.82 (JBIG1) or T.6 (MMR) is typical, and factors of over 20 times better compression than MMR have been observed.
+
+Of course, in order to achieve these large compression factors, each piece of data must be used to the maximum possible extent. This means that a single symbol dictionary must be used by multiple pages wherever possible, which necessarily has consequences for any system using JBIG2, as most systems have considered pages to be completely independent entities.
+
+An imaging model using JBIG2, such as MRC, should incorporate provisions for the use of shared data. This entails: having some way to define a shared resource, to be used by multiple coded entities (pages, stripes or layers); referring to that shared resource at the point where it is to be used; and later instructing the decoder that the resource is no longer required and may be flushed from memory. The shared data marker segment (SDM), introduced in this annex, is intended to provide this functionality.
+
+It should be noted that SDM is not restricted to JBIG2; its structure is flexible and could be used for other coding methods. For example, a set of JPEG Huffman tables could be stored in a shared resource and then used by multiple JPEG-coded layers, reducing file size. Similarly, a palette table could be defined once, then used by multiple T.43-coded layers.
+
+Another opportunity that is afforded by JBIG2 is improved compression of the foreground layer for documents containing coloured text. In most cases, if a document contains text, each individual text character is a single, flat, colour (e.g., black or red), and the number of such colours is limited. The foreground layer in this case looks like a number of coloured blobs, one for each character, each one having the shape of the corresponding character.
+
+This foreground layer can be compressed using a new method that takes advantage of the JBIG2 structure. If the mask layer is compressed using JBIG2 symbols and/or halftone regions, then decoding it essentially yields a sequence of (XPosition, YPosition, Symbol ID) triples. Each triple indicates that the symbol (from some dictionary) specified by "Symbol ID" should be drawn at the location "(X, Y)". Simply augmenting a text region triple with a fourth component, the colour of that individual character (sometimes called the symbols "colour tag"), allows storage of the foreground layer in a very small amount of space: using run-length coding on those colours. The total space taken by the foreground layer can be as small as a few tens of bytes.
+
+For example, if the mask layer contained two characters, an "R" in red and a "B" in blue, then the mask layer would decompress to:
+
+(100, 0, "R")
+
+(120, 0, "B")
+
+and the foreground layer would decompress to:
+
+(#7AD29C) [corresponding to CIELAB (48.0, 65.5, 48.0) using default gamut range]
+
+(#3A9B1D) [corresponding to CIELAB (23.1, 20.4, -52.1) using default gamut range]
+
+or some other suitable representation of the colours, such as indexes into a palette. Matching up the "R" symbol with the colour #7AD29C and drawing the symbol's shape in red gives the correct result. This is a single drawing operation, and is extremely efficient.
+
+Storing the foreground layer in this manner, using colour tags, allows very compact representation, and efficient decoding. However, since the mask layer is transmitted before the foreground layer, the decoder needs to be warned that the upcoming foreground layer is simply a list of colours (one per JBIG2 symbol in the mask layer), not a complete image. For this reason, we need to put a flag in the mask layer that warns the decoder "foreground is compressed using colour tags". The decoder can then defer drawing the mask until the foreground layer has also been decoded.
+
+## **B.1 Scope**
+
+This annex defines Mode 4 to ITU-T Rec. T.44, extending the MRC model to accommodate shared data and provisions for colour tags. The provisions of Mode 4 shall use the Mode 3 structure for implementation. Applications implementing Mode 4 shall support Modes 1, 2 and 3.
+
+## **B.2 References**
+
+The references of the main body of this Recommendation apply, plus the following.
+
+- ITU-T Recommendation T.45 (2000), *Run-length colour encoding*.
+- ITU-T Recommendation T.88 (2000) | ISO/IEC 14492:2001, *Information technology – Lossy/lossless coding of bi-level images*. (Commonly referred to as JBIG2 standard.)
+- ITU-T Recommendation T.89 (2001), *Application profiles for Recommendation T.88 – Lossy/lossless coding of bi-level images (JBIG2) for facsimile apparatus*.
+
+## B.3 Definitions
+
+The definitions in Annex A apply, plus the following additional definitions:
+
+**B.3.1 Create shared data marker segment (SDMc)**, encoded as APP13 (X'FFED'), Length of segment, SDM ident (MRC3), Optional length (if needed), parameters, shared data.
+
+**B.3.2 Colour-interpreter encoder marker segment (CLie)**, encoded as APP13 (X'FFED'), Length of segment, CLie ident (MRC13), parameters.
+
+**B.3.3 Disposition shared data marker segment (SDMd)**, encoded as APP13 (X'FFED'), Length of segment, SDMd ident (MRC4), parameters.
+
+**B.3.4 Generic region**: A region that codes pixels individually or in runs – a non-text or non-halftone region.
+
+**B.3.5 Halftone region**: A region containing halftone patterns that is coded by drawing a set of patterns into a bitmap, placing the patterns according to a halftone grid.
+
+**B.3.6 Meta-data**: Coding data external to the coded data stream that is required in the interpretation of the data stream and may be shared between pages and other document entities.
+
+**B.3.7 JBIG2 encoder marker segment (JB2e)**, encoded as APP13 (X'FFED'), Length of segment, JB2e ident (MRC12), parameters.
+
+**B.3.8 JBIG**: Joint Bi-level Image Experts Group and also shorthand for the encoding methods, JBIG1 and JBIG2 described in ITU-T Recs T.82 and T.88 respectively, which were defined by this group.
+
+**B.3.9 Refinement region**: A region that codes pixels by modifying a reference bitmap to produce an output bitmap.
+
+**B.3.10 Text region**: A region containing text characters that is coded by drawing a set of symbol instances into a bitmap.
+
+## B.4 Shared data
+
+JBIG2 compresses text regions by extracting symbols (individual text characters), and forming symbol dictionaries. The same symbol shapes (each one representing a text character from a certain font in a certain size) are used across multiple text regions and pages, to improve compression. Halftone regions are similarly represented using dictionaries of halftone patterns. The symbol dictionaries that are used over multiple regions and pages are referenced as shared data or shared resources. Using a single symbol dictionary over multiple pages, wherever possible, maximizes compression. The practice of using data over multiple pages contrasts with that of most systems where pages are considered to be completely independent entities.
+
+MRC makes provision for shared resources by introducing three new functions:
+
+- 1) The "create" function is used to establish a set of shared data. For future access, an ID (identification number) is assigned to the shared data when it is created/defined.
+
+There are four flags assigned to the "create" function to indicate the scope of application of the shared data:
+
+- a) The "global" flag is used to indicate that the shared data is available for application over the entire document, across multiple pages.
+- b) The "page" flag is used to indicate that the shared data is available for application over the rest of the current page, across multiple stripes.
+- c) The "stripe" flag is used to indicate that the shared data is available for application over the rest of the current stripe, across multiple layers.
+- d) The "layer" flag is used to indicate that the shared data is available for application over the current layer.
+
+The scope flags are intended to reduce the need for the "forget" function, see item 2 below. A scope of "global" implies that the shared data are to be retained until the end of the document data stream, or until a "forget" or "use/forget" function indicates that they may be discarded, whichever comes first. A scope of "page" implies that the shared data can be discarded once the next EOP is encountered, or a "forget" or "use/forget" function combination indicates that they may be discarded, whichever comes first. A scope of
+
+"stripe" implies that the shared data can be discarded once the next SOST is encountered, or a "forget" or "use/forget" function indicates that they may be discarded, whichever comes first. A scope of "layer" implies that the shared data can be discarded once the next SLC is encountered, or a "forget" or "use/forget" function combination indicates that they may be discarded, whichever comes first.
+
+- 2) The "forget" function is used to instruct the decoder that the identified share data is no longer required and may be flushed from memory. The "forget" function may be applied to one or more sets of shared data at a time by referencing one or more shared data ID.
+- 3) The "use" function is used to instruct the decoder to implement the identified share data in its decode operation. The "use" function may be applied to one or more sets of shared data at a time by referencing one or more shared data ID.
+
+The "use" and "forget" functions may be used independently or in combination with each other. When used in combination, the decoder is instructed to use the identified shared data resources for that layer and then flush from memory.
+
+## **B.5 Colour tags**
+
+In most cases, if a document contains text, each individual text character is a single, flat, colour (e.g., black or red), and the number of such colours is limited. The foreground layer in this case looks like a number of coloured blobs, one for each character, each one having the shape of the corresponding character.
+
+Colour tags can be taken advantage of for documents containing coloured text based on its: improved compression of foreground image layers (odd numbered layers  $\geq 3$ ), high speed encode and decode, ease of transcode to PDLs (printer description languages). If the corresponding mask layer is compressed using JBIG2, then decoding it essentially yields a sequence of (X, Y, Symbol ID) triples. Each triple indicates that the symbol (from some dictionary) specified by "Symbol ID" should be drawn at the location "(X, Y)". Simply augmenting this triple with a fourth component, the colour of that individual character (sometimes called the symbols "colour tag"), allows storage of the foreground layer in a very small amount of space. The foreground is represented by a T.45 run-length encoded list of colours, one per JBIG2 symbol in the mask layer. The colours may be represented by discrete colours (i.e., in CIELAB or ITU-YCC space), indexed colours, such as in palette tables or 1 bit/component RGB/CMY(K).
+
+A JBIG2-coded mask layer, within a stripe, might contain any combination of generic, halftone, refinement or text regions. Colour tags may only be used in association with JBIG2 mask layers, within a stripe, that contain only text regions (as colour tags "attach" to text). The foreground associated with a mask layer containing generic, refinement or halftone regions (or text and generic or text and halftone or text and refinement regions) shall be coded in the traditional MRC manner (i.e., using a multi-level coder). In other words, colour tags may only be used with foregrounds that are associated with mask layers within a stripe that contains only text regions.
+
+### **B.5.1 Mask generation (rendering) when JBIG2 encoded**
+
+ITU-T Rec. T.88 defines a collection of encoding parameters and components, which are mixed and matched to generate various application profiles. Generation of the mask layer data stream will require knowledge of the specific profile used during JBIG2 encoding. Additionally, if colour tags are used to encode the foreground associated with a JBIG2 encoded mask it will be necessary to know this information prior to decoding the mask.
+
+Clause B.6.3 makes provision for a T88Options function, used to notify the decoder of: the JBIG2 profile used, whether colour tags are used, any other parameters and/or data required to decode the data stream. The T88Options function uses a series of flag bits to identify each option.
+
+The "tags to follow" options flag bit is used to alert JBIG2 decoders to defer drawing the mask layer until the foreground layer has also been decoded. Given that mask layers are transmitted before the corresponding foreground layers, the decoder needs to be warned that the upcoming foreground layer is simply a list of colours (one per JBIG2 symbol in the mask layer), not a complete image. For this reason, the "tags to follow" flag bit is needed in the mask layer to warn the decoder that the foreground is compressed using colour tags. The decoder can then defer drawing the mask until the foreground layer has also been decoded.
+
+### B.5.2 Foreground generation (rendering) when mask is JBIG2 encoded
+
+If the mask layer is coded with JBIG2 and the foreground layer is coded with T.45, then the foreground image is the image obtained by:
+
+- decoding the text regions in the mask layer into a list of (X, Y, Symbol ID) triples; ordered as found in the JBIG2 data;
+- decoding the T.45 data into a list of corresponding colour values (CVAL); this list shall have the same number of elements as the list of triples;
+- matching each (X, Y, Symbol ID) triple with the corresponding colour value, giving a list of (X, Y, Symbol ID, CVAL) quads;
+- drawing these quads, in order from first to last, into the foreground image.
+
+Thus, if two symbol instances overlap, the colour from the latter symbol instance overwrites the colour from the first one.
+
+## B.6 Data format
+
+### B.6.1 Overview
+
+The second paragraph of A.9.1 is augmented to add shared data marker segment (SDMx) and a series of encoder marker segments (EMSe). The paragraph now reads as follows:
+
+The MRC page structure for this application has the following elements: parameters, markers, and entropy-coded data segments. Parameters and markers are often organized into marker segments. Parameters are integers of length  $\frac{1}{2}$ , 1, 2 or more octets. Markers are assigned two or more octet codes, an X'FF' octet followed by an octet not equal to X'00' or X'FF' and optionally preceded by extra X'FF' octet codes. This application accommodates marker segments to denote the start of page (SOP), additional optional marker segments (OMSx), the start of a stripe (SOST), the shared data marker segment (SDMx), the start of layer coded data (SLC), encoder related marker segments such as JBIG2 encoder marker segment (JB2e) and colour-interpreter encoder marker segment (CLie), and end of header marker segment (EOH). The SDMx, JB2e and CLie marker segments are defined in Annex B. The MRC Magic Number (i.e., JPEG SOI) is used immediately preceding the application marker as part of the SOP marker segment. Prior to the first SOST, the JPEG EOI is used as a termination number. The end of a page (EOP) is defined as X'FFD9FFD9'. These markers are inserted by the encoder, and understood by the decoder in addition to all markers used for the coding methods, such as SOS (start of scan) of ITU-T Rec. T.81.
+
+NOTE – Entire JBIG2 encoded data streams (i.e., including JBIG2 stripes and headers) are inserted directly following the EOH marker segment.
+
+### B.6.2 Start of page marker segment
+
+Start of page marker segment is defined per Mode 3 of Annex A with revision to the "Mode:" description to read as follows:
+
+|      |         |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
+|------|---------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Mode | 1 octet | X'04', indicating Mode 4. Each mode identifies a different level of performance. Mode 4 identifies mandatory writer and reader provision for SDMx (shared data marker segment) along with optional writer and mandatory reader provision for colour tags. The SDMx and colour tag provisions shall be used in conjunction with the SLC (start of layer coded marker segment) supported N-layer mode of T.44 as defined by Mode 3 of Annex A. Applications supporting Mode 4 shall support the capabilities defined in Mode 3. |
+|------|---------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+
+### B.6.3 JBIG2 encoder marker segment (JB2e), MRC12 entry
+
+This entry specifies parameters and/or data that are required in decoding a JBIG2 encoded data stream. It is used to specify the JBIG2 profile and whether colour tags or any future JBIG2 options are used in the data stream. The JBIG2 facsimile profiles are defined in ITU-T Rec. T.89. Structure of JB2e entry is as follows:
+
+APP13, length, JB2e ident., parameters/data.
+
+The JB2e encoder marker segment is defined as follows:
+
+|                    |                    |                                                                                                                                                                                                                           |
+|--------------------|--------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| APP13 marker:      | 2 octets           | X'FFED'                                                                                                                                                                                                                   |
+| Length of Segment: | 2 octets           | Length of segment in octets, MSB to LSB, as an integer value not including APP13.                                                                                                                                         |
+| JB2e Ident:        | 4 octets           | 'MRC12', represented as a 3-octet ASCII string plus an hexadecimal count (i.e., X'4D',X'52',X'43',X'0C'). This X'0C'-terminated string "MRC" uniquely identifies this marker segment as the JBIG2 encoder marker segment. |
+| T88Options:        | 1 or more octet(s) | With bit setting indicating applied option(s) flag, as shown in Table B.1. More than one bit may be set to indicate a combination of T88Options.                                                                          |
+
+**Table B.1/T.44 – T88Options octet(s)**
+
+| Octet bit number                                                                                                                                                                                                                                                                                                                                                                                                        | T88Options definition                                                                                                                                                                                                      |
+|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| LSB 0                                                                                                                                                                                                                                                                                                                                                                                                                   | JBIG2 Fax Profile 1 per ITU-T Rec. T.89                                                                                                                                                                                    |
+| 1                                                                                                                                                                                                                                                                                                                                                                                                                       | JBIG2 Fax Profile 2 per ITU-T Rec. T.89                                                                                                                                                                                    |
+| 2                                                                                                                                                                                                                                                                                                                                                                                                                       | JBIG2 Fax Profile 3 per ITU-T Rec. T.89                                                                                                                                                                                    |
+| 3                                                                                                                                                                                                                                                                                                                                                                                                                       | Reserved for JBIG2 Fax Profile to be defined in ITU-T Rec. T.89                                                                                                                                                            |
+| 4                                                                                                                                                                                                                                                                                                                                                                                                                       | Reserved for JBIG2 Fax Profile to be defined in ITU-T Rec. T.89                                                                                                                                                            |
+| 5                                                                                                                                                                                                                                                                                                                                                                                                                       | Reserved for JBIG2 Fax Profile to be defined in ITU-T Rec. T.89                                                                                                                                                            |
+| 6                                                                                                                                                                                                                                                                                                                                                                                                                       | Tags to follow – Used to alert the JBIG2 decoder to defer drawing the mask layer until the foreground layer has also been decoded. This is applied when the foreground colours are represented with colour tags. (Note 1.) |
+| MSB 7                                                                                                                                                                                                                                                                                                                                                                                                                   | Extend, add another octet that follows immediately                                                                                                                                                                         |
+| <p>NOTE 1 – If this bit is set, then JBIG2 Fax Profile 2 must be used (i.e., bit #1 must also be set).</p> <p>NOTE 2 – Bit 7, the extend bit, would be set when adding another octet to accommodate additional options, such as an 8th which would be assigned to bit number 8.</p> <p>NOTE 3 – Options for additional JBIG2 fax profiles will be added to bits 3 through 5 as they are defined in ITU-T Rec. T.89.</p> |                                                                                                                                                                                                                            |
+
+### **B.6.4 Shared data marker (SDMx) segment**
+
+This marker segment makes provision for the use of shared data, shared resources. It provides a means to: create/define a shared resource that is available to be used by multiple coded entities (i.e., pages, stripes or layers); refer to a shared resource at the point where it is to be used; instruct the decoder that the shared resource is no longer required and may be flushed from memory. In applications of JBIG2 encoding, the SDMx is typically used in mask layers (even numbered layers). The SDMx may be located prior to SOST marker segments (i.e., between the TN and the first SOST or between end of coded data stream for one stripe and the SOST for the next stripe), between SOST and SLC, between SLC and EOH, between end of coded data for one layer and SLC for the next layer, or between end of stripe data and EOP. More than one SDMx may appear at the same location within the page structure.
+
+Structure of each SDMx entry is as follows:
+
+APP13 (X'FFED'), length, SDMx ident, Optional length (if needed), parameters/data.
+
+SDMx represents specific shared data marker segments, where "x" is replaced by a specific character used to represent each shared data marker segment.
+
+#### B.6.4.1 Create shared data marker (SDMc) segment
+
+The SDMc is used in creating/defining a shared resource that is available to be used by multiple coded entities (i.e., pages, stripes or layers). Only one set of shared data may be created per SDMc.
+
+The Create Shared Data Marker Segment (SDMc) is defined as follows:
+
+|                                |                                       |                                                                                                                                                                                                                                                          |
+|--------------------------------|---------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| APP13 marker:                  | 2 octets                              | X'FFED'                                                                                                                                                                                                                                                  |
+| Length of Segment:             | 2 octets                              | Length of segment including length of shared data stream in octets, MSB to LSB, as an integer value not including APP13. Note that if two octets are insufficient, that the Optional length will be used, and this Length of Segment value will be zero. |
+| SDMc Ident:                    | 4 octets                              | 'MRC3', represented as a 3-octet ASCII string plus an hexadecimal count (i.e., X'4D',X'52',X'43',X'03'). This X'03'-terminated string "MRC" uniquely identifies this marker segment as the Create Shared Data Marker.                                    |
+| Optional length If (if needed) | 4 octets                              | Length of segment when two octets are not sufficient. If used, length of segment should have a value of zero.                                                                                                                                            |
+| ID:                            | 4 octets                              | With value providing unique identification of the shared data being created. IDs are unique, and as such their values shall not be reassigned within the document.                                                                                       |
+| Scope:                         | 1 octet                               | With value indicating breadth of application, as shown in Table B.2, of the shared data being created/defined.                                                                                                                                           |
+| Shared data stream             | (Length of segment – 11 or 15 octets) | Data stream being created by this marker segment and referenced by the above ID.                                                                                                                                                                         |
+
+**Table B.2/T.44 – Share data scope octet**
+
+| Octet value | Share data scope                                                                                                            |
+|-------------|-----------------------------------------------------------------------------------------------------------------------------|
+| 0           | Global – Shared data is available for application across the entire document (i.e., over more than one page).               |
+| 1           | Page – Shared data is available for application across an entire page (i.e., over more than one stripe).                    |
+| 2           | Stripe – Shared data is available for application across an entire stripe (i.e., over more than one layer).                 |
+| 3           | Layer – Shared data is available for application across an entire layer within a stripe (i.e., over one layer of a stripe). |
+| 4-255       | Reserved                                                                                                                    |
+
+#### B.6.4.2 Disposition Shared Data Marker (SDMd) segment
+
+The SDMd is used to: refer to a shared resource at the point where it is to be used; and/or instruct the decoder that the shared resource is no longer required and may be flushed from memory.
+
+The Disposition Shared Data Marker Segment (SDMd) is defined as follows:
+
+|                    |          |                                                                                                                                                                                                                                            |
+|--------------------|----------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| APP13 marker:      | 2 octets | X'FFED'                                                                                                                                                                                                                                    |
+| Length of Segment: | 2 octets | Length of segment in octets, MSB to LSB, as an integer value not including APP13 and the data when present. Note that two octets should be sufficient for the length, although the use of Optional length may still be used, if necessary. |
+
+|              |           |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
+|--------------|-----------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| SDMd Ident:  | 4 octets  | 'MRC4', represented as a 3-octet ASCII string plus an hexadecimal count (i.e., X'4D',X'52',X'43',X'04'). This X'04'-terminated string "MRC" uniquely identifies this marker segment as the Disposition Shared Data Marker.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
+| Disposition: | 1 octet   | With value indicating disposition, as shown in Table B.3, of the shared data referenced by the associated ID(s). The corresponding bit shall be set to "1" for each disposition type being applied. The "forget" and "use" dispositions may be used independently or in combination with each other. They may also apply to one or more "ID(s)" at a time. The "forget" disposition signals deletion of the shared data(s) referenced by the ID(s) below. The "Use" disposition signals application of the shared data(s) referenced by the ID(s) below. Combining the "forget" and "use" dispositions signals application and deletion at the end of the layer data stream of the shared data(s) referenced by the ID(s) below. |
+| Count:       | 2 octets  | With value indicating number of share data ID(s) being addressed by the "forget" and/or "use" disposition commands.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
+| ID:          | 4 × Count | With value(s) identifying the shared data being addressed by the disposition commands.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
+
+**Table B.3/T.44 – Share data disposition octet(s)**
+
+| Octet bit number                                                                                                        | Share data disposition                                                                                                                          |
+|-------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------|
+| LSB 0                                                                                                                   | Use – apply shared data to the following layer                                                                                                  |
+| 1                                                                                                                       | Forget – discard shared data: immediately, in the case that the "use" bit is not set; or after the layer, in the case that the "use" bit is set |
+| 2                                                                                                                       | Reserved                                                                                                                                        |
+| 3                                                                                                                       | Reserved                                                                                                                                        |
+| 4                                                                                                                       | Reserved                                                                                                                                        |
+| 5                                                                                                                       | Reserved                                                                                                                                        |
+| 6                                                                                                                       | Reserved                                                                                                                                        |
+| MSB 7                                                                                                                   | Reserved                                                                                                                                        |
+| NOTE – New disposition commands (i.e., 3rd through 8th command) would be assigned bit numbers 2 through 7 respectively. |                                                                                                                                                 |
+
+### B.6.5 Interpretation and representation of run-length colour encoded data
+
+Colours values (CVAL) from T.45 "Run-length Colour Encoding" encoded layers shall be interpreted using parameters of the Start of Layer Coded Data (SLC) marker segment, defined in A.9.5.1, the Colour-interpreter Encoder Marker Segment (CLIE) and any foreign encoder marker segments (i.e., encoder marker segments defined outside of this Recommendation) appearing between the SLC and EOH pair. The CLIE and foreign encoder marker segments shall and may, respectively, be included to provide complete colour interpretation. CLIE is specified within this annex while foreign encoder marker segments, used in the specification of gamut range, illuminant data and palette data, are defined outside of this annex. As per Annex A, the CLIE and any foreign encoder marker segments shall be located between the SLC and the EOH (End of Header) pair. The EOH is immediately followed by the run-length encoded layer data.
+
+There are a number of SLC parameters that are not required when ITU-T Rec. T.45 is used for colour value encoding. The value of the following unnecessary SLC parameters shall be set to "0" (zero) when ITU-T Rec. T.45 is used:
+
+- resolution;
+- width;
+- height;
+
+- layer base colour;
+- offset.
+
+The layer number and coder are the only SLC parameters that contain valid information when ITU-T Rec. T.45 is used.
+
+#### B.6.5.1 Colour-interpreter Encoder Marker Segment (CLie)
+
+The CLie identifies colour-encoding rules and is required to interpret T.45 encoded colour values (CVAL). The CLie may be used for the interpretation of colour values that have been encoded with other encoders. This marker segment is mandatory for all run-length colour encoded layers. Structure of the CLie is as follows:
+
+APP13, length, CLie ident. ('MRC13'), colour interpreter.
+
+The marker segment is defined as follows:
+
+|                    |          |                                                                                                                                                                                                                                              |
+|--------------------|----------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| APP13 marker:      | 2 octets | X'FFED'                                                                                                                                                                                                                                      |
+| Length of Segment: | 2 octets | Total entry field octet count, MSB to LSB, including the octet count itself. It excludes the APP13 marker.                                                                                                                                   |
+| CLie ident:        | 4 octets | 'MRC13', represented as a 3-octet ASCII string plus an hexadecimal count (i.e., X'4D',X'52',X'43',X'0D'). This X'0D'-terminated string "MRC" uniquely identifies this marker segment as the Colour-interpreter Encoder Marker Segment, CLie. |
+| ColorInterpreter:  | 1 octet  | With value indicating colour interpreter as shown in Table B.4. The interpreter specifies the colour space, bit depth (i.e., number of bits/component) and possibly other colour parameters such as gamut range, illuminant and white point. |
+
+**Table B.4/T.44 – Colour interpreter octet(s)**
+
+| Octet value                                                                                                                                                                                                                                                                                                      | Coder used                                                                                                                                                          |
+|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| 0                                                                                                                                                                                                                                                                                                                | Continuous-tone colour using CIELAB 8 bits/component per ITU-T Rec. T.42/LAB                                                                                        |
+| 1                                                                                                                                                                                                                                                                                                                | Continuous-tone colour using CIELAB 12 bits/component per ITU-T Rec. T.42/LAB                                                                                       |
+| 2                                                                                                                                                                                                                                                                                                                | Continuous-tone colour using ITU-YCC 8 bits/component per ITU-T Rec. T.42/YCC                                                                                       |
+| 3                                                                                                                                                                                                                                                                                                                | Continuous-tone colour using ITU-YCC 12 bits/component per ITU-T Rec. T.42/YCC                                                                                      |
+| 4-15                                                                                                                                                                                                                                                                                                             | Reserved                                                                                                                                                            |
+| 16                                                                                                                                                                                                                                                                                                               | 3-bit colour (1 bit/colour) using RGB primaries per 6.2.1/T.43 (Note 1)                                                                                             |
+| 17                                                                                                                                                                                                                                                                                                               | 3-bit colour (1 bit/colour) using CMY primaries per 6.2.1/T.43 (Note 1)                                                                                             |
+| 18                                                                                                                                                                                                                                                                                                               | 4-bit colour (1 bit/colour) using CMYK primaries per 6.2.1/T.43 (Note 1)                                                                                            |
+| 19-31                                                                                                                                                                                                                                                                                                            | Reserved                                                                                                                                                            |
+| 32                                                                                                                                                                                                                                                                                                               | Palettized colour image using the palette, LAB colour space and bit depth defined in the G3FAX6 marker segment per B.6.5.4.1, included within the same SLC (Note 2) |
+| 33                                                                                                                                                                                                                                                                                                               | Palettized colour image using the palette, YCC colour space and bit depth defined in the G3FAX6 marker segment per B.6.5.4.1, included within the same SLC (Note 2) |
+| 34-255                                                                                                                                                                                                                                                                                                           | Reserved                                                                                                                                                            |
+| NOTE 1 – 1 bit/component image data is treated as a special case of palette image representation in which colour values are specified by a bit plane stack of named colours, per 6.2.1/T.43, rather than an exact colour value. Palette tables are omitted in these cases since there is no actual palette data. |                                                                                                                                                                     |
+| NOTE 2 – G3FAX6 marker segment, as specified in B.6.5.4, is required for colour value interpretation.                                                                                                                                                                                                            |                                                                                                                                                                     |
+
+#### B.6.5.2 Coded image gamut range data
+
+The G3FAX1 marker segment for LAB, defined in E.6.6/T.4, or the G3FAX4 marker segment for LAB and YCC, similarly defined as G3FAX1 in E.6.6/T.4, shall be used in the interpretation of T.45 encoded colour values (CVAL) when it is present between the SLC and EOH. Presence of the G3FAX1 or the G3FAX4 is optional in the interpretation of T.45 encoded colour values (CVAL); however, if present, it shall be used. The G3FAX1 or the G3FAX4 may be used in the interpretation of colour values that have been encoded with other encoders. The G3FAX4 is similar to the OMSgl or OMGgy (layer base colour gamut range Optional Marker Segment) defined in 9.2.2.1 or 9.2.2.3, with the difference being that G3FAX4 is applied to the encoded data while OMSgl or OMGgy is applied to the layer base colour. The G3FAX4 marker segment is defined in B.6.5.2.1.
+
+The same colour space as that defined by coder in SLC is used.
+
+##### B.6.5.2.1 G3FAX4 marker segment
+
+The G3FAX4 marker segment, referenced in B.6.5.2 and similarly defined as G3FAX1 in E.6.6/T.4, is defined.
+
+###### G3FAX4 for gamut range for LAB and YCC
+
+X'FFE1' (APP1), length, G3FAX option identifier, gamut range data
+
+The above terms are defined as follows:
+
+Length: (Two octets) – Total APP1 field octet count including the octet count itself, but excluding the APP1 marker.
+
+FAX identifier: (Six octets) – X'47', X'33', X'46', X'41', X'58', X'04' – This X'04'-terminated string "G3FAX" uniquely identifies this APP1 marker as containing FAX information about optional gamut range data. (The FAX option identifiers are referred to as G3FAX1 – G3FAX255, meaning the octet-terminated string "G3FAX", X'nn').
+
+Gamut range data: (Twelve octets) – The data field contains six two-octet signed integers. For example:
+
+X'0064' represents 100.
+
+The calculation from a real value  $L^*$  to an eight bit value,  $L$ , is made as follows:
+
+$$L = (255/Q) \times L^* + P$$
+
+where the first integer of the first pair,  $P$ , contains the offset of the zero point in  $L^*$  in the eight most significant bits. The second integer of the first pair,  $Q$ , contains the span of the gamut range in  $L^*$ . Rounding to the nearest integer is performed. The second pair contains offset and range values for  $a^*$ . The third pair contains offset and range values for  $b^*$ . If the image is gray-scale ( $L^*$  only), the field still contains six integers, but the last four are ignored.
+
+The calculation from a real value  $Y$  to an eight-bit value,  $NY$ , is made as follows:
+
+$$NY = (255/(Q/1000)) \times Y + P$$
+
+where the first integer of the first pair,  $P$ , contains the offset of the zero point in  $Y$  in the eight most significant bits. The second integer of the first pair,  $Q$ , contains the 1000 times of the span of the gamut range in  $Y$ . Rounding to the nearest integer is performed. The second pair contains offset and range values for  $Cb$ . The third pair contains offset and range values for  $Cr$ .
+
+If the image is gray-scale ( $Y$  only), the field still contains six integers, but the last four integers are ignored.
+
+NOTE – This representation is in accord with ITU-T Rec. T.42. When the twelve bits/pel/component option is used, the range and offset are represented as above in eight bits.
+
+These represent the eight most significant bits of the zero-padded twelve-bit number in the offset, and the eight-bit integer range data as above. Appropriately higher precision calculation should be used.
+
+For example, the gamut range  $L^* = [0, 100]$ ,  $a^* = [-85, 85]$ , and  $b^* = [-75, 125]$  would be selected by the code:
+
+X'FFE1',X'0014',X'47',X'33',X'46',X'41',X'58',X'01',X'0000',X'0064',X'0080',X'00AA',X'0060',X'00C8'.
+
+The other example gamut range  $Y = [0, 1.0]$ ,  $C_b = [-0.5, 0.5]$ , and  $C_r = [-0.5, 0.5]$  would be represented by the code:
+
+X'FFE1',X'0014',X'47',X'33',X'46',X'41',X'58',X'01',X'0000', X'03E8', X'0080', X'03E8', X'0080', X'03E8'
+
+#### B.6.5.3 Coded image illuminant data
+
+The G3FAX2 marker segment for LAB, defined in E.6.7/T.4, or the G3FAX5 marker segment for LAB and YCC, similarly defined as G3FAX2 in E.6.6/T.4, shall be used in the interpretation of T.45 encoded colour values (CVAL) when it is present between the SLC and EOH. Presence of the G3FAX2 or the G3FAX5 is optional in the interpretation of T.45 encoded colour values (CVAL), however, if present it shall be used. The G3FAX2 or the G3FAX5 may be used for the interpretation of colour values that have been encoded with other encoders.
+
+The G3FAX5 is similar to the OMSi (layer base colour illuminant Optional Marker Segment) defined in 9.2.2.2/ T.44, with the difference being that G3FAX5 is applied to the encoded data while OMSi is applied to the layer base colour. The G3FAX5 marker segment is defined in B.6.5.3.1.
+
+The colour space to which G3FAX5 is applied, is only LAB. The default illuminant for YCC colour space is D65 and the other potential illuminant is not permitted for YCC colour space.
+
+##### B.6.5.3.1 G3FAX5 marker segment
+
+The G3FAX5 marker segment, referenced in B.6.5.3 and similarly defined as G3FAX2 in E.6.6/T.4, is defined.
+
+###### G3FAX5 for illuminant data for LAB
+
+X'FFE1' (APP1), length, G3FAX option identifier, illuminant data for LAB. This option is for further study with the exception of the default case; the specification of the default illuminant, CIE Illuminant D50, may be added for information.
+
+|                     |                                                                                                                                                                            |
+|---------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Length:             | (Two octets) – Total APP1 field octet count including the octet count itself, but excluding the APP1 marker.                                                               |
+| FAX identifier:     | (Six octets) – X'47', X'33', X'46', X'41', X'58', X'05'. This X'05'-terminated string "G3FAX" uniquely identifies this APP1 marker as containing optional illuminant data. |
+| Illuminant data:    | (Four octets) – The data consist of a four-octet code identifying the illuminant. In the case of a standard illuminant, the four octets are one of the following:          |
+| CIE Illuminant D50: | X'00', X'44', X'35', X'30'                                                                                                                                                 |
+| CIE Illuminant D65: | X'00', X'44', X'36', X'35'                                                                                                                                                 |
+| CIE Illuminant D75: | X'00', X'44', X'37', X'35'                                                                                                                                                 |
+| CIE Illuminant SA:  | X'00', X'00', X'53', X'41'                                                                                                                                                 |
+| CIE Illuminant SC:  | X'00', X'00', X'53', X'43'                                                                                                                                                 |
+| CIE Illuminant F2:  | X'00', X'00', X'46', X'32'                                                                                                                                                 |
+| CIE Illuminant F7:  | X'00', X'00', X'46', X'37'                                                                                                                                                 |
+| CIE Illuminant F11: | X'00', X'46', X'31', X'31'                                                                                                                                                 |
+| CIE Illuminant D50: | X'00', X'44', X'35', X'30'                                                                                                                                                 |
+
+In the case of a colour temperature alone, the four octets consist of the string 'CT', followed by the temperature of the source in degrees Kelvin represented by an unsigned two-octet integer. For example, a 7500°K illuminant is indicated by the code:
+
+X'FFE1', X'000C', X'47', X'33', X'46', X'41', X'58', X'02', X'43', X'54', X'1D4C'.
+
+#### B.6.5.4 Coded image palette data
+
+The G3FAX3 marker segment for LAB, defined in 7.2.2.4/ T.43, or the G3FAX6 marker segment for LAB and YCC, similarly defined as G3FAX3 in E.6.6/T.4, shall be used in the interpretation of T.45 encoded colour values (CVAL) when the CVALs are defined in terms of palette indices. The G3FAX3 or the G3FAX6 marker segment shall be present between the SLC and EOH when T.45 encoded CVALs are defined in terms of palette indices. The G3FAX3 or the G3FAX6 marker segment may be used in the interpretation of colour values that have been encoded with other encoders.
+
+The G3FAX6 marker segment is defined in B.6.5.4.1 A sample G3FAX6 code stream is also presented in B.6.5.4.2.
+
+##### B.6.5.4.1 G3FAX6 marker segment
+
+The G3FAX6 marker segment, referenced in B.6.5.4 and similarly defined in 7.2.2.4.1/T.43, is defined.
+
+###### "G3FAX6 entry for colour palette table"
+
+Colour palette table is specified using the Entry Marker X'FFE3' as follows:
+
+X'FFE3' (Entry Marker), length (4 octets), FAX identifier 3, table ID, tentries, colour table data.
+
+|                    |                                                                                                                                                                                                                                                                                                                                                                                                            |
+|--------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Length:            | (4 octets) – Total G3FAX3/G4FAX3 entry field octet count including the octet count itself, but excluding the Entry Marker.                                                                                                                                                                                                                                                                                 |
+| FAX identifier 3:  | (6 octets) – X'47', X'3m', X'46', X'41', X'58', X'06' (m = 3 or 4). This identifier specifies G3FAX6 entry.                                                                                                                                                                                                                                                                                                |
+| Table ID:          | (2 octets) – This specifies the type of colour palette table.<br>0: table specified in CIELAB or ITU-YCC space (8 bits/comp. precision).<br>4: table specified in CIELAB or ITU-YCC space (12 bits/comp. precision).                                                                                                                                                                                       |
+| Tentries:          | (4 octets) – It specifies the number of the colour palette table entries. This value should have the following relations:<br>N: Number of bits specified in G3FAX0/G4FAX0.<br>mb: octets/component in the table:<br>1: 8 bits precision<br>2: 12 bits precision<br>$2^{**}(N - 1) < \text{tentries} \leq 2^{**}N$<br>$\text{length} = 16 + (3 * \text{tentries} * \text{mb})$ .                            |
+| Colour table data: | ((3 * tentries * mb) octets) – This data consists of tentries colour palette table entries. Each table entry, which consists of 3 components, is in sequential order from index = 0 to index = tentries – 1. Each component consists of one or two octets value. Its length is specified by the table ID. Each component value is represented by CIELAB space or ITU-YCC space defined in ITU-T Rec. T.42. |
+
+##### B.6.5.4.2 Code string example
+
+The table below is an example of the code string for the following colour palette table. It assumes that the table is specified in CIELAB space (8 bit/comp. precision),  $t_{\text{entries}} = 236$ .
+
+Colour palette table example for 236 entries and 8 bit accuracy:
+
+| Index | Component values (8 bits) |     |     |
+|-------|---------------------------|-----|-----|
+|       | L*                        | a*  | b*  |
+| 0     | 255                       | 128 | 96  |
+| 1     | 0                         | 128 | 96  |
+| 2     | 128                       | 128 | 96  |
+| —     | —                         | —   | —   |
+| —     | —                         | —   | —   |
+| —     | —                         | —   | —   |
+| 235   | 220                       | 128 | 220 |
+
+Code String Example:
+
+|                                                  |                                                |                                                                          |                         |                                                     |
+|--------------------------------------------------|------------------------------------------------|--------------------------------------------------------------------------|-------------------------|-----------------------------------------------------|
+| Entry Marker<br>X'FFE3'                          | length<br>X'000002D4'                          | FAX-identifier " G3FAX '3' "<br>X'47', X'33', X'46', X'41', X'58', X'03' | table ID = 0<br>X'0000' | t <sub>entries</sub> = 236<br>X'000000EC'           |
+| index = 0<br>(255,128,96)<br>X'FF', X'80', X'60' | index = 1<br>(0,128,96)<br>X'00', X'80', X'60' | index = 2<br>(128,128,96)<br>X'80', X'80', X'60'                         | ...<br>...              | index = 235<br>(220,128,220)<br>X'DC', X'80', X'DC' |
+
+### B.6.6 Data format summary
+
+#### B.6.6.1 High level data format summary
+
+|                  |                                                  |             |                                            |             |                                                                                            |  |  |  |
+|------------------|--------------------------------------------------|-------------|--------------------------------------------|-------------|--------------------------------------------------------------------------------------------|--|--|--|
+| <b>SOP</b>       | X'FFD8 X'FFED', Length, MRC0, Version, Mode, ... |             |                                            |             |                                                                                            |  |  |  |
+| <b>TN</b>        | X'FFD9'                                          |             |                                            |             |                                                                                            |  |  |  |
+| <b>OMSGl</b>     | X'FFED', Length, MRC10, Gamut data for LAB       |             |                                            |             |                                                                                            |  |  |  |
+| <b>OMSi</b>      | X'FFED', Length, MRC11, Illuminant data for LAB  |             |                                            |             |                                                                                            |  |  |  |
+| <b>OMSGy</b>     | X'FFED', Length, MRC9, Gamut data for YCC        |             |                                            |             |                                                                                            |  |  |  |
+| <b>Page data</b> | Stripe 1                                         | <b>SOST</b> | X'FFED', Length, MRC1, Type, stripe height |             |                                                                                            |  |  |  |
+|                  |                                                  | Stripe data | Layer 2 (L2)                               | <b>SLC</b>  | X'FFED', Length, MRC2, Layer number, coder, res., width, height, layer base colour, offset |  |  |  |
+|                  |                                                  |             |                                            | <b>SDMc</b> | X'FFE3', Length, MRC3, Optional length, IDs, scope, data                                   |  |  |  |
+|                  |                                                  |             |                                            | <b>SDMd</b> | X'FFED', Length, MRC4, Disposition, count, IDs                                             |  |  |  |
+|                  |                                                  |             |                                            | <b>JB2e</b> | X'FFED', Length, MRC12, T88Options                                                         |  |  |  |
+|                  |                                                  |             |                                            | <b>EOH</b>  | X'FFED', Length, MRC255, coded data length                                                 |  |  |  |
+|                  |                                                  |             |                                            | Coded Data  |                                                                                            |  |  |  |
+|                  |                                                  |             | L1                                         |             |                                                                                            |  |  |  |
+|                  |                                                  |             | L3                                         | <b>SLC</b>  |                                                                                            |  |  |  |
+|                  |                                                  |             |                                            | <b>CLJe</b> | X'FFED', Length, MRC13, ColorInterpreter                                                   |  |  |  |
+|                  |                                                  |             |                                            | <b>EOH</b>  |                                                                                            |  |  |  |
+|                  |                                                  |             |                                            | Coded Data  |                                                                                            |  |  |  |
+|                  |                                                  |             | —                                          |             |                                                                                            |  |  |  |
+|                  |                                                  |             | —                                          |             |                                                                                            |  |  |  |
+|                  |                                                  |             | —                                          |             |                                                                                            |  |  |  |
+|                  |                                                  | LN          |                                            |             |                                                                                            |  |  |  |
+|                  | —                                                |             |                                            |             |                                                                                            |  |  |  |
+|                  | —                                                |             |                                            |             |                                                                                            |  |  |  |
+|                  | Stripe N                                         | <b>SOST</b> |                                            |             |                                                                                            |  |  |  |
+|                  |                                                  | Stripe data |                                            |             |                                                                                            |  |  |  |
+| <b>EOP</b>       | X'FFD9FFD9'                                      |             |                                            |             |                                                                                            |  |  |  |
+
+#### **B.6.6.2 Detail data format summary**
+
+MRC Magic Number
+
+*SOP marker segment*
+
+APP13 marker
+
+Length of Segment
+
+MRC0 SOP identifier
+
+Version
+
+Mode
+
+Mask coder
+
+Image layer coder
+
+Mask resolution
+
+Page width
+
+TN
+
+*Layer base colour Gamut optional (OMSgl) marker segment*
+
+APP13
+
+Length of Segment
+
+MRC10 OMSgl identifier
+
+gamut range data for LAB
+
+*Layer base colour Illuminant optional (OMSi) marker segment*
+
+APP13
+
+Length of Segment
+
+MRC11 OMSi identifier
+
+illuminant data
+
+*Optional marker segments*
+
+APP13
+
+Length of Segment
+
+MRC9 OMSgy identifier
+
+gamut range data for YCC
+
+APP13
+
+Length of Segment
+
+MRCn (n = 14 to 254) identifier
+
+...
+
+*Shared data marker (SDMc) segment*
+
+...
+
+*Shared data marker (SDMc) segment*
+
+...
+
+*Shared data marker (SDMd) segment*
+
+...
+
+Page data
+
+Stripe 1
+
+*SOSSt marker segment*
+
+APP13 marker
+
+Length of Segment
+
+MRC1 SOSSt identifier
+
+Type of stripe
+
+Stripe height
+
+*Stripe data*
+
+*Main Mask layer (Layer 2)*
+
+*SLC marker segment*
+
+APP13 marker
+
+Length of segment
+
+MRC2 SLC identifier
+
+layer number
+
+coder
+
+Resolution
+
+Layer width
+
+Layer height
+
+Layer base colour
+
+Offset
+
+*SDMc marker segment*
+
+APP13 marker
+
+Length of segment
+
+MRC3 SDMc identifier
+
+Optional length (if needed)
+
+ID
+
+Scope
+
+Shared data -----
+
+*SDMd marker segment*
+
+APP13 marker
+
+Length of segment
+
+MRC4 SDMd identifier
+
+Disposition
+
+Count
+
+ID
+
+*JBIG2 encoder marker (JB2e) segment*
+
+APP13 marker
+
+Length of segment
+
+MRC12 JB2e identifier
+
+T88Options
+
+*End of header (EOH) marker segment*
+
+APP13 marker
+
+Length of segment  
+ MRC255 EOH identifier  
+     coded data length  
+ Layer coded data -----  
+*Background layer*  
+     *SLC marker segment*  
+         :  
+         :  
+     *Encoder marker segments*  
+         ...  
+         ...  
+     *EOH marker segment*  
+     Layer coded data -----  
+*Foreground layer*  
+     *SLC marker segment*  
+         :  
+         :  
+     *CLLe marker segments*  
+         :  
+     *G3FAX4 marker segments*  
+         :  
+     *G3FAX5 marker segments*  
+         :  
+     *EOH marker segment*  
+     Layer coded data -----  
+ Layer 4  
+     *SLC marker segment*  
+         :  
+         :  
+     *SDMd marker segment*  
+         ...  
+     *JBIG2 encoder marker (JB2e) segment*  
+     *EOH marker segment*  
+     Layer coded data -----  
+ Layer 5  
+     *SLC marker segment*  
+         :  
+         :  
+     *CLLe marker segments*  
+     *G3FAX6 marker segments*  
+         :
+
+*EOH marker segment*  
+ Layer coded data -----  
+ :  
+ :  
+*Layer N*  
+*SLC marker segment*  
+ :  
+ :  
+*SDMc marker segments*  
+ ...  
+*EMSe marker segments*  
+*EOH marker segment*  
+ Layer coded data -----  
+*SDMd marker segments*  
+ ...
+
+Stripe 2
+
+*SOS<sub>t</sub> marker segment*  
+ APP13 marker  
+ -----  
+*Stripe data*  
+*Main Mask layer (Layer 2)*  
+ Layer coded data -----  
+*Background layer*  
+ Layer coded data -----  
+*Foreground layer*  
+ Layer coded data -----  
+*Layer 4*  
+ Layer coded data -----  
+*Layer 5*  
+ Layer coded data -----  
+ :  
+ :  
+*Layer N*  
+ Layer coded data -----
+
+Stripe 3
+
+-----
+
+Stripe n
+
+-----  
+*SDMd marker segment*  
+*EOP (X'FFD9', X'FFD9')*
+
+
+
+## SERIES OF ITU-T RECOMMENDATIONS
+
+|                 |                                                                                             |
+|-----------------|---------------------------------------------------------------------------------------------|
+| Series A        | Organization of the work of ITU-T                                                           |
+| Series D        | General tariff principles                                                                   |
+| Series E        | Overall network operation, telephone service, service operation and human factors           |
+| Series F        | Non-telephone telecommunication services                                                    |
+| Series G        | Transmission systems and media, digital systems and networks                                |
+| Series H        | Audiovisual and multimedia systems                                                          |
+| Series I        | Integrated services digital network                                                         |
+| Series J        | Cable networks and transmission of television, sound programme and other multimedia signals |
+| Series K        | Protection against interference                                                             |
+| Series L        | Construction, installation and protection of cables and other elements of outside plant     |
+| Series M        | Telecommunication management, including TMN and network maintenance                         |
+| Series N        | Maintenance: international sound programme and television transmission circuits             |
+| Series O        | Specifications of measuring equipment                                                       |
+| Series P        | Telephone transmission quality, telephone installations, local line networks                |
+| Series Q        | Switching and signalling                                                                    |
+| Series R        | Telegraph transmission                                                                      |
+| Series S        | Telegraph services terminal equipment                                                       |
+| <b>Series T</b> | <b>Terminals for telematic services</b>                                                     |
+| Series U        | Telegraph switching                                                                         |
+| Series V        | Data communication over the telephone network                                               |
+| Series X        | Data networks, open system communications and security                                      |
+| Series Y        | Global information infrastructure, Internet protocol aspects and next-generation networks   |
+| Series Z        | Languages and general software aspects for telecommunication systems                        |
\ No newline at end of file
diff --git a/marked/T/T-REC-T.5-199802-I_PDF-E/187bba66c887c745c512add37a577c5e_img.jpg b/marked/T/T-REC-T.5-199802-I_PDF-E/187bba66c887c745c512add37a577c5e_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..c3c9be7d9ab9dee76086eca12d78c4b07e76f5bd
--- /dev/null
+++ b/marked/T/T-REC-T.5-199802-I_PDF-E/187bba66c887c745c512add37a577c5e_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:52a5ee39f56cbf42a5c4e519666f5c8f69b548c4604b8e9c280aa9a8c4b4d342
+size 42791
diff --git a/marked/T/T-REC-T.5-199802-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/T/T-REC-T.5-199802-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..6e23e97e099558d9639b8864701319fab67aa894
--- /dev/null
+++ b/marked/T/T-REC-T.5-199802-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:48ce47bd59c13dc75ff017f6d8ef768ba3e0d0826c9df5894f913190598f3ce2
+size 8215
diff --git a/marked/T/T-REC-T.5-199802-I_PDF-E/69b7bd65e85cdef6fdd7fb0a8194257c_img.jpg b/marked/T/T-REC-T.5-199802-I_PDF-E/69b7bd65e85cdef6fdd7fb0a8194257c_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..60e878bb1cf71f3775da465de2129c20ae97e631
--- /dev/null
+++ b/marked/T/T-REC-T.5-199802-I_PDF-E/69b7bd65e85cdef6fdd7fb0a8194257c_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:ef13bbdde423f1d35676e813512f5dabe95e27f714c1fea91d33a96db6c133ad
+size 47238
diff --git a/marked/T/T-REC-T.5-199802-I_PDF-E/6ca05954842b17f14dfd52f26b9d43d2_img.jpg b/marked/T/T-REC-T.5-199802-I_PDF-E/6ca05954842b17f14dfd52f26b9d43d2_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..b76f31b1e8dd8aae037bce5eebed938c16f3c7a0
--- /dev/null
+++ b/marked/T/T-REC-T.5-199802-I_PDF-E/6ca05954842b17f14dfd52f26b9d43d2_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:902c25f65c7bfa69f9db1aac6d1f89b32231790387265ba935c10fc0ffe3570e
+size 25063
diff --git a/marked/T/T-REC-T.5-199802-I_PDF-E/76b0cd79baaedd942af4dc42f2e764b8_img.jpg b/marked/T/T-REC-T.5-199802-I_PDF-E/76b0cd79baaedd942af4dc42f2e764b8_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..31ea0dde70136d7a74fd883689ec911d30f59e48
--- /dev/null
+++ b/marked/T/T-REC-T.5-199802-I_PDF-E/76b0cd79baaedd942af4dc42f2e764b8_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:a95b73d0cf8e9b17ff2436df5ce096b630ab1f60a128ca6612bf23f527dfa626
+size 62946
diff --git a/marked/T/T-REC-T.5-199802-I_PDF-E/8c348bf9c2c81b018017ae1d19506a9a_img.jpg b/marked/T/T-REC-T.5-199802-I_PDF-E/8c348bf9c2c81b018017ae1d19506a9a_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..fdb9eb3dd8afa3b5a01b25ad909c5c77d09d2de3
--- /dev/null
+++ b/marked/T/T-REC-T.5-199802-I_PDF-E/8c348bf9c2c81b018017ae1d19506a9a_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:599157abdedfaa6989b176c20d46789fb48f4bef4913618a3a0545b4d5d102ae
+size 35892
diff --git a/marked/T/T-REC-T.5-199802-I_PDF-E/8fbdfc3d17fb1dae7b2d8f5a287fa9fc_img.jpg b/marked/T/T-REC-T.5-199802-I_PDF-E/8fbdfc3d17fb1dae7b2d8f5a287fa9fc_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..43eaaf94ebbf25e1371a57f022f34b1a3b8d6d7a
--- /dev/null
+++ b/marked/T/T-REC-T.5-199802-I_PDF-E/8fbdfc3d17fb1dae7b2d8f5a287fa9fc_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:57530a32f4fdd5dcbaf9ac086029c523ee8d6f1f62f929dc5b9ad153ccc24439
+size 64672
diff --git a/marked/T/T-REC-T.5-199802-I_PDF-E/9870bf462aa0d916a16d14b5a100c60a_img.jpg b/marked/T/T-REC-T.5-199802-I_PDF-E/9870bf462aa0d916a16d14b5a100c60a_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..82a75908aa3a62d72505eebf3bd236d50abfd6be
--- /dev/null
+++ b/marked/T/T-REC-T.5-199802-I_PDF-E/9870bf462aa0d916a16d14b5a100c60a_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:302ef9fbb4ebe6d3b7ad3054359511c13a9315917780e8c456cc3685f1d63eeb
+size 30716
diff --git a/marked/T/T-REC-T.5-199802-I_PDF-E/9a5927586a691c4908aa2cf98bd47ebb_img.jpg b/marked/T/T-REC-T.5-199802-I_PDF-E/9a5927586a691c4908aa2cf98bd47ebb_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..120ee3762c2c6575dbfbe6b8b98504767a037143
--- /dev/null
+++ b/marked/T/T-REC-T.5-199802-I_PDF-E/9a5927586a691c4908aa2cf98bd47ebb_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:1b88530d431b2c27088d940e4767fd73790c0ff57a7cce1187e3db28841006c0
+size 17809
diff --git a/marked/T/T-REC-T.5-199802-I_PDF-E/a234352dfaccdc24745c88eef7724cc6_img.jpg b/marked/T/T-REC-T.5-199802-I_PDF-E/a234352dfaccdc24745c88eef7724cc6_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..fc606b3d3c2718446aa1dd8dcc8ef08aeed097b1
--- /dev/null
+++ b/marked/T/T-REC-T.5-199802-I_PDF-E/a234352dfaccdc24745c88eef7724cc6_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:e40fe7beae626fac5594ea6ccbcfcc5f492536bf1ac8b260b4087155dcb6c46b
+size 38106
diff --git a/marked/T/T-REC-T.5-199802-I_PDF-E/af7916c89a458fdab6c3f443217388ae_img.jpg b/marked/T/T-REC-T.5-199802-I_PDF-E/af7916c89a458fdab6c3f443217388ae_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..6f13997243400735ec559c6c8d3daaca895d67ec
--- /dev/null
+++ b/marked/T/T-REC-T.5-199802-I_PDF-E/af7916c89a458fdab6c3f443217388ae_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:344ef9552afd7fd5e4796f097d0e0b440382361d16e1559dcb67b684cd6f8b45
+size 62015
diff --git a/marked/T/T-REC-T.5-199802-I_PDF-E/dcf37c460c66ec011dbe6ca08de44ff9_img.jpg b/marked/T/T-REC-T.5-199802-I_PDF-E/dcf37c460c66ec011dbe6ca08de44ff9_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..b09752f04ba893fb6a3774ee7619229ca466309f
--- /dev/null
+++ b/marked/T/T-REC-T.5-199802-I_PDF-E/dcf37c460c66ec011dbe6ca08de44ff9_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:913271d6dc8bb0120a435d7aab3bb2706233c8254339a07cb72749241e99ad1c
+size 91824
diff --git a/marked/T/T-REC-T.5-199802-I_PDF-E/e451401f8fa77b466f401d5fce15b26c_img.jpg b/marked/T/T-REC-T.5-199802-I_PDF-E/e451401f8fa77b466f401d5fce15b26c_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..6e26cd51bd7b204110209184146112273516a89f
--- /dev/null
+++ b/marked/T/T-REC-T.5-199802-I_PDF-E/e451401f8fa77b466f401d5fce15b26c_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:39b966cfc3d8a2962b6b727b5a7e5eb9546c5c12ede4c57e1840c7f6a03ef539
+size 33292
diff --git a/marked/T/T-REC-T.5-199802-I_PDF-E/fa01531ea2c45beeb4036005da3037a4_img.jpg b/marked/T/T-REC-T.5-199802-I_PDF-E/fa01531ea2c45beeb4036005da3037a4_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..9fd29d77c2b876ca934267615da8fc4eb67b5ca8
--- /dev/null
+++ b/marked/T/T-REC-T.5-199802-I_PDF-E/fa01531ea2c45beeb4036005da3037a4_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:3674e01eb2364e9c2ad4a3e0d139b2096ac235212756d6b6053c92b010496f13
+size 92509
diff --git a/marked/T/T-REC-T.5-199802-I_PDF-E/raw.md b/marked/T/T-REC-T.5-199802-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..273c1399d609cdeb11122ab41bbbc14b753b7e6f
--- /dev/null
+++ b/marked/T/T-REC-T.5-199802-I_PDF-E/raw.md
@@ -0,0 +1,1410 @@
+
+
+![ITU logo: a globe with the letters ITU inside, and a lightning bolt symbol below it.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg)
+
+ITU logo: a globe with the letters ITU inside, and a lightning bolt symbol below it.
+
+INTERNATIONAL TELECOMMUNICATION UNION
+
+# ITU-T
+
+TELECOMMUNICATION  
+STANDARDIZATION SECTOR  
+OF ITU
+
+# G.511
+
+(02/98)
+
+SERIES G: TRANSMISSION SYSTEMS AND MEDIA,  
+DIGITAL SYSTEMS AND NETWORKS
+
+Testing equipments
+
+# --- **Test methodology for Group 3 facsimile processing equipment in the Public Switched Telephone Network**
+
+ITU-T Recommendation G.511
+
+(Previously CCITT Recommendation)
+
+---
+
+## ITU-T G-SERIES RECOMMENDATIONS **TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS**
+
+|                                                                                                                                              |             |
+|----------------------------------------------------------------------------------------------------------------------------------------------|-------------|
+| INTERNATIONAL TELEPHONE CONNECTIONS AND CIRCUITS                                                                                             | G.100–G.199 |
+| <b>INTERNATIONAL ANALOGUE CARRIER SYSTEM</b>                                                                                                 |             |
+| GENERAL CHARACTERISTICS COMMON TO ALL ANALOGUE CARRIER-TRANSMISSION SYSTEMS                                                                  | G.200–G.299 |
+| INDIVIDUAL CHARACTERISTICS OF INTERNATIONAL CARRIER TELEPHONE SYSTEMS ON METALLIC LINES                                                      | G.300–G.399 |
+| GENERAL CHARACTERISTICS OF INTERNATIONAL CARRIER TELEPHONE SYSTEMS ON RADIO-RELAY OR SATELLITE LINKS AND INTERCONNECTION WITH METALLIC LINES | G.400–G.449 |
+| COORDINATION OF RADIOTELEPHONY AND LINE TELEPHONY                                                                                            | G.450–G.499 |
+| <b>TESTING EQUIPMENTS</b>                                                                                                                    |             |
+| <b>TRANSMISSION MEDIA CHARACTERISTICS</b>                                                                                                    |             |
+| General                                                                                                                                      | G.600–G.609 |
+| Symmetric cable pairs                                                                                                                        | G.610–G.619 |
+| Land coaxial cable pairs                                                                                                                     | G.620–G.629 |
+| Submarine cables                                                                                                                             | G.630–G.649 |
+| Optical fibre cables                                                                                                                         | G.650–G.659 |
+| Characteristics of optical components and sub-systems                                                                                        | G.660–G.699 |
+| <b>DIGITAL TRANSMISSION SYSTEMS</b>                                                                                                          |             |
+| TERMINAL EQUIPMENTS                                                                                                                          | G.700–G.799 |
+| DIGITAL NETWORKS                                                                                                                             | G.800–G.899 |
+| DIGITAL SECTIONS AND DIGITAL LINE SYSTEM                                                                                                     | G.900–G.999 |
+
+*For further details, please refer to ITU-T List of Recommendations.*
+
+# **ITU-T RECOMMENDATION G.511**
+
+# **TEST METHODOLOGY FOR GROUP 3 FACSIMILE PROCESSING EQUIPMENT IN THE PUBLIC SWITCHED TELEPHONE NETWORK**
+
+## **Summary**
+
+This Recommendation defines the testing methodology for evaluating the performance of Group 3 facsimile processing equipment incorporated in Signal Processing Network Element (SPNE) of the Public Switched Telephone Network.
+
+###### **Source**
+
+ITU-T Recommendation G.511 was prepared by ITU-T Study Group 16 (1997-2000) and was approved under the WTSC Resolution No. 1 procedure on the 6th of February 1998.
+
+## FOREWORD
+
+ITU (International Telecommunication Union) is the United Nations Specialized Agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the ITU. The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis.
+
+The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics.
+
+The approval of Recommendations by the Members of the ITU-T is covered by the procedure laid down in WTSC Resolution No. 1.
+
+In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC.
+
+## NOTE
+
+In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+## INTELLECTUAL PROPERTY RIGHTS
+
+The ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. The ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process.
+
+As of the date of approval of this Recommendation, the ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementors are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database.
+
+© ITU 1998
+
+All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU.
+
+## CONTENTS
+
+|     |                                                                | <b>Page</b> |
+|-----|----------------------------------------------------------------|-------------|
+| 1   | Scope .....                                                    | 1           |
+| 2   | References .....                                               | 2           |
+| 3   | Abbreviations and definitions .....                            | 3           |
+| 3.1 | Abbreviations .....                                            | 3           |
+| 3.2 | Definitions .....                                              | 3           |
+| 4   | Overview .....                                                 | 4           |
+| 4.1 | Addressed issues.....                                          | 4           |
+| 4.2 | Direction of transmission .....                                | 5           |
+| 4.3 | Number of calls .....                                          | 6           |
+| 4.4 | Test pages.....                                                | 6           |
+| 4.5 | Facsimile terminal selection.....                              | 6           |
+| 5   | Facsimile terminal configurations.....                         | 6           |
+| 5.1 | Standard Group 3 facsimile mode.....                           | 7           |
+|     | 5.1.1 Std/Conf/1: Reference configuration .....                | 7           |
+|     | 5.1.2 Std/Conf/2 .....                                         | 7           |
+|     | 5.1.3 Std/Conf/3 .....                                         | 7           |
+|     | 5.1.4 Std/Conf/4 .....                                         | 7           |
+| 5.2 | Non-standard Group 3 facsimile mode .....                      | 8           |
+|     | 5.2.1 Non-standard Group 3 facsimile mode 1 .....              | 8           |
+|     | 5.2.2 Non-standard Group 3 facsimile mode 2 .....              | 8           |
+| 6   | Network conditions .....                                       | 8           |
+| 6.1 | Access-link impairments .....                                  | 8           |
+|     | 6.1.1 Definition .....                                         | 8           |
+|     | 6.1.2 Access link impairments conditions .....                 | 11          |
+| 6.2 | Traffic loading.....                                           | 11          |
+|     | 6.2.1 Definition .....                                         | 11          |
+|     | 6.2.2 Loading conditions.....                                  | 12          |
+| 6.3 | Delay.....                                                     | 12          |
+| 6.4 | Bearer impairments .....                                       | 12          |
+|     | 6.4.1 Circuit-oriented CME .....                               | 13          |
+|     | 6.4.2 Identification of the bearer channels with markers ..... | 14          |
+|     | 6.4.3 Packet-oriented CME.....                                 | 15          |
+|     | 6.4.4 Bearer conditions .....                                  | 15          |
+| 6.5 | Forward error correction.....                                  | 16          |
+
+|                                        | <b>Page</b>                                                                                             |
+|----------------------------------------|---------------------------------------------------------------------------------------------------------|
+| 6.6                                    | Return echo level..... 16                                                                               |
+| 6.7                                    | Reference conditions ..... 16                                                                           |
+| 6.7.1                                  | Reference test condition 1 ..... 16                                                                     |
+| 6.7.2                                  | Reference test condition 2..... 16                                                                      |
+| 6.7.3                                  | Reference test condition 3 ..... 17                                                                     |
+| 6.7.4                                  | Reference test condition 4..... 17                                                                      |
+| 6.7.5                                  | Reference test condition 5 ..... 17                                                                     |
+| 6.7.6                                  | Reference test condition 6..... 17                                                                      |
+| 6.7.7                                  | Reference test condition 7..... 18                                                                      |
+| 6.7.8                                  | Reference test condition 8..... 18                                                                      |
+| 7                                      | Facsimile call quality assessment..... 18                                                               |
+| 8                                      | Baseline measurements ..... 19                                                                          |
+| 8.1                                    | Facsimile terminal baseline tests..... 19                                                               |
+| 8.2                                    | CME baseline tests ..... 21                                                                             |
+| 9                                      | Test methodology ..... 21                                                                               |
+| Annex A – Group 3 facsimile procedures | ..... 24                                                                                                |
+| A.1                                    | Group 3 facsimile recognition: detection and classification ..... 24                                    |
+| A.1.1                                  | Objective ..... 24                                                                                      |
+| A.1.2                                  | Settings..... 24                                                                                        |
+| A.1.3                                  | Test conditions ..... 24                                                                                |
+| A.1.4                                  | Parameters of investigation..... 24                                                                     |
+| A.1.5                                  | Monitoring/measurement points ..... 24                                                                  |
+| A.2                                    | Proprietary facsimile fall-back to ADPCM path..... 24                                                   |
+| A.2.1                                  | Objective ..... 24                                                                                      |
+| A.2.2                                  | Settings..... 25                                                                                        |
+| A.2.3                                  | Test conditions ..... 25                                                                                |
+| A.2.4                                  | Parameters of investigation..... 25                                                                     |
+| A.2.5                                  | Monitoring/measurement points ..... 25                                                                  |
+| A.3                                    | Group 3 facsimile image quality in presence of combined access link and bearer link impairments..... 25 |
+| A.3.1                                  | Objective ..... 25                                                                                      |
+| A.3.2                                  | Settings..... 25                                                                                        |
+| A.3.3                                  | Test conditions ..... 26                                                                                |
+| A.3.4                                  | Monitoring/measurement points ..... 26                                                                  |
+| A.4                                    | Group 3 facsimile image quality in presence of bearer link impairments..... 26                          |
+| A.4.2                                  | Settings..... 26                                                                                        |
+| A.4.4                                  | Monitoring/measurement points ..... 26                                                                  |
+
+|                                                                                           | <b>Page</b> |
+|-------------------------------------------------------------------------------------------|-------------|
+| A.5 CME recovery following unexpected events during facsimile call progress.....          | 26          |
+| A.5.1 Objective .....                                                                     | 26          |
+| A.5.2 Settings.....                                                                       | 26          |
+| A.5.3 Test conditions .....                                                               | 27          |
+| A.6 Voiceband data quality.....                                                           | 28          |
+| A.6.1 Objective .....                                                                     | 28          |
+| A.6.2 Settings.....                                                                       | 28          |
+| A.6.3 Test conditions .....                                                               | 28          |
+| A.6.4 Monitoring/measurement points .....                                                 | 28          |
+| A.7 Effect of Group 3 facsimile protocol variability .....                                | 29          |
+| A.7.1 Objective .....                                                                     | 29          |
+| A.7.2 Settings.....                                                                       | 29          |
+| A.7.3 Test conditions .....                                                               | 29          |
+| A.7.4 Parameters of investigation.....                                                    | 29          |
+| A.8 Effect of transmission level and echo return loss.....                                | 30          |
+| A.8.1 Objective .....                                                                     | 30          |
+| A.8.2 Settings.....                                                                       | 30          |
+| A.8.3 Test conditions .....                                                               | 30          |
+| A.8.4 Parameters of investigation.....                                                    | 30          |
+| A.8.5 Monitoring/measurement points .....                                                 | 30          |
+| A.9 Impact of transmission integrity due to timing deviations on facsimile call quality.. | 31          |
+| A.9.1 Objective .....                                                                     | 31          |
+| A.9.2 Settings.....                                                                       | 31          |
+| A.9.3 Test conditions .....                                                               | 31          |
+| A.9.4 Monitoring/measurement points .....                                                 | 31          |
+| A.10 Items for further study.....                                                         | 31          |
+| A.10.1 Rates and modulation schemes .....                                                 | 31          |
+| A.10.2 Facsimile quality assessment .....                                                 | 31          |
+| A.10.3 Coding algorithms.....                                                             | 31          |
+| A.10.4 Errors.....                                                                        | 32          |
+| A.10.5 CME networks .....                                                                 | 32          |
+| A.10.6 Other SPNE.....                                                                    | 32          |
+| Appendix I – Identifying a demodulated call in a DCME.....                                | 32          |
+| I.1 Principles.....                                                                       | 32          |
+| I.2 Implementation.....                                                                   | 33          |
+
+
+
+# Recommendation G.511
+
+# TEST METHODOLOGY FOR GROUP 3 FACSIMILE PROCESSING EQUIPMENT IN THE PUBLIC SWITCHED TELEPHONE NETWORK
+
+(Geneva, 1998)
+
+# 1 Scope
+
+This Recommendation defines the testing methodology for evaluating the performance of Group 3 facsimile processing equipment incorporated in Signal Processing Network Element (SPNE) of the Public Switched Telephone Network.
+
+The testing methodology covers the following aspects:
+
+- 1) facsimile recognition (i.e. detection and classification);
+- 2) proprietary facsimile fall-back to ADPCM path;
+- 3) Group 3 facsimile image quality in presence of:
+  - a) combined access link impairments and bearer link impairments;
+  - b) bearer link impairments;
+- 4) recovery following unexpected events during the facsimile call set-up;
+- 5) voiceband data quality;
+- 6) effect of variability in the implementation of the T.30 protocol;
+- 7) effects of transmission level variation and echo return loss;
+- 8) impact of transmission integrity due to timing deviations on facsimile call quality.
+
+The basic configuration employed in these tests is shown in Figure 1.
+
+![Diagram of the basic configuration for testing facsimile processing equipment in a Signal Processing Network Element (SPNE).](a234352dfaccdc24745c88eef7724cc6_img.jpg)
+
+The diagram illustrates the basic configuration for testing facsimile processing equipment. It shows a flow from left to right, indicated by a long arrow at the bottom labeled 'Direction of document transmission'. The flow starts with a 'FAX Calling end' box on the left. An arrow points from this box to a large box labeled 'Calling SPNE'. Above this arrow is the label 'Access-link impairments'. From the 'Calling SPNE' box, an arrow points to another large box labeled 'Called SPNE'. Above this arrow is the label 'Bearer-link impairments'. From the 'Called SPNE' box, an arrow points to a 'FAX Called end' box on the right. Above this arrow is the label 'Access-link impairments'. Below the 'Calling SPNE' box, an arrow labeled 'Other traffic' points into the box. Similarly, below the 'Called SPNE' box, an arrow labeled 'Other traffic' points into the box. At the bottom right of the diagram, the text 'T1600540-97' is present.
+
+Diagram of the basic configuration for testing facsimile processing equipment in a Signal Processing Network Element (SPNE).
+
+**Figure 1/G.511 – Basic configuration for testing facsimile processing equipment  
+in Signal Processing Network Element (SPNE)**
+
+In Figure 1, SPNE represents a signal processing network element. In general, this SPNE can process other signals than facsimile signals. However, only the Group 3 facsimile processing aspects of Circuit Multiplication Equipment (CME) and Echo Cancellers (EC) is discussed in this Recommendation. Other types of SPNE are for further study.
+
+## 2 References
+
+The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; all users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published.
+
+- ITU-T Recommendation E.451 (1993), *Facsimile call cut-off performance*.
+- ITU-T Recommendation E.452 (1993), *Facsimile modem speed reductions and transaction time*.
+- ITU-T Recommendation E.453 (1994), *Facsimile image quality as corrupted by transmission-induced scan line errors*.
+- ITU-T Recommendation E.456 (1994), *Test transaction for facsimile transmission performance*.
+- ITU-T Recommendation G.701 (1993), *Vocabulary of digital transmission and multiplexing, and Pulse Code Modulation (PCM) terms*.
+- CCITT Recommendation G.711 (1998), *Pulse Code Modulation (CPM) of Voice-Frequencies*.
+- ITU-T Recommendation G.165 (1993), *Echo cancellers*.
+- ITU-T Recommendation G.720 (1995), *Characterization of low-rate digital voice coder performance with non-voice signals*.
+- CCITT Recommendation G.726 (1990), *40, 32, 24, 16 kbit/s Adaptive Differential Pulse Code Modulation (ADPCM)*.
+- CCITT Recommendation G.727 (1990), *5-, 4-, 3- and 2-bits/sample embedded Adaptive Differential Pulse Code Modulation (ADPCM)*.
+- CCITT Recommendation G.728 (1992), *Coding of speech at 16 kbit/s using low-delay code excited linear prediction*.
+- ITU-T Recommendation G.729 (1996), *Coding of speech at 8 kbit/s using conjugate structure Algebraic-Code-Excited Linear Prediction (CS-ACELP)*.
+- CCITT Recommendation G.763 (1991), *Digital circuit multiplication equipment using ADPCM Recommendation G.726 and digital speech interpolation*.
+- CCITT Recommendation G.764 (1990), *Voice packetization – Packetized voice protocols*.
+- CCITT Recommendation G.765 (1992), *Packet circuit multiplication equipment*.
+- CCITT Recommendation G.766 (1992), *Facsimile demodulation/remodulation for DCME*.
+- ITU-T Recommendation G.826 (1993), *Error performance parameters and objectives for international, constant bit rate digital paths at or above the primary rate*.
+- ITU-T Recommendation T.4 (1996), *Standardization of Group 3 facsimile apparatus for document transmission*.
+
+- ITU-T Recommendation T.22 (1993), *Standardized test charts for document facsimile transmission.*
+- ITU-T Recommendation T.30 (1996), *Procedures for document facsimile transmission in the general switched telephone network.*
+- CCITT Recommendation V.17 (1991), *2-Wire modem for facsimile applications with rates up to 14 400 bit/s.*
+- CCITT Recommendation V.21 (1984), *300 bits per second duplex modem standardized for use in the general switched telephone network.*
+- CCITT Recommendation V.27 *ter* (1984), *4800/2400 bits per second modem standardized for use in the general switched telephone network.*
+- CCITT Recommendation V.29 (1988), *9600 bits per second modem standardized for use on point-to-point 4-wire leased telephone-type circuits.*
+- CCITT Recommendation V.33 (1988), *14 400 bits per second modem standardized for use on point-to-point 4-wire leased telephone-type circuits.*
+- ITU-T Recommendation V.34 (1996), *A modem operating at data signalling rates of up to 33 600 bit/s for use on the general switched telephone network and on leased point-to-point 2-wire telephone type circuits.*
+
+# 3 Abbreviations and definitions
+
+## 3.1 Abbreviations
+
+This Recommendation uses the following abbreviations:
+
+|      |                                                                   |
+|------|-------------------------------------------------------------------|
+| CME  | Circuit Multiplexing Equipment                                    |
+| DCME | Digital Circuit Multiplexing Equipment (see Recommendation G.763) |
+| EC   | Echo Canceller (see Recommendation G.165)                         |
+| HOL  | Heavy overload condition with speech traffic in a CME             |
+| OL   | Overload condition with speech traffic in a CME                   |
+| OLF  | Overload condition due to facsimile in a CME                      |
+| PCME | Packet Circuit Multiplexing Equipment (see Recommendation G.765)  |
+| SPNE | Signal Processing Network Element. Examples: DCME, PCME, EC       |
+| UL   | Underload condition with speech traffic in a CME                  |
+
+## 3.2 Definitions
+
+This Recommendation defines the following terms:
+
+**3.2.1 ADPCM path:** This is the transmission path within the CME when the facsimile signal is going through the ADPCM encoder/decoder.
+
+**3.2.2 control channel:** In a circuit-oriented circuit multiplication equipment, the control channel is a unidirectional transmission path from the transmit unit of one CME to the receive unit of one or more associated CMEs. This control channel is dedicated primarily to carrying channel assignment messages. In addition, the control channel transmits other messages such as idle noise level, dynamic load control, alarm messages and optionally, line signalling information.
+
+For a packet-oriented circuit multiplication equipment, the CME control channel is either the packet header of a packet carrying the user's traffic or a special packet carrying control information.
+
+**3.2.3 demodulated transmission path:** This is the path of the facsimile signal when the baseband signal has been extracted by demodulation.
+
+**3.2.4 facsimile demodulation/remodulation:** This is the processing function in a CME where facsimile is discriminated from voiceband data and subsequently demodulated to recover the baseband digital signal. It is then remodulated at the terminating CME.
+
+**3.2.5 forward bearer channel:** This is the bearer channel from the calling to the called CME. The direction of facsimile document transmission is assumed to be from the calling to the called CME (see Figure 2).
+
+**3.2.6 grouped errors:** These are the digital impairments that either affect each bit of a contiguous stream of CME bearer channel bits, or a group of contiguous bits (but not necessarily all bits) according to a pattern determined *a priori*.
+
+**3.2.7 non-demodulated transmission path:** This is the path of the facsimile signal when the baseband signal is not demodulated, but is either PCM or ADPCM coded.
+
+**3.2.8 non-standard/mode 1:** This is the mode of transmission where the facsimile terminals at both ends transmit in proprietary mode, although the CME is capable of demodulating and remodulating the high-speed image/message transmissions.
+
+**3.2.9 non-standard/mode 2:** This is the mode of transmission where the facsimile terminals at both ends transmit in proprietary mode, although the CME is **not capable** of demodulating and remodulating the high speed image/message transmissions.
+
+**3.2.10 return bearer channel:** This is the bearer channel from the called to the calling CME (see Figure 2).
+
+# 4 Overview
+
+### 4.1 Addressed issues
+
+The test methodology presented in this Recommendation makes provisions for the insertion of impairments on the access links and the bearer links for a variety of test conditions, and also the evaluation of the quality of facsimile image, after processing by the terminating SPNE.
+
+In particular, the following issues will be addressed:
+
+- 1) Recognition of Group 3 facsimile calls by the calling CME, and routing to an appropriate facsimile ADPCM or demodulation/remodulation module, if any;
+- 2) In case of facsimile demodulation/remodulation equipment, fall-back from a demodulated signal path to an ADPCM signal path, during the set-up process of a facsimile call;
+- 3) Assessment of the Group 3 facsimile received image quality when transmitted in CME over the non-demodulated signal path in the presence of access link impairments in the forward calling access link and the forward called access link. Figure 2 shows the location of the forward calling and called access link impairments when testing CME;
+
+![Diagram illustrating the designation of end-to-end communication links for a facsimile system. The diagram shows a 'Calling end' (FAX) on the left and a 'Called end' (FAX) on the right. Between them are two large rectangular blocks representing CME systems. The left block contains 'Calling CME fax demodulation' (top) and 'Calling CME fax remodulation' (bottom). The right block contains 'Called CME fax remodulation' (top) and 'Called CME fax demodulation' (bottom). Four links connect the ends: 'Forward calling access link' (top left to top of left block), 'Return calling access link' (bottom of left block to bottom left), 'Forward bearer channel' (top of left block to top of right block), and 'Return bearer channel' (bottom of right block to bottom of left block). Additionally, 'Forward called access link' connects the top of right block to the top right 'FAX', and 'Return called access link' connects the bottom right 'FAX' to the bottom of right block. A horizontal arrow at the bottom indicates the 'Direction of document transmission' from left to right.](af7916c89a458fdab6c3f443217388ae_img.jpg)
+
+T1600550-97
+
+Diagram illustrating the designation of end-to-end communication links for a facsimile system. The diagram shows a 'Calling end' (FAX) on the left and a 'Called end' (FAX) on the right. Between them are two large rectangular blocks representing CME systems. The left block contains 'Calling CME fax demodulation' (top) and 'Calling CME fax remodulation' (bottom). The right block contains 'Called CME fax remodulation' (top) and 'Called CME fax demodulation' (bottom). Four links connect the ends: 'Forward calling access link' (top left to top of left block), 'Return calling access link' (bottom of left block to bottom left), 'Forward bearer channel' (top of left block to top of right block), and 'Return bearer channel' (bottom of right block to bottom of left block). Additionally, 'Forward called access link' connects the top of right block to the top right 'FAX', and 'Return called access link' connects the bottom right 'FAX' to the bottom of right block. A horizontal arrow at the bottom indicates the 'Direction of document transmission' from left to right.
+
+**Figure 2/G.511 – Designation of end-to-end communication links**
+
+- 4) Assessment of the Group 3 facsimile received image quality when transmitted in the CME over the demodulated signal path, with and without Forward Error Correction (FEC) and with:
+  - random errors in forward and/or return bearer channels;
+  - grouped errors in forward and/or return bearer channels;
+  - burst errors in forward and/or return bearer channels.
+- 5) Impact of "heavy" loading on Group 3 facsimile;
+- 6) CME recovery following premature call disconnections and/or abnormal behaviour at the facsimile end-customer premises;
+- 7) Processing of voiceband data, using the same modulation schemes as used in the facsimile signal facsimile, by CME systems that support both ADPCM coding and facsimile demodulation/remodulation capabilities;
+- 8) Impact of Group 3 facsimile protocol variability on CME system behaviour and facsimile call quality;
+- 9) Impact of transmission level variation and echo return loss on CME system behaviour and facsimile call quality;
+- 10) Impact of transmission integrity due to timing deviations on facsimile call quality;
+- 11) Verification of retransmission level at remodulated output.
+
+## **4.2 Direction of transmission**
+
+In each test condition the direction of document transmission shall be the same as the direction under test (standard mode of communication). Optionally, the direction of document transmission may be the opposite of the direction under test (polling mode of communication). Tests shall be conducted by transmitting three consecutive pages of documentation. It is preferable that the calling facsimile terminal be fully electronic (or with electronic memory) so that the document scanning process is only undertaken once, and thus does not become a variable in this investigation.
+
+## 4.3 Number of calls
+
+For each test condition, at least 20 calls shall be initiated (60 attempted page transmissions in total) so that the error count of measured performance parameters is not less than 100.
+
+In Table 1 the percentage error intervals (at a 95% confidence level) for four different rates of transmission failures are shown as a function of the total number of pages transmitted. For example, when 60 transmitted pages result in 30 of them being unacceptable (i.e. failure rate of 50%) the mean percentage of pages in error is  $50\% \pm 13\%$ . In this case, the magnitude of the error is approximately 1/3 of the size of the mean. As the failure rate increases to 70%, the error magnitude stays approximately the same (12%, therefore resulting in a mean percentage of pages in error of  $70\% \pm 12\%$ ) but, as a proportion to the mean, the error size decreases to approximately 1/5.
+
+## 4.4 Test pages
+
+Test charts Nos. 4 and 5 of Recommendation T.22 shall be used.
+
+NOTE – Test chart No. 4 is the same as test chart No. 2 in Recommendation T.21, which is mentioned in Recommendation E.456.
+
+To evaluate the performance of facsimile transmissions as a function of transmitted page length, pages with different image content may also be used, so that the time it takes to transmit one page of documentation varies between 20 seconds and 200 seconds (at a user signalling rate of 9.6 kbit/s). The density of information content for such pages, expressed as the average number of bits (after one-dimensional run length encoding) per scan-line is defined to be equal to 250 bit/scan-line.
+
+**Table 1/G.511 – Percentage error intervals at 95% confidence level**
+
+| <b>Pages per call</b> | <b>Total number of calls</b> | <b>Total number of pages</b> | <b>Mean failure rate 5%</b> | <b>Mean failure rate 20%</b> | <b>Mean failure rate 50%</b> | <b>Mean failure rate 70%</b> |
+|-----------------------|------------------------------|------------------------------|-----------------------------|------------------------------|------------------------------|------------------------------|
+| 3                     | 10                           | 30                           | $\pm 4\%$                   | $\pm 15\%$                   | $\pm 18\%$                   | $\pm 16\%$                   |
+| 3                     | 20                           | 60                           | $\pm 3\%$                   | $\pm 10\%$                   | $\pm 13\%$                   | $\pm 12\%$                   |
+| 3                     | 30                           | 90                           | $\pm 2\%$                   | $\pm 8\%$                    | $\pm 11\%$                   | $\pm 9\%$                    |
+| 3                     | 40                           | 120                          | $\pm 2\%$                   | $\pm 4\%$                    | $\pm 5\%$                    | $\pm 4\%$                    |
+
+## 4.5 Facsimile terminal selection
+
+Terminals shall be selected so that the test operator can control whether they operate in a standard or proprietary mode.
+
+# 5 Facsimile terminal configurations
+
+Three basic types of end-customer facsimile terminal set-ups are used in these tests:
+
+- terminals operating in the standard Group 3 facsimile mode;
+- terminals capable of communicating in a non-standard/mode 1 configuration;
+- terminals capable of communicating in a non-standard/mode 2 configuration.
+
+### **5.1 Standard Group 3 facsimile mode**
+
+This subclause addresses equipment set-up to control the variability that may exist among terminals conforming to Recommendations T.4 and T.30. Four standard facsimile call configurations are defined. All configurations shall be tested.
+
+The first configuration, denoted as Std/Conf/1, is the reference configuration.
+
+#### **5.1.1 Std/Conf/1: Reference configuration**
+
+The purpose of this test configuration is to test the operation with the V.29 modulation scheme at 9600 bit/s. The objective is to minimize the variability of protocol paths that can be followed by the facsimile terminals, so that image data obtained at different times, and over different CME, can be more conveniently compared against each other.
+
+The test steps are as follows:
+
+- i) The facsimile terminals shall be set-up in such a way, so that only the 9600 bit/s of the V.29 modulation scheme is employed.
+- ii) The terminals shall be set up in the standard resolution mode.
+- iii) The terminals shall be set up to employ the one-dimensional coding scheme (Run Length Coding – RLC).
+- iv) Terminals shall be used with non-standard facility options disabled. If this is not possible, terminals from different manufacturers shall be used at opposite ends of the circuit connection.
+- v) The transmitting and receiving units shall be configured in the auto-calling and auto-answering modes respectively.
+- vi) The error-correction mode shall be disabled. If it is not possible to disable this function, at least one of the terminals selected must not support this capability.
+
+#### **5.1.2 Std/Conf/2**
+
+The purpose of this test configuration is to test the operation at rates lower than 9600 bit/s modulation. The objective is to minimize the variability of protocol paths that can be followed by the facsimile terminals, so that image data obtained at different times, and over different CME, can be more conveniently compared against each other.
+
+In this configuration, the facsimile terminals may employ any of the following user data signalling rates for facsimile image communication:
+
+- V.29 at 7200 bit/s;
+- V.27 *ter* at 4800 bit/s;
+- V.27 *ter* at 2400 bit/s.
+
+Other rates and modulation schemes are for further study.
+
+#### **5.1.3 Std/Conf/3**
+
+In this configuration, limitations imposed upon Std/Conf/1 and Std/Conf/2, such as resolution, error-correction, two-dimensional coding, and polling are removed.
+
+#### **5.1.4 Std/Conf/4**
+
+The purpose of this test configuration is to test the capability of the CME for rate negotiation during fall-back.
+
+### **5.2 Non-standard Group 3 facsimile mode**
+
+#### **5.2.1 Non-standard Group 3 facsimile mode 1**
+
+Terminals shall be selected so that proprietary communication can be successfully established through "Phase B" of the Group 3 facsimile protocols. In this case, the transmission over the CME bearer takes place over a demodulated signal path.
+
+#### **5.2.2 Non-standard Group 3 facsimile mode 2**
+
+Terminals shall be selected so that proprietary communication can only be successfully established through "Phase B" of the Group 3 facsimile protocols if this takes place over an ADPCM path. Initial establishment over a demodulated path during "Phase A" of the Group 3 facsimile protocols with subsequent reassignment to an ADPCM encoded path during "Phase B" is permitted under this mode.
+
+# **6 Network conditions**
+
+This clause presents the various parameters used in the tests.
+
+### **6.1 Access-link impairments**
+
+#### **6.1.1 Definition**
+
+Impairments are injected in the facsimile signal in the voiceband domain primarily in the direction of transmission of image information. Figure 3 shows where access-link impairments are injected in the forward access link between the calling facsimile terminal and the calling CME demodulator. Similarly, Figure 4 shows the injection of access-link impairments between the called CME remodulator and the called facsimile terminal. In both figures, the notations PCM and PCM<sup>-1</sup> indicate a G.711 PCM encoder and a G.711 PCM decoder, respectively.
+
+![Block diagram of the forward access link between a calling facsimile terminal and a calling CME demodulator, showing the injection of access-link impairments.](8fbdfc3d17fb1dae7b2d8f5a287fa9fc_img.jpg)
+
+The diagram illustrates the signal path and impairment injection points in a facsimile system. At the top, a horizontal arrow indicates the 'Direction of document transmission' from left to right. At the bottom, a horizontal line separates the 'Analogue voiceband' (left) from the 'Digital voiceband' (right), with a vertical dashed line as a boundary.
+
+The signal flow is as follows:
+
+- Calling end (FAX):** The signal originates from the 'FAX' block on the left.
+- 2- to 4-wire conversion:** The signal passes through a conversion block.
+- Analogue impairments:** The signal enters the 'Analogue impairments' block.
+- PCM (1):** The signal is encoded by a PCM block, labeled with a '1' and an arrow.
+- PCM<sup>-1</sup> (2):** The signal is decoded by a PCM<sup>-1</sup> block, labeled with a '2' and an arrow.
+- Echo control:** The signal passes through an 'Echo control' block.
+- Digital impairments:** 'Digital impairments' are injected into the signal path after the echo control block.
+- S<sub>out</sub> and R<sub>in</sub>:** The signal is split into two paths:  $S_{out}$  (output) and  $R_{in}$  (input).
+- Calling CME demodulation and remodulation:** The signal is processed by 'Calling CME demodulation' and 'Calling CME remodulation' blocks.
+- PCM<sup>-1</sup> (3):** The signal is decoded by a PCM<sup>-1</sup> block, labeled with a '3' and an arrow.
+
+Labels 1, 2, and 3 point to the PCM, PCM<sup>-1</sup>, and PCM<sup>-1</sup> blocks respectively.
+
+T1600560-97
+
+Block diagram of the forward access link between a calling facsimile terminal and a calling CME demodulator, showing the injection of access-link impairments.
+
+NOTE – PCM represents a G.711 encoder and PCM<sup>-1</sup> represents a G.711 decoder.
+
+**Figure 3/G.511 – Injection of access-link impairments in the forward access links between the calling facsimile terminal and the calling CME demodulator**
+
+![Block diagram showing the injection of access-link impairments in the return access links between a called CME demodulator and a called facsimile terminal. The diagram includes blocks for Called CME fax remodulation and demodulation, Echo control, PCM encoder (5), PCM-1 decoder (4), Digital impairments, Analogue impairments, 2- to 4-wire conversion, and a FAX terminal. A dashed line separates Digital voiceband from Analogue voiceband.](76b0cd79baaedd942af4dc42f2e764b8_img.jpg)
+
+```
+
+graph LR
+    subgraph CME_System [Called CME]
+        direction TB
+        Remod[Called CME fax remodulation]
+        Demod[Called CME fax demodulation]
+    end
+
+    Echo[Echo control]
+    Sum(( ))
+    PCM1[PCM-1 4]
+    PCM[PCM 5]
+    DigImp[Digital impairments]
+    AnaImp[Analogue impairments]
+    Conv[2- to 4-wire conversion]
+    Fax[FAX Called end]
+
+    Remod -- Rin --> Echo
+    Echo -- Sout --> Demod
+    Echo --> PCM1
+    PCM1 --> Conv
+    Echo --> Sum
+    DigImp --> Sum
+    Sum --> PCM
+    PCM --> AnaImp
+    AnaImp --> Conv
+    Conv <--> Fax
+
+    style CME_System fill:none,stroke:#000
+
+```
+
+The diagram illustrates the signal path for document transmission. On the left, a box contains 'Called CME fax remodulation' and 'Called CME fax demodulation'. The remodulation section outputs  $R_{in}$  to an 'Echo control' block. The demodulation section receives  $S_{out}$  from the 'Echo control' block. The 'Echo control' block connects to a summing junction where 'Digital impairments' are added. This leads to a 'PCM' block (labeled 5). Parallel to this, the 'Echo control' also connects to a 'PCM<sup>-1</sup>' block (labeled 4). Both PCM blocks connect to a '2- to 4-wire conversion' unit. The path from PCM 5 passes through 'Analogue impairments' before reaching the conversion unit. The conversion unit connects to the 'FAX' terminal at the 'Called end'. A vertical dashed line divides the 'Digital voiceband' (left) from the 'Analogue voiceband' (right). An arrow at the top indicates the 'Direction of document transmission'.
+
+Block diagram showing the injection of access-link impairments in the return access links between a called CME demodulator and a called facsimile terminal. The diagram includes blocks for Called CME fax remodulation and demodulation, Echo control, PCM encoder (5), PCM-1 decoder (4), Digital impairments, Analogue impairments, 2- to 4-wire conversion, and a FAX terminal. A dashed line separates Digital voiceband from Analogue voiceband.
+
+T1600570-97
+
+NOTE – PCM represents a G.711 encoder and PCM<sup>-1</sup> represents a G.711 decoder.
+
+**Figure 4/G.511 – Injection of access-link impairments in the return access links between the called CME demodulator and the called facsimile terminal**
+
+The calling access-link impairments depicted in Figure 3 comprise voiceband analogue impairments (see 6.1.1.1) and voiceband digital impairments (see 6.1.1.2). The level of network performance degradation that the digital impairments introduce will depend on the location where these impairments are injected. PCM encoder No. 1 and PCM decoder No. 3 are used for interfacing the input and output CME channels to the analogue part of the network. PCM decoder No. 2 is used for calibration procedures only, and is not required when tests are actually undertaken.
+
+Similarly, the called access-link impairments shown in Figure 4 comprise voiceband analogue impairments and voiceband digital impairments. PCM decoder No. 4 and PCM encoder No. 5 are used for interfacing the input and output CME channels to the analogue part of the network.
+
+The (single channel) input to the CME system is assumed to be encoded according to the Recommendation G.711 64 kbit/s PCM (A-law, or  $\mu$ -law, as necessary for CME compatibility) format. An echo canceller, which is necessary for the correct functioning of CME, is inserted on the line side of the PCM conversion. Note that if echo control is not available, then the termination shall be balanced so that the echo return loss exceeds 40 dB.
+
+Note that when end-to-end performance is evaluated, a local office network/simulating loop is used between the facsimile terminals and the 2- to 4-wire conversion to provide ringing, voltage drop, DTMF decoding and other locally generated signals. This end-loop is not shown in the figure to avoid unnecessary details.
+
+##### 6.1.1.1 Analogue impairments
+
+The analogue channel shall permit the introduction of two types of network impairments: variable and fixed. Variable impairments consist of the linear addition of controlled amounts of band-limited analogue white noise prior to the digitally encoded channel. Fixed impairments consist of group and attenuation distortion, phase jitter, and second and third order non-linear distortion. The impairments to be injected in the analogue channel should be in accordance with Tables 1/G.720 and 2/G.720.
+
+The test configuration is the same as shown in Figures 1/G.720 and 2/G.720.
+
+##### 6.1.1.2 Digital impairments
+
+For further study.
+
+#### 6.1.2 Access link impairments conditions
+
+- 1) Analogue voiceband impairments will be as specified in Tables 1/G.720 and 2/G.720.
+- 2) Selected PCM-path digital errors are introduced between the calling CME and calling facsimile terminal (i.e. between the calling CME decoder and PCM decoder No. 2). This is used to investigate the CME recovery procedures during unexpected signal-type transmissions resulting from procedural signal corruption.
+
+### 6.2 Traffic loading
+
+#### 6.2.1 Definition
+
+Four conditions for loading the CME are defined for the purposes of investigating facsimile quality and CME behaviour. These are:
+
+- CME in an Underload (UL) condition with speech traffic;
+- CME in an Overload (OL) condition with speech traffic;
+- CME in a Heavy Overload (HOL) condition with speech traffic;
+- CME in an Overload condition due to Facsimile (OLF).
+
+To simulate the four loading conditions defined above, a channel activity simulator shall be employed. For all CME input channels which carry traffic, other than facsimile, the simulated voice activity factor shall be equal to 37%. This activity factor shall be used for both calling and called CME, although the loading conditions will, typically, be separately defined (see 6.2.2) at each end, thus implying that traffic asymmetry may be desirable for some test conditions.
+
+##### 6.2.1.1 CME in a UL condition
+
+In this case, the number of CME input trunks carrying speech are less than or equal (including any facsimile traffic under test) to the number of CME bearer channels available for carrying speech. No CME bearer channels are thus in overload in this configuration and, for simulated speech traffic, the average bits per sample equals 4.0. Any facsimile traffic is applied on a single CME input channel only.
+
+##### 6.2.1.2 CME in an OL condition
+
+In this case, the number of CME input trunks carrying speech exceeds (including any facsimile traffic under test) the number of CME bearer channels available for carrying speech. Therefore, a significant number of channels (**but not all**) may be in overload thus causing, for simulated speech traffic, the average bits per sample to equal 3.7 to 3.8. Any facsimile traffic is applied on a single CME input channel only.
+
+##### 6.2.1.3 CME in an HOL condition
+
+In this case, the average bit per sample equals 3.3 to 3.4 (for simulated speech traffic). Any facsimile traffic is applied on a single CME input channel only.
+
+##### 6.2.1.4 CME in an OLF condition
+
+In this case, 70% of the CME bearer channel capacity is occupied due to the transport of facsimile traffic and the remaining capacity is used to carry simulated speech traffic at a lower average but per sample than what achieves toll quality. (This is defined for each coding algorithm and for each type of equipment.) The facsimile traffic is real, rather than simulated, using repeated 3-page transmissions in the standard configurations defined in 5.4 are employed. These transmissions are used for the purpose of loading the CME in a controlled fashion; however, their quality is not monitored. In this case, a new facsimile call is initiated every 10 s.
+
+NOTE – Testing of CME with other voice coding algorithms than ADPCM, e.g. G.728 and G.729, is for further study.
+
+#### 6.2.2 Loading conditions
+
+Seven different configurations are described. The first four to be used in every case, and the last three to be used in multiple or multinode only.
+
+| Loading Condition | Calling CME | Called CME | Remarks                             |
+|-------------------|-------------|------------|-------------------------------------|
+| 1                 | UL          | UL         | All cases                           |
+| 2                 | OL          | OL         | All cases                           |
+| 3                 | HOL         | HOL        | All cases                           |
+| 4                 | OLF         | OLF        | All cases                           |
+| 5                 | OL          | UL         | Multidestination and multinode only |
+| 6                 | HOL         | UL         | Multidestination and multinode only |
+| 7                 | OLF         | UL         | Multidestination and multinode only |
+
+### 6.3 Delay
+
+To simulate different types of possible connections, delay should be introduced in the CME bearer link, when undertaking laboratory tests.
+
+Three conditions will be tested:
+
+- LD: Low Delay to represent fibre or submarine cable connections – **40 ms one-way delay**.
+- MD: Medium Delay to represent one-hop satellite connections – **270 ms one-way delay**.
+- HD: High Delay to represent two-hop satellite connections – **540 ms one-way delay**.
+
+### 6.4 Bearer impairments
+
+The digital errors introduced here shall be as representative as possible of the actual conditions on the transmission link.
+
+The purpose of introducing bearer impairments is to:
+
+- 1) observe the effect of bearer channel impairments on the end-user facsimile terminal customer performance;
+- 2) observe the CME behaviour when particular types of traffic are being transmitted under specific bearer channel impairment conditions;
+
+- 3) mark customer traffic so that the CME path employed can be determined at the destination end-user terminal location.
+
+Injection of errors on the bearer depends on whether the CME is based on circuit or packet transmission. In case of circuit-based transmission, two different methods to generate and inject impairments in the CME bearer channel are possible.
+
+#### **6.4.1 Circuit-oriented CME**
+
+There are two aspects to be considered in circuit-oriented CME, the generation of the bearer channels with injection of markers.
+
+##### **6.4.1.1 Generation of bearer errors**
+
+The purpose of this method is:
+
+- 1) to assess the performance obtained at the end-user facsimile terminal under simulated operating conditions;
+- 2) to observe the CME's behaviour under specific impairment conditions (that may include and/or exceed the extreme values of the CME operating range).
+
+The reference condition will be a time interval during which there are no bit errors (i.e. error-free interval).
+
+Digital errors in the bearer channel shall be injected according to one of the following formats:
+
+- 1) Random bit errors over the entire bearer representing the operating range of interest;
+- 2) Grouped errors according to the following patterns:
+  - Specific bit errors over the customer traffic-carrying bearer slots only (i.e. CME control channel excluded, assuming there is one);
+  - Specific bit errors over the CME control channel slots only (assuming there is one);
+  - Specific burst errors over the entire CME bearer channel;
+  - Specific multiple errors over the entire CME bearer channel.
+- 3) Random burst errors of controlled duration over the entire CME bearer channel.
+
+In particular, for the grouped and burst errors:
+
+- 1) The specific errors patterns to be introduced in circuit-oriented CME customer traffic-carrying slots are generated as follows:
+  - For ADPCM encoded channels:
+    - Least Significant Bit (LSB);
+    - Second LSB;
+    - Third LSB (or Most Significant Bit – 1);
+    - Fourth LSB (= Most Significant Bit) (if there is one).
+
+Other types of traffic are for further study.
+
+- 2) The specific error patterns to be introduced in circuit-oriented CME control channels are defined as follows:
+  - LSB;
+  - LSB and second LSB;
+  - LSB, second LSB and third LSB;
+  - LSB, second LSB and third LSB.
+
+- 3) For the introduction of specific burst-error patterns over the entire CME bearer, a "burst-error injector" is required. This equipment permits the selective (by position) inversion of a specified number of bits, starting after the expiration of a predetermined time interval where no bit errors are injected. Three parameters are defined:
+  - length of burst;
+  - bit-error distribution within burst;
+  - frequency of burst occurrence.
+- 4) Specific multiple-error patterns over the entire bearer channel are generated by corruption of contiguous CME bearer bits. This is accomplished by employing an impulse generator to inject single errors at a preselectable rate. A custom-built unit which permits the corruption of the next one, two, three, four, or five contiguous bits for every bit error inserted in the digitally transmitted signal is used for this test configuration. This will give rise to contiguous single, double, triple, quadruple, quintuple, and sextuple error events respectively.
+- 5) Random burst errors of controlled duration over the entire bearer may be generated by utilization of a burst-error generator to directly inject errors into the CME bearer channel. This method permits the corruption of N randomly distributed bits within a contiguous window of 2N bits of transmitted data. This method of burst-error generation (which are no longer specific) utilizes commercially available bit-error equipment.
+
+#### **6.4.2 Identification of the bearer channels with markers**
+
+The purpose here is to mark the end-user traffic to tag the CME path employed at the destination end-user terminal location. The idea is to exploit the difference in transmission error properties of the ADPCM encoded path and the facsimile demodulated/remodulated path.
+
+In particular, it is known that errors are injected in the ADPCM encoded path, the recovered baseband signal at the receiving facsimile terminal will experience more bits with errors for every erroneous bit of the encoded bit-stream. This effect is known as the error multiplication effect. By contrast, errors introduced on a demodulated CME path (in the now baseband signal), the recovered baseband signal at the receiving facsimile terminal will only contain the same number of bits in error as the number of erroneous bits in the CME bearer bit-stream. It is assumed, of course, that no further impairments are introduced in the facsimile signal between the CME remodulation point and the receiving end-user terminal.
+
+This property can be used to tag the traffic so that the correct routing of facsimile messages can be determined at the called facsimile terminal without decoding the CME input to bearer channel assignment information.
+
+These type of "marking" errors are introduced as follows:
+
+The entire bearer stream of one (and only one) CME frame is impaired so that every bit (preferably excluding any CME control channels) is in error. The type of frame to be in error is for further study and may be CME terminal dependent. Since each bearer slot that can carry voiceband data is either 4, 5 or 8 bits, inverting the user traffic will result in:
+
+- 1) no more than 8 bits in error, if the facsimile traffic is carried in the demodulated path; or
+- 2) several bits in error (typically > 15) if the facsimile traffic is carried in the ADPCM path.
+
+This observation is obtained at the receiving (called) facsimile terminal, and is based on the assumption that the baseband Run-Length Coded bit-stream transmitted by the calling terminal is known at the called terminal. It is preferable to avoid traffic "error marking" and rely on CME internal reporting capabilities, if possible.
+
+#### 6.4.3 Packet-oriented CME
+
+In packet-oriented CME, the concepts of a bearer channel separate from a control channel do not apply. Therefore, the concern will be only the generation of bearer errors.
+
+The reference condition will be a time interval during which there are no bit-errors (i.e. error-free interval).
+
+Digital errors in the bearer channel shall be injected according to one of the following formats:
+
+- 1) random bit errors over the entire bearer representing the operating range of interest;
+- 2) random burst errors of controlled duration over the entire CME bearer channel.
+
+For the introduction of specific burst errors over the entire CME bearer a "burst-error injector" is required. Four parameters are defined:
+
+- length of burst;
+- bit-error distribution within burst;
+- frequency of burst occurrence.
+
+Random burst errors of controlled duration over the entire bearer may be generated by utilization of a burst-error generator to directly inject errors into the CME bearer channel. This method permits the corruption of N randomly distributed bits within a contiguous window of 2N bits of transmitted data. This method of burst-error generation (which are no longer specific) utilizes commercially available bit-error equipment.
+
+#### 6.4.4 Bearer conditions
+
+Four different configurations will be used.
+
+NOTE – Burst errors introduced into the return CME bearer channel are for further study.
+
+##### 6.4.4.1 BC1: Bearer Condition 1
+
+Specific burst errors capable of affecting the entire bearer are included. The types of burst errors to be used in the forward channel for these tests reflect the characteristics of the communication system being simulated.
+
+As explained in Recommendation G.826, the following characteristics need to be defined:
+
+- length of burst;
+- bit-error distribution within burst;
+- frequency of burst occurrence;
+- time interval where no bit errors are present (i.e. error-free interval).
+
+For circuit-oriented CME, if the equipment provides a mechanism for internally accessing the channel assignment maps, then these maps shall be used for the identification of the path assigned to the facsimile call. If the CME does not permit such access, "marking" errors, as described in 6.4.1.2, shall be employed. When marking errors are used, these shall be introduced either in the forward channel for standard transmission, or in the return channel when polling is employed. If marking errors are employed, the burst errors defined above shall not be utilized in the same CME bearer channel direction.
+
+The introduction of marking errors shall be undertaken so that the CME maintains synchronization. The marking errors shall be introduced once for each page of documentation transmitted.
+
+##### 6.4.4.2 BC2: Bearer Condition 2
+
+Two sets of conditions shall be exercised: the first with no impairments in the forward CME bearer channel, and the second with three types of impairment conditions. These are:
+
+- random bit errors over the entire bearer at an error rate reflecting the test-range of interest;
+- grouped errors:
+  - specific bit errors over the customer traffic-carrying bearer slots only (i.e. CME control channel excluded, assuming there is one – see 6.4.1.1);
+  - specific bit errors over the CME control channel slots only (assuming there is one – see 6.4.1.1);
+- medium-specific burst errors over the entire bearer to reflect the actual (see 6.4.1.1 and 6.4.2).
+
+### 6.5 Forward error correction
+
+Some tests will be with done with and without forward correction as shown in 6.7.
+
+### 6.6 Return echo level
+
+Some tests will be with done with and without echo level control as shown in 6.7. The values of the echo return loss will be as defined in 5.4/G.720.
+
+### 6.7 Reference conditions
+
+This subclause defines the various conditions that will be used during testing. Each condition can be the combination of some of the above subclauses. To minimize the number of tests, only the necessary combinations are listed.
+
+#### 6.7.1 Reference test condition 1
+
+The purpose of this test condition is to study the capability of CME to detect and classify facsimile signals, and to handle proprietary facsimile fall-back to ADPCM.
+
+| Access-link impairments | Traffic loading              | Delay                                                                                 | Bearer impairments | Forward error correction | Echo control                                                       |
+|-------------------------|------------------------------|---------------------------------------------------------------------------------------|--------------------|--------------------------|--------------------------------------------------------------------|
+| None                    | All seven loading conditions | <ul style="list-style-type: none"><li>• Low</li><li>• Medium</li><li>• High</li></ul> | Bearer condition 1 | OFF                      | <ul style="list-style-type: none"><li>• OFF</li><li>• ON</li></ul> |
+
+#### 6.7.2 Reference test condition 2
+
+The purpose of this condition is to study the combined effect of access link and bearer link impairments.
+
+| Access-link impairments                                                               | Traffic loading     | Delay                                                                                 | Bearer impairments | Forward error correction                                           | Echo control                                                       |
+|---------------------------------------------------------------------------------------|---------------------|---------------------------------------------------------------------------------------|--------------------|--------------------------------------------------------------------|--------------------------------------------------------------------|
+| <ul style="list-style-type: none"><li>• None</li><li>• Digital and analogue</li></ul> | Loading condition 1 | <ul style="list-style-type: none"><li>• Low</li><li>• Medium</li><li>• High</li></ul> | Bearer condition ? | <ul style="list-style-type: none"><li>• OFF</li><li>• ON</li></ul> | <ul style="list-style-type: none"><li>• OFF</li><li>• ON</li></ul> |
+
+#### 6.7.3 Reference test condition 3
+
+The purpose of this condition is to study the effect of bearer link impairments.
+
+| Access-link impairments | Traffic loading     | Delay                                                                                 | Bearer impairments | Forward error correction                                             | Echo control |
+|-------------------------|---------------------|---------------------------------------------------------------------------------------|--------------------|----------------------------------------------------------------------|--------------|
+| None                    | Loading condition 1 | <ul style="list-style-type: none"><li>• Low</li><li>• Medium</li><li>• High</li></ul> | Bearer condition 2 | <ul style="list-style-type: none"><li>• OFF</li><li>• ON ?</li></ul> | ON           |
+
+#### 6.7.4 Reference test condition 4
+
+The purpose is to test CME recovery following unexpected event during facsimile call set-up.
+
+| Access-link impairments | Traffic loading     | Delay                                                                                 | Bearer impairments | Forward error correction                                           | Echo control                                                       |
+|-------------------------|---------------------|---------------------------------------------------------------------------------------|--------------------|--------------------------------------------------------------------|--------------------------------------------------------------------|
+| PCM-Path Digital Errors | Loading condition 1 | <ul style="list-style-type: none"><li>• Low</li><li>• Medium</li><li>• High</li></ul> | None               | <ul style="list-style-type: none"><li>• OFF</li><li>• ON</li></ul> | <ul style="list-style-type: none"><li>• OFF</li><li>• ON</li></ul> |
+
+#### 6.7.5 Reference test condition 5
+
+The purpose is to study the effect of echo on voiceband data quality.
+
+| Access-link impairments | Traffic loading              | Delay                                                                                 | Bearer impairments | Forward error correction | Echo control                                                       |
+|-------------------------|------------------------------|---------------------------------------------------------------------------------------|--------------------|--------------------------|--------------------------------------------------------------------|
+| None                    | All seven loading conditions | <ul style="list-style-type: none"><li>• Low</li><li>• Medium</li><li>• High</li></ul> | None               | OFF                      | <ul style="list-style-type: none"><li>• OFF</li><li>• ON</li></ul> |
+
+#### 6.7.6 Reference test condition 6
+
+The purpose is to study the effect of facsimile protocol variability on facsimile quality.
+
+| Access-link impairments | Traffic loading                                                                                                                                     | Delay                                                                                 | Bearer impairments | Forward error correction                                           | Echo control |
+|-------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------|--------------------|--------------------------------------------------------------------|--------------|
+| None                    | From <ul style="list-style-type: none"><li>• Loading condition 1</li></ul> to <ul style="list-style-type: none"><li>• Loading condition 3</li></ul> | <ul style="list-style-type: none"><li>• Low</li><li>• Medium</li><li>• High</li></ul> | Bearer condition ? | <ul style="list-style-type: none"><li>• OFF</li><li>• ON</li></ul> | ON           |
+
+#### 6.7.7 Reference test condition 7
+
+The purpose is to study the effect of transmission level variability and echo return conditions.
+
+| Access-link impairments | Traffic loading     | Delay                                                                                 | Bearer impairments | Forward error correction | Echo control                                                       |
+|-------------------------|---------------------|---------------------------------------------------------------------------------------|--------------------|--------------------------|--------------------------------------------------------------------|
+| None                    | Loading condition 1 | <ul style="list-style-type: none"><li>• Low</li><li>• Medium</li><li>• High</li></ul> | Bearer condition ? | OFF                      | <ul style="list-style-type: none"><li>• OFF</li><li>• ON</li></ul> |
+
+Other test conditions to be considered are:
+
+- transmit levels of calling facsimile terminal varying from 0 to –40 dBm0 in 5 dB decrements;
+- primary 2- to 4-wire termination loss varying from 2 to 26 dB, in 4 dB increments.
+
+#### 6.7.8 Reference test condition 8
+
+The purpose is to test the effect of transmission integrity due to timing deviations on facsimile quality.
+
+| Access-link impairments | Traffic loading     | Delay                                                                                 | Bearer impairments | Forward error correction | Echo control |
+|-------------------------|---------------------|---------------------------------------------------------------------------------------|--------------------|--------------------------|--------------|
+| None                    | Loading condition 1 | <ul style="list-style-type: none"><li>• Low</li><li>• Medium</li><li>• High</li></ul> | None               | OFF                      | ON           |
+
+# 7 Facsimile call quality assessment
+
+The assessment of facsimile call cut-off performance shall conform to Recommendations E.450, E.451, E.452, E.453. In addition, the following performance parameters shall also be noted:
+
+- i) The data rate employed for the transmission of each document page (e.g. transmission rate employed during "Phase C" of the Group 3 facsimile protocol procedures as defined in Recommendation T.30).
+- ii) The type of post-message response issued by the receiving terminal indicating the quality of the T.30 message received (MCF, RTP, or RTN). A facsimile protocol analyser is necessary for this measurement. When such an analyser is employed, it shall be attached between the called CME and called Group 3 facsimile equipment.
+- iii) The ability to satisfactorily complete twenty 3-page calls. Other number of pages is for further study.
+
+Accordingly, the facsimile call quality shall be reported in terms of the following parameters:
+
+- 1) circuit configuration/condition number (includes loading characteristics, impairments introduced, CME systems used, calling and called facsimile terminal types, etc.);
+- 2) average number of single scan-line errors per page;
+- 3) average number of minor errors per page;
+- 4) average number of major errors per page;
+- 5) ratio of unacceptable pages to total pages transmitted;
+- 6) negotiated rate for first page transmitted;
+
+- 7) negotiated rate for last page transmitted;
+- 8) number of RTP indications issued by the called facsimile terminal;
+- 9) number of RTN indications issued by the called facsimile terminal;
+- 10) number of calls failed prior to transmission of page 1;
+- 11) number of calls failing to complete the 3-page test document transmission;
+- 12) total pages received by called facsimile terminal;
+- 13) type of facsimile path provided by CME (i.e. ADPCM encoded, demodulated).
+
+When the optional T.4 Error Correction Mode (ECM) is employed by the end-user facsimile terminals, the facsimile transmission performance indicators to be additionally reported are for further study.
+
+When the received facsimile message can be compared to the original transmitted message (Run-Length Coded) the following additional performance indicators shall be obtained:
+
+- 1) bit-error ratios;
+- 2) block-error ratios (1000 bit/block and 511 bit/block);
+- 3) distributions of lengths of error events (from the first to the last bit in error);
+- 4) distributions of the number of bits in error in the error event.
+
+# **8 Baseline measurements**
+
+Baseline measurements are required for two purposes (other than calibrating the analogue impairment channel). First, the behaviour and correct operation of the end-user facsimile terminals needs to be characterized in the absence of CME type of circuits, or channel impairments. Second, the correct operation of the CME needs to be assessed prior to undertaking facsimile tests.
+
+## **8.1 Facsimile terminal baseline tests**
+
+The behaviour and correct operation of the end-user facsimile terminals shall be characterized in the absence of CME-type of circuits, or channel impairments. There are two basic configurations defined for this purpose. In baseline configuration No. 1, the facsimile terminals are directly connected over a circuit employing 64 kbit/s PCM encoding. Attenuation or gain controls are provided, as appropriate, in order to preserve the signal levels at the facsimile terminal and PCM encoder/decoder interfaces. This baseline measurement circuit is shown in Figure 5.
+
+![Figure 5/G.511 – Facsimile terminal baseline circuit configuration No. 1. The diagram shows a circuit configuration for facsimile transmission. At the top, a horizontal arrow points right, labeled 'Direction of document transmission'. The circuit consists of two main paths between a 'Calling end' FAX terminal on the left and a 'Called end' FAX terminal on the right. Each path includes a '2- to 4-wire conversion' block. The top path contains a PCM block (labeled 1) followed by a PCM^-1 block (labeled 4). The bottom path contains a PCM^-1 block (labeled 2) followed by a PCM block (labeled 5). Two interface points, SM1 and SM2, are marked with solid black dots. SM1 is located between the PCM^-1 block (4) and the 2- to 4-wire conversion block on the top path. SM2 is located between the 2- to 4-wire conversion block and the PCM block (5) on the bottom path. Arrows indicate the flow of signal from the calling end to the called end through both paths.](8c348bf9c2c81b018017ae1d19506a9a_img.jpg)
+
+Figure 5/G.511 – Facsimile terminal baseline circuit configuration No. 1. The diagram shows a circuit configuration for facsimile transmission. At the top, a horizontal arrow points right, labeled 'Direction of document transmission'. The circuit consists of two main paths between a 'Calling end' FAX terminal on the left and a 'Called end' FAX terminal on the right. Each path includes a '2- to 4-wire conversion' block. The top path contains a PCM block (labeled 1) followed by a PCM^-1 block (labeled 4). The bottom path contains a PCM^-1 block (labeled 2) followed by a PCM block (labeled 5). Two interface points, SM1 and SM2, are marked with solid black dots. SM1 is located between the PCM^-1 block (4) and the 2- to 4-wire conversion block on the top path. SM2 is located between the 2- to 4-wire conversion block and the PCM block (5) on the bottom path. Arrows indicate the flow of signal from the calling end to the called end through both paths.
+
+T1600580-97
+
+**Figure 5/G.511 – Facsimile terminal baseline circuit configuration No. 1**
+
+Note that a local office network/simulating loop which provides ringing, voltage drop, DTMF decoding and other locally generated signals will also be required, but is not shown in the figures throughout this test methodology. It is assumed that such equipment will be provided to permit normal facsimile equipment operation.
+
+It is suggested that a facsimile protocol analyser that provides facsimile protocol signal decoding and facsimile signal activity timing be employed, at least at one end of the circuit, connected at an appropriate interface point between the facsimile terminal and the PCM equipment. Appropriate interface points for signal activity monitoring are denoted as SM1, and SM2 in Figure 5. It is recommended that the timing acquisition between points SM1 and SM2 be synchronized.
+
+In baseline configuration No. 2, Figure 6 the facsimile terminals are directly connected over a circuit employing 64 kbit/s PCM encoding and echo control equipment. In addition, simulated circuit and CME processing delay  $\tau$  is introduced between the calling and called ends (this is shown in the PCM encoded paths. The introduction of simulated delay in the analogue circuit may also be acceptable, provided that resulting echo path does not exceed any echo control processing window constraints).
+
+It is suggested that in baseline configuration No. 2, facsimile protocol analysers which provide facsimile protocol signal decoding and facsimile signal activity timing be employed, at both ends of the circuit, connected at appropriate interface points between the facsimile terminals and the PCM equipment. Appropriate interface points for signal activity monitoring are denoted as SM1, SM2, SM3, and SM4 in Figure 6. If all four points are accessed, it is recommended that, as a minimum, the timing acquisition between points SM1 and SM2 be synchronized. The synchronization of points SM3 and SM1 is also recommended.
+
+![Figure 6/G.511 – Facsimile terminal baseline circuit configuration No. 2. This block diagram illustrates the signal path between a 'Calling end' FAX and a 'Called end' FAX. A horizontal arrow at the top indicates the 'Direction of document transmission' from left to right. The signal from the Calling end FAX enters a '2- to 4-wire conversion' block. From here, the path splits into two parallel channels. The top channel consists of a PCM block (labeled 1), an Echo control block, a delay block (τ), another Echo control block, and a PCM⁻¹ block (labeled 4). The bottom channel consists of a PCM⁻¹ block (labeled 2), an Echo control block, a delay block (τ), another Echo control block, and a PCM block (labeled 5). State machines SM3 and SM4 are at the input conversion, while SM1 and SM2 are at the output conversion. The channels recombine at a second '2- to 4-wire conversion' block before reaching the 'Called end' FAX. The diagram is labeled T1600590-97.](69b7bd65e85cdef6fdd7fb0a8194257c_img.jpg)
+
+Figure 6/G.511 – Facsimile terminal baseline circuit configuration No. 2. This block diagram illustrates the signal path between a 'Calling end' FAX and a 'Called end' FAX. A horizontal arrow at the top indicates the 'Direction of document transmission' from left to right. The signal from the Calling end FAX enters a '2- to 4-wire conversion' block. From here, the path splits into two parallel channels. The top channel consists of a PCM block (labeled 1), an Echo control block, a delay block (τ), another Echo control block, and a PCM⁻¹ block (labeled 4). The bottom channel consists of a PCM⁻¹ block (labeled 2), an Echo control block, a delay block (τ), another Echo control block, and a PCM block (labeled 5). State machines SM3 and SM4 are at the input conversion, while SM1 and SM2 are at the output conversion. The channels recombine at a second '2- to 4-wire conversion' block before reaching the 'Called end' FAX. The diagram is labeled T1600590-97.
+
+**Figure 6/G.511 – Facsimile terminal baseline circuit configuration No. 2**
+
+## 8.2 CME baseline tests
+
+In addition to the facsimile terminal baseline tests, the correct operation of the CME needs to be assessed prior to undertaking facsimile tests. This can be accomplished by verifying the long term CME timing synchronization and bit integrity using a digital test pattern and data error analyser.
+
+This baseline configuration is shown in Figure 7. During these baseline measurements (it is recommended that CME synchronization be verified over a 72-hour period) related status alarms should be monitored, as appropriate, depending on the CME system's diagnostic capabilities.
+
+![Figure 7/G.511 – CME baseline circuit configuration. This block diagram shows the setup for CME baseline tests. A '64 kbit/s digital test pattern' input enters a 'Calling CME' block. An arrow connects the 'Calling CME' block to a 'Called CME' block. From the 'Called CME' block, an arrow points to a 'Data error analyser' block. A feedback loop arrow returns from the 'Data error analyser' block to the input of the 'Calling CME' block. The diagram is labeled T1600600-97.](6ca05954842b17f14dfd52f26b9d43d2_img.jpg)
+
+Figure 7/G.511 – CME baseline circuit configuration. This block diagram shows the setup for CME baseline tests. A '64 kbit/s digital test pattern' input enters a 'Calling CME' block. An arrow connects the 'Calling CME' block to a 'Called CME' block. From the 'Called CME' block, an arrow points to a 'Data error analyser' block. A feedback loop arrow returns from the 'Data error analyser' block to the input of the 'Calling CME' block. The diagram is labeled T1600600-97.
+
+**Figure 7/G.511 – CME baseline circuit configuration**
+
+# 9 Test methodology
+
+A functional block diagram of the generic experimental configuration to be used in these tests is shown in Figures 8 and 9. In this configuration,  $\tau$  represents a simulated one-way propagation delay. When the tests are conducted in a laboratory,  $\tau = 250$  ms (simulated one-way satellite propagation delay). When field tests are being undertaken,  $\tau = 0$  ms. Throughout this test-methodology, nominal transmission levels shall be employed, as indicated in Figures 8 and 9, unless otherwise noted.
+
+![Functional block diagram of the generic experimental configuration for Recommendation G.511.](fa01531ea2c45beeb4036005da3037a4_img.jpg)
+
+The diagram illustrates the functional block diagram of the generic experimental configuration for Recommendation G.511. It shows the signal flow between a Calling end and a Called end, including various impairments and processing blocks.
+
+**Legend:**
+
+- Direction of document transmission (standard) →
+- Direction of document transmission (polling) ←
+
+**Components and Signal Flow:**
+
+- Calling end:** A Fax terminal connected to a small square block. A dBm TLP measurement point is located before this block.
+- Forward Channel (Calling end to Called end):**
+  - Analogue impairments block.
+  - PCM block.
+  - Echo control block.
+  - A summing junction where  $S_{out}$  is added.
+  - Calling CME encoder block.
+  - A delay block  $\tau$ .
+  - A summing junction where Bearer impairments (forward channel) are added.
+  - Calling CME decoder block.
+  - An input signal  $R_{in}$  enters the decoder.
+- Reverse Channel (Called end to Calling end):**
+  - Calling CME encoder block.
+  - A delay block  $\tau$ .
+  - A summing junction where Bearer impairments (reverse channel) are added.
+  - Calling CME decoder block.
+  - An output signal  $S_{out}$  leaves the decoder.
+  - Echo control block.
+  - A summing junction where Digital impairments are added.
+  - PCM<sup>-1</sup> block.
+  - Analogue impairments block.
+  - A dBm TLP measurement point after this block.
+- Called end:** A Fax terminal connected to a small square block. A dBm TLP measurement point is located before this block.
+
+**dBm TLP Measurement Points:** There are four dBm TLP measurement points indicated by vertical lines: one before the first square block, one after the first analogue impairments block, one after the second analogue impairments block, and one before the second square block.
+
+Functional block diagram of the generic experimental configuration for Recommendation G.511.
+
+**Figure 8/G.511 – First example of functional block diagram of the generic experimental configuration**
+
+![Functional block diagram of the generic experimental configuration for fax transmission.](dcf37c460c66ec011dbe6ca08de44ff9_img.jpg)
+
+The diagram illustrates the functional block diagram of the generic experimental configuration for fax transmission, showing both standard and polling directions.
+
+**Legend:**
+
+- Direction of document transmission (standard): Indicated by a right-pointing arrow.
+- Direction of document transmission (polling): Indicated by a left-pointing arrow.
+
+**Block Diagram Components and Flow:**
+
+- Calling end (Fax):** Connected to a 2- to 4- wire conversion block.
+- Forward Channel (S<sub>out</sub> to R<sub>in</sub>):**
+  - 2- to 4- wire conversion block (labeled #1).
+  - Analogue impairments block (labeled #1).
+  - PCM block (labeled #1).
+  - Echo control block.
+  - Digital impairments block (input to S<sub>out</sub>).
+  - Calling CME encoder block.
+  - Bearer impairments (forward channel) block (labeled  $\tau$ ).
+  - Calling CME decoder block.
+- Reverse Channel (R<sub>in</sub> to S<sub>out</sub>):**
+  - Calling CME decoder block.
+  - Bearer impairments (reverse channel) block (labeled  $\tau$ ).
+  - Calling CME encoder block.
+  - Echo control block.
+  - PCM<sup>-1</sup> block (labeled #2).
+  - Analogue impairments block (labeled #2).
+  - 2- to 4- wire conversion block.
+- Called end (Fax):** Connected to a 2- to 4- wire conversion block.
+- Intermediate Blocks:**
+  - PCM<sup>-1</sup> block (labeled #4).
+  - Analogue impairments block (labeled #4).
+  - PCM block (labeled #5).
+  - Digital impairments block (input to S<sub>out</sub>).
+  - PCM<sup>-1</sup> block (labeled #2).
+  - Analogue impairments block (labeled #2).
+
+Functional block diagram of the generic experimental configuration for fax transmission.
+
+T1600620-97
+
+Figure 9/G.511 – Second example of functional block diagram of the generic experimental configuration
+
+# ANNEX A
+
+## Group 3 facsimile procedures
+
+### A.1 Group 3 facsimile recognition: detection and classification
+
+#### A.1.1 Objective
+
+When a Group 3 facsimile call is initiated, and if a demodulation/remodulation capability is provided by both the calling and called CMEs, the call will be routed to the demodulated path shortly after its establishment. The decision process that dictates when the facsimile call will be switched to the demodulated path may vary between CME systems, although the demodulated path is likely to be used shortly after the completion of the Phase A procedures defined in Recommendation T.30 [e.g. no later than following the transmission of the Digital Command Signal (DCS) by the calling facsimile terminal]. The objective of these tests is to determine the facility selection reliability, or alternatively whether, and under what circuit or CME loading conditions, is a demodulated path selected when a compatible facsimile call is being established.
+
+#### A.1.2 Settings
+
+Facsimile terminal configuration:
+
+Group 3 facsimile terminal in configuration Std/Conf/3 will be selected (see 5.1.3).
+
+#### A.1.3 Test conditions
+
+Use reference test condition 1, as defined in 6.7.1.
+
+#### A.1.4 Parameters of investigation
+
+The following parameters shall be varied during these tests:
+
+- direction of transmission (normal and polling);
+- type of burst characteristics in the CME bearer channels; and
+- loading characteristics of calling and called CMEs.
+
+#### A.1.5 Monitoring/measurement points
+
+If the CMEs provide a mechanism for internally accessing the channel assignment maps, then these maps shall be used for the identification of the path (or facility) assigned to the facsimile call, as stated above. Otherwise, marking errors may be employed (depending on CME design), and the received RLC encoded bit-image shall be compared against the transmitted RLC encoded bit-image to determine the presence (or absence) of error-multiplication effects.
+
+### A.2 Proprietary facsimile fall-back to ADPCM path
+
+#### A.2.1 Objective
+
+When a Group 3 facsimile call is initiated, and if a demodulated path can be provided by both the calling and called CMEs, the call will be routed through the demodulated path during or after its establishment. The demodulated path is likely to be used shortly after the completion of the Phase A procedures defined in Recommendation T.30 [e.g. no later than following the transmission of the Digital Command Signal (DCS) by the calling facsimile terminal]. The decision process which dictates when the facsimile call will be switched to the demodulated path may vary between CME systems. In addition, the capability to accommodate proprietary facsimile transmissions over the
+
+demodulated signal path may be limited and, in certain cases, fall-back into the ADPCM encoded path may be necessary if the facsimile mode of negotiated communication is incompatible with the CME demodulated path capabilities. The objective of these tests will be to determine whether, and under what circuit or CME loading conditions, a selected demodulated path will be substituted by an ADPCM encoded path when a incompatible facsimile call (initially through demodulated path) is established following the completion of T.30/Phase A.
+
+#### **A.2.2 Settings**
+
+##### **A.2.2.1 Facsimile terminal configuration**
+
+Non-standard Group 3 facsimile mode 2 (see 5.2.2) terminals shall be selected. Experimentation (or collaboration with the CME system manufacturer) may be required to select a suitable pair of terminals.
+
+##### **A.2.2.2 Mode of transmission**
+
+Two modes are defined:
+
+- The calling terminal which initiates the communication (e.g. by transmitting the CNG tone to the called terminal) wishes to transmit to the called terminal (standard configuration);
+- The calling terminal which initiates the communication (e.g. by transmitting the CNG tone to the called terminal) wishes to receive from the called terminal (polling configuration).
+
+#### **A.2.3 Test conditions**
+
+Use reference test condition 1, as defined in 6.7.1.
+
+#### **A.2.4 Parameters of investigation**
+
+From the above it can be seen that the following parameters will be varied during these tests:
+
+- direction of transmission (normal and polling);
+- type of burst characteristics in the CME bearer channel; and
+- loading characteristics of calling and called CMEs.
+
+#### **A.2.5 Monitoring/measurement points**
+
+The same procedures shall be used as those defined for the tests of A.9.4.
+
+### **A.3 Group 3 facsimile image quality in presence of combined access link and bearer link impairments**
+
+#### **A.3.1 Objective**
+
+The objective of these tests will be to evaluate the impact of access link degradation on facsimile quality over different CME processing path conditions and in the presence of nominal CME bearer impairments.
+
+#### **A.3.2 Settings**
+
+##### **A.3.2.1 CME configuration**
+
+When the CMEs provide alternate paths for the transmission of facsimile that can be selected (such as compressed with error protection, compressed without error protection, and ADPCM encoded) the paths shall be separately exercised.
+
+##### **A.3.2.2 Facsimile terminal configuration**
+
+Group 3 facsimile terminal in Std/Conf/1 or Std/Conf/2 configuration will be selected (see 5.1.1 and 5.1.2).
+
+#### **A.3.3 Test conditions**
+
+Use reference test condition 2, as defined in 6.7.2.
+
+#### **A.3.4 Monitoring/measurement points**
+
+The quality of the facsimile image transmission is monitored at the called facsimile terminal in accordance with the methods defined in clause 4.
+
+### **A.4 Group 3 facsimile image quality in presence of bearer link impairments**
+
+#### **A.4.1 Objective**
+
+The objective of these tests is to evaluate the impact of CME bearer degradation on facsimile quality over different CME processing path conditions as a function of CME access link impairments.
+
+#### **A.4.2 Settings**
+
+##### **A.4.2.1 CME configuration**
+
+When the CMEs provide selectable alternate paths for the transmission of facsimile (such as compressed with error protection, compressed without error protection, and ADCPM encoded) the paths shall be separately exercised.
+
+##### **A.4.2.2 Facsimile terminal configuration**
+
+Group 3 facsimile terminal in Std/Conf/1 or Std/Conf/2 configurations will be selected (see 5.1.1 and 5.1.2).
+
+#### **A.4.3 Test conditions**
+
+Use reference test condition 3, as defined in 6.7.3.
+
+#### **A.4.4 Monitoring/measurement points**
+
+The quality of the facsimile image transmission is monitored at the called facsimile terminal in accordance with the methods defined in clause 4.
+
+### **A.5 CME recovery following unexpected events during facsimile call progress**
+
+#### **A.5.1 Objective**
+
+The purpose of this test is to assess the adaptability of CME behaviour when the progression of a facsimile call is disturbed, either by premature facsimile terminal disconnection, or by unexpected signal-type transmissions resulting from a procedural signal corruption between the calling CME and the calling facsimile terminal (see Figures A.1 and A.2 for an example of an unexpected signal-type transmission).
+
+#### **A.5.2 Settings**
+
+Facsimile terminal configuration:
+
+Group 3 facsimile terminal in Std/Conf/1 configuration will be selected (see 5.1.1).
+
+#### A.5.3 Test conditions
+
+Use reference test condition 4, as defined in 6.7.4.
+
+Other test conditions to be considered:
+
+Two test conditions are defined. First, corruption of the Confirmation to Receive (CFR) signal in the T.30 sequence is introduced between the calling CME and the calling facsimile terminal. Second, the call is prematurely terminated and the recovery of the CME equipment is observed. (It is noted that these tests may be more easily conducted using the protocol test set described in A.7.2.2).
+
+![Sequence diagram showing T.30 normal signal transaction in the presence of CME.](9870bf462aa0d916a16d14b5a100c60a_img.jpg)
+
+The diagram illustrates the T.30 normal signal transaction in the presence of CME. It features four vertical lifelines: Calling fax, Calling CME, Called CME, and Called fax. The sequence of messages is as follows:
+
+- Calling fax sends a message to Calling CME.
+- Calling CME sends a message to Called CME.
+- Called CME sends a message to Called fax labeled DCS.
+- Called CME sends a message to Called fax labeled Training/TCF.
+- Called fax sends a message to Called CME labeled CFR.
+- Called CME sends a message to Calling CME.
+- Calling CME sends a message to Calling fax.
+- Calling CME sends a message to Called CME.
+- Called CME sends a message to Called fax labeled Training/Message.
+
+T1600630-97
+
+Sequence diagram showing T.30 normal signal transaction in the presence of CME.
+
+**Figure A.1/G511 – T.30 normal signal transaction in the presence of CME**
+
+![Sequence diagram showing T.30 signal transaction between Calling fax, Calling CME, Called CME, and Called fax. The diagram illustrates the flow of DCS, Training/TCF, and CFR signals, with a break in the sequence indicated by a jagged line. Jagged line symbol](e451401f8fa77b466f401d5fce15b26c_img.jpg)
+
+The diagram shows a sequence of messages between four entities: Calling fax, Calling CME, Called CME, and Called fax. The messages are as follows:
+
+- Calling fax sends a message to Calling CME.
+- Calling CME sends a message to Called CME.
+- Called CME sends a message to Called fax, labeled DCS.
+- Calling fax sends a message to Calling CME.
+- Calling CME sends a message to Called CME.
+- Called CME sends a message to Called fax, labeled Training/TCF.
+- Called fax sends a message to Called CME, labeled CFR.
+- Called CME sends a message to Calling CME.
+- Calling CME sends a message to Calling fax, labeled with a jagged line indicating an invalid frame.
+- Calling fax sends a message to Calling CME.
+- Calling CME sends a message to Called CME.
+- Called CME sends a message to Called fax, labeled DCS.
+
+Legend: Indicates an invalid frame.
+
+T1600640-97
+
+Sequence diagram showing T.30 signal transaction between Calling fax, Calling CME, Called CME, and Called fax. The diagram illustrates the flow of DCS, Training/TCF, and CFR signals, with a break in the sequence indicated by a jagged line. Jagged line symbol
+
+**Figure A.2/G.511 – T.30 signal transaction in the presence of CME when CFR signal is corrupted**
+
+### **A.6 Voiceband data quality**
+
+#### **A.6.1 Objective**
+
+The objective of these tests is to verify that voiceband data are assigned to an appropriate CME facility, and are not directed to a demodulated facsimile path unless this is fully compatible with the modulation scheme and protocols used by the end-user terminal.
+
+#### **A.6.2 Settings**
+
+Facsimile terminal configuration:
+
+No facsimile terminals are employed. Instead, the following modems are used in a two-wire dial-up configurations:
+
+- V.27 *ter* operating at 4.8 kbit/s;
+- V.17 operating at 14.4 and 12 kbit/s;
+- V.29 operating at 9.6 kbit/s.
+
+Other rates are for further study.
+
+#### **A.6.3 Test conditions**
+
+Use reference test condition 5, as defined in 6.7.5.
+
+#### **A.6.4 Monitoring/measurement points**
+
+The integrity of the transmission shall be determined by computation of the received data bit (or block) error rate, and by comparison of this against available Modem/ADPCM codec performance data. Alternatively, a simpler monitoring configuration may be used whereby the CME
+
+routing of the voiceband data channel can be determined by examination of the CME channel assignment data, if accessible.
+
+### **A.7 Effect of Group 3 facsimile protocol variability**
+
+#### **A.7.1 Objective**
+
+Recommendation T.30 leaves considerable margin in the implementation of conformant terminals operating in Group 3 mode. In addition, many terminals purposely violate Recommendation T.30 in minor ways in order to overcome inherent limitations arising, primarily, from incorrect provisioning of echo control devices. In this, the impact of Group 3 facsimile protocol variability on the behaviour of CME systems and associated impact on facsimile quality will be addressed.
+
+#### **A.7.2 Settings**
+
+##### **A.7.2.1 Facsimile terminal configuration**
+
+Group 3 facsimile terminal in Std/Conf/2 configuration will be selected.
+
+##### **A.7.2.2 Instrumentation**
+
+A facsimile test-set is required to study the effect of Group 3 facsimile protocol variation on CME and facsimile terminal behaviour. The facsimile protocol test set comprises a tool capable of operating in a real-time baseband facsimile signal domain so that signals and protocols exchanged between two facsimile terminals may be modified under operator control on a selective basis. (Note that test 9 may be administered more conveniently using such a facsimile protocol test-set). A functional configuration of such a device (as well as the suggested location of the instrumentation) is shown in Figure A.3. In Figure A.3 only the calling side of the test configuration is shown. The called side remains configured in accordance with the functional diagram shown in Figure 8.
+
+#### **A.7.3 Test conditions**
+
+Use reference test condition 6, as defined in 6.7.6.
+
+#### **A.7.4 Parameters of investigation**
+
+The following test conditions will be investigated with these tests.
+
+NOTE – Cases marked with an asterisk (\*) shall be tested with the different times of delay: (low/medium/long).
+
+- Variation of T.30 signal timing
+  - Adjacent signals\*
+  - Response signals\*
+- Selective degradation of message content
+  - High-Speed message signals
+  - Training check sequence\*
+  - Binary coded handshaking signals\*
+- Addition or deletion of handshaking signal preamble\*
+- Addition, removal, or alteration of handshaking signal units\*
+- Enforcement of specific facsimile terminal negotiation constraints
+
+- Addition and removal of echo protection tones in the following signal exchanges:
+  - Training/TCF\*
+  - Training/Message signals\*
+
+### A.8 Effect of transmission level and echo return loss
+
+#### A.8.1 Objective
+
+The objective is to observe the effect of the reconstructed image.
+
+#### A.8.2 Settings
+
+Facsimile terminal configuration:
+
+Group 3 facsimile terminal in Std/Conf/2 configuration will be selected.
+
+#### A.8.3 Test conditions
+
+Use reference test condition 7, as defined in 6.7.7.
+
+#### A.8.4 Parameters of investigation
+
+Two primary parameters are varied in this investigation. The first is the called facsimile terminal transmission level. The second is the 2- to 4-wire termination loss interconnecting the called CME with the called facsimile terminal. The configuration where these parameters are to be varied is shown in Figure A.3 (In Figure A.3 only the called side of the test configuration is shown. The calling side remains configured in accordance with the functional diagram shown in Figure 8).
+
+![Figure A.3/G.511 – Test configuration for level/loss tests (End of test configuration only shown). The diagram shows the signal path from the Called CME fax demodulation block to the Called CME fax remodulation block. The signal path includes an Echo control block, PCM blocks, and a Primary 2- to 4- wire conversion block. Optional digital impairments are added at two points. The signal is labeled R_in and S_out. The diagram is labeled T1600650-97.](187bba66c887c745c512add37a577c5e_img.jpg)
+
+The diagram illustrates the test configuration for level/loss tests, showing the end of the test configuration. It includes the following components and connections:
+
+- Called CME fax demodulation** block (top left) outputs  $R_{in}$  to the **Echo control** block.
+- Echo control** block outputs  $S_{out}$  to the **Called CME fax remodulation** block (bottom left).
+- The signal path from **Echo control** to **Called CME fax remodulation** passes through:
+  - Optional digital impairments** (input from above).
+  - PCM<sup>-1</sup>** block (labeled 4).
+  - Primary 2- to 4- wire conversion** block.
+  - PCM** block (labeled 5).
+  - Optional digital impairments** (input from below).
+- The signal path from **Called CME fax remodulation** to **Called end** (FAX) passes through the **Primary 2- to 4- wire conversion** block.
+
+The diagram is labeled T1600650-97.
+
+Figure A.3/G.511 – Test configuration for level/loss tests (End of test configuration only shown). The diagram shows the signal path from the Called CME fax demodulation block to the Called CME fax remodulation block. The signal path includes an Echo control block, PCM blocks, and a Primary 2- to 4- wire conversion block. Optional digital impairments are added at two points. The signal is labeled R\_in and S\_out. The diagram is labeled T1600650-97.
+
+**Figure A.3/G.511 – Test configuration for level/loss tests  
+(End of test configuration only shown)**
+
+#### A.8.5 Monitoring/measurement points
+
+The called CME input channel activity detectors shall be monitored when a facsimile (half-duplex) signal is being sent from the calling to the called facsimile terminal. If direct (or indirect) monitoring
+
+of the activity detector output is not possible, the signal output of the calling CME decoder shall be monitored.
+
+### **A.9 Impact of transmission integrity due to timing deviations on facsimile call quality**
+
+#### **A.9.1 Objective**
+
+The objective of this test is to assess the integrity of communication when the CME demodulated facility is used and the length of transmitted document exceeds the average page length of 30 seconds. In this manner, the provision of adequate message buffering required to accommodate the independence of the bearer and facsimile terminal clocks can be verified.
+
+#### **A.9.2 Settings**
+
+##### **A.9.2.1 CME configuration**
+
+When the CMEs provide selectable alternate paths for the transmission of facsimile, the demodulated path shall only be exercised.
+
+##### **A.9.2.2 Transmitted document characteristics**
+
+The same tests pages as defined in 4.4 shall be employed for reference (baseline) measurements. Documents of different lengths conformant to the characteristics defined in clause 3 shall however be used to verify the page integrity as a function of page length.
+
+#### **A.9.3 Test conditions**
+
+Use reference test condition 8, as defined in 6.7.8.
+
+#### **A.9.4 Monitoring/measurement points**
+
+The quality of the facsimile image transmission is monitored at the called facsimile terminal in accordance with the methods defined in clause 4.
+
+### **A.10 Items for further study**
+
+This subclause summarizes the different points that have been identified as potential items in future revisions of this Recommendation.
+
+#### **A.10.1 Rates and modulation schemes**
+
+- V.29 at 7200 bit/s and 9600 bit/s;
+- V.27 *ter* at 4800 bit/s;
+- V.27 *ter* at 2400 bit/s;
+- V.34;
+- V.17.
+
+#### **A.10.2 Facsimile quality assessment**
+
+The ability to satisfactorily complete twenty calls with a number of pages different from 3.
+
+The facsimile transmission performance indicators to be additionally reported, when the optional T.4 Error Correction Mode (ECM) is employed.
+
+#### **A.10.3 Coding algorithms**
+
+Testing of CME with other voice coding algorithms, e.g. G.728 and G.729, is for further study.
+
+#### **A.10.4 Errors**
+
+The entire bearer stream of one (and only one) CME frame is impaired so that every bit (preferably excluding any CME control channels) is in error. The type of frame to be in error is for further study and may be CME terminal dependent.
+
+Burst errors introduced into the return CME bearer channel.
+
+Impairments introduced into the return CME bearer channel.
+
+#### **A.10.5 CME networks**
+
+The issues related to the tandeming of CMEs.
+
+#### **A.10.6 Other SPNE**
+
+Other types of SPNE, such as devices for automatic level control, are for further study.
+
+# **APPENDIX I**
+
+## **Identifying a demodulated call in a DCME**
+
+The purpose of this appendix is to suggest a method for determining if a specific call passed through the facsimile demodulation/remodulation path. The method is non-intrusive and is simple to implement.
+
+### **I.1 Principles**
+
+When a facsimile call is switched to the demodulation/remodulation path, an additional delay is introduced. The specific delay is of between 70 and 100 ms.
+
+In a DCME, the switch is after the originating endpoint DCME sees the DIS signal transmitted by the called fax machine. Monitoring this additional delay can be used to determine if a specific call passes through the facsimile demod/remod path.
+
+One of the following methods can be used:
+
+#### – **Method 1**
+
+Measure end-to-end delay of the DIS signal and of the next V.21 signal transmitted from the called to calling side (CFR signal in case of a normally progressing call) and compare the two values. The delay is measured between measurement points ① and ② in Figure I.1.
+
+#### – **Method 2**
+
+Measure the gap between the DIS signal and the next V.21 signal transmitted from the called to calling side. The measurements are performed at the transmitting side (measurement point ①) and at the receiving side (measurement point ②). The values are then compared to see if the difference is about 100 ms.
+
+When the two CMEs are not located in the same geographical site, it should be possible to configure DCME 2 to split and loopback the incoming channel over a clear (preassigned) channel back to DCME 1 and use measurement point ③ instead of ②. The additional delay over the path between ② and ③ remains constant for the entire measurement procedure so the method is still valid.
+
+![Figure I.1/G.511 – Measurement set-up diagram. The diagram shows a communication setup between two fax machines. On the left, a fax machine is connected to a 2w/4w converter, which is connected to CME 1. On the right, a fax machine is connected to a 4w/2w converter, which is connected to CME 2. CME 1 and CME 2 are connected to each other. There are also feedback loops from CME 1 to the 2w/4w converter and from CME 2 to the 4w/2w converter. The reference T1600660-97 is noted at the bottom right.](9a5927586a691c4908aa2cf98bd47ebb_img.jpg)
+
+Figure I.1/G.511 – Measurement set-up diagram. The diagram shows a communication setup between two fax machines. On the left, a fax machine is connected to a 2w/4w converter, which is connected to CME 1. On the right, a fax machine is connected to a 4w/2w converter, which is connected to CME 2. CME 1 and CME 2 are connected to each other. There are also feedback loops from CME 1 to the 2w/4w converter and from CME 2 to the 4w/2w converter. The reference T1600660-97 is noted at the bottom right.
+
+**Figure I.1/G.511 – Measurement set-up**
+
+### **I.2 Implementation**
+
+#### **– Method 1**
+
+Connect the two measurement points to two channels of a digital oscilloscope. Set the sweep trigger to measurement point ① and use Single Scan mode (i.e. after the scope is triggered, it performs one scan and stops). Set the time span to the time between the DIS and the next V.21 signal from the called machine plus the end-to-end delay. Start the fax transaction and use the DIS to trigger the single scan. Use the scope markers to measure the end-to-end delays.
+
+#### **– Method 2**
+
+A facsimile protocol analyser identifies each signal in a facsimile call protocol, its length (in seconds) and the duration of silence gaps between each pair of consecutive signals. Use one at each measurement point and compare the readouts for the duration of the silence gaps between the DIS and the following V.21 signal at both ends.
+
+# **Bibliography**
+
+DIMOLITSAS (S.), CORCORAN (F.L.), ONUFRY (M.), SUYDERHOUD (H.G.): Evaluation of ADPCM Coders for Digital Circuit Multiplication Equipment, *COMSAT Technical Review*, Vol. 17, No. 2, 1987.
+
+
+
+# ITU-T RECOMMENDATIONS SERIES
+
+|                 |                                                                                                                                |
+|-----------------|--------------------------------------------------------------------------------------------------------------------------------|
+| Series A        | Organization of the work of the ITU-T                                                                                          |
+| Series B        | Means of expression: definitions, symbols, classification                                                                      |
+| Series C        | General telecommunication statistics                                                                                           |
+| Series D        | General tariff principles                                                                                                      |
+| Series E        | Overall network operation, telephone service, service operation and human factors                                              |
+| Series F        | Non-telephone telecommunication services                                                                                       |
+| <b>Series G</b> | <b>Transmission systems and media, digital systems and networks</b>                                                            |
+| Series H        | Audiovisual and multimedia systems                                                                                             |
+| Series I        | Integrated services digital network                                                                                            |
+| Series J        | Transmission of television, sound programme and other multimedia signals                                                       |
+| Series K        | Protection against interference                                                                                                |
+| Series L        | Construction, installation and protection of cables and other elements of outside plant                                        |
+| Series M        | TMN and network maintenance: international transmission systems, telephone circuits, telegraphy, facsimile and leased circuits |
+| Series N        | Maintenance: international sound programme and television transmission circuits                                                |
+| Series O        | Specifications of measuring equipment                                                                                          |
+| Series P        | Telephone transmission quality, telephone installations, local line networks                                                   |
+| Series Q        | Switching and signalling                                                                                                       |
+| Series R        | Telegraph transmission                                                                                                         |
+| Series S        | Telegraph services terminal equipment                                                                                          |
+| Series T        | Terminals for telematic services                                                                                               |
+| Series U        | Telegraph switching                                                                                                            |
+| Series V        | Data communication over the telephone network                                                                                  |
+| Series X        | Data networks and open system communications                                                                                   |
+| Series Y        | Global information infrastructure                                                                                              |
+| Series Z        | Programming languages                                                                                                          |
\ No newline at end of file
diff --git a/marked/T/T-REC-T.50-199209-I_PDF-E/raw.md b/marked/T/T-REC-T.50-199209-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..26f866d322e342dba6cc82d34c2ea493e2938ef2
--- /dev/null
+++ b/marked/T/T-REC-T.50-199209-I_PDF-E/raw.md
@@ -0,0 +1,764 @@
+
+
+![ITU logo: a globe with the letters ITU inside, crossed by a lightning bolt.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg)
+
+ITU logo: a globe with the letters ITU inside, crossed by a lightning bolt.
+
+INTERNATIONAL TELECOMMUNICATION UNION
+
+# CCITT
+
+THE INTERNATIONAL  
+TELEGRAPH AND TELEPHONE  
+CONSULTATIVE COMMITTEE
+
+## T.50
+
+(09/92)
+
+**TERMINAL EQUIPMENT AND PROTOCOLS  
+FOR TELEMATIC SERVICES**
+
+---
+
+**INTERNATIONAL REFERENCE  
+ALPHABET (IRA)**
+
+(FORMERLY INTERNATIONAL ALPHABET No. 5 or IA5)
+
+**INFORMATION TECHNOLOGY –  
+7-BIT CODED CHARACTER SET  
+FOR INFORMATION INTERCHANGE**
+
+![CCITT logo: a globe with the letters CCITT inside.](1d7527f4316cfe2d342b08d1653d1592_img.jpg)
+
+CCITT logo: a globe with the letters CCITT inside.
+
+**Recommendation T.50**
+
+---
+
+# FOREWORD
+
+The CCITT (the International Telegraph and Telephone Consultative Committee) is a permanent organ of the International Telecommunication Union (ITU). CCITT is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis.
+
+The Plenary Assembly of CCITT which meets every four years, establishes the topics for study and approves Recommendations prepared by its Study Groups. The approval of Recommendations by the members of CCITT between Plenary Assemblies is covered by the procedure laid down in CCITT Resolution No. 2 (Melbourne, 1988).
+
+Recommendation (revised) T.50 was prepared by Study Group VIII and was approved under the Resolution No. 2 procedure on the 18th of September 1992.
+
+# --- CCITT NOTES
+
+- 1) In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized private operating agency.
+- 2) A list of abbreviations used in this Recommendation can be found in Annex C.
+
+# **INTERNATIONAL REFERENCE ALPHABET (IRA)**
+
+(Formerly International Alphabet No. 5 or IA5)
+
+# **Information technology – 7-bit coded character set for information interchange**
+
+*(revised 1992)*
+
+## **1 Scope**
+
+1.1 This Recommendation specifies a set of 128 characters, (control characters and graphic characters such as letters, digits and symbols) with their coded representation. Most of these characters are mandatory and unchangeable, but provision is made for some flexibility to accommodate national and other requirements.
+
+1.2 This Recommendation specifies a 7-bit coded character set with a number of options. It also provides guidance on how to exercise the options to define specific national versions and application-oriented versions. Furthermore, it specifies the International Reference Version (IRV) in which such options have been exercised.
+
+1.3 This character set is primarily intended for the interchange of information among data processing systems and associated equipment, and within data communication systems. The need for graphic characters and control functions in data processing has also been taken into account in determining this character set.
+
+1.4 This character set is applicable to alphabets of the Latin script.
+
+1.5 This character set allows the use of control characters for code extension where its character set is insufficient for particular applications. Procedures for the use of these control characters are specified in ISO 2022.
+
+1.6 The definitions of the control characters mentioned in this Recommendation are specified in Annex A. It is assumed that data associated with them are to be processed serially in a forward direction. When they are included in strings of data which are processed other than serially in a forward direction, or when they are included in data formatted for fixed-record processing, they may have undesirable effects or may require additional special treatment to ensure that they result in their desired function.
+
+1.7 This is a paired Recommendation/International Standard, equivalent in technical content to ISO/IEC 646 (1991).
+
+## **2 Conformance and implementation**
+
+### *2.1 Conformance*
+
+#### *2.1.1 Conformance of information interchange*
+
+A coded-character-data-element (CC-data-element) within coded information for interchange is in conformance with this Recommendation if all the coded representations of characters within that CC-data-element conform to the requirements of § 8.1.
+
+A claim of conformance shall identify the version adopted in accordance with §§ 8.2 to 8.4.
+
+#### 2.1.2 *Conformance of devices*
+
+A device is in conformance with this Recommendation if it conforms to the requirements of § 2.1.2.1, and either or both of §§ 2.1.2.2 and 2.1.2.3 below. A claim of conformance shall identify the version adopted.
+
+##### 2.1.2.1 *Device description*
+
+A device that conforms to this Recommendation shall be the subject of a description that identifies the means by which the user may supply characters to the device, or may recognize them when they are made available to the user, as specified respectively in §§ 2.1.2.2 and 2.1.2.3 below.
+
+##### 2.1.2.2 *Originating devices*
+
+An originating device shall allow its user to supply any sequence of characters from the version adopted, and shall be capable of transmitting their coded representations within a CC-data-element.
+
+##### 2.1.2.3 *Receiving devices*
+
+A receiving device shall be capable of receiving and interpreting any coded representations of characters that are within a CC-data-element, and that conform to § 2.1.1, and shall make the corresponding characters available to its user in such a way that the user can identify them from among those of the version adopted, and can distinguish them from each other.
+
+## 2.2 *Implementation*
+
+The use of this character set requires definitions of its implementation in various media. For example, these could include punched tapes, punched cards, magnetic and optical interchangeable media and transmission channels, thus permitting interchange of data to take place either indirectly by means of an intermediate recording on a physical medium, or by local connection of various units (such as input and output devices and computers) or by means of data transmission equipment.
+
+The implementation of this coded character set in physical media and for transmission, taking into account the need for error checking, is the subject of other Recommendations.
+
+## 3 **Normative references**
+
+The following standards contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this Recommendation are encouraged to investigate the possibility of applying the most recent editions of the standards listed below.
+
+ISO 2022: 1986 *Information processing – ISO 7-bit and 8-bit coded character sets – Coded extension techniques.*
+
+## 4 **Definitions**
+
+For the purpose of this Recommendation the following definitions apply.
+
+### 4.1 **active position**
+
+The character position which is to image the graphic symbol representing the next graphic character or relative to which the next control function is to be executed.
+
+*Note* – In general, the active position is indicated by a cursor.
+
+### 4.2 **bit combination**
+
+An ordered set of bits used for the representation of characters.
+
+### 4.3 **character**
+
+A member of a set of elements used for the organization, control or representation of data.
+
+### 4.4 **character position**
+
+The portion of a display that is imaging or is capable of imaging a graphic symbol.
+
+### 4.5 **coded character set; code**
+
+A set of unambiguous rules that establishes a character set and the one-to-one relationship between the characters of the set and their representation by one or more bit combinations.
+
+### 4.6 **coded character-data-element (CC-data-element)**
+
+An element of interchanged information that is specified to consist of a sequence of coded representations of characters, in accordance with one or more identified standards for coded character sets.
+
+*Note 1* – In a communication environment according to the Reference Model for Open Systems Interconnection of Recommendation X.200 (ISO 7498) a CC-data-element will form all or part of the information that corresponds to the application user data and the presentation protocol data unit (PPDU) defined in that Recommendation.
+
+*Note 2* – When information interchange is accomplished by means of interchangeable media, a CC-data-element will form all or part of the information that corresponds to the user data, and not that recorded during formatting and initialization.
+
+### 4.7 **code extension**
+
+The techniques for the encoding of characters that are not included in the character set of a given code.
+
+### 4.8 **code table**
+
+A table showing the character allocated to each bit combination in a code.
+
+## 4.9 **control character**
+
+A control function the coded representation of which consists of a single bit combination.
+
+## 4.10 **control function**
+
+An action that affects the recording, processing, transmission or interpretation of data and that has a coded representation consisting of one or more combinations.
+
+### 4.11 **device**
+
+A component of information processing equipment which can transmit, and/or can receive, coded information within CC-data-elements.
+
+*Note* – It may be an input/output device in the conventional sense, or a process such as an application program or gateway function.
+
+### 4.12 **graphic character**
+
+A character, other than a control function, that has a visual representation normally handwritten, printed or displayed, and that has a coded representation consisting of one or more bit combinations.
+
+### 4.13 **graphic symbol**
+
+A visual representation of a graphic character or of a control function.
+
+### 4.14 **position**
+
+That part of a code table identified by its column and row co-ordinates.
+
+### 4.15 **repertoire**
+
+A specified set of characters that are represented by means of one or more bit combinations of a coded character set.
+
+### 4.16 **user**
+
+A person or other entity that invokes the services provided by a device.
+
+*Note 1* – This entity may be a process such as an application program if the “device” is a code convertor or a gateway function, for example.
+
+*Note 2* – The characters, as supplied by the user or made available to the user, may be in the form of codes local to the device, or of non-conventional visible representations, provided that § 2.1.2 above is satisfied.
+
+## 5 **Notation, code table and names**
+
+### 5.1 *Notation*
+
+The bits of the bit combinations of the 7-bit code are identified by  $b_7$ ,  $b_6$ ,  $b_5$ ,  $b_4$ ,  $b_3$ ,  $b_2$ , and  $b_1$ , where  $b_7$  is the highest-order, or most-significant, bit and  $b_1$  is the lowest order, or least-significant, bit.
+
+The bit combination may be interpreted to represent integers in the range 0 to 127 in binary notation by attributing the following weights to the individual bits:
+
+| Bit    | $b_7$ | $b_6$ | $b_5$ | $b_4$ | $b_3$ | $b_2$ | $b_1$ |
+|--------|-------|-------|-------|-------|-------|-------|-------|
+| Weight | 64    | 32    | 16    | 8     | 4     | 2     | 1     |
+
+In this Recommendation, the bit combinations are identified by notations of the form  $x/y$ , where  $x$  is a number in the range 0 to 7 and  $y$  is a number in the range 0 to 15. The correspondence between the notations of the form  $x/y$  and the bit combinations consisting of the bits  $b_7$  to  $b_1$  is as follows:
+
+- $x$  is the number represented by  $b_7$ ,  $b_6$ , and  $b_5$ , where these bits are given the weights 4, 2 and 1 respectively;
+- $y$  is the number represented by  $b_4$ ,  $b_3$ ,  $b_2$ , and  $b_1$ , where these bits are given the weights 8, 4, 2 and 1 respectively.
+
+The notations of the form  $x/y$  are the same as those used to identify code table positions, where  $x$  is the column number and  $y$  the row number (see § 9).
+
+### 5.2 *Code table*
+
+A 7-bit code table consists of 128 positions arranged in 8 columns and 16 rows. The columns are numbered 0 to 7 and the rows 0 to 15.
+
+The code table positions are identified by notations of the form  $x/y$ , where  $x$  is the column number and  $y$  is the row number.
+
+The position of the code table is in one-to-one correspondence with the bit combinations of the code. The notation of a code table position, of the form  $x/y$ , is the same as that of the corresponding bit combination.
+
+The allocation of individual characters to the bit combinations of the 7-bit code is specified in §§ 6.2 to 6.5.
+
+### 5.3 *Names*
+
+This Recommendation assigns one name to each character. In addition, it specifies an acronym for each control character and for the character SPACE, and a graphic symbol for each graphic character. By convention, only capital letters, space and hyphen are used for writing the names of the characters. For acronyms only capital letters and digits are used. It is intended that the acronyms and this convention be retained in all translation of the text.
+
+The names chosen to denote graphic characters are intended to reflect their customary meaning. However, this Recommendation does not define and does not restrict the meanings of graphic characters. Neither does it specify a particular style or font design for the graphic characters when imaged.
+
+## 6 **Specification of the coded character set**
+
+### 6.1 *Structure*
+
+The coded character set of this Recommendation shall have the following structure:
+
+- a C0 control character set of up to 32 control characters allocated to positions 0/0 to 1/15;
+- the graphic character SPACE (SP) allocated to position 2/0;
+- a G0 graphic character set of up to 94 graphic characters allocated to positions 2/1 to 7/14;
+- the character DELETE (DEL) allocated to position 7/15.
+
+### 6.2 *Control characters*
+
+The control characters allocated to positions 0/0 to 1/15 shall be as specified in Annex A.
+
+### 6.3 *Character SPACE*
+
+The acronym of the character SPACE is SP and its coded representation is 2/0.
+
+This character is a graphic character; it has a visual representation consisting of the absence of a graphic symbol.
+
+![Diagram showing the structure of the 7-bit coded character set. It is a large rectangle divided into three sections: a vertical column on the left labeled 'C0', a large central area labeled 'G0', and a small box at the top right labeled 'SP'. A small box at the bottom right of the 'G0' area is labeled 'DEL'. The text 'T0811580-93' is located at the bottom right of the diagram.](3121ebddccf183ca63bb9781be440a7e_img.jpg)
+
+T0811580-93
+
+Diagram showing the structure of the 7-bit coded character set. It is a large rectangle divided into three sections: a vertical column on the left labeled 'C0', a large central area labeled 'G0', and a small box at the top right labeled 'SP'. A small box at the bottom right of the 'G0' area is labeled 'DEL'. The text 'T0811580-93' is located at the bottom right of the diagram.
+
+FIGURE 1/T.50  
+**Structure of the 7-bit coded character set**
+
+### 6.4 *Graphic characters*
+
+The 94-bit combinations 2/1 to 7/14 are used for the representation of graphic characters as specified in §§ 6.4.1, 6.4.2 and 6.4.3.
+
+All graphic characters shall be spacing characters, that is, they cause the active position to advance by one character position.
+
+#### 6.4.1 *Unique graphic character allocations*
+
+A unique graphic character is allocated to each of the 82-bit combinations 2/1, 2/2, 2/5 to 3/15, 4/1 to 5/10, 5/15 and 6/1 to 7/10. These characters are specified in Table 1/T.50.
+
+#### 6.4.2 *Alternative graphic character allocations*
+
+Two alternative graphic characters are allocated to each of the bit combinations 2/3 and 2/4. These characters are specified in Table 2/T.50.
+
+TABLE 1/T.50
+
+#### Unique graphic character allocations
+
+| Graphic symbol | Name                   | Coded representation | Graphic symbol | Name                   | Coded representation |
+|----------------|------------------------|----------------------|----------------|------------------------|----------------------|
+| !              | Exclamation mark       | 2/1                  | M              | Latin capital letter M | 4/13                 |
+| “              | Quotation mark         | 2/2                  | N              | Latin capital letter N | 4/14                 |
+| %              | Percent sign           | 2/5                  | O              | Latin capital letter O | 4/15                 |
+| &              | Ampersand              | 2/6                  | P              | Latin capital letter P | 5/0                  |
+| '              | Apostrophe             | 2/7                  | Q              | Latin capital letter Q | 5/1                  |
+| (              | Left parenthesis       | 2/8                  | R              | Latin capital letter R | 5/2                  |
+| )              | Right parenthesis      | 2/9                  | S              | Latin capital letter S | 5/3                  |
+| *              | Asterisk               | 2/10                 | T              | Latin capital letter T | 5/4                  |
+| +              | Plus sign              | 2/11                 | U              | Latin capital letter U | 5/5                  |
+| ,              | Comma                  | 2/12                 | V              | Latin capital letter V | 5/6                  |
+| –              | Hyphen, minus sign     | 2/13                 | W              | Latin capital letter W | 5/7                  |
+| .              | Full stop              | 2/14                 | X              | Latin capital letter X | 5/8                  |
+| /              | Solidus                | 2/15                 | Y              | Latin capital letter Y | 5/9                  |
+| 0              | Digit zero             | 3/0                  | Z              | Latin capital letter Z | 5/10                 |
+| 1              | Digit one              | 3/1                  | –              | Low line, underline    | 5/15                 |
+| 2              | Digit two              | 3/2                  | a              | Latin small letter a   | 6/1                  |
+| 3              | Digit three            | 3/3                  | b              | Latin small letter b   | 6/2                  |
+| 4              | Digit four             | 3/4                  | c              | Latin small letter c   | 6/3                  |
+| 5              | Digit five             | 3/5                  | d              | Latin small letter d   | 6/4                  |
+| 6              | Digit six              | 3/6                  | e              | Latin small letter e   | 6/5                  |
+| 7              | Digit seven            | 3/7                  | f              | Latin small letter f   | 6/6                  |
+| 8              | Digit eight            | 3/8                  | g              | Latin small letter g   | 6/7                  |
+| 9              | Digit nine             | 3/9                  | h              | Latin small letter h   | 6/8                  |
+| :              | Colon                  | 3/10                 | i              | Latin small letter i   | 6/9                  |
+| ;              | Semicolon              | 3/11                 | j              | Latin small letter j   | 6/10                 |
+| <              | Less-than sign         | 3/12                 | k              | Latin small letter k   | 6/11                 |
+| =              | Equals sign            | 3/13                 | l              | Latin small letter l   | 6/12                 |
+| >              | Greater-than sign      | 3/14                 | m              | Latin small letter m   | 6/13                 |
+| ?              | Question mark          | 3/15                 | n              | Latin small letter n   | 6/14                 |
+| A              | Latin capital letter A | 4/1                  | o              | Latin small letter o   | 6/15                 |
+| B              | Latin capital letter B | 4/2                  | p              | Latin small letter p   | 7/0                  |
+| C              | Latin capital letter C | 4/3                  | q              | Latin small letter q   | 7/1                  |
+| D              | Latin capital letter D | 4/4                  | r              | Latin small letter r   | 7/2                  |
+| E              | Latin capital letter E | 4/5                  | s              | Latin small letter s   | 7/3                  |
+| F              | Latin capital letter F | 4/6                  | t              | Latin small letter t   | 7/4                  |
+| G              | Latin capital letter G | 4/7                  | u              | Latin small letter u   | 7/5                  |
+| H              | Latin capital letter H | 4/8                  | v              | Latin small letter v   | 7/6                  |
+| I              | Latin capital letter I | 4/9                  | w              | Latin small letter w   | 7/7                  |
+| J              | Latin capital letter J | 4/10                 | x              | Latin small letter x   | 7/8                  |
+| K              | Latin capital letter K | 4/11                 | y              | Latin small letter y   | 7/9                  |
+| L              | Latin capital letter L | 4/12                 | z              | Latin small letter z   | 7/10                 |
+
+TABLE 2/T.50
+
+#### **Alternative graphic character allocations**
+
+| Graphic symbol | Name          | Coded representation |
+|----------------|---------------|----------------------|
+| £              | Pound sign    | 2/3                  |
+| #              | Number sign   | 2/3                  |
+| \$             | Dollar sign   | 2/4                  |
+| ¤              | Currency sign | 2/4                  |
+
+Either the character POUND SIGN or the character NUMBER SIGN shall be allocated to bit combination 2/3 and either the character DOLLAR SIGN or the character CURRENCY SIGN shall be allocated to bit combination 2/4 (see § 8).
+
+Unless otherwise agreed between sender and recipient, the graphic symbols £, \$, ¤ do not designate the currency of a specific country.
+
+#### 6.4.3 *National or application-oriented graphic character allocations*
+
+No specific graphic character is allocated to the ten bit combinations 4/0, 5/11 to 5/14, 6/0 and 7/11 to 7/14. These bit combinations are available for national or application-oriented use. Either a unique graphic character shall be allocated to each of these bit combinations, or the bit combination shall be declared unused (see § 8.1).
+
+### 6.5 *Character DELETE*
+
+The acronym of the character DELETE is DEL and its coded representation is 7/15. DEL was originally used to erase or obliterate an erroneous or unwanted character in punched tape. DEL may be used for media-fill or time-fill. DEL characters may be inserted into, or removed from, a data stream without affecting the information content of that stream, but such action may affect the information layout and/or the control of equipment.
+
+## 7 **Composite graphic characters**
+
+Whilst all graphic characters specified in this Recommendation are spacing characters, it is possible, by using BACKSPACE or CARRIAGE RETURN to image two or more graphic characters at the same character position (see also § B.2).
+
+For example, SOLIDUS and EQUALS SIGN may be combined to image “not equals”. The character LOW LINE, that may be used as a free-standing character, may also be associated with other character(s) to represent the graphic rendition “underlined”.
+
+Diacritical marks may be allocated to the bit combinations specified in § 6.4.3 and be available for composing accented letters. For such composition a sequence of three characters, the first or last of which is the letter to be accented and the second of which is BACKSPACE may be used. Furthermore, QUOTATION MARK, APOSTROPHE or COMMA can be associated with a letter by means of BACKSPACE for the composition of an accented letter with a diaeresis, an acute accent or a cedilla, respectively.
+
+## 8 Versions of the coded character set
+
+### 8.1 General
+
+The basic code table is shown in Table 4/T.50.
+
+In order to use the 7-bit coded character set for information interchange, it is necessary to exercise the options left open in § 6:
+
+- to specify the C0 set of control characters according to Annex A;
+- to specify the G0 set:
+  - to allocate to each of the bit combinations 2/3 and 2/4 one of the alternative graphic characters specified in § 6.4.2;
+  - to allocate to each of the bit combinations 4/0, 5/11 to 5/14, 6/0 and 7/11 to 7/14 a unique graphic character, or to declare the bit combination unused.
+
+A graphic character allocated to a bit combination specified in §§ 6.4.1 and 6.4.2 shall not be allocated to any other bit combination. For example, the POUND SIGN, if not allocated to bit combination 2/3, shall not be allocated to any other bit combination.
+
+A character set completed in this way is called a “version of T.50”.
+
+### 8.2 International Reference Version (IRV)
+
+This version is available for use when there is no requirement to use a national or an application-oriented version. In information interchange, the IRV is assumed unless an agreement exists between sender and recipient of the data (see also § 10). The graphic characters allocated to the G0 set of the IRV shall be as specified in Tables 1/T.50 and 3/T.50. See Table 5/T.50. Agreement between sender and recipient of the data shall be required if composite characters are used.
+
+The C0 set of the IRV is as specified in Annex A.
+
+TABLE 3/T.50
+
+**IRV graphic character allocations**
+
+| Graphic Symbol | Name                 | Coded representation |
+|----------------|----------------------|----------------------|
+| #              | Number sign          | 2/3                  |
+| \$             | Dollar sign          | 2/4                  |
+| @              | Commercial at        | 4/0                  |
+| [              | Left square bracket  | 5/11                 |
+| \              | Reverse solidus      | 5/12                 |
+| ]              | Right square bracket | 5/13                 |
+| ^              | Circumflex accent    | 5/14                 |
+| ‘              | Grave accent         | 6/0                  |
+| {              | Left curly bracket   | 7/11                 |
+|                | Vertical line        | 7/12                 |
+| }              | Right curly bracket  | 7/13                 |
+| ~              | Tilde                | 7/14                 |
+
+### 8.3 *National versions*
+
+8.3.1 The responsibility for defining national versions lies with the national standardization bodies. These bodies shall exercise the options available and make the required selection (see Annex B).
+
+8.3.2 If so required, more than one national version can be defined within a country. The different versions shall be separately identified. In particular, when alternative graphic characters are required, for a given bit combination, for example 5/12, two different versions shall be identified, even if they differ only by this single character.
+
+8.3.3 If, in a country, there is no special demand for specific graphic characters, it is strongly recommended that the characters of the G0 set of the International Reference Version (IRV) be selected and allocated to the same bit combinations as in the IRV.
+
+However, when graphic characters that are different from the characters of the IRV are required, they shall have distinct forms and be given distinctive names which are not in conflict with any of the forms or the names of any of the graphic characters in the IRV.
+
+### 8.4 *Application-oriented versions*
+
+Within national or international industries, organizations or professional groups, application-oriented versions may be used. They require precise agreement among the interested parties, who will have to exercise the options available and to make the required selection.
+
+## 9 **Identification of versions**
+
+### 9.1 *Purpose and context of identification*
+
+CC-data-elements conforming to a version of this Recommendation are intended to form all or part of a composite unit of coded information that is interchanged between an originator and a recipient. The identification of the version of this Recommendation that has been adopted by the originator shall also be available to the recipient. The route by which such identification is communicated to the recipient is outside the scope of this Recommendation.
+
+However, some standards for interchange of coded information may permit, or require, that the coded representation of the identification applicable to the CC-data-elements forms a part of the interchanged information. This clause specifies a coded representation for the identification of a version of this Recommendation. Such coded representation form all or part of an identifying data element, which may be included in information interchange in accordance with the relevant standard.
+
+## 9.2 *Identification of a version*
+
+The identification of a version of this Recommendation shall comprise a set of identifications, one for the C0 set and G0 set that constitute the version. Each identification in the set shall consist of a designating escape sequence of the type shown below:
+
+- ESC 2/1 F shall identify the C0 set;
+- ESC 2/8 F shall identify the G0 set.
+
+The final byte F of these escape sequence shall be obtained from the International Register ISO 2375. If the C0 set is empty, the identification shall be the same escape sequence in which the Final byte F is 7/14.
+
+The IRV shall be identified by the following escape sequences:
+
+- Registration ISO IR No. 1: ESC 2/1 4/0;
+- Registration ISO IR No. 6: ESC 2/8 4/2.
+
+*Note* – This IRV defers from the previous IRV of IA5.
+
+## 10 Explanation of code Tables 4/T.50 and 5/T.50
+
+Table 4/T.50 is the basic 7-bit code table. It shows the 7-bit coded character set specified in § 5 and indicates the options related to alternative graphic characters (see § 6.4.2) and national or application-oriented use (see § 6.4.3).
+
+Positions 0/0 to 1/15 reserved for control characters are shown empty. Positions 2/0 to 7/15 contain a graphic symbol, an acronym, or a reference to a section of this Recommendation. A reference to §§ 6.4.2 and 6.4.3 is denoted by 1 or 2 respectively.
+
+Table 5/T.50 is a code table showing a version which includes the G0 set of the IRV and no C0 set.
+
+TABLE 4/T.50
+
+Basic code table
+
+|                |                |                |                |    | b <sub>7</sub> | 0 | 0 | 0  | 0 | 1 | 1 | 1 | 1   |
+|----------------|----------------|----------------|----------------|----|----------------|---|---|----|---|---|---|---|-----|
+|                |                |                |                |    | b <sub>6</sub> | 0 | 0 | 1  | 1 | 0 | 0 | 1 | 1   |
+|                |                |                |                |    | b <sub>5</sub> | 0 | 1 | 0  | 1 | 0 | 1 | 0 | 1   |
+|                |                |                |                |    |                | 0 | 1 | 2  | 3 | 4 | 5 | 6 | 7   |
+| b <sub>4</sub> | b <sub>3</sub> | b <sub>2</sub> | b <sub>1</sub> |    |                |   |   |    |   |   |   |   |     |
+| 0              | 0              | 0              | 0              | 0  |                |   |   | SP | 0 | ② | P | ② | p   |
+| 0              | 0              | 0              | 1              | 1  |                |   |   | !  | 1 | A | Q | a | q   |
+| 0              | 0              | 1              | 0              | 2  |                |   |   | "  | 2 | B | R | b | r   |
+| 0              | 0              | 1              | 1              | 3  |                |   |   | £  | 3 | C | S | c | s   |
+| 0              | 1              | 0              | 0              | 4  |                |   |   | \$ | 4 | D | T | d | t   |
+| 0              | 1              | 0              | 1              | 5  |                |   |   | %  | 5 | E | U | e | u   |
+| 0              | 1              | 1              | 0              | 6  |                |   |   | &  | 6 | F | V | f | v   |
+| 0              | 1              | 1              | 1              | 7  |                |   |   | '  | 7 | G | W | g | w   |
+| 1              | 0              | 0              | 0              | 8  |                |   |   | (  | 8 | H | X | h | x   |
+| 1              | 0              | 0              | 1              | 9  |                |   |   | )  | 9 | I | Y | i | y   |
+| 1              | 0              | 1              | 0              | 10 |                |   |   | *  | : | J | Z | j | z   |
+| 1              | 0              | 1              | 1              | 11 |                |   |   | +  | ; | K | ② | k | ②   |
+| 1              | 1              | 0              | 0              | 12 |                |   |   | ,  | < | L | ② | l | ②   |
+| 1              | 1              | 0              | 1              | 13 |                |   |   | —  | = | M | ② | m | ②   |
+| 1              | 1              | 1              | 0              | 14 |                |   |   | .  | > | N | ② | n | ②   |
+| 1              | 1              | 1              | 1              | 15 |                |   |   | /  | ? | O | _ | o | DEL |
+
+C0 set
+
+T0811590-93
+
+TABLE 5/T.50  
+Version with the G0 set of the IRV
+
+|                |                |                |                |    | b <sub>7</sub> | 0 | 0 | 0  | 0 | 1 | 1 | 1 | 1   |
+|----------------|----------------|----------------|----------------|----|----------------|---|---|----|---|---|---|---|-----|
+|                |                |                |                |    | b <sub>6</sub> | 0 | 0 | 1  | 1 | 0 | 0 | 1 | 1   |
+|                |                |                |                |    | b <sub>5</sub> | 0 | 1 | 0  | 1 | 0 | 1 | 0 | 1   |
+|                |                |                |                |    |                | 0 | 1 | 2  | 3 | 4 | 5 | 6 | 7   |
+| b <sub>4</sub> | b <sub>3</sub> | b <sub>2</sub> | b <sub>1</sub> |    |                |   |   |    |   |   |   |   |     |
+| 0              | 0              | 0              | 0              | 0  |                |   |   | SP | 0 | @ | P | ` | p   |
+| 0              | 0              | 0              | 1              | 1  |                |   |   | !  | 1 | A | Q | a | q   |
+| 0              | 0              | 1              | 0              | 2  |                |   |   | "  | 2 | B | R | b | r   |
+| 0              | 0              | 1              | 1              | 3  |                |   |   | #  | 3 | C | S | c | s   |
+| 0              | 1              | 0              | 0              | 4  |                |   |   | \$ | 4 | D | T | d | t   |
+| 0              | 1              | 0              | 1              | 5  |                |   |   | %  | 5 | E | U | e | u   |
+| 0              | 1              | 1              | 0              | 6  |                |   |   | &  | 6 | F | V | f | v   |
+| 0              | 1              | 1              | 1              | 7  |                |   |   | '  | 7 | G | W | g | w   |
+| 1              | 0              | 0              | 0              | 8  |                |   |   | (  | 8 | H | X | h | x   |
+| 1              | 0              | 0              | 1              | 9  |                |   |   | )  | 9 | I | Y | i | y   |
+| 1              | 0              | 1              | 0              | 10 |                |   |   | *  | : | J | Z | j | z   |
+| 1              | 0              | 1              | 1              | 11 |                |   |   | +  | ; | K | [ | k | {   |
+| 1              | 1              | 0              | 0              | 12 |                |   |   | ,  | < | L | \ | l |     |
+| 1              | 1              | 0              | 1              | 13 |                |   |   | —  | = | M | ] | m | }   |
+| 1              | 1              | 1              | 0              | 14 |                |   |   | .  | > | N | ^ | n | ~   |
+| 1              | 1              | 1              | 1              | 15 |                |   |   | /  | ? | O | _ | o | DEL |
+
+T0811600-93
+
+# ANNEX A (to Recommendation T.50) (Normative)
+
+## **Specification of the C0 set**
+
+### A.1 *Definition of control set*
+
+Table A-1/T.50 shows the C0 set.
+
+The control characters are listed below in the alphabetical order of their acronyms.
+
+#### A.1.1 **ACK acknowledge**
+
+A transmission control character transmitted by a receiver as an affirmative response to the sender.
+
+#### A.1.2 **BEL bell**
+
+A control character that is used when there is a need to call for attention; it may control alarm or attention devices.
+
+#### A.1.3 **BS backspace**
+
+A format effector which causes the active position to move one character position in the direction opposite to the transmission of one or more texts.
+
+#### A.1.4 **CAN cancel**
+
+A character, or the first character of a sequence, indicating that the data preceding it is in error. As a result, this data shall be ignored. The specific meaning of this character shall be defined for each application and/or between sender and recipient.
+
+#### A.1.5 **CR carriage return**
+
+A format effector which causes the active position to move to the line home position on the same line.
+
+#### A.1.6 **DC1 device control one**
+
+A device control character which is primarily intended for turning on or starting an ancillary device. If it is not required for this purpose, it may be used to restore a device to the basic mode of operation (see also DC2 and DC3), or for any other device control function not provided by other DCs. When used for data flow control, DC1 is sometimes called “X-ON”.
+
+#### A.1.7 **DC2 device control two**
+
+A device control character which is primarily intended for turning on or starting an ancillary device. If it is not required for this purpose, it may be used to set a device to a special mode of operation (in which case DC1 is used to restore the device to the basic mode), or for any other device control function not provided by other DCs.
+
+#### **A.1.8 DC3 device control three**
+
+A device control character which is primarily intended for turning off or stopping an ancillary device. This function may be a secondary level stop, for example wait, pause, stand-by or halt (in which case DC1 is used to restore normal operation). If it is not required for this purpose, it may be used for any other ancillary device control function not provided by other DCs. When used for data flow control, DC3 is sometimes called “X-OFF”.
+
+#### **A.1.9 DC4 device control four**
+
+A device control character which is primarily intended for turning off, stopping or interrupting an ancillary device. If it is not required for this purpose, it may be used for any other device control function not provided by other DCs.
+
+#### **A.1.10 DEL delete**
+
+A character used primarily to erase or obliterate an erroneous or unwanted character in punched tape. DEL characters may also serve to accomplish media-fill or time-fill. They may be inserted into, or removed from, a stream of data without affecting the information content of that stream, but such action may affect the information layout and/or the control of equipment.
+
+#### **A.1.11 DLE data link escape**
+
+A transmission control character which will change the meaning of a limited number of contiguously following bit combinations. It is used exclusively to provide supplementary transmission control functions. Only graphic characters and transmission control characters can be used in DLE sequences.
+
+#### **A.1.12 EM end of medium**
+
+A control character that may be used to identify the physical end of a medium, or the end of the used portion of a medium, or the end of the wanted portion of data recorded on a medium.
+
+#### **A.1.13 ENQ enquiry**
+
+A transmission control character used as a request for a response from a remote station – the response may include station identification and/or station status. When a “Who are you” function is required on the general switched transmission network the first use of ENQ after the connection is established shall have the meaning “Who are you” (station identification). Subsequent use of ENQ may, or may not, include the function “Who are you”, as determined by agreement.
+
+#### **A.1.14 EOT end of transmission**
+
+A transmission control character used to indicate the conclusion of the transmission of one or more text.
+
+#### **A.1.15 ESC escape**
+
+A control character which is used for code extension purposes. It causes the meanings of a limited number of bit combinations following it in the data stream to be changed. The use of ESC is defined in ISO 2022.
+
+#### **A.1.16 ETB end of transmission block**
+
+A transmission control character used to indicate the end of a transmission block of data where data is divided into such blocks for transmission purposes.
+
+#### **A.1.17 ETX end of text**
+
+A transmission control character which indicates the end of a text.
+
+#### **A.1.18 FF form feed**
+
+A format effector which causes the active position to advance to the corresponding character position on a pre-determined line of the next form or page.
+
+#### **A.1.19 HT horizontal tabulation**
+
+A format effector which causes the active position to advance to the next pre-determined character position.
+
+#### **A.1.20 IS1 (US) information separator one (Unit separator)**
+
+A control character used to separate and qualify data logically; its specific meaning has to be defined for each application. If this character is used in hierarchical order as specified in the general definition of IS, it delimits a data item called a unit.
+
+#### **A.1.21 IS2 (RS) information separator two (Record separator)**
+
+A control character used to separate and qualify data logically; its specific meaning has to be defined for each application. If this character is used in hierarchical order as specified in the general definition of IS, it delimits a data item called a record.
+
+#### **A.1.22 IS3 (GS) information separator three (Group separator)**
+
+A control character used to separate and qualify data logically; its specific meaning has to be defined for each application. If this character is used in hierarchical order as specified in the general definition of IS, it delimits a data item called a group.
+
+#### **A.1.23 IS4 (FS) information separator four (File separator)**
+
+A control character used to separate and qualify data logically; its specific meaning has to be defined for each application. If this character is used in hierarchical order as specified in the general definition of IS, it delimits a data item called a file.
+
+#### **A.1.24 LF line feed**
+
+A format effector which causes the active position to advance to the corresponding character position of the next line.
+
+#### **A.1.25 NAK negative acknowledge**
+
+A transmission control character transmitted by a receiver as a negative response to the sender.
+
+#### **A.1.26 NUL null**
+
+A control character used to accomplish media-fill or time-fill. NUL characters may be inserted into, or removed from, a stream of data without affecting the information content of that stream, but such action may affect the information layout and/or the control of equipment.
+
+#### **A.1.27 SI shift-in**
+
+A control character which is used for code extension purposes. It causes the meanings of the bit combinations following it in the data stream to be changed. The use of SI is defined in ISO 2022.
+
+#### **A.1.28 SO shift-out**
+
+A control character which is used for code extension purposes. It causes the meanings of the bit combinations following it in the data stream to be changed. The use of SO is defined in ISO 2022.
+
+#### **A.1.29 SOH start of heading**
+
+A transmission control character used as the first character of a heading of an information message.
+
+#### **A.1.30 STX start of text**
+
+A transmission control character which is used to indicate the beginning of a text and the end of a heading.
+
+#### **A.1.31 SUB substitute character**
+
+A control character used in the place of a character that has been found to be invalid or in error. SUB is intended to be introduced by automatic means.
+
+#### **A.1.32 SYN synchronous idle**
+
+A transmission control character used by a synchronous transmission system in the absence of any other character (idle condition) to provide a signal from which synchronism may be achieved or retained between data terminal equipment.
+
+#### **A.1.33 VT vertical tabulation**
+
+A format effector which causes the active position to advance to the corresponding character position on the next pre-determined line.
+
+### **A.2 *C0 set of a version of Recommendation T.50***
+
+The C0 set of a version of this Recommendation shall be a subset of the C0 set defined in § A.1. Code positions corresponding to control functions not selected shall be declared unused.
+
+### **A.3 *C0 set of the International Reference Version (IRV)***
+
+The C0 set of the International Reference Version (IRV) is as shown in Table A-1/T.50
+
+TABLE A-1/T.50  
+C0 set of the IRV
+
+|                |                |                |                |    |                |     |   |
+|----------------|----------------|----------------|----------------|----|----------------|-----|---|
+|                |                |                |                |    | b <sub>7</sub> | 0   | 0 |
+|                |                |                |                |    | b <sub>6</sub> | 0   | 0 |
+|                |                |                |                |    | b <sub>5</sub> | 0   | 1 |
+|                |                |                |                |    |                | 0   | 1 |
+| b <sub>4</sub> | b <sub>3</sub> | b <sub>2</sub> | b <sub>1</sub> |    |                |     |   |
+| 0              | 0              | 0              | 0              | 0  | NUL            | DLE |   |
+| 0              | 0              | 0              | 1              | 1  | SOH            | DC1 |   |
+| 0              | 0              | 1              | 0              | 2  | STX            | DC2 |   |
+| 0              | 0              | 1              | 1              | 3  | ETX            | DC3 |   |
+| 0              | 1              | 0              | 0              | 4  | EOT            | DC4 |   |
+| 0              | 1              | 0              | 1              | 5  | ENQ            | NAK |   |
+| 0              | 1              | 1              | 0              | 6  | ACK            | SYN |   |
+| 0              | 1              | 1              | 1              | 7  | BEL            | ETB |   |
+| 1              | 0              | 0              | 0              | 8  | BS             | CAN |   |
+| 1              | 0              | 0              | 1              | 9  | HT             | EM  |   |
+| 1              | 0              | 1              | 0              | 10 | LF             | SUB |   |
+| 1              | 0              | 1              | 1              | 11 | VT             | ESC |   |
+| 1              | 1              | 0              | 0              | 12 | FF             | IS4 |   |
+| 1              | 1              | 0              | 1              | 13 | CR             | IS3 |   |
+| 1              | 1              | 1              | 0              | 14 | SO             | IS2 |   |
+| 1              | 1              | 1              | 1              | 15 | SI             | IS1 |   |
+
+T0811610-93
+
+# ANNEX B
+
+(to Recommendation T.50)
+
+(Informative)
+
+## **Guidelines for standards derived from Recommendation T.50**
+
+### B.1 *General*
+
+When drafting national or application-oriented standards based on this Recommendation, it is recommended that the following considerations be taken into account.
+
+### B.2 *Structure of a standard*
+
+It is recommended that the same structure and editorial style as implemented for this Recommendation be adopted. All facilities, restrictions and specifications of the standard should be stated clearly in sentences using plain language, rather than being summarized in tables with notes.
+
+#### B.2.1 *Control functions*
+
+The standard should contain the selection of control characters from the C0 set and an explicit description of the corresponding control functions. Even where the descriptions are identical with those of this Recommendation, they should be stated explicitly, and not merely by reference to this Recommendation. For application-oriented standards the specific meaning of the Information Separators and of the Device Controls should be defined.
+
+#### B.2.2 *Graphic characters (see § 8.3.3)*
+
+Where there is no need for particular characters, the graphic characters of the International Reference Version (IRV) should be allocated to the same positions and with the same names as in this Recommendation.
+
+#### B.2.3 *Composite graphic characters and repertoire*
+
+This Recommendation permits the construction of composite graphic characters by using the control characters BACKSPACE and CARRIAGE RETURN to image two or more graphic characters at the same character position.
+
+The total number of graphic characters which can be obtained from any version of the character set, with or without using this facility, is called the repertoire. This Recommendation does not define a particular repertoire. However, as the interpretation and/or the imaging of composite characters may cause difficulties, agreement between sender and recipient of the data may be required. To minimize the need for such agreements and to facilitate interchange, national or application-oriented standards may specify a standard repertoire of graphic characters which permit only a limited number of composite graphic characters. Such limitations are considered fully compatible with this Recommendation.
+
+#### B.2.4 *Versions*
+
+In a standard, one or more versions can be specified. It should be noted that a version is not a standard but only part of a standard. The standard itself consists of the C0 set and the well-defined version or versions and a set of clauses as mentioned above. The definition of a version requires that the options mentioned in § 8.1 be properly exercised.
+
+## ANNEX C (to Recommendation T.50)
+
+## **Alphabetical list of abbreviations used in this Recommendation**
+
+|     |                                  |
+|-----|----------------------------------|
+| ACK | Acknowledge                      |
+| BEL | Bell                             |
+| BS  | Backspace                        |
+| CAN | Cancel                           |
+| CR  | Carriage return                  |
+| DC1 | Device control one               |
+| DC2 | Device control two               |
+| DC3 | Device control three             |
+| DC4 | Device control four              |
+| DEL | DELETE                           |
+| DEL | Delete                           |
+| DLE | Data link escape                 |
+| EM  | End of medium                    |
+| ENQ | Enquiry                          |
+| EOT | End of transmission              |
+| ESC | Escape                           |
+| ETB | End of transmission block        |
+| ETX | End of text                      |
+| FF  | Form feed                        |
+| FS  | File separator                   |
+| GS  | Group separator                  |
+| HT  | Horizontal tabulation            |
+| IA5 | International Alphabet No. 5     |
+| IRA | International reference alphabet |
+| IRV | International reference version  |
+| IS1 | Information separator one        |
+| IS2 | Information separator two        |
+| IS3 | Information separator three      |
+| IS4 | Information separator four       |
+| LF  | Line feed                        |
+| NAK | Negative acknowledge             |
+
+|     |                      |
+|-----|----------------------|
+| NUL | Null                 |
+| RS  | Record separator     |
+| SI  | Shift-in             |
+| SO  | Shift-out            |
+| SOH | Start of heading     |
+| SP  | SPACE                |
+| STX | Start of text        |
+| SUB | Substitute character |
+| SYN | Synchronous idle     |
+| US  | Unit separator       |
+| VT  | Vertical tabulation  |
\ No newline at end of file
diff --git a/marked/T/T-REC-T.503-200002-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/T/T-REC-T.503-200002-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..76f2f80db9288df93a4c995e120668752f79e06a
--- /dev/null
+++ b/marked/T/T-REC-T.503-200002-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:ca159653a608f10fdf9ccfd8d3e1a442a4c68f0990313cb76b3c5175336ca352
+size 8349
diff --git a/marked/T/T-REC-T.503-200002-I_PDF-E/5445597cceefaca1ac89e710fe339325_img.jpg b/marked/T/T-REC-T.503-200002-I_PDF-E/5445597cceefaca1ac89e710fe339325_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..67870c7a72430bd5e7b96df95743562831cf2f4c
--- /dev/null
+++ b/marked/T/T-REC-T.503-200002-I_PDF-E/5445597cceefaca1ac89e710fe339325_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:1b0d8c2705cd8bd900deb07ff345bb487ab72819913be7982aab41f4276846bc
+size 9804
diff --git a/marked/T/T-REC-T.503-200002-I_PDF-E/raw.md b/marked/T/T-REC-T.503-200002-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..35da52c7837df9c9b245d5e4f0e008c006c81105
--- /dev/null
+++ b/marked/T/T-REC-T.503-200002-I_PDF-E/raw.md
@@ -0,0 +1,1724 @@
+
+
+![ITU logo: a globe with the letters ITU inside, crossed by a lightning bolt.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg)
+
+ITU logo: a globe with the letters ITU inside, crossed by a lightning bolt.
+
+INTERNATIONAL TELECOMMUNICATION UNION
+
+# ITU-T
+
+TELECOMMUNICATION  
+STANDARDIZATION SECTOR  
+OF ITU
+
+# T.503
+
+(02/2000)
+
+SERIES T: TERMINALS FOR TELEMATIC SERVICES
+
+---
+
+# **Document application profile for the interchange of Group 4 facsimile documents**
+
+ITU-T Recommendation T.503
+
+(Previously CCITT Recommendation)
+
+---
+
+## ITU-T T-SERIES RECOMMENDATIONS **TERMINALS FOR TELEMATIC SERVICES**
+
+*For further details, please refer to ITU-T List of Recommendations.*
+
+# **DOCUMENT APPLICATION PROFILE FOR THE INTERCHANGE OF GROUP 4 FACSIMILE DOCUMENTS**
+
+## **Summary**
+
+This Recommendation defines a document application profile that may be used by any telematic service. Its purpose is to specify an interchange format suitable for the interchange of Group 4 facsimile documents that contain only raster graphics. Documents are interchanged in a formatted form, which enables the recipient to display or print the document as intended by the originator.
+
+## **Source**
+
+ITU-T Recommendation T.503 is being republished in its entirety to include five amendments and one corrigendum previously approved. The last amendment, Amendment 5, was prepared by ITU-T Study Group 8 (1997-2000) and was approved under the WTSC Resolution 1 procedure on 10 February 2000.
+
+## FOREWORD
+
+The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis.
+
+The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics.
+
+The approval of ITU-T Recommendations is covered by the procedure laid down in WTSC Resolution 1.
+
+In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC.
+
+## NOTE
+
+In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+## INTELLECTUAL PROPERTY RIGHTS
+
+ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process.
+
+As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementors are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database.
+
+© ITU 2001
+
+All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from ITU.
+
+# CONTENTS
+
+|         |                                                                                     | <i>Page</i> |
+|---------|-------------------------------------------------------------------------------------|-------------|
+| 1       | Scope .....                                                                         | 1           |
+| 2       | Field of application .....                                                          | 1           |
+| 3       | References .....                                                                    | 1           |
+| 4       | Definitions .....                                                                   | 2           |
+| 5       | Characteristics supported by this document application profile .....                | 2           |
+| 5.1     | Overview .....                                                                      | 2           |
+| 5.2     | Logical characteristics .....                                                       | 2           |
+| 5.3     | Layout characteristics .....                                                        | 2           |
+| 5.4     | Content characteristics .....                                                       | 2           |
+| 6       | Definition of the document application profile .....                                | 3           |
+| 6.1     | Overview .....                                                                      | 3           |
+| 6.2     | Definition of document structure .....                                              | 3           |
+| 6.3     | Definition of attribute values .....                                                | 4           |
+| 6.4     | Content architectures .....                                                         | 6           |
+| Annex A | Format of the values of the attributes "object identifier" .....                    | 7           |
+| Annex B | Extension for continuous-tone colour and gray-scale image documents .....           | 7           |
+| B.1     | Introduction .....                                                                  | 7           |
+| B.2     | References .....                                                                    | 7           |
+| B.3     | Definitions .....                                                                   | 8           |
+| B.4     | Characteristics supported by this document application profile .....                | 8           |
+| B.5     | Definition of the document application profile .....                                | 9           |
+| B.6     | Definition of the document application profile for soft-copy communication .....    | 10          |
+| B.7     | Preferred Huffman tables for T.81 encoding .....                                    | 10          |
+| B.8     | JPEG data structure on continuous-tone image .....                                  | 10          |
+| B.9     | ASN.1 definition for this annex .....                                               | 16          |
+| Annex C | Extension for colour and gray-scale image documents using Recommendation T.43 ..... | 22          |
+| C.1     | Introduction .....                                                                  | 22          |
+| C.2     | References .....                                                                    | 22          |
+| C.3     | Definitions .....                                                                   | 22          |
+| C.4     | Characteristics supported by this document application profile .....                | 22          |
+| C.5     | Definition of the document application profile .....                                | 23          |
+| C.6     | Definition of the document application profile for soft-copy communication .....    | 26          |
+| C.7     | ASN.1 definition for this annex .....                                               | 26          |
+
+
+
+# DOCUMENT APPLICATION PROFILE FOR THE INTERCHANGE OF GROUP 4 FACSIMILE DOCUMENTS
+
+# 1 Scope
+
+**1.1** This Recommendation defines a document application profile conforming to the T.410 series of Recommendations.
+
+Its purpose is to specify an interchange format suitable for the interchange of Group 4 facsimile documents that contain only raster graphics.
+
+Documents are interchanged in a formatted form, which enables the recipient to display or print the document as intended by the originator.
+
+**1.2** This Recommendation, together with designated parts of T.563, defines a document application profile that may be used by any telematic service.
+
+# 2 Field of application
+
+**2.1** This Recommendation defines a document application profile that is in conformance with the T.410 series of Recommendations and that allows Group 4 facsimile documents to be interchanged only in a formatted form, which allows a recipient to reproduce the document as intended by the originator.
+
+**2.2** This document application profile is designed to be independent of the means used to create or to interchange the encoded documents.
+
+**2.3** The features which can be interchanged using this document application profile fall into the following categories:
+
+- a) Page format features – these concern how the layout of each page of a document will appear when reproduced;
+- b) Raster-graphics layout and imaging features – these concern how the document content will appear within the pages of the reproduced document;
+- c) Raster-graphics coding – these concern the raster graphics representations and control functions that make up the document raster-graphics content.
+
+**2.4** It is assumed that, when negotiation is performed by the service using this document application profile, all non-basic features are subject to negotiation.
+
+# 3 References
+
+The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; all users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published.
+
+- ITU-T Recommendation T.6 (1988), *Facsimile coding schemes and coding control functions for Group 4 facsimile apparatus*.
+- ITU-T T.410 series of Recommendations, *Open Document Architecture (ODA) and interchange format*.
+- ITU-T Recommendation T.417 (1993) | ISO/IEC 8613-7:1994, *Information technology – Open document architecture (ODA) and interchange format: Raster graphics content architecture*.
+- ITU-T Recommendation T.563 (1996), *Terminal characteristics for Group 4 facsimile apparatus*.
+- ITU-T Recommendation X.680 (1997) | ISO/IEC 8824-1:1998, *Information technology – Abstract Syntax Notation One (ASN. 1): Specification of basic notation*.
+- ITU-T Recommendation X.681 (1997) | ISO/IEC 8824-2:1998, *Information technology – Abstract Syntax Notation One (ASN. 1): Information object specification*.
+
+- ITU-T Recommendation X.682 (1997) | ISO/IEC 8824-3:1998, *Information technology – Abstract Syntax Notation One (ASN. 1): Constraint specification*.
+- ITU-T Recommendation X.683 (1997) | ISO/IEC 8824-4:1998, *Information technology – Abstract Syntax Notation One (ASN. 1): Parameterization of ASN. 1 specifications*.
+- ITU-T Recommendation X.690 (1997) | ISO/IEC 8825-1:1998, *Information technology – ASN. 1 encoding rules – Specification of Basic Encoding Rules (BER), Canonical Encoding Rules (CER) and Distinguished Encoding Rules (DER)*.
+
+# 4 Definitions
+
+The definitions in Recommendation T.411 apply to this Recommendation.
+
+# 5 Characteristics supported by this document application profile
+
+## 5.1 Overview
+
+A Group 4 facsimile document is the result of a formatting process and therefore the purpose of this document application profile is to allow transfer of the complete layout of the document.
+
+Only one category of content is allowed within the same page, namely: *raster graphics content* (per ITU-T Recommendation T.417) as used by facsimile Group 4 apparatus.
+
+This section specifies the functional description of the features supported by this document application profile.
+
+## 5.2 Logical characteristics
+
+Not applicable.
+
+## 5.3 Layout characteristics
+
+### 5.3.1 Layout document structure
+
+A document is seen as a succession of pages.
+
+The content of a page is: *raster graphics content* architecture.
+
+### 5.3.2 Document structure elements
+
+#### 5.3.2.1 Page format
+
+**5.3.2.1.1** The document is imaged in a text area which must be within the assured reproduction area.
+
+**5.3.2.1.2** The dimensions of the assured reproduction area depend on the paper used.
+
+**5.3.2.1.3** The possible paper formats are defined in Recommendation T.563.
+
+**5.3.2.1.4** Only the vertical orientation of the page is permitted.
+
+#### 5.3.2.2 Block
+
+Not applicable (the content is directly related to the page).
+
+## 5.4 Content characteristics
+
+The Group 4 facsimile document contains raster graphics in facsimile Group 4 format.
+
+### 5.4.1 Raster-graphics content
+
+#### 5.4.1.1 Raster-graphics imaging
+
+The content of raster-graphics is defined by the dimensions of the page and the number of pels per line, in accordance with Table 2/T.563.
+
+#### **5.4.1.2 Pel spacing, line spacing and pel transmission density**
+
+This property defines the distance between successive pels on a line and between successive lines of pels.
+
+The basic value is 6 BMU, corresponding to 200 pels per 25.4 mm. It is also the default value.
+
+The non-basic values are 1, 2, 3, 4 and 5 BMU, respectively corresponding to 1200, 600, 400, 300 and 240 pels per 25.4 mm.
+
+### **5.4.2 Received document**
+
+This document application profile, being limited to formatted form, does not support any features to facilitate processing of an interchanged document by a receiver.
+
+# **6 Definition of the document application profile**
+
+## **6.1 Overview**
+
+### **6.1.1 Document architecture level**
+
+This document profile makes use of document architecture class FDA, as defined in Recommendation T.412. A document according to this document architecture profile includes a specific layout structure only.
+
+The document architecture level is defined in Tables 2, 3 and 4.
+
+The specific layout structure is always present in any document conforming to this document application profile.
+
+### **6.1.2 Content architecture level**
+
+The content architecture level that may be used in documents conforming to this document application profile is as follows: *raster graphics formatted content architecture level*, defined in Tables 5 and 6.
+
+The coding method to be used is that defined by Recommendation T.6. In addition, any non-basic features defined in Recommendation T.6 may be used, provided that they are indicated in the document profile.
+
+### **6.1.3 Document profile level**
+
+The document profile level used in this document application profile is defined in Table 1. Every document interchanged in accordance with this document application profile must include a document profile. Every non-basic attribute value used in a document must be indicated in the document profile.
+
+### **6.1.4 Interchange format class**
+
+The interchange format class used in this document application profile is "B", as defined in Recommendation T.415.
+
+## **6.2 Definition of document structure**
+
+### **6.2.1 Specific layout structure**
+
+The number of hierarchical levels is 2, namely:
+
+- document layout root;
+- page.
+
+The document layout root and page levels are mandatory. Only one content portion must be associated with each page.
+
+### **6.2.2 Generic layout structure**
+
+Not applicable.
+
+## 6.3 Definition of attribute values
+
+The attributes applicable to layout components are defined in Table 2. The following notation is used in this table:
+
+- attribute not applicable to object description
+- m mandatory attribute
+- nm non-mandatory attribute
+- d defaultable attribute
+
+Capital letters (M, NM and D) are used for groups of attributes. The allowable attribute values for object descriptions are defined in Table 3.
+
+**Table 1/T.503 – Document profile attributes**
+
+| Attribute                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       | Value | Permissible values                                                                                                                                                                                                                                                                                                                                                                                           |
+|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Document profile descriptor                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     | M     | Present                                                                                                                                                                                                                                                                                                                                                                                                      |
+| Specific layout structure                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       | m     |                                                                                                                                                                                                                                                                                                                                                                                                              |
+| Document characteristics                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        | M     |                                                                                                                                                                                                                                                                                                                                                                                                              |
+| Document Application Profile                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    | m     |                                                                                                                                                                                                                                                                                                                                                                                                              |
+| Document architecture class                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     | m     |                                                                                                                                                                                                                                                                                                                                                                                                              |
+| No basic document charact.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      | NM    |                                                                                                                                                                                                                                                                                                                                                                                                              |
+| Page dimensions<br>(Note 1)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     | nm    |                                                                                                                                                                                                                                                                                                                                                                                                              |
+| Type of coding                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  | nm    |                                                                                                                                                                                                                                                                                                                                                                                                              |
+| Raster graphics coding attributes                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               | NM    |                                                                                                                                                                                                                                                                                                                                                                                                              |
+| Compression                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     | nm    |                                                                                                                                                                                                                                                                                                                                                                                                              |
+| Raster graphics presentation features                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           | NM    |                                                                                                                                                                                                                                                                                                                                                                                                              |
+| Pel transmission density                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        | nm    |                                                                                                                                                                                                                                                                                                                                                                                                              |
+|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |       | North American letter = (10 200, 13 200 fixed or variable)<br>ISO B4 = (11 811, 16 677 fixed or variable)<br>ISO B3 = (14 030, 19 840 fixed or variable)<br>Japanese legal = (12 141, 17 196 fixed or variable)<br>Japanese letter = (8598, 12 141 fixed or variable)<br>North American legal = (10 200, 16 800 fixed or variable)<br>North American ledger = (13 200, 20 400 fixed or variable)<br>(Note 2) |
+|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |       | T.85 single-progression<br>(Note 3)                                                                                                                                                                                                                                                                                                                                                                          |
+|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |       | Uncompressed                                                                                                                                                                                                                                                                                                                                                                                                 |
+|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |       | 5 BMU (240 pels/25.4 mm)<br>4 BMU (300 pels/25.4 mm)<br>3 BMU (400 pels/25.4 mm)<br>2 BMU (600 pels/25.4 mm)<br>1 BMU (1200 pels/25.4 mm)                                                                                                                                                                                                                                                                    |
+| NOTE 1 – This dimension attribute is represented as a data element which consists of two integers.<br>Two integers specify width and height of a page in basic measurement units (BMUs).<br>NOTE 2 – An indefinite page length is represented by a variable measure in the vertical dimension. The value of this data is then arbitrary and should be the nominal page length.<br>NOTE 3 – If basic Lo is supported, object ID {0020850} shall be indicated.<br>If optional Lo is supported, object ID {0020851} shall be indicated. When object ID {0020851} is indicated, object ID {0020850} shall also be indicated.<br>This is the coding scheme defined in clause 4/T.85. |       |                                                                                                                                                                                                                                                                                                                                                                                                              |
+
+**Table 2/T.503 – Attributes applicable to layout components**
+
+| Attribute                | Document layout root | Page |
+|--------------------------|----------------------|------|
+| <i>Shared attributes</i> |                      |      |
+| Object type              | m                    | m    |
+| Object identifier        | nm                   | nm   |
+| Subordinate              | nm                   | –    |
+| Content portions         | –                    | nm   |
+| Default value lists      | nm                   | –    |
+| <i>Layout attributes</i> |                      |      |
+| Presentation attributes  | –                    | d    |
+| Dimensions               | –                    | d    |
+
+**Table 3/T.503 – Attribute values for layout object descriptions**
+
+| Attribute                | Basic value                                 | Default value                  | Non-basic value                                                                                                                                                                                  |
+|--------------------------|---------------------------------------------|--------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| <i>Shared attributes</i> |                                             |                                |                                                                                                                                                                                                  |
+| Object type              | Document layout root, page                  | None                           | None                                                                                                                                                                                             |
+| Object identifier        | As defined in Rec. T.412 (see also Annex A) | None                           | None                                                                                                                                                                                             |
+| Subordinate              | As defined in Rec. T.412                    | None                           | None                                                                                                                                                                                             |
+| Content portions         | As defined in Rec. T.412                    | None                           | None                                                                                                                                                                                             |
+| Default value lists      | See Table 4                                 | None                           | None                                                                                                                                                                                             |
+| <i>Layout attributes</i> |                                             |                                |                                                                                                                                                                                                  |
+| Presentation attributes  | See Table 5                                 |                                |                                                                                                                                                                                                  |
+| Dimensions<br>(Note 1)   | Horizontal = 9920 BMU                       | Horizontal = 9920 BMU          | North American letter = (10 200, 13 200)<br>ISO B4 = (11 811, 16 677)                                                                                                                            |
+|                          | Vertical = 14 030 BMU (Note 2)              | Vertical = 14 030 BMU (Note 3) | ISO A3 = (1430, 19 840)<br>Japanese legal = (12 141, 17 196)<br>Japanese letter = (8598, 12 141)<br>North American legal = (10 200, 16 800)<br>North American ledger = (13 200, 20 400) (Note 2) |
+
+NOTE 1 – This dimension attribute is represented as a date element which consists of two integers. Two integers specify width and height of a page in basic measurement units (BMUs).
+
+NOTE 2 – Width is indicated by fixed measure, and at the same time height is indicated by either fixed or variable measure.
+
+The use of variable measure for height indication depends on each application, for example, real time scanning, fixed printing paper, etc. Therefore, for example, when a transmitting terminal requests to use variable measure for height indication, a receiving terminal will accept variable measure for height indication even though the receiving terminal adopts cut sheet paper (fixed size paper) for printing.
+
+NOTE 3 – Both width and height are indicated by fixed measures.
+
+**Table 4/T.503 – Defaultable attributes that may be specified  
+in a default value list of the document layout root**
+
+| Object type | Defaultable attributes<br>that can be specified |
+|-------------|-------------------------------------------------|
+| Page        | Presentation attributes<br>Dimensions           |
+
+## 6.4 Content architectures
+
+The following raster graphics content architecture level is used in this document application profile.
+
+### 6.4.1 Raster graphics content architecture level
+
+The type of coding to be used is as defined in Recommendation T.6.
+
+The code extension control function may be used, provided its use is agreed by prior negotiation and is indicated in the document profile. This control function is used to invoke uncompressed mode of coding.
+
+The presentation attributes that may be used are defined in Table 5.
+
+**Table 5/T.503 – Presentation attributes**
+
+| Attributes                        | Basic values                                      | Default values                                    | Non-basic values                                                                                                                          |
+|-----------------------------------|---------------------------------------------------|---------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------|
+| Type of content                   | Formatted raster graphics<br>content architecture | Formatted raster graphics<br>content architecture | None                                                                                                                                      |
+| <i>Raster graphics attributes</i> |                                                   |                                                   |                                                                                                                                           |
+| Pel path                          | 0°                                                | 0°                                                | None                                                                                                                                      |
+| Line progression                  | 270°                                              | 270°                                              | None                                                                                                                                      |
+| Pel transmission<br>density       | 6 BMU<br>(200 pels/25.4 mm)                       | 6 BMU                                             | 5 BMU (240 pels/25.4 mm)<br>4 BMU (300 pels/25.4 mm)<br>3 BMU (400 pels/25.4 mm)<br>2 BMU (600 pels/25.4 mm)<br>1 BMU (1200 pels/25.4 mm) |
+
+### 6.4.2 Coding attributes
+
+Attributes applicable to content portions are defined in Table 6.
+
+**Table 6/T.503 – Attributes applicable to content portions**
+
+| Attributes                               | Qualifier | Basic values                   | Default value                  | Non-basic values                  |
+|------------------------------------------|-----------|--------------------------------|--------------------------------|-----------------------------------|
+| Content identifier layout                | nm        | As defined in<br>Rec. T.412    | None                           | None                              |
+| Type of coding                           | d         | Rec. T.6                       | Rec. T.6                       | T.85 single-progression           |
+| <i>Raster graphics coding attributes</i> |           |                                |                                |                                   |
+| Number of pels per line                  | d         | As defined in<br>Table 3/T.563 | As defined in<br>Table 3/T.563 | None                              |
+| Compression                              | d         | Compressed                     | Compressed                     | Uncompressed                      |
+| Number of discarded pels                 | d         | As defined in<br>Table 3/T.563 | As defined in<br>Table 3/T.563 | None                              |
+| Content information                      | m         | T.6 string                     | None                           | T.85 single-progression<br>string |
+
+# Annex A
+
+## Format of the values of the attributes "object identifier"
+
+The object identifiers of the specific layout object descriptions are composed of sequences of numbers, each of these numbers representing a particular level of the specific layout structure.
+
+The number assigned to the specific document layout root object description is "1". The subordinate pages have a second number which uniquely identifies a particular page. The delimiter between "1" and this second number is the "space" character.
+
+### *Example*
+
+"1 27" corresponding coding: '31 20 32 37'H
+
+where character "1" is coded 03/01 or 31 in hexadecimal;
+
+where character "space" is coded 02/00 or 20 in hexadecimal;
+
+where character "2" is coded 03/02 or 32 in hexadecimal;
+
+and where character "7" is coded 03/07 or 37 in hexadecimal.
+
+Content portion identifiers are composed of the identifier of the page to which the content portion belongs and an additional number which identifies the content portion.
+
+### *Examples*
+
+page description "1 27" coding: '31203237'H
+
+content portion associated with the page "1 27 1" coding: '312032372031'H (optional)
+
+The value of the attribute "content portions" consists of a single number, which indicates the content portion of that object. This number is equal to the last number in the content portion identifier.
+
+# Annex B
+
+## Extension for continuous-tone colour and gray-scale image documents
+
+## **B.1 Introduction**
+
+This annex defines a document application profile in order to interchange continuous-tone colour and gray-scale image documents as an option of Group 4 facsimile documents.
+
+Its purpose is to specify an interchange format suitable for the interchange of Group 4 continuous-tone image facsimile documents that contain only continuous-tone raster graphics.
+
+Continuous-tone image documents are interchanged in a formatted form, which enables the receiver to display or print the document as intended by the originator.
+
+It is assumed that, when negotiation is performed by the service using this document application profile, all non-basic and additional features are subject to negotiation.
+
+## **B.2 References**
+
+- CCITT Recommendation T.81 (1992) | ISO/IEC 10918-1:1994, *Information technology – Digital compression and coding of continuous-tone still images – Requirements and guidelines*. (Commonly referred to as JPEG standard.)
+- ITU-T Recommendation T.42 (1996), *Continuous-tone colour representation method for facsimile*.
+
+## B.3 Definitions
+
+The definitions in ITU-T Recommendations T.411, T.81 and T.42 apply to this annex, unless explicitly amended.
+
+**B.3.1 JPEG:** Joint Photographic Experts Group, and also shorthand for the encoding method, described in Recommendation T.81, which was defined by this group.
+
+## B.4 Characteristics supported by this document application profile
+
+### B.4.1 Overview
+
+A Group 4 continuous-tone image facsimile document is the result of a formatting process and, therefore, the purpose of this document application profile is to allow transfer of the complete layout of the document.
+
+Only one category of content is allowed within the same page, namely: raster graphics content as used by facsimile Group 4 apparatus.
+
+The purpose of this document application profile is to allow transfer of the complete colour and gray-scale information of the continuous-tone image document.
+
+This subclause specifies the functional description of colour and gray-scale related features supported by this document application profile. Other functional descriptions are specified in Clause 6.
+
+### B.4.2 Colour representation
+
+Colour representation defines colour specification method, for example, direct or indexed expression, colour space, scale and offset, and illuminant/white point. These are aligned to Recommendation T.42.
+
+The basic value is direct expression in CIE 1976 ( $L^* a^* b^*$ ) colour space (CIELAB). It is also the default value.
+
+The basic values for scale and offset are as follows:
+
+L, a, b: 8 or 12 bits integer value.
+
+$L^*$ ,  $a^*$ ,  $b^*$ : real value colour coordinates in CIELAB space.
+
+– 8 bits/colour component case:
+
+$$L = (255/100) * L^*$$
+
+$$a = (255/170) * a^* + 128$$
+
+$$b = (255/200) * b^* + 96$$
+
+Rounding to the nearest integer is performed. If L, a, or b fall outside the range [0, 255], they are truncated to 0 or 255 as appropriate.
+
+– 12 bits/colour component case:
+
+$$L = (4095/100) * L^*$$
+
+$$a = (4095/170) * a^* + 2048$$
+
+$$b = (4095/200) * b^* + 1536$$
+
+Rounding to the nearest integer is performed. If L, a, and b fall outside the range [0, 4095], they are truncated to 0 or 4095 as appropriate.
+
+These are also the default values, and aligned to the following gamut range:
+
+$$L^* = [0, 100]$$
+
+$$a^* = [-85, 85]$$
+
+$$b^* = [-75, 125]$$
+
+Other values are non-basic value.
+
+The basic illuminant is "CIE Illuminant D50 and its perfectly diffuse reflecting white point ( $X_0 = 96.422$ ,  $Y_0 = 100.000$ ,  $Z_0 = 82.521$ )". It is also the default value. Non-basic values are for further study.
+
+Bits per colour component attribute defines the number of bits used to represent each colour component of the image. Bits per colour component of gray-scale image is represented by three integers such as (8,0,0), that means  $L^*$  is 8 bits and other components are not present. Bits per colour components of colour image are represented by three positive integers such as (8,8,8) that means  $L^*$ ,  $a^*$  and  $b^*$  are 8 bits.
+
+The basic and default value is 8 bits gray-scale. The optional values are 12 bits gray-scale, 8 bits colour, and 12 bits colour. The 12 bits colour is an optional feature of 8 bits colour. If the receiver indicates the 12 bits color, it shall manage the 8 bits colour and 12 bits gray-scale.
+
+Implementation of more than twelve bits is for further study.
+
+## **B.5 Definition of the document application profile**
+
+### **B.5.1 Overview**
+
+The document architecture level is defined in 6.1.1.
+
+The content architecture level is raster graphics formatted content architecture level as it is defined in Table 5 and Table B.3.
+
+The coding method to be used is Recommendation T.81 (JPEG) encoding method, provided that it is indicated in the document profile. Application of Recommendation T.82 (JBIG) is for further study.
+
+The document profile level used in this document application profile is defined in Table B.1. Every document interchanged in accordance with this document application profile must include a document profile. Every non-basic and additional attribute value used in a document must be indicated in the document profile.
+
+The interchange format class used in this document application profile is "B", as defined in Recommendation T.415.
+
+Document structure, the attributes applicable to layout components, and the allowable attribute values for object descriptions are defined in Table 3.
+
+### **B.5.2 Content architecture for continuous-tone image**
+
+The following raster graphics content architecture level is used in this document application profile.
+
+#### **B.5.2.1 Raster graphic content architecture level**
+
+The type of coding to be used is as defined in Recommendation T.81 (JPEG).
+
+Its use is agreed by prior negotiation and is indicated in the document profile.
+
+The presentation attributes that may be used are defined in 6.4.1.
+
+#### **B.5.2.2 Coding attributes**
+
+Attributes applicable to content portions are defined in Tables B.3 and B.4.
+
+A continuous-tone colour raster graphic content is coded by T.81 encodings. Recommendation T.81 is the permissible value.
+
+For T.81 encoding, basic value is baseline mode with transmitted quantization and Huffman tables. Other modes, for example, extended sequential DCT, progressive DCT, Spatial lossless and using Arithmetic coding for entropy coding, are optional. The usage of this T.81 encoding is shown in B.8.
+
+The transmission of quantization and Huffman tables is mandatory. The attribute, "use of preferred Huffman table" is provided to indicate to the receiver that the preferred Huffman tables are used. In this case, the use of the preferred Huffman tables is indicated, the receiver can use the pre-installed preferred Huffman tables. Receiver must recognize Restart marker code and work appropriately. Hierarchical mode is for further study.
+
+## **B.6 Definition of the document application profile for soft-copy communication**
+
+For further study.
+
+## **B.7 Preferred Huffman tables for T.81 encoding**
+
+The preferred Huffman tables are Tables K.3/T.81 to K.6/T.81.
+
+## **B.8 JPEG data structure on continuous-tone image**
+
+### **B.8.1 Overview**
+
+JPEG data consists of Marker Codes, Frame Header, Scan Header and Compressed image data. In order to simplify Colour Facsimile Standard, Baseline JPEG and, optionally, certain JPEG extensions are supported. This subclause gives a description of the JPEG data structure.
+
+### **B.8.2 Marker classification**
+
+- 1) Encoder shall insert these Markers
+
+Decoder shall be able to carry out a corresponding process to these Marker segments:
+
+SOI, APP1, DQT, DHT, SOF0, SOS, EOI
+
+- 2) Encoder may insert this Marker without negotiation
+
+Decoder should be able to carry out a corresponding process to these Marker segments:
+
+DRI, RSTn, DNL
+
+- 3) Encoder may insert this Marker without negotiation
+
+Decoder should be able to skip these Marker segments and continue decoding process:
+
+COM, APPn (n not 1)
+
+- 4) Encoder may insert this Marker when Decoder has the ability to carry out a process corresponding to these Marker segments: (Negotiation is necessary)
+
+SOFn (n not 0)
+
+### **B.8.3 Definition of the APP markers defined for Group 4 Colour Fax**
+
+The application marker APP1 will initiate identification of the image as a G4FAX application and define the spatial resolution. This code appears directly after the SOI marker. The data format is as follows:
+
+X'FFE1'(APP1), length, G4FAX identifier, version, spatial resolution
+
+The above terms are defined as follows:
+
+- *Length:* (2 octets) Total APP1 field octet count including the octet count itself, but excluding the APP1 marker.
+- *FAX identifier:* (6 octets) X'47', X'34', X'46', X'41', X'58', X'00'. This X'00'-terminated string "G4FAX" uniquely identifies this APP1 marker.
+- *Version:* (2 octets) X'07CA'. This string specifies the year of approval of the standard, for identification in the case of future revision (for example, 1994).
+- *Spatial resolution:* (2 octets) Lightness pixel density in pels/25.4 mm. The basic value is 200. Allowed values are 200, 240, 300, 400, 600 and 1200.
+
+This is an example of the string including the SOI and APP1 codes for a baseline JPEG encoded 1994 G4FAX application at 200 pels/25.4 mm:
+
+X'FFD8', X'FFE1', X'000C', X'47', X'34', X'46', X'41', X'58', X'00', X'07CA', X'00C8'
+
+#### B.8.3.1 FAX option identifier – G4FAX1 for gamut range
+
+X'FFE1' (APP1), length, G4FAX option identifier, gamut range data
+
+The above terms are defined as follows:
+
+- *Length:* (2 octets) Total APP1 field octet count including the octet count itself, but excluding the APP1 marker.
+- *FAX identifier:* (6 octets) X'47', X'34', X'46', X'41', X'58', X'01'. This X'01'-terminated string "G4FAX" uniquely identifies this APP1 marker as containing FAX information about optional gamut range data. (The FAX option identifiers are referred to as G4FAX1–G4FAX255, meaning the octet-terminated string, "G4FAX", X'nn'.)
+- *Gamut range data:* (12 octets) The data field contains six two-octet signed integers. For example: X'0064' represents 100. The calculation from a real value  $L^*$  to an eight bit value,  $L$ , is made as follows;
+
+$$L = (255/Q) * L^* + P$$
+
+where the first integer of the first pair,  $P$ , contains the offset of the zero point in  $L^*$  in the eight most significant bits. The second integer of the first pair,  $Q$ , contains the span of the gamut range in  $L^*$ . Rounding to the nearest integer is performed. The second pair contains offset and range values for  $a^*$ . The third pair contains offset and range values for  $b^*$ . If the image is gray-scale ( $L^*$  only), the field still contains six integers, but the last four integers are ignored.
+
+NOTE – This representation is in accord with Recommendation T.42. when the twelve bits/pel/component option is used, the range and offset are represented as above in eight bits. These represent the eight most significant bits of the zero-padded twelve-bit number in the offset, and the eight-bit integer range data as above. Appropriately higher precision calculation should be used.
+
+For example, the gamut range  $L^* = [0, 100]$ ,  $a^* = [-85, 85]$ , and  $b^* = [-75, 125]$  would be selected by the code:
+
+X'FFE1', X'0014', X'47', X'34', X'46', X'41' X'58', X'01', X'0000', X'0064', X'0080', X'00AA', X'0060', X'00C8'
+
+#### B.8.3.2 FAX option identifier – G4FAX2 for illuminant data
+
+X'FFE1' (APP1), length, G4FAX option identifier, illuminant data. This option is for further study with the exception of the default case; the specification of the default illuminant, CIE Illuminant D50, may be added for information.
+
+- *Length:* (2 octets) Total APP1 field octet count including the octet count itself, but excluding the APP1 marker.
+- *FAX identifier:* (6 octets) X'47', X'34', X'46', X'41', X'58', X'02'. This X'02'-terminated string "G4FAX" uniquely identifies this APP1 marker as containing optional illuminant data.
+- *Illuminant data:* (4 octets) The data consist of a four-octet code identifying the illuminant. In the case of a CIE standard illuminant, the four-octet code is one of the following:
+  - CIE Illuminant D50: X'00', X'44', X'35', X'30'
+  - CIE Illuminant D65: X'00', X'44', X'36', X'35'
+  - CIE Illuminant D75: X'00', X'44', X'37', X'35'
+  - CIE Illuminant SA: X'00', X'00', X'53', X'41'
+  - CIE Illuminant SC: X'00', X'00', X'53', X'43'
+  - CIE Illuminant F2: X'00', X'00', X'46', X'32'
+  - CIE Illuminant F7: X'00', X'00', X'46', X'37'
+  - CIE Illuminant F11: X'00', X'46', X'31', X'31'
+
+In the case of a colour temperature alone, the four-octet code consists of the string "CT", followed by the temperature of the source in degrees K represented by an unsigned two-octet integer. For example, a 7500 K illuminant is indicated by the code:
+
+X'FFE1', X'000C', X'47', X'34', X'46', X'41', X'58', X'02', X'43', X'54', X'1D4C'
+
+#### B.8.3.3 Future option identifiers – G4FAX3 to G4FAX255
+
+In addition to the G4FAX1 and G4FAX2 identifiers used for specifying optional parameters, the identifiers from G4FAX3 to G4FAX255 are to be reserved for future use.
+
+### B.8.4 Example of JPEG data structure for a 4:1:1 subsampled baseline mode
+
+|                |                                                                                                                |
+|----------------|----------------------------------------------------------------------------------------------------------------|
+| SOI            | (start of image marker)                                                                                        |
+| APP1, Lp       | (application marker one, marker segment length)                                                                |
+| Api            | (application data octets: "G4FAX", X'00', X'07CA' (version), X'00C8' (200 dpi))                                |
+| (APP1, Lp)     | ((application marker one, marker segment length)                                                               |
+| Api            | (application data octets: "G4FAX", X'01', X'0000', X'0064', X'0080', X'00AA', X'0060', X'00C8' (gamut range))) |
+| (COM, Lc, Cmi) | (comment marker, marker segment length, comment octets)                                                        |
+| DHT, Lh        | (define Huffman table marker, Huffman table length definition)                                                 |
+| Tc, Th         | (table class Tc = 0 for DC, destination identifier Th = 0 for L*)                                              |
+| Li, Vij        | (number of codes for each of the 16-allowed code lengths, code values)                                         |
+| Tc, Th         | (table class Tc = 1 for AC, destination identifier Th = 0 for L*)                                              |
+| Li, Vij        | (number of codes for each of the 16-allowed code lengths, code values)                                         |
+| Tc, Th         | (table class Tc = 0 for DC, destination identifier Th = 1 for a*, b*)                                          |
+| Li, Vij        | (number of codes for each of the 16-allowed code lengths, code values)                                         |
+| Tc, Th         | (table class Tc = 1 for AC, destination identifier Th = 1 for a*, b*)                                          |
+| Li, Vij        | (number of codes for each of the 16-allowed code lengths, code values)                                         |
+| DQT, Lq        | (define quantization table marker, quantization table length definition)                                       |
+| Pq, Tq         | (element precision Pq = 0 for 8 bit, destination identifier Tq = 0 for lightness)                              |
+| Qk             | (64 quantization table elements for quantization table 0 (lightness))                                          |
+| Pq, Tq         | (element precision Pq = 0 for 8 bit, destination identifier Tq = 1 for chrominance)                            |
+| Qk             | (64 quantization table elements for quantization table 1 (chrominance))                                        |
+| (DRI, Lr, Ri)  | (define restart interval marker, marker segment length, restart interval in MCUs)                              |
+| SOF0, Lf       | (Start of frame marker for baseline, frame header length)                                                      |
+| P, Y, X        | (sample precision P = 8, number of lines Y, number of samples per line X)                                      |
+| Nf             | (number of image components Nf = 3 for colour)                                                                 |
+| C1             | (component identifier C1 = 0 for L* component)                                                                 |
+| H1, V1         | (horizontal and vertical sampling factors: H1 = 2, V1 = 2 for L* in colour 4:1:1)                              |
+| Tq1            | (quantization table selector: Tq1 = 0)                                                                         |
+| C2             | (component identifier C2 = 1 for a* component)                                                                 |
+| H2, V2         | (horizontal and vertical sampling factors: H2 = 1, V2 = 1 for a* in colour 4:1:1)                              |
+
+|              |                                                                                    |
+|--------------|------------------------------------------------------------------------------------|
+| Tq2          | (quantization table selector: Tq2 = 1)                                             |
+| C3           | (component identifier C3 = 2 for b* component)                                     |
+| H3, V3       | (horizontal and vertical sampling factors: H3 = 1, V3 = 1 for b* in colour 4:1:1)  |
+| Tq3          | (quantization table selector: Tq3 = 1)                                             |
+| SOS, Ls, Ns  | (Start of scan marker, scan header length, number of components Ns = 3 for colour) |
+| Cs1          | (scan component selector Cs1 = 0 for L*)                                           |
+| Td1, Ta1     | (DC entropy coding table selector Td1 = 0, AC table selector Ta1 = 0 for L*)       |
+| Cs2          | (scan component selector Cs2 = 1 for a*)                                           |
+| Td2, Ta2     | (DC entropy coding table selector Td2 = 1, AC table selector Ta2 = 1 for a*)       |
+| Cs3          | (scan component selector Cs3 = 2 for b*)                                           |
+| Td3, Ta3     | (DC entropy coding table selector Td3 = 1, AC table selector Ta3 = 1 for b*)       |
+| Ss, Se       | (Ss = 0 for sequential DCT, Se = 63 for sequential DCT)                            |
+| Ah, Al       | (Ah = 0 for sequential DCT, Al = 0 for sequential DCT)                             |
+| Scan data    | (compressed image data)                                                            |
+| (with RSTn)  | (restart marker between image data segments, with n = 0-7 repeating in sequence)   |
+| (DNL, Ld, Y) | (define number of lines marker, marker segment length, number of lines)            |
+| EOI          | (End of Image Marker)                                                              |
+
+NOTE – Parentheses around a marker indicate the marker is classified to (2), (3) or (4).
+
+### B.8.5 Scan data structure
+
+The scan data of the baseline mode consists of block interleaved L\*, a\*, and b\* data. Blocks are entropy-encoded DCT-transformed  $8 \times 8$  arrays of image data from a single image component. The L\*, a\* and b\* components are assigned indices zero, one, and two respectively in the frame header. When a gray-scale image is transmitted, only the L\* component is represented in the data structure. The number of image components is either one (for a gray-scale image) or three (for a colour image).
+
+The data are block-interleaved when a colour image is transmitted, and only one scan is contained within the image data. The blocks are organized in minimum coding units (MCU) such that an MCU contains a minimum integral number of all image components. The interleaving has the following form in the default (4:1:1) subsampling case, as defined in A.2.3/T.81. In this case an MCU consists of four blocks of L\* data, one block of a\* data, and one block of b\* data. The data are ordered L\*, L\*, L\*, L\*, a\*, b\* in the MCU. The four L\* blocks proceed in the same scan order as the page: left to right and top to bottom. Therefore the L\* blocks are transmitted first upper left, then upper right, then lower left, then lower right.
+
+### B.8.6 Subsampling method
+
+The default (4:1:1) subsampling is specified as a four-tap symmetric filter. Thus a\* and b\* are computed from non-sampled data by averaging the four values of chrominance at the lightness locations. The location of the subsampled chrominance pixel is shown in Figure B.1.
+
+![](5445597cceefaca1ac89e710fe339325_img.jpg)
+
+|          |          |
+|----------|----------|
+| X      X | X      X |
+| O        | O        |
+| X      X | X      X |
+| X      X | X      X |
+| O        | O        |
+| X      X | X      X |
+
+X Represents lightness pel centre  
+O Represents chrominance pel centre
+
+**Figure B.1/T.503 – Position of lightness and chrominance samples (4:1:1 subsampling) within the MCUs**
+
+**Table B.1/T.503 – Document profile attributes**
+
+| Attribute                                                                                                                             | Class | Permissible value                                     | Default                                    |
+|---------------------------------------------------------------------------------------------------------------------------------------|-------|-------------------------------------------------------|--------------------------------------------|
+| Document profile descriptor                                                                                                           | M     |                                                       |                                            |
+| Specific layout structure                                                                                                             | m     | Present                                               | –                                          |
+| Document characteristics                                                                                                              | M     |                                                       |                                            |
+| Document application profile                                                                                                          | m     | Group 4 fax colour extension (Note)                   | –                                          |
+| Document architecture class                                                                                                           | m     | Formatted                                             | –                                          |
+| Non-basic document characteristics                                                                                                    | M     |                                                       |                                            |
+| Type of coding                                                                                                                        | m     | JPEG (T.81)                                           |                                            |
+| Page dimensions                                                                                                                       | nm    | (Table 1)                                             | ISO A4<br>(9920, 14 030 fixed or variable) |
+| Raster graphics coding attributes                                                                                                     | NM    |                                                       |                                            |
+| Bit per colour component                                                                                                              | nm    | Gray-scale 12 bits<br>Colour 8 bits<br>Colour 12 bits | Gray-scale 8 bits                          |
+| Subsampling                                                                                                                           | nm    | 2:1:1, 1:1:1                                          | 4:1:1                                      |
+| JPEG coding mode                                                                                                                      | nm    | (Table B.4)<br>(without baseline)                     | Baseline                                   |
+| Raster graphics presentation attributes                                                                                               | NM    |                                                       |                                            |
+| Pel transmission density                                                                                                              | nm    | (Tables 1 and B.5)                                    | 6 BMU in Table 1                           |
+| Additional Document characteristics                                                                                                   | NM    |                                                       |                                            |
+| Colour space list                                                                                                                     | NM    |                                                       |                                            |
+| Colour space                                                                                                                          | NM    |                                                       |                                            |
+| Colour space id                                                                                                                       | m     | 1                                                     | –                                          |
+| Colour space type                                                                                                                     | m     | CIELAB                                                | –                                          |
+| Colour data scaling                                                                                                                   | nm    | (Table B.2)                                           | (Table B.2)                                |
+| Calibration data                                                                                                                      | nm    | (Table B.2)                                           | (Table B.2)                                |
+| NOTE – The identifier 05H means continuous-tone colour and gray-scale extension for Group 4 facsimile, and it shall be used as 0205H. |       |                                                       |                                            |
+
+
+
+**Table B.5/T.503 – Attributes applicable to Pel transmission density for optional colour and gray-scale mode**
+
+| Attribute                | Permissible value                                                                                                                                                                                                                                                                  |
+|--------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Pel transmission density | colour/gray-scale 12 BMU (100 pels/25.4 mm)<br>colour/gray-scale 6 BMU (200 pels/25.4 mm)<br>colour/gray-scale 4 BMU (300 pels/25.4 mm)<br>colour/gray-scale 3 BMU (400 pels/25.4 mm)<br>colour/gray-scale 2 BMU (600 pels/25.4 mm)<br>colour/gray-scale 1 BMU (1200 pels/25.4 mm) |
+
+## B.9 ASN.1 definition for this annex
+
+This abstract syntax definition of user data conveyed by session PDU is used for Group 4 continuous-tone colour and gray-scale facsimile document communication, using this annex, Recommendation T.521, "Communication application profile BT0 for document bulk transfer based on the session service", and Recommendation T.563, "Terminal characteristics for Group 4 facsimile apparatus".
+
+### B.9.1 User data conveyed by SUD in CSS/RSSP
+
+```
+
+APDU      ::= CHOICE {
+                                [4] IMPLICIT ApplicationCapabilities }
+
+ApplicationCapabilities ::= SET {
+    documentApplicationProfile [0] IMPLICIT OCTET STRING,
+        -- '0205'H document application profile for T.503 and this annex
+        -- '02'H indicates T.503 capability,
+        -- '05'H indicates annex "Extension For Continuous-Tone Colour and Gray-scale
+        -- Image Documents" capability.
+    documentArchitectureClass [1] IMPLICIT OCTET STRING    }
+        --'00'H FDA 'Formatted Document Architecture'--
+
+-- Coded example --
+A4      07                ApplicationCapabilities
+        80      02      02      05  documentApplicationProfile = T.503 and this annex
+        81      01      00                documentArchitectureClass = FDA
+    
+```
+
+### B.9.2 User data conveyed by SUD in CDCL/RDCLP
+
+```
+
+APDU      ::= CHOICE {
+                                [4] IMPLICIT ApplicationCapabilities }
+
+ApplicationCapabilities ::= SET {
+    documentApplicationProfile  [0] IMPLICIT OCTET STRING,
+        -- '0205'H document application profile for T.503 and this annex
+    documentArchitectureClass  [1] IMPLICIT OCTET STRING,
+        -- '00'H FDA --
+    nonBasicDocCharacteristics [2] IMPLICIT NonBasicDocCharacteristics,           -- (see Note)
+    additional-doc-characteristics [9] IMPLICIT Additional-Doc-Characteristics  OPTIONAL }
+
+NonBasicDocCharacteristics ::= SET {
+    page-dimensions           [2] IMPLICIT SET OF Dimension-Pair                OPTIONAL,
+    ra-gr-coding-attributes   [3] IMPLICIT SET OF Ra-Gr-Coding-Attribute        OPTIONAL,
+    ra-gr-presentation-features [4] IMPLICIT SET OF Ra-Gr-Presentation-Features OPTIONAL,
+    types-of-coding           [29] IMPLICIT SET OF Type-of-Coding                } -- (see Note)
+    
+```
+
+NOTE – These attributes are mandatory for this annex.
+
+```
+
+Dimension-Pair      ::= SEQUENCE {
+    horizontal        [0] IMPLICIT INTEGER,
+    vertical          CHOICE {
+        fixed          [0] IMPLICIT INTEGER,
+        variable       [1] IMPLICIT INTEGER } }
+        -- North American letter      = (10200,13200 fixed or variable)
+        -- ISO B4                     = (11811,16677 fixed or variable)
+        -- ISO A3                     = (14030,19840 fixed or variable)
+    
+```
+
+-- Japanese legal = (12141,17196 fixed or variable)  
+-- Japanese letter = (8598,12141 fixed or variable)  
+-- North American legal = (10200,16800 fixed or variable)  
+-- North American ledger = (13200,20400 fixed or variable)  
+-- ISO A4 = (9920,14030 fixed or variable)  
+-- default value is ISO A4 = (9920,14030 fixed)  
+-- basic value is ISO A4 = (9920,14030 fixed or variable)
+
+**Ra-Gr-Coding-Attribute ::= CHOICE {**  
+    **bit-per-colour-component** [4] **Bit-Per-Colour-Component OPTIONAL,**  
+    **subsampling** [10] **IMPLICIT Subsampling OPTIONAL,**  
+    **jpeg-coding-mode** [11] **IMPLICIT INTEGER {**  
+        -- *Huffman coding*  
+            **extended-sequential-DCT (1),**  
+            **progressive-DCT (2),**  
+            **spatial-lossless (3),**  
+        -- *arithmetic coding*  
+            **extended-sequential-DCT (9),**  
+            **progressive-DCT (10),**  
+            **spatial-lossless (11)} OPTIONAL }**  
+-- default and basic value is baseline (0)
+
+**Bit-Per-Colour-Component ::= CHOICE {**  
+    **component-list SEQUENCE OF INTEGER }**  
+        -- gray-scale 12 bits = (12, 0, 0)  
+        -- colour 8 bits = (8, 8, 8)  
+        -- colour 12 bits = (12, 12, 12)  
+-- default and basic value is gray-scale 8 bits (8,0,0) for this annex
+
+**Subsampling ::= OCTET STRINGS**  
+    -- 2:1:1 or 4:2:2 ((2,1),(1,1),(1,1)) : '21 11 11'H  
+    -- 1:1:1 ((1,1),(1,1),(1,1)) : '11 11 11'H  
+    -- (4:1:1 ((2,2),(1,1),(1,1)) : '22 11 11'H )  
+-- default and basic value is 4:1:1 ((2,2),(1,1),(1,1))
+
+**Ra-Gr-Presentation-Features ::= CHOICE {**  
+    **pel-transmission-density [11] IMPLICIT Pel-Transmission-Density }**
+
+**Pel-Transmission-Density ::= INTEGER {**  
+    **p5 (2),** -- 5 BMU (240 pels/25.4 mm)  
+    **p4 (3),** -- 4 BMU (300 pels/25.4 mm)  
+    **p3 (4),** -- 3 BMU (400 pels/25.4 mm)  
+    **p2 (5),** -- 2 BMU (600 pels/25.4 mm)  
+    **p1 (6),** -- 1 BMU (1200 pels/25.4 mm)  
+    **colour/gray-scale p12 (10),** -- 12 BMU (100 pels/25.4 mm)  
+    **colour/gray-scale p6 (11),** -- 6 BMU (200 pels/25.4 mm)  
+    **colour/gray-scale p4 (13),** -- 4 BMU (300 pels/25.4 mm)  
+    **colour/gray-scale p3 (14),** -- 3 BMU (400 pels/25.4 mm)  
+    **colour/gray-scale p2 (15),** -- 2 BMU (600 pels/25.4 mm)  
+    **colour/gray-scale p1 (16),** -- 1 BMU (1200 pels/25.4 mm)  
+    **(p6 (1))}** -- 6 BMU (200 pels/25.4 mm)  
+-- default and basic value is p6 (1)
+
+**Type-of-Coding ::= CHOICE { [6]IMPLICIT OBJECT IDENTIFIER }**  
+    -- {2 8 3 7 13} for 'JPEG' encoding  
+-- basic value is T.81"JPEG" {2 8 3 7 13} for this annex  
+-- T.82"JBIG" is for further study.
+
+**Additional-Doc-Characteristics ::= SET {**  
+    **colour-spaces-list [1] IMPLICIT SET OF Colour-Spaces OPTIONAL}**
+
+**Colour-Space ::= SET {**  
+    **colour-space-id [0] IMPLICIT INTEGER,**  
+    **colour-space-type [1] IMPLICIT Colour-Space-Type,**  
+    **colour-data-scaling [4] IMPLICIT Colour-Data-Scaling OPTIONAL }**
+
+**Colour-Space-Type ::= INTEGER { cielab(4) }**
+
+**Colour-Data-Scaling ::= SET {**  
+    **first-component [0] IMPLICIT Scale-and-Offset,**  
+    **second-component [1] IMPLICIT Scale-and-Offset,**  
+    **third-component [2] IMPLICIT Scale-and-Offset }**
+
+Scale-and-Offset ::= SET {  
+ colour-scale [0] REAL,  
+ colour-offset [1] REAL }
+
+-- default and basic values for CIELAB components are as follows:
+
+|                  | scale          | offset |
+|------------------|----------------|--------|
+| first-component  | 2.55(255/100)  | 0      |
+| second-component | 1.5(255/170)   | 128    |
+| third-component  | 1.275(255/200) | 96     |
+
+-- Coded example --
+
+```
+
+A4  LL      ApplicationCapabilities
+    80  02  02  05  documentApplicationProfile = T.503 and this annex
+    81  01  00      documentArchitectureClass = FDA
+    A2  46      nonBasicDocCharacteristics
+      A2  14      page-dimensions
+        30  08      SEQUENCE (ISO B4 variable)
+          80  02  2E23      horizontal = 11811 BMU
+          81  02  4125      vertical = variable 16677 BMU
+        30  08      SEQUENCE (ISO A3 variable)
+          80  02  36CE      horizontal = 14030 BMU
+          81  02  4D80      vertical = variable 19840 BMU
+      A3  15      ra-gr-coding-attributes
+      A4  0B  30  09
+          02  01  08  bit-per-colour-component = 8 (colour 8 bits)
+          02  01  08
+          02  01  08
+          8A  03  111111  subsampling = '11 11 11'H ((1,1),(1,1),(1,1))
+          8B  01  01      jpeg-coding-mode = 1 (extended-sequential-DCT)
+      A4  0F      ra-gr-presentation-features
+          8B  01  03      peltransmission-density = 3 (300 pels/25.4 mm)
+          8B  01  04      peltransmission-density = 4 (400 pels/25.4 mm)
+          8B  01  0B      peltransmission-density = 11 (colour/gray-scale
+                        200 pels/25.4 mm)
+          8B  01  0D      peltransmission-density = 13 (colour/gray-scale
+                        300 pels/25.4 mm)
+          8B  01  0E      peltransmission-density = 14 (colour/gray-scale
+                        400 pels/25.4 mm)
+      BD  06      type-of coding
+          86  04  58 03 07 0D  = {2 8 3 7 13} (T.81"JPEG")
+      A9  3C      additional-doc-characteristics
+          A1  3A      colour-space-list
+              31  38      colour space SET
+              80  01  01      colour-space-id = 1
+              81  01  04      colour-space-type = 4 (CIELAB)
+              A4  30      colour-data-scaling (non basic value case)
+                  A0  0C      first-component L* = [0, 95]
+                      A0  06      colour-scale = 2.684 (255/95)
+                          09  04  A0  FD  2AF2
+
+-- REAL length = 4 binary encoding (base = 16) exponent = -3 mantissa = '2AF2'H
+    A1  02      colour-offset = 0
+    09  00
+
+-- REAL length = 0 (this means real value is '0')
+    A1  0F      second-component a* = [-85, 85]
+    A0  06      colour-scale = 1.5 (255/170)
+    09  04  A0  FD  18  00
+
+```
+
+|    |    |    |    |    |       |                                 |
+|----|----|----|----|----|-------|---------------------------------|
+| A1 | 05 |    |    |    |       | colour-offset = 128             |
+|    | 09 | 03 | A0 | 00 | 80    |                                 |
+| A2 | 0F |    |    |    |       | third-component b* = [-75, 125] |
+| A0 | 06 |    |    |    |       | colour-scale = 1.275 (255/200)  |
+|    | 09 | 04 | A0 | FD | 14 66 |                                 |
+| A1 | 05 |    |    |    |       | colour-offset = 96              |
+|    | 09 | 03 | A0 | 00 | 60    |                                 |
+
+### B.9.3 User data conveyed by SUD in CDS
+
+**S-ACTIVITY-START-user-data ::= CHOICE {**  
+**[4] IMPLICIT DocumentCharacteristics }**
+
+**DocumentCharacteristics ::= SET {**  
+**documentApplicationProfile [0] IMPLICIT OCTET STRING,**  
+*-- '05'H for T.503 and this annex*  
+**documentArchitectureClass [1] IMPLICIT OCTET STRING,**  
+*-- '00'H FDA*  
+**nonBasicDocCharacteristics [2] IMPLICIT NonBasicDocCharacteristics,**  
+**additional-doc-characteristics [9] IMPLICIT Additional-Doc-Characteristics OPTIONAL}**  
+*-- See B.9.2 (except documentApplicationProfile)*
+
+### B.9.4 Layout Object Descriptor (document layout root) conveyed by CSUI/CDUI
+
+ASN.1 definition of Layout Object Descriptor (document layout root) conveyed by CSUI/CDUI is identical with conventional Group 4 facsimile. The following are only examples.
+
+**Interchange-Data-Element ::= CHOICE {**  
+**layout-object [2] IMPLICIT Layout-Object-Descriptor }**
+
+**Layout-Object-Descriptor ::= SEQUENCE {**  
+**object-type Layout-Object-Type,**  
+**descriptor-body Layout-Object-Descriptor-Body OPTIONAL }**
+
+**Layout-Object-Type ::= INTEGER {document-layout-root (0) }**
+
+**Layout-Object-Descriptor-Body ::= SET {**  
+**object-identifier Object-or-Class-Identifier OPTIONAL,**  
+**subordinates [0] IMPLICIT SEQUENCE OF NumericString OPTIONAL,**  
+**default-value-lists [7] IMPLICIT Default-Value-Lists-Layout OPTIONAL}**
+
+**Object-or-Class-Identifier ::= [APPLICATION 1]IMPLICIT PrintableString**  
+*-- only digits and space are used in the present version*  
+*-- of the standard; other characters are reserved for extensions;*  
+*-- a "null" value is represented by an empty string.*
+
+**Default-Value-Lists-Layout ::= SET {**  
+**page-attributes [2] IMPLICIT Page-Attributes OPTIONAL }**
+
+**Page-Attributes ::= SET {**  
+**dimensions < Attributes OPTIONAL,**  
+**presentation-attributes < Attributes OPTIONAL}**
+
+**Attributes ::= CHOICE {**  
+**dimensions [1] IMPLICIT Dimension-Pair }**  
+**presentation-attributes [3] IMPLICIT Presentation-Attributes}**
+
+**Dimension-Pair ::= SEQUENCE {**  
+**horizontal [0] IMPLICIT INTEGER,**  
+**vertical CHOICE {**  
+**fixed [0] IMPLICIT INTEGER,**  
+**variable [1] IMPLICIT INTEGER }**
+
+*-- Coded example is shown in Appendix II/T.563 --*
+
+### B.9.5 Layout Object Descriptor (page) conveyed by CSUI/CDUI
+
+ASN.1 definition of Layout Object Descriptor (page) conveyed by CSUI/CDUI is identical to conventional Group 4 facsimile. The following are only examples.
+
+```
+Interchange-Data-Element ::= CHOICE {
+    layout-object          [2] IMPLICIT Layout-Object-Descriptor }
+
+Layout-Object-Descriptor ::= SEQUENCE {
+    object-type             Layout-Object-Type,
+    descriptor-body         Layout-Object-Descriptor-Body          OPTIONAL }
+
+Layout-Object-Type        ::= INTEGER { page (2) }
+
+Layout-Object-Descriptor-Body ::= SET {
+    object-identifier       Object-or-Class-Identifier             OPTIONAL,
+    content-portions        [1] IMPLICIT SEQUENCE OF NumericString OPTIONAL,
+    dimensions              [4] IMPLICIT Dimension-Pair            OPTIONAL,
+    presentation-attributes [6] IMPLICIT Presentation-Attributes   OPTIONAL}
+
+Presentation-Attributes   ::= SET {
+    content-type            Content-Type OPTIONAL,
+    raster-graphics-attributes [1] IMPLICIT Raster-Graphics-Attributes OPTIONAL}
+
+Content-Type              ::= [APPLICATION 2]IMPLICIT INTEGER
+                           {formatted-raster-graphics (1) }
+
+Raster-Graphics-Attributes ::= SET {
+    pel-path                [0] IMPLICIT One-of-Four-Angles         OPTIONAL,
+    line-progression         [1] IMPLICIT One-of-Two-Angles         OPTIONAL,
+    pel-transmission-density [2] IMPLICIT Pel-Transmission-Density  -- mandatory for this annex
+
+One-of-Four-Angles ::= INTEGER {d0 (0)} -- 0 --
+-- default and basic value is d0 (0) --
+One-of-Two-Angles  ::= INTEGER {d270 (3)} -- 270 --
+-- default and basic value is d270 (0) --
+
+-- Coded example is shown in Appendix II/T.563 --
+```
+
+### B.9.6 Content Portion conveyed by CSUI/CDUI
+
+```
+Interchange-Data-Element ::= CHOICE {
+    content-portion        [3] IMPLICIT Text-Unit }
+
+Text-Unit                 ::= SEQUENCE {
+    content-portion-attributes Content-Portion-Attributes          OPTIONAL,
+    content-information     Content-Information}
+
+Content-Portion-Attributes ::= SET {
+    content-identifier-layout Content-Portion-Identifier           OPTIONAL,
+    type-of-coding           Type-of-Coding, -- mandatory for this annex
+    coding-attributes        CHOICE {
+        raster-gr-coding-attributes [2] IMPLICIT Raster-Gr-Coding-Attributes} OPTIONAL}
+
+Content-Portion-Identifier ::= [APPLICATION 0]IMPLICIT PrintableString
+-- only digits and space are used in the present version of the
+-- standard; other characters are reserved for extensions.
+
+Type-of-Coding ::= CHOICE {
+    [6] IMPLICIT OBJECT IDENTIFIER }
+-- { 2 8 3 7 13 } for 'JPEG' encoding
+-- T.82 "JBIG" is for further study.
+
+Raster-Gr-Coding-Attributes ::= SET {
+    number-of-pels-per-line [0] IMPLICIT INTEGER                 OPTIONAL,
+    compression             [2] IMPLICIT Compression             OPTIONAL,
+    number-of-discarded-pels [3] IMPLICIT INTEGER                 OPTIONAL,
+    bit-per-colour-component [4] Bit-Per-Colour-Component         OPTIONAL,
+    subsampling              [10] IMPLICIT Subsampling            OPTIONAL,
+    jpeg-coding-mode         [11] IMPLICIT INTEGER {
+```
+
+```
+
+-- Huffman coding
+ baseline (0),
+ extended-sequential-DCT (1),
+ progressive-DCT (2),
+ spatial-lossless (3),
+-- arithmetic coding
+ extended-sequential-DCT (9),
+ progressive-DCT (10),
+ spatial-lossless (11)} OPTIONAL,
+use-of-preferred-huffman-table [14] IMPLICIT INTEGER {
+ no (0),
+ yes (1)} OPTIONAL}
+-- basic and default value is "no".
+
+```
+
+```
+
+Bit-Per-Colour-Component ::= CHOICE {
+ component-list SEQUENCE OF INTEGER }
+ -- gray-scale 12 bits = (12,0,0)
+ -- colour 8 bits = (8,8,8)
+ -- colour 12 bits = (12,12,12)
+ -- default and basic value is gray-scale 8 bits (8,0,0)
+
+```
+
+```
+
+Subsampling ::= OCTET STRINGS
+ -- 4:1:1 ((2,2),(1,1),(1,1)) : '22 11 11'H
+ -- 1:1:1 ((1,1),(1,1),(1,1)) : '11 11 11'H
+ -- 2:1:1 or 4:2:2 ((2,1),(1,1),(1,1)) : '21 11 11'H
+
+```
+
+```
+
+Content-Information ::= OCTET STRINGS
+ -- T.81 string --
+
+```
+
+-- Coded example --
+
+```
+
+A3 LL content-portion Text-Unit
+ 31 LL content-portion-attributes
+ 40 LL (XX YY) content-identifier-layout = (XX YY)
+ 86 04 58 03 07 0D = { 2 8 3 7 13 } (T.81 "JPEG")
+ A2 1C coding-attributes
+ 80 02 09 80 number-of-pels-per-line = 2432 (ISO A3)
+ 83 01 2F number-of-discarded-pels = 47 (ISO A3)
+ A4 0B 30 09
+ 02 01 08 bit-per-colour-component = (8,8,8) (colour 8 bits)
+ 02 01 08
+ 02 01 08
+ 8A 03 11 11 11 subsampling = '11 11 11'H (1:1:1)
+ 8B 01 01 jpeg-coding-mode = 1 (extended-sequential-DCT)
+ 24 80 content-information OCTET STRING (constructed)
+ 04 LL XXXXXXXXXXXX(T.81 string)XXXXXXXXXX OCTET STRING (primitive)
+ 04 LL XXXXXXXXXXXX(T.81 string)XXXXXXXXXX OCTET STRING (primitive)
+ 00 00 EOC
+ 00 00 EOC
+
+```
+
+---
+
+```
+
+A3 LL content-portion Text-Unit
+ 31 15 content-portion-attributes
+ 86 04 58 03 07 0D = { 2 8 3 7 13 } (T.81 "JPEG")
+ A2 0D coding-attributes
+ A4 0B 30 09
+ 02 01 08 bit-per-colour-component = (8,8,8) (colour 8 bits)
+ 02 01 08
+ 02 01 08
+ 04 LL XXXXXXXXXXXX(T.81 string)XXXXXXXXXX OCTET STRING (primitive)
+ (4:1:1 subsample JPEG data)
+
+```
+
+---
+
+# Annex C
+
+## Extension for colour and gray-scale image documents using Recommendation T.43
+
+## C.1 Introduction
+
+This annex defines a document application profile in order to interchange colour and gray-scale image documents using the lossless coding scheme defined in Recommendation T.43 as an option of Group 4 facsimile documents.
+
+Three types of image such as one bit per colour CMY(K) or RGB image, palettized colour image, and continuous-tone colour/gray-scale image are supported in this document application profile.
+
+Its purpose is to specify an interchange format suitable for the interchange of Group 4 colour and gray-scale image facsimile documents using lossless coding schemes.
+
+Colour and gray-scale image documents are interchanged in a formatted form, which enables the receiver to display or print the document as intended by the originator.
+
+It is assumed that, when negotiation is performed by the service using this document application profile, all non-basic and additional features are subject to negotiation.
+
+## C.2 References
+
+- ITU-T Recommendation T.43 (1997), *Colour and gray-scale image representations using lossless coding scheme for facsimile*.
+- ITU-T Recommendation T.82 (1993) | ISO/IEC 11544:1993, *Information technology – Coded representation of picture and audio information – Progressive bi-level image compression*. (Commonly referred to as JBIG standard.)
+
+## C.3 Definitions
+
+In addition to the definitions in this Recommendation, the definitions in Recommendations T.411, T.82, T.42 and T.43 apply to this annex, unless explicitly amended.
+
+**C.3.1 JBIG:** Joint Bi-level Image Experts Group, and also shorthand for the encoding method, described in Recommendation T.82, which was defined by this group.
+
+## C.4 Characteristics supported by this document application profile
+
+### C.4.1 Overview
+
+A lossless encoded Group 4 colour and gray-scale image facsimile document is the result of a formatting process, and therefore, the purpose of this document application profile is to allow transfer of the complete layout of the document using lossless coding schemes defined in Recommendation T.43.
+
+Only one category of content is allowed within the same page, namely: raster graphics content as used by facsimile Group 4 apparatus.
+
+The purpose of this document application profile is to allow transfer of the complete colour and gray-scale information of the lossless encoded colour and gray-scale image document.
+
+This subclause specifies the functional description of colour and gray-scale related features supported by this document application profile. Other functional descriptions are specified in this Recommendation.
+
+### C.4.2 Colour representation and encoding methods
+
+Three image types are used for this document application profile, namely, one bit per colour RGB/CMY(K) image, palettized colour image, and continuous-tone colour/gray-scale image. These images are encoded by the lossless coding scheme defined in Recommendation T.82 (JBIG). Colour representation, bit-plane decomposition and coding schemes of these types of images are defined in Recommendations T.43 and T.42.
+
+#### **C.4.2.1 One bit per colour CMY(K) or RGB image**
+
+This type of image is expressed by the precision of 1 bit/colour component using CMY(K) or RGB colour primaries. For this type of image, it is considered to be more desirable to map each colour onto one of the primary colours of receiver's side, rather than trying to reproduce the original colour by sending the coordinates in CIELAB space. The detailed specification for this mode such as colour transmission order is defined in Recommendation T.43.
+
+In one bit per colour image using three or four primaries [CMY(K) or RGB], 8 or 16 kinds of colours can be expressed. The colour representation is defined in Tables C.1/T.43 to C.3/T.43. Encoders can encode using either 3 or 4 bit-planes, and decoders shall support both 3 and 4 bit-planes. The bits per colour component attribute value of this mode shall be (1,1,1,1).
+
+#### **C.4.2.2 Palettized colour image**
+
+In this type of image, the colour image is expressed by colour indices of the palette table, in which each entry is expressed by the combination of three values of CIELAB colour components defined in Recommendation T.42. The number of indices of palettized colour is classified into two classes: 12 bits or less indices and up to 16 bits indices. Each colour component value precision is also classified into two classes, 8 bits/component precision and 12 bits/component precision.
+
+The resultant coding sub-mode of palettized colour image is classified into two classes by the combination of these two parameters. The first one is basic palettized colour sub-mode, in which the number of indices of palettized colour is 12 bits or less and colour co-ordinate precision is 8 bits/component. The other is the extended palettized colour sub-mode, in which either the number of indices of palettized colour is 13 to 16 bits and 8 bits/component precision table or 16 bits or less and 12 bits/component precision table. A more detailed specification for the palettized colour image is defined in Recommendation T.43.
+
+#### **C.4.2.3 Continuous-tone colour and gray-scale image**
+
+In this type of image, the colour image is represented by CIELAB colour space specified in Recommendation T.42, and the gray-scale image is represented by only L\* component of CIELAB colour space specified in Recommendation T.42. Two classes are specified for its data precision: 8 bits or less per component and 9 to 12 bits/component precision. In order to obtain high encoding efficiency, Gray code conversion is applied for this type of image in bit-plane coding. Detailed coding specification for this type of image is defined in Recommendation T.43.
+
+### **C.4.3 Coding mode classification**
+
+As described above, the three types of image are further divided into 7 coding sub-mode classes as shown in Table C.1. However, for the sake of easy negotiation, the supporting rule for coding sub-mode classes are established as described in Table C.2, in which two coding mode classes are defined for colour and gray-scale modes respectively.
+
+## **C.5 Definition of the document application profile**
+
+### **C.5.1 Overview**
+
+The document architecture level is defined as in this Recommendation.
+
+The content architecture level is raster graphics formatted content architecture level. In this annex, it is defined in Table 5 and Table C.3.
+
+The coding scheme to be used is defined in Recommendation T.43 in which Recommendation T.82 (JBIG) coding method is used for lossless coding. It is indicated as Recommendation T.43 in the document profile.
+
+The document profile level used in this document application profile is defined in Table C.3. Every document interchanged in accordance with this document application profile must include a document profile. Every non-basic and additional attribute value used in a document must be indicated in the document profile.
+
+The interchange format class used in this document application profile is "B", as defined in Recommendation T.415.
+
+Document structure, the attributes applicable to layout components, and the allowable attribute values for object descriptions are defined in Table C.3.
+
+**Table C.1/T.503 – Image mode and bits per colour component attribute**
+
+| Image type               | Coding sub-mode class                                                                                              | Image specification                                                                                                                                                                                                                         | Number of bit-planes to be coded                                                                                                                                                                                                               |
+|--------------------------|--------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| One bit per colour image | One bit per colour image                                                                                           | One bit per colour image using RGB or CMY(K) primaries                                                                                                                                                                                      | CMYK image: 4 bit-planes<br>CMY image: 3 bit-planes<br>RGB image: 3 bit-planes                                                                                                                                                                 |
+| Palettized colour image  | Basic palettized colour<br><br>Extended palettized colour                                                          | Palettized image using 12 bits or less entries and 8 bits/comp. precision table<br><br>Palettized image using 13 to 16 bits entries and 8 bits/comp. precision table<br><br>or<br>16 bits or less entries and 12 bits/comp. precision table | 1 to 12 bit-planes (palette-table: up to 4096 entries 3 octets/entry)<br><br>13 to 16 bit-planes (palette-table: 4097 to 65 536 entries 3 octets/entries)<br><br>or<br>1 to 16 bit-planes (palette-table: up to 65 536 entries 6 octets/entry) |
+| Continuous-tone image    | Colour<br>8 bits/comp. colour<br>12 bits/comp. colour<br><br>Gray-scale<br>8 bits gray-scale<br>12 bits gray-scale | 2 to 8 bits/comp.<br>9 to 12 bits/comp.<br>colour image<br><br>2 to 8 bits<br>9 to 12 bits<br>gray-scale image                                                                                                                              | 2*3 to 8*3 bit-planes<br>9*3 to 12*3 bit-planes<br><br>2 to 8 bit-planes<br>9 to 12 bit-planes                                                                                                                                                 |
+
+**Table C.2/T.503 – Colour and gray-scale coding mode classification**
+
+| Coding     |         | Bits per colour component value | Mode class        | Supporting coding sub-mode classes                                                                                                                                                                           |
+|------------|---------|---------------------------------|-------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Gray-scale | 8 bits  | (8,0,0)                         | Basic and default | 8 bits gray-scale image                                                                                                                                                                                      |
+|            | 12 bits | (12,0,0)                        | Optional          | 8 bits gray-scale image<br>12 bits gray-scale image                                                                                                                                                          |
+| Colour     | 8 bits  | (8,8,8)                         | Optional          | One bit per colour image<br>Basic palette colour image<br>8 bits gray-scale image<br>8 bits/comp. colour image                                                                                               |
+|            | 12 bits | (12,12,12)                      | Optional          | One bit per colour image<br>Basic palette colour image<br>8 bits gray-scale image<br>8 bits/comp. colour image<br>Extended palettized colour image<br>12 bits gray-scale image<br>12 bits/comp. colour image |
+
+### C.5.2 Content architecture for colour and gray-scale image using the lossless coding scheme
+
+The following raster graphics content architecture is used in this document application profile.
+
+#### C.5.2.1 Raster graphic content architecture level
+
+The type of coding to be used is Recommendation T.43.
+
+Its use is agreed by prior negotiation and is indicated in the document profile.
+
+The presentation attributes that may be used are defined in 6.4.1.
+
+#### C.5.2.2 Coding attributes
+
+Attributes applicable to content portions are defined in Table C.4.
+
+Colour and gray-scale raster graphic contents are coded by Recommendation T.43. Recommendation T.43 is the permissible and basic value. Coding procedure is defined in Recommendation T.43.
+
+**Table C.3/T.503 – Document profile attributes**
+
+| Attribute                               | Class | Permissible value                                                                    | Default                                 |
+|-----------------------------------------|-------|--------------------------------------------------------------------------------------|-----------------------------------------|
+| Document profile descriptor             | M     |                                                                                      |                                         |
+| Specific layout structure               | m     | Present                                                                              | –                                       |
+| Document characteristics                | M     |                                                                                      |                                         |
+| Document application profile            | m     | Group 4 fax colour extension for lossless coding 08H (Note 1)                        | –                                       |
+| Document architecture class             | m     | Formatted                                                                            | –                                       |
+| Non-basic document characteristics      | M     |                                                                                      |                                         |
+| Type of coding                          | m     | Rec. T.43                                                                            | (Note 2)                                |
+| Page dimensions                         | nm    | (Table 1)                                                                            | ISO A4 (9920, 14 030 fixed or variable) |
+| Raster graphics coding attributes       | NM    |                                                                                      |                                         |
+| Bit per colour component                | nm    | (8,8,8): 8 bits colour<br>(12,0,0): 12 bits gray-scale<br>(12,12,12): 12 bits colour | (8,0,0) 8 bits gray-scale               |
+| Interleaving                            | nm    | Plane                                                                                | Stripe (128 line) (Note 3)              |
+| Raster graphics presentation attributes | NM    |                                                                                      |                                         |
+| Pel transmission density                | nm    | (Tables 1 and B.5)                                                                   | 6 BMU in Table 1                        |
+| Additional document characteristics     | NM    |                                                                                      |                                         |
+| Colour space list                       | NM    |                                                                                      |                                         |
+| Colour space                            | NM    |                                                                                      |                                         |
+| Colour space id                         | m     | 1                                                                                    | –                                       |
+| Colour space type                       | m     | CIELAB                                                                               | –                                       |
+| Colour data scaling                     | nm    | (Table B.2)                                                                          | (Table B.2)                             |
+| Calibration data                        | nm    | (Table B.2)                                                                          | (Table B.2)                             |
+
+NOTE 1 – The identifier "08H" means colour or gray-scale extension using the lossless coding scheme defined in Recommendation T.43 for Group 4 facsimile, and it shall be used as "0208H". In the case where the terminal can use JPEG colour extension and Recommendation T.43 extension, the identifier shall be used as "020508H".
+
+NOTE 2 – The coding scheme in Recommendation T.43 is indicated by object ID {0 0 20 43 0}.
+
+NOTE 3 – If stripe interleave is specified, it indicates that the terminal has the capability to interchange the coded image data in stripe interleave format with equal or less than 128 lines per stripe. In order to use more than 128 lines per stripe format, plane interleave shall be specified.
+
+**Table C.4/T.503 – Attributes applicable to content portions**
+
+| Attribute                        | Qualifier | Basic value                 | Default value               | Non-basic value               |
+|----------------------------------|-----------|-----------------------------|-----------------------------|-------------------------------|
+| Content identifier               | nm        | As defined in Rec. T.412    | None                        | None                          |
+| Type of coding                   | m         | Rec. T.43                   | None                        | None                          |
+| Raster graphics coding attribute |           |                             |                             |                               |
+| Number of pels per line          | d         | As defined in Table 4/T.563 | As defined in Table 4/T.563 | None                          |
+| Number of discarded pels         | d         | As defined in Table 4/T.563 | As defined in Table 4/T.563 | None                          |
+| Bit per colour component         | d         | (8,0,0)                     | (8,0,0)                     | (8,8,8), (12,0,0), (12,12,12) |
+| Interleaving                     | d         | Stripe                      | Stripe                      | Plane (Note)                  |
+| Content information              | m         | Octet strings (T.43)        | None                        | None                          |
+
+NOTE – If stripe interleave is specified, it indicates that the terminal has the capability to interchange the coded image data in stripe interleave format with equal or less than 128 lines per stripe. In order to use more than 128 lines per stripe format, plane interleave shall be specified.
+
+## C.6 Definition of the document application profile for soft-copy communication
+
+For further study.
+
+## C.7 ASN.1 definition for this annex
+
+This abstract syntax definition of user data conveyed by session PDU is used for Group 4 colour and gray-scale facsimile document communication, using this annex, Recommendation T.521, "Communication application profile BT0 for document bulk transfer based on the session service", and Recommendation T.563, "Terminal characteristics for Group 4 facsimile apparatus".
+
+In this subclause, one part different from B.9 is defined. Another part is identical with B.9.
+
+In the coded example, "LL" means octet length of the object that contains variable length data such as coded image data.
+
+### C.7.1 User data conveyed by SUD in CDCL/RDCLP
+
+```
+APDU ::= CHOICE {  
+    [4] IMPLICIT ApplicationCapabilities }
+```
+
+```
+ApplicationCapabilities ::= SET {  
+    documentApplicationProfile [0] IMPLICIT OCTET STRING,  
+        -- '0208'H document application profile for T.503 and this annex  
+  
+    documentArchitectureClass [1] IMPLICIT OCTET STRING,  
+        -- '00'H FDA --  
+  
+    nonBasicDocCharacteristics [2] IMPLICIT NonBasicDocCharacteristics,  
+    additional-doc-characteristics [9] IMPLICIT Additional-Doc-Characteristics OPTIONAL }
+```
+
+```
+NonBasicDocCharacteristics ::= SET {  
+    page-dimensions [2] IMPLICIT SET OF Dimension-Pair OPTIONAL,  
+    ra-gr-coding-attributes [3] IMPLICIT SET OF Ra-Gr-Coding-Attribute OPTIONAL,  
+    ra-gr-presentation-features [4] IMPLICIT SET OF Ra-Gr-Presentation-Features OPTIONAL,  
+    types-of-coding [29] IMPLICIT SET OF Type-of-Coding }
+```
+
+```
+Dimension-Pair ::= SEQUENCE {  
+    horizontal [0] IMPLICIT INTEGER,  
+    vertical CHOICE {  
+        fixed [0] IMPLICIT INTEGER,  
+        variable [1] IMPLICIT INTEGER } }  
+  
+    -- North American letter = (10200,13200 fixed or variable)  
+    -- ISO B4 = (11811,16677 fixed or variable)  
+    -- ISO A3 = (14030,19840 fixed or variable)  
+    -- Japanese legal = (12141,17196 fixed or variable)  
+    -- Japanese letter = (8598,12141 fixed or variable)  
+    -- North American legal = (10200,16800 fixed or variable)  
+    -- North American ledger = (13200,20400 fixed or variable)  
+    -- ISO A4 = (9920,14030 fixed or variable)  
+    -- default value is ISO A4 = (9920,14030 fixed)  
+    -- basic value is ISO A4 = (9920,14030 fixed or variable)
+```
+
+```
+Ra-Gr-Coding-Attribute ::= CHOICE {  
+    bit-per-colour-component [4] Bit-Per-Colour-Component OPTIONAL,  
+    interleaving [5] IMPLICIT INTEGER { plane(2), stripe(3) } OPTIONAL,  
+        -- default and basic value is stripe (3).  
+        -- If stripe interleave is specified, it indicates that the terminal has the capability to  
+        -- interchange the coded image data in stripe interleave format with equal or less  
+        -- than 128 lines per stripe. In order to use more than 128 lines per stripe format,  
+        -- plane interleave shall be specified.  
+  
+    subsampling [10] IMPLICIT Subsampling OPTIONAL }
+```
+
+**Bit-Per-Colour-Component ::= CHOICE {**
+
+|                       |                              |
+|-----------------------|------------------------------|
+| <b>single-integer</b> | <b>INTEGER,</b>              |
+| <b>component-list</b> | <b>SEQUENCE OF INTEGER }</b> |
+
+*-- gray-scale 8 bits = (8,0,0)*  
+*-- colour 8 bits = (8,8,8)*  
+*-- gray-scale 12 bits = (12,0,0)*  
+*-- colour 12 bits = (12,12,12)*  
+*-- default and basic value is gray-scale 8 bits for this annex.*
+
+**Subsampling ::= OCTET STRINGS**
+
+*-- 1:1:1 ((1,1),(1,1),(1,1)) : '11 11 11'H*  
+*-- this version only supports 1:1:1 ((1,1),(1,1),(1,1)) for continuous-tone colour mode --*
+
+**Ra-Gr-Presentation-Features ::= CHOICE {**
+
+|                                 |                                                 |
+|---------------------------------|-------------------------------------------------|
+| <b>pel-transmission-density</b> | <b>[11] IMPLICIT Pel-Transmission-Density }</b> |
+|---------------------------------|-------------------------------------------------|
+
+**Pel-Transmission-Density ::= INTEGER {**
+
+|                                    |                                     |
+|------------------------------------|-------------------------------------|
+| <b>p5 (2),</b>                     | <i>-- 5 BMU (240 pels/25.4 mm)</i>  |
+| <b>p4 (3),</b>                     | <i>-- 4 BMU (300 pels/24 mm)</i>    |
+| <b>p3 (4),</b>                     | <i>-- 3 BMU (400 pels/25.4 mm)</i>  |
+| <b>p2 (5),</b>                     | <i>-- 2 BMU (600 pels/25.4 mm)</i>  |
+| <b>p1 (6),</b>                     | <i>-- 1 BMU (1200 pels/25.4 mm)</i> |
+| <b>colour/gray-scale p12 (10),</b> | <i>-- 12 BMU (100 pels/25.4 mm)</i> |
+| <b>colour/gray-scale p6 (11),</b>  | <i>-- 6 BMU (200 pels/25.4 mm)</i>  |
+| <b>colour/gray-scale p4 (13),</b>  | <i>-- 4 BMU (300 pels/25.4 mm)</i>  |
+| <b>colour/gray-scale p3 (14),</b>  | <i>-- 3 BMU (400 pels/25.4 mm)</i>  |
+| <b>colour/gray-scale p2 (15),</b>  | <i>-- 2 BMU (600 pels/25.4 mm)</i>  |
+| <b>colour/gray-scale p1 (16),</b>  | <i>-- 1 BMU (1200 pels/25.4 mm)</i> |
+| <b>(p6 (1))</b>                    | <i>-- 6 BMU (200 pels/25.4 mm)</i>  |
+
+*-- default and basic value is p6 (1)*
+
+**Type-of-Coding ::= CHOICE { [6] IMPLICIT OBJECT IDENTIFIER }**
+
+*-- T.43 {0 0 20 43 0}*  
+*-- basic value is T.43 for this annex*
+
+**Additional-Doc-Characteristics ::= SET {**
+
+|                           |                                                    |
+|---------------------------|----------------------------------------------------|
+| <b>colour-spaces-list</b> | <b>[1] IMPLICIT SET OF Colour-Spaces OPTIONAL}</b> |
+|---------------------------|----------------------------------------------------|
+
+**Colour-Space ::= SET {**
+
+|                            |                                                    |
+|----------------------------|----------------------------------------------------|
+| <b>colour-space-id</b>     | <b>[0] IMPLICIT INTEGER,</b>                       |
+| <b>colour-space-type</b>   | <b>[1] IMPLICIT Colour-Space-Type,</b>             |
+| <b>colour-data-scaling</b> | <b>[4] IMPLICIT Colour-Data-Scaling OPTIONAL }</b> |
+
+**Colour-Space-Type ::= INTEGER { cielab(4) }**
+
+**Colour-Data-Scaling ::= SET {**
+
+|                         |                                        |
+|-------------------------|----------------------------------------|
+| <b>first-component</b>  | <b>[0] IMPLICIT Scale-and-Offset,</b>  |
+| <b>second-component</b> | <b>[1] IMPLICIT Scale-and-Offset,</b>  |
+| <b>third-component</b>  | <b>[2] IMPLICIT Scale-and-Offset }</b> |
+
+**Scale-and-Offset ::= SET {**
+
+|                      |                   |
+|----------------------|-------------------|
+| <b>colour-scale</b>  | <b>[0] REAL,</b>  |
+| <b>colour-offset</b> | <b>[1] REAL }</b> |
+
+*-- default and basic values for CIELAB components are as follows:*
+
+|                            |                       |               |
+|----------------------------|-----------------------|---------------|
+|                            | <i>scale</i>          | <i>offset</i> |
+| <i>-- first-component</i>  | <i>2.55(255/100)</i>  | <i>0</i>      |
+| <i>-- second-component</i> | <i>1.5(255/170)</i>   | <i>128</i>    |
+| <i>-- third-component</i>  | <i>1.275(255/200)</i> | <i>96</i>     |
+
+Coded example (8 bits colour mode (one bit/colour, basic palettized colour and 8 bitS/colour continuous-tone image mode) using T.43 coding and CIELAB space):
+
+```
+
+A4  81  80              ApplicationCapabilities   length = 128
+    80  02  02  08          documentApplicationProfile = T.503 and this annex
+    81  01  00              documentArchitectureClass = FDA
+    A2  43                  nonBasicDocCharacteristics
+        A2  14                  page-dimensions
+            30  08                  SEQUENCE                (ISO B4 variable)
+                80  02  2F23            horizontal = 11811 BMU
+                81  02  4125            vertical = variable 16677 BMU
+            30  08                  SEQUENCE                (ISO A3 variable)
+                80  02  36CE            horizontal = 14030 BMU
+                81  02  4D80            vertical = variable 19840 BMU
+        A3  12              ra-gr-coding-attributes
+            A4  0B  30  09          bit-per-colour-component = (8,8,8) (colour 8 bits)
+                        02  01  08
+                        02  01  08
+                        02  01  08
+            8A  03  111111      subsampling = '11 11 11'H ((1,1),(1,1),(1,1))
+        A4  0F              ra-gr-presentation-features
+            8B  01  03          pel-transmission-density = 3 (300 pels/25.4 mm)
+            8B  01  04          pel-transmission-density = 4 (400 pels/25.4 mm)
+            8B  01  0B          pel-transmission-density = 11 (colour/gray-scale 200 pels/25.4 mm)
+            8B  01  0D          pel-transmission-density = 13 (colour/gray-scale 300 pels/25.4 mm)
+            8B  01  0E          pel-transmission-density = 14 (colour/gray-scale 400 pels/25.4 mm)
+        BD  06              type-of-coding
+            86  04  00 14 2B 00     = {0 0 20 43 00} (T.43)
+                                    2B is the hexadecimal notation of rec. number 43 of T.43
+    A9  3C              additional-doc-characteristics
+        A1  3A              colour-space-list
+        30  38                  colour space SET
+            80  01  01              colour-space-id = 1
+            81  01  04              colour-space-type = 4 (CIELAB)
+            A4  30                  colour-data-scaling (non-basic value case)
+                A0  0C                  first-component L* = [0, 95]
+                    A0  06                  colour-scale = 2.684 (255/95)
+                        09  04  A0  FD  2A  F2
+-- REAL length = 4 binary encoding (base = 16) exponent = -3 mantissa = '2AF2'H
+                    A1  02                  colour-offset = 0
+                        09  00
+-- REAL length = 0 (this means real value is '0')
+                    A1  0F                  second-component a* = [-85, 85]
+                        A0  06                  colour-scale = 1.5 (255/170)
+                            09  04  A0  FD  18  00
+                        A1  05                  colour-offset = 128
+                            09  03  A0  00  80
+                    A2  0F                  third-component b* = [-75, 125]
+                        A0  06                  colour-scale = 1.275 (255/200)
+                            09  04  A0  FD  14  66
+                        A1  05                  colour-offset = 96
+                            09  03  A0  00  60
+    
+```
+
+28 **ITU-T T.503 (02/2000)**
+
+### C.7.2 User data conveyed by SUD in CDS
+
+S-ACTIVITY-START-user-data ::= CHOICE {  
+[4] IMPLICIT DocumentCharacteristics }
+
+DocumentCharacteristics ::= SET {  
+documentApplicationProfile [0] IMPLICIT OCTET STRING,  
+-- '08'H for this annex  
+documentArchitectureClass [1] IMPLICIT OCTET STRING,  
+-- '00'H FDA  
+nonBasicDocCharacteristics [2] IMPLICIT NonBasicDocCharacteristics,  
+additional-doc-characteristics [9] IMPLICIT Additional-Doc-Characteristics OPTIONAL }  
+-- See. C.7.1 (except documentApplicationProfile)
+
+### C.7.3 Content Portion conveyed by CSUI/CDUI
+
+Interchange-Data-Element ::= CHOICE {  
+content-portion [3] IMPLICIT Text-Unit }
+
+Text-Unit ::= SEQUENCE {  
+content-portion-attributes Content-Portion-Attributes OPTIONAL,  
+content-information Content-Information}
+
+Content-Portion-Attributes ::= SET {  
+content-identifier-layout Content-Portion-Identifier OPTIONAL,  
+type-of-coding Type-of-Coding, -- mandatory for this annex  
+coding-attributes CHOICE {  
+raster-gr-coding-attributes [2] IMPLICIT Raster-Gr-Coding-Attributes OPTIONAL}
+
+Content-Portion-Identifier ::= [APPLICATION 0] IMPLICIT PrintableString
+
+-- only digits and space are used in the present version of the  
+-- standard; other characters are reserved for extensions.
+
+Type-of-Coding ::= CHOICE { [6] IMPLICIT OBJECT IDENTIFIER }  
+-- T.43 {0 0 20 43 00}  
+-- basic and permissible value is T.43 for this annex
+
+Raster-Gr-Coding-Attributes ::= SET {  
+number-of-pels-per-line [0] IMPLICIT INTEGER OPTIONAL,  
+number-of-discarded-pels [3] IMPLICIT INTEGER OPTIONAL,  
+bit-per-colour-component [4] Bit-Per-Colour-Component OPTIONAL,  
+interleaving [5] IMPLICIT INTEGER {plane(2), stripe(3)} OPTIONAL,  
+-- default and basic value is stripe (3) for this annex.  
+-- If stripe interleave is specified, it indicates that the terminal has the capability to  
+-- interchange the coded image data in stripe interleave format with equal or less than 128  
+-- lines per stripe.  
+-- In order to use more than 128 lines per stripe format, plane interleave shall be specified.  
+subsampling [10] IMPLICIT Subsampling OPTIONAL }
+
+Bit-Per-Colour-Component ::= CHOICE {  
+single-integer INTEGER,  
+component-list SEQUENCE OF INTEGER }  
+-- gray-scale 8 bits = (8,0,0)  
+-- colour 8 bits = (8,8,8)  
+-- gray-scale 12 bits = (12,0,0)  
+-- colour 12 bits = (12,12,12)  
+-- default and basic value is gray-scale 8 bits for this annex.
+
+Subsampling ::= OCTET STRINGS  
+-- 1:1:1 ((1,1),(1,1),(1,1)): '11 11 11'H  
+-- this version only supports 1:1:1 ((1,1),(1,1),(1,1)) for continuous-tone colour mode --
+
+Coded example 1 (lossless continuous-tone colour 8 bits/component case, plane interleave):
+
+|    |    |    |                 |                                                     |
+|----|----|----|-----------------|-----------------------------------------------------|
+| A3 | LL |    | content-portion | Text-Unit                                           |
+|    | 31 | 24 |                 | content-portion-attributes                          |
+|    | 86 | 04 | 00 14 2B 00     | type-of-coding = {0 0 20 43 00} (T.43)              |
+|    | A2 | 1C |                 | coding-attributes                                   |
+|    |    | 80 | 02 09 80        | number-of-pels-per-line = 2432 (ISO A3)             |
+|    |    | 83 | 01 2F           | number-of-discarded-pels = 47 (ISO A3)              |
+|    |    | A4 | 0B 30 09        | bit-per-colour-component = (8,8,8) (colour 8 bits)  |
+|    |    |    | 02 01 08        |                                                     |
+|    |    |    | 02 01 08        |                                                     |
+|    |    |    | 02 01 08        |                                                     |
+|    |    | A5 | 01 02           | interleaving-format = 2 (plane)                     |
+|    |    | 8A | 03 11 11 11     | subsampling = '11 11 11'H (1:1:1)                   |
+| 24 |    | 80 |                 | content-information OCTET STRING (constructed)      |
+|    |    | 04 | LL              | XXXX(T.43 string)XXXX OCTET STRING<br>(primitive)   |
+|    |    | 04 | LL              | XXXX(T.43 string)XXXX OCTET STRING<br>(primitive)   |
+|    |    | 00 | 00              | EOC                                                 |
+|    |    | 00 | 00              | EOC                                                 |
+|    |    |    |                 | (no subsampled T.43 coded 8 bits/comp. colour data) |
+
+Coded example 2 (continuous-tone colour, stripe interleave):
+
+- actual number of bit-planes are 11, 8 and 8 for L\*, a\* and b\* respectively;
+- use 12 bits/comp. mode.
+
+|    |    |    |                    |                                                                                                                    |
+|----|----|----|--------------------|--------------------------------------------------------------------------------------------------------------------|
+| A3 | LL |    | content-portion    | Text-Unit                                                                                                          |
+|    | 31 | 18 |                    | content-portion-attributes                                                                                         |
+|    | 86 | 04 | 00 14 2B 00        | type-of-coding = {0 0 20 43 00} (T.43)                                                                             |
+|    | A2 | 10 |                    | coding-attributes                                                                                                  |
+|    |    | A4 | 0B 30 09           | bit-per-colour-component = (12,12,12) (colour 12 bits)                                                             |
+|    |    |    | 02 01 0C           |                                                                                                                    |
+|    |    |    | 02 01 0C           |                                                                                                                    |
+|    |    |    | 02 01 0C           |                                                                                                                    |
+|    |    | A5 | 01 03              | interleaving-format = 3 (stripe (128 lines))                                                                       |
+| 04 | LL |    | XXXXXX(T.43)XXXXXX | OCTET STRING<br>(primitive)                                                                                        |
+|    |    |    |                    | (no subsampled T.43 coded colour data: 11, 8 and 8 bit-planes for L*, a* and b* respectively, total 27 bit-planes) |
+
+Coded example 3 (one bit per colour and stripe interleave case):
+
+|                                            |    |                                        |                                                    |
+|--------------------------------------------|----|----------------------------------------|----------------------------------------------------|
+| A3                                         | LL | content-portion Text-Unit              |                                                    |
+|                                            | 31 | 15                                     | content-portion-attributes                         |
+|                                            | 86 | 04                                     | 00 14 2B 00 type-of-coding = {0 0 20 43 00} (T.43) |
+|                                            | A2 | OD                                     | coding-attributes                                  |
+|                                            |    | A4                                     | 0B 30 09 bit-per-colour-component = (8,8,8)        |
+|                                            |    |                                        | 02 01 08 (8 bits per component colour mode)        |
+|                                            |    |                                        | 02 01 08                                           |
+|                                            |    |                                        | 02 01 08                                           |
+| 04                                         | LL | XXXXXX(T.43 string)XXXXXX OCTET STRING |                                                    |
+|                                            |    | (primitive)                            |                                                    |
+| (one bit per colour image T.43 coded data) |    |                                        |                                                    |
+
+Coded example 4 (extended palettized colour image, stripe interleave):
+
+- number of palette colour table entries is 200, then number of bit-planes is 8;
+- use 12 bits/comp. precision palette table.
+
+|                                                                                                               |    |                                        |                                                                 |
+|---------------------------------------------------------------------------------------------------------------|----|----------------------------------------|-----------------------------------------------------------------|
+| A3                                                                                                            | LL | content-portion Text-Unit              |                                                                 |
+|                                                                                                               | 31 | 18                                     | content-portion-attributes                                      |
+|                                                                                                               | 86 | 04                                     | 00 14 2B 00 type-of-coding = {0 0 20 43 00} (T.43)              |
+|                                                                                                               | A2 | 10                                     | coding-attributes                                               |
+|                                                                                                               |    | A4                                     | 0B 30 09 bit-per-colour-component = (12,12,12) (colour 12 bits) |
+|                                                                                                               |    |                                        | 02 01 0C                                                        |
+|                                                                                                               |    |                                        | 02 01 0C                                                        |
+|                                                                                                               |    |                                        | 02 01 0C                                                        |
+|                                                                                                               |    | A5                                     | 01 03 interleaving-format = 3 (stripe (128 lines))              |
+| 04                                                                                                            | LL | XXXXXX(T.43 string)XXXXXX OCTET STRING |                                                                 |
+|                                                                                                               |    | (primitive)                            |                                                                 |
+| (T.43 coded 8 bit-planes palettized colour image data with 200 entries 12 bits/comp. precision palette table) |    |                                        |                                                                 |
+
+
+
+# ITU-T RECOMMENDATIONS SERIES
+
+|                 |                                                                                                                                |
+|-----------------|--------------------------------------------------------------------------------------------------------------------------------|
+| Series A        | Organization of the work of the ITU-T                                                                                          |
+| Series B        | Means of expression: definitions, symbols, classification                                                                      |
+| Series C        | General telecommunication statistics                                                                                           |
+| Series D        | General tariff principles                                                                                                      |
+| Series E        | Overall network operation, telephone service, service operation and human factors                                              |
+| Series F        | Non-telephone telecommunication services                                                                                       |
+| Series G        | Transmission systems and media, digital systems and networks                                                                   |
+| Series H        | Audiovisual and multimedia systems                                                                                             |
+| Series I        | Integrated services digital network                                                                                            |
+| Series J        | Transmission of television, sound programme and other multimedia signals                                                       |
+| Series K        | Protection against interference                                                                                                |
+| Series L        | Construction, installation and protection of cables and other elements of outside plant                                        |
+| Series M        | TMN and network maintenance: international transmission systems, telephone circuits, telegraphy, facsimile and leased circuits |
+| Series N        | Maintenance: international sound programme and television transmission circuits                                                |
+| Series O        | Specifications of measuring equipment                                                                                          |
+| Series P        | Telephone transmission quality, telephone installations, local line networks                                                   |
+| Series Q        | Switching and signalling                                                                                                       |
+| Series R        | Telegraph transmission                                                                                                         |
+| Series S        | Telegraph services terminal equipment                                                                                          |
+| <b>Series T</b> | <b>Terminals for telematic services</b>                                                                                        |
+| Series U        | Telegraph switching                                                                                                            |
+| Series V        | Data communication over the telephone network                                                                                  |
+| Series X        | Data networks and open system communications                                                                                   |
+| Series Y        | Global information infrastructure and Internet protocol aspects                                                                |
+| Series Z        | Languages and general software aspects for telecommunication systems                                                           |
\ No newline at end of file
diff --git a/marked/T/T-REC-T.506-199308-I_PDF-E/0b7849dae424b0dd33e6386d2384643a_img.jpg b/marked/T/T-REC-T.506-199308-I_PDF-E/0b7849dae424b0dd33e6386d2384643a_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..568695f1f35008849b50f07f9d3e9d8a81b4d695
--- /dev/null
+++ b/marked/T/T-REC-T.506-199308-I_PDF-E/0b7849dae424b0dd33e6386d2384643a_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:a7fa0d10203743840a0e75261bde2d174b7e3aa7c12b08b2da9540b6ebdb7922
+size 76490
diff --git a/marked/T/T-REC-T.506-199308-I_PDF-E/1142ba0197b158bb198186fe8baccc32_img.jpg b/marked/T/T-REC-T.506-199308-I_PDF-E/1142ba0197b158bb198186fe8baccc32_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..1bfbc3d50c490edd9789c490cfa811fdbae17685
--- /dev/null
+++ b/marked/T/T-REC-T.506-199308-I_PDF-E/1142ba0197b158bb198186fe8baccc32_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:87aeb082d9bbfba9ae4bfe8fb94f22216b794d0c9d91a3476b59c8c8138435ef
+size 50688
diff --git a/marked/T/T-REC-T.506-199308-I_PDF-E/140bd031d724324269168296afd1e04d_img.jpg b/marked/T/T-REC-T.506-199308-I_PDF-E/140bd031d724324269168296afd1e04d_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..740fd841dcc7585954a2d35a2467a3b06b2cd095
--- /dev/null
+++ b/marked/T/T-REC-T.506-199308-I_PDF-E/140bd031d724324269168296afd1e04d_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:b1a52c205fa6acb8bcfe99766c0926830632207d2950147fde09efd1c3496093
+size 27917
diff --git a/marked/T/T-REC-T.506-199308-I_PDF-E/18291be12b470a557e8c9f3a74e021be_img.jpg b/marked/T/T-REC-T.506-199308-I_PDF-E/18291be12b470a557e8c9f3a74e021be_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..9e9ebefaa2a99595d29496d1873f6883ad49a36a
--- /dev/null
+++ b/marked/T/T-REC-T.506-199308-I_PDF-E/18291be12b470a557e8c9f3a74e021be_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:d8e7bd260f843b299d8d1650dc823afcefb72a39d3e08fc8614e341b86efd73c
+size 85981
diff --git a/marked/T/T-REC-T.506-199308-I_PDF-E/1ab49904e6a60be337d5b75cb7cc8ab7_img.jpg b/marked/T/T-REC-T.506-199308-I_PDF-E/1ab49904e6a60be337d5b75cb7cc8ab7_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..c4463dc6bf3b0fb5bd50223cd24cc412e1a64b4f
--- /dev/null
+++ b/marked/T/T-REC-T.506-199308-I_PDF-E/1ab49904e6a60be337d5b75cb7cc8ab7_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:e005e7562ee21f77216ea5dc60ad25fe05a7f0e681ff690132043610912f913e
+size 84421
diff --git a/marked/T/T-REC-T.506-199308-I_PDF-E/1e5a58dcaf0936bf18dc3dd0d9cd43ff_img.jpg b/marked/T/T-REC-T.506-199308-I_PDF-E/1e5a58dcaf0936bf18dc3dd0d9cd43ff_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..038768ca8b149d65283098cec867623f01fd691a
--- /dev/null
+++ b/marked/T/T-REC-T.506-199308-I_PDF-E/1e5a58dcaf0936bf18dc3dd0d9cd43ff_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:68e4a4726b63e5822e89a4bde29aeac52c40189eb7eb045cf5deaefa124fe5f5
+size 22858
diff --git a/marked/T/T-REC-T.506-199308-I_PDF-E/21ea5add6a61cc951b5c43ddffefb3ff_img.jpg b/marked/T/T-REC-T.506-199308-I_PDF-E/21ea5add6a61cc951b5c43ddffefb3ff_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..3aaf91377145daf3a1a8255731153dae108f037f
--- /dev/null
+++ b/marked/T/T-REC-T.506-199308-I_PDF-E/21ea5add6a61cc951b5c43ddffefb3ff_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:de530719ea7d86938db8faeeae5a5d2aa4512cd8940d1e75e37a5aad989ea198
+size 19152
diff --git a/marked/T/T-REC-T.506-199308-I_PDF-E/2dd10dd89365981b6b6154de6390a602_img.jpg b/marked/T/T-REC-T.506-199308-I_PDF-E/2dd10dd89365981b6b6154de6390a602_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..302cd9209604b34345984d5569fb46ca362b335b
--- /dev/null
+++ b/marked/T/T-REC-T.506-199308-I_PDF-E/2dd10dd89365981b6b6154de6390a602_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:4f2d8e0e2c1245033a4b3447ec2fb27a8aaaef30a716cd5a9bef18139e0e4dd5
+size 28133
diff --git a/marked/T/T-REC-T.506-199308-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/T/T-REC-T.506-199308-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..9bb822ad16dcada9da5b072d984715d258e56bf1
--- /dev/null
+++ b/marked/T/T-REC-T.506-199308-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:476abc418bd0ea4d4e1facebe49907b709aa48db1a1a0e763699f1c05c2fa76f
+size 8331
diff --git a/marked/T/T-REC-T.506-199308-I_PDF-E/3481cde1adf61b0452dd6489dada6d6a_img.jpg b/marked/T/T-REC-T.506-199308-I_PDF-E/3481cde1adf61b0452dd6489dada6d6a_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..cb76f317c25014b449307f6affdf6c01122ec611
--- /dev/null
+++ b/marked/T/T-REC-T.506-199308-I_PDF-E/3481cde1adf61b0452dd6489dada6d6a_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:416cd35f466e7c211946bf8ddd54a5bd1ba00743284cc98c649cf8235733ec17
+size 48300
diff --git a/marked/T/T-REC-T.506-199308-I_PDF-E/38d82ffe820e339811b396206f40a201_img.jpg b/marked/T/T-REC-T.506-199308-I_PDF-E/38d82ffe820e339811b396206f40a201_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..a9982a2341c4a65fd715af77249a006c621911c8
--- /dev/null
+++ b/marked/T/T-REC-T.506-199308-I_PDF-E/38d82ffe820e339811b396206f40a201_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:a605214257242b1bb59087bf16dffde4faa2a24828e470222cd2b6c151a458b5
+size 24753
diff --git a/marked/T/T-REC-T.506-199308-I_PDF-E/3a006a7c9c9934695f0fc731344eff8a_img.jpg b/marked/T/T-REC-T.506-199308-I_PDF-E/3a006a7c9c9934695f0fc731344eff8a_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..86fdf83ced01b5cb76556ac03752b6bc7efcc410
--- /dev/null
+++ b/marked/T/T-REC-T.506-199308-I_PDF-E/3a006a7c9c9934695f0fc731344eff8a_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:55ff3712e9ba7fca185d380416299fee84e86aa78ba5401cdbe076af388eb46a
+size 43659
diff --git a/marked/T/T-REC-T.506-199308-I_PDF-E/401f020d9ab5904f584424eabb596d2c_img.jpg b/marked/T/T-REC-T.506-199308-I_PDF-E/401f020d9ab5904f584424eabb596d2c_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..d6aca096bbf4506c9cda2999f3b6141d82ad0a60
--- /dev/null
+++ b/marked/T/T-REC-T.506-199308-I_PDF-E/401f020d9ab5904f584424eabb596d2c_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:acd5b616444d5442e204b946927a77fdb5b7256f5df8e3cfea842cdfa95f2804
+size 55429
diff --git a/marked/T/T-REC-T.506-199308-I_PDF-E/4162c218fc7881cd90fc9574e07d2327_img.jpg b/marked/T/T-REC-T.506-199308-I_PDF-E/4162c218fc7881cd90fc9574e07d2327_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..e5816ff82cb30f80a601b90c0669e831ad4472fc
--- /dev/null
+++ b/marked/T/T-REC-T.506-199308-I_PDF-E/4162c218fc7881cd90fc9574e07d2327_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:da65ce7c468934906a5ee0eda6a5c8edd69e42efdf47ea46b421b531a4cfd549
+size 71937
diff --git a/marked/T/T-REC-T.506-199308-I_PDF-E/4260aa4a7ece77c411597094c9d197bd_img.jpg b/marked/T/T-REC-T.506-199308-I_PDF-E/4260aa4a7ece77c411597094c9d197bd_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..5baa052e352ecb430d37c25966461693aaccd10e
--- /dev/null
+++ b/marked/T/T-REC-T.506-199308-I_PDF-E/4260aa4a7ece77c411597094c9d197bd_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:4d4e5120242b4c7909f1826b9826a377460b4059959d02bff944417ad2cffac9
+size 43265
diff --git a/marked/T/T-REC-T.506-199308-I_PDF-E/487c58c79e44e6cf98b6368b6667b9c6_img.jpg b/marked/T/T-REC-T.506-199308-I_PDF-E/487c58c79e44e6cf98b6368b6667b9c6_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..4caa6a35f1f8b7a75b2d720e0fecf412bd63f504
--- /dev/null
+++ b/marked/T/T-REC-T.506-199308-I_PDF-E/487c58c79e44e6cf98b6368b6667b9c6_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:5449e9bfa6e6678c3a9dfbb10674e13cf84790ed4a2f72a554ce888f31081e6e
+size 32745
diff --git a/marked/T/T-REC-T.506-199308-I_PDF-E/56a42b3c4e1a79a71c8f27aa03b78b84_img.jpg b/marked/T/T-REC-T.506-199308-I_PDF-E/56a42b3c4e1a79a71c8f27aa03b78b84_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..aff5ee191a209fe7471c48ce66a0c333fbcc2bb6
--- /dev/null
+++ b/marked/T/T-REC-T.506-199308-I_PDF-E/56a42b3c4e1a79a71c8f27aa03b78b84_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:78036bf7173cf86517ccba8f6cb5789ec3ebe7fc8d8784ef7245f92d02adf5c2
+size 24337
diff --git a/marked/T/T-REC-T.506-199308-I_PDF-E/592f13acca3e6d5152dd4489f030d004_img.jpg b/marked/T/T-REC-T.506-199308-I_PDF-E/592f13acca3e6d5152dd4489f030d004_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..67b5e24fc7b8dda2aa2817dfb3daa90386fb5b46
--- /dev/null
+++ b/marked/T/T-REC-T.506-199308-I_PDF-E/592f13acca3e6d5152dd4489f030d004_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:b65fde557bfdff3ac2238def83303a8975870cee45147989c8ecd282ae81d020
+size 32626
diff --git a/marked/T/T-REC-T.506-199308-I_PDF-E/5eb69662cc4fa7d0d49b4eb22951c204_img.jpg b/marked/T/T-REC-T.506-199308-I_PDF-E/5eb69662cc4fa7d0d49b4eb22951c204_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..5bdb051e0777fe4faebc017e231e30a59d8a17da
--- /dev/null
+++ b/marked/T/T-REC-T.506-199308-I_PDF-E/5eb69662cc4fa7d0d49b4eb22951c204_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:abc38d002a0995f79926c4811f12d4baea1b0ccc0462e0d326fd8e95475b8785
+size 76374
diff --git a/marked/T/T-REC-T.506-199308-I_PDF-E/701bc79e78b382bcfd3ba85597dbb9c3_img.jpg b/marked/T/T-REC-T.506-199308-I_PDF-E/701bc79e78b382bcfd3ba85597dbb9c3_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..615f71fbe66c0e35fdc4c45cd40a9ba9c3f5b4b2
--- /dev/null
+++ b/marked/T/T-REC-T.506-199308-I_PDF-E/701bc79e78b382bcfd3ba85597dbb9c3_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:3965582462c2e0c63ede57d68a5d319a5a23fde23c6e6d52d55fe976c9e8eaac
+size 71225
diff --git a/marked/T/T-REC-T.506-199308-I_PDF-E/77959075c823bb5169480d7b8ff82a63_img.jpg b/marked/T/T-REC-T.506-199308-I_PDF-E/77959075c823bb5169480d7b8ff82a63_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..86dcc2b9ea494d9419ef533d6b546315cca345ee
--- /dev/null
+++ b/marked/T/T-REC-T.506-199308-I_PDF-E/77959075c823bb5169480d7b8ff82a63_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:309cc2057417ec13f41f7cb15f2cf5471320ecaa6f8ba5370df22bd8051375c4
+size 116608
diff --git a/marked/T/T-REC-T.506-199308-I_PDF-E/7b7596fb5ef925025341a9aacb6f2be7_img.jpg b/marked/T/T-REC-T.506-199308-I_PDF-E/7b7596fb5ef925025341a9aacb6f2be7_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..a4c3b1edc7f00af28d790c1e24dd07f8b8be86de
--- /dev/null
+++ b/marked/T/T-REC-T.506-199308-I_PDF-E/7b7596fb5ef925025341a9aacb6f2be7_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:49c580f6cb7f754128152be1399bab86abfffdde9c132e54864f1fd7f9cb28a1
+size 31103
diff --git a/marked/T/T-REC-T.506-199308-I_PDF-E/8605b43090d582ea5046e1804178a7d8_img.jpg b/marked/T/T-REC-T.506-199308-I_PDF-E/8605b43090d582ea5046e1804178a7d8_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..b7cfb52af4792ac97533c6f4396d29018b587e15
--- /dev/null
+++ b/marked/T/T-REC-T.506-199308-I_PDF-E/8605b43090d582ea5046e1804178a7d8_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:2bc2ffe765c7f39e0c8a442a8233226155743bb4c7688646dc989a226ba4c075
+size 56351
diff --git a/marked/T/T-REC-T.506-199308-I_PDF-E/8ba270d9a35a905e16a9b78e6b3ad2b8_img.jpg b/marked/T/T-REC-T.506-199308-I_PDF-E/8ba270d9a35a905e16a9b78e6b3ad2b8_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..cbbb9becf520fd7acac9dfa3ebfe02587637d63a
--- /dev/null
+++ b/marked/T/T-REC-T.506-199308-I_PDF-E/8ba270d9a35a905e16a9b78e6b3ad2b8_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:d451883e9309ce08fffdb5c75269aa554fc924d4dcb618ff85e13cb50c98a73d
+size 21980
diff --git a/marked/T/T-REC-T.506-199308-I_PDF-E/8d66c9c295023a1380f9986d3663bb1e_img.jpg b/marked/T/T-REC-T.506-199308-I_PDF-E/8d66c9c295023a1380f9986d3663bb1e_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..b7f7952a0028cc963eed207fc5e39aba9e40930f
--- /dev/null
+++ b/marked/T/T-REC-T.506-199308-I_PDF-E/8d66c9c295023a1380f9986d3663bb1e_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:949243b2e5917e1ccc831270570940758a25701081a088782940bb8ff6d02bdf
+size 69696
diff --git a/marked/T/T-REC-T.506-199308-I_PDF-E/909726977de6efd2d4df015198a2907b_img.jpg b/marked/T/T-REC-T.506-199308-I_PDF-E/909726977de6efd2d4df015198a2907b_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..56bec5b698559774af793934426e629f3c62007e
--- /dev/null
+++ b/marked/T/T-REC-T.506-199308-I_PDF-E/909726977de6efd2d4df015198a2907b_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:c6027ba109bac1701a55c4ce16e2086909deb96ea39823cfe2f34350cb2509ad
+size 21782
diff --git a/marked/T/T-REC-T.506-199308-I_PDF-E/921458d4fc1b778c2450592ac9745b48_img.jpg b/marked/T/T-REC-T.506-199308-I_PDF-E/921458d4fc1b778c2450592ac9745b48_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..40497d5fa0919698d849525bf2f367894c42c17e
--- /dev/null
+++ b/marked/T/T-REC-T.506-199308-I_PDF-E/921458d4fc1b778c2450592ac9745b48_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:305a0300d673162257b13afdbc7e9df292966ced66b71a373eccccc245d06119
+size 33373
diff --git a/marked/T/T-REC-T.506-199308-I_PDF-E/9a14684f8ae1345c6efea6f5994c730c_img.jpg b/marked/T/T-REC-T.506-199308-I_PDF-E/9a14684f8ae1345c6efea6f5994c730c_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..83062d2a753db7780d600b825a24805dd7e3bed8
--- /dev/null
+++ b/marked/T/T-REC-T.506-199308-I_PDF-E/9a14684f8ae1345c6efea6f5994c730c_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:8dc5c4bbb5dc562d1e52b30f4c00e87ffc38e4c42285f644223f070acb16da2d
+size 81595
diff --git a/marked/T/T-REC-T.506-199308-I_PDF-E/9a5927586a691c4908aa2cf98bd47ebb_img.jpg b/marked/T/T-REC-T.506-199308-I_PDF-E/9a5927586a691c4908aa2cf98bd47ebb_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..27fbff8dc971898dfc06d9b14d0b01d883efc3ac
--- /dev/null
+++ b/marked/T/T-REC-T.506-199308-I_PDF-E/9a5927586a691c4908aa2cf98bd47ebb_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:891113a2d0f8218c0749435d56d7c26857e30a4e6b3fcaf94b72291bde81184d
+size 73764
diff --git a/marked/T/T-REC-T.506-199308-I_PDF-E/9c80cf99954eb0142f694456d39fae4b_img.jpg b/marked/T/T-REC-T.506-199308-I_PDF-E/9c80cf99954eb0142f694456d39fae4b_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..1ced401dd6830d3fd9be99e0ef495724a5584c88
--- /dev/null
+++ b/marked/T/T-REC-T.506-199308-I_PDF-E/9c80cf99954eb0142f694456d39fae4b_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:df1995ab229b4ee070fc59dfd0e129e64dfea33858ad198aaa5775eb54e97e63
+size 19178
diff --git a/marked/T/T-REC-T.506-199308-I_PDF-E/9dc9f41d7d76c1add4b190d348cb1533_img.jpg b/marked/T/T-REC-T.506-199308-I_PDF-E/9dc9f41d7d76c1add4b190d348cb1533_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..9f8f86d5959664d2a576325affeb833b0184349f
--- /dev/null
+++ b/marked/T/T-REC-T.506-199308-I_PDF-E/9dc9f41d7d76c1add4b190d348cb1533_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:de3f0f9b91a6d07ed1b1772b9280cecbc718b189260f85d20ca494f82f498df8
+size 50137
diff --git a/marked/T/T-REC-T.506-199308-I_PDF-E/9faa3512b2ff7973283e76192e91bf65_img.jpg b/marked/T/T-REC-T.506-199308-I_PDF-E/9faa3512b2ff7973283e76192e91bf65_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..58aadd9e8de66850773da027616a3e3e34bdc035
--- /dev/null
+++ b/marked/T/T-REC-T.506-199308-I_PDF-E/9faa3512b2ff7973283e76192e91bf65_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:e9b5f19cbfaecaf33146659d03ec04b42e242a9d397794960eadfe2f8ce5651f
+size 23605
diff --git a/marked/T/T-REC-T.506-199308-I_PDF-E/a37adbbe12ec735a20ead2466363d07a_img.jpg b/marked/T/T-REC-T.506-199308-I_PDF-E/a37adbbe12ec735a20ead2466363d07a_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..0a00c34481a893b5198263e3c5687f89f05ba980
--- /dev/null
+++ b/marked/T/T-REC-T.506-199308-I_PDF-E/a37adbbe12ec735a20ead2466363d07a_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:39f2f419719c58226ec06f08c1a9782d1ba05c7590238db16984ddb4582901cd
+size 29797
diff --git a/marked/T/T-REC-T.506-199308-I_PDF-E/a5b9392ecb96e6b5e0b4ee0664210f72_img.jpg b/marked/T/T-REC-T.506-199308-I_PDF-E/a5b9392ecb96e6b5e0b4ee0664210f72_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..cf8ebed1d622ad0686dbc9f6ed2214933d34e8de
--- /dev/null
+++ b/marked/T/T-REC-T.506-199308-I_PDF-E/a5b9392ecb96e6b5e0b4ee0664210f72_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:912d7243d681ddb8c006ba13ffaca11bf5c060b7efa23e4d54324fadbda35af4
+size 48205
diff --git a/marked/T/T-REC-T.506-199308-I_PDF-E/ae375ead8aa673286b534e079e9a8533_img.jpg b/marked/T/T-REC-T.506-199308-I_PDF-E/ae375ead8aa673286b534e079e9a8533_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..89882b18a667f1b70ca37ff1d3e8303fe7cf675c
--- /dev/null
+++ b/marked/T/T-REC-T.506-199308-I_PDF-E/ae375ead8aa673286b534e079e9a8533_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:60f1a96c580a8334f5e68da8f2343e89f6dcd0ef7885268abd3b1834a89eaf0c
+size 42234
diff --git a/marked/T/T-REC-T.506-199308-I_PDF-E/ca86f53f9735fe98b6c6003d1b759f64_img.jpg b/marked/T/T-REC-T.506-199308-I_PDF-E/ca86f53f9735fe98b6c6003d1b759f64_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..6dfd6293d31033531ff5f2cc0482a99ac246c7c1
--- /dev/null
+++ b/marked/T/T-REC-T.506-199308-I_PDF-E/ca86f53f9735fe98b6c6003d1b759f64_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:542a1105cb0d071b5003826c7a432b1087f0ffc536bcb091b54cad87f4098766
+size 24733
diff --git a/marked/T/T-REC-T.506-199308-I_PDF-E/cc3d87694102054bcd694ae696bc41fa_img.jpg b/marked/T/T-REC-T.506-199308-I_PDF-E/cc3d87694102054bcd694ae696bc41fa_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..fe37cf2081abb3b07d262d6850115a795966160e
--- /dev/null
+++ b/marked/T/T-REC-T.506-199308-I_PDF-E/cc3d87694102054bcd694ae696bc41fa_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:c2b2a3cffe9ba9e11a32d54707b799365ee7f1a86dd3429e69128f9ce1f50f0e
+size 29324
diff --git a/marked/T/T-REC-T.506-199308-I_PDF-E/cf36ccd7ff79531e18e5b0ab1f0c46d4_img.jpg b/marked/T/T-REC-T.506-199308-I_PDF-E/cf36ccd7ff79531e18e5b0ab1f0c46d4_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..da96c899a61c222e2c91c411c2ea44fc29e82737
--- /dev/null
+++ b/marked/T/T-REC-T.506-199308-I_PDF-E/cf36ccd7ff79531e18e5b0ab1f0c46d4_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:5abf8e2294ffa5bd247ef39104799411069b3e03116c9218c2c08b8639d61b5e
+size 92160
diff --git a/marked/T/T-REC-T.506-199308-I_PDF-E/d2417b04116c354deccb25d98a84a0fb_img.jpg b/marked/T/T-REC-T.506-199308-I_PDF-E/d2417b04116c354deccb25d98a84a0fb_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..26b879852b525febbb9f1fddbe9bb1267dfef0de
--- /dev/null
+++ b/marked/T/T-REC-T.506-199308-I_PDF-E/d2417b04116c354deccb25d98a84a0fb_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:aa7905ad11080cde4f07ab157b2eb14f2c6bb5b78baec6a15aad1adc30ab1fd0
+size 12451
diff --git a/marked/T/T-REC-T.506-199308-I_PDF-E/d79de2dd022d74722a84f1b2ffce691c_img.jpg b/marked/T/T-REC-T.506-199308-I_PDF-E/d79de2dd022d74722a84f1b2ffce691c_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..5cc5fc5fffaa07209dc66bfe93a1ab757ff608a0
--- /dev/null
+++ b/marked/T/T-REC-T.506-199308-I_PDF-E/d79de2dd022d74722a84f1b2ffce691c_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:ba0801cadeefef6849af163f1c0709bd1ff02e1a6e4189783b76323cbe16aaf2
+size 24504
diff --git a/marked/T/T-REC-T.506-199308-I_PDF-E/d9ea7e6c55ac790700d27c96ba7f66a3_img.jpg b/marked/T/T-REC-T.506-199308-I_PDF-E/d9ea7e6c55ac790700d27c96ba7f66a3_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..a83532f2948021bf25805967679177377ced689d
--- /dev/null
+++ b/marked/T/T-REC-T.506-199308-I_PDF-E/d9ea7e6c55ac790700d27c96ba7f66a3_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:9fc50484a523d953b5a76a88a93d38f6d9cb7c6a670dd98fd01f46d94b107c3b
+size 29248
diff --git a/marked/T/T-REC-T.506-199308-I_PDF-E/da06747b80ea0d71593cbbd4c2ea89aa_img.jpg b/marked/T/T-REC-T.506-199308-I_PDF-E/da06747b80ea0d71593cbbd4c2ea89aa_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..8100b308cc0bc22dad381078434d67b4111b8fbf
--- /dev/null
+++ b/marked/T/T-REC-T.506-199308-I_PDF-E/da06747b80ea0d71593cbbd4c2ea89aa_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:8c72cf05484b58eb79fb7d6055c99aa59308ce33cce4e291e11b23b93c291cb8
+size 34086
diff --git a/marked/T/T-REC-T.506-199308-I_PDF-E/e451401f8fa77b466f401d5fce15b26c_img.jpg b/marked/T/T-REC-T.506-199308-I_PDF-E/e451401f8fa77b466f401d5fce15b26c_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..96efd6111ece701bb5a65f0335448dc6f6e3e443
--- /dev/null
+++ b/marked/T/T-REC-T.506-199308-I_PDF-E/e451401f8fa77b466f401d5fce15b26c_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:68956d29615e7451006e1ac4eaa7f9b2b93b770b5d1df921a8d4b0bb31f2f100
+size 53935
diff --git a/marked/T/T-REC-T.506-199308-I_PDF-E/f57c7b37d7a05a99618104f390089f03_img.jpg b/marked/T/T-REC-T.506-199308-I_PDF-E/f57c7b37d7a05a99618104f390089f03_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..8d345abf46c5008f07981cd8c1c4b3f9eaf4b808
--- /dev/null
+++ b/marked/T/T-REC-T.506-199308-I_PDF-E/f57c7b37d7a05a99618104f390089f03_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:a62ead861526ae05668f5f7d8e88f1e9d8d787236d58294ed0e44c2daa1acde5
+size 49994
diff --git a/marked/T/T-REC-T.51-199209-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/T/T-REC-T.51-199209-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..16a8c37767b44bbf56153e483e234b83bee1e94e
--- /dev/null
+++ b/marked/T/T-REC-T.51-199209-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:c502a5874d039a394de26084080e75db98a1990793a2137e752c6e5738467aa8
+size 8367
diff --git a/marked/T/T-REC-T.51-199209-I_PDF-E/33ed1f9b27c7c21c797aa928b0f06851_img.jpg b/marked/T/T-REC-T.51-199209-I_PDF-E/33ed1f9b27c7c21c797aa928b0f06851_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..1c7fd2f3780028e58a88efebf109080032921f09
--- /dev/null
+++ b/marked/T/T-REC-T.51-199209-I_PDF-E/33ed1f9b27c7c21c797aa928b0f06851_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:67481ca43fb86ed6491aa55a99ce0b0940e3cae333288c2434d11ac702daa23f
+size 116035
diff --git a/marked/T/T-REC-T.51-199209-I_PDF-E/6ed175c791b5e156d9c98a8dbcc3318c_img.jpg b/marked/T/T-REC-T.51-199209-I_PDF-E/6ed175c791b5e156d9c98a8dbcc3318c_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..91d9a5110a496d8d10b9f1e9d846b36d12052520
--- /dev/null
+++ b/marked/T/T-REC-T.51-199209-I_PDF-E/6ed175c791b5e156d9c98a8dbcc3318c_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:b32678102bb114a24514c3ee31dbb68e1e754d9e175b55ccee64ac38df0e0268
+size 6044
diff --git a/marked/T/T-REC-T.51-199209-I_PDF-E/ebff22fb5dd6f50a90e44dca0f82f285_img.jpg b/marked/T/T-REC-T.51-199209-I_PDF-E/ebff22fb5dd6f50a90e44dca0f82f285_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..66184f5bc8801b223b1d7e79765bf9fa4a8b6873
--- /dev/null
+++ b/marked/T/T-REC-T.51-199209-I_PDF-E/ebff22fb5dd6f50a90e44dca0f82f285_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:9e20fad8e1cccdf0f90f08dbb609c9fce70b5a2fc5d1a13b74528a71ec67f906
+size 154758
diff --git a/marked/T/T-REC-T.51-199209-I_PDF-E/f4fdd410cdb84df81274da55721e56fb_img.jpg b/marked/T/T-REC-T.51-199209-I_PDF-E/f4fdd410cdb84df81274da55721e56fb_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..1989eb76dcef495b01a2af450de6592fbe430dad
--- /dev/null
+++ b/marked/T/T-REC-T.51-199209-I_PDF-E/f4fdd410cdb84df81274da55721e56fb_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:4f3273f30395f5309ac8a7af95200bae7cc6785bc57f9cb0f9a23925ee2e1128
+size 148835
diff --git a/marked/T/T-REC-T.51-199209-I_PDF-E/raw.md b/marked/T/T-REC-T.51-199209-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..b5bfa0f41a178393464e4f6fdf5870ed407b60eb
--- /dev/null
+++ b/marked/T/T-REC-T.51-199209-I_PDF-E/raw.md
@@ -0,0 +1,1087 @@
+
+
+![ITU logo: a globe with the letters ITU inside, and a lightning bolt passing through it.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg)
+
+ITU logo: a globe with the letters ITU inside, and a lightning bolt passing through it.
+
+INTERNATIONAL TELECOMMUNICATION UNION
+
+# CCITT
+
+THE INTERNATIONAL  
+TELEGRAPH AND TELEPHONE  
+CONSULTATIVE COMMITTEE
+
+## T.51
+
+(09/92)
+
+**TERMINAL EQUIPMENT AND PROTOCOLS  
+FOR TELEMATIC SERVICES**
+
+---
+
+**LATIN BASED CODED CHARACTER SETS  
+FOR TELEMATIC SERVICES**
+
+![CCITT logo: a globe with the letters CITT inside, and a lightning bolt passing through it.](6ed175c791b5e156d9c98a8dbcc3318c_img.jpg)
+
+CCITT logo: a globe with the letters CITT inside, and a lightning bolt passing through it.
+
+**Recommendation T.51**
+
+---
+
+# FOREWORD
+
+The CCITT (the International Telegraph and Telephone Consultative Committee) is a permanent organ of the International Telecommunication Union (ITU). CCITT is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis.
+
+The Plenary Assembly of CCITT which meets every four years, establishes the topics for study and approves Recommendations prepared by its Study Groups. The approval of Recommendations by the members of CCITT between Plenary Assemblies is covered by the procedure laid down in CCITT Resolution No. 2 (Melbourne, 1988).
+
+Recommendation revised T.51 was revised by Study Group VIII and was approved under the Resolution No. 2 procedure on the 18 September 1992.
+
+## --- CCITT NOTES
+
+- 1) In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized private operating agency.
+- 2) A list of abbreviations used in this Recommendation can be found in Annex C.
+
+## Recommendation T.51
+
+# LATIN BASED CODED CHARACTER SETS FOR TELEMATIC SERVICES
+
+*(Malaga-Torremolinos, 1984; Amended at Melbourne 1988;  
+revised 1992)*
+
+## 1 Scope
+
+### 1.1 The CCITT,
+
+*considering*
+
+(a) the increasing interdependence of the various CCITT character sets and coding schemes in various telematic services;
+
+(b) the introduction of new facilities such as code conversion and interworking between various telematic services;
+
+(c) the advantage of having a single unified repertoire and coding of Latin based character set in a Recommendation to act as a reference for the telematic services;
+
+(d) that Recommendations T.61 and T.100/T.101 define the character coding systems for teletex and videotex;
+
+(e) that Recommendation T.50 specifies the International Reference Version (IRV) of the 7-bit coded character set,
+
+*provides the following Recommendation as a reference document*
+
+towards which the Latin based portion of the coded character sets of telematic services should migrate and from which coded character subsets and elements of code extension mechanisms can be derived for individual telematic services.
+
+1.2 This Recommendation specifies a primary set and a 96-character supplementary set of graphic characters. When various telematic services restrict their primary and supplementary sets to be respective subsets of those given in this Recommendation, it will be ensured that no code position in any of the specified code tables is assigned more than one meaning within different telematic services. 94-character subsets of the supplementary code table can be found in Recommendations of specific telematic services, i.e., in Recommendations T.61 and T.101.
+
+1.3 This Recommendation gives the escape sequences for designating the primary and supplementary sets of graphic characters, to be used according to the code extension techniques specified.
+
+1.4 Non-Latin based character sets are to be dealt with in Recommendation T.52.
+
+1.5 This Recommendation describes those code extension mechanisms that are relevant to existing telematic services. Additional mechanisms will be included in this Recommendation as the need for such is identified for one or more telematic services. The purpose of this Recommendation is to include an up-to-coding systems in various telematic services.
+
+1.6 In this Recommendation 7-bit code tables are described which can be used either in a 7-bit or in an 8-bit environment, with applicable code extension mechanisms that are given in other Recommendations specific to given telematic services.
+
+1.7 This Recommendation gives a unified superset of the repertoire of Latin based alphanumeric characters (see Annex A).
+
+1.8 This Recommendation gives a table of character and control sets used in CCITT telematic services (see Annex B).
+
+1.9 There is no conformance clause in this Recommendation specifying the mandatory and optional subsets of code extension mechanisms and coded character sets. Conformance requirements will be the subject of other CCITT Recommendations specific to particular telematic services.
+
+## 2 Graphic character sets
+
+### 2.1 *Primary set*
+
+2.1.1 The primary set of graphic characters specified in Figure 1/T.51 is identical with the set of graphic characters of the International Reference Version (IRV) of the 7-bit coded character set of Recommendation T.50.
+
+2.1.2 The primary set is designated as G0 by the sequence ESC 2/8 4/2. It can also be alternatively designated as G1, G2 or G3 by the sequences ESC 2/9 4/2, ESC 2/10 4/2 or ESC 2/11 4/2 respectively. See § 3 for details on code extension techniques.
+
+Terminals used for telematic services which make reference to the 1988 version of Recommendation T.51 use, for the designation of the primary set as G0, the sequence ESC 2/8 4/0 and alternatively as G1, G2 and G3, the sequences ESC 2/9 4/0, ESC 2/10 4/0, ESC 2/11 4/0.
+
+### 2.2 *Supplementary set*
+
+2.2.1 The supplementary set of graphic characters is specified in Figure 2/T.51.
+
+2.2.2 Unallocated code positions are subject to future standardization and will be allocated when a need for such is identified.
+
+2.2.3 The supplementary set is designated as G2 by the sequence ESC 2/14 5/2. It can be alternatively designated as G1 or G3 by the sequences ESC 2/13 5/2 or ESC 2/15 5/2 respectively.
+
+Terminals used for telematic services which make reference to the 1988 version of Recommendation T.51 use, for the designation of the supplementary set as G2, the sequence ESC 2/10 6/2 and alternatively as G0, G1 and G3, the sequences ESC 2/8 6/2, ESC 2/9 6/2, ESC 2/11 6/2.
+
+#### 2.2.4 *Notes on the primary and supplementary sets of graphic characters for Figures 1/T.51 and 2/T.51*
+
+In the figures the number of the note being referred to is encircled.
+
+*Note 1* – All the characters in column 4 of the supplementary set are non-spacing characters. They are all diacritical marks.
+
+*Note 2* – Cross-shaded code positions are reserved for future standardization by the CCITT.
+
+*Note 3* – Terminals used for current CCITT defined telematic services may send and receive the codes 2/6 and 2/4 of the supplementary set for the NUMBER SIGN and DOLLAR SIGN, respectively. When receiving codes 2/3 and 2/4 from the primary set of graphic characters, terminals may interpret them as # and ¢ respectively. Future applications in telematic services should code the NUMBER SIGN, CURRENCY SIGN and DOLLAR SIGN in accordance with Figures 1/T.51 and 2/T.51.
+
+*Note 4* – Terminals used for CCITT defined telematic services should send only the codes 4/1 of the supplementary set followed by SPACE for a stand-alone grave accent, 4/3 of the supplementary set followed by SPACE for a stand-alone circumflex accent, and 4/4 of the supplementary set followed by SPACE for a stand-alone tilde. Whenever a telematic terminal is capable of receiving and interpreting codes 6/0, 5/14 and 7/14 from the primary set of graphic characters, terminals shall interpret them as GRAVE, CIRCUMFLEX and TILDE respectively.
+
+*Note 5* – This code position is reserved and shall not be used.
+
+*Note 6* – Current telematic services may interpret this as the non-spacing underline. The non-spacing underline character is never used individually but always in combination with some other graphic character to represent the graphic rendition “underlined” for the associated character. The non-spacing underline character can be used in combination with any graphic character of the repertoire, including an accented letter or an umlaut, or space. It is recommended to implement the “underline” function by means of the control function SGR(4) instead of the “non-spacing underline” graphic character. However, both must be correctly interpreted when received.
+
+|                |                |                |                |    |                |   |   |                 |   |   |                |                |                |
+|----------------|----------------|----------------|----------------|----|----------------|---|---|-----------------|---|---|----------------|----------------|----------------|
+|                |                |                |                |    | b <sub>7</sub> | 0 | 0 | 0               | 0 | 1 | 1              | 1              | 1              |
+|                |                |                |                |    | b <sub>6</sub> | 0 | 0 | 1               | 1 | 0 | 0              | 1              | 1              |
+|                |                |                |                |    | b <sub>5</sub> | 0 | 1 | 0               | 1 | 0 | 1              | 0              | 1              |
+|                |                |                |                |    |                | 0 | 1 | 2               | 3 | 4 | 5              | 6              | 7              |
+| b <sub>4</sub> | b <sub>3</sub> | b <sub>2</sub> | b <sub>1</sub> |    |                |   |   |                 |   |   |                |                |                |
+| 0              | 0              | 0              | 0              | 0  |                |   |   |                 | 0 | @ | P              | ‘ <sup>④</sup> | p              |
+| 0              | 0              | 0              | 1              | 1  |                |   |   | !               | 1 | A | Q              | a              | q              |
+| 0              | 0              | 1              | 0              | 2  |                |   |   | "               | 2 | B | R              | b              | r              |
+| 0              | 0              | 1              | 1              | 3  |                |   |   | # <sup>③</sup>  | 3 | C | S              | c              | s              |
+| 0              | 1              | 0              | 0              | 4  |                |   |   | \$ <sup>③</sup> | 4 | D | T              | d              | t              |
+| 0              | 1              | 0              | 1              | 5  |                |   |   | %               | 5 | E | U              | e              | u              |
+| 0              | 1              | 1              | 0              | 6  |                |   |   | &               | 6 | F | V              | f              | v              |
+| 0              | 1              | 1              | 1              | 7  |                |   |   | '               | 7 | G | W              | g              | w              |
+| 1              | 0              | 0              | 0              | 8  |                |   |   | (               | 8 | H | X              | h              | x              |
+| 1              | 0              | 0              | 1              | 9  |                |   |   | )               | 9 | I | Y              | i              | y              |
+| 1              | 0              | 1              | 0              | 10 |                |   |   | *               | : | J | Z              | j              | z              |
+| 1              | 0              | 1              | 1              | 11 |                |   |   | +               | ; | K | [              | k              | {              |
+| 1              | 1              | 0              | 0              | 12 |                |   |   | ,               | < | L | \              | l              |                |
+| 1              | 1              | 0              | 1              | 13 |                |   |   | –               | = | M | ]              | m              | }              |
+| 1              | 1              | 1              | 0              | 14 |                |   |   | .               | > | N | ^ <sup>④</sup> | n              | ~ <sup>④</sup> |
+| 1              | 1              | 1              | 1              | 15 |                |   |   | /               | ? | O | _              | o              |                |
+
+T0811620-93
+
+*Note* – Notes to this figure are contained in § 2.2.4.
+
+FIGURE 1/T.51
+
+**The primary set of graphic characters for telematic services**  
+(coded representation when invoked in columns 2-7 of the code table)
+
+|                |                |                |                |    |                |   |   |      |   |   |   |    |     |
+|----------------|----------------|----------------|----------------|----|----------------|---|---|------|---|---|---|----|-----|
+|                |                |                |                |    | b <sub>7</sub> | 0 | 0 | 0    | 0 | 1 | 1 | 1  | 1   |
+|                |                |                |                |    | b <sub>6</sub> | 0 | 0 | 1    | 1 | 0 | 0 | 1  | 1   |
+|                |                |                |                |    | b <sub>5</sub> | 0 | 1 | 0    | 1 | 0 | 1 | 0  | 1   |
+|                |                |                |                |    |                | 0 | 1 | 2    | 3 | 4 | 5 | 6  | 7   |
+| b <sub>4</sub> | b <sub>3</sub> | b <sub>2</sub> | b <sub>1</sub> |    |                |   |   |      |   |   |   |    |     |
+| 0              | 0              | 0              | 0              | 0  |                |   |   | NBSP | ° | ⑤ | — | Ω  | K   |
+| 0              | 0              | 0              | 1              | 1  |                |   |   | I    | ± | ‘ | ¹ | Æ  | æ   |
+| 0              | 0              | 1              | 0              | 2  |                |   |   | ¢    | ² | ⁄ | ® | Ð  | ð   |
+| 0              | 0              | 1              | 1              | 3  |                |   |   | £    | ³ | ^ | © | à  | ä   |
+| 0              | 1              | 0              | 0              | 4  |                |   |   | ③    | x | ~ | ™ | Ĥ  | ĥ   |
+| 0              | 1              | 0              | 1              | 5  |                |   |   | ¥    | μ | — | ♪ | ②  | ı   |
+| 0              | 1              | 1              | 0              | 6  |                |   |   | ③    | ¶ | ˘ | ˘ | IJ | ij  |
+| 0              | 1              | 1              | 1              | 7  |                |   |   | §    | · | · | · | Ł  | ł   |
+| 1              | 0              | 0              | 0              | 8  |                |   |   | ¤    | ÷ | ¨ | ② | Ł  | ł   |
+| 1              | 0              | 0              | 1              | 9  |                |   |   | ‘    | ’ | ⑤ | ② | Ø  | ø   |
+| 1              | 0              | 1              | 0              | 10 |                |   |   | “    | ” | ° | ② | Œ  | œ   |
+| 1              | 0              | 1              | 1              | 11 |                |   |   | «    | » | ‚ | ② | Œ  | œ   |
+| 1              | 1              | 0              | 0              | 12 |                |   |   | ←    | ¼ | ⑥ | ⅛ | þ  | þ   |
+| 1              | 1              | 0              | 1              | 13 |                |   |   | ↑    | ½ | ″ | ⅜ | ƒ  | ƒ   |
+| 1              | 1              | 1              | 0              | 14 |                |   |   | →    | ¾ | ˘ | ⅝ | Ŋ  | ŋ   |
+| 1              | 1              | 1              | 1              | 15 |                |   |   | ↓    | ¿ | ˘ | ⅞ | ˘n | SHY |
+
+① | T0811630-93
+
+Note – Notes to this figure are contained in § 2.2.4.
+
+FIGURE 2/T.51  
+The supplementary set of graphic characters for telematic services  
+(coded representation when invoked in columns 2-7 of the code table)
+
+## **3 Code extension technique**
+
+### *3.1 General*
+
+3.1.1 Code extension techniques are required for the designation of various graphic or control character sets and their invocation in the 7-bit set or 8-bit set in use. Such techniques are derived from ISO Standard 2022.
+
+3.1.2 This Recommendation describes only those code extension techniques currently specified for existing telematic services. Additional techniques will be further incorporated as they are identified for use in one or more telematic services.
+
+### *3.2 Definitions*
+
+For the purpose of code extension techniques given in this Recommendation, the following definitions apply.
+
+#### **3.2.1 bit combination**
+
+An ordered set of bits used for the representation of characters.
+
+#### **3.2.2 byte**
+
+A bit string that is operated upon as a unit and the size of which is independent of redundancy or framing techniques.
+
+#### **3.2.3 character**
+
+A member of a set of elements used for the organization, control or representation of data.
+
+#### **3.2.4 coded character set; code**
+
+A set of unambiguous rules that establishes a character set and the one-to-one relationship between the characters of the set and their bit combinations.
+
+#### **3.2.5 code extension**
+
+The techniques for the encoding of characters that are not included in the character set of a given code.
+
+#### **3.2.6 code table**
+
+A table showing the character allocated to each bit combination in a code.
+
+#### **3.2.7 control character**
+
+A control function the coded representation of which consists of a single bit combination.
+
+#### **3.2.8 control function**
+
+An action that affects the recording, processing, transmission or interpretation of data and that has a coded representation consisting of one or more bit combinations.
+
+#### **3.2.9 to designate**
+
+To identify a set of characters that are to be represented, in some cases immediately and in others on the occurrence of a further control function, in a prescribed manner.
+
+#### **3.2.10 environment**
+
+The characteristic that identifies the number of bits used to represent a character in a data processing or data communication system or in part of such a system.
+
+#### 3.2.11 **escape sequence**
+
+A bit string that is used for control purposes in code extension procedures and that consists of two or more bit combinations. The first of these bit combinations represents the character ESCAPE (1/11).
+
+#### 3.2.12 **final character**
+
+The character the bit combination of which terminates an escape sequence.
+
+#### 3.2.13 **graphic character**
+
+A character, other than a control function, that has a visual representation normally handwritten, printed or displayed.
+
+#### 3.2.14 **intermediate character**
+
+A character the bit combination of which occurs between that of the ESCAPE character and that of the Final character in an escape sequence consisting of more than two bit combinations.
+
+#### 3.2.15 **to invoke**
+
+To cause a designated set of characters to be represented by the prescribed bit combinations whenever those bit combinations occur, until an appropriate code extension function occurs.
+
+#### 3.2.16 **position**
+
+That part of a code table identified by its column and row coordinates.
+
+#### 3.2.17 **to represent**
+
+- a) to use a prescribed bit combination with the meaning of a character in a set of characters that has been designated and invoked; or
+- b) to use an escape sequence with the meaning of an additional control function.
+
+### 3.3 *Code extension facilities*
+
+These are depicted in Figure 3/T.51 for the 7-bit environment and Figure 4/T.51 for the 8-bit environment. They include the following functions:
+
+- a) designation and invocation of control sets C0 and C1 by means of the relevant escape sequences given in § 3.4;
+- b) designation of a graphic character set G0 by means of the relevant escape sequence given in § 3.4;
+- c) designation of up to three additional G-sets called G1, G2 and G3 by means of the relevant escape sequences given in § 3.4;
+- d) invocation of the designated graphic sets, by means of locking and/or non-locking shift functions, given in § 3.5;
+- e) designation and invocation of a complete code by means of the relevant escape sequence given in § 3.4.
+
+### 3.4 *Types of character sets*
+
+There are a number of different types of control and graphic character sets that can be designated and invoked for use in the 7-bit or 8-bit environment. These are listed in Table 3/T.51 and defined below. A given control or graphic character set can be designated by an escape sequence terminated by a Final character F from bit combination 4/0 to 7/14, specific to the character set to be designated. Final characters are allocated by ISO and registered in the ISO “International register of coded character sets to be used with escape sequences”.
+
+![Diagram illustrating code extension in a 7-bit environment, showing the relationship between control function sets (C0, C1), graphic sets (G0-G3), and various ESC sequences.](ebff22fb5dd6f50a90e44dca0f82f285_img.jpg)
+
+The diagram illustrates the code extension in a 7-bit environment, showing the relationship between control function sets (C0, C1), graphic sets (G0-G3), and various ESC sequences.
+
+**Control Function Sets:**
+
+- Repertoire of control functions for C0 sets:** Represented by a stack of rectangles. An arrow labeled **ESC 2/1 F** points to the **C0** set.
+- Single additional control functions represented by ESC F<sub>s</sub> or ESC 2/3 F:** A box with an arrow pointing to the **C1** set.
+- Repertoire of control functions for C1 sets:** Represented by a stack of rectangles. An arrow labeled **ESC 2/2 F** points to the **C1** set.
+- Specific control functions within the currently designated C1 set are represented by ESC F<sub>e</sub> sequences:** A box explaining the representation of C1 functions.
+
+**Graphic Sets:**
+
+- Repertoire of multiple-byte graphic sets:** Represented by a stack of rectangles. Arrows labeled **ESC 2/4 2/8 F**, **ESC 2/4 2/9 F**, **ESC 2/4 2/10 F**, and **ESC 2/4 2/11 F** point to **G0**, **G1**, **G2**, and **G3** respectively.
+- Repertoire of graphic sets:** Represented by stacks of rectangles. Arrows labeled **ESC 2/8 F** through **ESC 2/15 F** point to **G0**, **G1**, **G2**, and **G3**.
+
+**7-bit code in use:** A dashed box containing **C0** and a placeholder for a graphic set. 
+
+- S1** and **S0** (Shift-In/Shift-Out) invoke **G1** and **G0** into the code table.
+- LS2** and **LS3** (Locking Shift) invoke **G2** and **G3**.
+- SS2** and **SS3** (Single Shift) invoke one character from **G2** or **G3**.
+
+**Legend (Right Side):**
+
+- Solid horizontal arrow: **Designation and invocation of control functions**
+- Dashed horizontal arrow: **Invocation of graphic sets**
+- Dotted horizontal arrow: **Invocation of one graphic character**
+- Solid vertical/diagonal arrow: **Designation of graphic sets**
+
+Diagram illustrating code extension in a 7-bit environment, showing the relationship between control function sets (C0, C1), graphic sets (G0-G3), and various ESC sequences.
+
+T0811640-93
+
+FIGURE 3/T.51  
+**Code extension in a 7-bit environment**  
+(showing all shift functions)
+
+3.4.1 C0 set of 32 control characters (bit combinations 0/0 to 1/15). A C0 set is designated and invoked by the sequence ESC 2/1 F, where F identifies a registered C0 set.
+
+![Diagram illustrating code extension in an 8-bit environment, showing the relationship between control function sets (C0, C1), graphic sets (G0, G1, G2, G3), and various shift facilities (LS, SS, ESC).](f4fdd410cdb84df81274da55721e56fb_img.jpg)
+
+The diagram illustrates the code extension in an 8-bit environment, showing the relationship between control function sets (C0, C1), graphic sets (G0, G1, G2, G3), and various shift facilities (LS, SS, ESC).
+
+**Control Function Sets:**
+
+- Repertoire of control functions for C0 sets:** Represented by a stack of rectangles.
+- Single additional control functions represented by ESC  $F_s$  or ESC 02/3 F:** A central box.
+- Repertoire of control functions for C1 sets:** Represented by a stack of rectangles.
+
+**Invocation and Designation:**
+
+- ESC 02/1 F:** Designates and invokes C0 sets.
+- ESC 02/2 F:** Designates and invokes C1 sets.
+
+**8-bit code in use:** A dashed box containing C0 and C1 sets.
+
+**Graphic Sets (G0, G1, G2, G3):**
+
+- LS0, LS1, LS2, LS3:** Left Shift facilities.
+- LS1R, LS2R, LS3R:** Right Shift facilities.
+
+**Invocation of one graphic character:** Indicated by arrows from LS facilities to graphic sets.
+
+**Invocation of graphic sets:** Indicated by arrows from SS facilities to graphic sets.
+
+**Designation of graphic sets:** Indicated by arrows from ESC facilities to graphic sets.
+
+**Graphic Set Repertoires:**
+
+- Repertoire of multiple-byte graphic sets:** Represented by a stack of rectangles.
+- Repertoire of graphic sets:** Represented by a stack of rectangles.
+
+**ESC Facilities:**
+
+- ESC 02/4 02/8 F, ESC 02/4 02/9 F, ESC 02/4 02/10 F, ESC 02/4 02/11 F:** Designate G0.
+- ESC 02/4 02/13 F, ESC 02/4 02/14 F, ESC 02/4 02/15 F:** Designate G1.
+- ESC 02/8 F, ESC 02/9 F, ESC 02/10 F, ESC 02/11 F:** Designate G2.
+- ESC 02/15 F, ESC 02/14 F, ESC 02/13 F:** Designate G3.
+
+T0811650-93
+
+Diagram illustrating code extension in an 8-bit environment, showing the relationship between control function sets (C0, C1), graphic sets (G0, G1, G2, G3), and various shift facilities (LS, SS, ESC).
+
+FIGURE 4/T.51  
+Code extension in an 8-bit environment  
+(showing all shift facilities)
+
+3.4.2 C1 set of 32 control characters (bit combinations 8/0 to 9/15 in an 8-bit environment, or ESC 4/0 to ESC 5/15 in a 7-bit environment). A C1 set is designated and invoked by the sequence ESC 2/2 F, where F identifies a registered C1 set.
+
+3.4.3 G0 set of 94 graphic characters (bit combinations 2/1 to 7/14).
+
+3.4.4 G1, G2 and G3 sets of 94 graphic characters (bit combinations 2/1 to 7/14 or 10/1 to 15/14). A registered set of 94 graphic characters can be designated by the escape sequence ESC 2/8 F, ESC 2/9 F, ESC 2/10 F or ESC 2/11 F in order to be used as a G0, G1, G2 or G3 set respectively, where F identifies the designated set.
+
+3.4.5 G1, G2 and G3 sets of 96 graphic characters (bit combinations 2/0 to 7/15 or 10/0 to 15/15). A registered set of 96 graphic characters can be designated by the escape sequence ESC 2/13 F, ESC 2/14 F or ESC 2/15 F in order to be used as a G1, G2 or G3 set respectively, where F identifies the designated set.
+
+3.4.6 Multiple-byte G0 set of more than 94 graphic characters each represented by more than one bit combinations from 2/1 to 7/14. The designation sequence is ESC 2/4 2/8 F.
+
+3.4.7 Multiple-byte G1, G2 and G3 sets of more than 94 graphic characters each represented by more than one bit combination from 2/1 to 7/14 or from 10/1 to 15/14. A registered multiple-byte set of more than 94 graphic characters can be designated by the escape sequence ESC 2/4 F, ESC 2/4 2/9 F, ESC 2/4 2/10 F or ESC 2/4 2/11 F in order to be used as a G0, G1, G2 or G3 set respectively, where F identifies the designated set.
+
+3.4.8 Multiple-byte G1, G2 and G3 sets of more than 96 graphic characters each represented by more than one bit combination from 2/0 to 7/15 or from 10/0 to 15/15. A registered multiple-byte set of this type identified by a Final character F can be designated by the escape sequence ESC 2/4 2/13 F, ESC 2/4 2/14 F or ESC 2/4 2/15 F in order to be used as G1, G2 or G3 set respectively.
+
+3.4.9 Complete code containing all bit combinations 0/0 to 7/15 in 7-bit environment, or 0/0 to 15/15 in 8-bit environment. A complete code identified by a Final character F, can be designated and invoked by the escape sequence ESC 2/5 F.
+
+*Note* – Complete code is now referred to in ISO 2022 as “Coding System different from that of ISO 2022”.
+
+### 3.5 *Invocation functions*
+
+Following the designation of a G0, G1, G2 or G3 set as specified in § 3.4, any one of these sets will require invocation into the 7-bit or 8-bit in-use code table. This is performed by the use of either locking-shift functions or non-locking shift functions listed in Table 4/T.51. Coding for these functions is given in Table 5/T.51.
+
+#### 3.5.1 *Use of locking-shift functions*
+
+There are seven locking-shift functions as given in Tables 4/T.51 and 5/T.51. A locking-shift function invokes the relevant G0, G1, G2 or G3 set into columns 2 to 7 or into columns 10 to 15 (8-bit code only) in order to replace the previously invoked G-set. The occurrence of a locking-shift function shall not affect those bit combinations that are included in any escape sequence or those that follow single-shift function SS2 or SS3. If a particular set has already been invoked, use of the corresponding locking-shift function has no effect.
+
+#### 3.5.2 *Use of single-shift functions*
+
+The single-shift function SS2 shall invoke one character from the last designated G2 set. Similarly SS3 shall invoke one character from the last designated G3 set. In the case of using single-byte graphic sets, these invocations alter the meaning of the immediately following bit combination only and ascribe to it the meaning of the corresponding bit combination of the G2 or G3 set. The bit combination permitted to follow SS2 or SS3 is limited to one from columns 2 to 7. If a single-shift function is used to invoke a character from a multiple-byte set, the shift function will affect two or more bit-combinations to represent that character. The use of a single-shift function does not affect the current shift status established by a locking-shift function.
+
+TABLE 3/T.51
+
+### **Types of character sets**
+
+| Description                                                                    | Character set  | Designation sequence                               | Bit combinations                      |                                        |
+|--------------------------------------------------------------------------------|----------------|----------------------------------------------------|---------------------------------------|----------------------------------------|
+|                                                                                |                |                                                    | 7-bit environment                     | 8-bit environment                      |
+| Sets of 32 control characters (Note 1)                                         | C0<br>C1       | ESC 2/1 F<br>ESC 2/2 F                             | 0/0 to 1/15<br>ESC 4/1 to<br>ESC 5/15 | 00/00 to 01/15<br>08/00 to 09/15       |
+| Sets of 94 graphic characters                                                  | G0             | ESC 2/8 F                                          | 2/1 to 7/14                           | 02/01 to 07/14                         |
+|                                                                                | G1<br>G2<br>G3 | ESC 2/9 F<br>ESC 2/10 F<br>ESC 2/11                | 2/1 to 7/14                           | 02/01 to 07/14<br>or<br>10/01 to 15/14 |
+|                                                                                |                |                                                    |                                       |                                        |
+| Sets of 96 graphic characters                                                  | G1<br>G2<br>G3 | ESC 2/13 F<br>ESC 2/14 F<br>ESC 2/15 F             | 2/0 to 7/15                           | 02/00 to 07/15<br>or<br>10/00 to 15/15 |
+| Sets of more than 94 graphic characters each represented by more than one byte | G0             | ESC 2/4 F (Note 2)<br>ESC 2/4 2/8 F                | 2/1 to 7/14                           | 02/01 to 07/14                         |
+|                                                                                | G1<br>G2<br>G3 | ESC 2/4 2/9 F<br>ESC 2/4 2/10 F<br>ESC 2/4 2/11 F  | 2/1 to 7/14                           | 02/01 to 07/14<br>or<br>10/01 to 15/14 |
+|                                                                                |                |                                                    |                                       |                                        |
+| Sets of more than 96 graphic characters each represented by more than one byte | G1<br>G2<br>G3 | ESC 2/4 2/13 F<br>ESC 2/4 2/14 F<br>ESC 2/4 2/15 F | 2/0 to 7/15                           | 02/00 to 07/15<br>or<br>10/00 to 15/15 |
+| Complete code                                                                  |                | ESC 2/5 F                                          | 0/0 to 7/15                           | 00/00 to 15/15                         |
+
+*Note 1* – Control sets C0 and C1, and complete codes are simultaneously designated and invoked by the relevant escape sequences indicated.
+
+*Note 2* – Multi-byte character sets are to be designated by four-character escape sequences. However, the following three-character escape sequences have in the past been registered and their use is valid for the registered multi-byte character sets:
+
+ESC 2/4 4/0;  
+ESC 2/4 4/1;  
+ESC 2/4 4/2.
+
+TABLE 4/T.51
+
+#### **Allocation of shift functions to the graphic character sets to be invoked**
+
+|       | Locking-shift functions                  |                                   | Non-locking shift functions             |
+|-------|------------------------------------------|-----------------------------------|-----------------------------------------|
+| A set | Columns 2 to 7<br>of 7-bit or 8-bit code | Columns 10 to 15<br>of 8-bit code | Columns 2 to 7<br>of 7-bit or 8bit code |
+| G0    | SI(7-bit), LS0(8-bit)                    | –                                 | –                                       |
+| G1    | SO(7-bit), LS1(8- bit)                   | LS1R                              | –                                       |
+| G2    | LS2                                      | LS2R                              | SS2                                     |
+| G3    | LS3                                      | LS3R                              | SS3                                     |
+
+TABLE 5/T.51
+
+#### **Coding for shift functions**
+
+| Shift functions                        | Coding             |
+|----------------------------------------|--------------------|
+| Single-shift two                       | SS2<br>1/9         |
+| Single-shift three                     | SS3<br>1/13        |
+| Shift in SI(7-bit), locking-shift zero | LS0(8-bit)<br>0/15 |
+| Shift out SO(7-bit), locking-shift one | LS1(8-bit)<br>0/14 |
+| Locking-shift one right                | LS1R<br>ESC 7/14   |
+| Locking-shift two                      | LS2<br>ESC 6/14    |
+| Locking-shift two right                | LS2R<br>ESC 7/13   |
+| Locking-shift three                    | LS3<br>ESC 6/15    |
+| Locking-shift three right              | LS3R<br>ESC 7/12   |
+
+# ANNEX A (to Recommendation T.51)
+
+## **Superset of the repertoire of the Latin based character set**
+
+A.1 This annex contains a unified superset of the repertoire of Latin based alphanumeric graphic characters.
+
+Each graphic character is identified by the identification system identical in that used in Recommendation T.61 (see § A.2).
+
+### A.2 *Identification system*
+
+A system was developed that allows for the identification and description of each graphic character or control function. The system is shown in Figure A-1/T.51.
+
+Each identifier consists of two letters and two digits.
+
+The first letter indicates the alphabet, the language, etc.
+
+The second letter indicates the letter of an alphabet or, in the case of a non-alphabetic graphic character or a control function, the group of characters or control functions.
+
+The first digit indicates whether the letter in the second position is an accented one, whether the diacritical mark is above or below the letter, etc. It has no special meaning in the case of the first letter being a C, N or S.
+
+The second digit indicates whether the letter is a capital or a small (even or odd). If the first letter is a C, N or S, this digit being even or odd has no significance.
+
+The numbering is used in a consistent manner so that each diacritical mark is always given the same number.
+
+The numbering principle is shown in Table A-1/T.51.
+
+TABLE A-1/T.51
+
+**Numbering principle for alphabetic characters**
+
+| Item                     | Small        | Capital      |
+|--------------------------|--------------|--------------|
+| No diacritical mark      | 01           | 02           |
+| Acuse accent             | 11           | 12           |
+| Grave accent             | 13           | 14           |
+| Circumflex accent        | 15           | 16           |
+| Diaeresis or umlaut mark | 17           | 18           |
+| Tilde                    | 19           | 20           |
+| Caron                    | 21           | 22           |
+| Breve                    | 23           | 24           |
+| Double acute accent      | 25           | 26           |
+| Ring                     | 27           | 28           |
+| Dot                      | 29           | 30           |
+| Macron                   | 31           | 32           |
+| Cedilla                  | 41           | 42           |
+| Ogonek                   | 43           | 44           |
+| Diphthong or ligature    | 51           | 52           |
+| Special form             | 61, 63, etc. | 62, 64, etc. |
+
+![A hierarchical tree diagram showing the identification system for alphanumeric characters. The root is 'L A 0 1'. It branches into 'L' (Latin alphabetic character), 'A' (control function), '0' (non-alphabetic graphic character), and '1' (special graphic character). Each branch has further sub-branches with specific rules and examples.](33ed1f9b27c7c21c797aa928b0f06851_img.jpg)
+
+**L**   **A**   **0**   **1**
+
+- L** = Latin alphabetic character;
+- A** = control function;
+- N** = non-alphabetic graphic character;
+- S** = special graphic character;
+- G** = Greek alphabetic character.
+
+**For alphabetic characters:**  
+ odd digit = small letter;  
+ even digit = capital letter.
+
+**If C, N or S in first position:**  
+ no special meaning.
+
+**For alphabetic characters:**  
+ zero = letter without diacritical mark;  
+ one, two or three = letter with diacritical mark above it;  
+ four = letter with diacritical mark below it;  
+ five = diphthong or ligature;  
+ six = special form.
+
+**If C, N or S in first position:**  
+ no special meaning.
+
+**For alphabetic characters:**  
+ A to Z = the respective letter of the Latin alphabet, or the Latin equivalent in the case of a non-Latin letter;
+
+**If C in first position:**  
+ E = code extension control function;  
+ F = format effector;  
+ P = presentation control function;  
+ M = other control function.
+
+**If N in first position:**  
+ D = decimal digit;  
+ F = fraction;  
+ S = subscript or superscript.
+
+**If S in first position:**  
+ A = arithmetic sign;  
+ C = currency sign;  
+ D = diacritical mark;  
+ P = punctuation mark;  
+ M = other symbol.
+
+A hierarchical tree diagram showing the identification system for alphanumeric characters. The root is 'L A 0 1'. It branches into 'L' (Latin alphabetic character), 'A' (control function), '0' (non-alphabetic graphic character), and '1' (special graphic character). Each branch has further sub-branches with specific rules and examples.
+
+FIGURE A-1/T.51  
+**Identification system**
+
+### A.3 *Combination of diacritical marks and basic letters*
+
+Figure A-2/T.51 specifies the combinations of diacritical marks and basic letters that are defined in this annex. This figure also shows ligatures and other characters.
+
+| Basic letters | Acute accent | Grave Accent | Circumflex accent | Diaeresis or umlaut accent | Tilde | Caron or hacek | Breve | Double acute accent | Ring | Dot abover | Macron | Cedilla | Ogonek | Ligature | Others     |
+|---------------|--------------|--------------|-------------------|----------------------------|-------|----------------|-------|---------------------|------|------------|--------|---------|--------|----------|------------|
+| <b>a A</b>    | á Á          | à À          | â Â               | ä Ä                        | ã Ã   |                | ă Ă   |                     | å Å  |            | ā Ā    |         | ą Ą    | æ Æ      |            |
+| <b>b B</b>    |              |              |                   |                            |       |                |       |                     |      |            |        |         |        |          |            |
+| <b>c C</b>    | ć Ć          |              | ĉ Ĉ               |                            |       | č Č            |       |                     |      | ċ Ċ        |        | ç Ç     |        |          |            |
+| <b>d D</b>    |              |              |                   |                            |       | ď Ď            |       |                     |      |            |        |         |        |          | đ Ðđ       |
+| <b>e E</b>    | é É          | è È          | ê Ê               | ë Ě                        |       | ě Ě            |       |                     |      | é Ê        | ē Ē    |         | ę Ę    |          |            |
+| <b>f F</b>    |              |              |                   |                            |       |                |       |                     |      |            |        |         |        |          |            |
+| <b>g G</b>    | g            |              | ĝ Ĝ               |                            |       |                | ğ Ğ   |                     |      | g Ğ        |        | Ġ       |        |          |            |
+| <b>h H</b>    |              |              | ĥ Ĥ               |                            |       |                |       |                     |      |            |        |         |        |          | h H        |
+| <b>i I</b>    | í Í          | ì Ì          | î Î               | ï Ï                        | ĩ Ĭ   |                |       |                     |      | ı          | ī Ī    |         | ı IJ    | ij IJ     | ı          |
+| <b>j J</b>    |              |              | ĵ Ĵ               |                            |       |                |       |                     |      |            |        |         |        |          |            |
+| <b>k K</b>    |              |              |                   |                            |       |                |       |                     |      |            |        | ķ Ķ     |        |          | κ          |
+| <b>l L</b>    | ĺ Ĺ          |              |                   |                            |       | ļ Ļ            |       |                     |      |            |        | ł Ł     |        |          | ℓ ℓ<br>ℓ ℓ |
+| <b>m M</b>    |              |              |                   |                            |       |                |       |                     |      |            |        |         |        |          |            |
+| <b>n N</b>    | ñ Ñ          |              |                   |                            | ñ Ñ   | ň Ň            |       |                     |      |            |        | ŋ Ŋ     |        |          | ŋ Ŋ        |
+| <b>o O</b>    | ó Ó          | ò Ò          | ô Ô               | ö Ö                        | õ Ö   |                |       | ő Ő                 |      |            | ō Ō    |         |        | œ Œ      | ø Ø        |
+| <b>p P</b>    |              |              |                   |                            |       |                |       |                     |      |            |        |         |        |          |            |
+| <b>q Q</b>    |              |              |                   |                            |       |                |       |                     |      |            |        |         |        |          |            |
+| <b>r R</b>    | í Ř          |              |                   |                            |       | ř Ř            |       |                     |      |            |        | ŕ Ŗ     |        |          |            |
+| <b>s S</b>    | ś Ś          |              | ŝ Š               |                            |       | š Š            |       |                     |      |            |        | ſ Š     |        |          | ß          |
+| <b>t T</b>    |              |              |                   |                            |       | ť Ť            |       |                     |      |            |        | ţ Ţ     |        |          | ţ Ţþ Þ     |
+| <b>u U</b>    | ú Ú          | ù Ù          | û Û               | ü Ü                        | ũ Ũ   |                | ű Ű   | ű Ű                 | ű Ű  |            | ū Ū    |         | ų Ų    |          |            |
+| <b>v V</b>    |              |              |                   |                            |       |                |       |                     |      |            |        |         |        |          |            |
+| <b>w W</b>    |              |              | ŵ Ŵ               |                            |       |                |       |                     |      |            |        |         |        |          |            |
+| <b>x X</b>    |              |              |                   |                            |       |                |       |                     |      |            |        |         |        |          |            |
+| <b>y Y</b>    | ý Ý          |              | ÿ Ŷ               | ÿ Ŷ                        |       |                |       |                     |      |            |        |         |        |          |            |
+| <b>z Z</b>    | ź Ź          |              |                   |                            |       | ž Ž            |       |                     |      | ž Ž        |        |         |        |          |            |
+
+T0816900-94
+
+FIGURE A-2/T.51  
+Use of alphabetical characters with dialectical marks, ligatures or others
+
+### A.4 *Specification of superset of Latin based character repertoire*
+
+### *Explanations on coded representation*
+
+- P-prefix denotes Primary Code Table;
+- S-prefix denotes Supplementary Code Table;
+- Absence of prefix denotes T.50 Basic Code Table (For SPACE and DELETE characters).
+
+### *Notes on implementation of the repertoire in telematic services*
+
+- (1) Not used in current teletex service (Recommendation T.61);
+- (2) Not used in any current telematic services;
+- (3) Currently used in Recommendation T.101, Videotex Data Syntax III only.
+
+### *General remarks*
+
+- a) The Latin based repertoire of teletex (Recommendation T.61), is represented by this superset, with exclusions defined by Notes (1), (2) and (3) above.
+- b) The Latin based repertoire of Recommendation T.101, Videotex Data Syntax I, is represented by the characters of the Primary Set with the exception that the REVERSE SOLIDUS is replaced by the YEN SIGN.
+- c) The Latin based repertoire of Recommendation T.101, Videotex Data Syntax II, is represented by this superset with exclusions defined by Notes (2) and (3) above, plus a few characters not within the scope of coding defined by the Primary Set and the Supplementary Set of this Recommendation.
+- d) The Latin based repertoire of Recommendation T.101, Videotex, Data Syntax III, is represented entirely by this superset.
+
+#### A.4.1 *Latin alphabet characters*
+
+| Identifier | Name                                   | Coded representation |
+|------------|----------------------------------------|----------------------|
+| LA01       | Latin small letter a                   | P 6/1                |
+| LA02       | Latin capital letter A                 | P 4/1                |
+| LA11       | Latin small letter a with acute        | S 4/2 P 6/1          |
+| LA12       | Latin capital letter A with acute      | S 4/2 P 4/1          |
+| LA13       | Latin small letter a with grave        | S 4/1 P 6/1          |
+| LA14       | Latin capital letter A with grave      | S 4/1 P 4/1          |
+| LA15       | Latin small letter a with circumflex   | S 4/3 P 6/1          |
+| LA16       | Latin capital letter A with circumflex | S 4/3 P 4/1          |
+| LA17       | Latin small letter a with diaeresis    | S 4/8 P 6/1          |
+| LA18       | Latin capital letter A with diaeresis  | S 4/8 P 4/1          |
+| LA19       | Latin small letter a with tilde        | S 4/4 P 6/1          |
+| LA20       | Latin capital letter A with tilde      | S 4/4 P 4/1          |
+| LA23       | Latin small letter a with breve        | S 4/6 P 6/1          |
+| LA24       | Latin capital letter A with breve      | S 4/6 P 4/1          |
+| LA27       | Latin small letter a with ring above   | S 4/10 P 6/1         |
+| LA28       | Latin capital letter A with ring above | S 4/10 P 4/1         |
+| LA31       | Latin small letter a with macron       | S 4/5 P 6/1          |
+| LA32       | Latin capital letter A with macron     | S 4/5 P 4/1          |
+| LA43       | Latin small letter a with ogonek       | S 4/14 P 6/1         |
+| LA44       | Latin capital letter A with ogonek     | S 4/14 P 4/1         |
+| LA51       | Latin small ligature æ                 | S 7/1                |
+| LA52       | Latin capital ligature Æ               | S 6/1                |
+| LB01       | Latin small letter b                   | P 6/2                |
+| LB02       | Latin capital letter B                 | P 4/2                |
+| LC01       | Latin small letter c                   | P 6/3                |
+| LC02       | Latin capital letter C                 | P 4/3                |
+
+| Identifier | Name                                   | Coded representation |       |
+|------------|----------------------------------------|----------------------|-------|
+| LC11       | Latin small letter c with acute        | S 4/2                | P 6/3 |
+| LC12       | Latin capital letter C with acute      | S 4/2                | P 4/3 |
+| LC15       | Latin small letter c with circumflex   | S 4/3                | P 6/3 |
+| LC16       | Latin capital letter C with circumflex | S 4/3                | P 4/3 |
+| LC21       | Latin small letter c with caron        | S 4/15               | P 6/3 |
+| LC22       | Latin capital letter C with caron      | S 4/15               | P 4/3 |
+| LC29       | Latin small letter c with dot above    | S 4/7                | P 6/3 |
+| LC30       | Latin capital letter C with dot above  | S 4/7                | P 4/3 |
+| LC41       | Latin small letter c with cedilla      | S 4/11               | P 6/3 |
+| LC42       | Latin capital letter C with cedilla    | S 4/11               | P 4/3 |
+| LD01       | Latin small letter d                   |                      | P 6/4 |
+| LD02       | Latin capital letter D                 |                      | P 4/4 |
+| LD21       | Latin small letter d with caron        | S 4/15               | P 6/4 |
+| LD22       | Latin capital letter D with caron      | S 4/15               | P 4/4 |
+| LD61       | Latin small letter d with stroke       | S 7/2                |       |
+| LD62       | Latin capital letter D with stroke     | S 6/2                |       |
+| LD63       | Latin small letter eth (icelandic)     | S 7/3                |       |
+| LE01       | Latin small letter e                   |                      | P 6/5 |
+| LE02       | Latin capital letter E                 |                      | P 4/5 |
+| LE11       | Latin small letter e with acute        | S 4/2                | P 6/5 |
+| LE12       | Latin capital letter E with acute      | S 4/2                | P 4/5 |
+| LE13       | Latin small letter e with grave        | S 4/1                | P 6/5 |
+| LE14       | Latin capital letter E with grave      | S 4/1                | P 4/5 |
+| LE15       | Latin small letter e with circumflex   | S 4/3                | P 6/5 |
+| LE16       | Latin capital letter E with circumflex | S 4/3                | P 4/5 |
+| LE17       | Latin small letter e with diaeresis    | S 4/8                | P 6/5 |
+| LE18       | Latin capital letter E with diaeresis  | S 4/8                | P 4/5 |
+| LE21       | Latin small letter e with caron        | S 4/15               | P 6/5 |
+| LE22       | Latin capital letter E with caron      | S 4/15               | P 4/5 |
+| LE29       | Latin small letter e with dot above    | S 4/7                | P 6/5 |
+| LE30       | Latin capital letter E with dot above  | S 4/7                | P 4/5 |
+| LE31       | Latin small letter e with macron       | S 4/5                | P 6/5 |
+| LE32       | Latin capital letter E with macron     | S 4/5                | P 4/5 |
+| LE43       | Latin small letter e with ogonek       | S 4/14               | P 6/5 |
+| LE44       | Latin capital letter E with ogonek     | S 4/14               | P 4/5 |
+| LF01       | Latin small letter f                   |                      | P 6/6 |
+| LF02       | Latin capital letter F                 |                      | P 4/6 |
+| LG01       | Latin small letter g                   |                      | P 6/7 |
+| LG02       | Latin capital letter G                 |                      | P 4/7 |
+| LG11       | Latin small letter g with cedilla      | S 4/2                | P 6/7 |
+| LG15       | Latin small letter g with circumflex   | S 4/3                | P 6/7 |
+| LG16       | Latin capital letter G with circumflex | S 4/3                | P 4/7 |
+| LG23       | Latin small letter g with breve        | S 4/6                | P 6/7 |
+| LG24       | Latin capital letter G with breve      | S 4/6                | P 4/7 |
+| LG29       | Latin small letter g with dot above    | S 4/7                | P 6/7 |
+| LG30       | Latin capital letter G with dot above  | S 4/7                | P 4/7 |
+| LG42       | Latin capital letter G with cedilla    | S 4/11               | P 4/7 |
+| LH01       | Latin small letter h                   |                      | P 6/8 |
+| LH02       | Latin capital letter H                 |                      | P 4/8 |
+| LH15       | Latin small letter h with circumflex   | S 4/3                | P 6/8 |
+| LH16       | Latin capital letter H with circumflex | S 4/3                | P 4/8 |
+| LH61       | Latin small letter h with stroke       | S 7/4                |       |
+| LH62       | Latin capital letter H with stroke     | S 6/4                |       |
+| LI01       | Latin small letter i                   |                      | P 6/9 |
+| LI02       | Latin capital letter I                 |                      | P 4/9 |
+| LI11       | Latin small letter i with acute        | S 4/2                | P 6/9 |
+| LI12       | Latin capital letter I with acute      | S 4/2                | P 4/9 |
+| LI13       | Latin small letter i with grave        | S 4/1                | P 6/9 |
+| LI14       | Latin capital letter I with grave      | S 4/1                | P 4/9 |
+
+| Identifier | Name                                        | Coded representation |        |
+|------------|---------------------------------------------|----------------------|--------|
+| LI15       | Latin small letter i with circumflex        | S 4/3                | P 6/9  |
+| LI16       | Latin capital letter I with circumflex      | S 4/3                | P 4/9  |
+| LI17       | Latin small letter i with diaeresis         | S 4/8                | P 6/9  |
+| LI18       | Latin capital letter I with diaeresis       | S 4/8                | P 4/9  |
+| LI19       | Latin small letter i with tilde             | S 4/4                | P 6/9  |
+| LI20       | Latin capital letter I with tilde           | S 4/4                | P 4/9  |
+| LI30       | Latin capital letter I with dot above       | S 4/7                | P 4/9  |
+| LI31       | Latin small letter i with macron            | S 4/5                | P 6/9  |
+| LI32       | Latin capital letter I with macron          | S 4/5                | P 4/9  |
+| LI43       | Latin small letter i with ogonek            | S 4/14               | P 6/9  |
+| LI44       | Latin capital letter I with ogonek          | S 4/14               | P 4/9  |
+| LI51       | Latin small ligature ij                     | S 7/6                |        |
+| LI52       | Latin capital ligature IJ                   | S 6/6                |        |
+| LI61       | Latin small letter dotless i                | S 7/5                |        |
+| LJ01       | Latin small letter j                        |                      | P 6/10 |
+| LJ02       | Latin capital letter J                      |                      | P 4/10 |
+| LJ15       | Latin small letter j with circumflex        | S 4/3                | P 6/10 |
+| LJ16       | Latin capital letter J with circumflex      | S 4/3                | P 4/10 |
+| LK01       | Latin small letter k                        |                      | P 6/11 |
+| LK02       | Latin capital letter K                      |                      | P 4/11 |
+| LK41       | Latin small letter k with cedilla           | S 4/11               | P 6/11 |
+| LK42       | Latin capital letter K with cedilla         | S 4/11               | P 4/11 |
+| LK61       | Latin small letter kra (greenlandic)        | S 7/0                |        |
+| LL01       | Latin small letter l                        |                      | P 6/12 |
+| LL02       | Latin capital letter L                      |                      | P 4/12 |
+| LL11       | Latin small letter l with acute             | S 4/2                | P 6/12 |
+| LL12       | Latin capital letter L with acute           | S 4/2                | P 4/12 |
+| LL21       | Latin small letter l with caron             | S 4/15               | P 6/12 |
+| LL22       | Latin capital letter L with caron           | S 4/15               | P 4/12 |
+| LL41       | Latin small letter l with cedilla           | S 4/11               | P 6/12 |
+| LL42       | Latin capital letter L with cedilla         | S 4/11               | P 4/12 |
+| LL61       | Latin small letter l with stroke            | S 7/8                |        |
+| LL62       | Latin capital letter L with stroke          | S 6/8                |        |
+| LL63       | Latin small letter l with middle dot        | S 7/7                |        |
+| LL64       | Latin capital letter L with middle dot      | S 6/7                |        |
+| LM01       | Latin small letter m                        |                      | P 6/13 |
+| LM02       | Latin capital letter M                      |                      | P 4/13 |
+| LN01       | Latin small letter n                        |                      | P 6/14 |
+| LN02       | Latin capital letter N                      |                      | P 4/14 |
+| LN11       | Latin small letter n with acute             | S 4/2                | P 6/14 |
+| LN12       | Latin capital letter N with acute           | S 4/2                | P 4/14 |
+| LN19       | Latin small letter n with tilde             | S 4/4                | P 6/14 |
+| LN20       | Latin capital letter N with tilde           | S 4/4                | P 4/14 |
+| LN21       | Latin small letter n with caron             | S 4/15               | P 6/14 |
+| LN22       | Latin capital letter N with caron           | S 4/15               | P 4/14 |
+| LN41       | Latin small letter n with cedilla           | S 4/11               | P 6/14 |
+| LN42       | Latin capital letter N with cedilla         | S 4/11               | P 4/14 |
+| LN61       | Latin small letter eng (lappish)            | S 7/14               |        |
+| LN62       | Latin capital letter ENG (lappish)          | S 6/14               |        |
+| LN63       | Latin small letter n preceded by apostrophe | S 6/15               |        |
+| LO01       | Latin small letter o                        |                      | P 6/15 |
+| LO02       | Latin capital letter O                      |                      | P 4/15 |
+| LO11       | Latin small letter o with acute             | S 4/2                | P 6/15 |
+| LO12       | Latin capital letter O with acute           | S 4/2                | P 4/15 |
+| LO13       | Latin small letter o with grave             | S 4/1                | P 6/15 |
+| LO14       | Latin capital letter O with grave           | S 4/1                | P 4/15 |
+| LO15       | Latin small letter o with circumflex        | S 4/3                | P 6/15 |
+| LO16       | Latin capital letter O with circumflex      | S 4/3                | P 4/15 |
+
+| Identifier | Name                                     | Coded representation |        |
+|------------|------------------------------------------|----------------------|--------|
+| LO17       | Latin small letter o with diaeresis      | S 4/8                | P 6/15 |
+| LO18       | Latin capital letter O with diaeresis    | S 4/8                | P 4/15 |
+| LO19       | Latin small letter o with tilde          | S 4/4                | P 6/15 |
+| LO20       | Latin capital letter O with tilde        | S 4/4                | P 4/15 |
+| LO25       | Latin small letter o with double acute   | S 4/13               | P 6/15 |
+| LO26       | Latin capital letter O with double acute | S 4/13               | P 4/15 |
+| LO31       | Latin small letter o with macron         | S 4/5                | P 6/15 |
+| LO32       | Latin capital letter O with macron       | S 4/5                | P 4/15 |
+| LO51       | Latin small ligature œ                   | S 7/10               |        |
+| LO52       | Latin capital ligature Π                | S 6/10               |        |
+| LO61       | Latin small letter o with stroke         | S 7/9                |        |
+| LO62       | Latin capital letter O with stroke       | S 6/9                |        |
+| LP01       | Latin small letter p                     |                      | P 7/0  |
+| LP02       | Latin capital letter P                   |                      | P 5/0  |
+| LQ01       | Latin small letter q                     |                      | P 7/1  |
+| LQ02       | Latin capital letter Q                   |                      | P 5/1  |
+| LR01       | Latin small letter r                     |                      | P 7/2  |
+| LR02       | Latin capital letter R                   |                      | P 5/2  |
+| LR11       | Latin small letter r with acute          | S 4/2                | P 7/2  |
+| LR12       | Latin capital letter R with acute        | S 4/2                | P 5/2  |
+| LR21       | Latin small letter r with caron          | S 4/15               | P 7/2  |
+| LR22       | Latin capital letter R with caron        | S 4/15               | P 5/2  |
+| LR41       | Latin small letter r with cedilla        | S 4/11               | P 7/2  |
+| LR42       | Latin capital letter R with cedilla      | S 4/11               | P 5/2  |
+| LS01       | Latin small letter s                     |                      | P 7/3  |
+| LS02       | Latin capital letter S                   |                      | P 5/3  |
+| LS11       | Latin small letter s with acute          | S 4/2                | P 7/3  |
+| LS12       | Latin capital letter S with acute        | S 4/2                | P 5/3  |
+| LS15       | Latin small letter s with circumflex     | S 4/3                | P 7/3  |
+| LS16       | Latin capital letter S with circumflex   | S 4/3                | P 5/3  |
+| LS21       | Latin small letter s with caron          | S 4/15               | P 7/3  |
+| LS22       | Latin capital letter S with caron        | S 4/15               | P 5/3  |
+| LS41       | Latin small letter s with cedilla        | S 4/11               | P 7/3  |
+| LS42       | Latin capital letter S with cedilla      | S 4/11               | P 5/3  |
+| LS61       | Latin small letter sharp s (german)      | S 7/11               |        |
+| LT01       | Latin small letter t                     |                      | P 7/4  |
+| LT02       | Latin capital letter T                   |                      | P 5/4  |
+| LT21       | Latin small letter t with caron          | S 4/15               | P 7/4  |
+| LT22       | Latin capital letter T with caron        | S 4/15               | P 5/4  |
+| LT41       | Latin small letter t with cedilla        | S 4/11               | P 7/4  |
+| LT42       | Latin capital letter T with cedilla      | S 4/11               | P 5/4  |
+| LT61       | Latin small letter t with stroke         | S 7/13               |        |
+| LT62       | Latin capital letter T with stroke       | S 6/13               |        |
+| LT63       | Latin small letter thorn (icelandic)     | S 7/12               |        |
+| LT64       | Latin capital letter thorn (icelandic)   | S 6/12               |        |
+| LU01       | Latin small letter u                     |                      | P 7/5  |
+| LU02       | Latin capital letter U                   |                      | P 5/5  |
+| LU11       | Latin small letter u with acute          | S 4/2                | P 7/5  |
+| LU12       | Latin capital letter U with acute        | S 4/2                | P 5/5  |
+| LU13       | Latin small letter u with grave          | S 4/1                | P 7/5  |
+| LU14       | Latin capital letter U with grave        | S 4/1                | P 5/5  |
+| LU15       | Latin small letter u with circumflex     | S 4/3                | P 7/5  |
+| LU16       | Latin capital letter U with circumflex   | S 4/3                | P 5/5  |
+| LU17       | Latin small letter u with diaeresis      | S 4/8                | P 7/5  |
+| LU18       | Latin capital letter U with diaeresis    | S 4/8                | P 5/5  |
+| LU19       | Latin small letter u with tilde          | S 4/4                | P 7/5  |
+| LU20       | Latin capital letter U with tilde        | S 4/4                | P 5/5  |
+| LU23       | Latin small letter u with breve          | S 4/6                | P 7/5  |
+| LU24       | Latin capital letter U with breve        | S 4/6                | P 5/5  |
+
+| Identifier | Name                                     | Coded representation |        |
+|------------|------------------------------------------|----------------------|--------|
+| LU25       | Latin small letter u with double acute   | S 4/13               | P 7/5  |
+| LU26       | Latin capital letter U with double acute | S 4/13               | P 5/5  |
+| LU27       | Latin small letter u with ring above     | S 4/10               | P 7/5  |
+| LU28       | Latin capital letter U with ring above   | S 4/10               | P 5/5  |
+| LU31       | Latin small letter u with macron         | S 4/5                | P 7/5  |
+| LU32       | Latin capital letter U with macron       | S 4/5                | P 5/5  |
+| LU43       | Latin small letter u with ogonek         | S 4/14               | P 7/5  |
+| LU44       | Latin capital letter U with ogonek       | S 4/14               | P 5/5  |
+| LV01       | Latin small letter v                     |                      | P 7/6  |
+| LV02       | Latin capital letter V                   |                      | P 5/6  |
+| LW01       | Latin small letter w                     |                      | P 7/7  |
+| LW02       | Latin capital letter W                   |                      | P 5/7  |
+| LW15       | Latin small letter w with circumflex     | S 4/3                | P 7/7  |
+| LW16       | Latin capital letter W with circumflex   | S 4/3                | P 5/7  |
+| LX01       | Latin small letter x                     |                      | P 7/8  |
+| LX02       | Latin capital letter X                   |                      | P 5/8  |
+| LY01       | Latin small letter y                     |                      | P 7/9  |
+| LY02       | Latin capital letter Y                   |                      | P 5/9  |
+| LY11       | Latin small letter y with acute          | S 4/2                | P 7/9  |
+| LY12       | Latin capital letter Y with acute        | S 4/2                | P 5/9  |
+| LY15       | Latin small letter y with circumflex     | S 4/3                | P 7/9  |
+| LY16       | Latin capital letter Y with circumflex   | S 4/3                | P 5/9  |
+| LY17       | Latin small letter y with diaeresis      | S 4/8                | P 7/9  |
+| LY18       | Latin capital letter Y with diaeresis    | S 4/8                | P 5/9  |
+| LZ01       | Latin small letter z                     |                      | P 7/10 |
+| LZ02       | Latin capital letter Z                   |                      | P 5/10 |
+| LZ11       | Latin small letter z with acute          | S 4/2                | P 7/10 |
+| LZ12       | Latin capital letter Z with acute        | S 4/2                | P 5/10 |
+| LZ21       | Latin small letter z with caron          | S 4/15               | P 7/10 |
+| LZ22       | Latin capital letter Z with caron        | S 4/15               | P 5/10 |
+| LZ29       | Latin small letter z with dot above      | S 4/7                | P 7/10 |
+| LZ30       | Latin capital letter Z with dot above    | S 4/7                | P 5/10 |
+
+#### A.4.2 Non-alphabetic characters
+
+##### A.4.2.1 Decimal digits
+
+| Identifier | Name        | Coded representation |
+|------------|-------------|----------------------|
+| ND01       | Digit one   | P 3/1                |
+| ND02       | Digit two   | P 3/2                |
+| ND03       | Digit three | P 3/3                |
+| ND04       | Digit four  | P 3/4                |
+| ND05       | Digit five  | P 3/5                |
+| ND06       | Digit six   | P 3/6                |
+| ND07       | Digit seven | P 3/7                |
+| ND08       | Digit eight | P 3/8                |
+| ND09       | Digit nine  | P 3/9                |
+| ND10       | Digit zero  | P 3/0                |
+
+##### A.4.2.2 *Currency signs*
+
+| Identifier | Name          | Coded representation |
+|------------|---------------|----------------------|
+| NC01       | Currency sign | S 2/8                |
+| NC02       | Pound sign    | S 2/3                |
+| NC03       | Dollar sign   | P 2/4                |
+| NC04       | Cent sign     | S 2/2                |
+| NC05       | Yen sing      | S 2/5                |
+
+##### A.4.2.3 *Punctuation marks*
+
+| Identifier | Name                                       | Coded representation | Notes |
+|------------|--------------------------------------------|----------------------|-------|
+| SP01       | Espace                                     | 2/0                  |       |
+| SP02       | Exclamation mark                           | P 2/1                |       |
+| SP03       | Inverted exclamation mark                  | P 2/1                |       |
+| SP04       | Quotation mark                             | P 2/2                |       |
+| SP05       | Apostrophe                                 | P 2/7                |       |
+| SP06       | Left parenthesis                           | P 2/8                |       |
+| SP07       | Right parenthesis                          | P 2/9                |       |
+| SP08       | Comma                                      | P 2/12               |       |
+| SP09       | Low line                                   | P 5/13               |       |
+| SP10       | Hyphen-minus                               | P 2/13               |       |
+| SP11       | Full stop                                  | P 2/14               |       |
+| SP12       | Solidus                                    | P 2/15               |       |
+| SP13       | Colon                                      | P 3/10               |       |
+| SP14       | Semicolon                                  | P 3/11               |       |
+| SP15       | Question mark                              | P 3/15               |       |
+| SP16       | Inverted question mark                     | S 3/15               |       |
+| SP17       | Left-pointing double angle quotation mark  | S 2/11               |       |
+| SP18       | Right-pointing double angle quotation mark | S 3/11               |       |
+| SP19       | Left single quotation mark                 | S 2/9                | (1)   |
+| SP20       | Right single quotation mark                | S 3/9                | (1)   |
+| SP21       | Left double quotation mark                 | S 2/10               | (1)   |
+| SP22       | Right double quotation mark                | S 3/10               | (1)   |
+| SP31       | No-break space                             | S 2/0                | (2)   |
+| SP32       | Soft hyphen                                | S 7/15               | (2)   |
+
+*Note* – In teletex and videotex, quotation mark, apostrophe and comma are independent characters that cannot have the meaning of diacritical marks.
+
+##### A.4.2.4 *Arithmetic signs*
+
+| Identifier | Name                | Coded representation |
+|------------|---------------------|----------------------|
+| SA01       | Plus sign           | P 2/11               |
+| SA02       | Plus-minus sign     | S 3/1                |
+| SA03       | Less-than sign      | P 3/12               |
+| SA04       | Equals sign         | P 3/13               |
+| SA05       | Greater-than sign   | P 3/14               |
+| SA06       | Division sign       | S 3/8                |
+| SA07       | Multiplication sign | S 3/4                |
+
+##### A.4.2.5 *Subscripts and superscripts*
+
+| Identifier | Name              | Coded representation |
+|------------|-------------------|----------------------|
+| NS01       | Superscript one   | S 5/1                |
+| NS02       | Superscript two   | S 3/2                |
+| NS03       | Superscript three | S 3/3                |
+
+##### A.4.2.6 *Fractions*
+
+| Identifier | Name                           | Coded representation | Notes |
+|------------|--------------------------------|----------------------|-------|
+| NF01       | Vulgar fraction one half       | S 3/13               |       |
+| NF04       | Vulgar fraction one quarter    | S 3/12               |       |
+| NF05       | Vulgar fraction three quarters | S 3/14               |       |
+| NF18       | Vulgar fraction one eighth     | S 5/12               | (1)   |
+| NF19       | Vulgar fraction three eighths  | S 5/13               | (1)   |
+| NF20       | Vulgar fraction five eighths   | S 5/14               | (1)   |
+| NF21       | Vulgar fraction seven eighths  | S 5/15               | (1)   |
+
+#### A.4.3 *Miscellaneous symbols*
+
+| Identifier | Name                        | Coded representation | Notes |
+|------------|-----------------------------|----------------------|-------|
+| SM01       | Number sign                 | P 2/3                |       |
+| SM02       | Percent sign                | P 2/5                |       |
+| SM03       | Ampersand                   | P 2/6                |       |
+| SM04       | Asterisk                    | P 2/10               |       |
+| SM05       | Commercial AT               | P 4/0                |       |
+| SM06       | Left square bracket         | P 5/11               |       |
+| SM07       | Reverse solidus             | P 5/12               | (1)   |
+| SM08       | Right square bracket        | P 5/13               |       |
+| SM11       | Left curly bracket          | P 7/11               | (1)   |
+| SM12       | Horizontal bar              | S 5/0                | (3)   |
+| SM13       | Verticle line               | P 7/12               |       |
+| SM14       | Right curly bracket         | P 7/13               | (1)   |
+| SM17       | Micro sign                  | S 3/5                |       |
+| SM18       | Ohm sign                    | S 6/0                |       |
+| SM19       | Degree sign                 | S 3/0                |       |
+| SM20       | Masculine ordinal indicator | S 6/11               |       |
+| SM21       | Femenine ordinal indicator  | S 6/3                |       |
+| SM24       | Section sign                | S 2/7                |       |
+| SM25       | Pilcrow sign                | S 3/6                |       |
+| SM26       | Middle dot                  | S 3/7                |       |
+| SM30       | Leftwards arrow             | S 2/12               | (1)   |
+| SM31       | Rightwards arrow            | S 2/14               | (1)   |
+| SM32       | Upwards arrow               | S 2/13               | (1)   |
+| SM33       | Downwards arrow             | S 2/15               | (1)   |
+| SM52       | Copyright sign              | S 5/3                | (1)   |
+| SM53       | Registered sign             | S 5/2                | (1)   |
+| SM54       | Trade mark sign             | S 5/4                | (1)   |
+| SM93       | Music note                  | S 5/5                | (1)   |
+| SM95       | Broken bar                  | S 5/7                | (2)   |
+| SM96       | Not sign                    | S 5/6                | (2)   |
+
+#### A.4.4 *Diacritical marks as separate graphic characters*
+
+| Identifier | Name                | Coded representation |     |
+|------------|---------------------|----------------------|-----|
+| SD11       | Acute accent        | S 4/2                | 2/0 |
+| SD13       | Grave accent        | S 4/1                | 2/0 |
+| SD15       | Circumflex accent   | S 4/3                | 2/0 |
+| SD17       | Diaeresis           | S 4/8                | 2/0 |
+| SD19       | Tilde               | S 4/4                | 2/0 |
+| SD21       | Caron               | S 4/15               | 2/0 |
+| SD23       | Breve               | S 4/6                | 2/0 |
+| SD25       | Double acute accent | S 4/13               | 2/0 |
+| SD27       | Ring above          | S 4/10               | 2/0 |
+| SD29       | Dot above           | S 4/7                | 2/0 |
+| SD31       | Macron              | S 4/5                | 2/0 |
+| SD41       | Cedilla             | S 4/11               | 2/0 |
+| SD43       | Ogonek              | S 4/14               | 2/0 |
+
+*Note* – The grave accent, circumflex accent and tilde are also coded as P 6/0, P 5/14 and P 7/14 respectively.
+
+#### A.4.5 *Special character*
+
+| Identifier | Name   | Coded representation |
+|------------|--------|----------------------|
+| SM34       | Delete | 7/15                 |
+
+# ANNEX B (to Recommendation T.51)
+
+**Table of character and control sets**
+
+| Register No. | Name of registered set                                                                     | (Note 1) | Final character | C0 | C1 | G0 | G1 | G2 | G3 |
+|--------------|--------------------------------------------------------------------------------------------|----------|-----------------|----|----|----|----|----|----|
+| 1            | Primary control set of IRV                                                                 |          | 4/0             | x  |    |    |    |    |    |
+| 6            | Rec. T.50 International reference version (IRV). This is also the primary set of Rec. T.51 | 94       | 4/2             |    |    | x  | x  | x  | x  |
+| 132          | Rec. T.101 Data syntax I Primary control set                                               | C0       | 4/9             | x  |    |    |    |    |    |
+| 125          | Rec. T.101 Data Syntax I Supplementary control set                                         | C1       | 4/4             |    | x  |    |    |    |    |
+| 42           | Rec. T.101 Data Syntax I Kanji set (2 byte set) JISC 6226 (1978)                           | 94 × 94  | 4/0             |    |    | x  | x  | x  | x  |
+| 137          | Rec. T.101 Data Syntax I Mosaic 1 set                                                      | 94       | 7/9             |    |    | x  | x  | x  | x  |
+| 14           | Rec. T.101 Data Syntax I Primary character set JISC 6220 (1969)                            | 94       | 4/10            |    |    | x  | x  | x  | x  |
+| 131          | Rec. T.101 Data Syntax I Complete code                                                     | –        | 4/3             |    |    |    |    |    |    |
+| 134          | Rec. T.101 Data Syntax II Primary control set                                              | C0       | 4/10            | x  |    |    |    |    |    |
+| 56           | Rec. T.101 Data Syntax II Serial supplementary control set                                 | C1       | 4/0             |    | x  |    |    |    |    |
+| 73           | Rec. T.101 Data Syntax II Parallel supplementary control set                               | C1       | 4/1             |    | x  |    |    |    |    |
+| 70           | Rec. T.101 Data Syntax II Supplementary character set                                      | 94       | 6/2             |    |    | x  | x  | x  | x  |
+
+| Register No.         | Name of registered set                                                | (Note 1) | Final character                   | C0 | C1 | G0 | G1 | G2 | G3 |
+|----------------------|-----------------------------------------------------------------------|----------|-----------------------------------|----|----|----|----|----|----|
+| 71                   | Rec. T.101 Data Syntax II<br>2nd supplementary mosaic set             | 94       | 6/3                               |    |    | x  | x  | x  | x  |
+| 72                   | Rec. T.101 Data Syntax II<br>3rd supplementary mosaic set             | 94       | 6/4                               |    |    | x  | x  | x  | x  |
+| 145                  | Rec. T.101 Data Syntax II<br>Complete code                            | –        | 4/4                               |    |    |    |    |    |    |
+| 150                  | Rec. T.52 Greek primary set                                           | 94       | 2/1 4/0                           |    |    | x  | x  | x  | x  |
+| 108                  | Rec. T.101 Data Syntax III<br>Complete code                           | –        | 4/1                               |    |    |    |    |    |    |
+| 135                  | Rec. T.101 Data Syntax III<br>Primary control set                     | C0       | 4/11                              | x  |    |    |    |    |    |
+| 136                  | Rec. T.101 Data Syntax III<br>Supplementary control set               | C1       | 4/6                               |    | x  |    |    |    |    |
+| 6                    | Rec. T.101 Data Syntax III<br>Primary character set                   | 94       | 4/2                               |    |    | x  | x  | x  | x  |
+| 128                  | Rec. T.101 Data Syntax III<br>Supplementary character set             | 94       | 7/12                              |    |    | x  | x  | x  | x  |
+| Cannot be registered | Rec. T.101 Data Syntax III<br>PDI set                                 | 96       | (5/7) never to be assigned by ISO |    |    |    | x  | x  | x  |
+| 129                  | Rec. T.101 Data Syntax III<br>Mosaic set                              | 96       | 7/13                              |    |    | x  | x  | x  | x  |
+| 102                  | Rec. T.61 Primary graphic character set<br>(left half of Fig. 2/T.61) | 94       | 7/5                               |    |    | x  | x  | x  | x  |
+| 103                  | Rec. T.61 Supplementary character set<br>(right half of Fig. 2/T.61)  | 94       | 7/6                               |    |    | x  | x  | x  | x  |
+| 106                  | Rec. T.61 Primary control set                                         | C0       | 4/5                               | x  |    |    |    |    |    |
+| 107                  | Rec. T.61 Supplementary control set                                   | C1       | 4/8                               |    | x  |    |    |    |    |
+
+| Register No. | Name of registered set                              | (Note 1)      | Final character | C0 | C1 | G0 | G1 | G2 | G3 |
+|--------------|-----------------------------------------------------|---------------|-----------------|----|----|----|----|----|----|
+| 156          | Rec. T.51 Supplementary graphic set                 | 96            | 5/2             |    |    |    | x  | x  | x  |
+| Up-dated 87  | Rec. T.52 Kanji set (2 byte set)<br>JIS × 0208-1990 | 94 × 94       | 4/2<br>(Note 2) |    |    | x  | x  | x  | x  |
+| 164          | Rec. T.52 Hebrew supplementary set                  | 96            | 5/3             |    |    |    | x  | x  | x  |
+| 144          | Rec. T.52 Cyrillic supplementary set                | 96            | 4/12            |    |    |    | x  | x  | x  |
+| 13           | Rec. T.52 Katakana set                              | 96            | 4/9             |    |    |    | x  | x  | x  |
+| 89           | Rec. T.52 Arabic set                                | 94            | 6/11            |    |    | x  | x  | x  | x  |
+| 165          | Rec. T.52 Chinese set                               | 94 × 94       | 4/5             |    |    | x  | x  | x  | x  |
+| 161          | Rec. T.101 Audio Data Syntax                        | Complete code | 4/5             |    |    |    |    |    |    |
+| 162          | Rec. T.101 Photo-Videotex Data Syntax               | Complete Code | 4/5             |    |    |    |    |    |    |
+
+*Note 1* – The 94 or 96 character set applies only to single byte graphic character sets. The 94 × 94 set applies to two byte graphic character sets. Primary control sets are C0. Supplementary control sets are C1. Complete code is also referred to as “Coding System different from that of ISO 2022”.
+
+*Note 2* – The designation sequences are:
+
+ESC 02/06 04/00 ESC 02/04 04/02 for G0  
+ESC 02/06 04/00 ESC 02/04 02/09 04/02 for G1  
+ESC 02/06 04/00 ESC 02/04 02/10 04/02 for G2  
+ESC 02/06 04/00 ESC 02/04 02/11 04/02 for G3
+
+# ANNEX C
+
+(to Recommendation T.51)
+
+## Alphabetical list of abbreviations used in this Recommendation
+
+ESC ESCAPE
+
+IRV International reference version
\ No newline at end of file
diff --git a/marked/T/T-REC-T.52-199303-I_PDF-E/011a9e8fc583e8d7229fb8d6af496f10_img.jpg b/marked/T/T-REC-T.52-199303-I_PDF-E/011a9e8fc583e8d7229fb8d6af496f10_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..19912d49fc27079bf9d8f54553e723e325b67240
--- /dev/null
+++ b/marked/T/T-REC-T.52-199303-I_PDF-E/011a9e8fc583e8d7229fb8d6af496f10_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:72c8308101e17239223e454454ec95753867217b57dbbb8a311b64d98bdd7fe1
+size 653
diff --git a/marked/T/T-REC-T.52-199303-I_PDF-E/084f910f81ff123bb184312cc8512e1b_img.jpg b/marked/T/T-REC-T.52-199303-I_PDF-E/084f910f81ff123bb184312cc8512e1b_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..7099719e4d77a0069db2459c44a0953118726567
--- /dev/null
+++ b/marked/T/T-REC-T.52-199303-I_PDF-E/084f910f81ff123bb184312cc8512e1b_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:be59c47ca08faa5e4af4d0a46a70edc8751314e1b7996593d766bb0b6f859eb5
+size 771
diff --git a/marked/T/T-REC-T.52-199303-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/T/T-REC-T.52-199303-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..f35d00715ba84b30b94063f27ceee725831746a1
--- /dev/null
+++ b/marked/T/T-REC-T.52-199303-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:67a6508db41cb178b2ba17013d422b2bd950779a872fd2246a059568f0e51bf6
+size 8373
diff --git a/marked/T/T-REC-T.52-199303-I_PDF-E/378ff90e3f79a29b79c94a7ef01676f9_img.jpg b/marked/T/T-REC-T.52-199303-I_PDF-E/378ff90e3f79a29b79c94a7ef01676f9_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..679ee17b60151f3766d3bc3caf3f616ef9f264bb
--- /dev/null
+++ b/marked/T/T-REC-T.52-199303-I_PDF-E/378ff90e3f79a29b79c94a7ef01676f9_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:e28008c1be807b5b29e57d68068fe0e3a5c31776d8d7e3fa4f9a8535ec43cb33
+size 709
diff --git a/marked/T/T-REC-T.52-199303-I_PDF-E/37d5041d044f6dc9d8d9026f4a4753c9_img.jpg b/marked/T/T-REC-T.52-199303-I_PDF-E/37d5041d044f6dc9d8d9026f4a4753c9_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..b0732daa55c95a62bba398b5201d4f65e020d931
--- /dev/null
+++ b/marked/T/T-REC-T.52-199303-I_PDF-E/37d5041d044f6dc9d8d9026f4a4753c9_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:14d5f46d73a4b790193923a53ead7cf0e1af2d95287d9831560c70d99cc63c48
+size 721
diff --git a/marked/T/T-REC-T.52-199303-I_PDF-E/3bf1696c3034743b5ab07a0b5e398347_img.jpg b/marked/T/T-REC-T.52-199303-I_PDF-E/3bf1696c3034743b5ab07a0b5e398347_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..b63c767ed1db6fd9060de628d2f93f71693f7de1
--- /dev/null
+++ b/marked/T/T-REC-T.52-199303-I_PDF-E/3bf1696c3034743b5ab07a0b5e398347_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:8a9d57c35820cda2293594fa7fc252e531dfcf61c7bf76e2bb6b6dd335f96cef
+size 3537
diff --git a/marked/T/T-REC-T.52-199303-I_PDF-E/4307b4d58b44c82325c2f42798a1f18e_img.jpg b/marked/T/T-REC-T.52-199303-I_PDF-E/4307b4d58b44c82325c2f42798a1f18e_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..b3a94bebdb97846f139ff4c74f15c70b694b617f
--- /dev/null
+++ b/marked/T/T-REC-T.52-199303-I_PDF-E/4307b4d58b44c82325c2f42798a1f18e_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:2a4232409560d4bf841d949abdedff1c84b62f043d1b85685f84ad2bc7a3d106
+size 829
diff --git a/marked/T/T-REC-T.52-199303-I_PDF-E/4385c1e975681bcd050ccaac8d47355a_img.jpg b/marked/T/T-REC-T.52-199303-I_PDF-E/4385c1e975681bcd050ccaac8d47355a_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..24d35ac22154607ed978cea4f356f6836fd76791
--- /dev/null
+++ b/marked/T/T-REC-T.52-199303-I_PDF-E/4385c1e975681bcd050ccaac8d47355a_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:4defd5d28ff7d567ba1a1628429087f2ec979a69f1d674931909b3d801022b90
+size 688
diff --git a/marked/T/T-REC-T.52-199303-I_PDF-E/4c0a305d338b75154734ab0effea91dd_img.jpg b/marked/T/T-REC-T.52-199303-I_PDF-E/4c0a305d338b75154734ab0effea91dd_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..dcf515360a68fe239fc9fc22b5afd98be7c69089
--- /dev/null
+++ b/marked/T/T-REC-T.52-199303-I_PDF-E/4c0a305d338b75154734ab0effea91dd_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:0e08702020afc75b3bbafb6c10a52d45b94a04bc56405bdffa2b35952972a342
+size 685
diff --git a/marked/T/T-REC-T.52-199303-I_PDF-E/4ea1428ee2e77dcdcd58b64c64c0ac99_img.jpg b/marked/T/T-REC-T.52-199303-I_PDF-E/4ea1428ee2e77dcdcd58b64c64c0ac99_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..734734839d3b17d50a635f198bcfb656ae6b76e0
--- /dev/null
+++ b/marked/T/T-REC-T.52-199303-I_PDF-E/4ea1428ee2e77dcdcd58b64c64c0ac99_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:912bfd6a30cc139af304cd905f595aabd742e4ab79d84ea71d8dc3a739b09e3f
+size 774
diff --git a/marked/T/T-REC-T.52-199303-I_PDF-E/50736af0a8362ac699778e85144ab0b9_img.jpg b/marked/T/T-REC-T.52-199303-I_PDF-E/50736af0a8362ac699778e85144ab0b9_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..e664ef4d5702e88aad0fa915ea08e3dbed38825b
--- /dev/null
+++ b/marked/T/T-REC-T.52-199303-I_PDF-E/50736af0a8362ac699778e85144ab0b9_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:5c3cd590f247ca416e07160e5e4196dd27d762e14aa8fd4ce1959b9cfe0a9767
+size 778
diff --git a/marked/T/T-REC-T.52-199303-I_PDF-E/555ff0b8e74a72222f323033fed090f9_img.jpg b/marked/T/T-REC-T.52-199303-I_PDF-E/555ff0b8e74a72222f323033fed090f9_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..facc3189431292497663e66c89451c99bf79d164
--- /dev/null
+++ b/marked/T/T-REC-T.52-199303-I_PDF-E/555ff0b8e74a72222f323033fed090f9_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:61266b67230f3225cf49f516f1dae317f87ef61a4ce0c7c63eaa41b302edbc6c
+size 705
diff --git a/marked/T/T-REC-T.52-199303-I_PDF-E/600e1fd3021b2599b53036f090addc87_img.jpg b/marked/T/T-REC-T.52-199303-I_PDF-E/600e1fd3021b2599b53036f090addc87_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..34a352ca2860c7c6fdcee56c89b9267661411060
--- /dev/null
+++ b/marked/T/T-REC-T.52-199303-I_PDF-E/600e1fd3021b2599b53036f090addc87_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:f30eb8dc46571024ee5fc913988ec178186b9dd166d9b7c4a48e826b881de975
+size 643
diff --git a/marked/T/T-REC-T.52-199303-I_PDF-E/778eada01e468fa925a5d65c31bc66d4_img.jpg b/marked/T/T-REC-T.52-199303-I_PDF-E/778eada01e468fa925a5d65c31bc66d4_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..95015fc69f5a63fd334af9837c31f8321c9f6063
--- /dev/null
+++ b/marked/T/T-REC-T.52-199303-I_PDF-E/778eada01e468fa925a5d65c31bc66d4_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:2464ed15e3ef202b22b368c9f86c35dfce5f13006b70ccaacb582cf6c1df7000
+size 1295
diff --git a/marked/T/T-REC-T.52-199303-I_PDF-E/86ef7cb744b859b239c1172800d1f65b_img.jpg b/marked/T/T-REC-T.52-199303-I_PDF-E/86ef7cb744b859b239c1172800d1f65b_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..f7feed26a84cd3ef5ff38799129fb3db74dfed54
--- /dev/null
+++ b/marked/T/T-REC-T.52-199303-I_PDF-E/86ef7cb744b859b239c1172800d1f65b_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:5c02f9ef120a1a6a2ce80967f46af4b736c8585f1292e0b163e76d5185bfad56
+size 1356
diff --git a/marked/T/T-REC-T.52-199303-I_PDF-E/883711b52496b36c72249e6e0be28a23_img.jpg b/marked/T/T-REC-T.52-199303-I_PDF-E/883711b52496b36c72249e6e0be28a23_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..268f238133d15cb32d4a03a7c0d3401335f44698
--- /dev/null
+++ b/marked/T/T-REC-T.52-199303-I_PDF-E/883711b52496b36c72249e6e0be28a23_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:85707da93d5c77616cfa2faf48be50667239ff17a2f9073227eb8ac5561051e4
+size 1055
diff --git a/marked/T/T-REC-T.52-199303-I_PDF-E/9a36fc7502b7faa1d98340d00826113e_img.jpg b/marked/T/T-REC-T.52-199303-I_PDF-E/9a36fc7502b7faa1d98340d00826113e_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..c15762c70e3f008f4f86ae48a96811620b41af99
--- /dev/null
+++ b/marked/T/T-REC-T.52-199303-I_PDF-E/9a36fc7502b7faa1d98340d00826113e_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:9f9a84fc3747ccb8dbd1a9c3c1905ae2f2d236fa6501d18b55e5fe81d3752cb7
+size 710
diff --git a/marked/T/T-REC-T.52-199303-I_PDF-E/9c32109813e9e5064569854d4f7302b9_img.jpg b/marked/T/T-REC-T.52-199303-I_PDF-E/9c32109813e9e5064569854d4f7302b9_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..23106053fdf6f181107fb997646978ba1cdfa0e0
--- /dev/null
+++ b/marked/T/T-REC-T.52-199303-I_PDF-E/9c32109813e9e5064569854d4f7302b9_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:419a59dce99d2dec59b16664d2c2f5ef243421ed8084c7faebbc8fa1bffc1df5
+size 807
diff --git a/marked/T/T-REC-T.52-199303-I_PDF-E/a1650823ee590dbc2474361bf5277e2b_img.jpg b/marked/T/T-REC-T.52-199303-I_PDF-E/a1650823ee590dbc2474361bf5277e2b_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..4ab93424b32e3660238c859a031b607f0a82a37f
--- /dev/null
+++ b/marked/T/T-REC-T.52-199303-I_PDF-E/a1650823ee590dbc2474361bf5277e2b_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:9b9d843d7c6742b9e7266a2710468dea49289980260432857fdb6e55078c3c5c
+size 880
diff --git a/marked/T/T-REC-T.52-199303-I_PDF-E/c6212a3b14736d6a8c81ace75ae94ccf_img.jpg b/marked/T/T-REC-T.52-199303-I_PDF-E/c6212a3b14736d6a8c81ace75ae94ccf_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..6abafef7dc53b54e88853ea3cde6eab32bc417b2
--- /dev/null
+++ b/marked/T/T-REC-T.52-199303-I_PDF-E/c6212a3b14736d6a8c81ace75ae94ccf_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:e6ddc26d577fd16eb4d672a33e88af6200246dd89c0e9a976e48d6553ddef362
+size 7900
diff --git a/marked/T/T-REC-T.52-199303-I_PDF-E/c6cfc0bead2b50b16514c759f6ebd99f_img.jpg b/marked/T/T-REC-T.52-199303-I_PDF-E/c6cfc0bead2b50b16514c759f6ebd99f_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..8db5ea320b25703af659136af5970c34d8314ee8
--- /dev/null
+++ b/marked/T/T-REC-T.52-199303-I_PDF-E/c6cfc0bead2b50b16514c759f6ebd99f_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:0938399477e3418971e7d1bdb6c47c8ce9edceb215512062918ba0e7b577016f
+size 714
diff --git a/marked/T/T-REC-T.52-199303-I_PDF-E/c7872781f87a3b2f71d8d9b349ac8cc1_img.jpg b/marked/T/T-REC-T.52-199303-I_PDF-E/c7872781f87a3b2f71d8d9b349ac8cc1_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..6068e2be34e3093bad338f6cc17b97331970102d
--- /dev/null
+++ b/marked/T/T-REC-T.52-199303-I_PDF-E/c7872781f87a3b2f71d8d9b349ac8cc1_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:f03a2821b47bc22764bc45b9cf8078554fe700e8d31ece80a83b73b78b25eb96
+size 758
diff --git a/marked/T/T-REC-T.52-199303-I_PDF-E/dd778f2bfad8a85166f04081e11fa595_img.jpg b/marked/T/T-REC-T.52-199303-I_PDF-E/dd778f2bfad8a85166f04081e11fa595_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..a4ea436692b05217b1370cbd8899b26a049d85ef
--- /dev/null
+++ b/marked/T/T-REC-T.52-199303-I_PDF-E/dd778f2bfad8a85166f04081e11fa595_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:711b156373b00f7b7486e7ccf946c9158502b83d6620c065de98bf50df2e6625
+size 1184
diff --git a/marked/T/T-REC-T.52-199303-I_PDF-E/e15938b37dea787f9282cb04f0a65eff_img.jpg b/marked/T/T-REC-T.52-199303-I_PDF-E/e15938b37dea787f9282cb04f0a65eff_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..0de0c24fee5112dd6067eefdffe35aa47602b1d4
--- /dev/null
+++ b/marked/T/T-REC-T.52-199303-I_PDF-E/e15938b37dea787f9282cb04f0a65eff_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:d76e871a18353133a4b0bd0f9c7419778ef1a80d284a22edeaf1519eb8042673
+size 764
diff --git a/marked/T/T-REC-T.52-199303-I_PDF-E/e52d9828bcef00a44441034fb77202c3_img.jpg b/marked/T/T-REC-T.52-199303-I_PDF-E/e52d9828bcef00a44441034fb77202c3_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..f6607a9960634c8a0e92bb0a46e50aba40725090
--- /dev/null
+++ b/marked/T/T-REC-T.52-199303-I_PDF-E/e52d9828bcef00a44441034fb77202c3_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:469bc154c4ab2c3cabeb8bd2147ca10a4bee8ef3d90c400c7baa772438b33341
+size 708
diff --git a/marked/T/T-REC-T.52-199303-I_PDF-E/e66cbb523c0ae780023c1a99869e5226_img.jpg b/marked/T/T-REC-T.52-199303-I_PDF-E/e66cbb523c0ae780023c1a99869e5226_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..7bff1a7488fd9a2b209b3c8b1e3fb875240ca137
--- /dev/null
+++ b/marked/T/T-REC-T.52-199303-I_PDF-E/e66cbb523c0ae780023c1a99869e5226_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:7e90f907baffda9a767762c6d71e073a7d94612237b63df4bf720444c030da5c
+size 757
diff --git a/marked/T/T-REC-T.52-199303-I_PDF-E/e776395ba1d4a6d568f08b406d784abd_img.jpg b/marked/T/T-REC-T.52-199303-I_PDF-E/e776395ba1d4a6d568f08b406d784abd_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..1f570f87b3e63e9286b3c07ee84f04b18f64d58f
--- /dev/null
+++ b/marked/T/T-REC-T.52-199303-I_PDF-E/e776395ba1d4a6d568f08b406d784abd_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:8ad9231c50591380456c88c0424ec7b3341cffca5cc3d91a175af11a870beff3
+size 4471
diff --git a/marked/T/T-REC-T.52-199303-I_PDF-E/e9d9b953cc095b6082bccfda070001e6_img.jpg b/marked/T/T-REC-T.52-199303-I_PDF-E/e9d9b953cc095b6082bccfda070001e6_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..95e50ad28e60b721b158023cc022c0878660dd7f
--- /dev/null
+++ b/marked/T/T-REC-T.52-199303-I_PDF-E/e9d9b953cc095b6082bccfda070001e6_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:b6eeec4996672d136cc1b32e5dfd5795a721eee1197132f5cf01214f642d8e0f
+size 1281
diff --git a/marked/T/T-REC-T.521-199411-I_PDF-E/0f985b39edc1d52ba3600c438bc8f0a5_img.jpg b/marked/T/T-REC-T.521-199411-I_PDF-E/0f985b39edc1d52ba3600c438bc8f0a5_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..bdb2be944411ddb7e79f00d1a4e00ab269956bce
--- /dev/null
+++ b/marked/T/T-REC-T.521-199411-I_PDF-E/0f985b39edc1d52ba3600c438bc8f0a5_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:6af726c0f34ae2e3648caa68945181bc3bd14bd696bb2d464ef251488f546d78
+size 38648
diff --git a/marked/T/T-REC-T.521-199411-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/T/T-REC-T.521-199411-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..9233d58fdc9878d91b10dd2119072b5ca1fe4b02
--- /dev/null
+++ b/marked/T/T-REC-T.521-199411-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:13a8d2e59e2cda6349fe2f2cae04594fc661bf709ef3f671c0afffdc6b340f80
+size 8337
diff --git a/marked/T/T-REC-T.521-199411-I_PDF-E/33ed1f9b27c7c21c797aa928b0f06851_img.jpg b/marked/T/T-REC-T.521-199411-I_PDF-E/33ed1f9b27c7c21c797aa928b0f06851_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..1b69358572902753be2d5d23d7d595fbb28f2a87
--- /dev/null
+++ b/marked/T/T-REC-T.521-199411-I_PDF-E/33ed1f9b27c7c21c797aa928b0f06851_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:fa25d832161a271e5b4a6f897d7415d3ffd3f78312e4ad077e6f91300f1c780e
+size 42369
diff --git a/marked/T/T-REC-T.521-199411-I_PDF-E/4801720824e4b5e2361a5564f91cfb70_img.jpg b/marked/T/T-REC-T.521-199411-I_PDF-E/4801720824e4b5e2361a5564f91cfb70_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..8e187f42eacf423dea9ca248d52e7cce0f492468
--- /dev/null
+++ b/marked/T/T-REC-T.521-199411-I_PDF-E/4801720824e4b5e2361a5564f91cfb70_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:38d29d933e82c85c52bf4566d8a688d71d03aa889119b830a581a62832ccf810
+size 148823
diff --git a/marked/T/T-REC-T.521-199411-I_PDF-E/5cab96b2d23174c25919840ecd50aa48_img.jpg b/marked/T/T-REC-T.521-199411-I_PDF-E/5cab96b2d23174c25919840ecd50aa48_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..bbfbec856bd5da28cfd0d5f469b3aecd82e33583
--- /dev/null
+++ b/marked/T/T-REC-T.521-199411-I_PDF-E/5cab96b2d23174c25919840ecd50aa48_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:705372bac1c31560c352cb584d402b3010e7020dcda0d4c68a383fb8906351ab
+size 44460
diff --git a/marked/T/T-REC-T.521-199411-I_PDF-E/7efae06af3af43ffe5d4b956a679cf54_img.jpg b/marked/T/T-REC-T.521-199411-I_PDF-E/7efae06af3af43ffe5d4b956a679cf54_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..109eff1ee92184d598f0fc85b6726039c6ad7042
--- /dev/null
+++ b/marked/T/T-REC-T.521-199411-I_PDF-E/7efae06af3af43ffe5d4b956a679cf54_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:40bb0bc1f1a038bb22ac291195dd51963771145b064466ceaeced95a15b0fca9
+size 54228
diff --git a/marked/T/T-REC-T.521-199411-I_PDF-E/90ee16ccc0ad16aeca48087797d7b07f_img.jpg b/marked/T/T-REC-T.521-199411-I_PDF-E/90ee16ccc0ad16aeca48087797d7b07f_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..d137914c77203f840f78c10c35c3f5093679af81
--- /dev/null
+++ b/marked/T/T-REC-T.521-199411-I_PDF-E/90ee16ccc0ad16aeca48087797d7b07f_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:ca1cbda8bbff8ecb45a15e4dd2c3554a623d2f3cc1e503bce7cec56d51960c64
+size 23092
diff --git a/marked/T/T-REC-T.521-199411-I_PDF-E/9cd90f495b95ad2116ff780248c26d95_img.jpg b/marked/T/T-REC-T.521-199411-I_PDF-E/9cd90f495b95ad2116ff780248c26d95_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..625295122afc5077f2ec0560c4d84546ba957e2f
--- /dev/null
+++ b/marked/T/T-REC-T.521-199411-I_PDF-E/9cd90f495b95ad2116ff780248c26d95_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:19d958fca0d02367f655220ef9c4e865636e23ba7e823fed1ff53392b7ac00d4
+size 33830
diff --git a/marked/T/T-REC-T.521-199411-I_PDF-E/acfc53eca625d62b38aa2563efa95c3e_img.jpg b/marked/T/T-REC-T.521-199411-I_PDF-E/acfc53eca625d62b38aa2563efa95c3e_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..2154db046f085648b8d8a5ed7086f9e6b66bf243
--- /dev/null
+++ b/marked/T/T-REC-T.521-199411-I_PDF-E/acfc53eca625d62b38aa2563efa95c3e_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:fabc73ce40da3f4277309eade8ac77628a55ca57530b99b5b680866654408e36
+size 68360
diff --git a/marked/T/T-REC-T.521-199411-I_PDF-E/dc23d430e878eb71b8cd589984113940_img.jpg b/marked/T/T-REC-T.521-199411-I_PDF-E/dc23d430e878eb71b8cd589984113940_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..c5eff2ef14ded320edf49b063f9b9427e7ba6dc4
--- /dev/null
+++ b/marked/T/T-REC-T.521-199411-I_PDF-E/dc23d430e878eb71b8cd589984113940_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:eb81c3ccfeff7dcd1253e5e44e65dfd953a55eef1bc38a89ec232f594a38b817
+size 35063
diff --git a/marked/T/T-REC-T.521-199411-I_PDF-E/fa859e4e468bfb2710a94527f2c504af_img.jpg b/marked/T/T-REC-T.521-199411-I_PDF-E/fa859e4e468bfb2710a94527f2c504af_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..2abce30c254302efb5e46a942835e8af4cfcac7a
--- /dev/null
+++ b/marked/T/T-REC-T.521-199411-I_PDF-E/fa859e4e468bfb2710a94527f2c504af_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:153467bbe772d9888dd1eb662facf2adf319739df5d4bc58cbd96897c9731c9f
+size 45572
diff --git a/marked/T/T-REC-T.521-199411-I_PDF-E/raw.md b/marked/T/T-REC-T.521-199411-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..80ca3f23a6cee4c37fb0eb6f2dbd64dd0cd9f371
--- /dev/null
+++ b/marked/T/T-REC-T.521-199411-I_PDF-E/raw.md
@@ -0,0 +1,775 @@
+
+
+![ITU logo: a globe with the letters ITU and a lightning bolt symbol.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg)
+
+ITU logo: a globe with the letters ITU and a lightning bolt symbol.
+
+INTERNATIONAL TELECOMMUNICATION UNION
+
+# ITU-T
+
+TELECOMMUNICATION  
+STANDARDIZATION SECTOR  
+OF ITU
+
+## T.521
+
+(11/94)
+
+### TERMINALS FOR TELEMATIC SERVICES
+
+---
+
+**COMMUNICATION APPLICATION  
+PROFILE BT0 FOR DOCUMENT  
+BULK TRANSFER BASED ON  
+THE SESSION SERVICE**
+
+**ITU-T Recommendation T.521**
+
+(Previously "CCITT Recommendation")
+
+---
+
+# FOREWORD
+
+The ITU-T (Telecommunication Standardization Sector) is a permanent organ of the International Telecommunication Union (ITU). The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis.
+
+The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics.
+
+The approval of Recommendations by the Members of the ITU-T is covered by the procedure laid down in WTSC Resolution No. 1 (Helsinki, March 1-12, 1993).
+
+ITU-T Recommendation T.521 was revised by ITU-T Study Group 8 (1993-1996) and was approved under the WTSC Resolution No. 1 procedure on the 11th of November 1994.
+
+# --- NOTE
+
+this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+© ITU 1995
+
+All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU.
+
+# CONTENTS
+
+|                                                                                 | <i>Page</i> |
+|---------------------------------------------------------------------------------|-------------|
+| 1 Scope and field of application .....                                          | 1           |
+| 2 References .....                                                              | 1           |
+| 3 Definitions .....                                                             | 1           |
+| 4 Abbreviations and conventions .....                                           | 1           |
+| 5 Definition of communication application profile BT0 .....                     | 1           |
+| 5.1 Overview of BT0 .....                                                       | 1           |
+| 5.2 DTAM functional units .....                                                 | 2           |
+| 5.3 DTAM service primitives and lower layer mapping .....                       | 2           |
+| 6 Document interchange data structures .....                                    | 9           |
+| 7 Document transfer .....                                                       | 9           |
+| 7.1 Synchronization .....                                                       | 9           |
+| 7.2 Document recovery .....                                                     | 9           |
+| Appendix I – Overall Protocol Sequence .....                                    | 9           |
+| Appendix II – Guidance for mapping of DTAM to Recommendation T.62 .....         | 13          |
+| Introduction .....                                                              | 13          |
+| II.1 Items to be considered when using DTAM on top of Recommendation T.62 ..... | 13          |
+
+# **SUMMARY**
+
+Recommendation this defines communication application profile for G4 facsimile apparatus. The definition of «additional document characteristics» in «application capabilities» for colour and other extension is added as an option in this revision.
+
+# COMMUNICATION APPLICATION PROFILE BT0 FOR DOCUMENT BULK TRANSFER BASED ON THE SESSION SERVICE
+
+(Geneva, 1992; revised in Geneva 1994)
+
+# 1 Scope and field of application
+
+This Recommendation defines the communication application profile for the document bulk transfer using the session service defined in Recommendation T.62 *bis* in terms of:
+
+- a) DTAM functional units used;
+- b) DTAM service primitives and parameters used;
+- c) lower layer X.215 session service mapping according to the rules of Recommendation T.62 *bis*.
+
+# 2 References
+
+The following references are required in order to implement the communication profile defined in this Recommendation.
+
+- CCITT Recommendation T.431 (1992), *Document Transfer and Manipulation (DTAM) – Services and Protocol – Introduction and General Principles*.
+- CCITT Recommendation T.432 (1992), *Document Transfer and Manipulation (DTAM) – Services and Protocols – Service Definition*.
+- CCITT Recommendation T.433 (1992), *Document Transfer and Manipulation (DTAM) – Services and Protocols – Protocol Specification*.
+- Recommendation T.62 (1993), *Control procedures for teletex and group 4 facsimile services*.
+- Recommendation T.62 *bis* (1993), *Control procedures for teletex and G4 facsimile services based on Recommendations X.215 and X.225*.
+- Recommendation X.215 (1994), *Information technology – Open Systems Interconnection – Session service definition*.
+
+# 3 Definitions
+
+The definitions in the T.400-Series Recommendations and Recommendation T.62 *bis* also apply to this Recommendation.
+
+# 4 Abbreviations and conventions
+
+The abbreviations and conventions defined in the T.400-Series Recommendations and Recommendation T.62 *bis* also apply to this Recommendation.
+
+# 5 Definition of communication application profile BT0
+
+## 5.1 Overview of BT0
+
+This Recommendation defines functional units and communication support functions in accordance with Recommendation T.431. BT0 uses the document bulk transfer in transparent mode (mapping to session service as defined in the T.430-Series Recommendations).
+
+## 5.2 DTAM functional units
+
+The following functional units defined in Recommendation T.432 are used for BT0:
+
+- association use control (Kernel);
+- capability;
+- document bulk transfer;
+- token control.
+
+NOTE – The capability functional unit must be supported in this profile, but it is not required to use this service prior to every document transfer (D-TRANSFER).
+
+## 5.3 DTAM service primitives and lower layer mapping
+
+### 5.3.1 DTAM service primitives and parameters
+
+The general DTAM service definition and parameters are defined in Recommendation T.432. This subclause specifies the parameters of the DTAM service for BT0.
+
+#### 5.3.1.1 D-INITIATE service parameters
+
+The following parameters of this service are used as follows:
+
+- transparent mode;
+- telematic requirements;
+- application capabilities;
+- result.
+
+Table 1-A lists the D-INITIATE service parameters.
+
+##### 1) *Transparent mode*
+
+This parameter shall be present in the D-INITIATE request service primitive.
+
+##### 2) *Telematic requirements*
+
+The following functional units defined in Recommendation T.432 are used for BT0 as mandatory functional units:
+
+- association use control (Kernel);
+- capability;
+- document bulk transfer;
+- token control.
+
+##### 3) *Application capabilities*
+
+This “Application capabilities” parameter is defined in Recommendation T.432 and the following sub-parameter is used:
+
+ODA Application capabilities:
+
+###### a) Document application profile
+
+The value of this parameter indicates the document application profile being used. Its value is specified in Recommendations that define terminal characteristics for particular Telematic services.
+
+###### b) Document architecture class
+
+The value of this parameter indicates the document architecture class used in the entire association. The use of this parameter and its possible value is specified in the Recommendations that define terminal characteristics for particular Telematic services.
+
+##### 4) *Result*
+
+This result field can take the values defined in Recommendation T.432.
+
+TABLE 1-A/T.521
+
+#### **D-INITIATE service parameters**
+
+|                                                                                                                            | D-INITIATE<br>request | D-INITIATE<br>indication | D-INITIATE<br>response | D-INITIATE<br>confirm |
+|----------------------------------------------------------------------------------------------------------------------------|-----------------------|--------------------------|------------------------|-----------------------|
+| Transparent mode                                                                                                           | M                     |                          |                        |                       |
+| Telematic requirements                                                                                                     | M                     | M(=)                     | C <sup>a)</sup>        | C(=)                  |
+| ODA Application capabilities                                                                                               | M                     | M(=)                     | C <sup>a)</sup>        | C(=)                  |
+| Document application profile                                                                                               | M                     | M(=)                     | C <sup>a)</sup>        | C(=)                  |
+| Document architecture class                                                                                                | M                     | M(=)                     | C <sup>a)</sup>        | C(=)                  |
+| Result                                                                                                                     |                       |                          | M                      | M(=)                  |
+| a) This parameter is mandatory in case the responder returns the “accepted” result parameter to the proposed requirements. |                       |                          |                        |                       |
+
+#### **5.3.1.2 D-TERMINATE service parameters**
+
+This service has no parameter for BT0. Only the initiator can issue D-TERMINATE service. In addition, the initiator can issue D-TERMINATE service only if he has the data token.
+
+#### **5.3.1.3 D-U-ABORT service parameters**
+
+This service has no parameter.
+
+#### **5.3.1.4 D-P-ABORT service parameter**
+
+This service has no parameter.
+
+#### **5.3.1.5 D-CAPABILITY service parameters**
+
+This service has the sub-parameter “ODA Application capabilities” which consists of the following parameters:
+
+- document application profile;
+- document architecture class;
+- non-basic document characteristics;
+- additional document characteristics.
+
+Table 1-B lists the D-CAPABILITY service parameters.
+
+##### 1) *Application capabilities*
+
+See 5.3.1.1.
+
+ODA Application capabilities:
+
+###### a) Document application profile
+
+See 5.3.1.1.
+
+- b) Document architecture class
+
+See 5.3.1.1.
+
+- c) Non-basic document characteristics
+
+This is the parameter “Non-basic document characteristics” defined in Recommendation T.432.
+
+- d) Additional document characteristics
+
+This is the parameter “Additional document characteristics” defined in Recommendation T414.
+
+TABLE 1-B/T.521
+
+##### **D-CAPABILITY service parameters**
+
+|                                     | D-CAPABILITY<br>request | D-CAPABILITY<br>indication | D-CAPABILITY<br>response | D-CAPABILITY<br>confirm |
+|-------------------------------------|-------------------------|----------------------------|--------------------------|-------------------------|
+| ODA Application capabilities        |                         |                            |                          |                         |
+| -----                               |                         |                            |                          |                         |
+| Document application profile        | M                       | M(=)                       | M                        | M(=)                    |
+| Document architecture class         | M                       | M(=)                       | M                        | M(=)                    |
+| Non-basic document characteristics  | U                       | C(=)                       | U                        | C(=)                    |
+| Additional document characteristics | U                       | C(=)                       | U                        | U                       |
+
+#### **5.3.1.6 D-TRANSFER service parameters**
+
+This service has the following parameters:
+
+- 1) *Document information*
+
+This parameter consists of the interchange data elements representing the document. The “Document characteristics” from the document profile are transferred using S-ACT-START service.
+
+All interchange data elements, except the document profile descriptor, are transferred using S-DATA services. The document profile is reconstructed by the received DTAM-PM, on the basis of the “Document characteristics” transferred in the S-ACT-START service.
+
+- 2) *Document information type*
+
+This parameter has the value “transfer of a document from its beginning” in the request primitive (see Recommendation T.432). For the indication and confirm primitive, the value is either “transfer completed” or “transfer not completed”.
+
+- 3) *Document reference information*
+
+The value of this parameter is to be provided by the DTAM user in accordance with the rules specified in Recommendation T.432.
+
+- 4) *Result*
+
+This parameter has one of the values “document information transferred” or “document information not completely transferred”, as defined in Recommendation T.432.
+
+NOTE – The parameter value “document-information-continuation not possible” is for further study.
+
+- 5) *Checkpoint value*
+
+This parameter is used as defined in Recommendation T.432. The number of IDE per segment is integer 2. However, the document profile and the document root are not counted (see Figure 1).
+
+![Diagram illustrating the application of the segmenting mechanism. It shows a sequence of document components: Document profile, Document root, Page, Content, Page, Content, ..., Page, content. These are grouped into Segment 1, Segment 2, and Segment n. Above the components are IDE labels with checkpoint values (1) and (2). A bracket indicates the first two IDEs are not counted. Below the segments are service primitives: S-ACT-START-req, S-MINOR-SYNC-req, S-ACT-END-req, S-DATA-req, and S-DATA connected by a hierarchy of lines.](acfc53eca625d62b38aa2563efa95c3e_img.jpg)
+
+Checkpoint value (subclause 5.3.1.5)
+
+These IDEs are not counted
+
+(1) (2) (1) (2) (1) (2) (1) (2)
+
+IDE IDE IDE IDE IDE IDE IDE IDE
+
+Document profile | Document root | Page | Content | Page | Content | ... | Page | content
+
+Segment 1 Segment 2 Segment n
+
+S-ACT-START-req
+
+S-MINOR-SYNC-req S-MINOR-SYNC-req
+
+S-ACT-END-req
+
+S-DATA-req S-DATA-req S-DATA-req S-DATA-req S-DATA-req S-DATA
+
+Diagram illustrating the application of the segmenting mechanism. It shows a sequence of document components: Document profile, Document root, Page, Content, Page, Content, ..., Page, content. These are grouped into Segment 1, Segment 2, and Segment n. Above the components are IDE labels with checkpoint values (1) and (2). A bracket indicates the first two IDEs are not counted. Below the segments are service primitives: S-ACT-START-req, S-MINOR-SYNC-req, S-ACT-END-req, S-DATA-req, and S-DATA connected by a hierarchy of lines.
+
+T0807010-91/d01
+
+FIGURE 1/T.521  
+**Application of the segmenting mechanism as defined in Figure 2/T.433**
+
+The following restriction is applied to the transfer syntax coding rules defined in Recommendation X.209 for the interchange of the document application profile defined in Recommendation T.503:
+
+- Length fields longer than three octets shall not be used. A length field of three octets allows for the representation of a length of up to 65 535. A data element with a length exceeding 65 535 shall have a length field of the indefinite form.
+
+Table 1-C lists the D-TRANSFER service parameters.
+
+TABLE 1-C/T.521
+
+##### **D-TRANSFER service parameters**
+
+| Parameter                                                                         | D-TRANSFER request | D-TRANSFER indication | D-TRANSFER confirm |
+|-----------------------------------------------------------------------------------|--------------------|-----------------------|--------------------|
+| Document information                                                              | M                  | M(=)                  |                    |
+| Document information type                                                         | M                  | M                     | M                  |
+| Document reference information                                                    | M                  | M(=)                  | M(=)               |
+| Result                                                                            |                    |                       | M                  |
+| Checkpoint value                                                                  | M                  |                       |                    |
+| NOTE – The document information is transferred using the type of normal document. |                    |                       |                    |
+
+#### 5.3.1.7 D-CONTROL GIVE service parameters
+
+The D-CONTROL GIVE service surrenders all available tokens and has no parameter.
+
+#### 5.3.1.8 D-TOKEN PLEASE service parameters
+
+The D-TOKEN PLEASE service is used to request the data token and has no parameter.
+
+### 5.3.2 Use of session service and parameter mapping
+
+#### 5.3.2.1 DTAM protocol mapping to X.215 session service
+
+This mapping rule is defined in 7.3/T.433.
+
+NOTE – D-TRANSFER confirm is implicitly formed by receipt of S-ACT END confirm, S-ACT INT confirm and S-ACT DCAD confirm.
+
+#### 5.3.2.2 DTAM parameter mapping to session service parameters
+
+Table 2-A shows the mapping rule between DTAM service parameters and basic and additional session service parameters.
+
+The category of parameters is defined as follows:
+
+- 1 parameters are generated by DTAM user;
+- 2 parameters are generated by DTAM provider;
+- 3 parameters provided by other means than DTAM-user or DTAM-provider.
+
+Appendix I illustrates the example of protocol sequences for BT0.
+
+TABLE 2-A/T.521
+
+##### **D-INITIATE**
+
+| DTAM service parameters                                                                                              | Basic and additional session service parameters                                                       | Presence in session protocol  | Category |
+|----------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------|-------------------------------|----------|
+| Telematic requirements                                                                                               | Session requirements                                                                                  | m (defaultable)               | 1        |
+| ODA – Application capabilities<br>-----<br>  Document application profile<br> -----<br>  Document architecture class | Session user data                                                                                     | m                             | 1        |
+| None                                                                                                                 | Session reference<br>-----<br>Window size<br>-----<br>Service identifier<br>-----<br>Inactivity timer | m<br><br>m<br><br>m<br><br>nm | 2        |
+| None                                                                                                                 | Private use<br>-----<br>Non-standardized capabilities                                                 | nm<br><br>nm                  | 3        |
+| m    Mandatory<br>nm   No mandatory                                                                                  |                                                                                                       |                               |          |
+
+TABLE 2-B/T.521
+
+##### **D-TERMINATE**
+
+| DTAM service parameters | Basic and additional session service parameters | Presence in session protocol | Category |
+|-------------------------|-------------------------------------------------|------------------------------|----------|
+| None                    | Session termination parameter                   | nm                           | 3        |
+
+TABLE 2-C/T.521
+
+##### **D-U-ABORT**
+
+| DTAM service parameters | Basic and additional session service parameters         | Presence in session protocol | Category |
+|-------------------------|---------------------------------------------------------|------------------------------|----------|
+| None                    | Session termination parameter<br>(Transport disconnect) | m                            | 3        |
+
+TABLE 2-D/T.521
+
+##### **D-CAPABILITY**
+
+| DTAM service parameters                                                                                                                                                   | Basic and additional session service parameters              | Presence in session protocol                 | Category |
+|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------|----------------------------------------------|----------|
+| ODA Application capabilities<br>-----<br>  Document application profile<br> -----<br>  Document architecture class<br> -----<br>  Non-basic document characteristics<br>  | Session user data                                            | m<br>-----<br>m<br>-----<br>m<br>-----<br>nm | 1        |
+| None                                                                                                                                                                      | Inactivity timer<br>-----<br>Storage capacity                | nm<br>-----<br>nm                            | 2        |
+| None                                                                                                                                                                      | Private use (Note)<br>-----<br>Non-standardized capabilities | nm<br>-----<br>nm                            | 3        |
+| NOTE – In case of file transfer, this parameter is used in accordance with the rules defined in Recommendation T.571. The use for facsimile Group 4 is for further study. |                                                              |                                              |          |
+
+TABLE 2-E/T.521
+
+##### **D-TRANSFER**
+
+| DTAM service parameters                                                                        | Basic and additional session service parameters | Presence in session protocol | Category |
+|------------------------------------------------------------------------------------------------|-------------------------------------------------|------------------------------|----------|
+| Document information                                                                           | Session user data                               | (Note)                       | 1        |
+| Document reference information                                                                 | Document reference number                       | (Note)                       | 1        |
+| NOTE – There is no direct mapping of the D-TRANSFER primitive to one single session primitive. |                                                 |                              |          |
+
+TABLE 2-F/T.521
+
+##### **D-TOKEN PLEASE**
+
+| DTAM service parameters | Basic and additional session service parameters | Presence in session protocol | Category |
+|-------------------------|-------------------------------------------------|------------------------------|----------|
+| None                    | Token                                           | m                            | 2        |
+
+# **6 Document interchange data structures**
+
+The interchange representation of a document has to be defined in accordance with the Recommendation which specifies the relevant document application profile.
+
+# **7 Document transfer**
+
+## **7.1 Synchronization**
+
+The document information is divided into segments, in accordance with 7.3.5/T.433, such that each segment contains a one page descriptor and the associated content portion. A minor synchronization point is associated with each segment.
+
+## **7.2 Document recovery**
+
+For further study.
+
+# **Appendix I (to Recommendation T.521)**
+
+## **Overall Protocol Sequence**
+
+(This appendix does not form an integral part of this Recommendation)
+
+This is an informative appendix for:
+
+- normal procedure;
+- token control procedure;
+- abort procedure;
+- exception report procedure.
+
+![Sequence diagrams for DTAM and Session PM interactions. The left diagram shows the normal procedure from DTAM user to Session PM. The right diagram shows the normal procedure from Session PM to DTAM user. Both diagrams include a central 'Session service provider' label.](4801720824e4b5e2361a5564f91cfb70_img.jpg)
+
+The diagram illustrates the normal procedure for DTAM and Session PM interactions, divided into two parts: DTAM user to Session PM (left) and Session PM to DTAM user (right).
+
+**Left Diagram (DTAM user to Session PM):**
+
+- DTAM user sends **D-INIT-req.** to DTAM PM.
+- DTAM PM sends **S-CON-req.** to Session PM.
+- Session PM sends **S-CON-conf.** to DTAM PM.
+- DTAM PM sends **D-INIT-conf.** to DTAM user.
+- DTAM user sends **D-CAPABILITY-req.** to DTAM PM.
+- DTAM PM sends **S-CAPAB-DATA-req.** to Session PM.
+- Session PM sends **S-CAPAB-DATA-conf.** to DTAM PM.
+- DTAM PM sends **D-CAPABILITY-conf.** to DTAM user.
+- DTAM user sends **D-TRANSFER-req.** to DTAM PM.
+- DTAM PM sends **S-ACT-START-req.** to Session PM.
+- DTAM PM sends **S-DATA-req.** to Session PM.
+- DTAM PM sends **S-SYNC-MIN-req.** to Session PM.
+- Session PM sends **S-SYNC-MIN-conf.** to DTAM PM.
+- DTAM PM sends **S-DATA-req.** to Session PM.
+- DTAM PM sends **S-ACT-END-req.** to Session PM.
+- Session PM sends **S-ACT-END-conf.** to DTAM PM.
+- DTAM PM sends **D-TRANSFER-conf.** to DTAM user.
+- DTAM user sends **D-TERMINATE-req.** to DTAM PM.
+- DTAM PM sends **S-REL-req.** to Session PM.
+- Session PM sends **S-REL-resp.** to DTAM PM.
+- DTAM PM sends **D-TERMINATE-conf.** to DTAM user.
+
+**Right Diagram (Session PM to DTAM user):**
+
+- Session PM sends **S-CON-ind.** to DTAM PM.
+- DTAM PM sends **D-INIT-ind.** to DTAM user.
+- DTAM user sends **D-INIT-resp.** to DTAM PM.
+- DTAM PM sends **S-CON-resp.** to Session PM.
+- Session PM sends **S-CAPAB-DATA-ind.** to DTAM PM.
+- DTAM PM sends **D-CAPABILITY-ind.** to DTAM user.
+- DTAM user sends **D-CAPABILITY-resp.** to DTAM PM.
+- DTAM PM sends **S-CAPAB-DATA-resp.** to Session PM.
+- Session PM sends **S-ACT-START-ind.** to DTAM PM.
+- DTAM PM sends **S-DATA-ind.** to Session PM.
+- Session PM sends **S-SYNC-MIN-ind.** to DTAM PM.
+- DTAM PM sends **S-SYNC-MIN-resp.** to Session PM.
+- Session PM sends **S-DATA-ind.** to DTAM PM.
+- DTAM PM sends **S-SYNC-MIN-ind.** to Session PM.
+- Session PM sends **S-ACT-END-resp.** to DTAM PM.
+- DTAM PM sends **D-TRANSFER-ind.** to DTAM user.
+- DTAM user sends **D-TERMINATE-ind.** to DTAM PM.
+- DTAM PM sends **S-REL-ind.** to Session PM.
+- Session PM sends **S-REL-resp.** to DTAM PM.
+- DTAM PM sends **D-TERMINATE-resp.** to DTAM user.
+
+Both diagrams include a central label: "Session service provider".
+
+Sequence diagrams for DTAM and Session PM interactions. The left diagram shows the normal procedure from DTAM user to Session PM. The right diagram shows the normal procedure from Session PM to DTAM user. Both diagrams include a central 'Session service provider' label.
+
+T0805560-90/d02
+
+FIGURE I.1/T.521  
+Normal procedure
+
+![Sequence diagram for Token control procedure showing interactions between DTAM user, DTAM PM, and Session PM.](33ed1f9b27c7c21c797aa928b0f06851_img.jpg)
+
+```
+
+sequenceDiagram
+    participant DU_L as DTAM user
+    participant DP_L as DTAM PM
+    participant SP_L as Session PM
+    participant SP_R as Session PM
+    participant DP_R as DTAM PM
+    participant DU_R as DTAM user
+
+    Note over SP_L, SP_R: "Session service provider"
+
+    DU_R->>DP_R: D-TOKEN-PLS-req.
+    DP_R->>SP_R: S-TOKEN-PLS-req.
+    SP_L->>DP_L: S-TOKEN-PLS-ind.
+    DP_L->>DU_L: D-TOKEN-PLS-ind.
+
+    DU_L->>DP_L: D-CTRL-GIVE-req.
+    DP_L->>SP_L: S-CTRL-GIVE-req.a)
+    SP_R->>DP_R: S-CTRL-GIVE-ind.
+    DP_R->>DU_R: D-CTRL-GIVE-ind.
+  
+```
+
+T0805570-90/d03
+
+Sequence diagram for Token control procedure showing interactions between DTAM user, DTAM PM, and Session PM.
+
+<sup>a)</sup> This service is not confirmed at the service level, but at the protocol level (refer to Recommendation 7.18.9/X.225).
+
+FIGURE I.2/T.521  
+**Token control procedure**
+
+![Sequence diagram for Abort procedure showing two scenarios of interactions between DTAM user, DTAM PM, and Session PM.](7efae06af3af43ffe5d4b956a679cf54_img.jpg)
+
+```
+
+sequenceDiagram
+    participant DU_L as DTAM user
+    participant DP_L as DTAM PM
+    participant SP_L as Session PM
+    participant SP_R as Session PM
+    participant DP_R as DTAM PM
+    participant DU_R as DTAM user
+
+    Note over SP_L, SP_R: "Session service provider"
+
+    DU_L->>DP_L: D-U-ABORT-req.
+    DP_L->>SP_L: S-U-ABT-req.a)
+    SP_R->>DP_R: S-U-ABT-ind.
+    DP_R->>DU_R: D-U-ABORT-ind.
+
+    Note over SP_L, SP_R: 
+    SP_L->>DP_L: S-P-ABT-ind.
+    DP_L->>DU_L: D-P-ABORT-ind.
+    Note right of SP_L: e.g. T-DISC-ind.
+    SP_R->>DP_R: S-P-ABT-ind.
+    DP_R->>DU_R: D-ABORT-ind.
+  
+```
+
+T0805580-90/d04
+
+Sequence diagram for Abort procedure showing two scenarios of interactions between DTAM user, DTAM PM, and Session PM.
+
+<sup>a)</sup> This service is not confirmed at the service level, but at the protocol level (refer to Recommendation 7.9.3/X.225).
+
+FIGURE I.3/T.521  
+**Abort procedure**
+
+![](fa859e4e468bfb2710a94527f2c504af_img.jpg)
+
+```
+
+sequenceDiagram
+    participant DU1 as DTAM user
+    participant DP1 as DTAM PM
+    participant SP1 as Session PM
+    participant SP2 as Session PM
+    participant DP2 as DTAM PM
+    participant DU2 as DTAM user
+
+    Note over SP1, SP2: "Session service provider"
+    Note right of SP1: Invalid data
+    SP1->>DP1: S-P-EXPT-ind.
+    DP1->>SP1: S-ACT DCAD/INT-req.
+    SP1->>DP1: S-ACT DCAD/INT-conf.
+    DP1->>DU1: D-TRANSFER-conf.
+
+    SP2->>DP2: S-P-EXPT-ind.
+    DP2->>DP2: S-ACT DCAD/INT-ind.
+    DP2->>DU2: D-TRANSFER-ind.
+    DP2->>SP2: S-ACT DCAD/INT-resp.
+
+```
+
+*Session PM Error Detection*
+
+![](5cab96b2d23174c25919840ecd50aa48_img.jpg)
+
+```
+
+sequenceDiagram
+    participant DU1 as DTAM user
+    participant DP1 as DTAM PM
+    participant SP1 as Session PM
+    participant SP2 as Session PM
+    participant DP2 as DTAM PM
+    participant DU2 as DTAM user
+
+    Note over SP1, SP2: "Session service provider"
+    SP1->>DP1: S-U-EXPT-ind.
+    DP1->>SP1: S-ACT DCAD/INT-req.
+    SP1->>DP1: S-ACT DCAD/INT-conf.
+    DP1->>DU1: D-TRANSFER-conf.
+
+    Note right of DP2: Error
+    DP2->>SP2: S-U-EXPT-req.
+    SP2->>DP2: S-ACT DCAD/INT-ind.
+    DP2->>DU2: D-TRANSFER-ind.
+    DP2->>SP2: S-ACT DCAD/INT-resp.
+
+```
+
+*DTAM PM Error Detection*
+
+![](0f985b39edc1d52ba3600c438bc8f0a5_img.jpg)
+
+```
+
+sequenceDiagram
+    participant DU1 as DTAM user
+    participant DP1 as DTAM PM
+    participant SP1 as Session PM
+    participant SP2 as Session PM
+    participant DP2 as DTAM PM
+    participant DU2 as DTAM user
+
+    Note over SP1, SP2: "Session service provider"
+    Note left of DP1: Error
+    DP1->>SP1: S-ACT DCAD/INT-req.
+    SP1->>DP1: S-ACT DCAD/INT-conf.
+    DP1->>DU1: D-TRANSFER-conf.
+
+    SP2->>DP2: S-ACT DCAD/INT-ind.
+    DP2->>DU2: D-TRANSFER-ind.
+    DP2->>SP2: S-ACT DCAD/INT-resp.
+
+```
+
+*DTAM PM Error Detection*
+
+T0805590-90/d05
+
+FIGURE I.4/T.521  
+**Exception report procedure**
+
+# Appendix II (to Recommendation T.521)
+
+# Guidance for mapping of DTAM to Recommendation T.62
+
+(This appendix does not form an integral part of this Recommendation)
+
+## Introduction
+
+This appendix provides an implementor with a guideline when a mapping of a facsimile Group 4 application based on DTAM to Recommendation T.62 is intended.
+
+The main part of Recommendation T.521 defines the basic mapping of DTAM to the session service, described in Recommendation X.215 and Recommendation X.225 in conjunction with Recommendation T.62 *bis*.
+
+For the mapping of DTAM onto the T.62 control procedures, further clarifications and explanations are needed.
+
+The clarifications and explanations are considered within two parts.
+
+Part 1 considering the DTAM to session service mapping, whereas part 2 describes the mapping of DTAM to Recommendation T.62 in terms of using the T.62 session commands and responses.
+
+Figure II.1 depicts the scope of this appendix.
+
+![Figure II.1/T.521: A hierarchical diagram showing the scope of the appendix. At the top is a box labeled 'Fax-G4-Application'. A solid line connects it to a larger box labeled 'DTAM'. Inside the 'DTAM' box is a smaller box labeled 'T.521'. Below the 'T.521' box, a dashed line encloses the text 'Appendix II'. Two solid lines extend downwards from the 'DTAM' box: one from the left side leading to a box labeled 'T.62', and one from the right side leading to a box labeled 'T.62 bis X.215 and X.225'. The identifier 'T0805600-90/d06' is located at the bottom right of the diagram.](90ee16ccc0ad16aeca48087797d7b07f_img.jpg)
+
+```
+graph TD; A[Fax-G4-Application] --- B[DTAM]; subgraph B; C[T.521]; end; B -.- D[Appendix II]; B --- E[T.62]; B --- F["T.62 bis  
+X.215  
+and X.225"]; G[T0805600-90/d06];
+```
+
+Figure II.1/T.521: A hierarchical diagram showing the scope of the appendix. At the top is a box labeled 'Fax-G4-Application'. A solid line connects it to a larger box labeled 'DTAM'. Inside the 'DTAM' box is a smaller box labeled 'T.521'. Below the 'T.521' box, a dashed line encloses the text 'Appendix II'. Two solid lines extend downwards from the 'DTAM' box: one from the left side leading to a box labeled 'T.62', and one from the right side leading to a box labeled 'T.62 bis X.215 and X.225'. The identifier 'T0805600-90/d06' is located at the bottom right of the diagram.
+
+FIGURE II.1/T.521
+
+## II.1 Items to be considered when using DTAM on top of Recommendation T.62
+
+### II.1.1 Mapping of DTAM to the session service
+
+The mapping of DTAM to the session service is described as the “Transparent Mode” within Recommendations T.432 and T.433.
+
+The specific session service parameter mapping is defined in this Recommendation.
+
+With the exception of two cases both are equivalent, the mapping of DTAM to T.62 and the mapping of DTAM to X.215 and X.225 (according to Recommendation T.62 *bis*).
+
+The two exceptions are the S-U-ABORT and the S-CONTROL-GIVE service. Both services are confirmed services within Recommendation T.62, but unconfirmed service according to Recommendation X.215. The terminology of the session service primitives are aligned with the session service according to Recommendation X.215.
+
+In order to guarantee a correct mapping at the DTAM and T.62 interface, an “Adaptation Management Function (AMF)” is introduced to perform this task.
+
+#### II.1.1.1 U-ABORT service
+
+The situation envisaged is as follows.
+
+![Sequence diagrams for S-U-ABORT service mapping between Recommendation X.215 and Recommendation T.62.](9cd90f495b95ad2116ff780248c26d95_img.jpg)
+
+The diagram shows two sequence diagrams side-by-side. The left diagram, titled 'Recommendation X.215', shows a vertical line for the SS-provider. A solid arrow labeled 'S-U-ABORT request' enters from the left, and a solid arrow labeled 'S-U-ABORT indication' exits to the right. The right diagram, titled 'Recommendation T.62', shows two vertical lines. The left line has a solid arrow labeled 'S-U-ABORT request' entering and a solid arrow labeled 'S-U-ABORT confirm' exiting. The right line has a solid arrow labeled 'S-U-ABORT indication' entering and a solid arrow labeled 'S-U-ABORT response' exiting. Dashed horizontal arrows connect the two lines: one from the left line to the right line, and another from the right line to the left line. The reference 'T0805610-90/d07' is at the bottom right.
+
+Sequence diagrams for S-U-ABORT service mapping between Recommendation X.215 and Recommendation T.62.
+
+The DTAM-PM neither knows an S-U-ABORT confirm primitive nor does it issue an S-U-ABORT response primitive. Therefore, the “Adaptation Management Function (AMF)” is responsible for the mapping.
+
+##### II.1.1.1.1 Mapping rules
+
+An S-U-ABORT request from the DTAM-PM is transparently transferred through the AMF to the T.62-PM.
+
+An S-U-ABORT indication generated by the T.62-PM is transparently transferred through the AMF to the DTAM-PM.
+
+An S-U-ABORT response will not be generated by the DTAM-PM. Therefore, the AMF is in charge of generating an S-U-ABORT response primitive to the T.62-PM in the adequate situation (i.e. after the receipt of an S-U-ABORT indication).
+
+An S-U-ABORT confirm is not known by the DTAM-PM. Therefore, the AMF is in charge of ignoring the S-U-ABORT confirm primitive which will be generated by the T.62-PM (i.e. after the receipt of an ABORT ACCEPT (RSAP) SPDU).
+
+#### II.1.1.2 S-CONTROL-GIVE service
+
+The situation envisaged is as follows.
+
+![Sequence diagrams for S-CONTROL-GIVE service mapping between Recommendation X.215 and Recommendation T.62.](dc23d430e878eb71b8cd589984113940_img.jpg)
+
+The diagram shows two sequence diagrams side-by-side. The left diagram, titled 'Recommendation X.215', shows a vertical line for the SS-provider. A solid arrow labeled 'S-CONTROL-GIVE request' enters from the left, and a solid arrow labeled 'S-CONTROL-GIVE indication' exits to the right. The right diagram, titled 'Recommendation T.62', shows two vertical lines. The left line has a solid arrow labeled 'S-CONTROL-GIVE request' entering and a solid arrow labeled 'S-CONTROL-GIVE confirm' exiting. The right line has a solid arrow labeled 'S-CONTROL-GIVE indication' entering and a solid arrow labeled 'S-CONTROL-GIVE response' exiting. Dashed horizontal arrows connect the two lines: one from the left line to the right line, and another from the right line to the left line. The reference 'T0805620-90/d08' is at the bottom right.
+
+Sequence diagrams for S-CONTROL-GIVE service mapping between Recommendation X.215 and Recommendation T.62.
+
+The DTAM-PM neither knows an S-CONTROL-GIVE confirm primitive nor does it issue an S-CONTROL-GIVE response primitive. Therefore, the “Adaptation Management Function (AMF)” is responsible for the mapping.
+
+##### **II.1.1.2.1 Mapping rules**
+
+An S-CONTROL-GIVE request from the DTAM-PM is transparently transferred through the AMF to the T.62-PM.
+
+An S-CONTROL-GIVE indication generated by the T.62-PM is transparently transferred through the AMF to the DTAM-PM.
+
+An S-CONTROL-GIVE confirm is not known by the DTAM-PM. Therefore, the AMF is in charge of ignoring the S-CONTROL-GIVE confirm primitive which will be generated by the T.62-PM (i.e. after the receipt of an S-CONTROL-GIVE indication).
+
+An S-CONTROL-GIVE confirm is not known by the DTAM-PM. Therefore, the AMF is in charge of ignoring the S-CONTROL-GIVE confirm primitive which will be generated by the T.62-PM (i.e. after the receipt of a GIVE TOKENS ACK (RSCCP) SPDU).
+
+### **II.1.2 Use of T.62 commands and responses**
+
+This part of the appendix is related to T.62 session commands and responses in order to point out:
+
+- in which session parameter the application dependent information is transferred;
+- references to Recommendation T.433 where the application relevant information can be found;
+- the use of Recommendation T.62 in relation to multifunctional equipment (e.g. TTX and G4 facsimile);
+- important communication phases.
+
+#### **II.1.2.1 Session establishment (CSS/RSSP)**
+
+For CSS/RSSP the application capabilities within the Session User Data (SUD) parameter shall indicate the document architecture class and the document application profile T.73 which is available as receiving capability of the sender of the command/response.
+
+#### **II.1.2.2 Capability negotiation (CDCL/RDCLP)**
+
+For CDCL, the application capabilities indicated within the SUD, should, beside the document architecture class and document application profile T.73, include a list of optional receiving capabilities, such as non-basic document characteristics and/or non-basic structural characteristics, that may be needed at the receiver by the sender of the command.
+
+For RDCLP, the optional application capabilities available should be indicated.
+
+Multifunctional terminals which may support the Teletex and facsimile Group 4 application shall:
+
+- negotiate options of the basic Teletex document transfer using the non-basic Teletex capabilities PGI and not the SUD PGI;
+- not use the SUD PGI and the non-basic Teletex capabilities PGI together in a single exchange of CDCL/RDCLP (CSS/RSSP).
+
+#### **II.1.2.3 Document transfer (CDS/CDC)**
+
+For CDS/CDC, the application capabilities indicated within the SUD shall include the application capabilities which are required for the document.
+
+Multifunctional terminals which may support Teletex and facsimile Group 4 application shall use the CDS/CDC command as follows:
+
+- when a facsimile Group 4 document is to be sent, the SUD parameter is always contained in the CDS/CDC of the document;
+- when a basic Teletex document is to be sent, the SUD is absent from the CDS/CDC of the document.
+
+The coding of the application capabilities attributes conveyed in the SUD of CSS/RSSP, CDCL/RDCLP are specified in 8.2/T.433; and for the SUD of CDS/CDC it is defined in Figure 3/T.433.
\ No newline at end of file
diff --git a/marked/T/T-REC-T.522-199209-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/T/T-REC-T.522-199209-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..eb549816c6f04c131fc64aa3f6db7ab1c7f24887
--- /dev/null
+++ b/marked/T/T-REC-T.522-199209-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:b6db33a54b73665af753f8340efea7562874e7c73c79f8f1b7ab432fc54cf789
+size 8393
diff --git a/marked/T/T-REC-T.522-199209-I_PDF-E/6ed175c791b5e156d9c98a8dbcc3318c_img.jpg b/marked/T/T-REC-T.522-199209-I_PDF-E/6ed175c791b5e156d9c98a8dbcc3318c_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..2934f6ead1b2619c03d995ade0ad53930fb26f6b
--- /dev/null
+++ b/marked/T/T-REC-T.522-199209-I_PDF-E/6ed175c791b5e156d9c98a8dbcc3318c_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:1ac0a2ef8cbe7a1e3a0197770202f64512035cbd9495c93c9d52857d488b5b5d
+size 6020
diff --git a/marked/T/T-REC-T.522-199209-I_PDF-E/raw.md b/marked/T/T-REC-T.522-199209-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..2f0153fe8f634b30d311633c5ddd9ec7dd9a8aa4
--- /dev/null
+++ b/marked/T/T-REC-T.522-199209-I_PDF-E/raw.md
@@ -0,0 +1,246 @@
+
+
+![ITU logo: a globe with the letters ITU and a lightning bolt.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg)
+
+ITU logo: a globe with the letters ITU and a lightning bolt.
+
+INTERNATIONAL TELECOMMUNICATION UNION
+
+# CCITT
+
+THE INTERNATIONAL  
+TELEGRAPH AND TELEPHONE  
+CONSULTATIVE COMMITTEE
+
+## T.522
+
+(09/92)
+
+**TERMINAL EQUIPMENT AND PROTOCOLS FOR  
+TELEMATIC SERVICES**
+
+---
+
+**COMMUNICATION APPLICATION PROFILE  
+BT1 FOR DOCUMENT BULK TRANSFER**
+
+![CCITT logo: a globe with the letters CCITT.](6ed175c791b5e156d9c98a8dbcc3318c_img.jpg)
+
+CCITT logo: a globe with the letters CCITT.
+
+**Recommendation T.522**
+
+---
+
+# FOREWORD
+
+The CCITT (the International Telegraph and Telephone Consultative Committee) is a permanent organ of the International Telecommunication Union (ITU). CCITT is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis.
+
+The Plenary Assembly of CCITT which meets every four years, establishes the topics for study and approves Recommendations prepared by its Study Groups. The approval of Recommendations by the members of CCITT between Plenary Assemblies is covered by the procedure laid down in CCITT Resolution No. 2 (Melbourne, 1988).
+
+Recommendation T.522 was revised by Study Group VIII and was approved under the Resolution No. 2 procedure on the 18th of September 1992.
+
+# --- CCITT NOTE
+
+In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized private operating agency.
+
+© ITU 1993
+
+All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU.
+
+# CONTENTS
+
+|     |                                                            |
+|-----|------------------------------------------------------------|
+| 0   | <i>Introduction</i>                                        |
+| 1   | <i>Scope and field of application</i>                      |
+| 2   | <i>References</i>                                          |
+| 3   | <i>Definitions</i>                                         |
+| 4   | <i>Abbreviations and conventions</i>                       |
+| 5   | <i>Definition of communication application profile BT1</i> |
+| 5.1 | Overview of BT1                                            |
+| 5.2 | DTAM functional units                                      |
+| 5.3 | DTAM service primitives and parameters                     |
+
+# INTRODUCTION
+
+T.400-Series Recommendations define the open document architecture (T.410-Series Recommendations) and the DTAM services and protocols (T.430-Series Recommendations) for the purpose of the document transfer and manipulation. In order to apply T.400-Series Recommendations to various telematic services, it is necessary to specify the DTAM application profile for each service that consists of a document application profile and a communication application profile.
+
+According to this requirement, T500-Series Recommendations define the document application profiles and T.520-Series Recommendations define the communication application profiles.
+
+Recommendation T.522 is one of a set of T.520-Series Recommendations to define the communication application profile for the document bulk transfer using X.200 environment.
+
+## **Recommendation T.522**
+
+# **COMMUNICATION APPLICATION PROFILE BT1 FOR DOCUMENT BULK TRANSFER**
+
+*(revised 1992)*
+
+# **1 Scope and field of application**
+
+This Recommendation defines the communication application profile for the document bulk transfer in terms of
+
+- a) DTAM functional units used;
+- b) DTAM service primitives and parameters used.
+
+# 2 References
+
+The following references are required in order to implement the communication profile defined in this Recommendation.
+
+- CCITT Recommendation T.431, *Document transfer and manipulation (DTAM) – Service and protocols – Introduction and general principles*.
+- CCITT Recommendation T.432, *Document transfer and manipulation (DTAM) – Service protocols – Service definition*.
+- CCITT Recommendation T.433, *Document transfer and manipulation (DTAM) – Service and protocols – Protocol specification*.
+
+# 3 Definitions
+
+The definitions of T.400-Series Recommendations also apply to this Recommendation.
+
+# 4 Abbreviations and conventions
+
+The abbreviations and conventions defined in T.400-Series Recommendations also apply to this Recommendation.
+
+# 5 Definitions of communication application profile BT1
+
+## 5.1 Overview of BT1
+
+This Recommendation defines functional units and communication support function in accordance with Recommendation T.431.
+
+BT1 uses the document bulk transfer in normal mode (RTSE) as defined in Recommendation T.433.
+
+## 5.2 DTAM functional units
+
+The following functional units defined in Recommendation T.432 are used for BT1:
+
+- association use control (kernel);
+- capability;
+- document bulk transfer;
+- token control.
+
+## 5.3 DTAM service primitives and parameters
+
+General DTAM service definition and parameters are defined in Recommendation T.432. This section specifies the parameters of DTAM service of BT1.
+
+### 5.3.1 D-INITIATE service parameters
+
+The following parameters of this service
+
+- telematic requirements; and
+- application capabilities,
+
+are used as follows (See Table 1/T.522.).
+
+##### 1) Telematic requirements
+
+The following functional units defined in Recommendation T.432 are used for BT1 as mandatory functional units:
+
+- association control (kernel);
+- document bulk transfer;
+
+- token control;
+- capability.
+
+##### 2) *Application capabilities*
+
+This “application capabilities” is defined in Recommendation T.432 and the following sub-parameters are used:
+
+- ODA Application capabilities
+  - a) Document application profile  
+This parameter is used as defined in Recommendation T.432.
+  - b) Non-basic document characteristics  
+This is the “non-basic document characteristics” defined in Recommendation T.432.
+  - c) Non-basic structure characteristics  
+This is the “non-basic structure characteristics” defined in Recommendation T.432.
+- File transfer capabilities
+  - a) BFT capabilities  
+This parameter is used as defined in Recommendation T.432.
+  - b) Transparent data capability  
+This parameter is used as defined in Recommendation T.432.
+
+The Transparent mode service parameter is not used. The other service parameters are used as defined in Recommendation T.432.
+
+TABLE 1/T.522
+
+##### Usage of the Telematic requirements and Application capabilities service parameters for BT1
+
+|                                     | D-INITIATE<br>request | D-INITIATE<br>indication | D-INITIATE<br>response | D-INITIATE<br>confirm |
+|-------------------------------------|-----------------------|--------------------------|------------------------|-----------------------|
+| Telematic requirements              | M                     | M(=)                     | M                      | M(=)                  |
+| Application capabilities            | M                     | M(=)                     | M                      | M(=)                  |
+| — ODA application capabilities      |                       |                          |                        |                       |
+| Document Application profile        | M                     | M(=)                     | M                      | M(=)                  |
+| Non-basic document characteristics  | U                     | C(=)                     | U                      | C(=)                  |
+| Non-basic structure characteristics | U                     | C(=)                     | U                      | C(=)                  |
+| — File transfer capabilities        |                       |                          |                        |                       |
+| BFT capabilities                    | U                     | C(=)                     | U                      | C(=)                  |
+| Transparent data capability         | U                     | C(=)                     | U                      | C(=)                  |
+
+### 5.3.2 *D-TERMINATE service parameters*
+
+This service has no parameter for BT1. Only the initiator can issue D-TERMINATE. In addition, the initiator can issue D-TERMINATE only if he has the data token.
+
+#### 5.3.3 *D-U-ABORT service parameters*
+
+This service has the parameter of “user information”. This parameter is used as defined in Recommendation T.432.
+
+#### 5.3.4 *D-CAPABILITY service parameters*
+
+The following parameter of this service is as follows:
+
+##### - Application capabilities
+
+This “application capabilities” is defined in Recommendation T.432 and the following sub-parameters are used:
+
+##### - ODA application capabilities
+
+##### - a) Document application profile
+
+This parameter is used as defined in Recommendation T.432.
+
+##### - b) Non-basic document characteristics
+
+This is the “non-basic document characteristics” defined in Recommendation T.432.
+
+##### - c) Non-basic structure characteristics
+
+This is the “non-basic structure characteristics” defined in Recommendation T.432.
+
+##### - File transfer capabilities
+
+##### - a) BFT capabilities
+
+This parameter is used as defined in Recommendation T.432.
+
+##### - b) Transparent data capability
+
+This parameter is used as defined in Recommendation T.432.
+
+(See Table 2/T.522.)
+
+TABLE 2/T.522
+
+**Usage of the Application capabilities service parameter for BT1**
+
+|                                       | D-CAPABILITY<br>request | D-CAPABILITY<br>indication | D-CAPABILITY<br>response | D-CAPABILITY<br>confirm |
+|---------------------------------------|-------------------------|----------------------------|--------------------------|-------------------------|
+| Application capabilities              | M                       | M(=)                       | M                        | M(=)                    |
+| — ODA Application capabilities        |                         |                            |                          |                         |
+| Document application profile          | M                       | M(=)                       | M                        | M(=)                    |
+| Non-basic document<br>characteristics | U                       | C(=)                       | U                        | C(=)                    |
+| Non-basic structure characteristics   | U                       | C(=)                       | U                        | C(=)                    |
+| — File transfer capabilities          |                         |                            |                          |                         |
+| BFT capabilities                      | U                       | C(=)                       | U                        | C(=)                    |
+| Transparent data capability           | U                       | C(=)                       | U                        | C(=)                    |
+
+#### 5.3.5 *D-TRANSFER service parameters*
+
+This D-TRANSFER service is used as defined in Recommendation T.432.
+
+#### 5.3.6 *D-CONTROL GIVE service parameters*
+
+This parameter is used as defined in Recommendation T.432.
+
+#### 5.3.7 *D-TOKEN PLEASE service parameters*
+
+The D-TOKEN PLEASE service is used to request the data token. The service has the parameter priority as defined in Recommendation T. 432. BT1 uses the value two (normal priority).
+
+*Note* – Whether a D-CONTROL GIVE request is issued as an answer to a D-TOKEN request is a user option.
\ No newline at end of file
diff --git a/marked/T/T-REC-T.523-199303-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/T/T-REC-T.523-199303-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..6f729ca9c59819e21d2b96ea73fb66c9b637ea7b
--- /dev/null
+++ b/marked/T/T-REC-T.523-199303-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:040a83385dacc2292feb4ebd3a11dff7a2e118799dadc72c5314125fae057105
+size 8251
diff --git a/marked/T/T-REC-T.523-199303-I_PDF-E/a5ee5c23b6dc52ec1d724b76d5a5f58f_img.jpg b/marked/T/T-REC-T.523-199303-I_PDF-E/a5ee5c23b6dc52ec1d724b76d5a5f58f_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..52bd42721cdd4bc591099e62a6c2cacc168480d6
--- /dev/null
+++ b/marked/T/T-REC-T.523-199303-I_PDF-E/a5ee5c23b6dc52ec1d724b76d5a5f58f_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:cd5a34167bf00216175404027f751552a4d050ca4c578bcb5ab5254ff7deda23
+size 69802
diff --git a/marked/T/T-REC-T.523-199303-I_PDF-E/af7916c89a458fdab6c3f443217388ae_img.jpg b/marked/T/T-REC-T.523-199303-I_PDF-E/af7916c89a458fdab6c3f443217388ae_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..e6fe713032466da277c019d7f0cc2b004bdf11c8
--- /dev/null
+++ b/marked/T/T-REC-T.523-199303-I_PDF-E/af7916c89a458fdab6c3f443217388ae_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:e8a68f88d0811a2045b875d15c6b6c1925df4b2e7d07421db765691fd338dfb2
+size 86520
diff --git a/marked/T/T-REC-T.523-199303-I_PDF-E/cfef993dcc8fb513de79eb1f93cf26ae_img.jpg b/marked/T/T-REC-T.523-199303-I_PDF-E/cfef993dcc8fb513de79eb1f93cf26ae_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..0a114fbcd1cc0ce6936c683d94b8893b5b9fbcb5
--- /dev/null
+++ b/marked/T/T-REC-T.523-199303-I_PDF-E/cfef993dcc8fb513de79eb1f93cf26ae_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:fc60d449e14c36fce52cc2423f9a1b8942c8dabb5900ba7b59566bb5d0f8bd57
+size 83561
diff --git a/marked/T/T-REC-T.523-199303-I_PDF-E/d4af765160d04ecef538e5066006dc77_img.jpg b/marked/T/T-REC-T.523-199303-I_PDF-E/d4af765160d04ecef538e5066006dc77_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..ce2d3ef5bd33d0c9ed179e13b73a32b0ad383cb4
--- /dev/null
+++ b/marked/T/T-REC-T.523-199303-I_PDF-E/d4af765160d04ecef538e5066006dc77_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:8f16425fb94be058ed415b3fae4484ee1f98f1b52d87dfac3e996d8ddddc8daf
+size 104743
diff --git a/marked/T/T-REC-T.523-199303-I_PDF-E/e6df2733626a85205c1db682e6259c46_img.jpg b/marked/T/T-REC-T.523-199303-I_PDF-E/e6df2733626a85205c1db682e6259c46_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..031a23546a5b00c136ff511832b944397374ff9d
--- /dev/null
+++ b/marked/T/T-REC-T.523-199303-I_PDF-E/e6df2733626a85205c1db682e6259c46_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:3122a241aa5a358be149ff15237adcece3b7c732cf71ac633f022738bae74ab0
+size 73873
diff --git a/marked/T/T-REC-T.523-199303-I_PDF-E/fc46871d72c65d3381d9201646d23439_img.jpg b/marked/T/T-REC-T.523-199303-I_PDF-E/fc46871d72c65d3381d9201646d23439_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..b52fb0b90c007455392e146485d0b599deefadfc
--- /dev/null
+++ b/marked/T/T-REC-T.523-199303-I_PDF-E/fc46871d72c65d3381d9201646d23439_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:e0decc6f75c376ea1d8ffe161af549ed340b87cb1fc5118409ea51f26f65d5a3
+size 93670
diff --git a/marked/T/T-REC-T.523-199303-I_PDF-E/raw.md b/marked/T/T-REC-T.523-199303-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..84fde697b16c1d03b36e1b95b49aef6338e7e2e8
--- /dev/null
+++ b/marked/T/T-REC-T.523-199303-I_PDF-E/raw.md
@@ -0,0 +1,962 @@
+
+
+![ITU logo: a globe with the letters ITU and a lightning bolt symbol.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg)
+
+ITU logo: a globe with the letters ITU and a lightning bolt symbol.
+
+INTERNATIONAL TELECOMMUNICATION UNION
+
+# ITU-T
+
+TELECOMMUNICATION  
+STANDARDIZATION SECTOR  
+OF ITU
+
+## T.523
+
+(03/93)
+
+**TELEMATIC SERVICES**
+
+**TERMINAL EQUIPMENTS AND PROTOCOLS  
+FOR TELEMATIC SERVICES**
+
+---
+
+**COMMUNICATION APPLICATION  
+PROFILE DM-1 FOR VIDEOTEX  
+INTERWORKING**
+
+**ITU-T Recommendation T.523**
+
+(Previously "CCITT Recommendation")
+
+---
+
+# FOREWORD
+
+The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the International Telecommunication Union. The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis.
+
+The World Telecommunication Standardization Conference (WTSC), which meets every four years, established the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics.
+
+ITU-T Recommendation T.523 was revised by the ITU-T Study Group VIII (1988-1993) and was approved by the WTSC (Helsinki, March 1-12, 1993).
+
+# --- NOTES
+
+1 As a consequence of a reform process within the International Telecommunication Union (ITU), the CCITT ceased to exist as of 28 February 1993. In its place, the ITU Telecommunication Standardization Sector (ITU-T) was created as of 1 March 1993. Similarly, in this reform process, the CCIR and the IFRB have been replaced by the Radiocommunication Sector.
+
+In order not to delay publication of this Recommendation, no change has been made in the text to references containing the acronyms “CCITT, CCIR or IFRB” or their associated entities such as Plenary Assembly, Secretariat, etc. Future editions of this Recommendation will contain the proper terminology related to the new ITU structure.
+
+2 In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+# CONTENTS
+
+|                                                                               | <i>Page</i> |
+|-------------------------------------------------------------------------------|-------------|
+| 1 Scope .....                                                                 | 1           |
+| 2 Field of application .....                                                  | 1           |
+| 3 References .....                                                            | 1           |
+| 4 Definitions .....                                                           | 2           |
+| 5 Overview of communication profile DM-1 .....                                | 2           |
+| 6 Basic communication requirements for DM-1 .....                             | 2           |
+| 6.1 DTAM functionalities .....                                                | 2           |
+| 6.2 ACSE functionalities .....                                                | 3           |
+| 6.3 Presentation functionalities .....                                        | 3           |
+| 6.4 Session functionalities .....                                             | 3           |
+| 7 Communication procedure for DM-1 .....                                      | 3           |
+| 7.1 General communication procedure .....                                     | 3           |
+| 7.2 Application-association establishment .....                               | 4           |
+| 7.3 Application-association terminate and abort .....                         | 4           |
+| 7.4 Data transmission .....                                                   | 4           |
+| 8 Elements of procedure .....                                                 | 10          |
+| 8.1 Application-association establishment .....                               | 10          |
+| 8.2 Application-association termination .....                                 | 12          |
+| 8.3 Application-association abort .....                                       | 13          |
+| 8.4 Data transmission .....                                                   | 13          |
+| 9 Actions of the EH and the LH .....                                          | 16          |
+| 9.1 EH action .....                                                           | 16          |
+| 9.2 LH action .....                                                           | 17          |
+| 9.3 List of permissible actions on VIA structure elements in both hosts ..... | 17          |
+| 10 Object identifier .....                                                    | 18          |
+| Annex A – Abstract syntax definition of videotex specific information .....   | 19          |
+| A.1 Encoding of user information associated with D-INITIATE services .....    | 19          |
+| A.2 Encoding of user information associated with D-ABORT services .....       | 19          |
+
+
+
+# COMMUNICATION APPLICATION PROFILE DM-1 FOR VIDEOTEX INTERWORKING
+
+(Melbourne, 1988; revised at Helsinki, 1993)
+
+# 1 Scope
+
+1.1 The T.400-Series Recommendations generally defines open document architecture (ODA), document architecture operations and DTAM service/protocol for document architecture transfer and manipulation under the telematic communication environment.
+
+1.2 This Recommendation defines a communication application profile DM-1 for document unconfirmed manipulation to specify an interactive communication profile based on DTAM between videotex gateway systems.
+
+1.3 The use of Recommendations X.215, X.225, X.216, X.226, X.217 and X.227 for this communication profile is described in this Recommendation.
+
+## 2 Field of application
+
+2.1 The communication application profile DM-1 enables document manipulation for documents which are represented in accordance with the document application profile defined by Recommendation T.504, and the operational application profile defined by Recommendation T.541.
+
+2.2 The ODA documents that are manipulated should be in formatted form.
+
+2.3 The field of application of this Recommendation is the international videotex interworking service between videotex gateways, representing the external host (EH) and the local host (LH).
+
+2.4 Videotex communication procedure is based on the model defined in this Recommendation in accordance with the Recommendation T.564 which defines gateway characteristics for videotex inter-working.
+
+## 3 References
+
+- Rec. T.101 *International interworking for videotex services*
+- Rec. T.430-Series *Document transfer and manipulation (DTAM)*
+- Rec. T.504 *Document application profile for videotex interworking*
+- Rec. T.541 *Operational application profile for videotex interworking*
+- Rec. T.564 *Gateway characteristics for videotex interworking*
+- Rec. X.215 *Session service definition for open systems interconnection for CCITT applications*
+- Rec. X.225 *Session protocol specification for open systems interconnection for CCITT applications*
+- Rec. X.216 *Presentation service definition for open systems interconnection for CCITT applications*
+- Rec. X.226 *Presentation protocol specification for open systems interconnection for CCITT applications*
+
+- Rec. X.217 *Association control service definition for open systems interconnection for CCITT applications*
+- Rec. X.227 *Association control protocol specification for open systems interconnection for CCITT applications*
+- Rec. X.208 *Specification of abstract syntax notation one (ASN.1)*
+- Rec. X.209 *Specification of basic encoding rules for abstract syntax notation one (ASN.1)*
+
+## 4 Definitions
+
+Terms and their definitions are defined by the Recommendations listed above.
+
+# 5 Overview of communication profile DM-1
+
+**5.1** Communication profile DM-1 defines the communication functionalities which provide a real time remote document manipulation on ODA and operational structure documents by create, delete, modify and call operations between videotex gateways under OSI ACSE and presentation communication support functions (normal mode defined in Recommendation T.432). These operations are the unconfirmed type of manipulation.
+
+**5.2** This profile defines the communication model which consists of the local host DTAM user and the external host DTAM user as illustrated in Figure 1. Either the LH or the EH is capable of managing the initiation and termination of application-association. At the association establishment phase, initial VIA structures are automatically generated in both hosts.
+
+**5.3** The owner of the data token, managed by the DTAM token control function, is able to manipulate ODA and operational structure documents which are directly mapped from VIA operations defined in the Recommendation T.564.
+
+**5.4** The manipulation provides the operations which can be applied to one or more constituents of the ODA document and/or the operational structure. In this profile, these operations do effect addition, deletion or modification of constituent to a document which existed identically between both hosts.
+
+**5.5** When the data token belongs to the LH DTAM user, only modify operations on operational structure are allowed to be used by the LH DTAM user. On the other hand, the EH DTAM user is able to use all of the operations defined in DTAM when it has the data token.
+
+# 6 Basic communication requirements for DM-1
+
+DM-1 is defined under the following OSI communication environment. Mapping rules of DTAM APDUs into/out of the ACSE and presentation layer are used as defined in Recommendation T.433.
+
+## 6.1 DTAM functionalities
+
+The following DTAM functionalities defined in Recommendation T.432 are basic requirements for this communication profile DM-1:
+
+- i) document unconfirmed manipulation by using create, modify, delete and call operations;
+- ii) association use control;
+- iii) token management for dialogue control;
+- iv) typed data transmission.
+
+![A diagram showing the communication architecture between two Interactive videotex systems, A and B. System A contains a Local host - LH (DTAM user) connected to a DTAM service T.432, which is connected to a DTAM entity. System B contains an External host - EH (DTAM user) connected to a DTAM service T.432, which is connected to a DTAM entity. The DTAM entities are connected via DTAM protocol T.433. Both DTAM entities are connected to an ACSE service X.217, which is connected to an ACSE entity. The ACSE entities are connected via ACSE protocol X.227. Both ACSE entities are connected to a PSAP (Presentation Service Access Point) via X.216. The PSAPs are connected to a Presentation entity via X.216. The Presentation entities are connected via X.226: Protocol. Both Presentation entities are connected to a Session entity via X.215. The Session entities are connected via X.225. The diagram is labeled T0818540-94/d01.](fc46871d72c65d3381d9201646d23439_img.jpg)
+
+A diagram showing the communication architecture between two Interactive videotex systems, A and B. System A contains a Local host - LH (DTAM user) connected to a DTAM service T.432, which is connected to a DTAM entity. System B contains an External host - EH (DTAM user) connected to a DTAM service T.432, which is connected to a DTAM entity. The DTAM entities are connected via DTAM protocol T.433. Both DTAM entities are connected to an ACSE service X.217, which is connected to an ACSE entity. The ACSE entities are connected via ACSE protocol X.227. Both ACSE entities are connected to a PSAP (Presentation Service Access Point) via X.216. The PSAPs are connected to a Presentation entity via X.216. The Presentation entities are connected via X.226: Protocol. Both Presentation entities are connected to a Session entity via X.215. The Session entities are connected via X.225. The diagram is labeled T0818540-94/d01.
+
+FIGURE 1/T.523  
+A model of communication application profile DM-1  
+for videotex interworking
+
+## 6.2 ACSE functionalities
+
+The basic functionalities of the association control service element defined by Recommendations X.217 and X.227 are used.
+
+## 6.3 Presentation functionalities
+
+The kernel functional unit is used as defined by Recommendations X.216 and X.226. Recommendations X.208 and X.209 are used for the definition of abstract notation and basic encoding rules of abstract notation respectively for DM-1.
+
+## 6.4 Session functionalities
+
+The kernel functional unit, two ways alternate functional unit and typed data functional unit are used in accordance with Recommendations X.215 and X.225.
+
+# 7 Communication procedure for DM-1
+
+## 7.1 General communication procedure
+
+The general communication procedure for videotex gateway application is defined in line with the basic procedure in Recommendation T.432. The procedure consists of:
+
+- application-association establishment;
+- application-association termination;
+
+- application-association abort;
+- data transmission.
+
+## **7.2 Application-association establishment**
+
+A communication normally begins with the establishment of application-association from the LH or EH DTAM user to initialize the communication environment and to set the initial parameters and the VIA structures being used. The initial data token is assigned to the EH DTAM user. After the establishment of application-association, both DTAM users move to the data transmission phase.
+
+## **7.3 Application-association terminate and abort**
+
+The DTAM application-association may be normally terminated by either the LH or the EH DTAM user subject to the owning of the data token. The DTAM application-association may also be abruptly terminated by either the LH or the EH DTAM user or provider using the appropriate DTAM abort services.
+
+## **7.4 Data transmission**
+
+### **7.4.1 General**
+
+Videotex gateway application provides the following communication functions in the data transmission phase:
+
+- 1) manipulation of display information;
+- 2) manipulation of data entry information;
+- 3) manipulation of application control memory information;
+- 4) manipulation of special terminal facilities information;
+- 5) manipulation of administrative information;
+- 6) exchange of over limit information (for further study);
+- 7) transmission of asynchronous message.
+
+### **7.4.2 Manipulation of display information**
+
+Display is performed by VIA operations, defined in Recommendation T.564, initiated by the external host on the display structure.
+
+To perform VIA operations on the display structure the EH uses D-CREATE, D-MODIFY, D-DELETE or D-CALL service primitives under data token control.
+
+### **7.4.3 Manipulation of data entry information**
+
+#### **7.4.3.1 General**
+
+Recommendation T.564 defines the following four types of data entry:
+
+- 1) data entry type 1 – information retrieval;
+- 2) data entry type 2 – data collection;
+- 3) data entry type 3 – data entry on the fly;
+- 4) data entry type 4 – duplex data entry.
+
+These data entry types are categorized into half duplex mode (data entry type 1, 2 and 3) and duplex mode (data entry type 4).
+
+The EH may use D-CREATE, D-MODIFY, D-DELETE, D-CALL to perform VIA operations on each structure element of the data entry structure, except modifying the RESULT-SE and its associated content portion.
+
+*Half duplex mode* of data entry provides the dialogues between the LH and the EH under the data token control. Data entry is performed from the LH by VIA operations via DTAM manipulation (D-MODIFY) on the data entry structure. In this case the EH should give the data token to the LH to perform data entry.
+
+*Duplex mode* of data entry is not dependent upon the token control. Data entry is performed from the LH by the use of typed data and the data token is always located at the EH side.
+
+#### **7.4.3.2 Management of data entry mode**
+
+The management of the data entry modes is bound to the following rule:
+
+- i) The LH issues the parameter of “data entry mode” to indicate the data entry capabilities at the LH side in the DTAM association establishment phase. This parameter is a choice of
+  - a) half duplex mode
+  - b) duplex mode and
+  - c) half duplex and duplex modes.
+- ii) the EH recognizes the capabilities of data entry mode which is capable to be managed by the LH. It is not necessary to inform the LH of the EH capabilities of the data entry mode;
+- iii) if the LH indicates the only half duplex mode and selects the application based on the duplex mode, the EH may refuse to connect with the selected application from the LH;
+- iv) if the LH indicates the only duplex mode and selects the application based on the half duplex mode, the EH may refuse to connect with the selected application from the LH;
+- v) if the LH indicates both modes, all the applications based on the half duplex or duplex modes are available to the LH.
+
+#### **7.4.3.3 Operation of data entry in half duplex mode (type 1, 2, 3)**
+
+In data entry type 1 or 3, the entered data are sent from the LH to the EH using D-MODIFY for the RESULT-SE and the content portion associated to the RESULT-SE. In data entry type 2, the entered data are sent from the LH to the EH using D-MODIFY for the RESULT-SE and the content portions associated with the entered fields and the RESULT-SE (if necessary).
+
+The EH gives the token to the LH to enable the LH to send the entered data.
+
+The LH gives the token to the EH after having completed the data entry (i.e. after having initiated the appropriate D-MODIFY corresponding to the SEs concerned with data entry). Examples are given in Figures 2 and 3.
+
+#### **7.4.3.4 Operation of data entry in duplex mode (type 4)**
+
+When the data entry type attribute of the DATA-ENTRY-PROGRAM-SE is set the data entry type 4, the LH sends the entered data and the termination reason in D-TYPED-DATA with the termination reason associated. The data token remains assigned to the EH. An example is given in Figure 4.
+
+When the EH resets the data entry type attribute to another type (1, 2 or 3) under the condition that both modes are available at the LH, the LH stops sending data in D-TYPED-DATA and uses again D-MODIFY to send the entered data. The EH ignores the possible colliding D-TYPED-DATA.
+
+![Sequence diagram for data entry in type 1 or 3 (half duplex).](a5ee5c23b6dc52ec1d724b76d5a5f58f_img.jpg)
+
+This sequence diagram illustrates the communication flow for data entry in type 1 or 3 (half duplex). The participants are: User's terminal, Local host, DTAM service provider, External host, and Data base.
+
+**Sequence of Events:**
+
+- Initial State:** The system is ready for data entry.
+- DTAM service provider to External host:** D-MODIFY req
+- External host to Local host:** D-MODIFY req
+- Local host to User's terminal:** D-MODIFY ind
+- User's terminal to Local host:** D-MODIFY ind
+- DTAM service provider to External host:** D-TOKEN-GIVE req
+- External host to Local host:** D-TOKEN-GIVE ind
+- Local host to User's terminal:** D-TOKEN-GIVE ind
+- User's terminal to Local host:** D-MODIFY req
+- Local host to DTAM service provider:** D-TOKEN-GIVE req
+- DTAM service provider to External host:** D-MODIFY ind
+- External host to Local host:** D-TOKEN-GIVE ind
+- Local host to User's terminal:** D-MODIFY req
+- User's terminal to Local host:** D-MODIFY ind
+- DTAM service provider to External host:** D-MODIFY req
+- External host to Local host:** D-MODIFY ind
+- Local host to User's terminal:** D-MODIFY ind
+- User's terminal to Local host:** D-MODIFY ind
+
+**Annotations:**
+
+- Displays information:** Corresponds to the first D-MODIFY ind from the Local host to the User's terminal.
+- User's response:** Corresponds to the D-TOKEN-GIVE req from the Local host to the DTAM service provider.
+- Sends information:** Corresponds to the D-MODIFY req from the External host to the Data base.
+- Sends the next information:** Corresponds to the D-MODIFY req from the External host to the Data base.
+
+T0818550-94/d02
+
+Sequence diagram for data entry in type 1 or 3 (half duplex).
+
+FIGURE 2/T.523
+
+**Example of data entry in type 1 or 3**  
+(Information retrieval or on the fly: half duplex)
+
+![Sequence diagram for data entry in type 2 (half duplex).](e6df2733626a85205c1db682e6259c46_img.jpg)
+
+This sequence diagram illustrates the communication flow for data entry in type 2 (half duplex). The participants are: User's terminal, Local host, DTAM service provider, External host, and Data base.
+
+**Sequence of Events:**
+
+- Initial State:** The system is ready for data entry.
+- DTAM service provider to External host:** D-CREATE req
+- External host to Local host:** D-MODIFY req
+- Local host to User's terminal:** D-CREATE ind
+- User's terminal to Local host:** D-MODIFY ind
+- DTAM service provider to External host:** D-TOKEN-GIVE req
+- External host to Local host:** D-TOKEN-GIVE ind
+- Local host to User's terminal:** D-TOKEN-GIVE ind
+- User's terminal to Local host:** D-MODIFY req
+- Local host to DTAM service provider:** D-MODIFY req
+- DTAM service provider to External host:** D-MODIFY ind
+- External host to Local host:** D-MODIFY ind
+- Local host to User's terminal:** D-TOKEN-GIVE req
+- User's terminal to Local host:** D-TOKEN-GIVE ind
+- DTAM service provider to External host:** D-MODIFY req
+- External host to Local host:** D-MODIFY ind
+- Local host to User's terminal:** D-MODIFY ind
+- User's terminal to Local host:** D-MODIFY ind
+
+**Annotations:**
+
+- Displays the form:** Corresponds to the D-CREATE ind from the Local host to the User's terminal.
+- Fills the form:** Corresponds to the D-MODIFY req from the Local host to the DTAM service provider.
+- Sends a form:** Corresponds to the D-CREATE req from the External host to the Data base.
+- Sends the requested information:** Corresponds to the D-MODIFY req from the External host to the Data base.
+
+T0818560-94/d03
+
+Sequence diagram for data entry in type 2 (half duplex).
+
+FIGURE 3/T.523
+
+**Example of data entry in type 2**  
+(Data collection: half duplex)
+
+![Sequence diagram showing data entry in type 4 (Duplex) between User's terminal, Local host, DTAM service provider, External host, and Data base.](cfef993dcc8fb513de79eb1f93cf26ae_img.jpg)
+
+```
+
+sequenceDiagram
+    participant UT as User's terminal
+    participant LH as Local host
+    participant DTAM as DTAM service provider
+    participant EH as External host
+    participant DB as Data base
+
+    EH->>DTAM: D-CREATE req
+    DTAM->>LH: D-CREATE ind
+    LH->>UT: Displays the page
+    EH->>DTAM: D-MODIFY req
+    DTAM->>LH: D-MODIFY ind
+    EH->>DTAM: D-MODIFY req
+    DTAM->>LH: D-MODIFY ind
+    DB-->>EH: Sends a page
+
+    UT->>LH: User's response
+    LH->>DTAM: D-TYPED-DATA req
+    DTAM->>EH: D-TYPED-DATA ind
+    EH->>DTAM: D-MODIFY req
+    DTAM->>LH: D-MODIFY ind
+    DB-->>EH: Sends a page
+
+    UT->>LH: Anticipated user's response
+    LH->>DTAM: D-TYPED-DATA req
+    DTAM->>EH: D-MODIFY req
+    EH->>DTAM: D-MODIFY req
+    DTAM->>LH: D-MODIFY ind
+    DTAM->>EH: D-TYPED-DATA ind
+    EH->>DTAM: D-MODIFY req
+    DTAM->>LH: D-MODIFY ind
+    Note right of DB: Analyses the received information,  
+decides to stop sending the current page  
+Sends another page
+  
+```
+
+The diagram illustrates the sequence of events for data entry in type 4 (Duplex) mode. It involves five entities: User's terminal, Local host, DTAM service provider, External host, and Data base. The process involves various primitives like D-CREATE, D-MODIFY, and D-TYPED-DATA being exchanged to manage page display and user input. The Data base sends pages and analyzes received information to control the flow.
+
+Sequence diagram showing data entry in type 4 (Duplex) between User's terminal, Local host, DTAM service provider, External host, and Data base.
+
+FIGURE 4/T.523
+
+##### **Example of data entry in type 4 (Duplex)**
+
+#### 7.4.3.5 Switching of entry type
+
+The entry type is modified by the EH when sending a D-MODIFY, D-CREATE, D-DELETE or D-REBUILD for the DATA-ENTRY-PROGRAM-SE.
+
+After sending such a D-MODIFY, the EH may send further VIA operations via DTAM manipulation, if required, and should send the token, even when switching to data entry type 4, in order to indicate to the LH the end of entry type redefinition and to permit echoing of characters (if any).
+
+When receiving a primitive which redefines the data-entry type, the LH should stop sending information and consider all information from the videotex user as typed ahead information. The sending of information is resumed when receiving the data token. If the new defined data entry type is 1, 2 or 3, the token remains assigned to the LH until the entry is entirely performed. If the new defined data entry type is 4, the token is immediately sent back to the EH.
+
+The echoing of characters is started after the reception of the data token depending on the value of the echo attribute. The echoing is stopped in modes 1, 2, 3 when sending back the data token after completion of the data entry. The echoing is only stopped in mode 4 after redefinition of a new data entry mode (or modification of the echo attribute).
+
+Examples are given in Figures 5 and 6.
+
+![Sequence diagram showing the interaction between User's terminal, Local host, DTAM service provider, External host, and Data base during a mode switch. The diagram shows message flows like D-MODIFY req/ind and D-TOKEN-GIVE req/ind across these entities, categorized by 'Type 1, 2 or 3' and 'Type 4' modes.](d4af765160d04ecef538e5066006dc77_img.jpg)
+
+```
+
+sequenceDiagram
+    participant UT as User's terminal
+    participant LH as Local host
+    participant DSP as DTAM service provider
+    participant EH as External host
+    participant DB as Data base
+
+    Note over UT, DB: Type 1, 2 or 3
+    EH->>DB: D-MODIFY req
+    Note right of DB: Define type 1, 2, 3
+    EH->>DB: D-MODIFY req
+    Note right of DB: Other modifications
+    EH->>DB: D-MODIFY req
+    EH->>DB: D-TOKEN-GIVE req
+    Note right of DB: End of type definition
+    DSP->>LH: D-MODIFY ind
+    Note left of UT: Stops execution of entry program
+    DSP->>LH: D-MODIFY ind
+    DSP->>LH: D-MODIFY ind
+    DSP->>LH: D-TOKEN-GIVE ind
+    Note left of UT: Resumes
+
+    Note over UT, DB: Type 1, 2 or 3
+    Note left of UT: User's response
+    LH->>DSP: D-MODIFY req
+    LH->>DSP: D-TOKEN-GIVE req
+    DSP->>EH: D-MODIFY ind
+    Note right of DB: Define type 4
+    DSP->>EH: D-TOKEN-GIVE ind
+    EH->>DB: D-MODIFY req
+    Note right of DB: Other modification
+    EH->>DB: D-MODIFY req
+    EH->>DB: D-MODIFY req
+    EH->>DB: D-TOKEN-GIVE req
+    Note right of DB: End of type definition
+    DSP->>LH: D-MODIFY ind
+    Note left of UT: Stops execution of entry program
+    DSP->>LH: D-MODIFY ind
+    Note left of UT: Type ahead authorized
+    DSP->>LH: D-MODIFY ind
+    DSP->>LH: D-TOKEN-GIVE ind
+    Note left of UT: Resumes
+    LH->>DSP: D-TOKEN-GIVE req
+
+    Note over UT, DB: Type 4
+    DSP->>EH: D-TOKEN-GIVE ind
+    Note right of DB: T0818580-94/d05
+
+```
+
+Sequence diagram showing the interaction between User's terminal, Local host, DTAM service provider, External host, and Data base during a mode switch. The diagram shows message flows like D-MODIFY req/ind and D-TOKEN-GIVE req/ind across these entities, categorized by 'Type 1, 2 or 3' and 'Type 4' modes.
+
+FIGURE 5/T.523  
+**Example of mode switch**
+
+### 7.4.4 Manipulation of application control memory information
+
+The EH manipulates the application control memory information which is represented in accordance with the application control memory SE and its subordinates SEs defined in Recommendation T.564 via the DTAM document manipulation services in order to record the sequence of VIA operations to be repeatedly invoked. This transmission should be done under the token control.
+
+### 7.4.5 Manipulation of special terminal facilities information
+
+The EH manipulates the special terminal facilities information which is represented in accordance with the application special terminal facilities SE and its subordinate SEs defined in Recommendation T.564 via the DTAM document manipulation services in order to set the special terminal facilities such as characters of DRCS. This transmission should be done under the token control.
+
+![Sequence diagram showing the mode switch process between User's terminal, Local host, DTAM service provider, External host, and Data base. The diagram illustrates the flow of D-CREATE, D-MODIFY, D-TYPED-DATA, and D-TOKEN-GIVE requests and indications across these components, including a period where the User's terminal stops execution and later resumes.](af7916c89a458fdab6c3f443217388ae_img.jpg)
+
+The diagram illustrates the mode switch process across five components: User's terminal, Local host, DTAM service provider, External host, and Data base. The process is divided into three main phases: 'Stops execution of entry program', 'Type ahead authorized', and 'Resumes'.
+
+- Stops execution of entry program:**
+  - The Local host sends D-CREATE ind, D-MODIFY ind, and D-MODIFY ind to the DTAM service provider.
+  - The DTAM service provider (Type 4) sends D-CREATE req, D-MODIFY req, and D-MODIFY req to the External host.
+  - The External host sends D-MODIFY req to the Data base.
+  - The Data base sends 'Define type 1, 2 or 3' to the External host.
+  - The External host sends D-TYPED-DATA ind to the DTAM service provider.
+  - The DTAM service provider sends D-MODIFY ind to the Local host.
+- Type ahead authorized:**
+  - The Local host sends D-MODIFY ind, D-MODIFY ind, and D-MODIFY ind to the DTAM service provider.
+  - The DTAM service provider sends D-MODIFY req, D-MODIFY req, and D-TOKEN-GIVE req to the External host.
+  - The External host sends D-MODIFY req to the Data base.
+  - The Data base sends 'End of type definition' to the External host.
+- Resumes:**
+  - The Local host sends D-TOKEN-GIVE ind to the DTAM service provider.
+  - The DTAM service provider (Type 1, 2 or 3) sends D-MODIFY req to the External host.
+  - The External host sends D-MODIFY ind to the Data base.
+
+DTAM service provider is labeled as Type 4 at the top and Type 1, 2 or 3 at the bottom.
+
+Sequence diagram showing the mode switch process between User's terminal, Local host, DTAM service provider, External host, and Data base. The diagram illustrates the flow of D-CREATE, D-MODIFY, D-TYPED-DATA, and D-TOKEN-GIVE requests and indications across these components, including a period where the User's terminal stops execution and later resumes.
+
+FIGURE 6/T.523  
+Example of mode switch
+
+### 7.4.6 Manipulation of administrative information
+
+The EH manipulates administrative information which is represented in accordance with the administrative SE and its subordinate SEs defined in Recommendation T.564 via the DTAM document manipulation services in order to manage the accounting and the identification aspects. This transmission should be done under the token control.
+
+NOTE – Administrative information is for further study in the Recommendation T.564.
+
+### 7.4.7 Exchange of over limit information
+
+The exchanging over limit information is for further study.
+
+### 7.4.8 Transmission of asynchronous message
+
+The EH transmits the asynchronous message indicting the warnings (e.g. “close host within 5 minutes”) to the LH. The transmission of this message is not dependent of the data token and the message is conveyed by the DTAM TYPED-DATA service.
+
+# **8 Elements of procedure**
+
+## **8.1 Application-association establishment**
+
+### **8.1.1 General**
+
+Either the LH or the EH establishes an application-association in accordance with the D-INITIATE service described in Recommendation T.432. The purpose of the application-association establishment is:
+
+- to identify the remote peer videotex hosts;
+- to exchange the videotex application capabilities such as document application profile;
+- to implicitly set the initial VIA between peer videotex hosts.
+
+### **8.1.2 Service primitives used**
+
+The following D-INITIATE service primitives, defined in Recommendation T.432, are used:
+
+- D-INITIATE request;
+- D-INITIATE indication;
+- D-INITIATE response;
+- D-INITIATE confirm.
+
+### **8.1.3 D-INITIATE service parameters**
+
+The service parameters defined in Table 2/T.432 are basically used. The semantics of these parameters are given below. The use of the parameters which are not defined in this Recommendation but listed in Table 2/T.432 is bound to the Recommendation X.217 or X.216.
+
+#### *1) Telematic requirements*
+
+The following functional units defined in Recommendation T.432 are used:
+
+- kernel (association control);
+- typed data transfer;
+- document unconfirmed manipulation;
+- token management.
+
+If the telematic requirements proposed by the LH are not acceptable to the EH, the videotex application-association establishment fails by responding with a "reject" result parameter.
+
+#### *2) Application capabilities*
+
+This parameter contains the following sub-parameters:
+
+###### *a) Document application profile*
+
+The value of this parameter is an object identifier which indicates the document application profile being used. Its value is 0 1 8 16 0 (object identifier).
+
+###### *b) Operational application profile*
+
+The value of this parameter is an object identifier which indicates the operational application profile being used. Its value is 0 1 8 16 2 (object identifier).
+
+#### 3) *Account*
+
+The use of the account parameter depends on the ongoing work of CCITT Study Group I on this topic.
+
+#### 4) *Result*
+
+The field can take one of the following symbolic values:
+
+- accepted;
+- rejected by responder (reason-not-specified);
+- rejected by responder (applicationCapabilities-not-supported);
+- rejected by responder (protocolVersion-not-supported);
+- rejected by responder (application-context-name-not-supported);
+- rejected by responding DTAM-PM.
+
+#### 5) *Vi-Initiate-Information (Vi-Init-Information)*
+
+This is the user information associated with the initiation of application association. This contains the following parameters:
+
+###### a) *Videotex interworking protocol version*
+
+This parameter identifies the version of videotex interworking protocol being used. The value is represented by bit string.
+
+##### b) *Inactivity timer*
+
+This parameter identifies the time for inactive period to terminate the videotex application-association because of its inactivity. The value of this parameter is subject to the agreement between both hosts. If the values which are exchanged are different from each other, the value which is indicated by the EH is in effect for that association.
+
+##### c) *Data entry mode*
+
+This parameter identifies the capabilities of the data entry modes to indicate to the peer host. Normally, this parameter is issued by the LH, and may not be used by the EH. The value is represented by integers 1, 2 and 3 which means half-duplex data entry mode, duplex data entry mode and half-duplex/duplex data entry modes respectively.
+
+##### d) *Bilateral management*
+
+This attribute is reserved for information which is exchanged between the two gateways and can be based on bilateral agreement.
+
+The Vi-Init-information described by the ASN.1 is defined in Annex A.
+
+#### 6) *Called application entity title*
+
+This parameter, which is composed of a called application-process title and a called application-entity qualifier, is used as defined in Recommendation X.217. This identifies the external-host-identifier or the local-host-identifier.
+
+#### 7) *Calling application entity title*
+
+This parameter, which is composed of a calling application-process title and a calling application-entity qualifier, is used as defined in Recommendation X.217. This identifies the local-host-identifier or the external-host-identifier.
+
+#### 8) *Application context name*
+
+This parameter is used as defined in Recommendation X.217. The initiator of the application-association shall propose one of the application-contexts for the videotex interworking (see Recommendation T.101) in the D-INITIATE request primitive. The responder shall either accept the application-context proposed by the initiator and return the same value of this parameter in the D-INITIATE response primitive, or shall return a result parameter with the value “rejected (permanent)” and a diagnostic parameter with the value “application context name not supported”.
+
+#### 9) *Presentation context list*
+
+The presentation context definition list comprises a presentation-context-definition for each abstract-syntax included in the application-context, i.e. one each for the videotex interworking, the DTAM and the ACSE. A presentation-context-definition comprises a presentation-context-identifier and an abstract-syntax-name for the ASE.
+
+### **8.1.4 DTAM-PM parameters**
+
+DTAM-PM parameters are set by the DTAM-PM to D-INITIATE and D-INITIATE PDUs indicating the characteristics of DTAM-PM as follows. These parameters are not issued by the LH and the EH, but are generated by the protocol machines when required:
+
+#### 1) *DTAM protocol version*
+
+DTAM protocol version parameter identifies the version of DTAM protocol being used. The value is represented by bit string (0) which means version-1.
+
+#### 2) *Storage capacity*
+
+The storage capacity parameter identifies the memory size which is available to the DTAM-PM. This parameter is exchanged independently from both directions in order to indicate the own memory size.
+
+### **8.1.5 Initial VIA**
+
+The following VIA structure elements (SEs) are implicitly created in both hosts at the videotex application-association establishment. The videotex communication starts with the initial VIA to manipulate for the videotex dialogue between the LH and the EH:
+
+- DOCUMENT-SE;
+- DATA-ENTRY-SE;
+- APPLICATION-CONTROL-MEMORY-SE;
+- ADMINISTRATIVE-INFORMATION-SE;
+- SPECIAL-TERMINAL-FACILITIES-SE.
+
+## **8.2 Application-association termination**
+
+### **8.2.1 General**
+
+Either the LH or the EH requests a normal termination of current videotex application-association in accordance with the D-TERMINATE service described in Recommendation T.432.
+
+### **8.2.2 Service primitives used**
+
+The following D-TERMINATE service primitives, defined in Recommendation T.432, are used:
+
+- D-TERMINATE request;
+- D-TERMINATE indication;
+- D-TERMINATE response;
+- D-TERMINATE confirm.
+
+### 8.2.3 D-TERMINATE service parameters
+
+The D-TERMINATE service parameters are for further study.
+
+## 8.3 Application-association abort
+
+### 8.3.1 General
+
+The LH or the EH requests an abrupt termination of the ongoing videotex application-association in accordance with the D-ABORT service described in Recommendation T.432.
+
+### 8.3.2 Service primitive used
+
+The following D-ABORT service primitives, defined in Recommendation T.432, are used:
+
+- D-ABORT request;
+- D-ABORT indication.
+
+### 8.3.3 D-ABORT service parameters
+
+The following service parameter is used as defined in the Recommendation T.432.
+
+#### 1) *Vi-Abort-Information*
+
+This parameter is the user information associated with the abort of application association and contains the following sub-parameter:
+
+- *Error-code*
+
+This parameter indicates the reason of the abort.
+
+##### a) Error-Report-To-Local-Host attributes (issued by the EH):
+
+- inactivity time-out;
+- unrecoverable errors.
+
+##### b) Error-Report-To-External-Host attributes (issued by the LH):
+
+- unrecoverable errors
+
+The Vi-abort-information described by ASN.1 is defined in Annex A.
+
+## 8.4 Data transmission
+
+The data transmission procedure is realized by DTAM document manipulation service and typed data service. Document manipulation service should be invoked under the token control by using DTAM token document manipulation, data token control and typed data services for videotex gateway application.
+
+### 8.4.1 Document manipulation procedure
+
+#### 8.4.1.1 General
+
+VIA operations, defined in Recommendation T. 564, should be directly mapped into the relevant DTAM document manipulation services, D-CREATE, D-MODIFY, D-DELETE and D-CALL services defined in Recommendation T.432. These services provide the following communication functions:
+
+- manipulation of display structure information;
+- manipulation of data entry structure information;
+- manipulation of application control memory information;
+- manipulation of special terminal facilities information;
+
+- manipulation of administrative information (for further study);
+- exchange of over limit information (for further study).
+
+NOTE – The use of D-REBUILD service is for further study.
+
+#### **8.4.1.2 Service primitives used**
+
+The following D-CREATE, D-DELETE, D-MODIFY and D-CALL service primitives defined in Recommendation T.432, are used:
+
+- D-CREATE request;
+- D-CREATE indication;
+- D-DELETE request;
+- D-DELETE indication;
+- D-MODIFY request;
+- D-MODIFY indication;
+- D-CALL request;
+- D-CALL indication.
+
+NOTE – The use of these service primitives bounds to the rule defined in clause 9.
+
+The above document manipulation is managed under the token control by using the following D-TOKEN-PLEASE and D-TOKEN-GIVE service primitives:
+
+- D-TOKEN-PLEASE request;
+- D-TOKEN-PLEASE indication;
+- D-TOKEN-GIVE request;
+- D-TOKEN-GIVE indication.
+
+#### **8.4.1.3 Service parameters for document manipulation**
+
+##### **8.4.1.3.1 D-CREATE service parameters**
+
+- *Create information*
+
+This parameter consists of a sequence of objects as defined in Recommendations T.504 and T.541.
+
+NOTE – If the object identifier carried by the create operation does already exist in the structure, the relevant object in the structure and all subordinates are deleted and the create operation is executed.
+
+##### **8.4.1.3.2 D-DELETE service parameters**
+
+- *Delete information*
+
+This parameter consists of a sequence of object or class identifiers, content portion identifiers and operation elements identifiers and defined in Recommendations T.504 and T.541.
+
+NOTE – If the object identifier carried by the operation does not exist in the structure, the delete operation is ignored.
+
+##### **8.4.1.3.3 D-MODIFY service parameters**
+
+- *Modify information*
+
+This parameter is a sequence of objects as defined in Recommendations T.504 and T.541.
+
+NOTE – If the object identifier carried by the operation does not exist in the structure, the modify operation is ignored.
+
+##### 8.4.1.3.4 D-CALL service parameters
+
+- *Call information*
+
+This parameter is a sequence of choices of current object identifiers which are defined in Recommendation T.541. The CALL information consists of the designation of a RECORD-SE in the application control memory structure element as defined in Recommendation T.564. This record contains the VIA operations.
+
+### 8.4.2 Data token control procedure
+
+#### 8.4.2.1 General
+
+Document manipulation services are invoked under the data token control provided by the DTAM token control function, and the owner of the data token has the right to manipulate the VIA.
+
+#### 8.4.2.2 Dialogue rules
+
+The dialogue between the LH and the EH is bound by the following rules:
+
+- 1) The initial data token is set to the EH at the videotex application-association establishment.
+- 2) The data token may be given by the EH to the LH at the end of a sequence of VIA manipulations in order to enable the LH to send the entered data in the data entry types 1, 2 or 3.
+- 3) In the data entry types 1, 2 or 3 the LH gives the data token to the EH after having sent the sequence of VIA manipulations corresponding to the entered data.
+- 4) If the data token is not owned by the LH or EH, that host may issue the D-TOKEN PLEASE to request the data token. The host which receives the D-TOKEN PLEASE may or may not react on the D-TOKEN PLEASE.
+- 5) In the data entry type 4, the EH may send the token to the LH in order to switch to data entry types 1, 2 or 3 (see 7.4.3.3).
+
+#### 8.4.2.3 D-TOKEN GIVE service parameters
+
+D-TOKEN GIVE service has no parameters.
+
+#### 8.4.2.4 D-TOKEN PLEASE service parameters
+
+- Tokens priority
+
+This parameter defines the priority of the action, governed by the data token, that the requestor of the D-TOKEN PLEASE service wishes to carry out. This parameter has to be supplied by the requestor of the D-TOKEN PLEASE service.
+
+### 8.4.3 TYPED-DATA transmission
+
+#### 8.4.3.1 General
+
+Typed data transmission is used independent of the data token and is issued from both hosts (DTAM users) when required. This procedure may be used for the transmission of warning message indicating the warning from the EH and for the transmission of the user entered data in data entry type 4 from the LH.
+
+#### 8.4.3.2 Service primitives used
+
+The following D-TYPED-DATA service primitives, defined in Recommendation T.432, are used:
+
+- D-TYPED-DATA request;
+- D-TYPED-DATA indication.
+
+#### 8.4.3.3 D-TYPED-DATA service parameters
+
+This is the octet string information which represents the following ViTypedData:
+
+```
+ViTypedData ::= CHOICE {
+    asyncMessage [0] IMPLICIT INTEGER
+        {
+            warnTimeout 0),
+            serviceClose1Minute (1),
+            serviceClose5Minutes (2) },
+    -- Other values are for further study.
+    entryResponse 1] IMPLICIT EntryResponse }
+entryResponse ::= SEQUENCE {
+    [0] IMPLICIT Termination-Reason,
+    -- identical with the coding of termination reason in RESULT-SE
+    [1] IMPLICIT Operational-Content-Type OPTIONAL,
+    -- identical with the coding of operational content-type of RESULT-SE
+    [2] IMPLICIT OCTET STRING OPTIONAL
+    -- identical with operational-element-content }
+```
+
+### 8.4.4 Order of the VIA-DTAM manipulation
+
+The order of the VIA operations via DTAM manipulation (VIA-DTAM manipulation for short) is basically followed by the interchange data format defined in Recommendations T.504 and T.541. That is, in principle, VIA should be manipulated from the higher order of structure element, however, the order of display information represented by ODA and the other videotex specific information represented by operational structure is dependent of the local rule and is not defined in this Recommendation.
+
+The following exceptional order of the VIA-DTAM manipulation is defined:
+
+- a) VIA-DATM manipulation concerning data entry SE appears before all the other VIA-DTAM manipulations.
+- b) All VIA-DTAM manipulations concerning REDEFINITION-ENTITY-SEs appear before all VIA-DTAM manipulations concerning BLOCK SEs.
+- c) All VIA-DTAM manipulations concerning BLOCK SEs appear before all VIA-DTAM manipulations concerning FIELD SEs.
+
+# 9 Actions of the EH and the LH
+
+## 9.1 EH action
+
+The EH provides the videotex frame to be displayed on the user's terminal by manipulating the display structure of the VIA through DTAM manipulations.
+
+NOTE – Although the action of displaying information on a videotex terminal is outside the scope of this Recommendation, it is assumed in the Recommendation that:
+
+- 1) the display of Redefinition-Entity-SEs, Block-SEs and Field-SEs is in natural order, whereby Redefinition-Entity-SEs precede Block-SEs and Field-SEs;
+- 2) only those parts of the display structure which are created or modified in a dialogue step are redisplayed in that dialogue step (i.e. deletion and recreation of Page-SE is assumed to trigger redisplay of the full screen, whereas modification of a Block-SE or Field-SE is assumed to trigger display of the new block or field content on the existing screen picture);
+
+- 3) deletion of a Block-SE or Field-SE has no effect on the screen;
+- 4) this may result in different behaviour of the local repeat functions.
+
+In addition to providing the videotex frame, the EH controls the videotex dialogue by defining a data entry program to be executed by the LH. This is provided by the manipulation of the data entry structure of the VIA through DTAM manipulations. The EH may leave the data entry structure unchanged, implying reuse of the data entry program for the next dialogue step.
+
+If a data entry program is of the “data entry type 2: data collection”, it refers to a form made up of the fields where the user enters data. If the data entry program is of the “data entry type 1: information retrieval”, it refers to an implicit field, defined by the national videotex service of the LH, where the user enters videotex commands.
+
+The data entry program contains the description of the form, and it contains the reaction, called rules to userw’s input the LH has to follow. Moreover, one or two guidance messages (prompts) may be associated with each field. This message will be displayed by the LH each time user enters the field.
+
+## 9.2 LH action
+
+### 9.2.1 Report to the EH
+
+The user input form (if any), which may consist of one or more data input fields, is reported to the EH after execution of a data entry program together with the status of the data entry program.
+
+Each field of the form respectively the implicit field used for command entry is associated with a single data entry sub-program, which is executed when data is to be entered into the field.
+
+The data entry program is terminated implicitly by the termination of the last data entry program or explicitly by some user action.
+
+The report to the EH consists of:
+
+- a) the termination status of the data entry program;
+- b) the text contents of the fields and the number of the last sub-program executed;
+- c) the text contents associated with a command.
+
+The report is performed by the manipulation of the display structure and the data entry structure, updating field text content attributes and attributes belonging to the RESULT-SE and RESULT-Content-Portion.
+
+### 9.2.2 Local actions
+
+When a data entry program is active, some local actions may be directly supported by the LH to allow for correction of mistyping, cancel of an entry and local frame repeat for instance. Such local actions as well as the local management of user errors (e.g. entry of characters not allowed in the data entry program) are treated in the LH and not reported to the EH.
+
+## 9.3 List of permissible actions on VIA structure elements in both hosts
+
+Table 1 lists up the permissible actions on VIA structure elements for both hosts. The structure elements marked by ① are automatically generated at the association establishment phase. On the other hand, the structure elements marked by ② and ③ are generated by the EH and the LH respectively and are transmitted by the DTAM manipulation services which are indicated at the top of the row on Table 1.
+
+Additionally, a default value list attribute contained in the specific SEs is only defined at the stage of SE create, and is not taken into account after the creation.
+
+TABLE 1/T.523
+
+| DTAM Manipulation VIA                       | D-CREATE | D-MODIFY | D-DELETE | D-CALL |
+|---------------------------------------------|----------|----------|----------|--------|
+| Document profile                            | Ⓘ        | ⓔ        |          |        |
+| Display                                     |          |          |          |        |
+| Document layout root                        | Ⓘ        | ⓔ        |          |        |
+| Page                                        | ⓔ        | ⓔ        | ⓔ        |        |
+| Block                                       | ⓔ        | ⓔ        | ⓔ        |        |
+| Content portion                             | ⓔ        | ⓔ        | ⓔ        |        |
+| Operational profile<br>(For further study.) |          |          |          |        |
+| Data entry                                  |          |          |          |        |
+| Data entry                                  | Ⓘ/ⓔ      | ⓔ        | ⓔ        |        |
+| Field                                       | ⓔ        | ⓔ        | ⓔ        |        |
+| Field-content portion                       | ⓔ        | ⓛ/ⓔ      | ⓔ        |        |
+| Data-entry program                          | ⓔ        | ⓔ        | ⓔ        |        |
+| Data-entry sub-program                      | ⓔ        | ⓔ        | ⓔ        |        |
+| Rules                                       | ⓔ        | ⓔ        | ⓔ        |        |
+| Prompt                                      | ⓔ        | ⓔ        |          |        |
+| Prompt-content portion                      | ⓔ        | ⓔ        |          |        |
+| Result                                      | Ⓘ        | ⓛ        |          |        |
+| Result-content portion                      | Ⓘ        | ⓛ        |          |        |
+| Application control memory                  |          |          |          |        |
+| Application control                         | Ⓘ/ⓔ      |          | ⓔ        |        |
+| Memory record                               | ⓔ        | ⓔ        | ⓔ        | ⓔ      |
+| Administrative                              |          |          |          |        |
+| Administrative information                  | Ⓘ        |          |          |        |
+| Local host information                      | Ⓘ        | ⓛ        |          |        |
+| External host information                   | Ⓘ        | ⓔ        |          |        |
+| Document information                        | Ⓘ        | ⓔ        |          |        |
+| Special terminal facilities                 |          |          |          |        |
+| Special terminal facilities                 | Ⓘ        |          |          |        |
+| Redefinition entity                         | ⓔ        | ⓔ        | ⓔ        |        |
+
+# 10 Object identifier
+
+The value of object identifier for communication application profile DM-1 defined in this Recommendation is 0 1 8 16 1.
+
+# Annex A
+
+## Abstract syntax definition of videotex specific information
+
+(This annex forms an integral part of this Recommendation)
+
+## A.1 Encoding of user information associated with D-INITIATE services
+
+The following syntax is carried by the user information of the D-INITIATE and the D-INITIATE PDUs as octet string:
+
+```
+
+ViInitInformation                ::=      SEQUENCE {
+    protocolVersion          [0]      IMPLICIT INTEGER
+                                      {viProtocolVersion1 (1)},
+    inactivityTimeOut [1]      IMPLICIT INTEGER OPTIONAL,
+    dataEntryMode            [2]      IMPLICIT INTEGER OPTIONAL
+                                      {halfDuplexDataEntryMode (1)
+                                      duplexDataEntryMode (2)
+                                      halfDuplex/duplexDataEntryMode (3)
+                                      -- the EH may not use this parameter }
+    bilateralManagement      [3]      IMPLICIT OCTET STRING OPTIONAL
+}
+
+```
+
+## A.2 Encoding of user information associated with D-ABORT services
+
+The following syntax is carried by the user information of the D-ABORT REQ PDU as octet string:
+
+```
+
+ViAbortInformation               ::=      CHOICE {
+    errorReport              [0]      IMPLICIT INTEGER
+                                      -- used for Error-Report-to-LH and Error-Report-to-EH;
+                                      -- NOTE – the total length of this PDU must not be
+                                      -- greater than 4 octets to be compatible with the
+                                      -- requirements for the ACSE ABORTpdu.
+}
+
+```
\ No newline at end of file
diff --git a/marked/T/T-REC-T.541-199303-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/T/T-REC-T.541-199303-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..d16eb76ba0390338c65f628107f6a2486a061547
--- /dev/null
+++ b/marked/T/T-REC-T.541-199303-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:7c0b073d0d2174a99959ffe7e94c664a35513f8171cbf88b27aaa9e07cd83685
+size 8315
diff --git a/marked/T/T-REC-T.561-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/T/T-REC-T.561-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..66412856f54ae0b24854202e8f031f6a04b88ee0
--- /dev/null
+++ b/marked/T/T-REC-T.561-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:a7cafe25d563af62a326eb0e9930129524893e0fb16cb431aacd25f8ed54ed31
+size 7392
diff --git a/marked/T/T-REC-T.561-198811-I_PDF-E/49ee89a1d5852ab005dbbab6de09a8a6_img.jpg b/marked/T/T-REC-T.561-198811-I_PDF-E/49ee89a1d5852ab005dbbab6de09a8a6_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..d85a847009a2064a542e30617eb2c6b154c95d1a
--- /dev/null
+++ b/marked/T/T-REC-T.561-198811-I_PDF-E/49ee89a1d5852ab005dbbab6de09a8a6_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:df8d782b05bada2ff63bab08154cab821c1f232d0428885045b748a86c72a184
+size 29292
diff --git a/marked/T/T-REC-T.561-198811-I_PDF-E/c3c305cefbac2e7b13be34ab87054d1e_img.jpg b/marked/T/T-REC-T.561-198811-I_PDF-E/c3c305cefbac2e7b13be34ab87054d1e_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..2074b247c30dd384a97efe80837d01cb743c211b
--- /dev/null
+++ b/marked/T/T-REC-T.561-198811-I_PDF-E/c3c305cefbac2e7b13be34ab87054d1e_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:b2f2f2189c271267ab13d58c1605cb7f9d7c70cfc7c2a13aa4009823d1d6ed68
+size 29504
diff --git a/marked/T/T-REC-T.561-198811-I_PDF-E/d4af765160d04ecef538e5066006dc77_img.jpg b/marked/T/T-REC-T.561-198811-I_PDF-E/d4af765160d04ecef538e5066006dc77_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..c254ff57694d949f953b64697e8a7e996f8a369f
--- /dev/null
+++ b/marked/T/T-REC-T.561-198811-I_PDF-E/d4af765160d04ecef538e5066006dc77_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:604ba36d64f2d82a492cca31c69e357932e0b4e427a3a7f121953aea87d08f81
+size 57306
diff --git a/marked/T/T-REC-T.561-198811-I_PDF-E/d864789b0d8384da1d22fd6a5d76bbdf_img.jpg b/marked/T/T-REC-T.561-198811-I_PDF-E/d864789b0d8384da1d22fd6a5d76bbdf_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..3aeac0f6d6965a9f0b313e5c97b17056a48186fa
--- /dev/null
+++ b/marked/T/T-REC-T.561-198811-I_PDF-E/d864789b0d8384da1d22fd6a5d76bbdf_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:74c80dde2b351f9fca27105fa12df71a6e17fb0816de463a28024863117f49f1
+size 29434
diff --git a/marked/T/T-REC-T.561-198811-I_PDF-E/ebff22fb5dd6f50a90e44dca0f82f285_img.jpg b/marked/T/T-REC-T.561-198811-I_PDF-E/ebff22fb5dd6f50a90e44dca0f82f285_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..1c7c233ceb30e2c70f1acbf4041d4270c26013c6
--- /dev/null
+++ b/marked/T/T-REC-T.561-198811-I_PDF-E/ebff22fb5dd6f50a90e44dca0f82f285_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:26928005cd17d5cba033d7cce6fe06da808fb3f8025bb2cab45c647ca2de435e
+size 29993
diff --git a/marked/T/T-REC-T.561-198811-I_PDF-E/fc46871d72c65d3381d9201646d23439_img.jpg b/marked/T/T-REC-T.561-198811-I_PDF-E/fc46871d72c65d3381d9201646d23439_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..482b967488bbe850b080b73433cc9ff24e6349ac
--- /dev/null
+++ b/marked/T/T-REC-T.561-198811-I_PDF-E/fc46871d72c65d3381d9201646d23439_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:fe5608a24b987d779c758a092c813db08ab6d40651dc8d0d0ef8e7f6f4d96425
+size 28669
diff --git a/marked/T/T-REC-T.561-198811-I_PDF-E/raw.md b/marked/T/T-REC-T.561-198811-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..e58032cf822a680fffe877da350a7315dfb33546
--- /dev/null
+++ b/marked/T/T-REC-T.561-198811-I_PDF-E/raw.md
@@ -0,0 +1,495 @@
+
+
+![ITU logo: a globe with the letters ITU and a lightning bolt symbol.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg)
+
+ITU logo: a globe with the letters ITU and a lightning bolt symbol.
+
+INTERNATIONAL TELECOMMUNICATION UNION
+
+**ITU-T**
+
+TELECOMMUNICATION  
+STANDARDIZATION SECTOR  
+OF ITU
+
+**T.561**
+
+**TERMINAL EQUIPMENT AND PROTOCOLS FOR  
+TELEMATIC SERVICES**
+
+---
+
+**TERMINAL CHARACTERISTICS FOR MIXED  
+MODE OF OPERATION MM**
+
+**ITU-T Recommendation T.561**
+
+(Extract from the *Blue Book*)
+
+---
+
+# NOTES
+
+1 ITU-T Recommendation T.561 was published in Fascicle VII.7 of the *Blue Book*. This file is an extract from the *Blue Book*. While the presentation and layout of the text might be slightly different from the *Blue Book* version, the contents of the file are identical to the *Blue Book* version and copyright conditions remain unchanged (see below).
+
+2 In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+# **TERMINAL CHARACTERISTICS FOR MIXED MODE OF OPERATION MM**
+
+## **CONTENTS**
+
+- 1 *Scope*
+- 2 *Field of application*
+- 3 *References*
+- 4 *Definitions*
+- 5 *General characteristics of the equipment*
+- 6 *Document handling*
+- 7 *Communication aspects*
+- 8 *Interworking between basic teletex equipments and teletex equipments supporting MM and/or PM.1*
+
+The CCITT,
+
+*considering*
+
+- (a) that telematic services have been defined or are going to be defined for a number of applications;
+- (b) that these applications, in some cases, can be conveniently combined into one single terminal to give improved performance to the users of these terminals;
+- (c) that standardization work has been aiming at common protocols and compatible parameters for various equipments and procedures;
+- (d) that teletex and Group 4 facsimile seem particularly suited to form a common service where required;
+- (e) that other services already defined or under study could be incorporated,
+
+*unanimously declares*
+
+that mixed mode characteristics should be designed and operated in accordance with the following standards.
+
+## **1 Scope**
+
+1.1 The international teletex service requirements to the mixed mode of operation MM.1 are defined in Recommendation F.230.
+
+1.2 the service requirements for Group 4 facsimile service related to the mixed mode of operation MM.1 are defined in Recommendation F.161.
+
+1.3 This Recommendation defines terminal characteristics unique to the mixed mode of operation MM.1.
+
+## 2 Field of application
+
+This Recommendation applies to terminal equipment of the teletex service or the Group 4 facsimile service supporting the mixed mode of operation MM.1.
+
+## 3 References
+
+The following CCITT Recommendations also apply to equipments for mixed mode of operations:
+
+- Rec. T.6: "Facsimile coding schemes and coding control functions for Group 4 facsimile apparatus";
+- Rec. T.60: "Terminal equipment for use in teletex service";
+- Rec. T.61: "Character repertoire and coded character sets for the international teletex service";
+- Rec. T.62: "Control procedures for the teletex and Group 4 facsimile services";
+- Rec. T.70: "Network-independent basic transport service for telematic services";
+- Rec. T.400 Series: "Document architecture transfer and manipulation";
+- Rec. T.501: "A document application profile MM for the interchange of formatted mixed mode documents";
+- Rec. T.522: "Communication application profile BT1 for document bulk transfer";
+- Rec. T.563: "Terminal characteristics for Group 4 facsimile apparatus".
+
+## 4 Definitions
+
+Terms and their definitions are defined by Recommendation listed above.
+
+## 5 General characteristics of the equipment
+
+### 5.1 General
+
+5.1.1 Equipments supporting mixed mode of operation MM.1 shall provide a set of basic features. The ability to provide this minimum set of basic features is indicated and negotiated before the document interchange.
+
+5.1.2 These equipments may in addition to the set of basic features provide other facilities. These facilities are negotiated separately from the set of basic features defined below.
+
+### 5.2 Basic features required for equipments supporting mixed mode MM.1
+
+The basic features required for equipments supporting mixed mode of operation are:
+
+5.2.1 The ability to create, transmit and receive documents conforming to the document application profile MM.1 defined in Recommendation T.501;
+
+5.2.2 The ability to interchange documents by using the application context defined in § 7.1 of this Recommendation;
+
+5.2.3 The ability to handle the ISO A4 nominal page defined in § 6.1.1.3 and to provide, at least, the assured reproduction area which is defined for ISO A4 paper size in § 6.1.1.4.
+
+5.2.4 The ability to receive and present documents, composed of:
+
+- a) one (or more) page(s) containing only content belonging to the teletex basic repertoire of Recommendation T.61;
+- b) one (or more) page(s) containing only content encoded by the raster graphics coding scheme defined in Recommendation T.6;
+- c) one (or more) page(s) containing content encoded as per a) and b);
+- d) any combination of pages defined in a), b) and c).
+
+5.2.5 For characters and raster graphics content, the ability to handle the basic features defined by Recommendation T.501.
+
+5.2.6 The ability to create blocks of different sizes which can overlap within the page.
+
+5.2.7 The ability to process up to 31 received blocks for presentation as a single page, without using negotiation.
+
+5.2.8 The ability to handle the call identification line information (see § 6.1.2).
+
+### 5.3 *Non-basic features for mixed mode*
+
+One or more additional features listed in this section may be provided by a terminal supporting mixed mode. These features have to be negotiated before the interchange of the mixed mode document.
+
+5.3.1 The ability to handle the nominal page and to provide, at least, the assured reproduction area which are defined for North American letter paper size, ISO A3 paper size, Japanese legal and Japanese letter paper sizes (see §§ 6.1.1.3 and 6.1.1.4).
+
+5.3.2 The ability to process more than 31 received blocks for presentation as a single page;
+
+5.3.3 The ability to negotiate additional presentation characteristics for particular blocks of the document for character and raster graphics content. These non-basic characteristics are specified in Recommendation T.501.
+
+## 6 **Document handling**
+
+### 6.1 *Requirements for the imaging process*
+
+#### 6.1.1 *Dimensions for text presentation*
+
+##### 6.1.1.1 *Basic measurement unit (BMU)*
+
+The size of the basic measurement unit (BMU) is 1/1200 x 25.4 mm if the output medium is paper and the locally defined scaling factor is one. To avoid introducing positioning errors between the mandatory image resolutions, it is preferred that the positioning of layout objects to specified in multiples of 20 BMU.
+
+##### 6.1.1.2 *Paper size*
+
+Different physical paper sizes can be used for presentation of mixed mode information. Such paper sizes are ISO A4 paper size (210 × 297 mm), North American letter paper size (215.9 × 279.4 mm), ISO A3 paper size (297 × 420 mm), Japanese legal paper size (257 × 364 mm) and Japanese letter paper size (182 × 257 mm).
+
+##### 6.1.1.3 *Pages and nominal pages*
+
+As defined in Recommendation T.412, a page is a rectangular area used as the reference area for positioning and imaging the content of the document. The page is intended to be positioned and imaged on a unit of the presentation surface. The ideal size of the presentation surface, as assumed by the sender of a document is the nominal page. This nominal page is equal to the ideal paper sized used (see below). In this Recommendation, the page may be equal to or smaller than the nominal page of the corresponding physical paper format.
+
+The following nominal page are defined, showing the maximum allowed dimensions of "page" layout objects:
+
+- a) nominal page for the ISO A4 paper size:
+  - width 9 920 BMU (210 mm);
+  - height 14 030 BMU (297 mm);
+- b) optional nominal page for the North American letter paper size:
+  - width 10 200 BMU (215.9 mm);
+  - height 13 200 BMU (279.4 mm);
+- c) optional nominal page for the ISO A3 paper size:
+  - width 14 030 BMU (297 mm);
+  - height 19 840 BMU (420 mm);
+- d) optional nominal page for Japanese legal paper size:
+  - width 12 141 BMU (257 mm);
+  - height 17 196 BMU (364 mm);
+- e) optional nominal page for Japanese letter paper size:
+  - width 8 598 BMU (182 mm);
+  - height 12 141 BMU (257 mm).
+
+The pages defined above describe the presentation of text information on the specified paper sizes in both the vertical and horizontal image orientations.
+
+##### 6.1.1.4 *Assured reproduction area*
+
+Hard-copy devices must allow for the possibility of edge losses cause, for example by the optional printing of a call identification line at the receiver, by tolerances on the physical paper size, and by equipment tolerances (see Annex A of Recommendation T.60). In order to cater for these edge losses, an assured reproduction area is defined which is the rectangular area that remains one the nominal page after deducting an agreed allowance for edge losses.
+
+For the option of printing a call identification line, an area at the top of the page is reserved. The same area is used for both vertical and horizontal image orientations. If used, the call identification line is to be printed on the second character baseline which is 400 BMU (8.466 mm) from the X-axis. The reserved area consists of 72 characters boxes, each 120 BMU in width and 200 BMU in height, starting at 945 BMU (20 mm) from the Y-axis and extending for 8640 BMU. The maximum permitted character baseline offset of these character boxes is 72 BMU, so that the area of assured reproduction starts at 472 BMU (10 mm) from the X-axis. Any interchanged text in the area of these character boxes may be suppressed, to avoid obscuring the image of the call identification line.
+
+The assured reproduction areas are defined as follows:
+
+###### a) ISO A4 assured reproduction area:
+
+- width = 9 240 BMU;
+- height = 13 200 BMU;
+- top margin = 472 BMU;
+- left margin = 345 BMU;
+
+###### b) North American letter assured reproduction area:
+
+- width = 9 240 BMU;
+- height = 12 400 BMU;
+- top margin = 472 BMU;
+- left margin = 345 BMU;
+
+###### c) ISO A3 assured reproduction area:
+
+- width = 13 200 BMU;
+- height = 18 480 BMU;
+- top margin = 472 BMU;
+- left margin = 345 BMU;
+
+###### d) Japanese legal assured reproduction area:
+
+- width = 11 200 BMU;
+- height = 15 300 BMU;
+- top margin = 900 BMU;
+- left margin = 400 BMU;
+
+###### e) Japanese letter assured reproduction area:
+
+- width = 7 600 BMU;
+- height = 10 200 BMU;
+- top margin = 900 BMU;
+- left margin = 400 BMU.
+
+The assured reproduction areas for ISO A4, North American letter, ISO A3, Japanese legal and Japanese letter paper sizes are illustrated in Figure 1/T.561, Figure 2/T.561, Figure 3/T.561, Figure 4/T.561 and Figure 5/T.561 respectively, showing the maximum edge losses on each paper edge. The indicated edge losses are based on the idealized or nominal paper sizes as defined in § 6.1.1.2 and do not take account of paper size tolerances.
+
+Raster graphics image parameters, for the image dimensions mentioned in Figures 1/T.561 and 2/T.561 are shown for reference in Table 1/T.561.
+
+![Diagram of nominal page and assured reproduction area for ISO A4 paper size.](fc46871d72c65d3381d9201646d23439_img.jpg)
+
+The diagram shows a rectangular page layout for ISO A4 paper size. The outer rectangle represents the 'Nominal page' with dimensions 9920 BMUs (width) and 14 030 BMUs (height). The inner rectangle represents the 'Assured reproduction area' with dimensions 9240 BMUs (width) and 13 200 BMUs (height). Marginal dimensions are indicated as follows:
+ 
+
+- Top margin: 472 BMUs
+- Bottom margin: 358 BMUs
+- Left margin: 345 BMUs
+- Right margin: 335 BMUs
+
+ The reference code 'T0803210-89' is located at the bottom right of the diagram.
+
+Diagram of nominal page and assured reproduction area for ISO A4 paper size.
+
+*Note* - These edge margin values are shown for reference only and do not take account of tolerances on either paper sizes or insertion angles.
+
+FIGURE 1/T.561
+
+Nominal page and assured reproduction area for ISO A4 paper size
+
+![Diagram of nominal page and assured reproduction area for the North American letter paper size.](49ee89a1d5852ab005dbbab6de09a8a6_img.jpg)
+
+The diagram shows a rectangular page layout for North American letter paper size. The outer rectangle represents the 'Nominal page' with dimensions 10 200 BMUs (width) and 13 200 BMUs (height). The inner rectangle represents the 'Assured reproduction area' with dimensions 9240 BMUs (width) and 12 400 BMUs (height). Marginal dimensions are indicated as follows:
+ 
+
+- Top margin: 472 BMUs
+- Bottom margin: 328 BMUs
+- Left margin: 345 BMUs
+- Right margin: 615 BMUs
+
+ The reference code 'T0803220-89' is located at the bottom right of the diagram.
+
+Diagram of nominal page and assured reproduction area for the North American letter paper size.
+
+*Note* - The indicated size and location of the assured reproduction area accommodates ISO 3535 forms UN/ECE trade documents, and the printed line lengths of the basic teletex service (i.e. 77 characters at 10 characters per 25.4 mm) for the ISO A4 paper size. For the North American letter paper size, it also accommodates ISO 3535 forms and UN/ECE trade documents, as used for that paper size.
+
+FIGURE 2/T.561
+
+Nominal page and assured reproduction area for the North American letter paper size
+
+![Diagram of ISO A3 paper size showing nominal page and assured reproduction area dimensions in BMUs.](c3c305cefbac2e7b13be34ab87054d1e_img.jpg)
+
+The diagram illustrates the dimensions of an ISO A3 paper size in BMUs (Basis Measurement Units). It shows two nested rectangles: an outer 'Nominal page' and an inner 'Assured reproduction area'. The dimensions are as follows:
+
+- Nominal page dimensions:** 14 030 BMUs (width) and 19 840 BMUs (height).
+- Assured reproduction area dimensions:** 13 200 BMUs (width) and 18 480 BMUs (height).
+- Margins (from nominal page to assured reproduction area):**
+  - Top: 472 BMUs
+  - Bottom: 888 BMUs
+  - Left: 345 BMUs
+  - Right: 485 BMUs
+
+The reference code T0803230-89 is located at the bottom right of the diagram.
+
+Diagram of ISO A3 paper size showing nominal page and assured reproduction area dimensions in BMUs.
+
+FIGURE 3/T.561
+
+Nominal page and assured reproduction area for ISO A3 paper size
+
+![Diagram of Japanese legal paper size showing nominal page and assured reproduction area dimensions in BMUs.](d864789b0d8384da1d22fd6a5d76bbdf_img.jpg)
+
+The diagram illustrates the dimensions of Japanese legal paper size in BMUs (Basis Measurement Units). It shows two nested rectangles: an outer 'Nominal page' and an inner 'Assured reproduction area'. The dimensions are as follows:
+
+- Nominal page dimensions:** 12 141 BMUs (width) and 17 196 BMUs (height).
+- Assured reproduction area dimensions:** 11 200 BMUs (width) and 15 300 BMUs (height).
+- Margins (from nominal page to assured reproduction area):**
+  - Top: 900 BMUs
+  - Bottom: 996 BMUs
+  - Left: 400 BMUs
+  - Right: 541 BMUs
+
+The reference code T0803240-89 is located at the bottom right of the diagram.
+
+Diagram of Japanese legal paper size showing nominal page and assured reproduction area dimensions in BMUs.
+
+FIGURE 4/T.561
+
+Nominal page and assured reproduction area for Japanese legal paper size
+
+![Diagram showing the nominal page and assured reproduction area for Japanese letter paper size. The diagram is a rectangle with dimensions in BMUs. The outer rectangle is 8598 BMUs wide and 12141 BMUs high. The inner rectangle is 7600 BMUs wide and 10200 BMUs high. Margins are indicated: 900 BMUs on the top, 400 BMUs on the left, 1041 BMUs on the bottom, and 598 BMUs on the right. A label 'T0803250-89' is at the bottom right. Arrows point to the 'Nominal page' (outer) and 'Assured reproduction area' (inner).](ebff22fb5dd6f50a90e44dca0f82f285_img.jpg)
+
+Diagram showing the nominal page and assured reproduction area for Japanese letter paper size. The diagram is a rectangle with dimensions in BMUs. The outer rectangle is 8598 BMUs wide and 12141 BMUs high. The inner rectangle is 7600 BMUs wide and 10200 BMUs high. Margins are indicated: 900 BMUs on the top, 400 BMUs on the left, 1041 BMUs on the bottom, and 598 BMUs on the right. A label 'T0803250-89' is at the bottom right. Arrows point to the 'Nominal page' (outer) and 'Assured reproduction area' (inner).
+
+FIGURE 5/T.561
+
+Nominal page and assured reproduction area for Japanese letter paper size
+
+TABLE 1/T.561
+
+Parameters for raster graphics images with dimensions equal to the dimensions shown in Figures 1/T.561 and 2/T.561
+
+(For reference only)
+
+| Image dimensions |       | Number of pels per line<br>at various image resolutions         |                         |                         |                         |                         |
+|------------------|-------|-----------------------------------------------------------------|-------------------------|-------------------------|-------------------------|-------------------------|
+| BMU              | mm    | 180<br>pels/<br>25.4 mm                                         | 200<br>pels/<br>25.4 mm | 240<br>pels/<br>25.4 mm | 300<br>pels/<br>25.4 mm | 400<br>pels/<br>25.4 mm |
+| 9 920            | 210.0 | 1488                                                            | 1654                    | 1984                    | 2480                    | 3308                    |
+| 9 240            | 195.6 | 1386                                                            | 1540                    | 1848                    | 2310                    | 3080                    |
+| 10 200           | 215.9 | 1530                                                            | 1700                    | 2040                    | 2550                    | 3400                    |
+|                  |       | Number of raster graphics lines at various<br>image resolutions |                         |                         |                         |                         |
+| 14 030           | 297.0 | 2104                                                            | 2339                    | 2806                    | 3508                    | 4677                    |
+| 13 200           | 279.4 | 1980                                                            | 2200                    | 2640                    | 3300                    | 4400                    |
+| 12 400           | 262.5 | 1860                                                            | 2067                    | 2480                    | 3100                    | 4133                    |
+
+##### 6.1.1.5 Positioning of the page relative to the nominal page
+
+The rules defined in Recommendation T.412, § 7.3.2 apply.
+
+#### 6.1.2 Call identification line (CIL)
+
+6.1.2.1 The basic CIL presentation rules as defined in Recommendation F.200 should apply.
+
+6.1.2.2 For printing CIL, an area, as defined in § 6.1.1.4 is provided.
+
+#### 6.1.3 *Fall-back techniques*
+
+Some basic and non-basic features described in Recommendation T.501 are allowed to be approximated using fall-back techniques.
+
+This paragraph determines the fall-back procedure which may be used by the recipient if features present in the interchanged document are not locally available.
+
+The table below identifies the features for which fall-back procedure may be used. All other features, not listed in this table, must not be approximated.
+
+| Features   | Fall-back                |
+|------------|--------------------------|
+| Bold       | Italicized or underlined |
+| Italicized | Bold or underlined       |
+
+### 6.2 *Requirements for the formatting process*
+
+Not applicable.
+
+## 7 **Communication aspects**
+
+### 7.1 *Application context for interchange of MM documents*
+
+#### 7.1.1 *Application context name*
+
+The value of the "application context name" parameter is the following object identifier value: {0 0 20 561 0}.
+
+#### 7.1.2 *Use of application service elements*
+
+##### 7.1.2.1 *Use of DTAM services*
+
+The DTAM service element (DTAMSE) is described in Recommendation T.432. For this application context, the use of DTAMSE is defined in Recommendation T.522.
+
+Specific parameter values to be used in the D-INITIATE service parameter are:
+
+- the parameter value to represent the document application profile for mixed mode MM, defined in Recommendation T.501, is the object identifier value: {0 0 20 501 0}.
+- the parameter value to represent the document application profile for processable mode PM.1, defined in Recommendation T.502, is the object identifier value: {0 0 20 502 0}.
+
+##### 7.1.2.2 *Use of association control service element (ACSE)*
+
+The ACSE is described in Recommendation X.217. For this application context, DTAMSE is the sole user of the ACSE services.
+
+*Note* - The use of reliable transfer service element (RTSE) is for further study.
+
+#### 7.1.3 *Use of presentation service*
+
+The presentation service is defined in Recommendation X.216. The ACSE is the sole user of the P-CONNECT, P-RELEASE, P-U-ABORT and P-P-ABORT services of the presentation service. For this application context, DTAMSE is the sole user of the other presentation services required for using the session functional units specified in § 7.1.4.
+
+#### 7.1.4 *Use of session service*
+
+The following session functional units are mandatory:
+
+- kernel;
+- half duplex;
+- capability data exchange;
+- minor synchronization;
+
+- exceptions;
+- activity management.
+
+*Note* - When the sender cannot know before the communication the nature of the receiver (Recommendation T.62 based or Recommendation X.200 based equipment), it is requested, for an interim period, that the "service identifier" parameter be present in the CONNECT SPDU.
+
+#### 7.1.5 *Use of transport service*
+
+The transport service is described in Recommendation X.214. The protocol shall be in accordance with Recommendation X.224, Class 0.
+
+*Note* - When the sender cannot know before the communication the nature of the receiver (Recommendation T.62 or Recommendation X.200 based equipment), it is requested, for an interim period, that additional rules in accordance with Recommendation T.70, § 5, including Annexes A and B<sup>1)</sup>, be applied in addition to Recommendations X.214/X.224.
+
+### 7.2 *Coding schemes available*
+
+7.2.1 Recommendation T.61 defines the coding scheme to be used for character coded text.
+
+7.2.2 Recommendation T.6 defines the coding techniques to be used for raster graphics.
+
+### 7.3 *Pel spacing for raster graphics content*
+
+7.3.1 Equipments must provide the capability to receive raster graphics content using pel spacings of 4 and 5 BMU which correspond respectively to pel transmission densities of 300 and 240 pels per 25.4 mm in both horizontal and vertical directions.
+
+7.3.2 Optional pel spacing may be negotiated (see § 5.3).
+
+### 7.4 *Orientation of mixed-mode page for transmission*
+
+The intended viewing orientation of mixed-mode pages may be either vertical or horizontal. For the transmission of the page the orientation shall be vertical.
+
+### 7.5 *Receiving capabilities*
+
+7.5.1 The negotiation of the storage capacity is mandatory for equipments providing mixed mode of operation.
+
+## **8 Interworking between basic teletex equipments and teletex equipments support MM and/or PM.1**
+
+### 8.1 *General*
+
+For teletex equipments supporting MM and/or PM.1:
+
+- basic teletex documents are to be interchanged according to the rules defined in Recommendation T.62 *bis*;
+- PM.1 and MM teletex documents are to be interchanged according to the application context defined in Recommendations T.561 and T.562.
+
+Figure 6/T.561 below illustrates the two different sets of rules to be used by teletex equipments depending on the interchanged document format.
+
+---
+
+<sup>1)</sup> These rules are to be specified in future Recommendation T.70 *bis*.
+
+![Diagram illustrating communication rules for teletex equipment supporting PM.1 and/or MM. The diagram shows a hierarchy of protocols: DTAMSE profile (Rec. T.522) and ACSE for PM.1/MM; Rec. X.216 and Rec. X.226 for the next level. Two cases are shown: case a) involves Rec. T.62 bis and Rec. X.215/Rec. X.225; case b) involves Rec. X.214/Rec. X.224. A note mentions Rec. T.70 bis. The diagram is labeled T0803260-89.](d4af765160d04ecef538e5066006dc77_img.jpg)
+
+The diagram illustrates the communication rules for teletex equipment supporting PM.1 and/or MM. It shows a hierarchy of protocols:
+
+- PM.1/MM** (enclosed in a dashed box):
+  - DTAMSE profile defined in Rec. T.522
+  - ACSE
+  - Rec. X.216
+  - Rec. X.226
+- Basic teletex** (enclosed in a dashed box):
+  - Rec. T.62 bis
+- Case a)**:
+  - Rec. X.215
+  - Rec. X.225
+- Case b)**:
+  - Rec. X.214
+  - Rec. X.224
+- Other references**:
+  - Rec. T.70 bis (Note) case a)
+
+The diagram is labeled T0803260-89.
+
+Diagram illustrating communication rules for teletex equipment supporting PM.1 and/or MM. The diagram shows a hierarchy of protocols: DTAMSE profile (Rec. T.522) and ACSE for PM.1/MM; Rec. X.216 and Rec. X.226 for the next level. Two cases are shown: case a) involves Rec. T.62 bis and Rec. X.215/Rec. X.225; case b) involves Rec. X.214/Rec. X.224. A note mentions Rec. T.70 bis. The diagram is labeled T0803260-89.
+
+*Note* - Recommendation T.70 bis has to be specified in the future.
+
+FIGURE 6/T.561
+
+**Illustration of the communication rules to be used  
+by teletex equipment supporting PM.1 and/or MM**
+
+### 8.2 Interworking rules
+
+#### 8.2.1 The basic teletex equipment is the sender
+
+The only type of document that can be sent by the basic teletex equipment is the basic teletex document. The sender will therefore send this type of document by using Recommendations T.62 and T.70.
+
+In order to accept the reception of the basic teletex document, the receiver has to recognize the "nature" of the originator and to select the adequate rules. For this purpose, when receiving CONNECT SPDU (which corresponds to the CSS command of Recommendation T.62), the recipient must detect the absence of session user data (SUD) and select the T.62 bis module to accept the interchanged document [case a)].
+
+#### 8.2.2 The PM.1 and/or MM teletex equipment is the sender
+
+##### 8.2.2.1 The recipient is a basic teletex equipment
+
+If the document type to be transmitted is a basic teletex document, the sender will initiate the communication by selecting case a) and the basic teletex equipment can accept the document.
+
+If the document type to be transmitted is a PM.1 and/or MM document, the sender will initiate the communication by selecting case b).
+
+The sender will then receive an ACCEPT SPDU without session user data. This allows the sender to recognize that the receiver is a basic teletex equipment and therefore that the documents are to be interchanged in a basic teletex format by using case a).
+
+The sender could then inform the user that the interchange of the P.M. 1/MM documents is not possible as the addressee is a basic teletex equipment.
+
+##### 8.2.2.2 *The recipient is a PM.1 and/or MM teletex equipment*
+
+If the document type to be transmitted is a basic teletex document, the sender will initiate the communication by selecting case a) and the rules specified in § 8.2.1 apply.
+
+If the document type to be transmitted is a PM.1 or MM teletex document, the sender will initiate the communication by selecting the case b).
+
+The recipient will detect the presence of session user data and therefore will select the T.522 module to give an adequate response to the sender.
\ No newline at end of file
diff --git a/marked/T/T-REC-T.562-198811-I_PDF-E/raw.md b/marked/T/T-REC-T.562-198811-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..a8977699ba8b21e2d420ad7a793785ad2a27af75
--- /dev/null
+++ b/marked/T/T-REC-T.562-198811-I_PDF-E/raw.md
@@ -0,0 +1,295 @@
+
+
+![ITU logo: a globe with the letters ITU and a lightning bolt symbol.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg)
+
+ITU logo: a globe with the letters ITU and a lightning bolt symbol.
+
+INTERNATIONAL TELECOMMUNICATION UNION
+
+# ITU-T
+
+TELECOMMUNICATION  
+STANDARDIZATION SECTOR  
+OF ITU
+
+## T.562
+
+**TERMINAL EQUIPMENT AND PROTOCOLS FOR  
+TELEMATIC SERVICES**
+
+---
+
+**TERMINAL CHARACTERISTICS FOR TELETEX  
+PROCESSABLE MODE PM.1**
+
+**ITU-T Recommendation T.562**
+
+(Extract from the *Blue Book*)
+
+---
+
+# NOTES
+
+1 ITU-T Recommendation T.562 was published in Fascicle VII.7 of the *Blue Book*. This file is an extract from the *Blue Book*. While the presentation and layout of the text might be slightly different from the *Blue Book* version, the contents of the file are identical to the *Blue Book* version and copyright conditions remain unchanged (see below).
+
+2 In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+# **TERMINAL CHARACTERISTICS FOR TELETEX PROCESSABLE MODE PM.1**
+
+# CONTENTS
+
+- 1 *Scope*
+- 2 *Field of application*
+- 3 *References*
+- 4 *Definitions*
+- 5 *General characteristics of the equipment*
+- 6 *Document handling*
+- 7 *Communication aspects*
+- 8 *Interworking between and basic teletex equipment and teletex equipments supporting PM.1*
+
+The CCITT,  
+*considering*
+
+(a) that telematic services have been defined or are going to be defined for a number of application;
+
+(b) that these applications, in some cases, can be conveniently combined into one single terminal to give improved performance to the users of these terminals;
+
+(c) that standardization work has been aiming at common protocols and compatible parameters for various equipments and procedures;
+
+*unanimously declares*
+
+that processable mode characteristics should be designed and operated in accordance with the following standards.
+
+## **1 Scope**
+
+1.1 The international teletex service requirements to the processable mode of operation PM.1 are defined in Recommendation F.220.
+
+1.2 This Recommendation defines terminal characteristics unique to the processable mode of operation PM. 1.
+
+## **2 Field of application**
+
+This Recommendation applies to terminal equipment of the teletex service supporting the processable mode of operation PM.1.
+
+## **3 References**
+
+The following CCITT Recommendations also apply to equipments for processable mode of operation:
+
+- Rec. T.60: "Terminal equipment for use in teletex service";
+- Rec. T.61: "Character repertoire and coded character sets for the international teletex service";
+- Rec. T.62: "Control procedures for the teletex and Group 4 facsimile services";
+- Rec. T.70: "Network-independent basic transport service for telematic services";
+- Rec. T.400 Series: "Document architecture, transfer and manipulation";
+- Rec. T.502: "A document application profile PM.1 for the interchange of processable form documents";
+- Rec. T.522: "Communication application profile BT1 for document bulk transfer".
+
+## 4 Definitions
+
+Terms and their definitions are defined by Recommendations listed above.
+
+## 5 General characteristics of the equipment
+
+### 5.1 *General*
+
+5.1.1 Equipments supporting processable mode of operation PM.1 shall provide a set of basic features. The ability to provide this minimum set of basic features is indicated and negotiated before the document interchange.
+
+5.1.2 These equipments may in addition to the set of basic features provide other facilities. These facilities are negotiated separately from the set of basic features defined below.
+
+5.1.3 Some basic and/or non-basic features are allowed to be approximated by the receiver using fall-back techniques. These features are defined in § 6.1.3.
+
+5.1.4 The negotiation is only allowed to fail when a non-basic feature is required that is not supported by the recipient and for which no suitable fall-back mode is available.
+
+## 5.2 *Basic features required for equipments supporting processable PM.1*
+
+The basic features required for equipments supporting processable mode of operation are:
+
+5.2.1 The ability to create, transmit and receive document conforming to the document application profile PM.1 defined in Recommendation T.502;
+
+5.2.2 The ability to interchange documents by using the application context defined in § 7.1 of this Recommendation;
+
+5.2.3 The ability to handle the basic nominal page defined in § 6.1.1.3 and to provide, at least, the assured reproduction area which is defined for the basic nominal page in § 6.1.1.4;
+
+5.2.4 For character content, the ability to handle the basic features defined in Recommendation T.502;
+
+5.2.5 The ability to handle the call identification line information (see § 6.1.2);
+
+5.2.6 A teletex equipment supporting PM.1 shall be able to convert PM.1 documents in formatted and/or formatted processable forms into basic teletex documents.
+
+### 5.3 *Non-basic features for processable mode*
+
+One or more additional features listed in this section may be provided by a terminal supporting PM.1.
+
+5.3.1 The ability to handle the nominal page and to provide, at least, the assured reproduction area which are defined for North American letter paper size, ISO A3 paper size (see §§ 6.1.1.3 and 6.1.1.4).
+
+5.3.2 The ability to negotiate additional presentation characteristics for characters. These non-basic characteristics are specified in Recommendation T.502.
+
+## **6 Document handling**
+
+### *6.1 Requirements for the imaging process*
+
+#### *6.1.1 Dimensions for text presentation*
+
+##### *6.1.1.1 Basic measurement unit (BMU)*
+
+The size of the basic measurement unit (BMU) is  $1/1200 \times 25.4$  mm if the output medium is paper and the locally defined scaling factor is one.
+
+##### *6.1.1.2 Paper size*
+
+Different physical paper sizes can be used for presentation of PM.1 formatted form document. Such paper sizes are ISO A4 paper size ( $210 \times 297$  mm), North American letter paper size ( $215.9 \times 279.4$  mm), ISO A3 paper size ( $297 \times 420$  mm).
+
+Character content may be imaged on those sheets of paper in horizontal as well as in vertical orientation. A single orientation must be used for all characters within one side of the sheet of paper (recto or verso).
+
+##### *6.1.1.3 Pages and nominal pages*
+
+As defined in Recommendation T.412, a page is a rectangular area used as the reference area for positioning and imaging the content of the document. The page is intended to be positioned and imaged on a unit of the presentation surface. The ideal size of the presentation surface, as assumed by the sender of a document is the nominal page.
+
+The basic page dimensions are:
+
+- width 9 240 BMU (195.6 mm);
+- height 12 400 BMU (262.5 mm).
+
+Others than the basic page dimensions are optional. These dimensions are given below:
+
+##### a) page dimensions for the ISO A4 paper size:
+
+- width 9 920 BMU (210 mm);
+- height 14 030 BMU (297 mm);
+
+##### b) page dimensions for the North American letter paper size:
+
+- width 10 200 BMU (215.9 mm);
+- height 13 200 BMU (279.4 mm);
+
+##### c) page dimensions for the ISO A3 paper size:
+
+- width 14 030 BMU (297 mm);
+- height 19 840 BMU (420 mm).
+
+##### *6.1.1.4 Assured reproduction area*
+
+Hard-copy devices must allow for the possibility of edge losses caused, for example by the optional printing of a call identification line at the receiver, by tolerances on the physical paper size, and by equipment tolerance (see Annex A of Recommendation T.60). In order to cater for these edge losses, an assured reproduction area is defined which is the rectangular area that remains on the nominal page after deducting an agreed allowance for edge losses.
+
+For the option of printing a call identification line, an area at the top of the page is reserved. The same area is used for both vertical and horizontal image orientations. If used, the call identification line is to be printed on the second character baseline which is 400 BMU (8.466 mm) from the X-axis. The reserved area consists of 72 character boxes, each 120 BMU in width and 200 BMU in height, starting at 945 BMU (20 mm) from the Y-axis and extending for 8 640 BMU. The maximum permitted character baseline offset of these character boxes is 72 BMU, so that the area of assured reproduction starts at 472 BMU (10 mm) from the X-axis. Any interchanged text in the area of these character boxes may be suppressed, to avoid obscuring the image of the call identification line.
+
+The assured reproduction areas are defined as follows:
+
+a) ISO A4 assured reproduction area:
+
+- width = 9 240 BMU;
+- height = 13 200 BMU;
+- top margin = 472 BMU;
+- left margin = 345 BMU;
+
+b) North American letter assured reproduction area:
+
+- width = 9 240 BMU;
+- height = 12 400 BMU;
+- top margin = 472 BMU;
+- left margin = 345 BMU;
+
+c) ISO A3 assured reproduction area:
+
+- width = 13 200 BMU;
+- height = 18 480 BMU;
+- top margin = 472 BMU;
+- left margin = 345 BMU.
+
+The assured reproduction areas for ISO A4, North American letter, and ISO A3 are illustrated in Figure 1/T.562, Figure 2/T.562, Figure 3/T.562, respectively, showing the maximum edge losses on each paper edge. The indicated edge losses are based on the idealized or nominal paper sizes as defined in § 6.1.1.2 and do not take account of paper size tolerances.
+
+![Diagram of nominal page and assured reproduction area for ISO A4 paper size.](fc46871d72c65d3381d9201646d23439_img.jpg)
+
+The diagram illustrates the dimensions for the nominal page and assured reproduction area for ISO A4 paper size. The nominal page is a large rectangle with a width of 9920 BMUs and a height of 14 030 BMUs. Inside this, the assured reproduction area is a smaller rectangle with a width of 9240 BMUs and a height of 13 200 BMUs. The margins between the two rectangles are specified as follows: 472 BMUs on the top, 345 BMUs on the left, 358 BMUs on the bottom, and 335 BMUs on the right. The reference code T0803270-89 is located at the bottom right of the diagram. Arrows point from the labels 'Nominal page' and 'Assured reproduction area' to their respective rectangles.
+
+Diagram of nominal page and assured reproduction area for ISO A4 paper size.
+
+*Note* -These edge margin values are shown for reference only and do not take account of tolerances on either paper sizes or insertion angles.
+
+FIGURE 1/T.562
+
+Nominal page and assured reproduction area for ISO A4 paper size
+
+![Diagram of nominal page and assured reproduction area for the North American letter paper size.](49ee89a1d5852ab005dbbab6de09a8a6_img.jpg)
+
+The diagram illustrates the dimensions for the nominal page and assured reproduction area for the North American letter paper size. The nominal page is a large rectangle with a width of 10 200 BMUs and a height of 13 200 BMUs. Inside this, the assured reproduction area is a smaller rectangle with a width of 9240 BMUs and a height of 12 400 BMUs. The margins between the two rectangles are specified as follows: 472 BMUs on the top, 345 BMUs on the left, 328 BMUs on the bottom, and 615 BMUs on the right. The reference code T0803280-89 is located at the bottom right of the diagram. Arrows point from the labels 'Nominal page' and 'Assured reproduction area' to their respective rectangles.
+
+Diagram of nominal page and assured reproduction area for the North American letter paper size.
+
+*Note* - The indicated size and location of the assured reproduction area accommodates ISO 3535 forms, UN/ECE Trade Documents, and the printed line lengths of the basic teletex service (i.e. 77 characters at 10 characters per 25.4 mm) for the ISO A4 paper size. For the North American letter paper size, it also accommodates ISO 3535 forms and UN/ECE Trade Documents, as used for that paper size.
+
+FIGURE 2/T.562
+
+Nominal page and assured reproduction area for the North American letter paper size
+
+![Diagram showing the nominal page and assured reproduction area for ISO A3 paper size. The diagram consists of two concentric rectangles. The outer rectangle represents the 'Nominal page' with dimensions 14 030 BMUs (width) and 19 840 BMUs (height). The inner rectangle represents the 'Assured reproduction area' with dimensions 13 200 BMUs (width) and 18 480 BMUs (height). Marginal dimensions are indicated: 472 BMUs (top), 345 BMUs (left), 888 BMUs (bottom), and 485 BMUs (right) for the nominal page margins. A reference code 'T0603290-89' is located at the bottom right of the diagram.](3121ebddccf183ca63bb9781be440a7e_img.jpg)
+
+Diagram showing the nominal page and assured reproduction area for ISO A3 paper size. The diagram consists of two concentric rectangles. The outer rectangle represents the 'Nominal page' with dimensions 14 030 BMUs (width) and 19 840 BMUs (height). The inner rectangle represents the 'Assured reproduction area' with dimensions 13 200 BMUs (width) and 18 480 BMUs (height). Marginal dimensions are indicated: 472 BMUs (top), 345 BMUs (left), 888 BMUs (bottom), and 485 BMUs (right) for the nominal page margins. A reference code 'T0603290-89' is located at the bottom right of the diagram.
+
+FIGURE 3/T.562
+
+###### **Nominal page and assured reproduction area for ISO A3 paper size**
+
+##### 6.1.1.5 *Positioning of the page relative to the nominal page*
+
+The rules defined in Recommendation T.412, § 7.3.2 apply.
+
+##### 6.1.1.6 *Positioning of pages on soft copy media*
+
+The rules defined in Recommendation T.412, § 7.3.5 apply.
+
+#### 6.1.2 *Call identification line (CIL)*
+
+6.1.2.1 The basic CIL presentation rules as defined in Recommendation F.200 should apply with the restriction specified in Recommendation F.220 (deletion of the page number from the CIL).
+
+6.1.2.2 For printing the CIL, an area as defined in § 6.1.1.4 is provided.
+
+#### 6.1.3 *Fall-back techniques*
+
+Some basic and non-basic features described in Recommendation T.502 are allowed to be approximated using fall-back techniques.
+
+This paragraph determines the fall-back procedure which may be used by the recipient if features present in the interchanged document are not locally available.
+
+Table 1/T.562 below identifies the features for which fall-back procedure may be used. All other features, not listed in this table, must not be approximated.
+
+TABLE 1/T.562
+
+| Features                                   | Fall-back modes          |
+|--------------------------------------------|--------------------------|
+| <i>Document layout features</i>            |                          |
+| Separation                                 | IGNORE                   |
+| Widows and orphans                         | IGNORE                   |
+| Association of paragraphs                  | IGNORE                   |
+| Recto/verso pages                          | RECTO                    |
+| <i>Content layout and imaging features</i> |                          |
+| Emphasis                                   |                          |
+| – italicized                               | Bold or underlined       |
+| – bold                                     | Italicized or underlined |
+| <i>Document management features</i>        | IGNORE                   |
+
+### 6.2 Requirements for the formatting process
+
+The formatting process shall be capable to format locally a processable PM.1 document into the formatted or the formatted-processable form before the document is sent. Additional requirements are for further study.
+
+### 6.3 Requirements for the editing process
+
+For further study.
+
+### 6.4 Requirements for the imaging process
+
+The rules for printing or displaying on screen described in Recommendation T.60 only apply to PM. 1 documents in formatted and/or formatted-processable forms. Additional requirements are for further study.
+
+## 7 Communication aspects
+
+### 7.1 Application context for interchange of PM.1 documents
+
+The application context to be used for the interchange of PM.1 documents is defined in Recommendation T.561, §7.1
+
+### 7.2 Coding schemes available
+
+7.2.1 Recommendation T.61 defines the coding scheme to be used for character content.
+
+### 7.3 Receiving capabilities
+
+7.3.1 The negotiation of the storage capacity by the DTAM protocol is mandatory for equipments providing processable mode of operation.
+
+## 8 Interworking between basic teletex equipments and teletex equipments supporting PM.1
+
+The rules defined in Recommendation T.561, § 8 apply.
\ No newline at end of file
diff --git a/marked/T/T-REC-T.563-199610-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/T/T-REC-T.563-199610-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..b73ae7b224334eb2b14f93cf7b97a5c04b08fc15
--- /dev/null
+++ b/marked/T/T-REC-T.563-199610-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:516392c22fcb61c1d767adb7daf3bc0cdef2922b2166d36e6ad5c3a5b93848c5
+size 8330
diff --git a/marked/T/T-REC-T.563-199610-I_PDF-E/36ac3e730a00d3f42d3400f5709f641a_img.jpg b/marked/T/T-REC-T.563-199610-I_PDF-E/36ac3e730a00d3f42d3400f5709f641a_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..386c8cc99a543bfffcd9c36757f8d0e810b8f288
--- /dev/null
+++ b/marked/T/T-REC-T.563-199610-I_PDF-E/36ac3e730a00d3f42d3400f5709f641a_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:dfb02bc2b38858000b25f9f1b13d88b2e35abddca45d0e7804621959db755192
+size 8700
diff --git a/marked/T/T-REC-T.563-199610-I_PDF-E/9b6b5924b48bf2fd5f347f88f06f45b3_img.jpg b/marked/T/T-REC-T.563-199610-I_PDF-E/9b6b5924b48bf2fd5f347f88f06f45b3_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..044a85a0347d99513af2f33388c0f063f0c29859
--- /dev/null
+++ b/marked/T/T-REC-T.563-199610-I_PDF-E/9b6b5924b48bf2fd5f347f88f06f45b3_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:d77bbebbd8a4041b5a5569b9bb427f26360da2f89a17f1740fc2d4decd69d4f9
+size 44171
diff --git a/marked/T/T-REC-T.563-199610-I_PDF-E/a83ba9e3e2c1e21dd69953a7b09e45b4_img.jpg b/marked/T/T-REC-T.563-199610-I_PDF-E/a83ba9e3e2c1e21dd69953a7b09e45b4_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..861fbb008c64ad7ce6df1f5b567ccc1c9896ce20
--- /dev/null
+++ b/marked/T/T-REC-T.563-199610-I_PDF-E/a83ba9e3e2c1e21dd69953a7b09e45b4_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:c51663ed95af4c2539e07d9e2fd1c15cb069638324c9b6d214ce07cfba8bc337
+size 18283
diff --git a/marked/T/T-REC-T.563-199610-I_PDF-E/fa859e4e468bfb2710a94527f2c504af_img.jpg b/marked/T/T-REC-T.563-199610-I_PDF-E/fa859e4e468bfb2710a94527f2c504af_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..2bc4fdfcece7eb4fbda87459e8b7b1e7b454b1e0
--- /dev/null
+++ b/marked/T/T-REC-T.563-199610-I_PDF-E/fa859e4e468bfb2710a94527f2c504af_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:176c2f61c2e5b0c114b1f721d3d74dd745fd7736e194ff1c1c37e821c76b9d8f
+size 21622
diff --git a/marked/T/T-REC-T.611-199411-I_PDF-E/145fb9b19dc6513e7bf84c9ba7f083f2_img.jpg b/marked/T/T-REC-T.611-199411-I_PDF-E/145fb9b19dc6513e7bf84c9ba7f083f2_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..5ae03f4cf576e69f43c1f236f06f7fa6922a8553
--- /dev/null
+++ b/marked/T/T-REC-T.611-199411-I_PDF-E/145fb9b19dc6513e7bf84c9ba7f083f2_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:ce122201163c69bc6fa9eee24e4d76283a2b1f57cb5005981056f737a5785aae
+size 51597
diff --git a/marked/T/T-REC-T.611-199411-I_PDF-E/2a66bc0c9704a184ba82b62fee0c38eb_img.jpg b/marked/T/T-REC-T.611-199411-I_PDF-E/2a66bc0c9704a184ba82b62fee0c38eb_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..9539be03dadfff0fde71b29d94cfe61850ea9608
--- /dev/null
+++ b/marked/T/T-REC-T.611-199411-I_PDF-E/2a66bc0c9704a184ba82b62fee0c38eb_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:a117a2b08564fd8b46da336dc7e9f021824355094618b8ab927c5209dcefa5d5
+size 34879
diff --git a/marked/T/T-REC-T.611-199411-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/T/T-REC-T.611-199411-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..da570fc3d3b68aff5fa5c3030e6a2a95359f9879
--- /dev/null
+++ b/marked/T/T-REC-T.611-199411-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:6f448e2b769ed40f9db061796df968febd9d49d5057233ca5650a5f2ff1a1fda
+size 8298
diff --git a/marked/T/T-REC-T.611-199411-I_PDF-E/46b6ae100e671c34c024598495e56c99_img.jpg b/marked/T/T-REC-T.611-199411-I_PDF-E/46b6ae100e671c34c024598495e56c99_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..c2c3a9092f6bb93862e0d2d75d9257fe1f757ea9
--- /dev/null
+++ b/marked/T/T-REC-T.611-199411-I_PDF-E/46b6ae100e671c34c024598495e56c99_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:6fb69d6d1a43b4f1552f77137ecc93805455e4f1b996ed6c614bd58e3705c2b8
+size 72491
diff --git a/marked/T/T-REC-T.611-199411-I_PDF-E/4801720824e4b5e2361a5564f91cfb70_img.jpg b/marked/T/T-REC-T.611-199411-I_PDF-E/4801720824e4b5e2361a5564f91cfb70_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..eadd038895dc0eb2045472f4e07e492f2a904606
--- /dev/null
+++ b/marked/T/T-REC-T.611-199411-I_PDF-E/4801720824e4b5e2361a5564f91cfb70_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:396a0dfe07b6295619a8b0142a6e8cf0b77e293762247e2e3a0208a15bdf1e14
+size 24217
diff --git a/marked/T/T-REC-T.611-199411-I_PDF-E/4b87467ad9642943235f48f7d4b59449_img.jpg b/marked/T/T-REC-T.611-199411-I_PDF-E/4b87467ad9642943235f48f7d4b59449_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..538d65b0fd7835e03c8da216be81e6850491e7f4
--- /dev/null
+++ b/marked/T/T-REC-T.611-199411-I_PDF-E/4b87467ad9642943235f48f7d4b59449_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:5485dc2abfa63344a89f24405571e79eb1f886a2c30c338692d8bb62ab034e25
+size 50334
diff --git a/marked/T/T-REC-T.611-199411-I_PDF-E/4cd9eeaee1deb05bf88a8abf02ff7d7f_img.jpg b/marked/T/T-REC-T.611-199411-I_PDF-E/4cd9eeaee1deb05bf88a8abf02ff7d7f_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..73698834b297a2441395e351f6f17e96c04af771
--- /dev/null
+++ b/marked/T/T-REC-T.611-199411-I_PDF-E/4cd9eeaee1deb05bf88a8abf02ff7d7f_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:b9bd5ae270f690953ce28d3413e781cf6d31603c39a891c27f184f86e5510964
+size 48885
diff --git a/marked/T/T-REC-T.611-199411-I_PDF-E/57939c16065211317c5442cf2a4009e0_img.jpg b/marked/T/T-REC-T.611-199411-I_PDF-E/57939c16065211317c5442cf2a4009e0_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..215acc58229984d0d04438cce86b16e6179ee9b8
--- /dev/null
+++ b/marked/T/T-REC-T.611-199411-I_PDF-E/57939c16065211317c5442cf2a4009e0_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:2701fc10924b11882514cfa5850d86d2f2d31092b98f3056bb3653b4e4dab233
+size 39372
diff --git a/marked/T/T-REC-T.611-199411-I_PDF-E/68a5a1a1a761c652b4b4c56da7cf9914_img.jpg b/marked/T/T-REC-T.611-199411-I_PDF-E/68a5a1a1a761c652b4b4c56da7cf9914_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..5f58f406d957c540a02be2f1757f051bbb10950d
--- /dev/null
+++ b/marked/T/T-REC-T.611-199411-I_PDF-E/68a5a1a1a761c652b4b4c56da7cf9914_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:d7a1f839e3c8f48de2b593b80cd7fa8ea4ea06ea73a987d2b279caf101531138
+size 52232
diff --git a/marked/T/T-REC-T.611-199411-I_PDF-E/700f2fb63fbb87c933cd81ca42fb890f_img.jpg b/marked/T/T-REC-T.611-199411-I_PDF-E/700f2fb63fbb87c933cd81ca42fb890f_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..12be466cfd9858a7cce0a4b2d9a7315b3b284279
--- /dev/null
+++ b/marked/T/T-REC-T.611-199411-I_PDF-E/700f2fb63fbb87c933cd81ca42fb890f_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:cb105a2f1130b8a577c8c24c4d44d0d5e5975a6fccb9e4d44ddd7bb6d740cf00
+size 32244
diff --git a/marked/T/T-REC-T.611-199411-I_PDF-E/7133ccf78043568ca62ecbcd43628a4a_img.jpg b/marked/T/T-REC-T.611-199411-I_PDF-E/7133ccf78043568ca62ecbcd43628a4a_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..4e54bc99242c72d2a0d49d55d882ef715e969292
--- /dev/null
+++ b/marked/T/T-REC-T.611-199411-I_PDF-E/7133ccf78043568ca62ecbcd43628a4a_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:17f6b24195bd86163b951729bae6ffc8ec27d11d9a6d91094e9c6535addc5fe7
+size 41885
diff --git a/marked/T/T-REC-T.611-199411-I_PDF-E/8a0a9aa5fac5d73eefb772afd44649f6_img.jpg b/marked/T/T-REC-T.611-199411-I_PDF-E/8a0a9aa5fac5d73eefb772afd44649f6_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..df87dfdb51122344cef207a774ef380a4702df09
--- /dev/null
+++ b/marked/T/T-REC-T.611-199411-I_PDF-E/8a0a9aa5fac5d73eefb772afd44649f6_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:ece3907b6f565f2c2621f8f7f431c22da3e040a8618ea17cf040e66d01b93389
+size 43005
diff --git a/marked/T/T-REC-T.611-199411-I_PDF-E/8fbdfc3d17fb1dae7b2d8f5a287fa9fc_img.jpg b/marked/T/T-REC-T.611-199411-I_PDF-E/8fbdfc3d17fb1dae7b2d8f5a287fa9fc_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..f86c43f423c934100f76cb7e033487d48924234c
--- /dev/null
+++ b/marked/T/T-REC-T.611-199411-I_PDF-E/8fbdfc3d17fb1dae7b2d8f5a287fa9fc_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:5d7cf8d91eba7e259076212f2e07bebff514c9426b60e84fe5149529afab991d
+size 25501
diff --git a/marked/T/T-REC-T.611-199411-I_PDF-E/90321ffa3cade82e4a57d6250d046c88_img.jpg b/marked/T/T-REC-T.611-199411-I_PDF-E/90321ffa3cade82e4a57d6250d046c88_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..5ae9d9356862009a474c82368c1b714b67ab188b
--- /dev/null
+++ b/marked/T/T-REC-T.611-199411-I_PDF-E/90321ffa3cade82e4a57d6250d046c88_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:90c57104625f8b3c96a1253ad1cc12c93f3955c5d7cbc3f719dadc270903a91d
+size 43237
diff --git a/marked/T/T-REC-T.611-199411-I_PDF-E/9ae17964ddd9b814c7d905b1af2fddf2_img.jpg b/marked/T/T-REC-T.611-199411-I_PDF-E/9ae17964ddd9b814c7d905b1af2fddf2_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..983ade6ac87bbce322ab8e6b89ba334ce9a2f193
--- /dev/null
+++ b/marked/T/T-REC-T.611-199411-I_PDF-E/9ae17964ddd9b814c7d905b1af2fddf2_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:7d3751093da86bd26a7ba7bb16042238290d0c6fe52fd9283431afd109310893
+size 17604
diff --git a/marked/T/T-REC-T.611-199411-I_PDF-E/e1a0d046fbe7f28f5e93a47091851747_img.jpg b/marked/T/T-REC-T.611-199411-I_PDF-E/e1a0d046fbe7f28f5e93a47091851747_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..7bdd1c0265afc1b93b67aea4e4f1c54cdb3f3262
--- /dev/null
+++ b/marked/T/T-REC-T.611-199411-I_PDF-E/e1a0d046fbe7f28f5e93a47091851747_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:f816cb5121536c760b50bb0cd0933687648b9b17682c8be92aaccdd7905d9a0c
+size 32008
diff --git a/marked/T/T-REC-T.611-199411-I_PDF-E/f4fdce3ce1c0fd291f31813f83d0d0d3_img.jpg b/marked/T/T-REC-T.611-199411-I_PDF-E/f4fdce3ce1c0fd291f31813f83d0d0d3_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..993e81736c8c171d922a1d9279b7e3e146810166
--- /dev/null
+++ b/marked/T/T-REC-T.611-199411-I_PDF-E/f4fdce3ce1c0fd291f31813f83d0d0d3_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:eb7dbde4ea5c6d666ea0e31a7ac4c7301e8e167b27e8b091d425c1e74c48d205
+size 54103
diff --git a/marked/T/T-REC-T.611-199411-I_PDF-E/raw.md b/marked/T/T-REC-T.611-199411-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..207065934508a3686fbda4a381236197f67f7dad
--- /dev/null
+++ b/marked/T/T-REC-T.611-199411-I_PDF-E/raw.md
@@ -0,0 +1,10291 @@
+
+
+![ITU logo: a globe with the letters ITU and a lightning bolt symbol.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg)
+
+ITU logo: a globe with the letters ITU and a lightning bolt symbol.
+
+INTERNATIONAL TELECOMMUNICATION UNION
+
+# ITU-T
+
+TELECOMMUNICATION  
+STANDARDIZATION SECTOR  
+OF ITU
+
+## T.611
+
+(11/94)
+
+# TERMINALS FOR TELEMATIC SERVICES ---
+
+**PROGRAMMING COMMUNICATION  
+INTERFACE (PCI) APPLI/COM FOR  
+FACSIMILE GROUP 3, FACSIMILE GROUP 4,  
+TELETEX, TELEX, E-MAIL AND FILE  
+TRANSFER SERVICES**
+
+**ITU-T Recommendation T.611**
+
+(Previously "CCITT Recommendation")
+
+---
+
+# FOREWORD
+
+The ITU-T (Telecommunication Standardization Sector) is a permanent organ of the International Telecommunication Union (ITU). The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis.
+
+The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics.
+
+The approval of Recommendations by the Members of the ITU-T is covered by the procedure laid down in WTSC Resolution No. 1 (Helsinki, March 1-12, 1993).
+
+ITU-T Recommendation T.611 was revised by ITU-T Study Group 8 (1993-1996) and was approved under the WTSC Resolution No. 1 procedure on the 11th of November 1994.
+
+---
+
+## NOTE
+
+In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+© ITU 1995
+
+All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU.
+
+# CONTENTS
+
+|                                                                   | <i>Page</i> |
+|-------------------------------------------------------------------|-------------|
+| PART I – GENERAL DESCRIPTION .....                                | 1           |
+| 1 Scope.....                                                      | 1           |
+| 2 Definitions and References .....                                | 1           |
+| 2.1 Interface Definitions .....                                   | 1           |
+| 2.2 File Definitions .....                                        | 2           |
+| 2.3 References.....                                               | 3           |
+| 2.4 Abbreviations and Acronyms .....                              | 4           |
+| 2.5 Operating Systems .....                                       | 6           |
+| 2.6 Trade Marks.....                                              | 6           |
+| 3 Structure of this Recommendation .....                          | 6           |
+| 3.1 Extensions to this Recommendation.....                        | 7           |
+| 4 General Principles .....                                        | 7           |
+| 4.1 Model.....                                                    | 7           |
+| 4.2 Information Exchange .....                                    | 8           |
+| 4.3 Interface Configuration Environment (ICE).....                | 10          |
+| 4.4 Submission Principle .....                                    | 11          |
+| 5 Functional Behaviour .....                                      | 11          |
+| 5.1 Functional Classes and Service Profiles .....                 | 11          |
+| 5.2 Error Handling.....                                           | 12          |
+| 5.3 Multiple LAs and multiple CAs.....                            | 13          |
+| 5.4 Identification Means .....                                    | 13          |
+| 5.5 Dispatch Received Files Facility (DRF).....                   | 15          |
+| 5.6 Communications Control – CA-Record.....                       | 15          |
+| 6 Task Data Descriptions (TDDs).....                              | 23          |
+| 6.1 Generic TDD Presentation.....                                 | 23          |
+| 6.2 Description of TDD Elements .....                             | 25          |
+| 6.3 Code-ID .....                                                 | 25          |
+| 6.4 Text Based Encoding.....                                      | 25          |
+| 6.5 Handling of Documents.....                                    | 35          |
+| 6.6 TDD Functionality.....                                        | 36          |
+| 7 Exchange Method.....                                            | 55          |
+| 7.1 Overview of Basic Exchange Method Functions.....              | 55          |
+| 7.2 Basic Exchange Method Functions.....                          | 58          |
+| 7.3 Implementation of Basic Exchange Method Functions .....       | 68          |
+| 8 Transfer Formats .....                                          | 70          |
+| 8.1 APPLI/COM Transfer Formats: Extended and Standard ASCII ..... | 72          |
+| 8.2 APPLI/COM Transfer Format: T.61 .....                         | 73          |
+| 8.3 APPLI/COM Transfer Format: TIFF.....                          | 73          |
+| 8.4 Service Constraints applying to Transfer Formats.....         | 82          |
+| 9 ICE .....                                                       | 83          |
+| 9.1 Presentation of the ICE .....                                 | 85          |
+| 9.2 Gaining access to the ICE Information.....                    | 85          |
+| 9.3 Master ICE.....                                               | 85          |
+| 9.4 CA-Descriptor.....                                            | 86          |
+| 9.5 CA-Descriptor Components .....                                | 86          |
+
+*Page*
+
+10 Functional Classes and Profiles 88
+
+10.1 Functional Class A 88
+
+10.2 Functional Class B 88
+
+10.3 Additional Functions 90
+
+10.4 Service Profiles 90
+
+PART II – SERVICE DEPENDENCIES 91
+
+11 Service: Telefax Group 3 91
+
+11.1 Service Specific Syntax Elements 91
+
+11.2 Text Based Encoding 91
+
+11.3 Additional Functionality 97
+
+11.4 CA-Descriptor Settings 100
+
+12 Service: Telefax Group 4 102
+
+12.1 Service Specific Syntax Elements 102
+
+12.2 Text Based Encoding 103
+
+12.3 Additional Functionality 107
+
+12.4 CA-Descriptor Settings 107
+
+13 Service: Teletex 107
+
+13.1 Service Specific Syntax Elements 107
+
+13.2 Text Based Encoding 112
+
+13.3 Additional Functionality 115
+
+13.4 CA-Descriptor Settings 118
+
+14 Service: Telex via Teletex 119
+
+14.1 Service Specific Syntax Elements 119
+
+14.2 Text Based Encoding 120
+
+14.3 Additional Functionality 122
+
+14.4 CA-Descriptor Settings 123
+
+15 Service: Telex 125
+
+15.1 Service Specific Syntax Elements 125
+
+15.2 Text Based Encoding 125
+
+15.3 Additional Functionality 127
+
+15.4 CA-Descriptor Settings 130
+
+16 Service: E-Mail 131
+
+16.1 Service Specific Syntax Elements 132
+
+16.2 Text Based Encoding 133
+
+16.3 Interpersonal Messaging 142
+
+16.4 Interpersonal Notification 153
+
+16.5 Delivery Report 154
+
+16.6 Mapping of MHS service elements 156
+
+16.7 E-Mail Profiles 158
+
+16.8 CA-Descriptor Settings 159
+
+17 Service: File Transfer 159
+
+17.1 Service Specific Syntax Elements 163
+
+17.2 Text Based Encoding 164
+
+17.3 Additional Functionality 167
+
+17.4 CA-Descriptor Settings 169
+
+ii **Recommendation T.611 (11/94)**
+
+|                                                                          | <i>Page</i> |
+|--------------------------------------------------------------------------|-------------|
+| PART III – BINARY ENCODING SCHEME.....                                   | 170         |
+| 18 Generic C description.....                                            | 170         |
+| 18.1 Binary encoding of TDDs.....                                        | 170         |
+| PART IV – PLATFORM DEPENDENCIES.....                                     | 194         |
+| 19 Implementation Dependencies .....                                     | 194         |
+| 19.1 Mapping of Binary Coded TDD Data Types.....                         | 194         |
+| 19.2 Default Exchange Method .....                                       | 194         |
+| 19.3 Implementation of Primitive Exchange Method.....                    | 195         |
+| Annex A – Syntax for Presentation and Encoding .....                     | 204         |
+| A.1 BNF-style Syntax.....                                                | 204         |
+| A.2 C-Language Notation.....                                             | 205         |
+| Annex B – Location of the ICE .....                                      | 205         |
+| Annex C – List of APPLI/COM Error Codes.....                             | 207         |
+| Annex D – Examples of TTD Exchanges .....                                | 209         |
+| D.1 A Sample Send Session .....                                          | 209         |
+| D.2 A Sample Receive Session .....                                       | 210         |
+| D.3 A Sample Trace Session .....                                         | 212         |
+| Annex E – Example of Interface Configuration Environment (ICE) .....     | 214         |
+| Annex F – Exchange Method of 1992 Version .....                          | 216         |
+| F.1 Exchange Method Functions of 1992 version .....                      | 216         |
+| Annex G – Service Specific Information .....                             | 222         |
+| G.1 Call Identification Line of the Telefax G4 and Teletex Service ..... | 222         |
+| G.2 Terminal ID .....                                                    | 222         |
+| Annex H – Summary of Transfer and Transmission Formats .....             | 223         |
+| H.1 Transfer Formats related to Transmission Formats .....               | 223         |
+| H.2 Transmission Formats related to Service.....                         | 223         |
+
+# **SUMMARY**
+
+This Recommendation as approved in 1992 defines a Programming Communication Interface called “APPLI/COM”, providing unified access to Telefax Group 3, Telefax Group 4, telex and teletex services.
+
+Recommendation T.611 has been revised for clarity and to include E-mail services in general, Message Handling Systems (MHS), as described in the ITU-T X.400-series of Recommendations, in particular and File Transfer Services.
+
+Special consideration has been taken to assure backwards compatibility with the 1992 version of this Recommendation.
+
+# **PROGRAMMING COMMUNICATION INTERFACE (PCI) APPLI/COM FOR FACSIMILE GROUP 3, FACSIMILE GROUP 4, TELETEx, TELEX, E-MAIL AND FILE TRANSFER SERVICES**
+
+*(revised 1994)*
+
+# **PART I – GENERAL DESCRIPTION**
+
+## **1 Scope**
+
+This Recommendation defines the Programming Communication Interface (PCI) called “APPLI/COM”.
+
+The general concepts of PCIs are defined in the ITU-T Recommendation F.581 (1992).
+
+This PCI provides unified access to different communications services, such as telefax group 3 or other telematic services.
+
+This Recommendation currently specifies the access to the following telematic services:
+
+- Telefax group 3;
+- Telefax group 4;
+- Teletex;
+- Telex<sup>1)</sup>;
+- E-Mail services;
+- File transfer services.
+
+The principle of this interface is to exchange messages between two entities (i.e. the Local Application and the Communication Application). This Recommendation describes the structure, contents of those messages and the way to exchange them. Two message encoding schemes are defined: text based and binary structured.
+
+Implementing this PCI is not required to participate in a telematic service. However, use of this interface will provide binary compatibility between the above mentioned entities. As a result end-users will benefit from plug-in compatibility between products coming from different manufacturers.
+
+This Recommendation provides a framework for future extensions that keep functionalities consistent and upward compatible.
+
+To summarize, this Recommendation forms a high level API (Application Programming Interface) which shields all telecommunication peculiarities but gives powerful control and monitoring on the telecommunication activity to the application designers.
+
+## **2 Definitions and References**
+
+### **2.1 Interface Definitions**
+
+The following definitions apply to the interface.
+
+**2.1.1 communication application (CA);** A Communication Application (CA) is provided by hardware and/or software allowing to participate in standardized telecommunications services. The telecommunications services supported by this Recommendation are listed in clause 1.
+
+---
+
+<sup>1)</sup> The access to the telex service does not include the dialogue facility.
+
+**2.1.2 local application (LA):** A Local Application (LA) is an application able to generate files or documents and possibly able to manage communications dialogues. Such LAs can be word processors, spread sheets, graphic editors, file editors, etc. The LA shall generate messages conforming to this Recommendation.
+
+**2.1.3 task data description (TDD):** A Task Data Description (TDD) describes the structure of the messages exchanged between a LA and a CA (not the way to effectively exchange them). A Request TDD describes an exchange originated by a LA towards a CA. A Response TDD describes an exchange originated by a CA towards a LA.
+
+**2.1.4 exchange method (EM):** The Exchange Method (EM) describes how the TDDs are exchanged between a CA and a LA. This Recommendation defines a generic Exchange Method which shall be adapted to the target operating system by the means described in this Recommendation. Local area and wide area network environments are supported by the generic Exchange Method.
+
+**2.1.5 CA-descriptor:** The CA-Descriptor is a collection of information concerning the use of a CA. The CA-Descriptor describes the facilities and features of a given CA so that any LA that uses that CA knows how to proceed. The CA-Descriptor is a component of the Interface Configuration Environment (ICE).
+
+**2.1.6 interface configuration environment (ICE):** The Interface Configuration Environment (ICE) is composed of the Master ICE and related CA-Descriptors. The Master ICE lists all CAs that can be reached from within a given LA. The aim of the ICE is to assist the LA in the selection of an appropriate CA with respect to the LA requirements.
+
+### 2.2 File Definitions
+
+This Recommendation deals with various kind of files: those interchanged between a LA and a CA and those exchanged through a telecommunications network. The following definitions are used throughout the body of this Recommendation.
+
+**2.2.1 transfer files:** As shown in Figure 1 the Transfer Files are those files exchanged between a LA and a CA. The format of these files (Transfer Format) is further defined in this Recommendation.
+
+![Diagram illustrating the distinct types of files defined by APPLI/COM. It shows the flow of files between a Local Application (LA), a Central Application (CA), and a Telecommunications network.](e1a0d046fbe7f28f5e93a47091851747_img.jpg)
+
+The diagram illustrates the flow of files between three main components: a Local Application (LA), a Central Application (CA), and a Telecommunications network. The flows are categorized into two main groups: Transfer files and Transmission files.
+
+- Transfer files:** These are files exchanged directly between the LA and the CA.
+  - Outgoing file:** A file sent from the LA to the CA, represented by a cylinder with an arrow pointing right.
+  - Incoming file:** A file sent from the CA to the LA, represented by a cylinder with an arrow pointing left.
+- Transmission files:** These are files exchanged between the CA and the Telecommunications network.
+  - Transmitted file:** A file sent from the CA to the network, represented by a cylinder with an arrow pointing right.
+  - Received file:** A file sent from the network to the CA, represented by a cylinder with an arrow pointing left.
+
+The diagram uses rectangles to represent the LA, CA, and Telecommunications network, and cylinders to represent the files being transferred. Arrows indicate the direction of the file flow.
+
+T0823360-95/d01
+
+Diagram illustrating the distinct types of files defined by APPLI/COM. It shows the flow of files between a Local Application (LA), a Central Application (CA), and a Telecommunications network.
+
+FIGURE 1/T.611  
+The distinct types of files defined by APPLI/COM
+
+**2.2.1.1 outgoing file:** The Outgoing File is a file that the LA transmits to the CA in order to be transmitted by the CA through a telecommunications network. The format of the file is from one of the possible Transfer Formats.
+
+**2.2.1.2 incoming file:** The Incoming File is a file transmitted to the LA by the CA. It generally corresponds to files received from the network. The format of the file is from one of the possible Transfer Formats.
+
+**2.2.1.3 transfer format:** The Transfer Format defines the structure of the Transfer Files. Depending on the telecommunication services used, some Transfer Formats are more suitable than others. The possible Transfer Formats are defined in clause 8. A Transfer Format is identified by the Convert-ID. The identification and selection of a Transfer Format is further described in 5.4.5.
+
+**2.2.2 transmission files:** The Transmission Files are files exchanged by a CA through the network. Figure **Error! Bookmark not defined.** depicts this. The format of these files, the Transmission Format, is defined intrinsically by the telecommunications service used.
+
+**2.2.2.1 transmitted file:** The Transmitted File is a file sent by the CA across a telecommunications network in a format suitable for exchange by the protocol used in the telecommunications service.
+
+**2.2.2.2 received file:** The Received File is a file built by the CA from information received through the telecommunications network in the format used for exchange by the protocol used in the telecommunications service.
+
+**2.2.2.3 transmission format:** The Transmission Format defines the structure of the Transmission Files depending on the telecommunications service used. The Transmission Format is identified by the Type-ID (see 5.4.6).
+
+### 2.3 References
+
+This Recommendation refers to the following ITU-T Recommendations:
+
+- Recommendation F.59, *General characteristics of the international telex service.*
+- Recommendation F.60, *Operational provisions for the international telex service.*
+- Recommendation F. 160, *General operational provisions for the international public facsimile services.*
+- Recommendation F. 184, *Operational provisions for international facsimile service between subscriber stations with group 4 machines (telefax group 4).*
+- Recommendation F. 200, *Teletex Service.*
+- Recommendation F. 581, *Service Recommendation for Programming Communication Interfaces.*
+- Recommendation S.1, *International telegraph alphabet No. 2.*
+- Recommendation T.4, *Standardization of group 3 facsimile apparatus for document transmission.*
+- Recommendation T.6, *Facsimile coding schemes and coding control functions for group 4 facsimile apparatus.*
+- Recommendation T.30, *Procedures for document facsimile transmission in the general switched telephone network.*
+- Recommendation T.35, *Procedure for the allocation of ITU members codes.*
+- Recommendation T.50, *International Reference Alphabet.*
+- Recommendation T.51, *Latin Alphabet coded character sets for Telematic services.*
+- Recommendation T.52, *Non-Latin coded character sets for Telematic services.*
+- Recommendation T.61, *Character repertoire and coded character sets for the international Teletex service.*
+
+NOTE – Recommendation T.61 has been superseded by Recommendation T.50-Series since 1993.
+
+- Recommendation T.62, *Control procedures for Teletex and group 4 facsimile services.*
+- Recommendation T.434, *Specification of Binary File Transfer (BFT).*
+- Recommendation T.500, *General overview of the T.500-Series of Recommendations.*
+- Recommendation T.563, *Terminal characteristics for group 4 facsimile apparatus.*
+- Recommendation T.571, *Terminal characteristics for the Telematic File Transfer within the facsimile group 4 and teletex apparatus.*
+- Recommendation X.208, *Specification of Abstract Syntax Notation one (ASN.1).*
+- Recommendation X.209, *Specification of Basic Encoding Rules for Abstract Syntax Notation one (ASN.1).*
+- Recommendation X.400, *Series of ITU-T Recommendations for Message Handling Systems.*
+
+It also refers to the following International Standards:
+
+- ISO/IEC 639.2, *Code for the presentation of code of languages.*
+- SO/IEC 9735: 1990, *Electronic Data Interchange For Administration Commerce and Transport (EDIFACT) – Application level syntax rules.*
+
+### 2.4 Abbreviations and Acronyms
+
+|           |                                                                                   |
+|-----------|-----------------------------------------------------------------------------------|
+| API       | Application Programming Interface                                                 |
+| APPLI/COM | An Interface between Local Applications and Communication Applications            |
+| ASCII     | American Standard Codes for Information Interchange                               |
+| ASN.1     | Abstract Syntax Notation one as defined per ITU-T Recommendations X.208 and X.209 |
+| BFT       | Binary File Transfer as defined per ITU-T Recommendation T.434                    |
+| BNF       | Backus Naur Form                                                                  |
+| BTM       | Basic Transparent mode as defined per ITU-T Recommendation T.434                  |
+| CA        | Communication Application                                                         |
+| CIL       | Call Identification Line                                                          |
+| CR        | Carriage return                                                                   |
+| CTL       | Control Document; document type as defined per ITU-T Recommendation T.62          |
+| DCX       | A multipage PCX file                                                              |
+| DLL       | Dynamic Link Library                                                              |
+| DRF       | Dispatch Received Files                                                           |
+| DTM       | Document Transparent mode as defined per ITU-T Recommendation T.434               |
+| E-Mail    | General used term for Electronic Mail services                                    |
+| EBCDIC    | Extended Binary Coded Data Interchange Code                                       |
+| EDI       | Electronic Data Interchange as defined per ITU-T Recommendation T.571             |
+| EM        | Exchange Method                                                                   |
+| EMail     | Service-ID for E-Mail services                                                    |
+
+|          |                                                                                                                                                                               |
+|----------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| ESC      | Escape                                                                                                                                                                        |
+| FC       | Functional Class                                                                                                                                                              |
+| FCA      | Functional Class A                                                                                                                                                            |
+| FCB      | Functional Class B                                                                                                                                                            |
+| FF       | Form Feed                                                                                                                                                                     |
+| FT       | Service-ID for File Transfer services                                                                                                                                         |
+| FX3      | Service-ID for Telefax group 3 services                                                                                                                                       |
+| FX4      | Service-ID for Telefax group 4 services                                                                                                                                       |
+| ICE      | Interface Configuration Environment                                                                                                                                           |
+| IPM      | Interpersonal Message – Message exchanged between users via UA (X.400 Terminology)                                                                                            |
+| IRA      | International Reference Alphabet (T.50)                                                                                                                                       |
+| IRV      | International Reference Version (T.50)                                                                                                                                        |
+| ISDN     | Integrated Services Digital Network                                                                                                                                           |
+| LA       | Local Application                                                                                                                                                             |
+| LAN      | Local Area Network                                                                                                                                                            |
+| LF       | Line Feed                                                                                                                                                                     |
+| MD       | Monitor Document; document type as defined per ITU-T Recommendation T.62                                                                                                      |
+| MH       | Modified Huffman code; defined per ITU-T Recommendation T.4                                                                                                                   |
+| MHS      | Message Handling System as defined per ITU-T X.400 Series of Recommendations                                                                                                  |
+| MR       | Modified Read code; defined per ITU-T Recommendation T.4                                                                                                                      |
+| MS       | Message Store (X.400 Terminology)                                                                                                                                             |
+| MTA      | Message Transfer Agent (X.400 Terminology)                                                                                                                                    |
+| MTS      | Message Transfer System (X.400 Terminology)                                                                                                                                   |
+| O/R-Name | Originator/Recipient name (X.400 Terminology)                                                                                                                                 |
+| OPD      | Operator Document; document type as defined per ITU-T Recommendation T.62                                                                                                     |
+| P1       | MTS Transfer Protocol; protocol defining the MHS envelope for MTA-MTA exchange as defined per ITU-T Recommendations X.411 (1988) and X.419 (1988, abstract syntax definition) |
+| P2       | Interpersonal Messaging Format (IPM), defined per ITU-T Recommendation X.420 (1984, or as P22 1988)                                                                           |
+| P3       | MTS Access Protocol, defined per ITU-T Recommendation X.419 (1988)                                                                                                            |
+| P7       | MS Access Protocol, defined per ITU-T Recommendation X.413 (1988)                                                                                                             |
+| PCI      | Programmable Communication Interface                                                                                                                                          |
+| PCX      | A variety of raster information file used on personal computer software                                                                                                       |
+
+|                  |                                                                                               |
+|------------------|-----------------------------------------------------------------------------------------------|
+| P <sub>edi</sub> | EDI user to user exchange format for X.400, defined per ITU-T Recommendations F.435 and X.435 |
+| PSTN             | Public Switched Telephone Network                                                             |
+| SP               | Space                                                                                         |
+| TDD              | Task Data Description                                                                         |
+| TFT              | Telematic File Transfer as defined per ITU-T Recommendation T.571                             |
+| TIFF             | Tagged Image File Format                                                                      |
+| TLX              | Service-ID for Telex services (without dialogue facility)                                     |
+| TTX              | Service-ID for Teletex services                                                               |
+| TX               | Service-ID for Telex via Teletex services                                                     |
+| UA               | User Agent (X.400 Terminology)                                                                |
+| WAN              | Wide Area Network                                                                             |
+
+### 2.5 Operating Systems
+
+The versions of the operating systems mentioned in this Recommendation are:
+
+|         |                       |
+|---------|-----------------------|
+| MacOS   | All versions          |
+| MS-DOS  | Version 3.1 or higher |
+| UNIX    | All versions          |
+| Windows | Version 3.0 or higher |
+| OS/2    | Version 1.0 or higher |
+
+Throughout this Recommendation the term DOS stands for MS-DOS compatible operating system versions.
+
+### 2.6 Trade Marks
+
+The following names are registered trade marks and belong to their respective holders:
+
+|         |                                             |
+|---------|---------------------------------------------|
+| MacOS   | Apple Computer, Inc.                        |
+| MS-DOS  | Microsoft Corporation                       |
+| UNIX    | AT&T                                        |
+| TIFF    | Aldus Corporation                           |
+| Windows | Microsoft Corporation                       |
+| OS/2    | International Business Machines Corporation |
+
+## 3 Structure of this Recommendation
+
+This Recommendation covers:
+
+- Interface requirements;
+- Definitions;
+- General principles;
+- Application features;
+- Classes of implementation;
+- Task Data Description (TDD);
+- Exchange Method;
+- Incoming and outgoing files;
+- Communications control – CA-Record.
+
+### 3.1 Extensions to this Recommendation
+
+To accommodate the evolution of telecommunication technologies, this Recommendation has been structured so as to accept new telecommunication services, or new options of existing telecommunication services without destroying the overall outline.
+
+In addition, this Recommendation provides extension mechanisms to enhance:
+
+- the exchange method between LAs and CAs;
+- the messages (TDDs);
+- the transfer formats,
+
+while preserving compatibility with the baseline Recommendation.
+
+## 4 General Principles
+
+The interface is guided by the following principles:
+
+- Be independent of computer hardware (for instance, the interface can be supported by a communications hardware or software).
+- Be independent of operating systems and programming languages (the Exchange Method is the only part that depends on operating systems and programming languages). This Recommendation provides directives to achieve compatibility on the MS-DOS, OS/2, Windows and Unix operating systems. Other operating systems will be considered on demand.
+- The formal description of interface messages is based on a BNF-like<sup>2)</sup> description. Various coding schemes may be used to present the interface messages.
+- Be task submission oriented.
+- Take into account the demand for multiple applications running on the same server as well as LAN/WAN applications. The interface can be used when several local applications and/or several communication applications are involved.
+- Be extensible and flexible.
+
+### 4.1 Model
+
+The LA-CA interaction uses the client-server model as shown in Figure 2 below.
+
+In this context:
+
+- the CA is considered as a server providing some telecommunications services to the LA;
+- the LA is considered as the client of a CA using the telecommunications services provided by this CA.
+
+Consequently:
+
+- as a server, the CA must comply with one of the two Functional Classes defined in clause 10, and with the Exchange Methods defined in this Recommendation;
+- as a client, no constraint applies on the LA, with respect to the interface.
+
+As a result, the initiation of information exchange between LA and CA always belongs to the LA. The LA may choose not to be disturbed in its local work by possible events coming from the CA.
+
+#### 4.1.1 Role of the LA
+
+Regarding the interface, the LA may be functionally separated into two parts:
+
+- the software which generates the outgoing files and/or read the incoming files;
+- the software which manages the communication.
+
+---
+
+<sup>2)</sup> BNF Backus Naur Form.
+
+![Diagram illustrating the relationship between LA and CA, and Client and Server. The LA and CA are connected via a T.611 interface. The Client and Server are connected via a Type of relationship. The diagram is labeled T0811870-93/d02.](4801720824e4b5e2361a5564f91cfb70_img.jpg)
+
+The diagram consists of two parts. On the left, a box labeled 'LA' is at the top and a box labeled 'CA' is at the bottom. A horizontal bar labeled 'T.611 interface' is positioned between them, with a double-headed vertical arrow passing through it. On the right, a box labeled 'Client' is at the top and a box labeled 'Server' is at the bottom. A double-headed vertical arrow connects them, with the text 'Type of relationship' placed next to the arrow. Below the right-hand diagram is the text 'T0811870-93/d02'.
+
+Diagram illustrating the relationship between LA and CA, and Client and Server. The LA and CA are connected via a T.611 interface. The Client and Server are connected via a Type of relationship. The diagram is labeled T0811870-93/d02.
+
+FIGURE 2/T.611
+
+**The relationship between LA and CA  
+is modelled on the client-server model**
+
+The latter provides:
+
+- 1) Man-machine dialogues or automatic processing for sending the outgoing files, handling the incoming files (display, print out, save), monitoring of CA activity, and requesting for particular system and/or service management action.
+- 2) Conversion of documents from/to a Transfer Format suitable for the CA.
+- 3) Access to optional CA features as stated in the CA-Descriptor of the ICE.
+
+NOTE – The LA, as a client, is not obliged to use all the CA features.
+
+#### 4.1.2 Role of the CA
+
+The CA, as a server, is in charge of:
+
+- the management of communications;
+- the conversion of file formats from the Transfer Format to the Transmission Format (and vice versa);
+- the management of CA features (if any) described in the CA-Descriptor of the ICE.
+
+### 4.2 Information Exchange
+
+Information to be accessed through the interface comprises:
+
+- Outgoing Files: files or documents handed by the LA to the CA in order to be transmitted by the CA on a network.
+- Incoming Files: files or documents handed by the CA to the LA after their reception by the CA from the network.
+- CA-Records: groups of information that record any transmission and reception events managed by the CA.
+
+Information exchanged between CAs and LAs are carried out by Request TDDs and Response TDDs which fall in one of the groups shown in Table 1. The table lists all TDD groups defined in this Recommendation. It specifies in particular whether a Response TDD is generated by the CA for a given Request TDD. The TDDs themselves are described in detail in clause 6.
+
+TABLE 1/T.611
+
+#### **TDD Groups**
+
+| TDD Group | Response?                   | Comment                                                                                                                                                            |
+|-----------|-----------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Send      | Yes if request requires one | Asks the CA to send one or more files through the network, using one telecommunications service, to a set of recipients                                            |
+| Receive   | Yes                         | Asks the CA to retrieve an incoming file resulting from a received file. The Response TDD is filled with the incoming file location and the transfer format        |
+| Trace     | Yes                         | Asks the CA to perform some action on one or a set of CA-Record(s) belonging to a specific state. The action to be performed is described inside the Trace request |
+| Submit    | Yes                         | Asks the CA to perform an action like converting a file to a specific format, printing out a file according to telecommunications service specific rules           |
+| Extend    | Yes                         | Provides the possibility for extensions to the Recommendation. Can be implemented as formal changes to the Recommendation, as national or as private extensions    |
+
+Proper operation of the interface requires the detailed description of a data definition and an interaction specification between the LA and the CA. Exchange Methods may coexist depending on the particular needs of different environments. Two methods of information exchange are defined (see clause 7):
+
+- one is a file exchange method which may be easily implemented over a wide range of computers and operating systems but provides lower computer throughput;
+- the other is a primitive exchange method using operating system dependent mechanisms to transport information. It provides higher throughput but reduced portability.
+
+Therefore, the concept of Task Data Description (TDD) is introduced (see Figure 3). A TDD is an abstract data structure interchanged between LA and CA, describing a particular task that the CA must carry out or describing a CA response to one of these tasks.
+
+![Diagram illustrating the Task Data Description (TDD) exchange between LA (Client) and CA (Server). The LA sends a REQUEST (containing a TDD) to the CA, and the CA returns a RESPONSE (containing a TDD) to the LA.](9ae17964ddd9b814c7d905b1af2fddf2_img.jpg)
+
+```
+
+graph LR
+    LA[LA  
+(Client)] -- REQUEST (TDD) --> CA[CA  
+(Server)]
+    CA -- RESPONSE (TDD) --> LA
+  
+```
+
+T0811880-93/d03
+
+Diagram illustrating the Task Data Description (TDD) exchange between LA (Client) and CA (Server). The LA sends a REQUEST (containing a TDD) to the CA, and the CA returns a RESPONSE (containing a TDD) to the LA.
+
+FIGURE 3/T.611  
+**Task Data Description (TDDs)**
+
+The TDDs are independent of the information exchange method used, in order to:
+
+- simplify the testing procedures;
+- leave the choice of the TDD encoding method open.
+
+A TDD carries information about the task the LA expects the CA to do, plus all the appropriate parameters. Since the communication of these tasks follows a “client-server” model, two kinds of TDDs are actually exchanged:
+
+- a Request TDD generated by the LA toward the CA, describing the action to be accomplished;
+- a Response TDD generated by the CA toward the LA, describing the response to a previous request.
+
+By construction, a LA may send many Request TDDs without waiting for the corresponding Response TDDs. Some requests are not expecting responses at all.
+
+A CA may manage Request TDDs in any order.
+
+#### 4.2.1 TDD Coding
+
+As described in more detail in 6.1, the TDDs may be encoded with different schemes, which are either text based or binary structured.
+
+#### 4.2.2 Format of Exchanged Data
+
+The format data are exchanged between LAs and CAs, namely the format of Outgoing and Incoming Files, shall conform to well defined coding and presentation rules. These rules are called Transfer Formats. The Transfer Formats are defined in detail in clause 8.
+
+### 4.3 Interface Configuration Environment (ICE)
+
+The Interface Configuration Environment (ICE) concept is used to identify the services offered by CAs within a computing environment and the characteristics of each individual CA. The ICE structure has two levels :
+
+- 1) The Master-ICE is a universally accessible file which lists all available CAs. It states how to gain access to the detailed configuration information for each CA.
+- 2) The CA-Descriptor is the source of the detailed configuration information about each CA. Access to the CA-Descriptor information may be in the form of a file or be generated via dynamic methods tailored to the computing environment such as executable files, Dynamic Link Libraries (DLLs) or other approaches.
+
+Each CA has its own unique features. The CA-Descriptor provides access to a complete list of those features. The combination of the Global ICE and CA-Descriptors provides a standardized means for LAs to access original and/or extra features of CAs. Figure **Error! Bookmark not defined.** depicts the relation between the Master ICE and the CA-Descriptors.
+
+The ICE represents a global source for all LAs conforming to this Recommendation. The Master ICE shall contain the following header information for each CA:
+
+- the Services supported by the CA;
+- the Exchange Method(s) supported by the CA;
+- one or more Access methods for each CA-Descriptor.
+
+The CA-Descriptor contains at the minimum the following set of interface related configuration information:
+
+- the Exchange Method used to interchange TDDs between LAs and the CA;
+- details of the Exchange Method (paths, buffers, entry points);
+- TDD coding;
+- functional Class;
+- supported telecommunications services;
+- CA facilities.
+
+![Diagram showing the relation between Master ICE and CA-Descriptor. A large box on the left contains 'Master ICE CA entry # 1', 'CA entry # 2', and 'CA entry # n'. Dashed arrows point from each entry to a corresponding box on the right: 'ICE # 1 CA descriptor', 'ICE # 2 CA descriptor', and 'ICE # n CA descriptor'.](8fbdfc3d17fb1dae7b2d8f5a287fa9fc_img.jpg)
+
+T0823370-95/d04
+
+Diagram showing the relation between Master ICE and CA-Descriptor. A large box on the left contains 'Master ICE CA entry # 1', 'CA entry # 2', and 'CA entry # n'. Dashed arrows point from each entry to a corresponding box on the right: 'ICE # 1 CA descriptor', 'ICE # 2 CA descriptor', and 'ICE # n CA descriptor'.
+
+FIGURE 4/T.611  
+**Relation between Master ICE and CA-Descriptor**
+
+Provision of the CA-Descriptor is mandatory for any CA. Any LA may rely on information included in the Master ICE or CA-Descriptor. LAs shall not modify information contained in the Master-ICE or a CA-Descriptor.
+
+The Master ICE is a logical file. The syntax and format of the Master-ICE and the CA-Descriptor is described in clause 9. The location of the Master ICE on a given platform is described in Annex B.
+
+### **4.4 Submission Principle**
+
+Since CAs and LAs may share differently the functions required to conform to a telecommunications service, some of these functions are possibly duplicated or missing. Examples are:
+
+- checking the conformance of a Transfer Format to specific service requirements;
+- printing a document in accordance to the telecommunications service through which it was (or will be) conveyed;
+- converting Transmission Formats to or from Transfer Formats.
+
+The submission principle allows LAs to take advantage of functions that the CA supports itself. This relieves the LA from supporting functions that are already handled by the CA. This ensures that all the required telecommunications service functions for any complying equipment are actually supported.
+
+## **5 Functional Behaviour**
+
+### **5.1 Functional Classes and Service Profiles**
+
+Two Functional Classes (FCs) are defined. These classes are called Functional Class A (FCA) and Functional Class B (FCB). Functional Class B is a superset of Functional Class A. For more detailed information refer to clause 10.
+
+The Functional Class of a CA shall be explicitly stated in the manufacturer documentation and in the appropriate field of the CA-Descriptor.
+
+Furthermore, the interface provides access to additional CA features. These features are not essential with respect to the ITU-T Recommendations. Any of these additional features may be used by a LA independent from its Functional Class, provided that the CA supports them. The additional features supported by a given CA shall be explicitly listed in the ICE (see clause 9).
+
+To further help reduce incompatibilities between different vendors' applications, this Recommendation supports the concept of Service Profiles. A Service Profile, defined for some services, groups a defined set of service features that must be supported by the implementations claiming compatibility to this Recommendation (refer to clause 10).
+
+### 5.2 Error Handling
+
+#### 5.2.1 Simple Errors
+
+Syntax elements out of context (e.g. specification of transmission speed for the telex service) shall be ignored by the CA. Execution shall continue.
+
+#### 5.2.2 Rejection
+
+All syntactical errors (i.e. unrecognized syntax elements, missing syntax elements classified as mandatory, conflicting syntax elements, multiple occurrences of a single syntax element, parameters out of range within a TDD) may lead to the rejection of the TDD. Any invalid outgoing file format may also provoke the rejection of the corresponding TDD by the CA. The CA may also discard the outgoing file. Furthermore, the CA may reject the TDD if the companion files are not transferred to the CA within a certain delay.
+
+#### 5.2.3 Error Code Ranges
+
+See Table 2.
+
+TABLE 2/T.611
+
+##### Assignment of error codes
+
+| Error code | Meaning                                                                         |
+|------------|---------------------------------------------------------------------------------|
+| 0000       | Success (no error) shall be supported by all CAs                                |
+| 0001-4999  | Reserved for CA private use                                                     |
+| 5000-5999  | Miscellaneous errors not fitting in other categories                            |
+| 6000-6999  | Syntax errors                                                                   |
+| 7000-7999  | Resource and input/output errors (operating system and hardware related errors) |
+| 8000-8999  | Conversion or Transfer Format related errors                                    |
+| 9000-9999  | Service dependent errors (service signals and failures)                         |
+
+A complete list of the error codes assigned within this Recommendation is given in Annex C.
+
+### **5.3 Multiple LAs and multiple CAs**
+
+Thanks to the interface, multiple LAs may be connected to one or several CAs simultaneously. In order to control access to multiple CAs, the ICE has been defined. On behalf of the ICE, the LA shall carry out a two-step interface set-up procedure during its initialization phase:
+
+- first, the local application shall select an appropriate communications application by inspecting the Interface Configuration Environment (ICE);
+- then, the local application shall “login” to the selected CA.
+
+Once the local application has logged into the communications application, it is free to use whatever service the CA provides, until the local application logs out from the CA.
+
+#### **5.3.1 Step 1: Selection of a CA**
+
+The first step to be carried out by the local application during the interface set-up procedure is to gain access to the ICE, which provides a list of CAs accessible from within the system (see 4.3 and clause 9).
+
+#### **5.3.2 Step 2: Login of a LA to a CA**
+
+Once the local application has selected an appropriate CA from the ICE, it has to register with the selected CA. This is called the login process. The login process is performed using an unique login-name and returns a Connection-ID. This Connection-ID is computed by the CA.
+
+To perform the login, the LA shall rely on the information found in the CA-Descriptor.
+
+The logout process allows the decoupling of the LA and the CA: it is invoked by the LA when the LA wishes to be disconnected from the CA. As a result of this logout process, the Connection-ID shall be discarded by the CA and becomes invalid. No further access on behalf of that Connection-ID shall be possible for the LA.
+
+The login and logout processes facilitate the implementation of security schemes which are especially important on multi-user systems. They also provide means to implement security mechanisms between the LA and the CA.
+
+### **5.4 Identification Means**
+
+To cope with the various interchanges of information through the interface, it is required to identify unambiguously the communicating entities and the communication events. These identifiers provide the means to:
+
+- distinguish the various telecommunications events (COM-ID);
+- identify the LAs logged in a given CA (LA-ID);
+- identify the requests generated by one LA toward a given CA (REQ-ID);
+- define the Transfer Format to be used (Convert-ID);
+- define the Transmission Format to be used (Type-ID).
+
+Following subclauses detail these identifiers.
+
+#### **5.4.1 Identification of CA Communications (COM-ID)**
+
+As long as a CA can handle different requests from different LAs and/or from the network, it is necessary to give an identification to each of those events.
+
+The COM-ID identifier is a unique identifier provided by the CA and assigned to each communications event that occurred in a CA. The COM-ID is a field of the CA-Record (see 5.6.2).
+
+A new COM-ID is generated by the CA when a CA-Record is generated. This is the case when:
+
+- 1) a LA issues a Send request to the CA;
+- 2) a LA issues a Trace request, function Reschedule to the CA;
+- 3) the CA processes a received file.
+
+The COM-ID ensures that a particular LA can retrieve any scheduled transmission request, even if the LA-CA dialogue was terminated for any reason.
+
+#### **5.4.2 Identification of LAs within a CA (LA-ID)**
+
+Since this Recommendation allows multiple LAs or multiple instances of a LA using a given CA simultaneously, LAs have to be identified uniquely to a given CA.
+
+For the purpose of distinguishing different LAs from one another, this Recommendation defines the LA-ID identifier as the unique identifier designating a particular LA instance communicating with a CA. The LA-ID is a field of the CA-Record (see 5.6.2).
+
+The CA may refuse to process any Request TDDs that contain a LA-ID not known by that CA. That provides a means to control the accesses to a CA (see 5.6.1).
+
+The LA-ID is statically assigned to the LA or to the LA instance. The rule by which the LA-ID is assigned is beyond the scope of this Recommendation.
+
+#### **5.4.3 Identification of LA requests (REQ-ID)**
+
+This Recommendation allows a LA to generate multiple requests to a CA. Since the interface allows Response TDDs to be delivered to the LA in an order different from the one the requests were given, it is necessary to identify the Request TDDs and the corresponding Response TDDs. This Recommendation thus defines the REQ-ID as the unique request reference assigned to each Request TDD and to its corresponding Response TDD.
+
+The REQ-ID is computed by the LA, by any appropriate means that guarantees uniqueness of REQ-IDs for that LA. The algorithm to use for the REQ-ID computation is beyond the scope of this Recommendation. The REQ-ID is a field of the CA-Record (see 5.6.2).
+
+Recovery procedures that could be derived from the use of the REQ-ID are beyond the scope of this Recommendation.
+
+#### **5.4.4 Reference to LA requests (REQ-REF)**
+
+The reference to a LA request (REQ-ID) is used in the Trace TDD for referencing previous Send and/or Receive TDDs.
+
+#### **5.4.5 Identification of Transfer Formats (Convert-ID)**
+
+The Transfer Format – the format used to transfer a document between LA and CA – is identified by the Convert-ID. For each service this Recommendation defines a mandatory set of different Convert-IDs, which shall be supported by the CA implementation. See also Table H.1 and related service specific sections in Part II of this Recommendation.
+
+#### **5.4.6 Identification of Transmission Formats (Type-ID)**
+
+The Transmission Format – the format used to transmit a document through the service – is identified by the Type-ID. Each service defines its set of Transmission Formats. See also related service specific sections in Part II of this Recommendation.
+
+### 5.5 Dispatch Received Files Facility (DRF)
+
+Some telecommunications services do not offer subaddressing facilities. On systems where the CA may be used by several LAs simultaneously, it is necessary to assist the routing of the incoming documents to the intended recipients. This process is called Dispatch Received Files (DRF).
+
+When a CA receives a file from the network, it shall be assigned to a single recipient LA. Then, only the recipient LA may access the received file. Selection of the recipient LA is a CA private process which is beyond the scope of this Recommendation.
+
+The CA-Record corresponding to the received file is then assigned the LA-ID of the recipient LA.
+
+If the CA supports the Dispatch Received Files facility (DRF) then the recipient LA may dispatch received files to the appropriate LA by means of the Trace:DISPATCH request (see 6.6.3). The CA-Record is then assigned the LA-ID of the LA to which the received file is dispatched.
+
+As this CA feature is optional, the support of DRF shall be declared in the CA-Descriptor (see clause 9).
+
+If the CA does not support DRF, then the CA shall assign (by any appropriate means) the CA-Record to any LA using the LA-ID field. When subaddressing is provided by the telecommunications service, the CA shall assign the CA-Record to the intended recipient LA automatically.
+
+The algorithms to use for dispatching the incoming calls to the appropriate LAs are beyond the scope of this Recommendation.
+
+### 5.6 Communications Control – CA-Record
+
+Since the exchange method between a LA and a CA is based on a client-server model, the LA always originates Request TDDs to a CA. Response TDDs from the CA are not spontaneous; the LA shall poll the CA in order to know whether any Response TDDs are available.
+
+This Recommendation provides the means for a LA to trace any communications events occurring in a CA; there is no requirement for LAs to make use of those means.
+
+A CA communications event gathers a collection of information, like date and time, originator, recipient(s), communications service, etc.
+
+The CA-Record is the functional collection of information kept by a CA in order to process a Send request or an incoming call from the network. This information is kept into fields, each of which has a special purpose.
+
+A CA-Record is generated by the CA when one of the following events occurs:
+
+- The CA receives a Send request from a LA. In this case, if the Send request contains many recipients, the CA shall expand the list of recipients and generate the same number of CA-Records as the number of recipients in the list.
+- The CA receives a Trace:RESCHEDULE request from a LA.
+- The CA receives an incoming call from the network.
+
+Optionally, a CA can generate a CA-Record in the “failed” state when the CA encounters error conditions which were not directly the consequence of a Send request or of an incoming call.
+
+CA-Records are destroyed when the LA issues Trace:PURGE requests or by CA-specific means.
+
+NOTE – A CA-Record can only be destroyed when it has reached a final state, i.e. the “retrieved”, “sent” or “failed” state (see also Figures 5 and 6).
+
+The CA-Record is an internal structure of the CA. The way to implement the CA-Record is beyond the scope of this Recommendation.
+
+#### 5.6.1 Access Control of CA-Record
+
+All actions originated by LAs on CA-Records are performed by means of the Trace request. Depending on the configuration of the CA, a CA may elect to hide some information to a LA. For example, a CA may refuse the access to “delayed” CA-Records originated by another LA.
+
+To help control accesses to a CA, this Recommendation provides a mechanism to identify LAs by means of the LA-ID. For example, all Trace requests originated by LAs incorporate the LA-ID.
+
+Thanks to this mechanism, a particular CA may elect to restrict or extend the use of some control requests to only a particular set of LAs. For example, the use of the Trace:DISPATCH request may be offered to only one LA or to a set of different LAs, depending on the system configuration; the access to the Trace:PURGE request might also be reserved to a single LA for administrative reasons.
+
+The CA manufacturer shall state in its documentation how access controls (if any) are handled and, if appropriate, how access controls may be customized to accommodate users’ configurations. Customizing CAs shall be exercised by specific means that are beyond the scope of this Recommendation.
+
+#### 5.6.2 Fields of the CA-Record
+
+The CA-Record contains a minimum list of fields which shall be supported by all CAs. CAs may support additional fields; those fields shall be declared in the ICE.
+
+Table 3 shows the minimum list of CA-Record fields that any CA shall support in the shown order:
+
+TABLE 3/T.611
+
+**Minimum list of CA-Record fields**
+
+| Field name                                                                                                                           | Syntax           | Purpose                                                                         |
+|--------------------------------------------------------------------------------------------------------------------------------------|------------------|---------------------------------------------------------------------------------|
+| COM-ID                                                                                                                               | COM-ID           | Maintain the unique communication identifier assigned to the CA-Records         |
+| LA-ID                                                                                                                                | La-id            | Assigns the CA-Record to the LA which originated it or to which it is destined  |
+| REQ-ID                                                                                                                               | Req-id           | Maintains the reference of the request                                          |
+| STATE                                                                                                                                | State            | Indicates the current state of the CA-Record                                    |
+| DIRECTION                                                                                                                            | “Xmit”/“Receive” | Indicates whether the CA-Record was generated for a transmission or a reception |
+| NOTE – Support of additional fields (e.g. charging info, time stamps, addresses) may be added by CA Manufacturers. See also 6.6.3.2. |                  |                                                                                 |
+
+The CA-Record provides a LA the ability to control the CA it is logged in. A CA-Record is at any time in one of the six following states (see Table 4).
+
+TABLE 4/T.611
+
+##### **States of CA-Record**
+
+| State name  | Concerns                | Means                                                                                                                                                                                                                                             |
+|-------------|-------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| “delayed”   | Transmission            | The associated document(s) have not yet been processed by the CA. It waits until the CA moves it in the sending state                                                                                                                             |
+| “sending”   | Transmission            | The associated document(s) have been processed by the CA for transmission; the CA has not yet finished processing it (because it is currently being sent or because the transmission had failed and the CA will carry out other attempts shortly) |
+| “sent”      | Transmission            | The associated document(s) have successfully been transmitted to the recipient                                                                                                                                                                    |
+| “failed”    | Transmission, reception | The associated document(s) failed to be transmitted, (or) errors occurred during reception (or) an internal error occurred in the CA                                                                                                              |
+| “reception” | Reception               | The record describes a document that is being received by the CA at that time, or has been received but not retrieved by the recipient LA                                                                                                         |
+| “retrieved” | Reception               | The received document has been retrieved by the recipient LA by means of the Receive request                                                                                                                                                      |
+
+Transitions from one state to another are governed by actions internal to the CA, coming from the communications network, or issued by the LA.
+
+LAs can read the state fields of a CA-Record by means of the Trace:COPY request. A particular LA may access only those records that have a matching LA-ID identifier value (unless the CA extends the access rights of some LAs). This ensures a particular LA may consult only its relevant CA-Records.
+
+The only exception to this rule is when the CA does not support DRF (see 5.5), in which case any LA can access any CA-Record which is in the reception state.
+
+The following describes the state transitions of a CA-Record in relation to the transmission and reception events occurring at the CA.
+
+#### 5.6.3 Transmission Process – State Transitions
+
+Transmissions are initiated by Send requests. When the CA receives a valid Send request from a logged-in LA, the CA builds as many CA-Records as the number of recipients contained in the Send request.
+
+Transmissions can also be originated by rescheduling transmissions that failed previously, by means of the Trace:RESCHEDULE request. In some cases this can save the delay of the conversion of the documents to suitable Transmission Formats, because those documents were already converted in a previous Send request.
+
+The CA shall assign a COM-ID to each new CA-Record. If a Send request specifies multiple recipients, the CA assigns a different COM-ID to each resulting CA-Record (one per recipient). The CA also sets the state field to the “delayed” state. The CA then copies all information from the Send request into the CA-Record.
+
+The CA scans at its own pace the list of the CA-Records in the “delayed” state and processes one of them. The choice of the “delayed” CA-Record to process first is based on scheduled dates and times that were specified in the <SendTime> field of the Send request (see Table 13, subclause 6.2). The elected CA-Record is switched to the “sending” state.
+
+The CA transmits all documents contained in the “sending” CA-Record, one by one. If transmission fails because of transmission errors, then the CA may keep the CA-Record in the “sending” state as long as it retries its transmission attempts.
+
+If the transmission eventually fails, the CA-Record is switched to the “failed” state. If the transmission eventually succeeds, the CA-Record is switched to the “sent” state. Between two attempts on the same CA-Record, the CA may pick up another CA-Record in the “delayed” state and process it as described above. Consequently, more than one CA-Record may be in the “sending” state at a given moment.
+
+Figure 5 illustrates these state transitions.
+
+![State transition diagram for the CA-Record (transmissions). The diagram shows five states: 'idle' (no CA Record), Delayed, Sending, Failed, and Sent. Transitions are triggered by actions from LA (TDD) or internal CA actions. A legend explains the symbols used.](4b87467ad9642943235f48f7d4b59449_img.jpg)
+
+```
+
+graph TD
+    Idle(["idle  
+(no CA Record)"]) -- SEND --> Delayed(["Delayed"])
+    Delayed -- "(start transmission)" --> Sending(["Sending"])
+    Delayed -- DELETE --> Failed(["Failed"])
+    Delayed -- RESCHEDULE --> Delayed
+    Sending -- "(failure)" --> Failed
+    Sending -- CANCEL --> Failed
+    Sending -- "(success)" --> Sent(["Sent"])
+    Sending -- "Network interaction" --> Sending
+    Failed --> Failed
+    
+```
+
+Legend:
+
+- State of the CA Record
+- Action from LA (TDD)
+- Internal CA action
+- ⚡ Network interaction
+
+T0823380-95/d05
+
+State transition diagram for the CA-Record (transmissions). The diagram shows five states: 'idle' (no CA Record), Delayed, Sending, Failed, and Sent. Transitions are triggered by actions from LA (TDD) or internal CA actions. A legend explains the symbols used.
+
+FIGURE 5/T.611  
+State transitions of the CA-Record (transmissions)
+
+#### 5.6.4 Reception process – State Transitions
+
+When a CA has received an incoming communication from the network, it builds a CA-Record. This CA-Record is assigned a unique COM-ID identifier and set to the “reception” state. All information concerning the incoming call (like originator, date and time, etc.) is then copied to the CA-Record in the appropriate fields.
+
+If failure has occurred during reception, the CA-Record is switched to the “failed” state. Otherwise the CA-Record is switched to the “retrieved” state, if a LA has retrieved it by means of the Receive request.
+
+The Trace:DISPATCH request has no effect on the state of the CA-Record, i.e. it remains in the “reception” state; the CA-Record is no longer visible to the “dispatching LA” and becomes visible to the recipient LA.
+
+Figure 6 illustrates these state transitions.
+
+![State transition diagram for the CA-Record (reception). The diagram shows four states: 'idle' (no CA Record), Reception, Retrieved, and Failed. Transitions are: 'idle' to Reception (success), Reception to 'idle' (failure), Reception to Retrieved (RECEIVE), Retrieved to Reception (DISPATCH), and Reception to Failed (PREVIEW). A network interaction arrow points to 'idle'. A legend defines symbols: oval for state, solid arrow for LA action, solid arrow for internal CA action, and lightning bolt for network interaction. Oval symbol Solid black arrow Solid grey arrow Lightning bolt symbol](7133ccf78043568ca62ecbcd43628a4a_img.jpg)
+
+```
+
+    graph TD
+      Idle([""idle"  
+(no CA Record)"]) 
+      Reception(["Reception"])
+      Retrieved(["Retrieved"])
+      Failed(["Failed"])
+
+      Network(( )) -- "Network interaction" ---> Idle
+      Idle -- "(success)" ---> Reception
+      Reception -- "(failure)" ---> Idle
+      Reception -- "RECEIVE" ---> Retrieved
+      Retrieved -- "DISPATCH" ---> Reception
+      Reception -- "PREVIEW" ---> Failed
+  
+```
+
+T0823390-95/d06
+
+State of the CA Record  
+ Action from LA (TDD)  
+ Internal CA action  
+ Network interaction
+
+State transition diagram for the CA-Record (reception). The diagram shows four states: 'idle' (no CA Record), Reception, Retrieved, and Failed. Transitions are: 'idle' to Reception (success), Reception to 'idle' (failure), Reception to Retrieved (RECEIVE), Retrieved to Reception (DISPATCH), and Reception to Failed (PREVIEW). A network interaction arrow points to 'idle'. A legend defines symbols: oval for state, solid arrow for LA action, solid arrow for internal CA action, and lightning bolt for network interaction. Oval symbol Solid black arrow Solid grey arrow Lightning bolt symbol
+
+FIGURE 6/T.611  
+**State transitions of the CA-Record (reception)**
+
+#### 5.6.5 Actions – Notation Conventions
+
+For the sake of legibility, the following conventions apply for the notation of the various actions involving CA-Records (see Table 5).
+
+TABLE 5/T.611  
+**Notation of actions involving the CA-Record**
+
+| Notation                                                                                                                                                    | Means                                                                                                                                                                                                                                                                                       |
+|-------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Trace:DELETE rq                                                                                                                                             | DELETE request of Trace TDD                                                                                                                                                                                                                                                                 |
+| Recipient LA                                                                                                                                                | The intended recipient of the incoming call. The recipient can be determined either automatically (example: subaddressing mechanism) or by manual dispatch. Automatic processing is a CA private matter whereas the manual dispatching can be controlled through the interface (see 10.6.1) |
+| Originating LA                                                                                                                                              | The LA that originated the CA-Record (via a Send request)                                                                                                                                                                                                                                   |
+| Transmit                                                                                                                                                    | The CA attempts to carry out the transmit action on the CA-Record                                                                                                                                                                                                                           |
+| NOTE – The CA may allow LAs of its choice to behave like a recipient or originating LA. This can be useful for many applications (example: Administration). |                                                                                                                                                                                                                                                                                             |
+
+#### 5.6.6 Actions – Transmissions
+
+This subclause describes all actions that impact the various states of the CA-Records that are involved in the transmissions.
+
+##### 5.6.6.1 Delayed State
+
+A CA-Record is in the “delayed” state as long as it has not been processed by the CA (i.e. no attempt was made to transmit it) or as long as the originating LA did not delete it. The following actions may apply to a CA-Record in the “delayed” state (see Table 6).
+
+TABLE 6/T.611
+
+###### Transmission actions for the “delayed” state
+
+| Action          | Originator     | Purpose                                                                                                                                                         | Resulting State |
+|-----------------|----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------|
+| Trace:DELETE rq | Originating LA | To delete a Send request. This action operates on only one CA-Record at a time                                                                                  | “failed”        |
+| Trace:COPY rq   | Originating LA | To build a logical file containing a copy of the list of the “delayed” CA-Records. This action applies to all “delayed” CA-Records originating from a single LA | “delayed”       |
+| Transmit        | CA             | The CA decides to handle the CA-Record, because it has become due to process                                                                                    | “sending”       |
+
+##### 5.6.6.2 Sending State
+
+A CA-Record is in the “sending” state when the CA attempts to transmit the information contained in it.
+
+If the attempt fails, the CA-Record may remain in the “sending” state waiting for the next attempt; the CA shall delay the next attempt with respects to the “retry delay” unless the “maximum number of attempts” is reached, in which case the CA-Record is set to the “failed” status.
+
+The following actions may apply to a CA-Record in the “sending” state (see Table 7).
+
+TABLE 7/T.611
+
+###### Transmission actions for the “sending” state
+
+| Action          | Originator     | Purpose                                                                           | Resulting State |
+|-----------------|----------------|-----------------------------------------------------------------------------------|-----------------|
+| Trace:CANCEL rq | Originating LA | To cancel a Send request. This affects only one CA-Record at a time               | “failed”        |
+| Trace:COPY rq   | Originating LA | To build a logical file containing a copy of the list of the “sending” CA-Records | “sending”       |
+
+##### 5.6.6.3 Sent State
+
+A CA-Record is in the “sent” state when the CA succeeded in transmitting the information contained in it.
+
+The following actions may apply to a CA-Record in the “sent” state (see Table 8).
+
+TABLE 8/T.611
+
+###### **Transmission actions for the “sent” state**
+
+| Action         | Originator     | Purpose                                                                        | Resulting state                         |
+|----------------|----------------|--------------------------------------------------------------------------------|-----------------------------------------|
+| Trace:PURGE rq | Originating LA | To remove all the CA-Records being in the “sent” state                         | Not applicable because removed (purged) |
+| Trace:COPY rq  | Originating LA | To build a logical file containing a copy of the list of the “sent” CA-Records | “sent”                                  |
+
+##### **5.6.6.4 Failed State**
+
+A CA-Record is in the “failed” state when the CA failed to transmit the information contained in it for any reason.
+
+NOTE – The failed state also applies for the reception process. See below for relevant information.
+
+The following actions may apply to a CA-Record in the “failed” state (see Table 9).
+
+TABLE 9/T.611
+
+###### **Transmission actions for the “failed” state**
+
+| Action              | Originator     | Purpose                                                                                               | Resulting State                         |
+|---------------------|----------------|-------------------------------------------------------------------------------------------------------|-----------------------------------------|
+| Trace:PURGE rq      | Originating LA | To remove CA-Records being in the “failed” state                                                      | Not applicable because removed (purged) |
+| Trace:RESCHEDULE rq | Originating LA | To ask for reprocessing of a failed request. This can take advantage of previous document conversions | “delayed”                               |
+| Trace:COPY rq       | Originating LA | To build a logical file containing a copy of the list of the “failed” CA-Records                      | “failed”                                |
+
+#### **5.6.7 Actions – Receptions**
+
+This subclause describes all actions that impact the states of the CA-Records that relate to reception.
+
+##### **5.6.7.1 Reception State**
+
+A CA-Record is in the “reception” state when the CA successfully received an incoming call from the network, and the CA-Record has not been dispatched already.
+
+The following actions may apply to a CA-Record in the “reception” state (see Table 10).
+
+TABLE 10/T.611
+
+###### **Reception actions for the “reception” state**
+
+| Action                                                                            | Originator            | Purpose                                                                                                                                                                                                                 | Resulting State |
+|-----------------------------------------------------------------------------------|-----------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------|
+| RECEIVE rq                                                                        | Recipient LA          | To retrieve the document(s) relevant to the CA-Record (as well as related information in the Response-TDD)                                                                                                              | “retrieved”     |
+| Trace:PREVIEW rq                                                                  | any LA                | To receive a copy of the document(s) relevant to the CA-Record. The CA-Record remains in the “reception” state                                                                                                          | “reception”     |
+| Trace:DISPATCH rq                                                                 | Recipient LA or Admin | To assign one or more LA-ID(s) to a received CA-Record (see also Note below)                                                                                                                                            | “reception”     |
+| Trace:COPY rq                                                                     | Recipient LA          | To build a logical file containing a copy of the list of the CA-Records in “reception” state, thus not having been retrieved already. A recipient LA “sees” only its relevant CA-Records, i.e. those matching the LA-ID | “reception”     |
+| NOTE – The Management of the Admin (Administrator) is a private matter of the CA. |                       |                                                                                                                                                                                                                         |                 |
+
+##### **5.6.7.2 Retrieved State**
+
+A CA-Record is in the “retrieved” state when the CA-Record has been retrieved by a LA with a matching LA-ID by means of the Receive request.
+
+The following actions may apply to a CA-Record in the “retrieved” state (see Table 11).
+
+TABLE 11/T.611
+
+###### **Reception actions for the “retrieved” state**
+
+| Action         | Originator   | Purpose                                                                                                                                                                         | Resulting State                         |
+|----------------|--------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------|
+| Trace:PURGE rq | Recipient LA | To remove CA-Records which are in the “retrieved” state                                                                                                                         | Not applicable because removed (purged) |
+| Trace:COPY rq  | Recipient LA | To build a logical file containing a copy of the list of the CA-Records in “retrieved” state. A recipient LA “sees” only its relevant CA-Records, i.e. those matching the LA-ID | “retrieved”                             |
+
+##### **5.6.7.3 Failed State**
+
+A CA-Record is in the “failed” state when the CA failed to receive an incoming call from the network for any reason.
+
+NOTE – The failed state also applies for the transmission process. See 5.6.6.4 for relevant information.
+
+When a CA fails to receive an incoming call, the CA switches the CA-Record from the “reception” state to the “failed” state.
+
+When a CA-Record is in the “failed” state, no LA-ID is assigned to it. Depending on the configuration, the CA may (but is not obliged to) assign a LA-ID on those “failed” records by any appropriate means. The Trace:RESCHEDULE request does not apply on received “failed” CA-Records.
+
+Table 12 details the actions that may apply on the CA-Records in the “failed” state.
+
+TABLE 12/T.611
+
+###### **Reception actions for the “failed” state**
+
+| Action         | Originator   | Purpose                                                                                                                                       | Resulting State                         |
+|----------------|--------------|-----------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------|
+| Trace:PURGE rq | Recipient LA | To remove all the CA-Records being in the “failed” state                                                                                      | Not applicable because removed (purged) |
+| Trace:COPY rq  | Recipient LA | To build a logical file containing a copy of the list of the CA-Records in “failed” state. A recipient LA “sees” all CA-Records in this state | “failed”                                |
+
+## 6 Task Data Descriptions (TDDs)
+
+The functionality offered by the CA through the interface is invoked by TDDs, which are passed as requests from the LA to the CA and – depending on the function invoked – passed vice versa as response.
+
+This clause describes the semantic, functionality, syntax and encoding of the various Request TDDs and responses.
+
+### 6.1 Generic TDD Presentation
+
+The TDDs can be encoded with different schemes. Some of these coding schemes are based on text descriptions, i.e. ASCII or EBCDIC. Other coding schemes cannot be represented by text. Examples of such coding schemes include the binary encoding scheme, which is presented in C-language notation in Part III of this Recommendation.
+
+The various TDDs are hereafter described generically with a BNF-style syntax. The details of this syntax are explained in A.1.
+
+As an aid to understanding, together with the generic BNF-style syntax given below the text based encoding is used in the subclauses to follow. However, the binary encoding scheme (defined in Part III of this Recommendation) may alternatively be used for implementations.
+
+<TDD> :=                               <TDD Header>  
+                                            <Send> | <Receive> | <Trace> | <Submit> | <Extend>
+
+<TDD Header> :=                   -- dependent of encoding used. For text based encoding see 6.4.3,  
+                                            -- for binary encoding scheme see appropriate clause in Part III  
+                                            -- of this Recommendation
+
+<Send> :=                               <SendTDD> | <SendAckTDD>
+
+<Receive> :=                           <ReceiveTDD>
+
+<Trace> :=                             <DeleteTDD> | <CopyTDD> | <CancelTDD> | <PurgeTDD> |  
+                                            <RescheduleTDD> | <DispatchTDD> | <PreviewTDD>
+
+
+
+<ExtendTDD> :=                   <ExtendFunction> <SubFunction> <LaId> <ReqId> <Error> [<Minor>]  
+                                     [Warning] [<ExtendSubFunctionKeywords>]
+
+<ExtendSubFunctionKeywords> :=  
+                                     *-- defined in appropriate clause of Part II for each service*
+
+<NationalTDD> :=                 <NationalFunction> <SubFunction> <LaId> <ReqId> <Error> [<Minor>]  
+                                     [Warning] [<NationalSubFunctionKeywords>]
+
+<NationalSubFunctionKeywords> :=  
+                                     *-- for further study*
+
+<PrivateTDD> :=                  <PrivateFunction> <SubFunction> <LaId> <ReqId> <Error> [<Minor>]  
+                                     [Warning] [<PrivateSubFunctionKeywords>]
+
+<PrivateSubFunctionKeywords> :=  
+                                     *-- for further study*
+
+### 6.2 Description of TDD Elements
+
+In general, there are two types of syntax elements within a TDD:
+
+- 1) those which parameters are only dependent on the functionality of the TDD;
+- 2) those which parameters are dependent on the service the TDD is applied to.
+
+In case the TDD is dealing with sending or receiving files or documents, the parameters of some syntax elements may also be specific to
+
+- the addressee (e.g. the attribute primary or copy recipient for E-Mail services);
+- the document itself (e.g. Transfer and Transmission Format).
+
+In Table 13 the *non* service dependent syntax elements of the TDDs are explained. The service, addressee or document specific syntax elements of the TDDs are described in the appropriate clauses of Part II of this Recommendation.
+
+### 6.3 Code-ID
+
+The very first octet of every TDD, independent of its encoding, indicates the coding scheme. This octet is called the Code-ID. Table 14 lists the possible Code-IDs assigned by this Recommendation.
+
+### 6.4 Text Based Encoding
+
+This subclause refers to encodings with the Code-ID set to "A", "B", "I" or "E".
+
+For description of the text based encoding, the BNF-style syntax explained in A.1 is used in the following subclauses.
+
+#### 6.4.1 Syntax and Formatting
+
+The syntax elements listed in 6.1 are encoded using keyword/parameter pairs. The mapping of the keyword/parameter pairs to the syntax elements is shown in Table 15 below. Since some syntax elements and the corresponding functionality depends on the underlying telecommunications service, only those being invariant to the telecommunications service are presented. The syntax elements depending on a telecommunications service are described in the appropriate clause of Part II of this Recommendation.
+
+TABLE 13/T.611
+
+##### **Summary of non service dependent TDD syntax elements**
+
+| Syntax Element                 | Purpose                                                                                                                                                                                                 |
+|--------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| <CancelFunction>               | Identifies the function requested by the TDD                                                                                                                                                            |
+| <Check>                        | Gives the format a given File shall be checked against. Used only in the <CheckTDD>                                                                                                                     |
+| <CheckFunction>                | Identifies the function requested by the TDD                                                                                                                                                            |
+| <ComId>                        | ComId stands for COMMunication-ID. See 5.4.1                                                                                                                                                            |
+| <Comment>                      | Used to attach a free comment to a document, which shall be transmitted. This comment then is stored in the CA-Record, rather than transmitted with the document through the telecommunications service |
+| <ConvertFunction>              | Identifies the function requested by the TDD                                                                                                                                                            |
+| <CopyFunction>                 | Identifies the function requested by the TDD                                                                                                                                                            |
+| <Delete>                       | Tells the CA whether a document received shall be deleted from the internal storage of the CA after successful retrieval carried out by the calling LA                                                  |
+| <DeleteFunction>               | Identifies the function requested by the TDD                                                                                                                                                            |
+| <Direction>                    | Specifies whether the CA-Record belongs to an incoming or an outgoing document                                                                                                                          |
+| <Dispatched>                   | Specifies if the <DispatchTDD> has been applied to the specific CA-Record                                                                                                                               |
+| <DispatchFunction>             | Identifies the function requested by the TDD                                                                                                                                                            |
+| <Error>                        | This syntax element returns the error code generated by the CA in the Response-TDD. It shall be checked by the LA for successful operation                                                              |
+| <ExtendFunction>               | Identifies the function requested by the TDD                                                                                                                                                            |
+| <ExtendSubFunction-Keywords>   | See appropriate clause of Part II of this Recommendation                                                                                                                                                |
+| <FileName>                     | Contains the path to the file the document is stored in                                                                                                                                                 |
+| <InFormat>                     | Specifies the input format of a document. Only used in the <Convert-TDD>                                                                                                                                |
+| <LaId>                         | LaId stands for LA-ID. See 5.4.2                                                                                                                                                                        |
+| <LastTime>                     | Gives the latest time a CA shall try to send the document specified in the related TDD                                                                                                                  |
+| <Layout>                       | Defines the layout of the target file of the <CopyTDD>                                                                                                                                                  |
+| <Minor>                        | This syntax element returns an additional error code in the Response-TDD                                                                                                                                |
+| <NationalFunction>             | Identifies the function requested by the TDD                                                                                                                                                            |
+| <NationalSubFunction-Keywords> | For further study                                                                                                                                                                                       |
+| <NewLa>                        | Contains the new LA-ID for use with the <DispatchTDD>                                                                                                                                                   |
+| <OutFormat>                    | Specifies the output format of a document. Only used in the <Convert-TDD>                                                                                                                               |
+| <Previewed>                    | Specifies if the <PreviewTDD> has been applied to the specific CA-Record                                                                                                                                |
+
+TABLE 13/T.611 (*end*)
+
+##### **Summary of non service dependent TDD syntax elements**
+
+| Syntax Element                     | Purpose                                                                                                                                                                          |
+|------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| <Printer>                          | ID of selected printer for use with the <PrintTDD>. Depends on the supporting operating system. The CA manufacturer shall state in his documentation how to address the printers |
+| <PrintFunction>                    | Identifies the function requested by the TDD                                                                                                                                     |
+| <PrivateFunction>                  | Identifies the function requested by the TDD                                                                                                                                     |
+| <PrivateSubFunction-Keywords>      | For further study                                                                                                                                                                |
+| <PurgeFunction>                    | Identifies the function requested by the TDD                                                                                                                                     |
+| <ReceiveFunction>                  | Identifies the function requested by the TDD                                                                                                                                     |
+| <ReqId>                            | ReqId stands for REQ-ID. See 5.4.3                                                                                                                                               |
+| <ReceiveTime>                      | Gives the time the CA received the document specified in the related TDD                                                                                                         |
+| <ReqRef>                           | ReqId stands for REQ-REF. See 5.4.4                                                                                                                                              |
+| <RescheduleFunction>               | Identifies the function requested by the TDD                                                                                                                                     |
+| <SendackFunction>                  | Identifies the function requested by the TDD                                                                                                                                     |
+| <SendFunction>                     | Identifies the function requested by the TDD                                                                                                                                     |
+| <SendTime>                         | Gives the time the CA shall send the document specified in the related TDD                                                                                                       |
+| <Service>                          | Specifies the telecommunications service used. See also Part II of this Recommendation                                                                                           |
+| <ServiceDependent-KeywordsReceive> | See appropriate clause of Part II of this Recommendation                                                                                                                         |
+| <ServiceDependent-KeywordsSend>    | See appropriate clause of Part II of this Recommendation                                                                                                                         |
+| <ServiceDependent-KeywordsSendack> | See appropriate clause of Part II of this Recommendation                                                                                                                         |
+| <State>                            | Specifies the state of a CA-Record. See also Table 4 in 5.6.2                                                                                                                    |
+| <Status>                           | Returns the status of a transmission or reception in the Response-TDD                                                                                                            |
+| <SubFunction>                      | Identifies the function requested by the TDD                                                                                                                                     |
+| <Target>                           | Used in the <ConvertTDD> and in the <CopyTDD> to specify the path to the output file generated by the CA                                                                         |
+| <TimeRange>                        | Specifies a time range for selecting specific CA-Records                                                                                                                         |
+| <UserKey>                          | Contains a key attached to the Request-TDD of the <SendTDD> and the <SendAckTDD>                                                                                                 |
+| <Warning>                          | This syntax element returns an additional warning code in the Response-TDD                                                                                                       |
+
+TABLE 14/T.611
+
+##### **TDD Encoding – Code-IDs**
+
+| Code-ID                                                                                                                                                                                                                                                                                                 |                   | TDD Representation                                                                                                                                                                        |
+|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Value                                                                                                                                                                                                                                                                                                   | Text Presentation |                                                                                                                                                                                           |
+| 41 <sub>hex</sub>                                                                                                                                                                                                                                                                                       | "A"               | Readable text, organized as lines of keyword/parameter pairs. The character set utilized shall correspond to the APPLI/COM Extended ASCII character set (see Table 50)                    |
+| 42 <sub>hex</sub>                                                                                                                                                                                                                                                                                       | "B"               | Readable text, organized as lines of keyword/parameter pairs. The character set used shall correspond to a national variant of the character set as defined per ITU-T Recommendation T.50 |
+| 43 <sub>hex</sub>                                                                                                                                                                                                                                                                                       | "C"               | Binary encoding scheme (represented using C-language notation in Part III of this Recommendation)                                                                                         |
+| C5 <sub>hex</sub> <sup>a)</sup>                                                                                                                                                                                                                                                                         | "E"               | Readable text, organized as lines of keyword/parameter pairs. The character set utilized shall correspond to an EBCDIC coded character set                                                |
+| 49 <sub>hex</sub>                                                                                                                                                                                                                                                                                       | "I"               | Readable text, organized as lines of keyword/parameter pairs. The character set utilized shall correspond to the APPLI/COM Standard ASCII character set (see Table 53)                    |
+| 50 <sub>hex</sub>                                                                                                                                                                                                                                                                                       | "P"               | The TDD presentation and syntax shall be regarded as being defined by private rules                                                                                                       |
+| Other values                                                                                                                                                                                                                                                                                            |                   | All other values not listed above are reserved for future standardization                                                                                                                 |
+| <sup>a)</sup> If this Code-ID has to appear in the ICE, its binary value shall be made in accordance to the code presentation chosen for the ICE itself, i.e. if the Code-ID of the ICE Header is "I" (APPLI/COM Standard ASCII) then the binary value of the "E" shall be coded as 45 <sub>hex</sub> . |                   |                                                                                                                                                                                           |
+
+TABLE 15/T.611
+
+##### **Mapping of keyword/parameter pairs for Text Based Encoding**
+
+(A ↵ denotes the new line format effector)
+
+| Syntax Element     | Keyword/Parameter Pair                  |
+|--------------------|-----------------------------------------|
+| <CancelFunction>   | "FUNCTION" ":" "Cancel" ↵               |
+| <Check>            | "CHECK" ":" <Convert-id-parameter> ↵    |
+| <CheckFunction>    | "FUNCTION" ":" "Check" ↵                |
+| <ComId>            | "COMID" ":" <Com-id-parameter> ↵        |
+| <Comment>          | "COMMENT" ":" <Comment-parameter> ↵     |
+| <ConvertFunction>  | "FUNCTION" ":" "Convert" ↵              |
+| <CopyFunction>     | "FUNCTION" ":" "Copy" ↵                 |
+| <Delete>           | "DELETE" ":" <Boolean-parameter> ↵      |
+| <DeleteFunction>   | "FUNCTION" ":" "Delete" ↵               |
+| <Direction>        | "DIRECTION" ":" <Direction-parameter> ↵ |
+| <Dispatched>       | "DISPATCHED" ":" <Boolean-parameter> ↵  |
+| <DispatchFunction> | "FUNCTION" ":" "Dispatch" ↵             |
+| <Error>            | "ERROR" ":" <Error-parameter> ↵         |
+
+TABLE 15/T.611 (end)
+
+##### **Mapping of keyword/parameter pairs for Text Based Encoding**
+
+(A ↵ denotes the new line format effector)
+
+| Syntax Element       | Keyword/Parameter Pair                                        |
+|----------------------|---------------------------------------------------------------|
+| <ExtendFunction>     | "FUNCTION" ":" "Extend" ↵                                     |
+| <FileName>           | "FILENAME" ":" <Path-parameter> ↵                             |
+| <InFormat>           | "INFORMAT" ":" <Convert-id-parameter> ↵                       |
+| <LaId>               | "LA-ID" ":" <La-id-parameter> ↵                               |
+| <LastTime>           | "LASTTIME" ":" <Date-time-parameter> ↵                        |
+| <Layout>             | "LAYOUT" ":" <Layout-id-parameter> ↵                          |
+| <Minor>              | "MINOR" ":" <Error-parameter> ↵                               |
+| <NationalFunction>   | "FUNCTION" ":" "National" ↵                                   |
+| <NewLa>              | "NEWLA" ":" <La-id-parameter> ↵                               |
+| <OutFormat>          | "OUTFORMAT" ":" <Convert-id-parameter> ↵                      |
+| <Previewed>          | "PREVIEWED" ":" <Boolean-parameter> ↵                         |
+| <Printer>            | "PRINTER" ":" <Printer-id-parameter> ↵                        |
+| <PrintFunction>      | "FUNCTION" ":" "Print" ↵                                      |
+| <PrivateFunction>    | "FUNCTION" ":" "Private" ↵                                    |
+| <PurgeFunction>      | "FUNCTION" ":" "Purge" ↵                                      |
+| <ReceiveFunction>    | "FUNCTION" ":" "Receive" ↵                                    |
+| <ReceiveTime>        | "RCVTIME" ":" <Date-time-parameter> ↵                         |
+| <ReqId>              | "REQ-ID" ":" <Req-id-parameter> ↵                             |
+| <ReqRef>             | "REQREF" ":" <Req-id-parameter> ↵                             |
+| <RescheduleFunction> | "FUNCTION" ":" "Reschedule" ↵                                 |
+| <SendAckFunction>    | "FUNCTION" ":" "SendAck" ↵                                    |
+| <SendFunction>       | "FUNCTION" ":" "Send" ↵                                       |
+| <SendTime>           | "SENDTIME" ":" <Send-time-parameter> ↵                        |
+| <Service>            | "SERVICE" ":" <Service-parameter> ↵                           |
+| <State>              | "STATE" ":" <State-parameter> ↵                               |
+| <Status>             | "STATUS" ":" <Status-parameter> ↵                             |
+| <SubFunction>        | "SUBFUNC" ":" <Subfunc-parameter> ↵                           |
+| <Target>             | "TARGET" ":" <Path-parameter> ↵                               |
+| <TimeRange>          | "RANGE" ":" <Date-time-parameter> "," <Date-time-parameter> ↵ |
+| <UserKey>            | "USERKEY" ":" <Userkey-parameter> ↵                           |
+| <Warning>            | "WARNING" ":" <Error-parameter> ↵                             |
+
+To improve the legibility of the TDD, all keyword/parameter pairs that appear shall be formatted by the use of format effectors. Following rules apply:
+
+- the syntax elements shall be arranged as lines of keyword/parameter pairs;
+- the FUNCTION keyword must be always the first keyword presented; if a SUBFUNC keyword exists for the TDD it must be second; the order of all other keywords is undefined;
+
+- the line shall be terminated by a new line format effector (see Table **Error! Bookmark not defined.**);
+- the parameter shall be separated from the keyword by a colon (":" character);
+- each line may contain a comment. The comment shall be introduced by a ";" character and extends to the end of the line. The comment is not interpreted by the CA. If a statement has to contain a ";" character, it shall be escaped with a backslash ("\\" character);
+- a line may contain white space format effectors (see Table **Error! Bookmark not defined.**);
+- the keywords are not case sensitive (upper case and lower case are treated equally);
+- the parameter presentation is not case sensitive as well, except in those cases where it is required by the service or the underlying operating system.
+
+A Request TDD contains input parameters. The Response TDD may contain output parameters. The CA shall respect following building rules for the Response TDD<sup>3)</sup>:
+
+- all input parameters of the Request TDD shall be returned in the Response TDD;
+- at minimum all output parameters declared basic shall be put into the Response TDD by the CA;
+- the order of the parameters contained in the Request TDD may be changed by the CA, except that the FUNCTION keyword shall be the first keyword presented, followed by the SUBFUNC keyword if applicable;
+- the case of the parameters contained in the Request TDD may be changed by the CA;
+- comments contained in the Request TDD may be stripped.
+
+TABLE 16/T.611
+
+##### **Format effectors for the Text Based Encoding**
+
+| Format effector | Code-ID dependent coding                 |                                          |                   |                                          |
+|-----------------|------------------------------------------|------------------------------------------|-------------------|------------------------------------------|
+|                 | "A"                                      | "B"                                      | "E"               | "I"                                      |
+| New line        | 0D0A <sub>hex</sub> or 0A <sub>hex</sub> | 0D0A <sub>hex</sub> or 0A <sub>hex</sub> | For further study | 0D0A <sub>hex</sub> or 0A <sub>hex</sub> |
+| White space     | 20 <sub>hex</sub> or 09 <sub>hex</sub>   | 20 <sub>hex</sub> or 09 <sub>hex</sub>   | For further study | 20 <sub>hex</sub> or 09 <sub>hex</sub>   |
+
+Subclause 6.6 tells in detail which TDD parameters are used as input and which are used as output parameters.
+
+#### 6.4.2 Mapping of Keywords
+
+#### 6.4.3 Encoding of the TDD Header
+
+In every TDD (and within the ICE) the <TDD Header> is always the first element specified. The <TDD Header> is structured as shown below (for explanation of the BNF-based grammar see A.1):
+
+<TDD Header> := <Code-ID> <Identification> <Version> <Standard> <Reserved>  
+ <Code-ID> := "A" | "B" | "E" | "I"  
+ -- for presentation of the Code-ID see also Table **Error! Bookmark not defined.**
+
+<sup>3)</sup> These rules have changed considerably compared to the 1992 version of this Recommendation. The rules defined there are far more strict.
+
+<Identification> :=        "\*APPLI/COM\*"
+
+<Version> :=                "1994"  
+                               -- <Version> denotes year of approval of this Recommendation
+
+<Standard> :=                "\*ITU-T\*"
+
+<Reserved> :=                STRING (SIZE(0..16))  
+                               -- <Reserved> is reserved for further extensions of this  
+                               -- Recommendation
+
+NOTE – The <TDD Header> syntax element contains the Code-ID as first element.
+
+#### 6.4.4 Encoding of Non Service Dependent Parameters
+
+This subclause defines the encoding of the non service dependent parameters addressed in Table **Error! Bookmark not defined.** Service-dependent parameters are mentioned in 6.4.5. They are fully specified in the relevant subclauses of Part II of this Recommendation.
+
+##### 6.4.4.1 Boolean-parameter
+
+The Boolean-parameter is encoded as a STRING taking the presentations "YES" or "NO".
+
+*General Syntax:*
+
+<Boolean-parameter> :=        "YES" | "NO"
+
+##### 6.4.4.2 Com-id-parameter
+
+The Com-id-parameter is encoded as a STRING containing the Communication-ID (COM-ID) computed by the CA. See also 5.4.1.
+
+*General Syntax:*
+
+<Com-id-parameter> :=        STRING
+
+##### 6.4.4.3 Comment-parameter
+
+The Comment-parameter is encoded as a STRING containing the Comment the LA specifies for the specific communication event.
+
+*General Syntax:*
+
+<Comment-parameter> :=        STRING
+
+##### 6.4.4.4 Date-time-parameter
+
+The Date-time-parameter is encoded as a STRING containing the date and time following the conventions "YY-MM-DD-HH:MM" (year-month-day-hour:minutes).
+
+*General Syntax:*
+
+<Date-time-parameter> :=        <year> "-" <month> "-" <day> "-" <hours> ":" <minutes>
+
+<year> :=                        <digit> <digit>
+
+<month> :=                        "0" | "1" <digit>
+
+<day> :=                          "0" | ... | "3" <digit>
+
+<hours> :=                        "0" | ... | "2" <digit>
+
+<minutes> :=                      "0" | ... | "5" <digit>
+
+<digit> :=                        "0" | ... | "9"
+
+##### 6.4.4.5 Direction-parameter
+
+The Direction-parameter is encoded as a STRING which can take the presentations "XMIT" or "RECEIVE".
+
+*General Syntax:*
+
+<Direction-parameter> := "XMIT" | "RECEIVE"
+
+##### 6.4.4.6 Error-parameter
+
+The Error-parameter is encoded as a structured STRING with the following layout:
+
+"nnnn"/"Text..."
+
+"nnnn" stands for a 4-digit, right-justified error number, filled to the left with "0"s. "0000" = success (no error). The value of the error number itself depends on the communications software used. Error codes are counted decimal. For the assignment of the error-code ranges refer to Table **Error! Bookmark not defined.** of 5.2.3.
+
+"Text..." stands for a plain text with a length of up to 79 characters that describes the error. If the parameter field is not long enough to accept plain text, the text is abbreviated as necessary. The plain text for error number "0000" is "Success".
+
+The error numbers which may be assigned are detailed in 5.2.3 and Annex C respectively.
+
+*General Syntax:*
+
+<Error-parameter> := <digit> <digit> <digit> <digit> / STRING(SIZE(0..79))
+
+<digit> := "0" | ... | "9"
+
+##### 6.4.4.7 La-id-parameter
+
+The La-id-parameter contains the reference of a LA-ID. It is presented as a STRING. The purpose of the parameter is to identify the "owning" LA of a request.
+
+*General Syntax:*
+
+<La-id-parameter> := STRING
+
+##### 6.4.4.8 Layout-id-parameter
+
+The Layout-id-parameter is encoded as NUMERIC-STRING, which can take the values "0", "1" or "2".
+
+*General Syntax:*
+
+<Layout-id-parameter> := "0" | "1" | "2"
+
+##### 6.4.4.9 Path-parameter
+
+The Path-parameter is encoded as PATH.
+
+*General Syntax:*
+
+<Path-parameter> := STRING  
+-- limited to the platform-specific file naming conventions
+
+##### 6.4.4.10 Printer-id-parameter
+
+The Printer-id-parameter contains the ID of a selected printer, encoded as a STRING. The contents of the STRING depends on the supporting operating system. The CA manufacturer shall state in his documentation how to address printers.
+
+*General Syntax:*
+
+<Printer-id-parameter> := STRING
+
+##### 6.4.4.11 Req-id-parameter
+
+The Req-id-parameter contains the REQ-ID (see 5.4.3). The parameter value is represented as a STRING. The purpose of the parameter is to identify the relation of a response to a previous request. So the REQ-ID shall be unique within a LA. It is the responsibility of the LA to ensure the REQ-ID is unique.
+
+*General Syntax:*
+
+<Req-id-parameter> := STRING
+
+##### 6.4.4.12 Send-time-parameter
+
+The Send-time-parameter is encoded as a STRING containing the date and time following the conventions "YY-MM-DD-HH:MM" (year-month-day-hour:minutes) or a specific indication for immediate or urgent treatment.
+
+*General Syntax:*
+
+<Send-time-parameter> := "IMMEDIATE" | "URGENT" | <Date-time-parameter>  
+-- *The <Date-time-parameter> is described in 6.4.4.4*
+
+##### 6.4.4.13 State-parameter
+
+The State-parameter specifies the state of the CA-Record. It is encoded as STRING and may take one of the values shown below:
+
+|             |                                                                                                                                                                     |
+|-------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| "delayed"   | concerns transmission: the record has not yet been processed by the CA.                                                                                             |
+| "sending"   | concerns transmission: the record is being processed by the CA for transmission.                                                                                    |
+| "sent"      | concerns transmission: the record has been successfully transmitted to the recipient.                                                                               |
+| "failed"    | concerns transmission and reception: the record failed to be fully transmitted or errors occurred during reception or an internal error inside of the CA did occur. |
+| "reception" | concerns reception: the record has been received but not yet retrieved.                                                                                             |
+| "retrieved" | concerns reception: the record has already been retrieved.                                                                                                          |
+
+*General Syntax:*
+
+<State-parameter> := "delayed" | "sending" | "sent" | "failed" | "reception" | "retrieved"
+
+##### 6.4.4.14 Status-parameter
+
+The Status-parameter reflects the status of a send or receive event. It may show the following STRING values:
+
+- "+" positive;
+- "+-" partially negative;
+- "-" negative;
+- "?" unknown.
+
+*General Syntax:*
+
+<Status-parameter> := "+" | "+-" | "-" | "?"
+
+##### 6.4.4.15 Subfunction-parameter
+
+The Subfunction-parameter is encoded as a STRING which specifies the Subfunction to be invoked.
+
+*General Syntax:*
+
+<Subfunction-parameter> := STRING
+
+##### 6.4.4.16 Userkey-parameter
+
+The Userkey-parameter is encoded as a STRING containing a User-key the LA specifies for the specific communication event.
+
+*General Syntax:*
+
+<Userkey-parameter> := STRING
+
+#### 6.4.5 Encoding of Service Specific Parameters
+
+This subclause describes some of the service specific parameters used in a similar fashion for various services. However, a full description of the parameters mentioned is given in the appropriate clauses of Part II of this Recommendation.
+
+##### 6.4.5.1 Service-id-parameter
+
+This parameter occurs in all send and receive TDDs. It specifies the service to be used. It is encoded as STRING and may take one of the following values:
+
+|         |                                                                         |
+|---------|-------------------------------------------------------------------------|
+| "FX3"   | for facsimile group 3 services                                          |
+| "FX4"   | for facsimile group 4 services                                          |
+| "TTX"   | for the teletex service                                                 |
+| "TX"    | for the telex via teletex facilities service (without dialogue ability) |
+| "TLX"   | for the telex service                                                   |
+| "EMAIL" | for e-mail services                                                     |
+| "FT"    | for file transfer services                                              |
+
+*General Syntax:*
+
+<Service-id-parameter> := "FX3" | "FX4" | "TTX" | "TX" | "TLX" | "EMAIL" | "FT"
+
+##### 6.4.5.2 File-of-addrspec and Address-parameter
+
+These parameters appear in all send and receive TDDs and is used in a similar fashion throughout all services.
+
+The File-of-addrspec parameter is encoded as PATH which points to a file containing Addrspec-parameters, which contain the Address-parameter.
+
+The Address-parameter is encoded as STRING. For some telecommunications services this string may be further restricted.
+
+*General Syntax:*
+
+<File-of-addrspec> := PATH  
+-- Path to a file containing a list of <Addrspec-parameter>s
+
+<Addrspec-parameter> := <Address-parameter> <Other-parameters>  
+-- The <Addrspec-parameter> itself is fully detailed for each service  
+-- in the appropriate clause of Part II of this Recommendation.
+
+<Address-parameter> := -- fully detailed in the appropriate clauses of Part II of this  
+-- Recommendation.
+
+##### 6.4.5.3 Convert-id-parameter
+
+This parameter appears in various TDDs. Some of them, i.e. the send and receive TDDs are service dependent.
+
+In all cases the Convert-id-parameter is encoded as a STRING and contains the Convert-ID, which specifies the transfer format. See also 5.4.5, clause 8 and Table H.**Error! Bookmark not defined.** as well as the appropriate clauses of Part II of this Recommendation for more information about the Convert-ID.
+
+*General Syntax:*
+
+<Convert-id-parameter> := STRING
+
+##### 6.4.5.4 Type-id-parameter
+
+This parameter appears in all send and receive TDDs and is used in a similar fashion throughout all services.
+
+The Type-id-parameter is encoded as a STRING and contains the Type-ID, which specifies the Transmission Format. See also 5.4.6, and Table H.**Error! Bookmark not defined.** as well as the appropriate clauses of Part II of this Recommendation for more information about the Type-ID.
+
+*General Syntax:*
+
+<Type-id-parameter> := STRING
+
+##### 6.4.5.5 File-of-filespec and File-parameter
+
+This parameter appears in all send and receive TDDs and is used in a similar fashion throughout all services. The File-of-filespec parameter is encoded as a PATH which points to a file containing Filespec-parameters, which contain the File-parameter.
+
+The File-parameter itself is also encoded as PATH, which points to the file transferred.
+
+*General Syntax:*
+
+<File-of-filespec> := PATH  
+-- Path to a file containing a list of <Filespec-parameter>s
+
+<Filespec-parameter> := <File-parameter> <Other-parameters>  
+-- The <Filespec-parameter> itself is fully detailed for each service  
+-- in the appropriate clause of Part II of this Recommendation.
+
+<File-parameter> := PATH  
+-- Path to the file transferred.
+
+### 6.5 Handling of Documents
+
+#### 6.5.1 Definitions used
+
+Some telecommunications services offer the possibility to transport a single file or a collection of files within a single communication event. The following definitions are useful:
+
+**6.5.1.1 document:** A document is regarded to be a piece of information belonging to a common context which shall be (or has been) transmitted within a session through an underlying telecommunications or communications service. A document may consist of several files.
+
+**6.5.1.2 session:** A session is an association between two end systems, which allows the end systems to interchange data without loss or visible interruption.
+
+**6.5.1.3 file:** A file is a compilation of data as it is maintained by the underlying operating system.
+
+#### 6.5.2 Sending documents
+
+Following functionality for sending documents is supported:
+
+- send a document, consisting of one file, to one or many addressees;
+- send a document, consisting of many files, to one or many addressees.
+
+In order to successfully exchange a document via a telecommunications service, at least three items need to be specified:
+
+- the path to the file (or the paths to the files) making up the document;
+- the Transfer Format (Convert-ID), in which the document is exchanged between LA and CA;
+- the Transmission Format (Type-ID), in which the document is exchanged via the network.
+
+If the documents consists of one file, the path to the file may be given in the <Document> syntax element, the Transmission Format in the <Type> syntax element and the Transfer Format in the <Convert> syntax element. Since these syntax elements are service dependent in their values, they are described for each service in Part II of this Recommendation.
+
+If the document consists of more files, the three components shall be gathered conforming to a service specific syntax. Since this syntax is service specific, it is also described for each service in Part II of this Recommendation. According to this syntax, the gathered components shall be put into an indirection file by the LA. The path to this indirection file then shall be specified in the appropriate syntax element of the TDD.
+
+NOTE – The path to an indirection file is always specified with a leading "@" character.
+
+#### 6.5.3 Receiving documents
+
+Following functionality for receiving documents is supported:
+
+- receive a document, consisting of one file;
+- receive a document, consisting of many files.
+
+If a received document consists of many files, the CA builds an indirection file as described in 6.5.2 and prepends the path of the file with a "@" character.
+
+If the received document consists of one file, the path (optionally) given by the LA shall be used to store the document itself. The Transmission Format then will be returned in the <Type>, the Transfer Format in the <Convert> syntax element.
+
+#### 6.5.4 Format of the indirection file
+
+The indirection file contains lines of service specific syntax elements, one line for each file. The code presentation shall conform to the Code-ID used for TDDs. For a generic description of the syntax elements contained in the indirection file refer to 6.4.5.5.
+
+NOTE – The indirection file shall be processed in order of appearance.
+
+### 6.6 TDD Functionality
+
+This subclause describes the functionality which is triggered by the Request TDDs. It gives information how the syntax elements shall be used in the request and in the response. Table **Error! Bookmark not defined.** explains the columns of the TDD tables used in the following subclauses.
+
+TABLE 17/T.611
+
+#### **Explanation of the column headlines for the TDD tables**
+
+| Column             | Content                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
+|--------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Syntax Element     | Lists the syntax elements used for the TDD                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
+| C (Class)          | Stands for the class of the keyword. "B" stands for basic, which means that the keyword shall be supported by all CAs, "+" means the keyword is supported by the CA if and only if the keyword is declared in the ICE                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
+| T (Type)           | Specifies whether the keyword is mandatory ("m") or optional ("o"). When the keyword is optional, then the "Default" cell specifies a default value for the parameter                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
+| I/O (Input/Output) | <p>The Input/Output column lists the requirements concerning the parameter following the keyword in the request and the response</p> <p>When the column states "I", it means the parameter contains an "input" value, i.e. the CA shall interpret the value as the one requested by the LA. The CA shall not modify the value and return it in the response</p> <p>When the column states "I/O", it means the parameter contains an "input" value (like when "I" is specified) and an "output" value is expected (i.e. set by the CA in the Response TDD)</p> <p>When the column states "O", it means the parameter is an "output" value (i.e. set by the CA in the Response TDD) and no value shall be set in the request (i.e. no parameter value shall be specified in the request). The response shall contain the value used for that parameter by the CA</p> |
+| Keyword            | Gives the name of the keyword as it reads in the TDD when it is encoded as readable text. Case is NOT significant, e.g. "Function" and "funcTion" shall be interpreted equally. See also 6.4.1                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
+| Parameter          | Lists the possible values for the parameter when it is encoded as readable text. The mapping of the parameter types is described in 6.4.4                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
+| Default            | Lists the default values for the parameter (when applicable, i.e. when the "Type" cell reads "O")                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
+| Comment            | Gives short explanation for the use of the keywords and parameters                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
+
+The general rules to be used are:
+
+- A given TDD (request and response) belongs to a Functional Class. As a consequence, the related keywords do not depend on the Functional Class.
+- Keywords are divided into two categories: basic and additive ("+"). Additive keywords can be used by LAs only if they are declared in the ICE (CA-Descriptor). Basic keywords are supported by all CAs.
+- The use or not of a keyword has the same signification for both basic and additive keywords.
+- If a keyword is absent in a TDD, then the default value of the parameter applies. A default value is always an input parameter, i.e. the "Input/Output" classification is always "I".
+- When a parameter is classified as "I" (input), then the CA shall not modify the value in the Response TDD.
+
+Table **Error! Bookmark not defined.** explains how the "Type" and "Input/Output" classifications are used:
+
+TABLE 18/T.611
+
+#### **Usage of "Type" and "Input/Output" classifications**
+
+| Type | Input/Output | The Keyword                                                                                                                                                                                                                                                                                                                                                      |
+|------|--------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| "m"  | "I"          | Shall be specified in the request; a parameter value shall also be specified. In the response, the keyword is also specified, with its parameter value unchanged                                                                                                                                                                                                 |
+|      | "O"          | Shall be specified in the request with an empty parameter value. In the response, the keyword is also present, with a significant parameter value                                                                                                                                                                                                                |
+|      | "I/O"        | Shall be specified in the request; the parameter value shall also be specified. In the response, the keyword is also specified, with a possibly different parameter value. The parameter value in the response is significant                                                                                                                                    |
+| "o"  | "I"          | In the request, the keyword may be present or not; if absent, the default value applies. The response may include the keyword only if it was specified in the request; in this case, the parameter value is unchanged                                                                                                                                            |
+|      | "O"          | May be specified in the request (without any parameter value) if it is desired to obtain a response parameter value for the keyword; in this case, a parameter value must be specified in the response. Otherwise no response parameter value shall be returned. No default applies to the keyword                                                               |
+|      | "I/O"        | May be specified in the request with a parameter value. If not specified in the request, the default parameter value applies. In the response, the keyword is present only if it was present in the Request; in this case, the response parameter value is significant. If the request does not specify the keyword, then the response may not specify it either |
+
+#### 6.6.1 Send
+
+The <SendTDD> and the <SendAckTDD> are used to send one or more documents to one or more recipients. The <SendAckTDD> response acts as an acknowledgement of a previous request. For the <SendTDD> request no response is generated by the CA.
+
+The <SendTDD> may be used to send documents to any number of recipients. <SendAckTDD> allows for only one recipient per request. <SendAckTDD> is designed for those LAs that implement the Functional Class A only; they therefore need a completion report from the CA. <SendTDD> is designed for LAs that implement the Functional Class B; they therefore have the means to trace TDD requests via the Trace function. However, both type of LAs may use <SendTDD> and <SendAckTDD>.
+
+If a LA wants to send documents to a list of recipients, it shall use the <SendTDD> along with the <AddrList> syntax element. The transmission status (<Status> syntax element) is not available through this function, since no Response-TDD is generated. However, the status of the transmission can be obtained using the Trace:COPY functionality as described in 6.6.3.
+
+NOTE – The Trace functionality is only available through CAs conforming to Functional Class B (FCB).
+
+Two tables are provided: one for the <SendTDD>, the other for the <SendAckTDD> situation.
+
+The <SendAckTDD> response is always understood as a completion status, i.e. if the request succeeds, the response shall be generated at the completion of the <SendAckTDD> request processing. So, whenever the Response-TDD is available, the LA can rely definitely on contents of the status parameter showing the result of the transmission. The status parameter will indicate one of the following 4 statuses:
+
+- 1) document successfully and completely transmitted;
+- 2) transmission failed, all attempts to transmit are given up by CA;
+
+- 3) transmission partially failed, parts are already transmitted, but no complete transmission could be achieved;
+- 4) status unknown.
+
+The <SendTDD> and the <SendAckTDD> are belonging to Functional Classes A and B.
+
+If multiple recipients are specified in a <SendAckTDD> request, then the <Status> and <Error> may not be specified (see Tables 19 and 20).
+
+TABLE 19/T.611
+
+##### **Syntax elements of the <SendAckTDD>**
+
+| Syntax Element    | C | T | I/O | Text Based Encoding |                        |              | Comment                                                                                                              |
+|-------------------|---|---|-----|---------------------|------------------------|--------------|----------------------------------------------------------------------------------------------------------------------|
+|                   |   |   |     | Keyword             | Parameter              | Default      |                                                                                                                      |
+| <SendAckFunction> | B | m | I   | FUNCTION            | "SendAck"              | –            | CA shall generate a response                                                                                         |
+| <LaId>            | B | m | I   | LA-ID               | <La-id-parameter>      | –            |                                                                                                                      |
+| <ReqID>           | B | m | I   | REQ-ID              | <Req-id-parameter>     | –            |                                                                                                                      |
+| <Service>         | B | m | I   | SERVICE             | <Service-id-parameter> | –            |                                                                                                                      |
+| <Error>           | B | m | O   | ERROR               | <Error-parameter>      | –            | The error returned by the CA                                                                                         |
+| <Status>          | B | m | O   | STATUS              | <Status-parameter>     | –            | Returns status from the CA                                                                                           |
+| <ComId>           | B | o | O   | COMID               | <Com-id-parameter>     | –            | Identification of the communication (computed by the CA)                                                             |
+| <SendTime>        | B | o | I   | SENDTIME            | <Send-time-parameter>  | "IMMEDIATE"  | CA shall actually process the request at the time specified                                                          |
+| <Comment>         | + | o | I   | COMMENT             | <Comment-parameter>    | –            |                                                                                                                      |
+| <LastTime>        | + | o | I   | LASTTIME            | <Date-time-parameter>  | CA dependent | Latest time for processing the request expressed as an absolute time                                                 |
+| <Minor>           | + | o | O   | MINOR               | <Error-parameter>      | –            |                                                                                                                      |
+| <UserKey>         | + | o | I   | USERKEY             | <Userkey-parameter>    | –            | Request and response shall contain the same parameter value. The CA shall not interpret this parameter in any manner |
+| <Warning>         | + | o | O   | WARNING             | <Error-parameter>      | –            |                                                                                                                      |
+
+TABLE 20/T.611
+
+##### **Syntax elements of the <SendTDD>**
+
+| Syntax Element | C | T | I/O | Text Based Encoding |                        |              | Comment                                                              |
+|----------------|---|---|-----|---------------------|------------------------|--------------|----------------------------------------------------------------------|
+|                |   |   |     | Keyword             | Parameter              | Default      |                                                                      |
+| <SendFunction> | B | m | I   | FUNCTION            | "Send"                 | –            | CA shall NOT generate a response                                     |
+| <Lald>         | B | m | I   | LA-ID               | <La-id-parameter>      | –            |                                                                      |
+| <ReqId>        | B | m | I   | REQ-ID              | <Req-id-parameter>     | –            |                                                                      |
+| <Service>      | B | m | I   | SERVICE             | <Service-id-parameter> | –            |                                                                      |
+| <SendTime>     | B | o | I   | SENDTIME            | <Send-time-parameter>  | "IMMEDIATE"  | CA shall actually process the request at the time specified          |
+| <Comment>      | + | o | I   | COMMENT             | STRING                 | –            |                                                                      |
+| <LastTime>     | + | o | I   | LASTTIME            | <Date-Time-parameter>  | CA-dependent | Latest time for processing the request expressed as an absolute time |
+| <UserKey>      | + | o | I   | USERKEY             | STRING                 | –            | The CA shall not interpret this parameter in any manner              |
+
+#### **6.6.2 Receive**
+
+The <ReceiveTDD> requests for retrieval of an incoming document already received by the CA. The <ReceiveTDD> belongs to Functional Classes A and B (see Table 21).
+
+The request specifies the telecommunications service, the storage area for the incoming file and the desired Transfer Format. For some services, the recipient's sub-address can also be used as a selector (see appropriate clause of Part II of this Recommendation).
+
+In order to retrieve (receive) a document, the LA may use two different approaches:
+
+- either the LA retrieves what comes next without any pre-selections, in this case the LA must be able to properly handle the received document independent of the document Transfer Format;
+- or the LA first inspects a copy of a list of received documents by using the Trace <CopyTDD> request. With that list, the LA may obtain the COM-ID of the document it wishes to retrieve. This is possible only if the CA supports Functional Class B and the LA supports the <CopyTDD> function.
+
+The <Convert> syntax element is used to store the actual Transfer Format of the document inside the Response TDD. The <Status> and <Error> syntax elements are necessary to convey the status and error code of the receive event. If the LA knows the COM-ID of the document it wishes to retrieve, it may also specify the <ComId> syntax element in the request in order to extract that document.
+
+The *additive* <Delete> syntax element controls document deletion within the CA. For normal operation, <Delete> shall be true and the CA shall remove the document from its storage after document transfer. Thus, a document can only be received once, forcing the CA-Record into the "retrieved" state, as described in 5.6.7.1.
+
+If <Delete> is set to false, the document shall be kept by the CA and the CA-Record shall remain in the reception state. As a consequence, on the next attempt the same document might be retrieved again.
+
+NOTE – The CA implementation may decide to perform the deletion only virtually and may keep the "deleted" documents internally, e.g. to make them available for other LAs or to keep them for archiving purposes.
+
+TABLE 21/T.611
+
+##### **Syntax elements of the <ReceiveTDD>**
+
+| Syntax Element    | C | T | I/O | Text Based Encoding |                        |         | Comment                                                                                                 |
+|-------------------|---|---|-----|---------------------|------------------------|---------|---------------------------------------------------------------------------------------------------------|
+|                   |   |   |     | Keyword             | Parameter              | Default |                                                                                                         |
+| <ReceiveFunction> | B | m | I   | FUNCTION            | "Receive"              | –       |                                                                                                         |
+| <Lald>            | B | m | I   | LA-ID               | <La-id-parameter>      | –       |                                                                                                         |
+| <ReqId>           | B | m | I   | REQ-ID              | <Req-id-parameter>     | –       |                                                                                                         |
+| <Error>           | B | m | O   | ERROR               | <Error-parameter>      | –       | The error returned by the CA                                                                            |
+| <Status>          | B | m | O   | STATUS              | <Status-parameter>     | –       | Returns status from the CA. When no document is available, the Response TDD shall specify the value "–" |
+| <ComId>           | B | o | I/O | COMID               | <Com-id-parameter>     | –       | Identification of the communication (computed by the CA)                                                |
+| <Service>         | B | o | I/O | SERVICE             | <Service-id-parameter> | –       | If used in the Request, used as a selection criterion                                                   |
+| <Delete>          | + | o | I   | DELETE              | <Boolean-parameter>    | "Yes"   | If true, CA shall delete retrieved document from its internal buffer                                    |
+| <Minor>           | + | o | O   | MINOR               | <Error-parameter>      | –       |                                                                                                         |
+| <ReceiveTime>     | + | o | O   | RCVTIME             | <Date-time-parameter>  | –       | Time of the document reception by the CA                                                                |
+| <Warning>         | + | o | O   | WARNING             | <Error-parameter>      | –       |                                                                                                         |
+
+#### 6.6.3 Trace
+
+The TDDs belonging to the Trace group are used to manage the CA-Records. The Trace functionality is specific to Functional Class B.
+
+The purpose of the various TDDs is to control the operation of a CA. Following TDDs are defined:
+
+- <PurgeTDD> to PURGE any CA-Records in "failed", "retrieved" and "sent" states; this feature is useful to clear the CA-Records which have reached an inactive state;
+- <CopyTDD> to COPY any CA-Records in any state into a file; this feature is useful to build what is commonly known as "journals" or "logs";
+- <CancelTDD> to CANCEL any CA-Record in the "sending" state; this feature allows the LA to interrupt and terminate the transmission that the CA is performing<sup>4)</sup>;
+- <DeleteTDD> to DELETE any CA-Record in the "delayed" state in order to cancel it;
+- <RescheduleTDD> to RESCHEDULE any CA-Record in the "failed" state to give the CA a chance to re-transmit it; this feature facilitates the management of transmissions that failed because the recipient was busy or the request was badly formed, for example;
+- <DispatchTDD> to DISPATCH any CA-Record in the "reception" state to assign it to the actual recipient LA;
+- <PreviewTDD> to PREVIEW a document associated with a CA-Record in the "reception" state.
+
+It should be noted that all requests are performed on the behalf of a given LA (through the LA-ID). This limits the scope of the functions above to those CA-Records assigned to that LA-ID (except for the obvious situations where the LA-ID is not specified).
+
+In order to delete a previous request being in the "send" state, the <DeleteTDD> shall be used.
+
+If known, the LA may specify the <ComId> syntax element instead of the <ReqRef> syntax element.
+
+##### 6.6.3.1 Trace:DELETE
+
+See Table 22.
+
+##### 6.6.3.2 Trace:COPY
+
+In order to get a copy of CA-Records which refers to a specific state, the <CopyTDD> shall be used.
+
+The <State> syntax element specifies the state of the CA-Records intended to be copied. The <Target> syntax element specifies the path to the file into which the CA will generate its output. <Error> is used to store the error code of the operation in the Response-TDD. The copied list is always in the format implied by the Code-ID of the requesting TDD. The layout of the list is implied by the RECORDS entry of the ICE. The order of the fields in the target list shall be the same as the order in which the corresponding keywords are declared by the RECORD entry.
+
+If known, the LA may specify the <ComId> syntax element instead of the <ReqRef> syntax element.
+
+The optional <Layout> syntax element can be used to specify the layout of the resulting copy. The values this parameter may take are explained in Table **Error! Bookmark not defined.**, examples are given in Figures **Error! Bookmark not defined.** and **Error! Bookmark not defined.**. The character representation of the copy is implied by the <TDD Header> of the corresponding <CopyTDD> (see Table 24).
+
+---
+
+<sup>4)</sup> It is not guaranteed that the cancel operation succeeds because of the nature of the interface.
+
+TABLE 22/T.611
+
+###### **Syntax elements of the <DeleteTDD>**
+
+| Syntax Element                 | C | T | I/O | Text Based Encoding |                    |         | Comment                                                |
+|--------------------------------|---|---|-----|---------------------|--------------------|---------|--------------------------------------------------------|
+|                                |   |   |     | Keyword             | Parameter          | Default |                                                        |
+| <DeleteFunction>               | B | m | I   | FUNCTION            | "Delete"           | –       | Deletes CA-Records in the "delayed" state              |
+| <Lald>                         | B | m | I   | LA-ID               | <La-id-parameter>  | –       |                                                        |
+| <ReqId>                        | B | m | I   | REQ-ID              | <Req-id-parameter> | –       |                                                        |
+| <Error>                        | B | m | O   | ERROR               | <Error-parameter>  | –       | The error returned by the CA                           |
+| <Minor>                        | + | o | O   | MINOR               | <Error-parameter>  | –       |                                                        |
+| <Warning>                      | + | o | O   | WARNING             | <Error-parameter>  | –       |                                                        |
+| Use of <ComId> syntax element  |   |   |     |                     |                    |         |                                                        |
+| <ComId>                        | B | m | I   | COMID               | <Com-id-parameter> | –       | Identification of the communication computed by the CA |
+| Use of <ReqRef> syntax element |   |   |     |                     |                    |         |                                                        |
+| <ReqRef>                       | B | m | I   | REQREF              | <Req-id-parameter> | –       | Reference to a previous REQ-ID                         |
+
+TABLE 23/T.611
+
+###### **Impact of the <Layout> syntax element**
+
+| Layout-id | Explanation                                                                                                                                                                                                                                                                                                                                                             |
+|-----------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| 0         | Default value. The amount, layout and order of the fields presented in the resulting copy target are defined within the ICE by the RECORD entry. The RECORD entry gives the length of the fields and implies their order. The fields of a CA-Record are presented in one row, padded with SPACE to the length specified in the RECORD entry. A headline is not provided |
+| 1         | The fields are presented row by row as comma separated values (csv), included in apostrophes. The first field row contains the keywords the field column refers to. See also Figure 7                                                                                                                                                                                   |
+| 2         | The fields are presented row by row, separated by tabulator characters. The first field row contains the keywords the field column refers to. See also Figure 8                                                                                                                                                                                                         |
+
+```
+"COMID","DIRECTION","LA-ID","REQ-ID","STATE"
+```
+
+```
+"0001","xmit","Jonny","REQ-1212","delayed"
+```
+
+```
+"0002","xmit","Jonny","REQ-1213","sent"
+```
+
+```
+"0003","receive","Jonny","REQ-1214","retrieved"
+```
+
+FIGURE 7/T.611
+
+**Example of comma separated value layout (Layout-id = 1)**
+
+| COMID | DIRECTION | LA-ID | REQ-ID   | STATE     |
+|-------|-----------|-------|----------|-----------|
+| 0001  | xmit      | Jonny | REQ-1212 | delayed   |
+| 0002  | xmit      | Jonny | REQ-1213 | sent      |
+| 0003  | receive   | Jonny | REQ-1214 | retrieved |
+
+FIGURE 8/T.611
+
+**Example of tabulator separated value layout (Layout-id = 2)**
+
+TABLE 24/T.611
+
+###### Syntax elements of the <CopyTDD>
+
+| Syntax Element                 | C | T | I/O | Text Based Encoding |                        |                 | Comment                                                                                    |
+|--------------------------------|---|---|-----|---------------------|------------------------|-----------------|--------------------------------------------------------------------------------------------|
+|                                |   |   |     | Keyword             | Parameter              | Default         |                                                                                            |
+| <CopyFunction>                 | B | m | I   | FUNCTION            | "Copy"                 | –               | Copy all the CA-Records of a specific state into the file pointed to by the TARGET keyword |
+| <Lald>                         | B | m | I   | LA-ID               | <La-id-parameter>      | –               |                                                                                            |
+| <ReqId>                        | B | m | I   | REQ-ID              | <Req-id-parameter>     | –               |                                                                                            |
+| <State>                        | B | m | I   | STATE               | <State-parameter>      | All states      | State of the CA-Record                                                                     |
+| <Target>                       | B | m | I   | TARGET              | <Path-parameter>       | –               | Destination file name                                                                      |
+| <Error>                        | B | m | O   | ERROR               | <Error-parameter>      | –               | The error returned by the CA                                                               |
+| <Layout>                       | B | o | I   | LAYOUT              | <Layout-id-parameter>  | "0"             | Specifies layout of resulting copy                                                         |
+| <Direction>                    | B | o | I   | DIRECTION           | <Direction-parameter>  | Both directions |                                                                                            |
+| <Dispatched>                   | B | o | I   | DISPATCHED          | <Boolean-parameter>    | All CA-Records  |                                                                                            |
+| <Previewed>                    | B | o | I   | PREVIEWED           | <Boolean-parameter>    | All CA-Records  |                                                                                            |
+| <Service>                      | B | o | I   | SERVICE             | <Service-id-parameter> | All services    |                                                                                            |
+| <TimeRange>                    | B | o | I   | RANGE               | <Date-time-parameters> | All CA-Records  |                                                                                            |
+| <Minor>                        | + | o | O   | MINOR               | <Error-parameter>      | –               |                                                                                            |
+| <Warning>                      | + | o | O   | WARNING             | <Error-parameter>      | –               |                                                                                            |
+| Use of <ComId> syntax element  |   |   |     |                     |                        |                 |                                                                                            |
+| <ComId>                        | B | m | I   | COMID               | <Com-id-parameter>     | –               | Identification of the communication computed by the CA                                     |
+| Use of <ReqRef> syntax element |   |   |     |                     |                        |                 |                                                                                            |
+| <ReqRef>                       | B | m | I   | REQREF              | <Req-id-parameter>     | –               | Reference to a previous REQ-ID                                                             |
+
+##### 6.6.3.3 Trace: CANCEL
+
+To cancel a previous "send" request, the LA shall use the <CancelTDD> (see Table 25).
+
+If it is known, the LA may also specify the <ComId> syntax element instead of the <ReqRef> syntax element.
+
+NOTE – Cancellation of a Send Request may not succeed due to the nature of the interface.
+
+TABLE 25/T.611
+
+###### Syntax elements of the <CancelTDD>
+
+| Syntax Element                 | C | T | I/O | Text Based Encoding |                    |         | Comment                                                |
+|--------------------------------|---|---|-----|---------------------|--------------------|---------|--------------------------------------------------------|
+|                                |   |   |     | Keyword             | Parameter          | Default |                                                        |
+| <CancelFunction>               | B | m | I   | FUNCTION            | "Cancel"           | –       | Cancel a CA-Record generated by a previous request     |
+| <Lald>                         | B | m | I   | LA-ID               | <La-id-parameter>  | –       |                                                        |
+| <ReqId>                        | B | m | I   | REQ-ID              | <Req-id-parameter> | –       |                                                        |
+| <Error>                        | B | m | O   | ERROR               | <Error-parameter>  | –       | The error returned by the CA                           |
+| <Minor>                        | + | o | O   | MINOR               | <Error-parameter>  | –       |                                                        |
+| <Warning>                      | + | o | O   | WARNING             | <Error-parameter>  | –       |                                                        |
+| Use of <ComId> syntax element  |   |   |     |                     |                    |         |                                                        |
+| <ComId>                        | B | m | I   | COMID               | <Com-id-parameter> | –       | Identification of the communication computed by the CA |
+| Use of <ReqRef> syntax element |   |   |     |                     |                    |         |                                                        |
+| <ReqRef>                       | B | m | I   | REQREF              | <Req-id-parameter> | –       | Reference to a previous REQ-ID                         |
+
+##### 6.6.3.4 Trace: PURGE
+
+In order to purge CA-Records from the CA, the <PurgeTDD> shall be used (see Table 26).
+
+The <State> syntax element specifies the state of the CA-Records to be purged (see 5.6). The <Error> syntax element stores the error code of the operation in the Response-TDD.
+
+If known, the LA may also specify the <ComId> syntax element instead of the <ReqRef> syntax element.
+
+TABLE 26/T.611
+
+###### Syntax elements of the <PurgeTDD>
+
+| Syntax Element                                                                                                                                                            | C | T | I/O | Text Based Encoding |                    |                          | Comment                                                |
+|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---|---|-----|---------------------|--------------------|--------------------------|--------------------------------------------------------|
+|                                                                                                                                                                           |   |   |     | Keyword             | Parameter          | Default                  |                                                        |
+| <PurgeFunction>                                                                                                                                                           | B | m | I   | FUNCTION            | "Purge"            | –                        | Purge a CA-Record generated by a previous request      |
+| <LaId>                                                                                                                                                                    | B | m | I   | LA-ID               | <La-id-parameter>  | –                        |                                                        |
+| <ReqId>                                                                                                                                                                   | B | m | I   | REQ-ID              | <Req-id-parameter> | –                        |                                                        |
+| <State>                                                                                                                                                                   | B | m | I   | STATE               | <State-parameter>  | All states <sup>a)</sup> | State of the CA-Record                                 |
+| <Error>                                                                                                                                                                   | B | m | O   | ERROR               | <Error-parameter>  | –                        | The error returned by the CA                           |
+| <Minor>                                                                                                                                                                   | + | o | O   | MINOR               | <Error-parameter>  | –                        |                                                        |
+| <Warning>                                                                                                                                                                 | + | o | O   | WARNING             | <Error-parameter>  | –                        |                                                        |
+| Use of <ComId> syntax element                                                                                                                                             |   |   |     |                     |                    |                          |                                                        |
+| <ComId>                                                                                                                                                                   | B | m | I   | COMID               | <Com-id-parameter> | –                        | Identification of the communication computed by the CA |
+| Use of <ReqRef> syntax element                                                                                                                                            |   |   |     |                     |                    |                          |                                                        |
+| <ReqRef>                                                                                                                                                                  | B | m | I   | REQREF              | <Req-id-parameter> | –                        | Reference to a previous REQ-ID                         |
+| a) "All states" in this case stands for the states "sent", "failed" and "retrieved". Application of the "purge" functionality on other states shall be ignored by the CA. |   |   |     |                     |                    |                          |                                                        |
+
+##### 6.6.3.5 Trace:RESCHEDULE
+
+To reschedule a failed send Request, the <RescheduleTDD> shall be used. If known, the LA may also specify the <ComId> syntax element instead of the <ReqRef> syntax element (see Table 27).
+
+TABLE 27/T.611
+
+###### Syntax elements of the <RescheduleTDD>
+
+| Syntax Element                 | C | T | I/O | Text Based Encoding |                       |              | Comment                                                                        |
+|--------------------------------|---|---|-----|---------------------|-----------------------|--------------|--------------------------------------------------------------------------------|
+|                                |   |   |     | Keyword             | Parameter             | Default      |                                                                                |
+| <Reschedule-Function>          | B | m | I   | FUNCTION            | "Reschedule"          | –            | Reschedule a CA-Record generated by a previous send request                    |
+| <Lald>                         | B | m | I   | LA-ID               | <La-id-parameter>     | –            |                                                                                |
+| <ReqId>                        | B | m | I   | REQ-ID              | <Req-id-parameter>    | –            |                                                                                |
+| <Error>                        | B | m | O   | ERROR               | <Error-parameter>     | –            | The error returned by the CA                                                   |
+| <Address>                      | B | o | I   | ADDRESS             | <Address-parameter>   | –            | Used for the "reschedule" function only; specifies the new recipient's address |
+| <SendTime>                     | B | o | I   | SENDTIME            | <Send-time-parameter> | "IMMEDIATE"  | Process the request at the time specified                                      |
+| <LastTime>                     | + | o | I   | LASTTIME            | <Date-time-parameter> | CA dependent | Limit time for processing the request                                          |
+| <Minor>                        | + | o | O   | MINOR               | <Error-parameter>     | –            |                                                                                |
+| <Warning>                      | + | o | O   | WARNING             | <Error-parameter>     | –            |                                                                                |
+| Use of <ComId> syntax element  |   |   |     |                     |                       |              |                                                                                |
+| <ComId>                        | B | m | I   | COMID               | <Com-id-parameter>    | –            | Identification of the communication computed by the CA                         |
+| Use of <ReqRef> syntax element |   |   |     |                     |                       |              |                                                                                |
+| <ReqRef>                       | B | m | I   | REQREF              | <Req-id-parameter>    | –            | Reference to a previous REQ-ID                                                 |
+
+##### 6.6.3.6 Trace:DISPATCH
+
+To dispatch a received file to a LA, the <DispatchTDD> shall be used (see Table 28).
+
+The <NewLa> syntax element, which may be specified repeatedly, contains the LA-ID of the new LA. On successful return the new LA owns the received document and may retrieve it.
+
+NOTE – The use of the dispatch function may be restricted.
+
+TABLE 28/T.611
+
+###### Syntax elements of the <DispatchTDD>
+
+| Syntax Element     | C | T | I/O | Text Based Encoding |                    |         | Comment                                                                            |
+|--------------------|---|---|-----|---------------------|--------------------|---------|------------------------------------------------------------------------------------|
+|                    |   |   |     | Keyword             | Parameter          | Default |                                                                                    |
+| <DispatchFunction> | B | m | I   | FUNCTION            | "Dispatch"         | –       | Dispatches documents associated to the CA-Record designated by the COM-ID          |
+| <Lald>             | B | m | I   | LA-ID               | <La-id-parameter>  | –       |                                                                                    |
+| <ReqId>            | B | m | I   | REQ-ID              | <Req-id-parameter> | –       |                                                                                    |
+| <NewLa>+           | B | m | I   | NEWLA               | <La-id-parameter>  | –       | Specifies the name of the new "owner" of the document. Can be repeatedly specified |
+| <Error>            | B | m | O   | ERROR               | <Error-parameter>  | –       | The error returned by the CA                                                       |
+| <ComId>            | B | m | I   | COMID               | <Com-id-parameter> | –       | Identification of the communication computed by the CA                             |
+| <Minor>            | + | o | O   | MINOR               | <Error-parameter>  | –       |                                                                                    |
+| <Warning>          | + | o | O   | WARNING             | <Error-parameter>  | –       |                                                                                    |
+
+##### 6.6.3.7 Trace:PREVIEW
+
+The <PreviewTDD> allows an administrator of the CA to retrieve and dispatch the received documents, while still keeping them available (for further dispatching). The PREVIEW function acts like the Receive function except that the CA-Record stays in the reception state instead of changing to the received state (see Table 29).
+
+The CA-Record will also have to record whether the received document was viewed by the administrator, and whether the document was already dispatched. This allows a Trace:COPY function to search for the received documents that were not already viewed or dispatched to their final recipients.
+
+The following principles also apply:
+
+When the CA generates a CA-Record (called "primary" CA-Record for the purpose of the explanation) after receiving an incoming document, the primary CA-Record is assigned to the "Administrator" user. The primary CA-Record flags "viewed" and "dispatched" are set to "no".
+
+To dispatch the incoming document, the Administrator "previews" the document thanks to the Trace:PREVIEW function. The "viewed" primary CA-Record flag is then set to "yes". Then the Administrator dispatches the document to one or many recipients. The primary CA-Record flag "dispatched" is then set to "yes".
+
+A new copy of the primary CA-Record is generated internally for each recipient by the CA and has the following attributes:
+
+- State = Reception
+- LA-ID = Login name of the recipient to which it was dispatched
+- Viewed = "no"
+- Dispatched = "no"
+
+This CA-Record is called "secondary" CA-Record for the sake of clarity. Each secondary CA-Record is now owned by the recipient to which it was dispatched. The recipient can retrieve it with the usual Trace:COPY function, and receive it with the Receive function. If the system permits, the user might also dispatch or preview the received document thanks to the same function calls.
+
+This mechanisms allows the administrator of the CA to list all the recipients of a given document, watch who has retrieved them, redispach a document on demand, etc.
+
+TABLE 29/T.611
+
+###### **Syntax elements of the <PreviewTDD>**
+
+| Syntax Element    | C | T | I/O | Text Based Encoding |                        |         | Comment                                                                  |
+|-------------------|---|---|-----|---------------------|------------------------|---------|--------------------------------------------------------------------------|
+|                   |   |   |     | Keyword             | Parameter              | Default |                                                                          |
+| <PreviewFunction> | B | m | I   | FUNCTION            | "Preview"              | –       | Retrieves documents associated to the CA-Record designated by the COM-ID |
+| <LaId>            | B | m | I   | LA-ID               | <La-id-parameter>      | –       |                                                                          |
+| <ReqId>           | B | m | I   | REQ-ID              | <Req-id-parameter>     | –       |                                                                          |
+| <ComId>           | B | m | I   | COMID               | <Com-id-parameter>     | –       | Identification of the communication computed by the CA                   |
+| <Convert>         | B | m | O   | CONVERT             | <Convert-id-parameter> | –       | Transfer format of the target file                                       |
+| <Target>          | B | m | I   | TARGET              | <Path-parameter>       | –       | Target file name                                                         |
+| <Error>           | B | m | O   | ERROR               | <Error-parameter>      | –       | The error returned by the CA                                             |
+| <Minor>           | + | o | O   | MINOR               | <Error-parameter>      | –       |                                                                          |
+| <Warning>         | + | o | O   | WARNING             | <Error-parameter>      | –       |                                                                          |
+
+#### 6.6.4 Submit
+
+The submit functionality is designed to enable the CA to perform various utility functions.
+
+The purpose of the submit functionality is to ask the CA to perform additional functions that it may implement, like file format conversions, or printing incoming documents. These tasks are normally not accomplished by the CA but some CA manufacturers may wish to support them. An example of a situation where the "printing" feature may be useful could be the situation of a "CA server" on a LAN. The submit functionality supports the following TDDs:
+
+- <PrintTDD> to PRINT a document, given its path and format;
+- <ConvertTDD> to CONVERT a document, given its path, input format, output format and output filename;
+- <CheckTDD> to CHECK the Transfer Format of a document, given its path and the Transfer Format against which it should be checked.
+
+##### 6.6.4.1 Submit: PRINT
+
+See Table 30.
+
+TABLE 30/T.611
+
+###### Syntax elements of the <PrintTDD>
+
+| Syntax Element  | C | T | I/O | Text Based Encoding |                        |         | Comment                                                                                                                                                                                                  |
+|-----------------|---|---|-----|---------------------|------------------------|---------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+|                 |   |   |     | Keyword             | Parameter              | Default |                                                                                                                                                                                                          |
+| <PrintFunction> | B | m | I   | FUNCTION            | "Print"                | –       | Submit the printing task to the CA                                                                                                                                                                       |
+| <Lald>          | B | m | I   | LA-ID               | <La-id-parameter>      | –       |                                                                                                                                                                                                          |
+| <ReqId>         | B | m | I   | REQ-ID              | <Req-id-parameter>     | –       |                                                                                                                                                                                                          |
+| <FileName>      | B | m | I   | FILENAME            | <Path-parameter>       | –       | Original file                                                                                                                                                                                            |
+| <InFormat>      | B | m | I   | INFORMAT            | <Convert-id-parameter> | –       | Original format                                                                                                                                                                                          |
+| <Error>         | B | m | O   | ERROR               | <Error-parameter>      | –       | The error returned by the CA                                                                                                                                                                             |
+| <Printer>       | + | o | I   | PRINTER             | <Printer-id-parameter> | "STD"   | "STD" stands for the standard printer configured inside of the CA. Further possible values for the values of the Printer-id are declared on a per CA basis in the "PRINT" component of the ICE (see 9.5) |
+| <Minor>         | + | o | O   | MINOR               | <Error-parameter>      | –       |                                                                                                                                                                                                          |
+| <Warning>       | + | o | O   | WARNING             | <Error-parameter>      | –       |                                                                                                                                                                                                          |
+
+##### 6.6.4.2 Submit: CONVERT
+
+See Table 31.
+
+TABLE 31/T.611  
+Syntax elements of the <ConvertTDD>
+
+| Syntax Element    | C | T | I/O | Text Based Encoding |                        |         | Comment                              |
+|-------------------|---|---|-----|---------------------|------------------------|---------|--------------------------------------|
+|                   |   |   |     | Keyword             | Parameter              | Default |                                      |
+| <ConvertFunction> | B | m | I   | FUNCTION            | "Convert"              | –       | Submit the converting task to the CA |
+| <LaId>            | B | m | I   | LA-ID               | <La-id-parameter>      | –       |                                      |
+| <ReqId>           | B | m | I   | REQ-ID              | <Req-id-parameter>     | –       |                                      |
+| <FileName>        | B | m | I   | FILENAME            | <Path-parameter>       | –       | Original file                        |
+| <Target>          | B | m | I   | TARGET              | <Path-parameter>       | –       | Target file                          |
+| <InFormat>        | B | m | I   | INFORMAT            | <Convert-id-parameter> | –       | Original format                      |
+| <OutFormat>       | B | m | I   | OUTFORMAT           | <Convert-id-parameter> | –       | Target format                        |
+| <Error>           | B | m | O   | ERROR               | <Error-parameter>      | –       | The error returned by the CA         |
+| <Minor>           | + | o | O   | MINOR               | <Error-parameter>      | –       |                                      |
+| <Warning>         | + | o | O   | WARNING             | <Error-parameter>      | –       |                                      |
+
+##### 6.6.4.3 Submit: CHECK
+
+See Table 32.
+
+TABLE 32/T.611  
+Syntax elements of the <CheckTDD>
+
+| Syntax Element   | C | T | I/O | Text Based Encoding |                    |         | Comment                            |
+|------------------|---|---|-----|---------------------|--------------------|---------|------------------------------------|
+|                  |   |   |     | Keyword             | Parameter          | Default |                                    |
+| <DeleteFunction> | B | m | I   | FUNCTION            | "Check"            | –       | Submit the checking task to the CA |
+| <LaId>           | B | m | I   | LA-ID               | <La-id-parameter>  | –       |                                    |
+| <ReqId>          | B | m | I   | REQ-ID              | <Req-id-parameter> | –       |                                    |
+
+TABLE 32/T.611 (*end*)
+
+###### **Syntax elements of the <CheckTDD>**
+
+| Syntax Element | C | T | I/O | Text Based Encoding |                        |         | Comment                      |
+|----------------|---|---|-----|---------------------|------------------------|---------|------------------------------|
+|                |   |   |     | Keyword             | Parameter              | Default |                              |
+| <FileName>     | B | m | I   | FILENAME            | <Path-parameter>       | –       | Original file                |
+| <Check>        | B | m | I   | CHECK               | <Convert-id-parameter> | –       | Format to be checked against |
+| <Error>        | B | m | O   | ERROR               | <Error-parameter>      | –       | The error returned by the CA |
+| <Minor>        | + | o | O   | MINOR               | <Error-parameter>      | –       |                              |
+| <Warning>      | + | o | O   | WARNING             | <Error-parameter>      | –       |                              |
+
+#### **6.6.5 Extend**
+
+The extend functionality is divided into of three different TDD types. These are:
+
+- <ExtendTDD> to EXTEND the functionality on a general basis;
+- <NationalTDD> to extend the functionality on a NATIONAL basis;
+- <PrivateTDD> to extend the functionality on a PRIVATE basis.
+
+##### **6.6.5.1 Extend: EXTEND**
+
+The <ExtendTDD> is designed to provide extended features that are not vital for the functioning of the interface, but use of which becomes widespread or necessary. The <ExtendTDD> is an additional facility (see Table 33).
+
+TABLE 33/T.611
+
+###### **Minimum syntax elements of the <ExtendTDD>**
+
+| Syntax Element   | C | T | I/O | Text Based Encoding |                         |         | Comment                                                                           |
+|------------------|---|---|-----|---------------------|-------------------------|---------|-----------------------------------------------------------------------------------|
+|                  |   |   |     | Keyword             | Parameter               | Default |                                                                                   |
+| <ExtendFunction> | B | m | I   | FUNCTION            | "Extend"                | –       |                                                                                   |
+| <SubFunction>    | B | m | I   | SUBFUNC             | <Subfunction-parameter> | –       | For assignment of values see appropriate clause of Part II of this Recommendation |
+| <Lald>           | B | m | I   | LA-ID               | <La-id-parameter>       | –       |                                                                                   |
+| <ReqId>          | B | m | I   | REQ-ID              | <Req-id-parameter>      | –       |                                                                                   |
+| <Error>          | B | m | O   | ERROR               | <Error-parameter>       | –       | The error returned by the CA                                                      |
+
+##### 6.6.5.2 Extend: NATIONAL
+
+The <NationalTDD> is designed to provide national features that are specific to each country. The <NationalTDD> is an additional facility (see Table 34).
+
+TABLE 34/T.611
+
+**Minimum syntax elements of the <NationalTDD>**
+
+| Syntax Element     | C | T | I/O | Text Based Encoding |                             |         | Comment                                |
+|--------------------|---|---|-----|---------------------|-----------------------------|---------|----------------------------------------|
+|                    |   |   |     | Keyword             | Parameter                   | Default |                                        |
+| <NationalFunction> | B | m | I   | FUNCTION            | "National"                  | –       |                                        |
+| <SubFunction>      | B | m | I   | SUBFUNC             | <Subfunction<br>-parameter> | –       | Parameter values are for further study |
+| <Lald>             | B | m | I   | LA-ID               | <La-id-<br>parameter>       | –       |                                        |
+| <ReqId>            | B | m | I   | REQ-ID              | <Req-id-<br>parameter>      | –       |                                        |
+| <Error>            | B | m | O   | ERROR               | <Error-<br>parameter>       | –       | The error returned by the CA           |
+
+##### 6.6.5.3 Extend: PRIVATE
+
+The <PrivateTDD> is designed to provide private features that are specific to each manufacturer. The <PrivateTDD> is an additional facility (see Table 35).
+
+TABLE 35/T.611
+
+**Minimum syntax elements of the <PrivateTDD>**
+
+| Syntax Element    | C | T | I/O | Text Based Encoding |                             |         | Comment                                |
+|-------------------|---|---|-----|---------------------|-----------------------------|---------|----------------------------------------|
+|                   |   |   |     | Keyword             | Parameter                   | Default |                                        |
+| <PrivateFunction> | B | m | I   | FUNCTION            | "Private"                   | –       |                                        |
+| <SubFunction>     | B | m | I   | SUBFUNC             | <Subfunction<br>-parameter> | –       | Parameter values are for further study |
+| <Lald>            | B | m | I   | LA-ID               | <La-id-<br>parameter>       | –       |                                        |
+| <ReqId>           | B | m | I   | REQ-ID              | <Req-id-<br>parameter>      | –       |                                        |
+| <Error>           | B | m | O   | ERROR               | <Error-<br>parameter>       | –       | The error returned by the CA           |
+
+## 7 Exchange Method
+
+This clause describes how TDDs and related data are transferred between LAs and CAs.
+
+To transfer the TDDs and associated data, this Recommendation defines an abstract Exchange Method between LAs and CAs. This Exchange Method can be realized by different means, which are more or less platform dependent.
+
+To aid LA developers in writing portable code, the platform dependencies have been encapsulated on a functional level which consists of the Basic Exchange Method Functions (BEM Functions).
+
+Figure 9 depicts this situation.
+
+![Diagram illustrating the Usage of the Basic Exchange Method Functions. It shows a Local Application (LA) box containing LA main code, Basic Exchange Method Functions, File Exchange Method adaption, and Primitive Exchange Method adaption. Below the LA box is a double-headed arrow labeled T.611 Interface, and below that is a Communication Application (CA) box. The entire diagram is labeled T0823400-95/d07.](68a5a1a1a761c652b4b4c56da7cf9914_img.jpg)
+
+The diagram illustrates the architecture for the exchange of TDDs and data between a Local Application (LA) and a Communication Application (CA). The LA is represented by a large box containing several components: 'LA main code' at the top, followed by 'Basic Exchange Method Functions', and then two side-by-side boxes for 'File Exchange Method adaption' and 'Primitive Exchange Method adaption'. Below the LA box, a horizontal double-headed arrow labeled 'T.611 Interface' connects to the 'Communication Application (CA)' box at the bottom. The entire diagram is identified by the code 'T0823400-95/d07' in the bottom right corner.
+
+Diagram illustrating the Usage of the Basic Exchange Method Functions. It shows a Local Application (LA) box containing LA main code, Basic Exchange Method Functions, File Exchange Method adaption, and Primitive Exchange Method adaption. Below the LA box is a double-headed arrow labeled T.611 Interface, and below that is a Communication Application (CA) box. The entire diagram is labeled T0823400-95/d07.
+
+FIGURE 9/T.611  
+Usage of the Basic Exchange Method Functions
+
+The BEM Functions present a functional interface, which decouples the code of the LA from the real exchange methods to be used.
+
+The real exchange methods defined for the various platforms are either of type File Exchange Method or Primitive Exchange Method. These two types of exchange method are fully detailed in 7.3.
+
+NOTE – Since it is only required that the binary exchange of TDDs and associated data conforms to this Recommendation, the use of the BEM Functions within the code of the LA is optional. The only requirement the LA shall meet is the conformance to the real exchange method defined for each platform. Thus a LA implementor may decide to interface directly to one of the real exchange methods defined.
+
+### 7.1 Overview of Basic Exchange Method Functions
+
+NOTE – The Basic Exchange Method Functions described in this subclause supersede the method documented in the 1992 version of this Recommendation. For details of the differences refer to Annex F where the previous version of the Basic Exchange Method Functions has been included for convenience.
+
+Different implementations of the Basic Exchange Method are possible. All have in common the Basic Exchange Method Functions shown in Table 36<sup>5)</sup>.
+
+<sup>5)</sup> In order to differentiate the set of BEM Functions defined in this Recommendation from the set defined in the 1992 version of this Recommendation, the names of the BEM Functions are starting with an uppercase letter "E".
+
+TABLE 36/T.611
+
+#### **Summary of Exchange Method Functions**
+
+| BEM Function                                                                                                                                                                                                                                          | Purpose                                                                       |
+|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------|
+| ELogin                                                                                                                                                                                                                                                | LA opens a communication channel between LA and CA                            |
+| ELogout                                                                                                                                                                                                                                               | LA closes the communication channel opened with ELogin ( )                    |
+| EPutTDD                                                                                                                                                                                                                                               | LA hands over a TDD to a CA                                                   |
+| EPutData                                                                                                                                                                                                                                              | LA hands over data referring to a specific TDD                                |
+| EPollTDD                                                                                                                                                                                                                                              | LA asks CA whether a Response TDD is available                                |
+| EGetTDD                                                                                                                                                                                                                                               | LA gets a Response TDD from the CA                                            |
+| EGetData                                                                                                                                                                                                                                              | LA gets data referring to a specific TDD                                      |
+| ESetAlarm                                                                                                                                                                                                                                             | LA sets an alarm inside of the CA. CA then will wake up LA on specific events |
+| EAbortData                                                                                                                                                                                                                                            | LA aborts transfer of data                                                    |
+| NOTE – The Basic Exchange Method has been designed to work with many configurations, such as LA and CA being on the same equipment or CA being a communication server on a LAN. The only assumption is that the ICE shall be accessible from each LA. |                                                                               |
+
+In general, the Basic Exchange Method Functions rely on a login procedure (ELogin) which returns a Connection-ID. This Connection-ID is then used in all subsequent invocations of the Basic Exchange Method functions. The login procedure is comparable to opening an interaction channel between a LA and a CA.
+
+#### 7.1.1 Sequence of Basic Exchange Method Functions
+
+Firstly, a LA needs to login (function ELogin) to the requested CA. No TDD exchange can take place before the login procedure is completed. By nature, the login procedure is a synchronous mechanism, i.e. the login requires a response before another action can take place.
+
+When a LA wishes to send a Request TDD to a CA, it shall carry out the following steps:
+
+- build the Request TDD (by any appropriate means);
+- invoke the EPutTDD function;
+- invoke the EPutData function, if associated data have to be transferred.
+
+When a LA needs to be informed of possible events bound for it, the LA shall:
+
+- invoke the EPollTDD function.
+
+When a LA needs to retrieve a Response TDD (the EPollTDD function above indicated available Response TDDs), the LA shall:
+
+- invoke the EGetTDD function;
+- invoke the EGetData function, if associated data have to be retrieved.
+
+When a LA receives an alarm from the CA – applicable only if the CA supports alarms as stated in the ICE (see clause 9) and if the LA implements the alarm invocation function –, it shall:
+
+- invoke the EPolITDD function;
+- invoke the EGetTDD function;
+- invoke the EGetData function, if associated data have to be retrieved.
+
+When a LA no longer needs to dialogue with a CA, it shall logout (function ELogout) from this CA. The CA thus knows the LA-CA communications path is broken and thus will not use the alarm mechanism any longer.
+
+The EPutTDD, EPolITDD, EGetTDD, ESetAlarm, ECallBackRoutine, ELogin and ELogout functions are synchronous, i.e. the LA can proceed only when those functions have returned. The functions and their calling and return parameters are shown in 7.2.
+
+Figure 10 illustrates the behaviour described above.
+
+![Sequence diagram showing the interaction between LA and CA for alarm support. The diagram includes a vertical 'Time' axis on the left. LA sends a 'Request TDD' box to CA via a solid line labeled 'EPutTDD'. CA performs a task (dashed oval). CA sends 'EPolITDD' (dashed line) and 'Alarm (Signal)' (dashed line) to LA. LA sends 'EPolITDD' (solid line) and 'EGetTDD' (solid line) to CA. CA sends a 'Response TDD' box to LA via a solid line. A legend at the bottom indicates solid lines for mandatory function calls and dashed lines for optional function calls. The reference 'T0823410-95/d08' is at the bottom right.](4cd9eeaee1deb05bf88a8abf02ff7d7f_img.jpg)
+
+```
+
+sequenceDiagram
+    participant LA
+    participant CA
+    Note left of LA: Request TDD
+    LA->>CA: EPutTDD
+    Note right of CA: CA performs its task
+    CA-->>LA: EPolITDD
+    CA-->>LA: Alarm (Signal)
+    LA->>CA: EPolITDD
+    LA->>CA: EGetTDD
+    Note right of CA: Response TDD
+    CA-->>LA: 
+    
+```
+
+T0823410-95/d08
+
+—————> Mandatory function call  
+ - - - - -> Optional function call
+
+Sequence diagram showing the interaction between LA and CA for alarm support. The diagram includes a vertical 'Time' axis on the left. LA sends a 'Request TDD' box to CA via a solid line labeled 'EPutTDD'. CA performs a task (dashed oval). CA sends 'EPolITDD' (dashed line) and 'Alarm (Signal)' (dashed line) to LA. LA sends 'EPolITDD' (solid line) and 'EGetTDD' (solid line) to CA. CA sends a 'Response TDD' box to LA via a solid line. A legend at the bottom indicates solid lines for mandatory function calls and dashed lines for optional function calls. The reference 'T0823410-95/d08' is at the bottom right.
+
+FIGURE 10/T.611
+
+##### Sample sequence of Basic Exchange Method Functions
+
+It is assumed that the LA has already logged into the CA. Data transfer functions are not shown.
+
+#### 7.1.2 Alarm Support
+
+If the CA implements the optional alarm feature, it means that the CA implements the ESetAlarm function. This function allows a CA to wake up a given LA on specific alarm events.
+
+Support of the alarm feature shall be stated in the ICE (see clause 9).
+
+#### 7.1.3 Connection-ID
+
+In order to identify a LA-CA communications path, the Connection-ID is defined. The Connection-ID is computed by the CA on invocation of the Login request. The LA shall use this identifier throughout the interchange with the same CA until the LA logs out.
+
+NOTE – The Connection-ID is different from the COM-ID; the COM-ID identifies communication events occurring in a CA.
+
+#### 7.1.4 CA-ID
+
+The CA-ID identifies a CA. This identifier allows a LA to have simultaneous interactions with multiple LAs. Therefore the CA-ID is a parameter used in each EM function call.
+
+### 7.2 Basic Exchange Method Functions
+
+The functions described below replace or supplement the functions of the basic exchange mechanism of the 1992 version of this Recommendation (see also Annex F). For differentiation purposes, the names of the functions defined within this Recommendation start with the uppercase letter "E".
+
+All functions perform synchronously, i.e the caller cannot continue execution until the called function returns.
+
+Since the implementation of the BEM Functions is platform dependent, they are described in a generic way in the subclauses to follow. The implementation of the functions for the various platforms is described in Part IV of this Recommendation.
+
+NOTE – The order the parameters are appearing in the following description of the BEM Functions is important for compatibility.
+
+The data types used for the generic description of the BEM Functions are defined in Table 37. They are mapped to real data types in the appropriate clauses of Part IV of this Recommendation.
+
+The Direction classification "Input" stands for "parameter shall be presented on function call", "Output" stands for "parameter valid on return of function".
+
+TABLE 37/T.611
+
+**Data types used for description of BEM Functions**
+
+| Data type      | Explanation                                                              |
+|----------------|--------------------------------------------------------------------------|
+| String         | Stands for a string of characters                                        |
+| Integer        | Stands for a number in the minimum range of $+2^{15} \dots (2^{15} - 1)$ |
+| Boolean        | Stands for a variable taking the value true or false                     |
+| Memory address | Stands for an address inside of LA's memory                              |
+
+#### 7.2.1 Function ELogin
+
+The function ELogin shall be supported by the CA. It shall be invoked by the LA before any LA-CA interchange of Request TDDs and responses.
+
+##### 7.2.1.1 Purpose
+
+The function ELogin returns to the LA a Connection-ID that will be used all along the LA-CA interaction until the LA logs out.
+
+Furthermore the ELogin function allows to select a CA on user-provided criteria and returns a CA-ID, which shall be used in subsequent BEM function calls to address the selected CA.
+
+Selection of a CA is performed by specifying a string containing keywords like "FAX", "ECM" or "EMAIL", separated by spaces, in the Selector parameter. Since it can be performed by external processes, the selection mechanism is out of the scope of this Recommendation.
+
+If the Selector parameter is specified, then the CA-ID parameter shall not be specified; when the function call returns, either the CA-ID parameter contains a valid CA identifier that can be used in further BEM function calls, or the CA-ID parameter is empty if no CA matched the selection criteria. If the Selector parameter is not specified in the function call, then no selection is to be performed. In this case the CA-ID parameter shall be specified.
+
+The ELogin function is the place where a CA may control access of a LA to it. This can be achieved by checking the Login-name and the Password given by the LA. However, the extent to which control of the access rights is performed, is up to the CA implementation.
+
+##### 7.2.1.2 Behaviour
+
+The CA checks the parameters of the ELogin call. If they match, it then generates a Connection-ID the LA shall use subsequently in other BEM Function calls. In addition, if the Selector parameter specifies criteria, the function returns the CA-ID of a CA that match the criteria. If the Connection-ID returned is set to zero, it means the CA failed to connect with the LA.
+
+##### 7.2.1.3 Parameters
+
+See Table 38.
+
+TABLE 38/T.611
+
+**Parameters of the ELogin function**
+
+| Parameter     | Data type | Comment                                                                                                                                                                                                                                             | Direction |
+|---------------|-----------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------|
+| Login-name    | String    | Name of the LA user connecting to the CA (differs from the LA-ID)                                                                                                                                                                                   | Input     |
+| Password      | String    | A password string                                                                                                                                                                                                                                   | Input     |
+| Selector      | String    | A user-provided string specifying connection criteria                                                                                                                                                                                               | Input     |
+| CA-ID         | Integer   | Identifier of the CA that accepts the connection                                                                                                                                                                                                    | Output    |
+| Connection-ID | Integer   | Identifier (handle) of the LA-CA data channel. Returned by the CA if the ELogin function succeeds. Otherwise (e.g. identification failed) the CA sets the value to zero and an appropriate return code is given by the Status parameter (see below) | Output    |
+| Status        | Integer   | Return code; a value of zero indicates successful operation                                                                                                                                                                                         | Output    |
+
+#### 7.2.2 Function EPutTDD
+
+The function EPutTDD shall be supported by the CA. It may be invoked by a LA. The EPutTDD also supports the identification of the data files to be transferred to the CA.
+
+Such data files are typically address-list files or documents or both.
+
+##### 7.2.2.1 Purpose
+
+The EPutTDD function conveys a Request TDD to the CA and allows the LA to specify which files need to be transferred to the CA. The actual transfer of data files to the CA is performed with the EPutData function.
+
+##### 7.2.2.2 Behaviour
+
+The CA copies the Request TDD carried by the EPutTDD function into its internal structures. The result is reported immediately to the requesting LA. If the LA requests a Data-ID by specifying a Data-ID address, CA returns the identifier of a data group as Data-ID.
+
+If this identifier is NULL, then no data files (or buffers) are to be transmitted to the CA. If the Data-ID is not NULL, then the LA performs the subsequent data file transfers with EPutData function. The transfers shall occur immediately after the call to EPutTDD function.
+
+NOTE – The Data-ID returned may be valid for a limited time only.
+
+##### 7.2.2.3 Parameters
+
+See Table 39.
+
+TABLE 39/T.611
+
+**Parameters of the EPutTDD function**
+
+| Parameter     | Data type      | Comment                                                                                                                                  | Direction    |
+|---------------|----------------|------------------------------------------------------------------------------------------------------------------------------------------|--------------|
+| Connection-ID | Integer        | Identifier (handle) of the LA-CA data channel returned by the ELogin function                                                            | Input        |
+| CA-ID         | Integer        | Identifier of the CA as returned by the ELogin function                                                                                  | Input        |
+| TDD-location  | Memory address | Memory location of the TDD to be passed to the CA. After return from the function the LA's TDD may be deleted or used for other purposes | Input        |
+| TDD-size      | Integer        | Size in octets of the TDD passed to the CA                                                                                               | Input        |
+| Data-ID       | Integer        | Identifier of the data group, returned by the CA if requested                                                                            | Input/Output |
+| Status        | Integer        | Return code; a value of zero indicates successful operation                                                                              | Output       |
+
+#### 7.2.3 Function EPutData
+
+This function allows the actual transfer of data (address lists and/or data files) from the LA to the CA. Depending on the implementation the data can either be files or buffers.
+
+##### 7.2.3.1 Purpose
+
+The group of files transferred within one function call relates to one previous Request TDD that was transmitted to the CA by means of a previous EPutTDD function call.
+
+The group is identified by the Data-ID that the CA returned as a result of the previous EPutTDD function call.
+
+##### 7.2.3.2 Behaviour
+
+This function is invoked by the LA after the corresponding Request TDD was transmitted to the CA.
+
+The LA shall build a data structure (Data-Descriptor) that describes where the files/buffers to be conveyed to the CA are located. The specification of the data structure is language-dependent but cross platform compatibility ensures that the binary layout does not depend on the platforms or languages.
+
+The LA may transfer all the data in one shot or in multiple calls. The parameter Next indicates whether the function call is the last in the data group or that more function calls relevant to that data group are to follow.
+
+##### 7.2.3.3 Parameters
+
+See Table 40.
+
+TABLE 40/T.611
+
+**Parameters of the EPutData function**
+
+| Parameter       | Data type      | Comment                                                                                                                                                      | Direction |
+|-----------------|----------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------|
+| Connection-ID   | Integer        | Identifier (handle) of the LA-CA data channel                                                                                                                | Input     |
+| CA-ID           | Integer        | Identifier of the CA                                                                                                                                         | Input     |
+| Data-ID         | Integer        | Identifier of the data group, returned by the CA                                                                                                             | Input     |
+| Data-Descriptor | Memory address | Memory address of a data structure specifying which files/buffers have to be conveyed to the CA                                                              | Input     |
+| Next            | Boolean        | Indicator stating whether more data will be conveyed in a subsequent call to the function EPutData or that no more data is to follow (end of the data group) | Input     |
+| Status          | Integer        | Return code; a value of zero indicates successful operation                                                                                                  | Output    |
+
+#### 7.2.4 Function EPollTDD
+
+The EPollTDD function asks the CA how many Response TDDs are waiting to be handled by the requesting LA. The EPollTDD returns the number of Response TDDs pending and the type and size of the first Response TDD that will be returned by the next call to the EGetTDD function.
+
+The EPollTDD function furthermore allows to select the type of TDD that is to be returned by the CA.
+
+##### 7.2.4.1 Purpose
+
+The EPollTDD function allows to poll the CA in order to know how many Response TDDs are pending for retrieval.
+
+##### 7.2.4.2 Behaviour
+
+The function allows the LA to select the type of Response TDD to be polled by giving a specific TDD-type parameter. If the LA specifies no TDD-type (TDD-type set to zero), the function selects, if available, any type of TDD and returns the selected type. The TDD selected, if any, then may be retrieved by a subsequent EGetTDD function call.
+
+The EPollTDD function also returns the size of the Response TDD that will be returned, if any. The CA then should allocate enough storage space to receive the Response TDD returned by the next call to EGetTDD. The size given by the CA is an indication of the minimum buffer size that will hold the Response TDD.
+
+Furthermore, the amount of pending Response TDDs – of the selected type – is returned. If the count returned is zero, no Response TDDs – of the selected type – are pending.
+
+When the CA has many Response TDDs available, it chooses the one it will return first. This Response TDD is the TDD that will be transmitted to the LA at the next EGetTDD function call emitted by the same LA.
+
+When no Response TDD is available for the requesting LA, the TDD-count is set to the value zero, in which case the TDD size returned is set to zero as well.
+
+If the TDD that was submitted is erroneous or unknown, e.g. the <TDD Header> is missing, then the function may return the original Request TDD. In this case the CA shall set the returned TDD-type to zero and the return status to a non-zero value.
+
+The TDD-type values assigned are shown by Table 41.
+
+TABLE 41/T.611
+
+##### Assignment of TDD-types
+
+| Response TDD                                                                                                                                                                                | TDD-type          | Response TDD      | TDD-type          |
+|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------|-------------------|-------------------|
+| No TDD-type <sup>a)</sup>                                                                                                                                                                   | 00 <sub>HEX</sub> | DISPATCH Response | 35 <sub>HEX</sub> |
+| SENDACK Response                                                                                                                                                                            | 10 <sub>HEX</sub> | PREVIEW Response  | 36 <sub>HEX</sub> |
+| RECEIVE Response                                                                                                                                                                            | 20 <sub>HEX</sub> | PRINT Response    | 40 <sub>HEX</sub> |
+| COPY Response                                                                                                                                                                               | 30 <sub>HEX</sub> | CONVERT Response  | 41 <sub>HEX</sub> |
+| DELETE Response                                                                                                                                                                             | 31 <sub>HEX</sub> | CHECK Response    | 42 <sub>HEX</sub> |
+| CANCEL Response                                                                                                                                                                             | 32 <sub>HEX</sub> | EXTEND Response   | 50 <sub>HEX</sub> |
+| PURGE Response                                                                                                                                                                              | 33 <sub>HEX</sub> | NATIONAL Response | 60 <sub>HEX</sub> |
+| RESCHEDULE Response                                                                                                                                                                         | 34 <sub>HEX</sub> | PRIVATE Response  | 70 <sub>HEX</sub> |
+| <sup>a)</sup> Used as selector (on input) 00 <sub>HEX</sub> stands for "all TDD-types"; as return value it stands for unknown or erroneous TDD was submitted, or no Response TDD available. |                   |                   |                   |
+
+##### 7.2.4.3 Parameters
+
+See Table 42.
+
+TABLE 42/T.611
+
+**Parameters of the EPollTDD function**
+
+| Parameter     | Data type | Comment                                                                       | Direction    |
+|---------------|-----------|-------------------------------------------------------------------------------|--------------|
+| Connection-ID | Integer   | Identifier (handle) of the LA-CA data channel returned by the ELogin function | Input        |
+| CA-ID         | Integer   | Identifier of the CA                                                          | Input        |
+| TDD-type      | Integer   | Selects/returns the type of Response TDD expected/available                   | Input/Output |
+| TDD-size      | Integer   | Size of the next Response TDD ready to be retrieved                           | Output       |
+| TDD-count     | Integer   | Count of Response TDDs pending. Zero indicates: no response pending           | Output       |
+| Status        | Integer   | Return code; a value of zero indicates successful operation                   | Output       |
+
+#### 7.2.5 Function EGetTDD
+
+The function EGetTDD shall be supported by the CA. It may be invoked by a LA. EGetTDD allows to retrieve a Response TDD and get a data group identifier to retrieve the accompanying data files/buffers.
+
+##### 7.2.5.1 Purpose
+
+EGetTDD allows the LA to retrieve a Response TDD into memory and obtain a handle to a group of data files/buffers. The handle is useful for all TDD types that involve data files/buffers, e.g. Receive or Trace:COPY.
+
+##### 7.2.5.2 Behaviour
+
+The LA specifies the memory address where the CA shall copy a Response TDD that is available for the LA.
+
+The CA shall return to the LA the Response TDD that was qualified by the previous EPollTDD function emitted by the same LA. The LA shall have prepared a recipient Response TDD area in its internal structures. The invocation of a EGetTDD function by a LA shall always be preceded by a EPollTDD function call. On call, the LA shall pre-set the TDD size parameter to the size of its response area. On return, the TDD size parameter shall hold the size of the Response TDD the CA provided.
+
+If the LA invokes two or more consecutive EGetTDD functions (without an intermediate EPollTDD function call) the CA may return invalid information.
+
+The EGetTDD function also returns the Data-ID identifier as a handle to receive the accompanying data files (with a subsequent EGetData function call).
+
+If the Data-ID parameter value is not zero, then data files need to be retrieved by a subsequent call to the EGetData function. If the Data-ID parameter is zero, then no additional data is to be retrieved from the CA.
+
+##### 7.2.5.3 Parameters
+
+See Table 43.
+
+TABLE 43/T.611
+
+**Parameters of the EGetTDD function**
+
+| Parameter     | Data type      | Comment                                                                       | Direction    |
+|---------------|----------------|-------------------------------------------------------------------------------|--------------|
+| Connection-ID | Integer        | Identifier (handle) of the LA-CA data channel returned by the ELogin function | Input        |
+| CA-ID         | Integer        | Identifier of the CA                                                          | Input        |
+| TDD-location  | Memory address | Specifies the location where the Response TDD shall be stored                 | Input        |
+| TDD-size      | Integer        | Size of the buffer reserved for storing the Response TDD                      | Input/Output |
+| Data-ID       | Integer        | Identifier of the data group, if any                                          | Output       |
+| Status        | Integer        | Return code; a value of zero indicates successful operation                   | Output       |
+
+#### 7.2.6 Function EGetData
+
+This function allows the transfer of data files (or buffers) from the CA to the LA. It is called by the LA.
+
+##### 7.2.6.1 Purpose
+
+This function is used to retrieve the data from the CA after receiving a Response TDD (with the EGetTDD function) that specifies that data is to be retrieved (parameter Data-ID is not zero).
+
+##### 7.2.6.2 Behaviour
+
+Immediately after the EGetTDD, the LA shall call the EGetData in order to receive the corresponding data (files or buffers). The CA returns a data descriptor containing information about the received data. The CA also returns whether additional calls to EGetTDD should be performed by the LA to retrieve further pertaining data.
+
+The group of files transferred within one function call relates to one Response TDD (through a EGetTDD function call). This group is identified by the Data-ID parameter (LA provided).
+
+##### 7.2.6.3 Parameters
+
+See Table 44.
+
+TABLE 44/T.611
+
+**Parameters of the EGetData function**
+
+| Parameter       | Data type      | Comment                                                                                                                | Direction    |
+|-----------------|----------------|------------------------------------------------------------------------------------------------------------------------|--------------|
+| Connection-ID   | Integer        | Identifier (handle) of the LA-CA data channel returned by the ELogin function                                          | Input        |
+| CA-ID           | Integer        | Identifier of the CA                                                                                                   | Input        |
+| Data-ID         | Integer        | Identifier of the data group                                                                                           | Input        |
+| Data-Descriptor | Memory address | Storage address of a descriptor for the data to be retrieved, passed to the CA on input and filled by the CA on output | Input/Output |
+| Next            | Boolean        | States whether additional data should be retrieved                                                                     | Output       |
+| Status          | Integer        | Return code; a value of zero indicates successful operation                                                            | Output       |
+
+#### 7.2.7 Function ESetAlarm
+
+The function ESetAlarm can optionally be supported by the CA. In this case, it can optionally be invoked by a LA. If the ESetAlarm function is used by a LA, that LA shall supply an AlarmHandler. An AlarmHandler is a function which receives the subsequent alarms generated by the CA.
+
+A CA shall declare the support of the ESetAlarm function in the ICE.
+
+##### 7.2.7.1 Purpose
+
+This function allows the LA to register to the connected CA the type of alarm events the LA supports. This function shall not be invoked if the CA does not understand the alarm mechanism. Whether a CA understands the alarm mechanism may be obtained from the ALARM element of the ICE (see clause 9).
+
+The ESetAlarm function tells the CA that it can give an alarm to the LA by invoking the AlarmHandler supplied.
+
+The LA may temporarily disable an alarm event by disabling the corresponding address of the AlarmHandler, e.g. by setting the address to NULL. Restoring the alarm event for that alarm type is performed by enabling the address of the AlarmHandler, e.g. by setting the address to the actual entry point of the AlarmHandler.
+
+The alarm events defined are shown in Table 45.
+
+##### 7.2.7.2 Behaviour
+
+The CA supporting the ESetAlarm function shall record the location of the AlarmHandler function assigned by the LA. In the minimum, the CA can record as many AlarmHandler locations as there are different logged-in LAs. If an event registered to a particular LA occurs, the CA shall send the alarm to the particular LA by invoking its AlarmHandler.
+
+TABLE 45/T.611
+
+##### **Alarm events for the ESetAlarm function**
+
+| Event name                                                                            | Comment                                                                                        |
+|---------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------|
+| ASYNC_RESPONSES                                                                       | The LA will not poll the CA. The CA should send an alarm each time a Response TDD is available |
+| QUEUE_FULL                                                                            | The CA will not accept any further TDDs unless the CA is polled                                |
+| DOCUMENT_RECEIVED                                                                     | A new document can be received                                                                 |
+| CONNECTION_LOST                                                                       | The LA-CA connection is lost                                                                   |
+| SEND_SUCCESS                                                                          | A document was successfully sent                                                               |
+| SEND_FAILED                                                                           | A document failed to be sent                                                                   |
+| CORRUPTED_TDD                                                                         | The CA received a corrupted/unrecognizable TDD                                                 |
+| SEND_EVENT                                                                            | A send event occurred in the CA                                                                |
+| RECEIVE_EVENT                                                                         | A receive event occurred in the CA                                                             |
+| CA_WILL_STOP                                                                          | The CA will no longer process requests. Logout immediately                                     |
+| ALARMS_UNAVAILABLE                                                                    | Alarms are no longer available                                                                 |
+| TDD_RESP_AVAILABLE                                                                    | A TDD response is available. The LA should poll the CA as soon as possible                     |
+| NOTE – Some alarms need additional data to give accurate information about the event. |                                                                                                |
+
+##### **7.2.7.3 Parameters**
+
+See Table 46.
+
+TABLE 46/T.611
+
+##### **Parameters of the ESetAlarm function**
+
+| Parameter     | Data type      | Comment                                                                                                                                                                                                                        | Direction |
+|---------------|----------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------|
+| Connection-ID | Integer        | Identifier (handle) of the LA-CA data channel returned by the ELogin function                                                                                                                                                  | Input     |
+| CA-ID         | Integer        | Identifier of the CA                                                                                                                                                                                                           | Input     |
+| Alarm-event   | Integer        | Combination of the types of alarms the LA may react to                                                                                                                                                                         | Input     |
+| AlarmHandler  | Memory address | Information addressing the entry point of the AlarmHandler. This entry point shall be called by the CA when one of the registered events occurs<br><br>This parameter as well as the AlarmHandler itself is platform-dependent | Input     |
+| Status        | Integer        | Return code; a value of zero indicates successful operation                                                                                                                                                                    | Output    |
+
+##### **7.2.7.4 AlarmHandler Function**
+
+Depending on the platform, the alarm triggered may have parameters that detail the reason for the alarm.
+
+The AlarmHandler function defines a mechanism that allows a CA to alert the LA that some Response TDDs are available. The use of this optional mechanism can improve the flow control between LAs and CAs on heavily loaded systems.
+
+The AlarmHandler is implemented by the LA. The CA calls that function when it needs to trigger an alarm. The alarms the CA may trigger are specified by the LA by means of the ESetAlarm function.
+
+Some alarms may have parameters. They are passed to the LA along with the function call.
+
+Some alarms imply that the LA polls the CA after having received the alarm (e.g. when the CA has received a new document). If the CA does not poll the CA quickly enough, the CA may trigger the alarm repeatedly until the LA performs the expected action.
+
+Since the AlarmHandler function is platform dependent, it is described in greater detail in the appropriate clauses of Part IV of this Recommendation.
+
+#### **7.2.8 Function EAbortData**
+
+The EAbortData function allows to cancel the ongoing transfer of data. It has the effect of canceling the corresponding TDD too.
+
+##### **7.2.8.1 Purpose**
+
+This function is invoked by the LA in order to cancel a data transfer started by EPutData or EGetData.
+
+##### **7.2.8.2 Behaviour**
+
+When aborting an EPutData data transfer, the CA shall destroy the corresponding Request TDD that was conveyed by the previous EPutTDD function call.
+
+When aborting an EGetData data transfer, the CA shall retain the corresponding Response TDD that was retrieved by the previous EGetTDD function call.
+
+Abortion of the data transfers in either direction may occur only between two EGetData or EPutData function calls respectively.
+
+Since the LA is responsible for the data transfer between the LA and the CA, calling EAbortData after the last data block has no effect (the data transfer is completed anyway). For the same reason, calling EAbortData before the first data block has the effect of cancelling the whole data transfer and the corresponding TDD.
+
+##### **7.2.8.3 Parameters**
+
+See Table 47.
+
+#### **7.2.9 Function ELogout**
+
+The function ELogout shall be supported by the CA. It shall be invoked by the LA on completion of any LA-CA interchange of Request TDDs and responses.
+
+##### **7.2.9.1 Purpose**
+
+The function ELogout returns to the LA a status that states whether the LA-CA interaction has finished orderly.
+
+##### **7.2.9.2 Behaviour**
+
+Before completing the LA-CA dialogue, the CA may (but is not obliged to) process all pending Request TDDs that were issued by that LA.
+
+TABLE 47/T.611
+
+##### **Parameters of the EAbortData function**
+
+| Parameter     | Data type | Comment                                                                       | Direction |
+|---------------|-----------|-------------------------------------------------------------------------------|-----------|
+| Connection-ID | Integer   | Identifier (handle) of the LA-CA data channel returned by the ELogin function | Input     |
+| CA-ID         | Integer   | Identifier of the CA                                                          | Input     |
+| Data-ID       | Integer   | Data group identifier                                                         | Input     |
+| Status        | Integer   | Return code; a value of zero indicates successful operation                   | Output    |
+
+##### **7.2.9.3 Parameters**
+
+See Table 48.
+
+TABLE 48/T.611
+
+##### **Parameters of the ELogout function**
+
+| Parameter     | Data type | Comment                                                                       | Direction |
+|---------------|-----------|-------------------------------------------------------------------------------|-----------|
+| Connection-ID | Integer   | Identifier (handle) of the LA-CA data channel returned by the ELogin function | Input     |
+| CA-ID         | Integer   | Identifier of the CA                                                          | Input     |
+| Status        | Integer   | Return code; a value of zero indicates successful operation                   | Output    |
+
+### **7.3 Implementation of Basic Exchange Method Functions**
+
+The Basic Exchange Method Functions offer a functional interface, which has to be adapted to the underlying platform in a well defined way in order to provide a binary compatible interface.
+
+For this purpose this Recommendation defines two real exchange mechanisms:
+
+- 1) the Primitive Exchange Method; and
+- 2) the File Exchange Method.
+
+The Primitive Exchange Method is fast, but platform dependent; the File Exchange Method is far less platform independent, but slower and lacks the ability to implement all features offered by the Basic Exchange Method Functions.
+
+The platforms may impose the type of exchange method to support. See Part IV of this Recommendation.
+
+#### **7.3.1 Primitive Exchange Method**
+
+The Primitive Exchange Method implementation utilizes function calls. It thus requires from the CA to provide an entry point for each of the Basic Exchange Method Functions. To achieve binary compatibility, the provision of this entry point shall conform to the definitions made by this Recommendation for each platform (see Part IV of this Recommendation).
+
+#### 7.3.2 File Exchange Method
+
+The File Exchange Method implementation requires that TDDs are exchanged via files. For this reason, common file directories have to be agreed upon and shared between the LA and the CA. Therefore, the CA shall declare the complete paths for these directories in the appropriate section of the ICE.
+
+Three file directories or, more abstract, areas have to be configured:
+
+- an input area for TDDs that are transferred from the LA to the CA;
+- an area for Response TDDs;
+- an area for jobs that could not be processed due to syntactical errors or other errors. The CA removes incorrect TDDs from the input area and places them in this area.
+
+These three areas are referred to symbolically as COM\_JOB, COM\_ACK and COM\_ERR respectively.
+
+Because they are implementation-and installation-specific, the complete paths to these areas shall be configurable during installation of the CA.
+
+If a CA has to support multiple LA connections, it is suggested that the CA sets up three "mother"-areas (directories) as described above and creates a sub-area (subdirectory) inside of each "mother"-area for each LA which may be connected. The name of each sub-area may be derived from the LA-ID of the connecting LAs.
+
+Adaptation of the Basic Exchange Method Functions to the File Exchange Method is rather complex, since the Basic Exchange Method Functions have to be emulated by the adapter.
+
+NOTE – A LA implementation may – although not encouraged by this Recommendation – also interface directly to the File Exchange Method without using Basic Exchange Method Functions. The disadvantage of this approach is that portability to other primitive based platforms is more difficult to obtain.
+
+##### 7.3.2.1 TDD Transfer
+
+To issue a function request, the LA places a TDD as a file into the COM\_JOB area.
+
+Some implementations, mainly on single tasking platforms, also require that the LA executes a SYNC program. SYNC stands for synchronization. The SYNC program ensures that the CA receives control and can process TDDs. Whether there is a need for executing a SYNC is stated in the CA-Descriptor of the corresponding CA.
+
+When the CA has finished processing the TDD, it places the Response-TDD in the COM\_ACK response area and deletes the Request-TDD in the COM\_JOB input area. The Response-TDD placed by the CA has the same name as the former Request-TDD.
+
+The complete cycle of the job transfer is shown in Figure 11.
+
+NOTE – It is not guaranteed that Response-TDDs will be provided in the same sequence as Request-TDDs. Processing is not necessarily sequential.
+
+##### 7.3.2.2 Error Handling
+
+Request-TDDs not processable by the CA (due to syntactical errors, etc.) are copied to the COM\_ERR area and deleted from the COM\_JOB area. The keyword FATAL is inserted at the end of the Response TDD and an error message with the form [Num/Text] is generated in the appended parameter field.
+
+##### 7.3.2.3 Sync Mechanism
+
+If a SYNC program execution is required by the CA, the LA shall proceed as follows:
+
+- after a Request-TDD is stored, the LA shall issue a SYNC to the CA ("SyncJob" function);
+- before the LA polls a Response-TDD, another SYNC to the CA shall be issued ("SyncAck" function).
+
+Under DOS, OS/2, UNIX and UNIX-like operating system, the SYNC mechanism shall be implemented by executing the "APPLI/COM" program from the LA.
+
+The "SyncJob" and "SyncAck" functions (see above) are encoded as follows:
+
+SyncJob: *EXEC APPLI/COM JOB*
+
+SyncAck: *EXEC APPLI/COM ACK*
+
+*EXEC* stands for the platform specific command to launch an executable program.
+
+![Diagram illustrating the File Exchange Method-TDD Transfer between LA and CA.](57939c16065211317c5442cf2a4009e0_img.jpg)
+
+The diagram illustrates the File Exchange Method-TDD Transfer between LA (Local Area) and CA (Central Area). LA and CA are represented as rectangular boxes. A horizontal arrow labeled "Sync" points from LA to CA. Above the "Sync" arrow is a box labeled "COM\_JOB" containing three cylinders, each labeled "TDD". An arrow points from LA to the "COM\_JOB" box. Below the "Sync" arrow is a box labeled "COM\_ACK" containing three cylinders, each labeled "TDD". An arrow points from CA to the "COM\_ACK" box, and another arrow points from the "COM\_ACK" box back to LA. The text "T0823420-95/d09" is located at the bottom right of the diagram.
+
+Diagram illustrating the File Exchange Method-TDD Transfer between LA and CA.
+
+FIGURE 11/T.611
+
+##### File Exchange Method-TDD Transfer
+
+## 8 Transfer Formats
+
+For proper operation, some requirements apply to the format of the Outgoing and Incoming Files exchanged between LA and CA. Incoming and Outgoing Files have a specific format which is not necessarily the same as the one used by the Transmission Files, e.g. a word processing file to be exchanged through the basic mode of the telefax service. In this case, format conversions are required (they shall be handled by the CA).
+
+In order to exchange documents between LA and CA several Transfer Formats are defined by this Recommendation. The Transfer Formats apply to the Transfer Files defined in 2.1. These formats should not be confused with the format transmitted through the network (Transmission Formats) by the telecommunications services nor should they be confused with the format used by TTDs (TDD coding).
+
+Several Transfer Formats are possible:
+
+- text oriented Transfer Formats;
+- graphic oriented Transfer Formats;
+- the transparent Transfer Format;
+- private Transfer Formats which are either text or graphic oriented.
+
+This Recommendation defines:
+
+- 3 text oriented Transfer Formats (APPLI/COM Extended ASCII, APPLI/COM Standard ASCII and the Teletex Format);
+- 1 graphic oriented Transfer Format (APPLI/COM TIFF);
+- the Transparent Format Transfer Format.
+
+The Transparent Format may be used only if the document is to be transmitted as a binary file by the telecommunications service. In this case, no conversion of the contents of the file takes place thus the file will be transmitted unchanged.
+
+This Recommendation is open for the support of private transfer formats. Hence other Transfer Formats (e.g. PostScript) may be implemented by CA manufacturers to adapt native formats of commonly used application programs (e.g word processors, data-bases or spreadsheets). To inform a LA about this support, the CA shall place the keyword ADDCONV into the CA-Descriptor of the ICE (see clause 9).
+
+A CA supporting an additional Transfer Format has to ensure that documents are treated properly for all services supported by the CA. Restrictions imposed by the service itself have to be treated in a transparent way. Anyway, the Transfer Formats supported by CA manufacturers shall be described in their related documentation.
+
+Table 49 indicates how Transfer Formats shall be supported by the CA depending on the operating system and the telecommunications service the CA offers.
+
+TABLE 49/T.611
+
+### **List of Transfer Formats**
+
+| Transfer Format             | Convert-id | Means                                                                                                                                                                                                |
+|-----------------------------|------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| APPLI/COM<br>Extended ASCII | ASCII437   | ASCII Transfer Format as defined in 8.1.1. Use of this format is restricted to some services. See 8.4                                                                                                |
+|                             | ASCII      | ASCII Transfer Format as defined on the supporting CA. This Transfer Format may differ from the ASCII437 Transfer Format on those systems which do not support the same extended ASCII character set |
+| APPLI/COM<br>Standard ASCII | T.50       | T.50 (IRA) Transfer Format as defined in 8.1.2. Use of this format is restricted to some services. See 8.4                                                                                           |
+| Teletex Format              | T.61       | T.61 Transfer Format as defined in 8.2. Use of this format is restricted to some services. See 8.4                                                                                                   |
+| APPLI/COM TIFF              | TIFF       | TIFF Transfer Format as defined in 8.3. Use of this format is restricted to some services. See 8.4                                                                                                   |
+| Transparent Format          | VOID       | Stands for "no conversion to be done". Use is restricted for transparent transfer of document in various "file transfer" modes of the telecommunications services                                    |
+
+The Transfer Formats defined in this Recommendation can be read and generated for the appropriate services under the appropriate operating systems by conforming CAs.
+
+NOTE 1 – The text-oriented Transfer Formats for the telefax service are supported in the outgoing direction only.
+
+Documents that are transferred to the CA in a text-oriented format shall be edited by the application in such a way that the format and character set correspond to the requirements of the service, i.e. set the "number of characters/line", "lines/page", "character pitch", "line spacing" and attributes such as "underline", "superscript" and "subscript".
+
+The CA may reject documents with an incorrect format or character set.
+
+NOTE 2 – If a LA wants to achieve service-independence the LA can use one of the "ASCII"-based formats for document transfer, since they are the only Transfer Formats that cover most services.
+
+### 8.1 APPLI/COM Transfer Formats: Extended and Standard ASCII
+
+The format codes shown in Table 50 are defined for the Transfer Formats APPLI/COM Extended ASCII and APPLI/COM Standard ASCII. Not all services permit all the format specifications listed (see 8.4). A CA is allowed to ignore ESC sequences. Furthermore, depending on the resident fonts used to perform ASCII to T.4 (or T.6) conversions, the CA is allowed to fold lines or rotate pages when required, except if this is disabled explicitly by the LA; in this case, if the CA may reject conversion or perform it downgraded.
+
+TABLE 50/T.611
+
+**Format Effectors for APPLI/COM ASCII Transfer Formats**
+
+| Format                                                                                                                                                                                                                                                                                                                                                                                                                                             | Possible Values             | HEX       | ASCII     | Default |
+|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------|-----------|-----------|---------|
+| Orientation                                                                                                                                                                                                                                                                                                                                                                                                                                        | Portrait                    | 1B 4F 30  | ESC O 0   | √       |
+|                                                                                                                                                                                                                                                                                                                                                                                                                                                    | Landscape                   | 1B 4F 31  | ESC O 1   |         |
+| Pitch                                                                                                                                                                                                                                                                                                                                                                                                                                              | 10 Pitch                    | 1B 50 30  | ESC P 0   | √       |
+|                                                                                                                                                                                                                                                                                                                                                                                                                                                    | 12 Pitch                    | 1B 50 31  | ESC P 1   |         |
+|                                                                                                                                                                                                                                                                                                                                                                                                                                                    | 15 Pitch                    | 1B 50 32  | ESC P 2   |         |
+| Line spacing                                                                                                                                                                                                                                                                                                                                                                                                                                       | 6 lines/inch (1 spacing)    | 1B 4C 30  | ESC L 0   | √       |
+|                                                                                                                                                                                                                                                                                                                                                                                                                                                    | 4 lines/inch (1.5 spacing)  | 1B 4C 31  | ESC L 1   |         |
+|                                                                                                                                                                                                                                                                                                                                                                                                                                                    | 3 lines/inch (2 spacing)    | 1B 4C 32  | ESC L 2   |         |
+|                                                                                                                                                                                                                                                                                                                                                                                                                                                    | 12 lines/inch (0.5 spacing) | 1B 4C 33  | ESC L 3   |         |
+| Attributes                                                                                                                                                                                                                                                                                                                                                                                                                                         | Underline off               | 1B 55 30  | ESC U 0   | √       |
+|                                                                                                                                                                                                                                                                                                                                                                                                                                                    | Underline on                | 1B 55 31  | ESC U 1   |         |
+|                                                                                                                                                                                                                                                                                                                                                                                                                                                    | Superscript off             | 1B 41 30  | ESC A 0   | √       |
+|                                                                                                                                                                                                                                                                                                                                                                                                                                                    | Superscript on              | 1B 41 31  | ESC A 1   |         |
+|                                                                                                                                                                                                                                                                                                                                                                                                                                                    | Subscript off               | 1B 56 30  | ESC V 0   | √       |
+|                                                                                                                                                                                                                                                                                                                                                                                                                                                    | Subscript on                | 1B 56 31  | ESC V 1   |         |
+|                                                                                                                                                                                                                                                                                                                                                                                                                                                    | Boldface off                | 1B 42 30  | ESC B 0   | √       |
+|                                                                                                                                                                                                                                                                                                                                                                                                                                                    | Boldface on                 | 1B 42 31  | ESC B 1   |         |
+|                                                                                                                                                                                                                                                                                                                                                                                                                                                    | Strike-out off              | 1B 53 30  | ESC S 0   | √       |
+|                                                                                                                                                                                                                                                                                                                                                                                                                                                    | Strike-out on               | 1B 53 31  | ESC S 1   |         |
+|                                                                                                                                                                                                                                                                                                                                                                                                                                                    | Italics off                 | 1B 49 30  | ESC I 0   | √       |
+|                                                                                                                                                                                                                                                                                                                                                                                                                                                    | Italics on                  | 1B 49 31  | ESC I 1   |         |
+| Text makeup                                                                                                                                                                                                                                                                                                                                                                                                                                        | Fold lines disallowed       | 1B 54 30  | ESC T 0   |         |
+|                                                                                                                                                                                                                                                                                                                                                                                                                                                    | Fold lines allowed          | 1B 54 31  | ESC T 1   | √       |
+|                                                                                                                                                                                                                                                                                                                                                                                                                                                    | Rotate page disallowed      | 1B 52 30  | ESC R 0   |         |
+|                                                                                                                                                                                                                                                                                                                                                                                                                                                    | Rotate page allowed         | 1B 52 31  | ESC R 1   | √       |
+|                                                                                                                                                                                                                                                                                                                                                                                                                                                    | New line                    | 0D 0A     | CR LF     |         |
+|                                                                                                                                                                                                                                                                                                                                                                                                                                                    | New page                    | 0D 0C     | CR FF     |         |
+| Font selection                                                                                                                                                                                                                                                                                                                                                                                                                                     | Select font number n        | 1B 43 'n' | ESC C 'n' | 'n' = 0 |
+| NOTE – The fonts to be selected have to be declared in the ICE (see clause 9). The fonts are normally fixed width fonts, with a fixed character spacing. The conversion process shall ensure that characters shall neither overlap, nor be lost in the process. For large font sizes, the line spacing may increase and the formatting change. However, it is the CA responsibility to ensure that no contents is lost and text lines are legible. |                             |           |           |         |
+
+#### 8.1.1 Character set of the APPLI/COM Extended ASCII Transfer Format
+
+The characters supported by the APPLI/COM Extended ASCII Transfer Format for the Teletex, Telex and Telefax services are shown in Tables 51, 52 and 53<sup>6)</sup>. This Transfer Format may be invoked in two ways:
+
+- by specifying the parameter value "ASCII437" in the keyword "Convert" on those systems which implement the code page 437. These systems shall declare it in the ICE;
+- by specifying the parameter value "ASCII" in the keyword "Convert" on those systems which implement the code page 437 as their native character set.
+
+Otherwise, only the lower part of the table (i.e. octets from 20<sub>HEX</sub> to 7E<sub>HEX</sub>) is guaranteed to be faithfully converted.
+
+NOTE – The following tables shall be read by selecting first a column, then a row, i.e. character "A" is column 4, row 1.
+
+#### 8.1.2 Character set of the APPLI/COM Standard ASCII Transfer Format
+
+The characters supported by the APPLI/COM Standard ASCII Transfer Format for the Teletex, Telex and Telefax services are shown in Tables 54, 55 and 56.
+
+### 8.2 APPLI/COM Transfer Format: T.61
+
+The APPLI/COM T.61 Transfer Format exactly corresponds to the ITU-T Recommendation T.61 for the Teletex service. Documents that the application transfers in this format are mapped to the Teletex service as it is. The format and codes shall be checked by the CA, but no conversion shall be performed. This format is suitable for applications that either already generate this format or are meant to transmit complex text layouts via the Teletex service.
+
+### 8.3 APPLI/COM Transfer Format: TIFF
+
+TIFF is a graphics oriented transfer format. The name TIFF stands for "Tagged Image File Format". The format of TIFF files includes the attributes that describe the image, such as resolution and dimensions, and are incorporated via tags in the TIFF file header. Because the information can be reached via tags, the program that generates TIFF files (TIFF writer) is not bound to a constant file structure, since a TIFF read program (TIFF reader) simply needs to know the algorithm necessary to locate the tags.
+
+The TIFF Transfer Format offers the following features:
+
+- it contains pixel information;
+- it supports data-compression formats;
+- it is independent of the hardware of the generating system (it works with any byte order);
+- it is flexible due to its own tag structures.
+
+Because of the fact that the number of possible tag combinations are quite high and not all tags defined are required for describing an image, several classes of TIFF formats have been formed during the course of TIFF's development. For this reason, this Recommendation gives a definition of the profile taken as a basis for an interface-compatible TIFF file.
+
+As a TIFF writer, a CA can generate 4 classes of files:
+
+- TIFF standard format, here known as class 1. This is the default class for a CA TIFF writer.
+- TIFF format with compression value 2, here known as class 2. Support of this format is an optional feature of the CA.
+- TIFF format with ITU group 3 compression, here known as class 3. This format is supported by all CAs that serve the group 3 Telefax service.
+- TIFF format with the ITU group 4 compression, here known as class 4. This format is supported by CAs that serve the group 4 Telefax service.
+
+---
+
+<sup>6)</sup> The character set of the APPLI/COM Extended ASCII Transfer Format is a subset of the IBM-PC character set and is therefore highly suitable for implementations using these systems.
+
+TABLE 51/T.611
+
+Character Set of APPLI/COM Extended ASCII Transfer Format for the Telefax Service group 3 and 4  
+(corresponds to the ASCII 437 character set)
+
+| Hex | 00 | 10 | 20 | 30 | 40 | 50 | 60 | 70 | 80 | 90             | A0 | B0 | C0 | D0 | E0 | F0 |
+|-----|----|----|----|----|----|----|----|----|----|----------------|----|----|----|----|----|----|
+| 00  |    |    | SP | 0  | @  | P  | ‘  | p  | Ç  | É              | á  | ░  | └  | ╨  | α  | ≡  |
+| 01  |    |    | !  | 1  | A  | Q  | a  | q  | ü  | æ              | í  | ▒  | ┴  | ╤  | β  | ±  |
+| 02  |    |    | "  | 2  | B  | R  | b  | r  | é  | Æ              | ó  | ▓  | ┬  | ╥  | Γ  | ≥  |
+| 03  |    |    | #  | 3  | C  | S  | c  | s  | â  | ô              | ú  | │  | ├  | ╙  | π  | ≤  |
+| 04  |    | ¶  | \$ | 4  | D  | T  | d  | t  | ä  | ö              | ñ  | ┤  | ─  | ╘  | Σ  | ⌠  |
+| 05  |    | §  | %  | 5  | E  | U  | e  | u  | à  | ò              | Ñ  | ╡  | ┼  | ╒  | σ  | ⌡  |
+| 06  |    |    | &  | 6  | F  | V  | f  | v  | å  | û              | ª  | ╢  | ╞  | ╓  | μ  | ÷  |
+| 07  |    |    | '  | 7  | G  | W  | g  | w  | ç  | ù              | º  | ╖  | ╟  | ╫  | τ  | ≈  |
+| 08  |    |    | (  | 8  | H  | X  | h  | x  | ê  | ÿ              | ¿  | ╕  | ╚  | ╪  | Φ  | °  |
+| 09  |    |    | )  | 9  | I  | Y  | i  | y  | ë  | Ö              | ⌐  | ╣  | ╔  | ┘  | Θ  | ∙  |
+| 0A  |    |    | *  | :  | J  | Z  | j  | z  | è  | Ü              | ¬  | ║  | ╩  | ┌  | Ω  | ·  |
+| 0B  |    |    | +  | ;  | K  | [  | k  | {  | ï  | ¢              | ½  | ╗  | ╦  | █  | δ  | √  |
+| 0C  |    |    | ,  | <  | L  | \  | l  |    | î  | £              | ¼  | ╝  | ╠  | ▄  | ∞  | ⁿ  |
+| 0D  |    |    | -  | =  | M  | ]  | m  | }  | ì  | ¥              | ¡  | ╜  | ═  | ▌  | ∅  | ²  |
+| 0E  |    |    | .  | >  | N  | ^  | n  | ~  | Ä  | P <sub>t</sub> | «  | ╛  | ╬  | ▐  | ∈  | ■  |
+| 0F  |    |    | /  | ?  | O  | _  | o  |    | Å  | ƒ              | »  | ┐  | ╧  | ▀  | ∩  |    |
+
+T0823430-95/d10
+
+| Conversion direction                                                                                                                                                                                                                                                            | Action performed                                                                                                                                       |
+|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Outgoing                                                                                                                                                                                                                                                                        | All characters shown in the table are accepted into the Teletex service character set                                                                  |
+| Incoming                                                                                                                                                                                                                                                                        | The Transfer Format is not generated in this direction [except in such configurations where the CA is capable of OCR (Optional Character Recognition)] |
+| NOTE – The “BACKSLASH” (5C <sub>HEX</sub> ) and “BRACES” (7B <sub>HEX</sub> and 7D <sub>HEX</sub> ) characters, which are often used under DOS and OS/2, do not belong to the basic Teletex character set. Therefore, they must not be used in documents sent via this service. |                                                                                                                                                        |
+
+TABLE 52/T.611  
+Character Set of APPLI/COM Extended ASCII Transfer Format for the Teletex service
+
+| Hex | 00 | 10 | 20 | 30 | 40 | 50 | 60 | 70 | 80 | 90 | A0 | B0 | C0 | D0 | E0 | F0 |
+|-----|----|----|----|----|----|----|----|----|----|----|----|----|----|----|----|----|
+| 00  |    |    | SP | 0  | @  | P  | '  | p  | Ç  | É  | á  |    |    |    |    |    |
+| 01  |    |    | !  | 1  | A  | Q  | a  | q  | ü  | æ  | í  |    |    |    | β  | ±  |
+| 02  |    |    | "  | 2  | B  | R  | b  | r  | é  | Æ  | ó  |    |    |    |    |    |
+| 03  |    |    | #  | 3  | C  | S  | c  | s  | â  | ô  | ú  |    |    |    |    |    |
+| 04  |    | ¶  | \$ | 4  | D  | T  | d  | t  | ä  | ö  | ñ  |    |    |    |    |    |
+| 05  |    | §  | %  | 5  | E  | U  | e  | u  | à  | ò  | Ñ  |    |    |    |    |    |
+| 06  |    |    | &  | 6  | F  | V  | f  | v  | å  | û  | ª  |    |    |    | μ  | ÷  |
+| 07  |    |    | '  | 7  | G  | W  | g  | w  | ç  | ù  | º  |    |    |    |    |    |
+| 08  |    |    | (  | 8  | H  | X  | h  | x  | ê  | ÿ  | ¿  |    |    |    |    | °  |
+| 09  |    |    | )  | 9  | I  | Y  | i  | y  | ë  | Ö  |    |    |    |    |    | •  |
+| 0A  |    |    | *  | :  | J  | Z  | j  | z  | è  | Ü  |    |    |    |    | Ω  | ·  |
+| 0B  |    |    | +  | ;  | K  | [  | k  |    | ï  | ø  | ½  |    |    |    |    |    |
+| 0C  |    |    | ,  | <  | L  |    | l  |    | î  | £  | ¼  |    |    |    |    |    |
+| 0D  |    |    | -  | =  | M  | ]  | m  |    | ì  | ¥  | ¡  |    |    |    |    | ²  |
+| 0E  |    |    | .  | >  | N  | ^  | n  | ~  | Ä  |    | «  |    |    |    |    |    |
+| 0F  |    |    | /  | ?  | O  | _  | o  |    | Å  |    | »  |    |    |    |    |    |
+
+T0823440-95/d11
+
+| Conversion direction | Action performed                                                                                                                                                                                                                                                                                                                                                     |
+|----------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Outgoing             | All characters shown in the table are accepted into the Teletex service character set                                                                                                                                                                                                                                                                                |
+| Incoming             | In the receive direction some characters can come from the service that are not contained in the table. These shall fall back onto characters that look similar to the original or by the character «?» (3F <sub>HEX</sub> ). The character FA <sub>HEX</sub> is not generated in the receive direction anyway. The character F9 <sub>HEX</sub> is generated instead |
+
+TABLE 53/T.611  
+Character Set of APPLI/COM Extended ASCII Transfer Format for the telex service
+
+| Hex | 00 | 10 | 20 | 30 | 40 | 50 | 60 | 70 | 80 | 90 | A0 | B0 | C0 | D0 | E0 | F0 |
+|-----|----|----|----|----|----|----|----|----|----|----|----|----|----|----|----|----|
+| 00  |    |    | SP | 0  |    | P  |    | p  |    |    |    |    |    |    |    |    |
+| 01  |    |    |    | 1  | A  | Q  | a  | q  |    |    |    |    |    |    |    |    |
+| 02  |    |    |    | 2  | B  | R  | b  | r  |    |    |    |    |    |    |    |    |
+| 03  |    |    |    | 3  | C  | S  | c  | s  |    |    |    |    |    |    |    |    |
+| 04  |    |    |    | 4  | D  | T  | d  | t  |    |    |    |    |    |    |    |    |
+| 05  |    |    |    | 5  | E  | U  | e  | u  |    |    |    |    |    |    |    |    |
+| 06  |    |    |    | 6  | F  | V  | f  | v  |    |    |    |    |    |    |    |    |
+| 07  |    |    | '  | 7  | G  | W  | g  | w  |    |    |    |    |    |    |    |    |
+| 08  |    |    | (  | 8  | H  | X  | h  | x  |    |    |    |    |    |    |    |    |
+| 09  |    |    | )  | 9  | I  | Y  | i  | y  |    |    |    |    |    |    |    |    |
+| 0A  |    |    | :  |    | J  | Z  | j  | z  |    |    |    |    |    |    |    |    |
+| 0B  |    |    | +  |    | K  |    | k  |    |    |    |    |    |    |    |    |    |
+| 0C  |    |    | ,  |    | L  |    | l  |    |    |    |    |    |    |    |    |    |
+| 0D  |    |    | -  | =  | M  |    | m  |    |    |    |    |    |    |    |    |    |
+| 0E  |    |    | .  |    | N  |    | n  |    |    |    |    |    |    |    |    |    |
+| 0F  |    |    | /  | ?  | O  |    | o  |    |    |    |    |    |    |    |    |    |
+
+T0823450-95/d12
+
+| Conversion direction | Action performed                                                                                                                                      |
+|----------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Outgoing             | All characters shown in the table are accepted into the Telex service character set. Uppercase letters are interpreted as lowercase letters           |
+| Incoming             | In the receive direction letters are always encoded in lowercase (Codes 61 <sub>HEX</sub> to 7A <sub>HEX</sub> ). Uppercase letters are not generated |
+
+TABLE 54/T.611  
+**Character Set of APPLI/COM Standard ASCII Transfer Format  
+for the telefax service group 3 and 4**
+
+| Hex | 00 | 10 | 20 | 30 | 40 | 50 | 60 | 70 |
+|-----|----|----|----|----|----|----|----|----|
+| 00  |    |    | SP | 0  | @  | P  | '  | p  |
+| 01  |    |    | !  | 1  | A  | Q  | a  | q  |
+| 02  |    |    | "  | 2  | B  | R  | b  | r  |
+| 03  |    |    | #  | 3  | C  | S  | c  | s  |
+| 04  |    |    | \$ | 4  | D  | T  | d  | t  |
+| 05  |    |    | %  | 5  | E  | U  | e  | u  |
+| 06  |    |    | &  | 6  | F  | V  | f  | v  |
+| 07  |    |    | ,  | 7  | G  | W  | g  | w  |
+| 08  |    |    | (  | 8  | H  | X  | h  | x  |
+| 09  |    |    | )  | 9  | I  | Y  | i  | y  |
+| 0A  |    |    | *  | :  | J  | Z  | j  | z  |
+| 0B  |    |    | +  | ;  | K  | [  | k  | {  |
+| 0C  |    |    | ,  | <  | L  | \  | l  |    |
+| 0D  |    |    | -  | =  | M  | ]  | m  | }  |
+| 0E  |    |    | .  | >  | N  | ^  | n  | ~  |
+| 0F  |    |    | /  | ?  | O  | _  | o  |    |
+
+T0823460-95/d13
+
+| Conversion direction                                                                                                                                                                                                                                                      | Action performed                                                                                          |
+|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------|
+| Outgoing                                                                                                                                                                                                                                                                  | All characters shown in the table are accepted into the Telefax group 3 and group 4 service character set |
+| Incoming                                                                                                                                                                                                                                                                  | The Transfer Format is not generated in this direction                                                    |
+| NOTE – The “BACKSLASH” (5C <sub>HEX</sub> ) and “BRACES” (7B <sub>HEX</sub> and 7D <sub>HEX</sub> ) characters, which are often used under DOS and OS/2, do not belong to the Teletex character set. Therefore, they must not be used in documents sent via this service. |                                                                                                           |
+
+TABLE 55/T.611  
+**Character set of the APPLI/COM Standard ASCII Transfer Format for the teletex service**
+
+| Hex | 00 | 10 | 20 | 30 | 40 | 50 | 60 | 70 |
+|-----|----|----|----|----|----|----|----|----|
+| 00  |    |    | SP | 0  | @  | P  | '  | p  |
+| 01  |    |    | !  | 1  | A  | Q  | a  | q  |
+| 02  |    |    | "  | 2  | B  | R  | b  | r  |
+| 03  |    |    | #  | 3  | C  | S  | c  | s  |
+| 04  |    |    | \$ | 4  | D  | T  | d  | t  |
+| 05  |    |    | %  | 5  | E  | U  | e  | u  |
+| 06  |    |    | &  | 6  | F  | V  | f  | v  |
+| 07  |    |    | '  | 7  | G  | W  | g  | w  |
+| 08  |    |    | (  | 8  | H  | X  | h  | x  |
+| 09  |    |    | )  | 9  | I  | Y  | i  | y  |
+| 0A  |    |    | *  | :  | J  | Z  | j  | z  |
+| 0B  |    |    | +  | ;  | K  | [  | k  |    |
+| 0C  |    |    | ,  | <  | L  |    | l  |    |
+| 0D  |    |    | -  | =  | M  | ]  | m  |    |
+| 0E  |    |    | .  | >  | N  | ^  | n  | ~  |
+| 0F  |    |    | /  | ?  | O  | _  | o  |    |
+
+T0823470-95/d14
+
+| Conversion direction | Action performed                                                                                                                                                   |
+|----------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Outgoing             | All characters shown in the table are accepted into the Teletex service character set                                                                              |
+| Incoming             | In the receive direction, characters can come that are not contained in the above table. Such characters may be replaced by the character “?” (3F <sub>HEX</sub> ) |
+
+TABLE 56/T.611  
+Character set of APPLI/COM Standard ASCII Transfer Format for the Telex service
+
+| Hex | 00 | 10 | 20 | 30 | 40 | 50 | 60 | 70 |
+|-----|----|----|----|----|----|----|----|----|
+| 00  |    |    | SP | 0  |    | P  |    | p  |
+| 01  |    |    |    | 1  | A  | Q  | a  | q  |
+| 02  |    |    |    | 2  | B  | R  | b  | r  |
+| 03  |    |    |    | 3  | C  | S  | c  | s  |
+| 04  |    |    |    | 4  | D  | T  | d  | t  |
+| 05  |    |    |    | 5  | E  | U  | e  | u  |
+| 06  |    |    |    | 6  | F  | V  | f  | v  |
+| 07  |    |    | '  | 7  | G  | W  | g  | w  |
+| 08  |    |    | (  | 8  | H  | X  | h  | x  |
+| 09  |    |    | )  | 9  | I  | Y  | i  | y  |
+| 0A  |    |    |    | :  | J  | Z  | j  | z  |
+| 0B  |    |    | +  |    | K  |    | k  |    |
+| 0C  |    |    | ,  |    | L  |    | l  |    |
+| 0D  |    |    | -  | =  | M  |    | m  |    |
+| 0E  |    |    | .  |    | N  |    | n  |    |
+| 0F  |    |    | /  | ?  | O  |    | o  |    |
+
+T0823480-95/d15
+
+| Conversion direction | Action performed                                                                                                                                      |
+|----------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Outgoing             | All characters shown in the table are accepted into the Telex service character set. Uppercase letters are interpreted as lowercase letters           |
+| Incoming             | In the receive direction letters are always encoded in lowercase (Codes 61 <sub>HEX</sub> to 7A <sub>HEX</sub> ). Uppercase letters are not generated |
+
+#### 8.3.1 APPLI/COM TIFF Profile
+
+The tags recognized by a CA and their handling are summarized in Table 57.
+
+TABLE 57/T.611
+
+APPLI/COM TIFF Profile table
+
+| Tag |                            | TIFF-Reader                          |                     | TIFF-Writer         |                     |                     |                     |
+|-----|----------------------------|--------------------------------------|---------------------|---------------------|---------------------|---------------------|---------------------|
+| HEX | Name                       | Accepted value (dec)                 | Default value (dec) | Class 1 value (dec) | Class 2 value (dec) | Class 3 value (dec) | Class 4 value (dec) |
+| FE  | NewSubfileType (Note 1)    | "0", "2"                             | "0"                 | "0"                 | "0"                 | "0"                 | "0"                 |
+| FF  | SubfileType (Note 1)       | "0", "2"                             | "0"                 | "0"                 | "0"                 | "0"                 | "0"                 |
+| 100 | ImageWidth                 | 'Width' (Note 2)                     | Reject              | 'Width'             | 'Width'             | 'Width'             | 'Width'             |
+| 101 | ImageLength                | 'Length' (Note 3)                    | Reject              | 'Length'            | 'Length'            | 'Length'            | 'Length'            |
+| 102 | BitsPerSample              | "1"                                  | "1"                 | "1"                 | "1"                 | "1"                 | "1"                 |
+| 103 | Compression                | "1", "2", "3", "4", "32773" (Note 4) | "1"                 | "1"                 | "2"                 | "3"                 | "4"                 |
+| 106 | Photometric-Interpretation | "0", "1"                             | "0"                 | "0"                 | "0"                 | "0"                 | "0"                 |
+| 107 | Thresholding               | Ignore                               |                     | None                |                     |                     |                     |
+| 108 | CellWidth                  | Ignore                               |                     | None                |                     |                     |                     |
+| 109 | CellLength                 | Ignore                               |                     | None                |                     |                     |                     |
+| 10A | FillOrder                  | "1", "2" (Note 5)                    | "1"                 | "1"                 | "1"                 | "2"                 | "2"                 |
+| 10D | DocumentName               | Ignore                               |                     | None                |                     |                     |                     |
+| 10E | ImageDescription           | Ignore                               |                     | None                |                     |                     |                     |
+| 10F | Make                       | Ignore                               |                     | None                |                     |                     |                     |
+| 110 | Model                      | Ignore                               |                     | None                |                     |                     |                     |
+| 111 | StripOffsets               | 'Offset'                             | Reject              | 'Offset'            | 'Offset'            | 'Offset'            | 'Offset'            |
+| 112 | Orientation                | "1"                                  | "1"                 | "1"                 | "1"                 | "1"                 | "1"                 |
+| 115 | SamplesPerPixel            | "1"                                  | "1"                 | "1"                 | "1"                 | "1"                 | "1"                 |
+| 116 | RowsPerStrip               | 'Rows'                               | Reject              | 'Rows'              | 'Rows'              | 'Rows'              | 'Rows'              |
+| 117 | StripByteCounts            | 'Count'                              | Reject              | 'Count'             | 'Count'             | 'Count'             | 'Count'             |
+| 118 | MinSampleValue             | "0"                                  | "0"                 | "0"                 | "0"                 | "0"                 | "0"                 |
+| 119 | MaxSampleValue             | "1"                                  | "1"                 | "1"                 | "1"                 | "1"                 | "1"                 |
+| 11A | XResolution                | "300" (Note 6)                       | "300"               | "300"               | "300"               | 'X-res'             | 'X-res'             |
+| 11B | YResolution                | "300" (Note 6)                       | "300"               | "300"               | "300"               | 'Y-res'             | 'Y-res'             |
+
+TABLE 57/T.611 (*end*)**APPLI/COM TIFF Profile table**
+
+| Tag |                     | TIFF-Reader          |                     | TIFF-Writer         |                     |                     |                     |
+|-----|---------------------|----------------------|---------------------|---------------------|---------------------|---------------------|---------------------|
+| HEX | Name                | Accepted value (dec) | Default value (dec) | Class 1 value (dec) | Class 2 value (dec) | Class 3 value (dec) | Class 4 value (dec) |
+| 11C | PlanarConfiguration | "1"                  | "1"                 | "1"                 | "1"                 | "1"                 | "1"                 |
+| 11D | PageName            | Ignore               |                     | None                |                     |                     |                     |
+| 11E | XPosition           | Ignore               |                     | None                |                     |                     |                     |
+| 11F | YPosition           | Ignore               |                     | None                |                     |                     |                     |
+| 120 | FreeOffsets         | Ignore               |                     | None                |                     |                     |                     |
+| 121 | FreeByteCount       | Ignore               |                     | None                |                     |                     |                     |
+| 122 | GrayResponseUnit    | Ignore               |                     | None                |                     |                     |                     |
+| 123 | GrayResponseCurve   | Ignore               |                     | None                |                     |                     |                     |
+| 124 | Group3Options       | "0", "4"<br>(Note 7) | "0"                 | "0"                 | "0"                 | "4"                 | "4"                 |
+| 125 | Group4Options       | "0", "4"<br>(Note 7) | "0"                 | "0"                 | "0"                 | "4"                 | "0"                 |
+| 128 | ResolutionUnit      | "2"                  | "2"                 | "2"                 | "2"                 | "2"                 | "2"                 |
+| 129 | PageNumber          | 'Page'               | Reject              | 'Page'              | 'Page'              | 'Page'              | 'Page'              |
+| 12C | ColorResponseUnit   | Ignore               |                     | None                |                     |                     |                     |
+| 12D | ColorResponseCurve  | Ignore               |                     | None                |                     |                     |                     |
+
+##### NOTES
+
+1 Both NewSubfileType and SubfileType tags should be accepted by the readers. The writer should generate the NewSubfileType tag only because it has superseded the SubfileType tag.
+
+2 The following applies: ImageWidth//XResolution  $\leq$  215 mm. If the quotient is exceeded, the document can be rejected. Hence, if the XResolution is 204 dpi (G3 fax standard), the value 1728 for ImageWidth is not exceeded.
+
+3 ImageLength is processed if the following applies to the quotient ImageLength/YResolution  $<$  297 mm. This corresponds to the length of a DIN A4 sheet of paper. The guarantee applies up to a resolution of 300 dpi. The processing of higher ImageLength values is an optional feature of the CA.
+
+4 Support of Compression values:
+
+- 1: (uncompressed) is guaranteed only if the resolution value (XResolution, YResolution) is 300 dpi or exactly corresponds to that of the fax service selected.
+- 2: is an optional feature of the CA.
+- 3 or 4: ITU group 3/4 compression is guaranteed only if the resolution value (XResolution, YResolution) exactly corresponds to the resolutions of the Telefax services selected.
+- 32773: (pack-bits compression) is an optional feature of the CA.
+
+5 The FillOrder value 2 (= 'reverse bit-order') is allowed only if the Compression value is 3 or 4.
+
+6 For Compression values 3 and 4 the actual resolution value (XResolution, YResolution) in dpi that exactly corresponds to that of the Telefax service selected shall be specified. The default value of the reader does not apply since the X and Y resolution shall be applied. The LA is responsible for local conversion of received resolutions.
+
+7 If the Compression value is 3, the value of the Group3Options is 4; otherwise, it is 0. Other combinations shall be rejected.
+
+Table 58 summarizes the rules applying to the TIFF Profile table.
+
+TABLE 58/T.611
+
+##### **Rules for TIFF Profile table**
+
+| Column                  | Rule                                                                                                                                                                                                                                          |
+|-------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Tag                     | Identifies the name of the tag and its value in hexadecimal notation. If a tag not listed here is encountered by a TIFF reader, the reader may reject the TIFF file                                                                           |
+| Reader – Accepted value | Summarizes the accepted values. Only the values listed are guaranteed to be accepted by a CA. Other values may be rejected by a CA and thus shall be avoided by a generating LA. If a value states "ignore", the tag is ignored by the reader |
+| Reader – Default value  | Shows the default value applied if the tag is not specified. If a value states "reject", the TIFF file shall be rejected if the tag is absent. If a value states "ignore", no default is applicable, since the tag is ignored by the reader   |
+| Writer                  | The writer columns contain the values generated by the appropriate CA TIFF writer class. If a value states "none", no tag and value is generated in this class                                                                                |
+
+### 8.4 Service Constraints applying to Transfer Formats
+
+Due to the nature of the telecommunications services selected, several constraints are applied to the transfer formats. These constraints are summarized in Table 59.
+
+TABLE 59/T.611
+
+#### **Transfer Format Constraints**
+
+| Telecommunications Service                           | Allowed Transfer Format   | Constraints                                                                                                                                                                                  |
+|------------------------------------------------------|---------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Telex                                                | ASCII, T.50               | No format specifications but the text makeup is allowed. All other specifications shall be ignored. There are also constraints in the character set                                          |
+| Teletex                                              | ASCII, T.50, T.61         | Only the Teletex specific format specifications are allowed. All other specifications shall be either ignored or the file shall be rejected. There are also constraints in the character set |
+|                                                      | VOID                      | Only allowed in conjunction with a TFT (Telematic File Transfer) type selection                                                                                                              |
+| Telefax (G3/G4)                                      | ASCII, T.50 <sup>a)</sup> | All formats and attributes are allowed. If a CA does not support a specific attribute or format, it is allowed to ignore it                                                                  |
+|                                                      | TIFF                      | Only allowed if none of the TFT (Telematic File Transfer) types was selected                                                                                                                 |
+|                                                      | VOID                      | Only allowed in conjunction with a TFT (Telematic File Transfer) type selection                                                                                                              |
+| <sup>a)</sup> Only applicable in outgoing direction. |                           |                                                                                                                                                                                              |
+
+## 9 ICE
+
+Before a LA can start interacting with a CA, the LA needs to know which CA it requires (based on criteria like the type of telecommunication services supported) and how to "talk" to that CA. Since the interface described in this Recommendation aims at multiple platforms, the mechanism prescribed to obtain information from CAs prior to interacting with them is based on reading configuration information. This configuration information is named the Interface Configuration Environment (ICE).
+
+A CA provider shall supply this configuration information, so that LAs can get information about a specific CA and the access to that CA.
+
+The part of the ICE which gives information about a specific CA is called the CA-Descriptor. Depending on whether the system is a standalone system or utilizes a Local Area Network (LAN), information about the reachable CAs can be found in different places. Since multiple CAs can be reachable by a LA, there is a need for centralizing the locations of the individual CA-Descriptors in a "Master ICE" file. The location of the Master ICE file itself is defined on a per-platform basis (see Annex B).
+
+Therefore, on a given system, a LA shall first read the Master ICE file to discover which CAs it can reach and the location of those CAs' CA-Descriptors. Then the LA reads the CA-Descriptor of the CA it wants to utilize. Finally, the LA logs in to that CA by using the information found in that CA's CA-Descriptor.
+
+To illustrate these concepts, three typical configurations can be considered:
+
+- a) a standalone system supporting multiple LAs and multiple CAs;
+- b) a LAN-based system where LAs and CAs are located on different machines, and a file server is present;
+- c) a LAN-based system where LAs and CAs are located on different machines, and no file server is present;
+
+In case a), the Master ICE is located in a specific file path (the precise location depends on the platform, see Annex B), and the Master ICE lists all the CAs on that system with the location of their respective CA-Descriptor (see Figure 12).
+
+![Diagram of a standalone system supporting multiple CAs. A computer icon is connected via a double-headed arrow to a 'Access to Telecommunication Services' block. To the right, a 'Master ICE' cylinder is connected by arrows to three 'CA-Descriptor' cylinders labeled 'for CA #n', 'for CA #2', and 'for CA #1'.](8a0a9aa5fac5d73eefb772afd44649f6_img.jpg)
+
+Standalone Computer running CA(s)
+
+```
+graph TD; Computer[Computer] <-->|Access to Telecommunication Services| ATSS[Access to Telecommunication Services]; MasterICE[(Master ICE)]; CA1[(CA-Descriptor for CA #1)]; CA2[(CA-Descriptor for CA #2)]; CAn[(CA-Descriptor for CA #n)]; MasterICE --> CA1; MasterICE --> CA2; MasterICE --> CAn;
+```
+
+T0823490-95/d16
+
+Diagram of a standalone system supporting multiple CAs. A computer icon is connected via a double-headed arrow to a 'Access to Telecommunication Services' block. To the right, a 'Master ICE' cylinder is connected by arrows to three 'CA-Descriptor' cylinders labeled 'for CA #n', 'for CA #2', and 'for CA #1'.
+
+FIGURE 12/T.611  
+Standalone System supporting multiple CAs
+
+In case b), the Master ICE is located on the file server, in a file path that all workstations can reach. The Master ICE lists all the CAs on the LAN and gives the absolute paths of their respective CA-Descriptor (which can be located on other machines than the file server itself) (see Figure 13).
+
+![Diagram of a LAN-based system with a file server. A central horizontal bar represents the LAN. Above the LAN, two workstations are shown. Each workstation has a computer icon and a cylinder labeled 'CA-Descriptor for CA #1' and 'CA-Descriptor for CA #2' respectively. Below the LAN, a workstation and a file server are shown. The file server is a tall vertical rectangle with a cylinder labeled 'Master ICE' and the text 'T0823500-95/d17' below it. Dashed lines connect each workstation to the LAN, and the LAN to the workstation and file server below it.](f4fdce3ce1c0fd291f31813f83d0d0d3_img.jpg)
+
+Diagram of a LAN-based system with a file server. A central horizontal bar represents the LAN. Above the LAN, two workstations are shown. Each workstation has a computer icon and a cylinder labeled 'CA-Descriptor for CA #1' and 'CA-Descriptor for CA #2' respectively. Below the LAN, a workstation and a file server are shown. The file server is a tall vertical rectangle with a cylinder labeled 'Master ICE' and the text 'T0823500-95/d17' below it. Dashed lines connect each workstation to the LAN, and the LAN to the workstation and file server below it.
+
+FIGURE 13/T.611  
+LAN based System with File service
+
+In case c), since no file server can centralize the Master ICE file for the whole system, a Master ICE file is located on each machine that supports one or more CAs, at a fixed location as in case a). The location of the CA-Descriptors is recorded in the Master ICE with paths relative to that machine (see Figure 14).
+
+![Diagram of a peer-to-peer LAN system. A central horizontal bar represents the LAN. Above the LAN, two workstations are shown. Each workstation has a computer icon and a cylinder labeled 'CA-Descriptor for CA #1' and 'CA-Descriptor for CA #2' respectively. Above each workstation is another cylinder labeled 'Master ICE'. Below the LAN, two workstations are shown. Dashed lines connect each workstation to the LAN, and the LAN to the workstation and 'Master ICE' above it.](145fb9b19dc6513e7bf84c9ba7f083f2_img.jpg)
+
+Diagram of a peer-to-peer LAN system. A central horizontal bar represents the LAN. Above the LAN, two workstations are shown. Each workstation has a computer icon and a cylinder labeled 'CA-Descriptor for CA #1' and 'CA-Descriptor for CA #2' respectively. Above each workstation is another cylinder labeled 'Master ICE'. Below the LAN, two workstations are shown. Dashed lines connect each workstation to the LAN, and the LAN to the workstation and 'Master ICE' above it.
+
+FIGURE 14/T.611  
+Peer to peer LAN system
+
+### 9.1 Presentation of the ICE
+
+The ICE is presented using readable text coding, as it is described for TDDs in 6.4.1. Except on those systems where the native coding of characters is EBCDIC (Code-ID = "E"), IRA coding is used (Code-ID = "I"). The ICE – Master ICE and CA-Descriptors – shall be presented in form of lines using the IRA character repertoire and shall be formatted as described for TDDs in 6.4.1.
+
+### 9.2 Gaining access to the ICE Information
+
+Access to the Master ICE shall be accomplished by means of a "file access method" which is common to most operating systems. In turn, all of the available access methods to obtain CA-Descriptor information for an individual CA shall be defined within the Master ICE. The access methods may be "file-based" or may take advantage of more dynamic methods which may be available within a particular operating environment (e.g DLLs for Windows and executable files or device drivers for DOS).
+
+### 9.3 Master ICE
+
+The Master ICE file lists all the CAs that a LA can reach. It contains information about the CA identifier, the supported communication services, the type of exchange mechanism supported and the location of the CA's CA-Descriptor where further information can be obtained.
+
+#### 9.3.1 Formal Description
+
+This subclause describes the syntax of the Master ICE. The first syntax element in the Master ICE is the <Master ICE Header>. No other element, including SPACE and TABULATION format effectors are allowed before. The detailed syntax, described in BNF-based grammar is shown below (for a description of the BNF-based grammar see A.1):
+
+```
+<Master ICE> :=                <Master ICE Header> <CA Entries>
+
+<Master ICE Header> :=         "I*APPLI/COM*" <Version> "ITU-T*MASTER_ICE"
+                                -- for definition of <ICE Header> see also 6.3.2.3
+
+<Version> :=                    "1994"
+                                -- <Version> denotes year of approval of this Recommendation
+
+<CA Entries> :=                 "#" <CA Entry> {"#" <CA Entry>}
+
+<CA Entry> :=                   <CA Identifier> <CA Product Info> <CA EM>
+                                <CA Service> {<CA Service>}
+                                <CA ICE Location> {<CA ICE Location>}
+
+<CA Identifier> :=              "CA-ID" ":" NUMERIC-STRING
+                                -- identifies the CA
+
+<CA Product Info> :=            "APPLI/COM" ":" STRING(SIZE(1..255))
+                                -- Information about the product, CA manufacturer-provided
+
+<CA EM> :=                      "EM" ":" "FILE" | "PRIMITIVE"
+                                -- exchange mechanism supported by the CA
+                                -- refer to 7.3
+
+<CA Service> :=                 "SERVICE" ":" <Service-id-parameter>
+                                -- telecommunication services supported by the CA
+                                -- refer to 6.4.5.1 and 10.4
+
+<CA ICE Location> :=            "ACCESS" ":" PATH
+                                -- points to the location of the CA-Descriptor file or driver
+```
+
+#### 9.3.2 Configuration
+
+The Master ICE may be configured either manually by means of an "editor" software during the installation of a particular CA or dynamically by means of an appropriate "driver" software provided by the CA manufacturer<sup>7)</sup>.
+
+The ICE shall be configured so that it takes into account all possible communications applications accessible from within a system<sup>8)</sup>.
+
+### 9.4 CA-Descriptor
+
+The CA-Descriptor contains the information relevant to a given CA. It is composed of sections that group logically related entries.
+
+#### 9.4.1 Formal Description
+
+This subclause describes the syntax of the CA-Descriptor. The first syntax element in the CA-Descriptor is the <CA-Descriptor Header>. No other element, including SPACE and TABULATION format effectors are allowed before. The detailed syntax, described in BNF-based grammar is shown below:
+
+```
+<CA-Descriptor> :=          <CA-Descriptor Header> <CA-Descriptor-component>
+
+<CA-Descriptor Header> :=    "I*APPLI/COM*" <Version> "ITU-T*ICE"
+                             -- for definition of <CA-Descriptor Header> see also 6.3.2.3
+
+<Version> :=                  "1994"
+                             -- <Version> denotes year of approval of this Recommendation
+
+<CA-Descriptor-component> :=  "#" <Section> {<Section>}
+
+<Section> :=                  <Section-Parameter> {<Section-Parameter>}
+
+<Section-Parameter> :=        <Parameter-Name> ":" <Parameter-Value>
+
+<Parameter-Name> :=           STRING(SIZE(1..16))
+
+<Parameter-Value> :=          STRING(SIZE(1..255))
+```
+
+#### 9.4.2 Configuration
+
+The CA-Descriptor information shall be provided by the CA-Manufacturer in the form of a file or via a dynamic means such as a device driver, executable file or DLL. The access method(s) for the CA-Descriptor shall be defined in the Master ICE as part of the installation procedure for each CA. The CA-Descriptor may be configured either manually by means of an "editor" software during the installation of a particular CA or dynamically by means of an appropriate "driver" software provided by the CA manufacturer. However, a LA relying on the information from a CA-Descriptor regarding a particular CA shall not assume that the CA is active at that very moment (loaded and running). To be certain that a particular CA is really active, the LA shall login to that CA. Only when login succeeds shall the CA be considered active. For information about the login procedure refer to 7.1 and 7.2.1.
+
+### 9.5 CA-Descriptor Components
+
+Tables 60, 61 and 62 describe the relevant keyword and the corresponding parameter values of the CA-Descriptor. Subclause 6.4.4 gives complementary information about the coding of the parameter values.
+
+---
+
+<sup>7)</sup> Since access to files and to operating system device drivers is similar on popular operating systems, the Master ICE itself may be implemented statically as a file or dynamically in form of an operating system device driver.
+
+<sup>8)</sup> It is not necessary for a CA to run within the same physical equipment as the LA does. The CA must only provide access by means of a device driver or similar.
+
+#### 9.5.1 Parameters of the GENERAL Section
+
+See Table 60.
+
+TABLE 60/T.611
+
+##### CA-Descriptor information items independent of operating system or exchange mechanism
+
+| Keyword <sup>a)</sup>                                                                | Parameter                           | Interpretation                                                                                                                                                                                                                                                                                                                                                                                               |
+|--------------------------------------------------------------------------------------|-------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| ALIAS                                                                                | "yes"   "no"                        | Specifies whether the CA supports alias names (user friendly names)                                                                                                                                                                                                                                                                                                                                          |
+| CODEPAGE*                                                                            | STRING                              | Specifies the additional code pages for the extended ASCII character sets the CA supports. String indicates the number of the code page (e.g. "850")                                                                                                                                                                                                                                                         |
+| CODING*                                                                              | Code-ID                             | Specifies which TDD encoding scheme is supported by the CA. See 63 for the supported values that can be specified. If the Code-ID "E" has to appear in the ICE, its binary value shall be set in accordance to the code presentation chosen for the ICE itself, i.e. if the Code-id of the ICE Header is "I" (APPLI/COM Standard ASCII) then the binary value of the "E" shall be coded as 45 <sub>HEX</sub> |
+| CONVCHK*                                                                             | <Convert-id-parameter>              | Declares which transfer formats are supported in the Submit TDD function CONVERT and/or CHECK. For the syntax of the <Convert-id-parameter> see also 6.4.5.3                                                                                                                                                                                                                                                 |
+| COUNTRY                                                                              | STRING                              | Specifies the country for which the CA is configured. Used to register country specific features like gaining access to the conversion facility or accessing the black list of dialling numbers. The value to be placed in the parameter is to be taken from ITU-T Recommendation T.35. It has to be presented as a decimal counted, numeric string, i.e. "154" for the Seychelles                           |
+| DRF                                                                                  | "yes"   "no"                        | Boolean-parameter; states whether the CA supports the "Dispatch Received Files" facility                                                                                                                                                                                                                                                                                                                     |
+| EXTEND*                                                                              | <keyword>                           | Provides the possibility for extensions to the Recommendation. Can only be implemented as formal changes to the Recommendation. All the CA-supported keywords shall be listed                                                                                                                                                                                                                                |
+| FC                                                                                   | "A"   "B"                           | States which Functional Class the CA supports                                                                                                                                                                                                                                                                                                                                                                |
+| FONT0                                                                                | NUMERIC-STRING                      | A digit in the range "1" .. "9" to specify the number of declared fonts. Fonts are described starting from identifier "Font1" up to "Font 9" (see below)                                                                                                                                                                                                                                                     |
+| FONTx*                                                                               | STRING ","<br>NUMERIC-STRING        | The name of the font followed by the pitch (in characters per inch). The "x" value ranges from 1 to 9                                                                                                                                                                                                                                                                                                        |
+| NATIONAL*                                                                            | <keyword>                           | Provides the possibility for national extensions to the Recommendation. Can only be implemented with the approval of national Administrations. (All supported keywords shall be listed)                                                                                                                                                                                                                      |
+| PRINT*                                                                               | <Printer-id-parameter>              | Declares which printers could be addressed by the CA in the Submit TDD function PRINT. For the syntax of the <Printer-id-parameter> see also 6.4.4.10                                                                                                                                                                                                                                                        |
+| PRIVATE*                                                                             | <keyword>                           | Provides the possibility for private extensions to the Recommendation. (All supported keywords shall be listed)                                                                                                                                                                                                                                                                                              |
+| RECORD*                                                                              | <keyword> ","<br>NUMERIC-STRING     | Gives the complete list of CA-Record field names supported by the CA, in the order they are found in the file resulting from the Trace:COPY function. The CA shall state the keyword followed by – and separated by comma – the length the field will have in the resulting file. See also Table 23                                                                                                          |
+| SUBMIT*                                                                              | "PRINT"  <br>"CONVERT"  <br>"CHECK" | Declares which functions are supported in the Submit TDD function. This keyword shall be repeated as many times as required                                                                                                                                                                                                                                                                                  |
+| a) A "*" (star) at the end of a keyword indicates that this keyword may be repeated. |                                     |                                                                                                                                                                                                                                                                                                                                                                                                              |
+
+#### 9.5.2 Parameters of the EM Section
+
+See Table 61.
+
+TABLE 61/T.611
+
+##### CA-Descriptor information items applying for the file exchange mechanism
+
+| Keyword | Parameter            | Interpretation                                                                                                                              |
+|---------|----------------------|---------------------------------------------------------------------------------------------------------------------------------------------|
+| EM      | "file"   "primitive" | Exchange Method used to interchange TDDs between LAs and CAs. "file" and "primitive" are the supported values (see 7.3 for further details) |
+| SYNC    | "yes"   "no"         | Indicates whether the CA is "sync-driven". See section 7.3 for further details                                                              |
+| F_JOB_Q | PATH                 | Specifies the path of the TDD request files. See 7.3 for further details                                                                    |
+| F_ACK_Q | PATH                 | Specifies the path of the TDD response files. See 7.3 for further details                                                                   |
+| ERROR_Q | PATH                 | Specifies the path of the TDD response files relating to errors. See 7.3 for further details                                                |
+| ALARM   | "yes"   "no"         | This Boolean-parameter states whether the CA supports the SetAlarm function                                                                 |
+
+#### 9.5.3 Parameters of the OPERATING SYSTEM Section
+
+See Table 62.
+
+#### 9.5.4 Parameters of the SERVICE Section
+
+See Table 63.
+
+More service specific information items are described in the related clauses of Part II of this Recommendation.
+
+## 10 Functional Classes and Profiles
+
+### 10.1 Functional Class A
+
+Functional Class A (FCA) specifies a set of Transfer Formats and specifies the interactions between LAs and CAs in order to send and receive documents.
+
+FCA requires the support of:
+
+- the <SendTDD> and the <SendAckTDD> that allows a LA to send a document through a CA;
+- the <ReceiveTDD> that allows a LA to retrieve documents received by a CA.
+
+In addition, the LA may select various CA-offered options like the use of additional keywords ("ADDKEYS") or the provision of the submit functionality ("SUBMIT").
+
+### 10.2 Functional Class B
+
+In addition to FCA features, Functional Class B (FCB) provides the complete Trace functionality.
+
+FCB is a superset of FCA and gives further integration of communications functions to the users' applications.
+
+TABLE 62/T.611
+
+#### **CA-Descriptor information items applying to the operating system**
+
+| Keyword <sup>a)</sup>                                                                           | Parameter                                            | Interpretation                                                                                                                                                                                                                             |
+|-------------------------------------------------------------------------------------------------|------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| ENVIRON*                                                                                        | "MSDOS"  <br>"WINDOWS"   "UNIX"  <br>"OS2"   "MacOS" | This keyword specifies the operating environment of the CA. If a CA supports several environments, the ICE shall contain as many ENVIRON keyword instances as the number of different operating systems supported                          |
+| DRIVER                                                                                          | PATH                                                 | Name of the driver that must be opened to initiate dialogues with the CA. See Annex E for further details                                                                                                                                  |
+| INT                                                                                             | HEX,HEX                                              | Indicates the interrupt number. Two hexadecimal numbers; the first specifies the multiplex number, the second the program code number. If the interrupt is not multiplexed, then the second hex number shall not be specified              |
+| LIB                                                                                             | "yes"   "no"                                         | This Boolean-parameter states whether the CA is a static library (LA must be linked to it)                                                                                                                                                 |
+| LIB-NAME*                                                                                       | PATH                                                 | Path(s) of the library(ies) (used in conjunction with the LIB keyword)                                                                                                                                                                     |
+| DLL                                                                                             | "yes"   "no"                                         | Dynamic Link Library. See Annex E. The 'DLL-NAME' keyword shall be supported only if the DLL exchange mechanism is supported                                                                                                               |
+| DLL-NAME*                                                                                       | PATH                                                 | Path(s) of the DLL file(s) (used in conjunction with the DLL keyword)                                                                                                                                                                      |
+| DDE                                                                                             | "yes"   "no"                                         | Dynamic Data Exchange mechanism. In the WINDOWS environment if the application supports the DDE exchange mechanism, it shall specify "yes". See Annex E. The next three keywords shall be included in the ICE if the DDE mechanism is used |
+| WIN-APP                                                                                         | STRING                                               | Application Name (MsDos format) XXXXXXXX.XXX                                                                                                                                                                                               |
+| SUBJECT*                                                                                        | STRING                                               | All CA "Subjects" shall be mentioned (if any) otherwise leave empty (to be used with the DDE keyword)                                                                                                                                      |
+| ITEM*                                                                                           | STRING                                               | All CA "Items" shall be mentioned (if any) otherwise leave empty (to be used with the DDE keyword)                                                                                                                                         |
+| <sup>a)</sup> A "*" (star) at the end of a keyword indicates that this keyword may be repeated. |                                                      |                                                                                                                                                                                                                                            |
+
+TABLE 63/T.611
+
+#### **CA-Descriptor information items applying to the service section**
+
+| Keyword <sup>a)</sup>                                                                           | Parameter               | Interpretation                                                                                                                                 |
+|-------------------------------------------------------------------------------------------------|-------------------------|------------------------------------------------------------------------------------------------------------------------------------------------|
+| ADDCONV*                                                                                        | STRING<br>(SIZE (1..8)) | Lists additional Transfer Formats supplied by the CA. The names listed here shall be used to select the Transfer Formats at appropriate places |
+| ADDKEYS*                                                                                        | <keyword>               | Lists all the additional keywords supported by the CA. Only keywords classified as "+" in the TDD tables of clause 6 may be specified here     |
+| <sup>a)</sup> A "*" (star) at the end of a keyword indicates that this keyword may be repeated. |                         |                                                                                                                                                |
+
+### **10.3 Additional Functions**
+
+The Submit and Extend functionalities are additional facilities that should be declared in the ICE by the CA (see also 9.5).
+
+### **10.4 Service Profiles**
+
+Support of all the features of a given telecommunication service may be impossible, due to the large number of functions to implement. On the other hand, offering too many options for the support of a given service leads to compliant but incompatible implementations.
+
+To help reduce incompatibilities between different vendors' applications, this Recommendation supports the concept of Service Profiles. A Service Profile groups a defined set of service features that must be supported by the implementations claiming compatibility to this Recommendation.
+
+The set of features to be supported for a given Service Profile is defined on a per-service basis.
+
+An implementation may thus claim compatibility to a Service Profile and support additional features. It is therefore guaranteed that two implementations (i.e. a CA and a LA) supporting the same Service Profile will be able to offer all the features mentioned in the Service Profile, and optionally offer additional features not mandatory for that Service Profile.
+
+CAs shall declare in the Master ICE the Service Profiles supported (see 9.5).
+
+# PART II – SERVICE DEPENDENCIES
+
+## 11 Service: Telefax Group 3
+
+Besides the telefax service specific keywords for <SendTDD>, <SendAckTDD> and <ReceiveTDD>, there is one additional function defined: Poll - to poll a remote fax station for a document to be retrieved. This function shall be implemented using the <ExtendTDD>. The extension is called <PollExtension>
+
+Together with the <PollExtension> also the <SendTDD> and the <SendAckTDD> may be extended to perform a Poll operation while sending a document.
+
+The extensions are described at appropriate places within this clause.
+
+### 11.1 Service Specific Syntax Elements
+
+```
+<ServiceDependentKeywordsSend> :=  
+    ((<Recipient> [<PollSendExtension>]) | <RecipientSpec>)  
+    ((<Document> <Convert> [<Type>] [From] [To]) | <DocumentSpec>)  
+    [<SubAddress>] [<G3Speed>] [<GenCil>] [<HighRes>] [<UseEcm>]
+```
+
+```
+<ServiceDependentKeywordsSendack> :=  
+    <Recipient> [<PollSendExtension>]  
+    ((<Document> <Convert> [<Type>] [From] [To]) | <DocumentSpec>)  
+    [<SubAddress>] [<G3Speed>] [<GenCil>] [<HighRes>] [<UseEcm>]
+```
+
+```
+<ServiceDependentKeywordsReceive> :=  
+    [<Originator>]  
+    ((<Document> <Convert> <Type>) | <DocumentSpec>)  
+    [SubAddress] [<CvFax3>] [<G3Speed>]
+```
+
+```
+<ExtendSubFunctionKeywords> :=  
+    <PollExtension>
+```
+
+```
+<PollSendExtension> :=    <DoPoll> <PollPassword> [<PollSelector>]
+```
+
+```
+<PollExtension> :=  
+    <PollSubFunction> <Recipient> <PollPassword> [<PollSelector>] [<SendTime>]  
+    [<ComId>] [<Minor>] [<Warning>]
+```
+
+See Table 64.
+
+### 11.2 Text Based Encoding
+
+#### 11.2.1 Mapping of Keywords
+
+See Table 65.
+
+#### 11.2.2 Encoding of Parameters
+
+See also 6.4.4 for the encoding of non service dependent parameters used.
+
+##### 11.2.2.1 Service-id-parameter
+
+The Service-id parameter is encoded as STRING set to the constant value "FX3".
+
+*Syntax:*
+
+```
+<Service-id-parameter> :=    "FX3"
+```
+
+TABLE 64/T.611
+
+##### **Additional syntax elements for Telefax Group 3**
+
+| Syntax element               | Purpose                                                                    |
+|------------------------------|----------------------------------------------------------------------------|
+| <Convert>                    | Specifies the Transfer Format to be used                                   |
+| <CvFax3>                     | Specifies the desired Transfer Format for received files                   |
+| <Document>, <DocumentSpec>   | Specifies the document or the documents to be sent or being received       |
+| <DoPoll>                     | Specifies whether recipient shall be polled in a <SendTDD> or <SendAckTDD> |
+| <G3Speed>                    | Specifies the modulation speed desired (input) or that was used (output)   |
+| <GenCil>                     | Specifies the insertion of a CIL when generating the outgoing fax          |
+| <HighRes>                    | Indicates the resolution                                                   |
+| <Minor>                      | This syntax element returns an additional error code in the Response-TDD   |
+| <Originator>                 | Specifies the communications address of the originator                     |
+| <PollPassword>               | Specifies the password for polling remote device                           |
+| <PollSelector>               | Gives a handle to the recipient in order to poll for a specific document   |
+| <PollSubFunction>            | Specifies the subfunction of the Poll <ExtendTDD>                          |
+| <Recipient>, <RecipientSpec> | Specifies the communications address(es) of the recipient(s)               |
+| <SubAddress>                 | Specifies the Originator's sub-address                                     |
+| <To>                         | Transmission should finish on page number specified                        |
+| <Type>                       | Specifies the Transmission Format used                                     |
+| <UseEcm>                     | ECM is desired (input) or was activated (output)                           |
+| <Warning>                    | This syntax element returns an additional warning code in the Response-TDD |
+
+##### **11.2.2.2 Type-id-parameter**
+
+The Type-id-parameter is encoded as STRING set to one of the following values:
+
+- "STD" Basic Telefax G3 Service (MH)
+- "BTM" Telematic File Transfer (TFT) of Telefax G3 Service: Basic Transparent Mode
+- "DTM" Telematic File Transfer (TFT) of Telefax G3 Service: Document Transparent Mode
+- "EDI" Telematic File Transfer (TFT) of Telefax G3 Service: Edifact
+- "BFT" Telefax G3 Service: Binary File Transfer
+
+NOTE – The Transmission Format STD (=Modified Huffman Code, MH) is defined per ITU-T Recommendation T.4, the TFT formats BTM, DTM and EDI are defined per ITU-T Recommendation T.571 and T.30 (Annexes) and the Transmission Format BFT is defined per ITU-T Recommendation T.434.
+
+*Syntax:*
+
+<Type-id-parameter> := "STD" | "BTM" | "DTM" | "BFT" | "EDI"
+
+TABLE 65/T.611
+
+##### **Text Based Encoding of additional syntax elements for Telefax Group 3** (A ↵ denotes the new line format effector)
+
+| Syntax Element    | Keyword/Parameter Pair                     |
+|-------------------|--------------------------------------------|
+| <Convert>         | "CONVERT" ":" <Convert-id-parameter> ↵     |
+| <CvFax3>          | "CVFAX3" ":" <Convert-id-parameter> ↵      |
+| <Document>        | "FILENAME" ":" <File-parameter> ↵          |
+| <DocumentSpec>    | "FILENAME" ":" "@" <File-of-filespec> ↵    |
+| <DoPoll>          | "DOPOLL" ":" <Boolean-parameter> ↵         |
+| <From>            | "FROM" ":" NUMERIC-STRING ↵                |
+| <G3Speed>         | "G3SPEED" ":" <G3-speed-parameter> ↵       |
+| <GenCil>          | "GENCIL" ":" <Boolean-parameter> ↵         |
+| <HighRes>         | "HIGHRES" ":" <Resolution-parameter> ↵     |
+| <Minor>           | "MINOR" ":" <Error-parameter> ↵            |
+| <Originator>      | "ADDRESS" ":" <Address-parameter> ↵        |
+| <PollPassword>    | "PASSWORD" ":" <Password-parameter> ↵      |
+| <PollSelector>    | "POLLSELECT" ":" <Poll-select-parameter> ↵ |
+| <PollSubFunction> | "SUBFUNC" ":" "Poll" ↵                     |
+| <Recipient>       | "ADDRESS" ":" <Address-parameter> ↵        |
+| <RecipientSpec>   | "ADDRESS" ":" "@" <File-of-addrspec> ↵     |
+| <SubAddress>      | "SUBADDR" ":" <Sub-address-parameter> ↵    |
+| <To>              | "TO" ":" NUMERIC-STRING ↵                  |
+| <Type>            | "TYPE" ":" <Type-id-parameter> ↵           |
+| <UseEcm>          | "USEECM" ":" <Boolean-parameter> ↵         |
+| <Warning>         | "WARNING" ":" <Error-parameter> ↵          |
+
+##### 11.2.2.3 Convert-id-parameter
+
+The Convert-id-parameter is encoded as STRING set to one of the following values:
+
+|            |                                                                       |
+|------------|-----------------------------------------------------------------------|
+| "ASCII"    | APPLI/COM Extended ASCII (For outgoing files only)                    |
+| "ASCII437" | APPLI/COM Extended ASCII (For outgoing files only)                    |
+| "T.50"     | APPLI/COM Standard ASCII (For outgoing files only)                    |
+| "TIFF"     | TIFF Transfer Format as defined in 8.3                                |
+| "TIFF2"    | (For incoming files only). APPLI/COM TIFF Class 2 as specified in 8.3 |
+| "TIFF3"    | (For incoming files only). APPLI/COM TIFF Class 3 as specified in 8.3 |
+| "VOID"     | No conversion to be done                                              |
+
+NOTE – If a LA requests a Telefax document that has been received, it is possible to:
+
+- obtain the document in APPLI/COM TIFF class 2 by specifying TIFF2;
+- obtain the document in APPLI/COM TIFF class 3 by specifying TIFF3,
+
+provided the CA is capable of generating that special TIFF format. If only TIFF is specified, the document will be delivered in the APPLI/COM TIFF default class (class 1). However, in the send direction it is sufficient to specify TIFF only (without number extension), since the compression information is contained in the Transfer Format itself.
+
+The use of the Convert-id-parameter also depends on the Type-id selected. Table 66 depicts this.
+
+TABLE 66/T.611
+
+###### **Permitted Convert-id assignments dependent on Type-id and traffic direction**
+
+| Type-id                                                                                                                                                                                                 | Convert-id for outgoing traffic            | Convert-id for incoming traffic |
+|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------|---------------------------------|
+| STD                                                                                                                                                                                                     | ASCII, ASCIIxxx <sup>a)</sup> , T.50, TIFF | TIFF, TIFFx <sup>b)</sup>       |
+| BTM, DTM, BFT, EDI                                                                                                                                                                                      | VOID                                       |                                 |
+| <sup>a)</sup> xxx stands for a code-page, declared in the ICE, e.g. ASCII437 if code-page 437 has been declared.<br><sup>b)</sup> x stands for the TIFF class to be read, which is a value between 2.3. |                                            |                                 |
+
+*Syntax:*
+
+```
+
+<Convert-id-parameter> :=      <Convert-std> | <Convert-bin>
+
+<Convert-std> :=                <Convert-std-in> | <Convert-std-out>
+
+<Convert-std-in> :=             "TIFF" | "TIFF2" | "TIFF3"
+                                -- incoming documents
+
+<Convert-std-out> :=            <Ascii> | "T.50" | "TIFF"
+                                -- outgoing documents
+
+<Ascii> :=                      "ASCII" | STRING ("ASCII" + <Code-page>)
+
+<Code-page> :=                  <digit> <digit> <digit>
+
+<digit> :=                      "0" | ... | "9"
+
+<Convert-bin> :=                "VOID"
+
+```
+
+##### 11.2.2.4 File-of-addrspec and Address-parameter
+
+The File-of-addrspec parameter is encoded as PATH which points to a file containing Addrspec-parameters, which contain the Address-parameter.
+
+The Address-parameter is encoded as STRING. The STRING shall contain the telephone number. If the phone number starts with a "!" then it may contain special characters that are treated as operators (or modifiers) rather than dial digits, as shown in Table 67 below.
+
+The telephone number may be terminated by a "#" character (number sign) and may be followed by a subaddress (subaddress of the remote equipment). The encoding of the subaddress is defined in 11.2.2.7.
+
+Alternatively an alias name may be given instead of the phone number, provided the alias is introduced with a "&" character. It is assumed that the CA knows how to decode the alias specified. This is typically used when the CA implements a phone book.
+
+TABLE 67/T.611
+
+###### **Dial string modifiers for the PSTN**
+
+| Input                                                                                  | Type       | Explanation                                                                                                                                                                 |
+|----------------------------------------------------------------------------------------|------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| "0"   ...   "9"   "*"   "#"                                                            | Dial digit | Dial without interpretation                                                                                                                                                 |
+| "!"                                                                                    | Modifier   | First character in the dialling sequence string: enter the "raw dialling mode"                                                                                              |
+| ";"                                                                                    | Modifier   | Pause in the dialling process. Duration is CA dependent. Note that the ";" must be escaped by the "\" character, otherwise the CA may understand it as a comment introducer |
+| ":"                                                                                    | Modifier   | Same as ";" but does not need to be escaped                                                                                                                                 |
+| ,                                                                                      | Modifier   | Pause dialling for 2 seconds                                                                                                                                                |
+| "T"   "t"                                                                              | Modifier   | Enforce "tone" dialling for subsequent digits                                                                                                                               |
+| "P"   "p"                                                                              | Modifier   | Enforce "pulse" dialling for subsequent digits                                                                                                                              |
+| "W"   "w"                                                                              | Modifier   | CA waits and listens for a 3-seconds, continuous dial tone                                                                                                                  |
+| "@"                                                                                    | Modifier   | CA listens for remote ringing signal followed by a 5-seconds silence. If remote answer is not detected, CA responds as defaulted                                            |
+| NOTE – The dial string modifiers may be subject to national administration agreements. |            |                                                                                                                                                                             |
+
+###### *Syntax:*
+
+|                         |                                                                                                                                                        |
+|-------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------|
+| <File-of-addrspec> :=   | PATH<br>-- The path points to a file containing one or more<br>-- <Addrspec-parameter>s                                                                |
+| <Addrspec-parameter> := | <Address-parameter><br>["," <Cover-path> "," <Cover-conv> ["," [<Cover-type>] ["," <Nopgbrk>]]]                                                        |
+| <Address-parameter> :=  | (<Phone-number> ["#" <Subaddress>])  <br>("!" <Dial-command> ["#" <Subaddress>])  <br>("&" <Alias>)<br>-- contains telephone dialing sequence or alias |
+| <Phone-number> :=       | NUMERIC-STRING                                                                                                                                         |
+| <Dial-command> :=       | <Dial-operator> {<Dial-operator>}                                                                                                                      |
+| <Dial-operator> :=      | "0"   ...   "9"   "*"   "#"   ";"   ":"   ","   "T"   "t"   "P"   "p"   "W"   "w"   "@"                                                                |
+| <Subaddress> :=         | <Subaddress-parameter><br>-- see 11.2.2.7                                                                                                              |
+| <Alias> :=              | STRING                                                                                                                                                 |
+| <Cover-path> :=         | PATH<br>-- Path to a file containing a cover page for specific addressee                                                                               |
+
+<Cover-conv> := <Convert-id-parameter>  
+                   -- *Specifies the Transfer Format of the cover page file*
+
+<Cover-type> := <Type-id-parameter>  
+                   -- *Specifies the Transmission Format of the cover page*
+
+<Nopgbrk> := <Boolean-parameter>  
+                   -- *If set to true ("Yes") then no page break will occur between the cover*  
+                   -- *page and the main document*
+
+##### 11.2.2.5 File-of-filespec and File-parameter
+
+The File-of-filespec parameter is encoded as PATH which points to a file containing Filespec-parameters, which contain the File-parameter. The File-parameter itself is also encoded as PATH, which points to the file transferred.
+
+*Syntax:*
+
+<File-of-filespec> := PATH  
+                   -- *The path points to a file containing one or more*  
+                   -- *<Filespec-parameter>s*
+
+<Filespec-parameter> := <File-parameter> "," <File-conv> ["," <File-type>]
+
+<File-parameter> := PATH  
+                   -- *Path to the file transferred*
+
+<File-conv> := <Convert-id-parameter>  
+                   -- *Specifies the Transfer Format of the file.*
+
+<File-type> := <Type-id-parameter>  
+                   -- *Specifies the Transmission Format of the file*
+
+##### 11.2.2.6 G3-speed-parameter
+
+The G3-speed-parameter is encoded as NUMERIC-STRING set to one of the following values:
+
+"2400" 2400 bits per second  
+ "4800" 4800 bits per second  
+ "7200" 7200 bits per second  
+ "9600" 9600 bits per second  
+ "12200" 12200 bits per second  
+ "14400" 14400 bits per second
+
+*Syntax:*
+
+<G3-speed-parameter> := "2400" | "4800" | "7200" | "9600" | "12200" | "14400"
+
+##### 11.2.2.7 Sub-address-parameter
+
+The Sub-address-parameter is encoded as STRING that represents a sub-address. As defined per ITU-T Recommendation T.30 (1994) the STRING is restricted to digits ("0".."9") and the characters "+" and "-". The "\_" (underline) character shall be translated into a IRA space character (20<sub>HEX</sub>) by the CA. The length of the Sub-address-parameter is restricted to 20 octets.
+
+*Syntax:*
+
+<Sub-address-parameter> := <Subaddress-digit> {<Subaddress-digit>}
+
+<Subaddress-digit> := "0" | ... | "9" | "\*" | "#"  
+                   -- *the length of the <Sub-address-parameter> is restricted to 20 octets.*
+
+##### 11.2.2.8 Resolution-parameter
+
+The Resolution-parameter is encoded as NUMERIC-STRING set to one of the following values:
+
+|     |                                                                          |
+|-----|--------------------------------------------------------------------------|
+| "0" | 8 pels per mm horizontal, 3,85 lines per mm vertical (98 dpi vertical)   |
+| "1" | 8 pels per mm horizontal, 7,7 lines per mm vertical (196 dpi vertical)   |
+| "2" | 200 dpi horizontal, 200 dpi vertical (200 dpi)                           |
+| "3" | 300 dpi horizontal, 300 dpi vertical (300 dpi)                           |
+| "4" | 400 dpi horizontal, 300 dpi vertical (400 dpi)                           |
+| "5" | 8 pels per mm horizontal, 15,4 lines per mm vertical (392 dpi vertical)  |
+| "6" | 16 pels per mm horizontal, 15,4 lines per mm vertical (392 dpi vertical) |
+
+*Syntax:*
+
+<Resolution-parameter> := "0" | ... | "6"
+
+##### 11.2.2.9 Password-parameter
+
+The Password-parameter is encoded as STRING. As defined per ITU-T Recommendation T.30 (1994) the character-set of the STRING is restricted to digits ("0".."9") and the characters "+" and "-". The "\_" (underline) character shall be translated into a IRA space character (20<sub>HEX</sub>) by the CA.
+
+*Syntax:*
+
+<Password-parameter> := <Password-digit> {<Password-digit>}
+
+<Password-digit> := "0" | ... | "9" | "\*" | "#"  
+*-- the length of the <Password-parameter> is restricted to 20 octets.*
+
+##### 11.2.2.10 Poll-select-parameter
+
+The Poll-select-parameter is encoded as STRING. As defined per ITU-T Recommendation T.30 (1994) the character-set of the STRING is restricted to digits ("0".."9") and the characters "+" and "-". The "\_" (underline) character shall be translated into a IRA space character (20<sub>HEX</sub>) by the CA.
+
+*Syntax:*
+
+<Poll-select-parameter> := <Poll-select-digit> {<Poll-select-digit>}
+
+<Poll-select-digit> := "0" | ... | "9" | "\*" | "#"  
+*-- the length of the <Poll-select-parameter> is restricted to 20 octets.*
+
+### 11.3 Additional Functionality
+
+#### 11.3.1 Function: Send and SendAck
+
+See Tables 68 and 69.
+
+#### 11.3.2 Function: Receive
+
+See Table 70.
+
+#### 11.3.3 Function: Poll
+
+This extension consists in giving a LA the ability to retrieve a series of documents posted by a remote fax device.
+
+For instance, if user "John" sends documents to remote fax "Tom", and "Tom" has posted documents to be retrieved by "John", the "Polling" extension allows "John" to receive the documents from "Tom" in the same communication session.
+
+The <ExtendTDD>, expanded with the <PollExtension> is used to specifically retrieve the documents posted by the remote device (see Table 71).
+
+TABLE 68/T.611
+
+##### **Additional functionality of the <SendTDD> for Telefax Group 3**
+
+| Syntax Element                 | C | T | I/O | Text Based Encoding |                         |                         | Comment                                                                                                          |
+|--------------------------------|---|---|-----|---------------------|-------------------------|-------------------------|------------------------------------------------------------------------------------------------------------------|
+|                                |   |   |     | Keyword             | Parameter               | Default                 |                                                                                                                  |
+| <G3Speed>                      | B | o | I   | G3SPEED             | <G3-speed-parameter>    | Highest speed available | Modulation speed. If the CA cannot return the modulation speed used, it shall blank the field                    |
+| <GenCil>                       | + | o | I   | GENCIL              | <Boolean-parameter>     | "Yes"                   | Asks the CA to generate a CIL in the transmitted file                                                            |
+| <HighRes>                      | + | o | I   | HIGHRES             | <Resolution-parameter>  | "0"                     | Enforces higher resolution when set to values greater than "0". See also 11.2.2.8                                |
+| <SubAddress>                   | + | o | I   | SUBADDR             | <Sub-address-parameter> | –                       | Originator's sub-address                                                                                         |
+| <UseEcm>                       | + | o | I   | USEECM              | <Boolean-parameter>     | "Yes"                   | States whether Error Correction Mode shall be used                                                               |
+| Send to one addressee          |   |   |     |                     |                         |                         |                                                                                                                  |
+| <Recipient>                    | B | m | I   | ADDRESS             | <Address-parameter>     | –                       | Specifies one recipient's call number                                                                            |
+| <DoPoll>                       | + | o | I   | DOPOLL              | <Boolean-parameter>     | "No"                    | If "Yes" receiver is polled for sending a document                                                               |
+| <PollPassword>                 | + | o | I   | PASSWORD            | <Password-parameter>    | –                       |                                                                                                                  |
+| <PollSelector>                 | + | o | I   | SELECT              | <Poll-select-parameter> | –                       |                                                                                                                  |
+| Send to one or many addressees |   |   |     |                     |                         |                         |                                                                                                                  |
+| <RecipientSpec>                | + | m | I   | ADDRESS             | "@" <File-of-addrspec>  | –                       | Specifies a list of recipients                                                                                   |
+| Send only one file             |   |   |     |                     |                         |                         |                                                                                                                  |
+| <Convert>                      | B | m | I   | CONVERT             | <Convert-id-parameter>  | –                       | States the Transfer Format of the outgoing file                                                                  |
+| <Document>                     | B | m | I   | FILENAME            | <File-parameter>        | –                       | The single outgoing file to be transmitted, delivered under the Transfer Format specified by the Convert keyword |
+| <Type>                         | B | o | I   | TYPE                | <Type-id-parameter>     | "STD"                   | Specifies the document type to be sent                                                                           |
+| <From>                         | + | o | I   | FROM                | NUMERIC-STRING          | First page              | The first page to be actually sent; does only apply to text files                                                |
+| <To>                           | + | o | I   | TO                  | NUMERIC-STRING          | Last page               | The last page to be actually sent; does only apply to text files                                                 |
+| Send one or many files         |   |   |     |                     |                         |                         |                                                                                                                  |
+| <DocumentSpec>                 | + | m | I   | FILENAME            | "@" <File-of-filespec>  | –                       | Specifies a list of files; uses a special syntax                                                                 |
+
+TABLE 69/T.611
+
+##### **Additional functionality of the <SendAckTDD> for Telefax Group 3**
+
+| Syntax Element         | C | T | I/O | Text Based Encoding |                         |                         | Comment                                                                                                          |
+|------------------------|---|---|-----|---------------------|-------------------------|-------------------------|------------------------------------------------------------------------------------------------------------------|
+|                        |   |   |     | Keyword             | Parameter               | Default                 |                                                                                                                  |
+| <Recipient>            | B | m | I/O | ADDRESS             | <Address-parameter>     | –                       | Specifies one recipient's call number                                                                            |
+| <G3Speed>              | B | o | I/O | G3SPEED             | <G3-speed-parameter>    | Highest speed available | Modulation speed. If the CA cannot return the modulation speed used, it shall blank the field                    |
+| <GenCil>               | + | o | I   | GENCIL              | <Boolean-parameter>     | "Yes"                   | Asks the CA to generate a CIL in the transmitted file                                                            |
+| <HighRes>              | + | o | I   | HIGHRES             | <Resolution-parameter>  | "0"                     | Enforces higher resolution when set to values greater than "0". See also 11.2.2.8                                |
+| <SubAddress>           | + | o | I   | SUBADDR             | <Sub-address-parameter> | –                       | Originator's sub-address                                                                                         |
+| <UseEcm>               | + | o | I/O | USEECM              | <Boolean-parameter>     | "Yes"                   | States whether Error Correction Mode shall be used                                                               |
+| <DoPoll>               | + | o | I   | DOPOLL              | <Boolean-parameter>     | "No"                    | if "Yes" receiver is polled for sending a document                                                               |
+| <PollPassword>         | + | o | I   | PASSWORD            | <Password-parameter>    | –                       |                                                                                                                  |
+| <PollSelector>         | + | o | I   | SELECT              | <Poll-select-parameter> | –                       |                                                                                                                  |
+| Send only one file     |   |   |     |                     |                         |                         |                                                                                                                  |
+| <Convert>              | B | m | I   | CONVERT             | <Convert-id-parameter>  | –                       | States the Transfer Format of the outgoing file                                                                  |
+| <Document>             | B | m | I   | FILENAME            | <File-parameter>        | –                       | The single outgoing file to be transmitted, delivered under the Transfer Format specified by the Convert keyword |
+| <Type>                 | B | o | I   | TYPE                | <Type-id-parameter>     | "STD"                   | Specifies the document type to be sent                                                                           |
+| <From>                 | + | o | I   | FROM                | NUMERIC-STRING          | First page              | The first page to be actually sent; does only apply to text files                                                |
+| <To>                   | + | o | I   | TO                  | NUMERIC-STRING          | Last page               | The last page to be actually sent; does only apply to text files                                                 |
+| Send one or many files |   |   |     |                     |                         |                         |                                                                                                                  |
+| <DocumentSpec>         | + | m | I   | FILENAME            | "@" <File-of-filespec>  | –                       | Specifies a list of files; uses a special syntax                                                                 |
+
+TABLE 70/T.611
+
+##### **Additional functionality of the <ReceiveTDD> for Telefax Group 3**
+
+| Syntax Element         | C | T | I/O | Text Based Encoding |                         |         | Comment                                                                                                                                                                                |
+|------------------------|---|---|-----|---------------------|-------------------------|---------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+|                        |   |   |     | Keyword             | Parameter               | Default |                                                                                                                                                                                        |
+| <CvFax3>               | B | o | I   | CVFAX3              | <Convert-id-parameter>  | "TIFF"  | Transfer format desired by the LA                                                                                                                                                      |
+| <Originator>           | B | o | O   | ADDRESS             | <Address-parameter>     | –       | Specifies originator's phone number                                                                                                                                                    |
+| <G3Speed>              | + | o | O   | G3SPEED             | <G3-speed-parameter>    | –       | Modulation speed. If the CA cannot return the modulation speed used, field will be left empty                                                                                          |
+| <SubAddress>           | + | o | I/O | SUBADDR             | <Sub-address-parameter> | –       | Recipient's sub-address; if specified in the Request, used as a selector for the retrieval                                                                                             |
+| Only one file received |   |   |     |                     |                         |         |                                                                                                                                                                                        |
+| <Convert>              | B | m | O   | CONVERT             | <Convert-id-parameter>  | –       | States the Transfer Format of the received file                                                                                                                                        |
+| <Document>             | B | m | I/O | FILENAME            | <File-parameter>        | –       | The filename may be pre-set by the LA on request. If only one file is received, the name shall be retained by the CA. If many files are received the name may be overwritten by the CA |
+| <Type>                 | B | o | O   | TYPE                | <Type-id-parameter>     | –       | Specifies the document type received                                                                                                                                                   |
+| Many files received    |   |   |     |                     |                         |         |                                                                                                                                                                                        |
+| <DocumentSpec>         | + | m | O   | FILENAME            | "@" <File-of-filespec>  | –       | Specifies a list of files; uses a special syntax                                                                                                                                       |
+
+### **11.4 CA-Descriptor Settings**
+
+A CA supporting the FX3 service shall specify the supported Type-IDs (Transmission Formats) in the CA-Descriptor (see 9.5)
+
+For support of the Poll TDD, the EXTEND keyword of the CA-Descriptor has to be set accordingly. Table 72 depicts this.
+
+TABLE 71/T.611
+
+#### **Syntax elements of <PollExtension> for Telefax Group 3**
+
+| Syntax Element    | C | T | I/O | Text Based Encoding |                         |             | Comment                                                     |
+|-------------------|---|---|-----|---------------------|-------------------------|-------------|-------------------------------------------------------------|
+|                   |   |   |     | Keyword             | Parameter               | Default     |                                                             |
+| <PollSubFunction> | B | m | I   | SUBFUNC             | "Poll"                  | –           | CA shall generate a response                                |
+| <Recipient>       | B | m | I   | ADDRESS             | <Address-parameter>     | –           | Specifies one recipient's call number                       |
+| <PollPassword>    | B | m | I   | PASSWORD            | <Password-parameter>    | –           |                                                             |
+| <PollSelector>    | B | o | I   | SELECT              | <Poll-select-parameter> |             |                                                             |
+| <SendTime>        | B | o | I   | SENDTIME            | <Send-time-parameter>   | "IMMEDIATE" | CA shall actually process the request at the time specified |
+| <ComId>           | B | o | O   | COMID               | <Com-id-parameter>      | –           | Identification of the communication (computed by the CA)    |
+
+TABLE 72/T.611
+
+#### **Additional CA-Descriptor settings for Telefax Group 3**
+
+| Keyword | Parameter | CA declares that                            |
+|---------|-----------|---------------------------------------------|
+| FX3     | "STD"     | the Basic Telefax service (MH) is supported |
+| FX3     | "BTM"     | Basic Transparent Mode is supported         |
+| FX3     | "DTM"     | Document Transparent Mode is supported      |
+| FX3     | "BFT"     | Binary File Transfer is supported           |
+| FX3     | "EDI"     | Electronic Data Interchange is supported    |
+| EXTEND  | "Poll"    | the Poll functionality is supported         |
+
+## 12 Service: Telefax Group 4
+
+### 12.1 Service Specific Syntax Elements
+
+<ServiceDependentKeywordsSend> :=  
+(<Recipient> | <RecipientSpec>)  
+(((<Document> <Convert> [<Type>] [<Name>] [<UserInfo>] [<Prolog>] [From]  
+[To]) | <DocumentSpec>) [<SubAddress>] [<HighRes>])
+
+<ServiceDependentKeywordsSendAck> :=  
+<Recipient>  
+(((<Document> <Convert> [<Type>] [<Name>] [<UserInfo>] [<Prolog>] [<Cil>]  
+[From] [To]) | <DocumentSpec>) [<SubAddress>] [<HighRes>])
+
+<ServiceDependentKeywordsReceive> :=  
+[<Originator>]  
+(((<Document> <Convert> <Type> [<Name>] [<UserInfo>] [<Prolog>] [<Cil>]  
+[<FirstPg>]) | <DocumentSpec>) [<CvFax4>] [<SubAddress>])
+
+See Table 73.
+
+TABLE 73/T.611
+
+#### Additional syntax elements for Telefax Group 4
+
+| Syntax Element               | Purpose                                                                                                                                           |
+|------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------|
+| <Cil>                        | Specifies the contents of the Call Identification Line as defined per ITU-T Recommendation F.200. See also G.1                                    |
+| <Convert>                    | Specifies the Transfer Format to be used                                                                                                          |
+| <CvFax4>                     | Specifies the desired Transfer Format for received files                                                                                          |
+| <Document>, <DocumentSpec>   | Specifies the document or the documents to be sent or being received                                                                              |
+| <FirstPg>                    | Specifies the number of the first received page                                                                                                   |
+| <From>                       | Transmission should start from the page number specified                                                                                          |
+| <HighRes>                    | Indicates the resolution                                                                                                                          |
+| <Name>                       | Assigns a name to the document to be sent or indicates the name of the received document as defined per ITU-T Recommendation T.571                |
+| <Originator>                 | Specifies the communications address of the originator                                                                                            |
+| <Prolog>                     | Path to the "prolog" document. This is a document, coded according to ITU Recommendation T.61, which is prepended to the main document to be sent |
+| <Recipient>, <RecipientSpec> | Specifies the communications address(es) of the recipient(s)                                                                                      |
+| <SubAddress>                 | Specifies the Originator's sub-address                                                                                                            |
+| <To>                         | Transmission should finish on page number specified                                                                                               |
+| <Type>                       | Specifies the Transmission Format used                                                                                                            |
+| <UserInfo>                   | Specifies a comment attached to the document to be sent/received. The comment is transmitted via the telecommunications service                   |
+
+### 12.2 Text Based Encoding
+
+#### 12.2.1 Mapping of Keywords
+
+See Table 74.
+
+TABLE 74/T.611  
+Text Based Encoding of additional syntax elements for Telefax Group 4  
+(A ↵ denotes the new line format effector)
+
+| Syntax Element  | Keyword/Parameter Pair                  |
+|-----------------|-----------------------------------------|
+| <Cil>           | "CIL" ":" <Cil-parameter> ↵             |
+| <Convert>       | "CONVERT" ":" <Convert-id-parameter> ↵  |
+| <CvFax4>        | "CVFAX4" ":" <Convert-id-parameter> ↵   |
+| <Document>      | "FILENAME" ":" <File-parameter> ↵       |
+| <DocumentSpec>  | "FILENAME" ":" "@" <File-of-filespec> ↵ |
+| <FirstPg>       | "FIRSTPG" ":" NUMERIC-STRING ↵          |
+| <From>          | "FROM" ":" NUMERIC-STRING ↵             |
+| <HighRes>       | "HIGHRES" ":" <Resolution-parameter> ↵  |
+| <Name>          | "NAME" ":" STRING (SIZE(1..12)) ↵       |
+| <Originator>    | "ADDRESS" ":" <Address-parameter> ↵     |
+| <Prolog>        | "PROLOG" ":" <Path-parameter> ↵         |
+| <Recipient>     | "ADDRESS" ":" <Address-parameter> ↵     |
+| <RecipientSpec> | "ADDRESS" ":" "@" <File-of-addrspec> ↵  |
+| <SubAddress>    | "SUBADDR" ":" <Sub-address-parameter> ↵ |
+| <To>            | "TO" ":" NUMERIC-STRING ↵               |
+| <Type>          | "TYPE" ":" <Type-id-parameter> ↵        |
+| <UserInfo>      | "USERINFO" ":" STRING (SIZE(1..12)) ↵   |
+
+#### 12.2.2 Encoding of Parameters
+
+See also 6.4.4 for the encoding of non service dependent parameters used.
+
+##### 12.2.2.1 Service-id-parameter
+
+The Service-id parameter is encoded as STRING set to the constant value "FX4".
+
+*Syntax:*
+
+<Service-id-parameter> := "FX4"
+
+##### 12.2.2.2 Type-id-parameter
+
+The Type-id-parameter is encoded as STRING set to one of the following values:
+
+|       |                                                                                |
+|-------|--------------------------------------------------------------------------------|
+| "STD" | Basic Telefax G4 Service (MR)                                                  |
+| "DTM" | Telematic File Transfer (TFT) of Telefax G4 Service: Document Transparent Mode |
+| "EDI" | Telematic File Transfer (TFT) of Telefax G4 Service: Edifact                   |
+| "BFT" | Telefax G4 Service: Binary File Transfer                                       |
+
+NOTE – The Transmission Format STD (=Modified Read Code, MR) is defined per ITU-T Recommendation T.6, the TFT formats DTM and EDI are defined per ITU-T Recommendation T.571 and the Transmission Format BFT is defined per ITU-T Recommendation T.434.
+
+*Syntax:*
+
+<Type-id-parameter> := "STD" | "DTM" | "BFT" | "EDI"
+
+##### 12.2.2.3 Convert-id-parameter
+
+The Convert-id-parameter is encoded as STRING set to one of the following values:
+
+|            |                                                                       |
+|------------|-----------------------------------------------------------------------|
+| "ASCII"    | APPLI/COM Extended ASCII (For outgoing files only)                    |
+| "ASCII437" | APPLI/COM Extended ASCII (For outgoing files only)                    |
+| "T.50"     | APPLI/COM Standard ASCII (For outgoing files only)                    |
+| "T.61"     | APPLI/COM Transfer Format T.61                                        |
+| "TIFF"     | TIFF Transfer Format as defined in 8.3                                |
+| "TIFF2"    | (For incoming files only). APPLI/COM TIFF Class 2 as specified in 8.3 |
+| "TIFF4"    | (For incoming files only). APPLI/COM TIFF Class 4 as specified in 8.3 |
+| "VOID"     | No conversion to be done                                              |
+
+NOTE – If a LA requests a Telefax document that has been received, it is possible to:
+
+- obtain the document in APPLI/COM TIFF class 2 by specifying TIFF2;
+- obtain the document in APPLI/COM TIFF class 4 by specifying TIFF4,
+
+provided the CA is capable of generating that special TIFF format. If only TIFF is specified, the document will be delivered in the APPLI/COM TIFF default class (class 1). However, in the send direction it is sufficient to specify TIFF only (without number extension), since the compression information is contained in the Transfer Format itself.
+
+The use of the Convert-id-parameter also depends on the Type-ID selected. Table 75 depicts this.
+
+TABLE 75/T.611
+
+###### Permitted Convert-id assignments dependent on Type-id and traffic direction
+
+| Type-id                                                                                                                                                                                                                     | Convert-id for outgoing traffic            | Convert-id for incoming traffic |
+|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------|---------------------------------|
+| STD                                                                                                                                                                                                                         | ASCII, ASCIIxxx <sup>a)</sup> , T.50, TIFF | TIFF, TIFFx <sup>b)</sup>       |
+| DTM, BFT, EDI                                                                                                                                                                                                               | VOID                                       |                                 |
+| <p><sup>a)</sup> xxx stands for a code-page, declared in the ICE, e.g. ASCII437 if code-page 437 has been declared.</p> <p><sup>b)</sup> x stands for the TIFF class to be read, the possible values are either 2 or 4.</p> |                                            |                                 |
+
+*Syntax:*
+
+```
+<Convert-id-parameter> :=      <Convert-std> | <Convert-bin> | <Convert-txt>
+
+<Convert-std> :=                <Convert-std-in> | <Convert-std-out>
+
+<Convert-std-in> :=             "TIFF" | "TIFF2" | "TIFF4"
+                                -- incoming documents
+
+<Convert-std-out> :=            <Ascii> | "T.50" | "TIFF"
+                                -- outgoing documents
+
+<Convert-txt> :=                <Ascii> | "T.50" | "T.61"
+
+<Ascii> :=                      "ASCII" | STRING ("ASCII" + <Code-page>)
+
+<Code-page> :=                  <digit> <digit> <digit>
+
+<digit> :=                      "0" | ... | "9"
+
+<Convert-bin> :=                "VOID"
+```
+
+##### 12.2.2.4 File-of-addrspec and Address-parameter
+
+The File-of-addrspec parameter is encoded as PATH which points to a file containing Addr-spec-parameters, which contain the Address-parameter.
+
+The Address-parameter is encoded as STRING. The STRING consists of the recipient's terminal identifier as defined per ITU-T Recommendation F.184. The mnemonic part of the terminal identifier may be omitted or specified as a question mark ("?"), in which case no verification of the subscriber's address is performed. See also Annex G.2.
+
+Alternatively an alias name may be given instead of the terminal identifier, provided the alias is introduced with a "&" character. It is assumed that the CA knows how to decode the alias specified. Typical use of this feature is when the CA implements a phone book.
+
+*Syntax:*
+
+```
+<File-of-addrspec> :=          PATH
+                                -- The path points to a file containing one or more
+                                -- <Addr-spec-parameter>s
+
+<Addr-spec-parameter> :=       <Address-parameter>
+                                ["," <Cover-path> "," <Cover-conv> ["," [<Cover-type>] ["," <Nopgbrk>]]]
+
+<Address-parameter> :=         <Terminal-id> | ("&" <Alias>)
+
+<Terminal-id> :=               STRING
+                                -- The string shall present the terminal-id as defined per
+                                -- ITU-T Recommendation F.184
+
+<Alias> :=                     STRING
+
+<Cover-path> :=                PATH
+                                -- Path to a file containing a cover page for specific addressee
+
+<Cover-conv> :=                <Convert-id-parameter>
+                                -- Specifies the Transfer Format of the cover page file
+
+<Cover-type> :=                <Type-id-parameter>
+                                -- Specifies the Transmission Format of the cover page
+
+<Nopgbrk> :=                   <Boolean-parameter>
+                                -- If set to true ("Yes") then no page break will occur between the cover
+                                -- page and the main document
+```
+
+##### 12.2.2.5 File-of-filespec and File-parameter
+
+The File-of-filespec parameter is encoded as PATH which points to a file containing Filespec-parameters, which contain the File-parameter. The File-parameter itself is also encoded as PATH, which points to the file transferred.
+
+*Syntax:*
+
+```
+<File-of-filespec> :=          PATH
+                             -- The path points to a file containing one or more
+                             -- <Filespec-parameter>s
+
+<Filespec-parameter> :=      <File-parameter> "," <File-conv> ["," [<File-type>]
+                             ["," <Send-parameter> | <SendAck-parameter> | <Receive-parameter>] ]
+
+<Send-parameter> :=          [<File-name>] ["," <File-userinfo>]
+
+<SendAck-parameter> :=       [<File-name>] ["," [<File-userinfo>] ["," <File-cil>] ]
+
+<Receive-parameter> :=       [<File-name>] ["," [<File-userinfo>] ["," <File-cil>] ]
+
+<File-parameter> :=          PATH
+                             -- Path to the file transferred
+
+<File-conv> :=                <Convert-id-parameter>
+                             -- Specifies the Transfer Format of the file.
+
+<File-type> :=                <Type-id-parameter>
+                             -- Specifies the Transmission Format of the file
+
+<File-name> :=                STRING (SIZE(1..12))
+                             -- Specifies the name of the file to be transmitted
+
+<File-userinfo> :=            STRING (SIZE(1..12))
+                             -- Specifies additional user to user info to be transmitted
+
+<File-cil> :=                  Cil-parameter
+                             -- See 12.2.2.6 below.
+```
+
+##### 12.2.2.6 Cil-parameter
+
+A string of 72 characters as defined per ITU-T Recommendation F.200, composed as follows (see also G.1):
+
+|                                   |                                                 |
+|-----------------------------------|-------------------------------------------------|
+| Terminal identifier of recipient  | Length: 24 characters                           |
+| Separator                         | The character "/" (2F <sub>HEX</sub> )          |
+| Terminal identifier of originator | Length: 24 characters                           |
+| Separator                         | The character "/" (2F <sub>HEX</sub> )          |
+| Local date and time of originator | Length: 14 characters, format: "YY-MM-DD-HH:MM" |
+| Separator                         | The character "/" (2F <sub>HEX</sub> )          |
+| Reference information             | Length: 7 characters                            |
+
+*Syntax:*
+
+```
+<Cil-parameter> :=          <Recipient-tid> "/" <Originator-tid> "/" <Local-time> "/" <Ref-info>
+
+<Recipient-tid> :=           STRING (SIZE(24))
+                             -- The string presents the terminal-id as defined per
+                             -- ITU-T Recommendation F.184
+
+<Originator-tid> :=          STRING (SIZE(24))
+                             -- The string presents the terminal-id as defined per
+                             -- ITU-T Recommendation F.184
+
+<Local-time> :=              <Date-time-parameter>
+
+<Ref-info> :=                STRING (SIZE(7))
+```
+
+##### 12.2.2.7 Sub-address-parameter
+
+The Sub-address-parameter is encoded as NUMERIC-STRING that represents a sub-address.
+
+*Syntax:*
+
+<Sub-address-parameter> := NUMERIC-STRING (SIZE(1..4))
+
+##### 12.2.2.8 Resolution-parameter
+
+The Sub-address-parameter is encoded as NUMERIC-STRING set to one of the following values:
+
+|     |         |
+|-----|---------|
+| "0" | 200 dpi |
+| "1" | 240 dpi |
+| "2" | 300 dpi |
+| "3" | 400 dpi |
+| "4" | 400 dpi |
+
+*Syntax:*
+
+<Resolution-parameter> := "0" | ... | "4"
+
+### 12.3 Additional Functionality
+
+#### 12.3.1 Function: Send and SendAck
+
+See Tables 76 and 77.
+
+#### 12.3.2 Function: Receive
+
+See Table 78.
+
+### 12.4 CA-Descriptor Settings
+
+A CA supporting the FX4 service shall specify the supported Type-id (document Transmission Formats) in the CA-Descriptor (see 9.5) Table 79 below shows the possible assignments.
+
+## 13 Service: Teletex
+
+### 13.1 Service Specific Syntax Elements
+
+<ServiceDependentKeywordsSend> :=  
+    (<Recipient> | <RecipientSpec>)  
+    (((<Document> <Convert> [<Type>] [<Name>] [<UserInfo>] [<Prolog>] [From]  
+    [To] [T61Options]) | <DocumentSpec>) [<SubAddress>]
+
+<ServiceDependentKeywordsSendAck> :=  
+    <Recipient>  
+    (((<Document> <Convert> [<Type>] [<Name>] [<UserInfo>] [<Prolog>] [<Cil>]  
+    [From] [To] [T61Options]) | <DocumentSpec>) [<SubAddress>]
+
+<ServiceDependentKeywordsReceive> :=  
+    [<Originator>]  
+    (((<Document> <Convert> <Type> [<Name>] [<UserInfo>] [<Prolog>] [<Cil>]  
+    [<FirstPg>]) | <DocumentSpec>) [<CvTtx>] [<SubAddress>]
+
+See Table 80.
+
+TABLE 76/T.611
+
+#### **Additional functionality of the <SendTDD> for Telefax Group 4**
+
+| Syntax Element                 | C | T | I/O | Text Based Encoding |                         |            | Comment                                                                                                                                 |
+|--------------------------------|---|---|-----|---------------------|-------------------------|------------|-----------------------------------------------------------------------------------------------------------------------------------------|
+|                                |   |   |     | Keyword             | Parameter               | Default    |                                                                                                                                         |
+| <HighRes>                      | + | o | I   | HIGHRES             | <Resolution-parameter>  | "0"        | Enforces higher resolution when set to values greater than "0". See also 12.2.2.8                                                       |
+| <SubAddress>                   | + | o | I   | SUBADDR             | <Sub-address-parameter> | –          | Originator's sub-address                                                                                                                |
+| Send to one addressee          |   |   |     |                     |                         |            |                                                                                                                                         |
+| <Recipient>                    | B | m | I   | ADDRESS             | <Address-parameter>     | –          | Specifies one recipient's call number                                                                                                   |
+| Send to one or many addressees |   |   |     |                     |                         |            |                                                                                                                                         |
+| <RecipientSpec>                | + | m | I   | ADDRESS             | "@" <File-of-addrspec>  | –          | Specifies a list of recipients                                                                                                          |
+| Send only one file             |   |   |     |                     |                         |            |                                                                                                                                         |
+| <Convert>                      | B | m | I   | CONVERT             | <Convert-id-parameter>  | –          | States the Transfer Format of the outgoing file                                                                                         |
+| <Document>                     | B | m | I   | FILENAME            | <File-parameter>        | –          | The single outgoing file to be transmitted, delivered under the Transfer Format specified by the Convert keyword                        |
+| <Type>                         | B | o | I   | TYPE                | <Type-id-parameter>     | "STD"      | Specifies the document type to be sent                                                                                                  |
+| <Name>                         | + | o | I   | NAME                | STRING (SIZE(1..12))    | –          | Assigns a "name" to the files to be sent. 12 characters maximum. It corresponds to the filename parameter in TFT (see ITU-T Rec. T.571) |
+| <UserInfo>                     | + | o | I   | USERINFO            | STRING (SIZE(1..12))    | –          | Assigns a user comment to the document. This comment is transmitted with the document. 12 characters maximum                            |
+| <Prolog>                       | + | o | I   | PROLOG              | PATH                    | –          | Filename of the "control document" (full path)                                                                                          |
+| <From>                         | + | o | I   | FROM                | NUMERIC-STRING          | First page | The first page to be actually sent; does only apply to text files                                                                       |
+| <To>                           | + | o | I   | TO                  | NUMERIC-STRING          | Last page  | The last page to be actually sent; does only apply to text files                                                                        |
+| Send one or many files         |   |   |     |                     |                         |            |                                                                                                                                         |
+| <DocumentSpec>                 | + | m | I   | FILENAME            | "@" <File-of-filespec>  | –          | Specifies a list of files; uses a special syntax                                                                                        |
+
+TABLE 77/T.611
+
+#### Additional functionality of the <SendAckTDD> for Telefax Group 4
+
+| Syntax Element         | C | T | I/O | Text Based Encoding |                         |            | Comment                                                                                                       |
+|------------------------|---|---|-----|---------------------|-------------------------|------------|---------------------------------------------------------------------------------------------------------------|
+|                        |   |   |     | Keyword             | Parameter               | Default    |                                                                                                               |
+| <Recipient>            | B | m | I   | ADDRESS             | <Address-parameter>     | –          | Specifies one recipient's call number                                                                         |
+| <HighRes>              | + | o | I   | HIGHRES             | <Resolution-parameter>  | "0"        | Enforces higher resolution when set > "0". See 12.2.2.8                                                       |
+| <SubAddress>           | + | o | I   | SUBADDR             | <Sub-address-parameter> | –          | Originator's sub-address                                                                                      |
+| Send only one file     |   |   |     |                     |                         |            |                                                                                                               |
+| <Convert>              | B | m | I   | CONVERT             | <Convert-id-parameter>  | –          | Transfer format of the outgoing file                                                                          |
+| <Document>             | B | m | I   | FILENAME            | <File-parameter>        | –          | Single file to be transmitted, delivered under the Transfer Format specified by the Convert keyword           |
+| <Type>                 | B | o | I   | TYPE                | <Type-id-parameter>     | "STD"      | Specifies the document type to be sent                                                                        |
+| <Cil>                  | B | o | O   | CIL                 | <Cil-parameter>         | –          | Call identification line built by the CA (see ITU-T Rec. F.200)                                               |
+| <Name>                 | + | o | I   | NAME                | STRING (SIZE(1..12))    | –          | Assigns a "name" to the files to be sent. Corresponds to the filename parameter in TFT (see ITU-T Rec. T.571) |
+| <UserInfo>             | + | o | I   | USERINFO            | STRING (SIZE(1..12))    | –          | Assigns a user comment to the document. This comment is transmitted with the document                         |
+| <Prolog>               | + | o | I   | PROLOG              | PATH                    | –          | Filename of the "control document" (full path)                                                                |
+| <From>                 | + | o | I   | FROM                | NUMERIC-STRING          | First page | The first page to be actually sent; does only apply to text files                                             |
+| <To>                   | + | o | I   | TO                  | NUMERIC-STRING          | Last page  | The last page to be actually sent; does only apply to text files                                              |
+| Send one or many files |   |   |     |                     |                         |            |                                                                                                               |
+| <DocumentSpec>         | + | m | I   | FILENAME            | "@" <File-of-filespec>  | –          | Specifies a list of files; uses a special syntax                                                              |
+
+TABLE 78/T.611
+
+#### **Additional functionality of the <ReceiveTDD> for Telefax Group 4**
+
+| Syntax Element         | C | T | I/O | Text Based Encoding |                         |         | Comment                                                                                                                                                                                |
+|------------------------|---|---|-----|---------------------|-------------------------|---------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+|                        |   |   |     | Keyword             | Parameter               | Default |                                                                                                                                                                                        |
+| <Originator>           | B | o | O   | ADDRESS             | <Address-parameter>     | –       | Specifies originator's phone number                                                                                                                                                    |
+| <CvFax4>               | B | o | I   | CVFAX4              | <Convert-id-parameter>  | "TIFF"  | Transfer format desired by the LA                                                                                                                                                      |
+| <SubAddress>           | + | o | I/O | SUBADDR             | <Sub-address-parameter> | –       | Recipient's sub-address; if specified in the Request, used as a selector for the retrieval                                                                                             |
+| Only one file received |   |   |     |                     |                         |         |                                                                                                                                                                                        |
+| <Convert>              | B | m | O   | CONVERT             | <Convert-id-parameter>  | –       | States the Transfer Format of the received file                                                                                                                                        |
+| <Document>             | B | m | I/O | FILENAME            | <File-parameter>        | –       | The filename may be pre-set by the LA on request. If only one file is received, the name shall be retained by the CA. If many files are received the name may be overwritten by the CA |
+| <Type>                 | B | o | O   | TYPE                | <Type-id-parameter>     | –       | Specifies the document type received                                                                                                                                                   |
+| <Cil>                  | B | o | O   | CIL                 | <Cil-parameter>         | –       | Call identification line built by the CA (see ITU-T Rec. F.200)                                                                                                                        |
+| <Name>                 | + | o | O   | NAME                | STRING (SIZE(1..12))    | –       | Returns the name of the incoming file (12 characters maximum)                                                                                                                          |
+| <UserInfo>             | + | o | O   | USERINFO            | STRING (SIZE(1..12))    | –       | Assigns a user comment to the document. This comment is transmitted with the document. 12 characters maximum                                                                           |
+| <FirstPg>              | + | o | O   | FIRSTPG             | NUMERIC-STRING          | –       | Number of the first page received                                                                                                                                                      |
+| <Prolog>               | + | o | I   | PROLOG              | PATH                    | –       | Filename of the Control document                                                                                                                                                       |
+| Many files received    |   |   |     |                     |                         |         |                                                                                                                                                                                        |
+| <DocumentSpec>         | + | m | O   | FILENAME            | "@" <File-of-filespec>  | –       | Specifies a list of files; uses a special syntax                                                                                                                                       |
+
+TABLE 79/T.611
+
+#### **Additional CA-Descriptor settings for Telefax Group 4**
+
+| Keyword | Parameter | CA declares that                                |
+|---------|-----------|-------------------------------------------------|
+| FX4     | "STD"     | the Basic Telefax service is supported          |
+| FX4     | "OPD"     | the Operator Document transmission is supported |
+| FX4     | "MD"      | the Monitor Document transmission is supported  |
+| FX4     | "CTL"     | Control Document transmission is supported      |
+| FX4     | "DTM"     | Document Transparent Mode is supported          |
+| FX4     | "BFT"     | Binary File Transfer is supported               |
+| FX4     | "EDI"     | Electronic Data Interchange is supported        |
+
+TABLE 80/T.611
+
+#### **Additional syntax elements for the Teletex service**
+
+| Syntax element               | Purpose                                                                                                                            |
+|------------------------------|------------------------------------------------------------------------------------------------------------------------------------|
+| <Cil>                        | Specifies the contents of the Call Identification Line as defined per ITU-T Recommendation F.200. See also G.1                     |
+| <Convert>                    | Specifies the Transfer Format to be used                                                                                           |
+| <CvTtx>                      | Specifies the desired Transfer Format for received files                                                                           |
+| <Document>, <DocumentSpec>   | Specifies the document or the documents to be sent or being received                                                               |
+| <FirstPg>                    | Specifies the number of the first received page                                                                                    |
+| <From>                       | Transmission should start from the page number specified                                                                           |
+| <Name>                       | Assigns a name to the document to be sent or indicates the name of the received document as defined per ITU-T Recommendation T.571 |
+| <Originator>                 | Specifies the communications address of the originator                                                                             |
+| <Prolog>                     | Path to the "prolog" document                                                                                                      |
+| <Recipient>, <RecipientSpec> | Specifies the communications address(es) of the recipient(s)                                                                       |
+| <SubAddress>                 | Specifies the Originator's sub-address                                                                                             |
+| <T61Options>                 | Indicates the T.61 coding specific options                                                                                         |
+| <To>                         | Transmission should finish on page number specified                                                                                |
+| <Type>                       | Specifies the Transmission Format used                                                                                             |
+| <UserInfo>                   | Specifies a comment attached to the document to be sent/received. The comment is transmitted via the telecommunications service    |
+
+### 13.2 Text Based Encoding
+
+#### 13.2.1 Mapping of Keywords
+
+See Table 81.
+
+TABLE 81/T.611  
+Text Based Encoding of additional syntax elements for the Teletex service  
+(A ↵ denotes the new line format effector)
+
+| Syntax Element  | Keyword/Parameter Pair                  |
+|-----------------|-----------------------------------------|
+| <Cil>           | "CIL" ":" <Cil-parameter> ↵             |
+| <Convert>       | "CONVERT" ":" <Convert-id-parameter> ↵  |
+| <CvTtx>         | "CVTTX" ":" <Convert-id-parameter> ↵    |
+| <Document>      | "FILENAME" ":" <File-parameter> ↵       |
+| <DocumentSpec>  | "FILENAME" ":" "@" <File-of-filespec> ↵ |
+| <FirstPg>       | "FIRSTPG" ":" NUMERIC-STRING ↵          |
+| <From>          | "FROM" ":" NUMERIC-STRING ↵             |
+| <Name>          | "NAME" ":" (SIZE (1..12)) ↵             |
+| <Originator>    | "ADDRESS" ":" <Address-parameter> ↵     |
+| <Prolog>        | "PROLOG" ":" <Path-parameter> ↵         |
+| <Recipient>     | "ADDRESS" ":" <Address-parameter> ↵     |
+| <RecipientSpec> | "ADDRESS" ":" "@" <File-of-addrspec> ↵  |
+| <SubAddress>    | "SUBADDR" ":" <Sub-address-parameter> ↵ |
+| <T61Options>    | "T61OPTS" ":" <T61-options-parameter> ↵ |
+| <To>            | "TO" ":" NUMERIC-STRING ↵               |
+| <Type>          | "TYPE" ":" <Type-id-parameter> ↵        |
+| <UserInfo>      | "USERINFO" ":" STRING (SIZE (1..12)) ↵  |
+
+#### 13.2.2 Encoding of Parameters
+
+See also 6.4.4 for the encoding of non service dependent parameters used.
+
+##### 13.2.2.1 Service-id-parameter
+
+The Service-id parameter is encoded as STRING set to the constant value "TTX".
+
+*Syntax:*
+
+<Service-id-parameter> := "TTX"
+
+##### 13.2.2.2 Type-id-parameter
+
+The Type-id-parameter is encoded as STRING set to one of the following values:
+
+|       |                                                                             |
+|-------|-----------------------------------------------------------------------------|
+| "STD" | Basic Teletex Service (T.61)                                                |
+| "OPD" | Basic Teletex Service: Operator Document                                    |
+| "MD"  | Basic Teletex Service: Monitor Document                                     |
+| "CTL" | Basic Teletex Service: Control Document                                     |
+| "DTM" | Telematic File Transfer (TFT) of Teletex Service: Document Transparent Mode |
+| "EDI" | Telematic File Transfer (TFT) of Teletex Service: Edifact                   |
+| "BFT" | Teletex Service: Binary File Transfer                                       |
+
+NOTE – The Transmission Format STD is defined per ITU-T Recommendation T.61, the document types OPD, MD and CTL are defined per ITU-T Recommendation T.62 (Annex E), the TFT formats DTM and EDI are defined per ITU-T Recommendation T.571 and the Transmission Format BFT is defined per ITU-T Recommendation T.434.
+
+*Syntax:*
+
+<Type-id-parameter> := "STD" | "OPD" | "MD" | "CTL" | "DTM" | "BFT" | "EDI"
+
+##### 13.2.2.3 Convert-id-parameter
+
+The Convert-id-parameter is encoded as STRING set to one of the following values:
+
+|            |                                                                       |
+|------------|-----------------------------------------------------------------------|
+| "ASCII"    | APPLI/COM Extended ASCII                                              |
+| "ASCII437" | APPLI/COM Extended ASCII                                              |
+| "T.50"     | APPLI/COM Standard ASCII                                              |
+| "T.61"     | Basic Teletex Service coding as defined per ITU-T Recommendation T.61 |
+| "VOID"     | No conversion to be done                                              |
+
+The use of the Convert-id-parameter also depends on the Type-id selected. Table 82 depicts this.
+
+TABLE 82/T.611
+
+###### Permitted Convert-id assignments dependent on Type-id
+
+| Type-id                                                                                                          | Permitted Convert-id for incoming and outgoing traffic |
+|------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------|
+| STD, OPD, MD, CTL                                                                                                | ASCII, ASCII <sub>xxx</sub> <sup>a)</sup> , T.50, T.61 |
+| DTM, BFT, EDI                                                                                                    | VOID                                                   |
+| <sup>a)</sup> xxx stands for a code-page, declared in the ICE, e.g. ASCII437 if code-page 437 has been declared. |                                                        |
+
+*Syntax:*
+
+<Convert-id-parameter> := <Convert-txt> | <Convert-bin>  
+<Convert-txt> := <Ascii> | "T.50" | "T.61"  
+<Ascii> := "ASCII" | STRING ("ASCII" + <Code-page>)  
+<Code-page> := <digit> <digit> <digit>  
+<digit> := "0" | ... | "9"  
+<Convert-bin> := "VOID"
+
+##### 13.2.2.4 File-of-addrspec and Address-parameter
+
+The File-of-addrspec parameter is encoded as PATH which points to a file containing Addrspec-parameters, which contain the Address-parameter.
+
+The Address-parameter is encoded as STRING. The STRING consists of the recipient's terminal identifier as defined per ITU-T Recommendation F.200. The mnemonic part of the terminal identifier may be omitted or specified as a question mark ("?"), in which case no verification of the subscriber's address is performed. See also G.2.
+
+Alternatively the presence of the call number as raw dialling number may be indicated by placing an exclamation point ("!") in front of the first digit. This means the calling equipment must dial the digits that follow the exclamation point as is, without interpretation.
+
+Furthermore an alias name may be given instead of the terminal identifier, provided the alias is introduced with a "&" character. It is assumed that the CA knows how to decode the alias specified.
+
+*Syntax:*
+
+```
+<File-of-addrspec> :=          PATH
+                             -- The path points to a file containing one or more
+                             -- <Addrspec-parameter>s
+
+<Addrspec-parameter> :=      <Address-parameter>
+
+<Address-parameter> :=       <Terminal-id> | ("!" <Dial-sequence>) | ("&" <Alias>)
+
+<Terminal-id> :=              STRING
+                             -- The string shall present the terminal-id as defined per
+                             -- ITU-T Recommendation F.200
+
+<Dial-sequence> :=           NUMERIC-STRING
+
+<Alias> :=                    STRING
+```
+
+##### 13.2.2.5 File-of-filespec and File-parameter
+
+The File-of-filespec parameter is encoded as PATH which points to a file containing Filespec-parameters, which contain the File-parameter. The File-parameter itself is also encoded as PATH, which points to the file transferred.
+
+*Syntax:*
+
+```
+<File-of-filespec> :=          PATH
+                             -- The path points to a file containing one or more
+                             -- <Filespec-parameter>s
+
+<Filespec-parameter> :=       <File-parameter> ", " <File-conv> [ ", " [<File-type>]
+                             [ ", " <Send-parameter> | <SendAck-parameter> | <Receive-parameter> ] ]
+
+<Send-parameter> :=           [<File-name>] [ ", " <File-userinfo> ]
+
+<SendAck-parameter> :=        [<File-name>] [ ", " [<File-userinfo>] [ ", " <File-cil> ] ]
+
+<Receive-parameter> :=        [<File-name>] [ ", " [<File-userinfo>] [ ", " <File-cil> ] ]
+
+<File-parameter> :=           PATH
+                             -- Path to the file transferred
+
+<File-conv> :=                 <Convert-id-parameter>
+                             -- Specifies the Transfer Format of the file.
+
+<File-type> :=                 <Type-id-parameter>
+                             -- Specifies the Transmission Format of the file
+
+<File-name> :=                 STRING (SIZE(1..12))
+                             -- Specifies the name of the file to be transmitted
+```
+
+<File-userinfo> :=                   STRING (SIZE(1..12))  
+                                       -- *Specifies additional user to user info to be transmitted*
+
+<File-cil> :=                        Cil-parameter  
+                                       -- See 13.2.2.6
+
+##### 13.2.2.6 Cil-parameter
+
+A string of 72 characters as defined per ITU-T Recommendation F.200, composed as follows (see also G.1):
+
+|                                   |                                                 |
+|-----------------------------------|-------------------------------------------------|
+| Terminal identifier of recipient  | Length: 24 characters                           |
+| Separator                         | The character "/" (2F <sub>HEX</sub> )          |
+| Terminal identifier of originator | Length: 24 characters                           |
+| Separator                         | The character "/" (2F <sub>HEX</sub> )          |
+| Local date and time of originator | Length: 14 characters, format: "YY-MM-DD-HH:MM" |
+| Separator                         | The character "/" (2F <sub>HEX</sub> )          |
+| Reference information             | Length: 7 characters                            |
+
+*Syntax:*
+
+<Cil-parameter> :=                   <Recipient-tid> "/" <Originator-tid> "/" <Local-time> "/" <Ref-info>
+
+<Recipient-tid> :=                   STRING (SIZE(24))  
+                                       -- *The string presents the terminal-id as defined per*  
+                                       -- *ITU-T Recommendation F.184*
+
+<Originator-tid> :=                  STRING (SIZE(24))  
+                                       -- *The string presents the terminal-id as defined per*  
+                                       -- *ITU-T Recommendation F.184*
+
+<Local-time> :=                      <Date-time-parameter>
+
+<Ref-info> :=                        STRING (SIZE(7))
+
+##### 13.2.2.7 Sub-address-parameter
+
+The Sub-address-parameter is encoded as NUMERIC-STRING that represents a sub-address.
+
+*Syntax:*
+
+<Sub-address-parameter> :=        NUMERIC-STRING (SIZE(1..4))
+
+##### 13.2.2.8 T61-options-parameter
+
+For further study.
+
+*Syntax:*
+
+<T61-options-parameter> :=        STRING
+
+### 13.3 Additional Functionality
+
+#### 13.3.1 Function: Send and SendAck
+
+See Tables 83 and 84.
+
+#### 13.3.2 Function: Receive
+
+See Table 85.
+
+TABLE 83/T.611
+
+##### **Additional functionality of the <SendTDD> for the Teletex service**
+
+| Syntax Element                 | C | T | I/O | Text Based Encoding |                         |            | Comment                                                           |
+|--------------------------------|---|---|-----|---------------------|-------------------------|------------|-------------------------------------------------------------------|
+|                                |   |   |     | Keyword             | Parameter               | Default    |                                                                   |
+| <SubAddress>                   | + | o | I   | SUBADDR             | <Sub-address-parameter> | –          | Originator's sub-address                                          |
+| Send to one addressee          |   |   |     |                     |                         |            |                                                                   |
+| <Recipient>                    | B | m | I   | ADDRESS             | <Address-parameter>     | –          | Specifies one recipient's call number                             |
+| Send to one or many addressees |   |   |     |                     |                         |            |                                                                   |
+| <RecipientSpec>                | + | m | I   | ADDRESS             | "@" <File-of-addrspec>  | –          | Specifies a list of recipients                                    |
+| Send only one file             |   |   |     |                     |                         |            |                                                                   |
+| <Convert>                      | B | m | I   | CONVERT             | <Convert-id-parameter>  | –          | Transfer format of the outgoing file                              |
+| <Document>                     | B | m | I   | FILENAME            | <File-parameter>        | –          | Single file to be transmitted.                                    |
+| <Type>                         | B | o | I   | TYPE                | <Type-id-parameter>     | "STD"      | Specifies the document type to be sent                            |
+| <Name>                         | + | o | I   | NAME                | STRING (SIZE(1..12))    | –          | Filename parameter in TFT (T.571)                                 |
+| <UserInfo>                     | + | o | I   | USERINFO            | STRING (SIZE(1..12))    | –          | Userinfo is transmitted with the document                         |
+| <Prolog>                       | + | o | I   | PROLOG              | PATH                    | –          | Path to control document (T.62)                                   |
+| <From>                         | + | o | I   | FROM                | NUMERIC-STRING          | First page | The first page to be actually sent; does only apply to text files |
+| <To>                           | + | o | I   | TO                  | NUMERIC-STRING          | Last page  | The last page to be actually sent; does only apply to text files  |
+| <T61Options>                   | + | o | I   | T61OPTS             | <T61-options-parameter> | –          |                                                                   |
+| Send one or many files         |   |   |     |                     |                         |            |                                                                   |
+| <DocumentSpec>                 | + | m | I   | FILENAME            | "@" <File-of-filespec>  | –          | Specifies a list of files; uses a special syntax                  |
+
+TABLE 84/T.611
+
+##### **Additional functionality of the <SendAckTDD> for the Teletex service**
+
+| Syntax Element         | C | T | I/O | Text Based Encoding |                         |            | Comment                                                                                                       |
+|------------------------|---|---|-----|---------------------|-------------------------|------------|---------------------------------------------------------------------------------------------------------------|
+|                        |   |   |     | Keyword             | Parameter               | Default    |                                                                                                               |
+| <Recipient>            | B | m | I   | ADDRESS             | <Address-parameter>     | –          | Specifies one recipient's call number                                                                         |
+| <SubAddress>           | + | o | I   | SUBADDR             | <Sub-address-parameter> | –          | Originator's sub-address                                                                                      |
+| Send only one file     |   |   |     |                     |                         |            |                                                                                                               |
+| <Convert>              | B | m | I   | CONVERT             | <Convert-id-parameter>  | –          | Transfer format of the outgoing file                                                                          |
+| <Document>             | B | m | I   | FILENAME            | <File-parameter>        | –          | Single file to be transmitted, delivered under the Transfer Format specified by the Convert keyword           |
+| <Type>                 | B | o | I   | TYPE                | <Type-id-parameter>     | "STD"      | Specifies the document type to be sent                                                                        |
+| <Cil>                  | B | o | O   | CIL                 | <Cil-parameter>         | –          | Call identification line built by the CA (see ITU-T Rec. F.200)                                               |
+| <Name>                 | + | o | I   | NAME                | STRING (SIZE(1..12))    | –          | Assigns a "name" to the files to be sent. Corresponds to the filename parameter in TFT (see ITU-T Rec. T.571) |
+| <UserInfo>             | + | o | I   | USERINFO            | STRING (SIZE(1..12))    | –          | Assigns an user comment to the document. This comment is transmitted with the document                        |
+| <Prolog>               | + | o | I   | PROLOG              | PATH                    | –          | Filename of the "control document" (full path)                                                                |
+| <From>                 | + | o | I   | FROM                | NUMERIC-STRING          | First page | The first page to be actually sent; does only apply to text files                                             |
+| <To>                   | + | o | I   | TO                  | NUMERIC-STRING          | Last page  | The last page to be actually sent; does only apply to text files                                              |
+| <T61Options>           | + | o | I   | T61OPTS             | <T61-options-parameter> | –          |                                                                                                               |
+| Send one or many files |   |   |     |                     |                         |            |                                                                                                               |
+| <DocumentSpec>         | + | m | I   | FILENAME            | "@" <File-of-filespec>  | –          | Specifies a list of files; uses a special syntax                                                              |
+
+TABLE 85/T.611
+
+##### **Additional functionality of the <ReceiveTDD> for the Teletex service**
+
+| Syntax Element         | C | T | I/O | Text Based Encoding |                         |         | Comment                                                                                                                                                                 |
+|------------------------|---|---|-----|---------------------|-------------------------|---------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+|                        |   |   |     | Keyword             | Parameter               | Default |                                                                                                                                                                         |
+| <Originator>           | B | o | O   | ADDRESS             | <Address-parameter>     | –       | Specifies originator's phone number                                                                                                                                     |
+| <CvTx>                 | B | o | I   | CVTTX               | <Convert-id-parameter>  | "T.61"  | Transfer format desired by the LA                                                                                                                                       |
+| <SubAddress>           | + | o | I/O | SUBADDR             | <Sub-address-parameter> | –       | Recipient's sub-address; if specified in the Request, used as a selector for retrieval                                                                                  |
+| Only one file received |   |   |     |                     |                         |         |                                                                                                                                                                         |
+| <Convert>              | B | m | O   | CONVERT             | <Convert-id-parameter>  | –       | States the Transfer Format of the received file                                                                                                                         |
+| <Document>             | B | m | I/O | FILENAME            | <File-parameter>        | –       | Filename may be pre-set by the LA. If only one file is received, the path shall be retained by the CA. If many files are received the name may be overwritten by the CA |
+| <Type>                 | B | o | O   | TYPE                | <Type-id-parameter>     | –       | Specifies the document type received                                                                                                                                    |
+| <Cil>                  | B | o | O   | CIL                 | <Cil-parameter>         | –       | Call identification line built by the CA (see ITU-T Rec. F.200)                                                                                                         |
+| <Name>                 | + | o | O   | NAME                | STRING (SIZE(1..12))    | –       | Returns the name of the incoming file (12 characters maximum)                                                                                                           |
+| <UserInfo>             | + | o | O   | USERINFO            | STRING (SIZE(1..12))    | –       | Assigns an user comment to the document. This comment is transmitted with the document                                                                                  |
+| <FirstPg>              | + | o | O   | FIRSTPG             | NUMERIC-STRING          | –       | Number of the first page received                                                                                                                                       |
+| <Prolog>               | + | o | I   | PROLOG              | PATH                    | –       | Filename of the Control document                                                                                                                                        |
+| Many files received    |   |   |     |                     |                         |         |                                                                                                                                                                         |
+| <DocumentSpec>         | + | m | O   | FILENAME            | "@" <File-of-filespec>  | –       | Specifies a list of files; uses a special syntax                                                                                                                        |
+
+### **13.4 CA-Descriptor Settings**
+
+A CA supporting the TTX service shall specify the supported Type-id (document Transmission Formats) in the CA-Descriptor (see 9.5) Table 86 below shows the possible assignments.
+
+TABLE 86/T.611
+
+#### **Additional CA-Descriptor settings for the Teletex service**
+
+| Keyword | Parameter | CA declares that                                |
+|---------|-----------|-------------------------------------------------|
+| TTX     | "STD"     | the basic Teletex service (T.61) is supported   |
+| TTX     | "OPD"     | the Operator Document transmission is supported |
+| TTX     | "MD"      | the Monitor Document transmission is supported  |
+| TTX     | "CTL"     | Control Document transmission is supported      |
+| TTX     | "DTM"     | Document Transparent Mode is supported          |
+| TTX     | "BFT"     | Binary File Transfer is supported               |
+| TTX     | "EDI"     | Electronic Data Interchange is supported        |
+
+## **14 Service: Telex via Teletex**
+
+### **14.1 Service Specific Syntax Elements**
+
+<ServiceDependentKeywordsSend> :=  
+     (<Recipient> | <RecipientSpec>)  
+     (((<Document> <Convert> [<Type>] [From] [To]) | <DocumentSpec>)  
+     [<SubAddress>] [<Notify>])
+
+<ServiceDependentKeywordsSendAck> :=  
+     <Recipient>  
+     (((<Document> <Convert> [<Type>] [From] [To]) | <DocumentSpec>)  
+     [<SubAddress>] [<Notify>])
+
+<ServiceDependentKeywordsReceive> :=  
+     [<Originator>] ((<Document> <Convert> <Type>) | <DocumentSpec>)  
+     [<CvTx>] [<SubAddress>]
+
+TABLE 87/T.611
+
+#### **Additional syntax elements for the Telex via Teletex service**
+
+| Syntax element               | Purpose                                                              |
+|------------------------------|----------------------------------------------------------------------|
+| <Convert>                    | Specifies the Transfer Format to be used                             |
+| <CvTx>                       | Specifies the desired Transfer Format for received files             |
+| <Document>, <DocumentSpec>   | Specifies the document or the documents to be sent or being received |
+| <From>                       | Transmission should start from the page number specified             |
+| <Notify>                     | Specifies whether delivery notification is requested                 |
+| <Originator>                 | Specifies the communications address of the originator               |
+| <Recipient>, <RecipientSpec> | Specifies the communications address(es) of the recipient(s)         |
+| <SubAddress>                 | Specifies the Originator's sub-address                               |
+| <To>                         | Transmission should finish on page number specified                  |
+| <Type>                       | Specifies the Transmission Format used                               |
+
+### 14.2 Text Based Encoding
+
+#### 14.2.1 Mapping of Keywords
+
+See Table 88.
+
+TABLE 88/T.611
+
+##### **Text Based Encoding of additional syntax elements for the Telex via Teletex service** (A ↵ denotes the new line format effector)
+
+| Syntax Element  | Keyword/Parameter Pair                  |
+|-----------------|-----------------------------------------|
+| <Convert>       | "CONVERT" ":" <Convert-id-parameter> ↵  |
+| <CvTx>          | "CVTX" ":" <Convert-id-parameter> ↵     |
+| <Document>      | "FILENAME" ":" <File-parameter> ↵       |
+| <DocumentSpec>  | "FILENAME" ":" "@" <File-of-filespec> ↵ |
+| <From>          | "FROM" ":" NUMERIC-STRING ↵             |
+| <Notify>        | "NOTIFY" ":" <Boolean-parameter> ↵      |
+| <Originator>    | "ADDRESS" ":" <Address-parameter> ↵     |
+| <Recipient>     | "ADDRESS" ":" <Address-parameter> ↵     |
+| <RecipientSpec> | "ADDRESS" ":" "@" <File-of-addrspec> ↵  |
+| <SubAddress>    | "SUBADDR" ":" <Sub-address-parameter> ↵ |
+| <To>            | "TO" ":" NUMERIC-STRING ↵               |
+| <Type>          | "TYPE" ":" <Type-id-parameter> ↵        |
+
+#### 14.2.2 Encoding of Parameters
+
+See also 6.4.4 for the encoding of non service dependent parameters used.
+
+##### 14.2.2.1 Service-id-parameter
+
+The Service-id parameter is encoded as STRING set to the constant value "TX".
+
+*Syntax:*
+
+<Service-id-parameter> := "TX"
+
+##### 14.2.2.2 Type-id-parameter
+
+The Type-id-parameter is encoded as STRING set to the constant value "STD".
+
+*Syntax:*
+
+<Type-id-parameter> := "STD"
+
+NOTE – The Transmission Format STD is defined per ITU-T Recommendation S.1.
+
+##### 14.2.2.3 Convert-id-parameter
+
+The Convert-id-parameter is encoded as STRING set to one of the following values:
+
+|            |                          |
+|------------|--------------------------|
+| "ASCII"    | APPLI/COM Extended ASCII |
+| "ASCII437" | APPLI/COM Extended ASCII |
+| "T.50"     | APPLI/COM Standard ASCII |
+
+*Syntax:*
+
+```
+<Convert-id-parameter> :=      <Ascii> | "T.50"
+<Ascii> :=    "ASCII" | STRING ("ASCII" + <Code-page>)
+<Code-page> :=  <digit> <digit> <digit>
+<digit> :=    "0" | ... | "9"
+```
+
+##### 14.2.2.4 File-of-addrspec and Address-parameter
+
+The File-of-addrspec parameter is encoded as PATH which points to a file containing Addrspec-parameters, which contain the Address-parameter.
+
+The Address-parameter is encoded as STRING forming the call number. If a subscriber identification verification is to be performed, the answerback unit of the receiving terminal must be entered after the call number, separated by a "equal" sign ("=").
+
+Alternatively an alias name may be given instead of the terminal identifier, provided the alias is introduced with a "&" character. It is assumed that the CA knows how to decode the alias specified.
+
+NOTE – If it is intended to perform a subscriber identification verification, the complete answerback unit must be entered after the equal sign, and not just the alphabetic component of the receiver.
+
+*Syntax:*
+
+```
+<File-of-addrspec> :=          PATH
+                                -- The path points to a file containing one or more
+                                -- <Addrspec-parameter>s
+<Addrspec-parameter> :=      <Address-parameter>
+<Address-parameter> :=      <Telex-address> | ("&" <Alias>)
+<Telex-address> :=          STRING
+                                -- The string shall present a valid telex address
+<Alias> :=                  STRING
+```
+
+##### 14.2.2.5 File-of-filespec and File-parameter
+
+The File-of-filespec parameter is encoded as PATH which points to a file containing Filespec-parameters, which contain the File-parameter. The File-parameter itself is also encoded as PATH, which points to the file transferred.
+
+*Syntax:*
+
+```
+<File-of-filespec> :=          PATH
+                                -- The path points to a file containing one or more
+                                -- <Filespec-parameter>s
+<Filespec-parameter> :=      <File-parameter> ", " <File-conv> [ ", " <File-type> ]
+<File-parameter> :=          PATH
+                                -- Path to the file transferred
+<File-conv> :=                <Convert-id-parameter>
+                                -- Specifies the Transfer Format of the file.
+<File-type> :=                <Type-id-parameter>
+                                -- Specifies the Transmission Format of the file
+```
+
+##### 14.2.2.6 Sub-address-parameter
+
+The Sub-address-parameter is encoded as NUMERIC-STRING that represents a sub-address.
+
+*Syntax:*
+
+<Sub-address-parameter> := NUMERIC-STRING
+
+### 14.3 Additional Functionality
+
+#### 14.3.1 Function: Send and SendAck
+
+See Tables 89 and 90.
+
+TABLE 89/T.611
+
+**Additional functionality of the <SendTDD> for the Telex via Teletex service**
+
+| Syntax Element                 | C | T | I/O | Text Based Encoding |                         |            | Comment                                                                                             |
+|--------------------------------|---|---|-----|---------------------|-------------------------|------------|-----------------------------------------------------------------------------------------------------|
+|                                |   |   |     | Keyword             | Parameter               | Default    |                                                                                                     |
+| <Notify>                       | + | o | I   | NOTIFY              | <Boolean-parameter>     | "Yes"      |                                                                                                     |
+| <SubAddress>                   | + | o | I   | SUBADDR             | <Sub-address-parameter> | –          | Originator's sub-address                                                                            |
+| Send to one addressee          |   |   |     |                     |                         |            |                                                                                                     |
+| <Recipient>                    | B | m | I   | ADDRESS             | <Address-parameter>     | –          | Specifies one recipient's call number                                                               |
+| Send to one or many addressees |   |   |     |                     |                         |            |                                                                                                     |
+| <RecipientSpec>                | + | m | I   | ADDRESS             | "@" <File-of-addrspec>  | –          | Specifies a list of recipients                                                                      |
+| Send only one file             |   |   |     |                     |                         |            |                                                                                                     |
+| <Convert>                      | B | m | I   | CONVERT             | <Convert-id-parameter>  | –          | Transfer format of the outgoing file                                                                |
+| <Document>                     | B | m | I   | FILENAME            | <File-parameter>        | –          | Single file to be transmitted, delivered under the Transfer Format specified by the Convert keyword |
+| <Type>                         | B | o | I   | TYPE                | <Type-id-parameter>     | "STD"      | Specifies the document type to be sent                                                              |
+| <From>                         | + | o | I   | FROM                | NUMERIC-STRING          | First page | The first page to be actually sent; does only apply to text files                                   |
+| <To>                           | + | o | I   | TO                  | NUMERIC-STRING          | Last page  | The last page to be actually sent; does only apply to text files                                    |
+| Send one or many files         |   |   |     |                     |                         |            |                                                                                                     |
+| <DocumentSpec>                 | + | m | I   | FILENAME            | "@" <File-of-filespec>  | –          | Specifies a list of files; uses a special syntax                                                    |
+
+TABLE 90/T.611
+
+##### **Additional functionality of the <SendAckTDD> for the Telex via Teletex service**
+
+| Syntax Element         | C | T | I/O | Text Based Encoding |                         |            | Comment                                                                                             |
+|------------------------|---|---|-----|---------------------|-------------------------|------------|-----------------------------------------------------------------------------------------------------|
+|                        |   |   |     | Keyword             | Parameter               | Default    |                                                                                                     |
+| <Recipient>            | B | m | I   | ADDRESS             | <Address-parameter>     | –          | Specifies one recipient's call number                                                               |
+| <Notify>               | + | o | I   | NOTIFY              | <Boolean-parameter>     | "Yes"      |                                                                                                     |
+| <SubAddress>           | + | o | I   | SUBADDR             | <Sub-address-parameter> | –          | Originator's sub-address                                                                            |
+| Send only one file     |   |   |     |                     |                         |            |                                                                                                     |
+| <Convert>              | B | m | I   | CONVERT             | <Convert-id-parameter>  | –          | Transfer format of the outgoing file                                                                |
+| <Document>             | B | m | I   | FILENAME            | <File-parameter>        | –          | Single file to be transmitted, delivered under the Transfer Format specified by the Convert keyword |
+| <Type>                 | B | o | I   | TYPE                | <Type-id-parameter>     | "STD"      | Specifies the document type to be sent                                                              |
+| <From>                 | + | o | I   | FROM                | NUMERIC-STRING          | First page | The first page to be actually sent; does only apply to text files                                   |
+| <To>                   | + | o | I   | TO                  | NUMERIC-STRING          | Last page  | The last page to be actually sent; does only apply to text files                                    |
+| Send one or many files |   |   |     |                     |                         |            |                                                                                                     |
+| <DocumentSpec>         | + | m | I   | FILENAME            | "@" <File-of-filespec>  | –          | Specifies a list of files; uses a special syntax                                                    |
+
+#### **14.3.2 Function: Receive**
+
+See Table 91.
+
+### **14.4 CA-Descriptor Settings**
+
+A CA supporting the TX service shall specify the supported Type-id (document Transmission Formats) in the CA-Descriptor (see 9.5) Table 9.2 shows the possible assignments.
+
+TABLE 91/T.611
+
+#### **Additional functionality of the <ReceiveTDD> for the Telex via Teletex service**
+
+| Syntax Element         | C | T | I/O | Text Based Encoding |                         |         | Comment                                                                                                                                                                                |
+|------------------------|---|---|-----|---------------------|-------------------------|---------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+|                        |   |   |     | Keyword             | Parameter               | Default |                                                                                                                                                                                        |
+| <Originator>           | B | o | O   | ADDRESS             | <Address-parameter>     | –       | Specifies originator's phone number                                                                                                                                                    |
+| <CvTx>                 | B | o | I   | CVTX                | <Convert-id-parameter>  | "T.50"  | Transfer format desired by the LA                                                                                                                                                      |
+| <SubAddress>           | + | o | I/O | SUBADDR             | <Sub-address-parameter> | –       | Recipient's sub-address; if specified in the Request, used as a selector for the retrieval                                                                                             |
+| Only one file received |   |   |     |                     |                         |         |                                                                                                                                                                                        |
+| <Convert>              | B | m | O   | CONVERT             | <Convert-id-parameter>  | –       | States the Transfer Format of the received file                                                                                                                                        |
+| <Document>             | B | m | I/O | FILENAME            | <File-parameter>        | –       | The filename may be pre-set by the LA on request. If only one file is received, the name shall be retained by the CA. If many files are received the name may be overwritten by the CA |
+| <Type>                 | B | o | O   | TYPE                | <Type-id-parameter>     | –       | Specifies the document type received                                                                                                                                                   |
+| Many files received    |   |   |     |                     |                         |         |                                                                                                                                                                                        |
+| <DocumentSpec>         | + | m | O   | FILENAME            | "@" <File-of-filespec>  | –       | Specifies a list of files; uses a special syntax                                                                                                                                       |
+
+TABLE 92/T.611
+
+#### **Additional CA-Descriptor settings for the Telex via Teletex service**
+
+| Keyword | Parameter | CA declares that               |
+|---------|-----------|--------------------------------|
+| TX      | "STD"     | the basic service is supported |
+
+## 15 Service: Telex
+
+### 15.1 Service Specific Syntax Elements
+
+<ServiceDependentKeywordsSend> :=  
+    (<Recipient> | <RecipientSpec>)  
+    (((<Document> <Convert> [<Type>] [From] [To]) | <DocumentSpec>)  
+    [<SubAddress>])
+
+<ServiceDependentKeywordsSendAck> :=  
+    <Recipient>  
+    (((<Document> <Convert> [<Type>] [From] [To]) | <DocumentSpec>)  
+    [<SubAddress>])
+
+<ServiceDependentKeywordsReceive> :=  
+    [<Originator>] ((<Document> <Convert> <Type>) | <DocumentSpec>)  
+    [<CvTlx>] [<SubAddress>]
+
+See Table 93.
+
+TABLE 93/T.611
+
+**Additional syntax elements for the Telex service**
+
+| Syntax element               | Purpose                                                              |
+|------------------------------|----------------------------------------------------------------------|
+| <Convert>                    | Specifies the Transfer Format to be used                             |
+| <CvTlx>                      | Specifies the desired Transfer Format for received files             |
+| <Document>, <DocumentSpec>   | Specifies the document or the documents to be sent or being received |
+| <From>                       | Transmission should start from the page number specified             |
+| <Originator>                 | Specifies the communications address of the originator               |
+| <Recipient>, <RecipientSpec> | Specifies the communications address(es) of the recipient(s)         |
+| <SubAddress>                 | Specifies the Originator's sub-address                               |
+| <To>                         | Transmission should finish on page number specified                  |
+| <Type>                       | Specifies the Transmission Format used                               |
+
+### 15.2 Text Based Encoding
+
+#### 15.2.1 Mapping of Keywords
+
+See Table 94.
+
+#### 15.2.2 Encoding of Parameters
+
+See also 6.4.4 for the encoding of non service dependent parameters used.
+
+##### 15.2.2.1 Service-id-parameter
+
+The Service-id-parameter is encoded as STRING set to the constant value "TLX".
+
+*Syntax:*
+
+<Service-id-parameter> := "TLX"
+
+TABLE 94/T.611
+
+###### **Text Based Encoding of additional syntax elements for the Telex service**
+
+(A ↵ denotes the new line format effector)
+
+| Syntax Element  | Keyword/Parameter Pair                  |
+|-----------------|-----------------------------------------|
+| <Convert>       | "CONVERT" ":" <Convert-id-parameter> ↵  |
+| <CvTlx>         | "CVTLX" ":" <Convert-id-parameter> ↵    |
+| <Document>      | "FILENAME" ":" <File-parameter> ↵       |
+| <DocumentSpec>  | "FILENAME" ":" "@" <File-of-filespec> ↵ |
+| <From>          | "FROM" ":" NUMERIC-STRING ↵             |
+| <Originator>    | "ADDRESS" ":" <Address-parameter> ↵     |
+| <Recipient>     | "ADDRESS" ":" <Address-parameter> ↵     |
+| <RecipientSpec> | "ADDRESS" ":" "@" <File-of-addrspec> ↵  |
+| <SubAddress>    | "SUBADDR" ":" <Sub-address-parameter> ↵ |
+| <To>            | "TO" ":" NUMERIC-STRING ↵               |
+| <Type>          | "TYPE" ":" <Type-id-parameter> ↵        |
+
+##### **15.2.2.2 Type-id-parameter**
+
+The Type-id-parameter is encoded as STRING set to the constant value "STD".
+
+*Syntax:*
+
+<Type-id-parameter> := "STD"
+
+NOTE – The Transmission Format STD is defined per ITU-T Recommendation S.1.
+
+##### **15.2.2.3 Convert-id-parameter**
+
+The Convert-id-parameter is encoded as STRING set to one of the following values:
+
+|            |                          |
+|------------|--------------------------|
+| "ASCII"    | APPLI/COM Extended ASCII |
+| "ASCII437" | APPLI/COM Extended ASCII |
+| "T.50"     | APPLI/COM Standard ASCII |
+
+*Syntax:*
+
+<Convert-id-parameter> := <Ascii> | "T.50"
+
+<Ascii> := "ASCII" | STRING ("ASCII" + Code-page>)
+
+<Code-page> := <digit> <digit> <digit>
+
+<digit> := "0" | ... | "9"
+
+##### **15.2.2.4 File-of-addrspec and Address-parameter**
+
+The File-of-addrspec parameter is encoded as PATH which points to a file containing Addrsec-parameters, which contain the Address-parameter.
+
+The Address-parameter is encoded as STRING forming the call number. If a subscriber identification verification is to be performed, the answerback unit of the receiving terminal must be entered after the call number, separated by an "equal" sign ("=").
+
+Alternatively an alias name may be given instead of the terminal identifier, provided the alias is introduced with a "&" character. It is assumed that the CA knows how to decode the alias specified.
+
+NOTE – If it is intended to perform a subscriber identification verification, the complete answerback unit must be entered after the equal sign, and not just the alphabetic component of the receiver.
+
+Syntax:
+
+```
+<File-of-addrspec> :=          PATH
+-- The path points to a file containing one ore more
+-- <Addrspec-parameter>s
+
+<Addrspec-parameter> :=      <Address-parameter>
+
+<Address-parameter> :=       <Telex-address> | ("&" <Alias>)
+
+<Telex-address> :=           STRING
+-- The string shall present a valid telex address
+
+<Alias> :=                   STRING
+```
+
+##### 15.2.2.5 File-of-filespec and File-parameter
+
+The File-of-filespec parameter is encoded as PATH which points to a file containing Filespec-parameters, which contain the File-parameter. The File-parameter itself is also encoded as PATH, which points to the file transferred.
+
+Syntax:
+
+```
+<File-of-filespec> :=          PATH
+-- The path points to a file containing one ore more
+-- <Filespec-parameter>s
+
+<Filespec-parameter> :=       <File-parameter> ", " <File-conv> [", " <File-type>]
+
+<File-parameter> :=           PATH
+-- Path to the file transferred
+
+<File-conv> :=                 <Convert-id-parameter>
+-- Specifies the Transfer Format of the file
+
+<File-type> :=                 <Type-id-parameter>
+-- Specifies the Transmission Format of the file
+```
+
+##### 15.2.2.6 Sub-address-parameter
+
+The Sub-address-parameter is encoded as NUMERIC-STRING that represents a sub-address.
+
+Syntax:
+
+```
+<Sub-address-parameter>:=      NUMERIC-STRING
+```
+
+### 15.3 Additional Functionality
+
+#### 15.3.1 Function: Send and SendAck
+
+See Table 95 and 96.
+
+TABLE 95/T.611
+
+##### **Additional functionality of the <SendTDD> for the Telex service**
+
+| Syntax Element                | C | T | I/O | Text Based Encoding |                         |            | Comment                                                                                             |
+|-------------------------------|---|---|-----|---------------------|-------------------------|------------|-----------------------------------------------------------------------------------------------------|
+|                               |   |   |     | Keyword             | Parameter               | Default    |                                                                                                     |
+| <SubAddress>                  | + | o | I   | SUBADDR             | <Sub-address-parameter> | –          | Originator's sub-address                                                                            |
+| Send to one addressee         |   |   |     |                     |                         |            |                                                                                                     |
+| <Recipient>                   | B | m | I   | ADDRESS             | <Address-parameter>     | –          | Specifies one recipient's call number                                                               |
+| Set to one or many addressees |   |   |     |                     |                         |            |                                                                                                     |
+| <RecipientSpec>               | + | m | I   | ADDRESS             | "@" <File-of-addrspec>  | –          | Specifies a list of recipients                                                                      |
+| Send only one file            |   |   |     |                     |                         |            |                                                                                                     |
+| <Convert>                     | B | m | I   | CONVERT             | <Convert-id-parameter>  | –          | Transfer format of the outgoing file                                                                |
+| <Document>                    | B | m | I   | FILENAME            | <File-parameter>        | –          | Single file to be transmitted, delivered under the Transfer Format specified by the Convert keyword |
+| <Type>                        | B | o | I   | TYPE                | <Type-id-parameter>     | "STD"      | Specifies the document type to be sent                                                              |
+| <From>                        | + | o | I   | FROM                | NUMERIC-STRING          | First page | The first page to be actually sent; does only apply to text files                                   |
+| <To>                          | + | o | I   | TO                  | NUMERIC-STRING          | Last page  | The last page to be actually sent; does only apply to text files                                    |
+| Send one or many files        |   |   |     |                     |                         |            |                                                                                                     |
+| <DocumentSpec>                | + | m | I   | FILENAME            | "@" <File-of-filespec>  | –          | Specifies a list of files; uses a special syntax                                                    |
+
+TABLE 96/T.611
+
+##### **Additional functionality of the <SendAckTDD> for the Telex via Teletex service**
+
+| Syntax Element         | C | T | I/O | Text Based Encoding |                         |            | Comment                                                                                             |
+|------------------------|---|---|-----|---------------------|-------------------------|------------|-----------------------------------------------------------------------------------------------------|
+|                        |   |   |     | Keyword             | Parameter               | Default    |                                                                                                     |
+| <Recipient>            | B | m | I   | ADDRESS             | <Address-parameter>     | –          | Specifies one recipient's call number                                                               |
+| <SubAddress>           | + | o | I   | SUBADDR             | <Sub-address-parameter> | –          | Originator's sub-address                                                                            |
+| Send only one file     |   |   |     |                     |                         |            |                                                                                                     |
+| <Convert>              | B | m | I   | CONVERT             | <Convert-id-parameter>  | –          | Transfer format of the outgoing file                                                                |
+| <Document>             | B | m | I   | FILENAME            | <File-parameter>        | –          | Single file to be transmitted, delivered under the Transfer Format specified by the Convert keyword |
+| <Type>                 | B | o | I   | TYPE                | <Type-id-parameter>     | "STD"      | Specifies the document type to be sent                                                              |
+| <From>                 | + | o | I   | FROM                | NUMERIC-STRING          | First page | The first page to be actually sent; does only apply to text files                                   |
+| <To>                   | + | o | I   | TO                  | NUMERIC-STRING          | Last page  | The last page to be actually sent; does only apply to text files                                    |
+| Send one or many files |   |   |     |                     |                         |            |                                                                                                     |
+| <DocumentSpec>         | + | m | I   | FILENAME            | "@" <File-of-filespec>  | –          | Specifies a list of files; uses a special syntax                                                    |
+
+#### 15.3.2 Function: Receive
+
+See Table 97.
+
+TABLE 97/T.611
+
+##### Additional functionality of the <ReceiveTDD> for the Telex via Teletex service
+
+| Syntax Element         | C | T | I/O | Text Based Encoding |                         |         | Comment                                                                                                                                                                                |
+|------------------------|---|---|-----|---------------------|-------------------------|---------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+|                        |   |   |     | Keyword             | Parameter               | Default |                                                                                                                                                                                        |
+| <Originator>           | B | o | O   | ADDRESS             | <Address-parameter>     | –       | Specifies originator's phone number                                                                                                                                                    |
+| <CvTlx>                | B | o | I   | CVTLX               | <Convert-id-parameter>  | "T.50"  | Transfer format desired by the LA                                                                                                                                                      |
+| <SubAddress>           | + | o | I/O | SUBADDR             | <Sub-address-parameter> | –       | Recipient's sub-address; if specified in the Request, used as a selector for the retrieval                                                                                             |
+| Only one file received |   |   |     |                     |                         |         |                                                                                                                                                                                        |
+| <Convert>              | B | m | O   | CONVERT             | <Convert-id-parameter>  | –       | States the Transfer Format of the received file                                                                                                                                        |
+| <Document>             | B | m | I/O | FILENAME            | <File-parameter>        | –       | The filename may be pre-set by the LA on request. If only one file is received, the name shall be retained by the CA. If many files are received the name may be overwritten by the CA |
+| <Type>                 | B | o | O   | TYPE                | <Type-id-parameter>     | –       | Specifies the document type received                                                                                                                                                   |
+| Many files received    |   |   |     |                     |                         |         |                                                                                                                                                                                        |
+| <DocumentSpec>         | + | m | O   | FILENAME            | "@" <File-of-filespec>  | –       | Specifies a list of files; uses a special syntax                                                                                                                                       |
+
+### 15.4 CA-Descriptor Settings
+
+A CA supporting the TX service shall specify the supported Type-id (document Transmission Formats) in the CA-Descriptor (see 9.5) Table 98 shows the possible assignments.
+
+TABLE 98/T.611
+
+#### Additional CA-Descriptor settings for the Telex service
+
+| Keyword | Parameter | CA declares that               |
+|---------|-----------|--------------------------------|
+| TX      | "STD"     | the basic service is supported |
+
+## 16 Service: E-Mail
+
+This Recommendation allows sending or receiving information through E-Mail services. Full exhaustive control of E-Mail services through the interface is not intended.
+
+The definitions made hereafter furthermore enable the access to the Message Handling System (MHS), as described in the ITU-T X.400-Series of Recommendations. In terms of MHS, the interface provides access to Interpersonal Messaging.
+
+The implementation of the CA may rely on other E-Mail supporting interfaces as shown in Figure 15. The CA shown uses an underlying E-Mail interface to communicate with the E-Mail service provider. In general, the CA is free to use *any* E-Mail interface to access and control the E-Mail services.
+
+![Model for E-Mail access diagram showing the flow from a Local Application through a Communication Application and an E-Mail Service Provider to a Network.](90321ffa3cade82e4a57d6250d046c88_img.jpg)
+
+The diagram illustrates the model for E-Mail access. It shows a vertical stack of components connected by interfaces. At the top is a 'Local Application' box with a person icon. Below it is a 'Communication Application' box. These two are connected by a bidirectional arrow labeled 'APPLI/COM Interface'. Below the 'Communication Application' is a horizontal bar representing 'any E-Mail Interface (Service Interface)'. A solid arrow points from the 'Communication Application' down to this bar. Below the bar is an 'E-Mail Service Provider' box. A solid arrow points from the bar down to the 'E-Mail Service Provider'. A dashed curved arrow also points from the 'Local Application' down to the 'E-Mail Service Provider'. Below the 'E-Mail Service Provider' is another horizontal bar representing the 'Network Interface'. A solid arrow points from the 'E-Mail Service Provider' down to this bar. At the bottom is a 'Network' oval. A solid arrow points from the 'Network Interface' bar down to the 'Network'. Large grey arrows on the left and right sides of the 'any E-Mail Interface' and 'Network Interface' bars indicate external connections.
+
+T0823530-94/d19
+
+Model for E-Mail access diagram showing the flow from a Local Application through a Communication Application and an E-Mail Service Provider to a Network.
+
+FIGURE 15/T.611  
+Model for E-Mail access
+
+MHS and other E-Mail systems standardize the syntax and semantic of Interpersonal Messages (IPMs) as well as the syntax and semantic of Interpersonal Notifications (IPNs)<sup>9)</sup> and Delivery Reports (DRs).
+
+<sup>9)</sup> For MHS, ITU-T Recommendation X.420 standardizes the syntax of IPMs and IPNs. In the version from 1984 of ITU-T Recommendation X.420 the notifications were called SR-UAPDU.
+
+A recipient may create and send an IPN automatically or on request of the LA (explicit notification). The IPNs may either be:
+
+- a Receipt Notification (RN): the IPM was received;
+- a Non Receipt Notification (NRN): the IPM was not delivered; in this case, the undelivered IPM may be transmitted with the NRN.
+
+Contrary to an IPN the DR is created by the message transfer system. The DRs are distinguished in:
+
+- a Delivery Report (DR); or
+- a Non-delivery Report (NDR).
+
+In the Send and SendAck TDDs the LA may specify, which Interpersonal Notification (IPN) or Delivery Report (DR) shall be generated for each recipient. For more information see 16.2.2.6, 16.4 and 16.5.
+
+MHS and other E-Mail systems allow complete IPMs - consisting of heading and body parts – to be transferred as body part in a message.
+
+This Recommendation supports the transfer of such body parts in the Send (SendAck) and Receive TDDs through a specific Type-id-parameter (the Type-ID MESSAGE, see 16.2.2.2). Since the content of such a body part is encoded<sup>10)</sup>, this Recommendation allows to decode and encode such a body part by use of the EncodeIPM and DecodeIPM TDDs.
+
+In case of MHS the IPM is encoded according to ASN.1 BER.
+
+The EncodeIPM and DecodeIPM TDDs shall be implemented using the <ExtendTDD>. The extensions are called:
+
+- <EncodeIPMExtension>; and
+- <DecodeIPMExtension> respectively.
+
+The EncodeIPM and DecodeIPM TDDs are described in 16.3.3.
+
+### 16.1 Service Specific Syntax Elements
+
+Below the service dependent extensions of the generic TDD syntax referred to in 6.1 are shown:
+
+```
+<ServiceDependentKeywordsSend> :=
+    <S-RecipientSpec> [<S-OriginatorSpec>]
+    ((<Document> <Convert> [<Type>]) | <DocumentSpec>)
+    <IpmlId> [<Alternate>] [<ContType>] [<DiscloRec>] [<ExpiryTime>]
+    [<ImplicitConv>] [<Importance>] [<Language>] [<Priority>] [<RelatedSpec>]
+    [<ReplyId>] [<ReplyTime>] [<Sensitivity>] [<Subject>] [<UserInfo>]
+
+<ServiceDependentKeywordsSendAck> :=
+    <S-RecipientSpec> [<S-OriginatorSpec>]
+    ((<Document> <Convert> [<Type>]) | <DocumentSpec>)
+    <IpmlId> [<Alternate>] [<ContType>] [<DiscloRec>] [<ExpiryTime>]
+    [<ImplicitConv>] [<Importance>] [<Language>] [<Priority>] [<RelatedSpec>]
+    [<ReplyId>] [<ReplyTime>] [<Sensitivity>] [<Subject>] [<UserInfo>]
+    [<MsgSubId>] [<SubmitTime>]
+
+<ServiceDependentKeywordsReceive> :=
+    <R-RecipientSpec> [<R-OriginatorSpec>]
+    ((<Document> <Convert> [<Type>]) | <DocumentSpec>)
+    <IpmlId> [<RelatedSpec>] [<ContType>] [<ExpiryTime>] [<Forwarded>]
+    [<Importance>] [<IncompleteCopy>] [<Language>] [<Priority>] [<ReplyId>]
+    [<ReplyTime>] [<Sensitivity>] [<Subject>] [<SubmitTime>] [<UserInfo>]
+```
+
+---
+
+<sup>10)</sup> In case of MHS the IPM is encoded according to ASN.1 BER.
+
+```
+
+<ExtendSubFunctionKeywords> :=
+    <EncodeIPMExtension> | <DecodeIPMExtension>
+
+<EncodeIPMExtension> :=
+    <EncodeIPMSubFunction>
+    ((<Document> <Convert> [<Type>]) | <DocumentSpec>) <Message>
+    <S-RecipientSpec> [<S-OriginatorSpec>] <IpmlId> [<ContType>] [<ExpiryTime>]
+    [<Importance>] [<Priority>] [<RelatedSpec>] [<ReplyId>] [<ReplyTime>]
+    <S-Originator> [<Sensitivity>] [<Subject>] [<UserInfo>]
+
+<DecodeIPMExtension> :=
+    <DecodeIPMSubFunction>
+    <Message> ((<Document> <Convert> <Type>) | <DocumentSpec>)
+    <S-RecipientSpec> [<S-OriginatorSpec>] <IpmlId> [<ContType>] [<ExpiryTime>]
+    [<Forwarded>] [<Importance>] [<Language>] [<Priority>] [<RelatedSpec>]
+    [<ReplyId>] [<ReplyTime>] [<Sensitivity>] [<Subject>] [<UserInfo>]
+
+```
+
+Table 99 describes the additional syntax elements for the E-Mail services. For a mapping of MHS service elements to the syntax elements used in this Recommendation refer to Table 112 in 16.6.
+
+### 16.2 Text Based Encoding
+
+#### 16.2.1 Mapping of Keywords
+
+See Table 100.
+
+#### 16.2.2 Encoding of Parameters
+
+See also section 6.4.4 for the encoding of non service dependent parameters used.
+
+##### 16.2.2.1 Service-id-parameter
+
+The Service-id parameter is encoded as STRING set to the constant value "EMAIL".
+
+*Syntax:*
+
+```
+
+<Service-id-parameter> :=      "EMAIL"
+
+```
+
+##### 16.2.2.2 Type-id-parameter
+
+The Type-id-parameter is encoded as STRING set to one of the following values:
+
+|             |                                                                                                     |
+|-------------|-----------------------------------------------------------------------------------------------------|
+| "STD"       | IA5 Text body part                                                                                  |
+| "TELETEX"   | Teletex body part                                                                                   |
+| "G3FAX"     | Telefax Group 3 body part                                                                           |
+| "G4CLASS1"  | Telefax Group 4 body part                                                                           |
+| "VIDEOTEX"  | Videotex body part                                                                                  |
+| "MESSAGE"   | Body part contains an IPM (consisting of heading and bodyparts) as transferred by the E-Mail system |
+| "BILATERAL" | Bilateral defined body part contents                                                                |
+| "NATIONAL"  | National defined body part contents                                                                 |
+| "ODA"       | ODA body part                                                                                       |
+
+*Syntax:*
+
+```
+
+<Type-id-parameter> :=      "STD" | "TELETEX" | "G3FAX" | "G4CLASS1" | "VIDEOTEX" | "MESSAGE" |
+                             "BILATERAL" | "NATIONAL" | "ODA"11).
+
+```
+
+<sup>11)</sup> For MHS ITU-T Recommendation X.420 defines a set of parameters related to each body part. These parameters are transferred by using the Filespec-parameter (see section 16.2.2.8).
+
+TABLE 99/T.611
+
+###### **Additional syntax elements for E-Mail services**
+
+| Syntax element                            | Purpose                                                                                                                                          |
+|-------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------|
+| <Alternate>                               | Specifies whether alternate recipient(s) are allowed                                                                                             |
+| <ContType>                                | Specifies the content type of the message exchanged                                                                                              |
+| <Convert>                                 | Specifies the Transfer Format to be used                                                                                                         |
+| <DecodeIPMSubFunction>                    | Identifies the DecodeIPM Subfunction                                                                                                             |
+| <DiscloRec>                               | Recipients disclosure                                                                                                                            |
+| <Document>, <DocumentSpec>                | Specifies the document or the documents to be sent or being received (or to be exchanged with the EncodeIPM and DecodeIPM subfunctions)          |
+| <EncodeIPMSubFunction>                    | Identifies the EncodeIPM Subfunction                                                                                                             |
+| <ExpiryTime>                              | Date/Time of expiration of the message (Expiry Time)                                                                                             |
+| <Forwarded>                               | Autoforwarded indication                                                                                                                         |
+| <ImplicitConv>                            | Implicit conversion                                                                                                                              |
+| <Importance>                              | Importance of the message contents                                                                                                               |
+| <IncompleteCopy>                          | Reflects the MHS incomplete copy indication                                                                                                      |
+| <IpmlId>                                  | Message ID                                                                                                                                       |
+| <Language>                                | Identification of the language used                                                                                                              |
+| <Message>                                 | Path to the ASN.1 BER coded message of the EncodeIPM and DecodeIPM subfunctions                                                                  |
+| <MsgSubId>                                | Message submission identifier, returned by the E-Mail service provider after it has accepted the request                                         |
+| <Priority>                                | Priority of the message contents                                                                                                                 |
+| <R-OriginatorSpec>,<br><S-OriginatorSpec> | Path to the file containing the address specifications of the originator, authorizing user(s) and reply-to user(s) of the message                |
+| <R-RecipientSpec>,<br><S-RecipientSpec>   | Path to the file containing the address specifications of all intended recipients of the message, i.e. primary, copy and blind copy recipient(s) |
+| <RelatedSpec>                             | Path name of the file containing the Relatedspecs of all messages related to the present one                                                     |
+| <ReplyId>                                 | ID of the message, for which this one is a response                                                                                              |
+| <ReplyTime>                               | Date-Time by when the recipient(s) of the message should reply to the authorizing users (Reply Time)                                             |
+| <Sensitivity>                             | Sensitivity of the message contents                                                                                                              |
+| <Subject>                                 | Subject the message is referring to                                                                                                              |
+| <SubmitTime>                              | Date-Time at which the E-Mail service provider processed the request (Message Submission Time)                                                   |
+| <Type>                                    | Specifies the Transmission Format used                                                                                                           |
+| <UserInfo>                                | User-provided optional envelope identifier that is forwarded along with the message. Can be used for user-specific identification purposes       |
+
+TABLE 100/T.611
+
+###### **Text Based Encoding of additional syntax elements for E-Mail services**
+
+(A ↵ stands for new line)
+
+| Syntax Element         | Keyword/Parameter Pair                          |
+|------------------------|-------------------------------------------------|
+| <Alternate>            | "ALTERNATE" ":" <Boolean-parameter> ↵           |
+| <ContType>             | "CONT-TYPE" ":" <Content-type-parameter> ↵      |
+| <Convert>              | "CONVERT" ":" <Convert-id-parameter> ↵          |
+| <DecodeIPMSubFunction> | "SUBFUNC" ":" "DecodeIPM" ↵                     |
+| <DiscloRec>            | "DISCLO-REC" ":" <Boolean-parameter> ↵          |
+| <Document>             | "FILENAME" ":" <File-parameter> ↵               |
+| <DocumentSpec>         | "FILENAME" ":" "@" <File-of-filespec> ↵         |
+| <EncodeIPMSubFunction> | "SUBFUNC" ":" "EncodeIPM" ↵                     |
+| <ExpiryTime>           | "EXPIRYTIME" ":" <Date-time-parameter> ↵        |
+| <Forwarded>            | "FORWARDED" ":" <Boolean-parameter> ↵           |
+| <ImplicitConv>         | "IMPLICIT-CONV" ":" <Boolean-parameter> ↵       |
+| <Importance>           | "IMPORTANCE" ":" <Importance-parameter> ↵       |
+| <IncompleteCopy>       | "INC-COPY" ":" <Boolean-parameter> ↵            |
+| <IpmId>                | "IPM-ID" ":" <Ipm-id-parameter> ↵               |
+| <Language>             | "LANGUAGE" ":" <Language-id-parameter> ↵        |
+| <Message>              | "MESSAGE" ":" <Path-parameter> ↵                |
+| <MsgSubId>             | "MSG-SUB-ID" ":" <Msg-sub-id-parameter> ↵       |
+| <Priority>             | "PRIORITY" ":" <Priority-parameter> ↵           |
+| <R-OriginatorSpec>     | "ADDRESS" ":" "@" <File-of-originatorspec> ↵    |
+| <R-RecipientSpec>      | "RECIPIENT" ":" "@" <File-of-r-recipientspec> ↵ |
+| <RelatedSpec>          | "RELATED" ":" "@" <File-of-relatedspec> ↵       |
+| <ReplyId>              | "REPLYID" ":" <Ipm-id-parameter> ↵              |
+| <ReplyTime>            | "REPLYTIME" ":" <Date-time-parameter> ↵         |
+| <S-OriginatorSpec>     | "ORIGINATOR" ":" "@" <File-of-originatorspec> ↵ |
+| <S-RecipientSpec>      | "ADDRESS" ":" "@" <File-of-s-recipientspec> ↵   |
+| <Sensitivity>          | "SENSITIVITY" ":" <Sensitivity-parameter> ↵     |
+| <Subject>              | "SUBJECT" ":" <Subject-parameter> ↵             |
+| <SubmitTime>           | "SUBMITTIME" ":" <Date-time-parameter> ↵        |
+| <Type>                 | "TYPE" ":" <Type-id-parameter> ↵                |
+| <UserInfo>             | "USERINFO" ":" <Userinfo-parameter> ↵           |
+
+##### 16.2.2.3 Convert-id-parameter
+
+The Convert-id-parameter is encoded as STRING set to one of the following values:
+
+|            |                                                                                       |
+|------------|---------------------------------------------------------------------------------------|
+| "ASCII"    | APPLI/COM Extended ASCII                                                              |
+| "ASCII437" | APPLI/COM Extended ASCII                                                              |
+| "T.50"     | APPLI/COM Standard ASCII                                                              |
+| "T.61"     | APPLI/COM Teletex format                                                              |
+| "TIFF"     | APPLI/COM TIFF                                                                        |
+| "VOID"     | No conversion to be done                                                              |
+| "PROBE"    | Specifies an empty document (i.e. no document at all) for delivery testing procedures |
+
+The use of the Convert-id-parameter also depends on the Type-id selected. Table 101 depicts this.
+
+TABLE 101/T.611
+
+###### Permitted Convert-id assignments dependent on Type-id
+
+| Type-id                                                                                               | Convert-id for outgoing traffic                        | Convert-id for incoming traffic |
+|-------------------------------------------------------------------------------------------------------|--------------------------------------------------------|---------------------------------|
+| STD                                                                                                   | T.50                                                   |                                 |
+| TELETEX                                                                                               | ASCII, ASCII <sub>xxx</sub> <sup>a)</sup> , T.50, T.61 |                                 |
+| G3FAX, G4CLASS1                                                                                       | ASCII, ASCII <sub>xxx</sub> , T.50, TIFF               | TIFF                            |
+| VIDEOTEX, MESSAGE, BILATERAL, NATIONAL, ODA                                                           | VOID                                                   |                                 |
+| a) xxx stands for a code-page, declared in the ICE, e.g. ASCII437 if code-page 437 has been declared. |                                                        |                                 |
+
+*Syntax:*
+
+|                           |                                                                                         |
+|---------------------------|-----------------------------------------------------------------------------------------|
+| <Convert-id-parameter> := | <Convert-probe>   <Convert-std>   <Convert-ttx>   <Convert-img>   <Convert-bin>         |
+| <Convert-probe> :=        | "PROBE"<br>-- <i>Special mode, where no documents are transmitted; can only be sent</i> |
+| <Convert-std> :=          | "T.50"                                                                                  |
+| <Convert-ttx> :=          | <Ascii>   "T.50"   "T.61"                                                               |
+| <Convert-img> :=          | <Ascii>   "T.50"   "TIFF"                                                               |
+| <Convert-bin> :=          | "VOID"                                                                                  |
+| <Ascii> :=                | "ASCII"   STRING ("ASCII" + Code-page)                                                  |
+| <Code-page> :=            | <digit> <digit> <digit>                                                                 |
+| <digit> :=                | "0"   ...   "9"                                                                         |
+
+##### 16.2.2.4 MHS Addresses
+
+MHS Addresses are referenced by the Originatorspec-parameter, R-Recipientspec-parameter and S-Recipientspec-parameter or by the Ipm-id-parameter (see 16.2.2.5, 16.2.2.6 and 16.2.2.11).
+
+The syntax of the MHS Addresses, namely Mhs-or-descriptor, Mhs-or-name, Mhs-dl-name and Mhs-or-address, is specified below.
+
+The MHS-or-address is encoded as STRING representing a compilation of address elements, each specifying a part of the address.
+
+An address element is composed of an address field identifier, followed by a separator ("=" sign) and the address field attribute.
+
+Table 102 below lists the address field identifiers predefined for MHS services within this Recommendation<sup>12)</sup>.
+
+NOTE – The addressing scheme of Table 102 can also be used for other E-Mail environments if appropriate. The creation of additional, not predefined address elements is possible using the formal BNF-style syntax description of the <Private-addr-element> below.
+
+TABLE 102/T.611  
+Address field identifiers and attributes
+
+| Address field identifier | Address field attribute  | Maximum attribute field length |
+|--------------------------|--------------------------|--------------------------------|
+| C                        | CountryName              | 3                              |
+| A                        | AdministrationDomainName | 16                             |
+| P                        | PrivateDomainName        | 16                             |
+| O                        | OrganizationName         | 64                             |
+| OUn (0 ≤ n ≤ 4)          | OrganizationUnitName     | 32                             |
+| Q                        | GenerationQualifier      | 3                              |
+| S                        | Surname                  | 40                             |
+| G                        | GivenName                | 16                             |
+| I                        | Initials                 | 5                              |
+| X121                     | X.121Address             | 16                             |
+| T-ID                     | TerminalIdentifier       | 24                             |
+| PD-BOX                   | PostalOfficeBoxAddress   | 60                             |
+
+*Syntax:*
+
+-- Syntax of <Mhs-or-address> (referenced by other parameter syntaxes)
+
+<Mhs-or-address> :=
+
+"/" <Mandatory-address-element> {"/" <Mandatory-address-element>  
+ {"/" <Optional-address-element>} {"/" <Private-addr-element>}  
+ -- for use with MHS systems  
+ -- at least one <Mandatory-address-element> shall be present
+
+<Mandatory-address-element> :=
+
+("C" "=" STRING (SIZE(1..3))) | -- CountryName  
+ ("A" "=" STRING (SIZE(1..16))) | -- AdministrationDomainName  
+ ("P" "=" STRING (SIZE(1..16))) | -- PrivateDomainName  
+ ("O" "=" STRING (SIZE(1..64))) | -- OrganizationName  
+ -- See also Table 102 for assignments
+
+<Optional-address-element> :=
+
+("OU"<n> "=" STRING (SIZE(1..32))) | -- OrganisationUnitName  
+ ("Q" "=" STRING (SIZE(1..3))) | -- GenerationQualifier  
+ ("S" "=" STRING (SIZE(1..40))) | -- Surname
+
+<sup>12)</sup> Each address field identifier addresses an O/R-Name attribute as specified in ITU-T Recommendation X.402.
+
+```
+
+("G" "=" STRING (SIZE(1..16))) |      -- GivenName
+("I" "=" STRING (SIZE(1..5))) |       -- Initials
+("X121" "=" STRING (SIZE(1..16))) |   -- X.121 Address
+("T-ID" "=" STRING (SIZE(1..24))) |   -- Terminal identifier
+("PD-BOX" "=" STRING (SIZE(1..60))) | -- PostalOfficeBoxAddress
+-- See also Table 102 for assignments
+
+<n> :=                                "0" | ... | "4"
+
+<Private-addr-element> :=              <Field-identifier> "=" <Field-attribute>
+-- private or additional defined address element
+
+-- Syntax of <Mhs-or-descriptor> (referenced by other parameter syntaxes)
+
+<Mhs-or-descriptor> :=                (<Mhs-or-name> ["+" [<Mhs-free-name>] ["+" <Mhs-phone-number>]]) |
+                                       ("+" <Mhs-free-name> ["+" <Mhs-phone-number>])
+
+<Mhs-free-name> :=                    STRING (SIZE(1..64))
+
+<Mhs-phone-number> :=                 STRING (SIZE(1..32))
+
+-- Syntax of <Mhs-or-name> (referenced by other parameter syntaxes)
+
+<Mhs-or-name> :=                      (<Mhs-or-address> ["+" <Mhs-dl-name>]) | ("+" <Mhs-dl-name>)
+
+<Mhs-dl-name> :=                      STRING (SIZE(1..64))
+-- stands for Distribution List name according to ITU-T
+-- Recommendation X.402
+
+```
+
+NOTE – The <Mhs-dl-name> is different from the <Alias> used in some syntaxes, since the alias is expanded locally (in the CA) whereas the <Mhs-dl-name> is expanded by the MTS.
+
+##### 16.2.2.5 File-of-originatorspec
+
+The File-of-originatorspec construction specifies the originators of the message. It is encoded as PATH. The path given shall address a file containing one or more Originatorspec-parameter(s).
+
+*Syntax:*
+
+```
+
+<File-of-originatorspec> :=          PATH
+-- The path points to a file containing one or more
+-- <Originatorspec-parameter>s
+
+<Originatorspec-parameter> := 
+<Addr-descriptor> | <Mhs-or-descriptor> "," <O-type>
+-- for definition of <Mhs-or-descriptor> see 16.2.2.4
+
+<Addr-descriptor> :=                STRING
+-- Contents as required by the underlying (non-MHS) E-Mail system;
+-- shall not contain "," characters
+
+<O-type> :=                         "Authorizing" | "Originator" | "ReplyTo"
+
+```
+
+##### 16.2.2.6 File-of-r-recipientspec and File-of-s-recipientspec
+
+The File-of-r-recipientspec and File-of-s-recipientspec constructions specify the recipients of the message. They are encoded as PATH. The path given shall address a file containing one or more R-recipientspec-parameter(s) or S-recipientspec-parameter(s) respectively.
+
+*Syntax:*
+
+```
+
+<File-of-r-recipientspec> :=        PATH
+-- The path points to a file containing one or more
+-- <R-recipientspec-parameter>s
+
+```
+
+```
+
+<File-of-s-recipientspec> :=      PATH
+-- The path points to a file containing one ore more
+-- <S-recipientspec-parameter>s
+
+<R-recipientspec-parameter> :=
+    <Addr-descriptor> | <Mhs-or-descriptor>
+    "," <R-type> ["," [<Reply>] ["," [<Notify>] ["," <Report>] ] ]
+-- Receiving side
+-- for definition of the <Mhs-or-descriptor> see 16.2.2.4
+
+<S-recipientspec-parameter> :=
+    ("&" <Alias>) | <Addr-descriptor> | <Mhs-or-descriptor>
+    "," <S-type> ["," [<Reply>] ["," [<Notify>] ["," <Report>] ] ]
+-- Sending side may specify an (local) alias instead of a descriptor
+-- for definition of the <Mhs-or-descriptor> see 16.2.2.4
+
+<Alias> :=
+    STRING
+-- The Alias shall not contain "," or ";" characters!
+
+<Addr-descriptor> :=
+    STRING
+-- Contents as required by underlying (non-MHS) E-Mail system;
+-- shall not contain ";" characters
+
+<R-type> :=
+    "Primary" | "Copy" | "Blind" | "Intended"
+
+<S-type> :=
+    "Primary" | "Copy" | "Blind"
+
+<Reply> :=
+    "NoReply" | "Reply"
+-- NoReply is taken as default if not specified
+
+<Notify> :=
+    "NoNotify" | "NotifyNotReceived" | "NotifyReceived" | "NotifyExplicit"
+-- NoNotify is taken as default if not specified
+
+<Report> :=
+    "NoReport" | "BasicReport" | "ConfirmedReport"13)
+-- NoReport is taken as default if not specified
+
+```
+
+##### 16.2.2.7 File-of-relatedspec
+
+The File-of-relatedspec construction specifies IPM-IDs a message is related to. It is encoded as PATH. The path given shall address a file containing one ore more Relatedspec-parameter(s).
+
+*Syntax:*
+
+```
+
+<File-of-relatedspec> :=      PATH
+-- The path points to a file containing one ore more
+-- <Relatedspec-parameter>s
+
+<Relatedspec-parameter> :=
+    <Ipm-Id-parameter> "," <Relation>
+-- See 16.2.2.11 for definition of the Ipm-id-parameter
+
+<Relation> :=
+    "Reference" | "Obsolete"
+
+```
+
+##### 16.2.2.8 File-of-filespec and File-parameter
+
+The File-of-filespec parameter is encoded as PATH which points to a file containing Filespec-parameters, which contain the File-parameter. The File-parameter itself is also encoded as PATH, which points to the file transferred.
+
+If the special Convert-id-parameter "PROBE" is specified, the File-parameter may be omitted (see also 16.2.2.3).
+
+<sup>13)</sup> In case of MHS, "BasicReport" maps to non-delivery-report and "ConfirmedReport" maps to report of ITU-T Recommendation X.411.
+
+*Syntax:*
+
+```
+<File-of-filespec> :=          PATH
+                             -- The path points to a file containing one ore more
+                             -- <Filespec-parameter>s
+
+<Filespec-parameter> :=      <File-parameter> "," <File-conv>
+                             [ ["," <File-type>] ["," <Body-part-parameter>] ]
+
+<File-parameter> :=          PATH
+                             -- Path to the file transferred
+
+<File-conv> :=                <Convert-id-parameter>
+                             -- Specifies the Transfer Format of the file
+
+<File-type> :=                <Type-id-parameter>
+                             -- Specifies the Transmission Format of the file
+
+<Body-part-parameter> :=     STRING
+                             -- Syntax left open for further study
+```
+
+##### 16.2.2.9 Content-type-parameter
+
+The Content-type-parameter is encoded as STRING set to one of the following values:
+
+|            |                                                                                                            |
+|------------|------------------------------------------------------------------------------------------------------------|
+| "mhsIPM84" | Interpersonal Message (IPM) according to P2 protocol as defined per ITU-T Recommendation X.420 (1984)      |
+| "mhsIPM88" | Interpersonal Message (IPM) according to P2 protocol as defined per ITU-T Recommendation X.420 (1988)      |
+| "mhsIPN84" | Interpersonal Notification (IPN) according to P2 protocol as defined per ITU-T Recommendation X.420 (1984) |
+| "mhsIPN88" | Interpersonal Notification (IPN) according to P2 protocol as defined per ITU-T Recommendation X.420 (1988) |
+| "mhsDR"    | Delivery Report (DR) as defined per ITU-T Recommendation X.420                                             |
+| "cmcIPM"   | Reserved for Interpersonal Messages (IPM) conforming to the Common Messaging Call E-Mail interface         |
+| "cmcIPN"   | Reserved for Interpersonal Notifications (IPN) conforming to the Common Messaging Call E-Mail interface    |
+| "cmcDR"    | Reserved for Delivery Reports (DR) conforming to the Common Messaging Call E-Mail interface                |
+| any other  | Reserved for further study                                                                                 |
+
+*Syntax:*
+
+```
+<Content-type-parameter> :=  "mhsIPM84" | "mhsIPM88" | "mhsIPN84" | "mhsIPN88" | "mhsDR"
+                             | "cmcIPM" | "cmcIPN" | "cmcDR"
+```
+
+##### 16.2.2.10 Importance-parameter
+
+The Importance-parameter is encoded as NUMERIC-STRING set to one of the following values:
+
+|     |                  |
+|-----|------------------|
+| "0" | low              |
+| "1" | normal (default) |
+| "2" | high             |
+
+*Syntax:*
+
+```
+<Importance-parameter> :=  "0" | ... | "2"
+```
+
+##### 16.2.2.11 Ipm-id-parameter
+
+The Ipm-id-parameter is encoded as STRING.
+
+In MHS based systems it is a construct of two components:
+
+- a unique, user relative identifier (a local identifier);
+- an optional O/R Address which identifies the user.
+
+*Syntax:*
+
+```
+<Ipm-id-parameter> :=          <Free-ipm-id> | <Mhs-ipm-id>
+-- for definition of the <Mhs-or-descriptor> see 16.2.2.4
+
+<Free-ipm-id> :=                STRING
+-- Contents as required by underlying (non-MHS) E-Mail system
+-- The string shall not contain ", " or ";" characters
+
+<Mhs-ipm-id> :=                 <Local-ipm-id> ["," <Mhs-or-address>]
+-- for use in MHS systems
+-- for definition of the <Mhs-or-address> see 16.2.2.4
+
+<Local-ipm-id> :=               STRING (SIZE(1..64))
+-- The string shall not contain ", " or ";" characters
+```
+
+##### 16.2.2.12 Language-id-parameter
+
+The Language-id-parameter is encoded as STRING between 2 and 5 characters long. For assignment of the language code for MHS refer to ISO 639.2
+
+*Syntax:*
+
+```
+<Language-id-parameter> :=     STRING (SIZE(2..5))
+```
+
+##### 16.2.2.13 Msg-sub-id-parameter
+
+The Msg-sub-id-parameter is encoded as STRING. The Msg-sub-id-parameter identifies uniquely and unambiguously the message submission. It is generated by the E-Mail system<sup>14</sup>.
+
+*Syntax:*
+
+```
+<Msg-sub-id-parameter> :=      <Free-sub-id> | <Mhs-sub-id>
+
+<Free-sub-id> :=               STRING
+-- For use in non-MHS systems
+
+<Mhs-sub-id> :=                <Global-id> "," <Local-id>
+-- For use in MHS systems
+
+<Global-id> :=                 "/" "C" "=" STRING (SIZE(1..3))      -- CountryName
+                              "/" "A" "=" STRING (SIZE(1..16))      -- AdministrationDomainName
+                              [ "/" "P" "=" STRING (SIZE(1..16)) ]  -- PrivateDomainName
+                              -- see also definition of <Mhs-or-address>, 16.2.2.4
+
+<Local-id> :=                  STRING (SIZE(1..32))
+```
+
+##### 16.2.2.14 Priority-parameter
+
+The Priority-parameter is encoded as NUMERIC-STRING set to one of the following values:
+
+- |     |                  |
+|-----|------------------|
+| "0" | normal (default) |
+| "1" | non-urgent       |
+| "2" | urgent           |
+
+---
+
+<sup>14</sup> In case of MHS, the Msg-sub-id-parameter corresponds to the MPDUIdentifier (ITU-T Recommendation X.411 of 1984), renamed MTSIdentifier in the 1988 version of the ITU-T Recommendation X.411.
+
+*Syntax:*
+
+<Priority-parameter> := "0" | "1" | "2"
+
+##### **16.2.2.15 Subject-parameter**
+
+The Subject-parameter is encoded as STRING.
+
+*Syntax:*
+
+<Subject-parameter> := STRING (SIZE(1..128))
+
+##### **16.2.2.16 Sensitivity-parameter**
+
+The Sensitivity-parameter is encoded as NUMERIC-STRING set to one of the following values:
+
+|     |                                    |
+|-----|------------------------------------|
+| "0" | no sensitivity specified (default) |
+| "1" | personal                           |
+| "2" | private                            |
+| "3" | company confidential               |
+
+*Syntax:*
+
+<Sensitivity-parameter> := "0" | ... | "3"
+
+##### **16.2.2.17 Userinfo-parameter**
+
+The Userinfo-parameter is encoded as STRING.
+
+*Syntax:*
+
+<Userinfo-parameter> := STRING (SIZE(1..16))
+
+### **16.3 Interpersonal Messaging**
+
+#### **16.3.1 Function: Send and SendAck**
+
+The Response TDD of the SendAck function shall be generated by the CA as soon as the document (the message) has been submitted to the E-Mail provider of the originator and the E-Mail provider has returned the <MsgSubId> to the CA. In other words: the submission is acknowledged, not the transmission of the message. See Tables 103 and 104.
+
+#### **16.3.2 Function: Receive**
+
+See Table 105.
+
+#### **16.3.3 Function: EncodeIPM and DecodeIPM**
+
+The EncodeIPM and DecodeIPM TDDs allow an LA to encode or decode a complete IPM - containing heading and body parts - into/from a "MESSAGE" type body part (see 16.2.2.2)
+
+The encoding/decoding procedure requires that the LA provides a TDD containing syntax elements referring to the heading of the IPM to be encoded/decoded as well as syntax elements launching the encode/decode operation itself. Table 106 shows the EncodeIPM TDD extensions to the <ExtendTDD>, Table 107 shows the DecodeIPM TDD extensions.
+
+TABLE 103/T.611
+
+##### **Additional functionality of the <SendTDD> for access to E-Mail services**
+
+| Syntax Element     | C | T | I/O | Text Based Encoding |                                |            | Comment                                                                   |
+|--------------------|---|---|-----|---------------------|--------------------------------|------------|---------------------------------------------------------------------------|
+|                    |   |   |     | Keyword             | Parameter                      | Default    |                                                                           |
+| <IpmId>            | B | m | I   | IPM-ID              | <Ipm-id-parameter>             | –          | Message identifier                                                        |
+| <S-RecipientSpec>  | B | m | I   | ADDRESS             | "@" <File-of-s-recipient-spec> | –          | Path of the file containing the Recipientspecs of all intended recipients |
+| <S-OriginatorSpec> | B | m | I   | ORIGINATOR          | "@" <File-of-originator-spec>  | –          | Path name of the file containing the originator and authorising users     |
+| <Alternate>        | B | o | I   | ALTERNATE           | <Boolean-parameter>            | "No"       | Alternate recipient(s) allowed                                            |
+| <ContType>         | B | o | I   | CONT-TYPE           | <Content-type-parameter>       | "mhsIPM84" | Content Type                                                              |
+| <DiscloRec>        | B | o | I   | DISCLO-REC          | <Boolean-parameter>            | "No"       | Recipient(s) disclosure                                                   |
+| <ExpiryTime>       | B | o | I   | EXPIRYTIME          | <Date-time-parameter>          | –          | Expiration of the message (Expiry Time)                                   |
+| <ImplicitConv>     | B | o | I   | IMPLICIT-CONV       | <Boolean-parameter>            | "Yes"      | Implicit conversion                                                       |
+| <Importance>       | B | o | I   | IMPORTANCE          | <Importance-parameter>         | "1"        | Importance of the contents                                                |
+| <Language>         | B | o | I   | LANGUAGE            | <Language-id-parameter>        | –          | Identification of the language used                                       |
+| <Priority>         | B | o | I   | PRIORITY            | <Priority-parameter>           | "0"        | Priority of the contents                                                  |
+
+TABLE 103/T.611 (*end*)
+
+##### **Additional functionality of the <SendTDD> for access to E-Mail services**
+
+| Syntax Element         | C | T | I/O | Text Based Encoding |                           |         | Comment                                                                                              |
+|------------------------|---|---|-----|---------------------|---------------------------|---------|------------------------------------------------------------------------------------------------------|
+|                        |   |   |     | Keyword             | Parameter                 | Default |                                                                                                      |
+| <RelatedSpec>          | B | o | I   | RELATED             | "@" <File-of-Relatedspec> | –       | Path name of the file containing the Relatedspecs of all messages related to the present one         |
+| <ReplyId>              | B | o | I   | REPLYID             | <Ipm-id-parameter>        | –       | ID of the message, for which this one is a response                                                  |
+| <ReplyTime>            | B | o | I   | REPLYTIME           | <Date-time-parameter>     | –       | Date-Time by when the recipient(s) of the message should reply to the authorizing users (Reply Time) |
+| <Sensitivity>          | B | o | I   | SENSITIVITY         | <Sensitivity-parameter>   | "0"     | Sensitivity of the contents                                                                          |
+| <Subject>              | B | o | I   | SUBJECT             | <Subject-parameter>       | –       |                                                                                                      |
+| <Userinfo>             | + | o | I   | USERINFO            | <Userinfo-parameter>      | –       | User-provided optional envelope identifier                                                           |
+| Send only one file     |   |   |     |                     |                           |         |                                                                                                      |
+| <Convert>              | B | m | I   | CONVERT             | <Convert-id-parameter>    | –       | Transfer format of the outgoing file                                                                 |
+| <Document>             | B | m | I   | FILENAME            | <File-parameter>          | –       | Single file to be transmitted, delivered under the Transfer Format specified by the Convert keyword  |
+| <Type>                 | B | o | I   | TYPE                | <Type-id-parameter>       | "STD"   | Specifies the document type to be sent                                                               |
+| Send one or many files |   |   |     |                     |                           |         |                                                                                                      |
+| <DocumentSpec>         | + | m | I   | FILENAME            | "@" <File-of-filespec>    | –       | Specifies a list of files; uses a special syntax                                                     |
+
+TABLE 104/T.611
+
+##### **Additional functionality of the <SendAckTDD> for access to E-Mail services**
+
+| Syntax Element     | C | T | I/O | Text Based Encoding |                                |            | Comment                                                                                                  |
+|--------------------|---|---|-----|---------------------|--------------------------------|------------|----------------------------------------------------------------------------------------------------------|
+|                    |   |   |     | Keyword             | Parameter                      | Default    |                                                                                                          |
+| <IpmId>            | B | m | I   | IPM-ID              | <Ipm-id-parameter>             | –          | Message identifier                                                                                       |
+| <S-RecipientSpec>  | B | m | I   | ADDRESS             | "@" <File-of-s-recipient-spec> | –          | Path of the file containing the Recipientspecs of all intended recipients                                |
+| <S-OriginatorSpec> | B | m | I   | ORIGINATOR          | "@" <File-of-originator-spec>  | –          | Path name of the file containing the originator and authorizing users                                    |
+| <Alternate>        | B | o | I   | ALTERNATE           | <Boolean-parameter>            | "No"       | Alternate recipient(s) allowed                                                                           |
+| <ContType>         | B | o | I   | CONT-TYPE           | <Content-type-parameter>       | "mhsIPM84" | Content Type                                                                                             |
+| <DiscloRec>        | B | o | I   | DISCLO-REC          | <Boolean-parameter>            | "No"       | Recipient(s) disclosure                                                                                  |
+| <ExpiryTime>       | B | o | I   | EXPIRYTIME          | <Date-time-parameter>          | –          | Expiration of the message (Expiry Time)                                                                  |
+| <ImplicitConv>     | B | o | I   | IMPLICIT-CONV       | <Boolean-parameter>            | "Yes"      | Implicit conversion                                                                                      |
+| <Importance>       | B | o | I   | IMPORTANCE          | <Importance-parameter>         | "1"        | Importance of the contents                                                                               |
+| <Language>         | B | o | I   | LANGUAGE            | <Language-id-parameter>        | –          | Identification of the language used                                                                      |
+| <MsgSubId>         | B | o | O   | MSG-SUB-ID          | <Msg-sub-id-parameter>         | –          | Message submission identifier. Returned by the E-Mail service provider after it has accepted the request |
+| <Priority>         | B | o | I   | PRIORITY            | <Priority-parameter>           | "0"        | Priority of the contents                                                                                 |
+| <RelatedSpec>      | B | o | I   | RELATED             | "@" <File-of-Related-spec>     | –          | Path name of the file containing the Relatedspecs of all messages related to the present one             |
+| <ReplyId>          | B | o | I   | REPLYID             | <Ipm-id-parameter>             | –          | ID of the message, for which this one is a response                                                      |
+
+TABLE 104/T.611 (*end*)
+
+##### **Additional functionality of the <SendAckTDD> for access to E-Mail services**
+
+| Syntax Element         | C | T | I/O | Text Based Encoding |                         |         | Comment                                                                                              |
+|------------------------|---|---|-----|---------------------|-------------------------|---------|------------------------------------------------------------------------------------------------------|
+|                        |   |   |     | Keyword             | Parameter               | Default |                                                                                                      |
+| <ReplyTime>            | B | o | I   | REPLYTIME           | <Date-time-parameter>   | –       | Date-Time by when the recipient(s) of the message should reply to the authorizing users (Reply Time) |
+| <Sensitivity>          | B | o | I   | SENSITIVITY         | <Sensitivity-parameter> | "0"     | Sensitivity of the contents                                                                          |
+| <Subject>              | B | o | I   | SUBJECT             | <Subject-parameter>     | –       |                                                                                                      |
+| <SubmitTime>           | B | o | O   | SUBMITTIME          | <Date-time-parameter>   | –       | Date-time at which the request is processed by the E-Mail service provider                           |
+| <Userinfo>             | + | o | I   | USERINFO            | <Userinfo-parameter>    | –       | User-provided optional envelope identifier                                                           |
+| Send only one file     |   |   |     |                     |                         |         |                                                                                                      |
+| <Convert>              | B | m | I   | CONVERT             | <Convert-id-parameter>  | –       | Transfer format of the outgoing file                                                                 |
+| <Document>             | B | m | I   | FILENAME            | <File-parameter>        | –       | Single file to be transmitted, delivered under the Transfer Format specified by the Convert keyword. |
+| <Type>                 | B | o | I   | TYPE                | <Type-id-parameter>     | "STD"   | Specifies the document type to be sent                                                               |
+| Send one or many files |   |   |     |                     |                         |         |                                                                                                      |
+| <DocumentSpec>         | + | m | I   | FILENAME            | "@" <File-of-filespec>  | –       | Specifies a list of files; uses a special syntax                                                     |
+
+TABLE 105/T.611
+
+##### **Additional functionality of the <ReceiveTDD> for access to E-Mail services**
+
+| Syntax Element     | C | T | I/O | Text Based Encoding |                                |         | Comment                                                                                              |
+|--------------------|---|---|-----|---------------------|--------------------------------|---------|------------------------------------------------------------------------------------------------------|
+|                    |   |   |     | Keyword             | Parameter                      | Default |                                                                                                      |
+| <IpmId>            | B | m | O   | IPM-ID              | <Ipm-id-parameter>             | –       | Message identifier                                                                                   |
+| <R-RecipientSpec>  | B | m | I   | RECIPIENT           | "@" <File-of-r-recipient-spec> | –       | Path of the file containing the Recipientspecs of all intended recipients                            |
+| <R-OriginatorSpec> | B | m | I   | ADDRESS             | "@" <File-of-originator-spec>  | –       | Path name of the file containing the originator and authorizing users                                |
+| <ContType>         | B | o | O   | CONT-TYPE           | <Content-type-parameter>       | –       | Content Type                                                                                         |
+| <ExpiryTime>       | B | o | O   | EXPIRYTIME          | <Date-time-parameter>          | –       | Expiration of the message (Expiry Time)                                                              |
+| <Forwarded>        | B | o | O   | FORWARDED           | <Boolean-parameter>            | –       | Autoforwarded indication                                                                             |
+| <Importance>       | B | o | O   | IMPORTANCE          | <Importance-parameter>         | –       | Importance of the contents                                                                           |
+| <Language>         | B | o | O   | LANGUAGE            | <Language-id-parameter>        | –       | Identification of the language used                                                                  |
+| <Priority>         | B | o | O   | PRIORITY            | <Priority-parameter>           | –       | Priority of the contents                                                                             |
+| <RelatedSpec>      | B | o | I   | RELATED             | "@" <File-of-related-spec>     | –       | Path name of the file receiving the Relatedspecs of all messages related to the present one          |
+| <ReplyId>          | B | o | O   | REPLYID             | <Ipm-id-parameter>             | –       | ID of the message, for which this one is a response                                                  |
+| <ReplyTime>        | B | o | O   | REPLYTIME           | <Date-time-parameter>          | –       | Date-Time by when the recipient(s) of the message should reply to the authorizing users (Reply Time) |
+| <Sensitivity>      | B | o | O   | SENSITIVITY         | <Sensitivity-parameter>        | "0"     | Sensitivity of the contents                                                                          |
+| <Subject>          | B | o | O   | SUBJECT             | <Subject-parameter>            | –       |                                                                                                      |
+
+TABLE 105/T.611 (*end*)
+
+##### **Additional functionality of the <ReceiveTDD> for access to E-Mail services**
+
+| Syntax Element         | C | T | I/O | Text Based Encoding |                        |         | Comment                                                                                                                                                                                |
+|------------------------|---|---|-----|---------------------|------------------------|---------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+|                        |   |   |     | Keyword             | Parameter              | Default |                                                                                                                                                                                        |
+| <SubmitTime>           | B | o | O   | SUBMITTIME          | <Date-time-parameter>  | –       | Date-time at which the request is processed by the E-Mail service provider                                                                                                             |
+| <IncCopy>              | + | o | O   | INC-COPY            | <Boolean-parameter>    | –       | Incomplete copy indicator                                                                                                                                                              |
+| <Userinfo>             | + | o | O   | USERINFO            | <Userinfo-parameter>   | –       | User-provided optional envelope identifier                                                                                                                                             |
+| Only one file received |   |   |     |                     |                        |         |                                                                                                                                                                                        |
+| <Convert>              | B | m | O   | CONVERT             | <Convert-id-parameter> | –       | States the Transfer Format of the received file                                                                                                                                        |
+| <Document>             | B | m | I/O | FILENAME            | <File-parameter>       | –       | The filename may be pre-set by the LA on request. If only one file is received, the name shall be retained by the CA. If many files are received the name may be overwritten by the CA |
+| <Type>                 | B | o | O   | TYPE                | <Type-id-parameter>    | –       | Specifies the document type received                                                                                                                                                   |
+| Many files received    |   |   |     |                     |                        |         |                                                                                                                                                                                        |
+| <DocumentSpec>         | + | m | O   | FILENAME            | "@" <File-of-filespec> | –       | Specifies a list of files; uses a special syntax                                                                                                                                       |
+
+TABLE 106/T.611
+
+##### **Additional syntax elements for the <EncodeIPMExtension> of E-Mail services**
+
+| Syntax Element                                                             | C | T | I/O | Text Based Encoding |                               |            | Comment                                                                                              |
+|----------------------------------------------------------------------------|---|---|-----|---------------------|-------------------------------|------------|------------------------------------------------------------------------------------------------------|
+|                                                                            |   |   |     | Keyword             | Parameter                     | Default    |                                                                                                      |
+| Syntax elements belonging to the encode procedure itself (job description) |   |   |     |                     |                               |            |                                                                                                      |
+| <EncodeIPM-SubFunction>                                                    | B | m | I   | SUBFUNC             | "EncodeIPM"                   | –          |                                                                                                      |
+| <Message>                                                                  | B | m | I   | MESSAGE             | <Path-parameter>              | --         | Path to file that will receive the encoded IPM                                                       |
+| <Minor>                                                                    | + | o | O   | MINOR               | <Error-parameter>             | –          |                                                                                                      |
+| <Warning>                                                                  | + | o | O   | WARNING             | <Error-parameter>             | –          |                                                                                                      |
+| Only one body part shall be encoded                                        |   |   |     |                     |                               |            |                                                                                                      |
+| <Convert>                                                                  | B | m | I   | CONVERT             | <Convert-id-parameter>        | –          | Transfer format of the body part to be encoded                                                       |
+| <Document>                                                                 | B | m | I   | FILENAME            | <File-parameter>              | –          | Single body part to be encoded, delivered under the Transfer Format specified by the Convert keyword |
+| <Type>                                                                     | B | o | I   | TYPE                | <Type-id-parameter>           | "STD"      | Specifies the document type to be encoded                                                            |
+| One or many body parts shall be encoded                                    |   |   |     |                     |                               |            |                                                                                                      |
+| <DocumentSpec>                                                             | + | m | I   | FILENAME            | "@" <File-of-filespec>        | –          | Specifies a list of files; uses a special syntax                                                     |
+| Syntax elements holding the heading information for the IPM to be encoded  |   |   |     |                     |                               |            |                                                                                                      |
+| <IpmlId>                                                                   | B | m | I   | IPM-ID              | <Ipm-id-parameter>            | –          | Message identifier                                                                                   |
+| <S-RecipientSpec>                                                          | B | m | I   | ADDRESS             | "@" <File-of-s-recipientspec> | –          | Path of the file containing the Recipientspecs of all intended recipients                            |
+| <S-OriginatorSpec>                                                         | B | m | I   | ORIGINATOR          | "@" <File-of-originatorspec>  | –          | Path name of the file containing the originator and authorizing users                                |
+| <ContType>                                                                 | B | o | I   | CONT-TYPE           | <Content-type-parameter>      | "mhsIPM84" | Content Type                                                                                         |
+| <ExpiryTime>                                                               | B | o | I   | EXPIRYTIME          | <Date-time-parameter>         | –          | Expiration of the message                                                                            |
+
+TABLE 106/T.611 (*end*)
+
+##### **Additional syntax elements for the <EncodeIPMExtension> of E-Mail services**
+
+| Syntax Element | C | T | I/O | Text Based Encoding |                           |         | Comment                                                                                              |
+|----------------|---|---|-----|---------------------|---------------------------|---------|------------------------------------------------------------------------------------------------------|
+|                |   |   |     | Keyword             | Parameter                 | Default |                                                                                                      |
+| <Importance>   | B | o | I   | IMPORTANCE          | <Importance-parameter>    | "1"     | Importance of the contents                                                                           |
+| <Priority>     | B | o | I   | PRIORITY            | <Priority-parameter>      | "0"     | Priority of the contents                                                                             |
+| <RelatedSpec>  | B | o | I   | RELATED             | "@" <File-of-Relatedspec> | –       | Path name of the file containing the Relatedspecs of all messages related to the present one         |
+| <ReplyId>      | B | o | I   | REPLYID             | <Ipm-id-parameter>        | –       | ID of the message, for which this one is a response                                                  |
+| <ReplyTime>    | B | o | I   | REPLYTIME           | <Date-time-parameter>     | –       | Date-Time by when the recipient(s) of the message should reply to the authorizing users (Reply Time) |
+| <Sensitivity>  | B | o | I   | SENSITIVITY         | <Sensitivity-parameter>   | "0"     | Sensitivity of the contents                                                                          |
+| <Subject>      | B | o | I   | SUBJECT             | <Subject-parameter>       | –       |                                                                                                      |
+| <Userinfo>     | + | o | I   | USERINFO            | <Userinfo-parameter>      | –       | User-provided                                                                                        |
+
+TABLE 107/T.611
+
+##### **Additional syntax elements for the <DecodeIPMExtension> of E-Mail services**
+
+| Syntax Element                                                             | C | T | I/O | Text Based Encoding |                               |         | Comment                                                                                                                                                                                            |
+|----------------------------------------------------------------------------|---|---|-----|---------------------|-------------------------------|---------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+|                                                                            |   |   |     | Keyword             | Parameter                     | Default |                                                                                                                                                                                                    |
+| Syntax elements belonging to the decode procedure itself (job description) |   |   |     |                     |                               |         |                                                                                                                                                                                                    |
+| <DecodeIPM-SubFunction>                                                    | B | m | I   | SUBFUNC             | "DecodeIPM"                   | –       |                                                                                                                                                                                                    |
+| <Message>                                                                  | B | m | I   | MESSAGE             | <Path-parameter>              | –       | Path to file that holds the IPM to be decoded                                                                                                                                                      |
+| <Minor>                                                                    | + | o | O   | MINOR               | <Error-parameter>             | –       |                                                                                                                                                                                                    |
+| <Warning>                                                                  | + | o | O   | WARNING             | <Error-parameter>             | –       |                                                                                                                                                                                                    |
+| If only one body part is present                                           |   |   |     |                     |                               |         |                                                                                                                                                                                                    |
+| <Convert>                                                                  | B | m | O   | CONVERT             | <Convert-id-parameter>        | –       | States the Transfer Format of the decoded body part                                                                                                                                                |
+| <Document>                                                                 | B | m | O   | FILENAME            | <File-parameter>              | –       | The filename may be pre-set by the LA on request. If only one body part is available, the name shall be retained by the CA. If many body parts are available the name may be overwritten by the CA |
+| <Type>                                                                     | B | o | O   | TYPE                | <Type-id-parameter>           | –       | Specifies the document type received                                                                                                                                                               |
+| If many body parts are present                                             |   |   |     |                     |                               |         |                                                                                                                                                                                                    |
+| <DocumentSpec>                                                             | + | m | I   | FILENAME            | "@" <File-of-filespec>        | –       | Specifies a list of files; uses a special syntax                                                                                                                                                   |
+| Syntax elements receiving the heading information of the IPM to be decoded |   |   |     |                     |                               |         |                                                                                                                                                                                                    |
+| <IpmlId>                                                                   | B | m | O   | IPM-ID              | <Ipml-id-parameter>           | –       | Message identifier.                                                                                                                                                                                |
+| <R-RecipientSpec>                                                          | B | m | I   | RECIPIENT           | "@" <File-of-r-recipientspec> | –       | Path of the file containing the Recipientspecs of all intended recipients                                                                                                                          |
+
+TABLE 107/T.611 (*end*)
+
+##### **Additional syntax elements for the <DecodeIPMExtension> of E-Mail services**
+
+| Syntax Element     | C | T | I/O | Text Based Encoding |                              |         | Comment                                                                                              |
+|--------------------|---|---|-----|---------------------|------------------------------|---------|------------------------------------------------------------------------------------------------------|
+|                    |   |   |     | Keyword             | Parameter                    | Default |                                                                                                      |
+| <R-OriginatorSpec> | B | m | I   | ADDRESS             | "@" <File-of-originatorspec> | –       | Path name of the file containing the originator and authorizing users                                |
+| <ContType>         | B | o | O   | CONT-TYPE           | <Content-type-parameter>     | –       | Content Type                                                                                         |
+| <ExpiryTime>       | B | o | I   | EXPIRYTIME          | <Date-time-parameter>        | –       | Expiration of the message (Expiry Time)                                                              |
+| <Forwarded>        | B | o | O   | FORWARDED           | <Boolean-parameter>          | –       | Autoforwarded indication                                                                             |
+| <Importance>       | B | o | O   | IMPORTANCE          | <Importance-parameter>       | –       | Importance of the contents                                                                           |
+| <Language>         | B | o | O   | LANGUAGE            | <Language-id-parameter>      | –       | Identification of the language used                                                                  |
+| <Priority>         | B | o | O   | PRIORITY            | <Priority-parameter>         | –       | Priority of the contents                                                                             |
+| <RelatedSpec>      | B | o | I   | RELATED             | "@" <File-of-Relatedspec>    | –       | Path name of the file containing the Relatedspecs of all messages related to the present one         |
+| <ReplyId>          | B | o | O   | REPLYID             | <Ipm-id-parameter>           | –       | ID of the message, for which this one is a response                                                  |
+| <ReplyTime>        | B | o | O   | REPLYTIME           | <Date-time-parameter>        | –       | Date-Time by when the recipient(s) of the message should reply to the authorizing users (Reply Time) |
+| <Sensitivity>      | B | o | O   | SENSITIVITY         | <Sensitivity-parameter>      | "0"     | Sensitivity of the contents                                                                          |
+| <Subject>          | B | o | O   | SUBJECT             | <Subject-parameter>          | –       |                                                                                                      |
+| <Userinfo>         | + | o | O   | USERINFO            | <Userinfo-parameter>         | –       | User-provided                                                                                        |
+
+### 16.4 Interpersonal Notification
+
+An LA may transmit an Interpersonal Notification (IPN) with a Send TDD and may receive an IPN with the Receive TDD.
+
+The IPN is treated by the CA as a special document, called the IPN document, i.e, the CA expects from the LA a specially prepared file containing the IPN parameters, when an IPN has to be sent. The CA shall convert the IPN document into the format required by the E-Mail system and transmit it to the recipient. Conversely, the CA shall present an IPN document to the LA when it receives an IPN through the network.
+
+To differentiate between IPMs and IPNs (and DRs, see 16.5) the Content-type-parameter of the <ContType> syntax element is used (see also 16.2.2.9).
+
+The IPN document shall conform to the same syntactical rules as those applying to TDDs.
+
+The following subclauses describe the syntax and the text based encoding of the IPN document.
+
+#### 16.4.1 Syntax of IPN Document
+
+The IPN Document is defined for MHS and conforms to following BNF-style syntax (see Table 108).
+
+```
+<IPN-Document> := <NotifyType> <SubjectIPM> <ReceiptTime>  
+[<IPNOrigin>] [<PrefRecipient>] [<Reason>] [<AutoComment>] [<SupplmInfo>]
+```
+
+TABLE 108/T.611
+
+**Syntax elements of the IPN Document**
+
+| Syntax element  | Purpose                                                                                                                                                                                                |
+|-----------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| <AutoComment>   | Comment of the originator of this notification, if the related IPM was auto-forwarded; only used for non-receipt-notifications of type NRN-FORW                                                        |
+| <Reason>        | Identifies why the IPM related to this notification was discarded:<br>0: ipm-expired<br>1: ipm-obsolete<br>2: user-subscription-terminated<br>only used for non-receipt-notifications of type NRN-DISC |
+| <IPNOrigin>     | Identifies the originator of this notification                                                                                                                                                         |
+| <NotifyType>    | Type of the notification:<br>RN: receipt notification<br>NRN-DISC: non-receipt-notification (discarded)<br>NRN-FORW: non-receipt-notification (auto-forwarded)<br>OTHER: other notification types      |
+| <PrefRecipient> | The preferred recipient of the IPM related to this notification                                                                                                                                        |
+| <ReceiptTime>   | Identifies the time when the originator of this notification received the related IPM; only used for receipt notification (RN)                                                                         |
+| <SubjectIPM>    | Identifies the IPM related to this notification                                                                                                                                                        |
+| <SupplmInfo>    | Supplementary information of the originating MTA; only used for receipt-notifications (RN)                                                                                                             |
+
+#### 16.4.2 Text based Encoding
+
+##### 16.4.2.1 Mapping of Keywords
+
+See Table 109.
+
+TABLE 109/T.611
+
+##### Text Based Encoding of IPN syntax elements for E-Mail services
+
+(A ↵ stands for new line)
+
+| Syntax Element  | Keyword / Parameter Pair                                     |
+|-----------------|--------------------------------------------------------------|
+| <AutoComment>   | "AUTO-COMMENT" ":" STRING (SIZE(1..256)) ↵                   |
+| <Reason>        | "REASON" ":" "0"   "1"   "2" ↵                               |
+| <IPNOrigin>     | "IPN-ORIGIN" ":" <Mhs-or-descriptor> ↵                       |
+| <NotifyType>    | "NOTIFY-TYPE" ":" "RN"   "NRN-DISC"   "NRN-FORW"   "OTHER" ↵ |
+| <PrefRecipient> | "DISCLO-REC" ":" <Mhs-or-descriptor> ↵                       |
+| <ReceiptTime>   | "RECEIPT-TIME" ":" <Date-time-parameter> ↵                   |
+| <SubjectIPM>    | "SUBJECT-IPM" ":" "@" <Ipm-id-parameter> ↵                   |
+| <SupplmInfo>    | "SUPPLM-INFO" ":" STRING (SIZE(1..256)) ↵                    |
+
+##### 16.4.2.2 Encoding of Parameters
+
+For description of the text based encoding of:
+
+- <Mhs-or-descriptor> refer to 16.2.2.4
+- <Date-time-parameter> refer to 6.4.4.4
+- <Ipm-id-parameter> refer to 16.2.2.11
+
+### 16.5 Delivery Report
+
+An LA may receive a Delivery Report (DR) with the Receive TDD.
+
+The DR is treated by the CA as a special document, called the DR document. The CA shall present such a DR document to the LA when it receives a DR through the network.
+
+To differentiate between IPMs and DRs (and IPNs, see 16.4) the Content-type-parameter of the <ContType> syntax element is used (see also 16.2.2.9).
+
+The DR document delivered by the CA shall conform to exactly the same syntactical rules as applied to TDDs.
+
+The following subclauses describe the syntax and the text based encoding of the DR document.
+
+#### 16.5.1 Syntax of DR Document
+
+The DR Document is defined for MHS and conforms to following BNF-style syntax (see Table 110).
+
+<DR-Document> :=                   <ReportType> <ActRecipient> <MsgSubId> [<ReceiveTime>] [<Reason>]  
+                                           [<Diagnostic>] [<SupplmInfo>]
+
+TABLE 110/T.611  
+Syntax elements of the DR Document
+
+| Syntax element | Purpose                                                                                                                                             |
+|----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------|
+| <ActRecipient> | Identifies the actual recipient of the IPM related to this report                                                                                   |
+| <Diagnostic>   | Additional diagnostic information to the report as defined by ITU-T Recommendation X.411; only used for non-delivery reports (NDR)                  |
+| <MsgSubId>     | Identifies the IPM related to this report (MTSIdentifier)                                                                                           |
+| <Reason>       | Identifies why the IPM related to this report was not delivered as defined by ITU-T Recommendation X.411; only used for non-delivery reports (NDR); |
+| <ReceiveTime>  | Time at which the message was delivered (DeliveryTime); only used for delivery reports (DR)                                                         |
+| <ReportType>   | Type of the delivery report:<br>DR: delivery report<br>NDR: non-delivery report                                                                     |
+| <SupplmInfo>   | Supplementary information of the originating MTA                                                                                                    |
+
+#### 16.5.2 Text based Encoding
+
+##### 16.5.2.1 Mapping of Keywords
+
+See Table 111.
+
+TABLE 111/T.611  
+Text Based Encoding of DR syntax elements for E-Mail services  
+(A ↵ stands for new line)
+
+| Syntax Element | Keyword / Parameter Pair                  |
+|----------------|-------------------------------------------|
+| <ActRecipient> | "ACT-RECIPIENT" ":" <Mhs-or-name> ↵       |
+| <Diagnostic>   | "DIAGNOSTIC" ":" NUMERIC-STRING ↵         |
+| <MsgSubId>     | "MSG-SUB-ID" ":" <Msg-sub-id-parameter> ↵ |
+| <Reason>       | "REASON" ":" NUMERIC-STRING ↵             |
+| <ReceiveTime>  | "RCVTIME" ":" <Date-time-parameter> ↵     |
+| <ReportType>   | "REPORT-TYPE" ":" "DR"   "NDR" ↵          |
+| <SupplmInfo>   | "SUPPLM-INFO" ":" STRING (SIZE(1..256)) ↵ |
+
+##### 16.5.2.2 Encoding of Parameters
+
+For description of the text based encoding of:
+
+- <Mhs-or-name> refer to 16.2.2.4
+- <Msg-sub-id-parameter> refer to 16.2.2.13
+- <Date-time-parameter> refer to 6.4.4.4
+
+### 16.6 Mapping of MHS service elements
+
+Table 112 shows the mapping of MHS service elements as defined per ITU-T X.400-Series of Recommendation to the the syntax elements defined by this Recommendation. Listed are the corresponding keywords used in text based presentation of the TDDs and their support for a sending and/or receiving LA.
+
+TABLE 112/T.611
+
+#### Mapping of MHS service elements
+
+| MHS service element                      | Syntax element                           | Keyword               | Sending LA     | Receiving LA   |
+|------------------------------------------|------------------------------------------|-----------------------|----------------|----------------|
+| Alternate Recipient Allowed Indication   | <Alternate>                              | ALTERNATE             | Supported      | Not supported  |
+| Authorizing User's Indication            | <R-OriginatorSpec><br><S-OriginatorSpec> | ADDRESS<br>ORIGINATOR | –<br>Supported | Supported<br>– |
+| Auto-forwarded Message Indication        | <Forwarded>                              | FORWARDED             | Not supported  | Supported      |
+| Blind Copy Recipients Indication         | <R-RecipientSpec><br><S-RecipientSpec>   | RECIPIENT<br>ADDRESS  | –<br>Supported | Supported<br>– |
+| Content Type Indication                  | <ContType>                               | CONT-TYPE             | Supported      | Supported      |
+| Conversion Prohibition                   | <ImplicitConv>                           | IMPLICIT-CONV         | Supported      | Not supported  |
+| Cross Referencing Indication             | <RelatedSpec>                            | RELATED               | Supported      | Supported      |
+| Deferred Delivery Indication             | <SendTime>                               | SENDTIME              | Supported      | Not supported  |
+| Delivery Report Request                  | <R-RecipientSpec><br><S-RecipientSpec>   | RECIPIENT<br>ADDRESS  | –<br>Supported | Supported<br>– |
+| Delivery Time Indication                 | <ReceiveTime>                            | RCVTIME               | Not supported  | Supported      |
+| Disclosure of Other Recipients           | <DiscloRec>                              | DISCLO-REC            | Supported      | Not supported  |
+| Expiry Date Indication                   | <ExpiryTime>                             | EXPIRYTIME            | Supported      | Supported      |
+| Forwarded IP Message                     | <Type>                                   | TYPE                  | Supported      | Supported      |
+| Grade of Delivery Selection              | <Priority>                               | PRIORITY              | Supported      | Supported      |
+| Importance Indication                    | <Importance>                             | IMPORTANCE            | Supported      | Supported      |
+| Incomplete Copy Indication <sup>a)</sup> | <IncompleteCopy>                         | INC-COPY              | Not supported  | Supported      |
+| Intended Recipient Indication            | <R-RecipientSpec>                        | RECIPIENT             | Not supported  | Supported      |
+| IP Message Indication                    | <IpmlId>                                 | IPM-ID                | Supported      | Supported      |
+
+TABLE 112/T.611 (end)
+
+#### Mapping of MHS service elements
+
+| MHS service element                                                                                                                                                                                                                                                                                                                                                                                                                                                             | Syntax element                           | Keyword            | Sending LA              | Receiving LA   |
+|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------|--------------------|-------------------------|----------------|
+| Language Indication                                                                                                                                                                                                                                                                                                                                                                                                                                                             | <Language>                               | LANGUAGE           | Not supported           | Supported      |
+| Latest Delivery Indication <sup>a)</sup>                                                                                                                                                                                                                                                                                                                                                                                                                                        | <LastTime>                               | LASTTIME           | Supported               | Not supported  |
+| Message Identification <sup>a)</sup>                                                                                                                                                                                                                                                                                                                                                                                                                                            | <Userinfo>                               | USERINFO           | Supported               | Supported      |
+| Message Submission Identification                                                                                                                                                                                                                                                                                                                                                                                                                                               | <MsgSubId>                               | MSG-SUB-ID         | Supported <sup>b)</sup> | Not supported  |
+| Multi-Destination Delivery                                                                                                                                                                                                                                                                                                                                                                                                                                                      | <R-RecipientSpec><br><S-RecipientSpec>   | RECIPIENT ADDRESS  | –<br>Supported          | Supported<br>– |
+| Multi-Part Body                                                                                                                                                                                                                                                                                                                                                                                                                                                                 | implicit                                 | n/a <sup>c)</sup>  | Supported               | Supported      |
+| Non-Receipt Notification                                                                                                                                                                                                                                                                                                                                                                                                                                                        | <R-RecipientSpec><br><S-RecipientSpec>   | RECIPIENT ADDRESS  | –<br>Supported          | Supported<br>– |
+| Non-Delivery Report                                                                                                                                                                                                                                                                                                                                                                                                                                                             | <R-RecipientSpec><br><S-RecipientSpec>   | RECIPIENT ADDRESS  | –<br>Supported          | Supported<br>– |
+| Obsoleting IPM Indication                                                                                                                                                                                                                                                                                                                                                                                                                                                       | <RelatedSpec>                            | RELATED            | Supported               | Supported      |
+| Originator Indication                                                                                                                                                                                                                                                                                                                                                                                                                                                           | <R-OriginatorSpec><br><S-OriginatorSpec> | ADDRESS ORIGINATOR | –<br>Supported          | Supported<br>– |
+| Primary and Copy Recipients Indication                                                                                                                                                                                                                                                                                                                                                                                                                                          | <R-RecipientSpec><br><S-RecipientSpec>   | RECIPIENT ADDRESS  | –<br>Supported          | Supported<br>– |
+| Probe Indication                                                                                                                                                                                                                                                                                                                                                                                                                                                                | <Convert>                                | CONVERT            | Supported               | Not supported  |
+| Receipt Notification                                                                                                                                                                                                                                                                                                                                                                                                                                                            | <R-RecipientSpec><br><S-RecipientSpec>   | RECIPIENT ADDRESS  | –<br>Supported          | Supported<br>– |
+| Reply IP Message Indication                                                                                                                                                                                                                                                                                                                                                                                                                                                     | <ReplyId>                                | REPLYID            | Supported               | Supported      |
+| Reply Recipients Indication                                                                                                                                                                                                                                                                                                                                                                                                                                                     | <R-RecipientSpec><br><S-RecipientSpec>   | RECIPIENT ADDRESS  | –<br>Supported          | Supported<br>– |
+| Reply IPM Indication                                                                                                                                                                                                                                                                                                                                                                                                                                                            | <RelatedSpec>                            | RELATED            | Supported               | Supported      |
+| Reply Time Indication                                                                                                                                                                                                                                                                                                                                                                                                                                                           | <ReplyTime>                              | REPLYTIME          | Supported               | Supported      |
+| Sensitivity Indication                                                                                                                                                                                                                                                                                                                                                                                                                                                          | <Sensitivity>                            | SENSITIVITY        | Supported               | Supported      |
+| Subject Indication                                                                                                                                                                                                                                                                                                                                                                                                                                                              | <Subject>                                | SUBJECT            | Supported               | Supported      |
+| Submission Time Indication                                                                                                                                                                                                                                                                                                                                                                                                                                                      | <SubmitTime>                             | SUBMITIME          | Supported <sup>b)</sup> | Supported      |
+| <sup>a)</sup> The service elements IncompleteCopyIndication, LatestDeliveryIndication and MessageIdentification are additional. Therefore they are not addressed in the profile definition.<br><sup>b)</sup> The MessageSubmissionIdentification and the SubmissionTimeStamp is originated and maintained by the Message Transfer System (MTS). Both keywords are used in the <SendAckTDD> as output parameter.<br><sup>c)</sup> The assignment of a keyword is not applicable. |                                          |                    |                         |                |
+
+Table 113 summarizes the time stamps used within this Recommendation related to service elements of the message transfer system and the interpersonal messaging system.
+
+These service elements, their meaning and the corresponding keywords of the text based encoding are shown in Table 113. Another column of this table indicates, if the time stamps may be specified by the sending LA (Send TDD) and if they may be received by an LA (Receive TDD).
+
+TABLE 113/T.611
+
+#### **Summary of MHS Time-stamps**
+
+| Service Element              | Keyword      | Send/receive | Meaning                                                                                                                                                                                             |
+|------------------------------|--------------|--------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Expiry Date Indication       | EXPIRYTIME   | s/r          | This optional heading field of an IPM specifies the time when the authorizing user(s) consider the IPM to lose validity                                                                             |
+| Reply Time Indication        | REPLYTIME    | s/r          | This optional heading field of an IPM specifies the time by when the authorizing user(s) request that any replies to the subject IPM be originated                                                  |
+| Deferred Delivery Indication | SENDTIME     | s/–          | Specifies the time before which the message should not be delivered to the recipient(s); it may be generated by the originator of the message                                                       |
+| Latest Delivery Indication   | LASTTIME     | s/–          | Specifies the time after which the message should not be delivered to the recipient(s); it may be generated by the originator of the message                                                        |
+| Delivery Time Indication     | RCVTIME      | –/r          | Specifies the time at which the message was delivered to the recipient message transfer system user; it shall be generated by the message transfer system if the message was successfully delivered |
+| Submission Time Indication   | SUBMITTIME   | s/r          | Specifies the time at which the message transfer system accepts responsibility for the message; it shall be generated by the message transfer system                                                |
+| Receipt Time Indication      | RECEIPT-TIME | s/r          | Only used for receipt notification (RN); identifies the time when the originator of a notification has received the related IPM                                                                     |
+
+### 16.7 E-Mail Profiles
+
+This Recommendation provides access to E-Mail services as described in the ITU-T X.400-Series of Recommendation as well as to other E-Mail environments.
+
+Powerful stored-and-forward telecommunication services make high demands on an interface specification. The Send, SendAck and Receive TDDs are enhanced by a large number of basic E-Mail specific elements respecting the philosophie of this Recommendation. Most of these addressed service elements are optional.
+
+Enhanced features provided at the interface level for E-Mail access are:
+
+- transmission and reception of notifications;
+- reception of delivery reports;
+- transmission and reception of E-Mail message(s) included in an E-Mail message (e.g. IPM as body part).
+
+It is required that a CA implementation conforms to this Recommendation, even if not all possible features are supported. To improve the interoperability between LAs and CAs from different vendors, the concept of "profile" is introduced.
+
+The profiles:
+
+- X400-IPM;
+- BasicX400-IPM;
+- SimpleEMail.
+
+define functional service subsets offered at the interface level described in this Recommendation<sup>15)</sup>.
+
+Together with the ICE and the functional classes the profile concept identifies the E-Mail service elements supported by a CA.
+
+A CA may support one or more profiles. Moreover, implementers may describe and name their own profiles.
+
+#### **16.7.1 Service Profile X400-IPM**
+
+The X400-IPM profile comprises all X.400 service elements provided at the interface level of this Recommendation to support the conveyance of IPMs<sup>16)</sup> (see Table 114).
+
+#### **16.7.2 Service Profile BasicX400-IPM**
+
+The BasicX400-IPM profile specifies the basic functional subset of X.400 service elements provided at the interface level of this Recommendation to support the conveyance of IPMs (see Table 115).
+
+#### **16.7.3 Service Profile SimpleEMail**
+
+The SimpleEMail profile was introduced to enable access to E-Mail services which are not conforming to the open communication X.400-Series of Recommendation. It provides a minimal functional subset of E-Mail service elements provided at the interface level of this Recommendation (see Table 116).
+
+### **16.8 CA-Descriptor Settings**
+
+A CA supporting E-Mail services shall specify in the CA-Descriptor the body parts (document Transmission Formats), the profile(s) and the Content-Types supported (see also 9.5).
+
+For support of the EncodeIPM and DecodeIPM TDD, the EXTEND keyword of the CA-Descriptor has to be set accordingly. Table 117 depicts this.
+
+## **17 Service: File Transfer**
+
+This Recommendation allows sending or receiving information through File Transfer services. However, full control of File Transfer services through the interface is not intended.
+
+---
+
+<sup>15)</sup> Other profiles like EDIM and EDIN are for further study.
+
+<sup>16)</sup> The profile X400-IPM is specified according to the European Procurement Handbook for Open Systems (EPHOS), i.e. the profiles ENV 41201 and ENV 41202.
+
+TABLE 114/T.611
+
+### **Service Profile X400-IPM**
+
+| Service element                        | Syntax element                         | Support of CA |
+|----------------------------------------|----------------------------------------|---------------|
+| Alternate Recipient Allowed Indication | <Alternate>                            | Mandatory     |
+| Authorizing User's Indication          | <R-OriginatorSpec>, <S-OriginatorSpec> | Mandatory     |
+| Auto-forwarded Message Indication      | <Forwarded>                            | Mandatory     |
+| Blind Copy Recipients Indication       | <R-RecipientSpec>, <S-RecipientSpec>   | Mandatory     |
+| Content Type Indication                | <ContType>                             | Mandatory     |
+| Conversion Prohibition                 | <ImplicitConv>                         | Mandatory     |
+| Cross Referencing Indication           | <RelatedSpec>                          | Mandatory     |
+| Deferred Delivery Indication           | <SendTime>                             | Mandatory     |
+| Delivery Report                        | <R-RecipientSpec>, <S-RecipientSpec>   | Mandatory     |
+| Delivery Time Indication               | <ReceiveTime>                          | Mandatory     |
+| Disclosure of Other Recipients         | <DiscloRec>                            | Mandatory     |
+| Expiry Date Indication                 | <ExpiryTime>                           | Mandatory     |
+| Forwarded IP Message                   | <Type>                                 | Mandatory     |
+| Grade of Delivery Selection            | <Priority>                             | Mandatory     |
+| Importance Indication                  | <Importance>                           | Mandatory     |
+| Intended Recipient Indication          | <R-RecipientSpec>                      | Mandatory     |
+| IP Message Indication                  | <IpmlId>                               | Mandatory     |
+| Language Indication                    | <Language>                             | Mandatory     |
+| Message Submission Identification      | <MsgSubId>                             | Mandatory     |
+| Multi-Destination Delivery             | <R-RecipientSpec>, <S-RecipientSpec>   | Mandatory     |
+| Multi-Part Body                        | Implicit                               | Mandatory     |
+| Non-Receipt Notification               | <R-RecipientSpec>, <S-RecipientSpec>   | Mandatory     |
+| Non-Delivery Report                    | <R-RecipientSpec>, <S-RecipientSpec>   | Mandatory     |
+| Obsoleting IPM Indication              | <RelatedSpec>                          | Mandatory     |
+| Originator Indication                  | <R-OriginatorSpec>, <S-OriginatorSpec> | Mandatory     |
+| Primary and Copy Recipients Indication | <R-RecipientSpec>, <S-RecipientSpec>   | Mandatory     |
+| Probe Indication                       | <Convert>                              | Mandatory     |
+| Receipt Notification                   | <R-RecipientSpec>, <S-RecipientSpec>   | Mandatory     |
+| Reply IP Message Indication            | <ReplyId>                              | Mandatory     |
+| Reply Recipients Indication            | <R-RecipientSpec>, <S-RecipientSpec>   | Mandatory     |
+| Reply IPM Indication                   | <RelatedSpec>                          | Mandatory     |
+| Reply Time Indication                  | <ReplyTime>                            | Mandatory     |
+| Sensitivity Indication                 | <Sensitivity>                          | Mandatory     |
+| Subject Indication                     | <Subject>                              | Mandatory     |
+| Submission Time Indication             | <SubmitTime>                           | Mandatory     |
+
+TABLE 115/T.611
+
+### **Service Profile BasicX400-IPM**
+
+| Service element                        | Syntax element                         | Support of CA |
+|----------------------------------------|----------------------------------------|---------------|
+| Alternate Recipient Allowed Indication | <Alternate>                            | –             |
+| Authorizing User's Indication          | <R-OriginatorSpec>, <S-OriginatorSpec> | Mandatory     |
+| Auto-forwarded Message Indication      | <Forwarded>                            | –             |
+| Blind Copy Recipients Indication       | <R-RecipientSpec>, <S-RecipientSpec>   | Mandatory     |
+| Content Type Indication                | <ContType>                             | Mandatory     |
+| Conversion Prohibition                 | <ImplicitConv>                         | –             |
+| Cross Referencing Indication           | <RelatedSpec>                          | Mandatory     |
+| Deferred Delivery Indication           | <SendTime>                             | Mandatory     |
+| Delivery Report                        | <R-RecipientSpec>, <S-RecipientSpec>   | –             |
+| Delivery Time Indication               | <ReceiveTime>                          | –             |
+| Disclosure of Other Recipients         | <DiscloRec>                            | –             |
+| Expiry Date Indication                 | <ExpiryTime>                           | Mandatory     |
+| Forwarded IP Message                   | <Type>                                 | Mandatory     |
+| Grade of Delivery Selection            | <Priority>                             | Mandatory     |
+| Importance Indication                  | <Importance>                           | Mandatory     |
+| Intended Recipient Indication          | <R-RecipientSpec>                      | –             |
+| IP Message Indication                  | <IpmlId>                               | Mandatory     |
+| Language Indication                    | <Language>                             | Mandatory     |
+| Message Submission Identification      | <MsgSubId>                             | –             |
+| Multi-Destination Delivery             | <R-RecipientSpec>, <S-RecipientSpec>   | Mandatory     |
+| Multi-Part Body                        | implicit                               | Mandatory     |
+| Non-Receipt Notification               | <R-RecipientSpec>, <S-RecipientSpec>   | –             |
+| Non-Delivery Report                    | <R-RecipientSpec>, <S-RecipientSpec>   | –             |
+| Obsoleting IPM Indication              | <RelatedSpec>                          | Mandatory     |
+| Originator Indication                  | <R-OriginatorSpec>, <S-OriginatorSpec> | Mandatory     |
+| Primary and Copy Recipients Indication | <R-RecipientSpec>, <S-RecipientSpec>   | Mandatory     |
+| Probe Indication                       | <Convert>                              | –             |
+| Receipt Notification                   | <R-RecipientSpec>, <S-RecipientSpec>   | –             |
+| Reply IP Message Indication            | <ReplyId>                              | Mandatory     |
+| Reply Recipients Indication            | <R-RecipientSpec>, <S-RecipientSpec>   | Mandatory     |
+| Reply IPM Indication                   | <RelatedSpec>                          | Mandatory     |
+| Reply Time Indication                  | <ReplyTime>                            | Mandatory     |
+| Sensitivity Indication                 | <Sensitivity>                          | Mandatory     |
+| Subject Indication                     | <Subject>                              | Mandatory     |
+| Submission Time Indication             | <SubmitTime>                           | –             |
+
+TABLE 116/T.611
+
+### Service Profile SimpleEMail
+
+| Service element                        | Syntax element                         | Support of CA |
+|----------------------------------------|----------------------------------------|---------------|
+| Alternate Recipient Allowed Indication | <Alternate>                            | –             |
+| Authorizing User's Indication          | <R-OriginatorSpec>, <S-OriginatorSpec> | Mandatory     |
+| Auto-forwarded Message Indication      | <Forwarded>                            | –             |
+| Blind Copy Recipients Indication       | <R-RecipientSpec>, <S-RecipientSpec>   | Mandatory     |
+| Content Type Indication                | <ContType>                             | Mandatory     |
+| Conversion Prohibition                 | <ImplicitConv>                         | –             |
+| Cross Referencing Indication           | <RelatedSpec>                          | Mandatory     |
+| Deferred Delivery Indication           | <SendTime>                             | –             |
+| Delivery Report                        | <R-RecipientSpec>, <S-RecipientSpec>   | –             |
+| Delivery Time Indication               | <ReceiveTime>                          | –             |
+| Disclosure of Other Recipients         | <DiscloRec>                            | –             |
+| Expiry Date Indication                 | <ExpiryTime>                           | –             |
+| Forwarded IP Message                   | <Type>                                 | –             |
+| Grade of Delivery Selection            | <Priority>                             | Mandatory     |
+| Importance Indication                  | <Importance>                           | –             |
+| Intended Recipient Indication          | <R-RecipientSpec>                      | –             |
+| IP Message Indication                  | <IpmlId>                               | Mandatory     |
+| Language Indication                    | <Language>                             | –             |
+| Message Submission Identification      | <MsgSubId>                             | –             |
+| Multi-Destination Delivery             | <R-RecipientSpec>, <S-RecipientSpec>   | Mandatory     |
+| Multi-Part Body                        | Implicit                               | Mandatory     |
+| Non-Receipt Notification               | <R-RecipientSpec>, <S-RecipientSpec>   | –             |
+| Non-Delivery Report                    | <R-RecipientSpec>, <S-RecipientSpec>   | –             |
+| Obsoleting IPM Indication              | <RelatedSpec>                          | –             |
+| Originator Indication                  | <R-OriginatorSpec>, <S-OriginatorSpec> | Mandatory     |
+| Primary and Copy Recipients Indication | <R-RecipientSpec>, <S-RecipientSpec>   | Mandatory     |
+| Probe Indication                       | <Convert>                              | –             |
+| Receipt Notification                   | <R-RecipientSpec>, <S-RecipientSpec>   | –             |
+| Reply IP Message Indication            | <ReplyId>                              | Mandatory     |
+| Reply Recipients Indication            | <R-RecipientSpec>, <S-RecipientSpec>   | Mandatory     |
+| Reply IPM Indication                   | <RelatedSpec>                          | Mandatory     |
+| Reply Time Indication                  | <ReplyTime>                            | Mandatory     |
+| Sensitivity Indication                 | <Sensitivity>                          | Mandatory     |
+| Subject Indication                     | <Subject>                              | Mandatory     |
+| Submission Time Indication             | <SubmitTime>                           | –             |
+
+TABLE 117/T.611
+
+#### **Additional CA-Descriptor settings for E-Mail services**
+
+| Keyword                                                                                                                                                                                                                                                                                                                                   | Parameter                 | CA declares that                                                                                                                      |
+|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------|---------------------------------------------------------------------------------------------------------------------------------------|
+| EMAIL                                                                                                                                                                                                                                                                                                                                     | "STD"                     | text body parts are supported; "STD" maps to the appropriate basic alphabet of the selected E-Mail service                            |
+| EMAIL                                                                                                                                                                                                                                                                                                                                     | "TELETEX"                 | teletex body parts are supported                                                                                                      |
+| EMAIL                                                                                                                                                                                                                                                                                                                                     | "VIDEOTEX"                | videotex body parts are supported                                                                                                     |
+| EMAIL                                                                                                                                                                                                                                                                                                                                     | "G3FAX"                   | telefax group 3 body parts are supported                                                                                              |
+| EMAIL                                                                                                                                                                                                                                                                                                                                     | "G4CLASS1"                | telefax group 4 body parts are supported                                                                                              |
+| EMAIL                                                                                                                                                                                                                                                                                                                                     | "MIXEDMODE"               | mixed mode body parts are supported                                                                                                   |
+| EMAIL                                                                                                                                                                                                                                                                                                                                     | "MESSAGE"                 | IPM body parts are supported                                                                                                          |
+| EMAIL                                                                                                                                                                                                                                                                                                                                     | "BILATERAL" <sup>a)</sup> | bilateral defined body parts are supported                                                                                            |
+| EMAIL                                                                                                                                                                                                                                                                                                                                     | "NATIONAL"                | national defined body parts are supported                                                                                             |
+| EMAIL                                                                                                                                                                                                                                                                                                                                     | "ODA"                     | ODA body parts are supported                                                                                                          |
+| CONT-TYPE                                                                                                                                                                                                                                                                                                                                 | "mhsIPMxx"                | MHS IPM content protocol is supported (xx stands for the year of release of the related Recommendation, e.g. 84 for 1984)             |
+| CONT-TYPE                                                                                                                                                                                                                                                                                                                                 | "mhsIPNxx"                | MHS IPN content protocol is supported (the CA understands IPN documents as described in <b>Error! Not a valid result for table.</b> ) |
+| CONT-TYPE                                                                                                                                                                                                                                                                                                                                 | "mhsDR"                   | MHS DR content protocol is supported (the CA understands DR documents as described in 16.5)                                           |
+| PROFILE                                                                                                                                                                                                                                                                                                                                   | "X400-IPM"                | the X400 profile is supported                                                                                                         |
+| PROFILE                                                                                                                                                                                                                                                                                                                                   | "BasicX400-IPM"           | the BasicX400 profile is supported                                                                                                    |
+| PROFILE                                                                                                                                                                                                                                                                                                                                   | "SimpleEMail"             | the SimpleEMail profile is supported                                                                                                  |
+| EXTEND                                                                                                                                                                                                                                                                                                                                    | "EncodeIPM"               | the EncodeIPM functionality is supported                                                                                              |
+| EXTEND                                                                                                                                                                                                                                                                                                                                    | "DecodeIPM"               | the DecodeIPM functionality is supported                                                                                              |
+| <sup>a)</sup> "Bilateral" is used for other body part types not mentioned (in this list).<br><br>NOTE – A CA may also support other or private E-Mail systems. In this case the type of E-Mail system should be reflected in the CONT-TYPE and PROFILE parameters (e.g "CONT-TYPE : cmcIPM" for support of CMC Interfaces, see 16.2.2.9). |                           |                                                                                                                                       |
+
+### **17.1 Service Specific Syntax Elements**
+
+<ServiceDependentKeywordsSend> :=  
+    (<Recipient> | <RecipientSpec>)  
+    (((<Document> <Convert> [<Type>]) | <DocumentSpec>)  
+    <Compress> <Environ> [<Password>] [<Name>]
+
+<ServiceDependentKeywordsSendAck> :=  
+    <Recipient>  
+    (((<Document> <Convert> [<Type>]) | <DocumentSpec>)  
+    <Compress> <Environ> [<Password>] [<Name>]
+
+<ServiceDependentKeywordsReceive> :=  
+ [<Originator>]  
+ ((<Document> <Convert> <Type>) | <DocumentSpec>)  
+ <Compress> <Environ> [<Password>] [<Name>]
+
+See Table 118.
+
+TABLE 118/T.611  
+**Additional syntax elements for FT services**
+
+| Syntax element               | Purpose                                                                     |
+|------------------------------|-----------------------------------------------------------------------------|
+| <Compress>                   | Specifies the data compression format of the transferred file(s)            |
+| <Convert>                    | Specifies the Transfer Format to be used                                    |
+| <Document>, <DocumentSpec>   | Specifies the document or the documents to be sent or being received        |
+| <Environ>                    | Specifies the operating system the file was created under by the originator |
+| <Name>                       | Name the file has under the originating operating system                    |
+| <Originator>                 | Specifies the communications address of the originator                      |
+| <Password>                   | Password needed to access remote station                                    |
+| <Recipient>, <RecipientSpec> | Specifies the communications address(es) of the recipient(s)                |
+| <Type>                       | Specifies the Transmission Format used                                      |
+
+### 17.2 Text Based Encoding
+
+#### 17.2.1 Mapping of Keywords
+
+See Table 119.
+
+TABLE 119/T.611  
+**Text Based Encoding of additional syntax elements for FT services**  
+ (A ↵ stands for new line)
+
+| Syntax element  | Keyword/Parameter Pair                  |
+|-----------------|-----------------------------------------|
+| <Compress>      | "COMPRESS" ":" <Compress-parameter> ↵   |
+| <Convert>       | "CONVERT" ":" <Convert-id-parameter> ↵  |
+| <Document>      | "FILENAME" ":" <File-parameter> ↵       |
+| <DocumentSpec>  | "FILENAME" ":" "@" <File-of-filespec> ↵ |
+| <Environ>       | "ENVIRON" ":" <Environ-parameter> ↵     |
+| <Name>          | "NAME" ":" <Name-parameter> ↵           |
+| <Originator>    | "ADDRESS" ":" <Address-parameter> ↵     |
+| <Password>      | "PASSWORD" ":" <Password-parameter> ↵   |
+| <Recipient>     | "ADDRESS" ":" <Address-parameter> ↵     |
+| <RecipientSpec> | "ADDRESS" ":" "@" <File-of-addrspec> ↵  |
+| <Type>          | "TYPE" ":" <Type-id-parameter> ↵        |
+
+#### 17.2.2 Encoding of Parameters
+
+See also 6.4.4 for the encoding of non service dependent parameters used.
+
+##### 17.2.2.1 Service-id-parameter
+
+The Service-id parameter is encoded as STRING set to the constant value "FT".
+
+*Syntax:*
+
+<Service-id-parameter> := "FT"
+
+##### 17.2.2.2 Type-id-parameter
+
+The Type-id-parameter is encoded as STRING set to the constant value "STD".
+
+*Syntax:*
+
+<Type-id-parameter> := "STD"
+
+##### 17.2.2.3 Convert-id-parameter
+
+The Convert-id-parameter is encoded as STRING set to the constant value "VOID".
+
+*Syntax:*
+
+<Convert-id-parameter> := "VOID"
+
+##### 17.2.2.4 File-of-addrspec and Address-parameter
+
+The File-of-addrspec parameter is encoded as PATH which points to a file containing Addrspec-parameters, which contain the Address-parameter.
+
+The Address-parameter is encoded as STRING. The STRING shall contain the telephone number. If the phone number starts with a "!" then it may contain special characters that are treated as operators (or modifiers) rather than dial digits. The characters allowed are for further study.
+
+Alternatively an alias name may be given instead of the phone number, provided the alias is introduced with an "&" character. It is assumed that the CA knows how to decode the alias specified.
+
+*Syntax:*
+
+<File-of-addrspec> :=  
+PATH  
+-- The path points to a file containing one ore more  
+-- <Addrspec-parameter>s
+
+<Addrspec-parameter> := <Address-parameter>
+
+<Address-parameter> :=  
+<Phone-number> | ("!" <Dial-command>) | ("&" <Alias>)  
+-- contains telephone number, dialing sequence or alias
+
+<Phone-number> := NUMERIC-STRING
+
+<Dial-command> :=  
+STRING  
+-- for further study
+
+<Alias> := STRING
+
+##### 17.2.2.5 File-of-filespec and File-parameter
+
+The File-of-filespec parameter is encoded as PATH which points to a file containing Filespec-parameters, which contain the File-parameter. The File-parameter itself is also encoded as PATH, which points to the file transferred.
+
+*Syntax:*
+
+```
+<File-of-filespec> :=          PATH
+                             -- The path points to a file containing one ore more
+                             -- <Filespec-parameter>s
+
+<Filespec-parameter> :=      <File-parameter> "," <File-conv>
+                             ["," [<File-type>] ["," [<File-compress> ] ["," <File-name>] ] ]
+
+<File-parameter> :=          PATH
+                             -- Path to the file transferred
+
+<File-conv> :=                <Convert-id-parameter>
+                             -- Specifies the Transfer Format of the file
+
+<File-type> :=                <Type-id-parameter>
+                             -- Specifies the Transmission Format of the file
+
+<File-compress> :=           <Compress-parameter>
+                             -- Specifies the compression
+
+<File-name> :=                <Name-parameter>
+                             -- Specifies the name of the file
+```
+
+##### 17.2.2.6 Compress-parameter
+
+The Compress-parameter is encoded as STRING set to one of the following values:
+
+|           |                          |
+|-----------|--------------------------|
+| "VOID"    | No compression (default) |
+| any other | Compression identifier   |
+
+*Syntax:*
+
+```
+<Compress-parameter> :=      "VOID" | <Compress-identifier>
+<Compress-identifier> :=     STRING
+                             -- e.g. "ZIP", "AZJ", "ARJ", "LZH" or "V42"
+```
+
+##### 17.2.2.7 Environ-parameter
+
+The Environ-parameter is coded as STRING set to one of the following values:
+
+|           |                            |
+|-----------|----------------------------|
+| "MSDOS"   | MS-DOS                     |
+| "WINDOWS" | Windows                    |
+| "UNIX"    | Unix                       |
+| "OS2"     | OS/2                       |
+| "MacOS"   | Mac                        |
+| any other | Reserved for further study |
+
+*Syntax:*
+
+```
+<Environ-parameter> :=      "MSDOS" | "WINDOWS" | "UNIX" | "OS2" | "MacOS"
+```
+
+##### 17.2.2.8 Password-parameter
+
+The Password-parameter is encoded as STRING.
+
+*Syntax:*
+
+```
+<Password-parameter> :=     STRING
+```
+
+##### 17.2.2.9 Name-parameter
+
+The Name-parameter is encoded as STRING between 1 and 16 characters long.
+
+*Syntax:*
+
+```
+<Name-parameter> :=         STRING (SIZE(1..16))
+```
+
+### 17.3 Additional Functionality
+
+#### 17.3.1 Function: Send and SendAck
+
+See Tables 120 and 121.
+
+TABLE 120/T.611
+
+##### Additional functionality of the <SendTDD> for File Transfer
+
+| Syntax Element                 | C | T | I/O | Text Based Encoding |                        |         | Comment                                                                                                          |
+|--------------------------------|---|---|-----|---------------------|------------------------|---------|------------------------------------------------------------------------------------------------------------------|
+|                                |   |   |     | Keyword             | Parameter              | Default |                                                                                                                  |
+| <Environ>                      | B | m | I   | ENVIRON             | <Environ-parameter>    | –       | Operating system of sender                                                                                       |
+| <Password>                     | B | o | I   | PASSWORD            | <Password-parameter>   | –       | Password for access of remote filesystem                                                                         |
+| Send to one addressee          |   |   |     |                     |                        |         |                                                                                                                  |
+| <Recipient>                    | B | m | I   | ADDRESS             | <Address-parameter>    | –       | Specifies one recipient's call number                                                                            |
+| Send to one or many addressees |   |   |     |                     |                        |         |                                                                                                                  |
+| <RecipientSpec>                | + | m | I   | ADDRESS             | "@" <File-of-addrspec> | –       | Specifies a list of recipients                                                                                   |
+| Send only one file             |   |   |     |                     |                        |         |                                                                                                                  |
+| <Convert>                      | B | m | I   | CONVERT             | <Convert-id-parameter> | –       | States the Transfer Format of the outgoing file                                                                  |
+| <Document>                     | B | m | I   | FILENAME            | <File-parameter>       | –       | The single outgoing file to be transmitted, delivered under the Transfer Format specified by the Convert keyword |
+| <Type>                         | B | o | I   | TYPE                | <Type-id-parameter>    | "STD"   | Specifies the document type to be sent                                                                           |
+| <Compress>                     | B | o | I   | COMPRESS            | <Compress-parameter>   | "VOID"  | Compression                                                                                                      |
+| <Name>                         | B | o | I   | NAME                | <Name-parameter>       | –       | Name of file under original environment                                                                          |
+| Send one or many files         |   |   |     |                     |                        |         |                                                                                                                  |
+| <DocumentSpec>                 | + | m | I   | FILENAME            | "@" <File-of-filespec> | –       | Specifies a list of files; uses a special syntax                                                                 |
+
+TABLE 121/T.611
+
+##### **Additional functionality of the <SendAckTDD> for File Transfer**
+
+| Syntax Element         | C | T | I/O | Text Based Encoding |                        |         | Comment                                                                                                          |
+|------------------------|---|---|-----|---------------------|------------------------|---------|------------------------------------------------------------------------------------------------------------------|
+|                        |   |   |     | Keyword             | Parameter              | Default |                                                                                                                  |
+| <Recipient>            | B | m | I/O | ADDRESS             | <Address-parameter>    | –       | Specifies one recipient's call number                                                                            |
+| <Environ>              | B | m | I   | ENVIRON             | <Environ-parameter>    | –       | Operating system of sender                                                                                       |
+| <Password>             | B | o | I   | PASSWORD            | <Password-parameter>   | –       | Password for access of remote filesystem                                                                         |
+| Send only one file     |   |   |     |                     |                        |         |                                                                                                                  |
+| <Convert>              | B | m | I   | CONVERT             | <Convert-id-parameter> | –       | States the Transfer Format of the outgoing file                                                                  |
+| <Document>             | B | m | I   | FILENAME            | <File-parameter>       | –       | The single outgoing file to be transmitted, delivered under the Transfer Format specified by the Convert keyword |
+| <Type>                 | B | o | I   | TYPE                | <Type-id-parameter>    | "STD"   | Specifies the document type to be sent                                                                           |
+| <Compress>             | B | o | I   | COMPRESS            | <Compress-parameter>   | "VOID"  | Compression                                                                                                      |
+| <Name>                 | B | o | I   | NAME                | <Name-parameter>       | –       | Name of file under original environment                                                                          |
+| Send one or many files |   |   |     |                     |                        |         |                                                                                                                  |
+| <DocumentSpec>         | + | m | I   | FILENAME            | "@" <File-of-filespec> | –       | Specifies a list of files; uses a special syntax                                                                 |
+
+#### 17.3.2 Function: Receive
+
+See Table 122.
+
+TABLE 122/T.611
+
+##### Additional functionality of the <ReceiveTDD> for File Transfer
+
+| Syntax Element         | C | T | I/O | Text Based Encoding |                        |         | Comment                                                                                                                                                                                |
+|------------------------|---|---|-----|---------------------|------------------------|---------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+|                        |   |   |     | Keyword             | Parameter              | Default |                                                                                                                                                                                        |
+| <Environ>              | B | m | O   | ENVIRON             | <Environ-parameter>    | –       | Operating system of sender                                                                                                                                                             |
+| <Password>             | B | o | I   | PASSWORD            | <Password-parameter>   | –       | Password for access of remote filesystem                                                                                                                                               |
+| <Originator>           | B | o | O   | ADDRESS             | <Address-parameter>    | –       | Specifies originator's phone number                                                                                                                                                    |
+| Only one file received |   |   |     |                     |                        |         |                                                                                                                                                                                        |
+| <Convert>              | B | m | O   | CONVERT             | <Convert-id-parameter> | –       | States the Transfer Format of the received file                                                                                                                                        |
+| <Document>             | B | m | I/O | FILENAME            | <File-parameter>       | –       | The filename may be pre-set by the LA on request. If only one file is received, the name shall be retained by the CA. If many files are received the name may be overwritten by the CA |
+| <Type>                 | B | o | O   | TYPE                | <Type-id-parameter>    | –       | Specifies the document type received                                                                                                                                                   |
+| <Compress>             | B | o | O   | COMPRESS            | <Compress-parameter>   | "VOID"  | Compression                                                                                                                                                                            |
+| <Name>                 | B | o | O   | NAME                | <Name-parameter>       | –       | Name of file under original environ                                                                                                                                                    |
+| Many files received    |   |   |     |                     |                        |         |                                                                                                                                                                                        |
+| <DocumentSpec>         | + | m | O   | FILENAME            | "@" <File-of-filespec> | –       | Specifies a list of files; uses a special syntax                                                                                                                                       |
+
+### 17.4 CA-Descriptor Settings
+
+A CA supporting the File Transfer service shall specify the Type-id-parameter "STD" (see Table 123).
+
+TABLE 123/T.611
+
+#### Additional CA-Descriptor settings for File Transfer
+
+| Keyword | Parameter | CA declares that                             |
+|---------|-----------|----------------------------------------------|
+| FT      | "STD"     | the basic file transfer service is supported |
+
+# PART III – BINARY ENCODING SCHEME
+
+## 18 Generic C description
+
+This clause describes the binary encoding scheme for the TDDs using a “generic” C-language description (see also A.2). The binary coding scheme requires the Code-ID set to “C” (see 6.3). The purpose of this description is to provide binary compatibility of TDDs between different vendors’ applications using the binary encoding scheme.
+
+The descriptions provided have to be adapted to the supporting platform to perform properly (see also Part IV of this Recommendation).
+
+The following generic C data types are used to describe the TDDs. These data types shall be mapped onto their specific, platform-dependent C data type counterparts (see Table 124).
+
+TABLE 124/T.611
+
+**Generic C data types**
+
+| Generic C data type | Comment                                     |
+|---------------------|---------------------------------------------|
+| INT16               | A signed integer value, coded on 16 bits    |
+| UINT32              | An unsigned integer value, coded on 32 bits |
+| CHAR                | A character, coded on 8 bits                |
+| BYTE                | An octet, coded on 8 bits                   |
+
+### 18.1 Binary encoding of TDDs
+
+The Request TDDs and Responses are represented by C structures. The components of those structures correspond to the syntax elements used in text-based encodings, as defined in clause 6 and the appropriate clauses of Part **Error! Reference source not found.** of this Recommendation.
+
+The binary layout, described with C-Language structures, has been chosen so that elements of different data types are aligned to a 4 byte boundary.
+
+Each TDD consists of, in order:
+
+- a 4 octet wide binary header;
+- a 16 octet wide TDD descriptor, which contains the offsets to four specific sections in the TDD layout; the offsets are computed from the base of the binary header.
+
+The rest of the binary layout is made up by the four specific sections, which may appear in any order:
+
+- *TDD section 1* – Contains the common input parameters, i.e. the ones described in clause 6.
+- *TDD section 2* – Contains the service dependent input parameters, i.e. the ones described in the appropriate clause of Part II of this Recommendation.
+- *TDD section 3* – Contains the common output parameters, i.e. the ones described in clause 6.
+- *TDD section 4* – Contains the service dependent out parameters, i.e. the ones described in the appropriate clause of Part II of this Recommendation.
+
+Because of this structure it is possible for applications to add or enhance parameters of a TDD with private parameters.
+
+Figure 16 below depicts this structure.
+
+![Diagram of the Binary Structure of TDD. It shows a hierarchical structure with a Header, a Descriptor, and four Sections. The Header contains Code-ID, Byte order, Version, and TDD Function. The Descriptor contains offsets for Section 1, 2, 3, and 4. Section 1 contains Common Input Parameter and Private Parameter. Section 2 contains Service specific Input-Parameter and Private Parameter. Section 3 contains Common Output Parameter and Private Parameter. Section 4 contains Service specific Output Parameter and Private Parameter. Arrows indicate that the offsets in the Descriptor point to the start of each corresponding section.](46b6ae100e671c34c024598495e56c99_img.jpg)
+
+The diagram illustrates the binary structure of TDD. It is organized into five main parts, each enclosed in a dashed box:
+
+- Header:** Contains Code-ID, Byte order, Version, and TDD Function.
+- Descriptor:** Contains Offset Section 1, Offset Section 2, Offset Section 3, and Offset Section 4. Arrows from these offsets point to the corresponding sections.
+- Section 1:** Contains Common Input Parameter and Private Parameter.
+- Section 2:** Contains Service specific Input-Parameter and Private Parameter.
+- Section 3:** Contains Common Output Parameter and Private Parameter.
+- Section 4:** Contains Service specific Output Parameter and Private Parameter.
+
+T0823520-95/d20
+
+Diagram of the Binary Structure of TDD. It shows a hierarchical structure with a Header, a Descriptor, and four Sections. The Header contains Code-ID, Byte order, Version, and TDD Function. The Descriptor contains offsets for Section 1, 2, 3, and 4. Section 1 contains Common Input Parameter and Private Parameter. Section 2 contains Service specific Input-Parameter and Private Parameter. Section 3 contains Common Output Parameter and Private Parameter. Section 4 contains Service specific Output Parameter and Private Parameter. Arrows indicate that the offsets in the Descriptor point to the start of each corresponding section.
+
+FIGURE 16/T.611  
+Binary Structure of TDD
+
+#### 18.1.1 TDD Header
+
+```
+/**
+ *    <TDD> syntax element
+ ***/
+```
+
+```
+struct tdd {
+    struct tdd_header    hdr;        /* <TDD Header> syntax element, see below */
+    struct tdd_descriptor ofs;        /* Descriptor containing offsets, see below */
+};                                  /* Function dependent TDD structures ... */
+```
+
+```
+/**
+ *    <TDD Header> syntax element
+ ***/
+```
+
+```
+struct tdd_header {
+    BYTE_code_id;        /* Code-ID, constant set to 0x43 ('C') */
+    BYTE_byte_order;     /* Optional constant value indicating byte order */
+    BYTE_itu_version;    /* Constant indicating version of this Recommendation */
+    BYTE_function;       /* Function code */
+};
+```
+
+```
+
+/**
+ *      Offset descriptor
+ ***/
+
+```
+
+```
+
+struct tdd_descriptor {
+    UINT32 cinp;           /* offset to section 1 (common input parameter) */
+    UINT32 sinp;           /* offset to section 2 (service dependent input parameter) */
+    UINT32 coup;           /* offset to section 3 (common output parameter) */
+    UINT32 soup;           /* offset to section 4 (service dependent output parameter) */
+};
+
+```
+
+#### 18.1.2 Service independent TDD structures
+
+```
+
+/**
+ *      <SendTDD> structure
+ ***/
+
+```
+
+```
+
+struct send_tdd_inp {
+    La_id_type           la_id;           /* common input parms */
+    Req_id_type           req_id;         /* <Lald> */
+    Service_type           service;       /* <ReqID> */
+    Date_time_type        sendtime;       /* <Service> */
+    Date_time_type        lasttime;       /* <SendTime> */
+    Comment_type           comment;       /* <LastTime> */
+    Userkey_type           userkey;       /* <Comment> */
+};
+
+```
+
+```
+
+/**
+ *      <SendackTDD> structure
+ ***/
+
+```
+
+```
+
+struct sendack_tdd_inp {
+    La_id_type           la_id;           /* common input parms */
+    Req_id_type           req_id;         /* <Lald> */
+    Service_type           service;       /* <ReqID> */
+    Date_time_type        sendtime;       /* <Service> */
+    Date_time_type        lasttime;       /* <SendTime> */
+    Comment_type           comment;       /* <LastTime> */
+    Userkey_type           userkey;       /* <Comment> */
+};
+
+```
+
+```
+
+struct sendack_tdd_out {
+    Comid_type           comid;           /* common output parms */
+    Status_type           status;         /* <ComId> */
+    Error_type            error;          /* <Status> */
+    Error_type            minor;          /* <Error> */
+    Error_type            warning;        /* <Minor> */
+};
+
+```
+
+```
+
+/**
+ *      <ReceiveTDD> structure
+ ***/
+
+```
+
+```
+
+struct receive_tdd_inp {
+    La_id_type           la_id;           /* common input parms */
+    Req_id_type           req_id;         /* <Lald> */
+    Service_type           service;       /* <ReqID> */
+    Boolean_type           deletedoc;     /* <Service> */
+    Comid_type            comid;          /* <Delete > */
+};
+
+```
+
+```
+
+struct receive_tdd_out {
+    Comid_type      comid;      /* common output parms */
+    Status_type     status;     /* <ComId> */
+    Error_type      error;      /* <Status> */
+    Error_type      minor;      /* <Error> */
+    Error_type      warning;    /* <Minor> */
+    Service_type     service;    /* <Warning> */
+    Date_time_type  rcvtime;    /* <Service> */
+    };                         /* <ReceiveTime> */
+
+```
+
+```
+
+/****
+*      <CopyTDD> structure
+****/
+
+```
+
+```
+
+struct copy_tdd_inp {
+    La_id_type      la_id;      /* common input parms */
+    Req_id_type     req_id;     /* <Lald> */
+    Comid_type      comid;     /* <ReqID> */
+    Req_id_type     reqref;    /* <ComId> */
+    State_type      state;     /* <ReqRef> */
+    Path_type       target;    /* <State> */
+    Layout_id_type  layout;    /* <Target> */
+    };                         /* <Layout> */
+
+```
+
+```
+
+struct copy_tdd_out {
+    Error_type      error;      /* common output parms */
+    Error_type      minor;     /* <Error> */
+    Error_type      warning;    /* <Minor> */
+    };                         /* <Warning> */
+
+```
+
+```
+
+/****
+*      <DeleteTDD> structure
+****/
+
+```
+
+```
+
+struct delete_tdd_inp {
+    La_id_type      la_id;      /* common input parms */
+    Req_id_type     req_id;     /* <Lald> */
+    Comid_type      comid;     /* <ReqID> */
+    Req_id_type     reqref;    /* <ComId> */
+    };                         /* <ReqRef> */
+
+```
+
+```
+
+struct delete_tdd_out {
+    Error_type      error;      /* common output parms */
+    Error_type      minor;     /* <Error> */
+    Error_type      warning;    /* <Minor> */
+    };                         /* <Warning> */
+
+```
+
+```
+
+/****
+*      <CancelTDD> structure
+****/
+
+```
+
+```
+
+struct cancel_tdd_inp {
+    La_id_type      la_id;      /* common input parms */
+    Req_id_type     req_id;     /* <Lald> */
+    Comid_type      comid;     /* <ReqID> */
+    Req_id_type     reqref;    /* <ComId> */
+    };                         /* <ReqRef> */
+
+```
+
+```
+
+struct cancel_tdd_out {
+    Error_type      error;      /* common output parms */
+    Error_type      minor;      /* <Error> */
+    Error_type      warning;    /* <Minor> */
+    Error_type      /* <Warning> */
+};
+
+```
+
+```
+
+/****
+*      <PurgeTDD> structure
+****/
+
+```
+
+```
+
+struct purge_tdd_in {
+    La_id_type      la_id;      /* common input parms */
+    Req_id_type     req_id;     /* <Lald> */
+    Comid_type      comid;     /* <ReqID> */
+    Req_id_type     reqref;    /* <ComId> */
+    State_type      state;     /* <ReqRef> */
+    /* <State> */
+};
+
+```
+
+```
+
+struct purge_tdd_out {
+    Error_type      error;      /* common output parms */
+    Error_type      minor;      /* <Error> */
+    Error_type      warning;    /* <Minor> */
+    Error_type      /* <Warning> */
+};
+
+```
+
+```
+
+/****
+*      <RescheduleTDD> structure
+****/
+
+```
+
+```
+
+struct reschedule_tdd_in {
+    La_id_type      la_id;      /* common input parms */
+    Req_id_type     req_id;     /* <Lald> */
+    Comid_type      comid;     /* <ReqID> */
+    Req_id_type     reqref;    /* <ComId> */
+    Address_type     address;   /* <ReqRef> */
+    Date_time_type  sendtime;   /* <Address> */
+    Date_time_type  lasttime;   /* <SendTime> */
+    /* <LastTime> */
+};
+
+```
+
+```
+
+struct reschedule_tdd_out {
+    Error_type      error;      /* common output parms */
+    Error_type      minor;      /* <Error> */
+    Error_type      warning;    /* <Minor> */
+    Error_type      /* <Warning> */
+};
+
+```
+
+```
+
+/****
+*      <DispatchTDD> structure
+****/
+
+```
+
+```
+
+struct dispatch_tdd_in {
+    La_id_type      la_id;      /* common input parms */
+    Req_id_type     req_id;     /* <Lald> */
+    Comid_type      comid;     /* <ReqID> */
+    La_id_type      newla;     /* <ComId> */
+    /* <NewLa> */
+};
+
+```
+
+```
+
+struct dispatch_tdd_out {
+    Error_type      error;      /* common output parms */
+    Error_type      minor;      /* <Error> */
+    Error_type      warning;    /* <Minor> */
+    Error_type      /* <Warning> */
+};
+
+```
+
+```
+
+/**
+ *      <PreviewTDD> structure
+ */
+
+struct preview_tdd_inp {
+    La_id_type      la_id;      /* common input parms */
+    Req_id_type     req_id;     /* <Lald> */
+    Comid_type      comid;     /* <ReqID> */
+    Path_type       target;    /* <ComId> */
+    Convert_id_type convert;    /* <Target> */
+};
+
+struct preview_tdd_out {
+    Error_type      error;     /* common output parms */
+    Error_type      minor;    /* <Error> */
+    Error_type      warning;  /* <Minor> */
+};
+
+/**
+ *      <PrintTDD> structure
+ */
+
+struct print_tdd_inp {
+    La_id_type      la_id;     /* common input parms */
+    Req_id_type     req_id;    /* <Lald> */
+    Path_type       filename;  /* <ReqID> */
+    Convert_id_type informat;  /* <FileName> */
+    Printer_id_type printer;   /* <InFormat> */
+};
+
+struct print_tdd_out {
+    Error_type      error;     /* common output parms */
+    Error_type      minor;    /* <Error> */
+    Error_type      warning;  /* <Minor> */
+};
+
+/**
+ *      <ConvertTDD> structure
+ */
+
+struct convert_tdd_inp {
+    La_id_type      la_id;     /* common input parms */
+    Req_id_type     req_id;    /* <Lald> */
+    Path_type       filename;  /* <ReqID> */
+    Path_type       target;    /* <ComId> */
+    Convert_id_type informat;  /* <Target> */
+    Convert_id_type outformat; /* <InFormat> */
+};
+
+struct convert_tdd_out {
+    Error_type      error;     /* common output parms */
+    Error_type      minor;    /* <Error> */
+    Error_type      warning;  /* <Minor> */
+};
+
+/**
+ *      <CheckTDD> structure
+ */
+
+```
+
+```
+
+struct check_tdd_inp {
+    La_id_type      la_id;
+    Req_id_type     req_id;
+    Path_type       filename;
+    Convert_id_type check;
+};
+
+/* common input parms */
+/* <Lald> */
+/* <ReqID> */
+/* <FileName> */
+/* <Check> */
+
+struct check_tdd_out {
+    Error_type      error;
+    Error_type      minor;
+    Error_type      warning;
+};
+
+/* common output parms */
+/* <Error> */
+/* <Minor> */
+/* <Warning> */
+
+/**
+ * <ExtendTDD> structure
+ ***/
+
+struct extend_tdd_inp {
+    Subfunc_type    subfunc;
+    La_id_type      la_id;
+    Req_id_type     req_id;
+};
+
+/* common input parms */
+/* <SubFunction> */
+/* <Lald> */
+/* <ReqID> */
+
+struct extend_tdd_out {
+    Error_type      error;
+    Error_type      minor;
+    Error_type      warning;
+};
+
+/* common output parms */
+/* <Error> */
+/* <Minor> */
+/* <Warning> */
+
+/**
+ * <NationalTDD> structure
+ ***/
+
+struct national_tdd_inp {
+    subfunc;
+    La_id_type      la_id;
+    Req_id_type     req_id;
+    /*      ...
+};
+
+/* common input parms */Subfunc_type
+/* <NationalFunction>, for further study */
+/* <Lald> */
+/* <ReqID> */
+<--- others are added here, for further study */
+
+struct national_c_out {
+    Error_type      error;
+    Error_type      minor;
+    Error_type      warning;
+    /*      ...
+};
+
+/* common output parms */
+/* <Error> */
+/* <Minor> */
+/* <Warning> */
+<--- others are added here, for further study */
+
+/**
+ * <PrivateTDD> structure
+ ***/
+
+struct private_tdd_inp {
+    Subfunc_type    subfunc;
+    La_id_type      la_id;
+    Req_id_type     req_id;
+    /*      ...
+};
+
+/* common input parms */
+/* <PrivateFunction>, for further study */
+/* <Lald> */
+/* <ReqID> */
+<--- others are added here, for further study */
+
+```
+
+```
+
+struct private_tdd_out {
+    Error_type      error;          /* common output parms */
+    Error_type      minor;         /* <Error> */
+    Error_type      warning;       /* <Minor> */
+    /*      ...                    /* <Warning> */
+};                                <--- others are added here, for further study */
+
+```
+
+#### 18.1.3 Service Independent Constants and Type Definitions
+
+```
+
+/**
+ *      Constants used for fields of struct tdd_header
+ */
+
+/*      code_id field */
+#define CODE_ID      0x43          /* Code-ID, set to 'C' */
+
+/*      byte_order field */
+#define L_BYTEORDER      0x4C      /* Little Endian (Intel, low-high) byte order */
+#define B_BYTEORDER      0x42      /* Big endian byte order */
+
+/*      itu_version field */
+#define ITU_VERSION      94        /* Current version (1994) */
+
+/*      function field */
+#define SENDACK_TDD      0x10       /* <SendAckFunction> */
+#define SEND_TDD         0x11       /* <SendFunction> */
+#define RECEIVE_TDD      0x20       /* <ReceiveFunction> */
+#define COPY_TDD         0x30       /* <CopyFunction> */
+#define DELETE_TDD       0x31       /* <DeleteFunction> */
+#define CANCEL_TDD       0x32       /* <CancelFunction> */
+#define PURGE_TDD        0x33       /* <PurgeFunction> */
+#define RESCHEDULE_TDD   0x34       /* <RescheduleFunction> */
+#define DISPATCH_TDD     0x35       /* <DispatchFunction> */
+#define PREVIEW_TDD      0x36       /* <PreviewFunction> */
+#define PRINT_TDD        0x40       /* <PrintFunction> */
+#define CONVERT_TDD      0x41       /* <ConvertFunction> */
+#define CHECK_TDD        0x42       /* <CheckFunction> */
+#define EXTEND_TDD       0x50       /* <ExtendFunction> */
+#define NATIONAL_TDD     0x60       /* <NationalFunction> */
+#define PRIVATE_TDD      0x70       /* <PrivateFunction> */
+
+/**
+ *      Constants used for struct extend_tdd_inp
+ */
+
+/*      subfunction field */
+#define POLL_FX3         0x0101     /* FX3: Poll */
+
+#define ENCODE_IPM       0x2010     /* EMAIL: EncodeIPM */
+#define DECODE_IPM      0x2011     /* EMAIL: DecodeIPM */
+
+/**
+ *      Type definitions
+ *      Some types are service dependent. Their values might be restricted or expanded upon further.
+ */
+
+```
+
+```
+
+/*
+**      Address_type
+**      Some telecommunication services may constrain or expand this type furthermore.
+*/
+
+typedef CHAR Address_type[127+1];
+
+/*
+**      Boolean_type
+**      Takes the values true or false
+*/
+
+typedef enum { false=0, true } Boolean_type;
+
+/*
+**      Comid type
+*/
+
+typedef CHAR Comid type[31+1];
+
+/*
+**      Comment type
+*/
+
+typedef CHAR Comment type[127+1];
+
+/*
+**      Convert_id_type
+**      The (asciiz) strings assigned for text based encoding shall be used.
+*/
+
+typedef CHAR Convert_id_type[15+1];
+
+/*
+**      Date_time_type and Send_time_type
+**      The date and time specification follows closely the ANSI specification
+**      The values "IMMEDIATE" and "URGENT" are set by specifying the seconds
+**      part of the struct below (tm_sec) with (-1) or (-2)
+*/
+
+typedef struct {
+    INT16          tm_sec;          /* seconds; used for "IMMEDIATE" and "URGENT"
+    specification */
+    INT16          tm_min;          /* minutes */
+    INT16          tm_hour;         /* hours */
+    INT16          tm_mday;         /* day of month */
+    INT16          tm_mon;          /* month */
+    INT16          tm_year;         /* full year */
+} Date_time_type;
+
+#define Send_time_type      Date_time_type
+#define IMMEDIATE          (-1)      /* Set into tm_sec of above struct */
+#define URGENT              (-2)
+
+/*
+**      Error_type
+**      The definition of the Error type does not include the text part of the error message; If the text
+**      part is needed, it shall be treated as a private extension!
+*/
+
+typedef UINT32 Error_type;
+
+```
+
+```
+
+/*
+**      La_id_type
+**      Reference of an LA-ID. Presented as a string.
+**      The purpose of the parameter is to identify the "owning" LA of a request.
+*/
+
+typedef CHAR La_id_type[15+1];
+
+/*
+**      Layout_id_type
+**      Defines the layout of the <CopyTDD> target file.
+*/
+
+typedef enum {std=0, csv, tab } Layout_id_type;
+
+/*
+**      Path_type
+**      Full path addressing a file of a directory. Stands for full path to document, file or directory.
+**      Full path means: path given absolute, without relative components.
+*/
+
+typedef CHAR Path_type[255+1];
+
+/*
+**      Printer_id_type
+**      ID of selected printer. Represented as a string. Depends on the supporting operating system.
+**      The CA manufacturer shall state in documentation how to address printers.
+*/
+
+typedef CHAR Printer_id_type[127+1];
+
+/*
+**      Req_id_type
+**      Reference of a Request ID. The parameter value is represented as a string encoded as implied
+**      by the APPLI/COM header ID of the TDD. The purpose of the parameter is to identify the
+**      relation of a response to a previous request. So the REQ-ID shall be unique within an LA. It is the
+**      responsibility of the LA to ensure the REQ-ID is unique.
+*/
+
+typedef CHAR Req_id_type[31+1];
+
+/*
+**      Service_type
+**      Specifies the ITU-T Service to be used.
+*/
+
+typedef enum { fx3=1, fx4, ttx, tlx, tx, email, ft } Service_type;
+
+/*
+**      State_type
+**      Specifies the state of the CA-Record. See also Error! Reference source not found..
+*/
+
+typedef enum { delayed=1, sending, sent, send_failed, reception, retrieved, receive_failed } State_type;
+
+/*
+**      Status_type
+*/
+
+typedef enum { unknown, positive, partial, negative } Status_type;
+
+```
+
+```
+
+/*
+**      Subfunc_type
+*/
+
+```
+
+```
+
+typedef UINT32 Subfunc_type;
+
+```
+
+```
+
+/*
+**      Type_id_type
+**      Specifies the Type (Subtype) of a telecommunications service. Each telecommunications
+**      service has its own set of Type-ids. See appropriate clause of Part Error! Reference source not found. of this Recommendation.
+*/
+
+```
+
+```
+
+typedef enum{ std=0, btm, dtm, bft, edi, opd, md, ctl, teletex, g3fax, g4class1, videotex, message, bilateral,
+              national, oda } Type_id_type;
+
+```
+
+```
+
+/*
+**      Userkey_type
+*/
+
+```
+
+```
+
+typedef CHAR_Userkey_type[31+1];
+
+```
+
+#### 18.1.4 FX3 dependent TDD Structures, Constants and Definitions
+
+```
+
+/**
+ *      FX3: Service specific structure for <SendTDD>
+ ***/
+
+```
+
+```
+
+struct send_fx3_inp {
+    G3_speed_type      g3speed;      /* <G3Speed> */
+    Boolean_type        gencil;       /* <GenCil> */
+    G3_high_res_type   highres;       /* <HighRes> */
+    G3_sub_address_type subaddr;      /* <SubAddress> */
+    Boolean_type        useecm;       /* <UseEcm> */
+    Address_type        address;      /* <Recipient> or <RecipientSpec> */
+    Boolean_type        dopoll;       /* <DoPoll> */
+    Poll_password_type  password;     /* <PollPassword> */
+    Poll_select_type    select;       /* <PollSelector> */
+    Path_type           filename;     /* <Document> or <DocumentSpec> */
+    Convert_id_type     convert;      /* <Convert> */
+    Type_id_type        type;         /* <Type> */
+    INT16               from;         /* <From> */
+    INT16               to;           /* <To> */
+};
+
+```
+
+```
+
+/**
+ *      FX3: Service specific structures for <SendAckTDD>
+ ***/
+
+```
+
+```
+
+struct sendack_fx3_inp {
+    G3_speed_type      g3speed;      /* <G3Speed> */
+    Boolean_type        gencil;       /* <GenCil> */
+    G3_high_res_type    highres;      /* <HighRes> */
+    G3_sub_address_type subaddr;      /* <SubAddress> */
+    Boolean_type        useecm;       /* <UseEcm> */
+    Address_type        address;      /* <Recipient> */
+    Boolean_type        dopoll;       /* <DoPoll> */
+    Poll_password_type  password;     /* <PollPassword> */
+    Poll_select_type    select;       /* <PollSelector> */
+    Path_type           filename;     /* <Document> or <DocumentSpec> */
+    Convert_id_type     convert;      /* <Convert> */
+    Type_id_type        type;         /* <Type> */
+    INT16               from;         /* <From> */
+    INT16               to;           /* <To> */
+};
+
+```
+
+```
+
+struct sendack_fx3_out {
+    Address_type        address;      /* <Recipient> */
+    G3_speed_type      g3speed;      /* <G3Speed> */
+    Boolean_type        useecm;       /* <UseEcm> */
+};
+
+```
+
+```
+
+/****
+*      FX3: Service specific structures for <ReceiveTDD>
+****/
+
+```
+
+```
+
+struct receive_fx3_inp {
+    Convert_id_type     cvfax3;       /* <CvFax3> */
+    G3_sub_address_type subaddr;      /* <SubAddress> */
+    Path_type           filename;     /* <Document> */
+};
+
+```
+
+```
+
+struct receive_fx3_out {
+    Address_type        address;      /* <Originator> */
+    G3_speed_type      g3speed;      /* <G3Speed> */
+    G3_sub_address_type subaddr;      /* <SubAddress> */
+    Path_type           filename;     /* <Document> or <DocumentSpec> */
+    Convert_id_type     convert;      /* <Convert> */
+    Type_id_type        type;         /* <Type> */
+};
+
+```
+
+```
+
+/****
+*      FX3: Structures for poll <ExtendTDD>
+****/
+
+```
+
+```
+
+struct poll_fx3_inp {
+    Address_type        address;      /* <Address> */
+    Poll_password_type  password;     /* <PollPassword> */
+    Poll_select_type    select;       /* <PollSelector> */
+    Date_time_type      sendtime;     /* <SendTime> (optional) */
+};
+
+```
+
+```
+
+struct poll_fx3_out {
+    Comid_type          comid;        /* <ComId> */
+};
+
+```
+
+```
+
+/* 
+ * Constants to be used for specific fields of the Send, Sendack and Receive TDD.
+ * Use of some definitions made in 18.1.3 are restricted. This applies to the following
+ * definitions:
+ *
+ *     Service_type is restricted to:    fx3.
+ *     Type_id_type is restricted to:    std, btm, dtm, bft and edi.
+ *     Convert_id_type:                  See Table 78 for further information.
+ */
+
+```
+
+```
+
+/*
+**      G3_speed_type
+*/
+
+```
+
+```
+typedef enum {bps2400=1, bps4800, bps7200, bps9600, bps12200, bps14400} G3_speed_type;
+```
+
+```
+
+/*
+**      G3_sub_address_type
+*/
+
+```
+
+```
+typedef CHAR G3_sub_address_type[23+1];
+```
+
+```
+
+/*
+**      G3_high_res_type
+*/
+
+```
+
+```
+typedef enum {g3dpi98=0, g3dpi196, g3dpi200, g3dpi300, g3dpi400, g3dpi392_8, g3dpi392_16 }
+    G3_high_res_type;
+```
+
+```
+
+/*
+**      Poll_password_type
+*/
+
+```
+
+```
+typedef CHAR Poll_password_type[23+1]; /* only first 20 digits are valid */
+```
+
+```
+
+/*
+**      Poll_select_type
+*/
+
+```
+
+```
+typedef CHAR Poll_password_type[23+1]; /* only first 20 digits are valid */
+```
+
+#### 18.1.5 FX4 dependent TDD Structures, Constants and Definitions
+
+```
+
+/**
+ *      FX4: Service specific structure for <SendTDD>
+ ***/
+
+```
+
+```
+
+struct send_fx4_inp {
+    G4_high_res_type      highres;      /* <HighRes> */
+    G4_sub_address_type    subaddr;      /* <SubAddress> */
+    Address_type           address;      /* <Recipient> or <RecipientSpec> */
+    Path_type              filename;     /* <Document> or <DocumentSpec> */
+    Convert_id_type        convert;      /* <Convert> */
+    Type_id_type           type;         /* <Type> */
+    String12_type          name;         /* <Name> */
+    String12_type          userinfo;     /* <UserInfo> */
+    Path_type              prolog;       /* <Prolog> */
+    INT16                  from;         /* <From> */
+    INT16                  to;           /* <To> */
+};
+
+```
+
+```
+
+/**
+ *      FX4: Service specific structures for <SendAckTDD>
+ ***/
+
+```
+
+```
+
+struct sendack_fx4_inp {
+    G4_high_res_type      highres;      /* <HighRes> */
+    G4_sub_address_type    subaddr;      /* <SubAddress> */
+    Address_type           address;      /* <Recipient> */
+    Path_type              filename;     /* <Document> or <DocumentSpec> */
+    Convert_id_type        convert;      /* <Convert> */
+    Type_id_type           type;         /* <Type> */
+    String12_type          name;         /* <Name> */
+    String12_type          userinfo;     /* <UserInfo> */
+    Path_type              prolog;       /* <Prolog> */
+    INT16                  from;         /* <From> */
+    INT16                  to;           /* <To> */
+};
+
+```
+
+```
+
+struct sendack_fx4_out {
+    Cil_type              cil;          /* <Cil> */
+};
+
+```
+
+```
+
+/**
+ *      FX4: Service specific structures for <ReceiveTDD>
+ ***/
+
+```
+
+```
+
+struct receive_fx4_inp {
+    Convert_id_type        cvfax4;      /* <CvFax4> */
+    G4_sub_address_type    subaddr;      /* <SubAddress> */
+    Path_type              filename;     /* <Document> */
+    Path_type              prolog;       /* <Prolog> */
+};
+
+```
+
+```
+
+struct receive_fx4_out {
+    Address_type           address;      /* <Originator> */
+    G4_sub_address_type    subaddr;      /* <SubAddress> */
+    Path_type              filename;     /* <Document> or <DocumentSpec> */
+    Convert_id_type        convert;      /* <Convert> */
+    Type_id_type           type;         /* <Type> */
+    String12_type          name;         /* <Name> */
+    String12_type          userinfo;     /* <UserInfo> */
+    Cil_type              cil;          /* <Cil> */
+    INT16                  firstpg;      /* <FirstPg> */
+};
+
+```
+
+```
+
+/***
+*      Constants to be used for specific fields of the Send, Sendack and Receive TDD.
+*      Use of some definitions made in 18.1.3 are restricted. This applies to the following
+*      definitions:
+*
+*          Service_type is restricted to:    fx4.
+*          Type_id_type is restricted to:    std, dtm, bft, edi, opd, md, and ctl.
+*          Convert_id_type:                  See Table 87 for further information.
+***/
+
+```
+
+```
+
+/*
+**      String12_type
+*/
+
+```
+
+```
+
+typedef CHAR String12_type[15+1];
+
+```
+
+```
+
+/*
+**      G4_sub_address_type
+*/
+
+```
+
+```
+
+typedef CHAR G4_sub_address_type[7+1];
+
+```
+
+```
+
+/*
+**      G4_high_res_type
+*/
+
+```
+
+```
+
+typedef enum {g4dpi200=1, g4dpi240, g4dpi300, g4dpi400} G4_high_res_type;
+
+```
+
+```
+
+/*
+**      Cil_type
+*/
+
+```
+
+```
+
+typedef struct {
+    CHAR receiver_tid[24];
+    CHAR sep1;           /* = '/' (slash) */
+    CHAR sender_tid[24];
+    CHAR sep2;           /* = '/' (slash) */
+    CHAR datetime[14];
+    CHAR sep3;           /* = '/' (slash) */
+    CHAR refinfo[7];
+} Cil_type;           /* There is no terminating 0x00; Total length = 72 */
+
+```
+
+#### 18.1.6 TTX dependent TDD Structures, Constants and Definitions
+
+```
+
+/***
+*      TTX: Service specific structure for <SendTDD>
+***/
+
+```
+
+```
+
+struct send_ttx_inp {
+    Ttx_sub_address_type    subaddr;           /* <SubAddress> */
+    Address_type            address;           /* <Recipient> or <RecipientSpec> */
+    Path_type               filename;          /* <Document> or <DocumentSpec> */
+    Convert_id_type         convert;           /* <Convert> */
+    Type_id_type            type;              /* <Type> */
+    String12_type           name;              /* <Name> */
+    String12_type           userinfo;          /* <UserInfo> */
+    Path_type               prolog;            /* <Prolog> */
+    INT16                   from;              /* <From> */
+    INT16                   to;                /* <To> */
+    T61_options_type        t61options;        /* <T61Options> */
+};
+
+```
+
+```
+
+/**
+ *      TTX: Service specific structures for <SendAckTDD>
+ ***/
+
+```
+
+```
+
+struct sendack_ttx_inp {
+    Ttx_sub_address_type    subaddr;    /* <SubAddress> */
+    Address_type            address;    /* <Recipient> */
+    Path_type               filename;    /* <Document> or <DocumentSpec> */
+    Convert_id_type         convert;    /* <Convert> */
+    Type_id_type            type;        /* <Type> */
+    String12_type           name;        /* <Name> */
+    String12_type           userinfo;    /* <UserInfo> */
+    Path_type               prolog;      /* <Prolog> */
+    INT16                   from;        /* <From> */
+    INT16                   to;          /* <To> */
+    T61_options_type;       t61options;  /* <T61Options> */
+};
+
+```
+
+```
+
+struct sendack_ttx_out {
+    Cil_type                cil;        /* <Cil> */
+};
+
+```
+
+```
+
+/**
+ *      TTX: Service specific structures for <ReceiveTDD>
+ ***/
+
+```
+
+```
+
+struct receive_ttx_inp {
+    Convert_id_type         cvttx;      /* <CvTtx> */
+    Ttx_sub_address_type    subaddr;    /* <SubAddress> */
+    Path_type               filename;    /* <Document> */
+    Path_type               prolog;      /* <Prolog> */
+};
+
+```
+
+```
+
+struct receive_ttx_out {
+    Address_type            address;    /* <Originator> */
+    Ttx_sub_address_type    subaddr;    /* <SubAddress> */
+    Path_type               filename;    /* <Document> or <DocumentSpec> */
+    Convert_id_type         convert;    /* <Convert> */
+    Type_id_type            type;        /* <Type> */
+    String12_type           name;        /* <Name> */
+    String12_type           userinfo;    /* <UserInfo> */
+    Cil_type                cil;        /* <Cil> */
+    INT16                   firstpg;    /* <FirstPg> */
+};
+
+```
+
+```
+
+/****
+ *      Constants to be used for specific fields of the Send, Sendack and Receive TDD.
+ *      Use of some definitions made in 18.1.3 are restricted. This applies to the following
+ *      definitions:
+ *
+ *      Service_type is restricted to:      ttx.
+ *      Type_id_type is restricted to:      std, dtm, bft and edi.
+ *      Convert_id_type:                    See Table 94 for further information.
+ ****/
+
+```
+
+```
+
+/*
+ **      String12_type
+ **      See definition of FX4!
+ */
+/*
+ typedef CHAR String12_type[15+1];
+ */
+
+```
+
+```
+
+/*
+ **      Ttx_sub_address_type
+ */
+ typedef CHAR Ttx_sub_address_type[7+1];
+ /*
+
+```
+
+```
+
+ **      Cil_type
+ **      See definition of FX4!
+ */
+ /*
+ typedef struct {
+     CHAR  receiver_tid[24];
+     CHAR  sep1           /* = '/' (slash) */
+     CHAR  sender_tid[24];
+     CHAR  sep2           /* = '/' (slash) */
+     CHAR  datetime[14];
+     CHAR  sep3           /* = '/' (slash) */
+     CHAR  refinfo[7];
+ } Cil_type;
+ */
+
+```
+
+```
+
+/*
+ **      T61_options_type
+ */
+
+```
+
+```
+
+typedef CHAR T61_options_type[15+1];
+
+```
+
+#### 18.1.7 TX dependent TDD Structures, Constants and Definitions
+
+```
+
+/****
+ *      TX: Service specific structure for <SendTDD>
+ ****/
+
+```
+
+```
+
+struct send_tx_inp {
+    Boolean_type        notify;           /* <Notify> */
+    Tx_sub_address_type subaddr;          /* <SubAddress> */
+    Address_type        address;          /* <Recipient> or <RecipientSpec> */
+    Path_type           filename;         /* <Document> or <DocumentSpec> */
+    Convert_id_type     convert;          /* <Convert> */
+    Type_id_type        type;             /* <Type> */
+    INT16               from;             /* <From> */
+    INT16               to;               /* <To> */
+};
+
+```
+
+```
+
+/***
+*      TX: Service specific structures for <SendAckTDD>
+***/
+
+struct sendack_tx_inp {
+    Boolean_type          notify;          /* <Notify> */
+    Tx_sub_address_type  subaddr;         /* <SubAddress> */
+    Address_type         address;         /* <Recipient> */
+    Path_type            filename;        /* <Document> or <DocumentSpec> */
+    Convert_id_type      convert;         /* <Convert> */
+    Type_id_type         type;            /* <Type> */
+    INT16                from;            /* <From> */
+    INT16                to;              /* <To> */
+};
+
+struct sendack_tx_out {};
+
+/***
+*      TX: Service specific structures for <ReceiveTDD>
+***/
+
+struct receive_tx_inp {
+    Convert_id_type      cvtx;            /* <CvTx> */
+    Tx_sub_address_type  subaddr;         /* <SubAddress> */
+    Path_type            filename;        /* <Document> */
+};
+
+struct receive_tx_out {
+    Address_type         address;         /* <Originator> */
+    Tx_sub_address_type  subaddr;         /* <SubAddress> */
+    Path_type            filename;        /* <Document> or <DocumentSpec> */
+    Convert_id_type      convert;         /* <Convert> */
+    Type_id_type         type;            /* <Type> */
+};
+
+/***
+*      Constants to be used for specific fields of the Send, Sendack and Receive TDD.
+*      Use of some definitions made in 18.1.3 are restricted. This applies to the following
+*      definitions:
+*
+*      Service_type is restricted to:    tx.
+*      Type_id_type is restricted to:    std
+*      Convert_id_type is restricted to: "ASCII", "ASCIIxxx", "T.50"
+***/
+
+/*
+**      Tx_sub_address_type
+*/
+
+```
+
+```
+
+typedef CHAR Tx_sub_address_type[7+1];
+
+```
+
+#### 18.1.8 TLX dependent TDD Structures, Constants and Definitions
+
+```
+
+/**
+ * TLX: Service specific structure for <SendTDD>
+ */
+
+```
+
+```
+
+struct send_tlx_inp {
+    Tlx_sub_address_type    subaddr;    /* <SubAddress> */
+    Address_type            address;     /* <Recipient> or <RecipientSpec> */
+    Path_type               filename;    /* <Document> or <DocumentSpec> */
+    Convert_id_type         convert;     /* <Convert> */
+    Type_id_type            type;        /* <Type> */
+    INT16                   from;        /* <From> */
+    INT16                   to;          /* <To> */
+};
+
+```
+
+```
+
+/**
+ * TLX: Service specific structures for <SendAckTDD>
+ */
+
+```
+
+```
+
+struct sendack_tlx_inp {
+    Tlx_sub_address_type    subaddr;    /* <SubAddress> */
+    Address_type            address;     /* <Recipient> */
+    Path_type               filename;    /* <Document> or <DocumentSpec> */
+    Convert_id_type         convert;     /* <Convert> */
+    Type_id_type            type;        /* <Type> */
+    INT16                   from;        /* <From> */
+    INT16                   to;          /* <To> */
+};
+
+```
+
+```
+
+struct sendack_tlx_out {};
+
+```
+
+```
+
+/**
+ * TLX: Service specific structures for <ReceiveTDD>
+ */
+
+```
+
+```
+
+struct receive_tlx_inp {
+    Convert_id_type         cvtlx;       /* <CvTx> */
+    Tlx_sub_address_type    subaddr;     /* <SubAddress> */
+    Path_type               filename;    /* <Document> */
+};
+
+```
+
+```
+
+struct receive_tlx_out {
+    Address_type          address;      /* <Originator> */
+    Tlx_sub_address_type  subaddr;      /* <SubAddress> */
+    Path_type             filename;     /* <Document> or <DocumentSpec> */
+    Convert_id_type       convert;      /* <Convert> */
+    Type_id_type          type;         /* <Type> */
+};
+
+/* 
+ * 
+ * Constants to be used for specific fields of the Send, Sendack and Receive TDD.
+ * Use of some definitions made in 18.1.3 are restricted. This applies to the following
+ * definitions:
+ * 
+ * 
+ *      Service_type is restricted to:    tlx.
+ *      Type_id_type is restricted to:    std
+ *      Convert_id_type is restricted to: "ASCII", "ASCIIxxx", "T.50"
+ */
+
+/*
+ **      Tlx_sub_address_type
+ */
+
+```
+
+```
+
+typedef CHAR Tlx_sub_address_type[7+1];
+
+```
+
+#### 18.1.9 EMAIL dependent TDD Structures, Constants and Definitions
+
+```
+
+/* 
+ * 
+ * EMAIL: Service specific structure for <SendTDD>
+ */
+
+struct send_email_inp {
+    Ipm_id_type       ipm_id;        /* <IpmId> */
+    Path_type         s_recipient;   /* <S-Recipient> */
+    Boolean_type      alternate;     /* <Alternate> (optional) */
+    Cont_type_type    cont_type;     /* <ContType> (optional) */
+    Boolean_type      disclo_rec;    /* <DiscloRec> (optional) */
+    Date_time_type    expirytime;    /* <ExpiryTime> (optional) */
+    Boolean_type      implicit_conv; /* <ImplicitConv> (optional) */
+    Importance_type   importance;    /* <Importance> (optional) */
+    Language_id_type  language;      /* <Language> (optional) */
+    Priority_type     priority;      /* <Priority> (optional) */
+    Path_type         related;       /* <Related> (optional) */
+    Ipm_id_type       reply_id;      /* <ReplyId> (optional) */
+    Date_time_type    replytime;     /* <ReplyTime> (optional) */
+    Path_type         s_originator;  /* <S-Originator> (optional) */
+    Sensitivity_type  sensitivity;   /* <Sensitivity> (optional) */
+    Subject_type      subject;       /* <Subject> (optional) */
+    Userinfo_type     userinfo;      /* <UserInfo> (optional) */
+};
+
+/* 
+ * 
+ * EMAIL:Service specific structures for <SendAckTDD>
+ */
+
+struct sendack_email_inp {
+    Ipm_id_type       ipm_id;        /* <IpmId> */
+    Path_type         s_recipient;   /* <S-Recipient> */
+    Boolean_type      alternate;     /* <Alternate> (optional) */
+    Cont_type_type    cont_type;     /* <ContType> (optional) */
+
+```
+
+```
+
+Boolean_type      disclo_rec;      /* <DiscloRec> (optional) */
+Date_time_type    expirytime;      /* <ExpiryTime> (optional) */
+Boolean_type      implicit_conv;   /* <ImplicitConv> (optional) */
+Importance_type   importance;      /* <Importance> (optional) */
+Language_id_type  language;        /* <Language> (optional) */
+Priority_type      priority;        /* <Priority> (optional) */
+Path_type         related;         /* <Related> (optional) */
+Ipm_id_type       reply_id;        /* <ReplyId> (optional) */
+Date_time_type    replytime;       /* <ReplyTime> (optional) */
+Path_type         s_originator;    /* <S-Originator> (optional) */
+Sensitivity_type  sensitivity;     /* <Sensitivity> (optional) */
+Subject_type      subject;         /* <Subject> (optional) */
+Userinfo_type     userinfo;        /* <UserInfo> (optional) */
+};
+
+```
+
+```
+
+struct sendack_email_out {
+    Msg_sub_id_type    msg_sub_id;  /* <MsgSubId> (optional) */
+    Date_time_type     submittime;   /* <SubmitTime> (optional) */
+};
+
+```
+
+```
+
+/****
+*      EMAIL:Service specific structures for <ReceiveTDD>
+****/
+
+```
+
+```
+
+struct receive_email_inp {
+    Path_type          r_originator; /* <R-Originator> */
+    Path_type          r_recipient;  /* <R-Recipient> */
+    Path_type          related;      /* <Related> (optional) */
+};
+
+```
+
+```
+
+struct receive_email_out {
+    Ipm_id_type        ipm_id;       /* <IpmId> */
+    Cont_type_type     cont_type;    /* <ContType> */
+    Date_time_type     expirytime;   /* <ExpiryTime> */
+    Boolean_type        forwarded;    /* <Forwarded> */
+    Importance_type     importance;   /* <Importance> */
+    Boolean_type        inc_copy;     /* <IncCopy> */
+    Language_id_type    language;    /* <Language> */
+    Priority_type        priority;    /* <Priority> */
+    Ipm_id_type        reply_id;     /* <ReplyId> */
+    Date_time_type     replytime;    /* <ReplyTime> */
+    Sensitivity_type    sensitivity;  /* <Sensitivity> */
+    Subject_type        subject;     /* <Subject> */
+    Date_time_type     submittime;   /* <SubmitTime> */
+    Userinfo_type       userinfo;    /* <UserInfo> */
+};
+
+```
+
+```
+
+/****
+*      EMAIL: Structure of file-record of R-Recipientspec
+****/
+
+```
+
+```
+
+struct r_recipientspec {
+    X_name_type        x_name;
+    R_recipient_type    r_type;
+    Boolean_type        reply;
+    Notify_type         notify;
+    Report_type         report;
+};
+
+```
+
+```
+
+/****
+*      EMAIL: Structure of file-record of S-Recipientspec
+****/
+
+struct s_recipientspec {
+    X_name_type          x_name;
+    S_recipient_type     s_type;
+    Boolean_type         reply;
+    Notify_type          notify;
+    Report_type          report;
+};
+
+/****
+*      EMAIL: Structure of file-record of Originatorspec
+****/
+
+struct originatorspec {
+    X_name_type          x_name;
+    Originator_type      o_type;
+};
+
+/****
+*      EMAIL: Structure of file-record of Relatedspec
+****/
+
+struct relatedspec {
+    lpm_id_type          ipm_id;
+    Relation_type        relation;
+};
+
+/****
+*      Constants to be used for specific fields of the Send, Sendack and Receive TDD.
+*      Use of some definitions made in 18.1.3 are restricted. This applies to the following
+*      definitions:
+*
+*      Service_type is restricted to:      email.
+*      Type_id_type is restricted to:      std, teletex, g3fax, g4class1, videotex, message,
+*                                          bilateral, national
+*      Convert_id_type:                    See Table 113 for further information.
+****/
+
+/*
+**      Cont_type_type
+*/
+
+typedef enum { mhsIPM84=0, mhsIPM88, mhsIPN84, mhsIPN88, mhsDR, cmcIPM, cmcIPN, cmcDR}
+    Cont_type_type;
+
+/*
+**      Importance_type
+*/
+
+typedef enum { low = 0, normal, high } Importance_type;
+
+/*
+**      lpm_id_type
+*/
+
+typedef struct {
+    BYTE    id[63+1];
+    BYTE    oraddress[511+1];
+} lpm_id_type;
+
+```
+
+```
+/*  
+**      Language_id_type  
+*/
+```
+
+```
+typedef CHAR  Language_id_type[5+1];
+```
+
+```
+/*  
+**      Msg_sub_id_type  
+*/
+```
+
+```
+typedef CHAR  Msg_sub_id_type[67+1];
+```
+
+```
+/*  
+**      Priority_type  
+*/
+```
+
+```
+typedef enum { standard=0, nonurgent, urgent } Priority_type;
+```
+
+```
+/*  
+**      Relation_type  
+*/
+```
+
+```
+typedef enum { reference=0, obsolete } Relation_type;
+```
+
+```
+/*  
+**      Subject_type  
+*/
+```
+
+```
+typedef CHAR  Subject_type[127+1];
+```
+
+```
+/*  
+**      Sensitivity_type  
+*/
+```
+
+```
+typedef enum { none=0, personal, privateonly, companyconfidential } Sensitivity_type;
+```
+
+```
+/*  
+**      Userinfo_type  
+*/
+```
+
+```
+typedef CHAR  Userinfo_type[15+1];
+```
+
+```
+/*  
+**      X_name_type  
+*/
+```
+
+```
+typedef struct {  
+    Boolean_type      is_alias;  
+    CHAR              addr_or_alias[511+1];  
+} X_name_type;
+```
+
+```
+/*  
+**      S_recipient_type  
+*/
+```
+
+```
+typedef enum { sndprimary=1, sndcopy, sndblind } S_recipient_type;
+```
+
+```
+
+/*
+**      R_recipient_type
+*/
+
+```
+
+```
+
+typedef enum { recprimary=1, reccopy, recblind, recintended } R_recipient_type;
+
+```
+
+```
+
+/*
+**      Notify_type
+*/
+
+```
+
+```
+
+typedef enum { nonotify=1, notreceived, received, explicit } Notify_type;
+
+```
+
+```
+
+/*
+**      Report_type
+*/
+
+```
+
+```
+
+typedef enum { noreport=1, basic, confirmed } Report_type;
+
+```
+
+```
+
+/*
+**      Originator_type
+*/
+
+```
+
+```
+
+typedef enum { authorizing=1, originator, replyto } Originator_type;
+
+```
+
+#### 18.1.10 FT dependent TDD Structures, Constants and Definitions
+
+```
+
+/**
+ *      FT: Service specific structure for <SendTDD>
+ ***/
+
+```
+
+```
+
+struct send_ft_inp {
+    Environ_type      environ;      /* <Environ> */
+    Password_type     password;     /* <Password> (optional) */
+    Address_type      address;      /* <Recipient> or <RecipientSpec> */
+    Path_type         filename;     /* <Document> or <DocumentSpec> */
+    Convert_id_type   convert;      /* <Convert> */
+    Type_id_type      type;         /* <Type> */
+    Compress_type     compress;     /* <Compress> */
+    Name_type         name;         /* <Name> (optional) */
+};
+
+```
+
+```
+
+/**
+ *      FT: Service specific structures for <SendAckTDD>
+ ***/
+
+```
+
+```
+
+struct sendack_ft_inp {
+    Environ_type      environ;      /* <Environ> */
+    Password_type     password;     /* <Password> (optional) */
+    Address_type      address;      /* <Recipient> */
+    Path_type         filename;     /* <Document> or <DocumentSpec> */
+    Convert_id_type   convert;      /* <Convert> */
+    Type_id_type      type;         /* <Type> */
+    Compress_type     compress;     /* <Compress> */
+    Name_type         name;         /* <Name> (optional) */
+};
+
+```
+
+```
+
+struct sendack_ft_out {};
+
+```
+
+```
+
+/***
+*      FT: Service specific structures for <ReceiveTDD>
+***/
+
+```
+
+```
+
+struct receive_ft_inp {
+    Password_type      password;    /* <Password> (optional) */
+    Path_type          filename;    /* <Document> (optional) */
+};
+
+```
+
+```
+
+struct receive_ft_out {
+    Environ_type        environ;     /* <Environ> */
+    Address_type        address;     /* <Originator> */
+    Path_type           filename;    /* <Document> or <DocumentSpec> */
+    Convert_id_type     convert;     /* <Convert> */
+    Type_id_type        type;        /* <Type> */
+    Compress_type       compress;    /* <Compress> */
+    Name_type           name;        /* <Name> */
+};
+
+```
+
+```
+
+/***
+*      Constants to be used for specific fields of the Send, Sendack and Receive TDD.
+*      Use of some definitions made in 18.1.3 are restricted. This applies to the following
+*      definitions:
+*
+*      Service_type is restricted to:    ft
+*      Type_id_type is restricted to:    std
+*      Convert_id_type:                  std, void.
+***/
+
+```
+
+```
+
+/*
+**      Compress_type
+*      See also 17.2.2.6
+*/
+
+```
+
+```
+
+typedef CHAR Compress_type[7+1];
+
+```
+
+```
+
+/*
+**      Environ_type
+*/
+
+```
+
+```
+
+typedef enum { msdos=1, windows, unix, os2, macos } Environ_type;
+
+```
+
+```
+
+/*
+**      Password_type
+*/
+
+```
+
+```
+
+typedef CHAR Password_type[15+1];
+
+```
+
+```
+
+/*
+**      Name_type
+*/
+
+```
+
+```
+
+typedef CHAR Name_type[15+1];
+
+```
+
+# PART IV – PLATFORM DEPENDENCIES
+
+## 19 Implementation Dependencies
+
+This clause describes the implementation dependencies for the various platforms.
+
+The only platform dependent issue of this Recommendation is the implementation of the Primitive Exchange Method (see 7.3.1). The Primitive Exchange Method provides direct access to the Basic Exchange Method functions described in 7.1. subclause 19.3 describes the implementation of the Primitive Exchange Method for each platform.
+
+The implementation of the Primitive Exchange Method is optional for some platforms, since the more platform independent file exchange method might have been chosen as default exchange method for specific platforms. subclause 19.2 lists the default assignments for the different platforms.
+
+The binary encoding scheme provided in Part III of this Recommendation is *not* platform dependent. However, since for the description of this encoding a generic C-language has been used, the mapping of the generic C data types to the real data types used for a specific platform is given first in 19.1 below.
+
+### 19.1 Mapping of Binary Coded TDD Data Types
+
+See Table 125.
+
+TABLE 125/T.611
+
+**Mapping of generic C data types for the various platforms**
+
+| Platform | Real C type corresponding to generic C data type |                   |      |               |
+|----------|--------------------------------------------------|-------------------|------|---------------|
+|          | INT16                                            | UINT32            | CHAR | BYTE          |
+| MS-DOS   | short int                                        | unsigned long int | char | unsigned char |
+| WINDOWS  | short int                                        | dword             | char | byte          |
+| Unix     | short int                                        | unsigned long int | char | unsigned char |
+| OS/2     | short int                                        | unsigned long int | char | unsigned char |
+| MacOS    | For further study                                |                   |      |               |
+
+### 19.2 Default Exchange Method
+
+See Table 126.
+
+TABLE 126/T.611
+
+**Default Exchange Method assignments for the various platforms**
+
+| Platform | Default Exchange Method   |
+|----------|---------------------------|
+| MS-DOS   | File Exchange Method      |
+| WINDOWS  | Primitive Exchange Method |
+| Unix     | For further study         |
+| OS/2     | For further study         |
+| MacOS    | For further study         |
+
+### 19.3 Implementation of Primitive Exchange Method
+
+The implementation of the Primitive Exchange Method shall be achieved by providing access to the Basic Exchange Method functions, which are described in general in 7.1. To ensure binary compatibility across a specific platform, the rules, data types and function prototypes specified in following subclauses for each platform shall be strictly respected.
+
+To perform properly, the implementation has to rely on certain data structures and constants. The data structures and constants common to all implementations are shown below in C language description:
+
+```
+/*
+**      This generic C language description uses certain generic types which are mapped to
+**      real data types in the platform dependent descriptions further below.
+**      The generic types used are: NUMBER, BUFPOINTER, LISTPOINTER and WORD.
+*/
+
+/**
+*      The structure bem_data_buffer describes a buffer.
+*      The types NUMBER and BUFPOINTER have to be mapped to each platform
+***/
+
+struct bem_data_buffer {
+    NUMBER            buffer_size;
+    BUFPOINTER        buffer;
+};
+
+/**
+*      The structure bem_data_files describes a list of filenames.
+*      The types NUMBER and LISTPOINTER have to be mapped to each platform
+***/
+
+struct bem_data_files {
+    NUMBER            number_of_files;
+    LISTPOINTER        file_name[ ];
+};
+
+/**
+*      The structure bem_data_descriptor describes the data conveyed between LAs and CAs
+*      (data files, address lists etc.). The data may be in files and/or in memory. The structure
+*      bem_data_descriptor accounts for these situations.
+*
+*      When data are in memory, the structure bem_data_descriptor allows to actually convey that
+*      data through the EPutData or EGetData functions. When data are in files, bem_data_descriptor
+*      describes the actual file names that contain that data, i.e., the structure does not contain the data
+*      itself.
+*
+*      The type WORD denotes a 16 bit unsigned integer, which has to be mapped to each platform
+***/
+
+struct bem_data_descriptor {
+    WORD            key;                /* key = 0 for data in buffer */
+                                        /* key = 1 for data in file */
+    WORD            type;               /* type = 1 for "document lists" */
+                                        /* type = 2 for "recipient lists", etc.*/
+                                        /* used only in SEND, SENDACK and RECEIVE */
+                                        /* ignored otherwise */
+    union {
+        struct bem_data_buffer buffer;    /* data in memory buffer */
+        struct bem_data_files file;       /* data in file */
+    } bof;                               /* buffer or file */
+};
+```
+
+```
+
+#define BEM_DATA      struct bem_data_descriptor
+
+/* Constants used for the "key" field of BEM_DATA */
+#define BUFFER_KEY      0      /* key: data in buffer */
+#define FILE_KEY        1      /* key: data in file */
+
+/* Constants used for the "type" field of BEM_DATA */
+#define DOCUMENT_TYPE   1      /* type: document list */
+#define RECIPIENT_TYPE  2      /* type: recipient list (= address list) */
+#define ORIGINATOR_TYPE 3      /* type: originator list */
+#define RELATED_TYPE    4      /* type: related list */
+
+/* Constants used for TDD Types, see also 7.2.4.2 */
+#define NO_TDD_RESPONSE 0x00
+#define SENDACK_RESPONSE 0x10
+#define RECEIVE_RESPONSE 0x20
+#define COPY_RESPONSE    0x30
+#define DELETE_RESPONSE  0x31
+#define CANCEL_RESPONSE  0x32
+#define PURGE_RESPONSE    0x33
+#define RESCHEDULE_RESPONSE 0x34
+#define DISPATCH_RESPONSE 0x35
+#define PREVIEW_RESPONSE  0x36
+#define PRINT_RESPONSE    0x40
+#define CONVERT_RESPONSE   0x41
+#define CHECK_RESPONSE     0x42
+#define EXTEND_RESPONSE    0x50
+#define NATIONAL_RESPONSE  0x60
+#define PRIVATE_RESPONSE   0x70
+
+/* Constants used for Alarm_types (may be or'ed), see also 7.2.7.1 */
+#define ASYNC_RESPONSES  0x0001
+#define QUEUE_FULL       0x0002
+#define DOCUMENT_RECEIVED 0x0004
+#define CONNECTION_LOST  0x0008
+#define SEND_SUCCESS     0x0010
+#define SEND_FAILED      0x0020
+#define CORRUPTED_TDD    0x0040
+#define SEND_EVENT       0x0080
+#define RECEIVE_EVENT    0x0100
+#define CA_WILL_STOP     0x0200
+#define ALARMS_UNAVAILABLE 0x0400
+#define TDD_RESP_AVAILABLE 0x0800
+
+```
+
+NOTE – Handling the Data-ID parameter in function EPutTDD for input and output. On input: the LA sets a non-NULL address if the LA needs to transfer data files in subsequent EPutData function calls. If the LA needs not to transfer files, then this parameter is set to NULL. On Output: if the input parameter was set to NULL, the CA does not change that value. Otherwise the CA computes a Data-ID and returns it at the address specified in the input.
+
+#### 19.3.1 MSDOS
+
+Access to the Basic Exchange Method shall occur through a DOS interrupt mechanism. The following rules shall be respected by the calling LA:
+
+- the interrupt number used by the CA shall be taken from the ICE (CA-Descriptor);
+- if a multiplex scheme is used, the multiplex number shall be taken from the ICE (CA-Descriptor) and loaded into register AH before call;
+
+- all parameters shall be transferred to the CA by pushing them onto the caller's stack. The stack shall have at least 256 bytes of headroom when calling;
+- the parameters shall be pushed using C-call conventions (from right to left), pointers shall be pushed as double-word addresses (far pointers);
+- the addressing of a desired function shall be achieved through a function code, also pushed onto the caller's stack as leftmost parameter;
+- the return value shall be passed in the AX register;
+- the segment registers (as well as the stack-pointer) shall be preserved by the CA during call; all other registers may be destroyed by the CA;
+- the stack cleanup (popping of the calling parameters) shall be performed by the caller after function return (C-language calling convention).
+
+To address the various functions the function codes defined in Table 127 shall be used.
+
+TABLE 127/T.611  
+DOS function codes
+
+| Basic Exchange Method Function | Function code |
+|--------------------------------|---------------|
+| ELogin ( )                     | 1             |
+| EPutTDD ( )                    | 2             |
+| EPutData ( )                   | 3             |
+| EPollTDD ( )                   | 4             |
+| ETGetTDD ( )                   | 5             |
+| ETGetData ( )                  | 6             |
+| ESetAlarm ( )                  | 7             |
+| EAbortData ( )                 | 8             |
+| ETLogout ( )                   | 9             |
+
+##### 19.3.1.1 C Function Prototypes and Definitions
+
+```
+#define STATUS      short int
+```
+
+```
+#define BEM_DATA    struct bem_data_descriptor
+```
+
+```
+struct bem_data_buffer {
+    unsigned long          buffer_size;          /* = generic type NUMBER */
+    unsigned char far *    buffer;               /* = generic type BUFPOINTER */
+};
+```
+
+```
+struct bem_data_files {
+    unsigned long          number_of_files;       /* = generic type NUMBER */
+    char far *             file_name[ ];         /* = generic type LISTPOINTER */
+};
+```
+
+```
+
+struct bem_data_descriptor {
+    unsigned short int      key;                /* = generic type WORD */
+    unsigned short int      type;               /* = generic type WORD */
+    union {
+        struct bem_data_buffer buffer;
+        struct bem_data_files file;
+    } bof;
+};
+
+```
+
+\*\*\*/
+
+\* ELogin ( )
+
+\*
+
+|                |               |                                                  |
+|----------------|---------------|--------------------------------------------------|
+| * Stack: SP+18 | Connection_ID | far pointer                                      |
+| * SP+14        | CA_ID         | far pointer                                      |
+| * SP+10        | Selector      | far pointer                                      |
+| * SP+6         | Password      | far pointer                                      |
+| * SP+2         | Login_name    | far pointer                                      |
+| * SP -->       | 0x0001        | word value; function code to identify ELogin ( ) |
+
+\*\*\*/
+
+```
+
+STATUS      ELogin (
+    short int      function_code,          /* ELogin = 0x0001 */
+    char far *     Login_name,
+    char far *     Password,
+    char far *     Selector,
+    short int far * CA_ID,
+    short int far * Connection_ID
+);
+
+```
+
+\*\*\*/
+
+\* EPutTDD ( )
+
+\*
+
+|                |               |                                                   |
+|----------------|---------------|---------------------------------------------------|
+| * Stack: SP+12 | Data_ID       | far pointer                                       |
+| * SP+10        | TDD_size      | word value                                        |
+| * SP+6         | TDD_location  | far pointer                                       |
+| * SP+4         | CA_ID         | word value                                        |
+| * SP+2         | Connection_ID | word value                                        |
+| * SP -->       | 0x0002        | word value; function code to identify EPutTDD ( ) |
+
+\*
+
+\* If the address of Data\_ID is set to NULL on call, CA will not provide the Data\_ID and process the TDD immediately, assuming the pathes given in the TDD are correct
+
+\*\*\*/
+
+```
+
+STATUS      EPutTDD (
+    short int      function_code,          /* EPutTDD = 0x0002 */
+    short int      Connection_ID,
+    short int      CA_ID,
+    unsigned char far * TDD_location,
+    short int      TDD_size,
+    unsigned long far * Data_ID
+);
+
+```
+
+\*\*\*/
+
+\* EPutData ( )
+
+\*
+
+|          |        |               |                                                    |
+|----------|--------|---------------|----------------------------------------------------|
+| * Stack: | SP+14  | Next          | word value                                         |
+| *        | SP+10  | Data          | far pointer                                        |
+| *        | SP+6   | Data_ID       | dword value                                        |
+| *        | SP+4   | CA_ID         | word value                                         |
+| *        | SP+2   | Connection_ID | word value                                         |
+| *        | SP --> | 0x0003        | word value; function code to identify EPutData ( ) |
+
+\*\*\*/
+
+STATUS EPutData (
+
+|                |                |                         |
+|----------------|----------------|-------------------------|
+| short int      | function_code, | /* EPutData = 0x0003 */ |
+| short int      | Connection_ID, |                         |
+| short int      | CA_ID,         |                         |
+| unsigned long  | Data_ID,       |                         |
+| BEM_DATA far * | Data,          |                         |
+| short int      | Next           |                         |
+
+);
+
+\*\*\*/
+
+\* EPollTDD ( )
+
+\*
+
+|          |        |               |                                                    |
+|----------|--------|---------------|----------------------------------------------------|
+| * Stack: | SP+14  | TDD_count     | far pointer                                        |
+| *        | SP+10  | TDD_size      | far pointer                                        |
+| *        | SP+6   | TDD_type      | far pointer                                        |
+| *        | SP+4   | CA_ID         | word value                                         |
+| *        | SP+2   | Connection_ID | word value                                         |
+| *        | SP --> | 0x0004        | word value; function code to identify EPollTDD ( ) |
+
+\*\*\*/
+
+STATUS EPollTDD (
+
+|                      |                |                         |
+|----------------------|----------------|-------------------------|
+| short int            | function_code, | /* EPollTDD = 0x0004 */ |
+| short int            | Connection_ID, |                         |
+| short int            | CA_ID,         |                         |
+| unsigned short far * | TDD_type,      |                         |
+| short int far *      | TDD_size,      |                         |
+| short int far *      | TDD_count      |                         |
+
+);
+
+\*\*\*/
+
+\* EGetTDD ( )
+
+\*
+
+|          |        |               |                                                   |
+|----------|--------|---------------|---------------------------------------------------|
+| * Stack: | SP+14  | Data_ID       | far pointer                                       |
+| *        | SP+10  | TDD_size      | far pointer                                       |
+| *        | SP+6   | TDD_location  | far pointer                                       |
+| *        | SP+4   | CA_ID         | word value                                        |
+| *        | SP+2   | Connection_ID | word value                                        |
+| *        | SP --> | 0x0005        | word value; function code to identify EGetTDD ( ) |
+
+\*\*\*/
+
+```
+
+STATUS      EGetTDD (
+short int      function_code,          /* EGetTDD = 0x0005 */
+short int      Connection_ID,
+short int      CA_ID,
+unsigned char far * TDD_location,
+short int far * TDD_size,
+unsigned long far * Data_ID
+);
+
+```
+
+\*\*\*/
+
+```
+
+*      EGetData (
+
+```
+
+\*
+
+|   |        |        |               |                                                    |
+|---|--------|--------|---------------|----------------------------------------------------|
+| * | Stack: | SP+14  | Next          | far pointer                                        |
+| * |        | SP+10  | Data          | far pointer                                        |
+| * |        | SP+6   | Data_ID       | dword value                                        |
+| * |        | SP+4   | CA_ID         | word value                                         |
+| * |        | SP+2   | Connection_ID | word value                                         |
+| * |        | SP --> | 0x0006        | word value; function code to identify EGetData ( ) |
+
+\*\*\*/
+
+```
+
+STATUS      EGetData (
+short int      function_code,          /* EGetData = 0x0006 */
+short int      Connection_ID,
+short int      CA_ID,
+unsigned long   Data_ID,
+BEM_DATA far * Data,
+short int far * Next
+);
+
+```
+
+\*\*\*/
+
+```
+
+*      ESetAlarm (
+
+```
+
+\*
+
+|   |        |        |               |                                                     |
+|---|--------|--------|---------------|-----------------------------------------------------|
+| * | Stack: | SP+8   | Alarm_handler | far pointer                                         |
+| * |        | SP+6   | Alarm_event   | word value                                          |
+| * |        | SP+4   | CA_ID         | word value                                          |
+| * |        | SP+2   | Connection_ID | word value                                          |
+| * |        | SP --> | 0x0007        | word value; function code to identify ESetAlarm ( ) |
+
+\*\*\*/
+
+```
+
+void      FAR AlarmHandler (
+short int      Connection_ID,
+short int      CA_ID,
+unsigned short  Alarm_type,
+unsigned char far * Parameter,          /* additional parameter buffer */
+short int      Length                  /* length of parameter buffer */
+);
+
+```
+
+```
+
+STATUS      ESetAlarm (
+short int      function_code,          /* ESetAlarm = 0x0007 */
+short int      Connection_ID,
+short int      CA_ID,
+unsigned short  Alarm_event,
+void (* far    Alarm_handler) ( )
+);
+
+```
+
+```
+
+***/
+*      EAbortData ( )
+*
+*      Stack:  SP+6      
+
+|         |
+|---------|
+| Data_ID |
+|---------|
+
+      dword value
+*                  SP+4      
+
+|       |
+|-------|
+| CA_ID |
+|-------|
+
+      word value
+*                  SP+2      
+
+|               |
+|---------------|
+| Connection_ID |
+|---------------|
+
+      word value
+*                  SP -->      
+
+|        |
+|--------|
+| 0x0008 |
+|--------|
+
+      word value; function code to identify EAbortData ( )
+***/
+
+```
+
+```
+
+STATUS      EAbortData (
+              short int      function_code,      /* EAbortData = 0x0008 */
+              short int      Connection_ID,
+              short int      CA_ID,
+              unsigned long   Data_ID
+);
+
+```
+
+```
+
+***/
+*      ELogout ( )
+*
+*      Stack:  SP+4      
+
+|       |
+|-------|
+| CA_ID |
+|-------|
+
+      word value
+*                  SP+2      
+
+|               |
+|---------------|
+| Connection_ID |
+|---------------|
+
+      word value
+*                  SP -->      
+
+|        |
+|--------|
+| 0x0009 |
+|--------|
+
+      word value; function code to identify ELogout ( )
+***/
+
+```
+
+```
+
+STATUS      ELogout (
+              short int      function_code,      /* ELogout = 0x0009 */
+              short int      Connection_ID,
+              short int      CA_ID
+);
+
+```
+
+#### 19.3.2 WINDOWS
+
+To access the Basic Exchange Method functions, the CA provider shall offer a Dynamic Link Library (DLL), which opposes the Exchange Method functions described in the following subclause to the LA.
+
+The Name of the DLL shall be stated at the appropriate place in the ICE by the configurator of the target platform. In order to access the DLL functions, the LA shall first issue a Windows "LoadLibrary" system function call, using the name of the chosen DLL parameter.
+
+##### 19.3.2.1 C Function Prototypes and Definitions
+
+```
+#include <windows.h>
+```
+
+```
+#define BEM_DATA      struct bem_data_descriptor
+```
+
+```
+
+struct bem_data_buffer {
+    int      buffer_size;      /* = generic type NUMBER */
+    HANDLE    buffer;          /* = generic type BUFPOINTER */
+};
+
+```
+
+```
+
+struct bem_data_files {
+    int      number_of_files;  /* = generic type NUMBER */
+    LPSTR    file_name[1];    /* = generic type LISTPOINTER */
+};
+
+```
+
+```
+
+struct bem_data_descriptor {
+    word                key;                /* = generic type WORD */
+    word                type;              /* = generic type WORD */
+    union {
+        struct bem_data_buffer buffer;
+        struct bem_data_files file;
+    } bof;
+};
+
+/**
+ *      ELogin ( )
+ ***/
+
+void FAR PASCAL ELogin (
+    LPSTR                Login_name,        /* User name */
+    LPSTR                Password,          /* User's password */
+    LPSTR                Selector,          /* CA Selector */
+    int far *            CA_ID,             /* CA Identifier */
+    int far *            Connection_ID,     /* Connection ID */
+    int far *            Status             /* 0 success, 1 fail */
+);
+
+/**
+ *      EPutTDD ( )
+ *
+ *      If the address of Data_ID is set to NULL on call, CA will not provide the Data_ID and process
+ *      the TDD immediately, assuming the pathes given in the TDD are correct
+ ***/
+
+void FAR PASCAL EPutTDD (
+    int                  Connection_ID,     /* Connection ID */
+    int                  CA_ID,             /* CA Identifier */
+    LPSTR                TDD_location,     /* TDD buffer text */
+    int                  TDD_size,          /* size of the TDD text */
+    int far *            Data_ID,           /* Data identifier */
+    int far *            Status             /* 0 success, 1 fail */
+);
+
+/**
+ *      EPutData ( )
+ ***/
+
+void FAR PASCAL EPutData (
+    int                  Connection_ID,     /* Connection ID */
+    int                  CA_ID,             /* CA Identifier */
+    int                  Data_ID,           /* Data identifier */
+    BEM_DATA far *      Data,               /* Data descriptor */
+    int                  Next,              /* next boolean */
+    int far *            Status             /* 0 success, 1 fail */
+);
+
+/**
+ *      EPolITDD ( )
+ ***/
+
+```
+
+```
+
+void FAR PASCAL EPollTDD (
+    int                Connection_ID,    /* Connection ID */
+    int                CA_ID,            /* CA Identifier */
+    word far *         TDD_type,         /* Type of next TDD */
+    int far *          TDD_size,         /* Size of next TDD */
+    int far *          TDD_count,        /* Count of waiting TDDs */
+    int far *          Status            /* 0 success, 1 fail */
+);
+
+/****
+*      EGetTDD ( )
+****/
+
+void FAR PASCAL EGetTDD (
+    int                Connection_ID,    /* Connection ID */
+    int                CA_ID,            /* CA Identifier */
+    LPSTR              TDD_location,     /* TDD buffer text */
+    int far *          TDD_size,         /* size of the TDD text */
+    int far *          Data_ID,          /* Data identifier */
+    int far *          Status            /* 0 success, 1 fail */
+);
+
+/****
+*      EGetData ( )
+****/
+
+void FAR PASCAL EGetData (
+    int                Connection_ID,    /* Connection ID */
+    int                CA_ID,            /* CA Identifier */
+    int                Data_ID,          /* Data identifier */
+    BEM_DATA far *     Data,             /* Data descriptor */
+    int far *          Next,             /* next boolean */
+    int far *          Status            /* 0 success, 1 fail */
+);
+
+/****
+*      ESetAlarm ( )
+****/
+
+void FAR PASCAL AlarmHandler (
+    int                Connection_ID,    /* Connection ID */
+    int                CA_ID,            /* CA Identifier */
+    word               Alarm_type,       /* Alarm type */
+    HANDLE              Parameter,       /* additional parameter buffer */
+    int                Length            /* length of parameter buffer */
+);
+
+void FAR PASCAL ESetAlarm (
+    int                Connection_ID,    /* Connection ID */
+    int                CA_ID,            /* CA Identifier */
+    word               Alarm_type,       /* Alarm event */
+    FARPROC             Alarm_handler,   /* Alarm handler entry */
+    int far *          Status            /* 0 success, 1 fail */
+);
+
+```
+
+```
+
+/**
+ *      EAbortData ( )
+ ***/
+
+void FAR PASCAL EAbortData (
+    int          Connection_ID,      /* Connection ID */
+    int          CA_ID,              /* CA Identifier */
+    int          Data_ID,            /* Data identifier */
+    int far *     Status              /* 0 success, 1 fail */
+);
+
+/**
+ *      ELogout ( )
+ ***/
+
+void FAR PASCAL ELogout (
+    int          Connection_ID,      /* Connection ID */
+    int          CA_ID,              /* CA Identifier */
+    int far *     Status              /* 0 success, 1 fail */
+);
+
+```
+
+#### 19.3.3 UNIX
+
+For further study.
+
+#### 19.3.4 OS/2
+
+For further study.
+
+#### 19.3.5 MacOS
+
+For further study.
+
+## Annex A
+
+### Syntax for Presentation and Encoding
+
+(This annex forms an integral part of this Recommendation)
+
+### A.1 BNF-style Syntax
+
+In order to provide a generic description, a BNF-based syntax is used. The general BNF rules described below are employed throughout this Recommendation.
+
+- A terminal token (leaf) is noted by a literal. If the literal cannot be distinguished from the literals used to describe the syntax, then the token shall be enclosed in double quotes (").
+- Strings of characters enclosed in double quote characters denote terminal tokens that consist of the constant text formed by those strings.
+- A non-terminal token (node) is noted by a literal delimited by the "<" (lower than) and ">" (greater than) characters.
+- An optional token (or group of tokens) is delimited with the "[" and "]" characters.
+- A group of tokens is delimited by the "(" and ")" characters. Groups can be nested.
+- A group of tokens enclosed in "{" and "}" may be repeated 0, 1 or more times.
+- The character "|" is used to separate alternative tokens (or groups of tokens).
+
+- The string ":@" is used as the production delimiter.
+- Tokens are separated by space or tabulation characters (or a combination of the two).
+- The string "--" is used to introduce a comment in the BNF description. The comment finishes at the end of the line. BNF comments cannot be nested.
+
+Applied to text based encodings:
+
+- The terminal token STRING denotes a string of characters encoded as implied by the value of the Code-ID (see Table 14). The string of characters may be of a limited size, as stated by the token STRING(SIZE(xxx..yyy)). In this case, xxx denotes the minimum string length, yyy denotes the maximum string length.
+- The special notation "STRING( xxxx + yyyy)" where "xxxx" and "yyyy" are character strings results in a string formed by the concatenation of "xxxx" and "yyyy".
+- The terminal token PATH denotes a STRING containing only characters valid as absolute path specification for the underlying operating system.
+- The terminal token NUMERIC-STRING denotes a string of characters representing a number. Only digits 0 to 9 may be used.
+- The token ↵ indicates that a line break occurs. However, it is possible to include a comment in a TDD by ending the TDD line with a semicolon character, the comment itself, and the line break.
+- The order implied by the production rules in the BNF description may not be the order in which the tokens have to be encoded. The additional rules for the encoding schemes specify the order, if any, that has to be respected.
+
+### A.2 C-Language Notation
+
+The generic C-Language notation used is based on the current ANSI standard. So, if gathered in a file, the descriptions can be compiled by existing ANSI compilers. However, in the operating system dependent sections, application of the appropriate compilers is required. In general, the descriptions are based on following conventions:
+
+- The first 16 characters of definitions and variable names are significant;
+- Upper and lower case are differentiated.
+
+## Annex B
+
+### Location of the ICE
+
+(This annex forms an integral part of this Recommendation)
+
+The Interface Configuration Environment (ICE), represents a "global" source for all local applications (LAs) conforming to this Recommendation.
+
+On the operating systems UNIX, MacOS and the operating systems belonging to the Microsoft family (OS/2, MS-DOS, etc.), the Master ICE is represented by a file<sup>17)</sup>. In a LAN computing environment such as Netware, Vines or LAN Manager, the Master ICE is also presented as a file. This file shall be opened and read by the application in order to extract the information about the CAs accessible within the system. The name of the file on the systems or networks mentioned above is "APPLICOM.ICE".
+
+---
+
+<sup>17)</sup> A "file" in this context means either a real operating system file or an operating system device driver, which behaves exactly as a file.
+
+The Master ICE file is located differently on the above-mentioned systems. On some systems there exists an "environment variable"<sup>18)</sup>, which may hold the path to the ICE. In those cases the variable is named "APPLICOM" (all capitals). The following algorithms for determining the ICE location shall be used (see Table B.1):
+
+TABLE B.1/T.611  
+**Determination of Master ICE location**
+
+| Operating System | Algorithm                                                                                                                                                                                   |
+|------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| UNIX             | First look in the Environment variable "APPLICOM". If there is no variable, then the ICE is located in the /dev subdirectory and named "APPLICOM_ICE"                                       |
+| MacOS            | The ICE is located in the System folder                                                                                                                                                     |
+| MS-DOS           | Look in the Environment variable "APPLICOM". If this variable does not exist, this should be regarded as an error                                                                           |
+| Windows          | File is named "ICE.INI" and located in the local windows directory of the LA system. If this file does not exist, look into file "WIN.INI" in the windows directory, section [APPLICOM_ICE] |
+
+In a LAN computing environment, the Master ICE file should be installed by the system administrator on a shared directory which is accessible by all potential LAs.
+
+Individual CA-Descriptor files or drivers for CAs in a single user or LAN environment do not need to be installed on the same directory as the Master-ICE, but should be placed on directories accessible to all LAs.
+
+The following naming convention shall be used for CA-Descriptor files or drivers:
+
+CA<sub>nnnn</sub>AC.<ext>
+
+where:
+
+nnnn is a number in the range 1..9999
+
+and:
+
+<ext> := ("ini" | "exe" | "dll" | <other>)
+
+"ini" shall be used for the case of a text file, and <other> may be defined by the CA-Manufacturer based upon the naming conventions used within the target computing environment.
+
+Access to the CA-Descriptor(s) for an individual CA shall be defined within the Master-ICE in the form of a path parameter (path plus file name). The default location for the CA-Descriptor if no path is defined shall be upon the same path as the Master-ICE.
+
+<sup>18)</sup> Operating systems like UNIX or MS-DOS provide a so called "Environment" which consists of a set of ASCII strings applied to an ASCII represented variable.
+
+## Annex C
+
+### List of APPLI/COM Error Codes
+
+(This annex forms an integral part of this Recommendation)
+
+Table C.1 states the error codes which shall be used commonly by CA implementations conforming to this Recommendation.
+
+TABLE C.1/T.611
+
+### List of error codes
+
+| Error code <sup>a)</sup> | Error text                        | Comment                                   |
+|--------------------------|-----------------------------------|-------------------------------------------|
+| 0000                     | Success                           | No error – Successfull operation          |
+| 0001-4999                | Private use                       | Reserved for CA private use               |
+| 5000                     | CA Interface Error                |                                           |
+| 5001                     | Unsupported Service specified     |                                           |
+| 5002                     | File "FILENAME" already exists    | CA cannot create or write "FILENAME" file |
+| 5003                     | Error creating "TARGET"           | CA cannot create or write "TARGET" file   |
+| 5004                     | Error reading Address List        |                                           |
+| 5005                     | Error reading Document List       |                                           |
+| 5006                     | Error reading Document            |                                           |
+| 5007                     | Error writing Document            |                                           |
+| 5008                     | "Code-ID" not supported           |                                           |
+| 5009                     | Invalid "Connection-ID"           |                                           |
+| 5010                     | Invalid "CA-ID"                   |                                           |
+| 5011-5499                | Reserved                          | Reserved for further study                |
+| 5500-5999                | Private use                       | Reserved for CA private use               |
+| 6000                     | Syntax Error                      |                                           |
+| 6001                     | Unknown Function requested        |                                           |
+| 6002                     | TDD is empty                      |                                           |
+| 6003                     | APPLI/COM Header is invalid       | Invalid length or contents                |
+| 6004                     | Parser Error (TDD line too long)  |                                           |
+| 6005                     | Parser Error (TDD line too short) |                                           |
+| 6006                     | Multiple Occurencies of Keyword   |                                           |
+| 6007                     | Parameter has wrong Size          |                                           |
+| 6008                     | Keyword ERROR is missing          |                                           |
+| 6009                     | Mandatory Keyword is missing      |                                           |
+| 6010                     | Undefined Keyword                 |                                           |
+| 6011                     | Conflicting Keywords              |                                           |
+| 6012                     | Parameter out of Range            |                                           |
+| 6013                     | Keywords out of Sequence          | Order: FUNCTION, SUBFUNC, others...       |
+| 6014                     | Keyword Separator missing         | Colon (":") is missing                    |
+| 6015                     | Invalid "LA-ID"                   |                                           |
+
+TABLE C.1/T.611 (*end*)
+
+### **List of error codes**
+
+| Error code <sup>a)</sup>             | Error text                                | Comment                                     |
+|--------------------------------------|-------------------------------------------|---------------------------------------------|
+| 6016                                 | Invalid "REQ-ID"                          |                                             |
+| 6017                                 | Invalid "COM-ID"                          |                                             |
+| 6018                                 | Invalid "Service-ID"                      |                                             |
+| 6019                                 | "Type-ID" does not fit to "Service-ID"    |                                             |
+| 6020                                 | "Conversion-ID" does not fit to "Type-ID" |                                             |
+| 6021                                 | "TARGET" File missing                     | Applies to COPY TDD                         |
+| 6022                                 | Invalid Code-ID                           | Allowed are: "A", "B", "C", "E", "I" or "P" |
+| 6023                                 | Incompatible Interface Version            | APPLI/COM Header Version does not fit       |
+| 6024-6499                            | Reserved                                  | Reserved for further study                  |
+| 6500-6999                            | Private use                               | Reserved for CA private use                 |
+| 7000                                 | Hardware/System related Error             |                                             |
+| 7001-7499                            | Reserved                                  | Reserved for further study                  |
+| 7500-7999                            | Private use                               | Reserved for CA private use                 |
+| 8000                                 | Error during Document Conversion          |                                             |
+| 8001                                 | Invalid Transfer Format                   |                                             |
+| 8002                                 | Unexpected End of Document                |                                             |
+| 8003                                 | Unexpected Error accessing Document       |                                             |
+| 8004                                 | Error during T.61 Conversion              |                                             |
+| 8005                                 | Error during ASCII Conversion             |                                             |
+| 8006                                 | Error during TIFF Conversion              |                                             |
+| 8007                                 | Error during T.4 Conversion               |                                             |
+| 8008                                 | Error during T.6 Conversion               |                                             |
+| 8009-8499                            | Reserved                                  | Reserved for further study                  |
+| 8500-8999                            | Private use                               | Reserved for CA private use                 |
+| 9000                                 | Transmission Error                        |                                             |
+| 9001                                 | Connection broken                         |                                             |
+| 9002                                 | Remote Destination busy                   |                                             |
+| 9003                                 | Connection set-up failed                  |                                             |
+| 9006                                 | Transmission Error (Transport Layer)      |                                             |
+| 9007                                 | Transmission Error (Session Layer)        |                                             |
+| 9008                                 | Remote Destination closed Connection      |                                             |
+| 9009                                 | Remote Destination has call denied        |                                             |
+| 9010                                 | Remote Destination not compatible         |                                             |
+| 9011                                 | Transmission Failure – Document Error     |                                             |
+| 9012-9499                            | Reserved                                  | Reserved for further study                  |
+| 9500-9999                            | Private use                               | Reserved for CA private use                 |
+| a) Error codes are given in decimal. |                                           |                                             |
+
+## Annex D
+
+### Examples of TTD Exchanges
+
+(This annex does not form an integral part of this Recommendation)
+
+### D.1 A Sample Send Session
+
+An LA-running on a MS-DOS (or Windows) based system - wants to send a document (which contains graphic information), say the document "c:\dtp\graphic1.tif" to an addressee via facsimile group 3 services. What the LA must do in sequence is:
+
+- look for a CA which is capable of performing the facsimile group 3 service by inspecting the ICE and, if found, perform a Login to that CA by a Login function call (if not already done);
+- prepare the document as an APPL/COM TIFF file (if not already done);
+- build a SEND TDD;
+- hand over the TDD to the CA;
+- repeatedly poll the CA (or waiting for get informed by the alarm function) until the Response-TDD becomes available;
+- retrieve the Response-TDD to learn the status of the transmission;
+- logout of the CA (or) perform other functions with the same CA.
+
+Let us assume that the LA has already logged into the CA and the "c:\dtp\graphic1.tif" file is already prepared in TIFF format. Then the LA has to prepare the Send TDD in its memory. The LA uses the default coding (T.50) for preparation of the TDD. The TDD may look like shown in Figure D.1.
+
+|                                                                                                    |                       |                                     |
+|----------------------------------------------------------------------------------------------------|-----------------------|-------------------------------------|
+| !*APPL/COM*1994*ITU-T*                                                                             |                       |                                     |
+| ; Send a graphics document via facsimile group 3                                                   |                       |                                     |
+| ; Fields into which a value may return are pre-set with underline (5F <sub>HEX</sub> ) characters. |                       |                                     |
+| FUNCTION                                                                                           | : SendAck             | ; Send with response                |
+| LA-ID                                                                                              | : myLA                | ; Name of LA                        |
+| REQ-ID                                                                                             | : g_0815              | ; Request-id, generated by LA       |
+| SERVICE                                                                                            | : FX3                 | ; Facsimile G3 service              |
+| ADDRESS                                                                                            | : 08154711            | ; Recipient                         |
+| FILENAME                                                                                           | : c:\dtp\graphic1.tif | ; Full path to document             |
+| CONVERT                                                                                            | : TIFF                | ; Transfer format                   |
+| COMID                                                                                              | : _____               | ; Unique CA ID (Response)           |
+| STATUS                                                                                             | : _____               | ; Status of transmission (Response) |
+| ERROR                                                                                              | : _____               | ; Error occurred ? (Response)       |
+
+FIGURE D.1/T.611
+
+Once the TDD is prepared, the LA internally calls the basic exchange mechanism function PutTDD which hands over the TDD to the CA.
+
+Then the LA repeatedly polls the CA using the basic exchange mechanism function PollTDD until the Response-TDD becomes available. Using the basic exchange mechanism function GetTDD the LA retrieves the TDD from the CA into its own memory and inspects the results. The Response-TDD could look like shown in Figure D.2.
+
+|                                                                                                    |                       |                                     |
+|----------------------------------------------------------------------------------------------------|-----------------------|-------------------------------------|
+| !*APPLI/COM*1994*ITU-T*                                                                            |                       |                                     |
+| ; Send a graphics document via facsimile group 3                                                   |                       |                                     |
+| ; Fields into which a value may return are pre-set with underline (5F <sub>HEX</sub> ) characters. |                       |                                     |
+| FUNCTION                                                                                           | : SendAck             | ; Send with response                |
+| LA-ID                                                                                              | : myLA                | ; Name of LA                        |
+| REQ-ID                                                                                             | : g_0815              | ; Request-id, generated by LA       |
+| SERVICE                                                                                            | : FX3                 | ; Facsimile G3 service              |
+| ADDRESS                                                                                            | : 0498154711          | ; Recipient                         |
+| FILENAME                                                                                           | : c:\dtp\graphic1.tif | ; Full path to document             |
+| CONVERT                                                                                            | : TIFF                | ; Transfer format                   |
+| COMID                                                                                              | : 123456              | ; Unique CA ID (Response)           |
+| STATUS                                                                                             | : +                   | ; Status of transmission (Response) |
+| ERROR                                                                                              | : 0000/Success        | ; Error occurred ? (Response)       |
+
+FIGURE D.2/T.611
+
+As one can see from the STATUS and ERROR field, the transmission was successful.
+
+### D.2 A Sample Receive Session
+
+An LA running on any operating environment wants to know if there are some documents to be received within a facsimile CA. What the LA must do in the sequence is:
+
+- look for a CA which is capable of performing the facsimile service by inspecting the ICE and, if found, Login into that CA by a Login function call;
+- prepare a receive TDD and hand it to the CA using PutTDD function;
+- repeatedly poll the CA (using the PollTDD function) (or waiting for get informed by a back-called alarm function) until the Response-TDD becomes available;
+- retrieve the Response-TDD (using the GetTDD function) to know the status of the reception;
+- logout of the CA or perform other functions.
+
+The LA uses the default coding (T.50) for preparation of the receive TDD. The TDD may look like the shown in Figure D.3.
+
+|                                                                                                    |               |                                     |
+|----------------------------------------------------------------------------------------------------|---------------|-------------------------------------|
+| I*APPLI/COM*1994*ITU-T*                                                                            |               |                                     |
+| ; Receive a T.4 document via facsimile group 3                                                     |               |                                     |
+| ; Fields into which a value may return are pre-set with underline (5F <sub>HEX</sub> ) characters. |               |                                     |
+| FUNCTION                                                                                           | : Receive     | ; Send with response                |
+| LA-ID                                                                                              | : myLA        | ; Name of LA                        |
+| REQ-ID                                                                                             | : g_0816      | ; Request-id, generated by LA       |
+| SERVICE                                                                                            | : FX3         | ; Facsimile G3 service              |
+| FILENAME                                                                                           | : c:\file.ext | ; Full path to document             |
+| Cvfax3                                                                                             | : TIFF        | ; Desired transfer format           |
+| TypeID                                                                                             | : _____       | ; Status of the received file       |
+| ADDRESS                                                                                            | : _____       | ; Sender's addressee, filled by CA  |
+| CONVERT                                                                                            | : _____       | ; Transfer format                   |
+| COMID                                                                                              | : _____       | ; Unique CA ID (Response)           |
+| STATUS                                                                                             | : _____       | ; Status of transmission (Response) |
+| ERROR                                                                                              | : _____       | ; Error occurred ? (Response)       |
+
+FIGURE D.3/T.611
+
+Having prepared the TDD, the LA internally calls the basic exchange mechanism function PutTDD and hands over the TDD to the CA.
+
+Having done this, the LA repeatedly polls the CA using the basic exchange mechanism function PollTDD until the Response-TDD becomes available. Using the basic exchange mechanism function GetTDD the LA retrieves the TDD from the CA into its own memory and inspects the results. The Response-TDD could look shown in Figure D.4.
+
+|                                                                                                    |                |                                    |
+|----------------------------------------------------------------------------------------------------|----------------|------------------------------------|
+| I*APPLI/COM*1994*ITU-T*                                                                            |                |                                    |
+| ; Receive a T.4 document via facsimile group 3                                                     |                |                                    |
+| ; Fields into which a value may return are pre-set with underline (5F <sub>HEX</sub> ) characters. |                |                                    |
+| FUNCTION                                                                                           | : Receive      | ;Send with response                |
+| LA-ID                                                                                              | : myLA         | ;Name of LA                        |
+| REQ-ID                                                                                             | : g_0816       | ;Request-id, generated by LA       |
+| SERVICE                                                                                            | : FX3          | ;Facsimile G3 service              |
+| FILENAME                                                                                           | : c:\file.ext  | ;Full path to document             |
+| Cvfax3                                                                                             | : TIFF         | ;Desired transfer format           |
+| TypeID                                                                                             | : STD          | ;Status of the received file       |
+| ADDRESS                                                                                            | : 033145782762 | ;Sender's addressee, filled by CA  |
+| CONVERT                                                                                            | : T.4          | ;Transfer format                   |
+| COMID                                                                                              | : 000001       | ;Unique CA ID (Response)           |
+| STATUS                                                                                             | : +            | ;Status of transmission (Response) |
+| ERROR                                                                                              | : 0000/Success | ;Error occurred ? (Response)       |
+
+FIGURE D.4/T.611
+
+As one can see from the STATUS and ERROR field, the reception was received by the CA.
+
+### D.3 A Sample Trace Session
+
+An LA running on any operating environment could have information about the transitory or definitive state of a communication record (CA-Record). What the LA must do in the sequence is:
+
+- look for a CA which is capable of performing any telecommunication service by inspecting the ICE and, if found, Login into that CA by a Login function call;
+- prepare a Trace TDD and hand it to the CA using PutTDD function;
+- repeatedly poll the CA (using the PollTDD function) – or wait to get informed by a back-called alarm function – until the Response-TDD becomes available;
+- retrieve the Response-TDD (using the GetTDD function) to learn the status of the reception;
+- logout of the CA or performing other functions.
+
+The LA uses the default coding (T.50) for preparation of the receive TDD. The TDD may look like as shown in Figure D.5.
+
+|                                                                                                    |               |                               |
+|----------------------------------------------------------------------------------------------------|---------------|-------------------------------|
+| !*APPLI/COM*1994*ITU-T*                                                                            |               |                               |
+| ; Rectieve a list of all CA-Records in sending state                                               |               |                               |
+| ; Fields into which a value may return are pre-set with underline (5F <sub>HEX</sub> ) characters. |               |                               |
+| FUNCTION                                                                                           | : Copy        | ; Send with response          |
+| LA-ID                                                                                              | : myLA        | ; Name of LA                  |
+| REQ-ID                                                                                             | : g_0816      | ; Request-id, generated by LA |
+| State                                                                                              | : sending     | ; CA-Records being processed  |
+| Target                                                                                             | : c:\file.ext | ; Full path to document       |
+| ERROR                                                                                              | : _____       | ; Error occurred ? (Response) |
+
+FIGURE D.5/T.611
+
+Having prepared the TDD, the LA internally calls the basic exchange mechanism function PutTDD and hands over the TDD to the CA.
+
+Having done this, the LA repeatedly polls the CA using the basic exchange mechanism function PollTDD until the Response-TDD becomes available. Using the basic exchange mechanism function GetTDD the LA retrieves all CA-Records in a particular state from the CA. The Response-TDD could look like shown in Figure D.6.
+
+|                                                                                                    |                |                               |
+|----------------------------------------------------------------------------------------------------|----------------|-------------------------------|
+| !*APPLI/COM*1994*ITU-T*                                                                            |                |                               |
+| ; Rectieve a list of all CA-Records in sending state                                               |                |                               |
+| ; Fields into which a value may return are pre-set with underline (5F <sub>HEX</sub> ) characters. |                |                               |
+| FUNCTION                                                                                           | : Copy         | ; Send with response          |
+| LA-ID                                                                                              | : myLA         | ; Name of LA                  |
+| REQ-ID                                                                                             | : g_0816       | ; Request-id, generated by LA |
+| State                                                                                              | : sending      | ; CA-Records being processed  |
+| Target                                                                                             | : c:\file.ext  | ; Full path to document       |
+| ERROR                                                                                              | : 0000/Success | ; Error occurred ? (Response) |
+
+FIGURE D.6/T.611
+
+As one can see from the ERROR field, the copy was received by the CA.
+
+## Annex E
+
+### Example of Interface Configuration Environment (ICE)
+
+(This annex does not form an integral part of this Recommendation)
+
+An example of a Master ICE configuration (located on an MS-DOS based machine as a file) is given in Figure E.1. The example shows a Master ICE which provides access to multiple CAs which support multiple services and access methods.
+
+```
+I*APPLI/COM*1994*ITU-T*MASTER_ICE
+
+; Note that there may be one or more CAs referenced in the Master ICE and that each shall
+; include the keywords APPLICOM; SERVICE; EM and ACCESS.
+; A new CA-Entry is denoted by a "#" (number sign) as shown below.
+
+#                                     ; Beginning of new CA-Entry
+APPLICOM:      Product1 (c) by DonaldDuck      ; CA Product and Manufacturer
+SERVICE:      FX3                             ; supports fax group 3 service
+SERVICE:      EMAIL                           ; supports EMAIL service
+EM:            file                            ; File exchange method
+ACCESS:        CA1AC.INI                       ; File based CA-Descriptor
+
+#                                     ; Beginning of new CA- Header
+APPLICOM:      Product2 (c) by MickeyMouse     ; CA Product and Manufacturer
+SERVICE:      FX3                             ; supports fax group 3 service
+SERVICE:      TLX                             ; supports telex service
+SERVICE:      FT                              ; supports file transfer service
+EM:            primitive                       ; Primitive exchange method
+CA-ID:         007                            ; ID of CA
+ACCESS:        CA2AC.INI                       ; File based CA-Descriptor
+ACCESS:        CA2AC.EXE                       ; CA-Descriptor executable
+ACCESS:        CA2AC.DLL                       ; CA-Descriptor DLL
+```
+
+FIGURE E.1/T.611
+
+### Sample Master ICE
+
+An example of CA-Descriptors (located on a MS-DOS based machine in a file) is given in Figure E.2.
+
+I\*APPLI/COM\*1994\*ITU-T\*ICE
+
+; Note that there may be any type of configuration information which may be stored here.  
+; A new configuration information is always led in by a "#" (number sign) as shown below.
+
+```
+# ; Beginning of new configuration
+APPLICOM:      Product1 (c) by Company XYZ ; CA Product & Manufacturer
+FC:            A ; APPLI/COM Functional Class
+EM:            FILE ; TDD Exchange Method
+SYNC:          No ; Not "sync" driven
+CODING:        I ; TDD Coding
+F_JOB_Q:       c:\applicom\job ; Job Queue
+F_ACK_Q:       c:\applicom\ack ; Acknowledge Queue (Response)
+ERROR_Q:       c:\applicom\err ; Error Queue (Response)
+TLX:           STD ; Telex (without dialogue facility) supported
+TX:            STD ; Telex via Teletex service supported
+TTX:           STD ; Teletex service & Type options
+TTX:           OPD ; Teletex service & Type options
+TTX:           CTL ; Teletex service & Type options
+TTX:           DTM ; Teletex service & Type options
+TTX:           EDI ; Teletex service & Type options
+FX3:           STD ; Telefax service group 3
+ADDKEYS:       LASTTIME ; Additive Keywords
+ADDKEYS:       SUBADDR ; Additive Keywords
+
+# ; Beginning of new configuration
+APPLICOM:      Product2 (c) by Company ABC ; CA Product & Manufacturer
+FC:            B ; APPLI/COM Functional Class
+EM:            primitive ; TDD Exchange Method
+ALARM:         yes ; Callback supported
+CODING:        I ; TDD Coding
+DRIVER:        applicom ; Driver provided
+FX3:           STD ; Fax G3 service & Type options
+FX3:           DTM ; Fax G3 service & Type options
+FX3:           BFT ; Fax G3 service & Type options
+SUBMIT:        CONVERT ; Supports the Conversion Submissions
+CONVCHK:       TIFF2 ; Conversions to/from TIFF2 can be asked
+CONVCHK:       PCX ; Conversions to/from PCX can be asked
+ADDKEYS:       LASTTIME ; Additive Keywords
+ADDKEYS:       SPEED ; Additive Keywords
+ADDKEYS:       COMMENT ; Additive Keywords
+...
+```
+
+FIGURE E.2/T.611
+
+### **Sample CA-Descriptors**
+
+## Annex F
+
+## Exchange Method of 1992 Version
+
+(This annex does not form an integral part of this Recommendation)
+
+This annex lists the Exchange Method Functions of the 1992 version of this Recommendation, which are superseded by the new, so called Basic Exchange Method Functions. Table F.1 below depicts this.
+
+TABLE F.1/T.611
+
+**Exchange Method Comparison**
+
+| Exchange Method Function<br>(1992) | Basic Exchange Method Functions<br>(this Recommendation) |
+|------------------------------------|----------------------------------------------------------|
+| Login ( )                          | ELogin ( )                                               |
+| PutTDD ( )                         | EPutTDD ( )                                              |
+| –                                  | EPutData ( )                                             |
+| PollTDD ( )                        | EPollTDD ( )                                             |
+| GetTDD ( )                         | EGetTDD ( )                                              |
+| –                                  | EGetData ( )                                             |
+| SetAlarm ( )                       | ESetAlarm ( )                                            |
+| –                                  | EAbortData ( )                                           |
+| Logout ( )                         | ELogout ( )                                              |
+
+### F.1 Exchange Method Functions of 1992 version
+
+#### F.1.1 Function Login
+
+The function Login shall be supported by the CA. It shall be invoked by the LA before any LA-CA interchange of Request TDDs and responses.
+
+##### F.1.1.1 Purpose
+
+The function Login returns to the LA a "Connection-ID" that will be used all along the LA-CA interaction until the LA logs out.
+
+The login function is the place where a CA may control access of an LA to it. This can be achieved by checking the Login-name and the Password given by the LA. However, to which extent control of the access rights is performed, is up to the CA implementation.
+
+##### F.1.1.2 Behaviour
+
+The CA checks the parameters of the Login call. If they match, it then generates a Connection-ID the LA shall use subsequently in PutTDD, PollTDD, GetTDD and Logout function calls. The LA shall wait for the return status to proceed: if the Connection-ID returned is set to Null (zero), it means the CA failed to connect the LA due to identification failures.
+
+##### F.1.1.3 Parameters
+
+The following parameters are required (see Table F.2).
+
+TABLE F.2/T.611
+
+##### **Parameters of the Login function**
+
+| Parameter Name | Structure | Comment                                                                                                                                                                                 | Direction        |
+|----------------|-----------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------|
+| Login-Name     | String    | States the name of the LA user, used to connect an LA to a CA (differs from the LA-ID)                                                                                                  | Input Parameter  |
+| Password       | String    | The LA gives its password so that the CA can identify the LA                                                                                                                            | Input Parameter  |
+| Connection-ID  | Integer   | Returned by the CA if the Login function succeeds. Otherwise (e.g. identification failed) the CA sets the value to NULL and the error code is given by the Status parameter (see below) | Output Parameter |
+| Status         | Integer   | Return error code (0000 means success)                                                                                                                                                  | Output Parameter |
+
+#### **F.1.2 Function PutTDD**
+
+The function PutTDD shall be supported by the CA. It may be invoked by an LA.
+
+##### **F.1.2.1 Purpose**
+
+The purpose of the PutTDD function is to transmit a Request TDD from an LA to a CA.
+
+##### **F.1.2.2 Behaviour**
+
+The CA copies the Request TDD carried by the PutTDD function into its internal structures. The result is composed of a status notified immediately to the requesting LA, and a REQ-ID reference.
+
+The TDD is then parsed by the CA which will further process it as required by the nature of the TDD.
+
+##### **F.1.2.3 Parameters**
+
+The following parameters are required (see Table F.3).
+
+TABLE F.3/T.611
+
+##### **Parameters of the PutTDD function**
+
+| Parameter Name | Structure      | Comment                                                                                                                                                                                   | Direction        |
+|----------------|----------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------|
+| Connection-ID  | Integer        | The connection identifier returned by the Login function                                                                                                                                  | Input Parameter  |
+| TDD location   | Memory address | Specifies where the LA's TDD is located so that the CA can copy it into its own internal structure. When the function is complete, the LA's TDD may be deleted or used for other purposes | Input Parameter  |
+| TDD size       | Integer        | Indicates the size of the TDD so that the CA can allocate enough internal resources to handle it                                                                                          | Input Parameter  |
+| Status         | Integer        | Acknowledges the PutTDD function. Return error code (0000 means success)                                                                                                                  | Output Parameter |
+
+#### F.1.3 Function PollTDD
+
+The PollTDD function asks the CA how many Response TDDs are waiting to be handled by the requesting LA. The PollTDD returns the number of Response TDDs waiting, and the type and size of the first Response TDD that will be returned by the next call to the GetTDD function.
+
+##### F.1.3.1 Purpose
+
+The purpose of the PollTDD function is to prepare the LA for the handling of a possible Response TDD coming from a CA. It also gives an indication of the number of Response TDDs that are waiting to be handled by the LA.
+
+##### F.1.3.2 Behaviour
+
+When the CA has many Response TDDs available, it chooses the one it will return first. This Response TDD is the TDD that will be transmitted to the LA at the next GetTDD function call emitted by the same LA.
+
+When no Response TDD is available for the requesting LA, the return status is set to the value zero, in which case the TDD size returned is set to zero. If the TDD that was submitted is erroneous or unknown, e.g. the <TDD Header> is missing, then the function returns the original Request TDD, and sets the return status to the value zero.
+
+When a Response TDD is available, the LA shall allocate an empty TDD which will hold the copy of the Response TDD still under CA control. Table F.4 below shows the various TDD types defined.
+
+TABLE F.4/T.611
+
+**Assignment of TDD types**
+
+| Number | TDD type                                                             | Number | TDD type          |
+|--------|----------------------------------------------------------------------|--------|-------------------|
+| 0      | Unknown or erroneous TDD was submitted, or no Response TDD available | 4      | SUBMIT Response   |
+| 1      | SEND Response                                                        | 5      | EXTEND Response   |
+| 2      | RECEIVE Response                                                     | 6      | NATIONAL Response |
+| 3      | TRACE group Response                                                 | 7      | PRIVATE Response  |
+
+##### F.1.3.3 Parameters
+
+The following parameters are required (see Table F.5).
+
+#### F.1.4 Function GetTDD
+
+The function GetTDD shall be supported by the CA. It may be invoked by an LA.
+
+##### F.1.4.1 Purpose
+
+The purpose of the GetTDD function is to retrieve a Response TDD from a CA. The CA copies the Response TDD into an internal structure of the LA.
+
+TABLE F.5/T.611
+
+##### **Parameters of the PollTDD function**
+
+| Parameter Name | Structure | Comment                                                                                                        | Direction        |
+|----------------|-----------|----------------------------------------------------------------------------------------------------------------|------------------|
+| Connection-ID  | Integer   | The connection identifier returned by the Login function                                                       | Input Parameter  |
+| TDD size       | Integer   | Indicates the size of the next Response TDD so that the LA can prepare enough resources to handle it           | Output Parameter |
+| TDD type       | Integer   | Indicates which type of TDD the LA shall receive next. See above for values                                    | Output Parameter |
+| TDD count      | Integer   | Indicates the number of Response TDDs that are waiting to be retrieved by the LA. NULL means no TDD is waiting | Output Parameter |
+| Status         | Integer   | Acknowledges the PollTDD function. Return error code (0000 means success)                                      | Output Parameter |
+
+##### **F.1.4.2 Behaviour**
+
+The LA indicates the location of an empty TDD where the CA shall copy a Response TDD that is available for the LA.
+
+The CA shall return to the LA the Response TDD that was qualified by the previous PollTDD function emitted by the same LA. The LA shall have prepared a recipient Response TDD area in its internal structures. The invocation of a GetTDD function by an LA shall always be preceded by a PollTDD function call.
+
+If the LA invokes two or more consecutive GetTDD functions (without an intermediate PollTDD function call) always the same TDD will be returned (the one indicated in the last PollTDD function return).
+
+##### **F.1.4.3 Parameters**
+
+The following parameters are required (see Table F.6).
+
+TABLE F.6/T.611
+
+##### **Parameters of the GetTDD function**
+
+| Parameter Name | Structure      | Comment                                                                                                                                                                           | Direction              |
+|----------------|----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------|
+| Connection-ID  | Integer        | The connection identifier returned by the Login function                                                                                                                          | Input Parameter        |
+| TDD location   | Memory address | Specifies where the CA can copy the Response TDD into the LA's internal structure. When the function is complete, the CA's Response TDD may be deleted or used for other purposes | Input/Output Parameter |
+| TDD size       | Integer        | Indicates the size of the empty TDD handed to the CA                                                                                                                              | Input Parameter        |
+| Status         | Integer        | Acknowledges the GetTDD function. Return error code (0000 means success)                                                                                                          | Output Parameter       |
+
+#### F.1.5 Function SetAlarm
+
+The function SetAlarm can optionally be supported by the CA. It can optionally be invoked by an LA. If the SetAlarm function is used by an LA, then that LA shall support the CallBackRoutine function. Support of the SetAlarm function is declared in the ICE.
+
+##### F.1.5.1 Purpose
+
+The purpose of the SetAlarm function is to declare to the CA the entry point of the CallBackRoutine function. The SetAlarm function indicates to the CA it can awake the LA by invoking the CallBackRoutine function. This function may be invoked only once during an LA/CA dialogue session.
+
+##### F.1.5.2 Behaviour
+
+The CA shall record the location of the CallBackRoutine function assigned by the LA. The CA can record as many CallBackRoutine locations as there are different logged-in LAs. The CA can then awake a particular LA by invoking its CallBackRoutine.
+
+##### F.1.5.3 Parameters
+
+The following parameters are required (see Table F.7).
+
+TABLE F.7/T.611
+
+**Parameters of the SetAlarm function**
+
+| Parameter Name           | Structure      | Comment                                                                    | Direction        |
+|--------------------------|----------------|----------------------------------------------------------------------------|------------------|
+| Connection-ID            | Integer        | The connection identifier returned by the Login function                   | Input Parameter  |
+| CallBackRoutine location | Memory address | Specifies the entry point of a particular LA CallBackRoutine function      | Input Parameter  |
+| Status                   | Integer        | Acknowledges the SetAlarm function. Return error code (0000 means success) | Output Parameter |
+
+#### F.1.6 Function CallBackRoutine
+
+The CallBackRoutine function can optionally be supported by the LA. It can optionally be invoked by a CA. In order to be invoked by the CA, the LA shall have declared it to the CA by means of the SetAlarm function.
+
+##### F.1.6.1 Purpose
+
+The CallBackRoutine function defines a mechanism that allows a CA to alert the LA that some Response TDDs are available. The use of this optional mechanism can improve the flow control between LAs and CAs on heavily loaded systems.
+
+Invocation of the CallBackRoutine by a CA does not guarantee that the LA will poll the CA within a certain delay. It only ensures that the LA will receive an alarm from a specific CA.
+
+The CA may invoke repeatedly the CallBackRoutine function of a given LA if that LA does not poll the CA quickly enough.
+
+There is only one CallBack Address allowed per LA. However, if an LA wishes to be called in dependency of a specific event, the LA has to implement this feature by itself within the back-called function.
+
+##### F.1.6.2 Behaviour
+
+The CallBackRoutine is designed to allow a logged-in CA to alert the LA that the CA needs to be polled via the PollTDD function. Thus the LA should poll the CA as soon as possible so that the CA does not enter an overflow error condition.
+
+##### F.1.6.3 Parameter
+
+The following parameter is required (see Table F.8).
+
+TABLE F.8/T.611
+
+**Parameters of the CallBackRoutine function**
+
+| Parameter Name | Structure | Comment                                                  | Direction       |
+|----------------|-----------|----------------------------------------------------------|-----------------|
+| Connection-ID  | Integer   | The connection identifier returned by the Login function | Input Parameter |
+
+#### F.1.7 Function Logout
+
+The function Logout shall be supported by the CA. It shall be invoked by the LA on completion of any LA-CA interchange of Request TDDs and responses.
+
+##### F.1.7.1 Purpose
+
+The function Logout returns to the LA a status that states whether the LA-CA interaction has finished orderly.
+
+##### F.1.7.2 Behaviour
+
+Before completing the LA-CA dialogue, the CA may (but is not obliged to) process all pending Request TDDs that were put out by that LA.
+
+##### F.1.7.3 Parameters
+
+The following parameters are required (see Table F.9).
+
+TABLE F.9/T.611
+
+**Parameters of the Logout function**
+
+| Parameter Name | Structure | Comment                                                                                                     | Direction        |
+|----------------|-----------|-------------------------------------------------------------------------------------------------------------|------------------|
+| Connection-ID  | Integer   | The connection identifier returned by the Login function                                                    | Input Parameter  |
+| Status         | Integer   | Returned by the CA. Indicates whether logout was orderly processed. Return error code (0000 means success). | Output Parameter |
+
+# Annex G
+
+## Service Specific Information
+
+(This annex does not form an integral part of this Recommendation)
+
+### G.1 Call Identification Line of the Telefax G4 and Teletex Service
+
+The Call Identification Line (CIL) as defined by ITU-T Recommendation F.200 and is laid out as indicated in Figure G.1.
+
+![](700f2fb63fbb87c933cd81ca42fb890f_img.jpg)
+
+|                           |   |                         |   |               |   |                          |
+|---------------------------|---|-------------------------|---|---------------|---|--------------------------|
+| Terminal ID<br>(Receiver) | / | Terminal ID<br>(Sender) | / | Date & Time   | / | Reference<br>Information |
+| 24 characters             |   | 24 characters           |   | 14 characters |   | 7 characters             |
+| 72 characters             |   |                         |   |               |   |                          |
+
+T0811890-93/d21
+
+FIGURE G.1/T.611
+
+Layout of the Call Identification Line; “/” is character code 2F<sub>HEX</sub>
+
+### G.2 Terminal ID
+
+The Terminal ID is defined for the Teletex service per ITU-T Recommendation F.200 and for the Telefax Group 4 service per ITU-T Recommendation F.184. It is laid out as shown in Figure G.2. DNIC stands for Data Network Identification Code.
+
+![](2a66bc0c9704a184ba82b62fee0c38eb_img.jpg)
+
+|                    |   |                          |                  |   |               |
+|--------------------|---|--------------------------|------------------|---|---------------|
+| DNIC               | — | Subscriber Access number | (=)<br>Extension | = | Mne-<br>monic |
+| max. 4             | 1 | max. 12 characters       | max. 4           | 1 | min. 3        |
+| max. 15 characters |   |                          |                  |   |               |
+| max. 24 characters |   |                          |                  |   |               |
+
+T0818090-94/d22
+
+FIGURE G.2/T.611
+
+Telefax G4 / Teletex Terminal ID
+
+# Annex H Summary of Transfer and Transmission Formats (This annex does not form an integral part of this Recommendation)
+
+### H.1 Transfer Formats related to Transmission Formats
+
+See Table H.1
+
+TABLE H.1/T.611  
+Summary of Transfer Formats
+
+| Service-id-parameter                                                                                                                                                                               | Type-id-parameter                           | Allowed Convert-id-parameter for           |                           |
+|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------|--------------------------------------------|---------------------------|
+|                                                                                                                                                                                                    |                                             | Outgoing documents                         | Incoming documents        |
+| FX3                                                                                                                                                                                                | STD                                         | ASCII, ASCIIxxx <sup>a)</sup> , T.50, TIFF | TIFF, TIFFx <sup>b)</sup> |
+|                                                                                                                                                                                                    | BTM, DTM, BFT, EDI                          | VOID                                       |                           |
+| FX4                                                                                                                                                                                                | STD                                         | ASCII, ASCIIxxx, T.50, TIFF                | TIFF, TIFFx               |
+|                                                                                                                                                                                                    | DTM, BFT, EDI                               | VOID                                       |                           |
+| TLX                                                                                                                                                                                                | STD                                         | ASCII, ASCIIxxx, T.50, T.61                |                           |
+| TX                                                                                                                                                                                                 | STD                                         | ASCII, ASCIIxxx, T.50, T.61                |                           |
+| TTX                                                                                                                                                                                                | STD                                         | ASCII, ASCIIxxx, T.50, T.61                |                           |
+|                                                                                                                                                                                                    | OPD, MD, CTL                                | ASCII, ASCIIxxx, T.50, T.61                |                           |
+|                                                                                                                                                                                                    | DTM, BFT, EDI                               | VOID                                       |                           |
+| EMAIL<br><br>5                                                                                                                                                                                     | STD                                         | T.50                                       |                           |
+|                                                                                                                                                                                                    | TELETEX                                     | ASCII, ASCIIxxx, T.50, T.61                |                           |
+|                                                                                                                                                                                                    | G3FAX, G4CLASS1                             | ASCII, ASCIIxxx, T.50, TIFF                | TIFFx                     |
+|                                                                                                                                                                                                    | VIDEOTEX, MESSAGE, BILATERAL, NATIONAL, ODA | VOID                                       |                           |
+| FT                                                                                                                                                                                                 | STD                                         | VOID                                       |                           |
+| <sup>a)</sup> "xxx" in "ASCIIxxx" stands for the code-page declared in the ICE (e.g. "ASCII437").<br><sup>b)</sup> "x" stands for the TIFF class to be read, which equals a value between 2 and 4. |                                             |                                            |                           |
+
+### H.2 Transmission Formats related to Service
+
+See Table H.2.
+
+TABLE H.2/T.611
+
+### **Summary of Transmission Formats (Document types)**
+
+| Service-id                                                                                                                                                                                                                                                                                                    | Type-id           | Means                                                                                                |
+|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------|------------------------------------------------------------------------------------------------------|
+| TLX                                                                                                                                                                                                                                                                                                           | STD               | Telex service (without dialogue facility)                                                            |
+| TX                                                                                                                                                                                                                                                                                                            | STD               | Telex via TELETEX Conversion Facility                                                                |
+| TTX                                                                                                                                                                                                                                                                                                           | STD <sup>a)</sup> | Basic TELETEX (T.61)                                                                                 |
+|                                                                                                                                                                                                                                                                                                               | OPD <sup>a)</sup> | Basic TELETEX (T.61): Operator Document                                                              |
+|                                                                                                                                                                                                                                                                                                               | MD <sup>a)</sup>  | Basic TELETEX (T.61): Monitor Document                                                               |
+|                                                                                                                                                                                                                                                                                                               | CTL <sup>a)</sup> | Basic TELETEX (T.61): Control Document                                                               |
+|                                                                                                                                                                                                                                                                                                               | DTM <sup>b)</sup> | Telematic File Transfer (TFT) of TELETEX Service: Document Transparent Mode                          |
+|                                                                                                                                                                                                                                                                                                               | BFT <sup>c)</sup> | Binary File Transfer of TELETEX Service                                                              |
+|                                                                                                                                                                                                                                                                                                               | EDI <sup>b)</sup> | Telematic File Transfer (TFT) of TELETEX Service: Edifact                                            |
+| FX3                                                                                                                                                                                                                                                                                                           | STD               | Basic Telefax G3 Service (MH)                                                                        |
+|                                                                                                                                                                                                                                                                                                               | BTM <sup>b)</sup> | Telematic File Transfer (TFT) of Telefax G3 Service: Basic Transparent Mode                          |
+|                                                                                                                                                                                                                                                                                                               | DTM <sup>b)</sup> | Telematic File Transfer (TFT) of Telefax G3 Service: Document Transparent Mode                       |
+|                                                                                                                                                                                                                                                                                                               | BFT <sup>d)</sup> | Binary File Transfer of Telefax G3 Service                                                           |
+|                                                                                                                                                                                                                                                                                                               | EDI <sup>b)</sup> | Telematic File Transfer (TFT) of Telefax G3 Service: Edifact                                         |
+| FX4                                                                                                                                                                                                                                                                                                           | STD               | Basic Telefax G4 Service (MR)                                                                        |
+|                                                                                                                                                                                                                                                                                                               | DTM <sup>b)</sup> | Telematic File Transfer (TFT) of Telefax G4 Service: Document Transparent Mode                       |
+|                                                                                                                                                                                                                                                                                                               | BFT <sup>c)</sup> | Binary File Transfer of Telefax G4 Service                                                           |
+|                                                                                                                                                                                                                                                                                                               | EDI <sup>b)</sup> | Telematic File Transfer (TFT) of Telefax G4 Service: Edifact                                         |
+| EMAIL                                                                                                                                                                                                                                                                                                         | STD               | IA5 Text body part                                                                                   |
+|                                                                                                                                                                                                                                                                                                               | TELETEX           | Teletex body part                                                                                    |
+|                                                                                                                                                                                                                                                                                                               | G3FAX             | Telefax Group 3 body part                                                                            |
+|                                                                                                                                                                                                                                                                                                               | G4CLASS1          | Telefax Group 4 body part                                                                            |
+|                                                                                                                                                                                                                                                                                                               | VIDEOTEX          | Videotex body part                                                                                   |
+|                                                                                                                                                                                                                                                                                                               | MESSAGE           | body part contains an IPM (consisting of heading and bodyparts) as transferred by the E-Mail system. |
+|                                                                                                                                                                                                                                                                                                               | BILATERAL         | Bilateral defined body part contents                                                                 |
+|                                                                                                                                                                                                                                                                                                               | NATIONAL          | National defined body part contents                                                                  |
+|                                                                                                                                                                                                                                                                                                               | ODA               | ODA body part                                                                                        |
+| FT                                                                                                                                                                                                                                                                                                            | STD               | Basic File Transfer                                                                                  |
+| <sup>a)</sup> Document type according to Annex E/T.62.<br><sup>b)</sup> Telematic File Transfer (TFT) according to Recommendation T.571.<br><sup>c)</sup> Binary File Transfer according to Recommendation T.434.<br><sup>d)</sup> Binary File Transfer according to Recommendation T.434 and T.30 (Annexes). |                   |                                                                                                      |
\ No newline at end of file
diff --git a/marked/T/T-REC-T.62bis-199303-I_PDF-E/raw.md b/marked/T/T-REC-T.62bis-199303-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..560c95f14162b5709a0f3a28543e2c2715135f5f
--- /dev/null
+++ b/marked/T/T-REC-T.62bis-199303-I_PDF-E/raw.md
@@ -0,0 +1,1415 @@
+
+
+![ITU logo: a globe with the letters ITU inside, and a lightning bolt symbol below it.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg)
+
+ITU logo: a globe with the letters ITU inside, and a lightning bolt symbol below it.
+
+INTERNATIONAL TELECOMMUNICATION UNION
+
+# ITU-T
+
+TELECOMMUNICATION  
+STANDARDIZATION SECTOR  
+OF ITU
+
+## **T.62*bis***
+
+(03/93)
+
+**TELEMATIC SERVICES  
+TERMINAL EQUIPMENTS AND PROTOCOLS  
+FOR TELEMATIC SERVICES**
+
+---
+
+**CONTROL PROCEDURES FOR TELETEX  
+AND G4 FACSIMILE SERVICES BASED  
+ON RECOMMENDATIONS X.215 AND X.225**
+
+**ITU-T Recommendation T.62*bis***
+
+(Previously "CCITT Recommendation")
+
+---
+
+# FOREWORD
+
+The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the International Telecommunication Union. The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis.
+
+The World Telecommunication Standardization Conference (WTSC), which meets every four years, established the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics.
+
+ITU-T Recommendation T.62 *bis* was revised by the ITU-T Study Group VIII (1988-1993) and was approved by the WTSC (Helsinki, March 1-12, 1993).
+
+# NOTES
+
+1 As a consequence of a reform process within the International Telecommunication Union (ITU), the CCITT ceased to exist as of 28 February 1993. In its place, the ITU Telecommunication Standardization Sector (ITU-T) was created as of 1 March 1993. Similarly, in this reform process, the CCIR and the IFRB have been replaced by the Radiocommunication Sector.
+
+In order not to delay publication of this Recommendation, no change has been made in the text to references containing the acronyms “CCITT, CCIR or IFRB” or their associated entities such as Plenary Assembly, Secretariat, etc. Future editions of this Recommendation will contain the proper terminology related to the new ITU structure.
+
+2 In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+# CONTENTS
+
+|                                                  |                                                                                 | <i>Page</i> |
+|--------------------------------------------------|---------------------------------------------------------------------------------|-------------|
+| 1                                                | Scope and field of application                                                  | 1           |
+| 2                                                | References                                                                      | 1           |
+| 3                                                | Actions for performing the control procedures for Teletex and Group 4 facsimile | 1           |
+| 3.1                                              | General                                                                         | 1           |
+| 3.2                                              | Session connection establishment phase                                          | 1           |
+| 3.3                                              | Session termination phase                                                       | 2           |
+| 3.4                                              | Document management                                                             | 2           |
+| 3.5                                              | Miscellaneous                                                                   | 5           |
+| 4                                                | Usage of the session service                                                    | 7           |
+| 4.1                                              | General                                                                         | 7           |
+| 4.2                                              | Session connection establishment                                                | 8           |
+| 4.3                                              | Session termination phase                                                       | 12          |
+| 4.4                                              | Data transfer phase                                                             | 13          |
+| 5                                                | Recommendations for implementing the session layer                              | 18          |
+| 5.1                                              | Additional parameters                                                           | 18          |
+| 5.2                                              | Implementation choices                                                          | 21          |
+| Annex A – Definitions                            |                                                                                 | 23          |
+| A.1                                              | General                                                                         | 23          |
+| A.2                                              | Session layer mode of communication                                             | 23          |
+| A.3                                              | Terms specific to document                                                      | 24          |
+| Annex B – State diagrams                         |                                                                                 | 24          |
+| Annex C – Types of documents                     |                                                                                 | 29          |
+| C.1                                              | General                                                                         | 29          |
+| C.2                                              | Normal document                                                                 | 29          |
+| C.3                                              | Operator document (optional)                                                    | 29          |
+| C.4                                              | Control document                                                                | 29          |
+| C.5                                              | Monitor document (optional)                                                     | 29          |
+| Annex D – Protocols for interactive applications |                                                                                 | 30          |
+
+# INTRODUCTION
+
+This Recommendation is related to other Recommendations.
+
+In particular it is related to certain Recommendations as defined by the Reference Model for Open Systems Interconnection (see Recommendation X.200).
+
+This Recommendation is based on the description of the session service (see Recommendation X.215) and the session protocol (see Recommendation X.225) as shown in Figure 1.
+
+![Diagram showing the relationship between X.215, T.62 bis, and X.225 (1) as equivalent to T.62.](d62e2e2281009c16f4ee61660e716cd9_img.jpg)
+
+```
+
+    X.215 ----> [ T.62 bis  ] }
+                [ X.225 (1) ] } Equivalent to T.62
+  
+```
+
+T0817530-94/d01
+
+Diagram showing the relationship between X.215, T.62 bis, and X.225 (1) as equivalent to T.62.
+
+FIGURE 1/T.62 *bis*
+
+For this Recommendation, Version 1 of the session protocol is used. This implies several types of restrictions, for example on the length of the user data fields. These restrictions are fully described for the protocol in Annex D/X.225 and they must be applied in the same way at the service.
+
+# NOTES
+
+- 1 Only the services and protocol elements relevant to Recommendation T.62 procedures are used (see Table 1).
+- 2 The session protocol described in Recommendation X.225 is based on the services provided by the transport layer as described in Recommendations X.214 and X.224.
+
+For compatibility with Teletex and Group 4 facsimile, additional rules (in accordance with Recommendation T.70, clause 5, including Annexes A and B) must be applied when using the transport service and protocol (see Recommendations X.214 and X.224, class 0).
+
+The control procedure for Teletex and Group 4 facsimile are currently described in Recommendation T.62.
+
+Recommendation T.62 may be superseded by this Recommendation and the appropriate session layer service and protocol described in the Recommendations X.215 and X.225.
+
+When using either Recommendation T.62 *bis* (based on the X-Series Recommendations) or Recommendation T.62 (based on Recommendation T.70) it is intended that the externally visible protocols are equal.
+
+It is the intention that Recommendations X.215 and X.225 together with this Recommendation do have the same level of detail and accuracy as Recommendation T.62 already has. However, for the time being Recommendation T.62 will be kept and in cases of discrepancy and/or incompatibility, Recommendation T.62 will take precedence over Recommendations X.215 and X.225 together with the application rules described in this Recommendation.
+
+This Recommendation covers all of Recommendation T.62 including the annexes.
+
+# CONTROL PROCEDURES FOR TELETEX AND G4 FACSIMILE SERVICES BASED ON RECOMMENDATIONS X.215 AND X.225
+
+*(Melbourne, 1988; amended at Helsinki, 1993)*
+
+# 1 Scope and field of application
+
+This Recommendation defines:
+
+- 1) A set of rules for using the OSI Session Service.
+- 2) The additional requirements for the implementation to conform to the control procedures for Teletex and Group 4 facsimile services.
+
+The set of rules consists of:
+
+- The actions to be taken by the session user for performing the control procedures.
+- The description of the use of the session service primitives and their parameters.
+- The encoding of parameters not covered by the session layer (for these parameters see also 5.2). These parameters are described as additional parameters for each primitive and each SPDU where appropriate. The length and value of these parameters are provided by the SS-user and no checking is made by the session layer itself.
+
+# 2 References
+
+Recommendations F.161, F.200, X.215, X.225, T.563, T.503, T.521, T.6, T.35, T.60, T.61, T.62, T.400-Series, T.390 and X.200.
+
+# 3 Actions for performing the control procedures for Teletex and Group 4 facsimile
+
+This clause describes the Teletex application protocol in terms of actions involving the session service primitives.
+
+## 3.1 General
+
+The control procedures for Teletex and Group 4 facsimile are designed to allow data to be transferred and managed between terminals in the form of documents. The present Recommendation only provides for the transfer of documents. As a consequence, no transfer of data can take place outside a document.
+
+- A *document* is composed of one or more *pages*.
+- Pages are sent sequentially and each page has to be individually *acknowledged*. However, several pages may be sent without waiting for the acknowledgement and the number of pages which can be sent in this manner is called the *window-size*.
+- The transfer of a document is executed from the *source* to the *sink* (see 3.2.3 and 3.4). For the purpose of the description, in the remainder of the text, the source is also called the *sender* and the sink is also called the *receiver*.
+
+## 3.2 Session connection establishment phase
+
+**3.2.1** The calling SS-user initiates the connection by issuing the S-CONNECT request primitive.
+
+The called SS-user may accept or refuse the connection by issuing the S-CONNECT response primitive.
+
+It is the responsibility of the initiator of the connection to examine the parameters sent by the remote terminal at session initiation and to determine whether the session should continue. If it is not to be continued, the session shall be ended normally.
+
+**3.2.2** A session connection is identified by means of:
+
+- a) the basic session reference (mandatory parameter) composed of:
+  - terminal identifier of the called terminal;
+  - terminal identifier of the calling terminal;
+  - date and time;
+- b) an optional additional session reference number, to uniquely identify the session connection.
+
+**3.2.3** At session connection establishment, the data, minor synchronize and major/activity tokens shall be available and assigned to the initiator side. Thus at session initiation the initiator is defined as being the current source of text information and is therefore the source terminal.
+
+**3.2.4** When accepting the connection the called SS-user may request the session control by issuing the primitive S-TOKEN-PLEASE request.
+
+In continuing the session, neither terminal is permitted to use any procedure or to send any information that does not comply with the receiving capabilities indicated by the session partner in the service identifier and non-basic session and terminal capabilities parameters of the S-CONNECT primitives at session initiation and/or by the parameters of S-CAPABILITY-DATA primitives.
+
+**3.2.5** The following rules shall apply to the private use and presently not defined parameters:
+
+- a) The use of these parameters in other primitives than S-CONNECT and S-CAPABILITY-DATA must be negotiated upon in advance by S-CONNECT or S-CAPABILITY-DATA. Presence of these parameters unexpectedly in other primitives may result in procedural errors.
+- b) The absence of a parameter of this kind in a response to S-CONNECT or S-CAPABILITY-DATA must be interpreted as an indication that the terminal is not capable of handling any of these functions.
+
+## **3.3 Session termination phase**
+
+The session connection is terminated by means of the S-RELEASE services for normal (or error-free) termination.
+
+The S-U-ABORT/S-P-ABORT services may be used at any time by either terminal to terminate a session, whenever a condition is detected indicating that the session cannot be continued successfully. S-U-ABORT/S-P-ABORT shall only be used when there is no other suitable way of ending the session.
+
+In the two-way alternate or one way communication mode, only the sender of the S-CONNECT request may send the S-RELEASE request when he is the current source.
+
+NOTE – The transport connection may be reused as a local implementation choice and this may depend on an application decision which may be passed across the session service interface.
+
+## **3.4 Document management**
+
+The document concept, as defined in Recommendation T.62, is mapped onto the activity concept of the session protocol. Consequently, the document number corresponds to the activity identifier. The transfer of a document is delimited by a start and an end.
+
+A document is sent by the source (sender) to the sink (receiver) and this transfer may only take place when the source owns all the available tokens.
+
+When the sink wants to send a document it may express this requirement by issuing an S-TOKEN-PLEASE primitive. When the transfer of a document is terminated, the sender may give the control to the receiver by issuing an S-CONTROL-GIVE primitive. But there is no requirement for sending text information prior to issuing an S-CONTROL-GIVE primitive. When the protocol element exchange corresponding to this primitive is executed, all the tokens are assigned to the receiver; consequently it becomes the source (or sender) and the former source becomes the sink (or receiver). A document transfer may then be started from the new source to the new sink.
+
+### 3.4.1 Start of document
+
+The S-ACTIVITY-START service indicates the start of a document. It also indicates the start of the first page.
+
+### 3.4.2 Page boundaries
+
+**3.4.2.1** The S-SYNC-MINOR service indicates the boundary between pages. It also indicates a checkpoint for error recovery purposes and invites the sink to accept responsibility for the previously received page. In the basic services a checkpoint must be inserted at each page boundary using S-MINOR-SYNC request. Each checkpoint must be explicitly acknowledged in the right sequence, by using S-SYNC-MINOR response. Consequently the checkpoint reference number corresponds to the minor synchronization point serial number.
+
+The S-SYNC-MINOR response shall be used to indicate that the receiver accepts responsibility for that page. If the receiver does not accept the responsibility for the page he shall use the S-U-EXCEPTION-REPORT service. In this case the transmission must be interrupted by the sender using the S-ACTIVITY-INTERRUPT or DISCARD services.
+
+The receiver may reject reception for a detected error, but he is not obliged to check the document for errors. Once a page has been positively acknowledged, any error recovery for the subsequent detection of an error is beyond the scope of these control procedures.
+
+**3.4.2.2** When a source terminal receives an S-SYNC-MINOR confirmation with the receiving ability jeopardized (RAJ) parameter set to 1 (see 4.4.6) during a document transmission, it may continue to transmit one or more pages until the window is closed. In this context the following rules apply:
+
+- a) if the source subsequently receives an S-SYNC-MINOR confirmation with the RAJ parameter set to 0 (see 4.4.6), it will be able to continue transmission;
+- b) if the source subsequently receives an S-U-EXCEPTION-REPORT with a parameter value “SS-user receiving ability jeopardized” (indicating “memory overflow”), the document transmission should be terminated abnormally. The source shall issue either an S-ACTIVITY-DISCARD request or an S-ACTIVITY-INTERRUPT request.
+
+**3.4.2.3** When a sink terminal sends an S-SYNC-MINOR response with the receiving ability jeopardized parameter set to 1, and subsequent memory overflow results in sending S-U-EXCEPTION-REPORT, the value of the reason code will be “SS-user receiving ability jeopardized” (indicating “unable to continue the session”).
+
+### 3.4.3 End of document
+
+**3.4.3.1** The S-ACTIVITY-END service shall be used to indicate the end of a document. It also indicates the end of the final page and as such represents the final checkpoint. The S-ACTIVITY-END response gives a positive acknowledgement to the last checkpoint. In the basic services this is the last page reference number.
+
+When confirming this service, the receiver shall indicate that:
+
+- a) he has not detected an error;
+- b) he accepts responsibility for the received document;
+- c) he is ready to receive a new S-ACTIVITY-START or S-ACTIVITY-RESUME request.
+
+To refuse the checkpoint indicated in S-ACTIVITY-END indication, the SS-user shall use the S-U-EXCEPTION-REPORT service.
+
+**3.4.3.2** Only if the sink terminal has sent an S-ACTIVITY-END response and received a valid S-ACTIVITY-START, S-ACTIVITY-RESUME, S-ACTIVITY-DATA, S-DISCONNECT or S-CONTROL-GIVE indication, it is certain that the source terminal will not use error recovery procedures regarding the preceding document. In all other cases it can happen that after sending an S-ACTIVITY-END response a repetition of pages takes place and the duplications may be deleted by the sink terminal.
+
+### 3.4.4 Interruption of a document
+
+Documents may be interrupted or discarded by using the S-ACTIVITY-INTERRUPT or S-ACTIVITY-DISCARD services.
+
+**3.4.4.1** The S-ACTIVITY-INTERRUPT service shall be used to indicate the abnormal ending of a document but the part of the document received so far should not be discarded. When the receiver of a document sends an S-ACTIVITY-INTERRUPT response, this means that he has already accepted the responsibility for the received document (up to the last checkpoint for which a positive acknowledgement has been sent). It does not indicate that he will be able to perform the linking of the following parts of the interrupted document.
+
+**3.4.4.2** The S-ACTIVITY-DISCARD service shall be used to indicate the abnormal ending of a document and that the receiver of the document is not held responsible for the part of the document received so far. Therefore, as a local function outside these control procedures, the receiver can delete the part of the text received.
+
+###### NOTES
+
+1 The S-ACTIVITY-DISCARD service is an invitation to discard the whole of the document and not merely the part of the document transmitted since the last S-ACTIVITY-RESUME.
+
+2 The receiving terminal may discard the document from its memory (but has no obligation to do so) and/or indicate to the operator that this part of the document has no value. If the text is not deleted, the operator shall be informed.
+
+3 The use of the S-ACTIVITY-DISCARD service for Group 4 facsimile is for further study.
+
+**3.4.4.3** There are two ways that the sender is permitted to recover from an interrupted transmission:
+
+- a) a cancellation is achieved by the subsequent use of the S-ACTIVITY-RESUME and S-ACTIVITY-DISCARD services and the transmission will be resumed by the S-ACTIVITY-START service;
+- b) the sender may resume by use of the S-ACTIVITY-RESUME service, starting at that point in the document corresponding to the last checkpoint for which an acknowledgement was received.
+
+**3.4.4.4** If, during document transmission, an abnormal condition occurs, with the exception of the one described in 3.4.4.5, the following rules apply:
+
+- a) In the case that a document transmission was initiated by S-ACTIVITY-START request and no minor synchronization point has been positively acknowledged, either the S-ACTIVITY-DISCARD or INTERRUPT service should be used. If the S-ACTIVITY-INTERRUPT service is used it should be interpreted as an S-ACTIVITY-DISCARD. In this case, however, it is necessary to reply with an S-ACTIVITY-INTERRUPT response to the S-ACTIVITY-INTERRUPT indication as required by the session service definition. It is only a matter of different semantic interpretation of the service by the session service user.
+- b) In all other cases S-ACTIVITY-INTERRUPT or DISCARD service should be used.
+
+**3.4.4.5** The following rules apply if the session is aborted during document transmission:
+
+- a) If document transmission was initiated by S-ACTIVITY-START request and no minor synchronization point has been positively acknowledged during that transmission, both sending and receiving entities shall treat the failure as if the S-ACTIVITY-DISCARD service had been correctly initiated and completed.
+- b) In other cases, both sending and receiving entities shall treat the failure as if the S-ACTIVITY-INTERRUPT service had been correctly initiated and completed.
+
+### **3.4.5 Resumption of a document**
+
+The S-ACTIVITY-RESUME service indicates the continuation of a document that has previously been partially transmitted.
+
+The linking of the parts of an interrupted document is a local operation at the receiver and is therefore not within the responsibility of the control procedures. Thus these procedures cannot guarantee that this linking of parts of a document will be effected.
+
+###### NOTES
+
+1 The checkpoint reference number appearing in the primitive S-ACTIVITY-RESUME is the last checkpoint reference number for which a positive acknowledgement has been received. It should be noted that positive acknowledgement may have been sent by the sink terminal but not received by the source terminal.
+
+2 If several continuations are required to complete transmission of a document, they are all linked to the partial transmission in which the activity start service was used. The sequence of checkpoint reference numbers is then used to identify the correct sequencing of parts to be linked, this sequence and all such continuations must be transmitted in this order.
+
+3 It is the responsibility of the receiver to discard any text information that has been duplicated in the process of continuation of an interrupted transmission.
+
+### **3.4.6 Exchange of terminal capabilities**
+
+Outside document transfer (outside activities) the S-CAPABILITY-DATA service may be used to exchange information to enable a check of the terminal capabilities (both standardized and private use) and to investigate the storage capability of the remote terminal.
+
+The primitive shall include a parameter with a list of receiving capabilities that may be needed at the receiver by the sender of this primitive.
+
+Storage that has been reserved by the S-CAPABILITY-DATA service can be released after session termination or when a new S-CAPABILITY-DATA indication with storage requirement indication is received.
+
+### **3.4.7 Exception conditions**
+
+**3.4.7.1** Detection of a protocol error may cause the SS-provider to issue an S-P-EXCEPTION-REPORT indication. On receipt of an S-P-EXCEPTION-REPORT indication, the SS-user shall use the S-ACTIVITY-INTERRUPT or S-ACTIVITY-DISCARD service (subject to the tokens restrictions); it may also use the S-U-ABORT service.
+
+**3.4.7.2** The receiver of a document may issue an S-U-EXCEPTION-REPORT request at any time after having received an S-ACTIVITY-START or S-ACTIVITY-RESUME indication. It may issue an S-U-EXCEPTION-REPORT request after having received an S-SYNC-MINOR indication, or an S-ACTIVITY-END indication instead of giving the confirmation.
+
+When receiving an S-U-EXCEPTION-REPORT indication, the SS-user shall use either the S-ACTIVITY-INTERRUPT or S-ACTIVITY-DISCARD service; it may also use the S-U-ABORT service.
+
+## **3.5 Miscellaneous**
+
+### **3.5.1 Acknowledgement window**
+
+**3.5.1.1** The window mechanism has been introduced in order to allow continuous transmission of pages. It may also be used by the receiving terminal to resolve local time problems without affecting the continuous transmission.
+
+NOTE – For efficiency reasons, the receiving terminal will transmit the response to acknowledge outstanding checkpoing(s) as soon as possible.
+
+The design of the terminal should be such that continuous reception is possible in normal operation of the terminal (e.g. with an average Teletex page content of 1600 octets). The use of the window mechanism should take into account the quality of service requirements in Recommendations F.200 and F.161.
+
+In the basic Teletex service, the sender is prohibited from exceeding an acknowledgement window size of three. The maximum window size may be negotiated during session establishment.
+
+**3.5.1.2** The following rules should apply to the use of window size:
+
+- a) The indication of the window size parameter is not mandatory for the Teletex service, but is mandatory for the Group 4 facsimile service (in the S-CONNECT request and response). It may have a value in the range of 1 to 255. The absence of this parameter in S-CONNECT request or response must be interpreted as the default value of three for the Teletex service.
+- b) All Teletex terminals should support a window size of 3. Group 4 facsimile terminals of Classes 2 and 3 should be able to support a window size of 3 when interworking with Teletex. Enhanced Teletex terminals (e.g. with mixed-mode capability) and all Group 4 facsimile terminals may require other window sizes.
+- c) The source terminal is free to use any window size that does not exceed the window size indicated by the sink terminal (in S-CONNECT request or response).
+- d) If the sender of S-CONNECT request or response is a basic Teletex terminal which does not indicate any parameter for the window size, the receiver should be aware that the sender may ignore any window size indicated and use the window size of 3.
+
+### 3.5.2 Negotiation of optional capabilities
+
+Two methods are provided. The first is used at session initiation to exchange a limited list of capabilities (S-CONNECT service). The second method may be used when required, after session initiation, to indicate the sender's requirements for extended capabilities (S-CAPABILITY-DATA, S-ACTIVITY-START, S-ACTIVITY-RESUME services).
+
+### 3.5.3 Negotiation of storage requirements
+
+Storage availability can be indicated in the following ways:
+
+- a) When a Teletex session is established, it is implicitly assumed that there is adequate receive memory for the call. Exceptionally a receiver memory overflow will occur. The continued sending of the document from the source will be stopped by the sink. The sink shall indicate the reason for stopping the transmission.
+- b) When a Group 4 facsimile session is established, it can only be assumed that the called terminal has adequate recording paper to print at least one page of information (for basic Class 1 apparatus). Negotiation of storage requirements is mandatory for Group 4 Classes 2 and 3 facsimile apparatus. Having negotiated this requirement, exceptionally, a receive memory overflow may occur. The continued sending of the document from the source will be stopped by the sink. The sink shall indicate the reason for stopping the transmission.
+- c) The provision is also made in the procedure for a mandatory indication that the ability of the receiving terminal to continue to accept traffic is jeopardized.
+- d) The S-CAPABILITY-DATA service also provides the possibility to investigate the storage availability at the receiving terminal prior to the transmission of a document.
+
+### 3.5.4 Timer handling
+
+The timer handling is based on the occurrence of certain events. These events may be protocol elements or service primitives and it is assumed that there is no time delay between the occurrence of a session service primitive and the related protocol element and vice versa.
+
+Two types of timer are defined:
+
+- inactivity timer;
+- demand-response timer.
+
+### 3.5.5 Inactivity timer
+
+**3.5.5.1** During the lifetime of a session connection, the sink terminal is responsible for the detection of any period of inactivity in excess of the inactivity timer value (indicating for example a failure or another inability to continue productive use of the session). The inactivity timer value may be negotiated. The default value is 60 seconds.
+
+**3.5.5.2** The inactivity timer is used by the sink terminal to detect any period during which no protocol element is exchanged. Such period must be detected whenever the transport connection exists.
+
+This timer is started or restarted on reception or sending of each event by the sink terminal when further action is expected from the source terminal.
+
+This timer is stopped on reception of an event by the sink terminal when no further action is expected from the source terminal.
+
+When the timer expires, the S-ABORT service shall be used.
+
+Further information can also be found in Figure B.1.
+
+**3.5.5.3** The following rules apply to the negotiation of the value of the inactivity timer:
+
+- a) An inactivity timer value different from 60 seconds will apply only if this parameter is indicated by both terminals, i.e. negotiation, at session establishment (via S-CONNECT) or document boundaries (via S-CAPABILITY-DATA).
+- b) If both terminals indicate an inactivity timer value, the following rules apply for the duration of the session or until a subsequent negotiation has taken place:
+  - i) the smaller of the two values applies when both values are greater than or equal to 60 seconds;
+
+- ii) the larger of the two values applies when both values are less than 60 seconds.
+- iii) a timer value of 60 seconds applies if one value is above and one is below 60 seconds.
+
+### **3.5.6 Demand response timer**
+
+#### **3.5.6.1** The demand/response timer is managed by the source terminal
+
+This timer is responsible for detection of any period of time during which the sink terminal has failed to send a response/acknowledgement. The value of that timer is 60 seconds. Negotiation of the demand response timer value is for further study.
+
+**3.5.6.2** In general, this timer has to be started by the source terminal for each event towards the sink terminal for which a response/acknowledgement is expected.
+
+It is stopped when a response is received. When the timer expires, the S-ABORT service shall be used.
+
+#### **3.5.6.3** In the following special cases, specific actions are required:
+
+- on the occurrence of an abort primitive/SPDU (sent or received), the demand response timer is stopped if it has been started;
+- reception of an exception-report indication (or associated SPDU) shall be considered as the response to the primitive (SPDU) sent previously. Consequently the associated action is to stop the timer.
+
+Further information can also be found in Figures B.1 and B.2.
+
+### **3.5.7 Document reference number**
+
+Document reference numbers (DRNs) shall be assigned as decimal digits, preferably, but not necessarily, starting from 001. DRNs shall then sequentially be incremented by one for each successive document. DRNs shall be assigned to all documents in a session, irrespective of the document type identifier or whether S-ACTIVITY-START or S-ACTIVITY-RESUME is used as the initiating primitive. The number does not necessarily have to comprise 3 digits and leading zeros do not necessarily have to be transmitted. In all cases the leading zeros must be ignored.
+
+NOTE – In order to uniquely identify the documents exchanged, it is recommended that the same DRNs should not appear within a session. However, it is noted that some existing terminals may cause duplication of DRNs when documents are exchanged in both directions.
+
+# **4 Usage of the session service**
+
+See Recommendation X.215.
+
+## **4.1 General**
+
+The rules given hereinafter indicate how the session service must be used by the higher layer entity.
+
+It is assumed that where a parameter is non-mandatory in the protocol, it is also non-mandatory in the corresponding primitive. When a default value applies in the protocol, the same default value applies at the service interface.
+
+The services which are used are indicated in Table 1 with the corresponding functional units.
+
+The data, synchronization minor and major/activity tokens must be available. The release token is not available.
+
+The term “additional parameter” as used in this Recommendation applies to parameters which are not included in the session service described by Recommendation X.215 but which are nevertheless essential to describe interaction between the session service user and the session layer itself, when it is to be used in a form compatible with control procedures for Teletex and Group 4 facsimile (consequently they have to be taken into account when implementing the session layer for such use). These parameters contain information carried by the session protocol elements independently of the “user data” parameter contained in the session protocol elements which are described in clause 3 of this Recommendation.
+
+TABLE 1/T.62 *bis*
+
+| Functional units         | Service primitives                                                                                                      |
+|--------------------------|-------------------------------------------------------------------------------------------------------------------------|
+| Kernel                   | S-CONNECT<br>S-RELEASE<br>S-U-ABORT<br>S-P-ABORT<br>S-DATA                                                              |
+| Half duplex              | S-TOKEN-PLEASE                                                                                                          |
+| Minor synchronisation    | S-SYNC-MINOR                                                                                                            |
+| Activity management      | S-ACTIVITY-START<br>S-ACTIVITY-RESUME<br>S-ACTIVITY-INTERRUPT<br>S-ACTIVITY-DISCARD<br>S-ACTIVITY-END<br>S-CONTROL-GIVE |
+| Capability data exchange | S-CAPABILITY-DATA                                                                                                       |
+| Exceptions               | S-P-EXCEPTION-REPORT<br>S-U-EXCEPTION-REPORT                                                                            |
+
+## **4.2 Session connection establishment**
+
+The following service primitive is used:
+
+- S-CONNECT.
+
+### **4.2.1 The parameters of the S-CONNECT are used as follows**
+
+#### **4.2.1.1 Session connection identifier**
+
+- a) The calling SS-user reference shall only contain the calling terminal identifier. This mandatory parameter (request and indication primitives) identifies the calling terminal. This is a sequence of graphic characters as defined in Recommendation F.200.
+- b) The called SS-user reference shall only contain the called terminal identifier. This mandatory parameter (response and confirm primitives) provides the terminal identification of the sender of the S-CONNECT response primitive. This is a sequence of graphic characters as defined in Recommendation F.200.
+- c) The common reference shall only contain the date and time. This parameter is both mandatory and identical on all primitives. It gives the date and time and it is a sequence of graphic characters as defined in Recommendation F.200. It is used in conjunction with the terminal identifications of both terminals in a session as a reference to that session.
+- d) The additional reference information shall only contain the additional session reference number. If it is used by the initiator and by the responder, it shall have the same value in the response as in the request. If it is not used by the initiator it shall not be included in the request. If it is not used by the responder it shall not be included in the response. This number shall be used in addition to the basic session reference (calling and called terminal identifiers, date and time) when this basic session reference is not sufficient to uniquely identify the session and such unique identification is required. In this case it shall also be used together with the basic session reference, when referring to this session in an S-ACTIVITY-RESUME primitive. The reference number is a fixed length of two decimal digits as coded in Recommendation T.61.
+
+#### 4.2.1.2 Calling and called SSAP addresses
+
+The session layer addressing is not used in Teletex and Group 4 facsimile services (these parameters are not used).
+
+#### 4.2.1.3 Quality of service
+
+This parameter must be set so as not to use expedited data (transport expedited is not available in Teletex) and in such a way that extended concatenation is not selected.
+
+#### 4.2.1.4 Session requirements
+
+This parameter may be omitted and in this case the default value applies. The following functional units shall be selected:
+
+- minor synchronization;
+- activity management;
+- capability data exchange;
+- half-duplex;
+- exceptions.
+
+#### 4.2.1.5 Initial synchronization point serial number
+
+This parameter is not used in Teletex and Group 4 facsimile services.
+
+#### 4.2.1.6 Initial assignment of tokens
+
+This parameter may be omitted and in that case, the default value applies. All available tokens are assigned to the calling entity.
+
+#### 4.2.1.7 Result (only in response and confirmation)
+
+This parameter is used to accept or refuse the session connection. In case of refusal, this parameter may also convey up to 69 characters. Only characters convertible one-to-one to the telex alphabet (ITA2) shall be allowed and Teletex code shall be used.
+
+#### 4.2.1.8 User data
+
+This non-mandatory parameter is used to convey data of the presentation and/or application protocol(s). All information necessary to negotiate the document interchange protocol parameters defined in the T.400-Series Recommendations is contained in this parameter field.
+
+### 4.2.2 Additional parameters
+
+The following parameters may also be included:
+
+#### 4.2.2.1 Non-basic session capabilities
+
+If used, this non-mandatory parameter indicates which non-basic session capabilities are available as receiving capabilities of the sender of this primitive (see Table 2).
+
+TABLE 2/T.62 *bis*
+
+| Parameter                          |    | Function                                    | Encoding<br>(subclause) |
+|------------------------------------|----|---------------------------------------------|-------------------------|
+| Miscellaneous session capabilities | nm | Session suspension<br>Interactive operation | 4.2.3.1                 |
+| Window size                        | nm | Negotiation of window size                  | 4.2.3.2                 |
+
+#### 4.2.2.2 Service identifier
+
+This mandatory parameter indicates whether the sender of this primitive intends to use the Telematic services.
+
+##### NOTES
+
+- 1 For the basic Teletex services, the service identifiers in the S-CONNECT request and response must be identical.
+- 2 In case of interconnections between the terminals of different services, the service identifiers in the S-CONNECT request and response may not be identical.
+
+#### 4.2.2.3 Inactivity timer
+
+This non-mandatory parameter is used to negotiate the value of the inactivity timer.
+
+#### 4.2.2.4 Non-basic terminal capabilities
+
+These parameters indicate which of the non-basic capabilities listed in Table 3 for the Teletex service, are available as receiving capabilities of the sender of this request. These parameters are mandatory if the equipment is capable of any of the specific functions listed in Table 3. Absence of the parameter indicates that the specific function is not available.
+
+NOTE – The definitions of these presentation capabilities may be found in Recommendation T.60. Future extensions and private-use capabilities are to be accommodated with the capability data exchange service.
+
+TABLE 3/T.62 *bis*
+
+| Parameter                           |    | Function                                                                                                                                                                                                                                                                       | Encoding (subclause) |
+|-------------------------------------|----|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------|
+| Control character sets              | nm | Reverse line feed                                                                                                                                                                                                                                                              | 4.2.3.5              |
+| Page formats                        | nm | ISO A4 vertical and horizontal orientation                                                                                                                                                                                                                                     | 4.2.3.7              |
+| Miscellaneous terminal capabilities | nm | Character spacing of 2.12 mm<br>(12 characters per 25.4 mm)<br>Character spacing of 1.69 mm<br>(15 characters per 25.4 mm)<br>Line feed parameter value of one spacing<br>of 3.175 mm<br>Line feed parameter value of one spacing<br>of 0.5, 1.0, 1.5 and two spacings of 5 mm | 4.2.3.8              |
+
+#### 4.2.2.5 Private use parameters
+
+These parameters are not mandatory. Their definition and use are not standardized (see 3.2).
+
+#### 4.2.2.6 Non-standardized capabilities
+
+This non-mandatory parameter is used to ascertain compatibility regarding the use of non-standardized terminal capabilities.
+
+### 4.2.3 Encoding of the S-CONNECT additional parameters value
+
+#### 4.2.3.1 Miscellaneous session capabilities
+
+This PV field shall indicate possible modes of operation. The encoding of the first octet shall be:
+
+- a) bit 1: reserved
+- b) bit 2: reserved (for session suspension)
+- c) bit 3 set to 1 indicates the terminal capability for interactive operation (data transfer outside activity boundaries).
+
+All other bits are reserved for future standardization.
+
+#### 4.2.3.2 Window size
+
+A binary number of fixed length of one octet, with a minimum value of one and a maximum value of 255 in decimal (i.e. a binary value of 11111111). The default value is three in decimal (i.e. a binary value of 00000011).
+
+#### 4.2.3.3 Service identifier
+
+The coding for the service identifier is as follows:
+
+|      |          |           |
+|------|----------|-----------|
+| Bits | 87654321 | Service   |
+|      | 00000001 | Telematic |
+
+All other encodings are for further study.
+
+#### 4.2.3.4 Inactivity timer
+
+- a) Bits 8 and 7 indicate the unit of inactivity timer value and bits 6 to 1 indicate the binary value in the range of 1 to 63.
+
+Bits 87 Unit of timer
+
+- 00 Second(s);
+- 01 Minute(s);
+- 10 Hour(s);
+- 11 Reserved for extension.
+
+- b) All bits of the first octet set to zero indicates the inactivity timer value is of infinity, i.e. the timer is disabled.
+
+#### 4.2.3.5 Control character sets
+
+Refer to Recommendations T.60 and T.61.
+
+A variable length field indicating the receiving capability for non-basic standardized control character sets. Each such control character set shall be indicated by the sequence of characters used to designate that set, as defined in Recommendation T.61. Where more than one such character set are to be indicated, the ESC character fulfills the purpose of a separator between the character set indicators.
+
+#### 4.2.3.6 Non-standardized capabilities
+
+The first octet represents the registered CCITT country code as specified in Recommendation T.35 to be used to identify non-standard capabilities. Additional octets may be specified by each country Administration.
+
+#### 4.2.3.7 Teletex page formats
+
+Refer to Recommendations T.60 and T.61.
+
+The value of the first octet of the parameter value will indicate the capability of a page format, as defined in Table 4. If the terminal is capable of more than one format, these will be indicated in the first and subsequent octets, one octet per value (see Note 1 of Table 4). No separator between the values will be given. The length indicator of the parameter will indicate if more than one value is given. All parameter values shall be inserted in increasing order of their binary values.
+
+#### 4.2.3.8 Miscellaneous terminal capabilities
+
+A variable length field indicating the receiving capabilities for non-basic standardized values of character spacing, line spacing and graphic renditions. Each parameter value of such a function shall be indicated by the control sequence (CSI, PI LI F) as defined in Recommendation T.61. This applies to the function select horizontal spacing (SHS) for a character pitch, select vertical spacing (SVS) for a line pitch and select graphic rendition (SGR) for a graphic rendition. This also applies to the functions graphic size modification (GSM) and select presentation direction (SPD) for Japanese Kanji and Chinese ideogram capabilities and to character orientation function (COF) for Chinese ideogram capabilities. When more than one such character sequence is to be indicated, a single space shall be inserted between them. Only one parameter value is allowed within a CSI sequence.
+
+TABLE 4/T.62 bis
+
+| Bits                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           | 8 | 7 | 6                       | 5 | 4 | 3 | 2 | 1 |          | Format                                                                                     |      |   |   |         |  |   |   |                         |  |   |   |                 |  |   |   |                |
+|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---|---|-------------------------|---|---|---|---|---|----------|--------------------------------------------------------------------------------------------|------|---|---|---------|--|---|---|-------------------------|--|---|---|-----------------|--|---|---|----------------|
+|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                | 0 | 0 | 0                       | 0 | 0 | 0 | 0 | 1 | (option) | ISO A4, horizontal and vertical                                                            |      |   |   |         |  |   |   |                         |  |   |   |                 |  |   |   |                |
+|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                | 0 | 0 | 0                       | 0 | 0 | 0 | 1 | 0 | (option) | North American, horizontal and vertical                                                    |      |   |   |         |  |   |   |                         |  |   |   |                 |  |   |   |                |
+|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                | 1 | 0 | 0                       | 0 | 0 | 1 | 0 | 0 | (option) | ISO A4 extended (ISO standard 3535), vertical                                              |      |   |   |         |  |   |   |                         |  |   |   |                 |  |   |   |                |
+|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                | 0 | 1 | 0                       | 0 | 0 | 1 | 0 | 0 | (option) | ISO A4 extended (ISO standard 3535), horizontal                                            |      |   |   |         |  |   |   |                         |  |   |   |                 |  |   |   |                |
+|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                | 1 | 0 | 0                       | 0 | 1 | 0 | 0 | 0 | (option) | North American Legal, vertical                                                             |      |   |   |         |  |   |   |                         |  |   |   |                 |  |   |   |                |
+|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                | 0 | 1 | 0                       | 0 | 1 | 0 | 0 | 0 | (option) | North American Legal, horizontal                                                           |      |   |   |         |  |   |   |                         |  |   |   |                 |  |   |   |                |
+|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                | 0 | 0 | 0                       | 0 | 0 | 0 | 1 | 1 | (option) | ISO A4, horizontal and vertical (for use by Japanese Kanji and Chinese ideogram terminals) |      |   |   |         |  |   |   |                         |  |   |   |                 |  |   |   |                |
+|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                | 0 | 0 | 0                       | 1 | 0 | 0 | 0 | 0 | (option) | ISO B5, horizontal and vertical (for use by Japanese Kanji and Chinese ideogram terminals) |      |   |   |         |  |   |   |                         |  |   |   |                 |  |   |   |                |
+|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                | 0 | 0 | 1                       | 0 | 0 | 0 | 0 | 0 | (option) | ISO B4, horizontal and vertical (for use by Japanese Kanji and Chinese ideogram terminals) |      |   |   |         |  |   |   |                         |  |   |   |                 |  |   |   |                |
+| <p>NOTES</p> <p>1 The whole octet has to be considered when decoded, as the meaning is coded as a value, not as a single bit position within the octet. All other values are reserved, i.e. it is not allowed to ‘combine’ the indication of several formats into the same octet by setting more than one bit to ‘one’.</p> <p>2 The following rule is used for the coding of bits 7 and 8:</p> <table style="margin-left: 40px;"> <tr> <td>Bits</td> <td>8</td> <td>7</td> <td>Meaning</td> </tr> <tr> <td></td> <td>0</td> <td>0</td> <td>Vertical and horizontal</td> </tr> <tr> <td></td> <td>0</td> <td>1</td> <td>Horizontal only</td> </tr> <tr> <td></td> <td>1</td> <td>0</td> <td>Vertical only.</td> </tr> </table> |   |   |                         |   |   |   |   |   |          |                                                                                            | Bits | 8 | 7 | Meaning |  | 0 | 0 | Vertical and horizontal |  | 0 | 1 | Horizontal only |  | 1 | 0 | Vertical only. |
+| Bits                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           | 8 | 7 | Meaning                 |   |   |   |   |   |          |                                                                                            |      |   |   |         |  |   |   |                         |  |   |   |                 |  |   |   |                |
+|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                | 0 | 0 | Vertical and horizontal |   |   |   |   |   |          |                                                                                            |      |   |   |         |  |   |   |                         |  |   |   |                 |  |   |   |                |
+|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                | 0 | 1 | Horizontal only         |   |   |   |   |   |          |                                                                                            |      |   |   |         |  |   |   |                         |  |   |   |                 |  |   |   |                |
+|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                | 1 | 0 | Vertical only.          |   |   |   |   |   |          |                                                                                            |      |   |   |         |  |   |   |                         |  |   |   |                 |  |   |   |                |
+
+## 4.3 Session termination phase
+
+The following service primitives are used:
+
+- S-RELEASE;
+- S-U-ABORT;
+- S-P-ABORT.
+
+### 4.3.1 The parameters of the S-RELEASE are used as follows:
+
+*Result* – This parameter will indicate ‘affirmative’ (only in confirmation and response).
+
+*SS-user-data* – This parameter is not used in Teletex and Group 4 facsimile services.
+
+### 4.3.2 S-U-ABORT
+
+Using this primitive will be interpreted as ‘local terminal error’.
+
+- *SS-user-data* – this parameter is not used in Teletex and Group 4 facsimile services. Since the S-U-ABORT service is a confirmed service in Recommendation T.62 and an unconfirmed service in Recommendation X.215, means must be provided (e.g. by implementors of this Recommendation or the SS-user) in order to cope with that difference when using this Recommendation.
+
+### 4.3.3 S-P-ABORT
+
+Receipt of this primitive is defined in Recommendations X.215 and X.225.
+
+## 4.4 Data transfer phase
+
+The following service primitives are used:
+
+S-ACTIVITY-START  
+S-ACTIVITY-RESUME  
+S-ACTIVITY-INTERRUPT  
+S-ACTIVITY-DISCARD  
+S-ACTIVITY-END  
+S-SYNC-MINOR  
+S-U-EXCEPTION-REPORT  
+S-P-EXCEPTION-REPORT  
+S-CONTROL-GIVE  
+S-TOKEN-PLEASE  
+S-CAPABILITY-DATA  
+S-DATA
+
+### 4.4.1 S-ACTIVITY-START
+
+4.4.1.1 The parameters of S-ACTIVITY-START are used as follows
+
+- *Activity identifier* – This mandatory parameter shall contain the document reference number (see 3.5.6).
+- *SS-user-data* – This non-mandatory parameter is used to convey data of the presentation and/or application protocol(s). All information necessary to negotiate the document interchange protocol parameters, defined in the T.400-Series Recommendations, is contained in this parameter field.
+
+#### 4.4.1.2 Additional parameters
+
+The following parameters may also be included:
+
+- a) *Document type identifier* – Not a mandatory field. If a normal document is used, this parameter shall not be indicated. If other types of document are used, the inclusion of this field is obligatory.
+
+(Description of types of document are given in Annex A.)
+
+- b) *Service interworking identifier* – Not a mandatory field. This parameter may be used to indicate that the document is suitable for interworking; however use of this parameter is mandatory in the case of service interworking.
+
+NOTE – When communicating with a conversion facility, an identifier may be required for:
+
+- i) Teletex/telex interworking – The identifier will indicate that the document(s) has been prepared in accordance with the rules given in Recommendations F.200, T.90 and T.91;
+- ii) Teletex/Videotex interworking – For further study;
+- iii) Teletex/facsimile interworking – For further study.
+- c) *Indication of required terminal capability* (standardized or private use) – Not a mandatory field, however, this parameter must be used if standardized optional terminal capabilities are required for the document.
+- d) *Private use parameters* – Non mandatory. Definition of such parameters is not standardized (see 3.2).
+
+#### 4.4.1.3 Encoding of the S-ACTIVITY-START additional parameters value
+
+- a) *Document type identifier*
+
+Absence of this parameter shall indicate a normal document. This parameter, if used, is a binary encoded field of fixed length of one octet identifying the document type as follows:
+
+| Bits | 87654321 | Type of document  |
+|------|----------|-------------------|
+|      | 00000001 | Operator document |
+|      | 00000010 | Control document  |
+|      | 00000011 | Monitor document  |
+
+All other encodings are reserved for future standardization.
+
+##### b) *Service interworking identifier*
+
+Bit 1 of the first octet set to 1 shall indicate that the associated document is suitable for forwarding via the telex service.
+
+All other bit values are reserved for future standardization.
+
+##### c) *Indication of required terminal capability* (non-basic Teletex terminal capabilities)
+
+- Graphic character sets (refer to Recommendations T.60 and T.61)
+
+A variable length field indicating the receiving capabilities for non-basic standardized graphic character sets. Each such graphic character sets or DRCS (dynamically redefinable character set) for Japanese Kanji and Chinese ideogram characters shall be indicated by the sequence of characters used to designate that set, as defined in Recommendation T.61. Where more than one such character set are to be indicated, the ESC character fulfills the purpose of a separator between the character set indicators.
+
+The following descriptions apply to the use of a DRCS set for Japanese Kanji and Chinese ideogram characters:
+
+- i) if the DRCS set is indicated as a parameter value associated with a S-ACTIVITY-START or S-ACTIVITY-RESUME, this should be followed by combinations of a character code (CC) to be registered to the DRCS set and its character dot pattern (DP);
+- ii) the field length of a character code is defined by the DRCS set and that of a character dot pattern is indicated as parameter values of a character box height and a character box width parameters.
+
+NOTE – The value of this parameter in either S-ACTIVITY-START or S-ACTIVITY-RESUME will be as follows:
+
+DRCS CC1 DP1 CC2 DP2 . . . CCi DPi.
+
+- Control character sets (see 4.2.3.5)
+- Teletex page format (see 4.2.3.7)
+- Miscellaneous Teletex terminal capabilities (see 4.2.3.8)
+- Character box height
+
+A variable length field indicating the receiving capabilities for the number of dots of the character box height. The number of dots shall be indicated by the numeric parameter as defined in Recommendation T.61.
+
+Further study is required for indicating more than one value.
+
+- Character box width
+
+A variable length field indicating the receiving capabilities for the number of dots of the character box height. The number of dots shall be indicated by the numeric parameter as defined in Recommendation T.61.
+
+Further study is required for indicating more than one value.
+
+### 4.4.2 S-ACTIVITY-RESUME
+
+#### 4.4.2.1 The parameters of S-ACTIVITY-RESUME are used as follows
+
+- *Old session connection identifier* (mandatory only if linking is attempted on a new session connection) – This non-mandatory parameter shall contain the old session connection identifier, identifying the session in which the first part of the document was sent.
+  - a) calling SS-user-reference (mandatory) see 4.2.1;
+  - b) called SS-user-reference (mandatory) see 4.2.1;
+  - c) common reference (mandatory) see 4.2.1;
+  - d) additional reference information (non-mandatory) see 4.2.1.
+- *Old activity identifier* – This mandatory parameter shall contain the activity identifier (document reference number) of the corresponding S-ACTIVITY-START.
+- *Synchronization point serial number* – This mandatory parameter shall contain the synchronization point serial number (checkpoint reference number) from which the transmission is being continued.
+
+- *Activity identifier* – The new activity identifier shall contain the document reference number as defined in 3.5.7.
+- *SS-user-data* – This non-mandatory parameter is used to convey data of the presentation and/or application protocol(s). All information necessary to negotiate the document interchange protocol parameters, defined in the T.400-Series Recommendations, is contained in this parameter field.
+
+#### 4.4.2.2 Additional parameters
+
+The following parameters may also be included:
+
+- a) *Document type identifier* [see 4.4.1.2 a)].
+- b) *Service interworking identifier* [see 4.4.1.2 b)].
+- c) Optionally, any other parameter field that appears in the S-ACTIVITY-START at the start of the document may be repeated in the S-ACTIVITY-RESUME. Indication of required terminal capability is mandatory if standardized optional terminal capabilities are required for the document. A terminal receiving an S-ACTIVITY-RESUME that does not contain all of the terminal capabilities should not reject the continuation of the document.
+
+#### 4.4.2.3 Encoding of the S-ACTIVITY-RESUME additional parameters
+
+- a) *Document type identifier* [see 4.4.1.3 a)].
+- b) *Service interworking identifier* [see 4.4.1.3 b)].
+- c) *Indication of required terminal capability* (see 4.4.1.3 c)].
+
+### 4.4.3 S-ACTIVITY-INTERRUPT
+
+The parameters of S-ACTIVITY-INTERRUPT are used as follows:
+
+*Reason* – If used, this non-mandatory parameter shall contain only one of the following reasons:
+
+- a) unable to continue the session (e.g. due to memory full, out of recording paper);
+- b) sequence error;
+- c) local terminal error;
+- d) unrecoverable procedural error;
+- e) no specific reason stated (used for reasons other than those listed).
+
+### 4.4.4 S-ACTIVITY-DISCARD
+
+The parameters of S-ACTIVITY-DISCARD are used as follows:
+
+*Reason* – if used, this non-mandatory parameter shall contain only one of the following reasons:
+
+- a) unable to continue the session (e.g. due to memory full, out of recording paper);
+- b) sequence error;
+- c) local terminal error;
+- d) unrecoverable procedural error;
+- e) no specific reason stated (used for reasons other than those listed).
+
+### 4.4.5 S-ACTIVITY-END
+
+The parameters of S-ACTIVITY-END used as follows:
+
+- *Synchronization point serial number* – This mandatory parameter represents the synchronization point serial number (final checkpoint reference number) to which a response shall be made.
+- *SS-user-data* – This parameter is not used, in Teletex and Group 4 facsimile services.
+
+### 4.4.6 S-SYNC-MINOR
+
+The parameters of S-SYNC-MINOR are used as follows:
+
+- *Type* – This mandatory parameter (only in request and indication) will indicate “explicit”.
+
+- *Synchronization point serial number* – This mandatory parameter is the checkpoint reference number, which, in the basic services, is the page reference number.
+- *SS-user-data* – This parameter is not used in the request/indication. In the response/confirmation it represents the parameter “receiving ability jeopardized”. This mandatory parameter (in response and confirmation) indicates whether or not the ability of the receiving terminal to continue to accept the traffic is jeopardized.
+
+The SS-user shall ensure that the first octet is encoded as follows:
+
+|      |          |                                                    |
+|------|----------|----------------------------------------------------|
+| Bits | 87654321 | Meaning                                            |
+|      | 00000000 | Further traffic can be accepted                    |
+|      | 00000001 | Ability to receive further traffic is jeopardized. |
+
+All other binary values are reserved for future standardization.
+
+### 4.4.7 S-U-EXCEPTION-REPORT
+
+The parameters of S-U-EXCEPTION-REPORT are used as follows:
+
+- *Reason* – The value of this mandatory parameter should be one of the following:
+  - a) unable to continue the session (e.g. due to memory full, out of recording paper). This value corresponds to the value “SS-user receiving ability jeopardized”;
+  - b) sequence error;
+  - c) local terminal error;
+  - d) unrecoverable procedural error;
+  - e) no specific reason stated (used for reasons other than those listed).
+- *SS-user-data* – This parameter is not used in Teletex and Group 4 facsimile services.
+
+### 4.4.8 S-P-EXCEPTION-REPORT
+
+4.4.8.1 The parameters of S-P-EXCEPTION-REPORT are used as follows:
+
+*Reason* – This mandatory parameter will indicate “protocol error”.
+
+#### 4.4.8.2 Additional parameters
+
+*Reflect parameter value* – This mandatory parameter shall contain the bit pattern of the SPDU in error, up to and including the detected error.
+
+### 4.4.9 S-CONTROL-GIVE
+
+Use of these primitives are defined in Recommendations X.215 and X.225.
+
+Since the S-CONTROL-GIVE service is a confirmed service in Recommendation T.62 and an unconfirmed service in Recommendation X.215, means must be provided (e.g. by implementors of this Recommendation or the SS-user) in order to cope with that difference when using this Recommendation.
+
+### 4.4.10 S-TOKEN-PLEASE
+
+The parameters of S-TOKEN-PLEASE are used as follows:
+
+- *Token* – This mandatory parameter shall contain the session control function parameter and will indicate “data token”.
+- *SS-user-data* – This parameter is not used in Teletex and Group 4 facsimile services.
+
+### 4.4.11 S-CAPABILITY-DATA
+
+4.4.11.1 The parameters of S-CAPABILITY-DATA are used as follows
+
+- *SS-user-data* – This non-mandatory parameter is used to convey data of the presentation and/or application protocol(s). All information necessary to negotiate the document interchange protocol parameters, defined in the T.400-Series Recommendations, is contained in this parameter field.
+
+#### 4.4.11.2 Additional parameters
+
+The following parameters may also be included:
+
+- a) *Inactivity timer* – This non-mandatory parameter is used to negotiate the value of the inactivity timer.
+- b) *Storage capacity negotiation* – This non-mandatory parameter is used to negotiate the available memory of the remote terminal.
+- c) *Private use parameters* – These parameters are not mandatory. Their definition and use are not standardized.
+- d) *Non-standardized capabilities* – This non-mandatory parameter is used to ascertain compatibility regarding the use of non-standardized terminal capabilities.
+
+And either
+
+- e) *Acceptance of S-CAPABILITY-DATA parameter* – This non-mandatory parameter is used to confirm that all the requested non-basic Teletex terminal capabilities are available at the receiver (only in response and confirmation).
+- f) *Non-basic Teletex terminal capabilities* [see 4.4.1.3 c)] – This non-mandatory parameter indicates one of the following:
+  - the complete list of all the capabilities requested in the CDCL;
+  - a list of the requested capabilities that are available at the receiver. Absence of parameters associated with non-basic capabilities indicates that the requested capabilities are not available at the receiver;
+  - a complete list of non-basic receiving capabilities irrespective of the requested ones.
+
+#### 4.4.11.3 Encoding of S-CAPABILITY-DATA additional parameters
+
+- a) *Inactivity timer* (see 4.2.3.4);
+- b) *Non-basic Teletex terminal capabilities* [see 4.4.1.3 c)];
+- c) *Acceptance of S-CAPABILITY-DATA parameter*.
+
+Bit 1 of the first octet set to 1 indicates acceptance of all non-basic terminal capabilities requested by a S-CAPABILITY-DATA request (except those indicated in the SS-user-data). All other bit values are reserved for future standardization.
+
+- d) *Storage capacity negotiation*
+
+A fixed sequence of two octets to indicate the required amount of storage:
+
+- 1) Bit 1 of the first octet set to 1 indicates that a terminal has received the requested amount of storage.
+- 2) Bit 2 of the first octet set to 1 indicates that the binary field in the following octet contains a number indicating storage capacity required/reserved in kilo-octets.
+- 3) Bit 5 of the first octet set to 1 indicates that the binary field in the following octet contains a number which, when multiplied by 16, indicates storage capacity required/reserved in kilo-octets.
+- 4) Bit 6 of the first octet set to 1 indicates that the binary field in the following octet contains a number which, when multiplied by 256, indicates storage capacity required/reserved in kilo-octets.
+- 5) Bit 3 of the first octet set to 1 indicates that a terminal cannot estimate its memory capacity.
+- 6) Bit 4 of the first octet set to 1 indicates that a terminal cannot now reserve the requested amount of memory.
+- 7) In the first octet, only one of bit 2, 5 and 6 may be set to one. For negotiation of storage capacity less than or equal to 255 kilo-octets, bit 2 shall be used.
+
+NOTE – Use of bit 5 for negotiation of a storage capacity greater than 65 kilo-octets but less or equal to 255 kilo-octets is not to be interpreted as a procedural error by the receiver.
+
+- 8) Bits 7 and 8 of the first octet are reserved for future standardization.
+
+Octet 2 indicates the memory size available and/or reserved (the meaning is defined in the first octet). It shall be set to 11111111 if bit 3 and/or 4 in the first octet is set to 1.
+
+In cases 1), 5) and 6), the second octet may be ignored by the recipient of the S-CAPABILITY-DATA confirmation.
+
+##### e) *Non-standardized capabilities*
+
+The first octet represents the registered CCITT country code as specified in Recommendation T.35 to be used to identify non-standard capabilities. Additional octets may be specified by each country's Administration.
+
+### 4.4.12 D-DATA
+
+Uses of these primitives are defined in Recommendations X.215 and X.225.
+
+# 5 Recommendations for implementing the session layer
+
+To support the control procedures the following specifications apply in addition to Recommendation X.225.
+
+## 5.1 Additional parameters
+
+To conform with the control procedures for Teletex and Group 4 facsimile, the implementation must be able to generate and decode the additional parameters in the SPDUs.
+
+NOTE – The session layer is only concerned with the coding of these parameters and their incorporation in the SPDUs, it is not concerned with the parameter values. This means that the specification of maximum length and parameter value encoding is part of the application layer specification.
+
+### 5.1.1 Connect SPU
+
+See Table 5.
+
+TABLE 5/T.62 bis
+
+| PIG                                     | m/nm | Code (dec.) | Code (hex.) | PI                                      | m/nm | Code (dec.) | Code (hex.) |
+|-----------------------------------------|------|-------------|-------------|-----------------------------------------|------|-------------|-------------|
+| Non-basic session capabilities          | nm   | 2           | 2           | Miscellaneous session capabilities      | nm   | 13          | D           |
+|                                         |      |             |             | Window size                             | nm   | 14          | E           |
+|                                         |      |             |             | Service identifier                      | m    | 8           | 8           |
+|                                         |      |             |             | Inactivity timer                        | nm   | 18          | 12          |
+| Non-basic teletex terminal capabilities | nm   | 65          | 41          | Control character sets                  | nm   | 73          | 49          |
+|                                         |      |             |             | Teletex page formats                    | nm   | 74          | 4A          |
+|                                         |      |             |             | Miscellaneous ttx terminal capabilities | nm   | 75          | 4B          |
+| Private use                             | nm   | 224 to 231  | E0 to E7    | Private use                             | nm   | 232 to 255  | E8 to FF    |
+|                                         |      |             |             | Non-standardized capabilities           | nm   | 232         | E8          |
+
+### 5.1.2 Accept SPDU
+
+See Table 6.
+
+TABLE 6/T.62 bis
+
+| PGI                                     | m/nm | Code (dec.) | Code (hex.) | PI                                      | m/nm | Code (dec.) | Code (hex.) |  |  |  |
+|-----------------------------------------|------|-------------|-------------|-----------------------------------------|------|-------------|-------------|--|--|--|
+| Non-basic session capabilities          | nm   | 2           | 2           | Miscellaneous session capabilities      | nm   | 13          | D           |  |  |  |
+|                                         |      |             |             | Window size                             | nm   | 14          | E           |  |  |  |
+|                                         |      |             |             | Service identifier                      | m    | 8           | 8           |  |  |  |
+|                                         |      |             |             | Inactivity timer                        | nm   | 18          | 12          |  |  |  |
+| Non-basic teletex terminal capabilities | nm   | 65          | 41          | Control character sets                  | nm   | 73          | 49          |  |  |  |
+|                                         |      |             |             | Teletex page formats                    | nm   | 74          | 4A          |  |  |  |
+|                                         |      |             |             | Miscellaneous ttx terminal capabilities | nm   | 75          | 4B          |  |  |  |
+| Private use                             | nm   | 224 to 231  | E0 to E7    | Private use                             | nm   | 232 to 255  | E8 to FF    |  |  |  |
+|                                         |      |             |             | Non-standardized capabilities           | nm   | 232         | E8          |  |  |  |
+
+### 5.1.3 Refuse SPDU
+
+See Table 7.
+
+TABLE 7/T.62 bis
+
+| PGI                                     | m/nm | Code (dec.) | Code (hex.) | PI                                      | m/nm | Code (dec.) | Code (hex.) |
+|-----------------------------------------|------|-------------|-------------|-----------------------------------------|------|-------------|-------------|
+| Non-basic session capabilities          | nm   | 2           | 2           | Miscellaneous session capabilities      | nm   | 13          | D           |
+|                                         |      |             |             | Window size                             | nm   | 14          | E           |
+|                                         |      |             |             | Service identifier                      | m    | 8           | 8           |
+| Non-basic teletex terminal capabilities | nm   | 65          | 41          | Control character sets                  | nm   | 73          | 49          |
+|                                         |      |             |             | Teletex page formats                    | nm   | 74          | 4A          |
+|                                         |      |             |             | Miscellaneous ttx terminal capabilities | nm   | 75          | 4B          |
+| Private use                             | nm   | 224 to 231  | E0 to E7    | Private use                             | nm   | 232 to 255  | E8 to FF    |
+| User data                               | nm   | 193         | C1          |                                         |      |             |             |
+
+### 5.1.4 ACTIVITY-START SPDU/ACTIVITY-RESUME SPDU
+
+See Table 8.
+
+TABLE 8/T.62 bis
+
+| PGI                                     | m/nm | Code (dec.) | Code (hex.) | PI                                          | m/nm | Code (dec.) | Code (hex.) |
+|-----------------------------------------|------|-------------|-------------|---------------------------------------------|------|-------------|-------------|
+|                                         |      |             |             | Service interworking identifier             | nm   | 40          | 28          |
+|                                         |      |             |             | Document type identifier                    | nm   | 48          | 30          |
+| Non-basic teletex terminal capabilities | nm   | 65          | 41          | Graphic character set                       | nm   | 72          | 48          |
+|                                         |      |             |             | Control character sets                      | nm   | 73          | 49          |
+|                                         |      |             |             | Teletex page formats                        | nm   | 74          | 4A          |
+|                                         |      |             |             | Miscellaneous teletex terminal capabilities | nm   | 72          | 4B          |
+|                                         |      |             |             | Character box height                        | nm   | 77          | 4D          |
+|                                         |      |             |             | Character box width                         | nm   | 78          | 4E          |
+| Private use                             | nm   | 224 to 231  | E0 to E7    | Private use                                 | nm   | 232 to 255  | E8 to FF    |
+
+### 5.1.5 CAPABILITY-DATA SPDU
+
+See Table 9.
+
+TABLE 9/T.62 bis
+
+| PGI                                     | m/nm | Code (dec.) | Code (hex.) | PI                                          | m/nm | Code (dec.) | Code (hex.) |
+|-----------------------------------------|------|-------------|-------------|---------------------------------------------|------|-------------|-------------|
+|                                         |      |             |             | Inactivity timer                            | nm   | 18          | 12          |
+|                                         |      |             |             | Storage capacity negotiation                | nm   | 45          | 2D          |
+| Non-basic teletex terminal capabilities | nm   | 65          | 41          | Graphic character set                       | nm   | 72          | 48          |
+|                                         |      |             |             | Control character sets                      | nm   | 73          | 49          |
+|                                         |      |             |             | Teletex page formats                        | nm   | 74          | 4A          |
+|                                         |      |             |             | Miscellaneous teletex terminal capabilities | nm   | 72          | 4B          |
+|                                         |      |             |             | Character box height                        | nm   | 75          | 4D          |
+|                                         |      |             |             | Character box width                         | nm   | 77          | 4E          |
+| Private use                             | nm   | 224 to 231  | E0 to E7    | Private use                                 | nm   | 232 to 255  | E8 to FF    |
+|                                         |      |             |             | Non-standardized capabilities               | nm   | 232         | E8          |
+
+### 5.1.6 CAPABILITY-DATA-ACK SPDU
+
+See Table 10.
+
+TABLE 10/T.62 *bis*
+
+| PGI                                     | m/nm | Code (dec.) | Code (hex.) | PI                                          | m/nm | Code (dec.) | Code (hex.) |
+|-----------------------------------------|------|-------------|-------------|---------------------------------------------|------|-------------|-------------|
+|                                         |      |             |             | Inactivity timer                            | nm   | 18          | 12          |
+|                                         |      |             |             | Acceptance of CAPABILITY-DATA parameter     | nm   | 44          | 2C          |
+|                                         |      |             |             | Storage capability negotiation              | nm   | 45          | 2D          |
+| Non-basic teletex terminal capabilities | nm   | 65          | 41          | Graphic character set                       | nm   | 72          | 48          |
+|                                         |      |             |             | Control character sets                      | nm   | 73          | 49          |
+|                                         |      |             |             | Teletex page formats                        | nm   | 74          | 4A          |
+|                                         |      |             |             | Miscellaneous teletex terminal capabilities | nm   | 75          | 4B          |
+|                                         |      |             |             | Character box height                        | nm   | 77          | 4D          |
+|                                         |      |             |             | Character box width                         | nm   | 78          | 4E          |
+| Private use                             | nm   | 224 to 231  | E0 to E7    | Private use                                 | nm   | 232 to 255  | E8 to FF    |
+|                                         |      |             |             | Non-standardized capabilities               | nm   | 232         | E8          |
+
+## 5.2 Implementation choices
+
+The choices for implementing the OSI session layer are indicated below in order to allow interworking with Teletex and Group 4 facsimile equipment.
+
+**5.2.1** The S-TOKEN-PLEASE service must be implemented so that, in Teletex and Group 4 facsimile services mode of operations:
+
+- The PT SPDU is in principle concatenated with a category 2 SPDU. The way this service is implemented for modes of operations different from Teletex and Group 4 facsimile services is a local matter.
+- When the session is intentionally left inactive for a period of time, the PT SPDU can be sent without being concatenated. For the Teletex and Group 4 facsimile service this requires a preceding negotiation of the inactivity timer to a different value from the default value.
+
+NOTE – The SPDU GIVE TOKENS (GT) may never be transmitted alone nor may include a “token item” parameter because the use of the S-GIVE-TOKEN service is not permitted in basic Teletex and Group 4 facsimile.
+
+**5.2.2** When sending one of the following SPDUs the whole parameter must be absent (i.e. PI, LI, PV fields) when the PV field has to be absent (i.e. when LI = 0): token item parameter in PT and GT SPDUs, user data in FN, DN, AB, ED, AE, AEA, AS and AR SPDUs, enclosure item in DT SPDU and sync type item in MIP SPDU.
+
+**5.2.3** The sum of the numbers of digits contained in the checkpoint reference number (synchronization point serial number) and the document reference number (activity identifier) shall not exceed six, to permit printing in the available space in the call identification line as defined in Recommendation F.200. There is no constraint on the maximum number of digits in either number, as long as this limitation is not exceeded.
+
+**5.2.4** The reception of a length indicator with a value lower than 255 in a 3 octets field must not lead to a protocol error.
+
+**5.2.5** When receiving an AB SPDU the AA SPDU must be sent back even if the transport connection is not to be kept (Recommendation X.225 allows the user to choose between disconnecting the transport or sending the SPDU AA when AB is received).
+
+The telematic services do not use the “reflect parameter values” parameter in the AB SPDU.
+
+**5.2.6** When receiving the CN, AC, CD or CDA SPDUs the non-standardized parameter codes or the parameters which are not part of these SPDU encoding, must be ignored.
+
+**5.2.7** The TIM timer value must be 4 seconds.
+
+**5.2.8** The PGI “connect/accept” (code 5) and the PI “session requirements” (code 20) must not be transmitted in the CN or AC SPDU, if their values are the same as their default values (for Teletex and G4 facsimile, the default values apply). The parameters version number (code 22) and transport disconnect (code 17) must not be transmitted in the RF SPDU. The RF SPDU may also contain an additional user data parameter.
+
+**5.2.9** The absence of non-mandatory PI or PGI indicates that no such functions are available. Therefore PIs or PGIs with LI set to zero should be avoided.
+
+**5.2.10** When a PV conains graphic characters that may be printed or displayed, they shall be in the intended printing/display sequence and shall be coded as defined in Recommendation T.61.
+
+**5.2.11** Segmentation is not used.
+
+### **5.2.12 Definition of valid/invalid session protocol data units**
+
+In addition to the rules expressed in Recommendation X.225, the following applies.
+
+#### **5.2.12.1 Invalid PDUs (definitions and rules)**
+
+If the PDUs do not meet the following conditions, such PDUs are invalid:
+
+- a) the sum of LIs of PGIs and freestanding PIs is equal to the overall LI;
+- b) the sum of the LIs of PIs embedded within recognized PGIs is equal to the PGIs LI;
+- c) for all mandatory parameters, the PGIs or PIs are present and the LIs are not equal to zero.
+
+##### NOTES
+
+1 In the case of AB, AA and RF PDUs, the same checking rules may be applied. However, it is recognized that no externally visible procedure is provided to react to the detection of such invalid PDUs.
+
+2 Invalid ED or ER can either be rejected or processed normally to start error recovery.
+
+3 When receiving an invalid CN it is recommended that the connection be refused by sending a RF with the appropriate parameters and not to release the transport connection.
+
+4 An equipment is not required to make any checking at all on parameters it does not support. In such cases it may also omit the checking of the overall LI. In particular, it should be noted that no recognized parameters, e.g. new parameters, may appear either between supported parameters or after the complete set of supported parameters.
+
+#### 5.2.12.2 Valid PDUs (rules for mandatory acceptance of PDUs)
+
+An SPDU shall not be rejected if it does not meet the rejection conditions described in C.2. They must not be rejected for any of the following conditions:
+
+- a) the presence of a non-mandatory PI or PGI having an LI = 0;
+- b) the presence of any 3-octet LI, the coding of which follows the rules described in this Recommendation and in Recommendation X.225;
+- c) the presence of any correctly formed PV for which future values can be assigned;
+- d) the presence of one or more undefined PIs or PGIs in CN or CD and their corresponding responses;
+- e) the presence of a T.61 coded hyphen (“-”) instead of a colon (“:”) as the parameter between the hours and minutes of the date and time PV in CN;
+- f) the length of the synchronization point serial number in MIA greater or less than the length of the synchronization point serial number in the corresponding MIP (with more or less preceding zeros);
+- g) more PV in AC or RF than in CN.
+
+NOTE – The scope of these rules is restricted to the determination of protocol element validity (formal validity) and they do not impact on rejection or protocol elements due to the functions they invoke.
+
+# Annex A
+
+## Definitions
+
+(This annex forms an integral part of this Recommendation)
+
+NOTE – Some of the terms used in this Recommendation have been defined in ways that may differ from the meanings of similar terms in other Recommendations.
+
+## A.1 General
+
+**A.1.1 Teletex terminal:** A device that is capable of transmitting and receiving Teletex documents in accordance with the basic requirements of Recommendation T.60.
+
+**A.1.2 calling terminal:** The terminal that initiates the procedures to establish a connection.
+
+**A.1.3 called terminal:** A terminal with whom a calling terminal wants to establish a connection.
+
+**A.1.4 Group 4 facsimile apparatus:** A device that is capable of transmitting and receiving facsimile documents in accordance with the basic requirements of Recommendation T.563.
+
+**A.1.5 service interworking:** The facility of sending and receiving information between a Teletex terminal and a terminal of another service, e.g. telex.
+
+## A.2 Session layer mode of communication
+
+For the session layer, three different modes of communication are identified:
+
+**A.2.1 one-way communication (OWC):** User information is transferred in one direction only during the session, i.e. only one of the terminals will have the right to be the source.
+
+**A.2.2 two-way alternate (TWA):** User information is transferred in both directions, but only in one direction at a time, i.e. the source/sink relation will be changed one or more times during the session. This is also called the half-duplex mode.
+
+**A.2.3 two-way simultaneous (TWS):** User information is transferred in both directions simultaneously, i.e. both terminals are simultaneously a source as well as a sink. This is also called the duplex mode.
+
+## **A.3 Terms specific to document**
+
+**A.3.1 document:** A document is a sequence of one or more pages intended by the originator to be delivered to the address(es) as a single entity in the original page sequence.
+
+**A.3.2 page:** The basic element of office correspondence in the telematic service. One A4 (or A4L, North American standard or North American legal) page or the information that may be presented on it.
+
+**A.3.3 checkpoint:** A checkpoint is a numbered mark inserted by the sender in the text stream to provide a reference point for error recovery.
+
+**A.3.4 acknowledgement window:** The maximum number of checkpoints that a sender can transmit without receiving an acknowledgement from the receiver.
+
+# **Annex B**
+
+## **State diagrams**
+
+(This annex forms an integral part of this Recommendation)
+
+**B.1** Each state diagram is in only one state at any time.
+
+**B.2** Each state is represented as an ellipse, which contains a number for reference and a descriptive name.
+
+**B.3** Permissible transitions from one state to another are shown as connecting lines with an arrow indicating the permitted direction of the state transition and labelled with the event or events that cause that transition.
+
+**B.4** Where a transition may originate from any of several states, it may be indicated by a broad arrow terminating on the destination state and labelled with the permissible states of originating and with the event or events that cause that entry into the destination state.
+
+**B.5** An event is either the sending (S-) or reception (R-) of a request or a response or an indicated local operation.
+
+**B.6** Each state diagram has a state named “idle” and numbered zero. This is the initial or reset state when that state diagram is inactive.
+
+**B.7** Upon sending any request that causes entry into a state named “demand response”, the sending of any additional requests is not permitted until a response is received. A demand response timer is started, and if a response is not received prior to expiration of that time-out, session terminating is mandatory.
+
+**B.8** The effect of each event that causes a state transition must be completed prior to consideration of a subsequent event.
+
+**B.9** During a session, each session partner has a responsibility for monitoring for proper operation as follows:
+
+- a) maintenance of the currently agreed source/sink relationship;
+- b) proper use of request/response procedural sequences as described in the state diagrams and the rules of their operation;
+- c) monitoring of a period of inactivity (e.g. indicating a failure or other inability to continue productive use of the session).
+
+Upon detection of a failure to maintain proper operation as described above, use of the error recovery procedures defined for each state diagram is mandatory, or where such error recovery procedures are not specifically defined, session termination (abnormal end) is mandatory. This is necessary in order to avoid unproductive use of telematic facilities, incurring unnecessary charges where the service is not being used effectively, and causing degradation of the service.
+
+**B.10** The purpose of the state diagrams is to assist in defining proper use of the elements of procedure, and not to define any particular implementation.
+
+![Detailed state transition diagram for the sending side of a protocol. The diagram shows various states (DS 1, DS 2, DS 3, DS 4, DS 5, DS 6, DS 7, DS 8, DS 9) and transitions between them triggered by events like S-U-DISC req, S-P-EXPT ind, S-ACT-DISC req, S-ACT-INT req, S-ACT-INT conf, S-ACT-END conf, S-SYNC-MIN conf, S-DATA req, S-SYNC-MIN req, S-SYNC-MIN reg, S-CAPAB-DATA req, S-CAPAB-DATA conf, S-ACT-START req, S-ACT-RSME req, and S-ACT-INT req. States contain actions like Start T2, Stop T2, Wait, and state updates (e.g., R = R + 1, S = S + 1). Transitions are labeled with conditions like (K) and (S > R).](69b7bd65e85cdef6fdd7fb0a8194257c_img.jpg)
+
+**Legend:**
+
+- T2: Demand response timer (60 s)
+- S: Indicates the next allowed checkpoint reference number for an S-SYNC-MINOR-request or S-ACTIVITY-END-request (corresponds to V(M) in X.215/X.225)
+- R: Indicates the next expected checkpoint reference number in a SYNC-MINOR-confirm or S-ACTIVITY-END-confirm (corresponds to V(A) in X.215/X.225)
+- I: An actual checkpoint reference number in an S-SYNC-MINOR-request or S-ACTIVITY-END-request
+- K: An actual checkpoint reference number in an S-SYNC-MINOR-confirm or S-ACTIVITY-END-confirm
+- W: Acknowledgement window size
+- C: A checkpoint reference number from which the source will resume transmission (in case of continuation with S-ACTIVITY-RESUME)
+
+Detailed state transition diagram for the sending side of a protocol. The diagram shows various states (DS 1, DS 2, DS 3, DS 4, DS 5, DS 6, DS 7, DS 8, DS 9) and transitions between them triggered by events like S-U-DISC req, S-P-EXPT ind, S-ACT-DISC req, S-ACT-INT req, S-ACT-INT conf, S-ACT-END conf, S-SYNC-MIN conf, S-DATA req, S-SYNC-MIN req, S-SYNC-MIN reg, S-CAPAB-DATA req, S-CAPAB-DATA conf, S-ACT-START req, S-ACT-RSME req, and S-ACT-INT req. States contain actions like Start T2, Stop T2, Wait, and state updates (e.g., R = R + 1, S = S + 1). Transitions are labeled with conditions like (K) and (S > R).
+
+FIGURE B.1/T.62 *bis*  
+Detailed state transition diagram for the sending side
+
+![Detailed state transition diagram for the receiving side of a protocol. The diagram shows various states (DR 1, DR 1.1, DR 2, DR 2.1, DR 3, DR 4, DR 5, DR 6, DR 7, DR 8, DR 9) and transitions between them. Key transitions include S-U-EXPT reg, S-P-EXPT ind, S-ACT-DISC ind, S-ACT-INT ind, S-ACT-INT resp, S-ACT-END resp (K), S-ACT-RSME ind (C), S-DATA ind, S-SYNC-MIN ind (I), S-SYNC-MIN resp (K), S-CAPAB-DATA ind, and S-CAPAB-DATA resp. States often contain sub-states like 'Wait' or 'Restart T1' and internal logic such as P = Q = C + 1, Q = Q + 1, or P = P + 1. A legend defines variables T1, P, Q, I, K, W, C, and L.](11edb7fcedf09ac6a817f8d7b8c61eec_img.jpg)
+
+T1 Inactivity timer (negotiable; default: 40 s)
+
+P Indicates the next expected checkpoint reference number in an S-SYNC-MINOR-request or S-ACTIVITY-END-request (corresponds to V(M) in X.215/X.225)
+
+Q Indicates the next allowed checkpoint reference number to be acknowledged in an S-SYNC-MINOR-confirm or an S-ACTIVITY-END-confirm (corresponds to V(A) in X.215/X.225)
+
+I An actual checkpoint reference number in an S-SYNC-MINOR-request or an S-ACTIVITY-END-request
+
+K An actual checkpoint reference number in an S-SYNC-MINOR-confirm or an S-ACTIVITY-END-confirm
+
+W Acknowledgement window size
+
+C A checkpoint reference number from which the source will resume transmission (in case of continuation with S-ACTIVITY-RESUME)
+
+\* This primitive shall carry an error parameter if  $I \neq P$  (sequence error)
+
+1) S-ACT-END IND (I)\* and  $(P - Q) \leq (W - 1)$  and  $I = F$
+
+Detailed state transition diagram for the receiving side of a protocol. The diagram shows various states (DR 1, DR 1.1, DR 2, DR 2.1, DR 3, DR 4, DR 5, DR 6, DR 7, DR 8, DR 9) and transitions between them. Key transitions include S-U-EXPT reg, S-P-EXPT ind, S-ACT-DISC ind, S-ACT-INT ind, S-ACT-INT resp, S-ACT-END resp (K), S-ACT-RSME ind (C), S-DATA ind, S-SYNC-MIN ind (I), S-SYNC-MIN resp (K), S-CAPAB-DATA ind, and S-CAPAB-DATA resp. States often contain sub-states like 'Wait' or 'Restart T1' and internal logic such as P = Q = C + 1, Q = Q + 1, or P = P + 1. A legend defines variables T1, P, Q, I, K, W, C, and L.
+
+T0817550-94/d03
+
+FIGURE B-2/T.62 *bis*  
+**Detailed state transition diagram for the receiving side**
+
+![Session timers state transition diagram for the sending side. The diagram shows states 0 through 14, each with specific actions and transitions. State 0 is the central state. Transitions include S-U-ABORT ind, S-P-ABT ind, S-CONNECT req, S-CONNECT conf (reject/accept), S-RELEASE req, S-CONTROL-GIVE req, and various timeouts and discards. Timers T1, T2, and T3 are managed in each state.](c494cd874a082a97b50b3c4d3938f467_img.jpg)
+
+Any state except 7.1, 14.1
+
+S-U-ABORT ind
+
+7
+
+Stop T1, T2
+
+Discard
+
+7.1 Wait
+
+Receive any PDU
+
+Send ABORT accept PDU
+
+S-P-ABT ind
+
+0
+
+Stop T1, T2
+
+Any state except 7.1, 14.1
+
+S-P-EXCEPT ind
+
+Timeout
+
+S-U-ABORT req
+
+14
+
+Start T3
+
+Discard
+
+14.1 Wait
+
+Receive any PDU except ABORT ACCEPT
+
+Receive ABORT accept PDU
+
+Timeout
+
+S-P-ABT ind
+
+Stop T3
+
+8
+
+S-CONNECT conf (reject)
+
+Stop T2
+
+S-CONNECT req
+
+8.1 Wait
+
+Start T2
+
+S-CONNECT conf (accept)
+
+9
+
+Stop T2
+
+DS
+
+Doc send
+
+GIVE TOKENS ACK
+
+12
+
+12.1 Wait
+
+Stop T1
+
+S-CONTROL-GIVE ind
+
+10
+
+Start T2
+
+10.1 Wait
+
+S-RELEASE req
+
+13
+
+13.1 Wait
+
+Start T2
+
+S-RELEASE conf
+
+Stop T2
+
+11
+
+DR
+
+Doc receive
+
+Stop T2
+
+Start T1
+
+GIVE TOKENS ACK
+
+T0809720-92/d04
+
+T1 Inactivity timer  
+T2 Demand response timer  
+T3 Abort timer
+
+Session timers state transition diagram for the sending side. The diagram shows states 0 through 14, each with specific actions and transitions. State 0 is the central state. Transitions include S-U-ABORT ind, S-P-ABT ind, S-CONNECT req, S-CONNECT conf (reject/accept), S-RELEASE req, S-CONTROL-GIVE req, and various timeouts and discards. Timers T1, T2, and T3 are managed in each state.
+
+FIGURE B.3/T.62 bis  
+Session timers state transition diagram for the sending side
+
+![Session timers state transition diagram for the receiving side](692541e65db4dc852988ce77ebb60ce5_img.jpg)
+
+```
+
+    graph TD
+    AnyStateExcept7.1_14.1((Any state except 7.1, 14.1)) -- S-U-ABORT ind --> State7[7]
+    State7 --> StopT1T2[Stop T1, T2]
+    StopT1T2 --> SUABTind[S-U-ABT ind]
+    SUABTind --> State7.1Wait((7.1 Wait))
+
+    AnyStateExcept0.1_0.2_7.1_14.1X((Any state except 0.1, 0.2, 7.1, 14.1 X)) -- S-P-ESPT Fail ind --> AnyStateExcept0.1_0.2_7.1_14.1X
+    AnyStateExcept0.1_0.2_7.1_14.1X -- S-U-ABORT req --> State14[14]
+    State14 --> StartT3[Start T3]
+    StartT3 --> State14.1Wait((14.1 Wait))
+    State14.1Wait -- Timeout --> State0.1
+    State14.1Wait -- Receive ABORT ACCEPT SPDU --> StopT3[Stop T3]
+    State14.1Wait -- R-Any PDU except ABORT ACCEPT --> Discard[Discard]
+    Discard --> State14.1Wait
+
+    subgraph CentralStates [States 0.1 and 0.2]
+    State0.1((0.1 Idle transport disconnected)) -- T-CON req --> StartT1_0.1[Start T1]
+    StartT1_0.1 --> State0.2((0.2 Idle transport connected))
+    State0.2 -- T-DISC req --> StopT1_0.2[Stop T1]
+    StopT1_0.2 --> State0.1
+    State0.2 -- Timeout --> SPASTind[S-P-AST ind]
+    SPASTind --> State0.1
+    end
+
+    State0.2 -- S-CONNECT ind --> State1[1]
+    State1 --> StopT1_1[Stop T1]
+    StopT1_1 --> StartT1_1[Start T1]
+    StartT1_1 --> State1.1Wait((1.1 Wait))
+    State1.1Wait -- S-CONNECT resp reject --> StartT1_0.2
+    State1.1Wait -- S-CONNECT resp accept --> State2[2]
+
+    State2((2 DR Doc. receive)) -- S-RELEASE ind --> State6[6]
+    State6 --> StopT1_6[Stop T1]
+    StopT1_6 --> State6.1Wait((6.1 Wait))
+    State6.1Wait -- S-RELEASE resp --> State0.2
+
+    State2 -- Stop T2 Start T1 --> State3[3]
+    State3((3 S-CONTROL-GIVE ind)) -- Stop T1 --> State3.1Wait((3.1 Wait))
+    State3.1Wait -- GIVE TOKENS ACK SPDU --> State4[4]
+    State4((4 DS Doc. send)) -- S-CONTROL-GIVE req --> State5[5]
+    State5((5 GIVE TOKENS ACK SPDU)) -- Start T2 --> State5.1Wait((5.1 Wait))
+    State5.1Wait -- S-RELEASE ind --> State6
+  
+```
+
+Session timers state transition diagram for the receiving side
+
+T1 Inactivity timer  
+ T2 Demand response timer  
+ T3 Abort timer
+
+FIGURE B.4/T.62 *bis*  
+**Session timers state transition diagram for the receiving side**
+
+28 Recommendation T.62 bis (03/93)
+
+# **Annex C**
+
+## **Types of documents**
+
+(This annex forms an integral part of this Recommendation)
+
+## **C.1 General**
+
+**C.1.1** An indication of the type of document that is transferred shall be given at the start of the document; if not, the normal type of document is used.
+
+**C.1.2** A document type indication will indicate to the operating system of the receiving terminal that a special action is required (the action is defined for each type of document).
+
+**C.1.3** No additional procedure elements or changes in state transition diagrams are required.
+
+## **C.2 Normal document**
+
+**C.2.1** This is the normal type of document to be used to transfer text in the telematic services. Upon reception the document may be immediately printed (in the case of Group 4 facsimile Class 1) or be immediately stored (all other terminals).
+
+**C.2.2** From the procedures point of view, every Teletex terminal must be able to handle this type of document.
+
+NOTE – Where appropriate the rules for the usage of optional functions have to be followed.
+
+## **C.3 Operator document (optional)**
+
+The operator document represents a type of priority message. It can be used in the conventional mode of operation.
+
+It is intended to be presented immediately to the operator (although the decision to present it is left to the receiving operator). It may therefore be immediately indicated to the operator that a new operator document has been received. The operator document shall conform to the same presentation control functions and be treated in the procedure as a normal document. The length of an operator document is arbitrary but, preferably (due to the application), it shall not exceed one page. Note that a terminal that does not have a special dialogue mode can handle an operator document as a normal document.
+
+## **C.4 Control document**
+
+**C.4.1** The control document can be used in communication with intermediate store-and-forward equipment, e.g. interworking with the telex service, in standardized options and national applications.
+
+**C.4.2** The addressing information (and other control information required) can be included as text within such a document. The control document shall, except for the document type indication, follow the same rules (in the procedures) as a normal document. The use of the control document is outside the scope of this Recommendation.
+
+**C.4.3** Teletex terminals shall be able to support the control documents defined in Recommendation T.90 for interworking with the telex service.
+
+## **C.5 Monitor document (optional)**
+
+**C.5.1** The monitor document will not be made available to the user. It is intended to be available for purposes that can be defined by each Administration, e.g. for maintenance purposes.
+
+**C.5.2** The monitor document will be handled by the operating system of the terminal and not displayed to the operator. The monitor document shall, except for the document type indication, conform to the same rules (in the procedure) as a normal document.
+
+# **Annex D**
+
+## **Protocols for interactive applications**
+
+(This annex forms an integral part of this Recommendation)
+
+These protocols are under study.
\ No newline at end of file
diff --git a/marked/T/T-REC-T.701.11-202009-I_PDF-E/raw.md b/marked/T/T-REC-T.701.11-202009-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..4d670c0403fcbc80e659dd86da6fa4ea87ed8d8d
--- /dev/null
+++ b/marked/T/T-REC-T.701.11-202009-I_PDF-E/raw.md
@@ -0,0 +1,1718 @@
+
+
+I n t e r n a t i o n a l   T e l e c o m m u n i c a t i o n   U n i o n
+
+# ITU-T
+
+TELECOMMUNICATION  
+STANDARDIZATION SECTOR  
+OF ITU
+
+# T.701.11
+
+(09/2020)
+
+SERIES T: TERMINALS FOR TELEMATIC SERVICES
+
+User interfaces – Accessibility and human factors
+
+# --- Guidance on text alternatives for images
+
+Recommendation ITU-T T.701.11
+
+## ITU-T T-SERIES RECOMMENDATIONS **TERMINALS FOR TELEMATIC SERVICES**
+
+|                                                          |                    |
+|----------------------------------------------------------|--------------------|
+| Facsimile – Framework                                    | T.0–T.19           |
+| Still-image compression – Test charts                    | T.20–T.29          |
+| Facsimile – Group 3 protocols                            | T.30–T.39          |
+| Colour representation                                    | T.40–T.49          |
+| Character coding                                         | T.50–T.59          |
+| Facsimile – Group 4 protocols                            | T.60–T.69          |
+| Telematic services – Framework                           | T.70–T.79          |
+| Still-image compression – JPEG-1, Bi-level and JBIG      | T.80–T.89          |
+| Telematic services – ISDN Terminals and protocols        | T.90–T.99          |
+| Videotext – Framework                                    | T.100–T.109        |
+| Data protocols for multimedia conferencing               | T.120–T.149        |
+| Telewriting                                              | T.150–T.159        |
+| Multimedia and hypermedia framework                      | T.170–T.189        |
+| Cooperative document handling                            | T.190–T.199        |
+| Telematic services – Interworking                        | T.300–T.399        |
+| Open document architecture                               | T.400–T.429        |
+| Document transfer and manipulation                       | T.430–T.449        |
+| Document application profile                             | T.500–T.509        |
+| Communication application profile                        | T.510–T.559        |
+| Telematic services – Equipment characteristics           | T.560–T.619        |
+| General multimedia application frameworks                | T.620–T.649        |
+| <b>User interfaces – Accessibility and human factors</b> | <b>T.700–T.799</b> |
+| Still-image compression – JPEG 2000                      | T.800–T.829        |
+| Still-image compression   JPEG XR                        | T.830–T.849        |
+| Still-image compression – JPEG-1 extensions              | T.850–T.899        |
+
+*For further details, please refer to the list of ITU-T Recommendations.*
+
+## Recommendation ITU-T T.701.11
+
+# Guidance on text alternatives for images
+
+## Summary
+
+Recommendation ITU-T T.701.11 gives guidance on how to create text alternatives (also known as "alt-text") and what information to put in text alternatives.
+
+This Recommendation applies to all still images that are used in any type of electronic document. It also applies to individual images within a slide show. The alternative text guidance provided in this Recommendation is not applicable to moving images (e.g., movies).
+
+This Recommendation is a twin text with ISO/IEC 20071-11:2019 "Information technology – User interface component accessibility – Part 11: Guidance on text alternatives for images", prepared by ISO/IEC JTC1 SC35 "User interfaces".
+
+## History
+
+| Edition | Recommendation | Approval   | Study Group | Unique ID*                                                                |
+|---------|----------------|------------|-------------|---------------------------------------------------------------------------|
+| 1.0     | ITU-T T.701.11 | 2020-09-29 | 16          | <a href="http://handle.itu.int/11.1002/1000/14358">11.1002/1000/14358</a> |
+
+## Keywords
+
+Accessibility, alt text, documents, images, text alternatives.
+
+---
+
+\* To access the Recommendation, type the URL <http://handle.itu.int/> in the address field of your web browser, followed by the Recommendation's unique ID. For example, <http://handle.itu.int/11.1002/1000/11830-en>.
+
+## FOREWORD
+
+The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis.
+
+The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics.
+
+The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1.
+
+In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC.
+
+## NOTE
+
+In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party.
+
+## INTELLECTUAL PROPERTY RIGHTS
+
+ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process.
+
+As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at <http://www.itu.int/ITU-T/ipr/>.
+
+© ITU 2020
+
+All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU.
+
+# Table of Contents
+
+|      |                                                              | Page |
+|------|--------------------------------------------------------------|------|
+| 1    | Scope                                                        | 1    |
+| 2    | Normative references                                         | 1    |
+| 3    | Definitions                                                  | 1    |
+| 3.1  | Terms defined elsewhere                                      | 1    |
+| 3.2  | Terms defined in this Recommendation                         | 2    |
+| 4    | Abbreviations and acronyms                                   | 4    |
+| 5    | Conventions                                                  | 4    |
+| 6    | Text alternatives for images                                 | 4    |
+| 6.1  | Uses of text alternatives                                    | 4    |
+| 6.2  | Presenting text alternatives                                 | 5    |
+| 7    | Procedure for creating text alternatives                     | 6    |
+| 8    | Identifying the types of image                               | 8    |
+| 8.1  | General                                                      | 8    |
+| 8.2  | Drawings                                                     | 8    |
+| 8.3  | Photographs                                                  | 8    |
+| 8.4  | Diagrams                                                     | 8    |
+| 8.5  | Maps                                                         | 9    |
+| 8.6  | Computer-generated illustrations                             | 9    |
+| 8.7  | Composite images                                             | 9    |
+| 8.8  | Identifying image type in text alternatives                  | 10   |
+| 9    | Identifying the purpose of the image                         | 10   |
+| 9.1  | Introduction to purposes                                     | 10   |
+| 9.2  | Informative purposes                                         | 11   |
+| 9.3  | Control purposes                                             | 11   |
+| 9.4  | Decorative purposes                                          | 11   |
+| 9.5  | Formatting purposes                                          | 12   |
+| 9.6  | Identifying purpose in text alternatives                     | 12   |
+| 10   | Identifying the image components                             | 14   |
+| 10.1 | Images and image components                                  | 14   |
+| 10.2 | Text components                                              | 14   |
+| 10.3 | Uniquely identifying image components                        | 14   |
+| 10.4 | Structuring information about images and their components    | 15   |
+| 10.5 | Dealing with image complexity                                | 16   |
+| 11   | Identifying the information (content) presented by the image | 17   |
+| 11.1 | Content of an image or its components                        | 17   |
+| 11.2 | Subjective content                                           | 17   |
+| 11.3 | Objective content                                            | 18   |
+
+|                                                                                    | <b>Page</b> |
+|------------------------------------------------------------------------------------|-------------|
+| 11.4 Relationship content .....                                                    | 18          |
+| 11.5 Interaction content .....                                                     | 21          |
+| 11.6 Analysing the information presented by an image .....                         | 22          |
+| 12 Evaluating the importance of the information about the image .....              | 22          |
+| 12.1 Importance is context dependent .....                                         | 22          |
+| 12.2 Importance .....                                                              | 22          |
+| 12.3 Textual content in images .....                                               | 24          |
+| 12.4 Using importance to allocate information to text alternatives .....           | 25          |
+| 13 Compose the text alternatives .....                                             | 26          |
+| 13.1 Composition .....                                                             | 26          |
+| 13.2 Organizing the information .....                                              | 26          |
+| 13.3 Wording text alternatives .....                                               | 27          |
+| 13.4 Creating text alternatives .....                                              | 28          |
+| 14 Evaluate the text alternative .....                                             | 28          |
+| 14.1 The range of evaluation issues .....                                          | 28          |
+| 14.2 The range of evaluation methods and testers .....                             | 28          |
+| Appendix I – Further elaboration of objective content of images .....              | 30          |
+| I.1 General .....                                                                  | 30          |
+| I.2 Characteristics of the image or image component .....                          | 30          |
+| I.3 Some temporal properties of images or image components .....                   | 31          |
+| Appendix II – Further considerations for particular types of images .....          | 33          |
+| II.1 Further considerations for particular types of drawings and photographs ..... | 33          |
+| II.2 Further considerations for diagrams and maps .....                            | 34          |
+| II.3 Background images .....                                                       | 36          |
+| Bibliography .....                                                                 | 37          |
+
+# Introduction
+
+The saying that "A picture is worth a thousand words" recognizes that images can present a wealth of information. It is important that alternative textual descriptions or representations present a comprehensive account of the purpose and content of images to people unable to see or interpret them.
+
+Text alternatives help people who cannot see the images to understand what the image is of or the purpose it serves by providing the same information in textual form. Text alternatives can be useful to those with visual impairments, those who turned images off in order to improve webpage loading speeds, and those who cannot understand the image being displayed. They can also aid search engines in finding images. This Recommendation provides guidance for user interface, web and document developers to help them create informative descriptions for various types of illustrations.
+
+While some sources of guidance advocate that text alternatives be kept short, it is important that they provide an equitable alternative to the image. ITU-T H-series Supplement 17 | ISO/IEC Guide 71 states "A system provides equitable use if it allows diverse users to accomplish tasks in an identical manner whenever possible or in an equivalent manner when an identical manner is not possible". This Recommendation provides guidance intended to help developers create equitable text alternatives.
+
+The guidance contained in this Recommendation is intended to be used by the person who creates content and/or text alternatives to be placed in an electronic document. There is no expectation that this person will have any additional expertise beyond understanding the contents of the document and why an image was chosen to be placed within the document.
+
+While the main intent of the guidance within this Recommendation is the creation of text alternatives, the information identified in this guidance could be placed in the main document text, reducing the length of the resulting text alternatives. However, placing information in the main document text does not fully replace the function of having some text alternatives for each image.
+
+
+
+## Recommendation ITU-T T.701.11
+
+# Guidance on text alternatives for images
+
+# 1 Scope
+
+This Recommendation gives guidance on how to create text alternatives and what information to put in text alternatives.
+
+This Recommendation applies to all static images that are used in any type of electronic document. It also applies to individual images within a slide show.
+
+This Recommendation does not apply to moving images (e.g., movies).
+
+NOTE 1 – While text alternatives can be implemented via various mechanisms in various types of electronic documents, the contents of this Recommendation are not dependent on the choice of implementation mechanism or of electronic document type.
+
+NOTE 2 – Guidance on making moving images accessible is contained in [b-ISO/IEC TS 20071-21], [b-ISO/IEC 20071-23] and [b-ISO/IEC 20071-25].
+
+This Recommendation is a twin text with ISO/IEC 20071-11:2019 "Information technology – User interface component accessibility – Part 11: Guidance on text alternatives for images", prepared by ISO/IEC JTC1 SC35 "User interfaces".
+
+# 2 Normative references
+
+The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation.
+
+None.
+
+# 3 Definitions
+
+## **3.1 Terms defined elsewhere**
+
+This Recommendation uses the following terms defined elsewhere:
+
+**3.1.1 content** [b-ISO/IEC/IEEE 23026:2015]: Interactive or non-interactive object containing information represented by text, image, video, sound or other media.
+
+**3.1.2 essential information** [b-ISO/IEC 20071-23]: Information that is necessary to understand the content and/or its function.
+
+**3.1.3 helpful information** [b-ISO/IEC 20071-23]: Information that provides a thorough understanding of the content to some users.
+
+**3.1.4 importance** [b-ISO/IEC 20071-23]: As it relates to information, level of need for users to know information about content.
+
+**3.1.5 significant information** [b-ISO/IEC 20071-23]: Information that provides a more detailed understanding of the content for most users most of the time.
+
+**3.1.6 unhelpful information** [b-ISO/IEC 20071-23]: Information that does not help users understand the content and/or can interfere with that understanding.
+
+## 3.2 Terms defined in this Recommendation
+
+This Recommendation defines the following terms:
+
+**3.2.1 abstract:** Type of content intended to present important major data, information, object, relationship, and/or conceptual components, without faithfully representing them as they occur in the natural world.
+
+EXAMPLE – Cartoons, abstract art (where the basis for abstraction can be recognized), graphs and charts.
+
+**3.2.2 caricature:** Content showing the features of its subject in a simplified or exaggerated way.
+
+**3.2.3 cartoon:** Semi-realistic content that is usually intended to be entertaining.
+
+NOTE – It is typical for cartoons to include unrealistic situations, e.g., animals talking, people performing physical actions that are not possible.
+
+**3.2.4 component:** As it relates to images, identifiable part of an image that provides content for the user.
+
+NOTE 1 – Types of image component include (but not limited to) shapes, objects, persons, areas, and text.
+
+NOTE 2 – Text components can include natural and/or formal languages (such as mathematical equations).
+
+**3.2.5 composite image:** Image created by combining individual images or components of individual images, which can each be accessed as independent components of the composite image.
+
+**3.2.6 computer-generated illustration:** Image created by a computer based on data that it has available to it.
+
+**3.2.7 control (information):** Information that can be used to take some action which manipulates data, other objects or their attributes.
+
+**3.2.8 diagram:** Image containing a graphical representation of a set of (physical, logical, conceptual or other) objects or components and their (physical, logical, sequential or other) relationships.
+
+**3.2.9 drawing:** Image created as an original work through the artistic actions of a human.
+
+**3.2.10 event (information):** Information about a state change, message indicating the occurrence of an action, or conveying a significant change in the world.
+
+**3.2.11 image:** As it relates to digital content, graphical content intended to be presented visually.
+
+NOTE – This includes graphics that are encoded in any electronic format, including, but not limited to, formats that are comprised of individual pixels (e.g., those produced by paint programs or by photographic means) and formats that comprised of formulas (e.g., those produced as scalable vector drawings).
+
+**3.2.12 logical (relationship):** Relationship information about what entities are interacting and how they interact.
+
+**3.2.13 main body of text:** Textual content of a document that is always presented to the users.
+
+**3.3.14 map:** Image containing a geospatial representation of geographic data.
+
+**3.2.15 moving image:** Image where the contents are dynamically changing.
+
+NOTE – This includes realistic moving images (often referred to as movies), abstract moving images (often referred to as cartoons), and even non-representational moving images (often referred to as light shows).
+
+**3.2.16 non-representational:** Type of content intended for decorative purposes without the intent to represent any particular natural world data, information, objects, relationships and/or concepts.
+
+EXAMPLE – Art presenting colours and textures (without any recognizable objective contents).
+
+NOTE – Diagrams, maps and computer-generated illustrations are often presented as composite images.
+
+**3.2.17 photograph:** Electronic copy of an image of something that has its own independent existence in the real world.
+
+**3.2.18 physical (information):** Information about phenomena which have a concrete existence.
+
+EXAMPLE – Objects, agents or scenes that have a physical existence.
+
+NOTE – This can include states and histories of objects.
+
+**3.2.19 physical (relationship):** Spatial relationship information about where one entity is in relation to another entity.
+
+**3.2.20 primary alternative text:** Main text alternative provided to users of screen readers.
+
+NOTE – Different technologies and platforms provide various mechanisms for containing and presenting primary alternative text.
+
+EXAMPLE 1 – In HTML 5.2 and EPUB, primary alternative text is provided in the "alt" attribute of the img tag.
+
+EXAMPLE 2 – In PDF, primary alternative text is provided through the /Alt entry in a structure element's dictionary.
+
+**3.2.21 quantitative (information):** Statistical information or numerical data and the relationships between the numbers.
+
+NOTE 1 – Quantitative information is often presented in a graphical manner.
+
+NOTE 2 – Quantitative images are often used for comparison between related sets of data, such as comparing net profit over a period of time.
+
+NOTE 3 – Examples of quantitative images include charts and graphs.
+
+**3.2.22 realistic:** Type of content that is perceived by the user to faithfully represent data, information, objects, relationships and/or concepts in the natural world.
+
+EXAMPLE – Photographic images, pictures intended to be true-to-life, diagrams used to illustrate how to assemble a set of parts.
+
+**3.2.23 relationship type:** Information about an association between entities.
+
+**3.2.24 secondary alternative text:** Additional text alternative provided to users of screen readers beyond primary alternative text.
+
+NOTE – Different technologies and platforms provide various mechanisms for containing and presenting secondary alternative text.
+
+EXAMPLE 1 – In HTML 5.2, secondary alternative text is provided in the "longdesc" attribute of the img tag.
+
+EXAMPLE 2 – In EPUB, secondary alternative text is provided through the "role" attribute.
+
+**3.2.25 sketch:** Rapidly executed freehand drawing that is not usually intended as a finished fully-realistic work.
+
+NOTE – Sketches are often monochrome line drawings, with or without shading.
+
+**3.2.26 slide show:** Set of images that replace one another periodically.
+
+NOTE 1 – The replacement of one static image by another static image can be controlled automatically by the system (in which case the timing for each image is usually predetermined) or manually by the user (where the timing for each image is determined on a case by case basis).
+
+NOTE 2 – Slide shows are usually composed of static images but can include short movies. The interval between static images in a slide show are considered longer than in a movie, such that the motion being portrayed by the slide show would appear staggered instead of smooth like in a movie.
+
+**3.2.27 state (information):** Properties of the environment, objects or agents that remain constant during a period of time.
+
+**3.2.28 static image:** Image where the set of image components and their relationships to one another do not change over time.
+
+NOTE 1 – This includes images where the content/representation of individual image components can change over time, e.g., indicators where the value they are indicating changes in real time.
+
+NOTE 2 – The concept of static image is used for all images that are not slide shows or moving images.
+
+NOTE 3 – This use of static image is similar to the use of "still image" in [b-ISO/IEC 13249-5]. However, it differs in that a static image can have moving components. [b-ISO/IEC 13249-5] states "A still image user-defined type is generic to image handling. It addresses the need to store, manage, and retrieve information based on aspects of inherent image characteristics such as height, width, and format and based on image features such as average colour, colour histogram, positional colour, and texture. It also addresses the need to employ manipulation such as rotation, scaling as well as similarity assessment".
+
+**3.2.29 temporal (relationship):** Relationship information about when some action or entity occurs.
+
+**3.2.30 text alternative:** Alternative text: textual description or representation of an image.
+
+NOTE 1 – By storing this description or representation in text format, it is able to be rendered in any available modality.
+
+NOTE 2 – The main audience of text alternatives are the users of screen reading features.
+
+NOTE 3 – Text alternatives are often provided to screen reader users in the form of primary and secondary alternative texts of an image.
+
+NOTE 4 – Generally, "text alternative" is used to refer to any text alternative, while "alternative text" is used to refer to text alternatives for images that are contained in attributes of an image.
+
+**3.2.31 value:** Quantitative information describing properties of an object.
+
+# **4 Abbreviations and acronyms**
+
+This Recommendation uses the following abbreviations and acronyms:
+
+|      |                                       |
+|------|---------------------------------------|
+| ARIA | Accessible Rich Internet Applications |
+| EPUB | Electronic Publication                |
+| HTML | Hypertext Markup Language             |
+| IC   | Image Component                       |
+| SGML | Standard Generalized Markup Language  |
+| WI   | Whole Image                           |
+
+# **5 Conventions**
+
+There are no particular conventions that apply to this Recommendation.
+
+# **6 Text alternatives for images**
+
+## **6.1 Uses of text alternatives**
+
+Images are often used to convey a large amount of information, whether it is a diagram for constructing a desk or a photo of what happened at a birthday party. In one glance, a person can retrieve a large amount of information and have a general understanding about the remaining content in the document in which the image resides.
+
+NOTE 1 – While text alternatives are primarily developed for electronic documents (including computer applications, apps, and websites); they can also be helpful in printed documents that can be read out to a user.
+
+Images are sometimes used to supplement or complement the document content or can be another representation of the same content. However, sometimes the image stands alone or adds information that is not part of the other document content. Any information that is present in the image but not the other document content does not get conveyed to those who are unable to see the image. Text alternatives are needed to convey that information.
+
+There are many reasons why a person can need text alternatives, including (but not limited to):
+
+- a) the person has a visual impairment;
+- b) the person is using a program that aurally reads the document content while doing something else (e.g., the person is listening while driving or cooking);
+- c) the device being used to view the image is unable to properly display the image or the image is difficult to see (such as on a small mobile device);
+- d) the person turned off images on their web browser to increase loading speed;
+- e) the person cannot understand and/or interpret the image; and
+- f) the text alternative can be used by search engines to find an image.
+
+Tools (such as screen readers) exist that can read aloud text that appears in a document to those who cannot or are not looking at the screen. If an image can be described and represented textually, then the tools can also read the text alternatives aloud.
+
+NOTE 2 – The term "text alternative" is used to represent the text equivalent of an image, regardless of where that text resides. The term "alternative text" is generally used to represent a text alternative that is technically provided as an attribute of an image.
+
+Text alternatives can include a description of what the image looks like and/or an interpretation of what the image represents or its function. Different text alternatives can be developed for the same image, differing in length and (as a result) information. Technology often allows for a primary alternative text as well as a secondary alternative text to be attached as attributes of an image. Providing both primary alternative text and secondary alternative text can give the user a choice in the amount of detail they wish to receive about an image.
+
+Images can mean different things to different viewers. However, images are added to a document for particular purposes with the intent of meaning certain things to all viewers. In order to write informative text alternatives for an image, it is important to first know the information intended to be represented in the image. It is difficult to share knowledge about an image with others if the alternative text developer does not have knowledge of what the image is intended to convey to the reader. Therefore, it is important to gather or identify as much information as possible about an image.
+
+It is preferable for the developer of the electronic document to also be the developer of text alternatives for images included in the document.
+
+NOTE 3 – While various experts can analyse an image to a greater extent (e.g., for cataloguing purposes in a library of images), it is important that people involved in this procedure understand the information content that the image is intended to convey within the document in which it occurs.
+
+This Recommendation presents a method for identifying information about an image and then structuring text alternatives for the image.
+
+## **6.2 Presenting text alternatives**
+
+### **6.2.1 General**
+
+There are three possible locations for presenting text alternatives for an image:
+
+- a) within the main body of text;
+- b) within the primary alternative text attribute of an image;
+- c) within the secondary alternative text attribute of an image or within secondary alternative text that is linked in some manner to the image.
+
+NOTE – Clause 12.4 provides guidance on the use of these three locations for presenting text alternatives.
+
+### **6.2.2 Text alternatives within the main body of text**
+
+The information contained in well-written text alternatives can often help users who can see an image to understand or interpret the image as it was intended by the document developer. In situations where the information contained in a text alternative is considered beneficial to all (or most) users of a document, this information can be presented in the main body of text, either as part of the main text or in a special addition to the main text that is identified as acting as a text alternative to the image, rather than as alternative text attribute of the image that requires special efforts to access.
+
+Where text alternatives are included within the main body of text, they are not limited in length and can take one or more paragraphs to provide detailed descriptions of the image and detailed discussions of its intended purpose.
+
+### **6.2.3 Primary alternative text**
+
+Primary alternative text is the usual location for text alternatives for images in most documents. The primary alternative text is usually displayed (in a hidden manner) to tools such as screen readers. Some tools present the primary alternative text automatically by default, while the user needs to request the secondary alternative text.
+
+Where alternative text is considered beneficial for all readers it can be placed (with a suitable notation identifying it as alternative text) in the main body of text, as long as the primary alternative text is used to refer to the location of it in the main body of text (see clause 12.4.6).
+
+Some types of electronic documents have a limitation or restriction on the length of the primary alternative text.
+
+NOTE – Some screen readers will sub-divide alternative text entries that are larger than 125 characters.
+
+In order to limit the size of the primary alternative text, it is often viewed as an overview of the image content, what the image is about, or the function of the image.
+
+Short primary alternative texts (due to character length limitations) may not be sufficient to convey the full amount of information provided by the image. Where primary alternative texts are limited in length, secondary alternative text becomes an important means of communicating the complete meaning/content of an image.
+
+### **6.2.4 Secondary alternative text**
+
+Where it is available, secondary alternative text generally does not have limits on its length and therefore can contain a larger amount of information about the image. It can consist of details about the image that could not be part of the primary alternative text.
+
+Since there is no limit on the amount of information, it can include information that some users might not need. The importance of each piece of information about an image can help to determine if the information is presented in the primary alternative text, secondary alternative text, both primary and secondary alternative texts, or not at all (see clause 12 for a discussion of levels of importance).
+
+# **7 Procedure for creating text alternatives**
+
+The creation of suitable text alternatives (regardless of where they are located) shall be based on a thorough understanding of the image, its components, its purpose and context in the document where it is contained.
+
+This can be done by applying the following procedure:
+
+- a) Identify the type of image (clause 8)  
+Identify the type (and if applicable the sub-type) of image.
+
+- b) Identify the purpose of the image (clause 9)
+
+Identify and describe the purpose of each image. This step influences which image components and which pieces of information are important for the user to know.
+
+This involves answering the question "Why?"
+- c) Identify the image components (clause 10)
+
+Depending on the purpose of the image, identify the image components. This step is necessary to properly identify pieces of information about the image that can be important to the user.
+
+This can be done in a two-stage process:
+
+  - 1) Identify the image as a whole;
+  - 2) Identify the image components of the image.
+
+NOTE 1 – Identifying image components is an iterative process. Individual image components can be further separated into a number of (lower level) image components until all components that are important to describe have been identified.
+- d) Identify the information (content) presented by the image (clause 11)
+
+Depending on the purpose of the image, identify the content about an image and its components.
+
+This involves answering the question "What?"
+
+NOTE 2 – "Who" is a specific instance of "What" that involves recognizable people.
+
+NOTE 3 – While identified content is complex, it can become useful to separate that image (or image component) into several (lower level) image components, in order to better be able to identify simpler content components.
+- e) Evaluate the importance of the information about the image (clause 12)
+
+Considering the purpose of the image, evaluate the importance of the identified information about the image to focus on the most important information to present in the text alternative(s).
+
+NOTE 4 – Importance is based on the need of users to know information about the image and is related to the purpose of the image (or image component) and context in which the image is presented. Different information becomes important depending on the purpose of the image and the environment or context of the image.
+
+NOTE 5 – This can help to eliminate less important information and to identify if the information already obtained is sufficiently important to satisfy the purpose.
+- f) Compose the text alternatives (clause 13)
+
+Organize the important information to improve its readability and allocate to the primary or secondary alternative texts of an image and/or to the main text.
+
+NOTE 6 – Organization involves both structuring and writing text alternatives.
+- g) Evaluate the text alternative (clause 14)
+
+Evaluate potential text alternatives (by someone other than the person who created it) to check that it suitably describes the image within the context of the document within which it is contained.
+
+NOTE 7 – While it is ideal for this to involve actual user testing, it is important that this step not be omitted due to lack of available users or other resources.
+
+NOTE 8 – Evaluation by a colleague or friend is better than no external evaluation at all.
+
+# 8 Identifying the types of image
+
+## 8.1 General
+
+Identifying the type of an image provides a quick impression regarding the purpose and possible contents of the image. People looking at an image use this information to give them a "first impression" of what to look for when looking at the image.
+
+NOTE – While there are many additional types and sub-types that could be identified, beyond those in this clause, it is important not to make the identification of types too complex for the users to understand. More detailed types and sub-types are primarily important to those users who will recognize the distinction that the type or sub-type conveys.
+
+## 8.2 Drawings
+
+A drawing is an image created as an original work through the artistic actions of a human. Because it is an artistic creation, even the most realistic of drawings will be influenced by the style and intent of the human creating them.
+
+NOTE – Drawings can be realistic, abstract/non-representational and can contain realistic, abstract/non-representational components.
+
+Drawings can be divided into various sub-types, including:
+
+- a) Realistic drawings, where the content of the image is perceived by the user to faithfully represent data, information, objects, relationships, and/or concepts in the natural world;
+- b) Sketches, where the content was a rapidly executed freehand drawing and is not usually intended as a finished, fully-realistic work;
+- c) Caricatures, where the content shows the features of its subject in a simplified or exaggerated way;
+- d) Abstract drawings, where content of the image is intended to present important major data, information, object, relationship, and/or conceptual components, without representing them as they occur in the natural world;
+- e) Non-representational drawings, where the content of the image is intended for decorative purposes without the intent to represent any particular natural world data, information, objects, relationships, and/or concepts.
+
+## 8.3 Photographs
+
+A photograph is an electronic copy of an image of something that has its own independent existence in the real world. As such, photographs are expected to be realistic representations of the real world.
+
+NOTE – This is not to say that the real world could not be manipulated for purposes of "staging" a photograph to show a particular scene.
+
+While the photograph is a true rendering of the object(s) that it illustrates, those objects can themselves be realistic, abstract, or even non-representational.
+
+While most photographs do not need to be further distinguished by sub-typing, it is important to recognize that a photograph, which has been modified from the real-world scene that it was an image of, is a modified photograph (rather than just considering it as a photograph).
+
+## 8.4 Diagrams
+
+A diagram is an image containing a graphical representation of a set of (physical, logical, conceptual or other) objects or components and their (physical, logical, sequential or other) relationships.
+
+There are a wide variety of sub-types of diagrams, and often many variations on many of these sub-types. Some sub-types of diagrams include: activity diagrams, assembly diagrams, block diagrams, class diagrams, component diagrams, concept diagrams, entity-relationship diagrams, flow
+
+diagrams, graphs, interaction diagrams, logic diagrams, object diagrams, state transition diagrams, structure diagrams and use case diagrams.
+
+When choosing the name of a sub-type to use in alternative text, it is important that the chosen name be meaningful to the intended users.
+
+It is generally more important to describe the intended information content (semantics) of a diagram than the physical characteristics (syntax) of the diagram.
+
+## **8.5 Maps**
+
+A map is an image containing a geospatial representation of geographic data.
+
+NOTE 1 – While a map could be considered as a sub-type of a diagram, the concept and use of a map is so well established that it is useful to consider maps as a separate type of image.
+
+Maps can be presented in two or three dimensions and can contain information on two or three dimensions.
+
+While there are many characteristics that could be used to distinguish between (to sub-type) maps, the most important characteristic to use in identifying a map is to identify the physical area that is the subject of the map.
+
+NOTE 2 – Other characteristics often belong as part of the purpose of the map.
+
+In addition to representing physical areas, some interactive "maps" are used to present users with a choice of different options, contained in various adjacent physical areas.
+
+## **8.6 Computer-generated illustrations**
+
+A computer-generated illustration is an image created by a computer based on data that it has available to it. Because it is created based on data, the permanence of the image is not guaranteed. Changes to the data could result in a different image being created at a future point in time.
+
+NOTE – Drawings created by humans utilizing computerized tools (including computer renditions of drawings) are not considered computer-generated illustrations.
+
+Computers can generate a wide range of images, including diagrams, maps, and images that appear similar to drawings or photographs.
+
+## **8.7 Composite images**
+
+A composite image is an image created by combining individual images or components of individual images.
+
+Composite images can be created by humans or by computers, based on a variety of individual images that could each be created by a human or by a computer.
+
+The main distinction in composite images is whether or not the individual component images can be separately addressed, and thus have their own separate text alternatives.
+
+- a) If the components cannot be separately addressed, then the image behaves as a single image, with a type of composite image and (if needed) multiple sub-types identifying the type (and, if applicable, sub-type) of each of the components.
+- b) If the components can be separately addressed, then the important issue is whether or not the complete composite image also has its own text alternative. If it does not, then information about the membership of the individual component images in the composite image can be important in the text alternatives of each of the components.
+
+## **8.8 Identifying image type in text alternatives**
+
+### **8.8.1 Identifying the image type of single images**
+
+The type (and, if applicable, sub-type(s)) of the image should be identified by a word or a short phrase at the start of the text alternative.
+
+**NOTE 1** – This is typically done in combination with the statement of the purpose of the image (see clause 9.6).
+
+**NOTE 2** – The type of image is not typically important for images that are used to label other information (see clause II.1.4).
+
+### **8.8.2 Identifying image type of composite images with separately addressable components**
+
+- a) If a composite image has separate text alternatives for the entire image and for component images, then the type (and, if applicable, sub-type) of the composite image and each of the separately addressable component images should be identified by a word or a short phrase at the start of the appropriate text alternatives.
+- b) If a composite image only has text alternatives for each of its component images and it is not possible to add a text alternative for the composite image as a whole:
+  - 1) An initial invisible component image should be added to the set of component images, as the first image in the set, so that it can be a source for an alternative text for the entire composite image;
+  - 2) The type (and, if applicable, sub-type(s)) of each component image (including the component image representing the entire composite image) should be identified by a word or a short phrase at the start of the appropriate text alternatives.
+
+# **9 Identifying the purpose of the image**
+
+## **9.1 Introduction to purposes**
+
+A purpose identifies "why" an image is being presented as part of a document. It often identifies the function that the image serves within the document.
+
+**NOTE 1** – Text alternatives are context dependent and thus are different from information used for cataloguing of images within an image library.
+
+Along with information on the type of image, information on the purpose of the image is important in letting a person know whether or not to read the entire text alternative.
+
+The image was chosen to be in the document for one or more reasons (purposes). It is important that the intent of the document developer had for choosing the image is achieved by the text alternative.
+
+**NOTE 2** – The context in which the image is used can help to understand the purpose of an image, especially when this is explained in the main text reference to the image.
+
+The purpose and context of the image will also affect the understanding of the document. An image can have an effect on the understanding of the document content in two manners:
+
+- 1) Objective information can influence intellectual or knowledge-based understanding. Objective information is factual and/or logical.  
+**EXAMPLE 1** – In a bar chart, the statistical data and axis information are objective information.
+- 2) Subjective information can influence affective or emotional-based understanding. Subjective information consists of emotions, concepts, opinions, and judgments that are not necessarily universally shared.  
+**EXAMPLE 2** – Different cultural interpretations of symbolisms in a painting are subjective information.
+
+Purposes can be classified in terms of:
+
+- informative purposes;
+- control purposes;
+- decorative purposes;
+- formatting purposes.
+
+NOTE 3 – While it is important to identify the purpose or purposes of an image, it is usually not productive to try and identify the purposes of individual components of an image. Information on the components of an image belongs in the main content of the text alternative (see clause 11).
+
+## **9.2 Informative purposes**
+
+Most images are intended to provide information to the user that supplements, and/or provides an example of content that is also presented textually, usually within the same document.
+
+NOTE – While an image can seem to duplicate information presented in the main text, it is important to consider what additional information it can be providing, including alternative approaches to understanding the information.
+
+Images used primarily for informative purposes generally contain some information that is important for the user to receive, beyond the purpose for which the image was presented.
+
+## **9.3 Control purposes**
+
+Images are often used as the basis for developing controls.
+
+NOTE – Images can be used with/as controls such as buttons, sliders, knobs, icons and links.
+
+EXAMPLE 1 – An image is used as the target for a hyperlink.
+
+EXAMPLE 2 – Various areas on a map are used as the boundaries for links that take the user to detailed information relating to that area.
+
+The ability to associate text alternatives with these images depends on how they are implemented. In cases where the images are separately addressable from the controls, it is both possible and useful to provide suitable text alternatives.
+
+## **9.4 Decorative purposes**
+
+### **9.4.1 Decorative images that convey affective information**
+
+Decorative images are often ignored by creators of text alternatives. However, this can result in failure to provide screen reader users with important information.
+
+The use of images for decorative purposes can be intended to add visual appeal to a document. This visual appeal can be important in attracting and retaining the attention of users to a document.
+
+"Decorative" images are often used to present emotional and subjective information and thus are also presented for informative purposes (see clause 9.2). If text alternatives are not used for such images, screen reader users are deprived of getting the same information that is provided visually.
+
+EXAMPLE – Where a decorative image is intended to convey humour, not providing a suitable text alternative will fail to convey the intended result. While the intended meaning can be subtle, it is not meaningless.
+
+### **9.4.2 Decorative images with minimal information value**
+
+The information present in some decorative images is of minimal importance.
+
+Providing text alternatives for such images can create unnecessary work for users of text alternatives.
+
+If a decorative image does not present information with some level of importance (see clause 12.2.5), then the text alternative for that image should be empty.
+
+NOTE 1 – Empty alternative text can be used as a means to deliberately provide no textual image description where text alternatives are not needed or appropriate,
+
+Some situations of where text alternatives may not be needed or appropriate include:
+
+- a) an image that is used only to fill space that otherwise would be empty;
+
+NOTE 2 – Background images composed of colours/textures are often used for the sole role of making webpages appear attractive, without adding any particular meaning to the webpage.
+
+- b) an image that is excessively used where redundant complete text alternatives for each usage would provide a hindrance to the user.
+
+NOTE 3 – A corporate logo is used instead of standard bullets to precede items in a list. The items in the list can also be recognized as items in the list from their formatting, and thus knowledge of the existence of the bullets (or images used to replace standard bullets) does not provide any additional information on formatting. Furthermore, repeatedly providing the same text alternatives for each of these bullets could become annoying to screen reader users.
+
+NOTE 4 – This is different from the single use of a logo on each page of a document or system where it is important to at least acknowledge that the image is the corporate logo.
+
+NOTE 5 – It is best to analyse all images according to the procedure in clause 12 and to allow the importance level of descriptive information to determine whether or not text alternatives are needed.
+
+## **9.5 Formatting purposes**
+
+Formatting organizes, separates, and/or highlights some information to distinguish it from other information.
+
+Mark-up languages, such as Hypertext Markup Language (HTML) and Standard Generalized Markup Language (SGML), provide explicit means for formatting text entries. If they are properly used, the addition of images, such as horizontal line separators, only provides additional redundant formatting.
+
+NOTE 1 – Empty alternative text can be used as a means to deliberately provide no textual image description for images that are only used for formatting purposes.
+
+NOTE 2 – While developers often fail to provide text alternatives for images used for formatting, the use of such images instead of or in addition to standard formatting methods often is also done for decorating the document (see clause 8.2.4).
+
+NOTE 3 – Even if an image used for formatting has multiple image components, these components are not significant or useful in describing the purpose of the image for formatting.
+
+NOTE 4 – The existence of components used for formatting within an image can appear to have some importance. However, this can be described focusing on the relationship between the components, without needing to describe the means of formatting used, unless they also fulfil some other purpose in the image.
+
+## **9.6 Identifying purpose in text alternatives**
+
+### **9.6.1 Describing the purpose**
+
+While the purpose of the image can be considered in terms of four general classifications (informative, control, decorative, formatting), the text alternative should (implicitly or explicitly) identify the specific purpose of the image instead of just naming a general classification of purpose.
+
+EXAMPLE – Rather than just stating that the image is "informative", the first sentence of the primary alternative text for an image is "Figure 3 is a flowchart that illustrates the process for (name of the process)."
+
+### **9.6.2 Stating the purpose briefly**
+
+It is important that statements of purpose help the reader to quickly decide whether or not to read the rest of the text alternative.
+
+Where statements of purpose are included in a text alternative, they should be briefly stated in the first sentence of the text alternative.
+
+NOTE 1 – Further details about the purpose (within a text alternative) are provided by identifying the content and identifying qualifications and relationships to the content.
+
+NOTE 2 – Where the purpose of an image of a person is to put a human face to the discussion, the purpose in the text alternative can be simplified to stating that image is a photo or drawing of (name of the person).
+
+EXAMPLE – The text alternative for an image without a caption starts with the sentence, "This (image) is a photo of Albert Einstein."
+
+### **9.6.3 Avoiding redundancy with captions**
+
+Some images are accompanied with a caption that provides a brief statement of its purpose. In such cases, repeating the statement of purpose (and especially repeating the caption) in text alternatives is not helpful.
+
+- a) If a caption is associated with an image, and it provides a suitable statement of the purpose of the image, text alternative should not restate the purpose.
+
+NOTE 1 – Within HTML 5.2 it is possible to use the caption as part of the text alternative.
+
+- b) If a caption is not associated with an image, either a caption should be added to the document containing the image or the text alternative for the image should identify the purpose at the start of the text alternative.
+
+NOTE 2 – This statement of purpose could be worded in a manner that would make a suitable caption for the image.
+
+### **9.6.4 Considering the context of use**
+
+Where appropriate, a brief reference to the context of use of the image may be included as part of the identification of the purpose of an image.
+
+### **9.6.5 Considering both objective and subjective purposes**
+
+It is important that statements of purpose recognize both objective and subjective purposes.
+
+If the purpose of the image includes presenting subjective/emotional/motivational information, then this aspect of the purpose should be described in text alternative.
+
+### **9.6.6 Text alternatives for images used for formatting purposes**
+
+It is not necessary to provide text alternatives to describe the use of images solely for formatting purposes, provided that the formatting information is otherwise provided to the user textually or through markup.
+
+- a) Simple, non-decorative graphic elements (e.g., blanks or lines) to separate or format other content should not be implemented as images so that they will not have text alternatives.
+
+NOTE – Blanks, lines, and other simple graphic elements can be implemented using text.
+
+- b) Where text alternatives are provided to describe images that are used solely for formatting purposes, the text alternative should be described as simply as possible, merely identifying the purpose of the image, without the need for identifying the type of image or describing the contents of the image.
+
+EXAMPLE 1 – Text alternatives for a border between two sections of a form states, "Separation between personal information and product information".
+
+- c) Where decorative images are used for formatting, a text alternative should be provided to describe the image, similar to text alternatives for other decorative images,
+
+EXAMPLE 2 – Fancy borders are used instead of spaces to visually highlight the separation of different chunks of content on a webpage. While these borders do not provide any significant content, the distinction between the different chunks of content is primarily provided by the proper use of headings. However, these fancy borders have a second purpose in that they are also used for decorating the webpage.
+
+### **9.6.7 Further information for images used for informative purposes**
+
+Where an image is presented for informative or control purposes, it is important to provide additional information in the text alternative beyond just identifying the type of image and its purpose(s).
+
+Where an image is presented for informative purposes, the text alternative shall also include an identification of the important components and information presented by the image.
+
+### **9.6.8 Further information for images used for control purposes**
+
+Where an image is used in conjunction with control purposes, the text alternatives shall provide information about its relationship to its associated control(s).
+
+# **10 Identifying the image components**
+
+## **10.1 Images and image components**
+
+The complexity and structure of an image will determine the complexity and structure of appropriate text alternatives. Many images present some levels of complexity that can affect the experience that a viewer of the image is intended to have. Ignoring this complexity can often result in text alternatives that are not a full alternative to the image.
+
+Many images can be broken down into image components where a number of image components can present additional important information to the user. Most image components represent real or logical objects.
+
+EXAMPLE – Each person, object, shape, text, landmark, or step in a process can be considered an image component.
+
+Where the background or border of an image is important, they can be considered as additional image components.
+
+Whether or not a component is identified and elaborated upon depends on how important information about the component is with respect to the purpose and context of the image.
+
+## **10.2 Text components**
+
+It is not appropriate to use an image to present only text that could be otherwise presented as a text element within the document within which it is contained.
+
+EXAMPLE 1 – Where stylized text is desired, it is preferable to accomplish this stylization using (fancy) fonts rather than by using an image of stylized text.
+
+However, there are many instances of images that contain textual components.
+
+EXAMPLE 2 – Where showing a page from a particular book is involved, it is often more appropriate to use an image of the page than to recreate the page using formatted text.
+
+## **10.3 Uniquely identifying image components**
+
+Where multiple components are involved, it is important that each component is uniquely identified so that it is meaningful to the reader of the text alternative. This can help to identify information unique to the component and to identify relationships with other components.
+
+The type of an image component is often very important in understanding its role within an image.
+
+In many cases, an image component can be uniquely identified by referring to it using a generic type of object as its name.
+
+EXAMPLE 1 – Some examples of components identified using a generic type include: a man, a baseball player, a car, a building, a table, a tower.
+
+NOTE 1 – Generic types of components generally involve only general everyday knowledge available to a user. They do not deal with specific branding or specific naming of an object within the image.
+
+In some cases, it is possible to uniquely identify an image component with a specific name that provides further meaning to the image component.
+
+EXAMPLE 2 – Some examples of image components identified using a specific name include: Alan Turing, Babe Ruth, the Batmobile.
+
+In some cases, a specific identifier is created by adding a specific name to a generic type. These qualifications are usually made because of their being readily identifiable.
+
+EXAMPLE 3 – Some examples of image components identified with a qualified type include: King Arthur's round table, the Eiffel tower.
+
+Where multiple image components are of a common type, it is important to uniquely identify each image component in a manner that distinguishes them from other instances of similar objects while recognizing their similarities. This can be accomplished using both a specific name and a generic type.
+
+EXAMPLE 4 – An entity relationship diagram contains image components including: a museum entity, an artistic work entity, an exhibition entity, and various named relationships.
+
+In addition to graphical objects appearing in an image (or image component), textual objects sometimes also appear. Where the text is readable, it can be considered to be specific content that is to be identified in the primary alternative text of an image.
+
+EXAMPLE 5 – A picture of a highway includes a road sign that indicates that Saskatoon is 30 km further down the highway.
+
+Identifying an image component typically does not interpret the meaning of these objects beyond identifying them, unless these components are intentionally being used symbolically.
+
+## **10.4 Structuring information about images and their components**
+
+To gather as much information as possible, it is important for an image first to be considered as a whole entity before then considering components of the image. Some information can be present only when the image is viewed as a whole.
+
+NOTE – In an image with multiple components, the components can be considered individually or as a set of components.
+
+Because an image can have a vast amount of information, some images can be further analysed by identifying several parts (called image components) and then identifying information about each part (or image component). Breaking down the image into several parts allows for focus on the details of those particular parts, resulting in more information about the image. An image component could be broken down further into additional image components, if needed.
+
+[This paragraph contains a *long version of alternative text for Figure 1 suitable for inclusion in main text*] Figure 1 provides a structure diagram of information that can be used to describe an image. In it, there is information about the whole image and also information about various image components. This structure recognizes that different images can have different numbers of image components. There are also relationships between each of the image components and the whole image, which imply that information about the whole image is more important than information about the image components. Information for whole image includes: the image's type, the image's purpose, and information on the content of the whole image. Information about each image component includes: an identifier of the component and information about the content.
+
+![Figure 1: Structure of image information. A hierarchical diagram showing 'Whole image' at the top, branching into 'Image component 1', 'Image component 2', and 'Image component n'. Each box lists its sub-elements: 'Whole image' (Image type, Image purpose, Image content) and each component (Component identifier, Component content).](c5452f95f3b28f1bfe29e84fbc2e1267_img.jpg)
+
+```
+
+graph TD
+    WI["Whole image  
+– Image type  
+– Image purpose  
+– Image content"]
+    IC1["Image component 1  
+– Component identifier  
+– Component content"]
+    IC2["Image component 2  
+– Component identifier  
+– Component content"]
+    ICn["Image component n  
+– Component identifier  
+– Component content"]
+    WI --- IC1
+    WI --- IC2
+    WI --- ICn
+  
+```
+
+T.701.11(20)\_F01
+
+Figure 1: Structure of image information. A hierarchical diagram showing 'Whole image' at the top, branching into 'Image component 1', 'Image component 2', and 'Image component n'. Each box lists its sub-elements: 'Whole image' (Image type, Image purpose, Image content) and each component (Component identifier, Component content).
+
+**Figure 1 – Structure of image information**
+
+A much shorter version of the text alternative for **Figure 1** (to meet character length limitations of text alternatives stored as an attribute of the image and designed for screen reader access) could be:
+
+**Figure 1** provides a structure diagram for a whole image (WI) and its image components (IC). Information about WI includes: a type, the purpose, and information about the content. Information about each of the ICs includes: an identifier and information about the content.
+
+This is a structure for use in identifying information and not for wording the resulting text alternatives. It is recognized that some of the same information can appear multiple times. The intent of this structure is to identify as much information about an image as possible. Redundancies can be resolved in the organizing and writing of the text alternatives (see clause 13).
+
+EXAMPLE – A piece of information identified at the whole image level could be identified again at the image component level or it could be identified as part of multiple image components. It is not necessary for the information to be unique.
+
+NOTE 2 – While it is important to identify all of this information, size constraints and the importance of the information will then be used to decide which elements of information are included in the actual text alternatives.
+
+## **10.5 Dealing with image complexity**
+
+### **10.5.1 Use of image components**
+
+Components of images should be identified and analysed, whenever this helps to identify important information.
+
+### **10.5.2 Textual information in images**
+
+The treatment of text within an image depends on whether or not a typical reader viewing the image would be able to read the text.
+
+- a) Each separate instance of text, which is in the language of the main body of text, within an image should be considered as a separate component of the image, so that its importance is considered in its treatment within the alternative text of the image.
+- b) Text that is blurred or in a different language from the language of the main body of text should be treated as information about the image component in which it occurs.
+
+NOTE – It is sufficient for the text alternative to acknowledge that there is blurred text or that there is text that appears in a foreign language. If knowledge of the foreign language is relevant to understanding the image, the name of the foreign language can be specified.
+
+### **10.5.3 Information about whole images**
+
+Information to be gathered in the development of text alternatives for whole images should include:
+
+- a) the image type;
+
+- b) the image purpose;
+- c) information about the content of the whole image;
+- d) information about the image components.
+
+### **10.5.4 Information about image components**
+
+Information to be gathered in the development of text alternatives for image components should include:
+
+- a) a unique identifier for the image component;
+- b) information about the content of the image component.
+
+# **11 Identifying the information (content) presented by the image**
+
+## **11.1 Content of an image or its components**
+
+The content of an image includes all the pieces of information about the image that satisfies the purpose of including the image in the document.
+
+There are four main types of content:
+
+- a) Subjective content – provides information about how to interpret the rest of the content (see clause 11.2).
+- b) Objective content – provides factual information regarding what is obvious in the image (see clause 11.3).
+- c) Relationship content – provides information on how the image or image component relates to the document and/or other components (see clause 11.4).
+- d) Interaction content – provides information on any interactions associated with an image component (see clause 11.5).
+
+The identification of this content is intended to provide the main information out of which text alternatives can be constructed. It focuses on "what" and "who" is in the image and "what" this should mean to the reader.
+
+Where applicable to the type or intended purpose of the image, this information can be elaborated on in various manners.
+
+## **11.2 Subjective content**
+
+Subjective content describes the (affective) meaning of the image (or image component). Identifying subjective content involves interpreting the intended meaning of the image. Subjective content can include concepts, theories, symbolic meanings, intended emotions, opinions, judgments, and other explanations that go beyond factually identifying individual components and obvious relationships.
+
+NOTE 1 – A description of the subjective content of an image is different from a statement of purpose of an image. The subjective content identifies the meaning of the image or image component while a purpose identifies why the image was presented (see clause 9).
+
+The following questions can be considered in analysing the subjective information presented by images (or image components):
+
+- a) What concepts are associated with the image or the image component?
+- b) What is the image or image component representing or symbolizing?
+- c) If the colour(s) of the image or image component is symbolic, what is the colour(s) representing?
+- d) What themes are represented?
+- e) What emotions are being expressed?
+
+- f) How is the user expected to respond emotionally (with feelings, judgments and opinions) to the image?
+- g) What other subjective information is important for users to know?
+
+NOTE 2 – These questions are best answered by the person who placed the image in the electronic document. If that person is not available to answer these questions, creating the text alternative will involve making informed personal judgements to answer these questions.
+
+## 11.3 Objective content
+
+Objective content presents (cognitive) facts that describe the image (or image component).
+
+It is usually preferable to identify images (or image components) as specifically as possible when analysing an image. Decisions will later be made regarding the importance of including this information in text alternatives (see clause 12) and how to organize the information (see clause 13).
+
+The following questions can be considered in analysing the objective information presented by images (or image components):
+
+- a) "What are the characteristics of the image (or image component)?"
+  - 1) Is there textual content that needs to be known?
+  - 2) Are there characteristics of physical objects that need to be known?
+  - 3) Is there information about a person in the image that needs to be known?
+  - 4) Are there perceptual properties of objects or persons that need to be known?
+  - 5) Are there artistic characteristics that need to be known?
+  - 6) Are there quantities that need to be known?
+- b) "Where is the setting of the image?"  
+NOTE 1 – See also clause 11.4.5 for further considerations relating to physical (spatial) relationships of images and image components.
+- c) "When does the image take place/represent?"
+  - 1) Does the time period need to be known?
+  - 2) Are states involved or changing that need to be known?NOTE 2 – See also clause 11.4.4 for further considerations relating to temporal relationships of images and image components.
+
+Depending on the image, its purpose and context, further elaboration of these questions can be important.
+
+NOTE 3 – Appendix I discusses possible elaborations to some of these questions in detail. Appendix II discusses further considerations related to particular types of images.
+
+## 11.4 Relationship content
+
+### 11.4.1 Relationships
+
+In addition to identifying images (and their components), it is important to identify relationships between images (and their components), both with each other and with the document in which they are displayed.
+
+For images with multiple image components, the relationships between those components can be essential to the understanding of the image. Relationships are especially important for diagram type images.
+
+Relationships are more complex and more diverse than merely answering "What relationships occur?" The relationships that are important to be considered and described are those that provide an
+
+understanding that support the purpose of the image. It is important to consider the various types of relationships that can be illustrated in an image.
+
+Relationships can be categorized into:
+
+- a) actions;
+- b) logical relationships;
+- c) temporal relationships;
+- d) physical (spatial) relationships.
+
+### **11.4.2 Actions**
+
+Actions identify what is happening in an image with respect to one or more image components.
+
+NOTE – Actions include instantaneous events and longer-term activities.
+
+EXAMPLE 1 – A person is running.
+
+EXAMPLE 2 – A child is throwing a ball.
+
+EXAMPLE 3 – A car is driving down the road towards the city.
+
+Actions can be described in general or specific terms.
+
+Generic actions involve only general everyday knowledge available to a user.
+
+EXAMPLE 4 – Some examples of generic actions include: skipping, cutting, chopping.
+
+A generic action can be qualified in a manner that elaborates on it or that distinguishes it from other instances of similar actions.
+
+EXAMPLE 5 – The action of jumping can be qualified as: jumping over hurdles at 8.5 m/s.
+
+EXAMPLE 6 – The car drove around the puddle, rather than through it.
+
+The following questions can be considered in analysing the relationships presented by images (or image components):
+
+- a) What interaction or action is taking place in the image?
+- b) What or who is performing the action in the image?
+- c) What or who is the object of the action in the image?
+- d) How is the action being performed in the image?
+- e) What is the expected result of the action in the image?
+- f) What other information about the action in the image is important for users to know?
+
+### **11.4.3 Logical relationships**
+
+Logical relationships explain how some element(s) (e.g., an image or image component) interact(s) with some other element(s).
+
+EXAMPLE 1 – Entity relationship diagrams and class diagrams illustrate different logical relationships between various (entity or class) components.
+
+Logical relationships are often referred to by more specific terms that name the type of relationship.
+
+NOTE – Some specific types of logical relationships include: associations, flows, parts, instances, responsibility and/or authority.
+
+EXAMPLE 2 – The student has a book.
+
+EXAMPLE 3 – Exhibitions are held at a museum.
+
+EXAMPLE 4 – Part A (the seat) is connected to the bicycle at location F.
+
+EXAMPLE 5 – The customer order includes the name of the customer and the items being ordered.
+
+While it is usual that both the subject and the object will be a part of the image being described, it is possible that either the subject or the object will only be implied. Where the image makes such an implication, it is important that the text alternatives make the user aware of this being implied.
+
+EXAMPLE 6 – The sailor is scanning the horizon. It is implied that he is looking for land. This relationship could be stated as, "The sailor is scanning the horizon looking for land" if the implication is valid (as opposed to looking for other ships or the weather). Otherwise it would be more suitable to state the relationship without mentioning an object, just as, "The sailor is scanning the horizon."
+
+### 11.4.4 Temporal relationships
+
+Temporal relationships explain when some action occurs or the time in which an entity occurs.
+
+NOTE 1 – This is a different use of time from just identifying when the image takes place (see clause 11.3).
+
+NOTE 2 – Temporal relationships can be found in many images including images containing: assembly lines (in a factory), assembly diagrams, flow diagrams, and state transition diagrams.
+
+This can include when apparent (or intended) changes to an image (or image component) occurs. It can include providing information on the sequencing of events.
+
+EXAMPLE – Flow diagrams and state transition diagrams illustrate one or more possible temporal sequences and their possible consequences.
+
+Sequential relationships can be:
+
+- linear (where one element leads to a single other element);
+- branching/hierarchical (where one element leads to multiple other elements);
+- cyclical/networked (any element in a set of elements eventually leads to all elements in the set, including itself);
+- sets of one or more of the above.
+
+Individual sequential relationships can be:
+
+- one directional;
+- bidirectional.
+
+The following questions can be considered in analysing the sequential relationships presented by images (or image components):
+
+- a) What is the basis (or purpose) of the sequential relationship?
+- b) What types of sequential relationships are involved (linear, branching, cyclical, one directional, bidirectional)?
+- c) If there is a start and/or end point(s) to the set of relationships, what are the start and/or end point(s)?
+- d) What are the individual steps (components) of the relationship?
+- e) What is a suitable basis (or method) for logically ordering the individual steps (components)?
+- f) How is each step (component) related temporally to the other steps (components)? This can include:
+  - 1) connections to previous and following steps (components);
+  - 2) time involved in individual steps (components) or for the transition between steps (components);
+  - 3) logic (decision or event) involved in moving from one step (component) to another.
+- g) What other information about the sequential relationship is important for users to know?
+
+### 11.4.5 Physical (spatial) relationships
+
+Physical (spatial) relationships explain where an image (or image component) is located in relation to other physically occurring elements in the image or in the document in which the image is positioned.
+
+NOTE 1 – This is different from the setting pictured in the image (see clause 11.3).
+
+NOTE 2 – While physical positioning can be easily identified, it is important to recognize which physical relationship are important and which can be ignored.
+
+EXAMPLE 1 – A photograph shows a physical layout of objects. However, it is important to determine which physical relationships are important to understanding the intended meaning of the photograph.
+
+EXAMPLE 2 – Assembly diagrams and component diagrams illustrate the intended physical relationships between components. Where an image of the side or back of a computer is intended to show the possible inputs and outputs to the computer, knowing the relative locations between a headphone output port and a microphone input port can be important to help users to properly insert the correct cables.
+
+EXAMPLE 3 – Maps focus on the spatial relationships between the components that they illustrate.
+
+The following questions can be considered in analysing the physical (spatial) relationships presented by images (or image components):
+
+- a) Where is the image (or image component) spatially located within the document (or image)?
+
+NOTE 3 – This can be answered in terms of the coordinates of the image (or image component). There are various ways in which coordinates can be expressed based on, such as:
+
+- 1) The coordinates of the top left corner of the image component relative to some other component or to the entire image.
+- 2) The coordinates of the centre of the image component relative to some other component or to the entire image.
+- 3) The coordinates of the top, bottom, left, and right of the image component relative to some other component or to the entire image.
+
+- b) Where (in general) is the image (or image component) located with regards to the object (e.g., document, image, image component) that contains it? (For example, upper left, lower right.)
+
+- c) Where is the image (or image component) relative to other entities (surrounding content, or internal components)?
+
+NOTE 4 – Relative positioning can be used to express various spatial relationships including: above, below, to the right of, to the left of, in front of, behind, touches, crosses, overlaps, contains, within.
+
+## 11.5 Interaction content
+
+It is important to explain what types of actions can be performed on images or their components. Many images and image components are only intended to provide information to the user, without allowing the user to manipulate or otherwise interact with them.
+
+Where interactions with an image or image component are possible, it is important that these interactions be identified both to avoid unintentional activations of these actions and to be able to intentionally activate desired actions.
+
+The following questions can be considered in analysing the intended use of images (or image components):
+
+- a) How is the user supposed to interact with the image (or image component)?
+- b) What action is the user supposed to perform in order to interact with the image (or image component)?
+- c) What is intended to result from interacting with or performing an action on the image (or image component)?
+
+- d) What can go wrong in the interaction with the image (or image component)?
+
+## **11.6 Analysing the information presented by an image**
+
+- a) Depending on the type and purpose of the image, further information about the main content of the image and its components should be analysed. This includes:
+- 1) Subjective content;
+  - 2) Objective content;
+  - 3) Relationship content;
+  - 4) Intended use content.
+- b) Where an elaboration of some main content appears to be useful, this elaboration may be done, prior to evaluating the importance of the content.
+
+# **12 Evaluating the importance of the information about the image**
+
+## **12.1 Importance is context dependent**
+
+The context in which the image is used helps to determine the importance of pieces of information about the image. The same image can be used for different reasons or purposes. Depending on the purpose and context, different pieces of information become important or unimportant. Therefore, different text alternatives (including in the main text and in primary and secondary alternative texts) can be created for a single image.
+
+NOTE 1 – The importance of a piece of information can change when the purpose and/or context of the image changes.
+
+NOTE 2 – In situations where the image presents unique information, this information adds to what is presented in the main body of text. Additional objective, subjective, and relationship information presented in an image is important to the understanding of the document.
+
+NOTE 3 – In situations where the image complements (restates, modifies, elaborates, supplements) the main body of text, the image can also contain information that is not provided in the main body of text. Complimentary objective and subjective information can be important to the understanding of the document. A full understanding of the image can provide a better understanding of the document.
+
+NOTE 4 – In situations where the image adds visual appeal, the image creates or modifies the mood of the document, the information can be focused on the subjective rather than the objective understanding of the document. While images used for visual appeal can have little or no objective information, the subjective information they present can be important to a full understanding of the document.
+
+## **12.2 Importance**
+
+### **12.2.1 Levels of importance**
+
+There are four levels of importance (essential, significant, helpful, and not important).
+
+### **12.2.2 Essential information**
+
+Essential information is necessary to understand the image within the document in which it appears.
+
+Essential information needs to be presented either in the main body of text (when referring to the image) or in the primary alternative text.
+
+NOTE 1 – By placing essential information in the main body of text (when appropriate) it ensures that all users (not just users with screen readers) will have access to this information.
+
+Essential information can have some or all of the following properties:
+
+- It is aimed at the target audience.
+- It needs to be known in order to comprehend the document.
+
+- Most people want/need it most of the time.
+- The user would be confused as to what the document is talking about without this information.
+- Without it, the user has no idea why the image is there or what the image is for.
+- It provides a good first impression of the image.
+- Based on this information, the user will determine if they need/want to know more about it.
+- For the content provider, this is the information that the content provider absolutely wants to tell people about.
+- It provides the essence, purpose, function, or intent of the image.
+- It identifies that the image conflicts with the main body of text and that this conflict is intentional.
+
+NOTE 2 – As more of these properties apply, it is more likely that the information is essential.
+
+NOTE 3 – Both the image type and image purpose are usually essential information. Other information can also be essential, especially when it fulfils more than one of the above properties.
+
+### 12.2.3 Significant information
+
+Significant information provides a comprehensive understanding of the image within the document in which it appears, when such information is desired by the user (based on the user's understanding of the essential information). Significant information satisfies the detailed interests of most users most of the time.
+
+Significant information needs to be presented either in the primary alternative text or in secondary alternative text.
+
+NOTE 1 – The placement of significant information depends on the amount of essential information that is already contained in primary alternative text.
+
+- a) Where all the essential information has been placed in the main body of text, then significant information can usually be placed in the primary alternative text.
+- b) Where a large amount of essential information has been placed in the primary alternative text, then significant information can be better placed in the secondary alternative text to avoid overloading the primary alternative text.
+
+Significant information can have some or all of the following properties:
+
+- It is aimed at the target audience.
+- It gives a more detailed and thorough understanding of the image and/or document.
+- It is information that could be obtained from viewing the image by more than a quick glance.
+- The user needs to know about it while reading the document, in order to understand the document.
+- The user can decide to know more based on the essential information. This information goes into more details about the essential information.
+- Without this information, the user has an idea of what the image is about and the reason the image is there but does not have a detailed understanding about it.
+- This is information that further explains and gives more details on what the content provider wants to tell the users.
+
+NOTE 2 – As more of these properties apply, it is more likely that the information is significant.
+
+### 12.2.4 Helpful information
+
+Helpful information provides more detailed information about the image for those users who wish to further explore or understand the image, beyond its intended role within the document.
+
+Because helpful information is only of interest to some of the users some of the time, it is not appropriate to be placed in the primary alternative text.
+
+Helpful information may be placed in secondary alternative text or in a separate document that is linked from either the main body of text or the primary alternative text.
+
+Helpful information can have some or all of the following properties:
+
+- It provides specific details that can be of interest to some who are the target audience of the document.
+- It is targeted towards very specific audiences (other than the target audience) or a subset of the target audience.
+- It provides the user with a better understanding of the image when the user is not an expert in the topic area or not the target audience of the document.
+- It reassures users that they have not missed something of greater importance.
+- Without this information, the users have a fairly complete understanding of what the document is about but can have some things that they still want to know.
+- It includes different or other possible interpretations of the information being expressed by the image.
+- The content provider uses this information to clarify some things for some people.
+- It includes optional extra information that is seldom wanted or needed but elaborates on what is already there.
+
+NOTE – As more of these properties apply, it is more likely that the information is helpful.
+
+### **12.2.5 Not important information**
+
+Information is not important if it does not help to provide much additional understanding of the image. This can include information that is not appropriate to consider given the context of the image within the document.
+
+Information which is not important is inappropriate to be presented to users either in the main body of text or in text alternatives.
+
+Information that is not important can have some or all of the following properties:
+
+- Very few to no users will want to know or care to know this information.
+- It is rarely helpful.
+- It is not important enough to mention.
+- Without this information, the user knows everything they want or need to know in order to understand the document and/or image.
+- This is information that can result in unintended confusion and does not help users understand what the content provider is saying.
+
+NOTE – As more of these properties apply, it is more likely that the information is not important.
+
+## **12.3 Textual content in images**
+
+Receiving information about text in images is generally important to understanding the content of the image. The manner of making text available will depend on its importance level and the amount of text involved.
+
+- a) Large amounts of text can be too large to fit in the primary alternative text and can be better placed either in the main body of text (if essential or significant) or in secondary alternative text.
+
+- b) Short amounts of text can be placed either in the primary alternative text of an image or, if they are of lesser importance, within the secondary alternative text of an image.
+- c) Portions of text, where some of the text is obscured, can be placed according to their importance.
+
+## **12.4 Using importance to allocate information to text alternatives**
+
+### **12.4.1 Including subjective information in text alternatives**
+
+- a) Where the meaning of an image (or image component) is essential, this meaning shall be included within the main body of text or the primary alternative text of an image.
+- b) Where the meaning of an image (or image component) is significant, this meaning should be included within the main body of text or the alternative text of an image.
+- c) Where the meaning of an image (or image component) is helpful, this meaning may be included within the secondary alternative text of an image.
+
+### **12.4.2 Including objective information in text alternatives**
+
+- a) When it is essential to identify an image (or image component) in terms of objective content, this identification shall be included within the main body of text or the primary alternative text of an image.
+- b) When it is significant to identify an image (or image component) in terms of objective content, this identification should be included within the main body of text or the alternative text of an image.
+- c) When it is helpful to identify an image (or image component) in terms of objective content, this identification may be included within the secondary alternative text of an image.
+
+### **12.4.3 Including relationship information in text alternatives**
+
+- a) Essential information about relationships shall be described within the main body of text or the primary alternative text of an image.
+- b) Significant information about relationships should be described within the main body of text or the alternative appropriate text of an image.
+- c) Helpful information about relationships may be included within the secondary alternative text of an image.
+
+### **12.4.4 Including information on associated activities in text alternatives**
+
+- a) Information on associated activities shall be included in the primary alternative text of an image.
+- b) Where only a single action can be performed, information on this action may be combined with identifying the component as an active component.
+- c) Where multiple actions can be performed, the image component should first be identified as being an active component, and then the various possible actions should be identified.
+
+### **12.4.5 Dealing with large amounts of essential information**
+
+Where there is more essential information than will fit in the available space in the primary alternative text of an image, all of this essential information shall be placed in a text alternative in the main body of text.
+
+### **12.4.6 Placing text alternatives in the main body of text**
+
+Where the text alternative for an image is included within the main body of text:
+
+- a) if the document type allows specifying an image-description relationship in a machine-readable way, this shall be used in addition to the manner specified in b);
+
+EXAMPLE 1 – In HTML 5, the accessible rich Internet applications (ARIA) attributes *aria-describedby* and *aria-details* can be used to indicate such a relationship.
+
+- b) the text alternative shall be preceded by a phrase indicating that it is serving as the text alternative for the image;
+
+NOTE 1 – This explicit phrase is important for conveying the purpose of the text alternative to persons who can otherwise think that this information is redundant with other parts of the main body of text.
+
+EXAMPLE 2 – The text alternative in the main body of text is preceded by, "[The following paragraph provides the text alternative for Figure 3]".
+
+- c) the primary alternative text for the image shall indicate that the text alternative for the image is presented in the main body of text;
+
+EXAMPLE 3 – The primary alternative text for an image is, "The alternative text for this image is in the main body of text, immediately preceding the image".
+
+- d) the text alternative in the main body of text should precede (rather than follow) the image;
+
+NOTE 2 – It is preferable for the text alternative to immediately precede the image, unless formatting considerations make this impractical.
+
+- e) text alternatives shall not be placed in annexes, appendices, or other locations removed at a distance from the image for which they apply.
+
+### **12.4.7 Handling conflicting information**
+
+Text alternatives for an image are intended to inform users of information that the image is communicating. There can be times when the image presents information conflicts with what is presented in the main body of text. The conflicting information could be intentionally or unintentionally presented.
+
+- a) If the conflicting information is intentionally there, then the information should be pointed out and explained as part of the text alternatives or the main body of text. Since the conflicting information was intentionally made available visually, it should also be made visible in text alternatives or the main body of text.
+- b) If the conflicting information is unintentionally there and recognizing this, the decision is made to retain the image despite the conflicting information, then the conflicting information should not be presented in the text alternatives.
+
+# **13 Compose the text alternatives**
+
+## **13.1 Composition**
+
+There is a difference between identifying information about an image and composing suitable alternative text from that information. Once the information has been analysed for its importance and allocated to a particular type of text alternative (main text, primary alternative text, or secondary alternative text), care then needs to be taken to organize and word the information in a manner that works with the main text.
+
+## **13.2 Organizing the information**
+
+### **13.2.1 Eliminating duplications**
+
+The guidance on identifying image components (see clause 10) and identifying the content of images and their components (see clause 11) is intended to help identify all the important (see clause 12) information about an image and its components. In following this guidance, it is possible to identify some information multiple times (which is better than missing some of it).
+
+It is important to remove redundancies when creating text alternatives, in order to make them concise and quick to use.
+
+EXAMPLE – Most relationships are two-directional. Thus, if A is part of B, then B is composed of various parts including A. Only one of these two expressions of the relationship is needed in the text alternative in order to inform the reader.
+
+### **13.2.2 Fitting into the context of use of the image**
+
+An image fits within its context of use. This context of use, especially information presented prior to the image and the caption of the image, can help a user to understand the image. This context of use can be important both to what is said and what is not said in text alternatives.
+
+It can help to identify where the image provides further information and can suggest how to tie this information when presented in a text alternative into the information presented in the main text.
+
+Where a document contains an explanation of an image, or other information that is also presented in the image, this information does not need be repeated within text alternatives, unless the image presents additional information related to it.
+
+NOTE – This is especially relevant if the information is presented in the main text before or near the image.
+
+While this Recommendation does not provide guidance on writing captions, it is important that captions are not repeated word for word in alternative text.
+
+### **13.2.3 Independence of importance from order**
+
+Importance is used for selecting the information to present, but not necessarily the order of presentation. While it is important to identify the type and purpose of an image before elaborating on the image, the order of presenting the rest of the information within a text alternative will depend on its context of use, the flow of the document, the style of the document and needs of conciseness and readability.
+
+## **13.3 Wording text alternatives**
+
+### **13.3.1 Flow with the document content**
+
+It is important that the text alternatives be written in a way that when read it flows with the rest of the document content. Depending on how and where the image is positioned in the document, the text alternatives can be read at different times.
+
+EXAMPLE – A screen reader can begin reading the webpage content about Napoleon's adventures, then reads the text alternatives for the image of Napoleon, and then continues reading the webpage content about Napoleon's adventures. Flow can be improved if the text alternative speaks of this as an image of Napoleon the adventurer rather than just an image of Napoleon.
+
+### **13.3.2 Style**
+
+Since text alternatives are part of a document, it is important that they be worded similar to how the main body of text is worded.
+
+EXAMPLE 1 – Where the main body of text is worded very formally, the text alternatives are also worded formally.
+
+NOTE – Style refers to how something is worded, not what is included in the wording. Thus formal styles, as well as all other styles, can be used to convey both objective and subjective information about an image.
+
+EXAMPLE 2 – Where the main body of text is worded like a story the text alternative is worded in a manner that fits into the story.
+
+### **13.3.3 Conciseness and readability**
+
+While "a picture can be worth a thousand words", it is seldom desirable or appropriate to use nearly that many words to describe a picture in its text alternatives. It is important to get the message stated concisely and readably.
+
+Writing concise and readable text alternatives can be assisted by:
+
+- a) combining ideas with simple, commonly understood words rather than expressing each of them in phrases or sentences;
+- b) introducing jargon and other concepts needed to understand and/or describe the image in the main body of text prior to the image;
+- c) keeping sentences simple, breaking complex ideas into multiple sentences.
+
+If the important information presented by the image is short, there is less need to identify the purpose and type of image. Presenting the simple information is often sufficient.
+
+As the amount of important information presented by an image increases, so does the usefulness of identifying the purpose and/or type of the image before presenting this important information. This will aid the reader in deciding whether to read the remainder of the text alternative or not.
+
+## **13.4 Creating text alternatives**
+
+Once each piece of information has been allocated to the main body of text, the primary alternative text, or secondary alternative text (see clause 12), organizing information into text alternatives should involve:
+
+- 1) removing redundancies within the identified information;
+- 2) composing appropriate wording for the text alternatives;
+- 3) evaluating the text alternatives (see clause 14);
+- 4) iterating these steps until the text alternatives are acceptable.
+
+# **14 Evaluate the text alternative**
+
+## **14.1 The range of evaluation issues**
+
+Text alternatives should be evaluated to ensure that they:
+
+- a) describe the type, purpose and context of the image;
+- b) work with the main body of text.
+
+## **14.2 The range of evaluation methods and testers**
+
+Text alternatives should be evaluated by a range of methods involving different types of testers.
+
+- a) It is preferable that text alternatives within documents be evaluated by vision impaired users. This can determine if the text alternatives provide important information and whether or not the text alternatives flow with the surrounding content. It can also identify further questions about the image that visually impaired users may need to be answered.
+
+NOTE 1 – Since the text alternatives will more frequently be used by visually impaired users, they are the most appropriate people to perform the evaluation.
+
+NOTE 2 – Visually impaired users are not usually to evaluate how completely a text alternative describes the important information of an image.
+
+- b) Where visually impaired users are not available to evaluate the text alternative, sighted users can evaluate text alternatives in the document with the images not visible.
+
+NOTE 3 – Evaluations by users able to see text alternatives for images that they cannot see only approximate the evaluations that would be performed by visually impaired users. Users able to see have different expectations and needs that will influence the results of such evaluations.
+
+EXAMPLE – A webpage, using a text-only web browser or a web browser with images not presented to view the webpage can help a sighted individual experience a web page where text alternatives are needed.
+
+- c) The evaluation of text alternatives by people who can see the image can help determine if the text alternatives truly represent the content of the image and communicate the important information (or identify important information that is missing).
+
+# Appendix I
+
+## Further elaboration of objective content of images
+
+(This appendix does not form an integral part of this Recommendation.)
+
+## I.1 General
+
+This appendix contains considerations that can be applied to the elaboration of a wide variety of images, and is especially relevant to drawings and photographs. Appendix II contains considerations that can be applied to specific types of images.
+
+## I.2 Characteristics of the image or image component
+
+### I.2.1 Elaborating on physical objects
+
+Each object in the image can be considered as an image component. The following questions can be considered in creating text alternatives for images (or image components) involving physical objects:
+
+- a) What does the object represent?
+- b) What is the brand/model/part name (number) of the object?
+
+### I.2.2 Elaborating on people
+
+Each person in the image can be considered as an image component. The following questions can be considered in creating text alternatives for images (or image components) involving people:
+
+- a) Who is the image or image component of?
+- b) What does the person look like? (Age, sex, nationality, hair colour, eye colour, hairstyle, etc.)
+- c) What is the facial expression of the person?
+- d) What is the person doing?
+- e) What position is the person in? (Standing with hands across the chest, for example.)
+- f) What other information about the person is important for users to know?
+
+### I.2.3 Elaborating on perceptual objects or persons
+
+Perceptual content describes the physical appearance of the object.
+
+NOTE – Perceptual content describes low-level perceptual features of an image (or image component), in a manner similar to that possible by basic vision detection systems.
+
+Typical perceptual features include: colour, texture, shape and pattern.
+
+EXAMPLE – Some perceptual features can be expressed as: blue, yellow, blue-green, aqua, smooth, rough, round, square.
+
+Perceptual content does not assign any meanings to any of these features. Meaning belongs within subjective content.
+
+The following questions can be considered in creating text alternatives for the perceptual properties of images (or image components):
+
+- a) What (are) the colour(s) of the image (or image component)?
+- b) What is the shape of the image (or image component)?
+- c) What is/are the size/dimensions of the image (or image component)?
+- d) What is the texture of the image (or image component)?
+- e) How is the image (or image component) positioned? (For example, sideways, angled, and facing left.)
+- f) What other perceptual information is important for users to know?
+
+### **I.2.4 Elaborating on artistic characteristics**
+
+There are various artistic characteristics that can be used to describe an image.
+
+It is generally possible to distinguish between:
+
+- a) a realistic image (or image component);
+- b) an abstract image (or image component);
+- c) a non-realistic image (or image component).
+
+For works of art, it is often important to distinguish the school to which the image belongs (impressionist, surrealist, etc.).
+
+It is sometimes possible to distinguish the source of the image.
+
+### **I.2.5 Elaborating on locations/settings/places**
+
+While locations are also dealt with under "Where", there are situations in which a location is a significant component of an image. In these situations, a location also becomes a "What".
+
+NOTE – It is better to identify redundant information than to miss identifying important information. Redundancies can be eliminated when the actual text alternatives are written.
+
+The following questions can be considered in creating text alternatives for images (image components) involving locations or places:
+
+- a) What is the location, setting or place depicted in the image (or image component)?
+- b) What specific landmarks are visible in the image (or image component)?
+- c) What other information about the location is important for users to know?
+
+### **I.2.6 Elaboration on quantities**
+
+The following questions can be considered in creating text alternatives for images (or image components) with quantitative information (such as charts and graphs):
+
+- a) What is the quantity?
+- b) What is the quantity associated with?/What does the quantity represent?
+- c) What is the unit of the quantity?
+- d) Is the quantity fixed or dynamic?
+- e) What is the precision (or statistical significance) of the quantity?
+- f) What is the trend that can be interpreted from the data?
+- g) What do the axis or axes represent?
+
+NOTE – To present the specific quantitative data, the data can be presented in a table while a summary or analysis of the data can be presented in the form of text alternatives.
+
+## **I.3 Some temporal properties of images or image components**
+
+### **I.3.1 Introduction to temporal properties**
+
+There are two types of temporal properties to consider
+
+- a) Temporal properties that are part of the information that is presented by an image (or image component), including:
+  - 1) time periods;
+  - 2) events.
+- b) Temporal properties relating to changes in an image (or image component) including:
+  - 1) image components which change in order to represent state information;
+
+2) images within slide shows.
+
+NOTE 1 – While moving images are outside the scope of this Recommendation, it is recognized that some information relating to change can apply to the images (or image components) that are within the scope of this Recommendation.
+
+NOTE 2 – While the focus of various temporal properties is "when" something occurs, the wording in the following sub clauses does not always use the word "when".
+
+### **I.3.2 Elaborating about time periods**
+
+An image (or image component) can be readily identifiable with some particular time period(s), such as:
+
+- time of day (e.g., morning, midday, afternoon, evening, night);
+- special days (e.g., holiday celebrations);
+- time of year (e.g., spring, summer, autumn, winter, January);
+- historic period (e.g., the 1960s, the Victorian era, the stone age).
+
+If time period information is readily identifiable regarding an image (or image component), then it is important to be included within the primary or secondary alternative text of an image (or image component) according to its importance level.
+
+### **I.3.3 Elaborating about events/activities**
+
+Events in people's lives are often synonymous to activities and can be related to actions (see clause 11.4.2). An image (or image component) can be readily identifiable with some particular event/activity (e.g., a birthday party, a wedding, a picnic, a baseball game, baking a pizza).
+
+In more scientific terms, events are usually considered to occur instantaneously when something changes. An image (or image component) can be readily identifiable with some particular instantaneous event (e.g., the start or end of a race, the loss of power to some device, an accident).
+
+If information about an event is readily identifiable regarding an image (or image component), then it is important to be included within the primary or secondary alternative text of an image (or image component) according to its importance level.
+
+### **I.3.4 Elaborating on states**
+
+Individual image components can change within an image to provide various types of state related information.
+
+EXAMPLE 1 – Connectivity and power icons are used to demonstrate the signal strength and amount of charge of a system.
+
+EXAMPLE 2 – Images used for links are provided a distinctive border to indicate that the link has already been visited.
+
+EXAMPLE 3 – Images are displayed lighter or greyed in order to indicate that the control associated with the image is not available.
+
+The following questions can be considered in creating text alternatives for images (or image components) involving changes in individual image components:
+
+- a) What different states (values) can occur for the image component?
+- b) How are different states (values) visually represented?
+
+# Appendix II
+
+## Further considerations for particular types of images
+
+(This appendix does not form an integral part of this Recommendation.)
+
+## II.1 Further considerations for particular types of drawings and photographs
+
+### II.1.1 Portraits
+
+Portraits are images that can identify one or more individuals. Portraits are often used to make a name more real and more human. They can provide character and context to help understand the person.
+
+Text alternatives for a portrait can include information on:
+
+- a) the age or age range (child, youth, young adult, adult, senior, etc.) of the person;
+- b) the look on the person's face (serious, relaxed, startled, etc);
+- c) the type/period of clothing worn by the person;
+- d) the background setting (if any);
+- e) any actions the person is involved with;
+- f) any obvious relationships to others in the image.
+
+It is important that text alternatives to a portrait only describe those characteristics of a person that can be visually determined by someone looking at the image and avoid adding other information that is not visually represented in the image.
+
+### II.1.2 Symbolic images
+
+Some images are presented to symbolize concepts rather than the actual components that they are constructed from.
+
+EXAMPLE – An image of a handshake is often used to symbolize trustworthiness, integrity, etc.
+
+When an image is used to symbolize some concept, it is more important that the text alternative focus on the intended concept rather than provide a literal description of the image.
+
+NOTE – In creating text alternatives for symbolic images, one can consider "If I could not use this image, what would I put in its place?" in order to determine appropriate alternative text.
+
+Symbolism can also be used for individual components of an image. Where the symbolism is obvious, it can be important to identify or explain the symbolism. Where symbolism is purely visual (i.e., in the use of symbolic colours) it is more important that the text alternative focus on the intended symbolism rather than provide a visual description of the component.
+
+### II.1.3 Images of text
+
+While images containing only text are generally not appropriate, there can be some circumstances where they are used (an image of a particular document, an image of an actual signature, etc.).
+
+If the text in the image is readable and relevant to the document, it is important to provide a complete transcript of the text in the image.
+
+If the text is not expected to be readable (e.g., blurred, too small, or in a foreign language), it is important to acknowledge that the image contains text and to explain why a complete transcript is not being provided (e.g., blurred, too small, or in a foreign language). It can also be important to elaborate on this acknowledgement (e.g., by identifying the foreign language, if that is not identified in the main text).
+
+### **II.1.4 Images used to label other information**
+
+Various simple images (symbols, emoji's, etc.) can be used as graphic labels for individual pieces of information. In these cases, they typically represent a single word or a simple concept (telephone, happy, etc.).
+
+Where an image represents a single word or a short phrase, it is appropriate that the alternative text be limited to presenting this word or sort phrase.
+
+### **II.1.5 Groups of images conveying a single piece of information**
+
+In some cases, a group of simple images (e.g., stars) are used to convey a single piece of information (e.g., a rating). In this case, it is important to provide information on the group rather than on the individual images (see clause 8.8.2).
+
+### **II.1.6 Icons and other control images**
+
+Icons are user interface symbols representing an object and/or function of the computer system (clause 2.1, [b-ISO/IEC 11581-1]. The main purpose of icons and images used as controls (buttons, links, etc.) is to initiate an action rather than to convey information.
+
+Where an image is used for control purposes, it is appropriate for the alternative text to be limited to identifying the purpose of the control (e.g., print this Recommendation).
+
+### **II.1.7 Images used with a fully descriptive caption**
+
+Some images provide little information beyond what is already contained in their caption. It is not suitable to repeat information in the caption, unless it is being elaborated on with important additional information in the text alternative.
+
+Where the caption provides all the information necessary to fully describe the image, the text alternative can be a simple reference, such as "see caption for text alternative".
+
+### **II.1.8 Images that are fully described in the main text**
+
+While it is important to reduce redundancy, it is also important for readers to be assured that they have not missed something important by not seeing an image. Where the image is used to elicit an emotional response (including by providing "eye candy") there can be important subjective content that the main text is missing (see clause 11.2).
+
+Where an image is fully described in the main text, it is important to identify in the main text that this description also serves as the text alternative for the image (see clause 12.4.6).
+
+## **II.2 Further considerations for diagrams and maps**
+
+### **II.2.1 Assembly, component and similar diagrams**
+
+Images are often used to illustrate a set of physical components and how they physically interconnect. These images can be used for various purposes, including: to understand the workings of a system, to assist in the assembly/disassembly of a system, and to assist in diagnosing problems within the system. In some situations, multiple images can be used provide different views on the same set of components.
+
+The main text that accompanies these types of illustrations often names the components and explains which component connects to which other components. In some instances, a listing of components precedes a step by step listing of assembly/disassembly instructions. This text is often written very compactly with the expectation that the image will provide significant supplemental information, often intended to be used in parallel with this text. Often the main text will refer to set of images that illustrate progressive steps in the assembly/disassembly/operation of the system.
+
+Each image typically goes beyond this text to illustrate physical characteristics of each component and often how these physical characteristics interact to facilitate the connection or operation of different components. The image also typically provides information on the relative positioning of individual components, which can aid in their assembly.
+
+These types of images generally label each component, either with its name or some reference identifier that corresponds to information contained in the main text. In this case it is important not to treat these labels as separate components. However, text or relationship information (beyond the set of physical components) that is inserted in the image for other purposes (e.g., instructions on how to position or connect components or indications of the direction of motion of a component) can still be treated separately from the physical components in the image.
+
+Considerations for the text alternatives for these types of images include:
+
+- a) How the text alternative works with the main text (regardless of where the text alternative is located);  
+NOTE 1 – It is important to remember that the role of the image is often to elaborate the main text, rather than to fully replace it and that the two are presented separately to the user. It is important to focus text alternatives on information not contained in the main text that supports that text, while minimizing duplication.  
+NOTE 2 – It is easier to achieve this working together when the alternative text is created at the same time as the main text and the image.
+- b) How the text alternative will assist the reader in achieving the goals intended for the image (e.g., assisting with assembling a system);  
+NOTE 3 – While this type of image often contains a large amount of information, it is important to evaluate the importance of this information with regards to the intended uses of the image.
+- c) How the text alternative assists in the identification of different components and their important characteristics.  
+NOTE 4 – While physical components can be highly complex, the most important information about an individual component will usually focus on identifying how it is distinct from other components and how it connects to other components.
+
+### **II.2.2 Flow and relationship diagrams**
+
+The relationships found in flow and relationship diagrams are much more important than the actual layout and shape(s) of the objects that they contain.
+
+Most flow and relationship diagrams are configured to easily fit the available space in an image. The actual location of individual components only matters where there are connections between components. This can mean unusual configurations that were chosen to avoid or minimize the flow and relationship lines crossing one another. The location of components is only important if they are presented based on their physical layout in some particular location.
+
+Flow and relationship diagrams often use different shapes to represent different types of components. Rather than describing the shapes of these objects, what is important is to combine the information presented by the shape with the name of the component.
+
+EXAMPLE – Data flow diagrams use different shapes for processes and data stores. Rather than saying that billing takes place in a rectangular block, it is appropriate to refer to this component as the "billing process", since a rectangular block is used to represent a process.
+
+### **II.2.3 Graphs and other representations of numerical data**
+
+In general, the best format for presenting data that is visualized via graphs and other representations of numerical data is a table of values. Tables are especially useful for graphs and other representations of discrete values.
+
+NOTE – While a mathematical formula can be a more accurate representation of some continuous data, it is often more information than would be provided to a person looking at that data when it is visually presented in a graph.
+
+### **II.2.4 Maps and other images with active areas**
+
+Some maps and other images (such as organization charts) contain multiple active components that are often used to provide links to further content. It is important to treat these as composite images with text alternatives both for the overall image and for each active image component (see clause 8.7).
+
+## **II.3 Background images**
+
+It is often not possible to provide alternative text to the background of a webpage or other types of electronic documents.
+
+Where information on a background is needed, it can often only be presented in the main body of text.
+
+# Bibliography
+
+- [b-ISO 32000-1:2008] ISO 32000-1:2008, *Document management – Portable document format – Part 1: PDF 1.7*.
+- [b-ISO/IEC 11581-1] ISO/IEC 11581-1:2000, *Information technology – User system interfaces and symbols – Icon symbols and functions – Part 1: Icons – General*.
+- [b-ISO/IEC 13249-5] ISO/IEC 13249-5:2003, *Information technology – Database languages – SQL multimedia and application packages – Part 5: Still image*.
+- [b-ISO/IEC TS 20071-21] ISO/IEC TS 20071-21:2015, *Information technology – User interface component accessibility – Part 21: Guidance on audio descriptions*.
+- [b-ISO/IEC 20071-23] ISO/IEC 20071-23:2018, *Information technology – User interface component accessibility – Part 23: Visual presentation of audio information (including captions and subtitles)*.
+- [b-ISO/IEC 20071-25] ISO/IEC TS 20071-25:2017, *Information technology – User interface component accessibility – Part 25: Guidance on the audio presentation of text in videos, including captions, subtitles and other on-screen text*.
+- [b-ISO/IEC 40500] ISO/IEC 40500:2012, *Information technology – W3C Web Content Accessibility Guidelines (WCAG) 2.0*.
+- [b-ISO/IEC/IEEE 23026] ISO/IEC/IEEE 23026:2015, *Systems and software engineering – Engineering and management of websites for systems, software, and services information*.
+- [b-ITU H.Sup.17] ITU-T H-Series Supplement 17 (2014) | ISO/IEC Guide 71:2014, *Guide for addressing accessibility in standards*.
+- [b-IDG] Benetech, Diagram Center, *Image Description Guidelines*, <http://diagramcenter.org/table-of-contents-2.html>
+- [b-IGEPUB3] Benetech Diagram Center. *Image Guidelines for EPUB 3*, <http://diagramcenter.org/59-image-guidelines-for-epub-3.html>
+- [b-CB] Defense Visual Information Directorate, *Captioning Basics*, [https://imagery.navy.mil/training/captioning\\_basics.pdf](https://imagery.navy.mil/training/captioning_basics.pdf)
+- [b-Eakins] Eakins J.P., *Retrieval of still images by content*. In: Lectures on information Retrieval, M. Agosti, F. Crestani, and G. Pasi, (Springer L.N.I.C.S.S., ed.). Springer-Verlag New York, New York, NY, Vol. 1980, 2001, pp. 111– 38.
+- [b-Eriksson] Eriksson Y. 1999, *How to make tactile pictures understandable to the blind reader*, [http://www.dinf.ne.jp/doc/english/Us\\_Eu/conf/z19/z19001/z1900116.html](http://www.dinf.ne.jp/doc/english/Us_Eu/conf/z19/z19001/z1900116.html)
+- [b-Heller, Martin] Heller R.S., Martin C.D. *A media taxonomy*. Multimedia, IEEE. 1995 Winter, 2 (4) pp. 36– 45
+- [b-Hunter et al.] Hunter B., Crismore A., Pearson P.D. *Visual Displays in Basal Readers and Social Studies Textbooks*. In: The Psychology of Illustration, Instructional Issues, (Willows D.M., Houghton H.A., eds.). Springer, New York, Vol. 2, 1987, pp. 116– 35.
+- [b-ADI] Digital Media J.I.S.C. *Approaches to Describing Images*, <https://www.webarchive.org.uk/wayback/archive/20141202111117/http://www.jiscdigitalmedia.ac.uk/guide/approaches-to-describing-images>
+
+- [b-Mikovec Z., Slavik] Mikovec Z., Slavik P. 1999. *Perception of pictures without graphical interface*. In Proceedings of the 5th ERCIM Workshop on User Interfaces for All (UI4ALL '99), Dagstuhl, Germany, November-December 1999.
+- [b-Shatford] Shatford S. *Analyzing the Subject of a Picture: A Theoretical Approach*. Cat. Classif. Q. 1986 Spring, 6 (3)
+- [b-Shen et al.] Shen H.T., Ooi B.C., Tan K. (2000), *Giving meanings to WWW images*. In Proceedings of the Eighth ACM international Conference on Multimedia (Marina del Rey, California, United States). MULTIMEDIA '00. ACM, New York, NY, 39-47. DOI <http://doi.acm.org/10.1145/354384.376098>
+- [b-Tang, Carter] Tang L., Carter J. (2011), *Verbalizing images*, in HCII International 2001 – Posters Extended Abstracts, C. Stephanidis (ed.), Comms in Computer and Information Science, Vol. 173, 394-398, Springer, Heidelberg.
+- [b-AUAT] WebAIM, *Appropriate Use of Alternative Text*, <http://www.webaim.org/techniques/alttext/>
+- [b-W3C HTML5.2] World Wide Web Consortium (2017), *W3C Recommendation on HTML 5.2*, <https://www.w3.org/TR/html52/>
+- [b-W3C Tutorials] World Wide Web Consortium, *Web Accessibility Tutorials, Image concepts*, <https://www.w3.org/WAI/tutorials/images/>
+- [b-W3C WAI-ARIA] World Wide Web Consortium (2017), *W3C Recommendation on Accessible Rich Internet Applications (WAI-ARIA) 1.1*, <https://www.w3.org/TR/wai-aria-1.1/>
+
+
+
+## SERIES OF ITU-T RECOMMENDATIONS
+
+|                 |                                                                                                                                                           |
+|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Series A        | Organization of the work of ITU-T                                                                                                                         |
+| Series D        | Tariff and accounting principles and international telecommunication/ICT economic and policy issues                                                       |
+| Series E        | Overall network operation, telephone service, service operation and human factors                                                                         |
+| Series F        | Non-telephone telecommunication services                                                                                                                  |
+| Series G        | Transmission systems and media, digital systems and networks                                                                                              |
+| Series H        | Audiovisual and multimedia systems                                                                                                                        |
+| Series I        | Integrated services digital network                                                                                                                       |
+| Series J        | Cable networks and transmission of television, sound programme and other multimedia signals                                                               |
+| Series K        | Protection against interference                                                                                                                           |
+| Series L        | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant |
+| Series M        | Telecommunication management, including TMN and network maintenance                                                                                       |
+| Series N        | Maintenance: international sound programme and television transmission circuits                                                                           |
+| Series O        | Specifications of measuring equipment                                                                                                                     |
+| Series P        | Telephone transmission quality, telephone installations, local line networks                                                                              |
+| Series Q        | Switching and signalling, and associated measurements and tests                                                                                           |
+| Series R        | Telegraph transmission                                                                                                                                    |
+| Series S        | Telegraph services terminal equipment                                                                                                                     |
+| <b>Series T</b> | <b>Terminals for telematic services</b>                                                                                                                   |
+| Series U        | Telegraph switching                                                                                                                                       |
+| Series V        | Data communication over the telephone network                                                                                                             |
+| Series X        | Data networks, open system communications and security                                                                                                    |
+| Series Y        | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities                               |
+| Series Z        | Languages and general software aspects for telecommunication systems                                                                                      |
\ No newline at end of file
diff --git a/marked/T/T-REC-T.701.21-202203-I_PDF-E/a3dc41dc3df86ea68d266af2bf95cf5b_img.jpg b/marked/T/T-REC-T.701.21-202203-I_PDF-E/a3dc41dc3df86ea68d266af2bf95cf5b_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..94d45ee0d7450a0c276bffad33306ce1ec96de62
--- /dev/null
+++ b/marked/T/T-REC-T.701.21-202203-I_PDF-E/a3dc41dc3df86ea68d266af2bf95cf5b_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:c981deef08fa0ff69264e0a06c61f5dd291a362fb37303b3216e33a0ba5040e9
+size 5841
diff --git a/marked/T/T-REC-T.701.21-202203-I_PDF-E/raw.md b/marked/T/T-REC-T.701.21-202203-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..fbf0f24637ee2f04720281f59c158e01b30f4579
--- /dev/null
+++ b/marked/T/T-REC-T.701.21-202203-I_PDF-E/raw.md
@@ -0,0 +1,1106 @@
+
+
+I n t e r n a t i o n a l   T e l e c o m m u n i c a t i o n   U n i o n
+
+# ITU-T
+
+TELECOMMUNICATION  
+STANDARDIZATION SECTOR  
+OF ITU
+
+# T.701.21
+
+(03/2022)
+
+SERIES T: TERMINALS FOR TELEMATIC SERVICES  
+User interfaces - Accessibility and human factors
+
+# --- Guidance on audio description
+
+Recommendation ITU-T T.701.21
+
+## ITU-T T-SERIES RECOMMENDATIONS TERMINALS FOR TELEMATIC SERVICES
+
+|                                                          |                    |
+|----------------------------------------------------------|--------------------|
+| Facsimile – Framework                                    | T.0–T.19           |
+| Still-image compression – Test charts                    | T.20–T.29          |
+| Facsimile – Group 3 protocols                            | T.30–T.39          |
+| Colour representation                                    | T.40–T.49          |
+| Character coding                                         | T.50–T.59          |
+| Facsimile – Group 4 protocols                            | T.60–T.69          |
+| Telematic services – Framework                           | T.70–T.79          |
+| Still-image compression – JPEG-1, Bi-level and JBIG      | T.80–T.89          |
+| Telematic services – ISDN Terminals and protocols        | T.90–T.99          |
+| Videotext – Framework                                    | T.100–T.109        |
+| Data protocols for multimedia conferencing               | T.120–T.149        |
+| Telewriting                                              | T.150–T.159        |
+| Multimedia and hypermedia framework                      | T.170–T.189        |
+| Cooperative document handling                            | T.190–T.199        |
+| Telematic services – Interworking                        | T.300–T.399        |
+| Open document architecture                               | T.400–T.429        |
+| Document transfer and manipulation                       | T.430–T.449        |
+| Document application profile                             | T.500–T.509        |
+| Communication application profile                        | T.510–T.559        |
+| Telematic services – Equipment characteristics           | T.560–T.619        |
+| General multimedia application frameworks                | T.620–T.649        |
+| <b>User interfaces - Accessibility and human factors</b> | <b>T.700–T.799</b> |
+| Still-image compression – JPEG 2000                      | T.800–T.829        |
+| Still-image compression   JPEG XR                        | T.830–T.849        |
+| Still-image compression – JPEG-1 extensions              | T.850–T.899        |
+
+*For further details, please refer to the list of ITU-T Recommendations.*
+
+# Recommendation ITU-T T.701.21
+
+# Guidance on audio description
+
+## Summary
+
+Audio description is a service or feature of the auditory modality that contains an oral narration with details or context involving situations and scenes found in an audiovisual content (such as recorded video presentations, broadcast television, cinema, live or recorded drama). The primary users of audio description are blind persons or persons with low vision and their friends and family.
+
+Recommendation ITU-T T.701.21 provides guidance to audio description developers and practitioners in creating effective content describing audiovisual material in an auditory-only modality, the style or manner in which audio description is delivered, the audio description script and script time cues, in relation to the original content.
+
+Recommendation ITU-T T.701.21 is twin with the published ISO/IEC TS 20071-21:2015 "Information Technology – User interface component accessibility – Part 21: Guidance on audio description" developed by ISO/IEC JTC1 SC35.
+
+## History
+
+| Edition | Recommendation | Approval   | Study Group | Unique ID*                                                                |
+|---------|----------------|------------|-------------|---------------------------------------------------------------------------|
+| 1.0     | ITU-T T.701.21 | 2022-03-29 | 16          | <a href="http://handle.itu.int/11.1002/1000/14972">11.1002/1000/14972</a> |
+
+## Keywords
+
+Accessibility; audio description.
+
+---
+
+\* To access the Recommendation, type the URL <http://handle.itu.int/> in the address field of your web browser, followed by the Recommendation's unique ID. For example, <http://handle.itu.int/11.1002/1000/11830-en>.
+
+## FOREWORD
+
+The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis.
+
+The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics.
+
+The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1.
+
+In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC.
+
+## NOTE
+
+In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party.
+
+## INTELLECTUAL PROPERTY RIGHTS
+
+ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process.
+
+As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at <http://www.itu.int/ITU-T/ipr/>.
+
+© ITU 2022
+
+All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU.
+
+## Table of Contents
+
+|                                                                     | <b>Page</b> |
+|---------------------------------------------------------------------|-------------|
+| 1 Scope.....                                                        | 1           |
+| 2 References.....                                                   | 1           |
+| 3 Definitions .....                                                 | 2           |
+| 3.1 Terms defined elsewhere.....                                    | 2           |
+| 3.2 Terms defined in this Recommendation.....                       | 2           |
+| 4 Abbreviations and acronyms .....                                  | 4           |
+| 5 Conventions .....                                                 | 4           |
+| 6 Framework and process considerations for audio descriptions ..... | 4           |
+| 6.1 General .....                                                   | 4           |
+| 6.2 Types of audio description .....                                | 5           |
+| 6.3 Creating audio description.....                                 | 6           |
+| 6.4 Live audio description .....                                    | 7           |
+| 6.5 Pre-recorded descriptions .....                                 | 9           |
+| 7 Guidance on audio description .....                               | 9           |
+| 7.1 General considerations .....                                    | 9           |
+| 7.2 Developing an audio description .....                           | 10          |
+| 7.3 Styles of narration.....                                        | 12          |
+| 7.4 Levels of importance .....                                      | 13          |
+| 7.5 General guidance on descriptions.....                           | 15          |
+| 7.6 Guidance on identifying objects.....                            | 15          |
+| 7.7 Guidance on identifying persons .....                           | 16          |
+| 7.8 Guidance on relationships .....                                 | 20          |
+| 7.9 Guidance on parts of speech.....                                | 21          |
+| Bibliography.....                                                   | 22          |
+
+# Introduction
+
+Recommendation ITU-T.701.21 provides audio description (AD) developers and practitioners with guidance in creating effective content describing audiovisual material in an auditory-only modality, the style or manner in which audio description is delivered, the audio description script and script time cues, in relation to the original content. The circumstances to which AD applies include recorded videos, broadcasts and broadband television, cinema, live or recorded dramas, museums and art gallery exhibits, heritage tours, news, and comedies. Some of this content is static and unchanging, some are dynamic, some are expressed in a visual modality alone, and some are in a combination of visual and auditory modalities.
+
+An example of mainstream use of audio description techniques can be found in sports commentaries. It can be enjoyed by diverse audiences and uses personalities, emotional expressions and reactions to content to express qualities of the original content.
+
+Audiovisual material is produced for people who can see and hear. It is also typically produced in a specific language for a particular audience. Translations of the original auditory content and associated audio descriptions can be provided in different languages. Providing audio descriptions and translating them into other languages can be beneficial to diverse users within diverse contexts, including persons who are blind or persons with low vision, persons with learning difficulties or cognitive impairments and in the case of translation, persons who need the content to be in another language. Translating subtitles and other on-screen texts and providing them in auditory forms can also be beneficial.
+
+Producing audio descriptions can be thought of in a similar way to language translation where it involves several kinds of subjective decisions. For example, the use of vocabulary, tone, speed, intonation, and expression. The accuracy and quality that audio describers or script writers can achieve is determined by matching the factors above with the requirements of the original content.
+
+The creation and delivery of audio descriptions based on the guidance in this Recommendation is not intended to interfere with or change the meaning of the original content, freedom of speech and expression, or opinion of rights holders.
+
+Further benefits of providing audio descriptions can be attributed towards raising awareness of barriers experienced by blind persons and persons with low vision and other beneficiaries in accessing audiovisual content. The use of this Recommendation can also help embed universal and inclusive designed media content production practices in educational programmes (such as films, theatre performances, museums and art gallery exhibits and other forms of media).
+
+## **Recommendation ITU-T T.701.21**
+
+## **Guidance on audio description**
+
+# **1 Scope**
+
+This Recommendation provides recommendations for describing audiovisual content in an auditory modality for use in recorded video presentations, broadcast television, cinema, live or recorded dramas, museums and art gallery exhibits, heritage tours, news and comedies, regardless of the language and technology being used to transmit and present the recorded or live audiovisual content.
+
+NOTE 1 – There are many secondary users of audio description but the primary and intended users of audio descriptions are blind persons or persons with low vision and their friends and family.
+
+This Recommendation provides guidance on the subjective nature of creating audio description.
+
+It also provides guidance for audio description developers (script writers, voice narrators, and organizations or groups responsible for delivering audio description) in consistently and accurately representing audiovisual content.
+
+NOTE 2 – It might not always be possible to provide an equivalent experience due to limitations in the amount of time available for an audio description depending on the content being described.
+
+This Recommendation applies to describing audiovisual content and does not consider the devices or transmission mechanisms used to deliver the content or the audio description. These devices include but are not limited to, televisions, computers, wireless devices, projection equipment, digital versatile disk (DVD) and home cinema equipment and other forms of user interface technology. Therefore, this Recommendation does not consider transcoding files for the various video outputs.
+
+NOTE 3 – Technical matters of transmission and distribution are covered by other standards (e.g., motion picture experts group (MPEG) standards and other technical international standards such as [b-IEC 62731]).
+
+This Recommendation provides guidance on how to approach user preferences, available styles, and flexibility in approaches to audio description.
+
+It does not apply to static images contained in electronic documents (see [b-ITU-T T.701.11] for guidance on text alternatives for images).
+
+It applies mainly to auditory presentations intended to be transmitted or delivered simultaneously to the original audiovisual content.
+
+NOTE 4 – Limitations experienced by broadcasters or people in synchronous environments might be reduced online or in asynchronous environments.
+
+ITU-T T.701.21 is a twin text publication with ISO/IEC TS 20071-21:2015, "Information technology – User interface component accessibility – Part 21: Guidance on audio descriptions".
+
+# **2 References**
+
+The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation.
+
+None.
+
+# 3 Definitions
+
+## 3.1 Terms defined elsewhere
+
+None.
+
+## 3.2 Terms defined in this Recommendation
+
+This Recommendation defines the following terms:
+
+### 3.2.1 General terms
+
+**3.2.1.1 audiovisual content:** <audio description> Visual and/or auditory element of recorded video presentations, live performances, or static or dynamic events to which audio description applies.
+
+NOTE 1 – This generic term is used where only the visual modality might apply, for example, in an art gallery or museum exhibits.
+
+NOTE 2 – The range of circumstances to which this term applies includes recorded video presentations, broadcast and broadband television, cinema, live or recorded drama, museum and art gallery exhibits, heritage tours, news, and comedies.
+
+**3.2.1.2 Creative:** <audio description> Creation and addition of new original content to existing content.
+
+**3.2.1.3 genre:** <audio description> Classification of a film, programme, drama, or an event from an artistic perspective.
+
+NOTE 1 – Genres include, but are not limited to, history, action, horror, romance, and comedy.
+
+NOTE 2 – Programme genres are not necessarily mutually exclusive.
+
+**3.2.1.4 harmony:** <audio description> Natural fit between the audio description script and its delivery and the original content.
+
+**3.2.1.5 programme category:** <audio description> Classification of programmes
+
+NOTE 1 – Some programme categories include documentary, news and information, and drama.
+
+NOTE 2 – Programme categories are not necessarily mutually exclusive.
+
+**3.2.1.6 programme:** <audio description> Complete unit of a recorded or live video broadcast.
+
+**3.2.1.7 video (recorded):** <audio description> Combination of auditory and visual content intended to be presented together in a synchronized manner.
+
+### 3.2.2 Audio-specific terms
+
+**3.2.2.1 audio track:** Auditory components of a video other than audio description components.
+
+**3.2.2.2 audio description:** Descriptive audio.
+
+NOTE 1 – Audiovisual content is described in an auditory modality.
+
+NOTE 2 – Audio description can be used to describe sound not easily identified or sound coming from an unknown source or location.
+
+NOTE 3 – Audio description can also be used to describe locations, directions, and objects.
+
+**3.2.2.3 audio introduction:** Complementary auditory content included before the original audiovisual content begins.
+
+**3.2.2.4 basic audio description:** Audio description provided along with the original audiovisual content without lengthening the time of presentation.
+
+**3.2.2.5 extended audio description:** Audio description provided with the original audiovisual content that lengthens the total time of the presentation or event.
+
+### **3.2.3 Language of presentation terms**
+
+**3.2.3.1 original language:** Native language in which audiovisual content is produced.
+
+**3.2.3.2 re-voicing/dubbing/voice-over:** Secondary audio version of a film or video produced by voice talent, translators, and dialogue writers in a language other than the original language of the film or video.
+
+NOTE 1 – When dubbing, this is timed to match the voicing or mouth movements of animated characters or the original actors.
+
+**3.2.3.3 subtitles:** Transcription or translation of the dialogue, suitable for when the sound is available but not understood.
+
+NOTE – Specific guidance on delivering subtitles, on-screen text, and embedded text will be provided in a forthcoming revision to this Recommendation.
+
+**3.2.3.4 spoken subtitles/audio subtitles/spoken captions:** Subtitles on audiovisual content that are read aloud and spoken over the audio in subtitled audiovisual content.
+
+**3.2.3.5 spoken subtitles with audio description:** Audiovisual content which is both subtitled and audio described through the narrator reading the translation after stating that a subtitle appears.
+
+NOTE 1 – Subtitles can also be identified through alternative voicing, synthetic speech, or sound indicators.
+
+NOTE 2 – Spoken subtitles often use a different voice to the voice of the audio describer to avoid confusion between the dialogue and the description.
+
+NOTE 3 – Spoken subtitles and audio descriptions can be available to users separately or together.
+
+NOTE 4 – Spoken subtitles are synchronized with the text on screen.
+
+### **3.2.4 Audio description production terms**
+
+**3.2.4.1 audio describing:** Delivering a script designed to meet the needs of persons wishing to have access to audiovisual content.
+
+**3.2.4.2 co-produced:** <audio description> Produced at the same time as the rest of the audiovisual content.
+
+**3.2.4.3 live production:** Production process that involves creating audio descriptions in real time along with the creation and delivery of the original audiovisual content.
+
+NOTE – Live productions are typically experienced initially in real time but can also be recorded for later redistribution.
+
+**3.2.4.4 machine narrator:** <audio description> Technology which delivers text-based audio description.
+
+NOTE – To date, machine-based narrations have not been as acceptable to persons who are blind or persons with low vision as voiced audio description.
+
+**3.2.4.5 post-produced:** <audio description> Produced after the audiovisual content.
+
+**3.2.4.6 postscript/pre-production audio description:** Audio description considered after the script has been developed, but before the event takes place.
+
+NOTE 1 – An example of this is the text of a play.
+
+NOTE 2 – This allows the script to be modified to include redundancies in audio and visual content (e.g., "Pass it to me" could be modified to "Pass my coffee, Jane").
+
+**3.2.4.7 pre-mixed production:** Content that includes an audio description that is created and recorded prior to transmission.
+
+**3.2.4.8 voice narrator/narrator/describer/audio describer:** <audio description> Person(s) and/or technology by which audio description is voiced.
+
+NOTE – A human voice narrator can also be referred to as a narrator, describer, or an audio describer. For the purpose of this Recommendation these terms are synonymous and referred to as voice talent.
+
+**3.2.4.9 writer:** <audio description> Person(s) who write(s) the audio description script.
+
+# **4 Abbreviations and acronyms**
+
+This Recommendation uses the following abbreviations and acronyms:
+
+|      |                              |
+|------|------------------------------|
+| AD   | Audio Description            |
+| ASL  | American Sign Language       |
+| DVD  | Digital Versatile Disk       |
+| JSL  | Japanese Sign Language       |
+| LSQ  | Langue des Signes Quebecois  |
+| MPEG | Motion Picture Experts Group |
+| TTY  | Teletypewriter               |
+
+# **5 Conventions**
+
+None.
+
+# **6 Framework and process considerations for audio descriptions**
+
+## **6.1 General**
+
+### **6.1.1 Alternate names for audio descriptions**
+
+Terms used in this Recommendation vary according to the country, language, region, and type of audiovisual content. They include audio description, described video, described narrative, captioning for the blind, and others. For the purpose of this Recommendation, these terms are synonymous.
+
+NOTE – In some jurisdictions, there are precise usages defined for one or more of these terms. Individuals can consult their own country's regulations for the local appropriate terminology.
+
+There are four different types of video language presentations: original language, dubbed, voice-over, and subtitled.
+
+### **6.1.2 Motivation for audio descriptions and spoken subtitles**
+
+Regardless of style, implementation, or quality, audio descriptions are not only an access strategy; it is ultimately a creative process. Since not all visual content can be described, decisions will be made regarding what is important to describe, the vocabulary used, voicing techniques, timing, and method of delivery. These decisions can help ensure that users of audio descriptions have optimum access to audiovisual content thus minimizing the extent to which they are excluded from the experience.
+
+Audio descriptions can benefit a wider audience of diverse users beyond its primary target group i.e., persons who are blind or who have low vision.
+
+Since reading is a complex cognitive process having subtitles to be read aloud can reduce access barriers and benefit various groups of people, including persons with learning and reading disabilities, persons with cognitive disabilities, older people, children, non-native language speakers as well as persons who are blind or who have low vision.
+
+## **6.2 Types of audio description**
+
+### **6.2.1 Live audio description**
+
+Live audio description is suitable for events taking place in real time.
+
+NOTE – Live audiovisual content and associated audio descriptions can also be recorded and later presented in recorded video form.
+
+### **6.2.2 Pre-mixed audio description**
+
+Pre-mixed audio description allows careful planning and evaluation of the audio description before the delivery of audiovisual content.
+
+- a) Where audiovisual is pre-recorded, the accompanying audio description should be pre-mixed.
+- b) Pre-mixed audio descriptions should be created as part of the production process rather than external to it.
+
+NOTE – This can involve the following:
+
+- Beginning the description process during the script writing phase even though details might need to be added during production and post-production.
+  - Establishing timing parameters during script writing and rehearsal processes but recording without strict attention to timing, as small adjustments can be made to the timing during post-production.
+- c) Where pre-mixed audio description was not created as part of the production process, it should be overseen or at least approved by a member of the original production team.
+
+### **6.2.3 Harmonious commentary**
+
+Harmonious commentary enhances auditory descriptions with voicing techniques and aligns emotional and expressive reactions to the script in conjunction with auditory descriptions.
+
+- a) Harmonious descriptions should be used when character expression and actions are conveyed.
+- b) Unlike announcers, audio describers should provide harmonious commentary that is in-line with the spirit and intention of the original audiovisual content.
+- c) In blending traditional video narration with harmonious commentary, a narrator should work with and/or interview sources close to the production with the goal of understanding what the audiovisual content is about and what is most important to describe.
+
+NOTE – Harmonious commentary is frequently used for live events such as sports events, a New Year's Eve concert and countdown, as well as elections, parades, festivals, Olympic ceremonies, and theatre performances.
+
+### **6.2.4 Extended audio description**
+
+- a) Extended audio description techniques may be used to allow the presentation of more information than could be presented using basic audio description.
+
+EXAMPLE 1 – A video is identified as being audio described in advance of its commencement.
+
+EXAMPLE 2 – The characters who will participate in the narration of a video that is audio described are introduced.
+
+NOTE 1 – Levels of importance, including recommendations for the types of content that are suitable to be placed in an extended audio, are discussed in clause 7.4.4.
+
+- b) Extended audio descriptions may involve one or more techniques for presenting additional information to users including the following:
+  - 1) stop motion: stopping a video while continuing the description to provide additional time for audio descriptions;
+
+- 2) video slowdown: slowing down the presentation of a video to provide additional time to insert audio descriptions;
+- 3) audio introduction: added information is included before the event starts, offering complementary information.
+
+NOTE 2 – Extended audio description is only possible with content that is recorded because its use extends the playing time of a video presentation not only before or after the presentation (during live presentations), but during the presentation itself (by pausing or lengthening the video to include more audio). This could include videos that are broadcasted and recorded by the user for a later playback.
+
+## **6.3 Creating audio description**
+
+### **6.3.1 Narrator preparation**
+
+The narrator should have the following:
+
+- a) good native language skills;
+- b) the ability to articulate;
+- c) prior knowledge of radio drama, storytelling and timing techniques (including emphasis, pauses, and sentence phrasing or shaping);
+- d) prior knowledge of when and where musical interludes occur and the order of speaking within live performances;
+- e) a sense of the rhythm and basic knowledge of music (e.g., rock, jazz, opera) that occurs within the original audiovisual content;
+- f) a sense of timing as it relates to a scene pace and scene transitions;
+- g) the ability to describe fast-paced action without overlapping dialogue, music, lyrics and intentional pauses in the audiovisual content.
+
+### **6.3.2 Content genre and programme category**
+
+The audio description team (of narrators, writers, producers) should make use of (and develop where necessary) genre-based cohesiveness across programmes or series that are within the same programme category.
+
+### **6.3.3 Scripting**
+
+Scripts can be created for both pre-mixed and live productions. It is expected that changes/additions to the scripts might be needed for live productions. Scripts for audio descriptions should consider spoken subtitles.
+
+### **6.3.4 Writer considerations**
+
+The writer should have the following:
+
+- a) a familiarity with the communication needs of people who are blind or have low vision;
+- b) prior knowledge of or research into character names, locations and other specific terminology related to the original content (e.g., uniforms, monuments, architectural elements and fashion styles);
+- c) story writing skills (e.g., skills in building a climax, developing characters, setting up plots, etc.);
+- d) the ability to write concisely and anticipate the quality of spoken words per specific time constraints;
+- e) the ability to create rhythm within phrases through word choices, order and syllable counts.
+
+### **6.3.5 Recording**
+
+It should be recognized that any audio description might be recorded (by users if not by producers also), regardless of whether the video programme was live or pre-mixed.
+
+### **6.3.6 Volume**
+
+- a) The volume of AD and spoken subtitles must have a good balance with the volume of the original audiovisual content audio.
+
+NOTE 1 – In some instances, audio description is delivered as a separate stream from the original content. In this case it is important for both volume levels to be user-controlled where possible.
+
+- b) Audio descriptions and spoken subtitles should be prepared so that users can adjust the volume of the audiovisual content and the volume of audio description separately.
+
+NOTE 2 – This allows for flexibility in the way the content is used.
+
+NOTE 3 – Regulatory rules on volume can exist and can vary from country to country.
+
+### **6.3.7 Audio technician considerations**
+
+An audio technician should assist with the noise cancellation and audio signal processing levels to ensure that cutoff, microphone noise, background noise, levels between the audio description and the live soundtrack and other audio factors are mixed and filtered appropriately.
+
+### **6.3.8 Inclusion of consumers in the process of creating audio descriptions**
+
+The full range of consumers of audio descriptions should be included in the process of creating audio descriptions where possible.
+
+NOTE 1 – This can take the form of focus groups, employment of a consumer as a marketer or community consultant, use of a blind or low vision narrator. Consumers might also be included where stakeholder groups are actively involved in creating an audio description and marketing specific audio-described performances.
+
+NOTE 2 – It is important to consider the balance between artistic expression and consumer needs.
+
+### **6.3.9 Inclusion of consumers in evaluating audio descriptions**
+
+If an evaluation is part of the process of developing an audio description, representative consumers of audio descriptions should be involved.
+
+NOTE 1 – It is important to evaluate pre-recorded and live audio descriptions wherever possible.
+
+NOTE 2 – It is important for evaluations to focus on the clarity of the content of the audio description and to avoid dealing with stylistic or other artistic issues.
+
+NOTE 3 – It is also important to understand the enjoyment of the target audience; however, the entertainment of the audio description needs to be considered in relation to the general entertainment of the genre. It can be difficult to separate these two things.
+
+## **6.4 Live audio description**
+
+### **6.4.1 Live narration considerations**
+
+- a) Live narrators should work in teams of two.
+- b) For the purpose of continuity, the narrator who is not performing should remain in the booth/location to assist by suggesting what needs describing as it comes up or identifying people and places in real time (such as audience's reactions to live and interactive performances through applause, laughing, standing ovations, etc.).
+- c) For rehearsed events, e.g., in a play the narrator who is not performing should be stationed in the auditorium to monitor the reception of the narration and to intervene if the transmission fails.
+
+- d) In the case of gallery/museum/heritage sites, the live tour should be conducted by the describer with a curator who will lead the group around the venue.  
+NOTE 1 – An audio technician could also play a key role in pointing out descriptions or providing names of those appearing on camera during the live event.
+- e) The narrator(s) should be at the broadcast facilities during a live event.  
+NOTE 2 – Broadcasted feed can lag time in receiving video from a remote location; audio mixing and sound controls can impact the quality of an audio description if the video narrator is not on location.
+- f) The audio description narrator should be isolated in a separate space.  
+NOTE 3 – The location of the narrator has an impact on the recording technologies used and noise cancellation requirements.  
+NOTE 4 – Using an isolated space allows the narrator to be able to speak without disrupting the audience at the live event. It also prevents noise from external sources from being transmitted by the narrator's equipment to the listener.  
+EXAMPLE 1 – Newscasts are normally straightforward because they take place in the same location each day. The narrator can be set up in a sound-proof booth somewhere in the studio facility with a video monitor and headphones.  
+EXAMPLE 2 – Many sports facilities have media areas where the media (radio and television) announcers are located.  
+EXAMPLE 3 – The narrator is located away from the audience so that the audiences voices does not disturb them at a live event such as a telethon, a play or a sports event.
+- g) If the description is prepared for a recorded audio guide then it should be of studio quality.
+- h) With allowances for translation and the possible need to describe unseen elements or unforeseen events, narrators should view and describe only what appears on stage, video, visual art or object/artwork/building.
+
+NOTE 5 – If the narrator is viewing the entire stage/arena and not looking at a video monitor then the description might not match what is being broadcasted due to the camera angles, shot changes, zoom, etc.
+
+### **6.4.2 Preparing for live narration**
+
+- a) The role of a script should be determined in advance of the narration and provided as guidance to the narrator.  
+NOTE 1 – This way the narrator can predetermine how closely the script needs to be followed and how much the narrator can add to or modify the script.
+- b) Where possible, a script should include cues for timing.
+- c) A script should be prepared and reviewed by the narrators in advance of the narration. For drama, opera, etc., the provision of a script in advance of the narration is essential.  
+NOTE 2 – A script can vary in its detail and contents from describing notes to fully prepared lines for delivery. However, it is important to recognize that spontaneous and unplanned events can occur during live broadcasts and events and to leave room for these to be allowed for within any script.  
+NOTE 3 – A script can be produced with reference to a pre-recorded live performance of, for example, a play or a live show. For drama, opera, etc., the provision of a recording of the performance is essential to aid the production of the narrator's script particularly with regard to timing the narration.  
+NOTE 4 – In the visual arts / heritage sector, the describer needs to prepare by meeting the relevant curatorial/education staff and having access to catalogues and other research material.
+- d) The audio technician should visit the location ahead of time to identify the problems.
+- e) Sound tests with equipment to be used on location should be conducted well in advance of a performance to allow for sufficient time in making modifications to equipment or equipment placement.
+
+### **6.4.3 Narrator transitions in live audio**
+
+- a) Depending on the length of the programme narrators should alternate every half an hour to maintain their energy levels. This requirement may be relaxed for stage performances when long passages of dialogues provide narrators with natural breaks and the interval is logistically the most appropriate place to switch narrators. For live tours, one describer can provide the description for the whole tour.
+- b) Narrator transition should feel natural.
+- c) There should not be any interruption in the timing of the audio description as the narrator transition occurs.
+
+## **6.5 Pre-recorded descriptions**
+
+### **6.5.1 Creation of pre-mixed audio after the main production process**
+
+Where pre-mixed audio description is not created as part of the production process, it should be overseen or at least approved by a member of the production team if available.
+
+### **6.5.2 Audio description team for pre-mixed audio**
+
+The audio description team should involve a blind or low vision individual.
+
+### **6.5.3 Evaluation of pre-mixed audio**
+
+An evaluation of the audio description should be done mid-production rather than leaving it until the end.
+
+NOTE 1 – The necessity for approval depends on the content and on the expertise of the audio describer.
+
+NOTE 2 – The writer compiling an audio description script can view the programme without the images to determine the challenges of the programme as part of developing the script.
+
+### **6.5.4 Voices for pre-mixed audio**
+
+The audio description should be well timed to harmonize with the sounds and the voices of the original audiovisual content.
+
+### **6.5.5 Sound engineering for pre-mixed audio**
+
+Sound engineers should supervise recording and mixing to avoid unbalanced sound reception.
+
+# **7 Guidance on audio description**
+
+## **7.1 General considerations**
+
+### **7.1.1 User considerations**
+
+- a) At the beginning of each programme, the user should hear an auditory notification such as "This programme is audio described."
+- b) The auditory notice should assume that the listener is using audio description.  
+EXAMPLE – "This programme is audio described" is preferable to "This programme is available...".
+- c) The availability of audio description should be identified by a standardized logo both on the screen (in the case of recorded video content) and in any media where it is advertised.  
+NOTE – It is recognized that logos might vary from country to country. Logos must also be consistent across as many jurisdictions as possible.
+- d) Users (including blind or low-vision persons) should easily be able to access information (both in real time and in advance) that identifies when an audio description is available and for which programmes or events.
+
+- e) The user should be provided with an easy-to-use means of selecting and changing between presenting such as the following:
+  - 1) basic audio description;
+  - 2) extended audio description;
+  - 3) no audio description.
+- f) When multimedia content that is translated with subtitles has an intense dialogue it might not be possible to translate and describe everything. If it is necessary to shorten the audio description, providers of audio descriptions must make sure that there is an introduction where the characters, scenery, etc. are well presented. If the spoken subtitles are summarized the user also needs pre-information.
+
+### **7.1.2 Consistency across technologies**
+
+Audio description should be consistent regardless of the technology or method being used to transmit and/or present the original content.
+
+NOTE 1 – Some technologies used for transmission include cable, satellite, Internet and DVD.
+
+NOTE 2 – Some technologies used for presentation include television, computer and smartphone.
+
+### **7.1.3 Consistency within a programme and series**
+
+- a) The style of audio description should be consistent throughout a programme.
+- b) The style of audio description should be consistent throughout the programmes in a series.
+
+### **7.1.4 Placement of descriptions**
+
+- a) Audio description should only occur during non-dialogue pauses.
+- b) Audio description should never occur over dialogue.
+- c) Audio description should not obscure music that is necessary to understand the storyline.
+
+NOTE – Music (diegetic or non-diegetic), sound effects and/or ambient noises might be used to increase emotional resonance within a scene or to help enhance the storyline. It is important to be sensitive to the inclusion of audio descriptions in relation to music, sound effects and ambient noise and to understand the purpose of the music, sound effect or ambient noise before deciding whether to overlay descriptions on a song, musical piece, sound effect or an ambient noise.
+
+### **7.1.5 Use of pauses**
+
+- a) Audio description should not fill every moment.
+- b) Where possible, descriptions should allow time for the listener to pause and enjoy/experience quiet moments, music (that is used to increase emotional resonance) and/or background noise.
+
+## **7.2 Developing an audio description**
+
+### **7.2.1 Clarity in audio descriptions**
+
+Audio describers should present their information in a manner that can be easily understood by their intended users.
+
+NOTE 1 – Proper pronunciation/articulation is the primary objective of the narration, and it supersedes all other considerations for narration.
+
+NOTE 2 – The preparation of a script is useful for lexical choice and selecting which details to describe.
+
+### **7.2.2 Creativity in audio descriptions**
+
+- a) As a creative process, the audio description should consider the history, logic and the tangible rules that govern genre and sub-genres.
+
+NOTE – This is encouraged because the diverse nature of a film, television, recorded, theatrical and online content require detailed consideration of the genre involved to appreciate its nuances.
+
+EXAMPLE 1 – A narrative genre has an audio description that elaborates more on the characters whereas an action genre has an audio description that focuses more on the plot descriptions.
+
+EXAMPLE 2 – A video that has repeating parts has repeating audio descriptions to provide cohesion within the content theme.
+
+- b) The words selected and used for description should be appropriate to the era and genre of the original content.
+
+EXAMPLE 3 – A film portraying the Western United States during the early 1900s might refer to black people as "coloured people" in a dialogue.
+
+EXAMPLE 4 – The audio description of a music video makes use of a rhythmic diction.
+
+### **7.2.3 Narrating/reading audio description scripts**
+
+- a) A narration style for description should be identified and followed consistently within the same content. There are different styles that could be adopted, and which have different implications for how an audio description is developed and delivered.
+
+EXAMPLE 1 – For a third-person style of description, the voice of the narrator is clearly distinguishable from the other voices in the video. Where the cast is predominantly male, the director chooses to have a female narrator to clearly distinguish the narrator from the production itself or to have a male narrator to integrate better with the style of the audiovisual content.
+
+NOTE 1 – Speech synthesis can replace the human narrator in the audio description; however, research indicates a preference for the human voice-over voice synthesis.
+
+NOTE 2 – Research indicates that if a speech synthesis is used there is a preference for quality speech synthesis since the synthesized speech is clearly identified as an audio description and avoids confusing the human voice of an audio describer with the character's voices.
+
+NOTE 3 – The quality of a speech synthesis is determined by its similarity to the human voice and by its ability to be understood. People familiar with using speech synthesis can be used to judge the quality of the speech synthesis.
+
+EXAMPLE 2 – The reading of spoken subtitles or other unique visual elements (such as point displays or thought bubbles) is voiced using speech synthesis or by another narrator to indicate a change in content delivery.
+
+EXAMPLE 3 – Two voices, male and female are used. One is used to read spoken subtitles and one to read audio description scripts.
+
+- b) The voice of the narrator should complement the content being described.
+
+NOTE 4 – Often, trained actors are employed as narrators and use their talent to infuse the description with appropriate emotive characteristics.
+
+EXAMPLE 4 – A young voice is used to narrate a video intended for children to make the narration seem that it is coming from another child. In some countries, a female voice is used for audio describing children's programmes.
+
+- c) The narrator should be identified at the beginning of the programme to eliminate confusion unless, to advance their artistic vision the director chooses to have the narrators remain anonymous.
+
+NOTE 5 – If the main character is anonymous, to coincide with the story, the director might choose to have the narrator remain anonymous too.
+
+- d) The narrator should be consistent throughout a series of programmes unless, to advance their artistic vision the director chooses to have multiple narrators.
+
+EXAMPLE 5 – If the main character dies halfway through a film and a new character continues the story from a different perspective and gender, the director could decide to switch to a new narrator to reinforce the break in perspectives.
+
+- e) The scriptwriter and the narrator of the audio description should not alter, filter, or exclude content or images that disturb or offend them.
+
+NOTE 6 – The narrator's role is to describe what is seen and not to censor it.
+
+EXAMPLE 6 – If the original script uses coarse language the description script adopts similar coarse language.
+
+- f) The scriptwriter and narrator should make use of a background or previous knowledge of the culture from which the content originated.
+
+- g) Where it is not possible to make use of the knowledge of the culture in advance, pre-recorded audio descriptions should be evaluated by persons with a background in or previous knowledge of the culture from which the content originated, before being released.
+
+NOTE 7 – This also includes knowledge of how to voice spoken subtitles in films which include them due to language changes.
+
+EXAMPLE 7 – In a Chinese horror film, a character selects the number four in an elevator. This is significant and indicates a potential threat. Knowing the cultural significance of the number four in Chinese culture, a Chinese narrator might describe the number whereas an Italian describer might not.
+
+## **7.3 Styles of narration**
+
+### **7.3.1 Newsreader style**
+
+Newsreader style focuses on relaying information in a serious manner.
+
+NOTE – This style is appropriate when the goal is to educate viewers, as is frequently demonstrated in documentary films or news programme categories.
+
+### **7.3.2 Commentator style**
+
+Commentator style focuses on providing entertainment.
+
+NOTE – This style is appropriate when the goal is to include commentary and effective content together with factual content, as is frequently utilized for content that is primarily for entertainment purposes.
+
+EXAMPLE 1 – When describing visual actions and events for a situational comedy, the narrator takes on a light-hearted tone, strategically choosing to communicate comedic visual events in a tone that is similar to the show.
+
+EXAMPLE 2 – For a courtroom drama, the narrator aims to capture and maintain the intensity of each scene.
+
+### **7.3.3 First-person**
+
+The narrator can take on the role of a character describing the character's perspective and reflections on the events.
+
+When a first-person narration is being used it should be made clear to the audience that the narrator is taking on a first-person role.
+
+NOTE 1 – Past tense is the common verb form used for this style.
+
+EXAMPLE 1 – "He moved his queen diagonally to take my rook. Then I clobbered his queen with my bishop."
+
+EXAMPLE 2 – "There was an 18-wheeler towards my left side and a police car chasing me. I put the pedal to the metal..."
+
+EXAMPLE 3 – While "Ann wears only one glove." is in the third-person, "I noticed that Ann is wearing a single glove." is in the first-person.
+
+NOTE 2 – The nature of the first-person is considered to be one perspective that may or may not be reliable.
+
+### **7.3.4 Third-person**
+
+The narrator speaks from an external point of view.
+
+In a third-person narration, the narrator should not include or reference themselves in the narration.
+
+EXAMPLE 1 – "The sun rises over the city skyline."
+
+EXAMPLE 2 – "Don picks up a book and begins to read."
+
+EXAMPLE 3 – While "We now see Bruce entering the living room." is in the first-person; "Bruce enters the living room." is in the third-person.
+
+## **7.4 Levels of importance**
+
+### **7.4.1 Using importance levels**
+
+Too much information can interfere with a user's ability to understand the programme. Additionally, depending on the programme genre there may be very little opportunity to place information.
+
+Levels of importance are determined by the persons responsible for developing the audio description (e.g., content providers, scriptwriters and narrators) and will vary between different contexts.
+
+NOTE – It is useful to include consumers of audio descriptions in making this decision where possible.
+
+### **7.4.2 Essential information**
+
+Essential information is information necessary for the listener to understand the visual and auditory content within the video or performance in which it occurs.
+
+- a) Elements essential to the narrative should be described before additional details are provided.
+- b) Audio description should primarily describe the most essential visual details for the comprehension of context, plot, and characters.
+
+NOTE 1 – Essential information can have some or all of the following properties:
+
+- It is aimed at the target audience.
+- Content must be known to be easily comprehensible.
+- Most people want/need it most of the time.
+- The listener would be confused as to what is happening without this information.
+- For the content provider, this is the information that they absolutely want the listener to know.
+- It identifies visual information that intentionally conflicts with the dialogue or background sound.
+
+As more of these properties apply it is more likely that the information is essential.
+
+NOTE 2 – If time allows, the audio description can include additional descriptions about the setting, a character's physical appearance and/or clothing to enhance the experience.
+
+### **7.4.3 Significant information**
+
+Significant information is secondary to essential information. It provides listeners with a complete understanding of the visual content and sounds within the audiovisual content in which it appears.
+
+Significant information should be presented if time permits in the audio description.
+
+NOTE – Significant information can have some or all of the following properties:
+
+- It is aimed at the target audience.
+- It gives a more detailed and thorough understanding of the audiovisual information.
+- It is information that can be obtained by more than, for example, a quick glance at a video.
+- It is important for the user to know about it as they are listening to the main audio content to understand the video or event.
+
+- Without this information the user has an idea of what the video or event is about but does not have a detailed understanding of it.
+- For the content provider this is information that further explains and provides more details on what they want to tell the listeners.
+
+As more of these properties apply it is more likely that the information is significant.
+
+### **7.4.4 Helpful information**
+
+Helpful information provides a thorough understanding of the visual content within the video or event in which it occurs.
+
+Helpful information is information that might be of interest to some users occasionally and if created, should be placed in an extended audio description file.
+
+NOTE – Helpful information can have some or all of the following properties:
+
+- It might be of interest to some who are the target audience of the audiovisual content.
+- It is the "director's cut" version of the audio description that further defines the cinematic and background details.
+- It can be used to reassure the listener that they have not missed something of importance.
+- Without this information listeners have a fairly complete understanding of what the audiovisual content is about but have any additional information that they would still want to know.
+- It includes different or other possible interpretations of the information being expressed by the visual image.
+- For the content provider this is information that could clarify some things for some people, for example, those with cognitive impairments, English as second language speakers or children.
+- It includes optional extra information that is seldom wanted or needed and which elaborates on what is already available.
+
+As more of these properties apply it is more likely that the information is helpful.
+
+### **7.4.5 Irrelevant information**
+
+Information is irrelevant if it does not help to provide additional understanding of the visual content for any users to understand the audiovisual content in which it occurs.
+
+Information that is irrelevant should not be presented to users either in a basic audio description or in an extended audio description.
+
+NOTE – Information that is irrelevant can have some or all of the following properties:
+
+- Very few users will want to know this information.
+- It is rarely helpful.
+- It is not important enough to mention.
+- Without this information the listener knows everything that they want or need to know to understand and enjoy the video or event.
+- This is information that might result in unintended confusion or boredom, and which does not help users understand what the content provider wants to communicate.
+
+As more of these properties apply it is more likely that the information is irrelevant.
+
+## **7.5 General guidance on descriptions**
+
+### **7.5.1 Description of sounds**
+
+- a) Common well-known sounds such as a ringing telephone, barking dog, or a car horn should not be identified / described unless the sound is out of context or is coming from an unknown source.
+
+EXAMPLE – Malcolm is in the driver's seat of his car. Another car moves close behind, and the driver honks their horn and shakes their middle finger angrily. The description of the honking horn need not be described as the honking can be heard and it would be an unnecessary description.
+
+- b) An unknown sound should not be identified / described if such a description will give away the plot.
+- c) In the case of a subtitled programme, a description with the sound effects should be added at the beginning of the video if there are spoken subtitles.
+
+NOTE – This is considered to be "describing the screen real estate".
+
+### **7.5.2 Logos / credits / titles**
+
+- a) Titles and credits at the beginning and the end of programmes should be read at a normal pace without rushing.
+- b) In general, although it is unlikely that there will be sufficient time to allow for a verbal delivery of all credits, effort should be made to include as many as possible.
+
+### **7.5.3 On-screen text**
+
+The narrator should acknowledge the text elements, describe the content, and read the messages.
+
+NOTE – Signs, speech bubbles and other non-captioned on-screen text elements might appear in the background which has some relevance to the setting, plot, or understanding of actions taking place.
+
+EXAMPLE – "A road sign reads: 'Caution construction zone'."
+
+## **7.6 Guidance on identifying objects**
+
+### **7.6.1 Identifying objects**
+
+- a) In languages that have definite and indefinite articles, when an object is first introduced, the indefinite article (e.g., "a", "an" in English) should be used.
+- b) When the same object is referred to or has already been known, named, or identified, the definite article (e.g., "the" in English) should be used.
+
+NOTE 1 – This helps distinguish new from known objects and multiple objects.
+
+EXAMPLE 1 – "Sandra removes a chocolate from a heart shaped red box. She bites into the chocolate, closes her eyes and smiles."
+
+EXAMPLE 2 – "I entered the cave bearing a sword. I saw the sword Excalibur embedded in a large stone and ran to it. I dropped my own sword on the ground and slowly withdrew the jewel-encrusted Excalibur from the stone."
+
+EXAMPLE 3 – "Alan takes a broom out of the closet. He takes the broom with him and leaves the kitchen."
+
+NOTE 2 – An object can be considered as known if its presence is understood as a given or is common to the circumstance or setting.
+
+EXAMPLE 4 – "Ida and George are sitting on the couch."
+
+EXAMPLE 5 – "I lit the candles on the dining room table."
+
+EXAMPLE 6 – "She waters the flowerbeds with the garden hose."
+
+### **7.6.2 Describing colour**
+
+- a) Colour should be included in descriptions as appropriate.
+
+- b) It should not be assumed that colour holds no significance to blind persons or persons with low vision or that they have never seen colour or lack understanding of the concept of colour or its cultural symbolism.
+
+NOTE – Some poetic descriptions involving the symbolism of colours might not be easily translated into other languages or cultures.
+
+- c) Word choices for colour may also contain a textural element.
+
+EXAMPLE 1 – "The ballroom is lit with a fire." The word "fire" in this example is intended to represent the colours of red and yellow but also has textural properties of heat or warmth.
+
+EXAMPLE 2 – "My gown is trimmed in gold". The word gold used in this example can be understood as a colour but also has textural properties of being heavy and soft.
+
+### **7.6.3 Describing visual effects**
+
+- a) Camera-specific terminology should be avoided unless it is a commonly used term in the language.
+
+NOTE 1 – Visual distortions such as blurring, focus and mirror views can be used to provide a character's point of view or mood.
+
+NOTE 2 – Camera angles or camera point-of-view can be meaningful.
+
+EXAMPLE 1 – "I focused on a small paper lying on the sidewalk." The camera zooms in on the small paper on the sidewalk.
+
+NOTE 3 – Lighting and lighting effects can be used for mood and/or symbolism.
+
+EXAMPLE 2 – "The light cast a shadow of someone behind the curtains."
+
+EXAMPLE 3 – "The operating room becomes awash in white light. A blue sky appears."
+
+- b) Some dances, dance styles or movements have specific names that should be used. When the dance is not identifiable by a specific name, a more general term can be used.
+
+NOTE 4 – Dancing and choreography are a combination of movements, music and motions in addition to the dress and costume attire of the individuals appearing within a scene.
+
+EXAMPLE 4 – A specific type of dance could be "the Tango", whereas a general term could be "Latin dancing".
+
+EXAMPLE 5 – A specific martial art form could be "Karate", whereas a general descriptor could be "martial arts".
+
+## **7.7 Guidance on identifying persons**
+
+### **7.7.1 Identifying characters or places by name**
+
+- a) Minor characters or places should be described by their prominent physical appearance or identity.
+
+- b) Once an appellative is established for minor characters it should be used consistently.
+
+- c) Minor characters or places, or those whose names remain unknown should be described in general terms.
+
+EXAMPLE 1 – "A tall well-dressed woman walks through the crowded sidewalk to the car and leans through the open window and asks..."
+
+- d) When known characters or places first appear they should be identified or introduced using their full name.
+
+- e) After their first introduction, the narrator should consistently use the name that is most commonly used by the other characters to refer to well-known characters.
+
+EXAMPLE 2 – When a doctor first appears, the narrator says, "Michael Hunt entered the room." Since Michael is well known to the others in the room the narrator later refers to him as "Michael".
+
+EXAMPLE 3 – "Raj Binder enters the classroom and approaches Consuela Singh. Raj grasps Consuela's hand and together they turn towards the children sitting at their desks."
+
+### **7.7.2 Physical appearance**
+
+#### **7.7.2.1 Character's physical appearance**
+
+- a) Third-person descriptions should describe qualities that would allow the listener to draw their own conclusions i.e., long shiny dark hair, large brown eyes, tall athletic build and flawless complexion.
+- b) Third-person descriptions should avoid using terms that evaluate the character's appearance (such as beautiful, lovely, ugly, plain) unless relevant to the plot or genre.  
+NOTE – For third-person descriptions the level of attractiveness of a character is a value judgment.
+- c) First-person descriptions may provide a personal assessment of attractiveness if it is relevant to that particular character.  
+EXAMPLE – When the narrator takes on the character of a beauty pageant contestant using language that describes the individual's self-assessment of her beauty (or that of others) is appropriate.
+
+#### **7.7.2.2 Facial / physical expression**
+
+Terms should be used which describe emotion or reaction through facial / physical expressions when they are important to the understanding of characters and plot.
+
+EXAMPLE – "John gives an evil smile as he escapes in his car" adds extra unnecessary words "gives an evil smile" where one word is sufficient as in "John sneers as he speeds away in his car."
+
+#### **7.7.2.3 Attire**
+
+Describing the clothing worn by characters should be included if it helps establish characterization, role, plot development, setting, occasion, location, or the enjoyment of the genre.
+
+NOTE – Attire is often used to portray a stereotype. In these instances, a sighted viewer instantly identifies the character type by their clothing. The narrator could either describe the attire or the character type as appropriate for the situation.
+
+EXAMPLE 1 – A comedy series has a recurring character who is a nerd/geek. Describing this character's unfashionable, outdated, and ill-fitting or inappropriate clothing could help support the characterization.
+
+EXAMPLE 2 – A scene in a drama series involves investigators entering a bar where many of the patrons are tattooed and wearing leather and chains. The narrator could elect to simply call them "bikers" or to describe their attire or both.
+
+EXAMPLE 3 – A person wearing a white coat over their regular clothing and carrying a stethoscope is a character stereotype that instantly identifies them as a doctor.
+
+### **7.7.3 Race / ethnic origin**
+
+#### **7.7.3.1 Identifying race / ethnic origin**
+
+The appearance of characters should not require that they be identified by race or ethnic origin unless these types of identifications provide meaningful information or insight to a sighted viewer which would not otherwise be available to persons who are blind or who have low vision in a similar timeframe i.e., plot development, character motivation or background.
+
+NOTE 1 – Consider the role of a casting director. Is a character's race or ethnicity relevant to the selection and casting of roles and if so, why?
+
+NOTE 2 – If sighted viewers could use the race or ethnic origin of the characters as clues to solving the crime or providing a better understanding of the culture or behaviour of the characters, it would be appropriate to include race/ethnic origin in the description.
+
+EXAMPLE 1 – In a police drama series, investigators are interviewing witnesses/victims of a robbery. The actors playing the roles are Asian, Black and Aboriginal. The narrator does not identify the subject's race/ethnic origin unless it is relevant to the plot, and it cannot be recognized from the existing dialogue.
+
+EXAMPLE 2 – A medical series with a large multiracial ensemble cast have doctors treating patients of various races and ethnic origins. In these instances, the race or ethnic background of the characters might have no relevance. The rare exception might be relevant if such information specifically relates to a plot development i.e., the patient has a disease that is specific to a racial/ethnic group.
+
+EXAMPLE 3 – A reality show has contestants of various racial and ethnic backgrounds. If the narrator thinks or has been informed by the director that this type of information is useful or meaningful to the viewer, then it is important that all the contestants be identified using these characteristics.
+
+#### **7.7.3.2 Terms to describe race / ethnicity**
+
+- a) Derogatory or disrespectful language should never be used unless it is part of the development of the character in a first-person style.
+
+EXAMPLE – If the narrator took on the role of an Indian princess from the mid-nineteenth century, the use of derogatory language when talking about or referring to people of a "lower" class might be appropriate if that type of language is used in the original content.
+
+NOTE – It is important to remain sensitive and aware that some ethnic/racial descriptive terms accepted in western cultures might differ from other cultures and do change over time.
+
+- b) Descriptions should use common and factual terms to describe individuals that would be understood by the majority of listeners such as the following:
+- 1) light brown, brown, dark brown, tan, light tan;
+  - 2) light/fair skinned, dark skinned, olive-skinned;
+  - 3) tan, ruddy, olive, white, yellow.
+- c) If the attire of a character suggests their cultural or ethnic origin then this information should be described i.e., kilt, burqa, saris, kimono, parka, etc.
+
+#### **7.7.3.3 Use of racial / ethnic descriptive terms in settings**
+
+Non-judgmental ethnic terms may be used to concisely describe a setting.
+
+NOTE – There are instances where the physical location/setting is relayed visually through stereotyped images or understandable cultural clues. Such settings and descriptive terms are currently accepted in western cultural vernacular. Attempting to describe the setting to a blind person or a person who has low vision through a collection of "descriptive clues" rather than providing an interpretation otherwise obvious to all sighted viewers would not be reasonable.
+
+EXAMPLE – An open-air marketplace has multitudes of stalls and exotic goods on display and if the vendors and consumers are dressed in traditional middle eastern attire it is described as "an Arab market".
+
+### **7.7.4 Gender-related**
+
+#### **7.7.4.1 Identifying gendered expression**
+
+- a) The appearance of characters should not require that they be identified by their gender expression unless these types of identifications would provide meaningful information or insight to a sighted viewer that would not otherwise be available to persons who are blind or have low vision in a similar timeframe i.e., plot development, character motivation or background.
+
+NOTE – Consider the role of the casting director. Is a character's gender expression relevant to the selection and casting of roles and if so, why?
+
+EXAMPLE 1 – In a comedy series, characters are typically males appearing in cross-dress clothing acting as female characters (even modifying their voices to a higher pitch). This is part of other characterizations that is used for comedic effect. If sighted viewers benefit from the entertainment value of the cross-dressers, then it might be appropriate to include cross-dressing in the description.
+
+EXAMPLE 2 – In a drama, the central character first appears as a male until it is revealed he was born biologically female. The character struggles with society's views of gender expression in a conservative small-town environment. To be accepted as a male the character changes his voice to a lower pitch. The narrator refers to the character as a female who is transitioning to a male.
+
+- b) In instances where the gender of the person helps the audience in understanding the character development, it should be described.
+
+#### **7.7.4.2 Terms to describe lesbian, gay, bisexual, transgendered, and queer (LGBTQ)**
+
+- a) Derogatory or disrespectful language should never be used unless it is part of the development of the character in a first-person style.
+
+EXAMPLE – If the narrator took on the role of a gay priest from the mid-nineteenth century, the use of derogatory language, such as "homo," when talking about or referring to him might be appropriate if that type of language is used in the original content.
+
+NOTE – It is important to remain sensitive and aware that some gendered or/and LGBTQ descriptive terms accepted in western culture might differ from other cultures and do change over time.
+
+- b) Descriptions should use common and factual terms to describe individuals that would be understood by the majority of the viewers such as lesbian, gay, bisexual, transgendered, or queer.
+- c) If the attire of a character suggests their identity, then this information may be described i.e., butch, femme, masculine, and/or feminine, etc.
+
+### **7.7.5 Disabilities**
+
+#### **7.7.5.1 Identifying disabilities**
+
+- a) The appearance of characters should not require that they be identified by their disability unless these types of identifications would provide meaningful information or insight to a sighted viewer that would not otherwise be available to persons who are blind or who have low vision in a similar timeframe i.e., plot development, character motivation or background.
+
+NOTE – Consider the role of a casting director. Is a character's disability relevant to the selection and casting of roles and if so, why?
+
+EXAMPLE 1 – If the audience knows a character is using a wheelchair and that person enters the screen. The narrator says that person "comes in" rather than "rolls in" because the act of arriving is what is important to the plot.
+
+- b) If an assistive device is central to a character's movement it may be appropriate to include verbs that accurately describe the character's entrance.
+
+EXAMPLE 2 – A wheelchair rugby documentary having diverse cast members that includes amputees, quadriplegics and paraplegics. In this instance, the diversity of the character's physical abilities might have no individual relevance. The rare exception might be if such information specifically relates to a plot development i.e., one of the players has more use of their upper body and hands and this has an impact on the other players perceptions of their involvement on the team.
+
+#### **7.7.5.2 Terms to describe persons with disabilities, assistive devices, and disability**
+
+- a) Derogatory or disrespectful language should never be used unless it is part of the development of the character in a first-person style.
+
+EXAMPLE – If the narrator took on the role of someone exhibited in a "freak show" during the mid-nineteenth century, the use of derogatory language when talking about or referring to them might be appropriate if that type of language is used in the original content.
+
+NOTE 1 – Language being used to talk about disability affects societal perceptions of persons with disabilities. It is important to remain sensitive and aware that some disability descriptive terms accepted in western culture might differ from other cultures and can change over time.
+
+- b) Commonly used terms should be used to describe individuals who would be understood by the majority of viewers such as someone with epilepsy, schizophrenia, Down syndrome, cerebral palsy, blind or has low vision, quadriplegic and autistic.
+
+NOTE 2 – It is important to recognize the terms that are preferred by the people being described (e.g., deaf individuals often prefer to be described as "a deaf person" rather than "a person who is deaf").
+
+NOTE 3 – Derogatory terms to be avoided currently include retarded, idiot, moron, imbecile, wheelchair bound, crippled, handicap and gimp.
+
+- c) Since the above lists are not exhaustive, care should be taken to check the situation in particular jurisdictions with organizations controlled by persons with disabilities.
+
+NOTE 4 – Common assistive device terms include the following:
+
+- mobility: elbow crutches, wheelchairs, scooters, artificial limbs, walkers, casts, electric scooter, and wheelchair ramps;
+- respiratory: breathing tubes, respirators, inhalator or inhalers, etc.;
+- visual / auditory: hearing aids, teletypewriter (TTY) phones, cochlear implants, guide dogs, white canes, glasses, etc.;
+- others: EpiPens (Epinephrine auto-injector), catheter, feeding tube, other medical devices.
+
+NOTE 5 – Types of disfigurements include burns, bruising, rash, scars, birthmarks, amputation, reconstructive surgery, balding, etc.
+
+NOTE 6 – Each sign language has its own name [e.g., American sign language (ASL), Japanese sign language (JSL), langue des signes Quebecois (LSQ), ASL interpreters, Braille].
+
+### **7.7.6 Age**
+
+- a) Commonly used descriptive words that immediately identify the approximate age of the subject: infant, baby, toddler, child, pre-teen, teenager, youth, adult, young, middle-aged, elderly, should be used in third-person descriptions of age, unless greater detail is required.
+
+NOTE – Further descriptions could include the ranges of ages, such as the following:
+
+- "a child of 8 to 10 years old";
+- "a woman in her early 30s";
+- "a man in his 50s".
+
+- b) For a first-person description, it may be appropriate to state the age of the character e.g., "I was 15 years old".
+
+## **7.8 Guidance on relationships**
+
+### **7.8.1 General guidance on explicit content**
+
+Script related to violent or sexually explicit content should not have the effect of censoring or changing the original content.
+
+NOTE 1 – If the original content has a visual-only warning of the inclusion of violent or sexually explicit material, it is important that a warning be included in the introductory audio description.
+
+NOTE 2 – If a blind person or a person with low vision would be prevented from understanding or appreciating the original content, it is important for narrators to deliver scripts that describe the explicit nature of the content.
+
+NOTE 3 – If sighted viewers could use information about the violent or sexually explicit behaviour of the characters, or the nature of specific images in the original content as clues to provide a better understanding of the plot, or the culture or behaviour of the characters, it would be appropriate to include unambiguous references to such behaviour or such images in the description.
+
+### **7.8.2 General guidance on relationships**
+
+In most instances, unless the relationship between individuals is known, it should not be specified.
+
+NOTE 1 – Certain relationships would be obvious or inferred to a sighted viewer because of cultural stereotypes i.e., a young woman holding an infant would often be described as a mother, a man throwing a
+
+ball to a child would be described as a father, an elderly person holding a baby or playing with a small child might be called a grandparent.
+
+NOTE 2 – If the true nature of the relationship is unknown, the narrator could use terms such as motherly, fatherly, grandfatherly, etc. to describe such individuals.
+
+### **7.8.3 Establishing place / setting / time of day**
+
+Information on the view of the general setting, time of day and sometimes weather conditions which is often provided very briefly during the opening credits or the opening minutes of the programme, should be shared with the listeners.
+
+NOTE 1 – Even in a recurring series where many viewers might already know the primary location, confirmation, weather, and/or the time of day establishes the context and possible relevance.
+
+EXAMPLE 1 – "Sailboats of all sizes race through the harbour with their sails furled."
+
+EXAMPLE 2 – "A full moon is shining over the Boston general hospital."
+
+EXAMPLE 3 – "Children are frolicking at the shoreline in this crowded beach."
+
+EXAMPLE 4 – "During daytime in the city, heavy snow fell as cars moved slowly in the congested traffic."
+
+EXAMPLE 5 – "My neighbour's son was riding his bike and delivering newspapers on my street in the rain."
+
+NOTE 2 – It is important that flashbacks, flash forwards, jump in time, re-enactments, time distortions, and time travel is identified using appropriate time reference terminology.
+
+EXAMPLE 6 – "100 years later, a spaceship crashed."
+
+### **7.8.4 Interaction between animated characters / objects and real actors**
+
+An animated character or object should be identified as being animated.
+
+NOTE – An animated character can sound like a real actor and could be confused for one.
+
+## **7.9 Guidance on parts of speech**
+
+### **7.9.1 Descriptive verbs**
+
+When possible, descriptive verbs should be used to reduce repetition of common verbs to enhance audience experience and understanding:
+
+EXAMPLE 1 – "To hold" can be more descriptively described as to grasp, to grip, to clasp, to clutch or to seize.
+
+EXAMPLE 2 – "To walk" can be more effectively described as to saunter, to glide, to hobble, to march, to stride, to stagger, to pace, etc.
+
+# Bibliography
+
+- [b-ITU-T T.701.11] Recommendation ITU-T T.701.11 (2020), *Guidance on text alternatives for images*.  
+Twin text with ISO/IEC 20071-11:2019, *Information technology – User interface component accessibility – Part 11: Guidance on text alternatives for images*.
+- [b-IEC 62731] IEC 62731:2018, *Text-to-speech for television – General requirements*. <https://webstore.iec.ch/publication/27131>
+- [b-ISO/IEC TS 20071-21] ISO/IEC TS 20071-21:2015, *Information Technology – User interface component accessibility – Part 21: Guidance on audio description*.
+
+
+
+## SERIES OF ITU-T RECOMMENDATIONS
+
+|                 |                                                                                                                                                           |
+|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Series A        | Organization of the work of ITU-T                                                                                                                         |
+| Series D        | Tariff and accounting principles and international telecommunication/ICT economic and policy issues                                                       |
+| Series E        | Overall network operation, telephone service, service operation and human factors                                                                         |
+| Series F        | Non-telephone telecommunication services                                                                                                                  |
+| Series G        | Transmission systems and media, digital systems and networks                                                                                              |
+| Series H        | Audiovisual and multimedia systems                                                                                                                        |
+| Series I        | Integrated services digital network                                                                                                                       |
+| Series J        | Cable networks and transmission of television, sound programme and other multimedia signals                                                               |
+| Series K        | Protection against interference                                                                                                                           |
+| Series L        | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant |
+| Series M        | Telecommunication management, including TMN and network maintenance                                                                                       |
+| Series N        | Maintenance: international sound programme and television transmission circuits                                                                           |
+| Series O        | Specifications of measuring equipment                                                                                                                     |
+| Series P        | Telephone transmission quality, telephone installations, local line networks                                                                              |
+| Series Q        | Switching and signalling, and associated measurements and tests                                                                                           |
+| Series R        | Telegraph transmission                                                                                                                                    |
+| Series S        | Telegraph services terminal equipment                                                                                                                     |
+| <b>Series T</b> | <b>Terminals for telematic services</b>                                                                                                                   |
+| Series U        | Telegraph switching                                                                                                                                       |
+| Series V        | Data communication over the telephone network                                                                                                             |
+| Series X        | Data networks, open system communications and security                                                                                                    |
+| Series Y        | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities                               |
+| Series Z        | Languages and general software aspects for telecommunication systems                                                                                      |
\ No newline at end of file
diff --git a/marked/T/T-REC-T.701.25-202203-I_PDF-E/14a22f23ced8ba1d63ece69861dbaacc_img.jpg b/marked/T/T-REC-T.701.25-202203-I_PDF-E/14a22f23ced8ba1d63ece69861dbaacc_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..94d45ee0d7450a0c276bffad33306ce1ec96de62
--- /dev/null
+++ b/marked/T/T-REC-T.701.25-202203-I_PDF-E/14a22f23ced8ba1d63ece69861dbaacc_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:c981deef08fa0ff69264e0a06c61f5dd291a362fb37303b3216e33a0ba5040e9
+size 5841
diff --git a/marked/T/T-REC-T.701.25-202203-I_PDF-E/raw.md b/marked/T/T-REC-T.701.25-202203-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..869c6b512f02957d6a8d65e25ff489571e1484b8
--- /dev/null
+++ b/marked/T/T-REC-T.701.25-202203-I_PDF-E/raw.md
@@ -0,0 +1,609 @@
+
+
+I n t e r n a t i o n a l   T e l e c o m m u n i c a t i o n   U n i o n
+
+**ITU-T**
+
+TELECOMMUNICATION  
+STANDARDIZATION SECTOR  
+OF ITU
+
+**T.701.25**
+
+(03/2022)
+
+SERIES T: TERMINALS FOR TELEMATIC SERVICES
+
+User interfaces - Accessibility and human factors
+
+# --- **Guidance on the audio presentation of text in videos, including captions, subtitles and other on-screen text**
+
+Recommendation ITU-T T.701.25
+
+## ITU-T T-SERIES RECOMMENDATIONS **TERMINALS FOR TELEMATIC SERVICES**
+
+|                                                          |                    |
+|----------------------------------------------------------|--------------------|
+| Facsimile – Framework                                    | T.0–T.19           |
+| Still-image compression – Test charts                    | T.20–T.29          |
+| Facsimile – Group 3 protocols                            | T.30–T.39          |
+| Colour representation                                    | T.40–T.49          |
+| Character coding                                         | T.50–T.59          |
+| Facsimile – Group 4 protocols                            | T.60–T.69          |
+| Telematic services – Framework                           | T.70–T.79          |
+| Still-image compression – JPEG-1, Bi-level and JBIG      | T.80–T.89          |
+| Telematic services – ISDN Terminals and protocols        | T.90–T.99          |
+| Videotext – Framework                                    | T.100–T.109        |
+| Data protocols for multimedia conferencing               | T.120–T.149        |
+| Telewriting                                              | T.150–T.159        |
+| Multimedia and hypermedia framework                      | T.170–T.189        |
+| Cooperative document handling                            | T.190–T.199        |
+| Telematic services – Interworking                        | T.300–T.399        |
+| Open document architecture                               | T.400–T.429        |
+| Document transfer and manipulation                       | T.430–T.449        |
+| Document application profile                             | T.500–T.509        |
+| Communication application profile                        | T.510–T.559        |
+| Telematic services – Equipment characteristics           | T.560–T.619        |
+| General multimedia application frameworks                | T.620–T.649        |
+| <b>User interfaces - Accessibility and human factors</b> | <b>T.700–T.799</b> |
+| Still-image compression – JPEG 2000                      | T.800–T.829        |
+| Still-image compression   JPEG XR                        | T.830–T.849        |
+| Still-image compression – JPEG-1 extensions              | T.850–T.899        |
+
+*For further details, please refer to the list of ITU-T Recommendations.*
+
+# Recommendation ITU-T T.701.25
+
+# Guidance on the audio presentation of text in videos, including captions, subtitles and other on-screen text
+
+## Summary
+
+Audiovisual content (such as video) often contain text, which cannot be easily accessed by a wide section of the audience. While captions/subtitles provide text alternatives to audio elements in audiovisual content, other on-screen text may have various functions. It can be part of the story (as a message written on a piece of paper by one of the characters) or it can provide additional information (such as graphs, emergency alerts or superimposed titles). Complementarily, audio description provides a description of audiovisual content auditorily, including captions/subtitles and other on-screen text if present and are of particular benefit to persons who, for different reasons, cannot access on-screen text. However, some users may only require captions/subtitles and other on-screen text to be made accessible as audio because they already have access to other visual content such as the images.
+
+Recommendation ITU-T T.701.25 provides guidance for audiovisual content producers, distributors and exhibitors on the audio presentation of captions/subtitles and other on-screen text. It acknowledges the relationship with existing access services such as audio description. While considering current implementations, as well as future possibilities suggested by research, and bearing in mind possible trade-offs between quantity and quality, this document positions itself for situations in which various access services coexist and users are given the choice to select those best suited to their needs.
+
+Recommendation ITU-T T.701.25 is twin with the published ISO/IEC TS 20071-25:2017 "Information Technology – User interface component accessibility – Part 25: Guidance on the audio presentation of text in videos, including captions, subtitles and other on-screen text" developed by ISO/IEC JTC1 SC35.
+
+## History
+
+| Edition | Recommendation | Approval   | Study Group | Unique ID*                                                                |
+|---------|----------------|------------|-------------|---------------------------------------------------------------------------|
+| 1.0     | ITU-T T.701.25 | 2022-03-29 | 16          | <a href="http://handle.itu.int/11.1002/1000/14973">11.1002/1000/14973</a> |
+
+## Keywords
+
+Accessibility, audio presentation of text in videos, captions, on-screen text, subtitles.
+
+---
+
+\* To access the Recommendation, type the URL <http://handle.itu.int/> in the address field of your web browser, followed by the Recommendation's unique ID. For example, <http://handle.itu.int/11.1002/1000/11830-en>.
+
+## FOREWORD
+
+The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis.
+
+The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics.
+
+The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1.
+
+In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC.
+
+## NOTE
+
+In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party.
+
+## INTELLECTUAL PROPERTY RIGHTS
+
+ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process.
+
+As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at <http://www.itu.int/ITU-T/ipr/>.
+
+© ITU 2022
+
+All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU.
+
+## Table of Contents
+
+|                                                                            | <b>Page</b> |
+|----------------------------------------------------------------------------|-------------|
+| 1 Scope .....                                                              | 1           |
+| 2 References.....                                                          | 1           |
+| 3 Definitions .....                                                        | 1           |
+| 3.1 Terms defined elsewhere .....                                          | 1           |
+| 3.2 Terms defined in this Recommendation.....                              | 2           |
+| 4 Abbreviations and acronyms .....                                         | 3           |
+| 5 Conventions .....                                                        | 3           |
+| 6 Framework and process considerations .....                               | 3           |
+| 6.1 General .....                                                          | 3           |
+| 6.2 Types of text in videos .....                                          | 4           |
+| 6.3 Types of audio presentations of text in videos .....                   | 5           |
+| 6.4 Creating and delivering audio presentations of text in videos .....    | 6           |
+| 6.5 Synchronization.....                                                   | 6           |
+| 6.6 Text-files.....                                                        | 7           |
+| 7 Guidance on the audio presentation of text in videos.....                | 7           |
+| 7.1 General considerations .....                                           | 7           |
+| 7.2 Developing the audio presentation of text in videos .....              | 8           |
+| 7.3 Levels of importance .....                                             | 8           |
+| 7.4 Guidance on identifying the audio presentation of text in videos ..... | 9           |
+| 7.5 Guidance on identifying characters .....                               | 9           |
+| 7.6 Guidance on text and speech adjustments .....                          | 9           |
+| Bibliography.....                                                          | 11          |
+
+## **Introduction**
+
+Videos are omnipresent in our digital society and are used to inform, educate and entertain audiences. Videos often contain text, which cannot be easily accessed by a wide section of the audience. This text includes captions/subtitles and other on-screen text that is part of the visual content.
+
+Captions/subtitles provide text alternatives to audio elements. Other on-screen text may have various functions. It can be part of the story, as a message written on a piece of paper by one of the characters. It can also provide additional information, such as graphs, emergency alerts or superimposed titles.
+
+Persons who, for different reasons, cannot access on-screen text will benefit from an audio presentation. This oral rendering is often part of audio description (see [b-ITU-T T.701.21], an access service providing a description of audiovisual content auditorily, including captions/subtitles and other on-screen text if present. However, some users may only require captions/subtitles and other on-screen text to be made accessible because they already have access to other visual content such as the images.
+
+This Recommendation provides guidance for video producers, distributors and exhibitors on the audio presentation of captions/subtitles and other on-screen text. It acknowledges the relationship with existing access services such as audio description. While considering current implementations, as well as future possibilities suggested by research, and bearing in mind possible trade-offs between quantity and quality, this document positions itself for situations in which various access services coexist and users are given the choice to select those best suited to their needs.
+
+# **Recommendation ITU-T T.701.25**
+
+# **Guidance on the audio presentation of text in videos, including captions, subtitles and other on-screen text**
+
+# **1 Scope**
+
+This Recommendation provides recommendations on the audio presentation of captions/subtitles and other on-screen text for use in all types of videos regardless of the language and technology being used to transmit and present the recorded or live video.
+
+This Recommendation applies to making captions/subtitles and other on-screen text accessible to users with various needs, including but not limited to people with learning and reading disabilities, people with cognitive disabilities, people who are blind or have low vision, older people, and non-native language speakers. It does not apply to captions/subtitles or other on-screen text whose content is already provided in the soundtrack in a language and a way users can access.
+
+This Recommendation provides guidance on spoken captions/subtitles as a stand-alone access service, but it also provides guidance on how to integrate spoken captions/subtitles, other spoken on-screen text and audio description, if needed, in different types of videos.
+
+NOTE 1 – Extensive guidance on audio description is provided in [b-ITU-T T.701.21].
+
+This Recommendation does not consider the devices or transmission mechanisms used to deliver and play the content or the audio presentation of text in videos. These devices include, but are not limited to televisions, computers, wireless devices, projection equipment, digital versatile disk (DVD) and home cinema equipment, cinema equipment and other forms of user interface technology. Therefore, this Recommendation does not consider transcoding files for the various video and audio outputs.
+
+NOTE 2 – Technical matters of transmission and distribution are covered by other international standards (e.g., MPEG standards and other technical international standards such as [b-IEC 62731]).
+
+This Recommendation acknowledges the various needs and preferences of users, as well as the different approaches to the audio presentation of text in videos.
+
+It applies to audio presentations intended to be heard simultaneously along with the original video.
+
+# **2 References**
+
+The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation.
+
+None.
+
+# **3 Definitions**
+
+## **3.1 Terms defined elsewhere**
+
+None.
+
+## 3.2 Terms defined in this Recommendation
+
+This Recommendation defines the following terms:
+
+### 3.2.1 General terms
+
+**3.2.1.1 programme:** Complete unit of a recorded or live video.
+
+**3.2.1.2 programme category:** Classification of programmes.
+
+NOTE – Programme categories are not necessarily mutually exclusive.
+
+EXAMPLE – Programme categories include documentary, news and information, and drama.
+
+**3.2.1.3 video:** Combination of audio and visual content presented together in a synchronized manner via ICT.
+
+NOTE – While the visual content is often presented using a screen, it might also be presented via other technologies, e.g., a projected hologram.
+
+### 3.2.2 Audio-specific terms
+
+**3.2.2.1 audio description; descriptive audio:** Audiovisual content described in an audio modality.
+
+NOTE 1 – Audio description can also be used to describe locations, directions and objects.
+
+NOTE 2 – Audio description can be used to describe sound not easily identified or coming from an unknown source or location.
+
+**3.2.2.2 narrator:** Person(s) and/or technology which voices the alternative audio information.
+
+NOTE 1 – Alternative audio information includes audio description and/or spoken captions/subtitles and/or spoken on-screen text.
+
+NOTE 2 – In audio description, narrators are also referred to as describers or audio describers.
+
+**3.2.2.3 spoken captions/subtitles; audio captions/subtitles:** Captions/subtitles that are voiced over the audiovisual content.
+
+NOTE – In this Recommendation, the term "spoken captions/subtitles" will be used.
+
+**3.2.2.4 spoken on-screen text:** Text, other than captions/subtitles, that is voiced over the audiovisual content.
+
+### 3.2.3 Language of presentation terms
+
+**3.2.3.1 original language:** Language in which audiovisual content is produced.
+
+**3.2.3.2 dubbing:** Secondary audio version of a video produced in a language other than the original language of the video and timed to match the voicing of the original actors.
+
+NOTE – The secondary audio version is lip-synchronized and replaces the original dialogue, which cannot be heard.
+
+**3.2.3.3 voice-over:** Secondary audio version of a video produced in a language other than the original language of the video which overlaps with the voicing of the original actors.
+
+NOTE – The secondary audio version is not lip-synchronized and does not replace the original dialogue, which can still be heard.
+
+**3.2.3.4 captions/subtitles:** Transcription or translation of audio content visually presented together with the content.
+
+NOTE 1 – Transcriptions or translations include speech and/or non-speech information.
+
+NOTE 2 – Transcriptions or translations are often suitable for use as an alternative or a complement to the audio content.
+
+### 3.2.4 Production terms
+
+**3.2.4.1 pre-mixed production:** Process that involves delivering alternative audio information together with the audio stream of the video as one single audio track.
+
+NOTE 1 – Although pre-mixed is used in the definition to refer to the audio mix, it can also refer to a production process in which the original audio (including both the soundtrack and the dialogues), the alternative audio information in the video and the original visual content are delivered together.
+
+NOTE 2 – Pre-mixed productions are also referred to as broadcast-mixed productions.
+
+**3.2.4.2 receiver-mixed production:** Process that involves delivering alternative audio information separately from the audio stream of the video and having them mixed in a device controlled by the user.
+
+NOTE – Alternative audio information can be delivered to the user or be downloaded or streamed from the Internet as separate services or as services mixed in different combinations.
+
+# 4 Abbreviations and acronyms
+
+This Recommendation uses the following abbreviations and acronyms:
+
+DVD Digital Versatile Disk
+
+SDH Subtitles for the Deaf and Hard-of-hearing
+
+# 5 Conventions
+
+None.
+
+# 6 Framework and process considerations
+
+## 6.1 General
+
+### 6.1.1 Alternate names for the audio presentation of text in videos
+
+Terms used in this Recommendation vary according to country, language, region, video content, and type of text in videos.
+
+They include audio subtitles, spoken subtitles, spoken captions, audio captions, to refer to the audio presentation of captions/subtitles. For the purpose of this Recommendation, these terms are synonymous, as defined in clause 3.
+
+They include audio text, to refer to the audio presentation of all text in videos.
+
+NOTE – In some jurisdictions, there are precise usages defined for one or more of these terms. Individuals can consult their own country's regulations for the locally appropriate terminology.
+
+### 6.1.2 Motivation for the audio presentation of text in videos
+
+Videos are everywhere in our society, and they often contain text such as captions/subtitles and other on-screen text.
+
+This is particularly the case in countries or regions where captions/subtitles are used to translate content into another language.
+
+All these texts share two features: they are visual and at the same time they are verbal. Users who might not be able to fully access the content include:
+
+- users who cannot access the visual elements: persons with sensorial disabilities such as blind and visually impaired audiences, and also persons who for other reasons (for instance, not being in front of the video display) cannot see the visuals; and
+- users with difficulties to access the written verbal content.
+
+NOTE 1 – Reading is a complex cognitive process and, very often, the coexistence of visual stimuli and the speed at which written text is presented makes it difficult for certain users to access written text: this includes persons with reading difficulties caused by a lack of reading ability, dyslexia or cognitive diversity, but also includes children, the elderly and people learning a new language.
+
+Not being able to access text in videos has a direct impact on the understanding and enjoyment of videos. It also implies that certain users are excluded from educational, cultural and social contexts (e.g., when a movie is discussed by colleagues in informal contexts).
+
+Facilitating access to text in videos improves the viewing experience in terms of comprehension and enjoyment, and guarantees access in critical emergency situations where information is provided via text.
+
+Providing an audio presentation of text in videos enhances access to video content.
+
+NOTE 2 – While nowadays the audio presentation of text generally contains spoken captions/subtitles only, users also request the audio presentation of other on-screen text.
+
+NOTE 3 – While audio description usually includes an audio presentation of all relevant captions/subtitles and other on-screen text, some users only require written text to be made accessible since they already have access to the visual content.
+
+## **6.2 Types of text in videos**
+
+### **6.2.1 Captions/subtitles**
+
+Video content can include:
+
+- a) text which provides a translation of the original language of the video, addressing users who do not understand the spoken words;
+- b) text which provides a translation of the original language of the video plus additional features (character identification, sound effects indications, etc.), addressing users who do not understand the language and cannot access the audio;
+- c) text which provides a transcription of the original language, addressing users who do not have access to the audio; the transcription can be a verbatim or an edited version of the spoken words, including additional features (character identification, sound effects indications, etc.);
+- d) text which provides a transcription of the original language, addressing users who for various reasons have difficulties understanding the spoken words (e.g., strong dialect, bad quality audio).
+
+Depending on function, users, country, language, and region, this text can be referred to as captions, subtitles, subtitles for the deaf and hard-of-hearing (SDH), intralingual or same-language subtitles, and interlingual subtitles.
+
+An audio presentation of captions/subtitles should be provided only when the original dialogue cannot be understood by the user.
+
+### **6.2.2 Other on-screen text**
+
+Video content can include:
+
+- a) logos, which can display text often indicating the name of the company;
+- b) credits: opening credits present a selection of the main production and cast members, whilst end credits include a more extensive list with additional information;
+- c) superimposed titles, which are used to present the title of the video, often at the beginning, or to insert additional information such as the spatio-temporal settings (some videos also include intertitles);
+- d) scrolling texts included at the beginning of a video (e.g., to introduce an episode);
+
+- e) graphs, tables and other figures including text;
+- f) scrolling tickers (crawlers/slides), providing emergency alerts, breaking news, running messages from social media, and other information; and
+- g) popping-up text messages or captions.
+
+Elements which are part of the story being told in the video can also contain text that is important to be made accessible.
+
+EXAMPLE 1 – An object, a piece of paper or a computer screen which is part of a movie can include text.
+
+An audio presentation may not be needed when the information provided by the on-screen text is already delivered auditorily.
+
+EXAMPLE 2 – If a news presenter already delivers orally the information included in text presented on screen, there is no need to provide an audio presentation of such text.
+
+Text in videos can use colour, type font, positioning, size and other effects for creative and artistic purposes, adding additional layers of meaning. It is important for these visual elements to be transmitted, if possible, to users who do not have access to the visuals.
+
+## **6.3 Types of audio presentations of text in videos**
+
+### **6.3.1 Live and recorded spoken captions/subtitles and spoken on-screen text**
+
+Live spoken captions/subtitles and spoken on-screen text can be used for live and recorded programmes. They involve creating and delivering audio presentations of text in videos in real time along with the delivery of the original video.
+
+Live productions are typically distributed initially in real time, but might be recorded for later redistribution. In this case, recorded spoken captions/subtitles and spoken on-screen text should be prioritized.
+
+NOTE – Although being transmitted live, captions/subtitles can sometimes be semi-prepared when there is a script available. This is known as semi-live captioning/subtitling or as-live captioning/subtitling. The preparation method (live/semi-live) will have an impact on the quality of the caption/subtitles and, consequently, on its audio presentation.
+
+Recorded spoken captions/subtitles and spoken on-screen text are used for recorded programmes and involve creating and recording the audio presentation of text in videos prior to delivery. They allow for careful planning and evaluation before delivery, and are therefore recommended where possible.
+
+### **6.3.2 Pre-mixed and receiver-mixed productions**
+
+In pre-mixed productions, the audio presentation of text in videos is created and mixed with the original audio before its distribution.
+
+In receiver-mixed productions, there are different possibilities:
+
+- a) The audio presentation of text in videos is created before distribution and mixed in the user device.
+
+NOTE 1 – The audio presentation can also be retrieved from the Internet.
+
+- b) Text content is sent to the user device, where it is converted into an audio presentation by a text-to-speech system, allowing users to select the synthetic voice of their choice.
+
+NOTE 2 – Text content can also be retrieved from the Internet.
+
+NOTE 3 – Receiver-mixed productions allow users with different needs to access the same video simultaneously.
+
+EXAMPLE – One user accesses the video with the audio presentation of text using headphones while another user watches it in the same room without the audio presentation of text.
+
+## **6.4 Creating and delivering audio presentations of text in videos**
+
+### **6.4.1 Narrator preparation**
+
+The audio presentation of text in videos may be delivered by a human voice or by a synthetic voice or a combination of both.
+
+The narrator, be it a person or a technology, should have the following:
+
+- a) good native language skills;
+- b) the ability to articulate.
+
+When using synthetic voices, special care should be taken in their selection. Voice quality, naturalness and reading speed vary depending on the synthetic voices. Availability and quality of synthetic voices vary depending on the language.
+
+NOTE 1 – User testing indicates that human voices are generally preferred in certain programme categories, especially in drama, but synthetic voices are also accepted and might be prioritized, especially when users are familiarized with them. Research indicates that, when speech synthesis is used, it might avoid confusing the human voice of the original dialogue with the synthetic voice.
+
+NOTE 2 – Synthetic voices reading split subtitles (i.e., when one sentence is divided into two or more subtitles) might produce unnatural pauses that can affect the comprehension or enjoyment of users.
+
+### **6.4.2 Volume**
+
+The audio presentation of text in video should be prepared in sound objects so that users can adjust the volume of the original audio and the volume of the audio presentation of text in video separately. This is only possible in receiver-mixed productions.
+
+In pre-mixed productions, where one single audio track is received by the user, the volume of the audio presentation of text in videos should have a good mix with the volume of the original audio, including both the dialogues and the soundtrack.
+
+### **6.4.3 Audio quality**
+
+Cut off, microphone noise, background noise, levels between the audio presentation of text in videos and the original soundtrack, and other audio factors should be mixed and filtered so as to guarantee comprehension and enjoyment by users.
+
+### **6.4.4 Inclusion of users in creating the audio presentation of text in videos**
+
+The full range of users should be included in the process of creating audio of text in videos where possible.
+
+NOTE – This can take the form of focus groups, employment of users as marketers or community consultants. Users might also be included in situations where stakeholder groups are actively involved in the creation and marketing processes.
+
+### **6.4.5 Inclusion of users in evaluating the audio presentation of text in videos**
+
+If evaluation is part of the process of creating audio presentations of text in videos, representative users should be involved.
+
+NOTE 1 – It is important to evaluate recorded spoken captions/subtitles and spoken on-screen text prior to delivery wherever possible.
+
+NOTE 2 – It is important for evaluations to focus on the understandability.
+
+Users' feedback should be systematically registered and taken into account to improve the process.
+
+## **6.5 Synchronization**
+
+Spoken captions/subtitles should generally be delivered in synchronization with the captions/subtitles displayed on screen. They should also be synchronized with visual action such as
+
+body language, where possible, and take into account audio elements such as music and other sounds.
+
+When spoken captions/subtitles are delivered in synchronization with the captions/subtitles on screen, the original dialogue might be heard on the background or not. When the original dialogue is not heard, the final effect is similar to dubbing. When the original dialogue is heard underneath, a voice-over effect is achieved.
+
+NOTE – Research on user preferences is still needed.
+
+Spoken on-screen text may be delivered in a synchronized or a non-synchronized manner.
+
+EXAMPLE – Where time constraints prevent reading all the opening credits in a movie in a synchronous way, a selection is provided either before or after they appear on screen.
+
+Credits should be read at a normal pace without rushing, and effort should be made to include as many as possible.
+
+## **6.6 Text-files**
+
+Captions/subtitles can be produced in a way that they are always visible (open) or in a way that they can be turned on and off by the user (closed). Open captions/subtitles are generally burned in the video.
+
+For the purpose of accessibility, captions/subtitles and other on-screen text should be included as separate text-files, as this is the best option for converting text into audio.
+
+# **7 Guidance on the audio presentation of text in videos**
+
+## **7.1 General considerations**
+
+### **7.1.1 Different strategies**
+
+Different strategies apply when:
+
+- a) creating separate tracks for the spoken captions/subtitles, for the spoken on-screen text, and for the audio description, which can be used independently or combined to suit the needs of diverse users;
+- b) integrating the spoken captions/subtitles and spoken on-screen text in the audio description.
+
+NOTE 1 – Although the first option caters for the needs of a wider section of the population, both scenarios are considered in this Recommendation when describing the strategies used.
+
+NOTE 2 – The integration of spoken on-screen text in the spoken captions/subtitles track is easier to achieve when a human narrator is used.
+
+### **7.1.2 User considerations**
+
+The following aspects are important to consider:
+
+- a) At the beginning of each programme, a verbal and a visual notification should be presented to make users aware that an audio presentation of text is available.
+- b) The availability of the audio presentation of text in a programme should be identified by a standardized logo, both on the screen and in any media where it is advertised.  
+NOTE 1 – It is recognized that logos might vary from country to country. It is important that logos are as consistent across as many jurisdictions as possible.
+- c) Users should be easily able to access information (both in real time and in advance) that identifies when the audio presentation of text is available and for which programmes.
+- d) Users should be provided with an easy to use means of selecting and changing between presenting:
+
+- 1) spoken captions/subtitles;
+- 2) spoken on-screen text;
+- 3) audio description;
+- 4) any combination of the previous access services;
+- 5) no access services.
+
+NOTE 2 – Audio description traditionally includes a verbal rendition of text in videos. However, when mixing traditional audio descriptions with the audio presentation of text, overlapping and inconsistencies might occur. This is why an audio description that does not include the audio presentation of text is more suitable when interacting with spoken captions/subtitles and spoken on-screen text. This caters for the needs and preferences of a wider sector of the population.
+
+### **7.1.3 Availability across technologies**
+
+The audio presentation of text in videos should be available regardless of the technology being used to transmit and/or present the original content.
+
+NOTE 1 – Some technologies used for transmission include cable, satellite, Internet, DVD, stream, catch up.
+
+NOTE 2 – Some technologies used for presentation include television, computer, smart phone, tablet, and cinema.
+
+### **7.1.4 Consistency within a video and programme series**
+
+The style of the audio presentation of text should be consistent throughout a video and the programmes in a series.
+
+## **7.2 Developing the audio presentation of text in videos**
+
+### **7.2.1 Clarity in the audio presentation of text in videos**
+
+The audio presentation of text in videos should be clearly voiced in a manner that can be understood by its intended users.
+
+### **7.2.2 Reading/delivering the audio presentation of text in videos**
+
+Spoken captions/subtitles can be delivered in an acted or a non-acted way. Voices with different accents can also be used.
+
+NOTE 1 – User preferences concerning emotional narrations and accents vary.
+
+Different voices matching the gender and the age of the original voices should be used where possible.
+
+NOTE 2 – More research is needed, especially in countries where voice-over is delivered by a single narrator.
+
+## **7.3 Levels of importance**
+
+Too much information can interfere with a user's ability to understand the programme.
+
+When various types of text coexist simultaneously in a video, it may not be possible to include all the text in the audio presentation.
+
+EXAMPLE 1 – A video can present different types of text simultaneously: for instance, subtitles, a scrawling text and a graph.
+
+Levels of importance should be determined by the persons responsible for developing the audio presentation of text in videos and will vary between different contexts. These levels are: essential information, significant information, helpful information, and unhelpful information. The levels are based on clause 4.4 of [b-ITU-T T.701.21], but "unhelpful information" in this Recommendation replaces "irrelevant information" in [b-ITU-T T.701.21].
+
+Levels of importance should be used to select the text in videos to be included in the audio presentation.
+
+EXAMPLE 2 – An emergency alert is considered essential information and is prioritized over other text.
+
+NOTE – It is useful to include users in making this decision where possible.
+
+## **7.4 Guidance on identifying the audio presentation of text in videos**
+
+The audio presentation of text in videos should be clearly identifiable from other audio content.
+
+Users should also be able to distinguish the types of text in videos (captions/subtitles, logos, superimposed titles, credits, emergency alerts, etc.) being presented.
+
+This can be achieved by using:
+
+- a) Voices: Different voices are generally used to distinguish between audio description and the audio presentation of text in videos.
+
+EXAMPLE – Two voices, male and female, are used. One is used to read the audio presentation of text in videos and one to read the audio description script.
+
+- b) Prosody: When only one voice is available, changing the prosody can help the user infer that a text is being read.
+
+NOTE 1 – Although the quality of synthetic voices is improving, prosody is still a commonly reported issue.
+
+- c) Descriptive words: A descriptive word indicating the type of text that will be read can also be used.
+
+EXAMPLE – The presentation of text is preceded by a phrase to identify the type of text such as: "a caption reads", "subtitle", "text message" or "emergency alert".
+
+NOTE 2 – While the use of earcons (audio signals) as an identification mechanism has been proposed, there is insufficient research to standardize their use at the present time.
+
+## **7.5 Guidance on identifying characters**
+
+Different voices may be used to distinguish between various characters in a video.
+
+When only one voice is used, prosody helps distinguish between various characters in a video.
+
+Characters can also be identified by including their name before reading the caption/subtitle.
+
+EXAMPLE 1 – "Mary: I like going to the cinema".
+
+NOTE 1 – When captions/subtitles are integrated in the audio description, they can be rendered as direct speech or indirect speech, indicating in both cases the character who voices the text.
+
+EXAMPLE 2 – "It's raining, says Mary" or "Mary says that it's raining".
+
+NOTE 2 – When spoken captions/subtitles and audio description are integrated, the audio description can help the user infer who is speaking (e.g., indicating the direction of the gaze), in place of an explicit identification of the character.
+
+The audio presentation of text in videos with a voice-over effect (i.e., the original voice is heard underneath) also contributes to character identification.
+
+## **7.6 Guidance on text and speech adjustments**
+
+When numerous texts are present on screen, rendering all of them literally might cause synchronization problems.
+
+The spoken caption/subtitle should not be longer than the span of time during which the caption/subtitle is presented on screen, to avoid overlapping with the subsequent caption/subtitle. Overlaps with the audio description should be avoided. If the audio presentation of text is
+
+continually longer than the text presented on screen, the lack of synchronization will accumulate and soon affect comprehensibility.
+
+Fade in and fade out should be taken into consideration when calculating the reading time available for synchronisation purposes.
+
+NOTE 1 – Numbers (for instance, years) and abbreviations normally take longer to read out and can cause synchronization issues.
+
+Strategies to overcome synchronization issues include:
+
+- a) increasing the reading speed;
+
+NOTE 2 – While higher reading speeds can negatively affect some users' comprehension, other users might be used to faster reading speeds.
+
+NOTE 3 – Synthetic voices differ in their reading speeds, and the reading speeds of each voice can be altered. Ongoing studies indicate that adjusting the reading speed of spoken captions/subtitles only in longer utterances so that they fit in the time slot might be a suitable solution.
+
+- b) altering the text: text in videos can be shortened, rephrased or expanded; it can even be omitted if the content is already transmitted via other means.
+
+NOTE 4 – When converting captions/subtitles into spoken captions/subtitles, text can also be adapted to resemble oral language wording.
+
+NOTE 5 – In some cases, it is not possible or even desirable to provide a literal and synchronized rendering of the text in videos.
+
+EXAMPLE – Users might prefer to listen to a song rather than to its audio presentation. Possible solutions would be omitting the song text or fitting adjusted spoken captions/subtitles when convenient.
+
+# Bibliography
+
+- [b-ITU-T T.701.21] Recommendation ITU-T T.701.21 (2022), *Guidance on audio description*.
+- [b-IEC 62731] IEC 62731:2013, *Text-to-speech for television – General requirements*.
+- [b-ISO/IEC TS 20071-25] ISO/IEC TS 20071-25:2017, *Information Technology – User interface component accessibility – Part 25: Guidance on the audio presentation of text in videos, including captions, subtitles and other on-screen text*.
+
+
+
+
+
+## SERIES OF ITU-T RECOMMENDATIONS
+
+|                 |                                                                                                                                                           |
+|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Series A        | Organization of the work of ITU-T                                                                                                                         |
+| Series D        | Tariff and accounting principles and international telecommunication/ICT economic and policy issues                                                       |
+| Series E        | Overall network operation, telephone service, service operation and human factors                                                                         |
+| Series F        | Non-telephone telecommunication services                                                                                                                  |
+| Series G        | Transmission systems and media, digital systems and networks                                                                                              |
+| Series H        | Audiovisual and multimedia systems                                                                                                                        |
+| Series I        | Integrated services digital network                                                                                                                       |
+| Series J        | Cable networks and transmission of television, sound programme and other multimedia signals                                                               |
+| Series K        | Protection against interference                                                                                                                           |
+| Series L        | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant |
+| Series M        | Telecommunication management, including TMN and network maintenance                                                                                       |
+| Series N        | Maintenance: international sound programme and television transmission circuits                                                                           |
+| Series O        | Specifications of measuring equipment                                                                                                                     |
+| Series P        | Telephone transmission quality, telephone installations, local line networks                                                                              |
+| Series Q        | Switching and signalling, and associated measurements and tests                                                                                           |
+| Series R        | Telegraph transmission                                                                                                                                    |
+| Series S        | Telegraph services terminal equipment                                                                                                                     |
+| <b>Series T</b> | <b>Terminals for telematic services</b>                                                                                                                   |
+| Series U        | Telegraph switching                                                                                                                                       |
+| Series V        | Data communication over the telephone network                                                                                                             |
+| Series X        | Data networks, open system communications and security                                                                                                    |
+| Series Y        | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities                               |
+| Series Z        | Languages and general software aspects for telecommunication systems                                                                                      |
\ No newline at end of file
diff --git a/marked/T/T-REC-T.71-198811-I_PDF-E/raw.md b/marked/T/T-REC-T.71-198811-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..ac0354d59aedfc41efe3e93f5dc1d0f89c37c0ff
--- /dev/null
+++ b/marked/T/T-REC-T.71-198811-I_PDF-E/raw.md
@@ -0,0 +1,299 @@
+
+
+![ITU logo: a globe with the letters ITU and a lightning bolt symbol.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg)
+
+ITU logo: a globe with the letters ITU and a lightning bolt symbol.
+
+INTERNATIONAL TELECOMMUNICATION UNION
+
+**ITU-T**
+
+TELECOMMUNICATION  
+STANDARDIZATION SECTOR  
+OF ITU
+
+**T.71**
+
+**TERMINAL EQUIPMENT AND PROTOCOLS FOR  
+TELEMATIC SERVICES**
+
+---
+
+**LINK ACCESS PROTOCOL  
+BALANCED (LAPB) EXTENDED  
+FOR HALF - DUPLEX PHYSICAL LEVEL  
+FACILITY**
+
+**ITU-T Recommendation T.71**
+
+(Extract from the *Blue Book*)
+
+---
+
+# NOTES
+
+1 ITU-T Recommendation T.71 was published in Fascicle VII.5 of the *Blue Book*. This file is an extract from the *Blue Book*. While the presentation and layout of the text might be slightly different from the *Blue Book* version, the contents of the file are identical to the *Blue Book* version and copyright conditions remain unchanged (see below).
+
+2 In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+## Recommendation T.71
+
+# LINK ACCESS PROTOCOL BALANCED (LAPB) EXTENDED FOR HALF-DUPLEX PHYSICAL LEVEL FACILITY
+
+(Malaga-Torremolinos, 1984; amended at Melbourne, 1988)
+
+The CCITT,
+
+*considering*
+
+(a) that the Teletex service will be introduced in different types of networks, i.e. circuit switched public data networks (CSPDN), packet switched public data networks (PSPDN) and public switched telephone networks (PSTN);
+
+(b) that depending on the service provided by the physical level, the link level procedures may have to cater for a half-duplex transmission facility;
+
+(c) that some Administrations are considering the provision of a Teletex service with a half-duplex transmission facility on the PSTN;
+
+(d) that modems according to Recommendation V.26 *bis* are suitable for half-duplex transmission at 2400 bit/s on PSNTs,
+
+*unanimously declares*
+
+that this Recommendation defines the link level procedure using LAPB extended for half-duplex physical level service.
+
+# 1 Introduction
+
+## 1.1 General
+
+1.1.1 Figure 1/T.71 shows the half-duplex transmission module (HDTM) for extending the use of LAPB for operation of Teletex terminals connected to the PSTN where use of half-duplex 2400 bit/s modems is planned. This is referred to in Recommendation T.70 as LAPX.
+
+![Diagram of the Teletex data link layer for PSTN based on LAPB plus the half-duplex transmission module (HDTM).](2a16bc72fa4d0150523532baaa0ecfad_img.jpg)
+
+The diagram illustrates the Teletex data link layer for PSTN. It shows a vertical stack of two protocol modules: LAPB (Link Access Protocol Balanced) at the top and HDTM (Half-Duplex Transmission Module) at the bottom. These two modules are enclosed within a dashed rectangular box. A vertical line passes through the center of both modules, representing the data flow. To the right of the dashed box, a vertical double-headed arrow spans the height of both the LAPB and HDTM modules, with the label 'LAPB extended' positioned to its right. Below the dashed box, the text 'CCITT-54060' is written.
+
+Diagram of the Teletex data link layer for PSTN based on LAPB plus the half-duplex transmission module (HDTM).
+
+FIGURE 1/T.71
+
+**Teletex data link layer for PSTN based on LAPB plus  
+the half-duplex transmission module (HDTM)**
+
+1.1.2 Before the HDTM begins operation the physical circuit must be established by the appropriate PSTN call control procedures. The operation of the HDTM is such that the calling DTE will initially have the right to transmit. For the link addressing conventions refer to Recommendation T.70.
+
+## 1.2 Architecture
+
+### 1.2.1 Level relationships
+
+It is an objective to avoid modification of the definition of LAPB in order to adapt it for half-duplex operation. However, there is a functional requirement that the HDTM inhibit LAPB from sending frames during certain phases of the half-duplex procedure. The means of accomplishing this functional requirement is not defined.
+
+The logical relationships between LAPB, the HDTM and the physical level are as shown in Figure 2/T.71.
+
+![Diagram showing the logical relationships between LAPB, HDTM, and Physical level. LAPB is at the top, HDTM in the middle, and Physical level at the bottom. Arrows indicate data flow: T (Transmit) from LAPB to HDTM, R (Receive) from HDTM to LAPB, C (Control) from HDTM to LAPB, and S (Status) from LAPB to HDTM. Ellipses between HDTM and Physical level indicate intermediate layers.](f0bae10b54c4f3cf8d0e33f5e2fb7cfa_img.jpg)
+
+CCITT-54070
+
+|   |                         |   |                   |
+|---|-------------------------|---|-------------------|
+| T | Transmit data functions | C | Control functions |
+| R | Receive data functions  | S | Status functions  |
+
+Diagram showing the logical relationships between LAPB, HDTM, and Physical level. LAPB is at the top, HDTM in the middle, and Physical level at the bottom. Arrows indicate data flow: T (Transmit) from LAPB to HDTM, R (Receive) from HDTM to LAPB, C (Control) from HDTM to LAPB, and S (Status) from LAPB to HDTM. Ellipses between HDTM and Physical level indicate intermediate layers.
+
+FIGURE 2/T.71
+
+#### Level relationships
+
+### 1.2.2 Control (C) and status (S) functions
+
+The following logical functions are defined to describe the interactions between LAPB and the HDTM:
+
+Control <TERM>
+
+- Revert to the HDTM idle state since LAPB has entered the disconnected phase (equivalent to ADM of HDLC).
+
+Status <OP-T>
+
+- LAPB is enabled to send frames.
+
+Status <INOP-T>
+
+- LAPB is inhibited from sending frames.
+
+# 2 State diagram and descriptions
+
+### 2.1 State diagram
+
+The state diagram shown in Figure 3/T.71 describes the procedure for controlling the right to transmit. The number in each ellipse is the state reference number.
+
+![State diagram for controlling the right to transmit, showing five states: 1 (Half-duplex sending state), 2 (Wait for receiving state), 3 (Half-duplex receiving state), 4 (Wait for sending state), and 0 (Idle state). Transitions are labeled with actions like 'Send right to transmit', 'Disconnect sending DTE', 'Initialize called DTE', 'Receive confirmation', 'Seize right to transmit', 'Reset from any state', and 'Receive right to transmit'.](aa81b9b80bd1e3d723922b3a033564a2_img.jpg)
+
+```
+graph TD
+    1((1  
+Half-duplex  
+sending state))
+    2((2  
+Wait for  
+receiving state))
+    3((3  
+Half-duplex  
+receiving state))
+    4((4  
+Wait for  
+sending state))
+    0((0  
+Idle state))
+
+    1 -- "Send right to transmit" --> 2
+    1 -- "Disconnect sending DTE" --> 0
+    1 -- "Send confirmation" --> 4
+    0 -- "Initialize called DTE" --> 2
+    0 -- "Initialize calling DTE" --> 4
+    2 -- "Receive confirmation" --> 3
+    3 -- "Seize right to transmit" --> 2
+    3 -- "Receive right to transmit" --> 4
+    3 -- "Disconnect receiving DTE" --> 0
+    2 -- "Reset from any state" --> 0
+    4 -- "Reset from any state" --> 0
+```
+
+CCITT-54080
+
+State diagram for controlling the right to transmit, showing five states: 1 (Half-duplex sending state), 2 (Wait for receiving state), 3 (Half-duplex receiving state), 4 (Wait for sending state), and 0 (Idle state). Transitions are labeled with actions like 'Send right to transmit', 'Disconnect sending DTE', 'Initialize called DTE', 'Receive confirmation', 'Seize right to transmit', 'Reset from any state', and 'Receive right to transmit'.
+
+FIGURE 3/T.71
+
+State diagram
+
+## 2.2 State definitions
+
+### 2.2.1 Idle state (state 0)
+
+The DTE is in an inactive state. This is the initial state prior to call establishment and the final state after call termination.
+
+#### 2.2.2 *Half-duplex sending state (state 1)*
+
+The DTE is in a half-duplex sending state, so that all signals generated by LAPB are passed to the physical level.
+
+### 2.2.3 *Wait for receiving state (state 2)*
+
+The DTE is awaiting indication that the remote DTE has entered the half-duplex sending state. No signals generated by LAPB are passed to the physical level.
+
+### 2.2.4 *Half-duplex receiving state (state 3)*
+
+The DTE is in a half-duplex receiving state, so that no signals generated by LAPB are passed to the physical level. The remote DTE is considered to be in the half-duplex sending state.
+
+### 2.2.5 *Wait for sending state (state 4)*
+
+The DTE is awaiting indication of the availability of the physical level for transmission of frames to the remote DTE. All signals generated by LAPB are passed to the physical level, but LAPB is inhibited from sending frames.
+
+### 2.3 *Table of transitions between states*
+
+Table 1/T.71 shows the events that cause transitions from one state to another, along with any resulting actions. This shows a generalized description of the operation of the HDTM.
+
+### 2.4 *State definitions expressed in terms applicable to a modem interface*
+
+The following definitions apply to the use of the HDTM with the V.26 *bis* modem interface, as an example.
+
+### 2.4.1 *Idle state (state 0)*
+
+Circuit 107 is OFF.
+
+### 2.4.2 *Half-duplex sending state (state 1)*
+
+Circuit 105, circuit 106 and circuit 107 are ON. LAPB is connected to circuit 103 and enabled to send frames.
+
+#### 2.4.3 *Wait for receiving state (state 2)*
+
+Circuit 107 is ON, circuit 105 is OFF. LAPB is inhibited from sending frames and disconnected from circuit 103, which is held in the binary 1 condition. Timer T is running.
+
+#### 2.4.4 *Half-duplex receiving state (state 3)*
+
+Circuit 107 is ON, circuit 105 is OFF. LAPB is inhibited from sending frames and disconnected from circuit 103, which is held in the binary 1 condition.
+
+#### 2.4.5 *Wait for sending state (state 4)*
+
+Circuit 105 and circuit 107 are ON, and circuit 106 is OFF. LAPB is connected to circuit 103 but is inhibited from sending frames.
+
+### 2.5 *Table of transitions between states expressed in terms applicable to a modem interface*
+
+Table 2/T.71 shows, in terms of the V.26 *bis* modem interface, the events that cause a state transition and the resulting action(s).
+
+### 2.6 Timer T
+
+This timer is used to recover from an apparent failure of the remote DTE to take the right to transmit. To avoid a contention condition during this recovery process, different values of timer T are to be used by the called and calling DTE. A calling DTE uses the value  $T_a$  and a called DTE uses the value  $T_b$ .
+
+The values of  $T_a$  and  $T_b$  are system parameters and must be studied further in relationship to interworking requirements and other system parameters in Recommendation T.70.
+
+TABLE 1/T.71
+
+### Description of state transitions
+
+| Present state | Event                                                                                                 | Action                                                                                                                               | New state |
+|---------------|-------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------|-----------|
+| 0             | Calling DTE: Data circuit established (e.g. data set ready, ready for data)                           | <img alt="arrow pointing right" data-bbox="943 663 1257 680" src="4c762280fc3cf84826d3a0bb06c9d672_img.jpg"/>                        | 4         |
+| 0             | Called DTE: Data circuit established (e.g. data set ready, ready for data)                            | Start timer T                                                                                                                        | 2         |
+| 4             | Indication of availability of the physical level for transmission                                     | Send indication to the remote DTE that the half-duplex sending state has been entered<br>Status <OP-T><br>(see Note 1)               | 1         |
+| 1             | Conclusion of transmission                                                                            | Send request that remote DTE enter the half-duplex sending state<br>(see Note 4)<br>Start timer T<br>Status <INOP-T><br>(see Note 2) | 2         |
+| 2             | Reception of indication that the remote DTE has entered the half-duplex sending state                 | Stop timer T                                                                                                                         | 3         |
+| 2             | Expiry of timer T                                                                                     | <img alt="arrow pointing right" data-bbox="943 1272 1257 1290" src="917a6b5d4a0965b5ce7b1c98f86fb95a_img.jpg"/>                      | 4         |
+| 3             | Reception of notification that the remote DTE is requesting a change in the direction of transmission | <img alt="arrow pointing right" data-bbox="943 1335 1257 1352" src="7ca3e7ecfe7105a58461c65ae98ef9b3_img.jpg"/>                      | 4         |
+| 1             | LAPB has entered a disconnected phase (i.e. Control <TERM>, see Note 3)                               | <img alt="arrow pointing right" data-bbox="943 1464 1257 1482" src="5e364519788f202284db85f4ab2f3fd5_img.jpg"/>                      | 0         |
+| 3             | LAPB has entered a disconnected phase (i.e. Control <TERM>, see Note 3)                               | <img alt="arrow pointing right" data-bbox="943 1554 1257 1572" src="500e48496fed548d511acf1b81418f11_img.jpg"/>                      | 0         |
+| Any           | Physical level has no circuit to a remote DTE                                                         | <img alt="arrow pointing right" data-bbox="943 1635 1257 1653" src="897b2bcc4ab1a492cbee936e7829252b_img.jpg"/>                      | 0         |
+
+*Note 1* – Status <OP-T> indicates to LAPB that the sending of frames is enabled.
+
+*Note 2* – Status <INOP-T> indicates to LAPB that the sending of frames is inhibited.
+
+*Note 3* – Control <TERM> indicates that LAPB has entered the disconnected phase (equivalent to ADM of HDLC).
+
+*Note 4* – HDLM uses the idle data link channel state indication (at least 15 contiguous 1's) for requesting that the remote DTE enter the half-duplex sending state.
+
+TABLE 2/T.71
+
+### Description of state transitions in terms of the V.26 *bis* modem interface
+
+| Present state | Event                                                 | Action                                                                                                                                                                 | New state |
+|---------------|-------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------|
+| 0             | Calling DTE: Circuit 107 ON                           | Turn circuit 105 ON<br>Connect LAPB to circuit 103                                                                                                                     | 4         |
+| 0             | Calling DTE: Circuit 107 ON                           | Start timer T                                                                                                                                                          | 2         |
+| 4             | Circuit 106 ON                                        | Enable sending of LAPB frames<br>(see Note 1)                                                                                                                          | 1         |
+| 1             | Transmission concluded (see Note 2)                   | Inhibit sending of LAPB frames<br>Disconnect LAPB from circuit 103<br>Hold circuit 103 in the binary 1 condition<br>Turn circuit 105 OFF (see Note 3)<br>Start timer T | 2         |
+| 2             | Reception of a flag                                   | Stop timer T                                                                                                                                                           | 3         |
+| 2             | Expiry of timer T                                     | Turn circuit 105 ON<br>Release circuit 103 from binary 1 condition<br>Connect LAPB to circuit 103                                                                      | 4         |
+| 3             | Reception of 15 contiguous 1 bits (see Notes 4 and 5) | Turn circuit 105 ON<br>Release circuit 103 from binary 1 condition<br>Connect LAPB to circuit 103                                                                      | 4         |
+| 1             | LAPB has entered a disconnected phase                 | Turn circuit 105 OFF                                                                                                                                                   | 0         |
+| 3             | LAPB has entered a disconnected phase                 | <img alt="A horizontal arrow pointing to the right." data-bbox="922 1265 1236 1288" src="38518d5d1f1c1f0d28a4ed8932714786_img.jpg"/>                                   | 0         |
+| Any           | Circuit 107 OFF                                       | Turn circuit 105 OFF                                                                                                                                                   | 0         |
+
+*Note 1* – It is necessary to ensure that at least one full flag is transmitted after circuit 106 comes ON. This flag may be the opening flag of the first frame.
+
+*Note 2* – The HDTM may determine that a transmission by the LAPB module has been concluded by either of the following:
+
+- counting a sequence of contiguous flags on circuit 103 while in state 1,
+- a time-out, T,
+- a signal from another source, e.g., from a higher level.
+
+However, if no frame is transmitted while in state 1, not less than five contiguous flags shall be sent in state 1 before entry into state 2.
+
+*Note 3* – It is recommended that circuit 105 not be turned OFF until 15 bit times after the binary 1 condition is established on circuit 103. This will assure transmission of an idle sequence to the remote DTE.
+
+*Note 4* – It is recognized that whether or not an idle sequence is sent by the remote DTE, the DTE will detect an idle sequence after circuit 109 goes OFF, since according to Recommendation V.26 *bis*, this will hold circuit 104 in the binary 1 condition.
+
+*Note 5* – It is understood that circuit 109 will go OFF. Entry into state 4 may be made dependent on this OFF condition, as an implementation option.
+
+# ANNEX A
+
+(to Recommendation T.71)
+
+## **Additional rules making for greater efficiency in half-duplex transmission**
+
+### A.1 *General considerations*
+
+- Greater efficiency is obtained in recovery situations.
+- The application of these rules is optional.
+- The application of these rules does not imply any incompatibility or entail any amendment of DTEs (or DCEs) which observe the procedures described in Recommendation T.71.
+
+### A.2 *Rules of operation*
+
+- 1) Before the DTE (or DCE) gives the turn back, it ensures that it has acknowledged all the frames received and accepted before it received the turn.
+- 2) If the DTE (or DCE) receives or takes the turn, it will always first retransmit all the I-frames which have not been acknowledged.
+- 3) The DTE (or DCE) must replace the last RR frame in each turn, if any, by an REJ frame carrying the appropriate N(R).
\ No newline at end of file
diff --git a/marked/T/T-REC-T.803-202402-I_PDF-E/2d4807f80a3f0106f1722d5722cfac87_img.jpg b/marked/T/T-REC-T.803-202402-I_PDF-E/2d4807f80a3f0106f1722d5722cfac87_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..345ec4e1fe8ba9c96ca94102cd5a95228a196e81
--- /dev/null
+++ b/marked/T/T-REC-T.803-202402-I_PDF-E/2d4807f80a3f0106f1722d5722cfac87_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:75fa26b9de1c1bacc039ee27f5a7b5e549179e1f143fdcfc679aba2f43a4161d
+size 4768
diff --git a/marked/T/T-REC-T.803-202402-I_PDF-E/6f31cdb576d2f15c35c3f266e5f59211_img.jpg b/marked/T/T-REC-T.803-202402-I_PDF-E/6f31cdb576d2f15c35c3f266e5f59211_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..030f08f7582ea3a6641aa83df3bcd8ae3b5dae1a
--- /dev/null
+++ b/marked/T/T-REC-T.803-202402-I_PDF-E/6f31cdb576d2f15c35c3f266e5f59211_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:1d4215f46432b47eae58784eefd7870cf7e19d5090df322359b753ca071e9016
+size 73834
diff --git a/marked/T/T-REC-T.803-202402-I_PDF-E/70a863dc6cd47bac82c12162a9479aac_img.jpg b/marked/T/T-REC-T.803-202402-I_PDF-E/70a863dc6cd47bac82c12162a9479aac_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..1f1f14e4dfde9165d7cb1083bce63ea74a0c84ae
--- /dev/null
+++ b/marked/T/T-REC-T.803-202402-I_PDF-E/70a863dc6cd47bac82c12162a9479aac_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:b44d6c71deba521e0dfbb41cc046d26d7e25cbdb70bf740187c558b2d9161635
+size 70706
diff --git a/marked/T/T-REC-T.803-202402-I_PDF-E/b9c0d46c1148cf65cb79f27fac420981_img.jpg b/marked/T/T-REC-T.803-202402-I_PDF-E/b9c0d46c1148cf65cb79f27fac420981_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..813ec104142df95be12c96f9587f1579eb58ffb0
--- /dev/null
+++ b/marked/T/T-REC-T.803-202402-I_PDF-E/b9c0d46c1148cf65cb79f27fac420981_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:a7ede00c79393cb4c6f0dece4adb784a4bf9a5cf2fb4fd949ee3306001a23a1b
+size 42701
diff --git a/marked/T/T-REC-T.803-202402-I_PDF-E/raw.md b/marked/T/T-REC-T.803-202402-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..5521ce7f8b68f9c8244a9bf84e730a06d675a3a2
--- /dev/null
+++ b/marked/T/T-REC-T.803-202402-I_PDF-E/raw.md
@@ -0,0 +1,1935 @@
+
+
+Recommendation
+
+# **ITU-T T.803 (V3) (02/2024)**
+
+SERIES T: Terminals for telematic services
+
+Still-image compression – JPEG 2000
+
+---
+
+**Information technology – JPEG 2000 image  
+coding system: Conformance testing**
+
+## ITU-T T-SERIES RECOMMENDATIONS
+
+## Terminals for telematic services
+
+|                                                     |                    |
+|-----------------------------------------------------|--------------------|
+| Facsimile – Framework                               | T.0-T.19           |
+| Still-image compression – Test charts               | T.20-T.29          |
+| Facsimile – Group 3 protocols                       | T.30-T.39          |
+| Colour representation                               | T.40-T.49          |
+| Character coding                                    | T.50-T.59          |
+| Facsimile – Group 4 protocols                       | T.60-T.69          |
+| Telematic services – Framework                      | T.70-T.79          |
+| Still-image compression – JPEG-1, Bi-level and JBIG | T.80-T.89          |
+| Telematic services – ISDN Terminals and protocols   | T.90-T.99          |
+| Videotext – Framework                               | T.100-T.109        |
+| Data protocols for multimedia conferencing          | T.120-T.149        |
+| Telewriting                                         | T.150-T.159        |
+| Multimedia and hypermedia framework                 | T.170-T.189        |
+| Cooperative document handling                       | T.190-T.199        |
+| Telematic services – Interworking                   | T.300-T.399        |
+| Open document architecture                          | T.400-T.429        |
+| Document transfer and manipulation                  | T.430-T.449        |
+| Document application profile                        | T.500-T.509        |
+| Communication application profile                   | T.510-T.559        |
+| Telematic services – Equipment characteristics      | T.560-T.619        |
+| General multimedia application frameworks           | T.620-T.649        |
+| User interfaces - Accessibility and human factors   | T.700-T.799        |
+| <b>Still-image compression – JPEG 2000</b>          | <b>T.800-T.829</b> |
+| Still-image compression   JPEG XR                   | T.830-T.849        |
+| Still-image compression – JPEG-1 extensions         | T.850-T.899        |
+
+*For further details, please refer to the list of ITU-T Recommendations.*
+
+# Information technology – JPEG 2000 image coding system: Conformance testing
+
+# Summary
+
+Rec. ITU-T T.800 | ISO/IEC 15444-1 describes an image compression system that allows great flexibility, not only for the compression of images but also for access into the codestream. The codestream provides a number of mechanisms for locating and extracting portions of the compressed image data for the purpose of retransmission, storage, display, or editing. This access allows storage and retrieval of compressed image data appropriate for a given application without decoding.
+
+This Recommendation | International Standard provides the framework, concepts, and methodology for testing and the criteria to be achieved to claim compliance to Rec. ITU-T T.800 | ISO/IEC 15444-1 or Rec. ITU-T T.814 | ISO/IEC 15444-15. The objective of standardization in this field is to promote interoperability between JPEG 2000 encoders and decoders and to test these systems for compliance to this Recommendation | International Standard. Compliance testing is the testing of a candidate product for the existence of specific characteristics required by a standard. It involves testing the capabilities of an implementation against both the compliance requirements in the relevant standard and the statement of the implementation's capability.
+
+The purpose of this Recommendation | International Standard is to define a common test methodology, to provide a framework for specifying abstract test suites (ATSs), and to define the procedures to be followed during compliance testing.
+
+Any organization contemplating the use of test methods defined in this Recommendation | International Standard should carefully consider the constraints on their applicability. Compliance testing does not include robustness testing, acceptance testing, and performance testing.
+
+NOTE – This Recommendation | International Standard is in its third edition from the International Telecommunication Union (ITU) and in its fourth edition from the International Organization for Standardization /International Electrotechnical Commission (ISO/IEC).
+
+This edition cancels and replaces the previous edition which has been technically revised.
+
+The main changes compared to the previous edition are as follows:
+
+- the maximum allowable errors associated with compliance Class 1, for both Rec. ITU-T T.800 | ISO/IEC 15444-1 and Rec. ITU-T T.814 | ISO/IEC 15444-15 codestreams, have been relaxed in a few cases to ensure that well designed 16-bit fixed-point implementations of the inverse discrete wavelet transform should be able to pass all compliance tests for Class 1;
+- two additional test codestreams have been added along with conformance bounds, to facilitate testing of inverse wavelet and component decorrelating transform accuracy;
+- a number of codestreams and files conforming to Rec. ITU-T T.801 | ISO/IEC 15444-2 have been included for informative purposes only, to facilitate the development of decoders and file format readers that are able to support features beyond the core capabilities found in Rec. ITU-T T.800 | ISO/IEC 15444-1 and Rec. ITU-T T.814 | ISO/IEC 15444-15.
+
+This Recommendation | International Standard contains a normative electronic attachment with the codestreams used in the application of the procedures described herein that is available from ITU at <https://www.itu.int/net/itu-t/sigdb/speimage/ImageForm-s.aspx?val=10100803> or from ISO at <https://standards.iso.org/iso-iec/15444/-4/ed-4/en>.
+
+## Source
+
+This document was prepared by Technical Committee ISO/IEC JTC 1, *Information technology*, Subcommittee SC 29, *Coding of audio, picture, multimedia and hypermedia information*, in collaboration with ITU-T Study Group 16. An identical text is published as ISO/IEC 15444-4:2021.
+
+## History \*
+
+| Edition | Recommendation            | Approval   | Study Group | Unique ID          |
+|---------|---------------------------|------------|-------------|--------------------|
+| 1.0     | ITU-T T.803               | 2002-11-29 | 16          | 11.1002/1000/6179  |
+| 1.1     | ITU-T T.803 (2002) Cor. 1 | 2009-03-16 | 16          | 11.1002/1000/9720  |
+| 2.0     | ITU-T T.803 (V2)          | 2021-06-13 | 16          | 11.1002/1000/14667 |
+| 3.0     | ITU-T T.803 (V3)          | 2024-02-13 | 16          | 11.1002/1000/15850 |
+
+\* To access the Recommendation, type the URL <https://handle.itu.int/> in the address field of your web browser, followed by the Recommendation's unique ID.
+
+## FOREWORD
+
+The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis.
+
+The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics.
+
+The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1.
+
+In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC.
+
+## NOTE
+
+In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party.
+
+## INTELLECTUAL PROPERTY RIGHTS
+
+ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process.
+
+As of the date of approval of this Recommendation, ITU had received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at <http://www.itu.int/ITU-T/ipr/>.
+
+© ITU 2024
+
+All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU.
+
+# CONTENTS
+
+|                                                                                | <i>Page</i> |
+|--------------------------------------------------------------------------------|-------------|
+| 1 Scope .....                                                                  | 1           |
+| 2 References .....                                                             | 1           |
+| 3 Definitions .....                                                            | 1           |
+| 4 Abbreviations and symbols .....                                              | 4           |
+| 4.1 Abbreviations .....                                                        | 4           |
+| 4.2 Symbols .....                                                              | 5           |
+| 5 Conventions .....                                                            | 6           |
+| 6 General description .....                                                    | 6           |
+| 6.1 Profiles, derived sets and compliance classes .....                        | 7           |
+| 6.2 Decoders .....                                                             | 8           |
+| 6.3 Encoders and codestreams .....                                             | 8           |
+| 6.4 Implementation compliance statement .....                                  | 8           |
+| 6.5 Abstract test suites .....                                                 | 8           |
+| 6.6 Encoder compliance testing procedure .....                                 | 9           |
+| 6.7 Decoder compliance testing procedure .....                                 | 9           |
+| 6.8 Procedures for testing file format readers .....                           | 9           |
+| 6.9 Additional test codestreams and files .....                                | 9           |
+| 7 Copyright .....                                                              | 9           |
+| 8 Compliance files availability and updates .....                              | 9           |
+| Annex A Decoder compliance classes .....                                       | 10          |
+| A.1 Compliance class parameter definitions .....                               | 10          |
+| A.1.1 Profile: codestream guarantees .....                                     | 10          |
+| A.1.2 $H$ , $W$ , $C$ : Image size guarantees .....                            | 10          |
+| A.1.3 $N_{cb}$ : Code-block parsing guarantee .....                            | 11          |
+| A.1.4 $N_{comp}$ : Component parsing guarantee .....                           | 11          |
+| A.1.5 $L_{body}$ : Coded data buffering guarantee .....                        | 11          |
+| A.1.6 $M$ : Decoded bit-plane guarantee .....                                  | 12          |
+| A.1.7 $P$ : 9-7I precision guarantee .....                                     | 12          |
+| A.1.8 $B$ : 5-3R precision guarantee .....                                     | 12          |
+| A.1.9 $T_L$ : Transform level guarantee .....                                  | 12          |
+| A.1.10 $L$ : Layer guarantee .....                                             | 12          |
+| A.1.11 Progressions .....                                                      | 12          |
+| A.1.12 Tile-parts .....                                                        | 12          |
+| A.1.13 Precincts .....                                                         | 13          |
+| A.1.14 $M_{MAGB}$ : Magnitude bound guarantee .....                            | 13          |
+| A.2 Compliance class definitions .....                                         | 13          |
+| A.3 Lossless encoding and decoding .....                                       | 14          |
+| Annex B Decoder compliance testing procedures .....                            | 15          |
+| B.1 General .....                                                              | 15          |
+| B.2 Decoder test procedure .....                                               | 15          |
+| B.2.1 Files for testing .....                                                  | 16          |
+| B.2.2 Decoder settings .....                                                   | 16          |
+| B.2.3 Output file format conversion .....                                      | 16          |
+| B.2.4 Compare decoded and formatted components with reference components ..... | 18          |
+| B.2.5 Compare error metrics with specification .....                           | 18          |
+| B.2.6 Reference components file format .....                                   | 18          |
+| Annex C Compliance tests .....                                                 | 20          |
+| C.1 Abstract test suite (informative) .....                                    | 20          |
+| C.1.1 Syntax and compressed data order .....                                   | 20          |
+| C.1.2 Arithmetic entropy encoding .....                                        | 20          |
+| C.1.3 Coefficient bit modelling .....                                          | 21          |
+| C.1.4 Quantization .....                                                       | 21          |
+| C.1.5 Discrete wavelet transform .....                                         | 21          |
+| C.1.6 DC level shift and multiple component transform .....                    | 21          |
+
+|              |                                                                                   |    |
+|--------------|-----------------------------------------------------------------------------------|----|
+| C.1.7        | Region of interest .....                                                          | 21 |
+| C.1.8        | JP2 file format .....                                                             | 21 |
+| C.1.9        | High throughput cleanup pass coding .....                                         | 22 |
+| C.1.10       | HT refinement pass coding .....                                                   | 22 |
+| C.1.11       | Placeholder passes .....                                                          | 22 |
+| C.1.12       | Mixing of HT and J2K code-blocks within HTJ2K codestreams .....                   | 22 |
+| C.1.13       | JPH File format .....                                                             | 22 |
+| C.2          | Executable test suite .....                                                       | 22 |
+| C.2.1        | Class 0 Profile-0 .....                                                           | 23 |
+| C.2.2        | Class 0 Profile-1 .....                                                           | 27 |
+| C.2.3        | Class 1 Profile-0 .....                                                           | 28 |
+| C.2.4        | Class 1 Profile-1 .....                                                           | 30 |
+| C.2.5        | Class 1HF Profile 1 .....                                                         | 30 |
+| Annex D      | Encoder compliance test procedure .....                                           | 32 |
+| D.1          | General .....                                                                     | 32 |
+| D.2          | Reference decoder .....                                                           | 32 |
+| D.3          | Compliance requirement and acceptance .....                                       | 32 |
+| D.4          | Encoding compliance test procedure .....                                          | 32 |
+| Annex E      | Decoder implementation compliance statement .....                                 | 34 |
+| E.1          | General .....                                                                     | 34 |
+| E.2          | Decoder implementation compliance statement .....                                 | 34 |
+| E.3          | Extended support .....                                                            | 34 |
+| Annex F      | Encoder implementation compliance statement .....                                 | 37 |
+| F.1          | General .....                                                                     | 37 |
+| F.2          | Encoder description .....                                                         | 37 |
+| Annex G      | JP2 and JPH file format reader compliance testing procedures .....                | 39 |
+| G.1          | General .....                                                                     | 39 |
+| G.2          | JP2 file compliance requirement and acceptance .....                              | 39 |
+| G.3          | Reading a JP2 file compliance test procedure .....                                | 39 |
+| G.4          | JP2 file format test codestreams and images .....                                 | 40 |
+| G.4.1        | Test files .....                                                                  | 40 |
+| G.4.2        | Reference decoded images .....                                                    | 40 |
+| G.4.3        | Tolerances .....                                                                  | 40 |
+| G.4.4        | Additional information regarding the JP2 test files .....                         | 41 |
+| G.5          | JPH file format test codestreams and images .....                                 | 42 |
+| G.5.1        | Test files .....                                                                  | 42 |
+| G.5.2        | Relationship between the JP2 and JPH test files .....                             | 42 |
+| Annex H      | Test codestreams and files conforming to Rec. ITU-T T.801   ISO/IEC 15444-2 ..... | 43 |
+| H.1          | General .....                                                                     | 43 |
+| H.2          | Extended test codestreams .....                                                   | 43 |
+| H.3          | JPX test files .....                                                              | 44 |
+| Bibliography | .....                                                                             | 45 |
+
+Electronic attachment: Codestreams used in the application of the procedures described in this Specification.
+
+## List of Tables
+
+|                                                                                             | <i>Page</i> |
+|---------------------------------------------------------------------------------------------|-------------|
+| Table 1 – HTJ2K derived sets employed in this Recommendation   International Standard ..... | 8           |
+| Table A.1 – Definitions of compliance classes (Cclass) for J2K decoders .....               | 13          |
+| Table A.2 – Definitions of derived compliance classes (Cclass) for HTJ2K decoders .....     | 13          |
+| Table A.3 – Definitions of HiFi compliance classes .....                                    | 14          |
+| Table C.1 – Class 0 Profile-0 reference images and allowable errors .....                   | 23          |
+| Table C.1bis – Additional allowable errors for HTJ2K TCSs belonging to derived set 0 .....  | 24          |
+| Table C.2 – Items tested by Profile-0 codestreams .....                                     | 24          |
+| Table C.2bis – Items tested by derived set 0 HTJ2K codestreams .....                        | 25          |
+
+|                                                                                            |    |
+|--------------------------------------------------------------------------------------------|----|
+| Table C.3 – Profile-0 codestream 0 contents .....                                          | 26 |
+| Table C.4 – Class 0 Profile-1 reference images and allowable errors .....                  | 27 |
+| Table C.4bis – Additional allowable errors for HTJ2K TCSs belonging to derived set 1 ..... | 27 |
+| Table C.5 – Items tested by Profile-1 codestreams.....                                     | 28 |
+| Table C.5bis – Items tested by derived set 1 HTJ2K codestreams .....                       | 28 |
+| Table C.6 – Class 1 Profile-0 reference files and maximum error .....                      | 29 |
+| Table C.7 – Class 1 Profile-1 reference images and allowable error .....                   | 30 |
+| Table C.8 – Class 1HF Profile 1 reference images and allowable error .....                 | 31 |
+| Table E.1 – ICS for defined Cclasses, profiles and derived sets.....                       | 34 |
+| Table E.2 – Extended capabilities for Cclass 0.....                                        | 35 |
+| Table E.3 – Extended capabilities for Cclass 1 .....                                       | 35 |
+| Table E.4 – Extended capabilities for Cclass 2.....                                        | 35 |
+| Table E.5 – Extended capabilities for derived Cclass 0h.....                               | 36 |
+| Table E.6 – Extended capabilities for derived Cclass 1h.....                               | 36 |
+| Table E.7 – Extended capabilities for derived Cclass 2h.....                               | 36 |
+| Table F.1 – Encoder implementation marker usage .....                                      | 37 |
+| Table G.1 – JP2 reference images and allowable error.....                                  | 41 |
+| Table H.1 – Properties of each extended codestream .....                                   | 43 |
+| Table H.2 – Properties of each JPX test file .....                                         | 44 |
+
+# **List of Figures**
+
+|                                                                        |    |
+|------------------------------------------------------------------------|----|
+| Figure B.1 – Decoder compliance test flow chart.....                   | 15 |
+| Figure D.1 – Encoder compliance test block diagram .....               | 33 |
+| Figure G.1 – JP2 file format reader compliance test block diagram..... | 40 |
+
+
+
+# INTERNATIONAL STANDARD ITU-T RECOMMENDATION
+
+# **Information technology – JPEG 2000 image coding system: Conformance testing**
+
+# 1 Scope
+
+This Recommendation | International Standard<sup>1</sup> specifies the framework, concepts, methodology for testing, and criteria to be achieved to claim compliance to Rec. ITU-T T.800 | ISO/IEC 15444-1 or Rec. ITU-T T.814 | ISO/IEC 15444-15. It provides a framework for specifying abstract test suites (ATSs) and for defining the procedures to be followed during compliance testing.
+
+This Recommendation | International Standard:
+
+- specifies compliance testing procedures for encoding and decoding using Rec. ITU-T T.800 | ISO/IEC 15444-1 and Rec. ITU-T T.814 | ISO/IEC 15444-15;
+- specifies codestreams, decoded images, and error metrics to be used with the testing procedures;
+- specifies ATSs;
+- provides guidance for creating an encoder compliance test
+
+This Recommendation | International Standard does not include the following tests:
+
+**Acceptance testing:** the process of determining whether an implementation satisfies acceptance criteria and enables the user to determine whether or not to accept the implementation. This includes the planning and execution of several kinds of tests (e.g., functionality, quality, and speed performance testing) that demonstrate that the implementation satisfies the user requirements.
+
+**Performance testing:** measures the performance characteristics of an implementation under test (IUT) such as its throughput and responsiveness, under various conditions.
+
+**Robustness testing:** the process of determining how well an implementation processes data which contains errors.
+
+# 2 References
+
+The following Recommendations and International Standards contain provisions which, through reference in this text, constitute provisions of this Recommendation | International Standard. At the time of publication, the editions indicated were valid. All Recommendations and Standards are subject to revision, and parties to agreements based on this Recommendation | International Standard are encouraged to investigate the possibility of applying the most recent edition of the Recommendations and Standards listed below. Members of IEC and ISO maintain registers of currently valid International Standards. The Telecommunication Standardization Bureau of the ITU maintains a list of currently valid ITU-T Recommendations.
+
+- Recommendation ITU-T T.800 | ISO/IEC 15444-1, *Information technology – JPEG 2000 image coding system: Core coding system*.
+- Recommendation ITU-T T.814 | ISO/IEC 15444-15, *Information technology – JPEG 2000 image coding system: High-throughput JPEG 2000*.
+
+# 3 Definitions
+
+For the purposes of this Recommendation | International Standard, the terms and definitions given in Rec. ITU-T T.800 | ISO/IEC 15444-1, Rec. ITU-T T.814 | ISO/IEC 15444-15 and the following apply.
+
+**3.1 abstract test suite (ATS):** Generic compliance testing concepts and procedures for a given requirement.
+
+**3.2 arithmetic coder:** Entropy coder that converts variable length strings to variable length codes (encoding) and vice versa (decoding).
+
+<sup>1</sup> This Recommendation | International Standard includes an electronic attachment with the codestreams used in the application of the procedures described the Specification.
+
+- 3.3 big endian:** Order of bytes in which the most significant byte comes first.
+- 3.4 bit:** Contraction of the term "binary digit"; a unit of information represented by a 0 or a 1.
+- 3.5 bit-depth:** Number of bits required to represent an original component of an image:
+- 3.6 bit-plane:** Two-dimensional array of bits, referring to all the bits of the same magnitude in all coefficients or samples, within a component, a tile- component, a code-block, a region of interest, or other.
+- 3.7 bitstream:** Sequence of bits resulting from the coding of a sequence of symbols, not including any markers or marker segments from the main and tile-part headers, not including packet headers, and not including in stream markers or marker segments or the end of codestream marker.
+- 3.8 box:** Portion of the file format defined by a length and unique box type.  
+Note on entry: Boxes of some types may contain other boxes.
+- 3.9 byte:** Eight bits.
+- 3.10 Cclass:** Defines a level of performance for a decoder, also providing guidance for encoders to produce codestreams that are easily decodable by compliant decoders.
+- 3.11 code-block:** A rectangular grouping of coefficients from the same sub-band of a tile-component.
+- 3.12 coder:** Embodiment of either an encoding or decoding process.
+- 3.13 codestream:** Collection of one or more bitstreams and the main header, tile-part headers, and the end of codestream marker required for their decoding and expansion into image data.  
+Note on entry: This is the image data in a compressed form with all of the signalling needed to decode, but not including the file format.
+- 3.14 coding pass:** Procedure accessing coefficients in a code-block where the context and bit are determined.  
+Note on entry: Typically, there are three different coding passes for each bit-plane, each coefficient will be represented in exactly one of the three passes; for an encoder a coding pass examines coefficients and augments a bitstream; for a decoder a coding pass reads a bitstream and updates coefficients.
+- 3.15 coefficient:** Value that result from a transformation.
+- 3.16 component:** Two-dimensional array of samples.  
+Note on entry: An image typically consists of several components (e.g., red, green, and blue).
+- 3.17 compressed image data:** Part or all of a codestream, or a collection of bitstreams in part or all of a codestream.
+- 3.18 compliance:** Fulfilment of the specified requirements, as defined in this Recommendation | International Standard, for a given Profile and Cclass.
+- 3.19 compliance test procedure:** The process of assessing compliance.
+- 3.20 context:** Function of coefficients previously decoded and used to condition the decoding of the present coefficient.
+- 3.21 decoder:** Embodiment of a decoding process, and optionally a colour transformation process.
+- 3.22 decoding process:** Process that takes as its input all or part of a codestream and outputs all or part of a reconstructed image.
+- 3.23 decomposition level:** Collection of wavelet sub-bands where each coefficient has the same spatial impact or span with respect to the source component samples, including all sub-bands of the same two-dimensional sub-band decomposition, where the last decomposition level also includes the LL sub-band.
+- 3.24 discrete wavelet transformation (DWT):** Transformation that iteratively transforms one signal into two or more filtered and decimated signals corresponding to different frequency bands.  
+Note on entry: This transformation operates on spatially discrete samples.
+- 3.25 encoder:** Embodiment of an encoding process, optionally including a colour transformation process.
+- 3.26 encoding process:** Process that takes as its input all or part of a source image data and outputs a codestream.
+- 3.27 executable test suite (ETS):** Set of executable test cases that support the abstract test cases.
+- 3.28 file format:** Codestream and additional support data and information not explicitly required for the decoding of the codestream.
+
+Note on entry: Examples of such support data include text fields providing titling, security and historical information, data to support placement of multiple codestreams within a given data file, and data to support exchange between platforms or conversion to other file formats.
+
+**3.29 fully decode:** Applying Rec. ITU-T T.800 | ISO/IEC 15444-1 to produce an image from a codestream where all coded data in the codestream has been used to produce the image.
+
+**3.30 guard bits:** Additional most significant bitplanes, beyond the nominal dynamic range of a wavelet sub-band, that have been included in coding of the sample data.
+
+**3.31 header:** Either a part of the codestream that contains only markers and marker segments (main header and tile part header) or the signalling part of a packet (packet header).
+
+**3.32 image:** Set of all components.
+
+**3.33 image data:** Component samples making up an image.
+
+Note on entry: Image data can refer to either the source image data or the reconstructed image data.
+
+**3.34 implementation:** Realization of a specification.
+
+**3.35 implementation compliance statement (ICS):** Statement of specification options and the extent to which they have been implemented by an implementation under test.
+
+**3.36 implementation under test (IUT):** Implementation that is being evaluated for compliance.
+
+**3.37 irreversible:** Transformation, progression, system, quantization, or other process that, due to systemic or quantization error, prevents lossless recovery.
+
+**3.38 JPEG (Joint Photographic Experts Group):** The joint ISO/ITU committee responsible for developing standards for continuous-tone still picture coding, also referring to the standards produced by this committee: Rec. ITU-T T.81 | ISO/IEC 10918-1, Rec. ITU-T T.83 | ISO/IEC 10918-2, Rec. ITU-T T.84 | ISO/IEC 10918-3 and Rec. ITU-T T.87 | ISO/IEC 14495-1.
+
+**3.39 LL sub-band:** Sub-band obtained by forward horizontal low-pass filtering and vertical low-pass filtering.
+
+Note on entry: This sub-band contributes to reconstruction with inverse vertical low-pass filtering and horizontal low-pass filtering.
+
+**3.40 layer:** Collection of compressed image data from coding passes of one, or more, code-blocks of a tile-component, where layers have an order for encoding and decoding that has to be preserved.
+
+**3.41 lossless:** Descriptive term for the effect of the overall encoding and decoding processes in which the output of the decoding process is identical to the input to the encoding process, such that distortion-free restoration can be assured and all of the coding processes or steps used for encoding and decoding are reversible.
+
+**3.42 lossy:** Descriptive term for the effect of the overall encoding and decoding processes in which the output of the decoding process is not identical to the input to the encoding process, because at least one of the coding processes or steps used for encoding and decoding is irreversible.
+
+**3.43 main header:** Group of markers and marker segments at the beginning of the codestream that describe the image parameters and coding parameters that can apply to every tile and tile-component.
+
+**3.44 marker:** Two-byte code in which the first byte is hexadecimal FF (0xFF) and the second byte is a value between 1 (0x01) and hexadecimal FE (0xFE).
+
+**3.45 marker segment:** Marker and associated (not empty) set of parameters.
+
+**3.46 packet:** Part of the codestream comprising a packet header and the compressed image data from one layer of one precinct of one resolution level of one tile-component.
+
+**3.47 packet header:** Portion of the packet that contains signalling necessary for decoding that packet.
+
+**3.48 parser:** Reads and identifies components of the codestream down to the code-block level.
+
+**3.49 partial decoding:** Producing an image from a subset of an entire codestream.
+
+**3.50 precinct:** Rectangular region of a transformed tile-component, within each resolution level, used for limiting the size of packets.
+
+**3.51 precision:** Number of bits allocated to a particular sample, coefficient, or other binary numerical representation.
+
+**3.52 progression:** Order of a codestream where the decoding of each successive bit contributes to a "better" reconstruction of the image.
+
+Note on entry: What metrics make the reconstruction "better" is a function of the application; some examples of progression are increasing resolution or improved sample fidelity.
+
+**3.53 profile:** Subset of technology, from Rec. ITU-T T.800 | ISO/IEC 15444-1, that meets the needs of a given application with limits on parameters within a selected technology.
+
+Note on entry: Profiles are codestream limitations.
+
+**3.54 quantization:** Method of reducing the precision of the individual coefficients to reduce the number of bits used to represent them.
+
+Note on entry: Quantization can be achieved by an explicit operation with a given quantization value (scalar quantization) or by dropping (truncating) coding passes from the codestream.
+
+**3.55 reconstructed image:** Image that is the output of a decoder.
+
+**3.56 reference grid:** Regular rectangular array of points used to define other rectangular arrays of data.
+
+Note on entry: The reference grid is used to determine the number of samples in tile-components for example.
+
+**3.57 region of interest (ROI):** Collection of coefficients that are considered of particular relevance by some user-defined measure.
+
+**3.58 reversible:** Transformation, progression, system, or other process that does not suffer systemic or quantization error and therefore allows for lossless signal recovery.
+
+**3.59 reversible filter:** Particular filter pair used in the wavelet transformation which allows lossless compression.
+
+**3.60 sample:** One element in the two-dimensional array that comprises a component.
+
+**3.61 selective arithmetic coding bypass:** Coding style where some of the code-block passes are not coded by the arithmetic coder, where the bits to be coded are instead appended directly to the bitstream without coding.
+
+**3.62 shift:** Multiplication or division of a number by powers of two, where division of an integer via shift implies truncation toward minus infinity of the non-integer portion.
+
+**3.63 sign bit:** Bit that indicates whether a number is positive (value 0) or negative (value 1).
+
+**3.64 sign-magnitude notation:** Binary representation of an integer where the distance from the origin is expressed with a positive number and the direction from the origin (positive or negative) is expressed with a separate single sign bit.
+
+**3.65 source image:** Image used as input to an encoder.
+
+**3.66 sub-band:** Group of transform coefficients resulting from the same sequence of low-pass and high-pass filtering operations, both vertically and horizontally.
+
+**3.67 testing:** Process of evaluating compliance.
+
+**3.68 tile:** Rectangular array of points on the reference grid, registered with an offset from the reference grid origin and defined by a width and height.
+
+**3.69 tile-component:** All the samples of a given component in a tile.
+
+**3.70 tile-part:** Portion of the codestream with compressed image data for some, or all, of a tile, including one or more packets that make up the coded tile.
+
+**3.71 tile-part header:** Group of markers and marker segments at the beginning of each tile-part in the codestream that describe the tile-part coding parameters.
+
+**3.72 transformation:** Mathematical mapping from one signal space to another.
+
+**3.73 transform coefficient:** Value that is the result of a transformation.
+
+# 4 Abbreviations and symbols
+
+## 4.1 Abbreviations
+
+For the purposes of this Recommendation | International Standard, the abbreviations given in Rec. ITU-T T.800 | ISO/IEC 15444-1 and the following apply.
+
+|      |                                                                                             |
+|------|---------------------------------------------------------------------------------------------|
+| ATS  | Abstract Test Suite                                                                         |
+| BSET | subset of the ETS consisting of HTJ2K test codestreams that differ only by $B_{MAGB}$ value |
+| ETS  | Executable Test Suite                                                                       |
+| HT   | High Throughput                                                                             |
+
+|       |                                                                                  |
+|-------|----------------------------------------------------------------------------------|
+| HTJ2K | High Throughput JPEG 2000                                                        |
+| ICC   | International Colour Consortium                                                  |
+| ICS   | Implementation Compliance Statement                                              |
+| ICT   | Irreversible Component Transform                                                 |
+| IDWT  | Inverse Discrete Wavelet Transformation                                          |
+| IEC   | International Electrotechnical Commission                                        |
+| ISO   | International Organization for Standardization                                   |
+| ITU   | International Telecommunication Union                                            |
+| ITU-T | International Telecommunication Union – Telecommunication Standardization Sector |
+| IUT   | Implementation Under Test                                                        |
+| J2K   | JPEG 2000 <sup>2</sup>                                                           |
+| JPEG  | Joint Photographic Experts Group                                                 |
+| MAGB  | Magnitude Bound                                                                  |
+| MSE   | Mean Squared Error                                                               |
+| RCT   | Reversible Component Transform                                                   |
+| ROI   | Region Of Interest                                                               |
+| sRGB  | standard Red–Green–Blue                                                          |
+| TCS   | Test Codestream                                                                  |
+
+## 4.2 Symbols
+
+For the purposes of this Recommendation | International Standard, the following symbols apply.
+
+|                   |                                                   |
+|-------------------|---------------------------------------------------|
+| 0x                | Denotes a hexadecimal number                      |
+| $B$               | Bit-depth precision for reversible 5-3            |
+| $B_{\text{MAGB}}$ | Magnitude bound parameter for an HTJ2K codestream |
+| $C$               | Component guaranteed to be decoded                |
+| CAP               | Capabilities                                      |
+| COC               | Coding style Component                            |
+| COD               | Coding style Default                              |
+| COM               | Comment                                           |
+| CPF               | Corresponding Profile                             |
+| CRG               | Component Registration                            |
+| EPH               | End of Packet Header                              |
+| EOC               | End of Codestream                                 |
+| $H$               | image Height guarantee                            |
+| $L$               | Layer guarantee                                   |
+| $L_{\text{body}}$ | code data buffering guarantee                     |
+| $M$               | decoded bit-plane guarantee                       |
+| $M_{\text{MAGB}}$ | Magnitude bound decoding guarantee                |
+| $N_{\text{cb}}$   | code-block parsing guarantee                      |
+| $N_{\text{comp}}$ | component parsing guarantee                       |
+| $P$               | irreversible 9-7 Precision guarantee              |
+| PLM               | Packet Length, Main header marker                 |
+| PLT               | Packet Length, Tile-part header marker            |
+
+<sup>2</sup> As defined in Rec. ITU-T T.800 | ISO/IEC 15444-1.
+
+|       |                                                |
+|-------|------------------------------------------------|
+| POC   | Progression Order Change marker                |
+| PPM   | Packed Packet headers, Main header marker      |
+| PPT   | Packed Packet headers, Tile-part header marker |
+| PRF   | Profile marker                                 |
+| QCC   | Quantization Component marker                  |
+| QCD   | Quantization Default marker                    |
+| RGN   | Region of interest marker                      |
+| SIZ   | image and tile Size marker                     |
+| SOC   | Start Of Codestream marker                     |
+| SOD   | Start Of Data marker                           |
+| SOP   | Start Of Packet marker                         |
+| SOT   | Start Of Tile-part marker                      |
+| $T_L$ | Transform level guarantee                      |
+| TLM   | Tile-part Lengths marker                       |
+| $W$   | image Width guarantee                          |
+
+# 5 Conventions
+
+The compliance files including test codestreams, JP2 files, JPH files, reference decoded images, and descriptive files are supplied in the form of a compressed file. File locations given in this Recommendation | International Standard are expressed relative to the top level of the directory tree. A Unix style file structure and delimiters are assumed.
+
+This Recommendation | International Standard contains instructions for the use of these files. No support can be provided by ISO | ITU-T beyond that offered in this Recommendation | International Standard.
+
+# 6 General description
+
+Perhaps the most distinctive feature of JPEG 2000 is its emphasis on and support for scalability. An existing codestream may be accessed at a reduced resolution, at a reduced quality (higher compression), at a reduced number of components, and even over a reduced spatial region. Moreover, this Recommendation | International Standard supports a rich family of information progression sequences whereby the information may be reordered without introducing additional distortion. This enables a single compressed codestream to serve the needs of a diverse range of applications.
+
+This Recommendation | International Standard also covers compliance for implementations of Rec. ITU-T T.814 | ISO/IEC 15444-15. To avoid confusion, the terms JPEG 2000 (J2K) and high throughput JPEG 2000 (HTJ2K) are used in this Recommendation | International Standard, where necessary, to differentiate between JPEG 2000 codestreams that conform to Rec. ITU-T T.800 | ISO/IEC 15444-1 and those that conform to Rec. ITU-T T.814 | ISO/IEC 15444-15, respectively. J2K codestreams can be reversibly transcoded to HTJ2K and vice-versa, without any loss in information. This property allows compliance for HTJ2K and J2K implementations to be treated in a very similar manner. In fact, all of the HTJ2K test codestreams and JPH files provided in the electronic attachment have been obtained by reversibly transcoding corresponding J2K test codestreams and JP2 files available at the same location. The decoded output from an HTJ2K decoder is expected to conform to the same guidelines as the decoded output from a J2K decoder, processing the corresponding J2K codestream or JP2 file.
+
+From the perspective of compliance, the main distinction between HTJ2K and J2K is that an HTJ2K codestream does not generally possess the same quality scalability attributes as the corresponding J2K codestream. An HTJ2K decoder cannot choose to stop the decoding of a code-block bit-stream at an arbitrary bit-plane, providing a fine grain trade-off between implementation complexity and reconstructed image quality. Considering this difference between HTJ2K and J2K, this Recommendation | International Standard provides multiple transcodings of J2K test codestreams, allowing implementations to be tested at multiple quality operating points.
+
+JPEG 2000 encoders may employ only a fraction of the features supported by Rec. ITU-T T.800 | ISO/IEC 15444-1. Likewise, some decoders will not support all the features supported by this Recommendation | International Standard. It is impossible to provide test cases for all possible combinations of tools that an encoder or decoder may choose to implement. This Recommendation | International Standard provides abstract test procedures for JPEG 2000 encoders and decoders. A developer may designate the features that have been implemented and determine a set of test cases that applies to those features. For the greatest level of interoperability, there are explicit decoder test procedures. These tests are run
+
+for a particular Profile (defined in Rec. ITU-T T.800 | ISO/IEC 15444-1) and a particular compliance class defined herein. Passing the explicit tests allows a decoder to be labelled "Profile-x Cclass-y Compliant".
+
+Even with the explicit decoder tests, it is expected that some decoders may not decode all of the information that was originally incorporated into the codestream by an encoder. This is the only way to truly exploit the scalability of Rec ITU-T T.800 | ISO/IEC 15444-1. It is desirable to allow decoders to ignore information that is not of interest to their target application. While this flexibility is one of the strengths of JPEG 2000, it also renders inappropriate some of the conventional compliance testing methodologies that have been applied to non-scalable or less scalable compression standards.
+
+Many approaches to compliance could be taken. At one extreme, decoder implementations might be allowed to decode any portion of the codestream that is of interest to them. At the other extreme, they might be required to correctly decode the entire codestream. The first approach offers content providers and consumers no guarantee concerning the quality of the resulting imagery. The other approach is also inappropriate because it offers the implementer no guarantee concerning the resources that may be required for decoding, and in many cases the codestream may contain information that is of no interest to the application.
+
+This Recommendation | International Standard describes compliance for JPEG 2000 decoders in terms of a system of guarantees. These guarantees serve to discourage encoders from producing codestreams that will be exceedingly difficult or impossible for a decoder to process, to encourage decoders to provide quality images from any reasonable codestream, and to encourage use of the flexibility and scalability of JPEG 2000 codestreams.
+
+*Profiles* define a subset of technology, from Rec. ITU-T T.800 | ISO/IEC 15444-1, that meets the needs of a given application with limits on parameters within a selected technology. Profiles limit bitstreams. Decoders define capabilities for all bitstreams within a profile. Encoders achieve quality guarantees for particular decoders by encoding bitstreams which meet a particular profile definition. *Compliance classes* (Cclass) define guarantees of a given level of image quality for a decoder and guidance for encoders to produce codestreams that are easily decodable by compliant decoders.
+
+Essentially, if a JPEG 2000 encoder produces a codestream with certain properties, then a decoder of a certain Cclass will be capable of producing an image with some defined level of quality. The compliance class of a decoder is based solely on passing certain tests. The tests in this Recommendation | International Standard are designed to require a compliant decoder to be capable of decoding all codestreams with a set of defined properties.
+
+## 6.1 Profiles, derived sets and compliance classes
+
+Two profiles are defined in Rec. ITU-T T.800 | ISO/IEC 15444-1, labelled Profile-0 and Profile-1. These two profiles describe bitstream constraints for a Rec. ITU-T T.800 | ISO/IEC 15444-1 encoder. Profile-0 is a subset of Profile-1. Hence, any implementation capable of decoding Profile-1 test streams shall be capable of passing the compliance tests for Profile-0 of the same Cclass.
+
+For HTJ2K codestreams, no profiles are defined in Rec. ITU-T T.814 | ISO/IEC 15444-15. All of the HTJ2K test codestreams and JPH files provided in the electronic attachment include a CPF marker segment, that indicates the profile of the J2K codestream from which they were transcoded.
+
+Rec. ITU-T T.814 | ISO/IEC 15444-15 defines constrained codestream sets that partition the space of all HTJ2K codestreams as a function of the capabilities, complexity or throughput of an HTJ2K decoder. One important example is the HTONLY set, which consists of HTJ2K codestreams that use only HT code-blocks. Codestreams that do not belong to the HTONLY set may use the J2K block coding algorithm for some or all of their code-blocks. In particular, the MIXED set of HTJ2K codestreams involve tile-components that use a mixture of HT and J2K code-blocks.
+
+This International Recommendation | Standard provides test procedures and codestreams for HTJ2K decoders that are derived from the same compliance points as those for J2K decoders, by means of a transcoding step. The derived HTJ2K test codestreams are classified into the four derived sets defined in Table-1. Each of the two DS0 sets is a subset of the corresponding DS1 set, being derived from J2K profiles 0 and 1, respectively. Also, the HT derived sets are each subsets of the corresponding HM set.
+
+NOTE – There are many other ways to construct and classify test codestreams for HTJ2K decoders that can be useful for specific applications. The principles embodied by this Recommendation | International Standard can be readily extended to the testing of HTJ2K decoders whose capabilities are classified in a different manner to that set out in Table 1.
+
+Annex A defines three compliance classes (Cclass) for J2K codestreams, and three derived compliance classes for HTJ2K codestreams. These Cclasses define levels of image quality guarantees for decoders and guidance for encoders to produce codestreams that are easily decodable by compliant decoders. Cclass guarantees increase with the increasing Cclass numbers.
+
+Table 1 – HTJ2K derived sets employed in this Recommendation | International Standard
+
+| Derived set | Definition                                                                                                                                          |
+|-------------|-----------------------------------------------------------------------------------------------------------------------------------------------------|
+| DS0_HT      | HTJ2K codestreams with a CPF marker segment that identifies Profile-0 as the compatible profile, that belong to the HTONLY set of HTJ2K codestreams |
+| DS1_HT      | HTJ2K codestreams with a CPF marker segment that identifies Profile-1 as the compatible profile, that belong to the HTONLY set of HTJ2K codestreams |
+| DS0_HM      | HTJ2K codestreams with a CPF marker segment that identifies Profile-0 as the compatible profile, that are not HTONLY                                |
+| DS1_HM      | HTJ2K codestreams with a CPF marker segment that identifies Profile-1 as the compatible profile, that are not HTONLY                                |
+
+## 6.2 Decoders
+
+Compliant implementations of the decoder are not required to decode each codestream in its entirety, but are required to guarantee performance up to one Cclass for some profile. These guarantees are directly connected with the resources required by a decoder. They may be interpreted as a contract by the implementation to recover, decode and transform a well-defined minimal subset of the information contained in any codestream. This contract is described in a manner that scales with the Cclass. The contract may be exploited by content providers to optimize recovered image quality over a family of decoders according to their known Cclasses.
+
+For a given profile, decoder guarantees are expressed in terms of several parameters including decoded image dimensions,  $H$  (height) and  $W$  (width), and a number of components,  $C$ , for the Cclass. The parameters are not dependent on the codestream that is actually being decoded. Annex A defines the parameters and the classes for which compliance claims may be made and tested. Annex E allows a decoder to define guarantees that are greater than that of the defined Cclasses.
+
+A significant characteristic of an HTJ2K decoder is the largest value  $M_{MAGB}$  of the magnitude bound (MAGB) parameter  $B_{MAGB}$  that it supports, as defined in Rec. ITU-T T.814 | ISO/IEC 15444-15. Every HTJ2K codestream advertises a value for this parameter that lies in the range 8 to 74, encoded within its capabilities (CAP) marker segment. For HTJ2K decoders, the  $M_{MAGB}$  value is one of the guarantees that forms part of the implementation's contract. The decoder is not required to exhibit any particular defined behaviour when presented with a codestream for which  $B_{MAGB}$  exceeds the decoder's  $M_{MAGB}$  value. However, for HTJ2K codestreams whose  $B_{MAGB}$  value is less than or equal to  $M_{MAGB}$ , the decoder is expected to exhibit decoded image quality that conforms to the other aspects of the Cclass to which conformance is advertised.
+
+## 6.3 Encoders and codestreams
+
+Rec. ITU-T T.800 | ISO/IEC 15444-1 describes two restricted profiles (Profile-0 and Profile-1) that provide guarantees concerning the parameter ranges and information placement in a codestream. Since codestream limitations may also adversely affect scalability and interoperability, the smallest possible number of limitations are imposed by these profiles. Annex F allows an encoder to define guarantees of codestreams produced by the encoder.
+
+Encoders may also be required to conform to certain guarantees in particular application areas of interest that are outside the scope of this Recommendation | International Standard. As an example, a medical image application may require the encoder to guarantee lossless performance up to a given image size.
+
+## 6.4 Implementation compliance statement
+
+Evaluation of compliance for a particular implementation may require a statement of the options that have been implemented. This will allow the implementation to be tested for compliance against only the relevant requirements.
+
+Such a statement is called an implementation compliance statement (ICS). For J2K implementations, this statement shall contain only options within the framework of requirements specified in Rec. ITU-T T.800 | ISO/IEC 15444-1. For HTJ2K implementations, the ICS for decoders shall also include the  $M_{MAGB}$  limit on supported  $B_{MAGB}$  values. An HTJ2K decoder may provide separate  $M_{MAGB}$  guarantees for codestreams that use irreversible spatial transformations and those that use only reversible spatial transformations, as identified by the HTIRV flag (bit-5) of Ccap<sup>15</sup> in the CAP marker segment, as specified in Rec. ITU-T T.814 | ISO/IEC 15444-15.
+
+Examples of ICSs can be found in Annex E for decoders and Annex F for encoders.
+
+## 6.5 Abstract test suites
+
+The ATSs define general tests for sub-systems of Rec. ITU-T T.800 | ISO/IEC 15444-1. Each ATS includes the following parts and are defined in Annex C.
+
+- a) Test purpose: What the test requirement is.
+- b) Test Method: The procedures to be followed for the given ATS.
+- c) Reference: The portion of the ISO document that is being tested by the given ATS.
+
+## 6.6 Encoder compliance testing procedure
+
+The informative procedures for testing encoders are defined in Annex D and are complemented by the information that is gathered from a completed ICS (Annex F). These procedures are informative since Rec. ITU-T T.800 | ISO/IEC 15444-1 and Rec. ITU-T T.814 | ISO/IEC 15444-15 are both codestream and decoder compliance standards.
+
+## 6.7 Decoder compliance testing procedure
+
+The procedures for testing decoders are defined in Annex B and use the executable test suites (ETSS) that are defined in Annex C. These procedures and ETSS will allow an IUT to evaluate compliance to each profile and Cclass.
+
+## 6.8 Procedures for testing file format readers
+
+The procedures for testing readers of the JP2 and JPH file format are defined in Annex G.
+
+## 6.9 Additional test codestreams and files
+
+The informative Annex H describes additional test codestreams and files that exercise features from Rec. ITU-T T.801 | ISO/IEC 15444-2 [1].
+
+# 7 Copyright
+
+These compliance files were originally developed by the parties indicated in the file **COPYRIGHT**. In particular, the original developers of these files and their respective companies, the editors and their companies, and International Organization for Standardization/International Electrotechnical Commission (ISO/IEC) have disclaimed liability for any proposed use of these files or modifications thereof.
+
+# 8 Compliance files availability and updates
+
+The compliance test images released with this Recommendation | International Standard are the latest tested versions available at the date at which the text was approved.
+
+# Annex A
+
+## Decoder compliance classes
+
+(This annex does not form an integral part of this Recommendation | International Standard.)
+
+This annex describes the compliance classes for J2K and HTJ2K codestreams. The classes and parameters are described to provide assistance in designing a compliant decoder. Actual compliance is determined by the testing procedures in Annex B and the codestreams, reference images, and tolerances in Annex C. The definitions of compliance classes in this annex are useful for the design of an encoder. The parameters may correspond to particular parts of an implementation.
+
+## A.1 Compliance class parameter definitions
+
+Because of resource limitations, implementations of JPEG 2000 sometimes will not be able to decode a codestream in its entirety. This subclause defines various parameters for which a specific implementation might be limited. A set of values for every parameter defines a compliance class. Thus an implementation of a particular Cclass shall guarantee resources as defined in all the parameters.
+
+### A.1.1 Profile: codestream guarantees
+
+Profiles provide limits on the codestream syntax parameters. Two profiles are defined in Rec. ITU-T T.800 | ISO/IEC 15444-1, labelled Profile-0 and Profile-1. Other profiles exist, including one that allows unrestricted use of capabilities in Rec. ITU-T T.800 | ISO/IEC 15444-1. Testing arbitrary codestreams requires almost unlimited computational resources. Thus, all defined tests for J2K decoders pertain to a specific profile and will only use codestreams compliant with that profile. The defined tests for HTJ2K decoders are based on the derived sets defined in Table 1 that are obtained only from J2K codestreams conforming to Profile-0 and Profile-1.
+
+### A.1.2 $H, W, C$ : Image size guarantees
+
+Decoders may be limited in the size of the output image that they are capable of producing, due to physical display characteristics or memory limitations.  $H$ ,  $W$ , and  $C$  are respectively the largest height, width, and number of components that are required to be decoded for a decoder in the compliance class. Codestreams containing more samples than the  $H$ ,  $W$ , and  $C$  for a Cclass shall still be decoded. Compliance for these codestreams is based on the ability to decode at the largest resolution smaller than or equal to that specified by the decoder's Cclass. This largest resolution size is determined by the component in the codestream with the smallest sampling factor relative to the reference grid. For images with different subsampling on different components, the smallest subsampling values are used to determine the region that is decoded, and the corresponding region of each component shall be decoded.
+
+For Cclass 0, a decoder shall be able to decode the largest resolution level that is no larger than 128 samples in either image dimension and that requires no more than three levels of inverse discrete wavelet transformation (IDWT) processing. For Cclass 1, a decoder shall be able to decode the largest resolution level that is no larger than 2048 samples in either image dimension and that requires no more than seven levels of IDWT processing.
+
+Formulae A-1 and A-2 express these restrictions for a single tile image. The minimization with respect to  $XR_{\text{SIZ}}$  over all components selects the component with the smallest sampling relative to the reference grid. The maximum  $r \leq T_L$  that satisfies both conditions is the number of levels that shall be decoded.  $T_L$  is defined in A.1.9.  $X_{\text{SIZ}}$ ,  $Y_{\text{SIZ}}$ ,  $XO_{\text{SIZ}}$ , and  $YO_{\text{SIZ}}$  come from the image and tile size (SIZ) marker segment defined in Rec. ITU-T T.800 | ISO/IEC 15444-1.  $N_L$  is the number of wavelet transform levels used in the image as specified in the coding style default (COD) or coding style component (COC) marker segments. (If a non-negative  $r$  does not exist to satisfy both conditions, then no decoder obligation exists.)
+
+$$\left\lceil \frac{X_{\text{SIZ}}}{\min_{\forall i} (XR_{\text{SIZ}}(i)) \cdot 2^{N_L-r}} \right\rceil - \left\lceil \frac{XO_{\text{SIZ}}}{\min_{\forall i} (XR_{\text{SIZ}}(i)) \cdot 2^{N_L-r}} \right\rceil \leq W \quad (\text{A-1})$$
+
+$$\left\lceil \frac{Y_{\text{SIZ}}}{\min_{\forall i} (YR_{\text{SIZ}}(i)) \cdot 2^{N_L-r}} \right\rceil - \left\lceil \frac{YO_{\text{SIZ}}}{\min_{\forall i} (YR_{\text{SIZ}}(i)) \cdot 2^{N_L-r}} \right\rceil \leq H \quad (\text{A-2})$$
+
+For images with multiple tiles, a tile with top left and bottom right coordinates  $(tx_0, ty_0)$ ,  $(tx_1, ty_1)$  on the reference grid, and number of decompositions levels  $N_L$ , is decodable at resolution  $r \leq T_L$  subject to the restrictions in Formulae A-3 and A-4.
+
+$$\left[ \frac{tx_1}{\min_{\forall i} (XR_{SIZ}(i)) \cdot 2^{N_L-r}} \right] - \left[ \frac{tx_0}{\min_{\forall i} (XR_{SIZ}(i)) \cdot 2^{N_L-r}} \right] \leq W \quad (\text{A-3})$$
+
+$$\left[ \frac{ty_1}{\min_{\forall i} (YR_{SIZ}(i)) \cdot 2^{N_L-r}} \right] - \left[ \frac{ty_0}{\min_{\forall i} (YR_{SIZ}(i)) \cdot 2^{N_L-r}} \right] \leq H \quad (\text{A-4})$$
+
+See Rec. ITU-T T.800 | ISO/IEC 15444-1 for an exact definition of  $tx_0$ ,  $ty_0$ ,  $tx_1$ , and  $ty_1$  including limitations to SIZ marker parameters. If a non-negative  $r$  does not exist to satisfy both conditions for any tile, then no decoder obligation exists. Otherwise, one or more tiles shall be decoded, where the total decoded width need not exceed  $W$  and the total decoded height need not exceed  $H$ . There is no obligation to decode partial tile areas.
+
+NOTE – For the purposes of compliance testing, all possible combinations of these parameters will NOT be provided as test reference images. It can be necessary for the IUT to provide the ability to set the decode resolution and decoded tile position. However, some post processing will be permitted as described in Annex B.
+
+A decoder claiming compliance at some Cclass with image dimensions  $H \times W$  and number of components  $C$  shall also be capable of decoding any image with width less than or equal to  $W$ , height less than or equal to  $H$ , and number of components less than or equal to  $C$ . For each Cclass, the minimum values for  $H$ ,  $W$ , and  $C$  are specified in Table A.1.
+
+### A.1.3 $N_{cb}$ : Code-block parsing guarantee
+
+Decoders need not decode compressed bits that cannot be recovered from the codestream due to excessive parser memory being required. An upper bound for the parser state memory required to reach a point  $x$  in the codestream may be determined from the total number of code-blocks for which state information has to be kept, the total number of precincts for which a packet has been encountered, and the total number of components of the codestream.
+
+At position  $x$  in the codestream,  $N_{cb}(x)$  is defined as the total number of code-blocks in every precinct where the first header byte of at least one received packet for the precinct lies outside the range 0x00 to 0x7F.
+
+Decoders are permitted to stop parsing the codestream at the point,  $x$ , once  $N_{cb}(x) > N_{cb}$ , where  $N_{cb}$  is defined for each compliance class. Decoders are permitted to stop parsing the codestream once packet headers with more than  $N_{cb}$  code-blocks have been encountered. Code-blocks in packets prior to the packet with the  $N_{cb}^{\text{th}}$  code-block shall be decoded up to the limits of other parameters in the compliance class.
+
+NOTE – Packets headers with the first bit set to 0 are defined as empty. The above definition adds all the code-blocks associated with such precincts to  $N_{cb}$  for these empty packets because a decoder requires more memory for these packets than for packets starting in the listed range.
+
+### A.1.4 $N_{comp}$ : Component parsing guarantee
+
+Decoders could be required to buffer information about each component for many thousands of components just to parse a codestream. To limit the required memory, decoders are permitted to stop parsing the codestream at a point,  $x$ , once the following condition is reached:
+
+$$C_{\max}(x) > N_{comp}$$
+
+where  $C_{\max}(x)$  is defined as the largest component index for which a packet has been encountered up to point  $x$  regardless of the emptiness or the relevance of the packet.
+
+Code-blocks in packets prior to the above stop condition shall be decoded up to the limits of other parameters in the compliance class.
+
+### A.1.5 $L_{body}$ : Coded data buffering guarantee
+
+The parser state memory described in A.1.3 is required to parse packets regardless of whether their code-blocks are relevant to the dimensions and number of components for which compliance is being claimed. For those code-blocks that are relevant, the implementation is required to store the recovered packet bytes. These are the code bytes that are processed by the block decoder, as specified in Rec. ITU-T T.800 | ISO/IEC 15444-1.
+
+After a given number of decoded codestream bytes,  $x$ , the quantity  $L_{body}(x)$  is defined as the total number of packet bytes that have been encountered so far in packets whose precincts are relevant to the dimensions and components for which compliance is being claimed. Although some implementations may be able to decode some of these packet bytes incrementally,  $L_{body}$  represents an upper bound on the number of packet bytes that have to be stored by the decoder prior to decoding. If the number of relevant packet bytes exceeds  $L_{body}$ , then the IUT is allowed to stop reading the codestream and to decode the code-blocks obtained up to the limits of other parameters in the compliance class.
+
+#### **A.1.6 *M*: Decoded bit-plane guarantee**
+
+The decoder shall decode all of the packet bytes recovered by the parser in accordance with the requirements described above. This obligation is limited to the most significant  $M$  bit-planes of each code-block. Specifically, the block decoder shall correctly decode the first  $3(M - P_b) - 2$  coding passes, if available, of any relevant code-block,  $b$ , where  $P_b$  is the number of 0-valued most significant bit-planes signalled in the relevant packet header as described in Rec. ITU-T T.800 | ISO/IEC 15444-1. The decoder is free to decode any number of additional coding passes for any code-block. Codestreams with large values for the number of guard bits will have a larger number of 0-valued most significant bit-planes, and thus a decoder of any given Cclass will decode fewer useful bit-planes. Likewise, codestreams with large values for the shift in the region of interest (RGN) marker segment may have fewer bit-planes decoded.
+
+#### **A.1.7 *P*: 9-7I precision guarantee**
+
+Codestreams that make use of the irreversible 9-7 discrete wavelet transform will require dequantization, the 9-7 inverse discrete wavelet transform, and potentially the inverse irreversible component transform (ICT). The precision values for the wavelet transform are chosen to allow high quality imagery at various bit-depths, e.g., 8, 12, or 16 bits per sample. However, for Cclass 0, the accuracy of the 9-7I filter required is set such that it is possible to be compliant by decoding and inverse quantizing and performing a 5-3I (irreversible 5-3) inverse wavelet transform. This allows lower cost decoders to be used for the lowest compliance class only. For higher compliance classes, using the 5-3 filter in place of the 9-7 filter will not be sufficient to pass the compliance tests.
+
+Using the 5-3 inverse wavelet transform to decode imagery compressed with the 9-7 wavelet introduces signal dependent noise. For example, errors are highest around edges in the imagery. Because induced errors are signal dependent, there is no "precision" specified for the implementation of the wavelet transform for Cclass 0. Instead, the bounds on accuracy of the 9-7 transform have been set for each Cclass 0 reference image to allow an implementation to use the 5-3I inverse wavelet filter. Using the 5-3I inverse wavelet transform instead of a 9-7I filter does not relieve a decoder of the requirement to perform inverse quantization.
+
+For compliance classes other than Cclass 0, the precision guarantee in Table A.1 refers to the implementation's minimum word size that will achieve the target mean squared error (MSE) values for the test streams.
+
+To facilitate end-to-end testing for compliance, dequantization may be performed using mid-point rounding. That is, the value of the reconstruction parameter  $r$  in Rec. ITU-T T.800 | ISO/IEC 15444-1 can be  $r = 1/2$ . Implementations under test may provide the option of using different values for the reconstruction parameter,  $r$ ; however, if the value  $r = 1/2$  is supported and employed for compliance testing this will typically increase the ease of passing.
+
+#### **A.1.8 *B*: 5-3R precision guarantee**
+
+A decoder is expected to implement the reversible 5-3R IDWT exactly, for component bit-depths of  $B$  bits/sample or less, as specified in the SIZ marker segment (see Rec. ITU-T T.800 | ISO/IEC 15444-1). If a codestream employs the reversible component transform (RCT) and the IUT claims compliance at three or more components, it shall be able to perform both the 5-3R IDWT and the inverse RCT exactly for bit-depths of  $B$  bits/sample or less.
+
+### **A.1.9 *T<sub>L</sub>*: Transform level guarantee**
+
+For each Cclass, a decoder is expected to be able to synthesize a minimum number of levels of the IDWT,  $T_L$ . For codestreams that contain more than  $T_L$  decomposition levels, the decoded image from a compliant decoder in a given Cclass may include only the top resolution levels.
+
+### **A.1.10 *L*: Layer guarantee**
+
+For each Cclass, a decoder is expected to decode a minimum number of layers,  $L$ , in a codestream. For codestreams that contain more than  $L$  layers, the decoded image from a compliant decoder in a given Cclass may include only the top  $L$  layers. This relieves compliant decoders from the burden of decoding inefficient codestreams with an excessive number of layers.
+
+#### **A.1.11 Progressions**
+
+For all Cclasses, a decoder is expected to decode all possible progressions as specified in the COD marker segment. If a progression order change (POC) marker segment is used in a codestream, a Cclass 0 decoder shall decode packets associated with the first progression order specified in the POC marker segment for that tile. Additional packets in the tile may be skipped. For all other Cclasses, packets may be skipped only due to other limitations (e.g.,  $N_{cb}$  and  $L_{body}$ ) and there is no explicit limitation on the number of POCs that may occur.
+
+### **A.1.12 Tile-parts**
+
+Codestreams may contain multiple tile-parts for each tile. Profile-0 codestreams require all initial tile-parts to appear in spatial order in the codestream before other tile parts. Cclass 0 decoders may ignore tile-parts beyond the first even if  $N_{cb}$
+
+or  $L_{\text{body}}$  has not been reached. For all other Cclasses, tile-parts may be skipped only due to other limitations (e.g.,  $N_{\text{cb}}$  and  $L_{\text{body}}$ ) and there is no explicit limitation on the number of tile-parts that may occur.
+
+### A.1.13 Precincts
+
+Tiles may contain several precincts. Cclass 0 decoders need only decode the first precinct in each sub-band of each tile. Note that Profile-0 codestreams are designed to have only one precinct in each sub-band up to the resolution level decoded by a Cclass 0 decoder. Other profiles do not have this guarantee. Other Cclass decoders shall decode all relevant precincts.
+
+#### A.1.14 $M_{\text{MAGB}}$ : Magnitude bound guarantee
+
+For HTJ2K decoders, compliance classes are further qualified by a maximum supported value for the  $B_{\text{MAGB}}$  parameter of the codestream.
+
+## A.2 Compliance class definitions
+
+Table A.1 defines three compliance classes for J2K decoders, in terms of the parameters in A.1.2 to A.1.13. Table A.2 defines three derived compliance classes for HTJ2K decoders, in terms of the parameters in A.1.2 to A.1.14.
+
+Table A.1 – Definitions of compliance classes (Cclass) for J2K decoders
+
+| Parameter           | Cclass 0                                                                     | Cclass 1                                                                | Cclass 2                                                                |
+|---------------------|------------------------------------------------------------------------------|-------------------------------------------------------------------------|-------------------------------------------------------------------------|
+| $W \times H$ (size) | $128 \times 128$                                                             | $2048 \times 2048$                                                      | $16384 \times 16384$                                                    |
+| $C$ (component)     | 1                                                                            | 4                                                                       | 256                                                                     |
+| $N_{\text{cb}}$     | $(HW/1024 + 32)C = 48$                                                       | $(HW/256 + 128)C = 66\,048$                                             | $(HW/256 + 128)C = 268\,468\,224$                                       |
+| $N_{\text{comp}}$   | 64                                                                           | 256                                                                     | 16\,384                                                                 |
+| $L_{\text{body}}$   | 8192 bytes                                                                   | $2^{23}$ bytes                                                          | $2^{30}$ bytes                                                          |
+| $M$                 | 11                                                                           | 15                                                                      | 30                                                                      |
+| $P$                 | Low enough to allow 5-31 decoding of 9-71 data                               | 16-bit fixed point implementation                                       | 32-bit single precision floats                                          |
+| $B$                 | 8                                                                            | 12                                                                      | 16                                                                      |
+| $T_L$               | 3                                                                            | 7                                                                       | 12                                                                      |
+| $L$                 | 15                                                                           | 255                                                                     | 65535                                                                   |
+| Progressions        | All "basic" progressions in COD, only need decode first progression per tile | Limited only by number of levels, layers and components                 | Limited only by number of levels, layers and components                 |
+| Tile Parts          | Decode only first tile-part per tile                                         | Decode all tile-parts up to $N_{\text{cb}}$ or $L_{\text{body}}$ limits | Decode all tile-parts up to $N_{\text{cb}}$ or $L_{\text{body}}$ limits |
+| Precincts           | Decode 1st precinct per sub-band                                             | Decode all precincts up to $N_{\text{cb}}$ or $L_{\text{body}}$ limits  | Decode all precincts up to $N_{\text{cb}}$ or $L_{\text{body}}$ limits  |
+
+Table A.2 – Definitions of derived compliance classes (Cclass) for HTJ2K decoders
+
+| Parameter                                       | Cclass 0h                              | Cclass 1h                              | Cclass 2h                              |
+|-------------------------------------------------|----------------------------------------|----------------------------------------|----------------------------------------|
+| $W \times H, C, N_{\text{cb}}, \dots$ precincts | As specified for Cclass 0 in Table A.1 | As specified for Cclass 1 in Table A.1 | As specified for Cclass 2 in Table A.1 |
+| $M_{\text{MAGB}}$                               | $\geq 11$                              | $\geq 15$                              | $\geq 30$                              |
+
+To facilitate the testing of inverse wavelet transform and inverse decorrelating transform accuracy in isolation, one additional derivative compliance class is introduced as Cclass 1HF, which is identical to Cclass 1 except that the decoded bit-plane guarantee  $M$  is increased from 15 to 20. For HTJ2K decoders, a Cclass 1HFh is introduced, which is identical to Cclass 1h, except that  $M$  and  $M_{\text{MAGB}}$  are both increased from 15 to 20. This allows test codestreams to be created with high fidelity ("HiFi"), meaning that the quantized sub-band samples can have high precision, while the decoder conforming to Cclass 1HF or Cclass 1HFh, as appropriate, also guarantees to decode the sub-band samples to high precision, so that a significant part of the reconstructed image error can be expected to arise from numerical noise in the implementation of the inverse wavelet and component decorrelating transforms, if they are implemented in 16-bit fixed-point arithmetic. These additional "HiFi" Cclasses are defined in Table A.3.
+
+Table A.3 – Definitions of HiFi compliance classes
+
+| Parameter                                                | Cclass 1HF                                | Cclass 1HFh                                |
+|----------------------------------------------------------|-------------------------------------------|--------------------------------------------|
+| $W \times H, C, N_{cb}, \dots$<br>Precincts, excluding M | As specified for<br>Cclass 1 in Table A.1 | As specified for<br>Cclass 1h in Table A.2 |
+| $M$                                                      | $\geq 20$                                 | $\geq 20$                                  |
+| $M_{MAGB}$                                               | N/A                                       | $\geq 20$                                  |
+
+## A.3 Lossless encoding and decoding
+
+The minimum compliance point, Cclass 0, guarantees sufficient resources to ensure truly lossless decoding to a bit-depth of at least 8 bits per sample. However, this does not mean that lossless performance will be achieved, even if the codestream contains a lossless representation of the image. A compliant Cclass 0 decoder may fail to reproduce a perfectly reconstructed 8-bit version of a losslessly compressed image if the codestream contains a large amount of irrelevant information (e.g., extra image components or resolutions that are not targeted by the particular decoder implementation under consideration). Extra irrelevant information may cause a compliant decoder to stop reading the codestream due to  $L_{\text{body}}$  or  $N_{\text{cb}}$  limits being reached before all relevant information has been recovered.
+
+Again, lossless decompression may not be achieved, even if the codestream contains a lossless representation of 8-bit imagery, if the compressor employed an unnecessarily large number of guard bits or unnecessarily large sub-band dynamic range parameters  $\varepsilon_b$ , for some sub-bands, or if region of interest (ROI) information was included in the codestream. The compressor is at liberty to make such choices and their potential impact on decoders at any Cclass should be considered.
+
+In the HTJ2K case, compliance point Cclass 0h guarantees sufficient resources for truly lossless decoding to a bit-depth of 8 bits per sample. Again, however, this does not mean that lossless performance will be achieved, even if the codestream contains a lossless representation of the image and has MAGB parameter  $B_{\text{MAGB}} \leq 11$ , for the same reasons outlined above. Encoders can losslessly compress 8-bit imagery without requiring a larger MAGB parameter than 11, but if the RCT is employed, the MAGB parameter generally needs to be increased to 12 to ensure a lossless representation.
+
+# Annex B
+
+## Decoder compliance testing procedures
+
+(This annex forms an integral part of this Recommendation | International Standard)
+
+## B.1 General
+
+This annex defines the procedure to follow to determine if a decoder is compliant with a particular compliance class (Cclass) for a particular profile. The Cclass is a level of quality achieved by a decoder. A decoder of a higher Cclass is required to achieve a higher quality image for the same codestream. A decoder compliant with a certain Cclass may have capabilities beyond those required for compliance to that Cclass, but not sufficient for compliance with the next highest Cclass. In such a case, it may be necessary to alter the outputs of the decoder in order to test its compliance with the lower Cclass. This annex defines procedures for such alterations.
+
+## B.2 Decoder test procedure
+
+The procedure defined herein will determine if a decoder is compliant at a chosen profile and Cclass.
+
+![Flowchart for Decoder compliance test procedure. Steps S1 to S5, decisions D1 and D2, and results R1 and R2.](6f31cdb576d2f15c35c3f266e5f59211_img.jpg)
+
+```
+graph TD; S1([S1]) --> S2([S2]); S2 --> S3([S3]); S3 --> S4([S4]); S4 --> D1{D1}; D1 -- No --> R1[R1]; D1 -- Yes --> D2{D2}; D2 -- No --> R2[R2]; D2 -- Yes --> S5([S5]); S5 --> S2;
+```
+
+T.803(21)\_FB.1
+
+|                                        |                                         |
+|----------------------------------------|-----------------------------------------|
+| S1: Select first test codestream (TCS) | D1: Any error metrics within tolerance? |
+| S2: Decode TCS with IUT                | D2: More tests?                         |
+| S3: Convert outputs of decoder         | R1: Decoder failed compliance           |
+| S4: Compare with reference image       | R2: Decoder passed compliance           |
+| S5: Select next TCS                    |                                         |
+
+Flowchart for Decoder compliance test procedure. Steps S1 to S5, decisions D1 and D2, and results R1 and R2.
+
+Figure B.1 – Decoder compliance test flow chart
+
+The following steps for testing the set of codestreams are shown in Figure B.1:
+
+- a) each relevant codestream is decoded using the decoder under test;
+- b) the decoded outputs are format converted if necessary;
+- c) the difference between the decoded outputs and reference images are measured; and
+- d) the measurements are compared with the limits for the particular image and compliance class.
+
+These steps are defined in more detail below. Failure to meet the tolerance limits for a single image results in the decoder failing to be compliant at the profile and Cclass being tested.
+
+The relevant codestreams for testing a J2K decoder consist of each J2K test codestream in the ETS that belongs to the profile against which the IUT claims compliance. For example, to test a J2K decoder against Profile-0, each TCS with the prefix "p0" is used in the compliance testing procedure.
+
+The relevant codestreams for testing an HTJ2K decoder consist of the highest precision compatible TCS from each subset of the ETS consisting of HTJ2K test codestreams that differ only by  $B_{MAGB}$  value (BSET) in the ETS that belongs to the derived set against which the IUT claims compliance. A BSET is a collection of test codestreams that differ by  $B_{MAGB}$  value, but otherwise represent the same content, with the same coding parameters. The highest precision compatible test codestream from a BSET is the one with the largest  $B_{MAGB}$  value that is no larger than the  $M_{MAGB}$  limit claimed by the IUT. For example, if a BSET contains codestreams with suffix "\_b11" and "\_b13", the first one is used for testing an IUT whose claimed  $M_{MAGB}$  limit is smaller than 13, while the second is used for testing an IUT whose claimed  $M_{MAGB}$  limit is 13 or more. Each BSET in the electronic attachment includes one test codestream with  $B_{MAGB}$  no larger than 11, and the minimum  $M_{MAGB}$  value for the lowest defined Cclass is 11, so all BSETs can be used in testing an HTJ2K decoder for compliance with each defined Cclass.
+
+### B.2.1 Files for testing
+
+A particular ETS defines the codestreams, output images, and error tolerances. This is done in Annex C for four fundamental compliance points (two Cclasses and two profiles), which are split into eight derived compliance points for HTJ2K decoders (two Cclasses and four derived sets).
+
+### B.2.2 Decoder settings
+
+Decoders may have mechanisms for supporting various decompression settings. These may be set in the most advantageous way to achieve compliance. For example, a decoder with a "fast mode" and an "accurate mode" may be set to the "accurate mode" for compliance. These settings should be noted in any statement of compliance. Settings that allow the output resolution or spatial region of the reference decoded images to be matched may be changed for each decoded image. The same user controlled settings for accuracy or quantization reconstruction factor of wavelet coefficients shall be used for all test codestreams.
+
+For each reference decoded image it is useful to know the output resolution and spatial extent; this is provided with the ETS. All reference decoded images begin at the upper left corner of the TCS image area and include decoded tiles up to the width and height declared in these tables. The reduction in resolution from the full TCS resolution is provided in these tables, as well. For Cclass 0, when several reference decoded images are provided for a single test codestream, the decoder output need only be compared with one of the reference image choices.
+
+#### B.2.3 Output file format conversion
+
+The reference decoded images are provided in a specific format defined below. In order to compare decoded images from the decoder under test with these images, several conversions may be necessary. These conversions are done as post-processing steps outside of the decoder solely for determining compliance. There is no requirement for a compliant decoder to perform these processes as part of its normal operation. These conversions shall not introduce a quality change (either loss or gain) except as required by the specific conversions described in the following subclauses.
+
+#### B.2.3.1 Order-dependent conversions
+
+The following post-processing conversions, if required, shall be performed in the indicated order and prior to the order-independent conversions.
+
+##### B.2.3.1.1 Scaling
+
+Decoders may produce a high resolution image even when testing for a low Cclass. For example, a full  $256 \times 256$  component from Profile-0 test codestream 3 might be produced by a decoder attempting to pass Cclass 0. The reference image for Cclass 0 is only  $128 \times 128$ . Thus, the decoded image shall be scaled to  $128 \times 128$ . Components should be scaled by applying the forward wavelet transform (5-3 or 9-7 according to which was used to decode the component) and keeping only the required low pass sub-band. It is preferable but not required for decoders to be able to decode any desired
+
+resolution. The reference images were created by decoding the number of wavelet decomposition levels specified in the tables for each test.
+
+##### B.2.3.1.2 Multiple component transform
+
+For Cclass 0 only, a decoder can decode a single component. For multiple component images this will be the first codestream component, which may correspond to the luminance of the multi-component image. A decoder that decodes 3 components from the image and performs the inverse colour transform shall use post-processing to extract a single-component image to be compared with the reference image. This post-processing consists of a forward colour transform and extraction of the first component of the output. If the components were transformed with the 9-7 filter, the forward ICT from Rec. ITU-T T.800 | ISO/IEC 15444-1 shall be used. If the components were transformed with the 5-3 reversible filter, the forward RCT from Rec. ITU-T T.800 | ISO/IEC 15444-1 shall be used.
+
+##### B.2.3.1.3 Conversion to integer
+
+A decoder producing floating point output samples shall have the samples converted to the nearest integer.
+
+##### B.2.3.1.4 Clipping
+
+Because of quantization and potential differences in the forward and inverse wavelet transforms, decoded component samples may be outside their nominal range. They shall be clipped as follows for unsigned components:
+
+$$x_{\text{clipped}} = \begin{cases} 0, & x_{\text{unclipped}} < 0 \\ x_{\text{unclipped}}, & 0 \leq x_{\text{unclipped}} < 2^D \\ 2^D - 1, & 2^D \leq x_{\text{unclipped}} \end{cases} \quad (\text{B-1})$$
+
+where  $D$  is the bit-depth of the component. For signed components, clipping is defined as:
+
+$$x_{\text{clipped}} = \begin{cases} -2^{D-1}, & x_{\text{unclipped}} < -2^{D-1} \\ x_{\text{unclipped}}, & -2^{D-1} \leq x_{\text{unclipped}} < 2^{D-1} \\ 2^{D-1} - 1, & 2^{D-1} \leq x_{\text{unclipped}} \end{cases} \quad (\text{B-2})$$
+
+where  $D$  is the bit-depth of the component.
+
+##### B.2.3.1.5 Bit-depth scaling
+
+The decoded images shall be scaled to the smaller of the image component bit-depth and the compliance class bit-depth. For example, if a decoder decodes a 12-bit component into the most significant bits of a 16-bit word, the component shall be scaled to 8 bits per sample for a Cclass 0 decoder test. If the decoder produces an 8-bit component for a codestream with a 4-bit component, the component shall be scaled to 4-bits per sample. The scaling shall be implemented by simple arithmetic shifts. This can be expressed as:
+
+$$x_{\text{scaled}} = \left\lfloor \frac{x_{\text{unscaled}}}{2^{d-r}} \right\rfloor \quad (\text{B-3})$$
+
+where  $d$  is the nominal bit-depth of the decoded component,  $r$  is the bit-depth of the reference image and  $\lfloor \cdot \rfloor$  is the arithmetic floor function that rounds its argument downwards to the nearest integer.
+
+###### B.2.3.1.6 Subsampling
+
+All reference components contain the number of samples expected from Rec. ITU-T T.800 | ISO/IEC 15444-1, restricted to  $H$  and  $W$  for the Cclass. For testing purposes, it is preferable for a decoder to not upsample the image (e.g., by replication by  $XR_{\text{SIZ}}^C$  or  $YR_{\text{SIZ}}^C$  to create a component the size of the reference grid). If such upsampling cannot be turned off, a post-processing step to subsample the upsampled image shall be used to return the component to the appropriate size.
+
+###### B.2.3.1.7 Cropping
+
+Decoders may have the capability to decode the entire image when presented with a test codestream, and in some cases this may yield an image that is larger than the  $H$  and  $W$  requirements for the Cclass being tested. In such cases, the decoded image shall be cropped for testing purposes, leaving the upper left corner to be the size of the appropriate reference image for the Cclass being tested. Cropping is accomplished by discarding all samples outside of the dimensions of the reference component.
+
+NOTE – For a decoder of a given Cclass, there may be several possible ways to produce an output image that satisfies the  $H$  and  $W$  requirements for that Cclass. The possibilities will depend upon the specific capabilities of the decoder, the size of the image and its tiles, and the number of decomposition levels present in each tile. The reference images for each codestream are produced in one of two ways when possible. First, the decoder processes the first image tile to its maximum resolution consistent with the size constraint for the given Cclass. If possible, additional tiles are included at the same resolution to bring the final output image size as near as possible to the Cclass  $H$  and  $W$  size limits. (Note that this implies the tiles are produced at full resolution.) Second, the decoder processes all tiles of the image at a common resolution consistent with the Cclass  $H$  and  $W$  size limits. This latter strategy produces something similar to a thumbnail or overview image, typically at a resolution reduced from that of the original image.
+
+##### B.2.3.2 Order-independent conversions
+
+The following post-processing conversions, if required, shall be performed after any order-dependent conversions. These conversions may be applied in any convenient order.
+
+###### B.2.3.2.1 Component de-interleaving
+
+Decoded images in interleaved format (e.g., one red sample followed by one green sample followed by one blue sample) shall be converted to one file per component.
+
+###### B.2.3.2.2 Endianness
+
+All reference images are stored in big endian (i.e., with most significant byte first). If the decoded image is produced in little endian format then the bytes shall be swapped for comparison purposes.
+
+###### B.2.3.2.3 Sign extend to byte boundary
+
+All reference images are stored with either 8 or 16 bits per sample. For example, 4- and 12-bit component samples shall be padded in the most significant bit positions with an additional 4 bits. These bits shall be "1" for negative samples in signed images and "0" for all other samples. The sign extension shall properly account for the endianness of the samples.
+
+### B.2.4 Compare decoded and formatted components with reference components
+
+Once the decoded image has been properly formatted it is compared with the reference image. The reference components for each Cclass are listed in the tables defining the ETS. The decoded components shall be compared separately for all components for which there is a reference decoded image. For each component, the MSE shall be determined as follows:
+
+$$\text{MSE} = \frac{1}{N} \sum_{i=1}^N (x_i - \hat{x}_i)^2 \quad (\text{B-4})$$
+
+where  $N$  is the number of samples in the component (reference width times reference height),  $x_i$  is a sample from the reference image, and  $\hat{x}_i$  is the corresponding sample from the decoded and formatted image.
+
+The Peak error,  $p$ , shall be determined as follows:
+
+$$p = \text{MAX}_{i=1}^N \left| x_i - \hat{x}_i \right| \quad (\text{B-5})$$
+
+### B.2.5 Compare error metrics with specification
+
+Each ETS defines a peak error and MSE error for each test codestream and reference decoded image. These are defined in Annex C.
+
+For the Cclass0 tests, only the first codestream image component is decoded. Any ICT or RCT indicated in the codestream is not performed. When multiple reference files are provided, the decoder output shall be tested against at least one of these references.
+
+Other Cclasses require decoding multiple components. Separate reference images are provided for each component which has to be decoded, with the suffix  $C$ , which indicates the component number. The IUT shall make comparisons for all the component reference files listed in tables defining the ETS.
+
+### B.2.6 Reference components file format
+
+This subclause describes the file format, called PGX, of the reference images used for comparison with the output of the decoder under test. The decoder under test is not required to produce this particular file format. Any necessary conversion, as specified in B.2.3, may be applied. The reference decoded files are stored with one file per component. There is also a header line that describes the size of the components.
+
+NOTE – In some operating systems the PGX test files provided may be split into a header only file and a raw data file with no header using the commands 'head -1 file.pgx >header.txt' and 'tail +1 file.pgx >file.raw'.
+
+#### B.2.6.1 Header format
+
+The header used by the reference images consists of a single text line of the form:
+
+PG <byte order> [+<bit-depth> <width> <height> <newline>
+
+Each of the fields is separated by one space character, 0x20.
+
+<byte order> literal "ML" (0x4D, 0x4C)
+
+NOTE – Some PGX writers will use the literal "LM" to indicate least significant byte first. This is not used by the reference images with this Recommendation | International Standard.
+
+[+<bit-depth> If this field begins with an ASCII digit or a '+' character, the image data is unsigned; if the field begins with a '-' character the data is signed. The ASCII value indicates the bit-depth. There may be a space (0x20) between the sign ('+' or '-') and the bit-depth.
+
+<width> the number of samples horizontally for the image. There are no offsets or subsampling with this format.
+
+<height> the number of samples vertically for the image. There are no offsets or subsampling with this format.
+
+<newline> may consist of the two bytes 0x0d, 0x0a, or the single character 0x0a, the character 0x0a shall be the last before the beginning of the raw data and will always be present.
+
+Example – PG ML +8 128 128
+
+##### B.2.6.2 Data format
+
+The binary data appears immediately after the 0x0a byte in the header. The data in the raw file is stored most significant byte first using 1, 2, or 4 bytes per sample. One byte is used for component depths of 1 to 8 bits, two bytes are used for component depths of 9 to 16 bits, and four bytes are used for depths of 17 to 32 bits. Signed data is stored in 2's complement, with sign extension throughout the 1, 2, or 4 bytes (e.g., -1 is stored as 0xFFFF for a 12-bit signed image).
+
+# Annex C
+
+## Compliance tests
+
+(This annex forms an integral part of this Recommendation | International Standard.)
+
+This annex specifies the ATSs and ETSs that will be used in the compliance test procedures from Annex B.
+
+## C.1 Abstract test suite (informative)
+
+The ATS defines the general tests for components of Rec. ITU-T T.800 | ISO/IEC 15444-1 and Rec. ITU-T T.814 | ISO/IEC 15444-15. The lists in this subclause are used to define the decoder ETS and could be used to develop additional encoder or decoder ETSs.
+
+### C.1.1 Syntax and compressed data order
+
+- a) Test purpose: To test the ability of an implementation to encode and decode codestreams with optional markers, marker values, and markers in different locations in the codestream.
+- b) Test method: Using lossless codestreams, encode or decode several different codestreams with variations of markers, marker values, and marker locations. Parameters and existence of markers may be limited by the profile being tested. Specific test items include:
+  - location of markers in codestream: optional markers in different positions of the codestream;
+  - priority of markers: markers in the codestream that override previous markers;
+  - proper use of the pointer markers: tile-part length (TLM), packet length, tile-part header (PLT), packet length, main header (PLM) correct;
+  - image offsets:  $XO_{SIZ}$  and  $YO_{SIZ}$  with several values including odd, even, large, and small;
+  - tile dimensions: several size tiles including odd, even, very small tiles;
+  - tile offsets:  $XTO_{SIZ}$  and  $YTO_{SIZ}$  with several values including odd and even;
+  - component subsampling:  $XR_{SIZ}$  and  $YR_{SIZ}$  with several values including odd and even;
+  - code-blocks dimensions: all values;
+  - progression orders: five progression orders, POCs;
+  - packet headers: include start of packet (SOP) and end of packet header (EPH), number of layers, different locations of packet headers (main header, tile-part header, codestream), bit stuffing;
+  - precincts: having several values of precinct sizes (including different for each sub-band and a precinct that is smaller than the code-block sizes), precinct and tile boundaries equivalent at low resolution, different at high resolution;
+  - precincts containing no data, resolution levels containing no valid coefficient, precincts that have no coefficients in several/all bands;
+  - packet-non-empty bit of the packet header;
+  - sub-bands: with no precincts;
+  - tile-parts: placing the tile-parts in different locations in the codestream, POC in second tile-part.
+
+### C.1.2 Arithmetic entropy encoding
+
+- a) Test purpose: To evaluate the correct operation of the implementation of the arithmetic encoder within the IUT.
+- b) Test method: Losslessly compressed images using different combinations of options. Can change within a single image by changing the options in each tile. Encode, or decode several different codestreams with different arithmetic entropy coding parameters. Specific test options include:
+  - arithmetic coder bypass;
+  - context reset on coding pass boundaries;
+  - termination on each coding pass;
+  - vertically causal context;
+  - predictable termination;
+  - segmentation symbols;
+
+- combinations of options.
+
+### C.1.3 Coefficient bit modelling
+
+- a) Test purpose: To test the correct operation of the coefficient bit modelling of the arithmetic encoding of the IUT.
+- b) Test method: Encode, or decode several different codestreams with all possible neighbouring location contexts. Test all contexts occurring in all sub-band types and with and without vertically causal contexts.
+
+### C.1.4 Quantization
+
+- a) Test purpose: To test the accuracy of the quantization implementation of the IUT.
+- b) Test method: Encode or decode several different codestreams with zero levels of decomposition in the wavelet transform so that the quantization is the only parameter being tested. The accuracy is tested with MSE and max error. Specific items to test include:
+  - exponent and mantissa;
+  - guard bits;
+  - dequantization offset value;
+  - derived and explicit quantization.
+
+### C.1.5 Discrete wavelet transform
+
+- a) Test purpose: To test the accuracy of the implementation of the two discrete wavelet transforms.
+- b) Test method: Encode or decode several different codestreams with the two filters, varying the tile size, and number of levels, and test the accuracy of each of the filters. The accuracy of the 9-7 filter shall be defined by MSE and max error while the 5-3 filter shall have no difference. Specific items to test include:
+  - precision of 9-7;
+  - reversibility of 5-3;
+  - number of decomposition levels, including 0;
+  - different offset conditions and tile sizes, very small sub-bands down to  $1 \times 1$ , empty sub-bands, one column sub-bands, one-row sub-bands;
+  - saturation conditions.
+
+### C.1.6 DC level shift and multiple component transform
+
+- a) Test purpose: To test the ability of the implementation to achieve the DC level shift and the accuracy of the two multiple component transforms.
+- b) Test method: Encode or decode several different codestreams with IUT using different combinations of options:
+  - component depth;
+  - component samples that are signed and unsigned;
+  - precision of ICT;
+  - correctness of RCT.
+
+### C.1.7 Region of interest
+
+- a) Test purpose: To test the correct implementation of ROI in the IUT.
+- b) Test method: Encode or decode several different images with regions of different size, number, shift value, different in each component:
+  - different ROI in each component;
+  - RGN marker in main and tile-part header, test for proper treatment of priorities;
+  - shift value;
+  - partial decoding of an image with ROI.
+
+### C.1.8 JP2 file format
+
+- a) Test purpose: To test the ability of the implementation to accurately represent the JPEG 2000 compressed data within the JP2 file format.
+- b) Test method: Encode or decode several different codestreams with different parameters of the file format.
+
+### C.1.9 High throughput cleanup pass coding
+
+- a) Test purpose: To evaluate the correct operation of the implementation of the high throughput (HT) Cleanup pass coder within the IUT.
+- b) Test method: Losslessly compressed images of various dimensions, with different values of the vertically causal context mode flag (bit-3 of SPcod/SPcoc) . Can change within a single image by changing the options in each tile.
+
+### C.1.10 HT refinement pass coding
+
+- a) Test purpose: To evaluate the correct operation of the implementation of the HT block coder within the IUT, including Cleanup, SigProp and MagRef coding passes.
+- b) Test method: Transcode reversibly transformed but lossy compressed J2K codestreams to HTJ2K codestreams, so as to preserve the truncation boundaries of the original block bit-streams. Verify that the decoded J2K and HTJ2K codestreams produce identical images.
+
+### C.1.11 Placeholder passes
+
+- a) Test purpose: To evaluate the correct formation of packet headers within the IUT, where multiple quality layer boundaries are to be recorded in a codestream that uses the HT block coding algorithm without multiple HT Sets.
+- b) Test method: Transcode reversibly transformed J2K codestreams with multiple quality layers to HTJ2K codestreams with corresponding quality layers and packets for each precinct, so as to preserve the original coded values exactly using at most one HT Set for each code-block. Verify that the decoded J2K and HTJ2K codestreams produce identical images. Verify that the HTJ2K codestream can be transcoded back to a non-HTJ2K codestream and that truncating this codestream and the original J2K codestream to a reduced number of quality layers results in the same image upon decoding.
+
+### C.1.12 Mixing of HT and J2K code-blocks within HTJ2K codestreams
+
+- a) Test purpose: To evaluate the correct construction of JPEG 2000 packets in the case where both HT and J2K code-blocks may be present in a packet – bits 6 and 7 of SPcod/SPcoc are both set to 1 in this case.
+- b) Test method: Selectively transcode some code-blocks of a losslessly compressed J2K codestream to HT code-blocks, leaving the other code-blocks as J2K code-blocks, and regenerate JPEG 2000 packets to correctly signal and encapsulate the transcoded content. Decode the resulting J2K and HTJ2K codestreams and verify that they are identical.
+
+### C.1.13 JPH File format
+
+- a) Test purpose: To test the ability of the implementation to accurately represent the JPEG 2000 compressed data within the JPH file format.
+- b) Test method: Encode or decode several different HTJ2K codestreams with different parameters of the file format. Alternatively, transcode JP2 files with their embedded J2K codestreams to JPH files with embedded HTJ2K codestreams.
+
+## C.2 Executable test suite
+
+The ETSs are the embodiment of the ATS. Commonly several ATSs are embodied in one ETS. This subclause defines four ETSs for J2K decoders, namely Cclass 0 and Cclass 1 decoders for Profile-0 and Profile-1 codestreams. There are 16 test codestreams defined for Profile 0 and 7 test codestreams defined for Profile-1 (Profile-1 compliance requires both Profile-0 and Profile-1 test codestreams). The tolerance values are defined as a function of Cclass for each image and may be more difficult to achieve as Cclass increases for each image.
+
+Each ETS consists of codestreams, reference decoded images, and tolerance values for MSE and peak error. In addition, some information is provided about the test codestreams, which may aid correction of a non-compliant decoder. This information consists of a table listing many of the markers in the codestream, the offset into the codestream where those markers occur and the value of the parameters of those markers.
+
+ETSs for testing HTJ2K decoders are derived from the J2K ETSs. The tolerance values for each HTJ2K Cclass are identical to those for the J2K Cclass from which it was derived. The transcoding of each of the 16 J2K test codestreams results in a single HTJ2K BSET, belonging to one of the derived sets listed in Table 1. The HTJ2K test codestreams in each BSET have different  $B_{MAGB}$  parameter values. One test codestream in each BSET has  $B_{MAGB} \leq 11$ .
+
+### C.2.1 Class 0 Profile-0
+
+#### C.2.1.1 Codestreams
+
+The J2K test codestreams for this ETS are in the directory `codestreams_profile0`. There are 16 codestreams, with names of the form `p0_##.j2k`, where `##` is the codestream number.
+
+The derived HTJ2K BSETs for this ETS are in the directory `htj2k_bsets_profile0`. There are 16 BSETs, with names of the form `p0_##_bset`, where `##` is the J2K codestream number. Each BSET is a directory, containing codestreams with names of the form `ds0_ht_##_b$.j2k` or `ds0_hm_##_b$.j2k`, where `##` is the J2K codestream number and `$` is the  $B_{MAGB}$  value. Names of the first form are used for HTJ2K codestreams that are HTONLY, in which case the codestream belongs to derived set DS0-HT; otherwise, the second form of the name is used and the codestream belongs to derived set DS0-HM.
+
+#### C.2.1.2 Reference decoded images
+
+The reference decoded images for this ETS are in the directory `reference_class0_profile0`. The filenames are of the form `c0p0_##[rN].pgx`, where `##` is the codestream number, and `N` is the number of inverse wavelet transforms that have been skipped in the decoding of the codestream. A 0 indicates a full resolution image (typically this is cropped to the upper left corner). A 1 indicates an image with resolution reduced by  $2^1$  in each dimension.
+
+The same reference decoded images are used when testing both HTJ2K and J2K decoders.
+
+#### C.2.1.3 Tolerances
+
+The maximum allowable MSE and peak errors are listed in Table C.1, along with the size of the reference decoded images.
+
+Table C.1 – Class 0 Profile-0 reference images and allowable errors
+
+| TCS       | Reference file | Resolution reduction | Signed | Depth | Width | Height | Peak | MSE  |
+|-----------|----------------|----------------------|--------|-------|-------|--------|------|------|
+| p0_01.j2k | c0p0_01.pgx    | 0                    | +      | 8     | 128   | 128    | 0    | 0    |
+| p0_02.j2k | c0p0_02.pgx    | 0                    | +      | 8     | 64    | 126    | 0    | 0    |
+| p0_03.j2k | c0p0_03r0.pgx  | 0                    | –      | 4     | 128   | 128    | 0    | 0    |
+|           | c0p0_03r1.pgx  | 1                    | –      | 4     | 128   | 128    | 0    | 0    |
+| p0_04.j2k | c0p0_04.pgx    | 3                    | +      | 8     | 80    | 60     | 33   | 55.8 |
+| p0_05.j2k | c0p0_05.pgx    | 3                    | +      | 8     | 128   | 128    | 54   | 68   |
+| p0_06.j2k | c0p0_06.pgx    | 3                    | +      | 8     | 65    | 17     | 109  | 743  |
+| p0_07.j2k | c0p0_07.pgx    | 0                    | –      | 8     | 128   | 128    | 10   | 0.34 |
+| p0_08.j2k | c0p0_08.pgx    | 5                    | –      | 8     | 17    | 96     | 7    | 6.72 |
+| p0_09.j2k | c0p0_09.pgx    | 2                    | +      | 8     | 5     | 10     | 4    | 1.47 |
+| p0_10.j2k | c0p0_10.pgx    | 0                    | +      | 8     | 64    | 64     | 10   | 2.84 |
+| p0_11.j2k | c0p0_11.pgx    | 0                    | +      | 8     | 128   | 1      | 0    | 0    |
+| p0_12.j2k | c0p0_12.pgx    | 0                    | +      | 8     | 3     | 5      | 0    | 0    |
+| p0_13.j2k | c0p0_13.pgx    | 0                    | +      | 8     | 1     | 1      | 0    | 0    |
+| p0_14.j2k | c0p0_14.pgx    | 2                    | +      | 8     | 13    | 13     | 0    | 0    |
+|           | c0p0_15r0.pgx  | 0                    | –      | 4     | 128   | 128    | 0    | 0    |
+| p0_15.j2k | c0p0_15r1.pgx  | 1                    | –      | 4     | 128   | 128    | 0    | 0    |
+|           | c0p0_16.pgx    | 0                    | +      | 8     | 128   | 128    | 0    | 0    |
+
+NOTE – See A.1.7 for advice regarding the reconstruction parameter `r` when testing decoder implementations against these error bounds.
+
+The values in Table C.1 are used when testing both HTJ2K and J2K decoders. However, when testing an HTJ2K decoder, the allowable MSE and peak errors may be increased, depending on the  $M_{MAGB}$  limit claimed by the IUT, in accordance with the values provided in Table C.1bis, applying the bit-depth dependent scaling specified in Table C.1bis.
+
+Table C.1bis – Additional allowable errors for HTJ2K TCSs belonging to derived set 0
+
+| TCS                                                                                                                                                                                                                                                                                      | $B_{MAGB}$ | Reference Depth | Component 0 |       | Component 1 |       | Component 2 |       | Component 3 |       |
+|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------|-----------------|-------------|-------|-------------|-------|-------------|-------|-------------|-------|
+|                                                                                                                                                                                                                                                                                          |            |                 | Peak        | MSE   | Peak        | MSE   | Peak        | MSE   | Peak        | MSE   |
+| ds0_ht_01_b11.j2k                                                                                                                                                                                                                                                                        | 11         | 8               | 0           | 0     |             |       |             |       |             |       |
+| ds0_ht_02_b11.j2k                                                                                                                                                                                                                                                                        | 11         | 8               | 1           | 0.001 |             |       |             |       |             |       |
+| ds0_ht_02_b12.j2k                                                                                                                                                                                                                                                                        | 12         | 8               | 0           | 0     |             |       |             |       |             |       |
+| ds0_ht_03_b11.j2k                                                                                                                                                                                                                                                                        | 11         | 4               | 17          | 0.15  |             |       |             |       |             |       |
+| ds0_ht_03_b14.j2k                                                                                                                                                                                                                                                                        | 14         | 4               | 0           | 0     |             |       |             |       |             |       |
+| ds0_ht_04_b11.j2k                                                                                                                                                                                                                                                                        | 11         | 8               | 2           | 0.1   | 2           | 0.1   | 2           | 0.1   |             |       |
+| ds0_ht_04_b12.j2k                                                                                                                                                                                                                                                                        | 12         | 8               | 0           | 0     | 0           | 0     | 0           | 0     |             |       |
+| ds0_ht_05_b11.j2k                                                                                                                                                                                                                                                                        | 11         | 8               | 0           | 0     | 1           | 0.001 | 1           | 0.001 | 2           | 0.001 |
+| ds0_ht_05_b12.j2k                                                                                                                                                                                                                                                                        | 12         | 8               | 0           | 0     | 0           | 0     | 0           | 0     | 0           | 0     |
+| ds0_ht_06_b11.j2k                                                                                                                                                                                                                                                                        | 11         | 12              | 2500        | 75000 | 0           | 0     | 0           | 0     | 200         | 2000  |
+| ds0_ht_06_b15.j2k                                                                                                                                                                                                                                                                        | 15         | 12              | 0           | 0     | 0           | 0     | 0           | 0     | 12          | 10.0  |
+| ds0_ht_06_b18.j2k                                                                                                                                                                                                                                                                        | 18         | 12              | 0           | 0     | 0           | 0     | 0           | 0     | 0           | 0     |
+| ds0_hm_06_b11.j2k                                                                                                                                                                                                                                                                        | 11         | 12              | 0           | 0     | 0           | 0     | 0           | 0     | 200         | 2000  |
+| ds0_hm_06_b18.j2k                                                                                                                                                                                                                                                                        | 18         | 12              | 0           | 0     | 0           | 0     | 0           | 0     | 0           | 0     |
+| ds0_ht_07_b11.j2k                                                                                                                                                                                                                                                                        | 11         | 12              | 40          | 25.0  | 40          | 25.0  | 50          | 25.0  |             |       |
+| ds0_ht_07_b15.j2k                                                                                                                                                                                                                                                                        | 15         | 12              | 2           | 0.075 | 2           | 0.05  | 2           | 0.075 |             |       |
+| ds0_ht_07_b16.j2k                                                                                                                                                                                                                                                                        | 16         | 12              | 0           | 0     | 0           | 0     | 0           | 0     |             |       |
+| ds0_ht_08_b11.j2k                                                                                                                                                                                                                                                                        | 11         | 12              | 40          | 45.0  | 40          | 30.0  | 40          | 45.0  |             |       |
+| ds0_ht_08_b15.j2k                                                                                                                                                                                                                                                                        | 15         | 12              | 0           | 0     | 1           | 0.001 | 0           | 0     |             |       |
+| ds0_ht_08_b16.j2k                                                                                                                                                                                                                                                                        | 16         | 12              | 0           | 0     | 0           | 0     | 0           | 0     |             |       |
+| ds0_ht_09_b11.j2k                                                                                                                                                                                                                                                                        | 11         | 8               | 0           | 0     |             |       |             |       |             |       |
+| ds0_ht_10_b11.j2k                                                                                                                                                                                                                                                                        | 11         | 8               | 0           | 0     | 0           | 0     | 0           | 0     |             |       |
+| ds0_ht_11_b10.j2k                                                                                                                                                                                                                                                                        | 10         | 8               | 0           | 0     |             |       |             |       |             |       |
+| ds0_ht_12_b11.j2k                                                                                                                                                                                                                                                                        | 11         | 8               | 0           | 0     |             |       |             |       |             |       |
+| ds0_ht_13_b11.j2k                                                                                                                                                                                                                                                                        | 11         | 8               | 0           | 0     | 0           | 0     | 0           | 0     | 0           | 0     |
+| ds0_ht_14_b11.j2k                                                                                                                                                                                                                                                                        | 11         | 8               | 0           | 0     | 0           | 0     | 0           | 0     |             |       |
+| ds0_ht_15_b11.j2k                                                                                                                                                                                                                                                                        | 11         | 4               | 17          | 0.15  |             |       |             |       |             |       |
+| ds0_ht_15_b14.j2k                                                                                                                                                                                                                                                                        | 14         | 4               | 0           | 0     |             |       |             |       |             |       |
+| ds0_hm_15_b8.j2k                                                                                                                                                                                                                                                                         | 8          | 4               | 0           | 0     |             |       |             |       |             |       |
+| ds0_ht_16_b11.j2k                                                                                                                                                                                                                                                                        | 11         | 8               | 0           | 0     |             |       |             |       |             |       |
+| NOTE – When applied to the tolerances in Table C.1, the additional peak errors are scaled by $2^{D-D_{ref}}$ and rounded up, while the additional MSE values are scaled by $4^{D-D_{ref}}$ , where $D$ is the bit-depth in Table C.1 and $D_{ref}$ is the reference depth in this table. |            |                 |             |       |             |       |             |       |             |       |
+
+#### C.2.1.4 J2K test codestream descriptions (informative)
+
+Table C.2 describes the features being tested by the Profile-0 codestreams, while Table C.2bis describes the features being tested by the derived set 0 HTJ2K codestreams. This information is provided solely to help correction of non-compliant decoders when accuracy is not guaranteed.
+
+Table C.2 – Items tested by Profile-0 codestreams
+
+| Codestream | Tests                                                                                                                                                                                                                   |
+|------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| 1          | 5-3 wavelet, $64 \times 64$ code-blocks, MQ-coder, context model                                                                                                                                                        |
+| 2          | Component subsampling, multiple layers, termination every coding pass, predictable termination, segmentation symbols, COD, quantization default (QCD), EPH, SOP, and 0xFF30 marker segments, $32 \times 32$ code-blocks |
+| 3          | Multiple tiles, signed data, 4-bit/component data, quantization component (QCC), POC, component registration (CRG), TLM, and RGN marker segments                                                                        |
+| 4          | Multiple components, termination every coding pass, 9-7 wavelet, precinct sizes in COD, irreversible component transform, scalar expound quantization                                                                   |
+
+**Table C.2 – Items tested by Profile-0 codestreams**
+
+| <b>Codestream</b> | <b>Tests</b>                                                                                                      |
+|-------------------|-------------------------------------------------------------------------------------------------------------------|
+| 5                 | Different subsampling for different components, different wavelet filters and parameters for different components |
+| 6                 | 12-bit component samples, RGN in main and tile                                                                    |
+| 7                 | Large number of tiles                                                                                             |
+| 8                 | Large image                                                                                                       |
+| 9                 | 9-7 wavelet transform overflow                                                                                    |
+| 10                | Image source is pseudo-random, subsampling by 4, 0 guard bits, reversible colour transform, tile-parts            |
+| 11                | 1 sample high image, 0 decomposition level test, segmentation symbols                                             |
+| 12                | Special wavelet transform cases                                                                                   |
+| 13                | Large number of components                                                                                        |
+| 14                | 5-3 wavelet transform saturation                                                                                  |
+| 15                | RGN, POC, Signed, QCC, comment (COM)                                                                              |
+| 16                | Empty packet header bit                                                                                           |
+
+**Table C.2bis – Items tested by derived set 0 HTJ2K codestreams**
+
+| <b>Codestream BSET</b> | <b>Tests</b>                                                                                                                                                                   |
+|------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| 1                      | 5-3 wavelet, 64 × 64 code-blocks                                                                                                                                               |
+| 2                      | Component subsampling, COD, QCD, EPH, SOP, 32 × 32 code-blocks, multiple layers with placeholder passes                                                                        |
+| 3                      | Multiple tiles, signed data, 4-bit/component data, QCC, POC, CRG, TLM, and RGN marker segments, multiple layers with placeholder passes. HTJ2K features: HETEROGENEOUS and RGN |
+| 4                      | Multiple components, 9-7 wavelet, precinct sizes in COD, irreversible component transform, scalar expound quantization, multiple layers with placeholder passes                |
+| 5                      | Different subsampling for different components, different wavelet filters and parameters for different components, multiple layers with placeholder passes                     |
+| 6                      | 12-bit component samples, RGN in main and tile headers, multiple layers with placeholder passes. HTJ2K features: HETEROGENEOUS, RGN and MIXED                                  |
+| 7                      | Large number of tiles, POC, multiple layers with placeholder passes. HTJ2K features: HETEROGENEOUS                                                                             |
+| 8                      | Large image, multiple layers with placeholder passes.                                                                                                                          |
+| 9                      | 9-7 wavelet transform overflow                                                                                                                                                 |
+| 10                     | Image source is pseudo-random, subsampling by 4, 0 guard bits, reversible colour transform, tile-parts, multiple layers with placeholder passes                                |
+| 11                     | 1 sample high image, 0 decomposition level test                                                                                                                                |
+| 12                     | Special wavelet transform cases                                                                                                                                                |
+| 13                     | Large number of components. HTJ2K features: RGN                                                                                                                                |
+| 14                     | 5-3 wavelet transform saturation                                                                                                                                               |
+| 15                     | RGN, POC, Signed, QCC, COM, multiple layers with placeholder passes. HTJ2K features: HETEROGENEOUS, RGN and MIXED                                                              |
+
+The directory **descriptions\_profile0** contains information about every J2K test codestream. The information is of the type shown in Table C.3. Similarly, the directory **descriptions\_htj2k\_profile0** contains information about every HTJ2K test codestream.
+
+Table C.3 – Profile-0 codestream 0 contents
+
+| Offset | Item                                                                                                                                                                                                                                                                                                                                                                                                                                                                  | Value                                                                                                                                                       |
+|--------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| 0      | SOC (start of codestream)                                                                                                                                                                                                                                                                                                                                                                                                                                             |                                                                                                                                                             |
+| 2      | SIZ (Image and tile size)<br>Required Capabilities<br>Reference Grid Size<br>Image Offset<br>Reference Tile Size<br>Reference Tile Offset<br>Components<br>Component #0 Depth<br>Component #0 Signed<br>Component #0 Sample Separation                                                                                                                                                                                                                                | JPEG 2000 Profile-0<br>128 × 128<br>0 × 0<br>128 × 128<br>0 × 0<br>1<br>8<br>no<br>1 × 1                                                                    |
+| 45     | QCD (Quantization default)<br>Quantization Type<br>Guard Bits<br>Exponent #0<br>Exponent #1<br>Exponent #2<br>Exponent #3<br>Exponent #4<br>Exponent #5<br>Exponent #6<br>Exponent #7<br>Exponent #8<br>Exponent #9                                                                                                                                                                                                                                                   | None<br>2<br>8<br>9<br>9<br>10<br>9<br>9<br>10<br>9<br>9<br>9<br>10                                                                                         |
+| 60     | COD (Coding style default)<br>Default precincts of $2^{15} \times 2^{15}$<br>SOP marker segments<br>EPH marker segments<br>All Flags<br>Progression Order<br>Layers<br>Multiple Component Transformation<br>Decomposition Levels<br>Code-block size<br>Selective Arithmetic Coding Bypass<br>Reset Context Probabilities<br>Termination on Each Coding Pass<br>Vertically Causal Context<br>Predictable Termination<br>Segmentation Symbols<br>Wavelet Transformation | Yes<br>No<br>No<br>00000000<br>Resolution level-layer-component-position<br>1<br>None<br>3<br>64 × 64<br>No<br>No<br>No<br>No<br>No<br>No<br>5-3 reversible |
+| 74     | SOT (start of tile-part)<br>Tile<br>Length<br>Index<br>Tile-Parts                                                                                                                                                                                                                                                                                                                                                                                                     | 0<br>7314<br>0<br>1                                                                                                                                         |
+| 7388   | EOC (End of codestream)                                                                                                                                                                                                                                                                                                                                                                                                                                               |                                                                                                                                                             |
+
+### C.2.2 Class 0 Profile-1
+
+#### C.2.2.1 Codestreams
+
+The J2K test codestreams for this ETS are in the directory **codestreams\_profile1**. The codestream names have the form **p1\_##.j2k**, where **##** is the codestream number. In addition to passing the test for all these codestreams, a decoder shall also pass the Class 0 Profile-0 test to pass the Class 0 Profile-1 test.
+
+The derived HTJ2K BSETs for this ETS are in the directory **htj2k\_bsets\_profile1**. The BSETs in this directory have names of the form **p1\_##\_bset**, where **##** is the J2K codestream number. Each BSET is a directory, containing codestreams with names of the form **ds1\_ht\_##\_b\$.j2k** or **ds1\_hm\_##\_b\$.j2k**, where **##** is the J2K codestream number and **\$** is the  $B_{MAGB}$  value. Names of the first form are used for HTJ2K codestreams that are HTONLY, in which case the codestream belongs to derived set DS1-HT; otherwise, the second form of the name is used and the codestream belongs to derived set DS1-HM.
+
+#### C.2.2.2 Reference decoded images
+
+The reference decoded images for this ETS are in the directory **reference\_class0\_profile1**. The filenames are of the form **c0p1\_##[rN].pgx**, where **##** is the codestream number, **N** is the number of inverse wavelet transforms that have been skipped in the decoding of the codestream.
+
+The same reference decoded images are used when testing both HTJ2K and J2K decoders.
+
+#### C.2.2.3 Tolerances
+
+The maximum allowable MSE and peak errors are listed in Table C.4, along with the size of the reference decoded images. These values are used when testing both HTJ2K and J2K decoders. However, when testing an HTJ2K decoder, the allowable MSE and peak errors may be increased, depending on the  $M_{MAGB}$  limit claimed by the IUT, in accordance with the values provided in Table C.4bis.
+
+Table C.4 – Class 0 Profile-1 reference images and allowable errors
+
+| TCS       | Reference file | Resolution reduction | Depth | Width | Height | Peak | MSE   |
+|-----------|----------------|----------------------|-------|-------|--------|------|-------|
+| p1_01.j2k | c0p1_01.pgx    | 0                    | 8     | 61    | 99     | 0    | 0     |
+| p1_02.j2k | c0p1_02.pgx    | 3                    | 8     | 80    | 60     | 35   | 74.0  |
+| p1_03.j2k | c0p1_03.pgx    | 3                    | 8     | 128   | 128    | 28   | 18.8  |
+| p1_04.j2k | c0p1_04r0.pgx  | 0                    | 8     | 128   | 128    | 2    | 0.550 |
+|           | c0p1_04r3.pgx  | 3                    | 8     | 128   | 128    | 128  | 2042  |
+| p1_05.j2k | c0p1_05.pgx    | 4                    | 8     | 32    | 32     | 128  | 16384 |
+| p1_06.j2k | c0p1_06.pgx    | 1                    | 8     | 6     | 6      | 128  | 16384 |
+| p1_07.j2k | c0p1_07.pgx    | 0                    | 8     | 2     | 12     | 0    | 0     |
+
+NOTE – See A.1.7 for advice regarding the reconstruction parameter *r* when testing decoder implementations against these error bounds.
+
+Table C.4bis – Additional allowable errors for HTJ2K TCSs belonging to derived set 1
+
+| TCS               | $B_{MAGB}$ | Reference depth | Component 0 |       | Component 1 |      | Component 2 |      | Component 3 |       |
+|-------------------|------------|-----------------|-------------|-------|-------------|------|-------------|------|-------------|-------|
+|                   |            |                 | Peak        | MSE   | Peak        | MSE  | Peak        | MSE  | Peak        | MSE   |
+| ds1_ht_01_b11.j2k | 11         | 8               | 1           | 0.001 |             |      |             |      |             |       |
+| ds1_ht_01_b12.j2k | 12         | 8               | 0           | 0     |             |      |             |      |             |       |
+| ds1_ht_02_b11.j2k | 11         | 8               | 2           | 0.1   | 2           | 0.1  | 2           | 0.1  |             |       |
+| ds1_ht_02_b12.j2k | 12         | 8               | 0           | 0     | 0           | 0    | 0           | 0    |             |       |
+| ds1_ht_03_b11.j2k | 11         | 8               | 0           | 0     | 1           | 0.03 | 2           | 0.05 | 2           | 0.001 |
+| ds1_ht_03_b12.j2k | 12         | 8               | 0           | 0     | 0           | 0    | 0           | 0    | 0           | 0     |
+| ds1_ht_04_b9.j2k  | 9          | 8               | 0           | 0     |             |      |             |      |             |       |
+| ds1_ht_05_b11.j2k | 11         | 8               | 0           | 0     | 0           | 0    | 0           | 0    |             |       |
+| ds1_ht_06_b11.j2k | 11         | 8               | 0           | 0     | 0           | 0    | 0           | 0    |             |       |
+| ds1_ht_07_b11.j2k | 11         | 8               | 0           | 0     | 0           | 0    |             |      |             |       |
+
+Table C.4bis – Additional allowable errors for HTJ2K TCSs belonging to derived set 1
+
+| TCS                                                                                                                                                                                                                                                                                      | $B_{MAGB}$ | Reference depth | Component 0 |     | Component 1 |     | Component 2 |     | Component 3 |     |
+|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------|-----------------|-------------|-----|-------------|-----|-------------|-----|-------------|-----|
+|                                                                                                                                                                                                                                                                                          |            |                 | Peak        | MSE | Peak        | MSE | Peak        | MSE | Peak        | MSE |
+| NOTE – When applied to the tolerances in Table C.6, the additional peak errors are scaled by $2^{D-D_{ref}}$ and rounded up, while the additional MSE values are scaled by $4^{D-D_{ref}}$ , where $D$ is the bit-depth in Table C.6 and $D_{ref}$ is the reference depth in this table. |            |                 |             |     |             |     |             |     |             |     |
+
+#### C.2.2.4 Additional information
+
+Table C.5 describes the key features being tested by the Profile-1 codestreams, while Table C.5bis describes the features being tested by the derived set 0 HTJ2K codestreams. This information is provided solely to help correction of non-compliant decoders when accuracy is not guaranteed.
+
+Table C.5 – Items tested by Profile-1 codestreams
+
+| Codestream # | Tests                                                                                                                                 |
+|--------------|---------------------------------------------------------------------------------------------------------------------------------------|
+| 1            | Image offsets, tile offsets                                                                                                           |
+| 2            | Reset context probabilities, vertically causal contexts, precinct sizes, packed packet headers, tile-part header (PPT) marker segment |
+| 3            | Packed packet headers, main header (PPM) marker segment                                                                               |
+| 4            | QCD marker segment in tile header                                                                                                     |
+| 5            | Odd-sized tile, non-square code-block size, multiple PPM marker segments                                                              |
+| 6            | Small tile size                                                                                                                       |
+| 7            | Small precincts, packet inclusion                                                                                                     |
+
+Table C.5bis – Items tested by derived set 1 HTJ2K codestreams
+
+| Codestream BSET | Tests                                                                                                                                |
+|-----------------|--------------------------------------------------------------------------------------------------------------------------------------|
+| 1               | Image offsets, tile offsets, multiple layers with placeholder passes                                                                 |
+| 2               | Reset context probabilities, vertically causal contexts, precinct sizes, PPT marker segment, multiple layers with placeholder passes |
+| 3               | PPM marker segment, multiple layers with placeholder passes                                                                          |
+| 4               | QCD marker segment in tile header. HTJ2K features: HETEROGENEOUS                                                                     |
+| 5               | Odd-sized tile, non-square code-block size, multiple PPM marker segments, multiple layers with placeholder passes                    |
+| 6               | Small tile size                                                                                                                      |
+| 7               | Small precincts                                                                                                                      |
+
+### C.2.3 Class 1 Profile-0
+
+#### C.2.3.1 Codestreams
+
+The J2K test codestreams for this ETS are in the directory `codestreams_profile0`. There are 16 codestreams, with names of the form `p0_##.j2k`, where `##` is the codestream number. These are the same test codestreams as for Cclass 0 Profile-0, but they shall be decoded to higher quality.
+
+The derived HTJ2K BSETs for this ETS are in the directory `htj2k_bsets_profile0`. There are 16 BSETs, with names of the form `p0_##_bset`, where `##` is the J2K codestream number. Each BSET is a directory, containing codestreams with names of the form `ds0_ht_##_b$.j2k` or `ds0_hm_##_b$.j2k`, where `##` is the J2K codestream number and `$` is the  $B_{MAGB}$  value. Names of the first form are used for HTJ2K codestreams that are HTONLY, in which case the codestream belongs to derived set DS0-HT; otherwise, the second form of the name is used and the codestream belongs to derived set DS0-HM.
+
+#### C.2.3.2 Reference decoded images
+
+The reference decoded images for this ETS are in the directory **reference\_class1\_profile0**. The filenames are of the form **c0p0\_##[rN]-C.pgx**, where **##** is the codestream number, and **N** is the number of inverse wavelet transforms that have been skipped in the decoding of the codestream, and **C** is the component number. A decoder shall produce all components listed, it may produce more.
+
+The same reference decoded images are used when testing both HTJ2K and J2K decoders.
+
+#### C.2.3.3 Tolerances
+
+The maximum allowable MSE and peak errors are listed in Table C.6, along with the size of the reference decoded images.
+
+**Table C.6 – Class 1 Profile-0 reference files and maximum error**
+
+| TCS       | Reference filename | Resolution reduction | Signed | Depth | Width | Height | Peak | MSE   |
+|-----------|--------------------|----------------------|--------|-------|-------|--------|------|-------|
+| p0_01.j2k | c1p0_01-0.pgx      | 0                    | +      | 8     | 128   | 128    | 0    | 0     |
+| p0_02.j2k | c1p0_02-0.pgx      | 0                    | +      | 8     | 64    | 126    | 0    | 0     |
+| p0_03.j2k | c1p0_03-0.pgx      | 0                    | –      | 4     | 256   | 256    | 0    | 0     |
+| p0_04.j2k | c1p0_04-0.pgx      | 0                    | +      | 8     | 640   | 480    | 5    | 0.776 |
+|           | c1p0_04-1.pgx      | 0                    | +      | 8     | 640   | 480    | 4    | 0.626 |
+|           | c1p0_04-2.pgx      | 0                    | +      | 8     | 640   | 480    | 6    | 1.070 |
+| p0_05.j2k | c1p0_05-0.pgx      | 0                    | +      | 8     | 1024  | 1024   | 2    | 0.319 |
+|           | c1p0_05-1.pgx      | 0                    | +      | 8     | 1024  | 1024   | 2    | 0.323 |
+|           | c1p0_05-2.pgx      | 0                    | +      | 8     | 512   | 512    | 2    | 0.317 |
+|           | c1p0_05-3.pgx      | 0                    | +      | 8     | 512   | 512    | 0    | 0     |
+| p0_06.j2k | c1p0_06-0.pgx      | 0                    | +      | 12    | 513   | 129    | 635  | 11287 |
+|           | c1p0_06-1.pgx      | 0                    | +      | 12    | 257   | 129    | 403  | 6124  |
+|           | c1p0_06-2.pgx      | 0                    | +      | 12    | 513   | 65     | 378  | 3968  |
+|           | c1p0_06-3.pgx      | 0                    | +      | 12    | 257   | 65     | 0    | 0     |
+| p0_07.j2k | c1p0_07-0.pgx      | 0                    | –      | 12    | 2048  | 2048   | 0    | 0     |
+|           | c1p0_07-1.pgx      | 0                    | –      | 12    | 2048  | 2048   | 0    | 0     |
+|           | c1p0_07-2.pgx      | 0                    | –      | 12    | 2048  | 2048   | 0    | 0     |
+| p0_08.j2k | c1p0_08-0.pgx      | 1                    | –      | 12    | 257   | 1536   | 0    | 0     |
+|           | c1p0_08-1.pgx      | 1                    | –      | 12    | 257   | 1536   | 0    | 0     |
+|           | c1p0_08-2.pgx      | 1                    | –      | 12    | 257   | 1536   | 0    | 0     |
+| p0_09.j2k | c1p0_09-0.pgx      | 0                    | +      | 8     | 17    | 37     | 0    | 0     |
+| p0_10.j2k | c1p0_10-0.pgx      | 0                    | +      | 8     | 64    | 64     | 0    | 0     |
+|           | c1p0_10-1.pgx      | 0                    | +      | 8     | 64    | 64     | 0    | 0     |
+|           | c1p0_10-2.pgx      | 0                    | +      | 8     | 64    | 64     | 0    | 0     |
+| p0_11.j2k | c1p0_11-0.pgx      | 0                    | +      | 8     | 128   | 1      | 0    | 0     |
+| p0_12.j2k | c1p0_12-0.pgx      | 0                    | +      | 8     | 3     | 5      | 0    | 0     |
+| p0_13.j2k | c1p0_13-0.pgx      | 0                    | +      | 8     | 1     | 1      | 0    | 0     |
+|           | c1p0_13-1.pgx      | 0                    | +      | 8     | 1     | 1      | 0    | 0     |
+|           | c1p0_13-2.pgx      | 0                    | +      | 8     | 1     | 1      | 0    | 0     |
+|           | c1p0_13-3.pgx      | 0                    | +      | 8     | 1     | 1      | 0    | 0     |
+| p0_14.j2k | c1p0_14-0.pgx      | 0                    | +      | 8     | 49    | 149    | 0    | 0     |
+|           | c1p0_14-1.pgx      | 0                    | +      | 8     | 49    | 49     | 0    | 0     |
+|           | c1p0_14-2.pgx      | 0                    | +      | 8     | 49    | 49     | 0    | 0     |
+| p0_15.j2k | c1p0_15-0.pgx      | 0                    | –      | 4     | 256   | 256    | 0    | 0     |
+| p0_16.j2k | c1p0_16-0.pgx      | 0                    | +      | 8     | 128   | 128    | 0    | 0     |
+
+NOTE – See A.1.7 for advice regarding the reconstruction parameter *r* when testing decoder implementations against these error bounds.
+
+These values are used when testing both HTJ2K and J2K decoders. However, when testing an HTJ2K decoder, the allowable MSE and peak errors may be increased, depending on the  $M_{MAGB}$  limit claimed by the IUT, in accordance with the values provided in Table C.1bis.
+
+### C.2.4 Class 1 Profile-1
+
+#### C.2.4.1 Codestreams
+
+The J2K test codestreams for this ETS are in the directory **codestreams\_profile1**. The codestream names have the form **p1\_##.j2k**, where ## is the codestream number. In addition to passing the test for all these codestreams, a decoder shall also pass the Class 1 Profile-0 test to pass the Class 1 Profile-1 test.
+
+The derived HTJ2K BSETs for this ETS are in the directory **htj2k\_bsets\_profile1**. The BSETs in this directory have names of the form **p1\_##\_bset**, where ## is the J2K codestream number. Each BSET is a directory, containing codestreams with names of the form **ds1\_ht\_##\_b\$.j2k** or **ds1\_hm\_##\_b\$.j2k**, where ## is the J2K codestream number and \$ is the  $B_{MAGB}$  value. Names of the first form are used for HTJ2K codestreams that are HTONLY, in which case the codestream belongs to derived set DS1-HT; otherwise, the second form of the name is used and the codestream belongs to derived set DS1-HM.
+
+#### C.2.4.2 Reference decoded images
+
+The reference decoded images for this ETS are in the directory **reference\_class1\_profile1**. The filenames are of the form **clp1\_##[rN]-C.pgx**, where ## is the codestream number, and N is the number of inverse wavelet transforms that have been skipped in the decoding of the codestream, and C is the component number. A decoder shall produce all components listed.
+
+The same reference decoded images are used when testing both HTJ2K and J2K decoders.
+
+#### C.2.4.3 Tolerances
+
+The maximum allowable MSE and peak errors are listed in Table C.7, along with the size of the reference decoded images. These values are used when testing both HTJ2K and J2K decoders. However, when testing an HTJ2K decoder, the allowable MSE and peak errors may be increased, depending on the  $M_{MAGB}$  limit claimed by the IUT, in accordance with the values provided in Table C.4bis.
+
+Table C.7 – Class 1 Profile-1 reference images and allowable error
+
+| TCS       | Reference filename | Resolution reduction | Depth | Width | Height | Peak | MSE    |
+|-----------|--------------------|----------------------|-------|-------|--------|------|--------|
+| p1_01.j2k | clp1_01-0.pgx      | 0                    | 8     | 61    | 99     | 0    | 0      |
+| p1_02.j2k | clp1_02-0.pgx      | 0                    | 8     | 640   | 480    | 5    | 0.765  |
+|           | clp1_02-1.pgx      | 0                    | 8     | 640   | 480    | 4    | 0.616  |
+|           | clp1_02-2.pgx      | 0                    | 8     | 640   | 480    | 6    | 1.051  |
+| p1_03.j2k | clp1_03-0.pgx      | 0                    | 8     | 1024  | 1024   | 2    | 0.311  |
+|           | clp1_03-1.pgx      | 0                    | 8     | 1024  | 1024   | 2    | 0.280  |
+|           | clp1_03-2.pgx      | 0                    | 8     | 512   | 512    | 1    | 0.267  |
+|           | clp1_03-3.pgx      | 0                    | 8     | 512   | 512    | 0    | 0      |
+| p1_04.j2k | clp1_04-0.pgx      | 0                    | 12    | 1024  | 1024   | 624  | 3080   |
+| p1_05.j2k | clp1_05-0.pgx      | 0                    | 8     | 512   | 512    | 40   | 8.458  |
+|           | clp1_05-1.pgx      | 0                    | 8     | 512   | 512    | 40   | 9.716  |
+|           | clp1_05-2.pgx      | 0                    | 8     | 512   | 512    | 40   | 10.154 |
+| p1_06.j2k | clp1_06-0.pgx      | 0                    | 8     | 12    | 12     | 2    | 0.600  |
+|           | clp1_06-1.pgx      | 0                    | 8     | 12    | 12     | 2    | 0.600  |
+|           | clp1_06-2.pgx      | 0                    | 8     | 12    | 12     | 2    | 0.600  |
+| p1_07.j2k | clp1_07-0.pgx      | 0                    | 8     | 2     | 12     | 0    | 0      |
+|           | clp1_07-1.pgx      | 0                    | 8     | 8     | 12     | 0    | 0      |
+
+NOTE – See A.1.7 for advice regarding the reconstruction parameter *r* when testing decoder implementations against these error bounds.
+
+### C.2.5 Class 1HF Profile 1
+
+#### C.2.5.1 Codestreams
+
+The J2K test codestreams for this ETS are in the directory **codestreams\_profile1**. The codestream names have the form **hifi\_p1\_###.j2k**, where '###' is the codestream number.
+
+HTJ2K test codestreams for this ETS are also found in the directory **codestreams\_profile1**, but with codestream names of the form **hifi\_ht1\_##.j2k**, where '##' is the codestream number.
+
+#### C.2.5.2 Reference decoded images
+
+The reference decoded images for this ETS are in the directory **reference\_class1HF\_profile1**. The filenames are of the form **hifi\_##-C.pgx**, where '##' is the codestream number, and 'C' is the component number. A decoder shall produce all components listed.
+
+The same reference decoded images are used when testing both HTJ2K and J2K decoders.
+
+#### C.2.5.3 Tolerances
+
+The maximum allowable MSE and peak errors are listed in Table C.8, along with the size of the reference decoded images. Each TCS whose filename is of the form **hifi\_ht1\_##.j2k** is used for testing HTJ2K decoders, whereas each TCS whose filename is of the form **hifi\_p1\_##.j2k** is used for testing J2K decoders.
+
+Table C.8 – Class 1HF Profile 1 reference images and allowable error
+
+| TCS             | Reference filename | Resolution reduction | Depth | Width | Height | Peak | MSE |
+|-----------------|--------------------|----------------------|-------|-------|--------|------|-----|
+| hifi_p1_02.j2k  | hifi_02-0.pgx      | 0                    | 12    | 128   | 128    | 43   | 80  |
+|                 | hifi_02-1.pgx      | 0                    | 12    | 128   | 128    | 33   | 62  |
+|                 | hifi_02-2.pgx      | 0                    | 12    | 128   | 128    | 38   | 72  |
+| hifi_ht1_02.j2k | hifi_02-0.pgx      | 0                    | 12    | 128   | 128    | 47   | 82  |
+|                 | hifi_02-1.pgx      | 0                    | 12    | 128   | 128    | 36   | 65  |
+|                 | hifi_02-2.pgx      | 0                    | 12    | 128   | 128    | 42   | 86  |
+
+NOTE – See A.1.7 for advice regarding the reconstruction parameter r when testing decoder implementations against these error bounds.
+
+# Annex D
+
+## Encoder compliance test procedure
+
+(This annex does not form an integral part of this Recommendation | International Standard.)
+
+This annex defines testing compliance of an encoder. A J2K encoder may produce any subset of Rec. ITU-T T.800 | ISO/IEC 15444-1, but whatever it does produce shall be a conforming JPEG 2000 codestream. Similarly, an HTJ2K encoder may produce any codestream that conforms to Rec. ITU-T T.814 | ISO/IEC 15444-15.
+
+## D.1 General
+
+It is not a requirement to implement or support all possible encoding modes or capabilities of JPEG 2000. However, many modes and capabilities are desirable for many applications. The ATSSs, as described in Annex C, are used to support the concepts in this subclause. It is impossible to define tests for every encoder variation. Therefore, it is left to the user to define the tests that are appropriate for a given implementation. This subclause gives guidance based on the abstract test procedures, the compliance statement, and the procedures below.
+
+## D.2 Reference decoder
+
+The reference decoder is used for the evaluation of compliance of an encoder. The reference decoder is defined in Rec. ITU-T T.804 | ISO/IEC 15444-5. The reference decoder has been developed by the ISO/IEC JTC 1/SC 29/WG 1 committee for the purpose of guidance for implementers and data providers. The reference decoder should be able to decode all encoder developed codestreams that fall within reasonable limits of encoder applications.
+
+## D.3 Compliance requirement and acceptance
+
+It is not a requirement for an encoder to produce any specific codestream. However, any codestream that is produced shall be a legal JPEG 2000 codestream. A reasonable way that this can be verified is by decoding the codestream with the reference decoder.
+
+This test procedure is adequate for many but not all possible encoder implementations. The reference decoder is limited in some parameters (such as the number of components and component bit-depth) and may not support all possible legal codestreams. On the other hand, the reference decoder may be sufficiently resilient to ignore codestream syntax errors in some cases.
+
+## D.4 Encoding compliance test procedure
+
+Figure D.1 shows the flow for the encoder compliance test. The steps for this compliance test are as follows.
+
+- a) Select a test image that represents the type of imagery that the encoder is designed to compress. The reference decoded images provided for decoder compliance tests are acceptable but not required.
+- b) Encode with the encoder under test.
+- c) Send the codestream to the reference decoder.
+- d) An encoder is found to be compliant if the reference decoder can fully decode the image.
+- e) Repeat steps a) to d) for all parameters for which the encoder is designed. These parameters (tile size, number of decomposition levels, bitrates, etc.) should be varied to the extent to which the encoder will be used.
+- f) Repeat steps a) to e) for several test images, sampling the breadth of imagery types (small image size, large image size, odd image sizes, number of components, components depths, component sampling) the encoder is designed to compress.
+
+If the codestream output by the encoder is embedded within other file formats, it is the responsibility of the tester to strip away any preceding and trailing file information before sending the encoded codestream to the reference decoder.
+
+![Flowchart of the Encoder compliance test procedure. The process starts with I1 (BEGIN) leading to S1 (Select test image). S1 leads to I2 (Test image), which leads to S2 (Encode image). S2 leads to I3 (Compressed codestream), which leads to S4 (Expand image). S4 leads to D3 (Did decoder parse codestream without errors?). If D3 is No, it leads to R1 (Encoder failed compliance). If D3 is Yes, it leads to I4 (Reconstructed image), which leads to D4 (Is reconstructed image acceptable?). If D4 is Yes, it leads to S5 (Encoder passed this compliance test), which leads to D2 (Tested all compression parameters?). If D4 is No, it leads to R1. S5 leads to D2. D2 leads to S3 (Modify compression parameters) if No, which loops back to S2. If D2 is Yes, it leads to D1 (Tested all images?). D1 leads to S1 if No, and to R2 (Encoder passes compliance test procedure) if Yes.](70a863dc6cd47bac82c12162a9479aac_img.jpg)
+
+```
+
+graph TD
+    I1([I1]) --> S1[S1]
+    S1 --> I2([I2])
+    I2 --> S2[S2]
+    S2 --> I3([I3])
+    I3 --> S4[S4]
+    S4 --> D3{D3}
+    D3 -- No --> R1[R1]
+    D3 -- Yes --> I4([I4])
+    I4 --> D4{D4}
+    D4 -- Yes --> S5[S5]
+    D4 -- No --> R1
+    S5 --> D2{D2}
+    D2 -- No --> S3[S3]
+    S3 --> S2
+    D2 -- Yes --> D1{D1}
+    D1 -- No --> S1
+    D1 -- Yes --> R2[R2]
+  
+```
+
+T.803(21)\_FD.1
+
+Flowchart of the Encoder compliance test procedure. The process starts with I1 (BEGIN) leading to S1 (Select test image). S1 leads to I2 (Test image), which leads to S2 (Encode image). S2 leads to I3 (Compressed codestream), which leads to S4 (Expand image). S4 leads to D3 (Did decoder parse codestream without errors?). If D3 is No, it leads to R1 (Encoder failed compliance). If D3 is Yes, it leads to I4 (Reconstructed image), which leads to D4 (Is reconstructed image acceptable?). If D4 is Yes, it leads to S5 (Encoder passed this compliance test), which leads to D2 (Tested all compression parameters?). If D4 is No, it leads to R1. S5 leads to D2. D2 leads to S3 (Modify compression parameters) if No, which loops back to S2. If D2 is Yes, it leads to D1 (Tested all images?). D1 leads to S1 if No, and to R2 (Encoder passes compliance test procedure) if Yes.
+
+I1: BEGIN
+
+I2: Test image
+
+I3: Compressed codestream
+
+I4: Reconstructed image
+
+S1: Select test image
+
+S2: Encode image (encoder under compliance test)
+
+S3: Modify compression parameters
+
+S4: Expand image (reference decoder)
+
+S5: Encoder passed this compliance test
+
+D1: Tested all images?
+
+D2: Tested all compression parameters?
+
+D3: Did decoder parse codestream without errors?
+
+D4: Is reconstructed image acceptable?
+
+R1: Encoder failed compliance
+
+R2: Encoder passes compliance test procedure
+
+**Figure D.1 – Encoder compliance test block diagram**
+
+It is up to the implementer to establish requirements for accepting a reconstructed image. For example, a lossless encoder would be expected to produce a reconstructed image identical to the test image. Requirements for a lossy encoder might include obtaining peak error or MSE values in a specified range or similar evaluation.
+
+# Annex E
+
+## Decoder implementation compliance statement
+
+(This annex does not form an integral part of this Recommendation | International Standard.)
+
+## E.1 General
+
+This annex allows the decoder IUT to describe its capabilities or image quality guarantees. Each system will claim a compliance point (profiles, Cclasses, file format) that will be used to define the compliance test procedures. Once it has defined a profile and Cclass, the IUT will be evaluated with all ETS corresponding up to and including the profile and Cclass being tested. Market applications may demand that a given system comply not only to a profile and Cclass, but also to an increase in one or more parameters (i.e., image size, number of components, bit-depth). Subclause E.3 describes the ability of systems to extend beyond the defined Cclasses for each profile.
+
+## E.2 Decoder implementation compliance statement
+
+The decoder IUT should select the Cclass to which it supports the given profile. The decoder IUT should also select if it supports the relevant JPEG 2000 file format, which is optional. If an IUT claims compliance to a given Cclass, it is required to meet all expectations of that Cclass as defined in Annex A and the ETSs defined in Annex C. Table E.1 shows the ICS for Cclasses, J2K profiles, HTJ2K derived sets and JP2/JPH file formats. A decoder which claims to be compliant with a given J2K profile shall support all J2K profiles that are subsets of the selected profile at the chosen Cclass. For example, if a system claims to be compliant with J2K Profile-1 Cclass 1, then the system shall be tested for J2K Profile-0 Cclass 1 and J2K Profile-1 Cclass 1. Similarly, if a system claims to be compliant with an HTJ2K derived set, then it shall also support all subsets of that derived set. For example, if a system claims to be compliant with DS1-HM Cclass 1h then the system shall be tested for compliance to DS1-HT Cclass 1h, DS0-HM Cclass 1h and DS0-HT Cclass 1h. There is no need to show compliance at Cclass 0 when claiming Cclass 1; similarly, there is no need to show compliance at Cclass 0h when claiming Cclass 1h. However, when ETSs are defined for later Cclasses they may require compliance with Cclass 1 or Cclass 1h. At the time of publication of this Recommendation | International Standard, there is no ETS for Cclass 2 or Cclass 2h. The file format can be supported at any given profile and Cclass. Table E.1 allows an IUT to quickly define level of compliance by marking each empty table entry with either supported or not supported.
+
+Table E.1 – ICS for defined Cclasses, profiles and derived sets
+
+| Cclass               | J2K<br>Profile-0 | J2K<br>Profile-1 | HTJ2K<br>DS0-HT | HTJ2K<br>DS0-HM | HTJ2K<br>DS1-HT | HTJ2K<br>DS1-HM |
+|----------------------|------------------|------------------|-----------------|-----------------|-----------------|-----------------|
+| Cclass 0 / Cclass 0h |                  |                  |                 |                 |                 |                 |
+| Cclass 1 / Cclass 1h |                  |                  |                 |                 |                 |                 |
+| Cclass 2 / Cclass 2h |                  |                  |                 |                 |                 |                 |
+| File Format          | Support          |                  |                 |                 |                 |                 |
+| JP2 file             |                  |                  |                 |                 |                 |                 |
+| JPH file             |                  |                  |                 |                 |                 |                 |
+
+## E.3 Extended support
+
+This Recommendation | International Standard defines parameters for compliance testing for two profiles, each with two derived sets, and three Cclasses, each with a corresponding HTJ2K derived Cclass. It is expected that an IUT will extend beyond the minimal parameters defined by these profiles and Cclasses. Tables E.2 to E.7 allow the IUT to claim capabilities beyond the parameters defined for the Cclasses in Table A.1 and Table A.2. The most common extensions beyond the defined Cclasses are expected to include the ability to decompress a greater image size, a larger number of components, or a higher component depth. The ability to decode a greater image size or larger number of components is directly related to the  $N_{cb}$  and  $L_{body}$  parameters. Therefore, the  $N_{cb}$  and  $L_{body}$  shall be extended to match the claimed image size and components. For example, a system may want to support more components (e.g., three components) than are required for Profile-1 Cclass 0 but does not wish to extend their system to the next Cclass. In this case, the IUT would indicate in Table E.1 that the IUT is Profile-1 Cclass 0 compliant and would include a compliance claim of three components in Table E.2. The increase to three components will change the values in Table E.2 to the following: Components = 3,  $N_{cb}$  = 144, and  $L_{body}$  = 24 576 bytes. All other values would be the same for this implementation compliance statement. It is expected that test codestreams, not defined in this Recommendation | International Standard, may be required to test these capabilities.
+
+Table E.2 – Extended capabilities for Cclass 0
+
+| Parameter             | Cclass 0 minimum                                                             | IUT extensions to Cclass 0 |
+|-----------------------|------------------------------------------------------------------------------|----------------------------|
+| Size ( $W \times H$ ) | $128 \times 128$                                                             |                            |
+| Components            | 1                                                                            |                            |
+| $N_{cb}$              | $(HW/1024 + 32)C = 48$                                                       | $(HW/1024 + 32)C =$        |
+| $N_{comp}$            | 64                                                                           |                            |
+| $L_{body}$            | $1/2(HWC) = 8\ 192$ bytes                                                    | $1/2(HWC) =$               |
+| $M$                   | 11                                                                           |                            |
+| $P$                   | Low enough to allow 5-31 decoding of 9-71 data                               |                            |
+| $B$                   | 8                                                                            |                            |
+| $T_L$                 | 3                                                                            |                            |
+| $L$                   | 15                                                                           |                            |
+| Progressions          | All "basic" progressions in COD, only need decode first progression per tile |                            |
+| Tile Parts            | Decode only first tile-part per tile                                         |                            |
+| Precincts             | Decode first precinct per sub-band                                           |                            |
+
+Table E.3 – Extended capabilities for Cclass 1
+
+| Parameter             | Cclass 1 minimum                                          | IUT extensions to Cclass 1 |
+|-----------------------|-----------------------------------------------------------|----------------------------|
+| Size ( $W \times H$ ) | $2048 \times 2048$                                        |                            |
+| Components            | 4                                                         |                            |
+| $N_{cb}$              | $(HW/256 + 128)C = 66\ 048$                               | $(HW/256 + 128)C =$        |
+| $N_{comp}$            | 256                                                       |                            |
+| $L_{body}$            | $HWC/2 = 2^{23}$ bytes                                    | $HWC/2 =$                  |
+| $M$                   | 15                                                        |                            |
+| $P$                   | 16-bit fixed point implementation                         |                            |
+| $B$                   | 12                                                        |                            |
+| $T_L$                 | 6                                                         |                            |
+| $L$                   | 255                                                       |                            |
+| Progressions          | Limited only by number of levels, layers and components   |                            |
+| Tile Parts            | Decode all tile-parts up to $N_{cb}$ or $L_{body}$ limits |                            |
+| Precincts             | Decode all precincts up to $N_{cb}$ or $L_{body}$ limits  |                            |
+
+Table E.4 – Extended capabilities for Cclass 2
+
+| Parameter             | Cclass 2 minimum                     | IUT extensions to Cclass 2 |
+|-----------------------|--------------------------------------|----------------------------|
+| Size ( $W \times H$ ) | $16384 \times 16384$                 |                            |
+| Components            | 256                                  |                            |
+| $N_{cb}$              | $(HW/256 + 128)C = 268\ 468\ 224$    | $(HW/256 + 128)C =$        |
+| $N_{comp}$            | 16 384                               |                            |
+| $L_{body}$            | $HWC/64 = 2^{30}$                    | $HWC/64 =$                 |
+| $M$                   | 30                                   |                            |
+| $P$                   | 32-bit floating point implementation |                            |
+| $B$                   | 16                                   |                            |
+| $T_L$                 | 12                                   |                            |
+| $L$                   | 65 535                               |                            |
+
+Table E.4 – Extended capabilities for Cclass 2
+
+| Parameter    | Cclass 2 minimum                                          | IUT extensions to Cclass 2 |
+|--------------|-----------------------------------------------------------|----------------------------|
+| Progressions | Limited only by number of levels, layers and components   |                            |
+| Tile Parts   | Decode all tile-parts up to $N_{cb}$ or $L_{body}$ limits |                            |
+| Precincts    | Decode all precincts up to $N_{cb}$ or $L_{body}$ limits  |                            |
+
+Table E.5 – Extended capabilities for derived Cclass 0h
+
+| Parameter                                         | Cclass 0 minimum | IUT extensions to Cclass 0 |
+|---------------------------------------------------|------------------|----------------------------|
+| Size ( $W \times H$ ), Components, ..., Precincts | As in Table E.2  | As in Table E.2            |
+| $M_{MAGB}$                                        | 11               |                            |
+
+Table E.6 – Extended capabilities for derived Cclass 1h
+
+| Parameter                                         | Cclass 0 minimum | IUT extensions to Cclass 0 |
+|---------------------------------------------------|------------------|----------------------------|
+| Size ( $W \times H$ ), Components, ..., Precincts | As in Table E.3  | As in Table E.3            |
+| $M_{MAGB}$                                        | 15               |                            |
+
+Table E.7 – Extended capabilities for derived Cclass 2h
+
+| Parameter                                         | Cclass 0 minimum | IUT extensions to Cclass 0 |
+|---------------------------------------------------|------------------|----------------------------|
+| Size ( $W \times H$ ), Components, ..., Precincts | As in Table E.2  | As in Table E.4            |
+| $M_{MAGB}$                                        | 30               |                            |
+
+# Annex F
+
+## Encoder implementation compliance statement
+
+(This annex does not form an integral part of this Recommendation | International Standard.)
+
+## F.1 General
+
+The only requirement for encoder compliance is to produce compliant codestreams; any other requirements using quality criteria (such as PSNR or MSE) are not part of this Recommendation | International Standard. There are an unlimited number of possible compliant codestreams. Defining tests for all possible compliant codestream variations is not possible. The compliance testing of an encoder IUT is supported by the ICS described in this annex, which helps define the compliance testing procedures and parameters in Annex D.
+
+Table F.1 – Encoder implementation marker usage
+
+| Marker              | Marker value | Image header   | Tile header | Bitstream | IUT usage |
+|---------------------|--------------|----------------|-------------|-----------|-----------|
+| SOC                 | 0xFF4F       | Required       |             |           |           |
+| CAP                 | 0xFF50       | HTJ2K Required |             |           |           |
+| Profile (PRF)       | 0xFF56       |                |             |           |           |
+| CPF                 | 0xFF59       | HTJ2K Only     |             |           |           |
+| SOT                 | 0xFF90       |                | Required    |           |           |
+| Start of data (SOD) | 0xFF93       |                | Required    |           |           |
+| EOC                 | 0xFFD9       |                |             | Required  |           |
+| SIZ                 | 0xFF51       | Required       |             |           |           |
+| COD                 | 0xFF52       | Required       |             |           |           |
+| COC                 | 0xFF53       |                |             |           |           |
+| RGN                 | 0xFF5E       |                |             |           |           |
+| QCD                 | 0xFF5C       | Required       |             |           |           |
+| QCC                 | 0xFF5D       |                |             |           |           |
+| POC                 | 0xFF5F       |                |             |           |           |
+| TLM                 | 0xFF55       |                |             |           |           |
+| PLM                 | 0xFF57       |                |             |           |           |
+| PLT                 | 0xFF58       |                |             |           |           |
+| PPM                 | 0xFF60       |                |             |           |           |
+| PPT                 | 0xFF61       |                |             |           |           |
+| SOP                 | 0xFF91       |                |             |           |           |
+| EPH                 | 0xFF92       |                |             |           |           |
+| CRG                 | 0xFF63       |                |             |           |           |
+| COM                 | 0xFF64       |                |             |           |           |
+
+## F.2 Encoder description
+
+Table F.1 describes required and optional markers that are used by an encoder. Each of the markers is defined as required or optional in each section of an encoded codestream (image header, tile header, bitstream). In Table F.1, white blocks labelled "required" are defined as required markers in that section of the encoded bitstream. The grey cells are optional and the black cells are not allowed. It is possible that an encoder may not support all optional markers, but it shall adhere to all required markers and marker segments. Table F.1 allows the tester to identify what markers are possible and the IUT usage of each marker. For example, an IUT may use the COC marker, but only allow it to be used twice in a given codestream. Two marker segments play a role that is specific to HTJ2K codestreams: CAP is required in an HTJ2K codestream, while CPF is optional in an HTJ2K codestream. Table F.1 allows the tester to identify which markers are possible and the IUT usage of each marker. For example, an IUT may use the COC marker, but only allow it to be used twice in a given codestream.
+
+It may be possible that an encoder is fully compliant, but only allows user control over a selected set of encoder parameters. In this case, the IUT may only want to test those cases. For example, an encoder may support both tiles and precincts, but may force the user to use tiles of a given size because of consideration for the Cclass of the decoder system. Each of these markers and marker segments define parameters and capabilities of the encoder IUT.
+
+Compliance testing parameters and ranges may be defined by the ICS. For example, an ICS may define  $X_{\text{SIZ}}$  and  $Y_{\text{SIZ}}$  to be limited to only power of two square images that are between the size of  $256 \times 256$  and  $2048 \times 2048$ . Therefore, in the compliance testing, all square power of two image sizes within the bounds (e.g.,  $256 \times 256$ ,  $512 \times 512$ ,  $1024 \times 1024$ , and  $2048 \times 2048$ ) should be tested. Values outside these should not be tested since the encoder does not claim to be compliant outside these values. Two marker segments play a role that is specific to HTJ2K codestreams: CAP is required in an HTJ2K codestream, while CPF is optional in an HTJ2K codestream. Table F.1 allows the tester to identify which markers are possible and the IUT usage of each marker. For example, an IUT may use the COC marker, but only allow it to be used twice in a given codestream.
+
+# Annex G
+
+## JP2 and JPH file format reader compliance testing procedures
+
+(This annex does not form an integral part of this Recommendation | International Standard.)
+
+## G.1 General
+
+Every compliant JP2 file format reader shall be able to fully decode or partially decode the codestream contained within the file within the terms as defined in Annexes B and C. In addition, the reader shall also be able to properly interpret the colourspace of the decoded image data as specified within the file format. Minimal compliance for the interpretation of colourspace is defined as the possible upsampling of the decoded image data such that all decoded components are at the same resolution, and the transformation of the decoded image data to the standard red–green–blue (sRGB) colourspace for display on a typical computer monitor. While it is well understood that many applications will not convert images directly to the sRGB colourspace, the use of sRGB as a comparison point provides a simple and accurate way to compare output of an application under test with reference output.
+
+While this compliance test is optional with respect to all implementations of the JPEG 2000 standard (as implementation of the JP2 file format is optional for compliant decoders), it is required and normative for all applications that claim compliance with the JP2 file format as defined in Rec. ITU-T T.800 | ISO/IEC 15444-1.
+
+This normative compliance test includes the required test files. The compliance test is separated into two parts: first, decoding of the codestream contained within the JP2 file; and second, the interpretation of the colourspace of the decoded image data.
+
+A compliant JPH file format reader shall be able to extract the embedded HTJ2K codestream and pass the associated compliance tests for decoding the codestream, as defined in Annexes B and C. It shall also be able to parse all defined boxes in the file that form part of the JPH file format specification, as detailed in Rec. ITU-T T.814 | ISO/IEC 15444-15, ignoring any additional boxes in the file that are not understood by the reader. A compliant JPH file format reader is not required to interpret colourspace information or perform colourspace conversions, although this may be a requirement for specific applications.
+
+## G.2 JP2 file compliance requirement and acceptance
+
+A compliant file format reader shall first pass the compliance tests for decoding as defined in Annexes B and C. It shall also be able to properly interpret the colourspace of each test file. Unlike the compliance tests defined in Annexes B and C, this test does not differentiate between full and partial decode of the image. Any JP2 file format reader that can properly extract the codestream from a JP2 file and decode the codestream to sufficiently pass the tests in Annexes B and C passes the first part of the file format compliance test.
+
+For the purposes of this test, all test images shall be fully decoded in order to minimize the number of reference images that have to be tested against. It is assumed that if a file format reader passes the tests in Annexes B and C, then it is capable of properly decoding any codestream contained within a JP2 file.
+
+## G.3 Reading a JP2 file compliance test procedure
+
+Figure G.1 shows the flow of the decoder compliance test. A decoder is found to be compliant if the resulting test data, for the tests specified for a particular process, match, within the defined tolerances, to the reference test image.
+
+- a) Each test file is decoded using the decoder under test.
+- b) If the decoded components are not all at the same resolution, all components should be upsampled to the same resolution. While in general applications are not required to upsample the decoded data, and the particular method of interpolation is outside of the scope of this Recommendation | International Standard, this test requires the interpolation of the data in order to bring all images for comparison to a single state.
+- c) Convert the decoded image data from the source colourspace (as indicated in the Colour Specification boxes within the JP2 file) to the sRGB colourspace. For readers that do not display images (i.e., printers), it is acceptable to convert the images to the desired output colourspace of the device. In this case, the reference output images shall also be converted to the same output colourspace for comparison.
+- d) Compare the reconstructed image (converted image) to the reference sRGB output for that test file by computing the maximum difference between the two images.
+- e) The peak error is compared with the bound for the test image.
+
+Failure to meet the tolerance limits for a single image results in the decoder failing to be compliant for the file format test.
+
+![Flowchart for JP2 file format reader compliance test block diagram. The process starts with S1 (Select first test file), followed by S2 (Decode TCS with IUT), S3 (Convert to full resolution sRGB), and S4 (Compare with reference image). A decision diamond D1 (Any error metrics within tolerance?) follows. If 'No', it leads to R1 (Decoder failed compliance). If 'Yes', it leads to decision diamond D2 (More tests?). If 'No' from D2, it leads to R2 (Decoder passed compliance). If 'Yes' from D2, it leads to S5 (Select next test file), which loops back to S2. The diagram is labeled T.803(21)_FG.1.](b9c0d46c1148cf65cb79f27fac420981_img.jpg)
+
+```
+
+graph TD
+    S1([S1]) --> S2([S2])
+    S2 --> S3([S3])
+    S3 --> S4([S4])
+    S4 --> D1{D1}
+    D1 -- No --> R1[R1]
+    D1 -- Yes --> D2{D2}
+    D2 -- No --> R2[R2]
+    D2 -- Yes --> S5([S5])
+    S5 --> S2
+  
+```
+
+T.803(21)\_FG.1
+
+Flowchart for JP2 file format reader compliance test block diagram. The process starts with S1 (Select first test file), followed by S2 (Decode TCS with IUT), S3 (Convert to full resolution sRGB), and S4 (Compare with reference image). A decision diamond D1 (Any error metrics within tolerance?) follows. If 'No', it leads to R1 (Decoder failed compliance). If 'Yes', it leads to decision diamond D2 (More tests?). If 'No' from D2, it leads to R2 (Decoder passed compliance). If 'Yes' from D2, it leads to S5 (Select next test file), which loops back to S2. The diagram is labeled T.803(21)\_FG.1.
+
+S1: Select first test file
+
+S2: Decode TCS with IUT
+
+S3: Convert to full resolution sRGB
+
+S4: Compare with reference image
+
+S5: Select next test file
+
+D1: Any error metrics within tolerance?
+
+D2: More tests?
+
+R1: Decoder failed compliance
+
+R2: Decoder passed compliance
+
+Figure G.1 – JP2 file format reader compliance test block diagram
+
+## G.4 JP2 file format test codestreams and images
+
+### G.4.1 Test files
+
+The test files for this ETS are in the directory **testfiles\_jp2**. The codestream names have the form **file#.jp2**, where # is the codestream number.
+
+### G.4.2 Reference decoded images
+
+The reference decoded images for this ETS are in the directory **reference\_jp2**. The filenames are of the form **jp2\_#.tif**, where # is the file number. A decoder shall produce all components listed. All codestreams within the files are decoded at full resolution.
+
+### G.4.3 Tolerances
+
+The maximum allowable peak errors are listed in Table G.1, along with the size of the reference decoded images.
+
+Table G.1 – JP2 reference images and allowable error
+
+| Test file | Reference filename | Components | Depth | Width | Height | Peak |
+|-----------|--------------------|------------|-------|-------|--------|------|
+| file1.jp2 | jp2_1.tif          | 3          | 8     | 768   | 512    | 4    |
+| file2.jp2 | jp2_2.tif          | 3          | 8     | 480   | 640    | 4    |
+| file3.jp2 | jp2_3.tif          | 3          | 8     | 480   | 640    | 4    |
+| file4.jp2 | jp2_4.tif          | 1          | 8     | 768   | 512    | 4    |
+| file5.jp2 | jp2_5.tif          | 3          | 8     | 768   | 512    | 4    |
+| file6.jp2 | jp2_6.tif          | 1          | 12    | 768   | 512    | 4    |
+| file7.jp2 | jp2_7.tif          | 3          | 16    | 480   | 640    | 4    |
+| file8.jp2 | jp2_8.tif          | 1          | 8     | 700   | 400    | 4    |
+| file9.jp2 | jp2_9.tif          | 1          | 8     | 768   | 512    | 4    |
+
+### G.4.4 Additional information regarding the JP2 test files
+
+file1.jp2 and other test files contain the value 0x00000001 in the Compatibility List of the File Type box. This value does not correspond to any specified decoder or profile and is reserved for other ITU-T | ISO uses. Its inclusion in the test files is to ensure that decoders can decode files that contain items from the Compatibility List that are unknown to the decoder.
+
+This information is provided solely to help correction of non-compliant decoders and is not guaranteed. All the test files conform to Profile-0. In addition:
+
+- **file1.jp2:** Three 8-bit components in the sRGB colourspace. The components are in the standard order and are transformed using the RCT. This file also includes XML metadata. If a reader fails on this file, the likely cause is a problem with parsing of the boxes.
+- **file2.jp2:** Three 8-bit components in the sRGB-YCC colourspace. All components are at the full resolution, but are stored in reverse order in the codestream. The JP2 file contains a Channel Definition box that correctly associates each physical component with the correct colour in the sRGB-YCC definition. If a reader fails on this file, the likely causes are an incorrect interpretation of the Channel Definition box or an error in the conversion from sRGB-YCC to sRGB.
+- **file3.jp2:** Three 8-bit components in the sRGB-YCC colourspace, with the Cb and Cr components being subsampled 2x in both the horizontal and vertical directions. The components are stored in the standard order. If a reader fails on this file, the likely causes are an error in either resampling or in conversion from sRGB-YCC to sRGB.
+- **file4.jp2:** One 8-bit component in the sRGB-grey colourspace. If a reader fails on this file, the likely cause is an error in parsing of the boxes.
+- **file5.jp2:** Three 8-bit components in the ROMM-RGB colourspace, encapsulated in a JP2 compatible JPX file. The components have been transformed using the RCT. The colourspace is specified using both a Restricted International Colour Consortium (ICC) profile and using the JPX-defined enumerated code for the ROMM-RGB colourspace. If a decoder fails on this file, the likely cause is an incorrect implementation of the Restricted ICC Three-Component transformation.
+- **file6.jp2:** One 12-bit component in the sRGB-grey colourspace. If a reader fails on this file, the likely cause is an error in the extraction of 8 bits from the 12-bit codestream.
+- **file7.jp2:** Three 16-bit components in the e-sRGB colourspace, encapsulated in a JP2 compatible JPX file. The components have been transformed using the RCT. The colourspace is specified using both a Restricted ICC profile and using the JPX-defined enumerated code for the e-sRGB colourspace. If a reader fails on this file, the likely causes are an error in conversion from the 16-bit data to 8-bit, or an error in implementation of Restricted ICC support.
+- **file8.jp2:** One 8-bit component in a gamma 1.8 space. The colourspace is specified using a Restricted ICC profile. If a reader fails on this file, the likely cause is the implementation of the Monochrome Input profile as part of Restricted ICC.
+
+- **file9.jp2**: One 8-bit component, which is used as input to a 256-entry palette that maps the single component to three 8-bit components. The depalettized components are in the sRGB colourspace. If a reader fails on this test, the likely cause is the application of the palette to the single component.
+
+## G.5 JPH file format test codestreams and images
+
+### G.5.1 Test files
+
+The test files for this ETS are in the directory **testfiles\_jph**. The codestream names have the form **file#\_b\$.jph**, where # is the codestream number and '\$' is the  $B_{MAGB}$  value of the embedded HTJ2K codestream, and the '+++' suffix identifies specific features of the wrapping. As with the test codestreams in Annex C, HTJ2K encodings with multiple values of the  $B_{MAGB}$  parameter may be provided to facilitate the testing of implementations that comply with Cclass 0h, but not Cclass 1h. Where lossless representation of the source content requires a  $B_{MAGB}$  value larger than 15, three HTJ2K encodings are provided, including encodings at  $B_{MAGB}$  values of 11 and 15, so as to facilitate the testing also of implementations that comply with Cclass 1h, but not Cclass 2h.
+
+### G.5.2 Relationship between the JP2 and JPH test files
+
+The first nine JPH files have been obtained by reversibly transcoding JP2 files, as described in Table G.1. The codestream number # for each of these JPH files corresponds to the codestream number of the J2K codestream embedded in the corresponding JP2 file. The properties of these nine JPH files are identical to those of the corresponding JP2 files, as documented in G.4.4.
+
+Additional JPH files are provided to test specific features of the JPH file format. The reference decoded image data for these files is found within the directory **reference\_jph**, with filenames of the form **jph\_#\_+.tif**, where # is the file number and '+' is the codestream component. The codestreams embedded in these files are also obtained by transcoding losslessly compressed Profile-0 codestreams to HTJ2K codestreams and embedding them within the JPH file format. The specific features of interest in these files are as follows:
+
+- **file10.jph**: Five 8-bit components, transformed and encoded reversibly without the RCT without any COLR box, using application-defined (CDEF typ=3) colour channel descriptions for the first four components and a global opacity channel (CDEF typ=1, asoc=0) for the fifth component. The 16-bit application-defined asoc values for the first four components are ASCII 2-character codes "G1", "R1", "B1", "G1" and the underlying components are assigned codestream registration offsets that are intended to reflect the locations of raw digital camera sensor samples with a Bayer Colour Filter Array (CFA). Readers may fail on this file if they are unable to process application-defined colour channels or they are expecting to find a COLR box within the JP2 header box.
+
+# Annex H
+
+## Test codestreams and files conforming to Rec. ITU-T T.801 | ISO/IEC 15444-2
+
+(This annex does not form an integral part of this Recommendation | International Standard.)
+
+## H.1 General
+
+This annex describes a collection of additional test materials that are provided as an electronic attachment to facilitate the implementation of various features from Rec. ITU-T T.801 | ISO/IEC 15444-2 [1], which defines many extensions of the core coding technology in Rec. ITU-T T.800 | ISO/IEC 15444-1 that can also be used to extend the HT coding technology in Rec. ITU-T T.814 | ISO/IEC 15444-15.
+
+These additional test materials are by no means exhaustive and do not cover all of the extensions defined in Rec. ITU-T T.801 | ISO/IEC 15444-2. Moreover, these additional test materials are provided as-is, without specific compliance testing procedures or error bounds. One reason for this is that these extended coding tools are not covered by any of the JPEG 2000 profiles defined at the time when this annex was prepared.
+
+At the codestream level, the two extended coding tools for which additional test materials are provided are:
+
+- 1. Multiple component transformation, which allow reversible and irreversible matrix and wavelet transformations to be flexibly introduced in a sequence of transformation stages that progressively map the image planes recovered by inverse spatial wavelet transformation to a set of output image components.
+- 2. Non-linear transformation, which can be applied to the individual sample values recovered by inverse multiple component transformation or, in the absence of multiple component transformation, to the individual sample values recovered by inverse spatial wavelet transformation.
+
+At the image file level, there are two features of the JPX file format defined in Rec. ITU-T T.801 | ISO/IEC 15444-2, for which additional test materials are provided:
+
+- 1. Files containing multiple codestreams, with multiple compositing layers that describe different images.
+- 2. Files containing Fragment List boxes that allow codestream content and descriptive metadata to be located elsewhere, within or even outside the main file, through the use of Fragment Table and Cross-Reference boxes.
+
+## H.2 Extended test codestreams
+
+The J2K test codestreams for this ETS are in the directory **codestreams\_extended**. There are 4 codestreams in the directory, whose names and properties are summarized in Table H.1. A detailed report on the contents of each codestream may be found in the **descriptions\_extended** directory, and reference image components, with which the decoded output can be compared, are found within the **reference\_extended** directory.
+
+Table H.1 – Properties of each extended codestream
+
+| Test file | Reference filename | Properties                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
+|-----------|--------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| mct1.j2k  | mct1-0.pgx         | Single stage multiple component transformation, involving 5 levels of irreversible 9/7 DWT applied across all 60 image components; after the inverse multiple component wavelet transformation, decoders add the offsets found in the 60 element array that is part of the MCT marker segment; here, these offsets are all equal to 128. Output components are all 8-bit unsigned, while intermediate components are identified as having 10-bit signed values, except for the low-pass sub-band at the base of the multiple component wavelet transformation, which are identified as having a 9-bit signed representation, but note that these intermediate components are not integers, but inverse spatial wavelet transformation operations reconstruct the intermediate components as if they had the declared bit-depths, without rounding to integers. |
+|           | ...                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
+|           | mct1-59.pgx        |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
+| mct2.j2k  | mct2-0.pgx         |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
+|           | ...                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
+
+Table H.1 – Properties of each extended codestream
+
+| Test file | Reference filename | Properties                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
+|-----------|--------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+|           | mct2-179.pgx       | Two stage multiple component transformation, involving one stage with 5 levels of irreversible 9/7 DWT and a second stage with 3x3 matrix transformations. Each stage of the transform involves blocks of components, where each block is processed identically within the stage. After inverse spatial wavelet transformation, the 180 components recovered are partitioned into blocks of 60 components each, where the first block consists of components 0, 3, 6, ..., the second block consists of components 1, 4, 7, ... and the third block consists of components 2, 5, 8, .... Inverse multiple component wavelet transformation is applied to each of the three blocks, producing a new set of 180 components that are interleaved in the same order as those that were input to the inverse multiple component transformation. In the second stage, the components are partitioned into consecutive blocks of 3 components each, and each such block is subjected to a 3x3 matrix transformation that mimics the behaviour of the inverse multi-component decorrelating transform of Rec. ITU-T T.800   ISO/IEC 15444-1. From a forward, compression point of view, the process associated with this two stage transform can be understood as having first performed the 3x3 multi-component decorrelating transform (an RGB to YCbCr transform) to each successive block of 3 components and then applied the multiple component wavelet transform to the 60 Y components, the 60 Cb components and the 60 Cr components. |
+| mct3o.j2k | mct3o-0.pgx        | Single stage multiple component transformation, involving a 3x2 matrix operation, such that there are only 2 components recovered by inverse spatial wavelet transformation, but these 2 components are subjected to the matrix transformation to produce 3 output image components.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
+|           | mct3o-1.pgx        |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
+|           | mct3o-2.pgx        |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
+| nlt1.j2k  | nlt1-0.pgx         | The decoder processes each sample of each component produced by inverse spatial wavelet transformation with a non-linear transform of "gamma" type.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
+|           | nlt1-1.pgx         |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
+|           | nlt1-2.pgx         |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
+
+## H.3 JPX test files
+
+The additional test files are found in the directory **testfiles\_jpx**. There are 2 test files in the directory, whose names and properties are summarized in Table H.2. A detailed report on the contents of each file may be found in the **descriptions\_jpx** directory, and the reference image components, with which the decoded output components may be compared, are found within the **reference\_jpx** directory.
+
+Table H.2 – Properties of each JPX test file
+
+| Test file     | Reference filename | Properties                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
+|---------------|--------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| multi_img.jpx | multi-img-0.tif    | JPX file with two contiguous codestream boxes, two codestream header boxes and two compositing layer header boxes, representing two separate RGB images.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
+|               | multi-img-1.tif    |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
+| float.jpx     | float.tif          | JPX file containing one codestream, whose three 16-bit colour output image components are derived by inverse spatial wavelet transformation, followed by the irreversible component decorrelating transform defined in Rec. ITU-T T.800   ISO/IEC 15444-1, followed by a non-linear transform that converts 16-bit integers to sign-magnitude form. The file's JP2 header box contains a pixel format box that provides an interpretation of the 16-bit sign-magnitude sample values from the codestream as 16-bit half-float sample values of an RGB image.                                                                                                                                                                                                                                                                                  |
+| reboxing.jpx  | reboxing.tif       | JPX file with two codestreams, two codestream header boxes and two compositing layer header boxes. The codestreams are represented by fragment table boxes, rather than contiguous codestream boxes, where the fragments of each codestream are located within media data (mdat) boxes. The second codestream header box contains a cross-reference box that provides the image header sub-box indirectly as the composition of two file fragments that are found within media data boxes. The second compositing layer header box contains a colour group box (cgrp) that itself contains a cross-reference box that provides the embedded colour box indirectly as a file fragment. The second compositing layer header box also contains another cross-reference box that provides a channel definition box indirectly as a file fragment. |
+
+# Bibliography
+
+- [1] Recommendation ITU-T T.801 | ISO/IEC 15444-2, *Information technology – JPEG 2000 image coding system: Extensions*.
+
+
+
+
+
+# SERIES OF ITU-T RECOMMENDATIONS
+
+|                 |                                                                                                                                                           |
+|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Series A        | Organization of the work of ITU-T                                                                                                                         |
+| Series D        | Tariff and accounting principles and international telecommunication/ICT economic and policy issues                                                       |
+| Series E        | Overall network operation, telephone service, service operation and human factors                                                                         |
+| Series F        | Non-telephone telecommunication services                                                                                                                  |
+| Series G        | Transmission systems and media, digital systems and networks                                                                                              |
+| Series H        | Audiovisual and multimedia systems                                                                                                                        |
+| Series I        | Integrated services digital network                                                                                                                       |
+| Series J        | Cable networks and transmission of television, sound programme and other multimedia signals                                                               |
+| Series K        | Protection against interference                                                                                                                           |
+| Series L        | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant |
+| Series M        | Telecommunication management, including TMN and network maintenance                                                                                       |
+| Series N        | Maintenance: international sound programme and television transmission circuits                                                                           |
+| Series O        | Specifications of measuring equipment                                                                                                                     |
+| Series P        | Telephone transmission quality, telephone installations, local line networks                                                                              |
+| Series Q        | Switching and signalling, and associated measurements and tests                                                                                           |
+| Series R        | Telegraph transmission                                                                                                                                    |
+| Series S        | Telegraph services terminal equipment                                                                                                                     |
+| <b>Series T</b> | <b>Terminals for telematic services</b>                                                                                                                   |
+| Series U        | Telegraph switching                                                                                                                                       |
+| Series V        | Data communication over the telephone network                                                                                                             |
+| Series X        | Data networks, open system communications and security                                                                                                    |
+| Series Y        | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities                               |
+| Series Z        | Languages and general software aspects for telecommunication systems                                                                                      |
\ No newline at end of file
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/01e00200a536673d6cd0e6d8705047a0_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/01e00200a536673d6cd0e6d8705047a0_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..a3c84505682a0653f201547622f56cd7adfed3b3
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/01e00200a536673d6cd0e6d8705047a0_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:5db5c7368f4960f054f060aa387d5aac1099b69a76024576f74c33e2b208154d
+size 13851
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/06291c5328a7a4335d41a48850a3a207_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/06291c5328a7a4335d41a48850a3a207_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..4408a5507af2d033b6f0c2d406159c7ff26d3504
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/06291c5328a7a4335d41a48850a3a207_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:82519e42a076270a18fffca93a2a6c395d8af53f91c18794063c5e59ced7516f
+size 43867
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/0b998e3ad8f9d104768642612605cb35_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/0b998e3ad8f9d104768642612605cb35_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..7e8d314a8baaa309dd1dfd981dbb9c2ffd0d22b8
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/0b998e3ad8f9d104768642612605cb35_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:40e580f7f50bd5fb2d1bc5aa014b43b0a1a84b5fb6dae565251cae7c1e23e1ff
+size 55288
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/0dfdff10c725fe9c332b07ade9d23a5e_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/0dfdff10c725fe9c332b07ade9d23a5e_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..c075caee3d152e01122020112eae65f726bbc999
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/0dfdff10c725fe9c332b07ade9d23a5e_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:63ec39b8cb9adede9ca166a77e7eda053a7c78a889c2d5802aa2334cf27b30b2
+size 29088
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/0e252770f8f0573617e0112b36a93d2f_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/0e252770f8f0573617e0112b36a93d2f_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..d6ac40ded6a8d23b7feb4f5067d27fb8a096e737
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/0e252770f8f0573617e0112b36a93d2f_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:04699a900420cf817e6178ea6bd821f125fb13c2a4d02ede2cfdd0dabc6b9b08
+size 119194
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/1142ba0197b158bb198186fe8baccc32_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/1142ba0197b158bb198186fe8baccc32_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..543dab12f078af3946c44190fa7645160a753d5f
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/1142ba0197b158bb198186fe8baccc32_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:eab7498718133260a2c755fa0de406ca67361ce9b9bc7307b12bfe109aae91a6
+size 41048
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/11f18bf0233d812ad2604f88f3385d60_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/11f18bf0233d812ad2604f88f3385d60_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..b903923f25a1f355b90763d7ec2f6ddb29298e66
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/11f18bf0233d812ad2604f88f3385d60_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:b27d0806c7f42f45fcafd51e43910c68566527dfb393b63580712c72ad3bec32
+size 162886
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/145fb9b19dc6513e7bf84c9ba7f083f2_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/145fb9b19dc6513e7bf84c9ba7f083f2_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..b5c785ae3e76316352c75e637757a38299cb3eca
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/145fb9b19dc6513e7bf84c9ba7f083f2_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:cf672cc2d4a31ae294c2d5068a9201e5c721c16e9dd01e522f750a39047abcbc
+size 176005
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/18d7d8de298d79e7bc87af5217f11203_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/18d7d8de298d79e7bc87af5217f11203_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..ecc460a143cf9c908b9794c7bbba86488d8ffdb5
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/18d7d8de298d79e7bc87af5217f11203_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:23effe341446285a5ef32ea3c57aaed800ec0aa5f30f8245deabf8f6eae78e89
+size 53008
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/19a5f0db57a21a0e82a7f326083e96fd_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/19a5f0db57a21a0e82a7f326083e96fd_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..89084741006eab4ae002981b041fe0096ee96452
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/19a5f0db57a21a0e82a7f326083e96fd_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:3cba811a32e8f7dc5c9b81e6d28b06914f68c77bc1702cf68aa920ea671bed5c
+size 37259
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/27f9c45d41672d72c3cc3c2ea386ebbb_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/27f9c45d41672d72c3cc3c2ea386ebbb_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..e175f27fd0c4efb4756489c11d3b742f603b0d05
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/27f9c45d41672d72c3cc3c2ea386ebbb_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:5b3896488ce6e3ba7ff3233617f788fc1909f4cfa6a652f0f0b7b3f640490225
+size 63320
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/29f586959675cafdf81cf934954908eb_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/29f586959675cafdf81cf934954908eb_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..70b1fbfbf18d42b905295e0378e50118c2344521
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/29f586959675cafdf81cf934954908eb_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:c9f84820546485c601e61748deee3d4d35dc5e6b962b6aab07eccc53cfda7048
+size 15764
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/29fbbed4c4aff19e9ac5bf98e0c9b24d_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/29fbbed4c4aff19e9ac5bf98e0c9b24d_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..1bb7c6be9c1cc8d795a1d134b89acc3c923b2b1a
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/29fbbed4c4aff19e9ac5bf98e0c9b24d_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:f056fca7dadcb5dcfc1f9e2df2ce999af5d6d4e53623f99372703a92841c1c16
+size 120718
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/2bacc162a73d75c43a7f90715832bd13_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/2bacc162a73d75c43a7f90715832bd13_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..c6ac4a6f30a423855895fd04ee8625c6161bfdf1
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/2bacc162a73d75c43a7f90715832bd13_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:bc9f554ad4704644c7da12f2f782045e057c8b29741cb1e62334b5a6d0c89db5
+size 38931
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/2d4807f80a3f0106f1722d5722cfac87_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/2d4807f80a3f0106f1722d5722cfac87_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..d4d8969f805414689ab79cfd08c333d454d482b3
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/2d4807f80a3f0106f1722d5722cfac87_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:636c3839edff955a5b6208530b05fa1c983ab153d90f00216517a7a99478b988
+size 7074
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/2d548db0b26b7bf33244320322d5ee2c_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/2d548db0b26b7bf33244320322d5ee2c_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..77b3d500d783165ef335e0c7f495b651f6345272
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/2d548db0b26b7bf33244320322d5ee2c_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:2867704576105c69daa17cca0ef91127f8fb58b25bb8211f3918b52c04771e1a
+size 30819
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/318886a86a1dcc59e1fc83db6f157c60_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/318886a86a1dcc59e1fc83db6f157c60_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..5cc65620c579d303addf85e7b3e18323d73bf240
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/318886a86a1dcc59e1fc83db6f157c60_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:c14f6a6c9e5c8ff341b4c92dfdca79f3a71238365bc171d984097e7c6914c60e
+size 10244
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/3da1a07cb87051bf616c9876db958cf0_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/3da1a07cb87051bf616c9876db958cf0_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..9e6f0b643ee11ab03993c73224cd3d6e2ae3b99b
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/3da1a07cb87051bf616c9876db958cf0_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:6b93413e4aee8028d731086d5020215b637c8ab17265547a5c313f8a378fafc0
+size 19543
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/3db5d62ad46e33647ec2b1ad6d2703bb_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/3db5d62ad46e33647ec2b1ad6d2703bb_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..18af6cef5f0e506ccb8829f572004be1017880c5
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/3db5d62ad46e33647ec2b1ad6d2703bb_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:49f7f493ef3e252eda3413b83f90b12a919a244aac879a5744d0e53c4da3fc70
+size 17968
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/41af98c5f15e6022f8ddde55567cf56e_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/41af98c5f15e6022f8ddde55567cf56e_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..884fca5ead1a79d50d1570410c8782cae507f273
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/41af98c5f15e6022f8ddde55567cf56e_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:cfcb5c406b731b2a79c6d5c2ad1ec39a1f9cd0492418d878f932a9f350b6ab66
+size 11015
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/487c58c79e44e6cf98b6368b6667b9c6_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/487c58c79e44e6cf98b6368b6667b9c6_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..9f10c0e818ce176a5fa3b4b6af6327cb08be86a8
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/487c58c79e44e6cf98b6368b6667b9c6_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:3c91ec32010928a9ef40d5a3b1103eaa1a7a97e84a6b4ab5d9d59e7c2e507642
+size 27060
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/4b587081b669e7c6695b0e5db5ea7f6d_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/4b587081b669e7c6695b0e5db5ea7f6d_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..4d7c6aa5e8051e18c0ecb45203c85eab22e9c635
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/4b587081b669e7c6695b0e5db5ea7f6d_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:bda978995d97f5a30ddcc5cd7b2336a2a7198b73300a2aa54c06d6ad008128ba
+size 39650
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/4c1ea859b93043f2fa17a8fe72fb6176_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/4c1ea859b93043f2fa17a8fe72fb6176_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..e66d16c188dfe7da9462681ce1142a7237924e5c
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/4c1ea859b93043f2fa17a8fe72fb6176_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:d6bffe627a0cea42a0ff8f9d929114a329b067559725f75cad9fe3a45e65984b
+size 27379
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/5414f65867392f05ba0063b208eeb5e1_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/5414f65867392f05ba0063b208eeb5e1_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..6a727eef064257af26f7b1c976a3afdf018849ec
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/5414f65867392f05ba0063b208eeb5e1_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:a2d7e70fa2b493fd6f75a13f1a690f9fa4e585723991ab236b59df059deb7eee
+size 19450
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/56680df276d8e8d21e5ed5c8e21527c6_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/56680df276d8e8d21e5ed5c8e21527c6_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..5da7dc1c39e23aa63647a14101b69452a826be86
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/56680df276d8e8d21e5ed5c8e21527c6_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:67baf3f71eaae9d47140b9ead623bd70badfd34b75a03b1f4272975af8f56c0d
+size 3434
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/60a40901e77feeb97ab6cf9c6d9418c3_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/60a40901e77feeb97ab6cf9c6d9418c3_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..ef33b4cf1b8618bbdce4f4e96c2a0a3026fedff6
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/60a40901e77feeb97ab6cf9c6d9418c3_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:a20fab3157e76513998bb682f6b9f3aed0458e1c565ba53382cb1c61028957c6
+size 125486
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/627c5195eaae3bc7e34cbc4dbdb6f9a8_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/627c5195eaae3bc7e34cbc4dbdb6f9a8_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..13ec78d3dd38aa8d86331e58251876959d1c80ef
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/627c5195eaae3bc7e34cbc4dbdb6f9a8_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:461819edd0b731bf4f61c301db9e563b7b338170aec5e4bb1b0805087313ab0b
+size 17776
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/65b5e4a95d403df0ea5e8ff94f162a6a_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/65b5e4a95d403df0ea5e8ff94f162a6a_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..2207f58a789521fdb520e0d6830b8a0e1b144850
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/65b5e4a95d403df0ea5e8ff94f162a6a_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:e6d2e0c20ed3734203df7c187229c6da367e39044d85f0cf52ce7a1e7f8df9b8
+size 104662
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/6629e8a87e7552e2454b7c3e9f6d73a0_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/6629e8a87e7552e2454b7c3e9f6d73a0_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..d9fe6bf70bbdefeba20ec154c09d86276ff9694d
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/6629e8a87e7552e2454b7c3e9f6d73a0_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:abfe7297aceede2aaff86c440b1396b8c7952e76ee332d836403e04cc71f7fed
+size 11302
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/66bf96eec8f739d5e7c9957a178e34e2_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/66bf96eec8f739d5e7c9957a178e34e2_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..17d8ae7b086e53401c0ed552e5f3e8d2ade4a865
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/66bf96eec8f739d5e7c9957a178e34e2_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:d656e2a5f7ff4a2b97f40534ad4082dfa4e18bd7fa76040a8d755daac2fee1f6
+size 262961
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/66fb62ebfc68240e7523d7d1ac7f1656_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/66fb62ebfc68240e7523d7d1ac7f1656_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..2a19987c8ee0f7377a79c883a089391cddfe882b
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/66fb62ebfc68240e7523d7d1ac7f1656_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:422dc632f9344ca975a140f08c236c7f2084718ef476062f12996342c99d4dc2
+size 42247
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/6929132b4964d52244da61d4614bc4d6_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/6929132b4964d52244da61d4614bc4d6_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..7bdbfedf33393ca4efdd69999ce7b762b91f8cd5
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/6929132b4964d52244da61d4614bc4d6_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:d75462db6db4b514da9603ba395dae36d1b76f7d2ecbf4c270f974800184b1c2
+size 12523
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/6a993bfdf2e00cfad01c4d2188a75d86_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/6a993bfdf2e00cfad01c4d2188a75d86_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..9c25c86aeff4da43cd50f228d34193ece0b4dc4e
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/6a993bfdf2e00cfad01c4d2188a75d86_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:d51c8600fe18f209e00d4d61406d6d4ef3d0dd1ba0481ba0937cf66e1deb97fb
+size 13210
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/6ca05954842b17f14dfd52f26b9d43d2_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/6ca05954842b17f14dfd52f26b9d43d2_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..39e1e74913cfe9273b7c2cf3b81d6c67d2428654
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/6ca05954842b17f14dfd52f26b9d43d2_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:459811c2c308ffe1fd288925234c89d1542693f2532d595e993ad6a89e79bb83
+size 14186
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/6f31cdb576d2f15c35c3f266e5f59211_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/6f31cdb576d2f15c35c3f266e5f59211_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..4f44ba755b2fe2e97b2fd28a51e7be4cd20213dd
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/6f31cdb576d2f15c35c3f266e5f59211_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:2fb586ac8ae16d274092399947c6df3cd356c99a4a250f39a8b0a7676b819c36
+size 17078
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/6f659142d4789aa889184459f884787e_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/6f659142d4789aa889184459f884787e_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..96144b12fbb74bcf232545988f9dc01429914d79
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/6f659142d4789aa889184459f884787e_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:5a72cee30ac1391f428457507e2f379033bad4c3bab5e6a4b948b9f9f1b3020c
+size 17907
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/72d448a65347c51989171748789c7d4b_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/72d448a65347c51989171748789c7d4b_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..d0f8b4f862f88f38d2577660462704f7cf9f56ac
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/72d448a65347c51989171748789c7d4b_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:78d23c200e2ea608e55b1ed4406ac7a7fe16b3b68408b7559ecc24c512febf57
+size 76693
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/744acfe8d4e31bcf03f95714c2f6e567_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/744acfe8d4e31bcf03f95714c2f6e567_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..4dea2eb613f782ea2fbaa56145cf421dc413ccb3
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/744acfe8d4e31bcf03f95714c2f6e567_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:b86e77cccb3ea16c58dcb53fe903c0d077607763d2ca73d881c0e7c5c02fa371
+size 14692
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/796d2e601722450d6456085e0a801e1e_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/796d2e601722450d6456085e0a801e1e_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..f7fb50848f59a33bade4271737a227641bb0b487
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/796d2e601722450d6456085e0a801e1e_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:cfd31e3bebc8d80a489f2a612eb40e973b28a20a78fb13a262bb0bcbff43290f
+size 34770
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/7d3d5fb5d09c0cd35a9d637be241651e_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/7d3d5fb5d09c0cd35a9d637be241651e_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..f6c8bb531d8c56c5ff4ce05c04869be864fd5a01
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/7d3d5fb5d09c0cd35a9d637be241651e_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:1252a31538622c97f2a4169fd9704cba76008ffd86c25d7d8b3d96dff1a95634
+size 51747
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/822e033872d5ab16e861571f47b81ba7_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/822e033872d5ab16e861571f47b81ba7_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..0a13790843b6e78b0a000c052cdd73eced6c715c
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/822e033872d5ab16e861571f47b81ba7_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:98c9b4d8259773c15c61bb53a26a936617b1b9d82d7ce654084b97f015d60327
+size 9905
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/838c31609fac483fa2c01c7896a2fd6d_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/838c31609fac483fa2c01c7896a2fd6d_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..fc1b80578125a005b4eb99abbfd572c8b64efeee
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/838c31609fac483fa2c01c7896a2fd6d_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:3e855d2d21dbe24921a81479447369607d38e591dd56fe81cc5ddc364b7e4c04
+size 9311
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/83c2ebae8819e9cdca7eb157a13ee26a_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/83c2ebae8819e9cdca7eb157a13ee26a_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..bb1bc13e452553fcdd46eb5bdd679b6f9b85a1d6
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/83c2ebae8819e9cdca7eb157a13ee26a_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:3d86251523f9ca044b438935f178c0a2452a6a4d4fe5a6d17b7aba33d00c5326
+size 114052
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/856f6b5a43a3ca2bf49b8446412dc6ae_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/856f6b5a43a3ca2bf49b8446412dc6ae_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..bff940cea777e937636bba37c6fd4d8c1888e11d
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/856f6b5a43a3ca2bf49b8446412dc6ae_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:4c7f74a21df28f16d9de525cc1f76ebc79bb0c6b2208628eec46bf5eab6d0bbc
+size 108502
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/886963464425186f4a465fa8155d2a3c_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/886963464425186f4a465fa8155d2a3c_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..5520887af03ac49da6090224dac54c7861200544
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/886963464425186f4a465fa8155d2a3c_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:f18506339e665eec0ae4404eea05b80cfe55286c8bfc3d18d1816f1e8a820ac6
+size 38111
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/88fa0e6558e55b5d54f4d3029b21aabb_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/88fa0e6558e55b5d54f4d3029b21aabb_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..47e23259e8a2a1c34e217855c55eddbabbf18e41
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/88fa0e6558e55b5d54f4d3029b21aabb_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:277afb902c9d4226a5a1d328cd6cb06006f2356f1322f7c8cad88c607e6d87c8
+size 5931
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/8be52e8ae172cee527c14d299d386f3c_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/8be52e8ae172cee527c14d299d386f3c_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..a7f43beacb607d5622481216fe64eff397fec926
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/8be52e8ae172cee527c14d299d386f3c_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:91115a1980266bb5618ac3d67a84fbae8aa7bec92a603d64b172a8ec025a4721
+size 6069
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/8d325fc12b494e42c9ea7ed2a7f327a6_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/8d325fc12b494e42c9ea7ed2a7f327a6_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..748dcf2ea1f735651607e7c765651c0606ece5b2
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/8d325fc12b494e42c9ea7ed2a7f327a6_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:d376e5eb9e8fb9cffb50f9d8a745675a3ae215398676f3d45d7bd8cdf0fc1c30
+size 30688
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/8e80de0cac529b2c3775d677c5203133_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/8e80de0cac529b2c3775d677c5203133_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..65847fc107e57ca962579a8dedbfea12b8fd4cc1
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/8e80de0cac529b2c3775d677c5203133_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:fd7de6a8154383815b63e44c91b2b7a3f478968690f9fba66e7c416d181257f5
+size 3873
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/90183a52275501da5a0fd5c63d837009_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/90183a52275501da5a0fd5c63d837009_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..71b1d7464ce25ff5d980c9dd7e0805274a4313ca
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/90183a52275501da5a0fd5c63d837009_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:91a596da1768c496e313930dfb01f317f9de5604944e1d94255a1c29e070eef5
+size 125474
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/95e259e8cb3519025066052af263f8c0_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/95e259e8cb3519025066052af263f8c0_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..8c13734d53035ddc237bdf856f1a797d663cd258
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/95e259e8cb3519025066052af263f8c0_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:c430a095cb0a30c22d242cc6029ebf2a2bf659044b4786147bf313296010fa80
+size 6041
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/97b3ed12d7f6c65cf3f7187326728409_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/97b3ed12d7f6c65cf3f7187326728409_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..228133788326a75afaf55feed90e030d53bd7426
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/97b3ed12d7f6c65cf3f7187326728409_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:9ccfb9dd5cbc7dd176aef0d80e9704e0c51330f8dabf05ecb22140ad164278a8
+size 27927
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/981668c6be5792b778cccb1af38477e2_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/981668c6be5792b778cccb1af38477e2_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..7260bd26af29b7dc60e83f9ca451c56a49baa75f
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/981668c6be5792b778cccb1af38477e2_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:8bf60fe299609ab65190eecca02da84a1c57f981084a448e9140fead22d37bc5
+size 16028
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/9b39a1d27e49bccd8767e8d5fc0be7fd_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/9b39a1d27e49bccd8767e8d5fc0be7fd_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..0a71daaaf59d22b074cf864ae77ed557433722ce
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/9b39a1d27e49bccd8767e8d5fc0be7fd_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:973e34c4f6cb718164bbb1db1ea7236052c2ab8805b78d5005d0723b25ea7c3e
+size 18961
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/9fc0c37f0024c76bce2fb5115a7f2c50_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/9fc0c37f0024c76bce2fb5115a7f2c50_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..7be0d173fda827e1363cc050305b75979161d6e5
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/9fc0c37f0024c76bce2fb5115a7f2c50_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:f093e7ea98c59dcf3acc91071eb749ba39dd23f9c46955c15d38982549f25fd5
+size 125357
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/a320e67b369bfde4a5fa360b100da55c_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/a320e67b369bfde4a5fa360b100da55c_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..f3673d0d964c11fa38f1379f8476308bfef4fe4c
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/a320e67b369bfde4a5fa360b100da55c_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:dbde6e2d6e6be9b69fefc0c31f094f41a958b89d9d7bcf3c313c9ab9c02ee896
+size 17816
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/a5184899f915014fa38608754efcc9c7_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/a5184899f915014fa38608754efcc9c7_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..69c34ffb7f97bd63872c7c5d2ed48763c9767fb9
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/a5184899f915014fa38608754efcc9c7_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:b44ee891a8dcfb0000159af9616076a5b8d7c5b8bf95422b839f0543c236037b
+size 9951
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/a6f9ef297168667527ab18da412f917d_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/a6f9ef297168667527ab18da412f917d_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..077aaa2d4ebec328c0c1d4824bf9b4f87cc5328a
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/a6f9ef297168667527ab18da412f917d_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:35522086785ddd6506af3c658673e0fb1937ad24f9326b2a8e7eb28dab2be94e
+size 39773
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/a7c4533d526366db3c7f9d57de31c314_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/a7c4533d526366db3c7f9d57de31c314_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..0b6ac0fe4cd3c8a0a17d75e51800c03057381451
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/a7c4533d526366db3c7f9d57de31c314_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:102362d3c0f2fc47defd952a4e3ff43f8bf85afd4e5a86d67cf395de75a753f6
+size 118303
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/ada2aa7cce9cff9cf116d9ae2b8b7c27_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/ada2aa7cce9cff9cf116d9ae2b8b7c27_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..59779fffc00c383a997b1f6152bdb5edb6e0db4f
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/ada2aa7cce9cff9cf116d9ae2b8b7c27_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:0473943f7e59f8eee7032fb00a12dd2627fb35453116f30237a6c69640f4de7c
+size 113627
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/aec32fe54f8d88d7a631e4cb8d76e70d_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/aec32fe54f8d88d7a631e4cb8d76e70d_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..efed699be5b0031ffe5acdf8ba56da241551dc78
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/aec32fe54f8d88d7a631e4cb8d76e70d_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:c48ab74fe849b7ce3ad0a03d68dd181e3f43b2d026522942cd70f13a236c28f9
+size 30026
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/b0d4609bc46c2d88a8318706bb5321f7_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/b0d4609bc46c2d88a8318706bb5321f7_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..8d912be24ebb8c4e2afe804763cb753c51e86559
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/b0d4609bc46c2d88a8318706bb5321f7_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:5057befe3b533d52877c6d38a18ee45661ebb5d8226c391315da7f64c5a72e0d
+size 18898
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/b2ddf2a678bd20b1b491023eb1db6458_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/b2ddf2a678bd20b1b491023eb1db6458_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..e25c998947be3dba55cd28d09947b8ba30f8285b
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/b2ddf2a678bd20b1b491023eb1db6458_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:95c2994da33e79f281167f0a1ff15043b25cd703e7597ef370f05cb5aa62353a
+size 35500
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/b44f89b176c971c7dd264c07bfef2c2a_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/b44f89b176c971c7dd264c07bfef2c2a_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..d76b9291023c820b76d7449f986ed54e2f0bd674
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/b44f89b176c971c7dd264c07bfef2c2a_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:7ef1e94edf2249872959a09152422391ec54712a046fa7af4be638d80233f2df
+size 8271
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/b4f6d3668f7e851eaff07ccf26001623_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/b4f6d3668f7e851eaff07ccf26001623_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..78afacf54dc559a2bdccad4441e4a4ee013fbee1
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/b4f6d3668f7e851eaff07ccf26001623_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:3406622ae67ceec9d19c3a0ec119ded566977a03736cf99cb831d547a99bdc03
+size 46855
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/b76d1b06cf06e1c28f844e68507b40ed_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/b76d1b06cf06e1c28f844e68507b40ed_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..7d2d6d1ca9806b1eca03cd3d1e4aed7a66217bba
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/b76d1b06cf06e1c28f844e68507b40ed_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:50ca321d8687a9e2e0057b5f9952a16b4bc9c8a386612595589c9284e56f99ed
+size 115924
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/bb3354f497635d15bef873577125c48d_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/bb3354f497635d15bef873577125c48d_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..97dbf0078d897bab9f3d98170dbdedd9e2a862de
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/bb3354f497635d15bef873577125c48d_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:1a19100510d384984358a27475b338047e381e6dd8741d8e62254ea1075c113d
+size 13712
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/bc9d0c0b02cbe628b1b6548cc1107734_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/bc9d0c0b02cbe628b1b6548cc1107734_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..1c08b4209cf3980c5b51669a0dd0f4dd39aa7f0b
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/bc9d0c0b02cbe628b1b6548cc1107734_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:5f64a88a3beb2c457a0e36cc7fb1e8f0eba4655ed916de89d65f2cf80a7262e5
+size 9814
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/c000f54c4c4bddaccf38fa236c90f280_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/c000f54c4c4bddaccf38fa236c90f280_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..91255db5ad5fcb8eed52416b91b4452c64ecbacc
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/c000f54c4c4bddaccf38fa236c90f280_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:544ec08fd79bcbe8ef883eacc8e45191803b0034f7488cc2c504bae69de9dd15
+size 8304
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/c00d3fb4f9d9609639a6e7d7a356afd3_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/c00d3fb4f9d9609639a6e7d7a356afd3_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..583c40f90c7ee8d1dcabfea4677198ccecb32da7
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/c00d3fb4f9d9609639a6e7d7a356afd3_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:14905b42c16f4e8009cbf024e52d5bb3b9c5ac1c36331eaacabbb4aa518d6cc1
+size 77244
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/c020c072c67473d7823d1f9551942732_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/c020c072c67473d7823d1f9551942732_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..687f25448294af438b432c1ee40a3843eced026c
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/c020c072c67473d7823d1f9551942732_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:21bfad486560822f040cd0b18f5b7599351b98fb532a674cd1b6c2cfdcb0019c
+size 77115
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/c19f37cdfc7768db716bfc0cc5934cfb_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/c19f37cdfc7768db716bfc0cc5934cfb_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..824d3208559b96a55e0fdb5119649cec030b9e90
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/c19f37cdfc7768db716bfc0cc5934cfb_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:3c79f7e4273344d37215bee5eb96510b9accca2573cd506bece373f96a0178de
+size 22813
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/c42e926097d01653b793c04b49e764b2_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/c42e926097d01653b793c04b49e764b2_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..2bd712041157d629011bc44f0257e63f3f54336f
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/c42e926097d01653b793c04b49e764b2_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:9c4ea6dd44c06709aaca166c8de83a7f560663e25526414252d5464298925406
+size 21241
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/cc98b584f9b31fe69948e3fa65a3ba69_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/cc98b584f9b31fe69948e3fa65a3ba69_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..96a41ee27b792df0831eb4aebe4d1feb1f5fa623
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/cc98b584f9b31fe69948e3fa65a3ba69_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:3e5e4f2c9412af0ee0cf38a13b25e35e88aaddcb45f2ef415d54d428ae688678
+size 42650
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/ccfd5ed8d9795009e923e2a0cacbcd6e_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/ccfd5ed8d9795009e923e2a0cacbcd6e_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..055fbe9eb56daaaf493efea7f36e7cb202f66512
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/ccfd5ed8d9795009e923e2a0cacbcd6e_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:d18a47156f3c54305e045e7c6edaa70e9d0d694b034d6a8a72b22482fe9f05da
+size 5837
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/cdd9c57c9c578160002ead5cdaef414d_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/cdd9c57c9c578160002ead5cdaef414d_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..289ca3ef3e27060ebda13db32def278733db5fbc
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/cdd9c57c9c578160002ead5cdaef414d_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:3687e6795398f057a35eb9c0c65cb8cc480d1d9d40bb47074bbee1479e77e1c5
+size 9807
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/d665f520401064e5cfeed94d226f48bd_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/d665f520401064e5cfeed94d226f48bd_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..ba2b63b8801e950584a446ac82c4704297d1bf94
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/d665f520401064e5cfeed94d226f48bd_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:6e1589cf0f0143bdb19061d20d16e24fdea0ac495cbc78ba5f69dfc5299064f2
+size 74165
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/dae88eec6d1005984029b794ff8b7a9e_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/dae88eec6d1005984029b794ff8b7a9e_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..9a04df4d33623f3f37d294e02f75c538fc3e3770
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/dae88eec6d1005984029b794ff8b7a9e_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:4dbed186b9b7d231cce1f0b0c03149dda9c284bc16574ed5dc1912fdfdc3ee8b
+size 103874
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/dfa2632198a25c9c884502cdc0597c6e_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/dfa2632198a25c9c884502cdc0597c6e_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..c01be9805dd0a301c7f5ef391ba41d052ba4868b
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/dfa2632198a25c9c884502cdc0597c6e_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:08747beff3eb79241c2d7c935934ae6c6489969cdd313b36e1e7204a623f5d7d
+size 43786
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/dfafe39c233a62ec8ebd71e42992c14d_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/dfafe39c233a62ec8ebd71e42992c14d_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..a501101338a9009780b9a5aeb5c2d52d554a4295
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/dfafe39c233a62ec8ebd71e42992c14d_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:a53105f5e5a607a40fbc15580b1d716e1d853852ee48591721f1b791b7dcfdb1
+size 137258
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/e2b7490a3455c66c85db12872c78fcc3_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/e2b7490a3455c66c85db12872c78fcc3_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..7231a5042800d375a75c01b129a008e3e191c2d7
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/e2b7490a3455c66c85db12872c78fcc3_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:23bb4f5862593165f50f9e6d566b780bea0c65b560b5a108dd1394bedb6ef9d0
+size 97196
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/e7c92619d947e56ee7fa5d2ded3b40c1_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/e7c92619d947e56ee7fa5d2ded3b40c1_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..0c0c56ed6493037539961d54f3f611403ee91ab8
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/e7c92619d947e56ee7fa5d2ded3b40c1_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:c877aee1b78d3cb74f83b1308a238d3ace14ebdc9a2ae8b7fe06526b80629f57
+size 21601
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/f0b7abcb093621bb310bf61fbe0f0d2d_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/f0b7abcb093621bb310bf61fbe0f0d2d_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..a8fa31416d3ef3c0a7e88010ed72073080be5637
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/f0b7abcb093621bb310bf61fbe0f0d2d_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:ce7aeb1b83ee14500497782a593ef437964335173ff0eee82fe7aa1fe013681c
+size 6082
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/f1091147d93cee4dfa88498610e395a7_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/f1091147d93cee4dfa88498610e395a7_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..5a8b3638120e58e29d0a2df82af47c0e28d7a015
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/f1091147d93cee4dfa88498610e395a7_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:b53cee8b00d95f36cd91cd6995e6a4afeb8439d761517367a86c42fbd283a7de
+size 21073
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/f23879f003c58b57f690e2dc6c95816a_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/f23879f003c58b57f690e2dc6c95816a_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..43970263fbe840b5c1ae1630e08dc153443a2dc0
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/f23879f003c58b57f690e2dc6c95816a_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:2aafa3baba4233de9b61a78b5272cbb715ac51cf78d6cd505c939017fd0ea24e
+size 21771
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/f24f909d837b5476783e1bbea2dfc143_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/f24f909d837b5476783e1bbea2dfc143_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..08ef04b722c943a53b51dff27729acc77362b47e
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/f24f909d837b5476783e1bbea2dfc143_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:31c795e22fa713629d9255ca415912f8310ca0203c86979828ad36d55babf787
+size 6800
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/f324fbc5d5af1e4da9cd932389f0064c_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/f324fbc5d5af1e4da9cd932389f0064c_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..52984110185ab217e5493a781e9c9fa1cb518436
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/f324fbc5d5af1e4da9cd932389f0064c_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:223583e18fe9d565ca15e07a72d91eb9934da9268994152b6a8f4f808696c3e2
+size 5655
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/f92e919c70b7adda2d0e778889f44fae_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/f92e919c70b7adda2d0e778889f44fae_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..5b975f7081e9a7d76eef371cd95a94847e0e9708
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/f92e919c70b7adda2d0e778889f44fae_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:ad9a50f65ef1298da0cf6f912f4004fa5c88fd66ac31348e603449153c1fc10b
+size 59196
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/fef7e3f08b408e4ab937a75f5c8b6bfc_img.jpg b/marked/T/T-REC-T.807-202302-I_PDF-E/fef7e3f08b408e4ab937a75f5c8b6bfc_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..d60c68496405bfb38c8b736dee9a6bd91b32f8cf
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/fef7e3f08b408e4ab937a75f5c8b6bfc_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:42e394c03a6e0e4f7ad873648e07881d38f0cd20e9760ecc3f0be8c6784dfabc
+size 117286
diff --git a/marked/T/T-REC-T.807-202302-I_PDF-E/raw.md b/marked/T/T-REC-T.807-202302-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..ed142e85a99fa7d7110fd8554f5cf7c9eb5866db
--- /dev/null
+++ b/marked/T/T-REC-T.807-202302-I_PDF-E/raw.md
@@ -0,0 +1,5622 @@
+
+
+Recommendation
+
+# **ITU-T T.807 (V2) (02/2023)**
+
+SERIES T: Terminals for telematic services
+
+Still-image compression – JPEG 2000
+
+---
+
+**Information technology – JPEG 2000 image  
+coding system: Secure JPEG 2000**
+
+## ITU-T T-SERIES RECOMMENDATIONS **TERMINALS FOR TELEMATIC SERVICES**
+
+|                                                     |                    |
+|-----------------------------------------------------|--------------------|
+| Facsimile – Framework                               | T.0–T.19           |
+| Still-image compression – Test charts               | T.20–T.29          |
+| Facsimile – Group 3 protocols                       | T.30–T.39          |
+| Colour representation                               | T.40–T.49          |
+| Character coding                                    | T.50–T.59          |
+| Facsimile – Group 4 protocols                       | T.60–T.69          |
+| Telematic services – Framework                      | T.70–T.79          |
+| Still-image compression – JPEG-1, Bi-level and JBIG | T.80–T.89          |
+| Telematic services – ISDN Terminals and protocols   | T.90–T.99          |
+| Videotext – Framework                               | T.100–T.109        |
+| Data protocols for multimedia conferencing          | T.120–T.149        |
+| Telewriting                                         | T.150–T.159        |
+| Multimedia and hypermedia framework                 | T.170–T.189        |
+| Cooperative document handling                       | T.190–T.199        |
+| Telematic services – Interworking                   | T.300–T.399        |
+| Open document architecture                          | T.400–T.429        |
+| Document transfer and manipulation                  | T.430–T.449        |
+| Document application profile                        | T.500–T.509        |
+| Communication application profile                   | T.510–T.559        |
+| Telematic services – Equipment characteristics      | T.560–T.619        |
+| General multimedia application frameworks           | T.620–T.649        |
+| User interfaces - Accessibility and human factors   | T.700–T.799        |
+| <b>Still-image compression – JPEG 2000</b>          | <b>T.800–T.829</b> |
+| Still-image compression   JPEG XR                   | T.830–T.849        |
+| Still-image compression – JPEG-1 extensions         | T.850–T.899        |
+
+*For further details, please refer to the list of ITU-T Recommendations.*
+
+## Information technology – JPEG 2000 image coding system: Secure JPEG 2000
+
+## Summary
+
+Rec. ITU-T T.807 | ISO/IEC 15444-8 provides a syntax that allows security services to be applied to JPEG 2000 coded image data. Security services include confidentiality, integrity verification, source authentication, conditional access, secure scalable streaming and secure transcoding. The syntax allows these security services to be applied to coded and uncoded image data in part or in its entirety. This maintains the inherent features of JPEG 2000 such as scalability and access to various spatial areas, resolution levels, colour components, and quality layers, while providing security services on these elements.
+
+This second edition:
+
+- 1) consolidates all solved/outstanding amendments and corrigenda published since the first edition;
+- 2) removes the clause on Registration Authority (first edition's clause 7);
+- 3) removes the annex of patent statements (first edition's Annex D).
+
+This Recommendation | International Standard was prepared by Joint Technical Committee ISO/IEC JTC 1, *Information technology*, Subcommittee SC 29, *Coding of audio, picture, multimedia and hypermedia information*, in collaboration with ITU-T SG16. The identical text is published in ISO/IEC as ISO/IEC 15444-8.
+
+## History
+
+| Edition | Recommendation            | Approval   | Study Group | Unique ID*                                                                |
+|---------|---------------------------|------------|-------------|---------------------------------------------------------------------------|
+| 1.0     | ITU-T T.807               | 2006-05-29 | 16          | <a href="http://handle.itu.int/11.1002/1000/8830">11.1002/1000/8830</a>   |
+| 1.1     | ITU-T T.807 (2006) Amd. 1 | 2008-03-15 | 16          | <a href="http://handle.itu.int/11.1002/1000/9364">11.1002/1000/9364</a>   |
+| 2.0     | ITU-T T.807 (V2)          | 2023-02-13 | 16          | <a href="http://handle.itu.int/11.1002/1000/15208">11.1002/1000/15208</a> |
+
+## Keywords
+
+Image security, jpsec, JPEG 2000, security, still image.
+
+---
+
+\* To access the Recommendation, type the URL <http://handle.itu.int/> in the address field of your web browser, followed by the Recommendation's unique ID. For example, <http://handle.itu.int/11.1002/1000/11830-en>.
+
+## FOREWORD
+
+The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis.
+
+The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics.
+
+The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1.
+
+In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC.
+
+### NOTE
+
+In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party.
+
+## INTELLECTUAL PROPERTY RIGHTS
+
+ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process.
+
+As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at <http://www.itu.int/ITU-T/ipr/>.
+
+© ITU 2023
+
+All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU.
+
+## CONTENTS
+
+|                                                                                                        | <i>Page</i> |
+|--------------------------------------------------------------------------------------------------------|-------------|
+| 1 Scope .....                                                                                          | 1           |
+| 2 Normative references .....                                                                           | 1           |
+| 3 Definitions .....                                                                                    | 1           |
+| 4 Symbols and abbreviations .....                                                                      | 4           |
+| 5 JPSEC syntax .....                                                                                   | 5           |
+| 5.1 JPSEC framework overview .....                                                                     | 5           |
+| 5.2 JPSEC security services .....                                                                      | 6           |
+| 5.3 Comments on design and implementation of secure JPSEC systems .....                                | 7           |
+| 5.4 Byte aligned segment (BAS) .....                                                                   | 8           |
+| 5.5 Main security marker (SEC) .....                                                                   | 9           |
+| 5.6 JPSEC tools .....                                                                                  | 13          |
+| 5.7 Zone of Influence (ZOI) syntax .....                                                               | 16          |
+| 5.8 Protection method template syntax (T) .....                                                        | 25          |
+| 5.9 Processing domain syntax (PD) .....                                                                | 34          |
+| 5.10 Granularity syntax (G) .....                                                                      | 35          |
+| 5.11 Value list syntax (V) .....                                                                       | 36          |
+| 5.12 Relationships among ZOI, Granularity (G) and Value List (VL) .....                                | 37          |
+| 5.13 In-codestream security marker (INSEC) .....                                                       | 38          |
+| 6 Normative-syntax usage examples (informative) .....                                                  | 39          |
+| 6.1 ZOI examples .....                                                                                 | 39          |
+| 6.2 Key information template examples .....                                                            | 43          |
+| 6.3 JPSEC normative tool examples .....                                                                | 44          |
+| 6.4 Distortion field examples .....                                                                    | 50          |
+| Annex A Guidelines and use cases .....                                                                 | 52          |
+| A.1 A class of JPSEC applications .....                                                                | 52          |
+| Annex B Interoperability .....                                                                         | 58          |
+| B.1 Rec. ITU-T T.800   ISO/IEC 15444-1 – Core coding system .....                                      | 58          |
+| B.2 Rec. ITU-T T.808   ISO/IEC 15444-9 – JPIP .....                                                    | 58          |
+| B.3 Rec. ITU-T T.810   ISO/IEC 15444-11 – JPWL .....                                                   | 59          |
+| Annex C File format security .....                                                                     | 62          |
+| C.1 Scope .....                                                                                        | 62          |
+| C.2 Introduction .....                                                                                 | 62          |
+| C.3 Extension to ISO base media file format .....                                                      | 64          |
+| C.4 Elementary stream and sample definitions .....                                                     | 72          |
+| C.5 Protection at file format level .....                                                              | 74          |
+| C.6 Examples (Informative) .....                                                                       | 75          |
+| C.7 Boxes defined in ISO/IEC 14496-12 (informative) .....                                              | 85          |
+| Annex D Technology examples .....                                                                      | 90          |
+| D.1 Introduction .....                                                                                 | 90          |
+| D.2 A flexible access control scheme for JPEG 2000 codestreams .....                                   | 90          |
+| D.3 A unified authentication framework for JPEG 2000 images .....                                      | 92          |
+| D.4 A simple packet-based encryption method for JPEG 2000 codestreams .....                            | 94          |
+| D.5 Encryption tool for JPEG 2000 access control .....                                                 | 97          |
+| D.6 Key generation tool for JPEG 2000 access control .....                                             | 99          |
+| D.7 Wavelet and bitstream domain scrambling for conditional access control .....                       | 102         |
+| D.8 Progressive access for JPEG 2000 codestream .....                                                  | 104         |
+| D.9 Scalable authenticity of JPEG 2000 codestreams .....                                               | 106         |
+| D.10 JPEG 2000 data confidentiality and access control system based on data splitting and luring ..... | 108         |
+| D.11 Secure scalable streaming and secure transcoding .....                                            | 111         |
+| Bibliography .....                                                                                     | 115         |
+
+# FIGURES
+
+|                                                                                               | <i>Page</i> |
+|-----------------------------------------------------------------------------------------------|-------------|
+| Figure 1 – Overview of the conceptual steps in JPSEC framework .....                          | 5           |
+| Figure 2 – Byte aligned segment (BAS) structure .....                                         | 8           |
+| Figure 3 – Main security marker segment syntax .....                                          | 9           |
+| Figure 4 – Main security marker syntax when multiple marker segments are used .....           | 10          |
+| Figure 5 – Codestream security parameters ( $P_{SEC}$ ) syntax .....                          | 10          |
+| Figure 6 – TRLCF tag descriptor ( $P_{TRLCF}$ ) syntax .....                                  | 11          |
+| Figure 7 – Use of multiple JPSEC tools .....                                                  | 12          |
+| Figure 8 – JPSEC tool syntax ( $Tool^{(i)}$ ) .....                                           | 13          |
+| Figure 9 – Parameters ( $P_{ID}$ ) syntax for JPSEC normative tools ( $t = 0$ ) .....         | 14          |
+| Figure 10 – $ID_{RA}$ syntax .....                                                            | 15          |
+| Figure 11 – Zone of Influence conceptual structure .....                                      | 17          |
+| Figure 12 – ZOI syntax .....                                                                  | 17          |
+| Figure 13 – Zone description class structure ( $DC_{zoi}$ ) .....                             | 18          |
+| Figure 14 – Zone syntax consists of a description class and one or more parameter sets .....  | 18          |
+| Figure 15 – Distortion field syntax .....                                                     | 20          |
+| Figure 16 – Distortion field syntax .....                                                     | 21          |
+| Figure 17 – Relative importance field syntax .....                                            | 21          |
+| Figure 18 – Bit-rate field syntax .....                                                       | 22          |
+| Figure 19 – ZOI example using image related descriptions .....                                | 23          |
+| Figure 20 – ZOI example using image related and non-image related descriptions .....          | 23          |
+| Figure 21 – A second ZOI example using image related and non-image related descriptions ..... | 24          |
+| Figure 22 – ZOI description parameter syntax .....                                            | 24          |
+| Figure 23 – Decryption template syntax .....                                                  | 26          |
+| Figure 24 – Block cipher template syntax .....                                                | 27          |
+| Figure 25 – Stream cipher template syntax .....                                               | 28          |
+| Figure 26 – Asymmetric cipher template syntax .....                                           | 29          |
+| Figure 27 – Authentication template syntax .....                                              | 29          |
+| Figure 28 – Hash-based authentication template .....                                          | 30          |
+| Figure 29 – Cipher-based authentication template syntax .....                                 | 31          |
+| Figure 30 – Digital signature template syntax .....                                           | 32          |
+| Figure 31 – Hash template syntax .....                                                        | 33          |
+| Figure 32 – Key information template syntax .....                                             | 33          |
+| Figure 33 – ITU-T X.509 certificate syntax .....                                              | 34          |
+| Figure 34 – Processing domain syntax .....                                                    | 34          |
+| Figure 35 – Granularity syntax .....                                                          | 35          |
+| Figure 36 – Value list field syntax .....                                                     | 37          |
+| Figure 37 – Granularity Level (GL) is resolution .....                                        | 37          |
+
+|                                                                                                                              | <i>Page</i> |
+|------------------------------------------------------------------------------------------------------------------------------|-------------|
+| Figure 38 – Granularity Level (GL) is layer .....                                                                            | 38          |
+| Figure 39 – In-codestream security marker syntax .....                                                                       | 38          |
+| Figure A.1 – Overview of a secure JPEG 2000 image distribution application .....                                             | 52          |
+| Figure A.2 – Legend description .....                                                                                        | 53          |
+| Figure A.3 – Encryption procedure .....                                                                                      | 54          |
+| Figure A.4 – Decryption procedure .....                                                                                      | 54          |
+| Figure A.5 – Signature generation procedure .....                                                                            | 55          |
+| Figure A.6 – Authentication procedure .....                                                                                  | 56          |
+| Figure A.7 – ICV generation procedure .....                                                                                  | 56          |
+| Figure A.8 – Integrity check procedure .....                                                                                 | 57          |
+| Figure B.1 – Typical JPWL and JPSEC combination .....                                                                        | 60          |
+| Figure C.1 – System diagram for time-sequenced scalable media .....                                                          | 63          |
+| Figure C.2 – Self-contained ES and scalable composed ES .....                                                                | 73          |
+| Figure C.3 – Self-contained ES and decodable composed ES .....                                                               | 73          |
+| Figure C.4 – Relationship between iloc, iinf and ipro .....                                                                  | 74          |
+| Figure C.5 – An example sample description entry protected by authentication scheme followed by description scheme .....     | 75          |
+| Figure C.6 – Example 1: Item-based protection of JP2 file (authentication) .....                                             | 76          |
+| Figure C.7 – Example 2: Item-based protection of a JPEG 2000 images (encryption) .....                                       | 77          |
+| Figure C.8 – Example 2: Secure transcoding to lower resolution (discarding resolution 2) .....                               | 77          |
+| Figure C.9 – Example 3: Item-based protection of a JPEG 2000 image (Authentication) .....                                    | 78          |
+| Figure C.10 – Example 3: Transcoding to resolution 1 .....                                                                   | 79          |
+| Figure C.11 – Example 4: Sample-based protection of a time-sequenced JPEG 2000 pictures .....                                | 80          |
+| Figure C.12 – Example 4: Secure transcoding to lower SNR quality (layer 1) .....                                             | 81          |
+| Figure C.13 – Example 5: Sample-based protection for video browsing or video summarization .....                             | 82          |
+| Figure C.14 – Example 5: Transcoding to shorter time length (discarding the last 5000 pictures) .....                        | 82          |
+| Figure C.15 – Example 6: Authentication transcoding, discarding received but unverifiable packets .....                      | 83          |
+| Figure C.16 – Motion JPEG 2000 file with detailed box structure .....                                                        | 83          |
+| Figure C.17 – Simplified Motion JPEG 2000 box structure showing references .....                                             | 84          |
+| Figure C.18 – Simplified Motion JPEG 2000 box structure showing references after length changing protection operations ..... | 84          |
+| Figure C.19 – JPM file with detailed box structure .....                                                                     | 85          |
+| Figure C.20 – Simplified JPM box structure showing references .....                                                          | 85          |
+| Figure C.21 – JPM box structure showing references after length changing protection operations .....                         | 85          |
+| Figure D.1 – SEC segment syntax .....                                                                                        | 91          |
+| Figure D.2 – P <sub>ID</sub> field syntax .....                                                                              | 91          |
+| Figure D.3 – TP <sub>ID</sub> field syntax .....                                                                             | 91          |
+| Figure D.4 – AK <sub>info</sub> field syntax .....                                                                           | 92          |
+| Figure D.5 – Image protection using unified authentication framework for JPEG 2000 .....                                     | 93          |
+
+|                                                                                                          | <i>Page</i> |
+|----------------------------------------------------------------------------------------------------------|-------------|
+| Figure D.6 – Packet-based encryption principle.....                                                      | 95          |
+| Figure D.7 – Overview of this technology .....                                                           | 100         |
+| Figure D.8 – Block diagram for wavelet domain scrambling .....                                           | 102         |
+| Figure D.9 – Block diagram for bitstream domain scrambling .....                                         | 103         |
+| Figure D.10 – Non-normative protection tool syntax in the case of multiple keys .....                    | 103         |
+| Figure D.11 – Syntax for AP: Wavelet domain scrambling (left), Bitstream domain scrambling (right) ..... | 104         |
+| Figure D.12 – Technical overview of this technology.....                                                 | 105         |
+| Figure D.13 – Non-normative tool syntax .....                                                            | 107         |
+| Figure D.14 – Security parameters TP <sub>ID</sub> syntax .....                                          | 108         |
+| Figure D.15 – System overview .....                                                                      | 110         |
+| Figure D.16 – JPSEC enables end-to-end security and mid-network secure transcoding .....                 | 112         |
+| Figure D.17 – An example of forming a JPSEC codestream.....                                              | 113         |
+
+# TABLES
+
+|                                                                                                | <i>Page</i> |
+|------------------------------------------------------------------------------------------------|-------------|
+| Table 1 – Main security parameter values .....                                                 | 10          |
+| Table 2 – Codestream security parameters (P <sub>SEC</sub> ) in first SEC marker segment ..... | 11          |
+| Table 3 – Semantics for F <sub>PSEC</sub> values (FBAS).....                                   | 11          |
+| Table 4 – Parameter field for TRLCF tag descriptor (P <sub>TRLCF</sub> ).....                  | 12          |
+| Table 5 – JPSEC tool parameter values.....                                                     | 13          |
+| Table 6 – JPSEC normative tool Template ID values (ID <sub>T</sub> ) .....                     | 14          |
+| Table 7 – JPSEC normative tool parameter values.....                                           | 15          |
+| Table 8 – Parameters values in ID <sub>RA</sub> syntax .....                                   | 15          |
+| Table 9 – ID values for JPSEC non-normative tools (ID <sub>RA,id</sub> ).....                  | 16          |
+| Table 10 – Zone of influence field (ZOI) parameter values .....                                | 17          |
+| Table 11 – Zone parameter values.....                                                          | 18          |
+| Table 12 – Description class indicator value .....                                             | 18          |
+| Table 13 – Image related description class .....                                               | 18          |
+| Table 14 – Non-image related description class .....                                           | 19          |
+| Table 15 – Distortion field parameter values.....                                              | 20          |
+| Table 16 – Distortion field parameter values.....                                              | 21          |
+| Table 17 – Relative importance field parameter values.....                                     | 21          |
+| Table 18 – Bit-rate field parameter values.....                                                | 22          |
+| Table 19 – Pzoi <sup>i</sup> parameter values .....                                            | 24          |
+| Table 20 – Mzoi parameter values.....                                                          | 25          |
+| Table 21 – Template ID values (ID <sub>T</sub> ) .....                                         | 25          |
+| Table 22 – Decryption template parameter values .....                                          | 26          |
+| Table 23 – Marker emulation flag values (ME <sub>decry</sub> ).....                            | 26          |
+
+|                                                                                                                                                      | <i>Page</i> |
+|------------------------------------------------------------------------------------------------------------------------------------------------------|-------------|
+| Table 24 – Cipher identifier values ( $CT_{\text{decry}}$ ) .....                                                                                    | 26          |
+| Table 25 – Block cipher identifier values ( $CT_{\text{decry}}$ ) .....                                                                              | 26          |
+| Table 26 – Stream cipher identifier values ( $CT_{\text{decry}}$ ) .....                                                                             | 27          |
+| Table 27 – Asymmetric cipher identifier values ( $CT_{\text{decry}}$ ) .....                                                                         | 27          |
+| Table 28 – Block cipher template values .....                                                                                                        | 27          |
+| Table 29 – Block cipher mode values ( $M_{bc}$ ) .....                                                                                               | 28          |
+| Table 30 – Padding mode for block cipher ( $P_{bc}$ ) .....                                                                                          | 28          |
+| Table 31 – Stream cipher template values .....                                                                                                       | 28          |
+| Table 32 – Asymmetric cipher template values .....                                                                                                   | 29          |
+| Table 33 – Authentication template parameter values .....                                                                                            | 29          |
+| Table 34 – Authentication methods ( $M_{\text{auth}}$ ) .....                                                                                        | 29          |
+| Table 35 – Hash-based authentication template parameter values .....                                                                                 | 30          |
+| Table 36 – Hash-based authentication method identifier ( $M_{\text{HMAC}}$ ) .....                                                                   | 30          |
+| Table 37 – Hash function identifier ( $H_{\text{HMAC}}$ ) .....                                                                                      | 31          |
+| Table 38 – MAC template values .....                                                                                                                 | 31          |
+| Table 39 – Cipher-based authentication method ( $C_{\text{CMAC}}$ ) .....                                                                            | 32          |
+| Table 40 – Digital signature template values .....                                                                                                   | 32          |
+| Table 41 – Digital signature methods ( $M_{\text{DS}}$ ) .....                                                                                       | 32          |
+| Table 42 – Hash template parameter values .....                                                                                                      | 33          |
+| Table 43 – Key template values .....                                                                                                                 | 33          |
+| Table 44 – Key information identifier values ( $KID_{\text{KT}}$ ) .....                                                                             | 34          |
+| Table 45 – ITU-T X.509 certificate values ( $KI_{\text{KT}}$ if $KID_{\text{KT}} = 2$ ) .....                                                        | 34          |
+| Table 46 – Encoding rule values ( $ER_{\text{KT}}$ ) .....                                                                                           | 34          |
+| Table 47 – Processing domain parameters .....                                                                                                        | 35          |
+| Table 48 – Processing Domain (PD) parameter values .....                                                                                             | 35          |
+| Table 49 – Processing domain field ( $F_{\text{PD}}$ ) parameter values in wavelet coefficient domain and quantized wavelet coefficient domain ..... | 35          |
+| Table 50 – Processing domain field ( $F_{\text{PD}}$ ) parameter values in codestream domain .....                                                   | 35          |
+| Table 51 – Granularity parameter values ( $G$ ) .....                                                                                                | 36          |
+| Table 52 – Processing order values ( $PO$ ) .....                                                                                                    | 36          |
+| Table 53 – Granularity level values ( $GL$ ) .....                                                                                                   | 36          |
+| Table 54 – Value list field ( $V$ ) parameter values .....                                                                                           | 37          |
+| Table 55 – In-codestream security parameter values ( $\text{INSEC}$ ) .....                                                                          | 39          |
+| Table 56 – Relevance zone values ( $R$ ) .....                                                                                                       | 39          |
+| Table 57 – ZOI in example 1 .....                                                                                                                    | 39          |
+| Table 58 – ZOI in example 2 .....                                                                                                                    | 40          |
+| Table 59 – ZOI in example 3 .....                                                                                                                    | 41          |
+| Table 60 – ZOI in example 4 .....                                                                                                                    | 41          |
+| Table 61 – ZOI in example 5 .....                                                                                                                    | 42          |
+
+|                                                                                                          | <i>Page</i> |
+|----------------------------------------------------------------------------------------------------------|-------------|
+| Table 62 – ZOI in example 6 .....                                                                        | 43          |
+| Table 63 – Key information in example 1 .....                                                            | 43          |
+| Table 64 – Key information in example 2 .....                                                            | 43          |
+| Table 65 – Key information in example 3 .....                                                            | 44          |
+| Table 66 – Key information in example 4 .....                                                            | 44          |
+| Table 67 – SEC marker segment for example 1 .....                                                        | 45          |
+| Table 68 – ZOI example .....                                                                             | 45          |
+| Table 69 – P <sub>ID</sub> example .....                                                                 | 46          |
+| Table 70 – Decryption template example .....                                                             | 47          |
+| Table 71 – Key template example .....                                                                    | 47          |
+| Table 72 – The SEC marker segment .....                                                                  | 48          |
+| Table 73 – ZOI signalling .....                                                                          | 48          |
+| Table 74 – P <sub>ID</sub> signalling parameters .....                                                   | 49          |
+| Table 75 – Associating distortion field to two data segments (extension of ZOI example 3 in 6.1.3) ..... | 50          |
+| Table 76 – Signalling a range of packets and associating distortions for each packet .....               | 51          |
+| Table C.1 – List of existing and new boxes .....                                                         | 64          |
+| Table D.1 – Example parameters for this scheme .....                                                     | 91          |
+| Table D.2 – P <sub>ID</sub> parameters .....                                                             | 91          |
+| Table D.3 – TP <sub>ID</sub> parameters .....                                                            | 92          |
+| Table D.4 – AK <sub>info</sub> parameters .....                                                          | 92          |
+| Table D.5 – Syntax for semi-fragile authentication .....                                                 | 93          |
+| Table D.6 – Example of Zone of Influence, with spatial coordinates, resolutions and layers .....         | 95          |
+| Table D.7 – Decryption template description, in the case of AES-192/CBC .....                            | 96          |
+| Table D.8 – Processing domain syntax .....                                                               | 96          |
+| Table D.9 – Granularity and value list syntax .....                                                      | 97          |
+| Table D.10 – Example parameters for this technology .....                                                | 98          |
+| Table D.11 – Example ZOI of this key generation tool .....                                               | 98          |
+| Table D.12 – P <sub>ID</sub> for this technology .....                                                   | 99          |
+| Table D.13 – Example of decryption template of this technology .....                                     | 99          |
+| Table D.14 – Recommended parameter in this technology .....                                              | 100         |
+| Table D.15 – Example ZOI of this key generation tool .....                                               | 101         |
+| Table D.16 – P <sub>ID</sub> for this technology .....                                                   | 101         |
+| Table D.17 – Example of decryption template of this technology .....                                     | 102         |
+| Table D.18 – Syntax and semantic for P <sub>ID</sub> .....                                               | 103         |
+| Table D.19 – Syntax and semantic for AP .....                                                            | 104         |
+| Table D.20 – Example parameters for this tool .....                                                      | 105         |
+| Table D.21 – Example ZOI of this technology .....                                                        | 106         |
+| Table D.22 – P <sub>ID</sub> for this technology .....                                                   | 106         |
+
+|                                                                                                     | <i>Page</i> |
+|-----------------------------------------------------------------------------------------------------|-------------|
+| Table D.23 – Example of decryption template of this technology .....                                | 106         |
+| Table D.24 – Non-normative tool parameters .....                                                    | 108         |
+| Table D.25 – Security parameters.....                                                               | 108         |
+| Table D.26 – Parameter values for this tool .....                                                   | 111         |
+| Table D.27 – Parameter values for template protection tool, processing domain and granularity ..... | 114         |
+| Table D.28 – Parameter values for authentication template protection tool.....                      | 114         |
+
+## Introduction
+
+In the "Digital Age", the Internet provides many new opportunities for right-holders regarding the electronic distribution of their work (books, videos, music, images, etc.).
+
+At the same time, new information technology radically simplifies the access of content for the user. This goes hand in hand with the all-pervasive problem of pirated digital copies – with the same quality as the originals – and "file-sharing" in peer-to-peer networks, which gives rise to continued complaints about great losses by the content industry.
+
+World Intellectual Property Organization (WIPO) and its Member countries (170) have an important role to play in assuring that copyright, and the cultural and intellectual expression it fosters, remains well protected in the 21st century. The new Digital economy and the creative people in every country of the world depend on it. Also in December 1996, WIPO Copyright Treaty (WCT) has been promulgated with two important articles (11 and 12) about technological measures and obligations concerning Right Management Information:
+
+### **Article 11**
+
+#### **Obligations concerning Technological Measures**
+
+*Contracting Parties shall provide adequate legal protection and effective legal remedies against the circumvention of effective technological measures that are used by authors in connection with the exercise of their rights under this Treaty or the Berne Convention and that restrict acts, in respect of their works, which are not authorized by the authors concerned or permitted by law.*
+
+### **Article 12**
+
+#### **Obligations concerning Rights Management Information**
+
+*(1) Contracting Parties shall provide adequate and effective legal remedies against any person knowingly performing any of the following acts knowing, or with respect to civil remedies having reasonable grounds to know, that it will induce, enable, facilitate or conceal an infringement of any right covered by this Treaty or the Berne Convention:*
+
+*(i) to remove or alter any electronic rights management information without authority;*
+
+*(ii) to distribute, import for distribution, broadcast or communicate to the public, without authority, works or copies of works knowing that electronic rights management information has been removed or altered without authority.*
+
+*(2) As used in this Article, "rights management information" means information which identifies the work, the author of the work, the owner of any right in the work, or information about the terms and conditions of use of the work, and any numbers or codes that represent such information, when any of these items of information is attached to a copy of a work or appears in connection with the communication of a work to the public.*
+
+This treaty provides a solid foundation to protect Intellectual Property. As of 2004, about 50 countries ratified this important treaty. Therefore, it is expected that tools and protective methods that are recommended in JPEG 2000 needs ensure the security of transaction, protection of content (IPR), and protection of technologies.
+
+Security issues, such as authentication, data integrity, protection of copyright and Intellectual Property, privacy, conditional access, confidentiality, transaction tracing, to mention a few, are among important features in many imaging applications targeted by JPEG 2000.
+
+The technological means of protecting digital content are described and can be achieved in many ways such as digital watermarking, digital signature, encryption, metadata, authentication, and integrity checking.
+
+This Recommendation | International Standard intends to provide tools and solutions in terms of specifications that allow applications to generate, consume, and exchange Secure JPEG 2000 codestreams. This is referred to as **JPSEC**.
+
+INTERNATIONAL STANDARD  
+ITU-T RECOMMENDATION
+
+## Information technology – JPEG 2000 image coding system: Secure JPEG 2000
+
+### 1 Scope
+
+This Recommendation | International Standard specifies the framework, concepts, and methodology for securing JPEG 2000 codestreams. The scope of this Recommendation | International Standard is to define:
+
+- 1) a normative codestream syntax containing information for interpreting secure image data;
+- 2) informative examples of JPSEC tools in typical use cases;
+- 3) informative guidelines on how to implement security services and related metadata.
+
+The scope of this Recommendation | International Standard is not to describe specific secure imaging applications or to limit secure imaging to specific techniques, but to create a framework that enables future extensions as secure imaging techniques evolve.
+
+### 2 Normative references
+
+The following Recommendations and International Standards contain provisions which, through reference in this text, constitute provisions of this Recommendation | International Standard. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. At the time of publication, the editions indicated in dated references were valid. All Recommendations and Standards are subject to revision, and parties to agreements based on this Recommendation | International Standard are encouraged to investigate the possibility of applying the most recent edition of the Recommendations and Standards listed below. Members of IEC and ISO maintain registers of currently valid International Standards. The Telecommunication Standardization Bureau of the ITU maintains a list of currently valid ITU-T Recommendations.
+
+- Recommendation ITU-T T.800 | ISO/IEC 15444-1, *Information technology – JPEG 2000 image coding system: Core coding system*.
+- Recommendation ITU-T T.801 | ISO/IEC 15444-2, *Information technology – JPEG 2000 image coding system: Extensions*.
+- Recommendation ITU-T T.808 | ISO/IEC 15444-9, *Information technology – JPEG 2000 image coding system: Interactivity tools, APIs and protocols*.
+- Recommendation ITU-T T.814 | ISO/IEC 15444-15, *Information technology – JPEG 2000 image coding system: High-Throughput JPEG 2000*.
+- Recommendation ITU-T X.509 | ISO/IEC 9594-8, *Information technology – Open Systems Interconnection – The Directory: Public-key and attribute certificate frameworks*.
+- ISO/IEC 14496-12, *Information technology – Coding of audio-visual objects – Part 12: ISO base media file format*.
+
+### 3 Definitions
+
+For the purposes of this document, the definitions contained in Rec. ITU-T T.800 | ISO/IEC 15444-1, Rec. ITU-T T.801 | ISO/IEC 15444-2, Rec. ITU-T T.808 | ISO/IEC 15444-9, Rec. ITU-T T.814 | ISO/IEC 15444-15, and ISO/IEC 14496-12, and the following apply.
+
+**3.1 access control:** Prevention of unauthorized use of a resource, including the prevention of use of a resource in an unauthorized manner.
+
+**3.2 adaptive-format decoder:** Process to decode a codestream which is not fully compliant with the normative part of the coding standard.
+
+NOTE – It reconstructs the media (possibly with low quality or resolution) even if the codestream has missing packets or inconsistent packet headers. For example, an adaptive-format decoder is able to understand a simply transcoded codestream, such as the one that has its highest resolution packets removed.
+
+**3.3 adaptor/transcoder:** process to transform media data to lower scalability level, like lower resolution or lower quality or bit-rate, by removing portions of the file.
+
+NOTE – The adaptor/transcoder can transform media data based on the information specified in this Recommendation | International Standard. An adaptor/transcoder updates byte offset values in file format parameters that are impacted by the process.
+
+**3.3.1 authentication adaptor/transcoder:** Process to remove data that is not verifiable with the available media and authentication data.
+
+NOTE – For example, in a streaming system, some media packets can be lost during transmission. A file format receiver can reconstruct the received data to the best of its ability based on the available data. Then, an authentication adaptor/transcoder can determine which data can be verified, and then remove the packets that are not verified. The resulting file only contains the decodable, verified data.
+
+**3.3.2 JPEG 2000-aware adaptor/transcoder:** Process that combines one or more scalable composed ESs to form a fully decodable media codestream.
+
+**3.3.3 simple adaptor/transcoder:** Process to transform data based on information specified by this Recommendation | International Standard.
+
+NOTE – A simple adaptor/transcoder might not be capable of generating media headers or modifying packet indices. It simply retrieves data pointed by pointer structure and removes the wrappers, and the resulting codestream can be decoded by adaptive-format decoder, which can cope with missing packets and inconsistent headers.
+
+**3.4 authentication:** Process of verifying an identity claimed by or for a system entity.
+
+**3.4.1 source authentication:** Verification that a source entity (say, user/party) is in fact the claimed source entity.
+
+**3.5 ByteData:** Structure used to wrap a data segment which is physically located in a composed ES.
+
+NOTE – It is contained inside a container structure.
+
+**3.6 confidentiality:** Property that information is not made available or disclosed to unauthorized individuals, entities or processes.
+
+**3.7 container:** Container structure is used to wrap a sample in a composed ES.
+
+NOTE – It might contain any number of ByteData or pointer structures, but is not allowed to contain another container structure.
+
+**3.8 data splitting:** Method to protect sensitive data from unauthorized access by encrypting the data and storing different portions of the file on different servers.
+
+NOTE – When split data is accessed the parts are retrieved, combined and decrypted. An unauthorized person would need to know the locations of the servers containing the parts, be able to get access to each server, know what data to combine, and how to decrypt it.
+
+**3.9 decryption, deciphering:** Inverse transformation of the encryption.
+
+**3.10 digital signature:** Data appended to, or a cryptographic transformation of, a data unit that allows a recipient of the data unit to prove the source and integrity of the data unit and protect against forgery, e.g., by the recipient.
+
+**3.11 elementary stream (ES):** Contains a sequence of samples, where each sample could be a video frame or a contiguous section of audio data.
+
+NOTE – A sample in ES contains media data, ByteData structure, pointer structure, container structure, or any mixture of these.
+
+**3.11.1 self-contained ES:** ES that contains only media data, whose format is not defined in this Recommendation | International Standard.
+
+NOTE – The self-contained ES could be stored in MDAT box co-located with the file format specified in this Recommendation | International Standard, or be stored in a separate file whose format is not specified by this Recommendation | International Standard.
+
+**3.11.2 composed ES:** ES that can contain a mixture of ByteData, pointer and container structures, that is, its samples are composed with data from other elementary streams.
+
+NOTE – A composed ES can either copy (using ByteData structure) or reference (using pointer) data from other ESs.
+
+**3.11.3 scalable composed ES:** ES made up of samples that might not be decodable by themselves.
+
+NOTE – A scalable composed ES might need to be combined with other scalable composed ESs to form a fully decodable codestream. Scalable composed ES is designed to support scalability, i.e., to make media data "thinable". For example, for a Motion JPEG 2000 codestream where each picture has three layers, it can be divided into 3 scalable composed ESs: the first one consists of all layer 0 data, the second one consists of all layer 1 data and the third one consists of all layer 2 data.
+
+**3.11.4 decodable composed ES:** ES made up of samples that are decodable by themselves.
+
+NOTE – It is designed for simple adaptation where the adaptor just needs to retrieve data pointed by pointer structure and remove the wrapper to form a fully scalable codestream. For example, for a Motion JPEG 2000 codestream where each picture has three layers, it can form 3 decodable composed ESs: the first one consists of layer 0 data, the second one consists of layer 0 and layer 1 data and the third one consists of layer 0, 1 and 2 data.
+
+**3.12 encryption:** Reversible transformation of data by a cryptographic algorithm to produce ciphertext, i.e., to hide the information content of the data.
+
+NOTE – An alternative term for an encryption algorithm is cipher.
+
+**3.13 hash function:** Function which maps strings of bits to fixed-length strings of bits.
+
+NOTE 1 – This function satisfies the following two properties:
+
+- For a given output, it is computationally infeasible to find an input which maps to this output.
+- For a given input, it is computationally infeasible to find a second input which maps to the same output.
+
+NOTE 2 – Computational feasibility depends on the user's specific security requirements and environment.
+
+**3.14 integrity:** Property of being able to safeguard the accuracy and the completeness of assets.
+
+**3.14.1 image data integrity:** Property that data has not been altered or destroyed in an unauthorized manner.
+
+**3.14.2 image content integrity:** Assurance the image content has not been modified by unauthorized parties in such a way that its perceptual meaning is changed.
+
+NOTE – It allows the content-preserving operations to be performed on the image without triggering the integrity alarm.
+
+**3.15 JPSEC application:** Software or hardware process that is capable of consuming JPSEC codestreams by interpreting the JPSEC syntax in order to provide the specified security services.
+
+NOTE – A JPSEC application makes use of one or several JPSEC tools.
+
+EXAMPLE – A JPSEC application would be able to read encrypted JPSEC codestreams, decrypt them when provided with the appropriate key and render the JPEG 2000 original clear-text image data.
+
+**3.16 JPSEC codestream:** Sequence of bits resulting from coding and securing an image using JPEG 2000 coding and JPSEC security tools.
+
+**3.16.1 JPSEC creator:** Entity who creates a JPSEC codestream from an image, a JPEG 2000 codestream, or another JPSEC codestream in order to provide some JPSEC services.
+
+**3.16.2 JPSEC consumer:** Entity who receives a JPSEC codestream and renders a JPSEC service based on the codestream.
+
+**3.17 JPSEC service:** Service that provides security for consumption of JPEG 2000 images. The service counters security attacks and makes use of one or several JPSEC tools.
+
+**3.18 JPSEC tool:** Hardware or software process that uses security techniques to implement a security service.
+
+**3.18.1 JPSEC normative tool:** JPSEC tool that uses predefined tool templates for decryption, authentication, or hashing specified by the normative part of this Recommendation | International Standard.
+
+**3.18.2 JPSEC non-normative tool:** JPSEC tool that is specified by an identification number given by a user-defined application.
+
+NOTE – Examples of JPSEC non-normative tools are describe in Annex B.
+
+**3.18.3 JPSEC RA tool:** JPSEC non-normative tool that definition is registered by JPSEC registration authority (RA). (Deprecated)
+
+**3.18.4 JPSEC user-defined tool:** JPSEC non-normative tool that is defined by a user-defined application.
+
+**3.19 JPSEC tool description:** Description of the parameters used by the JPSEC tool.
+
+NOTE – JPSEC tool description does not describe the algorithm or method used. A JPSEC tool description consists of two parts: the parameter list and its values. In the case of JPSEC normative tools, the parameter list is given by the standard. In the case of JPSEC non-normative tools, the parameter list can be given by a user-defined application. In both cases, the parameter values are specified in the SEC and INSEC marker segments.
+
+**3.20 key:** Sequence of symbols that controls the operations of encipherment and decipherment.
+
+**3.20.1 asymmetric key pair:** Pair of related keys where the private key defines the private transformation, and the public key defines the public transformation.
+
+**3.20.1.1 private key:** Key of an entity's asymmetric key pair which is intended to remain private.
+
+**3.20.1.2 public key:** Key of an entity's asymmetric key pair which can be made public.
+
+**3.21 key generation, key generating function:** Function which takes as input a number of parameters, at least one of which is secret, and which gives as output keys appropriate for the intended algorithm and application.
+
+NOTE – The function has the property that it is computationally infeasible to deduce the output without prior knowledge of the secret input.
+
+**3.22 key management:** Generation, storage, distribution, deletion, archiving and application of keys in accordance with a security policy.
+
+**3.23 marker emulation:** Cipher text resulting from the encryption process that contains a JPEG start code.
+
+**3.24 message authentication code (MAC):** String of bits which is the output of a MAC algorithm.
+
+**3.25 non-repudiation:** Binding of an entity to a transaction in which it participates, so that the transaction cannot later be repudiated (denied).
+
+NOTE – That is, the receiver of a transaction is able to demonstrate to a neutral third party that the claimed sender did indeed send the transaction.
+
+**3.26 normal decoder:** Standard decoder is a process to decode a codestream that is fully compliant with the normative part of coding standard. Its behaviour is not defined if it tries to decode a non-compliant codestream.
+
+**3.27 packet:** Part of the JPEG 2000 Core coding system bit stream comprising a packet header and the compressed image data from one layer of the precinct of one resolution of one tile-component.
+
+NOTE – This is different from the term "packet" used in data transmission through network.
+
+**3.28 pointer:** Pointer structure is used to reference a data segment in another ES. It is contained inside a container structure.
+
+**3.29 protection:** Process to secure content.
+
+**3.29.1 protection template:** Template or list of parameter fields necessary for the operation of a protection method.
+
+**3.29.2 protection method:** Method used to create or consume protected content such as encryption, decryption, authentication, and integrity checking.
+
+**3.30 security:** All aspects related to defining, achieving, and maintaining confidentiality, integrity, availability, accountability, authenticity, and reliability.
+
+NOTE – A product, system, or service is considered to be secure to the extent that its users can rely on that it functions (or will function) in the intended way. This is usually considered in the context of an assessment of actual or perceived threats.
+
+**3.31 signalling syntax:** Specification of the format of the JPSEC codestream that contains all the required information for consuming secure JPEG 2000 images.
+
+**3.32 transcoding:** Operation of taking an input compressed codestream and adapting or converting it to produce an output compressed codestream that has some desired property.
+
+EXAMPLE – The output compressed codestream can represent an image with a lower spatial resolution or lower bit rate than the input compressed codestream.
+
+**3.32.1 secure transcoding:** Operation of performing transcoding, or adaptation, of a protected input compressed content, without unprotecting the content.
+
+NOTE – The term secure transcoding is used, as opposed to transcoding, to stress that the transcoding operation is performed without compromising security. Secure transcoding can also be referred to as performing transcoding in the encrypted domain.
+
+**3.33 watermark:** Signal imperceptibly added to the cover-signal in order to convey hidden data.
+
+**3.33.1 watermarking:** Process that imperceptibly inserts data representing some information into multimedia.
+
+NOTE – The multimedia data in one of the following two ways:
+
+- The lossy way which means the exact cover-signal will never be able to be recovered once the watermark is embedded.
+- The lossless way which means the exact cover-signal could be recovered after watermark extraction.
+
+**3.34 4CC Code:** 32-bit identifier, normally 4 printable characters.
+
+NOTE – This 4CC code can be used to indicate the file type, the type of file format box, type of a file format track, type of a file format sample description and type of file format track reference.
+
+## 4 Symbols and abbreviations
+
+For the purposes of this Recommendation | International Standard, the following abbreviations apply.
+
+|       |                                                 |
+|-------|-------------------------------------------------|
+| BAS   | Byte Aligned Segment                            |
+| FBAS  | Field Byte Aligned Segment                      |
+| G     | Granularity                                     |
+| GL    | Granularity Level                               |
+| ICV   | Integrity Check Value                           |
+| INSEC | In-codestream security marker                   |
+| IP    | Intellectual Property related to technology     |
+| IPR   | Intellectual Property Rights related to content |
+
+|       |                             |
+|-------|-----------------------------|
+| JPSEC | Secure JPEG 2000            |
+| KT    | Key Template                |
+| LSB   | Least Significant Bit       |
+| MAC   | Message Authentication Code |
+| MSB   | Most Significant Bit        |
+| PD    | Processing Domain           |
+| PKI   | Public Key Infrastructure   |
+| PO    | Processing Order            |
+| RBAS  | Range Byte Aligned Segment  |
+| SEC   | Security marker             |
+| T     | Template                    |
+| V     | Values                      |
+| VL    | Value List                  |
+| ZOI   | Zone of Influence           |
+
+## 5 JPSEC syntax
+
+### 5.1 JPSEC framework overview
+
+JPSEC defines a framework for the securing of JPEG 2000 coded data. The core of this Recommendation | International Standard is the specification of the syntax of the secure JPEG 2000 image, the *JPSEC codestream*. The syntax is targeted toward JPEG 2000 coded data and allows for protection of the entire codestream or of parts of the codestream. In all cases the protected data (i.e., the JPSEC codestream) shall follow the normative syntax defined in this Recommendation | International Standard.
+
+To the JPSEC codestream are associated a number of *JPSEC security services* including confidentiality and authentication of origin and of content.
+
+The *signalling syntax* specifies:
+
+- what security services are associated with the image data;
+- which *JPSEC tools* are required to deliver the corresponding services;
+- how the JPSEC tools are applied;
+- which parts of the image data are protected.
+
+#### Case A: Image
+
+![Diagram of Case A: Image. It shows a flow from left to right. On the left, 'Image' and 'Delivered service' have arrows pointing into a box labeled 'JPSEC creator'. An arrow points from the 'JPSEC creator' box to the text 'JPSEC codestream'. Another arrow points from 'JPSEC codestream' into a box labeled 'JPSEC consumer'. Finally, two arrows point from the 'JPSEC consumer' box to 'Image' and 'Delivered service' on the right.](29f586959675cafdf81cf934954908eb_img.jpg)
+
+Diagram of Case A: Image. It shows a flow from left to right. On the left, 'Image' and 'Delivered service' have arrows pointing into a box labeled 'JPSEC creator'. An arrow points from the 'JPSEC creator' box to the text 'JPSEC codestream'. Another arrow points from 'JPSEC codestream' into a box labeled 'JPSEC consumer'. Finally, two arrows point from the 'JPSEC consumer' box to 'Image' and 'Delivered service' on the right.
+
+#### Case B: JPEG 2000 codestream
+
+![Diagram of Case B: JPEG 2000 codestream. It shows a flow from left to right. On the left, 'JPEG 2000 codestream' and 'Delivered service' have arrows pointing into a box labeled 'JPSEC creator'. An arrow points from the 'JPSEC creator' box to the text 'JPSEC codestream'. Another arrow points from 'JPSEC codestream' into a box labeled 'JPSEC consumer'. Finally, two arrows point from the 'JPSEC consumer' box to 'JPEG 2000 codestream' and 'Delivered service' on the right.](b0d4609bc46c2d88a8318706bb5321f7_img.jpg)
+
+Diagram of Case B: JPEG 2000 codestream. It shows a flow from left to right. On the left, 'JPEG 2000 codestream' and 'Delivered service' have arrows pointing into a box labeled 'JPSEC creator'. An arrow points from the 'JPSEC creator' box to the text 'JPSEC codestream'. Another arrow points from 'JPSEC codestream' into a box labeled 'JPSEC consumer'. Finally, two arrows point from the 'JPSEC consumer' box to 'JPEG 2000 codestream' and 'Delivered service' on the right.
+
+#### Case C: JPSEC codestream
+
+![Diagram of Case C: JPSEC codestream. It shows a flow from left to right. On the left, 'JPSEC codestream' and 'Delivered service' have arrows pointing into a box labeled 'JPSEC creator'. An arrow points from the 'JPSEC creator' box to the text 'JPSEC codestream'. Another arrow points from 'JPSEC codestream' into a box labeled 'JPSEC consumer'. Finally, two arrows point from the 'JPSEC consumer' box to 'JPSEC codestream' and 'Delivered service' on the right.](6f659142d4789aa889184459f884787e_img.jpg)
+
+Diagram of Case C: JPSEC codestream. It shows a flow from left to right. On the left, 'JPSEC codestream' and 'Delivered service' have arrows pointing into a box labeled 'JPSEC creator'. An arrow points from the 'JPSEC creator' box to the text 'JPSEC codestream'. Another arrow points from 'JPSEC codestream' into a box labeled 'JPSEC consumer'. Finally, two arrows point from the 'JPSEC consumer' box to 'JPSEC codestream' and 'Delivered service' on the right.
+
+T.807(23)\_F01
+
+Figure 1 – Overview of the conceptual steps in JPSEC framework
+
+The syntax of the JPSEC codestream is normative. The purpose is to allow JPSEC applications to consume JPSEC codestreams in an interoperable way (see Figure 1). The JPSEC consumer application interprets the JPSEC codestream, identifies and applies the signalled JPSEC tools, delivers the corresponding security services and then passes on the output JPEG 2000 codestream or image for subsequent processing, for example by an image viewer.
+
+As shown in case C of Figure , the JPSEC codestream can be created from another JPSEC codestream. This can arise when multiple JPSEC tools are applied to the same content, but at different times or by different entities. When this occurs, the ordering in which the JPSEC tools are applied during the creation and consumption operations can be significant.
+
+The signalling syntax identifies tools that are used by a JPSEC consumer. Tools are either defined by the normative part of the standard, or by private tools. The normatively defined tools support confidentiality (through encryption tools), and authentication of the source and of the content. They allow for the highest type of interoperability since independent implementations of the consuming process are able to process the same JPSEC codestream and render the corresponding services with the same behaviour.
+
+The way in which the JPSEC codestream is created is out of scope of this Recommendation | International Standard. To be compliant, JPSEC creators shall generate JPSEC codestreams that include the appropriate JPSEC signalling. JPSEC codestreams can be created in a number of ways. For example, a JPSEC tool can be applied to image pixels or it can be applied on wavelet coefficients, or on quantized coefficients, or on packets.
+
+A consumer can implement one or more JPSEC tools. For example, it could be capable of performing decryption using AES block cipher in ECB mode and signature verification using SHA-128 hash and an RSA public key. With these capabilities, it would be capable of performing the security services of confidentiality and authentication.
+
+In the JPSEC framework, JPSEC tools are specified by templates, defined privately. JPSEC tools specified by the templates have unique processing behaviour and therefore do not require unique identification. Those tools are associated with a unique identification number provided by the common registry.
+
+The guideline and use cases of JPSEC are described in Annex A, and the file format security is described in Annex D. The interoperability of JPEG 2000 family, e.g., JPX, JPIP and JPWL, are described in Annex C.
+
+## **5.2 JPSEC security services**
+
+The objective in this clause is to list and to explain the functionalities that are included in the scope of this Recommendation | International Standard.
+
+JPSEC tools are used to implement security functions. JPSEC is an open framework, which means that it is extensible in the future. Currently it focuses on the following aspects:
+
+- Confidentiality via encryption and selective encryption
+
+A JPSEC file can support a transformation of the (image and/or metadata) data (plaintext) into a form (cipher text) that conceals the data's original meaning. Selective encryption means that not the entire image and/or metadata but only parts of the image and/or metadata can be encrypted.
+
+- Integrity verification
+
+A JPSEC file can support means of detecting manipulations to the image and/or metadata and thereby verify their integrity. There are two classes of integrity verification:
+
+- 1) Image data integrity verification where even only one bit of image data in error results in verification failure (i.e., the verification returns "no integrity"). This verification is also often referred to as fragile image (integrity) verification.
+- 2) Image content integrity verification where even some incidental alteration of image data results in verification success as long as the alteration does not change image content from the human visual system point of view; in other words, the image perceptual meaning does not change. This verification is also often referred to as semi-fragile image (integrity) verification.
+
+Those fragile or semi-fragile image integrity verifications might identify locations in the image data/image content where the integrity is put into question. Solutions can include:
+
+- 1) Cryptographic methods such as Message Authentication Codes (MAC), digital signatures, cryptographic checksums or keyed hash.
+- 2) Watermarking-based methods. This Recommendation | International Standard does not define normative template for watermarking technology, although it supports non-normative tools using watermarking technology.
+- 3) Combination of the above two types of methods.
+
+- Source authentication  
+A JPSEC file can support a verification of the identity of a user/party which generated the JPSEC file. This can comprise methods of e.g., digital signatures or message authentication code (MAC).
+- Conditional access  
+A JPSEC file can support a mechanism and policy to grant or restrict access to image data or portions of those. This could allow for instance to view a low resolution (preview) of an image without being able to visualize a higher resolution.
+- Registered Content identification  
+A JPSEC file can be registered at a Content Registration Authority. It can support a method of matching the (claimed) image data/image content to the registered image data/image content. For example, such a method could be: Reading a file identifier (Licence Plate) which was placed inside the metadata, checking the coherence between this Licence Plate and the information that has been uploaded when the registration process was done. The Licence Plate might contain enough information to be able to request information from the Content Registration Authority where the file was registered and verify that the file corresponds to the identifier.
+- Secure scalable streaming and secure transcoding  
+A JPSEC file or sequence of packets can support methods such that the same or different nodes can perform streaming and transcoding without requiring decryption or unprotecting the content. An example is the case where protected JPEG 2000 content is streamed to a mid-network node or proxy that in turn transcodes the protected JPEG 2000 content in a manner that preserves end-to-end security.
+
+### 5.3 Comments on design and implementation of secure JPSEC systems
+
+This Recommendation | International Standard supports a rich and flexible set of security services. For example, the encryption primitives can be applied in a variety of different ways to achieve different goals, ranging from encryption of the entire JPEG 2000 codestream to selective encryption of only a small portion of the codestream. However, it is important to stress that significant care needs to be taken when implementing any security system, including one based on JPSEC.
+
+It is strongly recommended that the designers of any security system carefully consider the recommended guidelines (Annex A) for the security primitives that are being employed. For most of the security primitives signalled using JPSEC, the associated ISO/IEC standards provide important guidance on their correct use. For example, for encryption using a block cipher and an associated block cipher mode (Table 29 ), guidelines for block cipher mode choice and operation are given in ISO/IEC 10116.
+
+In addition, in many security applications authentication is the most important security service. Even when confidentiality is the targeted security service, it should be augmented by authentication to prevent various forms of attacks. Specifically, even in many imaging applications where the primary goal is confidentiality, it is recommended that authentication also be employed.
+
+Key management is outside the scope of JPSEC. However, its criticality needs to be stressed. Of paramount importance in any cryptographic system is the management of the cryptographic keys that control the operations. If these keys are compromised, then the security of the whole system is compromised and in such a way that the compromise is not necessarily detected. It is therefore imperative that the keys are generated, distributed, stored and destroyed at a security level that is at least equal to that of the data that it is protecting. Furthermore, since the chances a key is compromised increase over time, it is also imperative that keys only be used for a fixed key lifetime. For more information on the use and management of cryptographic keys, see ISO/IEC 11770.
+
+As with all security systems, the use of cryptographic operations are completely opaque to the user. That is, the user should not be able to discover any information about the cryptographic operations except for the output. For example, the user should not be able to access information about why a cryptographic operation failed to produce an output. Similarly, a user should not be able to find out any extra information even if he/she resorts to measuring "side channels" such as timing and/or power analysis. In short, the user should not be able to notice any difference in any of the applications outputs, regardless of what the application is currently doing, for if this is not the case the resulting leakage of information can potentially compromise the security of the system.
+
+To summarize, it is strongly recommended that the designer of any security system, including one based on JPSEC, pay special attention to the details of the system design to ensure a secure system.
+
+## 5.4 Byte aligned segment (BAS)
+
+### 5.4.1 Byte aligned segment
+
+In order to provide extensible signalling for classes and modes, this Recommendation | International Standard uses a variable length data structure called a "byte aligned segment" (BAS). Parameter fields with an extensible number of fields are represented with the Field BAS (FBAS) structure. Parameter values with large ranges are represented extensively with the Range BAS (RBAS) structure.
+
+As illustrated in Figure 2, the BAS is composed of a sequence of one or more BAS bytes. The most significant bit (MSB) of each BAS byte indicates the existence of a following BAS byte. Specifically, if MSB = 1 then a subsequent BAS byte follows, while if MSB = 0 then a subsequent BAS byte does not exist, and the BAS structure is terminated. The remaining least significant bits of each BAS byte are concatenated to form a list of bits which are used in different ways for different BAS parameters. Often, they are used in conjunction with a parameter list that has a number of elements, and each BAS bit is set to 1 or 0 to flag information about its corresponding element. This flexible structure was chosen because of its extensibility for future evolutions of the standard, since it allows new parameters to be signalled in an extensible way.
+
+![](3da1a07cb87051bf616c9876db958cf0_img.jpg)
+
+| MSB |   |   |   |   |   |   |   |
+|-----|---|---|---|---|---|---|---|
+| 7   | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
+| 1   | X | X | X | X | X | X | X |
+
+...
+
+|   |   |   |   |   |   |   |   |
+|---|---|---|---|---|---|---|---|
+|   |   |   |   |   |   |   |   |
+| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
+| 1 | X | X | X | X | X | X | X |
+
+| LSB |   |   |   |   |   |   |   |
+|-----|---|---|---|---|---|---|---|
+| 7   | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
+| 0   | X | X | X | X | X | X | X |
+
+T.807(23)\_F02
+
+**Figure 2 – Byte aligned segment (BAS) structure**
+
+### 5.4.2 Field BAS (FBAS)
+
+A Field BAS (FBAS) is a type of BAS where the remaining bits of the BAS bytes are used to set fields to 1 or 0. An example of FBAS usage is the description class of the zone of influence (DCzoi), where multiple image descriptions such as tile index, resolution level, and colour component can be specified. If this is done, the three BAS bits corresponding to tile, resolution, and colour would be flagged to 1.
+
+For example, to represent a Field BAS with 9 fields, f1 through f9, at most two BAS bytes would be needed. If the two bytes were byte "a" and byte "b", and the most significant bit of each byte were a0 and b0, then the FBAS would look like:
+
+a0 a1 a2 a3 a4 a5 a6 a7 | b0 b1 b2 b3 b4 b5 b6 b7
+
+a0 and b0 are the indicator bits. Field f1 through f7 are represented in bits a1 through a7, and field f8 is in bit b1 and field f9 is in bit b2. The remaining bits b3 through b7 are reserved and set to 0.
+
+a0 f1 f2 f3 f4 f5 f6 f7 | b0 f8 f9 0 0 0 0 0
+
+When used in a JPSEC stream, the FBAS in this example can be represented with one or two bytes, depending on the actual values of the field. This stems from the fact that the default value of the fields is 0. Thus, if fields f8 and f9 are not set (i.e., their value is 0), then the second byte of the BAS is not needed, and a0 is set to 0. On the other hand, if field 8 or field 9 is set, then two bytes are needed. In this case, a0 is set to 1 and b0 is set to 0.
+
+Notice that the field bits are "left aligned". This allows us to add more fields over time in a compatible manner.
+
+### 5.4.3 Range BAS (RBAS)
+
+The Range BAS (RBAS) is used to extend the range or the number of bits used to represent a value. There are two types of RBAS, RBAS-8 and RBAS-16.
+
+The RBAS-8 contains one or more RBAS bytes that contain the bits of the value. As in the FBAS, the first bit of each byte indicates whether another RBAS byte follows.
+
+Unlike the FBAS, the RBAS is "right aligned". Thus, if a value has 9 significant bits v1 through v9, where v1 is the most significant bit, then it would be represented with two BAS bytes:
+
+a0 a1 a2 a3 a4 a5 a6 a7 | b0 b1 b2 b3 b4 b5 b6 b7
+
+as follows:
+
+1 0 0 0 0 0 v1 v2 | 0 v3 v4 v5 v6 v7 v8 v9
+
+If the value was small such that bits v1 and v2 were zero, then the two-byte representation above could be used with v1 and v2 set to zero, or a one-byte RBAS could be used as follows:
+
+0 v3 v4 v5 v6 v7 v8 v9
+
+The RBAS-16 can be used to represent values that are typically more than 7 bits but less than 15. In this case, the first RBAS chunk is two bytes where the first bit is the indicator and then next 15 bits are value bits, then the remaining bytes extended one byte at a time using the typical BAS structure where the first bit of each byte is the indicator of following BAS bytes.
+
+a0 a1 a2 a3 a4 a5 a6 a7 | b0 b1 b2 b3 b4 b5 b6 b7 | c0 c1 c2 c3 c4 c5 c6 c7
+
+If a parameter value had 22 bits, then it could be represented with the three-byte RBAS-16 structure shown below, where a0 and c0 are indicator bits to specify whether a BAS byte follows. Any remaining BAS bytes are traditional one-byte BAS segments.
+
+a0 v1 v2 v3 v4 v5 v6 v7 | v8 v9 v10 v11 v12 v13 v14 v15 | c0 v16 v17 v18 v19 v20 v21 v22
+
+Thus, the indicator bits would be set as follows:
+
+1 v1 v2 v3 v4 v5 v6 v7 | v8 v9 v10 v11 v12 v13 v14 v15 | 0 v16 v17 v18 v19 v20 v21 v22
+
+For both the RBAS-8 and RBAS-16, the value bits are also "right aligned".
+
+Note that when writing JPSEC creators and consumers, it is important to pay attention to the big endian/little endian representations.
+
+### 5.5 Main security marker (SEC)
+
+#### 5.5.1 Security marker segments
+
+In this clause, a simple and flexible, yet powerful syntax for JPSEC signalling is presented. SEC marker segments are defined for this purpose and are located in the main header. The SEC marker segment syntax allows for the description of all required information for securing JPEG 2000 images. To do so, it makes references to JPSEC normative tools that are specified by the templates described in 5.8 or by JPSEC non-normative tools that can be defined *a priori* privately, and it makes provisions for handling parameters related to these tools.
+
+A JPSEC codestream can be protected with one or more JPSEC tools. Each tool is a JPSEC normative tool or a JPSEC non-normative tool. The parameters for these tools are signalled in one or more SEC marker segments located in the main header of the codestream after the SIZ marker segment. When multiple SEC marker segments are used, they are concatenated and shall appear consecutively in the main header. In most cases, all the JPSEC parameters can be signalled in one SEC marker segment. However, in some cases the length of the signalling can exceed the maximum marker segment size. When this occurs, additional SEC marker segments can be used for signalling.
+
+Figure 3 shows the syntax of the SEC marker segment. The segment is signalled by the SEC marker 0xFF65. L<sub>SEC</sub> is the length of the SEC marker segment, including the 2 bytes for L<sub>SEC</sub>, but not the two bytes for the SEC marker itself. Z<sub>SEC</sub> is a SEC marker segment index. Z<sub>SEC</sub> shall be set to 0 for the first marker segment that appears in the codestream. P<sub>SEC</sub> is a parameter field that describes the security parameters relevant to the entire codestream and only exists in the first SEC marker segment, i.e., if Z<sub>SEC</sub> = 0. The syntax supports the use of several JPSEC tools that are signalled in one or more marker segments. If more than one JPSEC tool is used, then a JPSEC consumer shall process the tools in the order in which they appear in the codestream.
+
+![Figure 3: Main security marker segment syntax diagram. The diagram shows a sequence of fields: SEC, L_SEC, Z_SEC, P_SEC, Tool^(1), and Tool^(1). The fields Z_SEC, P_SEC, and Tool^(1) are shaded with diagonal lines. The field Tool^(1) is followed by a vertical bar and another Tool^(1) field. Below the diagram is the label T.807(23)_F03.](c42e926097d01653b793c04b49e764b2_img.jpg)
+
+Figure 3: Main security marker segment syntax diagram. The diagram shows a sequence of fields: SEC, L\_SEC, Z\_SEC, P\_SEC, Tool^(1), and Tool^(1). The fields Z\_SEC, P\_SEC, and Tool^(1) are shaded with diagonal lines. The field Tool^(1) is followed by a vertical bar and another Tool^(1) field. Below the diagram is the label T.807(23)\_F03.
+
+Figure 3 – Main security marker segment syntax
+
+- SEC:** Marker code. Table 1 shows the sizes and values of the symbols and parameters for the main security marker segment.
+- L<sub>SEC</sub>:** Length of marker segment in bytes (including L<sub>SEC</sub> itself, but excluding the marker).
+- Z<sub>SEC</sub>:** Index of this marker segment relative to all other SEC marker segments present in the current header. This field uses the RBAS structure.
+- P<sub>SEC</sub>:** Parameter field for codestream security parameters. This field is only present in the first SEC marker segment, i.e., when Z<sub>SEC</sub> is 0.
+- Tool<sup>(i)</sup>:** Parameters for JPSEC tool *i*. If multiple JPSEC tools are signalled, then a JPSEC consumer shall process each tool in the order of appearance in the JPSEC codestream.
+
+Table 1 – Main security parameter values
+
+| Parameter           | Size (bits)                                       | Values                               |
+|---------------------|---------------------------------------------------|--------------------------------------|
+| SEC                 | 16                                                | 0xFF65                               |
+| L <sub>SEC</sub>    | 16                                                | 2 ... (2 <sup>16</sup> – 1)          |
+| Z <sub>SEC</sub>    | 8 + 8 * n (RBAS)                                  | 0 ... 2 <sup>7+7*n</sup>             |
+| P <sub>SEC</sub>    | 0, if Z <sub>SEC</sub> > 0<br>Variable, otherwise | If Z <sub>SEC</sub> = 0, see Table 2 |
+| Tool <sup>(i)</sup> | Variable                                          | See 5.6.2 and 5.6.3                  |
+
+Figure 4 shows the syntax of the security parameters in the main header when multiple SEC marker segments are used. In this case, the JPSEC tool parameters are in different SEC marker segments. Each marker segment begins with the SEC marker, 0xFF65, and is followed by the length and index of the marker segment. The index of the first marker segment shall be set to 0 and shall increase by one for each marker segment in the order it appears. Only the first marker segment contains the security parameters for the codestream, P<sub>SEC</sub>. All the marker segments contain the parameters for one or more JPSEC tools.
+
+![Diagram showing the syntax of multiple SEC marker segments. Each segment contains SEC, L_SEC, Z_SEC, and Tool parameters. The first segment contains P_SEC. The diagram shows three segments: Segment 1 (SEC, L_SEC^(1), Z_SEC^(1), P_SEC, Tool^(1), Tool^(j)), Segment 2 (SEC, L_SEC^(2), Z_SEC^(2), Tool^(j+1), Tool^(k)), and Segment m (SEC, L_SEC^(m), Z_SEC^(m), Tool^(p+1), Tool^(n)).](7d3d5fb5d09c0cd35a9d637be241651e_img.jpg)
+
+The diagram illustrates the syntax of multiple SEC marker segments. It shows three segments, each starting with the SEC marker (0xFF65), followed by the length L<sub>SEC</sub><sup>(i)</sup> and the index Z<sub>SEC</sub><sup>(i)</sup>. The first segment (i=1) also contains the security parameters P<sub>SEC</sub> and JPSEC tool parameters Tool<sup>(1)</sup> and Tool<sup>(j)</sup>. Subsequent segments (i=2, ..., m) contain JPSEC tool parameters Tool<sup>(j+1)</sup> and Tool<sup>(k)</sup>, ..., Tool<sup>(p+1)</sup> and Tool<sup>(n)</sup>. The diagram is labeled T.807(23)\_F04.
+
+Diagram showing the syntax of multiple SEC marker segments. Each segment contains SEC, L\_SEC, Z\_SEC, and Tool parameters. The first segment contains P\_SEC. The diagram shows three segments: Segment 1 (SEC, L\_SEC^(1), Z\_SEC^(1), P\_SEC, Tool^(1), Tool^(j)), Segment 2 (SEC, L\_SEC^(2), Z\_SEC^(2), Tool^(j+1), Tool^(k)), and Segment m (SEC, L\_SEC^(m), Z\_SEC^(m), Tool^(p+1), Tool^(n)).
+
+Figure 4 – Main security marker syntax when multiple marker segments are used
+
+If needed, a JPSEC tool description can span multiple SEC marker segments, e.g., this can occur if the length exceeds the maximum SEC marker size. Since the length of the tool description is completely specified, the JPSEC creator simply splits the tool across SEC marker segments. The decoder should then concatenate all segments, minus the SEC marker and the L<sub>SEC</sub> and Z<sub>SEC</sub> values, and then interpret the tools accordingly.
+
+P<sub>SEC</sub> is a parameter field that describes security parameters for the entire codestream as opposed to for a particular tool. This is used to indicate events such as JPEG 2000 Core coding system compliance or the use of INSEC markers. The P<sub>SEC</sub> parameters are shown in Figure 5.
+
+![Diagram showing the syntax of the P_SEC parameter field. It contains F_PSEC, N_tools, I_max, and P_TRLCP.](627c5195eaae3bc7e34cbc4dbdb6f9a8_img.jpg)
+
+The diagram shows the syntax of the P<sub>SEC</sub> parameter field. It consists of four fields: F<sub>PSEC</sub>, N<sub>tools</sub>, I<sub>max</sub>, and P<sub>TRLCP</sub>. The diagram is labeled T.807(23)\_F05.
+
+Diagram showing the syntax of the P\_SEC parameter field. It contains F\_PSEC, N\_tools, I\_max, and P\_TRLCP.
+
+Figure 5 – Codestream security parameters (P<sub>SEC</sub>) syntax
+
+- F<sub>PSEC</sub>**: Flag to indicate if INSEC marker segment is used, if multiple SEC marker segments are used, if the original JPEG 2000 Core coding system codestream data was modified, and if TRLCP tag usage is defined. FBAS structure is used by this field.
+- N<sub>tools</sub>**: Number of JPSEC tools used in the codestream. This field uses the RBAS structure.
+- I<sub>max</sub>**: Maximum tool instance index value used in the codestream. This field uses the RBAS structure.
+- P<sub>TRLCP</sub>**: Parameter field to define the format of TRLCP tag. This field exists if F<sub>TRLCP</sub> = 1.
+
+Table 2 – Codestream security parameters (P<sub>SEC</sub>) in first SEC marker segment
+
+| Parameter          | Size (bits)                                                   | Values                   |
+|--------------------|---------------------------------------------------------------|--------------------------|
+| F <sub>PSEC</sub>  | Variable (FBAS)                                               | See Table 3              |
+| N <sub>tools</sub> | 8 + n * 8 (RBAS)                                              | 1 ... 2 <sup>7+7*n</sup> |
+| I <sub>max</sub>   | 8 + n * 8 (RBAS)                                              | 0 ... 2 <sup>7+7*n</sup> |
+| P <sub>TRLCP</sub> | 0, if F <sub>TRLCP</sub> = 0<br>32, if F <sub>TRLCP</sub> = 1 | See Table 4              |
+
+F<sub>PSEC</sub> is an FBAS structure used to indicate a number of parameter flags about the JPSEC codestream. The fields represented by F<sub>PSEC</sub> are shown in Table 3. F<sub>INSEC</sub> shall be set to 1 if INSEC markers are used in the JPSEC codestream. F<sub>multiSEC</sub> shall be set to 1 if multiple SEC marker segments are used in the JPSEC codestream. F<sub>mod</sub> shall be set to 1 if the original JPEG 2000 data was modified in the JPSEC codestream. Note that if INSEC markers are used, then the original JPEG 2000 data is modified and thus F<sub>INSEC</sub> and F<sub>mod</sub> shall be set to 1. F<sub>TRLCP</sub> shall be set to 1 if the TRLCP tag usage is defined in P<sub>SEC</sub>. If it is defined, then the TRLCP tag descriptor, P<sub>TRLCP</sub>, is specified in the P<sub>SEC</sub> parameter field. The TRLCP tag usage shall be specified if any tool within the JPSEC codestream uses TRLCP tags.
+
+Table 3 – Semantics for F<sub>PSEC</sub> values (FBAS)
+
+| BAS field             | BAS bit number | Value (bits) | Semantics                                          |
+|-----------------------|----------------|--------------|----------------------------------------------------|
+| F <sub>INSEC</sub>    | 1              | 0            | INSEC is not used                                  |
+|                       |                | 1            | INSEC is used                                      |
+| F <sub>multiSEC</sub> | 2              | 0            | One SEC marker segment is used                     |
+|                       |                | 1            | Multiple SEC marker segments are used              |
+| F <sub>mod</sub>      | 3              | 1            | Original JPEG 2000 data was modified               |
+|                       |                | 0            | Otherwise                                          |
+| F <sub>TRLCP</sub>    | 4              | 0            | TRLCP tag usage is not defined in P <sub>SEC</sub> |
+|                       |                | 1            | TRLCP tag usage is defined in P <sub>SEC</sub>     |
+
+JPSEC defines a structure called a TRLCP tag that can be used to uniquely identify a JPEG 2000 packet. A JPEG 2000 packet can be uniquely specified by its tile index, resolution level index, layer index, component index, and precinct index. A TRLCP tag is defined as a data unit with a fixed number of bits used to specify each of these index values. The number of bits for each index is set in P<sub>SEC</sub>. P<sub>TRLCP</sub> is a parameter field that describes the format of the TRLCP tag as it shall be used in the JPSEC tools. This field only exists if F<sub>TRLCP</sub> = 1. P<sub>TRLCP</sub> consists of the following variables in Figure 6.
+
+![](6f31cdb576d2f15c35c3f266e5f59211_img.jpg)
+
+|                |   |   |   |   |   |   |   |                |   |   |   |                |   |   |   |                |   |   |   |                |   |   |   |   |   |   |   |         |   |   |   |   |
+|----------------|---|---|---|---|---|---|---|----------------|---|---|---|----------------|---|---|---|----------------|---|---|---|----------------|---|---|---|---|---|---|---|---------|---|---|---|---|
+| 7              | 6 | 5 | 4 | 3 | 2 | 1 | 0 | 3              | 2 | 1 | 0 | 4              | 3 | 2 | 1 | 0              | 4 | 3 | 2 | 1              | 0 | 7 | 6 | 5 | 4 | 3 | 2 | 1       | 0 | 1 | 0 |   |
+| b <sub>T</sub> |   |   |   |   |   |   |   | b <sub>R</sub> |   |   |   | b <sub>L</sub> |   |   |   | b <sub>C</sub> |   |   |   | b <sub>P</sub> |   |   |   |   |   |   |   | Padding |   |   |   |   |
+|                |   |   |   |   |   |   |   |                |   |   |   |                |   |   |   |                |   |   |   |                |   |   |   |   |   |   |   |         |   |   |   | 0 |
+
+T.807(23)\_F06
+
+Figure 6 – TRLCP tag descriptor (P<sub>TRLCP</sub>) syntax
+
+- b<sub>T</sub>**: Number of bits to represent tile index is b<sub>T</sub> + 1 in TRLCP tag.
+- b<sub>R</sub>**: Number of bits to represent resolution level index is b<sub>R</sub> + 1 in TRLCP tag.
+- b<sub>L</sub>**: Number of bits to represent layer index is b<sub>L</sub> + 1 in TRLCP tag.
+- b<sub>C</sub>**: Number of bits to represent component index is b<sub>C</sub> + 1 in TRLCP tag.
+- b<sub>P</sub>**: Number of bits to represent precinct index is b<sub>P</sub> + 1 in TRLCP tag.
+
+Table 4 – Parameter field for TRLCP tag descriptor ( $P_{\text{TRLCP}}$ )
+
+| Parameter | Size (bits) | Values            |
+|-----------|-------------|-------------------|
+| $b_T$     | 8           | 0 ... $(2^8 - 1)$ |
+| $b_R$     | 4           | 0 ... 15          |
+| $b_L$     | 5           | 0 ... 31          |
+| $b_C$     | 5           | 0 ... 31          |
+| $b_P$     | 8           | 0 ... $(2^8 - 1)$ |
+| Padding   | 2           | 0                 |
+
+The size of each resulting TRLCP tag is the smallest integer byte size that contains all the bits. The format of the TRLCP tag contains the bits for the tile index, the resolution level index, the layer index, the component index, and the precinct index in that order. If extra bits are needed to fill the integer byte size requirement, then the TRLCP tag will be placed in the least significant bits possible, and the extra bits are set to 0. Note that these extra bits will be the MSBs of the TRLCP tag if they exist.
+
+5.5.2 Application of multiple JPSEC tools
+
+In many applications multiple JPSEC tools apply to a single JPEG 2000 codestream. For example, both encryption and authentication can be applied to protect a JPEG 2000 image. The general situation of applying multiple JPSEC tools is illustrated in Figures 3, 4 and 7, where N tools are applied. The JPSEC consumer will read the N tools in order of placement in the SEC marker segment shown in Figure 3 or Figure 4, and apply them in that same order to perform the JPSEC consumption of the JPSEC codestream. Note that while the JPSEC consumer applies the JPSEC tools in order 1, 2, ..., N, as read from the SEC marker segment, during creation of the JPSEC codestream these JPSEC tools were applied in the reverse order, i.e., N, N – 1, ..., 2, 1, as illustrated in Figure 7. Note that the numbering of the tools in the figure was chosen to highlight that the JPSEC consumer applies the JPSEC tools in the reverse order from the JPSEC creator. However, any numbering of the JPSEC tools is acceptable, as long as each JPSEC tool in a JPSEC codestream is given a unique number for identification purposes.
+
+Generally speaking, JPSEC tools are created and consumed in reverse order of one another. For example, if the JPSEC creator applies N JPSEC tools, then the JPSEC consumer typically applies the same N JPSEC tools but in the reverse order. Correct JPSEC consumption of multiple JPSEC tools can be guaranteed by sequential consumption of the N tools in the correct order and by requiring any intermediate stage at the consumer to match the corresponding state at the creator. For example, in Figure 7, the state at the consumer after JPSEC consumption of tool 1 should be equal to the state after applying tool 2 during the JPSEC creation process. As a specific example of the state, the byte ranges should be consistent, therefore any bytes added when applying tool 1 should be removed when removing tool 1 at the JPSEC consumer.
+
+In certain applications, it can be desirable for a JPSEC consumer to consume the multiple JPSEC tools in a different manner than described above. For example, the JPSEC consumer can choose to consume the multiple tools in a different order, or to skip certain tools in the consumption. Furthermore, the JPSEC consumer can prefer to apply certain JPSEC tools, but not remove them, e.g., to check a digital signature but not remove it. Careful consideration should be given in these cases to ensure that the out-of-order or skipped processing does not lead to incorrect or unintended consequences. This behaviour is not recommended unless the JPSEC application is fully aware of the potential ramifications.
+
+![Diagram illustrating the use of multiple JPSEC tools. It shows two parallel processes: JPSEC creation on the left and JPSEC consumption on the right, separated by a dashed vertical line. In the creation process, a JPEG-2000 bitstream is input to Tool N, which then feeds into Tool 2, and finally Tool 1. The output of Tool 1 is the JPSEC bitstream. The state after applying Tool 2 is noted. In the consumption process, the JPSEC bitstream is input to Tool 1, which feeds into Tool 2, and finally Tool N. The output of Tool N is the JPEG-2000 bitstream. The state before consumption of Tool 2 is noted. A cloud icon represents the JPSEC bitstream being shared between the two processes. The diagram is labeled T.807(23)_F07.](19a5f0db57a21a0e82a7f326083e96fd_img.jpg)
+
+The diagram illustrates the use of multiple JPSEC tools in two parallel processes: JPSEC creation and JPSEC consumption, separated by a dashed vertical line. In the JPSEC creation process (left side), a JPEG-2000 bitstream is input to Tool N. Tool N feeds into Tool 2, which in turn feeds into Tool 1. The output of Tool 1 is the JPSEC bitstream. The state after applying Tool 2 is noted. In the JPSEC consumption process (right side), the JPSEC bitstream is input to Tool 1, which feeds into Tool 2, and finally Tool N. The output of Tool N is the JPEG-2000 bitstream. The state before consumption of Tool 2 is noted. A cloud icon represents the JPSEC bitstream being shared between the two processes. The diagram is labeled T.807(23)\_F07.
+
+Diagram illustrating the use of multiple JPSEC tools. It shows two parallel processes: JPSEC creation on the left and JPSEC consumption on the right, separated by a dashed vertical line. In the creation process, a JPEG-2000 bitstream is input to Tool N, which then feeds into Tool 2, and finally Tool 1. The output of Tool 1 is the JPSEC bitstream. The state after applying Tool 2 is noted. In the consumption process, the JPSEC bitstream is input to Tool 1, which feeds into Tool 2, and finally Tool N. The output of Tool N is the JPEG-2000 bitstream. The state before consumption of Tool 2 is noted. A cloud icon represents the JPSEC bitstream being shared between the two processes. The diagram is labeled T.807(23)\_F07.
+
+Figure 7 – Use of multiple JPSEC tools
+
+5.6 JPSEC tools
+
+5.6.1 JPSEC tool syntax
+
+As mentioned earlier, there are two types of JPSEC tools. JPSEC normative tools are specified with the protection method templates described in 5.8, and are also known as JPSEC normative tools. JPSEC non-normative tools are specified by a particular JPSEC application based on their ID number, and are respectively referred to as JPSEC user-defined tools. The syntax for JPSEC normative tools are discussed in 5.6.2. The syntax for JPSEC non-normative tools are discussed in 5.6.3.
+
+The syntax for JPSEC tools is shown in Figure 8. The JPSEC tool syntax has three main parts that describe:
+
+- 1) what tool is applied with its identification;
+- 2) where the tool is applied with a zone of influence structure; and
+- 3) how the tool is applied with a more detailed parameter field.
+
+For example, using this syntax, a JPSEC tool syntax could specify that a decryption tool should be used (what) on the lowest resolution component located in a particular byte range (where) using AES decryption in CBC mode with a specified set of initialization vectors and keys (how).
+
+![Figure 8: JPSEC tool syntax (Tool(i)). The diagram shows a sequence of fields: T_type, T_idx, ID, L_ZOI, ZOI, L_PID, and P_ID. Each field is represented by a rectangle with diagonal hatching. Below the rectangles, the text 'T.807(23). F08' is visible.](8d325fc12b494e42c9ea7ed2a7f327a6_img.jpg)
+
+Figure 8: JPSEC tool syntax (Tool(i)). The diagram shows a sequence of fields: T\_type, T\_idx, ID, L\_ZOI, ZOI, L\_PID, and P\_ID. Each field is represented by a rectangle with diagonal hatching. Below the rectangles, the text 'T.807(23). F08' is visible.
+
+Figure 8 – JPSEC tool syntax (Tool<sup>(i)</sup>)
+
+- T<sub>type</sub>:** Tool type. The value of 0 for the first BAS bit indicates a JPSEC normative tool. The value of 1 for the first BAS bit indicates a JPSEC non-normative tool. This field uses the FBAS structure.
+- T<sub>idx</sub>:** Tool instance index (can be used as a unique identifier). This field uses the RBAS structure.
+- ID:** Identification value for JPSEC tool *i*. For JPSEC normative tools, the ID = ID<sub>T</sub> is 8 bits and specifies the template type. For JPSEC non-normative tools, the ID = ID<sub>RA</sub> is defined by Figure 10 and Table 8.
+- L<sub>ZOI</sub>:** Length of ZOI in Bytes (excluding L<sub>ZOI</sub>). This field uses the RBAS structure.
+- ZOI:** Zone of influence for JPSEC tool *i*.
+- L<sub>PID</sub>:** Length of P<sub>ID</sub> in Bytes (excluding L<sub>PID</sub>). This field uses the RBAS structure.
+- P<sub>ID</sub>:** Parameters for JPSEC tool *i*.
+
+Table 5 – JPSEC tool parameter values
+
+| Parameter         | Size (bits)                                                       | Values                                                               |
+|-------------------|-------------------------------------------------------------------|----------------------------------------------------------------------|
+| T <sub>type</sub> | 8 + 8 * n (FBAS)                                                  | x0xx xxxx b, x1xx xxxx b                                             |
+| T <sub>idx</sub>  | 8 + 8 * n (RBAS)                                                  | 0 ... (2 <sup>7+7*n</sup> – 2)<br>(2 <sup>7+7*n</sup> – 1), reserved |
+| ID                | 8, if T <sub>type</sub> = 0<br>Variable, if T <sub>type</sub> = 1 | See Table 6<br>See Figure 10 and Table 8                             |
+| L <sub>ZOI</sub>  | 16 + 8 * n (RBAS)                                                 | 0 ... 2 <sup>15+7*n</sup>                                            |
+| ZOI               | Variable                                                          | See 5.7                                                              |
+| L <sub>PID</sub>  | 16 + 8 * n (RBAS)                                                 | 0 ... 2 <sup>15+7*n</sup>                                            |
+| P <sub>ID</sub>   | Variable                                                          | Table 7, if T <sub>type</sub> = 0                                    |
+
+Each JPSEC tool has the following syntax. The initial one-byte identifies if the tool is a JPSEC normative tool or JPSEC non-normative tool and assigns an instance identifier to the tool. This is followed by the tool identifier **ID**. This is followed by L<sub>ZOI</sub>, which indicates the length of the subsequent zone of influence field ZOI, and the zone of influence itself, which describes where in the data stream the JPSEC tool is applied. This is followed by L<sub>PID</sub>, which indicates the length of the following parameter field P<sub>ID</sub>, which is a field to transmit one or more parameters for the JPSEC tool.
+
+The first byte of the tool uses a one-byte FBAS structure whose first BAS bit represents the tool type, T<sub>type</sub>, where 0 specifies a JPSEC normative tool and 1 specifies a JPSEC non-normative tool. This is followed by the instance index, T<sub>idx</sub>, which is represented using the RBAS structure. The instance index shall be a unique identifier of the tool within the
+
+codestream, and thus shall not be repeated by any other tool in the codestream, even if it is in a different SEC marker segment. The instance index is especially critical (and necessary) when INSEC markers are used, because each INSEC marker segment contains the instance index of the tool to which it applies. It is recommended that the first tool applied at a JPSEC creator has an instance index of 1, and that each additional tool be indexed sequentially as it is applied at the protector.
+
+In addition, each JPSEC tool has an ID number which is 8 bits for JPSEC normative tools and 32 bits for JPSEC non-normative tools. For JPSEC normative tools, the ID number describes which protection method template is used, i.e., it specifies the decryption template, authentication template, or hash template. For JPSEC non-normative tools, the first bit indicates whether it is a JPSEC user-defined tool. In either case, the ID number indicates the particular tool. However, a JPSEC application that uses user-defined ID numbers runs the risk of choosing an ID number that is also used by another JPSEC application, so this should be used cautiously.
+
+When each JPSEC tool is applied at the JPSEC creator, the P<sub>SEC</sub> parameter field shown in Table 2 shall be updated. For example, the P<sub>SEC</sub> parameter field contains the I<sub>max</sub> parameter that specifies the maximum instance index used for the tools in the JPSEC codestream. When a new tool is applied, it shall be assigned a unique instance index. A JPSEC protector can refer to the I<sub>max</sub> parameter given in the P<sub>SEC</sub> parameter field to determine the instance index to assign to a JPSEC tool, for example, it can choose a value that is one greater than the current I<sub>max</sub> value, and it should then increment the value of I<sub>max</sub> by 1 accordingly.
+
+5.6.2 JPSEC normative tool
+
+The JPSEC normative tool uses the JPSEC tool syntax described in 5.6.1 and shown in Figure 8, where the tool type T<sub>type</sub> = 0 and the size of the ID is 8 bits. JPSEC normative tools are based on the protection method templates described in 5.8. There are three types of protection method templates; the type used by the tool is specified by the tool identifier ID = ID<sub>T</sub> using the values shown in Table 6.
+
+Table 6 – JPSEC normative tool Template ID values (ID<sub>T</sub>)
+
+| Values                                            | Protection method template |
+|---------------------------------------------------|----------------------------|
+| 0                                                 | Reserved                   |
+| 1                                                 | Decryption template        |
+| 2                                                 | Authentication template    |
+| 3                                                 | Hash template              |
+| 4                                                 | NULL tool                  |
+| All other values are reserved for ITU-T   ISO use |                            |
+
+In the case of JPSEC normative tools, the parameter field P<sub>ID</sub> has the structure shown in Figure 9. P<sub>ID</sub> consists of four main fields: the protection method template T, its processing domain PD, its granularity G, and its value list V. The syntax for each of these fields is given in 5.8, 5.9, 5.10 and 5.11, respectively. Together, these fields describe how the tool is applied. The protection method template T describes the particular protection method for the decryption template, authentication template, or hash template specified by the normative tool ID. It can also specify the NULL tool, in which case no template is used, but other functionalities can still be used. For example, the zone of influence can be specified to represent image regions and their corresponding byte ranges. The processing domain PD describes the domain in which the protection method is applied. The granularity G describes the granularity with which the protection method is applied. The value list V contains a list of values that can be needed by each protection method with finer granularity. For the decryption template, the value list can be used to specify a finer grain set of initialization values that are to be used. For the authentication template, the value list contains a set of MAC values or digital signatures. For the hash template, the value list contains a set of hash values. In all cases, the value list contains a granularity of values specified by the granularity field G.
+
+![Figure 9: Parameters (P_ID) syntax for JPSEC normative tools (t = 0). The diagram shows a horizontal rectangle divided into four sections. The first section is labeled T_ID and has diagonal hatching. The second section is labeled PD and has diagonal hatching. The third section is labeled G and is empty. The fourth section is labeled V and has diagonal hatching. Below the rectangle, the text 'T.807(23)_F09' is written.](bb3354f497635d15bef873577125c48d_img.jpg)
+
+Figure 9: Parameters (P\_ID) syntax for JPSEC normative tools (t = 0). The diagram shows a horizontal rectangle divided into four sections. The first section is labeled T\_ID and has diagonal hatching. The second section is labeled PD and has diagonal hatching. The third section is labeled G and is empty. The fourth section is labeled V and has diagonal hatching. Below the rectangle, the text 'T.807(23)\_F09' is written.
+
+Figure 9 – Parameters (P<sub>ID</sub>) syntax for JPSEC normative tools (t = 0)
+
+- T<sub>ID</sub>: Template parameters for JPSEC normative tool with template identifier ID<sub>T</sub>.
+- PD: Processing domain for JPSEC normative tool.
+- G: Granularity for JPSEC normative tool.
+
+**V:** Value list for JPSEC normative tool, e.g., initialization vectors, MAC values, digital signatures, or hash values depending on template ID.
+
+Note that the template parameters depend on the template ID. However, the processing domain, granularity, and value list are independent of the template ID.
+
+Table 7 – JPSEC normative tool parameter values
+
+| Parameter       | Size (bits)                                      | Values         |
+|-----------------|--------------------------------------------------|----------------|
+| T <sub>ID</sub> | 0, if ID <sub>T</sub> = 4<br>Variable, otherwise | N/A<br>See 5.8 |
+| PD              | Variable                                         | See 5.9        |
+| G               | 24                                               | See 5.10       |
+| V               | Variable                                         | See 5.11       |
+
+5.6.3 JPSEC non-normative tool
+
+The mechanism to register JPSEC user defined tool to JPSEC RA tool described in this clause is deprecated because the registration authority defined in the previous edition, ISO/IEC 15444-8:2007, is cancelled.
+
+In certain cases, it can be useful for a JPSEC application to have the ability to apply a tool that extends beyond the JPSEC normative tools. This capability is supported by using a JPSEC user defined tool which was called as JPSEC non-normative tool. This enables one to use many elements of JPSEC normative tools, including the ZOI and the JPSEC templates, but adds the flexibility of using the parameters in a different manner associated with a tool ID value.
+
+The JPSEC non-normative tool used the JPSEC tool syntax described in 5.6.1 and shown in Figure 8, where the tool type T<sub>type</sub> = 1 and the identifier ID<sub>RA</sub> consists of a name space and an ID number, as defined by Figure 10 and Table 8.
+
+There were two classes of JPSEC non-normative tools:
+
+- 1) JPSEC registration authority tools (Deprecated): JPSEC non-normative tools whose signalling was specified with a registration authority.
+- 2) JPSEC user-defined tools: JPSEC non-normative tools whose signalling is specified by a JPSEC application.
+
+These two classes of JPSEC non-normative tools were signalled using the 32-bit ID<sub>RA,id</sub> identifier shown in Table 9, where the identifiers whose first bit is a 0 were defined by a registration authority, and those whose first bit is a 1 are defined by a particular JPSEC application.
+
+![Diagram showing the ID_RA syntax structure. It consists of three fields: ID_RA,id (32 bits), ID_RA,nsl (8 bits), and ID_RA,ns (variable length). The fields are represented as boxes with labels and bit counts. The ID_RA,nsl and ID_RA,ns fields are shaded with diagonal lines. Below the diagram is the reference T.807(23)_F10.](6929132b4964d52244da61d4614bc4d6_img.jpg)
+
+Diagram showing the ID\_RA syntax structure. It consists of three fields: ID\_RA,id (32 bits), ID\_RA,nsl (8 bits), and ID\_RA,ns (variable length). The fields are represented as boxes with labels and bit counts. The ID\_RA,nsl and ID\_RA,ns fields are shaded with diagonal lines. Below the diagram is the reference T.807(23)\_F10.
+
+Figure 10 – ID<sub>RA</sub> syntax
+
+- ID<sub>RA,id</sub>:** Tool identifier for user-defined tool
+- ID<sub>RA,nsl</sub>:** Length of the field ID<sub>RA,ns</sub> in bytes. This field uses RBAS.
+- ID<sub>RA,ns</sub>:** A string containing the name space of the specified user-defined tool
+
+Table 8 – Parameters values in ID<sub>RA</sub> syntax
+
+| Parameter            | Size (bits)      | Values                         |
+|----------------------|------------------|--------------------------------|
+| ID <sub>RA,id</sub>  | 32               | See Table 9                    |
+| ID <sub>RA,nsl</sub> | 8 + 8 * n (RBAS) | 0 ... (2 <sup>7+7*n</sup> – 1) |
+| ID <sub>RA,ns</sub>  | Variable         | A string containing namespace  |
+
+Table 9 – ID values for JPSEC non-normative tools (ID<sub>RA,id</sub>)
+
+| ID <sub>RA,id</sub>             | Meaning                                                                                                                                                             |
+|---------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| 0x00 00 00 00 ... 0x7F FF FF FF | Previously managed by JPSEC RA (Registration Authority) tool. Values were to be managed by JPSEC registration authority (Deprecated). Reserved for ITU-T   ISO use. |
+| 0x80 00 00 00 ... 0xEF FF FF FF | JPSEC user-defined tool. Values can be defined by a particular JPSEC application.                                                                                   |
+| 0xF0 00 00 00 ... 0xFF FF FF FF | Reserved for ITU-T   ISO use.                                                                                                                                       |
+
+For RA tools, the field ID<sub>RA,ns</sub> was the name space of the Registration Authority (RA) with which this tool is registered. As each RA had a unique name space, the ID<sub>RA,id</sub> and ID<sub>RA,ns</sub> were used together to identify an RA tool. For user-defined tools, the field ID<sub>RA,ns</sub> is chosen by the developers. In order to limit the risk of ID collisions, it is recommended that the developers seek uniqueness when choosing their name space, for example, by choosing the domain name of their organization or company. However, note that for user-defined tools, there is no way to guarantee that uniqueness of the name space, so ID collision can occur and should be carefully considered when using user-defined tools.
+
+The P<sub>ID</sub> field is used to transmit one or more parameters for the JPSEC non-normative tool *i*. The format of the P<sub>ID</sub> field is not fully given in the scope of JPSEC. If a user-defined is used, then only the length of this field is specified, and it is up to the users to appropriately use this field.
+
+However, JPSEC does allow the syntactical structures defined for JPSEC normative tools to be used in the P<sub>ID</sub> field for JPSEC non-normative tools. For example, a JPSEC non-normative tool can use the protection method templates, processing domain, granularity, and value list fields described in 5.8, 5.9, 5.10 and 5.11, respectively.
+
+This syntax is very flexible and can accommodate a wide variety of security techniques, such as image data integrity, access control and rights protection methods. Hence, it offers a rich set of functionalities while being simple and concise.
+
+5.7 Zone of Influence (ZOI) syntax
+
+5.7.1 Introduction
+
+The Zone of Influence (ZOI) can be used to describe the coverage area of a JPSEC tool. The data within the coverage area (specified by the ZOI) is referred to as the influenced data. JPSEC normative tools shall use the ZOI to describe their coverage area. JPSEC non-normative tools can use the ZOI to describe their coverage area or they can use an alternative method. If an alternative method is used, then the ZOI length is 0, i.e., it does not exist.
+
+The Zone of Influence (ZOI) describes the coverage area of each JPSEC tool. This coverage area can be described by image-related parameters, e.g., by resolution or image area; or by non-image related parameters, e.g., by codestream segments or packet indices. In cases where image related parameters and non-image related parameters are used together, the ZOI describes the correspondence between these areas. For example, the ZOI can be used to indicate that the resolutions and image area specified by the image related parameters correspond to the codestream segments specified by the non-image related parameters. This allows the ZOI to be used as metadata that signals where certain parts of the image are located in the JPSEC codestream.
+
+Figure 11 illustrates the conceptual structure of the ZOI. The ZOI contains one or more zones. When multiple zones are used within a single ZOI, the ZOI is defined by their union. This indicates that the JPSEC tool should be applied to all the zones. Each zone in a ZOI is described by three fundamental units: description class, parameter mode and parameter items (values). This Recommendation | International Standard defines two description classes: image related description class and non-image related description class. These parameters can be specified using a number of modes, for example, by a single value, multiple listed values, or by a range. The parameter values or items are then listed in accordance with the mode.
+
+![Figure 11 – Zone of Influence conceptual structure. A hierarchical tree diagram showing the structure of a Zone of Influence (ZOI). At the top is 'ZOI', which branches into 'Zone 1', 'Zone 2', 'Zone 3', an ellipsis, and 'Zone N'. These zones are connected by a union symbol 'U'. 'Zone 1' further branches into 'Class', 'Parameter 1', 'Parameter 2', an ellipsis, and 'Parameter M'. These parameters are connected by an intersection symbol '∩'. 'Parameter 1' branches into 'Mode', 'Item 1', 'Item 2', an ellipsis, and 'Item L'. These items are connected by a union symbol 'U'. The label 'T.807(23)_F11' is at the bottom right.](2bacc162a73d75c43a7f90715832bd13_img.jpg)
+
+```
+graph TD
+    ZOI[ZOI] --> Z1[Zone 1]
+    ZOI --> Z2[Zone 2]
+    ZOI --> Z3[Zone 3]
+    ZOI --> Dots1[...]
+    ZOI --> ZN[Zone N]
+    Z1 -- U --> Z2
+    Z2 -- U --> Z3
+    Z3 -- U --> Dots1
+    Dots1 -- U --> ZN
+    Z1 --> C[Class]
+    Z1 --> P1[Parameter 1]
+    Z1 --> P2[Parameter 2]
+    Z1 --> Dots2[...]
+    Z1 --> PM[Parameter M]
+    P1 -- ∩ --> P2
+    P2 -- ∩ --> Dots2
+    Dots2 -- ∩ --> PM
+    P1 --> M[Mode]
+    P1 --> I1[Item 1]
+    P1 --> I2[Item 2]
+    P1 --> Dots3[...]
+    P1 --> IL[Item L]
+    I1 -- U --> I2
+    I2 -- U --> Dots3
+    Dots3 -- U --> IL
+```
+
+Figure 11 – Zone of Influence conceptual structure. A hierarchical tree diagram showing the structure of a Zone of Influence (ZOI). At the top is 'ZOI', which branches into 'Zone 1', 'Zone 2', 'Zone 3', an ellipsis, and 'Zone N'. These zones are connected by a union symbol 'U'. 'Zone 1' further branches into 'Class', 'Parameter 1', 'Parameter 2', an ellipsis, and 'Parameter M'. These parameters are connected by an intersection symbol '∩'. 'Parameter 1' branches into 'Mode', 'Item 1', 'Item 2', an ellipsis, and 'Item L'. These items are connected by a union symbol 'U'. The label 'T.807(23)\_F11' is at the bottom right.
+
+Figure 11 – Zone of Influence conceptual structure
+
+5.7.2 ZOI syntax
+
+Figure 12 shows the ZOI syntax. The ZOI can contain one or more zones. It can also be empty, in which case NZzoi shall be 0. When this occurs, the influence of the tool is specified by other means, such as by the INSEC marker or by parameters defined by a JPSEC non-normative protection tool.
+
+![Figure 12 – ZOI syntax. A diagram showing the bit fields of a ZOI. It consists of three parts: 'NZ_zoi' (Number of Zones), 'Zone^1' (Zone 1), and 'Zone^NZ_zoi' (Zone NZ_zoi). The 'NZ_zoi' and 'Zone^1' fields are shaded with diagonal lines. The 'Zone^NZ_zoi' field is also shaded with diagonal lines. The label 'T.807(23)_F12' is at the bottom right.](6ca05954842b17f14dfd52f26b9d43d2_img.jpg)
+
+```
+graph LR
+    NZ_zoi[NZ_zoi]
+    Zone1[Zone^1]
+    ZoneNZ_zoi[Zone^NZ_zoi]
+```
+
+Figure 12 – ZOI syntax. A diagram showing the bit fields of a ZOI. It consists of three parts: 'NZ\_zoi' (Number of Zones), 'Zone^1' (Zone 1), and 'Zone^NZ\_zoi' (Zone NZ\_zoi). The 'NZ\_zoi' and 'Zone^1' fields are shaded with diagonal lines. The 'Zone^NZ\_zoi' field is also shaded with diagonal lines. The label 'T.807(23)\_F12' is at the bottom right.
+
+Figure 12 – ZOI syntax
+
+**NZzoi:** Number of Zones. This field uses the RBAS structure.  
+**Zone<sup>k</sup>:** Zone. Its structure is specified in 5.7.3.
+
+Table 10 – Zone of influence field (ZOI) parameter values
+
+| Parameter         | Size (bits)      | Values                                                               |
+|-------------------|------------------|----------------------------------------------------------------------|
+| NZzoi             | 8 + 8 * n (RBAS) | 0 ... (2 <sup>7+7*n</sup> - 2)<br>(2 <sup>7+7*n</sup> - 2), reserved |
+| Zone <sup>k</sup> | Variable         | See 5.7.3                                                            |
+
+5.7.3 Zone syntax
+
+The Zone contains a zone description class field indicator followed by parameters of that class. The zone description class uses the FBAS structure. As shown in Figure 13, the second most significant bit in each byte, labelled "x", flags the use of a specific description class. This Recommendation | International Standard defines two description classes: image related description class and a non-image related description class (see Table 12). Tables 13 and 14 define the field indicator numbers for the image related description class and non-image related description class, respectively. The concatenation of the six bits labelled "y", in each byte that follow the description class flag, indicates the use of a specific description within a given description class. A bit value of "1" at a bit number in each class indicates that the corresponding parameter field exists. The number of parameters shall be the same as the number of zone description class field indicators set to '1', and shall appear in order which the class field indicator is signalled. The zone description class has variable number of bytes; when the MSB equals 1, then another zone description class byte follows. The MSB of the last description class byte equals 0. If both the image related and non-image related description classes are used, then the image related description class bytes shall precede the non-image related description class byte. When a number of items are represented using this structure, the first item in the list shall correspond to the most significant available bit of the first byte.
+
+![](5414f65867392f05ba0063b208eeb5e1_img.jpg)
+
+MSB
+
+|   |   |   |   |   |   |   |   |
+|---|---|---|---|---|---|---|---|
+| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
+| 1 | x | y | y | y | y | y | y |
+
+...
+
+|   |   |   |   |   |   |   |   |
+|---|---|---|---|---|---|---|---|
+| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
+| 1 | x | y | y | y | y | y | y |
+
+...
+
+|   |   |   |   |   |   |   |   |
+|---|---|---|---|---|---|---|---|
+| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
+| 0 | x | y | y | y | y | y | y |
+
+LSB
+
+T.807(23)\_F13
+
+Figure 13 – Zone description class structure (DCzoi)
+
+Figure 14 shows the Zone syntax.
+
+![Diagram showing the Zone syntax structure: DCzoi^k, Pzoi^i,k, and Pzoi^NZzoi^k,k.](744acfe8d4e31bcf03f95714c2f6e567_img.jpg)
+
+T.807(23)\_F14
+
+Diagram showing the Zone syntax structure: DCzoi^k, Pzoi^i,k, and Pzoi^NZzoi^k,k.
+
+Figure 14 – Zone syntax consists of a description class and one or more parameter sets
+
+- DCzoi<sup>k</sup>**: kth Zone description class. This field uses the FBAS structure.
+- Pzoi<sup>i,k</sup>**: The Zone parameters according to the specified Zone description class (DCzoi<sup>k</sup>). See 5.7.6.
+
+DCzoi<sup>k</sup> specifies the number *n* of zone description class fields that exist, based on the number of bits that are set to one. For each zone description class field, there exists one Pzoi<sup>i,k</sup> zone parameter field. These fields appear sequentially in the same order that the flags appear in DCzoi<sup>k</sup>.ZA
+
+Table 11 – Zone parameter values
+
+| Parameter           | Size (bits)     | Values                                        |
+|---------------------|-----------------|-----------------------------------------------|
+| DCzoi <sup>k</sup>  | Variable (FBAS) | Varies according to the value set in Table 12 |
+| Pzoi <sup>i,k</sup> | Variable        | See 5.7.6 for the syntax of this field        |
+
+Table 12 – Description class indicator value
+
+| Value | Description class                                                                      |
+|-------|----------------------------------------------------------------------------------------|
+| 0     | Image related description class. The following bit numbers are defined in Table 13     |
+| 1     | Non-image related description class. The following bit numbers are defined in Table 14 |
+
+Table 13 – Image related description class
+
+| Bit number | Semantics                                                                     |
+|------------|-------------------------------------------------------------------------------|
+| 1          | Image region                                                                  |
+| 2          | Tile(s) as defined in the JPEG 2000 Core coding system                        |
+| 3          | Resolution level(s) as defined in the JPEG 2000 Core coding system            |
+| 4          | Layer(s) as defined in the JPEG 2000 Core coding system                       |
+| 5          | Component(s) as defined in the JPEG 2000 Core coding system                   |
+| 6          | Precinct(s) as defined in the JPEG 2000 Core coding system                    |
+| 7          | TRLCP (Tile-Resolution-Layer-Component-Precinct) tag(s)                       |
+| 8          | Packet(s) as defined in the JPEG 2000 Core coding system                      |
+| 9          | Sub-band(s) as defined in the JPEG 2000 Core coding system                    |
+| 10         | Code-block(s) as defined in the JPEG 2000 Core coding system                  |
+| 11         | ROI(s)                                                                        |
+| 12         | Bit-rate                                                                      |
+| 13         | User-defined. The details shall be specified by other means. (e.g., JPSEC ID) |
+|            | All other values are reserved                                                 |
+
+**Table 14 – Non-image related description class**
+
+| Bit number | Semantics                                                                     |
+|------------|-------------------------------------------------------------------------------|
+| 1          | Packet(s) as defined in the JPEG 2000 Core coding system                      |
+| 2          | (Padded) Byte range(s) (beginning at first byte after the first SOD marker)   |
+| 3          | (Padded) Byte range(s) (beginning at first byte after the first SEC marker)   |
+| 4          | Unpadded byte range(s) when padding is used                                   |
+| 5          | TRLCP (Tile-Resolution-Layer-Component-Precinct) tag(s)                       |
+| 6          | Distortion value(s)                                                           |
+| 7          | Relative importance(s)                                                        |
+| 8          | User-defined. The details shall be specified by other means. (e.g., JPSEC ID) |
+|            | All other values are reserved                                                 |
+
+Packet indices are numbered sequentially within a tile, and therefore they are not necessarily unique across tiles. Furthermore, packet indices within a tile can roll over when their maximum value of 65535 is exceeded. For this reason, packet indexing is described in more detail. When the packet indices within a tile do not exceed 65535 packets, then the packet index described in Table 13 is defined by the packet index given by the SOP Nsop parameter as defined in Table A.40 in the JPEG 2000 Core coding system standard. Note that when the maximum value does not exceed 65536, a single JPEG 2000 packet can be specified uniquely with a tile index and a packet index. When the packet indices exceed 65535 packets, then the JPEG 2000 Core coding system packet index is defined to roll over to 0. In this case, the packet index does not uniquely identify a packet and shall not be used. In this case, it is recommended to use the TRLCP tag instead. Please note that security services which require unique packet indices are vulnerable if the packet index rolls over and repeats.
+
+When the TRLCP tag is used, its format shall be defined in the P<sub>SEC</sub> parameter field shown in Table 2. Specifically, the TRLCP tag format is specified by the P<sub>TRLCP</sub> parameter field in Table 4. This defines the size of TRLCP tags in the ZOI.
+
+The non-image related description class can also have multiple fields set simultaneously. When this occurs, the modes for the various parameter fields shall have the same number of items (one exception to this rule is described below), and these items shall correspond with one another in a one-to-one manner in the same order. For example, if the zone uses byte ranges and packet ranges, each should have the same number of range items where the first byte range corresponds to the first packet range, and so on.
+
+There is one exception to the above rule on requiring the same number of items for each field. This occurs when one of the fields f1 contains 1 item which specifies a range of items (as described by the range mode in 5.7.6) where this range contains N elements and when another field f2 is specified by a list of N items. In this case, the field f1, which contains only 1 item (the range) is interpreted as a list of N items. These N items specified by the range in f1 shall correspond one-to-one with the N items listed in f2. Therefore, a range of items can be associated to either a single item or to multiple items (one for each item in the range).
+
+The bytes are indexed either from the first byte after the first SOD marker or from the first byte after the first SEC marker. In either case, this first byte is labelled as byte 0.
+
+The distortion fields (both the distortion and relative importance fields) provide the capability to signal the importance of areas specified by the ZOI. The distortion parameter specifies the distortion-reducing contribution of the specified data segment, be it for a set of packets or a byte range or for the specified image-related area. The distortion is expressed in terms of the total squared error, using either a one-byte or a two-byte description signalled in the Mzoi. The relative distortion parameter can be used to specify the relative importance of specified data segments, using either one-byte, two-byte, or four-byte values signalled in the Mzoi. Additional details and the formats of these fields is described in 5.7.3.2.
+
+The TRLCP tag specifies a protected packet's tile, resolution, layer, component, and precinct in the codestream. This tag is used in the ZOI to specify these parameters because this information can be difficult to infer in a protected codestream.
+
+Note that when only image-related descriptions are used, the field can be terminated. Thus, one does not need to represent non-image related descriptions if they are not used.
+
+### 5.7.3.1 Byte range fields
+
+The non-image-related description class allows the ZOI to be described in byte ranges. In general, the 2nd and 3rd elements of Table 14 should be used to represent the byte ranges for most tools such as authentication and encryption/decryption without padding. However, some protection methods, such as encryption/decryption with padding, change the length of the data. When this occurs, both the padded byte range and the unpadded or original byte range are specified. In this case, the padded byte range is specified by the 2nd or 3rd element of Table 14 according to the needs of the protection tool. (Note that these two elements cannot be used together.) In addition, the unpadded byte range is
+
+specified by the 4th element of Table 14. The unpadded byte range should be specified with the same description mode as the padded byte range and have same number of items. These items should correspond to each other in a one-to-one manner in the same order.
+
+5.7.3.2 Distortion field and relative importance field
+
+The distortion and relative importance fields provide the capability to signal the importance of areas specified by the ZOI. The distortion field is used to associate a distortion with an area specified by the ZOI. The distortion value specifies the total squared error (or sum of squared error) distortion that would result if the associated area is not available for decoding. Total squared error distortion is a basic distortion metric used in image and video processing, and it is used to derive the common mean-squared-error (MSE) distortion and peak-signal-to-noise (PSNR) ratio. The distortion field is expressed using a one-byte or a two-byte description, where these one-byte and two-byte descriptions are described below, and the choice of one-byte or two-byte description is signalled by the Mzoi parameter value which specifies the length of this field. The relative importance field can be used to describe the relative importance among different areas specified by associated ZOIs, without necessarily being tied to a specific distortion metric. The length of the relative importance field is also signalled by the Mzoi. These fields are discussed in more detail in the following.
+
+5.7.3.2.1 One-byte distortion field
+
+The total squared error distortion is expressed using a one-byte distortion field with a pseudo floating-point type representation. The 8 bits available in the distortion field are allocated as shown in Figure 15 and Table 15 to provide an appropriate trade-off between accuracy and dynamic range. Note that a sign bit is unnecessary since distortion is non-negative. To cover a sufficient dynamic range, base 16 is used and 4 bits are used for the exponent (exp). The mantissa (m) is expressed using 4 bits. Therefore, the total distortion value D is given by:
+
+D = m × 16<sup>exp</sup>
+
+where m has a value in the range 0 ≤ m ≤ 15 and exp has a value in the range 0 ≤ exp ≤ 15. A distortion value of zero is represented by m = 0 and exp = 0, that is by the distortion field being zero. By allocating 4 bits for the mantissa m the accuracy is within ½ × (1/2<sup>4</sup>) = 1/32 or about 3%. With 4 bits for the exponent and using base-16 the dynamic range is from 0 to max, where max is given by m = 15 and exp = 15 which corresponds to a distortion of 15 × 16<sup>15</sup> = 1.7 × 10<sup>19</sup>.
+
+![Diagram of the distortion field syntax showing an 8-bit field divided into two 4-bit sections: 'exp' (bits 3, 2, 1, 0) and 'm' (bits 3, 2, 1, 0).](f0b7abcb093621bb310bf61fbe0f0d2d_img.jpg)
+
+T.807(23)\_F15
+
+Diagram of the distortion field syntax showing an 8-bit field divided into two 4-bit sections: 'exp' (bits 3, 2, 1, 0) and 'm' (bits 3, 2, 1, 0).
+
+Figure 15 – Distortion field syntax
+
+- exp: Exponent of distortion field value (base 16)
+- m: Matissa of distortion field value
+
+Table 15 – Distortion field parameter values
+
+| Parameter | Size (bits) | Values   |
+|-----------|-------------|----------|
+| exp       | 4           | 0 ... 15 |
+| m         | 4           | 0 ... 15 |
+
+Note that with this format for the distortion, a comparison between two distortions to determine which is larger can be simply achieved by comparing the two distortion values as unsigned char. Specifically, to perform this comparison there is no need to convert from the pseudo floating-point format to the actual total distortion in order to determine which of two distortion values is larger or smaller. This property can simplify the processing in various applications.
+
+5.7.3.2.2 Two-byte distortion field
+
+In the two-byte format as shown in Figure 16, distortion values shall be expressed as a two-byte number in pseudo floating-point format. The pseudo floating-point format for distortion is defined as follows. This format is used in D.1.1.1 (Equation D.3) of Rec. ITU-T T.800 | ISO/IEC 15444-1 to express the quantization step size for JPEG 2000. Each 16-bit number contains the exponent (5 bits) and mantissa (11 bits) of the metric value. In particular, the floating-point value V of the metric is given by the following formula:
+
+V = 2<sup>ε-15</sup> ( 1 + <sup>μ</sup> / 2<sup>11</sup> ) if ε ≠ 0  
+V = 0 if ε = 0
+
+where  $\varepsilon$  is the unsigned integer obtained from the first five most significant bits of the parameter, and  $\mu$  the unsigned integer obtained from the remaining 11 bits. The special case of  $V = \infty$  correspond to  $\mu = 0$  and  $\varepsilon = 31$ . Note that values that would underflow the representation are set to zero.
+
+![Figure 16: Distortion field syntax diagram. It shows a 16-bit field divided into two parts. The first 5 bits are labeled with indices 4, 3, 2, 1, 0 and are collectively labeled ε. The next 11 bits are labeled with indices A, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0 and are collectively labeled μ. Below the diagram is the label T.807(23)_F16.](318886a86a1dcc59e1fc83db6f157c60_img.jpg)
+
+Figure 16: Distortion field syntax diagram. It shows a 16-bit field divided into two parts. The first 5 bits are labeled with indices 4, 3, 2, 1, 0 and are collectively labeled ε. The next 11 bits are labeled with indices A, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0 and are collectively labeled μ. Below the diagram is the label T.807(23)\_F16.
+
+Figure 16 – Distortion field syntax
+
+- ε: Exponent of two-byte distortion field value.
+- μ: Matissa of two-byte distortion field value.
+
+Table 16 – Distortion field parameter values
+
+| Parameter | Size (bits) | Values                      |
+|-----------|-------------|-----------------------------|
+| ε         | 5           | 0 ... 31                    |
+| μ         | 11          | 0 ... (2 <sup>11</sup> – 1) |
+
+The algorithm to compute  $\varepsilon$  and  $\mu$  is not defined as a mandatory part of this Recommendation | International standard. A possible technique performs the following steps (an example of conversion of the number 12.25 is provided). If  $V = 0$ , set  $\varepsilon = \mu = 0$ . Otherwise:
+
+- convert  $V$  to a binary number ( $12.25_{10} = 1100.01_2$ );
+- normalize the number; this means there should be a 1 digit to the left of the binary point and multiplication by the appropriate power of two to represent the original value. The normalized form of 1100.01 is  $1.10001 \times 2^3$ ;
+- the exponent is the power of 2, presented in excess notation. The exponent bias is 15; hence for this example the exponent is represented as  $18_{10}$  ( $10010_2$ );
+- the mantissa represents the significant bits, *except for the bit to the left of the binary point*, which is always one and therefore does not need to be stored; zeros are possibly appended so as to obtain 11 bits. For this example, the mantissa is 10001000000.
+
+5.7.3.2.3 Relative importance field
+
+The relative importance field  $r$  can be used to describe the relative importance among different coding units, without necessarily being tied to a specific distortion metric. This enables one to describe the relative importance or prioritization among coding units without explicitly describing how much more important one is from another. This relative importance of the associated data is specified by an  $n$ -byte field which supports  $2^{8n}$  possible rankings as shown in Figure 17 and Table 16, where the number of bytes  $n$  for this field is specified by  $Mzoi$ . For example, by using a one-byte relative importance field a total of 256 possible rankings are supported. Increasing values correspond to increasing importance, in a similar manner to the distortion field.
+
+![Figure 17: Relative importance field syntax diagram. It shows a square box with diagonal hatching and the letter r in the center. Below the diagram is the label T.807(23)_F17.](f324fbc5d5af1e4da9cd932389f0064c_img.jpg)
+
+Figure 17: Relative importance field syntax diagram. It shows a square box with diagonal hatching and the letter r in the center. Below the diagram is the label T.807(23)\_F17.
+
+Figure 17 – Relative importance field syntax
+
+- r: Relative importance value
+
+Table 17 – Relative importance field parameter values
+
+| Parameter | Size (bits) | Values                      |
+|-----------|-------------|-----------------------------|
+| r         | 8 * n       | 0 ... (2 <sup>8n</sup> – 1) |
+
+5.7.3.2.4 Additional comments on distortion field and relative importance field
+
+Since for both the one-byte distortion field and one-byte relative importance field the larger values correspond to greater importance, it is possible to make comparisons for these two data units in the same manner irrespective of whether the distortion field specifies actual distortion or a relative importance. This can simplify applications.
+
+Headers can be specified using the distortion or relative importance fields. The loss of various types of data, such as the main and tile-part headers or the SEC header, prevent the decoding of the related image data. The JPSEC creator can assign distortion to this data using either:
+
+- 1) the highest distortion value (specified next) to signal the header or critical data; or
+- 2) to describe the total distortion that would be created if the image or portion of the image is undecodable.
+
+The creator then has some flexibility in how to signal the headers.
+
+The highest distortion value for the one-byte fields is a byte of all ones (0xFF). Note that this value is the highest possible distortion value for both the one-byte total squared error distortion field and for the one-byte relative importance field. The highest distortion value for the two-byte distortion field is the two bytes of all ones (0xFFFF). The highest importance for the relative importance field of length n-bytes is an n-byte value of all ones.
+
+5.7.3.2.5 Joint use of distortion field and relative importance field
+
+The distortion field and relative importance field can be used simultaneously to describe the area specified by the ZOI. In this case both fields specify squared-error distortion, however the distortion field specifies the incremental reduction in distortion while the relative importance field specifies the total distortion. Specifically, the distortion field specifies the incremental reduction in distortion that the ZOI would produce if decoded. This assumes that all information required to decode the ZOI is available, and focuses on the incremental reduction in distortion produced by the ZOI. The relative importance field specifies the total distortion that would be incurred if the ZOI is not available, i.e., it specifies the total distortion that would result if the given ZOI is unavailable for decoding by accounting not only for the value of the ZOI itself (as expressed by the distortion field) but also accounting for the distortion produced because other parts of the compressed bitstream which depend on the ZOI are undecodable. The total distortion associated with different ZOIs provides a useful metric for the relative importance of the different ZOIs. When both fields are used they will use the same mathematical expression for distortion, as signalled by the distortion field.
+
+5.7.3.3 Bit-rate field
+
+The Bit-rate field is used to specify the protected zone in wavelet coefficient domain. It identifies the most significant bit-planes whose compressed bit-rate is specified by this field. The MSBs are selected using the rate-distortion optimization process specified in the JPEG 2000 Core coding system. For example, if the Bit-rate value is 2.5, the protected zone includes the MSBs of all wavelet coefficients whose compressed bit-rate is 2.5 bit per pixel. The syntax of Bit-rate field is shown in Figure 18 and Table 18. The specified bit-rate is given by:
+
+R = I<sub>R</sub> + F<sub>R</sub>/16
+
+For example, a bit-rate of zero is represented by I<sub>R</sub> = 0 and F<sub>R</sub> = 0; a bit-rate value of 2.5 is represented by I<sub>R</sub> = 2 and F<sub>R</sub> = 8.
+
+![Diagram showing the bit-rate field syntax. It consists of two 4-bit fields, I_R and F_R, each represented by a box divided into four segments labeled 3, 2, 1, 0 from left to right. Below the boxes is the label T.807(23)_F18.](8be52e8ae172cee527c14d299d386f3c_img.jpg)
+
+T.807(23)\_F18
+
+Diagram showing the bit-rate field syntax. It consists of two 4-bit fields, I\_R and F\_R, each represented by a box divided into four segments labeled 3, 2, 1, 0 from left to right. Below the boxes is the label T.807(23)\_F18.
+
+Figure 18 – Bit-rate field syntax
+
+- I<sub>R</sub>: The integer part of the specified bit-rate.
+- F<sub>R</sub>: The fractional part of the specified bit-rate.
+
+Table 18 – Bit-rate field parameter values
+
+| Parameter      | Size (bits) | Values   |
+|----------------|-------------|----------|
+| I <sub>R</sub> | 4           | 0 ... 15 |
+| F <sub>R</sub> | 4           | 0 ... 15 |
+
+## 5.7.4 Relationship between multiple parameters
+
+### 5.7.4.1 Global
+
+When the image-related description class has multiple fields set simultaneously, the resulting zone shall be the intersection of these fields. For example, a zone could specify the lowest resolution level in the 2nd tile. The union of fields can be specified by using multiple zones in the ZOI.
+
+The non-image related description class can also have multiple fields set simultaneously. When this occurs, the modes for the various parameter fields shall have the same number of items (one exception to this rule is described below), and these items shall correspond with one another in a one-to-one manner. For example, if the zone uses byte ranges and packet ranges, each should have the same number of range items where the first byte range corresponds to the first packet range, and so on.
+
+There is one exception to the above rule on requiring the same number of items for each field. This occurs when one of the fields f1 contains 1 item which specifies a range of items (as described by the range mode in 5.7.6) where this range contains N elements and when another field f2 is specified by a list of N items. In this case, the field f1, which contains only 1 item (the range) is interpreted as a list of N items. These N items specified by the range in f1 shall correspond one-to-one with the N items listed in f2. Therefore, a range of items can be associated to either a single item or to multiple items (one for each item in the range).
+
+### 5.7.4.2 Examples
+
+As previously illustrated in Figure 11, the zone description class structure can have multiple fields set simultaneously, where N fields are image related descriptions ( $D_i^1, D_i^2, \dots, D_i^N$ ) and M fields are non-image related descriptions ( $D_n^1, D_n^2, \dots, D_n^M$ ). The semantics can be understood as  $\{D_i^1 \cap D_i^2 \cap \dots \cap D_i^N\} = D_n^1 = D_n^2 = \dots = D_n^M$ , that is, the intersection of the N image related descriptions is corresponding to each of the M non-image related descriptions, and in addition, the M non-image related descriptions are mutually corresponding to each other. This relationship is further illustrated with three examples below.
+
+In the first example, the zone description has two image related descriptions: one for resolution 2 and the other for layer 3. In this case, the influenced data is the intersection of resolution 2 and layer 3, as illustrated in Figure 19.
+
+![Figure 19: ZOI example using image related descriptions. The diagram shows a sequence of tiles labeled L.0, L.1, L.2, and L.3, grouped under three resolution levels: Res 0, Res 1, and Res 2. Each resolution level contains a sequence of these tiles. The L.3 tiles in the Res 2 group are shaded with diagonal lines and labeled 'Protected data'. A bracket below the Res 2 group points to the L.3 tiles, and a label 'T.807(23)_F19' is next to it.](b2ddf2a678bd20b1b491023eb1db6458_img.jpg)
+
+Figure 19: ZOI example using image related descriptions. The diagram shows a sequence of tiles labeled L.0, L.1, L.2, and L.3, grouped under three resolution levels: Res 0, Res 1, and Res 2. Each resolution level contains a sequence of these tiles. The L.3 tiles in the Res 2 group are shaded with diagonal lines and labeled 'Protected data'. A bracket below the Res 2 group points to the L.3 tiles, and a label 'T.807(23)\_F19' is next to it.
+
+Figure 19 – ZOI example using image related descriptions
+
+In the second example as illustrated in Figure 20, the zone description has two image related descriptions (which are resolution 2 and layer 3) and one non-image related description (which is packet range 80-100). In this case, the influenced data is the intersection of resolution 2 and layer 3. Furthermore, this indicates that the influenced data is contained in packets ranging from 80 to 100.
+
+![Figure 20: ZOI example using image related and non-image related descriptions. The diagram shows a sequence of tiles labeled L.0, L.1, L.2, and L.3, grouped under three resolution levels: Res 0, Res 1, and Res 2. Each resolution level contains a sequence of these tiles. The L.3 tiles in the Res 2 group are shaded with diagonal lines and labeled 'Protected data'. A bracket below the Res 2 group points to the L.3 tiles, and a label 'T.807(23)_F20' is next to it. A callout box points to the 'Protected data' label with the text 'Packet range 80 to 100'.](4b587081b669e7c6695b0e5db5ea7f6d_img.jpg)
+
+Figure 20: ZOI example using image related and non-image related descriptions. The diagram shows a sequence of tiles labeled L.0, L.1, L.2, and L.3, grouped under three resolution levels: Res 0, Res 1, and Res 2. Each resolution level contains a sequence of these tiles. The L.3 tiles in the Res 2 group are shaded with diagonal lines and labeled 'Protected data'. A bracket below the Res 2 group points to the L.3 tiles, and a label 'T.807(23)\_F20' is next to it. A callout box points to the 'Protected data' label with the text 'Packet range 80 to 100'.
+
+Figure 20 – ZOI example using image related and non-image related descriptions
+
+In the third example as illustrated in Figure 21, the zone description has two image related descriptions (which are resolution 2 and layer 3) and two non-image related descriptions (which are packet range 80-100 and byte range 856-1250). Once again, the influenced data is the intersection of resolution 2 and layer 3, and the influenced data is
+
+contained in packets ranging from 80 to 100. Furthermore, these packets and influenced area are located in the byte range 856-1250.
+
+![Diagram showing a sequence of packets (L.0, L.1, L.2, L.3) grouped into three sets (Res 0, Res 1, Res 2). The L.3 packets are shaded and labeled as 'Protected data'. A callout indicates 'Packet range 80 to 100' and 'Byte range 856 to 1250'.](1142ba0197b158bb198186fe8baccc32_img.jpg)
+
+The diagram illustrates a sequence of packets labeled L.0, L.1, L.2, and L.3. These are grouped into three sets labeled Res 0, Res 1, and Res 2. The L.3 packets in each set are shaded with diagonal lines and are collectively labeled as 'Protected data'. A callout box points to the shaded area, indicating 'Packet range 80 to 100' and 'Byte range 856 to 1250'. The reference T.807(23)\_F21 is noted at the bottom right.
+
+Diagram showing a sequence of packets (L.0, L.1, L.2, L.3) grouped into three sets (Res 0, Res 1, Res 2). The L.3 packets are shaded and labeled as 'Protected data'. A callout indicates 'Packet range 80 to 100' and 'Byte range 856 to 1250'.
+
+Figure 21 – A second ZOI example using image related and non-image related descriptions
+
+5.7.5 Protecting any data that follows the SEC marker
+
+The above discussion has largely focused on supporting protection services for the JPEG 2000 codestream. However, many elements of the main header, including JPSEC signalling, should also be protected, and the ZOI and protection methods can also be used for this purpose.
+
+Specifically, the byte range mode of the non-image related description class can be used to specify that a JPSEC tool should be applied to any data following the SEC marker. As described before, the first byte of the SEC header is byte 1 for indexing the byte range. The data that follows the SEC marker and that can be protected includes the SEC segment and most of the main header. Note that all of the JPEG 2000 main header, except for the SIZ marker segment, can be moved after the SEC marker and hence can be protected using the above approach. If the JPEG 2000 SIZ marker segment is to be protected, it can be done at a higher level, e.g., file format layer.
+
+The JPSEC tools for protecting the SEC segment should generally be the first tools in the SEC segment. This enables the consumer to first render the SEC segment data, which can then be used to process the remainder of the codestream.
+
+5.7.6 Zone description parameter syntax (Pzoi)
+
+Figure 22 shows the ZOI description parameter syntax.
+
+![Diagram showing the ZOI description parameter syntax: M_zoi, N_zoi, I_zoi^1, and I_zoi^2-zoi^n.](3db5d62ad46e33647ec2b1ad6d2703bb_img.jpg)
+
+The diagram shows the syntax for ZOI description parameters:  $M_{zoi}$ ,  $N_{zoi}$ ,  $I_{zoi}^1$ , and  $I_{zoi}^2 \dots I_{zoi}^n$ . The parameters are represented as boxes with diagonal shading. The reference T.807(23)\_F22 is noted at the bottom right.
+
+Diagram showing the ZOI description parameter syntax: M\_zoi, N\_zoi, I\_zoi^1, and I\_zoi^2-zoi^n.
+
+Figure 22 – ZOI description parameter syntax
+
+- Mzoi:** ZOI description mode. This field uses the FBAS structure.
+- Nzoi:** Number of Izoi. This field uses RBAS structure.
+- Izoi<sup>i</sup>:** Item.
+
+Table 19 – Pzoi<sup>i</sup> parameter values
+
+| Parameter         | Size (bits)           | Values                                                          |
+|-------------------|-----------------------|-----------------------------------------------------------------|
+| Mzoi              | Variable (FBAS)       | See Table 20                                                    |
+| Nzoi              | 0<br>8 + 8 * n (RBAS) | If bit number 2 of Mzoi is 0.<br>2 ... (2 <sup>7+7*n</sup> – 1) |
+| Izoi <sup>i</sup> | Variable              | Depends on the mode specified in Mzoi                           |
+
+Table 20 – Mzoi parameter values
+
+| FBAS bit number | Values (bits) | Semantics                                                                                                                                                                                                                                                                                                                                                                                                                          |
+|-----------------|---------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| 1               | 0             | The specified zones are influenced by the JPSEC tool                                                                                                                                                                                                                                                                                                                                                                               |
+|                 | 1             | The complement of specified zones are influenced                                                                                                                                                                                                                                                                                                                                                                                   |
+| 2               | 0             | Single item is specified                                                                                                                                                                                                                                                                                                                                                                                                           |
+|                 | 1             | Multiple items are specified                                                                                                                                                                                                                                                                                                                                                                                                       |
+| 3, 4            | 00            | Rectangle mode. A rectangle region where the first value pair specifies the upper-left corner and the second value pair specifies the lower-right corner such that both corners are inclusive. For each corner, the first value shall be the horizontal position and the second value shall be the vertical position. The indexing shall begin at 0, and shall use the reference grid defined in the JPEG 2000 Core coding system. |
+|                 | 01            | Range mode. A range of values where the first value specifies the start index and the second value specifies the last index, both inclusive.                                                                                                                                                                                                                                                                                       |
+|                 | 10            | Index mode. Specifies single value(s).                                                                                                                                                                                                                                                                                                                                                                                             |
+|                 | 11            | Max mode. Specifies the maximum value.                                                                                                                                                                                                                                                                                                                                                                                             |
+| 5, 6            | 00            | Izoi <sup>i</sup> uses 8-bit integer                                                                                                                                                                                                                                                                                                                                                                                               |
+|                 | 01            | Izoi <sup>i</sup> uses 16-bit integer                                                                                                                                                                                                                                                                                                                                                                                              |
+|                 | 10            | Izoi <sup>i</sup> uses 32-bit integer                                                                                                                                                                                                                                                                                                                                                                                              |
+|                 | 11            | Izoi <sup>i</sup> uses 64-bit integer                                                                                                                                                                                                                                                                                                                                                                                              |
+| 7, 8            | 00            | Izoi <sup>i</sup> is described in one dimension                                                                                                                                                                                                                                                                                                                                                                                    |
+|                 | 10            | Izoi <sup>i</sup> is described in two dimensions                                                                                                                                                                                                                                                                                                                                                                                   |
+|                 | 01            | Izoi <sup>i</sup> is described in three dimensions                                                                                                                                                                                                                                                                                                                                                                                 |
+| 9               | 0             | Offset with lengths mode is not used                                                                                                                                                                                                                                                                                                                                                                                               |
+|                 | 1             | Offset with lengths mode is used: Specifies the initial offset with lengths of contiguous bytes that follows. The existence of this flag shall override the modes specified in bits 3 and 4.                                                                                                                                                                                                                                       |
+|                 |               | All other values are reserved                                                                                                                                                                                                                                                                                                                                                                                                      |
+
+When TRLCP tags are used, their size is defined by P<sub>TRLCP</sub> as specified in Table 4. In this case, bits 5 and 6 of the M<sub>ZOI</sub> parameter are overridden.
+
+The Offset with lengths mode can be used to efficiently represent a series of consecutive segments, for example, a series of consecutive byte ranges. The first value specifies the initial offset, the following values specify the lengths of each consecutive segment. If this field is used to represent n segments, then N<sub>ZOI</sub> should be set to n + 1.
+
+5.8 Protection method template syntax (T)
+
+5.8.1 General
+
+Protection method templates contain parameters for specific JPSEC tools described in 5.6.1. For example, they are used in JPSEC normative tools described in 5.6.2. Also, they can be used in JPSEC non-normative tools described in 5.6.3. There are three types of protection method templates: decryption template, authentication template, and hash template. The template used by a JPSEC normative tool is specified by its ID as shown in Table 6 and again here in Table 21 with references to the appropriate clauses where they are defined.
+
+As described in 5.6.2, the protection method template T together with a JPSEC tool's processing domain PD, granularity G, and value list V describe how a JPSEC tool is applied.
+
+Table 21 – Template ID values (ID<sub>T</sub>)
+
+| Values | Protection method template                        |
+|--------|---------------------------------------------------|
+| 0      | Reserved                                          |
+| 1      | Decryption template. See 5.8.2.                   |
+| 2      | Authentication template. See 5.8.3.               |
+| 3      | Hash template. See 5.8.4.                         |
+| 4      | NULL tool                                         |
+|        | All other values are reserved for ITU-T   ISO use |
+
+5.8.2 Decryption template ( $T = T_{\text{decry}}$ , if  $T_{\text{type}} = 0$  and  $ID = 1$ )
+
+The decryption template,  $T_{\text{decry}}$ , is used to communicate to the decryptor, how to decrypt the received codestream. Figure 23 shows the decryption template syntax. Table 22 shows the sizes and values of the symbols and parameters for the decryption template.
+
+![Figure 23: Decryption template syntax diagram. It shows a horizontal sequence of three fields: ME_decry (Marker Emulation flag), CT_decry (Cipher type), and CP_decry (Cipher parameter). The ME_decry and CP_decry fields are shaded with diagonal lines, while CT_decry is not. Below the diagram is the label T.807(23)_F23.](6629e8a87e7552e2454b7c3e9f6d73a0_img.jpg)
+
+Figure 23: Decryption template syntax diagram. It shows a horizontal sequence of three fields: ME\_decry (Marker Emulation flag), CT\_decry (Cipher type), and CP\_decry (Cipher parameter). The ME\_decry and CP\_decry fields are shaded with diagonal lines, while CT\_decry is not. Below the diagram is the label T.807(23)\_F23.
+
+Figure 23 – Decryption template syntax
+
+- ME<sub>decry</sub>:** False marker emulation flag indicates whether a false marker emulation has occurred in the encrypted data. A false marker emulation can adversely affect compliance with JPEG 2000 Core coding system decoders. This field uses the FBAS structure.
+- CT<sub>decry</sub>:** Cipher type identification.
+- CP<sub>decry</sub>:** Cipher parameter.
+
+Table 22 – Decryption template parameter values
+
+| Parameter           | Size (bits)      | Values                                                                                                                                                   |
+|---------------------|------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------|
+| ME <sub>decry</sub> | 8 + 8 * n (FBAS) | Table 23                                                                                                                                                 |
+| CT <sub>decry</sub> | 16               | Table 24                                                                                                                                                 |
+| CP <sub>decry</sub> | Variable         | If CT <sub>decry</sub> < 0x6000, see 5.8.2.1.<br>If 0x6000 ≤ CT <sub>decry</sub> < 0xC000, see 5.8.2.2.<br>If CT <sub>decry</sub> ≥ 0xC000, see 5.8.2.3. |
+
+Table 23 – Marker emulation flag values (ME<sub>decry</sub>)
+
+| Values    | Method type                                              |
+|-----------|----------------------------------------------------------|
+| 01xx xxxx | Encrypted data does not contain a false marker emulation |
+| 00xx xxxx | Otherwise                                                |
+|           | All other values are reserved for ITU-T   ISO use        |
+
+The default value of the marker emulation flag is 0. This flag can be set to 1 to indicate that the JPSEC encrypted data does not contain a false marker emulation. A JPSEC creator can choose to leave this flag at its default value of 0.
+
+Table 24 – Cipher identifier values (CT<sub>decry</sub>)
+
+| Values            | Cipher type                      |
+|-------------------|----------------------------------|
+| 0 ... 0x5FFF      | Block cipher (see Table 25)      |
+| 0x6000 ... 0xBFFF | Stream cipher (see Table 26)     |
+| 0xC000 ... 0xFFFF | Asymmetric cipher (see Table 27) |
+
+Table 25 – Block cipher identifier values (CT<sub>decry</sub>)
+
+| Values | Cipher type                                       |
+|--------|---------------------------------------------------|
+| 0x0000 | NULL (no encryption)                              |
+| 0x0001 | AES (ISO/IEC 18033-3)                             |
+| 0x0002 | TDEA (ISO/IEC 18033-3)                            |
+| 0x0003 | MISTY1 (ISO/IEC 18033-3)                          |
+| 0x0004 | Camellia (ISO/IEC 18033-3)                        |
+| 0x0005 | CAST-128 (ISO/IEC 18033-3)                        |
+| 0x0006 | SEED (ISO/IEC 18033-3)                            |
+|        | All other values are reserved for ITU-T   ISO use |
+
+Table 26 – Stream cipher identifier values (CT<sub>decry</sub>)
+
+| Values                                            | Cipher type              |
+|---------------------------------------------------|--------------------------|
+| 0x6000                                            | SNOW 2 (ISO/IEC 18033-4) |
+| All other values are reserved for ITU-T   ISO use |                          |
+
+Table 27 – Asymmetric cipher identifier values (CT<sub>decry</sub>)
+
+| Values                                            | Cipher type                |
+|---------------------------------------------------|----------------------------|
+| 0xC000                                            | RSA-OAEP (ISO/IEC 18033-2) |
+| All other values are reserved for ITU-T   ISO use |                            |
+
+### 5.8.2.1 Block cipher template (CP<sub>decry</sub> for block ciphers)
+
+The block cipher template is used to communicate to the block decryptor how to decrypt the received codestream. Figure 24 shows the block cipher mode, padding mode, block size and key information.
+
+Some block cipher modes can use initialization vectors. For these modes, the tool's initialization vectors are specified using the tool's granularity field (G) described in 5.10 and Value list field (V) described in 5.11. Specifically, initialization vectors are only used for modes with ID  $M_{bc} > 0x80$ , for instance CBC, CFB, OFB, CTR. In the CTR case, it is not really an IV but a *counter*. The size of the initialization vector specified in the Value list V shall be set to the block size  $SIZ_{bc}$ .
+
+![Figure 24: Block cipher template syntax diagram. It shows a sequence of bit fields: M_bc (6 bits, labeled 5 4 3 2 1 0), P_bc (2 bits, labeled 1 0), SIZ_bc (8 bits, labeled 7 6 5 4 3 2 1 0), and KT_bc (variable length, indicated by a hatched box).](f1091147d93cee4dfa88498610e395a7_img.jpg)
+
+T.807(23)\_F24
+
+Figure 24: Block cipher template syntax diagram. It shows a sequence of bit fields: M\_bc (6 bits, labeled 5 4 3 2 1 0), P\_bc (2 bits, labeled 1 0), SIZ\_bc (8 bits, labeled 7 6 5 4 3 2 1 0), and KT\_bc (variable length, indicated by a hatched box).
+
+Figure 24 – Block cipher template syntax
+
+- M<sub>bc</sub>:** Block cipher mode. The first bit indicates the use of initialization vectors with this tool. If  $M_{bc} < 0x8$ , IVs are not used, otherwise one or more IV values are required for the mode.
+- P<sub>bc</sub>:** Padding mode.
+- SIZ<sub>bc</sub>:** Size of block in Bytes.
+- KT<sub>bc</sub>:** Key template (see 5.8.5). It holds information on the keys used by the block cipher.
+
+Table 28 – Block cipher template values
+
+| Parameter         | Size (bits) | Values    |
+|-------------------|-------------|-----------|
+| M <sub>bc</sub>   | 6           | Table 29  |
+| P <sub>bc</sub>   | 2           | Table 30  |
+| SIZ <sub>bc</sub> | 8           | 1 ... 256 |
+| KT <sub>bc</sub>  | Variable    | See 5.8.5 |
+
+Table 29 – Block cipher mode values (M<sub>bc</sub>)
+
+| Values  | Mode type                                                      |
+|---------|----------------------------------------------------------------|
+| 0       | Reserved                                                       |
+| 0x xxxx | Modes which are used without IV                                |
+| 1x xxxx | Modes which are used with an IV                                |
+| x0 xxxx | P <sub>bc</sub> bits are not padded, use 00                    |
+| x1 xxxx | P <sub>bc</sub> bits are padded with value defined in Table 30 |
+| 0x 0001 | ECB (ISO/IEC 10116)                                            |
+| 1x 0010 | CBC (ISO/IEC 10116)                                            |
+| 1x 0011 | CFB (ISO/IEC 10116)                                            |
+| 1x 0100 | OFB (ISO/IEC 10116)                                            |
+| 1x 0101 | CTR (ISO/IEC 18033-2)                                          |
+|         | All other values are reserved for ITU-T   ISO use              |
+
+NOTE 1 – Careful implementations are required for all modes, because improper implementations can lead to vulnerabilities. Note that even correct implementation of ECB has information leakage when identical blocks appear. Guidelines are contained in ISO/IEC 10116.
+
+NOTE 2 – Values in Table 30 only apply when M<sub>bc</sub> in Table 29 specifies that Bits are padded. When bits are not padded, P<sub>bc</sub> shall be set to 00.
+
+Table 30 – Padding mode for block cipher (P<sub>bc</sub>)
+
+| Values | Padding type                                      |
+|--------|---------------------------------------------------|
+| 00     | Ciphertext stealing (RFC 2040)                    |
+| 01     | PKCS#7-padding (PKCS#7)                           |
+|        | All other values are reserved for ITU-T   ISO use |
+
+NOTE 3 – When using padding, careful system design should be used to avoid potential security vulnerabilities, such as chosen cipher attacks.
+
+5.8.2.2 Stream cipher template (CP<sub>decry</sub> for stream ciphers)
+
+The stream cipher template is used to communicate to the stream decryptor how to decrypt the received codestream. Figure 25 shows the stream cipher template syntax. Table 31 shows the values of the stream cipher template.
+
+The stream cipher's initialization vectors are specified using the tool's granularity field (G) described in 5.10 and Value list field (V) described in 5.11. The size of the initialization vector specified in the Value list V shall be set to the key size defined in the key information template KT<sub>sc</sub>.
+
+![Diagram showing the stream cipher template syntax as a box labeled KT_sc with diagonal hatching.](ccfd5ed8d9795009e923e2a0cacbcd6e_img.jpg)
+
+T.807(23)\_F25
+
+Diagram showing the stream cipher template syntax as a box labeled KT\_sc with diagonal hatching.
+
+Figure 25 – Stream cipher template syntax
+
+KT<sub>sc</sub>: Key information template (see 5.8.5). It holds information on the keys used by the stream cipher.
+
+Table 31 – Stream cipher template values
+
+| Parameter        | Size (bits) | Values    |
+|------------------|-------------|-----------|
+| KT <sub>sc</sub> | Variable    | See 5.8.5 |
+
+5.8.2.3 Asymmetric cipher template (CP<sub>decry</sub> for asymmetric ciphers)
+
+The asymmetric cipher template is used to communicate to the asymmetric cipher decryptor, how to decrypt the received codestream. Figure 26 shows the asymmetric cipher template syntax. Table 32 shows the values of the asymmetric cipher template.
+
+For tools that use the asymmetric cipher template, the tool's granularity field (G) specifies the granularity with which the cipher is applied. However, the Value list field (V) is not used to represent any values. Thus, the number of elements ( $N_V$ ) in the Value list field shall be set to 0.
+
+![Figure 26: Asymmetric cipher template syntax diagram. A rectangle with diagonal hatching contains the text 'KT_sy'. Below the rectangle is the label 'T.807(23)_F26'.](95e259e8cb3519025066052af263f8c0_img.jpg)
+
+The diagram shows a single rectangular block with diagonal hatching lines. Inside the block is the text *KT<sub>sy</sub>*. Below the block is the reference label T.807(23)\_F26.
+
+Figure 26: Asymmetric cipher template syntax diagram. A rectangle with diagonal hatching contains the text 'KT\_sy'. Below the rectangle is the label 'T.807(23)\_F26'.
+
+Figure 26 – Asymmetric cipher template syntax
+
+**KT<sub>sy</sub>**: Key information template (see 5.8.5). It holds information on the keys used by the asymmetric cipher.
+
+Table 32 – Asymmetric cipher template values
+
+| Parameter        | Size (bits) | Values    |
+|------------------|-------------|-----------|
+| KT <sub>sy</sub> | Variable    | See 5.8.5 |
+
+### 5.8.3 Authentication template (T = T<sub>auth</sub>, if T<sub>type</sub> = 0 and ID = 2)
+
+The authentication template, T<sub>auth</sub>, is used to communicate to the verifier, how to verify the authenticity of received codestream. There are three general classes of authentication methods: hash-based authentication, cipher-based authentication, and digital signatures. Both hash-based and cipher-based authentication methods are also generally referred to as message authentication codes (MACs), and their computed values which are used for authentication are generally referred to as MAC values. The authentication template syntax is shown in Figure 27, and Table 33 shows the sizes and values of the symbols and parameters for the authentication template.
+
+In many security applications, authentication is the most important security service. Even when confidentiality is the targeted security service, it should be augmented by authentication to prevent attacks. In particular, it is recommended to authenticate parts of the SEC marker segment. In addition, the authentication shall be performed on both the authentication template parameters (T<sub>auth</sub>) and the message to authenticate. Specifically, the zone of influence shall specify that both the content and the authentication template parameters (T<sub>auth</sub>) are to be authenticated.
+
+![Figure 27: Authentication template syntax diagram. A rectangle is divided into two parts. The left part is labeled 'M_auth' and the right part is labeled 'P_auth'. Below the rectangle is the label 'T.807(23)_F27'.](f24f909d837b5476783e1bbea2dfc143_img.jpg)
+
+The diagram shows a rectangular structure divided into two adjacent sections. The left section is a narrow vertical box labeled *M<sub>auth</sub>*. The right section is a larger box with diagonal hatching labeled *P<sub>auth</sub>*. Below the entire structure is the reference label T.807(23)\_F27.
+
+Figure 27: Authentication template syntax diagram. A rectangle is divided into two parts. The left part is labeled 'M\_auth' and the right part is labeled 'P\_auth'. Below the rectangle is the label 'T.807(23)\_F27'.
+
+Figure 27 – Authentication template syntax
+
+**M<sub>auth</sub>**: Authentication method.  
+**P<sub>auth</sub>**: Authentication parameters.
+
+Table 33 – Authentication template parameter values
+
+| Parameter         | Size (bits) | Values                                                                                                                  |
+|-------------------|-------------|-------------------------------------------------------------------------------------------------------------------------|
+| M <sub>auth</sub> | 8           | Table 34                                                                                                                |
+| P <sub>auth</sub> | Variable    | If M <sub>auth</sub> = 0, see 5.8.3.1<br>If M <sub>auth</sub> = 1, see 5.8.3.2<br>If M <sub>auth</sub> = 2, see 5.8.3.3 |
+
+Table 34 – Authentication methods (M<sub>auth</sub>)
+
+| Values                                            | Method            |
+|---------------------------------------------------|-------------------|
+| 0                                                 | Hash-based MAC    |
+| 1                                                 | Cipher-based MAC  |
+| 2                                                 | Digital Signature |
+| All other values are reserved for ITU-T   ISO use |                   |
+
+5.8.3.1 Hash-based authentication (P<sub>auth</sub> for hash-based MAC)
+
+The hash-based authentication MAC is used to communicate to the verifier how to verify the authenticity of the received codestream. Figure 28 shows the hash-based authentication template syntax and Table 35 shows the parameter values.
+
+The MAC values are specified using the tool's granularity field (G) described in 5.10 and Value list field (V) described in 5.11. The size of the MAC value specified in the value list V shall be set to the MAC size defined by SIZ<sub>HMAC</sub>.
+
+![Figure 28: Hash-based authentication template syntax diagram. It shows a sequence of four fields: M_HMAC, H_HMAC, KT_HMAC, and SIZ_HMAC. The KT_HMAC field is shaded with diagonal lines. Below the diagram is the label T.807(23)_F28.](838c31609fac483fa2c01c7896a2fd6d_img.jpg)
+
+T.807(23)\_F28
+
+Figure 28: Hash-based authentication template syntax diagram. It shows a sequence of four fields: M\_HMAC, H\_HMAC, KT\_HMAC, and SIZ\_HMAC. The KT\_HMAC field is shaded with diagonal lines. Below the diagram is the label T.807(23)\_F28.
+
+Figure 28 – Hash-based authentication template
+
+**M<sub>HMAC</sub>**: Hash-based authentication method identifier.
+
+**H<sub>HMAC</sub>**: Hash identifier.
+
+**KT<sub>HMAC</sub>**: Key template.
+
+**SIZ<sub>HMAC</sub>**: Size of MAC (bits).
+
+Table 35 – Hash-based authentication template parameter values
+
+| Parameter           | Size (bits) | Values      |
+|---------------------|-------------|-------------|
+| M <sub>HMAC</sub>   | 8           | Table 36    |
+| H <sub>HMAC</sub>   | 8           | Table 37    |
+| KT <sub>HMAC</sub>  | Variable    | See 5.8.5   |
+| SIZ <sub>HMAC</sub> | 16          | 0 ... 65535 |
+
+Table 36 – Hash-based authentication method identifier (M<sub>HMAC</sub>)
+
+| Values | Hash-based authentication method                  |
+|--------|---------------------------------------------------|
+| 0      | Reserved                                          |
+| 1      | HMAC (ISO/IEC 9797-2)                             |
+|        | All other values are reserved for ITU-T   ISO use |
+
+Table 37 – Hash function identifier ( $H_{\text{HMAC}}$ )
+
+| Values | Hash function                                     |
+|--------|---------------------------------------------------|
+| 0      | Reserved                                          |
+| 1      | SHA-1 (ISO/IEC 10118-3)                           |
+| 2      | RIPEMD-128 (ISO/IEC 10118-3)                      |
+| 3      | RIPEMD-160 (ISO/IEC 10118-3)                      |
+| 4      | MASH-1 (ISO/IEC 10118-4)                          |
+| 5      | MASH-2 (ISO/IEC 10118-4)                          |
+| 6      | SHA-224 (ISO/IEC 10118-3)                         |
+| 7      | SHA-256 (ISO/IEC 10118-3)                         |
+| 8      | SHA-384 (ISO/IEC 10118-3)                         |
+| 9      | SHA-512 (ISO/IEC 10118-3)                         |
+| 10     | WHIRLPOOL (ISO/IEC 10118-3)                       |
+|        | All other values are reserved for ITU-T   ISO use |
+
+Note that if the  $SIZ_{\text{HMAC}}$  is less than the nominal size of the hash, then it is the truncated version corresponding to the first  $SIZ_{\text{HMAC}}$  bits of the hash.
+
+5.8.3.2 Cipher-based authentication template ( $P_{\text{auth}}$  for cipher-based MAC)
+
+The cipher-based authentication MAC is used to communicate to the verifier how to verify the authenticity of the received codestream. Figure 29 is its template and Table 38 shows the key size and keyed hash. An example cipher based authentication scheme is CBC-MAC. In these block-cipher techniques for authentication, the initialization vector is one blocksize in length and of value 0. The blocksize is the default for the block cipher. Note that if the  $SIZ_{\text{CMAC}}$  is less than the nominal size of the cipher-based authentication MAC, then it is the truncated version corresponding to the first  $SIZ_{\text{CMAC}}$  bits of the MAC.
+
+Note that, if the number of data bits is not a multiple of the cipher block size, then the final input block will be a partial block of data, left justified, with zeroes appended to form a full cipher block. Also note that CBC-MAC shall only be applied to data with a fixed and known length.
+
+The MAC values are specified using the tool's granularity field (G) described in 5.10 and value list field (V) described in 5.11. The size of the MAC value specified in the value list V shall be set to the MAC size defined by  $SIZ_{\text{CMAC}}$ .
+
+![Figure 29: Cipher-based authentication template syntax diagram. It shows a sequence of four fields: CA_CMAC, C_CMAC, KT_CMAC, and SIZ_CMAC. CA_CMAC and C_CMAC are narrow vertical rectangles. KT_CMAC is a wider rectangle with diagonal hatching. SIZ_CMAC is a narrow vertical rectangle. Below the diagram is the label T.807(23)_F29.](bc9d0c0b02cbe628b1b6548cc1107734_img.jpg)
+
+Figure 29: Cipher-based authentication template syntax diagram. It shows a sequence of four fields: CA\_CMAC, C\_CMAC, KT\_CMAC, and SIZ\_CMAC. CA\_CMAC and C\_CMAC are narrow vertical rectangles. KT\_CMAC is a wider rectangle with diagonal hatching. SIZ\_CMAC is a narrow vertical rectangle. Below the diagram is the label T.807(23)\_F29.
+
+Figure 29 – Cipher-based authentication template syntax
+
+- $CA_{\text{CMAC}}$ : Cipher-based authentication method.
+- $C_{\text{CMAC}}$ : Block-cipher identifier value.
+- $KT_{\text{CMAC}}$ : Key template.
+- $SIZ_{\text{CMAC}}$ : Size of MAC (bits).
+
+Table 38 – MAC template values
+
+| Parameter           | Size (bits) | Values      |
+|---------------------|-------------|-------------|
+| $CA_{\text{CMAC}}$  | 8           | Table 39    |
+| $C_{\text{CMAC}}$   | 8           | Table 25    |
+| $KT_{\text{CMAC}}$  | Variable    | See 5.8.5   |
+| $SIZ_{\text{CMAC}}$ | 16          | 0 ... 65535 |
+
+Table 39 – Cipher-based authentication method (C<sub>CMAC</sub>)
+
+| Values | Method                                            |
+|--------|---------------------------------------------------|
+| 0      | CBC-MAC MAC Algorithm 1 (ISO/IEC 9797-1)          |
+| 1      | CBC-MAC MAC Algorithm 2 (ISO/IEC 9797-1)          |
+| 2      | CBC-MAC MAC Algorithm 3 (ISO/IEC 9797-1)          |
+| 3      | CBC-MAC MAC Algorithm 4 (ISO/IEC 9797-1)          |
+|        | All other values are reserved for ITU-T   ISO use |
+
+5.8.3.3 Digital signature template (P<sub>auth</sub> for digital signatures)
+
+The digital signature is used to communicate to the verifier how to verify the authenticity of received codestream, as well as verifying the identity of the sender for both identity and non-repudiation purposes. Figure 30 defines its template and Table 40 lists the values.
+
+The digital signatures are specified using the tool's granularity field (G) described in 5.10 and value list field (V) described in 5.11. The size of the digital signatures value specified in the value list V shall be set to accommodate the size defined by SIZ<sub>DS</sub>. Because the value list size is represented by bytes rather than bits, its size should be the minimum number of bytes that can accommodate SIZ<sub>DS</sub>. Each value should be represented with the least significant bits, and the extra MSB bits shall be set to 0.
+
+![Figure 30: Digital signature template syntax diagram. It shows a sequence of four fields: M_DS, H_DS, KT_DS, and SIZ_DS. M_DS and H_DS are small boxes. KT_DS is a larger box with diagonal hatching. SIZ_DS is a box with a small vertical line above it. Below the diagram is the label T.807_F30.](a5184899f915014fa38608754efcc9c7_img.jpg)
+
+Figure 30: Digital signature template syntax diagram. It shows a sequence of four fields: M\_DS, H\_DS, KT\_DS, and SIZ\_DS. M\_DS and H\_DS are small boxes. KT\_DS is a larger box with diagonal hatching. SIZ\_DS is a box with a small vertical line above it. Below the diagram is the label T.807\_F30.
+
+Figure 30 – Digital signature template syntax
+
+- M<sub>DSI</sub>: Digital signature method.
+- H<sub>DS</sub>: Hash function.
+- K<sub>TDS</sub>: Key template (see 5.8.5). It holds all the information related to the public key or the certificate required to verify the digital signature.
+- SIZ<sub>DS</sub>: Size of digital signature (bits).
+
+Table 40 – Digital signature template values
+
+| Parameter         | Size (bits) | Values      |
+|-------------------|-------------|-------------|
+| M <sub>DS</sub>   | 8           | Table 41    |
+| H <sub>DS</sub>   | 8           | Table 37    |
+| K <sub>TDS</sub>  | Variable    | See 5.8.5   |
+| SIZ <sub>DS</sub> | 16          | 0 ... 65535 |
+
+Table 41 – Digital signature methods (M<sub>DS</sub>)
+
+| Values | Method                                            |
+|--------|---------------------------------------------------|
+| 1      | RSA (ISO/IEC 14888-2)                             |
+| 2      | Rabin (ISO/IEC 14888-2)                           |
+| 3      | DSA (ISO/IEC 14888-3)                             |
+| 4      | ECDSA (ISO/IEC 14888-3)                           |
+|        | All other values are reserved for ITU-T   ISO use |
+
+5.8.4 Hash template (T = T<sub>hash</sub>, if T<sub>type</sub> = 0 and ID = 3)
+
+The hash template, T<sub>hash</sub> as shown in Figure 31, is used to communicate the parameters used to compute the hash. Table 42 shows the sizes and values of the symbols and parameters for hash template.
+
+Note that in contrast to the hash-based authentication template discussed in 5.8.3.1 which involves the use of a hash and a secret key, this hash template does not use a key. While this hash template can be used to detect an accidental error or accidental change to the data, it does not prevent malicious alteration of the data. In order to prevent malicious alteration
+
+of the data an authentication template should be used, since the secret key used by the authentication template prevents the data from being altered without being discovered.
+
+The hash values are specified using the tool's granularity field (G) described in 5.10 and value list field (V) described in 5.11. The size of the hash value specified in the value list V shall be set to the hash value size defined by  $SIZ_{hash}$ .
+
+![Figure 31: Hash template syntax diagram. It shows a vertical rectangle divided into two equal horizontal sections. The top section is labeled H_hash and the bottom section is labeled SIZ_hash. Below the rectangle is the label T.807(23)_F31.](8e80de0cac529b2c3775d677c5203133_img.jpg)
+
+Figure 31: Hash template syntax diagram. It shows a vertical rectangle divided into two equal horizontal sections. The top section is labeled H\_hash and the bottom section is labeled SIZ\_hash. Below the rectangle is the label T.807(23)\_F31.
+
+Figure 31 – Hash template syntax
+
+**H<sub>hash</sub>**: Hash function identifier.
+
+**SIZ<sub>hash</sub>**: Size of hash value (bytes).
+
+Table 42 – Hash template parameter values
+
+| Parameter           | Size (bits) | Values    |
+|---------------------|-------------|-----------|
+| H <sub>hash</sub>   | 8           | Table 37  |
+| SIZ <sub>hash</sub> | 8           | 0 ... 255 |
+
+5.8.5 Key information template (KT)
+
+The key information template is used to communicate key information. Figure 32 defines its template and Table 43 lists the values.
+
+![Figure 32: Key information template syntax diagram. It shows a horizontal rectangle divided into four equal vertical sections. The first section is labeled LK_KT, the second is labeled KID_KT, the third is labeled G_KT, and the fourth is labeled V_KT. The V_KT section is shaded with diagonal lines. Below the rectangle is the label T.807(23)_F32.](822e033872d5ab16e861571f47b81ba7_img.jpg)
+
+Figure 32: Key information template syntax diagram. It shows a horizontal rectangle divided into four equal vertical sections. The first section is labeled LK\_KT, the second is labeled KID\_KT, the third is labeled G\_KT, and the fourth is labeled V\_KT. The V\_KT section is shaded with diagonal lines. Below the rectangle is the label T.807(23)\_F32.
+
+Figure 32 – Key information template syntax
+
+**LK<sub>KT</sub>**: Length of key in bits.
+
+**KID<sub>KT</sub>**: Key information identifier. It indicates the meaning of the values in the value list V<sub>KT</sub>. In the decryption template, this value should be set to 2 (URI to retrieve the secret key). In the case of digital signature, the value of this field is free.
+
+**G<sub>KT</sub>**: Granularity field to represent the granularity with which the key information changes.
+
+**V<sub>KT</sub>**: Value list field to represent the changing list of key information.
+
+Note that in the case of a secret key (decryption template), the public key and certificate have no meanings: the key template should hold some information on the location of the key (e.g., URI).
+
+The key information can be represented with one or more values using the tool's granularity field (G<sub>KT</sub>) described in 5.10 and value list field (V<sub>KT</sub>) described in 5.11. The two fields (G<sub>KT</sub> and V<sub>KT</sub>) together determine how the key values in the value list (V<sub>KT</sub>) are applied to the protected image data, as described in 5.10 and 5.11.
+
+The key information in the value list can take one the forms specified in Table 44. If KID<sub>KT</sub> = 1, then each value is specified with the ITU-T X.509 certificate template described in 5.8.5.1. If KID<sub>KT</sub> = 2, then each value is specified with a URI for the certificate or secret key.
+
+Table 43 – Key template values
+
+| Parameter         | Size (bits) | Values      |
+|-------------------|-------------|-------------|
+| LK <sub>KT</sub>  | 16          | 1 ... 65535 |
+| KID <sub>KT</sub> | 8           | Table 44    |
+| G <sub>KT</sub>   | 24          | See 5.10    |
+| V <sub>KT</sub>   | Variable    | See 5.11    |
+
+Table 44 – Key information identifier values ( $KID_{KT}$ )
+
+| Values | Key information identifier                        |
+|--------|---------------------------------------------------|
+| 0      | Reserved                                          |
+| 1      | ITU-T X.509 certificate (ISO/IEC 9594-8)          |
+| 2      | URI for certificate or secret key                 |
+|        | All other values are reserved for ITU-T   ISO use |
+
+### 5.8.5.1 ITU-T X.509 certificate template
+
+The ITU-T X.509 certificate template is shown in Figure 33 and Table 45 lists the values.
+
+![Figure 33: ITU-T X.509 certificate syntax diagram. It consists of three adjacent rectangular blocks. The first block is narrow, labeled 'ER_KT' vertically on its left side. The second block is labeled 'LCER_KT'. The third block is larger and filled with diagonal hatching, labeled 'CER_KT'. Below the diagram is the reference 'T.807(23)_F33'.](b44f89b176c971c7dd264c07bfef2c2a_img.jpg)
+
+Figure 33: ITU-T X.509 certificate syntax diagram. It consists of three adjacent rectangular blocks. The first block is narrow, labeled 'ER\_KT' vertically on its left side. The second block is labeled 'LCER\_KT'. The third block is larger and filled with diagonal hatching, labeled 'CER\_KT'. Below the diagram is the reference 'T.807(23)\_F33'.
+
+Figure 33 – ITU-T X.509 certificate syntax
+
+- $ER_{KT}$** : Encoding rule for ITU-T X.509 certificate.
+- $LCER_{KT}$** : Length of ITU-T X.509 certificate ( $CER_{KT}$ ) in bytes.
+- $CER_{KT}$** : ITU-T X.509 certificate.
+
+Table 45 – ITU-T X.509 certificate values ( $KI_{KT}$  if  $KID_{KT} = 2$ )
+
+| Parameter   | Size (bits) | Values                   |
+|-------------|-------------|--------------------------|
+| $ER_{KT}$   | 8           | 0 ... 255 (see Table 46) |
+| $LCER_{KT}$ | 16          | 1 ... 65535              |
+| $CER_{KT}$  | Variable    | –                        |
+
+Table 46 – Encoding rule values ( $ER_{KT}$ )
+
+| Values | Encoding rule identifier                          |
+|--------|---------------------------------------------------|
+| 0      | Reserved                                          |
+| 1      | DER (RFC 3217)                                    |
+| 2      | BER (RFC 3394)                                    |
+|        | All other values are reserved for ITU-T   ISO use |
+
+### 5.9 Processing domain syntax (PD)
+
+The processing domain syntax, as shown in Figure 34, is used to indicate on which domain the JPSEC tool is applied. The possible domains include pixel domain, wavelet coefficient domain, quantized wavelet coefficient domain and codestream domain.
+
+![Figure 34: Processing domain syntax diagram. It consists of two adjacent rectangular blocks, both filled with diagonal hatching. The first block is labeled 'PD' and the second is labeled 'F_PD'. Below the diagram is the reference 'T.807(23)_F34'.](cdd9c57c9c578160002ead5cdaef414d_img.jpg)
+
+Figure 34: Processing domain syntax diagram. It consists of two adjacent rectangular blocks, both filled with diagonal hatching. The first block is labeled 'PD' and the second is labeled 'F\_PD'. Below the diagram is the reference 'T.807(23)\_F34'.
+
+Figure 34 – Processing domain syntax
+
+- PD**: Processing domain. This field uses the FBAS structure.
+- $F_{PD}$** : Processing domain field to provide further detailed information about the processing domain. This field uses the FBAS structure.
+
+Table 47 – Processing domain parameters
+
+| Parameter       | Size (bits)     | Values                                                                                                                       |
+|-----------------|-----------------|------------------------------------------------------------------------------------------------------------------------------|
+| PD              | Variable (FBAS) | See Table 48                                                                                                                 |
+| F <sub>PD</sub> | Variable (FBAS) | In wavelet coefficient domain and quantized wavelet coefficient domain, see Table 49.<br>In codestream domain, see Table 50. |
+
+Table 48 – Processing Domain (PD) parameter values
+
+| FBAS bit number | Values | Semantics                                                                                        |
+|-----------------|--------|--------------------------------------------------------------------------------------------------|
+| 1               | 1      | Pixel domain. Protection method is applied on image pixels.                                      |
+|                 | 0      | Otherwise                                                                                        |
+| 2               | 1      | Wavelet coefficient domain. Protection method is applied on wavelet coefficients.                |
+|                 | 0      | Otherwise                                                                                        |
+| 3               | 1      | Quantized wavelet coefficient domain: Protection method applied on quantized wavelet coefficient |
+|                 | 0      | Otherwise                                                                                        |
+| 4               | 1      | Codestream domain: Protection method is applied on codestream generated from arithmetic coder.   |
+|                 | 0      | Otherwise                                                                                        |
+
+Note that the field PD shall have one and only bit set to 1, because each JPSEC tool is applicable to one domain only.
+
+In image pixel domain, wavelet coefficient domain and quantized wavelet coefficient domain, the two-dimensional data has to be transformed to one-dimensional in order to apply the security tools. This transformation shall be done by scanning the two-dimensional image data in the raster-scan order.
+
+Table 49 – Processing domain field (F<sub>PD</sub>) parameter values in wavelet coefficient domain and quantized wavelet coefficient domain
+
+| FBAS bit number | Value | Semantics                                            |
+|-----------------|-------|------------------------------------------------------|
+| 1               | 0     | Protection method is applied on sign bit             |
+|                 | 1     | Protection method is applied on most significant bit |
+
+Table 50 – Processing domain field (F<sub>PD</sub>) parameter values in codestream domain
+
+| FBAS bit number | Value | Semantics                                                          |
+|-----------------|-------|--------------------------------------------------------------------|
+| 1               | 0     | Protection method is applied on both packet header and packet body |
+|                 | 1     | Protection method is applied on packet body only                   |
+
+The field (F<sub>PD</sub>) is used to provide further information on processing domain. With different value of PD, this field (F<sub>PD</sub>) has different semantics. For instance, in wavelet coefficient domain and quantized wavelet coefficient domain, the first bit of F<sub>PD</sub> is used to indicate whether the JPSEC tool is applied on the most significant bit. In codestream domain, the first bit of F<sub>PD</sub> is used to indicate whether the JPSEC tool is applied on packet body only or both packet header and body; in the pixel domain, this field (F<sub>PD</sub>) is reserved.
+
+5.10 Granularity syntax (G)
+
+Granularity is used to indicate the unit of protection for each protection method. Table 53 defines possible granularities. Figure 35 shows the granularity syntax.
+
+![Figure 35: Granularity syntax diagram. It shows a box divided into two columns: 'PO' (Protection Object) and 'GL' (Granularity Level). A vertical line is positioned above the 'PO' column. Below the box, the text 'T.807(23)_F35' is present.](56680df276d8e8d21e5ed5c8e21527c6_img.jpg)
+
+T.807(23)\_F35
+
+Figure 35: Granularity syntax diagram. It shows a box divided into two columns: 'PO' (Protection Object) and 'GL' (Granularity Level). A vertical line is positioned above the 'PO' column. Below the box, the text 'T.807(23)\_F35' is present.
+
+Figure 35 – Granularity syntax
+
+PO: Processing order.  
+GL: Granularity level.
+
+Table 51 – Granularity parameter values (G)
+
+| Parameter | Size (bits) | Values       |
+|-----------|-------------|--------------|
+| PO        | 16          | See Table 52 |
+| GL        | 8           | See Table 53 |
+
+Table 52 – Processing order values (PO)
+
+| Values<br>MSB  LSB    | Processing order                                                            |
+|-----------------------|-----------------------------------------------------------------------------|
+| 0 000 000 000 000 000 | Order specified by Zone of Influence image-related parameters               |
+| 1 000 000 000 000 000 | Order specified by Zone of Influence non-image-related bitstream parameters |
+| 1 000 000 000 000 001 | Order specified by Zone of Influence non-image-related packet parameters    |
+| 0 000 001 010 011 100 | Tile-resolution-layer-component-precinct                                    |
+| 0 000 011 100 001 010 | Tile-component-precinct-resolution-layer                                    |
+| 0 000 010 001 011 100 | Tile-layer-resolution-component-precinct                                    |
+| 0 000 100 011 001 010 | Tile-precinct-component-resolution-layer                                    |
+| 0 000 001 100 011 100 | Tile-resolution-precinct-component-layer                                    |
+|                       | All other values are reserved                                               |
+
+Table 53 – Granularity level values (GL)
+
+| Values<br>MSB  LSB | Granularity                              |
+|--------------------|------------------------------------------|
+| 0000 0000          | Tile                                     |
+| 0000 0001          | Tile-part                                |
+| 0000 0010          | Component                                |
+| 0000 0011          | Resolution level                         |
+| 0000 0100          | Layer                                    |
+| 0000 0101          | Precinct                                 |
+| 0000 0110          | Packet                                   |
+| 0000 0111          | Sub-band                                 |
+| 0000 1000          | Code-block                               |
+| 0000 1001          | Total area identified in ZOI             |
+| 1000 0000          | Item identified in non-image-related ZOI |
+| 1000 0001          | Zone identified in non-image-related ZOI |
+|                    | All other values are reserved            |
+
+In order to process the entire zone specified by ZOI, the granularity level should be "zone identified in ZOI".
+
+5.11 Value list syntax (V)
+
+The Value list field, as shown in Figure 36, is used to specify values that change as the tool is applied and the granularity with which it changes. This is used to signal changing values such as keys, initialization vectors, MAC values, digital signatures, and hash values. The Value List field first specifies the number of values in the list and the size of each value. It then lists the values themselves.
+
+As discussed in 5.6.2, for JPSEC normative tools the Value list field represents a different parameter for each template. For the decryption template, it represents the initialization vectors IV<sub>bc</sub> or IV<sub>sc</sub> depending on whether a block cipher or stream cipher is used. For the authentication template, it represents the MAC value VAL<sub>MAC</sub> for hash-based and cipher-based authentication. For the digital signature template, it represents the digital signature SIG<sub>DS</sub>. For the hash template, it represents the hash value HV<sub>hash</sub>. Some usages of the templates do not require values to be specified, e.g., not all decryption modes use initialization vectors. In these cases, the Value list field should set N<sub>v</sub> and S<sub>v</sub> equal to zero so that
+
+the value list VL has no elements. If only a single value needs to be specified, e.g., if a single key is used throughout the image, then  $N_v$  will be set to one so that a single value is contained in the value list.
+
+![Figure 36: Value list field syntax diagram. It shows a rectangular field divided into three sections: N_v, S_v, and VL. Each section is filled with diagonal hatching. Below the diagram is the label T.807(23)_F36.](01e00200a536673d6cd0e6d8705047a0_img.jpg)
+
+Figure 36: Value list field syntax diagram. It shows a rectangular field divided into three sections: N\_v, S\_v, and VL. Each section is filled with diagonal hatching. Below the diagram is the label T.807(23)\_F36.
+
+Figure 36 – Value list field syntax
+
+- $N_v$ : Number of values in the value list VL, If  $N_v = 0$ , then the field terminates. This field uses RBAS structure.
+- $S_v$ : Size of each value in the value list VL in bytes. This field uses RBAS structure.
+- VL: List of values.
+
+Table 54 – Value list field (V) parameter values
+
+| Parameter | Size (bits)                                | Values                        |
+|-----------|--------------------------------------------|-------------------------------|
+| $N_v$     | $16 + 8 * n$ (RBAS)                        | $0 \dots (2^{15+7*n} - 1)$    |
+| $S_v$     | $8 + 8 * n$ (RBAS)                         | $0 \dots (2^{7+7*n} - 1)$     |
+| VL        | 0, if $N_v = 0$<br>$N_v * S_v$ , otherwise | N/A<br>Determined by template |
+
+5.12 Relationships among ZOI, Granularity (G) and Value List (VL)
+
+The ZOI, PO and GL are used together to ensure the unique behaviour of the applied JPSEC tool(s), regardless of the progress order of the JPEG 2000 codestream. In other words, the resulted signature, MAC values and encrypted codestream are independent of the progressive order of the JPEG 2000 codestream. The Zone of Influence (ZOI) specifies, in its entirety, the part of the JPEG 2000 codestream to be protected by the JPSEC tool; The Processing Order (PO), on the other hand, specifies the order in which the JPSEC tool processes the codestream; the Granularity Level (GL) specifies the protection units containing contiguous byte sequence in the re-ordered codestream. Finally, each protection unit corresponds to a value in the Value List (VL), in the order they appear in the re-ordered codestream. The relationship can be illustrated by one example, where the JPEG 2000 codestream has 1 tile, 3 resolution levels and 3 layers, and the number of components and precincts are not important. The progressive order is RLCP in original JPEG 2000 codestream, the Zone of Influence is resolution 0 and 1, and the Processing Order (PO) is TRLCp. Figure 37 and Figure 38 illustrate the re-ordering of the codestream and the mapping from each protection unit to the Value List (VL), when the Granularity Level (GL) is resolution and layer, respectively.
+
+![Figure 37: Granularity Level (GL) is resolution. This diagram shows the mapping from the original JPEG 2000 codestream to a re-ordered codestream and then to a Value List (VL). The 'JPEG 2000 codestream' column lists protection units R0 L0, R0 L1, R0 L2, R1 L0, R1 L1, R1 L2, R2 L0, R2 L1, and R2 L2. The 'Re-ordered codestream' column shows these units rearranged into a sequence: R0 L0, R0 L1, R1 L0, R1 L1, R2 L0, and R2 L1. The 'Value List (VL)' column lists corresponding values: Value 0, Value 1, Value 2, Value 3, Value 4, and Value 5. Arrows indicate the mapping from each unit in the re-ordered stream to its corresponding value in the Value List. The label T.807(23)_F37 is at the bottom right.](b4f6d3668f7e851eaff07ccf26001623_img.jpg)
+
+Figure 37: Granularity Level (GL) is resolution. This diagram shows the mapping from the original JPEG 2000 codestream to a re-ordered codestream and then to a Value List (VL). The 'JPEG 2000 codestream' column lists protection units R0 L0, R0 L1, R0 L2, R1 L0, R1 L1, R1 L2, R2 L0, R2 L1, and R2 L2. The 'Re-ordered codestream' column shows these units rearranged into a sequence: R0 L0, R0 L1, R1 L0, R1 L1, R2 L0, and R2 L1. The 'Value List (VL)' column lists corresponding values: Value 0, Value 1, Value 2, Value 3, Value 4, and Value 5. Arrows indicate the mapping from each unit in the re-ordered stream to its corresponding value in the Value List. The label T.807(23)\_F37 is at the bottom right.
+
+Figure 37 – Granularity Level (GL) is resolution
+
+![Diagram showing the mapping from JPEG 2000 codestream to Re-ordered codestream and then to Value List (VL). The JPEG 2000 codestream has layers R0 L0, R0 L1, R0 L2, R1 L0, R1 L1, R1 L2, R2 L0, R2 L1, and R2 L2. The Re-ordered codestream has layers R0 L0, R0 L1, R1 L0, R1 L1, R2 L0, and R2 L1. The Value List (VL) has values Value 0, Value 1, and Value 2. Arrows show the mapping: R0 L0 to Value 0, R0 L1 to Value 1, R1 L0 to Value 1, R1 L1 to Value 1, R2 L0 to Value 2, and R2 L1 to Value 2. R0 L2 and R1 L2 are not mapped to any value in the VL.](cc98b584f9b31fe69948e3fa65a3ba69_img.jpg)
+
+T.807(23)\_F38
+
+Diagram showing the mapping from JPEG 2000 codestream to Re-ordered codestream and then to Value List (VL). The JPEG 2000 codestream has layers R0 L0, R0 L1, R0 L2, R1 L0, R1 L1, R1 L2, R2 L0, R2 L1, and R2 L2. The Re-ordered codestream has layers R0 L0, R0 L1, R1 L0, R1 L1, R2 L0, and R2 L1. The Value List (VL) has values Value 0, Value 1, and Value 2. Arrows show the mapping: R0 L0 to Value 0, R0 L1 to Value 1, R1 L0 to Value 1, R1 L1 to Value 1, R2 L0 to Value 2, and R2 L1 to Value 2. R0 L2 and R1 L2 are not mapped to any value in the VL.
+
+Figure 38 – Granularity Level (GL) is layer
+
+NOTE – The re-ordered codestream is only used to generate the values in Value List (VL). The final JPSEC codestream will have the same progressive order as the original JPEG 2000 codestream.
+
+5.13 In-codestream security marker (INSEC)
+
+The in-codestream security marker (INSEC) provides an additional means to transmit security information. It is optional and is used in conjunction with the SEC security marker. Specifically, it is used in conjunction with a JPSEC non-normative tool.
+
+More precisely, the SEC marker is present in the main header and gives overall information about the JPSEC tools applied to protect the image. The INSEC marker is present in the bitstream data itself and gives additional or alternative parameters for the JPSEC non-normative tool identified by the tool instance index parameter. Therefore, the tool instance index in the INSEC marker shall correspond to one of the tool instance index in the main header.
+
+The INSEC marker segment can be placed in the bitstream data. It uses the fact that the arithmetic decoder in JPEG 2000 stops reading bytes from the bitstream when it encounters a termination marker (i.e., two bytes with a value greater than 0xFF8F).
+
+The information carried in the INSEC marker segment is relevant for the preceding or following secured codeblock(s), until another INSEC marker is found.
+
+Note that inclusion of INSEC markers results in a file that does not necessarily comply with the JPEG 2000 Core coding system. Note that some decoders can have difficulty in handling a marker in the middle of a packet. Insertion anywhere inside a packet will invalidate the length of the packet as indicated in the packet header. Also, there can be issues with encryption and INSEC markers due to:
+
+- a) lack of marker emulation restrictions on the encryption; and/or
+- b) inability to locate the marker itself in the presence of encryption.
+
+The syntax of the INSEC marker is defined in Figure 39.
+
+![Diagram showing the syntax of the INSEC marker. It consists of five fields: INSEC, L_INSEC, i, R, and AP. The fields i, R, and AP are shaded with diagonal lines. The diagram is labeled T.807(23)_F39.](981668c6be5792b778cccb1af38477e2_img.jpg)
+
+T.807(23)\_F39
+
+Diagram showing the syntax of the INSEC marker. It consists of five fields: INSEC, L\_INSEC, i, R, and AP. The fields i, R, and AP are shaded with diagonal lines. The diagram is labeled T.807(23)\_F39.
+
+Figure 39 – In-codestream security marker syntax
+
+- INSEC:** Marker code. Table 55 shows the sizes and values of the symbols and parameters for in-codestream security marker segment.
+- L<sub>INSEC</sub>:** Length of marker segment in bytes (not including the marker). Note that the INSEC marker segment should be byte-aligned.
+- i:** Tool instance index corresponding to one of the tool instance index parameters in the SEC marker segment and therefore identifying the instance of the JPSEC tool this INSEC marker is referring to. This field uses the RBAS structure.
+- R:** Relevance zone for the INSEC information. This field uses the FBAS structure.
+
+AP: Additional or alternative parameters for protection method. The encoder should always make sure that the encoder does not emulate a marker in this parameter.
+
+Table 55 – In-codestream security parameter values (INSEC)
+
+| Parameter | Size (bits)      | Values                               |
+|-----------|------------------|--------------------------------------|
+| INSEC     | 16               | 0xFF94                               |
+| LINSEC    | 16               | 2 ... (2 <sup>16</sup> – 1)          |
+| i         | 8 + 8 * n (RBAS) | 0 ... (2 <sup>7+7*n</sup> – 1)       |
+| R         | Variable (FBAS)  | See Table 56                         |
+| AP        | Variable         | Defined by user defined application. |
+
+Table 56 – Relevance zone values (R)
+
+| FBAS bit number | Values | Relevance zone        |
+|-----------------|--------|-----------------------|
+| 0               | 0      | Preceding code-blocks |
+|                 | 1      | Following code-blocks |
+
+Because INSEC is used in conjunction with JPSEC non-normative tools, the format of the additional or alternative parameters is defined by the tool itself which is identified by the tool ID. Specifically, JPSEC non-normative tools are defined by private JPSEC applications. Thus, the definition of these tools should include the INSEC usage if it is allowed.
+
+6 Normative-syntax usage examples (informative)
+
+6.1 ZOI examples
+
+6.1.1 to 6.1.6 contain examples that show how the Zone of Influence syntax can be used.
+
+In the examples, the superscripts used in Pzoi, Mzoi, and Izoi correspond to the index of the image-related and non-image-related items signalled by the BAS structure in DCzoi in the order they appear within the DCzoi.
+
+6.1.1 Example 1
+
+This clause shows the example that resolution levels more than 3 in the image region whose upper-left corner is (100, 120) and lower-right (180, 210) are influenced. In this example, 9 bytes are necessary.
+
+Table 57 – ZOI in example 1
+
+| Parameter         |                   |                   | Size (bits) | Value (in order)       | Derived meaning                                            |
+|-------------------|-------------------|-------------------|-------------|------------------------|------------------------------------------------------------|
+| NZzoi             |                   |                   | 8 (RBAS)    | 1                      | Number of Zones is one                                     |
+| Zone <sup>0</sup> | DCzoi             |                   | 1           | 0 <sub>b</sub>         | The byte aligned segment does not follow                   |
+|                   |                   |                   | 1           | 0 <sub>b</sub>         | Image related description class                            |
+|                   |                   |                   | 6           | 101000 <sub>b</sub>    | Image regions and resolution levels are specified in order |
+|                   | Pzoi <sup>1</sup> | Mzoi <sup>1</sup> | 1           | 0 <sub>b</sub>         | The byte aligned segment does not follow                   |
+|                   |                   |                   | 1           | 0 <sub>b</sub>         | The specified zones are influenced by the JPSEC tool       |
+|                   |                   |                   | 1           | 0 <sub>b</sub>         | Single item is specified                                   |
+|                   |                   |                   | 2           | 00 <sub>b</sub>        | Rectangle mode                                             |
+|                   |                   |                   | 2           | 00 <sub>b</sub>        | Izoi uses 8-bit integer                                    |
+|                   |                   |                   | 1           | 1 <sub>b</sub>         | Izoi is described in two dimensions                        |
+|                   |                   | Izoi <sup>1</sup> | 8           | 0110 0100 <sub>b</sub> | Xul is 100                                                 |
+|                   |                   |                   | 8           | 0111 1000 <sub>b</sub> | Yul is 120                                                 |
+|                   |                   |                   | 8           | 1011 0100 <sub>b</sub> | Xlr is 180                                                 |
+|                   |                   |                   | 8           | 1101 0010 <sub>b</sub> | Ylr is 210                                                 |
+|                   | Pzoi <sup>3</sup> | Mzoi <sup>3</sup> | 1           | 0 <sub>b</sub>         | The byte aligned segment does not follow                   |
+
+Table 57 – ZOI in example 1
+
+| Parameter |                   |  | Size (bits) | Value (in order)       | Derived meaning                                                                                                       |
+|-----------|-------------------|--|-------------|------------------------|-----------------------------------------------------------------------------------------------------------------------|
+|           |                   |  | 1           | 1 <sub>b</sub>         | The complement of the specified zones is influenced by the JPSEC tool                                                 |
+|           |                   |  | 1           | 0 <sub>b</sub>         | Single item is specified                                                                                              |
+|           |                   |  | 2           | 11 <sub>b</sub>        | Max mode                                                                                                              |
+|           |                   |  | 2           | 00 <sub>b</sub>        | Izoi uses 8-bit integer                                                                                               |
+|           |                   |  | 1           | 0 <sub>b</sub>         | Izoi is described in one dimension                                                                                    |
+|           | Izoi <sup>3</sup> |  | 8           | 0000 0010 <sub>b</sub> | Resolution levels ≤ 2 are specified. (i.e., Resolution levels > 3 are specified with Max mode and complement switch.) |
+
+### 6.1.2 Example 2
+
+This clause shows the example that the code-blocks whose upper-left corner's index is 5 and lower-right corner's index is 10 in the sub-band 1, in the resolution level 0 are influenced. In this example, 10 bytes are necessary.
+
+Table 58 – ZOI in example 2
+
+| Parameter         |                    |                   | Size (bits) | Value (in order)       | Derived meaning                                      |
+|-------------------|--------------------|-------------------|-------------|------------------------|------------------------------------------------------|
+| NZzoi             |                    |                   | 8 (RBAS)    | 1                      | Number of Zones is one                               |
+| Zone <sup>0</sup> | DCzoi <sup>1</sup> |                   | 1           | 1 <sub>b</sub>         | The byte aligned segment follows                     |
+|                   |                    |                   | 1           | 0 <sub>b</sub>         | Image related description class                      |
+|                   |                    |                   | 6           | 001000 <sub>b</sub>    | Resolution levels are specified                      |
+|                   | DCzoi <sup>2</sup> |                   | 1           | 0 <sub>b</sub>         | The byte aligned segment does not follow             |
+|                   |                    |                   | 1           | 0 <sub>b</sub>         | Image related description class                      |
+|                   |                    |                   | 6           | 001100 <sub>b</sub>    | Sub-bands and code-blocks are specified              |
+|                   | Pzoi <sup>3</sup>  | Mzoi <sup>3</sup> | 1           | 0 <sub>b</sub>         | The byte aligned segment does not follow             |
+|                   |                    |                   | 1           | 0 <sub>b</sub>         | The specified zones are influenced by the JPSEC tool |
+|                   |                    |                   | 1           | 0 <sub>b</sub>         | Single item is specified                             |
+|                   |                    |                   | 2           | 10 <sub>b</sub>        | Index mode                                           |
+|                   |                    |                   | 2           | 00 <sub>b</sub>        | Izoi uses 8-bit integer                              |
+|                   |                    |                   | 1           | 0 <sub>b</sub>         | Izoi is described in one dimension                   |
+|                   |                    | Izoi <sup>3</sup> | 8           | 0000 0000 <sub>b</sub> | Resolution level index is 0                          |
+|                   | Pzoi <sup>9</sup>  | Mzoi <sup>8</sup> | 1           | 0 <sub>b</sub>         | The byte aligned segment does not follow             |
+|                   |                    |                   | 1           | 0 <sub>b</sub>         | The specified zones are influenced by the JPSEC tool |
+|                   |                    |                   | 1           | 0 <sub>b</sub>         | Single item is specified                             |
+|                   |                    |                   | 2           | 10 <sub>b</sub>        | Index mode                                           |
+|                   |                    |                   | 2           | 00 <sub>b</sub>        | Izoi uses 8-bit integer                              |
+|                   |                    |                   | 1           | 0 <sub>b</sub>         | Izoi is described in one dimension                   |
+|                   |                    | Izoi <sup>8</sup> | 8           | 0000 0001 <sub>b</sub> | Sub-band 1 is specified                              |
+|                   | Pzoi <sup>10</sup> | Mzoi <sup>9</sup> | 1           | 0 <sub>b</sub>         | The byte aligned segment does not follow             |
+|                   |                    |                   | 1           | 0 <sub>b</sub>         | The specified zones are influenced by the JPSEC tool |
+|                   |                    |                   | 1           | 0 <sub>b</sub>         | Single item is specified                             |
+|                   |                    |                   | 2           | 00 <sub>b</sub>        | Rectangle mode                                       |
+|                   |                    |                   | 2           | 00 <sub>b</sub>        | Izoi uses 8-bit integer                              |
+|                   |                    |                   | 1           | 0 <sub>b</sub>         | Izoi is described in one dimension                   |
+|                   |                    | Izoi <sup>9</sup> | 8           | 0000 0101 <sub>b</sub> | Code-block index for the upper-left corner is 5      |
+|                   |                    |                   | 8           | 0000 1010 <sub>b</sub> | Code-block index for the lower-right corner is 10    |
+
+### 6.1.3 Example 3
+
+This clause shows the example that the data segments from bytes 10 to 100 and from bytes 10000 to 12000 are influenced. In this example, 12 bytes are necessary.
+
+**Table 59 – ZOI in example 3**
+
+| Parameter         |                   |                    | Size (bits) | Value (in order)                              | Derived meaning                                      |
+|-------------------|-------------------|--------------------|-------------|-----------------------------------------------|------------------------------------------------------|
+| NZzoi             |                   |                    | 8 (RBAS)    | 1                                             | Number of Zones is one                               |
+| Zone <sup>0</sup> | DCzoi             |                    | 1           | 0 <sub>b</sub>                                | The byte aligned segment does not follow             |
+|                   |                   |                    | 1           | 1 <sub>b</sub>                                | Non-image related description class                  |
+|                   |                   |                    | 6           | 010000 <sub>b</sub>                           | Byte ranges after the SOD marker are specified       |
+|                   | Pzoi <sup>2</sup> | Mzoi <sup>2</sup>  | 1           | 0 <sub>b</sub>                                | The byte aligned segment does not follow             |
+|                   |                   |                    | 1           | 0 <sub>b</sub>                                | The specified zones are influenced by the JPSEC tool |
+|                   |                   |                    | 1           | 1 <sub>b</sub>                                | Multiple items are specified                         |
+|                   |                   |                    | 2           | 01 <sub>b</sub>                               | Range mode                                           |
+|                   |                   |                    | 2           | 01 <sub>b</sub>                               | Izoi uses 16-bit integer                             |
+|                   |                   |                    | 1           | 0 <sub>b</sub>                                | Izoi is described in one dimension                   |
+|                   |                   |                    | 8           | 0000 0010 <sub>b</sub>                        | Number of data segments is 2                         |
+|                   |                   | Izoi <sup>21</sup> | 16          | 0000 0000 <sub>b</sub> 0000 1010 <sub>b</sub> | Starting byte location is 10th (bytes)               |
+|                   |                   |                    | 16          | 0000 0000 <sub>b</sub> 0110 0100 <sub>b</sub> | Ending byte location is 100th (bytes)                |
+|                   |                   | Izoi <sup>21</sup> | 16          | 0010 0111 <sub>b</sub> 0001 0000 <sub>b</sub> | Starting byte location is 10000th (bytes)            |
+|                   |                   |                    | 16          | 0010 1110 <sub>b</sub> 1110 0000 <sub>b</sub> | Ending byte location is 12000th (bytes)              |
+
+### 6.1.4 Example 4
+
+This clause shows the example that resolution level 0 is influenced and that the byte segments 10 through 100 correspond to the data for resolution level 0. In this example, 10 bytes are necessary.
+
+**Table 60 – ZOI in example 4**
+
+| Parameter         |                    |                   | Size (bits) | Value (in order)                 | Derived meaning                                      |
+|-------------------|--------------------|-------------------|-------------|----------------------------------|------------------------------------------------------|
+| NZzoi             |                    |                   | 8 (RBAS)    | 1                                | Number of Zones is one                               |
+| Zone <sup>0</sup> | DCzoi <sup>1</sup> |                   | 1           | 1 <sub>b</sub>                   | The byte aligned segment follows                     |
+|                   |                    |                   | 1           | 0 <sub>b</sub>                   | Image related description class                      |
+|                   |                    |                   | 6           | 001000 <sub>b</sub>              | Resolution levels are specified in order             |
+|                   | DCzoi <sup>2</sup> |                   | 1           | 0 <sub>b</sub>                   | The byte aligned segment does not follow             |
+|                   |                    |                   | 1           | 1 <sub>b</sub>                   | Non-image related description class                  |
+|                   |                    |                   | 6           | 010000 <sub>b</sub>              | Byte ranges are specified                            |
+|                   | Pzoi <sup>1</sup>  | Mzoi <sup>1</sup> | 1           | 0 <sub>b</sub>                   | The byte aligned segment does not follow             |
+|                   |                    |                   | 1           | 0 <sub>b</sub>                   | The specified zones are influenced by the JPSEC tool |
+|                   |                    |                   | 1           | 0 <sub>b</sub>                   | Single item is specified                             |
+|                   |                    |                   | 2           | 10 <sub>b</sub>                  | Index mode                                           |
+|                   |                    |                   | 2           | 00 <sub>b</sub>                  | Izoi uses 8-bit integer                              |
+|                   |                    |                   | 1           | 0 <sub>b</sub>                   | Izoi is described in one dimension                   |
+|                   |                    | Izoi <sup>1</sup> | 8           | 0000 0000 <sub>b</sub>           | Resolution level is 0                                |
+|                   | Pzoi <sup>2</sup>  | Mzoi <sup>2</sup> | 1           | 0 <sub>b</sub>                   | The byte aligned segment does not follow             |
+|                   |                    |                   | 1           | 0 <sub>b</sub>                   | The specified zones are influenced by the JPSEC tool |
+|                   |                    |                   | 1           | 0 <sub>b</sub>                   | Single items specified                               |
+|                   |                    |                   | 2           | 01 <sub>b</sub>                  | Range mode                                           |
+|                   |                    |                   | 2           | 01 <sub>b</sub>                  | Izoi uses 16-bit integer                             |
+|                   |                    |                   | 1           | 0 <sub>b</sub>                   | Izoi is described in one dimension                   |
+|                   |                    | Izoi <sup>1</sup> | 16          | 0000 0000 0000 1010 <sub>b</sub> | Starting byte location is 10th (bytes)               |
+|                   |                    |                   | 16          | 0000 0000 0110 0100 <sub>b</sub> | Ending byte location is 100th (bytes)                |
+
+### 6.1.5 Example 5
+
+This clause shows the example that resolution levels more than 3 in the tiles whose upper-left tile index is 0 and lower-right tile index is 5, and layers equal to or less than 5 in the tiles whose upper-left tile index is 10 and lower-right tile index is 15 are influenced. In this example, 13 bytes are necessary.
+
+**Table 61 – ZOI in example 5**
+
+| Parameter         |                   |                   | Size (bits) | Value (in order)       | Derived meaning                                                                                                       |  |
+|-------------------|-------------------|-------------------|-------------|------------------------|-----------------------------------------------------------------------------------------------------------------------|--|
+| NZzoi             |                   |                   | 8 (RBAS)    | 2                      | Number of Zones is two                                                                                                |  |
+| Zone <sup>0</sup> | DCzoi             |                   | 1           | 0 <sub>b</sub>         | The byte aligned segment does not follow                                                                              |  |
+|                   |                   |                   | 1           | 0 <sub>b</sub>         | Image related description class                                                                                       |  |
+|                   |                   |                   | 6           | 01 1000 <sub>b</sub>   | Tiles and resolution levels are specified in order                                                                    |  |
+|                   | Pzoi <sup>2</sup> | Mzoi <sup>2</sup> | 1           | 0 <sub>b</sub>         | The byte aligned segment does not follow                                                                              |  |
+|                   |                   |                   | 1           | 0 <sub>b</sub>         | The specified zones are influenced by the JPSEC tool                                                                  |  |
+|                   |                   |                   | 1           | 0 <sub>b</sub>         | Single item is specified                                                                                              |  |
+|                   |                   |                   | 2           | 00 <sub>b</sub>        | Rectangle mode                                                                                                        |  |
+|                   |                   |                   | 2           | 00 <sub>b</sub>        | Izoi uses 8-bit integer                                                                                               |  |
+|                   |                   |                   | 1           | 0 <sub>b</sub>         | Izoi is described in one dimension                                                                                    |  |
+|                   |                   | Izoi <sup>2</sup> | 8           | 0000 0000 <sub>b</sub> | Upper-left tile index is 0                                                                                            |  |
+|                   |                   |                   | 8           | 0000 0101 <sub>b</sub> | Lower-right tile index is 5                                                                                           |  |
+|                   | Pzoi <sup>3</sup> | Mzoi <sup>3</sup> | 1           | 0 <sub>b</sub>         | The byte aligned segment does not follow                                                                              |  |
+|                   |                   |                   | 1           | 1 <sub>b</sub>         | The complement of the specified zones is influenced by the JPSEC tool                                                 |  |
+|                   |                   |                   | 1           | 0 <sub>b</sub>         | Single item is specified                                                                                              |  |
+|                   |                   |                   | 2           | 11 <sub>b</sub>        | Max mode                                                                                                              |  |
+|                   |                   |                   | 2           | 00 <sub>b</sub>        | Izoi uses 8-bit integer                                                                                               |  |
+|                   |                   |                   | 1           | 0 <sub>b</sub>         | Izoi is described in one dimension                                                                                    |  |
+|                   |                   | Izoi <sup>3</sup> | 8           | 0000 0010 <sub>b</sub> | Resolution levels ≤ 2 are specified. (i.e., Resolution levels > 3 are specified with Max mode and complement switch.) |  |
+|                   |                   |                   |             |                        |                                                                                                                       |  |
+| Zone <sup>1</sup> | DCzoi             |                   | 1           | 0 <sub>b</sub>         | The byte aligned segment does not follow                                                                              |  |
+|                   |                   |                   | 1           | 0 <sub>b</sub>         | Image related description class                                                                                       |  |
+|                   |                   |                   | 6           | 010100 <sub>b</sub>    | Tiles and layers are specified in order                                                                               |  |
+|                   | Pzoi <sup>2</sup> | Mzoi <sup>2</sup> | 1           | 0 <sub>b</sub>         | The byte aligned segment does not follow                                                                              |  |
+|                   |                   |                   | 1           | 0 <sub>b</sub>         | The specified zones are influenced by the JPSEC tool                                                                  |  |
+|                   |                   |                   | 1           | 0 <sub>b</sub>         | Single item is specified                                                                                              |  |
+|                   |                   |                   | 2           | 00 <sub>b</sub>        | Rectangle mode                                                                                                        |  |
+|                   |                   |                   | 2           | 00 <sub>b</sub>        | Izoi uses 8-bit integer                                                                                               |  |
+|                   |                   |                   | 1           | 0 <sub>b</sub>         | Izoi is described in one dimension                                                                                    |  |
+|                   |                   | Izoi <sup>2</sup> | 8           | 0000 1010 <sub>b</sub> | Upper-left tile index is 10                                                                                           |  |
+|                   |                   |                   | 8           | 0000 1111 <sub>b</sub> | Lower-right tile index is 15                                                                                          |  |
+|                   | Pzoi <sup>4</sup> | Mzoi <sup>4</sup> | 1           | 0 <sub>b</sub>         | The byte aligned segment does not follow                                                                              |  |
+|                   |                   |                   | 1           | 0 <sub>b</sub>         | The specified zones are influenced by the JPSEC tool                                                                  |  |
+|                   |                   |                   | 1           | 0 <sub>b</sub>         | Single item is specified                                                                                              |  |
+|                   |                   |                   | 2           | 11 <sub>b</sub>        | Max mode                                                                                                              |  |
+|                   |                   |                   | 2           | 00 <sub>b</sub>        | Izoi uses 8-bit integer                                                                                               |  |
+|                   |                   |                   | 1           | 0 <sub>b</sub>         | Izoi is described in one dimension                                                                                    |  |
+|                   |                   | Izoi <sup>4</sup> | 8           | 0000 0101 <sub>b</sub> | layers ≤ 5 are specified with Max mode                                                                                |  |
+|                   |                   |                   |             |                        |                                                                                                                       |  |
+
+### 6.1.6 Example 6
+
+This clause shows the example that the header segment from bytes 10 to 100 is influenced. In this example, 8 bytes are necessary.
+
+Table 62 – ZOI in example 6
+
+| Parameter         |                               |                               | Size (bits) | Value (in order)                 | Derived meaning                                      |
+|-------------------|-------------------------------|-------------------------------|-------------|----------------------------------|------------------------------------------------------|
+| NZ <sub>zoi</sub> |                               |                               | 8 (RBAS)    | 1                                | Number of Zones is one                               |
+| Zone <sup>0</sup> | DC <sub>zoi</sub>             |                               | 1           | 0 <sub>b</sub>                   | The byte aligned segment does not follow             |
+|                   |                               |                               | 1           | 1 <sub>b</sub>                   | Non-image related description class                  |
+|                   |                               |                               | 6           | 001000 <sub>b</sub>              | Byte ranges after the SEC marker are specified       |
+|                   | P <sub>zoi</sub> <sup>3</sup> | M <sub>zoi</sub> <sup>3</sup> | 1           | 0 <sub>b</sub>                   | The byte aligned segment does not follow             |
+|                   |                               |                               | 1           | 0 <sub>b</sub>                   | The specified zones are influenced by the JPSEC tool |
+|                   |                               |                               | 1           | 0 <sub>b</sub>                   | Single item is specified                             |
+|                   |                               |                               | 2           | 01 <sub>b</sub>                  | Range mode                                           |
+|                   |                               |                               | 2           | 01 <sub>b</sub>                  | I <sub>zoi</sub> uses 16-bit integer                 |
+|                   |                               |                               | 1           | 0 <sub>b</sub>                   | I <sub>zoi</sub> is described in one dimension       |
+|                   |                               |                               | 16          | 0000 0000 0000 1010 <sub>b</sub> | Starting byte location is 10th (bytes)               |
+|                   |                               |                               | 16          | 0000 0000 0110 0100 <sub>b</sub> | Ending byte location is 100th (bytes)                |
+|                   | I <sub>zoi</sub> <sup>3</sup> |                               | 16          | 0000 0000 0110 0100 <sub>b</sub> | Ending byte location is 100th (bytes)                |
+
+## 6.2 Key information template examples
+
+### 6.2.1 Example 1
+
+Table 63 shows the example that a single secret key (128 bits) is used to decrypt a codestream, where the secret key is identified using URI and retrieved from the key server based on URI in the decryption stage.
+
+Table 63 – Key information in example 1
+
+| Parameter         |                |  | Size (bits) | Value                              | Derived meaning                                              |
+|-------------------|----------------|--|-------------|------------------------------------|--------------------------------------------------------------|
+| LK <sub>KT</sub>  |                |  | 16          | 128                                | Length of key is 128 bits                                    |
+| KID <sub>KT</sub> |                |  | 8           | 2                                  | URI for secret key is identified                             |
+| G <sub>KT</sub>   | PO             |  | 16          | 000 001 010 011 100 0 <sub>b</sub> | Processing order is tile-resolution-layer-component-precinct |
+|                   | GL             |  | 8           | 0000 1001 <sub>b</sub>             | Unit of protection is the total area identified in ZOI       |
+| V <sub>KT</sub>   | N <sub>v</sub> |  | 16 (RBAS)   | 1                                  | Number of values in the value list V is 1                    |
+|                   | S <sub>v</sub> |  | 8 (RBAS)    | 19                                 | Length of key information is 19 bytes                        |
+|                   | V1             |  | 152         | https://server/file                | Secret key can be retrieved from https://server/file         |
+
+### 6.2.2 Example 2
+
+Table 64 shows the example that an ITU-T X.509 certificate is used to authenticate a codestream, where the ITU-T X.509 certificate is embedded into KI<sub>KT</sub> with encoding method DER.
+
+Table 64 – Key information in example 2
+
+| Parameter         |                |                    | Size (bits) | Value                              | Derived meaning                                              |
+|-------------------|----------------|--------------------|-------------|------------------------------------|--------------------------------------------------------------|
+| LK <sub>KT</sub>  |                |                    | 16          | 1024                               | Length of key is 1024 bits                                   |
+| KID <sub>KT</sub> |                |                    | 8           | 2                                  | ITU-T X.509 certificate is identified                        |
+| G <sub>KT</sub>   | PO             |                    | 16          | 000 001 010 011 100 0 <sub>b</sub> | Processing order is tile-resolution-layer-component-precinct |
+|                   | GL             |                    | 8           | 0000 1001 <sub>b</sub>             | Unit of protection is total area identified in ZOI           |
+| V <sub>KT</sub>   | N <sub>v</sub> |                    | 16 (RBAS)   | 1                                  | Number of values in the value list V is 1                    |
+|                   | S <sub>v</sub> |                    | 8 (RBAS)    | Variable                           | Length of ITU-T X.509 certificate                            |
+|                   | V1             | ER <sub>KT</sub>   | 8           | 1                                  | ITU-T X.509 certificate is encoded with encoding method DER  |
+|                   |                | LCER <sub>KT</sub> | 16          | Variable                           | Length of CER <sub>KT</sub>                                  |
+|                   |                | CER <sub>KT</sub>  | Variable    | Certificate value                  | Certificate with 1024-bit public key is embedded             |
+
+6.2.3 Example 3
+
+Table 65 shows that a single public key is used to authenticate a codestream, where the public key is embedded into KI<sub>KT</sub>.
+
+Table 65 – Key information in example 3
+
+| Parameter         |                | Size (bits) | Value                              | Derived meaning                                              |
+|-------------------|----------------|-------------|------------------------------------|--------------------------------------------------------------|
+| LK <sub>KT</sub>  |                | 16          | 1024                               | Length of key is 1024 bits                                   |
+| KID <sub>KT</sub> |                | 8           | 1                                  | Public key is identified                                     |
+| G <sub>KT</sub>   | PO             | 16          | 000 001 010 011 100 0 <sub>b</sub> | Processing order is tile-resolution-layer-component-precinct |
+|                   | GL             | 8           | 0000 1001 <sub>b</sub>             | Unit of protection is total area identified in ZOI           |
+| V <sub>KT</sub>   | N <sub>v</sub> | 16 (RBAS)   | 1                                  | Number of values in the value list V is 1                    |
+|                   | S <sub>v</sub> | 8 (RBAS)    | 256                                | Length of public key is 256 bytes                            |
+|                   | V1             | 2048        | Public key value                   | Public key is embedded                                       |
+
+6.2.4 Example 4
+
+Table 66 shows that multiple secret keys are used to decrypt a codestream, where different secret keys are used for different layers.
+
+Table 66 – Key information in example 4
+
+| Parameter         |                | Size (bits) | Value                             | Derived meaning                                                     |
+|-------------------|----------------|-------------|-----------------------------------|---------------------------------------------------------------------|
+| LK <sub>KT</sub>  |                | 16          | 128                               | Length of key is 128 bits                                           |
+| KID <sub>KT</sub> |                | 8           | 3                                 | URI for secret key is identified                                    |
+| G <sub>KT</sub>   | PO             | 16          | 000 001 010 011 1000 <sub>b</sub> | Processing order is tile-resolution-layer-component-precinct        |
+|                   | GL             | 8           | 0000 0100 <sub>b</sub>            | Unit of protection is layer                                         |
+| V <sub>KT</sub>   | N <sub>v</sub> | 16 (RBAS)   | 3                                 | Number of values in the value list V is 3                           |
+|                   | S <sub>v</sub> | 8 (RBAS)    | 16                                | Length of each V <sub>n</sub> is 16 bytes                           |
+|                   | V1             | 128         | https://server/1                  | Secret key for the 1st layer can be retrieved from https://server/1 |
+|                   | V2             | 128         | https://server/2                  | Secret key for the 2nd layer can be retrieved from https://server/2 |
+|                   | V3             | 128         | https://server/3                  | Secret key for the 3rd layer can be retrieved from https://server/3 |
+|                   | V4             | 128         | https://server/4                  | Secret key for the 4th layer can be retrieved from https://server/4 |
+
+6.3 JPSEC normative tool examples
+
+The examples in 6.3.1 and 6.3.2 describe how the ZOI and key templates can be used to perform basic security services such as encryption and authentication on a JPEG 2000 coded image.
+
+6.3.1 Example 1
+
+An image is coded with JPEG 2000 and has three resolutions. In this example the first resolution is not encrypted in order to provide preview capability, and the second and third resolutions are encrypted with keys k1 and k2, respectively. The input image in this case is coded in RLCP progression order, and has 1 tile, 3 resolutions, 3 layers, Nc components, and Np precincts (the number of components and precincts is not significant in this specific example). Encryption is performed using AES in CBC mode without padding (using cipher-text stealing), using key k0 to encrypt resolution 1 and using key k2 to encrypt resolution 2, and resolution 0 is left unencrypted.
+
+JPSEC signals how a JPSEC consumer should decrypt the JPSEC codestream. First, the tool template ID for the decryption template is signalled. Two ZOIs are specified for resolution 1 and its corresponding byte range B0-B1, and for resolution 2 and its corresponding byte range B2-B3. The decryption template parameters identify that AES encryption is applied without padding (using cipher-text stealing). The keying information and the fact that different keys are applied to different resolutions are signalled with the key information parameters. Specifically, the key granularity is specified as resolution so each resolution has a different key, where the processing order is signalled as TRLCP. The key information for each resolution is contained in the value list of keys. The encryption is performed on the codestream, encrypting both the packet headers and packet bodies. The encryption granularity is resolution, where the processing is performed in TRLCP ordering which is the same ordering as the original codestream. Since the two resolutions are encrypted separately, two initialization vectors (IVs) are required, and these are contained in the value list.
+
+Note that packet's cipher text results are specified by the processing order and therefore are independent of input codestream's progression order; however, the placement of the encrypted packets in the output codestream follow the ordering of the input codestream packets.
+
+Table 67 – SEC marker segment for example 1
+
+| Parameter        |                    |                       | Size (bits) | Values               | Meaning                                           |  |  |
+|------------------|--------------------|-----------------------|-------------|----------------------|---------------------------------------------------|--|--|
+| SEC              |                    |                       | 16          | 0xFF65               | SEC marker                                        |  |  |
+| L <sub>SEC</sub> |                    |                       | 16 (RBAS)   | 0x82                 | Length of SEC marker segment is 130 bytes         |  |  |
+| Z <sub>SEC</sub> |                    |                       | 8 (RBAS)    | 0                    | Index of this SEC marker segment                  |  |  |
+| P <sub>SEC</sub> | F <sub>PSEC</sub>  |                       | 1           | 0 <sub>b</sub>       | The FBAS structure does not follow                |  |  |
+|                  |                    | F <sub>INSEC</sub>    | 1           | 0 <sub>b</sub>       | INSEC is not used                                 |  |  |
+|                  |                    | F <sub>multiSEC</sub> | 1           | 0 <sub>b</sub>       | One SEC marker segment is used                    |  |  |
+|                  |                    | F <sub>mod</sub>      | 2           | 00 <sub>b</sub>      | Original JPEG 2000 data was modified              |  |  |
+|                  |                    | F <sub>TRLC</sub>     | 1           | 0 <sub>b</sub>       | TRLC tag usage is not defined in P <sub>SEC</sub> |  |  |
+|                  |                    | F <sub>TRLC</sub>     | 3           | 000 <sub>b</sub>     |                                                   |  |  |
+|                  | N <sub>tools</sub> |                       | 8 (RBAS)    | 0000001 <sub>b</sub> | Number of security tool is one                    |  |  |
+|                  | I <sub>max</sub>   |                       | 8 (RBAS)    | 0000000 <sub>b</sub> | Maximum tool instance index is zero               |  |  |
+| t                |                    |                       | 8 (FBAS)    | 0                    | JPSEC normative tool                              |  |  |
+| i                |                    |                       | 8 (RBAS)    | 0                    | Tool instance index                               |  |  |
+| ID <sub>T</sub>  |                    |                       | 8           | 1                    | Decryption template                               |  |  |
+| L <sub>Zoi</sub> |                    |                       | 16 (RBAS)   | 0x17                 | Length of ZOI is 23 bytes                         |  |  |
+| ZOI              |                    |                       | 184         | See Table 68         | Zone of Influence for this tool                   |  |  |
+| L <sub>PID</sub> |                    |                       | 16 (RBAS)   | 0x5e                 | Length of P <sub>ID</sub> is 94 bytes             |  |  |
+| P <sub>ID</sub>  |                    |                       | 752         | See Table 69         | Parameters for this technology                    |  |  |
+
+Table 68 – ZOI example
+
+| Parameter         |                                 |                                | Size (bits) | Value (in order)       | Derived meaning                                      |
+|-------------------|---------------------------------|--------------------------------|-------------|------------------------|------------------------------------------------------|
+| NZ <sub>Zoi</sub> |                                 |                                | 8 (RBAS)    | 2                      | Number of Zones is one                               |
+| Zone <sup>0</sup> | DC <sub>Zoi</sub> <sup>1</sup>  |                                | 1           | 1 <sub>b</sub>         | The byte aligned segment follows                     |
+|                   |                                 |                                | 1           | 0 <sub>b</sub>         | Image related description class                      |
+|                   |                                 |                                | 6           | 001000 <sub>b</sub>    | Resolution is specified                              |
+|                   | DC <sub>Zoi</sub> <sup>2</sup>  |                                | 1           | 0 <sub>b</sub>         | The byte aligned segment does not follow             |
+|                   |                                 |                                | 1           | 1 <sub>b</sub>         | Non-image related description class                  |
+|                   |                                 |                                | 6           | 010000 <sub>b</sub>    | Byte ranges after the SOD marker are specified       |
+|                   | P <sub>Zoi</sub> <sup>0,1</sup> | M <sub>Zoi</sub> <sup>1</sup>  | 1           | 0 <sub>b</sub>         | The byte aligned segment does not follow             |
+|                   |                                 |                                | 1           | 0 <sub>b</sub>         | The specified zones are influenced by the JPSEC tool |
+|                   |                                 |                                | 1           | 0 <sub>b</sub>         | Single item is specified                             |
+|                   |                                 |                                | 2           | 10 <sub>b</sub>        | Index mode                                           |
+|                   |                                 |                                | 2           | 00 <sub>b</sub>        | I <sub>Zoi</sub> uses 8-bit integer                  |
+|                   |                                 |                                | 1           | 0 <sub>b</sub>         | I <sub>Zoi</sub> is described in one dimension       |
+|                   |                                 | I <sub>Zoi</sub>               | 8           | 0000 0001 <sub>b</sub> | Resolution 1 is specified                            |
+|                   | P <sub>Zoi</sub> <sup>0,2</sup> | M <sub>Zoi</sub> <sup>2</sup>  | 1           | 0 <sub>b</sub>         | The byte aligned segment does not follow             |
+|                   |                                 |                                | 1           | 0 <sub>b</sub>         | The specified zones are influenced by the JPSEC tool |
+|                   |                                 |                                | 1           | 0 <sub>b</sub>         | Single item is specified                             |
+|                   |                                 |                                | 2           | 01 <sub>b</sub>        | Range mode                                           |
+|                   |                                 |                                | 2           | 01 <sub>b</sub>        | I <sub>Zoi</sub> uses 16-bit integer                 |
+|                   |                                 |                                | 1           | 0 <sub>b</sub>         | I <sub>Zoi</sub> is described in one dimension       |
+|                   |                                 | I <sub>Zoi</sub> <sup>21</sup> | 16          | 0x31CC                 | Starting byte location is 12748 (bytes). (B0)        |
+|                   |                                 |                                | 16          | 0xA3E8                 | Ending byte location is 41960 (bytes). (B1)          |
+
+Table 68 – ZOI example
+
+| Parameter         |                     | Size (bits)       | Value (in order)    | Derived meaning                                |                                                      |
+|-------------------|---------------------|-------------------|---------------------|------------------------------------------------|------------------------------------------------------|
+| Zone <sup>1</sup> | DCzoi <sup>1</sup>  | 1                 | 1 <sub>b</sub>      | The byte aligned segment follows               |                                                      |
+|                   |                     | 1                 | 0 <sub>b</sub>      | Image related description class                |                                                      |
+|                   |                     | 6                 | 001000 <sub>b</sub> | Resolution is specified                        |                                                      |
+|                   | DCzoi <sup>2</sup>  | 1                 | 0 <sub>b</sub>      | The byte aligned segment does not follow       |                                                      |
+|                   |                     | 1                 | 1 <sub>b</sub>      | Non-image related description class            |                                                      |
+|                   |                     | 6                 | 010000 <sub>b</sub> | Byte ranges after the SOD marker are specified |                                                      |
+|                   | Pzoi <sup>0,1</sup> | Mzoi <sup>1</sup> | 1                   | 0 <sub>b</sub>                                 | The byte aligned segment does not follow             |
+|                   |                     |                   | 1                   | 0 <sub>b</sub>                                 | The specified zones are influenced by the JPSEC tool |
+|                   |                     |                   | 1                   | 0 <sub>b</sub>                                 | Single item is specified                             |
+|                   |                     |                   | 2                   | 10 <sub>b</sub>                                | Index mode                                           |
+|                   |                     |                   | 2                   | 00 <sub>b</sub>                                | Izoi uses 8-bit integer                              |
+|                   |                     |                   | 1                   | 0 <sub>b</sub>                                 | Izoi is described in one dimension                   |
+|                   |                     | Izoi <sup>1</sup> | 8                   | 0000 0010 <sub>b</sub>                         | Resolution 2 is specified                            |
+|                   | Pzoi <sup>0,2</sup> | Mzoi <sup>2</sup> | 1                   | 0 <sub>b</sub>                                 | The byte aligned segment does not follow             |
+|                   |                     |                   | 1                   | 0 <sub>b</sub>                                 | The specified zones are influenced by the JPSEC tool |
+|                   |                     |                   | 1                   | 0 <sub>b2</sub>                                | Single item is specified                             |
+|                   |                     |                   | 2                   | 01 <sub>b</sub>                                | Range mode                                           |
+|                   |                     |                   | 2                   | 10 <sub>b</sub>                                | Izoi uses 32-bit integer                             |
+|                   |                     |                   | 1                   | 0 <sub>b</sub>                                 | Izoi is described in one dimension                   |
+|                   |                     | Izoi <sup>2</sup> | 32                  | 0xA3EE                                         | Starting byte location is 41966 (bytes). (B2)        |
+|                   |                     |                   | 32                  | 0x21101                                        | Ending byte location is 135425 (bytes). (B3)         |
+
+Table 69 – P<sub>ID</sub> example
+
+| Parameter       |                | Size (bits) | Values                             | Meaning                                                      |
+|-----------------|----------------|-------------|------------------------------------|--------------------------------------------------------------|
+| T <sub>ID</sub> |                | 432         | See Table 70                       | Decryption templates                                         |
+| PD              |                | 8 (FBAS)    | 0 <sub>b</sub>                     | The byte aligned segment does not follow                     |
+|                 |                |             | 0 <sub>b</sub>                     | Pixel domain is not used                                     |
+|                 |                |             | 0 <sub>b</sub>                     | Wavelet coefficient domain is not used                       |
+|                 |                |             | 0 <sub>b</sub>                     | Quantized wavelet coefficient domain is not used             |
+|                 |                |             | 1 <sub>b</sub>                     | Codestream domain is used                                    |
+|                 |                |             | 000 <sub>b</sub>                   | Reserved for ITU-T   ISO use                                 |
+| F <sub>PD</sub> |                | 8 (FBAS)    | 0 <sub>b</sub>                     | The FBAS byte does not follow                                |
+|                 |                |             | 1 <sub>b</sub>                     | Only packet body is encrypted                                |
+|                 |                |             | 000000 <sub>b</sub>                | Reserved for ITU-T   ISO use                                 |
+| G               | PO             | 16          | 000 001 010 011 100 0 <sub>b</sub> | Processing order is tile-resolution-layer-component-precinct |
+|                 | GL             | 8           | 0000 0011 <sub>b</sub>             | Unit of protection is resolution level                       |
+| V               | N <sub>v</sub> | 16 (RBAS)   | 2                                  | Number of values in the value list V is 2                    |
+|                 | S <sub>v</sub> | 8 (RBAS)    | 16                                 | Length of each V <sub>n</sub> is 16 bytes                    |
+|                 | V1             | 128         | IV0                                | Initialization vector value for R1                           |
+|                 | V2             | 128         | IV1                                | Initialization vector value for R2                           |
+
+Table 70 – Decryption template example
+
+| Parameter           |                   | Size | Value (in order)    | Derived meaning                 |
+|---------------------|-------------------|------|---------------------|---------------------------------|
+| ME <sub>decry</sub> |                   | 8    | 0                   | Marker emulation has occurred   |
+| CT <sub>decry</sub> |                   | 16   | 0001 <sub>b</sub>   | Block cipher (AES)              |
+| CP <sub>decry</sub> | M <sub>bc</sub>   | 6    | 100000 <sub>b</sub> | CBC mode. Bits are not padded   |
+|                     | P <sub>bc</sub>   | 2    | 00 <sub>b</sub>     | Ciphertext stealing             |
+|                     | SIZ <sub>bc</sub> | 8    | 16                  | Block size (16 bytes, 128 bits) |
+|                     | KT <sub>bc</sub>  | 392  | See Table 71        | Key template                    |
+
+Table 71 – Key template example
+
+| Parameter         |                | Size (bits) | Value                              | Derived meaning                                                             |
+|-------------------|----------------|-------------|------------------------------------|-----------------------------------------------------------------------------|
+| LK <sub>KT</sub>  |                | 16          | 128                                | Length of key is 128 bits                                                   |
+| KID <sub>KT</sub> |                | 8           | 2                                  | URI for secret key                                                          |
+| G <sub>KT</sub>   | PO             | 16          | 0 000 001 010 011 100 <sub>b</sub> | Processing order is tile-resolution-layer-component-precinct                |
+|                   | GL             | 8           | 0000 0011 <sub>b</sub>             | Unit of protection is resolution level                                      |
+| V <sub>KT</sub>   | N <sub>v</sub> | 32 (RBAS)   | 2                                  | Number of values in the value list V is 2                                   |
+|                   | S <sub>v</sub> | 8 (RBAS)    | 19                                 | Length of each V <sub>n</sub> is 19 bytes                                   |
+|                   | V1             | 152         | https://server/key1                | Secret key for resolution level 1 can be retrieved from https://server/key1 |
+|                   | V2             | 152         | https://server/key2                | Secret key for resolution level 2 can be retrieved from https://server/key2 |
+
+6.3.2 Example 2
+
+In this case, authentication is applied to the same JPEG 2000 coded image as above. In this example all three resolutions and three layers per resolution are authenticated, where the authentication of each resolution uses a different key. Since there are three resolutions there are three keys, and since there are three layers per resolution there will be three MAC values per resolution. Thus, there will be a total of nine MAC values for the entire JPSEC image. Specifically,
+
+- Resolution 0 has MAC values M0, M1, M2 (one for each layer) using key0
+- Resolution 1 has MAC values M3, M4, M5 (one for each layer) using key1
+- Resolution 2 has MAC values M6, M7, M8 (one for each layer) using key2
+
+This example illustrates how authentication can be signalled as well as the flexibility provided by the ZOI and granularity tools. As in the prior example, the input image is coded in RLCP progression order, and has 1 tile, 3 resolutions, 3 layers, Nc components, and Np precincts (the number of components and precincts is not important in this specific example). Authentication is performed using HMAC with SHA-1.
+
+JPSEC signals how a JPSEC consumer can verify or authenticate the JPSEC protected content. First, the tool template ID for the authentication template is signalled. Then the ZOI is used to signal that there are three resolutions and the associated byte ranges for each resolution. The authentication template parameters signal that HMAC is applied using SHA-1. The key information template provides information about the keys including that the key granularity is resolution and supplying the information for each of the three keys in the value list for the keys. The processing domain for authentication is specified as the codestream including packet headers. The tool granularity for authentication is specified as the layer, therefore there are 3 MACs for each resolution, for a total of nine MAC values. The value list contains the nine MAC values. The processing order for the above was identified as TRLCP, which is the same as the original codestream order.
+
+Note that the use of processing order in the granularity field ensures that the same MAC values would result independent of the codestream's progression order.
+
+Note that while this example demonstrated the use of MACs, the same approach can be used to signal the use of multiple digital signatures.
+
+Table 72 – The SEC marker segment
+
+| Parameter         |                    |                       | Size (bits) | Value (in order) | Derived meaning                                     |
+|-------------------|--------------------|-----------------------|-------------|------------------|-----------------------------------------------------|
+| SEC               |                    |                       | 16          | 0xFF65           | SEC Marker                                          |
+| LSEC              |                    |                       | 16          | 0x0099           | Length of SEC marker segment                        |
+| ZSEC              |                    |                       | 8 (RBAS)    | 0                | Index of this SEC marker segment                    |
+| P <sub>SEC</sub>  | F <sub>SEC</sub>   |                       | 1           | 0 <sub>b</sub>   | The FBAS structure does not follow                  |
+|                   |                    | F <sub>INSEC</sub>    | 1           | 0 <sub>b</sub>   | INSEC marker segment is not used                    |
+|                   |                    | F <sub>multiSEC</sub> | 1           | 0 <sub>b</sub>   | Only one SEC marker segment in this codestream      |
+|                   |                    | F <sub>mod</sub>      | 1           | 0 <sub>b</sub>   | Original JPEG 2000 data was not modified            |
+|                   |                    | F <sub>TRLCP</sub>    | 1           | 0 <sub>b</sub>   | The TRLCIP tag is not used                          |
+|                   |                    | Padding               | 3           | 000 <sub>b</sub> | The TRLCIP tag is not used                          |
+|                   | N <sub>tools</sub> |                       | 7           | 1                | Only one tool is used in this codestream            |
+|                   | I <sub>max</sub>   |                       | 7           | 0                | The maximum tool instance index is 0                |
+| Tool <sup>0</sup> | t                  |                       | 8 (FBAS)    | 0                | JPSEC Normative tool                                |
+|                   | i                  |                       | 8 (RBAS)    | 0                | Tool instance index                                 |
+|                   | ID <sub>T</sub>    |                       | 8           | 2                | This normative tool uses an authentication template |
+|                   | L <sub>ZOI</sub>   |                       | 16 (RBAS)   | 0x20             | Length of ZOI is 32 bytes                           |
+|                   | ZOI                |                       | 256         | Table 73         | The covered zone of the image                       |
+|                   | L <sub>PID</sub>   |                       | 16 (RBAS)   | 0x6c             | Length of P <sub>ID</sub> is 108 bytes              |
+|                   | P <sub>ID</sub>    |                       | 928         | Table 74         | Parameters for JPSEC tool                           |
+
+Table 73 – ZOI signalling
+
+| Parameter         |                                 |                               | Size (bits) | Value (in order)    | Derived meaning                                      |
+|-------------------|---------------------------------|-------------------------------|-------------|---------------------|------------------------------------------------------|
+| NZ <sub>zoi</sub> |                                 |                               | 8 (RBAS)    | 1                   | Number of Zones is 1                                 |
+| Zone <sup>0</sup> | DC <sub>zoi</sub> <sup>1</sup>  |                               | 1           | 1 <sub>b</sub>      | The byte aligned segment follows                     |
+|                   |                                 |                               | 1           | 0 <sub>b</sub>      | Image related description class                      |
+|                   |                                 |                               | 6           | 001000 <sub>b</sub> | Resolution levels are specified in order             |
+|                   | DC <sub>zoi</sub> <sup>2</sup>  |                               | 1           | 0 <sub>b</sub>      | The byte aligned segment does not follow             |
+|                   |                                 |                               | 1           | 1 <sub>b</sub>      | Non-image related description class                  |
+|                   |                                 |                               | 6           | 010000 <sub>b</sub> | Byte ranges are specified                            |
+|                   | P <sub>zoi</sub> <sup>0,1</sup> | M <sub>zoi</sub> <sup>1</sup> | 1           | 0 <sub>b</sub>      | The byte aligned segment does not follow             |
+|                   |                                 |                               | 1           | 0 <sub>b</sub>      | The specified zones are influenced by the JPSEC tool |
+|                   |                                 |                               | 1           | 0 <sub>b</sub>      | Single item is specified                             |
+|                   |                                 |                               | 2           | 01 <sub>b</sub>     | Range mode                                           |
+|                   |                                 |                               | 2           | 00 <sub>b</sub>     | I <sub>zoi</sub> uses 8-bit integer                  |
+|                   |                                 |                               | 1           | 0 <sub>b</sub>      | I <sub>zoi</sub> is described in one dimension       |
+|                   |                                 | I <sub>zoi</sub> <sup>1</sup> | 8           | 0                   | The beginning of the range is 0                      |
+|                   |                                 |                               | 8           | 2                   | The end of the range is 2                            |
+| Zone <sup>0</sup> | P <sub>zoi</sub> <sup>0,2</sup> | M <sub>zoi</sub> <sup>2</sup> | 1           | 0 <sub>b</sub>      | The byte aligned segment does not follow             |
+|                   |                                 |                               | 1           | 0 <sub>b</sub>      | The specified zones are influenced by the JPSEC tool |
+|                   |                                 |                               | 1           | 1 <sub>b</sub>      | Multiple items specified                             |
+|                   |                                 |                               | 2           | 01 <sub>b</sub>     | Range mode                                           |
+|                   |                                 |                               | 2           | 10 <sub>b</sub>     | I <sub>zoi</sub> uses 32-bit integer                 |
+|                   |                                 |                               | 1           | 0 <sub>b</sub>      | I <sub>zoi</sub> is described in one dimension       |
+|                   |                                 | N <sub>ZOI</sub>              | 8 (RBAS)    | 3                   | Number of I <sub>ZOI</sub> is 3                      |
+|                   |                                 | I <sub>zoi</sub> <sup>1</sup> | 32          | 104                 | Starting byte location is 104 (bytes)                |
+|                   |                                 |                               | 32          | 12762               | Ending byte location is 12762 (bytes)                |
+
+Table 73 – ZOI signalling
+
+| Parameter |                               | Size (bits) | Value (in order) | Derived meaning                         |
+|-----------|-------------------------------|-------------|------------------|-----------------------------------------|
+|           | I <sub>ZOI</sub> <sup>2</sup> | 32          | 12768            | Starting byte location is 12768 (bytes) |
+|           |                               | 32          | 41980            | Ending byte location is 41980 (bytes)   |
+|           | I <sub>ZOI</sub> <sup>3</sup> | 32          | 41986            | Starting byte location is 41986 (bytes) |
+|           |                               | 32          | 135445           | Ending byte location is 135445 (bytes)  |
+
+Table 74 – P<sub>ID</sub> signalling parameters
+
+| Parameter         |                   |                                |                             | Size (bits)    | Value (in order)                    | Derived meaning                                       |                                                       |
+|-------------------|-------------------|--------------------------------|-----------------------------|----------------|-------------------------------------|-------------------------------------------------------|-------------------------------------------------------|
+| T <sub>auth</sub> | M <sub>auth</sub> |                                |                             | 8              | 0                                   | Authentication methods: Hash-based authentication     |                                                       |
+|                   | P <sub>auth</sub> | M <sub>HMAC</sub>              |                             | 8              | 1                                   | HMAC is used for authentication                       |                                                       |
+|                   |                   | H <sub>HMAC</sub>              |                             | 8              | 1                                   | SHA-1 is used for hashing                             |                                                       |
+|                   |                   | K <sub>T</sub> <sub>HMAC</sub> | L <sub>K<sub>KT</sub></sub> |                | 16                                  | 128                                                   | Length of the key in bits                             |
+|                   |                   |                                | KID <sub>KT</sub>           |                | 8                                   | 3                                                     | KI <sub>KT</sub> contains the URI for the private key |
+|                   |                   |                                | G <sub>KT</sub>             | PO             | 16                                  | 0000 0010<br>1001 1100 <sub>b</sub>                   | The order is tile-resolution-layer-component-precinct |
+|                   |                   |                                |                             | GL             | 8                                   | 0000 0011 <sub>b</sub>                                | Key granularity is resolution                         |
+|                   |                   |                                | V <sub>KT</sub>             | N <sub>v</sub> | 16 (RBAS)                           | 3                                                     | There are 3 keys in the list                          |
+|                   |                   |                                |                             | S <sub>v</sub> | 8 (RBAS)                            | 8                                                     | Size of each key is 8 bytes                           |
+|                   |                   |                                |                             | VL             | 64                                  | Key0                                                  | The first key is <i>key0</i> , for resolution 0       |
+|                   |                   |                                |                             |                | 64                                  | Key1                                                  | The second key is <i>key1</i> , for resolution 1      |
+|                   |                   |                                |                             |                | 64                                  | Key2                                                  | The third key is <i>key2</i> , for resolution 2       |
+|                   |                   | SIZ <sub>HMAC</sub>            |                             |                | 16                                  | 20                                                    | Size of MAC is 20                                     |
+| PD                |                   |                                |                             | 8 (FBAS)       | 0 <sub>b</sub>                      | The byte aligned segment does not follow              |                                                       |
+|                   |                   |                                |                             |                | 0 <sub>b</sub>                      | Pixel domain is not used                              |                                                       |
+|                   |                   |                                |                             |                | 0 <sub>b</sub>                      | Wavelet coefficient domain is not used                |                                                       |
+|                   |                   |                                |                             |                | 0 <sub>b</sub>                      | Quantized wavelet coefficient domain is not used      |                                                       |
+|                   |                   |                                |                             |                | 1 <sub>b</sub>                      | Codestream domain is used                             |                                                       |
+|                   |                   |                                |                             |                | 000 <sub>b</sub>                    | Reserved for ITU-T   ISO use                          |                                                       |
+| F <sub>PD</sub>   |                   |                                |                             | 8 (FBAS)       | 0 <sub>b</sub>                      | The FBAS byte does not follow                         |                                                       |
+|                   |                   |                                |                             |                | 0 <sub>b</sub>                      | Both packet header and body are encrypted             |                                                       |
+|                   |                   |                                |                             |                | 0000 00 <sub>b</sub>                | Reserved for ITU-T   ISO use                          |                                                       |
+| G                 |                   | PO                             |                             | 16             | 0000 0101<br>0011 1000 <sub>b</sub> | The order is tile-resolution-layer-component-precinct |                                                       |
+|                   |                   | GL                             |                             | 8              | 0000 0100 <sub>b</sub>              | Tool granularity is layer                             |                                                       |
+| V                 |                   | N <sub>v</sub>                 |                             | 32 (RBAS)      | 9                                   | There are 9 MACs (3 MACs per resolution)              |                                                       |
+|                   |                   | S <sub>v</sub>                 |                             | 8 (RBAS)       | 20                                  | Size of each MAC is 20 bytes                          |                                                       |
+|                   |                   | VL                             |                             | 160            | M0                                  | The first MAC is <i>M0</i>                            |                                                       |
+|                   |                   |                                |                             | 160            | M1                                  | The second MAC is <i>M1</i>                           |                                                       |
+|                   |                   |                                |                             | 160            | M2                                  | The third MAC is <i>M2</i>                            |                                                       |
+|                   |                   |                                |                             | 160            | M3                                  | The fourth MAC is <i>M3</i>                           |                                                       |
+|                   |                   |                                |                             | 160            | M4                                  | The fifth MAC is <i>M4</i>                            |                                                       |
+|                   |                   |                                |                             | 160            | M5                                  | The sixth MAC is <i>M5</i>                            |                                                       |
+|                   |                   |                                |                             | 160            | M6                                  | The seventh MAC is <i>M6</i>                          |                                                       |
+|                   |                   |                                |                             | 160            | M7                                  | The eighth MAC is <i>M7</i>                           |                                                       |
+|                   |                   |                                |                             | 160            | M8                                  | The ninth MAC is <i>M8</i>                            |                                                       |
+
+## 6.4 Distortion field examples
+
+6.4.1 and 6.4.2 provide a few simple examples on the use of the distortion field.
+
+### 6.4.1 Example 1
+
+This example builds on the ZOI example 3 in 6.1.3 to show how distortion values can be associated with the two data segments signalled by the ZOI in that example. As discussed earlier, example 3 in 6.1.3 signalled two data segments: (1) bytes 10 to 100 and (2) bytes 10000 to 12000. To associate distortion fields to these two data segments requires two steps. First, the distortion field is signalled in DCzoi. Second, the distortion values are signalled using Pzoi<sup>2</sup>. Therefore, the only changes to the ZOI example 3 in 6.1.3 are to set the distortion field bit in DCzoi, and to add Pzoi<sup>2</sup> (the final 9 lines in Table 75).
+
+**Table 75 – Associating distortion field to two data segments  
+(extension of ZOI example 3 in 6.1.3)**
+
+| Parameter         |                   |                     | Size (bits) | Value (in order)                    | Derived meaning                                                                               |
+|-------------------|-------------------|---------------------|-------------|-------------------------------------|-----------------------------------------------------------------------------------------------|
+| NZzoi             |                   |                     | 8 (RBAS)    | 1                                   | Number of Zones is one                                                                        |
+| Zone <sup>0</sup> | DCzoi             |                     | 1           | 0 <sub>b</sub>                      | The byte aligned segment does not follow                                                      |
+|                   |                   |                     | 1           | 1 <sub>b</sub>                      | Non-image related description class                                                           |
+|                   |                   |                     | 6           | 010001 <sub>b</sub>                 | Byte ranges after the SOD marker are specified and associated distortion fields are specified |
+|                   | Pzoi <sup>2</sup> | Mzoi <sup>2</sup>   | 1           | 0 <sub>b</sub>                      | The byte aligned segment does not follow                                                      |
+|                   |                   |                     | 1           | 0 <sub>b</sub>                      | The specified zones are influenced by the JPSEC tool                                          |
+|                   |                   |                     | 1           | 1 <sub>b</sub>                      | Multiple items are specified                                                                  |
+|                   |                   |                     | 2           | 01 <sub>b</sub>                     | Range mode                                                                                    |
+|                   |                   |                     | 2           | 01 <sub>b</sub>                     | Izoi uses 16-bit integer                                                                      |
+|                   |                   |                     | 1           | 0 <sub>b</sub>                      | Izoi is described in one dimension                                                            |
+|                   |                   | Nzoi <sup>2</sup>   | 8 (RBAS)    | 2                                   | Number of data segments is 2                                                                  |
+|                   |                   | Izoi <sup>2,1</sup> | 16          | 0000 0000<br>0000 1010 <sub>b</sub> | Starting byte location is 10th (bytes)                                                        |
+|                   |                   |                     | 16          | 0000 0000<br>0110 0100 <sub>b</sub> | Ending byte location is 100th (bytes)                                                         |
+| Zone <sup>0</sup> | Pzoi <sup>2</sup> | Izoi <sup>2,2</sup> | 16          | 0010 0111<br>0001 0000 <sub>b</sub> | Starting byte location is 10000th (bytes)                                                     |
+|                   |                   |                     | 16          | 0010 1110<br>1110 0000 <sub>b</sub> | Ending byte location is 12000th (bytes)                                                       |
+|                   | Pzoi <sup>6</sup> | Mzoi <sup>6</sup>   | 1           | 0 <sub>b</sub>                      | The byte aligned segment does not follow                                                      |
+|                   |                   |                     | 1           | 0 <sub>b</sub>                      | The specified zones are influenced by the JPSEC tool                                          |
+|                   |                   |                     | 1           | 1 <sub>b</sub>                      | Multiple items are specified                                                                  |
+|                   |                   |                     | 2           | 10 <sub>b</sub>                     | Index mode                                                                                    |
+|                   |                   |                     | 2           | 00 <sub>b</sub>                     | Izoi uses 8 bits to represent each distortion value                                           |
+|                   |                   |                     | 1           | 0 <sub>b</sub>                      | Izoi is described in one dimension                                                            |
+|                   |                   | Nzoi <sup>6</sup>   | 8 (RBAS)    | 2                                   | Number of data segments is 2                                                                  |
+|                   |                   | Izoi <sup>6,1</sup> | 8           | D1 value                            | Distortion value for the first segment                                                        |
+|                   |                   | Izoi <sup>6,2</sup> | 8           | D2 value                            | Distortion value for the second segment                                                       |
+
+### 6.4.2 Example 2
+
+This example describes how distortion values can be associated with JPEG 2000 packets. The DCzoi specifies a range of 4 packets and the distortion field is also signalled. Pzoi<sup>1</sup> gives the range of packets and Pzoi<sup>2</sup> describes the distortion associated with each of these packets. Notice that since Pzoi<sup>1</sup> specifies a range of length 4, and Pzoi<sup>2</sup> specifies 4 values, each item in the range is associated with one value, e.g., each packet is associated with one distortion.
+
+Table 76 – Signalling a range of packets and associating distortions for each packet
+
+| Parameter         |                   | Size (bits)         | Value (in order)    | Derived meaning                                                      |
+|-------------------|-------------------|---------------------|---------------------|----------------------------------------------------------------------|
+| NZzoi             |                   | 8 (RBAS)            | 1                   | Number of Zones is one                                               |
+| Zone <sup>0</sup> | DCzoi             | 1                   | 0 <sub>b</sub>      | The byte aligned segment does not follow                             |
+|                   |                   | 1                   | 1 <sub>b</sub>      | Non-image related description class                                  |
+|                   |                   | 6                   | 100001 <sub>b</sub> | Packets are specified and associated distortion fields are specified |
+|                   | Pzoi <sup>1</sup> | Mzoi <sup>1</sup>   | 1                   | The byte aligned segment does not follow                             |
+|                   |                   |                     | 1                   | The specified zones are influenced by the JPSEC tool                 |
+|                   |                   |                     | 1                   | Single item is specified                                             |
+|                   |                   |                     | 2                   | Range mode                                                           |
+|                   |                   |                     | 2                   | Izoi uses 8-bit integer                                              |
+|                   |                   |                     | 1                   | Izoi is described in one dimension                                   |
+|                   |                   | Nzoi <sup>1</sup>   | 8 (RBAS)            | 1                                                                    |
+|                   |                   | Izoi <sup>11</sup>  | 8                   | Starting packet is number 0                                          |
+|                   |                   |                     | 8                   | Ending packet is number 3                                            |
+|                   | Pzoi <sup>6</sup> | Mzoi <sup>6</sup>   | 1                   | The byte aligned segment does not follow                             |
+|                   |                   |                     | 1                   | The specified zones are influenced by the JPSEC tool                 |
+|                   |                   |                     | 1                   | Multiple items are specified                                         |
+|                   |                   |                     | 2                   | Index mode                                                           |
+|                   |                   |                     | 2                   | Izoi uses 8 bits to represent each distortion value                  |
+|                   |                   |                     | 1                   | Izoi is described in one dimension                                   |
+|                   |                   | Nzoi <sup>6</sup>   | 8 (RBAS)            | 4                                                                    |
+|                   |                   | Izoi <sup>6,1</sup> | 8                   | Distortion value for the first packet                                |
+|                   |                   | Izoi <sup>6,2</sup> | 8                   | Distortion value for the second packet                               |
+|                   |                   | Izoi <sup>6,3</sup> | 8                   | Distortion value for the third packet                                |
+|                   |                   | Izoi <sup>6,4</sup> | 8                   | Distortion value for the fourth packet                               |
+
+## Annex A
+
+## Guidelines and use cases
+
+(This annex forms an integral part of this Recommendation | International Standard.)
+
+## A.1 A class of JPSEC applications
+
+### A.1.1 Introduction
+
+This clause gives a conceptual description of how a class of JPSEC applications can be implemented. This class of application exemplifies scenarios of secure JPEG 2000 image distribution. The following clauses provide an overview of a conceptual JPSEC application including JPSEC entities and information that are communicated between them. This description is conceptual and neither intends to define a concrete implementation nor specify requirements for an implementation; specific applications might or might not include entities identified in the following description.
+
+### A.1.2 Overview of a secure JPEG 2000 image distribution
+
+Figure A.1 shows an overview of the class of JPSEC applications of secure JPEG 2000 image distribution. In these applications, the JPSEC application can be required to provide various security services for JPEG 2000, for example, confidentiality of image exchange, authentication of image source and content.
+
+![Figure A.1: Overview of a secure JPEG 2000 image distribution application. The diagram shows a flow from an input image and security property to a JPSEC creator, which generates a JPSEC bitstream. This bitstream is distributed through a JPSEC node to a JPSEC decoder, which produces the final image/security output. A cryptographic data manager handles cryptographic data throughout the process.](06291c5328a7a4335d41a48850a3a207_img.jpg)
+
+```
+
+graph LR
+    SP1[Security property] --> CDM[Cryptographic data manager]
+    CDM --> JPSEC_CREATOR[JPSEC creator]
+    CDM --> JPSEC_DECODER[JPSEC decoder]
+    CDM --> JPSEC_NODE[JPSEC node]
+    SP2[Security property] --> JPSEC_CREATOR
+    IMG_IN[Image] --> JPSEC_CREATOR
+    JPSEC_CREATOR --> JPSEC_BITSTREAM[JPSEC bitstream]
+    JPSEC_BITSTREAM --> JPSEC_NODE
+    JPSEC_NODE --> JPSEC_DECODER
+    JPSEC_DECODER --> IMG_OUT[Image/security output]
+  
+```
+
+The diagram illustrates the workflow of a secure JPEG 2000 image distribution application. It starts with an input image and a security property being fed into a JPSEC creator. The JPSEC creator generates a JPSEC bitstream, which is then distributed through a JPSEC node to a JPSEC decoder. The JPSEC decoder produces the final image/security output. A cryptographic data manager is involved in the process, receiving security properties and distributing cryptographic data to the JPSEC creator, JPSEC node, and JPSEC decoder. The JPSEC bitstream is shown as a small image with a red and blue pattern, and the final output is a larger image with the same pattern.
+
+Figure A.1: Overview of a secure JPEG 2000 image distribution application. The diagram shows a flow from an input image and security property to a JPSEC creator, which generates a JPSEC bitstream. This bitstream is distributed through a JPSEC node to a JPSEC decoder, which produces the final image/security output. A cryptographic data manager handles cryptographic data throughout the process.
+
+**Figure A.1 – Overview of a secure JPEG 2000 image distribution application**
+
+In the secure JPEG 2000 image distribution application, one can identify the following steps:
+
+- Step 1: A JPSEC codestream is created by a JPSEC creator.
+- Step 2: The JPSEC codestream is distributed through some JPSEC node or nodes.
+- Step 3: The JPSEC codestream is received and rendered by a JPSEC consumer.
+
+#### Step 1: JPSEC codestream creation
+
+The creator is in charge of creating the secure JPEG 2000 codestream. This codestream can be created from bitmap data or from JPEG 2000 compressed data. A JPSEC creator applies various security techniques, such as encryption, signature generation, and ICV (Integrity Check Value) generation to a given image data.
+
+To secure the image data, the creator defines which Security Parameter Property is associated to the image. A "Security Parameter Property" includes the following attributes:
+
+- Zone of Influence (coverage area of each protection method);
+- Processing Domain (domain to be processed by each protection method);
+- Granularity (unit of each protection method);
+- JPSEC tool identification (applied cryptographic algorithm and related parameters).
+
+*Step 2: JPSEC codestream delivery*
+
+A JPSEC codestream can be transferred to a JPSEC consumer either directly via a network or media (such as a CD-ROM). It can also be transferred through a JPSEC node which can apply various types of additional processing, such as a transcoding, to the JPSEC codestream.
+
+When required by the JPSEC security tool methods in the Security Property Parameter of the JPSEC codestream (e.g., for encryption, or for authentication), the JPSEC creator shall distribute to the JPSEC consumer the corresponding cryptographic data through an independent ('secret') channel. This data, such as key or digital signature, can be managed either manually or automatically by a cryptographic data manager.
+
+*Step 3: JPSEC codestream consumption rendering*
+
+A JPSEC codestream is subject to a JPSEC consumer process according to the applied Security Parameter property: this implies applying the appropriate security techniques, such as decryption, authentication and integrity check. Further, for each JPSEC tool security method a JPSEC creator and JPSEC consumer can use various types of cryptographic data.
+
+As an output of the JPSEC consumer, a decrypted image data and/or security output, such as a verification result, is produced.
+
+The following clauses provide further detail of a conceptual JPSEC entity according to a JPSEC service. Figure A.2 shows the legend description to be used.
+
+![Figure A.2 – Legend description. The legend defines symbols for JPSEC process (blue hatched box), JPEG 2000 process (orange hatched box), Security technique (green hatched box), Data flow for JPSEC (solid blue arrow), Data flow for JPEG 2000 (dashed red arrow), Parameterized function (double-line border box), and Optional function (dashed border box).](f23879f003c58b57f690e2dc6c95816a_img.jpg)
+
+JPSEC process      Data flow for JPSEC      Parameterized function  
+ JPEG 2000 process      Data flow for JPEG 2000      Optional function  
+ Security technique
+
+T.807(23)\_FA.2
+
+Figure A.2 – Legend description. The legend defines symbols for JPSEC process (blue hatched box), JPEG 2000 process (orange hatched box), Security technique (green hatched box), Data flow for JPSEC (solid blue arrow), Data flow for JPEG 2000 (dashed red arrow), Parameterized function (double-line border box), and Optional function (dashed border box).
+
+**Figure A.2 – Legend description**
+
+- **JPSEC process:** A process that uses tools defined in this Recommendation | International Standard.
+- **JPEG 2000 process:** A process defined in Rec. ITU-T T.800 | ISO/IEC 15444-1 (the JPEG 2000 Core coding system).
+- **Security technique:** A well-known security technique either defined in this Recommendation | International Standard or in some other standard or document.
+- **Data flow for JPSEC:** A data flow that communicates information defined in this Recommendation | International Standard. A dashed line indicates optional.
+- **Data flow for JPEG 2000:** A data flow defined in Rec. ITU-T T.800 | ISO/IEC 15444-1 (the JPEG 2000 Core coding system).
+- **Parameterized function:** A function which has several alternate functions that can be selected by an application.
+- **Optional function:** A function which can be optionally applied in a JPSEC application.
+
+## A.1.3 Encryption end description procedure
+
+![Figure A.3 – Encryption procedure diagram](fef7e3f08b408e4ab937a75f5c8b6bfc_img.jpg)
+
+The diagram illustrates the encryption procedure. It shows a flow from left to right. On the left, inputs are 'Keys' and 'Security property' (blue arrows) entering the 'JPSEC encryption procedure' block. This block contains a dashed box for 'Marker emulation prevention' and a green box for 'Cipher'. Below this is a large blue hatched box for 'ZOI selection', 'Domain selection', and 'Granularity composition'. This box receives a 'Security property' output from the JPSEC block and has a 'Security property' output to the right. Below the blue box is an orange hatched box for the 'JPEG 2000 encoder procedure', containing 'Transformation', 'Quantization', 'Arithmetic encode', and 'Packet compose' blocks. A 'Bitmap' (dashed red arrow) enters the 'Transformation' block. A 'Bitstream/codestream' (dashed red arrow) enters the 'Packet compose' block. Blue double-headed arrows connect the 'ZOI selection' box to each of the four encoder blocks. The 'Packet compose' block outputs to a vertical blue hatched box labeled 'SEC / INSEC'. This box outputs 'Encrypted JPEG 2000 codestream' and 'Encrypted stream' to the right. A 'T.807(23)\_FA.3' label is at the bottom right.
+
+Figure A.3 – Encryption procedure diagram
+
+Figure A.3 – Encryption procedure
+
+Figure A.3 shows the overview of an example encryption procedure for a JPSEC creator. This procedure includes the following processes:
+
+- extract data according to the specified Processing Domain;
+- select a portion of extracted data according to the specified Zone of Influence (i.e., a partial encryption);
+- encrypt the selected data using the specified security technique. Further, it is possible to encrypt data in a unit based on the Granularity. In this case, different keys can be used for different units;
+- replace the plaintext data with encrypted data;
+- (optionally) apply a marker emulation prevention mechanism;
+- compose the Security Parameter Property in the SEC and/or INSEC marker segment.
+
+Note that in general the JPSEC encryption procedure generates JPSEC codestream that is not backward compatible with the JPEG 2000 Core coding system. The image data is intended to be passed on to a JPEG 2000 Core coding system compliant decoder after appropriate decryption. It is possible to apply a marker emulation prevention mechanism to avoid marker segment emulation within the encrypted codestream.
+
+![Figure A.4 – Decryption procedure diagram](83c2ebae8819e9cdca7eb157a13ee26a_img.jpg)
+
+The diagram illustrates the decryption procedure. It shows a flow from left to right. On the left, inputs are 'Keys' and 'Security property' (blue arrows) entering the 'JPSEC encryption procedure' block. This block contains a dashed box for 'Marker emulation prevention' and a green box for 'Cipher'. Below this is a large blue hatched box for 'ZOI selection', 'Domain selection', and 'Granularity composition'. This box receives a 'Security property' output from the JPSEC block and has a 'Security property' output to the right. Below the blue box is an orange hatched box for the 'JPEG 2000 decoder procedure', containing 'Packet analyse', 'Packet decompose', 'Arithmetic decode', 'Inverse quantization', and 'Inverse transformation' blocks. An 'Encrypted JPEG 2000 codestream' (blue arrow) enters the 'Packet analyse' block. An 'Encrypted stream' (blue arrow) enters the 'Packet analyse' block. Blue double-headed arrows connect the 'ZOI selection' box to each of the five decoder blocks. The 'Inverse transformation' block outputs to a vertical blue hatched box labeled 'SEC / INSEC'. This box outputs 'Decrypted image' and 'Decrypted bitstream/codestream' to the right. A 'T.807(23)\_FA.4' label is at the bottom right.
+
+Figure A.4 – Decryption procedure diagram
+
+Figure A.4 – Decryption procedure
+
+Figure A.4 shows the overview of an example decryption procedure for a JPSEC consumer. This procedure includes the following processes:
+
+- parse the Security Parameter Property in the SEC and/or INSEC marker segment;
+- extract data according to the signalled Processing Domain;
+- select a portion of extracted data according to keys to be retained (i.e., a partial decryption);
+- decrypt the selected data using a signalled security technique. Further, it is possible to decrypt data in a unit based on the Granularity;
+- replace encrypted data with decrypted data;
+- apply a marker emulation prevention mechanism, if applied at the encryption process.
+
+#### A.1.4 Signature generation and authentication procedure
+
+![Figure A.5: Signature generation procedure diagram. The diagram illustrates the flow of data and control signals for signature generation. Inputs on the left include 'Keys' and 'Security property' (solid blue arrows) and 'Bitmap' and 'Bitstream/codestream' (dashed red arrows). The 'JPSEC signature generation procedure' block at the top contains three sub-processes: 'Transcodable signature generation procedure', 'Fragile signature generation procedure', and 'Semi-fragile signature generation procedure (Lossy/lossless)', all leading to a 'Signature generation' block. Below this is the 'ZOI selection Domain selection Granularity composition' block. The 'JPEG 2000 encoder procedure' block at the bottom contains 'Transformation', 'Quantization', 'Arithmetic encode', and 'Packet compose' sub-processes. Data flows from the encoder to the ZOI selection block and then to the signature generation block. A 'SEC/INSEC' block on the right receives 'Security property' and outputs 'Signed codestream' and 'Signed stream'. A dashed red arrow indicates a feedback path from the encoder to the signature generation block. The identifier 'T.807(23)_FA.5' is at the bottom right.](dfafe39c233a62ec8ebd71e42992c14d_img.jpg)
+
+Figure A.5: Signature generation procedure diagram. The diagram illustrates the flow of data and control signals for signature generation. Inputs on the left include 'Keys' and 'Security property' (solid blue arrows) and 'Bitmap' and 'Bitstream/codestream' (dashed red arrows). The 'JPSEC signature generation procedure' block at the top contains three sub-processes: 'Transcodable signature generation procedure', 'Fragile signature generation procedure', and 'Semi-fragile signature generation procedure (Lossy/lossless)', all leading to a 'Signature generation' block. Below this is the 'ZOI selection Domain selection Granularity composition' block. The 'JPEG 2000 encoder procedure' block at the bottom contains 'Transformation', 'Quantization', 'Arithmetic encode', and 'Packet compose' sub-processes. Data flows from the encoder to the ZOI selection block and then to the signature generation block. A 'SEC/INSEC' block on the right receives 'Security property' and outputs 'Signed codestream' and 'Signed stream'. A dashed red arrow indicates a feedback path from the encoder to the signature generation block. The identifier 'T.807(23)\_FA.5' is at the bottom right.
+
+Figure A.5 – Signature generation procedure
+
+Figure A.5 shows the overview of an example signature generation procedure for a JPSEC creator. This procedure includes the following processes:
+
+- extract data according to the specified Processing Domain;
+- select a portion of extracted data according to the specified Zone of Influence (i.e., partial signature);
+- calculate digital signatures corresponding to selected data using the specified security technique. Further, it is possible to generate digital signatures in a unit based on the Granularity;
+- compose the Security Parameter Property, including the calculated digital signatures, in the SEC and/or INSEC marker segment.
+
+Note that in JPSEC, three modes of authentication are defined: "fragile mode", "semi-fragile mode (lossy/lossless)", and "transcodable mode". A "fragile mode" authentication can detect any one-bit modification for a codestream, where a "semi-fragile" mode authentication can detect any intentional detection but survive incidental distortion up to a predetermined extent. Further, a "transcoding mode" authentication can verify the source part of the codestream.
+
+![Figure A.6 – Authentication procedure diagram](29fbbed4c4aff19e9ac5bf98e0c9b24d_img.jpg)
+
+The diagram illustrates the authentication procedure for a JPSEC consumer. It shows the flow from input streams to a verification result. The process is divided into three main sections: JPSEC signature generation procedure, ZOI selection, and JPEG 2000 decoder procedure.
+
+- Inputs:** Keys, Signed bitstream, and Signed stream.
+- JPSEC signature generation procedure:** This section includes three sub-procedures: Transcodable signature generation procedure, Fragile signature generation procedure, and Semi-fragile signature generation procedure (Lossy/lossless). These are all part of the JPSEC signature generation procedure.
+- ZOI selection:** This section includes ZOI selection, Domain selection, and Granularity composition. It receives input from the JPSEC signature generation procedure and the Signed stream.
+- JPEG 2000 decoder procedure:** This section includes Packet analyse, Packet decompose, Arithmetic decode, Inverse quantization, and Inverse transformation. It receives input from the Signed stream and the ZOI selection section.
+- Output:** Verification result.
+
+The diagram also shows a vertical bar labeled SEC/INSEC on the left side, which is connected to the Signed stream and the JPSEC signature generation procedure.
+
+Figure A.6 – Authentication procedure diagram
+
+T.807(23)\_FA.6
+
+Figure A.6 – Authentication procedure
+
+Figure A.6 shows the overview of an example authentication procedure for a JPSEC consumer. This procedure includes the following processes:
+
+- extract data in a signalled Processing Domain;
+- select a portion of extracted data according to the signalled Zone of Influence;
+- verify the selected data using the signalled security technique. Further, it is possible to verify the selected data in a unit based on the Granularity.
+
+#### A.1.5 Integrity check value (ICV) generation and integrity check procedure
+
+![Figure A.7 – ICV generation procedure diagram](ada2aa7cce9cff9cf116d9ae2b8b7c27_img.jpg)
+
+The diagram illustrates the ICV generation procedure for a JPSEC creator. It shows the flow from input streams to the final ICV appended codestream and stream.
+
+- Inputs:** Keys, Security property, Bitmap, and Bitstream/codestream.
+- JPSEC ICV generation procedure:** This section includes Marker emulation prevention and Cipher. It receives input from Keys and Security property.
+- ZOI selection:** This section includes ZOI selection, Domain selection, and Granularity composition. It receives input from the JPSEC ICV generation procedure and the Bitmap.
+- JPEG 2000 encoder procedure:** This section includes Transformation, Quantization, Arithmetic encode, and Packet compose. It receives input from the Bitstream/codestream and the ZOI selection section.
+- Output:** ICV appended codestream and ICV appended stream.
+
+The diagram also shows a vertical bar labeled SEC/INSEC on the right side, which is connected to the JPSEC ICV generation procedure and the JPEG 2000 encoder procedure.
+
+Figure A.7 – ICV generation procedure diagram
+
+T.807(23)\_FA.7
+
+Figure A.7 – ICV generation procedure
+
+Figure A.7 shows the overview of an example ICV generation procedure for a JPSEC creator. This procedure includes the following processes:
+
+- extract data in a specified Processing Domain;
+- select a portion of extracted data according to the specified Zone of Influence;
+
+- calculate ICVs corresponding to selected data using the specified security technique. Further, it is possible to generate ICVs in a unit based on the Granularity;
+- compose the Security Parameter Property, including the calculated ICVs, in a SEC and/or INSEC marker segment.
+
+![Figure A.8 – Integrity check procedure diagram](e2b7490a3455c66c85db12872c78fcc3_img.jpg)
+
+The diagram illustrates the integrity check procedure for a JPSEC consumer. It shows the flow of data and control signals between several components:
+
+- Inputs:** 'Keys' and 'ICV appended bitstream' enter from the left. 'ICV appended stream' enters from the bottom left.
+- SEC/INSEC Marker:** A vertical blue bar labeled 'SEC / INSEC' receives inputs from the 'ICV appended bitstream' and 'ICV appended stream'. It outputs a 'Security property' signal.
+- JPSEC integrity check procedure:** A large white box at the top receives 'Keys' and 'Security property' signals. It contains a green hatched box labeled 'Check'.
+- ZOI selection, Domain selection, Granularity composition:** A blue hatched box in the middle receives 'Security property' and 'Check' signals. It outputs signals to the 'JPSEC integrity check procedure' and the 'JPEG 2000 decoder procedure'.
+- JPEG 2000 decoder procedure:** An orange hatched box at the bottom contains a sequence of steps: 'Packet analyse', 'Packet decompose', 'Arithmetic decode', 'Inverse quantization', and 'Inverse transformation'. These steps are connected by dashed red arrows. It receives signals from the 'ZOI selection' box and outputs to the 'JPSEC integrity check procedure'.
+- Output:** The 'Check' box outputs a 'Check result' signal to the right.
+
+T.807(23)\_FA.8
+
+Figure A.8 – Integrity check procedure diagram
+
+**Figure A.8 – Integrity check procedure**
+
+Figure A.8 shows the overview of an example integrity check procedure for a JPSEC consumer. This procedure includes the following processes:
+
+- extract data according to the signalled Processing Domain;
+- select a portion of extracted data according to a signalled Zone of Influence;
+- verify selected data using a signalled security technique. Further, it is possible to verify the selected data in a unit based on the Granularity.
+
+## Annex B
+
+## Interoperability
+
+(This annex forms an integral part of this Recommendation | International Standard.)
+
+**B.1 Rec. ITU-T T.800 | ISO/IEC 15444-1 – Core coding system**
+
+A number of protection methods can be applied to a JPEG 2000 codestream to create JPSEC codestreams that are still strictly compliant with the JPEG 2000 Core coding system. The term "Core coding system compliance" refers to JPSEC codestreams that have a strictly defined behaviour for JPEG 2000 Core coding system decoders including those that are not aware of JPSEC.
+
+A JPEG 2000 Core coding system decoder will skip marker segments that it does not recognize. A JPSEC tool such as the JPSEC normative tool for authentication inserts message authentication code values that are computed from the JPEG 2000 data into the SEC marker segment along with the parameters that describe the particular authentication methods that can be used by a JPSEC consumer. These parameters and values tell a JPSEC consumer how to verify that the received JPSEC codestream is authentic. Notice that the JPSEC authentication tool does not manipulate the JPEG 2000 data. Thus, a JPEG 2000 Core coding system decoder that receives this JPSEC codestream will begin decoding the JPSEC stream, it will then skip the SEC marker segment, and continue to decode the JPSEC stream as if it were a JPEG 2000 Core coding system stream. The JPSEC normative tool for authentication shares these characteristics and thus also results in a JPEG 2000 Core coding system compliant codestream.
+
+JPSEC allows encryption and decryption to be performed on JPEG 2000 and JPSEC codestreams. When encryption is used, the JPEG 2000 data is of course changed. Strictly speaking, the Core coding system compliance is not possible with encrypted streams since it will most likely cause a JPEG 2000 Core coding system decoder to encounter disallowed values. One possible way of overcoming or at least mitigating this problem is to use the error resilience capabilities of JPEG 2000. With error resilience, it can be possible to have encrypted JPSEC codestreams that have a defined behaviour for JPEG 2000 Core coding system decoders.
+
+JPSEC has a  $P_{\text{sec}}$  parameter field that contains security parameters for the entire codestream. This includes a flag  $F_{12K}$  that can be set to 1 to indicate that a JPSEC codestream is decodable by JPEG 2000 Core coding system decoders. A JPSEC creator can set this parameter as it applies JPSEC tools to the JPEG 2000 codestream. It was mentioned that a JPSEC creator can accept a protected JPSEC codestream as input. If a JPSEC creator receives an input JPSEC codestream which has the  $F_{12K}$  flag set to indicate the Core coding system compliance and then applies a JPSEC tool that loses the Core coding system compliance, it shall set the  $F_{12K}$  flag to 0.
+
+For JPSEC streams that are not Core coding system compliant, it is recommended to use a file extension of .jp2s to indicate that a JPEG 2000 Core coding system decoder might not be able to decode the protected codestream.
+
+JPEG 2000 Core coding system on the extended capabilities marker segment (CAP) can be used to indicate that JPSEC is used. Specifically, the Core coding system uses  $R_{\text{siz}}$  parameter to indicate the presence of a CAP marker segment, which contains a  $C_{\text{cap}}$  parameter that can be used to signal which JPEG 2000 parts are used in the codestream. One can specify that Rec. ITU-T T.807 | ISO/IEC 15444-8 (JPSEC) is used by setting an appropriate bit in  $C_{\text{cap}}$ .
+
+Thus, a JPSEC creator can set the  $R_{\text{siz}}$  parameter to indicate the presence of a CAP marker segment. It can insert or edit the CAP marker segment to set the  $C_{\text{cap}}$  parameter to indicate that JPSEC is used.
+
+**B.2 Rec. ITU-T T.808 | ISO/IEC 15444-9 – JPIP****B.2.1 General relationship between JPIP and JPSEC**
+
+JPIP specifies a protocol consisting of a structured series of interactions between a client and a server by means of which image file metadata, structure, and partial or whole image code streams can be exchanged in a communications efficient manner.
+
+JPIP can be tailored via the various extensions to the JPEG 2000 file format, as defined in Rec. ITU-T T.801 | ISO/IEC 15444-2, Rec. ITU-T T.802 | ISO/IEC 15444-3 and Rec. ITU-T T.805 | ISO/IEC 15444-6. However, to achieve a simple level of interactivity that allows portions of a single JPEG 2000 file or codestream to be transferred, these other capabilities are not mandated.
+
+Provisions have been included for the extension of the JPIP protocol to support the current JPEG 2000 Standards ITU-T Rec. T.802 | ISO/IEC 15444-3, Motion JPEG 2000, and Rec. ITU-T T.805 | ISO/IEC 15444-6, Compound Documents, and the future extensions of JPEG 2000 (currently JP3D, JPSEC, and JPWL).
+
+JPSEC provides security services for JPEG 2000 images. The JPSEC syntax supports two types of markers: SEC and INSEC. One or more SEC markers appear in the main header of JPSEC bit stream. In other words, JPSEC consumes a
+
+JPEG 2000 codestream, modifies the JPEG 2000 main header to form a new JPSEC "main header", and modifies the corresponding JPEG 2000 data stream to form a new protected data stream if applicable. INSEC markers can appear in the "data" portion of the data stream. It specifies some "smaller size" or "local area" parameters compared to SEC marker and can be used to complement the SEC marker.
+
+It is observed that JPIP is just beyond the transport layer, while JPSEC is at the application layer. From this point of view, JPIP provides a transport service to JPSEC. That is, the JPIP offers efficient tools to deliver image information, including main header (all of the markers) and codestreams, between servers and clients. This clause considers how JPIP can be used to transport JPSEC content.
+
+### B.2.2 Specific issues on interactivity between JPIP and JPSEC
+
+This clause describes the issues that a JPIP sender and receiver consider to transport JPSEC content.
+
+In Rec. ITU-T T.808 | ISO/IEC 15444-9, both JPP- and JPT-stream media types use the main header data-bin. This data-bin consists of a concatenated list of all markers and marker segments in the main header, starting from the SOC marker. It contains no SOT, SOD or EOC markers. However, the main header of JPEG 2000 does not include a SEC marker and its segment. As a result, Rec. ITU-T T.808 | ISO/IEC 15444-9 does not specify support for the SEC marker segment specified in JPSEC. Thus, a JPIP sender and receiver shall recognize the SEC marker segment(s) that appear in the main header of a JPSEC codestream.
+
+Rec. ITU-T T.808 | ISO/IEC 15444-9 describes its support to the precinct data. However, Rec. ITU-T T.808 | ISO/IEC 15444-9 does not specify if it supports INSEC marker and its segment specified in JPSEC. Thus, a JPIP sender and receiver shall recognize the INSEC marker segment that can appear in the data portion of a JPSEC codestream.
+
+In Rec. ITU-T T.808 | ISO/IEC 15444-9, the tile header data-bins appear only within the JPP-stream media type. For data-bins belonging to this class, the in-class identifier holds the index (starting from 0) of the tile to which the data-bin refers. This data-bin consists of markers and marker segments for tile n. It shall not contain an SOT marker segment. Inclusion of SOD markers is optional. This data bin can be formed from a valid codestream, by concatenating all marker segments except SOT and POC in all tile-part headers for tile n.
+
+In Rec. ITU-T T.808 | ISO/IEC 15444-9, the tile data-bins shall be used only with the JPT-stream media type. For data-bins belonging to this class, the in-class identifier is the index (starting from 0) of the tile to which the data-bin belongs. Each tile data-bin corresponds to the string of bytes formed by concatenating all tile-parts belonging to the tile, in order, complete with their SOT, SOD and all other relevant marker segments.
+
+As mentioned above, Rec. ITU-T T.808 | ISO/IEC 15444-9 describe the support to the tile-part header and tile-part data. However, Rec. ITU-T T.808 | ISO/IEC 15444-9 do not specify if they support SEC marker segments and INSEC marker segments. Thus, a JPIP sender and receiver shall recognize and transport these marker segments along with the protected data.
+
+### B.2.3 Summary
+
+Generally speaking, JPSEC makes itself suitable to be transported by JPIP. INSEC marker is used in the codestream to describe some "small" specific data part that is protected by security tool/tools. It makes JPSEC more flexible. To make INSEC more robust, the service layer (currently JPIP) should provide the good Quality of Service or protection on the INSEC marker and its segment. In order to achieve this goal, JPIP and JPSEC need to work out some issues and make sure the interactivity between JPIP and JPSEC.
+
+## B.3 Rec. ITU-T T.810 | ISO/IEC 15444-11 – JPWL
+
+Wireless JPEG 2000 or JPWL (Rec. ITU-T T.810 | ISO/IEC 15444-11) extends the baseline JPEG 2000 specification to achieve the efficient transmission of JPEG 2000 imagery over an error-prone transmission environment. More specifically, JPWL defines a set of tools and methods to protect the codestream against transmission errors. It also defines means to describe the sensitivity of the codestream to transmission errors, and to describe the locations in the codestream of residual transmission errors.
+
+JPWL is notably addressing the protection of the image header, Forward Error Correcting (FEC) codes, Unequal Error Protection (UEP), joint source-channel coding, data partitioning and interleaving, and robust arithmetic coding. JPWL is not linked to a specific network or transport protocol, but provides a generic solution for the robust transmission of JPEG 2000 imagery over error-prone networks.
+
+The main functionalities of JPWL are:
+
+- to protect the codestream against transmission errors;
+- to describe the degree of sensitivity of different parts of the codestream to transmission errors;
+- to describe the locations of residual errors in the codestream.
+
+JPWL defines four marker segments: Error Protection Capability (EPC), Error Protection Block (EPB), Error Sensitivity Descriptor (ESD) and Residual Error Descriptor (RED).
+
+The EPC marker segment indicates which JPWL normative and informative tools are used in the codestream. More specifically, EPC signals whether the three other normative marker segments defined by JPWL, namely the error sensitivity descriptor (ESD), the residual error descriptor (RED) and the error protection block (EPB) are present in the codestream. Furthermore, EPC signals the use of informative tools which have been previously registered with the JPWL RA. EPC is always present in a JPWL codestream.
+
+The primary function of EPB is to protect the Main and Tile-part header. However, it can also be used to protect the remaining of the codestream. The EPB marker segment contains information about the error protection parameters and redundancy data used to protect the codestream against errors.
+
+The ESD marker segment contains information about the sensitivity of codestream to errors. This information can be exploited when applying an Unequal Error Protection (UEP) technique. Straightforwardly, more powerful codes are used to protect the most sensitive portion of the codestream. This information can also be used for selective retransmissions. Finally, the information carried in ESD could also be used for other non-JPWL applications such as efficient rate transcoding or smart prefetching.
+
+The RED marker segment signals the presence of residual errors in the codestream. Indeed, a JPWL decoder can fail to correct all the errors in a codestream. RED allows signalling the location of such residual errors. This information can then be exploited by a JPEG 2000 decoder in order to better cope with errors. For instance, the decoder could request retransmission, conceal the errors or discard the corrupted information.
+
+### B.3.1 General relationship between JPWL and JPSEC
+
+The combination of JPWL and JPSEC, as shown in Figure B.1, is used whenever JPEG 2000 images need to be secured and transmitted over an error-prone wireless channel.
+
+At the transmitter side, JPWL error sensitivity is typically generated during JPEG 2000 encoding. JPSEC tools are then applied to the codestream in order to secure it. Finally, JPWL encoding tools are used to make the codestream more robust to transmission errors.
+
+At the receiver side, JPWL decoding tools are first applied to correct possible transmission errors. During this step, JPWL can also generate residual errors information. Finally, JPSEC tools are applied in order to fulfil the selected security services.
+
+![Figure B.1: Typical JPWL and JPSEC combination flowchart. The process starts with an 'image' input to a 'JPEG 2000 encoder'. The output goes to 'JPWL error sensitivity', then to 'JPSEC creator'. A numbered arrow '1' leads to 'JPWL encoder', which outputs 'JPSEC/JPWL codestream'. This codestream passes through an 'error-prone wireless channel'. The output is 'JPSEC/JPWL codestream with possible errors', which goes to a 'JPWL decoder'. A numbered arrow '2' leads to 'JPWL residual errors', which then goes to a 'JPSEC consumer'.](a6f9ef297168667527ab18da412f917d_img.jpg)
+
+```
+
+graph TD
+    image --> J2000[JPEG 2000 encoder]
+    J2000 --> JPWL_sens[JPWL error sensitivity]
+    JPWL_sens --> JPSEC_creator[JPSEC creator]
+    JPSEC_creator -- 1 --> JPWL_encoder[JPWL encoder]
+    JPWL_encoder --> JPSEC_JPWL[JPSEC/JPWL codestream]
+    JPSEC_JPWL --> channel[error-prone wireless channel]
+    channel --> JPSEC_JPWL_errors[JPSEC/JPWL codestream with possible errors]
+    JPSEC_JPWL_errors --> JPWL_decoder[JPWL decoder]
+    JPWL_decoder -- 2 --> JPWL_residual[JPWL residual errors]
+    JPWL_residual --> JPSEC_consumer[JPSEC consumer]
+  
+```
+
+T.807(23)\_FB.1
+
+Figure B.1: Typical JPWL and JPSEC combination flowchart. The process starts with an 'image' input to a 'JPEG 2000 encoder'. The output goes to 'JPWL error sensitivity', then to 'JPSEC creator'. A numbered arrow '1' leads to 'JPWL encoder', which outputs 'JPSEC/JPWL codestream'. This codestream passes through an 'error-prone wireless channel'. The output is 'JPSEC/JPWL codestream with possible errors', which goes to a 'JPWL decoder'. A numbered arrow '2' leads to 'JPWL residual errors', which then goes to a 'JPSEC consumer'.
+
+Figure B.1 – Typical JPWL and JPSEC combination
+
+### B.3.2 Specific issues on interoperability between JPWL and JPSEC
+
+A number of issues are important to consider for interoperability between JPWL and JPSEC, as detailed hereafter:
+
+- 1) JPWL Error Protection Capability (EPC): The presence of this marker segment will affect byte ranges. Note that this marker segment is always present in a JPWL codestream.
+- 2) JPWL Error Protection Block (EPB): This marker segment is typically added as the last step at the transmitter and removed as the first step at the receiver. In principle, it should not affect JPSEC.
+- 3) JPWL Error Sensitivity Descriptor (ESD): This marker segment is typically added during JPEG 2000 Core coding system encoding, in which case it will be transparent to subsequent JPSEC operations. However,
+
+JPSEC could adversely affect the use of ESD in JPWL. In particular, JPSEC should not change byte ranges whenever ESD uses byte ranges. In addition, the JPSEC operations should not affect distortion values; otherwise the information carried by ESD becomes irrelevant. In the latter case, the JPSEC creator has the option to remove the ESD marker segment.
+
+- 4) JPWL Residual Error Descriptor (RED): This marker segment can be inserted after JPWL decoding. It can therefore affect JPSEC byte ranges. It can also impact JPSEC authentication techniques. In case of a corrupted codestream, the RED information can be useful for a JPSEC consumer to appropriately handle it.
+- 5) JPSEC SEC: The presence of this marker segment will affect byte ranges. Note that this marker segment is always present in a JPSEC codestream.
+- 6) JPSEC INSEC: The presence of this marker segment will affect byte ranges. Note that this marker segment appears in the codestream data.
+
+In the case when there are no residual errors, the JPWL encoder and decoder should ideally be transparent. In other words, in this case, the streams at points 1 and 2 in the above figure should be strictly identical.
+
+As a general recommendation, when used in combination with JPWL, it is preferable for JPSEC to use byte ranges beginning after SOD marker in order to minimize problems with byte ranges. In addition, it is preferable to restrict the presence of JPWL marker segments to the Main header and to avoid their presence in the Tile-part headers.
+
+## Annex C
+
+## File format security
+
+(This annex forms an integral part of this Recommendation | International Standard.)
+
+## C.1 Scope
+
+This annex specifies JPSEC file format derived from the ISO base file format and modifications to JPEG family file format (including JP2, JPX and JPM) for protection and secure adaptation of scalable pictures, which is possibly encrypted and/or authenticated by the owner. The pictures could be either static pictures or time-sequenced pictures. In particular, this annex provides functionality to do the following:
+
+- To store coded media data corresponding to different scalability levels. Elementary stream (ES) is used for this purpose. There are three types of ESs, self-contained ES, scalable composed ES and decodable composed ES.
+- To define tracks describing the characteristics of the coded media data stored in ES. For example, the track should be able to indicate scalability level (resolution, layer, region, etc.) and the rate-distortion hints of the coded media data in order to facilitate easy and secure adaptation.
+- To define new file format boxes to signal protection tools and parameters applied to coded media data or metadata. The protection tools can be applied to either static JPEG 2000 pictures or time-sequenced JPEG 2000 pictures.
+- The protection tools defined in this Recommendation | International Standard can be applied to JPEG family file formats including JP2, JPX and JPM and ISO-derived file formats such as MJ2 for Motion JPEG.
+
+## C.2 Introduction
+
+### C.2.1 Security protection at file format level
+
+This annex describes a JPSEC file format derived from the ISO base file format and modifications to JPEG family file format, to add security protection to JPEG 2000 pictures at the file format level. The protection applied at the file format level can be classified into two types: item-based protection and sample-based protection, both structures are defined by the ISO base file format. The item-based protection is designed to protect any byte ranges (including coded media data and metadata) while the sample-based protection is designed to protect time-sequenced media including JPEG 2000 pictures.
+
+When the security tools applied change the data length, it shall update all pointers and length fields in all boxes, to ensure correct parsing by the reader.
+
+### C.2.2 Item-based protection
+
+This annex describes two item-based protection schemes in the ISO base file format, by leveraging the syntax and structures specified by this Recommendation | International Standard. Specifically, it describes schemes for decryption and authentication. Each item in the ItemLocationBox is protected by one or more protection schemes in the ItemProtectionBox. When multiple schemes are used (or chained together), the order in which they are applied can be significant and thus shall be specified. This annex also specifies how such operations should be chained together. In addition, the ItemDescriptionBox and ItemCorrespondingBox are added into the ISO base file format to allow the flexible processing properties that are provided by JPSEC. Specifically, the ItemDescriptionBox allows media-dependent metadata (such as resolution, quality layer, spatial region, and color space component) to be associated with different portions of the file. These descriptions can be provided regardless of whether protection is applied. When used with scalable coded pictures, this allows the file to be scaled down or transcoded without parsing or decoding the media data. In cases where protection is applied, this provides the benefit of enabling transcoding without requiring decryption.
+
+### C.2.3 Sample-based protection of scalable media
+
+For time-sequenced pictures, this annex adds syntaxes to facilitate scalability at the file format level, including scalable composed elementary stream (ES), decodable composed ES, pointer structure, container structure and ByteData structure. The scalable coded pictures can be divided (either physically or virtually) into elementary streams at different scalability level, such that the adaptor/transcoder can "thin" media data with low complexity.
+
+Figure C.1 gives an overview of the file format specified by this annex and also shows how the specified FF is used to adapt the media data.
+
+Given a sequence of JPEG 2000 pictures (also referred to as *Self-contained ES*), there are two approaches to construct the file format. In the first approach, the MDAT box contains one or more *Scalable Composed ESs*, each of which corresponds to one scalability level of the media data, e.g., a resolution or a layer. The scalable composed ES shall be stored in MDAT box that is co-located with the file format. The self-contained ES can be located in either MDAT box in the same file, or a different file whose format is not specified in this Recommendation | International Standard. The scalable composed ES might not be decodable by itself, it might need to be combined with other scalable composed ESs to generate fully decodable JPEG 2000 pictures. In the second approach, the MDAT box contains one or more *Decodable Composed ESs*, and each ES constitutes fully decodable JPEG 2000 pictures by itself. Similarly, decodable composed ESs shall be stored in MDAT box co-located with the file format, and the self-contained ES can be stored in either MDAT box in the same file, or a different file whose format is not specified by this annex.
+
+Each scalable composed ES or decodable composed ES shall be described by at least one track. The characteristics of the ES (like resolution, layer, and region) are indicated in SampleEntryBox inside each track.
+
+To generate a fully decodable JPEG 2000 codestream from scalable composed ESs, a JPEG 2000-aware adaptor should have the capability to dynamically generate the image headers (based on the number of resolutions, layers and region in the adapted codestream), to insert empty packets or to insert POC markers as needed to make the resulting codestream decodable by any standard decoder. However, if a simple adaptor is used, the resulting codestream can have an inconsistent image header and there can be a missing packet, which require a JPEG 2000 adaptive-format decoder.
+
+As a decodable composed ES is decodable by itself, a simple adaptor is sufficient to generate fully compliant JPEG 2000 pictures.
+
+![Figure C.1 – System diagram for time-sequenced scalable media. The diagram illustrates two paths for processing a sequence of samples (1-8). The left path uses a 'JPEG 2000 aware adaptor' to process 'Scalable composed ES' (e.g., R0, R1, ..., RM-1) from 'Track 1' to 'Track N' within an 'MDAT box'. The right path uses a 'Simple adaptor' to process 'Decodable composed ES' (e.g., R0, R0R1, ..., R0R1...RM-1) from 'Track 1' to 'Track N' within an 'MDAT box'. Both paths lead to a 'JPEG 2000 decoder'.](60a40901e77feeb97ab6cf9c6d9418c3_img.jpg)
+
+The diagram illustrates two system architectures for processing time-sequenced scalable media. At the top, a sequence of samples (1 to 8) is shown, with a bracket indicating they are 'Self-contained ES (JPEG 2000 frames)'. Two arrows point from this sequence to two main processing blocks.
+
+**Left Block (Scalable Composed ES Path):**
+
+- Contains multiple tracks: Track 1, Track 2, ..., Track N.
+- An 'MDAT box' containing 'Scalable composed ES 1 (e.g.,  $R_0$ )', 'Scalable composed ES 2 (e.g.,  $R_1$ )', ..., 'Scalable composed ES M (e.g.,  $R_{M-1})$ '.
+- An optional 'Self-contained ES (JPEG 2000) (optional)' box below the MDAT box.
+- An arrow points from this block to a 'JPEG 2000 aware adaptor' box, which then points to a 'JPEG 2000 decoder' box.
+
+**Right Block (Decodable Composed ES Path):**
+
+- Contains multiple tracks: Track 1, Track 2, ..., Track N.
+- An 'MDAT box' containing 'Decodable composed ES 1 (e.g.,  $R_0$ )', 'Decodable composed ES 2 (e.g.,  $R_0R_1$ )', ..., 'Decodable composed ES M (e.g.,  $R_0R_1...R_{M-1})$ '.
+- An optional 'Self-contained ES (JPEG 2000) (optional)' box below the MDAT box.
+- An arrow points from this block to a 'Simple adaptor' box, which then points to a 'JPEG 2000 decoder' box.
+
+The text 'T.803(23)\_FC.1' is located at the bottom right of the diagram area.
+
+Figure C.1 – System diagram for time-sequenced scalable media. The diagram illustrates two paths for processing a sequence of samples (1-8). The left path uses a 'JPEG 2000 aware adaptor' to process 'Scalable composed ES' (e.g., R0, R1, ..., RM-1) from 'Track 1' to 'Track N' within an 'MDAT box'. The right path uses a 'Simple adaptor' to process 'Decodable composed ES' (e.g., R0, R0R1, ..., R0R1...RM-1) from 'Track 1' to 'Track N' within an 'MDAT box'. Both paths lead to a 'JPEG 2000 decoder'.
+
+Figure C.1 – System diagram for time-sequenced scalable media
+
+Each elementary stream is described by at least one media track, and its characteristics are described in SampleDescriptionEntry or SampleGroupEntryBox within the track. It is possible that a single elementary stream is described by multiple tracks, each of which can describe different aspects of the elementary stream.
+
+The sample-based protection can be applied to all samples or a group of samples in a scalable composed ES or decodable composed ES. If protection is applied to all samples, a ProtectionSchemeInfoBox signalling the parameters of the protection tool is added to the SampleDescriptionBox, which is then encapsulated as described in C.5.2. In addition, if protection is applied to a group of samples, a ProtectionSchemeInfoBox is added to their SampleGroupEntryBox, which is then encapsulated as described in C.5.4.
+
+### C.3 Extension to ISO base media file format
+
+#### C.3.1 Overview
+
+C.3.2 to C.3.10 document technical extensions (additional box types) to the ISO based media file format, which could be used for protection, adaptation, or secure adaptation of scalable coded pictures. However, the added box types could be used for other purposes as well. In particular, this clause defines ProtectionSchemeInfoBox for the decryption tool and authentication tool, ItemDescriptionBox, ScalableSampleDescriptionEntry, ScalableSampleGroupEntry, and Generic Protected Box. All other boxes defined in ISO/IEC 14496-12 are still used as is.
+
+#### C.3.2 Incorporate JPSEC codestream into ISO-driven file format
+
+A JPSEC codestream can be placed as a payload in the 'mdat' box of the ISO base file format. In the Sample Description Box ('stsd'), the 'codingname' of the corresponding Sample Entry is defined to be 'jpsc', which is a registered identifier for JPSEC decoder. In this case, the security service is provided by JPSEC at codestream.
+
+#### C.3.3 Protected file format brand
+
+Files conforming to this Recommendation | International Standard can use 'ffsc' as the major brand in the File Type Compatibility Box.
+
+Files conforming to this Recommendation | International Standard, i.e., containing protection or authentication information can use 'ffsc' as a compatible brand in the File Type Compatibility Box.
+
+There are uses of this Recommendation | International Standard which are compatible with JP2, JPX, MJ2, and JPM files. A typical use of this Recommendation | International Standard will leave the major brand of a file unchanged, but add boxes and thus add 'ffsc' as a compatible brand.
+
+Thus, brands including 'isom', 'iso2', 'jp2\040', 'jpx\040' and 'jpm\040' should be compatible.
+
+The 'ffsc' compatible brand indicates the use of new boxes and new tools corresponding to the protection methods in JPSEC.
+
+A file that has been protected, to the extent that an application intending to process the JP2, JPX, JPM, or other file type content will be unable to do so without using protection tools, can use the 'ffsc' major brand as the file type; such a protected file shall not use a major brand for which it is no longer conformant.
+
+#### C.3.4 Summary of boxes used
+
+The ISO base media file format defines two structures to describe a presentation: the logical structure and media sequence structure. The logical structure uses the ItemLocationBox ('iloc') to describe an item which is the byte range or a series of byte ranges for a particular file, either a local file or a remote file. The media sequence structure uses the SampleGroupDescriptionBox ('spgd') or SampleDescriptionBox ('stsd') to describe the samples, which could be a frame of video, a time-contiguous series of video frames, or a time-contiguous compressed section audio.
+
+Accordingly, the protection in the ISO base media file format level is classified into item-based protection and sample-based protection, as described in C.5.2 and C.5.4, respectively.
+
+Several boxes are used from ISO/IEC 14496-12, these are marked as "Existing" in Table C.1. Boxes defined in this Recommendation | International Standard are listed as "New" in Table C.1. The definitions for these boxes depend on the definitions of Box and FullBox from ISO/IEC 14496-12, which are repeated for convenience in C.7.
+
+**Table C.1 – List of existing and new boxes**
+
+| Box names |      |      |      |      |  | Status   | Remarks                           |
+|-----------|------|------|------|------|--|----------|-----------------------------------|
+| meta      |      |      |      |      |  | Existing | Metadata                          |
+|           | iloc |      |      |      |  | Existing | Item location                     |
+|           | ipro |      |      |      |  | Existing | Item protection                   |
+|           |      | sinf |      |      |  | Existing | Protection scheme information box |
+|           |      |      | frma |      |  | Existing | Original format box               |
+|           |      |      | schm |      |  | Existing | Scheme type box                   |
+|           |      |      | schl |      |  | Existing | Scheme information box            |
+|           |      |      |      | gran |  | New      | Granularity box                   |
+|           |      |      |      | vall |  | New      | Value List box                    |
+|           |      |      |      | bcip |  | New      | Block cipher box                  |
+
+Table C.1 – List of existing and new boxes
+
+| Box names |      |                                |     |      |      | Status   | Remarks                           |
+|-----------|------|--------------------------------|-----|------|------|----------|-----------------------------------|
+|           |      |                                |     |      | keyt | New      | Key template box                  |
+|           |      |                                |     | scip |      | New      | Stream cipher box                 |
+|           |      |                                |     |      | keyt | New      | Key template box                  |
+|           |      |                                |     | auth |      | New      | Authentication box                |
+|           |      |                                |     |      | keyt | New      | Key template box                  |
+|           | iinf |                                |     |      |      | Existing | Item information box              |
+|           | ides |                                |     |      |      | New      | Item description box              |
+|           |      | dest                           |     |      |      | New      | Description type box              |
+|           |      | desd                           |     |      |      | New      | Description data box              |
+|           |      | vide                           |     |      |      | New      | Visual item description entry     |
+|           |      | j2ke                           |     |      |      | New      | JPEG 2000 item description entry  |
+|           | icor |                                |     |      |      | New      | Item correspondence box           |
+| ...       | ...  | ...                            | ... | ...  | ...  | ...      | ...                               |
+| stbl      |      |                                |     |      |      | Existing | Sample table box                  |
+|           | stsd |                                |     |      |      | Existing | Sample description box            |
+|           |      | ScalableSampleDescriptionEntry |     |      |      | New      | Scalable sample description entry |
+|           | sbgp |                                |     |      |      | Existing | Sample to group box               |
+|           | sgpd |                                |     |      |      | Existing | Sample group box                  |
+|           |      | ScalableSampleGroupEntry       |     |      |      | New      | Scalable sample group entry       |
+| gpri      |      |                                |     |      |      | New      | Generic Protected box             |
+
+### C.3.5 Decryption scheme
+
+The Decryption protection scheme is identified in SchemeTypeBox as follows:
+
+```
+scheme_type="decr"
+```
+
+```
+scheme_version=0
+```
+
+```
+scheme_uri=null
+```
+
+For the Decryption protection scheme, the structure of SchemeInfoBox is as follows:
+
+```
+aligned(8) class GranularityBox() extends Box('gran') {
+    unsigned int(8) granularity;
+}
+```
+
+Semantics:
+
+`granularity` is used for item-based protection. For item-based protection, 0 indicates that the processing unit is the entire item and 1 indicates that the processing unit is one extent within an item. For sample-based protection, 0 indicates that the processing unit is all samples in the track or sample group and 1 indicates that the processing unit is one sample.
+
+```
+aligned(8) class ValueListBox() extends Box('vall') {
+    unsigned int(8) value_size;
+    unsigned int(16) value_count;
+    unsigned int(16) count[value_count];
+    unsigned char(value_size) value[value_count];
+}
+```
+
+Semantics:
+
+`value_size` is the size in bytes of each value in the array.
+
+`value_count` is the number of (`count`, `value`) pairs in the array. For item-based protection, the (`count`, `value`) pairs are used to map each value to `count` processing units. For sample-based protection, the (`count`, `value`) pairs are used to map each value to `count` samples. For instance, the `value[0]` corresponds to the first `count[0]` sample or units, and the `value[1]` corresponds to the next `count[1]` samples or units, and so on.
+
+```
+aligned(8) class KeyTemplateBox() extends Box('keyt') {
+    unsigned int(16)    key_size;
+    unsigned int(8) key_info;
+    GranularityBox()    GL;                //optional
+    ValueListBox()    VL;
+}
+```
+
+Semantics:
+
+`key_size` is the size of key in bits.
+
+`key_info` indicates the meaning of the values in the `ValueListBox`. 1 means the values are ITU-T X.509 certificate; 2 means the values are URIs for certificate or secret keys.
+
+GL is a **GranularityBox**() .
+
+VL is a **ValueListBox**() , containing a list of values, whose meaning is defined by the `key_info` field.
+
+```
+aligned(8) class BlockCipherBox() extends Box('bcip') {
+    unsigned int(16)    cipher_id;
+    bit(6)             cipher_mode;
+    bit(2)             padding_mode;
+    unsigned int(8) block_size;
+    KeyTemplateBox()    KT;
+}
+```
+
+Semantics:
+
+`cipher_id` identifies which block cipher algorithm is used for protection. Values are defined in Table 25.
+
+`cipher_mode` could be ECB, CBC, CFB, OFB or CTR. Values are defined in Table 29.
+
+`padding_mode` is ciphertext stealing or PKCS#7-padding. Values are defined in Table 30.
+
+`block_size` is size of block for block cipher.
+
+KT is a **KeyTemplateBox**() , holding all the key information used by the block cipher.
+
+```
+aligned(8) class StreamCipherBox() extends Box('scip') {
+    unsigned int(8) cipher_type;
+    unsigned int(16)    cipher_id;
+    KeyTemplateBox()    KT;
+}
+```
+
+Semantics:
+
+`cipher_type` indicates the type of cipher used. It has values `cipher_type = STRE` for stream cipher or `cipher_type = ASYM` for asymmetric cipher.
+
+`cipher_id` identifies the stream cipher algorithm used for the protection. If `cipher_type = STRE`, see Table 26; if `cipher_type = ASYM`, see Table 27.
+
+KT is a **KeyTemplateBox**() , holding all the key information used by the stream cipher.
+
+```
+aligned(8) class SchemeInfomationBox() extends Box('schi', cipher_id) {
+    unsigned int(8) MetaOrMedia;
+    unsigned int(8) HeaderProtected;
+    BlockCipherBox(); or StreamCipherBox();
+    GranularityBox()    GL;
+    ValueListBox()    VL;
+}
+```
+
+Semantics:
+
+`MetaOrMedia` is to indicate whether the protected data segment corresponds to media data segment or meta data boxes. (0 for media data and 1 for meta data boxes).
+
+`HeaderProtected` is to indicate whether the protection is applied to the box content only (value 0) or applied to the whole box including its header (value 1).
+
+The `SchemeInformationBox` can contain a **BlockCipherBox**() , or a **StreamCipherBox**() , which are containers for the parameters of the cipher algorithms. These boxes can only contain particular `cipher_id` values.
+
+GL is a **GranularityBox** (), holding information about the processing unit. This field is optional for sample-based protection and required for item-based protection.
+
+VL is a **ValueListBox** (). For block cipher, this box can be empty. For stream cipher, this box contains all the initial vectors.
+
+### C.3.6 Authentication scheme
+
+The Authentication protection scheme is identified by SchemeTypeBox as follows:
+
+```
+scheme_type="auth"
+```
+
+```
+scheme_version=0
+```
+
+```
+scheme_uri=null
+```
+
+For Authentication protection scheme, the structure of SchemeInfoBox is defined as follows:
+
+```
+aligned(8) class AuthBox() extends Box('Auth') {
+    unsigned int(8) auth_type; //hash, cipher, or signature
+    unsigned int(8) method_id;
+    unsigned int(8) hash_id;
+    unsigned int(16) MAC_size;
+    KeyTemplateBox() KT;
+}
+```
+
+Semantics:
+
+auth\_type indicates authentication type, including hash-based (HASH), cipher-based (CIPH) and signature-based (SIGN) authentication.
+
+method\_id identifies the authentication method. 1 indicates HMAC. If auth\_type = HASH, see Table 36; if auth\_type = CIPH, see Table 39; if auth\_type = SIGN, see Table 41.
+
+hash\_id identifies the hash function used. If auth\_type = HASH or SIGN, see Table 37; if auth\_type = CIPH, see Table 25.
+
+MAC\_size is size of MAC (if auth\_type = HASH or CIPH) or digital signature (if auth\_type = SIGN) in bits.
+
+KT is a **KeyTemplateBox** (), holding all the key information for the authentication.
+
+```
+aligned(8) class SchemeInfoBox() extends Box('schi', auth_method) {
+    unsigned char (8) auth_method;
+    AuthBox() authBox;
+    GranularityBox() GL; //optional
+    ValueListBox() VL;
+}
+```
+
+Semantics:
+
+auth\_method identifies the authentication method used. 0 is for hash-based MAC; 1 is for cipher-based MAC; 2 is for digital signature. Depending on the auth\_method, this box could contain either **HashAuthBox** (), **CipherAuthBox** (), or **SignatureAuthBox** () .
+
+GL is a **GranularityBox** (). The field is optional for sample-based protection and required for item-based protection.
+
+VL is a **ValueListBox** (), holding all the MACs or signatures.
+
+### C.3.7 ItemDescriptionBox
+
+In the Item Location Box, all the items are specified as byte ranges (using the offset and length). The 'iloc' box does not contain the content-related information about the specified byte ranges, which is used by some protection methods. For instance, if secure transcoding method wants to discard the least important layer or resolution, it has to know which byte ranges correspond to the to-be-discarded layer or resolution.
+
+As such, this clause defines two new boxes to enable the content-related processing at the file format level: Item Description Box ('ides') and Item Correspondence Box ('icor'). The 'ides' box specifies the content-related information, like layer, resolution (for visual content), period (audio content), and so on. The 'icor' box links the content-related information to the items in 'iloc' box, in the same way as the 'iinf' box links 'iloc' box to 'ipro' box.
+
+The Item Description box ('ides') is defined as follows:
+
+```
+aligned(8) class ItemDescriptionBox() extends Box('ides') {
+    unsigned int(32)    entry_count;
+    for(i=0; i < entry_count; i++) {
+        DescriptionTypeBox()    desType;
+        unsigned int(32)    item_ID;
+        DescriptionDataBox()    desData;
+    }
+}
+```
+
+Semantics:
+
+entry\_count is the number of entries in the **ItemDescriptionBox** ().
+
+item\_ID references an Item in **ItemLocationBox** (). If this field is 0, then item\_ID will be specified by **ItemCorrespondenceBox** ().
+
+```
+aligned(8) class DescriptionTypeBox() extends Box('dest') {
+    Unsigned int(32)    description_type;
+    Unsigned int(32)    description_version;
+    Unsigned int(8) description_uri[];
+}
+```
+
+Semantics:
+
+description\_type is the 4CC code defining the description scheme.
+
+description\_version is the version of the description.
+
+description\_uri allows for the options of directing the user to a webpage if they do not have the description definition installed on their system. It is an absolute URI formed as a null-terminated string in UTF-8 characters.
+
+```
+Aligned(8) class DescriptionDataBox() extends Box('desd') {
+    Box() description_specific_data [];
+}
+```
+
+Semantics:
+
+If description\_type = 'vide', this is a **VisualItemDescriptionEntry**(); if description\_type = 'j2ke', this is a **J2KItemDescriptionEntry**(); for any other value of description\_type, the syntax of the description can be found at description\_uri.
+
+The **VisualItemDescriptionEntry** () is defined as follows:
+
+```
+aligned(8) Class VisualItemDescriptionEntry extends Box('vide') {
+    unsigned int(16)    layer_start;
+    unsigned int(16)    layer_count;
+    unsigned int(16)    res_start;
+    unsigned int(16)    res_count;
+    unsigned int(16)    horizontal_offset;
+    unsigned int(16)    horizontal_length;
+    unsigned int(16)    vertical_offset;
+    unsigned int(16)    vertical_length;
+    unsigned int(16)    color_space;
+    unsigned int(16)    time_start;
+    unsigned int(16)    time_length;
+}
+```
+
+Semantics:
+
+The layer\_start and layer\_count together specify the range of layers. When layer\_start equals to  $2^{16}-1$ , the layer range will start from layer 0; when layer\_count equals to  $2^{16}-1$ , the layer range will end at the last layer. When both layer\_start and layer\_count equal to  $2^{16}-1$ , the layer range will include all layers.
+
+The `res_start` and `res_count` together specify the range of resolutions. The semantics is the same as `layer_start` and `layer_count` when their value equals to  $2^{16}-1$ .
+
+The `horizontal_offset`, `horizontal_length`, `vertical_offset` and `vertical_length` together specify the spatial area. The semantics is the same as `layer_start` and `layer_count` when their value equals to  $2^{16}-1$ .
+
+The `color_space` specifies the color space. 0: red color space; 1: green color space; 2: blue color space.
+
+The intersection is applied to the layer ranges, resolution ranges, areas and color space to get the portion of the image/video specified by the **VisualItemDescriptionEntry** ().
+
+The **J2KItemDescriptionEntry** () is defined as follows:
+
+```
+aligned(8) class J2KItemDescriptionEntry() extends Box('j2ke') {
+    VisualItemDescriptionEntry()    visualDesEntry; //optional
+    unsigned int(16)                tile_start;
+    unsigned int(16)                tile_count;
+    unsigned int(16)                precinct_start;
+    unsigned int(16)                precinct_count;
+    unsigned int(16)                j2k_packet_start;
+    unsigned int(16)                j2k_packet_count;
+}
+```
+
+Semantics:
+
+**visualDesEntry** () specifies image/video-specific attributes. It is optional.
+
+`tile_start` and `tile_count` specify the tiles.
+
+`precinct_start` and `precinct_count` specify the precincts.
+
+`j2k_packet_start` and `j2k_packet_count` specify the JPEG 2000 defined packets.
+
+Similar to **VisualItemDescriptionEntry** (), the intersection is applied to tiles, precincts and JPEG 2000 packets to get the portion of the JPEG 2000 codestream specified by **J2KItemDescriptionEntry** ().
+
+The **ItemCorrespondenceBox** ('icor') is defined as follows:
+
+```
+aligned(8) class ItemCorrespondenceEntry() extends Box('icor') {
+    unsigned int(16)                item_ID;
+    unsigned int(16)                desc_ID;
+}
+```
+
+Semantics:
+
+`item_ID` is pointing to one item in the **ItemLocationBox** ().
+
+`desc_ID` is pointing to one description entry in the **ItemDescriptionBox** ().
+
+### C.3.8 ScalableSampleDescriptionEntry Box
+
+The **ScalableSampleDescriptionEntry** () is used to describe characteristics associated with scalable composed ES or decodable composed ES, like resolution levels, quality layers, cropped region. For scalable composed ES, `res` and `layer` indicate the media data of that particular resolution and layer, while for decodable composed ES, they indicate the highest resolution and highest quality layer.
+
+When the media samples are protected by a protection tool, the **ScalableSampleDescriptionEntry** () is encapsulated as follows:
+
+The four-character-code of the **ScalableSampleDescriptionEntry** () is replaced with another four-character-code indicating protection encapsulation, which varies only by media type, as defined below:
+
+- Encv: to indicate that video samples are encrypted and thereby un-protection shall be applied to get meaningful media data.
+- Autv: to indicate that video samples are authenticated, and the media data can still be meaningful before un-protection.
+- Enct: to indicate that text samples are encrypted.
+- Autt: to indicate that text samples are authenticated.
+- Encs: to indicate that system samples are encrypted.
+- Auts: to indicate that system samples are authenticated.
+
+A **ProtectionSchemeInfoBox()** is added to the **ScalableSampleDescriptionEntry()**, leaving all other boxes unmodified.
+
+The original sample entry type is stored in the **OriginalFormatBox()** within the **ProtectionSchemeInfoBox()**.
+
+```
+class ScalableSampleDescriptionEntry(codingname) extends VisualSampleEntry(codingname) {
+    Unsigned int(8) res;
+    Unsigned int(8) layer;
+    Unsigned int(32)    cropped_width, cropped_height;
+    If(cropped_width > 0 && cropped_height > 0) {
+        Unsigned int(32)    startx;
+        Unsigned int(32)    starty;
+    }
+    ProtectionSchemeInfoBox() protectionSchemes[]; //optional
+}
+```
+
+Semantics:
+
+**codingname** is "sces" if the track is referring to a scalable composed ES and "dces" if the track is referring to a decodable composed ES.
+
+**res** is the resolution of the described samples. A value of -1 indicates all resolution levels.
+
+**layer** is the quality layer of the described samples. A value of -1 indicates all quality layers.
+
+**cropped\_width** is the width of the cropped region.
+
+**cropped\_height** is the height of the cropped region.
+
+**startx** & **starty** indicate the position of the top-left corner of the cropped region. If either **cropped\_width** or **cropped\_height** is zero, the **startx** and **starty** will not be present.
+
+**protectionSchemes** is a list of **ProtectionSchemeInfoBoxes()** to indicate the protection tools applied to the described samples. The un-protection process has to follow the order in which it appears in the list.
+
+### C.3.9 ScalableSampleGroupEntry Box
+
+A track can be made up of samples with different characteristics and protected by different protection tools or with different parameters. The **ScalableSampleGroupEntry** box is used to signal the grouping of samples based. For example, if a track has 1000 samples where the first 500 samples are encrypted with Key 1 and the second 500 samples are encrypted with Key 2, the **SampleGroupDescription()** Box contains two **ScalableSampleGroupEntry()** boxes: the first box describes the first 500 samples while the second box describes the second 500 samples.
+
+When the media samples are protected by a protection tool, the **ScalableSampleGroupEntry()** is encapsulated in the same way as **ScalableSampleDescriptionEntry()** in C.3.8.
+
+```
+class ScalableSampleGroupEntry(type) extends VisualSampleGroupEntry(type) {
+    unsigned int(8) res;
+    unsigned int(8) layer;
+    unsigned int(32)    cropped_width, cropped_height;
+    If(cropped_width > 0 && cropped_height > 0) {
+        unsigned int(32)    startx;
+        unsigned int(32)    starty;
+    }
+    ProtectionSchemeInfoBox() protectionSchemes[]; //optional
+}
+```
+
+Semantics:
+
+**type** indicates the grouping type. If the grouping is based on different protection tools applied to the samples, the type is "prot"; if the grouping is based on different media characteristics (like resolution or layers), the type is "attr".
+
+**res** is the resolution of the described samples. A value of -1 indicates all resolution levels.
+
+**layer** is the quality layer of the described samples. A value of -1 indicates all quality layers.
+
+**cropped\_width** is the width of the cropped region.
+
+**cropped\_height** is the height of the cropped region.
+
+`startx` & `starty` indicate the position of the top-left corner of the cropped region. If either `cropped_width` or `cropped_height` is zero, the `startx` and `starty` will not be present.
+
+`protectionSchemes` is a list of **ProtectionSchemeInfoBox()**s to indicate the protection tools applied to the described samples. The un-protection process has to follow the order in which it appears in the list.
+
+### C.3.10 Generic Protected Box
+
+#### C.3.10.1 Definition
+
+Box Types: 'gp<sub>prt</sub>'
+
+Container: File or any container box
+
+Mandatory: Yes, this shall be present when a protection scheme is applied to a box that would prevent parsing the file
+
+Quantity: Any number
+
+The **JProtectedBox()** is used when a protection scheme is applied to a box, and use of the protection scheme prevents parsing of the box. For example, if the contents of a superbox are encrypted, including the box lengths and types, that box is no longer parsable, and thus fails to meet the original definition for the box. In this case, a **JProtectedBox()** can be placed in the file in the place of the box that no longer parses correctly, and the encrypted data placed in the **JProtectedBox()**.
+
+Interpreting the content of the `data[]` portion of this box shall be done using the **ItemLocationBox()**.
+
+Once all of the protection methods have been operated on from the **ItemInformationBox()**, the contents can be reorganized into original boxes. The first `size[0]` bytes of the unprotected `data[]` array are placed in a box of `type[0]`, and the next `size[i]` bytes are placed in a box of `type[i]`, and so on. Note that when `size_flag` is 0, the size of the original box is not disclosed and when `type_flag` is 0, the type of the original box is not disclosed. This is to prevent known-plaintext attacks. When both the `size_flag` and `type_flag` are 0, `total_size` provides the total size of the protected content.
+
+If the entry count is 0, or if there is data left over, then that data shall be in the format of valid boxes with type and size codes, i.e., the unprotected data contains the types and sizes.
+
+If any JPEG 2000 Core coding system mandatory box is encrypted, the "jp2" brand should be removed from the compatible list in file type box.
+
+#### C.3.10.2 Syntax
+
+```
+aligned(8) class JProtectedBox() extends Box('gpprt') {
+    bit(1)    type_flag;
+    bit(1)    size_flag;
+    bit(1)    location_flag;
+    unsigned int(5) reserved; // for ITU-T | ISO use
+    if(size_flag == 1 || type_flag == 1 || location_flag == 1) {
+        unsigned int(32)    entry_count;
+        if(location_flag == 1)
+            unsigned int(8) offset_size;
+        for(i=0; i<entry_count; i++) {
+            if(size_flag == 1)
+                unsigned int(32)    size;
+            if(type_flag == 1)
+                unsigned int(32)    type = boxtype;
+            if(size_flag == 1 && size == 1)
+                unsigned int(64)    large_size;
+            if(location_flag == 1)
+                unsigned int(offset_size*8)    offset;
+        }
+    }
+    else {
+        Unsigned int(32)    total_size;
+        if(total_size == 1)
+            unsigned int(64)    large_total_size;
+    }
+    unsigned int(8) data[];
+}
+```
+
+### C.3.10.3 Semantics
+
+`size_flag` indicates whether or not size value is present. A value of 1 means the size of each entry in Generic Protected Box is present; 0 means the size is not present.
+
+`type_flag` indicates whether or not the box type is present. A value of 1 means the original type of each entry in Generic Protected Box is present; 0 means the type is not present.
+
+`location_flag` indicates whether or not the location is present. A value of 1 means the original location of each entry in Generic Protected Box is present; 0 means the original location is not present.
+
+`entry_count` is the number of entries in the Generic Protected Box.
+
+`offset_size` is the length of the `offset` in bytes.
+
+Each `size` entry is the size of a box that has been replaced by the Generic Protected Box.
+
+Each `type` entry is the original type of a box that has been replaced by the Generic Protected Box.
+
+Each `offset` entry is the offset of a box that has been replaced by the Generic Protected Box.
+
+`total_size` is the total size of the entries in the Generic Protected Box.
+
+`data[]` is an array of bytes to the end of the box that can be referenced by the `ItemLocationBox` and thus protected with a method defined in the `ItemProtectionBox`.
+
+## C.4 Elementary stream and sample definitions
+
+### C.4.1 Overview
+
+This clause defines the structure of an elementary stream (ES).
+
+An elementary stream contains media data, `ByteData` structure, container structure, pointer structure, or any mixture of the above. There are two types of ES: One type is called *self-contained ES*, which does not contain any container, pointer or `ByteData` structure. The format of self-contained ES is not defined in this Recommendation | International Standard, and it can be any media format like Motion JPEG 2000 sequence. The other type is referred to as *composed ES*, where the media data is composed from other elementary streams. A composed ES can either copy data from other tracks or reference data in other tracks. When a media data segment is copied from other tracks, the segment shall be wrapped in `ByteData` structure; the pointer structure is used to reference media data segments in other ESs. When a sample in composed ES consists of more than one structure, a container structure shall be used to wrap all structures belonging to that sample.
+
+The composed ES can be classified into *Scalable Composed ES* and *Decodable Composed ES*. The former is designed to support scalability, i.e., to make the codestream "thinable", the adaptor can make a codestream by combining multiple such ESs. However, it is assumed that the adaptor should be able to generate new headers and modify the index number within each packet. The decodable composed ES is designed for simple adaptor that has no capability to generate headers or modify packet index numbers. The adaptor simply follows the instructions in a decodable composed ES to generate a complete decodable codestream.
+
+Figure C.2 illustrates the relationship between self-contained ES and scalable composed ES. In scalable composed ES, each sample is wrapped by a container structure, where a pointer is referring to the desired data segment(s) in the self-contained ES. Note that a scalable composed ES does not contain any headers, the adapter has to dynamically generate the header to make a codestream that is decodable by normal decoder. In addition, each scalable composed ES might not constitute a complete decodable codestream by itself, and multiple scalable composed ESs can be required to make a complete codestream. For example, in Figure C.2, the adaptor has to combine the scalable composed ES 0 and 1 to make a resolution-1 JPEG 2000 frame.
+
+![Figure C.2: Self-contained ES and scalable composed ES. The diagram shows a 'Self-contained ES (motion JPEG 2000)' with samples 1 through 5. Sample 1 contains 'hdr', 'R0', 'R1', and 'R2'. Below it, 'Scalable composed ES 1 (R0)', 'Scalable composed ES 2 (R1)', and 'Scalable composed ES 3 (R2)' are shown. Dashed arrows indicate that the 'hdr' of the self-contained ES points to the 'hdr' of each scalable composed ES, and the 'R0', 'R1', and 'R2' segments of the self-contained ES point to the corresponding segments in the scalable composed ESs. A 'Pointer Container' is also indicated.](66fb62ebfc68240e7523d7d1ac7f1656_img.jpg)
+
+T.803(23)\_FC.2
+
+Figure C.2: Self-contained ES and scalable composed ES. The diagram shows a 'Self-contained ES (motion JPEG 2000)' with samples 1 through 5. Sample 1 contains 'hdr', 'R0', 'R1', and 'R2'. Below it, 'Scalable composed ES 1 (R0)', 'Scalable composed ES 2 (R1)', and 'Scalable composed ES 3 (R2)' are shown. Dashed arrows indicate that the 'hdr' of the self-contained ES points to the 'hdr' of each scalable composed ES, and the 'R0', 'R1', and 'R2' segments of the self-contained ES point to the corresponding segments in the scalable composed ESs. A 'Pointer Container' is also indicated.
+
+Figure C.2 – Self-contained ES and scalable composed ES
+
+Figure C.3 illustrates the relationship between self-contained ES and decodable composed ESs. In decodable composed ES, a sample is wrapped by a container, which includes the *Data* structure (with header information), and one or more pointer structures referring to data segments in the self-contained ES.
+
+![Figure C.3: Self-contained ES and decodable composed ES. The diagram shows a 'Self-contained ES (motion JPEG 2000)' with samples 1 through 5. Sample 1 contains 'hdr', 'R0', 'R1', and 'R2'. Below it, 'Decodable composed ES 1 (R0)', 'Decodable composed ES 2 (R0R1)', and 'Decodable composed ES 3 (R0R1R2)' are shown. Dashed arrows indicate that the 'hdr' of the self-contained ES points to the 'hdr' of each decodable composed ES, and the 'R0', 'R1', and 'R2' segments of the self-contained ES point to the corresponding segments in the decodable composed ESs. A 'ByteData Pointer Container' is also indicated.](18d7d8de298d79e7bc87af5217f11203_img.jpg)
+
+T.803(23)\_FC.3
+
+Figure C.3: Self-contained ES and decodable composed ES. The diagram shows a 'Self-contained ES (motion JPEG 2000)' with samples 1 through 5. Sample 1 contains 'hdr', 'R0', 'R1', and 'R2'. Below it, 'Decodable composed ES 1 (R0)', 'Decodable composed ES 2 (R0R1)', and 'Decodable composed ES 3 (R0R1R2)' are shown. Dashed arrows indicate that the 'hdr' of the self-contained ES points to the 'hdr' of each decodable composed ES, and the 'R0', 'R1', and 'R2' segments of the self-contained ES point to the corresponding segments in the decodable composed ESs. A 'ByteData Pointer Container' is also indicated.
+
+Figure C.3 – Self-contained ES and decodable composed ES
+
+#### C.4.2 In-stream structures
+
+This clause defines the in-stream structures used in scalable composed ES and decodable composed ES. A composed ES can include media from other elementary streams either by copy or by reference. The *ByteData* structure is used to include media data by copy while the pointer structure is used to include media data by reference. In addition, each sample is wrapped by a container structure, which can contain one or more *ByteData* or pointer structures.
+
+```
+
+class aligned(8) DataUnit(type) {
+    unsigned int(32)    type;
+    unsigned int(32)    size;
+    unsigned int(32)    RDHints;
+}
+
+class ByteData(type='bdat') extends DataUnit() {
+    unsigned int(8) data[];
+}
+
+class Container(type='cont') extends DataUnit() {
+    DataUnit(type) units[];
+}
+
+class Pointer(type='poin') extends DataUnit() {
+
+    unsigned int(8)    rack_ref_index;
+    unsigned int(8) segment_count;
+    for(int i=0; i<segment_count; i++) {
+        unsigned int(32)    offset;
+        unsigned int(32)    length;
+    }
+}
+
+```
+
+Semantics:
+
+`type` indicates the type of the data structure, like "ByteData", "Container" and "Pointer".
+
+`size` is the size of this structure, including itself and subsequent data in this structure.
+
+`RDHints` indicates the relative or absolute importance of media data contained or referenced by this object. For instance, `RDHints` could be an associated distortion increment value, the amount by which the media distortion will increase if the media data is lost, or it could be importance ranking.
+
+`data[]` is a byte array containing media data in its original format. This Recommendation | International Standard does not specify the format of the media data.
+
+`units[]` is a list of objects contained by container object. The object can be either "ByteData" or "Pointer", but cannot be another "Container" object.
+
+`track_ref_index` specifies the index of the track to which this "pointer" is pointing.
+
+`segment_count` is the number of "offset" and "length" pair.
+
+`offset` is the offset of the first byte within the referred sample to copy.
+
+`length` is the number of bytes of the data segment.
+
+## C.5 Protection at file format level
+
+### C.5.1 Overview
+
+C.5.2 to C.5.4 describe how media data is protected using the protection schemes (i.e., authentication or description) and how the protection is signalled using the boxes defined in C.3.4 and C.3.5.
+
+When the security tools applied change the data length, it shall update all pointers and length fields in all boxes, to ensure correct parsing by the reader.
+
+### C.5.2 Item-based protection for ISO base file format and JPEG family file formats
+
+This annex defines two types of **ProtectionSchemeInfoBox**(): authentication and decryption. The two protection schemes protect the scalable media without loss of scalability.
+
+Each instance of a protection scheme and used parameters (like MAC, IV, keys, etc.) are described by a **ProtectionSchemeInfoBox** located inside **ItemProtectionBox**. On the other hand, the **ItemLocationBox** contains a list of items and each item points to one or more contiguous segments of media data. The **ItemInformationBox** maintains a mapping table between the items in **ItemLocationBox** and the protection schemes in **ItemProtectionBox**. Figure C.4 gives an example with two items and three protection schemes: item 0 is protected with Scheme 0 and Scheme 2, while Item 1 is protected with Scheme 1.
+
+As illustrated in Figure C.4, the same item can be applied with multiple protection schemes, e.g., item 0. In addition, the items can overlap with each other, and the overlapped region can be applied with multiple protection schemes. Therefore, it is important to specify the processing order among the protection schemes. The 'ffsc' file format mandates that the file shall be un-protected in the same order as the schemes appear in 'iinf' box. For instance, for un-protection, the first scheme appearing in 'iinf' box is applied first and the last scheme appearing in 'iinf' box is applied last. In this example, the file is first un-protected with Scheme 2 on Item 0, followed by Scheme 1 on Item 1 and scheme 0 on Item 0.
+
+NOTE – The protection order (with multiple protection tools) is the reverse of the un-protection order, that is, the first scheme appearing in "iinf" box is the last tool to be applied, and the last scheme appearing in "iinf" box is the first tool to be applied.
+
+![Diagram illustrating the relationship between Item location box (iloc), Item information box (iinf), and Item protection box (ipro).](dfa2632198a25c9c884502cdc0597c6e_img.jpg)
+
+The diagram shows three boxes: 'Item location box (iloc)', 'Item information box (iinf)', and 'Item protection box (ipro)'. The 'iloc' box contains 'Item 0' and 'Item 1'. The 'iinf' box contains 'Item 0, scheme 2', 'Item 1, scheme 1', and 'Item 0, scheme 0'. The 'ipro' box contains 'Scheme 0', 'Scheme 1', and 'Scheme 2'. Arrows indicate the mapping: 'Item 0' in 'iloc' points to 'Item 0, scheme 2' and 'Item 0, scheme 0' in 'iinf'. 'Item 1' in 'iloc' points to 'Item 1, scheme 1' in 'iinf'. 'Item 0, scheme 2' in 'iinf' points to 'Scheme 2' in 'ipro'. 'Item 1, scheme 1' in 'iinf' points to 'Scheme 1' in 'ipro'. 'Item 0, scheme 0' in 'iinf' points to 'Scheme 0' in 'ipro'.
+
+T.807(23)\_FC.4
+
+Diagram illustrating the relationship between Item location box (iloc), Item information box (iinf), and Item protection box (ipro).
+
+Figure C.4 – Relationship between iloc, iinf and ipro
+
+### C.5.3 Additional requirements for item-based protection for JPEG family file formats
+
+JP2, JPX and JPM files are not based on the ISO base file format but have some common boxes, e.g., the File Type Box ('ftyp'). In order to use the Item-based protection in this Recommendation | International Standard, these file formats
+
+shall incorporate protection by adding the 'meta', 'hdlr', 'ipro', 'iloc', and 'iinf' from ISO/IEC 14496-12 in addition to the new boxes defined by this Recommendation | International Standard.
+
+Operation of protection is the same as for the ISO base file format. However, codestreams in JPEG family file formats can appear in contiguous codestream boxes in addition to Media Data ('mdat') boxes.
+
+#### C.5.4 Sample-based protection
+
+When a protection scheme is applied on a sample basis, it is signalled by a ProtectionSchemeInfoBox located in either the ScalableSampleDescriptionEntry or the ScalableSampleGroupEntry. When the ProtectionSchemeInfoBox is located in the ScalableSampleDescriptionEntry, the protection is applied to all samples in the track; when the ProtectionSchemeInfoBox is located in the ScalableSampleGroupEntry, the protection is applied only to the samples in the sample group.
+
+When samples are applied with multiple protection schemes, the ScalableSampleDescriptionEntry or ScalableSampleGroupEntry contains multiple ProtectionSchemeInfoBoxes. Under the major brand of 'ffsc', the samples shall be un-protected in the order that the corresponding ProtectionSchemeInfoBoxes were defined.
+
+Figure C.5 gives an example of "mp4v" sample description entry that is protected with an authentication followed by an encryption. Note that there are two ProtectionSchemeInfoBoxes in this entry: the first one is for the decryption scheme while the second one is for the authentication scheme. To un-protect the sample, the file reader has to apply the decryption scheme followed by the authentication scheme, which is the order in which it appears in the sample entry.
+
+When sample-based protection is applied to composed ES, the protection is actually applied to the media data which is contained or pointed to by the container, ByteData or pointers object. For instance, to encrypt a sample in a composed ES, which is wrapped by a container object, the protection process shall encrypt its media data only, retaining the structure of the container.
+
+The sample-based protection can be applied to all samples in a track or sample group as a whole (when GL = 0 in SchemeInformationBox) or separately to each sample (when GL = 1 in SchemeInformationBox). In the former case, the ValueList has only one MAC or IV, and in the latter case, the ValueList has one MAC or IV for each sample.
+
+![Diagram of a sample description entry (4CC code = encv) showing two ProtectionSchemeInfoBoxes. The first box (ProtectionSchemeInfoBox 1) contains an OriginalFormatBox (data_format = autv), a SchemeTypeBox (scheme_type = decr), and a SchemeInformationBox for decryption scheme. The second box (ProtectionSchemeInfoBox 2) contains an OriginalFormatBox (data_format = mp4v), a SchemeTypeBox (scheme_type = auth), and a SchemeInformationBox for authentication scheme.](f92e919c70b7adda2d0e778889f44fae_img.jpg)
+
+```
+
+graph TD
+    subgraph "Sample description entry (4CC code = encv)"
+        subgraph "ProtectionSchemeInfoBox 1"
+            OF1[OriginalFormatBox (data_format = autv)]
+            ST1[SchemeTypeBox (scheme_type = decr)]
+            SI1[SchemeInformationBox for decryption scheme]
+        end
+        subgraph "ProtectionSchemeInfoBox 2"
+            OF2[OriginalFormatBox (data_format = mp4v)]
+            ST2[SchemeTypeBox (scheme_type = auth)]
+            SI2[SchemeInformationBox for authentication scheme]
+        end
+    end
+  
+```
+
+T.807(23)\_FC.5
+
+Diagram of a sample description entry (4CC code = encv) showing two ProtectionSchemeInfoBoxes. The first box (ProtectionSchemeInfoBox 1) contains an OriginalFormatBox (data\_format = autv), a SchemeTypeBox (scheme\_type = decr), and a SchemeInformationBox for decryption scheme. The second box (ProtectionSchemeInfoBox 2) contains an OriginalFormatBox (data\_format = mp4v), a SchemeTypeBox (scheme\_type = auth), and a SchemeInformationBox for authentication scheme.
+
+**Figure C.5 – An example sample description entry protected by authentication scheme followed by decryption scheme**
+
+## C.6 Examples (Informative)
+
+### C.6.1 Example 1
+
+This example shows a very simple JPEG file (using JP2 file format) using only authentication. As shown in Figure C.6, authentication is applied to the coded media data stored in the "Contiguous codestream box", authentication algorithm is HMAC with SHA-1 hashing.
+
+![Diagram of JP2 file structure showing nested boxes for authentication.](856f6b5a43a3ca2bf49b8446412dc6ae_img.jpg)
+
+The diagram illustrates the structure of a JP2 file for item-based protection with authentication. It is organized as follows:
+
+- JP2 file** (outermost container)
+  - JPEG 2000 signature box
+  - File Type box (BR = 'jp2\040'; CL = 'fsc')
+  - JP2 Header box
+    - Image Header box
+    - Bits Per Component box
+    - Colour Specification box
+  - Contiguous codestream box (byte range: 0×0100, ..., 0×34567)
+  - Meta box
+    - Item Location box (Item 1: 0×100, ..., 0×34567) // pointing to contiguous codestream box
+    - Item Protection box
+      - ProtectionSchemeInfoBox1
+        - AuthenticationSchemeInfoBox (Algo = HMAC with SHA-1; Key = k0)
+    - Item Information box (Entry 1: item\_ID = item 1; scheme\_ID = scheme 1)
+
+T.807(23)\_FC.6
+
+Diagram of JP2 file structure showing nested boxes for authentication.
+
+Figure C.6 – Example 1: Item-based protection of JP2 file (authentication)
+
+C.6.2 Example 2
+
+This example corresponds to the example given in 6.3.1. An image is coded with JPEG 2000 and has three resolutions. The first resolution is not encrypted in order to provide preview capability, and the second and third resolutions are encrypted with keys k1 and k2, respectively. The input image is coded in RLCP progression order and has 1 tile and 3 resolutions. (The number of layers, components and precincts are not important in this specific example.) Encryption is performed using AES in CBC mode without padding (using cipher-text stealing), using k1 to encrypt resolution 1 and using k2 to encrypt resolution 2, and resolution 0 is left unencrypted.
+
+First of all, the ItemLocationBox contains two Items: one item points to the byte range from 0x31CC to 0xA3E8 and the other one points to the byte range from 0xA3E9 to 0x31101. The ItemProtectionBox contains two DecryptionSchemeInformationBoxes: the first one uses AES in CBC mode and k1, the other uses AES in CBC mode and k2. The ItemInformationBox links the DecryptionSchemeInformationBoxes in ItemProtectionBox to the Items in ItemLocationBox. In ItemDescriptionBox, ItemDescription 1 describes Item 1 as resolution 1 of the image, while ItemDescription 2 describes Item 2 as resolution 2 of the image.
+
+Note that JPEG 2000 image can be located in either MDAT box in the sample file as the META box, or in a different file whose format is described by the ISO base file format, as shown in Figure C.7.
+
+![Figure C.7: Example 2: Item-based protection of a JPEG 2000 images (encryption). The diagram shows a META box containing an ItemLocationBox, an ItemInformationBox, an ItemDescriptionBox, and an ItemProtectionBox. The ItemLocationBox contains Item 1 (byte_range = 0x31CC ... 0xA3E8) and Item 2 (byte_range = 0xA3E9 ... 0x31101). The ItemInformationBox contains ItemInfoBox 1 and ItemInfoBox 2. The ItemDescriptionBox contains ItemDescription 1 Res 1 and ItemDescription 2 Res 2. The ItemProtectionBox contains ProtectionSchemeInfoBox 1 (DecryptionSchemeInformationBox (AES CBC mode; key: k1)) and ProtectionSchemeInfoBox 2 (DecryptionSchemeInformationBox (AES CBC mode; key: k2)). Arrows indicate relationships: ItemInfoBox 1 points to Item 1 and Item 2; ItemInfoBox 2 points to Item 2; ItemDescription 1 Res 1 points to Item 1; ItemDescription 2 Res 2 points to Item 2; ProtectionSchemeInfoBox 1 points to Item 1; ProtectionSchemeInfoBox 2 points to Item 2. Below the META box is an MDAT box or external file containing Res 0 (0x0000 ... 0x31CB), Res 1 (0x31CC ... 0xA3E8), and Res 2 (0xA3E9 ... 0x31101).](dae88eec6d1005984029b794ff8b7a9e_img.jpg)
+
+T.807(23)\_FC.7
+
+Figure C.7: Example 2: Item-based protection of a JPEG 2000 images (encryption). The diagram shows a META box containing an ItemLocationBox, an ItemInformationBox, an ItemDescriptionBox, and an ItemProtectionBox. The ItemLocationBox contains Item 1 (byte\_range = 0x31CC ... 0xA3E8) and Item 2 (byte\_range = 0xA3E9 ... 0x31101). The ItemInformationBox contains ItemInfoBox 1 and ItemInfoBox 2. The ItemDescriptionBox contains ItemDescription 1 Res 1 and ItemDescription 2 Res 2. The ItemProtectionBox contains ProtectionSchemeInfoBox 1 (DecryptionSchemeInformationBox (AES CBC mode; key: k1)) and ProtectionSchemeInfoBox 2 (DecryptionSchemeInformationBox (AES CBC mode; key: k2)). Arrows indicate relationships: ItemInfoBox 1 points to Item 1 and Item 2; ItemInfoBox 2 points to Item 2; ItemDescription 1 Res 1 points to Item 1; ItemDescription 2 Res 2 points to Item 2; ProtectionSchemeInfoBox 1 points to Item 1; ProtectionSchemeInfoBox 2 points to Item 2. Below the META box is an MDAT box or external file containing Res 0 (0x0000 ... 0x31CB), Res 1 (0x31CC ... 0xA3E8), and Res 2 (0xA3E9 ... 0x31101).
+
+Figure C.7 – Example 2: Item-based protection of a JPEG 2000 images (encryption)
+
+### C.6.2.1 Transcoding to resolution 1
+
+To securely transcode the above example to lower resolution by discarding resolution 2, the transcoder needs to do the following:
+
+- Discard the trunk of media data corresponding to resolution 2, i.e., byte range 0xA3E9 – 0x31101.
+- Remove Item 2 from ItemLocationBox.
+- Remove ItemInfoBox 2 from ItemInformationBox.
+- Remove ItemDescription 2 from ItemDescriptionBox.
+- Remove ProtectionSchemeInfoBox 2 from ItemProtectionBox.
+
+After transcoding, the resulting File format is shown in Figure C.8. Note that the transcoder does not have to decrypt the media data, and thereby achieve end-to-end security.
+
+![Figure C.8: Example 2: Secure transcoding to lower resolution (discarding resolution 2). The diagram shows a META box containing an ItemLocationBox, an ItemInformationBox, an ItemDescriptionBox, and an ItemProtectionBox. The ItemLocationBox contains Item 1 (byte_range = 0x31CC ... 0xA3E8). The ItemInformationBox contains ItemInfoBox 1. The ItemDescriptionBox contains ItemDescription 1 Res 1. The ItemProtectionBox contains ProtectionSchemeInfoBox 1 (DecryptionSchemeInformationBox (AES CBC mode; Key: k1)). Arrows indicate relationships: ItemInfoBox 1 points to Item 1; ItemDescription 1 Res 1 points to Item 1; ProtectionSchemeInfoBox 1 points to Item 1. Below the META box is an MDAT box or external file containing Res 0 (0x0000 ... 0x31CB) and Res 1 (0x31CC ... 0xA3E8).](c020c072c67473d7823d1f9551942732_img.jpg)
+
+T.807(23)\_FC.8
+
+Figure C.8: Example 2: Secure transcoding to lower resolution (discarding resolution 2). The diagram shows a META box containing an ItemLocationBox, an ItemInformationBox, an ItemDescriptionBox, and an ItemProtectionBox. The ItemLocationBox contains Item 1 (byte\_range = 0x31CC ... 0xA3E8). The ItemInformationBox contains ItemInfoBox 1. The ItemDescriptionBox contains ItemDescription 1 Res 1. The ItemProtectionBox contains ProtectionSchemeInfoBox 1 (DecryptionSchemeInformationBox (AES CBC mode; Key: k1)). Arrows indicate relationships: ItemInfoBox 1 points to Item 1; ItemDescription 1 Res 1 points to Item 1; ProtectionSchemeInfoBox 1 points to Item 1. Below the META box is an MDAT box or external file containing Res 0 (0x0000 ... 0x31CB) and Res 1 (0x31CC ... 0xA3E8).
+
+Figure C.8 – Example 2: Secure transcoding to lower resolution (discarding resolution 2)
+
+### C.6.3 Example 3
+
+This example corresponds to the example given in 6.3.2. In this case, authentication is applied to the same JPEG 2000 coded image as in Example 1. In this example all three resolutions are authenticated, where the authentication for each resolution uses a different key. Each resolution is authenticated using different keys, and each layer within a resolution has its own MAC value. In summary, there will be a total of three keys and nine MAC values for the entire image. Specifically
+
+- Resolution 0 has three MAC values M0, M1 and M2 (one for each layer) using K0
+- Resolution 1 has three MAC values M3, M4 and M5 (one for each layer) using K1
+
+- Resolution 2 has three MAC values M6, M7 and M8 (one for each layer) using K2
+
+The authentication is performed using HMAC with SHA-1 hash. As shown in Figure C.9, the ItemLocationBox has three items corresponding to three resolutions, and each item has three extents corresponding to three layers within a resolution. The ItemProtectionBox contains three ProtectionSchemeInformationBoxes, the first one signals the applied authentication tool using K0 and three MAC values M0, M1 and M2, and so forth. The ItemInformationBox and ItemDescriptionBox are used in the same way as the previous example.
+
+Note that "granularity" field in the AuthenticationSchemeInformationBox is used to indicate the smaller protection unit of the authentication tool. When "granularity" is "extent", the authentication tool will generate one MAC for each extent (i.e., three MAC values for the entire Item in this example); when it is set to "item", it will generate only one MAC value for the entire item.
+
+![Figure C.9: Example 3: Item-based protection of a JPEG 2000 image (Authentication). The diagram shows a META box containing ItemLocationBox, ItemInformationBox, and ItemProtectionBox. ItemLocationBox lists three items with their extents. ItemInformationBox and ItemDescriptionBox contain information for each item. ItemProtectionBox contains three ProtectionSchemeInformationBoxes for each item, each with a decryption scheme and MAC values. Below the META box is an MDAT box or external file table.](145fb9b19dc6513e7bf84c9ba7f083f2_img.jpg)
+
+| MDAT box or external file  |                            |                            |
+|----------------------------|----------------------------|----------------------------|
+| R0L0 (0x00000 ... 0x01000) | R0L1 (0x01001 ... 0x02000) | R0L2 (0x02001 ... 0x031CB) |
+| R1L0 (0x031CC ... 0x061CC) | R1L1 (0x061CD ... 0x091CC) | R1L2 (0x091CD ... 0x0A3E8) |
+| R2L0 (0x0A3E9 ... 0x10000) | R2L1 (0x10001 ... 0x20000) | R2L2 (0x20001 ... 0x31101) |
+
+Figure C.9: Example 3: Item-based protection of a JPEG 2000 image (Authentication). The diagram shows a META box containing ItemLocationBox, ItemInformationBox, and ItemProtectionBox. ItemLocationBox lists three items with their extents. ItemInformationBox and ItemDescriptionBox contain information for each item. ItemProtectionBox contains three ProtectionSchemeInformationBoxes for each item, each with a decryption scheme and MAC values. Below the META box is an MDAT box or external file table.
+
+T.807(23)\_FC.9
+
+Figure C.9 – Example 3: Item-based protection of a JPEG 2000 image (Authentication)
+
+C.6.3.1 Transcoding to resolution 1
+
+To securely transcode the above example to resolution 1, the transcoding has to do the following:
+
+Discard trunk of media data corresponding to resolution 1, i.e., byte range 0xA3E9 – 0x31101.
+
+- Remove Item 3 from ItemLocationBox
+- Remove ItemInfoBox 3 from ItemInformationBox
+- Remove ItemDescription 3 from ItemDescriptionBox
+- Remove ProtectionSchemeInfoBox 3 from ItemProtectionBox
+
+The resulting file format of the transcoded codestream is shown in Figure C.10.
+
+![Figure C.10: Example 3: Transcoding to resolution 1. The diagram shows a META box containing ItemLocationBox, ItemInformationBox, and ItemProtectionBox. ItemLocationBox lists Item 1 and Item 2 with their extents. ItemInformationBox contains ItemInfoBox 1 and ItemInfoBox 2. ItemDescriptionBox contains ItemDescription 0 Res 0 and ItemDescription 1 Res 1. ItemProtectionBox contains ProtectionSchemeInfoBox 1 and ProtectionSchemeInfoBox 2, each with a DecryptionSchemeInformationBox. Arrows show mappings from Item 1 to ItemInfoBox 1, ItemInfoBox 2, and ProtectionSchemeInfoBox 1. Item 2 maps to ItemInfoBox 2, ItemDescription 0, ItemDescription 1, and ProtectionSchemeInfoBox 2. Below the META box is an MDAT box or external file table with rows R0L0, R0L1, R0L2, R1L0, R1L1, and R1L2.](90183a52275501da5a0fd5c63d837009_img.jpg)
+
+| MDAT box or external file  |                            |                            |
+|----------------------------|----------------------------|----------------------------|
+| R0L0 (0×00000 ... 0×01000) | R0L1 (0×01001 ... 0×02000) | R0L2 (0×02001 ... 0×031CB) |
+| R1L0 (0×031CC ... 0×061CC) | R1L1 (0×061CD ... 0×091CC) | R1L2 (0×091CD ... 0×0A3E8) |
+
+Figure C.10: Example 3: Transcoding to resolution 1. The diagram shows a META box containing ItemLocationBox, ItemInformationBox, and ItemProtectionBox. ItemLocationBox lists Item 1 and Item 2 with their extents. ItemInformationBox contains ItemInfoBox 1 and ItemInfoBox 2. ItemDescriptionBox contains ItemDescription 0 Res 0 and ItemDescription 1 Res 1. ItemProtectionBox contains ProtectionSchemeInfoBox 1 and ProtectionSchemeInfoBox 2, each with a DecryptionSchemeInformationBox. Arrows show mappings from Item 1 to ItemInfoBox 1, ItemInfoBox 2, and ProtectionSchemeInfoBox 1. Item 2 maps to ItemInfoBox 2, ItemDescription 0, ItemDescription 1, and ProtectionSchemeInfoBox 2. Below the META box is an MDAT box or external file table with rows R0L0, R0L1, R0L2, R1L0, R1L1, and R1L2.
+
+T.807(23)\_FC.10
+
+Figure C.10 – Example 3: Transcoding to resolution 1
+
+C.6.4 Example 4
+
+This example illustrates sample-based protection for a time-sequenced JPEG 2000 coded pictures. Each picture has three layers (L0, L1 and L2), and all three layers are authenticated using a unique key (AK0, AK1 and AK2). After that, the L1 and L2 are encrypted using a unique key (CK0 and CK1). That is, L0 is authenticated with AK0 producing one MAC value M0. L1 and L2 are first authenticated with AK1 and AK2 (producing M1 and M2) and then encrypted using CK0 and CK1 respectively. Authentication is applied using HMAC with SHA-1 and encryption is achieved using AES in CBC mode.
+
+To preserve scalability at the file format level, three scalable composed ESs are generated, ES0, ES1, and ES2, one for each layer. Each ES is described by one media track, for instance, ES0 is described by Trak0, ES1 is described by Trak1, and so on.
+
+The format of the three tracks (Trak 0, Trak 1 and Trak 2) is illustrated in Figure C.11. Trak 0 has one ProtectionSchemeInfoBox as L0 is protected by authentication tool only. Trak 1 and Trak 2 have two ProtectionSchemeInfoBox as L1 and L2 are protected by both authentication and encryption tool. Note that the decryption tool appears in the first ProtectionSchemeInfoBox and the authentication tool appears in the second ProtectionSchemeInfoBox. The un-protection process has to follow the same order to get decodable JPEG 2000 codestream.
+
+Note that for decodable composed ES and self-contained ES, sample-based protection is applied in the same way as for scalable composed ES.
+
+![Diagram of MOOV Box structure for three tracks (Trak 0, Trak 1, Trak 2) showing sample-based protection hierarchy.](66bf96eec8f739d5e7c9957a178e34e2_img.jpg)
+
+MOOV Box
+
+Trak 0
+
+... :
+
+SampleDescriptionEntry (4CC code = encv)
+
+ProtectionSchemeInfoBox1
+
+|                                                                                     |
+|-------------------------------------------------------------------------------------|
+| OriginalFormatBox (data_format = SCAL)                                              |
+| SchemeTypeBox (scheme_type = auth)                                                  |
+| SchemeInformationBox for Auth (Algo = HMAC with SHA-1; Key = AK0; ValueList = {M0}) |
+
+Trak 1
+
+... :
+
+SampleDescriptionEntry (4CC code = encv)
+
+ProtectionSchemeInfoBox1
+
+|                                                                   |
+|-------------------------------------------------------------------|
+| OriginalFormatBox (data_format = SCAL)                            |
+| SchemeTypeBox (scheme_type = decr)                                |
+| SchemeInformationBox for Auth (Algo = AES in CBC mode; Key = CK0) |
+
+ProtectionSchemeInfoBox2
+
+|                                                                                     |
+|-------------------------------------------------------------------------------------|
+| OriginalFormatBox (data_format = SCAL)                                              |
+| SchemeTypeBox (scheme_type = auth)                                                  |
+| SchemeInformationBox for Auth (Algo = HMAC with SHA-1; Key = AK1; ValueList = {M1}) |
+
+Trak 2
+
+... :
+
+SampleDescriptionEntry (4CC code = encv)
+
+ProtectionSchemeInfoBox1
+
+|                                                                   |
+|-------------------------------------------------------------------|
+| OriginalFormatBox (data_format = SCAL)                            |
+| SchemeTypeBox (scheme_type = decr)                                |
+| SchemeInformationBox for Auth (Algo = AES in CBC mode; Key = CK1) |
+
+ProtectionSchemeInfoBox2
+
+|                                                                                     |
+|-------------------------------------------------------------------------------------|
+| OriginalFormatBox (data_format = SCAL)                                              |
+| SchemeTypeBox (scheme_type = auth)                                                  |
+| SchemeInformationBox for Auth (Algo = HMAC with SHA-1; Key = AK2; ValueList = {M2}) |
+
+Diagram of MOOV Box structure for three tracks (Trak 0, Trak 1, Trak 2) showing sample-based protection hierarchy.
+
+T.807(23)\_FC.11
+
+**Figure C.11 – Example 4: Sample-based protection of a time-sequenced JPEG 2000 pictures**
+
+**C.6.4.1 Transcoding to layer 1**
+
+To securely transcode the sequence of JPEG 2000 picture to layer 1, the transcoder needs to do the following:
+
+- Discard the scalable composed ES 2 corresponding to layer 2, and discard the trunk of media data in self-contained ES.
+- If necessary, the transcoder also needs to update the byte range values of Pointer objects in the remaining two scalable composed ESs.
+
+- Discard Trak 2 that describes scalable composed ES 2.
+
+The resulting file format is shown in Figure C.12.
+
+![Diagram of the MOOV Box structure for Example 4. The MOOV Box contains Trak 0 and Trak 1. Trak 0 contains a SampleDescriptionEntry (4CC code = encv) and a ProtectionSchemeInfoBox1. ProtectionSchemeInfoBox1 contains an OriginalFormatBox (data_format = SCAL), a SchemeTypeBox (scheme_type = auth), and a SchemeInformationBox for Auth (Algo = HMAC with SHA-1; Key = AK0; ValueList = {M0}). Trak 1 contains a SampleDescriptionEntry (4CC code = encv) and two ProtectionSchemeInfoBoxes. ProtectionSchemeInfoBox1 contains an OriginalFormatBox (data_format = SCAL), a SchemeTypeBox (scheme_type = decr), and a SchemeInformationBox for Auth (Algo = AES in CBC mode; Key = CK0). ProtectionSchemeInfoBox2 contains an OriginalFormatBox (data_format = SCAL), a SchemeTypeBox (scheme_type = auth), and a SchemeInformationBox for Auth (Algo = HMAC with SHA-1; Key = AK1; ValueList = {M1}).](11f18bf0233d812ad2604f88f3385d60_img.jpg)
+
+The diagram illustrates the structure of a MOOV Box. It contains two tracks, Trak 0 and Trak 1. Each track contains a SampleDescriptionEntry (4CC code = encv) and a ProtectionSchemeInfoBox. The ProtectionSchemeInfoBox1 in Trak 0 contains an OriginalFormatBox (data\_format = SCAL), a SchemeTypeBox (scheme\_type = auth), and a SchemeInformationBox for Auth (Algo = HMAC with SHA-1; Key = AK0; ValueList = {M0}). The ProtectionSchemeInfoBox1 in Trak 1 contains an OriginalFormatBox (data\_format = SCAL), a SchemeTypeBox (scheme\_type = decr), and a SchemeInformationBox for Auth (Algo = AES in CBC mode; Key = CK0). The ProtectionSchemeInfoBox2 in Trak 1 contains an OriginalFormatBox (data\_format = SCAL), a SchemeTypeBox (scheme\_type = auth), and a SchemeInformationBox for Auth (Algo = HMAC with SHA-1; Key = AK1; ValueList = {M1}).
+
+Diagram of the MOOV Box structure for Example 4. The MOOV Box contains Trak 0 and Trak 1. Trak 0 contains a SampleDescriptionEntry (4CC code = encv) and a ProtectionSchemeInfoBox1. ProtectionSchemeInfoBox1 contains an OriginalFormatBox (data\_format = SCAL), a SchemeTypeBox (scheme\_type = auth), and a SchemeInformationBox for Auth (Algo = HMAC with SHA-1; Key = AK0; ValueList = {M0}). Trak 1 contains a SampleDescriptionEntry (4CC code = encv) and two ProtectionSchemeInfoBoxes. ProtectionSchemeInfoBox1 contains an OriginalFormatBox (data\_format = SCAL), a SchemeTypeBox (scheme\_type = decr), and a SchemeInformationBox for Auth (Algo = AES in CBC mode; Key = CK0). ProtectionSchemeInfoBox2 contains an OriginalFormatBox (data\_format = SCAL), a SchemeTypeBox (scheme\_type = auth), and a SchemeInformationBox for Auth (Algo = HMAC with SHA-1; Key = AK1; ValueList = {M1}).
+
+T.807(23)\_FC.12
+
+Figure C.12 – Example 4: Secure transcoding to lower SNR quality (layer 1)
+
+### C.6.5 Example 5
+
+This example illustrates how sample-based protection is applied for video browsing and video summarization. In this example, a sequence of 10000 frames is summarized into 10 scenes. For instance, the first 1000 frames constitute the first scene; the second 1000 frames constitute the second scene, and so on. For each scene, the first 50 frames (5-second video at 10 fps) are left unencrypted for preview purposes, the rest of the frames are encrypted using AES in CBC mode with key K0. In this example, the 10000 pictures are stored in a self-contained ES, which can be located in MDAT box or external file whose format is not specified by the ISO base file format.
+
+Figure C.13 illustrates the file format when the above protection is applied to a self-contained ES, which is described by Track 0. The SampleToGroupBox has 20 entries, the first 50 pictures of every scene are mapped to no descriptor and the next 950 pictures of each scene are mapped to the first ScalableSampleGroupEntry in SampleGroupDescriptionBox. The grouping\_type is "prot", for protection purposes.
+
+The ScalableSampleGroupEntry has handler\_type of "encv" and the protection is applied to all resolutions (res = -1), all layers (layer = -1) and all regions of each sample (cropped\_width=cropped\_height=0). As only one protection is applied to this sample group, the ScalableSampleGroupEntry contains only one ProtectionSchemeInfoBox, which in turn contains the OriginalFormatBox, the SchemeTypeBox and the SchemeInformationBox.
+
+![Diagram of MOOV Box structure for sample-based protection.](b76d1b06cf06e1c28f844e68507b40ed_img.jpg)
+
+The diagram illustrates the structure of a MOOV Box. It contains a Trak 0 box, which in turn contains a SampleToGroupBox (grouping\_type = prot; entry\_count = 20). This group box lists 20 entries, with the first three and last two explicitly shown: Entry 1 (sample\_count = 50, group\_description\_index = 0), Entry 2 (sample\_count = 950, group\_description\_index = 1), Entry 3 (sample\_count = 50, group\_description\_index = 0), and Entry 20 (sample\_count = 950, group\_description\_index = 1). Below the SampleToGroupBox is a SampleGroupDescriptionBox (grouping\_type = prot; entry\_count = 1), which contains a SampleGroupDescriptionEntry 1. This entry contains a ProtectionSchemeInfoBox, which includes an OriginalFormatBox (data\_format = j2k), a SchemeTypeBox (scheme\_type = decr), and a SchemeInformationBox for Auth (Algo = AES in CBC mode; Key = K0).
+
+T.807(23)\_FC.13
+
+Diagram of MOOV Box structure for sample-based protection.
+
+Figure C.13 – Example 5: Sample-based protection for video browsing or video summarization
+
+C.6.5.1 Example 5: Transcoding to shorter time length
+
+This example illustrates how to securely transcode the above codestream to shorter the time length, i.e., discarding the last 5000 pictures. The transcoder has to do the following things:
+
+- Discard the trunk of media data corresponding to the last 5000 pictures.
+- Remove the entries corresponding to the last 5000 pictures in SampleToGroupBox.
+
+The resulting codestream is shown in Figure C.14.
+
+![Diagram of MOOV Box structure after transcoding to shorter time length.](0e252770f8f0573617e0112b36a93d2f_img.jpg)
+
+The diagram illustrates the structure of a MOOV Box after transcoding. It contains a Trak 0 box, which contains a SampleToGroupBox (grouping\_type = prot; entry\_count = 20). The entries are now: Entry 1 (sample\_count = 50, group\_description\_index = 0), Entry 2 (sample\_count = 950, group\_description\_index = 1), Entry 3 (sample\_count = 50, group\_description\_index = 0), Entry 4 (sample\_count = 950, group\_description\_index = 1), and Entry 20 (sample\_count = 950, group\_description\_index = 1). Below the SampleToGroupBox is a SampleGroupDescriptionBox (grouping\_type = prot; entry\_count = 1), which contains a SampleGroupDescriptionEntry 1. This entry contains a ProtectionSchemeInfoBox, which includes an OriginalFormatBox (data\_format = j2k), a SchemeTypeBox (scheme\_type = decr), and a SchemeInformationBox for Auth (Algo = AES in CBC mode; Key = K0).
+
+T.807(23)\_FC.14
+
+Diagram of MOOV Box structure after transcoding to shorter time length.
+
+Figure C.14 – Example 5: Transcoding to shorter time length (discarding the last 5000 pictures)
+
+### C.6.6 Example 6
+
+This example demonstrates how the structures defined in this annex can be used to perform authentication and decoding of verified data, as shown in Figure C.15.
+
+An authentication adaptor/transcoder removes data that is not verifiable with the available media data and authentication data. For example, in a streaming system, some media packets can be lost during transmission. A file format receiver can reconstruct the received data to the best of its ability based on the available data. Then, an authentication adaptor/transcoder can determine which data can be verified, and then remove the packets that are not verifiable. The resulting file only contains the decodable, verified data.
+
+![Figure C.15: Authentication transcoding process. It shows a sequence of 'Received media packets' (grey and red) being processed by an 'Authentication transcoder' to produce 'Transcoded media packets' (white, red, and blue). A legend below explains the colors: grey for 'Received packet', white for 'Received and verified packet', red for 'Lost packet', and blue for 'Received and unverified packet'. The diagram is labeled T.807(23)_FC.15.](886963464425186f4a465fa8155d2a3c_img.jpg)
+
+Received media packets
+
+Authentication transcoder
+
+Transcoded media packets
+
+Received packet
+
+Received and verified packet
+
+Lost packet
+
+Received and unverified packet
+
+T.807(23)\_FC.15
+
+Figure C.15: Authentication transcoding process. It shows a sequence of 'Received media packets' (grey and red) being processed by an 'Authentication transcoder' to produce 'Transcoded media packets' (white, red, and blue). A legend below explains the colors: grey for 'Received packet', white for 'Received and verified packet', red for 'Lost packet', and blue for 'Received and unverified packet'. The diagram is labeled T.807(23)\_FC.15.
+
+Figure C.15 – Example 6: Authentication transcoding, discarding received but unverifiable packets
+
+### C.6.7 Example 7
+
+This example shows the effect of length changes on the contents of a file due to protection coding.
+
+The 'moov' box expanded in Figure C.16 contains boxes that reference samples in the 'mdat' box. In this case the 'mdat' box contains six samples, labelled ED1 to ED6.
+
+![Figure C.16: Motion JPEG 2000 file with detailed box structure. The top part shows a sequence of boxes: jP, ftyp, jp2h, jp2c, meta, xml, mdat, ED1, ED2, ED3, ED4, ED5, ED6, moov, and xml. The 'moov' box is expanded to show its internal structure, including Movie box, Movie Header box, Track box (0), Track box (t-1), Track Header box, Media box, Media Header box, Handler Reference box, Media Information box, Media Header box, Data Information box, Data Reference box, Sample Table box, Sample Description box, Time to Sample box, Sample to Chunk box, Sample Size box, Chunk Offset box, User Data box, Movie Extends box, and Track Extends box (0) to Track Extends box (te-1). The diagram is labeled T.807(23)_FC.16.](9fc0c37f0024c76bce2fb5115a7f2c50_img.jpg)
+
+jP ftyp jp2h jp2c meta xml mdat ED1 ED2 ED3 ED4 ED5 ED6 moov xml
+
+Movie box
+
+Movie Header box
+
+Track box (0) Track box (t-1)
+
+Track Header box
+
+Media box
+
+Media Header box
+
+Handler Reference box
+
+Media Information box
+
+Media Header box
+
+Data Information box
+
+Data Reference box
+
+Sample Table box
+
+Sample Description box
+
+Time to Sample box
+
+Sample to Chunk box
+
+Sample Size box
+
+Chunk Offset box
+
+User Data box
+
+Movie Extends box
+
+Track Extends box (0) Track Extends box (te-1)
+
+T.807(23)\_FC.16
+
+Figure C.16: Motion JPEG 2000 file with detailed box structure. The top part shows a sequence of boxes: jP, ftyp, jp2h, jp2c, meta, xml, mdat, ED1, ED2, ED3, ED4, ED5, ED6, moov, and xml. The 'moov' box is expanded to show its internal structure, including Movie box, Movie Header box, Track box (0), Track box (t-1), Track Header box, Media box, Media Header box, Handler Reference box, Media Information box, Media Header box, Data Information box, Data Reference box, Sample Table box, Sample Description box, Time to Sample box, Sample to Chunk box, Sample Size box, Chunk Offset box, User Data box, Movie Extends box, and Track Extends box (0) to Track Extends box (te-1). The diagram is labeled T.807(23)\_FC.16.
+
+Figure C.16 – Motion JPEG 2000 file with detailed box structure
+
+Without any protection, some of the boxes and the references to those boxes appear as shown in Figure C.17.
+
+![Figure C.17: Simplified Motion JPEG 2000 box structure showing references. The diagram shows a sequence of boxes: jP, ftyp, jp2h, jp2c, meta, xml, mdat, ED1, ED2, ED3, ED4, ED5, ED6, moov, and another xml. Arrows indicate references: from moov to ED1-ED6, from ED1-ED6 to the final xml, and from the final xml back to moov. The label T.807(23)_FC.17 is at the bottom right.](487c58c79e44e6cf98b6368b6667b9c6_img.jpg)
+
+T.807(23)\_FC.17
+
+Figure C.17: Simplified Motion JPEG 2000 box structure showing references. The diagram shows a sequence of boxes: jP, ftyp, jp2h, jp2c, meta, xml, mdat, ED1, ED2, ED3, ED4, ED5, ED6, moov, and another xml. Arrows indicate references: from moov to ED1-ED6, from ED1-ED6 to the final xml, and from the final xml back to moov. The label T.807(23)\_FC.17 is at the bottom right.
+
+Figure C.17 – Simplified Motion JPEG 2000 box structure showing references
+
+Figure C.18 shows boxes or samples in pink that have been protected and can have had their length changed. The pointers in the 'moov' box have been adjusted to point to the correct location of the protected samples.
+
+NOTE – In order to function as shown in those figures, the protection tool understands all pointers present in the file. Thus, a protected Motion JPEG 2000 file requires a protection tool capable of adjusting Motion JPEG 2000 references. The alternative is for the file with portions that have been changed to be marked as unreadable by a Motion JPEG 2000 reader until all length changing operations have been undone.
+
+![Figure C.18: Simplified Motion JPEG 2000 box structure showing references after length changing protection operations. The diagram is similar to Figure C.17, but the boxes 'Ciphred xml' (twice) and the 'moov' box are highlighted in pink. Arrows indicate references: from moov to ED1-ED6, from ED1-ED6 to the final Ciphred xml, and from the final Ciphred xml back to moov. The label T.807(23)_FC.18 is at the bottom right.](97b3ed12d7f6c65cf3f7187326728409_img.jpg)
+
+T.807(23)\_FC.18
+
+Figure C.18: Simplified Motion JPEG 2000 box structure showing references after length changing protection operations. The diagram is similar to Figure C.17, but the boxes 'Ciphred xml' (twice) and the 'moov' box are highlighted in pink. Arrows indicate references: from moov to ED1-ED6, from ED1-ED6 to the final Ciphred xml, and from the final Ciphred xml back to moov. The label T.807(23)\_FC.18 is at the bottom right.
+
+Figure C.18 – Simplified Motion JPEG 2000 box structure showing references after length changing protection operations
+
+C.6.8 Example 8
+
+These examples in Figures C.19, C.20 and C.21 show the effect of length changes on the contents of a JPM file due to protection coding.
+
+![Figure C.19: JPM file with detailed box structure. The diagram shows a sequence of boxes: jP, ftyp, jp2h, jp2c, meta, mhdr, pcol, page, xml, jp2c, jp2c, jp2c, page, xml, jp2c, jp2c, jp2c. A detailed view of the 'page' box is shown, containing: Page box, Page Header box, Primary Page Collection Locator box, Resolution box (with Capture Resolution box and Default Display Resolution box), Base Color box (with Base Color Value box), Color Specification box (0) and (n-1), Bits Per Component box, Layout Object box (0) and (k-1) (with Layout Object Header box, Metadata box, and Object box (0) and (1)), and Object Header box (with Base Color box, Object Scale box, and JP2 Header box).](a7c4533d526366db3c7f9d57de31c314_img.jpg)
+
+T.807(23)\_FC.19
+
+Figure C.19: JPM file with detailed box structure. The diagram shows a sequence of boxes: jP, ftyp, jp2h, jp2c, meta, mhdr, pcol, page, xml, jp2c, jp2c, jp2c, page, xml, jp2c, jp2c, jp2c. A detailed view of the 'page' box is shown, containing: Page box, Page Header box, Primary Page Collection Locator box, Resolution box (with Capture Resolution box and Default Display Resolution box), Base Color box (with Base Color Value box), Color Specification box (0) and (n-1), Bits Per Component box, Layout Object box (0) and (k-1) (with Layout Object Header box, Metadata box, and Object box (0) and (1)), and Object Header box (with Base Color box, Object Scale box, and JP2 Header box).
+
+Figure C.19 – JPM file with detailed box structure
+
+![Figure C.20: Simplified JPM box structure showing references. The diagram shows a sequence of boxes: jP, ftyp, jp2h, jp2c, meta, mhdr, pcol, page, xml, jp2c, jp2c, jp2c, page, xml, jp2c, jp2c, jp2c. Arrows indicate references from the 'page' boxes to the 'xml' and 'jp2c' boxes that follow them.](0dfdff10c725fe9c332b07ade9d23a5e_img.jpg)
+
+T.807(23)\_FC.20
+
+Figure C.20: Simplified JPM box structure showing references. The diagram shows a sequence of boxes: jP, ftyp, jp2h, jp2c, meta, mhdr, pcol, page, xml, jp2c, jp2c, jp2c, page, xml, jp2c, jp2c, jp2c. Arrows indicate references from the 'page' boxes to the 'xml' and 'jp2c' boxes that follow them.
+
+Figure C.20 – Simplified JPM box structure showing references
+
+![Figure C.21: JPM box structure showing references after length changing protection operations. The diagram shows a sequence of boxes: jP, ftyp, jp2h, jp2c, meta, mhdr, pcol, page, Ciphred xml, Ciphred jp2c, Ciphred jp2c, Ciphred jp2c, page, Ciphred xml, Ciphred jp2c, Ciphred jp2c, Ciphred jp2c. Arrows indicate references from the 'page' boxes to the 'Ciphred xml' and 'Ciphred jp2c' boxes that follow them.](796d2e601722450d6456085e0a801e1e_img.jpg)
+
+T.807(23)\_FC.21
+
+Figure C.21: JPM box structure showing references after length changing protection operations. The diagram shows a sequence of boxes: jP, ftyp, jp2h, jp2c, meta, mhdr, pcol, page, Ciphred xml, Ciphred jp2c, Ciphred jp2c, Ciphred jp2c, page, Ciphred xml, Ciphred jp2c, Ciphred jp2c, Ciphred jp2c. Arrows indicate references from the 'page' boxes to the 'Ciphred xml' and 'Ciphred jp2c' boxes that follow them.
+
+Figure C.21 – JPM box structure showing references after length changing protection operations
+
+C.7 Boxes defined in ISO/IEC 14496-12 (informative)
+
+This clause is not a normative part of this Recommendation | International Standard. The definitions listed here are repeated from ISO/IEC 14496-12 for convenience.
+
+Box
+
+Files are formed as a series of objects, called boxes in this Recommendation | International Standard. All data are contained in boxes; there are no other data within the file.
+
+Boxes start with a header which gives both size and type. The header permits compact or extended size (32 or 64 bits) and compact or extended types (32 bits or full UUIDs). The standard boxes all use compact types (32-bit) and most boxes will use the compact (32-bit) size. Typically only the Media Data Box(es) need the 64-bit size.
+
+The size is the entire size of the box, including the size and type header, fields, and all contained boxes. This facilitates general parsing of the file. The definitions of boxes are given in the syntax description language (SDL) defined in MPEG-4 (see reference in clause 2). Comments in the code fragments in this Recommendation | International Standard indicate informative material. The fields in the objects are stored with the most significant byte first, commonly known as network byte order or big-endian format.
+
+```
+aligned(8) class Box(unsigned int(32) boxtype, optional unsigned int(8)[16] extype) {
+    unsigned int(32)    size;
+    unsigned int(32)    type = boxtype;
+    if (size==1) {
+        unsigned int(64)    argsize;
+    } else if (size == 0) {
+        // box extends to end of file
+    }
+    if (boxtype == 'uuid') {
+        unsigned int(8)[16] usertype = extype;
+    }
+}
+```
+
+The semantics of these two fields are:
+
+`size` is an integer that specifies the number of bytes in this box, including all its fields and contained boxes; if size is 1 then the actual size is in the field `large size`; if size is 0, then this box is the last one in the file, and its contents extend to the end of the file (normally only used for a Media Data Box).
+
+`type` identifies the box type; standard boxes use a compact type, which is normally four printable characters, to permit ease of identification, as reflected below. User extensions use an extended type; in this case, the type field is set to 'uuid'.
+
+Boxes with an unrecognized type shall be ignored and skipped.
+
+Many objects also contain a version number and a flag field:
+
+```
+aligned(8) class FullBox(unsigned int(32) boxtype, unsigned int(8) v, bit(24) f)
+extends Box(boxtype) {
+    unsigned int(8) version = v;
+    bit(24)    flags = f;
+}
+```
+
+The semantics of these two fields are:
+
+`version` is an integer that specifies the version of this format of the box.
+
+`flags` is a map of flags.
+
+Boxes with an unrecognized version shall be ignored and skipped.
+
+## Item Location Box
+
+### Definition
+
+Box Type: 'iloc'
+
+Container: Meta box ('meta')
+
+Mandatory: No
+
+Quantity: Zero or one
+
+The item location box provides a directory of resources in this or other files, by locating their containing file, their offset within that file, and their length. Placing this in binary format enables common handling of this data, even by systems which do not understand the particular metadata system (handler) used. For example, a system might integrate all the externally referenced metadata resources into one file, re-adjusting file offsets and file references accordingly.
+
+The box starts with three values, specifying the size in bytes of the offset field, length field, and `base_offset` field, respectively. These values shall be from the set {0, 4, 8}.
+
+Items can be stored fragmented into extents, e.g., to enable interleaving. An extent is a contiguous subset of the bytes of the resource; the resource is formed by concatenating the extents. If only one extent is used (`extent_count = 1`), then either or both of the offset and length can be implied:
+
+- If the offset is not identified (the field has a length of zero), then the beginning of the file (offset 0) is implied.
+- If the length is not specified, or specified as zero, then the entire file length is implied. References into the same file as this metadata, or items divided into more than one extent, should have an explicit offset and length, or use a MIME type requiring a different interpretation of the file, to avoid infinite recursion.
+
+The size of the `item` is the sum of the `extent_length(s)`.
+
+NOTE – Extents can be interleaved with the chunks defined by the sample tables of tracks.
+
+The data-reference index can take the value 0, indicating a reference into the same file as this metadata, or an index into the data-reference table.
+
+Some referenced data can itself use offset/length techniques to address resources within it (e.g., an MP4 file might be 'included' in this way). Normally such offsets are relative to the beginning of the containing file. The field 'base offset' provides an additional offset for offset calculations within that contained data. For example, if an MP4 file is included within a file formatted to this Recommendation | International Standard, then normally data-offsets within that MP4 section are relative to the beginning of file; `base_offset` adds to those offsets.
+
+## Syntax
+
+```
+aligned(8) class ItemLocationBox() extends FullBox('iloc', version = 0, 0) {
+    unsigned int(4) offset_size;
+    unsigned int(4) length_size;
+    unsigned int(4) base_offset_size;
+    unsigned int(4) reserved;
+    unsigned int(16) item_count;
+    for (i=0; i < item_count; i++) {
+        unsigned int(16) item_ID;
+        unsigned int(16) data_reference_index;
+        unsigned int(base_offset_size*8) base_offset;
+        unsigned int(16) extent_count;
+        for (j=0; j < extent_count; j++) {
+            unsigned int(offset_size*8) extent_offset;
+            unsigned int(length_size*8) extent_length;
+        }
+    }
+}
+```
+
+## Semantics
+
+`offset_size` is taken from the set {0, 4, 8} and indicates the length in bytes of the offset field.
+
+`length_size` is taken from the set {0, 4, 8} and indicates the length in bytes of the length field.
+
+`base_offset_size` is taken from the set {0, 4, 8} and indicates the length in bytes of the `base_offset` field.
+
+`item_count` counts the number of resources in the following array.
+
+`item_ID` is an arbitrary integer 'name' for this resource which can be used to refer to it (e.g., in a URL).
+
+`Data_reference_index` is either zero ('this file') or a 1-based index into the data references in the data information box.
+
+`base_offset` provides a base value for offset calculations within the referenced data. If `base_offset_size` is 0, `base_offset` takes the value 0, i.e., it is unused.
+
+`extent_count` provides the count of the number of extents into which the resource is fragmented; it shall have the value 1 or greater.
+
+`extent_offset` provides the absolute offset in bytes from the beginning of the containing file, of this item. If `offset_size` is 0, offset takes the value 0.
+
+`extent_length` provides the absolute length in bytes of this metadata item. If `length_size` is 0, length takes the value 0. If the value is 0, then length of the item is the length of the entire referenced file.
+
+## Item Information Box
+
+### Definition
+
+Box Type: 'iinf'
+
+## ISO/IEC 15444-8:2023 (E)
+
+Container: Meta Box ('meta')
+
+Mandatory: No
+
+Quantity: Zero or one
+
+The Item information box provides extra information about selected items, including symbolic ('file') names. It can optionally occur, but if it does, it shall be interpreted, as item protection or content encoding can have changed the format of the data in the item. If both content encoding and protection are indicated for an item, a reader should first un-protect the item, and then decode the item's content encoding. If more control is needed, an IPMP sequence code can be used.
+
+This box contains an array of entries, and each entry is formatted as a box. This array is sorted by increasing `item_ID` in the entry records.
+
+### Syntax
+
+```
+aligned(8) class ItemInfoEntry() extends FullBox('infe', version = 0, 0) {
+    unsigned int(16)    item_ID;
+    unsigned int(16)    item_protection_index
+    string              item_name;
+    string              content_type;
+    string              content_encoding; //optional
+}
+
+aligned(8) class ItemInfoBox() extends FullBox('iinf', version = 0, 0) {
+    unsigned int(16)    entry_count;
+    ItemInfoEntry() item_infos[entry_count];
+}
+```
+
+### Semantics
+
+`item_id` contains either 0 for the primary resource (e.g., the XML contained in an 'xml' box) or the ID of the item for which the following information is defined.
+
+`item_protection_index` contains either 0 for an unprotected item, or the one-based index into the item protection box defining the protection applied to this item (the first box in the item protection box has the index 1).
+
+`item_name` is a null-terminated string in UTF-8 characters containing a symbolic name of the item.
+
+`content_type` is the MIME type for the item.
+
+`content_encoding` is an optional null-terminated string in UTF-8 characters used to indicate that the binary file is encoded and needs to be decoded before being interpreted. The values are as defined for Content-Encoding for HTTP/1.1. Some possible values are "gzip", "compress" and "deflate". An empty string indicates no content encoding.
+
+`entry_count` provides a count of the number of entries in the following array.
+
+## Item Protection Box
+
+### Definition
+
+Box Type: 'ipro'
+
+Container: Meta box ('meta')
+
+Mandatory: No
+
+Quantity: Zero or one
+
+The item protection box provides an array of item protection information, for use by the Item Information Box.
+
+### Syntax
+
+```
+aligned(8) class ItemProtectionBox() extends FullBox('ipro', version = 0, 0) {
+    unsigned int(16)    protection_count;
+    for (i=1; i <= protection_count; i++) {
+        ProtectionSchemeInfoBox() protection_information;
+    }
+}
+```
+
+**Semantics**
+
+`protection_count` is the number of protection tools applied.
+
+`protection_information` contains the information for each protection tool applied.
+
+## Annex D
+
+## Technology examples
+
+(This annex does not form an integral part of this Recommendation | International Standard.)
+
+## D.1 Introduction
+
+The JPSEC syntax allows normative and non-normative security tools to be applied to JPEG 2000 images. D.2 to D.11 describe ten informative technology examples that demonstrate different usages of JPSEC. These examples are purely informative and not endorsed by this Recommendation | International Standard. However, they are provided to demonstrate the flexibility of the standard.
+
+The technology examples include:
+
+- A flexible access control scheme for JPEG 2000;
+- A unified authentication framework for JPEG 2000 images;
+- A simple packet-based encryption method for JPEG 2000 codestreams;
+- Encryption tool for JPEG 2000 access control;
+- Key generation tool for JPEG 2000 access control;
+- Wavelet and bitstream domain scrambling for conditional access control;
+- Progressive access for JPEG 2000 codestream;
+- Scalable authenticity of JPEG 2000 codestreams;
+- JPEG 2000 data confidentiality and access control system based on data splitting and luring;
+- Secure scalable streaming and secure transcoding.
+
+## D.2 A flexible access control scheme for JPEG 2000 codestreams
+
+## D.2.1 Security service
+
+An access control scheme allows for rendering JPEG 2000 codestreams according to any combination of resolutions, quality layers, tiles and precincts.
+
+## D.2.2 Typical application
+
+It provides protection of content delivery via variable media, e.g., Internet, digital cable TV, satellite broadcast and CD-ROM. Generally, the technology is viable to the applications where a codestream is encrypted only once on the publisher side but the protected codestream is decrypted many ways according to the different privilege on the user sides.
+
+## D.2.3 Motivation
+
+In the Super-distribution model, the publisher distributes the protected content freely and the content keys securely. A user who desires to access portions of a codestream sends his/her request to the key server. The key server, in turn, responds with appropriate decryption keys according to the user's privilege. The user can access the allowed sub-images.
+
+## D.2.4 Technical overview
+
+A protected JPEG 2000 codestream is produced by encrypting each packet by the publisher. The core of the technology is how to manage a key tree which is constructed in any order of tiles, components, resolutions, layers, precincts, and even code-blocks. To describe the technology easily, assume that the key tree order is RLCP (resolution-layer-component-precinct) and each resolution has the same number of precincts. In the following, given a one-way hash function  $h(\cdot)$ , consider a JPEG 2000 image codestream with  $n_T$  tiles,  $n_C$  components,  $n_L$  layers,  $n_R$  resolution per tile-component,  $n_P$  precincts per resolution. With a master key  $K$  for a JPEG 2000 codestream. Construct a key tree as follows.
+
+- 1) Generate key  $k^t = h(K || "T" || t)$ , for each tile  $T_{\text{type}} = 0, 1, \dots, n_T - 1$ , where  $||$  is the concatenation, and  $"T"$  denotes the ASCII code of the letter  $T$ .
+- 2) Generate key  $k^r = h(k^{r+1})$ , for each  $r = n_R - 2, \dots, 1, 0$ , where  $k^{n_R-1} = h(k^t || "R")$  and  $"R"$  denotes the ASCII code of the letter  $R$ .
+- 3) Compute key  $k^{rl} = h(k^{r(l+1)})$ , for each  $r = n_R - 1, \dots, 1, 0$ ,  $l = n_L - 2, \dots, 1, 0$ , where  $k^{r(n_L-1)} = h(k^r || "L")$  and where  $"L"$  denotes the ASCII code of the letter  $L$ .
+- 4) Calculate key  $k^{rlc} = h(k^{rl} || "C" || c)$ , for each  $r = n_R - 1, \dots, 1, 0$ ,  $l = n_L - 1, \dots, 1, 0$ ,  $c = 0, 1, \dots, n_C - 1$ , where  $"C"$  denotes the ASCII code of the letter  $C$  and  $c$  denotes the index of this component.
+
+- 5) Produce keys  $k^{rlc} = h(k^{rlc} || "P" || p)$ , for each  $r = n_R - 1, \dots, 1, 0, l = n_L - 1, \dots, 1, 0, c = 0, 1, \dots, n_C - 1, p = 0, 1, \dots, n_R - 1$ , where "P" denotes the ASCII code of the letter P and p denotes the index of this precinct.
+
+The protected codestream is generated by encrypting each packet body with its corresponding key (a leaf of the key tree). To render a sub-image from a protected codestream, a user obtains the corresponding access keys (e.g., granted from a key server). These access keys are able to exactly recover the key tree leaves corresponding to the packets of the requested sub-image. The process of key reconstruction is similar to that of key tree generation. The leaves are used to decrypt the corresponding packets.
+
+D.2.5 Codestream syntax
+
+Figure D.1 and Table D.1 illustrate the structure of SEC segment. The ZOI field signals the granted parameters, P<sub>ID</sub> field signals the protection method parameters for this access control scheme. The PM<sub>ID</sub> field is always set to 1 to notify that the decryption template is used. The TP<sub>ID</sub> field signals the additional parameters for this access control scheme. KTO is the key tree generation order. The field L<sub>aki</sub> indicates the length of the access key information.
+
+![Diagram of SEC segment syntax showing fields t, i, ID_RA, L_ZOI, ZOI, L_PID, and P_ID with their respective sizes and labels.](a320e67b369bfde4a5fa360b100da55c_img.jpg)
+
+The diagram shows a sequence of fields in a SEC segment: 't' (8 bits), 'i' (8 bits), 'ID<sub>RA</sub>' (32 bits), 'L<sub>ZOI</sub>' (16 bits), 'ZOI' (variable), 'L<sub>PID</sub>' (16 bits), and 'P<sub>ID</sub>' (variable). The fields are represented as boxes with their labels and sizes. The 'ID<sub>RA</sub>' field is further detailed in Table D.1.
+
+Diagram of SEC segment syntax showing fields t, i, ID\_RA, L\_ZOI, ZOI, L\_PID, and P\_ID with their respective sizes and labels.
+
+Figure D.1 – SEC segment syntax
+
+Table D.1 – Example parameters for this scheme
+
+|                  | Size (bits)                   | Values                      | Meaning                                                    |
+|------------------|-------------------------------|-----------------------------|------------------------------------------------------------|
+| t                | 8 (FBAS)                      | 1                           | Non-normative tool syntax is used                          |
+| i                | 8 (RBAS)                      | Instance value              | Tool instance identifier                                   |
+| ID <sub>RA</sub> | ID <sub>RA,id</sub> 32        | Tool ID value               | Registered ID                                              |
+|                  | ID <sub>RA,nsi</sub> 8 (RBAS) | 21                          | The length of ID <sub>RA,ns</sub> in bytes                 |
+|                  | ID <sub>RA,ns</sub> 168       | Namespace                   | The namespace of the RA with which this tool is registered |
+| L <sub>ZOI</sub> | 16 (RBAS)                     | [2 ... 2 <sup>16</sup> – 1] | Length of ZOI                                              |
+| ZOI              | Variable                      | See 5.7                     | Zone of influence for this scheme                          |
+| L <sub>PID</sub> | 16 (RBAS)                     | [2 ... 2 <sup>16</sup> – 1] | Length of L <sub>PID</sub> + P <sub>ID</sub>               |
+| P <sub>ID</sub>  | Variable                      | See Table D.2               | Parameters for this scheme, see Figure D.2                 |
+
+![Diagram of P_ID field syntax showing fields PM_ID, T_decry, and TD_ID with their respective sizes and labels.](41af98c5f15e6022f8ddde55567cf56e_img.jpg)
+
+The diagram shows the structure of the P<sub>ID</sub> field: 'PM<sub>ID</sub>' (1 bit), 'T<sub>decry</sub>' (8 bits), and 'TD<sub>ID</sub>' (variable). The fields are represented as boxes with their labels and sizes.
+
+Diagram of P\_ID field syntax showing fields PM\_ID, T\_decry, and TD\_ID with their respective sizes and labels.
+
+Figure D.2 – P<sub>ID</sub> field syntax
+
+Table D.2 – P<sub>ID</sub> parameters
+
+| Parameter           | Size (bits) | Values                     | Meaning                                                |
+|---------------------|-------------|----------------------------|--------------------------------------------------------|
+| ID <sub>T</sub> = 1 | 8           | Always set to 1            | Tag for Decryption template                            |
+| T <sub>decry</sub>  | Variable    | Decryption template values | Decryption template                                    |
+| TP <sub>ID</sub>    | Variable    | See Table D.3              | Additional information for this scheme, see Figure D.3 |
+
+![Diagram of TP_ID field syntax showing fields KTO, L_aki, and AK_Info with their respective sizes and labels.](c000f54c4c4bddaccf38fa236c90f280_img.jpg)
+
+The diagram shows the structure of the TP<sub>ID</sub> field: 'KTO' (1 bit), 'L<sub>aki</sub>' (16 bits), and 'AK<sub>Info</sub>' (variable). The fields are represented as boxes with their labels and sizes.
+
+Diagram of TP\_ID field syntax showing fields KTO, L\_aki, and AK\_Info with their respective sizes and labels.
+
+Figure D.3 – TP<sub>ID</sub> field syntax
+
+Table D.3 – TPID parameters
+
+| Parameter          | Size (bits) | Values                      | Meaning                                                                                                                                                                           |
+|--------------------|-------------|-----------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| KTO                | 8           | 0 ... (2 <sup>8</sup> – 1)  | Key Tree order. It can be different from the codestream progression order, tentatively,<br>0x00: LRCP    0x01: RLCP<br>0x02: RPCL    0x03: PCRL<br>0x04: CPRL    others: Reserved |
+| L <sub>aki</sub>   | 16          | 0 ... (2 <sup>16</sup> – 1) | Length of access key information, if L <sub>aki</sub> = 0, no AK <sub>info</sub> field is presented                                                                               |
+| AK <sub>info</sub> | Variable    | See Table D.4               | Information on the access key, see Figure D.4 (e.g., length of key, number of keys)                                                                                               |
+
+![Figure D.4 – AKinfo field syntax diagram. It shows a sequence of fields: L_uk (16 bits), UK (User key information, shaded), E_ak (16 bits), N_ak (16 bits), and AK (Access keys, shaded). The label T.807(23)_FD.4 is at the bottom right.](6a993bfdf2e00cfad01c4d2188a75d86_img.jpg)
+
+T.807(23)\_FD.4
+
+Figure D.4 – AKinfo field syntax diagram. It shows a sequence of fields: L\_uk (16 bits), UK (User key information, shaded), E\_ak (16 bits), N\_ak (16 bits), and AK (Access keys, shaded). The label T.807(23)\_FD.4 is at the bottom right.
+
+Figure D.4 – AK<sub>info</sub> field syntax
+
+Table D.4 – AK<sub>info</sub> parameters
+
+| Parameter       | Size (bits)                       | Values                      | Meaning                                |
+|-----------------|-----------------------------------|-----------------------------|----------------------------------------|
+| L <sub>uk</sub> | 16                                | 0 ... (2 <sup>16</sup> – 1) | Length of the user key                 |
+| UK              | L <sub>uk</sub>                   | NaN                         | User key information                   |
+| E <sub>ak</sub> | 16                                | See Table 24                | Cipher used to encrypt the access keys |
+| N <sub>ak</sub> | 16                                | 0 ... (2 <sup>16</sup> – 1) | Number of access keys                  |
+| AK              | N <sub>ak</sub> * K <sub>bc</sub> | NaN                         | Access keys                            |
+
+D.2.6 Conclusion
+
+This technology enables a publisher to protect a JPEG 2000 codestream with a master key. The protected codestream is permitted to be delivered to any number of users, but the keys for packets are kept secret. The key server generates different access keys for the users according to their priorities. The users generate the granted packets keys from their access keys and get different granted images. That is to say, the technology has the property called "*encrypt once, access many ways*".
+
+D.3 A unified authentication framework for JPEG 2000 images
+
+D.3.1 Operational description
+
+This JPSEC tool provides the following JPSEC services: image data/content integrity verification and source authentication, i.e., fragile/semi-fragile authentication for JPEG 2000 images based on digital signature schemes.
+
+As this tool supports both fragile and semi-fragile authentications, it can be used in different application scenarios, including image distribution, image streaming, medical and military imaging, law enforcement, E-commerce and E-government.
+
+In pervasive environment, images might experience various kinds of incidental distortions like transcoding and format conversion. Traditional cryptography-based authentication techniques protect JPEG 2000 images at data integrity level and cannot survive these types of content-preserving distortions. Therefore, semi-fragile authentication techniques are required to protect JPEG 2000 images at image content level. This tool unifies both image data and image content authentication and proposes a new concept called lowest authentication bit rate (LABR). That is, if the image is transcoded to a bit rate that is not less than the LABR, it will be rendered as authentic, otherwise, unauthentic. The authentication can be fragile or semi-fragile authentication. In semi-fragile authentication, the tool is able to identify the place where alteration has taken place when the image is deemed unauthentic.
+
+D.3.2 Technical overview
+
+To provide fragile and semi-fragile authentication, a group of techniques has been applied in this JPSEC informative tool. They include feature selection, digital signature, lossy and lossless data hiding, and ECC (error correction codes). According to the LABR specified by users, the corresponding features are selected based on an analysis applied to JPEG 2000 structure, and digital signature is then generated. For semi-fragile authentication, ECC is utilized to enhance the
+
+robustness level. The parity check bits (PCB) are embedded into the image as watermark so as to identify locations of the attack. Data embedding can be conducted in two different ways: lossy and lossless. With lossy data hiding, the original image cannot be recovered after data hiding. With lossless data hiding, on the other hand, the image is modified in a reversible way, i.e., the original image can be recovered if the marked image has not been altered. The lossless semi-fragile authentication is useful for JPEG 2000 since the standard supports lossy-to-lossless compression. In particular, it is useful to medical imaging and remote-imaging applications, where lossless is an essential requirement.
+
+Similar to image compression bit rate, which is used to control and characterize the compression strength, the LABR (lowest authentication bit rate) parameter is used to quantitatively control the protection strength. For example, when a JPEG 2000 image is protected with a LABR of 2 bpp (bits per pixel), any transcoded version of the image will be rendered as authentic by the proposed system as long as the bit rate after transcoding is greater than or equal to 2 bpp.
+
+Figure D.5 illustrates how the tool can be used to protect images.
+
+![Figure D.5: Image protection using unified authentication framework for JPEG 2000. The diagram shows the flow from encoding to decoding. On the left, 'Encoding parameters' (CBR, Original image, Private key, Auth. parameters, LABR) feed into an 'Encoder'. The Encoder contains 'JPEG 2000 encoding', 'Fragile sign', 'Semi-fragile sign (lossy)', and 'Semi-fragile sign (lossless)'. The output is a 'JPSEC codestream'. This codestream goes through 'Parsing/truncation', 'Multi-cycle JPEG 2000 coding', 'Lossy compression (e.g., JPEG)', and 'Format conversion'. The result is another 'JPSEC codestream' which enters a 'Decoder'. The Decoder contains 'JPEG 2000 decoding', 'Fragile verify', 'Semi-fragile verify (lossy)', and 'Semi-fragile verify (lossless)'. The final outputs are 'Decoded image' and 'Authentic? (Attacked area)'. A reference 'T.807(23)_FD.5' is at the bottom right.](c00d3fb4f9d9609639a6e7d7a356afd3_img.jpg)
+
+Figure D.5: Image protection using unified authentication framework for JPEG 2000. The diagram shows the flow from encoding to decoding. On the left, 'Encoding parameters' (CBR, Original image, Private key, Auth. parameters, LABR) feed into an 'Encoder'. The Encoder contains 'JPEG 2000 encoding', 'Fragile sign', 'Semi-fragile sign (lossy)', and 'Semi-fragile sign (lossless)'. The output is a 'JPSEC codestream'. This codestream goes through 'Parsing/truncation', 'Multi-cycle JPEG 2000 coding', 'Lossy compression (e.g., JPEG)', and 'Format conversion'. The result is another 'JPSEC codestream' which enters a 'Decoder'. The Decoder contains 'JPEG 2000 decoding', 'Fragile verify', 'Semi-fragile verify (lossy)', and 'Semi-fragile verify (lossless)'. The final outputs are 'Decoded image' and 'Authentic? (Attacked area)'. A reference 'T.807(23)\_FD.5' is at the bottom right.
+
+Figure D.5 – Image protection using unified authentication framework for JPEG 2000
+
+This tool can use different signalling syntaxes depending on the chosen authentication method. For fragile authentication, it uses the JPSEC normative tool syntax, as defined in 5.8.3. For semi-fragile authentication, it uses the JPSEC non-normative tool syntax, as illustrated in Table D.5. In addition, the  $F_{INSEC}$  should be set to 0 as INSEC marker is not used by this tool, and  $F_{mod}$  should be set to 1 because the resulted codestream of this JPSEC tool is still compliant with the JPEG 2000 Core coding system.
+
+Table D.5 – Syntax for semi-fragile authentication
+
+| Parameter        |                      | Size (bits)       | Value                       | Derived meaning                                            |  |
+|------------------|----------------------|-------------------|-----------------------------|------------------------------------------------------------|--|
+| t                |                      | 8 (FBAS)          | 1                           | Non-normative tool syntax is used                          |  |
+| i                |                      | 8 (RBAS)          | 0 ... (2 <sup>7</sup> – 1)  | Tool instance index                                        |  |
+| ID <sub>RA</sub> | ID <sub>RA,id</sub>  | 32                | 0 ... (2 <sup>32</sup> – 1) | ID number to be assigned by RA                             |  |
+|                  | ID <sub>RA,nsi</sub> | 8 (RBAS)          | 21                          | The length of ID <sub>RA,ns</sub> in bytes                 |  |
+|                  | ID <sub>RA,ns</sub>  | 168               | <i>namespace</i>            | The namespace of the RA with which this tool is registered |  |
+| L <sub>ZOI</sub> |                      | 16 (RBAS)         | 0 ... (2 <sup>16</sup> – 1) | Length of ZOI                                              |  |
+| ZOI              |                      | Variable          | <i>ZOI values</i>           | The covered zone in the image protected by the tool        |  |
+| L <sub>PID</sub> |                      | 16 (RBAS)         | 0 ... (2 <sup>16</sup> – 1) | Length of P <sub>ID</sub> and L <sub>PID</sub> in bytes    |  |
+| P <sub>ID</sub>  | ID <sub>T</sub>      | 8                 | 2                           | Authentication Template is used, as defined in Table 21    |  |
+|                  | T <sub>auth</sub>    | M <sub>auth</sub> | 8                           | Digital Signature Method is used, as defined in Table 34   |  |
+|                  |                      |                   |                             |                                                            |  |
+|                  |                      | P <sub>auth</sub> | M <sub>DS</sub>             | See Table 41                                               |  |
+|                  |                      |                   | H <sub>DS</sub>             | See Table 37                                               |  |
+|                  |                      |                   | KT <sub>DS</sub>            | Variable                                                   |  |
+|                  | SIZ <sub>DS</sub>    |                   | 16                          | 0 ... (2 <sup>16</sup> – 1)                                |  |
+| P <sub>ID</sub>  | PD                   |                   | 1                           | 0 <sub>b</sub>                                             |  |
+|                  |                      |                   | 1                           | 0 <sub>b</sub>                                             |  |
+|                  |                      |                   | 1                           | 0 <sub>b</sub>                                             |  |
+
+Table D.5 – Syntax for semi-fragile authentication
+
+| Parameter |           | Size (bits)         | Value             | Derived meaning                                                                                                                   |
+|-----------|-----------|---------------------|-------------------|-----------------------------------------------------------------------------------------------------------------------------------|
+|           |           | 1                   | 1 <sub>b</sub>    | Quantized wavelet coefficients domain is used                                                                                     |
+|           |           | 1                   | 0 <sub>b</sub>    | Codestream domain is not used                                                                                                     |
+|           |           | 3                   | 000 <sub>b</sub>  | Reserved for ITU-T   ISO use                                                                                                      |
+|           | G         | PO                  | 16                | <i>Processing order values</i><br>Processing order                                                                                |
+|           |           | GL                  | 8                 | 0000 1001<br>Granularity level: Unit of protection is total area identified in ZOI                                                |
+|           | V         | N <sub>v</sub>      | 16                | 1<br>Number of digital signatures in the list is 1                                                                                |
+|           |           | S <sub>v</sub>      | 8 (RBAS)          | 1 ... (2 <sup>8</sup> – 1)<br>Size of the digital signature in bytes                                                              |
+|           |           | VL                  | 8* S <sub>v</sub> | <i>Digital signature value</i><br>The digital signatures generated by the tool                                                    |
+|           | LABR      | LABR <sub>int</sub> | 8                 | 0 ... (2 <sup>8</sup> – 1)<br>The integer part of LABR                                                                            |
+|           |           | LABR <sub>fra</sub> | 8                 | 0 ... (2 <sup>8</sup> – 1)<br>The fractional part of LABR                                                                         |
+|           | Threshold |                     | 8                 | [0 ... 2 <sup>8</sup> – 1]<br>The threshold value. (Valid only for lossless authentication.)                                      |
+|           | Shuffle   |                     | 8                 | [0 ... 2 <sup>8</sup> – 1]<br>The number of shuffling in order to embed watermark bits. (Valid only for lossless authentication.) |
+
+D.3.3 Conclusions
+
+In summary, this tool has achieved the following special features:
+
+- Authentication for JPEG 2000 images at either image data level or image content level by integrating fragile and semi-fragile authentication in one framework. Furthermore, the semi-fragile authentication includes both lossy and lossless modes.
+- Robustness against various incidental distortions like introduced by transcoding, format conversion, lossy compression and multi-cycle of JPEG 2000 coding. Therefore, this tool can be used to protect JPEG 2000 images in pervasive environment.
+- Scalable protection of the JPEG 2000 images. Specifically, this tool is able to protect any tile, component, resolution, layer, precinct, or codeblock.
+- Compatibility with state-of-arts information security framework called Public Key Infrastructure which is the basis of existing international standards like ITU-T X.509.
+- Quantitative protection strength controlled by a single parameter called LABR, which brings much convenience to end users.
+- Capability to locate the possibly attacked image areas if the image is deemed unauthentic. It could help to visually convince the users.
+- Support for lossy-to-lossless protection, corresponding to lossy-to-lossless compression of JPEG 2000 coding standards. Thus, the tool has much broader applications, including medical imaging and remote imaging applications.
+
+D.4 A simple packet-based encryption method for JPEG 2000 codestreams
+
+D.4.1 Operational description
+
+This clause presents a selective encryption technique for JPEG 2000 images. It is based on a packet level encryption and on standard robust cipher algorithms.
+
+The security service addressed by the technique is confidentiality of JPEG 2000 images, obtained through ciphering of the codestream. Consequently, IPR protection as well as privacy protection can be achieved using this technique.
+
+The approach supports transcoding, scalability, and other content processing functionality without having to access the cryptographic key and to perform decryption and re-encryption. It does not interfere with the coding and decoding processes and has very limited adverse impact on the compression efficiency and no adverse impact on error resilience. Such an approach allows a maximum flexibility to implement scenarios and applications with various levels of security.
+
+The technique can be used by content producers to limit the access to the image content or by content providers to insure confidential delivery of the content to the end users.
+
+D.4.2 Technical overview
+
+The technique consists of encrypting the codestream after compression of the image, as shown in Figure D.6.
+
+![Figure D.6 – Packet-based encryption principle. The diagram shows a flow from an image to Wavelet transform, Rate allocation, Entropy coding, and Scalar quantization. These steps lead to a 'Packet-based encryption' block. Below, a 'Codestream' is shown with a 'Header' and several 'Packets' (Packet 1, Packet 2, Packet 3, Packet 4, Packet n). Red dashed boxes highlight the payloads of Packet 1, Packet 2, Packet 3, and Packet 4. Red arrows point from these highlighted areas to a label 'Protection of pack-stream'. A reference 'T.807(23)_FD.6' is at the bottom right.](0b998e3ad8f9d104768642612605cb35_img.jpg)
+
+Figure D.6 illustrates the packet-based encryption principle. It shows the process starting with an image, followed by Wavelet transform, Rate allocation, Entropy coding, and Scalar quantization. The resulting codestream is divided into a Header and multiple Packets (Packet 1, Packet 2, Packet 3, Packet 4, Packet n). The payloads of Packets 1 through 4 are highlighted with red dashed boxes, and red arrows indicate the application of 'Protection of pack-stream' to these specific packets. The diagram is referenced as T.807(23)\_FD.6.
+
+Figure D.6 – Packet-based encryption principle. The diagram shows a flow from an image to Wavelet transform, Rate allocation, Entropy coding, and Scalar quantization. These steps lead to a 'Packet-based encryption' block. Below, a 'Codestream' is shown with a 'Header' and several 'Packets' (Packet 1, Packet 2, Packet 3, Packet 4, Packet n). Red dashed boxes highlight the payloads of Packet 1, Packet 2, Packet 3, and Packet 4. Red arrows point from these highlighted areas to a label 'Protection of pack-stream'. A reference 'T.807(23)\_FD.6' is at the bottom right.
+
+Figure D.6 – Packet-based encryption principle
+
+This JPSEC tool can take several image-related parameters as an input: resolution levels, quality layers, components, precincts or tiles. Only the packet payloads corresponding to these input parameters are then processed. Thus, the protected codestream keeps a regular JPEG 2000 structure. Once the codestream has been ciphered, the SEC marker segment is added to the main header to allow any JPSEC consumer to correctly decrypt the image later on.
+
+This method uses well known standard underlying algorithms to selectively encrypt the packets: DES or AES methods, associated with standard modes described in [18] such as ECB, CBC, CFB, OFB and CTR. Any other block cipher algorithms could of course be used: DES and AES are given here as examples of standard ciphers.
+
+D.4.2.1 Signalling example
+
+The technique can be signalled with the template based syntax of the normative clause. Below is an example of signalling for this technique (see Table D.6), which specifies one zone for the ZOI, but of course there could be more, following the same syntax as Zone<sup>0</sup>.
+
+Table D.6 – Example of Zone of Influence, with spatial coordinates, resolutions and layers
+
+| Parameter         |                   |                   | Size (bits) | Value (in order) | Derived meaning                                                                        |
+|-------------------|-------------------|-------------------|-------------|------------------|----------------------------------------------------------------------------------------|
+| NZzoi             |                   |                   | 8           | 1 (RBAS)         | Number of Zones is one                                                                 |
+| Zone <sup>0</sup> | DCzoi             |                   | 1           | 0                | The byte aligned segment does not follow                                               |
+|                   |                   |                   | 1           | 0                | Image related description class                                                        |
+|                   |                   |                   | 6           | 101100           | Image regions, resolution levels, quality layers and components are specified in order |
+|                   | Pzoi <sup>1</sup> | Mzoi <sup>1</sup> | 1           | 0                | The byte aligned segment does not follow                                               |
+|                   |                   |                   | 1           | 0                | The specified zones are influenced by the protection method                            |
+|                   |                   |                   | 1           | 0                | Single item is specified                                                               |
+|                   |                   |                   | 2           | 00               | Rectangle mode                                                                         |
+|                   |                   |                   | 2           | 00               | Izoi uses 8-bit integer                                                                |
+|                   |                   |                   | 1           | 1                | Izoi is described in two dimensions                                                    |
+|                   |                   | Izoi <sup>1</sup> | 8           | 0110 0100        | Xul is 100                                                                             |
+|                   |                   |                   | 8           | 0111 1000        | Yul is 120                                                                             |
+|                   |                   |                   | 8           | 1011 0100        | Xlr is 180                                                                             |
+|                   |                   |                   | 8           | 1101 0010        | Ylr is 210                                                                             |
+|                   | Pzoi <sup>3</sup> | Mzoi <sup>3</sup> | 1           | 0                | The byte aligned segment does not follow                                               |
+|                   |                   |                   | 1           | 1                | The specified zones are not influenced by the protection method                        |
+|                   |                   |                   | 1           | 0                | Single item is specified                                                               |
+|                   |                   |                   | 2           | 11               | Max mode                                                                               |
+
+Table D.6 – Example of Zone of Influence, with spatial coordinates, resolutions and layers
+
+| Parameter |                   |                   | Size (bits) | Value (in order) | Derived meaning                                                                                                       |
+|-----------|-------------------|-------------------|-------------|------------------|-----------------------------------------------------------------------------------------------------------------------|
+|           |                   |                   | 2           | 00               | Izoi uses 8-bit integer                                                                                               |
+|           |                   |                   | 1           | 0                | Izoi is described in one dimension                                                                                    |
+|           |                   | Izoi <sup>3</sup> | 8           | 0000 0010        | Resolution levels ≤ 2 are specified. (i.e., Resolution levels > 3 are specified with Max mode and complement switch.) |
+|           | Pzoi <sup>4</sup> | Mzoi <sup>4</sup> | 1           | 0                | The byte aligned segment does not follow                                                                              |
+|           |                   |                   | 1           | 0                | The specified zones are influenced by the protection method                                                           |
+|           |                   |                   | 1           | 0                | Single item is specified                                                                                              |
+|           |                   |                   | 2           | 11               | Max mode                                                                                                              |
+|           |                   |                   | 2           | 00               | Izoi uses 8-bit integer                                                                                               |
+|           |                   |                   | 1           | 0                | Izoi is described in one dimension                                                                                    |
+|           |                   | Izoi <sup>4</sup> | 8           | 0000 0101        | Layers ≤ 5 are specified with Max mode                                                                                |
+
+Table D.7 – Decryption template description, in the case of AES-192/CBC
+
+| Parameter |                     |                   | Size (bits)       | Value     | Derived meaning                             |                                                                                                                                              |
+|-----------|---------------------|-------------------|-------------------|-----------|---------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------|
+| PPM       | ME <sub>decry</sub> |                   | 8                 | 0000 0000 | NULL: no marker emulation prevention method |                                                                                                                                              |
+|           | CT <sub>decry</sub> |                   | 16                | 0x0003    | Cipher identifier: AES (block cipher)       |                                                                                                                                              |
+|           | CP <sub>decry</sub> | M <sub>bc</sub>   | 6                 | 10 0000   | Cipher mode: CBC                            |                                                                                                                                              |
+|           |                     | P <sub>bc</sub>   | 2                 | 01        | Padding mode (PKCS#7-padding)               |                                                                                                                                              |
+|           |                     | SIZ <sub>bs</sub> | 8                 | 0001 0000 | Size of block: 16 bytes (128 bits)          |                                                                                                                                              |
+|           |                     | KT <sub>bc</sub>  | LK <sub>KT</sub>  | 16        | 0x00C0                                      | Size of key: 192 bits                                                                                                                        |
+|           |                     |                   | KID <sub>KT</sub> | 8         | 0000 0011                                   | Key information is a URI                                                                                                                     |
+|           |                     |                   | LKI <sub>KT</sub> | 16        | 0x0021 (=33)                                | Length of the URI: 33 bytes                                                                                                                  |
+|           |                     |                   | KI <sub>KT</sub>  | 264       | https://server/path/secretkey.pem           | This URI is an https URL; it has to be understood by the application using JPSEC. The effective retrieval of the key is beyond the standard. |
+|           |                     | G <sub>KT</sub>   | PO                | 16        | 0 000 001 010 011 100                       | Processing order is TRLCP                                                                                                                    |
+|           |                     |                   | GV                | 8         | 0000 1001                                   | Granularity of key is total area in ZOI                                                                                                      |
+|           |                     | V <sub>KT</sub>   | NV                | 16        | 0x0001                                      | Single key value in KI <sub>KT</sub> ; Values not specified in V <sub>KT</sub>                                                               |
+|           |                     |                   | Sv                | 16        | 0010 0001                                   | Length of the URI: 33 bytes                                                                                                                  |
+|           |                     |                   | VL                | 264       | https://server/path/secretkey.pem           | This URI is an https URL; it has to be understood by the application using JPSEC. The effective retrieval of the key is beyond the standard. |
+
+Table D.8 – Processing domain syntax
+
+| Parameter | Size (bits) | Value            | Derived meaning                             |
+|-----------|-------------|------------------|---------------------------------------------|
+| PD        | 1           | 0 <sub>b</sub>   | The byte aligned segment does not follow    |
+|           | 1           | 0 <sub>b</sub>   | Not in pixel domain                         |
+|           | 1           | 0 <sub>b</sub>   | Not in wavelet coefficient domain           |
+|           | 1           | 0 <sub>b</sub>   | Not in quantized wavelet coefficient domain |
+|           | 1           | 1 <sub>b</sub>   | Processed in codestream domain              |
+|           | 3           | 000 <sub>b</sub> | Not used                                    |
+
+Table D.9 – Granularity and value list syntax
+
+| Parameter |    | Size (bits) | Value                 | Derived meaning               |
+|-----------|----|-------------|-----------------------|-------------------------------|
+| G         | PO | 16          | 0 000 001 010 011 100 | Processing order is TRLCp     |
+|           | GV | 8           | 0000 0110             | Unit of protection is packet  |
+| V         | Nv | 16          | 1                     | Number of IV values specified |
+|           | Sv | 8           | 16                    | IV size in bytes              |
+|           | VL | 128         | <i>Value</i>          | IV value                      |
+
+### D.4.3 Conclusion
+
+The technique presented in this clause demonstrates selective encryption for JPEG 2000 images. It is based on a packet level encryption and on standard robust cipher algorithms. It can be signalled using the templates defined in 5.8 and supports various levels of complexity.
+
+## D.5 Encryption tool for JPEG 2000 access control
+
+### D.5.1 Security services addressed
+
+This technology provides an encryption tool which can prevent marker emulation in an encrypted codestream.
+
+### D.5.2 Typical applications
+
+This technology allows selective and full encryption of JPEG 2000 codestreams. Such selective encryption methods can be used to display only an approved image, such as a thumbnail, a low quality image, and a partially scrambled image.
+
+### D.5.3 Potential users, implementation model and motivations
+
+Basically, this technology is based on a packet-based encryption for a JPEG 2000 codestream with well-known cipher algorithm. Specifically, this technology prevents marker emulation in the encrypted codestream. Therefore, even if the resulting encrypted codestream is input to a JPEG 2000 Core coding system compatible decoder, the decoder is unlikely to crash and can play the protected image correctly.
+
+### D.5.4 Technical overview
+
+#### (1) Encryption
+
+**Step 1** 2 (bytes) code is temporarily encrypted using well-known cipher algorithm.
+
+**Step 2** If the temporarily encrypted code or its relating code is more than 0xFF8F, then the 2 (bytes) code is not encrypted.
+
+Otherwise, the temporarily encrypted code is output as the encrypted code.
+
+**Step 3** Moving on the next 2 (bytes) code, and Step 1 and Step 2 are continued.
+
+All 2 (bytes) code in the plain text are less than 0xFF90 according to the JPEG 2000 Core coding system specification. Further, if the temporarily encrypted code or its relating code is more than 0xFF8F, then the 2 (bytes) code is not encrypted. As a result, all 2 (bytes) code in the cipher text is less than 0xFF90.
+
+If the length of plaintext is odd, an exception to the processing occurs; the last byte is not encrypted or padded with one extra byte.
+
+#### (2) Decryption
+
+**Step 1** 2 (bytes) code is temporarily decrypted using the same cipher algorithm as the encryption.
+
+**Step 2** If the temporarily decrypted code or its relating code is more than 0xFF8F, then the 2 (bytes) code is not decrypted. Otherwise, the temporarily decrypted code is output as the decrypted code.
+
+**Step 3** Moving on the next 2 (bytes) code, and Step 1 and Step 2 are continued.
+
+All 2 (bytes) code in the original plain text before encryption are less than 0xFF90. So it is possible to make a decision that the 2 (bytes) code is not encrypted if the temporal decrypted code or its relating code is more than 0xFF8F.
+
+## D.5.5 Signalling method
+
+Table D.10 shows example parameters for this technology. Any parameters for this technology are signalled according to the syntax which is identified in this Recommendation | International Standard. Especially, this technology should use "decryption" template, "packet" granularity, and "bitstream" processing domain with the appropriate ZOI.
+
+Table D.10 – Example parameters for this technology
+
+| Parameter        |                       | Size (bits) | Value                    | Meaning                                                     |
+|------------------|-----------------------|-------------|--------------------------|-------------------------------------------------------------|
+| SEC              |                       | 16          | 0xFF65                   | SEC marker                                                  |
+| L <sub>SEC</sub> |                       | 16          | Variable                 | Length of SEC marker segment                                |
+| Z <sub>SEC</sub> |                       | 8           | 1 (example)              | Index of this SEC marker segment                            |
+| P <sub>SEC</sub> |                       | 1           | 0                        | FBAS byte does not follow                                   |
+|                  | F <sub>INSEC</sub>    | 1           | 1 (example)              | INSEC is used                                               |
+|                  | F <sub>multiSEC</sub> | 1           | 0 <sub>b</sub>           | One SEC marker segment is used                              |
+|                  | F <sub>mod</sub>      | 1           | 1 <sub>b</sub>           | Original JPEG 2000 data was modified                        |
+|                  | F <sub>TRLCP</sub>    | 1           | 0 <sub>b</sub>           | TRLCP tag usage is not defined                              |
+|                  | Padding               | 3           | 000 <sub>b</sub>         | Not used                                                    |
+|                  | N <sub>tools</sub>    | 8 (RBAS)    | 1                        | Number of security tool is one                              |
+|                  | I <sub>max</sub>      | 8 (RBAS)    | 0                        | Maximum tool instance index is zero                         |
+| t                |                       | 8 (FBAS)    | 1                        | JPSEC non-normative tool                                    |
+| i                |                       | 8 (RBAS)    | 0000000 <sub>b</sub>     | Tool instance index                                         |
+| ID <sub>RA</sub> | ID <sub>RA,id</sub>   | 32          | 0                        | Registered ID                                               |
+|                  | ID <sub>RA,ns1</sub>  | 8 (RBAS)    | 21                       | The length of ID <sub>RA,ns</sub> in bytes                  |
+|                  | ID <sub>RA,ns</sub>   | 168         | <i>namespace</i>         | The name space of the RA with which this tool is registered |
+| L <sub>zoi</sub> |                       | 16          | 9                        | Length of ZOI is 9 bytes                                    |
+| ZOI              |                       | Variable    | See Table D.11 (example) | Zone of Influence for this tool                             |
+| L <sub>PID</sub> |                       | 16          | Variable                 | Length of L + T + PD + G                                    |
+| P <sub>ID</sub>  |                       | Variable    | See Table D.12 (example) | Parameters for this technology                              |
+
+Table D.11 – Example ZOI of this key generation tool
+
+| Parameter         |                               |                               | Size (bits) | Value (in order)       | Derived meaning                                                 |
+|-------------------|-------------------------------|-------------------------------|-------------|------------------------|-----------------------------------------------------------------|
+| ND <sub>zoi</sub> |                               |                               | 8           | 1                      | Number of Zones is one                                          |
+| Zone <sup>0</sup> | D <sub>zoi</sub>              |                               | 1           | 0 <sub>b</sub>         | The byte aligned segment does not follow                        |
+|                   |                               |                               | 1           | 0 <sub>b</sub>         | Image related description class                                 |
+|                   |                               |                               | 6           | 101000 <sub>b</sub>    | Image regions and resolution levels are specified in order      |
+|                   | P <sub>zoi</sub> <sup>1</sup> | M <sub>zoi</sub> <sup>1</sup> | 1           | 0 <sub>b</sub>         | The byte aligned segment does not follow                        |
+|                   |                               |                               | 1           | 0 <sub>b</sub>         | The specified zones are influenced by the protection method     |
+|                   |                               |                               | 1           | 0 <sub>b</sub>         | Single item is specified                                        |
+|                   |                               |                               | 2           | 00 <sub>b</sub>        | Rectangle mode                                                  |
+|                   |                               |                               | 2           | 00 <sub>b</sub>        | I <sub>zoi</sub> uses 8-bit integer                             |
+|                   |                               |                               | 1           | 1 <sub>b</sub>         | I <sub>zoi</sub> is described in two dimensions                 |
+|                   |                               | I <sub>zoi</sub> <sup>1</sup> | 8           | 0110 0100 <sub>b</sub> | X <sub>ul</sub> is 100                                          |
+|                   |                               |                               | 8           | 0111 1000 <sub>b</sub> | Y <sub>ul</sub> is 120                                          |
+|                   |                               |                               | 8           | 1011 0100 <sub>b</sub> | X <sub>lr</sub> is 180                                          |
+|                   |                               |                               | 8           | 1101 0010 <sub>b</sub> | Y <sub>lr</sub> is 210                                          |
+|                   | P <sub>zoi</sub> <sup>3</sup> | M <sub>zoi</sub> <sup>3</sup> | 1           | 0 <sub>b</sub>         | The byte aligned segment does not follow                        |
+|                   |                               |                               | 1           | 1 <sub>b</sub>         | The specified zones are not influenced by the protection method |
+|                   |                               |                               | 1           | 0 <sub>b</sub>         | Single item is specified                                        |
+|                   |                               |                               | 2           | 11 <sub>b</sub>        | Max mode                                                        |
+
+Table D.11 – Example ZOI of this key generation tool
+
+| Parameter |  |                   | Size (bits) | Value (in order)       | Derived meaning                     |
+|-----------|--|-------------------|-------------|------------------------|-------------------------------------|
+|           |  |                   | 2           | 00 <sub>b</sub>        | Izoi uses 8-bit integer             |
+|           |  |                   | 1           | 0 <sub>b</sub>         | Izoi is described in one dimension  |
+|           |  | Izoi <sup>3</sup> | 8           | 0000 0010 <sub>b</sub> | Resolution levels > 3 are specified |
+
+Table D.12 – P<sub>ID</sub> for this technology
+
+| Parameter |    | Size (bits) | Value                                | Meaning                                                       |
+|-----------|----|-------------|--------------------------------------|---------------------------------------------------------------|
+| T         |    | Variable    | See Table D.13                       | Decryption templates                                          |
+| PD        |    | 8           | 0000 1000 <sub>b</sub>               | FBAS byte does not follow. Processed in codestream domain.    |
+| G         | PO | 16          | 0 000 001 010 011 100 0 <sub>b</sub> | Processing order is tile-resolution-layer-component-precinct. |
+|           | GL | 8           | 0000 0110 <sub>b</sub>               | Unit of protection is packet                                  |
+| Skip      |    | 8           | 0                                    | <i>Skip</i> parameter for this tool                           |
+
+Table D.13 – Example of decryption template of this technology
+
+| Parameter           |                   | Size (bits) | Value (in order)            | Derived meaning                          |
+|---------------------|-------------------|-------------|-----------------------------|------------------------------------------|
+| ME <sub>decry</sub> |                   | 8           | 1                           | Marker emulation has not occurred        |
+| CT <sub>decry</sub> |                   | 16          | 1                           | Block cipher (AES)                       |
+| CP <sub>decry</sub> | M <sub>bc</sub>   | 6           | 10 0010 <sub>b</sub>        | OFB mode is used. (Bits are not padded.) |
+|                     | SIZ <sub>bc</sub> | 16          | 128                         | Block size (128 bits)                    |
+|                     | KT <sub>bc</sub>  | Variable    | <i>Key template values</i>  | Key template                             |
+|                     | IV <sub>sc</sub>  | 128         | <i>Initial vector value</i> | Initial vector value                     |
+
+D.5.6 Conclusion
+
+This clause described an encryption technology for a JPEG 2000 codestream. The significant advantage of this technology is to prevent marker emulation from occurring in the encrypted codestream.
+
+D.6 Key generation tool for JPEG 2000 access control
+
+D.6.1 Security services addressed
+
+This technology provides an image related access control for JPEG 2000 according to a hierarchical structure in JPEG 2000.
+
+D.6.2 Typical applications
+
+A typical application of this technology is secure image distribution where only an authorized user can play the accepted image. For example, a thumbnail is free to display, but a large resolution image can be decoded by only the user who owns the key.
+
+D.6.3 Potential users, implementation model and motivations
+
+This technology supports to generate keys to be used in a secure JPEG 2000 image distribution. This technology is based on an image related access control, such as image region, resolution and image quality. The principle of this technology is to generate encryption and decryption keys hierarchically using a cryptographic one-way hash function such as a hash function.
+
+D.6.4 Technical overview
+
+![Figure D.7: Overview of this technology. The diagram shows a workflow for image encryption and decryption. A 'Plain image' (a colorful bird) is input to a 'Creator' block. The 'Creator' outputs a 'Protected image' (a blurred, grayscale version of the bird). The 'Protected image' is input to a 'Viewer' block. The 'Viewer' outputs an 'Accepted image (e.g., thumbnail)' (a small, clear version of the bird). A 'Key server' block is connected to the 'Creator' and the 'Viewer'. The 'Key server' receives 'Granted resolution, quality, and/or region' as input. The 'Key server' sends keys to both the 'Creator' and the 'Viewer'.](4c1ea859b93043f2fa17a8fe72fb6176_img.jpg)
+
+```
+graph LR
+    Input(( )) --> Creator
+    subgraph KeyServer [Key server]
+        KS[Key server]
+    end
+    KS --> Creator
+    KS --> Viewer
+    Creator --> ProtectedImage[Protected image]
+    ProtectedImage --> Viewer
+    Viewer --> Output(( ))
+```
+
+Plain image
+
+Protected image
+
+Accepted image (e.g., thumbnail)
+
+T.807(23)\_FD.7
+
+Figure D.7: Overview of this technology. The diagram shows a workflow for image encryption and decryption. A 'Plain image' (a colorful bird) is input to a 'Creator' block. The 'Creator' outputs a 'Protected image' (a blurred, grayscale version of the bird). The 'Protected image' is input to a 'Viewer' block. The 'Viewer' outputs an 'Accepted image (e.g., thumbnail)' (a small, clear version of the bird). A 'Key server' block is connected to the 'Creator' and the 'Viewer'. The 'Key server' receives 'Granted resolution, quality, and/or region' as input. The 'Key server' sends keys to both the 'Creator' and the 'Viewer'.
+
+Figure D.7 – Overview of this technology
+
+As shown in Figure D.7, in the encryption stage, a key server generates a master key, and then, a creator encrypts an image using packet keys which are generated from the master key. In the decryption stage, a key server generates an access key according to granted resolution, quality, and/or region. Then, a viewer decrypts the encrypted image using packet keys which are generated from the access key. Note that these keys are sequentially generated based on secure hash chain.
+
+Specifically, this technology uses the following access control policy: "if a user can access to a resolution level/layer, then that user can also access to the lower resolution levels/layers". On the other hand, even if a user can access to a tile, that user cannot access to the other tiles at all.
+
+The significant advantage of this technology is that the number of keys needed to pass on from a key server to a viewer is much less than the conventional case. This means that this technology allows for smaller overhead in terms of storage usage.
+
+D.6.5 Signalling method
+
+Table D.14 shows recommended parameters in this technology. Any parameters are signalled according to the syntax which is identified in this Recommendation | International Standard. Especially, this tool should use "decryption" template, "packet" granularity, and "bitstream" processing domain with the appropriate ZOI.
+
+Table D.14 – Recommended parameter in this technology
+
+| Parameter        |                       | Size (bits) | Values           | Meaning                                                    |
+|------------------|-----------------------|-------------|------------------|------------------------------------------------------------|
+| SEC              |                       | 16          | 0xFF65           | SEC marker                                                 |
+| LSEC             |                       | 16          | 0 ... 255        | Length of SEC marker segment                               |
+| ZSEC             |                       | 8           | 0                | Index of this SEC marker segment                           |
+| PSEC             |                       | 1           | 0                | FBAS byte does not follow                                  |
+|                  | F <sub>INSEC</sub>    | 1           | 1                | INSEC is used                                              |
+|                  | F <sub>multiSEC</sub> | 1           | 0 <sub>b</sub>   | One SEC marker segment is used                             |
+|                  | F <sub>mod</sub>      | 1           | 1 <sub>b</sub>   | Original JPEG 2000 data was modified                       |
+|                  | F <sub>TRLCP</sub>    | 1           | 0 <sub>b</sub>   | TRLCP tag usage is not defined                             |
+|                  | Padding               | 3           | 000 <sub>b</sub> | Not used                                                   |
+|                  | N <sub>tools</sub>    | 8 (RBAS)    | 1                | Number of security tool is one                             |
+|                  | I <sub>max</sub>      | 8 (RBAS)    | 0                | Maximum tool instance index is zero                        |
+| t                |                       | 8 (RBAS)    | 1                | JPSEC non-normative tool                                   |
+| i                |                       | 8 (RBAS)    | 0                | Instance index for this tool                               |
+| ID <sub>RA</sub> | ID <sub>RA,id</sub>   | 32          | 5                | Registered ID for this tool                                |
+|                  | ID <sub>RA,nsI</sub>  | 8 (RBAS)    | 21               | The length of ID <sub>RA,ns</sub> in bytes                 |
+|                  | ID <sub>RA,ns</sub>   | 168         | <i>namespace</i> | The namespace of the RA with which this tool is registered |
+| L <sub>zoi</sub> |                       | 16          | Variable         | Length of ZOI for this tool                                |
+| ZOI              |                       | Variable    | <i>ZOI value</i> | Zone of Influence for this tool                            |
+| L <sub>PID</sub> |                       | 16          | Variable         | Length of L + T + PD + G                                   |
+
+Table D.14 – Recommended parameter in this technology
+
+| Parameter       | Size (bits) | Values         | Meaning                        |
+|-----------------|-------------|----------------|--------------------------------|
+| P <sub>ID</sub> | Variable    | See Table D.16 | Parameters for this technology |
+
+Table D.15 – Example ZOI of this key generation tool
+
+| Parameter         |                   |                   | Size (bits) | Value (in order)       | Derived meaning                                                 |
+|-------------------|-------------------|-------------------|-------------|------------------------|-----------------------------------------------------------------|
+| NDzoi             |                   |                   | 8           | 1                      | Number of Zones is one                                          |
+| Zone <sup>0</sup> | Dzoi              |                   | 1           | 0 <sub>b</sub>         | The byte aligned segment does not follow                        |
+|                   |                   |                   | 1           | 0 <sub>b</sub>         | Image related description class                                 |
+|                   |                   |                   | 6           | 101000 <sub>b</sub>    | Image regions and resolution levels are specified in order      |
+|                   | Pzoi <sup>1</sup> | Mzoi <sup>1</sup> | 1           | 0 <sub>b</sub>         | The byte aligned segment does not follow                        |
+|                   |                   |                   | 1           | 0 <sub>b</sub>         | The specified zones are influenced by the protection method     |
+|                   |                   |                   | 1           | 0 <sub>b</sub>         | Single item is specified                                        |
+|                   |                   |                   | 2           | 00 <sub>b</sub>        | Rectangle mode                                                  |
+|                   |                   |                   | 2           | 00 <sub>b</sub>        | Izoi uses 8-bit integer                                         |
+|                   |                   |                   | 1           | 1 <sub>b</sub>         | Izoi is described in two dimensions                             |
+|                   |                   | Izoi <sup>1</sup> | 8           | 0110 0100 <sub>b</sub> | Xul is 100                                                      |
+|                   |                   |                   | 8           | 0111 1000 <sub>b</sub> | Yul is 120                                                      |
+|                   |                   |                   | 8           | 1011 0100 <sub>b</sub> | Xlr is 180                                                      |
+|                   |                   |                   | 8           | 1101 0010 <sub>b</sub> | Ylr is 210                                                      |
+|                   | Pzoi <sup>3</sup> | Mzoi <sup>3</sup> | 1           | 0 <sub>b</sub>         | The byte aligned segment does not follow                        |
+|                   |                   |                   | 1           | 1 <sub>b</sub>         | The specified zones are not influenced by the protection method |
+|                   |                   |                   | 1           | 0 <sub>b</sub>         | Single item is specified                                        |
+|                   |                   |                   | 2           | 11 <sub>b</sub>        | Max mode                                                        |
+|                   |                   |                   | 2           | 00 <sub>b</sub>        | Izoi uses 8-bit integer                                         |
+|                   |                   |                   | 1           | 0 <sub>b</sub>         | Izoi is described in one dimension                              |
+|                   |                   | Izoi <sup>3</sup> | 8           | 0000 0010 <sub>b</sub> | Resolution levels > 3 are specified                             |
+
+Table D.16 – P<sub>ID</sub> for this technology
+
+| Parameter          |    | Size (bits) | Values                             | Meaning                                                                            |
+|--------------------|----|-------------|------------------------------------|------------------------------------------------------------------------------------|
+| T                  |    | Variable    | See Table D.17                     | Decryption templates                                                               |
+| PD                 |    | 8           | 0000 1000 <sub>b</sub>             | FBAS byte does not follow. Processed in codestream domain.                         |
+| G                  | PO | 16          | 0 000 001 010 011 100 <sub>b</sub> | Processing order is tile-resolution-layer-component-precinct                       |
+|                    | GL | 8           | 0000 0110 <sub>b</sub>             | Unit of protection is packet                                                       |
+| H                  |    | 16          | See Table 37 in 5.8.3.1            | Hash function for this key generation tool                                         |
+| L <sub>k</sub>     |    | 8           | 0 ... 255                          | Length of access key information                                                   |
+| AK <sub>info</sub> |    | Variable    | <i>Access key value</i>            | Access key information (this information is encrypted using KT <sub>bc</sub> in T) |
+
+Table D.17 – Example of decryption template of this technology
+
+| Parameter           |                   | Size (bits) | Value (in order)     | Derived meaning                          |
+|---------------------|-------------------|-------------|----------------------|------------------------------------------|
+| ME <sub>decry</sub> |                   | 8           | 1                    | Marker emulation has not occurred        |
+| CT <sub>decry</sub> |                   | 16          | 3                    | Block cipher (AES)                       |
+| CP <sub>decry</sub> | M <sub>bc</sub>   | 6           | 10 0010              | OFB mode is used. (Bits are not padded.) |
+|                     | SIZ <sub>bc</sub> | 16          | 128                  | Block size (128 bits)                    |
+|                     | KT <sub>bc</sub>  | Variable    | See 5.8.5            | Key template                             |
+|                     | IV <sub>sc</sub>  | 128         | Initial vector value | Initial vector value                     |
+
+D.6.6 Conclusion
+
+This clause described an image related access control technology for a JPEG 2000 codestream. The significant advantage of this technology is that the number of keys to be managed and to be accessed is much less than the conventional case.
+
+D.7 Wavelet and bitstream domain scrambling for conditional access control
+
+D.7.1 Summary
+
+Access control to an image is an important functionality in secure imaging. Often it is desirable to give access to a small resolution thumbnail or a low quality image, while access to higher resolutions or qualities are subject to authorization. In this clause, a technique for conditional access control is presented. The method was initially presented in [19]. Basically, it adds pseudo-random noise to the image. Authorized users know the pseudo-random sequence and thus can remove this noise. On the other hand, unauthorized users only have access to severely distorted images. The system is composed of three main components: scrambling, pseudo-random number generator and encryption algorithm. In order to fully exploit and retain the properties of JPEG 2000, the scrambling is selectively applied on the code-blocks composing the codestream. Consequently, the distortion level introduced in specific parts of the image can be controlled. This enables access control by resolution, quality or regions of interest in an image.
+
+D.7.2 Technical overview
+
+The system is composed of three main components:
+
+- Scrambling: two approaches are supported. The scrambling is either performed on the quantized wavelet coefficients, or directly on the bits in the codestream. In the first case, the signs of the coefficients in each code-block are inverted pseudo-randomly. In the second case, the bits of the codestream are pseudo-randomly inverted.
+- Pseudo-random number generator (PRNG): the PRNG is used to drive the scrambling. It is based on a seed value. In a preferred embodiment of the technique, the SHA1PRNG algorithm [14] with a 64-bit seed is used for the pseudo-random number generator (PRNG). Note that other PRNG algorithms could be used as well.
+- Encryption algorithm: to communicate the seeds to authorized users, they are encrypted and inserted in the codestream. In a preferred embodiment of the technique, the RSA algorithm is used for encryption [20]. Other encryption algorithms could be used as well. The length of the key can be selected at the time the image is protected.
+
+Figures D.8 and D.9 correspond to the two cases of wavelet and bitstream domain scrambling.
+
+![Block diagram for wavelet domain scrambling. The process starts with a 'Seed' input to an 'Encryption' block and a 'PRNG' block. The 'Encryption' block outputs an 'Encrypted seed' to a 'JPSEC syntax' block. The 'PRNG' block outputs to a 'Selective scrambling' block. The main data flow is: 'Wavelet transform' -> 'Quantizer' -> 'Selective scrambling' -> 'Arithmetic coder'. The 'Arithmetic coder' outputs a 'Scrambled codestream' to the 'JPSEC syntax' block. Finally, the 'JPSEC syntax' block outputs the 'JPSEC codestream'.](aec32fe54f8d88d7a631e4cb8d76e70d_img.jpg)
+
+```
+graph LR; Seed --> Encryption; Seed --> PRNG; Encryption -- "Encrypted seed" --> JPSEC_syntax[JPSEC syntax]; PRNG --> Selective_scrambling[Selective scrambling]; WT[Wavelet transform] --> Quantizer; Quantizer --> Selective_scrambling; Selective_scrambling --> AC[Arithmetic coder]; AC -- "Scrambled codestream" --> JPSEC_syntax; JPSEC_syntax --> JPSEC_codestream[JPSEC codestream];
+```
+
+Block diagram for wavelet domain scrambling. The process starts with a 'Seed' input to an 'Encryption' block and a 'PRNG' block. The 'Encryption' block outputs an 'Encrypted seed' to a 'JPSEC syntax' block. The 'PRNG' block outputs to a 'Selective scrambling' block. The main data flow is: 'Wavelet transform' -> 'Quantizer' -> 'Selective scrambling' -> 'Arithmetic coder'. The 'Arithmetic coder' outputs a 'Scrambled codestream' to the 'JPSEC syntax' block. Finally, the 'JPSEC syntax' block outputs the 'JPSEC codestream'.
+
+T.807(23)\_FD.8
+
+Figure D.8 – Block diagram for wavelet domain scrambling
+
+![Block diagram for bitstream domain scrambling. A 'Seed' input goes to an 'Encryption' block and a 'PRNG' block. The 'PRNG' block outputs to a 'Selective scrambling' block. The 'Selective scrambling' block takes a 'Codestream' as input and outputs a 'Scrambled codestream'. The 'Scrambled codestream' goes to a 'JPSEC syntax' block. The 'JPSEC syntax' block also receives an 'Encrypted seed' from an 'Encryption' block (which takes the 'Seed' as input). The 'JPSEC syntax' block outputs the 'JPSEC codestream'.](c19f37cdfc7768db716bfc0cc5934cfb_img.jpg)
+
+```
+graph TD
+    Seed --> PRNG
+    Seed --> Enc1[Encryption]
+    PRNG --> SS[Selective scrambling]
+    Codestream --> SS
+    SS --> SC[Scrambled codestream]
+    SC --> JPS[JPSEC syntax]
+    Enc1 --> ES[Encrypted seed]
+    ES --> JPS
+    JPS --> JPC[JPSEC codestream]
+```
+
+T.807(23)\_FD.9
+
+Block diagram for bitstream domain scrambling. A 'Seed' input goes to an 'Encryption' block and a 'PRNG' block. The 'PRNG' block outputs to a 'Selective scrambling' block. The 'Selective scrambling' block takes a 'Codestream' as input and outputs a 'Scrambled codestream'. The 'Scrambled codestream' goes to a 'JPSEC syntax' block. The 'JPSEC syntax' block also receives an 'Encrypted seed' from an 'Encryption' block (which takes the 'Seed' as input). The 'JPSEC syntax' block outputs the 'JPSEC codestream'.
+
+Figure D.9 – Block diagram for bitstream domain scrambling
+
+In order to improve the security of the system, the seed can be changed from one code-block to another. Also, several levels of access can be defined, using different encryption keys. The syntax given below is very flexible and supports the usage of multiple seeds and multiple keys.
+
+### D.7.3 Codestream syntax
+
+In this example, both the SEC and INSEC marker segments are used. The codestream syntax is defined below. The SEC marker segment is using the tool syntax for non-normative tools. The INSEC marker segment is used to signal which codeblocks are scrambled and which seeds are used.
+
+#### D.7.3.1 Syntax for SEC marker segment
+
+The tool syntax for non-normative tools is used. In the case of multiple keys, several instances of the tool are used in the SEC marker segment. More specifically, several instances  $T_{idx} = 0, 1, 2, \dots$  with the same ID are present, each one corresponding to a different key identification  $KeyID^{(i)}$ . This is illustrated below. See Figure D.10.
+
+![Diagram showing the syntax for SEC marker segment with multiple keys. It consists of three rows representing different instances (i=0, i=1, i=2). Each row has fields: 't', 'i', 'ID_RA', 'L_ZOI^{(i)}', 'ZOI^{(i)}', 'L_PID^{(i)}', 'N_S^{(i)}', 'KeyID^{(i)}', and 'Data'. The 'Data' field and several others are shaded with diagonal lines.](27f9c45d41672d72c3cc3c2ea386ebbb_img.jpg)
+
+```
+graph LR
+    subgraph i=0
+        t0[t] --- i0[i=0] --- ID_RA0[ID_RA] --- L_ZOI0[L_ZOI^{(0)}] --- ZOI0[ZOI^{(0)}] --- L_PID0[L_PID^{(0)}] --- NS0[N_S^{(0)}] --- KeyID0[KeyID^{(0)}] --- Data0[Data]
+    end
+    subgraph i=1
+        t1[t] --- i1[i=1] --- ID_RA1[ID_RA] --- L_ZOI1[L_ZOI^{(1)}] --- ZOI1[ZOI^{(1)}] --- L_PID1[L_PID^{(1)}] --- NS1[N_S^{(1)}] --- KeyID1[KeyID^{(1)}] --- Data1[Data]
+    end
+    subgraph i=2
+        t2[t] --- i2[i=2] --- ID_RA2[ID_RA] --- L_ZOI2[L_ZOI^{(2)}] --- ZOI2[ZOI^{(2)}] --- L_PID2[L_PID^{(2)}] --- NS2[N_S^{(2)}] --- KeyID2[KeyID^{(2)}] --- Data2[Data]
+    end
+```
+
+T.807(23)\_FD.10
+
+Diagram showing the syntax for SEC marker segment with multiple keys. It consists of three rows representing different instances (i=0, i=1, i=2). Each row has fields: 't', 'i', 'ID\_RA', 'L\_ZOI^{(i)}', 'ZOI^{(i)}', 'L\_PID^{(i)}', 'N\_S^{(i)}', 'KeyID^{(i)}', and 'Data'. The 'Data' field and several others are shaded with diagonal lines.
+
+Figure D.10 – Non-normative protection tool syntax in the case of multiple keys
+
+With the following semantic for  $P_{ID}$ :
+
+Table D.18 – Syntax and semantic for  $P_{ID}$
+
+| Parameters | Size (in bits) | Meaning                                             |
+|------------|----------------|-----------------------------------------------------|
+| $N_s$      | 16             | The number of seeds used by this instance           |
+| KeyID      | 32             | Identification of the key to be used for decrypting |
+| Data       | Variable       | The encrypted seeds                                 |
+
+#### D.7.3.2 Syntax for INSEC marker segment
+
+To include the information of which seed is used to protect which codeblocks, the in-codestream security marker (INSEC) is also used. In this example, it is added before the secured codeblock(s), to indicate which seed has been used to protect this/these codeblock(s). Instead of indicating the seed itself, the marker contains an index which refers to the seeds in the main header SEC marker segment. As in this example, the INSEC information applies to the following code-blocks, R is
+
+always equal to 1. As shown in Figure D.11, the syntax of AP is different in the case of wavelet scrambling and bitstream scrambling:
+
+![Figure D.11 – Syntax for AP. The left part shows Wavelet domain scrambling with a single box labeled S_idx. The right part shows Bitstream domain scrambling with two adjacent boxes: the first labeled Off and the second labeled S_idx.](88fa0e6558e55b5d54f4d3029b21aabb_img.jpg)
+
+T.807(23)\_FD.11
+
+Figure D.11 – Syntax for AP. The left part shows Wavelet domain scrambling with a single box labeled S\_idx. The right part shows Bitstream domain scrambling with two adjacent boxes: the first labeled Off and the second labeled S\_idx.
+
+**Figure D.11 – Syntax for AP: Wavelet domain scrambling (left), Bitstream domain scrambling (right)**
+
+With the following semantic:
+
+**Table D.19 – Syntax and semantic for AP**
+
+| Parameter        | Size (in bits) | Meaning                                                            |
+|------------------|----------------|--------------------------------------------------------------------|
+| Off              | 16             | The offset in the code-block bitstream of the first scrambled byte |
+| S <sub>idx</sub> | 16             | The seed index for the code-block                                  |
+
+In the case of multiple keys, the combination of the tool instance  $T_{idx}$  and the seed index  $S_{idx}$  uniquely identifies which seed/key this INSEC marker segment is referring to.
+
+**D.7.4 Conclusions**
+
+In this clause, a security tool was presented for conditional access control to JPEG 2000 images. The technique introduces a pseudo-random noise to selected parts of the codestream. Consequently, the decoded image appears much distorted for an unauthorized decoder which does not know how to remove this noise.
+
+The security of the technique depends on the security of the specific algorithms for pseudo-random number generator and encryption of the seed, in our preferred embodiment SHA1PRNG and RSA respectively. SHA1PRNG is a secure PRNG, as no knowledge of the sequence can be deduced by knowing some of the numbers in the sequence. In this example, the PRNG seed is 64 bits which should make a brute force attack unfeasible. The seeds are encrypted with RSA using a user-defined key length. RSA is regarded as a secure algorithm, provided a sufficient key length is used.
+
+**D.8 Progressive access for JPEG 2000 codestream**
+
+**D.8.1 Security services addressed**
+
+This method provides a non-image related access control for JPEG 2000 according to a progression order in a codestream.
+
+**D.8.2 Typical applications**
+
+A typical application of this technology is secure image distribution where only an authorized user can play the accepted image. Specifically, this technology is suitable for access control according to a progression order in a codestream.
+
+**D.8.3 Potential users, implementation model and motivations**
+
+The challenge in the design of the access control scheme is to strike a delicate balance among security, efficiency and flexibility. This access control technique for a JPEG 2000 codestream constructs a hash chain to generate the keys for each packet so as to encrypt packets in the codestream. Therefore, only users with the right security clearance can decrypt the packets corresponding to the granted image in the codestream.
+
+**D.8.4 Technical overview**
+
+As shown in Figure D.12, in the encryption stage, a key server generates a master key, and then, a creator encrypts a codestream using packet keys which are generated from the master key. In the decryption stage, a key server generates an access key according to granted packet. Then, a viewer decrypts the encrypted codestream using packet keys which are generated from the access key.
+
+Specifically, this technology uses the following access control policy: "if a user can access a packet, then that user can also access the preceding packets in a codestream". Therefore, such kind of access control is called "Progressive Access".
+
+The significant advantage of this technology is that the number of keys needed to pass on from a key server to a viewer is much less than the conventional case. This means that this technology allows for smaller overhead in terms of storage usage.
+
+![Figure D.12: Technical overview of this technology. The diagram shows a flow from a 'Granted packet' to a 'Key server'. The 'Key server' provides a 'Master key' to a 'Creator' and an 'Access key' to a 'Viewer'. The 'Creator' takes 'Plain codestream' as input and outputs 'Protected codestream'. The 'Viewer' takes 'Protected codestream' as input and outputs 'Accepted codestream'. A legend indicates that grey boxes represent 'Encrypted data' and white boxes represent 'Plain data'. The 'Accepted codestream' is shown as a combination of plain and encrypted data, with a 'Granted packet' pointing to the encrypted portion. Reference: T.807(23)_FD.12](2d548db0b26b7bf33244320322d5ee2c_img.jpg)
+
+Figure D.12: Technical overview of this technology. The diagram shows a flow from a 'Granted packet' to a 'Key server'. The 'Key server' provides a 'Master key' to a 'Creator' and an 'Access key' to a 'Viewer'. The 'Creator' takes 'Plain codestream' as input and outputs 'Protected codestream'. The 'Viewer' takes 'Protected codestream' as input and outputs 'Accepted codestream'. A legend indicates that grey boxes represent 'Encrypted data' and white boxes represent 'Plain data'. The 'Accepted codestream' is shown as a combination of plain and encrypted data, with a 'Granted packet' pointing to the encrypted portion. Reference: T.807(23)\_FD.12
+
+Figure D.12 – Technical overview of this technology
+
+D.8.5 Signalling method
+
+Table D.20 shows recommended parameters in this technology. Any parameters are signalled according to the syntax which is identified in this Recommendation | International Standard. Especially, this technology should use "decryption" template, "packet" granularity, and "bitstream" processing domain with the appropriate ZOI.
+
+Table D.20 – Example parameters for this tool
+
+| Parameter        |                       | Size (bits) | Values                   | Meaning                                                    |
+|------------------|-----------------------|-------------|--------------------------|------------------------------------------------------------|
+| SEC              |                       | 16          | 0xFF65                   | SEC marker                                                 |
+| L <sub>SEC</sub> |                       | 16          | Variable 0 ... 255       | Length of SEC marker segment                               |
+| Z <sub>SEC</sub> |                       | 8           | 0                        | Index of this SEC marker segment                           |
+| P <sub>SEC</sub> |                       | 1           | 0                        | FBAS byte does not follow                                  |
+|                  | F <sub>INSEC</sub>    | 1           | 1 <sub>b</sub>           | INSEC is used                                              |
+|                  | F <sub>multiSEC</sub> | 1           | 0 <sub>b</sub>           | One SEC marker segment is used                             |
+|                  | F <sub>mod</sub>      | 1           | 1 <sub>b</sub>           | Original JPEG 2000 data was modified                       |
+|                  | F <sub>TRLCP</sub>    | 1           | 0 <sub>b</sub>           | TRLCP tag usage is not defined                             |
+|                  | Padding               | 3           | 000 <sub>b</sub>         | Not used                                                   |
+|                  | N <sub>tools</sub>    | 8 (RBAS)    | 1                        | Number of security tools is one                            |
+|                  | I <sub>max</sub>      | 8 (RBAS)    | 0                        | Maximum tool instance index is zero                        |
+| t                |                       | 8 (RBAS)    | 1                        | RA protection tool                                         |
+| i                |                       | 8 (RBAS)    | 0                        | Instance index                                             |
+| ID <sub>RA</sub> | ID <sub>RA,id</sub>   | 32          | 7                        | Registered ID                                              |
+|                  | ID <sub>RA,nsI</sub>  | 8 (RBAS)    | 21                       | The length of ID <sub>RA,ns</sub> in bytes                 |
+|                  | ID <sub>RA,ns</sub>   | 168         | namespace                | The namespace of the RA with which this tool is registered |
+| L <sub>zoi</sub> |                       | 16 (RBAS)   | Variable                 | Length of ZOI                                              |
+| ZOI              |                       | Variable    | See Table D.21 (example) | Zone of Influence for this tool                            |
+| L <sub>PID</sub> |                       | 16 (RBAS)   | Variable                 | Length of L + T + PD + G                                   |
+| P <sub>ID</sub>  |                       | Variable    | See Table D.22 (example) | Parameters for this tool                                   |
+
+Table D.21 – Example ZOI of this technology
+
+| Parameter         |                    |                   | Size (bits) | Value (in order) | Derived meaning                                                 |
+|-------------------|--------------------|-------------------|-------------|------------------|-----------------------------------------------------------------|
+| NDzoi             |                    |                   | 8           | 1                | Number of Zones is one                                          |
+| Zone <sup>0</sup> | DCzoi              |                   | 1           | 0                | The byte aligned segment does not follow                        |
+|                   |                    |                   | 1           | 1                | Non-image related description class                             |
+|                   |                    |                   | 6           | 000100           | Packets are specified                                           |
+|                   | Pzoi <sup>4</sup>  | Mzoi <sup>4</sup> | 0           | 1                | The byte aligned segment does not follow                        |
+|                   |                    |                   | 1           | 1                | The specified zones are not influenced by the protection method |
+|                   |                    |                   | 1           | 1                | Multiple items are specified                                    |
+|                   |                    |                   | 11          | 2                | Max mode                                                        |
+|                   |                    |                   | 00          | 2                | Izoi uses 8-bit integer                                         |
+|                   |                    |                   | 00          | 2                | Izoi is described in one dimension                              |
+|                   |                    |                   |             |                  |                                                                 |
+|                   |                    |                   |             |                  |                                                                 |
+|                   | Izoi <sup>11</sup> |                   | 8           | 0000 1010        | Packet index > 10 is identified                                 |
+
+Table D.22 – P<sub>ID</sub> for this technology
+
+| Parameter          |    | Size (bits) | Values                             | Meaning                                                                            |
+|--------------------|----|-------------|------------------------------------|------------------------------------------------------------------------------------|
+| T                  |    | variable    | See Table D.23                     | Decryption templates                                                               |
+| PD                 |    | 8           | 0000 1000 <sub>b</sub>             | Subsequent BAS byte does not exist. Codestream domain.                             |
+| G                  | PO | 16          | 0 000 001 010 011 100 <sub>b</sub> | Processing order is tile-resolution-layer-component-precinct                       |
+|                    | GL | 8           | 0000 0110 <sub>b</sub>             | Unit of protection is packet                                                       |
+| H                  |    | 16          | See Table 37 in 5.8.3.1            | Hash function for this key generation tool                                         |
+| L <sub>k</sub>     |    | 8           | 0 ... 255                          | Length of access key information                                                   |
+| AK <sub>info</sub> |    | Variable    | <i>Access key value</i>            | Access key information (this information is encrypted using KT <sub>bc</sub> in T) |
+
+Table D.23 – Example of decryption template of this technology
+
+| Parameter           |                   | Size (bits) | Value (in order)            | Derived meaning                          |
+|---------------------|-------------------|-------------|-----------------------------|------------------------------------------|
+| ME <sub>decry</sub> |                   | 8           | 1                           | Marker emulation has not occurred        |
+| CT <sub>decry</sub> |                   | 16          | 3                           | Block cipher (AES)                       |
+| CP <sub>decry</sub> | M <sub>bc</sub>   | 6           | 10 0010                     | OFB mode is used. (Bits are not padded.) |
+|                     | SIZ <sub>bc</sub> | 16          | 128                         | Block size (128 bits)                    |
+|                     | KT <sub>bc</sub>  | Variable    | <i>Key template values</i>  | Key template                             |
+|                     | IV <sub>sc</sub>  | 128         | <i>Initial vector value</i> | Initial vector value                     |
+
+D.8.6 Conclusion
+
+This clause described an access control technology for a JPEG 2000 codestream. The significant advantage of this technology is that the number of keys to be managed and to be accessed is much less than the conventional case. This technology provides a flexible and efficient JPEG 2000 access control according to a progression over order in a codestream.
+
+D.9 Scalable authenticity of JPEG 2000 codestreams
+
+D.9.1 Security service
+
+This clause provides a flexible authentication mechanism for JPEG 2000 codestreams. It allows users to verify the authenticity and integrity of different sub-images with a single digital signature.
+
+D.9.2 Typical application
+
+In critical application fields such as government, finance, healthcare and law, clients normally demand authenticity of the received content. Accordingly, a scalable security mechanism for authenticating document is used in content dissemination.
+
+### D.9.3 Motivation
+
+In the third party publishing applications, an image producer generates a codestream and its signature. The producer then delivers the codestream and the signature to a third party publisher. The users can ask the publisher for a transcoded codestream due to resource limitation (e.g., bandwidth, computation). The publisher will deliver to the user the sub-image data as well as its authenticity proof.
+
+### D.9.4 Technical overview
+
+The scheme provides a flexible authentication mechanism for JPEG 2000 codestreams. It includes three modules: Signing, Transcoding and Verifying. The basic technology is the Merkle tree which organizes the JPEG 2000 packets.
+
+#### D.9.4.1 Signing module
+
+The signing module generates a signature on an input JPEG 2000 codestream according to preferred digital signature scheme. The protected codestream is produced by inserting a SEC marker into the original codestream. Specifically, the producer:
+
+- Reads a JPEG 2000 codestream.
+- Constructs a hash tree so as to produce the *root* value. The value of each leaf node is the hash of a packet. The value of each internal node is the hash of its child nodes. The tree structure is similar to the progress order of codestream.
+- Signs the *root* value of the hash tree with a private key based on a signature algorithm.
+- Creates the SEC parameters. Insert the parameters into the SEC segment so as to produce an authentic codestream.
+
+#### D.9.4.2 Transcoding module
+
+It generates Subsidiary Integrity Tokens (SITs) and a transcoded codestream based on the requested resolution, layer, component and region. The SEC of the new codestream includes the SITs and some other parameters. Specifically, the publisher and/or proxy:
+
+- Reads the discarded packets which are not included in the transcoded codestream.
+- Constructs the hash sub-trees with the discarded packets.
+- Inserts root values of the sub-trees into SEC segment.
+
+The transcoded codestream includes the updated SEC segment and codestream excluding the discarded packets.
+
+#### D.9.4.3 Verifying module
+
+The verifying module checks the authenticity of the protected codestream. According to preferred digital signature scheme, the verifier obtains the public key, then:
+
+- Reads the received codestream.
+- Constructs the hash tree with the received packets and codestream headers from bottom to top. If some packets are discarded, replaces the sub-tree with the corresponding SIT. Thus, the *root'* value is constructed.
+- Checks the *root'* value against the signature in the SEC segment based on the specific signature system. If it matches, the codestream is accepted; otherwise, reject the received packets.
+
+### D.9.5 Codestream syntax
+
+The SEC structure is shown in Figure D.13 and Table D.24. It includes the SEC marker, tool ID, and ZOI, the authentication template, and the security parameters for verification. The security parameters include data for recovering the codestream headers.
+
+![Diagram of the SEC structure showing fields: t, i, ID_RA, L_ZOI, ZOI_ID, ID_T, T, and TP_ID.](e7c92619d947e56ee7fa5d2ded3b40c1_img.jpg)
+
+The diagram illustrates the SEC structure as a sequence of fields. The first two fields are 't' and 'i'. The third field is 'ID<sub>RA</sub>' with diagonal hatching. The fourth field is 'L<sub>ZOI</sub>' with a vertical line above it. The fifth field is 'ZOI<sub>ID</sub>' with diagonal hatching. The sixth field is 'ID<sub>T</sub>'. The seventh field is 'T' with diagonal hatching. The eighth field is 'TP<sub>ID</sub>' with diagonal hatching. Below the diagram is the label 'T.807(23)\_FD.13'.
+
+Diagram of the SEC structure showing fields: t, i, ID\_RA, L\_ZOI, ZOI\_ID, ID\_T, T, and TP\_ID.
+
+Figure D.13 – Non-normative tool syntax
+
+Table D.24 – Non-normative tool parameters
+
+| Parameter         |                      | Size (bits) | Values                                | Semantic                                                   |
+|-------------------|----------------------|-------------|---------------------------------------|------------------------------------------------------------|
+| t                 |                      | 8 (RBAS)    | 1                                     | Non-normative tool syntax is used                          |
+| i                 |                      | 8 (RBAS)    | <i>Instance value</i>                 | Tool instance identifier                                   |
+| ID <sub>RA</sub>  | ID <sub>RA,id</sub>  | 32          | <i>ID value</i>                       | Registered ID                                              |
+|                   | ID <sub>RA,nsI</sub> | 8 (RBAS)    | 21                                    | The length of ID <sub>RA,ns</sub> in bytes                 |
+|                   | ID <sub>RA,ns</sub>  |             | <i>namespace</i>                      | The namespace of the RA with which this tool is registered |
+| L <sub>ZOI</sub>  |                      | 16          | [0 ... 2 <sup>16</sup> – 1]           | Length of parameters for ZOI                               |
+| ZOI <sub>ID</sub> |                      | Variable    | ZOI values                            | Zone parameters                                            |
+| L <sub>ID</sub>   |                      | 16          | [19 ... 2 <sup>16</sup> – 1]          | Length of parameters                                       |
+| ID <sub>T</sub>   |                      | 8           | 2                                     | Authentication template class id                           |
+| T                 |                      | Variable    | <i>Authentication template values</i> | Authentication/MAC Template                                |
+| TP <sub>ID</sub>  |                      | Variable    | See Table D.25                        | Security Parameters, see Figure D.14                       |
+
+![Diagram of Security parameters TP_ID syntax. It shows a sequence of fields: Hash Tree, L_SIT, SIT, L_SMH, SMH, L_STH, and STH. The fields SIT, SMH, and STH are shaded with diagonal lines. The label T.807(23)_FD.14 is at the bottom right.](9b39a1d27e49bccd8767e8d5fc0be7fd_img.jpg)
+
+T.807(23)\_FD.14
+
+Diagram of Security parameters TP\_ID syntax. It shows a sequence of fields: Hash Tree, L\_SIT, SIT, L\_SMH, SMH, L\_STH, and STH. The fields SIT, SMH, and STH are shaded with diagonal lines. The label T.807(23)\_FD.14 is at the bottom right.
+
+Figure D.14 – Security parameters TP<sub>ID</sub> syntax
+
+Table D.25 – Security parameters
+
+| Parameter                                                                                                                                                                                                                 | Size (bits)                                          | Values                      | Meaning                                                                                                                                                                            |
+|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------|-----------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| HashTree                                                                                                                                                                                                                  | 8                                                    | 0 ... (2 <sup>8</sup> – 1)  | Hash Tree order. It can be different from the codestream progression order. Tentatively,<br>0x00: LRCP<br>0x01: RLCP<br>0x02: RPCL<br>0x03: PCRL<br>0x04: CPRL<br>others: Reserved |
+| L <sub>SIT</sub>                                                                                                                                                                                                          | 16                                                   | 0 ... (2 <sup>16</sup> – 1) | Number of SITs                                                                                                                                                                     |
+| SIT                                                                                                                                                                                                                       | Variable: <i>L<sub>hash</sub></i> * L <sub>SIT</sub> | NaN                         | Subsidiary Integrity Token                                                                                                                                                         |
+| L <sub>SMH</sub>                                                                                                                                                                                                          | 16                                                   | 0 ... (2 <sup>16</sup> – 1) | length for SMH                                                                                                                                                                     |
+| SMH                                                                                                                                                                                                                       | Variable                                             |                             | Parameters for recovering main header                                                                                                                                              |
+| L <sub>STH</sub>                                                                                                                                                                                                          | 16                                                   | 0 ... (2 <sup>16</sup> – 1) | length for STH                                                                                                                                                                     |
+| STH                                                                                                                                                                                                                       | Variable                                             |                             | Parameters for recovering tile header                                                                                                                                              |
+| <div>a) For Keyed-MAC authentication, the (verification) key should be delivered separately.</div> <div>b) NaN: Not a Number.</div> <div>c) <i>L<sub>hash</sub></i> is the size of hash value, e.g., 160 for SHA-1.</div> |                                                      |                             |                                                                                                                                                                                    |
+
+D.9.6 Conclusion
+
+The technology provides a flexible authentication mechanism for JPEG 2000 codestream. It has the property of "sign once, verify many ways". Concretely, after an original JPEG 2000 codestream is signed once, various codestreams transcoded from the original codestream can be verified with trust on the producer only. This property perfectly matches the functionality of "compress once, decompress many ways". It is in contrast with the traditional image authentication method which allows one signature to authenticate only one image.
+
+D.10 JPEG 2000 data confidentiality and access control system based on data splitting and luring
+
+The described system in this clause is based on the splitting, through a process called *Data\_Splitting and Luring*, of an original JPEG 2000 file into two new files called respectively the *Lured\_jp2file*, which conveys a protected content, and the *Control\_File*, which conveys necessary information to access to the protected content. Only a real time combination
+
+of those two files, through the *Live\_Composing* process, allows for the rebuilding of the original JPEG 2000 file. The *Live\_Composing* is managed by access control rules and rights management. The described system provides a high level of robustness and flexibility in JPEG 2000 data confidentiality and access control and is based on low time consuming and low cost computational operations.
+
+### D.10.1 Operational description
+
+#### D.10.1.1 Security services addressed
+
+- Confidentiality: A Lured\_jp2file conveys a protected content. By decoding only a single Lured\_jp2file, the rendered content is visually scrambled, hence preventing an access to the original content. Only the real time recovering of the data stored in the Control\_File through the *Live\_Composing* Process enables an access to the original content.
+- Access Control: This system can be used to perform access control on image content: several users sharing the same Lured\_jp2file but owning different access rights will not be allowed to access to the same parts of the content.
+
+Note about IPR protection: by linking the content access with authentication and rights management, efficient control and tracking of the broadcasting and usage of a protected content can be ensured according to the content owner's will and prerogative, possibly by combining this system with watermarking or fingerprinting.
+
+#### D.10.1.2 Typical applications
+
+One of the key idea of the system described is the splitting of the initial JPEG 2000 into two files, the first (Lured\_jp2file) conveying only 99% of the original data and 1% of dummy data called lures and can be freely distributed, broadcasted, exchanged or copied through any classical networks or media, and the second one (Control\_File) conveying 1% of the original data plus some information which both are absolutely required to access to the protected content conveyed in the Lured\_jp2file.
+
+The other key idea is to link the access to the protected content conveyed in the Lured\_jp2file with an identification and rights management steps whose results will trigger the streaming of the needed information used to recover in real time only an unscrambled content.
+
+Finally, an efficient usage tracking and reporting is enabled through the statistics collected from the secured control\_files server logfiles.
+
+#### D.10.1.3 Potential users, implementation model and motivations
+
+The potential users of the described system are the content creators, owners and providers as the system ensures that once the content is protected and conveyed in a Lured\_jp2file, only authenticated and allowed users will be able to access to the original content. It is important to highlight that only 99% of the original content is provided freely, whereas the 1% needed to access to the original content will be distributed only after authentication and rights management protocols are passed.
+
+### D.10.2 Technical overview
+
+Figure D.15 shows an overview of the system.
+
+![Figure D.15 – System overview diagram showing the flow from an original JPEG 2000 file to a rendering device, including data splitting, luring, distribution, and live composing processes.](d665f520401064e5cfeed94d226f48bd_img.jpg)
+
+The diagram illustrates the system architecture for content protection and reconstruction. It starts with an 'Original JPEG 2000 file' (depicted as a small image of a person) entering a 'Data splitting and luring' block. A callout box from this block states: 'Generate: • a JPEG 2000 Part 1 compliant file, conveying a protected content • a Control\_File'. The process outputs two files: a 'Lured\_jp2 file' (depicted as a blurred image) and a 'Control file (1% of original codestream data)'. The 'Lured\_jp2 file' is shown being decoded into 'Decoded content' (a blurred image). The 'Control file' is stored in a 'Secured server of Control\_Files' (represented by a cylinder). A 'Free: Distribution exchange copy' cloud connects the 'Lured\_jp2 file' to 'Storage media' (Satellite, Cable, Internet) and a 'User'. The 'User' can then access the 'Lured\_jp2 file'. The 'Lured\_jp2 file' also enters a 'Live composing process' block, which is connected to a 'Live dialog' block. The 'Live dialog' block is connected to the 'Secured server of Control\_Files' via a 'Streamed control file' (indicated by a dashed line). A callout box from the 'Live dialog' block states: 'Identification and rights managements'. The 'Live composing process' block is connected to a 'Rendering device' block. A callout box from the 'Live composing process' block states: 'Real time JPEG 2000 file rebuilding'. The diagram is labeled 'T.807(23)\_FD.15' at the bottom right.
+
+Figure D.15 – System overview diagram showing the flow from an original JPEG 2000 file to a rendering device, including data splitting, luring, distribution, and live composing processes.
+
+Figure D.15 – System overview
+
+An input JPEG 2000 file is split into two new files through an operation called *Data Splitting and Luring*. Two new files are then generated: a *Lured\_jp2file*, conveying a protected content (JPSEC content) and a *Control\_File*.
+
+Through the Data Splitting and Luring process, some portions of the original JPEG 2000 file are extracted and replaced by *lures*. A *Lured\_jp2file* conveys about 99% of the original content whereas the last 1% are dummy data called lures, i.e., data without any *a priori* known link with the original data. Unlike to classical encryption, the luring process is not key based. A *Lured\_jp2file* can be freely distributed, exchanged or copied by any user. The *Control\_File* contains the 1% of original data extracted from the original file. It is stored in a *Secured Server of Control\_Files*.
+
+When the *Lured\_jp2file* is decoded by any JPEG 2000 Core coding system compliant decoder, the content appears visually scrambled. The only way to access to the original content is to recover the extracted original data thanks to the *Control\_File*. The *Live\_Composing* device connects to the Secure Server of Control\_Files through the *Live\_Dialog* protocol and an identification and rights management protocol occurs:
+
+- if the user owns the rights or agrees with the content access conditions (e.g., payment or subscription), the extracted data are retrieved from the *Control\_File* and the original JPEG 2000 file is recovered in real time. However, according to user's rights, the rebuilding of the original JPEG 2000 can be partial (for instance to only allow an access to a particular tile and/or colour component and/or resolution and/or precinct and/or quality layers) or full;
+- if the user does not own the rights or does not accept the conditions, only scrambled content is displayed.
+
+Main features of the described system are:
+
+- *Splitting of the original JPEG 2000 file* into two files, the first one conveying a protected JPEG 2000 content with only 99% of the original data plus 1% of dummy data called lures (*Lured\_jp2file*), the second one storing some original information data (1%) needed to rebuild the original JPEG 2000 content;
+- *Content visual scrambling*;
+- *JPEG 2000 Core coding system compliance and file size preserving*;
+- *Low bit-rate and low computational cost protection system*.
+
+The described system can be used with any environment and/or operating system. No particular hardware or software requirements are needed.
+
+The Luring process will insert the following SEC marker in the *Lured\_jp2file*:
+
+Table D.26 – Parameter values for this tool
+
+| Parameter                                     |                       |                                 |                               | Size (bits)          | Value (in order)            | Derived meaning                                                                   |  |
+|-----------------------------------------------|-----------------------|---------------------------------|-------------------------------|----------------------|-----------------------------|-----------------------------------------------------------------------------------|--|
+| SEC                                           |                       |                                 |                               | 16                   | 0xFF65                      | SEC marker                                                                        |  |
+| L <sub>SEC</sub>                              |                       |                                 |                               | 16                   | 0XXXXX                      | Length of the SEC marker segment                                                  |  |
+| Z <sub>SEC</sub>                              |                       |                                 |                               | 8                    | 1 ... 255                   | Index of the marker segment                                                       |  |
+| P <sub>SEC</sub><br>(if Z <sub>SEC</sub> = 1) | F <sub>INSEC</sub>    |                                 |                               | 1                    | 0                           | INSEC is not used                                                                 |  |
+|                                               | F <sub>multiSEC</sub> |                                 |                               | 1                    | 0                           | One SEC marker segment is used                                                    |  |
+|                                               | F <sub>J2K</sub>      |                                 |                               | 2                    | 1                           | JPSEC stream compliant with the JPEG 2000 Core coding system                      |  |
+|                                               | F <sub>TRLCP</sub>    |                                 |                               | 1                    | 0                           | TRLCP tag usage is not defined in this field                                      |  |
+|                                               | N <sub>tools</sub>    |                                 |                               | 7                    | 1                           | One security tool is used in the codestream                                       |  |
+|                                               | I <sub>max</sub>      |                                 |                               | 7                    | 1                           | Maximum tool instance index value used                                            |  |
+|                                               | Padding               |                                 |                               | 5                    | 0                           | Padding                                                                           |  |
+| Tool <sup>(0)</sup>                           | t                     |                                 |                               | 8 (RBAS)             | 1                           | Non-normative protection tool                                                     |  |
+|                                               | i                     |                                 |                               | 8 (RBAS)             | 0                           | Tool instance index                                                               |  |
+|                                               | ID <sub>RA</sub>      | ID <sub>RA,id</sub>             |                               | 32                   | ID                          | RA is used to deliver the ID number                                               |  |
+|                                               |                       | ID <sub>RA,nsI</sub>            |                               | 8 (RBAS)             | 21                          | Length of ID <sub>RA,ns</sub> is 21 bytes                                         |  |
+|                                               |                       | ID <sub>RA,ns</sub>             |                               | 168                  | namespace                   | The namespace of the RA with which this tool is registered                        |  |
+|                                               | L <sub>ZOI</sub>      |                                 |                               | 16                   | Length value                | Length of L <sub>ZOI</sub> + ZOI                                                  |  |
+|                                               | ZOI                   | NZ <sub>ZOI</sub>               |                               | 8                    | 0..254                      | Number of Zones                                                                   |  |
+|                                               |                       | Zone <sup>0</sup>               | DC <sub>ZOI</sub>             | 1                    | 0                           | The byte aligned segment does not follow                                          |  |
+|                                               |                       |                                 |                               | 1                    | 1                           | Non-image related description class                                               |  |
+|                                               |                       |                                 |                               | 6                    | 000010                      | Packet indexes are specified                                                      |  |
+|                                               |                       | P <sub>ZOI</sub> <sup>0,0</sup> | M <sub>ZOI</sub>              | 1                    | 0                           | The byte aligned segment does not follow                                          |  |
+|                                               |                       |                                 |                               | 1                    | 0                           | The specified zones are influenced by the protection method                       |  |
+|                                               |                       |                                 |                               | 1                    | 1                           | Multiple items are specified                                                      |  |
+|                                               |                       |                                 |                               | 2                    | 10                          | Index mode                                                                        |  |
+|                                               |                       |                                 |                               | 2                    | xx                          | I <sub>ZOI</sub> uses 8- or 16- or 32-bit integer                                 |  |
+|                                               |                       |                                 |                               | 1                    | 0                           | I <sub>ZOI</sub> is described in one dimension                                    |  |
+|                                               |                       |                                 |                               |                      |                             |                                                                                   |  |
+|                                               |                       |                                 | N <sub>ZOI</sub>              | 8                    | Variable                    | 2 ... 255 (number of packets indexes)                                             |  |
+|                                               |                       |                                 | I <sub>ZOI</sub> <sup>i</sup> | xxx N <sub>ZOI</sub> | variable                    | Packet index                                                                      |  |
+|                                               | L <sub>PID</sub>      |                                 |                               | 16                   | 0 ... (2 <sup>16</sup> – 1) | Length of L <sub>PID</sub> + P <sub>ID</sub> in Bytes                             |  |
+|                                               | P <sub>ID</sub>       |                                 |                               | Variable             | Variable                    | Control File ID, URL of Control File server, etc.; full syntax provided by the RA |  |
+
+## D.11 Secure scalable streaming and secure transcoding
+
+### D.11.1 Summary and motivation
+
+This clause describes a method for providing the protection services of confidentiality and authentication of JPEG 2000 codestreams in a manner that:
+
+- 1) allows a (potentially untrustworthy) entity to securely transcode or adapt JPSEC protected streams without requiring the entity to unprotect or decrypt the content; and
+- 2) allows a client to validate that the transcoding operation was performed in a valid and permissible manner.
+
+Transcoding is often required to adapt JPEG 2000 coded content for clients with diverse device capabilities (e.g., small display sizes or low-bit-rate network connections) and for time-varying network conditions. JPEG 2000 is especially well-suited for transcoding applications because of its inherent scalability properties. However, if one is not careful when protecting JPEG 2000 codestreams, the scalability property can be lost. For example, this occurs when the entire
+
+codestream is encrypted as a single file. In this case, the only way to transcode the protected codestream is to first decrypt it and then transcode or adapt the decrypted stream. Since the transcoder decrypts the content, this breaks the end-to-end security of the system.
+
+JPSEC was designed to enable secure transcoding of JPSEC-protected content, where secure transcoding is defined as *transcoding without unprotecting (decrypting) the content*. This is achieved with secure scalable streaming, which combines scalable coding, encryption, and signalling in a manner that allows low-complexity, secure transcoding by a (potentially untrusted) server or mid-network node or proxy. This enables JPSEC to achieve the seemingly conflicting properties of mid-network transcoding and end-to-end security. For example, in Figure D.16 media is encrypted at the sender and decrypted only at the receiver, and remains encrypted at all points in-between: (left) a mid-network node securely transcodes protected content for each JPSEC client, (right) an untrusted server securely transcodes and streams JPSEC content without unprotecting it.
+
+![Figure D.16: JPSEC enables end-to-end security and mid-network secure transcoding. The diagram illustrates two scenarios. In the top scenario, a Sender (Server) sends content to a 'Possibly untrusted?' node (Secure transcoding) which then streams to Desktop PC, Note PC, and Smart phone. In the bottom scenario, Protected content is stored in a Storage unit, accessed by an Untrusted server, which then streams to a Note PC and a Smart phone. Both scenarios maintain end-to-end security.](72d448a65347c51989171748789c7d4b_img.jpg)
+
+The diagram illustrates two scenarios of JPSEC-enabled secure transcoding and end-to-end security.
+
+**Top Scenario:** A Sender (Server) sends content to a "Possibly untrusted?" node labeled "Secure transcoding". This node streams content to three clients: Desktop PC (High BW), Note PC (Med BW), and Smart phone (Low BW). A double-headed arrow labeled "End-to-end security" spans from the Sender to the clients. A red 'X' over a key icon is shown above the transcoding node, indicating that decryption does not occur there.
+
+**Bottom Scenario:** Protected content is stored in a "Storage" unit. An "Untrusted server" (marked with a red 'X' over a key icon) accesses the content and streams it to a Note PC and a Smart phone.
+
+The identifier T.807(23)\_FD.16 is located at the bottom right of the diagram.
+
+Figure D.16: JPSEC enables end-to-end security and mid-network secure transcoding. The diagram illustrates two scenarios. In the top scenario, a Sender (Server) sends content to a 'Possibly untrusted?' node (Secure transcoding) which then streams to Desktop PC, Note PC, and Smart phone. In the bottom scenario, Protected content is stored in a Storage unit, accessed by an Untrusted server, which then streams to a Note PC and a Smart phone. Both scenarios maintain end-to-end security.
+
+**Figure D.16 – JPSEC enables end-to-end security and mid-network secure transcoding**
+
+### D.11.2 Operational description and two example usages
+
+In the first example, the original JPEG 2000 codestream is in RLCP ordering and the goal is to protect this stream with encryption and authentication while enabling secure transcoding by resolution on the protected codestream. Since the original JPEG 2000 codestream used an RLCP ordering, each resolution component is represented by a contiguous data segment. Encryption can be performed on each of the three contiguous data segments. The JPSEC header then specifies three zones of influence describing the resolution component, codestream segment, and encryption template used for each segment. Authentication is also performed on each of the three data segments, either before or after encryption depending on the desired functionality. This is also specified in the SEC header using the authentication template.
+
+In order to perform secure transcoding on the JPSEC codestream, a transcoder simply reads and parses the SEC header, identifies the locations of the resolution segments, and then retains or removes the appropriate data segments/resolutions. Notice that this transcoding operation corresponds to a simple parsing operation and that it does not require unprotecting the data. Authentication is performed by authenticating the received transcoded data with the MAC values that are placed in the SEC header during the JPSEC protection process.
+
+In the second example, the desired goal is once again to protect the codestream while allowing transcoding by resolution; however, this example is slightly more complex in that the original JPEG 2000 codestream is in PCRL rather than RLCP ordering, so the data segments corresponding to the three resolution components are not contiguous in the original
+
+codestream. JPSEC allows the desired goal of secure transcoding or scaling by resolution to be achieved in a number of ways. One method is to encrypt by individual packets while leaving packet headers unencrypted. This retains the highest level of scalability in the stream but also requires the most complex secure transcoding operation because the transcoder parses the JPSEC stream at the packet level. The other extreme that results in the simplest secure transcoding operation is to reorder the data such that the resolution components are once again in contiguous segments whose offsets are signalled in the SEC header. This can be achieved in a JPEG 2000 compliant manner by reordering the JPEG 2000 packets from PCRL to RLCP ordering and signalling the new progression order in the COD marker segment or with the progression order change (POC) marker segment. The resulting data reordering and protection transformation is shown in Figure D.17. Once again, the main SEC header contains ZOI parameters that describe the corresponding image-related and bitstream-related parameters associated with each data segment, but this time on the reordered JPEG 2000 codestream.
+
+![Figure D.17: An example of forming a JPSEC codestream. The diagram illustrates the transformation from a standard JPEG-2000 codestream to a JPSEC codestream through reordering and protection.](65b5e4a95d403df0ea5e8ff94f162a6a_img.jpg)
+
+The diagram illustrates the process of forming a JPSEC codestream from a standard JPEG-2000 codestream. It is divided into three main stages: **JPEG-2000**, **Reorder**, and **Protect**, leading to the final **JPSEC** codestream.
+
+- JPEG-2000:** The initial codestream structure consists of a header (SOC, SIZ, COD, QCD, SOT, SOD) followed by a large **DATA** segment and an EOC marker. The **DATA** segment is composed of multiple resolution components (R0, R1, R2) for each color channel (C0, C1, C2). For example, the R0 component contains packets P0 C0 R0, P0 C1 R0, P0 C2 R0, ..., Pn C2 R0.
+- Reorder:** The data segments are reordered so that packets of the same resolution level are grouped together. For instance, all R0 packets (P0 C0 R0, P0 C1 R0, P0 C2 R0, ..., Pn C2 R0) are moved to the top, followed by all R1 packets (P0 C0 R1, P0 C1 R1, P0 C2 R1, ..., Pn C2 R1), and then all R2 packets (P0 C0 R2, P0 C1 R2, P0 C2 R2, ..., Pn C2 R2).
+- Protect:** The reordered data is then protected (encrypted) for each resolution level. The **Protect** stage is indicated by dashed arrows and labels like 'Res 0', 'Res 1', and 'Res 2' pointing to the respective resolution groups.
+- JPSEC:** The final JPSEC codestream structure is identical to the JPEG-2000 header (SOC, SIZ, COD, QCD, SOT, SOD) and EOC, but the **DATA** segment now contains the protected, reordered packets in their original order (R0, then R1, then R2).
+
+Source: T.807(23)\_FD.17
+
+Figure D.17: An example of forming a JPSEC codestream. The diagram illustrates the transformation from a standard JPEG-2000 codestream to a JPSEC codestream through reordering and protection.
+
+Figure D.17 – An example of forming a JPSEC codestream
+
+### D.11.3 Codestream syntax
+
+The JPSEC syntax can be used to create a secure scalable streaming and secure transcoding system with the template protection tool. Specifically, the Zone of Influence (ZOI) can be used with the decryption template, processing domain, and granularity to fully define the decryption process that an allowed JPSEC consumer should use to decrypt the stream. Furthermore, the ZOI parameters signal information that transcoding nodes can use to perform secure transcoding.
+
+The ZOI specifies three zones, one for each resolution, and the byte ranges associated with the encrypted bits for each zone. The signalling syntax for the decryption protection template, processing domain, and granularity are shown in Table D.27. The decryption method is signalled with the decryption protection template. In this case, it specifies AES encryption in CTR mode, and the block size and key length. The processing domain and granularity further specify how the decryption is performed. It signals that the processing domain is the bitstream itself, and that packet headers and packet bodies are encrypted. Different decryption methods can be specified by changing the processing domain and granularity. For example, the granularity of the encryption can be on individual packets or only on the packet bodies. Furthermore, the authentication method is specified with the same ZOI as above, but with the following authentication template. The syntax for the authentication template is shown in Table D.28 for using HMAC with SHA-1 for authentication. Of course, other JPSEC ciphers and MACs can also be used. In addition, the proposed solution can be used with other digital signature, access control, and key management tools. Furthermore, a distortion can be associated with each packet (or other zone of data) using the distortion field (see 5.7.3.2) to enable rate-distortion (R-D) optimized secure streaming and secure transcoding [21], [22] and [23].
+
+**Table D.27 – Parameter values for template protection tool, processing domain and granularity**
+
+| Parameter          |                     | Size (bits)       | Value (in order)                  | Derived meaning                                 |  |
+|--------------------|---------------------|-------------------|-----------------------------------|-------------------------------------------------|--|
+| T <sub>decry</sub> | ME <sub>decry</sub> | 8                 | 0                                 | Marker emulation flag is NULL                   |  |
+|                    | CT <sub>decry</sub> | 16                | 1                                 | AES encryption                                  |  |
+|                    | CP <sub>decry</sub> | M <sub>bc</sub>   | 10 0101 <sub>b</sub>              | CTR and no padding                              |  |
+|                    |                     | P <sub>bc</sub>   | 0                                 | Padding is not used for CTR mode                |  |
+|                    |                     | SIZ <sub>bc</sub> | 128                               | Block size is 128 bits                          |  |
+|                    |                     | KT <sub>bc</sub>  | Variable                          | Key information template                        |  |
+| PD                 |                     | 1                 | 0 <sub>b</sub>                    | Byte aligned segment (BAS) does not follow      |  |
+|                    |                     | 1                 | 0 <sub>b</sub>                    | Not in pixel domain                             |  |
+|                    |                     | 1                 | 0 <sub>b</sub>                    | Not in wavelet coefficient domain               |  |
+|                    |                     | 1                 | 0 <sub>b</sub>                    | Not in quantized wavelet coefficient domain     |  |
+|                    |                     | 1                 | 1 <sub>b</sub>                    | Processed in codestream domain                  |  |
+|                    |                     | 3                 | 000 <sub>b</sub>                  | Not used                                        |  |
+| G                  | PO                  | 16                | 0 0000 0101 0011 100 <sub>b</sub> | Processing order is TRLCp                       |  |
+|                    | GL                  | 8                 | 0000 1001 <sub>b</sub>            | Granularity is total area identified by the ZOI |  |
+| V                  | N <sub>v</sub>      | 16                | 1                                 | One value is specified                          |  |
+|                    | S <sub>v</sub>      | 8                 | 16                                | Size is 16 bytes                                |  |
+|                    | VL                  | 128               | Nonce value                       | Counter value for CTR mode                      |  |
+
+**Table D.28 – Parameter values for authentication template protection tool**
+
+| Parameter         |                   | Size (bits)         | Value (in order) | Derived meaning                          |
+|-------------------|-------------------|---------------------|------------------|------------------------------------------|
+| T <sub>auth</sub> | M <sub>auth</sub> | 8                   | 0                | Hash-based MAC                           |
+|                   | P <sub>auth</sub> | M <sub>HMAC</sub>   | 8                | HMAC                                     |
+|                   |                   | H <sub>HMAC</sub>   | 8                | Hash ID is SHA-1                         |
+|                   |                   | KT <sub>HMAC</sub>  | Variable         | See key template                         |
+|                   |                   | SIZ <sub>HMAC</sub> | 16               | MAC size is 80 bits (truncated from 160) |
+
+**D.11.4 Conclusions**
+
+This clause describes secure scalable streaming and secure transcoding with JPSEC, which enables the two seemingly conflicting properties of end-to-end security with secure transcoding at mid-network nodes. This allows the JPSEC codestream to be transcoded *without requiring decryption*. Furthermore, this method provides authentication that the transcoding was performed only in a valid and permissible manner, and no unintentional or malicious modification from an error or attacker has occurred. This allows a (potentially untrustworthy) server or mid-network node such as a proxy to perform secure transcoding while allowing a JPSEC consumer to authenticate that the received content was transcoded in a valid and permissible manner.
+
+## Bibliography
+
+- [1] Recommendation ITU-T T.802 | ISO/IEC 15444-3, *Information technology – JPEG 2000 image coding system: Motion JPEG 2000*.
+- [2] Recommendation ITU-T T.805 | ISO/IEC 15444-6, *Information technology – JPEG 2000 image coding system: Compound image file format*.
+- [3] Recommendation ITU-T T.810 | ISO/IEC 15444-11, *Information technology – JPEG 2000 image coding system: Wireless*.
+- [4] ISO/IEC 9797-1:2011, *Information technology – Security techniques – Message Authentication Codes (MACs) – Part 1: Mechanisms using a block cipher*.
+- [5] ISO/IEC 9797-2:2021, *Information security — Message authentication codes (MACs) – Part 2: Mechanisms using a dedicated hash-function*.
+- [6] ISO/IEC 10118-3:2018, *Information technology – Security techniques – Hash-functions – Part 3: Dedicated hash-functions*.
+- [7] ISO/IEC 10118-4:1998, *Information technology – Security techniques – Hash-functions – Part 4: Hash-functions using modular arithmetic*.
+- [8] ISO/IEC 11770-(all parts), *Information technology – Security techniques – Key management*.
+- [9] ISO/IEC 14888-2:2008, *Information technology – Security techniques – Digital signatures with appendix – Part 2: Integer factorization based mechanisms*.
+- [10] ISO/IEC 14888-3:2018, *Information technology – Security techniques – Digital signatures with appendix – Part 3: Certificate-based mechanisms*.
+- [11] ISO/IEC 18033-2:2006, *Information technology – Security techniques – Encryption algorithms – Part 2: Asymmetric ciphers*.
+- [12] ISO/IEC 18033-3:2010, *Information technology – Security techniques – Encryption algorithms – Part 3: Block ciphers*.
+- [13] ISO/IEC 18033-4:2011, *Information technology – Security techniques – Encryption algorithms – Part 4: Stream ciphers*.
+- [14] frohoff / jdk8u-jdk on GitHub public archive, <https://github.com/frohoff/jdk8u-jdk/blob/master/src/share/classes/sun/security/provider/SecureRandom.java>, (visited on 2023-02-28).
+- [15] IETF RFC 2040 (1996), *The RC5, RC5-CBC, RC5-CBC-Pad, and RC5-CTS Algorithms*.
+- [16] IETF RFC 3217 (2001), *Triple-DES and RC2 Key Wrapping*.
+- [17] IETF RFC 3394 (2002), *Advanced Encryption Standard (AES) Key Wrap Algorithm*.
+- [18] DWORKIN (Morris): Recommendation for Block Cipher Modes of Operation, Methods and Techniques, *NIST Special Publication 800-38A*.
+- [19] GROSBOIS (R.), GERBELOT (P.), EBRAHIMI (T.): Authentication and access control in the JPEG 2000 compressed domain, *In Proc. of the SPIE 46th Annual Meeting, Applications of Digital Image Processing XXIV*, San Diego, 29 July-3 August 2001.
+- [20] RIVEST (R.L.), SHAMIR (A.), ADLEMAN (L.M.): A method for obtaining digital signatures and public-key cryptosystems, *Communications of the ACM* (2) 21, 1978, Page(s): 120-126.
+- [21] WEE (S.), APOSTOLOPOULOS (J.): Secure Scalable Video Streaming for Wireless Networks, *IEEE Inter. Conf. on Acoustics, Speech, and Signal Processing (ICASSP)*, March 2001. Also available at [www.hpl.hp.com/personal/John\\_Apostolopoulos/papers/SecureScalableStreaming\\_ICASSP01.pdf](http://www.hpl.hp.com/personal/John_Apostolopoulos/papers/SecureScalableStreaming_ICASSP01.pdf).
+- [22] WEE (S.), APOSTOLOPOULOS (J.): Secure Scalable Streaming Enabling Transcoding Without Decryption, *IEEE Inter. Conf. on Image Processing (ICIP)*, [http://lib.hpl.hp.com/techpubs/2001/HPL\\_2001\\_320.html](http://lib.hpl.hp.com/techpubs/2001/HPL_2001_320.html) Sept. 2001.
+- [23] WEE (S.), APOSTOLOPOULOS (J.): Secure Scalable Streaming and Secure Transcoding with JPEG 2000, *IEEE Inter. Conf. on Image Processing (ICIP)*, Sept. 2003. <http://lib.hpl.hp.com/techpubs/2003/HPL-2003-117.html>.
+
+
+
+
+
+## SERIES OF ITU-T RECOMMENDATIONS
+
+|                 |                                                                                                                                                           |
+|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Series A        | Organization of the work of ITU-T                                                                                                                         |
+| Series D        | Tariff and accounting principles and international telecommunication/ICT economic and policy issues                                                       |
+| Series E        | Overall network operation, telephone service, service operation and human factors                                                                         |
+| Series F        | Non-telephone telecommunication services                                                                                                                  |
+| Series G        | Transmission systems and media, digital systems and networks                                                                                              |
+| Series H        | Audiovisual and multimedia systems                                                                                                                        |
+| Series I        | Integrated services digital network                                                                                                                       |
+| Series J        | Cable networks and transmission of television, sound programme and other multimedia signals                                                               |
+| Series K        | Protection against interference                                                                                                                           |
+| Series L        | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant |
+| Series M        | Telecommunication management, including TMN and network maintenance                                                                                       |
+| Series N        | Maintenance: international sound programme and television transmission circuits                                                                           |
+| Series O        | Specifications of measuring equipment                                                                                                                     |
+| Series P        | Telephone transmission quality, telephone installations, local line networks                                                                              |
+| Series Q        | Switching and signalling, and associated measurements and tests                                                                                           |
+| Series R        | Telegraph transmission                                                                                                                                    |
+| Series S        | Telegraph services terminal equipment                                                                                                                     |
+| <b>Series T</b> | <b>Terminals for telematic services</b>                                                                                                                   |
+| Series U        | Telegraph switching                                                                                                                                       |
+| Series V        | Data communication over the telephone network                                                                                                             |
+| Series X        | Data networks, open system communications and security                                                                                                    |
+| Series Y        | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities                               |
+| Series Z        | Languages and general software aspects for telecommunication systems                                                                                      |
\ No newline at end of file
diff --git a/marked/T/T-REC-T.808-202212-I_PDF-E/raw.md b/marked/T/T-REC-T.808-202212-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..96bc472d2a52030c6c614ebf2a310c95132d47f1
--- /dev/null
+++ b/marked/T/T-REC-T.808-202212-I_PDF-E/raw.md
@@ -0,0 +1,5721 @@
+
+
+# Recommendation**ITU-T T.808 (V2) (12/2022)**
+
+SERIES T: Terminals for telematic services
+
+Still-image compression – JPEG 2000
+
+---
+
+**Information technology – JPEG 2000 image coding system: Interactivity tools, APIs and protocols**
+
+## ITU-T T-SERIES RECOMMENDATIONS **TERMINALS FOR TELEMATIC SERVICES**
+
+|                                                     |                    |
+|-----------------------------------------------------|--------------------|
+| Facsimile – Framework                               | T.0–T.19           |
+| Still-image compression – Test charts               | T.20–T.29          |
+| Facsimile – Group 3 protocols                       | T.30–T.39          |
+| Colour representation                               | T.40–T.49          |
+| Character coding                                    | T.50–T.59          |
+| Facsimile – Group 4 protocols                       | T.60–T.69          |
+| Telematic services – Framework                      | T.70–T.79          |
+| Still-image compression – JPEG-1, Bi-level and JBIG | T.80–T.89          |
+| Telematic services – ISDN Terminals and protocols   | T.90–T.99          |
+| Videotext – Framework                               | T.100–T.109        |
+| Data protocols for multimedia conferencing          | T.120–T.149        |
+| Telewriting                                         | T.150–T.159        |
+| Multimedia and hypermedia framework                 | T.170–T.189        |
+| Cooperative document handling                       | T.190–T.199        |
+| Telematic services – Interworking                   | T.300–T.399        |
+| Open document architecture                          | T.400–T.429        |
+| Document transfer and manipulation                  | T.430–T.449        |
+| Document application profile                        | T.500–T.509        |
+| Communication application profile                   | T.510–T.559        |
+| Telematic services – Equipment characteristics      | T.560–T.619        |
+| General multimedia application frameworks           | T.620–T.649        |
+| User interfaces – Accessibility and human factors   | T.700–T.799        |
+| <b>Still-image compression – JPEG 2000</b>          | <b>T.800–T.829</b> |
+| Still-image compression   JPEG XR                   | T.830–T.849        |
+| Still-image compression – JPEG-1 extensions         | T.850–T.899        |
+
+*For further details, please refer to the list of ITU-T Recommendations.*
+
+# **Information technology – JPEG 2000 image coding system: Interactivity tools, APIs and protocols**
+
+## Summary
+
+Rec. ITU-T T.808 | ISO/IEC 15444-9 provides a network protocol that allows for the interactive and progressive transmission of JPEG 2000 coded data and files from a server to a client. The first edition of this Recommendation | International Standard dates to 2005. It has since then been supplemented by amendments and corrigenda. Additionally, other members of the JPEG 2000 family of Recommendations | International Standards, that are capable of being used with the network protocol described in this Recommendation | International Standard have since been introduced. This second edition incorporates the changes associated with these developments, without modifying the original scope.
+
+This Recommendation was developed jointly with ISO/IEC JTC 1/SC 29/WG 1 (JPEG), and is common text with ISO/IEC 15444-9.
+
+This second edition cancels and replaces the first edition, which has been technically revised.
+
+The main changes compared to the previous edition are as follows:
+
+1. consolidates all outstanding amendments and corrigenda published since the first edition;
+2. extends support for the file format specified in Rec. ITU-T T.815 | ISO/IEC 15444-16;
+3. clarifies normative server responsibilities in response to certain request fields documented in Annex C;
+4. removes the registration authority (Annex L); and
+5. adds media type registration information (Annex O).
+
+This Recommendation contains an electronic attachment that is available from the ITU website at: <https://handle.itu.int/11.1002/2000/7460>, and from the ISO website at: <https://standards.iso.org/iso-iec/15444/-9/ed-2/en>.
+
+## History
+
+| Edition | Recommendation            | Approval   | Study Group | Unique ID*                                                                 |
+|---------|---------------------------|------------|-------------|----------------------------------------------------------------------------|
+| 1.0     | ITU-T T.808               | 2005-01-08 | 16          | <a href="https://handle.itu.int/11.1002/1000/7460">11.1002/1000/7460</a>   |
+| 1.1     | ITU-T T.808 (2005) Amd. 1 | 2006-05-29 | 16          | <a href="https://handle.itu.int/11.1002/1000/8815">11.1002/1000/8815</a>   |
+| 1.2     | ITU-T T.808 (2005) Cor. 1 | 2007-01-13 | 16          | <a href="https://handle.itu.int/11.1002/1000/9049">11.1002/1000/9049</a>   |
+| 1.3     | ITU-T T.808 (2005) Amd. 2 | 2007-08-29 | 16          | <a href="https://handle.itu.int/11.1002/1000/9232">11.1002/1000/9232</a>   |
+| 1.4     | ITU-T T.808 (2005) Cor. 2 | 2008-06-13 | 16          | <a href="https://handle.itu.int/11.1002/1000/9517">11.1002/1000/9517</a>   |
+| 1.5     | ITU-T T.808 (2005) Amd. 3 | 2008-06-13 | 16          | <a href="https://handle.itu.int/11.1002/1000/9516">11.1002/1000/9516</a>   |
+| 1.6     | ITU-T T.808 (2005) Amd. 4 | 2010-05-22 | 16          | <a href="https://handle.itu.int/11.1002/1000/10646">11.1002/1000/10646</a> |
+| 1.7     | ITU-T T.808 (2005) Cor. 3 | 2011-05-14 | 16          | <a href="https://handle.itu.int/11.1002/1000/11315">11.1002/1000/11315</a> |
+| 1.8     | ITU-T T.808 (2005) Amd. 5 | 2013-03-16 | 16          | <a href="https://handle.itu.int/11.1002/1000/11884">11.1002/1000/11884</a> |
+| 2.0     | ITU-T T.808 (V2)          | 2022-12-14 | 16          | <a href="https://handle.itu.int/11.1002/1000/15209">11.1002/1000/15209</a> |
+
+## Keywords
+
+API, application programme interface, image coding, interactivity, JPEG 2000, protocols.
+
+\* To access the Recommendation, type the URL <http://handle.itu.int/> in the address field of your web browser, followed by the Recommendation's unique ID. For example, <http://handle.itu.int/11.1002/1000/11830-en>.
+
+## FOREWORD
+
+The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis.
+
+The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics.
+
+The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1.
+
+In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC.
+
+## NOTE
+
+In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party.
+
+## INTELLECTUAL PROPERTY RIGHTS
+
+ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process.
+
+As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at <http://www.itu.int/ITU-T/ipr/>.
+
+© ITU 2023
+
+All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU.
+
+## CONTENTS
+
+|                                                                                   | <i>Page</i> |
+|-----------------------------------------------------------------------------------|-------------|
+| 1 Scope .....                                                                     | 1           |
+| 2 Normative references .....                                                      | 1           |
+| 3 Definitions .....                                                               | 2           |
+| 3.1 JPEG 2000 definitions .....                                                   | 2           |
+| 3.2 HTTP definitions .....                                                        | 2           |
+| 3.3 JPIP definitions .....                                                        | 2           |
+| 3.4 Symbols .....                                                                 | 4           |
+| 4 Abbreviations .....                                                             | 6           |
+| 5 Conventions .....                                                               | 6           |
+| 5.1 ABNF rules .....                                                              | 6           |
+| 5.2 File format ABNF rules .....                                                  | 7           |
+| 5.3 Key to graphical descriptions of boxes (informative) .....                    | 7           |
+| 6 General description .....                                                       | 8           |
+| 6.1 JPIP protocol .....                                                           | 8           |
+| 6.2 Purpose .....                                                                 | 9           |
+| 7 Conformance .....                                                               | 10          |
+| Annex A – The JPP-stream and JPT-stream media types .....                         | 11          |
+| A.1 Introduction .....                                                            | 11          |
+| A.2 Message header structure .....                                                | 12          |
+| A.3 Data-bins .....                                                               | 14          |
+| A.4 Conventions for parsing and delivery of JPP-streams and JPT-streams .....     | 22          |
+| A.5 Conventions for JPP-stream or JPT-stream interoperability (informative) ..... | 22          |
+| Annex B – Sessions, channels, cache model and model-sets .....                    | 23          |
+| B.1 Requests within a session vs. stateless requests .....                        | 23          |
+| B.2 Channels and sessions .....                                                   | 23          |
+| B.3 Cache model management .....                                                  | 24          |
+| B.4 Interrogation and manipulation of model-sets .....                            | 24          |
+| Annex C – Client request .....                                                    | 25          |
+| C.1 Request syntax .....                                                          | 25          |
+| C.2 Target identification fields .....                                            | 26          |
+| C.3 Fields for working with sessions and channels .....                           | 28          |
+| C.4 View-window request fields .....                                              | 29          |
+| C.5 Metadata request fields .....                                                 | 42          |
+| C.6 Data limiting request fields .....                                            | 48          |
+| C.7 Server control request fields .....                                           | 48          |
+| C.8 Cache management request fields .....                                         | 52          |
+| C.9 Upload request parameters .....                                               | 57          |
+| C.10 Client capability and preference request fields .....                        | 57          |
+| Annex D – Server response signalling .....                                        | 65          |
+| D.1 Reply syntax .....                                                            | 65          |
+| D.2 JPIP response headers .....                                                   | 67          |
+| D.3 Response data .....                                                           | 72          |
+| Annex E – Uploading images to the server .....                                    | 73          |
+| E.1 Introduction .....                                                            | 73          |
+| E.2 Upload request .....                                                          | 73          |
+| E.3 Server response .....                                                         | 73          |
+| E.4 Merging data on the server .....                                              | 74          |
+| Annex F – Using JPIP over HTTP .....                                              | 76          |
+| F.1 Introduction .....                                                            | 76          |
+| F.2 Requests .....                                                                | 76          |
+| F.3 Session establishment .....                                                   | 77          |
+
+|                                                                        |                                                                                               |     |
+|------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------|-----|
+| F.4                                                                    | Responses.....                                                                                | 77  |
+| F.5                                                                    | Additional HTTP features .....                                                                | 78  |
+| F.6                                                                    | HTTP and length request field (informative) .....                                             | 79  |
+| Annex G – Using JPIP with HTTP requests and TCP returns .....          |                                                                                               | 80  |
+| G.1                                                                    | Introduction .....                                                                            | 80  |
+| G.2                                                                    | Client requests .....                                                                         | 80  |
+| G.3                                                                    | Session establishment.....                                                                    | 80  |
+| G.4                                                                    | Server responses.....                                                                         | 81  |
+| G.5                                                                    | TCP and length request field (informative).....                                               | 81  |
+| Annex H – Using JPIP with alternate transports.....                    |                                                                                               | 82  |
+| H.1                                                                    | Introduction .....                                                                            | 82  |
+| H.2                                                                    | Reliable requests with unreliable data .....                                                  | 82  |
+| H.3                                                                    | Unreliable requests with unreliable data .....                                                | 83  |
+| H.4                                                                    | Request and response syntax .....                                                             | 83  |
+| H.5                                                                    | Session establishment.....                                                                    | 84  |
+| Annex I – Indexing JPEG 2000 files for JPIP .....                      |                                                                                               | 85  |
+| I.1                                                                    | Introduction (informative).....                                                               | 85  |
+| I.2                                                                    | Identifying the use of JPIP index boxes in the JPEG 2000 file format compatibility list ..... | 86  |
+| I.3                                                                    | Defined boxes.....                                                                            | 86  |
+| I.4                                                                    | Association of codestream indexes with codestreams.....                                       | 94  |
+| I.5                                                                    | Placement restrictions (informative) .....                                                    | 94  |
+| Annex J – Profiles and variants for interoperability and testing ..... |                                                                                               | 95  |
+| J.1                                                                    | Introduction .....                                                                            | 95  |
+| J.2                                                                    | Definition of variants .....                                                                  | 95  |
+| J.3                                                                    | Definition of profiles .....                                                                  | 96  |
+| J.4                                                                    | Testing methodology .....                                                                     | 98  |
+| Annex K – Using JPIP with HTTP requests and UDP returns .....          |                                                                                               | 103 |
+| K.1                                                                    | Introduction .....                                                                            | 103 |
+| K.2                                                                    | Client requests .....                                                                         | 103 |
+| K.3                                                                    | Response data delivery and channel establishment .....                                        | 103 |
+| K.4                                                                    | Server responses.....                                                                         | 104 |
+| K.5                                                                    | Framing of response data into chunks .....                                                    | 104 |
+| K.6                                                                    | Client acknowledgement of server responses.....                                               | 105 |
+| K.7                                                                    | UDP and Maximum Response Length Field (informative).....                                      | 106 |
+| K.8                                                                    | Implementation strategies for acknowledged communication (informative) .....                  | 106 |
+| K.9                                                                    | Implementation strategies for unacknowledged communication (informative) .....                | 106 |
+| Annex L – Registration of extensions.....                              |                                                                                               | 108 |
+| Annex M – Application examples .....                                   |                                                                                               | 109 |
+| M.1                                                                    | Introduction .....                                                                            | 109 |
+| M.2                                                                    | Use of JPIP with codestreams in other file formats.....                                       | 109 |
+| M.3                                                                    | Tile-part implementation techniques.....                                                      | 109 |
+| M.4                                                                    | Precinct-based implementation techniques .....                                                | 110 |
+| M.5                                                                    | JPIP protocol transcripts.....                                                                | 111 |
+| M.6                                                                    | Using JPIP with HTML.....                                                                     | 114 |
+| Annex N – JPIP ABNF collection .....                                   |                                                                                               | 115 |
+| N.1                                                                    | JPIP Request ABNF .....                                                                       | 115 |
+| N.2                                                                    | JPIP Response BNF .....                                                                       | 122 |
+| Annex O – Media type specifications and registrations.....             |                                                                                               | 126 |
+| O.1                                                                    | General .....                                                                                 | 126 |
+| O.2                                                                    | JPP-stream.....                                                                               | 126 |
+| O.3                                                                    | JPT-stream .....                                                                              | 127 |
+| Bibliography .....                                                     |                                                                                               | 128 |
+
+# Figures
+
+|                                                                                                                                                                                            | <i>Page</i> |
+|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------|
+| Figure 1 – Example of the box description figures .....                                                                                                                                    | 8           |
+| Figure 2 – Example of the superbox description figures .....                                                                                                                               | 8           |
+| Figure 3 – JPIP protocol overview .....                                                                                                                                                    | 8           |
+| Figure 4 – JPIP protocol stack .....                                                                                                                                                       | 9           |
+| Figure A.1 – Examples of a JPEG 2000 file, JPIP data-bins and JPIP-stream relationships (after G.J. Colyer and R.A. Clark, IEEE Trans. Consumer Electronics, 49 (2003), pp. 850–854) ..... | 11          |
+| Figure A.2 – VBAS structure .....                                                                                                                                                          | 12          |
+| Figure A.3 – Bin-ID VBAS structure .....                                                                                                                                                   | 12          |
+| Figure A.4 – Example precinct data-bin .....                                                                                                                                               | 15          |
+| Figure A.5 – Metadata-bin example colour scheme .....                                                                                                                                      | 16          |
+| Figure A.6 – A sample JP2 file .....                                                                                                                                                       | 17          |
+| Figure A.7 – A sample JP2 file divided into three metadata-bins .....                                                                                                                      | 17          |
+| Figure A.8 – A superbox with a referenced metadata-bin .....                                                                                                                               | 18          |
+| Figure A.9 – An invalid division of the file into metadata-bins .....                                                                                                                      | 18          |
+| Figure A.10 – Example of the use of stream equivalents .....                                                                                                                               | 19          |
+| Figure A.11 – Placeholder box structure .....                                                                                                                                              | 20          |
+| Figure C.1 – Desired region within an image .....                                                                                                                                          | 30          |
+| Figure C.2 – Desired region with respect to the subsampled reference grid .....                                                                                                            | 30          |
+| Figure C.3 – Colourspace specification box selection procedure .....                                                                                                                       | 61          |
+| Figure G.1 – Response data structure on http-tcp connection .....                                                                                                                          | 81          |
+| Figure I.1 – Part of an example JPEG 2000 file containing JPIP index boxes .....                                                                                                           | 86          |
+| Figure I.2 – Organization of the contents of a Codestream Index box .....                                                                                                                  | 87          |
+| Figure I.3 – Organization of the contents of a Codestream Finder box .....                                                                                                                 | 88          |
+| Figure I.4 – Organization of the contents of a Manifest box .....                                                                                                                          | 88          |
+| Figure I.5 – Organization of the contents of a Fragment Array Index box .....                                                                                                              | 89          |
+| Figure I.6 – Organization of the contents of a Header Index Table box .....                                                                                                                | 90          |
+| Figure I.7 – Organization of the contents of a Tile-part Index Table box .....                                                                                                             | 91          |
+| Figure I.8 – Organization of the contents of a Tile Header Index Table box .....                                                                                                           | 91          |
+| Figure I.9 – Organization of the contents of a Precinct Packet Index Table box .....                                                                                                       | 91          |
+| Figure I.10 – Organization of the contents of a Packet Header Index Table box .....                                                                                                        | 92          |
+| Figure I.11 – Organization of the contents of a File Index box .....                                                                                                                       | 92          |
+| Figure I.12 – Organization of the contents of a File Finder box .....                                                                                                                      | 93          |
+| Figure I.13 – Organization of the contents of a Proxy box .....                                                                                                                            | 93          |
+| Figure I.14 – Organization of the contents of an Index Finder box .....                                                                                                                    | 94          |
+| Figure K.1 – Response data structure on http-udp connection .....                                                                                                                          | 104         |
+
+## Tables
+
+|                                                                                                   | <i>Page</i> |
+|---------------------------------------------------------------------------------------------------|-------------|
+| Table A.1 – Bin-ID additional VBAS indication.....                                                | 13          |
+| Table A.2 – Class identifiers for different data-bin message classes.....                         | 13          |
+| Table A.3 – Valid values for the Flags field of a Placeholder box .....                           | 21          |
+| Table C.1 – Round direction options .....                                                         | 33          |
+| Table C.2 – Metadata request qualifier flags .....                                                | 47          |
+| Table C.3 – Alignment boundaries based on bin type .....                                          | 49          |
+| Table C.4 – Valid image return types .....                                                        | 49          |
+| Table C.5 – Cache descriptor option summary.....                                                  | 55          |
+| Table C.6 – Valid capabilities of the <code>processing-capabilities</code> element.....           | 58          |
+| Table C.7 – Valid values of the <code>config-capability</code> parameter.....                     | 58          |
+| Table C.8 – View-window handling preferences.....                                                 | 60          |
+| Table C.9 – Colourspace method client preferences.....                                            | 60          |
+| Table C.10 – Placeholder preferences .....                                                        | 62          |
+| Table C.11 – Codestream sequencing preferences .....                                              | 63          |
+| Table C.12 – Conciseness preferences.....                                                         | 63          |
+| Table D.1 – Valid values of <code>transport-param</code> .....                                    | 67          |
+| Table D.2 – Defined reason codes .....                                                            | 72          |
+| Table D.3 – Additional <code>handled-req-option</code> values for particular request fields ..... | 72          |
+| Table I.1 – Defined boxes (Informative) .....                                                     | 87          |
+| Table I.2 – Container type values .....                                                           | 88          |
+| Table I.3 – Version values .....                                                                  | 90          |
+| Table J.1 – Defining requirements of variants.....                                                | 96          |
+| Table J.2 – Set of fields included in each profile.....                                           | 97          |
+| Table K.1 – Interpretation of the "control" field in each data chunk header.....                  | 105         |
+| Table M.1 – Example of the use of auxiliary fields in a simple case.....                          | 110         |
+| Table M.2 – Example of the use of auxiliary fields in a more complicated case.....                | 110         |
+
+# Introduction
+
+Rec. ITU-T T.800 | ISO/IEC 15444-1 (JPEG 2000) is a specification that describes an image compression system that allows great flexibility, not only for the compression of images but also for access into the codestream. The codestream provides a number of mechanisms for locating and extracting portions of the compressed image data for the purpose of retransmission, storage, display, or editing. This access allows storage and retrieval of compressed image data appropriate for a given application without decoding.
+
+The purpose of this Recommendation | International Standard is to provide a network protocol that allows for the interactive and progressive transmission of JPEG 2000 coded data and files from a server to a client. This protocol allows a client to request only the portions of an image (by region, quality or resolution level) that are applicable to the client's needs. The protocol also allows the client to access metadata or other content from the file.
+
+The substantive updates in this edition, compared to Edition 1, are:
+
+1. consolidates all outstanding amendments and corrigenda published since the first edition;
+2. extends support the file format specified in Rec. ITU-T T.815 | ISO/IEC 15444-16;
+3. clarifies normative server responsibilities in response to certain request fields documented in Annex C;
+4. removes the registration authority (Annex L); and
+5. adds media type registration information (Annex O).
+
+
+
+## **INTERNATIONAL STANDARD ITU-T RECOMMENDATION**
+
+# **Information technology – JPEG 2000 image coding system: Interactivity tools, APIs and protocols**
+
+# 1 Scope
+
+This Recommendation | International Standard<sup>1</sup> defines, in an extensible manner, syntaxes and methods for the remote interrogation and optional modification of JPEG 2000 codestreams and files in accordance with their definition in Rec. ITU-T T.800 | ISO/IEC 15444-1 and other members of the Rec. ITU-T T.8xx | ISO/IEC 15444-x family of Recommendations | Standards.
+
+In this Recommendation | International Standard, the defined syntaxes and methods are referred to as the JPEG 2000 Interactive Protocol, "JPIP", and interactive applications using JPIP are referred to as "JPIP systems."
+
+JPIP specifies a protocol consisting of a structured series of interactions between a client and a server by means of which image file metadata, structure and partial or whole image codestreams can be exchanged in a manner that avoids or minimises the communication of information not required by client. This Recommendation | International Standard includes definitions of the semantics and values to be exchanged, and suggests how these can be passed using a variety of existing network transports.
+
+With JPIP, the following tasks can be accomplished in varying, compatible ways:
+
+- the exchange of capabilities;
+- the negotiation of capabilities to use in a session;
+- the request and transfer of the following elements from a variety of containers, such as JPEG 2000 files, JPEG 2000 codestreams and other container files:
+  - selective data segments;
+  - selective and defined structures;
+  - parts of an image or its related metadata.
+
+# 2 Normative references
+
+The following Recommendations and International Standards contain provisions which, through reference in this text, constitute provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
+
+- Recommendation ITU-T T.800 | ISO/IEC 15444-1, *Information technology – JPEG 2000 image coding system: Core coding system*.
+- Recommendation ITU-T T.801 | ISO/IEC 15444-2, *Information technology – JPEG 2000 image coding system: Extensions*.
+- Recommendation ITU-T T.802 | ISO/IEC 15444-3, *Information technology – JPEG 2000 image coding system: Motion JPEG 2000*.
+- Recommendation ITU-T T.805 | ISO/IEC 15444-6, *Information technology – JPEG 2000 image coding system: Compound image file format*.
+- Recommendation ITU-T T.809 | ISO/IEC 15444-10, *Information technology – JPEG 2000 image coding system: Extensions for three-dimensional data*.
+- Recommendation ITU-T T.814 | ISO/IEC 15444-15, *Information technology – High-Throughput JPEG 2000*.
+- Recommendation ITU-T T.815 | ISO/IEC 15444-16, *Information technology – Encapsulation of JPEG 2000 images into ISO/IEC 23008-12*.
+
+<sup>1</sup> This Recommendation | International Standard contains an electronic attachment that is available from the ITU website at: <https://handle.itu.int/11.1002/2000/7460>, and from the ISO website at: <https://standards.iso.org/iso-iec/15444/-9/ed-2/en>.
+
+- IETF RFC 768 (1980), *User Datagram Protocol*. Available from World Wide Web: <http://www.ietf.org/rfc/rfc0768.txt>.
+- IETF RFC 2046 (1996), *Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types*. Available from World Wide Web: <http://www.ietf.org/rfc/rfc2046.txt>.
+- IETF RFC 2616 (1999), *Hypertext Transfer Protocol – HTTP/1.1*. Available from World Wide Web: <http://www.ietf.org/rfc/rfc2616.txt>.
+- IETF RFC 3986 (2005), *Uniform Resource Identifiers (URI): Generic Syntax*. Available from World Wide Web: <https://datatracker.ietf.org/doc/html/rfc3986>.
+- IETF RFC 5234 (2008), *Augmented BNF for Syntax Specifications: ABNF*. Available from World Wide Web: <https://datatracker.ietf.org/doc/html/rfc5234>.
+- IETF RFC 9293 (2022), *Transmission Control Protocol*. Available from World Wide Web: <https://datatracker.ietf.org/doc/html/rfc9293>.
+
+# 3 Definitions
+
+For the purposes of this Recommendation | International Standard, the terms and definitions given in Rec. ITU-T T.800 | ISO/IEC 15444-1 and Rec. ITU-T T.801 | ISO/IEC 15444-2 apply.
+
+ISO and IEC maintain terminology databases for use in standardization at the following addresses:
+
+- ISO Online browsing platform: available at <https://www.iso.org/obp>
+- IEC Electropedia: available at <https://www.electropedia.org>
+
+## 3.1 JPEG 2000 definitions
+
+The following definitions are used within this Recommendation | International Standard. In some cases, these definitions differ from those used in other standards and/or Recommendations.
+
+- 3.1.1 J2KI:** A file that conforms to the 'j2ki' brand specified in Rec. ITU-T T.815 | ISO/IEC 15444-16.
+- 3.1.2 J2KS:** A file that conforms to the 'j2ks' brand specified in Rec. ITU-T T.815 | ISO/IEC 15444-16.
+- 3.1.3 JPH:** The file format specified in Rec. ITU-T T.814 | ISO/IEC 15444-15: High Throughput JPEG 2000.
+- 3.1.4 JPEG 2000 codestream:** Codestream conforming to the specification in Rec. ITU-T T.800 | ISO/IEC 15444-1, possibly including capabilities specified elsewhere.
+- 3.1.5 JPEG 2000 family file:** File conforming to one of the file formats defined in the Rec. ITU-T T.8xx | ISO/IEC 15444-x family of Recommendations | Standards.
+- 3.1.6 JPM:** The file format specified in Rec. ITU-T T.805 | ISO/IEC 15444-6.
+- 3.1.7 metadata:** Any collection of "boxes" from a JPEG 2000 family file.
+- 3.1.8 MJ2:** The file format specified in Rec. ITU-T T.802 | ISO/IEC 15444-3.
+
+## 3.2 HTTP definitions
+
+The following definitions are intended to match HTTP/1.1. In the case of any difference, these definitions shall be used.
+
+- 3.2.1 connection:** Transport layer virtual circuit established between two programs for the purpose of communication.
+- 3.2.2 entity:** The information transferred as the payload of a request or response.  
+Note on entry: An entity consists of metainformation in the form of entity-header fields and content in the form of an entity-body.
+- 3.2.3 proxy:** An intermediary program which acts as both a server and a client for the purpose of making requests on behalf of other clients.  
+Note on entry: Requests are serviced internally or by passing them on, with possible translation, to other servers.
+
+## 3.3 JPIP definitions
+
+The following definitions are used within this Recommendation | International Standard. In some cases, these definitions differ from those used in other standards and/or Recommendations.
+
+**3.3.1 cache (client-side):** Cache managed by the Client for storing JPIP data-bins.
+
+Note on entry: The Client might have a limited cache and might have to purge cached JPIP data-bins from time to time.
+
+**3.3.2 cacheable response:** Response that may be stored within a cache for use in answering subsequent requests.
+
+Note on entry: Even if a resource is cacheable, there might be additional constraints on whether a cache can use the cached copy for a particular request.
+
+**3.3.3 cache-model (server-side):** Server-side estimation of the data-bins or portions of data-bins that are available in the client's cache.
+
+Note on entry: The server can add items to its estimation of the client's cache because it assumes successfully delivery, or because it has received acknowledgements of transmitted data, or because of cache-model update statements.
+
+**3.3.4 channel:** Mechanism for grouping requests and responses such that only one request/response is active at a time within the group.
+
+Note on entry: Multiple channels can be used to issue multiple requests and receive multiple responses concurrently.
+
+**3.3.5 client:** Program that establishes connections for the purpose of sending requests.
+
+**3.3.6 codestream image region:** Intersection between the image and the region defined by the Offset and Region Size.
+
+Note on entry: The codestream image region can be empty (no area).
+
+**3.3.7 data-bin:** Set of bytes of the same type of data which can be partially delivered.
+
+**3.3.8 incremental-codestream:** Representation of the codestream as a collection of data-bins (main header, tile header, precinct or tile data-bins) having the same codestream identifier.
+
+**3.3.9 JPIP index table:** File format box which provides information about the location of portions of a file or codestream.
+
+**3.3.10 JPEG 2000 family target:** Target that corresponds to a JPEG 2000 family file.
+
+**3.3.11 logical target:** Specific representation of specific original named resource, or a byte range from that specific original named resource, to which the JPIP request is directed.
+
+Note on entry: The specific representation might be transcoded from the original named resource.
+
+**3.3.12 message:** Set of bytes from a single data-bin and the header identifying those bytes and the data-bin.
+
+**3.3.13 raw codestream:** Representation of the codestream as a single metadata-bin.
+
+**3.3.14 request:** Group of fields and values sent from the client to the server to obtain portions of an image or metadata.
+
+**3.3.15 resource:** Network data object or service that can be identified by a URI.
+
+**3.3.16 response:** Bytes sent from the server to the client after receiving a request.
+
+**3.3.17 server:** Application program that accepts connections in order to service requests by sending back responses.
+
+Note on entry: Any given program might be capable of being both a client and a server; use of these terms refers only to the role being performed by the program for a particular connection, rather than to the program's capabilities in general.
+
+**3.3.18 session:** Collection of requests and responses applying to the same resource for which the server maintains a cache model.
+
+**3.3.19 session-based:** Where the server maintains a cache model.
+
+**3.3.20 stateless:** Single request where the server does not make use of a cache-model in determining the response.
+
+**3.3.21 target:** Logical identification of JPIP data.
+
+Note 1 on entry: This is the name of the main target and is often the name of a file on the server.
+
+Note 2 on entry: JPEG 2000 files or codestreams might be available in multiple representations (e.g., return type, precinct size) or vary in other ways, each identified by a unique logical target.
+
+**3.3.22 tile header:** All tile-part headers for a specific tile.
+
+**3.3.23 view-window:** The portion of the image data that the client desires, as expressed by the combination of the following fields that appear in the request: Region Size, Offset, Frame Size, Codestream, Codestream Context, Sampling Rate, ROI and Layers.
+
+Note on entry: The view-window is often smaller than the whole image data.
+
+**3.3.24 slice:** Subset of voxels in a volumetric image with the same Z coordinate.
+
+**3.3.25 profile:** Set of request fields that a server is expected to support and implement and a client communicating with a server in this profile may issue, with the expectation that the server supports them.
+
+Note 1 on entry: Conformance is structured according to profiles.
+
+Note 2 on entry: See Annex J.
+
+**3.3.26 variant:** Collection of operating modes and features of the JPIP standard that a client and a server use to exchange requests and data.
+
+Note on entry: Clients and servers interoperate by employing a common subset of all variants.
+
+## 3.4 Symbols
+
+For the purposes of this Recommendation | International Standard, the following symbols apply. The symbols defined in Rec. ITU-T T.800 | ISO/IEC 15444-1 and Rec. ITU-T T.801 | ISO/IEC 15444-2 also apply to this Recommendation | International Standard.
+
+|                          |                                                                                                                                              |
+|--------------------------|----------------------------------------------------------------------------------------------------------------------------------------------|
+| <b>c</b>                 | An index (starting from 0) of the image component to which the precinct belongs                                                              |
+| <b>fx</b>                | x-axis frame size for client request view-window                                                                                             |
+| <b>fy</b>                | y-axis frame size for client request view-window                                                                                             |
+| <b>fz</b>                | z-axis frame size for client request view-window                                                                                             |
+| <b>fx'</b>               | x-axis frame size for codestream resolution selected by the server based on the client request                                               |
+| <b>fy'</b>               | y-axis frame size for codestream resolution selected by the server based on the client request                                               |
+| <b>fz'</b>               | z-axis frame size for codestream resolution selected by the server based on the client request                                               |
+| <b>fx''</b>              | Modified jpx x-axis frame size for suitable resolution                                                                                       |
+| <b>fy''</b>              | Modified jpx y-axis frame size for suitable resolution                                                                                       |
+| <b>fz''</b>              | Modified jpx z-axis frame size for suitable resolution                                                                                       |
+| <b>H<sub>cod</sub></b>   | The codestream height as recorded in the Image Header (ihdr) box (see Annex I.5.3.1 of Rec. ITU-T T.800   ISO/IEC 15444-1)                   |
+| <b>H<sub>comp</sub></b>  | The height of the composited result, supplied in the JPX composition options box (see Annex M.11.10.1 of Rec. ITU-T T.801   ISO/IEC 15444-2) |
+| <b>H<sub>reg</sub></b>   | The height of the compositing layer, as it appears on the compositing layer registration grid                                                |
+| <b>HS<sub>inst</sub></b> | The cropped height                                                                                                                           |
+| <b>Ht<sub>inst</sub></b> | The composited height                                                                                                                        |
+| <b>I</b>                 | The unique identifier of a precinct within its codestream                                                                                    |
+| <b>N<sub>L</sub></b>     | Is the number of decomposition levels                                                                                                        |
+| <b>num_components</b>    | The number of components encoded                                                                                                             |
+| <b>num_tiles</b>         | The number of tiles in the codestream                                                                                                        |
+| <b>ox</b>                | x-axis offset for client request view-window                                                                                                 |
+| <b>oy</b>                | y-axis offset for client request view-window                                                                                                 |
+| <b>oz</b>                | z-axis offset for client request view-window                                                                                                 |
+| <b>ox'</b>               | x-axis offset for suitable codestream region                                                                                                 |
+| <b>oy'</b>               | y-axis offset for suitable codestream region                                                                                                 |
+| <b>oz'</b>               | z-axis offset for suitable codestream region                                                                                                 |
+| <b>ox''</b>              | Modified jpx x-axis offset for suitable region                                                                                               |
+| <b>oy''</b>              | Modified jpx y-axis offset for suitable region                                                                                               |
+| <b>oz''</b>              | Modified jpx z-axis offset for suitable region                                                                                               |
+
+|                                            |                                                                                                                                                                              |
+|--------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| <b><i>r</i></b>                            | Resolution level                                                                                                                                                             |
+| <b><i>s</i></b>                            | A sequence number which identifies the precinct within its tile-component                                                                                                    |
+| <b><i>sx</i></b>                           | x-axis size of client request view-window                                                                                                                                    |
+| <b><i>sy</i></b>                           | y-axis size of client request view-window                                                                                                                                    |
+| <b><i>sz</i></b>                           | z-axis size of client request view-window                                                                                                                                    |
+| <b><i>sx'</i></b>                          | x-axis size for suitable codestream region                                                                                                                                   |
+| <b><i>sy'</i></b>                          | y-axis size for suitable codestream region                                                                                                                                   |
+| <b><i>sz'</i></b>                          | z-axis size for suitable codestream region                                                                                                                                   |
+| <b><i>sx''</i></b>                         | Modified jpx x-axis size for suitable region                                                                                                                                 |
+| <b><i>sy''</i></b>                         | Modified jpx y-axis size for suitable region                                                                                                                                 |
+| <b><i>sz''</i></b>                         | Modified jpx z-axis size for suitable region                                                                                                                                 |
+| <b><i>t</i></b>                            | An index (starting from 0) of the tile to which the precinct belongs                                                                                                         |
+| <b><i>W<sub>cod</sub></i></b>              | The codestream width as recorded in the Image Header (ihdr) box (see Annex I.5.3.1 of Rec. ITU-T T.800   ISO/IEC 15444-1)                                                    |
+| <b><i>W<sub>comp</sub></i></b>             | The width of the composited result, supplied in the JPX composition options box (see Annex M.11.10.1 of Rec. ITU-T T.801   ISO/IEC 15444-2)                                  |
+| <b><i>W<sub>reg</sub></i></b>              | The width of the compositing layer, as it appears on the compositing layer registration grid                                                                                 |
+| <b><i>W<sub>s<sub>inst</sub></sub></i></b> | The cropped width                                                                                                                                                            |
+| <b><i>W<sub>t<sub>inst</sub></sub></i></b> | The composited width                                                                                                                                                         |
+| <b><i>XC<sub>inst</sub></i></b>            | The x-axis cropping offset supplied via the relevant instruction (see Annex M.11.10.2.1 of Rec. ITU-T T.801   ISO/IEC 15444-2)                                               |
+| <b><i>XO<sub>inst</sub></i></b>            | The x-axis compositing offset, described via the relevant compositing instruction (see Annex M.11.10.2.1 of Rec. ITU-T T.801   ISO/IEC 15444-2)                              |
+| <b><i>XO<sub>reg</sub></i></b>             | The x-axis codestream registration offset                                                                                                                                    |
+| <b><i>XO<sub>siz</sub></i></b>             | The horizontal offset from the origin of the reference grid of the relevant codestream's SIZ marker segment                                                                  |
+| <b><i>XR<sub>reg</sub></i></b>             | The x-axis codestream registration sampling factor, described at the beginning of any codestream registration box (see Annex M.11.7.7 of Rec. ITU-T T.801   ISO/IEC 15444-2) |
+| <b><i>Xs<sub>siz</sub></i></b>             | The width of the reference grid of the relevant codestream's SIZ marker segment                                                                                              |
+| <b><i>XS<sub>reg</sub></i></b>             | The x-axis registration precision described at the beginning of any codestream registration box (see Annex M.11.7.7 of Rec. ITU-T T.801   ISO/IEC 15444-2)                   |
+| <b><i>YC<sub>inst</sub></i></b>            | The y-axis cropping offset supplied via the relevant instruction (see Annex M.11.10.2.1 of Rec. ITU-T T.801   ISO/IEC 15444-2)                                               |
+| <b><i>YO<sub>inst</sub></i></b>            | The y-axis compositing offset, described via the relevant compositing instruction (see Annex M.11.10.2.1 of Rec. ITU-T T.801   ISO/IEC 15444-2)                              |
+| <b><i>YO<sub>reg</sub></i></b>             | The y-axis codestream registration offset                                                                                                                                    |
+| <b><i>YO<sub>siz</sub></i></b>             | The vertical offset from the origin of the reference grid of the relevant codestream's SIZ marker segment                                                                    |
+| <b><i>YR<sub>reg</sub></i></b>             | The y-axis codestream registration sampling factor, described at the beginning of any codestream registration box (see Annex M.11.7.7 of Rec. ITU-T T.801   ISO/IEC 15444-2) |
+| <b><i>Ys<sub>siz</sub></i></b>             | The height of the reference grid of the relevant codestream's SIZ marker segment                                                                                             |
+
+**YS<sub>reg</sub>** The y-axis registration precision described at the beginning of any codestream registration box (see Annex M.11.7.7 of Rec. ITU-T T.801 | ISO/IEC 15444-2)
+
+# 4 Abbreviations
+
+For the purposes of this Recommendation | International Standard, the following abbreviations apply.
+
+|       |                                                |
+|-------|------------------------------------------------|
+| ABNF  | Augmented Backus-Naur Form                     |
+| DICOM | Digital Imaging and Communications in Medicine |
+| DWT   | Discrete Wavelet Transformation                |
+| EOR   | End of Response                                |
+| HTML  | Hypertext Markup Language                      |
+| IP    | Internet Protocol                              |
+| JPIP  | JPEG 2000 Interactive Protocol                 |
+| JPP   | JPIP Precinct                                  |
+| JPT   | JPIP Tile-part                                 |
+| MTF   | Modulation Transfer Function                   |
+| PDF   | Portable Document Format                       |
+| SVG   | Scalable Vector Graphics                       |
+| TCP   | Transmission Control Protocol                  |
+| UDP   | User Datagram Protocol                         |
+| UUID  | Universal Unique Identifier                    |
+| VBAS  | Variable-length Byte Aligned Segment           |
+| XHTML | Extensible Hypertext Markup Language           |
+| XML   | Extensible Markup Language                     |
+
+# 5 Conventions
+
+## 5.1 ABNF rules
+
+This Recommendation | International Standard uses the ABNF notation defined in RFC 5234, including the core ABNF syntax rules: ALPHA (letters), CR (carriage return), CRLF (Internet standard newline), CTL (control characters), DIGIT (decimal digits), HEXDIG (hexadecimal digits), LF (line feed), LWSP (linear white space) and SP (space). For the purposes of this Recommendation | International Standard, the following ABNF rules also apply.
+
+```
+
+NZDIGIT = %x31-39           ; 1-9
+UPPER = %x41-5A             ; A-Z
+LOWER = %x61-7A             ; a-z
+UINT = 1*DIGIT
+NONZERO = "*"0" NZDIGIT *DIGIT
+UINT-RANGE = UINT ["-" [UINT]]
+UFLOAT = 1*DIGIT ["." 1*DIGIT]
+OCTAL-ENCODED-CHAR = "\" QUADDIG OCTDIG OCTDIG
+QUADDIG = "0" / "1" / "2" / "3"
+OCTDIG = "0" / "1" / "2" / "3" / "4" / "5" / "6" / "7"
+UUID = 16(HEXDIG)
+TOKEN = 1*(ALPHA / DIGIT / "." / "_" / "-")
+TEXT-LABEL = DQUOTE TOKEN DQUOTE
+IDTOKEN = 1*(TOKEN / ";")
+
+```
+
+This Recommendation | International Standard also defines `PATH`, representing a file or pathname. In the general case, `PATH` values may contain any character, although for a given server architecture, the server shall reject any characters that are not valid on that particular server. In addition, `PATH` shall be properly encoded as specified by the transport technology.
+
+`UINT-RANGE` specifies a range of integer values. The first integer in the range specifies the beginning of the range. If two values are specified, the first and second values specify the inclusive beginning and ending limits to the range. If only the first value and the "-" character are specified, the range includes all values greater than or equal to the first value.
+
+A numerical value immediately preceding an ABNF element refers to a repetition of the parameter that follows the number, for the number of times given by the numerical value, with no intervening spaces between each occurrence.
+
+The construct "`1#`" refers to one or more repetitions of the parameter that follows, each occurrence of which is separated by a comma.
+
+The construct "`1$`" refers to one or more repetitions of the parameter that follows, each occurrence of which is separated by a semicolon.
+
+## 5.2 File format ABNF rules
+
+```
+
+compatibility-code = 4(ALPHA / DIGIT / "_" / OCTAL-ENCODED-CHAR)
+box-type = 4(ALPHA / DIGIT / "_" / OCTAL-ENCODED-CHAR)
+box-type-list = "*" / 1#(box-type)
+
+```
+
+`box-type` specifies the four characters of the box type. For each character in the box type, if the character is alpha-numeric (A..Z, a..z or 0..9).
+
+`box-type` specifies the four characters of the box type. For each character in the box type, if the character is alpha-numeric (A..Z, a..z or 0..9), the character is written directly into the string. If the character is a space (\040), then that character shall be encoded as the underscore character ("\_") or by octal encoding. For any other character, a 4-character string is written in its place, consisting of a backslash character ("\") followed by three octal digits representing the value of the character from the box type in octal. The `compatibility-code` is encoded the same way that a `box-type` is encoded.
+
+## 5.3 Key to graphical descriptions of boxes (informative)
+
+The description of each box is followed by a figure that shows the order and relationship of the parameters in the box. Figure 1 shows an example of this type of figure. A rectangle is used to indicate the parameters in the box. The width of the rectangle is proportional to the number of bytes in the parameter. A shaded rectangle (diagonal stripes) indicates that the parameter is of varying size. Two parameters with superscripts and a grey area between indicate a run of several of these parameters. A sequence of two groups of multiple parameters with superscripts separated by a grey area indicates a run of that group of parameters (one set of each parameter in the group, followed by the next set of each parameter in the group). Optional parameters or boxes will be shown with a dashed rectangle.
+
+The figure is followed by a list that describes the meaning of each parameter in the box. If parameters are repeated, the length and nature of the run of parameters is defined. As an example, in Figure 1, parameters A, B, C and D are 8, 16, 32 bit and variable length respectively. The notation  $E^0$  and  $E^{N-1}$  implies that there are N different parameters,  $E^i$ , in a row. The group of parameters  $F^0$  and  $F^{M-1}$ , and  $G^0$  and  $G^{M-1}$  specify that the box will contain  $F^0$ , followed by  $G^0$ , followed by  $F^1$  and  $G^1$ , continuing to  $F^{M-1}$  and  $G^{M-1}$  (M instances of each parameter in total). Also, the field D is optional and might not be found in this box.
+
+In addition, in a figure describing the contents of a superbox, an ellipsis (...) will be used to indicate that the contents of the file between two boxes is not specifically defined. Any box (or sequence of boxes), unless otherwise specified by the definition of that box, can be found in place of the ellipsis.
+
+![Figure 1: Example of the box description figures. This diagram shows a sequence of boxes in a bitstream. Box A is 8-bit, B is 32-bit, and C is 16-bit. Box D is 64-bit. Box E is of variable size and is shaded with diagonal lines. Following box E is a 'Run of N parameters' consisting of boxes F^0 through F^{N-1}. This is followed by a 'Run of M sets of parameters' consisting of boxes G^0, H^0, G^{M-1}, and H^{M-1}. The entire sequence is labeled T.808_F01 at the bottom right.](ff7ce44f3fdd51bae7b231f34df07c6a_img.jpg)
+
+Figure 1: Example of the box description figures. This diagram shows a sequence of boxes in a bitstream. Box A is 8-bit, B is 32-bit, and C is 16-bit. Box D is 64-bit. Box E is of variable size and is shaded with diagonal lines. Following box E is a 'Run of N parameters' consisting of boxes F^0 through F^{N-1}. This is followed by a 'Run of M sets of parameters' consisting of boxes G^0, H^0, G^{M-1}, and H^{M-1}. The entire sequence is labeled T.808\_F01 at the bottom right.
+
+Figure 1 – Example of the box description figures
+
+For example, the superbox shown in Figure 2 contain an AA box and a BB box, and the BB box follows the AA box. However, there can be other boxes found between boxes AA and BB. Dealing with unknown boxes is discussed in Rec. ITU-T T.800 | ISO/IEC 15444-1.
+
+![Figure 2: Example of the superbox description figures. This diagram shows two boxes, AA and BB, both shaded with diagonal lines. They are separated by three dots, indicating that other boxes can exist between them. The entire sequence is labeled T.808_F02 at the bottom right.](9b9d2abd741ed4bafe7f78f89961c663_img.jpg)
+
+Figure 2: Example of the superbox description figures. This diagram shows two boxes, AA and BB, both shaded with diagonal lines. They are separated by three dots, indicating that other boxes can exist between them. The entire sequence is labeled T.808\_F02 at the bottom right.
+
+Figure 2 – Example of the superbox description figures
+
+# 6 General description
+
+## 6.1 JPIP protocol
+
+This Recommendation | International Standard describes the syntaxes and methods that are used when a client is accessing JPEG 2000 compressed imagery and imagery related data residing on a JPIP-enabled server. This Recommendation | International Standard enables the flexibility and functionality intended in Rec. ITU-T T.800 | ISO/IEC 15444-1 to be realized across multiple client/server transports.
+
+JPIP defines the interactive protocol to achieve the efficient exchange of JPEG 2000 imagery and imagery-related data. The protocol defines the Client-Server interactions based on a client request and server response as shown in Figure 3. This Recommendation | International Standard defines the JPIP client requests and the JPIP server responses. HTTP/1.1 (RFC 2616), TCP (RFC 9293) and UDP (RFC 768) are shown as examples of possible transports for JPIP. The client uses a View-Window request to define the resolution, size, location, components, layers, and other parameters for the image and imagery related data that is requested by the client. The server responds by delivering imagery and imagery-related data with precinct-based streams, tile-based streams, or whole images. The protocol also allows for the negotiation of client and server capabilities and limitations. The client can request information about an image as defined in JPIP index tables from the server, which enables the client to refine its View-Window request to image specific parameters (e.g., byte range requests). The server's cache model is based on the capabilities defined by the client and the statefulness of the session.
+
+![Figure 3: JPIP protocol overview. This diagram illustrates the interaction between a Server and a Client. On the Server side, there is a box containing 'Image Metadata', 'Server Capabilities', 'JPP-or JPT-streams', and a 'Cache Model*' (with a note '*Only if State is present'). On the Client side, there is a box containing 'Display Metadata', 'Client Capabilities', 'Data Limits', and a 'Cache'. Between them, a large grey arrow labeled 'Multiple Client Requests' points from the Client to the Server, and a large green arrow labeled 'Multiple Server Responses' points from the Server to the Client. At the bottom, the transports 'HTTP, TCP, UDP' are listed. The diagram is labeled T.808(22)_F03 at the bottom right.](124c6108c63173818afb8ed49521e22d_img.jpg)
+
+Figure 3: JPIP protocol overview. This diagram illustrates the interaction between a Server and a Client. On the Server side, there is a box containing 'Image Metadata', 'Server Capabilities', 'JPP-or JPT-streams', and a 'Cache Model\*' (with a note '\*Only if State is present'). On the Client side, there is a box containing 'Display Metadata', 'Client Capabilities', 'Data Limits', and a 'Cache'. Between them, a large grey arrow labeled 'Multiple Client Requests' points from the Client to the Server, and a large green arrow labeled 'Multiple Server Responses' points from the Server to the Client. At the bottom, the transports 'HTTP, TCP, UDP' are listed. The diagram is labeled T.808(22)\_F03 at the bottom right.
+
+Figure 3 – JPIP protocol overview
+
+This protocol can be used over several different transports as shown in Figure 4. This Recommendation | International Standard includes informative annexes on the use of the JPIP protocol over HTTP, TCP and UDP, and provides suggestions for other example implementations. The JPIP protocol itself is neutral with respect to underlying transport
+
+mechanisms for the client requests and server responses, except in regard to channel requests represented by the New Channel ("cnew") request field (see C.3.3) and the New Channel ("JPIP-cnew") response header (see D.2.3), where transport-specific details shall be communicated. This Recommendation | International Standard defines four specific transports, which are identified by the strings "http", "https", "http-tcp" and "http-udp" in the value string associated with New Channel requests.
+
+![Figure 4 – JPIP protocol stack diagram showing a layered architecture. The stack consists of four layers: JPIP (top, yellow), HTTP (second, white), TCP (third, white), and UDP (third, white). The TCP and UDP layers are side-by-side. The IP layer (bottom, white) spans the width of the TCP and UDP layers. The label 'T.808_F04' is at the bottom right.](2b3a967f6ce4f23649be995a353e39f8_img.jpg)
+
+|      |     |
+|------|-----|
+| JPIP |     |
+| HTTP |     |
+| TCP  | UDP |
+| IP   |     |
+
+T.808\_F04
+
+Figure 4 – JPIP protocol stack diagram showing a layered architecture. The stack consists of four layers: JPIP (top, yellow), HTTP (second, white), TCP (third, white), and UDP (third, white). The TCP and UDP layers are side-by-side. The IP layer (bottom, white) spans the width of the TCP and UDP layers. The label 'T.808\_F04' is at the bottom right.
+
+**Figure 4 – JPIP protocol stack**
+
+The JPIP protocol described in this Recommendation | International Standard provides support for still images, volumetric imagery, motion imagery and animated content, along with a multitude of file formats, as specified by other members of the Rec. ITU-T T.8xx | ISO/IEC 15444-x family of Recommendations | International Standards.
+
+## 6.2 Purpose
+
+This Recommendation | International Standard defines the syntax and methods required for both the client and server. Annexes define components that are required to achieve interoperability and functionality between the client and server over several transports. These annexes are described below.
+
+- Annex A describes the tile-based and precinct-based streams that are required for both the client and the server. The server is required to produce compliant JPP- and JPT-streams and understand uploaded JPP- and JPT-streams. The client is required to understand and properly decode these streams and is responsible for producing compliant streams when uploading partial imagery to the server.
+- Annex B describes the session and cache modelling of a client/server session and is required for both the client and server.
+- Annex C defines the client request syntax. The client shall produce compliant requests and the server shall be able to parse, interpret and respond to all compliant requests.
+- Annex D defines the server response syntax. The server shall produce compliant responses and the client shall be able to understand compliant responses.
+- Annex E defines syntax and methods to upload a partial image for systems which use JPIP for upload.
+- Annexes F, G and H define the methods and procedures for JPIP client/server interactions over several different transport protocols.
+- Annex I defines the indexing information syntax contained in a JPEG 2000 box that can be used by a client and server to more efficiently access imagery and imagery related data.
+- Server and client conformance is further structured into profiles and variants. Profiles define which fields servers are required to support and implement beyond simply parsing and interpreting the fields. Variants define the operating modes and features of the JPIP standard a client and server use to transmit data. Clients and servers need to provide a common subset of variants in order to interoperate. See Annex J for details about conformance and testing for conformance.
+- Annex K describes several examples of using this Recommendation | International Standard for several different applications.
+
+Additional annexes found in this Recommendation | International Standard are as follows.
+
+- Annex L is provided to support extensions to this Recommendation | International Standard.
+- Annex M provides example JPIP applications and protocol transcripts.
+- Annex N collects the ABNF specifications for client requests and server responses, as found in Annex C and Annex D, respectively.
+- Annex O provides media type specifications and registration information.
+
+# 7 Conformance
+
+Conformance with this Recommendation | International Standard by a client means that the client's JPIP requests are well structured, valid and conformant to the JPIP client requests as defined by this Recommendation | International Standard, and that it is able to parse the JPIP responses defined by this Recommendation | International Standard.
+
+Conformance with this Recommendation | International Standard by a server means that the server's JPIP responses are well structured, valid and conformant to the JPIP server response signalling as defined by this Recommendation | International Standard, and is able to parse the JPIP requests defined by this Recommendation | International Standard. Servers shall parse and interpret all normative request types and shall respond to all compliant requests. Compliance to a profile requires servers furthermore to support and implement all mandatory fields within that profile to the extent defined in Annex J.
+
+Conformance, profiles and conformance testing methodologies of this Recommendation | International Standard are defined in Annex J.
+
+It is expected that server applications might send additional data not explicitly requested by a client, or redundant data that has previously been sent to a client, depending on the network quality-of-service. Such implementation decisions are application specific and provide the JPIP system with high utility.
+
+# Annex A
+
+## The JPP-stream and JPT-stream media types
+
+(This annex forms an integral part of this Recommendation | International Standard.)
+
+## A.1 Introduction
+
+JPP-stream and JPT-stream are media types useful for presenting JPEG 2000 codestreams and file format data in an arbitrary order. Each media type consists of a concatenated sequence of messages, where each message contains a portion of a single data-bin preceded by a message header. Data-bins contain portions of a JPEG 2000 compressed image representation, such that it is possible to construct a stream that completely represents the information present in a JPEG 2000 file or codestream. Each message is completely self-describing, so that the sequence of messages can be terminated at any point and messages can be re-ordered subject to minimal constraints without losing their meaning. For these reasons, JPP-stream and JPT-stream media types are useful for JPIP servers and the JPIP protocol is designed with these media types particularly in mind. This annex defines the JPP-stream and JPT-stream media types without reference to the JPIP protocol.
+
+![Diagram illustrating the relationship between a JPEG 2000 file, JPIP data-bins, and JPIP-stream. The top row shows a 'Contiguous codestream box' (containing a red 'main header', orange and yellow 'precincts or tiles', and a blue 'metadata' box) and 'another box' (blue). The middle row shows 'examples of data-bins' (red, orange, yellow, green, blue) and 'examples of messages' (red, orange, yellow, green, blue). The bottom row shows 'examples of stream' (concatenated sequence of data-bins). Arrows indicate the flow from the codestream box to the data-bins and messages, and from the messages to the stream.](4cc7cdce3d498d8b0ba033a9be24ade5_img.jpg)
+
+The diagram illustrates the relationship between a JPEG 2000 file, JPIP data-bins, and JPIP-stream. It is organized into three horizontal levels:
+
+- Top Level:** A 'Contiguous codestream box' containing a red 'main header', orange and yellow 'precincts or tiles', and a blue 'metadata' box. To its right is 'another box' (blue).
+- Middle Level:** 'examples of data-bins' (red, orange, yellow, green, blue) and 'examples of messages' (red, orange, yellow, green, blue). Arrows show that the red data-bin is the main header, the orange and yellow data-bins are precincts or tiles, and the green and blue data-bins are metadata. The messages are formed by concatenating the header and body (data-bin) of each data-bin.
+- Bottom Level:** 'examples of stream' (concatenated sequence of data-bins). Arrows show that the stream is formed by concatenating the messages.
+
+T.808(22)\_FA.1
+
+Diagram illustrating the relationship between a JPEG 2000 file, JPIP data-bins, and JPIP-stream. The top row shows a 'Contiguous codestream box' (containing a red 'main header', orange and yellow 'precincts or tiles', and a blue 'metadata' box) and 'another box' (blue). The middle row shows 'examples of data-bins' (red, orange, yellow, green, blue) and 'examples of messages' (red, orange, yellow, green, blue). The bottom row shows 'examples of stream' (concatenated sequence of data-bins). Arrows indicate the flow from the codestream box to the data-bins and messages, and from the messages to the stream.
+
+**Figure A.1 – Examples of a JPEG 2000 file, JPIP data-bins and JPIP-stream relationships (after G.J. Colyer and R.A. Clark, IEEE Trans. Consumer Electronics, 49 (2003), pp. 850–854)**
+
+Figure A.1 is an illustrative example of the relationship between the bit-streams from a JPEG 2000 file, JPIP data-bins, and a JPIP stream. The figure shows the main header colour coded red, 2 precincts with packets coded in shades of orange-yellow and green, and a meta-data box coded blue. Self-describing JPIP messages are formed from these data-bins and concatenated to form a JPIP stream.
+
+A JPIP stream consists of one or more concatenated JPIP messages. Each JPIP message consists of a header and a body. The header provides descriptive information to identify the relevant data-bin. The body is data from that data-bin. Unless further signalling is provided, the message is the concatenation of the header with the body.
+
+NOTE – In this Recommendation | International Standard, all examples provided form binary messages by the concatenation of header and body. It is implementation-specific to the transport and application if other signalling for header and body is provided. For example, auxiliary signalling with variable error protection might be implemented for wireless-based applications.
+
+## A.2 Message header structure
+
+### A.2.1 General
+
+Each message represents a portion of exactly one data-bin. The message header consists of a sequence of variable-length byte-aligned segments (VBAS). Each VBAS consists of a sequence of bytes, all but the last of which has a most significant bit (bit 7) of 1, as seen in Figure A.2. The least significant 7 bits of each byte in the VBAS are concatenated to form a bit stream which is used in different ways for different VBASs.
+
+![Diagram showing the structure of Variable-Length Byte-Aligned Segments (VBAS). It consists of a sequence of bytes. The first byte has bit 7 as the Most Significant Bit (MSB) and is set to 1. Subsequent bytes have bit 7 set to 1 and are marked with 'X'. The last byte has bit 7 as the Least Significant Bit (LSB) and is set to 0. Ellipses indicate more bytes in between.](09955ff8214ffb6947951fc0f60eb6ab_img.jpg)
+
+|     |   |   |   |   |   |   |   |     |   |     |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
+|-----|---|---|---|---|---|---|---|-----|---|-----|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
+| MSB |   |   |   |   |   |   |   |     |   | LSB |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
+| 7   | 6 | 5 | 4 | 3 | 2 | 1 | 0 | ... | 7 | 6   | 5 | 4 | 3 | 2 | 1 | 0 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
+| 1   | X | X | X | X | X | X | X | ... | 1 | X   | X | X | X | X | X | X | 0 | X | X | X | X | X | X | X |
+
+T.808\_FA.2
+
+Diagram showing the structure of Variable-Length Byte-Aligned Segments (VBAS). It consists of a sequence of bytes. The first byte has bit 7 as the Most Significant Bit (MSB) and is set to 1. Subsequent bytes have bit 7 set to 1 and are marked with 'X'. The last byte has bit 7 as the Least Significant Bit (LSB) and is set to 0. Ellipses indicate more bytes in between.
+
+Figure A.2 – VBAS structure
+
+The message header serves to identify the particular data-bin and byte range which is represented by the message body. Message headers can take an independent form and a dependent form. The independent form is a long form where the message headers are completely self-describing; their interpretation is independent of any other message headers. The optional shorter dependent form message headers make use of information in the headers of previous messages; their decoding is dependent on the previous message. Applications can choose to use the long form message headers; these messages can be rearranged in any arbitrary order. Alternatively, applications can use the shorter form message headers that do depend on previous message headers; these are shorter messages but will create erroneous results if the messages are not arranged in the correct sequence when decoded. It is an application decision whether or not the sequence ordering of received messages can be assumed to be reliable and, if so, whether to make use of the shorter form message headers.
+
+The message header consists of the following VBAS's (optional VBAS's identified by the use of square brackets):
+
+Bin-ID [, Class] [, CSn], Msg-Offset, Msg-Length [, Aux]
+
+The existence of the Class and CSn VBASs are determined by examining the Bin-ID VBAS. The existence of the Aux VBAS is determined by the Class VBAS or the previous Class VBAS, if there is no Class VBAS in the current message header.
+
+The Bin-ID VBAS serves several roles. Bits 6 and 5 of the first byte of the Bin-ID VBAS, labelled 'b' in Figure A.3, indicate whether the Class and CSn VBASs are present in the message header. Table A.1 defines the bit values and its meaning.
+
+Bit 4 of the first byte of the Bin-ID VBAS, labelled 'c' in Figure A.3, indicates whether or not this message contains the last byte in the associated data-bin: '0' means it is not the last byte in the data-bin; '1' indicates that it is the last byte in the data-bin. Receiving a message with this bit set allows determination of the length of the complete data-bin, although it does not imply that the complete JPP-stream or JPT-stream contains sufficient messages to assemble all of the bytes from that data-bin.
+
+The remaining 4 bits of the first byte and the 7 low order bits of any remaining bytes in the Bin-ID VBAS (labelled 'd' in Figure A.3) form an "in-class identifier", which is used to uniquely identify the data-bin within its class, in the manner described in A.2.3.
+
+![Diagram showing the structure of Bin-ID VBAS. It consists of a sequence of bytes. The first byte has bit 7 as the Most Significant Bit (MSB) and contains bits 'a', 'b', 'b', and 'c'. Subsequent bytes have bit 7 as the Least Significant Bit (LSB) and contain bits 'a' and 'd'. Ellipses indicate more bytes in between.](8ed7f57cc317f6574bec781d01ae6ad2_img.jpg)
+
+|     |   |   |   |   |   |   |   |     |   |     |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
+|-----|---|---|---|---|---|---|---|-----|---|-----|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
+| MSB |   |   |   |   |   |   |   |     |   | LSB |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
+| 7   | 6 | 5 | 4 | 3 | 2 | 1 | 0 | ... | 7 | 6   | 5 | 4 | 3 | 2 | 1 | 0 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
+| a   | b | b | c | d | d | d | d | ... | a | d   | d | d | d | d | d | d | a | d | d | d | d | d | d | d |
+
+T.808(22)\_FA.3
+
+Diagram showing the structure of Bin-ID VBAS. It consists of a sequence of bytes. The first byte has bit 7 as the Most Significant Bit (MSB) and contains bits 'a', 'b', 'b', and 'c'. Subsequent bytes have bit 7 as the Least Significant Bit (LSB) and contain bits 'a' and 'd'. Ellipses indicate more bytes in between.
+
+Figure A.3 – Bin-ID VBAS structure
+
+Table A.1 – Bin-ID additional VBAS indication
+
+| Indicator Bits 'bb' | Meaning                                                        |
+|---------------------|----------------------------------------------------------------|
+| 00                  | Prohibited.                                                    |
+| 01                  | No Class or CSn VBAS is present in message header              |
+| 10                  | Class VBAS is present but CSn is not present in message header |
+| 11                  | Class and CSn VBAS are both present in the message header.     |
+
+The Class VBAS, if present, provides a message class identifier. The message class identifier is a non-negative integer, formed by concatenating the least significant 7 bits of each byte of the VBAS in big-endian order. If the Class VBAS is not present, the message class identifier is unchanged from that associated with the previous message. If the Class VBAS is not present and there is no previous message, the message class identifier is 0. Valid message class identifiers are described in A.2.2.
+
+The CSn VBAS, if present, identifies the index (starting from 0) of the codestream to which the data-bin belongs. The codestream index is formed by concatenating the least significant 7 bits of each byte of the VBAS in big-endian order. If the CSn VBAS is not present, the codestream index is unchanged from the previous message. If CSn VBAS is not present and there is no previous message, the codestream index is 0.
+
+The Msg-Offset and Msg-Length VBAS's each represent non-negative integer values, formed by concatenating the least significant 7 bits of each byte in the VBAS in big-endian order. The Msg-Offset integer identifies the offset of the data in this message from the start of the data-bin. The Msg-Length integer identifies the total number of bytes in the body of the message.
+
+An Aux VBAS can be present. Its presence, and meaning if present, is determined by the message class identifier found within the Bin-ID VBAS, as explained in A.2.2. If present, the Aux VBAS represents a non-negative integer value, formed by concatenating the least significant 7 bits of each byte in the VBAS in big-endian order. The information in the Aux VBAS cannot affect the length of the message body.
+
+### A.2.2 Message class identifiers
+
+The message class identifiers defined by this Recommendation | International Standard are the non-negative integers shown in Table A.2. The interpretation of the data-bin classes to which they refer is described in A.3. All other values of message class identifier are reserved, and the associated messages should be skipped by decoders not recognizing the value.
+
+Class identifiers are chosen such that an Aux VBAS is present if and only if the identifier is odd. This property allows unrecognized message headers to be correctly parsed and the contents skipped.
+
+Extended precinct data-bin messages have exactly the same interpretation as non-extended precinct data-bin messages and they refer to exactly the same precinct data-bins. The extended precinct messages include an Aux VBAS which identifies the number of complete packets (quality layers) which would be available for the precinct if the bytes in this message were combined with all previous bytes of the same precinct. If this message also contains the last byte of the data-bin, the Aux VBAS indicates the total number of quality layers associated with the precinct in the original codestream. Otherwise, the Aux VBAS indicates the quality layer to which the byte immediately following the last byte in the message belongs. The information in the Aux VBAS can be useful to certain clients.
+
+Table A.2 – Class identifiers for different data-bin message classes
+
+| Class identifier | Message class                      | Data-bin class       | Stream type         |
+|------------------|------------------------------------|----------------------|---------------------|
+| 0                | Precinct data-bin message          | Precinct data-bin    | JPP-stream only     |
+| 1                | Extended precinct data-bin message | Precinct data-bin    | JPP-stream only     |
+| 2                | Tile header data-bin message       | Tile header data-bin | JPP-stream only     |
+| 4                | Tile data-bin message              | Tile data-bin        | JPT-stream only     |
+| 5                | Extended tile data-bin message     | Tile data-bin        | JPT-stream only     |
+| 6                | Main header data-bin message       | Main header data-bin | JPP- and JPT-stream |
+| 8                | Metadata-bin message               | Metadata-bin         | JPP- and JPT-stream |
+
+Extended tile data-bin messages have exactly the same interpretation as non-extended tile data-bin messages and they refer to exactly the same tile data-bins. The extended tile messages include an Aux VBAS which identifies the smallest  $n$  such that, in all components for which  $(N_L - n)$  is non-negative, resolution level  $(N_L - n)$  and all lower resolution levels
+
+have been completed when the bytes in this message are combined with all preceding bytes of the same tile, where  $N_L$  is the number of decomposition levels, which can vary by component. If no resolution levels of any component have been completed, the value of the Aux VBAS is one plus the maximum value of  $N_L$  across all components. The value zero is reached when all resolutions in all components have been completed. Because resolutions do not necessarily appear in order in a tile, some resolution levels above the value signalled by the VBAS might have been completed, but this cannot be determined from the message header. The information in the Aux VBAS can be useful to certain clients.
+
+### A.2.3 In-class identifiers
+
+The least significant 4 bits of the first byte and the least significant 7 bits of all other bytes from the Bin-ID VBAS are concatenated in big-endian order to form a single word, having  $7k-3$  bits, where  $k$  is the number of bytes in the VBAS. This word represents an unsigned integer which serves to uniquely identify the data-bin within its class and codestream. A.3 provides a description of the various data-bin classes, along with the corresponding in-class identifiers.
+
+## A.3 Data-bins
+
+### A.3.1 Introduction
+
+Data-bins contain portions of a JPEG 2000 file or codestream data. These can be based on imagery elements, such as precinct-based data, tile-based data, and headers. They can also be based on metadata. Whatever the content of a data-bin, each data-bin is treated as an individual bit-stream.
+
+### A.3.2 Precinct data-bins
+
+#### A.3.2.1 Precinct data-bin format
+
+Precinct data-bins appear only within the JPP-stream media-type. Each precinct data-bin corresponds to a single precinct within a single codestream. The in-class identifier is defined by Equation A-1.
+
+$$I = t + (c + s \times \text{num\_components}) \times \text{num\_tiles} \quad (\text{A-1})$$
+
+where:
+
+- $I$  is the unique identifier of the precinct within its codestream;
+- $t$  is the index (starting from 0) of the tile to which the precinct belongs;
+- $c$  is the index (starting from 0) of the image component to which the precinct belongs;
+- $s$  is a sequence number which identifies the precinct within its tile-component.
+
+Within each tile-component, precincts are assigned contiguous sequence numbers,  $s$ , as follows. All precincts of the lowest resolution level (that containing only the LL sub-band samples) are sequenced first, starting from 0, following a raster-scan order. The precincts from each successive resolution level are sequenced in turn, again following a raster-scan order within their resolution level.
+
+It follows that a precinct identifier of 0 refers to the upper left hand precinct from the LL sub-band of image component 0 in tile 0.
+
+Each precinct data-bin corresponds to the string of bytes formed by concatenating all codestream packets, complete with all relevant packet headers, which belong to the precinct. It is conceivable that packet headers will be packed into PPM or PPT marker segments which shall then belong to main header or tile header data-bins, in which case the precinct data-bin would hold only packet bodies. In any event, the precinct data stream should coincide with the contiguous segment of bytes that would be found within a JPEG 2000 codestream having one of the layer-subordinate progression sequences (CPRL, PCRL or RPCL).
+
+NOTE – For the sake of efficiency when serving an image containing PPM markers, a server can transcode the packed packet headers in the main header into the tile headers (PPT markers). Otherwise, a client would require tile-part length markers (TLM) to be sent. The server can alternatively transcode the image (transparently to the client) in such a way as to avoid the use of packed packet headers altogether.
+
+For volumetric images encoded in JP3D (Rec. ITU-T T.809 | ISO/IEC 15444-10), the sequence number of precincts within a tile-component is computed as follows: All precincts of the lowest resolution level, i.e., those containing only the  $[L|X][L|X][L|X]$  samples are sequenced first, starting from zero, following a raster scan order as defined by Rec. ITU-T T.809 | ISO/IEC 15444-10. The precincts from each successive resolution level are sequenced in turn, again following the raster scan order defined by Rec. ITU-T T.809 | ISO/IEC 15444-10. The precinct with sequence number 0 thus refers to the front most, upper left hand precinct of the lowest resolution sub-band of the image component 0 in tile 0.
+
+#### A.3.2.2 Precinct data-bin example (informative)
+
+Figure A.4 shows an example precinct data-bin (in-class identifier 3) with 4 quality layers (or packets).
+
+![Figure A.4 – Example precinct data-bin. The diagram shows a byte stream from 0 to 317. Precinct data-bin 3 is divided into Layer 0 (0-56), Layer 1 (56-136), Layer 2 (136-220), and Layer 3 (220-317). Three cases are shown: (Case A) Message body starts at Offset = 107, Length = 165; (Case B) Message body starts at Offset = 136, Length = 84; (Case C) Message body starts at Offset = 136, Length = 181. A label 'T.808_FA.4' is at the bottom left.](a74294f34a0c736b7ee0f5f0cdca7e28_img.jpg)
+
+Figure A.4 – Example precinct data-bin. The diagram shows a byte stream from 0 to 317. Precinct data-bin 3 is divided into Layer 0 (0-56), Layer 1 (56-136), Layer 2 (136-220), and Layer 3 (220-317). Three cases are shown: (Case A) Message body starts at Offset = 107, Length = 165; (Case B) Message body starts at Offset = 136, Length = 84; (Case C) Message body starts at Offset = 136, Length = 181. A label 'T.808\_FA.4' is at the bottom left.
+
+Figure A.4 – Example precinct data-bin
+
+For Cases A, B and C, the message header is shown below, based on the extended and non-extended precinct data-bin message structures. The underlined data denotes the Aux VBAS to identify the number of layers which are completed by the message.
+
+(Case A)
+
+Non-extended header: 00100011 01101011 10000001 00100101 xxxxxxxx ...
+
+The initial 0 bit indicates only one byte is used in the Bin-ID VBAS. The next two bits ("01") indicate that no Class or CSn VBAS is present. The next "0" bit indicates that the data-bin is not completed by this message. The remaining bits of the first byte ("0011") indicate that the bin-ID is 3. The first bit of the second byte indicates that there is only one byte used in the Msg-Offset VBAS. The next 7 bits ("1101011") mean that the offset is 107. The first bit of the third byte indicates that both this byte and at least the next byte are part of the Msg-Length VBAS. The 0 bit starting the fourth byte indicates that it is the last byte of the Msg-Length VBAS. Thus, all the low order bits from the third and fourth bytes are concatenated to determine the length. In this case, "0000001 0100101" = 165.
+
+Extended header: 01000011 00000001 01101011 10000001 00100101 00000011 xxxxxxxx ...
+
+(Case B)
+
+Non-extended header: 00100011 10000001 00001000 01010100 xxxxxxxx ...
+
+Extended header: 01000011 00000001 10000001 00001000 01010100 00000011 xxxxxxxx ...
+
+(Case C)
+
+Non-extended header: 00110011 10000001 00001000 10000001 00110101 xxxxxxxx ...
+
+Extended header: 01010011 00000001 10000001 00001000 10000001 00110101 00000100 xxxxxxxx ...
+
+Note that since the response data contains the last byte of the data-bin in Case C, the Bin-ID VBAS indicates that it is a "completed" message.
+
+### A.3.3 Tile header data-bins
+
+Tile header data-bins appear only within the JPP-stream media type. For data-bins belonging to this class, the in-class identifier holds the index (starting from 0) of the tile to which the data-bin refers. This data-bin consists of markers and marker segments for tile *n*. It shall not contain an SOT marker segment. Inclusion of SOD markers is optional. This data bin can be formed from a valid codestream, by concatenating all marker segments except SOT in all tile-part headers for tile *n*.
+
+NOTE 1 – POC marker segments can also be removed as they are not of interest to a typical JPIP client. However, a server might include the POC markers for the benefit of a client application that wants to output a JPEG 2000 file with the same progression order as the original image available at the server.
+
+A server may send data in any order, but is required to send a tile header data bin for a tile even if the tile header is empty. A client that receives image data for a tile but has not yet received its tile header should not assume that the tile header is empty and attempt to decode the data.
+
+NOTE 2 – It might be beneficial for certain clients to receive the tile header bin in advance of the tile data bin.
+
+### A.3.4 Tile data-bins
+
+Tile data-bins shall be used only with the JPT-stream media type. For data-bins belonging to this class, the in-class identifier is the index (starting from 0) of the tile to which the data-bin belongs. Each tile data-bin corresponds to the string of bytes formed by concatenating all tile-parts belonging to the tile, in order, complete with their SOT, SOD and all other relevant marker segments.
+
+### A.3.5 Main header data-bin
+
+Both JPP- and JPT-stream media types use the main header data-bin. For data-bins belonging to the codestream main header class (completed or non-completed variations), the in-class identifier shall be 0. This data-bin consists of a concatenated list of all markers and marker segments in the main header, starting from the SOC marker. It contains no SOT, SOD or EOC markers.
+
+### A.3.6 Metadata-bins
+
+#### A.3.6.1 Introduction to metadata-bins
+
+Both JPP- and JPT-stream media types use metadata-bins. Metadata-bins are used to convey metadata from the logical target that contains the codestream or codestreams whose elements can be referenced by other data-bins associated with the JPP-stream or JPT-stream. For the purpose of this Recommendation | International Standard, the term "metadata" refers to any collection of "boxes" from a JPEG 2000 family file. The codestream index shall be ignored in any message which has the metadata-bin class identifier.
+
+Unlike the numerical ID's used for other types of data-bins, metadata-bin ID's do not map algorithmically to some file format construct or byte offset. The server is free to choose any numeric ID for any particular metadata bin. The one and only exception to this is that the metadata-bin containing the root of the logical target shall be assigned ID 0.
+
+NOTE 1 – The mechanism for assignment is implementation-dependent; however, it is an informative suggestion that servers assign bin-ID's using consecutive numbers.
+
+A server is required to send at least the metadata bin with bin ID 0, even if no metadata is present. In this case, the metabin #0 will be empty. A client should not assume that no metadata is available if it has not yet received any metadata bin.
+
+NOTE 2 – It might be beneficial for certain clients to receive the metadata bin with bin ID 0 in advance of all other bins.
+
+#### A.3.6.2 Division of a logical target containing a JPEG 2000 file into metadata-bins
+
+All metadata could conceivably be included in metadata-bin 0. In this case, all boxes from the logical target would belong to metadata-bin 0, appearing in their original order. Since JPEG 2000 family file formats consist of nothing but a sequence of boxes, this effectively means that metadata-bin 0 would consist of the entire logical target. More generally, however, it is useful to break the logical target into pieces that can be transmitted in a manageable fashion. This allows image servers to deliberately omit portions of the logical target that are not currently required by a client. To this end, JPIP defines a new special box type, known as the "Placeholder box." The Placeholder box serves to identify the size and type of a box from the logical target, while pointing to another data-bin that holds that box's contents. Placeholders are also able to represent codestreams from the logical target. This is particularly significant in view of the fact that the compressed data represented by any given codestream can be delivered incrementally via the other data-bin types (header data-bins and precinct data-bins or tile data-bins).
+
+Formally, metadata-bin 0 consists of all boxes from the logical target, appearing in their original order, with the exception that a placeholder can replace any given box. The Placeholder box contains the original header of the box that has been replaced, together with the identifier of the metadata-bin that holds that box's contents, not including the header itself. Every metadata-bin, other than metadata-bin 0, shall consist of the contents of some box, whose header appears in the placeholder that references that data-bin. These box contents can themselves include sub-boxes, any of which might be replaced by further placeholders.
+
+The following colour scheme will be used for metadata-bin example illustrations (Figure A.5):
+
+![Figure A.5: Metadata-bin example colour scheme. A diagram showing a 'Metadata-bin' container divided into three horizontal sections: 'Complete boxes (including box headers)' in light yellow, 'Box contents (no box headers)' in light orange, and 'Placeholder boxes (replacing the original box from the file)' in light orange.](b0d322b2e75c75e1f21bfc0df841beaa_img.jpg)
+
+| Metadata-bin                                                 |
+|--------------------------------------------------------------|
+| Complete boxes (including box headers)                       |
+| Box contents (no box headers)                                |
+| Placeholder boxes (replacing the original box from the file) |
+
+T.808\_FA.5
+
+Figure A.5: Metadata-bin example colour scheme. A diagram showing a 'Metadata-bin' container divided into three horizontal sections: 'Complete boxes (including box headers)' in light yellow, 'Box contents (no box headers)' in light orange, and 'Placeholder boxes (replacing the original box from the file)' in light orange.
+
+Figure A.5 – Metadata-bin example colour scheme
+
+As an example, consider a simple JP2 file with the following box structure (Figure A.6):
+
+![Figure A.6: A sample JP2 file box structure. It shows a vertical stack of boxes: 'jp' box, 'ftyp' box, 'jp2h' box, 'ihdr' box, 'colr' box, 'xml' box, and 'jp2c' box. The 'jp2h' box contains the 'ihdr', 'colr', and 'xml' boxes. The label 'T.808_FA.6' is to the right.](a149b400127a3e3e50b3c98d27c5935c_img.jpg)
+
+|            |
+|------------|
+| 'jp' box   |
+| 'ftyp' box |
+| 'jp2h' box |
+| 'ihdr' box |
+| 'colr' box |
+| 'xml' box  |
+| 'jp2c' box |
+
+T.808\_FA.6
+
+Figure A.6: A sample JP2 file box structure. It shows a vertical stack of boxes: 'jp' box, 'ftyp' box, 'jp2h' box, 'ihdr' box, 'colr' box, 'xml' box, and 'jp2c' box. The 'jp2h' box contains the 'ihdr', 'colr', and 'xml' boxes. The label 'T.808\_FA.6' is to the right.
+
+Figure A.6 – A sample JP2 file
+
+This file can be divided up into three metadata-bins: one to represent the top-level of the original file (data-bin 0); one to represent the JP2 Header box; and one to represent the codestream. This division is shown in Figure A.7.
+
+While the contents of any metadata-bin shall be the contents of the box or file represented by that bin, the actual data contained in those contents can conceptually vary depending on the type of box. For example, Metadata-bin 1 in Figure A.7 represents the contents of the JP2 Header box. The contents of that box is a sequence of other complete boxes, as the JP2 Header box is a superbox. By contrast, the data inside Metadata-bin 2 is the raw contents of the Contiguous Codestream box, with no box headers, because that box is not a superbox.
+
+One point of particular interest to note from the example in Figure A.7 is that access to codestream data can be provided in two ways. The second placeholder bin is used to replace the contiguous codestream box (jp2c) in the original file. It identifies metadata-bin 2 as holding the original contents of this box, i.e., the raw codestream itself. For convenience of description in this Recommendation | International Standard, this shall be termed the "raw codestream" representation. Raw codestreams are served from metadata-bins.
+
+![Figure A.7: A sample JP2 file divided into three metadata-bins. Metadata-bin 0 contains 'jp' box, 'ftyp' box, a placeholder for 'jp2h' box (pointing to Metadata-bin 1), a placeholder for 'jp2c' box (pointing to Metadata-bin 2), and vertical dots. Metadata-bin 1 contains 'ihdr' box, 'colr' box, and 'xml' box. Metadata-bin 2 contains 'jp2c' box contents. The label 'T.808_FA.7' is to the right.](e29665b8abcea967ef289c6aff07ae4c_img.jpg)
+
+|                                                                                  |                |                     |
+|----------------------------------------------------------------------------------|----------------|---------------------|
+| Metadata-bin 0                                                                   | Metadata-bin 1 | Metadata-bin 2      |
+| 'jp' box                                                                         | 'ihdr' box     | 'jp2c' box contents |
+| 'ftyp' box                                                                       | 'colr' box     |                     |
+| Placeholder for 'jp2h' box:<br>original 'jp2h' box header<br>metadata-bin ID = 1 | 'xml' box      |                     |
+| Placeholder for 'jp2c' box:<br>original 'jp2c' box header<br>metadata-bin ID = 2 |                |                     |
+| ⋮                                                                                |                |                     |
+
+T.808\_FA.7
+
+Figure A.7: A sample JP2 file divided into three metadata-bins. Metadata-bin 0 contains 'jp' box, 'ftyp' box, a placeholder for 'jp2h' box (pointing to Metadata-bin 1), a placeholder for 'jp2c' box (pointing to Metadata-bin 2), and vertical dots. Metadata-bin 1 contains 'ihdr' box, 'colr' box, and 'xml' box. Metadata-bin 2 contains 'jp2c' box contents. The label 'T.808\_FA.7' is to the right.
+
+Figure A.7 – A sample JP2 file divided into three metadata-bins
+
+The placeholder can also provide a codestream identifier. Any data-bins belonging to the main header, tile header, precinct or tile data-bin classes, having this same codestream identifier, convey compressed data associated with the same codestream as that found in metadata-bin 2. For convenience of description in this Recommendation | International Standard, this shall be termed the "incremental codestream" representation. Incremental codestreams are served from these data-bins.
+
+In general, placeholders that reference codestream data can do so either by referencing a separate metadata-bin (raw codestream), or by providing a codestream identifier (incremental codestream), or both. Even if both methods are provided, the JPP-stream or JPT-stream data available at a client or image-rendering agent might only have the contents of the raw codestream, or only have data from the incremental codestream. Moreover, if both the raw and incremental versions of the same codestream are available, there is no guarantee that the two representations will have compatible coding parameters. Only the reconstructed image samples associated with the two representations are guaranteed to be consistent.
+
+It is also possible to use Placeholder boxes to associate multiple codestreams with a single original box. The interpretation of such an association is dependent upon the box being replaced. Further discussion of this topic appears in A.3.6.4.
+
+In the simple example of Figure A.7, Placeholder boxes appear only at the top-level of the file, in metadata-bin 0. As already noted, however, placeholders can be used to replace any box, in any metadata-bin. This allows complex files to be decomposed in hierarchical fashion. As such, a single original file can be encapsulated in a variety of different metadata-bin structures, depending on how placeholders are used. **However, a single JPP-stream or JPT-stream shall adopt only one such encapsulation.** In client-server applications, the server will generally determine a suitable metadata-bin structure for the file, assigning a unique identifier to the resulting stream, and using the same metadata-bin structure in all communication with all clients which reference this same unique identifier.
+
+When a placeholder relocates a box into a new metadata-bin, the header of that box (LBox, TBox and XLBox fields) is stored, unmodified, in the Placeholder box. If a client or rendering agent needs to map particular boxes to their original file offsets, it can do so using the original box headers that appear in the Placeholder boxes. This information ultimately allows any location in the original file to be mapped to a particular location in a particular metadata-bin, if the contents of that data-bin exist. This is important since some JPEG 2000 family files contain boxes that reference other boxes through their location within the file.
+
+While considerable freedom exists in deciding how best to divide a file into metadata-bins, there is one restriction. Any Placeholder box that appears within a metadata-bin shall replace a top-level box within that data-bin. Equivalently, wherever a sub-box is to be replaced with a placeholder, its immediate containing super-box shall reside within its own metadata-bin. For example, in the sample file shown in Figure A.6, the XML data contained within the JP2 Header box can be placed in a separate data bin from the other boxes. This allows a server to deliver only those data-bins that are actually required for decoding and display of the image, unless XML data is explicitly requested. A suitable data-bin structure is shown in Figure A.8.
+
+![Figure A.8: A diagram showing a valid division of a file into metadata-bins. Metadata-bin 0 contains 'jp' box, 'ftyp' box, and two placeholders: one for 'jp2h' box (original 'jp2h' box header, metadata-bin ID = 1) and one for 'jp2c' box (original 'jp2c' box header, metadata-bin ID = 2). Metadata-bin 1 contains 'ihdr' box, 'colr' box, and the 'xml' box contents. Metadata-bin 2 contains the 'jp2c' box contents. Metadata-bin 3 contains the 'xml' box contents. Arrows indicate that the 'jp2h' placeholder in bin 0 points to the 'xml' box contents in bin 3, and the 'jp2c' placeholder in bin 0 points to the 'jp2c' box contents in bin 2.](759c7d62402f0b4651ddce292be5bdef_img.jpg)
+
+Figure A.8: A diagram showing a valid division of a file into metadata-bins. Metadata-bin 0 contains 'jp' box, 'ftyp' box, and two placeholders: one for 'jp2h' box (original 'jp2h' box header, metadata-bin ID = 1) and one for 'jp2c' box (original 'jp2c' box header, metadata-bin ID = 2). Metadata-bin 1 contains 'ihdr' box, 'colr' box, and the 'xml' box contents. Metadata-bin 2 contains the 'jp2c' box contents. Metadata-bin 3 contains the 'xml' box contents. Arrows indicate that the 'jp2h' placeholder in bin 0 points to the 'xml' box contents in bin 3, and the 'jp2c' placeholder in bin 0 points to the 'jp2c' box contents in bin 2.
+
+T.808\_FA.8
+
+Figure A.8 – A superbox with a referenced metadata-bin
+
+It would not be valid, however, for the JP2 Header box to be left in metadata-bin 0, as shown in Figure A.9:
+
+![Figure A.9: A diagram showing an invalid division of a file into metadata-bins. Metadata-bin 0 contains 'jp' box, 'ftyp' box, 'jp2h' box, 'ihdr' box, 'colr' box, and two placeholders: one for 'xml' box (original 'xml' box header, metadata-bin ID = 1) and one for 'jp2c' box (original 'jp2c' box header, metadata-bin ID = 2). Metadata-bin 1 contains the 'xml' box contents. Metadata-bin 2 contains the 'jp2c' box contents. Arrows indicate that the 'xml' placeholder in bin 0 points to the 'xml' box contents in bin 1, and the 'jp2c' placeholder in bin 0 points to the 'jp2c' box contents in bin 2. A large red prohibition sign is placed over the diagram, indicating this division is invalid. Text next to the sign states: 'This division of the file is not permitted. If the XML box is to be separated into its own metadata-bin, the JP2 Header box ('jp2h') must also be separated into its own metadata-bin'.](9ee1a10ae91d4878e24b2e7dbaa95c2e_img.jpg)
+
+Figure A.9: A diagram showing an invalid division of a file into metadata-bins. Metadata-bin 0 contains 'jp' box, 'ftyp' box, 'jp2h' box, 'ihdr' box, 'colr' box, and two placeholders: one for 'xml' box (original 'xml' box header, metadata-bin ID = 1) and one for 'jp2c' box (original 'jp2c' box header, metadata-bin ID = 2). Metadata-bin 1 contains the 'xml' box contents. Metadata-bin 2 contains the 'jp2c' box contents. Arrows indicate that the 'xml' placeholder in bin 0 points to the 'xml' box contents in bin 1, and the 'jp2c' placeholder in bin 0 points to the 'jp2c' box contents in bin 2. A large red prohibition sign is placed over the diagram, indicating this division is invalid. Text next to the sign states: 'This division of the file is not permitted. If the XML box is to be separated into its own metadata-bin, the JP2 Header box ('jp2h') must also be separated into its own metadata-bin'.
+
+T.808\_FA.9
+
+Figure A.9 – An invalid division of the file into metadata-bins
+
+An equivalent way to express this same restriction is as follows. Wherever a placeholder replaces a sub-box, a placeholder shall also replace its containing box. This restriction ensures that it is always possible for a client or rendering agent to recover the lengths and locations of the original boxes within the file, even if some of the boxes are not understood by the client.
+
+In addition to providing the original contents of a box in a separate metadata-bin, JPP- and JPT-streams are also permitted to provide alternate representations of the box, which did not explicitly appear within the original file. These alternate representations are known as "stream equivalents." For example, the original file might contain a Cross-reference box whose fragment list box collects one or more fragments of the file to reconstitute a Colourspace Specification box. While a client or rendering agent should be able to follow the relevant file pointers to reconstruct the Colourspace Specification box, a more convenient JPP- or JPT-stream representation might contain a placeholder which references a data-bin containing the reconstructed Colourspace Specification box as a stream equivalent. To do this, the placeholder includes a box header for the stream equivalent, together with the identifier of the metadata-bin that holds the contents of the stream equivalent box.
+
+The following example (shown in Figure A.10) illustrates the use of stream equivalents for Cross-reference boxes. In this case, the data-bin that holds the stream-equivalent contents is also referenced as holding the original contents of another box. While this is likely to be a common situation where the original file contained cross-reference boxes, there is no need for the stream-equivalent to point to a metadata-bin that is connected to the original file hierarchy. The stream equivalent box's contents can be created from scratch or they can refer to content which originally existed within other files. This allows Cross-reference boxes whose fragment list references other files or URLs to be fully encapsulated within a single JPP- or JPT-stream.
+
+Stream equivalents can be used in any situation where the server can create an alternate form of the contents of a box that provide some benefit to the client; they are not just for providing access to explicitly cross-referenced data.
+
+In addition to pointing to actual or equivalent box data, a placeholder box can point to one or more codestreams where the replaced box is equivalent to those codestreams. For example, the Contiguous Codestream box can be replaced by a placeholder box that references the ID of the incremental codestream contained within that Contiguous Codestream box. Another example would be to replace the Chunk Offset box in a Motion JPEG 2000 file with a placeholder that specifies an array of codestream ID's. Those codestream ID's refer to the codestreams that are pointed to by the Chunk Offset box.
+
+![Diagram illustrating the use of stream equivalents for Cross-reference boxes across four metadata-bins.](f0a97d0d3818a253c1d2a009966081b1_img.jpg)
+
+The diagram shows four metadata-bins and their internal structure and references:
+
+- Metadata-bin 0:** Contains 'jp' box, 'ftyp' box, 'jp2h' box, and two placeholders for 'jplh' boxes. The first placeholder points to Metadata-bin 1 (ID=1), and the second points to Metadata-bin 2 (ID=2).
+- Metadata-bin 1:** Contains 'lbl' box and a placeholder for 'cgrp' box. The placeholder points to Metadata-bin 3 (original 'cgrp' box header, metadata-bin ID = 3).
+- Metadata-bin 2:** Contains 'lbl' box and a placeholder for 'cref' box. The placeholder points to Metadata-bin 4 (original 'cref' box header, metadata-bin ID = 4, stream-equivalent 'cgrp' box header, metadata-bin ID = 3).
+- Metadata-bin 3:** Contains 'cgrp' box contents.
+- Metadata-bin 4:** Contains 'cref' box contents: file offset.
+
+Arrows indicate the flow of references: from Metadata-bin 0 to 1 and 2; from Metadata-bin 1 to 3; from Metadata-bin 2 to 4; and from Metadata-bin 4 to 3.
+
+T.808\_FA.10
+
+Diagram illustrating the use of stream equivalents for Cross-reference boxes across four metadata-bins.
+
+Figure A.10 – Example of the use of stream equivalents
+
+#### A.3.6.3 Placeholder box format
+
+Figure A.11 shows the format of a Placeholder box, including the box header (unlike the definition of most boxes in Annex I and other parts of this Recommendation | International Standard); it is specified this way to emphasise that the use of the length field in the box header for a Placeholder box is more restrictive than for other boxes.
+
+![Figure A.11 – Placeholder box structure. A diagram showing the structure of a Placeholder box. The box is divided into fields: LBox, TBox, Flags, OrigID, OrigBH, EquivID, EquivBH, CSID, NCS, and an ellipsis. Below the fields, arrows indicate the minimal placeholder box and various extensions.](5414f65867392f05ba0063b208eeb5e1_img.jpg)
+
+| LBox                                                            | TBox | Flags | OrigID | OrigBH | EquivID | EquivBH | CSID | NCS | ... |
+|-----------------------------------------------------------------|------|-------|--------|--------|---------|---------|------|-----|-----|
+| Minimal placeholder box                                         |      |       |        |        |         |         |      |     |     |
+| Minimal placeholder box with a stream equivalent representation |      |       |        |        |         |         |      |     |     |
+| Minimal placeholder box with an associated single codestream    |      |       |        |        |         |         |      |     |     |
+| Minimal placeholder box with multiple associated codestreams    |      |       |        |        |         |         |      |     |     |
+| Possible future extensions                                      |      |       |        |        |         |         |      |     |     |
+
+T.808\_FA.11
+
+Figure A.11 – Placeholder box structure. A diagram showing the structure of a Placeholder box. The box is divided into fields: LBox, TBox, Flags, OrigID, OrigBH, EquivID, EquivBH, CSID, NCS, and an ellipsis. Below the fields, arrows indicate the minimal placeholder box and various extensions.
+
+Figure A.11 – Placeholder box structure
+
+**LBox:** This is the standard 4-byte big-endian length field for a box. The value shall not be 1 for a Placeholder box, meaning that the XLBox field shall not be present.
+
+**TBox:** This is the standard 4-byte box type field for a box. The type value for a Placeholder box shall be 'phld' (0x7068 6c64).
+
+**Flags:** This field specifies what elements of the Placeholder box contain valid data. This field is encoded as a 4-byte big-endian integer. Valid values for the Flags field are specified in Table A.3.
+
+**OrigID:** This field specifies the metadata-bin ID of the bin containing the contents of the original box represented by this Placeholder box. It is encoded as an 8-byte big-endian unsigned integer.
+
+**OrigBH:** This field specifies the original header (LBox, TBox and XLBox, as needed) of the original box referenced by this Placeholder box. The length of this field is 8 bytes if the original box header's LBox field is not equal to 1 and 16 bytes otherwise.
+
+**EquivID:** This field specifies the metadata-bin ID of the bin that contains a stream-equivalent form of the contents of this box. This field is encoded as an 8-byte big-endian unsigned integer.
+
+**EquivBH:** This field specifies the header of the stream-equivalent box (LBox, TBox and XLBox as needed) of the box referenced by this Placeholder box. The length of this field is 8 bytes if the equivalent box header's LBox field is not equal to 1 and 16 bytes otherwise.
+
+**CSID:** This field specifies the ID of the first codestream associated with the replaced box. This is the ID that is associated with all header, precinct and/or tile data-bins used to incrementally communicate the contents of the first codestream associated with the replaced box. This field is encoded as an 8-byte big-endian unsigned integer.
+
+**NCS:** This field specifies the number of codestreams in the array of codestreams that is equivalent to the replaced box. The codestream ID values of these codestreams run contiguously from the value specified by the CSID field. This field is encoded as a 4-byte big-endian unsigned integer.
+
+**ExtendedBoxList:** This field is not specifically shown in Figure A.11. The NCS field may be followed by a sequence of boxes containing extended information from the server. The existence of any box following the NCS field shall be specified through a bit in the Flags field. However, no extended boxes, nor any additional bit flags, are defined by this Recommendation | International Standard. Clients shall ignore any box in ExtendedBoxList that is not understood.
+
+A bit value of "x" in Table A.3 indicates that the specified value includes cases where that bit is set to either "1" or "0". Bits indicated as "y" are unused by this standard and shall be set to 0 by servers and ignored by clients.
+
+Not all of the fields defined for a Placeholder box need appear in every Placeholder box. As suggested by the arrows in Figure A.11, if no box equivalent or incremental codestream ID is provided, the box may be terminated at the end of the OrigBH field. Similarly, if no incremental codestream ID is provided, the box may be terminated at the end of the EquivBH field, and if no more than one incremental codestream ID is provided, the box may be terminated at the end of the CSID field.
+
+The above definition implies that the placeholder box can be truncated after the last used field, but intermediate fields need to be present, even if unused.
+
+**Table A.3 – Valid values for the Flags field of a Placeholder box**
+
+| Value                                   | Meaning                                                                                                                                                                                                                                                                        |
+|-----------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| yyyy yyyy yyyy yyyy yyyy yyyy yyyy xxx1 | Access is provided to the original contents of this box through the metadata-bin specified in the OrigID field                                                                                                                                                                 |
+| yyyy yyyy yyyy yyyy yyyy yyyy yyyy xxx0 | No access is provided to the original contents of this box, and the value of the OrigID field shall be ignored                                                                                                                                                                 |
+| yyyy yyyy yyyy yyyy yyyy yyyy yyyy xx1x | A stream-equivalent box is provided, whose contents are in the metadata-bin specified by the EquivID field.                                                                                                                                                                    |
+| yyyy yyyy yyyy yyyy yyyy yyyy yyyy xx0x | No stream-equivalent box is provided, and the value of any EquivID and EquivBH fields shall be ignored                                                                                                                                                                         |
+| yyyy yyyy yyyy yyyy yyyy yyyy yyyy 01xx | Access to the image represented by this box is provided by a single incremental codestream, which is identified by the CSID field. The value of the NCS field shall be treated as if it was set to "1" regardless of the actual value of that field when the field is present. |
+| yyyy yyyy yyyy yyyy yyyy yyyy yyyy 11xx | Access to the image represented by this box is provided by one or more incremental codestreams, as specified by the CSID and NCS fields.                                                                                                                                       |
+| yyyy yyyy yyyy yyyy yyyy yyyy yyyy x0xx | This placeholder does not provide access to an image representing the original box as an incremental codestream; the CSID and NCS fields shall be ignored.                                                                                                                     |
+| Other values                            | Reserved for ISO use                                                                                                                                                                                                                                                           |
+
+#### A.3.6.4 Referencing of incremental codestreams with placeholders
+
+Wherever header, precinct or tile data bins exist, their codestream ID shall appear in a Placeholder box within an appropriate metadata bin. The only exception to this requirement is for unwrapped JPEG 2000 codestreams, which are not embedded within a JPEG 2000 family file format.
+
+The codestream ID values that appear within the relevant Placeholder box shall conform to any requirements imposed by the containing file format. For example, JPX files formally assign a sequence number to codestreams that are found in Contiguous Codestream boxes or Fragment Table boxes, either at the top level of the file, or within Multiple Codestream boxes. The first codestream in the logical target shall have a codestream ID of 0; the next shall have a codestream ID of 1; and so forth.
+
+Placeholders that reference multiple codestream IDs can only be used where the meaning of those codestreams is well defined by the type of the box that is being replaced. For JPX files, Contiguous Codestream boxes, Fragment Table boxes and Multiple Codestream boxes can be replaced by Placeholder Boxes that specify codestream IDs. Placeholders replacing Contiguous Codestream boxes and Fragment Table boxes can only specify a single codestream ID, while a placeholder replacing a Multiple Codestream box can specify multiple codestream IDs, corresponding to the number of codestreams that are found within the box.
+
+#### A.3.6.5 Using Placeholder boxes with MJ2 and J2KS files
+
+This Recommendation | International Standard defines only two box types suitable for placeholders with Motion JPEG 2000 (MJ2) files or J2KS files. Specifically, either the chunk offset box ('stco') or the chunk large offset box ('co64') can be replaced by a Placeholder box which identifies multiple codestream ID's.
+
+Each video track in an MJ2 file contains exactly one chunk offset box (either 'stco' or 'co64') that, in combination with the sample to chunk box ('stsc'), serves to identify the locations of all of the contiguous codestream boxes that belong to the video track. If the chunk offset box is replaced by a placeholder that provides one or more codestream ID's, there shall be exactly one codestream ID for each contiguous codestream box in the video track. If the visual sample entry box identifies a field count of 2, there shall be  $2N$  codestream ID's in the range provided by the Placeholder box, where  $N$  is the number of video samples (i.e.,  $N$  is the number of frames). Otherwise, there shall be only  $N$  codestream ID's in the range provided by the Placeholder box. The codestream ID's shall be sequenced by sample number (frame number) and by field number within each sample.
+
+NOTE – For MJ2 files in a JPP-stream or a JPT-stream representation, there is no need for the stream to contain the contents of the original chunk offset box, the sample to chunk box ('stsc'), or the sample size box ('stsz'). This indexing information can be regenerated if needed if the stream representation is converted to an MJ2 file.
+
+#### A.3.6.6 Using Placeholder boxes with J2KI files
+
+As specified in Rec. ITU-T T.815 | ISO/IEC 15444-16, JPEG 2000 codestreams can be encapsulated as individual images or image collections within ISO/IEC 23008-12 files conforming to the 'j2ki' brand.
+
+Individual images are encapsulated as *items*, as specified in Rec. ITU-T T.815 | ISO/IEC 15444-16. Incremental codestreams for all such items can be provided by replacing the Item Location Box with a Placeholder box which identifies
+
+one or multiple codestream ID's, as appropriate. If present, the Placeholder box's NCS field shall be equal to the number of items with type 'j2k1'. If the Placeholder box has no NCS field, then the number of items with type 'j2k1' shall be exactly 1. Incremental codestream IDs described by the Placeholder box, starting from CSID, shall correspond to the items that have type 'j2k1', in increasing order of their Item ID values.
+
+## A.4 Conventions for parsing and delivery of JPP-streams and JPT-streams
+
+Placeholder boxes create additional flexibility and some potential ambiguity for both clients and servers in how they parse or deliver JPP- and JPT-streams. A server can choose to partition original boxes from a JPEG 2000 family file into metadata-bins using any of a wide range of strategies, by introducing Placeholder boxes at appropriate points. The server shall do this in a consistent way so that the data-bins associated with a JPP- or JPT-stream have the same nominal contents for all clients which access the same logical target (possibly qualified by a unique target ID), whenever they access it.
+
+More significantly, however, Placeholder boxes allow servers to construct a single JPP- or JPT-stream whose data-bins provide multiple alternate representations of the same original content. This can happen when a streaming equivalent is identified within a placeholder, and/or when an incremental codestream ID is identified within a placeholder. In these cases, an original box might be made available in a metadata-bin, while also being made available as a stream equivalent in yet another metadata-bin, and/or also being made available as an incremental codestream via header, precinct or tile data-bins. While servers might distribute the contents of all data-bins that represent an original box, for efficiency reasons servers would be expected to distribute only sufficient information to convey the original content, unless explicitly asked to distribute redundant data-bins. Client-side parsers of JPP- or JPT-streams, when confronted with multiple representations of an original box, might choose to ignore all but one of the representations. The expected client convention should have a significant impact on which metadata-bins the server chooses to actually send to a client.
+
+In view of this, the following server behaviour is recommended:
+
+- Unless a server advertises or has reason to believe otherwise, it should assume that the client parser will parse a stream equivalent box in preference to the original box if the presence of both box types has been signalled to the client by placeholders.
+- Unless a server advertises or has reason to believe otherwise, it should assume that the client parser will use the incremental codestream representation (header, precinct or tile data-bins) in preference to a raw codestream if the presence of both box types has been signalled to the client by placeholders.
+
+See Annex J for further guidance regarding expected server behaviour.
+
+## A.5 Conventions for JPP-stream or JPT-stream interoperability (informative)
+
+This convention describes the exchange file format for JPP-stream and JPT-stream, herein termed jpp-file and jpt-file respectively. Such a file can contain the received JPEG 2000 data from a JPIP session (the client's cache for example), or a subset thereof. It is possible for another JPIP client to read and use this file because JPP-stream and JPT-stream are self-describing media types.
+
+These files are formed by concatenation of JPT-stream or JPP-stream messages. For example, they can be formed by the simple concatenation of all such messages received by a client in a single session or from multiple sessions. An improved situation would be where clients generated a valid JPT-stream or JPP-stream using a single Message Header and Message per data-bin.
+
+It is recommended that the ".jpp" and ".jpt" extensions be used for these files and, if appropriate, that the file name includes a reference to a relevant JPIP `target` token or `target-id` token.
+
+This convention does not specify the implementation or structure of the cache for a client. For example, a client might use a database to serve as its implementation of the cache function rather than a file-based cache system.
+
+# Annex B
+
+## Sessions, channels, cache model and model-sets
+
+(This annex forms an integral part of this Recommendation | International Standard.)
+
+## B.1 Requests within a session vs. stateless requests
+
+The JPIP protocol makes a clear distinction between two different types of requests: stateless requests and requests which belong to a session.
+
+The purpose of sessions is to reduce the amount of explicit communication required between the client and server. Within a session, the server is expected to remember client capabilities and preferences supplied in previous requests so that this information need not be sent in every request. Even more importantly, the server may keep a log of data it knows the client to have received so that this information need not be re-transmitted in response to future requests. This log is subsequently referred to as the cache model. The cache model would typically be persistent for the duration of a session. Unless explicitly instructed otherwise, the server may assume that the client caches all data it receives within a session, and may model the client's cache, sending only those portions of the compressed image data or metadata which the client does not already have in its cache.
+
+Stateless requests are not associated with any session and so shall be entirely self-contained. It should be noted that the term "stateless" applies only to the server, not the client. As for sessions, the client should generally cache the responses from previous requests associated with the same logical target. Clients that issue multiple stateless requests for the same target should generally include information about their cache contents with each request, so as to avoid the transmission of redundant data. Thus, the benefits of sessions are smaller, less complex requests and/or less redundant response data from the server. The benefit of stateless communication is that the server need not maintain state information between requests; this means that the same host need not ultimately serve all requests for a single target image that emanate from a single client.
+
+## B.2 Channels and sessions
+
+Associated with each session are the following elements:
+
+- One or more logical targets (usually image files), whose content does not change over the session.
+- A single image data return type for each logical target associated with the session.
+- For each logical target associated with the session, a model of the client's cache contents shall be maintained wherever the data return type is one of "jpp-stream" or "jpt-stream". However, this model need not perfectly reflect the actual state of the client's cache. Rules governing the maintenance of cache models are outlined in B.3.
+- One or more JPIP channels. Clients may generally open multiple channels within the same session. Each JPIP channel may be associated with a separate underlying transport channel (e.g., a separate TCP connection), although this might not be the case. Multiple channels allow clients to issue simultaneous requests for multiple image regions, with the expectation that the server will respond to these requests concurrently. Channels also allow for intelligent bandwidth allocation amongst different types of requests either within a single target image or across multiple targets.
+- Where multiple channels are associated with the same logical target, the session cache model applies across all channels. Multiple clients may open JPIP channels within the same session, although this might have undesirable side effects if the channels refer to the same logical target.
+
+Associated with each channel are the following elements:
+
+- A single logical target (usually an image file).
+- A server-assigned identifier that shall be included with each request. JPIP does not define a separate session identifier, since the channel identifier is sufficient to associate the request with its session.
+- A record of the client's capabilities and preferences, which can be adjusted through appropriate request fields.
+- To the extent that the server queues requests, it should provide a separate queue for each JPIP channel.
+
+There is a one-to-one correspondence for the client request and client response on a channel. Different JPIP channels can be on the same transport channel or on different transport channels. Requests that use different JPIP channels can arrive asynchronously at the server if separate transport channels are used to transport the requests. Responses that use different JPIP channels can arrive asynchronously at the client if separate transport channels are used to transport the responses. Servicing of multiple channels is at the discretion of the server; however, the delivery rate request field and the max bandwidth and bandwidth slice preferences should guide the server.
+
+## B.3 Cache model management
+
+As already noted, one of the principal functions of a session is that of server-side modelling of the client's cache. Unless explicitly informed otherwise, the server **may** assume that the client has cached all information sent in response to requests within the session: this information **need not** be re-transmitted. However, that the server is not obliged to maintain a complete cache model or indeed any cache model at all: redundant data **may** be transmitted in response to requests.
+
+In addition to the impact of transmitted data, explicit cache model manipulation statements in client requests can update the server's cache model. These statements are to be processed before determining the data that should be returned to the client in response to its request. There are two types of cache model manipulation statements: additive and subtractive.
+
+Additive cache model manipulation statements serve to augment the server's cache model, adding data-bins, or portions of data-bins to the existing model. These provide a mechanism for a client to inform the server about information which it received in a previous session, or using previous stateless requests. A server **should** attempt to exploit any additive cache model manipulation statements that appear in client requests. However, servers are not obliged to maintain a complete cache model, so a server may disregard, or partially disregard, additive cache model manipulation statements.
+
+Subtractive statements serve to remove data-bins, or portions of data-bins from the server's cache model. A client might issue subtractive cache model manipulation statements in order to inform the server that it has not cached or has discarded some data which was previously sent by the server. The server is otherwise free to assume that the client has cached all data transmitted during the session. The server **shall** remove all information identified by a subtractive cache model statement from any cache model (complete or otherwise) that it is maintaining.
+
+Session-based JPIP requests have side effects, which might affect the response to future requests. This is true also of requests that contain cache model manipulation statements – the effects of cache model manipulation are persistent. Moreover, the side effects of a request arriving on one JPIP channel are reflected in the response to any requests that might belong to a different JPIP channel which is associated with the same logical target. This follows from the fact that there is only one cache model for each logical target in a session.
+
+## B.4 Interrogation and manipulation of model-sets
+
+Where a logical target associated with a session contains a large number of codestreams (e.g., a video target), or a client remains connected for a long period of time, partial cache modelling becomes an increasingly likely strategy for practical server implementations. It also becomes increasingly likely that clients will be unable to cache all information sent by the server. To avoid communication inefficiencies in such circumstances, the concept of an "mset" (model-set) is introduced. The "mset" is the collection of codestreams for which client cache contents are being modelled by the server.
+
+In any request, the client can instruct the server to limit its "mset" to a particular set of codestreams. This provides a convenient mechanism for clients to discard whole codestreams from their cache without running the risk that the server will generate incomplete responses to future requests for those codestreams.
+
+"mset" requests also result in server responses which indicate the actual set of codestreams for which cache model information is being maintained. This allows clients to determine whether or not cache model manipulation statements which refer to a variety of codestreams will be disregarded by the server.
+
+In the absence of any explicit "mset" manipulation or interrogation, the client may assume only that the server's "mset" includes all codestreams for which response data is generated to its request. Since servers generally have the right to limit the scope of a client's request to a smaller number of codestreams than the number which was originally specified, there is no guarantee that the server's "mset" will include all of the codestreams mentioned in a request, unless the request mentioned only one codestream. These matters are explained further in C.8.6.
+
+# Annex C
+
+## Client request
+
+(This annex forms an integral part of this Recommendation | International Standard.)
+
+## C.1 Request syntax
+
+### C.1.1 Introduction
+
+This annex describes all possible elements in a JPIP request. Each major subclause describes a group of fields and possible values for those fields. In general, a request will consist of fields from more than one group, but some groups are incompatible. Further, within each group, some request fields are incompatible. Some otherwise valid requests might not be valid for use in some situations (e.g., sessions), even though this is not indicated by the BNF syntax. Finally, even with a valid request, a server might not implement all possible request fields or combinations there-of, but it is required to parse and interpret all normative request fields and respond appropriately, even if this response is an error. Details of what servers are expected to implement are defined in Annex J.
+
+NOTE – Which responses or methods for signalling error conditions are appropriate depends on the transport layer used. D.1 provides examples for servers using HTTP as transport protocol.
+
+### C.1.2 Request structure
+
+The JPIP request consists of the following fields:
+
+- Target identification fields;
+- Session and channel management fields;
+- View-window request fields;
+- Metadata field;
+- Data limiting request fields;
+- Server control request fields;
+- Cache management request fields;
+- Upload request fields;
+- Client capability and preference fields.
+
+The elements in the request shall be sent in compliance with the selected transport protocol. For example, in HTTP, the requests are expressed as the characters listed in the BNF syntax, multiple parameters are joined with an "&" character, and the requests can be part of the query field of a GET request, or the body of a POST request. See Annexes F, G and H for details.
+
+The fields in the request shall be sent in compliance with the selected transport protocol. For example, in HTTP, the requests can be part of the query field of a GET request, or the body of a POST request, with individual request fields separated by a "&" character – see Annexes F, G and H for details. In contexts such as these, certain characters found within the BNF syntax or the request parameters might need to be escaped in order to avoid ambiguity. For example, a request field of the form "target=me&my dog" should be escaped in an HTTP context, becoming "target=me%26my%20dog", so as to avoid confusion with the "&" used to separate request fields. As another example, "metareq=[roid/w]" should be escaped in an HTTP context, becoming "metareq=%5broid/w%5d" so as to avoid the use of non-URI character – see IETF RFC 3986 for more on reserved characters, disambiguation and escaping via the hex-hex encoding. Parsers of requests found in such contexts should be prepared to perform hex-hex decoding of each request field.
+
+```
+
+jpip-request-field = target-field
+                    / channel-field
+                    / view-window-field
+                    / metadata-field
+                    / data-limit-field
+                    / server-control-field
+                    / cache-management-field
+                    / upload-field
+                    / client-cap-pref-field
+
+target-field       = target                ; C.2.2
+                   / subtarget            ; C.2.3
+                   / tid                   ; C.2.4
+
+```
+
+|                        |           |          |
+|------------------------|-----------|----------|
+| channel-field          | = cid     | ; C.3.2  |
+|                        | / cnew    | ; C.3.3  |
+|                        | / cclose  | ; C.3.4  |
+|                        | / qid     | ; C.3.5  |
+| view-window-field      | = fsiz    | ; C.4.2  |
+|                        | / roff    | ; C.4.3  |
+|                        | / rsiz    | ; C.4.4  |
+|                        | / fvsiz   | ; C.4.5  |
+|                        | / rvoff   | ; C.4.6  |
+|                        | / rvsiz   | ; C.4.7  |
+|                        | / comps   | ; C.4.8  |
+|                        | / stream  | ; C.4.9  |
+|                        | / context | ; C.4.10 |
+|                        | / srate   | ; C.4.11 |
+|                        | / roi     | ; C.4.12 |
+|                        | / layers  | ; C.4.13 |
+|                        | / mctres  | ; C.4.14 |
+| metadata-field         | = metareq | ; C.5.2  |
+| data-limit-field       | = len     | ; C.6.1  |
+|                        | / quality | ; C.6.2  |
+| server-control-field   | = align   | ; C.7.1  |
+|                        | / wait    | ; C.7.2  |
+|                        | / type    | ; C.7.3  |
+|                        | / drate   | ; C.7.4  |
+|                        | / sendto  | ; C.7.5  |
+|                        | / abandon | ; C.7.6  |
+|                        | / barrier | ; C.7.7  |
+|                        | / twait   | ; C.7.8  |
+| cache-management-field | = model   | ; C.8.1  |
+|                        | / tpmodel | ; C.8.3  |
+|                        | / need    | ; C.8.4  |
+|                        | / tpneed  | ; C.8.5  |
+|                        | / mset    | ; C.8.6  |
+| upload-field           | = upload  | ; C.9.1  |
+| client-cap-pref-field  | = cap     | ; C.10.1 |
+|                        | / pref    | ; C.10.2 |
+|                        | / csf     | ; C.10.3 |
+|                        | / handled | ; C.10.4 |
+
+### C.1.3 Restrictions on combining request fields
+
+Each type of JPIP request field shall occur no more than once in a single request.
+
+In general, requests for image data (view-window requests) can be combined with requests for additional metadata. However, there are restrictions on how the request fields may be combined.
+
+The upload request field shall not be combined with `metadata-field`, `data-limit-field`, or `server-control-field`.
+
+## C.2 Target identification fields
+
+### C.2.1 Introduction to logical targets
+
+Each JPIP request is directed to a specific representation of a specific original named resource or a specific portion of that resource. That resource might be a physically stored file or object, or might be something that is created virtually by the server upon request.
+
+The specific representation, whether that is the original encoded form or a transcoded form, or whether that is a specific byte range or is the entire resource, is referred to as the logical target. The logical target is specified through three request fields: Target ID, Target and Sub-target.
+
+The Target request field specifies the original named resource to which the request is directed. It is specified using a `PATH`, which could be a simple string or a URI. If the Target field is not specified and the request is carried over HTTP (or HTTPS), then the JPIP server shall direct the request to the resource specified through the path component of the JPIP
+
+request URL. This original named resource might be an actual file or other object physically stored on the server, or it might be something that the server creates in response to a JPIP request.
+
+The Sub-target request field specifies the specific byte range of the original named resource (specified through the Target request field) to which the request is directed. If the Sub-target request field is not specified, the server shall direct the request to the entire byte range of the original resource.
+
+The Target ID request field can be used to further specify a particular encoding of the resource in situations where the client and server have previously exchanged data from this resource. For example, the server might have previously supplied a transcoded version of the file to the client based on information supplied and the conditions around a previous request. If that client has preserved the data previously transmitted in its cache, it will desire to continue to receive data using that same transcoding so that it can continue to use the data in the cache. The Target ID is a server defined identification string, which the server has previously associated with that specific representation of that specific original named resource, or a byte range of some specific original named resource.
+
+If a client specifies both the original named resource (through either the Target request field or through the path component of the JPIP Request URL) and Target-ID, the server shall verify whether or not it can respond to the request in the same manner as when it originally assigned that Target ID to that resource. If the server cannot respond in the same manner, it shall use a JPIP-tid response header to inform the client of a new Target ID, at which point the client will know that it needs to discard any previously cached data.
+
+If a logical target is to be served with JPP-stream or JPT-stream messages, the server shall ensure that the associated data-bins remain consistent throughout all responses that are issued within the same session. Where the server, or a related server, also issues a Target ID, the server or related server shall ensure that the data-bins remain consistent across all responses issued with the same Target ID, whether they are issued within the same session or not.
+
+If the channel ID request field is included in the request, the request need not include Target, Sub-Target or Target ID fields.
+
+The following examples illustrate the specification of logical targets:
+
+EXAMPLE 1: For JPIP request URL of
+
+"http://one.jpeg.org/imageserver.cgi?target= http%3A%2F%2Fone.jpeg.org%2Fimages%2Fpicture.jp2&fsiz=200,200" the logical target is the entire byte range contained within the URI "http://one.jpeg.org/images/picture.jp2," relative to the server root document directory.
+
+EXAMPLE 2: For JPIP request URL of
+
+"http://one.jpeg.org/imageserver.cgi? target= http%3A%2F%2Fone.jpeg.org%2Fimages%2Fpicture.jp2&tid=4384-5849-af4d-3dca&fsiz=200,200" the logical target is the entire byte range contained within the URI "http://one.jpeg.org/images/picture.jp2," relative to the server root document directory, with a representation specified by the server defined Target ID 4384-5849-af4d-3dca.
+
+EXAMPLE 3: For JPIP request URL of
+
+"http://one.jpeg.org/imageserver.cgi?target= http%3A%2F%2Fone.jpeg.org%2Fimages%2Fpicture.jp2&subtarget=1038-13458&fsiz=200,200" the logical target is the range of bytes, starting with byte 1038, and all bytes up to and including bytes 13458, contained within the URI "http://one.jpeg.org/images/picture.jp2," relative to the server root document directory.
+
+EXAMPLE 4: For JPIP request URL of "http://one.jpeg.org/imageserver.cgi?cid=1234-5849-af4d-3dca&fsiz=200,200" the logical target is the resource to which the server has associated with the channel with ID 1234-5849-af4d-3dca.
+
+EXAMPLE 5: For JPIP request URL of "http://one.jpeg.org/images/picture.jp2?fsiz=200,200" the logical target is the entire byte range contained within the file "images/picture.jp2," relative to the server root document directory.
+
+EXAMPLE 6: For JPIP request URL of "http://one.jpeg.org/images/picture.jp2?subtarget=1038-13458&fsiz=200,200" the logical target is the range of bytes, starting with byte 1038, and all bytes up to and including byte 13458, contained within the file "images/picture.jp2," relative to the server root document directory.
+
+### C.2.2 Target (target)
+
+target = "target" "=" PATH
+
+This field is used to specify the original named resource (often the name of a file on the server). If the Target request field is missing, then the server shall determine the original named resource by other means.
+
+### C.2.3 Sub-target (subtarget)
+
+subtarget = "subtarget" "=" byte-range / src-codestream-specs
+
+```
+byte-range = UINT-RANGE
+src-codestream-specs = UINT-RANGE
+```
+
+This field can be used to qualify the original named resource through the specification of a byte range or a range of codestreams in the original resource. The logical target is to be interpreted as the indicated byte range or a range of codestreams of the original named resource. For the purpose of requests and responses involving this logical target, the server shall assign consecutive indices starting from zero to the codestreams in this target.
+
+NOTE – Defining a logical target as a range of codestreams thus relabels the codestreams, and effectively replaces the codestream indices, if any, in the original resource by consecutive indices starting from zero.
+
+The lower and upper bounds of the supplied range are inclusive, where bytes or codestreams are counted from zero.
+
+### C.2.4 Target ID (tid)
+
+```
+tid = "tid" "=" target-id
+target-id = IDTOKEN
+```
+
+This field can be used to supply a `target-id` string, which was previously generated by the server to absolutely identify the logical target that is being accessed, including any discretionary transcoding performed by the server. The logical target name is not necessarily unique and does not necessarily correspond to a single encoding of its contents, whereas the `target-id` string, together with the original resource name and byte range, should absolutely identify both the imagery and its encoding.
+
+If `target-id` is "0", the logical target is specified through the use of the Target, Sub-target and JPIP URL path component, and the client is explicitly requesting that the server inform it of the assigned `target-id`, if there is one. The server shall include a Target ID header in its response to all client requests with a `target-id` of "0".
+
+`target-id` shall not exceed 255 characters in length.
+
+## C.3 Fields for working with sessions and channels
+
+### C.3.1 Introduction
+
+A request shall be stateless unless one or both of the following conditions occur:
+
+- The request includes a valid Channel ID field;
+- The request includes a New Channel field (see below), and the server response includes a New Channel response header with a newly issued `channel-id`.
+
+See B.2 for discussions on sessions and channels.
+
+### C.3.2 Channel ID (cid)
+
+```
+cid = "cid" "=" channel-id
+channel-id = IDTOKEN
+```
+
+- This field is used to associate the request with a particular JPIP channel, and hence the session to which the channel belongs.
+
+### C.3.3 New Channel (cnew)
+
+```
+cnew = "cnew" "=" 1#transport-name
+transport-name = TOKEN
+```
+
+This field is used to request a new JPIP channel. If no Channel ID request field is present, the request is for a new session. Otherwise, the request is for a new channel in the same session as the channel identified by the Channel ID request field.
+
+The value string identifies the names of one or more transport protocols that the client is willing to accept. This Recommendation | International Standard defines only the transport names, "http", "https", "http-tcp" and "http-udp". Details of the use of JPIP over the "http" transport appear in Annex F. Annex G describes the use of JPIP over the "http-tcp" transport and Annex K describes the use of JPIP over the "http-udp" transport.
+
+If the server is willing to open a new channel, using one of the indicated transport protocols, it shall return the new channel identifier token using the New Channel response header (see D.2.3). In this case, the present request is the first request within the new channel.
+
+It is possible for a client to open a channel to a new logical target within the same session. To do this, the client's request shall identify both an existing Channel ID, and a logical target. When opening a new channel to the same logical target which is associated with an existing channel, there is no need to specify the logical target explicitly.
+
+If the server is not willing to open a new channel, it shall not return a New Channel response header, but the request shall be serviced as though the New Channel request field had not been included. This means that a request that specifies an existing Channel ID shall be treated as a request within that channel, while a request that includes no Channel ID request field shall be treated as a stateless request. In the event that the New Channel request identifies a different logical target to that which is associated with the supplied existing Channel ID, the server will not be able to respond to the request without either issuing a new Channel ID or returning an error code.
+
+EXAMPLE 1: "target=nice.jp2&cnew=http" requests the first channel of a new session to the image "nice.jp2" using the "http" transport. If no channel is assigned by the server, the request will be treated as stateless.
+
+EXAMPLE 2: "cid=013ac8&cnew=http-tcp" requests a new channel within the same session which is associated with Channel ID 013ac8. The new channel is to use the "http-tcp" transport and refers to the same logical target as Channel ID 013ac8. A single cache model is shared by these channels. If no channel is assigned by the server, the server shall treat the request as though the New Channel request field had been omitted.
+
+EXAMPLE 3: "target=nice.jp2&cid=013ac8&cnew=http" requests a new channel within the same session which is associated with Channel ID "013ac8." The new channel is to use the "http" transport. The logical target associated with the new channel is distinct from that associated with Channel ID "013ac8" and a separate cache model is used for the new channel. The cache models for both targets are associated with this common session.
+
+### C.3.4 Channel Close (cclose)
+
+```
+cclose = "cclose" "=" ("*" / 1#channel-id)
+```
+
+This field is used to close one or more open channels to a session. If the value field contains one or more channel-id tokens, they shall all belong to the same session. In this case, the Channel ID request field is not necessary, but if provided it shall also reference a channel belonging to the same session.
+
+If the value field is "\*", the session shall be identified by the inclusion of a Channel ID request field, and the server shall close all channels associated with the session.
+
+The server shall complete its response on any channel specified in the Channel Close request before actually closing the channel.
+
+The combination of "wait = yes" with "cclose=\*" is not recommended. If this situation is encountered, the server can decide which of the two takes priority.
+
+### C.3.5 Request ID (qid)
+
+```
+qid = "qid" "=" UINT
+```
+
+This field is used to specify a Request ID value. Each channel has its own request queue, with its own Request ID counter. The server may process requests which do not contain a Request ID, or whose Request ID is zero, on a first-come-first-served basis. However, it shall not process a request which arrives with a Request ID value of  $n$  until it has processed all requests with request ID values of  $n_0$  to  $n-1$ , inclusive. Here  $n_0$  is the `qid` supplied in the request which originally created the channel, or is equal to 1 if no `qid` was present when creating the channel.
+
+NOTE – The response to a request containing `cnew` which results in the creation of a new channel is processed as if the request were issued in the new channel. This means the next request with a non-zero `qid` value to be processed in the new channel has the `qid` value  $n_0+1$ .
+
+## C.4 View-window request fields
+
+### C.4.1 Mapping view-window requests to codestream image resolutions and regions
+
+The purpose of JPIP is to provide portions of a JPEG 2000 image and associated metadata in response to requests from a client. This is done via a sequence of requests and responses. For the image portion, the data requested can be less than the full image in terms of image frame size, region, quality, and/or components.
+
+In the simplest case, the image portion in question is defined directly with respect to the high resolution reference grid of the JPEG 2000 codestream(s) identified in the request, not the sampled grid of any particular image component. More generally, however, clients can request higher level image objects (e.g., JPX compositing layers or MJ2 video tracks) via the Codestream Context request field (see C.4.10). In this case, the requested image portion might need to be subjected to a coordinate transformation, in order to determine the portion of each associated codestream which is being requested. These coordinate transformations are described in C.4.10, and they shall be understood in terms of the following description of codestream image regions.
+
+![Figure C.1: Desired region within an image. A diagram showing a large rectangle representing an image with width f_x and height f_y. Inside it is a smaller shaded rectangle representing a desired region with width s_x and height s_y. The offset of the region from the top-left corner of the image is denoted by o_x (horizontal) and o_y (vertical).](67114ecf6da13c97a89aeff0d86885d5_img.jpg)
+
+Figure C.1: Desired region within an image. A diagram showing a large rectangle representing an image with width f\_x and height f\_y. Inside it is a smaller shaded rectangle representing a desired region with width s\_x and height s\_y. The offset of the region from the top-left corner of the image is denoted by o\_x (horizontal) and o\_y (vertical).
+
+Figure C.1 –Desired region within an image
+
+Codestream image regions are described using 3  $n$ -dimensional parameters where  $n$  is the number of dimensions required to describe this image. The size parameters and offset parameters specify the extent and location of the desired codestream image region with respect to a whole image that has the given frame size. Figure C.1 demonstrates this set-up for regular images with  $n = 2$ , but the construction carries over naturally to a higher number of dimensions. For most of this subclause, only this case is considered, denoting the frame size by parameters  $f_x$  and  $f_y$ , the offset of the region by parameters  $o_x$  and  $o_y$  and denoting the size of the region by parameters  $s_x$  and  $s_y$  as indicated in Figure C.1.
+
+EXAMPLE: A client wishing to fill a  $640 \times 480$  display with the whole image could make a request as follows " $f_{siz}=640,480 \&rsiz=640,480 \&roff=0,0$ ". Note that this can be done regardless of the original size of the image (and indeed without knowing the original size of the image).
+
+When none of the available image resolutions in the JPEG 2000 codestream correspond exactly to the requested frame size, the returned image data might be larger or smaller than the requested frame size, and might even differ in aspect ratio. The server shall determine a suitable codestream image resolution, denoted by size parameters  $f_x'$  and  $f_y'$ , and a suitable region on the codestream, denoted by parameters  $s_x'$ ,  $s_y'$ ,  $o_x'$  and  $o_y'$ , as shown in Figure C.2. Although the client can specify the direction for rounding, as part of the Frame Size request field, the client shall be prepared to deal with returned data that does not match the requested parameters exactly.
+
+![Figure C.2: Desired region with respect to the subsampled reference grid. A diagram showing a large rectangle representing a subsampled reference grid with width Xsiz' and height Ysiz'. Inside it is a smaller rectangle representing the desired region with width f_x' and height f_y'. The offset of the region from the top-left corner of the grid is denoted by o_x' (horizontal) and o_y' (vertical). The offset of the grid from the top-left corner of the image is denoted by XOsiz' (horizontal) and YOsiz' (vertical).](107da2e3495b2f24352c9e3b26ec4841_img.jpg)
+
+Figure C.2: Desired region with respect to the subsampled reference grid. A diagram showing a large rectangle representing a subsampled reference grid with width Xsiz' and height Ysiz'. Inside it is a smaller rectangle representing the desired region with width f\_x' and height f\_y'. The offset of the region from the top-left corner of the grid is denoted by o\_x' (horizontal) and o\_y' (vertical). The offset of the grid from the top-left corner of the image is denoted by XOsiz' (horizontal) and YOsiz' (vertical).
+
+Figure C.2 – Desired region with respect to the subsampled reference grid
+
+As shown in Figure C.2, the size of the suitable codestream image resolution is given by  $f_x' = Xsiz' - XOsiz'$  and  $f_y' = Ysiz' - YOsiz'$ , where  $XOsiz'$ ,  $YOsiz'$ ,  $Xsiz'$ , and  $Ysiz'$  are derived using Equation C-1.
+
+$$XOsiz' = \left\lceil \frac{XOsiz}{2^r} \right\rceil; \quad YOsiz' = \left\lceil \frac{YOsiz}{2^r} \right\rceil; \quad Xsiz' = \left\lfloor \frac{Xsiz}{2^r} \right\rfloor; \quad Ysiz' = \left\lfloor \frac{Ysiz}{2^r} \right\rfloor \quad (C-1)$$
+
+where:
+
+$r$  is determined by the server in order to match the requested image size ( $f_x$  and  $f_y$ ) as closely as possible, subject to any rounding preferences supplied via the Frame Size request field.
+
+Here,  $XO_{siz}$ ,  $YO_{siz}$ ,  $Xs_{iz}$  and  $Ys_{iz}$  are taken from the relevant codestream's  $SIZ$  marker segment. It is natural to interpret  $r$  as a number of discarded highest DWT levels, and indeed  $r$  shall be an integer no less than 0. However, the value of  $r$  is not limited by the number of DWT levels which were used to compress any tile-component in the codestream.
+
+Once the suitable frame size,  $f_{x'}$  and  $f_{y'}$ , have been found, the region size,  $s_{x'}$  and  $s_{y'}$ , and offset,  $o_{x'}$  and  $o_{y'}$ , associated with the codestream image region are determined by Equation C-2.
+
+$$o_{x'} = \left\lfloor o_x \cdot \frac{f_{x'}}{f_x} \right\rfloor; \quad o_{y'} = \left\lfloor o_y \cdot \frac{f_{y'}}{f_y} \right\rfloor; \quad s_{x'} = \left\lceil (s_x + o_x) \cdot \frac{f_{x'}}{f_x} \right\rceil - o_{x'}; \quad s_{y'} = \left\lceil (s_y + o_y) \cdot \frac{f_{y'}}{f_y} \right\rceil - o_{y'} \quad (C-2)$$
+
+EXAMPLE 2: Suppose the requested Frame Size is  $128 \times 128$ , and the image on the codestream's high resolution reference grid is described by  $XO_{siz}=127$ ,  $Xs_{iz}=648$ ,  $YO_{siz}=0$  and  $Ys_{iz}=504$ . Suppose also that 3 levels of wavelet transform exist for all image components in the codestream. The available codestream image sizes are then:
+
+$$\begin{aligned} 521 \times 504 & \quad \left( \left\lceil \frac{648}{1} \right\rceil - \left\lceil \frac{127}{1} \right\rceil \text{ by } \left\lceil \frac{504}{1} \right\rceil - 0 \right) \\ 260 \times 252 & \quad \left( \left\lceil \frac{648}{2} \right\rceil - \left\lceil \frac{127}{2} \right\rceil \text{ by } \left\lceil \frac{504}{2} \right\rceil - 0 \right) \\ 130 \times 126 & \quad \left( \left\lceil \frac{648}{4} \right\rceil - \left\lceil \frac{127}{4} \right\rceil \text{ by } \left\lceil \frac{504}{4} \right\rceil - 0 \right) \\ 65 \times 63 & \quad \left( \left\lceil \frac{648}{8} \right\rceil - \left\lceil \frac{127}{8} \right\rceil \text{ by } \left\lceil \frac{504}{8} \right\rceil - 0 \right) \end{aligned}$$
+
+Thus if the request is for a larger frame size (round-direction is round-up) the returned frame size will be  $260 \times 252$ . If the request is for a smaller frame size (round-direction is round-down), then a  $65 \times 63$  frame size will be used. Note that, as in this example, the available codestream image frame sizes are not generally exact powers of 2.
+
+Subsampling of an image component, as specified by  $XR_{siz}$  and  $YR_{siz}$ , has no effect on the interpretation of the requested image region or image resolution within any requested codestream.
+
+EXAMPLE 3: A request for a  $256 \times 256$  region from the upper left corner of a  $512 \times 512$  image can be made with:
+
+`fsiz=512,512&rsiz=256,256`
+
+Suppose the codestream contains an image subsampled in components 1 and 2 but not in component 0. Specifically, suppose  $Xs_{iz}=1024$ ,  $Ys_{iz}=1024$ ,  $XO_{siz}=0$ ,  $YO_{siz}=0$ , and  $XR_{siz}^0=1$ ,  $YR_{siz}^0=1$ ,  $XR_{siz}^1=2$ ,  $YR_{siz}^1=2$ ,  $XR_{siz}^2=2$ , and  $YR_{siz}^2=2$ . The server would leave out the highest resolution level of all three components, and return tiles or precincts sufficient to provide  $256 \times 256$  samples of component 0, but only  $128 \times 128$  samples of components 1 and 2. The client thus has data to display the upper left corner at half the size of the full image and still subsampled. If the client desires to display non-subsampled chroma components, it could issue an additional request such as:
+
+`fsiz=1024,1024&rsiz=512,512&comps=1,2`
+
+The server would then return sufficient data to provide  $256 \times 256$  samples of components 1 and 2, which could be combined with the component 0 data already received to obtain a non-subsampled but half-sized image.
+
+If all three components had been subsampled, the server would provide only  $128 \times 128$  samples of all three components for the original request (`fsiz=512,512&rsiz=256,256`) since image resolution and image regions are assessed with respect to the reference grid of each requested codestream.
+
+The above considerations for two dimensional images carry over naturally to images of higher dimensionality, e.g., to the case  $n = 3$  where a third coordinate is added to each group of parameters. Specifically, the frame size is then represented by three numbers  $f_x$ ,  $f_y$  and  $f_z$ , the offset by  $o_x$ ,  $o_y$  and  $o_z$  and the region size by  $s_x$ ,  $s_y$  and  $s_z$ . In that case, Equation C-1 extends to:
+
+$$ZO_{siz}' = \left\lceil \frac{ZO_{siz}}{2^r} \right\rceil \quad Zs_{iz}' = \left\lceil \frac{Zs_{iz}}{2^r} \right\rceil$$
+
+where ZOsiz and Zsiz specify the original image offset and canvas size in the Z direction, respectively. Equation C-2 extends to:
+
+$$oz' = \left\lfloor oz \cdot \left( \frac{fz'}{fz} \right) \right\rfloor \quad sz' = \left\lceil (sz + oz) \cdot \frac{fz'}{fz} \right\rceil - oz'$$
+
+For images represented by Rec. ITU-T T.809 | ISO/IEC 15444-10 codestreams, ZOsiz and Zsiz are taken from the relevant NSI marker segment.
+
+For images represented by Rec. ITU-T T.801 | ISO/IEC 15444-2 codestreams that involve wavelet-based multiple component transformation, the generated output components of the codestream can be interpreted as the third (Z) dimension of the volumetric image. In this situation, clients can either choose to use the two-dimensional or three-dimensional request syntax to fetch data from the server and, in the case of three-dimensional requests, servers can make their own determination of suitable values for ZOsiz and Zsiz as well as the association between volumetric slices and generated output components of the codestream. For two-dimensional requests, it is up to the client to determine the components that are associated with slices of interest and make the necessary requests; for three-dimensional requests, it is the duty of the server to find the relevant components for the requested image volume. In the latter case, servers are not required to honour the comp and mctres fields, see clauses C.4.8 and C.4.14, and their usage by clients is discouraged in this case.
+
+Notwithstanding the fact that servers can make their own determination of suitable values for ZOsiz and Zsiz and the association between slices and generated output components, when responding to a client request involving three-dimensional request syntax for a volumetric image that uses a wavelet-based multiple-component transformation, they are recommended to make this choice using the following steps.
+
+1. ZOsiz should be taken identical to the minimum of all Omcc<sup>i</sup> values in all MCC markers within the codestream identified by the request, see Rec. ITU-T T.801 | ISO/IEC 15444-2. This choice ensures a reasonable definition of the resolution levels in the Z direction compatible to the origin of the wavelet transformation, and eases the extraction of lower-resolution images from the stream.
+2. Zsiz should be taken identical to the number of slices identified in Step 3 below.
+3. In the case where a Rec. ITU-T T.801 | ISO/IEC 15444-2 conforming file format is available for the target of the request:
+  - a. All compositing layers of the file that use the codestream that is the target of the request should be identified and each compositing layer in this set should be identified with one slice of the volumetric image. The Z coordinate to be assigned to the first compositing layer in this set is to be ZOsiz, as determined above, after which all following slices are assigned consecutive ascending Z coordinates in the order they appear in the file.
+  - b. For each compositing layer, the channels that are relevant to the request should be determined using any channel definition box found within the compositing layer. If the layer contains a channel definition box, the relevant channels are those that are associated with a colour via the Asoc field of the channel definition box; otherwise, all channels of the compositing layer are relevant.
+  - c. For each relevant channel of a compositing layer (slice), the slice should be associated with all generated output components used to provide the data for that channel. For palette mapped images, the component mapping box is also involved in determining this set of associated components.
+
+If no Rec. ITU-T T.801 | ISO/IEC 15444-2 conforming file format is available, servers should use whatever other descriptive data might be available to them, outside the scope of this Recommendation | International Standard, to identify volumetric slices and the set of generated output components associated with each slice, assigning  $Z = ZOsiz$  to the first such slice and assigning consecutive ascending Z coordinates to each subsequent slice in the order determined by this descriptive data. The descriptive data, in this case, might be defined in other members of the Rec. ITU-T T.8xx | ISO/IEC 15444-x family of Recommendations | Standards, or otherwise.
+
+If no Rec. ITU-T T.801 | ISO/IEC 15444-2 conforming file format is available, nor any other descriptive data as detailed above, the following procedure can be used as a last resort to come to a reasonable definition of slices:
+
+- a. A codestream is identified as a grey scale volume image if each generated component is reconstructed by exactly one transformation stage, as defined by Rec. ITU-T T.801 | ISO/IEC 15444-2, and if the type of the transformation stage is a wavelet transformation. A codestream is identified as a colour volume image, if each generated component is reconstructed by exactly two transformation stages of which the first one, which is applied to the spatial components of the codestream, is a wavelet transformation, and of which the second one is not a wavelet transformation, but a decorrelation or dependency transformation. All other set-ups cannot be handled by this procedure.
+
+- b. For each generated output component  $g$ , the MCC marker  $MCC^i$ , that describes the wavelet transformation step taken to compute  $g$  from the spatial components of the canvas system, is identified; there should be exactly one such marker.
+- c. If the image is a grey-scale image, the index  $j$  is found in the output component collection of that marker such that  $Wmcc^j$  equals  $g$ ; equivalently,  $j$  is the output slot in the transformation that generates component  $g$ . Then generated component  $g$  contributes to the slice with  $Z = j + Omcc^i$ . This provides a  $Z$  coordinate for the component  $g$  based on the ordering of the output of the wavelet transformation step.
+- d. If the image is a colour image, all intermediate input components of the dependency or decorrelation transformation required to reconstruct the generated output component  $g$  are found first. For each such intermediate input component, the  $Z$  coordinate for that component is found in the manner described above for grey-scale images. If this  $Z$  coordinate differs amongst the intermediate input components involved in the reconstruction of generated output component  $g$ , then this procedure fails.
+- e. If this procedure succeeds in assigning a  $Z$  coordinate to each generated output component of the codestream then the  $Z$  coordinates are contiguous, ascending from the  $ZOsiz$  value found in Step 1, and  $Zsiz$  is the number of distinct  $Z$  coordinates assigned.
+
+### C.4.2 Frame Size (fsiz)
+
+```
+fsiz = "fsiz" "=" fx "," fy ["," round-direction]
+fx = UINT
+fy = UINT
+round-direction = "round-up" / "round-down" / "closest"
+```
+
+This field is used to identify the resolution associated with the requested view-window. The values  $fx$  and  $fy$  specify the dimensions of the desired image resolution. The `round-direction` value specifies how an available codestream image resolution shall be selected for each requested codestream, if the requested image resolution is not available within that codestream. The requested frame size is mapped to a codestream image resolution, following the procedure described in C.4.1, possibly with the addition of coordinate transformations requested via a Codestream Context request field (see C.4.10). A client wishing to control the exact number of samples received for a particular image component might need to increase the requested frame size, as explained in C.4.1. The `round-direction` options defined by this Recommendation | International Standard are described in Table C.1.
+
+Table C.1 – Round direction options
+
+| Round-direction | Meaning                                                                                                                                                                                                                                                                                                                                                 |
+|-----------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| "round-up"      | For each requested codestream, the smallest codestream image resolution whose width and height are both greater than or equal to the specified size shall be selected. If there is none, then the largest available codestream image resolution shall be used.                                                                                          |
+| "round-down"    | For each requested codestream, the largest codestream image resolution whose width and height are both less than or equal to the specified size shall be selected. If there is none, then the smallest available codestream image resolution shall be used. This is the default value when the <code>round-direction</code> parameter is not specified. |
+| "closest"       | For each requested codestream, the codestream image resolution that is <code>closest</code> to the specified size in area (where $area = fx \times fy$ ) shall be selected. Where two codestream image resolutions have areas which are equidistant from $fx \times fy$ , the larger of the two shall be selected.                                      |
+
+If the Frame Size request field is omitted from a view-window request and `metadata-only` is not specified in a metadata request field (see C.5.1), the requested view-window includes no compressed image data and no tile-specific headers, but it does include all other header (codestream and file format) information that would have been returned had the client included the Frame Size request field. See C.5.1 for further information on the file format information (metadata) which is implicitly requested along with the view-window request.
+
+### C.4.3 Offset (roff)
+
+```
+roff = "roff" "=" ox "," oy
+ox = UINT
+oy = UINT
+```
+
+This field is used to identify the upper left hand corner (offset) of the spatial region associated with the requested view-window; if not present, the offsets default to 0. The actual displacement of a codestream image region from the upper left hand corner of the image, at the actual codestream image resolution selected by the server, is obtained following the procedure described in C.4.1, possibly with the addition of coordinate transformations requested via a Codestream Context request field (see C.4.10).
+
+Use of the Offset field is valid only in conjunction with the Frame Size request field.
+
+If a codestream image region specified using Region Size and/or Offset turns out to be empty (no area), the server's response should not include any compressed image data for that codestream. In particular, responses of type JPP-stream or JPT-stream should contain no messages which reference precinct, tile or tile-header data-bins of that codestream. The server can, at its discretion, opt to return main header or metadata-bin messages that would have been returned in response to a request that omitted the Frame Size request field.
+
+### C.4.4 Region Size (rsiz)
+
+```
+rsiz = "rsiz" "=" sx "," sy
+sx = UINT
+sy = UINT
+```
+
+This field is used to identify the horizontal and vertical extent (size) of the spatial region associated with the requested view-window; if not present, the region extends to the lower right-hand corner of the image. The actual dimensions of a codestream image region, at the actual codestream image resolution selected by the server, are computed following the procedure described in C.4.1, possibly with the addition of coordinate transformations requested via a Codestream Context request field (see C.4.10). A requested codestream image region need not necessarily be fully contained within the codestream, in which case the server simply takes the intersection between the available codestream image region and the requested region.
+
+Use of the Region Size request field is valid only in conjunction with the Frame Size request field.
+
+The codestream image region may be empty, for example if *sx* or *sy* were zero. If empty, then the server's response should not include any compressed image data for that codestream. In particular, responses of type JPP-stream or JPT-stream should contain no messages which reference precinct, tile or tile-header data-bins of that codestream. The server can, at its discretion, opt to return main header or metadata-bin messages that would have been returned in response to a request that omitted the Frame Size request field.
+
+### C.4.5 Frame size for variable dimension data (fvsiz)
+
+```
+fvsiz = "fvsiz" "=" 1#UINT [", " round-direction]
+round-direction = "round-up" / "round-down" / "closest"
+```
+
+This request takes a variable number of arguments. There shall be as many numerical arguments as there are dimensions in the source codestream. Specifically, if the image is a regular two-dimensional image, this request field is equivalent to the *fsiz* field with the first argument defining *fx* and the second defining *fy*. If the source stream represents volumetric data, there shall be three numerical arguments, specifying the view-window extents *fx*, *fy* and *fz*, in that order.
+
+This field is used to identify the resolution associated with the requested view-window. The numerical arguments specify the desired image resolution, one per dimension. The *round-direction* value specifies how an available codestream image resolution shall be selected for each requested codestream, if the requested image resolution is not available within that codestream. The requested frame size is mapped to a codestream image resolution, following the procedure described in C.4.1, possibly with the addition of coordinate transformations requested via the Codestream Context request field (see C.4.10).
+
+### C.4.6 Offset for variable dimension data (rvoff)
+
+```
+rvoff = "rvoff" "=" #1UINT
+```
+
+This field is used to identify the upper left (front) corner (offset) of the spatial region associated with the requested view-window; if not present, the offset defaults to 0. The actual displacement of a codestream image region from the upper left (front) corner of the image, at the actual codestream image resolution selected by the server, is obtained following the procedure described in C.4.1, possibly with the addition of coordinate transformation requested via a Codestream Context request field (see C.4.10). This field takes a variable number of arguments, there shall be as many arguments to the *rvoff* field as there are dimensions in the source stream. Specifically, for regular two-dimensional images exactly, two arguments are required and this field is equivalent to *roff*. For volumetric images, exactly three arguments are required, which define *ox*, *oy* and *oz*.
+
+Use of the Offset field for Variable Dimension Data is valid only in conjunction with the Frame Size request field for Variable Dimension Data. If the view-window specified using Region Size and/or Offset turns out to be empty (no area), the server's response should not include any compressed image data. In particular, responses of type "jpp-stream" or "jpt-stream" should contain no messages which reference precinct, tile or tile-header data-bins. The server can, at its discretion, opt to return main header or metadata-bin messages that would have been returned in response to a request that omitted the Frame Size request field.
+
+### C.4.7 Region size for variable dimension data (rvsiz)
+
+```
+rvsiz = "rvsiz" "=" #1UINT
+```
+
+This field is used to identify the extent (size) of the spatial region associated with the requested view-window; if not present, the region extends to the lower right (back) corner of the image. The actual extent of the view-window, at the actual resolution level selected by the server, are computed following the procedure described in C.4.1. The view-window need not necessarily be fully contained within the image itself, in which case the server simply takes the intersection between the full image region and the requested view-window.
+
+This field takes a variable number of arguments, and there shall be exactly as many arguments as there are dimensions in the target stream. If the view-window specified using Region Size and/or Offset turns out to be empty (no area), the server's response should not include any compressed image data. In particular, responses of type "jpp-stream" or "jpt-stream" should contain no messages which reference precinct, tile or tile-header data-bins. The server can, at its discretion, opt to return main header or metadata-bin messages that would have been returned in response to a request that omitted the Frame Size request for Variable Dimension Data field. In case the image is a regular two-dimensional image, this request takes two arguments, and is identical to the `rsiz` field. For volumetric images, the three arguments are `sx`, `sy` and `sz`, in this order.
+
+### C.4.8 Components (comps)
+
+```
+comps = "comps" "=" 1#UINT-RANGE
+```
+
+This field is used to identify the image components that are to be included in the requested view-window; if not present, the request is understood to include all available image components of all codestreams identified via the Codestream request field, and all relevant components of all codestreams requested via the Codestream Context request field (see C.4.10). These "relevant" components are those which are involved in the reproduction of the image entities (e.g., JPX compositing layers or MJ2 video tracks) which are specified via the Codestream request field.
+
+The values in this request field represent the indices of the image components of interest. Image component indices start from 0, and have the interpretation assigned to them by the JPEG 2000 codestream syntax, as described in ITU-T Rec. T.800 | ISO/IEC 15444-1, but note that these are the components which are obtained by decoding and inverse wavelet transforming the compressed data, prior to the application of the inverse RCT or ICT component transform. For codestreams conforming to Rec. ITU-T T.801 | ISO/IEC 15444-2, the components identified here are those identified as "spatial components", i.e., those obtained by decoding and inverse wavelet transforming the compressed data, prior to the application of any inverse multi-component transform, dependency component transform, or multi-component wavelet transform.
+
+Non-existent components in any of the requested codestreams shall be disregarded.
+
+Usage of the `comps` field in combination with the Frame, Region or Region Offset request field for Variable Dimension Data with three or more numerical arguments on Rec. ITU-T T.801 | ISO/IEC 15444-2 codestreams is discouraged and servers cannot be expected to handle it.
+
+### C.4.9 Codestream (stream)
+
+```
+stream = "stream" "=" 1#sampled-range
+sampled-range = UINT-RANGE [":" sampling-factor]
+sampling-factor = UINT
+```
+
+This field is used to identify which codestream or codestreams belong to the requested view-window. If the field is omitted and the codestream(s) cannot be determined by other means, the default behaviour is for servers to associate the request with the single codestream that has identifier 0.
+
+NOTE – The Codestream Context request field (see C.4.10) provides an additional means for requesting codestreams.
+
+For JPEG 2000 family targets, codestream indices are those which are embedded in the corresponding Placeholder box that appears within the appropriate metadata-bin, as described in A.3.6. For file formats which have implied codestream identifiers, those identifiers should agree with the indices used here.
+
+Where a range of codestreams is identified, the absence of an upper bound means that the range extends to all codestreams with larger identifiers. Where an upper bound is provided, the upper bound provides the absolute identifier of the last codestream in the range.
+
+Whether or not an upper bound is provided, a codestream range may be qualified by an additional `sampling-factor`. The `sampling-factor`, if provided, shall be a strictly positive integer,  $F$ . The range then includes all codestream identifiers  $L+Fk$  which lie within the unqualified range, where  $L$  is the identifier of the first codestream in the range. The client's index of the codestreams of interest is  $k$  and  $k$  is a UINT.
+
+### **C.4.10 Codestream Context (context)**
+
+```
+
+context = "context" "=" 1#context-range
+
+context-range = jpxl-context-range / mj2t-context / jpm-context / jpxf-context-range
+                / reserved-context
+
+jpm-context = "jpm" "<" jpm-pages ">" [ jpm-objects ]
+jpm-pages = [ jpm-page-collection ":" ] jpm-sampled-range
+jpm-objects = "[" jpm-object-range "]"
+jpm-page-collection = object-id
+jpm-sampled-range = page-object-range [ ":" sampling-factor ]
+page-object-range = 1#(object-id [ "-" [ object-id ] ])
+jpm-object-range = UINT-RANGE ":" jpm-object-type / UINT-RANGE
+                  / ":" jpm-object-type
+jpm-object-type = "mask" / "image" / "nostrm"
+object-id = UINT / TEXT-LABEL
+jpxl-context-range = "jpxl" "<" jpx-layers ">" [ "[" jpxl-geometry "]" ]
+jpx-layers = sampled-range
+jpxl-geometry = "s" jpx-iset "i" jpx-inum
+jpx-iset = UINT
+jpx-inum = UINT
+mj2t-context = "mj2t" "<" mj2-track ">" [ "[" mj2t-geometry "]" ]
+mj2-track = NONZERO [ "+" "now" ]
+mj2t-geometry = "track" / "movie"
+reserved-context = 1*( TOKEN / "<" / ">" / "[" / "]" / "-" / ":" / "+" )
+jpxf-context-range = "jpxf" "<" jpx-frame-indices ">" [ "[" jpx-thread "]" ]
+jpx-frame-indices = sampled-range
+jpx-thread = UINT
+
+```
+
+This field can be used to request codestreams indirectly via "higher level" image entities. This Recommendation | International Standard defines contexts corresponding to JPX compositing layers (a JPX compositing layer might involve one or more codestreams), MJ2 or J2KS video tracks and JPM pages; however, the mechanism is designed for extensibility.
+
+If a Codestream Context request field is supplied, the requested view-window includes each of the codestreams which are associated with the requested context(s), in addition to any codestreams requested via the Codestream request field.
+
+The body of a Codestream Context request field consists of one or more `context-range` values. Each `context-range` is associated with a set of codestreams which can be determined by the server. A `context-range` can also identify coordinate remapping transformations which shall be applied to the Frame Size, Region Size and Offset parameters in order to determine the codestream image resolution and codestream image region for each of the codestreams associated with that `context-range`. Where the server is prepared to process a `context-range`, it shall identify the codestreams which are associated with that `context-range` by means of a Codestream Context response header.
+
+This Recommendation | International Standard defines four specific types of `context-range`, which are intended to address the needs of JPX, MJ2, J2KS and JPM file formats. The first of these `context-range` types, `jspxl-context-range`, is used to identify one or more JPX compositing layers. The indices of the compositing layers associated with a `jspxl-context-range` are supplied in the form of a `sampled-range`, following the same semantics as sampled codestream ranges in the Codestream request field. Where a `jspxl-context-range` is processed by the server, the codestreams belonging to the corresponding compositing layer(s) shall be identified within a Codestream Context response header.
+
+A `jspxl-context-range` can identify an optional coordinate remapping transformation, to be used in deducing the codestream image resolution and the codestream image region for each of its codestreams. This coordinate remapping transformation is determined by two non-negative integers, `jspx-iset` and `jspx-inum`. Together, these two integers identify a specific compositing instruction within a JPX Composition (`comp`) box, found within the scope of the logical target. The specific instruction in question is located in the instruction set (`iset`) box whose ordinal position (starting from 0) within the composition box is given by the `jspx-iset` value. The `jspx-inum` value gives the ordinal position (starting from 0) of the instruction within that instruction set box. The interpretation of these indices is independent of repeat counts which might appear within a JPX composition box.
+
+When `jspx-iset` and `jspx-inum` values are processed by the server, the requested frame size and region parameters `fx`, `fy`, `sx`, `sy`, `ox` and `oy`, shall first be mapped to modified frame size and region parameters `fx"`, `fy"`, `sx"`, `sy"`, `ox"` and `oy"` using the expressions in Equation C-3. These modified region parameters shall be calculated separately for each requested codestream and shall then be used in place of `fx`, `fy`, `sx`, `sy`, `ox` and `oy` when determining the codestream image resolution and the codestream image region following the procedure described in C.4.1.
+
+First, define the rotated frame size, offset, width and height of the composite image as follows:
+
+$$\begin{bmatrix} ox^F, oy^F, \\ XO_{inst}^F, YO_{inst}^F \end{bmatrix} = \begin{bmatrix} (fx - ox - sx), (fy - oy - sy), \\ (W_{comp} - XO_{inst} - Wt_{inst}), (H_{comp} - YO_{inst} - Ht_{inst}) \end{bmatrix}$$
+
+$$\begin{bmatrix} fx^\theta, fy^\theta, ox^\theta, oy^\theta, W_{comp}^\theta, H_{comp}^\theta, \\ XO_{inst}^\theta, YO_{inst}^\theta, Wt_{inst}^\theta, Ht_{inst}^\theta \end{bmatrix} = \begin{cases} \begin{bmatrix} fx, fy, ox, oy, W_{comp}, H_{comp}, \\ XO_{inst}, YO_{inst}, Wt_{inst}, Ht_{inst} \end{bmatrix} & \text{if } R_{inst} = 0^\circ \text{ | NoFlip} \\ \begin{bmatrix} fy, fx, oy, ox^F, H_{comp}, W_{comp}, \\ YO_{inst}, XO_{inst}^F, Ht_{inst}, Wt_{inst} \end{bmatrix} & \text{if } R_{inst} = 90^\circ \text{ | NoFlip} \\ \begin{bmatrix} fx, fy, ox^F, oy^F, W_{comp}, H_{comp}, \\ XO_{inst}^F, YO_{inst}^F, Wt_{inst}, Ht_{inst} \end{bmatrix} & \text{if } R_{inst} = 180^\circ \text{ | NoFlip} \\ \begin{bmatrix} fy, fx, oy^F, ox, H_{comp}, W_{comp}, \\ YO_{inst}^F, XO_{inst}, Ht_{inst}, Wt_{inst} \end{bmatrix} & \text{if } R_{inst} = 270^\circ \text{ | NoFlip} \\ \begin{bmatrix} fx, fy, ox^F, oy, W_{comp}, H_{comp}, \\ XO_{inst}^F, YO_{inst}, Wt_{inst}, Ht_{inst} \end{bmatrix} & \text{if } R_{inst} = 0^\circ \text{ | Flip} \\ \begin{bmatrix} fy, fx, oy, ox, H_{comp}, W_{comp}, \\ YO_{inst}, XO_{inst}, Ht_{inst}, Wt_{inst} \end{bmatrix} & \text{if } R_{inst} = 90^\circ \text{ | Flip} \\ \begin{bmatrix} fx, fy, ox, oy^F, W_{comp}, H_{comp}, \\ XO_{inst}, YO_{inst}^F, Wt_{inst}, Ht_{inst} \end{bmatrix} & \text{if } R_{inst} = 180^\circ \text{ | Flip} \\ \begin{bmatrix} fy, fx, oy^F, ox^F, H_{comp}, W_{comp}, \\ YO_{inst}^F, XO_{inst}^F, Ht_{inst}, Wt_{inst} \end{bmatrix} & \text{if } R_{inst} = 270^\circ \text{ | Flip} \end{cases} \quad (C-3a)$$
+
+In the above,  $W_{comp}$  and  $H_{comp}$  are the width and height of the composited image, specified in the composition box;  $Wt_{inst}$  and  $Ht_{inst}$  are the composited width and height as determined by the compositing instruction;  $XO_{inst}$  and  $YO_{inst}$  are the horizontal and vertical compositing offsets as determined by the compositing instruction;  $W_{inst}$  and  $H_{inst}$  are the width and height of the potentially cropped compositing layer as determined by the compositing instruction;  $XC_{inst}$  and  $YC_{inst}$  are the horizontal and vertical compositing layer cropping offsets as determined by the compositing instruction; and  $R_{inst}$  is derived from the ROT field of the compositing instruction, if any. If the compositing instruction contains no ROT field or the ROT field is 0,  $R_{inst}=0^\circ$ |NoFlip. Otherwise, the rotation angle for  $R_{inst}$  (expressed in degrees clockwise) is obtained from the least significant 3 bits of the ROT field defined in Rec. ITU-T T.801 | ISO/IEC 15444-2, while the Flip|NoFlip status for  $R_{inst}$  is set to Flip if bit 4 of the ROT field is non-zero and NoFlip otherwise.
+
+Then, define the modified frame size  $f_x''$ ,  $f_y''$  as follows:
+
+$$f_x'' = \left\lceil f_x^\theta \cdot \frac{X_{R_{reg}}}{X_{S_{reg}}} \cdot \frac{W_{t_{inst}}^\theta}{W_{S_{inst}}} \cdot \frac{W_{cod}}{W_{comp}^\theta} \right\rceil; \quad f_y'' = \left\lceil f_y^\theta \cdot \frac{Y_{R_{reg}}}{Y_{S_{reg}}} \cdot \frac{H_{t_{inst}}^\theta}{H_{S_{inst}}} \cdot \frac{H_{cod}}{H_{comp}^\theta} \right\rceil \quad (C-3b)$$
+
+To compute the modified region, first define the clipped region edges:
+
+$$x_{\min} = \left\lfloor X_{O_{inst}}^\theta \cdot \frac{f_x^\theta}{W_{comp}^\theta} \right\rfloor; \quad y_{\min} = \left\lfloor Y_{O_{inst}}^\theta \cdot \frac{f_y^\theta}{H_{comp}^\theta} \right\rfloor$$
+
+$$x_{\lim} = \left\lfloor \left( X_{O_{inst}}^\theta + W_{t_{inst}}^\theta \right) \cdot \frac{f_x^\theta}{W_{comp}^\theta} \right\rfloor; \quad y_{\lim} = \left\lfloor \left( Y_{O_{inst}}^\theta + H_{t_{inst}}^\theta \right) \cdot \frac{f_y^\theta}{H_{comp}^\theta} \right\rfloor \quad (C-3c)$$
+
+The modified region size  $s_x''$  and  $s_y''$  and region offsets  $o_x''$  and  $o_y''$  are then given as:
+
+$$s_x'' = \min \left\{ \left( o_x^\theta + s_x^\theta \right), x_{\lim} \right\} - \max \left\{ o_x^\theta, x_{\min} \right\}$$
+
+$$s_y'' = \min \left\{ \left( o_y^\theta + s_y^\theta \right), y_{\lim} \right\} - \max \left\{ o_y^\theta, y_{\min} \right\}$$
+
+$$o_x'' = \max \left\{ o_x^\theta, x_{\min} \right\} - \left\lfloor \left( X_{O_{inst}}^\theta - \left( X_{C_{inst}} - \frac{X_{O_{reg}}}{X_{S_{reg}}} \right) \cdot \frac{W_{t_{inst}}^\theta}{W_{S_{inst}}} \right) \cdot \frac{f_x^\theta}{W_{comp}^\theta} \right\rfloor$$
+
+$$o_y'' = \max \left\{ o_y^\theta, y_{\min} \right\} - \left\lfloor \left( Y_{O_{inst}}^\theta - \left( Y_{C_{inst}} - \frac{Y_{O_{reg}}}{Y_{S_{reg}}} \right) \cdot \frac{H_{t_{inst}}^\theta}{H_{S_{inst}}} \right) \cdot \frac{f_y^\theta}{H_{comp}^\theta} \right\rfloor \quad (C-3d)$$
+
+The modified view-window region, defined by  $s_x''$ ,  $s_y''$ ,  $o_x''$  and  $o_y''$ , can potentially lie slightly to the left or above the origin. That is,  $o_x''$  and/or  $o_y''$  may be negative. Any portion of the view-window region which lies to the left or above the origin should be ignored when determining the codestream image region following the procedure described in C.4.1.
+
+If `jpx-iset` and `jpx-inum` values are not supplied, the modified region parameters to be used in place of  $f_x$ ,  $f_y$ ,  $s_x$ ,  $s_y$ ,  $o_x$  and  $o_y$  are given by the expressions in Equation C-4. As before, these modified parameters shall be used when determining the codestream image resolution and the codestream image region, following the procedure in C.4.1.
+
+$$f_x'' = \left\lceil f_x \cdot \frac{X_{R_{reg}}}{X_{S_{reg}}} \cdot \frac{W_{cod}}{W_{reg}} \right\rceil; \quad f_y'' = \left\lceil f_y \cdot \frac{Y_{R_{reg}}}{Y_{S_{reg}}} \cdot \frac{H_{cod}}{H_{reg}} \right\rceil$$
+
+$$o_x'' = o_x - \left\lfloor \frac{X_{O_{reg}}}{X_{S_{reg}}} \cdot \frac{f_x}{W_{reg}} \right\rfloor; \quad o_y'' = o_y - \left\lfloor \frac{Y_{O_{reg}}}{Y_{S_{reg}}} \cdot \frac{f_y}{H_{reg}} \right\rfloor \quad (C-4)$$
+
+$$s_x'' = s_x; \quad s_y'' = s_y$$
+
+The second type of `context-range` described by this Recommendation | International Standard, `mj2t-context`, allows clients to request specific tracks from an MJ2 or J2KS file. The `mj2-track` identifier shall be a strictly positive integer, since 1 is the smallest allowable track identifier permitted within an MJ2 or J2KS file. If an `mj2-track` identifier includes the optional "+now" suffix, the `mj2t-context` consists of all codestreams belonging to the MJ2 or J2KS video track, starting with the codestream whose capture time corresponds to the time at which the request is received. This is useful when the source is a live video stream. Otherwise, the server can associate "now" with any codestream it sees fit. If the "+now" suffix is not included, the `mj2-context` consists of all codestreams belonging to the MJ2 or J2KS video track.
+
+An `mj2t-context` can specify a coordinate remapping transformation, to be used in deducing codestream image resolutions and codestream image regions for each of its codestreams. If not present, the frame size and region parameters supplied via Frame Size, Offset and Region Size request fields shall be interpreted directly following the procedure outlined in C.4.1. Otherwise, one of two types of coordinate transformation is being requested, as identified by the appearance of one of the "track" or "movie" tokens.
+
+Where "track" is specified, the Frame Size, Offset and Region Size request fields are being used to identify a desired presentation size and a desired rectangular region within the smallest bounding rectangle which contains the track's presentation, at this desired presentation size. The geometric transformations described by the MJ2 Track Header (tkhd)
+
+box shall be applied to determine a corresponding image resolution and region on each codestream associated with the track.
+
+Where "movie" is specified, the Frame Size, Offset and Region Size request fields are being used to identify a desired size for the entire (possibly composited) reproduced movie, and a desired rectangular region within the smallest bounding rectangle which contains the movie, at this desired size. The geometric transformations described by the Track Header (tkhd) box shall be combined with the geometric transformations described by the Movie Header (mvhd) box and applied to determine a corresponding image resolution and region on each codestream associated with the track.
+
+In the event that a server is unable to apply any of the `mj2t-context` geometric transformations described above, it provides a modified `mj2t-context` string in its Codestream Context response header.
+
+NOTE 1 – The use of the Codestream Context request field together with the Codestream request field can result in a codestream being requested multiple times with different geometric transformations of the Frame Size, Region Size and Offset request fields. Where this happens, multiple disjoint or overlapping image portions of that codestream are effectively being requested.
+
+NOTE 2 – The expressions in Equation C-4 can equivalently be obtained by setting  $X_{Scomp}=W_{Sinst}=W_{tinst}=W_{reg}$ ,  $Y_{Scomp}=H_{Sinst}=H_{tinst}=H_{reg}$  and  $XO_{inst}=YO_{inst}$  in Equation C-3 when the limits on  $sx$ ,  $sy$ ,  $ox$  and  $oy$  are not bounded by  $x_{lim}$ ,  $y_{lim}$ ,  $x_{min}$ ,  $y_{min}$ .
+
+The third type of context-range described by this Recommendation | International Standard, `jpm-context`, allows clients to request specific layout objects from a JPM file. The simplest usage allows a request to be made for all the items needed to render a single page. More complex usage allows only some of the layout objects or only one type of object to be requested. The `jpm-context` always contains a request for specific pages, it can also contain a specification for page collections, a list of layout objects, and object types.
+
+If `jpm-context` has no `jpm-page-collection` item then the main page collection is assumed. If `TEXT-LABEL` is specified in the `jpm-page-collection` item it shall correspond to a label of a page collection box in the target JPM file. If `UINT` is specified in the `jpm-page-collection` item it indicates the page collection box in that position in file, where page collection boxes are numbered from 0.
+
+A range of pages is a required part of the `jpm-context`. The page range could be "0-" which would specify all the pages in the page collection. Pages are numbered by following the page collections and pages in the JPM file, and assigning the number 0 to the first page in a depth first tree walk. The root of the tree is given by the `jpm-page-collection` item or the main page collection if no `jpm-page-collection` is part of the request. Loops in the page collection tree should be detected and an error condition returned.
+
+If a "sampling-factor" is used as part of the `jpm-sampled-range`, the client desires pages starting with the first number in each range, and less than or equal to the last number in the range, and at all integer multiples of the sampling-factor plus the initial page number. Thus two sampling ranges it is possible to request even and odd number pages using a sampling-factor of 2, by starting each range with an even or odd number.
+
+If the `jpm-context` has no `jpm-object-range` item then it is considered to be "1-" which corresponds to all objects on the page except the thumbnail. If the thumbnail image for a page is needed then the `jpm-object-range` item shall include zero. The `jpm-object-range` indicates which of the layout objects on all pages in the `jpm-page-range` are requested.
+
+If the `jpm-context` has no `jpm-object-type` then all types are used. If the `jpm-object-type` is "mask" only mask objects are of interest for the request. If the `jpm-object-type` is "image" only image objects are of interest. If the `jpm-object-type` is "nostrm" then boxes for both mask and image are of interest.
+
+If the `jpm-context` parameter appears in a request without a Frame Size request (`fsiz`) then the Frame Size values  $fx$  and  $fy$  are set to the page width and page height. If the `e` parameter appears in a request without a Region Size request (`rsiz`) then the Region Size values  $sx$  and  $sy$  are set to the frame size values  $fx$  and  $fy$  (after  $fx$  and  $fy$  have been set to the page width and height if necessary).
+
+When the `jpm-context` parameter is used, the requested corresponds to the view-window applied to each page independently. The Frame Size values  $fx$  and  $fy$  are mapped to the page width and height as specified by the `Pwidth` and `Pheight` elements of the Page Header Box of Rec. ITU-T T.805 | ISO/IEC 15444-6.
+
+A layout object within a page is considered part of the request if and only if all of the following are true:
+
+$$\begin{array}{ll} ox' \leq LHoff + LWidth & ox' + sx' \geq LHoff \\ oy' \leq LVoff + LHeight & oy' + sy' \geq LVoff \end{array}$$
+
+where:
+
+$$\begin{array}{l} ox' = ox * Pwidth / fx \\ oy' = oy * Pheight / fy \\ sx' = sx * Pwidth / fx \end{array}$$
+
+$$sy' = sy * Pheight / fy$$
+
+and  $fx$ ,  $fy$ ,  $ox$ ,  $oy$ ,  $sx$ , and  $sy$  are from the view window requests,  $LHoff$ ,  $LVoff$ ,  $LHeight$ , and  $LWidth$  are from the Layout Object Header Box of Rec. ITU-T T.805 | ISO/IEC 15444-6.
+
+Layout object 0 is reserved for a thumbnail image of the page, it should be considered part of the request regardless of the view-window if and if 0 is included in `jpm-object-range`.
+
+The client is considered to have requested any codestream associated with the mask or image which intersects the view-window unless `jpm-object-type` is "nostrm". If the codestream is not compressed with JPEG 2000 then the request is for the complete codestream. If the codestream is compressed with JPEG 2000 then an equivalent view-window can be determined for the specific codestream by mapping the request window on the page to the request window on the object as follows:
+
+$$\begin{aligned} fx' &= fx * Lwidth / Pwidth \\ fy' &= fy * Lheight / Pheight \\ ox' &= \text{MAX}( ox - LHoff * fx / Pwidth , 0) \\ oy' &= \text{MAX}( oy - LVoff * fy / Pheight, 0) \\ sx' &= \text{MIN}( ox + sx - LHoff * fx / Pwidth, Lwidth * fx / Pwidth) - ox' \\ sy' &= \text{MIN}( oy + sy - LVoff * fy / Pheight, Lheight * fy / Pheight) - oy' \end{aligned}$$
+
+Note that it might be necessary to issue a frame-size request with values larger than the width and height of the page in order to obtain a full resolution JPEG 2000 codestream if the JPEG 2000 file contains data at a higher resolution than the page. Alternatively, the client could determine the codestream number and issue a request directly on that codestream with a view-window chosen appropriately.
+
+EXAMPLE 1: "context=jpxl<0-4:2>[s5i2]"
+
+In this case, the server is requested to return the codestreams which are used by JPX compositing layers 0, 2 and 4, remapping the requested frame size and image region according to the geometric adjustments represented by the third instruction of the sixth instruction set box within the composition box (JPX files have at most one composition box).
+
+EXAMPLE 2: "stream=0&context=mj2t<1+now>[track]"
+
+In this case, the server is requested to return codestream 0, as well as all codestreams belonging to the first track of an MJ2 file, starting from the codestream whose sampling time corresponds to the current time. Moreover, the server is requested to remap the requested frame size and image region according to the geometric adjustments described in the Track Header box, disregarding any additional geometric adjustments which might be described in the Movie Header box.
+
+EXAMPLE 3: "context=jpmp<0-10,21-30:2>[1-3:mask]"
+
+In this case, the server is requested to return all data corresponding to mask objects in the first three layout objects on the pages 0, 2, 4, 6, 8, 10, 21, 23, 25, 27, and 29. This request includes all boxes necessary to render the desired region, e.g. Page Boxes, Layout Object Boxes, as well as any codestreams referenced by those objects.
+
+For JPM files, the following metadata elements shall be considered to be requested along with the view-window:
+
+- JP2 signature ("jP")
+- File type ("ftyp")
+- Compound Image Header ("mhdr")
+- Page Collection box ("pcol")
+- Page Table box ("pagt")
+- Page box ("page")
+- For pages that are relevant with the view-window request:
+  - Page Header box ("phdr")
+  - Layout Object box ("lobj")
+  - Layout Object Header box ("lhdr")
+  - Object box ("objc")
+  - Object Header box ("ohdr")
+  - Object Scale box ("scal")
+  - Base Colour box ("bclr")
+
+The above considerations, especially Equations C-3 and C-4, valid for two-dimensional image data only. They are extended naturally to higher dimensions by duplicating the computations for each additional dimension. Usage of the
+
+codestream context field is discouraged if the target of the request contains codestreams with differing numbers of dimensions, and servers cannot be expected to handle this case.
+
+A `jpxf-context-range` can be used to compactly identify a range of compositing layers and coordinate remapping transformations which could alternately be identified via a `jpxl-context-range`. The equivalent `jpx-layers` and `jpxl-geometry` values can be obtained by expanding composited frames into their constituent JPX compositing layers and compositing instructions in the manner described below.
+
+If the logical target does not contain a JPX Composition box, the server shall ignore any `jpxf-context-range`. Otherwise, the instructions found within the JPX Composition box together describe a sequence of composited frames, as described in Rec. ITU-T T.801 | ISO/IEC 15444-2. These composited frames are numbered  $f = 0, 1, \dots, F_{\text{comp}}-1$  and are considered to belong to a base presentation thread  $t = 0$ . If the logical target also contains Composition layer extensions ("jplx") boxes, these boxes might contribute additional presentation threads. As explained in Rec. ITU-T T.801 | ISO/IEC 15444-2, a Compositing Layer Extensions box contributes  $T_{\text{jclx}}$  presentation threads, each of which has the same number of composited frames,  $F_{\text{jclx}}$ , where the values of  $T_{\text{jclx}}$  and  $F_{\text{jclx}}$  for each Compositing Layer Extensions box are specified by its Compositing Layer Extensions Info sub-box. Together, the collection of all Compositing Layer Extensions boxes in the logical target defines  $T$  global presentation threads, where  $T$  is the maximum of the associated  $T_{\text{jclx}}$  values. For each  $t$  in the range 1 through  $T$ , global presentation thread  $t$  consists of the  $F_{\text{comp}}$  composited frames from the Composition box, followed by the  $F_{\text{jclx}}$  frames defined by compositing group  $g = \min\{t, T_{\text{jclx}}\}$  of each successive Compositing Layer Extensions box for which  $T_{\text{jclx}}$  is non-zero.
+
+If no `jpx-thread` value is supplied, or `jpx-thread` is 0, the `jpxf-context-range` includes only those composited frames contributed by the Composition box whose indices  $f$  match `jpx-frame-indices`; there are at most  $F_{\text{comp}}$  of these. Otherwise, the `jpxf-context-range` includes all composited frames from global presentation thread  $t = \min\{T, \text{jpx-thread}\}$  whose indices  $f$  match `jpx-frame-indices`.
+
+### C.4.11 Sampling Rate (srate)
+
+```
+srate = "srate" "=" streams-per-second
+streams-per-second = UFLOAT
+```
+
+If this field is supplied, the codestreams which belong to the view-window are obtained by subsampling those mentioned by the Codestream request field, in addition to those expanded from context-range values in the Codestream Context request field (see C.4.10), so as to achieve an average sampling rate no greater than the streams-per-second value. This is possible only if the codestreams have associated timing information (e.g., if they belong to a logical target conforming to the MJ2 or J2KS file formats).
+
+This request field serves only to determine which codestreams should be considered to belong to the view-window. The server shall scan through all codestreams which would otherwise be included in the view-window, discarding codestreams as required to ensure that the average separation between codestream source times is no less than the reciprocal of the streams-per-second value. This Recommendation | International Standard does not prescribe an algorithm for subsampling, or a precise interpretation for the term "average separation."
+
+If no source timing information is available, the view-window will consist of all codestreams identified via the Codestream request field and the Codestream Context request field, but this request field can nonetheless affect the interpretation of a Delivery Rate request field, if present.
+
+### C.4.12 ROI (roi)
+
+```
+roi = "roi" "=" region-name
+region-name = 1*(DIGIT / ALPHA / "_") / "dynamic"
+```
+
+This field specifies the desired spatial region of the image through a name rather than through coordinates. The mapping between `region-name` and a specific spatial region of the image can come from several places; it can be defined within an ROI description box within the logical target, or it can be defined within the implementation of the server itself.
+
+A `region-name` value of "dynamic" (a dynamic ROI) is reserved to represent a non-constant region within the image that is mapped to a spatial region independently for each and every request. The server can use any information about the client and any other request parameters when it determines what spatial region it will provide for that particular request. For example, if the server knows that the physical display on the client is very small, it can choose to provide only the foreground region of the image at a higher resolution rather than the entire region of the image at a lower resolution. Servers are not required to support dynamic ROIs.
+
+If an ROI field exists, and the server knows how to handle the ROI request, then the ROI field takes precedence over the Offset request field and the Region Size fields, which shall be ignored by the server. If an ROI field exists, but the server
+
+does not know how to handle it for any reason, the server shall ignore the ROI field and use the Offset and Region Size fields. If these fields are omitted, the default values of those fields shall be used.
+
+If the client specifies a Frame Size as well as an ROI, and the server understands the ROI specified, the value of the Frame Size request field determines the image resolution at which the ROI is requested.
+
+### C.4.13 Layers (layers)
+
+```
+layers = "layers" "=" UINT
+```
+
+This field can be used to restrict the number of codestream quality layers that belong to the view-window request. By default, all available layers are of interest. The value specifies the number of initial quality layers that are of interest. The server should not attempt to augment any precinct data-bins beyond the relevant layer boundary. The server should not attempt to augment any tile data-bins beyond the point at which all remaining contents lie beyond the relevant layer boundary. Due to the order of data within a tile, it might be necessary for the server to return data beyond the boundary of the requested layer for JPT-stream requests only.
+
+### C.4.14 Multi-component transformation (MCT) Resolution Value
+
+```
+mctres = "mctres" "=" UINT
+```
+
+This field specifies the desired multi-component transformation resolution level. This field is only applicable if for all tile-components, exactly one of the multi-component transformations that are applied on this tile-component (and iteratively on the resulting intermediate components to create generated components) is a multi-component wavelet-transformation. It shall not be used otherwise. If this field is not present, it will be assumed that the full resolution representation of the image data is desired. The full number of resolution levels is one more than the number of wavelet transform levels  $N_L$  in the multi-component transformation, given by  $Tmcc^i$  (see Rec. ITU-T T.801 | ISO/IEC 15444-2). For full resolution, this field should be set to 1. For half resolution, the field should be set to 2, for quarter resolution, the field should be set to 3, etc. If the value of *mctres* exceeds  $N_L + 1$  for one tile or codestream, the lowest available resolution of that tile or codestream shall be transmitted. The same value of *mctres* shall apply simultaneously to all multi-component wavelet transformations found in the codestream(s).
+
+Usage of the *mctres* field in combination with the Frame, Region or Region Offset request field for Variable Dimension Data with three or more numerical arguments on Rec. ITU-T T.801 | ISO/IEC 15444-2 codestreams is discouraged and servers cannot be expected to handle it.
+
+## C.5 Metadata request fields
+
+### C.5.1 Metadata requested implicitly with view-window requests
+
+The Codestream request field and the Codestream Context request field identify one or more codestreams which are associated with the requested view-window. Even if neither of these request fields is present, the view-window is associated with at least one codestream, as mentioned in C.4.9. Moreover, as noted in C.4.2, even if the Frame Size request field is omitted, the requested view-window includes at least the main codestream header for each requested codestream. The only exception to this is when *metadata-only* is specified in a Metadata request field (see C.5.2). Except in this case, the client is also implicitly requesting whatever metadata boxes might be required from the file format, if any, in order to utilize the imagery represented by the requested codestreams. To ensure interoperability between client and server components, this subclause identifies a minimal set of metadata which servers shall regard as being implicitly requested along with the view-window.
+
+NOTE – The list of boxes defined in this clause is not exhaustive. Additional boxes might be required to decode the requested view window within the logical target correctly.
+
+For JP2, JPH and JPX files, the following metadata elements shall be considered to be requested along with the view-window:
+
+- a) The entire contents of metadata-bin 0.
+- b) The entire contents of each of the following boxes, wherever they are found at the top level of the file:
+  - 1) JP2 Signature ("jP ");
+  - 2) File Type ("ftyp");
+  - 3) Reader Requirements ("rreq");
+  - 4) Composition ("comp").
+- c) All immediate sub-box headers from each of the following superboxes:
+  - 1) any JP2 Header ("jp2h") box;
+  - 2) any Codestream Header ("jpch") box associated with a requested codestream;
+
+- 3) any Compositing Layer Header ("jplh") box associated with a JPX compositing layer requested via the Codestream Context request field.
+- d) The entire contents of each of the following boxes, wherever these boxes are found within one of the superboxes mentioned above:
+  - 1) Image Header ("ihdr");
+  - 2) Bits per Component ("bpc");
+  - 3) Palette ("pclr");
+  - 4) Component Mapping ("cmap");
+  - 5) Channel Definition ("cdef");
+  - 6) Resolution ("res ");
+  - 7) Codestream Registration ("creg");
+  - 8) Opacity ("opct").
+- e) For JP2 files, JP2 compatible files and JPX files, one or more Colourspace Description boxes ("colr") associated with each codestream or JPX compositing layer requested via the Codestream Context request field, as follows:
+  - 1) If the server is able to determine exactly which box is preferred, the server should send only that box, even if it means not sending the first box for JP2 or JP2 compatible files (for example if the second box is Any ICC and the colorspace preferences specify that the client prefers Any ICC). If the server is not able to determine exactly which box is preferred, it should send the entire first Colourspace Description box.
+  - 2) For all boxes not sent, the server should send a portion of the box contents so the client can determine if it later wants to request another colourspace specification.
+    - For enumerated boxes, the server should send at least the first 7 bytes of the box contents (up to at least the EnumCS field).
+    - For vendor-defined colourspace boxes, the server should send at least the first 19 bytes of the box contents (up to at least the VCLR field).
+    - For Restricted and Any ICC colourspace boxes, the server should send at least the first 3 bytes of the box contents (at least the METH, APPROX and PREC fields).
+
+The server is requested to return an initial prefix of each metadata-bin which contains any of the metadata mentioned above, extending from the first byte of the metadata-bin and continuing to the end of all requested metadata from that metadata-bin. As a result, the actual amount of metadata returned by the server can depend upon the particular way in which the logical target has been partitioned into metadata-bins. A discussion of these issues can be found in A.3.6.2.
+
+For MJ2 files, the following metadata elements shall be considered to be requested along with the view-window:
+
+- JP2 signature ("jP")
+- File type ("ftyp")
+- "mvhd"
+- For tracks that are relevant with the view-window request:
+  - "tkhd"
+  - edts[0]. Only the TBox field is useful, and a placeholder signals that no access is provided to the original content of the box.
+  - "mdhd"
+  - "hdlr"
+  - "vmhd" if present in the original MJ2 file.
+  - "stsd"
+  - "stts"
+  - either:
+    - a placeholder for "stco" or "stco64" (depending on which of them is present in the original MJ2 file) indicating that the content of the box is provided by one or more incremental codestreams;
+    - or the entire "stsc", "stsz" and "stco" or "stco64" boxes.
+
+Similar considerations apply to J2KS files.
+
+### C.5.2 Metadata Request (metareq)
+
+```
+metareq = "metareq" "=" 1#([" 1$(req-box-prop) "]" [root-bin] [max-depth])
+                                         [metadata-only]
+
+req-box-prop = box-type [limit] [metareq-qualifier] [priority]
+
+limit = ":" (UINT / "r")
+
+metareq-qualifier = "/" 1*("w" / "s" / "g" / "a")
+
+priority = "!"
+
+root-bin = "R" UINT
+
+max-depth = "D" UINT
+
+metadata-only = "!!"
+```
+
+This field specifies what metadata is desired in response to a request, in addition to any metadata required for the client to decode or interpret the requested image data as defined by C.5.1. The purpose of this request is to allow the client to request selected parts of the contents and the layout of the metadata encoded in the JP2, JPH and JPX file formats a server did not choose to transmit according to C.5.1.
+
+The value string in this request field is a list of independent requests; however, the server can handle the requests as a group, and there can be overlap between the requests. It is then sufficient (but not necessary) that the server sends the requested data only once.
+
+The way the server decides to break up the initial stream into bins is irrelevant for defining the target of the request except that the `root-bin` field can be used to limit a request to parts of the file structure, once a client has identified the layout. Once a request is confined to a specific bin, the way that bin is broken up into more bins – or if it is broken up at all – is irrelevant for the client and the way that data is addressed within the request.
+
+However, data that a server returns upon a request will, in general, depend on that layout because the division of the logical target into metadata-bins might force the server to return additional data, including the contents or headers of some other, potentially unrequested boxes. All a server has to ensure is that **at least** the requested data is contained, and that **enough** data is returned to allow a client to parse it. Examples when additional data needs to be returned are given below in C.5.2.9. The following text uses the wording "request" to point out which data is **desired** by the client, which might be a sub-set of the data actually returned by the server due to reasons pointed out in C.5.2.9.
+
+##### Example
+
+For better illustration, examples in the following subclauses all refer to the following segment of a JPX file, see Rec. ITU-T T.801 | ISO/IEC 15444-2 for the definition of the boxes used here. The labels on the right-hand side have been added for later reference:
+
+| Content                             | Label |
+|-------------------------------------|-------|
+| association box header ('asoc')     | A     |
+| number list box header ('nlst')     | B     |
+| number list box content             | C     |
+| association box header ('asoc')     | D     |
+| ROI description box header ('roid') | E     |
+| ROI description box content         | F     |
+| association box header ('asoc')     | G     |
+| label box header ('lbl\040')        | H     |
+| label box content                   | I     |
+| XML box header ('xml\040')          | J     |
+| XML box content                     | K     |
+
+The sub-box structure of the above example is indicated by indentation, e.g., items H to K establish the contents of the superbox at label G.
+
+#### C.5.2.2 root-bin
+
+Each request is relative to the data-bin specified by its `root-bin` value. If a `root-bin` value is not specified, the root is meta-data bin 0. The request pertains only to data within or referenced by that particular data-bin.
+
+##### Example
+
+If the server decided to place the contents of association box 'A' in the above example into a separate bin with bin id #3, the association box header 'A' would be encoded in a placeholder box, and items 'B' to 'K' would establish bin #3. In that case, a root-bin field of 3 would limit the scan to items 'B' to 'K' only. Specifically, `metareq=[roid]R3` would request items 'E' and 'F' from the server and no other data outside of this example (but see also clauses C.5.2.3 and C.5.2.9 for additional data outside of the request potentially returned by the server along).
+
+An alternative layout might be to include items 'B' to 'G' in bin #3 as above, but in addition place items 'H' to 'K' into the separate bin #4. Thus 'G' would be represented by a placeholder box in bin #3 and 'H' to 'K' would be part of bin #4. A root-bin field of 3 would still scan the items 'H' to 'K' because they are referenced by a placeholder in bin #3 and the way how bin #3 is broken up into sub-bins is irrelevant to the request. Thus, even though the server response would be different, the items identified by the request remain the same.
+
+A root-bin field of 0 imposes no further restriction on the request each item, box or superbox, is somehow reachable from the metadata-bin #0. Whether placeholder boxes are used or not is completely irrelevant. Thus, `metareq=[roid]` would request all ROI description boxes from the server, and thus also include items 'E' and 'F' along with all other ROI description boxes available.
+
+#### C.5.2.3 max-depth
+
+If a value for `max-depth` is specified, then only boxes contained within the root metadata-bin, and those no more than `max-depth` levels in the file hierarchy below that box are requested. If a value for `max-depth` is not specified, there is no limit on the depth of the file hierarchy for this request.
+
+##### Example
+
+If items 'B' to 'K' establish the contents of metadata-bin #3 as in the example for C.5.2.1, the root-bin field is set to 3 and `max-depth` is set to 0, then the request is limited to items 'B' to 'D'. If `max-depth` is set to 1, the request is limited to items 'B' to 'G'.
+
+The request `metareq=[roid]R3D0` would therefore not request any data from the server because the only ROI description box within the specified bin is one level below the start of bin #3. The request `metareq=[asoc]R3D0` would request the association box starting at label 'D' and its contents, items 'E' to 'K'. This request is identical to `metareq=[asoc]R3D3` because, even though the latter example also requests the association box starting at label 'G', this box is part of the box starting at label 'D' and is thus included in the former request anyhow.
+
+#### C.5.2.4 I-box-prop
+
+The `req-box-prop` portion of the request specifies a list of box types that are of interest to the client. The special string "\*" can be substituted for the box type, in which case all box types are implied. Thus, this field confines the request to apply only to the specific box type (or types) listed and instructs the server to deliver the box header and box contents of all matching boxes within all additional constraints.
+
+The contents of a superbox is defined by its complete sub-box hierarchy. This implies that in case superboxes match the box type, the complete sub-box hierarchy of the matching superbox is requested, regardless of the `max-depth` field.
+
+##### Example
+
+Consider again the example layout of C.5.2. Then, a `req-box-prop` of type 'asoc' would include all items 'A' to 'K' in the request because they establish the content of the matching box defined at label 'A'. Note that, once the association box at label 'A' has been identified to match the request, the depth limit does not limit the delivery of its contents. A `req-box-prop` of type 'lbl\040' would only include items 'H' and 'I', along with all other label boxes, provided they match all other specifications of the request, e.g., are contained in the addressed root bin above the depth-limit.
+
+The request `metareq=[*]R3D0` instructs the server to return the entire contents of all boxes it finds in the contents of bin 3, and thus requests items 'B' to 'K'. While a restriction on the desired depth has been specified, the server shall ignore that restriction because items 'E' to 'K' are part of the box starting at label 'D' and no other constraints apply.
+
+#### C.5.2.5 limit
+
+The limit attribute optionally following the `req-box-prop` field further confines the type of request, and how many bytes of the box contents identified by the `req-box-prop` field the client is interested in. The limit parameter takes the form of a colon followed by either an unsigned integer (the limit value) or the character "r". The same limit value applies to all boxes that match the `req-box-prop` of which it is an attribute. If it is not present, the client is requesting all matching boxes entirely.
+
+If the limit field is an integer  $n$  greater than zero, then the server is requested to return the unlimited box header and only the first  $n$  bytes of the box content of the matching boxes. The byte count is here defined to count the data as it appeared in the original file before it was broken up into bins.
+
+Furthermore, if `req-box-prop` matches any superboxes, the contents of a superbox is to be understood as the complete and unlimited sequence of box headers and box contents contained within that superbox, and the byte limit by that also counts the box headers of all boxes contained within the matching super box. It might thus happen that the limit field instructs the server to deliver only parts of a (sub-)box header even though the full header of the matching box itself is always included. However, using the limit field in this way is discouraged and should be avoided.
+
+If the limit field is zero, only the box headers of the matching boxes are requested.
+
+If the limit value is "`r`", then the server is requested to deliver the minimum data required to reconstruct the box-headers of all matching boxes, as well as the minimum data to reconstruct the box-headers of all of its descendant sub-boxes up to the maximum depth specified, regardless of their box-type. As an exception, `max-depth` does apply for the limit value "`r`" to limit the contents of superboxes, which makes this type of request special as far as the interpretation of `max-depth` is concerned.
+
+##### Example
+
+Consider again a file layout as in C.5.2 above with items 'B' to 'K' in data bin #3 and the metadata request `metareq=[asoc:8]R3D1`. By that, the client requires the box header and the first eight bytes of every association box found in bin #3 not deeper than one level from bin #3. In the example at hand, this requests the item 'D', eight bytes from item 'E', namely the part of the first sub-box of 'D' that fits into the limit because it establishes the contents of 'D', the item 'G' because it is exactly one level below the first item 'B' of the bin, and eight bytes of the box content contained in the superbox starting at 'G', that is the first eight bytes of the box header 'H'. Should the box headers 'E' and 'H' not fit into eight bytes, they might get truncated. This is why usage of the numerical limit field on superboxes is discouraged.
+
+Consider the request `metareq=[roid:1]R3D1`. This will request the box header of the ROI description box at label 'E' one level below the start of the bin, and in addition the first byte of its contents at point 'F', which happens to be the number of regions encoded in the box (see Rec. ITU-T T.801 | ISO/IEC 15444-2). If the example would contain a ROI description box at a deeper level, it would not be requested here due to the depth limit.
+
+The request `metareq=[asoc]R3D0` does not contain a limit, and thus requests the complete body of any association box found at the box level of metadata-bin #3. Even though the association box at label 'G' is outside the depth-limit, it is still requested because it is contained in the association box started at point 'D', and by that items 'D' to 'K' are transmitted completely.
+
+The "`r`" limit is in effect a request for a skeleton of a portion of the box hierarchy because it only supplies the minimum data, namely the box headers, to reconstruct the structure of the boxes. The request `metareq=[asoc:r]R3D1` thus requests the items at label 'D', 'E' and 'G', but not 'H' and 'J' because they are outside the depth-limit. Item 'A' is not part of bin #3 in the example set-up, and is thus neither requested.
+
+The difference between the limit "`0`" and the limit "`r`" is that the former only delivers the box header of all matching boxes, but not necessarily their depending sub-boxes. The "`r`" limit, however, extends the request to the box-headers of the sub-structure of the matching box up to the depth-limit.
+
+#### C.5.2.6 metareq-qualifier
+
+The "`metareq-qualifier`" takes the form of a "/" followed by one or more of the flags "`g`", "`s`", "`w`" and "`a`". Each flag identifies a context from which boxes which match the request shall be drawn. Thus, the "`metareq-qualifier`" defines an additional constraint on the boxes besides the box-type. The interpretation for each of these contexts is supplied in Table C.2. If more than one of the flags is provided, the union of the corresponding contexts shall be taken.
+
+The contexts "`g`", "`s`" and "`w`" are mutually exclusive, but their union is generally smaller than the catch-call context "`a`". It is at the discretion of the server to decide which box falls into which context, and no classification of box types is defined in this Recommendation | International Standard.
+
+Table C.2 – Metadata request qualifier flags
+
+| Flag                                                                                                                               | Interpretation                                                                                                                                                                                                                                                                                                                                                                                                                            |
+|------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| "w"                                                                                                                                | This metareq context includes all boxes which are known to be associated with a specific spatial image region within one or more codestreams which belong to the view-window, where the spatial region, resolutions and the image components to which the boxes relate intersect with those of the view-window. Such an association might, for example, be established by an "asoc" box in a JPX file.                                    |
+| "s"                                                                                                                                | This metareq context includes all boxes which are known to be associated with one or more codestreams which belong to the view-window, or with one or more of the requested codestream contexts (e.g., JPX compositing layers, MJ2 or J2KS video tracks or JPM pages), where these boxes are not solely associated with particular spatial regions. Such an association might be established by an "asoc" box in a JPX file, for example. |
+| "g"                                                                                                                                | This metareq context includes all boxes which are relevant to the requested view-window, taking into account the requested codestreams and the requested codestream contexts, excluding those boxes which are included in the "w" and "s" metareq contexts.                                                                                                                                                                               |
+| "a"                                                                                                                                | This metareq context includes all boxes in the logical target, without exception (Note).                                                                                                                                                                                                                                                                                                                                                  |
+| NOTE – This metareq context is suitable for requests that wish to interrogate the file structure independently of the view-window. |                                                                                                                                                                                                                                                                                                                                                                                                                                           |
+
+#### C.5.2.7 priority
+
+If the "priority" flag is specified, then the client is requesting that the data collected by the meta-data request has to be transmitted with higher priority (i.e., upfront) than the image data described by other fields of the same request.
+
+#### C.5.2.8 metadata-only
+
+If "metadata-only" is specified at the end of the meta-data request field, the client is requesting that the server's response consists only of meta-data, without any image data or codestream headers, regardless of whether view-window request fields such as Frame Size have been used. For JPP-stream and JPT-stream return types, this means that the returned JPIP messages will all be metadata-bin messages. This field also disables the request of the silently implied meta-data defined by C.5.1.
+
+#### C.5.2.9 Implications of layout-constraints
+
+Regardless of the box specifications provided via the Metadata Request field, the server may send other data, either because it has determined that the other data is required for the client to decode or interpret the requested image data, or because the server had previously divided the logical target into data-bins using different criteria, and additional data shall be sent in order to provide a consistent and meaningful view of the metadata-bins for this logical target.
+
+To make the delivered data parseable to a client, all data from the start of the bin up to the last byte required to satisfy the request has to be known by the client, and thus has to be transmitted provided it is not already within the cache of the client. In addition, should any data that matches the request be relocated into additional bins by means of placeholder boxes, the complete placeholder box and the bytes of the bin referenced by the placeholder box has to be included in the request. Byte counts, as used by the limit attribute, always count bytes **as found in the original stream** and not as it was broken up by the server. This means that the number of bytes actually being transmitted back to the client might be different from the number of bytes implied by the byte-limit, because not only placeholder boxes have to be transmitted, but also the data in front of the requested bytes within the bin the bytes are located in might have to be included to make the resulting stream parseable.
+
+Regardless of the box specifications provided via the metareq request field, the server may send other data, either because it has determined that the other data is required for the client to decode.
+
+##### Example
+
+Consider again the data as found at the beginning of C.5.2 and assume the server decided to place all of the data into metadata-bin #3 without making use of any (additional) placeholder boxes. Also assume that the cache of the client is empty. Then the metadata-request `metareq=[xml\040:r]R3` is requesting only the box header of the XML box at label 'J'. However, since the bin is not broken up into more bins, all bytes in front of item 'J' are also required by the client to parse this data successfully and to identify the transmitted data as a box header, and thus the server is required to send all data from 'B' to 'J'.
+
+As the above example suggests, not using placeholders might be considerably inefficient for some requests. The following alternative layout at the server side provides a more efficient access to the same data:
+
+The association boxes at 'D' and 'G' are broken up into separate bins with the bin-ids #4 and #5, respectively. Then for the very same request, the server would have to transmit the placeholder box for item 'D' in bin #3, the placeholder box for
+
+item 'G' in bin #4 and the requested box header 'J' now located at the start of bin #5. Note that the request automatically pertains to bins #4 and #5, since they are referenced by placeholders in bins #3 and #4 respectively. Depending on the size of the remaining boxes, this layout might be considerably more efficient.
+
+#### C.5.2.10 Special considerations for cross-reference boxes
+
+If any cross-reference boxes are identified by a metadata request, the server shall also include in its response such additional metadata as might be required for the client to determine the metadata-bins, if any, which contain the original file byte contents that are referenced by such cross-reference boxes.
+
+If a cross-reference box has a streaming equivalent placeholder, the placeholder box itself provides the identity of a metadata-bin which contains the original cross-referenced content. Otherwise, the server is required to send at least the box header (or corresponding placeholder boxes) for every box in the original file which contains data referenced by the cross-reference box.
+
+## C.6 Data limiting request fields
+
+### C.6.1 Maximum Response Length (len)
+
+```
+len = "len" "=" UINT
+```
+
+This field specifies a restriction on the amount of data, in units of bytes, that the client requests from the server. For JPP and JPT image return types, the limit includes payload and VBAS headers. The EOR message (header and body, see Annex D) does not contribute to the limit.
+
+If the `len` field is not present, the server should send image data to the client until such point as all of the relevant data has been sent, a quality limit is reached (see C.6.2), or the response is interrupted by the arrival of a new request that does not include a `wait` request field with a value of "yes" (see C.7.2). The client should use `len=0` if it requires response headers only and no entity body (see Annex F). Nevertheless, transport protocols that require framing of responses require an EOR message (see Annex G).
+
+### C.6.2 Quality (quality)
+
+```
+quality = "quality" "=" (1*2DIGIT / "100") ; 0 to 100
+```
+
+This field can be used to limit data transmission to a quality level (between 0 for lowest quality and 100 for highest quality) associated with the image. Quality limits are difficult to formulate in a reliable manner, and the server may ignore this request by responding with a value "-1" (see D.2.16). Nevertheless, it is useful to allow the client to provide some indication of the maximum image quality that might be of interest. The quality factor might attempt to approximate the ad hoc Quality commonly used to control JPEG compression. The client should expect that the returned data size is monotonically non-decreasing with increasing quality, i.e., increasing the quality value generally corresponds to increasing the returned data size.
+
+If a server supports this request and two different clients make identical requests to the same target having the same quality value, e.g., "quality=80", the server should have a consistent implementation policy in returning data from data-bins.
+
+## C.7 Server control request fields
+
+### C.7.1 Alignment (align)
+
+```
+align = "align" "=" ("yes" / "no")
+```
+
+This field specifies whether the server response data shall be aligned on "natural boundaries". The default value is "no". If the server supports aligned responses and the value is "yes", any JPT-stream or JPP-stream message delivered in response to this request which crosses any natural boundary shall terminate at any subsequent natural boundary. Servers that do not support data alignment but receive an alignment request with the value "yes" shall indicate this by the Alignment Response defined in D.2.24.
+
+The natural boundaries for each data-bin type are listed in Table C.3. A message is said to cross a natural boundary if it includes the last byte prior to the boundary and the first byte after the boundary.
+
+NOTE – For example, a precinct data-bin crosses a natural boundary if it includes the last byte of one packet and the first byte of the next packet. Note carefully that aligned response messages are not actually required to terminate at a natural boundary unless they cross a boundary. This means, for example, that the response may include partial packets from precincts, which might be necessary if a prevailing byte limit prevents the delivery of complete packets.
+
+**Table C.3 – Alignment boundaries based on bin type**
+
+| Bin type             | Natural boundary                                                          |
+|----------------------|---------------------------------------------------------------------------|
+| Precinct data-bin    | End of a packet (one boundary for each quality layer)                     |
+| Tile data-bin        | End of a tile-part (one boundary for each tile-part)                      |
+| Tile header data-bin | End of the bin (only one boundary)                                        |
+| Main header data-bin | End of the bin (only one boundary)                                        |
+| Metadata-bin         | End of a box at the top level of the data-bin (one boundary for each box) |
+
+### **C.7.2 Wait (wait)**
+
+```
+wait = "wait" "=" ("yes" / "no")
+```
+
+This field is used to indicate whether the server shall complete a response to the previous request. If the value of the field is "yes", the server shall completely respond to the previous request on the same channel resource specified through the channel ID field before starting to respond to this request.
+
+If the value of this field is "no", the server may gracefully terminate the processing of any previous request on the same channel resource (specified through the Channel ID field) prior to completion and may start to respond to this new request. In this context, "graceful termination" implies that the server shall at least complete the current message.
+
+The default value of this field is "no".
+
+The combination of "wait = yes" with "cclose=\*" is not recommended. If this situation is encountered, the server can decide which of the two takes priority.
+
+### **C.7.3 Image Return Type (type)**
+
+```
+type = "type" "=" 1#image-return-type
+image-return-type = media-type / reserved-image-return-type
+media-type = TOKEN "/" TOKEN *( ";" parameter )
+reserved-image-return-type = TOKEN *( ";" parameter )
+parameter = attribute "=" value
+attribute = TOKEN
+value = TOKEN
+```
+
+This field is used to indicate the type (or types) of the requested response data. A server unwilling to provide any of the requested return types shall issue an error response.
+
+The value of the Image Return Type request field shall be either a media type (defined in RFC 2046) or one of the reserved image return types defined in Table C.4.
+
+**Table C.4 – Valid image return types**
+
+| Type         | Interpretation                                                                                                                                                                                                                 |
+|--------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| "jpp-stream" | A JPP-stream as defined in Annex A. "jpp-stream" can optionally be followed by ";ptype=ext", in which case the requested return type is one in which all precinct data-bin message headers have the extended form. (see A.2.2) |
+| "jpt-stream" | A JPT-stream as defined in Annex A. "jpt-stream" can optionally be followed by ";ttype=ext", in which case the requested return type is one in which all tile data-bin message headers have the extended form. (see A.2.2)     |
+| "raw"        | The client is requesting the entire sequence of bytes in the logical target to be delivered unchanged.                                                                                                                         |
+| Other values | Reserved for ISO use                                                                                                                                                                                                           |
+
+If the `type` request field is omitted, the return type should be determined by another means.
+
+In a session, i.e., one whose requests involve a Channel ID request field, the value of the return parameter shall be maintained in successive responses for image data or metadata requests which correspond to the same logical target.
+
+NOTE – Other image media types (e.g., jp2, jph, jpeg, tiff, png), if available, can be provided by a server as a transcoding service with JPIP functionality.
+
+For the raw codestream return type, the response data should consist of the requested entity in full. Therefore, many of the other possible client request fields would have no meaning and would be ignored by a server.
+
+### C.7.4 Delivery Rate (drate)
+
+```
+drate = "drate" "=" rate-factor
+rate-factor = UFLOAT
+```
+
+This field is used to specify the delivery rate of various codestreams. If this field is supplied, the server shall deliver data belonging to the various codestreams in the view-window following a temporally sequenced schedule. The codestreams which belong to the view-window are all those identified via the Codestream request field and the Codestream Context request field, possibly subsampled in accordance with the Sampling Rate request field.
+
+In order to provide meaning to this request field, timing information shall be associated with the various codestreams in the view-window. If the codestreams belong to an MJ2 or J2KS file, the timing information is provided by that file. The MJ2 or J2KS file provides a mapping between each codestream and a nominal playback time, which is identified here as the "source time."
+
+If the codestreams do not have source timing information, but the Sampling Rate request field is present, the server shall assume that codestreams in the view-window have source times which are separated by the reciprocal of the value in the Sampling Rate request field.
+
+If the codestreams do not have source timing information, and the Sampling Rate request field is not present, the server shall assume that the codestreams in the view-window have source times which are separated by exactly one second.
+
+The Delivery Rate request field provides a scaling factor between delivery and source rates. If the rate-factor is given as 1, the server should attempt to deliver codestreams to the client at the rate suggested by their source times, noting that these source times might not necessarily be regular. More generally, if the rate-factor is  $F$ , the server should attempt to deliver codestreams to the client at a rate which is  $F$  times faster than that suggested by their source times.
+
+If the server is unable to deliver all relevant data for each codestream at the requested rate (e.g., due to bandwidth constraints), it should deliver only part of the data for each codestream, so as to avoid violating the requested delivery rate. The portion of each codestream's data which is not delivered might depend upon the *view-window-pref* value supplied in a Client Preferences request field (see C.10.2). If the preference is "progressive" or no such preference is identified, the server should attempt to deliver a uniform, maximum image quality over the view-window, subject to the delivery rate constraint. If a *view-window-pref* value of "fullwindow" has been supplied, the server might truncate the representation associated with each codestream in some other way. In any event, the behaviour should be similar to that which would have resulted from the client issuing a succession of requests for each of the relevant codestreams in turn, at the delivery rate.
+
+If the server is able to deliver all relevant data for each codestream, at the requested rate, it should idle the connection as required to ensure that the delivery rate is not exceeded.
+
+If this field is not supplied and if a *view-window-pref* value of "fullwindow" has not been specified, the server should attempt to sequence the relevant data in such a way as to progressively increment the quality of all codestreams uniformly.
+
+### C.7.5 Send To (Sendto)
+
+```
+Sendto = "sendto" "=" host ":" port ";" mbw ";" bpc
+host = token
+port = UINT
+bpc = UINT
+```
+
+If this request field is present, the server is requested to deliver response data for this request as UDP datagrams to the supplied *host* (name or IP literal), using the supplied *port* number, with a maximum delivery bandwidth of *mbw*, and a maximum of *bpc* bytes in each data chunk, including the 8-byte chunk header. The bandwidth can be expressed in terms of bits/second, kilobits/second, megabits/second, gigabits/second or terabits/second; for a definition of "mbw", see 10.2.4. The *bpc* value shall be no smaller than 32 and no larger than 4096.
+
+This request field shall only be used to direct the response data associated with an established "http-udp" transport. Servers shall ignore the request field if the transport type associated with the request is not "http-udp". Otherwise, response data is framed into chunks and delivered via UDP datagrams in the manner described in Annex K. Moreover, in this case, the client shall not send acknowledgement datagrams in response to these delivered chunks, nor should the server expect them.
+
+The effect of this request field is non-persistent; it applies only to the response data associated with the request in which it is found.
+
+NOTE 1 – A request is associated with the "http-udp" transport type in one of two possible circumstances: a) the request contains a "new-channel" request field and the server grants the request with a new channel that uses the "http-udp" transport, as indicated by the `JPIP-cnew` response header; or b) the request specifies a channel-id that has been issued for a channel using the "http-udp" transport and no new JPIP channel is issued by the server in response to this request.
+
+NOTE 2 – Because response data delivered to the address specified by a `Sendto` request field is not explicitly acknowledged, clients can benefit from using the `abandon` and `barrier` request fields, which can be used to effect reliable communications. Also, because the server receives no acknowledgement information from which to estimate channel conditions, such as bandwidth and loss probability, it is the client's responsibility to perform whatever estimation might be necessary and supply an appropriate delivery bandwidth and chunk size.
+
+### C.7.6 Abandon (`abandon`)
+
+```
+abandon = "abandon" "=" 1#chunk-range
+
+chunk-range = chunk-qid ":" chunk-seq-range
+
+chunk-qid = UINT
+
+chunk-seq-range = UINT-RANGE
+```
+
+This request field allows the client to explicitly inform the server about the absence of one or more data chunks that might have been sent in response to previous requests. Each occurrence of `chunk-range` informs the server of one or more data chunks that should be considered not to have arrived at the client. The server shall not consider any of the data associated with JPIP messages contained within these identified data chunks received or cached by the client, for the purpose of responding to this request or any subsequent request on this or any other JPIP channel, except in the event that the server receives, or has received, explicit acknowledgement of the arrival of these data chunks via acknowledgement datagrams.
+
+If the request does not specify a channel-id which has been issued for a channel using the HTTP-UDP transport, the client shall not include any `Abandon` request field and the server shall ignore any such request field that it encounters.
+
+NOTE 1 – The `Abandon` request field can be used regardless of whether the `Sendto` request field is present in the same request.
+
+The `chunk-range` values identify data chunks via the 16 low-order bits of the request ID and the chunk sequence number; both of these values are found in the relevant chunk headers, as described in Annex K. The request ID component is identified by `chunk-qid` and matches the contents of the Request ID field in the chunk header the client wants to negatively acknowledge; no `chunk-range` shall have a `chunk-qid` value outside the range 0 to 65535.
+
+The `Abandon` request field only applies to data chunks which have been transmitted or would be transmitted in response to previous requests within the same channel. To avoid ambiguity, servers shall ignore any `Abandon` request field which is part of the first request in a new JPIP channel – i.e., the request in which the channel's New Channel request field appears. Also, the `Abandon` request field does not apply to data chunks belonging to requests that have been excluded by means of a `Barrier` request field that appeared in a previous request within the channel.
+
+NOTE 2 – It is possible that some of the data chunks affected by an `Abandon` request field have not been transmitted by the server by the time the request arrives. In this case, the server would typically abandon these data chunks immediately, without even transmitting them a first time. If this behaviour is not desired by the client, the client can avoid abandoning data chunks before at least one later data chunk within the same request or a data chunk from a later request have been received.
+
+NOTE 3 – As explained in Annex B, this Recommendation | International Standard does not require the server to maintain a complete log of data which it has sent in response to client requests; nor does it require the server to exclude such data from its response to future requests. This means that a server can, at its discretion, choose to erase any log entry describing the transmitted chunks at any point. However, if the server does maintain a log of what has been sent to the client, for the purpose of avoiding redundant transmission in the future, it might need to keep track of the contents of data chunks for which it has not yet received acknowledgement information via acknowledgement datagrams or `Abandon` request fields, so that it can correctly respond to `Abandon` requests in the future. A server can choose to erase parts of its log at any time so as to reduce the burden of keeping track of unacknowledged data chunks. Alternatively, the client can use `Barrier` request fields to inform the server that it will never `Abandon` data chunks sent in response to a certain range of requests, so that the server need not keep track of unacknowledged data chunks belonging to that range.
+
+### C.7.7 Barrier (`barrier`)
+
+```
+barrier = "barrier" "=" barrier-qid
+
+barrier-qid = UINT
+```
+
+This request field is provided to enable clients to inform servers of the requests for which response data chunks will not be abandoned via any subsequent request. The effect of `Barrier` request fields persists within the associated JPIP channel. Specifically, the effect of any `Abandon` request field in any subsequent request is limited to data chunks whose associated request has a request-id `Q` that is strictly greater than `Qb`, where `Qb` is the maximum of all `barrier-qid` values specified in this or any preceding request within the same JPIP channel.
+
+If the request does not specify a channel-id that has been issued for a channel using the "http-udp" transport, the client shall not include any Abandon request field and the server shall ignore any such request field that it encounters.
+
+NOTE 1 – The Barrier request field only affects the interpretation of Abandon request fields found in subsequent requests. Thus, for example, "barrier=3&abandon=3:4-7" means that the client is abandoning data chunks 4 to 7 from the request with request-id 3, but it will not abandon any data chunks from that request in the future.
+
+NOTE 2 – The chunk-qid values supplied via a chunk-range in an Abandon request match any request whose request-id has the same least significant 16 bits as chunk-qid. On the other hand, the barrier-qid value supplies a full request-id, not just the least significant 16 bits.
+
+### C.7.8 Timed wait (twait)
+
+```
+twait = "twait" "=" max-wait-usecs
+max-wait-usecs = UINT
+```
+
+This request field allows the client to suggest the latest point at which it would like the server to start responding to the current request, pre-empting the previous incomplete request, if any, within the same JPIP channel.
+
+If there is no previous request within the JPIP channel this request field shall be disregarded by the server and the request shall be considered not to contain `twait` for the purpose of the ensuing description. If the previous request within the JPIP channel does not contain the `twait` request field, the latest pre-empt time is obtained by adding `max-wait-usecs` microseconds to the time at which the server began to serve that previous request. If one or more immediately preceding requests within the JPIP channel contain the `twait` request field, the latest pre-empt time is obtained by adding the `max-wait-usecs` values of all such requests, as a number of microseconds, to the time at which the server began to serve the most recent request within the channel that did not contain the `twait` request field.
+
+Clients shall not issue requests that contain both the `twait` and `wait` request fields.
+
+NOTE – In applications where animation is involved, clients might find it useful to send a succession of timed-wait requests, so that the server is able to optimize the actual service times to devote to each outstanding request, subject to their respective latest pre-empt times.
+
+## C.8 Cache management request fields
+
+### C.8.1 Model (model)
+
+#### C.8.1.1 General
+
+```
+model = "model" "=" 1#model-item
+model-item = [codestream-qualifier ","] model-element
+model-element = ["-"] bin-descriptor
+bin-descriptor = explicit-bin-descriptor ; C.8.1.2
+                  / implicit-bin-descriptor ; C.8.1.3
+codestream-qualifier = "[" 1$(codestream-range) "]"
+codestream-range = first-codestream-id ["-" [last-codestream-id]]
+first-codestream-id = UINT
+last-codestream-id = UINT
+```
+
+This field can be used in session-based or stateless requests. A session-based request is any request that includes a Channel-ID field, since channels are associated with a session managed by the server. The "model" field contains one or more bin-descriptors, each of which identifies a data-bin, or a range of data-bins, about which cache information is being signalled. For requests within a session, this cache information serves to update the server's model of the client's cache. There is only one cache model for each logical target associated with the session. For a stateless request, the server's model of the client's cache is empty at the start of the request, but is updated by the "model" field (if one exists) before the server formulates its response. All cache model information is discarded at the conclusion of the processing of a stateless request by the server.
+
+Two forms are provided for bin-descriptor values to facilitate the efficient exchange of cache model information. These are termed the "explicit" and the "implicit" forms and are described in the following subclause. Clients can issue requests using either form and can mix the two forms of bin-descriptor within a single "model" request field if desired.
+
+If a bin-descriptor is preceded by a "-" symbol, it is said to be subtractive. Otherwise, it is said to be additive. A subtractive bin-descriptor informs the server that the relevant data should be removed from the server's model of the client cache.
+
+Removal of elements from the cache model means that the server shall not assume that the client already has these elements. Bin-descriptor values are processed in order.
+
+An additive bin-descriptor (one which is not preceded by the "-" symbol) informs the server of data which the client already has in its cache. The server can add this information to its cache model and may assume that the client already has the indicated data.
+
+The "model" field may reference data-bins that are not relevant to the view-window of interest identified by other request fields (Frame Size, Region Size, Offset, etc.). Where this happens, the cache model manipulation might not affect the response to the current request, but might nevertheless affect the response to future requests (unless the request is stateless).
+
+Wherever the list of model-items includes a codestream-qualifier, all subsequent model-elements shall be added or subtracted (as appropriate) from all codestreams whose identifiers are listed by the codestream-qualifier. Codestream-qualifiers can be interspersed throughout the list to progressively alter the collection of codestreams that are to be affected by the ensuing model-elements. Any model-element that is not preceded by a codestream-qualifier applies to the first codestream requested via a Codestream request field. If no Codestream request field is present, model-element values which are not preceded by a codestream-qualifier shall refer to codestream 0, regardless of whether or not a Codestream Context request field is included. If the last-codestream-id is not present, but the qualifier hyphen is, then this shall mean the first-codestream-id and all subsequent codestreams are included.
+
+Requests within a session shall not include any codestream-qualifier which references more than a single codestream.
+
+NOTE 1 – It is beneficial for the server to exploit additive cache model manipulation statements, but is free to disregard some or all of them at the possible expense of transport efficiency. It is therefore beneficial for clients to be aware that servers might be quite likely to disregard additive cache model manipulation statements that refer to data-bins belonging to codestreams that will not be serviced by the current request. To remove such uncertainties where multiple codestreams are involved, the "mset" request field can be used to determine the set of codestreams which are being modelled.
+
+NOTE 2 – Manipulation of a session-based server's cache model generally affects the response to both the current request and any future requests. Moreover, all channels within a session that are associated with a single logical target share the same cache model and so "model" fields in requests that arrive using one channel (Channel ID field) might affect the response to requests that arrive using a different channel. It is worth noting that requests which use different JPIP channels (different Channel ID values) might arrive asynchronously at the server, if separate TCP channels are used to transport the request either directly from the client or indirectly at an intermediate proxy. For this reason, it is beneficial for clients to take whatever action is necessary to ensure that their cache model manipulation instructions remain meaningful in light of these considerations.
+
+#### C.8.1.2 Explicit form
+
+```
+explicit-bin-descriptor = explicit-bin
+                        [ ":" (number-of-bytes / number-of-layers) ]
+
+explicit-bin = codestream-main-header-bin
+              / meta-bin
+              / tile-bin
+              / tile-header-bin
+              / precinct-bin
+
+number-of-bytes = UINT
+
+number-of-layers = %x4c UINT ; "L"
+
+codestream-main-header-bin = %x48 %x6d ; "Hm"
+
+meta-bin = %x4d bin-uid ; "M"
+
+tile-bin = %x54 bin-uid ; "T"
+
+tile-header-bin = %x48 bin-uid ; "H"
+
+precinct-bin = %x50 bin-uid ; "P"
+
+bin-uid = UINT / "*"
+
+```
+
+The bin-descriptor values that explicitly refer to data-bins are of the following types: M (metadata-bins), Hm (main header data-bins), H (tile header data-bins), P (precinct data-bins) or T (tile data-bins). Explicit bin-descriptors identify the relevant data-bin (or data-bins) within the relevant codestreams, using either a unique integer-valued identifier, or a wildcard character, "\*". The only exception to this is the codestream main header data-bin, whose bin-descriptor is "Hm". For all other data-bin classes, the unique identifier is identical to the value communicated by the in-class identifier in JPP-stream and/or JPT-stream message headers (see Annex A).
+
+The wildcard character, "\*", shall be used only in stateless requests. Where it is used, the bin-descriptor refers simultaneously to all data-bins of the relevant class (metadata, precinct, tile header or tile), relevant to the view-window.
+
+Each bin-descriptor can be qualified by a number of bytes. An additive bin-descriptor which is qualified by the number of bytes,  $B$ , indicates that the client already has at least the first  $B$  bytes of the indicated data-bin in its cache; the server can add the first  $B$  bytes of the data-bin to its cache model. A subtractive bin-descriptor that is qualified by the number of bytes,  $B$ , indicates that the client has at most the first  $B$  bytes of the indicated data-bin; the server shall remove any bytes following the first  $B$  bytes of the data-bin from its cache model.
+
+EXAMPLE 1: A qualified subtractor bin-descriptor such as "-P23:10" means that the server should remove all but the first 10 bytes of precinct data-bin 23 from its cache model. This does not imply that the client has the first 10 bytes of precinct data-bin 23 in its cache and the server should not assume this by adding these bytes to its cache model if they were not already present.
+
+Precinct bin-descriptors can alternatively be qualified by a number of layers. An additive bin-descriptor that is qualified by the number of layers,  $L$ , indicates that the client already has at least the first  $L$  layers (first  $L$  packets) of the indicated precinct; the server can add the bytes corresponding to these layers to its cache model. A subtractive precinct bin-descriptor that is qualified by the number of layers,  $L$ , indicates that the client has at most the first  $L$  layers ( $L$  packets) of the indicated precinct; the server shall remove the bytes corresponding to any subsequent layers of that precinct from its cache-model.
+
+A bin-descriptor with no number-of-bytes or number-of-layers qualifier means the entire explicit data-bin.
+
+EXAMPLE 2: "model=M0,Hm,H7:20,P3" means that the client has at least all of metadata-bin 0, all of the main codestream header, the first 20 bytes of tile header 7, and all of precinct 3 in its cache.
+
+EXAMPLE 3: "model=P3:256,P5:L2,-P6:20" means that the client has at least the first 256 bytes of precinct 3 and the first two layers (packets) of precinct 5, but (at most) it does not have anything beyond the 20-th byte of precinct 6 (it might not have the first 20 bytes either).
+
+EXAMPLE 4: "model=M\*,-M5,-H\*,-P\*:L3" means that the client has (or is prepared to let the server believe it has) all metadata-bins except metadata-bin 5, no tile header data-bins which are relevant to the view-window and at most the first 3 layers of any precinct which is relevant to the view-window. The wildcards used here are permissible only when the "model" statement appears in a stateless request.
+
+EXAMPLE 5: "model=[30-200],Hm,H\*,M\*,P0,[0-29],-Hm,-H\*,-M\*,-P\*" means that the client has all headers and metadata, plus precinct data-bin 0 from codestreams 30 through 200 inclusive, but that it has removed all header, metadata and precinct data-bins from the first 30 codestreams.
+
+#### C.8.1.3 Implicit form
+
+```
+implicit-bin-descriptor = 1*implicit-bin [":" number-of-layers]
+implicit-bin      = implicit-bin-prefix (data-uid / index-range-spec)
+implicit-bin-prefix = %x74      ; t -- tile
+                  / %x63      ; c -- component
+                  / %x72      ; r -- resolution level
+                  / %x70      ; p -- position
+
+index-range-spec = first-index-pos "-" last-index-pos
+first-index-pos  = UINT
+last-index-pos   = UINT
+data-uid         = UINT / "*"
+
+```
+
+Implicit bin-descriptors are only applicable to JPP-stream requests. The bin-descriptor values that implicitly refer to data-bins are of the following types: t (tile to which the precinct belongs), c (image component to which the precinct belongs), r (resolution level of the tile-component to which the precinct belongs) or p (position of the precinct within its tile-component-resolution). Implicit bin-descriptors are used to identify precinct data-bins via the indices. All indices shall start from 0. A resolution level index of 0,  $r0$ , refers to the lowest resolution level (LL sub-band) of the tile-component. Position indices,  $p$ , run from left to right and top to bottom of the tile-component-resolution progression, in scan-line fashion, as described in Rec. ITU-T T.800 | ISO/IEC 15444-1.
+
+In stateless requests, any or all of the tile, component, resolution level or position implicit-bin specifier can be replaced with the index range or the wildcard character, "\*". In either case, the bin-descriptor is expanded to include all values of the index range relevant to the view-window. Neither of these options shall be used for requests within a session.
+
+In stateless requests, any or all of the tile, component, resolution level or position indices can also be replaced with a single range of indices. The first-index-pos value in an index-range-spec gives the first index in a range. The last-index-pos value gives the last index in the range and shall be greater than or equal to the value of the first-index-pos. Both indices specified are inclusive. The last-index-pos shall not be omitted. If a range of tile indices ("t") is given, the range
+
+refers to a rectangular array of tiles whose upper left-hand corner has the first-index-pos value and whose lower right-hand corner has the last-index-pos value. Similarly, if a range of position indices ("p") is given, the range refers to a rectangular array of precinct positions whose upper left and lower right corners are given by the first-index-pos and last-index-pos values, respectively. As for wildcards, ranges shall not be used in requests within a session.
+
+Implicit precinct bin-descriptors can be qualified by a number of layers, for which the syntax and interpretation are identical to those of layer qualified explicit precinct bin-descriptors, described previously.
+
+EXAMPLE 1: "model=t0c2r3p4:L5" indicates that the client has the first 5 packets of the fifth precinct in sequence, of the fourth resolution level, of the third component, of tile 0.
+
+EXAMPLE 2: "model=t10r0,t\*r1:L4" means that the client has all layers of the tile index 10 at resolution level 0, and the first 4 layers of all tiles relevant to view-window at resolution level 1. The wildcard is appropriate only for stateless requests.
+
+EXAMPLE 3: "model=t0-10:L2" indicates that the client has the first 2 layers from tiles 0 to 10. The range is appropriate only for stateless requests.
+
+EXAMPLE 4: "model=t\*r0-2:L4" indicates that the client has the first 4 layers from resolution levels 0 to 2 of all the tiles relevant to the view-window. The wildcard and the range are appropriate only for stateless requests.
+
+### C.8.2 Summary of cache descriptor options (informative)
+
+See Table C.5.
+
+Table C.5 – Cache descriptor option summary
+
+| Form type     | Wildcard  |               | Index-range                | number-of-layers<br>(e.g., ":L3") | number-of-bytes<br>(e.g., ":256") |
+|---------------|-----------|---------------|----------------------------|-----------------------------------|-----------------------------------|
+|               | stateless | session-based |                            |                                   |                                   |
+| Explicit form | Allowed   | Not allowed   | Not allowed                | Allowed                           | Allowed                           |
+| Implicit form | Allowed   | Not allowed   | Allowed only for stateless | Allowed                           | Not allowed                       |
+
+### C.8.3 Tile-part model involving JPT-streams (tpmodel)
+
+```
+tpmodel = "tpmodel" "=" 1#tpmodel-item
+tpmodel-item = [codestream-qualifier "," ] tpmodel-element
+tpmodel-element = ["-"] tp-descriptor
+tp-descriptor = tp-range / tp-number
+tp-range = tp-number "-" tp-number
+tp-number = tile-number "." part-number
+tile-number = UINT
+part-number = UINT
+```
+
+This field can be used to indicate specific tile-parts that the client would like to add to or subtract from the server's cache model. Like the "model" field, it may be used in both session-based and stateless requests. In the case of stateless requests, the cache model is empty at the start of the request and does not persist between requests, but it still provides a useful mechanism for identifying the image elements which are already in the client's cache.
+
+If a tile-part descriptor is preceded by a "-" character, it is said to be subtractive. Otherwise it is additive. An additive tile-part descriptor indicates that the client already has the indicated tile-part or range of tile-parts in its cache; the server can add these elements to its cache-model. A subtractive tile-part descriptor indicates that the client does not have the indicated tile-part or range of tile-parts in its cache; the server shall remove these elements from its cache-model.
+
+The first value in the tile-part number is the tile index (starting from 0); the second value is the part number (starting from 0) within the tile. A tp-range is considered to independently contain tiles from the first tile number to the second tile number and tile-parts from the first tile-part number to the second tile-part number. Thus 4.0-5.1 includes tile-parts 4.0, 4.1, 5.0, and 5.1, but not 4.2 or 5.2.
+
+The "tpmodel" and "model" request fields may both appear within a single request. In this case, however, the server shall reflect the effects of the "model" field on its cache model before processing the "tpmodel" field.
+
+Codestream-qualifier values can be interspersed amongst the list of tpmodel-elements in order to alter the collection of codestreams to which the ensuing tpmodel-elements apply, following exactly the same principles as for the "model" request field.
+
+Unlike the "model" request field, ranges of tile-parts and ranges of codestreams (in codestream-qualifiers) are both permitted within the "tpmodel" request field, regardless of whether it appears within a session-based or a stateless request.
+
+EXAMPLE 1: "tpmodel=4.0,4.1,5.0-6.2" indicates that the client already has the first two tile-parts of tile 4, and the first 3 tile-parts of tiles 5 and 6 in its cache.
+
+EXAMPLE 2: "tpmodel=-4.0-6.254" indicates that the client has no tile-parts from tiles 4, 5 or 6 in its cache.
+
+EXAMPLE 3: "tpmodel=3.0,[131-133],4.0,[100],-0.0-65534.254" indicates that the client has tile-part 0 of tile 3 from codestream 0 referenced in the request, plus tile-part 0 of tile 4 from each of codestreams 131 through 133 inclusive, and that it is deleting all tile-parts from its cache of codestream 100.
+
+### C.8.4 Need for stateless requests (need)
+
+```
+need = "need" "=" 1#need-item
+
+need-item = [codestream-qualifier "," ] bin-descriptor
+```
+
+This field shall only appear in stateless requests, i.e., those which do not include a Channel ID request field. It has the same syntax as the model request field, except that bin-descriptors shall not be preceded by a "-" symbol. The "need" request field shall not appear within the same request as a "model" or "tpmodel" request field.
+
+The "need" request field indicates the set of data-bins (or data-bin suffices) which are of potential interest to the client. The server need not send information that is not of potential interest. Regardless of how large the set of potentially interesting data-bins might be, the server should only send information which is relevant to the view-window request fields or the metadata request field.
+
+The effect of the "need" field on the server's request can be explained using the concept of a temporary cache model. The temporary cache model is initialized (empty) immediately before the request is processed and discarded after the response is generated. If a "need" field appears in the request, all possible data-bins are added into the cache model, after which all elements referenced by the bin-descriptors in the "need" field are removed from the cache model. The server then processes the requested view-window, using this cache model to determine the elements that need not be sent to the client.
+
+Codestream-qualifiers can be interspersed amongst the list of bin-descriptors in order to alter the collection of codestreams to which the ensuing bin-descriptors apply, following exactly the same principles as for the "model" and "tpmodel" request fields.
+
+EXAMPLE 1: "need=M1,H0:20,P0" means that the client needs all metadata-bin 1, data from the 20-th byte of tile header data-bin 0 and all of precinct data-bin 0.
+
+EXAMPLE 2: "need=P1:256,P5:L2" means that the client needs data beyond the 256-th byte (or from byte 256) of precinct data-bin 1, and layers beyond the second layer of precinct data-bin 5.
+
+EXAMPLE 3: "need=H\*,P\*:L3" means that the client needs all tile header data-bins relevant with the view-window and layers beyond the 3rd layer of all precinct data-bins relevant with the view-window.
+
+EXAMPLE 4: "need=t10r0,t\*r1:L4" means that the client needs all layers of the tile index 10 at resolution level 0, and layers beyond the fourth layer of all tiles relevant to view-window at resolution level 1.
+
+EXAMPLE 5: "need=t\*r0-2:L4" means that the client needs all layers from layer 4 of all the precinct data-bins in resolution levels 0 to 2 (0, 1 and 2) in all the tiles and components relevant to the view-window request.
+
+EXAMPLE 6: "need=[120-131],r0,[140;143-145],r0-1" means that the client needs resolution level 0 of codestreams 120 through 131 inclusive, and resolution levels 0 and 1 of codestreams 140 and 143 through 145 inclusive.
+
+### C.8.5 Tile-part need for stateless requests (tpneed)
+
+```
+tpneed = "tpneed" "=" 1#tpneed-item
+
+tpneed-item = [codestream-qualifier "," ] tp-descriptor
+```
+
+This field shall only appear in stateless requests, i.e., those which do not include a Channel ID request field. It has the same syntax as the tpmodel request field, except that tp-descriptors shall not be preceded by a "-" symbol. The "tpneed" request field shall not appear within the same request as a "model" or "tpmodel" request field.
+
+The "tpneed" request field indicates the set of tile-parts which are of potential interest to the client. The server need not send information that is not of potential interest. Regardless of how large the set of potentially interesting tile-parts might
+
+be, the server should only send information which is relevant to the view-window request fields or the metadata request field.
+
+The effect of the "tpneed" field on the server's request can be explained using the concept of a temporary cache model. The temporary cache model is initialized (empty) immediately before the request is processed and discarded after the response is generated. If a "tpneed" field appears in the request, all possible tile-parts and data-bins are added into the cache model, after which all elements referenced by the bin-descriptors in the "need" field and all tile-parts in the "tpneed" field are removed from the cache model. The server then processes the requested view-window, using this cache model to determine the elements that need not be sent to the client.
+
+Codestream-qualifiers can be interspersed amongst the list of tile-parts in order to alter the collection of codestreams to which the ensuing tile-parts apply, following exactly the same principles as for the "model" and "tpmodel" request fields.
+
+### C.8.6 Model set for requests within a session (mset)
+
+```
+mset = "mset" "=" 1#sampled-range
+```
+
+This field serves two purposes. In the first instance, it informs the server of the set of codestreams for which the client is prepared to cache data delivered by the server. In the second instance, it provides a mechanism for the client to learn about the codestreams for which the server is prepared to model the client's cache. Specifically, if the collection of codestream indices supplied in an "mset" request differs in any way from the set of codestreams over which the server is currently prepared to offer cache modelling, the server shall provide a Model Set response header, as discussed in D.2.18.
+
+The "mset" request field's parameter string consists of a comma-separated list of ranges of codestream indices, possibly subsampled, following the conventions outlined in connection with the Codestream request field in C.4.9.
+
+In addition to codestreams mentioned in the "mset" request, the server can also provide a cache model for all codestreams associated with its response to the current request. This is the collection of codestreams identified by the client's request (see the Codestream and Codestream Context request fields in C.4.10), unless the server indicates a reduced set of codestreams via a Codestream response header (see D.2.9). If no "mset" request field is provided, the client should not assume that the server is providing a cache model for any codestreams other than those associated with its response; however, it can model other codestreams. If an "mset" request field is given, the server shall discard any cache model information it has for all codestreams other than those mentioned either in the "mset" request, or in the set of codestreams associated with its response data. Moreover, the effects of any cache model manipulation via "model" or "tpmodel" request fields shall be restricted to just these codestreams.
+
+The server can, at its discretion, reduce the number of codestreams in the "mset", in which case, it shall supply a "mset" response header identifying the actual set of codestreams which are being modelled; moreover, this set of modelled codestreams shall at least include all codestreams associated with the server's response data (those requested by the client's request, or identified by the server's Codestream response header, if any). In this case, these statements apply to those codestreams contained in "mset" identified by the server. The server shall not identify a larger set of codestreams than those mentioned in the client's "mset" request, combined with those codestreams which are associated with the server's response data.
+
+NOTE – The server can change its "mset" from request to request, so clients which need to keep track of and/or tightly constrain the server's "mset" might choose to include an "mset" request field with every request.
+
+## C.9 Upload request parameters
+
+### C.9.1 Upload (upload)
+
+```
+upload = "upload" "=" upload-type
+upload-type = image-return-type ; C.7.3
+```
+
+This field specifies that the client is uploading new image or metadata to the server. The value of `upload-type` can be any of the valid `image-return-type` values that could be used with the type request field. See Annex E for information on uploading data.
+
+## C.10 Client capability and preference request fields
+
+### C.10.1 Client capability (cap)
+
+```
+cap = "cap" "=" 1#capability-group
+capability-group = processing-capability
+                  / depth-capability
+                  / config-capability
+processing-capability = compatibility-capability
+```
+
+```
+
+/ vendor-capability
+compatibility-capability = "cc." compatibility-code
+vendor-capability = "vc." vendor-code [":" vendor-value]
+vendor-code = 1*(LOWER / DIGIT / "." / "-")
+vendor-value = TOKEN
+depth-capability = "depth:" UINT
+config-capability = "config:" UINT
+
+```
+
+This field specifies the capabilities of the client. For session-based requests (those which include a Channel ID request field), any capability fields transmitted by the client shall affect only the channel associated with the request, and shall be considered persistent. Capabilities need not be retransmitted by the client for subsequent requests on the same channel.
+
+When a new channel is created from an existing channel, its client capabilities are inherited. For stateless requests, and for requests issued within a channel whose capabilities have never been specified or inherited, the client capabilities can be determined or anticipated by other means. The capabilities associated with a channel can be changed by including a Client Capabilities request field within any request.
+
+If the Client Capabilities request field identifies one or more of the `processing-capability` options, the server shall assume that the client does not have any of the other `processing-capability` options which could have been mentioned. If no `processing-capability` options are supplied in the Client Capabilities request field, the server shall continue to use whatever previous knowledge it had concerning processing capabilities. The `processing-capability` options defined by this Recommendation | International Standard are described in Table C.6.
+
+Table C.6 – Valid capabilities of the `processing-capabilities` element
+
+| Capability                            | Meaning                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
+|---------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| <code>compatibility-capability</code> | The client supports all files that contain <code>compatibility-code</code> in the compatibility list in the File Type box. For example, to indicate that the client supports all JP2 files, the client would transmit the string "cc.jp2_" in a Capability request field. A <code>compatibility-code</code> value of "jp2c" shall be used to indicate support for raw JPEG 2000 codestreams.                                                                                                                 |
+| <code>vendor-capability</code>        | The client supports the vendor capability defined by <code>vendor-code</code> . <code>vendor-code</code> shall be a string specifying the reverse domain name of the vendor that defined the feature, followed by the vendor feature name. For example, if example.com defined a feature called "distance", then the value of <code>vendor-code</code> for this feature shall be "com.example.distance". <code>vendor-value</code> specifies an optional value, as defined by the particular vendor feature. |
+
+If a `depth-capability` parameter is supplied, it indicates the maximum sample bit depth (precision) at which the client is able to exploit decompressed imagery. If the client supports different bit depths for different image components, this field shall specify the bit depth of the component for which the client has the greatest bit depth capability. As an example, if a client supports 12 bits for luminance and 8 bits for chrominance, the value of `depth-capability` shall be 12.
+
+NOTE – Clients having the capability to handle only *N* bits per sample will still generally be able to handle codestreams whose SIZ marker indicates a bit depth much larger than *N*. However, this flag can be used by the server to determine an appropriate manner in which to deliver the requested image data.
+
+If a `config-capability` parameter is supplied, it shall be in the range 0 to 255, representing an 8-bit word whose individual bits are interpreted as configuration flags. The interpretation of the configuration flags is provided in Table C.7.
+
+Table C.7 – Valid values of the `config-capability` parameter
+
+| Value     | Meaning                                                                                                                                |
+|-----------|----------------------------------------------------------------------------------------------------------------------------------------|
+| 1xxx yyyy | The client is capable of processing colour image data.                                                                                 |
+| 0xxx yyyy | The client is not capable of processing colour image data and desires the server to transmit any requested image regions as greyscale. |
+| x1xx yyyy | The client has a pointing device for end-user interaction                                                                              |
+| x0xx yyyy | The client does not have a pointing device for end-user interaction                                                                    |
+| xx1x yyyy | The client has a keyboard for end-user interaction                                                                                     |
+| xx0x yyyy | The client does not have a keyboard for end-user interaction                                                                           |
+
+**Table C.7 – Valid values of the config-capability parameter**
+
+| Value        | Meaning                                            |
+|--------------|----------------------------------------------------|
+| xxx1 yyyy    | The client has sound output capabilities           |
+| xxx0 yyyy    | The client does not have sound output capabilities |
+| Other values | Reserved for ISO use                               |
+
+A bit value of "x" in Table C.7 indicates that the specified value includes cases where that bit is set to either "1" or "0". Bits indicated as "y" are unused by this Recommendation | International Standard and shall be set to 0 by clients and ignored by servers.
+
+### C.10.2 Client preferences (pref)
+
+#### C.10.2.1 General
+
+```
+
+pref = "pref" "=" 1#(related-pref-set ["/r"])
+
+related-pref-set = view-window-pref           ; C.10.2.2
+                  / colour-meth-pref           ; C.10.2.3
+                  / max-bandwidth              ; C.10.2.4
+                  / bandwidth-slice            ; C.10.2.5
+                  / placeholder-pref           ; C.10.2.6
+                  / codestream-seq-pref        ; C.10.2.7
+                  / conciseness-pref           ; C.10.2.8
+                  / other
+
+other = TOKEN
+
+```
+
+This field specifies the client preferences for server behaviour. For session-based requests (those which include a Channel ID request field), any preference fields transmitted by the client shall affect only the channel associated with the request, and shall be considered persistent. Preferences need not be retransmitted by the client for subsequent requests on the same channel. Each preference shall occur no more than once in a single preference request field.
+
+When a new channel is created from an existing channel, its preferences are inherited. For stateless requests, and for requests issued within a channel whose preferences have never been specified or inherited, the client preferences can be determined or anticipated by other means. If the client desires to change its preferences, it shall send the entire affected `related-pref-set` again.
+
+Unless otherwise stated, each `related-pref-set` specifies an ordered list of individual preference tokens, from most preferred to least preferred. Where possible, the server shall respect the client preferences identified by this request field. If a `related-pref-set` is followed by the `"/r"` modifier (required), the server shall either support one of the preferences listed in the `related-pref-set`, or else it shall respond with an error. In the latter case, the server shall return an Unavailable preference response header which identifies any `related-pref-set` which had the `"/r"` modifier but could not be supported. See D.2.23 for more on the Unavailable preference response header. Supporting a preference means that the server provides functionality which affects its behaviour in accordance with the preference. This addresses the server's functionality rather than the specific parameters established by other aspects of the request.
+
+For example, consider the following Client Preferences request:
+
+```
+pref=fullwindow/r,color-ricc:2;color-icc
+```
+
+This preference request requires that the server return the complete view-window requested, regardless of how large that view-window might be (see C.10.2.2 for a discussion of the "fullwindow" preference). Since the `"/r"` modifier has been used, the server should return an error response unless it is able to support this preference. In addition, the client prefers to use Restricted ICC profiles rather than arbitrary ICC profiles, provided the Restricted ICC profile is at least of "exceptional quality." See C.10.2.3 for a discussion of colourspace preferences.
+
+A server shall ignore any value for `related-pref-set` that it does not understand and is not immediately followed by `"/r"`. If the not-understood value is followed by `"/r"`, then the server shall return the Unavailable preference response header, indicating the preference that it is not able to perform.
+
+Values of the token `other` are reserved for ISO use.
+
+#### C.10.2.2 View-window handling preferences
+
+```
+view-window-pref = "fullwindow" / "progressive"
+```
+
+This Recommendation | International Standard defines two options to specify the behaviour of the server in the event that the request cannot be serviced exactly as stated. These two options are specified in Table C.8.
+
+Table C.8 – View-window handling preferences
+
+| Option        | Meaning                                                                                                                                                                                                                                                                                                                                                                                                                         |
+|---------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| "fullwindow"  | The server shall honour the view-window request parameters but is allowed to deliver the data in arbitrary order. In the event that the server does modify view-window request parameters, the modified view window shall be such that the minimal set of data to completely satisfy the modified view-window shall be identical to the minimal set of data required to satisfy the originally requested view-window.           |
+| "progressive" | The server may modify the view-window request parameters in order to retain the progressive properties of the response data. In the event that the server does modify view-window request parameters, the modified view window shall be such that the minimal set of data to completely satisfy the modified view-window shall be a subset of the minimal set of data required to satisfy the originally requested view-window. |
+
+If neither "fullwindow" nor "progressive" is specified in the Client Preferences request field, the server shall infer that the client's preference is "progressive".
+
+NOTE – The interpretation of "progressive" delivery can be affected by the presence of a Delivery Rate request field, as explained in C.7.4. The *view-window-pref* field provides strategies for a server operating under resource constraints to satisfy a request that might otherwise exceed these resources. The "progressive" mode allows the server to shrink the source window in order to provide a more uniform progression over the view window, whereas the "fullwindow" mode allows the server to reorder data arbitrarily in order to deliver the full window.
+
+#### C.10.2.3 Colourspace method preference
+
+```
+color-meth-pref = 1$(color-meth [":" meth-limit])
+
+color-meth = "color-enum" / "color-ricc" / "color-icc" / "color-vend"
+
+meth-limit = UINT
+```
+
+This Recommendation | International Standard defines four options that specify what forms of colourspace specification data should be returned by the server. A single JPEG 2000 file can contain multiple specifications of the colourspace for a single codestream or compositing layer. This allows a file writer to provide the optimal colourspace specification while still providing interoperable solutions.
+
+However, not all readers will support all colourspace methods, and the data provided for some colourspace methods might be of significant size. In those cases, the server should only send the colourspace specification data that is desired by the client.
+
+If the Client Preferences request field does not contain any colourspace method preferences or the server does not support this field but is able to retrieve the client capabilities, then the supported colourspace methods are defined according to the information contained within the Capability field, and no preference is defined.
+
+Each colourspace method preference consists of two parts: the particular colourspace method, and an optional limit on that preference. Valid values of the colourspace method are specified in Table C.9.
+
+Table C.9 – Colourspace method client preferences
+
+| Method       | Meaning                                                                          |
+|--------------|----------------------------------------------------------------------------------|
+| "color-enum" | The client prefers colourspace specifications that use the Enumerated Method     |
+| "color-ricc" | The client prefers colourspace specifications that use the Restricted ICC Method |
+| "color-icc"  | The client prefers colourspace specifications that use the Any ICC Method        |
+| "color-vend" | The client prefers colourspace specifications that use the Vendor Method         |
+
+The optional *meth-limit* value specifies a limit on the APPROX value for that particular colourspace method. When using these preferences to select a colourspace specification, the server shall consider a colourspace method specification with an APPROX value of *meth-limit* or less as if the actual APPROX value was 1 (exact). This allows clients to specify the point at which colour fidelity is not important for a particular colourspace method, for the current application. For example, a page-layout application that is only concerned with aligning the image data with other elements on the page might not care at all about colour fidelity and set *meth-limit* to 4, meaning that the accuracy of the colourspace methods is unimportant. Another application that displays images on a low-quality screen might set *meth-limit* to 3, to indicate that as long as the colour accuracy is reasonable, it would be satisfied. The characters of the field shall be interpreted as an unsigned decimal integer. Allowed values are defined by the definition of the APPROX field in Rec. ITU-T T.801 |
+
+ISO/IEC 15444-2. If the optional `meth-limit` value is not supplied, the default value shall be the largest value defined in that Recommendation | International Standard. When selecting which Colourspace Specification box to transmit to the client, the server shall use the algorithm shown in Figure C.3.
+
+![Flowchart of the Colourspace specification box selection procedure. The process starts with 'Start' and proceeds through several decision diamonds. The first diamond asks 'Is spec[i].METH included in the client preference request?'. If 'No', it goes to 'spec[i].APPROX = 0?'. If 'Yes', it goes to 'spec[i].APPROX = 0?'. If 'No' to either, it calculates 'Lowest priority for specifications without APPROX values or preference' as priority[i] = 3000 - spec[i].PREC. If 'Yes' to 'spec[i].APPROX = 0?', it calculates 'Lower priority for specifications without APPROX values' as priority[i] = 1000 - spec[i].PREC. If 'No', it goes to 'spec[i].APPROX ≤ limit[spec[i].METH]?'. If 'Yes', it calculates 'Use modified value' as priority[i] = 257 - spec[i].PREC. If 'No', it calculates 'Use unmodified value' as priority[i] = spec[i].APPROX + 256 - spec[i].PREC. All paths lead to 'Done'.](c3254408eadbf152632a8faf16310722_img.jpg)
+
+```
+
+graph TD
+    Start([Start]) --> D1{Is spec[i].METH included  
+in the client preference  
+request?}
+    D1 -- No --> D2{spec[i].APPROX = 0?}
+    D1 -- Yes --> D3{spec[i].APPROX = 0?}
+    D2 -- Yes --> P1[Lowest priority for specifications without  
+APPROX values or preference  
+priority[i] = 3000 - spec[i].PREC]
+    D2 -- No --> P2[Low priority  
+priority[i] = 2000 - spec[i].PREC +  
+spec[i].APPROX]
+    D3 -- Yes --> P3[Lower priority for specifications  
+without APPROX values  
+priority[i] = 1000 - spec[i].PREC]
+    D3 -- No --> D4{spec[i].APPROX ≤  
+limit[spec[i].METH]?}
+    D4 -- Yes --> P4[Use modified value  
+priority[i] = 257 -  
+spec[i].PREC]
+    D4 -- No --> P5[Use unmodified value  
+priority[i] = spec[i].APPROX + 256 -  
+spec[i].PREC]
+    P1 --> Done([Done])
+    P2 --> Done
+    P3 --> Done
+    P4 --> Done
+    P5 --> Done
+  
+```
+
+Flowchart of the Colourspace specification box selection procedure. The process starts with 'Start' and proceeds through several decision diamonds. The first diamond asks 'Is spec[i].METH included in the client preference request?'. If 'No', it goes to 'spec[i].APPROX = 0?'. If 'Yes', it goes to 'spec[i].APPROX = 0?'. If 'No' to either, it calculates 'Lowest priority for specifications without APPROX values or preference' as priority[i] = 3000 - spec[i].PREC. If 'Yes' to 'spec[i].APPROX = 0?', it calculates 'Lower priority for specifications without APPROX values' as priority[i] = 1000 - spec[i].PREC. If 'No', it goes to 'spec[i].APPROX ≤ limit[spec[i].METH]?'. If 'Yes', it calculates 'Use modified value' as priority[i] = 257 - spec[i].PREC. If 'No', it calculates 'Use unmodified value' as priority[i] = spec[i].APPROX + 256 - spec[i].PREC. All paths lead to 'Done'.
+
+T.808\_FC.3
+
+**Figure C.3 – Colourspace specification box selection procedure**
+
+For each Colourspace Specification box which uses a method that is supported by the client, where:
+
+- `spec[]` is an array containing all of the Colourspace Specification boxes from the given logical target.
+- `spec[i].APPROX` is the value of the APPROX field for the *i*th Colourspace Specification box as it appears in the logical target.
+- `spec[i].METH` is the value of the METH field for the *i*th Colourspace Specification box as it appears in the logical target.
+- `spec[i].PREC` is the value of the PREC field for the *i*th Colourspace Specification box as it appears in the logical target.
+- `limit[]` is an array containing the `meth-limit` values specified in the request field, indexed by the valid values of the METH field in the Colourspace Specification box.
+- `priority[]` is an array of calculated priority values for each Colourspace Specification box in the given logical target. `priority[i]` corresponds to `spec[i]`.
+
+If the server knows that the client does not support a particular Colourspace Specification box, then the server shall ignore that box for purposes of selecting the preferred Colourspace Specification box. Once the `priority[]` values have been calculated for each supported Colourspace Specification box, the server shall select the box with the lowest priority value. In the event that multiple boxes have a priority value equal to the minimum value for this logical target, the server shall select the colourspace method using the following preference order:
+
+- 1) Enumerated method;
+- 2) Vendor method;
+
+- 3) Restricted ICC method;
+- 4) Any ICC method.
+
+Regardless of the client preferences for Colourspace Specification boxes, the server may return more Colourspace Specification boxes than the single colour box specified by this algorithm, depending upon the division of a file into metadata-bins.
+
+#### C.10.2.4 Max bandwidth
+
+```
+max-bandwidth = "mbw:" mbw
+mbw = NONZERO ["K" / "M" / "G" / "T"]
+```
+
+This preference signals the maximum rate at which the client would like to be sent data per logical target. If the `mbw` value ends in "K" the value is in kilobits/second, where 1 kilobit = 1024 bits. If the `mbw` value ends in "M" the value is in megabits/second, where 1 megabit = 1024<sup>2</sup> bits. If the `mbw` value ends in "G", the value is in gigabits/second, where 1 gigabit = 1024<sup>3</sup> bits. If the `mbw` value ends in "T", the value is in terabits/second, where 1 terabit = 1024<sup>4</sup> bits. Otherwise, the value is in bits/second. Either the capacity of the server or the network might further limit the available maximum bandwidth for the JPIP service.
+
+#### C.10.2.5 Bandwidth slice
+
+```
+bandwidth-slice = "slice:" slice
+slice = NONZERO
+```
+
+This preference can be used to identify the fraction of the available bandwidth that should be allocated to this channel. The value of `slice` shall be strictly greater than 0. The bandwidth fraction is obtained by dividing each channel's slice value by the sum of all channel slice values. If not specified, the channel's slice value defaults to 1.
+
+As an example, a low `slice` value could be used for requesting a "background" view-window, while a higher `slice` might be used for a "foreground" view-window. If the session contains channels that are associated with different logical targets, slice values affect the proportion of the available bandwidth which is assigned to these different targets (images).
+
+#### C.10.2.6 Placeholder preference
+
+```
+placeholder-pref = "meta:" placeholder-branch
+placeholder-branch = "incr" / "equiv" / "orig"
+```
+
+This preference can be used to indicate the preferred treatment of Placeholder boxes. Where Placeholder boxes appear within the metadata in a JPP-stream or JPT-stream, there can be as many as three different representations of the content of a box: the original box; a streaming equivalent box; and an incremental codestream (signalled via the index). These possibilities are explained in clauses A.3.6 and A.4. As explained in A.4, the recommended default assumption is that the client would prefer to receive the incremental codestream, if available, failing which it would prefer to receive the streaming equivalent box, if available. The client can signal an alternate preference using the mechanism described here. Valid values of the Placeholder preference are specified in Table C.10.
+
+Table C.10 – Placeholder preferences
+
+| Method  | Meaning                                                                                                                                                                                                                                 |
+|---------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| "orig"  | The client would prefer to receive the original box, if available. Failing that, the client would prefer to receive a streaming equivalent box, if available.                                                                           |
+| "equiv" | The client would prefer to receive a streaming equivalent box, if available. Failing that, the client would prefer to receive the original box, if available.                                                                           |
+| "incr"  | The client would prefer to receive the incremental codestream data-bins, if available. Failing that, the client would prefer to receive the streaming equivalent box, if available. This is the same as the recommended default policy. |
+
+It is not valid to provide more than one value for the placeholder preference.
+
+#### C.10.2.7 Codestream sequencing
+
+```
+codestream-seq-pref = "codeseq:" codestream-seq-option
+codestream-seq-option = "sequential" / "reverse-sequential" / "interleaved"
+```
+
+This preference can be used to indicate how the client desires that the server deliver multiple codestreams that have been requested within a single request. Valid values of the Codestream sequencing preference are specified in Table C.11.
+
+**Table C.11 – Codestream sequencing preferences**
+
+| Method               | Meaning                                                                                                                                                                 |
+|----------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| "sequential"         | The client would prefer to receive the multiple codestreams in a frame sequential order (e.g., serve multiple frames in a Motion JPEG 2000 file in a sequential order). |
+| "reverse-sequential" | The client would prefer to receive the multiple codestreams in a frame sequential order (i.e., multiple frames in a Motion JPEG 2000 file), in the reverse order.       |
+| "interleaved"        | The client would prefer to receive the multiple codestreams in an interleaved manner (e.g., server interleaved multiple compositing layers from a JPX file).            |
+
+It is not valid to provide more than one value for the codestream sequencing preference.
+
+#### C.10.2.8 Conciseness preference
+
+```
+conciseness-pref = "loose" / "concise"
+```
+
+This preference can be used to indicate how strictly a server shall bind its response to the request made by the client, and how much excess data (i.e., data included in the response that is not required to satisfy the request) the server is allowed to include. Allowed values of the conciseness-preference are specified in Table C.12. Servers may ignore any `/r` modifier applied to this preference, and its usage is discouraged because its meaning is undefined.
+
+**Table C.12 – Conciseness preferences**
+
+| Method    | Meaning                                                                                                                 |
+|-----------|-------------------------------------------------------------------------------------------------------------------------|
+| "concise" | The server should produce the smallest response that it is capable of that satisfies the request.                       |
+| "loose"   | The server may include data which it deems appropriate to the request beyond the data necessary to satisfy the request. |
+
+To the extent that the requested view window is modified in accordance with response headers (see D.2), the above definitions are to be interpreted in terms of the modified view window.
+
+**Example:** Consider a client that performs a series of requests whose view window follows an identifiable trajectory. If the *conciseness-pref* is not set to "concise", the server may include data anticipating the future interests of the client. A client might use the *conciseness-pref* set to "concise" to discourage the server from following such a strategy.
+
+### C.10.3 Contrast sensitivity (csf)
+
+```
+csf = "csf" "=" 1#csf-sample-line
+csf-sample-line = csf-density [";" csf-angle] ";" 1$sensitivity
+csf-density = "density" ":" UFLOAT
+csf-angle = "angle" ":" UFLOAT
+sensitivity = UFLOAT
+```
+
+This field can be used to supply information concerning contrast sensitivity. While this information might represent the effects of both visual sensitivity and the modulation transfer function of a display device, it is most easily described in terms of an assumed hypothetical modulation transfer function. When reproduced at the frame size identified by the Frame Size request field, the imagery is assumed to be passed through a device whose modulation transfer function (MTF) is  $m(\omega_1, \omega_2)$ , after which it is viewed by a subject whose human visual system has a perfectly uniform contrast sensitivity function. The MTF  $m(\omega_1, \omega_2)$  is described through a collection of samples. The samples are logarithmically spaced in the radial direction, along one or more oriented axes. The server may interpolate these samples using any method it sees fit, in order to recover the MTF, which in turn can be used to adjust the order in which byte ranges of data-bins are communicated to the client through JPP-stream or JPT-stream messages.
+
+Each `csf-sample-line` represents MTF samples  $m(\omega_1, \omega_2)$  given  $\omega_1 = \pi d^n \cos \psi$ ,  $\omega_2 = \pi d^n \sin \psi$ , where  $n$  is the sample index, starting from  $n = 0$  for the first `csf-density` sample in the `csf-sample-line`,  $\psi$  is the orientation of the CSF sample line, expressed in degrees (defaults to 0 if there is no `csf-angle` value), and  $d$  is the sampling density; it shall be no larger than 1.0. The  $\omega_1$  value describes the horizontal frequency in radians, where  $\omega_1 = \pi$  is the horizontal Nyquist frequency. The  $\omega_2$  value describes the vertical frequency in radians, where  $\omega_2 = \pi$  is the vertical Nyquist frequency.
+
+The MTF sample values have meaning only in relation to each other; there is no particular interpretation for their absolute values.
+
+### **C.10.4 Handled (handled)**
+
+`handled = "handled"`
+
+If this request field is present, the server shall include a JPIP-handled response header within its response, identifying request fields which the server is prepared to handle.
+
+NOTE – The JPIP-handled response header is defined in D.2.26.
+
+# Annex D
+
+## Server response signalling
+
+(This annex forms an integral part of this Recommendation | International Standard.)
+
+## D.1 Reply syntax
+
+### D.1.1 Introduction
+
+This annex describes all possible elements in a JPIP response. Each major subclause describes the status code and its associated reason phrase, response headers and possible values for those headers, and the response data. In general, a response will consist of multiple response headers.
+
+### D.1.2 Reply structure
+
+The JPIP response consists of the following elements:
+
+- status-code;
+- reason-phrase;
+- jpip-response-header;
+- response data.
+
+The elements in the response should comply with the selected transport protocol. As an example, in HTTP, the status code and the reason phrase appear in the status line, the JPIP response headers appear in the HTTP response headers and the response data (if any) appears in the HTTP entity-body.
+
+```
+
+Status-Code = 3DIGIT
+
+Reason-Phrase = *<TEXT, excluding CR and LF>
+
+jpip-response-header =
+    / JPIP-tid                ; D.2.2
+    / JPIP-cnew                ; D.2.3
+    / JPIP-qid                 ; D.2.4
+    / JPIP-fsiz                ; D.2.5
+    / JPIP-rsiz                ; D.2.6
+    / JPIP-roff                ; D.2.7
+    / JPIP-fvsiz               ; D.2.8
+    / JPIP-rvsiz               ; D.2.9
+    / JPIP-rvoff               ; D.2.10
+    / JPIP-comps               ; D.2.11
+    / JPIP-stream              ; D.2.12
+    / JPIP-context             ; D.2.13
+    / JPIP-roi                  ; D.2.14
+    / JPIP-layers              ; D.2.15
+    / JPIP-srate               ; D.2.16
+    / JPIP-metareq             ; D.2.17
+    / JPIP-len                  ; D.2.18
+    / JPIP-quality             ; D.2.19
+    / JPIP-type                 ; D.2.20
+    / JPIP-mset                ; D.2.21
+    / JPIP-cap                  ; D.2.22
+    / JPIP-pref                 ; D.2.23
+    / JPIP-align                ; D.2.24
+    / JPIP-subtarget           ; D.2.25
+    / JPIP-handled              ; D.2.26
+
+```
+
+The reason-phrase string should ideally impart a textual explanation of the status code. The following status codes might be sufficient for JPIP applications.
+
+### D.1.3 Status codes and reason phrases
+
+#### D.1.3.1 General
+
+The status code is a 3-digit integer result from the attempt to understand and satisfy the request. A subset of the status codes and reason phrases from HTTP/1.1 are used. JPIP clients should expect the following codes. JPIP clients operating over HTTP might see other status codes as well.
+
+#### **D.1.3.2 200 (OK)**
+
+The server should use this status code if it accepts the view-window request for processing, possibly with some modifications to the requested view-window, as indicated by additional headers included in the reply.
+
+##### **D.1.3.3 202 (Accepted)**
+
+Servers should issue this status code if the view-window request was acceptable, but a subsequent view-window request was found in the queue which consequently superseded the request (because `wait=no`). When the first request becomes irrelevant before the server is able to process and commence transmission of a response, then the 202 status code shall be used. This is a common occurrence in practice, since an interactive user can change his/her region of interest multiple times before the server finishes responding to an earlier request, or before the server is prepared to interrupt ongoing processing.
+
+#### **D.1.3.4 400 (Bad request)**
+
+Servers should issue this status code if the request is incorrectly formatted, or contains an unrecognized field in the query string.
+
+##### **D.1.3.5 404 (Not found)**
+
+This status code should be issued if the server cannot locate the logical target to which the request refers, through the "target" request field, the "target-id" request field, or any other means such as the <resource> component of an HTTP GET or POST request.
+
+This status code should also be issued if a "subtarget" request field refers to a non-existent or inappropriate byte range within the requested resource.
+
+#### **D.1.3.6 415 (Unsupported media type)**
+
+This status code may be used if the single image type specified in the Image Return Type request field cannot be serviced.
+
+#### **D.1.3.7 501 (Not implemented)**
+
+This status code may be used if a portion of this Recommendation | International Standard that is required by the request cannot be serviced.
+
+#### **D.1.3.8 503 (Service unavailable)**
+
+This status code should be used if a channel id specified in the Channel ID request field is invalid.
+
+### **D.1.4 Impact of errors on the server state**
+
+In an event the server issues an error code different from 200 and 202, it shall not modify its state by processing request fields contained in the corresponding request and shall not return response data. The server shall, however, update the `qid`. In case the error code generated by a client-preferences request using the `"/r"` modifier is not supported by the server, and the server is operating in a session, it is desirable that the server keeps the session available for future requests.
+
+NOTE – If the server is operating in a session, an alternative option for the server would be to first return an error code and then terminate the session, e.g., return 503 for all further requests on this session.
+
+**Example:** Consider a client issuing the invalid request:
+
+```
+cid=1&rsiz=100,100&fsiz=100,100&cnew=2&roff=-1,-1
+```
+
+then the server shall report this invalid request, shall not process the request for the view window, shall not modify its cache model and shall not create a new channel. It shall abort the request and return an error code.
+
+**Example:** Consider a client issuing the valid request:
+
+```
+cid=1&rsiz=10000,10000&fsiz=10000,10000&pref=fullwindow/r
+```
+
+and the server cannot honour the *view-window pref* "fullwindow" for the requested window size, then the server shall not process the request, shall not return any data for the request, and shall issue the error code 501 including the JPIP-response header "JPIP-pref: fullwindow/r" without modifying its internal state. It should keep the session available for future requests if feasible, though.
+
+## D.2 JPIP response headers
+
+### D.2.1 Introduction to JPIP response headers
+
+In responding to a client request, the server may modify some aspects of the request. If the server modifies the request, the modified parameters shall be identified via response headers. The name of each response header is derived from the name of the request field whose parameters are being modified, by prefixing the name of the request field with "JPIP-". Unless otherwise specified, if the parameters identified in the response header had been originally specified in the client's request, then the server would have responded in the same way, except the response would now not contain these response headers. In addition, JPIP response headers may be sent by the server to inform the client of the values of other unspecified request fields for use in future requests.
+
+The JPIP-qid response is an exception in that it shall be sent whenever the client has included a Request ID in the request, and then value of JPIP-qid shall always be the same as qid.
+
+Parameters to the derived response header indicated by the same BNF element as parameters in the original request field have the same meaning and formatting as the parameters to the original request field.
+
+The only exceptions to this rule are found in connection with the New Channel and Quality response headers.
+
+### D.2.2 Target ID (JPIP-tid)
+
+JPIP-tid = "JPIP-tid" ":" LWSP target-id
+
+The server shall send this response header if the server's unique target identifier differs in any way from the identifier supplied with a Target ID request field. The target-id is an arbitrary, server-assigned string, not exceeding 255 characters in length. If the Target ID request field specifies a value of "0", the server is obliged to include a Target ID response header, indicating the actual target-id. If the server is unable to assign unique identifiers to the requested logical target, and hence cannot guarantee its integrity between multiple requests or sessions, then the Target ID response header shall specify a value of 0. If the server supplies a target-id which is different from that specified in the request, it shall disregard all model, tpmodel, need and tpneed request fields when responding to this request.
+
+### D.2.3 New channel (JPIP-cnew)
+
+JPIP-cnew = "JPIP-cnew" ":" LWSP "cid" "=" channel-id  
+["," 1#(transport-param "=" 1\*(IDTOKEN / "=" / "/" / "\"))]  
+transport-param = TOKEN
+
+The server shall send this response header if, and only if, it assigns a new channel in response to a New Channel request field. The value string consists of a comma-separated list of name=value pairs, the first of which identifies the new channel's channel-id token.
+
+The following transport-param tokens are defined by this Recommendation | International Standard (see Table D.1).
+
+Table D.1 – Valid values of transport-param
+
+| Value       | Meaning                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
+|-------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| "transport" | This parameter shall be assigned one of the values in the list of acceptable transport names supplied in the New Channel request field. If multiple transport names were supplied in the request field, the response header shall identify the actual transport that will be used with the channel.                                                                                                                                                                                                                                                      |
+| "host"      | This parameter identifies the name or IP address of the host for the JPIP server that is managing the new channel. The parameter need not be returned unless the host differs from that to which the request was actually sent.                                                                                                                                                                                                                                                                                                                          |
+| "path"      | This parameter identifies the path component of the URL to be used in constructing future requests with this channel. The parameter need not be returned unless the path name differs from that used in the request which was actually sent.                                                                                                                                                                                                                                                                                                             |
+| "port"      | This parameter identifies the numerical port number (decimal) at which the JPIP server that is managing the new channel is listening for requests. The parameter need not be returned if the host and port number are identical to those to which the original request was sent. The parameter also need not be returned if the host differs from that to which the request was sent and the default port number associated with the relevant transport is to be used.                                                                                   |
+| "auxport"   | This parameter is used with transports requiring a second physical channel. If the "http-tcp" or "http-udp" transports are used, the auxiliary port is used to connect the auxiliary channel. For further details, see Annexes G and K. The parameter need not be returned if the original request involved a channel that also employed an auxiliary channel, having the same auxiliary port number. Otherwise, the parameter need be returned only if the auxiliary port number differs from the default value associated with the selected transport. |
+
+### **D.2.4 Request ID (JPIP-qid)**
+
+```
+JPIP-qid = "JPIP-qid" ":" LWSP UINT
+```
+
+The server shall send this response header if the client's request included a Request ID `qid`. The value of `JPIP-qid` shall be identical to `qid`. The server shall not include a Request ID response header when the respective client request did not include a Request ID. The server's Request ID, `JPIP-qid`, shall always be identical to the client's Request ID. Thus the Request ID is distinctive in that this response header is sent when the client has used the Request ID, not when the server modifies the value.
+
+### **D.2.5 Frame size (JPIP-fsiz)**
+
+```
+JPIP-fsiz = "JPIP-fsiz" ":" LWSP fx "," fy
+```
+
+The server should send this response header if the frame size for which response data will be served differs from that requested via the Frame Size request field.
+
+### **D.2.6 Region size (JPIP-rsiz)**
+
+```
+JPIP-rsiz = "JPIP-rsiz" ":" LWSP sx "," sy
+```
+
+The server should send this response header if the size of the region for which response data will be served differs from that requested. A server shall only modify view-windows in accordance with Table C.8 and the description of the *view-window-prefs*, in C.10.2.2. Specifically, a server is not allowed to enlarge the requested view window. It may, however, at its discretion, transmit data outside of the requested view window in accordance with Table C.12 and the description of the *conciseness-pref*, in C.10.2.8.
+
+### **D.2.7 Offset (JPIP-roff)**
+
+```
+JPIP-roff = "JPIP-roff" ":" LWSP ox "," oy
+```
+
+The server should send this response header if the offset of the region for which response data will be served differs from that requested.
+
+### **D.2.8 Frame size for variable dimension data (JPIP-fvsiz)**
+
+```
+JPIP-fvsiz = "JPIP-fvsiz" ":" LWSP 1#UINT
+```
+
+The server should send this response header if the actual frame size differs in any way from that requested via the Frame Size or Frame Size for Variable Dimension Data field. The server might need to modify the frame size because the client requested a frame size that does not exist. It is at the discretion of the server to either return the `JPIP-fsiz` or the `JPIP-fvsiz` response header on two-dimensional data requests, both responses shall be considered equivalent in this case. In all other cases, only the `JPIP-fvsiz` response header shall be used.
+
+### **D.2.9 Region size for variable dimension data (JPIP-rvsiz)**
+
+```
+JPIP-rvsiz = "JPIP-rvsiz" ":" LWSP 1#UINT
+```
+
+The server should send this response header if the size of the view-window differs in any way from that requested via the Region Size or Region Size for Variable Dimension Data request field. If two-dimensional data had been requested, it is at the discretion of the server to pick either this response header, or the `JPIP-rsiz` response header, and both shall be considered equivalent by the client. For all other cases, only the `JPIP-rvsiz` response header shall be used.
+
+#### **D.2.10 Offset for variable dimension data (JPIP-rvoff)**
+
+```
+JPIP-rvoff = "JPIP-rvoff" ":" LWSP 1#UINT
+```
+
+The server should send this response header if the view-window offset differs in any way from that requested via an Offset or Offset for Variable Dimension Data request field. The server might need to modify the offset if it is resizing a requested view-window. For two-dimensional data, it is at the discretion of the server to pick either this response header, or the `JPIP-roff` response header, and the client shall consider both equivalent. For all other data, the `JPIP-rvoff` response header shall be used.
+
+#### **D.2.11 Components (JPIP-comps)**
+
+```
+JPIP-comps = "JPIP-comps" ":" LWSP 1#UINT-RANGE
+```
+
+The server should send this response header if the components for which it will serve data differ from those requested via the Components request field. It is not obliged to send this response header if requested image components do not exist within any of the requested codestreams.
+
+#### D.2.12 Codestream (JPIP-stream)
+
+```
+JPIP-stream = "JPIP-stream" ":" LWS 1#(prefixed-range / sampled-range)
+prefixed-range = "<" ctxt-id ":" ctxt-elt ">" sampled-range
+ctxt-id = UINT
+ctxt-elt = UINT
+```
+
+The server should send this response header to inform the client of the codestream or codestreams for which it will serve data, unless it is serving data in response to all codestreams requested directly via any Codestream request field and all codestreams requested indirectly via any Codestream Context request field. The server should use the `prefixed-range` syntax to identify those codestreams for which data is being served in response to a translated Codestream Context request field. In this case, the `ctxt-id` value shall identify the specific `context-range` from the Codestream Context request field whose translation is producing the relevant codestreams. Moreover, the `ctxt-elt` value shall identify the particular element within the `context-range` identified by `ctxt-id`, whose translation is producing the relevant codestreams.
+
+A value of 0 for the `ctxt-id` means that the first `context-range` in the Codestream Context request field is the one which produced the range of codestreams which follows the prefix. Similarly, a value of 1 for `ctxt-id` means that the second `context-range` in the Codestream Context request field is the one which produced the ensuing range of codestreams, and so forth.
+
+A value of 0 for the `ctxt-elt` means that the first context in the relevant `context-range` is the one which produced the range of codestreams which follows the prefix.
+
+Example:
+
+Client request:
+
+```
+stream=0&context=jpxl<2-7:2>[s0i0],jpxl<9-10>[s1i3]
+```
+
+Server response:
+
+```
+JPIP-context: jpxl<2-7:2>[s0i0]=0,1;jpxl<9-10>[s1i3]=0
+```
+
+```
+JPIP-stream: 0,<0:1>1,<1:0>0,<1:1>0
+```
+
+This means that the server is responding with data resulting from:
+
+- 1) the direct application of the view-window to codestream 0 (as requested via "stream=0");
+- 2) the translation of the view-window to JPX compositing layer 4, according to compositing instruction 0 in compositing instruction set 0, as it applies to codestream 1;
+- 3) the translation of the view-window to JPX compositing layer 9, according to compositing instruction 3 in compositing instruction set 1, as it applies to codestream 0; and
+- 4) the translation of the view-window to JPX compositing layer 10, according to compositing instruction 3 in compositing instruction set 1, as it applies to codestream 0.
+
+### D.2.13 Codestream Context (JPIP-context)
+
+```
+JPIP-context = "JPIP-context" ":" LWS 1$(context-range "=" 1#sampled-range)
+```
+
+The server should send this response header if it is able to process any of the `context-range` values supplied via a Codestream Context request field. The header describes each `context-range` which is being processed, along with the indices of all codestreams which are associated with that `context-range`. The server may omit some `context-range` values which were originally provided in the Codestream Context request field, if they are not being processed. The server may also modify `context-range` values originally provided in the Codestream Context request field. Two types of modification are allowed:
+
+- a) the server may restrict the collection of image elements (e.g., compositing layers) which were originally requested;
+- b) the server may drop geometric transformation modifiers which it is not able to support (e.g., a "track" or "movie" modifier within an `mj2t-context` string).
+
+### D.2.14 ROI (JPIP-roi)
+
+```
+JPIP-roi = "JPIP-roi" ":" LWS
+"roi" "=" region-name "; "
+"fsiz" "=" UINT ", " UINT "; "
+"rsiz" "=" UINT ", " UINT "; "
+"roff" "=" UINT ", " UINT "; "
+region-name = 1*(DIGIT / ALPHA / "_")
+```
+
+In response to a client request for an ROI, a server shall specify through the ROI response header the extent of the ROI actually being served. If the server is unable to fulfil the ROI request, it shall reply with the ROI response header simply set to: "JPIP-roi: roi=no-roi". In addition to the ROI, the server also specifies through the Frame Size, Region Size and Offset response headers the region of the image that it is serving as a fallback.
+
+If the server is able to serve the ROI, but for some reason needs to resize the portion of the returned image, it shall send the ROI response header describing the ROI and the Frame Size, Region Size and Offset response headers describing the part of the ROI being returned.
+
+#### D.2.15 Layers (JPIP-layers)
+
+```
+JPIP-layers = "JPIP-layers" ":" LWSP UINT
+```
+
+The server should send this response header if the number of layers for which it will serve is smaller than the value specified by the layers request field. Since the view-window is typically served in quality progressive fashion, the server is not obliged (and indeed might not be able) to determine the number of layers which are spanned by the response data it delivers. However, if the requested number of layers exceeds the number of layers available from any codestreams in the view-window, the server should at least identify the maximum number of available layers. Any server that accepts an Alignment request field (see C.7.1) shall provide a JPIP-layers response if the number of layers for which it will serve is smaller than the value specified by the layers request field.
+
+### D.2.16 Sampling rate (JPIP-srate)
+
+```
+JPIP-srate = "JPIP-srate" ":" LWSP UFLOAT
+```
+
+The server should send this response header if the average sampling rate of the codestreams which it will send to the client is expected to differ from that requested via a Sampling Rate request field and the sampling rate is known. If the source codestreams have no timing information, this response header should not be sent.
+
+### D.2.17 Metadata request (JPIP-metareq)
+
+```
+JPIP-metareq = "JPIP-metareq" ":" LWSP
+    1#( "[" 1$(req-box-prop) "]" [root-bin] [max-depth] )
+    [metadata-only]
+
+req-box-prop = box-type [limit] [metareq-qualifier] [priority]
+```
+
+The server should send this response header if it is modifying the max-depth, limit, metareq-qualifier or priority value provided in a Metadata Request request field.
+
+### D.2.18 Maximum response length (JPIP-len)
+
+```
+JPIP-len = "JPIP-len" ":" LWSP UINT
+```
+
+The server should send this response header if the byte limit specified in a Maximum Response Length request field was too small to allow a non-empty response unless the byte limit was equal to zero. If returned, JPIP-len shall be a value that informs the client of a suitable maximum response length, len, for subsequent requests. If len=0, the server should respond to the request with response headers and no response data.
+
+### D.2.19 Quality (JPIP-quality)
+
+```
+JPIP-quality = "JPIP-quality" ":" LWSP (1*2DIGIT / "100" / "-1")
+```
+
+The server can send this response header to inform the client of the quality value that will be associated with the image data returned once this request has been completed. If the request is interrupted by another request (not having "wait=yes"), this quality value might not be accurate. The quality value refers only to the view-window requested, and has the same interpretation as the Quality request field. If the server ignored the client's request, a value "-1" shall be returned.
+
+### D.2.20 Image return type (JPIP-type)
+
+```
+JPIP-type = "JPIP-type" ":" LWSP image-return-type
+```
+
+The server should include this response header unless another mechanism identifies the MIME subtype of the return image data. Examples of other mechanisms include:
+
+- an HTTP "Content-Type:" header,
+- Responses to requests that are associated with a session whose return image type has already been signalled.
+
+### D.2.21 Model set (JPIP-mset)
+
+```
+JPIP-mset = "JPIP-mset" ":" LWSP 1#sampled-range
+```
+
+The server should include this response header if the client's request contains a Model Set request field, and the collection of codestreams identified by the client's Model Set request field differ in any way from the collection of codestreams for which the server is actually prepared to maintain cache model information. The set of codestreams for which the server maintains cache model information should include all codestreams which are associated with the server's response data (either those identified in the client's request, or those identified by the server's Codestream response header, if any). Apart from those codestreams, the server's "mset" can be no larger than that identified by the client's Model Set request field.
+
+#### D.2.22 Needed capability (JPIP-cap)
+
+```
+JPIP-cap = "JPIP-cap" ":" LWSP 1#capability-code
+```
+
+This response header specifies that the client shall support a particular feature in order to interpret the logical target in a conformant manner. Valid capabilities are the same as those defined for the Capability request field in C.10.1.
+
+#### D.2.23 Unavailable preference (JPIP-pref)
+
+```
+JPIP-pref = "JPIP-pref" ":" LWSP 1#related-pref-set
+```
+
+This response header should be provided if, and only if, a Client Preferences request field contained a `related-pref-set` with the `"/r"` modifier (required), which the server was unwilling to support. In this case, an error value should also be returned for the response status code. The value string consists of one or more of the `related-pref-sets` that could not be supported, repeated in the same form as they appeared in the Client Preferences request, except that numerical parameters only need to be represented to sufficient accuracy to avoid any ambiguity in identifying the unsupported preference.
+
+Although desirable, it is not necessary for this response header to list all of the required `related-pref-sets` that cannot be supported. Thus, it is permissible for a server to walk into the Client Preferences request field only until it encounters a `related-pref-set` which specifies `"/r"` and cannot be supported. See C.10.2.1 for more information on when this response header is to be used.
+
+#### D.2.24 Alignment (JPIP-align)
+
+```
+JPIP-align = "JPIP-align" ":" LWSP "yes" / "no"
+```
+
+This response header should be provided if the server alignment guarantee differs from that requested by the client. (See C.7.1.)
+
+#### D.2.25 Subtarget (JPIP-subtarget)
+
+```
+JPIP-subtarget = "JPIP-subtarget" ":" LWSP byte-range / src-codestream-specs
+```
+
+This response header should be provided if the subtarget identified by the server differs from that requested by the client. (See C.2.3.)
+
+#### D.2.26 Handled request (JPIP-handled)
+
+```
+JPIP-handled = "JPIP-handled" ":" LWSP 1#handled-req
+handled-req = (request-field | partially-handled-req)
+partially-handled-req = request-field "=" handled-req-option
+request-field = TOKEN
+handled-req-option = TOKEN
+```
+
+The server shall include this response header in its response to a request containing the `handled` request field. This `JPIP-handled` response header identifies the requests which the server is able to handle correctly, in accordance with this Recommendation | International Standard. Each `request-field` can be any of the request fields mentioned in C.1.2, but may also include other tokens that some clients might not recognize; clients shall ignore any `request-field` they do not understand.
+
+A `partially-handled-req` can be used to indicate partial support for a request field. If the relevant request field has a finite set of possible complete parameter strings following the `"="` character (e.g., `"yes"` or `"no"`), the `handled-req-option` can be one of those values. Table D.3 describes additional values for the `handled-req-option` which are defined by this Recommendation | International Standard for use with specific request fields. Servers may include other tokens for the `handled-req-option` that some clients might not recognize. Clients shall ignore any `partially-handled-req` whose `request-field` or `handled-req-option` they do not understand.
+
+D.3 Response data
+
+For anything other than the JPP- or JPT-stream image return types, including raw codestream, the response data should consist of the requested entity in full. For JPP- or JPT-stream image return types, the response data consist of a sequence of messages as defined in Annex A, terminated by a single EOR (End Of Response) message. The EOR message is not defined in Annex A and is not formally part of the JPP- or JPT-stream media types.
+
+An EOR message consists of a header and a body. The EOR message header consists of the single byte identifier, 0x00, followed by a single byte reason code, R, and then a single VBAS byte count, indicating the number of bytes in the body of the EOR message. This Recommendation | International Standard provides no normative interpretation for the contents of the EOR message body.
+
+The EOR message, header and body, is the only message which does not contribute to the byte count restriction associated with the *Maximum Response Length* request field as defined in C.6.1.
+
+NOTE – The EOR message means that the server has delivered all the pertinent contents of the relevant data-bins for a client request. This is not necessarily the entire contents of those data-bins. The response is terminated when a client specified limit has been reached. If no limit was specified, then the EOR message would mean that all the contents of the relevant data-bins have been served.
+
+The reason codes are currently defined (see Table D.2).
+
+Table D.2 – Defined reason codes
+
+| Reason code  | Reason                 | Explanation                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
+|--------------|------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| 1            | Image done             | The server has transferred all available image information (not just information relevant to the requested view-window) to the client. This reason code has a particular meaning to session-based requests. For a session-based request, this reason code implies that the client has received all data which could be sent in response to any session-based request associated with this logical target. With the possible exception of requests which include cache management requests fields, any subsequent session-based request will be responded with no response data and R=1 EOR.                                                                          |
+| 2            | Window done            | The server has transferred all available information that is relevant to the requested view-window. This reason code has a particular meaning to session-based requests. For a session-based request, this reason code implies that the client has received all data which could be sent in response to this request and the response data was not limited by any data-limit-field ( <i>len</i> or <i>quality</i> ) in the request, or by the handling of a subsequent request. With the possible exception of requests which include cache management request fields, any subsequent repetition of the request will be responded with no response data and R=2 EOR. |
+| 3            | Window change          | The server is terminating its response in order to service a new request which does not specify <i>Wait=yes</i> .                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
+| 4            | Byte limit reached     | The server is terminating its response because the byte limit specified in a Maximum Response Length request field has been reached.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
+| 5            | Quality limit reached  | The server is terminating its response because the quality limit specified in a Quality request field has been reached.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
+| 6            | Session limit reached  | The server is terminating its response because some limit on the session resources, e.g., a time limit, has been reached. No further request should be issued using a channel ID associated with that session.                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
+| 7            | Response limit reached | The server is terminating its response because some limit, e.g., a time limit, has been reached. If the request is issued in a session, further requests can still be issued using a channel ID associated with that session.                                                                                                                                                                                                                                                                                                                                                                                                                                        |
+| 0xFF         | Non-specified reason   | The server is terminating its response for a reason that is not specified.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
+| Other values |                        | Reserved for ISO use.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
+
+Table D.3 – Additional ~~handled-req-option~~ values for particular request fields
+
+| request-field | handled-req-option              | Meaning                                                                                                                                  |
+|---------------|---------------------------------|------------------------------------------------------------------------------------------------------------------------------------------|
+| Cnew          | transport-name                  | The server correctly handles new-channel request fields that contain the indicated transport type.                                       |
+| Context       | "jplx", "mj2t", "jpmpr", "jpxf" | The server correctly handles codestream context request fields for context-range values that commence with the handled-req-option token. |
+
+## Annex E
+
+### Uploading images to the server
+
+(This annex forms an integral part of this Recommendation | International Standard.)
+
+#### E.1 Introduction
+
+It is anticipated that images will be placed on a server in a variety of ways outside of the scope of this Recommendation | International Standard. The purpose of this annex is to describe a mechanism that allows portions of an image to be uploaded to a server.
+
+#### E.2 Upload request
+
+##### E.2.1 Request structure
+
+An upload request consists of one or more request fields defined in Annex C, and a request body.
+
+##### E.2.2 Upload request fields
+
+The request fields for an upload shall contain an Upload request field. The Target, Sub-target and Target ID request field (see C.2.2, C.2.3, and C.2.4) can also be used. For an upload of a complete image media type, the Frame Size, Offset and Region Size request fields (see clauses C.4.2, C.4.3, and C.4.4) are used to indicate the position of the uploaded portion within the entire image. For uploads of JPT-stream and JPP-stream, the number of the data-bin (and hence the tile or precinct number) along with the main header indicate the location of the coded data and the view-window request fields are unnecessary.
+
+##### E.2.3 Upload request body
+
+###### E.2.3.1 General
+
+The body of an upload request consists of one of the supported image types: JPP-stream, JPT-stream, or a complete image media type. The body contains the data that the client is requesting to have handled by the server. This Recommendation | International Standard does not support uploading raw image data.
+
+###### E.2.3.2 JPT-stream
+
+The body of the request contains all data-bins the client wants the server to replace (header data-bins, metadata-bins, and tile data-bins). If the client does not upload a main header data-bin the tile data-bins shall be encoded in a compatible manner with the current main header.
+
+###### E.2.3.3 JPP-stream
+
+The body of the request contains all data-bins the client wants the server to replace (header data-bins, tile header data-bins, metadata-bins, and precinct data-bins). If the client does not upload a main header data-bin or tile header data-bin the precincts shall be encoded in a compatible manner with the current main and tile-headers.
+
+###### E.2.3.4 Complete image upload
+
+The body of the request contains a complete image media type representing those samples the client wishes to modify.
+
+In the case of a complete image upload, the request can include Frame Size, Region Size and Offset request fields. The Frame Size request field shall be the size of the reference grid of the image. In the case of a complete image upload, the compression need not be done in a compatible way with the logical target on the server. If the size of the uploaded image exceeds the extent in the Region Size request field, the server should limit modifications to the extent specified in the Region Size request field.
+
+#### E.3 Server response
+
+##### E.3.1 General
+
+The server shall respond to an upload request with a status code and reason phrase from Annex D. Useful return codes and reason phrases for image upload are presented in the following subclauses.
+
+**E.3.2 201 (Created)**
+
+The server should use this status code if, upon receiving an upload request, a new resource has been defined on the server. The server shall have completed the creation before returning this request. If there will be a delay, the server should return 202 (Accepted) instead of 201 (Created).
+
+The server should include a header with the response with a new target ID field for the updated resource.
+
+No body need be returned.
+
+**E.3.3 202 (Accepted)**
+
+The server should use this status code if an upload creates a new resource but the server is not yet prepared to serve it. The server may also use this status code for an update of a current resource.
+
+**E.3.4 400 (Bad request)**
+
+Servers should issue this status code if the request is incorrectly formatted, or if the query contains request fields that are incompatible with uploading or contains an unrecognized field in the query string.
+
+**E.3.5 404 (Not found)**
+
+This status code should be issued if the server cannot reconcile the requested resource with an issued target ID.
+
+**E.3.6 415 (Unsupported media type)**
+
+This status code may be issued to indicate that while uploads are supported, uploads of the particular type (e.g., complete image, JPT-stream, or JPP-stream) included with the request are not supported.
+
+**E.3.7 501 (Not implemented)**
+
+This status might be used if the server does not support upload or does not support a particular option with upload.
+
+**E.4 Merging data on the server****E.4.1 Updating the image**
+
+After receiving the uploaded data, the server can create a new version of the logical target and provide the new version to clients accessing a new or the old URL. However, the server shall not use the old Target ID request field to provide access to any merged or updated data.
+
+If the client includes a Target ID request field in the upload request and that target ID does not match the server's current target ID for the resource, the server should not update the image. This mismatch might indicate the client has edited a previous version of the image that has already been modified. Servers may refuse to accept uploads which do not contain a Target ID request field. This is one way to prevent multiple simultaneous edits of a target by different clients. Servers providing editing capabilities can take care of such issues as target locking by some other means.
+
+A JPIP client can upload part of a new image by specifying a target ID of 0, or using a new URL, or target which the server does not have. The server should issue a target ID for the upload. A client may continue to upload additional portions of the new image by using the target ID returned by the server with the previous upload.
+
+**E.4.2 JPT-stream**
+
+A server accepting tile data-bin data shall first remove all the old tile data-bin data for those tiles being uploaded, and then include the new tile data-bin data into the codestream. An update cannot be made that results in a change to the number or dimension or location of tiles: the structure of the image cannot be changed by an upload. In particular, a server should not accept tile data-bin uploads for a codestream containing a PPM marker segment in the main header, unless the client provides a new main header with the upload. Any PLM or TLM marker segments shall be deleted or updated. A JPT-stream main header data-bin shall be uploaded for new images.
+
+How the codestream tile-parts from a tile data-bin are formed is not specified. The client need not necessarily provide all tile-parts of a tile, nor need the last tile-part be completed. The server shall update the main header and any portions of the file format affected (for example length of the codestream box).
+
+When merging data, the number or size of tiles shall not be changed and data that is not replaced by the upload process shall have the same meaning as it originally had before the upload.
+
+### E.4.3 JPP-stream
+
+A server accepting precinct data-bin messages shall first remove the corresponding old precinct data-bins for those precincts being uploaded, and then include the new precinct data-bin data. A change cannot be made to a header that results in a change to the number of precincts, or the meaning of the precinct identifier, or the location or size of each precinct within its tile-component-resolution. JPP-stream tile header data-bins and main header data-bins shall be uploaded for new images.
+
+How the precinct packets from a precinct data-bin are formed is not specified. The client need not necessarily provide all packets of a precinct, or even complete the last provided packet.
+
+When merging data, the number or size of precincts shall not be changed and data that is not replaced by the upload process shall have the same meaning as it originally had before the upload.
+
+### E.4.4 JPP-stream and JPT-stream metadata-bins
+
+Metadata-bin can be uploaded, replacing the contents in an existing metadata-bin. Since the server has control of the division of allocating metadata into metadata-bins, the client shall follow the server's metadata-bin structure. The client shall not change placeholders in a metadata-bin, except to completely remove a placeholder. When uploading an entire metadata-bin, clients can add new metadata by appending to the end of the old metadata-bin, or by inserting new metadata between boxes in the old metadata-bin. The server shall manage the placeholders and the metadata-bin structure. This includes updating all placeholders pointing to any decedent metadata boxes that have been changed or affected by the change. The server shall delete any metadata boxes that were pointed to by a placeholder that the client has removed. The server may re-structure the metadata after an upload is accepted, but before the new resource is created. If unused sections are left in the file after uploading, Free boxes shall be used to fill those sections.
+
+### E.4.5 Complete image upload
+
+In the case of an acceptable complete image upload, the server should uncompress (if required) the uploaded sub-image, uncompress some portion of the full image on the server, replace those pixels in the (uncompressed) spatial domain and recompress all tiles or precincts affected by the update operation.
+
+NOTE – This technique requires more computation on the server; however, it removes the possibility that the client will use compressed image data in an incompatible way (e.g., the wrong number of levels of wavelet transform).
+
+## Annex F
+
+### Using JPIP over HTTP
+
+(This annex forms an integral part of this Recommendation | International Standard.)
+
+#### F.1 Introduction
+
+This annex defines the method to use JPIP with the HTTP protocol, as defined in RFC 2616, for both requests and responses. The JPIP request parameters from Annex C are encapsulated in Valid HTTP request structures. The server responses (including status codes, headers, messages, and response codes) from Annex D are encapsulated in valid HTTP responses. All requests and responses shall be encoded as specified by the HTTP standard.
+
+The text and examples in this annex describe the use of JPIP over HTTP. The same binding shall be used for secure HTTP (or HTTPS).
+
+#### F.2 Requests
+
+##### F.2.1 Requests introduction
+
+Annex C defines request fields. When transported via HTTP, the JPIP request can appear as a query string for an HTTP "GET" request or as the body of an HTTP "POST" request. Because some HTTP systems limit the length of the query string provided in a "GET" request, the "POST" request is preferred for long JPIP requests.
+
+NOTE 1 – The HTTP Request is defined in RFC 2616 as:
+
+```
+Request = Request-Line           ; HTTP Section 5.1
+        0*(( general-header      ; HTTP Section 4.5
+           / request-header      ; HTTP Section 5.3
+           / entity-header ) CRLF) ; HTTP Section 7.1
+        CRLF
+        [ message-body ]         ; HTTP Section 4.3
+```
+
+NOTE 2 – The HTTP Request-Line and Request-URI are defined in RFC 2616 as:
+
+```
+Request-Line = Method SP Request-URI SP HTTP-Version CRLF
+
+Request-URI = "*" / absoluteURI / abs_path / authority
+```
+
+NOTE 3 – RFC 3986 defines:
+
+```
+absoluteURI    = absolute-URI
+absolute-URI   = scheme ":" hier-part [ "?" query ]
+hier-part      = "//" authority path-abempty
+               / path-absolute
+               / path-rootless
+               / path-empty
+path-abempty   = *( "/" segment )
+path-absolute = "/" [ segment-nz *( "/" segment ) ]
+path-rootless =      segment-nz      *(      "/"      segment      )
+path-empty    =                               =                               0<pchar>
+segment       = *pchar
+segment-nz    = 1*pchar
+```
+
+##### F.2.2 GET requests
+
+A JPIP request can be provided to a server as a HTTP request. For a "GET" request the HTTP request is restricted in the following manner:
+
+- The "Method" shall be "GET".
+- The "query" shall be zero or more `jpip-request-field` separated by '&'.
+
+An example of a JPIP request encapsulated in an HTTP "GET" request is:
+
+```
+GET /images/kids.jp2?rsiz=640,480&roff=320,240&fsiz=1280,1024 HTTP/1.1
+
+Host: get.jpeg.org
+
+CRLF
+```
+
+An equivalent example using an `absoluteURI` instead of an `abs_path` is:
+
+```
+GET http://get.jpeg.org/images/kids.jp2?rsiz=640,480&roff=320,240
+&fsiz=1280,1024 HTTP/1.1
+```
+
+CRLF
+
+NOTE – This Recommendation | International Standard imposes no restriction on the scheme component of the absoluteURI.
+
+### F.2.3 POST requests
+
+A JPIP request can be provided to a server encapsulated in an HTTP "POST" request. For a "POST" request the HTTP request is restricted in the following manner:
+
+- The "Method" shall be "POST".
+- The "entity-body" shall be zero or more `jpip-request-field` separated by '&'.
+- The "Content-type:" header line should be included as an "entity-header" and contain the value "application/x-www-form-urlencoded".
+
+An example of a JPIP request encapsulated in an HTTP "POST" request is:
+
+```
+POST /cgi-bin/j2k_server.cgi HTTP/1.1
+Host: post.jpeg.org
+Content-type: application/x-www-form-urlencoded
+Content-length: 62
+CRLF
+target=/images/kids.jp2&rsiz=640,480&roff=320,240&fsiz=1280,1024
+```
+
+### F.2.4 Upload requests
+
+An upload request is a valid HTTP request restricted as follows:
+
+- The "Method" shall be "POST".
+- The URL shall contain the upload query-field.
+- The Content-type shall be the image type of the body: `image/jpt-stream`, `image/jpp-stream`, or a complete image media type.
+
+An example of a JPIP upload request is:
+
+```
+POST /images/kids.jp2?rsiz=640,480&roff=320,240&fsiz=1280,1024 HTTP/1.1
+Host: post.jpeg.org
+Content-type: image/jpt-stream
+CRLF
+```
+
+## F.3 Session establishment
+
+A session-based HTTP (or HTTPS) session is established by using the New Channel request field with a value of "http" (or "https"), i.e., "cnew=http" (or "cnew=https") as part of a request. This request is typically delivered by HTTP (or HTTPS). The request can contain a view-window request that becomes the first request in the new channel. The response to this request is returned on the same connection as the request was made.
+
+A client can open an HTTP (or HTTPS) connection and issue a request which includes the HTTP (or HTTPS) header "Connection: keep-alive". This is useful for efficient sessions, but it is neither necessary nor sufficient to have a session. A single HTTP (or HTTPS) connection may be used for traffic for different targets, different channels, or even non-JPIP traffic, e.g., requests for HTML files. A JPIP request that is part of a session can arrive on HTTP (or HTTPS) connections other than the HTTP (or HTTPS) connection used to request and issue the new channel, although this is discouraged.
+
+## F.4 Responses
+
+### F.4.1 Introduction
+
+Each component of a response from Annex D may be encapsulated as a portion of a valid HTTP response.
+
+NOTE – The HTTP Response is defined in RFC 2616 as:
+
+Response = Status-Line ; HTTP Section 6.1
+
+```
+
+0*(( general-header           ; HTTP Section 4.5
+   / response-header         ; HTTP Section 6.2
+   / entity-header ) CRLF)    ; HTTP Section 7.1
+CRLF
+[ message-body ]             ; HTTP Section 7.2
+
+```
+
+JPIP responses transported over HTTP shall be valid HTTP responses, with further limitations on some of the parts of the HTTP response as described in the following subclauses.
+
+#### **F.4.2 Status code and reason-phrase**
+
+All of the status codes listed in D.1.3 may be used directly as HTTP status codes. In addition, a server providing JPIP over HTTP may use any HTTP status code deemed useful, e.g., 402.
+
+All values for Reason-Phrase provided in D.1.3 may be used directly as HTTP Reason-Phrase. The Reason-Phrase shall be appropriate for the status code. A server providing JPIP over HTTP may use any HTTP Reason-Phrase deemed useful, e.g., Payment required.
+
+#### **F.4.3 Header information**
+
+##### **F.4.3.1 JPIP headers**
+
+The header lines from D.2 shall be included as the "entity-header" in the HTTP response without modification.
+
+##### **F.4.3.2 Use of HTTP Accept header**
+
+A server providing JPIP over HTTP can use an HTTP "Accept:" header line found in a request to determine the type of JPIP response. If the request contains a "type=" query parameter, the return type shall be one of the types listed in the type parameter. If the request contains both a "type=" query parameter and an "Accept:" header line, the server can use the priorities specified in the "Accept:" line to select between the types specified in the "type=" query parameter. If no "type=" query parameter is present in the request, the server may select a return type supported by the underlying JPIP server from the list of types in the "Accept:".
+
+##### **F.4.3.3 Use of Cache-Control header**
+
+Caches in HTTP proxies are different from the caches and cache models in JPIP.
+
+Any JPIP request with a New Channel request field is part of a session and such responses cannot generally be cached by HTTP proxy servers. Similarly, any response which includes a New Channel response header is also part of a session. In both cases, the server's response should include an HTTP "Cache-Control:" header line with the value "no-cache".
+
+##### **F.4.3.4 Use of Content-type header**
+
+A server providing JPIP over HTTP should include a "Content-type:" header line, indicating the type of data in the body, most commonly this is image/jpp-stream or image/jpt-stream.
+
+##### **F.4.3.5 Use of Redirect header**
+
+The HTTP Redirect header can be useful to inform a client that the resources has moved or should be accessed from a different host.
+
+Note that the JPIP response defines a way to do a redirect as well. The JPIP response should be preferred within a session.
+
+#### **F.4.4 Body**
+
+The messages from Annex D shall be included as the body of the HTTP response. An HTTP response shall have a mechanism to determine the length of the response. If the server does not plan to interrupt a response, it can provide this information with a "Content-Length" HTTP header line. The preferred method of providing the length is to use the HTTP header line "Transfer-Encoding: chunked" and then to provide the body in chunks of a size determined by the server and specified before each chunk. Indicating the end of a response by closing the HTTP connection is discouraged.
+
+### **F.5 Additional HTTP features**
+
+#### **F.5.1 Use of HTTP HEAD method**
+
+JPIP clients and servers are not required to use or support the HTTP "HEAD" method. A server choosing to implement the "HEAD" method shall do so as specified in section 9.4 of RFC 2616. In particular, "The HEAD method is identical to GET except that the server shall not return a message-body in the response."
+
+Clients might find it useful to issue HTTP "HEAD" requests as a means to determine if the server will modify any of the request parameters as specified in Annex D. Clients should not issue a HTTP "HEAD" request with cache model query fields as this might cause the server to update its cache model.
+
+NOTE – A client wishing to update the server cache model without receiving a response can use the Maximum Response Length request field.
+
+Servers may refuse any or all "HEAD" requests. Unlike typical HTTP "HEAD" requests that require relatively little effort for a server to fulfil, some JPIP server implementations might have to obtain data from several locations in a logical target, compute the nature of the response, and then discard the body of the response in order to respond to a "HEAD" request.
+
+### **F.5.2 Use of HTTP OPTIONS method**
+
+JPIP clients and servers are not required to use or support the HTTP "OPTIONS" method.
+
+### **F.5.3 Etag usage**
+
+Note that HTTP defines the entity tag (ETag) mechanism that is similar to the JPIP Target ID request field in that it is used to denote changes in a resource. If both an entity tag and a target ID are associated with a resource, it is recommended that the ETag defined by HTTP be changed whenever the `target-id` is changed.
+
+### **F.5.4 Use of chunked transfer encoding**
+
+Because responses containing compressed data can be very large and thus take a long time to transmit, it is important to be able to stop in the midst of transmission. Unless "Transfer-Encoding: chunked" is specified, HTTP requests shall specify the full length of the body in a "Content-Length:" header or indicate the end of data by closing the connection. Neither of these is desirable in an interactive protocol, since it might be necessary to stop the current response and send more data on the same connection for a new response.
+
+NOTE 1 – RFC 2616 provides an algorithm for removing the chunked transfer encoding.
+
+NOTE 2 – Chunked transfer encoding might be useful with JPIP when delivered over protocols other than HTTP.
+
+## **F.6 HTTP and length request field (informative)**
+
+With a HTTP return channel, the server does not receive continuous feedback from the client and can easily push a great deal of data into the pipe, which needs to be fully received before any data for a new window can be processed. To maintain responsiveness, clients should use the Maximum Response Length request field to regulate the flow of traffic and hence maintain responsiveness. Clients will generally need to implement their own flow control algorithms to adjust the request length to changing network conditions.
+
+## Annex G
+
+### Using JPIP with HTTP requests and TCP returns
+
+(This annex forms an integral part of this Recommendation | International Standard.)
+
+#### G.1 Introduction
+
+The JPIP protocol itself is neutral with respect to underlying transport mechanisms for the client requests and server responses, except in regard to channel requests represented by the New Channel ("*cnew*") request field (see C.3.3) and the New Channel ("*JPIP-cnew*") response header (see D.2.3), where transport-specific details shall be communicated. This Recommendation | International Standard defines four specific transports, which are identified by the strings "*http*", "*https*", "*http-tcp*" and "*http-udp*" in the value string associated with New Channel requests. This annex provides details of the "*http-tcp*" transport, which shall be identified in this text as HTTP-TCP. The first transport is identified in this text as HTTP and is described in Annex F. The "*http-udp*" transport type is identified in this text as HTTP-UDP and is defined in Annex K.
+
+The HTTP-TCP transport uses exactly the same mechanisms as the HTTP transport to send client requests to the server and receive the server's response headers and status codes. However, the server's response data (not the response headers) is delivered over an auxiliary TCP connection. The information transported on this auxiliary TCP connection is identical to that which would have been transported as the entity body of a pure HTTP response, except that it is framed into chunks, each of which has a chunk sequence number.
+
+The client explicitly acknowledges the arrival of each chunk by sending its sequence number back to the server on the auxiliary TCP connection's return path. One of the principle benefits of the HTTP-TCP transport is that the server receives incremental notification of the arrival of its response data chunks via this client acknowledgement mechanism. This allows the server to manage the flow of data in such a way as to maintain responsiveness and network efficiency.
+
+All requests sent over the HTTP transport shall be encoded as specified by the HTTP standard.
+
+#### G.2 Client requests
+
+Requests are delivered on the primary channel exactly as HTTP requests. They have exactly the same form as requests issued over a channel that uses the HTTP transport described in Annex F. In particular, HTTP "GET" and "POST" requests may both be used.
+
+#### G.3 Session establishment
+
+##### G.3.1 Channel establishment
+
+A new channel can be established to a JPIP server by issuing a request that includes the New Channel request field (see C.3.3). As an example, such a request might be issued using HTTP, although it might also be issued to a JPIP-specific server using any suitable transport mechanism. If the server's response (through the New Channel response header in D.2.3) indicates that a new channel has been created to work with the HTTP-TCP transport, the client shall establish the auxiliary TCP connection using the auxiliary port number returned via the New Channel response header. Furthermore, the request which included the New Channel request field is then treated as though it had been issued within the newly created HTTP-TCP transported channel, meaning that the response data generated by that request shall be returned via the auxiliary TCP connection, as soon as it has been connected.
+
+To establish the auxiliary TCP connection, the client issues a TCP connection request to the server host identified via the New Channel response header, on the port identified by the New Channel response header. The client then immediately sends a single line of ASCII text, consisting of the new channel-id string, followed by two consecutive CR-LF pairs. This is the only text-oriented communication delivered over the auxiliary TCP connection.
+
+The client then waits to receive the server's response data over the auxiliary TCP connection. This response data cannot be empty, since every request issued within an HTTP-TCP transported channel shall have a response data stream that consists of at least the EOR message (see D.3). See G.4 for more on this.
+
+##### G.3.2 Server framing of response data
+
+All response data sent by the server via the auxiliary TCP connection shall be framed into chunks. Each chunk consists of an 8-byte chunk header, followed by the chunk body that holds the server's response data, as shown in Figure G.1. The first 2-byte word of the chunk header holds an unsigned big-endian integer representing the total length of the chunk, including the length word itself. The contents of the remaining 6 bytes of the chunk header are not defined by this
+
+Recommendation | International Standard. They can be used for additional server-specific signalling. The client will return the entire 8-byte chunk header in its chunk acknowledgement messages.
+
+![Diagram of response data structure on http-tcp connection. It shows a rectangular block divided into three parts: 'Size' (a small vertical rectangle), 'server specific' (a larger rectangle), and 'chunk body' (a hatched rectangle). A bracket above the first two parts is labeled 'chunk header'. A bracket above the hatched part is labeled 'chunk body'. A double-headed arrow below the entire block is labeled 'chunk length (byte)'. The label 'T.808_FG.1' is to the right of the diagram.](90183a52275501da5a0fd5c63d837009_img.jpg)
+
+Diagram of response data structure on http-tcp connection. It shows a rectangular block divided into three parts: 'Size' (a small vertical rectangle), 'server specific' (a larger rectangle), and 'chunk body' (a hatched rectangle). A bracket above the first two parts is labeled 'chunk header'. A bracket above the hatched part is labeled 'chunk body'. A double-headed arrow below the entire block is labeled 'chunk length (byte)'. The label 'T.808\_FG.1' is to the right of the diagram.
+
+**Figure G.1 – Response data structure on http-tcp connection**
+
+### G.3.3 Client acknowledgement of server response chunks
+
+Upon receipt of a server response data chunk on the auxiliary TCP connection, the client shall send the 8-byte chunk header back to the server as an unframed stream of data, using the TCP connection's return path. Each received chunk is to be acknowledged in sequence.
+
+### G.4 Server responses
+
+In response to each client request, the server sends an HTTP reply paragraph back to the client over the primary channel. The reply paragraph contains the status code, reason phrase and all relevant JPIP response headers and any appropriate HTTP response headers. However, no response data is returned via the primary channel. For this reason, there shall be no HTTP entity body in an HTTP-TCP response. Neither shall the "Content-length:" or the "Transfer-encoding:" HTTP response headers be used.
+
+The response data itself is delivered over the auxiliary TCP channel, framed into chunks in the manner described in G.3.2. Since the HTTP-TCP transport can only be used with sessions and hence only with JPP-stream and JPT-stream image return types, the response data invariably consists of a sequence of JPP-stream or JPT-stream messages.
+
+The response data resulting from each request shall consist of a whole number of chunks, meaning that no chunk is permitted to contain response data generated in response to two different requests.
+
+The response to each and every request shall be terminated with an EOR message (see D.3), even if the response data would otherwise have been empty. The EOR message is considered as part of the response data and is framed into chunks along with the actual JPP-stream and JPT-stream messages.
+
+This means that every request issued on an HTTP-TCP transported JPIP channel results in the generation of at least one non-empty response chunk from the server and that the last chunk generated in response to each request terminates with the EOR message.
+
+Note that there is no actual requirement for HTTP-TCP transported response chunks to be aligned on message boundaries.
+
+### G.5 TCP and length request field (informative)
+
+There might be little or no reason for using the Maximum Response Length request field with a TCP return channel, where the server is able to carefully regulate the flow of response data to the client so as to maintain responsiveness.
+
+## Annex H
+
+### Using JPIP with alternate transports
+
+(This annex does not form an integral part of this Recommendation | International Standard.)
+
+#### H.1 Introduction
+
+The purpose of this annex is to provide guidelines on the deployment of JPIP over unreliable transports and provides a generic approach which can be applied to a wide variety of transports, in addition to the HTTP-UDP transport that is specified in Annex K.
+
+In developing the general approach, it is helpful to divide aspects of the communication into two logical transport connections, termed the "request connection" and the "data connection". Each logical connection is understood to provide both a forward communication path and a reverse communication path. The roles played by these paths are as follows:
+
+- The forward request connection path is used to deliver JPIP requests from the client to the server.
+- The reverse request connection path is used by the server to acknowledge the receipt of requests and return response headers to the client.
+- The forward data connection path is used to deliver JPIP stream messages from the server to the client.
+- The reverse data connection path is used by the client to acknowledge receipt of JPIP stream messages from the server.
+
+The reader will observe that these roles are consistent with those served by the forward and reverse communication paths of the two TCP channels used by the "http-tcp" transport described in Annex G. Indeed, the material in this annex can be interpreted as an extension of the "http-tcp" transport to unreliable transports. However, although this annex is described in terms of two different logical connections, there is no reason why the communication cannot be carried over a single transport connection.
+
+Finally, it is assumed that each logical connection provides one of the following two types of services:
+
+- a) A reliable stream-oriented service, such as that offered by TCP.
+- b) An unreliable packet-oriented service (for example, see "http-udp" in Annex K). In this case, packets might arrive out of order or not at all.
+
+Two scenarios are considered in this annex. In the first case, the request connection path is assumed to offer a reliable stream-oriented service, but the data connection path is unreliable. In the second case, both the request and data connection paths are unreliable. It is helpful to treat these two scenarios in order.
+
+#### H.2 Reliable requests with unreliable data
+
+In this clause, the request connection is reliable, meaning that requests arrive at the server in order without loss, and server responses are received by the client in order and again without loss. In this case, the request fields and response headers can be communicated exactly as in the "http-tcp" protocol, and indeed HTTP is recommended for the transport of requests and response headers.
+
+The JPIP stream messages, including the EOR message (see D.3), shall be partitioned into packets and delivered over the unreliable data connection.
+
+The following general guidelines should be observed when constructing transport protocols of this type:
+
+- a) Each request should include a Request ID request field (see C.3.5).
+- b) For each request, there shall be a corresponding EOR message, even if no JPIP stream messages are sent in response to the request. This requirement also applies in the case of the "http-tcp" transport.
+- c) Each data connection packet constructed by the server shall consist of a whole number of JPIP stream messages and/or EOR messages. Moreover, the first JPIP stream message in each packet shall contain a complete header, not relying upon repetition of the codestream identifier or class code components of a previous message.
+- d) All JPIP stream messages (not necessarily EOR messages) found in a data connection packet shall belong to the response from a single request, and the corresponding Request ID shall be encoded in the packet's header.
+- e) EOR messages may be found either at the end of a packet bearing the same Request ID value as the request whose response is being ended, or in a block of one or more consecutive EOR messages found at the start of the first packet following the last packet bearing that Request ID. This policy allows EOR messages
+
+corresponding to one or more consecutive empty responses (e.g., due to pre-empted requests) to be bundled into the first packet of the subsequent non-empty response.
+
+- f) In addition to the Request ID value, each packet header should include a packet sequence number. The packet sequence counter is set to 0 for the first packet associated with any particular Request ID value. Subsequent packets with the same Request ID value have consecutive sequence numbers. This policy allows a client to identify any EOR messages which might not have been received due to packet loss. It is important that a client be able to associate requests with response data, so as to synchronize the effects of cache model manipulation statements at the server with the state of their own cache.
+- g) Clients shall acknowledge the receipt of each packet by sending acknowledgement messages to the server on the response data connection path. Each acknowledgement message should contain a replica of the received packet's header, but might conceivably contain additional information. The client can, at its discretion, aggregate acknowledgement messages to several packets when constructing acknowledgement packets. However, excessive aggregation can affect the reliability with which servers can estimate network statistics.
+- h) The server is not obliged to retransmit any unacknowledged packet and clients should not expect retransmission of missing packets. An intelligent server might, for example, choose to retransmit unacknowledged packets depending upon their relevance to the current view-window.
+
+### H.3 Unreliable requests with unreliable data
+
+This subclause is concerned with transports where both the request and data connections are unreliable. Guidelines for the data connection are exactly as described in H.2 for the case where data are delivered unreliably. With an unreliable request connection, however, it is possible that one or more requests might be lost or arrive out of order at the server. JPIP is well adapted to handling this situation, since servers have the freedom to pre-empt previous requests when a new request arrives.
+
+The following general guidelines should be observed when handling unreliable requests, in addition to those listed in H.2 for unreliable data connections.
+
+- a) Each request packet should include a header, identifying the value of the Request ID.
+- b) Each request packet should also include a sequence number, carrying sufficient information to determine whether or not all packets associated with a request have been received.
+- c) In many cases, servers can simply ignore missing request packets when a new request arrives. To do this, the server has only to send EOR messages on the data connection, indicating that the missing request was pre-empted immediately. There is no need for acknowledgement messages to be sent in response to request packets. There is no need for any response headers to be sent in response to requests which are being immediately pre-empted because some or all of the request packets were lost.
+- d) For each request which arrives in full at the server, the server should send one or more response packets which identify the Request ID and include any response headers. This is true even if the request arrives after the response was issued to any subsequent requests (e.g., because some packets of the request were unduly delayed). This provides the client with a mechanism for determining whether or not an important request was received by the server.
+- e) Certain types of requests shall be processed by the server to avoid loss of synchronization with the client. The most important of these are requests which include subtractive cache model manipulation fields. To enable the server to detect such requests, without having to fully serialize the request stream, request packet headers should include the following two fields:
+  - 1) A flag indicating whether or not the packet belongs to a request which shall be processed before processing subsequent requests.
+  - 2) The Request ID associated with the most recent request for which the flag mentioned in e1 was set.
+
+If the server does not receive one or more packets of a request with flag e1 set (i.e., requests with condition e2 arrive and the request with flag e1 is missing), it shall idle until the client retransmits the packets.
+
+### H.4 Request and response syntax
+
+The request and response syntax described in Annexes C and D should be followed when designing new transports for the JPIP protocol. However, it is permissible to develop equivalent binary representations of various request fields and response headers.
+
+## **H.5 Session establishment**
+
+The New Channel request field (see D.2.3) and corresponding response header can be used to create channels associated with transport protocols other than the "http" and "http-tcp" transports described normatively in this Recommendation | International Standard. The procedure for creating channels for new transports should follow the same general conventions outlined for "http-tcp". In particular, the response headers for the request which creates the new channel should be returned on the transport that was used to create the channel, while response data should be delivered using the new channel's transport.
+
+## Annex I
+
+### Indexing JPEG 2000 files for JPIP
+
+(This annex forms an integral part of this Recommendation | International Standard.)
+
+#### I.1 Introduction (informative)
+
+The Rec. ITU-T T.8xx | ISO/IEC 15444-x family of Recommendations | Standards define a family of JPEG 2000 file formats. The family utilizes a common syntax, whose basic element is the container called a box. This annex defines new file format boxes containing indexing information, the inclusion of which in JPEG 2000 family files might facilitate the deployment of those files in a JPIP system, by enabling file readers to locate within the files the elements that are required to construct images incrementally.
+
+In particular, these boxes might be useful:
+
+- to a server-side implementation of the JPIP protocol;
+- to a client accessing an image remotely, using a simpler protocol, which allows access to specified byte-ranges of the file.
+
+This annex defines index boxes corresponding to both file-level information and codestream information. The boxes can be categorized as follows:
+
+- The Codestream Index (cidx) superbox indexes codestream information corresponding to the main header, tile header, tile and precinct data-bin classes of the JPP-stream and JPT-stream. It contains a Codestream Finder (cptr) box pointing to the indexed codestream, a Manifest (manf) box summarizing the rest of the contents, and index table boxes, which are the Header Index Table (mhix) box, the Tile-part Index Table (tpix) superbox, the Tile Header Index Table (thix) superbox, the Precinct Packet Index Table (ppix) superbox and the Packet Header Index Table (phix) superbox. The index table boxes correspond to the different types of codestream data represented by data-bin classes in the JPP-stream and the JPT-stream defined in Annex A. The index table boxes which are superboxes contain Fragment Array Index (faix) boxes or Header Index Table listing the actual codestream elements. The Header Index Table, Precinct Packet and Packet Header index table superboxes also each contain a Manifest box.
+- The File Index (fidx) superbox indexes file-level information corresponding to the metadata-bin class of the JPP-stream and JPT-stream. Unless it indexes the top level of the file, in which case it is called a root File Index box, it contains a File Finder (fptr) box pointing to the indexed superbox. It can contain Proxy (prxy) boxes representing the contents of the indexed file or superbox.
+- The Index Finder (iptr) box points to a root File Index, enabling its location to be discovered.
+
+Figure I.1 illustrates an example JPEG 2000 file containing JPIP index boxes:
+
+![Diagram showing the structure of a JPEG 2000 file containing JPIP index boxes. The boxes are arranged in a sequence: 'iptr' box, 'jp2c' box, a stack of boxes ('cidx', 'cptr', 'manf', 'mhix', 'tpix', 'thix', 'ppix', 'phix'), 'fidx' box, and 'prxy' box. Arrows indicate the flow from 'iptr' to 'jp2c', from 'jp2c' to the stack, and from the stack to 'fidx'. A dashed arrow points from 'iptr' to the stack. A solid arrow points from 'fidx' to 'prxy'. A label 'T.808_FI.1' is at the bottom right.](487c58c79e44e6cf98b6368b6667b9c6_img.jpg)
+
+The diagram illustrates the structure of a JPEG 2000 file containing JPIP index boxes. It shows a sequence of boxes: 'iptr' box, 'jp2c' box, a stack of boxes ('cidx' box, 'cptr' box, 'manf' box, 'mhix' box, 'tpix' box, 'thix' box, 'ppix' box, 'phix' box), 'fidx' box, and 'prxy' box. Arrows indicate the flow: a solid arrow from 'iptr' to 'jp2c', a dashed arrow from 'iptr' to the stack, a solid arrow from 'jp2c' to the stack, and a solid arrow from the stack to 'fidx'. A solid arrow also points from 'fidx' to 'prxy'. The label 'T.808\_FI.1' is located at the bottom right of the diagram.
+
+Diagram showing the structure of a JPEG 2000 file containing JPIP index boxes. The boxes are arranged in a sequence: 'iptr' box, 'jp2c' box, a stack of boxes ('cidx', 'cptr', 'manf', 'mhix', 'tpix', 'thix', 'ppix', 'phix'), 'fidx' box, and 'prxy' box. Arrows indicate the flow from 'iptr' to 'jp2c', from 'jp2c' to the stack, and from the stack to 'fidx'. A dashed arrow points from 'iptr' to the stack. A solid arrow points from 'fidx' to 'prxy'. A label 'T.808\_FI.1' is at the bottom right.
+
+Figure I.1 – Part of an example JPEG 2000 file containing JPIP index boxes
+
+## I.2 Identifying the use of JPIP index boxes in the JPEG 2000 file format compatibility list
+
+Files that contain one or more of the index boxes defined in this Recommendation | International Standard may contain a CL<sup>1</sup> field in the File Type box (as defined in Rec. ITU-T T.800 | ISO/IEC 15444-1) with the value 'jpip' (0x6a70 6970).
+
+## I.3 Defined boxes
+
+### I.3.1 General
+
+Table I.1 lists all boxes defined as part of this Recommendation | International Standard. For the placement of and restrictions on each box, see the relevant subclause defining that box.
+
+Table I.1 is informative. Normative definitions of each box are contained within the individual subclauses referenced in the table.
+
+Table I.1 – Defined boxes (Informative)
+
+| Box name                                    | Type                 | e   | Comments                                                                                                                                                                        |
+|---------------------------------------------|----------------------|-----|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Codestream index box (I.3.2)                | 'cidx' (0x6369 6478) | Yes | This box contains indexing information about a JPEG 2000 codestream.                                                                                                            |
+| Codestream Finder box (I.3.2.2)             | 'cptr' (0x6370 7472) | No  | This box points to a JPEG 2000 codestream.                                                                                                                                      |
+| Header Index Table box (I.3.2.4.3)          | 'mhix' (0x6D68 6978) | No  | This box specifies an index of the marker segments in the main header of a codestream or the tile-part headers of a tile.                                                       |
+| Tile-part Index Table box (I.3.2.4.4)       | 'tpix' (0x7470 6978) | Yes | This box specifies the locations and lengths of each tile-part in the codestream.                                                                                               |
+| Tile Header Index Table box (I.3.2.4.5)     | 'thix' (0x7468 6978) | Yes | This box specifies the locations and lengths of each part of the codestream necessary to construct tile headers for each tile for the correct decoding of precinct packet data. |
+| Precinct Packet Index Table box (I.3.2.4.6) | 'ppix' (0x7070 6978) | Yes | This box specifies the locations and lengths of packets within the codestream.                                                                                                  |
+| Packet Header Index Table box (I.3.2.4.7)   | 'phix' (0x7068 6978) | Yes | This box specifies the locations and lengths of packet headers within the codestream.                                                                                           |
+| Manifest box (I.3.2.3)                      | 'manf' (0x6D61 6E66) | No  | This box summarizes the boxes that immediately and contiguously follow it, within its containing box or file at the same level as the Manifest box.                             |
+| Fragment Array Index box (I.3.2.4.2)        | 'faix' (0x6661 6978) | No  | This box specifies the locations and lengths of the elements of a codestream.                                                                                                   |
+| File Index box (I.3.3)                      | 'fidx' (0x6669 6478) | Yes | This box can be used to find other indexes and arbitrary data within the file                                                                                                   |
+| File Finder box (I.3.3.2)                   | 'fptr' (0x6670 7472) | No  | This box points to an indexed box                                                                                                                                               |
+| Proxy box (I.3.3.3)                         | 'prxy' (0x7072 7879) | No  | This box represents in a File Index box a box elsewhere in the file                                                                                                             |
+| Index Finder box (I.3.4)                    | 'iptr' (0x6970 7472) | No  | This box points to the root File Index box of a file.                                                                                                                           |
+
+I.3.2 Codestream Index box (superbox)
+
+I.3.2.1 General
+
+The Codestream Index box contains indexing information about a JPEG 2000 codestream. The type of a Codestream Index box shall be 'cidx' (0x6369 6478). The contents of a Codestream Index box shall be as follows (Figure I.2):
+
+![Diagram showing the organization of a Codestream Index box. It consists of a box labeled 'cptr' followed by a box labeled 'manf' with diagonal hatching, and then three dots indicating further content. Below the diagram is the label 'T.808_FI.2'.](09036266c6dba47efb2613ceaebe2b19_img.jpg)
+
+T.808\_FI.2
+
+Diagram showing the organization of a Codestream Index box. It consists of a box labeled 'cptr' followed by a box labeled 'manf' with diagonal hatching, and then three dots indicating further content. Below the diagram is the label 'T.808\_FI.2'.
+
+Figure I.2 – Organization of the contents of a Codestream Index box
+
+- cptr:** Codestream Finder box. This box points to the codestream indexed by the Codestream Index box. Its structure is specified in I.3.2.2.
+- manf:** Manifest box. This box summarizes the index tables following it inside the Codestream Index box. Its structure is specified in I.3.2.3.
+
+I.3.2.2 Codestream Finder box
+
+The Codestream Finder box points to a JPEG 2000 codestream. The type of a Codestream Finder box shall be 'cptr' (0x6370 7472). The contents of a Codestream Finder box shall be as follows (Figure I.3):
+
+![Diagram showing the organization of the contents of a Codestream Finder box. It consists of four fields: DR (Data Reference), CONT (Container Type), COEF (Codestream Offset), and CLEN (Codestream Length). Each field is represented by a rectangle with its name inside. The fields are arranged horizontally. To the right of the diagram is the label T.808_Fl.3.](ffe0fef452a0ae9a20253c319c54e13c_img.jpg)
+
+T.808\_Fl.3
+
+Diagram showing the organization of the contents of a Codestream Finder box. It consists of four fields: DR (Data Reference), CONT (Container Type), COEF (Codestream Offset), and CLEN (Codestream Length). Each field is represented by a rectangle with its name inside. The fields are arranged horizontally. To the right of the diagram is the label T.808\_Fl.3.
+
+Figure I.3 – Organization of the contents of a Codestream Finder box
+
+- DR:** Data Reference. This field specifies the location of the codestream, or of the Fragment Table box standing for it. If 0, the codestream or its Fragment Table box exists in the current file. Otherwise, the quantity identifies an entry in the Data Reference box in the current file. In this case, the Data Reference entry identified by DR indicates the resource that contains the codestream or Fragment Table box. This field is stored as a 2-byte big endian unsigned integer.
+- CONT:** Container Type. This field is stored as a 2-byte big endian unsigned integer. The values defined in this Recommendation | International Standard are described in Table I.2.
+- COFF:** Codestream Offset. This field specifies the location of the codestream or Fragment List box, as appropriate, relative to the start of the file or resource identified by DR. This field is stored as an 8-byte big endian unsigned integer.
+- CLEN:** Codestream Length. This field specifies the length of the codestream or Fragment List box, as appropriate. This field is stored as an 8-byte big endian unsigned integer.
+
+Table I.2 – Container type values
+
+| CONT             | Meaning                                                                                                                                                                                                                                                                                                                                                                                                                        |
+|------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| 0                | The entire codestream appears as a contiguous range of bytes within its file or resource. In this case, the offset and length values given here refer to the codestream itself. Note that the codestream might well be within a Contiguous Codestream box, but the offset and length values refer to the codestream itself, starting at the SOC marker and ending immediately after the EOC marker.                            |
+| 1                | The codestream is fragmented and the location and length values refer to the Fragment List box (including its box header) describing the locations and lengths of each of the fragments that represent the codestream. Note that all subsequent locations and lengths are expressed relative to the start of the codestream, as it would appear after reconstituting all of the fragments identified in the Fragment List box. |
+| All other values | Reserved for ISO use.                                                                                                                                                                                                                                                                                                                                                                                                          |
+
+I.3.2.3 Manifest box
+
+The Manifest box summarizes the boxes that immediately and contiguously follow it, within its containing box or file at the same level as the Manifest box.
+
+NOTE – The Manifest box can be used to facilitate random access into these following boxes, such as the index boxes following it inside a Codestream Index box.
+
+The type of a Manifest box shall be 'manf' (0x6D61 6E66). The contents of the Manifest box shall be as follows (Figure I.4):
+
+![Diagram showing the organization of the contents of a Manifest box. It consists of a sequence of Box Headers (BH) labeled BH^0, BH^1, ..., BH^{N-1}. Each box header is represented by a rectangle with its label inside. The box headers are arranged horizontally. To the right of the diagram is the label T.808_Fl.4.](404924fde6a708196214ae2da3819428_img.jpg)
+
+T.808\_Fl.4
+
+Diagram showing the organization of the contents of a Manifest box. It consists of a sequence of Box Headers (BH) labeled BH^0, BH^1, ..., BH^{N-1}. Each box header is represented by a rectangle with its label inside. The box headers are arranged horizontally. To the right of the diagram is the label T.808\_Fl.4.
+
+Figure I.4 – Organization of the contents of a Manifest box
+
+- BH<sup>i</sup>:** Box Header. This field contains the complete box header of the *i*-th box immediately following the Manifest box. The length of this field is 16 bytes if the value of the LBox field contained within that box header is 1, or 8 bytes otherwise.
+
+The number of boxes, *N*, whose headers are contained within the Manifest box, is determined by the length of the Manifest box. When used inside a Precinct Packet Index Table box or a Packet Header Index Table box, *N* is the number of codestream components.
+
+Inside a Codestream Index box, a Tile Header Index Table box, a Precinct Packet Index Table box or a Packet Header Index Table box, a Manifest box shall include all of the boxes that follow it, up to the end of the containing box.
+
+### I.3.2.4 Index tables
+
+#### I.3.2.4.1 General
+
+The Codestream Index box may contain an index table for each of the following kinds of codestream data: main header, tile-parts, tile headers, (precinct) packets and packet headers. Each index table is a different type of box. There shall be no more than one of each kind of table in a Codestream Index box.
+
+The Tile-part Index Table, Precinct Packet Index Table and Packet Header Index Table boxes are superboxes containing Fragment Array Index boxes. The Tile Header Index Table box is a superbox containing Header Index Table boxes. Below we define first the Fragment Array Index box and then the Index Table boxes.
+
+#### I.3.2.4.2 Fragment Array Index Box
+
+The Fragment Array Index box lists the locations and lengths of the elements of a codestream. It is used within the Tile-part Index Table, Precinct Packet Index Table and Packet Header Index Table superboxes.
+
+The type of a Fragment Array Index box shall be 'faix' (0x6661 6978). The contents of the Fragment Array Index box shall be as follows (Figure I.5):
+
+![Diagram illustrating the organization of the contents of a Fragment Array Index box. The box structure starts with single-byte or multi-byte fields: V, NMAX, and M. Following these are rows of data. Row 0 contains a sequence of triplets: (OFF^{0,0}, LEN^{0,0}, AUX^{0,0}) through (OFF^{0,NMAX-1}, LEN^{0,NMAX-1}, AUX^{0,NMAX-1}). A blue arrow indicates the sequence continues through subsequent rows until the final row M-1, which contains triplets (OFF^{M-1,0}, LEN^{M-1,0}, AUX^{M-1,0}) through (OFF^{M-1,NMAX-1}, LEN^{M-1,NMAX-1}, AUX^{M-1,NMAX-1}). The diagram is labeled T.808_FI.5.](c78f017dab5586c098c5d7c6a8f1d432_img.jpg)
+
+Diagram illustrating the organization of the contents of a Fragment Array Index box. The box structure starts with single-byte or multi-byte fields: V, NMAX, and M. Following these are rows of data. Row 0 contains a sequence of triplets: (OFF^{0,0}, LEN^{0,0}, AUX^{0,0}) through (OFF^{0,NMAX-1}, LEN^{0,NMAX-1}, AUX^{0,NMAX-1}). A blue arrow indicates the sequence continues through subsequent rows until the final row M-1, which contains triplets (OFF^{M-1,0}, LEN^{M-1,0}, AUX^{M-1,0}) through (OFF^{M-1,NMAX-1}, LEN^{M-1,NMAX-1}, AUX^{M-1,NMAX-1}). The diagram is labeled T.808\_FI.5.
+
+**Figure I.5 – Organization of the contents of a Fragment Array Index box**
+
+- V:** Version. This field is encoded as a 1-byte unsigned integer. The values defined in this Recommendation | International Standard are described in Table I.3.
+- NMAX:** Maximum number of valid elements in any row of the array. When used inside a codestream index table, NMAX is the maximum number of elements that will be specified for any tiles.
+- M:** Number of rows of the array. When used inside a codestream index table, M is the number of tiles.
+- OFF<sup>i,j</sup>:** Offset. This field specifies the offset in bytes (relative to the start of the codestream) of the  $j$ -th element in row  $i$  of the array.
+- LEN<sup>i,j</sup>:** Length. This field specifies the length in bytes of the  $j$ -th element in row  $i$  of the array.
+- AUX<sup>i,j</sup>:** Auxiliary. This field specifies auxiliary information about the  $j$ -th element in row  $i$  of the array. The value of this field shall be zero unless otherwise permitted by the superbox containing this box. All nonzero values of this field are reserved.
+
+While all rows of the array specified in the Fragment Array Index box shall be stored with NMAX number of elements, the object being described by that row might have a smaller number of elements to specify. In this case, where for any row  $i$  containing  $J$  valid elements where  $J$  is less than NMAX, the values of OFF<sup>i,J</sup> to OFF<sup>i,NMAX-1</sup> and LEN<sup>i,J</sup> to LEN<sup>i,NMAX-1</sup> shall be set to zero.
+
+Table I.3 – Version values
+
+| CONT             | Meaning                                                                                                                                                                                                   |
+|------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| 0                | NMAX, M and all OFF <sup>i,j</sup> and LEN <sup>i,j</sup> fields are encoded as 4-byte big endian unsigned integers and AUX <sup>i,j</sup> fields are not present.                                        |
+| 1                | NMAX, M and all OFF <sup>i,j</sup> and LEN <sup>i,j</sup> fields are encoded as 8-byte big endian unsigned integers and AUX <sup>i,j</sup> fields are not present.                                        |
+| 2                | All fields other than V are encoded as 4-byte big endian unsigned integers.                                                                                                                               |
+| 3                | NMAX, M and all OFF <sup>i,j</sup> and LEN <sup>i,j</sup> fields are encoded as 8-byte big endian unsigned integers and all AUX <sup>i,j</sup> fields are encoded as 4-byte big endian unsigned integers. |
+| All other values | Reserved for ISO use.                                                                                                                                                                                     |
+
+I.3.2.4.3 Header Index Table Box
+
+The Header Index Table box indexes the main header of a codestream or the tile-part headers of a tile, indicating the total main header length or first tile-part length and the locations and lengths of marker segments in the header. All marker segments shall be included, except that the SOT marker segment may be omitted for tile-part headers that consist of only SOT and SOD. Marker segments need not be listed in the order in which they occur in the codestream. The Header Index Table box can only occur inside a Codestream Index box. At the top level, it indexes a codestream and shall occur no more than once. Inside a Tile Header Index Table box, it indexes tile-part headers.
+
+NOTE – The intent is to provide an efficient means for skipping over pointer information in the header, which is not required for efficiently browsing the file but might unnecessarily bulk out the header. Listing multiple marker segments with the same marker code contiguously in the Header Index Table box will allow readers to skip over groups of marker segments in which they are not interested.
+
+The type of a Header Index Table box shall be 'mhix' (0x6D68 6978). The contents of the Header Index Table box shall be as follows (Figure I.6):
+
+![Diagram showing the organization of the contents of a Header Index Table box. It consists of a sequence of fields: TLEN, M^0, NR^0, OFF^0, LEN^0, followed by a dashed box containing M^{N-1}, NR^{N-1}, OFF^0, and LEN^{N-1}. The label T.808_FI.6 is at the bottom right.](df935fc9efbd024af4ba77e46bb0bb19_img.jpg)
+
+The diagram illustrates the structure of a Header Index Table box. It shows a sequence of fields: TLEN, M<sup>0</sup>, NR<sup>0</sup>, OFF<sup>0</sup>, and LEN<sup>0</sup>. These are followed by a dashed box representing a list of N-1 marker segments. Each segment in the list contains fields M<sup>N-1</sup>, NR<sup>N-1</sup>, OFF<sup>0</sup>, and LEN<sup>N-1</sup>. The label T.808\_FI.6 is located at the bottom right of the diagram.
+
+Diagram showing the organization of the contents of a Header Index Table box. It consists of a sequence of fields: TLEN, M^0, NR^0, OFF^0, LEN^0, followed by a dashed box containing M^{N-1}, NR^{N-1}, OFF^0, and LEN^{N-1}. The label T.808\_FI.6 is at the bottom right.
+
+Figure I.6 – Organization of the contents of a Header Index Table box
+
+- TLEN:** Length. When the Header Index Table box indexes a main header, this field specifies the total length of the main header. When the Header Index Table box indexes tile-part headers, this field specifies the total length of the first tile-part header. The value of this field is encoded as an 8-byte big endian unsigned integer.
+- M<sup>i</sup>:** Marker code. This field specifies the marker code beginning the *i*-th marker segment listed in this box. The value of this field is encoded as a 2-byte big endian unsigned integer.
+- NR<sup>i</sup>:** Number remaining. This field indicates that (at least) NR<sup>i</sup> marker segments with the same marker code M<sup>i</sup> are listed immediately and contiguously following the *i*-th marker segment in this list. The value of this field is encoded as a 2-byte big endian unsigned integer.
+- OFF<sup>i</sup>:** Offset. This field specifies the offset in bytes, relative to the start of the codestream, of the marker segment parameters (including the length parameter but not the marker itself) for the *i*-th marker segment in this list. The value of this field is encoded as an 8-byte big endian unsigned integer.
+- LEN<sup>i</sup>:** Length. This field specifies the length in bytes of the marker segment parameters (including the two bytes of the length parameter but not the two bytes of the marker itself) for the *i*-th marker segment in this list. The value of this field is encoded as a 2-byte big endian unsigned integer, and is the same as the value of the length parameter in the marker segment itself.
+
+The number of marker segments, *N*, listed in the Header Index Table box, is determined by the length of the Header Index Table box.
+
+I.3.2.4.4 Tile-part Index Table box (superbox)
+
+The Tile-part Index Table box indexes the locations and lengths of each tile-part in the codestream, where each tile-part commences with its SOT marker and finishes with the last packet of the tile-part.
+
+The type of a Tile-part Index Table box shall be 'tpix' (0x7470 6978). The contents of the Tile-part Index Table box shall be as follows (Figure I.7):
+
+![Diagram of a Tile-part Index Table box (faix). It is a single rectangular box with diagonal hatching and the label 'faix' inside. To its right is the label 'T.808_FI.7'.](48adb97a6a4a14b039450192f25cc1e0_img.jpg)
+
+Diagram of a Tile-part Index Table box (faix). It is a single rectangular box with diagonal hatching and the label 'faix' inside. To its right is the label 'T.808\_FI.7'.
+
+**Figure I.7 – Organization of the contents of a Tile-part Index Table box**
+
+**faix:** Fragment Array Index box. This box lists the locations and lengths of all the tile-parts in the codestream. Its structure is specified in I.3.2.4.2. The  $m$ -th row in this table corresponds to the  $m$ -th tile in the codestream. The entries on this row hold the locations and lengths of all the tile-parts in the corresponding tile, in codestream order. If the Fragment Array Index box has Version equal to 2 or 3, the Auxiliary fields specify for each tile-part the smallest  $n$  such that, in all components for which  $(N_L - n)$  is non-negative, resolution level  $(N_L - n)$  and all lower resolution levels have been completed when this tile-part is combined with all preceding tile-parts of the same tile, where  $N_L$  is the number of decomposition levels, which can vary by component. If no resolution levels of any component have been completed, the value of the Auxiliary field is one plus the maximum value of  $N_L$  across all components. The value zero is reached when all resolutions in all components have been completed. Because resolutions do not necessarily appear in order in a tile, some resolution levels above the value signalled by the Auxiliary field might have been completed.
+
+#### I.3.2.4.5 Tile Header Index Table box (superbox)
+
+The Tile Header Index Table box indexes the tile headers of each tile, for the correct decoding of precinct packet data.
+
+The type of a Tile Header Index Table box shall be 'thix' (0x7468 6978). The contents of the Tile Header Index Table box shall be as follows (Figure I.8):
+
+![Diagram of a Tile Header Index Table box. It consists of three adjacent rectangular boxes with diagonal hatching. The first box is labeled 'manf', the second 'mhix^0', and the third 'mhix^{N-1}'. To the right of the boxes is the label 'T.808_FI.8'.](e35f25e0b66752d4179a4cb108a3fb5a_img.jpg)
+
+Diagram of a Tile Header Index Table box. It consists of three adjacent rectangular boxes with diagonal hatching. The first box is labeled 'manf', the second 'mhix^0', and the third 'mhix^{N-1}'. To the right of the boxes is the label 'T.808\_FI.8'.
+
+**Figure I.8 – Organization of the contents of a Tile Header Index Table box**
+
+The number of Header Index Table boxes,  $N$ , is the number of tiles.
+
+**manf:** Manifest box. This box summarizes the boxes specified by  $\text{mhix}^i$  inside this Tile Header Index Table box. Its structure is specified in I.3.2.3.
+
+**$\text{mhix}^i$ :** Header Index Table box. This box indexes the tile-part headers for the  $i$ -th tile. Its structure is specified in I.3.2.4.3.
+
+#### I.3.2.4.6 Precinct Packet Index Table box (superbox)
+
+The Precinct Packet Index Table box indexes the packets within the codestream. The type of a Precinct Packet Index Table box shall be 'ppix' (0x7070 6978). The contents of the Precinct Packet Index Table box shall be as follows (Figure I.9):
+
+![Diagram of a Precinct Packet Index Table box. It consists of three adjacent rectangular boxes with diagonal hatching. The first box is labeled 'manf', the second 'faix^0', and the third 'faix^{N-1}'. To the right of the boxes is the label 'T.808_FI.9'.](36893f120533bae3be68e122656b1708_img.jpg)
+
+Diagram of a Precinct Packet Index Table box. It consists of three adjacent rectangular boxes with diagonal hatching. The first box is labeled 'manf', the second 'faix^0', and the third 'faix^{N-1}'. To the right of the boxes is the label 'T.808\_FI.9'.
+
+**Figure I.9 – Organization of the contents of a Precinct Packet Index Table box**
+
+The number of Fragment Array Index boxes,  $N$ , shall be no greater than the number of codestream components.
+
+**manf:** Manifest box. This box summarizes the boxes specified by  $\text{faix}^i$  inside this Precinct Packet Index Table box. Its structure is specified in I.3.2.3.
+
+**$\text{faix}^i$ :** The  $i$ -th Fragment Array Index box corresponds to the  $i$ -th image component in the codestream. The  $m$ -th row in this table corresponds to the  $m$ -th tile in the codestream. The entries on this row hold the locations and lengths of all packets in the corresponding tile-component. Packets appear contiguously, ascending in layer order, within their respective precincts, and precincts appear in the order associated with the sequence number  $s$ , defined in A.3.2.1. However, the fixed order of the packets is not necessarily the same as that specified in any COD/POC marker segments within the codestream. The structure of the Fragment Array Index box is specified in I.3.2.4.2.
+
+If packet headers are packed into PPM or PPT marker segments, the corresponding entries in the fragment array refer to the location and length of the packet body only, as it appears inside its tile-part body. Entries that refer to non-existent packets (either because the relevant tile-component contains fewer packets than another tile-component in the same array, or because the codestream has been truncated prior to the point at which that packet would have existed) should have their location field set to zero. Entries that refer to packets whose body is empty and whose header consists of exactly one byte, 0x80, may be identified using a length value of zero. Such packets occur frequently in JPEG 2000 codestreams; applications can avoid the overhead of explicitly fetching such packets whose content is predictable. If the relevant COD marker segment specifies that EPH markers are to appear after each packet header in some tile, the special length value of zero shall be interpreted in that tile as meaning that the packet consists of the 0x80 byte followed by the EPH marker.
+
+### I.3.2.4.7 Packet Header Index Table box (superbox)
+
+The Packet Header Index Table box indexes the packet headers within the codestream. The type of a Packet Header Index Table box shall be 'phix' (0x7068 6978). The contents of the Packet Header Index Table box shall be as follows (Figure I.10):
+
+![Diagram of Packet Header Index Table box structure showing three contiguous boxes: manf, faix^0, and faix^{N-1}.](51167ecef86d85cdc6dde05a3afb74b8_img.jpg)
+
+T.808\_FI.10
+
+Diagram of Packet Header Index Table box structure showing three contiguous boxes: manf, faix^0, and faix^{N-1}.
+
+**Figure I.10 – Organization of the contents of a Packet Header Index Table box**
+
+The number of Fragment Array Index boxes, *N*, shall be no greater than the number of codestream components.
+
+- manf:** Manifest box. This box summarizes the boxes specified by  $faix^i$  inside this Packet Header Index Table box. Its structure is specified in I.3.2.3.
+- $faix^i$ :** The *i*-th Fragment Array Index box corresponds to the *i*-th image component in the codestream. The *m*-th row in this table corresponds to the *m*-th tile in the codestream. The entries on this row hold the locations and lengths of all packet headers in the corresponding tile-component. Packet headers appear contiguously, ascending in layer order, within their respective precincts, and precincts appear in the order associated with the sequence number *s*, defined in A.3.2.1. However, the fixed order of the packet headers is not necessarily the same as that specified in any COD/POC marker segments within the codestream. The structure of the Fragment Array Index box is specified in I.3.2.4.2.
+
+Entries that refer to non-existent packet headers (either because the relevant tile-component contains fewer packets than another tile-component in the same array, or because the codestream has been truncated prior to the point at which that packet header would have existed) should have their location field set to zero. Entries that refer to packets whose body is empty and whose header consists of exactly one byte, 0x80, may be identified using a length value of zero. Such packets occur frequently in JPEG 2000 codestreams; applications can avoid the overhead of explicitly fetching such packets whose content is predictable. If the relevant COD marker segment specifies that EPH markers are to appear after each packet header in some tile, the special length value of 0 shall be interpreted in that tile as meaning that the packet consists of the 0x80 byte followed by the EPH marker.
+
+### I.3.3 File Index box (superbox)
+
+#### I.3.3.1 General
+
+The File Index box can be used to find other indexes (in particular, the codestream index corresponding to a codestream) and arbitrary data within the file.
+
+A root File Index box indexes the top level of the file. Any other File Index box indexes a superbox within the file. There shall be at most one File Index box with a given scope (top level or a particular superbox) within a given file.
+
+The type of a File Index box shall be 'fidx' (0x6669 6478). The contents of the File index box shall be as follows (Figure I.11):
+
+![Diagram of File Index box structure showing three contiguous boxes: fptr, prxy^0, and prxy^{N-1}.](ed99c577aacc48b3e3ef5060d0048041_img.jpg)
+
+T.808\_FI.11
+
+Diagram of File Index box structure showing three contiguous boxes: fptr, prxy^0, and prxy^{N-1}.
+
+**Figure I.11 – Organization of the contents of a File Index box**
+
+- fptr:** File Finder box. A root File Index box shall not include this box. Any other File Index box shall include this box, which shall point to the superbox indexed by the File Index box. The structure of the File Finder box is defined in I.3.3.2.
+- prxy<sup>i</sup>:** Proxy box. This box represents a box in the portion of the file indexed by the File Index box. A root File Index box shall include proxies only for boxes at the top-level of the file. Any other File Index box shall include proxies only for boxes at the top level of the superbox indexed by the File Index box. The proxies shall occur in the same order as the boxes, but not all boxes need be proxied. The structure of the Proxy box is defined in I.3.3.3.
+
+NOTE – Because in some cases the presence, absence, or ordering of boxes in the file is significant, it might be helpful to applications if, preceding any such proxied boxes, no boxes within the scope of the index are omitted from the index.
+
+### I.3.3.2 File Finder box
+
+The File Finder box points to a box. The type of a File Finder box shall be 'fptr' (0x6670 7472). The contents of a File Finder box shall be as follows (Figure I.12):
+
+![Figure I.12: Organization of the contents of a File Finder box. The diagram shows a rectangular box divided into two sections. The left section is labeled 'OOFF' and is divided into four equal-width segments by vertical lines. The right section is labeled 'OBH' and is filled with diagonal hatching. To the right of the diagram is the label 'T.808_FI.12'.](a320e67b369bfde4a5fa360b100da55c_img.jpg)
+
+Figure I.12: Organization of the contents of a File Finder box. The diagram shows a rectangular box divided into two sections. The left section is labeled 'OOFF' and is divided into four equal-width segments by vertical lines. The right section is labeled 'OBH' and is filled with diagonal hatching. To the right of the diagram is the label 'T.808\_FI.12'.
+
+**Figure I.12 – Organization of the contents of a File Finder box**
+
+- OOFF:** Original Offset. This field specifies the offset in bytes (relative to the start of the file) of the box pointed to by this File Finder box. The value of this field is encoded as an 8-byte big endian unsigned integer.
+- OBH:** Original Box Header. This field contains the complete box header of the box pointed to by this File Finder box. The length of this field is 16 bytes if the value of the LBox field contained within that box header is 1, or 8 bytes otherwise.
+
+### I.3.3.3 Proxy box
+
+The Proxy box represents in a File Index box a box elsewhere in the file, indicating its location and length, the location and length of any index to the box, and a prefix of the contents of the box.
+
+The type of a Proxy box shall be 'prxy' (0x7072 7879). The contents of the Proxy box shall be as follows (Figure I.13):
+
+![Figure I.13: Organization of the contents of a Proxy box. The diagram shows a long rectangular box divided into several sections. From left to right: 'OOFF' (divided into four segments), 'OBH' (hatched), 'N' (a small box), 'IOFF^0' (divided into four segments), 'IBH^0' (hatched), 'IOFF^{N-1}' (divided into four segments), 'IBH^{N-1}' (hatched), and 'PREF' (hatched). Dashed lines extend from the right side of the 'IOFF' and 'IBH' sections. To the right of the diagram is the label 'T.808_FI.13'.](f087d3f5d298b3b1634d13ff17879e41_img.jpg)
+
+Figure I.13: Organization of the contents of a Proxy box. The diagram shows a long rectangular box divided into several sections. From left to right: 'OOFF' (divided into four segments), 'OBH' (hatched), 'N' (a small box), 'IOFF^0' (divided into four segments), 'IBH^0' (hatched), 'IOFF^{N-1}' (divided into four segments), 'IBH^{N-1}' (hatched), and 'PREF' (hatched). Dashed lines extend from the right side of the 'IOFF' and 'IBH' sections. To the right of the diagram is the label 'T.808\_FI.13'.
+
+**Figure I.13 – Organization of the contents of a Proxy box**
+
+- OOFF:** Original Offset. This field specifies the offset in bytes (relative to the start of the file) of the box represented by this Proxy box. The value of this field is encoded as an 8-byte big endian unsigned integer.
+- OBH:** Original Box Header. This field contains the complete box header of the box represented by this Proxy box. The length of this field is 16 bytes if the value of the LBox field contained within that box header is 1, or 8 bytes otherwise.
+- NI:** Number of Indexes. This field indicates the number of index pointers included in this Proxy box. Each set of subsequent IOFF<sup>i</sup>, and IBH<sup>i</sup> fields points to either a File Index or a Codestream Index box that indexes the box represented by this Proxy box. All other values are reserved. The value of this field is encoded as a 1-byte unsigned integer.
+- IOFF<sup>i</sup>:** Index Offset. This field contains the offset in bytes (relative to the start of the file) of the *i*-th index box. The value of this field is encoded as an 8-byte big endian unsigned integer.
+- IBH<sup>i</sup>:** Index Box Header. This field contains the complete box header of the *i*-th index box. The length of this field is 16 bytes if the value of the LBox field contained within that box header is 1, or 8 bytes otherwise.
+- PREF:** Prefix. This field contains an arbitrary prefix of the data in the box represented by this Proxy box. It may have any length from zero up to the length of the content of the original box.
+
+I.3.4 Index Finder box
+
+The Index Finder box points to the root File Index box of a file. It shall occur only if the file contains a root File Index box. The type of an Index Finder box shall be 'iptr' (0x6970 7472). The contents of an Index Finder box shall be as follows (Figure I.14):
+
+![Diagram showing the organization of the contents of an Index Finder box. It consists of two fields: 'OFF' (Offset) and 'LEN' (Length). Each field is represented by a rectangle divided into four equal parts, indicating a 4-byte structure for each. The label 'T.808_FI.14' is positioned to the right of the diagram.](6a993bfdf2e00cfad01c4d2188a75d86_img.jpg)
+
+|     |     |
+|-----|-----|
+| OFF | LEN |
+|-----|-----|
+
+T.808\_FI.14
+
+Diagram showing the organization of the contents of an Index Finder box. It consists of two fields: 'OFF' (Offset) and 'LEN' (Length). Each field is represented by a rectangle divided into four equal parts, indicating a 4-byte structure for each. The label 'T.808\_FI.14' is positioned to the right of the diagram.
+
+Figure I.14 – Organization of the contents of an Index Finder box
+
+- OFF:** Offset. This field specifies the location of the root File Index box relative to the start of the file. This field is stored as an 8-byte big endian unsigned integer.
+- LEN:** Length. This field specifies the size of the root File Index box. This field is stored as an 8-byte big endian unsigned integer.
+
+I.4 Association of codestream indexes with codestreams
+
+In a JP2, JPX or JPM file, the Codestream Index box shall occur at the top level of the file and the *i*-th Codestream Index box shall correspond to the *i*-th codestream, also at the top level of the file. The Codestream Finder box within the Codestream Index box also indicates the codestream that is indexed by the Codestream Index box.
+
+I.5 Placement restrictions (informative)
+
+Few placement restrictions have been imposed on the boxes defined in this annex. They may be placed at the end of the file if desired; this is likely to be convenient when a non-indexed file is subsequently indexed. However, it might be helpful to place the Index Finder box near the beginning of the file, preferably immediately after any boxes that are required to be in a contiguous group at the beginning of the file (such as after the File Type box in a JP2 file or after the Reader Requirements box in a JPX file), where it can easily be found by file readers. To minimize the movement of file boxes, on the addition of this box and optionally the addition of a 'jpip' code to the compatibility list in the File Type box, a Free box (defined in Rec. ITU-T T.801 | ISO/IEC 15444-2) could be used as a placeholder for it in a yet-to-be-indexed file.
+
+## Annex J
+
+### Profiles and variants for interoperability and testing
+
+(This annex forms an integral part of this Recommendation | International Standard.)
+
+#### J.1 Introduction
+
+This annex provides the framework, concepts, and methodology for establishing interoperability, and the criteria to be achieved to claim compliance with this Recommendation | International Standard. This annex also provides a methodology for testing compliance within a set of defined profiles and variants. The objective of standardization in this field is to promote interoperability between JPIP servers and clients and to enable testing of these systems for compliance to this Specification.
+
+This annex also defines profiles and variants. Profiles define the fields that a JPIP server is expected to implement and support beyond parsing and interpretation; profiles also limit the requests a client can expect a server within this profile to support and fully implement. Clients making a request within a profile that receive a 501 ("Not Implemented", see Annex D) or 400 ("Bad Request") error code can use this as an indication that the server does not fully implement the profile and can fall back to requests of a lower profile. Variants define which features of the JPIP specification are used to request and transmit data between client and server. Profiles and variants are orthogonal to each other. Servers are classified according to the highest level profile they support, and all the variants they implement. Clients are classified according to all the variants they implement, and according to the highest level profile they can work with.
+
+Even though the testing procedures, profiles and variants compiled in this annex are defined for images encoded in only some parts of the Rec. ITU-T T.8xx | ISO/IEC 15444-x family of Recommendations | Standards, and only a limited subset of features of JPIP is tested, this shall not imply that servers or clients using means of JPIP to deliver images in other formats or by other means of JPIP not listed here are not compliant. It only means that their compliance is not defined within the limits of this annex, and that there is currently no recommended testing policy and classification for them.
+
+##### J.1.1 Profiles
+
+Profiles define which requests a server can be expected to support, and therefore, which requests a client can expect to be supported and fully implemented by the server. Requests defined in a lower profile are also supported and fully implemented in a higher profile. Profiles are defined in detail in J.3.
+
+##### J.1.2 Variants
+
+Variants define which means of the JPIP specification a client and a server use to transmit data. Clients and servers need to provide a common subset of variants in order to interoperate. Variants are defined in J.2.
+
+#### J.2 Definition of variants
+
+JPIP allows for three different image return types, for requests within a session or stateless communications and for the exchange of metadata and/or codestream data between the server and client. Variants classify clients and servers in a 3-dimensional space based on:
+
+- 1) the image return types they support;
+- 2) whether the client requires and the server implements a persistent cache model for requests within sessions and/or whether the communication is stateless (see B.1);
+- 3) whether the transmitted data includes codestreams and/or metadata encoded in the boxes of the file format.
+
+To classify a client or a server, the implemented variants in each of the three axes are specified. Interoperability of a client-server pair requires that both operate according to a common subset of variants. Unlike profiles that are ordered by complexity, variants do not form a hierarchy of features.
+
+##### J.2.1 Image return type variant (P, T or R)
+
+This parameter defines the image return type a server is able to deliver and a client is able to interpret. Servers in the **P** variant are able to deliver JPP streams; servers in the **T** variant are able to deliver JPT streams; servers in the **R** variant are able to deliver "raw" image return types. Clients in the **P** variant accept JPP streams, clients in the **T** variant accept JPT streams and clients in variant **R** accept raw images. The **P**, **T** and **R** variants are not mutually exclusive; servers or clients can support several variants.
+
+### J.2.2 State model variant (N or S)
+
+This parameter defines whether a server is able to use channels for communication. A server in variant **S** is able to grant a channel in response to a `New Channel` request (see C.3.3) and maintain a persistent cache model between requests in the channel. A server in variant **N** is able to respond to requests that do not involve a new channel or a channel ID request field.
+
+Clients operating in variant **S** are required to cache data between requests in the same session to iteratively request data from a server; for efficient ongoing communications, clients in variant **N** might need to use cache model manipulation requests. The **S** and **N** variants are not mutually exclusive, and servers and clients might support both variants.
+
+### J.2.3 Bitstream variant (M or C)
+
+This parameter defines the types of logical targets the server is able to serve. Servers operating in variant **M** are able to deliver original box contents of a JPEG 2000 file format as metadata-bins. Servers in variant **C** are able to deliver data contained in the codestream using the incremental codestream representation. A server in variant **C** shall deliver at least metadata-bin #0 (see A.3.6), though this bin will be empty for a logical target consisting of a codestream only. Clients in variant **C** accept at least incremental codestream representation of the image data; clients in variant **M** accept at least metadata-bins. The **M** and **C** variants are not mutually exclusive, and servers and clients might support both variants.
+
+Table J.1 provides a summary of the requirements of the variants.
+
+NOTE – Servers or clients might be in variant **M** only, in which case they can only return or accept metadata-bins, but no precinct or tile databins. This type of server might be useful to quickly scan for image metadata in a database of images. Clients in variant **M** only (and not in **C**) should include "meta:orig" in the *client-preferences* field to restrict responses to metadata-bins only. Clients in variant **C** only (and not in **M**) can use the "src-codestream-specs" of the "subtarget" field to indicate servers to construct logical targets consisting of codestreams only, see C.2.3.
+
+**Table J.1 – Defining requirements of variants**
+
+| Variant | Server requirements                                                                                                                                                                               | Client requirements                                                                                                     | Remarks                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
+|---------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| P       | Shall implement the image return type "jpp-stream"                                                                                                                                                | Shall be able to parse jpp-streams                                                                                      | P, T and R are not mutually exclusive. Clients and servers can implement several variants.                                                                                                                                                                                                                                                                                                                                                                                                                                         |
+| T       | Shall implement the image return type "jpt-stream"                                                                                                                                                | Shall be able to parse jpt streams                                                                                      |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
+| R       | Shall implement image return type "raw"                                                                                                                                                           | Shall be able to handle raw incoming data                                                                               |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
+| N       | Shall implement additive explicit cache model manipulation requests using byte counts fully in profile 1 and up.                                                                                  |                                                                                                                         | Variants N and S are not mutually exclusive and clients or servers can implement both.                                                                                                                                                                                                                                                                                                                                                                                                                                             |
+| S       | Shall implement <i>cnew</i> , <i>cclose</i> and <i>cid</i> fields fully. Shall implement a persistent cache model.                                                                                | Shall generate <i>cnew</i> field to establish sessions. Shall be able to cache data between multiple requests.          |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
+| C       | Shall be able to transmit image data in an incremental codestream representation. Shall implement the behaviour of <i>client-preferences</i> "meta:incr".                                         | Shall be able to parse an incremental codestream representation                                                         | Variants <b>M</b> and <b>C</b> are not mutually exclusive. A server or client can implement more than one variant at once. For the most efficient communications, servers should implement <b>C</b> in the first instance, supplemented by <b>M</b> . A server operating in <b>M</b> only (and not <b>C</b> ) might not be able to efficiently respond to view-window limiting requests apart from those which select codestreams.<br><br>Clients interested in retrieving image data should at least implement variant <b>C</b> . |
+| M       | Shall be able to transmit metadata and image data as boxes. Shall implement the <i>metareq</i> field in profile 1 and up. Shall implement the behaviour of <i>client-preferences</i> "meta:orig". | Shall be able to parse metadata-bins, including image data encoded as JPEG 2000 codestream boxes and placeholder boxes. |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
+
+### J.3 Definition of profiles
+
+Profiles define the set of request fields a server is expected to implement and support. An overview of the request fields per profile is given in Table J.2. Generally, higher profiles require the server to support more advanced technology of the
+
+standard. A client generating requests from a lower profile can expect responses satisfying the request from a server that belongs to an equal or higher profile.
+
+Profiles provide a mechanism for clients to adapt their requests to the capabilities of the server. For this to be successful, servers shall provide sufficient indication of their inability to satisfy a particular request within a profile. Upon discovering that a server is unable to serve a particular request within a profile, a reasonable strategy for a client would be to restrict future requests to those in a lower profile. The server can indicate its inability to satisfy a particular request as given by the client by either issuing an error return code or, where applicable, by modifying the request and issuing appropriate JPIP-response headers (see Annex D).
+
+J.3.1 Profile 0: "Basic Communication"
+
+This profile provides a mechanism for basic communication of a request by a client and a response by a server. Only basic operations on JPEG 2000 Part-1 codestreams or files are supported. This covers delivery of image regions or whole images fitting to a particular display window size. Cache manipulations are not allowed in the request stream for profile 0. The only fields the server is expected to support in profile 0 are:
+
+target, type, target id, frame size, region offset, region size, len, pref (with restrictions), (all variants)  
+cid, cnew, cclose (additionally, in variant S)
+
+The client is required to be able to parse the data returned by the server and is required to handle JPP, JPT or raw image return types according to their variant. Servers cannot be expected to honour the request for extended precinct or tile databins, i.e., the "ptype" or the "ttype" field defined in C.7.3, Table C.4. Conforming clients shall accept unaligned messages; servers shall not be required to honour the "align" request. The only client preference request pref that a server is required to satisfy within this profile is "concise", see C.10.2.8, and "fullwindow", see C.10.2.2. Servers in profile 0 variant S shall implement the fields cid, cnew and cclose, but only need to support a single channel per session.
+
+J.3.2 Profile 1: "Enhanced Communications"
+
+Profile 1 extends profile 0 by requiring that servers support cache model manipulation requests, and the request can be limited by layers or components. Depending on the profile variant, the cache model is either explicitly communicated to the server by cache model requests in variant N or implicitly expected to be implemented by the server in variant S. Profile 1 also extends Profile 0 to include the following additional fields:
+
+components, layers, wait, model (with restrictions, see text), (all variants)  
+metareq (additionally, in variant M)
+
+Profile 1 servers are also expected to handle additive cache model manipulation requests with explicit bin addressing and byte counts, i.e., the model field using explicit bin descriptors as defined in C.8.1.2. As in profile 0, servers in profile 1 variant S shall implement the cid, cnew, cclose fields, but only a single channel per session needs to be supported. Servers in profile 1 variant M shall additionally implement the metareq field.
+
+J.3.3 Full profile
+
+The full profile provides capabilities beyond all lower profiles up to everything specified in this Recommendation | International Standard.
+
+Table J.2 – Set of fields included in each profile
+
+| Profile              |           | 0:Basic Communications | 1:Enhanced Communications | Full profile |
+|----------------------|-----------|------------------------|---------------------------|--------------|
+| Server support field | target    | yes                    | yes                       | yes          |
+|                      | subtarget |                        |                           | yes          |
+|                      | fsiz      | yes                    | yes                       | yes          |
+|                      | roff      | yes                    | yes                       | yes          |
+|                      | rsiz      | yes                    | yes                       | yes          |
+|                      | comps     |                        | yes                       | yes          |
+|                      | layers    |                        | yes                       | yes          |
+|                      | len       | yes                    | yes                       | yes          |
+|                      | tid       | yes                    | yes                       | yes          |
+
+Table J.2 – Set of fields included in each profile
+
+| Profile                       |                         | 0:Basic Communications          | 1:Enhanced Communications               | Full profile |
+|-------------------------------|-------------------------|---------------------------------|-----------------------------------------|--------------|
+|                               | metareq                 |                                 | yes                                     | yes          |
+|                               | ptype=ext,<br>ttype=ext |                                 |                                         | yes          |
+|                               | align                   |                                 |                                         | yes          |
+| Multi-channel                 | cnew                    | yes (only one session)          | yes (only one per session)              | yes          |
+|                               | cid                     | yes (only one per session)      | yes (only one per session)              | yes          |
+|                               | cclose                  | yes                             | yes                                     | yes          |
+| Pre-emptive                   | wait                    |                                 | yes                                     | yes          |
+|                               | qid                     |                                 |                                         | yes          |
+|                               | stream                  |                                 |                                         | yes          |
+|                               | context                 |                                 |                                         | yes          |
+|                               | implicit model          |                                 |                                         | yes          |
+|                               | tpmodel                 |                                 |                                         | yes          |
+| Cache management              | mset                    |                                 |                                         | yes          |
+|                               | model                   |                                 | explicit, byte counts and additive only | All          |
+| Server Control Request fields | align                   |                                 |                                         | yes          |
+|                               | type                    | jpp-stream<br>jpt-stream<br>raw | jpp-stream<br>jpt-stream<br>raw         | All          |
+| Client Preferences            | pref                    | concise<br>fullwindow           | concise<br>fullwindow                   | All          |
+
+## J.4 Testing methodology
+
+JPIP interoperability testing is performed at databin level, i.e., on the data transmitted from server to client. This clause provides a set of Rec. ITU-T T.800 | ISO/IEC 15444-1 example images and example JPIP requests, along with corresponding example response headers and data from the server. The response data from the servers are in the form of jpp-files and jpt-files, as described in A.5.
+
+### J.4.1 Server conventions required for testing
+
+All example streams have been created with the *conciseness-pref* client preference set to "concise" and the *view-window-pref* set to "fullwindow". Resource constraints at the server might require a realistic server implementation to restrict requests that require too much data from the server at once. The example data provided with this clause should not trigger such conditions for implementations targeted to state-of-the-art desktop computers. If a server implementation includes means to restrict a request to limit resources below what is needed to perform the test, this type of processing needs to be disabled for the purpose of compliance testing. This clause does not introduce any resource bounds for the environment in which a server is expected to operate.
+
+### J.4.2 Server testing
+
+Server testing is specific to a given variant and profile combination. Testing a JPIP server is performed by initiating JPIP requests for data from an example image and comparing the data delivered by the server under testing with the example responses according to the variant and profile using the algorithm described in J.4.3. To claim compliance to a specific profile and variant, the server shall pass all server tests for this profile and all lower profiles using the specified variant.
+
+Although JPIP servers are allowed to modify what they deliver, the example streams shall not be modified by the server during testing.
+
+NOTE 1 – Example streams for the JPP image return type have been created in such a way that each precinct of the example stream consists of only one codeblock in each sub-band. Therefore, any transcoding is unnecessary, though insertion or removal of COM, PLT, PLM and TLM markers is allowed within the context of this testing procedure.
+
+For the purpose of testing, the JPIP data that the server would send over a network shall be saved in the appropriate jpp- or jpt-file format. Any wrapper such as HTTP response codes is excluded from these files.
+
+The EOR codes concluding the communication shall be included in the file. The contents of these files are then compared with the contents of the example responses. The response returned by a compliant server might, however, differ from the example response.
+
+Per the test procedure defined in J.4.3, the following differences with the example stream are allowed:
+
+- Reordering of the databins within the response.
+- Relocating the contents of metadata boxes into placeholder boxes.
+- Using equivalent encodings for the VBAS headers of the databins.
+- Using a different break-up of metadata into placeholder bins, provided that the requested metadata is included in the response.
+- Using stream-equivalent representations of metadata.
+
+A normative definition of which differences between the streams are acceptable is implicitly given by the test procedure in J.4.3.
+
+NOTE 2 – A test tool ("vbasdiff.py") is provided in an electronic attachment to this Recommendation | International Standard that can be downloaded from <https://handle.itu.int/11.1002/2000/7460> or <https://standards.iso.org/iso-iec/15444-9/ed-2/en> along with example test data. The tool implements this test procedure and analyses the difference between two server responses.
+
+NOTE 3 – Servers can additionally provide stream equivalent representations; however, determining their correctness is outside the scope of this annex; they are ignored by the testing methodology defined in J.4. Furthermore, testing for JPIP conformance when applied to data that requires other placeholder flag values, for example as used in Rec. ITU-T T.802 | ISO/IEC 15444-3, is outside the scope of this annex.
+
+### J.4.3 Comparing server responses
+
+This clause defines a normative algorithm that compares the response data of the server under testing with the example responses provided by this Recommendation | International Standard.
+
+Included with the test stream set is a python test script ("vbasdiff.py") to perform this comparison implementing the algorithm described in the following: The nature of the test depends on the existence of the length field. If a *len* field is present in the request, test only the size of the server response and the EOR code. Otherwise, perform the following four steps defined in detail later:
+
+- 1) Parse the messages in the jpp- or jpt-files, testing their encoding and assigning them to bins.
+- 2) Bring metadata-bins into canonical form as defined in J.4.3.3.
+- 3) Measure the amount of excess data.
+- 4) Compare the fraction of excess data to total data with a threshold.
+
+#### J.4.3.1 Comparing the size of the server response
+
+In case the request includes the *len* field, compare the length in bytes of the server response excluding any EOR message with the requested length. If the size in bytes of this output is larger than the requested length, the comparison fails. If no data except EOR was returned, the comparison fails. Then compare the EOR code of the tested stream with the EOR code of the example stream. If the EOR code of the tested stream is neither 1 ("Image Done") nor 2 ("Window Done", see Table D.2) nor equal to the EOR code of the example stream, the comparison fails. The EOR message body shall be ignored.
+
+NOTE – The example streams contain similar requests with and without the *len* field.
+
+#### J.4.3.2 Parsing stage
+
+For test requests that do not include the *len* field, test and example data are parsed. The VBAS message headers shall be decoded, first separating EOR messages from regular messages, and for regular messages, identifying the in-class identifier, the message class, the codestream sequence number (CSn), the "final message bit" (bit 4, labelled "c" in Figure A.3), the AUX value, if present, and the message offset and length. The message body shall then be inserted into databins according to the message offset and message length field of the message header, where each bin is identified by the triplet of bin class, in-class identifier and codestream sequence number. The mapping between message class and bin class is given by Table A.2. It shall be acceptable if a later message replaces parts of the data delivered by a former message, but it is not acceptable to deliver data that enlarges bins for which a final message has been received already.
+
+First, EOR codes are compared. If the EOR code of the tested stream is neither 1 ("Image Done") nor 2 ("Window Done", see Table D.2) nor equal to the EOR code of the example stream, the comparison fails. The EOR message body shall be ignored.
+
+AUX values need either to be included in all messages contributing to a databin, or to be included in none. Otherwise, the file is ill-formed and the comparison fails. For each databin containing messages with AUX-values, the following algorithm is used to assign an AUX value to the databin:
+
+- For precinct databins, the AUX value of the bin shall be the maximum of all AUX values found in all messages contributing to the bin.
+- For tile databins, the AUX value of the bin shall be the minimum of all AUX values found in all messages contributing to the bin.
+
+NOTE – Messages containing AUX values do not occur in testing for profile 0 and 1.
+
+#### J.4.3.3 Abstracting from the metadata-bin layout
+
+In the next step, metadata-bins are brought into a canonical form in order to abstract from the particular way a server broke up metadata into placeholders. The messages contributing to a databin might not define all of its data; it can happen that messages in the stream only define databins partially, and that it is acceptable that metadata-bins contain "holes" of missing data that have been relocated by the placeholder mechanism. Such regions are referred to as "missing bytes" in the following.
+
+The test script performs the following algorithm to reconstruct intermediate data from a jpp- or jpt-file:
+
+- Metadata-bin #0 is scanned in the test stream for incomplete box headers. Test and example streams are then made comparable by marking corresponding ranges as missing data in both streams. The modified streams are then checked for placeholder boxes. If the flags value of a placeholder box has its LSB set, indicating that the OrigID is valid, the placeholder box will be handled as indicated in the next steps; otherwise, it will remain in its unmodified form:
+  - If the databin referenced by the placeholder box is included in the stream, the box will be replaced by the box header and bin contents referenced within.
+  - If the databin referenced in the placeholder box is not included in the stream, the placeholder box will be removed, the box header in the placeholder box will be inserted into the stream, and the byte range in the missing target bin will be marked as missing data.
+- After metadata-bin #0 of test and example streams have been parsed as above, all remaining metadata-bins except bin #0 are removed from the stream.
+
+The above algorithm requires that the software performing the comparison contains a database describing which boxes are superboxes and which are plain boxes. This knowledge is required to be able to scan superbox contents correctly for placeholder boxes. In the test procedure, it is of advantage not to include excess data in the response. Servers should use placeholders as appropriate to avoid excess data. For profile 1 and above, every superbox has been replaced by a placeholder box in the example streams. Example streams for profiles 0 have been created without placeholder boxes and only the minimal amount of metadata, as defined in C.5, is present.
+
+#### J.4.3.4 Comparing databins
+
+In the third step, all remaining databins shall be compared, locating for each bin-class, bin-Id and CSn value in one stream the corresponding bin in the second stream: a metadata, tile or main header databin needs to be present in the test stream if and only if it is present in the example stream; otherwise, the comparison fails. An (extended or regular) precinct or tile databin needs to be present and non-empty in the test stream if it is present and non-empty in the example stream. An (extended or regular) precinct or tile databin either empty or non-present in the test stream needs also to be either empty or non-present in the example stream. If these conditions are not met, the comparison fails.
+
+NOTE – According to the clause above, it is equivalent not to transmit any message for a precinct or tile databin, or to create a message with no payload data. That is, even in concise mode JPIP servers have the freedom to signal tile or precinct databins that contain no significant image data by transmitting messages of length zero – and thus to potentially increase the size of the overall stream. By contrast, this freedom does not exist for main header, tile header or metadata bins. See A.3.6.1 for additional details about metadata bins.
+
+Databins are compared as follows:
+
+- If one of the databins carries AUX values, the other bin needs to carry AUX values. If both bins carry AUX values, they need to be equal. Otherwise, the comparison fails. See J.4.3.1 for information on how to compute the AUX value of a bin from the AUX values of the messages contributing to the bin.
+- If the example databin contains a message that indicates that the "last" byte of the bin has been included, the corresponding databin in the stream under testing needs also to contain a message with such an indicator. Otherwise, the comparison fails.
+- For all bin types except the main header databin and tile header databins, all defined bytes in the databins being compared need to compare equal. Otherwise, the comparison fails. The number of excess bytes in the test stream but not in the example stream is to be summed up.
+
+- The main header databin and tile header databins are compared by decomposing them into marker segments and comparing the marker segments independent of their order. All marker segments except COM, PLT, PLM and TLM need to compare equal.
+
+After comparing all databins, the amount of excess bytes  $N_e$  measured in step three above shall be divided by the total number of bytes in all bins  $N_t$ . If this quotient is above a threshold  $T$ , the comparison fails. For the example requests and example responses currently defined in this Recommendation | International Standard, the threshold  $T$  shall be zero.
+
+In order to test servers for compliance as defined in this annex, servers should operate in accordance with the *concise* clause of the *pref* field, see C.10.2.8. Servers that do not operate in this way might still be compliant to this Recommendation | International Standard, but their testing is beyond the scope of this annex.
+
+#### J.4.4 Client testing
+
+Client testing is specific to a given variant. Compliance of clients shall be tested by feeding a provided example response header and a jpp- or jpt-file for a particular variant and profile to the implementation under testing. The client then processes this response. For the purposes of testing, the clients shall create files or codestreams compliant to Rec. ITU-T T.800 | ISO/IEC 15444-1. This feature is not a mandatory requirement for a client to be compliant, but it is required to perform testing. The created codestream or file shall then be compared with the example codestream or file provided in this clause using the algorithm defined in the following. To claim compliance to variant, the client shall pass all client tests for the specified variant.
+
+Comparing the example streams with the streams generated by the client is performed in two stages: first comparing metadata if it is present, and second comparing image data when available.
+
+NOTE – The client testing procedure described here only tests the ability of clients to parse jpp or jpt streams successfully, and to regenerate a JPEG 2000 compliant file or codestream from such data. It does not test the ability of clients to create requests or exploit other capabilities offered by this Recommendation | International Standard.
+
+##### J.4.4.1 Comparing metadata
+
+If the target is encoded in a JPEG 2000 file format, the contents of the boxes of the example file and the contents of the boxes except for the codestream box(-es) generated by the test implementation are compared. The client is, however, allowed to perform the following modifications:
+
+- Include additional UUID boxes not present in the example stream.
+- Reorder the boxes, provided this does not change the semantics of the file.
+
+Exclusive of these modifications, the box contents of test and example streams need to be identical. Otherwise, the comparison fails.
+
+##### J.4.4.2 Comparing reconstructed image data
+
+If the request that was used to generate the example jpp- or jpt-file included a request-field for a non-empty view-window, the reconstructed image data shall be compared. The example stream and the codestream generated by the client implementation are both decoded with a conformant JPEG 2000 decoder. The same implementation shall be used for both streams. The resulting images need to be identical on a pixel by pixel basis within the view window of the request, or else the comparison fails. Comparison in this stage is to be performed as follows:
+
+- Set  $fx' = Xsiz - XOsiz$  and  $fy' = Ysiz - YOsiz$  where  $Xsiz, XOsiz$  and  $Ysiz, YOsiz$  are taken from the SIZ marker of the relevant codestream.
+- Set  $ox, oy$  and  $sx, sy$  to the region offset and region size of the view window that had been defined in the request, and set  $fx$  and  $fy$  to the frame size that had been defined in the request.
+- The region size  $sx'$  and  $sy'$ , and offset  $ox'$  and  $oy'$ , associated with the codestream image region are then determined by:
+
+$$\begin{aligned} ox' &= \left\lfloor ox \cdot \frac{fx'}{fx} \right\rfloor; & oy' &= \left\lfloor oy \cdot \frac{fy'}{fy} \right\rfloor; \\ sx' &= \left\lfloor (sx + ox) \cdot \frac{fx'}{fx} \right\rfloor - ox'; & sy' &= \left\lfloor (sy + oy) \cdot \frac{fy'}{fy} \right\rfloor - oy' \end{aligned} \quad (J-1)$$
+
+- Compare all pixels in the reconstructed images constrained to the view window having the left, top image corner  $ox'$  and  $oy'$  and having the dimensions  $sx'$  and  $sy'$ . All pixels within this region need to be identical; otherwise, the comparison fails.
+
+NOTE 1 – The above procedure is similar, but not identical to that defined in C-4, Equations C-1 and C-2. The difference is that the resolution level  $r$  in Equation C-1 is here constrained to be zero, enforcing the comparison at the full image resolution.
+
+NOTE 2 – A tool ("jp2file.py") is provided in the electronic attachment to Rec. ITU-T T.804 | ISO/IEC 15444-5 that generates a textual representation of the contents of JPEG 2000 files or codestreams. This tool can be used to ease the analysis of the data generated by the client. A tool with the same name ("jp2file.py") might also be found in the electronic attachment to this Recommendation | International Standard, but the tool in the electronic attachment to Rec. ITU-T T.804 | ISO/IEC 15444-5 should be preferred, to the extent that they differ.
+
+NOTE 3 – Although this entire client test procedure needs vendors to provide a JPEG 2000 conformant decoder implementation, this is not required for conformance to this Recommendation | International Standard. The ability of a client to create a JPEG 2000 file or codestream is also not required to be compliant to this Recommendation | International Standard, but is required only for performing the tests of this annex.
+
+## Annex K
+
+### Using JPIP with HTTP requests and UDP returns
+
+(This annex forms an integral part of this Recommendation | International Standard.)
+
+#### K.1 Introduction
+
+This annex provides details of the "http-udp" transport, which is identified in this text as HTTP-UDP. The HTTP-UDP transport uses the same mechanisms as the HTTP transport to send client requests to the server and receive the server's response headers and status codes. However, the server's response data are delivered as UDP datagrams over an auxiliary UDP connection, as defined in RFC 768. The information transported on this auxiliary UDP connection is identical to that which would have been transported as the entity body of a pure HTTP response, except that it is framed into chunks, each of which has a chunk sequence number and a record of the Request-id associated with the corresponding client request. Each chunk shall contain a whole number of JPIP messages and at most one EOR message as defined in Annex A. Message class identifiers and codestream sequence numbers shall be present in at least the first JPIP message of each data chunk.
+
+NOTE – Since the UDP transport is not reliable (i.e., UDP packets might be dropped or out of order) clients might not receive all data chunks corresponding to a request. Clients can use the Abandon request field to explicitly inform the server of this condition, see C.7.6.
+
+#### K.2 Client requests
+
+Requests are delivered on the primary channel exactly as HTTP requests. They have exactly the same form as requests issued over a channel that uses the HTTP transport described in Annex F. In particular, HTTP "GET" and "POST" requests may both be used. Client requests that are issued within an HTTP-UDP transported JPIP channel shall include the Request-id (qid) request field.
+
+Clients should issue requests with consecutive Request-id values.
+
+#### K.3 Response data delivery and channel establishment
+
+A new channel can be established to a JPIP server by issuing a request that includes the New Channel request field (see C.3.3). As an example, such a request might be issued using HTTP, although it might also be issued to a JPIP-specific server using any suitable transport mechanism. If the server's response (through the New Channel response header in D.2.3) indicates that a new channel has been created to work with the HTTP-UDP transport, the request which included the New Channel request field is treated as though it had been issued within the newly created HTTP-UDP transported channel. This ensures that the response data for that request and all subsequent requests in the same channel is framed into data chunks and delivered as UDP datagrams. This response data cannot be empty, since every request issued within an HTTP-UDP transported channel shall have a response data stream that consists of at least the EOR message (see D.3).
+
+The destination to which response datagrams are delivered depends upon whether or not the associated request contains a Sendto request field.
+
+- 1) For requests that contain a Sendto request field, the datagrams is delivered to the specified address without any explicit acknowledgement by the client.
+- 2) For requests that do not contain a Sendto request field, the response datagrams cannot be delivered until an auxiliary UDP connection has been established. To do this, the client sends one or more connection establishment datagrams to the server host identified via the New Channel response header, on the port identified by the New Channel response header. Each connection establishment datagram commences with a four byte header, which is followed by the channel-id string associated with the new HTTP-UDP channel. Once the server receives a connection establishment datagram with the correct channel-id string, it sends all subsequent response datagrams (other than those associated with Sendto request fields) to the IP address and port from which the channel establishment datagram arrived and it expects to receive acknowledgement datagrams from the same client IP address and port.
+
+NOTE – Since UDP is an unreliable transport, connection establishment datagrams might be lost. For this reason, clients might need to send multiple connection establishment datagrams, and servers might need to discard superfluous connection establishment datagrams which could arrive. Once a valid connection establishment datagram has been received, the server can choose to filter incoming datagrams as part of an overall defence strategy.
+
+The first two bytes of a connection establishment datagram's header shall be FF, while the third and fourth bytes identify the length of the channel-id string, recorded as a 16-bit big-endian quantity. The four byte header is followed by the channel-id string, encoded as UTF-8 characters. Additional content might be provided, beyond the end of the channel-id string, but the interpretation of such content is unspecified by this Recommendation | International Standard.
+
+K.4 Server responses
+
+In response to each client request, the server sends an HTTP reply paragraph back to the client over the primary channel. The reply paragraph contains the status code, reason phrase and all relevant JPIP response headers and any appropriate HTTP response headers. However, no response data is returned via the primary channel. For this reason, there shall be no HTTP entity body in an HTTP-UDP response. Neither shall the "Content-length:" or the "Transfer-encoding:" HTTP response headers be used.
+
+The response data itself are delivered via UDP, framed into chunks in the manner described in K.5. Since the HTTP-UDP transport can only be used with sessions, the image return type is constrained to JPP-stream and JPT-stream as defined in Annex A. Thus, the response data invariably consists of a sequence of JPP-stream or JPT-stream messages.
+
+The response data resulting from each request shall consist of a whole number of chunks, meaning that no chunk is permitted to contain response data generated in response to two different requests.
+
+The response to each and every request following the one in which the channel was requested, shall be terminated with an EOR message, even if the response data would otherwise have been empty. The EOR message is considered as part of the response data.
+
+This means that every request issued on an HTTP-UDP transported JPIP channel results in the generation of at least one non-empty response chunk from the server and that the last chunk generated in response to each request terminates with the EOR message.
+
+K.5 Framing of response data into chunks
+
+All response data sent by the server via the auxiliary UDP connection shall be framed into chunks. Each chunk consists of an 8-byte chunk header, followed by the chunk body that holds the server's response data, as shown in Figure K.1. The chunk header and body are sent as a single UDP datagram, whose length shall be exactly 8 plus the length of the chunk body measured in bytes. Moreover, no UDP datagram shall have a length larger than 4096 bytes or a length smaller than 8 bytes. The first 2-byte word of the chunk header holds an unsigned big-endian integer, whose interpretation as a "control" field is provided in Table K.1.
+
+The remaining 6 bytes of the chunk header contain the least significant 16 bits of the Request ID provided by the client in the request with which the chunk's response data is associated, together with a one-byte "repeat" field and a 24-bit chunk sequence number encoded as big-endian unsigned integer. The chunk sequence number is a number generated by the server, shall start at zero and shall be incremented by one for each subsequent chunk sent to the client in response to the same request.
+
+New requests from the client shall cause the chunk sequence numbering to be reset starting at 0 for the first chunk sent in response to the new request. Chunk sequence numbers do not wrap around, and servers shall indicate an error using the EOR reason code 7 (Response limit reached), see D.3 in the event of running out of available chunk sequence numbers.
+
+The one-byte "repeat" field can be used by the server in any manner desired. Typically, the "repeat" field would be used to distinguish between original and retransmitted versions of a data chunk, allowing the server to determine which instance of a chunk is being acknowledged within an acknowledgement datagram. However, the field can potentially be used in other ways. Clients should not attempt to interpret the "repeat" field but shall reproduce it within returned acknowledgement datagrams.
+
+NOTE – The Request ID and chunk sequence number allow for chunks of data to be properly reassembled in order. They also provide a means for dropped chunk detection. Clients can detect the loss of chunks by examining the set of chunk sequence numbers for gaps or by detecting that the server has not transmitted a chunk containing an EOR message; the latter will always be included in the last chunk sent in response to a request. Clients can use the Abandon request field to explicitly inform the server of missing chunks. Clients can choose to defer the use of these mechanisms or not to use them at all, at their discretion.
+
+![Diagram of response data structure on http-udp connection. It shows a rectangular frame divided into two main sections: 'Chunk header' and 'Chunk body'. The 'Chunk header' is further divided into four fields: 'Control', 'Request ID', 'repeat', and 'Chunk sequence number'. The 'Chunk body' is a large area with diagonal hatching. A bracket below the 'Request ID', 'repeat', and 'Chunk sequence number' fields is labeled 'Server specific'. A long double-headed arrow at the bottom spans the entire width of the frame and is labeled 'Chunk length (byte)'. The identifier 'T.808(22)_FK.1' is located at the bottom right of the diagram.](b9cfcba6591488c6a29a844db4f052eb_img.jpg)
+
+T.808(22)\_FK.1
+
+Diagram of response data structure on http-udp connection. It shows a rectangular frame divided into two main sections: 'Chunk header' and 'Chunk body'. The 'Chunk header' is further divided into four fields: 'Control', 'Request ID', 'repeat', and 'Chunk sequence number'. The 'Chunk body' is a large area with diagonal hatching. A bracket below the 'Request ID', 'repeat', and 'Chunk sequence number' fields is labeled 'Server specific'. A long double-headed arrow at the bottom spans the entire width of the frame and is labeled 'Chunk length (byte)'. The identifier 'T.808(22)\_FK.1' is located at the bottom right of the diagram.
+
+Figure K.1 – Response data structure on http-udp connection
+
+**Table K.1 – Interpretation of the "control" field in each data chunk header**
+
+| "control" field value | Interpretation in response chunk headers                                                                                                                                                                                                                                                                                                                                                                                                                                                                    | Interpretation in acknowledgement chunk headers                                                                                              |
+|-----------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------|
+| 0000 xxxx DDDD DDDD   | Maximum time that the server would prefer the client to wait from the time it receives this data chunk before acknowledging the chunk's arrival in an acknowledgement datagram for the first time is given by $2^{(D/8)}$ microseconds, where D is the unsigned integer represented by the second byte of the control field. This interpretation does not apply if the corresponding request included a Sendto request field with the value "no".                                                           | Estimated time between client receipt of the data chunk and delivery of the acknowledgement datagram, expressed as $2^{(D/8)}$ microseconds. |
+| 0000 AAAA xxxx xxxx   | Acknowledgement repetitions A, in the range 0 to 15. The server would prefer the client to acknowledge the arrival of this data chunk at least A+1 times, in A+1 separate acknowledgement datagrams. The server would prefer all A+1 acknowledgement datagrams to be sent within the time given by the D parameter, as defined above.<br><br>If the corresponding request included a Sendto request field, the value of A has no meaning, since the client sends no acknowledgement datagrams in that case. | Number of previous datagrams in which the client has already acknowledged the receipt of this data chunk.                                    |
+| 1111 1111 1111 1111   | Reserved for ITU/ISO use                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    | Connection establishment datagram                                                                                                            |
+| Other values          | Reserved for ITU/ISO use                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    | Reserved for ITU/ISO use                                                                                                                     |
+
+## K.6 Client acknowledgement of server responses
+
+For response datagrams issued in response to requests containing a Sendto request field, there is no explicit client acknowledgement, although servers might deduce the arrival or non-arrival of data chunks using information provided via Barrier and/or Abandon request fields in subsequent requests.
+
+In all other cases, clients are expected to acknowledge the successful arrival of data chunks by sending acknowledgement datagrams back to the server. UDP acknowledgement datagrams are sent to the same host address and port as the connection establishment datagram. Moreover, clients shall send acknowledgement datagrams from a socket bound to the same local address and port as that used to send the connection establishment datagram. Each acknowledgement datagram consists of one or more chunk headers from received data chunks, except that the "control" field is modified as follows. The 8-bit D value in the returned chunk header's "control" field should be modified to reflect (at least approximately) the number of microseconds between client receipt of the data chunk and delivery of the acknowledgement datagram, expressed as  $2^{(D/8)}$  microseconds. The 4-bit A value in the returned chunk header's "control" field should be modified to reflect the number of previous datagrams in which the client has already acknowledged the receipt of the data chunk in question. This information is reflected in Table K.1. No acknowledgement datagram shall be more than 512 bytes. That is, no acknowledgement datagram shall contain more than 64 chunk headers. Connection establishment datagrams are distinguished from acknowledgement datagrams on the basis of the first 4 bits of the control field, as shown in Table K.1.
+
+Even if the client has already identified a data chunk via an Abandon request field, if that chunk is subsequently received, the client can acknowledge its arrival via an acknowledgement datagram; this is generally advisable as it can reduce redundant transmission of information from the server. In this event, however, the client is expected to update its cache accordingly. That is, the client shall not acknowledge data chunks which it discards, since then the server's log of what the client should have received might contain erroneous entries.
+
+Clients can acknowledge the same data chunk multiple times in separate acknowledgement datagrams; in the event of multiple acknowledgements, the modified D and A values will generally be different. Clients need not send a separate acknowledgement datagram for each received data chunk, but they should endeavour to acknowledge data chunks within the period specified by the D value in the chunk header's "control" field.
+
+NOTE 1 – Acknowledgement can be used by servers for flow-control purposes. Note further that once a data chunk has been acknowledged by a client, subsequent Abandon request fields that refer to already acknowledged chunks might be ignored by the server. In some server implementations, this means that the receipt of acknowledgement information allows the server to release temporary storage resources that might be needed to maintain cache model consistency.
+
+NOTE 2 – Notwithstanding the guidelines presented above, it is acceptable for a client to promptly return a single acknowledgement datagram for each received data chunk, containing just the one chunk header, with the "control" field set to 0. The D values are intended primarily to allow server flow control algorithms to take into account the additional delay which might be incurred where a client chooses to aggregate data chunk acknowledgements into a smaller number of acknowledgement datagrams. The A values are intended to allow a server to estimate loss probability for acknowledgement datagrams and feed suggested repetition counts to the client to increase the robustness of the acknowledgement mechanism.
+
+## **K.7 UDP and Maximum Response Length Field (informative)**
+
+There might be little or no reason for using the Maximum Response Length field with a UDP return channel, unless the Sendto request field is also being used. Apart from this case, the server should be able to use the times at which acknowledgement datagrams arrive to regulate the flow of response data to the client, so as to maintain responsiveness. If the Sendto request field is used, however, the server does not receive continuous feedback from the client and can easily push a great deal of data over the channel. To maintain responsiveness or avoid excessive loss in these circumstances, clients should use the Maximum Response Length field (see C.6.1) to regulate the flow of traffic, much as they would with the HTTP transport.
+
+## **K.8 Implementation strategies for acknowledged communication (informative)**
+
+Response data chunks delivered in response to requests that do not contain the Sendto request field are acknowledged via explicit acknowledgment datagrams. This model is quite common in network communication protocols and facilitates the implementation of flow control management within the server. Although not required by this Recommendation | International Standard, servers are recommended to adopt a retransmission strategy, in which data chunks that have not been acknowledged after an appropriate period of time are retransmitted, unless the server is able to determine that the data chunks are no longer relevant to the client – e.g., due to a change in the client's window of interest. Typically, the retransmission would stop, once a data chunk is either acknowledged or abandoned by means of an Abandon request field.
+
+Clients cannot expect servers to retransmit data chunks that are not acknowledged. Moreover, the client cannot generally have any guarantee of the point at which a server might decide that an unacknowledged data chunk has not arrived at the client. This is important, since it can affect the interpretation of responses to future requests. For example, the response to a future request might include an EOR message with the "Window Done" reason code, yet the client cannot be sure that it has indeed received all relevant content if an earlier request with overlapping Window of Interest still has outstanding missing data chunks. To avoid the ambiguity which might be created by such situations, clients can use the Abandon request field to explicitly abandon missing data chunks from requests that have not received any content for some time. This allows the client to be sure that the server will eventually include any relevant content that was missing from those requests in its response to future requests.
+
+If a client does not need to rely upon the reason codes supplied by EOR messages (e.g., because the client can directly compute whether its cache contents contain a complete response to a requested Window of Interest), there might be no need for it to consider use of the Abandon request field.
+
+Clients should bear in mind that aggressive use of the Abandon request field can significantly increase server workload. For example, a typical server might generate data chunks in batches which are then scheduled for transmission. If a client automatically issues Abandon request fields referring to all previous requests whenever its Window of Interest changes in any way, the server might discard many of the data chunks it has generated without transmitting them at all. Although this does not break interoperability, the server might have to regenerate content many times over during an interactive session. To avoid this problem, it is recommended that clients wait until at least one data chunk is received from a request A before issuing an Abandon request that refers to data chunks from an earlier request B, unless no data chunks are received at all for a considerable period of time. It is generally possible for the server to make better decisions than the client regarding data chunks which should not be transmitted because the client's Window of Interest has changed.
+
+The Barrier request field is not primarily intended for use with acknowledged communication. Nevertheless, if this request field is used by a client, it provides a supplementary mechanism to implicitly acknowledge the arrival of data chunks that have not been abandoned – it can be that acknowledgement datagrams for some of these have been lost. Ignoring a Barrier request field does not damage interoperability in JPIP but might lead to some redundant transmission, so servers are recommended to implement this feature.
+
+## **K.9 Implementation strategies for unacknowledged communication (informative)**
+
+Response data chunks delivered in response to requests that contain the Sendto request field are not acknowledged via acknowledgement datagrams. As with all JPIP communications, the server can assume that data which it has sent to the client arrive and are cached by the client, unless and until it learns otherwise. Without this assumption, the server would find itself transmitting the same content over and over again in a typical interactive session. Since UDP is an unreliable
+
+transport medium, the server needs to be prepared for the possibility that data chunks are actually lost. In particular, it needs to be prepared to process Abandon request fields.
+
+A typical server would keep a record of the data-bin byte ranges that are contained within each data chunk that has been sent to the client. If the data chunk is abandoned, the record can be erased and the server should remove the relevant data-bin byte ranges from its log of content the client has received (i.e., its client cache model); this content can be delivered again in response to future requests, if deemed relevant. Since Abandon requests provide only a mechanism for the client to declare that it has not received some data chunks, if no other steps are taken by the client, the servers record of data chunks that have been sent and not yet abandoned could grow indefinitely; as a result, a typical server would eventually need to internally abandon data chunks, so that everything gets abandoned in the long run. This would eventually cause a great deal of redundant transmission, but clients can avoid the problem using one of the following two strategies:
+
+- 1) A client implementation can arrange to send additive cache model manipulation statements that directly add all received data-bin byte ranges to the server's cache model. This avoids redundant computation, so long as servers do not accidentally erase this information again while abandoning the relevant data chunks at a later point. To avoid such possibilities and reduce the burden on servers, clients are strongly recommended to use the Abandon and Model request fields together, to declare all data chunks from a given previous request abandoned but simultaneously add all the data-bin byte ranges from the arrived data chunks to the server's cache model via the Model request field. More generally, it is preferable for clients to abandon data chunks explicitly rather than leave servers to do so implicitly at an undefined point in the future; and it is preferable for clients to abandon data chunks during the same or an earlier request to that in which the arrived content is identified via the Model request field. Keeping this in mind, it is preferable for servers to process the effects of an Abandon request field prior to the processing of any Model request field found in the same request.
+- 2) A client implementation can use the Barrier request field to assure the server that no subsequent request will contain an Abandon request field which abandons data chunks belonging to requests prior to a certain point. This effectively acknowledges the successful arrival of all data chunks not yet abandoned from requests prior to the request-id specified by Barrier. To help conserve server bookkeeping resources, clients are recommended to use Barrier regularly. A typical client implementation might abandon all non-arrived data chunks associated with a request which is sufficiently old and simultaneously use the Barrier request field to indicate to the server that there will be no further abandonment for data chunks from that request.
+
+## Annex L
+
+### Registration of extensions
+
+(This annex does not form an integral part of this Recommendation | International Standard.)
+
+Intentionally left blank
+
+*Editorial note – The first edition of this Recommendation | International Standard used this annex to describe a JPIP Registration Authority. However, the registration authority was not used, and the preferred approach by ITU and ISO for adding new features to an existing standard is through amendments and revisions. Consequently, the original contents of the annex have been removed from this edition.*
+
+## Annex M
+
+### Application examples
+
+(This annex does not form an integral part of this Recommendation | International Standard.)
+
+#### M.1 Introduction
+
+This annex presents some informative examples of aspects of JPIP implementations.
+
+#### M.2 Use of JPIP with codestreams in other file formats
+
+JPIP can be used to access JPEG 2000 codestreams stored in file formats other than JPEG 2000 family files. For example, DICOM and PDF files both have the capability to contain JPEG 2000 codestreams. In a client server environment, some procedure not specified in this Recommendation | International Standard can be used to locate the JPEG 2000 codestream. JPIP requests and responses can be used on the object once the codestream is located. The Sub-target request field is intended for just such a situation. Alternatively, a server could provide access to the codestreams via a different URL.
+
+#### M.3 Tile-part implementation techniques
+
+##### M.3.1 Server determination of relevant tile-parts for a view-window request
+
+For communication via tile-part, the mapping of a view-window to a set of tiles is simple. The desired region of the image is converted to "reference grid units." The *XTsiz* and *YTsiz* portions of the *SIZ* marker segment are used to determine which tiles intersect with the view-window.
+
+NOTE – Although on the reference grid all tiles have the same dimensions, on the subsampled reference grid, after sub-band decomposition, tiles do not necessarily all have the same dimensions. A tile intersecting the view-window, even a tile contained completely within it, might contribute no samples to the view-window at the lowest resolution levels; however, implementations need not take advantage of this occurrence by omitting the tile altogether from the response.
+
+The resolution level and quality are used to determine the tile-parts needed. The Tile-part Index Table box, if available, can be used to obtain information about the location of tile-parts in the codestream and (if Auxiliary fields are included) the completion of resolution levels within tile-parts. The *SOT* marker segments also give the tile and tile-part indices and the number of bytes in each tile-part. From the codestream, the appropriate bytes, corresponding to the tile-parts that need to be sent, are transmitted to the client. In case the view-window changes and the corresponding relevant tiles also change, then only relevant tile-parts that have not been sent earlier need be sent to update the display image.
+
+##### M.3.2 Decoding an image from returned JPT-stream messages
+
+JPIP specifies mechanisms to communicate compressed image data and metadata between a client and a server. The mechanisms for the client to display the returned data are not specified, and indeed will vary widely between applications. This subclause provides information on obtaining component samples from returned data.
+
+A client application that has received all of the main header data (indicated by the completed header data-bin appearing in a response message for header-data-bin 0), can concatenate that data-bin with complete tile-parts from tile data-bins to form a valid JPEG 2000 codestream. This codestream can be provided to a conformant JPEG 2000 decoder and the result displayed. Of course, for efficiency purposes, a client might wish to provide view-window parameters to an intelligent decoder along with the codestream so only portions needed for the current view-window will be displayed.
+
+##### M.3.3 Auxiliary signalling for tile-parts
+
+Tables M.1 and M.2 illustrate the use of Auxiliary fields in extended tile data-bin messages and in the Tile-part Index Table box.
+
+NOTE – In this example, the definition of *r* differs from that used in other places in this Recommendation | International Standard, but is consistent with Rec. ITU-T T.800 | ISO/IEC 15444-1.
+
+Table M.1 illustrates a simple case in which all tile-components of a resolution-progressive tile have the same number of decomposition levels and in which the message boundaries (in the data-bin case) or tile-part boundaries (in the index box case) occur only between each successive resolution level.
+
+Table M.1 – Example of the use of auxiliary fields in a simple case
+
+| Message sequence number in data-bin, or tile-part number in tile | Resolution level $r$ | $n = N_L - r$ | Auxiliary value |
+|------------------------------------------------------------------|----------------------|---------------|-----------------|
+| 0                                                                | 0                    | 2             | 2               |
+| 1                                                                | 1                    | 1             | 1               |
+| 2                                                                | 2                    | 0             | 0               |
+
+Table M.2 illustrates a more complicated case in which the number of decomposition levels varies by tile-component. A comment is made in the final column of the table on the first occurrence of each new Auxiliary value. This case corresponds to a tile from a three-component image in an RC... progression order, for example the LRCP progression order with a single layer, or the RPCL progression order with a single precinct in the tile. The message boundaries (in the data-bin case) or tile-part boundaries (in the index box case) occur between each component of each resolution level as well as between resolution levels. Components 0 and 1 have two decomposition levels ( $N_L = 2$ ) and component 2 has a single decomposition level ( $N_L = 1$ ).
+
+Table M.2 – Example of the use of auxiliary fields in a more complicated case
+
+| Message sequence number in data-bin, or tile-part number in tile | Component index $c$ | Resolution level $r$ | $n = N_L - r$ | Auxiliary value | Comment                   |
+|------------------------------------------------------------------|---------------------|----------------------|---------------|-----------------|---------------------------|
+| 0                                                                | 0                   | 0                    | 2             | 3               | No level complete         |
+| 1                                                                | 1                   | 0                    | 2             | 2               | $n = 2$ now complete      |
+| 2                                                                | 2                   | 0                    | 1             | 2               |                           |
+| 3                                                                | 0                   | 1                    | 1             | 2               |                           |
+| 4                                                                | 1                   | 1                    | 1             | 1               | $n = 1$ now also complete |
+| 5                                                                | 2                   | 1                    | 0             | 1               |                           |
+| 6                                                                | 0                   | 2                    | 0             | 1               |                           |
+| 7                                                                | 1                   | 2                    | 0             | 0               | All levels now complete   |
+
+M.4      Precinct-based implementation techniques
+
+M.4.1    Server determination of relevant precincts for a view-window request
+
+When communication involves the JPP-stream media type, the server translates the client's requested image region into a set of precincts which are relevant to the request. The first part of this process involves translation of the  $fx$ ,  $fy$ ,  $sx$ ,  $sy$ ,  $ox$  and  $oy$  parameters supplied by the Frame Size, Region Size and Region Offset request fields, into codestream frame size, region size and offset parameters  $fx'$ ,  $fy'$ ,  $sx'$ ,  $sy'$ ,  $ox'$  and  $oy'$ , for each relevant codestream. This translation proceeds in the same way for both precinct- and tile-based services, and is based on Equations C-1 and C-2, possibly modified according to Equations C-3 and C-4. This subclause describes how a server should determine the precincts which are relevant to the region defined by parameters  $fx'$ ,  $fy'$ ,  $sx'$ ,  $sy'$ ,  $ox'$  and  $oy'$ , within a particular codestream.
+
+Let  $r$  be the non-negative integer in Equation C-1 which was used by the server to find  $fx'$  and  $fy'$ , based on the client's request. As mentioned in connection with Equation C-1,  $r$  is most easily interpreted as the number of discarded highest resolution DWT levels, even though  $r$  is allowed to exceed the actual number of DWT levels which are available for any given tile-component. It is convenient to first map the region described by  $sx'$ ,  $sy'$ ,  $ox'$  and  $oy'$  onto the codestream's high-resolution grid. This yields a region whose upper left hand corner is given by  $(E_1^{\text{reg}}, E_2^{\text{reg}})$  and whose lower right hand corner is given by  $(F_1^{\text{reg}} - 1, F_2^{\text{reg}} - 1)$ , where:
+
+$$E_1^{\text{reg}} = X\text{Osiz} + 2^r \cdot ox', \quad E_2^{\text{reg}} = Y\text{Osiz} + 2^r \cdot oy', \quad F_1^{\text{reg}} = E_1^{\text{reg}} + 2^r \cdot sx', \quad \text{and} \quad F_2^{\text{reg}} = E_2^{\text{reg}} + 2^r \cdot sy'$$
+
+The server need only consider those tiles which intersect with this region on the codestream's high-resolution grid. For each such tile, the server need only consider those image components which are requested by the client, in the manner described in connection with the Component and Codestream Context request fields. For each considered tile-component, denoted by  $t$  and  $c$ , let  $D_{t,c}$  be the number of DWT levels which were used to compress that tile-component. If  $D_{t,c} \geq r$ , the server should discard all precincts belonging to the tile-component's  $r$  highest resolution levels; otherwise, it should
+
+discard all precincts belonging to the tile-component's  $D_{t,c}$  highest resolution levels, leaving only those precincts which represent the tile-component's lowest LL sub-band.
+
+For each precinct which remains after the discarding of tiles, components and resolution levels mentioned above, the server should identify whether or not the code-blocks which belong to that precinct contribute to the reconstruction of the region defined by  $E_1^{\text{reg}}$ ,  $E_2^{\text{reg}}$  and  $F_1^{\text{reg}}$ ,  $F_2^{\text{reg}}$  on the codestream's high-resolution grid. A code-block contributes to this region if any of its samples affects the reconstruction of any full-resolution image component sample whose coordinates  $(x,y)$  satisfy:
+
+$$E_1^{\text{reg}} \leq \text{XRsiz}^c \cdot x < F_1^{\text{reg}} \quad \text{and} \quad E_2^{\text{reg}} \leq \text{YRsiz}^c \cdot y < F_2^{\text{reg}}$$
+
+where  $\text{XRsiz}^c$  and  $\text{YRsiz}^c$  denote the horizontal and vertical subsampling factors for the relevant component,  $c$ , in the codestream's SIZ marker segment.
+
+It is important to bear in mind that the reconstruction of a full-resolution image component involves wavelet synthesis, which is an inherently expansive process. Thus, the region to which any given precinct contributes generally overlaps the regions to which its neighbouring precincts contribute. The server should be prepared to account for these expansive effects of the wavelet transform when determining the precincts which are relevant to a client's request.
+
+Section 10.6.4 of the book "JPEG2000: image compression fundamentals, standards and practice" [11] describes one way to calculate the samples of any given sub-band which contribute to a given region on the codestream's high-resolution grid. From the sub-band regions, it is a simple matter to deduce the contributing code-blocks and hence precincts.
+
+#### M.4.2 Decoding an image from returned JPP-stream messages
+
+JPIP specifies mechanisms to communicate compress image data and metadata between a client and a server. The mechanisms for the client to display the returned data are not specified, and indeed will vary widely between applications.
+
+### M.5 JPIP protocol transcripts
+
+#### M.5.1 Introduction
+
+In the following example transcripts, the text following the symbols "<<" at the beginning of a line is sent from the client to the server, the text following the symbols ">>" at the beginning of a line is sent from the server to the client, and the text following the symbols "--" is a comment and is not actually transmitted. The comments might indicate that some of the data transmitted is not shown.
+
+#### M.5.2 Using HTTP
+
+The following transcript shows five requests sent from the client to the server and the response of the server.
+
+The first request asks for the JP2 file called phoenix.jp2, the first codestream in the file is requested, a maximum length is put on the response, a target id is requested, the data is requested to be returned as a JPP-stream, and establishment of a session over HTTP is requested. No window, and hence no image data is requested.
+
+The server replies providing a target ID for the image, and an ID for the newly established channel. The header line starting "JPIP-cnew" indicates a new path that can be used to access the image file. The value for the path "jpip" might be a path to a CGI program on the server designed to deal with all JPIP interactive commands. Some data from the file is returned in the body; these will be file format boxes, and perhaps the main header of the first codestream.
+
+The client's second request uses the new path, "jpip.cgi", and the channel ID to identify the desired image (no image name or target ID is necessary). This request also specifies a particular window of interest.
+
+The response to the second request indicates that the view-window has been changed and a smaller window centred in the requested view-window is being returned. The server starts returning the data for this window.
+
+Before receiving the complete response to the second request, the client issues a third request. The client has adjusted its view-window to the size specified by server.
+
+The server continues to respond to the second request for a while, then starts a response to the third request. During this response, the client issues a fourth request with a slightly different region. The server continues to respond to the third request for a while then starts responding to the fourth request.
+
+The client waits until the fourth response has completed, then issues a request to terminate both the session and the HTTP connection. There is no response data shown in this case as the connection closes.
+
+```
+<< GET /phoenix.jp2?stream=0&len=2000&tid=0&type=jpp-stream&cnew=http HTTP/1.1
+<< Host: dst-m
+```
+
+```
+
+<<
+>> HTTP/1.1 200 OK
+>> JPIP-tid: 281B6E135135BBC0BC588452AC9B73C5
+>> JPIP-cnew: cid=JPH_033C38BE48115AC9,path=jpip.cgi,transport=http
+>> Cache-Control: no-cache
+>> Transfer-Encoding: chunked
+>> Content-Type: image/jpp-stream
+>>
+>> 102
+>> -- 258 bytes of binary data
+>> 0
+>>
+<< GET /jpip.cgi?fsiz=834,834&roff=0,0&rsiz=834,790&comps=0-
+2&stream=0&len=2000&cid=JPH_033C38BE48115AC9 HTTP/1.1
+<< Host: dst-m
+<< Cache-Control: no-cache
+<<
+>> HTTP/1.1 200 OK, with modifications
+>> JPIP-roff: 120,114
+>> JPIP-rsiz: 593,561
+>> Cache-Control: no-cache
+>> Transfer-Encoding: chunked
+>> Content-Type: image/jpp-stream
+>>
+>> 393
+>> -- 915 bytes of binary data
+<< GET /jpip.cgi?fsiz=834,834&roff=120,114&rsiz=593,561&comps=0-
+2&stream=0&len=2000&cid=JPH_033C38BE48115AC9 HTTP/1.1
+<< Host: dst-m
+<< Cache-Control: no-cache
+<<
+>> 3f9
+>> -- 1017 bytes of binary data
+>> 0
+>>
+>> HTTP/1.1 200 OK
+>> Cache-Control: no-cache
+>> Transfer-Encoding: chunked
+>> Content-Type: image/jpp-stream
+>>
+>> 359
+>> -- 857 bytes of binary data
+<< GET /jpip.cgi?fsiz=834,834&roff=309,297&rsiz=121,86&comps=0-
+2&stream=0&len=3906&cid=JPH_033C38BE48115AC9 HTTP/1.1
+<< Host: dst-m
+<< Cache-Control: no-cache
+<<
+>> 234
+>> -- 564 bytes of binary data
+>> 3d0
+>> -- 976 bytes of binary data
+>> 24f
+>> -- 591 bytes of binary data
+>> 0
+>>
+>> HTTP/1.1 200 OK
+>> Cache-Control: no-cache
+>> Transfer-Encoding: chunked
+>> Content-Type: image/jpp-stream
+>>
+>> 3b2
+>> -- 946 bytes of binary data
+>> 400
+>> -- 1024 bytes of binary data
+>> 263
+>> -- 611 bytes of binary data
+>> 356
+>> -- 854 bytes of binary data
+>> 209
+>> -- 521 bytes of binary data
+>> 0
+
+```
+
+```
+<< GET /jpip.cgi?cclose=JPH_033C38BE48115AC9&len=0 HTTP/1.1
+<< Host: dst-m
+<< Connection: close
+<< Cache-Control: no-cache
+<<
+```
+
+The following is an example of session-based HTTP GET with a model request.
+
+```
+<< GET /jpip.cgi?fsiz=1024,768&cid=JPH_5&model=Hm,H*,M*,P* HTTP/1.1
+<< Host: jpip.jpeg.org
+<< Cache-Control: no-cache
+
+>> HTTP/1.1 200 OK
+>> Cache-control: no-cache
+>> Transfer-Encoding: chunked
+>> 3
+-- 3 bytes of binary data
+>> 0
+```
+
+The following is an example of a stateless HTTP GET with a model request.
+
+```
+<< GET /images/kids.jp2?fsiz=1024,768&model=M0,Hm,H0:20,P0 HTTP/1.1
+<< Host: jpip.jpeg.org
+<< Cache-Control: no-cache
+
+>> HTTP/1.1 200 OK
+>> Cache-Control: no-cache
+>> Transfer-Encoding: chunked
+>> Content-Type: image/jpp-stream
+>> 400
+-- 1024 bytes of binary data
+>> 3f8
+-- 1016 bytes of binary data
+>> 0
+```
+
+### M.5.3 Using HTTP with TCP return
+
+```
+<< GET /phoenix.jp2?stream=0&len=2000&tid=0&type=jpp-stream&cnew=http-tcp,http
+HTTP/1.1
+<< Host: dst-m
+<<
+
+>> HTTP/1.1 200 OK
+>> JPIP-tid: 281B6E135135BBC0BC588452AC9B73C5
+>> JPIP-cnew: cid=JPHT033C38BE481154F9,path=jpip,transport=http-tcp,auxport=80
+>> Cache-Control: no-cache
+>>
+
+    << JPHT033C38BE481154F9 - [Note: This is the TCP channel connection message]
+    <<
+
+<< GET /jpip.cgi?fsiz=834,834&roff=0,0&rsiz=834,790&comps=0-
+2&stream=0&cid=JPHT033C38BE481154F9 HTTP/1.1
+<< Host: dst-m
+<< Cache-Control: no-cache
+<<
+
+>> HTTP/1.1 200 OK, with modifications
+>> JPIP-roff: 120,114
+>> JPIP-rsiz: 593,561
+>> Cache-Control: no-cache
+>>
+
+<< GET /jpip.cgi?fsiz=834,834&roff=229,254&rsiz=155,113&comps=0-
+2&stream=0&cid=JPHT033C38BE481154F9 HTTP/1.1
+<< Host: dst-m
+<< Cache-Control: no-cache
+<<
+
+>> HTTP/1.1 200 OK
+>> Cache-Control: no-cache
+>>
+
+<< GET /jpip.cgi?fsiz=1667,1667&roff=457,507&rsiz=310,226&comps=0-
+2&stream=0&cid=JPHT033C38BE481154F9 HTTP/1.1
+<< Host: dst-m
+<< Cache-Control: no-cache
+```
+
+```
+
+<<
+>> HTTP/1.1 200 OK
+>> Cache-Control: no-cache
+>>
+
+<< GET /jpip.cgi?fsiz=3334,3334&roff=914,1014&rsiz=620,452&comps=0-
+2&stream=0&cid=JPHT033C38BE481154F9 HTTP/1.1
+<< Host: dst-m
+<< Cache-Control: no-cache
+<<
+>> HTTP/1.1 200 OK
+>> Cache-Control: no-cache
+>>
+
+<< GET /jpip.cgi?cclose=JPHT033C38BE481154F9 HTTP/1.1
+<< Host: dst-m
+<< Cache-Control: no-cache
+<<
+
+```
+
+## M.6 Using JPIP with HTML
+
+A JPIP system can be used with HTML and XHTML pages in a variety of ways. If a JPIP server includes the ability to transcode portions of an image to JPEG or other complete image media types, then HTML can be used to access portions of a JPEG 2000 image without any changes to current browsers.
+
+Consider a web page containing the following HTML fragment:
+
+```
+
+<img src="http://jpip.jpeg.org/name.jp2?fsiz=128,128&rsiz=128,128&type=image/jpeg"
+width="128" height="128">
+
+```
+
+Any web browser wishing to display this web page with images will issue a request to obtain the image. This request will start to:
+
+```
+
+GET /name.jp2?fsiz=128,128&rsiz=128,128&type=image/jpeg
+Host: jpip.jpeg.org
+
+```
+
+and will include many other HTTP header lines, typically identifying the browser, and the types of things the browser accepts. This HTTP request is a valid JPIP request and a JPIP server which receives this request shall either return an error message or determine the relevant portion of the JP2 file to access and translate it to a JPEG file. The returned message could look like:
+
+```
+
+HTTP/1.1 200 OK
+Content-type: image/jpeg
+Content-length: 20387
+CRLF
+JPEG-Compressed-Image-Data
+
+```
+
+Which is a valid JPIP response, and is also a valid HTTP response that all image browsers know how to display. Note that it is preferred but not required for the server to use the chunked transfer-encoding so that this request could be interrupted. The preceding example is not an example of chunked transfer-encoding.
+
+It is also possible to write web pages which will use JPEG when only JPEG is available, use JPEG 2000 when available, and JPT-stream or JPP-stream when available in the client's browser. Consider the HTML fragment:
+
+```
+
+<img src="http://jpip.jpeg.org/name.jp2?rsiz=128,128" width="128" height="128">
+
+```
+
+In this case, there is no explicit type requested. A JPIP server using HTTP should therefore examine the "Accept:" line of the HTTP request issued by the client. Depending on the presence of image/jp2 or image/jpt-stream or image/jpp-stream or image/jpeg, the server can determine a compatible format to return.
+
+## Annex N
+
+## JPIP ABNF collection
+
+(This annex does not form an integral part of this Recommendation | International Standard.)
+
+## N.1 JPIP Request ABNF
+
+```
+
+;=====
+; C.1.1 Request structure
+;=====
+
+jpip-request-field = target-field
+                    / channel-field
+                    / view-window-field
+                    / metadata-field
+                    / data-limit-field
+                    / server-control-field
+                    / cache-management-field
+                    / upload-field
+                    / client-cap-pref-field
+
+target-field       = target           ; C.2.2
+                    / subtarget       ; C.2.3
+                    / tid              ; C.2.4
+
+channel-field      = cid              ; C.3.2
+                    / cnew            ; C.3.3
+                    / cclose          ; C.3.4
+                    / qid             ; C.3.5
+
+view-window-field  = fsiz             ; C.4.2
+                    / roff            ; C.4.3
+                    / rsiz            ; C.4.4
+                    / fvsiz           ; C.4.5
+                    / rvoff           ; C.4.6
+                    / rvsiz           ; C.4.7
+                    / comps           ; C.4.8
+                    / stream          ; C.4.9
+                    / context         ; C.4.10
+                    / srates          ; C.4.11
+                    / roi             ; C.4.12
+                    / layers          ; C.4.13
+                    / mctres          ; C.4.14
+
+metadata-field     = metareq          ; C.5.2
+
+data-limit-field   = len              ; C.6.1
+                    / quality         ; C.6.2
+
+server-control-field = align          ; C.7.1
+                    / wait           ; C.7.2
+                    / type           ; C.7.3
+                    / drate          ; C.7.4
+                    / sendto         ; C.7.5
+                    / abandon        ; C.7.6
+                    / barrier        ; C.7.7
+                    / twait          ; C.7.8
+
+cache-management-field = model        ; C.8.1
+                    / tpmodel        ; C.8.3
+                    / need           ; C.8.4
+                    / tpneed         ; C.8.5
+                    / mset           ; C.8.6
+
+upload-field       = upload           ; C.9.1
+
+client-cap-pref-field = cap           ; C.10.1
+                    / pref           ; C.10.2
+                    / csf            ; C.10.3
+                    / handled        ; C.10.4
+
+```
+
+```
+
+=====
+; C.2.2 Target (target)
+;=====
+
+target = "target" "=" PATH
+
+;=====
+; C.2.3 Sub-target (subtarget)
+;=====
+
+subtarget = "subtarget" "=" byte-range
+byte-range = UINT-RANGE
+
+;=====
+; C.2.4 Target ID (tid)
+;=====
+
+tid = "tid" "=" target-id
+target-id = TOKEN
+
+;=====
+; C.3.1 Channel ID (cid)
+;=====
+
+cid = "cid" "=" channel-id
+channel-id = TOKEN
+
+;=====
+; C.3.2 New Channel (cnew)
+;=====
+
+cnew = "cnew" "=" 1#transport-name
+transport-name = TOKEN
+
+;=====
+; C.3.3 Channel Close (cclose)
+;=====
+
+cclose = "cclose" "=" ("*" / 1#channel-id)
+
+;=====
+; C.3.4 Request ID (qid)
+;=====
+
+qid = "qid" "=" UINT
+
+;=====
+; C.4.2 Frame Size (fsiz)
+;=====
+
+fsiz = "fsiz" "=" fx "," fy ["," round-direction]
+fx = UINT
+fy = UINT
+round-direction = "round-up" / "round-down" / "closest"
+
+;=====
+; C.4.3 Offset (roff)
+;=====
+
+roff = "roff" "=" ox "," oy
+ox = UINT
+oy = UINT
+
+;=====
+; C.4.4 Region Size (rsiz)
+;=====
+
+rsiz = "rsiz" "=" sx "," sy
+sx = UINT
+sy = UINT
+
+```
+
+```
+
+;=====
+; C.4.5 Frame Size for Variable Dimension Data (fvsiz)
+;=====
+
+fvsiz = "fvsiz" "=" 1#UINT ["," round-direction]
+round-direction = "round-up" / "round-down" / "closest"
+
+;=====
+; C.4.6 Offset for Variable Dimension Data (rvoff)
+;=====
+
+rvoff = "rvoff" "=" 1#UINT
+
+;=====
+; C.4.7 Region Size for Variable Dimension Data (rvsiz)
+;=====
+
+rvsiz = "rvsiz" "=" 1#UINT
+
+;=====
+; C.4.8 Components (comps)
+;=====
+
+comps = "comps" "=" 1#UINT-RANGE
+
+;=====
+; C.4.9 Codestream (stream)
+;=====
+
+stream = "stream" "=" 1#sampled-range
+sampled-range = UINT-RANGE [":" sampling-factor]
+sampling-factor = UINT
+
+;=====
+; C.4.10 Codestream Context (context)
+;=====
+
+context = "context" "=" 1#context-range
+context-range = jpxl-context-range / mj2t-context / reserved-context
+jpxl-context-range = "jpxl" "<" jpx-layers ">" [ "[" jpxl-geometry "]" ]
+jpx-layers = sampled-range
+jpxl-geometry = "s" jpx-iset "i" jpx-inum
+jpx-iset = UINT
+jpx-inum = UINT
+mj2t-context = "mj2t" "<" mj2-track ">" [ "[" mj2t-geometry "]" ]
+mj2-track = NONZERO ["+" "now" ]
+mj2t-geometry = "track" / "movie"
+reserved-context = 1*( TOKEN / "<" / ">" / "[" / "]" / "-" / ":" / "+" )
+
+;=====
+; C.4.11 Sampling Rate (srate)
+;=====
+
+srate = "srate" "=" streams-per-second
+streams-per-second = UFLOAT
+
+;=====
+; C.4.12 ROI (roi)
+;=====
+
+roi = "roi" "=" region-name
+region-name = 1*(DIGIT / ALPHA / "_" ) / "dynamic"
+
+```
+
+```
+
+;=====
+; C.4.13 Layers (layers)
+;=====
+
+layers = "layers" "=" UINT
+
+;=====
+; C.4.14 Multi-component transformation (MCT) resolution value (mctres)
+;=====
+
+mctres = "mctres" "=" UINT
+
+;=====
+; C.5.2 Metadata Request (metareq)
+;=====
+
+metareq = "metareq" "=" 1#("[ 1$(req-box-prop) "]" [root-bin] [max-depth])
+                                         [metadata-only]
+
+req-box-prop = box-type [limit] [metareq-qualifier] [priority]
+limit = ":" (UINT / "r")
+metareq-qualifier = "/" 1*("w" / "s" / "g" / "a")
+priority = "!"
+
+root-bin = "R" UINT
+max-depth = "D" UINT
+metadata-only = "!!"
+
+;=====
+; C.6.1 Maximum Response Length (len)
+;=====
+
+len = "len" "=" UINT
+
+;=====
+; C.6.2 Quality (quality)
+;=====
+
+quality = "quality" "=" (1*2DIGIT / "100")           ; 0 to 100
+
+;=====
+; C.7.1 Alignment (align)
+;=====
+
+align = "align" "=" ("yes" / "no")
+
+;=====
+; C.7.2 Wait (wait)
+;=====
+
+wait = "wait" "=" ("yes" / "no")
+
+;=====
+; C.7.3 Image Return Type (type)
+;=====
+
+type = "type" "=" 1#image-return-type
+image-return-type = media-type / reserved-image-return-type
+media-type = TOKEN "/" TOKEN *( ";" parameter )
+reserved-image-return-type = TOKEN *( ";" parameter )
+parameter = attribute "=" value
+attribute = TOKEN
+value = TOKEN
+
+```
+
+```
+
+ ;
+ ; C.7.4 Delivery Rate (drate)
+ ;
+
+drate = "drate" "=" rate-factor
+rate-factor = UFLOAT
+
+ ;
+ ; C.7.5 Send To (sendto)
+ ;
+
+sendto = "sendto" "=" host ":" port ";" mbw ";" bpc
+host = token
+port = UINT
+bpc = UINT
+
+ ;
+ ; C.7.6 Abandon (abandon)
+ ;
+
+abandon = "abandon" "=" 1#chunk-range
+chunk-range = chunk-qid ":" chunk-seq-range
+chunk-qid = UINT
+chunk-seq-range = UINT-RANGE
+
+ ;
+ ; C.7.7 Barrier (barrier)
+ ;
+
+barrier = "barrier" "=" barrier-qid
+barrier-qid = UINT
+
+ ;
+ ; C.7.8 Timed wait (twait)
+ ;
+
+twait = "twait" "=" max-wait-usecs
+max-wait-usecs = UINT
+
+ ;
+ ; C.8.1.1 Model (model)
+ ;
+
+model = "model" "=" 1#model-item
+model-item = [codestream-qualifier ","] model-element
+model-element = ["-"] bin-descriptor
+bin-descriptor = explicit-bin-descriptor ; C.8.1.2
+ / implicit-bin-descriptor ; C.8.1.3
+codestream-qualifier = "[" 1$(codestream-range) "]"
+codestream-range = first-codestream-id ["-" [last-codestream-id]]
+first-codestream-id = UINT
+last-codestream-id = UINT
+
+ ;
+ ; C.8.1.2 Explicit Form
+ ;
+
+explicit-bin-descriptor = explicit-bin
+ [":" (number-of-bytes / number-of-layers )]
+
+```
+
+```
+
+explicit-bin = codestream-main-header-bin
+              / meta-bin
+              / tile-bin
+              / tile-header-bin
+              / precinct-bin
+
+number-of-bytes = UINT
+
+number-of-layers = %x4c UINT           ; "L"
+
+codestream-main-header-bin = %x48 %x6d   ; "Hm"
+
+meta-bin = %x4d bin-uid                 ; "M"
+
+tile-bin = %x54 bin-uid                 ; "T"
+
+tile-header-bin = %x48 bin-uid           ; "H"
+
+precinct-bin = %x50 bin-uid             ; "P"
+
+bin-uid = UINT / "*"
+
+;=====
+; C.8.1.3 Implicit Form
+;=====
+
+implicit-bin-descriptor = 1*implicit-bin [":" number-of-layers]
+
+implicit-bin = implicit-bin-prefix (data-uid / index-range-spec)
+
+implicit-bin-prefix = %x74           ; t -- tile
+                    / %x63           ; c -- component
+                    / %x72           ; r -- resolution level
+                    / %x70           ; p -- position
+
+index-range-spec = first-index-pos "-" last-index-pos
+
+first-index-pos = UINT
+
+last-index-pos = UINT
+
+data-uid = UINT / "*"
+
+;=====
+; C.8.3 Tile-part Model involving JPT-streams (tpmodel)
+;=====
+
+tpmodel = "tpmodel" "=" 1#tpmodel-item
+
+tpmodel-item = [codestream-qualifier "," ] tpmodel-element
+
+tpmodel-element = ["-"] tp-descriptor
+
+tp-descriptor = tp-range / tp-number
+
+tp-range = tp-number "-" tp-number
+
+tp-number = tile-number "." part-number
+
+tile-number = UINT
+
+part-number = UINT
+
+;=====
+; C.8.4 Need for Stateless Requests (need)
+;=====
+
+need = "need" "=" 1#need-item
+
+need-item = [codestream-qualifier "," ] bin-descriptor
+
+;=====
+; C.8.5 Tile-part Need for Stateless Requests (tpneed)
+;=====
+
+tpneed = "tpneed" "=" 1#tpneed-item
+
+tpneed-item = [codestream-qualifier "," ] tp-descriptor
+
+```
+
+```
+
+;=====
+; C.8.6 Model Set for Requests within a session (mset)
+;=====
+
+mset = "mset" "=" 1#sampled-range
+
+;=====
+; C.9.1 Upload (upload)
+;=====
+
+upload = "upload" "=" upload-type
+upload-type = image-return-type ; C.7.3
+
+;=====
+; C.10.1 Client Capability (cap)
+;=====
+
+cap = "cap" "=" 1#capability-group
+capability-group = processing-capability
+                  / depth-capability
+                  / config-capability
+
+processing-capability = compatibility-capability
+                      / vendor-capability
+
+compatibility-capability = "cc." compatibility-code
+vendor-capability = "vc." vendor-code [":" vendor-value]
+vendor-code = 1*(LOWER / DIGIT / "." / "-")
+vendor-value = TOKEN
+
+depth-capability = "depth:" UINT
+config-capability = "config:" UINT
+
+;=====
+; C.10.2.1 General
+;=====
+
+pref = "pref" "=" 1#(related-pref-set ["/r"])
+related-pref-set = view-window-pref ; C.10.2.2
+                  / colour-meth-pref ; C.10.2.3
+                  / max-bandwidth ; C.10.2.4
+                  / bandwidth-slice ; C.10.2.5
+                  / placeholder-pref ; C.10.2.6
+                  / codestream-seq-pref ; C.10.2.7
+                  / conciseness-pref ; C.10.2.8
+                  / other
+
+other = TOKEN
+
+;=====
+; C.10.2.2 View-window handling preferences
+;=====
+
+view-window-pref = "fullwindow" / "progressive"
+
+;=====
+; C.10.2.3 Colour space method preference
+;=====
+
+color-meth-pref = 1$(color-meth [":" meth-limit])
+color-meth = "color-enum" / "color-ricc" / "color-icc" / "color-vend"
+meth-limit = UINT
+
+;=====
+; C.10.2.4 Max bandwidth
+;=====
+
+max-bandwidth = "mbw:" mbw
+mbw = UINT ["K" / "M" / "G" / "T"]
+
+```
+
+```
+
+;=====
+; C.10.2.5 Bandwidth slice
+;=====
+
+bandwidth-slice = "slice:" slice
+
+slice = NONZERO
+
+;=====
+; C.10.2.6 Placeholder preference
+;=====
+
+placeholder-pref = "meta:" placeholder-branch
+placeholder-branch = "incr" / "equiv" / "orig"
+
+;=====
+; C.10.2.7 Codestream sequencing
+;=====
+
+codestream-seq-pref = "codeseq:" codestream-seq-option
+codestream-seq-option = "sequential" / "reverse-sequential"
+                        / "interleaved"
+
+;=====
+; C.10.2.8 Conciseness preference
+;=====
+
+conciseness-pref = "loose" / "concise"
+
+;=====
+; C.10.3 Contrast sensitivity (csf)
+;=====
+
+csf = "csf" "=" 1#csf-sample-line
+csf-sample-line = csf-density [";" csf-angle] ";" 1$sensitivity
+csf-density = "density" ":" UFLOAT
+csf-angle = "angle" ":" UFLOAT
+sensitivity = UFLOAT
+
+;=====
+; C.10.4 Handled (handled)
+;=====
+
+handled = "handled"
+
+```
+
+## N.2 JPIP Response BNF
+
+```
+
+;=====
+; D.1.1 Reply structure
+;=====
+
+Status-Code = 3DIGIT
+
+Reason-Phrase = *<TEXT, excluding CR and LF>
+
+jpip-response-header =
+    / JPIP-tid                ; D.2.2
+    / JPIP-cnew               ; D.2.3
+    / JPIP-qid                ; D.2.4
+    / JPIP-fsiz               ; D.2.5
+    / JPIP-rsiz               ; D.2.6
+    / JPIP-roff               ; D.2.7
+    / JPIP-fvsiz              ; D.2.8
+    / JPIP-rvsiz              ; D.2.9
+    / JPIP-rvoff              ; D.2.10
+    / JPIP-comps              ; D.2.11
+    / JPIP-stream              ; D.2.12
+    / JPIP-context            ; D.2.13
+    / JPIP-roi                 ; D.2.14
+    / JPIP-layers              ; D.2.15
+    / JPIP-srate               ; D.2.16
+    / JPIP-metareq             ; D.2.17
+
+```
+
+```
+
+/ JPIP-len ; D.2.18
+/ JPIP-quality ; D.2.19
+/ JPIP-type ; D.2.20
+/ JPIP-mset ; D.2.21
+/ JPIP-cap ; D.2.22
+/ JPIP-pref ; D.2.23
+/ JPIP-align ; D.2.24
+/ JPIP-subtarget ; D.2.25
+/ JPIP-handled ; D.2.26
+
+;=====
+; D.2.2 Target ID (JPIP-tid)
+;=====
+
+JPIP-tid = "JPIP-tid" ":" LWSP target-id
+
+;=====
+; D.2.3 New Channel (JPIP-cnew)
+;=====
+
+JPIP-cnew = "JPIP-cnew" ":" LWSP "cid" "=" channel-id
+["," 1#(transport-param "=" TOKEN)]
+
+transport-param = TOKEN
+
+;=====
+; D.2.4 Request ID (JPIP-qid)
+;=====
+
+JPIP-qid = "JPIP-qid" ":" LWSP UINT
+
+;=====
+; D.2.5 Frame Size (JPIP-fsiz)
+;=====
+
+JPIP-fsiz = "JPIP-fsiz" ":" LWSP fx "," fy
+
+;=====
+; D.2.6 Region Size (JPIP-rsiz)
+;=====
+
+JPIP-rsiz = "JPIP-rsiz" ":" LWSP sx "," sy
+
+;=====
+; D.2.7 Offset (JPIP-roff)
+;=====
+
+JPIP-roff = "JPIP-roff" ":" LWSP ox "," oy
+
+;=====
+; D.2.8 Frame Size for Variable Dimension Data (JPIP-fvsiz)
+;=====
+
+JPIP-fvsiz = "JPIP-fvsiz" ":" LWSP 1#UINT
+
+;=====
+; D.2.9 Region Size for Variable Dimension Data (JPIP-rvsiz)
+;=====
+
+JPIP-rvsiz = "JPIP-rvsiz" ":" LWSP 1#UINT
+
+;=====
+; D.2.10 Offset for Variable Dimension Data (JPIP-rvoff)
+;=====
+
+JPIP-rvoff = "JPIP-rvoff" ":" LWSP 1#UINT
+
+;=====
+; D.2.11 Components (JPIP-comps)
+;=====
+
+JPIP-comps = "JPIP-comps" ":" LWSP 1#UINT-RANGE
+
+;=====
+; D.2.12 Codestream (JPIP-stream)
+;=====
+
+JPIP-stream = "JPIP-stream" ":" LWSP 1#(prefixed-range / sampled-range)
+
+```
+
+```
+
+prefixed-range = "<" ctxt-id ":" ctxt-elt ">" sampled-range
+ctxt-id = UINT
+ctxt-elt = UINT
+
+;=====
+; D.2.13 Codestream Context (JPIP-context)
+;=====
+
+JPIP-context = "JPIP-context" ":" LWSP 1$(context-range "=" 1#sampled-range)
+
+;=====
+; D.2.14 ROI (JPIP-roi)
+;=====
+
+JPIP-roi = "JPIP-roi" ":" LWSP
+           "roi" "=" region-name ";"
+           "fsiz" "=" UINT "," UINT ";"
+           "rsiz" "=" UINT "," UINT ";"
+           "roff" "=" UINT "," UINT ";"
+
+region-name = 1*(DIGIT / ALPHA / "_")
+
+;=====
+; D.2.15 Layers (JPIP-layers)
+;=====
+
+JPIP-layers = "JPIP-layers" ":" LWSP UINT
+
+;=====
+; D.2.16 Sampling Rate (JPIP-srate)
+;=====
+
+JPIP-srate = "JPIP-srate" ":" LWSP UFLOAT
+
+;=====
+; D.2.17 Metadata request (JPIP-metareq)
+;=====
+
+JPIP-metareq = "JPIP-metareq" ":" LWSP
+               1#( "[" 1$(req-box-prop) "]" [root-bin] [max-depth] )
+               [metadata-only]
+
+req-box-prop = box-type [limit] [metareq-qualifier] [priority]
+
+;=====
+; D.2.18 Maximum Response Length (JPIP-length)
+;=====
+
+JPIP-len = "JPIP-len" ":" LWSP UINT
+
+;=====
+; D.2.19 Quality (JPIP-quality)
+;=====
+
+JPIP-quality = "JPIP-quality" ":" LWSP (1*2DIGIT / "100" / "-1")
+
+;=====
+; D.2.20 Image Return Type (JPIP-type)
+;=====
+
+JPIP-type = "JPIP-type" ":" LWSP image-return-type
+
+;=====
+; D.2.21 Model Set (JPIP-mset)
+;=====
+
+JPIP-mset = "JPIP-mset" ":" LWSP 1#sampled-range
+
+;=====
+; D.2.22 Needed Capability (JPIP-cap)
+;=====
+
+JPIP-cap = "JPIP-cap" ":" LWSP 1#capability-code
+
+```
+
+```
+
+;=====
+; D.2.23 Unavailable Preference (JPIP-pref)
+;=====
+
+JPIP-pref = "JPIP-pref" ":" LWSP 1#related-pref-set
+
+;=====
+; D.2.24 Alignment (JPIP-align)
+;=====
+
+JPIP-align = "JPIP-align" ":" LWSP "yes" / "no"
+
+;=====
+; D.2.25 Subtarget (JPIP-subtarget)
+;=====
+
+JPIP-subtarget = "JPIP-subtarget" ":" LWSP byte-range / src-codestream-specs
+
+;=====
+; D.2.26 Handled request (JPIP-handled)
+;=====
+
+JPIP-handled = "JPIP-handled" ":" LWSP 1#handled-req
+handled-req = (request-field | partially-handled-req)
+partially-handled-req = request-field "=" handled-req-option
+request-field = TOKEN
+handled-req-option = TOKEN
+
+```
+
+## Annex O
+
+### Media type specifications and registrations
+
+(This annex does not form an integral part of this Recommendation | International Standard.)
+
+#### O.1 General
+
+Many Internet protocols are designed to carry arbitrary labelled content. The mechanism used to label such content is a media type, which is defined in IETF RFC 6838 and consists of a top-level type, a subtype, and in some instances, optional parameters.
+
+The media type specifications of the following clauses have a matching registration in the IANA central registry, as specified in IETF RFC 6838.
+
+#### O.2 JPP-stream
+
+##### O.2.1 General
+
+The `image/jpp-stream` media type refers to content that consists of a sequence of JPIP messages whose class identifiers are limited to those listed in Table A.2 as compatible with the JPP-stream type.
+
+##### O.2.2 Registration
+
+Type name: image
+
+Subtype name: jpp-stream
+
+Required parameters: None
+
+Optional parameters: ptype=ext
+
+Encoding considerations: binary
+
+Security considerations: a jpp-stream contains structures of variable length and an extensible syntax. Both of these aspects present potential security risks for implementations. In particular, variable length structures present buffer overflow risks and extensible syntax could result in the triggering of adverse actions.
+
+Interoperability considerations: jpp-stream media is self-describing and may be used to describe one or more JPEG 2000 codestreams, or parts thereof, along with arbitrary elements from JPEG 2000 family file formats that may contain those codestreams. Readers need to be prepared to receive and interpret fragments of precincts from an original JPEG 2000 codestream.
+
+Published specification: Rec. ITU-T T.808 | ISO/IEC 15444-9
+
+Applications: Multimedia and scientific
+
+Fragment identifier considerations: None
+
+Restrictions on usage: None
+
+Provisional registration: Yes
+
+Additional information: None
+
+Magic number(s): None
+
+File extension(s): jpp
+
+Macintosh File Type Code(s): N/A
+
+Object Identifiers: N/A
+
+Contact name: ISO/IEC JTC 1/SC 29/WG 1 Convenor
+
+Contact email address: sc29-sec@itscj.ipsj.or.jp
+
+Intended usage: COMMON
+
+Change controller: ITU-T & ISO/IEC JTC 1
+
+## O.3 JPT-stream
+
+### O.3.1 General
+
+The image/jpt-stream media type refers to content that consists of sequence of JPIP messages whose class identifiers are limited to those listed in Table A.2 as compatible with the JPT-stream type.
+
+### O.3.2 Registration
+
+Type name: image
+
+Subtype name: jpt-stream
+
+Required parameters: None
+
+Optional parameters: ttype=ext
+
+Encoding considerations: binary
+
+Security considerations: a jpt-stream contains structures of variable length and an extensible syntax. Both of these aspects present potential security risks for implementations. In particular, variable length structures present buffer overflow risks and extensible syntax could result in the triggering of adverse actions.
+
+Interoperability considerations: jpt-stream media is self-describing and may be used to describe one or more JPEG 2000 codestreams, or parts thereof, along with arbitrary elements from JPEG 2000 family file formats that may contain those codestreams. Readers need to be prepared to receive and interpret fragments of tiles from an original JPEG 2000 codestream.
+
+Published specification: Rec. ITU-T T.808 | ISO/IEC 15444-9
+
+Applications: Multimedia and scientific
+
+Fragment identifier considerations: None
+
+Restrictions on usage: None
+
+Provisional registration: Yes
+
+Additional information: None
+
+Magic number(s): None
+
+File extension(s): jpt
+
+Macintosh File Type Code(s): N/A
+
+Object Identifiers: N/A
+
+Contact name: ISO/IEC JTC 1/SC 29/WG 1 Convenor
+
+Contact email address: sc29-sec@itscj.ipsj.or.jp
+
+Intended usage: COMMON
+
+Change controller: ITU-T & ISO/IEC JTC 1
+
+## Bibliography
+
+- [1] Taubman, D., Remote Browsing of JPEG 2000 Images, *Proc. Int. Conf. on Image Processing*, Vol. 1, pp. 229-232, Sept. 2002.
+- [2] Li, J., Sun, H., Li, H., Zhang, Q., Lin, X., Vfile – A Virtual File Media Access Mechanism and its Application in JPEG2000 Images for Browsing over Internet, *ISO/IEC JTC 1/SC 29/WG 1 Document Register: N1473*, Nov. 1999.
+- [3] Boliek, M., Wu, G.K., Gormish, M.J., JPEG 2000 for Efficient Imaging in a Client/Server Environment, *Proc. SPIE Conf. on Applications of Digital Image Processing*, Vol. 4472, pp. 212-223, Dec. 2001.
+- [4] Deshpande, S., Zeng, W., Scalable Streaming of JPEG2000 Images Using Hypertext Transfer Protocol, *Proc. ACM Conf. on Multimedia*, pp. 372-381, Oct. 2001.
+- [5] Wright, A., Clark, R., Colyer, G., An Implementation of JPIP Based on HTTP, *ISO/IEC JTC 1/SC 29/WG 1 Document Register: N2426*, Feb. 2002.
+- [6] Gormish, M., Banerjee, S., Tile-Based Transport of JPEG 2000, N. Garcia, J.M. Martinez, L. Salgado (Eds.), VLVB03, LNCS 2849, pp. 217-224, 2003.
+- [7] Taubman, D., Rosenbaum, R., Rate-Distortion Optimized Interactive Browsing of JPEG2000 Images, *Proc. Int. Conf. on Image Processing*, Sept. 2003.
+- [8] Taubman, D., Prandolini, (R.): Architecture, Philosophy and Performance of JPIP: Internet Protocol Standard for JPEG2000, presented at *Visual Communications and Image Processing*, Lugano, Switzerland, 2003.
+- [9] Gormish, M.J., Truew, Transport of Reversible and Unreversible Embedded Wavelets (A JPIP Proposal), *ISO/IEC JTC 1/SC 29/WG 1 Document Register: N2602*, July 2002.
+- [10] Canon: Proposal for JPIP Tier 2 protocol, *ISO/IEC JTC 1/SC 29/WG 1 Document Register: N2608*, June 2002.
+- [11] Taubman, D., Marcellin, M., JPEG2000: image compression fundamentals, standards and practice, *Kluwer Academic Publishers*, Boston, 2001.
+- [12] Richter, Th., Brower, B., Martucci, S., and Tzannes, A. (2009), *Interoperability in JPIP and its Standardization in JPEG 2000*, Part 9, In: A. Tescher (Ed.): *Applications of Digital Image Processing XXXII*, Proc. SPIE 2009.
+- [13] Recommendation ITU-T T.804 | ISO/IEC 15444-5, *Information technology – JPEG 2000 image coding system: Reference software*.
+
+
+
+## SERIES OF ITU-T RECOMMENDATIONS
+
+|                 |                                                                                                                                                           |
+|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Series A        | Organization of the work of ITU-T                                                                                                                         |
+| Series D        | Tariff and accounting principles and international telecommunication/ICT economic and policy issues                                                       |
+| Series E        | Overall network operation, telephone service, service operation and human factors                                                                         |
+| Series F        | Non-telephone telecommunication services                                                                                                                  |
+| Series G        | Transmission systems and media, digital systems and networks                                                                                              |
+| Series H        | Audiovisual and multimedia systems                                                                                                                        |
+| Series I        | Integrated services digital network                                                                                                                       |
+| Series J        | Cable networks and transmission of television, sound programme and other multimedia signals                                                               |
+| Series K        | Protection against interference                                                                                                                           |
+| Series L        | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant |
+| Series M        | Telecommunication management, including TMN and network maintenance                                                                                       |
+| Series N        | Maintenance: international sound programme and television transmission circuits                                                                           |
+| Series O        | Specifications of measuring equipment                                                                                                                     |
+| Series P        | Telephone transmission quality, telephone installations, local line networks                                                                              |
+| Series Q        | Switching and signalling, and associated measurements and tests                                                                                           |
+| Series R        | Telegraph transmission                                                                                                                                    |
+| Series S        | Telegraph services terminal equipment                                                                                                                     |
+| <b>Series T</b> | <b>Terminals for telematic services</b>                                                                                                                   |
+| Series U        | Telegraph switching                                                                                                                                       |
+| Series V        | Data communication over the telephone network                                                                                                             |
+| Series X        | Data networks, open system communications and security                                                                                                    |
+| Series Y        | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities                               |
+| Series Z        | Languages and general software aspects for telecommunication systems                                                                                      |
\ No newline at end of file
diff --git a/marked/T/T-REC-T.810-200605-I_PDF-E/raw.md b/marked/T/T-REC-T.810-200605-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..71c554dc6c7640cc3151def6693cbd6a98bc92cd
--- /dev/null
+++ b/marked/T/T-REC-T.810-200605-I_PDF-E/raw.md
@@ -0,0 +1,2054 @@
+
+
+I n t e r n a t i o n a l   T e l e c o m m u n i c a t i o n   U n i o n
+
+**ITU-T**
+
+TELECOMMUNICATION  
+STANDARDIZATION SECTOR  
+OF ITU
+
+**T.810**
+
+(05/2006)
+
+SERIES T: TERMINALS FOR TELEMATIC SERVICES
+
+---
+
+# **Information technology – JPEG 2000 image coding system: Wireless**
+
+ITU-T Recommendation T.810
+
+
+
+# **Information technology – JPEG 2000 image coding system: Wireless**
+
+# **Summary**
+
+The purpose of this Recommendation | International Standard is to provide a syntax that allows to protect JPEG 2000 coded image data for transmission over wireless channels and networks. Protection services include error detection and correction capability for header and bitstream, a description of the error sensitivity of different portions of the compressed data, and a description of possible residual errors in the compressed data. The syntax allows these protection services to be applied to coded image data in part or in their entirety. These services are designed so as to maintain the inherent features of JPEG 2000, such as scalability and access to various spatial areas, resolution levels, colour components, and quality layers, while providing protection services on these elements.
+
+## **Source**
+
+ITU-T Recommendation T.810 was approved on 29 May 2006 by ITU-T Study Group 16 (2005-2008) under the ITU-T Recommendation A.8 procedure. An identical text is also published as ISO/IEC 15444-11.
+
+# FOREWORD
+
+The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis.
+
+The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics.
+
+The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1.
+
+In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC.
+
+## NOTE
+
+In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure e.g. interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party.
+
+## INTELLECTUAL PROPERTY RIGHTS
+
+ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process.
+
+As of the date of approval of this Recommendation, ITU had received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database.
+
+© ITU 2007
+
+All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU.
+
+# CONTENTS
+
+|                                                                                                    | <i>Page</i> |
+|----------------------------------------------------------------------------------------------------|-------------|
+| 1 Scope                                                                                            | 1           |
+| 2 Normative references                                                                             | 1           |
+| 3 Terms and definitions                                                                            | 1           |
+| 4 Symbols and abbreviated terms                                                                    | 3           |
+| 4.1 Abbreviations                                                                                  | 3           |
+| 4.2 Symbols                                                                                        | 3           |
+| 5 JPWL general description                                                                         | 4           |
+| 5.1 Introduction                                                                                   | 4           |
+| 5.2 JPWL system description                                                                        | 5           |
+| 6 JPWL normative parts                                                                             | 7           |
+| 7 JPWL informative parts                                                                           | 7           |
+| Annex A – Codestream syntax                                                                        | 8           |
+| A.1 Definitions of markers and marker segments                                                     | 8           |
+| A.2 Marker code range defined in this Recommendation   International Standard                      | 8           |
+| A.3 Marker and marker segment and codestream rules                                                 | 8           |
+| A.4 Information in the marker segments                                                             | 8           |
+| A.5 Construction of the codestream                                                                 | 9           |
+| A.6 JPWL marker segments                                                                           | 9           |
+| Annex B – Header error protection                                                                  | 17          |
+| B.1 Introduction                                                                                   | 17          |
+| B.2 Predefined error-correction codes                                                              | 18          |
+| B.3 Use of EPB for header protection                                                               | 18          |
+| Annex C – Error protection capability                                                              | 22          |
+| C.1 Usage of the EPC marker segment                                                                | 22          |
+| C.2 $P_{CRC}$                                                                                      | 22          |
+| C.3 Data length (DL)                                                                               | 22          |
+| C.4 $P_{EPC}$                                                                                      | 23          |
+| C.5 Identification of tools (ID)                                                                   | 23          |
+| C.6 Parameters for tools ( $P_{ID}$ )                                                              | 23          |
+| Annex D – Error sensitivity descriptor                                                             | 24          |
+| D.1 Introduction and applications                                                                  | 24          |
+| D.2 Marker definition and position in the codestream                                               | 24          |
+| D.3 Codestream subdivision into data units                                                         | 25          |
+| D.4 Sensitivity information                                                                        | 25          |
+| D.5 Examples and guidelines                                                                        | 27          |
+| Annex E – Residual errors descriptor                                                               | 29          |
+| E.1 Introduction                                                                                   | 29          |
+| E.2 Signalling of residual errors                                                                  | 29          |
+| E.3 Examples                                                                                       | 30          |
+| Annex F – Guidelines for encoding JPEG 2000 codestreams in the context of error-prone environments | 31          |
+| F.1 Introduction                                                                                   | 31          |
+| F.2 JPEG 2000 Part 1 error-resilience tools                                                        | 31          |
+| F.3 JPEG 2000 encoder implementation guidelines                                                    | 31          |
+| Annex G – Recommended decoder error handling behaviour                                             | 33          |
+| G.1 Introduction                                                                                   | 33          |
+| G.2 JPEG 2000 Part 1 decoder recommended behaviour                                                 | 33          |
+| G.3 JPWL decoder implementation guidelines                                                         | 34          |
+
+|                                                                                                       | <i>Page</i> |
+|-------------------------------------------------------------------------------------------------------|-------------|
+| Annex H – Error-resilient entropy coding .....                                                        | 36          |
+| H.1 Introduction .....                                                                                | 36          |
+| H.2 Syntax .....                                                                                      | 36          |
+| H.3 Binary encoding with forbidden symbol .....                                                       | 37          |
+| H.4 Error-resilience segmentation symbols .....                                                       | 38          |
+| H.5 Error detection.....                                                                              | 39          |
+| H.6 Error correction .....                                                                            | 40          |
+| Annex I – Unequal error protection .....                                                              | 45          |
+| I.1 Introduction .....                                                                                | 45          |
+| I.2 Use of error-sensitivity descriptor as input information to unequal error-protection systems..... | 45          |
+| I.3 Use of Error Protection Block (EPB) for unequal error protection.....                             | 45          |
+| Annex J – Interoperability with ISO/IEC 15444 .....                                                   | 46          |
+| J.1 Interoperability with ISO/IEC 15444-1 .....                                                       | 46          |
+| J.2 Interoperability with ISO/IEC 15444-3 .....                                                       | 46          |
+| J.3 Interoperability with ISO/IEC 15444-8 (JPSEC) .....                                               | 46          |
+| Annex K – Registration authority .....                                                                | 48          |
+| K.1 General introduction .....                                                                        | 48          |
+| K.2 Criteria for eligibility of applicants for registration .....                                     | 48          |
+| K.3 Applications for registration .....                                                               | 48          |
+| K.4 Review and response to applications .....                                                         | 49          |
+| K.5 Maintenance .....                                                                                 | 50          |
+| K.6 Publication of the register .....                                                                 | 50          |
+| Annex L – Patent statement.....                                                                       | 51          |
+| BIBLIOGRAPHY .....                                                                                    | 52          |
+
+# INTERNATIONAL STANDARD ITU-T RECOMMENDATION
+
+# Information technology – JPEG 2000 image coding system: Wireless
+
+# 1 Scope
+
+This Recommendation | International Standard defines, in an extensible manner, syntaxes and methods for the protection against errors that may occur during the transmission of JPEG 2000 codestreams compliant with ITU-T Rec. T.800 | ISO/IEC 15444-1.
+
+In this Recommendation | International Standard, these are referred to as Wireless JPEG 2000, "JPWL", and applications using JPWL are referred to as a "JPWL system".
+
+JPWL specifies a set of tools consisting of additional data structures to JPEG 2000 codestreams and error protection techniques, necessary for error correction and signalling. This Recommendation | International Standard includes definitions of the semantics, and suggests how these may be used.
+
+# 2 Normative references
+
+The following Recommendations and International Standards contain provisions which, through reference in this text, constitute provisions of this Recommendation | International Standard. At the time of publication, the editions indicated were valid. All Recommendations and Standards are subject to revision, and parties to agreements based on this Recommendation | International Standard are encouraged to investigate the possibility of applying the most recent edition of the Recommendations and Standards listed below. Members of IEC and ISO maintain registers of currently valid International Standards. The Telecommunication Standardization Bureau of the ITU maintains a list of currently valid ITU-T Recommendations.
+
+- ITU-T Recommendation T.800 (2002) | ISO/IEC 15444-1:2004, *Information technology – JPEG 2000 image coding system: Core coding system*.
+
+# 3 Terms and definitions
+
+For the purposes of this Recommendation | International Standard, the following terms and definitions apply. The definitions defined in ITU-T Rec. T.800 | ISO/IEC 15444-1 clause 3 apply to this Recommendation | International Standard.
+
+- 3.1 backward compatible:** Includes all techniques that produce a bitstream that will lead the Part-1 decoder to decode/display according to JPEG 2000 Part 4 (ITU-T Rec. T.803 | ISO/IEC 15444-4) specifications in case of error-free environment.
+- 3.2 backward compatible with extensions:** Includes all techniques that produce a bitstream that will not lead the Part-1 decoder to crash in case of error-free environment. A JPWL decoder is required to correctly decode/display images.
+- 3.3 big endian:** The bits of a value representation occur in order from most significant to least significant.
+- 3.4 bitstream:** The sequence of bits resulting from the coding of a sequence of symbols. It does not include the markers or marker segments in the main and tile-part headers or the EOC marker. It does include any packet headers and in stream markers and marker segments not found within the main or tile-part headers.
+- 3.5 Bit Error Rate (BER):** The BER is defined as the statistical expected value of the ratio between the number of erroneous bits in the received data and the size of the received data themselves.
+- 3.6 code-block:** A rectangular grouping of coefficients from the same subband of a tile-component.
+- 3.7 codestream:** A collection of one or more bit streams and the main header, tile-part headers, and the EOC required for their decoding and expansion into image data. This is the image data in a compressed form with all of the signalling needed to decode.
+
+- 3.8 data partitioning:** Data partitioning is a modification of the organization of the codestream, with a separation of the compressed data in different parts.
+- 3.9 decoder:** An embodiment of a decoding process, and optionally a colour transformation process.
+- 3.10 decoding process:** A process which takes as its input all or part of a codestream and outputs all or part of a reconstructed image.
+- 3.11 encoder:** An embodiment of an encoding process.
+- 3.12 encoding process:** A process that takes as its input all or part of a source image data and outputs a codestream.
+- 3.13 Forward Error Correction (FEC):** The FEC consists of any techniques aiming at providing error detection and/or correction capability by adding redundancy to the codestream.
+- 3.14 interleaving:** Interleaving is a modification of the data ordering of a codestream.
+- 3.15 JPWL Registration Authority:** An organization that is in charge of delivering a unique ID to reference a JPWL tool and storing the parameter list of its description.
+- 3.16 layer:** A collection of compressed image data from coding passes of one, or more, code-blocks of a tile-component. Layers have an order for encoding and decoding that must be preserved.
+- 3.17 little endian:** The bits of a value representation occur in order from least significant to most significant.
+- 3.18 marker:** A two-byte code in which the first byte is hexadecimal FF (0xFF) and the second byte is a value between 1 (0x01) and hexadecimal FE (0xFE).
+- 3.19 marker segment:** A marker and associated (not empty) set of parameters.
+- 3.20 non-backward compatible:** Includes all techniques that produce a bitstream that may lead the JPEG 2000 Part 1 decoder to crash also in case of error-free environment. This kind of technique is outside of the scope of this Recommendation | International Standard.
+- 3.21 packet:** A part of the bitstream comprising a packet header and the compressed image data from one layer of one precinct of one resolution level of one tile-component.
+- 3.22 packet header:** Portion of the packet that contains signalling necessary for decoding that packet.
+- 3.23 Packet Loss Rate (PLR):** The PLR is defined as the statistical expected value of the ratio between the number of packets discarded during the transmission, and the number of packets sent during the transmission. Within this definition, it is intended that a packet is considered at transmission level, and not as a basic entity of a JPEG 2000 codestream.
+- 3.24 pointer markers and pointer marker segments:** Markers and marker segments that offer information about the location of structures in the codestream.
+- 3.25 precinct:** A rectangular region of a transformed tile-component, within each resolution level, used for limiting the size of packets.
+- 3.26 precision:** Number of bits allocated to a particular sample, coefficient, or other binary numerical representation.
+- 3.27 systematic codes:** A systematic code is one that produces a given number of redundancy symbols in addition to the original input data symbols.
+- 3.28 tile:** A rectangular array of points on the reference grid, registered with and offset from the reference grid origin and defined by a width and height. The tiles which overlap are used to define tile-components.
+- 3.29 tile-component:** All the samples of a given component in a tile.
+- 3.30 tile index:** The index of the current tile ranging from zero to the number of tiles minus one.
+- 3.31 tile-part:** A portion of the codestream with compressed image data for some, or all, of a tile. The tile-part includes at least one, and up to all, of the packets that make up the coded tile.
+- 3.32 tile-part header:** A group of markers and marker segments at the beginning of each tile-part in the codestream that describe the tile-part coding parameters.
+- 3.33 transcoder:** An embodiment of a transcoding process.
+
+**3.34 transcoding process:** A process which takes as its input all or part of a codestream and outputs all or parts of it, together with the possible addition of other data.
+
+**3.35 Unequal Error Protection (UEP):** UEP refers to the act of assigning different degrees of error protection to different parts of a codestream.
+
+# 4 Symbols and abbreviated terms
+
+## 4.1 Abbreviations
+
+For the purposes of this Recommendation | International Standard, the following abbreviations apply.
+
+|                   |                                                                                                                                                                                                                                                                            |
+|-------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| ITU               | International Telecommunication Union                                                                                                                                                                                                                                      |
+| ITU-T             | International Telecommunication Union – Telecommunication Standardization Sector (formerly the CCITT)                                                                                                                                                                      |
+| JPEG              | Joint Photographic Experts Group – The joint ISO/IEC/ITU committee responsible for developing standards for continuous-tone still picture coding. It also refers to the standards produced by this committee: ISO/IEC 10918 and their corresponding ITU-T Recommendations. |
+| JPEG 2000         | Joint Photographic Experts Group – The joint ISO/IEC/ITU committee responsible for developing standards for continuous-tone still picture coding. It also refers to the standards produced by this committee: ISO/IEC 15444 and their corresponding ITU-T Recommendations. |
+| JPEG 2000 Part 1  | Refers to Part 1 of JPEG 2000, ITU-T Rec. T.800   ISO/IEC 15444-1.                                                                                                                                                                                                         |
+| JPEG 2000 Part 11 | Refers to this Recommendation   International Standard.                                                                                                                                                                                                                    |
+| JPWL              | Refers to this Recommendation   International Standard.                                                                                                                                                                                                                    |
+| RA                | Registration Authority                                                                                                                                                                                                                                                     |
+
+## 4.2 Symbols
+
+For the purposes of this Recommendation | International Standard, the following symbols apply.
+
+|                 |                                                                                                                                                                           |
+|-----------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| 0x----          | Denotes a hexadecimal number.                                                                                                                                             |
+| \nnn            | A three-digit number preceded by a backslash indicates the value of a single byte within a character string, where the three digits specify the octal value of that byte. |
+| $\varepsilon_b$ | Exponent of the error sensitivity value defined in ESD                                                                                                                    |
+| $\mu_b$         | Mantissa of the error sensitivity value defined in ESD                                                                                                                    |
+| BCH             | Bose-Chaudhuri-Hocquenghem                                                                                                                                                |
+| COC             | Coding style component marker                                                                                                                                             |
+| COD             | Coding style default marker                                                                                                                                               |
+| COM             | Comment marker                                                                                                                                                            |
+| CRC             | Cyclic Redundancy Check                                                                                                                                                   |
+| CRG             | Component Registration Marker                                                                                                                                             |
+| EOC             | End of Codestream marker                                                                                                                                                  |
+| EPB             | Error Protection Block marker                                                                                                                                             |
+| EPC             | Error Protection Capability marker                                                                                                                                        |
+| EPH             | End of Packet Header marker                                                                                                                                               |
+| ESD             | Error Sensitivity Descriptor marker                                                                                                                                       |
+| FEC             | Forward Error Correction                                                                                                                                                  |
+
+###### ISO/IEC 15444-11:2006 (E)
+
+|     |                                                |
+|-----|------------------------------------------------|
+| PLM | Packet Length, Main header marker              |
+| PLT | Packet Length, Tile-part header marker         |
+| POC | Progression Order Change marker                |
+| PPM | Packed Packet headers, Main header marker      |
+| PPT | Packed Packet headers, Tile-part header marker |
+| QCC | Quantization Component marker                  |
+| QCD | Quantization Default marker                    |
+| RED | Residual Error Descriptor marker               |
+| RGN | Region of interest marker                      |
+| RS  | Reed Solomon                                   |
+| SIZ | Image and tile size marker                     |
+| SOC | Start of Codestream marker                     |
+| SOD | Start of Data marker                           |
+| SOP | Start of Packet marker                         |
+| SOT | Start of Tile-part marker                      |
+| TLM | Tile-part Lengths Marker                       |
+| UEP | Unequal Error Protection                       |
+
+# 5 JPWL general description
+
+## 5.1 Introduction
+
+This Recommendation | International Standard defines a set of tools and methods to achieve the efficient transmission of JPEG 2000 Part 1 imagery over an error-prone transmission/storage environment. The main target of this Recommendation | International Standard is wireless applications, although the same tools can be employed in other types of applications, which are prone to errors.
+
+Wireless networks are characterized by the frequent occurrence of transmission errors, henceforth putting strong constraints on the transmission of digital images. Since JPEG 2000 provides high compression efficiency, it is a good candidate for wireless multimedia applications. Moreover, due to its high scalability, JPEG 2000 enables a wide range of quality of service strategies for network operators. However, to be suitable for wireless multimedia applications, JPEG 2000 has to be robust to transmission errors.
+
+ITU-T Rec. T.800 | ISO/IEC 15444-1 defines error-resilience tools to improve performances over noisy channels. However, these tools can only detect occurrences of errors in the bitstream, conceal the erroneous data, and resynchronize the decoder. More specifically, they do not correct transmission errors. Furthermore, these tools do not apply to the main and tile-part headers which are the most important parts of the codestream. For these reasons, they are not sufficient in the context of wireless transmissions.
+
+For the purpose of efficient transmission over error-prone transmission/storage environments, this Recommendation | International Standard defines additional mechanisms for error protection and correction. These mechanisms extend the elements in the core coding system described in ITU-T Rec. T.800 | ISO/IEC 15444-1. These extensions are backward compatible or backward compatible with extensions, as specified in clause 3.
+
+This Recommendation | International Standard is not linked to a specific network or transport protocol, but provides a general solution for the robust transmission of JPEG 2000 imagery over error-prone channels and networks. JPWL would normally act at the application level. However, if appropriate, the JPWL tools can be used for direct transmission of images on the channel physical layer.
+
+## 5.2 JPWL system description
+
+The main functionalities of the JPWL system are to protect the codestream against transmission errors, to describe the degree of sensitivity to transmission errors of different parts of the codestream, and to describe the locations of residual errors in the codestream.
+
+The JPWL system can either be applied to an input source image or to a Part 1 codestream, as is illustrated in Figures 1 and 2 respectively. In Figure 1, at the transmission side, a JPWL encoder consists of three modules running concurrently: a JPEG 2000 Part 1 encoder compressing the input image, a generator of the error sensitivity description, and a processor applying the error protection tool. The result is a JPEG 2000 Part 11 codestream robust to transmission errors. At the receiving side, a JPWL decoder is also composed of three modules: a processor to correct errors, a generator of the residual errors description and a JPEG 2000 Part 1 decoder. Alternatively, in Figure 2 at the transmission side a JPWL transcoder processes a JPEG 2000 Part 1 codestream, generating the error sensitivity description and applying error protection tools. At the receiving side, a JPWL transcoder corrects the transmission errors and generate the residual errors description, producing a Part 1 codestream which can be sent to a Part 1 decoder, along with residual errors information.
+
+![Figure 1: JPWL system description: JPWL encoder and decoder. A block diagram showing the flow from an input image through a JPWL encoder (containing JPEG 2000 part 1 encoder, error sensitivity, and error protection modules) to a part 11 codestream. This codestream passes through an error-prone wireless channel to become a part 11 codestream with possible errors, which then enters a JPWL decoder (containing error protection, residual errors, and JPEG 2000 part 1 decoder modules) to produce an output decoded image.](d26959f4514c26ca19c3d6f00da85956_img.jpg)
+
+```
+
+graph LR
+    Input[input image] --> JPWL_Enc
+    subgraph JPWL_Enc [JPWL encoder]
+        J2K_Enc[JPEG 2000 part 1 encoder]
+        Err_Sens[error sensitivity]
+        Err_Prot[error protection]
+    end
+    JPWL_Enc --> P11_CS[part 11 codestream]
+    P11_CS --> Wireless[error-prone wireless channel]
+    Wireless -- "T.810(06)_F01" --> P11_Err[part 11 codestream with possible errors]
+    P11_Err --> JPWL_Dec
+    subgraph JPWL_Dec [JPWL decoder]
+        Err_Prot_D[error protection]
+        Res_Err[residual errors]
+        J2K_Dec[JPEG 2000 part 1 decoder]
+    end
+    JPWL_Dec --> Output[output decoded image]
+
+```
+
+Figure 1: JPWL system description: JPWL encoder and decoder. A block diagram showing the flow from an input image through a JPWL encoder (containing JPEG 2000 part 1 encoder, error sensitivity, and error protection modules) to a part 11 codestream. This codestream passes through an error-prone wireless channel to become a part 11 codestream with possible errors, which then enters a JPWL decoder (containing error protection, residual errors, and JPEG 2000 part 1 decoder modules) to produce an output decoded image.
+
+**Figure 1 – JPWL system description: JPWL encoder and decoder**
+
+![Figure 2: JPWL system description: JPWL transcoder. A block diagram showing a part 1 codestream entering a JPWL transcoder (with error sensitivity and error protection modules) to produce a part 11 codestream. This passes through an error-prone wireless channel to become a part 11 codestream with possible errors, which then enters a second JPWL transcoder (with error correction and residual errors modules) to output a part 1 codestream and residuals.](5e92d9e8e9ce204e405bff2367f88176_img.jpg)
+
+```
+
+graph LR
+    P1_CS_In[part 1 codestream] --> JPWL_Trans1
+    subgraph JPWL_Trans1 [JPWL transcoder]
+        Err_Sens_T1[error sensitivity]
+        Err_Prot_T1[error protection]
+    end
+    JPWL_Trans1 --> P11_CS[part 11 codestream]
+    P11_CS --> Wireless[error-prone wireless channel]
+    Wireless -- "T.810(06)_F02" --> P11_Err[part 11 codestream with possible errors]
+    P11_Err --> JPWL_Trans2
+    subgraph JPWL_Trans2 [JPWL transcoder]
+        Err_Corr_T2[error correction]
+        Res_Err_T2[residual errors]
+    end
+    JPWL_Trans2 --> P1_CS_Out[part 1 codestream]
+    JPWL_Trans2 -.-> Residuals[residuals]
+
+```
+
+Figure 2: JPWL system description: JPWL transcoder. A block diagram showing a part 1 codestream entering a JPWL transcoder (with error sensitivity and error protection modules) to produce a part 11 codestream. This passes through an error-prone wireless channel to become a part 11 codestream with possible errors, which then enters a second JPWL transcoder (with error correction and residual errors modules) to output a part 1 codestream and residuals.
+
+**Figure 2 – JPWL system description: JPWL transcoder**
+
+Other similar configurations are also possible as illustrated in Figures 3 and 4. Whereas in Figures 1 and 2 the generation of the error sensitivity description and the application of the error protection tool are concurrent, in Figures 3 and 4 the two operations are performed successively. More precisely, in a first step, a JPWL encoder/transcoder produces a JPEG 2000 Part 11 codestream containing error sensitivity information. In a second step, a JPWL transcoder uses this information to optimize the error protection tool, generating a JPEG 2000 Part 11 codestream robust to transmission errors.
+
+![Figure 3: JPWL system description: another configuration. This block diagram shows the flow from an input image through a JPWL encoder (containing a JPEG 2000 part 1 encoder and error sensitivity) to a JPWL transcoder (containing error protection). The output is a part 11 codestream, which passes through an error-prone wireless channel (labeled T.810(06)_F03) to become a part 11 codestream with possible errors. This is then processed by a JPWL decoder (containing a JPEG 2000 part 1 decoder, residual errors, and error correction) to produce an output decoded image.](007b053fe94a8348f75128a584503fd0_img.jpg)
+
+```
+
+graph LR
+    Input[input image] --> JPWL_encoder[JPWL encoder]
+    subgraph JPWL_encoder [JPWL encoder]
+        J2K[JPEG 2000 part 1 encoder]
+        ES[error sensitivity]
+    end
+    JPWL_encoder -- "part 11 codestream" --> JPWL_transcoder[JPWL transcoder]
+    subgraph JPWL_transcoder [JPWL transcoder]
+        EP[error protection]
+    end
+    JPWL_transcoder -- "part 11 codestream" --> Channel[error-prone wireless channel]
+    Channel -- "T.810(06)_F03" --> Errors["part 11 codestream with possible errors"]
+    Errors --> JPWL_decoder[JPWL decoder]
+    subgraph JPWL_decoder [JPWL decoder]
+        J2K_dec[JPEG 2000 part 1 decoder]
+        RE[residual errors]
+        EC[error correction]
+    end
+    JPWL_decoder --> Output[output decoded image]
+  
+```
+
+Figure 3: JPWL system description: another configuration. This block diagram shows the flow from an input image through a JPWL encoder (containing a JPEG 2000 part 1 encoder and error sensitivity) to a JPWL transcoder (containing error protection). The output is a part 11 codestream, which passes through an error-prone wireless channel (labeled T.810(06)\_F03) to become a part 11 codestream with possible errors. This is then processed by a JPWL decoder (containing a JPEG 2000 part 1 decoder, residual errors, and error correction) to produce an output decoded image.
+
+Figure 3 – JPWL system description: another configuration
+
+![Figure 4: JPWL system description: another configuration. This block diagram shows a part 1 codestream entering a JPWL transcoder (containing error sensitivity), which outputs a part 11 codestream. This codestream enters another JPWL transcoder (containing error protection) and outputs a part 11 codestream. This codestream passes through an error-prone wireless channel (labeled T.810(06)_F04) to become a part 11 codestream with possible errors. This is then processed by a JPWL transcoder (containing residual errors and error correction) to produce a part 1 codestream and residuals.](27b06ec9f42b5d727a2630f61a5f1861_img.jpg)
+
+```
+
+graph LR
+    Input["part 1 codestream"] --> JPWL_transcoder1[JPWL transcoder]
+    subgraph JPWL_transcoder1 [JPWL transcoder]
+        ES[error sensitivity]
+    end
+    JPWL_transcoder1 -- "part 11 codestream" --> JPWL_transcoder2[JPWL transcoder]
+    subgraph JPWL_transcoder2 [JPWL transcoder]
+        EP[error protection]
+    end
+    JPWL_transcoder2 -- "part 11 codestream" --> Channel[error-prone wireless channel]
+    Channel -- "T.810(06)_F04" --> Errors["part 11 codestream with possible errors"]
+    Errors --> JPWL_transcoder3[JPWL transcoder]
+    subgraph JPWL_transcoder3 [JPWL transcoder]
+        RE[residual errors]
+        EC[error correction]
+    end
+    JPWL_transcoder3 -- "part 1 codestream" --> Output1[part 1 codestream]
+    JPWL_transcoder3 -.-> Residuals[residuals]
+  
+```
+
+Figure 4: JPWL system description: another configuration. This block diagram shows a part 1 codestream entering a JPWL transcoder (containing error sensitivity), which outputs a part 11 codestream. This codestream enters another JPWL transcoder (containing error protection) and outputs a part 11 codestream. This codestream passes through an error-prone wireless channel (labeled T.810(06)\_F04) to become a part 11 codestream with possible errors. This is then processed by a JPWL transcoder (containing residual errors and error correction) to produce a part 1 codestream and residuals.
+
+Figure 4 – JPWL system description: another configuration
+
+The error protection process modifies the codestream to make it more resilient to errors, e.g., by adding redundancy or by partitioning and interleaving the data. The error correction process detects the occurrence of errors and corrects them whenever possible. Techniques to protect the codestream include Forward Error Correcting (FEC) codes, data partitioning and interleaving, robust entropy coding, and unequal error protection.
+
+The error sensitivity descriptor describes the degree of sensitivity of different parts of the codestream to transmission errors. This information is typically generated when the image is encoded using a JPEG 2000 Part 1 encoder (e.g., Figures 1 and 3), but it can also be directly derived from a Part 1 codestream (e.g., Figures 2 and 4). This information can subsequently be used when protecting the image. More specifically, sensitive parts of the codestream can be more strongly protected than less sensitive parts (unequal error protection).
+
+The residual errors descriptor specifies the locations of residual errors in the codestream. The residual errors are the errors which cannot be corrected by the error protection tool. This information is typically generated during the error correction process. This information can subsequently be used in the JPEG 2000 Part 1 decoder to prevent decoding of corrupted parts of the stream.
+
+The above figures, describing the JPWL system, are examples and different configurations are possible.
+
+JPWL system has provision for future techniques, in addition to those described in this Recommendation | International Standard. The process of adding new techniques is managed by the Registration Authority as described in Annex K.
+
+# 6 JPWL normative parts
+
+An encoding process converts source image data to compressed image data. All encoding processes are specified informatively.
+
+An encoder is an embodiment of the encoding process. In order to conform to this Recommendation | International Standard, an encoder shall convert source image data to compressed image data that conform to the codestream syntax specified in Annex A.
+
+A decoding process converts compressed image data to reconstructed image data. Some parts of a decoding process are normative, and namely those related to extracting information contained in the JPEG 2000 Part 11 specific marker segments, as well as those that refer to the decoding of JPEG 2000 Part 1 features. All other aspects of the decoding process, for instance the procedure that the decoder shall follow in order to cope with the possible presence of errors and the actions it shall take to minimize their effect, are not specified as part of this Recommendation | International Standard; guidelines are however specified in Annex G.
+
+A decoder is an embodiment of the decoding process. In order to conform to this Recommendation | International Standard, a decoder shall convert all, or specific parts of, any compressed image data that conform to the codestream syntax specified in Annex A to a reconstructed image.
+
+There is no normative or required implementation for the encoder or decoder. In some cases, the descriptions use particular implementation techniques for illustrative purposes only.
+
+Annex A describes the syntax that defines the coded representation of compressed image data for exchange between application environments. Any compressed image data shall comply with the syntax and code assignments appropriate for the coding processes defined in this Recommendation | International Standard.
+
+The remainder of this clause outlines the normative parts of this Recommendation | International Standard and refers to the respective annexes for detailed description:
+
+- Codestream syntax (Annex A): Definition of the codestream syntax every JPWL codestream must conform to.
+- Error protection block (Annex B): Tool to protect the image header (main header, tile/tile-part header) and to correct the possible presence of transmission errors using FEC codes.
+- Error protection capability descriptor (Annex C): Description of the tools which have been used to protect the codestream and to correct the possible presence of transmission errors. This descriptor relies on a registration authority as to the informative error protection techniques.
+- Error sensitivity descriptor (Annex D): Description of the degree of sensitivity of different parts of the codestream to transmission errors. This information is typically generated when encoding the image. It can subsequently be used to apply Unequal Error Protection (UEP) techniques which take into account the error sensitivity.
+- Residual errors descriptor (Annex E): Description of the locations of residual errors in the codestream. The residual errors are the errors which cannot be corrected by the tools used to protect the image. This information is typically generated when decoding the codestream.
+- Registration authority (Annex K): Specification of the Registration Authority (RA).
+
+# 7 JPWL informative parts
+
+This clause outlines informative parts of this Recommendation | International Standard and refers to the respective annexes for detailed description:
+
+- Encoding guidelines (Annex F): Guidelines for error-resilient coding at the encoder side in the context of error prone environments.
+- Decoding guidelines (Annex G): Guidelines for error handling behaviour at the decoder side.
+- Error-resilient entropy coding (Annex H): Tools to protect the codestream and to detect and correct the possible errors based on error-resilient entropy coding.
+- Unequal error protection (Annex I): Tools to protect differently parts of the codestream based upon the error sensitivity of the respective parts.
+- Interoperability with ISO/IEC 15444 (Annex J): Guidelines for interoperability with other specifications in the JPEG 2000 family.
+- Patents (Annex L): Received intellectual property rights statements that apply to this Recommendation | International Standard.
+
+# Annex A
+
+## Codestream syntax
+
+(This annex forms an integral part of this Recommendation | International Standard)
+
+## A.1 Definitions of markers and marker segments
+
+This Recommendation | International Standard relies on the use of marker segments to delimit and signal the characteristics of the codestream in order to protect it against errors. For backward compatibility, the JPWL markers and marker segments must be included in JPEG 2000 Part 1 codestream headers, which can be of two types only:
+
+- 1) the main header, found at the beginning of the codestream;
+- 2) the tile-part headers, found at the beginning of each tile-part.
+
+Main and tile-part headers are collections of markers and marker segments.
+
+As for every other standard marker defined in JPEG 2000 Part 1, each marker defined in this proposal is two bytes long, and its first byte value is 0xFF. The second byte specifies the marker use and can take any value in the range 0x01 to 0xFE, apart from those already used by ITU-T Rec. T.81 | ISO/IEC 10918-1 and ITU-T Rec. T.84 | ISO/IEC 10918-3 (recalled in Table A.1).
+
+A marker segment includes a marker and associated parameters, called marker parameters. By definition, the first two bytes of any marker segment immediately after the marker must correspond to an unsigned big endian integer value that denotes the length in bytes of the marker parameters (including two bytes of this length parameter but not including the two bytes of the marker itself). When the decoder finds a marker segment that is not specified in this Recommendation | International Standard, it shall use the length parameter to discard the marker segment.
+
+### A.2 Marker code range defined in this Recommendation | International Standard
+
+Following the syntax used for each marker and marker segment defined in ITU-T Rec. T.81 | ISO/IEC 10918-1, this Recommendation | International Standard reserves some markers for signalling, as specified in Table A.1. Table A.1 recalls the various values of already existing or reserved markers.
+
+Table A.1 – Marker definitions
+
+| Marker value range                                | Standard definition                                          |
+|---------------------------------------------------|--------------------------------------------------------------|
+| 0xFF00, 0xFF01, 0xFFFE, 0xFFC0 – 0xFFDF           | Defined in ITU-T Rec. T.81   ISO/IEC 10918-1                 |
+| 0xFFF0 – 0xFFF6                                   | Defined in ITU-T Rec. T.84   ISO/IEC 10918-3                 |
+| 0xFFF7 – 0xFFF8                                   | Defined in ITU-T Rec. T.87   ISO/IEC 14495-1                 |
+| 0xFF4F – 0xFF65, 0xFF6A – 0xFF6F, 0xFF90 – 0xFF93 | ITU-T Rec. T.800   ISO/IEC 15444-1                           |
+| 0xFF66 – 0xFF69                                   | Defined in this Recommendation   International Standard      |
+| 0xFF30 – 0xFF3F                                   | Reserved for definition as markers only (no marker segments) |
+|                                                   | All other values reserved.                                   |
+
+### A.3 Marker and marker segment and codestream rules
+
+Marker segments, described in this Recommendation | International Standard, are respecting the rules given in A.1.3/JPEG 2000 Part 1.
+
+### A.4 Information in the marker segments
+
+As standardized in JPEG 2000 Part 1, marker segments, and therefore the main and tile-parts headers, are a multiple of 8 bits (one byte).
+
+All markers and marker segments in a tile-part header or a start of packet header apply only to the tile or the packet to which it belongs.
+
+If truncation, alteration, or editing of the codestream has been done, the impacted marker segments (like TLM/PLT or JPWL marker segments) shall be updated accordingly. Note that several JPWL marker segments contain codestream indexing information (e.g., byte ranges); this information must be updated upon insertion or cancellation of a marker segment.
+
+Table A.2 lists the markers specified in this Recommendation | International Standard and Table A.3 lists the information provided by the syntax and indicates the marker segment containing that information.
+
+**Table A.2 – List of marker segments**
+
+|                                                                                                  | Name | Code   | Main header<br>(Note) | Tile-part header<br>(Note) |
+|--------------------------------------------------------------------------------------------------|------|--------|-----------------------|----------------------------|
+| Error Protection Block                                                                           | EPB  | 0xFF66 | Optional              | Optional                   |
+| Error Sensitivity Descriptor                                                                     | ESD  | 0xFF67 | Optional              | Optional                   |
+| Error Protection Capability                                                                      | EPC  | 0xFF68 | Required              | Optional                   |
+| Residual Errors Descriptor                                                                       | RED  | 0xFF69 | Optional              | Optional                   |
+| NOTE – Required means the marker segment shall be in this header, optional means it may be used. |      |        |                       |                            |
+
+If the EPC, ESD or RED marker segments appear both in the main header and tile-part header, the marker present in the tile-part header is overriding the one present in the main header for the current tile-part. The EPC and RED marker segments are allowed to appear at most once per header (main or tile-part header). Multiple ESD in one single header are allowed.
+
+## A.5 Construction of the codestream
+
+The construction of the codestream of this Recommendation | International Standard complies with the codestream construction defined in A.3/JPEG 2000 Part 1. The EPB marker segment(s) are required to be in a specific location, as specified in Annex B.
+
+**Table A.3 – Information in the marker segments**
+
+| Information                                                                                                                                                                                                                                               | Marker segment |
+|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------|
+| Signals the presence of JPWL protected data in the header. It includes: <ul style="list-style-type: none"> <li>– Set of error protection parameters used in the codestream.</li> <li>– Error protection data generated from a systematic code.</li> </ul> | EPB            |
+| Indicates the methods used in the current codestream to protect it against transmission errors. Its presence signals the fact that the codestream complies with this Recommendation   International Standard.                                             | EPC            |
+| Describes the sensitivity to errors of the current codestream                                                                                                                                                                                             | ESD            |
+| Describes the index of the residual errors of the current codestream                                                                                                                                                                                      | RED            |
+
+## A.6 JPWL marker segments
+
+#### A.6.1 Error Protection Block (EPB)
+
+The EPB marker segment contains information about the error protection parameters and data used to protect the codestream against errors. The primary function of EPB is to protect the main and tile-part header (see Annex B). However, it can also be used to protect the bitstream (see Annex I). There can be one or more EPB marker segments in the main header and/or tile-part headers. The first EPB marker segment in a main header is required to be placed immediately after the SIZ marker segment. The first EPB marker segment in a tile-part header is required to be placed immediately after the SOT marker.
+
+**Function:** The EPB marker segment contains necessary error correction data for the header where it is located. See Annex B and Annex I for more information on how to use EPB marker segments.
+
+**Usage:** Main header and tile-part headers. The first EPB marker segment of the codestream must be placed after the SIZ marker segment. The first EPB marker segment of a tile-part header must be placed after the SOT marker segment.
+
+**Length:** Variable depending on the parameters used to protect the headers and the length of the headers to be protected. Figure A.1 describes the syntax of the EPB marker segment.
+
+![Diagram of Error Protection Block (EPB) syntax. It shows a sequence of fields: EPB, Lepb, Depb, LDPe pb, and Pe pb, followed by a shaded area representing EPB data. The reference T.810(06)_FA.1 is noted to the right.](5cab96b2d23174c25919840ecd50aa48_img.jpg)
+
+T.810(06)\_FA.1
+
+Diagram of Error Protection Block (EPB) syntax. It shows a sequence of fields: EPB, Lepb, Depb, LDPe pb, and Pe pb, followed by a shaded area representing EPB data. The reference T.810(06)\_FA.1 is noted to the right.
+
+**EPB:** Marker code. Table A.4 indicates the size and parameter values of the marker symbol itself and of each parameter of the marker segment.
+
+**Lepb:** Length of marker segment in bytes (not including the marker).
+
+**Depb:** EPB style (for example it defines if the current EPB is the latest in the current header).
+
+**LDPe pb:** Length of the data to be protected by the redundant information (EPB data) carried within the current EPB.
+
+**Pe pb:** EPB parameters defining the next error correction tool to be used for protecting the remaining data.
+
+**EPB data:** Contains the data enabling the correction (typically redundancy bits).
+
+Figure A.1 – Error Protection Block syntax
+
+Table A.4 – Error Protection Block parameter values
+
+| Parameter | Size (bits) | Values                                                                |
+|-----------|-------------|-----------------------------------------------------------------------|
+| EPB       | 16          | 0xFF66                                                                |
+| Lepb      | 16          | 11-(2 <sup>16</sup> -1)                                               |
+| Depb      | 8           | See Table A.5                                                         |
+| LDPe pb   | 32          | 0-(2 <sup>31</sup> -1)                                                |
+| Pe pb     | 32          | See Table A.6<br>Defines the next error management method to be used. |
+| EPB data  | variable    |                                                                       |
+
+When the EPB is included in a main header, the SOC marker, the SIZ marker segment, the EPB marker, the Lepb, Depb, LDPe pb, Pe pb data are protected with a predefined RS(N1,K1) code. The redundant data needed for error correction are placed at the beginning of the EPB data.
+
+When the EPB is included in a tile-part header, the SOT marker, the EPB marker, the Lepb, Depb, LDPe pb and Pe pb data are protected with a predefined RS(N2,K2) code. The redundant data needed for error correction are placed at the beginning of the EPB data.
+
+There can be several EPB marker segments in the main or tile-part headers. When an EPB is not the first one in the header, a predefined RS(N3,K3) code is used.
+
+The predefined codes are:
+
+- Reed Solomon RS(160,64) to be used for the first EPB marker segment of the main header;
+- Reed Solomon RS(80,25) to be used for the first EPB marker segment of a tile-part header;
+- Reed Solomon RS(40,13) to be used for the other EPB marker segments of both the main header and the tile-part header.
+
+##### A.6.1.1 EPB style parameter
+
+Table A.5 – Depb parameter values
+
+| Values (bits)<br>MSB                  LSB | EPB configuration and index                                                                                                                                                                                                                            |
+|-------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| x0xx xxxx                                 | The EPB marker segment is not the latest in the current header                                                                                                                                                                                         |
+| x1xx xxxx                                 | The EPB marker segment is the latest in the current header                                                                                                                                                                                             |
+| 0xxx xxxx                                 | EPBs marker segments are unpacked                                                                                                                                                                                                                      |
+| 1xxx xxxx                                 | EPBs marker segments are packed                                                                                                                                                                                                                        |
+| xx00 0000 – xx11 1111                     | EPB index values (0-63).<br>The first EPB marker segment in an header has the index value zero. For every successive EPB in the same header this index value is incremented by one. When the maximum number is reached, the number rolls over to zero. |
+
+##### A.6.1.2 EPB parameters
+
+The Pepb parameters allow the selection of an error correction/detection method, by describing both the method and the related parameters. This allows the error correction/detection capacity to be changed along the codestream and to adapt it to the error conditions and/or the sensitivity to errors of the codestream part it is referring to. Any method can be used as long as it respects the backward compatibility with or without extension criterion defined previously in this Recommendation | International Standard (see clause 5).
+
+Table A.6 defines the range of values for Pepb parameter. Other codes definitions than thus of Table A.6 can use an Error Management method index in the range of values, with a use and registration managed by the Registration Authority (see Annex K).
+
+The error management method specified in a current Pepb has to be used for the codestream data concerned by the current EPB marker segment, except the EPB marker and the EPB marker parameters, already concerned by one of the predefined codes.
+
+**Table A.6 – Pepb parameter**
+
+| Error Management method index | EPB configuration and index                                                                                                                                                                                                                                                                                                      |
+|-------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| 0x00000000                    | Predefined codes:<br>Reed Solomon RS(160,64) to be used for the first EPB marker segment of the main header<br>Reed Solomon RS(80,25) to be used for the first EPB marker segment of a tile-part header<br>Reed Solomon RS(40,13) to be used for the other EPB marker segments of both the main header and the tile-part header. |
+| 0x10000000-0x1FFFFFFF         | CRC, see Table A.7                                                                                                                                                                                                                                                                                                               |
+| 0x20000000-0x2FFFFFFF         | Reed Solomon codes, see Table A.8                                                                                                                                                                                                                                                                                                |
+| 0x30000000-0xFFFFFFF          | Use and registration managed by the JPWL Registration Authority                                                                                                                                                                                                                                                                  |
+| 0xFFFFFFFF                    | No method to be used for the next data                                                                                                                                                                                                                                                                                           |
+
+**Table A.7 – CRC types**
+
+| Pepb value                                | CRC type                                                        |
+|-------------------------------------------|-----------------------------------------------------------------|
+| 0001 0000 0000 0000                       | CRC-CCITT (X.25) 16 bits CRC                                    |
+| 0001 0000 0000 0001                       | Ethernet CRC 32 bits                                            |
+| 0001 0000 0000 0010 – 0001 1111 1111 1111 | Use and registration managed by the JPWL Registration Authority |
+
+**Table A.8 – Reed-Solomon default codes**
+
+| Pepb value            | Reed Solomon code                                               |
+|-----------------------|-----------------------------------------------------------------|
+| 0x20002520            | RS(37,32)                                                       |
+| 0x20002620            | RS(38,32)                                                       |
+| 0x20002820            | RS(40,32)                                                       |
+| 0x20002B20            | RS(43,32)                                                       |
+| 0x20002D20            | RS(45,32)                                                       |
+| 0x20003020            | RS(48,32)                                                       |
+| 0x20003320            | RS(51,32)                                                       |
+| 0x20003520            | RS(53,32)                                                       |
+| 0x20003820            | RS(56,32)                                                       |
+| 0x20004020            | RS(64,32)                                                       |
+| 0x20004B20            | RS(75,32)                                                       |
+| 0x20005020            | RS(80,32)                                                       |
+| 0x20005520            | RS(85,32)                                                       |
+| 0x20006020            | RS(96,32)                                                       |
+| 0x20007020            | RS(112,32)                                                      |
+| 0x20008020            | RS(128,32)                                                      |
+| Other RS index values | Use and registration managed by the JPWL Registration Authority |
+
+#### A.6.2 Error Protection Capability (EPC)
+
+The EPC marker segment indicates which JPWL normative and informative tools are used in the codestream. Namely, it indicates the presence of the ESD marker segment, the RED marker segment, and the EPB marker segment in the codestream. Furthermore, EPC signals the use of informative tools which have been previously registered with the JPWL Registration Authority (JPWL RA, see Annex K). These informative tools allows for error-resilience and/or error-correction, and include techniques such as error-resilient entropy coding, UEP, data partitioning and interleaving. EPC may also contain parameters relative to these informative tools.
+
+**Function:** The EPC marker segment signals the use of JPWL tools (ESD, RED, EPB) or informative tools in the codestream. See Annex C for more information on how to use EPC marker segment.
+
+**Usage:** Mandatory in main header, optional in tile-part headers. No more that one EPC shall appear in each main or tile-part header.
+
+**Length:** Variable.
+
+The syntax of the EPC marker segment is defined in Figure A.2. The meaning of the data fields is discussed below, and the range of possible values for each parameter is defined in Table A.9. A more detailed description of EPC is given in Annex C.
+
+![Figure A.2: Error Protection Capability syntax diagram. The diagram shows the structure of the EPC marker segment. At the top, a horizontal bar represents the EPC segment, divided into five fields: 'EPC', 'Lepc', 'P_CRC', 'DL', and 'Pepc'. The 'Pepc' field is labeled 'Pepc' above it. Below this bar, the 'DL' field is further detailed as a sequence of three parts: 'ID^(1)', 'L_ID^(1)', and a shaded area representing 'P_ID^(1)'. This structure is repeated for multiple techniques, indicated by an ellipsis '...' and a second instance of 'ID^(n)', 'L_ID^(n)', and 'P_ID^(n)'.](77464a47f104d0d647b2414591137b64_img.jpg)
+
+T.810(06)\_FA.2
+
+Figure A.2: Error Protection Capability syntax diagram. The diagram shows the structure of the EPC marker segment. At the top, a horizontal bar represents the EPC segment, divided into five fields: 'EPC', 'Lepc', 'P\_CRC', 'DL', and 'Pepc'. The 'Pepc' field is labeled 'Pepc' above it. Below this bar, the 'DL' field is further detailed as a sequence of three parts: 'ID^(1)', 'L\_ID^(1)', and a shaded area representing 'P\_ID^(1)'. This structure is repeated for multiple techniques, indicated by an ellipsis '...' and a second instance of 'ID^(n)', 'L\_ID^(n)', and 'P\_ID^(n)'.
+
+**EPC:** Marker code. Table A.9 indicates the size and parameter values of the marker symbol itself and of each parameter of the marker segment.
+
+**L<sub>EPC</sub>:** Length of marker segment in bytes (not including the marker).
+
+**P<sub>CRC</sub>:** Parity check bits which verify whether the EPC marker segment is corrupted.
+
+**DL:** Field describing the total data length the EPC marker segment is referring to (codestream length or tile-part length, starting from the SOC or SOT marker segment).
+
+**P<sub>epc</sub>:** Field signalling the usage of ESD, RED, EPB or informative techniques in the codestream.
+
+**ID<sup>(i)</sup>:** Registered ID for protection technique *i*, optional, present only when informative technique is used.
+
+**L<sub>ID<sup>(i)</sup></sub>:** Length of P<sub>ID<sup>(i)</sup></sub>, optional, present only when informative technique is used.
+
+**P<sub>ID<sup>(i)</sup></sub>:** Parameters for protection technique *i*, optional, present only when informative technique is used.
+
+Figure A.2 – Error Protection Capability syntax
+
+**Table A.9 – Error Protection Capacity parameter values**
+
+| Parameter             | Size (in bits) | Values                                                                                                                                                                                                                                                                                                                       |
+|-----------------------|----------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| EPC                   | 16             | 0xFF68                                                                                                                                                                                                                                                                                                                       |
+| $L_{\text{EPC}}$      | 16             | $[9, 2^{16}-1]$                                                                                                                                                                                                                                                                                                              |
+| $P_{\text{crc}}$      | 16             | Cyclic Redundancy Check of EPC marker segment, excluding the Pcrc data field. Uses the CRC-CCITT (see Annex B).                                                                                                                                                                                                              |
+| DL                    | 32             | $[0, 2^{32}-1]$<br>Data length expressed in bytes as an unsigned integer number<br>0 means that this information is not available.                                                                                                                                                                                           |
+| $P_{\text{epc}}$      | 8              | See Table A.10                                                                                                                                                                                                                                                                                                               |
+| $ID^{(i)}$            | 16             | $[0, 2^{16}-1]$<br>0 indicates the EPB technique<br>Refer to Annex B for the use of EPB<br>1-15 are reserved<br>other values are registered with the RA                                                                                                                                                                      |
+| $L_{\text{ID}}^{(i)}$ | 16             | $[0, 2^{16}-1]$                                                                                                                                                                                                                                                                                                              |
+| $P_{\text{ID}}^{(i)}$ | Variable       | If $ID^{(i)}=0$ , indicating the EPB technique, $P_{\text{ID}}^{(i)}$ is the concatenation of all Pepb present in the EPB marker segments, except those corresponding to the predefined and default codes as described in Table A.8 as well as CRC codes defined in Table A.7<br>Otherwise specified by means of the JPWL RA |
+
+When EPB is used for protecting the codestream, ID parameters of EPC marker segment shall not be present to describe this technique if the method used is one of those included in Table A.6 (pre-defined codes), Table A.7 (CRC codes) or Table A.8 (Reed Solomon default codes).
+
+If the EPC marker segment is located in the main header, the data length (DL) is the length of the codestream, expressed in bytes as an unsigned integer number, from the first byte of the SOC marker to the last byte of the EOC marker.
+
+If the EPC marker segment is located in a tile-part header, the data length (DL) is the length of this tile-part, expressed in bytes as an unsigned integer number, from the first byte of the SOT marker to the last byte of the tile-part.
+
+**Table A.10 – Pepc parameter**
+
+| Pepc                  | Parameter value                             |
+|-----------------------|---------------------------------------------|
+| xxx0 xxxx             | ESD is not present                          |
+| xxx1 xxxx             | One or more ESD are present                 |
+| xx0x xxxx             | RED is not present                          |
+| xx1x xxxx             | One or more RED are present                 |
+| x0xx xxxx             | EPB is not present                          |
+| x1xx xxxx             | One or more EPB are present                 |
+| 0xxx xxxx             | Informative techniques are not used         |
+| 1xxx xxxx             | One or more informative techniques are used |
+| 0000 0000 – 0000 1111 | Reserved for future use                     |
+
+#### A.6.3 Error Sensitivity Descriptor (ESD)
+
+The ESD marker segment can be placed in any valid position in a codestream main and/or tile-part header. It is allowed that more than one ESD marker segments are present in a main or tile-part header.
+
+**Function:** The ESD marker segment contains the sensitivity information for a given codestream or tile. See Annex D for more information on how to use ESD marker segments.
+
+**Usage:** Main header and/or tile-part headers.
+
+**Length:** Variable, depending on the usage and on the granularity of the error sensitivity description.
+
+The syntax of the ESD marker segment is depicted in Figure A.3. The meaning of the data fields is discussed below; the range of possible values taken on by each parameter is discussed in Annex D. A detailed description of the ESD nomenclature and functionalities is provided in Annex D.
+
+![Figure A.3 – Syntax of the ESD marker segment. The diagram shows a sequence of five rectangular blocks: ESD, Lesd, Cesd, Pesd, and ESD data. The Cesd and ESD data blocks are filled with diagonal hatching. The label 'Pesd' is centered above the Pesd block. The labels 'Cesd' and 'ESD data' are placed below their respective blocks. A small reference code 'T.810(06)_FA.3' is located at the bottom right of the diagram.](83852ec55d4802521a727926336bedab_img.jpg)
+
+Figure A.3 – Syntax of the ESD marker segment. The diagram shows a sequence of five rectangular blocks: ESD, Lesd, Cesd, Pesd, and ESD data. The Cesd and ESD data blocks are filled with diagonal hatching. The label 'Pesd' is centered above the Pesd block. The labels 'Cesd' and 'ESD data' are placed below their respective blocks. A small reference code 'T.810(06)\_FA.3' is located at the bottom right of the diagram.
+
+**ESD:** Marker code. Table A.11 indicates the size and parameter values of the marker symbol itself and of each parameter of the marker segment.
+
+**Lesd:** Length of marker segment in bytes (not including the marker).
+
+**Cesd:** Specifies which component the ESD data refer to.
+
+**Pesd:** Field describing the usage of the data structure.
+
+**ESD data:** Records of error sensitivity values.
+
+**Figure A.3 – Syntax of the ESD marker segment**
+
+**Table A.11 – Parameters of the ESD marker segment**
+
+| Parameter | Size (bits)   | Values                                                                                                          |
+|-----------|---------------|-----------------------------------------------------------------------------------------------------------------|
+| ESD       | 16            | 0xFF67                                                                                                          |
+| Lesd      | 16            | 4–(2 <sup>16</sup> –1)                                                                                          |
+| Cesd      | 8<br>or<br>16 | 0-255 if Csiz < 257<br>0-16383 if Csiz ≥ 257<br>Specifies which component the error sensitivity data refer to.  |
+| Pesd      | 8             | 0-255<br>(See Annex D).                                                                                         |
+| ESD data  | Variable      | This field contains sensitivity information related to the codestream data, in the format specified in Annex D. |
+
+**Table A.12 – Value of Pesd parameter. Format: 0xb<sub>7</sub>b<sub>6</sub>b<sub>5</sub>b<sub>4</sub>b<sub>3</sub>b<sub>2</sub>b<sub>1</sub>b<sub>0</sub>**
+
+|                                                                                                                                |                                                                                                                                                                                                                                                                                         |
+|--------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| b <sub>7</sub> b <sub>6</sub>                                                                                                  | These bits specify the codestream addressing mode:<br>00: packet mode (Note)<br>01: byte-range mode<br>10: packet-range mode (Note)<br>11: reserved for future use                                                                                                                      |
+| b <sub>5</sub> b <sub>4</sub> b <sub>3</sub>                                                                                   | These bits specify the type of error sensitivity description employed.<br>000: relative error sensitivity.<br>001: MSE<br>010: MSE reduction<br>011: PSNR<br>100: PSNR increase<br>101: MAXERR (absolute peak error)<br>110: TSE (total squared error)<br>111: reserved for future use. |
+| b <sub>2</sub>                                                                                                                 | If it is set to 0, one byte is used to represent each sensitivity value; if it is set to 1, two bytes are used to represent each sensitivity value.                                                                                                                                     |
+| b <sub>1</sub>                                                                                                                 | 0: two bytes are used to indicate the start and end bytes in the <i>byte-range mode</i> , and the start and end packets in the <i>packet-range mode</i> .<br>1: four bytes are used.<br>When <i>packet mode</i> is used, this bit shall be set to 0.                                    |
+| b <sub>0</sub>                                                                                                                 | If it is set to 1, error sensitivity values are average values among all the components. In this case, Cesd must be equal to 0.                                                                                                                                                         |
+| NOTE – When packet or packet range addressing mode is used, use of JPEG 2000 Part 1 PLM or PLT marker segments is recommended. |                                                                                                                                                                                                                                                                                         |
+
+#### A.6.4 Residual Error Descriptor (RED)
+
+The RED marker segment can be placed in any valid position in the main or tile-part header. RED marker segment signals the presence of residual errors and may help to handle them.
+
+After any form of channel decoding some residual error may still affect the codestream. As described in previous clauses, these errors may be very harmful if located in one of the JPEG 2000 Part 1 headers. In order to allow the JPEG 2000 decoder to be aware of the presence and the location of these errors, as well as their category (e.g., bit flipping or erasures), JPWL uses RED to embed this information in the codestream. The RED marker segment can be operated in three different modes, namely byte-range mode, packet mode and packet-range mode
+
+- In *byte-range mode*, each data unit is described by explicitly specifying its start and end byte in the codestream; the residual error value refers to that specific byte range. Start and end bytes are specified as two or four unsigned integers; this allows to deal with "normal" and "long" codestreams. Byte numbering in the codestream starts from zero. If the RED is located in the main header, byte numbering refers to the start of the codestream (including the SOC marker segment). If the RED is located in a tile-part header, byte numbering refers to the start of that tile-part (including the SOT marker segment).
+- In *packet mode*, the data units are packets as defined in JPEG 2000 Part 1. A residual error value is specified for each and every packet in the codestream or tile-part, according to whether the RED is contained in the main header or in a tile-part header.
+- In *packet-range mode*, a range of JPEG 2000 packets, defined by a start and an end packet identifies a data unit for which a residual error value is provided. Start and end packets are specified as two or four bytes unsigned integers.
+
+When RED is in the main header, and packet mode or packet range is used, the numbering of the packets corresponds to the order of the packets in the codestream. When RED is in tile-part header and packet mode or packet range is used, the numbering of the packets corresponds to the numbering used in A.8.1/JPEG 2000 part 1, starting at zero at every new tile.
+
+Figure A.4 describes the syntax of the RED data structure. It consists of the following fields:
+
+- RED: Marker code. Table A.13 indicates the size and parameter values of the marker symbol itself and of each parameter of the marker segment.
+- $L_{red}$ : Length of marker segment in bytes (not including the marker).
+- $P_{red}$ : Field describing the usage of the data structure.
+- RED data: Record of parameters related to residual error descriptor.
+
+![Diagram showing the syntax of the residual error descriptor marker segment. It consists of four fields: 'RED' (marker code), 'Lred' (length of marker segment), 'Pred' (usage field), and 'RED data' (record of parameters). The 'RED data' field is shaded with diagonal lines. The diagram is labeled 'T.810(06)_FA.4'.](75e4b78ee25f885d73120e3066a5253e_img.jpg)
+
+The diagram illustrates the syntax of the residual error descriptor (RED) marker segment. It is represented as a horizontal sequence of four fields:
+ 
+
+- RED**: The marker code, shown in a white box.
+- Lred**: The length of the marker segment in bytes (excluding the marker itself), shown in a white box.
+- Pred**: A field describing the usage of the data structure, shown in a white box.
+- RED data**: A record of parameters related to the residual error descriptor, shown in a box with diagonal hatching.
+
+ The label 'T.810(06)\_FA.4' is positioned to the right of the 'RED data' field.
+
+Diagram showing the syntax of the residual error descriptor marker segment. It consists of four fields: 'RED' (marker code), 'Lred' (length of marker segment), 'Pred' (usage field), and 'RED data' (record of parameters). The 'RED data' field is shaded with diagonal lines. The diagram is labeled 'T.810(06)\_FA.4'.
+
+**Figure A.4 – Syntax of the residual error descriptor marker segment**
+
+Table A.13 – Residual error descriptor parameter values
+
+| Parameter                                                                                                                      | Size (bits) | Values                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
+|--------------------------------------------------------------------------------------------------------------------------------|-------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| RED                                                                                                                            | 16          | 0xFF69                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
+| L <sub>red</sub>                                                                                                               | 16          | $3 \cdot (2^{16} - 1)$                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
+| P <sub>red</sub>                                                                                                               | 8           | $0 \cdot 2^8 - 1$<br>P <sub>red</sub> Format: 0xb7b6b5b4b3b2b1b0<br>b7b6 Addressing Mode<br>b7b6 = 00 Packet Addressing Mode (Note)<br>b7b6 = 01 Byte-Range Addressing Mode<br>b7b6 = 10 Packet-Range Addressing Mode (Note)<br>b7b6 = 11 reserved for future use<br>b5b4b3 Residual corruption level<br>000 - 111<br>b2 Reserved for future use<br>b1 Address length<br>b1 = 0 - 2-Bytes Addressing Mode<br>b1 = 1 - 4-Bytes Addressing Mode<br>b0 Error Free Codestream Indicator<br>b0 = 0 Error Free codestream<br>b0 = 1 Error/Erasure presents in the codestream |
+|                                                                                                                                | Variable    | This field contains residual error information related to the codestream data, in the format specified in Annex E.                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
+| NOTE – When packet or packet range addressing mode is used, use of JPEG 2000 Part 1 PLM or PLT marker segments is recommended. |             |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
+
+# Annex B
+
+## Header error protection
+
+(This annex forms an integral part of this Recommendation | International Standard)
+
+### B.1 Introduction
+
+During the establishment of JPEG 2000 standard, a set of error-resilience tools have been selected for JPEG 2000 Part 1, for the transmission of JPEG 2000 compressed images in an error-prone environment. Two types of tools are available, at the packet level, which enable synchronization, and at the entropy coding level, enabling error detection. For more information about the use of JPEG 2000 Part 1 error-resilience tools, refer to Annexes G and H.
+
+These tools are, however, based on one major hypothesis, namely that the headers (main header and tile-part(s) header(s)) of the codestream syntax are guaranteed to be error-free. However, in the case of error within the headers, the codestream is not decodable in an appropriate way, which might lead to a decoder application crash. The worst is that, generally, it might not be possible to guarantee that the headers will be kept free of errors in many applications. The header protection mechanism detailed hereafter in this annex describes a scheme that embeds the protection within the JPEG 2000 codestream. This mechanism is backward compatible with JPEG 2000 Part 1 codestream syntax.
+
+#### B.1.1 JPEG 2000 Part 1 codestream syntax backward compatibility
+
+A JPEG 2000 Part 1 compressed image uses markers and marker segments to delimit and signal the compressed information, organized in headers (main and tile-parts) and packets. This modular organization allows flexible codestream organization for progressive data representation, such as quality-progressive and resolution-progressive data progression. A JPEG 2000 Part 1 codestream always starts with the main header followed by one or several tile-part headers, each of them followed by compressed data packets, and ends with an End Of Codestream (EOC), as shown in Figure B.1.
+
+![Diagram of JPEG 2000 codestream structure showing a sequence of Main header, Tile part header, Packet, and EOC marker.](19a59d6b53059ebd27b13c98793f88e0_img.jpg)
+
+The diagram illustrates the structure of a JPEG 2000 codestream. It consists of a sequence of components represented by rectangular boxes. The sequence starts with a 'Main header' box, followed by a 'Tile part header' box, then two 'Packet' boxes. This is followed by an ellipsis '...', then another 'Packet' box, a 'Tile part header' box, and two more 'Packet' boxes. Another ellipsis '...' follows, then a 'Packet' box, a 'Tile part header' box, and two 'Packet' boxes. Finally, there is an ellipsis '...' followed by an 'EOC marker' box. The label 'T.810(06)\_FB.1' is positioned at the bottom right of the diagram.
+
+Diagram of JPEG 2000 codestream structure showing a sequence of Main header, Tile part header, Packet, and EOC marker.
+
+**Figure B.1 – JPEG 2000 codestream structure**
+
+With the objective of obtaining a codestream compliant with ITU-T Rec. T.800 | ISO/IEC 15444-1 after the insertion of the redundant information, it is necessary to place this information in such a way that any JPEG 2000 Part 1 decoder will not try to interpret it. A solution for this is to insert the redundant information in a dedicated marker segment. A JPEG 2000 Part 1 decoder will then skip the unknown marker segment and be oblivious to the added data, whereas a JPWL decoder will be able to interpret and use the redundancy for header protection.
+
+The conditions for such a mechanism to work are:
+
+- that the decoder is able to locate the redundant information data block in the codestream without generating complex data indexing mechanisms (that would also have to be protected against errors) nor by modifying the first marker segments imposed for the backward compatibility;
+- that the marker itself and its length are included in the data range to be protected;
+- that a defined block error code is used to protect parameters data at least up to the Error Protection Block marker segment.
+
+The Error Protection Block marker segment (EPB) is placed immediately after the JPEG 2000 Part 1 markers mandatory locations:
+
+- after the SOC and SIZ marker segments for the main header;
+- after the SOT marker for the tile-part header.
+
+The use of a systematic forward error-correction mechanism ensures that the first two conditions are verified.
+
+#### B.1.2 Forward error-correction mechanism
+
+Error correction and detection codes are traditionally used to provide forward error-correction capabilities in error-prone environments [8]. Systematic codes are those that produce a given amount of redundant information, while leaving the original data untouched.
+
+Considering that JPEG 2000 Part 1 codestreams are byte aligned, it is especially interesting to work with the Galois Field  $GF(2^8)$  to provide error-correction capability. A well-known and well-suited family of systematic codes in this context is Reed-Solomon (RS) codes. In the following, we will consider the example of RS codes as FEC codes for header protection, and denote them by  $RS(N,K)$ , where  $N$  is the codewords symbol length and  $K$  the number of information symbols.
+
+The  $RS(N,K)$  applied to  $K$  bytes will generate  $N-K$  redundancy bytes, that may be placed after the  $K$  original (systematic) bytes, this process being applied as long as necessary, as illustrated in Figure B.2.
+
+![Diagram illustrating redundancy generation with an RS(N,K) code. On the left, four vertical bars represent K information symbols. An arrow points to the right, where the resulting codewords are shown. Each codeword consists of the original K information symbols followed by N-K redundancy symbols. The diagram shows four such codewords, with the label 'T.810(06)_FB.2' below the redundancy part of the first codeword.](7e1c9b51e067a48cd0fcc9748d8bd8d8_img.jpg)
+
+Diagram illustrating redundancy generation with an RS(N,K) code. On the left, four vertical bars represent K information symbols. An arrow points to the right, where the resulting codewords are shown. Each codeword consists of the original K information symbols followed by N-K redundancy symbols. The diagram shows four such codewords, with the label 'T.810(06)\_FB.2' below the redundancy part of the first codeword.
+
+**Figure B.2 – Example of redundancy generation with an  $RS(N,K)$  code**
+
+### B.2 Predefined error-correction codes
+
+Since during the transmission on an error-prone environment, errors may occur anywhere in the JPEG 2000 codestream, the header protection tool cannot rely on parameter information for indicating the error-correction code to use. Therefore, a set of predefined codes has been defined whereas the EPB marker segment syntax allows the choice of others for some part of the headers. The possible systematic error-correction codes are listed in Table A.6.
+
+In order to efficiently fight harsh transmission conditions, these predefined codes offer a large correction capacity, while limiting byte padding. Three predefined error-correction codes have been defined for protecting the main header and the tile-part headers:
+
+- $RS(160,64)$  to be used for the first EPB marker segment of the main header;
+- $RS(80,25)$  to be used for the first EPB marker segment of a tile-part header;
+- $RS(40,13)$  to be used for the other EPB marker segments of both the main header and the tile-part header.
+
+These Reed-Solomon codes are always used for the protection of the beginning of main and tile-part headers, as well as the parameters of any EPB marker segment. Other codes may be used for protecting the other parts of the headers by using an appropriate Pepb value.
+
+The use of error-protection can be stopped within the current header by using the appropriate LDPe pb data length and by indicating the end of the error protected data range through Pepb value.
+
+### B.3 Use of EPB for header protection
+
+#### B.3.1 Main header error protection
+
+When encountering an EPB marker segment, the JPWL decoder may apply the correction of the codestream it refers to. For the main header, when doing this correction, first, the JPWL decoder applies this correction to the SOC and SIZ marker segments, as well as to the EPB marker segment parameters. This range of data corresponds to L1 in Figure B.3. The redundant information necessary for this correction is located at the beginning of the EPB redundant data, illustrated by L2 in Figure B.3.
+
+Once the EPB parameters have been corrected, it is then possible to take these parameters into account, especially the Depb, LDPe pb and the Pepb parameters. These parameters are necessary for using the error correction for the remaining parts of the main header. They allow the error correction code redundancy to be adapted to the error conditions. This structure enables to protect differently fundamental JPEG 2000 Part 1 marker segments, such as QCD, to be protected whereas optional marker segments like PLM can be protected with less redundancy, or even not protected at all.
+
+![Diagram of EPB marker position in main header and protection regions. The diagram shows a sequence of fields: SOC, SIZ, a dashed box, EPB, Lepb, Depb, LDPe pb, and Pepb. These are grouped into four regions: L1 (SOC, SIZ, dashed box), L2 (EPB, Lepb, Depb, LDPe pb), L3 (Pepb), and L4 (Remaining marker segments). Brackets below indicate these regions. A reference T.810(06)_FB.3 is shown on the right.](a74294f34a0c736b7ee0f5f0cdca7e28_img.jpg)
+
+Diagram of EPB marker position in main header and protection regions. The diagram shows a sequence of fields: SOC, SIZ, a dashed box, EPB, Lepb, Depb, LDPe pb, and Pepb. These are grouped into four regions: L1 (SOC, SIZ, dashed box), L2 (EPB, Lepb, Depb, LDPe pb), L3 (Pepb), and L4 (Remaining marker segments). Brackets below indicate these regions. A reference T.810(06)\_FB.3 is shown on the right.
+
+**Figure B.3 – EPB marker position in main header and protection regions**
+
+Figure B.3 illustrates the case where a single EPB marker segment is used to protect the main header. In this case, L1 data are protected by the L2 part of the EPB data, using the default main header error correction code. L4 data are protected using L3, with the error-correction code specified in the Pepb parameter.
+
+The LDPe pb parameter allows the error protection to be stopped at any byte-aligned location within the main header. LDPe pb gives the number of bytes which are protected using the default error-correction code and the code specified in the Pepb parameter. As an example, in Figure B.3, LDPe pb is equal to L1 + L4 bytes. LDPe pb shall not point to data fields which are outside of the main header.
+
+The main header can contain several EPB marker segments, that may be unpacked or packed, which means that they appear one after another, before the remaining main header information. Unpacked EPBs means that they will appear just before the data part they refer to. An example of packed and unpacked EPBs is given later in this annex. For each new EPB, the predefined code RS(40,13) has to be used for the correction of its own EPB parameters.
+
+#### B.3.2 Tile-part header error protection
+
+When EPB is present in tile-part header(s), the JPWL decoder may apply correction to the SOT marker segment, as well as to the EPB marker segment parameters. This range of data corresponds to L1 in Figure B.4. The redundant information necessary for this correction is located in the beginning of the EPB redundant data, illustrated by L2 in Figure B.4.
+
+Once the EPB parameters have been corrected, it is then possible to take these parameters into account, especially the Depb, LDPe pb and the Pepb parameters. These parameters are necessary for using the error correction for the remaining parts of the tile-part header. They allow the error correcting code redundancy to adapt to the error conditions. This structure enables differently fundamental JPEG 2000 Part 1 marker segments, such as QCD, to be protected whereas optional marker segments like PLT can be protected with less redundancy, or even not protected at all.
+
+![Diagram of EPB marker position in tile-part header and protection regions (single EPB case). The diagram shows a sequence of fields: SOT, EPB, Lepb, Depb, LDPe pb, and Pepb. These are grouped into four regions: L1 (SOT, EPB, Lepb, Depb, LDPe pb), L2 (Pepb), L3 (Remaining tile-part header marker segments), and L4 (SOD). Brackets below indicate these regions. A reference T.810(06)_FB.4 is shown on the right.](ea4fd10a9a501c602f2bea0f7f711877_img.jpg)
+
+Diagram of EPB marker position in tile-part header and protection regions (single EPB case). The diagram shows a sequence of fields: SOT, EPB, Lepb, Depb, LDPe pb, and Pepb. These are grouped into four regions: L1 (SOT, EPB, Lepb, Depb, LDPe pb), L2 (Pepb), L3 (Remaining tile-part header marker segments), and L4 (SOD). Brackets below indicate these regions. A reference T.810(06)\_FB.4 is shown on the right.
+
+**Figure B.4 – EPB marker position in tile-part header and protection regions (single EPB case)**
+
+Figure B.4 illustrates the case where a single EPB marker segment is used to protect the tile-part header. In this case, L1 data are protected by the L2 part of the EPB data, using the default tile-part header error correction code. L4 data are protected using L3, with the error-correction code specified in the Pepb parameter.
+
+The LDPe pb parameter allows the error protection to be stopped at any byte-aligned location within the tile-part header. LDPe pb gives the number of bytes which are protected using the default error-correction code and the code specified in the Pepb parameter. As an example, in Figure B.4, LDPe pb is equal to L1 + L4 bytes. LDPe pb for EPBs present in tile-part headers may point to data fields which are outside of the tile-part header. This feature is necessary for enabling the use of EPB for unequal error protection purposes as explained in Annex I.
+
+#### B.3.3 Packed and unpacked error-protection blocks
+
+In the case where the main or tile-part header is of a large size, for example, due to the inclusion of several PPM or PPT marker segments, it is possible to use more than one EPB marker segment. The Depb parameter, specified in Table A.5, allows this functionality. This parameter also allows the indication of how the EPB information was placed in the header. There are two possibilities for chaining this information, while keeping the error-protection feature among them:
+
+- One way is to interleave between the various EPB, some marker segments of the header to be protected. This structure is called "unpacked EPB marker segments".
+- The other way, which provides optimal redundant information length, called "packed EPB marker segments", consists in grouping together all the EPB marker segments before the remaining marker segments of the header.
+
+In both cases, the "Last EPB marker" information allows the identification of the EPB marker segments as being the latest in the header. It is particularly interesting when using the packed EPB option, where it allows the allocation of the remaining header data, which is to be found just after the current EPB marker segment.
+
+In both cases, for each new EPB, except the first one in the header, the predefined code RS(40,13) has to be used for the correction of the EPB parameters, whereas the remaining data considered by the LDPepb parameter are protected using the tools described in Pepb.
+
+![Diagram of unpacked EPB markers in a tile-part header. The header is divided into segments: SOT, EPB, Lepb, Depb, LDPepb, Pepb, followed by a large block 'Remaining tile-part header marker segments', then another EPB, Lepb, Depb, LDPepb, Pepb, another 'Remaining tile-part header marker segments' block, and finally SOD. Brackets below indicate protection regions: L1 (under first EPB), L2 (under first Lepb), L3 (under first Pepb), L4 (under first 'Remaining...' block), L'1 (under second EPB), L'2 (under second Lepb), L'3 (under second Pepb), and L'4 (under second 'Remaining...' block). The label T.810(06)_FB.5 is at the bottom right.](392a79ccd95e682ccd08f35ab2e64144_img.jpg)
+
+|     |     |      |      |        |      |    |                                            |     |      |      |        |      |  |                                            |     |
+|-----|-----|------|------|--------|------|----|--------------------------------------------|-----|------|------|--------|------|--|--------------------------------------------|-----|
+| SOT | EPB | Lepb | Depb | LDPepb | Pepb |    | Remaining tile-part header marker segments | EPB | Lepb | Depb | LDPepb | Pepb |  | Remaining tile-part header marker segments | SOD |
+| L1  |     | L2   |      | L3     |      | L4 |                                            | L'1 |      | L'2  |        | L'3  |  | L'4                                        |     |
+
+T.810(06)\_FB.5
+
+Diagram of unpacked EPB markers in a tile-part header. The header is divided into segments: SOT, EPB, Lepb, Depb, LDPepb, Pepb, followed by a large block 'Remaining tile-part header marker segments', then another EPB, Lepb, Depb, LDPepb, Pepb, another 'Remaining tile-part header marker segments' block, and finally SOD. Brackets below indicate protection regions: L1 (under first EPB), L2 (under first Lepb), L3 (under first Pepb), L4 (under first 'Remaining...' block), L'1 (under second EPB), L'2 (under second Lepb), L'3 (under second Pepb), and L'4 (under second 'Remaining...' block). The label T.810(06)\_FB.5 is at the bottom right.
+
+Figure B.5 – Unpacked EPB markers position in tile-part header and protection regions (several EPB cases)
+
+Figure B.5 illustrates the case where two unpacked EPB marker segments are used to protect the tile-part header. In this case, L1 data are protected by the L2 part of the first EPB data, and L'1 data are protected by the L'2 part of the second EPB data using the default tile-part header error-correction code. L4 data are protected using L3, with the error-correction code specified in the Pepb parameter of the first EPB marker segment. L'4 data are protected using L'3, with the error-correction code specified in the Pepb parameter of the second EPB marker segment.
+
+![Diagram of packed EPB markers in a tile-part header. The header is divided into segments: SOT, EPB, Lepb, Depb, LDPepb, Pepb, followed by another EPB, Lepb, Depb, LDPepb, Pepb, then a large block 'Remaining tile-part header marker segments', and finally SOD. Brackets below indicate protection regions: L1 (under first EPB), L2 (under first Lepb), L3 (under first Pepb), L'1 (under second EPB), L'2 (under second Lepb), L'3 (under second Pepb), L4 (under 'Remaining...' block), and L'4 (under 'Remaining...' block). The label T.810(06)_FB.6 is at the bottom right.](bb3354f497635d15bef873577125c48d_img.jpg)
+
+|     |     |      |      |        |      |     |     |      |      |        |      |    |                                            |     |  |
+|-----|-----|------|------|--------|------|-----|-----|------|------|--------|------|----|--------------------------------------------|-----|--|
+| SOT | EPB | Lepb | Depb | LDPepb | Pepb |     | EPB | Lepb | Depb | LDPepb | Pepb |    | Remaining tile-part header marker segments | SOD |  |
+| L1  |     | L2   |      | L3     |      | L'1 |     | L'2  |      | L'3    |      | L4 |                                            | L'4 |  |
+
+T.810(06)\_FB.6
+
+Diagram of packed EPB markers in a tile-part header. The header is divided into segments: SOT, EPB, Lepb, Depb, LDPepb, Pepb, followed by another EPB, Lepb, Depb, LDPepb, Pepb, then a large block 'Remaining tile-part header marker segments', and finally SOD. Brackets below indicate protection regions: L1 (under first EPB), L2 (under first Lepb), L3 (under first Pepb), L'1 (under second EPB), L'2 (under second Lepb), L'3 (under second Pepb), L4 (under 'Remaining...' block), and L'4 (under 'Remaining...' block). The label T.810(06)\_FB.6 is at the bottom right.
+
+Figure B.6 – Packed EPB markers position in tile-part header and protection regions (several EPB cases)
+
+Figure B.6 illustrates the case where two packed EPB marker segments are used to protect the tile-part header. In this case, L1 data are protected by the L2 part of the first EPB data, and L'1 data are protected by the L'2 part of the second EPB data using the default tile-part header error-correction code. L4 data are protected using L3, with the error-correction code specified in the Pepb parameter of the first EPB marker segment. L'4 data are protected using L'3, with the error-correction code specified in the Pepb parameter of the second EPB marker segment.
+
+#### B.3.4 Cyclic redundancy check
+
+The Pepb parameter can describe two types of different techniques, cyclic redundancy check and error-correction, while describing the parameters to be used by these techniques. In order to insure that data have been transmitted error free, most communications protocols use a parity check process called Cyclic Redundancy Check (CRC) [11]. CRC codes are a subset of linear block codes.
+
+CRC can be used in EPB, instead of error-correction redundancy data, except for the parameters of the EPB marker segments which are always protected using the appropriate default error-protection code. The use of CRC is signalled by the Pepb parameter of the EPB marker segment (see Tables A.6 and A.7).
+
+An M-bits CRC has the mathematical property of detecting all errors that occur in M or fewer consecutive bits, and the probability of 1 over  $2^M$  of not detecting an error. In typical applications, the CRC is 16 bits long.
+
+An M-bits CRC is based on a polynomial of degree M. JPWL is using the two following polynomials:
+
+For 16 bits CRC (CCITT-CRC/X25):  $x^{16}+x^{12}+x^5+1$
+
+For 32 bits CRC (AUTODIN/ETHERNET):  $x^{32}+x^{26}+x^{23}+x^{22}+x^{16}+x^{12}+x^{11}+x^{10}+x^8+x^7+x^5+x^4+x^2+x+1$
+
+# Annex C
+
+## Error protection capability
+
+(This annex forms an integral part of this Recommendation | International Standard)
+
+### C.1 Usage of the EPC marker segment
+
+The EPC marker segment signals whether the three other normative marker segments defined by JPWL, namely the error sensitivity descriptor (ESD), the residual error descriptor (RED) and the error protection block (EPB) are present in the codestream. In addition, it signals the use of informative tools in order to protect the codestream against transmission errors. These tools include techniques such as error-resilient entropy coding, FEC codes, UEP and data partitioning/interleaving. These informative tools are not defined in this Recommendation | International Standard. Instead, they are registered with the JPWL RA. Upon registration, each tool is assigned an ID, which uniquely identifies it. More information about the use of the RA can be found in Annex K. The EPC marker segment also makes provisions for the handling of parameters related to these informative tools. When encountering a JPWL codestream, the decoder can identify the tool(s) which have been used to protect this codestream by parsing the EPC marker segment and by querying the RA. The decoder can then take the appropriate steps to decode the codestream, e.g., acquire or download the appropriate tool.
+
+The EPC marker segment is mandatory in the main header, and optional in the tile-part header. At most one EPC can be present in each main and tile-part header.
+
+An EPC marker segment can contain more than one ID (with the related parameters), indicating that more than one error protection technique has been applied to the codestream. The order in which the IDs have to appear in the EPC is the order in which the techniques have to be applied at the *decoder* side. An EPC marker segment is allowed to contain no ID.
+
+If a technique applies to the entire codestream, its ID has to be indicated in the EPC in the main header. An EPC in a tile-part header can contain IDs of techniques that are applied to that tile-part.
+
+It is up to the encoder to ensure that combinations of two or more techniques lead to consistent and meaningful results, and that the decoder has enough resources to carry out decoding. To avoid processing overload, in case of multiple techniques it is not mandatory for the decoder to decode all techniques; this also allows a decoder to process only those parts of the codestream protected by known techniques. Moreover, it is worth noticing that combinations of two or more techniques may be registered in the RA as a single new technique.
+
+### C.2 $P_{CRC}$
+
+The  $P_{CRC}$  is a 16 bits parameter that contains parity check bits to verify whether the EPC marker has been corrupted by errors. Specifically, the CRC is computed on a codeword consisting of the concatenation of EPC,  $L_{EPC}$ , CL,  $P_{EPC}$  and the complete sequence of  $ID^{(i)}$ ,  $L_{ID}^{(i)}$  and  $P_{ID}^{(i)}$  (i.e., the complete marker segment excluding  $P_{CRC}$  itself). The CCITT-CRC/X25 defined in B.3.4 has to be used to generate the parity bits.
+
+### C.3 Data length (DL)
+
+A compressed video sequence can be transmitted as a sequence of raw codestreams. In this case, the decoder has to take care of correctly synchronizing at the start of each new frame. While in the error-free case this is not an issue as the SOC and EOC markers can be parsed to locate the start and the end of each codestream, in an error-prone environment this may not be the case since these markers can be corrupted and hence unusable. For this reason, it is useful that some additional "redundant" information is inserted which may be exploited by the decoder to improve its ability to resynchronize after a decoding failure. To this end, the EPC marker segment contains the DL parameter, which specifies when the EPC is located in the main header, the total length  $L$  in bytes of the current codestream. As a consequence, if the EOC marker is not found where it is expected, the decoder can skip  $L$  bytes starting from the SOC, and verify if the SOC marker of the next frame is uncorrupted. Otherwise, if the SOC marker of the current frame is also corrupted, the decoder can seek the EOC marker of the last frame, skip  $L+2$  bytes, and verify the presence of the SOC marker of the next frame.
+
+The DL parameter is an unsigned integer number represented on four bytes, and represents the length in bytes of the current codestream when the EPC marker segment is located in the main header, or zero if this information is not available.
+
+The DL parameter is an unsigned integer number represented on four bytes, and represents the length in bytes of the current tile-part header, when the EPC marker segment is located in this current tile-part header or zero if this information is not available.
+
+### C.4 $P_{\text{EPC}}$
+
+$P_{\text{EPC}}$  is a 8-bits parameter which indicates the presence of ESD, RED and EPB marker segments in the codestream, as well as the use of informative tools. This information is useful in order for a decoder to quickly know whether the codestream can be decoded and which information is available in the codestream.
+
+### C.5 Identification of tools (ID)
+
+Informative tools to protect the codestream against transmission errors have to be registered with the RA (see Annex K). Upon registration, each tool is assigned an ID, which uniquely identifies it.
+
+At the encoder side, when using a registered informative tool, the corresponding ID is inserted in EPC in order to signal its use. At the decoder side, the decoder parses the EPC marker segment and can identify the registered informative tools which have been used. The decoder can then query the RA about these tools, and takes the most appropriate actions to decode the codestream (e.g., acquire or download the appropriate tool).
+
+The values 0 to 15 of ID are reserved.
+
+### C.6 Parameters for tools ( $P_{\text{ID}}$ )
+
+This parameter can be used to signal parameters for the tools which have been applied to the codestream.
+
+The format of  $P_{\text{ID}}$  is not specified in this Recommendation | International Standard but is registered by means of the RA at the time of the tool registration.
+
+# Annex D
+
+## Error sensitivity descriptor
+
+(This annex forms an integral part of this Recommendation | International Standard)
+
+### D.1 Introduction and applications
+
+Error sensitivity information provides a measure of how much different parts of the codestream are sensitive to errors, i.e., the effect of losing each part on the quality of the decoded image. Error sensitivity signalling has several possible applications; a few of them are described as follows:
+
+- Unequal error protection. In UEP, more powerful codes are assigned to the most sensitive parts of the codestream. This typically provides higher average PSNR with respect to the equal protection strategy. The allocation of codes to each part of the codestream depends on the sensitivity of each part. It is worth noticing that, for unequal protection, the error sensitivity information is exploited by the encoder, but is not required by the decoder which just needs to know which protection parameters have been employed (see example of UEP in Annex I).
+- Rate transcoding. In some applications, there may be a subsystem handling the transmission of images and video from a source to one or more users. The subsystem can be aware of the codestream syntax, and can carry out a basic parsing. If rate transcoding must be carried out to adapt the incoming data-rate to the current transmission conditions, the subsystem can adopt intelligent quality of service policies by not only truncating the codestream, but also looking up the error sensitivity table to make sure that the selected truncation rate provides a reasonable degree of image quality.
+- Selective retransmissions. The subsystem capabilities can also be exploited to optimize the retransmission management, by allocating a larger number of retransmission attempts to those codestream portions that are more critical from the quality standpoint based on the error sensitivity information.
+- Smart prefetching. In streaming video applications, the subsystem can decide to prefetch the most important packets of the current and next frames, and to send them in advance. This permits the execution of a larger number of retransmissions if some of these packets should be lost. The most important codestream portions can be selected by simply looking up the ESD content.
+
+It is worth noticing that the error sensitivity information is less critical than other portions of a JPEG 2000 Part 11 compliant codestream, as it is not strictly needed for decoding.
+
+### D.2 Marker definition and position in the codestream
+
+The ESD is a marker segment that contains information related to the error sensitivity of different parts of a codestream or tile.
+
+The ESD marker segment shall appear in the main header and/or in the tile-part headers. If it appears in the main header, its sensitivity description shall apply to the complete codestream, whereas if it appears in a tile-part header the description shall apply only to that tile-part. It is intended that, if an ESD marker segment is present in both the main header and the tile-part header, in case of ambiguity, the information in the tile-part header ESD will override that in the main header ESD. More than one ESD is allowed in each main and tile-part header; this can be used to provide error sensitivity using *different* metrics, e.g., both MSE and MAXERR. It is, however, possible that two ESD marker segments are present in a given header and use the same error metric, and that they cover overlapping portions of the codestream. In order to avoid ambiguity in the error sensitivity description, it is intended that, as far as the overlapping portions with same metric are concerned, the error sensitivity values in the last ESD have to be used.
+
+### D.3 Codestream subdivision into data units
+
+Sensitivity information is provided for one or more specific data units in the codestream. This annex specifies three different addressing modes for defining data units, namely *packet mode*, *byte-range mode* and *packet-range mode*.
+
+- In *byte-range mode*, each data unit is described by explicitly specifying its start and end byte in the codestream; the sensitivity value refers to that specific byte range. Start and end bytes are specified as two- or four-bytes unsigned integers; this allows the processing of "normal" and "long" codestreams. Byte numbering in the codestream starts from zero. If the ESD is located in the main header, byte numbering refers to the start of the codestream (including the SOC marker segment). If the ESD is located in a tile-part header, byte numbering refers to the start of that tile-part (including the SOT marker segment).
+- In *packet mode*, the data units are packets as defined in JPEG 2000 Part 1. A sensitivity value is specified for each and every packet in the codestream or tile-part, according to whether the ESD is contained in the main header or in a tile-part header.
+- In *packet-range mode*, a range of JPEG 2000 packets, defined by a start and an end packet, identifies a data unit for which a sensitivity value is provided. Start and end packets are specified as two- or four-bytes unsigned integers.
+
+When ESD is in the main header, and packet mode or packet range is used, the numbering of the packets corresponds to the order of the packets in the codestream. When ESD is in tile-part header and packet mode or packet range is used, the numbering of the packets corresponds to the numbering used in A.8.1/JPEG 2000 Part 1, starting at zero at every new tile-part.
+
+### D.4 Sensitivity information
+
+#### D.4.1 Meaning of sensitivity values
+
+For multi-component images, error-sensitivity values contained in the ESD marker segment can refer to a single component, or can be intended as average values among all components, as specified by *Pesd*.
+
+Sensitivity values can be expressed in two different ways, i.e., as *relative* or *absolute* sensitivity values. (Note that the definition of *relative sensitivity* in JPWL is equivalent to the *relative importance* in JPSEC.) Relative sensitivity is expressed as an unsigned integer number describing the error sensitivity of a given codestream portion with respect to other portions. Absolute sensitivity refers to sensitivity information related to a specific error metric, such as MSE, PSNR or MAXERR (maximum absolute error). The *Pesd* parameter specifies whether the relative or absolute sensitivity mode is being used.
+
+Relative sensitivity information for each codestream data unit shall be expressed as an unsigned integer number ranging from 0 to  $2^P-1$ . The parameter P can be either 8 or 16; this allows choosing between a rough but compact description, and a more precise one. It is intended that the highest values of sensitivity shall be assigned to the "most important" parts of the codestream. The value  $2^P-1$  shall be exclusively reserved to main and tile-part headers. In particular, data units partially or totally containing the main or tile-part header of a given codestream may have sensitivity equal to  $2^P-1$ ; conversely, data units *not* containing portions of the main or tile-part header shall not have sensitivity equal to  $2^P-1$ . The value 0 shall be used for parts of the codestream for which sensitivity information is not specified. All the other values shall represent the relative importance of the considered portion of the codestream, in the  $[1, 2^P-2]$  range, with larger numbers indicating the highest levels of importance.
+
+Absolute sensitivity values can also be expressed using one or two bytes, as indicated in the *Pesd* parameter. The value 0xFF for the one-byte case (resp. 0xFFFF for the two-byte case) shall be exclusively reserved to main and tile-part headers. In particular, data units partially or totally containing the main or tile-part header of a given codestream may have sensitivity equal to zero; conversely, data units *not* containing portions of the main or tile-part header shall not have sensitivity equal to zero. The value 0 shall be used for parts of the codestream for which sensitivity information is not specified. All the other values shall represent the metric value related to the considered portion of the codestream.
+
+Absolute sensitivity values are tied to a specific error/quality metric, such as MSE, TSE, PSNR or MAXERR. Normal and incremental error metrics can be used, such as "MSE" and "MSE decrease", or "PSNR" and "PSNR increase". "MSE" means the mean-squared-error incurred by decoding up to (and including) the data unit for which MSE is specified; "MSE decrease" specifies the improvement in MSE achieved by decoding that data unit; and analogously for PSNR. TSE refers to the total squared error, as opposed to the mean squared error.
+
+The error/quality metrics refer to the whole image or to a tile, according to whether the ESD is included in a main or tile-part header.
+
+Since this information may be difficult to estimate, no specific degree of accuracy is required. These metrics shall be expressed in linear units; in particular, denoting as  $x_i$  (with  $i=1, \dots, N$ ) the values of  $N$  pixels of the original image, and as  $r_i$  those of the decoded image, the error metrics are defined as follows:
+
+$$\text{MSE} = \frac{1}{N} \sum_{i=1}^N (x_i - r_i)^2$$
+
+$$\text{TSE} = \text{MSE} * N$$
+
+$$\text{PSNR} = \frac{M^2}{\text{MSE}}$$
+
+$$\text{MAXERR} = \max_i |x_i - r_i|$$
+
+where  $M$  is the maximum value that the original image can assume in the given representation (e.g., for 8-bit images  $M=255$ ); assuming that the image is stored using  $Q$  significant bits,  $M$  shall be equal to  $2^Q-1$  if the data are unsigned integers, and to  $2^{Q-1}-1$  if they are signed integers.
+
+In the two-byte format, absolute sensitivity values shall be expressed as a two-byte number in pseudo floating-point format. Each 16-bit number contains the exponent (5 bits) and mantissa (11 bits) of the metric value. Note that a sign bit is unnecessary since metric values are non-negative. In particular, the floating-point value  $V$  of the metric is given by the following formula (which is the same as in E.1.1.1/T.800 for the determination of the quantization step size):
+
+$$V = 2^{\varepsilon-15} \left( 1 + \frac{\mu}{2^{11}} \right) \quad \text{if } \varepsilon \neq 0$$
+
+$$V = 0 \quad \text{if } \varepsilon = 0$$
+
+where  $\varepsilon$  is the unsigned integer obtained from the first five most significant bits of the parameter, and  $\mu$  the unsigned integer obtained from the remaining 11 bits. The special case of  $V = \infty$  corresponds to  $\mu = 0$  and  $\varepsilon = 31$ . Notice that values that would underflow the representation are set to zero.
+
+The algorithm to compute  $s$ ,  $\varepsilon$  and  $\mu$  is not defined as a mandatory part of this Recommendation | International Standard. A possible technique performs the following steps (an example of conversion of the number 12.25 is provided). If  $V = 0$ , set  $\varepsilon = \mu = 0$ . Otherwise:
+
+- convert  $V$  to a binary number ( $12.25_{10} = 1100.01_2$ );
+- normalize the number; this means there should be a 1 digit to the left of the binary point and multiplication by the appropriate power of two to represent the original value. The normalized form of 1100.01 is  $1.10001 \times 2^3$ ;
+- the exponent is the power of 2, presented in excess notation. The exponent bias is 15; hence, for this example, the exponent is represented as  $18_{10}$  ( $10010_2$ );
+- the mantissa represents the significant bits, *except for the bit to the left of the binary point*, which is always one and therefore does not need to be stored; zeros are possibly appended so as to obtain 11 bits. For this example, the mantissa is 10001000000.
+
+The one-byte format is defined as follows, and is exactly the same as the one-byte format for total distortion field in JPSEC. The metric value is expressed using a one-byte distortion field with a pseudo floating-point type representation. The 8 bits available in the distortion field are allocated to the mantissa ( $m$ ) and base-16 exponent ( $\text{exp}$ ) of the metric value to provide an appropriate trade-off between accuracy and dynamic range. Note that, as in the two-byte format, a sign bit is unnecessary since metric values are non-negative. To cover a sufficient dynamic range, base 16 is used and 4 bits are used for the exponent ( $\text{exp}$ ). The mantissa ( $m$ ) is expressed using 4 bits. Therefore, the metric value  $V$  is given by:
+
+$$V = m \times 16^{\text{exp}}$$
+
+where  $m$  has a value in the range  $0 \leq m \leq 15$  and  $\text{exp}$  has a value in the range  $0 \leq \text{exp} \leq 15$ . A value of zero is represented by  $m = 0$  and  $\text{exp} = 0$ , that is by the metric field being zero. By allocating 4 bits for the mantissa  $m$  the accuracy is within  $\frac{1}{2} \times (1/2^4) = 1/32$  or about 3%. With 4 bits for the exponent and using base-16 the dynamic range is from 0 to max, where max is given by  $m = 15$  and  $\text{exp} = 15$  which corresponds to a metric value of  $15 \times 16^{15} = 1.7 \times 10^{19}$ .
+
+Note that with this format for the metric value, a comparison between two metrics to determine which is larger can be simply achieved by comparing the two values as unsigned char. Specifically, to perform this comparison, there is no need to convert from the pseudo floating-point format to the actual value in order to determine which of two values is larger or smaller. This property can simplify the processing in various applications.
+
+#### D.4.2 ESD data field
+
+Three cases are considered in the definition of the ESD data field, according to the codestream addressing method in use.
+
+In *packet mode*, a sensitivity value is provided for each and every packet in the codestream or tile-part, according to whether the ESD is contained in the main header or in a tile-part header; the ESD data field contains the concatenation of (relative or absolute) sensitivity values for each packet. If the ESD marker segment is in the main header, it is assumed that these values appear in the order specified by the packet numbering of the SOP marker (see JPEG 2000 Part 1, Annex A.8.1); if it is in a tile-part header, the ESD data field contains a concatenation of sensitivity values for all packets contained in that tile-part. Notice that the Lesd parameter can be used to compute in advance the number of sensitivity values contained in the ESD data field.
+
+In *byte-range mode*, the ESD data field is again a concatenation of records. The length of each data record depends on whether two or four bytes are employed for the specification of each start and end byte, and on whether one or two bytes are used for the sensitivity description. These parameters can be inferred from Pesd. Each record contains, in the following order, the start byte of the data unit, the end byte of the data unit, and the (absolute or relative) sensitivity value for the data unit. Start and end bytes refer to the beginning of the codestream or of a tile-part, according to whether the ESD marker segment is included in a main or tile-part header. Notice that the Lesd parameter can be used to compute in advance the number of records contained in the ESD marker segment.
+
+In *packet-range mode*, the ESD data field is again a concatenation of records. Each record has exactly the same structure as in the *byte-range mode*, except for the fact that start and end packets are employed, instead of start and end bytes, to define each data unit. Start and end packets are computed from the beginning of the codestream or of a tile-part, according to whether the ESD marker segment is included in a main or tile-part header.
+
+### D.5 Examples and guidelines
+
+In the following subclauses we provide two examples of possible usage of the ESD marker segment. The first example refers to relative sensitivity, whereas the second one to absolute sensitivity.
+
+#### D.5.1 Example 1 – Relative sensitivity with packet mode
+
+Consider the transmission of a grayscale image at 0.5 bits per pixel (bpp) in non-reversible mode. A JPEG 2000 Part 1 compliant encoder is employed to generate a codestream suitable for transmission over a wireless channel; JPWL is employed to add error-sensitivity information to that codestream and, specifically, an ESD marker segment, so as to optimize the decoder performance. A JPEG 2000 Part 1 encoder can use arithmetic encoder termination, along with SOP and EPH markers, as error-resilience tools. A PPM marker segment is used to pack all the packet headers in the main header, so that all header information is grouped at the beginning of the codestream, and can be protected more easily. A PLM marker segment in the main header would also be useful, so as to summarize the lengths of all packets in the codestream; however, for simplicity, it is not used in this example. The layer-progressive mode is employed for scalability, with layers at 0.25 and 0.5 bpp (i.e., the target bit-rate). The resulting codestream consists of 12 packets. During rate allocation, the encoder collects rate-distortion information. Note that quality metrics in the ESD marker segment are expressed in linear units and not in dB (the value in dB being 10 times the base-10 logarithm of the linear value, which is defined in this annex). Let us assume, for example, that decoding at 0.25 bpp would yield PSNR = 2355 (33.72 dB), whereas decoding at 0.5 bpp would yield PSNR = 5152 (37.12 dB). In terms of JPEG 2000 Part 1 packets, the data provided by the rate allocator are reported in Table D.1. In this table, the column "PSNR" reports the PSNR achieved by decoding the image up to a certain packet; the column " $\Delta$ -PSNR" contains an estimate of the relative contribution of each packet, computed as ratio between the PSNR obtained by decoding up to the current and up to the previous packet (this ratio is equivalent to a difference between the values expressed in dB). A relative error sensitivity can be simply defined by labelling with  $S=0xFE$  the packet with higher PSNR contribution, and then with decreasing values of  $S$  packets with decreasing  $\Delta$ -PSNR, up to the first layer at 0.25 bpp. For all packets in the second layer the sensitivity is the same and is equal to  $S=0xF8$ .
+
+Table D.1 – Error sensitivity computation
+
+| Packet number | Rate (bpp) | PSNR (linear) | PSNR (dB) | $\Delta$ -PSNR | $S$  |
+|---------------|------------|---------------|-----------|----------------|------|
+| 1             | 0.024      | 28.1          | 14.48     | 28.1           | 0xFE |
+| 2             | 0.04       | 154.2         | 21.88     | 5.50           | 0xFD |
+| 3             | 0.077      | 304.8         | 24.84     | 1.98           | 0xFA |
+| 4             | 0.142      | 851.1         | 29.30     | 2.79           | 0xFC |
+| 5             | 0.227      | 2037.0        | 33.09     | 2.39           | 0xFB |
+| 6             | 0.253      | 2355.0        | 33.72     | 1.16           | 0xF9 |
+| 7             | 0.254      | 2471.7        | 33.93     | 1.05           | 0xF8 |
+| 8             | 0.257      | 2483.1        | 33.95     | 1.00           | 0xF8 |
+| 9             | 0.269      | 2546.8        | 34.06     | 1.03           | 0xF8 |
+| 10            | 0.312      | 2844.5        | 34.54     | 1.12           | 0xF8 |
+| 11            | 0.397      | 3572.7        | 35.53     | 1.26           | 0xF8 |
+| 12            | 0.5        | 5152.3        | 37.12     | 1.44           | 0xF8 |
+
+To conclude, we write an ESD marker segment using relative error-sensitivity (one byte per value) as computed above for this example codestream, and packet-mode as indexing mode for the codestream; the metric is specified for the single image component. The resulting hexadecimal representation of the ESD marker segment is the following (parameters are separated by "|", and records by blanks):
+
+FF68 | 0010 | 01 | 00 | FE FD FA FC FB F9 F8 F8 F8 F8 F8
+
+#### D.5.2 Example 2 – Absolute sensitivity with byte-range mode
+
+In this second example we use the byte-range mode (two bytes per start and end byte) and absolute sensitivity in the two-byte format. In particular, "PSNR increase" is selected as error metric. From the previous example we recall that, at rates 0.25 and 0.5 bpp, the PSNR equals 2355 and 5152 respectively (notice that the 0.25 and 0.5 rates refer to the codestream *not including* the ESD marker segment). Moreover, codestream parsing reveals that the first 554 bytes contain the main and tile-part headers. It is then decided to describe three data units, namely the headers, the first, and the second half of the codestream. In particular, the data units are from byte 1 to byte 554 with  $S=0$ , from byte 555 to byte 8224 with  $S=2355$ , and from byte 8225 to byte 16288 with  $S=2797$  ( $=5152-2355$ ). The sensitivity values are specified as average values among all components; since there is only one component, this is equivalent to saying that these values refer to component 1. The resulting marker segment, using the pseudo floating-point notation for  $S$ , is as follows:
+
+FF68 | 0016 | 00 | 65 | 0001 022A 0000 022B 2020 D133 2021 3FA0 D2ED
+
+# Annex E
+
+## Residual errors descriptor
+
+(This annex forms an integral part of this Recommendation | International Standard)
+
+## E.1 Introduction
+
+The RED marker segment signals the presence of residual errors that may still affect the codestream after a JPWL decoder processing. This information on the presence and type (erasure or flipping) of errors may be exploited by a "JPWL aware" JPEG 2000 decoder to improve the decoding capabilities or to apply some techniques as:
+
+- Selective retransmissions;
+- Error concealment;
+- Discard of the corrupted information if not visually relevant.
+
+## E.2 Signalling of residual errors
+
+The RED marker segment can be operated in three different modes, namely byte-range mode, packet mode and packet-range mode.
+
+Byte-range mode:
+
+- In *byte-range mode*, each data unit is described by explicitly specifying its start and end byte in the codestream; the residual error value refers to that specific byte range. Start and end bytes are specified as two or four unsigned integers; this allows to deal with "normal" and "long" codestreams. Byte numbering in the codestream starts from zero. If the RED is located in the main header, byte numbering refers to the start of the codestream (including the SOC marker segment). If the RED is located in a tile-part header, byte numbering refers to the start of that tile-part (including the SOT marker segment). When adopting a Reed Solomon decoder the typical length of each data block is the one of the selected Reed Solomon codeword.
+- The following two bytes contain the number (if available) of errors in the data block (0x0000 – 0xFFFE) or a generic indication of presence of errors (0xFFFF) in case the exact number of errors is not available.
+
+Packet mode:
+
+- In *packet mode*, the data units are packets as defined in JPEG 2000 Part 1. A residual error value is specified for each and every packet in the codestream or tile-part, according to whether the RED is contained in the main header or in a tile-part header. The following two bytes contain:
+  - the number (if available) of errors in the data block (0x0000 – 0xFFFD);
+  - the indication of a packet erasure (0xFFFE);
+  - a generic indication of presence of errors (0xFFFF) in case the exact number of errors is not available.
+
+Packet-range mode:
+
+- In *packet-range mode*, a range of JPEG 2000 packets, defined by a start and an end packet, identifies a data unit for which a residual error value is provided. Start and end packets are specified as two or four bytes unsigned integers.
+- The following two bytes contain the number (if available) of errors in the data block (0x0000 – 0xFFFE) or a generic indication of presence of errors (0xFFFF) in case the exact number of errors is not available.
+
+## E.3 Examples
+
+In the following subclauses we provide two examples of possible usage of the RED marker segment. The first example refers to a packet-mode with sparse errors; the second one refers to erasures in packet mode configuration.
+
+#### E.3.1 Example 1 – Residual Error Descriptor with packet mode and sparse errors
+
+Let us consider the transmission of a grayscale image at 0.5 bits per pixel (bpp) in non-reversible mode. A JPEG 2000 Part 1 compliant encoder is employed to generate a codestream suitable for transmission over a wireless channel; JPWL is employed to add error sensitivity information to that codestream, and specifically an ESD marker segment, so as to optimize the decoder performance. A JPEG 2000 Part 1 encoder can use arithmetic encoder termination, along with SOP and EPH markers, as error-resilience tools. A PPM marker segment is used to pack all the packet headers in the main header, so that all header information is grouped at the beginning of the codestream, and can be protected more easily.
+
+Let us consider that EPB is used to protect both headers and data, adopting Reed Solomon codes, eventually adopting a UEP scheme taking into account ESD information. When working in packet mode, it may be convenient to set EPB length equal to packet length. This simplifies resynchronization in case of entire packet loss.
+
+At receiver side after JPWL decoder it may happen that one or more of the less protected packets still contain errors as they exceed error-protection capabilities of the selected Reed Solomon code inside an EPB.
+
+If not created by the encoder, the JPWL decoder will optionally create the RED marker to signal the residual errors. Assuming, as an example, that packets 7 and 8 still contain errors, the resulting representation of the RED marker segment is the following (parameters are separated by "|", and records by blanks):
+
+```
+FF69h | 001Ch | 00010X01b | 00h 00h 00h 00h 00h 00h FFh FFh 00h 00h 00h 00h
+```
+
+```
+RED | Lred | Pred | RED data
+```
+
+#### E.3.2 Example 2 – Residual Error Descriptor with packet mode and packet loss
+
+Let us consider the same scenario of example 1, i.e., the same image and the same protection scheme. In this case, a packet loss model is adopted for error generation as for example in UDP connections. Let us assume that, in this case, an UDP packet containing JPEG 2000 packets 7 and 8 is completely lost.
+
+If the RED marker segment does not already exist, the JPWL decoder will optionally create the RED marker to signal this situation; the resulting representation of the RED marker segment is the following (parameters are separated by "|", and records by blanks):
+
+```
+FF69h | 001Ch | 00010X01b | 00h 00h 00h 00h 00h 00h FEh FEh 00h 00h 00h 00h
+```
+
+```
+RED | Lred | Pred | RED data
+```
+
+It should be noted that when erasures occur, the decoder has to update the length parameters appearing in marker segments, or fill the gaps with padding dummy data.
+
+# Annex F
+
+## Guidelines for encoding JPEG 2000 codestreams in the context of error-prone environments
+
+(This annex forms an integral part of this Recommendation | International Standard)
+
+## F.1 Introduction
+
+This annex is informative only and provides some guidelines as to the use of JPEG 2000 Part 1 and JPWL tools in error-prone environments. JPEG 2000 Part 1 defines a set of error-resilience tools that can be used to encode an image in an error-prone environment. These tools are categorized as in Table F.1. JPWL defines a set of additional error-protection tools that are able to enhance the codestream resilience towards transmission errors and to help the decoder manage residual errors.
+
+## F.2 JPEG 2000 Part 1 error-resilience tools
+
+**Table F.1 – JPEG 2000 Part 1 error-resilience tools**
+
+| Type of tool         | Name                                                                                                                |
+|----------------------|---------------------------------------------------------------------------------------------------------------------|
+| Entropy coding level | code-blocks<br>termination of the arithmetic coder for each pass<br>predictable termination<br>segmentation symbols |
+| Packet level         | short packet format (packed packet headers)<br>packet with resynchronization marker (SOP)<br>precincts              |
+
+Since channel errors (or packet losses) can exhibit different patterns, in general it is not possible to know in advance which combination of error-resilience tools will yield the best results. However, an extensive study has been carried out in the context of error-prone channels, considering a few realistic application scenarios such as 3GPP networks, Digital Radio Mondiale (DRM), and IEEE 802.11 wireless LANs. From these studies, a few general guidelines can be inferred.
+
+As to the error-resilience tools defined in JPEG 2000 Part 1, the following remarks are in order.
+
+In general, one may want to assign a high level of protection to the main and tile-part header as these headers are necessary in order to correctly perform decoding. In the error-prone case, the packet headers are also very useful as they allow the decoder to skip corrupted coding passes and to resynchronize and continue decoding. It is very easy to protect the packet headers along with the main and/or tile-part headers if the packed packet headers option is used.
+
+Termination of the arithmetic coder allows the detection of transmission errors. If the contexts are reset after each coding pass, the decoder can detect an error, discard the coding passes affected by errors, and continue decoding. This strongly limits the scope of transmission errors and does not excessively increase coding efficiency. Since the coding pass is the basic data unit that can be discarded, in an error-prone environment coding passes should be "as small as possible" without limiting coding efficiency. This implies that using smaller code-blocks with respect to the error-free case will generally yield improved performance.
+
+## F.3 JPEG 2000 encoder implementation guidelines
+
+In this clause we present some guidelines for an implementation of a JPWL compliant encoder. The description of the process is graphically shown in Figure F.1. In particular, the basic actions to follow are:
+
+- JPWL parameters acquisition;
+- JPEG 2000 part 1 coding;
+- Introduction of the desired JPWL markers. In particular:
+  - EPC Marker
+    - Write marker (0xFF68), store the position and jump 8 bytes;
+    - Read JPWL parameters and write Pepc;
+    - If EPB is used, write Pepbs;
+    - Jump back after the marker;
+
+- Compute the marker segment length and the codestream length;
+- Compute and write CRC 16-CCITT;
+- EPB Section
+  - Write marker (0xFF66);
+  - Determine EPB type and protection parameters for the first part of EPB data;
+  - Write LDPepb, Depb, Pepb;
+  - Compute marker segment length;
+  - Store the first part of data to protect and compute  $RS(n1,k1)$ ;
+  - If CRC is requested, compute it on data stored in a buffer;
+  - If a  $RS(n2,k2)$  is requested, compute it on data stored in a buffer;
+- ESD Section
+  - Write marker (0xFF67) and the Cesd and Pesd parameters;
+  - Compute  $\Delta$ -MSE, PSNR, and  $\Delta$ -PSNR from the distortion value of every packet;
+  - Determine the metric to use;
+  - Determine data representation mode (packet, byte-range, or packet-range mode);
+  - Compute error sensitivity values in the chosen metric and data representation mode;
+  - Compute marker segment length.
+- Update pointing structures (Psot field, ESD data in byte-range mode, etc.).
+
+![Flowchart of JPWL encoding procedure guidelines. The process starts with 'START', followed by a decision 'EPB?'. If 'Yes', it goes to 'Parsing till SOT'. If 'No', it goes to 'Copy till SIZ'. From 'Copy till SIZ', it goes to a decision 'RED?'. If 'Yes', it goes to 'Write RED on buffer'. If 'No', it goes to a decision 'ESD?'. If 'Yes', it goes to 'Write ESD on buffer', then 'Correct info_image', then a decision 'Byte range?'. If 'Yes', it goes to 'Correct ESD'. If 'No', it goes to 'Write EPC'. From 'Write EPC', it goes to 'Copy buffer and rest of codestream', then 'EXIT'. From 'Parsing till SOT', it goes to a decision 'i < num_tile?'. If 'Yes', it goes to 'Store TPHi in buf1', then 'Store bitstream i in buf2', then 'Store rest of codestream in buf3', then a decision 'UEP or EEP?'. If 'UEP', it goes to 'Write EPB with UEP algo'. If 'EEP', it goes to 'Write EPB with EEP algo'. From both 'Write EPB' steps, it goes to 'Correct info_image', then 'Copy buffers', then 'Insert EPC, ESD, RED into Main Header', then 'Apply EPB to protect Main Header', then 'EXIT'. From 'i < num_tile?', if 'No', it goes to 'EXIT'.](02bb4edc0dbdf4f0749ffd3e0ea2805c_img.jpg)
+
+```
+
+graph TD
+    START([START]) --> EPB{EPB?}
+    EPB -- Yes --> Parsing[Parsing till SOT]
+    EPB -- No --> SIZ[Copy till SIZ]
+    SIZ --> RED{RED?}
+    RED -- Yes --> WriteRED[Write RED on buffer]
+    RED -- No --> ESD{ESD?}
+    WriteRED --> ESD
+    ESD -- Yes --> WriteESD[Write ESD on buffer]
+    ESD -- No --> CorrectInfo[Correct info_image]
+    WriteESD --> CorrectInfo
+    CorrectInfo --> ByteRange{Byte range?}
+    ByteRange -- Yes --> CorrectESD[Correct ESD]
+    ByteRange -- No --> WriteEPC[Write EPC]
+    CorrectESD --> WriteEPC
+    WriteEPC --> CopyBuffer[Copy buffer and rest of codestream]
+    CopyBuffer --> EXIT1([EXIT])
+    
+    Parsing --> iTile{i < num_tile?}
+    iTile -- Yes --> StoreTPHi[Store TPHi in buf1]
+    iTile -- No --> EXIT1
+    StoreTPHi --> StoreBitstream[Store bitstream i in buf2]
+    StoreBitstream --> StoreRest[Store rest of codestream in buf3]
+    StoreRest --> UEPorEEP{UEP or EEP?}
+    UEPorEEP -- UEP --> WriteEPBUEP[Write EPB with UEP algo]
+    UEPorEEP -- EEP --> WriteEPBEEP[Write EPB with EEP algo]
+    WriteEPBUEP --> CorrectInfoImage[Correct info_image]
+    WriteEPBEEP --> CorrectInfoImage
+    CorrectInfoImage --> CopyBuffers[Copy buffers]
+    CopyBuffers --> InsertMainHeader[Insert EPC, ESD, RED into Main Header]
+    InsertMainHeader --> ApplyEPB[Apply EPB to protect Main Header]
+    ApplyEPB --> EXIT1
+  
+```
+
+T.810(06)\_FF.1
+
+Flowchart of JPWL encoding procedure guidelines. The process starts with 'START', followed by a decision 'EPB?'. If 'Yes', it goes to 'Parsing till SOT'. If 'No', it goes to 'Copy till SIZ'. From 'Copy till SIZ', it goes to a decision 'RED?'. If 'Yes', it goes to 'Write RED on buffer'. If 'No', it goes to a decision 'ESD?'. If 'Yes', it goes to 'Write ESD on buffer', then 'Correct info\_image', then a decision 'Byte range?'. If 'Yes', it goes to 'Correct ESD'. If 'No', it goes to 'Write EPC'. From 'Write EPC', it goes to 'Copy buffer and rest of codestream', then 'EXIT'. From 'Parsing till SOT', it goes to a decision 'i < num\_tile?'. If 'Yes', it goes to 'Store TPHi in buf1', then 'Store bitstream i in buf2', then 'Store rest of codestream in buf3', then a decision 'UEP or EEP?'. If 'UEP', it goes to 'Write EPB with UEP algo'. If 'EEP', it goes to 'Write EPB with EEP algo'. From both 'Write EPB' steps, it goes to 'Correct info\_image', then 'Copy buffers', then 'Insert EPC, ESD, RED into Main Header', then 'Apply EPB to protect Main Header', then 'EXIT'. From 'i < num\_tile?', if 'No', it goes to 'EXIT'.
+
+Figure F.1 – JPWL encoding procedure guidelines
+
+# Annex G
+
+## Recommended decoder error handling behaviour
+
+(This annex forms an integral part of this Recommendation | International Standard)
+
+## G.1 Introduction
+
+If JPEG 2000 Part 1 error-resilience tools are present in a codestream, the decoder has to use them properly. This annex is informative and is intended to define a recommended behaviour for JPEG 2000 Part 1 decoders as well as JPWL decoders, in the presence of errors.
+
+## G.2 JPEG 2000 Part 1 decoder recommended behaviour
+
+#### G.2.1 ISO/IEC 15444-1 Codestream truncation
+
+In cases where the end of the codestream is unavailable due to transmission errors or losses, the decoder is required to decode as much information as it can, as specified in A.4.4/JPEG 2000 Part 1.
+
+Similarly, if a packet is lost within the middle of the codestream, the information in the following packets may not be usable. Nonetheless, the decoder should decode the codestream at least up to the lost packet. Actually, all the code-blocks which have already been included in a previous packet may be de-synchronized. Therefore, no further information should be added to these code-blocks. Data from code-blocks that have not already been included in a previous packet may be recovered properly if the corresponding tag trees are correctly detected.
+
+#### G.2.2 ISO/IEC 15444-1 Codestream segmentation
+
+Codestream is segmented into main header, tile-part header, packet headers and entropy coded data.
+
+There is no specific tool in JPEG 2000 Part 1 either to detect or correct errors in the main header. A standard JPEG 2000 Part 1 decoder will eventually crash in presence of errors in the main header. No specific behaviour can be defined. A reader interested in main header protection should refer to JPEG 2000 Part 11.
+
+There is no specific tool in JPEG 2000 Part 1 to protect the tile-part headers. However, if it can be stated that a given tile-part header is erroneous (for example, SOD not detected properly due to an inconsistency in the header), the decoder may jump to the next tile-part header by scanning the codestream for SOT marker.
+
+There is no specific tool in JPEG 2000 Part 1 to protect the content of packet headers. However, there are tools dedicated to the prevention of codestream de-synchronization. If SOP and EPH, and/or PLM/PLT markers are present, the decoder may check the consistency with the decoding process. During the decoding of a packet header, if the EPH marker is not detected at the expected location or if the length of the packet found while decoding the packet header is not consistent with the length indicated by PLM/PLT markers, then the packet may be considered as erroneous and dropped. The SOP marker and/or PLM/PLT markers are then used to re-synchronize on the next packet. In any case, the decoder should decode as much information as possible.
+
+#### G.2.3 Use of ISO/IEC 15444-1 entropy coding options
+
+Once the codestream has been properly segmented, a certain number of options allows for better entropy coded data error resilience.
+
+More particularly, the predictable termination associated with the termination on each coding pass and the segmentation symbols can be used to detect and to locate errors.
+
+In case of the detection of an error by the predictable termination mechanism, the decoder should:
+
+- If the termination on each coding pass and the segmentation symbols are not used, drop the whole block.
+- If the termination on each coding pass is used, decode up to the last correctly decoded termination, i.e., up to the pass before the one for which the error was detected.
+- If the segmentation symbols are used, decode up to the last correctly decoded segmentation symbol, i.e., skip the last bit-plane of the block.
+- If both termination on each coding pass and segmentation symbols are used, decode up to the last correctly decoded termination.
+
+In case of the detection of an error by the segmentation symbols mechanism, the decoder should:
+
+- If the predictable termination and the termination on each coding pass are not used, or if only predictable termination or termination on each coding pass is used, decode up to the last correctly decoded segmentation symbol, i.e., up to the bit-plane before the one for which the error was detected.
+- If both predictable termination and termination on each coding pass are used, decode up to the last correctly decoded termination, i.e., up to the pass before the one for which the error was detected.
+
+At the encoder side, it is obviously recommended to combine the predictable termination and termination on each coding pass option. As specified in JPEG 2000 Part 1, the segmentation symbols and predictable termination/termination on each coding pass options can be used separately or combined together.
+
+Other error-resilience options (Context reset and bypass) are intended to limit entropy decoder desynchronization in case of errors. No specific behaviour is defined in this annex.
+
+## G.3 JPWL decoder implementation guidelines
+
+In this clause some guidelines for an implementation of a JPWL-compliant decoder are presented. The description of the process is graphically shown in Figure G.1. In particular, the basic actions to follow are:
+
+- Synchronization with the marker segment EPC;
+- Read EPC:
+  - Read Lepc, Pcrc, CL;
+  - Read Pepc and flag usage of JPWL tools;
+  - Store ID structures and create an array with Pepb fields, useful for EPB decoding;
+  - Check CRC and flag presence of errors to the calling function;
+- Read EPB:
+  - EPB parameters correction (RS decoding);
+  - Read Lepb, Depb, LDPEpb, Pepb and check it against the Pepb stored in EPC;
+  - Determine packed/unpacked mode:
+    - Correct following data with RS decoding;
+    - Flag erroneous data with CRC decoding;
+    - Store residual error locations;
+- Write RED:
+  - Go to end of main header and store codestream until EOC;
+  - Write RED parameters and RED data:
+    - Copy structure generated while decoding EPBs;
+    - Correct locations with offset originated by adding RED in the codestream;
+  - Write the rest of the codestream;
+- Read ESD:
+  - Go to SOC and start codestream parsing;
+  - For each ESD marker encountered:
+    - If byte-range mode, then correct sensitivity level locations with Lred;
+    - Read ESD parameters and ESD data;
+  - Optionally, create an "esdmap" file.
+
+![Flowchart of JPWL decoding procedure guidelines. The process starts with 'Input JPWL codestream', followed by 'Read marker'. A decision 'SOC?' leads to 'Return 0' if 'No' or to a loop if 'Yes'. The loop includes 'EOC?' (leading to 'Return Nepe' if 'Yes'), 'Read marker (SIZ or SOT, EPC or EPB)', 'EPC?' (leading to 'Return Nepe' if 'No'), 'Read marker (EPC)', 'EPC?' (leading to 'Return Nepe' if 'No'), 'Read EPB (i=1) and EPC', and 'i < Nepb?' (leading to 'Read EPB' and 'Refresh state' if 'Yes'). A side process 'Residuals?' leads to 'Write RED', 'Read ESD', 'Return Nepe', 'Read EPC', 'Go to next header', and 'Refresh state'.](70a863dc6cd47bac82c12162a9479aac_img.jpg)
+
+```
+
+graph TD
+    Start([Input JPWL codestream]) --> ReadMarker[Read marker]
+    ReadMarker --> SOC{SOC?}
+    SOC -- No --> Return0([Return 0])
+    SOC -- Yes --> EOC{EOC?}
+    EOC -- Yes --> ReturnNepe([Return Nepe])
+    EOC -- No --> ReadMarker2[Read marker  
+(SIZ or SOT, EPC or EPB)]
+    ReadMarker2 --> EPC1{EPC?}
+    EPC1 -- Yes --> ReturnNepe
+    EPC1 -- No --> ReadMarker3[Read marker (EPC)]
+    ReadMarker3 --> EPC2{EPC?}
+    EPC2 -- No --> ReturnNepe
+    EPC2 -- Yes --> ReadEPB[Read EPB (i=1) and EPC]
+    ReadEPB --> iNepb{i < Nepb?}
+    iNepb -- No --> ReturnNepe
+    iNepb -- Yes --> ReadEPB2[Read EPB]
+    ReadEPB2 --> RefreshState1[Refresh state]
+    RefreshState1 --> iNepb
+    
+    SOC -- Yes --> Residuals{Residuals?}
+    Residuals -- No --> ReturnNepe
+    Residuals -- Yes --> WriteRED[Write RED]
+    WriteRED --> ReadESD[Read ESD]
+    ReadESD --> ReturnNepe
+    ReadESD --> ReadEPC[Read EPC]
+    ReadEPC --> GoNextHeader[Go to next header]
+    GoNextHeader --> RefreshState2[Refresh state]
+    RefreshState2 --> iNepb
+  
+```
+
+T.810(06)\_FG.1
+
+Flowchart of JPWL decoding procedure guidelines. The process starts with 'Input JPWL codestream', followed by 'Read marker'. A decision 'SOC?' leads to 'Return 0' if 'No' or to a loop if 'Yes'. The loop includes 'EOC?' (leading to 'Return Nepe' if 'Yes'), 'Read marker (SIZ or SOT, EPC or EPB)', 'EPC?' (leading to 'Return Nepe' if 'No'), 'Read marker (EPC)', 'EPC?' (leading to 'Return Nepe' if 'No'), 'Read EPB (i=1) and EPC', and 'i < Nepb?' (leading to 'Read EPB' and 'Refresh state' if 'Yes'). A side process 'Residuals?' leads to 'Write RED', 'Read ESD', 'Return Nepe', 'Read EPC', 'Go to next header', and 'Refresh state'.
+
+Figure G.1 – JPWL decoding procedure guidelines
+
+# Annex H
+
+## Error-resilient entropy coding
+
+(This annex forms an integral part of this Recommendation | International Standard)
+
+In this annex, a JPEG 2000 Part 11 error-resilient tool at entropy coding level is described. Note that all the techniques here described use the terminology and the assumptions introduced in Annex C/JPEG 2000 Part 1 on Arithmetic Entropy coding. This annex is informative only.
+
+### H.1 Introduction
+
+Entropy coding, and specifically arithmetic codes, are particularly sensitive to bit errors. Indeed, due to the memory inherent to the technique, a single flipped bit may cause de-synchronization of the decoder. Hence, all the remaining symbols can be erroneous. Moreover, in the JPEG 2000 Part 1 Entropy coding case, erroneous symbols can cause unpredictable behaviour in the coding passes e.g., erroneous context generation and coefficient modelling, thus deeply impairing the decoded image quality. Therefore, even raw encoded data using the JPEG 2000 Part 1 bypass entropy coding option is concerned by error propagation.
+
+In JPEG 2000 Part 1, some error-resilience tools have been designed in order to cope with the intrinsic entropy coder error sensitivity. These techniques are based on encoder termination, segmentation and resynchronization markers which allow the JPEG 2000 decoder to implement error-detection strategies; as a consequence, the standard decoder has the ability to skip the erroneous sections of the bitstream so as to avoid the propagation of bit errors at the image level. This approach can be viewed as a concealment technique, that is generally able to cope with transmission channel with moderate bit error rates. In the presence of very harsh transmission conditions, such as in the wireless environment, the employment of powerful error-correction techniques turns out to be essential.
+
+In this annex, a modified arithmetic entropy coder is defined with extended features, namely, the soft resynchronization markers and the forbidden symbol [9][10], that allow the implementation of error-correcting strategies at the code-block level, thus greatly improving the received image quality with respect to the standard concealment approach.
+
+## H.2 Syntax
+
+EPC (Error Protection Capability marker) is used for the specification of the coding parameters as specified in Table A.1. An ID=2 is allocated to the error-resilient arithmetic coding technique.
+
+The associated P<sub>ID</sub> in the EPC marker field is composed of a variable number of 16 bits words that represent the entropy coding parameters associated with each code-block (see Table A.2). The code-block order is as specified in Annex B/JPEG 2000 Part 1. The first byte in P<sub>ID</sub> is the Forbidden Symbol Parameter (FSP), whereas the second one is the Soft Synchronization Parameter (SSP). It is not required to specify the P<sub>ID</sub> parameter for all code-blocks. The last (FSP, SSP) pair applies to all the remaining code-blocks. As an example, a single pair specifies the parameters for all the codestream.
+
+Table H.1 – EPC marker segment fields for error-resilient entropy coding
+
+| EPC marker field | Size in bits | Contents                                       |
+|------------------|--------------|------------------------------------------------|
+| ID               | 16           | 0000 0000 0000 0010                            |
+| L <sub>ID</sub>  | 16           | Length of the following PID parameter          |
+| P <sub>ID</sub>  | Variable     | A concatenation of parameters pairs (FSP, SSP) |
+
+Table H.2 – P<sub>ID</sub> parameters for error-resilient entropy coding
+
+| Error-resilient arithmetic coding parameters | Size in bits | Contents              |
+|----------------------------------------------|--------------|-----------------------|
+| FSP                                          | 8            | 0000 0000 – 1111 1010 |
+| SSP                                          | 8            | xxxx xabc             |
+
+## H.3 Binary encoding with forbidden symbol
+
+Binary Encoding with Forbidden Symbol is based on the Arithmetic entropy coding with forbidden symbols (MQF), which stems from the standard JPEG 2000 Part 1 entropy coder.
+
+#### H.3.1 MQF probability interval subdivision
+
+The probability interval is subdivided into three zones as shown in Table H.3. The first interval corresponds to the forbidden symbol (FS), which is never encoded and serves as an error-detection tool. The FS probability is  $Q_f$ , and it is represented on a 16-bit word, adopting the same convention used for LPS probability  $Q_e$  in Annex C/JPEG 2000 Part 1. The value of the FS probability is available from the FSP parameter in the EPC marker segment. In order to convert the FSP (8 bits) parameter to  $Q_f$  (16 bits), the FSP is multiplied by 0x56. In order to evaluate the corresponding decimal probability value,  $Q_f$  must be divided by  $(4/3)*0 \times 8000$ , as specified in Annex C/JPEG 2000 Part 1. The admissible FSP range is between 0x00 and 0xFA, being FSP=0x00 the default value that guarantees backward compatibility with MQ. Some conversion examples are reported in Table H.3.
+
+**Table H.3 – FSP conversion examples**
+
+| FSP  | $Q_f$  | FS decimal probability |
+|------|--------|------------------------|
+| 0x00 | 0x0000 | 0.000000               |
+| 0x01 | 0x0056 | 0.001968               |
+| 0x22 | 0x0B6C | 0.066925               |
+| 0xFA | 0x53FC | 0.492096               |
+
+The following encoding intervals are defined:
+
+- a) forbidden sub-interval  $Q_f \approx A \cdot Q_f$ ;
+- b) LPS sub-interval  $Q_e \approx A \cdot Q_e$ ;
+- c) MPS sub-interval  $A - Q_e - Q_f \approx A - A \cdot (Q_e + Q_f)$ .
+
+In order to use the FS, the standard LPS probability values  $Q_e$  (defined in Table C.2/JPEG 2000 Part 1) must be updated according to the following rule which corresponds to the multiplication of the decimal probability values by  $(1 - \text{FS probability})$ .
+
+$$Q_e = Q_e - \frac{Q_e * Q_f}{(4/3) * 0 \times 8000} = Q_e - (Q_e * Q_f * 3) \gg 17$$
+
+Note that the evaluation of the previous expression requires the multiplication of the 16 bit variables  $Q_e$ ,  $Q_f$  with sufficient bit precision. The  $Q_f$  value can be defined/overridden at component, tile and layer level and, consequently, the LPS probabilities table must be kept synchronized.
+
+The coding redundancy introduced by the FS is  $R_f = -\log_2 \left( 1 - \frac{Q_f}{(4/3) * 0 \times 8000} \right)$  bit per input symbol. Finally, it is worth pointing out that MQF is fully compliant with MQ in the case  $Q_f = 0 \times 0000$ .
+
+![Diagram illustrating MQF probability intervals. A horizontal line represents the probability interval A. It is divided into three segments: Q_f (Forbidden Symbol), Q_e (LPS), and A - Q_e - Q_f (MPS). The LPS segment is marked with an 'X' and labeled 'LPS'. The MPS segment is labeled 'MPS'. A dashed line labeled 'C' points to the LPS segment. The diagram is labeled T.810(06)_FH.1.](5879500ca01e1a2521654beff6c289a4_img.jpg)
+
+Diagram illustrating MQF probability intervals. A horizontal line represents the probability interval A. It is divided into three segments: Q\_f (Forbidden Symbol), Q\_e (LPS), and A - Q\_e - Q\_f (MPS). The LPS segment is marked with an 'X' and labeled 'LPS'. The MPS segment is labeled 'MPS'. A dashed line labeled 'C' points to the LPS segment. The diagram is labeled T.810(06)\_FH.1.
+
+**Figure H.1 – MQF probability intervals**
+
+#### H.3.2 Symbol encoding
+
+The presence of the FS implies a slight modification of the JPEG 2000 Part 1 arithmetic encoding steps. In particular, the CODELPS and CODEMPS procedures must be modified as shown in Figure H.2. The grey boxes represent add-on to JPEG 2000 Part 1 arithmetic encoding procedures, the dashed box represents the point where the JPEG 2000 Part 1 procedure must be used. At each symbol encoding  $Q_f$  must be subtracted from the A register, in order to obtain the MPS interval amplitude, and added to the C register, in order to skip the FS interval. The two gray boxes in the figure substitute the one box labelled  $[A=A-Q_c(I(CX))]$  in Figure C.6/T.800. The dashed box indicates that the procedure then continues from the solid box following  $[A=A-Q_c(I(CX))]$  in Figure C.6/T.800.
+
+![Flowchart of MQF coder: CODELPS (MPS) procedures. It starts with a box labeled CODELPS(MPS), followed by a grey box with the equation A = A - Q_c(I(CX)) - Q_f, then another grey box with the equation C = C + Q_f. A dashed arrow points down from the second grey box to a dashed diamond shape. The text T.810(06)_FH.2 is located to the right of the dashed arrow.](32ff77da4286b58c4778033acaa10836_img.jpg)
+
+```
+graph TD
+    A[CODELPS(MPS)] --> B["A = A - Qc(I(CX)) - Qf"]
+    B --> C["C = C + Qf"]
+    C -.-> D{ }
+    style B fill:#d3d3d3
+    style C fill:#d3d3d3
+    style D stroke-dasharray: 5 5
+```
+
+Flowchart of MQF coder: CODELPS (MPS) procedures. It starts with a box labeled CODELPS(MPS), followed by a grey box with the equation A = A - Q\_c(I(CX)) - Q\_f, then another grey box with the equation C = C + Q\_f. A dashed arrow points down from the second grey box to a dashed diamond shape. The text T.810(06)\_FH.2 is located to the right of the dashed arrow.
+
+Figure H.2 – MQF coder: CODELPS (MPS) procedures
+
+## H.4 Error-resilience segmentation symbols
+
+The error-detection and synchronization markers addition is defined as follows:
+
+- SEGMARK: original markers addition scheme: 1010 at the end of each bit-plane, i.e., at the end of each cleanup pass, arithmetically encoded with uniform probability.
+- SEGMARKPASS: addition of 1010 at the end of the significance propagation and magnitude refinement passes, arithmetically encoded with uniform probability.
+- SEGMARKSTRIPE  $n$ : addition of a marker at the end of each stripe, arithmetically encoded with uniform probability. If  $n$  is 1, the marker is 10, else if  $n$  is 2, the marker is 1010. Other values of  $n$  are not necessary.
+
+The presence of SEGMARKPASS and SEGMARKSTRIPE synchronization symbols is indicated through the SSP marker of Table H.4. The c bit is set to one to indicate the use of the SEGMARKPASS option. Its default value is 0. The SEGMARKSTRIPE 2 option is indicated by setting a and b bits to 1. If only one of those two bits is set to one, the SEGMARKSTRIPE 1 option is used. The default value of these two bits is 00. The other bits of the SSP marker are reserved. Examples of SSP values are provided in Table H.4.
+
+Table H.4 – SSP example values
+
+| SSP value | option                        |
+|-----------|-------------------------------|
+| 0000 0001 | SEGMARKPASS                   |
+| 0000 0010 | SEGMARKSTRIPE 1               |
+| 0000 0110 | SEGMARKSTRIPE 2               |
+| 0000 0111 | SEGMARKPASS + SEGMARKSTRIPE 2 |
+
+## H.5 Error detection
+
+#### H.5.1 Decoding in presence of errors
+
+The resilience tools described in this annex can be employed along with those adopted in JPEG 2000 Part 1 to provide the decoder with error-detection capabilities. The error-detection allows one to properly truncate the decoding of erroneous coding passes for a given code-block, thus preventing error propagation at the transformed coefficients level (see J.7/JPEG 2000 Part 1). In the following, the error-detection strategies based on MQF and error-resilience segmentation symbols are described.
+
+#### H.5.2 MQF error detection
+
+MQF decoding requires that the standard JPEG 2000 Part 1 DECODE procedure is modified as shown in Figure H.3. The modified MQF interval evaluation  $A = A - Q_e(I(CX)) - Q_f$  must be used. FS decoding allows for error detection. In fact, if the received code string happens to fall into the forbidden interval  $Chigh < Q_f$ , transmission errors are detected and concealment or correction strategies can be adopted. On the contrary, if no FS detection takes place, the *C* register is moved to the base of the LPS interval  $Chigh = Chigh = Q_f$ , and standard MQF decoding can be used.
+
+![Flowchart of the modified MQF decode procedure (Figure H.3). The process starts with a 'DECODE' block, followed by a calculation block: A = A - Qe(I(CX)) - Qf. A decision diamond asks 'Chigh < Qf'. If 'Yes', it leads to 'Error detected', which then leads to 'exit'. If 'No', it leads to a calculation block: C = C - Qf, followed by a dashed decision diamond: Chigh < Qe(I(CX)).](1e8c50ad4fca7f315a407347dd5091cc_img.jpg)
+
+```
+
+graph TD
+    DECODE[DECODE] --> Calc1["A = A - Qe(I(CX)) - Qf"]
+    Calc1 --> Decision{Chigh < Qf}
+    Decision -- No --> Calc2["C = C - Qf"]
+    Decision -- Yes --> Error[Error detected]
+    Error -.-> Exit([exit])
+    Calc2 -.-> DashedDecision{{Chigh < Qe(I(CX))}}
+    style DashedDecision stroke-dasharray: 5 5
+    subgraph Label [ ]
+    direction LR
+    T810[T.810(06)_FH.3]
+    end
+    style Label fill:none,stroke:none
+
+```
+
+Flowchart of the modified MQF decode procedure (Figure H.3). The process starts with a 'DECODE' block, followed by a calculation block: A = A - Qe(I(CX)) - Qf. A decision diamond asks 'Chigh < Qf'. If 'Yes', it leads to 'Error detected', which then leads to 'exit'. If 'No', it leads to a calculation block: C = C - Qf, followed by a dashed decision diamond: Chigh < Qe(I(CX)).
+
+**Figure H.3 – MQF decode procedure**
+
+#### H.5.3 Segmentation symbols error detection
+
+The correct decoding of the segmentation symbol confirms the correctness of the decoding up to this point in the codestream. If the segmentation symbol is not decoded correctly, then bit errors occur and proper countermeasures can be adopted.
+
+### H.6 Error correction
+
+The MQF and error resilience segmentation symbols allow to implement a JPWL decoder able to correct bit error at bitstream level.
+
+#### H.6.1 Bit-clock decoding
+
+The MQ decoder is described in Figure H.4. The compressed data **CD** and a context **CX** are input to the decoder to allow the output of a binary decision **D**. More precisely, in order to output the *i*th binary decision **d**[*i*] in the code-block, it is necessary to input the associated context **CX**[*i*] and a certain number of bits **CD**[ $n_{i-1}+1;n_i$ ] from the compressed data, where *i* is a generic index representing the scanning order of symbols into the code-block and  $n_i$  is the total number of bits that have been read when the decision **d**[*i*] has been decoded. The index *i* is referred to as the *symbol clock* and the decoder is said to be *symbol clock driven*.
+
+![Block diagram of a symbol clock-based arithmetic decoder. A box labeled 'DECODER' has two inputs on the left: 'CD[n_{i-1}+1;n_i]' and 'CX[i]'. It has one output on the right labeled 'd[i]'.](b44f89b176c971c7dd264c07bfef2c2a_img.jpg)
+
+```
+
+graph LR
+    CD["CD[n_{i-1}+1;n_i]"] --> DECODER[DECODER]
+    CX["CX[i]"] --> DECODER
+    DECODER --> d["d[i]"]
+
+```
+
+T.810(06)\_FH.4
+
+Block diagram of a symbol clock-based arithmetic decoder. A box labeled 'DECODER' has two inputs on the left: 'CD[n\_{i-1}+1;n\_i]' and 'CX[i]'. It has one output on the right labeled 'd[i]'.
+
+Figure H.4 – Symbol clock-based JPEG 2000 Part 1 arithmetic decoder
+
+For the purpose of error correction, it is convenient to switch to a *bit clock*-driven decoder. This change affects only the interface and not the decoder properties. The bit clock-based arithmetic decoder module accepts as input a single bit **CD**[*n*], where *n* represents the position in the bitstream and a variable number of contexts **CX** correspond to a variable number of output binary decisions **D**. This new representation is shown in Figure H.5, where  $i_n$  is the total number of decisions that have been decoded when *n* bits have been read from the compressed data.
+
+![Block diagram of a bit clock-based arithmetic decoder. A box labeled 'DECODER' has two inputs on the left: 'CD[n]' and 'CX[i_{n-1}+1;i_n]'. It has one output on the right labeled 'D[i_{n-1}+1;i_n]'.](48f209b7c0c1f91af40cfc3466dbd534_img.jpg)
+
+```
+
+graph LR
+    CD["CD[n]"] --> DECODER[DECODER]
+    CX["CX[i_{n-1}+1;i_n]"] --> DECODER
+    DECODER --> D["D[i_{n-1}+1;i_n]"]
+
+```
+
+T.810(06)\_FH.5
+
+Block diagram of a bit clock-based arithmetic decoder. A box labeled 'DECODER' has two inputs on the left: 'CD[n]' and 'CX[i\_{n-1}+1;i\_n]'. It has one output on the right labeled 'D[i\_{n-1}+1;i\_n]'.
+
+Figure H.5 – Bit clock-based JPEG 2000 Part 1 arithmetic decoder
+
+In order to implement such a decoder, the functions DECODE, RENORMD and INITDEC, shown respectively in Figures C.15, C.18 and C.20 of JPEG 2000 Part 1 are modified, as described in Figures H.6, H.7 and H.8.
+
+![Flowchart of the Bit clock-based DECODE procedure. The process starts with a 'DECODE' oval, followed by a rectangle 'i_n = i_{n-1}', then a 'RENORMD' rectangle. A decision diamond 'A AND 0x8000 = 0?'. If 'Yes', it goes to the 'Return D[i_{n-1}+1; i_n]' oval. If 'No', it goes to 'A = A - Qe(I(CX))', then another decision 'Chigh < Qe(I(CX))?'. If 'Yes', it goes to 'i_n = i_n + 1; D[i_n] = LPS_EXCHANGE'. If 'No', it goes to 'Chigh = Chigh - Qe(I(CX))', then a third decision 'A AND 0x8000 = 0?'. If 'Yes', it goes to 'i_n = i_n + 1; D[i_n] = MPS_EXCHANGE'. If 'No', it goes to 'i_n = i_n + 1; D[i_n] = MPS(CX)'. All three paths for the third decision lead to the 'Return D[i_{n-1}+1; i_n]' oval. A feedback loop connects the 'Return' oval back to the first decision diamond.](41aef1f5efab13d4f38f69e86c726062_img.jpg)
+
+```
+
+graph TD
+    DECODE([DECODE]) --> In[in = in-1]
+    In --> RENORMD[RENORMD]
+    RENORMD --> AZero{A AND 0x8000 = 0 ?}
+    AZero -- Yes --> Return([Return D[in-1+1; in]])
+    AZero -- No --> ASub[A = A - Qe(I(CX))]
+    ASub --> Chigh{Chigh < Qe(I(CX)) ?}
+    Chigh -- Yes --> InLPS[in = in + 1  
+D[in] = LPS_EXCHANGE]
+    Chigh -- No --> ChighSub[Chigh = Chigh - Qe(I(CX))]
+    ChighSub --> AZero2{A AND 0x8000 = 0 ?}
+    AZero2 -- Yes --> InMPSEx[in = in + 1  
+D[in] = MPS_EXCHANGE]
+    AZero2 -- No --> InMPS[in = in + 1  
+D[in] = MPS(CX)]
+    InLPS --> Return
+    InMPSEx --> Return
+    InMPS --> Return
+    Return --> AZero
+  
+```
+
+T.810(06)\_FH.6
+
+Flowchart of the Bit clock-based DECODE procedure. The process starts with a 'DECODE' oval, followed by a rectangle 'i\_n = i\_{n-1}', then a 'RENORMD' rectangle. A decision diamond 'A AND 0x8000 = 0?'. If 'Yes', it goes to the 'Return D[i\_{n-1}+1; i\_n]' oval. If 'No', it goes to 'A = A - Qe(I(CX))', then another decision 'Chigh < Qe(I(CX))?'. If 'Yes', it goes to 'i\_n = i\_n + 1; D[i\_n] = LPS\_EXCHANGE'. If 'No', it goes to 'Chigh = Chigh - Qe(I(CX))', then a third decision 'A AND 0x8000 = 0?'. If 'Yes', it goes to 'i\_n = i\_n + 1; D[i\_n] = MPS\_EXCHANGE'. If 'No', it goes to 'i\_n = i\_n + 1; D[i\_n] = MPS(CX)'. All three paths for the third decision lead to the 'Return D[i\_{n-1}+1; i\_n]' oval. A feedback loop connects the 'Return' oval back to the first decision diamond.
+
+Figure H.6 – Bit clock-based DECODE procedure
+
+![Flowchart of the RENORMD procedure. It starts with an oval 'RENORMD', followed by a decision diamond 'CT = 0?'. If 'Yes', it goes to a rectangle 'BYTEIN', then to a rectangle containing 'A = A << 1', 'C = C << 1', and 'CT = CT - 1', and finally to an oval 'Done'. If 'No', it bypasses 'BYTEIN' and goes directly to the processing rectangle before reaching 'Done'.](b9c0d46c1148cf65cb79f27fac420981_img.jpg)
+
+```
+
+graph TD
+    RENORMD([RENORMD]) --> CT0{CT = 0 ?}
+    CT0 -- Yes --> BYTEIN[BYTEIN]
+    CT0 -- No --> Shift
+    BYTEIN --> Shift[A = A << 1  
+C = C << 1  
+CT = CT - 1]
+    Shift --> Done([Done])
+  
+```
+
+T.810(06)\_FH.7
+
+Flowchart of the RENORMD procedure. It starts with an oval 'RENORMD', followed by a decision diamond 'CT = 0?'. If 'Yes', it goes to a rectangle 'BYTEIN', then to a rectangle containing 'A = A << 1', 'C = C << 1', and 'CT = CT - 1', and finally to an oval 'Done'. If 'No', it bypasses 'BYTEIN' and goes directly to the processing rectangle before reaching 'Done'.
+
+Figure H.7 – Bit clock-based RENORMD procedure
+
+![Flowchart of the INITDEC procedure. It starts with an oval 'INITDEC', followed by a rectangle 'BP = BPST, C = B << 16', then a rectangle 'BYTEIN', then a rectangle 'C = C >> 8, CT = 16, A = 0x0001', and finally to an oval 'Done'.](a003ffe7299e0a48bceb7f1e45a4f1a3_img.jpg)
+
+```
+
+graph TD
+    INITDEC([INITDEC]) --> BP[BP = BPST  
+C = B << 16]
+    BP --> BYTEIN[BYTEIN]
+    BYTEIN --> Shift[C = C >> 8  
+CT = 16  
+A = 0x0001]
+    Shift --> Done([Done])
+  
+```
+
+T.810(06)\_FH.8
+
+Flowchart of the INITDEC procedure. It starts with an oval 'INITDEC', followed by a rectangle 'BP = BPST, C = B << 16', then a rectangle 'BYTEIN', then a rectangle 'C = C >> 8, CT = 16, A = 0x0001', and finally to an oval 'Done'.
+
+Figure H.8 – Bit clock INITDEC procedure
+
+Actually, all the possible symbols which can be identified, given the input bit  $CD[n]$ , are decoded. This approach allows sequential decoding to be performed on a bit-clock basis. It can be modelled as a state transition automaton described in Figure H.9. A state  $\sigma[n]$  may contain all necessary internal state information, for example, arithmetic decoder states. The transition between state  $\sigma[n-1]$  and  $\sigma[n]$  is triggered by the bit  $CD[n]$ . A variable number of output binary decisions **D** is associated to this transition.
+
+![Figure H.9: State transition automaton representation of the decoding process. The diagram shows a sequence of states represented by circles. The first state is labeled σ[0], i_0. It has an incoming arrow from below labeled CD[1] and an outgoing arrow to the right. The second state is labeled σ[1], i_1. It has an incoming arrow from below labeled CD[1] and an outgoing arrow to the right. Above the second state is a circle labeled D[1; i_1]. An arrow points from the second state to this circle. The sequence continues with ellipses, then a state labeled σ[n-1], i_{n-1} with an incoming arrow from below labeled CD[n-1] and an outgoing arrow to the right. Above it is a circle labeled D[i_{n-2}+1; i_{n-1}]. Then a state labeled σ[n], i_n with an incoming arrow from below labeled CD[n] and an outgoing arrow to the right. Above it is a circle labeled D[i_{n-1}+1; i_n]. The sequence ends with ellipses, then a state labeled σ[N], i_N with an incoming arrow from below labeled CD[N] and an outgoing arrow to the right. Above it is a circle labeled D[i_{N-1}+1; i_N]. The diagram is labeled T.810(06)_FH.9 in the bottom right corner.](ae0a735d106290c594b0bafb1f5e72e7_img.jpg)
+
+Figure H.9: State transition automaton representation of the decoding process. The diagram shows a sequence of states represented by circles. The first state is labeled σ[0], i\_0. It has an incoming arrow from below labeled CD[1] and an outgoing arrow to the right. The second state is labeled σ[1], i\_1. It has an incoming arrow from below labeled CD[1] and an outgoing arrow to the right. Above the second state is a circle labeled D[1; i\_1]. An arrow points from the second state to this circle. The sequence continues with ellipses, then a state labeled σ[n-1], i\_{n-1} with an incoming arrow from below labeled CD[n-1] and an outgoing arrow to the right. Above it is a circle labeled D[i\_{n-2}+1; i\_{n-1}]. Then a state labeled σ[n], i\_n with an incoming arrow from below labeled CD[n] and an outgoing arrow to the right. Above it is a circle labeled D[i\_{n-1}+1; i\_n]. The sequence ends with ellipses, then a state labeled σ[N], i\_N with an incoming arrow from below labeled CD[N] and an outgoing arrow to the right. Above it is a circle labeled D[i\_{N-1}+1; i\_N]. The diagram is labeled T.810(06)\_FH.9 in the bottom right corner.
+
+Figure H.9 – State transition automaton representation of the decoding process
+
+#### H.6.2 Bitstream error correction
+
+When the encoded bitstream **CD**, output by the arithmetic coder, is transmitted across a noisy channel, the JPWL decoder observes a corrupted version of the bitstream **CD**. The error-detection tools previously described are used to identify the presence of bit errors. In such a case, JPWL decoder attempts error-correction by means of bit-clock decoding and sequential search techniques. At each bit depth  $n$  in the decoding automaton, shown in Figure H.9, a set of possible candidate bitstreams **CD<sub>k</sub>** is considered. Some memory space addressed by  $k$  is used to store the set of candidate bitstreams. Each bitstream candidate **CD<sub>k</sub>** with its corresponding decoded decisions **D<sub>k</sub>**, is ranked according to a proper metric  $M_k(n)$ , which allows the selection of the most probable candidate bitstream **CD**, corresponding to the correct decisions **D**.
+
+#### H.6.3 Metrics
+
+##### H.6.3.1 MAP metric
+
+The *maximum a posteriori* (MAP) probability for the bitstream **CD<sub>k</sub>** with bit depth  $n$  is defined as:
+
+$$P(D_k[1; i_n] | \underline{CD}[1; n]) \propto P(D_k[1; i_n]) \cdot P(\underline{CD}[1; n] | CD_k[1; n])$$
+
+The JPWL decoder uses the following MAP metric:
+
+$$M_k(n) = \log [P(D_k[1; i_n]) \cdot P(\underline{CD}[1; n] | CD_k[1; n])]$$
+
+In the presence of a memoryless channel, and assuming an order-1 Markov model for the decision bits, the metric  $M_k(n)$  can be computed according to the state transition automaton as follows:
+
+$$\begin{cases} M_k(0) = 0 \\ M_k(n) = M_k(n-1) + \sum_{j=i_{n-1}}^{i_n} \log [P(D_k[j] | D_k[1; j-1])] + \log [P(\underline{CD}[n] | CD_k[n])] \end{cases}$$
+
+The term  $P(D_k[i] | D_k[1; i-1])$  represents the *a priori* probability of the decision bits and it is estimated by means of the binary contextual model of the Coefficient bit modelling, which approximates the LPS probability with the  $Q_e$  values, defined by the arithmetic coder. The log of the source model probabilities can be pre-computed and stored in a table in order to speed up the metric evaluation. The term  $P(\underline{CD}[n] | CD_k[n])$  represents the channel transition probability. Clearly, the defined metric requires the definition of a channel model whose state must be available at the receiver; nevertheless, when this information is not available, the simplified metrics described in H.6.3.2 and H.6.3.3, can be used.
+
+##### H.6.3.2 Hamming distance
+
+The Hamming metric is defined as the Hamming distance between the received **CD** and the candidate **CD<sub>k</sub>** bitstreams. The Hamming additive metric is defined as  $M_k(n) = M_k(n-1) - \underline{CD}[n] \oplus CD_k[n]$ , where  $\oplus$  represents modulo 2 summation.
+
+This simple distance metric can be employed when the bitstream is transmitted across a binary input/binary output channel, and no feedback information (channel model, bit error rates, etc.) is available at the decoder.
+
+##### H.6.3.3 Euclidean distance
+
+The Euclidean metric can be used when the bitstream is transmitted across a channel with binary input and real output. In this case, the additive metric is  $M_k(n) = M_k(n-1) - | \underline{CD}^S[n] - \text{soft}(CD_k[n]) |$ , where  $\underline{CD}^S[n]$  is the received soft value corresponding to bit  $CD[n]$ , and  $\text{soft}(CD_k[n])$  is the transmitted soft value corresponding to bit  $CD_k[n]$ .
+
+#### H.6.4 Sequential search example
+
+In this clause an example of sequential search approach is described. The sequential search is based on the decoding tree shown in Figure H.10. Each node in the tree represents a bitstream candidate  $CD_k$ , decoded up to the bit depth  $n$ . For each depth, a maximum number of candidates MEM are stored for future recursions. At each iteration, all the stored candidates are extended one bit forward. In case of error detection, the candidate is pruned (see  $CD_3$  at bit depth  $n=2$  in Figure H.10). On the contrary, as long as the candidate bitstreams appear as correct, the decoding metrics  $M_k(n)$  are updated and only the best MEM candidates are stored for the next iteration. When the maximum bit depth for the current bitstream is reached, the best candidate in terms of the decoding metric is considered as the most likely bitstream  $CD$ .
+
+![Figure H.10: Sequential search example. A decoding tree diagram showing candidates M1(0)=0, M1(1), M2(1), M1(2), M2(2), M3(2) (pruned), and M4(2). A vertical arrow labeled MEM indicates the memory limit.](9cbc1ebd80813fc36e499f7d70ed6881_img.jpg)
+
+The diagram illustrates a sequential search decoding process. It starts with a root node  $M_1(0) = 0$ . From this node, two branches emerge based on the received bit  $CD_1[1]$ :
+ 
+
+- Branch 1:  $CD_1[1] = 0$  leads to node  $M_1(1)$ .
+- Branch 2:  $CD_2[1] = 1$  leads to node  $M_2(1)$ .
+
+ From  $M_1(1)$ , two branches emerge based on  $CD_2[2]$ :
+ 
+
+- Branch 1:  $CD_1[2] = 0$  leads to node  $M_1(2)$ .
+- Branch 2:  $CD_2[2] = 1$  leads to node  $M_2(2)$ .
+
+ From  $M_2(1)$ , two branches emerge based on  $CD_3[2]$  and  $CD_4[2]$ :
+ 
+
+- Branch 1:  $CD_3[2] = 0$  leads to node  $M_3(2)$ , which is marked with a large 'X' and a dashed box indicating "Error detected: candidate is pruned".
+- Branch 2:  $CD_4[2] = 1$  leads to node  $M_4(2)$ .
+
+ A vertical double-headed arrow on the right side, labeled "MEM", spans the height of the tree from the root level to the level of  $M_3(2)$  and  $M_4(2)$ , indicating the maximum number of candidates stored at each depth.
+
+Figure H.10: Sequential search example. A decoding tree diagram showing candidates M1(0)=0, M1(1), M2(1), M1(2), M2(2), M3(2) (pruned), and M4(2). A vertical arrow labeled MEM indicates the memory limit.
+
+Figure H.10 – Sequential search example
+
+# Annex I
+
+## Unequal error protection
+
+(This annex forms an integral part of this Recommendation | International Standard)
+
+### I.1 Introduction
+
+The objective of this informative annex is to explain how, using the normative tools of JPWL, it is possible to apply Unequal Error Protection (UEP) on a JPEG 2000 codestream. This UEP can take advantage of the Error Sensitivity Descriptor information for selecting the most appropriate technique for protecting the different parts of a JPEG 2000 codestream. UEP can be applied in different ways: inside the codestream, thanks to the flexible structure of the Error Protection Block, or it can be done by separating the JPEG 2000 codestream in different parts, each of them being protected differently, and sent to different error-prone environments.
+
+### I.2 Use of error-sensitivity descriptor as input information to unequal error-protection systems
+
+The Error Sensitivity Descriptor allows the selection of the most appropriate technique for protecting each part of the JPEG 2000 codestream by signalling the error-sensitivity of the respective parts. The most important parts of the codestream are then protected with a larger redundancy than the less important parts of the codestream. This error-protection can be applied by a process outside the scope of this Recommendation | International Standard, or using the Error-Protection Block as defined in clause I.3.
+
+### I.3 Use of Error Protection Block (EPB) for unequal error protection
+
+The LDPePB parameter of the EPB marker segment that may be present in a tile-part header, can address data which are outside the tile-part header boundary. This allows the inclusion of the JPEG 2000 bitstream in the error-protection data range, including or not the packet headers, depending on the use of the packed packet feature of JPEG 2000 Part 1.
+
+The PePB parameter of each EPB marker segment can be used to describe which error-correction technique is used to protect the different parts of the bitstream. Each successive EPB marker segment can use a different PePB configuration, be it either a selection of a code within the same error-correction code family, or the use of several techniques. As a matter of fact, each EPB marker segment may contain various redundant data that will allow for the different parts of the bitstream, to which they refer, to be protected against errors. In the example given in Figure I.1, EPB0 is protecting the tile-part header marker segments, and EPB1 to EPBn are protecting parts L1 to Ln of the bitstream.
+
+The predefined codes, as well as the default codes, can be used for this purpose. If other error-correction codes are used, they must be signalled in the EPC marker segment.
+
+![Diagram illustrating the use of EPB for unequal error protection. The diagram shows a sequence of data blocks: SOT, EPB0, EPBn, Tile-part header marker segments, SOD, and Packet data. The Packet data is divided into parts L0, L1, and Ln. The EPB0 segment is shown protecting the Tile-part header marker segments. The EPBn segment is shown protecting the Packet data. The diagram is labeled T.810(06)_F1.1.](ae375ead8aa673286b534e079e9a8533_img.jpg)
+
+The diagram illustrates the structure of a JPEG 2000 codestream with unequal error protection. It shows a sequence of data blocks: SOT, EPB0, EPBn, Tile-part header marker segments, SOD, and Packet data. The Packet data is divided into parts L0, L1, and Ln. The EPB0 segment is shown protecting the Tile-part header marker segments. The EPBn segment is shown protecting the Packet data. The diagram is labeled T.810(06)\_F1.1.
+
+Diagram illustrating the use of EPB for unequal error protection. The diagram shows a sequence of data blocks: SOT, EPB0, EPBn, Tile-part header marker segments, SOD, and Packet data. The Packet data is divided into parts L0, L1, and Ln. The EPB0 segment is shown protecting the Tile-part header marker segments. The EPBn segment is shown protecting the Packet data. The diagram is labeled T.810(06)\_F1.1.
+
+Figure I.1 – Use of EPB for unequal error protection
+
+# Annex J
+
+## Interoperability with ISO/IEC 15444
+
+(This annex forms an integral part of this Recommendation | International Standard)
+
+## J.1 Interoperability with ISO/IEC 15444-1
+
+JPWL tools are fully backward compatible with JPEG 2000 Part 1 in the sense of backward compatible and backward compatible with extensions as defined in clause 3. This annex is informative only.
+
+## J.2 Interoperability with ISO/IEC 15444-3
+
+All the JPWL tools, acting at the codestream level, can be used for enhancing the robustness of Motion JPEG 2000 in the presence of errors. A possible use of JPWL is to protect each of the individual codestreams.
+
+## J.3 Interoperability with ISO/IEC 15444-8 (JPSEC)
+
+Secure JPEG 2000 or JPSEC (ISO/IEC 15444-8) extends the baseline JPEG 2000 specification to provide a standardized framework for secure imaging. This framework enables the efficient integration and use of the tools needed to secure digital images, such as content protection, data integrity check, authentication, and conditional access control. The framework is open and flexible, hence ensuring a straight path for future extensions.
+
+JPSEC enables the use of security tools supporting a number of security services, including:
+
+- confidentiality;
+- integrity verification;
+- source authentication;
+- conditional access;
+- secure scalable streaming and secure transcoding;
+- registered content identification.
+
+JPSEC defines two marker segments: SEC and INSEC.
+
+The SEC marker segment is present in the main header and is mandatory. It gives overall information about the security tools which have been applied to secure the image. More specifically, SEC indicates the JPSEC tools used to secure the image, along with some parameters referring to the technique used. Among other things, these parameters can indicate which parts of the codestream have been secured.
+
+The INSEC marker segment provides with an additional means of transmitting parameters for one of the security tools declared in SEC, in order to complement the information in the main header. It can be placed in the codestream data and is optional. It uses the fact that the arithmetic decoder in JPEG 2000 stops reading bytes when it encounters a termination marker (i.e., two bytes with a value greater than 0xFF8F).
+
+#### J.3.1 General relationship between JPWL and JPSEC
+
+The combination of JPWL and JPSEC is required whenever JPEG 2000 images need to be secured and transmitted over an error-prone wireless channel.
+
+At the transmitter side, JPWL error sensitivity is typically generated during JPEG 2000 encoding. JPSEC tools are then applied to the codestream in order to secure it. Finally JPWL encoding tools are used to make the codestream more robust to transmission errors.
+
+At the receiver side, JPWL decoding tools are first applied to correct possible transmission errors. During this step, JPWL may also generate residual errors information. Finally, JPSEC tools are applied in order to fulfil the selected security services.
+
+![Figure J.1 – Typical JPWL and JPSEC combination. The diagram illustrates the flow of data from an image through various processing blocks. An 'image' input goes into a 'JPEG 2000 encoder' and a 'JPWL error sensitivity' block. The output of the 'JPEG 2000 encoder' goes into a 'JPSEC creator' block. The output of the 'JPWL error sensitivity' block also goes into the 'JPSEC creator' block. The output of the 'JPSEC creator' block goes into a 'JPWL encoder' block. The output of the 'JPWL encoder' block is labeled 'JPSEC/JPWL codestream'. This codestream goes into an 'error-prone wireless channel' block. The output of the 'error-prone wireless channel' block is labeled 'JPSEC/JPWL codestream with possible errors'. This codestream goes into a 'JPWL decoder' block. The output of the 'JPWL decoder' block goes into a 'JPWL residual errors' block. The output of the 'JPWL residual errors' block goes into a 'JPSEC consumer' block. The output of the 'JPSEC consumer' block is labeled 'JPSEC/JPWL codestream with possible errors'. The diagram also includes a reference 'T.810(06)_FJ.5'.](fc02903382cebe6fc11e4c0d74b5313f_img.jpg)
+
+```
+
+graph LR
+    image --> JPEG2000[JPEG 2000 encoder]
+    JPWLE[JPWL error sensitivity] --> JPSECcreator[JPSEC creator]
+    JPEG2000 --> JPSECcreator
+    JPSECcreator -- 1 --> JPWLEnc[JPWL encoder]
+    JPWLEnc -- JPSEC/JPWL codestream --> channel[error-prone wireless channel]
+    channel -- "JPSEC/JPWL codestream with possible errors" --> JPWLdec[JPWL decoder]
+    JPWLdec --> JPWLres[JPWL residual errors]
+    JPWLres -- 2 --> JPSECcons[JPSEC consumer]
+    JPSECcons -- JPSEC/JPWL codestream with possible errors --> JPWLdec
+    JPWLdec -.-> T810[T.810(06)_FJ.5]
+  
+```
+
+Figure J.1 – Typical JPWL and JPSEC combination. The diagram illustrates the flow of data from an image through various processing blocks. An 'image' input goes into a 'JPEG 2000 encoder' and a 'JPWL error sensitivity' block. The output of the 'JPEG 2000 encoder' goes into a 'JPSEC creator' block. The output of the 'JPWL error sensitivity' block also goes into the 'JPSEC creator' block. The output of the 'JPSEC creator' block goes into a 'JPWL encoder' block. The output of the 'JPWL encoder' block is labeled 'JPSEC/JPWL codestream'. This codestream goes into an 'error-prone wireless channel' block. The output of the 'error-prone wireless channel' block is labeled 'JPSEC/JPWL codestream with possible errors'. This codestream goes into a 'JPWL decoder' block. The output of the 'JPWL decoder' block goes into a 'JPWL residual errors' block. The output of the 'JPWL residual errors' block goes into a 'JPSEC consumer' block. The output of the 'JPSEC consumer' block is labeled 'JPSEC/JPWL codestream with possible errors'. The diagram also includes a reference 'T.810(06)\_FJ.5'.
+
+**Figure J.1 – Typical JPWL and JPSEC combination**
+
+### J.3.2 Specific issues on interoperability between JPWL and JPSEC
+
+A number of issues have to be considered for interoperability between JPWL and JPSEC, as detailed hereafter:
+
+- 1) JPWL Error-Protection Capability (EPC): the presence of this marker segment will affect byte ranges. Note that this marker segment is mandatory in a JPWL codestream.
+- 2) JPWL Error-Protection Block (EPB): this marker segment is typically added as the last step at the transmitter and removed as the first step at the receiver. In principle, it should not affect JPSEC.
+- 3) JPWL Error-Sensitivity Descriptor (ESD): this marker segment is typically added during JPEG 2000 part 1 encoding, in which case it will be transparent to subsequent JPSEC operations. However, JPSEC could adversely affect the use of ESD in JPWL. In particular, JPSEC should not change byte ranges whenever ESD uses byte ranges. In addition, the JPSEC operations should not affect distortion values; otherwise the information carried by ESD becomes irrelevant. In the latter case, the JPSEC creator has the option to remove the ESD marker segment.
+- 4) JPWL Residual Error Descriptor (RED): this marker segment can be inserted after JPWL decoding. It may, therefore, affect JPSEC byte ranges. It may also impact JPSEC integrity authentication techniques. In case of a corrupted codestream, the RED information can be useful for a JPSEC consumer to appropriately handle it.
+- 5) JPSEC SEC: the presence of this marker segment will affect byte ranges. Note that this marker segment is mandatory in a JPSEC codestream.
+- 6) JPSEC INSEC: the presence of this marker segment will affect byte ranges. Note that this marker segment appears in the codestream data.
+
+In the case when there are no residual errors, the JPWL encoder and decoder should ideally be transparent. In other words, in this case, the streams at points 1 and 2 in Figure J.1 should be strictly identical.
+
+As a general recommendation, when used in combination with JPWL, it is preferable for JPSEC to use byte ranges beginning after the SOD marker in order to minimize problems with byte ranges. In addition, it is preferable to restrict the presence of JPWL marker segments to the main header and to avoid their presence in the tile-part headers.
+
+# Annex K
+
+## Registration authority
+
+(This annex forms an integral part of this Recommendation | International Standard)
+
+## K.1 General introduction
+
+The JPWL registration mechanism provides for the unambiguous identification of non-normative security tools that follow the JPWL standard and that can be further proposed or developed as non-normative JPWL tools. This registration is performed by a JPWL Registration Authority. It shall conform to JTC 1 Directives, Chapter 18. The registration of these new JPWL tools is controlled by the process defined in this annex.
+
+Applicants may submit technologies that they would like included in the JPWL reference list. Note that the JPWL tool use is specified with the JPWL EPC marker segment present in the codestream (see Annexes A and C). When an application finds an unknown JPWL ID, if possible, it can hook up to a JPWL RA and get the registered information about the tool.
+
+## K.2 Criteria for eligibility of applicants for registration
+
+Eligible applicants shall be organizations acknowledged by their National bodies.
+
+## K.3 Applications for registration
+
+Applications for registering new JPWL tools shall be published by a JPWL Registration Authority. This publication shall contain forms for Registration Application, Request for Update, Notification of Assignment or Update, and Rejection of Application.
+
+All forms shall include:
+
+- name of applicant organization;
+- address of applicant organization;
+- the name, title, postal/e-mail address, telephone/facsimile number of a contact person within the organization.
+
+Forms for Registration Application and Request for Update shall also include:
+
+- JPWL tool name (mandatory);
+- Type of JPWL tool;
+- Descriptive technical abstract (mandatory);
+- Descriptive overview of the tool (mandatory);
+- Operational example use case description (optional);
+- Parameters syntax specification, including possible values (optional);
+- Guidelines for optimum usage (optional);
+- IPR status, e.g., owner, right holder (optional);
+- IPR conditions for use (mandatory);
+- Restrictions of use, e.g., export conditions (optional);
+- Information for downloads of implementations (optional);
+- Additional comments, motivation, references... (optional);
+- Requirements for confidentiality of selected application entries (optional);
+- Requested length of time for tool registration (optional).
+
+The JPWL Registration Authority shall also provide tutorial material to assist applicants in preparing applications.
+
+## **K.4 Review and response to applications**
+
+This clause defines the process for the JPWL Registration Authority to review and respond to applications to ensure fairness.
+
+A technical review committee is set up to review the applications. This committee is composed of ISO/IEC JTC 1/SC 29/WG 1 members and JPWL Registration Authority members. The review committee examines applications at a WG 1 meeting not later than nine months after the application was submitted.
+
+The review committee accepts or rejects the application, based on the rejection criteria in K.4.1.
+
+If accepted, the new JPWL tool is allocated an identifier (ID) as specified in Annex C and considered as referenced. The review committee approves the JPWL tool description information. The ID shall then be used for signalling in the JPEG 2000 codestream using the EPC maker segment (see Annexes A and C).
+
+Once the application has been reviewed and accepted, the JPWL RA notifies the applicant of a positive or negative response to the registration request. The response to the applicant shall include a short explanation of the results of the technical review and shall be sent back to applicants no later than nine months after the date of application.
+
+A negative response may be appealed if the registrant believes that there was an error made in the rejection, or when further information is required to clarify issues or concerns. If the registrant requires additional review beyond the Authority's process, he may submit his case for review by the broader WG 1 committee at the next appropriate WG 1 group meeting. He may then be required to provide additional information at the request of the experts who, under the authority of WG 1, will provide a final, definitive response of acceptance or rejection. In order to have a rejected application reviewed by WG 1, the registrants must re-submit the proposal through their National body, specifying why the submission requires consideration by WG 1.
+
+#### **K.4.1 Rejection of applications**
+
+The criteria for rejection of an application are the following:
+
+- The applicant is not eligible;
+- The proper fees are not paid (when relevant);
+- An approved, registered item already exists that contains the identical contents of the submission;
+- The information in the application is incomplete or incomprehensible;
+- The justification for inclusion in the register is not adequate. The candidate JPWL tool should demonstrate it provides a useful security service and give examples of use cases when relevant;
+- The Authority considers that there is not enough originality in the proposed tool which could easily be implemented with an existing, approved item;
+- The submission contains errors, or is not compliant with the normative parts of JPWL;
+- The technical description is not sufficient;
+- The confidentiality conditions are not appropriate.
+
+#### **K.4.2 Assignment of identifiers and recording of object definitions**
+
+The review process and above syntax ensure that the assigned ID is unique within the register and that the same ID is not assigned to another object.
+
+After the assignment has been made, the ID and associated information shall be included in the register and the JPWL Registration Authority shall inform the applicant of the assignment within nine months.
+
+The JPWL tool definition shall be recorded in the register at the time when the ID is assigned.
+
+Identifiers may be reused by a Registration Authority. For example, identifiers become available for re-use after their expiration or when they are given up voluntarily or reclaimed. ID owners may voluntarily give up their ID through a Request for Update.
+
+A JPWL Registration Authority may reclaim an identifier for technical reasons or for tool misuse. When this occurs, Identifier owners will be notified by a Notification of Update.
+
+## **K.5 Maintenance**
+
+For the purpose of maintenance of the register, a JPWL Registration Authority shall implement mechanisms for maintaining the integrity of the register, including adequate backup for retaining records.
+
+An ID owner may update the associated JPWL tool information through a Request for Update. A JPWL Registration Authority shall provide mechanisms for maintaining confidentiality of entries as granted in the application.
+
+## **K.6 Publication of the register**
+
+Generally, the interests of the community of information technology users is best served if the register information is made public. In certain cases, however, there may be a need for confidentiality of some or all of the data pertinent to a particular registration, either permanently or for some portion of the registration process.
+
+A JPWL Registration Authority shall publish the registry information in a manner that is consistent with the confidentiality requirements of the JPWL tool.
+
+Where publication is required, electronic and printed paper versions are mandatory. If a JPWL Registration Authority is to provide publication, it shall keep accurate distribution records pertaining to its publications.
+
+#### **K.6.1 Register information requirements**
+
+The JPWL Registration Authority shall electronically publish the list of non-normative JPWL tools in its register, as well as the information associated with them, in a manner that is consistent with the confidentiality requirements of the JPWL tool.
+
+The following information shall be contained in the register for each JPWL tool:
+
+- the assigned ID;
+- name of initial applicant;
+- address of initial applicant;
+- date of original assignment;
+- date of last transfer of assignment, if allowed (updatable);
+- name of current owner (updatable);
+- address of current owner (updatable);
+- the name, title, postal/e-mail address, telephone/facsimile number of a contact person within the organization (updatable);
+- date of last update (updatable);
+
+It shall also contain the information provided by the applicant on its JPWL tool as specified in K.3 above.
+
+# **Annex L**
+
+## **Patent statement**
+
+(This annex does not form an integral part of this Recommendation | International Standard)
+
+There is the possibility that, for some of the processes specified in this Recommendation | International Standard, conformance or compliance may require use of an invention covered by patent rights. By publication of this Recommendation | International Standard, no position is taken with respect to the validity of this claim or of any patent rights in connection therewith. Information regarding such patents can be obtained from the any organizations. The table summarizes the formal patent and intellectual property rights statements that have been received.
+
+**Table L.1 – Received intellectual property rights statements**
+
+| Number | Company |
+|--------|---------|
+| 1      | Thales  |
+| 2      | INRIA   |
+
+# BIBLIOGRAPHY
+
+- [1] POULLIAT (C.), VILA (P.), PIREZ (D.) and FIJALKOW (I.): Progressive JPEG 2000 Image Transmission over noisy channel, *Eusipco 2002*, Toulouse, France, 3rd-6th September 2002.
+- [2] MOCCAGATTA (I.), SOUDAGAR (S.), LIANG (J.) and CHEN (H.): Error-Resilient Coding in JPEG-2000 and MPEG-4, *IEEE Journal on Selected Areas in Communications*, Vol. 18, No. 6, pp. 899-914, June 2000.
+- [3] HAGENAUER (J.): Rate-Compatible Punctured Convolutional Codes (RCPC Codes) and their applications, *IEEE Transactions on Communications*, Vol. 36, No. 4, pp. 389-400, April 1988.
+- [4] MORELOS-ZARAGOZA (R.H.), FOSSORIER (M.P.C.), LIN (S.) and IMAI (H.): Multilevel Coded Modulation for Unequal Error Protection and Multistage Decoding - Part I: Symmetric Constellations, *IEEE Transactions on Communications*, Vol. 48, No. 2, February 2000.
+- [5] NATU (A.), TAUBMAN (D.): Unequal Protection of JPEG 2000 Code-Streams in Wireless Channels, *Proceedings of IEEE GLOBECOM'02*, Vol. 1, pp. 534-538, Taipei, China, 17-21 November 2002.
+- [6] SANCHEZ (V.), MANDAL (M.K.): Robust transmission of JPEG 2000 images over noisy channels, *Proceedings of IEEE ICCE'02*, pp. 80-81, 2002.
+- [7] NICHOLSON (D.), LAMY-BERGOT (C.), NATUREL (X.) and POULLIAT (C.): JPEG 2000 backward compatible error protection with Reed-Solomon codes, *IEEE Transactions on Consumer Electronics*, Vol. 49, No. 4, pp. 855-860, November 2003.
+- [8] MACWILLIAMS (F.J.), SLOANE (N.J.A.): The Theory of Error-Correcting Codes, North-Holland: New York, NY, 1977.
+- [9] GRANGETTO (M.), MAGLI (E.) and OLMO (G.): Robust video transmission over error-prone channels via error correcting arithmetic codes, *IEEE Communications Letters*, Vol. 7, No. 12, pp. 596-598, December 2003.
+- [10] GUIONNET (T.), GUILLEMOT (C.): Soft decoding and synchronization of arithmetic codes: application to image transmission over noisy channels, *IEEE Transactions on Image Processing*, Vol. 12, No. 12, pp. 1599-1609, December 2003.
+- [11] PRESS (William H.), FLANNERY (Brian P.), TEUKOLSKY (Saul A.) and VETTERLING (William T.): Numerical Recipes in C: The Art of Scientific Computing, Second Edition, Cambridge University Press, Chapter 20, pp. 896-903.
+- [12] FRESCURA (F.), FECI (C.), GIORNI (M.) and CACOPARDI (S.): JPEG 2000 and MJPEG 2000 Transmission in 802.11 Wireless Local Area Networks, *IEEE Transactions on Consumer Electronics*, Vol. 49, No. 4, pp. 861-871, November 2003.
+- [13] NATU (A.), FRESIA (M.) and LAVAGETTO (F.): Transmission of JPEG 2000 Code-Streams over Mobile Radio Channels, *IEEE International Conference on Image Processing*, Vol. 1, pages 785-788, Genoa, Italy, September 2005.
+
+
+
+# SERIES OF ITU-T RECOMMENDATIONS
+
+|                 |                                                                                             |
+|-----------------|---------------------------------------------------------------------------------------------|
+| Series A        | Organization of the work of ITU-T                                                           |
+| Series D        | General tariff principles                                                                   |
+| Series E        | Overall network operation, telephone service, service operation and human factors           |
+| Series F        | Non-telephone telecommunication services                                                    |
+| Series G        | Transmission systems and media, digital systems and networks                                |
+| Series H        | Audiovisual and multimedia systems                                                          |
+| Series I        | Integrated services digital network                                                         |
+| Series J        | Cable networks and transmission of television, sound programme and other multimedia signals |
+| Series K        | Protection against interference                                                             |
+| Series L        | Construction, installation and protection of cables and other elements of outside plant     |
+| Series M        | Telecommunication management, including TMN and network maintenance                         |
+| Series N        | Maintenance: international sound programme and television transmission circuits             |
+| Series O        | Specifications of measuring equipment                                                       |
+| Series P        | Telephone transmission quality, telephone installations, local line networks                |
+| Series Q        | Switching and signalling                                                                    |
+| Series R        | Telegraph transmission                                                                      |
+| Series S        | Telegraph services terminal equipment                                                       |
+| <b>Series T</b> | <b>Terminals for telematic services</b>                                                     |
+| Series U        | Telegraph switching                                                                         |
+| Series V        | Data communication over the telephone network                                               |
+| Series X        | Data networks, open system communications and security                                      |
+| Series Y        | Global information infrastructure, Internet protocol aspects and next-generation networks   |
+| Series Z        | Languages and general software aspects for telecommunication systems                        |
\ No newline at end of file
diff --git a/marked/T/T-REC-T.813-201206-I_PDF-E/raw.md b/marked/T/T-REC-T.813-201206-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..adda45199272be0e9a698f7a07ff94a67b8b1163
--- /dev/null
+++ b/marked/T/T-REC-T.813-201206-I_PDF-E/raw.md
@@ -0,0 +1,10686 @@
+
+
+I n t e r n a t i o n a l   T e l e c o m m u n i c a t i o n   U n i o n
+
+# ITU-T
+
+TELECOMMUNICATION  
+STANDARDIZATION SECTOR  
+OF ITU
+
+# T.813
+
+(06/2012)
+
+SERIES T: TERMINALS FOR TELEMATIC SERVICES  
+Still-image compression – JPEG 2000
+
+---
+
+**Information technology – JPEG 2000 image  
+coding system – XML representation and  
+reference**
+
+Recommendation ITU-T T.813
+
+![ITU logo: a globe with red lightning bolts and the text 'ITU International Telecommunication Union'](6ed175c791b5e156d9c98a8dbcc3318c_img.jpg)
+
+The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue globe with two red lightning bolts striking it. To the right of the globe, the text "ITU" is written in a large, bold, blue font, and below it, the words "International Telecommunication Union" are written in a smaller, blue font.
+
+ITU logo: a globe with red lightning bolts and the text 'ITU International Telecommunication Union'
+
+# ITU-T T-SERIES RECOMMENDATIONS **TERMINALS FOR TELEMATIC SERVICES**
+
+|                                                     |                    |
+|-----------------------------------------------------|--------------------|
+| Facsimile – Framework                               | T.0–T.19           |
+| Still-image compression – Test charts               | T.20–T.29          |
+| Facsimile – Group 3 protocols                       | T.30–T.39          |
+| Colour representation                               | T.40–T.49          |
+| Character coding                                    | T.50–T.59          |
+| Facsimile – Group 4 protocols                       | T.60–T.69          |
+| Telematic services – Framework                      | T.70–T.79          |
+| Still-image compression – JPEG-1, Bi-level and JBIG | T.80–T.89          |
+| Telematic services – ISDN Terminals and protocols   | T.90–T.99          |
+| Videotext – Framework                               | T.100–T.109        |
+| Data protocols for multimedia conferencing          | T.120–T.149        |
+| Telewriting                                         | T.150–T.159        |
+| Multimedia and hypermedia framework                 | T.170–T.189        |
+| Cooperative document handling                       | T.190–T.199        |
+| Telematic services – Interworking                   | T.300–T.399        |
+| Open document architecture                          | T.400–T.429        |
+| Document transfer and manipulation                  | T.430–T.449        |
+| Document application profile                        | T.500–T.509        |
+| Communication application profile                   | T.510–T.559        |
+| Telematic services – Equipment characteristics      | T.560–T.649        |
+| <b>Still-image compression – JPEG 2000</b>          | <b>T.800–T.829</b> |
+| Still-image compression   JPEG XR                   | T.830–T.849        |
+| Still-image compression – JPEG-1 extensions         | T.850–T.899        |
+
+*For further details, please refer to the list of ITU-T Recommendations.*
+
+## **Information technology – JPEG 2000 image coding system – XML representation and reference**
+
+## **Summary**
+
+Recommendation ITU-T T.813 | ISO/IEC 15444-14 specifies an XML document, referred to as JPXML, which is designed primarily for representing JPEG 2000 file format and codestream marker segments, and a reference method for embedding internal binary data in a JPEG 2000 image.
+
+This Recommendation | International Standard:
+
+- specifies an XML schema for general box file formats;
+- specifies an XML schema for JPEG 2000 family file formats and codestream segments;
+- specifies a complete referring location path to address to exact box or codestream data in an image;
+- provides guidance on processes for converting source image data to an XML structural document;
+- provides guidance on how to implement these processes in practice.
+
+## **History**
+
+| Edition | Recommendation | Approval   | Study Group |
+|---------|----------------|------------|-------------|
+| 1.0     | ITU-T T.813    | 2012-06-29 | 16          |
+
+## FOREWORD
+
+The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis.
+
+The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics.
+
+The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1.
+
+In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC.
+
+## NOTE
+
+In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party.
+
+## INTELLECTUAL PROPERTY RIGHTS
+
+ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process.
+
+As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at <http://www.itu.int/ITU-T/ipr/>.
+
+© ITU 2013
+
+All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU.
+
+## CONTENTS
+
+|                                                                                      | <i>Page</i> |
+|--------------------------------------------------------------------------------------|-------------|
+| 1 Scope                                                                              | 1           |
+| 2 Normative references                                                               | 1           |
+| 2.1 Identical Recommendation   International Standards                               | 1           |
+| 2.2 Paired Recommendations   International Standards equivalent in technical content | 1           |
+| 2.3 Additional references                                                            | 2           |
+| 3 Definitions                                                                        | 2           |
+| 4 Abbreviations and symbols                                                          | 3           |
+| 4.1 Abbreviations                                                                    | 3           |
+| 5 Conventions                                                                        | 3           |
+| 6 General description                                                                | 4           |
+| 6.1 Structure of the JPXML document                                                  | 4           |
+| 6.2 Creation of a JPXML document                                                     | 5           |
+| 6.3 Access with the JPXML document                                                   | 6           |
+| 7 Document creation rules                                                            | 7           |
+| 7.1 Common rule                                                                      | 7           |
+| 7.2 Element name rule for box format                                                 | 8           |
+| 7.3 Element name rule for a tagged image format                                      | 8           |
+| 7.4 Element name rule for a marker segment                                           | 9           |
+| 7.5 Element type attributes                                                          | 9           |
+| 8 Accessing image data                                                               | 10          |
+| 8.1 Rules for location conversion                                                    | 10          |
+| 8.2 Example of location conversion                                                   | 11          |
+| Annex A – JPXML elements for box file format                                         | 13          |
+| A.1 Introduction                                                                     | 13          |
+| A.2 Box element definitions                                                          | 13          |
+| A.3 Examples of XML schemas                                                          | 33          |
+| Annex B – JPXML elements for codestream marker segments                              | 61          |
+| B.1 Introduction                                                                     | 61          |
+| B.2 JPEG 2000 codestream marker element definitions                                  | 61          |
+| B.3 Examples of XML schemas                                                          | 68          |
+| Annex C – Examples and guidelines                                                    | 83          |
+| C.1 Software conventions for the box type                                            | 83          |
+| C.2 Example of JPXML document conversion                                             | 84          |
+
+
+
+# **INTERNATIONAL STANDARD**
+
+## **RECOMMENDATION ITU-T**
+
+## **Information technology – JPEG 2000 image coding system – XML representation and reference**
+
+# **1 Scope**
+
+This Recommendation | International standard specifies an XML document, referred to as JPXML, which is designed primarily for representing JPEG 2000 file format and marker segments in the codestream, and a referring method for embedding internal data in a JPEG 2000 image.
+
+This Recommendation | International Standard
+
+- specifies JPXML conversion rules for general box file formats;
+- specifies JPXML conversion rules for JPEG 2000 family file formats and codestream segments;
+- specifies a complete referring location path to address to exact box or codestream data in an image;
+- provides guidance on processes for converting source image data to an XML structural document;
+- provides guidance on how to implement these processes in practice.
+
+# **2 Normative references**
+
+The following Recommendations and International Standards contain provisions which, through reference in this text, constitute provisions of this Recommendation | International Standard. At the time of publication, the editions indicated were valid. All Recommendations and Standards are subject to revision, and parties to agreements based on this Recommendation | International Standard are encouraged to investigate the possibility of applying the most recent edition of the Recommendations and Standards listed below. Members of IEC and ISO maintain registers of currently valid International Standards. The Telecommunication Standardization Bureau of the ITU maintains a list of currently valid ITU-T Recommendations.
+
+## **2.1 Identical Recommendation | International Standards**
+
+- Recommendation ITU-T T.800 (2002) | ISO/IEC 15444-1:2004, *Information technology – JPEG 2000 image coding system: Core coding system.*
+- Recommendation ITU-T T.801 (2002) | ISO/IEC 15444-2:2004, *Information technology – JPEG 2000 image coding system: Extensions.*
+- Recommendation ITU-T T.802 (2005) | ISO/IEC 15444-3:2007, *Information technology – JPEG 2000 image coding system: Motion JPEG 2000.*
+- Recommendation ITU-T T.805 (2012) | ISO/IEC 15444-6 (2013), *Information technology – JPEG 2000 image coding system: Compound image file format.*
+- Recommendation ITU-T T.807 (2006) | ISO/IEC 15444-8:2007, *Information technology – JPEG 2000 image coding system: Secure JPEG 2000.*
+- Recommendation ITU-T T.808 (2005) | ISO/IEC 15444-9:2005, *Information technology – JPEG 2000 image coding system: Interactivity tools, APIs and protocols.*
+- Recommendation ITU-T T.809 (2011) | ISO/IEC 15444-10:2011, *Information technology – JPEG 2000 image coding system: Extensions for three-dimensional data.*
+- Recommendation ITU-T T.810 (2006) | ISO/IEC 15444-11:2007, *Information technology – JPEG 2000 image coding system: Wireless.*
+- Recommendation ITU-T T.812 (2007) | ISO/IEC 15444-13:2008, *Information technology – JPEG 2000 image coding system: Wireless.*
+
+## **2.2 Paired Recommendations | International Standards equivalent in technical content**
+
+- Recommendation ITU-T T.832 (2009), *Information technology – JPEG XR image coding system: An entry level JPEG 2000 encoder.*  
+ISO/IEC 29199-2:2009, *Information technology – JPEG XR image coding system – Part 2: Image coding specification.*
+
+- Recommendation ITU-T T.833 (2010), *Information technology – JPEG XR image coding system – Motion JPEG XR*
+- ISO/IEC 29199-3:2010, *Information technology – JPEG XR image coding system – Part 3: Motion JPEG XR*.
+- ISO 12639:1998, *Graphic technology – Prepress digital data exchange – Tag image file format for image technology (TIFF/IT)*.
+
+## 2.3 Additional references
+
+- ISO/IEC 646:1991, *Information technology – ISO 7-bit coded character set for information interchange*.
+- ISO/IEC 15444-12:2012, *Information technology – JPEG 2000 image coding system – Part 12: ISO base media file format*.
+- IETF RFC 2045 (1996), *Multipurpose Internet Mail Extensions (MIME) Part One*.
+- IETF RFC 2279 (1998), *UTF-8, A transformation format of ISO 10646*.
+- IETF RFC 4648 (2006), *The Base16, Base32, and Base64 Data Encodings*.
+- W3C Recommendation (2009), *Namespaces in XML 1.0 (Third Edition)*.
+- W3C Recommendation (2008), *Extensible Markup Language (XML), Version 1.0 (Fifth Edition)*.
+- W3C Recommendation (2004), *XML Schema Part 0: Primer*.
+- W3C Recommendation (2004), *XML Schema Part 1: Structures*.
+- W3C Recommendation (2004), *XML Schema Part 2: Datatypes*.
+- W3C Recommendation (2010), *XML Path Language (XPath) 2.0*.
+
+## 3 Definitions
+
+For the purposes of this Recommendation | International Standard, the definitions given in Rec. ITU-T T.800 | ISO/IEC 15444-1 and Rec. ITU-T T.801 | ISO/IEC 15444-2 and those listed below apply. Should there be any difference between the definition given in this clause and the one given in one of the other Recommendation | International Standard cited above, the one given in this clause prevails.
+
+- 3.1**     ...: elision mark. This mark denotes that some words or characters are erased or abbreviated.
+- 3.2**     **4CC**: Four-character codes of the box type generally referred to by an ISO 646 character string translation of the integer value. This value is used for a box type that specifies its contents.
+- 3.3**     **absolute offset**: Offset to internal image data from the start of an image file. By the JPXML converter, the offset will be made with "length" attributes from the top to the target elements.
+- 3.4**     **box**: A sequence of byte blocks that contains its length, 4CC data type, and contents. Some boxes, such as the "jp2c" box, contain an image codestream; other boxes contain image properties such as image width and height. This data block is the atom of the JPEG 2000 and MPEG 4 image file format.
+- 3.5**     **box-based format**: A sequence of boxes that contains several image properties and expresses an image file format. This image format starts with a signature box and contains at least one codestream.
+- 3.6**     **box element**: A JPXML element for a box, and this element name is translated from the 4CC of the box type by using conversion rules described in clause 7.
+- 3.7**     **codestream**: A sequence of bits contained in a sequence of *bytes*, created by an image coder. This data sequence contains marker segments for holding image coding properties that are parsed by a decoder or translator. This may be arranged so that the most significant bit of the first *byte* is the first bit of the *codestream*, the next most significant bit of the first *byte* is the second bit of the *codestream*, and so on, to the least significant *bytes*.
+- 3.8**     **fat representation**: A JPXML document that contains whole image data on text nodes. This representation can be translated to a genuine image without any additional image information because it contains whole image information. However, because of translating whole chunk data into the XML format, this representation needs more data space than was required for the original image. For more details, see 6.1.
+- 3.9**     **fat-skeleton representation**: A JPXML document that contains image properties excluding codestream chunk data. This representation may have a location path to chunk image data by using the JPXML format. This represents a box file format image structure. For more details, see 6.1.
+
+**3.10 JPXML converter:** A converter that translates data between an image and a JPXML document. The JPXML "forward" converter translates an image to a JPXML document, and the JPXML "inverse" converter translates the edited document and codestream data to an image. These converters use rules of element name creation, defined container and undefined chunk container conversions.
+
+**3.11 JPXML document:** An XML document that corresponds to the box file format or codestream, categorized according to included contents; skeleton, fat-skeleton and fat representations. For more details, see 6.1.
+
+**3.12 JPXML document structure:** The structure of a JPXML element in a JPXML document, which expresses an image data structure. This structure is used for a location path using XPath expression.
+
+**3.13 JPXML element:** An XML element represents a box file format or codestream structure, and is translated from a box, marker, or its content. The 4CC box type, marker type, and the "content" are used as this element name. For more details, see 6.2.
+
+**3.14 location path:** The location of an internal image data using XPath expression with a JPXML document. This expression represents the absolute offset value and the JPXML document structure.
+
+**3.15 marker element:** A JPXML element for the marker segment. This element name is translated from the marker type using the conversion rule described in 7.1 and 7.3.
+
+**3.16 marker segment:** A binary data block in a codestream which contains the marker type and may contain marker properties for coding information.
+
+**3.17 skeleton representation:** A JPXML document which does not contain text nodes. This only represents the structure of a box file format image. For more details, see 6.1.
+
+## 4 Abbreviations and symbols
+
+The abbreviations and symbols defined in Rec. ITU-T T.800 | ISO/IEC 15444-1, Rec. ITU-T T.801 | ISO/IEC 15444-2, Rec. ITU-T T.805 | ISO/IEC 15444-6, Rec. ITU-T T.808 | ISO/IEC 15444-9, Rec. ITU-T T.810 | ISO/IEC 15444-11, and Rec. ITU-T T.812 | ISO/IEC 15444-13 also apply to this Recommendation | International Standard.
+
+## 4.1 Abbreviations
+
+For the purposes of this Recommendation | International Standard, the following abbreviations apply:
+
+|       |                                                        |
+|-------|--------------------------------------------------------|
+| JPXML | Refers to this Recommendation   International Standard |
+| MIME  | Multipurpose Internet Mail Extension                   |
+| TIFF  | Tag Image File Format                                  |
+| XML   | eXtended Metadata Language                             |
+| XSLT  | XML Stylesheet Language Transformation                 |
+
+## 5 Conventions
+
+This Recommendation | International Standard consists of normative and informative text.
+
+Normative text is that text which expresses mandatory requirements. The word "shall" is used to express mandatory requirements strictly to be followed in order to conform to this Specification and from which no deviation is permitted. A conforming implementation is one that fulfils all mandatory requirements.
+
+Informative text is text that is potentially helpful to the user, but not indispensable and can be removed, changed or added editorially without affecting interoperability. All text in this Recommendation | International Standard is normative, with the following exceptions: the Introduction, any parts of the text that are explicitly labelled as "informative", and statements appearing with the preamble "NOTE" and behaviour described using the word "should". The word "should" is used to describe behaviour that is encouraged but is not required for conformance to this Specification.
+
+The keywords "may" and "need not" indicate a course of action that is permissible in a conforming implementation.
+
+The keyword "reserved" indicates a provision that is not specified at this time, shall not be used, and may be specified in the future. The keyword "forbidden" indicates "reserved" and in addition indicates that the provision will never be specified in the future.
+
+## 6 General description
+
+The structural representation for the box-based format and the JPEG 2000 family codestreams is defined in this Recommendation | International Standard, which does not intend to make a new image file format. This image description is described with XML, and this temporary XML document is created as an intermediate image description for accessing internal data robustly and converting an image type. The following subclauses describe more details of this document.
+
+![Figure 1: Example of a JPXML document for a JPEG 2000 image. The diagram shows an XML snippet with various elements and attributes highlighted and labeled. The XML code is: <?xml version='1.0' ?> <xjp:jpxml xjp='http://www.jpeg.org/jpxml/1.0' xjp:name='lena.jp2' ...> <xjp:jP length='12' type='xjp:box' /> ... <xjp:jp2h length='45' type='xjp:box'> <xjp:ihdr length='22' type='xjp:box'> <xjp:width length='4' type='int'>512</xjp:width> <xjp:height length='4' type='int'>512</xjp:height> ... </xjp:ihdr> ... </xjp:jp2h> <xjp:jp2c length='0' href='#xpointer(xjp:jp2c)' /> </xjp:jpxml>. Labels include: Root element (pointing to the root tag), JPXML namespace (pointing to the namespace attribute), JPXML element (pointing to the xjp:jpxml tag), Length attribute for a box content (pointing to length='12'), Type attribute for an element (pointing to type='xjp:box'), Content element (pointing to the inner content of xjp:jp2h), Length attribute for a content content (pointing to length='4'), Length attribute for a box (pointing to length='45'), and Box element (pointing to the xjp:jP tag).](e6df2733626a85205c1db682e6259c46_img.jpg)
+
+Figure 1: Example of a JPXML document for a JPEG 2000 image. The diagram shows an XML snippet with various elements and attributes highlighted and labeled. The XML code is: xml version='1.0' ?   ...   512 512 ...  ...   . Labels include: Root element (pointing to the root tag), JPXML namespace (pointing to the namespace attribute), JPXML element (pointing to the xjp:jpxml tag), Length attribute for a box content (pointing to length='12'), Type attribute for an element (pointing to type='xjp:box'), Content element (pointing to the inner content of xjp:jp2h), Length attribute for a content content (pointing to length='4'), Length attribute for a box (pointing to length='45'), and Box element (pointing to the xjp:jP tag).
+
+Figure 1 – Example of a JPXML document for a JPEG 2000 image
+
+## 6.1 Structure of the JPXML document
+
+The JPXML document is described with three elements; a JPXML element, its attribute, and its content value. The JPXML element structure represents an image structure; box, marker segment, and content structure. This document namespace shall be "http://www.iso.org/jpeg/jpxml/1.0", and this document's root element name shall be 'jpxml'. The JPXML element has two types; the first element is a container element which expresses a box or a marker segment itself, and the second one is a content element which expresses a container's property or a box content. Some containers, such as a superbox, contain other containers, and so a JPXML document will have a tree structure. Each JPXML element shall have 'length' and 'type' attributes, and these attributes denote the byte length and data type of each data chunk, respectively. The content value may be described with text, and its data type denoted with 'type' attribute. Figure 1 is an example of a JPXML document for a JPEG 2000 file format.
+
+The container element name, or the box or marker element name, shall be created with the 4CC box type or the segment marker name, respectively, and the converting rules are described in clause 7. The container element may contain some content elements, which are optional in the JPXML document. There may be only one content element even if a container has several data containers, and this content element type attribute should be a "hexbyte" or "unknown" type. This element name shall be "content" or a name predefined in this Recommendation | International Standard. The attributes in the JPXML elements are used for creating an absolute offset from a location path for indicating chunk data in the image. The detail of this process is described in 7.5.
+
+The box described in Rec. ITU-T T.800 | ISO/IEC 15444-1 and the JPXML document for box format are illustrated in Figure 2. Figures 2 (a), (b) and (c) are illustrations of box format structures; normal box, box with extended length and superbox, and documents (d), (e) and (f) represent the (a), (b) and (c) box structure, respectively. The superbox element shall have whole children box and superbox elements. All box elements with an extended length have a length element for storing the actual box length.
+
+![Figure 2: Examples of box format and JPXML documents. (a) box: A box with length 16, type 'box1', and content. (b) box with extended length: A box with length 1, type 'box1', extended length 24, and content. (c) superbox: A box with length 40, type 'box1', containing two sub-boxes: box2 (length 16, type 'box2') and box3 (length 16, type 'box3'). (d) JPXML document for (a): <box1 length='16' type='box'><content length='8' /></box1>. (e) JPXML document for (b): <box1 length='1' type='box'><length length='8' type='int'>24</length><content length='8' /></box1>. (f) JPXML document for (c): <box1 length='40' type='box'><box2 length='16' type='box' /><box3 length='16' type='box' /></box1>.](5b4e774d63e0e0ed73801a9247755e5f_img.jpg)
+
+(a) box
+
+(b) box with extended length
+
+(c) superbox
+
+(d) JPXML document for (a)
+
+```
+<box1 length="16" type="box">
+  <content length="8" />
+</box1>
+```
+
+(e) JPXML document for (b)
+
+```
+<box1 length="1" type="box">
+  <length length="8" type="int">
+    24</length>
+  <content length="8" />
+</box1>
+```
+
+(f) JPXML document for (c)
+
+```
+<box1 length="40" type="box">
+  <box2 length="16" type="box" />
+  <box3 length="16" type="box" />
+</box1>
+```
+
+Figure 2: Examples of box format and JPXML documents. (a) box: A box with length 16, type 'box1', and content. (b) box with extended length: A box with length 1, type 'box1', extended length 24, and content. (c) superbox: A box with length 40, type 'box1', containing two sub-boxes: box2 (length 16, type 'box2') and box3 (length 16, type 'box3'). (d) JPXML document for (a): . (e) JPXML document for (b): 24. (f) JPXML document for (c): .
+
+**Figure 2 – Examples of box format and JPXML documents**
+
+The JPXML document is generated from an image file format and/or codestreams, and its kind varies from none property to including codestream data representations. When kinds of image property representation are included, the JPXML document is categorized with three levels of representation: "skeleton", "fat-skeleton", and "fat" representations.
+
+The first-level representation, the skeleton representation, shall express only the structure of the image itself, and may contain an attribute for the absolute offset or the location path to the element block. The skeleton shall have no text node in the JPXML elements. This representation is used for a location path that is comparatively robust for changing the box structure of the image and/or marker segment structure of the codestream.
+
+The second-level representation, the fat-skeleton representation, expresses the image structure and some variables of box and/or marker contents. The fat skeleton is an intermediate representation between skeleton and fat representations. Consequently, it also has the skeleton's attribute and the same text node value of JPXML elements, but no binary data (such as a coded codestream). This representation is used for a location path and also some image transformation with XSLT.
+
+The third-and final level representation, the fat representation, expresses the image structure and whole image property values. This whole property may represent a binarized format for use of some applications, such as secure purpose. The binarized contents are translated with MIME's base64 encoding. As this representation requires more data space than the original image data, it is unsuited for use in a storage file format for image data.
+
+## 6.2 Creation of a JPXML document
+
+A JPXML document is created from a box-based format and/or a JPEG 2000 codestream. This generation process may consist of several steps. Figure 3 is an illustration of a block diagram of an image conversion system using the JPXML, and includes forward and inverse JPXML generators. This example consists of a forward JPXML generator, an image edit tool, and an inverse JPXML generator. The processes of forward and inverse JPXML generators may consist of two modules: a JPXML document generator and a location path generator. The JPXML document generator converts between a binary image and an XML document, and the location path generator converts between an absolute offset number to target data and an XPath location path for a target element.
+
+For creating a JPXML document, the forward JPXML document generator uses several rules: the common conversion rule and the three element name rules. The common conversion rule is defined in 7.1. The document element name rules are for a box format, a marker segment, and a tagged image format. The inverse JPXML document generator uses the inverse rules of the forward converter's rules.
+
+The element name rule for the box-based format creates an element name related to the four-character code (4CC) identifying the box container type. Not all 4CC values are allowable for an XML element name, such as an 'xml' and space character, and these 4CC values are modified for an XML element by using the conversion rules defined in 7.2. The details of the box-based format and four-character code are defined in Rec. ITU-T T.800 | ISO/IEC 15444-1, Rec. ITU-T T.801 | ISO/IEC 15444-2, Rec. ITU-T T.802 | ISO/IEC 15444-3, Rec. ITU-T T.805 | ISO/IEC 15444-6, Rec. ITU-T T.807 | ISO/IEC 15444-8, Rec. ITU-T T.808 | ISO/IEC 15444-9, Rec. ITU-T T.833 | ISO/IEC 29199-3 and ISO/IEC 15444-12. The element names are defined in Annex A.
+
+The element name rule for the marker segment creates an element name related to a two-byte code or a marker segment name identifying the marker segment which is defined in Rec. ITU-T T.800 | ISO/IEC 15444-1, Rec. ITU-T T.801 | ISO/IEC 15444-2, Rec. ITU-T T.807 | ISO/IEC 15444-8, Rec. ITU-T T.809 | ISO/IEC 15444-10, and Rec. ITU-T T.810 | ISO/IEC 15444-11. The two-byte code, non-character and invisible value, is converted to a visible code value for use as an XML element name by using conversion rules defined in 7.3. The details of these element names are defined in Annex B.
+
+The element name rule for the tagged image format creates an element name related to the two byte code of the tag value identifying the tagged maker property which is defined in ISO 12639 and Rec. ITU-T T.832 | ISO/IEC 29199-2. The two byte code, non-character and invisible value, used in the TIFF image and JPEG XR, is converted to a visible code value for use as an XML element name by using conversion rules defined in 7.4.
+
+![Figure 3 – Block diagram of image converting with JPXML. The diagram shows a workflow starting from a 'Colour image' (Binary JPEG 2000) on the left. It passes through 'Image to XML rep.' (resulting in XML w/ absolute offset), then 'Absolute offset to relative ref.' (resulting in XML w/ location address), then 'Edit convert etc...' (maintaining XML w/ location address), then 'Relative ref. to absolute offset' (returning to XML w/ absolute offset), and finally 'XML rep. to image' (Binary JPEG 2000) resulting in a 'Grayscale small image' on the right. A top block 'JPXML convert rules' provides input to the conversion steps. The blocks are connected by arrows indicating the flow of data and control.](042733dc5e8e7f5f30b60adba3266cde_img.jpg)
+
+Figure 3 – Block diagram of image converting with JPXML. The diagram shows a workflow starting from a 'Colour image' (Binary JPEG 2000) on the left. It passes through 'Image to XML rep.' (resulting in XML w/ absolute offset), then 'Absolute offset to relative ref.' (resulting in XML w/ location address), then 'Edit convert etc...' (maintaining XML w/ location address), then 'Relative ref. to absolute offset' (returning to XML w/ absolute offset), and finally 'XML rep. to image' (Binary JPEG 2000) resulting in a 'Grayscale small image' on the right. A top block 'JPXML convert rules' provides input to the conversion steps. The blocks are connected by arrows indicating the flow of data and control.
+
+**Figure 3 – Block diagram of image converting with JPXML**
+
+![Figure 4 – Example of the process for converting between the XML location path and offset. The diagram shows an input XML document with location address (XML Rep.) entering an 'Add offset attribute' block. This produces an XML doc w/ absolute offset. This document, along with an XPath expression '//boxtype/', enters an 'XPath engine'. The engine retrieves an XML element with absolute offset: <boxtype offset='XX' />. This is passed to an 'Extract absolute offset' block, which outputs the final 'offset: XX' as an absolute offset.](1439cb942d9e363bbb3161b5540dd8c6_img.jpg)
+
+Figure 4 – Example of the process for converting between the XML location path and offset. The diagram shows an input XML document with location address (XML Rep.) entering an 'Add offset attribute' block. This produces an XML doc w/ absolute offset. This document, along with an XPath expression '//boxtype/', enters an 'XPath engine'. The engine retrieves an XML element with absolute offset: . This is passed to an 'Extract absolute offset' block, which outputs the final 'offset: XX' as an absolute offset.
+
+**Figure 4 – Example of the process for converting between the XML location path and offset**
+
+## 6.3 Access with the JPXML document
+
+The two location representations, an XML location path and an absolute offset, are used to access internal image data with the JPXML document. The XML location path homologizes the target image data to identify the target element in the JPXML document. The absolute offset corresponding to the target element identified by the location path is used for locating the data chunk of the image, and this value shall be used for a binary data access. For converting between the text location and the offset value, conversion rules defined in 8.1 are used.
+
+An absolute offset can be generated from the target location path in several ways. One example of generating a target offset process consists of three steps: 1) set each element's data chunk offset to its element offset attribute, 2) identify a target element from a target location path by using XML tools, and 3) extract the target element offset attribute value as an absolute offset. Figure 4 depicts an example of this process. After this process, the generated absolute offset is the location of the target data chunk from the very start of an image.
+
+A target location path can be generated from a target absolute offset by following three steps: 1) set each element's data chunk offset to its element offset attribute, 2) identify a target element by comparing the element's offset attribute and the target offset, and 3) create a location path from the selected target element. This process creates the location path which identifies the target absolute offset, and this text representation will not suffer from binary data changes in the image.
+
+These processes have the same offset generator for the JPXML document, and these generators use conversion rules defined in 8.1. Figure 5 is an example of a JPXML document with offset calculated by this generator. As shown in this example, the "box2" box offset is eight bytes because each box has eight bytes of data space for the box length and type of storage, and the "box2" is the first child of "box1" box. By using this generated JPXML document, all image data chunks described by the JPXML elements can be accessed by the XML location path.
+
+![Figure 5(a) – An example of part of a pseudo box-based format structure. The diagram shows a horizontal sequence of data fields. It starts with 'length 27' and 'type ](63e0c22852c26699d0bd095a2d796bab_img.jpg)
+
+Figure 5(a) – An example of part of a pseudo box-based format structure. The diagram shows a horizontal sequence of data fields. It starts with 'length 27' and 'type
+
+**(a) An example of part of a pseudo box-based format structure**
+
+```
+
+<box1 length="39" type="box" offset="0">
+  <box2 length="11" type="box" offset="8">
+    <content length="3" type="int" offset="16" />
+  </box2>
+  <box3 length="20" type="box" offset="19">
+    <param1 length="4" type="int" offset="27" />
+    <param2 length="2" type="short" offset="31" />
+    <param3 length="2" type="short" offset="33" />
+    <param4 length="4" type="int" offset="35" />
+  </box3>
+</box1>
+
+```
+
+**(b) Part of a pseudo JPXML document with an offset attribute for the (a) format**
+
+```
+
+<box3 length="16" type="box" offset="19">
+  <content length="12" type="hexBinary" offset="27" />
+</box3>
+
+```
+
+**(c) Another representation of the box3 element in the (b) document (single-content representation)****Figure 5 – Example of JPXML document accessing**
+
+## 7 Document creation rules
+
+The conversion rules between the JPXML document and the image consist of three parts: the first part is a common conversion rule for file formats and codestreams, the second part is a conversion rule between 4CC and XML element names, and the third part is a conversion rule between marker segment names and XML element names.
+
+### 7.1 Common rule
+
+All JPXML forward converters shall use the following common forward rules for JPXML conversion. The boxes within a superbox shall be represented in JPXML form when these rules are used for a file format forward conversion. An *'offset'* attribute value shall be converted to a location path by using a JPXML document structure.
+
+- 1) The namespace of the JPXML document shall be "http://www.iso.org/jpeg/jpxml/1.0".
+- 2) The *'jpxml'* shall be used for the JPXML root element, representing one file format or codestream.
+- 3) The root element may have a *'name'* attribute for identifying an image name.
+- 4) All elements shall have *'length'* and *'type'* attributes, representing data byte length and type respectively.
+- 5) The *'type'* attributes value for the box or marker element shall be 'box' or 'marker' respectively.
+- 6) A box element with *length=1* attribute shall have a length element, representing the data length in byte.
+- 7) All element may have an *'offset'* attribute, representing the absolute offset to the data chunk in byte.
+- 8) The box element shall have several box elements when the original box has a box inside its content.
+- 9) The element of a box or marker segment may have content elements for representing its properties.
+- 10) The predefined element names defined in later annexes shall be used for element names.
+- 11) The box or marker parameters may be represented in XML form, defined in later annexes, and stored in the JPXML box or marker element.
+- 12) The box or marker parameters may be represented as base64 binary, and stored in the box or marker element.
+
+All JPXML inverse converters shall use the following common inverse rules for JPXML conversion. A box element having one or more box elements shall be converted to a superbox when reconstructing a file format. If an *'offset'* attribute value is the location path using a JPXML document structure, this location path shall be converted to an absolute offset value, and stored in its element attribute.
+
+- 1) The JPXML document shall have namespace of "http://www.iso.org/jpeg/jpxml/1.0".
+- 2) The *'jpxml'* root element shall be converted to one file format or codestream.
+- 3) The *'name'* attribute value in the root element shall be used for a file name.
+- 4) The *'length'* and *'type'* attribute values shall be used for converted data length and type respectively.
+- 5) The element having 'box' or 'marker' type shall be converted to a box or marker segment respectively.
+
+- 6) The node value of the length element in the box element with `length=1` attribute shall be used for its converted data chunk length.
+- 7) The `'offset'` attribute value may be used for its converted data chunk location in the image.
+- 8) All box elements in the box shall be converted into the box content.
+- 9) All child elements in a box or marker element shall be converted into internal contents of the data chunk.
+- 10) All content element shall be combined to a binary data of the parent element.
+- 11) The JPXML content elements defined in later annexes shall be converted to binary data and stored in one of the parent contents of the box or maker.
+- 12) The JPXML content in base64 binary shall be converted to a binary data with the base64 converter and stored in one of the parent contents of the box or maker.
+
+**Table 1 – Example of 4CC box type conversions**
+
+| Box name                | Box type                | Hex decimal | JPXML element name |
+|-------------------------|-------------------------|-------------|--------------------|
+| JPEG 2000 Signature box | <code>jp\040\040</code> | 0x6A50 2020 | <code>jp__</code>  |
+| JP2 Header box          | <code>jp2h</code>       | 0x6A70 3268 | <code>jp2h</code>  |
+| Resolution box          | <code>url\040</code>    | 0x7572 6C20 | <code>url_</code>  |
+| URL box                 | <code>res\040</code>    | 0x7265 7320 | <code>res_</code>  |
+| XML box                 | <code>xml\040</code>    | 0x786D 6C20 | <code>_xml_</code> |
+
+## 7.2 Element name rule for box format
+
+The JPXML forward converter for file formats translates a box-based format to a JPXML document, and shall use the following forward conversion rule for the 4CC:
+
+- 1) The JPXML element name shall use a 4CC box type.
+- 2) The alphanumeric characters in 4CC box type shall be directly used for the element name.
+- 3) The space, `'\040'` code, shall be represented with a `'_'` character for the JPXML element name.
+- 4) The code `'.HH'` (H: hexadecimal character = 0, ..., 9, A, ..., F) shall be used for any other characters.
+- 5) The `'_'` character at the first character of the element name shall be the escape character.
+
+The JPXML inverse converter to file formats translates a JPXML document to a box-based format, and shall use the following inverse conversion rule for the 4CC.
+
+- 1) The JPXML element name shall be converted to a 4CC box type, and creates its type box.
+- 2) The `'_'` character at the first character of the element name may not be removed from the 4CC box type.
+- 3) The alphanumeric name shall be directly used for the 4CC box type.
+- 4) The `'_'` character in the element name space shall be represented with a `'\040'` code for the 4CC.
+- 5) The `'.HH'` string in the name shall be converted to a `'0xHH'` code character.
+
+### 7.3 Element name rule for a tagged image format
+
+The JPXML forward converter for tagged image file formats, translates a tag value in a directory entry to a JPXML document element name and shall use the following forward conversion rule.
+
+- 1) The two bytes tag value shall be represented as the four characters hex string notation, `'HHHH'` (H: hexadecimal character = 0, ..., 9, A, ..., F).
+- 2) The `'_'` character shall be placed at the front of the four character string, and creates a five characters string (`'_HHHH'`).
+
+The JPXML inverse converter to tagged image file formats translates a JPXML document name to a tag value in a directory entry, and shall use the following inverse conversion rule for the 4CC.
+
+- 1) The first `'_'` character shall be removed from the five-character string, and shall create a four-character string.
+- 2) The four character-string, `'HHHH'` shall be converted to a `'0xHHHH'` code value
+
+### 7.4 Element name rule for a marker segment
+
+The JPXML forward converter for marker segments translates JPEG 2000 marker segments to a JPXML document, and shall use the following forward conversion rule.
+
+- 1) The marker symbol name shall be used for a JPXML codestream element name, or the forward conversion rule for a tagged image file format shall be used for converting the marker symbol code to an element name.
+
+The JPXML inverse converter to marker segments translates a JPXML document to JPEG 2000 marker segments, and shall use the following inverse conversion rule.
+
+- 1) All elements named with its marker symbol name shall be converted to its named marker symbol code.
+- 2) All elements with a name starting with a '\_' character of the five-character string shall be converted to the marker symbol code by using the inverse conversion rule for the tagged image file format.
+
+**Table 2 – Example of codestream marker conversions**
+
+| Codestream marker name | Symbol name | Code   | JPXML element name |
+|------------------------|-------------|--------|--------------------|
+| Start of codestream    | SOC         | 0xFF4F | SOC                |
+| Start of tile-part     | SOT         | 0xFF90 | SOT                |
+| Start of data          | SOD         | 0xFF93 | SOD                |
+| End of codestream      | EOC         | 0xFFD9 | EOC                |
+| Start of packet        | SOP         | 0xFF91 | SOP                |
+
+## 7.5 Element type attributes
+
+All elements have a type attribute which identifies the data type of the element content data. This Recommendation | International Standard defines uses of six data types: box, marker, fourcc, location, hexbyte, and integer and time. The integer and time data types are used for the element content data type as integer and time types, respectively, and these data types are defined in the XML schema Part 2 Recommendation. The box and marker data types are used to identify the box element and the marker element, respectively. The fourcc data type indicates the element content data that shall be the 4CC data type, and the 4CC value will not converted with the rules previously described. The location indicates that the elements can have any location type value. The hexbyte indicates that the element data may be represented as a hexadecimal value in big-endian order. The XML definitions for the box, marker, fourcc, location and hexbyte data types can be defined by the following XML schema's simple type data type definitions:
+
+```
+
+<xs:simpleType name="box">
+  <xs:restriction base="xs:string" />
+</xs:simpleType>
+
+<xs:simpleType name="marker">
+  <xs:restriction base="xs:string" />
+</xs:simpleType>
+
+<xs:simpleType name="fourcc">
+  <xs:restriction base="xs:string">
+    <xs:pattern value="[ a-zA-Z0-9_]{4}" />
+  </xs:restriction>
+</xs:simpleType>
+
+<xs:simpleType name="location">
+  <xs:restriction base="xs:anyURL" />
+</xs:simpleType>
+
+<xs:simpleType name="hexbyte">
+  <xs:restriction base="xs:string">
+    <xs:pattern value="([a-f0-9][a-f0-9])+" />
+  </xs:restriction>
+</xs:simpleType>
+
+```
+
+## 8 Accessing image data
+
+The XML location path and the JPXML document can be used to access internal binary chunk data in the image data. The following three steps access the internal binary data: the first step identifies the target element by using the location path and the JPXML document, the second step converts the target element to an absolute offset, and the third and final step accesses the internal image data with the target absolute offset position. To achieve the second step, the following rules are employed.
+
+## 8.1 Rules for location conversion
+
+The following conversion rules are for calculating an absolute offset of the target chunk from the location path point to the target element, which corresponds to the offset. To comply with these rules, there may be two approaches for calculation of the target absolute offset value; the target to root approach and the root to target approach.
+
+- 1) The absolute offset shall be the sum of length attribute values between the top and the target elements, except for the following elements.
+- 2) For the superbox child elements, the value 8 shall be used for offset counting instead of the superbox length attribute value.
+- 3) The length of the child boxes contained in the parent box, ending at the beginning of the target box, will not be used for offset counting, and the length of the parent box is used for counting.
+
+Figures 6 and 7 are illustrations of two examples of an algorithm for calculating the absolute offset value from the target element using these rules. In these algorithms, the root element shall not be used as target element, because the root element is not part of the image data. The first algorithm calculates all element nodes from the target to the root elements, and the second algorithm calculates all element nodes from the first child of the root to the target elements.
+
+![Flowchart illustrating an algorithm for calculating an offset value from the target element.](cb4cfa42ce34febde7bdb882f3fc3094_img.jpg)
+
+```
+
+graph TD
+    Start([Calculate offset from the element node location  
+The initial element is the target element.]) --> Init[offset = 0]
+    Init --> Join(( ))
+    Join --> Decision1{No previous  
+sibling node?}
+    Decision1 -- No --> MovePrev[Move to previous  
+sibling node]
+    MovePrev --> AddLength[offset = offset + length]
+    AddLength --> Join
+    Decision1 -- Yes --> Decision2{Is parent  
+root node?}
+    Decision2 -- Yes --> End([End])
+    Decision2 -- No --> MoveParent[Move to parent node]
+    MoveParent --> Add8[offset = offset + 8]
+    Add8 --> Join
+
+```
+
+The flowchart starts with an oval containing the text "Calculate offset from the element node location" and "The initial element is the target element." This leads to a rectangle "offset = 0". A join point then leads to a decision diamond "No previous sibling node?". If the answer is "No", the flow goes to a rectangle "Move to previous sibling node", then to "offset = offset + length", and loops back to the join point. If the answer is "Yes", it goes to another decision diamond "Is parent root node?". If "Yes", it leads to an oval "End". If "No", it goes to a rectangle "Move to parent node", then to "offset = offset + 8", and loops back to the join point.
+
+Flowchart illustrating an algorithm for calculating an offset value from the target element.
+
+**Figure 6 – Example 1 of an algorithm for calculating an offset value from the target element**
+
+![Flowchart for calculating an offset value from the target element. The process starts with 'Calculate offset from the element node location' and 'The initial element is the first child of root element.' It then sets 'offset = 0'. A loop begins with 'Is target node?'. If 'Yes', it goes to 'End'. If 'No', it checks 'Has child?'. If 'Yes', it increments 'offset = offset + 8' and 'Move to child node'. If 'No', it increments 'offset = offset + length'. Then it checks 'Has next sibling node?'. If 'Yes', it 'Move to next sibling node'. If 'No', it 'Move to parent node'. Both 'Move to child node' and 'Move to next sibling node' lead back to the 'Is target node?' decision. 'Move to parent node' leads to the 'Has next sibling node?' decision.](c85ded401105f62f2d6ff26b3b5eb4af_img.jpg)
+
+```
+
+graph TD
+    Start([Calculate offset from the element node location  
+The initial element is the first child of root element.]) --> Init[offset = 0]
+    Init --> IsTarget{Is target node?}
+    IsTarget -- Yes --> End([End])
+    IsTarget -- No --> HasChild{Has child?}
+    HasChild -- Yes --> Offset8[offset = offset + 8]
+    Offset8 --> MoveChild[Move to child node]
+    MoveChild --> IsTarget
+    HasChild -- No --> OffsetLength[offset = offset + length]
+    OffsetLength --> HasNextSibling{Has next sibling node?}
+    HasNextSibling -- Yes --> MoveNextSibling[Move to next sibling node]
+    MoveNextSibling --> IsTarget
+    HasNextSibling -- No --> MoveParent[Move to parent node]
+    MoveParent --> HasNextSibling
+
+```
+
+Flowchart for calculating an offset value from the target element. The process starts with 'Calculate offset from the element node location' and 'The initial element is the first child of root element.' It then sets 'offset = 0'. A loop begins with 'Is target node?'. If 'Yes', it goes to 'End'. If 'No', it checks 'Has child?'. If 'Yes', it increments 'offset = offset + 8' and 'Move to child node'. If 'No', it increments 'offset = offset + length'. Then it checks 'Has next sibling node?'. If 'Yes', it 'Move to next sibling node'. If 'No', it 'Move to parent node'. Both 'Move to child node' and 'Move to next sibling node' lead back to the 'Is target node?' decision. 'Move to parent node' leads to the 'Has next sibling node?' decision.
+
+Figure 7 – Example 2 of an algorithm for calculating an offset value from the target element
+
+### 8.2 Example of location conversion
+
+Figure 8 shows an example of offset calculations for a pseudo JPXML document. The third and fourth columns, labelled "offset 1" and "offset 2", are the result of the target to root approach and the root to target approach, respectively. Their values are calculated by the algorithms depicted in Figures 6 and 7, respectively. In this figure, the offset 1,  $a+b+d+8$ , for the "BoxH" box is not the same as the offset 2,  $a+b+f+g+24$ . However, the "BoxD" box length,  $d$ , is the same as the summation of its content and header lengths,  $f+g+16$ , and so these offsets have identical value.
+
+| Line | Pseudo JPXM document                 | offset 1     | offset 2           |
+|------|--------------------------------------|--------------|--------------------|
+| 1    | <jpxml ... >                         |              |                    |
+| 2    | <BoxA length="a" type="box" />       | 0            | 0                  |
+| 3    | <BoxB length="b" type="box" />       | a            | a                  |
+| 4    | <BoxC length="c" type="box">         | a+b          | a+b                |
+| 5    | <BoxD length="d" type="box">         | a+b+8        | a+b+8              |
+| 6    | <BoxE length="e" type="box">         | a+b+16       | a+b+16             |
+| 7    | <BoxF length="f" type="box" />       | a+b+24       | a+b+24             |
+| 8    | <BoxG length="g" type="box" />       | a+b+f+24     | a+b+f+24           |
+| 9    | </BoxE>                              |              |                    |
+| 10   | </BoxD>                              |              |                    |
+| 11   | <BoxH length="h" type="box" />       | a+b+d+8      | a+b+f+g+24         |
+| 12   | </BoxC>                              |              |                    |
+| 13   | <BoxI length="i" type="box" />       | a+b+c        | a+b+f+g+h+24       |
+| 14   | <BoxJ length="j" type="box">         | a+b+c+i      | a+b+f+g+h+i+24     |
+| 15   | <BoxK length="k" type="box" />       | a+b+c+i+8    | a+b+f+g+h+i+32     |
+| 16   | <BoxL length="l" type="box">         | a+b+c+i+k+8  | a+b+f+g+h+i+k+32   |
+| 17   | <length length="8" type="integer" /> | a+b+c+i+k+16 | a+b+f+g+h+i+k+40   |
+| 18   | <BoxM length="m" type="box" />       | a+b+c+i+k+24 | a+b+f+g+h+i+k+48   |
+| 19   | </BoxL>                              |              |                    |
+| 20   | </BoxJ>                              |              |                    |
+| 21   | </BoxN length="n" type="box" />      | a+b+c+j      | a+b+f+g+h+i+k+m+48 |
+| 22   | </jpxml>                             |              |                    |
+
+Figure 8 – Example of offsets generated for a pseudo JPXML document
+
+# **Annex A**
+
+## **JPXML elements for box file format**
+
+(This annex forms an integral part of this Recommendation | International Standard.)
+
+### **A.1 Introduction**
+
+This annex provides the content element name definitions, and length and type attributes for JPEG 2000 family formats. The box element appearance and structure shall be in conformity with Rec. ITU-T T.800 | ISO/IEC 15444-1, Rec. ITU-T T.801 | ISO/IEC 15444-2, Rec. ITU-T T.802 | ISO/IEC 15444-3, Rec. ITU-T T.805 | ISO/IEC 15444-6, Rec. ITU-T T.807 | ISO/IEC 15444-8, Rec. ITU-T T.808 | ISO/IEC 15444-9 and ISO/IEC 15444-12.
+
+### **A.2 Box element definitions**
+
+This subclause includes many tables of the box content element definitions, and these tables define the content element name, the content data length in bytes, and the content data type. The JPXML data types are described in 7.5. Some tables define the sub-content element names of a defined content element, and some box or content elements have content element definitions of two or more types. For more detailed information of the meaning and structure of box content, refer to Recommendations | International Standards listed in A.1.
+
+#### **A.2.1 Still picture format definitions**
+
+The box file formats defined in Rec. ITU-T T.800 | ISO/IEC 15444-1 and Rec. ITU-T T.801 | ISO/IEC 15444-2 are designed to represent a still picture image. Table A.1 illustrates element structures of these file formats. These content element names and types are defined in the following tables.
+
+**Table A.1 – Box element structure for a still image**
+
+| Element name      | Box name                                       | Part 1   | Part 2   | Defined  |
+|-------------------|------------------------------------------------|----------|----------|----------|
+| <code>jp__</code> | <i>JPEG family signature box</i>               | required | required | 1        |
+| <code>ftyp</code> | <i>File type and compatibility box</i>         | required | required | 1        |
+| <code>rreq</code> | <i>Reader requirement box</i>                  |          | required | 2        |
+| <code>jp2h</code> | <i>JP2 header box (superbox)</i>               | required | optional | 1, 2     |
+| <code>lbl_</code> | <i>Label box</i>                               |          | optional | 2        |
+| <code>ihdr</code> | <i>Image header box</i>                        | required | required | 1, 2, 6  |
+| <code>bpcc</code> | <i>Bits per component box</i>                  | optional | optional | 1, 2     |
+| <code>colr</code> | <i>Colour specification box</i>                | required | required | 1, 2, 6  |
+| <code>pclr</code> | <i>Palette box</i>                             | optional | optional | 1        |
+| <code>cmap</code> | <i>Component mapping box</i>                   | optional | optional | 1        |
+| <code>cdef</code> | <i>Channel description box</i>                 | optional | optional | 1        |
+| <code>res_</code> | <i>Resolution box (superbox)</i>               | optional | optional | 1        |
+| <code>resc</code> | <i>Capture resolution box</i>                  | optional | optional | 1        |
+| <code>resd</code> | <i>Display resolution box</i>                  | optional | optional | 1        |
+| <code>jpch</code> | <i>Codestream header box (superbox)</i>        |          | optional | 2        |
+| <code>lbl_</code> | <i>Label box</i>                               |          | optional | 2        |
+| <code>ihdr</code> | <i>Image header box</i>                        |          | required | 1, 2, 6  |
+| <code>bpcc</code> | <i>Bits per component box</i>                  |          | optional | 2        |
+| <code>pclr</code> | <i>Palette box</i>                             |          | optional | 1        |
+| <code>cmap</code> | <i>Component mapping box</i>                   |          | optional | 1        |
+| <code>jplh</code> | <i>Compositing layer header box (superbox)</i> |          | optional | 2        |
+| <code>lbl_</code> | <i>Label box</i>                               |          | optional | 2        |
+| <code>cgrp</code> | <i>Colour group box (superbox)</i>             |          | optional | 2        |
+| <code>colr</code> | <i>Colour specification box</i>                |          | optional | 1, 2, 6  |
+| <code>opct</code> | <i>Opacity box (superbox)</i>                  |          | optional | 1, 2     |
+| <code>cdef</code> | <i>Channel description box</i>                 |          | optional | 1        |
+| <code>creg</code> | <i>Codestream registration box</i>             |          | optional | 2        |
+| <code>pxfm</code> | <i>Pixel format box</i>                        |          | optional | 2        |
+| <code>res_</code> | <i>Resolution box (superbox)</i>               |          | optional | 1        |
+| <code>dtbl</code> | <i>Data reference box</i>                      |          | optional | 2, 6, 12 |
+| <code>ftbl</code> | <i>Fragment table box (superbox)</i>           |          | optional | 2, 6     |
+
+**Table A.1 – Box element structure for a still image**
+
+| Element name | Box name                                      | Part 1   | Part 2   | Defined  |
+|--------------|-----------------------------------------------|----------|----------|----------|
+| flst         | <i>Fragment list box</i>                      |          | optional | 2, 6     |
+| jp2c         | <i>Contiguous codestream box</i>              | required | optional | 1, 2, 6  |
+| mdat         | <i>Metadata box</i>                           |          | optional | 2        |
+| comp         | <i>Composition box</i>                        |          | optional | 2        |
+| copt         | <i>Composition options box</i>                |          | optional | 2        |
+| inst         | <i>Instruction set box</i>                    |          | optional | 2        |
+| drep         | <i>Desired reproductions box (superbox)</i>   |          | optional | 2        |
+| gtso         | <i>Graphics technical standard output box</i> |          | optional | 2        |
+| roid         | <i>ROI description box</i>                    |          | optional | 2        |
+| cref         | <i>Cross reference box (superbox)</i>         |          | optional | 2, 6     |
+| flst         | <i>Fragment list box</i>                      |          | optional | 2, 6     |
+| asoc         | <i>Association box (superbox)</i>             |          | optional | 2        |
+| dxml         | <i>Decomposed XML box</i>                     |          | optional | 2        |
+| nlst         | <i>Number list box</i>                        |          | optional | 2        |
+| lbl_         | <i>Label box</i>                              |          | optional | 2        |
+| bfil         | <i>Binary filter box</i>                      |          | optional | 2        |
+| chck         | <i>Digital signature box</i>                  |          | optional | 2        |
+| mp7b         | <i>MPEG-7 binary box</i>                      |          | optional | 2        |
+| free         | <i>Free space box</i>                         |          | optional | 2        |
+| xml_         | <i>XML container box</i>                      | optional | optional | 1, 2, 12 |
+| jp2i         | <i>IPR box</i>                                | optional | optional | 1        |
+| uuid         | <i>UUID box</i>                               | optional | optional | 1        |
+| uinf         | <i>UUID information box (superbox)</i>        | optional | optional | 1        |
+| ulst         | <i>UUID list box</i>                          | optional | optional | 1        |
+| url_         | <i>Data entry box</i>                         | optional | optional | 1        |
+| jclx         | <i>Compositing layer extensions box</i>       |          | optional | 2        |
+| jlxi         | <i>Compositing layer extensions info box</i>  |          | optional | 2        |
+| j2cx         | <i>Multiple codestream box</i>                |          | optional | 2        |
+| j2ci         | <i>Multiple codestream info box</i>           |          | optional | 2        |
+| grp_         | <i>Grouping box</i>                           |          | optional | 2        |
+
+##### **A.2.1.1 Box element definitions for JPEG 2000 Part 1 format**
+
+**Table A.2 – Content element name for jp\_\_**
+
+| content   | length | type    | loop |
+|-----------|--------|---------|------|
+| signature | 12     | hexbyte |      |
+
+**Table A.3 – Content element name for ftyp**
+
+| content       | length | type    | loop |
+|---------------|--------|---------|------|
+| brand         | 4      | fourcc  |      |
+| version       | 4      | integer |      |
+| compatibility | 4      | fourcc  | ┘    |
+
+**Table A.4 – Content element name for jp2h**
+
+| content | length   | type | loop |
+|---------|----------|------|------|
+| ihdr    | –        | box  | =1   |
+| bpcc    | optional | box  | ≤1   |
+| colr    | –        | box  | ≥1   |
+| pclr    | optional | box  | ≥0   |
+| cmap    | optional | box  | ≤1   |
+| cdef    | –        | box  | ≤1   |
+| res_    | –        | box  | ≤1   |
+
+**Table A.5 – Content element name for ihdr**
+
+| content        | length | type    | loop |
+|----------------|--------|---------|------|
+| height         | 4      | integer |      |
+| width          | 4      | integer |      |
+| num_components | 2      | integer |      |
+| depth          | 1      | integer |      |
+| compression    | 1      | integer |      |
+| colour_unknown | 1      | integer |      |
+| ipr            | 1      | integer |      |
+
+**Table A.6 – Content element name for colr**
+
+| Content    | length | type    | loop |
+|------------|--------|---------|------|
+| method     | 1      | integer |      |
+| precedence | 1      | integer |      |
+| approx     | 1      | integer |      |
+| colour     | ≥4     | hexbyte |      |
+
+**Table A.7 – Content element name for bpcc**
+
+| content | length | type    | loop |
+|---------|--------|---------|------|
+| depth   | 1      | integer | ]    |
+
+**Table A.8 – Content element name for pclr**
+
+| content        | length      | type    | loop |
+|----------------|-------------|---------|------|
+| num_entries    | 2           | integer |      |
+| num_components | 1           | integer |      |
+| depth          | 1           | integer | ]    |
+| data           | num_entries | hexbyte | ]    |
+
+**Table A.9 – Content element name for cdef**
+
+| content     | length | type    | loop |
+|-------------|--------|---------|------|
+| num_entries | 2      | integer |      |
+| index       | 2      | integer | ]    |
+| type        | 2      | integer |      |
+| assoc       | 2      | hexbyte |      |
+
+**Table A.10 – Content element name for res\_**
+
+| content | length | type | loop |
+|---------|--------|------|------|
+| resc    | –      | box  | ≤1   |
+| resd    | –      | box  | ≤1   |
+
+**Table A.11 – Content element name for resc and resd**
+
+| content  | length | type    | loop |
+|----------|--------|---------|------|
+| vert_num | 2      | integer |      |
+| vert_den | 2      | integer |      |
+| hori_num | 2      | integer |      |
+| hori_den | 2      | integer |      |
+| vert_exp | 2      | integer |      |
+| hori_exp | 2      | integer |      |
+
+##### **A.2.1.2 Box element definitions for JPEG 2000 part 2 format**
+
+**Table A.18 – Content element name for rreq**
+
+| content             | length | type    | loop |
+|---------------------|--------|---------|------|
+| length              | 1      | integer |      |
+| fua_mask            | length | hexbyte |      |
+| dc_mask             | length | hexbyte |      |
+| num_std_flags       | 2      | integer |      |
+| std_flag            | 2      | integer | ]    |
+| std_mask            | length | hexbyte |      |
+| num_vender_features | 2      | integer |      |
+| vender_feature      | 16     | integer | ]    |
+| vender_mask         | length | hexbyte |      |
+
+**Table A.19 – Content element name for dtbl**
+
+| content     | length   | type     | loop |
+|-------------|----------|----------|------|
+| num_entries | 2        | integer  |      |
+| location    | variable | location |      |
+
+**Table A.12 – Content element name for uuid**
+
+| content | length   | type    | loop |
+|---------|----------|---------|------|
+| id      | 16       | integer |      |
+| data    | 0-65,531 | hexbyte |      |
+
+**Table A.13 – Content element name for uinf**
+
+| content | length | type | loop |
+|---------|--------|------|------|
+| ulst    | –      | box  | =1   |
+| url_    | –      | box  | =1   |
+
+**Table A.14 – Content element name for ulst**
+
+| content     | length | type    | loop |
+|-------------|--------|---------|------|
+| num_entries | 2      | integer |      |
+| data        | 16     | hexbyte | ]    |
+
+**Table A.15 – Content element name for url\_**
+
+| content  | length   | type     | loop |
+|----------|----------|----------|------|
+| location | 0-65,531 | location |      |
+
+**Table A.16 – Content element name for \_xml\_**
+
+| content | length   | type   | loop |
+|---------|----------|--------|------|
+| text    | 0-65,531 | string |      |
+
+**Table A.17 – Content element name for jp2c**
+
+| content | length | type    | loop |
+|---------|--------|---------|------|
+| data    | ≥0     | hexbyte |      |
+
+**Table A.20 – Content element name for lbl\_**
+
+| content | length   | type   | loop |
+|---------|----------|--------|------|
+| label   | variable | string |      |
+
+**Table A.21 – Content element name for mp7b**
+
+| content | length   | type    | loop |
+|---------|----------|---------|------|
+| mpeg7   | variable | hexbyte |      |
+
+**Table A.22 – Content element name for ftbl**
+
+| content | length | type | loop |
+|---------|--------|------|------|
+| flst    | –      | box  | ≥0   |
+
+**Table A.23 – Content element name for free**
+
+| content | length   | type    | loop |
+|---------|----------|---------|------|
+| data    | 0-65,531 | hexbyte |      |
+
+**Table A.24 – Content element name for flst**
+
+| content        | length | type    | loop |
+|----------------|--------|---------|------|
+| num_entries    | 2      | integer |      |
+| offset         | 8      | integer | ]    |
+| length         | 4      | integer |      |
+| data_reference | 2      | integer |      |
+
+**Table A.25 – Content element name for cref**
+
+| content | length | type    | loop |
+|---------|--------|---------|------|
+| type    | 4      | integer | =1   |
+| flst    | –      | box     | =1   |
+
+**Table A.26 – Content element name for jpch**
+
+| content | length | type | loop |
+|---------|--------|------|------|
+| lbl_    | –      | box  | ≥0   |
+| ihdr    | –      | box  |      |
+| bpcc    | –      | box  |      |
+| pclr    | –      | box  |      |
+| cmap    | –      | box  |      |
+| roid    | –      | box  |      |
+
+**Table A.27 – Content element name for jplh**
+
+| content | length | type | loop |
+|---------|--------|------|------|
+| lbl_    | –      | box  | ≥0   |
+| cgrp    | –      | box  | ≥0   |
+| opct    | –      | box  | ≥0   |
+| cdef    | –      | box  | ≥0   |
+| creq    | –      | box  | ≥0   |
+| res_    | –      | box  | ≤1   |
+
+**Table A.28 – Content element name for cgrp**
+
+| content | length   | type | loop |
+|---------|----------|------|------|
+| colr    | 0-65,531 | box  | ≥1   |
+
+**Table A.29 – Content element name for colour**
+
+| colour      | length   | type    | loop |
+|-------------|----------|---------|------|
+| enum_colour | 4        | integer |      |
+| enum_param  | variable | hexbyte |      |
+
+  
+
+| colour        | length   | type    | loop |
+|---------------|----------|---------|------|
+| vender_colour | 16       | integer |      |
+| vender_param  | variable | hexbyte |      |
+
+**Table A.30 – Content element name for enum\_param**
+
+| enum_param | length | type    | loop |
+|------------|--------|---------|------|
+| range_L    | 4      | integer |      |
+| offset_L   | 4      | integer |      |
+| range_a    | 4      | integer |      |
+| offset_a   | 4      | integer |      |
+| range_b    | 4      | integer |      |
+| offset_b   | 4      | integer |      |
+| illuminant | 4      | integer |      |
+
+| enum_param | length | type    | loop |
+|------------|--------|---------|------|
+| range_J    | 4      | integer |      |
+| offset_J   | 4      | integer |      |
+| range_a    | 4      | integer |      |
+| offset_a   | 4      | integer |      |
+| range_b    | 4      | integer |      |
+| offset_b   | 4      | integer |      |
+
+**Table A.31 – Content element name for opct**
+
+| content     | length | type    | loop |
+|-------------|--------|---------|------|
+| type        | 1      | integer |      |
+| num_entries | 1      | integer |      |
+| data        | 1      | integer | ]    |
+
+**Table A.32 – Content element name for drep**
+
+| content | length | type | loop |
+|---------|--------|------|------|
+| gtso    | –      | box  |      |
+
+**Table A.33 – Content element name for gtso**
+
+| content | length   | type    | loop |
+|---------|----------|---------|------|
+| profile | variable | hexbyte |      |
+
+**Table A.34 – Content element name for creg**
+
+| content         | length | type    | loop |
+|-----------------|--------|---------|------|
+| hori_size       | 2      | integer |      |
+| vert_size       | 2      | integer |      |
+| cds_num         | 2      | integer |      |
+| hori_resolution | 1      | integer |      |
+| vert_resolution | 1      | integer |      |
+| hori_offset     | 1      | integer |      |
+| vert_offset     | 1      | integer |      |
+
+**Table A.35 – Content element name for comp**
+
+| content | length | type | loop |
+|---------|--------|------|------|
+| copt    | –      | box  | =1   |
+| inst    | –      | box  |      |
+
+**Table A.36 – Content element name for copt**
+
+| content | length | type    | loop |
+|---------|--------|---------|------|
+| height  | 4      | integer |      |
+| width   | 4      | integer |      |
+| loop    | 1      | integer |      |
+
+**Table A.37 – Content element name for inst**
+
+| content     | length   | type    | loop |
+|-------------|----------|---------|------|
+| type        | 2        | integer |      |
+| repetition  | 2        | integer |      |
+| duration    | 1        | integer |      |
+| instruction | variable | hexbyte |      |
+
+Table A.38 – Content element name for instruction
+
+| instruction      | length | type    | loop |
+|------------------|--------|---------|------|
+| hori_offset      | 0, 4   | integer |      |
+| vert_offset      | 0, 4   | integer |      |
+| width            | 0, 4   | integer |      |
+| height           | 0, 4   | integer |      |
+| life             | 0, 4   | integer |      |
+| next_use         | 0, 4   | integer |      |
+| hori_crop_offset | 0, 4   | integer |      |
+| vert_crop_offset | 0, 4   | integer |      |
+| crop_width       | 0, 4   | integer |      |
+| crop_height      | 0, 4   | integer |      |
+
+Table A.39 – Content element name for roid
+
+| content     | length | type    | loop |
+|-------------|--------|---------|------|
+| num_entries | 1      | integer |      |
+| contained   | 1      | integer |      |
+| type        | 1      | integer |      |
+| priority    | 1      | integer |      |
+| left        | 4      | integer |      |
+| top         | 4      | integer |      |
+| width       | 4      | integer |      |
+| height      | 4      | integer |      |
+
+Table A.40 – Content element name for asoc
+
+| content                | length | type | loop |
+|------------------------|--------|------|------|
+| <i>Association box</i> | –      | box  | =1   |
+| <i>Associated box</i>  | –      | box  | ⌋    |
+
+Table A.41 – Content element name for nlst
+
+| content  | length | type    | loop |
+|----------|--------|---------|------|
+| asoc_num | 4      | integer | ⌋    |
+
+Table A.42 – Content element name for bfil
+
+| content | length   | type    | loop |
+|---------|----------|---------|------|
+| type    | 16       | integer |      |
+| data    | variable | hexbyte |      |
+
+Table A.43 – Content element name for chck
+
+| content        | length | type    | loop |
+|----------------|--------|---------|------|
+| signature_type | 1      | integer |      |
+| source_type    | 1      | integer |      |
+| offset         | 0, 8   | integer |      |
+| length         | 0, 8   | integer |      |
+| data           | length | hexbyte |      |
+
+#### A.2.2 Definitions of motion picture format
+
+The box file formats defined in Rec. ITU-T T.802 | ISO/IEC 15444-3 and ISO/IEC 15444-12 are designed to represent a motion picture image. Table A.44 is the box element and element structures for these file formats. These content element names and types are defined in the following tables.
+
+Table A.44 – Box element structure for a motion/video image
+
+| Element name | Box name                                    | Part 3   | Part 12  |
+|--------------|---------------------------------------------|----------|----------|
+| jP_          | <i>JPEG family signature box</i>            | required |          |
+| ftyp         | <i>File type and compatibility box</i>      | required | required |
+| pdin         | <i>Progressive download information box</i> |          | optional |
+| moov         | <i>Movie box (superbox)</i>                 | required | required |
+| mvhd         | <i>Movie header box</i>                     | required | required |
+| trak         | <i>Track box (superbox)</i>                 | required | required |
+| tkhd         | <i>Tack header box</i>                      | required | required |
+| tref         | <i>Track reference container box</i>        | optional | optional |
+| edts         | <i>Edit list container box (superbox)</i>   | optional | optional |
+| elst         | <i>Edit list box</i>                        | optional | optional |
+| udta         | <i>User-data box (superbox)</i>             | optional | optional |
+| cpri         | <i>Copyright box</i>                        | optional | optional |
+| tsel         | <i>Track selection box</i>                  | optional | optional |
+| mdia         | <i>Media box (superbox)</i>                 | required | required |
+| mdhd         | <i>Media header box</i>                     | required | required |
+| hdlr         | <i>Handler box</i>                          | required | required |
+| minf         | <i>Media information box (superbox)</i>     | required | required |
+| vmhd         | <i>Video media header box</i>               | optional | optional |
+| smhd         | <i>Sound media header box</i>               | optional | optional |
+| hmhd         | <i>Hint media header box</i>                | optional | optional |
+| dinf         | <i>Data information box (superbox)</i>      | required | required |
+| dref         | <i>Data reference box</i>                   | required | required |
+| url_   urn_  | <i>Data entry URL or Data entry URN</i>     | optional | optional |
+
+Table A.44 – Box element structure for a motion/video image
+
+| Element name |      |      |             |      | Box name                                    | Part 3   | Part 12  |
+|--------------|------|------|-------------|------|---------------------------------------------|----------|----------|
+|              |      |      |             | url_ | Data entry URL                              | optional | optional |
+|              |      |      |             | urn_ | Data entry URN                              | optional | optional |
+|              |      |      | stbl        |      | Sample table box (superbox)                 | required | required |
+|              |      |      | stsd        |      | Sample descriptions box                     | required | required |
+|              |      |      |             | mjp2 | Video sample entry box                      | optional |          |
+|              |      |      |             | jp2h | JP2 header box (superbox)                   | required |          |
+|              |      |      |             | fiel | Field coding box                            | optional |          |
+|              |      |      |             | jp2p | Motion JPEG 2000 profile box                | optional |          |
+|              |      |      |             | jp2x | Motion JPEG 2000 prefix box                 | optional |          |
+|              |      |      |             | jsub | Motion JPEG 2000 sub-sampling box           | optional |          |
+|              |      |      |             | orfo | Motion JPEG 2000 original format box        | optional | optional |
+|              |      |      |             | raw_ | Audio sample entry box                      | optional |          |
+|              |      |      |             | twos | Audio sample entry box                      | optional |          |
+|              |      |      | stts        |      | Time-to-sample box (decoding)               | required | required |
+|              |      |      | ctts        |      | Time-to-sample box (composition)            |          | optional |
+|              |      |      | stsc        |      | Sample-to-chunk box                         | required | required |
+|              |      |      | stsz        |      | Sample sizes box                            | required | optional |
+|              |      |      | stz2        |      | Compact sample size box                     |          | optional |
+|              |      |      | stco   co64 |      | Chunk offset box (32 bit or 64 bit)         | required | required |
+|              |      |      | stss        |      | Sync sample table box                       |          | optional |
+|              |      |      | stsh        |      | Shadow sync sample table box                |          | optional |
+|              |      |      | padb        |      | Sample padding bits box                     |          | optional |
+|              |      |      | stdp        |      | Sample degradation box                      |          | optional |
+|              |      |      | sdtp        |      | Independent and disposable sample box       |          | optional |
+|              |      |      | sbgp        |      | Sample-to-group box                         |          | optional |
+|              |      |      | sgpd        |      | Sample group description box                |          | optional |
+|              |      |      | subs        |      | Sub-sample information box                  |          | optional |
+|              |      | meta |             |      | Metadata box                                |          | optional |
+|              | meta |      |             |      | Metadata box                                |          | optional |
+|              | udta |      |             |      | User-data box (superbox)                    | optional | optional |
+|              | mvex |      |             |      | Movie extends box (superbox)                | optional | optional |
+|              |      | mehd |             |      | Movie extends header box                    | optional | optional |
+|              |      | trex |             |      | Track extends defaults box                  | required | required |
+|              |      |      | ipmc        |      | IPMP control box                            |          | optional |
+| mdat         |      |      |             |      | Media data container box                    | optional | optional |
+| moof         |      |      |             |      | Movie fragment box (superbox)               | optional | optional |
+|              | mfhd |      |             |      | Movie fragment header box                   | required | required |
+|              | traf |      |             |      | Track fragment box (superbox)               | optional | optional |
+|              |      | tfhd |             |      | Track fragment header box                   | required | required |
+|              |      | trun |             |      | Track fragment run box                      | optional | optional |
+|              |      | sdtp |             |      | Independent and disposable sample box       |          | optional |
+|              |      | sbgp |             |      | Sample-to-group box                         |          | optional |
+|              |      | subs |             |      | Sub-sample information box                  |          | optional |
+| mfra         |      |      |             |      | Movie fragment random access box (superbox) | optional | optional |
+|              | tfra |      |             |      | Track fragment random access box            | optional | optional |
+|              | mfro |      |             |      | Movie fragment rand. access offset box      | required | required |
+| meta         |      |      |             |      | Metadata box                                |          | optional |
+|              | hdlr |      |             |      | Handler box                                 |          | required |
+|              | dinf |      |             |      | Data information box (superbox)             |          | optional |
+|              | ipmc |      |             |      | IPMP control box                            |          | optional |
+
+**Table A.44 – Box element structure for a motion/video image**
+
+| Element name |      |      |      | Box name                                     | Part 3   | Part 12  |
+|--------------|------|------|------|----------------------------------------------|----------|----------|
+|              | iloc |      |      | Item location box                            |          | optional |
+|              | ipro |      |      | Item protection box                          |          | optional |
+|              |      | sinf |      | Protection scheme information box (superbox) |          | optional |
+|              |      |      | frma | Original format box                          |          | optional |
+|              |      |      | imif | IPMP information box                         |          | optional |
+|              |      |      | schm | Scheme type box                              |          | optional |
+|              |      |      | schi | Scheme information box (superbox)            |          | optional |
+|              | iinf |      |      | Item information box                         |          | optional |
+|              | _xml |      |      | XML container box                            |          | optional |
+|              | bxml |      |      | Binary XML container box                     |          | optional |
+|              | pitm |      |      | Primary item reference box                   |          | optional |
+|              | fiin |      |      | File delivery item information box           |          | optional |
+|              |      | paen |      | Partition entry box (superbox)               |          | optional |
+|              |      |      | fpar | File pattern box                             |          | optional |
+|              |      |      | fecr | FEC reservoir box                            |          | optional |
+|              |      | segr |      | File delivery session group box              |          | optional |
+|              |      | gitn |      | Group id name box                            |          | optional |
+|              |      | tsel |      | Track selection box                          |          | optional |
+|              | dinf |      |      | Data information box (superbox)              |          | optional |
+| meco         |      |      |      | Additional metadata container box (superbox) |          | optional |
+|              | mere |      |      | Metabox relation box                         |          | optional |
+|              | meta |      |      | Metadata box                                 |          | optional |
+| skip   free  |      |      |      | Free space box                               | optional | optional |
+
+##### **A.2.2.1 Box element definitions for JPEG 2000 Part 3 format**
+
+**Table A.45 – Content element name for mjp2**
+
+| content         | length   | type    | loop |
+|-----------------|----------|---------|------|
+| reserved        | 6        | integer |      |
+| data_reference  | 2        | integer |      |
+| predefined      | 2        | integer |      |
+| reserved        | 2        | integer |      |
+| predefined      | 12       | integer |      |
+| width           | 2        | integer |      |
+| height          | 2        | integer |      |
+| hori_resolution | 4        | integer |      |
+| vert_resolution | 4        | integer |      |
+| reserved        | 4        | integer |      |
+| predefined      | 2        | integer |      |
+| name            | 32       | string  |      |
+| depth           | 2        | integer |      |
+| predefined      | 2        | integer |      |
+| jp2h            | —        | box     |      |
+| fiel            | optional | box     |      |
+| jp2p            | optional | box     |      |
+| jp2x            | optional | box     |      |
+| jsub            | optional | box     |      |
+| orfo            | optional | box     |      |
+
+**Table A.46 – Content element name for fiel**
+
+| content     | length | type    | loop |
+|-------------|--------|---------|------|
+| field_count | 1      | integer |      |
+| field_order | 1      | integer |      |
+
+**Table A.47 – Content element name for jp2p**
+
+| content       | length | type    | loop |
+|---------------|--------|---------|------|
+| version       | 1      | integer |      |
+| flag          | 3      | integer |      |
+| compatibility | 4      | integer |      |
+
+**Table A.48 – Content element name for jp2x**
+
+| content    | length   | type    | loop |
+|------------|----------|---------|------|
+| codestream | variable | hexbyte |      |
+
+**Table A.49 – Content element name for fiel**
+
+| content     | length | type    | loop |
+|-------------|--------|---------|------|
+| field_count | 1      | integer |      |
+| field_order | 1      | integer |      |
+
+**Table A.50 – Content element name for orfo**
+
+| content              | length | type    | loop |
+|----------------------|--------|---------|------|
+| original_field_count | 1      | integer |      |
+| original_field_order | 1      | integer |      |
+
+**Table A.51 – Content element name for jsub**
+
+| content     | length | type    | loop |
+|-------------|--------|---------|------|
+| hori_sub    | 1      | integer |      |
+| vert_sub    | 1      | integer |      |
+| hori_offset | 1      | integer |      |
+| vert_offset | 1      | integer |      |
+
+**Table A.52 – Content element name for raw\_ and twos**
+
+| content        | length | type    | loop |
+|----------------|--------|---------|------|
+| reserved       | 6      | integer |      |
+| data_reference | 2      | integer |      |
+| reserved       | 8      | integer |      |
+| channel_count  | 2      | integer |      |
+| sample_size    | 2      | integer |      |
+| predefined     | 2      | integer |      |
+| reserved       | 2      | integer |      |
+| sample_rate    | 4      | integer |      |
+
+##### **A.2.2.2 Box element definitions for JPEG 2000 part 12 format**
+
+**Table A.53 – Content element name for mdat**
+
+| content | length   | type    | loop |
+|---------|----------|---------|------|
+| data    | variable | hexbyte |      |
+
+**Table A.54 – Content element name for pdin**
+
+| content      | length | type    | loop |
+|--------------|--------|---------|------|
+| version      | 1      | integer |      |
+| flag         | 3      | integer |      |
+| rate         | 4      | integer | ]    |
+| inital_dalay | 4      | integer |      |
+
+**Table A.55 – Content element name for moov**
+
+| content | length   | type | loop |
+|---------|----------|------|------|
+| mvhd    | –        | box  | =1   |
+| trak    | –        | box  | ≥1   |
+| mvex    | optional | box  | ≤1   |
+| udta    | optional | box  | ≤1   |
+| meta    | optional | box  | ≤1   |
+| meco    | optional | box  | ≤1   |
+| ipmc    | optional | box  | ≤1   |
+
+**Table A.56 – Content element name for mvhd**
+
+| content           | length | type    | loop |
+|-------------------|--------|---------|------|
+| version           | 1      | integer |      |
+| flag              | 3      | integer |      |
+| creation_time     | 4, 8   | integer |      |
+| modification_time | 4, 8   | integer |      |
+| time_scale        | 4      | integer |      |
+| duration          | 4, 8   | integer |      |
+| rate              | 4      | integer |      |
+| volume            | 2      | integer |      |
+| reserved          | 10     | integer |      |
+| matrix            | 36     | hexbyte |      |
+| predefined        | 24     | integer |      |
+| next_track_id     | 4      | integer |      |
+
+**Table A.57 – Content element name for free and skip**
+
+| content | length   | type    | loop |
+|---------|----------|---------|------|
+| data    | variable | hexbyte |      |
+
+**Table A.58 – Content element name for trak**
+
+| content | length   | type | loop |
+|---------|----------|------|------|
+| tkhd    | –        | box  | =1   |
+| mdia    | –        | box  | =1   |
+| tref    | optional | box  | ≤1   |
+| edts    | optional | box  | ≤1   |
+| udta    | optional | box  | ≤1   |
+| meta    | optional | box  | ≤1   |
+| meco    | optional | box  | ≤1   |
+
+**Table A.59 – Content element name for tkhd**
+
+| content           | length | type    | loop |
+|-------------------|--------|---------|------|
+| version           | 1      | integer |      |
+| flag              | 3      | integer |      |
+| creation_time     | 4, 8   | integer |      |
+| modification_time | 4, 8   | integer |      |
+| track_id          | 4      | integer |      |
+| reserved          | 4      | integer |      |
+| duration          | 4, 8   | time    |      |
+| reserved          | 8      | integer |      |
+| layer             | 2      | integer |      |
+| alternate_group   | 2      | integer |      |
+| volume            | 2      | integer |      |
+| reserved          | 2      | integer |      |
+| matrix            | 36     | hexbyte |      |
+| width             | 4      | integer |      |
+| height            | 4      | integer |      |
+
+**Table A.60 – Content element name for matrix**
+
+| matrix | length | type    | loop |
+|--------|--------|---------|------|
+| cell   | 4      | integer |      |
+
+**Table A.61 – Content element name for tref**
+
+| content            | length | type    | loop |
+|--------------------|--------|---------|------|
+| hint   cdsc   hind | –      | hexbyte |      |
+
+**Table A.62 – Content element name for hint, cdsc, and hind**
+
+| hint   cdsc   hind | length | type    | loop |
+|--------------------|--------|---------|------|
+| track_id           | 4      | integer | ]    |
+
+**Table A.63 – Content element name for mdia**
+
+| content | length | type | loop |
+|---------|--------|------|------|
+| mdhd    | –      | box  | =1   |
+| hdlr    | –      | box  | =1   |
+| minf    | –      | box  | =1   |
+
+**Table A.64 – Content element name for mdhd**
+
+| content           | length | type    | loop |
+|-------------------|--------|---------|------|
+| version           | 1      | integer |      |
+| flag              | 3      | integer |      |
+| creation_time     | 4, 8   | integer |      |
+| modification_time | 4, 8   | integer |      |
+| time_scale        | 4      | integer |      |
+| duration          | 4, 8   | integer |      |
+| language          | 2      | integer |      |
+| predefined        | 2      | integer |      |
+
+**Table A.65 – Content element name for hdlr**
+
+| content    | length   | type                                            | loop |
+|------------|----------|-------------------------------------------------|------|
+| version    | 1        | integer                                         |      |
+| flag       | 3        | integer                                         |      |
+| predefined | 4        | integer                                         |      |
+| type       | 4        | integer<br>'vide'<br>'soun'<br>'hint'<br>'meta' |      |
+| reserved   | 12       | integer                                         |      |
+| name       | variable | string                                          |      |
+
+**Table A.66 – Content element name for minf**
+
+| content                   | length | type | loop |
+|---------------------------|--------|------|------|
+| vmhd   smhd   hmhd   nmhd | –      | box  | =1   |
+| stbl                      | –      | box  | =1   |
+| dinf                      | –      | box  | =1   |
+
+**Table A.67 – Content element name for vmhd**
+
+| content      | length | type    | loop |
+|--------------|--------|---------|------|
+| version      | 1      | integer |      |
+| flag         | 3      | integer |      |
+| graphic_mode | 2      | integer |      |
+| op_code      | 2      | integer | ]    |
+
+**Table A.68 – Content element name for hmhd**
+
+| content      | length | type    | loop |
+|--------------|--------|---------|------|
+| version      | 1      | integer |      |
+| flag         | 3      | integer |      |
+| max_pdu_size | 2      | integer |      |
+| avg_pdu_size | 2      | integer |      |
+| max_bitrate  | 4      | integer |      |
+| avg_bitrate  | 4      | integer |      |
+| reserved     | 4      | integer |      |
+
+**Table A.69 – Content element name for smhd**
+
+| content  | length | type    | loop |
+|----------|--------|---------|------|
+| version  | 1      | integer |      |
+| flag     | 3      | integer |      |
+| balance  | 2      | integer |      |
+| reserved | 2      | integer |      |
+
+**Table A.70 – Content element name for stbl**
+
+| content     | length   | type | loop |
+|-------------|----------|------|------|
+| stsd        | –        | box  | =1   |
+| stdp        | optional | box  | ≤1   |
+| stts        | –        | box  | =1   |
+| ctts        | optional | box  | ≤1   |
+| stss        | optional | box  | ≤1   |
+| stsh        | optional | box  | ≤1   |
+| sdtp        | optional | box  | ≤1   |
+| stsz   stz2 | –        | box  | =1   |
+| stsc        | –        | box  | =1   |
+| stco   co64 | –        | box  | =1   |
+| padb        | optional | box  | ≤1   |
+| subs        | optional | box  | ≤1   |
+| sbgp        | optional | box  | ≥0   |
+| sgpd        | optional | box  | ≥0   |
+
+**Table A.71 – Content element name for btrt**
+
+| content     | length | type    | loop |
+|-------------|--------|---------|------|
+| buffer_size | 4      | integer |      |
+| max_bitrate | 4      | integer |      |
+| avg_bitrate | 4      | integer |      |
+
+**Table A.72 – Content element name for metx**
+
+| content          | length   | type    | loop |
+|------------------|----------|---------|------|
+| reserved         | 6        | integer |      |
+| data_reference   | 4        | integer |      |
+| content_encoding | optional | string  |      |
+| namespace        | variable | string  |      |
+| location         | optional | string  |      |
+| btrt             | optional | box     | ≥0   |
+
+**Table A.73 – Content element name for mett**
+
+| content          | length   | type    | loop |
+|------------------|----------|---------|------|
+| reserved         | 6        | integer |      |
+| data_reference   | 4        | integer |      |
+| content_encoding | optional | string  |      |
+| mine_format      | variable | string  |      |
+| btrt             | optional | box     | ≥0   |
+
+**Table A.74 – Content element name for pasp**
+
+| content      | length | type    | loop |
+|--------------|--------|---------|------|
+| hori_spacing | 4      | integer |      |
+| vert_spacing | 4      | integer |      |
+
+**Table A.75 – Content element name for clap**
+
+| content         | length | type    | loop |
+|-----------------|--------|---------|------|
+| width_num       | 4      | integer |      |
+| width_den       | 4      | integer |      |
+| height_num      | 4      | integer |      |
+| height_den      | 4      | integer |      |
+| hori_offset_num | 4      | integer |      |
+| hori_offset_den | 4      | integer |      |
+| vert_offset_num | 4      | integer |      |
+| vert_offset_den | 4      | integer |      |
+
+**Table A.76 – Content element name for Video coding**
+
+| content         | length   | type    | loop |
+|-----------------|----------|---------|------|
+| reserved        | 6        | integer |      |
+| data_reference  | 2        | integer |      |
+| predefined      | 2        | integer |      |
+| reserved        | 2        | integer |      |
+| predefined      | 12       | integer |      |
+| width           | 2        | integer |      |
+| height          | 2        | integer |      |
+| hori_resolution | 4        | integer |      |
+| vert_resolution | 4        | integer |      |
+| reserved        | 4        | integer |      |
+| predefined      | 2        | integer |      |
+| name            | 32       | string  |      |
+| depth           | 2        | integer |      |
+| predefined      | 2        | integer |      |
+| clap            | optional | box     | ≤1   |
+| pasp            | optional | box     | ≤1   |
+
+**Table A.77 – Content element name for Audio coding**
+
+| content        | length | type    | loop |
+|----------------|--------|---------|------|
+| reserved       | 6      | integer |      |
+| data_reference | 2      | integer |      |
+| reserved       | 8      | integer |      |
+| channel_count  | 2      | integer |      |
+| sample_size    | 2      | integer |      |
+| predefined     | 2      | integer |      |
+| reserved       | 2      | integer |      |
+| sample_rate    | 4      | integer |      |
+
+**Table A.78 – Content element name for stsd**
+
+| content            | length | type    | loop |
+|--------------------|--------|---------|------|
+| version            | 1      | integer |      |
+| flag               | 3      | integer |      |
+| num_entries        | 4      | integer |      |
+| mjpeg   raw   twos | –      | box     | ⌋    |
+
+**Table A.79 – Content element name for stdp**
+
+| content  | length | type    | loop |
+|----------|--------|---------|------|
+| version  | 1      | integer |      |
+| flag     | 3      | integer |      |
+| priority | 2      | integer | ⌋    |
+
+**Table A.80 – Content element name for stsl**
+
+| content          | length | type    | loop |
+|------------------|--------|---------|------|
+| version          | 1      | integer |      |
+| flag             | 3      | integer |      |
+| constant_flag    | 1      | integer |      |
+| scale_method     | 1      | integer |      |
+| display_center_x | 2      | integer |      |
+| display_center_y | 2      | integer |      |
+
+**Table A.81 – Content element name for stts**
+
+| content      | length | type    | loop |
+|--------------|--------|---------|------|
+| version      | 1      | integer |      |
+| flag         | 3      | integer |      |
+| num_entries  | 4      | integer |      |
+| sample_count | 4      | integer | ⌋    |
+| sample_delta | 4      | integer |      |
+
+**Table A.82 – Content element name for ctts**
+
+| content       | length | type    | loop |
+|---------------|--------|---------|------|
+| version       | 1      | integer |      |
+| flag          | 3      | integer |      |
+| num_entries   | 4      | integer |      |
+| sample_count  | 4      | integer | ⌋    |
+| sample_offset | 4      | integer |      |
+
+**Table A.83 – Content element name for stss**
+
+| content       | length | type    | loop |
+|---------------|--------|---------|------|
+| version       | 1      | integer |      |
+| flag          | 3      | integer |      |
+| num_entries   | 4      | integer |      |
+| sample_number | 4      | box     | ⌋    |
+
+**Table A.84 – Content element name for stsh**
+
+| content                | length | type    | loop |
+|------------------------|--------|---------|------|
+| version                | 1      | integer |      |
+| flag                   | 3      | integer |      |
+| num_entries            | 4      | integer |      |
+| shadowed_sample_number | 4      | integer | ⌋    |
+| sync_sample_number     | 4      | integer |      |
+
+**Table A.85 – Content element name for sdtb**
+
+| content               | length | type    | loop |
+|-----------------------|--------|---------|------|
+| version               | 1      | integer |      |
+| flag                  | 3      | integer |      |
+| reserved              | 2      | integer | ⌋    |
+| sample_depends_on     | 2      | integer |      |
+| sample_is_depends_on  | 2      | integer |      |
+| sample_has_redundancy | 2      | integer |      |
+
+**Table A.86 – Content element name for edts**
+
+| content | length   | type | loop |
+|---------|----------|------|------|
+| elst    | optional | box  | ≤1   |
+
+**Table A.87 – Content element name for elst**
+
+| content             | length | type    | loop |
+|---------------------|--------|---------|------|
+| version             | 1      | integer |      |
+| flag                | 3      | integer |      |
+| num_entries         | 4      | integer |      |
+| segment_duration    | 4, 8   | integer | ]    |
+| media_time          | 4, 8   | integer |      |
+| media_rate_integer  | 2      | integer |      |
+| media_rate_fraction | 2      | integer |      |
+
+**Table A.88 – Content element name for dinf**
+
+| content          | length | type | loop |
+|------------------|--------|------|------|
+| dref  url_  urn_ | –      | box  | =1   |
+
+**Table A.89 – Content element name for url\_**
+
+| content  | length   | type    | loop |
+|----------|----------|---------|------|
+| version  | 1        | integer |      |
+| flag     | 3        | integer |      |
+| location | variable | string  |      |
+
+**Table A.90 – Content element name for urn\_**
+
+| content  | length   | type    | loop |
+|----------|----------|---------|------|
+| version  | 1        | integer |      |
+| flag     | 3        | integer |      |
+| name     | variable | string  |      |
+| location | variable | string  |      |
+
+**Table A.91 – Content element name for dref**
+
+| content     | length | type    | loop |
+|-------------|--------|---------|------|
+| version     | 1      | integer |      |
+| flag        | 3      | integer |      |
+| num_entries | 4      | integer |      |
+| url_  urn_  | –      | box     | ]    |
+
+**Table A.92 – Content element name for stsz**
+
+| content     | length | type    | loop |
+|-------------|--------|---------|------|
+| version     | 1      | integer |      |
+| flag        | 3      | integer |      |
+| sample_size | 4      | integer |      |
+| num_entries | 4      | integer |      |
+| entry_size  | 0, 4   | integer | ]    |
+
+**Table A.93 – Content element name for stz2**
+
+| content     | length     | type    | loop |
+|-------------|------------|---------|------|
+| version     | 1          | integer |      |
+| flag        | 3          | integer |      |
+| reserved    | 3          | integer |      |
+| field_size  | 1          | integer |      |
+| num_entries | 4          | integer |      |
+| entry_size  | filed_size | integer | ]    |
+
+**Table A.94 – Content element name for stsc**
+
+| content           | length | type    | loop |
+|-------------------|--------|---------|------|
+| version           | 1      | integer |      |
+| flag              | 3      | integer |      |
+| num_entries       | 4      | integer |      |
+| first_chunk       | 4      | integer | ]    |
+| sample_per_chunk  | 4      | integer |      |
+| description_index | 4      | integer |      |
+
+**Table A.95 – Content element name for stco**
+
+| content      | length | type    | loop |
+|--------------|--------|---------|------|
+| version      | 1      | integer |      |
+| flag         | 3      | integer |      |
+| num_entries  | 4      | integer |      |
+| chunk_offset | 4      | integer | ]    |
+
+**Table A.96 – Content element name for co64**
+
+| content      | length | type    | loop |
+|--------------|--------|---------|------|
+| version      | 1      | integer |      |
+| flag         | 3      | integer |      |
+| num_entries  | 4      | integer |      |
+| chunk_offset | 8      | integer | ]    |
+
+**Table A.97 – Content element name for padb**
+
+| content | length | type    | loop |
+|---------|--------|---------|------|
+| version | 1      | integer |      |
+| flag    | 3      | integer |      |
+| pad1    | 4      | integer | ]    |
+| pad2    | 8      | integer |      |
+
+**Table A.98 – Content element name for subs**
+
+| content            | length | type    | loop |
+|--------------------|--------|---------|------|
+| version            | 1      | integer |      |
+| flag               | 3      | integer |      |
+| num_entries        | 4      | integer |      |
+| sample_delta       | 4      | integer | ]    |
+| num_subsample      | 2      | integer |      |
+| subsample_size     | 4, 8   | integer |      |
+| subsample_priority | 1      | integer |      |
+| discardable        | 1      | integer |      |
+| reserved           | 4      | integer |      |
+
+**Table A.99 – Content element name for mvex**
+
+| content | length   | type | loop |
+|---------|----------|------|------|
+| mehd    | optional | box  | ≤1   |
+| trex    | –        | box  | =1   |
+
+**Table A.100 – Content element name for mehd**
+
+| content           | length | type    | loop |
+|-------------------|--------|---------|------|
+| version           | 1      | integer |      |
+| flag              | 3      | integer |      |
+| fragment_duration | 4, 8   | integer |      |
+
+**Table A.101 – Content element name for trex**
+
+| content                 | length | type    | loop |
+|-------------------------|--------|---------|------|
+| version                 | 1      | integer |      |
+| flag                    | 3      | integer |      |
+| track_id                | 4      | integer |      |
+| default_sample_index    | 4      | integer |      |
+| default_sample_duration | 4      | integer |      |
+| default_sample_size     | 4      | integer |      |
+| default_sample_flags    | 4      | integer |      |
+
+**Table A.102 – Content element name for moof**
+
+| content | length | type | loop |
+|---------|--------|------|------|
+| mfhd    | –      | box  |      |
+| traf    | –      | box  |      |
+
+**Table A.103 – Content element name for mfhd**
+
+| content         | length | type    | loop |
+|-----------------|--------|---------|------|
+| version         | 1      | integer |      |
+| flag            | 3      | integer |      |
+| sequence_number | 4      | integer |      |
+
+**Table A.104 – Content element name for traf**
+
+| content | length   | type | loop |
+|---------|----------|------|------|
+| tfhd    | –        | box  | =1   |
+| traf    | optional | box  | ≥0   |
+| trun    | optional | box  | ≥0   |
+
+**Table A.105 – Content element name for tfhd**
+
+| content                  | length | type    | loop |
+|--------------------------|--------|---------|------|
+| version                  | 1      | integer |      |
+| flag                     | 3      | integer |      |
+| track_id                 | 4      | integer |      |
+| base_data_offset         | 8      | integer |      |
+| sample_description_index | 4      | integer |      |
+| default_sample_duration  | 4      | integer |      |
+| default_sample_size      | 4      | integer |      |
+| default_sample_flags     | 4      | integer |      |
+
+**Table A.106 – Content element name for trun**
+
+| content            | length | type    | loop |
+|--------------------|--------|---------|------|
+| version            | 1      | integer |      |
+| flag               | 3      | integer |      |
+| num_entries        | 4      | integer |      |
+| data_offset        | 4      | integer |      |
+| first_sample_flags | 4      | integer |      |
+| sample_duration    | 4      | integer | ]    |
+| sample_size        | 4      | integer |      |
+| sample_flags       | 4      | integer |      |
+| sample_time_offset | 4      | integer |      |
+
+**Table A.107 – Content element name for mfra**
+
+| content | length | type | loop |
+|---------|--------|------|------|
+| tfra    | –      | box  |      |
+| mfro    | –      | box  |      |
+
+**Table A.108 – Content element name for tfra**
+
+| content           | length              | type    | loop |
+|-------------------|---------------------|---------|------|
+| version           | 1                   | integer |      |
+| flag              | 3                   | integer |      |
+| track_id          | 4                   | integer |      |
+| reserved          | 13/4                | integer |      |
+| traf_index_size   | 1/4                 | integer |      |
+| trun_index_size   | 1/4                 | integer |      |
+| sample_index_size | 1/4                 | integer |      |
+| num_entries       | 4                   | integer |      |
+| time              | 4, 8                | integer | ]    |
+| moof_offset       | 4, 8                | integer |      |
+| traf_index        | traf_index_size+1   | integer |      |
+| trun_index        | trun_index_size+1   | integer |      |
+| sample_index      | sample_index_size+1 | integer |      |
+
+**Table A.109 – Content element name for sbgp**
+
+| content                 | length | type    | loop |
+|-------------------------|--------|---------|------|
+| version                 | 1      | integer |      |
+| flag                    | 3      | integer |      |
+| type                    | 4      | integer |      |
+| num_entries             | 4      | integer |      |
+| sample_count            | 4      | integer | ]    |
+| group_description_index | 4      | integer |      |
+
+**Table A.110 – Content element name for sgpd**
+
+| content            | length   | type    | loop |
+|--------------------|----------|---------|------|
+| version            | 1        | integer |      |
+| flag               | 3        | integer |      |
+| type               | 4        | integer |      |
+| default_length     | 0, 4     | integer |      |
+| num_entries        | 4        | integer |      |
+| description_length | 0, 4     | integer | ]    |
+| data               | variable | hexbyte |      |
+
+**Table A.111 – Content element name for udta**
+
+| content | length   | type | loop |
+|---------|----------|------|------|
+| cprt    | optional | box  | ≥0   |
+
+**Table A.112 – Content element name for cprt**
+
+| content  | length   | type    | loop |
+|----------|----------|---------|------|
+| version  | 1        | integer |      |
+| flag     | 3        | integer |      |
+| language | 2        | integer |      |
+| notice   | variable | string  |      |
+
+**Table A.113 – Content element name for tsel**
+
+| content      | length | type    | loop |
+|--------------|--------|---------|------|
+| version      | 1      | integer |      |
+| flag         | 3      | integer |      |
+| switch_group | 4      | integer |      |
+| attributes   | 4      | integer |      |
+
+**Table A.114 – Content element name for meta**
+
+| content      | length   | type    | loop |
+|--------------|----------|---------|------|
+| version      | 1        | integer |      |
+| flag         | 3        | integer |      |
+| _xml_   bxml | optional | box     | ≤1   |
+| iloc         | optional | box     | ≤1   |
+| pitm         | optional | box     | ≤1   |
+| ipro         | optional | box     | ≤1   |
+| iinf         | optional | box     | ≤1   |
+| ipmc         | optional | box     | ≤1   |
+| fiim         | optional | box     | ≤1   |
+| hdlr         | –        | box     | ≤1   |
+| dinf         | –        | box     | ≤1   |
+
+**Table A.115 – Content element name for \_xml\_**
+
+| content | length   | type    | loop |
+|---------|----------|---------|------|
+| version | 1        | integer |      |
+| flag    | 3        | integer |      |
+| text    | variable | string  |      |
+
+**Table A.116 – Content element name for bxml**
+
+| content | length   | type    | loop |
+|---------|----------|---------|------|
+| version | 1        | integer |      |
+| flag    | 3        | integer |      |
+| data    | variable | hexbyte |      |
+
+**Table A.117 – Content element name for iloc**
+
+| content          | length           | type    | loop |   |
+|------------------|------------------|---------|------|---|
+| version          | 1                | integer |      |   |
+| flag             | 3                | integer |      |   |
+| offset_size      | 1/2              | integer |      |   |
+| length_size      | 1/2              | integer |      |   |
+| base_offset_size | 1/2              | integer |      |   |
+| reserved         | 1/2              | integer |      |   |
+| num_entries      | 2                | integer |      |   |
+| item_id          | 2                | integer | ]    |   |
+| data_reference   | 2                | integer |      |   |
+| base_offset      | base_offset_size | integer |      |   |
+| extent_count     | 2                | integer |      | ] |
+| extent_offset    | offset_size      | integer |      |   |
+| extent_length    | length_size      | integer |      |   |
+
+| content | length | type    | loop |
+|---------|--------|---------|------|
+| version | 1      | integer |      |
+| flag    | 3      | integer |      |
+| item_id | 2      | integer |      |
+
+**Table A.118 – Content element name for ipro**
+
+| content     | length | type    | loop |
+|-------------|--------|---------|------|
+| version     | 1      | integer |      |
+| flag        | 3      | integer |      |
+| num_entries | 2      | integer |      |
+| sinf        | –      | box     | ]    |
+
+**Table A.119 – Content element name for infe**
+
+| content               | length   | type    | loop |
+|-----------------------|----------|---------|------|
+| version               | 1        | integer |      |
+| flag                  | 3        | integer |      |
+| item_id               | 2        | integer |      |
+| item_protection_index | 2        | integer |      |
+| item_name             | variable | string  |      |
+| content_type          | variable | string  |      |
+| content_encoding      | variable | string  |      |
+| type                  | 0, 4     | integer |      |
+| data                  | variable | box     | ]    |
+
+**Table A.120 – Content element name for iinf**
+
+| content     | length   | type    | loop |
+|-------------|----------|---------|------|
+| version     | 1        | integer |      |
+| flag        | 3        | integer |      |
+| num_entries | 2        | integer |      |
+| infe        | variable | box     | ]    |
+
+**Table A.121 – Content element name for meco**
+
+| content | length   | type | loop |
+|---------|----------|------|------|
+| mere    | optional | box  | ≥0   |
+| meta    | –        | box  | ≥1   |
+
+**Table A.122 – Content element name for mere**
+
+| content             | length | type    | loop |
+|---------------------|--------|---------|------|
+| version             | 1      | integer |      |
+| flag                | 3      | integer |      |
+| first_metabox_type  | 4      | integer |      |
+| second_metabox_type | 4      | integer |      |
+| metabox_relation    | 1      | integer |      |
+
+**Table A.123 – Content element name for sinf**
+
+| content | length   | type | loop |
+|---------|----------|------|------|
+| frma    | –        | box  | =1   |
+| imif    | optional | box  | ≤1   |
+| schm    | optional | box  | ≤1   |
+| schi    | optional | box  | ≤1   |
+
+**Table A.124 – Content element name for frma**
+
+| content     | length | type    | loop |
+|-------------|--------|---------|------|
+| data_format | 4      | integer |      |
+
+**Table A.125 – Content element name for imif**
+
+| content          | length | type    | loop |
+|------------------|--------|---------|------|
+| version          | 1      | integer |      |
+| flag             | 3      | integer |      |
+| metabox_relation | 1      | hexbyte | ]    |
+
+**Table A.126 – Content element name for ipmc**
+
+| content          | length | type    | loop |
+|------------------|--------|---------|------|
+| version          | 1      | integer |      |
+| flag             | 3      | integer |      |
+| tool_list        | –      | hexbyte |      |
+| num_entries      | 1      | integer |      |
+| metabox_relation | –      | hexbyte | ]    |
+
+**Table A.127 – Content element name for schm**
+
+| content  | length   | type    | loop |
+|----------|----------|---------|------|
+| version  | 1        | integer |      |
+| flag     | 3        | integer |      |
+| type     | 4        | integer |      |
+| version  | 4        | integer |      |
+| location | variable | string  |      |
+
+**Table A.128 – Content element name for schi**
+
+| content                 | length | type | loop |
+|-------------------------|--------|------|------|
+| <i>Additional boxes</i> | –      | box  | ]    |
+
+**Table A.129 – Content element name for paen**
+
+| content | length   | type | loop |
+|---------|----------|------|------|
+| fpar    | –        | box  | =1   |
+| fecr    | optional | box  | ≤1   |
+
+**Table A.130 – Content element name for fiin**
+
+| content     | length   | type    | loop |
+|-------------|----------|---------|------|
+| version     | 1        | integer |      |
+| flag        | 3        | integer |      |
+| num_entries | 2        | integer |      |
+| paen        | –        | box     | ]    |
+| segr        | optional | box     | ≤1   |
+| gitn        | optional | box     | ≤1   |
+
+**Table A.131 – Content element name for fpar**
+
+| content                 | length   | type    | loop |
+|-------------------------|----------|---------|------|
+| version                 | 1        | integer |      |
+| flag                    | 3        | integer |      |
+| item_id                 | 2        | integer |      |
+| packet_payload_size     | 2        | integer |      |
+| reserved                | 1        | integer |      |
+| FEC_encoding_id         | 1        | integer |      |
+| FEC_instance_id         | 2        | integer |      |
+| max_source_block_length | 2        | integer |      |
+| symbol_length           | 2        | integer |      |
+| max_num_symbols         | 2        | integer |      |
+| scheme_specific_info    | variable | string  |      |
+| num_entries             | 2        | integer |      |
+| block_count             | 2        | integer | ]    |
+| block_size              | 4        | integer |      |
+
+**Table A.132 – Content element name for fecr**
+
+| content      | length | type    | loop |
+|--------------|--------|---------|------|
+| version      | 1      | integer |      |
+| flag         | 3      | integer |      |
+| num_entries  | 2      | integer |      |
+| item_id      | 2      | integer | ]    |
+| symbol_count | 4      | integer |      |
+
+**Table A.133 – Content element name for segr**
+
+| content         | length | type    | loop |
+|-----------------|--------|---------|------|
+| num_entries     | 2      | integer |      |
+| num_groups      | 1      | integer | ]    |
+| group_id        | 4      | integer |      |
+| num_hint_tracks | 2      | integer |      |
+| hint_track_id   | 4      | integer |      |
+
+**Table A.134 – Content element name for gitn**
+
+| content     | length   | type    | loop |
+|-------------|----------|---------|------|
+| version     | 1        | integer |      |
+| flag        | 3        | integer |      |
+| num_entries | 2        | integer |      |
+| group_id    | 4        | integer | ]    |
+| group_name  | variable | string  |      |
+
+**Table A.135 – Content element name for rtp\_**
+
+| content            | length   | type    | loop |
+|--------------------|----------|---------|------|
+| reserved           | 6        | integer |      |
+| data_reference     | 2        | integer |      |
+| track_version      | 2        | integer |      |
+| compatible_version | 2        | integer |      |
+| max_packet_size    | 4        | integer |      |
+| tims               | –        | box     | ]    |
+| tsro               | optional | box     |      |
+| snro               | optional | box     |      |
+
+**Table A.136 – Content element name for srtp**
+
+| content            | length   | type    | loop |
+|--------------------|----------|---------|------|
+| reserved           | 6        | integer |      |
+| data_reference     | 2        | integer |      |
+| track_version      | 2        | integer |      |
+| compatible_version | 2        | integer |      |
+| max_packet_size    | 4        | integer |      |
+| tims               | –        | box     | ]    |
+| srpp               | –        | box     |      |
+| tsro               | optional | box     |      |
+| snro               | optional | box     |      |
+
+**Table A.137 – Content element name for tims**
+
+| content    | length | type    | loop |
+|------------|--------|---------|------|
+| time_scale | 4      | integer |      |
+
+**Table A.138 – Content element name for tsro and snro**
+
+| content | length | type    | loop |
+|---------|--------|---------|------|
+| offset  | 4      | integer |      |
+
+**Table A.139 – Content element name for srpp**
+
+| content         | length | type    | loop |
+|-----------------|--------|---------|------|
+| version         | 1      | integer |      |
+| flag            | 3      | integer |      |
+| encryption_rtp  | 4      | integer |      |
+| encryption_rtcp | 4      | integer |      |
+| integrity_rtp   | 4      | integer |      |
+| integrity_rtcp  | 4      | integer |      |
+| schm            | –      | box     | =1   |
+| schi            | –      | box     | ≤1   |
+
+**Table A.140 – Content element name for rtpo**
+
+| content | length | type    | loop |
+|---------|--------|---------|------|
+| offset  | 4      | integer |      |
+
+**Table A.141 – Content element name for hnti**
+
+| content | length | type | loop |
+|---------|--------|------|------|
+| hnti    | –      | box  | ≥0   |
+| sdp_    | –      | box  | ≥0   |
+
+**Table A.142 – Content element name for rtp\_**
+
+| content | length   | type    | loop |
+|---------|----------|---------|------|
+| format  | 4        | integer |      |
+| text    | variable | string  |      |
+
+**Table A.143 – Content element name for sdp\_**
+
+| content | length   | type   | loop |
+|---------|----------|--------|------|
+| text    | variable | string |      |
+
+**Table A.144 – Content element name for hinf**
+
+| content | length   | type | loop |
+|---------|----------|------|------|
+| trpy    | optional | box  | ≤1   |
+| nump    | optional | box  | ≤1   |
+| tpyl    | optional | box  | ≤1   |
+| totl    | optional | box  | ≤1   |
+| npck    | optional | box  | ≤1   |
+| tpay    | optional | box  | ≤1   |
+| maxr    | optional | box  | ≥0   |
+| dmed    | optional | box  | ≤1   |
+| dimm    | optional | box  | ≤1   |
+| drep    | optional | box  | ≤1   |
+| tmin    | optional | box  | ≤1   |
+| tmax    | optional | box  | ≤1   |
+| pmax    | optional | box  | ≤1   |
+| dmax    | optional | box  | ≤1   |
+| payt    | optional | box  | ≤1   |
+
+**Table A.145 – Content element name for trpy, try1, dmed, dima and drep**
+
+| content    | length | type    | loop |
+|------------|--------|---------|------|
+| bytes_sent | 8      | integer |      |
+
+**Table A.146 – Content element name for totl and tpay**
+
+| content    | length | type    | loop |
+|------------|--------|---------|------|
+| bytes_sent | 4      | integer |      |
+
+**Table A.147 – Content element name for nump**
+
+| content      | length | type    | loop |
+|--------------|--------|---------|------|
+| packets_sent | 8      | integer |      |
+
+**Table A.148 – Content element name for tmin, tmax and dmax**
+
+| content | length | type    | loop |
+|---------|--------|---------|------|
+| time    | 4      | integer |      |
+
+**Table A.149 – Content element name for npack**
+
+| content      | length | type    | loop |
+|--------------|--------|---------|------|
+| packets_sent | 4      | integer |      |
+
+**Table A.150 – Content element name for pmax**
+
+| content    | length | type    | loop |
+|------------|--------|---------|------|
+| bytes_sent | 4      | integer |      |
+
+**Table A.151 – Content element name for maxr**
+
+| content    | length | type    | loop |
+|------------|--------|---------|------|
+| period     | 4      | integer |      |
+| bytes_sent | 4      | integer |      |
+
+**Table A.152 – Content element name for hnti**
+
+| content    | length | type    | loop |
+|------------|--------|---------|------|
+| payload_id | 4      | integer |      |
+| count      | 1      | integer |      |
+| rtpmap     | count  | integer |      |
+
+**Table A.153 – Content element name for fdp\_**
+
+| content                 | length   | type    | loop |
+|-------------------------|----------|---------|------|
+| reserved                | 6        | integer |      |
+| data_reference          | 2        | integer |      |
+| track_version           | 2        | integer |      |
+| compatible_version      | 2        | integer |      |
+| partition_entry_id      | 2        | integer |      |
+| FEC_overhead            | 2        | integer |      |
+| <i>Additional boxes</i> | optional | box     | ]    |
+
+**Table A.154 – Content element name for fdsa**
+
+| content | length   | type | loop |
+|---------|----------|------|------|
+| fdpa    | variable | box  | ≥1   |
+| extr    | variable | box  | ≤1   |
+
+**Table A.155 – Content element name for fdpa**
+
+| content        | length         | type    | loop |
+|----------------|----------------|---------|------|
+| header         | 3              | hexbyte |      |
+| extension_size | 2              | integer |      |
+| extension      | extension_size | hexbyte |      |
+| packet_size    | 2              | integer |      |
+| packet         | packet_size    | hexbyte |      |
+
+Table A.156 – Content element name for extr
+
+| content | length   | type    | loop |
+|---------|----------|---------|------|
+| data    | variable | hexbyte |      |
+
+#### A.2.3 Format definitions for multiple-page documents
+
+The box file formats defined in Rec. ITU-T T.805 | ISO/IEC 15444-6 are designed to represent a multiple-page image such as a document image. These content element names and types are defined in the following tables.
+
+Table A.157 – Box element structure for a document image
+
+| Element name | Box name                            | Part 6   | Defined  |
+|--------------|-------------------------------------|----------|----------|
+| jP_          | JPEG family signature box           | required | 1        |
+| ftyp         | File type and compatibility box     | required | 1        |
+| jp2h         | JP2 header box (superbox)           | optional | 1, 2     |
+| lbl_         | Label box                           | optional | 2, 6     |
+| ihdr         | Image header box                    | optional | 1, 2, 6  |
+| bpcc         | Bits per component box              | optional | 1        |
+| colr         | Colour specification box            | optional | 1, 2, 6  |
+| pclr         | Palette box                         | optional | 1        |
+| cmap         | Component mapping box               | optional | 1        |
+| cdef         | Channel description box             | optional | 1        |
+| res_         | Resolution box (superbox)           | optional | 1        |
+| resc         | Capture resolution box              | optional | 1        |
+| resd         | Display resolution box              | optional | 1        |
+| mhdr         | Compound image header box           | required | 6        |
+| dtbl         | Data reference box                  | optional | 2, 6     |
+| jp2c         | Contiguous codestream box           | optional | 1, 2, 6  |
+| jp2i         | IPR box                             | optional | 1        |
+| xml          | XML container box                   | optional | 1, 2, 12 |
+| uuid         | UUID box                            | optional | 1        |
+| uinf         | UUID info box (superbox)            | optional | 1        |
+| ulst         | UUID list box                       | optional | 1        |
+| url_         | Data entry box                      | optional | 1        |
+| pcol         | Page collection box                 | optional | 6        |
+| ppcl         | Page collection locator box         | required | 6        |
+| pagt         | Page table box                      | required | 6        |
+| sdat         | Shared data entry box               | optional | 6        |
+| sref         | Shared data reference box           | optional | 6        |
+| page         | Page box (superbox) (1)             | required | 6        |
+| phdr         | Page header box                     | required | 6        |
+| ppcl         | Page collection locator box         | optional | 6        |
+| sptr         | Spatial transformation box          | optional | 6        |
+| phtx         | HTX Reference box                   | optional | 6        |
+| htxb         | Hidden text metadata box (superbox) | optional | 6        |
+| lobj         | Layout object box (superbox)        | optional | 6        |
+| lhdr         | Layout object header box            | required | 6        |
+| bclr         | Base colour box                     | optional | 6        |
+| bcvl         | Base colour value box               | required | 6        |
+| colr         | Colour specification box            | optional | 1, 2, 6  |
+| bpcc         | Bits per component box              | optional | 1        |
+| objc         | Object box (superbox)               | required | 6        |
+| ohdr         | Object header box                   | required | 6        |
+| scal         | Object scale box                    | optional | 6        |
+| jp2h         | JP2 header box (superbox)           | optional | 1, 2, 6  |
+| ftbl         | Fragment table box (superbox)       | optional | 2, 6     |
+| flst         | Fragment list box                   | optional | 2, 6     |
+| cref         | Cross-reference box (superbox)      | optional | 2, 6     |
+
+Table A.157 – Box element structure for a document image
+
+| Element name | Box name                               | Part 6   | Defined |
+|--------------|----------------------------------------|----------|---------|
+| flst         | Fragment list box                      | optional | 2, 6    |
+| jp2c         | Contiguous codestream box for page (1) | optional | 1, 2, 6 |
+| page         | Page box (superbox) (2)                | optional | 6       |
+| jp2c         | Contiguous codestream box for page (2) | optional | 1, 2, 6 |
+| htxb         | Hidden text metadata box (superbox)    | optional | 6       |
+
+##### A.2.3.1 Box element definitions for JPEG 2000 Part 6 format
+
+Table A.158 – Content element name for mhdr
+
+| content        | length | type    | loop |
+|----------------|--------|---------|------|
+| num_pages      | 4      | integer |      |
+| profile        | 1      | integer |      |
+| self_contained | 1      | integer |      |
+| offset         | 8      | integer |      |
+| length         | 4      | integer |      |
+| mask_coder     | 1      | integer |      |
+| image_coder    | 1      | integer |      |
+| ipr            | 1      | integer |      |
+
+Table A.159 – Content element name for pcol
+
+| content |          | type | loop |
+|---------|----------|------|------|
+| lbl_    | optional | box  | ≥0   |
+| meta    | optional | box  | ≥0   |
+| pagt    | –        | box  | =1   |
+
+Table A.160 – Content element name for ppcl
+
+| content        | length | type    | loop |
+|----------------|--------|---------|------|
+| offset         | 8      | integer |      |
+| length         | 4      | integer |      |
+| data_reference | 2      | integer |      |
+| index          | 4      | integer |      |
+
+Table A.161 – Content element name for pagt
+
+| content        | length | type    | loop |
+|----------------|--------|---------|------|
+| num_entries    | 4      | integer | ]    |
+| offset         | 8      | integer |      |
+| length         | 4      | integer |      |
+| data_reference | 2      | integer |      |
+| flag           | 1      | hexbyte |      |
+
+Table A.162 – Content element name for sdal
+
+| content | length   | type    | loop |
+|---------|----------|---------|------|
+| id      | 2        | integer |      |
+| data    | variable | hexbyte |      |
+
+Table A.163 – Content element name for sref
+
+| content | length | type    | loop |
+|---------|--------|---------|------|
+| id      | 2      | integer |      |
+
+Table A.164 – Content element name for page
+
+| content | length   | type | loop |
+|---------|----------|------|------|
+| phdr    | –        | box  | =1   |
+| ppcl    | –        | box  | ≤1   |
+| res_    | optional | box  | ≤1   |
+| bclr    | optional | box  | ≤1   |
+| meta    | optional | box  | ≥0   |
+| lbl_    | optional | box  | ≥0   |
+| lobj    | –        | box  | ≥1   |
+
+Table A.165 – Content element name for phdr
+
+| content     | length | type    | loop |
+|-------------|--------|---------|------|
+| num_lobjs   | 2      | integer |      |
+| height      | 4      | integer |      |
+| width       | 4      | integer |      |
+| orientation | 2      | integer |      |
+| colour      | 2      | integer |      |
+
+Table A.166 – Content element name for lobj
+
+| content | length   | type | loop |
+|---------|----------|------|------|
+| lhdr    | –        | box  | =1   |
+| meta    | optional | box  | ≤1   |
+| lbl_    | optional | box  | ≥0   |
+| objc    | –        | box  | =1   |
+| objc    | optional | box  | ≥1   |
+
+Table A.167 – Content element name for lhdr
+
+| content | length | type    | loop |
+|---------|--------|---------|------|
+| id      | 2      | integer |      |
+| height  | 4      | integer |      |
+| width   | 4      | integer |      |
+| top     | 4      | integer |      |
+| left    | 4      | integer |      |
+| style   | 1      | integer |      |
+
+Table A.168 – Content element name for objc
+
+| content | length   | type | loop |
+|---------|----------|------|------|
+| ohdr    | –        | box  | =1   |
+| bclr    | optional | box  | ≤1   |
+| meta    | optional | box  | ≥0   |
+| lab_    | optional | box  | ≥0   |
+| scal    | optional | box  | ≤1   |
+| jp2h    | optional | box  | ≤1   |
+
+Table A.169 – Content element name for ohdr
+
+| content        | length | type    | loop |
+|----------------|--------|---------|------|
+| type           | 1      | integer |      |
+| no_codestream  | 1      | integer |      |
+| top            | 4      | integer |      |
+| left           | 4      | integer |      |
+| offset         | 8      | integer |      |
+| length         | 4      | integer |      |
+| data_reference | 1      | integer |      |
+
+Table A.170 – Content element name for scal
+
+| content  | length | type    | loop |
+|----------|--------|---------|------|
+| vert_num | 2      | integer |      |
+| vert_den | 2      | integer |      |
+| hori_num | 2      | integer |      |
+| hori_den | 2      | integer |      |
+
+Table A.171 – Content element name for bclr
+
+| content | length   | type | loop |
+|---------|----------|------|------|
+| bcvl    | –        | box  | =1   |
+| colr    | –        | box  | =1   |
+| bpcc    | optional | box  | ≤1   |
+
+Table A.172 – Content element name for bcvl
+
+| content        | length   | type    | loop |
+|----------------|----------|---------|------|
+| num_components | 2        | integer |      |
+| depth          | 1        | integer |      |
+| data           | variable | integer |      |
+
+Table A.173 – Content element name for htxb
+
+| content      | length   | type | loop |
+|--------------|----------|------|------|
+| lbl_         | optional | box  | ≤1   |
+| _xml_   uuid | –        | box  | ≥1   |
+
+Table A.174 – Content element name for phtx
+
+| content | length   | type    | loop |
+|---------|----------|---------|------|
+| type    | 4        | integer |      |
+| flst    | –        | box     | =1   |
+| lbl_    | optional | box     | ≤1   |
+
+#### A.2.4 Security format definitions
+
+The box file formats defined in Rec. ITU-T T.807 | ISO/IEC 15444-8 are for a secure image file format. These content element names and types are defined in the following tables.
+
+Table A.175 – Box element structure for a motion/video image
+
+| Element name |      |      |      |      |      |      |  | Box name                                           | Part 8   | defined |
+|--------------|------|------|------|------|------|------|--|----------------------------------------------------|----------|---------|
+| moov         |      |      |      |      |      |      |  | Movie box (superbox)                               |          | 12      |
+|              | trak |      |      |      |      |      |  | Track box (superbox)                               |          | 12      |
+|              |      | mdia |      |      |      |      |  | Media box (superbox)                               |          | 12      |
+|              |      |      | minf |      |      |      |  | Media information box (superbox)                   |          | 12      |
+|              |      |      |      | stbl |      |      |  | Sample table box (superbox)                        | use      | 12      |
+|              |      |      |      |      | stsd |      |  | Sample descriptions box                            | use      | 12      |
+|              |      |      |      |      |      | sces |  | Scalable sample description entry box              | optional | 8       |
+|              |      |      |      |      |      | dces |  | Scalable sample description entry box              | optional | 8       |
+|              |      |      |      |      |      | encv |  | Scalable sample description entry box (enc video)  | optional | 8       |
+|              |      |      |      |      |      | autv |  | Scalable sample description entry box (auth video) | optional | 8       |
+|              |      |      |      |      |      | enct |  | Scalable sample description entry box (enc text)   | optional | 8       |
+|              |      |      |      |      |      | autt |  | Scalable sample description entry box (auth text)  | optional | 8       |
+|              |      |      |      |      |      | encs |  | Scalable sample description entry box (enc sys)    | optional | 8       |
+|              |      |      |      |      |      | auts |  | Scalable sample description entry box (auth sys)   | optional | 8       |
+|              |      |      |      |      | sbgp |      |  | Sample-to-group box                                | use      | 12      |
+|              |      |      |      |      | sgpd |      |  | Sample group description box                       | use      | 12      |
+|              |      |      |      |      |      | attr |  | Scalable sample group entry box (media char)       | optional | 8       |
+|              |      |      |      |      |      | prot |  | Scalable sample group entry box (protection)       | optional | 8       |
+|              |      |      |      |      | subs |      |  | Sub-sample information box                         |          | 12      |
+|              |      |      | meta |      |      |      |  | Metadata box                                       | use      | 12      |
+|              |      | meta |      |      |      |      |  | Metadata box                                       | use      | 12      |
+| meta         |      |      |      |      |      |      |  | Metadata box                                       | use      | 12      |
+|              | iloc |      |      |      |      |      |  | Item location box                                  | use      | 12      |
+|              | ipro |      |      |      |      |      |  | Item protection box                                | use      | 12      |
+
+Table A.175 – Box element structure for a motion/video image
+
+| Element name |      |      |      | Box name                                     | Part 8   | defined |
+|--------------|------|------|------|----------------------------------------------|----------|---------|
+|              |      | sinf |      | Protection scheme information box (superbox) | use      | 12      |
+|              |      | frma |      | Original format box                          | use      | 12      |
+|              |      | schr |      | Scheme type box                              | use      | 12      |
+|              |      | schi |      | Scheme information box (superbox)            | use      | 12      |
+|              |      | gran |      | Granularity box                              | optional | 8       |
+|              |      | vall |      | Value list box                               | optional | 8       |
+|              |      | bcip |      | Block cipher box                             | optional | 8       |
+|              |      |      | keyt | Key template box                             | optional | 8       |
+|              |      | scip |      | Stream cipher box                            | optional | 8       |
+|              |      |      | keyt | Key template box                             | optional | 8       |
+|              |      | auth |      | Authentication box                           | optional | 8       |
+|              |      |      | keyt | Key template box                             | optional | 8       |
+|              | iinf |      |      | Item information box                         | use      | 12      |
+|              | ides |      |      | Item description box                         | optional | 8       |
+|              |      | dest |      | Description type box                         | optional | 8       |
+|              |      | desd |      | Description data box                         | optional | 8       |
+|              |      | vide |      | Visual item description entry box            | optional | 8       |
+|              |      | j2ke |      | JPEG 2000 item description entry box         | optional | 8       |
+|              | icor |      |      | Item correspondence box                      | optional | 8       |
+|              | meta |      |      | Metadata box                                 | use      | 12      |
+| gprt         |      |      |      | Generic protected box                        | optional | 8       |
+
+##### A.2.4.1 Box element definitions for JPEG 2000 Part 8 format
+
+Table A.176 – Content element name for gprt
+
+|              | content          | length         | type    | loop |
+|--------------|------------------|----------------|---------|------|
+|              | type_flag        | 1/8            | integer |      |
+|              | size_flag        | 1/8            | integer |      |
+|              | location_flag    | 1/8            | integer |      |
+|              | reserved         | 5/8            | integer |      |
+| if flags ≠ 0 | num_entries      | 0, 4           | integer | }    |
+|              | offset_size      | 0, 4           | integer |      |
+|              | box_length       | 0, 4           | integer |      |
+|              | box_type         | 0, 4           | integer |      |
+|              | box_ext_length   | 0, 8           | integer |      |
+|              | offset           | 0, offset_size | integer |      |
+| else         | total_length     | 0, 4           | integer |      |
+|              | total_ext_length | 0, 8           | integer |      |
+
+Table A.177 – Content element name for sces and decs
+
+|  | content         | length   | type    | loop |
+|--|-----------------|----------|---------|------|
+|  | reserved        | 6        | integer |      |
+|  | data_reference  | 2        | integer |      |
+|  | predefined      | 2        | integer |      |
+|  | reserved        | 2        | integer |      |
+|  | predefined      | 12       | integer |      |
+|  | width           | 2        | integer |      |
+|  | height          | 2        | integer |      |
+|  | hori_resolution | 4        | integer |      |
+|  | vert_resolution | 4        | integer |      |
+|  | reserved        | 4        | integer |      |
+|  | predefined      | 2        | integer |      |
+|  | name            | 32       | string  |      |
+|  | depth           | 2        | integer |      |
+|  | predefined      | 2        | integer |      |
+|  | clap            | optional | box     | ≤1   |
+|  | pasp            | optional | box     | ≤1   |
+|  | res             | 1        | integer |      |
+|  | layer           | 1        | integer |      |
+|  | cropped_width   | 4        | integer |      |
+|  | cropped_height  | 4        | integer |      |
+|  | startx          | 0, 4     | integer |      |
+|  | starty          | 0, 4     | integer |      |
+
+**Table A.178 – Content element name for gran**
+
+| content     | length | type    | loop |
+|-------------|--------|---------|------|
+| granularity | 1      | integer |      |
+
+**Table A.179 – Content element name for vall**
+
+| content     | length | type    | loop |
+|-------------|--------|---------|------|
+| size        | 1      | integer |      |
+| num_entries | 2      | integer |      |
+| count       | 2      | integer | ⌋    |
+| value       | size   | integer | ⌋    |
+
+**Table A.180 – Content element name for keyt**
+
+| content  | length   | type    | loop |
+|----------|----------|---------|------|
+| size     | 2        | integer |      |
+| key_info | 1        | integer |      |
+| gran     | optional | box     | ≤1   |
+| vall     | –        | box     | =1   |
+
+**Table A.181 – Content element name for bcip**
+
+| content      | length | type    | loop |
+|--------------|--------|---------|------|
+| cipher_id    | 2      | integer |      |
+| cipher_mode  | 6/8    | integer |      |
+| padding_mode | 2/8    | integer |      |
+| size         | 1      | integer |      |
+| keyt         | –      | box     | =1   |
+
+**Table A.182 – Content element name for scip**
+
+| content   | length | type    | loop |
+|-----------|--------|---------|------|
+| type      | 1      | integer |      |
+| cipher_id | 2      | integer |      |
+| keyt      | –      | box     | =1   |
+
+**Table A.183 – Content element name for schi**
+
+| content       | length | type    | loop |
+|---------------|--------|---------|------|
+| type          | 1      | integer |      |
+| box_protected | 1      | integer |      |
+| bcip   scip   | –      | box     | =1   |
+| gran          | –      | box     | =1   |
+| vall          | –      | box     | =1   |
+
+**Table A.184 – Content element name for auth**
+
+| content   | length | type    | loop |
+|-----------|--------|---------|------|
+| type      | 1      | integer |      |
+| method_id | 1      | integer |      |
+| hash_id   | 1      | integer |      |
+| size      | 2      | integer |      |
+| keyt      | –      | box     | =1   |
+
+**Table A.185 – Content element name for schi**
+
+| content | length   | type    | loop |
+|---------|----------|---------|------|
+| type    | 1        | integer |      |
+| auth    | –        | box     | =1   |
+| gran    | optional | box     | ≤1   |
+| vall    | –        | box     | =1   |
+
+**Table A.186 – Content element name for ides**
+
+| content     | length | type    | loop |
+|-------------|--------|---------|------|
+| num_entries | 4      | integer |      |
+| dest        | –      | box     | ⌋    |
+| item_id     | 4      | integer |      |
+| desd        | –      | box     |      |
+
+**Table A.187 – Content element name for vide**
+
+| content     | length | type    | loop |
+|-------------|--------|---------|------|
+| layer_start | 2      | integer |      |
+| layer_count | 2      | integer |      |
+| res_start   | 2      | integer |      |
+| res_count   | 2      | integer |      |
+| hori_offset | 2      | integer |      |
+| hori_length | 2      | integer |      |
+| vert_offset | 2      | integer |      |
+| vert_length | 2      | integer |      |
+| colour      | 2      | integer |      |
+| time_start  | 2      | integer |      |
+| time_length | 2      | integer |      |
+
+**Table A.188 – Content element name for j2ke**
+
+| content          | length   | type    | loop |
+|------------------|----------|---------|------|
+| vide             | optional | box     |      |
+| tile_start       | 2        | integer |      |
+| tile_count       | 2        | integer |      |
+| precinct_start   | 2        | integer |      |
+| precinct_count   | 2        | integer |      |
+| j2k_packet_start | 2        | integer |      |
+| j2k_packet_count | 2        | integer |      |
+
+**Table A.189 – Content element name for dest**
+
+| content  | length | type    | loop |
+|----------|--------|---------|------|
+| type     | 4      | integer |      |
+| version  | 4      | integer |      |
+| location | –      | string  |      |
+
+**Table A.190 – Content element name for desd**
+
+| content               | length | type | loop |
+|-----------------------|--------|------|------|
+| <i>Additional box</i> | –      | box  | ⌋    |
+
+**Table A.191 – Content element name for icor**
+
+| content | length | type    | loop |
+|---------|--------|---------|------|
+| item_id | 2      | integer |      |
+| desc_id | 2      | integer |      |
+
+**Table A.192 – Content element name for port and attr**
+
+| content        | length | type    | loop |
+|----------------|--------|---------|------|
+| resolution     | 1      | integer |      |
+| layer          | 1      | integer |      |
+| cropped_width  | 4      | integer |      |
+| cropped_height | 4      | integer |      |
+| startx         | 0, 4   | integer |      |
+| starty         | 0, 4   | integer |      |
+
+### A.3 Examples of XML schemas
+
+The following examples are XML schemas for box types of JPEG 2000 family format.
+
+#### A.3.1 Example of an XML schema for a common header
+
+The following example is of common XML schemas for all box types of JPEG 2000 family format.
+
+```
+<?xml version="1.0" ?>
+<xs:schema xmlns:xs="http://www.iso.org/jpeg/2001/XMLSchema"
+  targetNamespace="http://www.iso.org/jpxml"
+  xmlns="http://www.iso.org/jpxml">
+  <xs:attributeGroup name="attrs.box">
+    <xs:attribute name="length" type="xs:integer" use="required" />
+    <xs:attribute name="offset" type="xs:integer" use="optional" />
+    <xs:attribute name="type" use="required">
+      <xs:simpleType>
+        <xs:restriction base="xs:string">
+          <xs:enumeration value="box" />
+        </xs:restriction>
+      </xs:simpleType>
+    </xs:attribute>
+  </xs:attributeGroup>
+  <xs:attributeGroup name="attrs.4cc">
+    <xs:attribute name="length" type="xs:integer" use="required" />
+    <xs:attribute name="type" use="required">
+      <xs:simpleType>
+        <xs:restriction base="xs:string">
+          <xs:enumeration value="fourcc" />
+        </xs:restriction>
+      </xs:simpleType>
+    </xs:attribute>
+  </xs:attributeGroup>
+  <xs:attributeGroup name="attrs.hex">
+    <xs:attribute name="length" type="xs:integer" use="required" />
+    <xs:attribute name="type" use="required">
+      <xs:simpleType>
+        <xs:restriction base="xs:string">
+          <xs:enumeration value="hexbyte" />
+        </xs:restriction>
+      </xs:simpleType>
+    </xs:attribute>
+  </xs:attributeGroup>
+  <xs:attributeGroup name="attrs.int">
+    <xs:attribute name="length" type="xs:integer" use="required" />
+    <xs:attribute name="type" use="required">
+      <xs:simpleType>
+        <xs:restriction base="xs:string">
+          <xs:enumeration value="integer" />
+        </xs:restriction>
+      </xs:simpleType>
+    </xs:attribute>
+  </xs:attributeGroup>
+  <xs:attributeGroup name="attrs.str">
+    <xs:attribute name="length" type="xs:integer" use="required" />
+    <xs:attribute name="type" use="required">
+      <xs:simpleType>
+        <xs:restriction base="xs:string">
+          <xs:enumeration value="string" />
+        </xs:restriction>
+      </xs:simpleType>
+    </xs:attribute>
+  </xs:attributeGroup>
+  <xs:attributeGroup name="attrs.url">
+    <xs:attribute name="length" type="xs:integer" use="required" />
+    <xs:attribute name="type" use="required">
+      <xs:simpleType>
+        <xs:restriction base="xs:string">
+          <xs:enumeration value="location" />
+        </xs:restriction>
+      </xs:simpleType>
+    </xs:attribute>
+  </xs:attributeGroup>
+  <xs:attributeGroup name="attrs.root">
+    <xs:attribute name="length" type="xs:integer" use="required" />
+    <xs:attribute name="name" type="xs:anyURL" use="optional" />
+  </xs:attributeGroup>
+  <!-- add following XML Schemas for the JPXML document. -->
+  ...
+</xs:schema>
+```
+
+#### **A.3.2 Example of an XML schema for a JPEG 2000 Part 1 image (single image)**
+
+```
+
+<!-- jpxml part 1 root element -->
+<xs:element name="jpxml">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.root" />
+    <xs:sequence>
+      <xs:element ref="jp  " />
+      <xs:element ref="ftyp" />
+      <xs:element ref="jp2h" />
+      <xs:element ref="jp2i" minOccurs="0" />
+      <xs:element ref="xml " minOccurs="0" />
+      <xs:element ref="uuid" minOccurs="0" />
+      <xs:element ref="uinf" minOccurs="0" />
+      <xs:element ref="jp2c" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<!-- part 1 box element -->
+<xs:element name="jp  ">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="signature" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="ftyp">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="brand" />
+      <xs:element ref="version" />
+      <xs:element ref="compatibility"
+        maxOccurs="unbounded" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="jp2h">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="ihdr" />
+      <xs:element ref="bpcc" minOccurs="0" />
+      <xs:element ref="colr" />
+      <xs:element ref="pclr" minOccurs="0" />
+      <xs:element ref="cmap" minOccurs="0" />
+      <xs:element ref="cdef" minOccurs="0" />
+      <xs:element ref="res_" minOccurs="0" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="ihdr">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="height">
+        <xs:attributeGroup ref="attrs.int"
+          use="required" />
+      </xs:element>
+      <xs:element ref="width" />
+      <xs:element ref="num_components" />
+      <xs:element ref="depth" />
+      <xs:element ref="compression" />
+      <xs:element ref="colour_unknown" />
+      <xs:element ref="ipr" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="colr">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="method" />
+      <xs:element ref="precedence" />
+      <xs:element ref="approx" />
+      <xs:element ref="colour" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="bpcc">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="depth"
+        maxOccurs="unbounded" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="pclr">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="num_entries" />
+      <xs:element ref="num_components" />
+      <xs:element ref="depth"
+        maxOccurs="unbounded" />
+      <xs:element ref="data"
+        maxOccurs="unbounded" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="cdef">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="num_entries" />
+      <xs:sequence maxOccurs="unbounded">
+        <xs:element ref="index" />
+        <xs:element ref="type" />
+        <xs:element ref="assoc" />
+      </xs:sequence>
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="res_">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="resc" minOccurs="0" />
+      <xs:element ref="resd" minOccurs="0" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="resd">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="vert_num" />
+      <xs:element ref="vert_den" />
+      <xs:element ref="hori_num" />
+      <xs:element ref="hori_den" />
+      <xs:element ref="vert_exp" />
+      <xs:element ref="hori_exp" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="resd">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="vert_num" />
+      <xs:element ref="vert_den" />
+      <xs:element ref="hori_num" />
+      <xs:element ref="hori_den" />
+      <xs:element ref="vert_exp" />
+      <xs:element ref="hori_exp" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+```
+
+```
+
+</xs:element>
+
+<xs:element name="uuid">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="id" />
+      <xs:element ref="data" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="uinf">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="ulst" />
+      <xs:element ref="url_" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="ulst">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="num entries" />
+      <xs:element ref="uuid" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="url ">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="location" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name=" xml ">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="text" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="jp2c">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="data" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<!-- part 1 content element -->
+
+<xs:element name="signature" type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+    use="required" />
+</xs:element>
+
+<xs:element name="brand" type="fourcc">
+  <xs:attributeGroup ref="attrs.4cc"
+    use="required" />
+</xs:element>
+
+<xs:element name="version" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="compatibility" type="fourcc">
+  <xs:attributeGroup ref="attrs.4cc"
+    use="required" />
+</xs:element>
+
+```
+
+```
+
+<xs:element name="width" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="num components"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="depth" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="compression"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="colour unknown"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="ipr" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="method" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="precedence" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="approx" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="colour" type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+    use="required" />
+</xs:element>
+
+<xs:element name="num_entries"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="depth" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="data" type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+    use="required" />
+</xs:element>
+
+<xs:element name="index" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="type" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="assoc" type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+    use="required" />
+</xs:element>
+
+<xs:element name="vert_num" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+```
+
+```
+
+<xs:element name="vert_den" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="hori_num" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="hori_den" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="vert_exp" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+```
+
+```
+
+<xs:element name="hori_exp" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="id" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="location" type="location">
+  <xs:attributeGroup ref="attrs.url"
+    use="required" />
+</xs:element>
+
+<xs:element name="text" type="xs:string">
+  <xs:attributeGroup ref="attrs.str"
+    use="required" />
+</xs:element>
+
+```
+
+#### A.3.3 Example of an XML schema for a JPEG 2000 Part 2 image (single/layered image)
+
+```
+
+<!-- jpxml part 2 root element -->
+<xs:element name="jpxml">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.root" />
+    <xs:sequence>
+      <xs:element ref="jp" />
+      <xs:element ref="ftyp" />
+      <xs:element ref="rreq" />
+      <xs:element ref="jp2h" />
+      <xs:element ref="jpch" minOccurs="0" />
+      <xs:element ref="jplh" minOccurs="0" />
+      <xs:element ref="dtbl" minOccurs="0" />
+      <xs:element ref="ftbl" minOccurs="0" />
+      <xs:element ref="jp2i" minOccurs="0" />
+      <xs:element ref="jp2c" minOccurs="0" />
+      <xs:element ref="mdat" minOccurs="0" />
+      <xs:element ref="comp" minOccurs="0" />
+      <xs:element ref="drep" minOccurs="0" />
+      <xs:element ref="roid" minOccurs="0" />
+      <xs:element ref="cref" minOccurs="0" />
+      <xs:element ref="asoc" minOccurs="0" />
+      <xs:element ref="bfil" minOccurs="0" />
+      <xs:element ref="chck" minOccurs="0" />
+      <xs:element ref="mp7b" minOccurs="0" />
+      <xs:element ref="free" minOccurs="0" />
+      <xs:element ref="xml" minOccurs="0" />
+      <xs:element ref="uuid" minOccurs="0" />
+      <xs:element ref="uinf" minOccurs="0" />
+      <xs:element ref="jclx" minOccurs="0" />
+      <xs:element ref="j2cx" minOccurs="0" />
+      <xs:element ref="grp" minOccurs="0" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<!-- part 1 box element -->
+...
+<!-- part 2 box element -->
+<xs:element name="rreq">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="length" />
+      <xs:element ref="fua_mask" />
+      <xs:element ref="dc_mask" />
+      <xs:element ref="num_std_flags" />
+      <xs:sequence maxOccurs="unbounded">
+        <xs:element ref="std_flag" />
+        <xs:element ref="std_mask" />
+      </xs:sequence>
+      <xs:element ref="num_vender_features" />
+      <xs:sequence maxOccurs="unbounded">
+        <xs:element ref="vender_feature" />
+        <xs:element ref="vender_mask" />
+      </xs:sequence>
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="dtbl">
+
+```
+
+```
+
+<xs:complexType>
+  <xs:attributeGroup ref="attrs.box"
+    use="required" />
+  <xs:sequence>
+    <xs:element ref="num_entries" />
+    <xs:sequence maxOccurs="unbounded">
+      <xs:element ref="location" />
+    </xs:sequence>
+  </xs:sequence>
+</xs:complexType>
+</xs:element>
+
+<xs:element name="ftbl">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence maxOccurs="unbounded">
+      <xs:element ref="flst" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="flst">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="num_entries" />
+      <xs:sequence maxOccurs="unbounded">
+        <xs:element ref="offset" />
+        <xs:element ref="length" />
+        <xs:element ref="data_reference" />
+      </xs:sequence>
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="cref">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="type" />
+      <xs:element ref="flst" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="jpch">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="lbl_" minOccurs="0" />
+      <xs:element ref="ihdr" />
+      <xs:element ref="bpcc" minOccurs="0" />
+      <xs:element ref="pclr" minOccurs="0" />
+      <xs:element ref="cmap" minOccurs="0" />
+      <xs:element ref="roid" minOccurs="0" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+```
+
+```
+
+<xs:element name="jplh">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="lbl" minOccurs="0" />
+      <xs:element ref="cgrp" minOccurs="0" />
+      <xs:element ref="opct" minOccurs="0" />
+      <xs:element ref="cdef" minOccurs="0" />
+      <xs:element ref="creq" minOccurs="0" />
+      <xs:element ref="res" minOccurs="0" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="colour">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.hex"
+      use="required" />
+    <xs:choice>
+      <xs:sequence>
+        <xs:element ref="enum_colour" />
+        <xs:element ref="enum_param" />
+      </xs:sequence>
+      <xs:sequence>
+        <xs:element ref="vender_colour" />
+        <xs:element ref="vendar_param" />
+      </xs:sequence>
+    </xs:choice>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="enum_param">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.hex"
+      use="required" />
+    <xs:choice>
+      <xs:sequence>
+        <xs:element ref="range_L" />
+        <xs:element ref="offset_L" />
+        <xs:element ref="range_a" />
+        <xs:element ref="offset_a" />
+        <xs:element ref="range_b" />
+        <xs:element ref="offset_b" />
+        <xs:element ref="illuminant" />
+      </xs:sequence>
+      <xs:sequence>
+        <xs:element ref="range_J" />
+        <xs:element ref="offset_J" />
+        <xs:element ref="range_a" />
+        <xs:element ref="offset_a" />
+        <xs:element ref="range_b" />
+        <xs:element ref="offset_b" />
+      </xs:sequence>
+    </xs:choice>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="cgrp">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence maxOccurs="unbounded">
+      <xs:element ref="colr" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="opct">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="type" />
+      <xs:element ref="num_entries" />
+      <xs:element ref="data" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="creg">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="hori_size" />
+      <xs:element ref="vert_size" />
+
+```
+
+```
+
+      <xs:element ref="cds_num" />
+      <xs:element ref="hori_resolution" />
+      <xs:element ref="vert_resolution" />
+      <xs:element ref="hori_offset" />
+      <xs:element ref="vert_offset" />
+      <xs:element ref="num_entries" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="free">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="data" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="comp">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="copt" />
+      <xs:sequence maxOccurs="unbounded">
+        <xs:element ref="inst" />
+      </xs:sequence>
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="copt">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="height" />
+      <xs:element ref="width" />
+      <xs:element ref="loop" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="inst">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="type" />
+      <xs:element ref="repeition" />
+      <xs:element ref="duration" />
+      <xs:element ref="instruction" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="instruction" type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+    use="required" />
+  <xs:sequence>
+    <xs:element ref="hori_offset" />
+    <xs:element ref="vert_offset" />
+    <xs:element ref="width" />
+    <xs:element ref="height" />
+    <xs:element ref="life" />
+    <xs:element ref="next_use" />
+    <xs:element ref="vert_crop_offset" />
+    <xs:element ref="hori_crop_offset" />
+    <xs:element ref="crop_width" />
+    <xs:element ref="crop_height" />
+  </xs:sequence>
+</xs:element>
+
+<xs:element name="nlst">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence maxOccurs="unbounded">
+      <xs:element ref="asoc_num" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="lbl" >
+  <xs:complexType>
+
+```
+
+```
+
+    <xs:attributeGroup ref="attrs.box"
+                      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="label" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="bfil">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+                      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="type" />
+      <xs:element ref="data" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="drep">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+                      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="gtso" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="gtso">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+                      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="profile" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="roid">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+                      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="num_entries" />
+      <xs:element ref="contained" />
+      <xs:element ref="type" />
+      <xs:element ref="priority" />
+      <xs:element ref="left" />
+      <xs:element ref="top" />
+      <xs:element ref="width" />
+      <xs:element ref="height" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="chck">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+                      use="required" />
+
+    <xs:sequence>
+
+```
+
+```
+
+      <xs:element ref="signature type" />
+      <xs:element ref="source type" />
+      <xs:element ref="offset" />
+      <xs:element ref="length" />
+      <xs:element ref="data" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="mp7b">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+                      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="data" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<!-- part 1 content element -->
+...
+<!-- part 3 content element -->
+<xs:element name="length"
+              type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="offset" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="data reference"
+              type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="enum_colour"
+              type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="enum_param" type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+                    use="required" />
+</xs:element>
+
+<xs:element name="vender colour"
+              type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="vendar_param" type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+                    use="required" />
+</xs:element>
+
+```
+
+#### A.3.4 Example of an XML schema for a JPEG 2000 Part 3 image (motion image)
+
+```
+
+<!-- jpxml part 3 root element -->
+<xs:element name="jpxml">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.root" />
+    <xs:sequence>
+      <xs:element ref="jp " />
+      <xs:element ref="ftyp" />
+      <xs:element ref="pdin" minOccurs="0" />
+      <xs:element ref="moov" />
+      <xs:element ref="mdat" minOccurs="0" />
+      <xs:element ref="moof" minOccurs="0" />
+      <xs:element ref="mfra" minOccurs="0" />
+      <xs:element ref="meta" minOccurs="0" />
+      <xs:element ref="meco" minOccurs="0" />
+      <xs:element ref="skip" minOccurs="0" />
+      <xs:element ref="free" minOccurs="0" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<!-- part 1 box element -->
+<!-- part 12 box element -->
+...
+<!-- part 3 box element -->
+
+```
+
+```
+
+<xs:element name="mid2">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+                      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="reserved" />
+      <xs:element ref="data_reference" />
+      <xs:element ref="predefined" />
+      <xs:element ref="reserved" />
+      <xs:element ref="predefined" />
+      <xs:element ref="width" />
+      <xs:element ref="height" />
+      <xs:element ref="hori resolution" />
+      <xs:element ref="vert resolution" />
+      <xs:element ref="reserved" />
+      <xs:element ref="predefined" />
+      <xs:element ref="name" />
+      <xs:element ref="depth" />
+      <xs:element ref="predefined" />
+      <xs:element ref="length" />
+      <xs:element ref="jp2h" />
+      <xs:element ref="fiel" minOccurs="0" />
+      <xs:element ref="jp2p" minOccurs="0" />
+      <xs:element ref="jp2x" minOccurs="0" />
+      <xs:element ref="jsub" minOccurs="0" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+```
+
+```
+
+    <xs:element ref="orfo" minOccurs="0" />
+  </xs:sequence>
+</xs:complexType>
+</xs:element>
+
+<xs:element name="fiel">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="field count" />
+      <xs:element ref="field_order" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="orfo">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="original_field_count" />
+      <xs:element ref="original field order" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="jp2p">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="version" />
+      <xs:element ref="flag" />
+      <xs:element ref="compatibility" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="jp2x">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="data" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="jsub">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="hori sub" />
+      <xs:element ref="vert sub" />
+      <xs:element ref="hori offset" />
+      <xs:element ref="vert offset" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="raw ">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="reserved" />
+      <xs:element ref="data_reference" />
+      <xs:element ref="reserved" />
+      <xs:element ref="channel_count" />
+      <xs:element ref="sample size" />
+      <xs:element ref="predefined" />
+      <xs:element ref="reserved" />
+      <xs:element ref="sample rate" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<!-- part 3 content element -->
+<xs:element name="reserved" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+```
+
+```
+
+<xs:element name="predefined"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="hori resolution"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="vert resolution"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="name" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="field_count"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="field order"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="original_field_count"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="original field order"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="version" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="flag" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="hori_sub" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="vert_sub" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="channel_count"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="sample size"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="sample rate"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+```
+
+#### A.3.5 Example of an XML schema for a JPEG 2000 Part 6 image (document image)
+
+```
+
+<!-- jpxml part 6 root element -->
+<xs:element name="jpxml">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.root" />
+    <xs:sequence>
+      <xs:element ref="jp_" />
+      <xs:element ref="ftyp" />
+      <xs:element ref="jp2h" minOccurs="0" />
+      <xs:element ref="mhdr" />
+      <xs:element ref="pcol" minOccurs="0" />
+      <xs:element ref="page" />
+      <xs:element ref="sdat" minOccurs="0" />
+      <xs:element ref="dtbl" minOccurs="0" />
+      <xs:element ref="ftbl" minOccurs="0" />
+      <xs:element ref="cref" minOccurs="0" />
+      <xs:element ref="jp2i" minOccurs="0" />
+      <xs:element ref="jp2c" minOccurs="0" />
+      <xs:element ref="_xml" minOccurs="0" />
+      <xs:element ref="uuid" minOccurs="0" />
+      <xs:element ref="uinf" minOccurs="0" />
+      <xs:element ref="free" minOccurs="0" />
+      <xs:element ref="htxb" minOccurs="0" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<!-- part 1 box element -->
+<!-- part 2 box element -->
+...
+<!-- part 6 box element -->
+<xs:element name="mhdr">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="num pages" />
+      <xs:element ref="profile" />
+      <xs:element ref="self_contained" />
+      <xs:element ref="offset" />
+      <xs:element ref="length" />
+      <xs:element ref="mask coder" />
+      <xs:element ref="image coder" />
+      <xs:element ref="ipr" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="pcol">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="lbl_"
+        minOccurs="0" />
+      <xs:element ref="meta"
+        minOccurs="0" />
+      <xs:element ref="pagt" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="ppcl">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="offset" />
+      <xs:element ref="length" />
+      <xs:element ref="data reference" />
+      <xs:element ref="index" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="pagt">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="num_entries" />
+      <xs:sequence maxOccurs="unbounded">
+        <xs:element ref="offset" />
+        <xs:element ref="length" />
+        <xs:element ref="data reference" />
+      </xs:sequence>
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+  <xs:element ref="data reference" />
+  <xs:element ref="flag" />
+</xs:sequence>
+</xs:sequence>
+</xs:complexType>
+</xs:element>
+
+<xs:element name="sdat">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="id" />
+      <xs:element ref="data" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="sref">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="id" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="page">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="phdr" />
+      <xs:element ref="ppcl"
+        minOccurs="0" />
+      <xs:element ref="res"
+        minOccurs="0" />
+      <xs:element ref="bclr"
+        minOccurs="0" />
+      <xs:element ref="meta"
+        minOccurs="0" />
+      <xs:element ref="lbl_"
+        minOccurs="0" />
+      <xs:element ref="lobj"
+        maxOccurs="unbounded" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="phdr">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="num lobjs" />
+      <xs:element ref="height" />
+      <xs:element ref="width" />
+      <xs:element ref="orientation" />
+      <xs:element ref="colour" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="lobj">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="ihdr" />
+      <xs:element ref="meta"
+        minOccurs="0" />
+      <xs:element ref="lbl"
+        minOccurs="0" />
+      <xs:element ref="objc"
+        maxOccurs="unbounded" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="lhdr">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+
+```
+
+```
+
+        use="required" />
+    <xs:sequence>
+        <xs:element ref="id" />
+        <xs:element ref="height" />
+        <xs:element ref="width" />
+        <xs:element ref="top" />
+        <xs:element ref="left" />
+        <xs:element ref="style" />
+    </xs:sequence>
+</xs:complexType>
+</xs:element>
+
+<xs:element name="objc">
+    <xs:complexType>
+        <xs:attributeGroup ref="attrs.box"
+            use="required" />
+
+        <xs:sequence>
+            <xs:element ref="ohdr" />
+            <xs:element ref="bclr"
+                minOccurs="0" />
+            <xs:element ref="meta"
+                minOccurs="0" />
+            <xs:element ref="lbl"
+                minOccurs="0" />
+            <xs:element ref="scal"
+                minOccurs="0" />
+            <xs:element ref="jp2h"
+                minOccurs="0" />
+        </xs:sequence>
+    </xs:complexType>
+</xs:element>
+
+<xs:element name="lhdr">
+    <xs:complexType>
+        <xs:attributeGroup ref="attrs.box"
+            use="required" />
+
+        <xs:sequence>
+            <xs:element ref="type" />
+            <xs:element ref="no_codestream" />
+            <xs:element ref="top" />
+            <xs:element ref="left" />
+            <xs:element ref="offset" />
+            <xs:element ref="length" />
+            <xs:element ref="data_reference" />
+        </xs:sequence>
+    </xs:complexType>
+</xs:element>
+
+<xs:element name="scal">
+    <xs:complexType>
+        <xs:attributeGroup ref="attrs.box"
+            use="required" />
+
+        <xs:sequence>
+            <xs:element ref="vert_num" />
+            <xs:element ref="vert_den" />
+            <xs:element ref="hori_num" />
+            <xs:element ref="hori_den" />
+        </xs:sequence>
+    </xs:complexType>
+</xs:element>
+
+<xs:element name="bclr">
+    <xs:complexType>
+        <xs:attributeGroup ref="attrs.box"
+            use="required" />
+
+        <xs:sequence>
+            <xs:element ref="bcvl" />
+            <xs:element ref="colr"
+                minOccurs="0" />
+            <xs:element ref="bpcc"
+                minOccurs="0" />
+        </xs:sequence>
+    </xs:complexType>
+</xs:element>
+
+<xs:element name="bcvl">
+    <xs:complexType>
+        <xs:attributeGroup ref="attrs.box"
+            use="required" />
+
+        <xs:sequence>
+            <xs:element ref="num_components" />
+            <xs:element ref="depth" />
+            <xs:element ref="data" />
+        </xs:sequence>
+    </xs:complexType>
+</xs:element>
+
+```
+
+```
+
+<xs:element name="htxb">
+    <xs:complexType>
+        <xs:attributeGroup ref="attrs.box"
+            use="required" />
+
+        <xs:sequence>
+            <xs:element ref="lbl"
+                minOccurs="0" />
+            <xs:sequence maxOccurs="unbounded">
+                <xs:choice>
+                    <xs:element ref="_xml" />
+                    <xs:element ref="uuid" />
+                </xs:choice>
+            </xs:sequence>
+        </xs:sequence>
+    </xs:complexType>
+</xs:element>
+
+<xs:element name="phtx">
+    <xs:complexType>
+        <xs:attributeGroup ref="attrs.box"
+            use="required" />
+
+        <xs:sequence>
+            <xs:element ref="type" />
+            <xs:element ref="flst" />
+            <xs:element ref="lbl"
+                minOccurs="0" />
+        </xs:sequence>
+    </xs:complexType>
+</xs:element>
+
+<!-- part 1 content element -->
+<!-- part 2 content element -->
+...
+<!-- part 6 content element -->
+<xs:element name="profile" type="xs:integer">
+    <xs:attributeGroup ref="attrs.int"
+        use="required" />
+</xs:element>
+
+<xs:element name="self contained"
+    type="xs:integer">
+    <xs:attributeGroup ref="attrs.int"
+        use="required" />
+</xs:element>
+
+<xs:element name="offset" type="xs:integer">
+    <xs:attributeGroup ref="attrs.int"
+        use="required" />
+</xs:element>
+
+<xs:element name="mask coder" type="xs:integer">
+    <xs:attributeGroup ref="attrs.int"
+        use="required" />
+</xs:element>
+
+<xs:element name="image coder" type="xs:integer">
+    <xs:attributeGroup ref="attrs.int"
+        use="required" />
+</xs:element>
+
+<xs:element name="flag" type="hexbyte">
+    <xs:attributeGroup ref="attrs.hex"
+        use="required" />
+</xs:element>
+
+<xs:element name="num_lobjs"
+    type="xs:integer">
+    <xs:attributeGroup ref="attrs.int"
+        use="required" />
+</xs:element>
+
+<xs:element name="orientation"
+    type="xs:integer">
+    <xs:attributeGroup ref="attrs.int"
+        use="required" />
+</xs:element>
+
+<xs:element name="top" type="xs:integer">
+    <xs:attributeGroup ref="attrs.int"
+        use="required" />
+</xs:element>
+
+<xs:element name="left" type="xs:integer">
+    <xs:attributeGroup ref="attrs.int"
+        use="required" />
+</xs:element>
+
+```
+
+```
+
+<xs:element name="style" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+```
+
+```
+
+<xs:element name="no codestream"
+type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+```
+
+#### A.3.6 Example of an XML schema for a JPEG 2000 Part 8 image (security)
+
+```
+
+<!-- part 1 box element -->
+<!-- part 8 box element -->
+<xs:element name="gpri">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+                      use="required" />
+    <xs:sequence>
+      <xs:element ref="type_flag" />
+      <xs:element ref="size_flag" />
+      <xs:element ref="location_flag" />
+      <xs:element ref="reserved" />
+      <xs:choice>
+        <xs:sequence>
+          <xs:element ref="num_entries" />
+          <xs:sequence maxOccurs="unbounded">
+            <xs:element ref="offset_size" />
+            <xs:element ref="box_length" />
+            <xs:element ref="box_type" />
+            <xs:element ref="box_ext_length" />
+            <xs:element ref="offset" />
+          </xs:sequence>
+        </xs:sequence>
+        <xs:sequence>
+          <xs:element ref="total_length" />
+          <xs:element ref="total_ext_length" />
+        </xs:sequence>
+      </xs:choice>
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<!-- part 12 box element -->
+<!-- followings need part 12 -->
+<xs:element name="schi">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+                      use="required" />
+    <xs:sequence>
+      <xs:element ref="type" />
+      <xs:choice>
+        <!-- for Decryption -->
+        <xs:sequence>
+          <xs:element ref="box_protected" />
+          <xs:choice>
+            <xs:element ref="bcip" />
+            <xs:element ref="scip" />
+          </xs:choice>
+          <xs:element ref="gran" />
+        </xs:sequence>
+        <!-- for Authentication -->
+        <xs:sequence>
+          <xs:element ref="auth" />
+          <xs:element ref="gran"
+                        minOccurs="0" />
+        </xs:sequence>
+      </xs:choice>
+      <xs:element ref="vall" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="bcip">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+                      use="required" />
+    <xs:sequence>
+      <xs:element ref="cipher_id" />
+      <xs:element ref="cipher_mode" />
+      <xs:element ref="padding_mode" />
+      <xs:element ref="size" />
+      <xs:element ref="keyt" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="scip">
+  <xs:complexType>
+
+```
+
+```
+
+    <xs:attributeGroup ref="attrs.box"
+                      use="required" />
+    <xs:sequence>
+      <xs:element ref="type" />
+      <xs:element ref="cipher_id" />
+      <xs:element ref="keyt" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="auth">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+                      use="required" />
+    <xs:sequence>
+      <xs:element ref="type" />
+      <xs:element ref="method_id" />
+      <xs:element ref="hash_id" />
+      <xs:element ref="size" />
+      <xs:element ref="keyt" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="keyt">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+                      use="required" />
+    <xs:sequence>
+      <xs:element ref="size" />
+      <xs:element ref="key_info" />
+      <xs:element ref="gran"
+                    minOccurs="0" />
+      <xs:element ref="vall" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="gran">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+                      use="required" />
+    <xs:sequence>
+      <xs:element ref="granularity" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="vall">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+                      use="required" />
+    <xs:sequence>
+      <xs:element ref="size" />
+      <xs:element ref="num_entries" />
+      <xs:element ref="count"
+                    maxOccurs="unbounded" />
+      <xs:element ref="value"
+                    maxOccurs="unbounded" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="ides">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+                      use="required" />
+    <xs:sequence>
+      <xs:element ref="num_entries" />
+      <xs:sequence maxOccurs="unbounded">
+        <xs:element ref="dest" />
+        <xs:element ref="item_id" />
+        <xs:element ref="desd" />
+      </xs:sequence>
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+```
+
+```
+
+<xs:element name="dest">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="type" />
+      <xs:element ref="version" />
+      <xs:element ref="location" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="vide">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="layer start" />
+      <xs:element ref="layer count" />
+      <xs:element ref="res_start" />
+      <xs:element ref="res_count" />
+      <xs:element ref="hori_offset" />
+      <xs:element ref="hori_lenght" />
+      <xs:element ref="vert_offset" />
+      <xs:element ref="vert_length" />
+      <xs:element ref="colour" />
+      <xs:element ref="time_start" />
+      <xs:element ref="time_length" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="j2ke">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="vide"
+        minOccurs="0" />
+      <xs:element ref="tile start" />
+      <xs:element ref="tile count" />
+      <xs:element ref="precinct_start" />
+      <xs:element ref="precinct count" />
+      <xs:element ref="j2k_packet_start" />
+      <xs:element ref="j2k packet count" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="icor">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="item id" />
+      <xs:element ref="desc id" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="port">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="resolution" />
+      <xs:element ref="layer" />
+      <xs:element ref="cropped width" />
+      <xs:element ref="cropped_height" />
+      <xs:sequence minOccurs="0" >
+        <xs:element ref="startx" />
+        <xs:element ref="srarty" />
+      </xs:sequence>
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="attr">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="resolution" />
+      <xs:element ref="layer" />
+      <xs:element ref="cropped width" />
+      <xs:element ref="cropped_height" />
+      <xs:sequence minOccurs="0" >
+
+```
+
+```
+
+      <xs:element ref="startx" />
+      <xs:element ref="srarty" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="scs">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="reserved" />
+      <xs:element ref="data reference" />
+      <xs:element ref="predefined" />
+      <xs:element ref="reserved" />
+      <xs:element ref="predefined" />
+      <xs:element ref="width" />
+      <xs:element ref="height" />
+      <xs:element ref="hori_resolution" />
+      <xs:element ref="vert_resolution" />
+      <xs:element ref="reserved" />
+      <xs:element ref="predefined" />
+      <xs:element ref="name" />
+      <xs:element ref="depth" />
+      <xs:element ref="predefined" />
+      <xs:element ref="clap" minOccurs="0" />
+      <xs:element ref="pasp" minOccurs="0" />
+      <xs:element ref="resolution" />
+      <xs:element ref="layer" />
+      <xs:element ref="cropped width" />
+      <xs:element ref="cropped_height" />
+      <xs:sequence minOccurs="0" >
+        <xs:element ref="startx" />
+        <xs:element ref="srarty" />
+      </xs:sequence>
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="dces">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="reserved" />
+      <xs:element ref="data_reference" />
+      <xs:element ref="predefined" />
+      <xs:element ref="reserved" />
+      <xs:element ref="predefined" />
+      <xs:element ref="width" />
+      <xs:element ref="height" />
+      <xs:element ref="hori_resolution" />
+      <xs:element ref="vert_resolution" />
+      <xs:element ref="reserved" />
+      <xs:element ref="predefined" />
+      <xs:element ref="name" />
+      <xs:element ref="depth" />
+      <xs:element ref="predefined" />
+      <xs:element ref="clap" minOccurs="0" />
+      <xs:element ref="pasp" minOccurs="0" />
+      <xs:element ref="resolution" />
+      <xs:element ref="layer" />
+      <xs:element ref="cropped width" />
+      <xs:element ref="cropped_height" />
+      <xs:sequence minOccurs="0" >
+        <xs:element ref="startx" />
+        <xs:element ref="srarty" />
+      </xs:sequence>
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<!-- part 1 content element -->
+<!-- part 8 content element -->
+<xs:element ref="type_flag" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element ref="size_flag" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element ref="location_flag"
+  type="xs:integer">
+
+```
+
+```
+
+<xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element ref="reserved" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element ref="offset_size"
+type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element ref="box length" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element ref="box type" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element ref="box ext length"
+type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element ref="offset" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element ref="total length"
+type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element ref="total ext length"
+type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<!-- part 12 box element -->
+<!-- followings need part 12 -->
+<xs:element ref="box protected"
+type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element ref="cipher id" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element ref="method id" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element ref="hash id" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element ref="cipher mode"
+type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element ref="padding mode"
+type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element ref="size" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+```
+
+```
+
+<xs:element ref="key info" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element ref="granularity"
+type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element ref="num entries" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element ref="count" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element ref="value" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element ref="item id" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element ref="layer start"
+type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element ref="layer_count"
+type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element ref="res start" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element ref="res count" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element ref="hori offset"
+type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element ref="hori lenght"
+type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element ref="vert offset"
+type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element ref="vert length"
+type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element ref="time_start" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element ref="time_length"
+type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+```
+
+```
+
+</xs:element>
+
+<xs:element ref="tile start" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element ref="tile count" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element ref="precinct start"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element ref="precinct count"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element ref="j2k_packet_start"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element ref="j2k_packet count"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element ref="item_id" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element ref="desc_id" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element ref="reserved" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+```
+
+```
+
+<xs:element ref="predefined" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element ref="hori_resolution"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element ref="vert_resolution"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element ref="resolution" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element ref="layer" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element ref="cropped width"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element ref="cropped height"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element ref="startx" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element ref="srarty" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+```
+
+#### A.3.7 Example of an XML schema for a JPEG 2000 Part 12 image (motion image)
+
+```
+
+<!-- part 12 box element -->
+<xs:element name="mdat">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="data" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="free">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="data" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="skip">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="data" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="pdin">
+  <xs:complexType>
+
+```
+
+```
+
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="version" />
+      <xs:element ref="flag" />
+      <xs:sequence maxOccurs="unbounded">
+        <xs:element ref="rate" />
+        <xs:element ref="inital_delay" />
+      </xs:sequence>
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="moov">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="mvhd" />
+      <xs:element ref="trak"
+        maxOccurs="unbounded" />
+      <xs:element ref="mvex" minOccurs="0" />
+      <xs:element ref="udta" minOccurs="0" />
+      <xs:element ref="meta" minOccurs="0" />
+      <xs:element ref="meco" minOccurs="0" />
+      <xs:element ref="ipmc" minOccurs="0" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="mvhd">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+
+```
+
+```
+
+        use="required" />
+    <xs:sequence>
+        <xs:element ref="version" />
+        <xs:element ref="flag" />
+        <xs:element ref="creation_time" />
+        <xs:element ref="modification time" />
+        <xs:element ref="time_scale" />
+        <xs:element ref="duration" />
+        <xs:element ref="rate" />
+        <xs:element ref="volume" />
+        <xs:element ref="reserved" />
+        <xs:element ref="matrix" />
+        <xs:element ref="predefined" />
+        <xs:element ref="next track id" />
+    </xs:sequence>
+</xs:complexType>
+</xs:element>
+
+<xs:element name="trak">
+    <xs:complexType>
+        <xs:attributeGroup ref="attrs.box"
+            use="required" />
+
+        <xs:sequence>
+            <xs:element ref="tkhd" />
+            <xs:element ref="mdia" />
+            <xs:element ref="tref" minOccurs="0" />
+            <xs:element ref="edts" minOccurs="0" />
+            <xs:element ref="udta" minOccurs="0" />
+            <xs:element ref="meta" minOccurs="0" />
+            <xs:element ref="meco" minOccurs="0" />
+        </xs:sequence>
+    </xs:complexType>
+</xs:element>
+
+<xs:element name="tkhd">
+    <xs:complexType>
+        <xs:attributeGroup ref="attrs.box"
+            use="required" />
+
+        <xs:sequence>
+            <xs:element ref="version" />
+            <xs:element ref="flag" />
+            <xs:element ref="creation_time" />
+            <xs:element ref="modification time" />
+            <xs:element ref="track_id" />
+            <xs:element ref="reserved" />
+            <xs:element ref="duration" />
+            <xs:element ref="reserved" />
+            <xs:element ref="layer" />
+            <xs:element ref="alternate_group" />
+            <xs:element ref="volume" />
+            <xs:element ref="reserved" />
+            <xs:element ref="matrix" />
+            <xs:element ref="width" />
+            <xs:element ref="height" />
+        </xs:sequence>
+    </xs:complexType>
+</xs:element>
+
+<xs:element name="tref">
+    <xs:complexType>
+        <xs:attributeGroup ref="attrs.box"
+            use="required" />
+
+        <xs:sequence>
+            <xs:choice>
+                <xs:element ref="hint" />
+                <xs:element ref="cdsc" />
+                <xs:element ref="hind" />
+            </xs:choice>
+        </xs:sequence>
+    </xs:complexType>
+</xs:element>
+
+<xs:element name="hint">
+    <xs:complexType>
+        <xs:attributeGroup ref="attrs.box"
+            use="required" />
+
+        <xs:sequence>
+            <xs:element ref="track id" />
+        </xs:sequence>
+    </xs:complexType>
+</xs:element>
+
+<xs:element name="cdsc">
+    <xs:complexType>
+        <xs:attributeGroup ref="attrs.box"
+            use="required" />
+
+    <xs:sequence>
+
+```
+
+```
+
+        <xs:element ref="track id" />
+    </xs:sequence>
+</xs:complexType>
+</xs:element>
+
+<xs:element name="hind">
+    <xs:complexType>
+        <xs:attributeGroup ref="attrs.box"
+            use="required" />
+
+        <xs:sequence>
+            <xs:element ref="track id" />
+        </xs:sequence>
+    </xs:complexType>
+</xs:element>
+
+<xs:element name="mdia">
+    <xs:complexType>
+        <xs:attributeGroup ref="attrs.box"
+            use="required" />
+
+        <xs:sequence>
+            <xs:element ref="mdhd" />
+            <xs:element ref="hdlr" />
+            <xs:element ref="minf" />
+        </xs:sequence>
+    </xs:complexType>
+</xs:element>
+
+<xs:element name="mdhd">
+    <xs:complexType>
+        <xs:attributeGroup ref="attrs.box"
+            use="required" />
+
+        <xs:sequence>
+            <xs:element ref="version" />
+            <xs:element ref="flag" />
+            <xs:element ref="creation time" />
+            <xs:element ref="modification time" />
+            <xs:element ref="time_scale" />
+            <xs:element ref="duration" />
+            <xs:element ref="language" />
+            <xs:element ref="predefined" />
+        </xs:sequence>
+    </xs:complexType>
+</xs:element>
+
+<xs:element name="hdlr">
+    <xs:complexType>
+        <xs:attributeGroup ref="attrs.box"
+            use="required" />
+
+        <xs:sequence>
+            <xs:element ref="version" />
+            <xs:element ref="flag" />
+            <xs:element ref="predefined" />
+            <xs:element ref="hdlr type" />
+            <xs:element ref="reserved" />
+            <xs:element ref="name" />
+        </xs:sequence>
+    </xs:complexType>
+</xs:element>
+
+<xs:element name="minf">
+    <xs:complexType>
+        <xs:attributeGroup ref="attrs.box"
+            use="required" />
+
+        <xs:sequence>
+            <xs:choice>
+                <xs:element ref="vmhd" />
+                <xs:element ref="smhd" />
+                <xs:element ref="hmhd" />
+                <xs:element ref="nmhd" />
+            </xs:choice>
+            <xs:element ref="stbl" />
+            <xs:element ref="dinf" />
+        </xs:sequence>
+    </xs:complexType>
+</xs:element>
+
+<xs:element name="vmhd">
+    <xs:complexType>
+        <xs:attributeGroup ref="attrs.box"
+            use="required" />
+
+        <xs:sequence>
+            <xs:element ref="version" />
+            <xs:element ref="flag" />
+            <xs:element ref="graphic_mode" />
+            <xs:element ref="op code" />
+        </xs:sequence>
+    </xs:complexType>
+
+```
+
+```
+
+</xs:element>
+
+<xs:element name="smhd">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="version" />
+      <xs:element ref="flag" />
+      <xs:element ref="balance" />
+      <xs:element ref="reserved" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="hmhd">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="version" />
+      <xs:element ref="flag" />
+      <xs:element ref="max pdu size" />
+      <xs:element ref="avg pdu size" />
+      <xs:element ref="max bitrate" />
+      <xs:element ref="avg bitrate" />
+      <xs:element ref="reserved" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="stbl">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="stsd" />
+      <xs:element ref="stdp" minOccurs="0" />
+      <xs:element ref="ctts" />
+      <xs:element ref="stss" minOccurs="0" />
+      <xs:element ref="stsh" minOccurs="0" />
+      <xs:element ref="sdtg" minOccurs="0" />
+      <xs:choice>
+        <xs:element ref="stsz" />
+        <xs:element ref="stz2" />
+      </xs:choice>
+      <xs:element ref="stsc" />
+      <xs:choice>
+        <xs:element ref="stco" />
+        <xs:element ref="co64" />
+      </xs:choice>
+      <xs:element ref="padb" minOccurs="0" />
+      <xs:element ref="subs" minOccurs="0" />
+      <xs:element ref="sbgp" minOccurs="0"
+        maxOccurs="unbounded" />
+      <xs:element ref="sgpd" minOccurs="0"
+        maxOccurs="unbounded" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="btrt">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="buffer size" />
+      <xs:element ref="max bitrate" />
+      <xs:element ref="avg_bitrate" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="metx">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="reserved" />
+      <xs:element ref="data reference" />
+      <xs:element ref="content_encoding" />
+      <xs:element ref="namespace" />
+      <xs:element ref="location" />
+      <xs:element ref="btrt"
+        minOccurs="0"
+        maxOccurs="unbounded" />
+    </xs:sequence>
+
+```
+
+```
+
+</xs:complexType>
+</xs:element>
+
+<xs:element name="mett">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="reserved" />
+      <xs:element ref="data reference" />
+      <xs:element ref="content_encoding" />
+      <xs:element ref="mime_format" />
+      <xs:element ref="btrt"
+        minOccurs="0"
+        maxOccurs="unbounded" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="pasp">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="hori_spacing" />
+      <xs:element ref="vert_spacing" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="clap">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="width_num" />
+      <xs:element ref="width_den" />
+      <xs:element ref="height_num" />
+      <xs:element ref="height_den" />
+      <xs:element ref="hori_offset_num" />
+      <xs:element ref="hori_offset_den" />
+      <xs:element ref="vert_offset_num" />
+      <xs:element ref="vert_offset_den" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="stsd">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="version" />
+      <xs:element ref="flag" />
+      <xs:element ref="num_entries" />
+      <xs:sequence maxOccurs="unbounded">
+        <xs:element ref="mjp2" />
+        <xs:element ref="raw" />
+        <xs:element ref="twos" />
+      </xs:sequence>
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="VideoCoding4CC">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="reserved" />
+      <xs:element ref="data_reference" />
+      <xs:element ref="predefined" />
+      <xs:element ref="reserved" />
+      <xs:element ref="predefined" />
+      <xs:element ref="width" />
+      <xs:element ref="height" />
+      <xs:element ref="hori_resolution" />
+      <xs:element ref="vert_resolution" />
+      <xs:element ref="reserved" />
+      <xs:element ref="predefined" />
+      <xs:element ref="name" />
+      <xs:element ref="depth" />
+      <xs:element ref="predefined" />
+      <xs:element ref="clap" minOccurs="0" />
+      <xs:element ref="pasp" minOccurs="0" />
+    </xs:sequence>
+  </xs:complexType>
+
+```
+
+```
+
+</xs:element>
+
+<xs:element name="AudioCoding4CC">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="reserved" />
+      <xs:element ref="data reference" />
+      <xs:element ref="reserved" />
+      <xs:element ref="channel count" />
+      <xs:element ref="sample_size" />
+      <xs:element ref="predefined" />
+      <xs:element ref="reserved" />
+      <xs:element ref="sample_rate" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="stdp">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="version" />
+      <xs:element ref="flag" />
+      <xs:element ref="priority" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="stts">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="version" />
+      <xs:element ref="flag" />
+      <xs:element ref="num_entries" />
+      <xs:sequence maxOccurs="unbounded">
+        <xs:element ref="sample count" />
+        <xs:element ref="sample_delta" />
+      </xs:sequence>
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="ctts">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="version" />
+      <xs:element ref="flag" />
+      <xs:element ref="num_entries" />
+      <xs:sequence maxOccurs="unbounded">
+        <xs:element ref="sample count" />
+        <xs:element ref="sample offset" />
+      </xs:sequence>
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="stss">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="version" />
+      <xs:element ref="flag" />
+      <xs:element ref="num_entries" />
+      <xs:sequence maxOccurs="unbounded">
+        <xs:element ref="sample number" />
+      </xs:sequence>
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="stsh">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="version" />
+      <xs:element ref="flag" />
+      <xs:element ref="num_entries" />
+      <xs:sequence maxOccurs="unbounded">
+
+```
+
+```
+
+      <xs:element
+        ref="shadowed sample number"
+      />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="sdtp">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="version" />
+      <xs:element ref="flag" />
+      <xs:sequence maxOccurs="unbounded">
+        <xs:element ref="reserved" />
+        <xs:element ref="sample depends on" />
+        <xs:element ref="sample_is_depends_on"
+      />
+      <xs:element ref="sample_has_redundancy"
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="edts">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="elst"
+        minOccurs="0" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="elst">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="version" />
+      <xs:element ref="flag" />
+      <xs:element ref="num_entries" />
+      <xs:sequence maxOccurs="unbounded">
+        <xs:element ref="duration" />
+        <xs:element ref="media time" />
+        <xs:element ref="media rate integer" />
+        <xs:element ref="media_rate_fraction" />
+      </xs:sequence>
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="dinf">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:choice>
+        <xs:element ref="dref" />
+        <xs:element ref="url " />
+        <xs:element ref="urn_ " />
+      </xs:choice>
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="url ">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="version" />
+      <xs:element ref="flag" />
+      <xs:element ref="location" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="urn_">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+```
+
+```
+
+    <xs:sequence>
+      <xs:element ref="version" />
+      <xs:element ref="flag" />
+      <xs:element ref="name" />
+      <xs:element ref="location" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="dref">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="version" />
+      <xs:element ref="flag" />
+      <xs:element ref="num_entries" />
+      <xs:sequence maxOccurs="unbounded">
+        <xs:choice>
+          <xs:element ref="url" />
+          <xs:element ref="urn" />
+        </xs:choice>
+      </xs:sequence>
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="stsz">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="version" />
+      <xs:element ref="flag" />
+      <xs:element ref="sample_size" />
+      <xs:element ref="num_entries" />
+      <xs:element ref="entry_size"
+        minOccurs="0"
+        maxOccurs="unbounded" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="stz2">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="version" />
+      <xs:element ref="flag" />
+      <xs:element ref="reserved" />
+      <xs:element ref="field_size" />
+      <xs:element ref="num_entries" />
+      <xs:element ref="entry_size"
+        minOccurs="0"
+        maxOccurs="unbounded" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="stsc">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="version" />
+      <xs:element ref="flag" />
+      <xs:element ref="num_entries" />
+      <xs:sequence maxOccurs="unbounded">
+        <xs:element ref="first_chunk" />
+        <xs:element ref="sample_per_chunk" />
+        <xs:element ref="description_index" />
+      </xs:sequence>
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="stco">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="version" />
+      <xs:element ref="flag" />
+      <xs:element ref="num_entries" />
+      <xs:element ref="chunk_offset"
+        maxOccurs="unbounded" />
+
+```
+
+```
+
+  </xs:sequence>
+</xs:complexType>
+</xs:element>
+
+<xs:element name="co64">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="version" />
+      <xs:element ref="flag" />
+      <xs:element ref="num_entries" />
+      <xs:element ref="chunk_offset"
+        maxOccurs="unbounded" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="padb">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="version" />
+      <xs:element ref="flag" />
+      <xs:element ref="pad1" />
+      <xs:element ref="pad2" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="subs">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="version" />
+      <xs:element ref="flag" />
+      <xs:element ref="num_entries" />
+      <xs:sequence maxOccurs="unbounded">
+        <xs:element ref="sample_delta" />
+        <xs:element ref="num_subsample" />
+        <xs:sequence maxOccurs="unbounded">
+          <xs:element ref="subsample_size" />
+          <xs:element ref="subsample_priority" />
+        </xs:sequence>
+      </xs:sequence>
+    </xs:sequence>
+    <xs:element ref="discardable" />
+    <xs:element ref="reserved" />
+  </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="mvex">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="mehd"
+        minOccurs="0" />
+      <xs:element ref="trex" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="mehd">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="version" />
+      <xs:element ref="flag" />
+      <xs:element ref="duration" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="trex">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="version" />
+      <xs:element ref="flag" />
+      <xs:element ref="track_id" />
+      <xs:element ref="sample_index" />
+
+```
+
+```
+
+    <xs:element ref="sample duration" />
+    <xs:element ref="sample size" />
+    <xs:element ref="sample flags" />
+  </xs:sequence>
+</xs:complexType>
+</xs:element>
+
+<xs:element name="moof">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="mfhd" />
+      <xs:element ref="traf" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="mfhd">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="version" />
+      <xs:element ref="flag" />
+      <xs:element ref="sequence number" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="traf">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="tfhd" />
+      <xs:element ref="traf" minOccurs="0" />
+      <xs:element ref="trun" minOccurs="0" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="tfhd">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="version" />
+      <xs:element ref="flag" />
+      <xs:element ref="track id" />
+      <xs:element ref="base delta offset" />
+      <xs:element ref="sample index" />
+      <xs:element ref="sample duration" />
+      <xs:element ref="sample size" />
+      <xs:element ref="sample flags" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="trun">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="version" />
+      <xs:element ref="flag" />
+      <xs:element ref="track id" />
+      <xs:element ref="num entries" />
+      <xs:element ref="delta_offset" />
+      <xs:element ref="first sample flags" />
+      <xs:sequence minOccurs="0" maxOccurs="unbounded">
+        <xs:element ref="sample duration" />
+        <xs:element ref="sample size" />
+        <xs:element ref="sample_flags" />
+        <xs:element ref="sample time offset" />
+      </xs:sequence>
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="mfra">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="tfra" />
+
+```
+
+```
+
+    <xs:element ref="mfro" />
+  </xs:sequence>
+</xs:complexType>
+</xs:element>
+
+<xs:element name="tfra">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="version" />
+      <xs:element ref="flag" />
+      <xs:element ref="track id" />
+      <xs:element ref="reserved" />
+      <xs:element ref="traf_index_size" />
+      <xs:element ref="trun_index_size" />
+      <xs:element ref="sample_index_size" />
+      <xs:element ref="num entries" />
+      <xs:sequence maxOccurs="unbounded">
+        <xs:element ref="time" />
+        <xs:element ref="moof offset" />
+        <xs:element ref="traf_index" />
+        <xs:element ref="trun_index" />
+        <xs:element ref="sample index" />
+      </xs:sequence>
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="sbgp">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="version" />
+      <xs:element ref="flag" />
+      <xs:element ref="type" />
+      <xs:element ref="num entries" />
+      <xs:sequence maxOccurs="unbounded">
+        <xs:element ref="sample count" />
+        <xs:element
+          ref="group_description_index" />
+      </xs:sequence>
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="sbgd">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="version" />
+      <xs:element ref="flag" />
+      <xs:element ref="type" />
+      <xs:element ref="default length" />
+      <xs:element ref="num entries" />
+      <xs:sequence maxOccurs="unbounded">
+        <xs:element ref="description_length" />
+        <xs:element ref="data" />
+      </xs:sequence>
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="udta">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="cpirt"
+        minOccurs="0"
+        maxOccurs="unbounded" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="cpirt">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="version" />
+      <xs:element ref="flag" />
+      <xs:element ref="language" />
+      <xs:element ref="notice" />
+    </xs:sequence>
+
+```
+
+```
+
+</xs:complexType>
+</xs:element>
+
+<xs:element name="tsel">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="version" />
+      <xs:element ref="flag" />
+      <xs:element ref="switch_group" />
+      <xs:element ref="attributes" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="meta">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="version" />
+      <xs:element ref="flag" />
+      <xs:choice minOccurs="0">
+        <xs:element ref="xml" />
+        <xs:element ref="bxml" />
+      </xs:choice>
+      <xs:sequence>
+        <xs:element ref="iloc" minOccurs="0"
+/>
+      </xs:sequence>
+    </xs:complexType>
+  </xs:element>
+
+  <xs:element ref="pitm" minOccurs="0" />
+  <xs:element ref="ipro" minOccurs="0" />
+  <xs:element ref="iinf" minOccurs="0" />
+  <xs:element ref="ipmc" minOccurs="0" />
+  <xs:element ref="fiim" minOccurs="0" />
+  <xs:element ref="hdlr" minOccurs="0" />
+  <xs:element ref="dinf" minOccurs="0" />
+</xs:sequence>
+</xs:complexType>
+</xs:element>
+
+<xs:element name="xml">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="version" />
+      <xs:element ref="flag" />
+      <xs:element ref="text" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="bxml">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="version" />
+      <xs:element ref="flag" />
+      <xs:element ref="data" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="iloc">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="version" />
+      <xs:element ref="flag" />
+      <xs:choice>
+        <xs:sequence>
+          <xs:element ref="offset_size" />
+          <xs:element ref="length_size" />
+          <xs:element ref="base_offset_size"
+/>
+        </xs:sequence>
+        <xs:element ref="reserved" />
+        <xs:element ref="num_entries" />
+        <xs:sequence maxOccurs="unbounded">
+          <xs:element ref="item_id" />
+          <xs:element ref="data_reference"
+/>
+        </xs:sequence>
+      </xs:choice>
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+  <xs:element ref="base_offset" />
+  <xs:element ref="sample_index" />
+
+```
+
+```
+
+    <xs:element ref="num_extents" />
+    <xs:sequence maxOccurs="unbounded">
+      <xs:element ref="extent_offset" />
+      <xs:element ref="extent_length" />
+    </xs:sequence>
+  </xs:sequence>
+</xs:sequence>
+<xs:element ref="item_id" />
+</xs:choice>
+</xs:sequence>
+</xs:complexType>
+</xs:element>
+
+<xs:element name="ipro">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="version" />
+      <xs:element ref="flag" />
+      <xs:element ref="num_entries" />
+      <xs:sequence maxOccurs="unbounded">
+        <xs:element ref="sinf" />
+      </xs:sequence>
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="infe">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="version" />
+      <xs:element ref="flag" />
+      <xs:element ref="item_id" />
+      <xs:element ref="item_protection_index" />
+      <xs:element ref="item_name" />
+      <xs:element ref="content_type" />
+      <xs:element ref="content_encoding" />
+      <xs:element ref="type" />
+      <xs:element ref="data" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="iinf">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="version" />
+      <xs:element ref="flag" />
+      <xs:element ref="num_entries" />
+      <xs:element ref="infe"
+        maxOccurs="unbounded" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="meco">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="mere"
+        minOccurs="0"
+        maxOccurs="unbounded" />
+      <xs:element ref="meta"
+        maxOccurs="unbounded" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="sinf">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="firma" />
+      <xs:element ref="imif" minOccurs="0" />
+      <xs:element ref="schm" minOccurs="0" />
+      <xs:element ref="schi" minOccurs="0" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+```
+
+```
+
+<xs:element name="frma">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="data format" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="imif">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="version" />
+      <xs:element ref="flag" />
+      <xs:element ref="metabox relation" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="ipmc">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="version" />
+      <xs:element ref="flag" />
+      <xs:element ref="tool list" />
+      <xs:element ref="num entries" />
+      <xs:element ref="metabox_relaion" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="schm">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="version" />
+      <xs:element ref="flag" />
+      <xs:element ref="schema_type" />
+      <xs:element ref="schema version" />
+      <xs:element ref="schema location" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="schi">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="fpar" />
+      <xs:element ref="fecr" minOccurs="0" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="fiin">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="version" />
+      <xs:element ref="flag" />
+      <xs:element ref="num_entries" />
+      <xs:element ref="paen"
+        minOccurs="unbounded" />
+      <xs:element ref="segr" minOccurs="0" />
+      <xs:element ref="gitn" minOccurs="0" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="fpar">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="version" />
+      <xs:element ref="flag" />
+      <xs:element ref="packet payload size" />
+      <xs:element ref="reserved" />
+      <xs:element ref="FEC_encoding_id" />
+
+```
+
+```
+
+    <xs:element ref="FEC instance id" />
+    <xs:element ref="max source block length"
+  />
+    <xs:element ref="symbol length" />
+    <xs:element ref="max_num_symbols" />
+    <xs:element ref="scheme specific info" />
+    <xs:element ref="num_entries" />
+    <xs:sequence minOccurs="unbounded">
+      <xs:element ref="block count" />
+      <xs:element ref="block_size" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="segr">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="version" />
+      <xs:element ref="flag" />
+      <xs:element ref="num entries" />
+      <xs:sequence minOccurs="unbounded">
+        <xs:element ref="num_group_ids" />
+        <xs:sequence minOccurs="unbounded">
+          <xs:element ref="group_id" />
+        </xs:sequence>
+      </xs:sequence>
+      <xs:element ref="num hint track ids" />
+      <xs:sequence minOccurs="unbounded">
+        <xs:element ref="hint track id" />
+      </xs:sequence>
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="gitn">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="version" />
+      <xs:element ref="flag" />
+      <xs:element ref="num entries" />
+      <xs:sequence minOccurs="unbounded">
+        <xs:element ref="group_id" />
+        <xs:element ref="group name" />
+      </xs:sequence>
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="rtp_">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="reserved" />
+      <xs:element ref="data reference" />
+      <xs:element ref="track version" />
+      <xs:element ref="compatible version" />
+      <xs:element ref="max packet size" />
+      <xs:sequence minOccurs="unbounded">
+        <xs:element ref="tims" />
+        <xs:element ref="tsro"
+          minOccurs="0" />
+        <xs:element ref="snro"
+          minOccurs="0" />
+      </xs:sequence>
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="srtp">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="reserved" />
+      <xs:element ref="data reference" />
+      <xs:element ref="track version" />
+      <xs:element ref="compatible version" />
+      <xs:element ref="max_packet_size" />
+      <xs:sequence minOccurs="unbounded">
+        <xs:element ref="tims" />
+        <xs:element ref="srpp" />
+
+```
+
+```
+
+    <xs:element ref="tsro" minOccurs="0"
+  />
+    <xs:element ref="snro" minOccurs="0"
+  />
+  </xs:sequence>
+</xs:sequence>
+</xs:complexType>
+</xs:element>
+
+<xs:element name="tims">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="time_scale" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="tsro">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="offset" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="snro">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="offset" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="srpp">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="version" />
+      <xs:element ref="flag" />
+      <xs:element ref="encryption_rtp" />
+      <xs:element ref="encryption_rtcp" />
+      <xs:element ref="integrity_rtp" />
+      <xs:element ref="integrity_rtcp" />
+      <xs:element ref="schm" />
+      <xs:element ref="schi"
+        minOccurs="0" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="rtpo">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="offset" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="hinti">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:choice>
+        <xs:element ref="rtp_" />
+        <xs:element ref="sdp" />
+      </xs:choice>
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="rtp_">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="format" />
+      <xs:element ref="text" />
+
+```
+
+```
+
+  </xs:sequence>
+</xs:complexType>
+</xs:element>
+
+<xs:element name="sdp_">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="text" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="hinf">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="trpy" minOccurs="0" />
+      <xs:element ref="nump" minOccurs="0" />
+      <xs:element ref="tpyl" minOccurs="0" />
+      <xs:element ref="totl" minOccurs="0" />
+      <xs:element ref="npck" minOccurs="0" />
+      <xs:element ref="tpay" minOccurs="0" />
+      <xs:element ref="maxr" minOccurs="0"
+        maxOccurs="unbounded" />
+      <xs:element ref="dmed" minOccurs="0" />
+      <xs:element ref="dimmm" minOccurs="0" />
+      <xs:element ref="drep" minOccurs="0" />
+      <xs:element ref="tmin" minOccurs="0" />
+      <xs:element ref="tmax" minOccurs="0" />
+      <xs:element ref="pmax" minOccurs="0" />
+      <xs:element ref="dmax" minOccurs="0" />
+      <xs:element ref="payt" minOccurs="0" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="trpy">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="bytes sent" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="tryl">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="bytes sent" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="dmed">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="bytes sent" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="dima">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="bytes sent" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="drep">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="bytes sent" />
+    </xs:sequence>
+  </xs:complexType>
+
+```
+
+```
+
+</xs:element>
+
+<xs:element name="totl">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="bytes sent" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="tpay">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="bytes sent" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="nump">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="packets sent" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="npack">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="packets sent" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="tmin">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="time" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="tmax">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="time" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="dmax">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="time" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="pmax">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="bytes sent" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="maxr">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+
+```
+
+```
+
+      <xs:element ref="period" />
+      <xs:element ref="bytes sent" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="hnti">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="payload_id" />
+      <xs:element ref="count" />
+      <xs:element ref="rtmpmap" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="fdp ">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="reserved" />
+      <xs:element ref="data reference" />
+      <xs:element ref="track version" />
+      <xs:element ref="compatible_version" />
+      <xs:element ref="partition entry id" />
+      <xs:element ref="FEC overhead" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="fdsa">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="fdpa"
+        maxOccurs="unbounded" />
+      <xs:element ref="extr"
+        minOccurs="0" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="fdpa">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="header" />
+      <xs:element ref="extension size" />
+      <xs:element ref="extension" />
+      <xs:element ref="packet size" />
+      <xs:element ref="packet" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="extr">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.box"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="data" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<!-- part 12 content element -->
+
+<xs:element name="matrix">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.hexbyte"
+      use="required" />
+
+    <xs:sequence minOccurs="9" maxOccurs="9">
+      <xs:element ref="cell" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="cell" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+```
+
+```
+
+<xs:element name="version" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="flag" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="rate" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="data" type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+    use="required" />
+</xs:element>
+
+<xs:element name="data reference"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="data_format"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+  <xs:element name="inital_delay"
+type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="creation time"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="modification_time"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="time scale"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="duration"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="volume" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="reserved" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="predefined"
+type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="next track id"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="track_id"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+
+```
+
+```
+
+</xs:element>
+
+<xs:element name="layer" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="alternate group"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="width" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="height" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="language"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="hdlr type"
+type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="name" type="xs:string">
+  <xs:attributeGroup ref="attrs.str"
+    use="required" />
+</xs:element>
+
+<xs:element name="balance" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="max pdu size"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="avg_pdu_size"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="max bitrate"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="avg_bitrate"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="buffer size"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="content_encoding"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="namespace" type="xs:string">
+  <xs:attributeGroup ref="attrs.str"
+    use="required" />
+</xs:element>
+
+<xs:element name="location" type="xs:string">
+
+```
+
+```
+
+    <xs:attributeGroup ref="attrs.str"
+                      use="required" />
+</xs:element>
+
+<xs:element name="mine_format"
+             type="xs:string">
+  <xs:attributeGroup ref="attrs.str"
+                    use="required" />
+</xs:element>
+
+<xs:element name="hori_spacing"
+             type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="vert_spacing"
+             type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="width_num"
+             type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="width_den"
+             type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="height_num"
+             type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="height_den"
+             type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="hori_offset_num"
+             type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="hori_offset_den"
+             type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="vert_offset_num"
+             type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="vert_offset_den"
+             type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="hori_resolution"
+             type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="vert_resolution"
+             type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="depth" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+```
+
+```
+
+<xs:element name="channel count"
+             type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="sample_size"
+             type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="sample rate"
+             type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="priority" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="sample delta"
+             type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="num_entries"
+             type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="sample count"
+             type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="sample_offset"
+             type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="sample number"
+             type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="shadowed_sample_number"
+             type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="sync sample number"
+             type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="sample_depends_on"
+             type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="sample is depends on"
+             type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="sample has redundancy"
+             type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="media_time"
+             type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+
+```
+
+```
+
+</xs:element>
+
+<xs:element name="media rate integer"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="media rate fraction"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="field_size"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="first chunk"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="sample per chunk"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="description index"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="chunk_offset"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="pad1" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="pad2" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="num subsample"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="subsample size"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="subsample priority"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="discardable"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="sample_index"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="sample duration"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+
+```
+
+```
+
+    use="required" />
+</xs:element>
+
+<xs:element name="sample flags"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="sequence_number"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="base delta offset"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="delta_offset"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="first sample flags"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="sample time offset"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="traf index size"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="trun index size"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="sample_index_size"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="moof offset"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="traf_index"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="trun index"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="type" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="group_description_index"
+  type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="type" type="xs:integer">
+
+```
+
+```
+
+<xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="default_length"
+              type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="description_length"
+              type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="language" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="notice" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="switch_group"
+              type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="attributes"
+              type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="offset_size"
+              type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="length_size"
+              type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="base offset size"
+              type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="item id" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="base offset"
+              type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="sample index"
+              type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="num_extents"
+              type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="extent offset"
+              type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="extent_length"
+              type="xs:integer">
+
+```
+
+```
+
+<xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="item_protection_index"
+              type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="item name"
+              type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="content_type"
+              type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="content encoding"
+              type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="metabox relation"
+              type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="tool list" type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+                    use="required" />
+</xs:element>
+
+<xs:element name="metabox relation"
+              type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+                    use="required" />
+</xs:element>
+
+<xs:element name="schema type"
+              type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="schema_version"
+              type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="schema location"
+              type="xs:string">
+  <xs:attributeGroup ref="attrs.str"
+                    use="required" />
+</xs:element>
+
+<xs:element name="packet_payload_size"
+              type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="FEC encoding id"
+              type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="FEC_instance_id"
+              type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="max source block length"
+              type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+```
+
+```
+
+<xs:element name="symbol length"
+    type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+      use="required" />
+</xs:element>
+
+<xs:element name="max_num_symbols"
+    type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+      use="required" />
+</xs:element>
+
+<xs:element name="scheme specific info"
+    type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+      use="required" />
+</xs:element>
+
+<xs:element name="block count"
+    type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+      use="required" />
+</xs:element>
+
+<xs:element name="block_size"
+    type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+      use="required" />
+</xs:element>
+
+<xs:element name="num group ids"
+    type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+      use="required" />
+</xs:element>
+
+<xs:element name="num_hint_track_ids"
+    type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+      use="required" />
+</xs:element>
+
+<xs:element name="hint track id"
+    type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+      use="required" />
+</xs:element>
+
+<xs:element name="group_id"
+    type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+      use="required" />
+</xs:element>
+
+<xs:element name="group name"
+    type="xs:string">
+  <xs:attributeGroup ref="attrs.str"
+      use="required" />
+</xs:element>
+
+<xs:element name="track version"
+    type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+      use="required" />
+</xs:element>
+
+<xs:element name="compatible version"
+    type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+      use="required" />
+</xs:element>
+
+<xs:element name="max packet size"
+    type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+      use="required" />
+</xs:element>
+
+<xs:element name="max_packet_size"
+    type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+      use="required" />
+</xs:element>
+
+<xs:element name="offset" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+      use="required" />
+
+```
+
+```
+
+</xs:element>
+
+<xs:element name="encryption rtp"
+    type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+      use="required" />
+</xs:element>
+
+<xs:element name="encryption rtcp"
+    type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+      use="required" />
+</xs:element>
+
+<xs:element name="integrity rtp"
+    type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+      use="required" />
+</xs:element>
+
+<xs:element name="integrity rtcp"
+    type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+      use="required" />
+</xs:element>
+
+<xs:element name="offset" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+      use="required" />
+</xs:element>
+
+<xs:element name="format" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+      use="required" />
+</xs:element>
+
+<xs:element name="text" type="xs:string">
+  <xs:attributeGroup ref="attrs.str"
+      use="required" />
+</xs:element>
+
+<xs:element name="bytes_sent"
+    type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+      use="required" />
+</xs:element>
+
+<xs:element name="packets sent"
+    type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+      use="required" />
+</xs:element>
+
+<xs:element name="time" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+      use="required" />
+</xs:element>
+
+<xs:element name="period" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+      use="required" />
+</xs:element>
+
+<xs:element name="bytes_sent"
+    type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+      use="required" />
+</xs:element>
+
+<xs:element name="payload id"
+    type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+      use="required" />
+</xs:element>
+
+<xs:element name="count" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+      use="required" />
+</xs:element>
+
+<xs:element name="rtpmap" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+      use="required" />
+</xs:element>
+
+<xs:element name="partition entry id"
+    type="xs:integer">
+
+```
+
+```
+
+    <xs:attributeGroup ref="attrs.int"
+                      use="required" />
+  </xs:element>
+
+  <xs:element name="FEC_overhead"
+              type="xs:integer">
+    <xs:attributeGroup ref="attrs.int"
+                      use="required" />
+  </xs:element>
+
+  <xs:element name="header"
+              type="xs:integer">
+    <xs:attributeGroup ref="attrs.int"
+                      use="required" />
+  </xs:element>
+
+  <xs:element name="extension_size"
+              type="xs:integer">
+    <xs:attributeGroup ref="attrs.int"
+                      use="required" />
+
+```
+
+```
+
+  </xs:element>
+
+  <xs:element name="extension"
+              type="hexbyte">
+    <xs:attributeGroup ref="attrs.hex"
+                      use="required" />
+  </xs:element>
+
+  <xs:element name="packet size"
+              type="xs:integer">
+    <xs:attributeGroup ref="attrs.int"
+                      use="required" />
+  </xs:element>
+
+  <xs:element name="packet" type="hexbyte">
+    <xs:attributeGroup ref="attrs.hex"
+                      use="required" />
+  </xs:element>
+
+```
+
+# Annex B
+
+## JPXML elements for codestream marker segments
+
+(This annex forms an integral part of this Recommendation | International Standard.)
+
+### B.1 Introduction
+
+This annex provides the predefined marker element name, content element names, and length and type attributes for the JPEG 2000 family codestream. The marker element appearance and structure shall be in conformity with Rec. ITU-T T.800 | ISO/IEC 15444-1, Rec. ITU-T T.801 | ISO/IEC 15444-2, Rec. ITU-T T.807 | ISO/IEC 15444-8, Rec. ITU-T T.809 | ISO/IEC 15444-10 and Rec. ITU-T T.810 | ISO/IEC 15444-11.
+
+### B.2 JPEG 2000 codestream marker element definitions
+
+This subclause includes many tables of the marker's content element definitions, and these tables define the content element name, the content data length in byte, and the content data type. The JPXML data types are described in 7.5. Some tables define the sub-content element names of a defined content element, and some marker or content elements have content element definitions of two or more types. For more detailed information of the meaning and structure of this marker segment content, see each Recommendation | International Standard cited in clause B.1.
+
+#### B.2.1 JPEG 2000 Part 1 marker elements
+
+The JPEG 2000 part 1 marker elements shall be used as the element names described in Table B.1. These marker content element names are defined in Tables B.2 to B.19.
+
+Table B.1 – JPEG 2000 Part 1 markers
+
+| Marker name                                      | Element name | Code   | Size         | Main header            | Tile-part header                       |
+|--------------------------------------------------|--------------|--------|--------------|------------------------|----------------------------------------|
+| <b>Delimiting markers and marker segments</b>    |              |        |              |                        |                                        |
+| Start of codestream                              | SOC          | 0xFF4F | 2            | required <sup>a</sup>  | not allowed                            |
+| Start of tile-part                               | SOT          | 0xFF90 | 12           | not allowed            | required                               |
+| Start of data                                    | SOD          | 0xFF93 | 2            | not allowed            | last marker                            |
+| End of codestream                                | EOC          | 0xFFD9 | 2            | not allowed            | not allowed                            |
+| <b>Fixed information marker segments</b>         |              |        |              |                        |                                        |
+| Image and tile size                              | SIZ          | 0xFF51 | 43 to 49,192 | required               | not allowed                            |
+| <b>Functional marker segments</b>                |              |        |              |                        |                                        |
+| Coding style default                             | COD          | 0xFF52 | 14 to 47     | required               | optional                               |
+| Coding style component                           | COC          | 0xFF53 | 11 to 45     | optional               | optional                               |
+| Region-of-interest                               | RGN          | 0xFF5E | 7 to 8       | optional               | optional                               |
+| Quantization default                             | QCD          | 0xFF5C | 6 to 199     | required               | optional                               |
+| Quantization component                           | QCC          | 0xFF5D | 7 to 201     | optional               | optional                               |
+| Progression order change                         | POC          | 0xFF5F | 11 to 65,537 | optional               | optional                               |
+| <b>Pointer marker segments</b>                   |              |        |              |                        |                                        |
+| Tile-part lengths                                | TLM          | 0xFF55 | 8 to 65,537  | optional               | not allowed                            |
+| Packet length, main header                       | PLM          | 0xFF57 | 6 to 65,537  | optional               | not allowed                            |
+| Packet length, tile-part header                  | PLT          | 0xFF58 | 6 to 65,537  | not allowed            | optional                               |
+| Packed packet headers, main header               | PPM          | 0xFF60 | 9 to 65,537  | optional               | not allowed                            |
+| Packed packet headers, tile-part header          | PPT          | 0xFF61 | 6 to 65,537  | not allowed            | optional                               |
+| <b>In-bit-stream markers and marker segments</b> |              |        |              |                        |                                        |
+| Start of packet                                  | SOP          | 0xFF91 | 6            | not allowed            | not allowed<br>optional in-bitstream   |
+| End of packet header                             | EPH          | 0xFF92 | 2            | optional<br>inside PPM | optional inside PPT<br>or in-bitstream |
+| <b>Informational marker segments</b>             |              |        |              |                        |                                        |
+| Component registration                           | CRG          | 0xFF63 | 8 to 65,536  | optional               | not allowed                            |
+| Comment                                          | COM          | 0xFF64 | 7 to 65,537  | optional               | optional                               |
+
+**Table B.2 – Content element names for SOT**
+
+| content | length | type    | loop |
+|---------|--------|---------|------|
+| Isot    | 2      | integer |      |
+| Psot    | 4      | integer |      |
+| TPsot   | 1      | integer |      |
+| TNsot   | 1      | integer |      |
+
+**Table B.3 – Content element names for SIZ**
+
+| content | length | type    | loop |
+|---------|--------|---------|------|
+| Rsiz    | 2      | integer |      |
+| Xsiz    | 4      | integer |      |
+| Ysiz    | 4      | integer |      |
+| OXsiz   | 4      | integer |      |
+| OYsiz   | 4      | integer |      |
+| XTsiz   | 4      | integer |      |
+| YTsiz   | 4      | integer |      |
+| XTOsiz  | 4      | integer |      |
+| YTOsiz  | 4      | integer |      |
+| Csiz    | 2      | integer |      |
+| Ssiz    | 1      | integer | ]    |
+| XRsiz   | 1      | integer |      |
+| YRsiz   | 1      | integer |      |
+
+**Table B.4 – Content element names for COD**
+
+| content | length | type    | loop |
+|---------|--------|---------|------|
+| Scod    | 1      | hexbyte |      |
+| SGcod   | 4      | hexbyte |      |
+| SPcod   | 5 – 43 | hexbyte | ]    |
+
+**Table B.5 – Content element names for COC**
+
+| content | length | type    | loop |
+|---------|--------|---------|------|
+| Ccoc    | 1, 2   | hexbyte |      |
+| Scoc    | 1      | hexbyte |      |
+| SPcoc   | 5 – 43 | hexbyte | ]    |
+
+**Table B.6 – Content element names for SGcod**
+
+| SGcod       | length | type    | loop |
+|-------------|--------|---------|------|
+| progression | 1      | integer |      |
+| num_layers  | 2      | integer |      |
+| colour_conv | 1      | integer |      |
+
+**Table B.7 – Content element names for SPcod/SPcoc**
+
+| SPcod/SPcoc | length | type    | loop |
+|-------------|--------|---------|------|
+| num_levels  | 1      | integer |      |
+| xcb         | 1      | integer |      |
+| ycb         | 1      | integer |      |
+| style       | 1      | integer |      |
+| wavelet     | 1      | integer |      |
+| ppy         | 1/2    | integer | ]    |
+| ppx         | 1/2    | integer |      |
+
+**Table B.8 – Content element names for RGN**
+
+| content | length | type    | loop |
+|---------|--------|---------|------|
+| Crgn    | 1, 2   | integer |      |
+| Srgn    | 1      | integer |      |
+| SPrgn   | 1      | integer |      |
+
+**Table B.9 – Content element names for QCD**
+
+| content | length | type    | loop |
+|---------|--------|---------|------|
+| Sqcd    | 1      | integer |      |
+| SPqcd   | 1, 2   | integer | ]    |
+
+**Table B.10 – Content element names for QCC**
+
+| content | length | type    | loop |
+|---------|--------|---------|------|
+| Cqcc    | 1      | integer |      |
+| Sqcc    | 1      | integer |      |
+| SPqcc   | 1, 2   | integer | ]    |
+
+**Table B.11 – Content element names for POC**
+
+| content | length | type    | loop |
+|---------|--------|---------|------|
+| RSpoc   | 1      | integer | ]    |
+| CSpoc   | 1, 2   | integer |      |
+| LYEpoc  | 2      | integer |      |
+| REpoc   | 1      | integer |      |
+| CEpoc   | 1, 2   | integer |      |
+| Ppoc    | 1      | integer |      |
+
+**Table B.12 – Content element names for TLM**
+
+| content | length | type    | loop |
+|---------|--------|---------|------|
+| Ztlm    | 1      | integer |      |
+| Stlm    | 1      | integer |      |
+| Ttlm    | 0 – 2  | integer | ]    |
+| Ptlm    | 0 – 1  | integer |      |
+
+**Table B.13 – Content element names for PLM**
+
+| content | length   | type    | loop |
+|---------|----------|---------|------|
+| Zplm    | 1        | integer | ]    |
+| Nplm    | 1        | integer |      |
+| lplm    | 0-65,531 | integer |      |
+
+**Table B.14 – Content element names for PLT**
+
+| content | length   | type    | loop |
+|---------|----------|---------|------|
+| Zplt    | 1        | integer |      |
+| lplt    | 0-65,531 | integer | ]    |
+
+**Table B.15 – Content element names for PPM**
+
+| content | length   | type    | loop |
+|---------|----------|---------|------|
+| Zppm    | 1        | integer |      |
+| Nppm    | 2        | integer | ]    |
+| lppm    | 0-65,531 | integer |      |
+
+**Table B.16 – Content element names for PPT**
+
+| content | length   | type    | loop |
+|---------|----------|---------|------|
+| Zppt    | 1        | integer |      |
+| lppt    | 0-65,531 | integer | ]    |
+
+**Table B.17 – Content element names for SOP**
+
+| content | length | type    | loop |
+|---------|--------|---------|------|
+| Nsop    | 2      | integer |      |
+
+**Table B.18– Content element names for CRG**
+
+| content | length | type    | loop |
+|---------|--------|---------|------|
+| Xcrg    | 2      | integer | ]    |
+| Ycrg    | 2      | integer |      |
+
+**Table B.19 – Content element names for COM**
+
+| content | length   | type    | loop |
+|---------|----------|---------|------|
+| Rcom    | 1        | integer |      |
+| Ccom    | 1-65,531 | string  |      |
+
+#### **B.2.2 JPEG 2000 Part 2 marker elements**
+
+The extended and additional JPEG 2000 Part 2 marker elements shall be used as the element names described in Table B.20. These marker content element names are defined in Tables B.21 to B.38.
+
+**Table B.20 – JPEG 2000 Part 2 extended and additional markers**
+
+| Marker name                                  | Element name | Code   | Size         | Main header | Tile-part header |
+|----------------------------------------------|--------------|--------|--------------|-------------|------------------|
+| Start of tile-part (part 1 extended)         | SOT          | 0xFF90 | 14           | not allowed | required         |
+| Coding style default (part 1 extended)       | COD          | 0xFF52 | 14 to 47     | required    | optional         |
+| Coding style component (part 1 extended)     | COC          | 0xFF53 | 11 to 45     | optional    | optional         |
+| Region-of-interest (part 1 extended)         | RGN          | 0xFF5E | 7 to 24      | optional    | optional         |
+| Variable DC offset                           | DCO          | 0xFF70 | 7 to 32,772  | optional    | optional         |
+| Visual masking                               | VMS          | 0xFF71 | 11           | optional    | optional         |
+| Downsampling factor style                    | DFS          | 0xFF72 | 7 to 65,537  | optional    | optional         |
+| Arbitrary decomposition style                | ADS          | 0xFF73 | 5 to 65,537  | optional    | optional         |
+| Arbitrary transformation kernels             | ATK          | 0xFF79 | 11 to 65,537 | optional    | optional         |
+| Component bit depth                          | CBD          | 0xFF78 | 7 to 16,390  | optional    | optional         |
+| Multiple component transformation definition | MCT          | 0xFF74 | 8 to 65,537  | optional    | optional         |
+| Multiple component collection                | MCC          | 0xFF75 | 7 to 65,537  | optional    | optional         |
+| Multiple component transformation ordering   | MCO          | 0xFF77 | 3 to 260     | optional    | optional         |
+| Non-linearity point transformation           | NLT          | 0xFF76 | 14 to 65,537 | optional    | optional         |
+| Quantization default, precinct               | QPD          | 0xFF5A | 8 to 103     | optional    | optional         |
+| Quantization component, precinct             | QPC          | 0xFF5B | 7 to 201     | optional    | optional         |
+
+**Table B.21 – Content element names for SOT**
+
+| content     | length   | type           | loop |
+|-------------|----------|----------------|------|
+| Isot        | 2        | integer        |      |
+| <b>Psot</b> | <b>4</b> | <b>integer</b> |      |
+| TPsot       | 2        | integer        |      |
+| TNsot       | 2        | integer        |      |
+
+**Table B.22 – Content element names for COD**
+
+| content | length | type    | loop |
+|---------|--------|---------|------|
+| Scod    | 1      | hexbyte |      |
+| SGcod   | 4      | hexbyte |      |
+| SPcod   | 7 – 45 | hexbyte | ]    |
+
+**Table B.23 – Content element names for COC**
+
+| content | length | type    | loop |
+|---------|--------|---------|------|
+| Ccoc    | 1, 2   | hexbyte |      |
+| Scoc    | 1      | hexbyte |      |
+| SPcoc   | 7 – 45 | hexbyte | ]    |
+
+**Table B.24 – Content element names for Spcod/SPcoc**
+
+| SPcod/SPcoc | length | type    | loop |
+|-------------|--------|---------|------|
+| num_levels  | 1      | integer |      |
+| xcb         | 1      | integer |      |
+| ycb         | 1      | integer |      |
+| style       | 1      | integer |      |
+| wavelet     | 1      | integer |      |
+| sso         | 2      | integer |      |
+| ppy         | 1/2    | integer | ]    |
+| ppx         | 1/2    | integer |      |
+
+**Table B.25 – Content element names for RGN**
+
+| content | length | type    | loop |
+|---------|--------|---------|------|
+| Crgn    | 1, 2   | integer |      |
+| Srgn    | 1      | integer |      |
+| SPrgn   | 17     | integer |      |
+
+**Table B.26 – Content element names for SPrgn**
+
+| SPrgn | length | type    | loop |
+|-------|--------|---------|------|
+| shift | 1      | integer |      |
+| XArgn | 4      | integer |      |
+| YArgn | 4      | integer |      |
+| XBrgn | 4      | integer |      |
+| YBrgn | 4      | integer |      |
+
+**Table B.27 – Content element names for DCO**
+
+| content | length | type    | loop |
+|---------|--------|---------|------|
+| Sdco    | 1      | integer |      |
+| SPdco   | 1      | integer | □    |
+
+**Table B.28 – Content element names for VMS**
+
+| content | length | type    | loop |
+|---------|--------|---------|------|
+| Cvms    | 2      | integer |      |
+| Svm     | 1      | integer |      |
+| Wvms    | 1      | integer |      |
+| Rvm     | 1      | integer |      |
+| Avms    | 1      | integer |      |
+| Bvms    | 1      | integer |      |
+
+**Table B.29 – Content element names for DFS**
+
+| content | length   | type    | loop |
+|---------|----------|---------|------|
+| Sdfs    | 2        | integer |      |
+| Idfs    | 1        | integer |      |
+| Ddfs    | 0-65,530 | integer |      |
+
+**Table B.30 – Content element names for ADS**
+
+| content | length   | type    | loop |
+|---------|----------|---------|------|
+| Sads    | 1        | integer |      |
+| IOads   | 1        | integer |      |
+| DOads   | 0-65,530 | string  |      |
+| ISads   | 1        | integer |      |
+| DSads   | 0-65,530 | string  |      |
+
+**Table B.31 – Content element names for ATK**
+
+| content | length            | type    | loop   |
+|---------|-------------------|---------|--------|
+| Satk    | 2                 | integer |        |
+| Katk    | 0, 1, 2, 4, 8, 16 | integer |        |
+| Natk    | 1                 | integer |        |
+| Oatk    | 0, 1              | integer | ]<br>□ |
+| Eatk    | 0, 1              | string  |        |
+| Batk    | 0, 1, 2, 4, 8, 16 | integer |        |
+| LCatk   | 1                 | integer |        |
+| Aatk    | 1, 2, 4, 8, 16    | integer |        |
+
+**Table B.32 – Content element names for CBD**
+
+| content | length | type    | loop |
+|---------|--------|---------|------|
+| Ncbd    | 2      | integer |      |
+| BDcbd   | 1      | integer | □    |
+
+**Table B.33 – Content element names for MCO**
+
+| content | length | type    | loop |
+|---------|--------|---------|------|
+| Nmco    | 1      | integer |      |
+| Imco    | 1      | integer | □    |
+
+**Table B.34 – Content element names for NLT**
+
+| content | length | type    | loop |
+|---------|--------|---------|------|
+| Cnlt    | 2      | integer |      |
+| BDnlt   | 1      | integer |      |
+| Tnlt    | 1      | integer |      |
+| STnlt   | 1      | integer | □    |
+
+**Table B.35 – Content element names for QPD**
+
+| content | length | type    | loop |
+|---------|--------|---------|------|
+| PLqpd   | 2      | integer |      |
+| PPqpd   | 1, 2   | integer |      |
+| Sqpd    | 1      | integer |      |
+| SPqpd   | 1      | integer | □    |
+
+**Table B.36 – Content element names for QPC**
+
+| content | length | type    | loop |
+|---------|--------|---------|------|
+| Cqpc    | 1, 2   | integer |      |
+| PLqpc   | 2      | integer |      |
+| PPqpc   | 1, 2   | integer |      |
+| Sqpc    | 1      | integer |      |
+| SPqpc   | 1      | integer | □    |
+
+**Table B.37 – Content element names for MCT**
+
+| content | length | type    | loop |
+|---------|--------|---------|------|
+| Zmct    | 2      | integer |      |
+| Imct    | 2      | integer |      |
+| Ymct    | 0, 2   | integer |      |
+| SPmct   | 2      | integer | □    |
+
+**Table B.38 – Content element names for MCC**
+
+| content | length | type    | loop            |
+|---------|--------|---------|-----------------|
+| Zmcc    | 2      | integer |                 |
+| Imcc    | 1      | integer |                 |
+| Ymcc    | 0, 2   | integer |                 |
+| Qmcc    | 1      | integer |                 |
+| Xmcc    | 1      | integer |                 |
+| Nmcc    | 2      | integer | ]<br>□<br><br>□ |
+| Cmcc    | 1, 2   | integer |                 |
+| Mmcc    | 2      | integer |                 |
+| Wmcc    | 1, 2   | integer |                 |
+| Tmcc    | 3      | integer |                 |
+| Omcc    | 4      | integer |                 |
+
+#### B.2.3 JPEG 2000 Part 8 marker elements
+
+The extended and additional JPEG 2000 Part 8 marker elements shall be used as the element names described in Table B.39. These marker content element names are defined in Tables B.40 to B.55.
+
+**Table B.39 – JPEG 2000 Part 8 additional marker**
+
+| Marker name                   | Element name | Code   | Size        | Main header | Tile-part header                     |
+|-------------------------------|--------------|--------|-------------|-------------|--------------------------------------|
+| Main security marker          | SEC          | 0xFF65 | 4 to 65,537 | optional    | optional                             |
+| In-codestream security marker | INSEC        | 0xFF94 | 4 to 65,537 | not allowed | not allowed<br>optional in-bitstream |
+
+**Table B.40 – Content element names for SEC**
+
+| content | length | type    | loop |
+|---------|--------|---------|------|
+| Zsec    | 8 -    | integer |      |
+| Psec    | 0, 7 - | hexbyte |      |
+| Tool    | 0 -    | hexbyte | □    |
+
+**Table B.41 – Content element names for INSEC**
+
+| content | length   | type    | loop |
+|---------|----------|---------|------|
+| index   | 8 -      | integer |      |
+| Rinsec  | 0, 7 -   | hexbyte |      |
+| APinsec | variable | hexbyte |      |
+
+**Table B.42 – Content element names for Psec**
+
+| Psec   | length | type    | loop |
+|--------|--------|---------|------|
+| Fpsec  | 1 -    | hexbyte |      |
+| Ntools | 1+n    | integer |      |
+| lmax   | 1+n    | integer |      |
+| Ptrlcp | 0, 4   | hexbyte |      |
+
+**Table B.43 – Content element names for Tool**
+
+| Tool   | length   | type    | loop |
+|--------|----------|---------|------|
+| type   | 1+n      | integer |      |
+| index  | 1+n      | integer |      |
+| IDtool | 1+n      | hexbyte |      |
+| length | 2+n      | integer |      |
+| ZOI    | variable | hexbyte |      |
+| LPid   | 2+n      | integer |      |
+| Pid    | variable | hexbyte |      |
+
+**Table B.44 – Content element names for IDtool**
+
+| IDtool<br>(Non-normative Tool) | length | type    | loop |
+|--------------------------------|--------|---------|------|
+| IDraid                         | 1+n    | integer |      |
+| IDransl                        | 1+n    | integer |      |
+| IDrans                         | 0, 4   | hexbyte |      |
+
+**Table B.45 – Content element names for ZOI**
+
+| ZOI   | length   | type    | loop |
+|-------|----------|---------|------|
+| NZzoi | 1+n      | integer |      |
+| Zone  | variable | hexbyte | □    |
+
+**Table B.46 – Content element names for Zone**
+
+| Zone  | length   | type    | loop |
+|-------|----------|---------|------|
+| DCzoi | variable | integer |      |
+| Pzoi  | variable | hexbyte | □    |
+
+**Table B.47 – Content element names for Pzoi**
+
+| Pzoi | length   | type    | loop |
+|------|----------|---------|------|
+| Mzoi | variable | hexbyte |      |
+| Nzoi | 0, 1+n   | integer |      |
+| lzoi | variable | hexbyte | □    |
+
+**Table B.48 – Content element names for Pid**
+
+| Pid<br>(Normative Tool) | length | type    | loop |
+|-------------------------|--------|---------|------|
+| NTid                    | 1+n    | integer |      |
+| NTdomain                | 1+n    | integer |      |
+| NTgranularity           | 3      | integer |      |
+| NTvalue                 | 0, 4   | hexbyte |      |
+
+**Table B.49 – Content element names for NTdomain**
+
+| NTdomain | length   | type    | loop |
+|----------|----------|---------|------|
+| PD       | variable | hexbyte |      |
+| Fpd      | variable | hexbyte |      |
+
+**Table B.50 – Content element names for NTgranularity**
+
+| NTgranularity | length | type    | loop |
+|---------------|--------|---------|------|
+| PD            | 2      | hexbyte |      |
+| GL            | 1      | hexbyte |      |
+
+**Table B.51 – Content element names for NTvalue**
+
+| NTvalue | length   | type    | loop |
+|---------|----------|---------|------|
+| Nv      | 2+n      | integer |      |
+| Sv      | 1+n      | integer |      |
+| data    | variable | hexbyte |      |
+
+**Table B.52 – Content element names for Tid**
+
+| Tid<br>(Decryption Template) | length   | type    | loop |
+|------------------------------|----------|---------|------|
+| MEdecry                      | 1+n      | hexbyte |      |
+| CTdecry                      | 2        | hexbyte |      |
+| CPdecry                      | variable | hexbyte |      |
+
+  
+
+| Tid<br>(Authentication Temp.) | length   | type    | loop |
+|-------------------------------|----------|---------|------|
+| MEauth                        | 1+n      | hexbyte |      |
+| Pauth                         | variable | hexbyte |      |
+
+  
+
+| Tid<br>(Hash Template) | length | type    | loop |
+|------------------------|--------|---------|------|
+| Hhash                  | 1      | hexbyte |      |
+| SIZhash                | 1      | integer |      |
+
+**Table B.53 – Content element names for CPdecry**
+
+| CPdecry<br>(Block cipher) | length   | type    | loop |
+|---------------------------|----------|---------|------|
+| Mbc                       | 3/4      | hexbyte |      |
+| Pbc                       | 1/4      | hexbyte |      |
+| SIZbc                     | 1        | integer |      |
+| KTntid                    | variable | hexbyte |      |
+
+  
+
+| CPdecry<br>(Stream cipher) | length   | type    | loop |
+|----------------------------|----------|---------|------|
+| KTntid                     | variable | hexbyte |      |
+
+  
+
+| CPdecry<br>(Asymmetric cipher) | length   | type    | loop |
+|--------------------------------|----------|---------|------|
+| KTntid                         | variable | hexbyte |      |
+
+#### **B.2.4 JPEG 2000 Part 10 marker elements**
+
+The extended and additional JPEG 2000 Part 10 marker elements shall be used as the element names described in Table B.56. These marker content element names are defined in Tables B.57 to B.65.
+
+**Table B.56 – JPEG 2000 Part 10 extended and additional markers**
+
+| Marker name                              | Element name | Code   | Size         | Main header | Tile-part header |
+|------------------------------------------|--------------|--------|--------------|-------------|------------------|
+| Coding style default (part 2 extended)   | COD          | 0xFF52 | 19 to 85     | required    | optional         |
+| Coding style component (part 2 extended) | COC          | 0xFF53 | 20 to 104    | optional    | optional         |
+| Region-of-interest (part 2 extended)     | RGN          | 0xFF5E | 7 to 32      | optional    | optional         |
+| Component registration (part 1 extended) | CRG          | 0xFF63 | 10 to 65,536 | optional    | not allowed      |
+| Additional dimension image and tile size | NSI          | 0xFF54 | 22 to 16,405 | required    | not allowed      |
+
+**Table B.57 – Content element names for NSI**
+
+| content | length | type    | loop |
+|---------|--------|---------|------|
+| Ndim    | 1      | integer |      |
+| Zsiz    | 4      | integer |      |
+| ZOsiz   | 4      | integer |      |
+| ZTsiz   | 5      | integer |      |
+| ZTOsiz  | 4      | integer |      |
+| ZRsiz   | 1      | integer | □    |
+
+**Table B.54 – Content element names for Pauth**
+
+| Pauth<br>(Hash-based Auth.) | length   | type    | loop |
+|-----------------------------|----------|---------|------|
+| Mhmac                       | 1        | hexbyte |      |
+| Hhmac                       | 1        | hexbyte |      |
+| KTntid                      | variable | hexbyte |      |
+| SIZhmac                     | 2        | integer |      |
+
+  
+
+| Pauth<br>(Cipher-based Auth.) | length   | type    | loop |
+|-------------------------------|----------|---------|------|
+| CACmac                        | 1        | hexbyte |      |
+| Ccmac                         | 1        | hexbyte |      |
+| KTntid                        | variable | hexbyte |      |
+| SIZcmac                       | 2        | integer |      |
+
+  
+
+| Pauth<br>(Digital Signature) | length   | type    | loop |
+|------------------------------|----------|---------|------|
+| Mds                          | 1        | hexbyte |      |
+| Hds                          | 1        | hexbyte |      |
+| KTntid                       | variable | hexbyte |      |
+| SIZds                        | 2        | integer |      |
+
+**Table B.55 – Content element names for KTntid**
+
+| KTntid      | length   | type    | loop |
+|-------------|----------|---------|------|
+| LKkt        | 2        | hexbyte |      |
+| KIDkt       | 1        | hexbyte |      |
+| granularity | 3        | hexbyte |      |
+| data        | variable | hexbyte |      |
+
+**Table B.58 – Content element names for COD**
+
+| content | length | type    | loop |
+|---------|--------|---------|------|
+| Scod    | 1      | hexbyte |      |
+| SGcod   | 4      | hexbyte |      |
+| SPcod   | 10-76  | hexbyte | □    |
+
+**Table B.59 – Content element names for COC**
+
+| content | length | type    | loop |
+|---------|--------|---------|------|
+| Ccoc    | 1, 2   | integer |      |
+| Scoc    | 1      | hexbyte |      |
+| SPcoc   | 10-94  | hexbyte | □    |
+
+**Table B.60 – Content element names for SPcod/SPcoc**
+
+| SPcod/SPcoc | length | type    | loop |
+|-------------|--------|---------|------|
+| num_xlevels | 1      | integer |      |
+| num_ylevels | 1      | integer |      |
+| num_zlevels | 1      | integer |      |
+| xcb         | 1      | integer |      |
+| ycb         | 1      | integer |      |
+| zcb         | 1      | integer |      |
+| style       | 1      | integer |      |
+| xkernel     | 1      | integer |      |
+| ykernel     | 1      | integer |      |
+| zkernel     | 1      | integer |      |
+| sso         | 2      | integer |      |
+| reserved    | 1/2    | –       |      |
+| ppz         | 1/2    | integer |      |
+| ppy         | 1/2    | integer |      |
+| ppx         | 1/2    | integer |      |
+
+**Table B.61 – Content element names for QCD**
+
+| content | length | type    | loop |
+|---------|--------|---------|------|
+| Sqcd    | 1      | integer |      |
+| SPqcd   | 1, 2   | integer | □    |
+
+**Table B.62 – Content element names for QCC**
+
+| content | length | type    | loop |
+|---------|--------|---------|------|
+| Cqcc    | 1      | integer |      |
+| Sqcc    | 1      | integer |      |
+| SPqcc   | 1, 2   | integer | □    |
+
+**Table B.63 – Content element names for RGn**
+
+| content | length | type    | loop |
+|---------|--------|---------|------|
+| Crgn    | 2      | integer |      |
+| Srgn    | 1      | integer |      |
+| SPrgn   | 25     | integer |      |
+
+**Table B.64 – Content element names for SPRgn**
+
+| SPrgn | length | type    | loop |
+|-------|--------|---------|------|
+| shift | 1      | integer |      |
+| XArgn | 4      | integer |      |
+| YArgn | 4      | integer |      |
+| ZArgn | 4      | integer |      |
+| XBrgn | 4      | integer |      |
+| YBrgn | 4      | integer |      |
+| ZBrgn | 4      | integer |      |
+
+**Table B.65 – Content element names for CRG**
+
+| content | length | type    | loop |
+|---------|--------|---------|------|
+| Xcrg    | 2      | integer |      |
+| Ycrg    | 2      | integer |      |
+| Zcrg    | 2      | integer |      |
+
+#### B.2.5 JPEG 2000 Part 11 marker elements
+
+The extended and additional JPEG 2000 Part 11 marker elements shall be used as the element names described in Table B.66. These marker content element names are defined in Tables B.67 to B.70.
+
+**Table B.66 – JPEG 2000 Part 11 additional markers**
+
+| Marker name                  | Element name | Code   | Size         | Main header | Tile-part header |
+|------------------------------|--------------|--------|--------------|-------------|------------------|
+| Error Protection Block       | EPB          | 0xFF66 | 13 to 65,537 | optional    | optional         |
+| Error Sensitivity Descriptor | ESD          | 0xFF67 | 6 to 65,537  | optional    | optional         |
+| Error Protection Capability  | EPC          | 0xFF68 | 11 to 65,537 | required    | optional         |
+| Residual Errors Descriptor   | RED          | 0xFF69 | 6 to 65,537  | optional    | optional         |
+
+**Table B.67 – Content element names for EPB**
+
+| content | length   | type    | loop |
+|---------|----------|---------|------|
+| Depb    | 1        | integer |      |
+| LDPEpb  | 4        | integer |      |
+| Pepb    | 4        | integer |      |
+| data    | 0-65,524 | hexbyte |      |
+
+**Table B.68 – Content element names for EPC**
+
+| content | length | type    | loop |
+|---------|--------|---------|------|
+| Pcrc    | 2      | integer |      |
+| DL      | 4      | integer |      |
+| Pepc    | 1      | integer |      |
+| id      | 2      | hexbyte |      |
+| Lid     | 2      | hexbyte |      |
+
+**Table B.69 – Content element names for ESD**
+
+| content | length   | type    | loop |
+|---------|----------|---------|------|
+| Cesd    | 1, 2     | integer |      |
+| Pesd    | 1        | integer |      |
+| data    | 0-65,531 | hexbyte |      |
+
+**Table B.70 – Content element names for RED**
+
+| content | length   | type    | loop |
+|---------|----------|---------|------|
+| Pred    | 1        | integer |      |
+| data    | 0-65,531 | hexbyte |      |
+
+### B.3 Examples of XML schemas
+
+The following examples are XML schemas for the marker elements of the JPEG 2000 family codestream.
+
+#### B.3.1 Example of an XML schema for a common header
+
+The following example is of common XML schemas for all marker types of JPEG 2000 family codestreams.
+
+```
+<?xml version="1.0" ?>
+<xs:schema xmlns:xs="http://www.iso.org/jpeg/2001/XMLSchema"
+  targetNamespace="http://www.iso.org/jpxml"
+  xmlns="http://www.iso.org/jpxml">
+
+  <xs:attributeGroup name="attrs.marker">
+    <xs:attribute name="length" type="xs:integer" use="required" />
+    <xs:attribute name="offset" type="xs:integer" use="optional" />
+    <xs:attribute name="type" use="required">
+      <xs:simpleType>
+        <xs:restriction base="xs:string">
+          <xs:enumeration value="marker" />
+        </xs:restriction>
+      </xs:simpleType>
+    </xs:attribute>
+  </xs:attributeGroup>
+
+  <xs:attributeGroup name="attrs.hex">
+    <xs:attribute name="length" type="xs:integer" use="required" />
+    <xs:attribute name="type" use="required">
+      <xs:simpleType>
+        <xs:restriction base="xs:string">
+          <xs:enumeration value="hexbyte" />
+        </xs:restriction>
+      </xs:simpleType>
+    </xs:attribute>
+  </xs:attributeGroup>
+
+  <xs:attributeGroup name="attrs.int">
+    <xs:attribute name="length" type="xs:integer" use="required" />
+    <xs:attribute name="type" use="required">
+      <xs:simpleType>
+        <xs:restriction base="xs:string">
+          <xs:enumeration value="integer" />
+        </xs:restriction>
+      </xs:simpleType>
+    </xs:attribute>
+  </xs:attributeGroup>
+
+  <xs:attributeGroup name="attrs.str">
+    <xs:attribute name="length" type="xs:integer" use="required" />
+    <xs:attribute name="type" use="required">
+      <xs:simpleType>
+        <xs:restriction base="xs:string">
+          <xs:enumeration value="string" />
+        </xs:restriction>
+      </xs:simpleType>
+    </xs:attribute>
+  </xs:attributeGroup>
+
+  <xs:attributeGroup name="attrs.url">
+    <xs:attribute name="length" type="xs:integer" use="required" />
+    <xs:attribute name="type" use="required">
+      <xs:simpleType>
+        <xs:restriction base="xs:string">
+          <xs:enumeration value="location" />
+        </xs:restriction>
+      </xs:simpleType>
+    </xs:attribute>
+  </xs:attributeGroup>
+
+  <xs:attributeGroup name="attrs.root">
+    <xs:attribute name="length" type="xs:integer" use="required" />
+    <xs:attribute name="name" type="xs:anyURL" use="optional" />
+  </xs:attributeGroup>
+
+  <!-- add following XML Schemas for the JPXML document. -->
+  ...
+
+</xs:schema>
+```
+
+#### **B.3.2 Example of an XML schema for a JPEG 2000 Part 1 codestream (single image)**
+
+```
+
+<!-- part 1 marker element -->
+<xs:element name="SOT">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.marker"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="Isot" />
+      <xs:element ref="Psot" />
+      <xs:element ref="TPsot" />
+      <xs:element ref="TNsot" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="SIZ">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.marker"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="Rsiz" />
+      <xs:element ref="Xsiz" />
+      <xs:element ref="Ysiz" />
+      <xs:element ref="OXsiz" />
+      <xs:element ref="OYsiz" />
+      <xs:element ref="XTsiz" />
+      <xs:element ref="YTsiz" />
+      <xs:element ref="XTOsiz" />
+      <xs:element ref="YTOsiz" />
+      <xs:sequence maxOccurs="unbounded">
+        <xs:element ref="Csiz" />
+        <xs:element ref="XRsiz" />
+        <xs:element ref="YRsiz" />
+      </xs:sequence>
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="COD">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.marker"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="Scod" />
+      <xs:element ref="SGcod" />
+      <xs:sequence maxOccurs="unbounded">
+        <xs:element ref="SPcod" />
+      </xs:sequence>
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="COC">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.marker"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="Ccoc" />
+      <xs:element ref="Scoc" />
+      <xs:sequence maxOccurs="unbounded">
+        <xs:element ref="SPcoc" />
+      </xs:sequence>
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="SGcod">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.hex"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="progression" />
+      <xs:element ref="num layers" />
+      <xs:element ref="colour conv" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="SPcod">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.hex"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="num_levels" />
+
+```
+
+```
+
+      <xs:element ref="xcb" />
+      <xs:element ref="ycb" />
+      <xs:element ref="style" />
+      <xs:element ref="wavelet" />
+      <xs:sequence maxOccurs="unbounded">
+        <xs:element ref="ppy" />
+        <xs:element ref="ppx" />
+      </xs:sequence>
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="SPcoc">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.hex"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="num_levels" />
+      <xs:element ref="xcb" />
+      <xs:element ref="ycb" />
+      <xs:element ref="style" />
+      <xs:element ref="wavelet" />
+      <xs:sequence maxOccurs="unbounded">
+        <xs:element ref="ppy" />
+        <xs:element ref="ppx" />
+      </xs:sequence>
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="RGN">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.marker"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="Crgn" />
+      <xs:element ref="Srgn" />
+      <xs:element ref="SPrgn" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="QCD">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.marker"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="Sqcd" />
+      <xs:sequence maxOccurs="unbounded">
+        <xs:element ref="SPqcd" />
+      </xs:sequence>
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="QCC">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.marker"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="Cqcc" />
+      <xs:element ref="Sqcc" />
+      <xs:sequence maxOccurs="unbounded">
+        <xs:element ref="SPqcc" />
+      </xs:sequence>
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="POC">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.marker"
+      use="required" />
+    <xs:sequence maxOccurs="unbounded">
+      <xs:element ref="RSpoc" />
+      <xs:element ref="CSpoc" />
+      <xs:element ref="LYEpoc" />
+      <xs:element ref="REpoc" />
+      <xs:element ref="CEpoc" />
+      <xs:element ref="Ppoc" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+```
+
+```
+
+<xs:element name="TLM">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.marker"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="Ztlm" />
+      <xs:element ref="Stlm" />
+      <xs:sequence maxOccurs="unbounded">
+        <xs:element ref="Ttlm" />
+        <xs:element ref="Ptlm" />
+      </xs:sequence>
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="PLM">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.marker"
+      use="required" />
+    <xs:sequence maxOccurs="unbounded">
+      <xs:element ref="Zplm" />
+      <xs:sequence maxOccurs="unbounded">
+        <xs:element ref="Nplm" />
+        <xs:element ref="Iplm" />
+      </xs:sequence>
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="PLT">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.marker"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="Zplt" />
+      <xs:sequence maxOccurs="unbounded">
+        <xs:element ref="Iplt" />
+      </xs:sequence>
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="PPM">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.marker"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="Zppm" />
+      <xs:sequence maxOccurs="unbounded">
+        <xs:element ref="Nppm" />
+        <xs:sequence maxOccurs="unbounded">
+          <xs:element ref="Ippm" />
+        </xs:sequence>
+      </xs:sequence>
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="PPT">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.marker"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="Zppt" />
+      <xs:sequence maxOccurs="unbounded">
+        <xs:element ref="Ippt" />
+      </xs:sequence>
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="SOP">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.marker"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="Nsop" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="CRG">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.marker"
+      use="required" />
+    <xs:sequence maxOccurs="unbounded">
+
+```
+
+```
+
+      <xs:element ref="Xcra" />
+      <xs:element ref="Ycrg" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="COM">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.marker"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="Rcom" />
+      <xs:element ref="Ccom" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<!-- part 1 marker element -->
+<xs:element name="Isot" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="Psot" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="TPsot" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="TNsot" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="Rsiz" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="Xsiz" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="Ysiz" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="OXsiz" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="OYsiz" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="XTsiz" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="YTsiz" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="XTOsiz" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="YTOsiz" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="Csiz" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+```
+
+
+
+```
+
+<xs:element name="RSpoc" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="CSpoc" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="LYEoc" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="REpoc" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="CEpoc" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="Ppoc" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="Ztlm" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="Stlm" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="Ttlm" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="Ptlm" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="Zplm" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="Nplm" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="Iplm" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+
+```
+
+```
+
+    use="required" />
+</xs:element>
+
+<xs:element name="Zplm" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="Iplm" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="Zppm" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="Nppm" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="Ippm" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="Zppt" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="Ippt" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="Nsop" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="Xcrg" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="Ycrg" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="Rcom" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="Ccom" type="xs:string">
+  <xs:attributeGroup ref="attrs.str"
+    use="required" />
+</xs:element>
+
+```
+
+#### B.3.3 Example of an XML schema for a JPEG 2000 Part 2 codestream (single/layered image)
+
+```
+
+<!-- part 1 marker element -->
+...
+<!-- part 2 marker element -->
+<xs:element name="SPcod">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.hex"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="num levels" />
+      <xs:element ref="xcb" />
+      <xs:element ref="ycb" />
+      <xs:element ref="style" />
+      <xs:element ref="wavelet" />
+      <xs:element ref="sso" />
+      <xs:sequence maxOccurs="unbounded">
+        <xs:element ref="ppy" />
+        <xs:element ref="ppx" />
+      </xs:sequence>
+    </xs:sequence>
+  </xs:complexType>
+
+```
+
+```
+
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="SPcoc">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.hex"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="num levels" />
+      <xs:element ref="xcb" />
+      <xs:element ref="ycb" />
+      <xs:element ref="style" />
+      <xs:element ref="wavelet" />
+      <xs:element ref="sso" />
+      <xs:sequence maxOccurs="unbounded">
+        <xs:element ref="ppy" />
+        <xs:element ref="ppx" />
+      </xs:sequence>
+    </xs:sequence>
+  </xs:complexType>
+</xs:complexType>
+
+```
+
+```
+
+</xs:element>
+
+<xs:element name="SPrgn">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.hex"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="shift" />
+      <xs:element ref="XArgn" />
+      <xs:element ref="YArgn" />
+      <xs:element ref="XBrgn" />
+      <xs:element ref="YBrgn" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="DCO">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.marker"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="Sdco" />
+      <xs:sequence maxOccurs="unbounded">
+        <xs:element ref="SPdco" />
+      </xs:sequence>
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="VMS">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.marker"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="Cvms" />
+      <xs:element ref="Svms" />
+      <xs:element ref="Wvms" />
+      <xs:element ref="Rvms" />
+      <xs:element ref="Avms" />
+      <xs:element ref="Bvms" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="VMS">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.marker"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="Cvms" />
+      <xs:element ref="Svms" />
+      <xs:element ref="Wvms" />
+      <xs:element ref="Rvms" />
+      <xs:element ref="Avms" />
+      <xs:element ref="Bvms" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="DFS">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.marker"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="Sdfs" />
+      <xs:element ref="Idfs" />
+      <xs:element ref="Ddfs" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="ADS">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.marker"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="Sads" />
+      <xs:element ref="IOads" />
+      <xs:element ref="DOads" />
+      <xs:element ref="ISads" />
+      <xs:element ref="DSads" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="ATK">
+  <xs:complexType>
+
+```
+
+```
+
+    <xs:attributeGroup ref="attrs.marker"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="Satk" />
+      <xs:element ref="Katk" />
+      <xs:element ref="Natk" />
+      <xs:sequence maxOccurs="unbounded">
+        <xs:element ref="Oatk" />
+        <xs:element ref="Eatk" />
+        <xs:element ref="Batk" />
+        <xs:element ref="LCatk" />
+        <xs:sequence maxOccurs="unbounded">
+          <xs:element ref="Aatk" />
+        </xs:sequence>
+      </xs:sequence>
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="CBD">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.marker"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="Ncbd" />
+      <xs:sequence maxOccurs="unbounded">
+        <xs:element ref="BDcbd" />
+      </xs:sequence>
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="MCT">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.marker"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="Zmct" />
+      <xs:element ref="Imct" />
+      <xs:element ref="Ymct" />
+      <xs:sequence maxOccurs="unbounded">
+        <xs:element ref="SPmct" />
+      </xs:sequence>
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="MCC">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.marker"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="Zmcc" />
+      <xs:element ref="Imcc" />
+      <xs:element ref="Ymcc" />
+      <xs:element ref="Qmcc" />
+      <xs:sequence maxOccurs="unbounded">
+        <xs:element ref="Xmcc" />
+        <xs:element ref="Nmcc" />
+      </xs:sequence>
+      <xs:sequence maxOccurs="unbounded">
+        <xs:element ref="Cmcc" />
+      </xs:sequence>
+      <xs:sequence maxOccurs="unbounded">
+        <xs:element ref="Mmcc" />
+      </xs:sequence>
+      <xs:sequence maxOccurs="unbounded">
+        <xs:element ref="Wmcc" />
+      </xs:sequence>
+      <xs:element ref="Tmcc" />
+      <xs:element ref="Omcc" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="MCO">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.marker"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="Nmco" />
+      <xs:sequence maxOccurs="unbounded">
+        <xs:element ref="Imco" />
+      </xs:sequence>
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+```
+
+```
+
+<xs:element name="NLT">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.marker"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="Cnlt" />
+      <xs:element ref="BDnlt" />
+      <xs:element ref="Tnlt" />
+      <xs:sequence maxOccurs="unbounded">
+        <xs:element ref="STnlt" />
+      </xs:sequence>
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="QPD">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.marker"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="PLqpd" />
+      <xs:element ref="PPqpd" />
+      <xs:element ref="Sqpd" />
+      <xs:sequence maxOccurs="unbounded">
+        <xs:element ref="SPqpd" />
+      </xs:sequence>
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="QPC">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.marker"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="Cqpc" />
+      <xs:element ref="PLqpc" />
+      <xs:element ref="PPqpc" />
+      <xs:element ref="Sqpc" />
+      <xs:sequence maxOccurs="unbounded">
+        <xs:element ref="SPqpc" />
+      </xs:sequence>
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<!-- part 1 content element -->
+...
+<!-- part 2 content element -->
+<xs:element name="sso" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="shift" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="XArgn" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="YArgn" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="XBrng" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="YBrng" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="Sdco" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="SPdco" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+
+```
+
+```
+
+    use="required" />
+</xs:element>
+
+<xs:element name="Cvms" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="Svms" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="Wvms" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="Rvms" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="Avms" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="Bvms" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="Sads" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="IOads" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="DOads" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="ISads" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="DSads" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="Satk" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="Katk" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="NatK" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="Oatk" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="EatK" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="BatK" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+```
+
+
+
+```
+</xs:element>
+```
+
+#### B.3.4 Example of an XML schema for a JPEG 2000 Part 8 codestream (security)
+
+```
+<!-- part 1 marker element -->
+...
+<!-- part 8 marker element -->
+<xs:element name="INSEC">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.marker"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="index" />
+      <xs:element ref="Rinsec" />
+      <xs:element ref="APinsec" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="SEC">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.marker"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="Zsec" />
+      <xs:element ref="Psec" />
+      <xs:sequence maxOccurs="unbounded">
+        <xs:element ref="Tool" />
+      </xs:sequence>
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="Psec">
+  <xs:complexType>
+    <xs:attributeGroup ref="attr.hex"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="Fpsec" />
+      <xs:element ref="Ntool" />
+      <xs:element ref="Imax" />
+      <xs:element ref="Ptrlcp" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="Tool">
+  <xs:complexType>
+    <xs:attributeGroup ref="attr.hex"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="type" />
+      <xs:element ref="index" />
+      <xs:element ref="IDtool" />
+      <xs:element ref="length" />
+      <xs:element ref="ZOI" />
+      <xs:element ref="LPid" />
+      <xs:element ref="Pid" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<!-- IDtool for non-normative tools -->
+<xs:element name="IDtool">
+  <xs:complexType>
+    <xs:attributeGroup ref="attr.hex"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="IDaid" />
+      <xs:element ref="IDransl" />
+      <xs:element ref="IDrans" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="ZOI">
+  <xs:complexType>
+    <xs:attributeGroup ref="attr.hex"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="NZzoi" />
+      <xs:element ref="Zone"
+        maxOccurs="unbounded" />
+    </xs:sequence>
+  </xs:complexType>
+```
+
+```
+</xs:element>
+
+<xs:element name="Zone">
+  <xs:complexType>
+    <xs:attributeGroup ref="attr.hex"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="DCzoi" />
+      <xs:element ref="Pzoi"
+        maxOccurs="unbounded" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="Pzoi">
+  <xs:complexType>
+    <xs:attributeGroup ref="attr.hex"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="Mzoi" />
+      <xs:element ref="Nzoi" />
+      <xs:element ref="Izoi"
+        maxOccurs="unbounded" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<!-- Pid for normative tools -->
+<xs:element name="Pid">
+  <xs:complexType>
+    <xs:attributeGroup ref="attr.hex"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="NTid" />
+      <xs:element ref="NTdomain" />
+      <xs:element ref="NTgranularity" />
+      <xs:element ref="NTvalue" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="NTdomain">
+  <xs:complexType>
+    <xs:attributeGroup ref="attr.hex"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="PD" />
+      <xs:element ref="Fpd" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="NTgranularity">
+  <xs:complexType>
+    <xs:attributeGroup ref="attr.hex"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="PD" />
+      <xs:element ref="GL" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="NTvalue">
+  <xs:complexType>
+    <xs:attributeGroup ref="attr.hex"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="Nv" />
+      <xs:element ref="Sv" />
+      <xs:element ref="data" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="NTid">
+  <xs:complexType>
+    <xs:attributeGroup ref="attr.hex"
+      use="required" />
+    <xs:choice>
+      <xs:sequence>
+```
+
+```
+
+<xs:element ref="MEdecry" />
+<xs:element ref="CTdecry" />
+<xs:element ref="CPdecry" />
+</xs:sequence>
+<xs:sequence>
+  <xs:element ref="MEauth" />
+  <xs:element ref="Pauth" />
+</xs:sequence>
+<xs:sequence>
+  <xs:element ref="Hhash" />
+  <xs:element ref="SIZhash" />
+</xs:sequence>
+</xs:choice>
+</xs:complexType>
+</xs:element>
+
+<xs:element name="CPdecry">
+  <xs:complexType>
+    <xs:attributeGroup ref="attr.hex"
+      use="required" />
+
+    <xs:choice>
+      <xs:sequence>
+        <xs:element ref="Mbc" />
+        <xs:element ref="Pbc" />
+        <xs:element ref="SIZbc" />
+        <xs:element ref="KTntid" />
+      </xs:sequence>
+      <xs:sequence>
+        <xs:element ref="KTntid" />
+      </xs:sequence>
+    </xs:choice>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="Pauth">
+  <xs:complexType>
+    <xs:attributeGroup ref="attr.hex"
+      use="required" />
+
+    <xs:choice>
+      <xs:sequence>
+        <xs:element ref="Mhash" />
+        <xs:element ref="Hhash" />
+        <xs:element ref="KTntid" />
+        <xs:element ref="SIZhash" />
+      </xs:sequence>
+      <xs:sequence>
+        <xs:element ref="CACmac" />
+        <xs:element ref="Ccmac" />
+        <xs:element ref="KTntid" />
+        <xs:element ref="SIZcmac" />
+      </xs:sequence>
+      <xs:sequence>
+        <xs:element ref="Mds" />
+        <xs:element ref="Hds" />
+        <xs:element ref="KTntid" />
+        <xs:element ref="SIZds" />
+      </xs:sequence>
+    </xs:choice>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="KTntid">
+  <xs:complexType>
+    <xs:attributeGroup ref="attr.hex"
+      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="LKkt" />
+      <xs:element ref="KIDkt" />
+      <xs:element ref="granularity" />
+      <xs:element ref="data" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<!-- part 1 content element -->
+...
+<!-- part 8 content element -->
+<xs:element name="index" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="Rinsec" type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+    use="required" />
+</xs:element>
+
+```
+
+```
+
+<xs:element name="APinsec" type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+    use="required" />
+</xs:element>
+
+<xs:element name="Zsec" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="Psec" type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+    use="required" />
+</xs:element>
+
+<xs:element name="Tool" type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+    use="required" />
+</xs:element>
+
+<xs:element name="Fpsec" type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+    use="required" />
+</xs:element>
+
+<xs:element name="Ntool" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="Imax" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="Ptrlcp" type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+    use="required" />
+</xs:element>
+
+<xs:element name="type" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="index" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="IDtool" type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+    use="required" />
+</xs:element>
+
+<xs:element name="length" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="ZOI" type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+    use="required" />
+</xs:element>
+
+<xs:element name="LPid" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="Pid" type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+    use="required" />
+</xs:element>
+
+<xs:element name="IDaid" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="IDansi" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="IDrans" type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+
+```
+
+ISO/IEC 15444-14:2013 (E)
+
+```
+
+</xs:element>
+
+<xs:element name="NZzoi" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                     use="required" />
+</xs:element>
+
+<xs:element name="Zone" type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+                     use="required" />
+</xs:element>
+
+<xs:element name="DCzoi" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                     use="required" />
+</xs:element>
+
+<xs:element name="Pzoi" type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+                     use="required" />
+</xs:element>
+
+<xs:element name="Mzoi" type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+                     use="required" />
+</xs:element>
+
+<xs:element name="Nzoi" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                     use="required" />
+</xs:element>
+
+<xs:element name="Izoi" type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+                     use="required" />
+</xs:element>
+
+<xs:element name="NTid" type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+                     use="required" />
+</xs:element>
+
+<xs:element name="NTdomain" type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+                     use="required" />
+</xs:element>
+
+<xs:element name="NTgranularity"
+type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+                     use="required" />
+</xs:element>
+
+<xs:element name="NTvalue" type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+                     use="required" />
+</xs:element>
+
+<xs:element name="PD" type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+                     use="required" />
+</xs:element>
+
+<xs:element name="Fpd" type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+                     use="required" />
+</xs:element>
+
+<xs:element name="PD" type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+                     use="required" />
+</xs:element>
+
+<xs:element name="GL" type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+                     use="required" />
+</xs:element>
+
+<xs:element name="Nv" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                     use="required" />
+</xs:element>
+
+<xs:element name="Sv" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                     use="required" />
+</xs:element>
+
+```
+
+```
+
+</xs:element>
+
+<xs:element name="MEdecry" type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+                     use="required" />
+</xs:element>
+
+<xs:element name="CTdecry" type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+                     use="required" />
+</xs:element>
+
+<xs:element name="CPdecry" type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+                     use="required" />
+</xs:element>
+
+<xs:element name="MEauth" type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+                     use="required" />
+</xs:element>
+
+<xs:element name="Pauth" type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+                     use="required" />
+</xs:element>
+
+<xs:element name="Hhash" type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+                     use="required" />
+</xs:element>
+
+<xs:element name="SIZhash" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                     use="required" />
+</xs:element>
+
+<xs:element name="Mbc" type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+                     use="required" />
+</xs:element>
+
+<xs:element name="Pbc" type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+                     use="required" />
+</xs:element>
+
+<xs:element name="SIZbc" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                     use="required" />
+</xs:element>
+
+<xs:element name="KTntid" type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+                     use="required" />
+</xs:element>
+
+<xs:element name="Mhash" type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+                     use="required" />
+</xs:element>
+
+<xs:element name="Hhash" type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+                     use="required" />
+</xs:element>
+
+<xs:element name="SIZhash" type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+                     use="required" />
+</xs:element>
+
+<xs:element name="CAcmac" type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+                     use="required" />
+</xs:element>
+
+<xs:element name="Ccmac" type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+                     use="required" />
+</xs:element>
+
+<xs:element name="SIZcmac" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                     use="required" />
+</xs:element>
+
+```
+
+ 78 **Rec. ITU-T T.813 (06/2012)**
+
+```
+
+<xs:element name="Mds" type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+    use="required" />
+</xs:element>
+
+<xs:element name="Hds" type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+    use="required" />
+</xs:element>
+
+<xs:element name="SIZds" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="LKkt" type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+    use="required" />
+
+```
+
+```
+
+</xs:element>
+
+<xs:element name="KIDkt" type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+    use="required" />
+</xs:element>
+
+<xs:element name="granularity" type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+    use="required" />
+</xs:element>
+
+<xs:element name="data" type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+    use="required" />
+</xs:element>
+
+```
+
+#### B.3.5 Example of an XML schema for a JPEG 2000 Part 10 codestream (3-D image)
+
+```
+
+<!-- part 1 marker element -->
+...
+<!-- part 10 marker element -->
+<xs:element name="NSI">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.marker"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="Ndim" />
+      <xs:element ref="Zsiz" />
+      <xs:element ref="ZOsiz" />
+      <xs:element ref="ZTsiz" />
+      <xs:element ref="ZTOsiz" />
+      <xs:sequence maxOccurs="unbounded">
+        <xs:element ref="ZRsiz" />
+      </xs:sequence>
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="SPcod">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.hex"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="num_xlevels" />
+      <xs:element ref="num_ylevels" />
+      <xs:element ref="num_zlevels" />
+      <xs:element ref="xcb" />
+      <xs:element ref="ycb" />
+      <xs:element ref="zcb" />
+      <xs:element ref="style" />
+      <xs:element ref="xkernel" />
+      <xs:element ref="ykernel" />
+      <xs:element ref="zkernel" />
+      <xs:element ref="sso" />
+      <xs:element ref="reserved" />
+      <xs:sequence maxOccurs="unbounded">
+        <xs:element ref="ppz" />
+        <xs:element ref="ppy" />
+        <xs:element ref="ppx" />
+      </xs:sequence>
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="SPcoc">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.hex"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="num_xlevels" />
+      <xs:element ref="num_ylevels" />
+      <xs:element ref="num_zlevels" />
+      <xs:element ref="xcb" />
+      <xs:element ref="ycb" />
+      <xs:element ref="zcb" />
+      <xs:element ref="style" />
+      <xs:element ref="xkernel" />
+      <xs:element ref="ykernel" />
+      <xs:element ref="zkernel" />
+      <xs:element ref="sso" />
+      <xs:element ref="reserved" />
+      <xs:sequence maxOccurs="unbounded">
+
+```
+
+```
+
+      <xs:element ref="ppz" />
+      <xs:element ref="ppy" />
+      <xs:element ref="ppx" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="SPrgn">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.hex"
+      use="required" />
+    <xs:sequence>
+      <xs:element ref="shift" />
+      <xs:element ref="XArgn" />
+      <xs:element ref="YArgn" />
+      <xs:element ref="ZArgn" />
+      <xs:element ref="XBrgn" />
+      <xs:element ref="YBrgn" />
+      <xs:element ref="ZBrgn" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="CRG">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.marker"
+      use="required" />
+    <xs:sequence maxOccurs="unbounded">
+      <xs:element ref="Xcrg" />
+      <xs:element ref="Ycrg" />
+      <xs:element ref="Zcrg" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<!-- part 1 content element -->
+...
+<!-- part 10 content element -->
+<xs:element name="Ndim" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="Zsiz" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="ZOsiz" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="ZTsiz" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="ZTOsiz" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+
+<xs:element name="ZRsiz" type="xs:integer">
+
+```
+
+```
+
+<xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="num_xlevels"
+type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="num_ylevels"
+type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="num_zlevels"
+type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="ycb" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="zcb" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+```
+
+```
+
+<xs:element name="zkernel" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="reserved" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="ppz" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="ZArgn" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="ZBrgn" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element name="Zcrg" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+```
+
+#### **B.4.6 Example of an XML schema for a JPEG 2000 Part 11 codestream (wireless)**
+
+```
+
+<!-- part 1 marker element -->
+...
+<!-- part 11 marker element -->
+<xs:element name="EPB">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.marker"
+                      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="Depb" />
+      <xs:element ref="LDPepb" />
+      <xs:element ref="Pepb" />
+      <xs:element ref="data" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="EPC">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.marker"
+                      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="Pcrc" />
+      <xs:element ref="DL" />
+      <xs:element ref="Pepc" />
+      <xs:sequence maxOccurs="unbounded">
+        <xs:element ref="id" />
+        <xs:element ref="Lid" />
+        <xs:element ref="Pid" />
+      </xs:sequence>
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="ESD">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.marker"
+                      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="Cesd" />
+      <xs:element ref="Pesd" />
+      <xs:element ref="data" />
+    </xs:sequence>
+  </xs:complexType>
+</xs:element>
+
+<xs:element name="RED">
+  <xs:complexType>
+    <xs:attributeGroup ref="attrs.marker"
+                      use="required" />
+
+    <xs:sequence>
+      <xs:element ref="Pred" />
+
+```
+
+```
+
+    <xs:element ref="data" />
+  </xs:sequence>
+</xs:complexType>
+</xs:element>
+
+<!-- part 1 content element -->
+...
+<!-- part 11 content element -->
+<xs:element ref="Depb" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element ref="LDPepb" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element ref="Pepb" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element ref="Pcrc" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element ref="DL" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element ref="Pepc" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+                    use="required" />
+</xs:element>
+
+<xs:element ref="id" type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+                    use="required" />
+</xs:element>
+
+<xs:element ref="Lid" type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+                    use="required" />
+</xs:element>
+
+<xs:element ref="Pid" type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+                    use="required" />
+
+```
+
+```
+</xs:element>
+<xs:element ref="Cesd" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+<xs:element ref="Pesd" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+```
+
+```
+<xs:element ref="Pred" type="xs:integer">
+  <xs:attributeGroup ref="attrs.int"
+    use="required" />
+</xs:element>
+<xs:element ref="data" type="hexbyte">
+  <xs:attributeGroup ref="attrs.hex"
+    use="required" />
+</xs:element>
+```
+
+
+
+# Annex C
+
+## Examples and guidelines
+
+(This annex does not form an integral part of this Recommendation | International Standard.)
+
+This annex includes a number of examples intended to indicate how the encoding process works, and how the resulting codestream needs to be output. This annex is entirely informative.
+
+### C.1 Software conventions for the box type
+
+This provides some examples of implementation for box type conversion to a JPXML element name with python, which include no error checking. This alternative version may be more efficient when implemented in software as it has fewer operations along the fast path, and may have error checking mechanisms for a robust application.
+
+#### C.1.1 Conventions to JPXML element name from a box type
+
+```
+def convert_4cc_to_xml(code):
+    p = 0
+    str = ""
+    while p < len(code):
+        ch = code[p]
+        if ch == " ":
+            ch = "_"
+        elif ch == "\\\" and code[p+1:p+4].isdigit():
+            val = int(code[p+1:p+4], 8)
+            if val == 32:
+                ch = "_"
+            else:
+                ch = "." + ("0" + hex(val) [2:]) [-2:]
+            p += 3
+        elif not ch.isalnum():
+            ch = "." + ("0" + hex(ord(ch)) [2:]) [-2:]
+        p += 1
+        str += ch
+    if str[0] == "_" or str[0] == "." or str[0].isdigit() or str[:3] == "xml":
+        str = "_" + str
+    return str
+```
+
+Figure C.1 – Python source code for converting a box type to a JPXML element name
+
+#### C.1.2 Conventions from JPXML element name to a box type
+
+```
+def convert_xml_to_4cc(code):
+    if code[0] == "_":
+        code = code[1:]
+    p = 0
+    str = ""
+    while p < len(code):
+        ch = code[p]
+        if ch == "_":
+            ch = "\\040"
+        elif ch == ".":
+            ch = "\\" + ("0" + oct(int(code[p+1:p+3], 16)))[-3:]
+            p += 2
+        p += 1
+        str += ch
+    return str
+```
+
+Figure C.2 – Python source code for converting a JPXML element name to a box type
+
+### C.2 Example of JPXML document conversion
+
+This JPEG 2000 image example consists of six boxes, and the "jp2h" superbox contains "ihdr" and "colr" boxes. Each box has an LBox value, so the converter will use it as the length attribute value in each box element. The last box may have zero length representations that content data extends to the end of a file.
+
+```
+Box[0] Type: 'jP\040\040', offset=0x00000, length=12.
+    <JPEG2000 Signature box : d0a870a>.
+
+Box[1] Type: 'ftyp', offset=0x0000c, length=20.
+    <File Type box>.
+    Brand='jp2 ', Minor Version=0.
+    Compatibility: 'jp2 '
+
+Box[2] Type: 'jp2h', offset=0x00020, length=45
+    |   <JP2 Header box [JP2]> <superbox>
+    |   Box[3] Type: 'ihdr', offset=0x00028, length=22
+    |   |   <Image Header box>
+    |   |   Image size=(400, 300), Depth=8, Number of components=3,
+    |   |   Compression type(7)=ITU-T T.800 (JPEG2000),
+    |   |   Colour type(1)=unknown
+    |   |
+    |   |   Box[4] Type: 'colr', offset=0x0003e, length=15
+    |   |   |   <Colour Specification box>
+    |   |   |   Method(1)= Enumerated Colour space
+    |   |   |   Prec=0, Approx=0, Colour(16 )=sRGB
+    |   |
+    |   |   Box[5] Type: 'jp2c', offset=0x0004d, length=0
+    |   |   |   <Contiguous Codestream box><stream[0]>
+    |   |   |   Codestream offset=85 (0x00055), Length=196439 (0x2ff57)
+```
+
+Figure C.3 – Example of an input image for this JPXML representation process
+
+#### C.2.1 JPXML structural document
+
+The "jP\040\040" box type is converted to a "jP\_\_" element name, and other 4CC box types are used for the element names. If there is an XML container box in an image, an element name needs to be "\_xml\_". The root element of the JPXML document, "jpBox", needs to have a file attribute for identifying the file name of this document. Each box needs to have a length attribute and a location reference to a box itself in an image, and the location reference needs to be represented with an XML structure.
+
+For the purpose of representing image structure, a JPXML document without box contents may be used. This document may have base64 binary converted contents for some purposes. In many cases, this document may have a length attribute for calculating an absolute offset location from a structural relative location address with XML form.
+
+```
+<?xml version="1.0" ?>
+<jx:jpxml x1="http://www.w3.org/1999/xlink"
+          jx="http://www.iso.org/jpeg/jpxml/1.0"
+          jx:file="small-lena.jp2">
+  <jx:jP__ length="12" type="box:box" />
+  <jx:ftyp length="20" type="box:box" />
+  <jx:jp2h length="45" type="box:box" >
+    <jx:ihdr length="22" type="box:box" />
+    <jx:colr length="15" type="box:box" />
+  </jx:jp2h>
+  <jx:jp2c length="0" x1:href="#xpointer(box:jp2c)" />
+</jx:jpxml>
+```
+
+Figure C.4 – An example of a JPXML document without box contents
+
+The JPXML document with box content elements may be used for image conversion, image editing, image security, etc. In many cases, this document needs to have a length attribute for calculating an absolute offset location from a structural relative location address with XML form. The length attribute in the box needs to be changed correctly when box contents are added or changed.
+
+```
+<?xml version="1.0" ?>
+<jx:jpxml x1="http://www.w3.org/1999/xlink" xs="http://www.w3.org/2001/XMLSchema"
+          jx="http://www.jpeg.org/jpeg/jpxml/1.0" jx:file="lena.jp2">
+  <jx:jP__ length="12" type="jx:box">
+    <jx:signature length="4" type="xs:hexBinary">0x0d0a870a</jx:signature>
+  </jx:jP__>
+  <jx:ftyp length="20" type="jx:box">
+    <jx:brand length="4" type="xs:string">jp2 </jx:brand>
+    <jx:version length="4" type="xs:int">0</jx:version>
+    <jx:compatibility length="4" type="xs:string">jp2 </jx:compatibility>
+  </jx:ftyp>
+  <jx:jp2h length="45" type="jx:box">
+    <jx:ihdr length="22" type="jx:box">
+      <jx:width length="4" type="xs:int">512</jx:width>
+      <jx:height length="4" type="xs:int">512</jx:height>
+      <jx:depth length="2" type="xs:int">8</jx:depth>
+      <jx:num_components length="1" type="xs:int">3</jx:num_components>
+      <jx:coding length="1" type="xs:int">7</jx:coding><!--ITU-T T.800-->
+      <jx:colour length="1" type="xs:int">1</jx:colour><!--unknown-->
+      <jx:ipr length="1" type="xs:boolean">>false</jx:ipr>
+    </jx:ihdr>
+    <jx:colr length="15" type="jx:box">
+      <jx:method length="1" type="xs:int">1</jx:method><!--Enumerated colour-->
+    >
+      <jx:precision length="1" type="xs:int">0</jx:precision>
+      <jx:approx length="1" type="xs:int">0</jx:approx>
+      <jx:colour length="4" type="xs:int">16</jx:colour><!--sRGB-->
+    </jx:colr >
+  </jx:jp2h>
+  <jx:jp2c length="0" x1:href="#xpointer(jx:jp2c)" />
+</jx:jpxml>
+```
+
+Figure C.5 – An example of a JPXML document with box content child elements
+
+#### C.2.2 Reference to internal data in an image
+
+The relative location generator converts an absolute offset location to a structural location path which is expressed by XML location tools; XPath, XLink and XPointer. The absolute location generator conducts reverse order of the relative location conversion process. Figure 7 illustrates converting processes between absolute and relative locations. These generators need the schemas to calculate each location when an input from these generators has no box length information, because the generator uses box length values for identifying a box element location in the XML domain. The process of generating a relative location consists of two steps: 1) repeat reading a box element's length attribute and subtracting its length value from an offset value whenever the offset is greater than the reading of a current box length, and 2) describe an XML location of the extracted element by using XML location tools, e.g., the offset "54" in Figure 3 is the location to the element of '<ihdr />'; Image Header box ('ihdr'), so the location of offset "54" is converted to 'xpointer (//ihdr)' or 'xpointer (/jpBox/ihdr)'.
+
+
+
+# SERIES OF ITU-T RECOMMENDATIONS
+
+|                 |                                                                                             |
+|-----------------|---------------------------------------------------------------------------------------------|
+| Series A        | Organization of the work of ITU-T                                                           |
+| Series D        | General tariff principles                                                                   |
+| Series E        | Overall network operation, telephone service, service operation and human factors           |
+| Series F        | Non-telephone telecommunication services                                                    |
+| Series G        | Transmission systems and media, digital systems and networks                                |
+| Series H        | Audiovisual and multimedia systems                                                          |
+| Series I        | Integrated services digital network                                                         |
+| Series J        | Cable networks and transmission of television, sound programme and other multimedia signals |
+| Series K        | Protection against interference                                                             |
+| Series L        | Construction, installation and protection of cables and other elements of outside plant     |
+| Series M        | Telecommunication management, including TMN and network maintenance                         |
+| Series N        | Maintenance: international sound programme and television transmission circuits             |
+| Series O        | Specifications of measuring equipment                                                       |
+| Series P        | Terminals and subjective and objective assessment methods                                   |
+| Series Q        | Switching and signalling                                                                    |
+| Series R        | Telegraph transmission                                                                      |
+| Series S        | Telegraph services terminal equipment                                                       |
+| <b>Series T</b> | <b>Terminals for telematic services</b>                                                     |
+| Series U        | Telegraph switching                                                                         |
+| Series V        | Data communication over the telephone network                                               |
+| Series X        | Data networks, open system communications and security                                      |
+| Series Y        | Global information infrastructure, Internet protocol aspects and next-generation networks   |
+| Series Z        | Languages and general software aspects for telecommunication systems                        |
\ No newline at end of file
diff --git a/marked/T/T-REC-T.814-201906-I_PDF-E/043e64d41a3368d138ace3816fd26469_img.jpg b/marked/T/T-REC-T.814-201906-I_PDF-E/043e64d41a3368d138ace3816fd26469_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..ba2115fec732c9d874689df147cc0def105e9899
--- /dev/null
+++ b/marked/T/T-REC-T.814-201906-I_PDF-E/043e64d41a3368d138ace3816fd26469_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:8ae1461bb3ba0fc00a67c124edb5e749b5d79da5918488bd4597e20b97055771
+size 60594
diff --git a/marked/T/T-REC-T.814-201906-I_PDF-E/257c8341b41f1f4a287f27d33227974c_img.jpg b/marked/T/T-REC-T.814-201906-I_PDF-E/257c8341b41f1f4a287f27d33227974c_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..7d83ee44c24f82a67be1fb841b4c4268f365148f
--- /dev/null
+++ b/marked/T/T-REC-T.814-201906-I_PDF-E/257c8341b41f1f4a287f27d33227974c_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:02a58f0a736d6b8be6c88005d6fc8537e2198589e196858926ae4488cf91f321
+size 41392
diff --git a/marked/T/T-REC-T.814-201906-I_PDF-E/2eb23c2210154279f8013a1594fbcc5a_img.jpg b/marked/T/T-REC-T.814-201906-I_PDF-E/2eb23c2210154279f8013a1594fbcc5a_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..c3743fe7f80246265f7adeb85f56b762b6770439
--- /dev/null
+++ b/marked/T/T-REC-T.814-201906-I_PDF-E/2eb23c2210154279f8013a1594fbcc5a_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:6aa3f9309b7f5f0c4f4b82687d1b531b9714ef94984bae46f66ad1d0c8364a6e
+size 61999
diff --git a/marked/T/T-REC-T.814-201906-I_PDF-E/44c70af075e4d9bbc6fbe267a666b3b0_img.jpg b/marked/T/T-REC-T.814-201906-I_PDF-E/44c70af075e4d9bbc6fbe267a666b3b0_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..48ce247af5a6363e081880f861d810e6ea8b19b5
--- /dev/null
+++ b/marked/T/T-REC-T.814-201906-I_PDF-E/44c70af075e4d9bbc6fbe267a666b3b0_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:2917819b9b340fd7409cd08256f897dd81c77f353ba773582539cc17ff07af0f
+size 7493
diff --git a/marked/T/T-REC-T.814-201906-I_PDF-E/812e188283162af0b54fb3e30ffee51b_img.jpg b/marked/T/T-REC-T.814-201906-I_PDF-E/812e188283162af0b54fb3e30ffee51b_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..b4cf17a653b31fbd45a9a6dd570d88628e79a866
--- /dev/null
+++ b/marked/T/T-REC-T.814-201906-I_PDF-E/812e188283162af0b54fb3e30ffee51b_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:886ea7e158a9939bbd57abac172d99bcde0cafb72c2dded7f10f85dd9183ea35
+size 33457
diff --git a/marked/T/T-REC-T.814-201906-I_PDF-E/a0739aaf13fa5a632d4faa830f6b2708_img.jpg b/marked/T/T-REC-T.814-201906-I_PDF-E/a0739aaf13fa5a632d4faa830f6b2708_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..7a904f96a85de57a64a562f913bf89084dab23e1
--- /dev/null
+++ b/marked/T/T-REC-T.814-201906-I_PDF-E/a0739aaf13fa5a632d4faa830f6b2708_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:b182cdf15cde6a9408ebd0ac18ff6f1ce0777ca6a942dcc746dcb7040dacd900
+size 24256
diff --git a/marked/T/T-REC-T.814-201906-I_PDF-E/a7c51c18111139f9aca2805114108565_img.jpg b/marked/T/T-REC-T.814-201906-I_PDF-E/a7c51c18111139f9aca2805114108565_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..340ce6559a2cb14768591de0dfc474b1ff0724b3
--- /dev/null
+++ b/marked/T/T-REC-T.814-201906-I_PDF-E/a7c51c18111139f9aca2805114108565_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:be2441d8a56ca346707949d1730e206c012c48b98c18a5fc4e953053fe020fe9
+size 32941
diff --git a/marked/T/T-REC-T.814-201906-I_PDF-E/e05434e963901d7e9c0bf5a6758200ed_img.jpg b/marked/T/T-REC-T.814-201906-I_PDF-E/e05434e963901d7e9c0bf5a6758200ed_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..fb29eddb417ff411239ecd68de9106f73ee406c0
--- /dev/null
+++ b/marked/T/T-REC-T.814-201906-I_PDF-E/e05434e963901d7e9c0bf5a6758200ed_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:e745d1ddadf05e4407de3132235f05af27fa9742e8ebfd82b5a3bfbf5cee8adc
+size 18442
diff --git a/marked/T/T-REC-T.814-201906-I_PDF-E/e0627c8e3dfda5da1ee8d5a90c9f7489_img.jpg b/marked/T/T-REC-T.814-201906-I_PDF-E/e0627c8e3dfda5da1ee8d5a90c9f7489_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..7d3749a2f037a4aba740feff55c3d3e278605ec7
--- /dev/null
+++ b/marked/T/T-REC-T.814-201906-I_PDF-E/e0627c8e3dfda5da1ee8d5a90c9f7489_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:a8093fa682c7e1efff5577e598b822972db719c5aed83a5dc90469afaf2867a3
+size 60716
diff --git a/marked/T/T-REC-T.814-201906-I_PDF-E/e518bff13dc73675afd211dbea636c29_img.jpg b/marked/T/T-REC-T.814-201906-I_PDF-E/e518bff13dc73675afd211dbea636c29_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..66c798c929669dfa8596a2e6a594ad37c9210761
--- /dev/null
+++ b/marked/T/T-REC-T.814-201906-I_PDF-E/e518bff13dc73675afd211dbea636c29_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:d66003120da3b61ac04c7d43b66d1a8f8b07f636bdaacbb2d5ff4469fef86571
+size 59585
diff --git a/marked/T/T-REC-T.814-201906-I_PDF-E/e64b41a22015ac3a9c17115aabd51e53_img.jpg b/marked/T/T-REC-T.814-201906-I_PDF-E/e64b41a22015ac3a9c17115aabd51e53_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..535afd2a739dbcb8c9481b7454c33431a66cb83a
--- /dev/null
+++ b/marked/T/T-REC-T.814-201906-I_PDF-E/e64b41a22015ac3a9c17115aabd51e53_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:42085de796f0314a04a409b4f30faa4382f671736cb9971e2411cd30d0ce760c
+size 10151
diff --git a/marked/T/T-REC-T.814-201906-I_PDF-E/e8ba5d4a3a22e24e44f7935ea26afcb0_img.jpg b/marked/T/T-REC-T.814-201906-I_PDF-E/e8ba5d4a3a22e24e44f7935ea26afcb0_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..94b92c185ee1095db3694163bad34e2ab6d3bc18
--- /dev/null
+++ b/marked/T/T-REC-T.814-201906-I_PDF-E/e8ba5d4a3a22e24e44f7935ea26afcb0_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:349f285e652aeccbd3fde4eb8c29224af78f3ed99e8164f79a0f6fdbca9b3404
+size 4164
diff --git a/marked/T/T-REC-T.814-201906-I_PDF-E/f4fdd410cdb84df81274da55721e56fb_img.jpg b/marked/T/T-REC-T.814-201906-I_PDF-E/f4fdd410cdb84df81274da55721e56fb_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..ff4e8c262ed90369a19e1601bd2a6dbf723e5ded
--- /dev/null
+++ b/marked/T/T-REC-T.814-201906-I_PDF-E/f4fdd410cdb84df81274da55721e56fb_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:e12d8c9599e4defa7093fa091ce58b457c2d2ce2281ad386da7b02817c1cdd06
+size 46997
diff --git a/marked/T/T-REC-T.814-201906-I_PDF-E/raw.md b/marked/T/T-REC-T.814-201906-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..7750c56bbf96aca2c75652ba1f27a36aa242cf88
--- /dev/null
+++ b/marked/T/T-REC-T.814-201906-I_PDF-E/raw.md
@@ -0,0 +1,3637 @@
+
+
+I n t e r n a t i o n a l   T e l e c o m m u n i c a t i o n   U n i o n
+
+# ITU-T
+
+TELECOMMUNICATION  
+STANDARDIZATION SECTOR  
+OF ITU
+
+# T.814
+
+(06/2019)
+
+SERIES T: TERMINALS FOR TELEMATIC SERVICES  
+Still-image compression – JPEG 2000
+
+---
+
+**Information technology – JPEG 2000 image  
+coding system: High-throughput JPEG 2000**
+
+Recommendation ITU-T T.814
+
+# ITU-T T-SERIES RECOMMENDATIONS **TERMINALS FOR TELEMATIC SERVICES**
+
+|                                                     |                    |
+|-----------------------------------------------------|--------------------|
+| Facsimile – Framework                               | T.0–T.19           |
+| Still-image compression – Test charts               | T.20–T.29          |
+| Facsimile – Group 3 protocols                       | T.30–T.39          |
+| Colour representation                               | T.40–T.49          |
+| Character coding                                    | T.50–T.59          |
+| Facsimile – Group 4 protocols                       | T.60–T.69          |
+| Telematic services – Framework                      | T.70–T.79          |
+| Still-image compression – JPEG-1, Bi-level and JBIG | T.80–T.89          |
+| Telematic services – ISDN Terminals and protocols   | T.90–T.99          |
+| Videotext – Framework                               | T.100–T.109        |
+| Data protocols for multimedia conferencing          | T.120–T.149        |
+| Telewriting                                         | T.150–T.159        |
+| Multimedia and hypermedia framework                 | T.170–T.189        |
+| Cooperative document handling                       | T.190–T.199        |
+| Telematic services – Interworking                   | T.300–T.399        |
+| Open document architecture                          | T.400–T.429        |
+| Document transfer and manipulation                  | T.430–T.449        |
+| Document application profile                        | T.500–T.509        |
+| Communication application profile                   | T.510–T.559        |
+| Telematic services – Equipment characteristics      | T.560–T.619        |
+| General multimedia application frameworks           | T.620–T.649        |
+| <b>Still-image compression – JPEG 2000</b>          | <b>T.800–T.829</b> |
+| Still-image compression   JPEG XR                   | T.830–T.849        |
+| Still-image compression – JPEG-1 extensions         | T.850–T.899        |
+
+*For further details, please refer to the list of ITU-T Recommendations.*
+
+# Information technology – JPEG 2000 image coding system: High-throughput JPEG 2000
+
+## Summary
+
+The computational complexity of the block-coding algorithm of Rec. ITU-T T.800 | ISO/IEC 15444-1 can be a challenge in some applications.
+
+Rec. ITU-T T.814 | ISO/IEC 15444-15 specifies a high-throughput (HT) block-coding algorithm that can be used in place of the block-coding algorithm specified in Rec. ITU-T T.800 | ISO/IEC 15444-1.
+
+The HT block-coding algorithm increases decoding and encoding throughput and allows mathematically lossless transcoding to and from the block-coding algorithm specified in Rec. ITU-T T.800 | ISO/IEC 15444-1. This is achieved at the expense of some loss in coding efficiency and substantial elimination of quality scalability.
+
+The HT block-coding algorithm adopts a coding pass structure like that of the block-coding algorithm of Rec. ITU-T T.800 | ISO/IEC 15444-1. No more than three coding passes are required for any given code-block in the final codestream, and arithmetic coding is replaced with a combination of variable length coding tools, adaptive run-length coding and simple bit-packing. The algorithm involves three passes: a significance propagation pass (HT SigProp coding pass), a magnitude refinement pass (HT MagRef coding pass) and a cleanup pass (HT cleanup coding pass).
+
+The HT MagRef coding pass is identical to that of the block-coding algorithm of Rec. ITU-T T.800 | ISO/IEC 15444-1, operating in the bypass mode, except that code bits are packed into bytes with a little-endian bit order. That is, the first code bit in a byte appears in its LSB, as opposed to its MSB.
+
+The HT SigProp coding pass is also very similar to that of the block-coding algorithm of Rec. ITU-T T.800 | ISO/IEC 15444-1, operating in the BYPASS mode, with the following two differences:
+
+- code bits are again packed into bytes of the raw bit-stream with a little-endian bit order, instead of big-endian bit packing order; and
+- the significance bits associated with a set of four stripe columns are emitted first, followed by the associated sign bits, before advancing to the next set of stripe columns, instead of inserting any required sign bit immediately after the same sample's magnitude bit.
+
+The HT cleanup coding pass is, however, significantly different from that of the block-coding algorithm of Rec. ITU-T T.800 | ISO/IEC 15444-1, and most of ITU-T T.814 | ISO/IEC 15444-15 is devoted to its description.
+
+Aside from the block-coding algorithm itself and the parsing of packet headers, the HT block-coding algorithm preserves the syntax and semantics of other parts of the codestream specified in Rec. ITU-T T.800 | ISO/IEC 15444-1.
+
+Recommendation ITU-T T.814 (2019) is a common text with ISO/IEC 15444-15:2019, both in their first edition.
+
+## History
+
+| Edition | Recommendation | Approval   | Study Group | Unique ID*                                                                      |
+|---------|----------------|------------|-------------|---------------------------------------------------------------------------------|
+| 1.0     | ITU-T T.814    | 2019-06-13 | 16          | <a href="http://handle.itu.int/11.1002/1000/11830-en">11.1002/1000/11830-en</a> |
+
+---
+
+\* To access the Recommendation, type the URL <http://handle.itu.int/> in the address field of your web browser, followed by the Recommendation's unique ID. For example, <http://handle.itu.int/11.1002/1000/11830-en>.
+
+## FOREWORD
+
+The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis.
+
+The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics.
+
+The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1.
+
+In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC.
+
+### NOTE
+
+In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party.
+
+## INTELLECTUAL PROPERTY RIGHTS
+
+ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process.
+
+As of the date of approval of this Recommendation, ITU had received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at <http://www.itu.int/ITU-T/ipr/>.
+
+© ITU 2019
+
+All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU.
+
+## CONTENTS
+
+|                                                                         | <i>Page</i> |
+|-------------------------------------------------------------------------|-------------|
+| 1 Scope .....                                                           | 1           |
+| 2 Normative references .....                                            | 1           |
+| 3 Terms and definitions .....                                           | 1           |
+| 4 Abbreviations and symbols .....                                       | 1           |
+| 5 Convention .....                                                      | 2           |
+| 6 Conformance .....                                                     | 2           |
+| 6.1 HTJ2K codestream.....                                               | 2           |
+| 6.2 HTJ2K decoding algorithm.....                                       | 2           |
+| 6.3 JPH file .....                                                      | 3           |
+| 7 HT block decoding algorithm.....                                      | 3           |
+| 7.1 Retrieving bit-streams from HT segments .....                       | 3           |
+| 7.2 Quad-based scanning pattern .....                                   | 9           |
+| 7.3 HT Cleanup decoding algorithm .....                                 | 10          |
+| 7.4 HT SigProp decoding procedure .....                                 | 20          |
+| 7.5 HT MagRef decoding procedure.....                                   | 22          |
+| 7.6 Sample output values .....                                          | 22          |
+| 8 Constrained codestream sets.....                                      | 23          |
+| 8.1 Overview.....                                                       | 23          |
+| 8.2 HTONLY, HTDECLARED and MIXED sets .....                             | 23          |
+| 8.3 SINGLEHT and MULTIHT sets .....                                     | 23          |
+| 8.4 RGN and RGNFREE sets .....                                          | 23          |
+| 8.5 HOMOGENEOUS and HETEROGENEOUS sets .....                            | 23          |
+| 8.6 LOCAL and FRAG sets.....                                            | 24          |
+| 8.7 Bounded magnitude sets .....                                        | 24          |
+| 8.8 CPF <sub>N</sub> sets.....                                          | 25          |
+| 9 Media types .....                                                     | 26          |
+| Annex A (normative) – HTJ2K codestream syntax.....                      | 27          |
+| A.1 General .....                                                       | 27          |
+| A.2 SIZ marker segment .....                                            | 27          |
+| A.3 CAP marker segment .....                                            | 27          |
+| A.4 COD and COC marker segments .....                                   | 29          |
+| A.5 RGN marker segment.....                                             | 30          |
+| A.6 Corresponding Profile (CPF) marker segment .....                    | 30          |
+| Annex B (normative) – HT data organization .....                        | 32          |
+| B.1 HT Sets .....                                                       | 32          |
+| B.2 HT segments .....                                                   | 32          |
+| B.3 Packets, Z_blk and S_blk.....                                       | 32          |
+| Annex C (normative) – CxtVLC tables .....                               | 34          |
+| Annex D (normative) – JPH file format .....                             | 54          |
+| D.1 General .....                                                       | 54          |
+| D.2 JP2 Header box .....                                                | 54          |
+| D.3 File Type box .....                                                 | 54          |
+| D.4 Colour Specification box.....                                       | 54          |
+| D.5 Contiguous Codestream box .....                                     | 55          |
+| D.6 Channel Definition box .....                                        | 55          |
+| Annex E (normative) – Media type specifications and registrations ..... | 57          |
+| E.1 General .....                                                       | 57          |
+| E.2 JPH file .....                                                      | 57          |
+| E.3 Single HTJ2K codestream.....                                        | 57          |
+| Annex F (informative) – HT block encoding procedures .....              | 59          |
+| F.1 Overview.....                                                       | 59          |
+
+|                                                                |    |
+|----------------------------------------------------------------|----|
+| F.2 Bit-planes, exponents, MagSgn values and EMB patterns..... | 61 |
+| F.3 Cleanup pass encoding steps .....                          | 62 |
+| F.4 Bit-stuffing and byte-stream termination procedures.....   | 65 |
+| Bibliography .....                                             | 72 |
+
+# INTERNATIONAL STANDARD ITU-T RECOMMENDATION
+
+# Information technology – JPEG 2000 image coding system: High-throughput JPEG 2000
+
+# 1 Scope
+
+This Recommendation | International Standard specifies an alternate block-coding algorithm that can be used in place of the block-coding algorithm specified in Rec. ITU-T T.800 | ISO/IEC 15444-1. This alternate block-coding algorithm offers a significant increase in throughput at the expense of slightly reduced coding efficiency, while a) allowing mathematically lossless transcoding to and from codestreams that use the block-coding algorithm specified in Rec. ITU-T T.800 | ISO/IEC 15444-1, and b) preserving codestream syntax and features specified in Rec. ITU-T T.800 | ISO/IEC 15444-1.
+
+Recommendation ITU-T T.814 (2019) is a common text with ISO/IEC 15444-15:2019, both in their first edition.
+
+# 2 Normative references
+
+The following Recommendations and International Standards contain provisions which, through reference in this text, constitute provisions of this Recommendation | International Standard. At the time of publication, the editions indicated were valid. All Recommendations and Standards are subject to revision, and parties to agreements based on this Recommendation | International Standard are encouraged to investigate the possibility of applying the most recent edition of the Recommendations and Standards listed below. Members of IEC and ISO maintain registers of currently valid International Standards. The Telecommunication Standardization Bureau of the ITU maintains a list of currently valid ITU-T Recommendations.
+
+## 2.1 Identical Recommendations | International Standards
+
+- Recommendation ITU-T T.800 (2019) | ISO/IEC 15444-1:2019, *Information technology – JPEG 2000 image coding system: Core coding system*.
+
+## 2.2 Paired Recommendations | International Standards equivalent in technical content
+
+- Recommendation ITU-T H.273 (2016), *Coding-independent code points for video signal type identification*.
+- ISO/IEC 23001-8:2016, *Information technology – MPEG systems technologies – Part 8: Coding-independent code points*.
+
+## 2.3 Additional references
+
+- ISO/IEC 15076-1, *Image technology colour management – Architecture, profile format and data structure – Part 1: Based on ICC.1:2010*.
+
+# 3 Terms and definitions
+
+For the purposes of this Recommendation | International Standard, the terms and definitions given in Rec. ITU-T T.800 | ISO/IEC 15444-1 apply.
+
+# 4 Abbreviations
+
+For the purposes of this Recommendation | International Standard, the abbreviations and symbols defined in Rec. ITU-T T.800 | ISO/IEC 15444-1 and the following apply.
+
+|        |                                       |
+|--------|---------------------------------------|
+| AZC    | All Zero Context                      |
+| CUP    | Cleanup coding Pass                   |
+| CPF    | Corresponding Profile                 |
+| CxtVLC | Context adaptive Variable Length Code |
+| EMB    | Exponent Max Bound                    |
+| FRAG   | Fragmented                            |
+| HT     | High-Throughput                       |
+| HTJ2K  | High-Throughput JPEG 2000             |
+
+|         |                              |
+|---------|------------------------------|
+| HTIRV   | High-Throughput Irreversible |
+| HTREV   | High-Throughput Reversible   |
+| LSB     | Least-Significant Bit        |
+| MAGB    | Magnitude Bound              |
+| MagRef  | Magnitude Refinement         |
+| MagSgn  | Magnitude and Sign           |
+| MRP     | MagRef coding pass           |
+| MSB     | Most-Significant Bit         |
+| SigProp | Significance Propagation     |
+| U-VLC   | Unsigned residual VLC        |
+| VLC     | Variable Length Coding       |
+
+# 5 Conventions and symbols
+
+For the purposes of this Recommendation | International Standard, the symbols defined in Rec. ITU-T T.800 | ISO/IEC 15444-1 and the following apply:
+
+|         |                                                         |
+|---------|---------------------------------------------------------|
+| Dcup[n] | Byte n of an HT Cleanup segment                         |
+| Dref[n] | Byte n of an HT Refinement segment                      |
+| Hblk    | Height of a code-block, measured in samples             |
+| Lcup    | Length in bytes of HT Cleanup segment                   |
+| Lref    | Length in bytes of HT Refinement segment                |
+| MEL     | Adaptive run-length coding algorithm                    |
+| MEL_E   | MEL Exponent Table                                      |
+| Pcup    | HT Cleanup segment prefix length                        |
+| QH      | Height of a code-block, measured in quads               |
+| QW      | Width of a code-block, measured in quads                |
+| Scup    | HT Cleanup segment suffix length                        |
+| SPP     | HT SigProp coding Pass                                  |
+| u_ext   | U-VLC extension component                               |
+| u_pfx   | U-VLC prefix component                                  |
+| u_sfx   | U-VLC suffix component                                  |
+| Wblk    | Width of a code-block, measured in samples              |
+| Z_blk   | Number of passes that can be processed within an HT Set |
+
+# 6 Conformance
+
+## 6.1 HTJ2K codestream
+
+A high-throughput JPEG 2000 (HTJ2K) codestream shall conform to Annex A.
+
+## 6.2 HTJ2K decoding algorithm
+
+The HTJ2K decoding algorithm processes an HTJ2K codestream as specified in Rec. ITU-T T.800 | ISO/IEC 15444-1 together with any additional signalled capability, with the exception of HT code-blocks, as defined in Annex B, in which case the following applies:
+
+- the HT code-blocks are processed according to clause 7; and
+
+- the resulting number of magnitude bits  $N_b$ , the magnitude bits  $MSB_f(b)$  and the sign bits  $s_b$  are processed according to Rec. ITU-T T.800 | ISO/IEC 15444-1, together with any additional signalled capability.
+
+NOTE 1 – If the two most significant bits of  $Ccap^{15}$  are 0 for a codestream, all code-blocks are HT code-blocks and the decoding procedures defined in Annexes C and D of Rec. ITU-T T.800 | ISO/IEC 15444-1 are not used.
+
+NOTE 2 – The processing of HT code-blocks specified herein is compatible with the additional capabilities specified in Rec. ITU-T T.801 | ISO/IEC 15444-2.
+
+NOTE 3 – The symbols  $N_b$ ,  $MSB_f(b)$  and  $s_b$  are defined in Rec. ITU-T T.800 | ISO/IEC 15444-1.
+
+## 6.3 JPH file
+
+A JPH file shall conform to Annex D.
+
+# 7 HT block-decoding algorithm
+
+## 7.1 Retrieving bit-streams from HT segments
+
+### 7.1.1 General
+
+This clause specifies the process for extracting bit-streams from an HT set and its associated parameters  $z\_blk$  and  $s\_blk$ , as defined in Annex B.
+
+If  $z\_blk$  equals 0, no HT segments are available for the code-block, and so all sample output values for the block shall be 0.
+
+There are at most two HT segments available to the HT block-decoding algorithm:
+
+- The HT cleanup segment holds the coded bytes belonging to the HT cleanup coding pass (CUP);
+- The HT refinement segment holds the coded bytes belonging to the HT significance propagation (SigProp) coding pass and, optionally, an HT magnitude refinement (MagRef) coding pass. The HT refinement segment is available if and only if  $z\_blk$  is greater than 1, while an HT MagRef coding pass is available if and only if  $z\_blk$  is equal to 3.
+
+NOTE 1 – Multiple sets of HT cleanup and HT refinement segments can be found within the codestream for a given code-block, but the decoding procedure described here processes only  $z\_blk$  coding passes, whose coded bytes are found within one HT cleanup segment and, if  $z\_blk$  is greater than 1, the one HT refinement segment that follows this HT cleanup segment.
+
+As illustrated in Figure 1, the HT segments are comprised of byte-streams, each an ordered sequence of bytes. From each byte-stream, a bit-stream, which is an ordered sequence of bits, can be unpacked as follows:
+
+- The magnitude and sign (MagSgn) bit-stream is recovered from the MagSgn byte-stream, which extends forward from byte 0 of the HT cleanup segment for a total of  $P_{cup}$  bytes, with prefix length,  $P_{cup} = L_{cup} - S_{cup}$ ; where  $L_{cup}$  is the length (in bytes) of the HT cleanup segment, and  $S_{cup}$  is a suffix length.
+- The adaptive run-length coding algorithm (MEL) bit-stream is recovered from the MEL byte-stream, which extends forward from byte  $P_{cup}$  of the HT cleanup segment, for at most  $S_{cup}$  bytes.
+- The variable length coding (VLC) bit-stream is recovered from the VLC byte-stream, which extends backward from the last byte of the HT cleanup segment, for at most  $S_{cup}$  bytes. The VLC and MEL byte-streams may overlap.
+- If  $z\_blk$  is greater than 1, the SigProp bit-stream is recovered from the SigProp byte-stream, which extends forwards from byte 0 of the HT refinement segment, for at most  $L_{ref}$  bytes, where  $L_{ref}$  is the length of the HT refinement segment.
+- If  $z\_blk$  is equal to 3, the MagRef bit-stream is recovered from the MagRef byte-stream, which extends backwards from the end (byte  $L_{ref}-1$ ) of the HT refinement segment, for at most  $L_{ref}$  bytes. The MagRef and SigProp byte-streams may overlap.
+
+![Diagram illustrating HT segments and their byte-streams. The top segment is the HT Cleanup segment, which consists of the MagSgn byte-stream (length Pcup = Lcup - Scup bytes) and the MEL byte-stream (length Scup bytes). The bottom segment is the HT Refinement segment, which consists of the SigProp byte-stream and the MagRef byte-stream. The total length of the HT Cleanup segment is Lcup bytes, and the total length of the HT Refinement segment is Lref bytes. The diagram also shows the VLC byte-stream following the MEL byte-stream.](f4fdd410cdb84df81274da55721e56fb_img.jpg)
+
+T.814(19)\_F01
+
+Diagram illustrating HT segments and their byte-streams. The top segment is the HT Cleanup segment, which consists of the MagSgn byte-stream (length Pcup = Lcup - Scup bytes) and the MEL byte-stream (length Scup bytes). The bottom segment is the HT Refinement segment, which consists of the SigProp byte-stream and the MagRef byte-stream. The total length of the HT Cleanup segment is Lcup bytes, and the total length of the HT Refinement segment is Lref bytes. The diagram also shows the VLC byte-stream following the MEL byte-stream.
+
+Figure 1 – HT segments and their byte-streams
+
+The HT cleanup segment:
+
+- shall have length  $L_{cup}$  such that  $2 \leq L_{cup} < 65535$ ;
+- shall not contain any consecutive pair of bytes whose value, as a big-endian 16-bit unsigned integer, exceeds  $0xFF8F$ ;
+- shall not terminate with a byte whose value is  $0xFF$ .
+
+The HT refinement segment:
+
+- shall have length  $L_{ref}$  satisfying  $0 \leq L_{ref} < 2047$ ;
+- shall also contain no consecutive pair of bytes whose value, as a big-endian 16-bit unsigned integer, exceeds  $0xFF8F$ ;
+- shall not terminate with a byte whose value is  $0xFF$ .
+
+The suffix length  $Scup$  is found from the last two bytes of the HT cleanup segment as follows:
+
+$$Scup = (16 \times Dcup[Lcup-1]) + (Dcup[Lcup-2] \& 0x0F)$$
+
+where  $Dcup[n]$  denotes byte  $n$  of the HT cleanup segment, and where  $n$  takes value from 0 to  $Lcup-1$ .
+
+After  $Scup$  is recovered from its last two bytes,  $Dcup[n]$  is accessed using the following procedure:
+
+---
+
+```
+
+Procedure: modDcup
+Returns: Modified Dcup array
+State: Dcup, pos
+
+```
+
+```
+
+if (pos == Lcup - 1)
+    return 0xFF
+else if (pos == Lcup - 2)
+    return Dcup[pos] | 0x0F
+else
+    return Dcup[pos]
+
+```
+
+---
+
+NOTE 2 – This procedure overwrites the last byte and the four least-significant bits (LSBs) of the second-last byte of the HT cleanup segment with 1s.
+
+The value of  $Scup$  obtained in this way, shall satisfy:
+
+$$2 \leq Scup \leq \min(Lcup, 4079)$$
+
+Furthermore, the codestream shall be constructed such that, if  $Scup < Lcup$ , so that  $Pcup > 0$ , byte  $Pcup-1$  of the HT cleanup segment shall not have the value  $0xFF$ .
+
+NOTE 3 – The `importMagSgnBit` procedure in clause 7.1.2 effectively synthesizes a byte equal to  $0xFF$  to replace any byte equal to  $0xFF$  that might have been discarded during encoding to satisfy this constraint.
+
+Details of the procedures to be used in recovering each bit-stream from its respective byte-stream are provided in clauses 7.1.2 to 7.1.6.
+
+Similar to the HT cleanup segment,  $Dref[n]$  denotes byte  $n$  of the HT refinement segment, where  $n$  takes values from 0 to  $Lref-1$ , except that no modification is made to the bytes of the HT refinement segment.
+
+The procedure `error()` denotes a state resulting from a codestream that does not conform to this specification, and for which behaviour is undefined.
+
+### 7.1.2 Magsgn bit-stream recovery
+
+HT MagSgn bits are retrieved from the HT MagSgn byte-stream, as required by other elements of the decoding procedure, using the `importMagSgnBit` procedure in the following. This procedure is part of a state machine with state variables `MS_pos`, `MS_bits`, `MS_tmp` and `MS_last` that are initialized using the `initMS` procedure, prior to first use of the `importMagSgnBit` procedure for an HT code-block.
+
+---
+
+```
+
+Procedure: initMS
+State: MS_pos, MS_bits, MS_tmp, MS_last
+
+MS_pos = 0
+MS_bits = 0
+
+MS_tmp = 0
+MS_last = 0
+
+```
+
+---
+
+```
+
+Procedure: importMagSgnBit
+Returns: next MagSgn bit
+State: MS_pos, MS_bits, MS_tmp, MS_last
+
+if (MS_bits == 0)
+    MS_bits = (MS_last == 0xFF)? 7 : 8
+    if (MS_pos < Pcup)
+        MS_tmp = modDcup(Dcup, MS_pos)
+        if ((MS_tmp & (1<<MS_bits)) != 0)
+            error()
+    else if (MS_pos == Pcup)
+        MS_tmp = 0xFF
+    else
+        error()
+    MS_last = MS_tmp
+    MS_pos = MS_pos + 1
+
+bit = MS_tmp & 1
+MS_tmp = MS_tmp >> 1
+MS_bits = MS_bits - 1
+
+return bit
+
+```
+
+---
+
+NOTE 1 – These procedures effectively unpack bits from the HT MagSgn byte-stream in little-endian order, skipping over stuffing bits that appear in the MSB position of any byte that follows a byte equal to 0xFF.
+
+NOTE 2 – The value of `Pcup` can be as small as 0.
+
+NOTE 3 – The procedure in the foregoing effectively appends at most one byte equal to 0xFF to the HT MagSgn byte-stream, which is sufficient to allow recovery of all required HT MagSgn bits if the codestream conforms to this Specification.
+
+NOTE 4 – The `importMagSgnBit` procedure is designed such that the MSB of a byte that follows a byte equal to `0xFF` is 0, unless that byte does not contribute to the `MagSgn` bit-stream. This is intended to simplify decoder implementations.
+
+### 7.1.3 MEL bit-stream recovery
+
+MEL bits are retrieved from the MEL byte-stream, as required by other elements of the decoding procedure, using the `importMELBit` procedure in the following. This procedure is part of a state machine with state variables `MEL_pos`, `MEL_bits`, `MEL_tmp` that are initialized using the `initMEL` procedure, prior to first use of the `importMELBit` procedure for an HT code-block.
+
+---
+
+```
+
+Procedure: initMEL
+State: MEL_pos, MEL_bits, MEL_tmp
+
+MEL_pos = Pcup
+MEL_bits = 0
+
+MEL_tmp = 0
+
+```
+
+---
+
+```
+
+Procedure: importMELBit
+Returns: next MEL bit
+State: MEL_pos, MEL_bits, MEL_tmp
+
+if (MEL_bits == 0)
+    MEL_bits = (MEL_tmp == 0xFF) ? 7 : 8
+    if (MEL_pos < Lcup)
+        MEL_tmp = modDcup(Dcup, MEL_pos)
+        MEL_pos = MEL_pos + 1
+    else
+        MEL_tmp = 0xFF
+MEL_bits = MEL_bits - 1
+bit = (MEL_tmp >> MEL_bits) & 1
+return bit
+
+```
+
+---
+
+NOTE – These procedures effectively unpack bits from the MEL byte-stream in big-endian order, skipping over stuffing bits that appear in the MSB position of any byte that follows a byte equal to `0xFF`.
+
+### 7.1.4 HT VLC bit-stream recovery
+
+HT VLC bits are retrieved from the HT VLC byte-stream, as required by other elements of the decoding procedure, using the `importVLCBit` procedure in the following. This procedure is part of a state machine with state variables `VLC_pos`, `VLC_bits`, `VLC_tmp` and `VLC_last` that are initialized using the `initVLC` procedure in the following, prior to first use of the `importVLCBit` procedure for an HT code-block.
+
+---
+
+```
+
+Procedure: initVLC
+State: VLC_pos, VLC_bits, VLC_tmp, VLC_last
+
+VLC_pos = Lcup-3
+VLC_last = modDcup(Dcup, Lcup-2)
+VLC_tmp = VLC_last >> 4
+VLC_bits = ((VLC_tmp & 7) < 7) ? 4 : 3
+
+```
+
+---
+
+---
+
+```
+
+Procedure: importVLCBit
+Returns: next VLC bit
+State: VLC_pos, VLC_bits, VLC_tmp, VLC_last
+
+if (VLC_bits == 0)
+    if (VLC_pos >= Pcup)
+        VLC_tmp = modDcup(Dcup, VLC_pos)
+    else
+        error()
+    VLC_bits = 8
+    if (VLC_last > 0x8F) and ((VLC_tmp & 0x7F) == 0x7F)
+        VLC_bits = 7
+    VLC_last = VLC_tmp
+    VLC_pos = VLC_pos - 1
+bit = VLC_tmp & 1
+VLC_tmp = VLC_tmp >> 1
+VLC_bits = VLC_bits - 1
+return bit
+
+```
+
+---
+
+NOTE – These procedures effectively unpack bits from the HT VLC byte-stream in little-endian order, while consuming bytes in reverse order, skipping over stuffing bits that appear in the MSB position of any byte whose 7 LSBs are all 1s if the byte that was last consumed was larger than 0x8F, and also skipping over the 12 bits that were replaced with 1s after using them to find the Scup value.
+
+### 7.1.5 HT SigProp bit-stream recovery
+
+If  $Z\_blk$  is greater than or equal to 2, HT SigProp bits are retrieved from the HT SigProp byte-stream, as required by other elements of the decoding procedure, using the `importSigPropBit` procedure in the following. This procedure is part of a state machine with state variables `SP_pos`, `SP_bits`, `SP_tmp` and `SP_last` that are initialized using the `initSP` procedure in the following, prior to first use of the `importSigPropBit` procedure for an HT code-block.
+
+---
+
+```
+
+Procedure: initSP
+State: SP_pos, SP_bits, SP_tmp, SP_last
+
+SP_pos = 0
+SP_bits = 0
+
+SP_tmp = 0
+SP_last = 0
+
+```
+
+---
+
+---
+
+```
+
+Procedure: importSigPropBit
+Returns: next SigProp bit
+State: SP_pos, SP_bits, SP_tmp, SP_last
+
+if (SP_bits == 0)
+    SP_bits = (SP_last == 0xFF) ? 7 : 8
+    if (SP_pos < Lref)
+        SP_tmp = Dref[SP_pos]
+        SP_pos = SP_pos + 1
+        if ((SP_tmp & (1<<SP_bits)) != 0)
+            error()
+    else
+        SP_tmp = 0
+    SP_last = SP_tmp
+bit = SP_tmp & 1
+SP_tmp = SP_tmp >> 1
+SP_bits = SP_bits - 1
+return bit
+
+```
+
+---
+
+NOTE 1 – These procedures are similar to those used to import bits from the HT MagSgn byte-stream, except that a separate set of state variables is used, and any bytes required from beyond the *Dref* buffer are taken to be 0 – no byte equal to 0xFF is synthesized by the decoder.
+
+NOTE 2 – The *importSigPropBit* procedure is designed such that the MSB of a byte that follows a byte equal to 0xFF is 0, unless that byte is not involved in the SigProp decoding process. This property can simplify decoder implementations.
+
+### 7.1.6 HT MagRef bit-stream recovery
+
+If *Z\_blk* is equal to 3, HT MagRef bits are retrieved from the HT MagRef byte-stream, as required by other elements of the decoding procedure, using the *importMagRefBit* procedure in the following. This procedure is part of a state machine with state variables *MR\_pos*, *MR\_bits*, *MR\_tmp* and *MR\_last* that are initialized using the *initMR* procedure in the following, prior to first use of the *importMagRefBit* procedure for an HT code-block.
+
+---
+
+```
+
+Procedure: initMR
+State: MR_pos, MR_bits, MR_tmp, MR_last
+
+MR_pos = Lref - 1
+MR_bits = 0
+MR_last = 0xFF
+MR_tmp = 0
+
+```
+
+---
+
+---
+
+```
+
+Procedure: importMagRefBit
+Returns: next HT MagRef bit
+State: MR_pos, MR_bits, MR_tmp, MR_last
+
+if (MR_bits == 0)
+    if (MR_pos >= 0)
+        MR_tmp = Dref[MR_pos]
+        MR_pos = MR_pos - 1
+    else
+        MR_tmp = 0
+    MR_bits = 8
+    if (MR_last > 0x8F) and ((MR_tmp & 0x7F) == 0x7F)
+        MR_bits = 7
+    MR_last = MR_tmp
+bit = MR_tmp & 1
+MR_tmp = MR_tmp >> 1
+MR_bits = MR_bits - 1
+return bit
+
+```
+
+---
+
+NOTE – These procedures are similar to those used to import bits from the VLC byte-stream, except that there are no initial bits to skip and the initialization conditions are such that the MSB of the last byte in the HT MagRef byte-stream will be skipped if its seven LSBs are all 1. Also, any bytes required from before the start of the Dref buffer are taken to be 0.
+
+## 7.2 Quad-based scanning pattern
+
+Figure 2 illustrates the quad-based scanning pattern that is followed when decoding an HT cleanup coding pass. The HT code-block samples are arranged within an array of quads where  $Q_W$  is the width of the code-block, measured in quads,  $Q_H$  is the height of the code-block measured in quads, and
+
+$$Q_W = \left\lceil \frac{W_{blk}}{2} \right\rceil$$
+
+$$Q_H = \left\lceil \frac{H_{blk}}{2} \right\rceil$$
+
+where  $W_{blk}$  and  $H_{blk}$  are the width and height of the HT code-block, measured in samples.
+
+If  $W_{blk}$  is not divisible by 2, the HT code-block is padded with an extra column of samples on the right, so that each quad spans two sample columns. Similarly, if  $H_{blk}$  is not divisible by 2, the HT code-block is padded with an extra row of samples on the bottom, so that each quad spans two sample rows and includes exactly four samples. All padded samples shall have output values equal to 0.
+
+![Figure 2: Quad-based scanning pattern. The diagram shows a sequence of quads (quad 0, quad 1, ..., quad Q_W - 1, quad Q_W, quad Q_W + 1) arranged in a grid. Each quad is a 2x2 block of samples. The scanning pattern is indicated by arrows: a solid arrow from the top-left sample of one quad to the top-left sample of the next quad in the sequence, and a dashed arrow from the bottom-right sample of one quad to the top-left sample of the next quad in the sequence. The quads are labeled 'quad 0', 'quad 1', ..., 'quad Q_W - 1', 'quad Q_W', and 'quad Q_W + 1'. The diagram is labeled T.814(19)_F02.](a7c51c18111139f9aca2805114108565_img.jpg)
+
+Figure 2: Quad-based scanning pattern. The diagram shows a sequence of quads (quad 0, quad 1, ..., quad Q\_W - 1, quad Q\_W, quad Q\_W + 1) arranged in a grid. Each quad is a 2x2 block of samples. The scanning pattern is indicated by arrows: a solid arrow from the top-left sample of one quad to the top-left sample of the next quad in the sequence, and a dashed arrow from the bottom-right sample of one quad to the top-left sample of the next quad in the sequence. The quads are labeled 'quad 0', 'quad 1', ..., 'quad Q\_W - 1', 'quad Q\_W', and 'quad Q\_W + 1'. The diagram is labeled T.814(19)\_F02.
+
+Figure 2 – Quad-based scanning pattern used in the HT cleanup pass
+
+Throughout this clause, the symbol  $q$  is used to identify quads, as an index that takes values in the range
+
+$$0 \leq q < QW \times QH$$
+
+Following the quad-based scan of Figure 2, locations  $n$  within the HT code-block take values in the range
+
+$$0 \leq n < 4 \times QW \times QH$$
+
+which can also be written as
+
+$$n = 4q + j$$
+
+where:
+
+$j = 0$  identifies the top-left sample within its quad;
+
+$j = 1$  identifies the bottom-left sample within its quad;
+
+$j = 2$  identifies the top-right sample within its quad; and
+
+$j = 3$  identifies the bottom-right sample within its quad.
+
+## 7.3 HT cleanup decoding algorithm
+
+### 7.3.1 Overview
+
+Figure 3 illustrates the operation of the HT cleanup decoding algorithm.
+
+![Figure 3: Block diagram of the HT cleanup decoding algorithm. The diagram shows a sequence of processing blocks B1 through B12. A large green block M1 is on the left, receiving inputs D1, D2, D3, D4, and D5. Block B1 receives D1 and outputs AZC(c_q = 0) to B2. Block B2 outputs s_{q1,q2}^{mel} to B3 and N1 to B7. Block B3 receives c_q from B1 and outputs sigma_{q1} to B4 and epsilon_q^k, epsilon_q^1 to B6. Block B4 outputs gamma_q to B5. Block B5 outputs kappa_q to B6. Block B6 outputs m_n and i_n to B8, and u_q to B7. Block B7 outputs u_q^{off} to B3 and S1 to B8. Block B8 outputs D4 and D5 to M1, and C2 to B10. Block B9 receives C1 and outputs C2 to B10 and C3 to B11. Block B10 outputs C4 to B12. Block B11 outputs C3 to B12. Block B12 outputs C4 to B7. A dashed line labeled S1 connects B7 and B8. The diagram is labeled T.814(19)_F03 at the bottom right.](e518bff13dc73675afd211dbea636c29_img.jpg)
+
+Figure 3: Block diagram of the HT cleanup decoding algorithm. The diagram shows a sequence of processing blocks B1 through B12. A large green block M1 is on the left, receiving inputs D1, D2, D3, D4, and D5. Block B1 receives D1 and outputs AZC(c\_q = 0) to B2. Block B2 outputs s\_{q1,q2}^{mel} to B3 and N1 to B7. Block B3 receives c\_q from B1 and outputs sigma\_{q1} to B4 and epsilon\_q^k, epsilon\_q^1 to B6. Block B4 outputs gamma\_q to B5. Block B5 outputs kappa\_q to B6. Block B6 outputs m\_n and i\_n to B8, and u\_q to B7. Block B7 outputs u\_q^{off} to B3 and S1 to B8. Block B8 outputs D4 and D5 to M1, and C2 to B10. Block B9 receives C1 and outputs C2 to B10 and C3 to B11. Block B10 outputs C4 to B12. Block B11 outputs C3 to B12. Block B12 outputs C4 to B7. A dashed line labeled S1 connects B7 and B8. The diagram is labeled T.814(19)\_F03 at the bottom right.
+
+B1: Compute contexts, as described in clause 7.3.5.
+
+B2: Decode MEL symbols, as described in clause 7.3.3.
+
+B3: Decode CxtVLC codewords, as described in clause 7.3.5.
+
+B4: Compute  $\gamma_q$  from  $\rho_q$ , as described in clause 7.3.7.
+
+B5: Form exponent predictors, as described in clause 7.3.7.
+
+B6: Compute MagSgn bit counts  $m_n$  and implicit-1 flags  $i_n$ , as described in clauses 7.3.2 and 7.3.8.
+
+B7: Decode U-VLC codewords, as described in clause 7.3.6.
+
+B8: Decode MagSgn values, as described in clause 7.3.8.
+
+B9: Extract byte-streams from HT cleanup segment, as described in clause 7.1.1.
+
+B10: Extract MagSgn bit-stream from bit-stuffed MagSgn byte-stream, as described in clause 7.1.2.
+
+B11: Extract MEL bit-stream from bit-stuffed MEL byte-stream, as described in clause 7.1.3.
+
+B12: Extract VLC bit-stream from bit-stuffed VLC byte-stream, as described in clause 7.1.4.
+
+C1: HT cleanup segment.
+
+C2: MagSgn bit-stream.
+
+C3: MEL bit-stream.
+
+C4: VLC bit-stream.
+
+D1: Retrieved neighbouring significance patterns.  
+D2: Generated significance patterns.  
+D3: Retrieved neighbouring magnitude exponents.  
+D4: Generated magnitude exponents.  
+D5: Generated code-block samples.  
+M1: Storage for code-block samples and derived quantities, with quad-based scanning, as described in clause 7.2.  
+N1: First line-pair of code-block only.  
+S1: De-interleave quad-pair VLC bits, as described in clause 7.3.4
+
+**Figure 3 – Operation of the HT cleanup decoding algorithm (informative). Each block in the diagram refers to the clause that defines its operation**
+
+### 7.3.2 Significance, exponents, predictors, MagSgn values and EMB pattern bits
+
+This clause introduces notation and formulae that are used to describe the block-decoding procedures associated with the HT cleanup coding pass, as presented in clauses 7.3.3 to 7.3.8.
+
+The HT cleanup coding pass produces magnitude values  $\mu_n$ , along with sign values  $s_n \in \{0,1\}$  for each sample of the HT code-block, where  $s_n = 1$  corresponds to a negative value, and all values with zero magnitude shall have  $s_n = 0$ .
+
+Sample magnitudes shall satisfy
+
+$$0 \leq \mu_n < 2^{74}$$
+
+NOTE 1 – The upper bound here comes from the combination of a) the maximum number of bit-planes (37) for any given sub-band (see clause B.10.5 of Rec. ITU-T T.800 | ISO/IEC 15444-1), and b) the maximum value of  $SP_{rgn}$  (37) allowed in HTJ2K codestreams (see clause A.5).
+
+The significance of a sample  $\sigma_n \in \{0,1\}$  identifies whether its magnitude is 0; it satisfies:
+
+$$\sigma_n = \begin{cases} 0 & \text{if } \mu_n = 0 \\ 1 & \text{if } \mu_n > 0 \end{cases}$$
+
+Padded samples that have been added to HT code-blocks with odd width or height, as explained in clause 7.2, shall have  $\sigma_n = 0$ . The significance of an entire quad  $q$  is denoted  $\bar{\sigma}_q \in \{0,1\}$ , indicating whether any sample in the quad is significant, and satisfies:
+
+$$\bar{\sigma}_q = \sigma_{4q} \mid \sigma_{4q+1} \mid \sigma_{4q+2} \mid \sigma_{4q+3}$$
+
+The significance pattern for a quad  $q$ , denoted  $\rho_q$ , is a 4-bit value comprised of the 1-bit significance values associated with each of the quad's samples; that is,
+
+$$\rho_q = \sigma_{4q} + 2\sigma_{4q+1} + 4\sigma_{4q+2} + 8\sigma_{4q+3}$$
+
+For significant samples ( $\sigma_n = 1$ ) the magnitude and sign values are encapsulated within an HT MagSgn value  $v_n$  that is defined as follows:
+
+$$v_n = 2(\mu_n - 1) + s_n$$
+
+The magnitude exponent  $E_n$  for a sample is derived from its magnitude as follows:
+
+$$E_n = \min\{E \in \mathbb{N} \mid (2\mu_n - 1) < 2^E\}$$
+
+Table 1 provides a detailed elaboration of the relationship between sample magnitude  $\mu$  and exponent  $E$ . No magnitude exponent shall have a value larger than 75.
+
+**Table 1 – Mapping of sub-band sample magnitudes to magnitude exponents**
+
+| $\mu_p$                  | $E_p$ |
+|--------------------------|-------|
+| 0                        | 0     |
+| 1                        | 1     |
+| 2                        | 2     |
+| 3 to 4                   | 3     |
+| 5 to 8                   | 4     |
+| 9 to 16                  | 5     |
+| ...                      | ...   |
+| $2^{73} + 1$ to $2^{74}$ | 75    |
+
+For significant samples, the HT MagSgn value  $v_n$  is determined by unpacking  $m_n$  bits from the HT MagSgn bit-stream, as explained in clause 7.3.8 and adding  $i_n \cdot 2^{m_n}$ , where  $i_n \in \{0,1\}$ . For insignificant samples,  $m_n = 0$ , while for significant samples  $m_n$  is obtained by subtracting a 1-bit quantity  $k_n \in \{0,1\}$  from a common exponent bound  $U_q$  for the quad  $q$  to which location  $n$  belongs. These quantities are linked by the following relationships:
+
+$$m_n = \sigma_n \cdot U_q - k_n$$
+
+$$i_n \leq k_n \leq \sigma_n$$
+
+where the magnitude exponents of all samples in a quad  $q$  satisfy
+
+$$E_n \leq U_q \text{ for } n \in \{4q, 4q + 1, 4q + 2, 4q + 3\}$$
+
+The decoder determines the quad's  $U_q$  value by adding an unsigned residual value  $u_q$  to an exponent predictor  $\kappa_q$ .
+
+The value of  $u_q$  is decoded in two steps, the first of which decodes an "unsigned residual offset" value  $u_q^{\text{off}} \in \{0,1\}$  that indicates whether  $u_q$  is 0, while the second step decodes the value of  $u_q - 1$  for quads in which  $u_q^{\text{off}}=1$ , meaning that the unsigned residual is non-zero.
+
+The exponent max bound (EMB) pattern information for a quad  $q$  consists of two 4-bit patterns,  $\bar{\epsilon}_q^k$  and  $\bar{\epsilon}_q^1$ , whose bits are the quantities  $i_n$  and  $k_n$  introduced in the foregoing. That is,
+
+$$\bar{\epsilon}_q^k = k_{4q} + 2k_{4q+1} + 4k_{4q+2} + 8k_{4q+3}$$
+
+and
+
+$$\bar{\epsilon}_q^1 = i_{4q} + 2i_{4q+1} + 4i_{4q+2} + 8i_{4q+3}$$
+
+The significance pattern  $\rho_q$ , *EMB known bit* pattern  $\bar{\epsilon}_q^k$  and *EMB known-1* pattern  $\bar{\epsilon}_q^1$  are decoded together with  $u_q^{\text{off}}$ , based on a single variable length codeword for the quad  $q$ .
+
+In this Specification,  $\bar{\epsilon}_q^k$  and  $\bar{\epsilon}_q^1$  are both 0 if  $u_q^{\text{off}} = 0$ . Moreover, if  $u_q^{\text{off}} = 1$ , the value of  $U_q$  shall be equal to the maximum of the magnitude exponents  $E_n$ , of the quad's samples.
+
+NOTE 2 – The EMB patterns  $\bar{\epsilon}_q^k$  and  $\bar{\epsilon}_q^1$  provide information about whether individual magnitude exponents  $E_n$  are equal to the quad's maximum magnitude exponent. The variable length codewords for a quad may provide the decoder with EMB information for some, none or all samples in the quad; the *known bit* pattern  $\bar{\epsilon}_q^k$  identifies which samples have such information. The *known-1* pattern  $\bar{\epsilon}_q^1$  provides the EMB information itself; each bit  $i_n$  in this pattern is 1 if  $k_n = 1$  and  $E_n$  is equal to the maximum exponent for the quad.
+
+### 7.3.3 MEL symbol decoding procedure
+
+The HT cleanup coding pass decoding procedure involves at most one MEL symbol  $s_q^{\text{mel}}$  for each quad  $q$ , that is retrieved by decoding the MEL bit-stream using the `decodeMELSym` procedure in the following. This procedure is part of a state machine with state variables `MEL_k`, `MEL_run` and `MEL_one` that are initialized using the `initMELDecoder` procedure in the following, prior to first use of the `decodeMELSym` procedure for an HT code-block.
+
+The MEL decoding procedure uses an exponent table `MEL_E [ ]`, whose entries are listed in Table 2.
+
+---
+
+```
+
+Procedure: initMELDecoder
+State: MEL_k, MEL_run, MEL_one
+
+```
+
+```
+
+MEL_k = 0
+MEL_run = 0
+MEL_one = 0
+
+```
+
+---
+
+
+
+---
+
+```
+
+Procedure: decodeMELSym
+Returns: next MEL symbol  $s^{\text{mel}}$ 
+State: MEL_k, MEL_run, MEL_one
+
+```
+
+```
+
+if (MEL_run == 0) and (MEL_one == 0)
+    eval = MEL_E[MEL_k]
+    bit = importMELBit
+    if (bit == 1)
+        MEL_run = 1 << eval
+        MEL_k = min(12, MEL_k + 1)
+    else
+        MEL_run = 0
+        while (eval > 0)
+            bit = importMELBit
+            MEL_run = 2 * MEL_run + bit
+            eval = eval - 1
+        MEL_k = max(0, MEL_k - 1)
+        MEL_one = 1
+if (MEL_run > 0)
+    MEL_run = MEL_run - 1
+    return 0
+else
+    MEL_one = 0
+    return 1
+
+```
+
+---
+
+**Table 2 – MEL Exponent Table  $\text{MEL\_E}[k]$**
+
+| k | exponent MEL_E | k  | exponent MEL_E |
+|---|----------------|----|----------------|
+| 0 | 0              | 7  | 2              |
+| 1 | 0              | 8  | 2              |
+| 2 | 0              | 9  | 3              |
+| 3 | 1              | 10 | 3              |
+| 4 | 1              | 11 | 4              |
+| 5 | 1              | 12 | 5              |
+| 6 | 2              |    |                |
+
+### 7.3.4 Quad-pair interleaved decoding for the VLC bit-stream
+
+This clause describes the quad-pair interleaving structure that shall be followed when decoding bits from the VLC bit-stream to produce significance patterns  $\rho_g$ , unsigned residuals  $u_g$  and EMB patterns  $\bar{\epsilon}_q^k$  and  $\bar{\epsilon}_q^1$ . The decoding procedures themselves are described in clauses 7.3.5 and 7.3.6.
+
+Figure 4 illustrates the sequence of decoding steps. For each pair of horizontally adjacent quads, the variable length decoding procedure identified as CxtVLC is performed first, for each of the quads; as described in clause 7.3.5, this consumes between 0 and 7 bits from the VLC bit-stream. Next, the variable length U-VLC prefix decoding process is performed for each of the two quads. As described in clause 7.3.6, this consumes between 0 and 3 bits from the VLC bit-stream for each of the quads, and uniquely determines the number of U-VLC suffix bits that shall occur for each of the two quads. Any U-VLC suffix bits associated with the first quad in the pair are retrieved from the VLC bit-stream before those associated with the second quad. Finally, the decoder extracts any U-VLC extension bits for the quad-pair, extracting first the extension bits for the first quad in the pair and then the extension bits for the second quad in the pair. As explained in clause 7.3.6, the number of extension bits for a quad is 0 or 4, and is determined by the value of the corresponding U-VLC suffix.
+
+U-VLC extensions shall have zero length in cases where the sample magnitudes  $\mu_n$  cannot exceed  $2^{36}$ .
+
+EXAMPLE – If the parameter  $B$  specified in clause 8.7.3 is less than or equal to 36, a decoder can rely upon the fact that there will be no U-VLC extensions.
+
+![Figure 4: Quad-pair interleaving of VLC decoding steps. The diagram shows a sequence of quads: quad q = 2g and quad q = 2g+1. Each quad is represented by a 2x2 grid of cells. Below the quads, the decoding steps are listed in boxes: CxtVLC (0-7 bits), U-VLC prefix (0-3 bits), U-VLC suffix (0, 1 or 5 bits), and U-VLC ext (0 or 4 bits). Arrows indicate dependencies: solid blue arrows from CxtVLC to U-VLC prefix; solid red arrows from U-VLC prefix to U-VLC suffix; dashed red arrows from U-VLC suffix to U-VLC ext; and dashed green arrows from U-VLC ext back to U-VLC prefix. The diagram also shows that the U-VLC suffix of one quad is used as the U-VLC prefix for the next quad.](2eb23c2210154279f8013a1594fbcc5a_img.jpg)
+
+Figure 4: Quad-pair interleaving of VLC decoding steps. The diagram shows a sequence of quads: quad q = 2g and quad q = 2g+1. Each quad is represented by a 2x2 grid of cells. Below the quads, the decoding steps are listed in boxes: CxtVLC (0-7 bits), U-VLC prefix (0-3 bits), U-VLC suffix (0, 1 or 5 bits), and U-VLC ext (0 or 4 bits). Arrows indicate dependencies: solid blue arrows from CxtVLC to U-VLC prefix; solid red arrows from U-VLC prefix to U-VLC suffix; dashed red arrows from U-VLC suffix to U-VLC ext; and dashed green arrows from U-VLC ext back to U-VLC prefix. The diagram also shows that the U-VLC suffix of one quad is used as the U-VLC prefix for the next quad.
+
+**Figure 4 – Quad-pair interleaving of VLC decoding steps**  
+(Arrows identify dependencies)
+
+If  $\text{QW}$  is odd, the final quad-pair on each row only has a first quad. For such quad-pairs, the decoder shall not perform any of the decoding steps suggested in the foregoing for the missing second quad.
+
+### 7.3.5 Decoding of significance and EMB patterns and unsigned residual offsets
+
+This clause describes the context-adaptive variable length decoding procedure that is used to decode the significance pattern  $\rho_q$ , the unsigned residual offset  $u_q^{\text{off}}$  and the EMB patterns  $\bar{\epsilon}_q^k$  and  $\bar{\epsilon}_q^1$  for each quad  $q$ .
+
+The decoding procedure depends upon a context value  $c_q$  that is computed from the significance of a set of neighbouring samples, as shown in Figure 5.
+
+![Figure 5: Significance neighbourhood information used to form coding contexts c_q for quads found in non-initial (q ≥ QW) and initial (q < QW) line-pairs within a HT code-block. The diagram shows two scenarios. Left: Context neighbourhood when q ≥ QW. It shows a 2x2 grid of quads. The top row has quads with superscripts nw, n, ne, nf. The bottom row has quads with superscripts w, sw. The quad in the bottom row, second column is highlighted in orange and labeled 'quad-q'. A bracket below it is labeled ρ_q. Right: Context neighbourhood when q < QW. It shows a 2x2 grid of quads. The top row has quads with superscripts f, w. The bottom row has quads with superscripts sf, sw. The quad in the bottom row, second column is highlighted in orange and labeled 'quad-q'. A bracket below it is labeled ρ_q. Arrows indicate the flow from the left scenario to the right scenario.](812e188283162af0b54fb3e30ffee51b_img.jpg)
+
+Context neighbourhood when  $q \geq QW$                       Context neighbourhood when  $q < QW$
+
+T.814(19)\_F05
+
+Figure 5: Significance neighbourhood information used to form coding contexts c\_q for quads found in non-initial (q ≥ QW) and initial (q < QW) line-pairs within a HT code-block. The diagram shows two scenarios. Left: Context neighbourhood when q ≥ QW. It shows a 2x2 grid of quads. The top row has quads with superscripts nw, n, ne, nf. The bottom row has quads with superscripts w, sw. The quad in the bottom row, second column is highlighted in orange and labeled 'quad-q'. A bracket below it is labeled ρ\_q. Right: Context neighbourhood when q < QW. It shows a 2x2 grid of quads. The top row has quads with superscripts f, w. The bottom row has quads with superscripts sf, sw. The quad in the bottom row, second column is highlighted in orange and labeled 'quad-q'. A bracket below it is labeled ρ\_q. Arrows indicate the flow from the left scenario to the right scenario.
+
+**Figure 5 – Significance neighbourhood information used to form coding contexts  $c_q$  for quads found in non-initial ( $q \geq QW$ ) and initial ( $q < QW$ ) line-pairs within a HT code-block**
+
+The superscript labels (nw, n, ne, nf, w, sw, f, and sf) are used to identify the relevant neighbours
+
+The neighbours used in the first row of quads for the HT code-block, where  $q < QW$ , are denoted
+
+$$(\sigma_q^{sw}, \sigma_q^w, \sigma_q^{sf}, \sigma_q^f) = \begin{cases} (\sigma_{4q-1}, \sigma_{4q-2}, \sigma_{4q-3}, \sigma_{4q-4}) & \text{if } q > 0 \\ (0, 0, 0, 0) & \text{if } q = 0 \end{cases}$$
+
+and in this case the context value is computed as follows:
+
+$$c_q = (\sigma_q^f | \sigma_q^{sf}) + 2\sigma_q^w + 4\sigma_q^{sw} \quad (1)$$
+
+The neighbours used in non-initial quad rows of the HT code-block, where  $q \geq QW$ , are denoted
+
+$$\begin{aligned} \sigma_q^n &= \sigma_{4(q-QW)+1}, & \sigma_q^{ne} &= \sigma_{4(q-QW)+3}, \\ \sigma_q^{nw} &= \begin{cases} \sigma_{4(q-QW)-1} & \text{if } \text{mod}(q, QW) \neq 0 \\ 0 & \text{otherwise} \end{cases} & \text{and } \sigma_q^{nf} &= \begin{cases} \sigma_{4(q-QW)+5} & \text{if } \text{mod}(q+1, QW) \neq 0 \\ 0 & \text{otherwise} \end{cases} \end{aligned}$$
+
+and in this case the context value is computed as follows:
+
+$$c_q = (\sigma_q^{nw} | \sigma_q^n) + 2(\sigma_q^w | \sigma_q^{sw}) + 4(\sigma_q^{ne} | \sigma_q^{nf}) \quad (2)$$
+
+Quads  $q$  for which  $c_q = 0$  are identified as all zero context (AZC) quads and receive special treatment in the decoding process, which is represented by the `decodeSigEMB` procedure in the following. This procedure relies upon the `decodeMELSym` procedure, as well as a `decodeCxtVLC` procedure in the following, which is used for non-AZC quads and for AZC quads that are determined to be significant because the `decodeMELSym` procedure returns a 1.
+
+The `decodeCxtVLC` procedure itself is based on a separate prefix code for each context  $c_q$ . Prefix codes are further differentiated based on quad-type – i.e., whether the quad being decoded belongs to the first row of quads for the HT code-block ( $q < QW$ ) or not. Bits from the VLC bit-stream are imported using the `importVLCbit` procedure described in clause 7.1, until one of the codewords of the prefix code is matched, revealing the tuple  $(\rho_q, u_q^{\text{off}}, \bar{\epsilon}_q^k, \bar{\epsilon}_q^1)$  as the decoded result. Annex C provides the code tables `CxtVLC_table_0` and `CxtVLC_table_1`, corresponding to each quad-type. The function `test_match` returns true if a codeword prefix `cwd`, length `len` and context  $c_q$  match the  $w$ ,  $l_w$  and  $c_q$  fields of an entry in the table. The function `get_match` returns the  $(\rho_q, u_q^{\text{off}}, \bar{\epsilon}_q^k, \bar{\epsilon}_q^1)$  values from the matching entry.
+
+---
+
+```
+
+Procedure: decodeCxtVLC
+Input: quad index  $q$  and context  $c_q$ 
+Returns:  $(\rho_q, u_q^{\text{off}}, \bar{\epsilon}_q^k, \bar{\epsilon}_q^1)$  tuple for quad  $q$ 
+
+if ( $q < QW$ )
+    table = CxtVLC_table_0
+else
+    table = CxtVLC_table_1
+len = 1
+cwd = importVLCbit
+while (!test_match(table,  $c_q$ , cwd, len))
+    bit = importVLCbit
+    cwd = cwd | (bit << len)
+    len = len + 1
+ $(\rho_q, u_q^{\text{off}}, \bar{\epsilon}_q^k, \bar{\epsilon}_q^1) = \text{get\_match}(\text{table}, c_q, \text{cwd}, \text{len})$ 
+return  $(\rho_q, u_q^{\text{off}}, \bar{\epsilon}_q^k, \bar{\epsilon}_q^1)$ 
+
+```
+
+---
+
+
+
+---
+
+```
+
+Procedure: decodeSigEMB
+Input: quad index  $q$  and context  $c_q$ 
+Returns:  $(\rho_q, u_q^{\text{off}}, \bar{\epsilon}_q^k, \bar{\epsilon}_q^1)$  tuple for quad  $q$ 
+
+if ( $c_q == 0$ )
+    sym = decodeMELSym
+    if (sym == 0)
+        return  $(\rho_q, u_q^{\text{off}}, \bar{\epsilon}_q^k, \bar{\epsilon}_q^1) = (0,0,0,0)$ 
+ $(\rho_q, u_q^{\text{off}}, \bar{\epsilon}_q^k, \bar{\epsilon}_q^1) = \text{decodeCxtVLC}$ 
+return  $(\rho_q, u_q^{\text{off}}, \bar{\epsilon}_q^k, \bar{\epsilon}_q^1)$ 
+
+```
+
+---
+
+### 7.3.6 Decoding of unsigned residuals
+
+This clause describes the procedure used to decode the unsigned residual value  $u_q$  for a quad  $q$  in which the decoded value of  $u_q^{\text{off}}$  is 1. If  $u_q^{\text{off}} = 0$ , the unsigned residual  $u_q$  is 0 and no further unsigned residual decoding is required for the quad.
+
+When  $u_q^{\text{off}} = 1$ , the value of  $u_q$  is decoded with the aid of a U-VLC variable length decoding procedure that involves up to three steps. The first step is to decode the variable length U-VLC prefix. For certain prefix values, a second step is required, in which a U-VLC suffix is decoded. The number of U-VLC suffix bits that need to be decoded from the VLC bit-stream is determined entirely by the U-VLC prefix value. If the U-VLC suffix value is greater than 27, a third step is required, in which 4 bits are imported from the VLC bit-stream to form a U-VLC extension code. The U-VLC prefix, suffix and extension decoding steps for each pair of quads are interleaved, as described in clause 7.3.4.
+
+Table 3 provides the complete U-VLC code that is used as-is to decode the  $u_q$  value for quads belonging to a non-initial line-pair of the HT code-block – i.e., whenever  $q \geq QW$ . The same method is used to decode the  $u_q$  values for quad-pairs belonging to the initial line-pair of the HT code-block, where quads  $q_1$  and  $q_2$  of the quad-pair do not both have  $u_{q_1}^{\text{off}} = 1$  and  $u_{q_2}^{\text{off}} = 1$ . The final decoded value for  $u_q$  in these cases is:
+
+$$u = u\_pfx + u\_sfx + 4 * u\_ext \quad (3)$$
+
+where  $u\_pfx$  is decoded using the `decodeUPrefix` procedure, then  $u\_sfx$  is decoded using the `decodeUSuffix` procedure, then  $u\_ext$  is decoded using the `decodeUEExtension` procedure, all of which appear in the following.
+
+**Table 3 – U-VLC code used to encode unsigned residuals  $u > 0$ . The prefix string here is matched against bits from the VLC bit-stream from left to right, consuming  $l_p(u)$  bits. The suffix and extension words are unsigned integers with  $l_s(u)$  and  $l_e(u)$  bits that are imported from the VLC bit-stream in little-endian order (i.e., least significant bit first)**
+
+| $u$ | Prefix |          | Suffix                      | Extension                    | $l_p(u)$ | $l_s(u)$ | $l_e(u)$ | $l_p(u) + l_s(u) + l_e(u)$ |
+|-----|--------|----------|-----------------------------|------------------------------|----------|----------|----------|----------------------------|
+|     | cwd    | $u\_pfx$ | $u\_sfx$                    | $u\_ext$                     |          |          |          |                            |
+| 1   | "1"    | 1        | --                          | --                           | 1        | 0        | 0        | 1                          |
+| 2   | "01"   | 2        | --                          | --                           | 2        | 0        | 0        | 2                          |
+| 3   | "001"  | 3        | $(u - 3)$                   | --                           | 3        | 1        | 0        | 4                          |
+| 4   | "001"  | 3        | $(u - 3)$                   | --                           | 3        | 1        | 0        | 4                          |
+| 5   | "000"  | 5        | $(u - 5)$                   | --                           | 3        | 5        | 0        | 8                          |
+| 6   | "000"  | 5        | $(u - 5)$                   | --                           | 3        | 5        | 0        | 8                          |
+| ... | ...    | ...      | ...                         | --                           | ...      | ...      | ...      | ...                        |
+| 32  | "000"  | 5        | 27                          | --                           | 3        | 5        | 0        | 8                          |
+| 33  | "000"  | 5        | $28 + \text{mod}((u-33),4)$ | $\lfloor (u - 33)/4 \rfloor$ | 3        | 5        | 4        | 12                         |
+| 34  | "000"  | 5        | $28 + \text{mod}((u-33),4)$ | $\lfloor (u - 33)/4 \rfloor$ | 3        | 5        | 4        | 12                         |
+| ... | ...    | ...      | ...                         | ...                          | ...      | ...      | ...      | 12                         |
+| 74  | "000"  | 5        | 29                          | 10                           | 3        | 5        | 4        | 12                         |
+
+---
+
+Procedure: `decodeUPrefix`  
+Returns: U-VLC prefix value  $u\_pfx$
+
+```
+
+bit = importVLCBit
+if (bit == 1) return 1
+bit = importVLCBit
+if (bit == 1) return 2
+bit = importVLCBit
+return (bit == 1)? 3:5
+
+```
+
+---
+
+---
+
+```
+
+Procedure: decodeUSuffix
+Input: U-VLC prefix value u_pfx
+Returns: U-VLC suffix value u_sfx
+
+```
+
+```
+
+if (u_pfx < 3) return 0
+val = importVLCBit
+if (u_pfx == 3) return val
+for (i=1; i < 5; i++)
+    bit = importVLCBit
+    val = val + (bit << i)
+return val
+
+```
+
+---
+
+
+
+---
+
+```
+
+Procedure: decodeUEExtension
+Input: U-VLC suffix value u_sfx
+Returns: U-VLC extension value u_ext
+
+```
+
+```
+
+if (u_sfx < 28) return 0
+val = importVLCBit
+for (i=1; i < 4; i++)
+    bit = importVLCBit
+    val = val + (bit << i)
+return val
+
+```
+
+---
+
+For quads belonging to the first line-pair of the HT code-block (i.e., when  $q < QW$ ), the process used to decode a non-zero  $u_q$  value (i.e., when  $u_q^{\text{off}}$  is 1) is modified where quads  $q_1$  and  $q_2$  of a quad-pair are found to have both  $u_{q_1}^{\text{off}} = 1$  and  $u_{q_2}^{\text{off}} = 1$ . In this case, a single MEL symbol  $s_{q_1q_2}^{\text{mel}}$  is decoded for the quad-pair by invoking the `decodeMELSym` procedure. For clarity, this is done after the `decodeCxtVLC` steps have been performed for the quad-pair to which quad  $q$  belongs. The decoding of  $u_{q_1}$  and  $u_{q_2}$  then proceeds in one of two ways, depending upon the value of the decoded MEL symbol  $s_{q_1q_2}^{\text{mel}}$ . If  $s_{q_1q_2}^{\text{mel}} = 1$ , the `decodeUPrefix`, `decodeUSuffix` and `decodeUEExtension` procedures are used to decode prefix, suffix and extension values  $u\_pfx$ ,  $u\_sfx$  and  $u\_ext$ , exactly as in the foregoing, for each quad, and the decoded  $u_q$  values are found from
+
+$$u = 2 + u\_pfx + u\_sfx + 4 * u\_ext \quad (4)$$
+
+Otherwise, if  $s_{q_1q_2}^{\text{mel}} = 0$ , the first quad's unsigned residual  $u_{q_1}$  is found using Formula (3), but decoding of the second quad's unsigned residual  $u_{q_2}$  depends upon the decoded  $u_{q_1}$  values. Specifically, where  $u_{q_1} > 2$ , the U-VLC prefix decoding step for  $u_{q_2}$  is replaced by using `importVLCBit` directly to import a single bit  $u_{\text{bit}}$  from the VLC bit-stream and setting  $u\_pfx = u_{\text{bit}} + 1$ ; the decoded  $u_{q_2}$  value is then
+
+$$u_{q_2} = u_{\text{bit}} + 1$$
+
+Where  $u_{q_1} \leq 2$  the decoding of  $u_{q_2}$  proceeds in the same way as  $u_{q_1}$ , using Formula (3).
+
+NOTE – When  $u_{q_1}^{\text{off}} = u_{q_2}^{\text{off}} = 1$  and  $s_{q_1q_2}^{\text{mel}} = 0$ , the condition  $u_{q_1} > 2$  means that the `decodeUPrefix` procedure for the first quad returns  $u\_pfx > 2$ , or equivalently, that the first quad's U-VLC prefix has length 3.
+
+### 7.3.7 Determination of predictors and exponent bounds
+
+This clause describes the procedure by which a decoder computes exponent predictors  $\kappa_q$  for each quad  $q$ , and combines these with the unsigned residual values  $u_q$  to deduce exponent bounds  $U_q$ .
+
+For the first row of quads in an HT code-block ( $q < QW$ ), the exponent predictor satisfies
+
+$$\kappa_q = 1$$
+
+For all other quads,  $\kappa_q$  is computed from the magnitude exponents of neighbouring decoded samples from the preceding line in the HT code-block, as illustrated in Figure 6. Specifically, the exponents that are used are:
+
+$$E_q^n = E_{4(q-\mathcal{QW})+1}, \quad E_q^{ne} = E_{4(q-\mathcal{QW})+3},$$
+
+$$E_q^{nw} = \begin{cases} E_{4(q-\mathcal{QW})-1} & \text{if } \text{mod}(q, \mathcal{QW}) \neq 0 \\ 0 & \text{otherwise} \end{cases} \text{ and } E_q^{nf} = \begin{cases} E_{4(q-\mathcal{QW})+5} & \text{if } \text{mod}(q+1, \mathcal{QW}) \neq 0 \\ 0 & \text{otherwise} \end{cases}$$
+
+The decoder derives these exponents from decoded sample magnitudes  $\mu_n$ , using the procedure expounded via Table 1.
+
+![Figure 6: Neighbourhood information used to form exponent predictors for quads in non-initial line-pairs of a block. The diagram shows a grid of quads. The top row is labeled 'lines 2m-2, 2m-1' and the bottom row is labeled 'lines 2m, 2m+1'. The middle quad in the top row is labeled E_q^{nw}. The middle quad in the bottom row is labeled E_q^n and E_q^{ne}. The rightmost quad in the top row is labeled E_q^{nf}. The bottom row of the middle quad is shaded orange and labeled 'quad q' with a blue bracket underneath. The label 'T.814(19)_F06' is at the bottom right.](a0739aaf13fa5a632d4faa830f6b2708_img.jpg)
+
+Figure 6: Neighbourhood information used to form exponent predictors for quads in non-initial line-pairs of a block. The diagram shows a grid of quads. The top row is labeled 'lines 2m-2, 2m-1' and the bottom row is labeled 'lines 2m, 2m+1'. The middle quad in the top row is labeled E\_q^{nw}. The middle quad in the bottom row is labeled E\_q^n and E\_q^{ne}. The rightmost quad in the top row is labeled E\_q^{nf}. The bottom row of the middle quad is shaded orange and labeled 'quad q' with a blue bracket underneath. The label 'T.814(19)\_F06' is at the bottom right.
+
+**Figure 6 – Neighbourhood information used to form exponent predictors for quads in non-initial line-pairs of a block**
+
+These exponents are converted to an exponent predictor  $\kappa_q$ , using
+
+$$\kappa_q = \max\{1, \gamma_q \cdot (\max\{E_q^{nw}, E_q^n, E_q^{ne}, E_q^{nf}\} - 1)\}, \quad (5)$$
+
+where  $\gamma_q \in \{0,1\}$  indicates whether quad  $q$  has more than one significant sample. Specifically,
+
+$$\gamma_q = \begin{cases} 0 & \text{if } \rho_q \in \{0,1,2,4,8\} \\ 1 & \text{otherwise} \end{cases} \quad (6)$$
+
+The exponent bound  $U_q$  for quad  $q$  is obtained from
+
+$$U_q = \kappa_q + u_q$$
+
+The decoded unsigned residual  $u_q$  shall have the smallest non-negative value that is consistent with the constraint
+
+$$U_q \geq E_n \text{ for each } n \in \{4q, 4q+1, 4q+2, 4q+3\}$$
+
+where  $E_n$  is the magnitude exponent associated with each decoded sample magnitude  $\mu_n$ .
+
+### 7.3.8 Unpacking the HT MagSgn bit-stream
+
+Using the exponent bound  $U_q$ , significance pattern  $\rho_q$  and EMB patterns  $\bar{\epsilon}_q^k$  and  $\bar{\epsilon}_q^1$  for each quad, the decoder determines the number of bits  $m_n$  according to
+
+$$m_n = \sigma_n \cdot U_q - k_n \text{ for each } n \in \{4q, 4q+1, 4q+2, 4q+3\}$$
+
+and then recovers the HT MagSgn values for each sample, following the scanning pattern in Figure 2, by using procedure `decodeMagSgnValue` that appears in the following. Here,  $\sigma_n$ ,  $k_n$  and  $i_n$  are the individual bits of the 4-bit patterns  $\rho_q$ ,  $\bar{\epsilon}_q^k$  and  $\bar{\epsilon}_q^1$ , respectively, as explained in clause 7.3.2.
+
+---
+
+```
+
+Procedure: decodeMagSgnValue
+Input: number of mag-sign bits  $m_n$  and known-1 value  $i_n$  for a sample  $n$ 
+Returns: HT MagSgn value  $v_n$  for the sample
+
+```
+
+---
+
+```
+
+val = 0
+for (i=0; i <  $m_n$ ; i++)
+    bit = importMagSgnBit
+    val = val + (bit << i)
+val = val + ( $i_n$  <<  $m_n$ )
+return val
+
+```
+
+---
+
+From the decoded HT MagSgn values  $v_n$ , the decoder recovers magnitude values  $\mu_n$  and sign bits  $s_n$  as follows:
+
+$$\mu_n = \begin{cases} \lfloor v_n/2 \rfloor + 1 & \text{if } m_n \neq 0 \\ 0 & \text{if } m_n = 0 \end{cases} \quad s_n = \begin{cases} \text{mod}(v_n, 2) & \text{if } m_n \neq 0 \\ 0 & \text{if } m_n = 0 \end{cases}$$
+
+NOTE – Before the `decodeMagSgnValue` procedure can be used to reconstruct HT MagSgn values within a current non-initial row of quads, samples from the preceding row of quads must be decoded and at least some of them converted to magnitude exponents, so as to enable computation of  $\kappa_q$  and  $U_q$  values for the current non-initial row of quads.
+
+## 7.4 HT SigProp decoding procedure
+
+This clause describes the procedure for decoding an HT SigProp coding pass, which is performed when  $Z\_blk$  is greater than 1. The decoder uses significance information  $\sigma_n$  produced by decoding the HT cleanup pass, together with the HT SigProp bit-stream, to recover binary refinement values  $r_n \in \{0,1\}$  and refinement indicators  $z_n \in \{0,1\}$  for each sample in the HT code-block. Prior to performing the HT SigProp decoding procedure, the  $r_n$  and  $z_n$  values for all samples in the HT code-block are set to 0. The decoder then progressively updates these values, depending on the significance information from the HT cleanup pass, as well as the bits found within the HT SigProp bit-stream. During this process, additional sign values  $s_n$  are also decoded for samples where  $r_n = 1$ .
+
+HT SigProp decoding follows the same four-line stripe-oriented scanning pattern as the block decoder defined in REC. ITU-T T.800 | ISO/IEC 15444-1, which is illustrated in Figure 7. In this Specification, however, the location  $n$  that is used to identify individual samples conforms to the notation introduced in clause 7.2, corresponding to the quad-based scanning order. In following the stripe-oriented scan of Figure 7, the decoder shall skip any location that lies outside the HT code-block, which means that the last stripe in the block is truncated, if necessary, to  $Hblk - 4 \cdot \lfloor (Hblk - 1)/4 \rfloor$  lines.
+
+To facilitate the explanation, two neighbourhoods of the sample at location  $n$  are introduced: a propagation neighbourhood  $\mathcal{N}_n$ ; and a scan-causal neighbourhood  $\bar{\mathcal{N}}_n$ .
+
+If bit 3 of the SPcod or SPcoc field is 0 (see clause A.4), the propagation neighbourhood  $\mathcal{N}_n$  for a sample consists of all locations within the HT code-block that are immediate neighbours of the sample with location  $n$ ; for clarity, there are eight such neighbours, for all samples apart from those that lie on the boundaries of the HT code-block.
+
+If bit 3 of the SPcod or SPcoc field is 1 (see clause A.4), the propagation neighbourhood  $\mathcal{N}_n$  for a sample consists of all locations within the same stripe or a previous stripe, that are immediate neighbours of the sample with location  $n$ .
+
+NOTE 1 – Samples on the last line of a stripe have at most six propagation neighbours in this case, while samples on other lines within a stripe have at most eight propagation neighbours.
+
+The scan-causal neighbourhood  $\bar{\mathcal{N}}_n$  is the subset of  $\mathcal{N}_n$  corresponding to samples that appear earlier than the sample with location  $n$  in the stripe-oriented scan.
+
+NOTE 2 – As illustrated in Figure 7, the location of a sample in the stripe-oriented scan affects the number of samples that belong to its scan-causal neighbourhood.
+
+![Figure 7: Stripe-oriented scan illustrating scan-causal neighbourhoods. Part (a) shows a 4x4 grid where a 4-line stripe is being scanned. A neighborhood N_n (highlighted in green) covers a 3x3 area around sample n. Part (b) shows a 3-line stripe (height H=7 total) where neighborhood N_m is similarly highlighted. Arrows indicate the quad-based scanning order within columns and across column-groups.](043e64d41a3368d138ace3816fd26469_img.jpg)
+
+Figure 7: Stripe-oriented scan illustrating scan-causal neighbourhoods. Part (a) shows a 4x4 grid where a 4-line stripe is being scanned. A neighborhood N\_n (highlighted in green) covers a 3x3 area around sample n. Part (b) shows a 3-line stripe (height H=7 total) where neighborhood N\_m is similarly highlighted. Arrows indicate the quad-based scanning order within columns and across column-groups.
+
+**Figure 7 – Stripe-oriented scan illustrating scan-causal neighbourhoods  $\bar{\mathcal{N}}_n$  for a sample  $n$ , where sample indices are ordered according to the quad-based scanning convention of Figure 2.**
+
+**In the example, the HT code-block has height  $H=7$ , so the last stripe (b) in the stripe-oriented scan has only three lines, whereas stripe (a) has four**
+
+The HT SigProp decoding procedure involves a magnitude decoding step and a sign decoding step, that are interleaved on a quad-column basis. Following the stripe-oriented scan of Figure 7, the decoder performs the magnitude decoding step by invoking the `decodeSigPropMag` procedure in the following, for four stripe columns (a column-group), after which it passes through the same samples a second time, in the same order, performing the sign decoding step using the `decodeSigPropSign` procedure in the following. The process is repeated for all column-groups in a stripe, before proceeding with the next stripe. If the HT code-block width `Wblk` is not divisible by 4, the number of columns in the final column-group of each stripe is reduced to `mod(Wblk, 4)`.
+
+---
+
+Procedure: `decodeSigPropMag`  
+Input: sample location  $n$ , significance values  $\sigma$  and existing refinement values  $r$   
+Side effects: May change  $z_n$  and  $r_n$
+
+---
+
+```
+
+mbr = 0
+if ( $\sigma_n == 0$ )
+    for each  $m \in \mathcal{N}_n$ 
+        mbr = mbr |  $\sigma_m$ 
+    for each  $m \in \bar{\mathcal{N}}_n$ 
+        mbr = mbr |  $r_m$ 
+if (mbr != 0)
+    set  $z_n = 1$ 
+    set  $r_n = \text{importSigPropBit}$ 
+
+```
+
+---
+
+---
+
+```
+
+Procedure: decodeSigPropSign
+Input: sample location  $n$  and refinement value  $r_n$ 
+Side effects: May change sign value  $s_n$ 
+
+```
+
+---
+
+```
+
+if ( $r_n \neq 0$ )
+    set  $s_n = \text{importSigPropBit}$ 
+
+```
+
+---
+
+## 7.5 HT MagRef decoding procedure
+
+This clause describes the procedure for decoding an HT MagRef coding pass, which is performed when  $z\_blk$  is equal to 3. The decoder uses significance information  $\sigma_n$  produced by decoding the HT cleanup pass, together with the HT MagRef bit-stream, to recover binary refinement values  $r_n \in \{0,1\}$  and refinement indicators  $z_n \in \{0,1\}$  for each sample in the HT code-block. Prior to performing the HT MagRef decoding procedure,  $r_n$  and  $z_n$  for each sample have the values determined by the HT SigProp decoding procedure, which shall be performed first.
+
+HT MagRef decoding follows the same four-line stripe-oriented scanning pattern as the HT SigProp coding pass, as illustrated in Figure 7. Again, however, the location  $n$  that is used to identify individual samples here conforms to the notation introduced in clause 7.2, corresponding to the quad-based scanning order.
+
+The HT MagRef decoding procedure involves only a magnitude decoding step that is performed by applying the `decodeMagRefValue` procedure in the following to each sample, following the four-line stripe-oriented scan.
+
+---
+
+```
+
+Procedure: decodeMagRefValue
+Input: sample location  $n$  and significance value  $\sigma_n$ 
+Side effects: May change  $z_n$  and  $r_n$ 
+
+```
+
+---
+
+```
+
+if ( $\sigma_n \neq 0$ )
+    set  $z_n = 1$ 
+    set  $r_n = \text{importMagRefBit}$ 
+
+```
+
+---
+
+## 7.6 Sample output values
+
+This clause describes the process whereby a decoder converts decoded magnitude values  $\mu_n$ , sign values  $s_n$ , refinement values  $r_n$  and refinement indicators  $z_n$  into values for processing by the inverse quantization procedure defined in Annex E of Rec. ITU-T T.800 | ISO/IEC 15444-1, after the application of any applicable region of interest transformation, as described in Annex H of Rec. ITU-T T.800 | ISO/IEC 15444-1. Following the notation in Rec. ITU-T T.800 | ISO/IEC 15444-1, these values are the number of magnitude bits  $N_b(x, y)$ , the magnitude bits  $MSB_i(b, x, y)$  and the sign bits  $s_b(x, y)$ , where  $(x, y)$  identifies a location within sub-band  $b$ , and  $1 \leq i \leq N_i(x, y)$ .
+
+The procedure here depends upon the quantity  $S\_blk$  that identifies the number of skipped magnitude bit-planes associated with the HT cleanup coding pass, as described in Annex B. In what follows,  $b$  identifies the sub-band to which a decoded HT code-block belongs, and  $(x_n, y_n)$  denotes the sub-band-based coordinates of the sample with location  $n$  in this decoded HT code-block.
+
+The number of decoded magnitude bit-planes is found from
+
+$$N_b(x_n, y_n) = S\_blk + 1 + z_n$$
+
+while the sign bits are assigned as
+
+$$s_b(x_n, y_n) = s_n$$
+
+For each  $i$  in the range  $1 \leq i \leq S\_blk + 1$ , the magnitude bit  $MSB_i(b, x, y)$  is given by
+
+$$MSB_i(b, x_n, y_n) = \text{mod} \left( \left\lfloor \frac{\mu_n}{2^{S\_blk+1-i}} \right\rfloor, 2 \right)$$
+
+Finally, if  $z_n$  is non-zero,
+
+$$\text{MSB}_{S_{\text{blk}+2}}(b, x_n, y_n) = r_n$$
+
+# 8 Constrained codestream sets
+
+## 8.1 Overview
+
+Clause 8 defines sets of HTJ2K codestreams, each conforming to one or more specified constraints.
+
+These sets partition the space of all possible HTJ2K codestreams as a function of implementation throughput and complexity. They are provided to simplify the task of creating profiles and defining decoder capabilities.
+
+EXAMPLE – In order to reduce implementation complexity, a profile definition can specify that only HTJ2K codestreams that belong to the HTONLY set specified in clause 8.2 are permitted.
+
+## 8.2 HTONLY, HTDECLARED and MIXED sets
+
+The HTONLY set is the set of HTJ2K codestreams where all code-blocks are HT code-blocks.
+
+The HTDECLARED set is the set of HTJ2K codestreams where all code-blocks within a given tile-component are either a) HT code-blocks, or b) code-blocks as specified in Rec. ITU-T T.800 | ISO/IEC 15444-1.
+
+The MIXED set is the set of all HTJ2K codestreams that are not in the HTDECLARED set.
+
+NOTE 1 – A codestream that belongs to the HTONLY set also belongs to the HTDECLARED set, but the converse is not true. In particular, an HTJ2K codestream where all code-blocks conform to Rec. ITU-T T.800 | ISO/IEC 15444-1 belong to the HTDECLARED set, but not the HTONLY set.
+
+NOTE 2 – Decoding of HTJ2K codestreams that belong to the HTONLY set does not require decoding of code-blocks that conform to Rec. ITU-T T.800 | ISO/IEC 15444-1.
+
+## 8.3 SINGLEHT and MULTIHT sets
+
+The SINGLEHT set is the set of HTJ2K codestreams where at most one HT set is ever present for each HT code-block.
+
+The MULTIHT set is the set of all HTJ2K codestreams that are not in the SINGLEHT set.
+
+NOTE – Although a decoder is not required to decode more than one HT set for any HT code-block, parsing is more complex for codestreams in the MULTIHT set.
+
+EXAMPLE – The use of multiple non-empty HT sets in a code-block results in redundancy. This can be used, for instance, in content distribution systems to avoid the need for decoding and re-encoding code-blocks when transcoding to different coded data rates. The resulting transcoded codestream, however, normally contains at most one HT set per HT code-block.
+
+## 8.4 RGN and RGNFREE sets
+
+The RGNFREE set is the set of HTJ2K codestreams that do not contain any RGN marker segment.
+
+The RGN set is the set of all HTJ2K codestreams that are not in the RGNFREE set.
+
+NOTE 1 – Whether an HTJ2K codestream contains RGN marker segments impacts HT cleanup magnitude bounds as described in clause 8.7.3.
+
+NOTE 2 – RGN marker segments are typically used in the progressive communication of images that contain defined spatial regions of interest; however, the HT block-coder does not provide an effective mechanism for progressive coding.
+
+NOTE 3 – The presence of RGN marker segments complicates the dequantization procedure that is applied after block decoding.
+
+## 8.5 HOMOGENEOUS and HETEROGENEOUS sets
+
+The HOMOGENEOUS set is the set of HTJ2K codestreams where:
+
+- none of the functional marker segments, e.g., COD, COC, RGN, QCD, QCC, and POC, are present in any tile-part header; and
+- no PPT marker segment is present.
+
+The HETEROGENEOUS set is the set of all HTJ2K codestreams that are not in the HOMOGENEOUS set.
+
+NOTE – Decoder configuration information can be retrieved entirely from the main header if the HTJ2K codestream belongs to the HOMOGENEOUS set. Conversely, decoding codestreams that belong to the HETEROGENEOUS set can require a decoder to be reconfigured between tiles, which cannot be done until after its first tile-part is encountered.
+
+## 8.6 LOCAL and FRAG sets
+
+The LOCAL set is the set of HTJ2K codestreams where:
+
+- the exponents PPx and PPy satisfy  $PPx + PPy \leq 16$ , except in the lowest resolution level within each tile-component, where  $PPx + PPy \leq 14$ ; and
+- either (i) the codestream has only one quality layer, as identified via the SGcod parameter, or (ii) the progression order value for the SGcod, SPcoc, and Ppoc parameters is in the range 2 to 4 (see Table A.16 at Rec. ITU-T T.800 | ISO/IEC 15444-1).
+
+The FRAG set is the set of all HTJ2K codestreams that are not in the LOCAL set.
+
+NOTE 1 – The first condition in the foregoing limits the extent to which co-located code-blocks from sub-bands with different orientations can be separated within the codestream. The second condition prevents individual code-block byte-streams from being fragmented across non-consecutive packets within the codestream. Together, these conditions can reduce the amount of compressed data re-ordering needed when decoding a codestream.
+
+NOTE 2 – Fragmentation is typically used in combination with quality scalability; however, the HT block-coder does not provide an effective mechanism for progressive coding.
+
+## 8.7 Bounded magnitude sets
+
+### 8.7.1 Overview
+
+Clause 8.7 defines sets that correspond to bounds on the magnitudes  $\mu_n$  that are produced by the HT cleanup decoding procedure. The bounds depend upon whether an irreversible spatial wavelet transformation is employed, so there are two types of bounded magnitude sets: those in which an irreversible transform is associated with HT code-blocks; and those where only reversible transforms are associated with HT code-blocks.
+
+NOTE – Unlike the block-decoding algorithm specified in Rec. ITU-T T.800 | ISO/IEC 15444-1, the HT block-coding algorithm does not allow decoders to discard bits in order to accommodate limitations to their internal working precision. As a result, the magnitude bound affects implementation complexity. At the time of this writing, a reasonable magnitude bound for CPU-based implementations is  $B = 31$ , where the interpretation of  $B$  is found in clause 8.7.3.
+
+### 8.7.2 HTIRV and HTREV sets
+
+The high-throughput reversible (HTREV) set is the set of HTJ2K codestreams where every tile-component that contains one or more HT code-blocks signals a reversible transform.
+
+The high-throughput irreversible (HTIRV) set is the set of all HTJ2K codestreams that are not in the HTREV set.
+
+NOTE 1 – The use of reversible transforms impacts the MAGB<sub>P</sub> sets, as described in clause 8.7.3.
+
+NOTE 2 – In transcoding operations that reduce image resolution by discarding the  $k$  highest resolution levels from each tile-component, the magnitude bound  $B$  is increased by  $k$  for codestreams in the HTIRV set, while no such adjustment is made for codestreams in the HTREV set.
+
+### 8.7.3 MAGB<sub>P</sub> sets
+
+Each MAGB<sub>P</sub> set specified in Table 4 is associated with a value of the parameter  $B$ , and consists of the HTJ2K codestreams where all HT Cleanup magnitudes  $\mu_n$  of a given sub-band  $b$  are smaller than  $\mu_{bound}$ , where:
+
+$\mu_{bound} = 2^B$ , if  $B > 31$  or the sub-band's transformation type is not an irreversible transform; or
+
+$\mu_{bound} = 2^{\min\{31, B + [n_b] - 1\}}$  where  $n_b$  is the sub-band decomposition level, otherwise.
+
+NOTE 1 – If no RGN marker segment is present in the codestream, then all magnitudes  $\mu_n$  necessarily satisfy  $\mu_n < 2^{37}$ . If RGN marker segments are present in an HTJ2K codestream, then all magnitudes  $M$  necessarily satisfy  $\mu_n < 2^{74}$ .
+
+NOTE 2 – If the arbitrary decomposition extensions specified in Annex F of Rec. ITU-T T.801 | ISO/IEC 15444-2 is used, the sub-band decomposition level  $n_b$  can be an even or an odd integer multiple of  $\frac{1}{2}$ . The expression  $[n_b]$  ensures that  $\mu_{bound}$  is always an integer power of 2.
+
+EXAMPLE – A decoder can increase throughput by using a hardware-accelerated implementation if the HT cleanup magnitudes are below a given threshold, i.e., if the HTJ2K codestream belongs to a set where parameter  $B$  is below a certain threshold; and reverting to a slower software implementation otherwise.
+
+Table 4 – HT cleanup magnitudes bound codestream sets
+
+| Set MAGBP          | Parameter B |
+|--------------------|-------------|
+| MAGB <sub>0</sub>  | 8           |
+| MAGB <sub>1</sub>  | 9           |
+| MAGB <sub>2</sub>  | 10          |
+| MAGB <sub>3</sub>  | 11          |
+| MAGB <sub>4</sub>  | 12          |
+| MAGB <sub>5</sub>  | 13          |
+| MAGB <sub>6</sub>  | 14          |
+| MAGB <sub>7</sub>  | 15          |
+| MAGB <sub>8</sub>  | 16          |
+| MAGB <sub>9</sub>  | 17          |
+| MAGB <sub>10</sub> | 18          |
+| MAGB <sub>11</sub> | 19          |
+| MAGB <sub>12</sub> | 20          |
+| MAGB <sub>13</sub> | 21          |
+| MAGB <sub>14</sub> | 22          |
+| MAGB <sub>15</sub> | 23          |
+| MAGB <sub>16</sub> | 24          |
+| MAGB <sub>17</sub> | 25          |
+| MAGB <sub>18</sub> | 26          |
+| MAGB <sub>19</sub> | 27          |
+| MAGB <sub>20</sub> | 31          |
+| MAGB <sub>21</sub> | 35          |
+| MAGB <sub>22</sub> | 39          |
+| MAGB <sub>23</sub> | 43          |
+| MAGB <sub>24</sub> | 47          |
+| MAGB <sub>25</sub> | 51          |
+| MAGB <sub>26</sub> | 55          |
+| MAGB <sub>27</sub> | 59          |
+| MAGB <sub>28</sub> | 63          |
+| MAGB <sub>29</sub> | 67          |
+| MAGB <sub>30</sub> | 71          |
+| MAGB <sub>31</sub> | 74          |
+
+## 8.8 CPF<sub>N</sub> sets
+
+The set CPF<sub>N</sub> consists of all HTJ2K codestreams that can be obtained using the following procedure.
+
+- Let C1 be an Rec. ITU-T T.800 | ISO/IEC 15444-1 codestream conforming to profile *N*.
+- Let C2 be an HTJ2K codestream.
+- Block transcoding. Each code-block in C2 is either unchanged from C1 or transcoded to an HT code-block by decoding and then re-encoding such that it conforms to Annex B. The final HT cleanup pass of each transcoded code-block corresponds to the final cleanup pass from the original code-block in C1, except where this cleanup pass involve sample magnitudes  $\mu_n$  that are inconsistent with constraints imposed on C2, in which case the smallest number of original coding passes necessary to avoid such inconsistency are discarded. If, after any such discarding, the original code-block in C1 has a SigProp pass that follows the final cleanup pass, the transcoded code-block in C2 has a corresponding HT SigProp pass. Similarly, if the original code-block in C1 has a MagRef pass that follows the final non-discarded cleanup pass, the transcoded code-block in C2 has a corresponding HT MagRef pass.
+
+NOTE 1 – Constraints on C2 are signalled using the CAP marker segment, as specified in clause A.3, and the PRF marker segment, as specified in Rec. ITU-T T.800 | ISO/IEC 15444-1.
+
+- Packetization. For each packet of C1, there shall be a corresponding packet of C2 and vice-versa. The code-block-coding passes within each packet in C2 shall be identical to the coding passes included within each packet in C1, with the exception only of those coding passes from C1 that are discarded as specified in the foregoing.
+- Marker segment generation. All functional, fixed information and pointer marker segments from C1 are preserved in C2, except that the values of the SPcod/SPcoc parameter in COD/COC marker segments are modified to reflect the use of HT block coding, the SIZ, CAP and PRF marker segments are modified or introduced according to the requirements of Annex A, and SOT, PLT, PLM and TLM marker segments are updated to reflect the lengths of the transcoded code-blocks. No new marker segments are introduced into C2 that were not present in C1, apart from the CAP marker segment, and, optionally, a PRF marker segment.
+- Codestream ordering. For each tile-part header of C1, there is a corresponding tile-part header in C2, and vice-versa, and all tile-part headers and packets for C2 appear in the same order as the corresponding tile-part headers and packets in C1.
+
+NOTE 2 – There is no one-to-one mapping between the set  $CPF_N$  and the set of Rec. ITU-T T.800 | ISO/IEC 15444-1 codestreams with profile number  $N$  since the termination of codeword segments is not uniquely defined in either this Specification, or in Rec. ITU-T T.800 | ISO/IEC 15444-1.
+
+# 9 Media types
+
+Annex E specifies media types as defined in IETF RFC 6838.
+
+# Annex A
+
+## HTJ2K codestream syntax
+
+(This annex forms an integral part of this Recommendation | International Standard.)
+
+## A.1 General
+
+This annex specifies the extensions and constraints to the codestream syntax specified in Rec. ITU-T T.800 | ISO/IEC 15444-1 necessary to support HT code-blocks.
+
+Table A.1 lists the marker segments affected by this Specification.
+
+**Table A.1 – Marker segments affected by this Specification (informative)**
+
+|                                                                                |               |
+|--------------------------------------------------------------------------------|---------------|
+| Extensions to marker segments specified in Rec. ITU-T T.800   ISO/IEC 15444-1  | CAP, COD, COC |
+| Constraints to marker segments specified in Rec. ITU-T T.800   ISO/IEC 15444-1 | SIZ, RGN      |
+| Marker segments specified in this Recommendation   International Standard      | CPF           |
+
+Unless specified otherwise in clauses A.2 to A.6, an HTJ2K codestream syntax shall conform to Annex A of Rec. ITU-T T.800 | ISO/IEC 15444-1, together with any other signalled capability.
+
+In the tables of this annex, the symbol "r" denotes bits that are reserved, and the symbol "x" denotes bits whose value can be either 0 or 1.
+
+For HTJ2K codestreams conforming to this Specification, the value of each bit denoted with an "r" shall be 0.
+
+NOTE – The behaviour of implementations that conform to this Specification is left unspecified when processing an HTJ2K codestream where the value of any bit denoted with an "r" is not 0.
+
+### A.2 SIZ marker segment
+
+Bit 14 of Rsiz shall be equal to 1.
+
+### A.3 CAP marker segment
+
+#### A.3.1 General
+
+The CAP marker segment shall be present.
+
+The value of Pcap<sup>15</sup> shall be equal to 1.
+
+NOTE 1 – Pcap<sup>15</sup> is the 15<sup>th</sup> most significant bit of the Pcap field.
+
+Table A.2 defines values for the Ccap<sup>15</sup> field.
+
+NOTE 2 – The Ccap<sup>15</sup> field contains information that allows a decoder to fast-fail gracefully, optimize its throughput, or generally simplify its operations, without requiring the codestream to be processed in its entirety.
+
+Table A.2 – Ccap<sup>15</sup> syntax and semantics
+
+| Values (bits) |      |      |      | Capability                                                                                                                                                              |
+|---------------|------|------|------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| MSB           |      | LSB  |      |                                                                                                                                                                         |
+| 00xx          | xxxx | xxxx | xxxx | All code-blocks are HT code-blocks.                                                                                                                                     |
+| 10xx          | xxxx | xxxx | xxxx | Each tile-component either consists entirely of HT code-blocks, or consists entirely of code-blocks conforming to Rec. ITU-T T.800   ISO/IEC 15444-1.                   |
+| 11xx          | xxxx | xxxx | xxxx | Code-blocks within a tile-component can either be HT code-blocks, or conform to Rec. ITU-T T.800   ISO/IEC 15444-1.                                                     |
+| 01xx          | xxxx | xxxx | xxxx | Reserved for future use by ITU-T   ISO/IEC                                                                                                                              |
+| xx0x          | xxxx | xxxx | xxxx | Zero or one HT set is present for any HT code-block.                                                                                                                    |
+| xx1x          | xxxx | xxxx | xxxx | More than one HT sets can be present for an HT code-block, indicating that the codestream, when decoded, can result in different quality reconstructions (see Annex B). |
+| xxx0          | xxxx | xxxx | xxxx | No region-of-interest marker present                                                                                                                                    |
+| xxx1          | xxxx | xxxx | xxxx | Region-of-interest marker can be present                                                                                                                                |
+| xxxx          | 0xxx | xxxx | xxxx | Homogeneous codestream                                                                                                                                                  |
+| xxxx          | 1xxx | xxxx | xxxx | Heterogeneous codestream                                                                                                                                                |
+| xxxx          | xxxx | xx0x | xxxx | HT code-blocks only used with reversible transforms                                                                                                                     |
+| xxxx          | xxxx | xx1x | xxxx | HT code-blocks can be used with irreversible transforms                                                                                                                 |
+| xxxx          | xxxx | xxxp | pppp | Bits $p^i$ specify the HT cleanup magnitude bound                                                                                                                       |
+| xxxx          | xrrr | rrxx | xxxx | Reserved for future use by ITU-T   ISO/IEC                                                                                                                              |
+
+#### A.3.2 Bits 14-15 of Ccap<sup>15</sup>
+
+If Bits 14 and 15 of Ccap<sup>15</sup> are 0, then:
+
+- the codestream shall belong to the HTONLY set specified in clause 8.2; and
+- bits 6 and 7 of all SPcod or SPcoc values are equal to 0.
+
+If bit 14 of Ccap<sup>15</sup> is 0 and bit 15 of Ccap<sup>15</sup> is 1, then:
+
+- the codestream shall belong to the HTDECLARED set specified in clause 8.2; and
+- bit 7 of all SPcod or SPcoc values is equal to 0.
+
+If bit 14 of Ccap<sup>15</sup> is 1 and bit 15 of Ccap<sup>15</sup> is 1, then the codestream may belong to the MIXED set specified in clause 8.2.
+
+NOTE – A codestream that belongs to the HTONLY set can still contain SPcod or SPcoc values where both bits 6 and 7 are equal to 1.
+
+#### A.3.3 Bit 13 of Ccap<sup>15</sup>
+
+If bit 13 of Ccap<sup>15</sup> is 0, then the codestream shall belong to the SINGLEHT set specified in clause 8.3.
+
+If bit 13 of Ccap<sup>15</sup> is 1, then the codestream may belong to the MULTIHT set specified in clause 8.3.
+
+#### A.3.4 Bit 12 of Ccap<sup>15</sup>
+
+If bit 12 of Ccap<sup>15</sup> is 0, then the codestream shall belong to the RGNFREE set specified in clause 8.4.
+
+If bit 12 of Ccap<sup>15</sup> is 1, then the codestream may belong to the RGN set specified in clause 8.4.
+
+#### A.3.5 Bit 11 of Ccap<sup>15</sup>
+
+If bit 11 of Ccap<sup>15</sup> is 0, then the codestream shall belong to the HOMOGENEOUS set specified in clause 8.5.
+
+If bit 11 of Ccap<sup>15</sup> is 1, then the codestream may belong to the HETEROGENEOUS set specified in clause 8.5.
+
+#### A.3.6 Bit 5 of Ccap<sup>15</sup>
+
+If bit 5 of Ccap<sup>15</sup> is 0, then:
+
+- the codestream shall belong to the HTREV set specified in clause 8.6; and
+- tile-components for which an irreversible transform is signalled shall have bit 6 of the SPcod or SPcoc value equal to 0.
+
+If bit 5 of  $Ccap^{15}$  is 1, then the codestream may belong to the HTIRV set specified in clause 8.6.
+
+#### A.3.7 Bits 0-4 of $Ccap^{15}$
+
+The codestream shall belong to the  $MAGB_P$  set specified in clause 8.7.3, with the parameter B equal to:
+
+$$B = \begin{cases} 8, & P = 0 \\ P + 8, & P < 20 \\ 4(P - 19) + 27, & 20 \leq P < 31 \\ 74, & P = 31 \end{cases}$$
+
+where
+
+$$P = \sum_{i=0}^4 Ccap_i^{15} \cdot 2^i, \text{ and}$$
+
+$Ccap_i^{15}$  is bit  $i$  of  $Ccap^{15}$  with  $i = 0$  corresponding to the LSB.
+
+NOTE – Upper bounds on the HT cleanup magnitudes  $\mu_n$  can also be determined from quantization parameters found in QCD and QCC marker segments, possibly modified by the presence of RGN marker segments. These bounds can be smaller than the bound signalled by bits 0-4 of  $Ccap^{15}$ .
+
+### A.4 COD and COC marker segments
+
+The COD and COC marker segments defined in Rec. ITU-T T.800 | ISO/IEC 15444-1 are modified as follows.
+
+For a given SPcod or SPcoc value, if bit 6 is equal to 0:
+
+- no code-blocks within the corresponding tile-component shall be HT code-blocks; and
+- the semantics of the SPcod or SPcoc value are as defined in Table A.19 at Rec. ITU-T T.800 | ISO/IEC 15444-1.
+
+**Table A.3 – SPcod and SPcoc parameters semantics when bits 6 and 7 are 1 and 0, respectively**
+
+| Value (bits) |      | Code-block style             |
+|--------------|------|------------------------------|
+| MSB          | LSB  |                              |
+| 01rr         | 0rrr | No vertically causal context |
+| 01rr         | 1rrr | Vertically causal context    |
+
+For a given SPcod or SPcoc value, if bit 6 is equal to 1 and bit 7 is equal to 0:
+
+- all code-blocks within the corresponding tile-component shall be HT code-blocks as defined in Annex B; and
+- the semantics of the SPcod or SPcoc value shall be as defined in Table A.3.
+
+**Table A.4 – SPcod and SPcoc parameters semantics when bits 6 and 7 are 1**
+
+| Value (bits) |      | Code-block style                                                                                     |
+|--------------|------|------------------------------------------------------------------------------------------------------|
+| MSB          | LSB  |                                                                                                      |
+| 11xx         | xr0r | No reset of context probabilities on coding pass boundaries (does not apply to HT code-blocks)       |
+| 11xx         | xr1r | Reset context probabilities on coding pass boundaries (does not apply to HT code-blocks)             |
+| 11xx         | 0rxx | No vertically causal context (applies to both Rec. ITU-T T.800   ISO/IEC 15444-1 and HT code-blocks) |
+| 11xx         | 1rxx | Vertically causal context (applies to both Rec. ITU-T T.800   ISO/IEC 15444-1 and HT code-blocks)    |
+| 11x0         | xrrr | No predictable termination (does not apply to HT code-blocks)                                        |
+| 11x1         | xrrr | Predictable termination (does not apply to HT code-blocks)                                           |
+| 110x         | xrrr | No segmentation symbols are used (does not apply to HT code-blocks)                                  |
+| 111x         | xrrr | Segmentation symbols are used (does not apply to HT code-blocks)                                     |
+
+For a given SPcod or SPcoc value, if bit 6 is equal to 1 and bit 7 is equal to 1:
+
+- zero or more of the code-blocks within the corresponding tile-component shall be HT code-blocks as defined in Annex B, and the remaining code-blocks shall conform to Rec. ITU-T T.800 | ISO/IEC 15444-1;
+
+- if a code-block is an HT code-block, and given its first non-zero length codeword segment:
+  - the first bit of that codeword segment length, as defined in clause B.10.7.1 of ITU-T T.800 | ISO/IEC 15444-1, shall be 0; and
+  - *Lblock*, as defined in clause B.10.7.1 of ITU-T T.800 | ISO/IEC 15444-1, shall be greater than 3.
+- Rec. ITU-T T.800 | ISO/IEC 15444-1 code-blocks shall use neither selective arithmetic coding bypass nor termination on each coding pass; and
+- the semantics of the SPcod or SPcoc value shall be as defined in Table A.4.
+
+NOTE – An HT code-block can be differentiated from a Rec. ITU-T T.800 | ISO/IEC 15444-1 code-block by processing the code-block assuming it conforms to Annex B. Failure of such processing indicates that the code-block might conform to Rec. ITU-T T.800 | ISO/IEC 15444-1.
+
+### A.5 RGN marker segment
+
+If the RGN marker segment is present, the value of the SPRgn parameter shall be less than or equal to 37.
+
+## A.6 CPF marker segment
+
+**Function:** The corresponding profile (CPF) marker segment is provided to facilitate the reversible transcoding of HTJ2K codestreams to and from codestreams that conform to Rec. ITU-T T.800 | ISO/IEC 15444-1.
+
+Zero or one CPF marker segment shall be present in an HTJ2K codestream.
+
+If the CPF marker segment is present, the HTJ2K codestream shall be in the set  $CPF_X$ , as specified in clause 8.8, with  $X$  equal to the CPFnum parameter of the CPF marker segment.
+
+NOTE – An HTJ2K codestream that contains a CPF marker segment is subject to the constraints specified in the Ccap<sup>15</sup> field of the CAP marker segment, and by any profile signalled in the PRF marker segment.
+
+CPFnum shall be equal to the value found in bits 0 to 11 of Rsiz of the corresponding codestream, unless that value is 4095, in which case CPFnum shall be equal to the PRFnum value found in the PRF marker segment of the corresponding codestream.
+
+CPFnum is computed from the  $Pcpf^i$  integers as follows:
+
+$$CPFnum = -1 + \sum_{i=1}^N Pcpf^i \cdot 2^{16 \cdot (i-1)}$$
+
+**Usage:** Optional. If present, the CPF marker segment shall appear after the SIZ marker segment, CAP marker segment and, if present, the PRF marker segment, but before any other marker segments defined in Rec. ITU-T T.800 | ISO/IEC 15444-1.
+
+**Length:** Variable. See Figure A.1.
+
+![Figure A.1: Corresponding profiles syntax. A diagram showing the structure of the CPF marker segment. It consists of four boxes: 'CPF', 'Lcpf', 'Pcpf^1', and 'Pcpf^N'. The 'Pcpf^1' and 'Pcpf^N' boxes are separated by a shaded gray area. Below the diagram is the label 'T.814(19)_FA.1'.](44c70af075e4d9bbc6fbe267a666b3b0_img.jpg)
+
+Figure A.1: Corresponding profiles syntax. A diagram showing the structure of the CPF marker segment. It consists of four boxes: 'CPF', 'Lcpf', 'Pcpf^1', and 'Pcpf^N'. The 'Pcpf^1' and 'Pcpf^N' boxes are separated by a shaded gray area. Below the diagram is the label 'T.814(19)\_FA.1'.
+
+**Figure A.1 – Corresponding profiles syntax**
+
+**CPF** Marker Code.
+
+**Lcpf** Length in bytes of the CPF marker segment (not including the marker). *Lcpf* is given by the following formula:
+
+$$Lcpf = 2 + 2N$$
+
+where  $N$ , the number of  $Pcpf^i$  values used to express  $CPFnum$ , is given by:
+
+$$N = \left\lceil \frac{\log_2(1 + CPFnum)}{16} \right\rceil + 1$$
+
+**Pcpf<sup>i</sup>**  $Pcpf^i$  are 16-bit integers that encode  $CPFnum$ .  $Pcpf^N$  shall not be zero.
+
+**Table A.5 – Corresponding profile parameter values**
+
+| Parameter         | Size (bits) | Value         |
+|-------------------|-------------|---------------|
+| CPF               | 16          | 0xFF59        |
+| Lcpf              | 16          | 4-65534       |
+| Pcpf <sup>i</sup> | 16          | 0x0000-0xFFFF |
+
+# Annex B
+
+## HT data organization
+
+(This annex forms an integral part of this Recommendation | International Standard.)
+
+## B.1 HT sets
+
+As illustrated in Figure B.1, an HT code-block consists of:
+
+- $3 \cdot P_0$  coding passes, called placeholder passes, for which no codeword segment bytes appear in the codestream;
+- followed by groups of coding passes, called HT sets, each of which consists of three coding passes, except for the last HT set, which consists of 1, 2 or 3 coding passes.
+
+NOTE – In many cases, the first coding pass contribution from a code-block to any packet will include an HT cleanup pass and have non-zero length. However, placeholder passes can be used to preserve quality layer boundaries from a codestream that was encoded using the block-coding algorithm from Rec. ITU-T T.800 | ISO/IEC 15444-1 and was subsequently transcoded. Similarly, placeholder passes can be used to provide suggested quality layer boundaries to use when transcoding the HT block-coding algorithm representation to one that uses the block-coding algorithm from Rec. ITU-T T.800 | ISO/IEC 15444-1.
+
+The coding passes within an HT set are defined as follows:
+
+- The first coding pass is an HT cleanup coding pass;
+- If present, the second coding pass is an HT SigProp coding pass;
+- If present, the third coding pass is an MagRef coding pass.
+
+![Figure B.1: HT code-block structure diagram. The diagram shows a sequence of coding passes represented by vertical lines. Solid vertical lines indicate HT set boundaries, while dotted vertical lines indicate coding pass boundaries. The structure is divided into segments: (a) HT cleanup segments, (b) HT refinement segments, (c) placeholder passes, and (d) HT sets. The first HT set (d) contains three passes: C (Cleanup), U (SigProp), and P (MagRef). Subsequent HT sets (d) contain two passes: C (Cleanup) and S (SigProp). The diagram ends with an ellipsis and a final HT set (d) containing two passes: C (Cleanup) and S (SigProp).](257c8341b41f1f4a287f27d33227974c_img.jpg)
+
+T.814(19)\_FB.1
+
+Figure B.1: HT code-block structure diagram. The diagram shows a sequence of coding passes represented by vertical lines. Solid vertical lines indicate HT set boundaries, while dotted vertical lines indicate coding pass boundaries. The structure is divided into segments: (a) HT cleanup segments, (b) HT refinement segments, (c) placeholder passes, and (d) HT sets. The first HT set (d) contains three passes: C (Cleanup), U (SigProp), and P (MagRef). Subsequent HT sets (d) contain two passes: C (Cleanup) and S (SigProp). The diagram ends with an ellipsis and a final HT set (d) containing two passes: C (Cleanup) and S (SigProp).
+
+**Figure B.1 – HT code-block structure. The solid vertical lines indicate HT set boundaries. The dotted lines indicate coding pass boundaries. (a) are HT cleanup segments, (b) are HT refinement segments, (c) are placeholder passes and (d) are HT sets.**
+
+### B.2 HT segments
+
+As illustrated in Figure B.1, coding passes are arranged in HT segments based on a set  $T$  of coding pass indices.
+
+Each index in the set  $T$  defines one HT segment and corresponds to the last coding pass of the HT segment.
+
+$$T = \bigcup_{k \in \mathbb{N}} (3P_0 + T_k), \text{ where } T_k = \left\lceil \frac{3k}{2} \right\rceil$$
+
+An HT cleanup segment is an HT segment that contains an HT cleanup coding pass.
+
+An HT refinement segment is an HT segment that contains an HT SigProp coding pass.
+
+## B.3 Packets, Z\_blk and S\_blk
+
+The packet, as defined in Rec. ITU-T T.800 | ISO/IEC 15444-1, that contains the first HT cleanup coding pass for a code-block shall include only one HT cleanup coding pass.
+
+NOTE 1 – This packet can contain at most two additional coding passes: HT SigProp coding pass and HT MagRef coding pass.
+
+Each codeword segment for a given code-block in a packet terminates with either:
+
+- a coding pass of the code-block with an index in set  $T$  defined in clause B.2; or
+
+- the last coding pass of the code-block included in the packet.
+
+The bytes of an HT segment are obtained by concatenating the bytes of its constituent codeword segments, and the length of an HT segment is the sum of the lengths of those codeword segments.
+
+Except for the first HT cleanup segment of a code-block, the length of an HT cleanup segment shall be either 0 or greater than 1.
+
+The length of the first HT cleanup segment of a code-block shall be greater than 1.
+
+If the length of an HT cleanup segment within an HT set is 0, then the length of any HT refinement segment in the same HT set shall be 0.
+
+NOTE 2 – HT sets that contain only zero-length HT segments can be used to skip bit-planes between non-empty HT sets.
+
+Given an HT set,  $z\_blk$  is defined as follows:
+
+- $z\_blk = 0$ , if the length of the HT cleanup segment is 0;
+- $z\_blk = 1$ , if the HT cleanup segment is the only segment of the HT set whose length is not 0;
+- $z\_blk$  is the number of coding passes in the HT set, otherwise.
+
+NOTE 3 – As detailed in clause 7.1.1,  $z\_blk$  is the number of coding passes processed by the decoder. The condition where  $z\_blk$  is equal to 1 allows multiple HT cleanup coding passes to be included for a code-block, without including any SigProp or MagRef code bytes, while avoiding any concern that the empty coding passes might be decoded, impacting reconstructed image quality.
+
+Given an HT set, the number of skipped magnitude bit-planes  $s\_blk$  is defined as follows:
+
+$$s\_blk = P + P_0 + s\_skip$$
+
+where  $P$  is the number of zero-bit-planes recovered from the packet that contains the first contribution for the code-block, and  $s\_skip$  is the number of HT sets preceding the given HT set.
+
+NOTE 4 – The first contribution for the code-block can consist only of placeholder passes.
+
+# Annex C
+
+## CxtVLC tables
+
+(This annex forms an integral part of this Recommendation | International Standard.)
+
+Annex C specifies the CxtVLC\_table\_0 and CxtVLC\_table\_1 coding tables that are used by the decodeCxtVLC procedure.
+
+The values of a coding table are specified using the bracket notation  $\{ \{ \dots \}, \{ \dots \} \}$ , where inner pair of brackets are separated by commas and each inner pair of brackets specifies the values of the fields of an entry. The values of the fields are separated by commas and appear in the following order:  $c_q, \rho_q, u_q^{\text{off}}, \bar{e}_q^K, \bar{e}_q^1, w, l_w$ .
+
+Hexadecimal notation is indicated by prefixing the hexadecimal number by "0x". For example, 0x41 represents an eight-bit string having only its second and its last bits (counted from the most to the LSB) equal to 1.
+
+Numerical values not enclosed in single quotes and not prefixed by "0x" are decimal values.
+
+The field  $w$  represents the codeword as a little-endian integer, meaning that the LSB of the integer  $w$  appears first in the VLC bit-stream, followed by the second LSB and so forth, for a total number of bits indicated by field  $l_w$ .
+
+CxtVLC\_table\_0 is specified as follows:
+
+---
+
+```
+
+CxtVLC_table_0 = { {0, 0x1, 0x0, 0x0, 0x0, 0x06, 4},
+{0, 0x1, 0x1, 0x1, 0x1, 0x3F, 7},
+{0, 0x2, 0x0, 0x0, 0x0, 0x00, 3},
+{0, 0x2, 0x1, 0x2, 0x2, 0x7F, 7},
+{0, 0x3, 0x0, 0x0, 0x0, 0x11, 5},
+{0, 0x3, 0x1, 0x2, 0x2, 0x5F, 7},
+{0, 0x3, 0x1, 0x3, 0x1, 0x1F, 7},
+{0, 0x4, 0x0, 0x0, 0x0, 0x02, 3},
+{0, 0x4, 0x1, 0x4, 0x4, 0x13, 6},
+{0, 0x5, 0x0, 0x0, 0x0, 0x0E, 5},
+{0, 0x5, 0x1, 0x4, 0x4, 0x23, 6},
+{0, 0x5, 0x1, 0x5, 0x1, 0x0F, 7},
+{0, 0x6, 0x0, 0x0, 0x0, 0x03, 6},
+{0, 0x6, 0x1, 0x0, 0x0, 0x6F, 7},
+{0, 0x7, 0x0, 0x0, 0x0, 0x2F, 7},
+{0, 0x7, 0x1, 0x2, 0x2, 0x4F, 7},
+{0, 0x7, 0x1, 0x2, 0x0, 0x0D, 6},
+{0, 0x8, 0x0, 0x0, 0x0, 0x04, 3},
+{0, 0x8, 0x1, 0x8, 0x8, 0x3D, 6},
+{0, 0x9, 0x0, 0x0, 0x0, 0x1D, 6},
+{0, 0x9, 0x1, 0x0, 0x0, 0x2D, 6},
+{0, 0xA, 0x0, 0x0, 0x0, 0x01, 5},
+{0, 0xA, 0x1, 0x8, 0x8, 0x35, 6},
+{0, 0xA, 0x1, 0xA, 0x2, 0x77, 7},
+{0, 0xB, 0x0, 0x0, 0x0, 0x37, 7},
+{0, 0xB, 0x1, 0x1, 0x1, 0x57, 7},
+{0, 0xB, 0x1, 0x1, 0x0, 0x09, 6},
+{0, 0xC, 0x0, 0x0, 0x0, 0x1E, 5},
+
+```
+
+---
+
+---
+
+```
+
+{0, 0xC, 0x1, 0xC, 0xC, 0x17, 7},
+{0, 0xC, 0x1, 0xC, 0x4, 0x15, 6},
+{0, 0xC, 0x1, 0xC, 0x8, 0x25, 6},
+{0, 0xD, 0x0, 0x0, 0x0, 0x67, 7},
+{0, 0xD, 0x1, 0x1, 0x1, 0x27, 7},
+{0, 0xD, 0x1, 0x5, 0x4, 0x47, 7},
+{0, 0xD, 0x1, 0xD, 0x8, 0x07, 7},
+{0, 0xE, 0x0, 0x0, 0x0, 0x7B, 7},
+{0, 0xE, 0x1, 0x2, 0x2, 0x4B, 7},
+{0, 0xE, 0x1, 0xA, 0x8, 0x05, 6},
+{0, 0xE, 0x1, 0xE, 0x4, 0x3B, 7},
+{0, 0xF, 0x0, 0x0, 0x0, 0x5B, 7},
+{0, 0xF, 0x1, 0x9, 0x9, 0x1B, 7},
+{0, 0xF, 0x1, 0xB, 0xA, 0x6B, 7},
+{0, 0xF, 0x1, 0xF, 0xC, 0x2B, 7},
+{0, 0xF, 0x1, 0xF, 0x8, 0x39, 6},
+{0, 0xF, 0x1, 0xE, 0x6, 0x73, 7},
+{0, 0xF, 0x1, 0xE, 0x2, 0x19, 6},
+{0, 0xF, 0x1, 0xF, 0x5, 0x0B, 7},
+{0, 0xF, 0x1, 0xF, 0x4, 0x29, 6},
+{0, 0xF, 0x1, 0xF, 0x1, 0x33, 7},
+{1, 0x0, 0x0, 0x0, 0x0, 0x00, 2},
+{1, 0x1, 0x0, 0x0, 0x0, 0x0E, 4},
+{1, 0x1, 0x1, 0x1, 0x1, 0x1F, 7},
+{1, 0x2, 0x0, 0x0, 0x0, 0x06, 4},
+{1, 0x2, 0x1, 0x2, 0x2, 0x3B, 6},
+{1, 0x3, 0x0, 0x0, 0x0, 0x1B, 6},
+{1, 0x3, 0x1, 0x0, 0x0, 0x3D, 6},
+{1, 0x4, 0x0, 0x0, 0x0, 0x0A, 4},
+{1, 0x4, 0x1, 0x4, 0x4, 0x2B, 6},
+{1, 0x5, 0x0, 0x0, 0x0, 0x0B, 6},
+{1, 0x5, 0x1, 0x4, 0x4, 0x33, 6},
+{1, 0x5, 0x1, 0x5, 0x1, 0x7F, 7},
+{1, 0x6, 0x0, 0x0, 0x0, 0x13, 6},
+{1, 0x6, 0x1, 0x0, 0x0, 0x23, 6},
+{1, 0x7, 0x0, 0x0, 0x0, 0x3F, 7},
+{1, 0x7, 0x1, 0x2, 0x2, 0x5F, 7},
+{1, 0x7, 0x1, 0x2, 0x0, 0x03, 6},
+{1, 0x8, 0x0, 0x0, 0x0, 0x02, 4},
+{1, 0x8, 0x1, 0x8, 0x8, 0x1D, 6},
+{1, 0x9, 0x0, 0x0, 0x0, 0x2D, 6},
+{1, 0x9, 0x1, 0x0, 0x0, 0x0D, 6},
+
+```
+
+---
+
+---
+
+```
+
+{1, 0xA, 0x0, 0x0, 0x0, 0x35, 6},
+{1, 0xA, 0x1, 0x8, 0x8, 0x15, 6},
+{1, 0xA, 0x1, 0xA, 0x2, 0x6F, 7},
+{1, 0xB, 0x0, 0x0, 0x0, 0x2F, 7},
+{1, 0xB, 0x1, 0x1, 0x1, 0x4F, 7},
+{1, 0xB, 0x1, 0x1, 0x0, 0x11, 6},
+{1, 0xC, 0x0, 0x0, 0x0, 0x01, 5},
+{1, 0xC, 0x1, 0x8, 0x8, 0x25, 6},
+{1, 0xC, 0x1, 0xC, 0x4, 0x05, 6},
+{1, 0xD, 0x0, 0x0, 0x0, 0x0F, 7},
+{1, 0xD, 0x1, 0x1, 0x1, 0x17, 7},
+{1, 0xD, 0x1, 0x5, 0x4, 0x39, 6},
+{1, 0xD, 0x1, 0xD, 0x8, 0x77, 7},
+{1, 0xE, 0x0, 0x0, 0x0, 0x37, 7},
+{1, 0xE, 0x1, 0x2, 0x2, 0x57, 7},
+{1, 0xE, 0x1, 0xA, 0x8, 0x19, 6},
+{1, 0xE, 0x1, 0xE, 0x4, 0x67, 7},
+{1, 0xF, 0x0, 0x0, 0x0, 0x07, 7},
+{1, 0xF, 0x1, 0xB, 0x8, 0x29, 6},
+{1, 0xF, 0x1, 0x8, 0x8, 0x27, 7},
+{1, 0xF, 0x1, 0xA, 0x2, 0x09, 6},
+{1, 0xF, 0x1, 0xE, 0x4, 0x31, 6},
+{1, 0xF, 0x1, 0xF, 0x1, 0x47, 7},
+{2, 0x0, 0x0, 0x0, 0x0, 0x00, 2},
+{2, 0x1, 0x0, 0x0, 0x0, 0x0E, 4},
+{2, 0x1, 0x1, 0x1, 0x1, 0x1B, 6},
+{2, 0x2, 0x0, 0x0, 0x0, 0x06, 4},
+{2, 0x2, 0x1, 0x2, 0x2, 0x3F, 7},
+{2, 0x3, 0x0, 0x0, 0x0, 0x2B, 6},
+{2, 0x3, 0x1, 0x1, 0x1, 0x33, 6},
+{2, 0x3, 0x1, 0x3, 0x2, 0x7F, 7},
+{2, 0x4, 0x0, 0x0, 0x0, 0x0A, 4},
+{2, 0x4, 0x1, 0x4, 0x4, 0x0B, 6},
+{2, 0x5, 0x0, 0x0, 0x0, 0x01, 5},
+{2, 0x5, 0x1, 0x5, 0x5, 0x2F, 7},
+{2, 0x5, 0x1, 0x5, 0x1, 0x13, 6},
+{2, 0x5, 0x1, 0x5, 0x4, 0x23, 6},
+{2, 0x6, 0x0, 0x0, 0x0, 0x03, 6},
+{2, 0x6, 0x1, 0x0, 0x0, 0x5F, 7},
+{2, 0x7, 0x0, 0x0, 0x0, 0x1F, 7},
+{2, 0x7, 0x1, 0x2, 0x2, 0x6F, 7},
+{2, 0x7, 0x1, 0x3, 0x1, 0x11, 6},
+
+```
+
+---
+
+---
+
+```
+
+{2, 0x7, 0x1, 0x7, 0x4, 0x37, 7},
+{2, 0x8, 0x0, 0x0, 0x0, 0x02, 4},
+{2, 0x8, 0x1, 0x8, 0x8, 0x4F, 7},
+{2, 0x9, 0x0, 0x0, 0x0, 0x3D, 6},
+{2, 0x9, 0x1, 0x0, 0x0, 0x1D, 6},
+{2, 0xA, 0x0, 0x0, 0x0, 0x2D, 6},
+{2, 0xA, 0x1, 0x0, 0x0, 0x0D, 6},
+{2, 0xB, 0x0, 0x0, 0x0, 0x0F, 7},
+{2, 0xB, 0x1, 0x2, 0x2, 0x77, 7},
+{2, 0xB, 0x1, 0x2, 0x0, 0x35, 6},
+{2, 0xC, 0x0, 0x0, 0x0, 0x15, 6},
+{2, 0xC, 0x1, 0x4, 0x4, 0x25, 6},
+{2, 0xC, 0x1, 0xC, 0x8, 0x57, 7},
+{2, 0xD, 0x0, 0x0, 0x0, 0x17, 7},
+{2, 0xD, 0x1, 0x8, 0x8, 0x05, 6},
+{2, 0xD, 0x1, 0xC, 0x4, 0x39, 6},
+{2, 0xD, 0x1, 0xD, 0x1, 0x67, 7},
+{2, 0xE, 0x0, 0x0, 0x0, 0x27, 7},
+{2, 0xE, 0x1, 0x2, 0x2, 0x7B, 7},
+{2, 0xE, 0x1, 0x2, 0x0, 0x19, 6},
+{2, 0xF, 0x0, 0x0, 0x0, 0x47, 7},
+{2, 0xF, 0x1, 0xF, 0x1, 0x29, 6},
+{2, 0xF, 0x1, 0x1, 0x1, 0x09, 6},
+{2, 0xF, 0x1, 0x3, 0x2, 0x07, 7},
+{2, 0xF, 0x1, 0x7, 0x4, 0x31, 6},
+{2, 0xF, 0x1, 0xF, 0x8, 0x3B, 7},
+{3, 0x0, 0x0, 0x0, 0x0, 0x00, 3},
+{3, 0x1, 0x0, 0x0, 0x0, 0x04, 4},
+{3, 0x1, 0x1, 0x1, 0x1, 0x3D, 6},
+{3, 0x2, 0x0, 0x0, 0x0, 0x0C, 5},
+{3, 0x2, 0x1, 0x2, 0x2, 0x4F, 7},
+{3, 0x3, 0x0, 0x0, 0x0, 0x1D, 6},
+{3, 0x3, 0x1, 0x1, 0x1, 0x05, 6},
+{3, 0x3, 0x1, 0x3, 0x2, 0x7F, 7},
+{3, 0x4, 0x0, 0x0, 0x0, 0x16, 5},
+{3, 0x4, 0x1, 0x4, 0x4, 0x2D, 6},
+{3, 0x5, 0x0, 0x0, 0x0, 0x06, 5},
+{3, 0x5, 0x1, 0x5, 0x5, 0x1A, 5},
+{3, 0x5, 0x1, 0x5, 0x1, 0x0D, 6},
+{3, 0x5, 0x1, 0x5, 0x4, 0x35, 6},
+{3, 0x6, 0x0, 0x0, 0x0, 0x3F, 7},
+{3, 0x6, 0x1, 0x4, 0x4, 0x5F, 7},
+
+```
+
+---
+
+---
+
+```
+{3, 0x6, 0x1, 0x6, 0x2, 0x1F, 7},
+{3, 0x7, 0x0, 0x0, 0x0, 0x6F, 7},
+{3, 0x7, 0x1, 0x6, 0x6, 0x2F, 7},
+{3, 0x7, 0x1, 0x6, 0x4, 0x15, 6},
+{3, 0x7, 0x1, 0x7, 0x3, 0x77, 7},
+{3, 0x7, 0x1, 0x7, 0x1, 0x25, 6},
+{3, 0x7, 0x1, 0x7, 0x2, 0x0F, 7},
+{3, 0x8, 0x0, 0x0, 0x0, 0x0A, 5},
+{3, 0x8, 0x1, 0x8, 0x8, 0x07, 7},
+{3, 0x9, 0x0, 0x0, 0x0, 0x39, 6},
+{3, 0x9, 0x1, 0x1, 0x1, 0x37, 7},
+{3, 0x9, 0x1, 0x9, 0x8, 0x57, 7},
+{3, 0xA, 0x0, 0x0, 0x0, 0x19, 6},
+{3, 0xA, 0x1, 0x8, 0x8, 0x29, 6},
+{3, 0xA, 0x1, 0xA, 0x2, 0x17, 7},
+{3, 0xB, 0x0, 0x0, 0x0, 0x67, 7},
+{3, 0xB, 0x1, 0xB, 0x1, 0x27, 7},
+{3, 0xB, 0x1, 0x1, 0x1, 0x47, 7},
+{3, 0xB, 0x1, 0x3, 0x2, 0x09, 6},
+{3, 0xB, 0x1, 0xB, 0x8, 0x7B, 7},
+{3, 0xC, 0x0, 0x0, 0x0, 0x31, 6},
+{3, 0xC, 0x1, 0x4, 0x4, 0x11, 6},
+{3, 0xC, 0x1, 0xC, 0x8, 0x3B, 7},
+{3, 0xD, 0x0, 0x0, 0x0, 0x5B, 7},
+{3, 0xD, 0x1, 0x9, 0x9, 0x1B, 7},
+{3, 0xD, 0x1, 0xD, 0x5, 0x2B, 7},
+{3, 0xD, 0x1, 0xD, 0x1, 0x21, 6},
+{3, 0xD, 0x1, 0xD, 0xC, 0x6B, 7},
+{3, 0xD, 0x1, 0xD, 0x4, 0x01, 6},
+{3, 0xD, 0x1, 0xD, 0x8, 0x4B, 7},
+{3, 0xE, 0x0, 0x0, 0x0, 0x0B, 7},
+{3, 0xE, 0x1, 0xE, 0x4, 0x73, 7},
+{3, 0xE, 0x1, 0x4, 0x4, 0x13, 7},
+{3, 0xE, 0x1, 0xC, 0x8, 0x3E, 6},
+{3, 0xE, 0x1, 0xE, 0x2, 0x33, 7},
+{3, 0xF, 0x0, 0x0, 0x0, 0x53, 7},
+{3, 0xF, 0x1, 0xA, 0xA, 0x0E, 6},
+{3, 0xF, 0x1, 0xB, 0x9, 0x63, 7},
+{3, 0xF, 0x1, 0xF, 0xC, 0x03, 7},
+{3, 0xF, 0x1, 0xF, 0x8, 0x12, 5},
+{3, 0xF, 0x1, 0xE, 0x6, 0x23, 7},
+{3, 0xF, 0x1, 0xF, 0x5, 0x1E, 6},
+```
+
+---
+
+---
+
+```
+
+{3, 0xF, 0x1, 0xF, 0x4, 0x02, 5},
+{3, 0xF, 0x1, 0xF, 0x3, 0x43, 7},
+{3, 0xF, 0x1, 0xF, 0x1, 0x1C, 5},
+{3, 0xF, 0x1, 0xF, 0x2, 0x2E, 6},
+{4, 0x0, 0x0, 0x0, 0x0, 0x00, 2},
+{4, 0x1, 0x0, 0x0, 0x0, 0x0E, 4},
+{4, 0x1, 0x1, 0x1, 0x1, 0x3F, 7},
+{4, 0x2, 0x0, 0x0, 0x0, 0x06, 4},
+{4, 0x2, 0x1, 0x2, 0x2, 0x1B, 6},
+{4, 0x3, 0x0, 0x0, 0x0, 0x2B, 6},
+{4, 0x3, 0x1, 0x2, 0x2, 0x3D, 6},
+{4, 0x3, 0x1, 0x3, 0x1, 0x7F, 7},
+{4, 0x4, 0x0, 0x0, 0x0, 0x0A, 4},
+{4, 0x4, 0x1, 0x4, 0x4, 0x5F, 7},
+{4, 0x5, 0x0, 0x0, 0x0, 0x0B, 6},
+{4, 0x5, 0x1, 0x0, 0x0, 0x33, 6},
+{4, 0x6, 0x0, 0x0, 0x0, 0x13, 6},
+{4, 0x6, 0x1, 0x0, 0x0, 0x23, 6},
+{4, 0x7, 0x0, 0x0, 0x0, 0x1F, 7},
+{4, 0x7, 0x1, 0x4, 0x4, 0x6F, 7},
+{4, 0x7, 0x1, 0x4, 0x0, 0x03, 6},
+{4, 0x8, 0x0, 0x0, 0x0, 0x02, 4},
+{4, 0x8, 0x1, 0x8, 0x8, 0x1D, 6},
+{4, 0x9, 0x0, 0x0, 0x0, 0x11, 6},
+{4, 0x9, 0x1, 0x0, 0x0, 0x77, 7},
+{4, 0xA, 0x0, 0x0, 0x0, 0x01, 5},
+{4, 0xA, 0x1, 0xA, 0xA, 0x2F, 7},
+{4, 0xA, 0x1, 0xA, 0x2, 0x2D, 6},
+{4, 0xA, 0x1, 0xA, 0x8, 0x0D, 6},
+{4, 0xB, 0x0, 0x0, 0x0, 0x4F, 7},
+{4, 0xB, 0x1, 0xB, 0x2, 0x0F, 7},
+{4, 0xB, 0x1, 0x0, 0x0, 0x35, 6},
+{4, 0xC, 0x0, 0x0, 0x0, 0x15, 6},
+{4, 0xC, 0x1, 0x8, 0x8, 0x25, 6},
+{4, 0xC, 0x1, 0xC, 0x4, 0x37, 7},
+{4, 0xD, 0x0, 0x0, 0x0, 0x57, 7},
+{4, 0xD, 0x1, 0x1, 0x1, 0x07, 7},
+{4, 0xD, 0x1, 0x1, 0x0, 0x05, 6},
+{4, 0xE, 0x0, 0x0, 0x0, 0x17, 7},
+{4, 0xE, 0x1, 0x4, 0x4, 0x39, 6},
+{4, 0xE, 0x1, 0xC, 0x8, 0x19, 6},
+{4, 0xE, 0x1, 0xE, 0x2, 0x67, 7},
+
+```
+
+---
+
+---
+
+{4, 0xF, 0x0, 0x0, 0x0, 0x27, 7},  
+{4, 0xF, 0x1, 0x9, 0x9, 0x47, 7},  
+{4, 0xF, 0x1, 0x9, 0x1, 0x29, 6},  
+{4, 0xF, 0x1, 0x7, 0x6, 0x7B, 7},  
+{4, 0xF, 0x1, 0x7, 0x2, 0x09, 6},  
+{4, 0xF, 0x1, 0xB, 0x8, 0x31, 6},  
+{4, 0xF, 0x1, 0xF, 0x4, 0x3B, 7},  
+{5, 0x0, 0x0, 0x0, 0x0, 0x00, 3},  
+{5, 0x1, 0x0, 0x0, 0x0, 0x1A, 5},  
+{5, 0x1, 0x1, 0x1, 0x1, 0x7F, 7},  
+{5, 0x2, 0x0, 0x0, 0x0, 0x0A, 5},  
+{5, 0x2, 0x1, 0x2, 0x2, 0x1D, 6},  
+{5, 0x3, 0x0, 0x0, 0x0, 0x2D, 6},  
+{5, 0x3, 0x1, 0x3, 0x3, 0x5F, 7},  
+{5, 0x3, 0x1, 0x3, 0x2, 0x39, 6},  
+{5, 0x3, 0x1, 0x3, 0x1, 0x3F, 7},  
+{5, 0x4, 0x0, 0x0, 0x0, 0x12, 5},  
+{5, 0x4, 0x1, 0x4, 0x4, 0x1F, 7},  
+{5, 0x5, 0x0, 0x0, 0x0, 0x0D, 6},  
+{5, 0x5, 0x1, 0x4, 0x4, 0x35, 6},  
+{5, 0x5, 0x1, 0x5, 0x1, 0x6F, 7},  
+{5, 0x6, 0x0, 0x0, 0x0, 0x15, 6},  
+{5, 0x6, 0x1, 0x2, 0x2, 0x25, 6},  
+{5, 0x6, 0x1, 0x6, 0x4, 0x2F, 7},  
+{5, 0x7, 0x0, 0x0, 0x0, 0x4F, 7},  
+{5, 0x7, 0x1, 0x6, 0x6, 0x57, 7},  
+{5, 0x7, 0x1, 0x6, 0x4, 0x05, 6},  
+{5, 0x7, 0x1, 0x7, 0x3, 0x0F, 7},  
+{5, 0x7, 0x1, 0x7, 0x2, 0x77, 7},  
+{5, 0x7, 0x1, 0x7, 0x1, 0x37, 7},  
+{5, 0x8, 0x0, 0x0, 0x0, 0x02, 5},  
+{5, 0x8, 0x1, 0x8, 0x8, 0x19, 6},  
+{5, 0x9, 0x0, 0x0, 0x0, 0x26, 6},  
+{5, 0x9, 0x1, 0x8, 0x8, 0x17, 7},  
+{5, 0x9, 0x1, 0x9, 0x1, 0x67, 7},  
+{5, 0xA, 0x0, 0x0, 0x0, 0x1C, 5},  
+{5, 0xA, 0x1, 0xA, 0xA, 0x29, 6},  
+{5, 0xA, 0x1, 0xA, 0x2, 0x09, 6},  
+{5, 0xA, 0x1, 0xA, 0x8, 0x31, 6},  
+{5, 0xB, 0x0, 0x0, 0x0, 0x27, 7},  
+{5, 0xB, 0x1, 0x9, 0x9, 0x07, 7},  
+{5, 0xB, 0x1, 0x9, 0x8, 0x11, 6},
+
+---
+
+---
+
+```
+
+{5, 0xB, 0x1, 0xB, 0x3, 0x47, 7},
+{5, 0xB, 0x1, 0xB, 0x2, 0x21, 6},
+{5, 0xB, 0x1, 0xB, 0x1, 0x7B, 7},
+{5, 0xC, 0x0, 0x0, 0x0, 0x01, 6},
+{5, 0xC, 0x1, 0x8, 0x8, 0x3E, 6},
+{5, 0xC, 0x1, 0xC, 0x4, 0x3B, 7},
+{5, 0xD, 0x0, 0x0, 0x0, 0x5B, 7},
+{5, 0xD, 0x1, 0x9, 0x9, 0x6B, 7},
+{5, 0xD, 0x1, 0x9, 0x8, 0x1E, 6},
+{5, 0xD, 0x1, 0xD, 0x5, 0x1B, 7},
+{5, 0xD, 0x1, 0xD, 0x4, 0x2E, 6},
+{5, 0xD, 0x1, 0xD, 0x1, 0x2B, 7},
+{5, 0xE, 0x0, 0x0, 0x0, 0x4B, 7},
+{5, 0xE, 0x1, 0x6, 0x6, 0x0B, 7},
+{5, 0xE, 0x1, 0xE, 0xA, 0x33, 7},
+{5, 0xE, 0x1, 0xE, 0x2, 0x0E, 6},
+{5, 0xE, 0x1, 0xE, 0xC, 0x73, 7},
+{5, 0xE, 0x1, 0xE, 0x8, 0x36, 6},
+{5, 0xE, 0x1, 0xE, 0x4, 0x53, 7},
+{5, 0xF, 0x0, 0x0, 0x0, 0x13, 7},
+{5, 0xF, 0x1, 0x7, 0x7, 0x43, 7},
+{5, 0xF, 0x1, 0x7, 0x6, 0x16, 6},
+{5, 0xF, 0x1, 0x7, 0x5, 0x63, 7},
+{5, 0xF, 0x1, 0xF, 0xC, 0x23, 7},
+{5, 0xF, 0x1, 0xF, 0x4, 0x0C, 5},
+{5, 0xF, 0x1, 0xD, 0x9, 0x03, 7},
+{5, 0xF, 0x1, 0xF, 0xA, 0x3D, 7},
+{5, 0xF, 0x1, 0xF, 0x8, 0x14, 5},
+{5, 0xF, 0x1, 0xF, 0x3, 0x7D, 7},
+{5, 0xF, 0x1, 0xF, 0x2, 0x04, 5},
+{5, 0xF, 0x1, 0xF, 0x1, 0x06, 6},
+{6, 0x0, 0x0, 0x0, 0x0, 0x00, 3},
+{6, 0x1, 0x0, 0x0, 0x0, 0x04, 4},
+{6, 0x1, 0x1, 0x1, 0x1, 0x03, 6},
+{6, 0x2, 0x0, 0x0, 0x0, 0x0C, 5},
+{6, 0x2, 0x1, 0x2, 0x2, 0x0D, 6},
+{6, 0x3, 0x0, 0x0, 0x0, 0x1A, 5},
+{6, 0x3, 0x1, 0x3, 0x3, 0x3D, 6},
+{6, 0x3, 0x1, 0x3, 0x1, 0x1D, 6},
+{6, 0x3, 0x1, 0x3, 0x2, 0x2D, 6},
+{6, 0x4, 0x0, 0x0, 0x0, 0x0A, 5},
+{6, 0x4, 0x1, 0x4, 0x4, 0x3F, 7},
+
+```
+
+---
+
+---
+
+{6, 0x5, 0x0, 0x0, 0x0, 0x35, 6},  
+{6, 0x5, 0x1, 0x1, 0x1, 0x15, 6},  
+{6, 0x5, 0x1, 0x5, 0x4, 0x7F, 7},  
+{6, 0x6, 0x0, 0x0, 0x0, 0x25, 6},  
+{6, 0x6, 0x1, 0x2, 0x2, 0x5F, 7},  
+{6, 0x6, 0x1, 0x6, 0x4, 0x1F, 7},  
+{6, 0x7, 0x0, 0x0, 0x0, 0x6F, 7},  
+{6, 0x7, 0x1, 0x6, 0x6, 0x4F, 7},  
+{6, 0x7, 0x1, 0x6, 0x4, 0x05, 6},  
+{6, 0x7, 0x1, 0x7, 0x3, 0x2F, 7},  
+{6, 0x7, 0x1, 0x7, 0x1, 0x36, 6},  
+{6, 0x7, 0x1, 0x7, 0x2, 0x77, 7},  
+{6, 0x8, 0x0, 0x0, 0x0, 0x12, 5},  
+{6, 0x8, 0x1, 0x8, 0x8, 0x0F, 7},  
+{6, 0x9, 0x0, 0x0, 0x0, 0x39, 6},  
+{6, 0x9, 0x1, 0x1, 0x1, 0x37, 7},  
+{6, 0x9, 0x1, 0x9, 0x8, 0x57, 7},  
+{6, 0xA, 0x0, 0x0, 0x0, 0x19, 6},  
+{6, 0xA, 0x1, 0x2, 0x2, 0x29, 6},  
+{6, 0xA, 0x1, 0xA, 0x8, 0x17, 7},  
+{6, 0xB, 0x0, 0x0, 0x0, 0x67, 7},  
+{6, 0xB, 0x1, 0x9, 0x9, 0x47, 7},  
+{6, 0xB, 0x1, 0x9, 0x1, 0x09, 6},  
+{6, 0xB, 0x1, 0xB, 0xA, 0x27, 7},  
+{6, 0xB, 0x1, 0xB, 0x2, 0x31, 6},  
+{6, 0xB, 0x1, 0xB, 0x8, 0x7B, 7},  
+{6, 0xC, 0x0, 0x0, 0x0, 0x11, 6},  
+{6, 0xC, 0x1, 0xC, 0xC, 0x07, 7},  
+{6, 0xC, 0x1, 0xC, 0x8, 0x21, 6},  
+{6, 0xC, 0x1, 0xC, 0x4, 0x3B, 7},  
+{6, 0xD, 0x0, 0x0, 0x0, 0x5B, 7},  
+{6, 0xD, 0x1, 0x5, 0x5, 0x33, 7},  
+{6, 0xD, 0x1, 0x5, 0x4, 0x01, 6},  
+{6, 0xD, 0x1, 0xC, 0x8, 0x1B, 7},  
+{6, 0xD, 0x1, 0xD, 0x1, 0x6B, 7},  
+{6, 0xE, 0x0, 0x0, 0x0, 0x2B, 7},  
+{6, 0xE, 0x1, 0xE, 0x2, 0x4B, 7},  
+{6, 0xE, 0x1, 0x2, 0x2, 0x0B, 7},  
+{6, 0xE, 0x1, 0xE, 0xC, 0x73, 7},  
+{6, 0xE, 0x1, 0xE, 0x8, 0x3E, 6},  
+{6, 0xE, 0x1, 0xE, 0x4, 0x53, 7},  
+{6, 0xF, 0x0, 0x0, 0x0, 0x13, 7},
+
+---
+
+---
+
+```
+
+{6, 0xF, 0x1, 0x6, 0x6, 0x1E, 6},
+{6, 0xF, 0x1, 0xE, 0xA, 0x2E, 6},
+{6, 0xF, 0x1, 0xF, 0x3, 0x0E, 6},
+{6, 0xF, 0x1, 0xF, 0x2, 0x02, 5},
+{6, 0xF, 0x1, 0xB, 0x9, 0x63, 7},
+{6, 0xF, 0x1, 0xF, 0xC, 0x16, 6},
+{6, 0xF, 0x1, 0xF, 0x8, 0x06, 6},
+{6, 0xF, 0x1, 0xF, 0x5, 0x23, 7},
+{6, 0xF, 0x1, 0xF, 0x1, 0x1C, 5},
+{6, 0xF, 0x1, 0xF, 0x4, 0x26, 6},
+{7, 0x0, 0x0, 0x0, 0x0, 0x12, 5},
+{7, 0x1, 0x0, 0x0, 0x0, 0x05, 6},
+{7, 0x1, 0x1, 0x1, 0x1, 0x7F, 7},
+{7, 0x2, 0x0, 0x0, 0x0, 0x39, 6},
+{7, 0x2, 0x1, 0x2, 0x2, 0x3F, 7},
+{7, 0x3, 0x0, 0x0, 0x0, 0x5F, 7},
+{7, 0x3, 0x1, 0x3, 0x3, 0x1F, 7},
+{7, 0x3, 0x1, 0x3, 0x2, 0x6F, 7},
+{7, 0x3, 0x1, 0x3, 0x1, 0x2F, 7},
+{7, 0x4, 0x0, 0x0, 0x0, 0x4F, 7},
+{7, 0x4, 0x1, 0x4, 0x4, 0x0F, 7},
+{7, 0x5, 0x0, 0x0, 0x0, 0x57, 7},
+{7, 0x5, 0x1, 0x1, 0x1, 0x19, 6},
+{7, 0x5, 0x1, 0x5, 0x4, 0x77, 7},
+{7, 0x6, 0x0, 0x0, 0x0, 0x37, 7},
+{7, 0x6, 0x1, 0x0, 0x0, 0x29, 6},
+{7, 0x7, 0x0, 0x0, 0x0, 0x17, 7},
+{7, 0x7, 0x1, 0x6, 0x6, 0x67, 7},
+{7, 0x7, 0x1, 0x7, 0x3, 0x27, 7},
+{7, 0x7, 0x1, 0x7, 0x2, 0x47, 7},
+{7, 0x7, 0x1, 0x7, 0x5, 0x1B, 7},
+{7, 0x7, 0x1, 0x7, 0x1, 0x09, 6},
+{7, 0x7, 0x1, 0x7, 0x4, 0x07, 7},
+{7, 0x8, 0x0, 0x0, 0x0, 0x7B, 7},
+{7, 0x8, 0x1, 0x8, 0x8, 0x3B, 7},
+{7, 0x9, 0x0, 0x0, 0x0, 0x5B, 7},
+{7, 0x9, 0x1, 0x0, 0x0, 0x31, 6},
+{7, 0xA, 0x0, 0x0, 0x0, 0x53, 7},
+{7, 0xA, 0x1, 0x2, 0x2, 0x11, 6},
+{7, 0xA, 0x1, 0xA, 0x8, 0x6B, 7},
+{7, 0xB, 0x0, 0x0, 0x0, 0x2B, 7},
+{7, 0xB, 0x1, 0x9, 0x9, 0x4B, 7},
+
+```
+
+---
+
+---
+
+```
+
+{7, 0xB, 0x1, 0xB, 0x3, 0x0B, 7},
+{7, 0xB, 0x1, 0xB, 0x1, 0x73, 7},
+{7, 0xB, 0x1, 0xB, 0xA, 0x33, 7},
+{7, 0xB, 0x1, 0xB, 0x2, 0x21, 6},
+{7, 0xB, 0x1, 0xB, 0x8, 0x13, 7},
+{7, 0xC, 0x0, 0x0, 0x0, 0x63, 7},
+{7, 0xC, 0x1, 0x8, 0x8, 0x23, 7},
+{7, 0xC, 0x1, 0xC, 0x4, 0x43, 7},
+{7, 0xD, 0x0, 0x0, 0x0, 0x03, 7},
+{7, 0xD, 0x1, 0x9, 0x9, 0x7D, 7},
+{7, 0xD, 0x1, 0xD, 0x5, 0x5D, 7},
+{7, 0xD, 0x1, 0xD, 0x1, 0x01, 6},
+{7, 0xD, 0x1, 0xD, 0xC, 0x3D, 7},
+{7, 0xD, 0x1, 0xD, 0x4, 0x3E, 6},
+{7, 0xD, 0x1, 0xD, 0x8, 0x1D, 7},
+{7, 0xE, 0x0, 0x0, 0x0, 0x6D, 7},
+{7, 0xE, 0x1, 0x6, 0x6, 0x2D, 7},
+{7, 0xE, 0x1, 0xE, 0xA, 0x0D, 7},
+{7, 0xE, 0x1, 0xE, 0x2, 0x1E, 6},
+{7, 0xE, 0x1, 0xE, 0xC, 0x4D, 7},
+{7, 0xE, 0x1, 0xE, 0x8, 0x0E, 6},
+{7, 0xE, 0x1, 0xE, 0x4, 0x75, 7},
+{7, 0xF, 0x0, 0x0, 0x0, 0x15, 7},
+{7, 0xF, 0x1, 0xF, 0xF, 0x06, 5},
+{7, 0xF, 0x1, 0xF, 0xD, 0x35, 7},
+{7, 0xF, 0x1, 0xF, 0x7, 0x55, 7},
+{7, 0xF, 0x1, 0xF, 0x5, 0x1A, 5},
+{7, 0xF, 0x1, 0xF, 0xB, 0x25, 7},
+{7, 0xF, 0x1, 0xF, 0x3, 0x0A, 5},
+{7, 0xF, 0x1, 0xF, 0x9, 0x2E, 6},
+{7, 0xF, 0x1, 0xF, 0x1, 0x00, 4},
+{7, 0xF, 0x1, 0xF, 0xE, 0x65, 7},
+{7, 0xF, 0x1, 0xF, 0x6, 0x36, 6},
+{7, 0xF, 0x1, 0xF, 0xA, 0x02, 5},
+{7, 0xF, 0x1, 0xF, 0x2, 0x0C, 4},
+{7, 0xF, 0x1, 0xF, 0xC, 0x16, 6},
+{7, 0xF, 0x1, 0xF, 0x8, 0x04, 4},
+{7, 0xF, 0x1, 0xF, 0x4, 0x08, 4}}
+
+```
+
+---
+
+CxtVLC\_table\_1 is specified as follows:
+
+---
+
+```
+
+CxtVLC_table_1 = {{0, 0x1, 0x0, 0x0, 0x0, 0x00, 3},
+{0, 0x1, 0x1, 0x1, 0x1, 0x27, 6},
+
+```
+
+---
+
+---
+
+```
+
+{0, 0x2, 0x0, 0x0, 0x0, 0x06, 3},
+{0, 0x2, 0x1, 0x2, 0x2, 0x17, 6},
+{0, 0x3, 0x0, 0x0, 0x0, 0x0D, 5},
+{0, 0x3, 0x1, 0x0, 0x0, 0x3B, 6},
+{0, 0x4, 0x0, 0x0, 0x0, 0x02, 3},
+{0, 0x4, 0x1, 0x4, 0x4, 0x07, 6},
+{0, 0x5, 0x0, 0x0, 0x0, 0x15, 5},
+{0, 0x5, 0x1, 0x0, 0x0, 0x2B, 6},
+{0, 0x6, 0x0, 0x0, 0x0, 0x01, 5},
+{0, 0x6, 0x1, 0x0, 0x0, 0x7F, 7},
+{0, 0x7, 0x0, 0x0, 0x0, 0x1F, 7},
+{0, 0x7, 0x1, 0x0, 0x0, 0x1B, 6},
+{0, 0x8, 0x0, 0x0, 0x0, 0x04, 3},
+{0, 0x8, 0x1, 0x8, 0x8, 0x05, 5},
+{0, 0x9, 0x0, 0x0, 0x0, 0x19, 5},
+{0, 0x9, 0x1, 0x0, 0x0, 0x13, 6},
+{0, 0xA, 0x0, 0x0, 0x0, 0x09, 5},
+{0, 0xA, 0x1, 0x8, 0x8, 0x0B, 6},
+{0, 0xA, 0x1, 0xA, 0x2, 0x3F, 7},
+{0, 0xB, 0x0, 0x0, 0x0, 0x5F, 7},
+{0, 0xB, 0x1, 0x0, 0x0, 0x33, 6},
+{0, 0xC, 0x0, 0x0, 0x0, 0x11, 5},
+{0, 0xC, 0x1, 0x8, 0x8, 0x23, 6},
+{0, 0xC, 0x1, 0xC, 0x4, 0x6F, 7},
+{0, 0xD, 0x0, 0x0, 0x0, 0x0F, 7},
+{0, 0xD, 0x1, 0x0, 0x0, 0x03, 6},
+{0, 0xE, 0x0, 0x0, 0x0, 0x2F, 7},
+{0, 0xE, 0x1, 0x4, 0x4, 0x4F, 7},
+{0, 0xE, 0x1, 0x4, 0x0, 0x3D, 6},
+{0, 0xF, 0x0, 0x0, 0x0, 0x77, 7},
+{0, 0xF, 0x1, 0x1, 0x1, 0x37, 7},
+{0, 0xF, 0x1, 0x1, 0x0, 0x1D, 6},
+{1, 0x0, 0x0, 0x0, 0x0, 0x00, 1},
+{1, 0x1, 0x0, 0x0, 0x0, 0x05, 4},
+{1, 0x1, 0x1, 0x1, 0x1, 0x7F, 7},
+{1, 0x2, 0x0, 0x0, 0x0, 0x09, 4},
+{1, 0x2, 0x1, 0x2, 0x2, 0x1F, 7},
+{1, 0x3, 0x0, 0x0, 0x0, 0x1D, 5},
+{1, 0x3, 0x1, 0x1, 0x1, 0x3F, 7},
+{1, 0x3, 0x1, 0x3, 0x2, 0x5F, 7},
+{1, 0x4, 0x0, 0x0, 0x0, 0x0D, 5},
+{1, 0x4, 0x1, 0x4, 0x4, 0x37, 7},
+
+```
+
+---
+
+---
+
+```
+
+{1, 0x5, 0x0, 0x0, 0x0, 0x03, 6},
+{1, 0x5, 0x1, 0x0, 0x0, 0x6F, 7},
+{1, 0x6, 0x0, 0x0, 0x0, 0x2F, 7},
+{1, 0x6, 0x1, 0x0, 0x0, 0x4F, 7},
+{1, 0x7, 0x0, 0x0, 0x0, 0x0F, 7},
+{1, 0x7, 0x1, 0x0, 0x0, 0x77, 7},
+{1, 0x8, 0x0, 0x0, 0x0, 0x01, 4},
+{1, 0x8, 0x1, 0x8, 0x8, 0x17, 7},
+{1, 0x9, 0x0, 0x0, 0x0, 0x0B, 6},
+{1, 0x9, 0x1, 0x0, 0x0, 0x57, 7},
+{1, 0xA, 0x0, 0x0, 0x0, 0x33, 6},
+{1, 0xA, 0x1, 0x0, 0x0, 0x67, 7},
+{1, 0xB, 0x0, 0x0, 0x0, 0x27, 7},
+{1, 0xB, 0x1, 0x0, 0x0, 0x2B, 7},
+{1, 0xC, 0x0, 0x0, 0x0, 0x13, 6},
+{1, 0xC, 0x1, 0x0, 0x0, 0x47, 7},
+{1, 0xD, 0x0, 0x0, 0x0, 0x07, 7},
+{1, 0xD, 0x1, 0x0, 0x0, 0x7B, 7},
+{1, 0xE, 0x0, 0x0, 0x0, 0x3B, 7},
+{1, 0xE, 0x1, 0x0, 0x0, 0x5B, 7},
+{1, 0xF, 0x0, 0x0, 0x0, 0x1B, 7},
+{1, 0xF, 0x1, 0x4, 0x4, 0x6B, 7},
+{1, 0xF, 0x1, 0x4, 0x0, 0x23, 6},
+{2, 0x0, 0x0, 0x0, 0x0, 0x00, 1},
+{2, 0x1, 0x0, 0x0, 0x0, 0x09, 4},
+{2, 0x1, 0x1, 0x1, 0x1, 0x7F, 7},
+{2, 0x2, 0x0, 0x0, 0x0, 0x01, 4},
+{2, 0x2, 0x1, 0x2, 0x2, 0x23, 6},
+{2, 0x3, 0x0, 0x0, 0x0, 0x3D, 6},
+{2, 0x3, 0x1, 0x2, 0x2, 0x3F, 7},
+{2, 0x3, 0x1, 0x3, 0x1, 0x1F, 7},
+{2, 0x4, 0x0, 0x0, 0x0, 0x15, 5},
+{2, 0x4, 0x1, 0x4, 0x4, 0x5F, 7},
+{2, 0x5, 0x0, 0x0, 0x0, 0x03, 6},
+{2, 0x5, 0x1, 0x0, 0x0, 0x6F, 7},
+{2, 0x6, 0x0, 0x0, 0x0, 0x2F, 7},
+{2, 0x6, 0x1, 0x0, 0x0, 0x4F, 7},
+{2, 0x7, 0x0, 0x0, 0x0, 0x0F, 7},
+{2, 0x7, 0x1, 0x0, 0x0, 0x17, 7},
+{2, 0x8, 0x0, 0x0, 0x0, 0x05, 5},
+{2, 0x8, 0x1, 0x8, 0x8, 0x77, 7},
+{2, 0x9, 0x0, 0x0, 0x0, 0x37, 7},
+
+```
+
+---
+
+---
+
+```
+
+{2, 0x9, 0x1, 0x0, 0x0, 0x57, 7},
+{2, 0xA, 0x0, 0x0, 0x0, 0x1D, 6},
+{2, 0xA, 0x1, 0xA, 0xA, 0x7B, 7},
+{2, 0xA, 0x1, 0xA, 0x2, 0x2D, 6},
+{2, 0xA, 0x1, 0xA, 0x8, 0x67, 7},
+{2, 0xB, 0x0, 0x0, 0x0, 0x27, 7},
+{2, 0xB, 0x1, 0xB, 0x2, 0x47, 7},
+{2, 0xB, 0x1, 0x0, 0x0, 0x07, 7},
+{2, 0xC, 0x0, 0x0, 0x0, 0x0D, 6},
+{2, 0xC, 0x1, 0x0, 0x0, 0x3B, 7},
+{2, 0xD, 0x0, 0x0, 0x0, 0x5B, 7},
+{2, 0xD, 0x1, 0x0, 0x0, 0x1B, 7},
+{2, 0xE, 0x0, 0x0, 0x0, 0x6B, 7},
+{2, 0xE, 0x1, 0x4, 0x4, 0x2B, 7},
+{2, 0xE, 0x1, 0x4, 0x0, 0x4B, 7},
+{2, 0xF, 0x0, 0x0, 0x0, 0x0B, 7},
+{2, 0xF, 0x1, 0x4, 0x4, 0x73, 7},
+{2, 0xF, 0x1, 0x5, 0x1, 0x33, 7},
+{2, 0xF, 0x1, 0x7, 0x2, 0x53, 7},
+{2, 0xF, 0x1, 0xF, 0x8, 0x13, 7},
+{3, 0x0, 0x0, 0x0, 0x0, 0x00, 2},
+{3, 0x1, 0x0, 0x0, 0x0, 0x0A, 4},
+{3, 0x1, 0x1, 0x1, 0x1, 0x0B, 6},
+{3, 0x2, 0x0, 0x0, 0x0, 0x02, 4},
+{3, 0x2, 0x1, 0x2, 0x2, 0x23, 6},
+{3, 0x3, 0x0, 0x0, 0x0, 0x0E, 5},
+{3, 0x3, 0x1, 0x3, 0x3, 0x7F, 7},
+{3, 0x3, 0x1, 0x3, 0x2, 0x33, 6},
+{3, 0x3, 0x1, 0x3, 0x1, 0x13, 6},
+{3, 0x4, 0x0, 0x0, 0x0, 0x16, 5},
+{3, 0x4, 0x1, 0x4, 0x4, 0x3F, 7},
+{3, 0x5, 0x0, 0x0, 0x0, 0x03, 6},
+{3, 0x5, 0x1, 0x1, 0x1, 0x3D, 6},
+{3, 0x5, 0x1, 0x5, 0x4, 0x1F, 7},
+{3, 0x6, 0x0, 0x0, 0x0, 0x1D, 6},
+{3, 0x6, 0x1, 0x0, 0x0, 0x5F, 7},
+{3, 0x7, 0x0, 0x0, 0x0, 0x2D, 6},
+{3, 0x7, 0x1, 0x4, 0x4, 0x2F, 7},
+{3, 0x7, 0x1, 0x5, 0x1, 0x1E, 6},
+{3, 0x7, 0x1, 0x7, 0x2, 0x6F, 7},
+{3, 0x8, 0x0, 0x0, 0x0, 0x06, 5},
+{3, 0x8, 0x1, 0x8, 0x8, 0x4F, 7},
+
+```
+
+---
+
+---
+
+```
+
+{3, 0x9, 0x0, 0x0, 0x0, 0x0D, 6},
+{3, 0x9, 0x1, 0x0, 0x0, 0x35, 6},
+{3, 0xA, 0x0, 0x0, 0x0, 0x15, 6},
+{3, 0xA, 0x1, 0x2, 0x2, 0x25, 6},
+{3, 0xA, 0x1, 0xA, 0x8, 0x0F, 7},
+{3, 0xB, 0x0, 0x0, 0x0, 0x05, 6},
+{3, 0xB, 0x1, 0x8, 0x8, 0x39, 6},
+{3, 0xB, 0x1, 0xB, 0x3, 0x17, 7},
+{3, 0xB, 0x1, 0xB, 0x2, 0x19, 6},
+{3, 0xB, 0x1, 0xB, 0x1, 0x77, 7},
+{3, 0xC, 0x0, 0x0, 0x0, 0x29, 6},
+{3, 0xC, 0x1, 0x0, 0x0, 0x09, 6},
+{3, 0xD, 0x0, 0x0, 0x0, 0x37, 7},
+{3, 0xD, 0x1, 0x4, 0x4, 0x57, 7},
+{3, 0xD, 0x1, 0x4, 0x0, 0x31, 6},
+{3, 0xE, 0x0, 0x0, 0x0, 0x67, 7},
+{3, 0xE, 0x1, 0x4, 0x4, 0x27, 7},
+{3, 0xE, 0x1, 0xC, 0x8, 0x47, 7},
+{3, 0xE, 0x1, 0xE, 0x2, 0x6B, 7},
+{3, 0xF, 0x0, 0x0, 0x0, 0x11, 6},
+{3, 0xF, 0x1, 0x6, 0x6, 0x07, 7},
+{3, 0xF, 0x1, 0x7, 0x3, 0x7B, 7},
+{3, 0xF, 0x1, 0xF, 0xA, 0x3B, 7},
+{3, 0xF, 0x1, 0xF, 0x2, 0x21, 6},
+{3, 0xF, 0x1, 0xF, 0x8, 0x01, 6},
+{3, 0xF, 0x1, 0xA, 0x8, 0x5B, 7},
+{3, 0xF, 0x1, 0xF, 0x5, 0x1B, 7},
+{3, 0xF, 0x1, 0xF, 0x1, 0x3E, 6},
+{3, 0xF, 0x1, 0xF, 0x4, 0x2B, 7},
+{4, 0x0, 0x0, 0x0, 0x0, 0x00, 1},
+{4, 0x1, 0x0, 0x0, 0x0, 0x0D, 5},
+{4, 0x1, 0x1, 0x1, 0x1, 0x7F, 7},
+{4, 0x2, 0x0, 0x0, 0x0, 0x15, 5},
+{4, 0x2, 0x1, 0x2, 0x2, 0x3F, 7},
+{4, 0x3, 0x0, 0x0, 0x0, 0x5F, 7},
+{4, 0x3, 0x1, 0x0, 0x0, 0x6F, 7},
+{4, 0x4, 0x0, 0x0, 0x0, 0x09, 4},
+{4, 0x4, 0x1, 0x4, 0x4, 0x23, 6},
+{4, 0x5, 0x0, 0x0, 0x0, 0x33, 6},
+{4, 0x5, 0x1, 0x0, 0x0, 0x1F, 7},
+{4, 0x6, 0x0, 0x0, 0x0, 0x13, 6},
+{4, 0x6, 0x1, 0x0, 0x0, 0x2F, 7},
+
+```
+
+---
+
+---
+
+```
+
+{4, 0x7, 0x0, 0x0, 0x0, 0x4F, 7},
+{4, 0x7, 0x1, 0x0, 0x0, 0x57, 7},
+{4, 0x8, 0x0, 0x0, 0x0, 0x01, 4},
+{4, 0x8, 0x1, 0x8, 0x8, 0x0F, 7},
+{4, 0x9, 0x0, 0x0, 0x0, 0x77, 7},
+{4, 0x9, 0x1, 0x0, 0x0, 0x37, 7},
+{4, 0xA, 0x0, 0x0, 0x0, 0x1D, 6},
+{4, 0xA, 0x1, 0x0, 0x0, 0x17, 7},
+{4, 0xB, 0x0, 0x0, 0x0, 0x67, 7},
+{4, 0xB, 0x1, 0x0, 0x0, 0x6B, 7},
+{4, 0xC, 0x0, 0x0, 0x0, 0x05, 5},
+{4, 0xC, 0x1, 0xC, 0xC, 0x27, 7},
+{4, 0xC, 0x1, 0xC, 0x8, 0x47, 7},
+{4, 0xC, 0x1, 0xC, 0x4, 0x07, 7},
+{4, 0xD, 0x0, 0x0, 0x0, 0x7B, 7},
+{4, 0xD, 0x1, 0x0, 0x0, 0x3B, 7},
+{4, 0xE, 0x0, 0x0, 0x0, 0x5B, 7},
+{4, 0xE, 0x1, 0x2, 0x2, 0x1B, 7},
+{4, 0xE, 0x1, 0x2, 0x0, 0x03, 6},
+{4, 0xF, 0x0, 0x0, 0x0, 0x2B, 7},
+{4, 0xF, 0x1, 0x1, 0x1, 0x4B, 7},
+{4, 0xF, 0x1, 0x3, 0x2, 0x0B, 7},
+{4, 0xF, 0x1, 0x3, 0x0, 0x3D, 6},
+{5, 0x0, 0x0, 0x0, 0x0, 0x00, 2},
+{5, 0x1, 0x0, 0x0, 0x0, 0x1E, 5},
+{5, 0x1, 0x1, 0x1, 0x1, 0x3B, 6},
+{5, 0x2, 0x0, 0x0, 0x0, 0x0A, 5},
+{5, 0x2, 0x1, 0x2, 0x2, 0x3F, 7},
+{5, 0x3, 0x0, 0x0, 0x0, 0x1B, 6},
+{5, 0x3, 0x1, 0x0, 0x0, 0x0B, 6},
+{5, 0x4, 0x0, 0x0, 0x0, 0x02, 4},
+{5, 0x4, 0x1, 0x4, 0x4, 0x2B, 6},
+{5, 0x5, 0x0, 0x0, 0x0, 0x0E, 5},
+{5, 0x5, 0x1, 0x4, 0x4, 0x33, 6},
+{5, 0x5, 0x1, 0x5, 0x1, 0x7F, 7},
+{5, 0x6, 0x0, 0x0, 0x0, 0x13, 6},
+{5, 0x6, 0x1, 0x0, 0x0, 0x6F, 7},
+{5, 0x7, 0x0, 0x0, 0x0, 0x23, 6},
+{5, 0x7, 0x1, 0x2, 0x2, 0x5F, 7},
+{5, 0x7, 0x1, 0x2, 0x0, 0x15, 6},
+{5, 0x8, 0x0, 0x0, 0x0, 0x16, 5},
+{5, 0x8, 0x1, 0x8, 0x8, 0x03, 6},
+
+```
+
+---
+
+---
+
+```
+
+{5, 0x9, 0x0, 0x0, 0x0, 0x3D, 6},
+{5, 0x9, 0x1, 0x0, 0x0, 0x1F, 7},
+{5, 0xA, 0x0, 0x0, 0x0, 0x1D, 6},
+{5, 0xA, 0x1, 0x0, 0x0, 0x2D, 6},
+{5, 0xB, 0x0, 0x0, 0x0, 0x0D, 6},
+{5, 0xB, 0x1, 0x1, 0x1, 0x4F, 7},
+{5, 0xB, 0x1, 0x1, 0x0, 0x35, 6},
+{5, 0xC, 0x0, 0x0, 0x0, 0x06, 5},
+{5, 0xC, 0x1, 0x4, 0x4, 0x25, 6},
+{5, 0xC, 0x1, 0xC, 0x8, 0x2F, 7},
+{5, 0xD, 0x0, 0x0, 0x0, 0x05, 6},
+{5, 0xD, 0x1, 0x1, 0x1, 0x77, 7},
+{5, 0xD, 0x1, 0x5, 0x4, 0x39, 6},
+{5, 0xD, 0x1, 0xD, 0x8, 0x0F, 7},
+{5, 0xE, 0x0, 0x0, 0x0, 0x19, 6},
+{5, 0xE, 0x1, 0x2, 0x2, 0x57, 7},
+{5, 0xE, 0x1, 0xA, 0x8, 0x01, 6},
+{5, 0xE, 0x1, 0xE, 0x4, 0x37, 7},
+{5, 0xF, 0x0, 0x0, 0x0, 0x1A, 5},
+{5, 0xF, 0x1, 0x9, 0x9, 0x17, 7},
+{5, 0xF, 0x1, 0xD, 0x5, 0x67, 7},
+{5, 0xF, 0x1, 0xF, 0x3, 0x07, 7},
+{5, 0xF, 0x1, 0xF, 0x1, 0x29, 6},
+{5, 0xF, 0x1, 0x7, 0x6, 0x27, 7},
+{5, 0xF, 0x1, 0xF, 0xC, 0x09, 6},
+{5, 0xF, 0x1, 0xF, 0x4, 0x31, 6},
+{5, 0xF, 0x1, 0xF, 0xA, 0x47, 7},
+{5, 0xF, 0x1, 0xF, 0x8, 0x11, 6},
+{5, 0xF, 0x1, 0xF, 0x2, 0x21, 6},
+{6, 0x0, 0x0, 0x0, 0x0, 0x00, 3},
+{6, 0x1, 0x0, 0x0, 0x0, 0x02, 4},
+{6, 0x1, 0x1, 0x1, 0x1, 0x03, 6},
+{6, 0x2, 0x0, 0x0, 0x0, 0x0C, 4},
+{6, 0x2, 0x1, 0x2, 0x2, 0x3D, 6},
+{6, 0x3, 0x0, 0x0, 0x0, 0x1D, 6},
+{6, 0x3, 0x1, 0x2, 0x2, 0x0D, 6},
+{6, 0x3, 0x1, 0x3, 0x1, 0x7F, 7},
+{6, 0x4, 0x0, 0x0, 0x0, 0x04, 4},
+{6, 0x4, 0x1, 0x4, 0x4, 0x2D, 6},
+{6, 0x5, 0x0, 0x0, 0x0, 0x0A, 5},
+{6, 0x5, 0x1, 0x4, 0x4, 0x35, 6},
+{6, 0x5, 0x1, 0x5, 0x1, 0x2F, 7},
+
+```
+
+---
+
+---
+
+```
+
+{6, 0x6, 0x0, 0x0, 0x0, 0x15, 6},
+{6, 0x6, 0x1, 0x2, 0x2, 0x3F, 7},
+{6, 0x6, 0x1, 0x6, 0x4, 0x5F, 7},
+{6, 0x7, 0x0, 0x0, 0x0, 0x25, 6},
+{6, 0x7, 0x1, 0x2, 0x2, 0x29, 6},
+{6, 0x7, 0x1, 0x3, 0x1, 0x1F, 7},
+{6, 0x7, 0x1, 0x7, 0x4, 0x6F, 7},
+{6, 0x8, 0x0, 0x0, 0x0, 0x16, 5},
+{6, 0x8, 0x1, 0x8, 0x8, 0x05, 6},
+{6, 0x9, 0x0, 0x0, 0x0, 0x39, 6},
+{6, 0x9, 0x1, 0x0, 0x0, 0x19, 6},
+{6, 0xA, 0x0, 0x0, 0x0, 0x06, 5},
+{6, 0xA, 0x1, 0xA, 0xA, 0x0F, 7},
+{6, 0xA, 0x1, 0xA, 0x2, 0x09, 6},
+{6, 0xA, 0x1, 0xA, 0x8, 0x4F, 7},
+{6, 0xB, 0x0, 0x0, 0x0, 0x0E, 6},
+{6, 0xB, 0x1, 0xB, 0x2, 0x77, 7},
+{6, 0xB, 0x1, 0x2, 0x2, 0x37, 7},
+{6, 0xB, 0x1, 0xA, 0x8, 0x57, 7},
+{6, 0xB, 0x1, 0xB, 0x1, 0x47, 7},
+{6, 0xC, 0x0, 0x0, 0x0, 0x1A, 5},
+{6, 0xC, 0x1, 0xC, 0xC, 0x17, 7},
+{6, 0xC, 0x1, 0xC, 0x8, 0x67, 7},
+{6, 0xC, 0x1, 0xC, 0x4, 0x27, 7},
+{6, 0xD, 0x0, 0x0, 0x0, 0x31, 6},
+{6, 0xD, 0x1, 0xD, 0x4, 0x07, 7},
+{6, 0xD, 0x1, 0x4, 0x4, 0x7B, 7},
+{6, 0xD, 0x1, 0xC, 0x8, 0x3B, 7},
+{6, 0xD, 0x1, 0xD, 0x1, 0x2B, 7},
+{6, 0xE, 0x0, 0x0, 0x0, 0x11, 6},
+{6, 0xE, 0x1, 0xE, 0x4, 0x5B, 7},
+{6, 0xE, 0x1, 0x4, 0x4, 0x1B, 7},
+{6, 0xE, 0x1, 0xE, 0xA, 0x6B, 7},
+{6, 0xE, 0x1, 0xE, 0x8, 0x21, 6},
+{6, 0xE, 0x1, 0xE, 0x2, 0x33, 7},
+{6, 0xF, 0x0, 0x0, 0x0, 0x01, 6},
+{6, 0xF, 0x1, 0x3, 0x3, 0x4B, 7},
+{6, 0xF, 0x1, 0x7, 0x6, 0x0B, 7},
+{6, 0xF, 0x1, 0xF, 0xA, 0x73, 7},
+{6, 0xF, 0x1, 0xF, 0x2, 0x3E, 6},
+{6, 0xF, 0x1, 0xB, 0x9, 0x53, 7},
+{6, 0xF, 0x1, 0xF, 0xC, 0x63, 7},
+
+```
+
+---
+
+---
+
+{6, 0xF, 0x1, 0xF, 0x8, 0x1E, 6},  
+{6, 0xF, 0x1, 0xF, 0x5, 0x13, 7},  
+{6, 0xF, 0x1, 0xF, 0x4, 0x2E, 6},  
+{6, 0xF, 0x1, 0xF, 0x1, 0x23, 7},  
+{7, 0x0, 0x0, 0x0, 0x0, 0x04, 4},  
+{7, 0x1, 0x0, 0x0, 0x0, 0x33, 6},  
+{7, 0x1, 0x1, 0x1, 0x1, 0x13, 6},  
+{7, 0x2, 0x0, 0x0, 0x0, 0x23, 6},  
+{7, 0x2, 0x1, 0x2, 0x2, 0x7F, 7},  
+{7, 0x3, 0x0, 0x0, 0x0, 0x03, 6},  
+{7, 0x3, 0x1, 0x1, 0x1, 0x3F, 7},  
+{7, 0x3, 0x1, 0x3, 0x2, 0x6F, 7},  
+{7, 0x4, 0x0, 0x0, 0x0, 0x2D, 6},  
+{7, 0x4, 0x1, 0x4, 0x4, 0x5F, 7},  
+{7, 0x5, 0x0, 0x0, 0x0, 0x16, 5},  
+{7, 0x5, 0x1, 0x1, 0x1, 0x3D, 6},  
+{7, 0x5, 0x1, 0x5, 0x4, 0x1F, 7},  
+{7, 0x6, 0x0, 0x0, 0x0, 0x1D, 6},  
+{7, 0x6, 0x1, 0x0, 0x0, 0x77, 7},  
+{7, 0x7, 0x0, 0x0, 0x0, 0x06, 5},  
+{7, 0x7, 0x1, 0x7, 0x4, 0x2F, 7},  
+{7, 0x7, 0x1, 0x4, 0x4, 0x4F, 7},  
+{7, 0x7, 0x1, 0x7, 0x3, 0x0F, 7},  
+{7, 0x7, 0x1, 0x7, 0x1, 0x0D, 6},  
+{7, 0x7, 0x1, 0x7, 0x2, 0x57, 7},  
+{7, 0x8, 0x0, 0x0, 0x0, 0x35, 6},  
+{7, 0x8, 0x1, 0x8, 0x8, 0x37, 7},  
+{7, 0x9, 0x0, 0x0, 0x0, 0x15, 6},  
+{7, 0x9, 0x1, 0x0, 0x0, 0x27, 7},  
+{7, 0xA, 0x0, 0x0, 0x0, 0x25, 6},  
+{7, 0xA, 0x1, 0x0, 0x0, 0x29, 6},  
+{7, 0xB, 0x0, 0x0, 0x0, 0x1A, 5},  
+{7, 0xB, 0x1, 0xB, 0x1, 0x17, 7},  
+{7, 0xB, 0x1, 0x1, 0x1, 0x67, 7},  
+{7, 0xB, 0x1, 0x3, 0x2, 0x05, 6},  
+{7, 0xB, 0x1, 0xB, 0x8, 0x7B, 7},  
+{7, 0xC, 0x0, 0x0, 0x0, 0x39, 6},  
+{7, 0xC, 0x1, 0x0, 0x0, 0x19, 6},  
+{7, 0xD, 0x0, 0x0, 0x0, 0x0C, 5},  
+{7, 0xD, 0x1, 0xD, 0x1, 0x47, 7},  
+{7, 0xD, 0x1, 0x1, 0x1, 0x07, 7},  
+{7, 0xD, 0x1, 0x5, 0x4, 0x09, 6},
+
+---
+
+---
+
+```
+{7, 0xD, 0x1, 0xD, 0x8, 0x1B, 7},
+{7, 0xE, 0x0, 0x0, 0x0, 0x31, 6},
+{7, 0xE, 0x1, 0xE, 0x2, 0x3B, 7},
+{7, 0xE, 0x1, 0x2, 0x2, 0x5B, 7},
+{7, 0xE, 0x1, 0xA, 0x8, 0x3E, 6},
+{7, 0xE, 0x1, 0xE, 0x4, 0x0B, 7},
+{7, 0xF, 0x0, 0x0, 0x0, 0x00, 3},
+{7, 0xF, 0x1, 0xF, 0xF, 0x6B, 7},
+{7, 0xF, 0x1, 0xF, 0x7, 0x2B, 7},
+{7, 0xF, 0x1, 0xF, 0xB, 0x4B, 7},
+{7, 0xF, 0x1, 0xF, 0x3, 0x11, 6},
+{7, 0xF, 0x1, 0x7, 0x6, 0x21, 6},
+{7, 0xF, 0x1, 0xF, 0xA, 0x01, 6},
+{7, 0xF, 0x1, 0xF, 0x2, 0x0A, 5},
+{7, 0xF, 0x1, 0xB, 0x9, 0x1E, 6},
+{7, 0xF, 0x1, 0xF, 0xC, 0x0E, 6},
+{7, 0xF, 0x1, 0xF, 0x8, 0x12, 5},
+{7, 0xF, 0x1, 0xF, 0x5, 0x2E, 6},
+{7, 0xF, 0x1, 0xF, 0x1, 0x02, 5},
+{7, 0xF, 0x1, 0xF, 0x4, 0x1C, 5}}
+```
+
+---
+
+# Annex D
+
+## JPH file format
+
+(This annex forms an integral part of this Recommendation | International Standard.)
+
+## D.1 General
+
+The JPH file format conforms to the JP2 file format specified in Rec. ITU-T T.800 | ISO/IEC 15444-1, unless specified otherwise in this annex.
+
+## D.2 JP2 Header box
+
+In contrast to the JP2 file format, if the `UnkC` field is non-zero it is not required that a Colour Specification box be present within the JP2 Header box.
+
+If the JP2 Header box does not contain a Colour Specification box:
+
+- the colourspace of the image data is unspecified; and
+- no `Typi` field shall be equal to 0.
+
+### D.3 File Type box
+
+The `BR` field shall be equal to `'jph\040'`.
+
+The `MinV` field shall be 0.
+
+One `CLi` field shall be equal to the value `'jph\040'`.
+
+## D.4 Colour Specification box
+
+#### D.4.1 Additional METH values
+
+This standard defines the METH values listed in Table D.1.
+
+Table D.1 – Additional METH values
+
+| Value | Meaning                                                                                                                                                                                                                                                                                                                          |
+|-------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| 0-2   | As specified in Rec. ITU-T T.800   ISO/IEC 15444-1.                                                                                                                                                                                                                                                                              |
+| 3     | Any International Color Consortium (ICC) method. This Colour Specification box indicates that the colourspace of the codestream is specified by an embedded input ICC profile. Contrary to the Restricted ICC method defined in the JP2 file format, this method allows for any input ICC profile, described in ISO/IEC 15076-1. |
+| 5     | Parameterized colourspace as specified in Rec. ITU-T H.273   ISO/IEC 23001-8                                                                                                                                                                                                                                                     |
+
+#### D.4.2 Any International Color Consortium method
+
+When the METH field is equal to 3, the Colour Specification box shall be organized as specified in Figure D.1 and Table D.2.
+
+![Diagram showing the organization of the contents of a Colour Specification box when METH = 3. It consists of four adjacent rectangular boxes labeled METH, PREC, APPROX, and PROFILE.](e64b41a22015ac3a9c17115aabd51e53_img.jpg)
+
+|      |      |        |         |
+|------|------|--------|---------|
+| METH | PREC | APPROX | PROFILE |
+|------|------|--------|---------|
+
+Diagram showing the organization of the contents of a Colour Specification box when METH = 3. It consists of four adjacent rectangular boxes labeled METH, PREC, APPROX, and PROFILE.
+
+T.814(19)\_FD.1
+
+Figure D.1 – Organization of the contents of a Colour Specification box when METH = 3
+
+**Table D.2 – Format of the contents of the Colour Specification box**
+
+| Field name | Size (bits) | Value                                                                                                                                                                                                                    |
+|------------|-------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| PROFILE    | Variable    | ICC input profile as defined by ISO/IEC 15076-1, specifying the transformation between the decompressed code values and the PCS. Any input ICC profile, regardless of profile class, may be contained within this field. |
+
+NOTE – This method is equivalent to the Any ICC method specified in Rec. ITU-T T.801 | ISO/IEC 15444-2.
+
+#### D.4.3 Parameterized colourspace
+
+When the METH field is equal to 5, the Colour Specification box shall be organized as specified in Table D.3 and Figure D.2.
+
+![Figure D.2: Organization of the contents of a Colour Specification box when METH = 5. The diagram shows a vertical stack of eight fields: METH, PREC, APPROX, COLPRIMS, TRANSFC, MATCOEFFS, VIDFRNG, and VIDFRNG_RSVD.](e05434e963901d7e9c0bf5a6758200ed_img.jpg)
+
+|      |      |        |          |         |           |         |              |
+|------|------|--------|----------|---------|-----------|---------|--------------|
+| METH | PREC | APPROX | COLPRIMS | TRANSFC | MATCOEFFS | VIDFRNG | VIDFRNG_RSVD |
+|------|------|--------|----------|---------|-----------|---------|--------------|
+
+Figure D.2: Organization of the contents of a Colour Specification box when METH = 5. The diagram shows a vertical stack of eight fields: METH, PREC, APPROX, COLPRIMS, TRANSFC, MATCOEFFS, VIDFRNG, and VIDFRNG\_RSVD.
+
+T.814(19)\_FD.2
+
+**Figure D.2 – Organization of the contents of a Colour Specification box when METH = 5****Table D.3 – Format of the contents of the Colour Specification box**
+
+| Field name   | Size (bits) | Value                                                                                                |
+|--------------|-------------|------------------------------------------------------------------------------------------------------|
+| COLPRIMS     | 16          | One of the ColourPrimaries enumerated values specified in Rec. ITU-T H.273   ISO/IEC 23001-8         |
+| TRANSFC      | 16          | One of the TransferCharacteristics enumerated values specified in Rec. ITU-T H.273   ISO/IEC 23001-8 |
+| MATCOEFFS    | 16          | One of the MatrixCoefficients enumerated values specified in Rec. ITU-T H.273   ISO/IEC 23001-8      |
+| VIDFRNG      | 1           | Value of the VideoFullRangeFlag specified in Rec. ITU-T H.273   ISO/IEC 23001-8                      |
+| VIDFRNG_RSVD | 7           | Reserved for future use by ITU-T   ISO/IEC                                                           |
+
+### D.5 Contiguous codestream box
+
+The Contiguous Codestream box shall contain a valid and complete HTJ2K codestream as specified in clause 6.1.
+
+NOTE – Rec. ITU-T T.800 | ISO/IEC 15444-1 specifies that, when displaying the image, all codestreams after the first codestream found in the file are ignored, and that Contiguous Codestream boxes can be found anywhere in the file except before the JP2 Header box.
+
+### D.6 Channel Definition box
+
+#### D.6.1 Single alpha channel
+
+In contrast to the JP2 file format, which supports multiple alpha channels, JPH only supports a single alpha channel.
+
+If the Channel Definition box is present, at most one Typ<sup>i</sup> field shall be equal to 1 or 2, and the corresponding Asoc<sup>i</sup> field shall be equal to 0.
+
+#### D.6.2 Multiple channels per colour
+
+In contrast to the JP2 file format, multiple channels can be associated with the same colour.
+
+There may be more than one channel with the same Typ<sup>i</sup> and Asoc<sup>i</sup> value pair.
+
+EXAMPLE – Multiple channels of the same colour in a Bayer pattern can be described using the same Typ<sup>i</sup> and Asoc<sup>i</sup> value pair, and but different component registration position, as carried in the optional CRG marker segment.
+
+#### **D.6.3 Application-specified colour**
+
+This standard defines the additional Typ<sup>i</sup> values listed in Table D.4.
+
+**Table D.4 – Additional Typ<sup>i</sup> field value**
+
+| Value | Meaning                                                         |
+|-------|-----------------------------------------------------------------|
+| 3     | The colour associated with this channel is application-defined. |
+
+When Typ<sup>i</sup> is equal to 3, the value of Asoc<sup>i</sup> shall be between 0 and 2<sup>16</sup> -1 and is application-defined.
+
+Asoc<sup>i</sup> values are application-specific.
+
+# Annex E
+
+## Media type specifications and registrations
+
+(This annex forms an integral part of this Recommendation | International Standard.)
+
+## E.1 General
+
+Many Internet protocols are designed to carry arbitrary labelled content. The mechanism used to label such content is a media type, which is defined in IETF RFC 6838 and consists of a top-level type, a subtype, and in some instances, optional parameters.
+
+The media type specifications of clauses E.2 and E.3 have a matching registration in the Internet Assigned Numbers Authority central registry, as specified in IETF RFC 6838.
+
+## E.2 JPH file
+
+#### E.2.1 General
+
+The image/jph media type refers to content that consists of a single JPH file as specified in Annex D.
+
+### E.2.2 Registration
+
+---
+
+```
+
+Type name: image
+Subtype name: jph
+Required parameters: N/A
+Optional parameters: N/A
+Encoding considerations: See Section 4.1 of RFC 3745.
+Security considerations: See Section 3 of RFC 3745.
+Interoperability considerations: N/A
+Published specification: Rec. ITU-T T.814 | ISO/IEC 15444-15
+Applications: Multimedia and scientific
+Fragment identifier considerations: N/A
+Restrictions on usage: N/A
+Additional information:
+    Deprecated alias names for this type: N/A
+    Magic number(s): See Section 4.4 of RFC 3745
+    File extension(s): jph
+    Macintosh File Type Code(s): N/A
+Object Identifiers: N/A
+Contact name: ISO/IEC JTC 1/SC 29/WG 1 Convenor
+Contact email address: sc29-sec@itscj.ipsj.or.jp
+Intended usage: COMMON
+Change controller: ITU-T & ISO/IEC JTC 1
+
+```
+
+---
+
+## E.3 Single HTJ2K codestream
+
+#### E.3.1 General
+
+The image/jphc media type refers to content that consists of a single HTJ2K codestream, as specified in clause 6.1.
+
+#### E.3.2 Registration ---
+
+Type name: image
+
+Subtype name: jphc
+
+Required parameters: N/A
+
+Optional parameters: N/A
+
+Encoding considerations: binary
+
+Security considerations: HTJ2K codestreams contain structures of variable length and have an extensible syntax. Both of these aspects present potential security risks for implementations. In particular, variable length structures present buffer overflow risks and extensible syntax could result in the triggering of adverse actions.
+
+Interoperability considerations: HTJ2K codestreams do not contain information on the colourspace of the image. This information is implied or provided out-of-band.
+
+Published specification: Rec. ITU-T T.814 | ISO/IEC 15444-15
+
+Applications: Multimedia and scientific
+
+Fragment identifier considerations: N/A
+
+Restrictions on usage: N/A
+
+Additional information:
+
+    Magic number(s): Starts with the following 4-byte sequence: 0xFF 0x4F 0xFF 0x51
+
+    File extension(s): jhc
+
+    Macintosh File Type Code(s): N/A
+
+    Object Identifiers: N/A
+
+Contact name: ISO/IEC JTC 1/SC 29/WG 1 Convenor
+
+Contact email address: sc29-sec@itscj.ipsj.or.jp
+
+Intended usage: COMMON
+
+Change controller: ITU-T & ISO/IEC JTC 1
+
+---
+
+# Annex F
+
+## HT block encoding procedures
+
+(This annex does not form an integral part of this Recommendation | International Standard.)
+
+## F.1 Overview
+
+An HT block encoder can produce multiple sets of HT cleanup, SigProp and MagRef coding passes, selecting some or all of these to be included in the generated codestream; it can also generate partial sets of coding passes, or no coding passes at all, for a given code-block. For most applications, at most three coding passes are included in the codestream for each code-block, belonging to one HT set. Rate control strategies, including those that employ post-compression rate-distortion optimization principals, can be employed to determine which coding passes are included within the codestream. Moreover, rate and complexity control strategies can be employed to determine which coding passes are produced by an encoder, from which to select the passes that are included in the codestream.
+
+When transcoding content from a codestream whose code-blocks were encoded according to the algorithm defined in Rec. ITU-T T.800 | ISO/IEC 15444-1, it is sufficient to encode at most one HT cleanup, HT SigProp and HT MagRef coding pass for each code-block, corresponding to the final cleanup pass and any subsequent SigProp and MagRef passes from the original coded representation of that code-block. Specifically, such an approach is sufficient to exactly preserve all quantized sample values from the original codestream. Beyond this, it can be desirable to preserve the code-block truncation points associated with multiple quality layers in the original codestream. This can be done by including "placeholder passes," as explained in Annex B.
+
+Beyond the use of placeholder passes, an encoder can choose to generate and include multiple HT sets for any given code-block, as explained in Annex B; this mechanism can be used to provide representations of a code-block at multiple precisions, which can be selectively extracted from quality layers. An encoder can also choose to include multiple HT cleanup passes without generating or including any intervening HT SigProp or MagRef code bytes, since the HT SigProp and MagRef coding passes that are associated with a zero length HT refinement segment are not processed by the decoder; in such cases `Z_blk` is 1.
+
+In applications where encoded quality (or compressed size) are driven entirely by quantization parameter selection – the most common rate control paradigm employed by image and video codecs, – it is sufficient for the HT block encoder to produce only one HT cleanup pass for each code-block, yielding a representation that has no quality scalability attributes, but retains all other features from the Rec. ITU-T T.800 | ISO/IEC 15444-1 family of standards.
+
+The most substantial element of the HT block-coding algorithm is the HT cleanup pass, since the other passes are derived with only minor modifications from the HT SigProp and HT MagRef passes defined in Rec. ITU-T T.800 | ISO/IEC 15444-1, operating in the arithmetic coder bypass mode. The main purpose of this annex is to provide an overview of the HT cleanup pass coding algorithm from the perspective of an encoder, whereas the main body of this Specification is concerned with a normative description of the decoding process. To facilitate the description, Figure F.1 provides a block diagram of the HT cleanup encoding process. This can be compared with Figure 3, which provides a corresponding block diagram for the HT cleanup decoding process.
+
+![Figure F.1 – HT cleanup pass encoder overview. This block diagram illustrates the processing flow for the HT cleanup pass. It starts with a storage block M1 (green) providing inputs D1 through D5. D1 goes to block B1 (AZC), which outputs c_q to B2. B2 also receives s_{q1,q2}^{mel} and N1, and outputs rho_q = 0? to B3. D2 goes to B3. B3 outputs epsilon_q^k to B4 and B7. B4 (compute magnitude exponent bound) receives D3 and outputs U_q to B7 and epsilon_q-bar to B5. B5 (form exponent predictors) receives D4 and kappa_q from B4, and outputs gamma_q to B6. B6 (compute gamma_q) outputs rho_q to B7. B7 (compute MagSgn bit counts) receives U_q, epsilon_q-bar, and rho_q, and outputs m_n to B9. B9 (pack MagSgn LSBs) receives D5 and v_n, and outputs C2 to B10. B10 (bit-stuffing) outputs C2 to B13. B11 (bit-stuffing) receives C3 and outputs to B13. B12 (bit-stuffing) receives C4 and outputs to B13. B13 (combine byte-streams) outputs C1. B8 (encode unsigned residuals) receives u_q and outputs to S1. S1 (interleave quad-pair VLC bits) receives N1 and outputs to B2. The diagram is labeled T.814(19)_FF.1.](e0627c8e3dfda5da1ee8d5a90c9f7489_img.jpg)
+
+Figure F.1 – HT cleanup pass encoder overview. This block diagram illustrates the processing flow for the HT cleanup pass. It starts with a storage block M1 (green) providing inputs D1 through D5. D1 goes to block B1 (AZC), which outputs c\_q to B2. B2 also receives s\_{q1,q2}^{mel} and N1, and outputs rho\_q = 0? to B3. D2 goes to B3. B3 outputs epsilon\_q^k to B4 and B7. B4 (compute magnitude exponent bound) receives D3 and outputs U\_q to B7 and epsilon\_q-bar to B5. B5 (form exponent predictors) receives D4 and kappa\_q from B4, and outputs gamma\_q to B6. B6 (compute gamma\_q) outputs rho\_q to B7. B7 (compute MagSgn bit counts) receives U\_q, epsilon\_q-bar, and rho\_q, and outputs m\_n to B9. B9 (pack MagSgn LSBs) receives D5 and v\_n, and outputs C2 to B10. B10 (bit-stuffing) outputs C2 to B13. B11 (bit-stuffing) receives C3 and outputs to B13. B12 (bit-stuffing) receives C4 and outputs to B13. B13 (combine byte-streams) outputs C1. B8 (encode unsigned residuals) receives u\_q and outputs to S1. S1 (interleave quad-pair VLC bits) receives N1 and outputs to B2. The diagram is labeled T.814(19)\_FF.1.
+
+- B1: Compute contexts.  
+B2: Encode MEL symbols.  
+B3: Encode CxtVLC codewords.  
+B4: Compute magnitude exponent bound  $U_q$ , residual  $u_q$  and EMB pattern  $\bar{\epsilon}_q$ .  
+B5: Form exponent predictors.  
+B6: Compute  $\gamma_q$  from  $\rho_q$ .  
+B7: Compute MagSgn bit counts  $m_n$ .  
+B8: Encode unsigned residuals  $u_q$  to U-VLC codewords.  
+B9: Pack  $m_n$  MagSgn LSBs from each location  $n$ .  
+B10: Bit-stuffing to produce MagSgn byte-stream from MagSgn bit-stream.  
+B11: Bit-stuffing to produce MEL byte-stream from MEL bit-stream.  
+B12: Bit-stuffing to produce VLC byte-stream from VLC bit-stream.  
+B13: Combine byte-streams to produce HT cleanup segment.  
+C1: Generated HT cleanup segment.  
+C2: Generated MagSgn bit-stream.  
+C3: Generated MEL bit-stream.  
+C4: Generated VLC bit-stream.  
+D1: Retrieved neighbouring significance patterns.  
+D2: Retrieved significance patterns.  
+D3: Retrieved magnitude exponents.  
+D4: Retrieved neighbouring magnitude exponents.  
+D5: Retrieved MagSgn values.  
+M1: Storage for code-block significance, exponents and MagSgn values.  
+N1: First line-pair of code-block only.  
+S1: Interleave quad-pair VLC bits.
+
+**Figure F.1 – HT cleanup pass encoder overview**
+
+Some features of the coding algorithm are summarized in the following. These features can be readily identified within the encoding and decoding block diagrams of Figure F.1 and Figure 3.
+
+- Sub-band samples within a code-block are processed in 2x2 quads  $q$ , each of which is assigned a 4-bit significance pattern  $\rho_q$  that indicates the significance of each sample in the quad.
+- Significance patterns are coded using a combination of two different techniques: an adaptive run-length code (MEL code) and a set of non-adaptive VLC codes (CxtVLC codes).
+- Exponent bounds  $U_q$  are coded via "unsigned prediction residuals"  $u_q$  on a quad-by-quad basis.
+
+- The predictors  $\kappa_n$  are derived from magnitude exponents of certain previously coded samples, which themselves depend upon the MagSgn values of earlier samples in the code-block.
+- The significance pattern  $\rho_q$  and unsigned prediction residuals  $u_q$  for a quad are coded jointly, using a VLC coding scheme that involves two sub-codes, one of which (CxtVLC code) is dependent on a neighbourhood significance context  $c_q$  and best suited to table-lookup approaches, while the other (U-VLC code) is amenable to direct computation if required.
+- The VLC code bits for pairs of 2x2 quads are interleaved in a manner that facilitates joint encoding or decoding of 8 samples at a time, while allowing 4-sample quads to be encoded or decoded individually if desired.
+- The CxtVLC also encodes a variable amount of additional information about the magnitude exponents of each sample in the quad. This information, known as EMB pattern information, is combined with the exponent bound  $U_q$  and significance pattern  $\rho_q$  to determine the number of sign and least significant magnitude bits from each sample of each quad that are packed into a MagSgn bit stream.
+
+An important property of the HT cleanup pass is that it involves three byte-streams that grow in different directions. Three separate bit-streams (MEL, VLC and MagSgn) are subjected to bit-stuffing and packed into the corresponding three byte-streams in a way that avoids the appearance of false marker codes in the range  $0 \times \text{FF}90$  to  $0 \times \text{FFFF}$ . Care is required to combine the byte-streams into the single HT cleanup segment in such a way that it is free from false marker codes and does not terminate with a byte equal to  $0 \times \text{FF}$ , which are fundamental requirements for all codeword segments that conform to Rec. ITU-T T.800 | ISO/IEC 15444-1. The adoption of separate bit-streams provides considerable flexibility that can be exploited by implementations of the algorithm, to minimize memory, maximize concurrency, or fully utilize vector processing capabilities of a particular architecture.
+
+Clauses F.2 to F.4 provide first an overview of the relevant quantities and relationships for an encoder, then a description of the encoding steps, and finally a discussion of bit-stuffing, termination and byte-stream concatenation operations to produce valid HT segments.
+
+## F.2 Bit-planes, exponents, MagSgn and EMB patterns
+
+Each HT cleanup pass is associated with a particular bit-plane  $p$ , wherein the magnitude of sample  $X_n$  is taken to be
+
+$$\mu_{p,n} = \left\lfloor \frac{|X_n|}{2^p \Delta_n} \right\rfloor$$
+
+and the sample is considered *significant* if  $\mu_{p,n} \neq 0$ . Here  $\Delta_n$  is the quantization step size that applies to the sub-band to which the code-block belongs, possibly modified to account for an encoded region-of-interest. In the latter case, samples belonging to the region of interest use a quantization step size that is smaller than the nominal value for the sub-band by a factor of  $2^{\text{SPrgn}}$ , where SPrgn is recorded within the RGN marker segment.
+
+The sample's *magnitude exponent*  $E_{p,n}$  is given by
+
+$$E_{p,n} = \min \left\{ E \in \mathbb{N} \mid \mu_{p,n} - \frac{1}{2} < 2^{E-1} \right\} \quad (\text{F.1})$$
+
+An encoder can compute all such exponents in advance of the other coding steps, by counting (scanning) the number of leading zeros in a binary representation of  $2\mu_{p,n} - 1$ . Moreover, it is possible to efficiently compute exponents for multiple bit-planes  $p$  at once, if desired.
+
+A sample is significant if and only if its magnitude exponent is non-zero. The HT cleanup pass algorithm explicitly codes significance information, after which it is only necessary to code the sign  $s_n$  and the value of  $\mu_{p,n} - 1$  for each significant sample. This information is combined within "MagSgn" values
+
+$$v_{p,n} = s_n + 2(\mu_{p,n} - 1) < 2^{E_{p,n}}$$
+
+For the remainder of this annex, the bit-plane specific sub-script  $p$  is dropped, to simplify notation.
+
+For each quad  $q$  that contains at least one significant sample, an upper bound on the magnitude exponents within that quad is identified as  $U_q$ . These bounds are encoded via corresponding unsigned residuals  $u_q$ , with respect to exponent predictors  $\kappa_q$ , so that
+
+$$U_q = u_q + \kappa_q \geq E_n \text{ for all } n \in \{4q, 4q + 1, 4q + 2, 4q + 3\}$$
+
+This bound is required to be tight if  $u_q > 0$ , which implies that
+
+$$U_q = \max\{E_q^{\max}, \kappa_q\}, \quad (\text{F.2})$$
+
+where
+
+$$E_q^{\max} = \max\{E_{4q}, E_{4q+1}, E_{4q+2}, E_{4q+3}\}. \quad (\text{F.3})$$
+
+$E_q^{\max}$  and  $U_q$  are equal when  $u_q > 0$ , which corresponds to the condition that the unsigned residual offset bit  $u_q^{\text{off}} = 1$ .
+
+The complete 4-bit EMB pattern for quad  $q$ , denoted  $\bar{\epsilon}_q$ , identifies those samples within the quad whose magnitude exponent is equal to  $E_q^{\max}$ , and hence also equal to  $U_q$ , when  $u_q > 0$ . Specifically,
+
+$$\bar{\epsilon}_q = \epsilon_{4q} + 2\epsilon_{4q+1} + 4\epsilon_{4q+2} + 8\epsilon_{4q+3} \quad (\text{F.4})$$
+
+where the binary EMB flags  $\epsilon_n$  are defined by
+
+$$\epsilon_n = \begin{cases} u_q^{\text{off}} & \text{if } E_n = E_q^{\max} \\ 0 & \text{otherwise} \end{cases}, \text{ for all } n \in \{4q, 4q+1, 4q+2, 4q+3\} \quad (\text{F.5})$$
+
+The complete EMB pattern  $\bar{\epsilon}_q = 0$  if  $u_q^{\text{off}} = 0$ . Moreover, if  $u_q^{\text{off}} = 1$ ,  $\bar{\epsilon}_q$  must be non-zero, since at least one of the quad's samples must have exponent  $E_n$  equal to the quad's maximum exponent  $E_q^{\max}$ . It follows that the value of the  $u_q^{\text{off}}$  flag is implied by  $\bar{\epsilon}_q$ , which is valuable in reducing the size of lookup tables used by the encoder's CxtVLC encoding process, as described in the following.
+
+While the encoder can form the complete EMB pattern  $\bar{\epsilon}_q$  directly, the decoder recovers only a subset of the EMB pattern information via the CxtVLC decoding process described in clause 7.3.5. In particular, the bits of the complete EMB pattern  $\bar{\epsilon}_q$  that are recovered by the decoder are identified by the EMB *known-bit* pattern  $\bar{\epsilon}_q^k$ , whose binary digits are denoted  $k_n$ , as explained in clause 7.3.2. The encoder deduces the *known-bit* pattern  $\bar{\epsilon}_q^k$  from the complete EMB pattern  $\bar{\epsilon}_q$  during the CxtVLC encoding process, using this to determine the number of bits to be packed to the MagSgn bit-stream.
+
+## F.3 Cleanup pass encoding steps
+
+This clause provides a description of the individual encoding steps that are found in the block diagram of Figure F.1. The reader is reminded that this description is informative only; various encoder implementations may achieve the same behaviour using different steps, or applying these steps in a different order, potentially using less memory, computation or other resources.
+
+As a first step, the encoder converts sample magnitude values  $\mu_n$  to magnitude exponents  $E_n$ , following Formula (F.1). At the same time, the significance pattern  $\rho_q$  is determined for each quad  $q$ , along with the derivative quantity  $\gamma_q \in \{0,1\}$  that indicates whether or not quad  $q$  has more than one significant sample, following Formula (6).
+
+For the first row of quads in a code-block, the exponent predictors are set to  $\kappa_q = 1$ , while for all other quads, predictors are set according to Formula (5).
+
+The encoder forms maximum magnitude exponents  $E_q^{\max}$  for each quad  $q$ , according to Formula (F.3) then exponent bounds  $U_q$  according to Formula (F.2). From these, the unsigned exponent residuals are found using
+
+$$u_q = U_q - \kappa_q$$
+
+and the unsigned residual offset flags  $u_q^{\text{off}} \in \{0,1\}$  are found from
+
+$$u_q^{\text{off}} = \begin{cases} 0 & \text{if } u_q = 0 \\ 1 & \text{if } u_q > 0 \end{cases}$$
+
+The encoder can then evaluate the full EMB pattern  $\bar{\epsilon}_q$  for each quad  $q$ , using Formula (F.4) and Formula (F.5).
+
+Context labels  $c_q$  are formed using Formula (1) for the first row of quads in a code-block and Formula (2) for all other quads in the code-block.
+
+The CxtVLC encoding process is readily achieved using a table lookup approach, with 11 bit indices formed from
+
+$$n_q = \bar{\epsilon}_q + 16 \cdot \rho_q + 256 \cdot c_q$$
+
+and table entries containing the triplet  $(w, l_w, \bar{\epsilon}_q^k)$ , where  $w$  is the VLC codeword,  $l_w$  the codeword length, and  $\bar{\epsilon}_q^k$  the EMB *known-bit* pattern that will be recovered by the decoder. All valid CxtVLC codewords have lengths in the range 1 to 7, but it is convenient to assign empty codewords ( $l_w = 0$ ) to all other entries. In particular, this means that the case  $\rho_q = c_q = 0$ , corresponding to an insignificant AZC quad, does not need to be treated specially, since the CxtVLC coding of this case will not emit any bits to the CxtVLC bit-stream.
+
+Each bit in the  $\bar{\epsilon}_q$  pattern can be 1 only if the corresponding bit in  $\rho_q$  is 1, so the lookup table indexed by  $n_q$  consists mostly of invalid entries that will not be accessed. Thus, more compact representations are possible.
+
+Separate CxtVLC encoding tables are required for each quad-type: one for the first row of quads in a code-block; and one for all other quads. These encoding tables can be derived from the CxtVLC 7-tuples  $(c_q, \rho_q, u_q^{\text{off}}, \bar{\epsilon}_q^k, \bar{\epsilon}_q^1, w, l_w)$  tabulated in Annex C. In particular, for a given lookup index  $n_q$ , the encoding table's triplet  $(w, l_w, \bar{\epsilon}_q^k)$ , can be derived by copying the data from any matching 7-tuple  $(c_q, \rho_q, u_q^{\text{off}}, \bar{\epsilon}_q^k, \bar{\epsilon}_q^1, w, l_w)$ . A match occurs whenever the following conditions are met:
+
+$$c_q = \left\lfloor \frac{n_q}{256} \right\rfloor, \rho_q = \text{mod} \left( \frac{n_q}{16}, 16 \right), \bar{\epsilon}_q^1 = \text{mod}(n_q, 16) \& \bar{\epsilon}_q^k$$
+
+In the in the foregoing,  $A \& B$  indicates the logical AND of the two 4-bit quantities  $A$  and  $B$ .
+
+NOTE 1 – There can in general be multiple matching 7-tuples, and hence multiple valid codewords that an encoder can elect to use. For maximum coding efficiency, the encoder bases its encoding table on the matching 7-tuple whose EMB *known-bit* pattern  $\bar{\epsilon}_q^k$  has the most set bits.
+
+The encoder combines the  $\bar{\epsilon}_q^k$  pattern produced by its CxtVLC table lookup with the computed magnitude exponent bound  $U_q$  and significance pattern  $\rho_q$  to determine the number of MagSgn bits  $m_n$  that need to be emitted for each sample. Specifically, the encoder forms
+
+$$m_n = \sigma_n \cdot U_q - k_n,$$
+
+noting that  $\sigma_n$  and  $k_n$  are the individual bits within the 4-bit patterns  $\rho_q$  and  $\bar{\epsilon}_q^k$ .
+
+The encoder generates the MagSgn bit-stream by passing the bit-count  $m_n$  and MagSgn value  $v_n$  to the `emitMagSgnBits` procedure defined in clause F.4, for each sample in turn, following the quad-based scanning order of Figure 2. The `emitMagSgnBits` procedure emits the  $m_n$  LSBs of  $v_n$  to the MagSgn bit-stream.
+
+The MEL bit-stream is formed by applying the `encodeMEL` procedure in the following to a sequence of binary MEL symbols  $s_q^{\text{mel}}$  and binary mask values  $m_q^{\text{mel}}$ , where  $m_q^{\text{mel}}$  indicates whether symbol  $s_q^{\text{mel}}$  is to be coded. For non-initial quad rows, and for the first quad in each quad-pair within the first row of quads for the code-block, these values are set according to
+
+$$m_q^{\text{mel}} = \begin{cases} 1 & \text{if } c_q = 0 \\ 0 & \text{if } c_q \neq 0 \end{cases} \quad \text{and} \quad s_q^{\text{mel}} = \begin{cases} 1 & \text{if } c_q = 0 \text{ and } \rho_q \neq 0 \\ 0 & \text{otherwise} \end{cases}$$
+
+For the second quad  $q_2$  in a quad-pair  $(q_1, q_2)$  within the first row of quads in the code-block, the  $m_{q_2}^{\text{mel}}$  and  $s_{q_2}^{\text{mel}}$  values are set using
+
+$$m_{q_2}^{\text{mel}} = \begin{cases} 1 & \text{if } c_q = 0 \\ m_{q_1, q_2}^{\text{mel}} & \text{if } c_q \neq 0 \end{cases} \quad \text{and} \quad s_{q_2}^{\text{mel}} = \begin{cases} 1 & \text{if } c_q = 0 \text{ and } \rho_q \neq 0 \\ s_{q_1, q_2}^{\text{mel}} & \text{otherwise} \end{cases}$$
+
+where
+
+$$m_{q_1, q_2}^{\text{mel}} = u_{q_1}^{\text{off}} \cdot u_{q_2}^{\text{off}} \quad \text{and} \quad s_{q_1, q_2}^{\text{mel}} = \begin{cases} 1 & \text{if } \min\{u_{q_1}, u_{q_2}\} > 2 \\ 0 & \text{otherwise} \end{cases}$$
+
+Before encoding anything for a code-block, the MEL encoding state is initialized using the `initMELEncoder` procedure in the following, after which the `encodeMEL` procedure can be called with the symbol and mask values explained in the foregoing. The MEL\_E exponent table used by these procedures is found in Table 2.
+
+---
+
+```
+
+Procedure: initMELEncoder
+State: MEL_k, MEL_run, MEL_t
+
+```
+
+```
+
+MEL_k                                     =                                0
+MEL_run = 0
+MEL_t = 1 << MEL_E[MEL_k]
+
+```
+
+---
+
+---
+
+ Procedure: encodeMEL
+
+ Inputs: symbol  $s_q^{\text{mel}} \in \{0,1\}$  and mask  $m_q^{\text{mel}} \in \{0,1\}$ 
+
+State: MEL\_k, MEL\_run, MEL\_t
+
+```
+
+if ( $m_q^{\text{mel}} == 1$ )
+    if ( $s_q^{\text{mel}} == 0$ )
+        MEL_run = MEL_run + 1
+        if (MEL_run >= MEL_t)
+            emitMELBit(1)
+            MEL_run = 0
+            MEL_k = min(12, MEL_k+1)
+            eval = MEL_E[MEL_k]
+            MEL_t = 1 << eval
+        else
+            emitMELBit(0)
+            eval = MEL_E[MEL_k]
+            while (eval > 0)
+                eval = eval - 1
+                msb = (MEL_run >> eval) & 1
+                emitMELBit(msb)
+            MEL_run = 0
+            MEL_k = max(0, MEL_k-1)
+            eval = MEL_E[MEL_k]
+            MEL_t = 1 << eval
+
+```
+
+---
+
+Once all MEL symbols have been encoded, the termMEL procedure is called.
+
+---
+
+ Procedure:
+
+termMEL
+
+State: MEL\_k, MEL\_run, MEL\_t
+
+```
+
+if (MEL_run > 0)
+    emitMELBit(1)
+
+```
+
+---
+
+NOTE 2 – The emitMELBit procedure is defined in clause F.4.
+
+The encoder generates the VLC bit-stream by packing CxtVLC codewords and U-VLC codeword components (prefix, suffix and extension) from quad-pairs, following the interleaving procedure shown in Figure 4, and passing all codeword bits to the emitVLCBits procedure defined in clause F.4.
+
+In the first row of quads for a code-block, if a quad-pair has  $m_{q_1,q_2}^{\text{mel}} = 1$  and  $s_{q_1,q_2}^{\text{mel}} = 1$ , the U-VLC codeword prefix, suffix and extension components for both quads in the pair are obtained by passing  $u_{q_1} - 2$  and  $u_{q_2} - 2$  as the u\_in input to the encodeUVLC procedure in the following. In all other cases, the U-VLC codeword components for a quad are obtained by passing  $u_q$  directly as the u\_in input to encodeUVLC, except where a quad-pair  $(q_1, q_2)$  in the first row of quads has  $m_{q_1,q_2}^{\text{mel}} = 1$ ,  $s_{q_1,q_2}^{\text{mel}} = 0$  and  $u_{q_1} > 2$ . In this last case, it is certain that  $u_{q_2} \in \{1,2\}$  and the U-VLC components for quad  $q_2$  are assigned as u\_pfx =  $u_{q_2} - 1$ , u\_sfx = 0 and u\_ext = 0.
+
+---
+
+Procedure: `encodeUVLC`
+
+Input: `u_in`
+
+Returns: `u_pfx`, `u_sfx` and `u_ext`
+
+```
+
+if (u_in == 0)
+    set u_pfx, u_sfx and u_ext all to empty codewords (no bits)
+else
+    find u_pfx, u_sfx and u_ext from the entry in Table 3 for which  $u = u\_in$ 
+
+```
+
+---
+
+## F.4 Bit-stuffing and byte-stream termination procedures
+
+The HT cleanup pass encoding steps produce bits for the MEL, VLC and MagSgn bit-streams of the cleanup pass, which are packed into corresponding byte-streams and then assembled into an HT cleanup segment. HT SigProp and MagRef coding passes, where used, produce bits for a SigProp or a MagRef bit-stream, which are packed into corresponding byte-streams and assembled into an HT refinement segment. All bit packing operations are subjected to bit stuffing procedures that avoid the appearance of false marker codes within any given byte-stream. While the decoder only needs to read bytes from already constructed HT segments, the encoder is responsible for combining byte-streams into final HT segments, noting that some byte-streams grow forwards while others grow backwards. This would typically be done at the end, once all component byte-streams for a code-block have been generated. During this process, the encoder is responsible for terminating the byte-streams in such a way as to avoid the introduction of false marker codes at byte-stream interfaces, while ensuring correct decoding. This clause provides procedures that can be used for these purposes.
+
+To generate the MagSgn byte-stream, an encoder can use the `emitMagSgnBits` procedure in the following, after initializing state variables with the `initMSPacker` procedure. The `emitMagSgnBits` procedure assumes the existence of a buffer (array) denoted `MS_buf`, with sufficient length to accommodate all generated MagSgn bytes for the code-block. The maximum number of such bytes can be bounded, based on the precision of quantized sub-band samples, but the determination of such bounds is beyond the scope of this discussion. Once all MagSgn bits have been emitted for a code-block, the MagSgn byte-stream is terminated by invoking the `termMSPacker` procedure.
+
+---
+
+Procedure: `initMSPacker`
+
+State: `MS_pos`, `MS_bits`, `MS_max`, `MS_tmp`
+
+```
+
+MS_pos = 0
+MS_bits = 0
+
+MS_max = 8
+MS_tmp = 0
+
+```
+
+---
+
+---
+
+```
+Procedure: emitMagSgnBits
+```
+
+```
+Input: val =  $v_n$  and len =  $m_n$ 
+```
+
+```
+State: MS_pos, MS_bits, MS_max, MS_tmp
+```
+
+```
+while (len > 0)
+    bit = val & 1
+    val = val >> 1
+    len = len - 1
+    MS_tmp = MS_tmp | (bit << MS_bits)
+    MS_bits = MS_bits + 1
+    if (MS_bits == MS_max)
+        MS_buf[MS_pos] = MS_tmp
+        MS_pos = MS_pos + 1
+        MS_max = (MS_tmp == 0xFF)?7:8
+        MS_tmp = 0
+        MS_bits = 0
+```
+
+---
+
+
+
+---
+
+```
+Procedure: termMSPacker
+```
+
+```
+State: MS_pos, MS_bits, MS_max, MS_tmp
+```
+
+```
+if (MS_bits > 0)
+    while (MS_bits < MS_max)
+        MS_tmp = MS_tmp | (1 << MS_bits)
+        MS_bits = MS_bits + 1
+    if (MS_tmp != 0xFF)
+        MS_buf[MS_pos] = MS_tmp
+        MS_pos = MS_pos + 1
+else if (MS_max == 7)
+    MS_pos = MS_pos - 1 // this discards an already emitted trailing FF
+```
+
+---
+
+An encoder can pad the HT cleanup segment's prefix with additional bytes that are not consumed by the `importMagSgnBit` procedure, and hence do not contribute to the MagSgn bit-stream. Padding can be useful for avoiding buffer underflow in applications with constant data rate constraints. In such a scenario, a recommended strategy is to pad the prefix with pairs of bytes in the range 0xFF80 to 0xFF8F, since these do not introduce false marker codes, yet they can be distinguished from bytes that contain valid data for the MagSgn bit-stream and hence easily removed without any actual decoding.
+
+To generate the VLC byte-stream, the encoder can use the procedure `emitVLCBits` in the following, after initializing state variables with the `initVLCPacker` procedure. The `emitVLCBits` procedure assumes the existence of a buffer (array) denoted `VLC_buf`, with sufficient length to accommodate all generated VLC bytes for the code-block, which can readily be bounded. This array is written forwards here, but needs to be reversed when forming the HT cleanup segment.
+
+---
+
+```
+
+Procedure: initVLCPacker
+State: VLC_pos, VLC_bits, VLC_tmp, VLC_last
+
+```
+
+```
+
+VLC_bits = 4
+VLC_tmp = 15
+VLC_buf[0] = 255
+VLC_pos = 1
+VLC_last = 255
+
+```
+
+---
+
+
+
+---
+
+```
+
+Procedure: emitVLCBits
+
+```
+
+```
+
+Input: cwd and len, where cwd is a len-bit codeword in little-endian bit order
+State: VLC_pos, VLC_bits, VLC_tmp, VLC_last
+
+```
+
+```
+
+while (len > 0)
+    bit = cwd & 1
+    cwd = cwd >> 1
+    len = len - 1
+    VLC_tmp = VLC_tmp | (bit << VLC_bits)
+    VLC_bits = VLC_bits + 1
+    if ((VLC_last > 0x8F) && (VLC_tmp == 0x7F))
+        VLC_bits = VLC_bits + 1
+    if (VLC_bits == 8)
+        VLC_buf[VLC_pos] = VLC_tmp
+        VLC_pos = VLC_pos + 1
+        VLC_last = VLC_tmp
+        VLC_tmp = 0
+        VLC_bits = 0
+
+```
+
+---
+
+To generate the MEL byte-stream, the encoder can use the procedure `emitMELBit` in the following, after initializing state variables with the `initMELPacker` procedure. The `emitMELBit` procedure assumes the existence of a buffer (array) denoted `MEL_buf`, with sufficient length to accommodate all generated MEL bytes for the code-block, which can readily be bounded.
+
+NOTE – The `emitMELBit` procedure is invoked only from the `encodeMEL` procedure.
+
+---
+
+```
+
+Procedure: initMELPacker
+State: MEL_pos, MEL_rem, MEL_tmp
+
+```
+
+```
+
+MEL_pos = 0
+MEL_rem = 8
+MEL_tmp = 0
+
+```
+
+---
+
+---
+
+```
+
+Procedure: emitMELBit
+
+Input: bit
+State: MEL_pos, MEL_rem, MEL_tmp
+
+MEL_tmp = 2*MEL_tmp + bit
+MEL_rem = MEL_rem - 1
+if (MEL_rem == 0)
+    MEL_buf[MEL_pos] = MEL_tmp
+    MEL_pos = MEL_pos + 1
+    MEL_rem = (MEL_tmp == 0xFF)?7:8
+    MEL_tmp = 0
+
+```
+
+---
+
+Once all VLC bits and MEL bits have been emitted for a code-block, the `termMELandVLCPackers` procedure is invoked, as shown in the following. Here, the MEL and VLC byte-streams are not separately terminated, but their state variables are manipulated by the `termMELandVLCPackers` procedure. This is not the only termination procedure that can be used; more aggressive termination schemes can result in the occasional saving of one or even more bytes, by considering larger potential overlaps between the MEL and VLC bit-streams. After invoking the `termMELandVLCPackers` procedure, the HT cleanup segment is formed by concatenating the `MS_pos` byte long terminated `MagSgn` byte-stream, the `MEL_pos` byte long terminated MEL byte-stream and a reversed copy of the `VLC_pos` byte long VLC byte-stream, yielding an array `Dcup` with `Lcup` bytes, the last 2 bytes of which are modified to reflect the suffix length `Scup = MEL_pos + VLC_POS`, as follows:
+
+```
+
+Dcup[Lcup-1] = Scup >> 4
+Dcup[Lcup-2] = (Dcup[Lcup-2] & 0xF0) | (Scup & 0x0F)
+
+```
+
+---
+
+```
+
+Procedure: termMELandVLCPackers
+State: MEL_pos, MEL_rem, MEL_tmp, VLC_pos, VLC_buf, VLC_bits, VLC_last
+
+MEL_tmp = MEL_tmp << MEL_rem
+MEL_mask = (0xFF << MEL_rem) & 0xFF    // if MEL_rem is 8, MEL_mask = 0
+VLC_mask = 0xFF >> (8-VLC_bits)        // if VLC_bits is 0, VLC_mask = 0
+if ((MEL_mask | VLC_mask) == 0)
+    return // last MEL byte cannot be FF, since then MEL_rem would be < 8
+fuse = MEL_tmp | VLC_tmp
+if (((((fuse ^ MEL_tmp) & MEL_mask) | ((fuse ^ VLC_tmp) & VLC_mask)) == 0) &&
+    (fuse != 0xFF))
+    MEL_buf[MEL_pos] = fuse
+else
+    MEL_buf[MEL_pos] = MEL_tmp    // MEL_tmp cannot be 0xFF here
+    VLC_buf[VLC_pos] = VLC_tmp
+    VLC_pos = VLC_pos + 1
+MEL_pos = MEL_pos + 1
+
+```
+
+---
+
+To generate the `SigProp` byte-stream, the encoder passes magnitude and sign bits, as required, to the `emitSPBit` procedure, after initializing state variables with the `initSPPacker` procedure. The `emitSPBit` procedure assumes the existence of a buffer (array) denoted `SP_buf`, with sufficient length to accommodate all generated `SigProp` bytes, which can readily be bounded.
+
+---
+
+```
+
+Procedure: initSPPacker
+State: SP_pos, SP_bits, SP_max, SP_tmp
+
+```
+
+```
+
+SP_pos = 0
+SP_bits = 0
+
+SP_max = 8
+SP_tmp = 0
+
+```
+
+---
+
+
+
+---
+
+```
+
+Procedure: emitSPBit
+Input: bit
+State: SP_pos, SP_bits, SP_max, SP_tmp
+
+```
+
+```
+
+SP_tmp = SP_tmp | (bit << SP_bits)
+SP_bits = SP_bits + 1
+if (SP_bits == SP_max)
+    SP_buf[SP_pos] = SP_tmp
+    SP_pos = SP_pos + 1
+    SP_max = (SP_tmp == 0xFF)?7:8
+    SP_tmp = 0
+    SP_bits = 0
+
+```
+
+---
+
+To generate the MagRef byte-stream, the encoder passes magnitude refinement bits, as required, to the `emitMRBit` procedure, after initializing state variables with the `initMRPacker` procedure. The `emitMRBit` procedure assumes the existence of a buffer (array) denoted `MR_buf`, with sufficient length to accommodate all generated MagRef bytes, which can readily be bounded.
+
+---
+
+```
+
+Procedure: initMRPacker
+State: MR_pos, MR_bits, MR_tmp, MR_last
+
+```
+
+```
+
+MR_pos = 0
+MR_bits = 0
+
+MR_tmp = 0
+MR_last = 255
+
+```
+
+---
+
+---
+
+```
+
+Procedure: emitMRBit
+
+Input: bit
+State: MR_pos, MR_bits, MR_tmp, MR_last
+
+MR_tmp = MR_tmp | (bit << MR_bits)
+MR_bits = MR_bits + 1
+if ((MR_last > 0x8F) && (MR_tmp == 0x7F))
+    MR_bits = MR_bits + 1    // this must leave MR_bits equal to 8
+if (MR_bits == 8)
+    MR_buf[MR_pos] = MR_tmp
+    MR_pos = MR_pos + 1
+    MR_last = MR_tmp
+    MR_tmp = 0
+    MR_bits = 0
+
+```
+
+---
+
+To generate an HT refinement segment that involves no MagRef information, the encoder can terminate the SigProp byte-stream by invoking the `termSPPackers` procedure in the following, after which the terminated `SP_pos` byte long SigProp byte-stream becomes the HT refinement segment.
+
+---
+
+```
+
+Procedure: termSPPackers
+State: SP_pos, SP_bits, SP_max, SP_tmp
+
+if (SP_tmp != 0)
+    SP_buf[SP_pos] = SP_tmp
+    SP_pos = SP_pos + 1
+    SP_max = (SP_tmp == 0xFF) ? 7 : 8
+if (SP_max == 7)
+    SP_buf[SP_pos] = 0x00
+    SP_pos = SP_pos + 1    // this prevents the appearance of a terminal FF
+
+```
+
+---
+
+To generate an HT refinement segment that contains the bits produced by both HT SigProp and HT MagRef coding passes, the encoder can invoke the `termSPandMRPackers` procedure in the following, after which the HT refinement segment is formed by concatenating the `SP_pos` byte long terminated SigProp byte-stream and a reversed copy of the `MR_pos` byte long MagRef byte-stream. In this case, neither the SigProp nor MagRef byte-streams are separately terminated, but their state variables are manipulated by the `termSPandMRPackers` procedure. This is not the only termination procedure that can be used; more aggressive termination schemes can result in the occasional saving of one or even more bytes, by considering larger potential overlaps between the SigProp and MagRef bit-streams.
+
+---
+
+Procedure: termSPandMRPackers
+
+State: SP\_pos, SP\_bits, SP\_max, SP\_tmp, MR\_pos, MR\_buf, MR\_bits, MR\_last
+
+```
+SP_mask = 0xFF >> (8-SP_bits)           // if SP_bits is 0, SP_mask = 0
+SP_mask = SP_mask | ((1<<SP_max) & 0x80) // Augments SP_mask to cover any stuff bit
+MR_mask = 0xFF >> (8-MR_bits)           // if MR_bits is 0, MR_mask = 0
+if ((SP_mask | MR_mask) == 0)
+    return                               // last SP byte cannot be FF, since then SP_max would be 7
+fuse = SP_tmp | MR_tmp
+if (((fuse ^ SP_tmp) & SP_mask) | ((fuse ^ MR_tmp) & MR_mask)) == 0)
+    SP_buf[SP_pos] = fuse                // fuse always < 0x80 here; no false marker risk
+else
+    SP_buf[SP_pos] = SP_tmp              // SP_tmp cannot be 0xFF
+    MR_buf[MR_pos] = MR_tmp
+    MR_pos = MR_pos + 1
+SP_pos = SP_pos + 1
+```
+
+---
+
+# Bibliography
+
+- Recommendation ITU-T T.801 (2002) | ISO/IEC 15444-2:2002, *Information technology – JPEG 2000 image coding system: Extensions*.
+- IETF RFC 6838 (2013), *Media type specifications and registration procedures*.
+
+
+
+# SERIES OF ITU-T RECOMMENDATIONS
+
+|                 |                                                                                                                                                           |
+|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Series A        | Organization of the work of ITU-T                                                                                                                         |
+| Series D        | Tariff and accounting principles and international telecommunication/ICT economic and policy issues                                                       |
+| Series E        | Overall network operation, telephone service, service operation and human factors                                                                         |
+| Series F        | Non-telephone telecommunication services                                                                                                                  |
+| Series G        | Transmission systems and media, digital systems and networks                                                                                              |
+| Series H        | Audiovisual and multimedia systems                                                                                                                        |
+| Series I        | Integrated services digital network                                                                                                                       |
+| Series J        | Cable networks and transmission of television, sound programme and other multimedia signals                                                               |
+| Series K        | Protection against interference                                                                                                                           |
+| Series L        | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant |
+| Series M        | Telecommunication management, including TMN and network maintenance                                                                                       |
+| Series N        | Maintenance: international sound programme and television transmission circuits                                                                           |
+| Series O        | Specifications of measuring equipment                                                                                                                     |
+| Series P        | Telephone transmission quality, telephone installations, local line networks                                                                              |
+| Series Q        | Switching and signalling, and associated measurements and tests                                                                                           |
+| Series R        | Telegraph transmission                                                                                                                                    |
+| Series S        | Telegraph services terminal equipment                                                                                                                     |
+| <b>Series T</b> | <b>Terminals for telematic services</b>                                                                                                                   |
+| Series U        | Telegraph switching                                                                                                                                       |
+| Series V        | Data communication over the telephone network                                                                                                             |
+| Series X        | Data networks, open system communications and security                                                                                                    |
+| Series Y        | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities                               |
+| Series Z        | Languages and general software aspects for telecommunication systems                                                                                      |
\ No newline at end of file
diff --git a/marked/T/T-REC-T.816-202302-I_PDF-E/raw.md b/marked/T/T-REC-T.816-202302-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..9a88ef8cfbd4ff071c5e2ebc82b93b725cb77678
--- /dev/null
+++ b/marked/T/T-REC-T.816-202302-I_PDF-E/raw.md
@@ -0,0 +1,2643 @@
+
+
+# Recommendation**ITU-T T.816 (V1) (02/2023)**
+
+SERIES T: Terminals for telematic services
+
+Still-image compression – JPEG 2000
+
+---
+
+**Information technology – JPEG 2000 image coding system: Extensions for coding of discontinuous media**
+
+## ITU-T T-SERIES RECOMMENDATIONS **TERMINALS FOR TELEMATIC SERVICES**
+
+|                                                     |                    |
+|-----------------------------------------------------|--------------------|
+| Facsimile – Framework                               | T.0–T.19           |
+| Still-image compression – Test charts               | T.20–T.29          |
+| Facsimile – Group 3 protocols                       | T.30–T.39          |
+| Colour representation                               | T.40–T.49          |
+| Character coding                                    | T.50–T.59          |
+| Facsimile – Group 4 protocols                       | T.60–T.69          |
+| Telematic services – Framework                      | T.70–T.79          |
+| Still-image compression – JPEG-1, Bi-level and JBIG | T.80–T.89          |
+| Telematic services – ISDN Terminals and protocols   | T.90–T.99          |
+| Videotext – Framework                               | T.100–T.109        |
+| Data protocols for multimedia conferencing          | T.120–T.149        |
+| Telewriting                                         | T.150–T.159        |
+| Multimedia and hypermedia framework                 | T.170–T.189        |
+| Cooperative document handling                       | T.190–T.199        |
+| Telematic services – Interworking                   | T.300–T.399        |
+| Open document architecture                          | T.400–T.429        |
+| Document transfer and manipulation                  | T.430–T.449        |
+| Document application profile                        | T.500–T.509        |
+| Communication application profile                   | T.510–T.559        |
+| Telematic services – Equipment characteristics      | T.560–T.619        |
+| General multimedia application frameworks           | T.620–T.649        |
+| User interfaces - Accessibility and human factors   | T.700–T.799        |
+| <b>Still-image compression – JPEG 2000</b>          | <b>T.800–T.829</b> |
+| Still-image compression   JPEG XR                   | T.830–T.849        |
+| Still-image compression – JPEG-1 extensions         | T.850–T.899        |
+
+*For further details, please refer to the list of ITU-T Recommendations.*
+
+# **Information technology – JPEG 2000 image coding system: Extensions for coding of discontinuous media**
+
+# Summary
+
+Rec. ITU-T T.816 | ISO/IEC 15444-17 provides extensions of the scalable image coding tools described in Rec. ITU-T T.800 | ISO/IEC 15444-1 and Rec. ITU-T T.801 | ISO/IEC 15444-2, of two types. First, new wavelet-like image transforms known as "breakpoint-dependent" transforms are defined, whose underlying basis functions can be discontinuous at defined locations within the image component to which they are applied. Second, new scalable coding tools are described for a new type of image component known as a "breakpoint component", which provides a successively refinable and hierarchical description of the breakpoint locations used by the breakpoint-dependent transforms. Any non-initial component or components within a codestream conforming to this Recommendation | International Standard can be breakpoint components and any of the components in the codestream other than breakpoint components can use a breakpoint-dependent transform that depends upon one of the breakpoint components in the same codestream. These new tools together allow for the scalable coding of imagery that naturally exhibits strong discontinuities in the spatial domain. An important example of such imagery is depth maps.
+
+This Recommendation was developed jointly with ISO/IEC JTC 1/SC 29/WG 1 (JPEG) and is common text with ISO/IEC 15444-17.
+
+# History
+
+| Edition | Recommendation   | Approval   | Study Group | Unique ID*                                                                |
+|---------|------------------|------------|-------------|---------------------------------------------------------------------------|
+| 1.0     | ITU-T T.816 (V1) | 2023-02-13 | 16          | <a href="http://handle.itu.int/11.1002/1000/15206">11.1002/1000/15206</a> |
+
+---
+
+\* To access the Recommendation, type the URL <http://handle.itu.int/> in the address field of your web browser, followed by the Recommendation's unique ID. For example, <http://handle.itu.int/11.1002/1000/11830-en>.
+
+## FOREWORD
+
+The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis.
+
+The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics.
+
+The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1.
+
+In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC.
+
+## NOTE
+
+In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party.
+
+## INTELLECTUAL PROPERTY RIGHTS
+
+ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process.
+
+As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at <http://www.itu.int/ITU-T/ipr/>.
+
+© ITU 2023
+
+All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU.
+
+# CONTENTS
+
+|                                                                                        | Page |
+|----------------------------------------------------------------------------------------|------|
+| 1 Scope.....                                                                           | 1    |
+| 2 Normative references .....                                                           | 1    |
+| 3 Terms and definitions.....                                                           | 1    |
+| 4 Abbreviations .....                                                                  | 2    |
+| 5 5 Conventions.....                                                                   | 3    |
+| 6 Conformance .....                                                                    | 3    |
+| 6.1 Codestream conformance .....                                                       | 3    |
+| 6.2 Decoder.....                                                                       | 3    |
+| 7 Breakpoint component structure.....                                                  | 4    |
+| 7.1 Breakpoint components and the reference grid.....                                  | 4    |
+| 7.2 Division of breakpoint resolutions into cells, arcs and the CL band.....           | 4    |
+| 7.3 Division of breakpoint resolutions into precincts and code-blocks .....            | 5    |
+| 7.4 Root and non-root arc breakpoint associations.....                                 | 7    |
+| 7.5 Breakpoint values and vertices .....                                               | 8    |
+| 8 Breakpoint-dependent spatial wavelet transformation .....                            | 10   |
+| 8.1 Overview .....                                                                     | 10   |
+| 8.2 TriBPT-dependent irreversible transforms .....                                     | 11   |
+| 8.2.1 Introduction.....                                                                | 11   |
+| 8.2.2 Arcs with $tb = 0$ .....                                                         | 12   |
+| 8.2.3 Arcs with $tb = 3$ .....                                                         | 13   |
+| 8.2.4 Arcs with $tb = 2$ .....                                                         | 13   |
+| 8.2.5 Arcs with $tb = 1$ .....                                                         | 17   |
+| 8.3 TriBPT-dependent reversible transforms.....                                        | 21   |
+| 8.3.1 Arcs with $tb = 0$ .....                                                         | 22   |
+| 8.3.2 Arcs with $tb = 3$ .....                                                         | 22   |
+| 8.3.3 Arcs with $tb = 2$ .....                                                         | 22   |
+| 8.3.4 Arcs with $tb = 1$ .....                                                         | 22   |
+| 8.4 QuadBPT-dependent transforms.....                                                  | 23   |
+| 8.4.1 Introduction.....                                                                | 23   |
+| 8.4.2 BD_2D_SR phase 1 .....                                                           | 24   |
+| 8.4.3 BD_2D_SR phase 2 .....                                                           | 26   |
+| 9 Decoding of breakpoint code-blocks.....                                              | 28   |
+| 9.1 Embedded bit-plane decoding of breakpoints.....                                    | 28   |
+| 9.2 Inter-band coding mode (BPT_INTER) .....                                           | 29   |
+| 9.3 Cell-based scanning patterns and CBAP-based block flipping.....                    | 30   |
+| 9.4 QuadBPT decoding procedures .....                                                  | 32   |
+| 9.4.1 MQ Coder contexts and initial states for QuadBPT decoding .....                  | 32   |
+| 9.4.2 Derivation of context labels for QuadBPT CL band significance coding passes..... | 33   |
+| 9.4.3 Non-root significance decoding for QuadBPT CL code-blocks .....                  | 35   |
+| 9.4.4 Root significance decoding for QuadBPT CL code-blocks .....                      | 36   |
+| 9.4.5 Root significance decoding for QuadBPT LL code-blocks .....                      | 37   |
+| 9.4.6 Position refinement decoding for QuadBPT code-blocks.....                        | 37   |
+| 9.5 TriBPT decoding procedures .....                                                   | 38   |
+| 9.5.1 MQ Coder contexts and initial states for TriBPT decoding .....                   | 38   |
+| 9.5.2 Derivation of context labels for TriBPT CL band significance coding passes.....  | 39   |
+| 9.5.3 Non-root significance decoding for TriBPT CL code-blocks .....                   | 42   |
+| 9.5.4 Root significance decoding for TriBPT CL code-blocks.....                        | 43   |
+| 9.5.5 Root significance decoding for TriBPT LL code-blocks.....                        | 44   |
+| 9.5.6 Position refinement decoding for TriBPT code-blocks.....                         | 45   |
+| 9.6 Quality layers and packets for breakpoint components .....                         | 45   |
+| 10 Reconstruction of breakpoint components .....                                       | 47   |
+| 10.1 Overview .....                                                                    | 47   |
+| 10.2 Direct induction step.....                                                        | 47   |
+| 10.2.1 Introduction.....                                                               | 47   |
+| 10.2.2 Extrapolation Qualifier for TriBPT direct induction.....                        | 48   |
+
+|                                                                                                                                                                         | <b>Page</b> |
+|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------|
+| 10.3 QuadBPT spatial induction.....                                                                                                                                     | 49          |
+| 10.3.1 Introduction.....                                                                                                                                                | 49          |
+| 10.4 TriBPT spatial induction.....                                                                                                                                      | 51          |
+| 10.4.1 TriBPT induction modes and corner notation.....                                                                                                                  | 51          |
+| 10.4.2 4-arc mode.....                                                                                                                                                  | 51          |
+| 10.4.3 3-arc mode.....                                                                                                                                                  | 52          |
+| 10.4.4 Extrapolation qualifier for TriBPT spatial induction.....                                                                                                        | 53          |
+| 10.4.5 Rounding policies for TriBPT spatial induction.....                                                                                                              | 56          |
+| 10.4.6 Image boundary handling for TriBPT.....                                                                                                                          | 56          |
+| Annex A (This annex forms an integral part of this Recommendation   International Standard.) – Codestream syntax...                                                     | 58          |
+| A.1 General.....                                                                                                                                                        | 58          |
+| A.2 SIZ marker segment.....                                                                                                                                             | 58          |
+| A.3 CAP marker segment.....                                                                                                                                             | 58          |
+| A.4 Hierarchical data type (HDT) marker segment.....                                                                                                                    | 59          |
+| A.5 COD and COC marker segments.....                                                                                                                                    | 59          |
+| Annex B (This annex does not form an integral part of this Recommendation   International Standard) –<br>Hierarchical breakpoint encapsulation and raw file format..... | 62          |
+| B.1 General.....                                                                                                                                                        | 62          |
+| B.2 Raster organization of breakpoints.....                                                                                                                             | 62          |
+| B.3 16- and 32-bit packed breakpoint values.....                                                                                                                        | 63          |
+| B.4 A raw file format for breakpoints.....                                                                                                                              | 64          |
+| Bibliography.....                                                                                                                                                       | 67          |
+
+## List of Tables
+
+|                                                                                                                                                                                                                   | <b>Page</b> |
+|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------|
+| Table 1 – Constraints on PPx and PPy precinct size parameters breakpoint components.....                                                                                                                          | 6           |
+| Table 2 – MQ coder contexts for QuadBPT CL code-block decoding passes. State index values correspond to the Qe values and probability estimation transitions tabulated in Rec. ITU-T T.800   ISO/IEC 15444-1..... | 33          |
+| Table 3 – Context labels from Table 2 that are used for QuadBPT LL code-block decoding passes.....                                                                                                                | 33          |
+| Table 4 – MQ coder contexts for TriBPT CL code-block decoding passes. State index values correspond to the Qe values and probability estimation transitions tabulated in Rec. ITU-T T.800   ISO/IEC 15444-1.....  | 38          |
+| Table 5 – Context labels from Table 4 that are used for TriBPT LL code-block decoding passes.....                                                                                                                 | 38          |
+| Table A.1 – Extensions and constraints to marker segments specified in Rec. ITU-T T.800   ISO/IEC 15444-1 and new marker segments specified in this Recommendation   International Standard.....                  | 58          |
+| Table A.2 – Ccap <sup>17</sup> Syntax and Semantics.....                                                                                                                                                          | 58          |
+| Table A.3 – Hierarchical data type parameter values.....                                                                                                                                                          | 59          |
+| Table A.4 – Allowed values for Ihdt <sup>i</sup> .....                                                                                                                                                            | 59          |
+| Table A.5 – Scod and Scoc semantics for bit 5.....                                                                                                                                                                | 60          |
+| Table A.6 – SXcod bit fields specified by this Recommendation   International Standard.....                                                                                                                       | 60          |
+| Table A.7 – Allowed values for the SEcod field.....                                                                                                                                                               | 61          |
+| Table A.8 – Transformation for the SPcod and SPcoc parameters when Dc ≠ 0.....                                                                                                                                    | 61          |
+
+# List of Figures
+
+|                                                                                                                                                                                                                                                   | Page |
+|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------|
+| Figure 1 – Arc arrangements within a single 2-span. A $2 \times 2$ cell is shown here with solid grid-points. See Figure 2 for other geometric relationships between cells and 2-spans.....                                                       | 5    |
+| Figure 2 – Cell-span geometry for each of the four possible code-block anchor points.....                                                                                                                                                         | 5    |
+| Figure 3 – Root arc (dotted lines) and non-root arcs (solid lines).....                                                                                                                                                                           | 8    |
+| Figure 4 – Possible break locations (tick-points) at the finest resolution, with $FB = 2$ , shown for the QuadBPT case. Also shows the mapping of vertices with precision $Pb$ to tick-points .....                                               | 9    |
+| Figure 5 – Stages of the breakpoint dependent inverse discrete wavelet transform .....                                                                                                                                                            | 10   |
+| Figure 6 – Interleaving of sub-band coefficients to a triangular grid for a given resolution $r$ .....                                                                                                                                            | 12   |
+| Figure 7 – Update step examples for TriBPT-LR arrangement.....                                                                                                                                                                                    | 12   |
+| Figure 8 – Predict step examples for a horizontal arc.....                                                                                                                                                                                        | 12   |
+| Figure 9 – Example of direct induction of a breakpoint .....                                                                                                                                                                                      | 14   |
+| Figure 10 – Example illustrating spatially induced breaks .....                                                                                                                                                                                   | 14   |
+| Figure 11 – Example of a spatially induced breakpoint on a non-root arc for the TriBPT-LR arrangement.....                                                                                                                                        | 15   |
+| Figure 12 – Examples showing base-arc $bsa$ and gradients $Gbsa$ and $Gwdg$ along with corresponding binary flags ORN and <b>DRCTNX_FLAG induced</b> for root arcs .....                                                                          | 16   |
+| Figure 13 – Example showing base-arc $bsa$ and gradients $Gbsa$ and $Gwdg$ along with corresponding binary flags ORN and <b>DRCTNX_FLAG induced</b> for diagonal non-root arc containing a spatially induced break .....                          | 16   |
+| Figure 14 – Examples of arcs $prl$ parallel in orientation to root arcs centred at $p$ and containing a spatially induced break. Gradient calculated across arc $prl$ is denoted as $Gprl$ .....                                                  | 19   |
+| Figure 15 – Example of arc $prl$ parallel to the non-root arc centred and at $p$ and containing a spatially induced break. Corresponding gradient across arc $prl$ is shown as $Gprl$ .....                                                       | 19   |
+| Figure 16 – Algorithm for determining the gradient $Gb$ based on validity flags VALID_WDG and VALID_PRL and corresponding attributes.....                                                                                                         | 20   |
+| Figure 17 – Parent 4-span arrangement at resolution $r_{rt} = r - 1$ for arc $a$ at resolution $r$ and centred at $p$ .....                                                                                                                       | 21   |
+| Figure 18 – Algorithm for determining the gradient $Gb$ for the reversible transform, based on validity flags VALID_WDG and VALID_PRL and corresponding attributes.....                                                                           | 23   |
+| Figure 19 – Interleaving of sub-band coefficients to a quadrilateral grid for a given resolution $r$ .....                                                                                                                                        | 23   |
+| Figure 20 – Phase 1 update step for (even, even) location $2n, 2m$ .....                                                                                                                                                                          | 24   |
+| Figure 21 – Phase 1 update step for (even, odd) location $2n, 2m + 1$ and (odd, even) location $2n + 1, 2m$ .....                                                                                                                                 | 25   |
+| Figure 22 – Phase 1 predict step for (odd, odd) location $2n + 1, 2m + 1$ with source locations of $Ic, r$ *shown.....                                                                                                                            | 26   |
+| Figure 23 – Phase 2 update step for (even, even) location $2n, 2m$ .....                                                                                                                                                                          | 27   |
+| Figure 24 – Phase 2 predict step examples .....                                                                                                                                                                                                   | 28   |
+| Figure 25 – Canonical scanning pattern used for the significance coding passes of CL band code-blocks in a QuadBPT component. In this case, missing cells within a $2 \times 2$ group are not included in the scan .....                          | 30   |
+| Figure 26 – Canonical scanning pattern used for the significance coding passes of CL band code-blocks in TriLR components. Arcs belonging to cells that lie beyond the code-block boundaries are included in the significance coding passes ..... | 31   |
+| Figure 27 – Canonical scanning pattern used for the significance coding passes of CL band code-blocks in TriRL components. Arcs belonging to cells that lie beyond the code-block boundaries are included in the significance coding passes ..... | 31   |
+| Figure 28 – Neighbouring cells and arcs involved in forming coding contexts for QuadBPT significance decoding in CL band code-blocks .....                                                                                                        | 34   |
+| Figure 29 – Neighbouring cells and arcs involved in forming coding contexts for TriLR significance decoding in CL band code-blocks .....                                                                                                          | 39   |
+
+|                                                                                                                                                                                                                                                       | <b>Page</b> |
+|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------|
+| Figure 30 – Neighbouring cells and arcs involved in forming coding contexts for TriRL significance decoding in CL band code-blocks .....                                                                                                              | 40          |
+| Figure 31 – Breakpoint synthesis stages.....                                                                                                                                                                                                          | 47          |
+| Figure 32 – Relationship between non-root and parent arcs during direct induction in synthesis stage $r$ , shown for the case of horizontal arcs.....                                                                                                 | 48          |
+| Figure 33 – Rounding policies used in QuadBPT spatial induction, showing different induction examples in three of the four 2-spans within a 4-span.....                                                                                               | 50          |
+| Figure 34 – Arc and corner labels for the TriBPT-LR arrangement.....                                                                                                                                                                                  | 51          |
+| Figure 35 – 4-arc mode spatial induction examples for the TriBPT-LR arrangement.....                                                                                                                                                                  | 52          |
+| Figure 36 – 3-arc mode spatial induction examples for the TriBPT-LR arrangement.....                                                                                                                                                                  | 53          |
+| Figure 37 – Example of intersection points, arcs and grid-lines required for determining the extrapolation qualifier for a spatially induced break .....                                                                                              | 55          |
+| Figure 38 – Examples of rounding policy for 3-arc mode spatial induction when the inducing line intersects the root arc $X$ at its centre. The direction of rounding is highlighted by the black arrows .....                                         | 56          |
+| Figure A.1 – Hierarchical data type syntax .....                                                                                                                                                                                                      | 59          |
+| Figure A.2 – Coding style default syntax .....                                                                                                                                                                                                        | 60          |
+| Figure A.3 – Coding style component syntax.....                                                                                                                                                                                                       | 60          |
+| Figure B.1 – Bit fields within 16- and 32-bit packed breakpoint representations. The most significant bit of the 16- or 32-bit integer, as appropriate, is shown at the top of the figure, while the least significant bit appears at the bottom..... | 64          |
+
+# Introduction
+
+The JPEG 2000 core coding system specified in Rec. ITU-T T.800 | ISO/IEC 15444-1 and its extensions specified in Rec. ITU-T T.801 | ISO/IEC 15444-2 provide a suite of scalable coding technologies that are particularly suitable for photographic media, but less effective at coding media with hard discontinuities. An important example of such media is depth imagery, where each image sample is related to the length of the 3D line segment between the corresponding scene point and the camera. Depth imagery includes stereo disparity maps, where sample values are reciprocally related to depth. Another example of media with strong discontinuities is optical flow data, where each sample location is a two-dimensional vector. In these examples, discontinuities arise naturally at the boundaries of scene objects. Moreover, where this happens, intermediate values that might be obtained by bandlimited image resampling or interpolation operations have no physical meaning – i.e., they do not correspond to the depth or flow vector of any object in the original scene. The discrete wavelet transform (DWT) employed in JPEG 2000 is not well suited to the coding of such media, both from the perspective of coding efficiency and considering the nature of distortions that result when the wavelet sub-band samples are quantized.
+
+To address these challenges, this Recommendation | International Standard introduces alternate "breakpoint-dependent" spatial wavelet transforms that are dependent on an auxiliary image component, known as a "breakpoint component." This Recommendation | International Standard also introduces scalable coding technologies for breakpoint components. Any non-initial component or components within the codestream can be designated as breakpoint components, allowing them to be used as the source of breakpoints for other components, or tiles thereof, which specify the use of breakpoint-dependent wavelet transforms.
+
+This Recommendation | International Standard specifies two different types of breakpoint components, designated as "QuadBPT" and "TriBPT" components, with associated decoding and synthesis tools. Associated with the type of breakpoint component is a corresponding breakpoint-dependent wavelet transform, with its synthesis tools. The reconstruction procedures described in this Recommendation | International Standard produce individual sample values. In the TriBPT case, it is possible instead to directly reconstruct a deformable triangular mesh, whose complexity is related to the number of non-zero wavelet coefficients and the number of decoded breaks, which are identified here as "vertices." In each case, breakpoints introduce tears in the mesh. This feature can be valuable in computer graphics applications, where the mesh elements provide a more convenient description of the data than individual samples.
+
+The normative material of this Recommendation | International Standard is contained within the main body together with Annex A. Additionally, Annex B describes ways of encapsulating breakpoint data within a linear file structure, that can be used as a source for encoding and a target for decoding procedures.
+
+
+
+# INTERNATIONAL STANDARD ITU-T RECOMMENDATION
+
+# **Information technology – JPEG 2000 image coding system: Extensions for coding of discontinuous media**
+
+# 1 Scope
+
+This Recommendation | International Standard defines QuadBPT and TriBPT image components, collectively known as "breakpoint components", and specifies decoding and reconstruction procedures for recovering breakpoint component sample values from the codestream. This Recommendation | International Standard also specifies "breakpoint-dependent" spatial wavelet transforms that can be used in place of the transforms specified in Recommendation ITU-T T.800 | ISO/IEC 15444-1 for selected image components or tile-components. Extensions to the codestream syntax of Rec. ITU-T T.800 | ISO/IEC 15444-1 are specified to enable the identification of breakpoint components, of components that can use a breakpoint-dependent spatial wavelet transform, and the association of breakpoint components with such breakpoint-dependent wavelet transforms.
+
+# 2 Normative references
+
+The following Recommendations and International Standards contain provisions which, through reference in this text, constitute provisions of this Recommendation | International Standard. At the time of publication, the editions indicated were valid. All Recommendations and Standards are subject to revision, and parties to agreements based on this Recommendation | International Standard are encouraged to investigate the possibility of applying the most recent edition of the Recommendations and Standards listed below. Members of IEC and ISO maintain registers of currently valid International Standards. The Telecommunication Standardization Bureau of the ITU maintains a list of currently valid ITU-T Recommendations.
+
+## 2.1 Identical Recommendations | International Standards
+
+- Recommendation ITU-T T.800 (2019) | ISO/IEC 15444-1:2019, *Information technology – JPEG 2000 image coding system: Core coding system*.
+- Recommendation ITU-T T.801 (2021) | ISO/IEC 15444-2:2021, *Information technology – JPEG 2000 image coding system: Extensions*.
+
+# 3 Definitions
+
+## 3.1 Terms defined elsewhere
+
+For the purposes of this Recommendation | International Standard, the terms and definitions given in Rec. ITU-T T.800 | ISO/IEC 15444-1 apply.
+
+ITU, ISO and IEC maintain terminological databases for use in standardization at the following addresses:
+
+- ITU Terms and definitions database: available at <https://www.itu.int/go/terms>
+- ISO Online browsing platform: available at <https://www.iso.org/obp>
+- IEC Electropedia: available at <http://www.electropedia.org/>
+
+## 3.2 Terms defined in this Recommendation | International Standard
+
+This Recommendation | International Standard defines the following terms:
+
+**3.2.1 2-span:** Square configuration of width 2 and height 2, with 9 grid-points, such that the four corner grid-points all have coordinates that are divisible by 2.
+
+**3.2.2 4-span:**  $2 \times 2$  configuration of 2-spans (3.2.1), involving 25 grid-points, such that the four corner grid-points all have coordinates that are divisible by 4.
+
+**3.2.3 ambivalent break:** Induced break (3.2.5) that has insufficient precision to determine whether the break occurs in the first or second half of the arc.
+
+**3.2.4 arc:** Line segment connecting grid-points with even valued coordinates at any resolution of a breakpoint tile-component.
+
+**3.2.5 break:** Explicitly decoded or inferred location within an arc (3.2.4) that indicates a boundary within an image component.
+
+NOTE 1 – Breaks modify the behaviour of breakpoint-dependent transforms on that other image component.
+
+NOTE 2 – An arc has at most one break.
+
+**3.2.6 breakpoint:** Data structure consisting of break type, location and precision information for an arc (3.2.4).
+
+NOTE – Type-0 breakpoints have no break at all.
+
+**3.2.7 breakpoint component:** JPEG 2000 codestream image component that represents arc breakpoint (3.2.6) information.
+
+**3.2.8 breakpoint tile-component:** All the breakpoints of a given tile, within a breakpoint component (3.2.7).
+
+**3.2.9 cell:**  $2 \times 2$  configuration of grid-points within a resolution of a breakpoint tile-component (3.2.8).
+
+NOTE – Cells belong to a well-defined partition that is anchored at the global code-block anchor point.
+
+**3.2.10 CL band:** The sole sub-band associated with each resolution of a breakpoint tile-component (3.2.8) other than the lowest resolution.
+
+**3.2.11 code-block anchor point:** Origin of the coding partitions, which is one of the locations (0,0), (0,1), (1,0) or (1,1).
+
+[SOURCE: Rec. ITU-T T.801 | ISO/IEC 15444-2]
+
+**3.2.12 directly induced break:** Break (3.2.5) on an arc that is inferred from a break on a parent arc.
+
+**3.2.13 extrapolation qualifier:** 2-bit quantity  $e_b$  which controls the way gradients are obtained for extrapolation within a TriBPT-dependent transformation.
+
+**3.2.14 indefinite break:** Induced break (3.2.15) on an arc that is derived from one or more ambivalent breaks (3.2.3), such that there is insufficient precision to determine whether any break at all exists on the arc.
+
+**3.2.15 induced break:** Break (3.2.5) on an arc that is inferred from breaks on other arcs.
+
+**3.2.16 induction block:** Condition on an arc (3.2.4) that is explicitly recovered from the decoding of breakpoint code-blocks, indicating that no break (3.2.5) shall be induced on that arc.
+
+**3.2.17 non-root arc:** Arc (3.2.4) that is not a root arc.
+
+**3.2.18 parent arc:** Arc (3.2.4) at depth  $d + 1$  in the breakpoint decomposition that contains an arc at depth  $d$ .
+
+NOTE – At most two arcs at depth  $d$  can have the same parent at depth  $d + 1$ .
+
+**3.2.19 pass-complete:** Code-block within a breakpoint component for which one or more coding passes are found within the codestream packets and the last such coding pass is identified as completing the code-block's representation via the packet header signalling mechanisms.
+
+**3.2.20 QuadBPT:** Breakpoint (3.2.6) arrangement involving only horizontal and vertical arcs (3.2.4).
+
+**3.2.21 root arc:** Arc (3.2.4) that is not contained within any arc projected from the next lower resolution of a breakpoint tile-component (3.2.8), regardless of whether that next lower resolution actually exists within the tile-component's resolution hierarchy.
+
+**3.2.22 spatially induced break:** Induced break (3.2.15) that is inferred from breaks on non-parent arcs.
+
+**3.2.23 tick-point:** Possible break (3.2.5) location along an arc.
+
+**3.2.24 TriBPT:** Breakpoint (3.2.6) arrangement involving horizontal, vertical and diagonal arcs (3.2.4).
+
+**3.2.25 TriBPT-LR:** TriBPT (3.2.24) breakpoint arrangement involving diagonal arcs that run from the top-left to the bottom-right of a 2-span within any resolution of a breakpoint tile-component (3.2.8).
+
+**3.2.26 TriBPT-RL:** TriBPT (3.2.24) breakpoint arrangement involving diagonal arcs that run from the top-right to the bottom-left of a 2-span within any resolution of a breakpoint tile-component (3.2.8).
+
+**3.2.27 vertex:** Explicitly coded break (3.2.5) location.
+
+**3.2.28 zero-complete:** Code-block within a breakpoint component (3.2.7) that makes no contribution to any codestream packet and is identified as complete by the first packet header of its precinct.
+
+# 4 Abbreviations
+
+For the purposes of this Recommendation | International Standard, the following abbreviations apply:
+
+BD-IDWT Breakpoint-Dependent Inverse Discrete Wavelet Transformation
+
+|      |                         |
+|------|-------------------------|
+| BGP  | Base Grid Point         |
+| BIL  | Break Inducing Line     |
+| BIP  | Base Intersection Point |
+| BLN  | Base Line               |
+| BSA  | Base Arc                |
+| CBAP | Code-Block Anchor Point |
+| DIB  | Directly Induced Breaks |
+| HDT  | Hierarchical Data Type  |
+| HGP  | Horizontal Grid-Point   |
+| MPS  | More Probable Symbol    |
+| RAC  | Round Away from Centre  |
+| RTN  | Round to Nearest        |
+| SBR  | Source Breaks           |
+| SPB  | Spatially induced Break |
+| TPS  | Tick-Points             |
+| VMR  | Vertex Mapping Rule     |
+| VRT  | Vertex                  |
+| WDA  | Wedge Area              |
+
+# 5 Conventions
+
+This Recommendation | International Standard uses the following conventions:
+
+- **CBAP** ( $z_x, z_y$ ) – code-block anchor point
+- **MAX\_WDG** – maximum search distance for the gradient extrapolation algorithm used during the TriBPT-dependent prediction step associated with a spatially induced arc.
+- **BPT\_INTER** – binary flag that is 1 if code-blocks of a breakpoint component use the inter-band coding mode and 0 if the code-blocks of a breakpoint component are coded without reference to any other code-block data.
+
+# 6 Conformance
+
+## 6.1 Codestream conformance
+
+A codestream conforming to this Specification shall conform to Annex A.
+
+## 6.2 Decoder
+
+A decoder conforming to this Specification shall process a codestream that conforms to this Specification in the manner specified in Rec. ITU-T T.800 | ISO/IEC 15444-1 together with any additional signalled capability specified in this Specification, with the exception of breakpoint components and tile-components that identify the use of a breakpoint-dependent spatial wavelet transform, in which case the following shall apply:
+
+- breakpoint components shall have the structure specified in clause 7;
+- tile-components that use a breakpoint-dependent spatial wavelet transform shall be processed in accordance with clause 8; and
+- breakpoint components shall be reconstructed from breakpoint code-blocks in accordance with clause 10, where breakpoint code-blocks are decoded in accordance with clause 9.
+
+This Recommendation | International Standard is compatible with the coding technologies specified in both Rec. ITU-T T.800 | ISO/IEC 15444-1 and Rec. ITU-T T.801 | ISO/IEC 15444-2. However:
+
+1. Breakpoint components, as specified herein, are not compatible with the multiple component transformations specified in Rec. ITU-T T.800 | ISO/IEC 15444-1 and Rec. ITU-T T.801 | ISO/IEC 15444-2, nor are they compatible with the non-linear transformations specified in Rec. ITU-T T.801 | ISO/IEC 15444-2; and
+2. Breakpoint code-blocks, as specified herein, are not compatible with the region of interest coding and extraction techniques specified in Rec. ITU-T T.800 | ISO/IEC 15444-1 and Rec. ITU-T T.801 | ISO/IEC 15444-2.
+
+# 7 Breakpoint component structure
+
+## 7.1 Breakpoint components and the reference grid
+
+Breakpoint components have a "hierarchical data type", meaning that they are described at multiple resolutions, in a dyadic hierarchy. Breakpoint components are identified via the HDT marker segment defined in A.4. In particular, component  $c$  is a breakpoint component if  $\text{Ihd}^c$  lies in the range 1 to 3.
+
+Breakpoint component  $c$  is defined with respect to the same reference grid as other JPEG 2000 components, in terms of the global image dimensions ( $X_{\text{siz}}, Y_{\text{siz}}$ ), image offset ( $XO_{\text{siz}}, YO_{\text{siz}}$ ) and sampling factors ( $XR_{\text{siz}}^c, YR_{\text{siz}}^c$ ) that are recorded in the SIZ marker segment. The *grid-points* of component  $c$  consist of all integer coordinates in the rectangle with upper left hand corner at  $(x_o, y_o)$  and lower right hand corner at  $(x_l - 1, y_l - 1)$ , where
+
+$$x_o = \left\lfloor \frac{XO_{\text{siz}}}{XR_{\text{siz}}^c} \right\rfloor, \quad x_l = \left\lfloor \frac{X_{\text{siz}}}{XR_{\text{siz}}^c} \right\rfloor, \quad y_o = \left\lfloor \frac{YO_{\text{siz}}}{YR_{\text{siz}}^c} \right\rfloor, \quad y_l = \left\lfloor \frac{Y_{\text{siz}}}{YR_{\text{siz}}^c} \right\rfloor. \quad (1)$$
+
+These formulae are identical to the equations for  $x_o, x_l, y_o$  and  $y_l$  in Rec. ITU-T T.800 | ISO/IEC 15444-1, but note that the term *grid-points* is used here for the locations of a breakpoint component, rather than *samples*.
+
+As with other components, breakpoint components are partitioned into tile-components, following the partitioning of the reference grid into tiles, so that the grid-points of a breakpoint tile-component, having component index  $c$  belong to the rectangle with upper left corner at  $(tcx_o, tcy_o)$  and lower right hand corner at  $(tcx_l - 1, tcy_l - 1)$ , where
+
+$$tcx_o = \left\lfloor \frac{tx_o}{XR_{\text{siz}}^c} \right\rfloor, \quad tcx_l = \left\lfloor \frac{tx_l}{XR_{\text{siz}}^c} \right\rfloor, \quad tcy_o = \left\lfloor \frac{ty_o}{YR_{\text{siz}}^c} \right\rfloor, \quad tcy_l = \left\lfloor \frac{ty_l}{YR_{\text{siz}}^c} \right\rfloor, \quad (2)$$
+
+where the tile in question occupies the rectangle with top left corner at  $(tx_o, ty_o)$  and lower right corner at  $(tx_l - 1, ty_l - 1)$  on the reference grid. These formulae are identical to the equations for  $tcx_o, tcx_l, tcy_o$  and  $tcy_l$  in Rec. ITU-T T.800 | ISO/IEC 15444-1, except that the breakpoint tile-component's locations are identified as *grid-points* rather than *samples*.
+
+Like other JPEG 2000 components, each breakpoint tile-component has an associated number of *decomposition levels*  $N_L$ , that is identified via the applicable COD or COC marker segment, imputing the component with  $N_L + 1$  distinct resolution levels, denoted  $r = 0, 1, \dots, N_L$ ; these are the resolutions of the hierarchical breakpoint representation. Level  $r = N_L$  is the full resolution of the tile-component, while  $r = 0$  is the lowest resolution, also known as the tile-component's LL band. The *grid-points* associated with the resolution  $r$  of a breakpoint tile-component correspond to the integer-valued coordinates within the rectangle with upper left corner at  $(trx_o, try_o)$  and lower right hand corner at  $(trx_l - 1, try_l - 1)$ , where
+
+$$trx_o = \left\lfloor \frac{tcx_o}{2^{N_L - r}} \right\rfloor, \quad trx_l = \left\lfloor \frac{tcx_l}{2^{N_L - r}} \right\rfloor, \quad try_o = \left\lfloor \frac{tcy_o}{2^{N_L - r}} \right\rfloor, \quad try_l = \left\lfloor \frac{tcy_l}{2^{N_L - r}} \right\rfloor. \quad (3)$$
+
+Each resolution  $r$  has a corresponding depth  $d$  within the hierarchical representation. The highest resolution  $r = N_L$  corresponds to depth  $d = 1$ , while the resolution  $r = 0$  corresponds to depth  $d = N_L$ . Unlike other JPEG 2000 components, for which the LL band at resolution  $r = 0$  has the same depth  $d = N_L$  as resolution 1, the LL band of a breakpoint component has depth  $d = N_L + 1$ .
+
+## 7.2 Division of breakpoint resolutions into cells, arcs and the CL band
+
+Breakpoint components, their tile-components and their resolutions, do not have samples, but their grid-points may correspond to the sample locations of other components. Instead of samples, the coded information associated with a breakpoint component belongs to *arcs*.
+
+There are two fundamental arrangements for these arcs, known as QuadBPT and TriBPT, and two mirror-image variants for the TriBPT arrangement, known as TriBPT-LR and TriBPT-RL. All three arrangements are defined in terms of  $2 \times 2$  cells within each resolution of a breakpoint tile-component. To understand these arrangements, it is helpful to start by introducing the concept of a *2-span*, which consists of 9 grid-points. As shown in Figure 1, each arc runs between grid-points on the boundary of its 2-span. The central grid-point of a 2-span always has odd-valued coordinates in the resolution to which it belongs, while the corners of each 2-span have even-valued coordinates. Within any given resolution arcs have length 2, if we measure the length of diagonal arcs in the vertical direction only. This is equivalent to a length of  $2^d$  at the component's full resolution.
+
+![Figure 1: Arc arrangements within a single 2-span. The figure shows three diagrams: QuadBPT, TriBPT-LR, and TriBPT-RL. Each diagram shows a 2x2 grid of grid-points. In QuadBPT, all four grid-points are solid blue circles, and arrows connect them in a square pattern. In TriBPT-LR, the top-left and bottom-left grid-points are solid blue circles, and arrows connect them to the top-right and bottom-right grid-points, which are open circles. In TriBPT-RL, the top-left and top-right grid-points are solid blue circles, and arrows connect them to the bottom-left and bottom-right grid-points, which are open circles. The label T.816(23) is at the bottom right.](bd0b93e7a46ede276d0a3b79ac487bd9_img.jpg)
+
+Figure 1: Arc arrangements within a single 2-span. The figure shows three diagrams: QuadBPT, TriBPT-LR, and TriBPT-RL. Each diagram shows a 2x2 grid of grid-points. In QuadBPT, all four grid-points are solid blue circles, and arrows connect them in a square pattern. In TriBPT-LR, the top-left and bottom-left grid-points are solid blue circles, and arrows connect them to the top-right and bottom-right grid-points, which are open circles. In TriBPT-RL, the top-left and top-right grid-points are solid blue circles, and arrows connect them to the bottom-left and bottom-right grid-points, which are open circles. The label T.816(23) is at the bottom right.
+
+**Figure 1 – Arc arrangements within a single 2-span. A  $2 \times 2$  cell is shown here with solid grid-points. See Figure 2 for other geometric relationships between cells and 2-spans**
+
+Each 2-span is associated with a cell that contains only 4 unique grid-points. The grid-points of each resolution are partitioned into cells, such that the upper left corner of each cell has coordinates of the form  $(2c_x + z_x, 2c_y + z_y)$  and  $(z_x, z_y)$  corresponds to the code-block anchor point (CBAP) identified by bits 3 and 4 of the Scod parameter in the extended COD syntax specified in Rec. ITU-T T.801 | ISO/IEC 15444-2. The four possible combinations of CBAP coordinates,  $(z_x, z_y) = (0,0), (0,1), (1,0)$  and  $(1,1)$ , lead to four different cell partitions, that enable geometric manipulation (flipping and rotation) in the compressed domain. Figure 2 illustrates the four different relationships between cells and their 2-spans that result from the different anchor-points.
+
+![Figure 2: Cell-span geometry for each of the four possible code-block anchor points. The figure shows four 2x2 grids of grid-points. In each grid, the top-left grid-point is solid blue, and the other three are open circles. The grids are labeled with their respective anchor points: (z_x, z_y) = (0, 0), (z_x, z_y) = (1, 0), (z_x, z_y) = (0, 1), and (z_x, z_y) = (1, 1). The label T.816(23) is at the bottom right.](75f0cb39f1cd165dfe4a6aa6c4d9388d_img.jpg)
+
+Figure 2: Cell-span geometry for each of the four possible code-block anchor points. The figure shows four 2x2 grids of grid-points. In each grid, the top-left grid-point is solid blue, and the other three are open circles. The grids are labeled with their respective anchor points: (z\_x, z\_y) = (0, 0), (z\_x, z\_y) = (1, 0), (z\_x, z\_y) = (0, 1), and (z\_x, z\_y) = (1, 1). The label T.816(23) is at the bottom right.
+
+**Figure 2 – Cell-span geometry for each of the four possible code-block anchor points**
+
+NOTE 1 – The code-block anchor point is also the anchor point for the precinct partitions in JPEG 2000. This means that the cell partition always aligns with the precinct partition for the same resolution of a tile-component.
+
+The cells associated with a resolution of a breakpoint tile-component have coordinates  $(c_x, c_y)$ , covering the rectangle with upper left corner at  $(clx_o, cly_o)$  and lower right hand corner at  $(clx_l - 1, cly_l - 1)$ , where
+
+$$clx_o = \left\lceil \frac{trx_o - z_x}{2} \right\rceil, \quad clx_l = \left\lceil \frac{trx_l - z_x}{2} \right\rceil, \quad cly_o = \left\lceil \frac{try_o - z_y}{2} \right\rceil, \quad cly_l = \left\lceil \frac{try_l - z_y}{2} \right\rceil. \quad (4)$$
+
+That is, the resolution's cells consist of all  $2 \times 2$  elements from the partition that intersect with the resolution's region of support, regardless of whether the intersection involves 1, 2 or all 4 grid-points.
+
+Ignoring the LL band (resolution 0) for the moment, each other resolution  $r = 1, \dots, N_L$  of a breakpoint tile-component is assigned a single "detail band", similar to the LH, HL and HH sub-bands described in Rec. ITU-T T.800 | ISO/IEC 15444-1. This single detail band is denoted the CL band. Each element of a CL band is a  $2 \times 2$  cell (or a piece thereof, if the tile-component boundaries dissect the cell). The hierarchical representation of the breakpoint tile-component then consists of one LL band and  $N_L$  CL bands. Each CL band is  $clx_l - clx_o$  cells wide by  $cly_l - cly_o$  cells high, where these quantities are derived from the corresponding resolution's dimensions using Formula (4). The set of cells that constitute a CL band determine the properties of its code-blocks and precincts, as explained next.
+
+The dimensions of the LL band are expressed in grid-points rather than cells, and are identical to the dimensions of resolution 0, as derived from Formula (3) with  $r = 0$ . The LL band of a breakpoint tile-component is used to record breakpoints that would have been found in a CL band at depth  $N_L + 1$ , except that they are encoded with extra information to reveal whether or not the breakpoints should be considered to have been induced from even lower (uncoded) levels in the hierarchy. This is explained further in clause 9.
+
+NOTE 2 – Unlike regular image components, the LL bands of breakpoint tile-components are commonly devoid of any significant information – i.e., they need signal no breaks at all – but this might not always be the case.
+
+## 7.3 Division of breakpoint resolutions into precincts and code-blocks
+
+Like all JPEG 2000 components, each resolution of a breakpoint component is partitioned into precincts, and the associated bands are partitioned into code-blocks, such that each code-block belongs to exactly one precinct. The number of precincts which span a breakpoint tile-component at resolution  $r$  is given by
+
+$$precinctswide = \begin{cases} \left\lceil \frac{trx_l - z_x}{2^{PPx}} \right\rceil - \left\lceil \frac{trx_o - z_x}{2^{PPx}} \right\rceil & trx_l > trx_o, \\ 0 & trx_l = trx_o, \end{cases}$$
+
+$$precinctshigh = \begin{cases} \left\lceil \frac{try_l - z_y}{2^{PPy}} \right\rceil - \left\lceil \frac{try_o - z_y}{2^{PPy}} \right\rceil & try_l > try_o, \\ 0 & try_l = try_o, \end{cases}$$
+
+where PPx and PPy are signalled in COD and COC marker segments. These formulae for *precinctswide* and *precinctshigh* are the same as those found in Rec. ITU-T T.800 | ISO/IEC 15444-1, modified to account for the possibility of non-zero CBAP coordinates ( $z_x, z_y$ ). However, the values of PPx and PPy associated with breakpoint components shall be no smaller than 1. Moreover, for resolutions  $r > 0$ , the values of PPx and PPy for breakpoint components with TriBPT arrangements, shall be no smaller than 2. These constraints are summarized in Table 1.
+
+**Table 1 – Constraints on PPx and PPy precinct size parameters breakpoint components**
+
+| Breakpoint Arrangement | Resolution | PPx      | PPy      |
+|------------------------|------------|----------|----------|
+| QuadBPT                | $r = 0$    | $\geq 1$ | $\geq 1$ |
+| QuadBPT                | $r > 0$    | $\geq 1$ | $\geq 1$ |
+| TriLR or TriRL         | $r = 0$    | $\geq 1$ | $\geq 1$ |
+| TriLR or TriRL         | $r > 0$    | $\geq 2$ | $\geq 2$ |
+
+Each CL band is divided into code-blocks which are organized into precincts in exactly the same way as regular sub-bands, except that each precinct for a breakpoint tile component at resolution  $r > 0$  contains code-blocks from just the one CL band at that resolution, as opposed to HL, LH and HH sub-bands. Each nominal code-block at resolution  $r$  contains a rectangular array of cells that is  $2^{xcb'}$  cells wide and  $2^{ycb'}$  cells high, except at the boundaries of the tile-component, where code-blocks contain only those cells that intersect with the CL band region, as given by Formula (4). The code-block partition is anchored at the CBAP location ( $z_x, z_y$ ) introduced above (code-block anchor point), and consists of all code-blocks that have a non-empty intersection with the CL band region. This means that each CL code-block's cell indices occupy a rectangle whose upper-left corner has coordinates ( $bx_o, by_o$ ) and whose lower-right corner has coordinates ( $bx_l - 1, by_l - 1$ ), where
+
+$$bx_o = \max \{k_x 2^{xcb'}, clx_o\}, \quad bx_l = \min \{(k_x + 1) 2^{xcb'}, clx_l\},$$
+
+$$by_o = \max \{k_y 2^{ycb'}, cly_o\}, \quad by_l = \min \{(k_y + 1) 2^{ycb'}, cly_l\},$$
+
+( $k_x, k_y$ ) are the integer-valued code-block indices, and the set of code-blocks corresponds to all ( $k_x, k_y$ ) such that  $bx_l > bx_o$  and  $by_l > by_o$ . In the above,
+
+$$xcb' = \begin{cases} \min \{xcb, PPx - 1\} & r > 0 \\ \min \{xcb, PPx\} & r = 0 \end{cases} \quad ycb' = \begin{cases} \min \{ycb, PPy - 1\} & r > 0 \\ \min \{ycb, PPy\} & r = 0 \end{cases}, \quad (5)$$
+
+where xcb and ycb are signalled in COD and COC marker segments. These formulae are identical to the formulae for xcb' and ycb' in Rec. ITU-T T.800 | ISO/IEC 15444-1.
+
+NOTE 1 – The CL band region, given by Formula (4), can differ slightly from the regions associated with LH, HL or HH bands of a non-breakpoint tile-component at the same resolution, as given by determined in accordance with Rec. ITU-T T.800 | ISO/IEC 15444-1. It turns out that every precinct of a breakpoint tile-component is non-empty, in the sense that it contains at least one code-block that contains at least one cell. By contrast, it is possible for a precinct of a non-breakpoint tile-component to be empty, having no code-block from any LH, HL or HH sub-band, as explained in Rec. ITU-T T.800 | ISO/IEC 15444-1.
+
+The LL band of a breakpoint tile-component is also partitioned into code-blocks, where the partition is anchored at the CBAP location ( $z_x, z_y$ ), with code-blocks of width  $2^{xcb'}$  and height  $2^{ycb'}$ , where xcb' and ycb' are still found using Formula (5). However, LL code-blocks are measured in grid-points rather than cells, and code-blocks on the boundary of the tile-component contain only those grid-points that belong to the region associated with resolution 0, as given by Formula (3) with  $r = 0$ . Specifically, each LL code-block's grid-points have indices that lie within a rectangle whose upper-left corner has coordinates ( $Bx_o, By_o$ ) and whose lower-right corner has coordinates ( $Bx_l - 1, By_l - 1$ ), where
+
+$$Bx_o = \max \{z_x + k_x 2^{xcb'}, trx_o\}, \quad Bx_l = \min \{z_x + (k_x + 1) 2^{xcb'}, trx_l\},$$
+
+$$By_o = \max \{z_y + k_y 2^{ycb'}, try_o\}, \quad By_l = \min \{z_y + (k_y + 1) 2^{ycb'}, try_l\},$$
+
+( $k_x, k_y$ ) are the integer-valued code-block indices, and the set of LL code-blocks corresponds to all ( $k_x, k_y$ ) such that  $Bx_l > Bx_o$  and  $By_l > By_o$ .
+
+NOTE 2 – The number and sizes of LL code-blocks from a breakpoint tile-component are identical to those of an identically dimensioned non-breakpoint component with the same  $N_L$ , PPx, PPy, xcb and ycb parameters.
+
+Even though LL code-blocks of a breakpoint tile-component are dimensioned in terms of grid-points, their coded information is based on  $2 \times 2$  cells. Each LL code-block's grid-points are separately partitioned into cells, such that the upper-left corner of the top-left cell in the code-block, and the lower-right corner of the bottom-right cell in the code-block have coordinates
+
+$$(2LLx_o + z_x, 2LLy_o + z_y) \text{ and } (2LLx_l + z_x - 1, 2LLy_l + z_y - 1),$$
+
+respectively, where the inclusive lower and exclusive upper bounds on the block's cell coordinates are
+
+$$LLx_o = \left\lceil \frac{Bx_o - z_x}{2} \right\rceil, LLy_o = \left\lceil \frac{By_o - z_y}{2} \right\rceil, LLx_l = \left\lfloor \frac{Bx_l - z_x}{2} \right\rfloor \text{ and } LLy_l = \left\lfloor \frac{By_l - z_y}{2} \right\rfloor$$
+
+This means that the left half of each cell on the left boundary of the LL code-block lies outside the block if  $Bx_o \bmod 2 \neq z_x$ , a condition that can only occur for code-blocks on the left edge of the LL band. Similarly, the upper half of each cell on the top boundary of the code-block lies outside the block if  $By_o \bmod 2 \neq z_y$ , a condition that can only occur for code-blocks on the upper edge of the LL band. The right half of cells on the right edge of a code-block will lie outside the block if  $Bx_l \bmod 2 \neq z_x$ , while the lower half of cells on the bottom edge of a code-block will lie outside if  $By_l \bmod 2 \neq z_y$ ; these conditions can only occur for code-blocks on the right and bottom edges of the LL band, respectively. Regardless of whether all grid-points of a cell lie within the code-block to which it belongs, the block decoding procedures described in 9 regard all arcs associated with such grid-points as if they belong to the block.
+
+The number of cells that are found within any code-block is given by
+
+$$W_{\text{blk}} = bx_l - bx_o \text{ and } H_{\text{blk}} = by_l - by_o,$$
+
+where  $bx_o$ ,  $by_o$ ,  $bx_l$  and  $by_l$  become  $LLx_o$ ,  $LLy_o$ ,  $LLx_l$  and  $LLy_l$  for LL band code-blocks.
+
+## 7.4 Root and non-root arc breakpoint associations
+
+Breakpoints are associated with the grid-points of a  $2 \times 2$  cell, and serve to describe possible breaks along one of the arcs that span the corresponding 2-span.
+
+For the QuadBPT arrangement shown in Figure 1, there are four breakpoints per cell, as follows:
+
+- Horizontal *non-root arc* breakpoints are associated with each of a resolution's grid-points  $(p_x, p_y)$  for which  $p_x$  is odd and  $p_y$  is even, serving to describe possible breaks along the horizontal arc that is centred at  $(p_x, p_y)$ .
+- Vertical *non-root arc* breakpoints are associated with each of a resolution's grid-points  $(p_x, p_y)$  for which  $p_x$  is even and  $p_y$  is odd, serving to describe possible breaks along the vertical arc that is centred at  $(p_x, p_y)$ .
+- Horizontal *root arc* breakpoints and vertical *root arc* breakpoints are both associated with each of a resolution's grid-points  $(p_x, p_y)$  for which  $p_x$  and  $p_y$  are both odd, serving to describe possible breaks along the horizontal and vertical arcs that are centred at  $(p_x, p_y)$ .
+
+The term *non-root arc* here is used to describe an arc that shares an end-point with an arc of the same orientation at the next lower resolution (whether it exists or not); each non-root arc thus corresponds to one half of an arc at the lower resolution. By contrast, the *root arcs* are those that are not subsets of any arc at lower resolutions.
+
+For the TriBPT arrangements shown in Figure 1, there are three breakpoints per cell, as follows:
+
+- Horizontal arc breakpoints are associated with each of a resolution's grid-points  $(p_x, p_y)$  for which  $p_x$  is odd and  $p_y$  is even, serving to describe possible breaks along the horizontal arc that is centred at  $(p_x, p_y)$ .
+- Vertical arc breakpoints are associated with each of a resolution's grid-points  $(p_x, p_y)$  for which  $p_x$  is even and  $p_y$  is odd, serving to describe possible breaks along the vertical arc that is centred at  $(p_x, p_y)$ .
+- Diagonal arc breakpoints are associated with each of a resolution's grid-points  $(p_x, p_y)$  for which  $p_x$  and  $p_y$  are both odd, serving to describe possible breaks along the diagonal arc that is centred at  $(p_x, p_y)$ . These diagonal arcs run from the top-left to bottom-right corners of the 2-span in the TriBPT-LR case, and from the top-right to the bottom-left corners of the 2-span in the TriBPT-RL case.
+
+The TriBPT arrangements also have root and non-root arcs that can be observed across four 2-spans, known collectively as a *4-span*. The corners of a 4-span correspond to grid-points whose coordinates are divisible by 4. Figure 3 identifies the root and non-root arcs for all configurations.
+
+![Figure 3: Root arc (dotted lines) and non-root arcs (solid lines) for QuadBPT, TriBPT-LR, and TriBPT-RL arrangements.](ff7ce44f3fdd51bae7b231f34df07c6a_img.jpg)
+
+Figure 3 illustrates three different breakpoint arrangements: QuadBPT, TriBPT-LR, and TriBPT-RL. Each arrangement shows a grid of nodes (circles) and arcs (lines). Root arcs are represented by dotted lines, and non-root arcs are represented by solid lines. The nodes are labeled with coordinates (n, m) where n is the horizontal index and m is the vertical index. For QuadBPT, the horizontal indices are 2n, 2n+1, 2n+2 and the vertical indices are 2m, 2m+1, 2m+2. For TriBPT-LR and TriBPT-RL, the horizontal indices are 4n, 4n+2, 4n+4 and the vertical indices are 4m, 4m+2, 4m+4. The TriBPT-RL arrangement is also labeled with T.816(23).
+
+Figure 3: Root arc (dotted lines) and non-root arcs (solid lines) for QuadBPT, TriBPT-LR, and TriBPT-RL arrangements.
+
+Figure 3 – Root arc (dotted lines) and non-root arcs (solid lines)
+
+## 7.5 Breakpoint values and vertices
+
+Each breakpoint tile-component has an associated parameter  $F_B$  that controls the cardinality of the set of possible break locations on each arc. Each arc at resolution  $r$  has length 2 in its own resolution, which is equivalent to a length of  $2^d$  at the full resolution of the tile-component, where
+
+$$d = N_L + 1 - r,$$
+
+and each such arc has  $2^{d+F_B}$  possible break locations, of the form
+
+$$\text{breakposition} = (2k_b + 1)2^{-(F_B+1)} \quad (6)$$
+
+Here,  $k_b$  is an integer in the range  $0 \leq k_b < 2^{d+F_B}$  for an arc  $b$ . These possible break locations, indexed by  $k_b$ , are known here as *tick-points*. Note that diagonal arcs and their tick-points are projected onto the vertical axis for measurement purposes, so their lengths are still equal to  $2^d$ .
+
+The separation between tick-points, also known as the *tick-interval*, is  $2^{-F_B}$ . The smallest possible value for  $F_B$  is 0, in which case the tick-interval is 1 and arcs at the finest resolution ( $r = N_L$ ,  $d = 1$ ) can have breaks at only two possible locations, corresponding to the centres of the first and second halves of the arc. This is minimally sufficient to allow the breakpoints to be used in guiding the prediction processes of a breakpoint-dependent transform, as discussed in clause 8. Larger values of  $F_B$  allow breaks to be more precisely located along an arc. Figure 4 illustrates the tick-points resulting from a typical value of  $F_B = 2$ , for the case of the QuadBPT arrangement, at the finest resolution level.
+
+NOTE – The  $F_B$  parameter can be interpreted as the number of "fraction bits" associated with the break location index  $k_b$ .
+
+In addition to the break index  $k_b$ , each arc has a *break-type* value  $t_b$  in the range 0 to 3 and an integer *break-precision* value  $P_b$  that relates to the amount of information derived from the decoding of breakpoint code-blocks, from which breaks are inferred. For the TriBPT arrangement, breakpoints are also associated with an *extrapolation-qualifier*  $e_b$  that conveys information for performing extrapolation for arcs containing directly induced ( $t_b = 2$ ) or spatially induced ( $t_b = 1$ ) breaks. For all other break-type values the  $e_b$  parameter is irrelevant and can be ignored.
+
+In following discussions, for the QuadBPT arrangement the parameters of a breakpoint on an arc  $b$  are denoted by  $(t_b, P_b, k_b)$  while for the TriBPT arrangement the breakpoint parameters are given by  $(t_b, P_b, k_b, e_b)$ . Each of these parameters and the values that they can represent are discussed below.
+
+Break-type values are as follows:
+
+- $t_b = 3$  means that there is an explicitly coded break on the arc, known as a *vertex*; vertices are the significant values recovered from decoded breakpoint code-blocks. Vertex decoding is discussed in clause 9.
+- $t_b = 2$  means that there is a break on the arc that is directly induced from a vertex or another directly induced break at the next lower resolution; direct induction is possible only for non-root arc breakpoints. Direct induction is discussed in 10.2.
+- $t_b = 1$  means that there is a spatially induced break on the arc; spatial induction occurs when breaks are induced onto root-arcs based on breaks found in surrounding arcs at the same resolution, after which the condition is passed on recursively (through direct induction) to sub-arcs in finer resolutions. Spatial induction is discussed in 10.3 and 10.4.
+- $t_b = 0$  means that there is no break on the arc.
+
+The meaning of the break-precision value  $P_b$  depends upon the break-type  $t_b$ , as discussed next.
+
+![Figure 4: A diagram illustrating the mapping of vertices to tick-points on an arc. The arc is represented by a horizontal line with tick-points labeled k=0, k=1, k=2, ..., k=2^{d+F_B}-1. The arc length is 2^d (d=1). The diagram shows two vertices, v=0 and v=1, being mapped to tick-points. Vertex v=0 is mapped to k=0, and vertex v=1 is mapped to k=2^{d+F_B}-1. The mapping is shown by arrows from the vertices to the tick-points. The diagram also shows the mapping of vertices to tick-points using the VRT (Vertex Mapping Rule) and TPS (Tick-Point Selection) rules. The VRT rule is: VRT: (2V+1) 2^{d-P} < 0 < (2V+1) 2^{-P} < 1 (P=2). The TPS rule is: TPS: 0 < (2k+1) 2^{-(F_B+1)} < 2^d (F_B=2). The VRT rule is used to map vertices to tick-points, and the TPS rule is used to map tick-points to vertices. The diagram also shows the mapping of vertices to tick-points using the VMR (Vertex Mapping Rule) rule. The VMR rule is: VMR: 0 < (2k+1) 2^{-(F_B+1)} < 2^d (F_B=2). The diagram also shows the mapping of vertices to tick-points using the VRT rule. The VRT rule is: VRT: (2V+1) 2^{d-P} < 0 < (2V+1) 2^{-P} < 1 (P=2). The diagram also shows the mapping of vertices to tick-points using the TPS rule. The TPS rule is: TPS: 0 < (2k+1) 2^{-(F_B+1)} < 2^d (F_B=2). The diagram also shows the mapping of vertices to tick-points using the VMR rule. The VMR rule is: VMR: 0 < (2k+1) 2^{-(F_B+1)} < 2^d (F_B=2).](3ae74a33759ae31781f484406db4feed_img.jpg)
+
+Figure 4: A diagram illustrating the mapping of vertices to tick-points on an arc. The arc is represented by a horizontal line with tick-points labeled k=0, k=1, k=2, ..., k=2^{d+F\_B}-1. The arc length is 2^d (d=1). The diagram shows two vertices, v=0 and v=1, being mapped to tick-points. Vertex v=0 is mapped to k=0, and vertex v=1 is mapped to k=2^{d+F\_B}-1. The mapping is shown by arrows from the vertices to the tick-points. The diagram also shows the mapping of vertices to tick-points using the VRT (Vertex Mapping Rule) and TPS (Tick-Point Selection) rules. The VRT rule is: VRT: (2V+1) 2^{d-P} < 0 < (2V+1) 2^{-P} < 1 (P=2). The TPS rule is: TPS: 0 < (2k+1) 2^{-(F\_B+1)} < 2^d (F\_B=2). The VRT rule is used to map vertices to tick-points, and the TPS rule is used to map tick-points to vertices. The diagram also shows the mapping of vertices to tick-points using the VMR (Vertex Mapping Rule) rule. The VMR rule is: VMR: 0 < (2k+1) 2^{-(F\_B+1)} < 2^d (F\_B=2). The diagram also shows the mapping of vertices to tick-points using the VRT rule. The VRT rule is: VRT: (2V+1) 2^{d-P} < 0 < (2V+1) 2^{-P} < 1 (P=2). The diagram also shows the mapping of vertices to tick-points using the TPS rule. The TPS rule is: TPS: 0 < (2k+1) 2^{-(F\_B+1)} < 2^d (F\_B=2). The diagram also shows the mapping of vertices to tick-points using the VMR rule. The VMR rule is: VMR: 0 < (2k+1) 2^{-(F\_B+1)} < 2^d (F\_B=2).
+
+T.816(23)
+
+VRT vertex
+
+TPS tick-points
+
+VMR vertex mapping rule of mapping vertex to nearest tick-point "away from arc centre"
+
+NOTE – This figure depicts the case where  $d = 1$ ,  $P = \text{precision bits} = 2$  and  $F_B = 2$  with arc length given by  $2^d$ .
+
+**Figure 4 – Possible break locations (tick-points) at the finest resolution, with  $F_B = 2$ , shown for the QuadBPT case. Also shows the mapping of vertices with precision  $P_b$  to tick-points**
+
+**Vertex Precision:** For vertices ( $t_b = 3$ ), the break-precision  $P_b$  shall satisfy
+
+$$1 \leq P_b - 1 \leq d + F_B \quad (7)$$
+
+where  $P_b - 1$  is the number of bits of the vertex  $V_b$  that were actually decoded. The value  $(2V_b + 1)$  is a  $P_b$ -bit unsigned integer, and the relationship between the tick-point  $k_b$  and the decoded vertex value  $V_b$  is as follows:
+
+$$k_b = (2V_b + 1)2^{d+F_B-P_b} + \begin{cases} 0, & \text{if } (2V_b + 1)2^{-P_b} > \frac{1}{2} \\ -1, & \text{if } (2V_b + 1)2^{-P_b} < \frac{1}{2} \end{cases} \quad (8)$$
+
+Figure 4 illustrates this mapping of the  $(P_b - 1)$  bit vertex value  $V_b$  to tick-point  $k_b$ . The quantity  $(2V_b + 1)2^{-P_b} \in (0,1)$  can be interpreted as a relative vertex position. As seen in the figure, the role of the offset on the right hand side of Formula (8) is to round this relative position outwards (away from the centre of the arc at relative position  $\frac{1}{2}$ ) to the nearest available tick-point.
+
+**Induced break precision:** Directly induced breaks ( $t_b = 2$ ) are obtained on non-root arcs, from vertices or other directly induced breaks at the next lower resolution, by decrementing  $P_b$  and discarding the most significant bit of  $k_b$ . Specifically, using the term "parent" to identify the corresponding arc in the next lower resolution,
+
+$$P_{\text{induced}} = \max \{1, P_{\text{parent}} - 1\}, k_{\text{induced}} = k_{\text{parent}} \bmod 2^{d+F_B-1} \quad (9)$$
+
+Spatially induced breaks ( $t_b = 1$ ) are derived from breaks on surrounding arcs at the same resolution, and their precision is the smallest value of  $P_b$  associated with those surrounding arcs whose breaks are involved in the induction.
+
+Induced breaks with  $P_b = 1$  are said to be *ambivalent*, since insufficient information is preserved to determine whether the break occurs in the first or second half of the arc. Both directly and spatially induced breaks can be ambivalent.
+
+The special value  $P_b = 0$  is used to identify *indefinite* breaks; these are induced breaks whose existence is uncertain because one or more of the arcs used in the induction process has break-precision  $P_b \leq 1$  that is too small to determine whether a break should exist. Both directly and spatially induced breaks can be indefinite.
+
+**No-break precision:** When  $t_b = 0$ , meaning that there is no break on an arc, the value of  $k_b$  is meaningless, but the parameter  $P_b$  can be either 0 or 1. The combination  $t_b = 0, P_b = 1$  means that the arc contains an *induction block*. Induction blocks prevent any break from being induced on the arc. Induction blocks are derived from decoding breakpoint code-blocks.
+
+The extrapolation-qualifier  $e_b$  is comprised of two binary flags  $e_{b,0}$  and  $e_{b,1}$ , such that  $e_b = (e_{b,1}, e_{b,0})$ . A break divides an arc into two parts and the binary value of  $e_{b,0}$  conveys information required for performing extrapolation for the first
+
+part while  $e_{b,1}$  corresponds to information for the second part of the arc. These binary flags have specific and distinct meaning for directly induced ( $t_b = 2$ ) and spatially induced ( $t_b = 1$ ) breaks for the TriBPT arrangement as detailed below.
+
+For a directly induced break,  $e_{b,0} = \text{GRAD1\_FLAG}_{\text{induced}}$  and  $e_{b,1} = \text{GRAD2\_FLAG}_{\text{induced}}$ . The predict step for an arc containing a directly induced break is conditional on these flags as described in 8.2.4. The values for  $\text{GRAD1\_FLAG}_{\text{induced}}$  and  $\text{GRAD2\_FLAG}_{\text{induced}}$  can be derived during the breakpoint synthesis stage and this is detailed in 10.2.2.
+
+If an arc contains a spatially induced break, then  $e_{b,0} = \text{DRCTN1\_FLAG}_{\text{spatial}}$  and  $e_{b,1} = \text{DRCTN2\_FLAG}_{\text{spatial}}$ . As detailed in 8.2.5, these binary flags signify a direction of search for an external gradient and are utilized in the predict step for arcs containing spatially induced breaks. The values for  $\text{DRCTN1\_FLAG}_{\text{spatial}}$  and  $\text{DRCTN2\_FLAG}_{\text{spatial}}$  can be determined from the 4-span triangle and inducing line geometry as explained in 10.4.4. For both flags a value of 1 indicates a search in the increasing x-coordinate direction for horizontal arcs and in the increasing y-coordinate direction for vertical and diagonal arcs. Conversely, a value of 0 indicates a search in the decreasing x-coordinate direction for horizontal arcs and in the decreasing y-coordinate direction for vertical and diagonal arcs.
+
+# 8 Breakpoint-dependent spatial wavelet transformation
+
+## 8.1 Overview
+
+To perform breakpoint-dependent inverse discrete wavelet transformation (BD-IDWT), this Recommendation | International Standard uses the synthesized breakpoints, as described in clause 10, to adapt a two-dimensional reconstruction of sub-band samples obtained by processing the codestream in accordance with Rec. ITU-T T.800 | ISO/IEC 15444-1 together with any additional signalled capability.
+
+The BD-IDWT is performed in stages for a given tile  $t$  of a non-breakpoint component with index  $c$ , progressing from coarse to fine resolutions  $r = 1, 2, \dots, N_L$ . The BD-IDWT uses spatial sub-band samples found within that tile-component, that are obtained by processing the codestream in accordance with Rec. ITU-T T.800 | ISO/IEC 15444-1, together with any additional signalled capability.
+
+The BD-IDWT also uses breakpoint data from the same tile  $t$  of a separate breakpoint component with index  $D_c$ , where the value  $D_c$  is communicated via the SEcod field specified in Annex A.
+
+Each stage  $r$  utilizes the four spatial sub-bands  $LL_{c,r}, HL_{c,r}, LH_{c,r}, HH_{c,r}$  that belong to resolution  $r$  of the non-breakpoint tile-component indexed by  $c$ , together with a corresponding breakpoint band  $LL_{D_c,r}$  which contains all breakpoint information at resolution  $r$  for the designated breakpoint tile-component indexed by  $D_c$ . The breakpoint data provided by  $LL_{D_c,r}$  corresponds to the (partially) reconstructed breakpoints that appear at the same resolution  $r$  as determined using the reconstruction procedure in clause 10. Stage  $r$  uses this information to synthesize a sub-band  $LL_{c,(r+1)}$ , for use in the next stage, if any. The iterative procedure is illustrated in
+
+$LL_{D_c,i}$  denotes the breakpoint LL band for resolution  $r=i$ .
+
+Figure 5 where the output of the final stage  $LL_{c,(N_L+1)}$  constitutes the decoded samples of the tile-component  $c$ .
+
+![Figure 5: Stages of the breakpoint dependent inverse discrete wavelet transform. The diagram shows a sequence of stages (Stage 1, Stage 2, ..., Stage N_L) processing inputs. Stage 1 takes inputs LL_{c,1}, HL_{c,1}, LH_{c,1}, HH_{c,1} and LL_{D_c,1} to produce LL_{c,2}. Stage 2 takes inputs HL_{c,2}, LH_{c,2}, HH_{c,2} and LL_{D_c,2} to produce LL_{c,3}. This pattern continues until Stage N_L, which takes inputs HL_{c,N_L}, LH_{c,N_L}, HH_{c,N_L} and LL_{D_c,N_L} to produce the final output LL_{c,(N_L+1)}. The diagram is labeled T.816(23).](cd141897aa368dbbaa398ace230cdd85_img.jpg)
+
+Figure 5: Stages of the breakpoint dependent inverse discrete wavelet transform. The diagram shows a sequence of stages (Stage 1, Stage 2, ..., Stage N\_L) processing inputs. Stage 1 takes inputs LL\_{c,1}, HL\_{c,1}, LH\_{c,1}, HH\_{c,1} and LL\_{D\_c,1} to produce LL\_{c,2}. Stage 2 takes inputs HL\_{c,2}, LH\_{c,2}, HH\_{c,2} and LL\_{D\_c,2} to produce LL\_{c,3}. This pattern continues until Stage N\_L, which takes inputs HL\_{c,N\_L}, LH\_{c,N\_L}, HH\_{c,N\_L} and LL\_{D\_c,N\_L} to produce the final output LL\_{c,(N\_L+1)}. The diagram is labeled T.816(23).
+
+$LL_{D_c,i}$  denotes the breakpoint LL band for resolution  $r=i$ .
+
+**Figure 5 – Stages of the breakpoint dependent inverse discrete wavelet transform**
+
+In the simplest case, where both components have the same number of decomposition levels  $N_L$  and identical sampling factors  $\text{XRsiz}^i$  and  $\text{YRsiz}^i$  reconstructed breakpoint data for resolution  $r$  is combined directly with the four spatial sub-bands  $LL_{c,r}, HL_{c,r}, LH_{c,r}, HH_{c,r}$  to perform the reconstruction at stage  $r = 1, 2, \dots, N_L$ .
+
+If the breakpoint component and breakpoint-dependent component have different sampling factors  $XR_{siz}^i$  and  $YR_{siz}^i$ , the transformation process is not well defined. Some decoders might be capable of producing meaningful results when this happens, but this Recommendation | International Standard does not define the behaviour under such circumstances.
+
+If the breakpoint component provides  $\Delta_L$  more decomposition levels  $N_L$  than the breakpoint-dependent component, the transformation processes described here shall be applied after renumbering the resolutions of the breakpoint component so that original resolution  $r$  is interpreted as resolution  $r - \Delta_L$ . This effectively discards the unnecessary lower resolutions of breakpoint information.
+
+If the breakpoint component provides only  $N_L - 1$  decomposition levels, for the breakpoint-dependent component's  $N_L$  decomposition levels, the transformation processes described here shall be performed after renumbering the resolutions of the breakpoint component so that original resolution  $r$  is interpreted as resolution  $r + 1$ . This leaves the breakpoint component's LL band at resolution 0 providing the breakpoint data for the first stage of the transform at  $r = 1$ . If the breakpoint component provides even fewer decomposition levels, the transformation process is not defined by this Recommendation | International Standard.
+
+Each stage of the BD-IDWT is performed in two steps. First the four spatial sub-bands  $LL_{c,r}, HL_{c,r}, LH_{c,r}, HH_{c,r}$  are subjected to a mapping procedure 2D\_GP\_MAPPING that produces a single interleaved output band  $I_{c,r}$ . A breakpoint dependent 2D sub-band reconstruction procedure BD\_2D\_SR is then applied to  $I_{c,r}$  that depends on the corresponding breakpoint band  $LL_{D_c,r}$ .
+
+## 8.2 TriBPT-dependent irreversible transforms
+
+### 8.2.1 Introduction
+
+For the TriBPT case, the 2D\_GP\_MAPPING procedure maps the spatial sub-bands  $LL_{c,r}, HL_{c,r}, LH_{c,r}, HH_{c,r}$  to corresponding grid-point locations to form an interleaved band  $I_{c,r}$  such that  $I_{c,r} = 2D\_GP\_MAPPING(LL_{c,r}, HL_{c,r}, LH_{c,r}, HH_{c,r}, trx_o, trx_l, try_o, try_l)$  where  $(trx_o, try_o)$  specifies the upper left corner and  $(trx_l - 1, try_l - 1)$  the lower right corner of the rectangular grid-point region at resolution  $r$  that corresponds to  $I_{c,r}$ . The mapping of sub-band samples to grid-point locations for a given resolution  $r$  is illustrated in Figure 6; while the specific example shown relates to the TriBPT-LR case, the mapping remains identical for TriBPT-RL.
+
+NOTE – As shown in Figure 6, the grid-point mapping procedure associates the samples of the  $HL_{c,r}, LH_{c,r}, HH_{c,r}$  spatial sub-bands at the same locations as horizontal, vertical and diagonal arcs from the breakpoint component  $D_c$ , respectively.
+
+In the description that follows, it is convenient to identify different triangular elements within a 4-span (see Figure 3) by means of two variables,  $s_{LR}$  and  $s_{TB}$ . The first variable distinguishes between the mirror-image geometries TriBPT-LR and TriBPT-RL, with  $s_{LR} = 1$  for the TriBPT-LR arrangement and  $s_{LR} = -1$  for the TriBPT-RL arrangement. The second variable distinguishes between the upper and lower triangles within the 4-span, denoted TOP\_Tri and BOT\_Tri, with  $s_{TB} = 1$  and  $s_{TB} = -1$ , respectively.
+
+This clause defines the TriBPT-dependent irreversible transforms. The reversible version of these transforms are defined in 8.3.
+
+The interleaved band  $I_{c,r}$  produced by the 2D\_GP\_MAPPING procedure, is subject to 2D filtering BD\_2D\_SR, which consists of two lifting steps. The update step is applied first, modifying sub-band samples at grid-points  $(p_x, p_y)$  that are (even, even), based on sub-band samples and breakpoint values at connected neighbouring grid-points with (even, odd), (odd, even) and (odd, odd) locations. The update step is implemented by making the following assignment for each (even, even) location  $(2n, 2m)$  of  $I_{c,r}$ .
+
+$$I_{c,r}(2n, 2m) = I_{c,r}(2n, 2m) - \sum_{(\delta_n, \delta_m) \in \mathcal{N}_U} U(I_{c,r}, LL_{D_c,r}, 2n + \delta_n, 2m + \delta_m) \quad (10)$$
+
+Here,  $\mathcal{N}_U = \{(1, 0), (0, 1), (s_{LR}, 1), (-1, 0), (0, -1), (-s_{LR}, -1)\}$  identifies the update neighbourhood, and the update function  $U$  is given by
+
+$$U(I_{c,r}, LL_{D_c,r}, p_x, p_y) = \begin{cases} \mu * I_{c,r}(p_x, p_y), & \text{if } t_b(p_x, p_y) = 0 \\ 0, & \text{otherwise} \end{cases} \quad (11)$$
+
+where  $\mu = \frac{1}{8}$  and  $t_b(p_x, p_y)$  is the arc break-type found from  $LL_{D_c,r}(p_x, p_y)$ . As defined in clause 7,  $t_b = 0$  means that there is no break on the arc. Figure 7 shows the operation of the update step for the TriBPT-LR arrangement, providing examples with no breakpoints and when breakpoints are present on neighbouring arcs.
+
+After the update step, the (even, even) indexed sub-band samples located at end points of arcs at resolution  $r$  are utilized in performing the second (predict) lifting step. The predict step is implemented by making the following assignment for each (even, odd), (odd, even) and (odd, odd) location within  $I_{c,r}$ :
+
+$$I_{c,r}(\mathbf{p}) = I_{c,r}(\mathbf{p}) + P(I_{c,r}, LL_{D_{c,r}}, \mathbf{p}), \text{ where } \mathbf{p} = (p_x, p_y) \text{ and } p_x, p_y \text{ are not both even.} \quad (12)$$
+
+For a root or non-root arc centred at location  $\mathbf{p} = (p_x, p_y)$ , the predict function  $P()$  is dependent on the corresponding break-type  $t_b(p_x, p_y)$ , as well as the location of the break  $k_b(p_x, p_y)$ , as given by  $LL_{D_{c,r}}(p_x, p_y)$ . There are in total five distinct cases that give rise to specific breakpoint dependent predict functions, as detailed in 8.2.2 through 8.2.5.
+
+![Figure 6: Interleaving of sub-band coefficients to a triangular grid for a given resolution r. The diagram shows a triangular grid of nodes. The top row has nodes labeled 2n and 2n+2. The middle row has nodes labeled 2m and 2m+1. The bottom row has nodes labeled 2m+1 and 2m+2. Arrows indicate the flow of coefficients between nodes. Labels include LL_{c,r}(n, m), HL_{c,r}(n, m), LH_{c,r}(n, m), and HH_{c,r}(n, m). The diagram is labeled TriBPT-LR and T.816(23).](e180f2b5fcbe8001554a7c0677cd3f82_img.jpg)
+
+Figure 6: Interleaving of sub-band coefficients to a triangular grid for a given resolution r. The diagram shows a triangular grid of nodes. The top row has nodes labeled 2n and 2n+2. The middle row has nodes labeled 2m and 2m+1. The bottom row has nodes labeled 2m+1 and 2m+2. Arrows indicate the flow of coefficients between nodes. Labels include LL\_{c,r}(n, m), HL\_{c,r}(n, m), LH\_{c,r}(n, m), and HH\_{c,r}(n, m). The diagram is labeled TriBPT-LR and T.816(23).
+
+Figure 6 – Interleaving of sub-band coefficients to a triangular grid for a given resolution  $r$
+
+![Figure 7: Update step examples for TriBPT-LR arrangement. (a) Update step in the absence of breakpoints: shows a triangular grid with nodes labeled 2n, 2n+1, 2n+2, 2m, 2m+1, 2m+2. Arrows indicate the flow of coefficients. (b) Update step in the presence of breakpoints: shows the same grid with a breakpoint location (BRL) marked with a red 'X' at the center node. Arrows indicate the flow of coefficients. The diagram is labeled T.816(23).](7d3d5fb5d09c0cd35a9d637be241651e_img.jpg)
+
+Figure 7: Update step examples for TriBPT-LR arrangement. (a) Update step in the absence of breakpoints: shows a triangular grid with nodes labeled 2n, 2n+1, 2n+2, 2m, 2m+1, 2m+2. Arrows indicate the flow of coefficients. (b) Update step in the presence of breakpoints: shows the same grid with a breakpoint location (BRL) marked with a red 'X' at the center node. Arrows indicate the flow of coefficients. The diagram is labeled T.816(23).
+
+a) Update step in the absence of breakpoints
+
+b) Update step in the presence of breakpoints
+
+BRL breakpoint location
+
+Figure 7 – Update step examples for TriBPT-LR arrangement
+
+![Figure 8: Predict step examples for a horizontal arc. (a) Predict step in the absence of breakpoints: shows a horizontal arc with nodes labeled 2n, 2n+1, 2n+2. Arrows indicate the flow of coefficients. (b) Predict step in the presence of a breakpoint: shows the same arc with a breakpoint location (BRL) marked with a red 'X' at the center node. Arrows indicate the flow of coefficients. The diagram is labeled T.816(23).](04dc3838022e96d8d5548bb1b777b38c_img.jpg)
+
+Figure 8: Predict step examples for a horizontal arc. (a) Predict step in the absence of breakpoints: shows a horizontal arc with nodes labeled 2n, 2n+1, 2n+2. Arrows indicate the flow of coefficients. (b) Predict step in the presence of a breakpoint: shows the same arc with a breakpoint location (BRL) marked with a red 'X' at the center node. Arrows indicate the flow of coefficients. The diagram is labeled T.816(23).
+
+a) Predict step in the absence of breakpoints
+
+b) Predict step in the presence of a breakpoint
+
+BRL breakpoint location
+
+Figure 8 – Predict step examples for a horizontal arc
+
+### 8.2.2 Arcs with $t_b = 0$
+
+For arcs without any breaks ( $t_b(\mathbf{p}) = 0$ ), the predict function is given by
+
+$$P(I_{c,r}, LL_{D_{c,r}}, \mathbf{p}) = \frac{1}{2}(I_{c,r}(\mathbf{p}^A) + I_{c,r}(\mathbf{p}^B)) \quad (13)$$
+
+where the prediction source locations  $\mathbf{p}^A$  and  $\mathbf{p}^B$  are given by
+
+$$[\mathbf{p}^A, \mathbf{p}^B] = \begin{cases} [(2n, 2m), (2n + 2, 2m)] & \text{if } \mathbf{p} = (2n + 1, 2m) \\ [(2n, 2m), (2n, 2m + 2)] & \text{if } \mathbf{p} = (2n, 2m + 1) \\ [(2n, 2m), (2n + 2s_{LR}, 2m + 2)] & \text{if } \mathbf{p} = (2n + s_{LR}, 2m + 1) \end{cases} \quad (14)$$
+
+An example involving a horizontal arc is shown in Figure 8 (left).
+
+### 8.2.3 Arcs with $t_b = 3$
+
+For arcs containing a vertex ( $t_b(\mathbf{p}) = 3$ ), the predict function is given by
+
+$$P(I_{c,r}, LL_{D_{c,r}}, \mathbf{p}) = \begin{cases} I_{c,r}(\mathbf{p}^A) & k_b(\mathbf{p}) > 2^{d+F_B-1} \\ I_{c,r}(\mathbf{p}^B) & k_b(\mathbf{p}) < 2^{d+F_B-1} \end{cases} \quad (15)$$
+
+where the prediction source locations  $\mathbf{p}^A$  and  $\mathbf{p}^B$  are given by Formula (14). An example involving a horizontal arc is shown in Figure 8 (right).
+
+### 8.2.4 Arcs with $t_b = 2$
+
+For arcs containing a directly induced break ( $t_b(\mathbf{p}) = 2$ ), the predict function is given by
+
+$$P(I_{c,r}, LL_{D_{c,r}}, \mathbf{p}) = \begin{cases} I_{c,r}(\mathbf{p}^A) + G_b(\mathbf{p}, 2\mathbf{p}^A - \mathbf{p}) & k_b(\mathbf{p}) > 2^{d+F_B-1} \\ I_{c,r}(\mathbf{p}^B) + G_b(\mathbf{p}, 2\mathbf{p}^B - \mathbf{p}) & k_b(\mathbf{p}) < 2^{d+F_B-1} \end{cases} \quad (16)$$
+
+Where the prediction source locations  $\mathbf{p}^A$  and  $\mathbf{p}^B$  are given by Formula (14) and  $G_b(\mathbf{p}, \mathbf{p}^{nbr})$  refers to a gradient value
+
+$$G_b(\mathbf{p}, \mathbf{p}^{nbr}) = \begin{cases} \frac{1}{2} \left[ I_{c,r} \left( \mathbf{p}^{nbr} + \frac{\mathbf{p} - \mathbf{p}^{nbr}}{2} \right) - I_{c,r} \left( \mathbf{p}^{nbr} - \frac{\mathbf{p} - \mathbf{p}^{nbr}}{2} \right) \right] & \text{if } \text{SMOOTH}(\mathbf{p}, \mathbf{p}^{nbr}) \\ 0 & \text{otherwise} \end{cases}$$
+
+Here,  $\mathbf{p}^{nbr}$  denotes the location of a neighbouring arc within  $LL_{D_{c,r}}$ , to the one at location  $\mathbf{p}$ , and the boolean function  $\text{SMOOTH}(\mathbf{p}, \mathbf{p}^{nbr})$  returns TRUE only if the following three conditions are satisfied:
+
+- $\mathbf{p}^{nbr}$  belongs to  $LL_{D_{c,r}}$  and
+- $t_b(\mathbf{p}^{nbr}) = 0$  and
+- $\text{GRADX\_FLAG}_{induced}(\mathbf{p}) = 1$
+
+where  $\text{GRADX\_FLAG}_{induced}$  for the arc at  $\mathbf{p}$  is defined as shown below.
+
+$$\text{GRADX\_FLAG}_{induced}(\mathbf{p}) = \begin{cases} \text{GRAD1\_FLAG}_{induced} & k_b(\mathbf{p}) > 2^{d+F_B-1} \\ \text{GRAD2\_FLAG}_{induced} & k_b(\mathbf{p}) < 2^{d+F_B-1} \end{cases}$$
+
+The values of the binary flags  $\text{GRAD1\_FLAG}_{induced}$  and  $\text{GRAD2\_FLAG}_{induced}$  are defined by the extrapolation-qualifier  $e_b$  for the arc as specified in 7.5.
+
+An example of direct induction is shown in Figure 9. The example shows a vertex at resolution  $r^{anc}$ , directly inducing a break on the horizontal arc centred at  $\mathbf{p} = (2n + 1, 2m)$  in resolution  $r$ . The neighbouring arc  $nbr$  at location  $\mathbf{p}^{nbr} = (2n + 3, 2m)$  and ancestor arc ( $anc$ ) are also shown. The extrapolation-qualifier for the second half of the current arc  $\text{GRAD2\_FLAG}_{induced} = 1$  to indicate that the neighbouring arc  $nbr$  is a sub-arc of the ancestor arc  $anc$ . Since  $nbr$  is free from breaks and a sub-arc of  $anc$ , the samples at both endpoints of  $nbr$  are used to determine the gradient value  $G_b(\mathbf{p}, \mathbf{p}^{nbr})$ . The extrapolation-qualifier for the first half of the current arc  $\text{GRAD1\_FLAG}_{induced} = 0$ .
+
+NOTE – As explained in clause 7,  $t_b(\mathbf{p}) = 2$  means that the arc at  $\mathbf{p}$  contains a break that is recursively induced from a decoded vertex on some ancestor arc at a coarser resolution  $r^{anc} < r$ . The predict function allows for linear extrapolation within the span of this ancestor arc.
+
+![Figure 9: Example of direct induction of a breakpoint. The diagram shows three horizontal arcs. The top arc is labeled 'ANC' and has a vertex 'r^{anc} = r - 2'. A dashed arrow labeled 'VRT' points from a point on this arc down to a point on the middle arc. The middle arc has a point labeled 'r - 1'. A dashed arrow labeled 'DIB' points from the 'VRT' point down to a point on the bottom arc. The bottom arc has several points labeled with coordinates: (2n, 2m), (2n + 2, 2m), (2n + 4, 2m), p = (2n + 1, 2m), and p^{nbr} = (2n + 3, 2m). A bracket labeled 'NBR' spans the points (2n + 2, 2m) to (2n + 4, 2m).](73b5cce955ba9415a98791db7b0080ad_img.jpg)
+
+ANC
+
+VRT
+
+DIB
+
+NBR
+
+$r^{anc} = r - 2$
+
+$r - 1$
+
+$(2n, 2m)$   $(2n + 2, 2m)$   $(2n + 4, 2m)$
+
+$p = (2n + 1, 2m)$   $p^{nbr} = (2n + 3, 2m)$
+
+ANC ancestor arc (*anc*)
+
+VRT vertex
+
+DIB directly induced breaks
+
+NBR neighbouring arc (*nbr*)
+
+T.816(23)
+
+Figure 9: Example of direct induction of a breakpoint. The diagram shows three horizontal arcs. The top arc is labeled 'ANC' and has a vertex 'r^{anc} = r - 2'. A dashed arrow labeled 'VRT' points from a point on this arc down to a point on the middle arc. The middle arc has a point labeled 'r - 1'. A dashed arrow labeled 'DIB' points from the 'VRT' point down to a point on the bottom arc. The bottom arc has several points labeled with coordinates: (2n, 2m), (2n + 2, 2m), (2n + 4, 2m), p = (2n + 1, 2m), and p^{nbr} = (2n + 3, 2m). A bracket labeled 'NBR' spans the points (2n + 2, 2m) to (2n + 4, 2m).
+
+Figure 9 – Example of direct induction of a breakpoint
+
+Figure 10 illustrates examples of spatially induced breaks on root arcs by source breaks on non-root arcs for the TriBPT-LR arrangement. The base-arc and base-grid-point along with the configuration of the corresponding wedge area for each case is shown.
+
+![Figure 10: Example illustrating spatially induced breaks. The diagram is divided into two parts, a) and b). Part a) shows a vertical root arc with a base-intersection-point 'p' and a base-grid-point 'p_{base}'. A break-inducing-line 'BIL' passes through 'p'. Source breaks 'SBR' are shown on a non-root arc. A wedge area 'WDA' is defined. Part b) shows a horizontal root arc with a base-intersection-point 'p' and a base-grid-point 'p_{base}'. A break-inducing-line 'BIL' passes through 'p'. Source breaks 'SBR' are shown on a non-root arc. A wedge area 'WDA' is defined. Both parts show a base-line 'BLN' and a base-intersection-point 'p'.](4b87467ad9642943235f48f7d4b59449_img.jpg)
+
+BIP
+
+BGP
+
+BLN
+
+BIL
+
+SBR
+
+WDA
+
+a) Example illustrating spatially induced break on vertical root arc
+
+b) Example illustrating spatially induced break on horizontal root arc
+
+T.816(23)
+
+Figure 10: Example illustrating spatially induced breaks. The diagram is divided into two parts, a) and b). Part a) shows a vertical root arc with a base-intersection-point 'p' and a base-grid-point 'p\_{base}'. A break-inducing-line 'BIL' passes through 'p'. Source breaks 'SBR' are shown on a non-root arc. A wedge area 'WDA' is defined. Part b) shows a horizontal root arc with a base-intersection-point 'p' and a base-grid-point 'p\_{base}'. A break-inducing-line 'BIL' passes through 'p'. Source breaks 'SBR' are shown on a non-root arc. A wedge area 'WDA' is defined. Both parts show a base-line 'BLN' and a base-intersection-point 'p'.
+
+|     |                         |     |                 |     |               |
+|-----|-------------------------|-----|-----------------|-----|---------------|
+| BIP | base-intersection-point | BGP | base-grid-point | BLN | base-line     |
+| BIL | break-inducing-line     | WDA | wedge area      | SBR | source breaks |
+
+Figure 10 – Example illustrating spatially induced breaks
+
+Figure 11 gives an example of spatial induction for a non-root arc.
+
+![Figure 11: Spatial induction for a non-root arc. (a) Example of a non-root arc with a spatially induced break at resolution r. (b) Source breaks and inducing line for parent-4-span at resolution r^{rt} = r - 1.](5500ab73cf84ccc0055eecf28889b4db_img.jpg)
+
+a) Example of a non-root arc with a spatially induced break at resolution  $r$
+
+b) Source breaks and inducing line for parent-4-span at resolution  $r^{rt} = r - 1$
+
+Figure 11 consists of two diagrams, (a) and (b), illustrating spatial induction for a non-root arc. Diagram (a) shows a triangular grid structure with a blue line representing a non-root arc (NRA). A point  $p^{base}$  is marked as a base-grid-point (BGP). A green square indicates a spatially induced break (SPB). Diagram (b) shows a larger context with a red break-inducing-line (BIL) intersecting the arc at a base-intersection-point (BIP) marked with a red 'X'. A source break (SBR) is also indicated. A wedge area (WDA) is defined by the intersection of the BIL and the base-line (BLN). Both diagrams include technical labels like T.816(23).
+
+Figure 11: Spatial induction for a non-root arc. (a) Example of a non-root arc with a spatially induced break at resolution r. (b) Source breaks and inducing line for parent-4-span at resolution r^{rt} = r - 1.
+
+|     |                         |     |                         |     |              |
+|-----|-------------------------|-----|-------------------------|-----|--------------|
+| BGP | base-grid-point         | SPB | spatially induced break | NRA | non-root arc |
+| BIP | base-intersection-point | BLN | base-line               | WDA | wedge area   |
+| BIL | break-inducing-line     | SBR | source breaks           |     |              |
+
+**Figure 11 – Example of a spatially induced breakpoint on a non-root arc for the TriBPT-LR arrangement**
+
+Figure 12 identifies the corresponding base-arc for the spatial induction cases illustrated in Figure 10.
+
+![Diagram a) showing a vertical root arc with binary flags ORN = Horizontal and DRCTNX_FLAG_induced = 1. The diagram includes a horizontal dashed line (BLN), a red diagonal line (BIL), and a green arc (BSA). Vectors G^bsa and G^wdg are shown as blue arrows. A black 'X' marks the BIP point.](a848a8de7c2614546db51319bd55328f_img.jpg)
+
+a) Vertical root arc with binary flags ORN = Horizontal and  $DRCTNX\_FLAG_{induced} = 1$ .
+
+Diagram a) showing a vertical root arc with binary flags ORN = Horizontal and DRCTNX\_FLAG\_induced = 1. The diagram includes a horizontal dashed line (BLN), a red diagonal line (BIL), and a green arc (BSA). Vectors G^bsa and G^wdg are shown as blue arrows. A black 'X' marks the BIP point.
+
+![Diagram b) showing a horizontal root arc with binary flags ORN = Diagonal and DRCTNX_FLAG_induced = 1. The diagram shows a diagonal dashed line (BLN), a red diagonal line (BIL), and a green arc (BSA). Vectors G^bsa and G^wdg are shown as blue arrows. A black 'X' marks the BIP point.](2a25e8bc21554c0efceda1a8ccf57db3_img.jpg)
+
+b) Horizontal root arc with binary flags ORN = Diagonal and  $DRCTNX\_FLAG_{induced} = 1$ .
+
+Diagram b) showing a horizontal root arc with binary flags ORN = Diagonal and DRCTNX\_FLAG\_induced = 1. The diagram shows a diagonal dashed line (BLN), a red diagonal line (BIL), and a green arc (BSA). Vectors G^bsa and G^wdg are shown as blue arrows. A black 'X' marks the BIP point.
+
+BIP   base-intersection-point   BSA   base-arc  
+BLN   base-line   BIL   break-inducing-line
+
+**Figure 12 – Examples showing base-arc  $bsa$  and gradients  $G^{bsa}$  and  $G^{wdg}$  along with corresponding binary flags ORN and  $DRCTNX\_FLAG_{induced}$  for root arcs**
+
+Figure 13 identifies the base-arc for the spatial induction configuration presented in Figure 11.
+
+![Diagram showing a diagonal non-root arc with a spatially induced break. It includes a horizontal dashed line (BLN), a red diagonal line (BIL), a green arc (NRA), and a blue-outlined wedge area (WDA). Vectors G^bsa and G^wdg are indicated with blue arrows. A black 'X' marks the BIP point.](62a4c9055642dbb00663e633332f04d3_img.jpg)
+
+BIP   base-intersection-point   BSA   base-arc   BLN   base-line  
+BIL   break-inducing-line   WDA   wedge area   NRA   non-root arc
+
+Diagram showing a diagonal non-root arc with a spatially induced break. It includes a horizontal dashed line (BLN), a red diagonal line (BIL), a green arc (NRA), and a blue-outlined wedge area (WDA). Vectors G^bsa and G^wdg are indicated with blue arrows. A black 'X' marks the BIP point.
+
+For the diagonal non-root arc containing a spatially induced break, the corresponding binary flags ORN = Horizontal and  $DRCTNX\_FLAG_{induced} = 1$ .
+
+**Figure 13 – Example showing base-arc  $bsa$  and gradients  $G^{bsa}$  and  $G^{wdg}$  along with corresponding binary flags ORN and  $DRCTNX\_FLAG_{induced}$  for diagonal non-root arc containing a spatially induced break**
+
+### 8.2.5 Arcs with $t_b = 1$
+
+#### 8.2.5.1 Introduction
+
+For an arc  $a$  centred at location  $\mathbf{p}$  with  $t_b(\mathbf{p}) = 1$ , two options are pursued to infer a gradient along the arc. These options involve other arcs at the same resolution and within a specified spatial proximity of the arc  $a$ .
+
+Let  $\mathbf{p} = 2\mathbf{g} + \boldsymbol{\delta}$  denote the location of the centre of an arc  $a$  which contains a spatially induced break, where  $\mathbf{g} = (g_n, g_m)$  is an integer valued vector and  $\boldsymbol{\delta} = (\delta_n, \delta_m) \in \{(1,0), (0,1), (s_{LR}, 1)\}$ . The end point of the arc  $a$  that falls on the same side of the break as the centre of the arc is identified as the *base-grid-point*  $\mathbf{p}^{\text{base}}$  and is given by
+
+$$\mathbf{p}^{\text{base}} = \begin{cases} 2\mathbf{g} & \text{if } k_b(\mathbf{p}) > 2^{d+F_B-1} \\ 2\mathbf{g} + 2\boldsymbol{\delta} & \text{if } k_b(\mathbf{p}) < 2^{d+F_B-1} \end{cases} \quad (17)$$
+
+At resolution  $r$  of the current arc  $a$ , the grid line which contains the base-grid-point and having orientation  $ORN$  is referred to as the *base-line*. The orientation, either horizontal, vertical or diagonal is determined by the operator  $ORN\_4SPAN$  as shown below and defined in 8.2.5.5.
+
+$$ORN = ORN\_4SPAN(p, k_b(p))$$
+
+For an arc with a spatially induced break, there are always two breaks defined on other arcs that are the source breaks of the spatial induction. The line formed by these two induction source breaks, is referred to as the *break-inducing-line*. Examples of spatial induction for root arcs is shown in Figure 10 while an example of spatial induction for a non-root arc is illustrated by Figure 11.
+
+For the arc  $a$  centred at location  $\mathbf{p}$  with  $t_b(\mathbf{p}) = 1$  two options, known as WDG and PRL, are considered to infer a gradient along the arc. Each of these two options has an associated validity flag, and a gradient value that is meaningful if the corresponding validity flag is TRUE. The validity flags and gradient values are listed below.
+
+- Flag VALID\_WDG is set to TRUE if the WDG option identifies a valid gradient  $G_b^{wdg}$ , derived from arcs located in the wedge region WDG\_REGION bounded by the base-line and the break-inducing-line.
+- Flag VALID\_PRL is set to TRUE if the PRL option identifies a valid gradient  $G_b^{prl}$ , derived from an arc that is parallel to the arc  $a$  and shares the base-grid-point  $\mathbf{p}^{\text{base}}$ .
+
+The conditions for setting the flags VALID\_WDG and VALID\_PRL and the process of determining the associated gradient values are detailed below. In these discussions, an operator  $GRAD(\mathbf{p})$ , as defined in Formula (18), is used to determine the gradient of an arc at resolution  $r$ , centred at location  $\mathbf{p} = (2n + \delta_n, 2m + \delta_m)$  with  $(\delta_n, \delta_m) \in \{(1,0), (0,1), (s_{LR}, 1)\}$ .
+
+$$GRAD(\mathbf{p}) = I_{c,r}(2n + 2\delta_n, 2m + 2\delta_m) - I_{c,r}(2n, 2m) \quad (18)$$
+
+#### 8.2.5.2 VALID\_WDG and $G_{wdg}$
+
+There are two arcs at resolution  $r$  that are on the base-line and share the base-grid-point  $\mathbf{p}^{\text{base}}$ . Of these two arcs, the arc with its centre located away from  $\mathbf{p}^{\text{base}}$  in the direction  $DRCTNX\_FLAG_{\text{induced}}$  is identified as the base-arc  $bsa$  with  $\mathbf{p}^{\text{bsa}}$  corresponding to the centre location of the arc. The direction  $DRCTNX\_FLAG_{\text{induced}}$  of the current arc  $a$  centred at location  $\mathbf{p}$  is determined as shown below.
+
+$$DRCTNX\_FLAG_{\text{induced}}(\mathbf{p}) = \begin{cases} DRCTN1\_FLAG_{\text{induced}} & k_b(\mathbf{p}) > 2^{d+F_B-1} \\ DRCTN2\_FLAG_{\text{induced}} & k_b(\mathbf{p}) < 2^{d+F_B-1} \end{cases}$$
+
+where the values of the binary flags  $DRCTN1\_FLAG_{\text{induced}}$  and  $DRCTN2\_FLAG_{\text{induced}}$  are defined by the extrapolation-qualifier  $e_b$  for the arc as specified in 7.5. The location of the base arc  $\mathbf{p}^{\text{bsa}}$ , along the base-line having orientation  $ORN$ , is given by
+
+$$\mathbf{p}^{\text{bsa}} = \mathbf{p}^{\text{base}} + (2 \times DRCTNX\_FLAG_{\text{induced}}(\mathbf{p}) - 1) \boldsymbol{\delta}_{ORN}$$
+
+$$\boldsymbol{\delta}_{ORN} = \begin{cases} (1,0) & \text{if } ORN = \text{Horizontal} \\ (0,1) & \text{if } ORN = \text{Vertical} \\ (s_{LR}, 1) & \text{if } ORN = \text{Diagonal} \end{cases}$$
+
+The orientation value  $ORN$  of the base-line is determined as explained in 8.2.5.5.
+
+If base-arc  $bsa$  contains a break, that is  $t_b(\mathbf{p}^{\text{bsa}}) > 0$ , then the flag VALID\_WDG is set to false (VALID\_WDG = FALSE). Otherwise, a process is initiated to identify a specific arc  $wdg$  located inside the WDG\_REGION and to determine its gradient  $G^{wdg}$  and validity flag VALID\_WDG, as detailed below.
+
+To evaluate  $G^{wdg}$ , a set of candidate arcs  $W$  from the current resolution  $r$  is first determined such that the centre location  $\mathbf{p}_c^W$  of an arc in this set is given by
+
+$$\mathbf{p}_c^W = \mathbf{p} + c \cdot (2 \times \text{DRCTNX}_{\text{FLAG}_{\text{induced}}}(\mathbf{p}) - 1) \delta_{ORN}$$
+
+where  $c \in (1, 2, 3, \dots, C)$  with increasing values of  $c$  corresponding to increasing distance from  $\mathbf{p}$  and the maximum index value  $C$  determined by the maximum allowed distance MAX\_WDG.
+
+The candidate arcs in the set  $W$  are evaluated in order of increasing distance from  $\mathbf{p}$  to identify a specific arc  $wdg$  as detailed below.
+
+The evaluation process starts with  $c = 1$  and proceeds as follows:
+
+- Step 1  
+If  $c > C$  then the evaluation process is terminated and VALID\_WDG = FALSE.
+- Step 2  
+If the arc centred at  $\mathbf{p}_c^W$  contains a vertex (i.e.,  $t_b(\mathbf{p}_c^W) = 3$ ) or directly induced break (i.e.,  $t_b(\mathbf{p}_c^W) = 2$ ) then the evaluation process is terminated and VALID\_WDG = FALSE.
+- Step 3  
+If the arc centred at  $\mathbf{p}_c^W$  is devoid of any breaks, that is  $t_b(\mathbf{p}_c^W) = 0$ , then  $wdg$  is equated to the arc centred at  $\mathbf{p}_c^W$  (i.e.,  $\mathbf{p}^{wdg} = \mathbf{p}_c^W$ ). The operator  $PARENT\_RES\_4\_SPAN()$  is used to determine the highest resolution  $r^{a,wdg}$  at which a 4-span arrangement is inclusive of both arcs  $wdg$  and  $a$ .  
+$$r^{a,wdg} = PARENT\_RES\_4\_SPAN(\mathbf{p}^{wdg}, \mathbf{p})$$
+  
+If the value for  $r^{a,wdg}$  is less than 1 then this implies that a common 4-span arrangement does not exist for arcs  $wdg$  and  $a$ , hence VALID\_WDG = FALSE. However, if  $r^{a,wdg}$  is within permissible limits, ranging in value from  $r - 1$  to 1, then VALID\_WDG = TRUE. Finally, the evaluation process is terminated at this step.
+- Step 4  
+If the arc centred at  $\mathbf{p}_c^W$  contains a spatially induced break (i.e.,  $t_b(\mathbf{p}_c^W) = 1$ ) then  $c = c + 1$  and the evaluation process continues by returning to Step 1.
+
+If in the evaluation process above the flag VALID\_WDG is set to true (VALID\_WDG = TRUE) then the gradient  $G^{wdg} = GRAD(\mathbf{p}^{wdg})$  across the arc  $wdg$  is calculated in accordance with Formula (18). The identified arc  $wdg$  shall not be parallel to the current arc  $a$ . In such cases the gradient  $G^{bsa}$  observed along the base-arc  $bsa$  is also calculated using the gradient operator such that  $G^{bsa} = GRAD(\mathbf{p}^{bsa})$ . Examples of base-arc  $bsa$  and corresponding gradient  $G^{bsa}$ , along with gradient  $G^{wdg}$  of the identified arc  $wdg$  located inside the wedge area are shown in Figure 12 and Figure 13 for the spatial induction cases illustrated in Figure 10 and Figure 11 respectively. Since  $wdg$  and  $bsa$  represent two non-parallel arcs, a vector addition of their respective gradients  $G^{wdg}$  and  $G^{bsa}$  is utilized to provide a candidate gradient  $G_b^{wdg}$  along the non-root arc  $a$ . The general equation for calculating  $G_b^{wdg}$  is shown in Formula (19).
+
+$$G_b^{wdg} = s_b (\alpha^{wdg} G^{wdg} + \alpha^{bsa} G^{bsa}) \quad (19)$$
+
+If the arc  $wdg$  is parallel to arc  $a$  then the corresponding weights  $\alpha^{wdg}$  and  $\alpha^{bsa}$  in Formula (19) are given below.
+
+- $\alpha^{wdg} = 1$  and  $\alpha^{bsa} = 0$ .
+
+Otherwise, the following rules apply for the corresponding weights  $\alpha^\eta$  where  $\eta \in \{wdg, bsa\}$
+
+- If current arc  $a$  is a diagonal arc then  $\alpha^\eta = s_{LR}$  if  $\eta$  is a horizontal arc otherwise  $\eta$  is a vertical arc and  $\alpha^\eta = 1$ .
+- If current arc  $a$  is a vertical arc then  $\alpha^\eta = 1$  if  $\eta$  is a diagonal arc otherwise  $\eta$  is a horizontal arc and  $\alpha^\eta = -s_{LR}$ .
+- If current arc  $a$  is a horizontal arc then  $\alpha^\eta = s_{LR}$  if  $\eta$  is a diagonal arc otherwise  $\eta$  is a vertical arc and  $\alpha^\eta = -s_{LR}$ .
+
+For arc  $a$  centred at location  $\mathbf{p}$ , the sign value  $s_b$  in Formula (19) is determined based on the location of break on arc  $a$  and is given by
+
+$$s_b = \begin{cases} 1 & k_b(\mathbf{p}) > 2^{d+F_B-1} \\ -1 & k_b(\mathbf{p}) < 2^{d+F_B-1} \end{cases} \quad (20)$$
+
+Figure 14 and Figure 15 show examples of arcs centred at  $\mathbf{p}$ .
+
+![Figure 14: Three diagrams illustrating arcs prl parallel in orientation to root arcs centred at p and containing a spatially induced break. Each diagram shows a grid of points with a central point p. A blue arrow labeled G^prl indicates the gradient across the arc prl. A red 'X' marks the break. The diagrams show different orientations of the arc prl relative to the grid.](7c6f50098db177c4ce9b137442170382_img.jpg)
+
+Figure 14: Three diagrams illustrating arcs prl parallel in orientation to root arcs centred at p and containing a spatially induced break. Each diagram shows a grid of points with a central point p. A blue arrow labeled G^prl indicates the gradient across the arc prl. A red 'X' marks the break. The diagrams show different orientations of the arc prl relative to the grid.
+
+Figure 14 – Examples of arcs  $prl$  parallel in orientation to root arcs centred at  $\mathbf{p}$  and containing a spatially induced break. Gradient calculated across arc  $prl$  is denoted as  $G^{prl}$
+
+![Figure 15: A diagram illustrating an arc prl parallel to the non-root arc centred and at p and containing a spatially induced break. The diagram shows a grid of points with a central point p. A blue arrow labeled G^prl indicates the gradient across the arc prl. A red 'X' marks the break. The diagram also shows a non-root arc (NRA) and a spatially induced break (SPB).](67f9de2f1a2e5acf0d35a9adbcbd2d22_img.jpg)
+
+Figure 15: A diagram illustrating an arc prl parallel to the non-root arc centred and at p and containing a spatially induced break. The diagram shows a grid of points with a central point p. A blue arrow labeled G^prl indicates the gradient across the arc prl. A red 'X' marks the break. The diagram also shows a non-root arc (NRA) and a spatially induced break (SPB).
+
+SPB      spatially induced break  
+NRA      non-root arc
+
+Figure 15 – Example of arc  $prl$  parallel to the non-root arc centred and at  $\mathbf{p}$  and containing a spatially induced break. Corresponding gradient across arc  $prl$  is shown as  $G^{prl}$
+
+#### 8.2.5.3 VALID\_PRL and $G^{prl}$
+
+The arc at resolution  $r$  that shares the base-grid-point  $\mathbf{p}^{base}$  and has the same orientation as the current arc  $a$  is labelled  $prl$ . If the arc  $prl$  contains a break, that is  $t_b(\mathbf{p}^{prl}) > 0$ , then the flag VALID\_PRL is set to false (VALID\_PRL = FALSE). Alternatively, if  $prl$  is free of any breaks, that is  $t_b(\mathbf{p}^{prl}) = 0$ , then the highest resolution  $r^{a,prl}$  at which a 4-span arrangement is inclusive of both arcs  $prl$  and arc  $a$  is determined using the operator  $PARENT\_RES\_4\_SPAN()$  as shown below.
+
+$$r^{a,prl} = PARENT\_RES\_4\_SPAN(\mathbf{p}^{prl}, \mathbf{p}) \quad (21)$$
+
+If the value for  $r^{a,prl}$  is less than 1 then this implies that a common 4-span arrangement does not exist for arcs  $prl$  and  $a$ , hence the flag VALID\_PRL is set to false (VALID\_PRL = FALSE). However, if  $r^{a,prl}$  is within permissible limits, ranging in value from  $r - 1$  to 1 then, the flag VALID\_PRL is set to true (VALID\_PRL = TRUE) and the gradient  $G^{prl}$  is calculated, such that  $G^{prl} = GRAD(\mathbf{p}^{prl})$ .
+
+For performing extrapolation along current arc  $a$  centred at location  $\mathbf{p}$ , a candidate gradient  $G_b^{prl}$  is determined using the gradient  $G^{prl}$  of the neighbouring parallel arc  $prl$  and the sign value  $s_b$  that depends on the location of break on the current arc. The formula for determining  $G_b^{prl}$  is shown below where the value for  $s_b$  is specified by Formula (20).
+
+$$G_b^{prl} = s_b G^{prl} \quad (22)$$
+
+Examples of arcs  $prl$ , having parallel orientation with arc  $a$  centred at location  $\mathbf{p}$ , are shown in Figure 14 and Figure 15 along with the associated gradient  $G^{prl}$ .
+
+#### 8.2.5.4 Predict function
+
+The predict function for an arc  $a$  with a spatially induced break (i.e.,  $t_b(\mathbf{p}) = 1$ ) is given by
+
+$$P(I_{c,r}, LL_{D_c,r}, 2n + \delta_n, 2m + \delta_m) = \begin{cases} I_{c,r}(2n, 2m) + G_b & k_b(\mathbf{p}) > 2^{d+F_B-1} \\ I_{c,r}(2n + 2\delta_n, 2m + 2\delta_m) + G_b & k_b(\mathbf{p}) < 2^{d+F_B-1} \end{cases} \quad (23)$$
+
+and the procedure for determining  $G_b$  from the evaluated validity flags VALID\_WDG and VALID\_PRL, and corresponding gradients  $G_b^{wdg}$  and  $G_b^{prl}$  is specified in Figure 16.
+
+![](6470d350326789d5306eabcb76533951_img.jpg)
+
+```
+
+IF (VALID_WDG = FALSE) AND (VALID_PRL = FALSE) THEN
+     $G_b = 0$ 
+ELSE IF (VALID_WDG = TRUE) AND (VALID_PRL = FALSE) THEN
+     $G_b = 0.5 * G_b^{wdg}$ 
+ELSE IF (VALID_WDG = FALSE) AND (VALID_PRL = TRUE) THEN
+     $G_b = 0.5 * G_b^{prl}$ 
+ELSE IF (VALID_WDG = TRUE) AND (VALID_PRL = TRUE) THEN
+    IF ( $r^{a,wdg} > r^{a,prl}$ )
+         $G_b = 0.5 * G_b^{wdg}$ 
+    ELSE IF ( $r^{a,prl} > r^{a,wdg}$ )
+         $G_b = 0.5 * G_b^{prl}$ 
+    ELSE
+
+```
+
+**Figure 16 – Algorithm for determining the gradient  $G_b$  based on validity flags VALID\_WDG and VALID\_PRL and corresponding attributes**
+
+NOTE – If both flags VALID\_WDG and VALID\_PRL are false, then the predict function essentially reverts to performing constant extrapolation along the arc  $a$ . If only one of the validity flags is true, then the corresponding valid gradient is utilized in performing linear extrapolation. If both flags are true, then the resolution at which there is a common shared parent becomes the determining factor. If both  $r^{a,wdg}$  and  $r^{a,prl}$  are equal, then an average of the gradients  $G_b^{wdg}$  and  $G_b^{prl}$  is used to perform linear extrapolation, otherwise the gradient corresponding to the higher resolution is chosen for the extrapolation function.
+
+#### 8.2.5.5 Identifying orientation ORN
+
+For an arc  $a$  at resolution  $r$ , the operator  $PARENT\_RES\_ROOT\_ARC()$  is used to identify the resolution level  $r^{rt}$  at which  $a$  is either a root arc or becomes a sub-arc of a root arc. This is shown below.
+
+$$r^{rt} = PARENT\_RES\_ROOT\_ARC(\mathbf{p}) \quad (24)$$
+
+where for arc  $a$  with a spatially induced break,  $r^{rt}$  can range in value from  $r$  to 1. The root arc at resolution level  $r^{rt}$  that is inclusive of  $a$  is labelled  $rt$ .
+
+NOTE – If  $r^{rt} = r$  then this means that  $rt = a$ . If  $r^{rt} < r$  then  $a$  is a sub-arc of  $rt$ .
+
+The 4-span arrangement at resolution  $r^{rt}$  that is inclusive of the root arc  $rt$  is referred to as the *parent-4-span*. An example of a non-root arc  $a$  with a spatially induced break for the TriBPT-LR arrangement at resolution  $r$  is shown in Figure 11 (top). The corresponding parent-4-span at resolution  $r^{rt}$  is shown in Figure 11 (bottom) where in this example  $r^{rt} = r - 1$ .
+
+The centre coordinates  $\mathbf{p}^{rt}$  of root arc  $rt$ , in terms of the coordinates  $\mathbf{p} = (n, m)$  of arc  $a$ , is given by
+
+$$\mathbf{p}^{rt} = (n^{rt}, m^{rt}) = \left( \left\lfloor \frac{n}{2^{r-r^{rt}+1}} \right\rfloor \cdot 2 + (n \bmod 2), \left\lfloor \frac{m}{2^{r-r^{rt}+1}} \right\rfloor \cdot 2 + (m \bmod 2) \right)$$
+
+The two endpoints of arc  $rt$  are labelled *end-point1* and *end-point2*. The first endpoint, end-point1, is located on the left side of the arc for horizontal arcs or on top for vertical and diagonal arcs and the second endpoint, end-point2, is located on the right side for horizontal arcs or at the bottom for vertical and diagonal arcs. In the parent-4-span arrangement, there are two non-root arcs of the same orientation  $ORN1$  that share end-point1. Similarly, there are two non-root arcs of orientation  $ORN2$  that share the end-grid-point2. An example is provided in Figure 17 where for a non-root arc  $a$  at resolution  $r$  and centred at  $\mathbf{p}$ , the corresponding root-arc  $rt$  in the parent-4-span arrangement occurs at resolution  $r^{rt} = r - 1$ . The two endpoints of  $rt$  and the orientations of the non-root arcs at each endpoint are shown.
+
+![Figure 17: Parent 4-span arrangement at resolution r^{rt} = r - 1 for arc a at resolution r and centred at p. The diagram shows a grid of points with a blue arc 'a' and a green arc 'rt'. Arc 'a' is centered at point 'p' and has a break. Arc 'rt' is a root arc at resolution r^{rt} = r - 1. The endpoints of 'rt' are labeled EP1 and EP2. Non-root arcs at resolution r^{rt} sharing EP1 are labeled NR1, and non-root arcs at resolution r^{rt} sharing EP2 are labeled NR2. The diagram is labeled T.816(23).](00504fc688ebcf131ccbeff94dfc9939_img.jpg)
+
+Figure 17: Parent 4-span arrangement at resolution r^{rt} = r - 1 for arc a at resolution r and centred at p. The diagram shows a grid of points with a blue arc 'a' and a green arc 'rt'. Arc 'a' is centered at point 'p' and has a break. Arc 'rt' is a root arc at resolution r^{rt} = r - 1. The endpoints of 'rt' are labeled EP1 and EP2. Non-root arcs at resolution r^{rt} sharing EP1 are labeled NR1, and non-root arcs at resolution r^{rt} sharing EP2 are labeled NR2. The diagram is labeled T.816(23).
+
+|     |                                                                  |
+|-----|------------------------------------------------------------------|
+| EP1 | end-point1                                                       |
+| EP2 | end-point2                                                       |
+| NR1 | non-root arcs at resolution $r^{rt}$ sharing end-point1          |
+| NR2 | non-root arcs at resolution $r^{rt}$ sharing end-point2          |
+| a   | non-root arc at resolution $r$                                   |
+| rt  | root arc in the parent-4-span arrangement at resolution $r^{rt}$ |
+
+The orientation of the non-root arcs at the endpoints of  $rt$  determine the values for  $ORN1$  and  $ORN2$  such that in this example  $ORN1$ =Horizontal and  $ORN2$ =Vertical.
+
+**Figure 17 – Parent 4-span arrangement at resolution  $r^{rt} = r - 1$  for arc  $a$  at resolution  $r$  and centred at  $\mathbf{p}$**
+
+For an arc  $a$  centred at  $\mathbf{p}$  containing a break at location  $k_b(\mathbf{p})$ , the operator  $ORN\_4SPAN(\mathbf{p}, k_b(\mathbf{p}))$  identifies the corresponding orientation  $ORN$  as shown below.
+
+$$ORN\_4SPAN(\mathbf{p}, k_b(\mathbf{p})) = \begin{cases} ORN1 & k_b(\mathbf{p}) > 2^{d+F_B-1} \\ ORN2 & k_b(\mathbf{p}) < 2^{d+F_B-1} \end{cases}$$
+
+## 8.3 TriBPT-dependent reversible transforms
+
+In this clause, the reversible update and predict functions for TriBPT case is defined, relying upon the notations and definitions presented in 8.2.
+
+The reversible update step is implemented by making the following assignment for each (even, even) location  $(2n, 2m)$  of  $I_{c,r}$ .
+
+$$I_{c,r}(2n, 2m) = I_{c,r}(2n, 2m) - \left\lfloor \frac{\sum_{(\delta_n, \delta_m) \in \mathcal{N}_U} U(I_{c,r}, LL_{D_{c,r}}, 2n + \delta_n, 2m + \delta_m) + 4}{8} \right\rfloor \quad (25)$$
+
+where, as defined in 8.2,  $\mathcal{N}_U$  identifies the update neighbourhood.
+
+The update function  $U$  is given by
+
+$$U(I_{c,r}, LL_{D_{c,r}}, p_x, p_y) = \begin{cases} \mu * I_{c,r}(p_x, p_y), & \text{if } t_b(p_x, p_y) = 0 \\ 0, & \text{otherwise} \end{cases} \quad (26)$$
+
+where  $\mu = 1$ .
+
+The predict step is defined in Formula (12) and the associated predict function  $P(I_{c,r}, LL_{D_{c,r}}, \mathbf{p})$  for each breakpoint type is define below for the reversible transform.
+
+### 8.3.1 Arcs with $t_b = 0$
+
+For arcs without any breaks ( $t_b(\mathbf{p}) = 0$ ), the predict function is given by
+
+$$P(I_{c,r}, LL_{D_{c,r}}, \mathbf{p}) = \left\lfloor \frac{1}{2} (I_{c,r}(\mathbf{p}^A) + I_{c,r}(\mathbf{p}^B)) \right\rfloor \quad (27)$$
+
+where  $\mathbf{p}^A$  and  $\mathbf{p}^B$  are determined in accordance with Formula (14).
+
+### 8.3.2 Arcs with $t_b = 3$
+
+For arcs containing a vertex ( $t_b(\mathbf{p}) = 3$ ), the predict function for the reversible transform is identical to that defined by Function (15).
+
+### 8.3.3 Arcs with $t_b = 2$
+
+For arcs containing a directly induced break ( $t_b(\mathbf{p}) = 2$ ), the predict function is given by
+
+$$P(I_{c,r}, LL_{D_{c,r}}, \mathbf{p}) = \begin{cases} I_{c,r}(\mathbf{p}^A) + \lfloor G_b(\mathbf{p}, 2\mathbf{p}^A - \mathbf{p}) \rfloor & k_b(\mathbf{p}) > 2^{d+F_B-1} \\ I_{c,r}(\mathbf{p}^B) + \lfloor G_b(\mathbf{p}, 2\mathbf{p}^B - \mathbf{p}) \rfloor & k_b(\mathbf{p}) < 2^{d+F_B-1} \end{cases} \quad (28)$$
+
+where the derivation of  $G_b$  and corresponding locations  $\mathbf{p}^A$  and  $\mathbf{p}^B$  are specified in 8.2.2.
+
+### 8.3.4 Arcs with $t_b = 1$
+
+The predict function for an arc with a spatially induced break (i.e.,  $t_b(\mathbf{p}) = 1$ ) is given by
+
+$$P(I_{c,r}, LL_{D_{c,r}}, 2n + \delta_n, 2m + \delta_m) = \begin{cases} I_{c,r}(2n, 2m) + G_b & k_b(\mathbf{p}) > 2^{d+F_B-1} \\ I_{c,r}(2n + 2\delta_n, 2m + 2\delta_m) + G_b & k_b(\mathbf{p}) < 2^{d+F_B-1} \end{cases}$$
+
+The procedure for determining  $G_b$  for the reversible transform is specified in Figure 18. The required validity flags VALID\_WDG and VALID\_PRL, and corresponding gradients  $G_b^{wdg}$  and  $G_b^{prl}$  are defined in 8.2.5.
+
+ISO/IEC 15444-17:2023 (E)
+
+```
+
+IF (VALID_WDG = FALSE) AND (VALID_PRL = FALSE) THEN
+
+     $G_b = 0$ 
+
+ELSE IF (VALID_WDG = TRUE) AND (VALID_PRL = FALSE) THEN
+
+     $G_b = \lfloor \frac{1}{2} * G_b^{wdg} \rfloor$ 
+
+ELSE IF (VALID_WDG = FALSE) AND (VALID_PRL = TRUE) THEN
+
+     $G_b = \lfloor \frac{1}{2} * G_b^{prl} \rfloor$ 
+
+ELSE IF (VALID_WDG = TRUE) AND (VALID_PRL = TRUE) THEN
+
+    IF ( $r^{a,wdg} > r^{a,prl}$ )
+
+         $G_b = \lfloor \frac{1}{2} * G_b^{wdg} \rfloor$ 
+
+    ELSE IF ( $r^{a,prl} > r^{a,wdg}$ )
+
+         $G_b = \lfloor \frac{1}{2} * G_b^{prl} \rfloor$ 
+
+    ELSE
+    
+```
+
+**Figure 18 – Algorithm for determining the gradient  $G_b$  for the reversible transform, based on validity flags VALID\_WDG and VALID\_PRL and corresponding attributes**
+**8.4 QuadBPT-dependent transforms**
+**8.4.1 Introduction**
+
+For QuadBPT, the 2D\_GP\_MAPPING procedure maps the spatial sub-bands  $LL_{c,r}, HL_{c,r}, LH_{c,r}, HH_{c,r}$  to corresponding grid-point locations to form an interleaved band  $I_{c,r}$  such that  $I_{c,r} = \text{2D_GP_MAPPING}(LL_{c,r}, HL_{c,r}, LH_{c,r}, HH_{c,r}, trx_0, trx_1, try_0, try_1)$ , where  $(trx_0, try_0)$  specifies the upper left corner and  $(trx_1 - 1, try_1 - 1)$  the lower right corner of the rectangular grid-point region at resolution  $r$  that corresponds to  $I_{c,r}$ . The mapping of sub-band samples to grid-point locations for a given resolution  $r$  is illustrated in Figure 19.
+
+NOTE – As shown in Figure 19, the grid-point mapping procedure associates the samples of the  $HL_{c,r}$  and  $LH_{c,r}$  spatial sub-bands at the same locations as respective horizontal, vertical non-root arcs from the breakpoint component  $D_C$ , while  $HH_{c,r}$  is at the same location as where both the horizontal, vertical root arcs are associated in  $D_C$ .
+
+![Diagram showing the interleaving of sub-band coefficients LL, HL, LH, and HH onto a 2x2 grid. LL(n,m) is at (2n, 2m). HL(n,m) is at (2n+1, 2m). LH(n,m) is at (2n, 2m+1). HH(n,m) is at (2n+1, 2m+1). Red arrows indicate the grid structure connecting these points.](645cfdb7a7e02c3b04b20d83aed890c3_img.jpg)
+
+Detailed description: The diagram shows a 2x2 grid of points. The top-left point is labeled  $LL_{c,r}(n, m)$  at coordinates  $2n, 2m$ . To its right is a point at  $2n+1$  associated with  $HL_{c,r}(n, m)$ . Below the top-left point is a point at  $2m+1$  associated with  $LH_{c,r}(n, m)$ . The bottom-right point at  $2n+2, 2m+2$  is associated with  $HH_{c,r}(n, m)$ . Red arrows form a square connecting the outer points, and dashed blue lines intersect at the center point.
+
+Diagram showing the interleaving of sub-band coefficients LL, HL, LH, and HH onto a 2x2 grid. LL(n,m) is at (2n, 2m). HL(n,m) is at (2n+1, 2m). LH(n,m) is at (2n, 2m+1). HH(n,m) is at (2n+1, 2m+1). Red arrows indicate the grid structure connecting these points.
+
+**Figure 19 – Interleaving of sub-band coefficients to a quadrilateral grid for a given resolution  $r$** 
+**Rec. ITU-T T.816 (V1) (02/2023)**      23
+
+The interleaved band  $I_{c,r}$  produced by the 2D\_GP\_MAPPING procedure, is subject to a breakpoint adaptive 2D sub-band reconstruction BD\_2D\_SR, which consists of four lifting steps conducted in two phases. At the completion of Phase 1, samples at (odd, odd) locations are reconstructed after which performing Phase 2 reconstructs the remaining samples at locations (even, even), (even, odd) and (odd, even).
+
+### 8.4.2 BD\_2D\_SR phase 1
+
+In Phase 1, an update step is applied first, modifying sub-band samples at grid-points  $(p_x, p_y)$  that are (even, even), (even, odd) and (odd, even). The update step is dependent on sub-band samples at (odd, odd) locations  $(2n + 1, 2m + 1)$  of  $I_{c,r}$  and corresponding binary variables  $\beta(2n + 1, 2m + 1)$  determined by
+
+$$\beta(2n + 1, 2m + 1) = \begin{cases} 1 & \text{if } t_b(2n + \delta_n, 2m + \delta_m) = t_b(2n + 1, 2m + 1, H) = t_b(2n + 1, 2m + 1, V) = 0 \\ 0 & \text{otherwise} \end{cases} \quad (29)$$
+
+where  $(\delta_n, \delta_m) = \{(1,0), (0,1), (1,2), (2,1)\}$ ,  $t_b(2n + \delta_n, 2m + \delta_m)$  is the arc break-type found from  $LL_{D_{c,r}}(2n + \delta_n, 2m + \delta_m)$  for non-root arcs and  $t_b(2n + 1, 2m + 1, H)$  and  $t_b(2n + 1, 2m + 1, V)$  refer to the breakpoint type for horizontal and vertical root arcs respectively at  $LL_{D_{c,r}}(2n + 1, 2m + 1)$ . As defined in clause 7,  $t_b = 0$  means that there is no break on the arc.
+
+NOTE –  $\beta(2n + 1, 2m + 1)$  is equal to 1 if all 6 arcs of the 2-span centred at  $(2n + 1, 2m + 1)$  are free of any breaks, otherwise it is set to 0.
+
+The update step that modifies (even, even) locations during Phase 1 is defined below.
+
+$$I_{c,r}(2n, 2m) = I_{c,r}(2n, 2m) - \sum_{(\delta_n, \delta_m) \in \mathcal{N}_{1,a}} U^{1,a}(I_{c,r}, LL_{D_{c,r}}, 2n + \delta_n, 2m + \delta_m) \quad (30)$$
+
+Here,  $\mathcal{N}_{1,a} = \{(1,1), (1,-1), (-1,1), (-1,-1)\}$  identifies the update neighbourhood, and the update function  $U^{1,a}$  is given by
+
+$$U^{1,a}(I_{c,r}, LL_{D_{c,r}}, p_x, p_y) = \begin{cases} \mu^{1,a} * I_{c,r}(p_x, p_y), & \text{if } \beta(p_x, p_y) = 1 \\ 0, & \text{otherwise} \end{cases} \quad (31)$$
+
+where  $\mu^{1,a} = 0.04701$ . Figure 20 shows the operation of the update step for an (even, even) location, providing examples with no breakpoints and when breakpoints are present on a neighbouring 2-span QuadBPT arrangement.
+
+![Figure 20: Phase 1 update step for (even, even) location (2n, 2m). The figure consists of two diagrams, (a) and (b), showing a 5x5 grid of points. The horizontal axis is labeled 2n-2, 2n, 2n+2 and the vertical axis is labeled 2m-2, 2m, 2m+2. In diagram (a), 'Update step in the absence of breakpoints', all arcs between points are solid red lines. Dashed blue arrows labeled mu^{1,a} point from the four neighbors (2n-1, 2m-1), (2n+1, 2m-1), (2n-1, 2m+1), and (2n+1, 2m+1) towards the center point (2n, 2m). In diagram (b), 'Update step in the presence of breakpoints on arcs of a neighbouring 2-span arrangement', the grid is similar, but the arcs between (2n-1, 2m-1) and (2n, 2m-1), and between (2n, 2m-1) and (2n+1, 2m-1) are marked with red 'X's and labeled 'BRK' with arrows. The dashed blue arrows labeled mu^{1,a} are still present, pointing towards the center point (2n, 2m).](0fa5b60804100c3aead10404f9f226f9_img.jpg)
+
+a) Update step in the absence of breakpoints
+
+b) Update step in the presence of breakpoints on arcs of a neighbouring 2-span arrangement
+
+Figure 20: Phase 1 update step for (even, even) location (2n, 2m). The figure consists of two diagrams, (a) and (b), showing a 5x5 grid of points. The horizontal axis is labeled 2n-2, 2n, 2n+2 and the vertical axis is labeled 2m-2, 2m, 2m+2. In diagram (a), 'Update step in the absence of breakpoints', all arcs between points are solid red lines. Dashed blue arrows labeled mu^{1,a} point from the four neighbors (2n-1, 2m-1), (2n+1, 2m-1), (2n-1, 2m+1), and (2n+1, 2m+1) towards the center point (2n, 2m). In diagram (b), 'Update step in the presence of breakpoints on arcs of a neighbouring 2-span arrangement', the grid is similar, but the arcs between (2n-1, 2m-1) and (2n, 2m-1), and between (2n, 2m-1) and (2n+1, 2m-1) are marked with red 'X's and labeled 'BRK' with arrows. The dashed blue arrows labeled mu^{1,a} are still present, pointing towards the center point (2n, 2m).
+
+BRK breakpoint locations
+
+Figure 20 – Phase 1 update step for (even, even) location  $(2n, 2m)$
+
+The update step that modifies (odd, even) location is defined below.
+
+$$I_{c,r}(2n+1, 2m) = I_{c,r}(2n+1, 2m) - \sum_{(\delta_n, \delta_m) \in \mathcal{N}_{1,b}} U^{1,b}(I_{c,r}, LL_{D_{c,r}}, 2n + \delta_n, 2m + \delta_m) \quad (32)$$
+
+where  $\mathcal{N}_{1,b} = \{(1,1), (1,-1)\}$  identifies the update neighbourhood and the update function  $U^{1,b}$  is given by
+
+$$U^{1,b}(I_{c,r}, LL_{D_{c,r}}, p_x, p_y) = \begin{cases} \mu^{1,b} * I_{c,r}(p_x, p_y), & \text{if } \beta(p_x, p_y) = 1 \\ 0, & \text{otherwise} \end{cases} \quad (33)$$
+
+with  $\mu^{1,b} = 0.1479$ .
+
+The update step that modifies (even, odd) locations is given by
+
+$$I_{c,r}(2n, 2m+1) = I_{c,r}(2n, 2m+1) - \sum_{(\delta_n, \delta_m) \in \mathcal{N}_{1,c}} U^{1,b}(I_{c,r}, LL_{D_{c,r}}, 2n + \delta_n, 2m + \delta_m) \quad (34)$$
+
+where  $\mathcal{N}_{1,c} = \{(1,1), (-1,1)\}$  identifies the update neighbourhood and the update function  $U^{1,b}$  is defined above in Formula (33).
+
+Examples of the update step for locations  $(2n+1, 2m)$  and  $(2n, 2m+1)$  are shown in Figure 21.
+
+![Figure 21: Phase 1 update step for (even, odd) location (2n, 2m+1) and (odd, even) location (2n+1, 2m). The figure consists of two diagrams, (a) and (b), showing a 5x5 grid of points. In (a), the update step for (2n+1, 2m) is shown, with red arrows indicating the update from (2n, 2m) and (2n+2, 2m) to (2n+1, 2m). In (b), the update step for (2n, 2m+1) is shown, with red arrows indicating the update from (2n, 2m) and (2n, 2m+2) to (2n, 2m+1). Both diagrams show the update function U^{1,b} applied to the intermediate values. A legend indicates that BRK represents breakpoint locations.](05d8710f69c476939295486ab1440350_img.jpg)
+
+a) Update step in the absence of breakpoints
+
+b) Update step in the presence of breakpoints
+
+BRK breakpoint locations
+
+Figure 21: Phase 1 update step for (even, odd) location (2n, 2m+1) and (odd, even) location (2n+1, 2m). The figure consists of two diagrams, (a) and (b), showing a 5x5 grid of points. In (a), the update step for (2n+1, 2m) is shown, with red arrows indicating the update from (2n, 2m) and (2n+2, 2m) to (2n+1, 2m). In (b), the update step for (2n, 2m+1) is shown, with red arrows indicating the update from (2n, 2m) and (2n, 2m+2) to (2n, 2m+1). Both diagrams show the update function U^{1,b} applied to the intermediate values. A legend indicates that BRK represents breakpoint locations.
+
+**Figure 21 – Phase 1 update step for (even, odd) location  $(2n, 2m+1)$  and (odd, even) location  $(2n+1, 2m)$**
+
+After the update step, a prediction step is performed that modifies (odd, odd) locations of  $I_{c,r}$ . To perform this predict step an intermediate interleaved band  $I_{c,r}^*$  is first created, to store intermediate values at (odd, even) and (even, odd) locations as shown below.
+
+$$I_{c,r}^*(\mathbf{p}) = \begin{cases} I_{c,r}(\mathbf{p}) + I_{c,r}(\mathbf{p}^A) & \text{if } t_b(\mathbf{p}) \neq 0 \text{ and } k_b(\mathbf{p}) > 2^{d+F_B-1} \\ I_{c,r}(\mathbf{p}) + I_{c,r}(\mathbf{p}^B), & \text{if } t_b(\mathbf{p}) \neq 0 \text{ and } k_b(\mathbf{p}) < 2^{d+F_B-1} \\ \frac{5}{6}I_{c,r}(\mathbf{p}) + \frac{I_{c,r}(\mathbf{p}^A) + I_{c,r}(\mathbf{p}^B)}{2}, & \text{if } t_b(\mathbf{p}) = 0 \end{cases} \quad (35)$$
+
+where  $\mathbf{p} \in \{(2m+1, 2n), (2m, 2n+1)\}$  and locations  $\mathbf{p}^A$  and  $\mathbf{p}^B$  are given by
+
+$$[\mathbf{p}^A, \mathbf{p}^B] = \begin{cases} [(2n, 2m), (2n+2, 2m)] & \text{if } \mathbf{p} = (2n+1, 2m) \\ [(2n, 2m), (2n, 2m+2)] & \text{if } \mathbf{p} = (2n, 2m+1) \end{cases} \quad (36)$$
+
+The predict step, which reconstructs the sample at (odd, odd) locations by utilising the intermediate interleaved band  $I_{c,r}^*$  values at neighbouring (odd, even) and (even, odd) locations is shown below.
+
+$$I_{c,r}(2n+1, 2m+1) = I_{c,r}(2n+1, 2m+1) + \frac{1}{2}P_H(I_{c,r}^*, LL_{D_{c,r}}, 2n+1, 2m+1) + \frac{1}{2}P_V(I_{c,r}^*, LL_{D_{c,r}}, 2n+1, 2m+1) \quad (37)$$
+
+where the predict functions  $P_H$  and  $P_V$  utilize intermediate values located at endpoints of horizontal and vertical root arcs respectively. For horizontal and vertical root arcs centred at  $\mathbf{p} = (2n+1, 2m+1)$ , the predict functions  $P_H$  and  $P_V$  are defined below.
+
+$$P_H(I_{c,r}^*, LL_{D_{c,r}}, \mathbf{p}) = \begin{cases} \frac{1}{2}(I_{c,r}^*(\mathbf{p}^A) + I_{c,r}^*(\mathbf{p}^B)) & t_b(\mathbf{p}, H) = 0 \\ I_{c,r}^*(\mathbf{p}^A) & \text{if } t_b(\mathbf{p}, H) \neq 0 \text{ and } k_b(\mathbf{p}) > 2^{d+F_B-1} \\ I_{c,r}^*(\mathbf{p}^B) & \text{if } t_b(\mathbf{p}, H) \neq 0 \text{ and } k_b(\mathbf{p}) < 2^{d+F_B-1} \end{cases} \quad (38)$$
+
+Here source locations  $\mathbf{p}^A = (2n, 2m+1)$  and  $\mathbf{p}^B = (2n+2, 2m+1)$  in the predict function  $P_H$  above.
+
+$$P_V(I_{c,r}^*, LL_{D_{c,r}}, \mathbf{p}) = \begin{cases} \frac{1}{2}(I_{c,r}^*(\mathbf{p}^A) + I_{c,r}^*(\mathbf{p}^B)) & t_b(\mathbf{p}, V) = 0 \\ I_{c,r}^*(\mathbf{p}^A) & \text{if } t_b(\mathbf{p}, V) \neq 0 \text{ and } k_b(\mathbf{p}) > 2^{d+F_B-1} \\ I_{c,r}^*(\mathbf{p}^B) & \text{if } t_b(\mathbf{p}, V) \neq 0 \text{ and } k_b(\mathbf{p}) < 2^{d+F_B-1} \end{cases} \quad (39)$$
+
+Source locations  $\mathbf{p}^A = (2n+1, 2m)$  and  $\mathbf{p}^B = (2n+1, 2m+2)$  in the predict function  $P_V$ . Examples of the source locations of  $I_{c,r}^*$  used in the predict function are shown in Figure 22.
+
+![Figure 22: Phase 1 predict step for (odd, odd) location (2n+1, 2m+1) with source locations of I_{c,r}^* shown. The figure consists of two diagrams, (a) and (b), showing a 3x3 grid of points. The horizontal axis is labeled 2n, 2n+1, 2n+2 and the vertical axis is labeled 2m, 2m+1, 2m+2. In diagram (a), 'Predict step in the absence of breakpoints', the central point (2n+1, 2m+1) is connected to its four neighbors (2n, 2m+1), (2n+2, 2m+1), (2n+1, 2m), and (2n+1, 2m+2) by dashed arcs. Each arc is labeled with a weight of 1/4. In diagram (b), 'Predict step in the presence of breakpoints', the central point is connected to its four neighbors by dashed arcs. The horizontal arcs are labeled 1/4, and the vertical arcs are labeled 1/2. A red 'X' is placed at the top-right neighbor (2n+2, 2m+1), and a label 'BRK' with an arrow points to it. The label 'T.816(23)' is at the bottom right of diagram (b).](409498e57b1f988b2b604d12cd997002_img.jpg)
+
+Figure 22: Phase 1 predict step for (odd, odd) location (2n+1, 2m+1) with source locations of I\_{c,r}^\* shown. The figure consists of two diagrams, (a) and (b), showing a 3x3 grid of points. The horizontal axis is labeled 2n, 2n+1, 2n+2 and the vertical axis is labeled 2m, 2m+1, 2m+2. In diagram (a), 'Predict step in the absence of breakpoints', the central point (2n+1, 2m+1) is connected to its four neighbors (2n, 2m+1), (2n+2, 2m+1), (2n+1, 2m), and (2n+1, 2m+2) by dashed arcs. Each arc is labeled with a weight of 1/4. In diagram (b), 'Predict step in the presence of breakpoints', the central point is connected to its four neighbors by dashed arcs. The horizontal arcs are labeled 1/4, and the vertical arcs are labeled 1/2. A red 'X' is placed at the top-right neighbor (2n+2, 2m+1), and a label 'BRK' with an arrow points to it. The label 'T.816(23)' is at the bottom right of diagram (b).
+
+BRK breakpoint locations
+
+**Figure 22 – Phase 1 predict step for (odd, odd) location  $(2n+1, 2m+1)$  with source locations of  $I_{c,r}^*$  shown**
+
+### 8.4.3 BD\_2D\_SR phase 2
+
+In Phase 2, an update step is applied first, modifying sub-band samples at grid-points  $(p_x, p_y)$  that are (even, even). The update step is dependent on sub-band samples at (even, odd) locations  $(2n, 2m+1)$  and (odd, even) locations  $(2n+1, 2m)$  of  $I_{c,r}$ . The update step is implemented by making the following assignment for each (even, even) location  $(2n, 2m)$  of  $I_{c,r}$ .
+
+$$I_{c,r}(2n, 2m) = I_{c,r}(2n, 2m) - \sum_{(\delta_n, \delta_m) \in \mathcal{N}_2} U^{(2)}(I_{c,r}, LL_{D_{c,r}}, 2n + \delta_n, 2m + \delta_m) \quad (40)$$
+
+Here,  $\mathcal{N}_2 = \{(1,0), (0,1), (-1,0), (0,-1)\}$  identifies the update neighbourhood, and the update function  $U^{(2)}$  is given by
+
+$$U^{(2)}(I_{c,r}, LL_{D_{c,r}}, p_x, p_y) = \begin{cases} \mu^{(2)} * I_{c,r}(p_x, p_y), & \text{if } t_b(p_x, p_y) = 0, \\ 0, & \text{otherwise} \end{cases}, \quad (41)$$
+
+where  $\mu^{(2)} = \frac{1}{6}$  and  $t_b(p_x, p_y)$  is the arc break-type found from  $LL_{D_{c,r}}(p_x, p_y)$ . Figure 23 shows the operation of the update step for an (even, even) location, providing examples with no breakpoints and when breakpoints are present on a neighbouring arc.
+
+After the update step of Phase 2, the (even, even) indexed sub-band samples located at end points of arcs at resolution  $r$  are utilized in performing a predict lifting step by making the following assignment for each (even, odd) and (odd, even) location  $\mathbf{p}$  within  $I_{c,r}$ :
+
+$$I_{c,r}(\mathbf{p}) = I_{c,r}(\mathbf{p}) + P^{(2)}(I_{c,r}, LL_{D_{c,r}}, \mathbf{p}), \quad (42)$$
+
+For a non-root arc centred at location  $\mathbf{p} = (p_x, p_y)$ , the predict function  $P^{(2)}()$  is dependent on the corresponding break-type  $t_b(p_x, p_y)$ , as well as the location of the break  $k_b(p_x, p_y)$ , as given by  $LL_{D_{c,r}}(p_x, p_y)$ . The predict function is given by
+
+$$P^{(2)}(I_{c,r}, LL_{D_{c,r}}, \mathbf{p}) = \begin{cases} \frac{1}{2}(I_{c,r}(\mathbf{p}^A) + I_{c,r}(\mathbf{p}^B)) & t_b(\mathbf{p}) = 0 \\ I_{c,r}(\mathbf{p}^A) & \text{if } t_b(\mathbf{p}) \neq 0 \text{ and } k_b(\mathbf{p}) > 2^{d+F_B-1} \\ I_{c,r}(\mathbf{p}^B) & \text{if } t_b(\mathbf{p}) \neq 0 \text{ and } k_b(\mathbf{p}) < 2^{d+F_B-1} \end{cases} \quad (43)$$
+
+where source locations  $\mathbf{p}^A$  and  $\mathbf{p}^B$  are given by Formula (36). Examples of the Phase 2 predict function are shown in Figure 24.
+
+![Figure 23: Phase 2 update step for (even, even) location (2n, 2m). The figure consists of two diagrams, (a) and (b), showing a 5x5 grid of nodes. The horizontal axis is labeled with 2n-2, 2n, and 2n+2. The vertical axis is labeled with 2m-2, 2m, and 2m+2. In diagram (a), 'Update step in the absence of breakpoints', the central node (2n, 2m) is updated from its four immediate neighbors (2n-2, 2m), (2n+2, 2m), (2n, 2m-2), and (2n, 2m+2) using a weight mu^(2). In diagram (b), 'Update step in the presence of breakpoints on a neighbouring arc', a red 'X' marks a breakpoint (BRK) on the arc between (2n, 2m) and (2n+2, 2m). The update for the central node is now based on the node at (2n-2, 2m) and the node at (2n, 2m+2).](9ff1b32449ea068bba9647d71904bd59_img.jpg)
+
+a) Update step in the absence of breakpoints
+
+b) Update step in the presence of breakpoints on a neighbouring arc
+
+Figure 23: Phase 2 update step for (even, even) location (2n, 2m). The figure consists of two diagrams, (a) and (b), showing a 5x5 grid of nodes. The horizontal axis is labeled with 2n-2, 2n, and 2n+2. The vertical axis is labeled with 2m-2, 2m, and 2m+2. In diagram (a), 'Update step in the absence of breakpoints', the central node (2n, 2m) is updated from its four immediate neighbors (2n-2, 2m), (2n+2, 2m), (2n, 2m-2), and (2n, 2m+2) using a weight mu^(2). In diagram (b), 'Update step in the presence of breakpoints on a neighbouring arc', a red 'X' marks a breakpoint (BRK) on the arc between (2n, 2m) and (2n+2, 2m). The update for the central node is now based on the node at (2n-2, 2m) and the node at (2n, 2m+2).
+
+BRK      breakpoint locations
+
+Figure 23 – Phase 2 update step for (even, even) location  $(2n, 2m)$
+
+![Figure 24 – Phase 2 predict step examples. The figure contains two diagrams, (a) and (b), showing a 3x3 grid of vertices. The vertices are labeled with coordinates: top row (2n, 2n+1, 2n+2), middle row (2m, 2m+1, 2m+2), and bottom row (2n+1, 2n+2). Diagram (a) shows the predict step in the absence of breakpoints. It features red solid arrows forming a grid, and blue dashed arrows representing prediction paths. Labels 1/2 are placed on the dashed arrows. Diagram (b) shows the predict step in the presence of breakpoints. A red 'X' labeled 'BRK' is on the top-right edge. The prediction paths and labels are similar to (a). A legend at the bottom left indicates 'BRK' and 'breakpoint locations'. A reference 'T.816(23)' is at the bottom right.](7f5df81190b8dc50dad2604562ae0715_img.jpg)
+
+a) Predict step in the absence of breakpoints
+
+b) Predict step in the presence of breakpoints
+
+BRK      breakpoint locations
+
+T.816(23)
+
+Figure 24 – Phase 2 predict step examples. The figure contains two diagrams, (a) and (b), showing a 3x3 grid of vertices. The vertices are labeled with coordinates: top row (2n, 2n+1, 2n+2), middle row (2m, 2m+1, 2m+2), and bottom row (2n+1, 2n+2). Diagram (a) shows the predict step in the absence of breakpoints. It features red solid arrows forming a grid, and blue dashed arrows representing prediction paths. Labels 1/2 are placed on the dashed arrows. Diagram (b) shows the predict step in the presence of breakpoints. A red 'X' labeled 'BRK' is on the top-right edge. The prediction paths and labels are similar to (a). A legend at the bottom left indicates 'BRK' and 'breakpoint locations'. A reference 'T.816(23)' is at the bottom right.
+
+Figure 24 – Phase 2 predict step examples
+
+# 9 Decoding of breakpoint code-blocks
+
+## 9.1 Embedded bit-plane decoding of breakpoints
+
+Breakpoint code-blocks are decoded progressively, following a sequence of coding passes, each associated with a particular bit-plane in the binary representation of possible vertices  $V_b$ . Similar to the block decoding algorithm described in Rec. ITU-T T.800 | ISO/IEC 15444-1, there are three coding passes per bit-plane and each arc within a code-block has an associated binary state variable  $\sigma_b$ , called its significance state. Significance states are initialized to 0 (insignificant) and may become 1 (significant) during the course of the decoding of the code-block. A significant arc is one that contains a vertex. The coding passes employed in breakpoint decoding are classified as follows:
+
+- Pass-0: Position refinement coding pass
+- Pass-1: Non-root significance coding pass
+- Pass-2: Root significance coding pass
+
+The maximum number of bit-planes for a code-block is the value  $M_b$ , as specified in Rec. ITU-T T.800 | ISO/IEC 15444-1. Decoding proceeds from the most significant bit-plane  $p = p_{\max}$ , down to the least significant bit-plane  $p = 0$ , where
+
+$$p_{\max} = M_b - 1 - P$$
+
+and  $P$  is the number of missing most significant bit-planes (or zero bit-planes), as specified in Rec. ITU-T T.800 | ISO/IEC 15444-1. Decoding starts from Pass-1 in bit-plane  $p_{\max}$ , followed by Pass-2, proceeding to Pass-0 in bit-plane  $p_{\max} - 1$ , and so forth, so that the maximum number of coding passes for the code-block is  $3p_{\max} + 2 = 3(M_b - P) - 1$ .
+
+NOTE 1 – This maximum number of coding passes is one more than the corresponding value for non-breakpoint code-blocks, as described in Rec. ITU-T T.800 | ISO/IEC 15444-1.
+
+Each decoding pass visits a defined subset of the arcs within the code-block, decoding new information for that arc for the relevant bit-plane  $p$ . Pass-1 (non-root significance coding) visits only the non-root arcs that are not yet significant. Pass-2 (root significance coding) visits only root arcs that are not yet significant. Pass-0 (position refinement) visits all arcs in the code-block that have been found significant in a previous (more significant) bit-plane, except those that have been found to hold induction blocks or whose vertex position cannot be refined any further, as explained below.
+
+For code-blocks in the LL sub-band of a breakpoint tile-component, all arcs are considered to be root arcs, so that Pass-1 has no members at resolution  $r = 0$ .
+
+All coding passes employ the MQ binary arithmetic decoding procedures defined in Rec. ITU-T T.800 | ISO/IEC 15444-1, together with a set of contexts that are specific to the coding pass and breakpoint configuration type (QuadBPT or TriBPT, as appropriate).
+
+In significance coding passes, a binary significance symbol is decoded for each member arc  $b$ , which becomes the arc's new significance state  $\sigma_b$ . If this leaves  $\sigma_b = 1$ , additional symbols are decoded, as required, to determine the break-type  $t_b$  and the most significant bit  $m_b$  of any vertex  $V_b$  for the arc. Specific details of these decoding steps are provided in 9.4 and 9.5. A newly significant vertex is assigned type  $t_b = 3$ , precision  $P_b = 2$  and vertex value  $V_b = m_b$ , while a newly discovered induction block is assigned  $t_b = 0$  and  $P_b = 1$ , as explained in 7.5.
+
+A vertex that first becomes significant in bit-plane  $p$  is also assigned a priority indicator  $q_b$  that is equal to  $M_b - 1 - p$ . The value of  $q_b$  is thus 0 if the vertex becomes significant in the highest (earliest) possible bit-plane  $M_b - 1$ . In general, the larger the value of  $q_b$ , the less significant the vertex was considered to be during encoding. In the intra-band decoding mode, the value of  $q_b$  is purely informative, but in the inter-band decoding mode,  $q_b$  is used to form decoding contexts for code-blocks in higher resolutions, as explained in 9.2.
+
+The refinement coding passes are governed by a *termination counter*  $\tau_b$  that identifies the maximum number of refinement symbols that can be decoded for arc  $b$ . Induction blocks are immediately assigned  $\tau_b = 0$  (refinement terminated immediately), because they have no position information that can be refined. For each arc  $b$  with  $\sigma_b = 1$  and  $\tau_b > 0$ , an "early termination" symbol is decoded to determine whether or not  $\tau_b$  should become 0 (refinement terminated); in this case, no refinement symbol  $r_b$  is decoded. If not terminated, a refinement symbol  $r_b$  is decoded, the termination counter  $\tau_b$  is decremented, and the break-precision and vertex value for the arc are updated as follows (a refinement step):
+
+$$P_b := P_b + 1 \text{ and } V_b := 2V_b + r_b$$
+
+NOTE 2 – The number of bits in a vertex value  $V_b$  is always  $P_b - 1$ . The break-precision  $P_b$  can be understood as the precision of the non-zero value  $2V_b + 1$ , from which the tick-point position is recovered according to Formula (8).
+
+Each breakpoint tile-component has an associated integer parameter  $F_{\text{vtx}} \geq 1$  that determines the maximum precision of a decoded vertex. Specifically, each  $P_b$  shall satisfy
+
+$$P_b \leq d + F_{\text{vtx}},$$
+
+where  $d = N_L + 1 - r$ . This means that arc  $b$  can be subjected to at most  $d + F_{\text{vtx}} - 2$  refinement steps, and so the termination counter  $\tau_b$  for each arc  $b$  in a code-block is initialized prior to any decoding steps according to:
+
+$$\tau_b = d + F_{\text{vtx}} - 2$$
+
+Note that when  $d$  and  $F_{\text{vtx}}$  take their minimum values of 1, all arcs are initialized with  $\tau_b = 0$  and so no significant arc can be refined at all – the refinement pass will be empty in this case.
+
+$F_{\text{vtx}}$  and  $F_b$  play closely related roles, with  $F_{\text{vtx}}$  constraining the precision of coded vertices and  $F_b$  constraining the precision of break locations on an arc. These quantities shall satisfy
+
+$$1 \leq F_{\text{vtx}} \leq F_b$$
+
+NOTE 3 – The precision and value of a decoded vertex do not inherently depend upon the bit-plane in which the arc is first found to be significant, and the same is true for induction blocks. However, if only some of the coding passes are decoded, the break-precision and even the significance of arcs that first become significant in later bit-planes are most strongly affected. Thus, encoders can be expected to arrange for arcs whose breakpoint information is more important to become significant in earlier bit-planes. This is discussed further in B.3, which provides an informative description of a breakpoint media format that can preserve the importance of breakpoint information on an arc  $b$  through a quality value  $Q_b$ . Encoders can use  $Q_b$  to determine the bit-plane in which an arc should first become significant, while decoders can recover the value of  $Q_b$  by taking note of the bit-plane in which the arc first becomes significant.
+
+After all decoding passes have been performed, the vertex value  $V_b$  of a significant arc is converted to a tick-point location  $k_b$  using Formula (8).
+
+## 9.2 Inter-band coding mode (BPT\_INTER)
+
+This Recommendation | International Standard describes two different modes for breakpoint coding, known as "intra-band coding" and "inter-band coding." In the intra-band coding mode, corresponding to  $\text{BPT\_INTER} = 0$ , each decoding pass depends only upon state information produced by previous decoding steps within the same code-block. In the inter-band coding mode, corresponding to  $\text{BPT\_INTER} = 1$ , significance information, denoted  $\sigma'_b(p)$ , is imported for each non-root arc in the code-block from the breakpoint component's next lower resolution, if there is one. The imported information  $\sigma'_b(p) = 1$  if the parent arc  $b'$  in the lower resolution has  $t_{b'} = 3$  and  $q_{b'} \leq M_b - 1 - p$ . Otherwise,  $\sigma'_b(p) = 0$ . That is,  $\sigma'_b(p) = 1$  if the parent arc  $b'$  was coded as a significant vertex (not an induction block) at the same point or an earlier point than the current bit-plane  $p$ , where "earlier" is assessed in terms of the priority value  $q_{b'}$ , which indicates how far beyond the first possible bit-plane for a code-block the vertex was first coded as significant.
+
+NOTE 1 – The value of  $\sigma'_b(p)$  depends on the bit-plane  $p$  for which significance decoding is being performed within a code-block. As  $p$  decreases between successive significance decoding passes for an arc, the value of  $\sigma'_b(p)$  can increase from 0 to 1, but not decrease.
+
+If there is no lower resolution, or  $\text{BPT\_INTER} = 0$ ,  $\sigma'_b(p)$  is taken to be 0 for all  $p$ . Otherwise, significance decoding within bit-plane  $p$  is only possible if the code-block or code-blocks that contain all of the block's parent arcs in the lower resolution have either been completely decoded or have been decoded at least to the bit-plane  $p + M_{b'} - M_b$ .
+
+That is, for each parent arc  $b'$ ,  $\sigma'_b(p)$  can be evaluated in the block decoder only if  $b'$  has been subjected to significance decoding in bit-plane  $p + M_{b'} - M_b$ , where  $M_{b'}$  is the maximum number of bit-planes for the parent resolution, as specified in Rec. ITU-T T.800 | ISO/IEC 15444-1, except in the case where all originally encoded bit-planes for the parent
+
+arc are known to have been decoded. A decoder can deduce whether or not all originally encoded bit-planes have been decoded for a code-block from the zero-completeness and pass-completeness information recovered during packet header decoding, as described in 9.6.
+
+NOTE 2 – The second condition above, related to the decoding of all originally encoded bit-planes, arises because an encoder is not obliged to produce all possible  $M_{b'}$  bit-planes for the code-block containing parent arc  $b'$ . Encoders can terminate their encoding process early, in which case a decoder that has decoded all encoded content can be sure that it can reconstruct all inter-band conditioning information  $\sigma_b(p)$  that was used by the encoder.
+
+## 9.3 Cell-based scanning patterns and CBAP-based block flipping
+
+As explained in 7.3, code-blocks of breakpoint components are associated with arrays of  $2 \times 2$  cells, consisting of  $H_{\text{blk}}$  cell rows, with  $W_{\text{blk}}$  cells on each row. For all LL band coding passes, and for the position refinement passes of CL band code-blocks cells are scanned in raster order.
+
+For CL band code-blocks, however, the non-root and root significance coding passes employ a different scanning pattern that involves scanning through  $2 \times 2$  groups of  $2 \times 2$  cells. For QuadBPT components, the CL band significance coding passes scan groups in raster order, scanning the cells within each group also in raster order, as illustrated in Figure 25. Only those cells of a group that are actually contained within the code-block are visited in this scanning pattern.
+
+![Figure 25: Canonical scanning pattern for CL band code-blocks in a QuadBPT component. The diagram shows a grid of 2x2 cell groups. Each group is a 2x2 grid of cells. Red arrows indicate the scanning path: within each group, cells are scanned in raster order (top-left to top-right, then bottom-left to bottom-right). Groups are scanned in raster order across the grid. A long red arrow shows the transition from the last group of the first row to the first group of the second row. Some cells are missing (represented by empty squares), and the scanning path skips them.](107da2e3495b2f24352c9e3b26ec4841_img.jpg)
+
+T.816(23)
+
+Figure 25: Canonical scanning pattern for CL band code-blocks in a QuadBPT component. The diagram shows a grid of 2x2 cell groups. Each group is a 2x2 grid of cells. Red arrows indicate the scanning path: within each group, cells are scanned in raster order (top-left to top-right, then bottom-left to bottom-right). Groups are scanned in raster order across the grid. A long red arrow shows the transition from the last group of the first row to the first group of the second row. Some cells are missing (represented by empty squares), and the scanning path skips them.
+
+**Figure 25 – Canonical scanning pattern used for the significance coding passes of CL band code-blocks in a QuadBPT component. In this case, missing cells within a  $2 \times 2$  group are not included in the scan**
+
+For TriBPT components, each group within a CL band code-block represents a single 4-span; the groups are visited in raster order, and decoding procedures are described directly in terms of the arcs within each 4-span, rather than on a cell by cell basis. Each group in this case is considered to have 12 TriBPT arcs, regardless of whether or not all cells of the group are contained within the code-block. The scanning patterns for TriLR and TriRL breakpoint configurations are shown in Figure 26 and Figure 27, respectively, providing labels for each of the 12 arcs of each 4-span group. Notice that the TriLR and TriRL cases are substantially similar, except that the locations of root (DR1 and DR2) and non-root (NR1 and NR2) diagonal arcs change.
+
+![Figure 26: Canonical scanning pattern for TriLR components. The diagram shows two rows of four 2x2 grids each. Each grid contains four cells with labels: top-left (VN1, HN1, DN1), top-right (VR1, HN2, DR1), bottom-left (VN2, HR1, DR2), and bottom-right (VR2, HR2, DN2). Red arrows indicate the scanning path within each cell. A purple arrow connects the end of the first row to the start of the second row, indicating a row-wise scanning pattern.](70a863dc6cd47bac82c12162a9479aac_img.jpg)
+
+Figure 26: Canonical scanning pattern for TriLR components. The diagram shows two rows of four 2x2 grids each. Each grid contains four cells with labels: top-left (VN1, HN1, DN1), top-right (VR1, HN2, DR1), bottom-left (VN2, HR1, DR2), and bottom-right (VR2, HR2, DN2). Red arrows indicate the scanning path within each cell. A purple arrow connects the end of the first row to the start of the second row, indicating a row-wise scanning pattern.
+
+T.816(23)
+
+**Figure 26 – Canonical scanning pattern used for the significance coding passes of CL band code-blocks in TriLR components. Arcs belonging to cells that lie beyond the code-block boundaries are included in the significance coding passes**
+
+![Figure 27: Canonical scanning pattern for TriRL components. The diagram shows two rows of four 2x2 grids each. Each grid contains four cells with labels: top-left (VN1, HN1, DR1), top-right (VR1, HN2, DN1), bottom-left (VN2, HR1, DN2), and bottom-right (VR2, HR2, DR2). Red arrows indicate the scanning path within each cell. A purple arrow connects the end of the first row to the start of the second row, indicating a row-wise scanning pattern.](13fde41de77bf026013a0b81684d1fc9_img.jpg)
+
+Figure 27: Canonical scanning pattern for TriRL components. The diagram shows two rows of four 2x2 grids each. Each grid contains four cells with labels: top-left (VN1, HN1, DR1), top-right (VR1, HN2, DN1), bottom-left (VN2, HR1, DN2), and bottom-right (VR2, HR2, DR2). Red arrows indicate the scanning path within each cell. A purple arrow connects the end of the first row to the start of the second row, indicating a row-wise scanning pattern.
+
+T.816(23)
+
+**Figure 27 – Canonical scanning pattern used for the significance coding passes of CL band code-blocks in TriRL components. Arcs belonging to cells that lie beyond the code-block boundaries are included in the significance coding passes**
+
+These various scanning patterns all have geometric variants that correspond to different values of the CBAP coordinates  $(z_x, z_y)$ . If the CBAP coordinate  $z_x = 1$ , groups and cells are scanned from right to left instead of left to right, and groups are aligned with the right edge of the code-block, so that there might be missing cells on the left but not the right edge of a block for which  $W_{\text{blk}}$  is odd. Similarly, if  $z_y = 1$ , groups and cells are scanned from bottom to top, rather than from top to bottom, and groups are aligned with the lower edge of the code-block.
+
+Equivalently, all block decoding operations can be performed by following the *canonical scan* associated with  $z_x = z_y = 0$ , after which the decoded breakpoint data for the code-block is flipped horizontally if  $z_x = 1$  and flipped vertically if  $z_y = 1$ . In this clause, all block decoding procedures are described from this *canonical decoding* point of view, assuming that the horizontal and vertical flipping operations will be performed as required, as a post-processing step.
+
+The canonical decoding procedures, that involve only the canonical scan, involve cells whose upper-left corner always corresponds to a grid-point with even-valued coordinates. Figure 1 shows the arcs for which breakpoint information is decoded within any given cell in the canonical scan, along with their relationships to the grid-points of the cell. For TriBPT code-blocks in CL bands, the canonical decoding procedures involve groups whose upper-left corner always corresponds to a grid-point whose coordinates are divisible by 4, meaning that each group corresponds to an aligned 4-span. These alignment constraints follow from the constraints on precinct size parameters PPx and PPy found in Table 1.
+
+NOTE 1 – To appreciate the significance of this, observe that the vertical and horizontal arcs associated with the top-left cell in the canonical scan both terminate at the top left grid-point in the code-block, while no arcs can terminate at the bottom right grid-point in the code-block. If the CBAP coordinates are  $(z_x, z_y) = (1, 1)$ , so that the arc breakpoint data is flipped horizontally and vertically after canonical decoding, the top left canonical cell's arcs ultimately terminate at the bottom right corner of the code-block, while no arcs terminate at the top left corner of the block.
+
+As already explained, it can happen that the canonical decoding steps need to be followed by horizontal or flipping operations, depending on the CBAP coordinates  $(z_x, z_y)$ . To be more precise, horizontal flipping ( $z_x = 1$ ), involves the following steps:
+
+- The breakpoint data for an arc centred on a grid-point in column  $c$  of the canonical decoded result, is moved to the arc centred at the corresponding grid-point in column  $2W_{\text{blk}} - 1 - c$  in the flipped result, where  $c = 0$  corresponds to the left edge of the code-block.
+- The tick-point value  $k_b$  of any break on a horizontal or diagonal arc is converted to a tick-point value  $2^{d+FB} - 1 - k_b$ .
+
+Similarly, vertical flipping ( $z_y = 1$ ), involves the following steps:
+
+- The breakpoint data for an arc centred on a grid-point in row  $r$  of the canonical decoded result, is moved to the arc centred at the corresponding grid-point in row  $2H_{\text{blk}} - 1 - r$  in the flipped result, where  $r = 0$  corresponds to the top edge of the code-block.
+- The tick-point value  $k_b$  of any break on a vertical or diagonal arc is converted to a tick-point value  $2^{d+FB} - 1 - k_b$ .
+
+If horizontal and vertical flipping are both required ( $z_x = z_y = 1$ ), then both of the conversions described above are applied and the order of application is not important.
+
+NOTE 2 – The  $k_b$  conversions for diagonal arcs cancel each other when  $(z_x = z_y = 1)$ .
+
+Flipping in either direction also causes a change in geometry for code-blocks belonging to one of the TriBPT components, from TriBPT-LR to TriBPT-RL and from TriBPT-RL to TriBPT-LR. These geometry changes cancel when  $z_x = z_y = 1$ . If, however,  $z_x \neq z_y$ , the canonical decoding of code-blocks that belong to a TriBPT-LR component shall be performed as if the component had the TriBPT-RL geometry, and vice-versa.
+
+## 9.4 QuadBPT decoding procedures
+
+### 9.4.1 MQ Coder contexts and initial states for QuadBPT decoding
+
+Up to 33 different MQ coder contexts are used for decoding QuadBPT CL band code-blocks. Table 2 lists all context labels, along with the initial states for each context. Up to 6 contexts are used for non-root arc significance decoding, the last of these being a special "PARENT" context that is used only in the inter-band coding mode (BPT\_INTER = 1). Nine contexts are used for root arc significance and induction block decoding. Sixteen contexts are used for the skip symbols used to identify the point at which magnitude refinement is skipped, if any, while just one context is used for magnitude refinement itself. Finally, a uniform context is provided for use with a run mode that plays the same role as the run mode used for significance decoding of non-breakpoint components in Rec. ITU-T T.800 | ISO/IEC 15444-1.
+
+For LL band code-blocks, decoding procedures are much simpler, using only a subset of the context labels shown in Table 2 and with different interpretations, but the same initial state values. The LL band context labels and their usage are provided in Table 3.
+
+**Table 2 – MQ coder contexts for QuadBPT CL code-block decoding passes. State index values correspond to the Qe values and probability estimation transitions tabulated in Rec. ITU-T T.800 | ISO/IEC 15444-1**
+
+| Usage in CL band code-blocks         | Context label(s) | Initial state index        |                   |
+|--------------------------------------|------------------|----------------------------|-------------------|
+|                                      |                  | MQ probability state index | Initial MPS value |
+| Non-root significance NO-ODD         | 0                | 42                         | 0                 |
+| Non-root significance ANY-ODD-OLD    | 1                | 40                         | 0                 |
+| Non-root significance ONE-ODD-NEW    | 2                | 4                          | 0                 |
+| Non-root significance TWO-ODD-NEW    | 3                | 3                          | 0                 |
+| Non-root significance RUN            | 4                | 42                         | 0                 |
+| Non-root significance PARENT         | 5                | 28                         | 0                 |
+| Root pair significance INSIG         | 6                | 38                         | 0                 |
+| Root pair significance ANY-SIG-OLD   | 7                | 40                         | 0                 |
+| Root pair significance ONE-SIG-NEW   | 8                | 4                          | 0                 |
+| Root pair significance MULTI-SIG-NEW | 9                | 4                          | 0                 |
+| Root pair significance RUN           | 10               | 44                         | 0                 |
+| Root pair induction block            | 11-12            | 0                          | 0                 |
+| Root significance PRIMARY-DIR        | 13               | 0                          | 0                 |
+| Root significance SECONDARY-DIR      | 14               | 0                          | 0                 |
+| Magnitude bit                        | 15               | 0                          | 0                 |
+| Magnitude refinement TERMINATE       | 16-31            | 40                         | 0                 |
+| UNIFORM                              | 32               | 46                         | 0                 |
+
+**Table 3 – Context labels from Table 2 that are used for QuadBPT LL code-block decoding passes**
+
+| Usage in LL band code-blocks   | Context label(s) | Initial state index (unchanged from Table 2) |                   |
+|--------------------------------|------------------|----------------------------------------------|-------------------|
+|                                |                  | MQ probability state index                   | Initial MPS value |
+| Significance flag decoding     | 1                | 40                                           | 0                 |
+| Vertex flag decoding           | 2                | 4                                            | 0                 |
+| Direct flag decoding           | 3                | 3                                            | 0                 |
+| Degenerate flag decoding       | 4                | 42                                           | 0                 |
+| Magnitude bit                  | 15               | 0                                            | 0                 |
+| Magnitude refinement TERMINATE | 16-31            | 40                                           | 0                 |
+| UNIFORM                        | 32               | 46                                           | 0                 |
+
+### 9.4.2 Derivation of context labels for QuadBPT CL band significance coding passes
+
+Context labels employed when processing a (current) 2x2 cell during any of the CL band significance decoding passes are derived using a context neighbourhood that is depicted in Figure 28. In this figure, the root arcs of the current cell are denoted "CV" and "CH", while its non-root arcs are denoted "NV" and "NH". Significance decoding contexts are formed using the significance of additional non-root arcs from neighbouring cells. These neighbouring cells are above (top neighbour), above and to the right (top-right neighbour), to the left (left neighbour), to the right (right neighbour), below (bottom neighbour) and below and to the left (bottom-left neighbour). The relevant non-root arcs are denoted "TV", "TH", "TRV", "LV", "LH", "RV", "BH" and "BLH", respectively. If any of these neighbouring cells lies outside the bounds of the code-block then its arcs are considered to be insignificant for the purpose of context formation.
+
+![Figure 28: Neighbouring cells and arcs involved in forming coding contexts for QuadBPT significance decoding in CL band code-blocks. The diagram shows a grid of nodes (blue circles) and arcs (red lines) forming a 4x4 grid. The nodes are labeled with red text: LH, NH, TH, LV, NV, TV, BLH, BH, TRV, CV, RV. The arcs are labeled with red text: LH, NH, TH, LV, NV, TV, BLH, BH, TRV, CV, RV. The diagram is divided into four colored regions: a yellow region on the left, a light blue region on the right, a light green region in the center, and a light orange region at the bottom. The nodes are arranged in a grid, with the central node (NV) being the focus of the context formation. The arcs connect the nodes in a grid pattern, with some arcs being highlighted in red. The diagram is labeled T.816(23) in the bottom right corner.](b05bae46f7079e5c9b1da38adb2319e8_img.jpg)
+
+Figure 28: Neighbouring cells and arcs involved in forming coding contexts for QuadBPT significance decoding in CL band code-blocks. The diagram shows a grid of nodes (blue circles) and arcs (red lines) forming a 4x4 grid. The nodes are labeled with red text: LH, NH, TH, LV, NV, TV, BLH, BH, TRV, CV, RV. The arcs are labeled with red text: LH, NH, TH, LV, NV, TV, BLH, BH, TRV, CV, RV. The diagram is divided into four colored regions: a yellow region on the left, a light blue region on the right, a light green region in the center, and a light orange region at the bottom. The nodes are arranged in a grid, with the central node (NV) being the focus of the context formation. The arcs connect the nodes in a grid pattern, with some arcs being highlighted in red. The diagram is labeled T.816(23) in the bottom right corner.
+
+**Figure 28 – Neighbouring cells and arcs involved in forming coding contexts for QuadBPT significance decoding in CL band code-blocks**
+
+Significance coding contexts for the non-root arcs "NV" and "NH" depend on four "cupping" values, each of which describe the significance of the non-root neighbouring arcs that "cup" each side of the non-root arc being decoded, taking values of 0, 1, 2 or 3. Specifically, writing
+
+$$\bar{\sigma}_b(p) = \sigma_b \mid \sigma'_b(p)$$
+
+for the inclusive OR of an arc  $b$ 's significance  $\sigma_b$  and its inter-band significance  $\sigma'_b(p)$  for the current bit-plane  $p$ , the "NV" non-root arc has cupping context values
+
+$$\text{CUP}_{\text{left}} = \bar{\sigma}_{\text{LH}}(p) + \bar{\sigma}_{\text{LV}}(p) + \bar{\sigma}_{\text{BLH}}(p)$$
+
+and
+
+$$\text{CUP}_{\text{right}} = \bar{\sigma}_{\text{NH}}(p) + \bar{\sigma}_{\text{RV}}(p) + \bar{\sigma}_{\text{BH}}(p)$$
+
+Meanwhile, the "NH" non-root arc has cupping values
+
+$$\text{CUP}_{\text{top}} = \bar{\sigma}_{\text{TV}}(p) + \bar{\sigma}_{\text{TH}}(p) + \bar{\sigma}_{\text{TRV}}(p)$$
+
+and
+
+$$\text{CUP}_{\text{bottom}} = \bar{\sigma}_{\text{NV}}(p) + \bar{\sigma}_{\text{BH}}(p) + \bar{\sigma}_{\text{RV}}(p)$$
+
+Significance coding contexts for the non-root arcs "NV" and "NH" also depend on two binary "life" state variables, denoted  $\text{LIFE}_{\text{nv}}$  and  $\text{LIFE}_{\text{nh}}$ , that are initialized to 0 before decoding for the code-block commences.  $\text{LIFE}_{\text{nv}}$  is equal to 1 if only if the value of  $\text{CUP}_{\text{left}}$  or  $\text{CUP}_{\text{right}}$  has increased since the last significance decoding step for non-root arc NV. This property is achieved by setting  $\text{LIFE}_{\text{nv}}$  to 1 after any significance decoding step which leaves any of the arcs contributing to  $\text{CUP}_{\text{left}}$  or  $\text{CUP}_{\text{right}}$  newly significant and then resetting  $\text{LIFE}_{\text{nv}}$  to 0 after each significance decoding step for NV itself. Similarly,  $\text{LIFE}_{\text{nh}}$  is equal to 1 if and only if the value of  $\text{CUP}_{\text{top}}$  or  $\text{CUP}_{\text{bottom}}$  has increased since the last significance decoding step for non-root arc NH.
+
+In the inter-band coding mode (BPT\_INTER = 1), an increase in cupping values can occur due to a change in any of the  $\sigma'_b(p)$  values involved in the construction of that cupping value, in comparison to  $\sigma'_b(p+1)$ , unless arc  $b$  was already significant in an earlier coding pass. To clarify this point, a decoder can correctly incorporate the inter-band coding mode by recomputing all  $\sigma'_b(p)$  values immediately before the first significance decoding pass for a bit-plane  $p$ , updating all cupping values accordingly, and setting life state variables to 1 if any of the relevant cupping values increases in this process.
+
+The significance context label from Table 2 for non-root arc "NV" or "NH" is derived from these quantities as
+
+$$\kappa_{\text{nv}}^{\text{qbpt}} = \text{KAPPA}_{\text{nr}}^{\text{qbpt}}(\text{CUP}_{\text{left}}, \text{CUP}_{\text{right}}, \text{LIFE}_{\text{nv}}, \sigma'_{\text{NV}}(p))$$
+
+and
+
+$$\kappa_{nh}^{qbpt} = \text{KAPPA}_{nrt}^{qbpt}(\text{CUP}_{top}, \text{CUP}_{bottom}, \text{LIFE}_{nh}, \sigma'_{NH}(p)),$$
+
+where function  $\text{KAPPA}_{nrt}^{qbpt}$  is defined as follows
+
+$$\text{KAPPA}_{nrt}^{qbpt}(C_0, C_1, L, \sigma') = \begin{cases} 0 & \text{if } \sigma' = 0, \text{MOD}(C_0, 2) + \text{MOD}(C_1, 2) = 0 \\ 1 & \text{if } \sigma' = 0, L = 0, \text{ and } \text{MOD}(C_0, 2) + \text{MOD}(C_1, 2) \neq 0 \\ 2 & \text{if } \sigma' = 0, L = 1, \text{ and } \text{MOD}(C_0, 2) + \text{MOD}(C_1, 2) = 1 \\ 3 & \text{if } \sigma' = 0, L = 1, \text{ and } \text{MOD}(C_0, 2) + \text{MOD}(C_1, 2) = 2 \\ 5 & \text{if } \sigma' = 1 \end{cases}$$
+
+Here,  $\text{MOD}(C, 2)$  is equal to 0 if  $C \in \{0, 2\}$  and 1 if  $C \in \{1, 3\}$ .
+
+NOTE 1 – The  $\text{KAPPA}_{nrt}^{qbpt}$  function returns one of the context labels 0 through 3 or else 5 (in inter-band coding mode). Context label 4 from Table 2 is used for RUN symbol decoding, which is explained in 9.4.3.
+
+Root arc significance decoding is performed jointly on the CH/CV arc pair. The MQ coding context for root arc significance decoding is formed using the significance of the neighbouring non-root arcs NV, NH, RV and BH shown in Figure 28. Specifically, horizontal and vertical significant boundary count variables are formed as
+
+$$\text{CNT}_{bv} = \bar{\sigma}_{RV}(p) + \bar{\sigma}_{NV}(p)$$
+
+and
+
+$$\text{CNT}_{bh} = \bar{\sigma}_{BH}(p) + \bar{\sigma}_{NH}(p)$$
+
+Additionally, a binary "life" state variable  $\text{LIFE}_{root}$  is employed to derive the MQ coding context for significance decoding of each CH/CV root arc pair. Similar to the other "life" state variables,  $\text{LIFE}_{root}$  is initialized to 0, set to 1 if either of  $\text{CNT}_{bv}$  or  $\text{CNT}_{bh}$  has increased since the last significance decoding step for the CH/CV root arc pair, and is reset to 0 after each significance decoding step for the root arc pair.
+
+As with the other life state variables, a decoder can correctly incorporate the inter-band coding mode ( $\text{BPT\_INTER} = 1$ ) by recomputing all  $\sigma'_b(p)$  values immediately before the first significance decoding pass for a bit-plane  $p$ , updating all significant boundary counts  $\text{CNT}_{bv}$  and  $\text{CNT}_{bh}$  accordingly, and setting  $\text{LIFE}_{root}$  to 1 if either of the associated boundary counts increases in this process.
+
+From these three quantities, the root arc pair significance context label  $\kappa_{root}^{qbpt}$  from Table 2 is formed from
+
+$$\kappa_{root}^{qbpt} = 6 + \begin{cases} 0 & \text{if } (\text{CNT}_{bv} + \text{CNT}_{bh}) = 0 \\ 1 & \text{if } (\text{CNT}_{bv} + \text{CNT}_{bh}) \neq 0 \text{ and } \text{LIFE}_{root} = 0 \\ 2 & \text{if } (\text{CNT}_{bv} + \text{CNT}_{bh}) = 1 \text{ and } \text{LIFE}_{root} = 1 \\ 3 & \text{if } (\text{CNT}_{bv} + \text{CNT}_{bh}) \geq 2 \text{ and } \text{LIFE}_{root} = 1 \end{cases}$$
+
+The quantities  $\text{CNT}_{bv}$  and  $\text{CNT}_{bh}$  are used to derive two other important quantities for significance decoding of root arcs CH and CV. The first of these is the context label  $\kappa_{iblock}^{qbpt}$  that is used to decode an induction block symbol for a root arc pair that has just become significant. This label is found from
+
+$$\kappa_{iblock}^{qbpt} = \begin{cases} 11 & \text{if } \text{CNT}_{bh} + \text{CNT}_{bv} = 2 \\ 12 & \text{otherwise} \end{cases}$$
+
+The second quantity derived from  $\text{CNT}_{bv}$  and  $\text{CNT}_{bh}$  is a primary direction label
+
+$$D_{root}^{qbpt} = \begin{cases} 0 & \text{if } \text{CNT}_{bh} \geq \text{CNT}_{bv} \\ 1 & \text{if } \text{CNT}_{bh} < \text{CNT}_{bv} \end{cases}$$
+
+which identifies whether the significance of CH ( $D_{root}^{qbpt} = 0$ ) or CV ( $D_{root}^{qbpt} = 1$ ) is decoded first, once a root-arc pair has been found to be significant and not an induction block.
+
+NOTE 2 – The root significance coding context labels defined above take values from 6 through 9 and 11 through 14. Context label 10 from Table 2 is used for RUN symbol decoding, which is explained in 9.4.4.
+
+### 9.4.3 Non-root significance decoding for QuadBPT CL code-blocks
+
+The non-root significance decoding pass for bit-plane  $p$  within a QuadBPT CL band code-block processes groups of  $2 \times 2$  cells in raster order, as shown in Figure 25. For each such cell group, the decoder enters a special "RUN mode" if all cells in the group are found to have entirely insignificant context. A cell's context is entirely insignificant if the cell's four cupping values  $\text{CUP}_{left}$ ,  $\text{CUP}_{right}$ ,  $\text{CUP}_{top}$  and  $\text{CUP}_{bottom}$  are all 0, and its root arcs CH and CV are also insignificant. Equivalently, a cell's context is entirely insignificant if all of the labelled arcs  $b$  shown in Figure 28 have  $\sigma_b = 0$  and  $\sigma'_b(p) = 0$ , this second condition being relevant only in the inter-band coding mode. When all cells of the group satisfy this condition, the MQ decoder is invoked with context label  $\kappa = 4$  (non-root significance RUN context – see Table 2) to decode an end-of-run symbol.
+
+If the end-of-run symbol is 0, the entire group remains insignificant and decoding proceeds to the next cell group, if any. If the end-of-run symbol is 1, then at least one of the non-root arcs in at least one of the group's cells is significant. The MQ decoder is then used with context label  $\kappa = 32$  (UNIFORM context – see Table 2) to decode three consecutive symbols  $R_a$ ,  $R_b$  and then  $R_c$ . A cell run-length is formed as  $R = 2R_a + R_b$ , identifying the first cell in the group that contains a significant non-root arc, following the raster order shown in Figure 25. If  $R_c=0$ , decoding continues from the identified cell with flag SKIP\_TO\_NH set to true, meaning that the cell's NV arc is insignificant and the first significant arc of the cell is NH. Otherwise, if  $R_c=1$ , decoding continues from the identified cell with flag SKIP\_TO\_NV set to true, meaning that the cell's NV arc is significant.
+
+After processing the cell identified by run-length  $R$ , any remaining cells in the group are processed in raster order, with flags SKIP\_TO\_NH and SKIP\_TO\_NV both set to false. If a cell group does not have an entirely insignificant context, all of its cells are processed in raster order, with flags SKIP\_TO\_NH and SKIP\_TO\_NV both set to false.
+
+For each cell, the decoder performs decoding steps first for the vertical non-root arc NV and then for the horizontal non-root arc NH. Specifically, if SKIP\_TO\_NH is false and  $\sigma_{NV} = 0$ , the decoder performs the following NV decoding steps:
+
+- V1. If SKIP\_TO\_NV is false, the MQ decoder is invoked with context label  $\kappa_{nv}^{qbpt}$  to decode the SIG symbol; otherwise, the SKIP\_TO\_NV is true, and the decoder sets SIG to 1.
+- V2. If SIG = 1, significance state  $\sigma_{NV}$  is set to 1, the cupping values  $CUP_{left}$ ,  $CUP_{right}$ ,  $CUP_{top}$  and  $CUP_{bottom}$  of all cells that depend on  $\sigma_{NV}$  are updated, and the life values  $LIFE_{nv}$ ,  $LIFE_{nh}$  and  $LIFE_{root}$  of all cells that depend on  $\sigma_{NV}$  are set to 1.
+- V3. If SIG = 1, the MQ decoder is invoked with context label  $\kappa = 15$  (magnitude bit context – see Table 2) to decode the most significant value bit  $m_b$  of the arc  $b=NV$ . Then, the type, precision and value for the arc are set to  $t_b = 3$ ,  $P_b = 2$  and  $V_b = m_b$ .
+- V4. The  $LIFE_{nv}$  state variable for the processed cell itself is reset to 0.
+
+If  $\sigma_{NH} = 0$ , the decoder then performs the following NH decoding steps:
+
+- H1. If SKIP\_TO\_NH is false, the MQ decoder is invoked with context label  $\kappa_{nh}^{qbpt}$  to decode the SIG symbol; otherwise, the SKIP\_TO\_NH is true, and the decoder sets SIG to 1.
+- H2. If SIG = 1, significance state  $\sigma_{NH}$  is set to 1, the cupping values  $CUP_{left}$ ,  $CUP_{right}$ ,  $CUP_{top}$  and  $CUP_{bottom}$  of all cells that depend on  $\sigma_{NH}$  are updated, and the life values  $LIFE_{nv}$ ,  $LIFE_{nh}$  and  $LIFE_{root}$  of all cells that depend on  $\sigma_{NH}$  are set to 1.
+- H3. If SIG = 1, the MQ decoder is invoked with context label  $\kappa = 15$  (magnitude bit context – see Table 2) to decode the most significant value bit  $m_b$  of the arc  $b=NH$ . Then, the type, precision and value for the arc are set to  $t_b = 3$ ,  $P_b = 2$  and  $V_b = m_b$ .
+- H4. The  $LIFE_{nh}$  state variable for the processed cell itself is reset to 0.
+
+### 9.4.4 Root significance decoding for QuadBPT CL code-blocks
+
+The root significance decoding pass for bit-plane  $p$  within a QuadBPT CL band code-block processes groups of 2x2 cells in raster order, as shown in Figure 25. For each such cell group, the decoder enters a special "RUN mode" if all cells in the group are found to have entirely insignificant context. Exactly as in 9.4.3, a cell's context is entirely insignificant if all of the labelled arcs  $b$  shown in Figure 28 have  $\sigma_b = 0$  and  $\sigma'_b(p) = 0$ , this second condition being relevant only in the inter-band coding mode (BPT\_INTER = 1). When all cells of the group satisfy this condition, the MQ decoder is invoked with context label  $\kappa = 15$  (root significance RUN context – see Table 2) to decode an end-of-run symbol.
+
+If the end-of-run symbol is 0, the entire group remains insignificant and decoding proceeds to the next cell group, if any. If the end-of-run symbol is 1, then at least one of the root arcs in at least one of the group's cells is significant. The MQ decoder is then used with context label  $\kappa = 32$  (UNIFORM context – see Table 2) to decode two consecutive symbols  $R_a$  and then  $R_b$ . A cell run-length is formed as  $R = 2R_a + R_b$ , identifying the first cell in the group that contains a significant root arc pair, following the raster order shown in Figure 25. Decoding continues from the identified cell with flag SKIP\_TO\_SIG set to true.
+
+After processing the cell identified by run-length  $R$ , any remaining cells in the group are processed in raster order, with flag SKIP\_TO\_SIG set to false. If a cell group does not have an entirely insignificant context, all of its cells are processed in raster order, with flag SKIP\_TO\_SIG set to false.
+
+For each cell, if  $\sigma_{CV} = 0$  and  $\sigma_{CH} = 0$ , the decoder performs the following steps:
+
+1. If SKIP\_TO\_SIG is false, the MQ decoder is invoked with context label  $\kappa_{root}^{qbpt}$  to decode the SIG symbol; otherwise, the SKIP\_TO\_SIG is true and the decoder sets SIG to 1.
+2. If SIG = 1, the MQ decoder is invoked with context label  $\kappa_{iblock}^{qbpt}$  to decode symbol IBLOCK. If IBLOCK=1, the decoder sets  $\sigma_b = 1$ ,  $t_b = 0$ ,  $P_b = 1$  (induction block) and  $\tau_b = 0$  (not refineable), for both of the root arcs  $b \in \{CV, CH\}$ . Otherwise, IBLOCK=0 and the decoder performs the following sub-steps:
+
+- a. The MQ decoder is invoked with context label  $\kappa = 13$  (PRIMARY-DIR context – see Table 2) to decode symbol SIG. If SIG = 0 flag SKIP\_TO\_SECONDARY is set to true. Otherwise, SKIP\_TO\_SECONDARY is set to false and the MQ decoder is invoked with context label  $\kappa = 15$  (magnitude bit context) to decode the most significant value bit  $m_b$  of the primary root arc  $b$ , setting  $\sigma_b = 1$ ,  $t_b = 3$ ,  $P_b = 2$  and  $V_b = m_b$ , where
+
+$$b = \begin{cases} \text{CH} & \text{if } D_{\text{root}}^{\text{qbpt}} = 0 \\ \text{CV} & \text{if } D_{\text{root}}^{\text{qbpt}} = 1 \end{cases}$$
+
+- b. If SKIP\_TO\_SECONDARY is set to false, the MQ decoder is invoked with context label  $\kappa = 14$  (SECONDARY-DIR context – see Table 2) to decode symbol SIG; otherwise, SKIP\_TO\_SECONDARY is true, and SIG is set to 1.
+- c. If SIG = 1, the MQ decoder is invoked with context label  $\kappa = 15$  (magnitude bit context – see Table 2) to decode the most significant value bit  $m_b$  of the secondary root arc  $b$ , setting  $\sigma_b = 1$ ,  $t_b = 3$ ,  $P_b = 2$  and  $V_b = m_b$ , where
+
+$$b = \begin{cases} \text{CV} & \text{if } D_{\text{root}}^{\text{qbpt}} = 0 \\ \text{CH} & \text{if } D_{\text{root}}^{\text{qbpt}} = 1 \end{cases}$$
+
+3. The LIFE<sub>root</sub> state variable for the processed cell is reset to 0.
+
+### 9.4.5 Root significance decoding for QuadBPT LL code-blocks
+
+The significance decoding pass for bit-plane  $p$  within a QuadBPT LL band code-block processes 2x2 cells in raster order. In the canonical scan, rows of cells are visited from top to bottom, cells of each row are visited from left to right, and the four arcs  $b$  of each cell are visited in the order NV, CV, NH then CH.
+
+For each arc  $b$ , following this scanning order, if  $\sigma_b = 0$ , the MQ decoder is invoked with context label  $\kappa=1$  (significance flag context – see Table 3) to decode symbol SIG. If SIG = 0, arc  $b$  remains insignificant. Otherwise, the following steps are performed:
+
+1. The significance state for arc  $b$  is changed to  $\sigma_b = 1$
+2. The MQ decoder is invoked with context label  $\kappa = 2$  (vertex flag context – see Table 3) to decode symbol VTX.
+3. If VTX = 1, the breakpoint type for arc  $b$  is set to  $t_b = 3$ . Otherwise, the MQ decoder is invoked with context label  $\kappa = 3$  (direct flag context – see Table 3) to decode symbol DIRECT, and the type for arc  $b$  is set to  $t_b = 1 + \text{DIRECT}$ .
+4. VTX = 0, the MQ decoder is invoked with context label  $\kappa = 4$  (degenerate flag context – see Table 3) to decode symbol DEGEN; otherwise DEGEN is set to 0.
+5. If DEGEN = 1, the following steps are performed:
+  - a. The MQ decoder is invoked with context label  $\kappa = 32$  (uniform context – see Table 3) to decode symbol AMBIVALENT.
+  - b. The precision and value parameters for arc  $b$  are set to  $P_b = \text{AMBIVALENT}$  and  $V_b = 0$  and the refinement counter is set to  $\tau_b = 0$  (not refineable).
+6. Otherwise, DEGEN = 0 and the MQ decode is invoked with context label 15 (magnitude bit context) to decode the most significant value bit  $m_b$  of arc  $b$ . Then, the precision and value for the arc are set to  $t_b = 3$ ,  $P_b = 2$  and  $V_b = m_b$ .
+
+NOTE 1 – Coding procedures for LL band code-blocks are intended to be very simple, since in most cases all LL code-blocks are expected to be entirely insignificant. Coding tools are provided for the LL band of a breakpoint component primarily to allow the communication of breaks when  $N_L$  is heavily constrained, or even 0. For example, the breakpoints described by the breakpoint media format suggested in Annex B can be encapsulated directly within the LL band of a breakpoint component with  $N_L = 0$  decomposition levels.
+
+NOTE 2 – No means is provided to identify whether or not an arc without a break might hold an induction block, whereas this information can be recorded (as a hint) within the breakpoint media format suggested in Annex B. Induction blocks play no role in breakpoint dependent transforms and so there is no need to record them within resolution  $r = 0$  of a breakpoint component.
+
+### 9.4.6 Position refinement decoding for QuadBPT code-blocks
+
+Position refinement decoding is the same for CL and LL band code-blocks of a QuadBPT component, using MQ coder context labels 15 through 31 from Table 2 and Table 3, and processing  $2 \times 2$  cells in raster order. In the canonical scan, rows of cells are visited from top to bottom, cells of each row are visited from left to right, and the four arcs  $b$  of each cell are visited in the order NV, CV, NH then CH.
+
+For each arc  $b$ , following this scanning order, if  $\sigma_b = 1$  and  $\tau_b > 0$ , the following steps are performed:
+
+1. The MQ decoder is invoked with context label  $\kappa = 16 + \min \{(P_b - 2), 15\}$  to decode symbol TERM.
+2. If TERM = 1, the decoder sets  $\tau_b = 0$
+
+3. Otherwise,  $TERM = 0$  and the MQ decoder is invoked with context label  $\kappa = 15$  (magnitude refinement context) to decode refinement bit  $r_b$ , after which the decoder the arc's state variables as follows:  $P_b := P_b + 1$ ;  $V_b := 2V_b + r_b$  and  $\tau_b := \tau_b - 1$ .
+
+## 9.5 TriBPT decoding procedures
+
+### 9.5.1 MQ Coder contexts and initial states for TriBPT decoding
+
+Up to 27 different MQ coder contexts are used for decoding TriBPT CL band code-blocks. Table 4 lists all context labels, along with the initial states for each context. Up to 4 contexts are used for non-root arc significance decoding, the last of these being a special "PARENT" context that is used only in the inter-band coding mode ( $BPT\_INTER = 1$ ). 5 contexts are used for root arc significance and induction block decoding. 16 contexts are used for the skip symbols used to identify the point at which magnitude refinement is skipped, if any, while just one context is used for magnitude refinement itself. Finally, a uniform context is provided for use with a run mode that plays the same role as the run mode used for significance decoding of non-breakpoint components in Rec. ITU-T T.800 | ISO/IEC 15444-1.
+
+For LL band code-blocks, decoding procedures are much simpler, using only a subset of the context labels shown in Table 4 and with different interpretations, but the same initial state values. The LL band context labels and their usage are provided in Table 5.
+
+**Table 4 – MQ coder contexts for TriBPT CL code-block decoding passes. State index values correspond to the Qe values and probability estimation transitions tabulated in Rec. ITU-T T.800 | ISO/IEC 15444-1**
+
+| Usage in CL band code-blocks   | Context label(s) | Initial state index        |                   |
+|--------------------------------|------------------|----------------------------|-------------------|
+|                                |                  | MQ probability state index | Initial MPS value |
+| Non-root significance INSIG    | 0                | 38                         | 0                 |
+| Non-root significance ANY-CUP  | 1                | 5                          | 0                 |
+| Non-root significance RUN      | 2                | 43                         | 0                 |
+| Non-root significance PARENT   | 3                | 38                         | 0                 |
+| Root significance INSIG        | 4                | 38                         | 0                 |
+| Root significance ANY-VTX      | 5                | 3                          | 0                 |
+| Root significance RUN          | 6                | 40                         | 0                 |
+| Root induction block           | 7                | 43                         | 0                 |
+| Root induction block           | 8                | 4                          | 0                 |
+| Magnitude bit                  | 9                | 0                          | 0                 |
+| Magnitude refinement TERMINATE | 10-25            | 40                         | 0                 |
+| UNIFORM                        | 26               | 46                         | 0                 |
+
+**Table 5 – Context labels from Table 4 that are used for TriBPT LL code-block decoding passes**
+
+| Usage in LL band code-blocks   | Context label(s) | Initial state (unchanged from Table 4) |                   |
+|--------------------------------|------------------|----------------------------------------|-------------------|
+|                                |                  | MQ probability state index             | Initial MPS value |
+| Significance flag decoding     | 1                | 5                                      | 0                 |
+| Vertex flag decoding           | 5                | 3                                      | 0                 |
+| Direct flag decoding           | 8                | 4                                      | 0                 |
+| Degenerate flag decoding       | 6                | 40                                     | 0                 |
+| Magnitude bit                  | 9                | 0                                      | 0                 |
+| Magnitude refinement TERMINATE | 10-25            | 40                                     | 0                 |
+| UNIFORM                        | 26               | 46                                     | 0                 |
+
+### 9.5.2 Derivation of context labels for TriBPT CL band significance coding passes
+
+Context labels employed when processing a (current) 4-span group during any of the CL band significance decoding passes are derived using context neighbourhoods that are depicted in Figure 29 and Figure 30, for the TriLR and TriRL orientations, respectively. In these figures, neighbouring arcs are labelled according to the relative location of their 4-span group, using a notation derived from directions on the compass: arcs coming from the 4-span group above the one being processed are labelled with the suffix "n" for "north"; arcs coming from the 4-span group to the right are labelled with the suffix "e" for "east"; arcs coming from the 4-span group above and to the right of the one being processed are labelled with the suffix "ne" for "north-east"; and so forth. If any of the neighbouring cells (shaded grey in Figure 29 and Figure 30) lie outside the boundaries of the code-block, their arcs shall be treated as insignificant for the purpose of generating context labels.
+
+![Figure 29: Neighbouring cells and arcs involved in forming coding contexts for TriLR significance decoding in CL band code-blocks. The diagram shows a central 2x2 grid of cells (HN1, HN2, VN1, VN2) with surrounding cells (DN1, DN2, HN1w, HN2w, HN1s, HN2s, VN1e, VN2e, DN1w, DN2w). Red arrows indicate the arcs between these cells, labeled with their respective context labels (e.g., VN1, DN1, HN1, HN2, DN1w, DN2w, HN1s, HN2s, VN1e, VN2e, DN1n, DN2n, VR1, DR1, VR2, DR2).](8d66c9c295023a1380f9986d3663bb1e_img.jpg)
+
+Figure 29: Neighbouring cells and arcs involved in forming coding contexts for TriLR significance decoding in CL band code-blocks. The diagram shows a central 2x2 grid of cells (HN1, HN2, VN1, VN2) with surrounding cells (DN1, DN2, HN1w, HN2w, HN1s, HN2s, VN1e, VN2e, DN1w, DN2w). Red arrows indicate the arcs between these cells, labeled with their respective context labels (e.g., VN1, DN1, HN1, HN2, DN1w, DN2w, HN1s, HN2s, VN1e, VN2e, DN1n, DN2n, VR1, DR1, VR2, DR2).
+
+T.816(23)
+
+**Figure 29 – Neighbouring cells and arcs involved in forming coding contexts for TriLR significance decoding in CL band code-blocks**
+
+For non-root significance decoding, arcs are grouped into pairs (VN1,VN2), (HN1,HN2) and (DN1,DN2). The context label used for the arcs in each pair are formed using two binary "cupping" values. The cupping values  $CUP_{Va}$  and  $CUP_{Vb}$  identify the significance of any of the neighbouring non-root arcs that surround the (VN1,VN2) pair on the left and right, respectively. Specifically, writing
+
+$$\bar{\sigma}_b(p) = \sigma_b \mid \sigma'_b(p)$$
+
+for the inclusive OR of an arc  $b$ 's significance  $\sigma_b$  and its inter-band significance  $\sigma'_b(p)$  for the current bit-plane  $p$ , the vertical non-root arc cupping values are given by
+
+$$CUP_{Va} = \begin{cases} \bar{\sigma}_{HN1w}(p) \mid \bar{\sigma}_{HN2w}(p) \mid \bar{\sigma}_{DN1w}(p) \mid \bar{\sigma}_{DN2w}(p) & \text{for TriLR} \\ \bar{\sigma}_{HN1sw}(p) \mid \bar{\sigma}_{HN2sw}(p) \mid \bar{\sigma}_{DN1w}(p) \mid \bar{\sigma}_{DN2w}(p) & \text{for TriRL} \end{cases}$$
+
+$$CUP_{Vb} = \begin{cases} \bar{\sigma}_{HN1s}(p) \mid \bar{\sigma}_{HN2s}(p) \mid \bar{\sigma}_{DN1}(p) \mid \bar{\sigma}_{DN2}(p) & \text{for TriLR} \\ \bar{\sigma}_{HN1}(p) \mid \bar{\sigma}_{HN2}(p) \mid \bar{\sigma}_{DN1}(p) \mid \bar{\sigma}_{DN2}(p) & \text{for TriRL} \end{cases}$$
+
+The horizontal non-root arc pair cupping values, denoted  $CUP_{Ha}$  and  $CUP_{Hb}$ , are given by
+
+$$CUP_{Ha} = \begin{cases} \bar{\sigma}_{VN1n}(p) | \bar{\sigma}_{VN2n}(p) | \bar{\sigma}_{DN1n}(p) | \bar{\sigma}_{DN2n}(p) & \text{for TriLR} \\ \bar{\sigma}_{VN1ne}(p) | \bar{\sigma}_{VN2ne}(p) | \bar{\sigma}_{DN1n}(p) | \bar{\sigma}_{DN2n}(p) & \text{for TriRL} \end{cases}$$
+
+$$CUP_{Hb} = \begin{cases} \bar{\sigma}_{VN1e}(p) | \bar{\sigma}_{VN2e}(p) | \bar{\sigma}_{DN1}(p) | \bar{\sigma}_{DN2}(p) & \text{for TriLR} \\ \bar{\sigma}_{VN1}(p) | \bar{\sigma}_{VN2}(p) | \bar{\sigma}_{DN1}(p) | \bar{\sigma}_{DN2}(p) & \text{for TriRL} \end{cases}$$
+
+Finally, the diagonal non-root arc pair cupping values, denoted  $CUP_{Da}$  and  $CUP_{Db}$ , are given by
+
+$$CUP_{Da} = \begin{cases} \bar{\sigma}_{VN1}(p) | \bar{\sigma}_{VN2}(p) | \bar{\sigma}_{HN1s}(p) | \bar{\sigma}_{HN2s}(p) & \text{for TriLR} \\ \bar{\sigma}_{VN1}(p) | \bar{\sigma}_{VN2}(p) | \bar{\sigma}_{HN1}(p) | \bar{\sigma}_{HN2}(p) & \text{for TriRL} \end{cases}$$
+
+$$CUP_{Db} = \begin{cases} \bar{\sigma}_{VN1e}(p) | \bar{\sigma}_{VN2e}(p) | \bar{\sigma}_{HN1}(p) | \bar{\sigma}_{HN2}(p) & \text{for TriLR} \\ \bar{\sigma}_{VN1e}(p) | \bar{\sigma}_{VN2e}(p) | \bar{\sigma}_{HN1s}(p) | \bar{\sigma}_{HN2s}(p) & \text{for TriRL} \end{cases}$$
+
+![Diagram illustrating the neighbouring cells and arcs involved in forming coding contexts for TriRL significance decoding in CL band code-blocks. The diagram shows a grid of cells with various arcs labeled. A central 2x2 grid of cells is highlighted with a dashed border. The cells are labeled with various arcs: DN1n, DN2n, DN1w, DN2w, HN1, HN2, HN1s, HN2s, VN1, VN2, VN1e, VN2e, VR1, VR2, DR1, DR2, HN1sw, HN2sw, HN1s, HN2s. The arcs are labeled with their respective values: DN1n, DN2n, DN1w, DN2w, HN1, HN2, HN1s, HN2s, VN1, VN2, VN1e, VN2e, VR1, VR2, DR1, DR2, HN1sw, HN2sw, HN1s, HN2s.](fd76efce549d3713543bb5ed9b023c2e_img.jpg)
+
+Diagram illustrating the neighbouring cells and arcs involved in forming coding contexts for TriRL significance decoding in CL band code-blocks. The diagram shows a grid of cells with various arcs labeled. A central 2x2 grid of cells is highlighted with a dashed border. The cells are labeled with various arcs: DN1n, DN2n, DN1w, DN2w, HN1, HN2, HN1s, HN2s, VN1, VN2, VN1e, VN2e, VR1, VR2, DR1, DR2, HN1sw, HN2sw, HN1s, HN2s. The arcs are labeled with their respective values: DN1n, DN2n, DN1w, DN2w, HN1, HN2, HN1s, HN2s, VN1, VN2, VN1e, VN2e, VR1, VR2, DR1, DR2, HN1sw, HN2sw, HN1s, HN2s.
+
+T.816(23)
+
+**Figure 30 – Neighbouring cells and arcs involved in forming coding contexts for TriRL significance decoding in CL band code-blocks**
+
+The MQ context labels used for significance decoding of any of the non-root arcs in the 4-span group are given by
+
+$$\kappa_{VN1}^{tbpt} = KAPPA_{nrt}^{tbpt}(CUP_{Va}, CUP_{Vb}, \sigma'_{VN1}(p));$$
+
+$$\kappa_{VN2}^{tbpt} = KAPPA_{nrt}^{tbpt}(CUP_{Va}, CUP_{Vb}, \sigma'_{VN2}(p));$$
+
+$$\kappa_{HN1}^{tbpt} = KAPPA_{nrt}^{tbpt}(CUP_{Ha}, CUP_{Hb}, \sigma'_{HN1}(p));$$
+
+$$\kappa_{HN2}^{tbpt} = KAPPA_{nrt}^{tbpt}(CUP_{Ha}, CUP_{Hb}, \sigma'_{HN2}(p));$$
+
+$$\kappa_{DN1}^{tbpt} = KAPPA_{nrt}^{tbpt}(CUP_{Da}, CUP_{Db}, \sigma'_{DN1}(p)); \text{ and}$$
+
+$$\kappa_{DN2}^{tbpt} = KAPPA_{nrt}^{tbpt}(CUP_{Da}, CUP_{Db}, \sigma'_{DN2}(p))$$
+
+where function  $\text{KAPPA}_{\text{nrt}}^{\text{tbpt}}$  is defined as follows
+
+$$\text{KAPPA}_{\text{nrt}}^{\text{tbpt}}(C_0, C_1, \sigma') = \begin{cases} \max\{C_0, C_1\} & \text{if } \sigma' = 0 \\ 3 & \text{if } \sigma' = 1 \end{cases}$$
+
+Each of the context labels is evaluated immediately prior to decoding an MQ symbol to determine whether the non-root arc in question is transitioning from insignificant to significant.
+
+NOTE 1 – The  $\text{KAPPA}_{\text{nrt}}^{\text{tbpt}}$  function returns one of the context labels 0, 1 or else 3 (in inter-band coding mode). Context label 2 from Table 4 is used for RUN symbol decoding, which is explained in 9.5.3.
+
+The MQ context labels used in the root significance pass are based on two quantities for each "root arc complex." A root arc complex consists of 3 root arcs that are surrounded by 6 non-root arcs. It is convenient to label the root arc complexes at the top and bottom of a 4-span group as  $C_T = (V_T, H_T, D_T)$  and  $C_B = (V_B, H_B, D_B)$ , respectively, and to label the 6 non-root arcs surrounding each complex as  $(V_{1_T}, V_{2_T}, H_{1_T}, H_{2_T}, D_{1_T}, D_{2_T})$  and  $(V_{1_B}, V_{2_B}, H_{1_B}, H_{2_B}, D_{1_B}, D_{2_B})$ . These labels are associated with the arcs shown in Figure 29 and Figure 30, for the TriLR and TriRL configurations, as follows:
+
+$$(V_T, H_T, D_T) = \begin{cases} (VR1, HR2, DR1) & \text{for TriLR} \\ (VR1, HR1, DR1) & \text{for TriRL} \end{cases}$$
+
+$$(V_B, H_B, D_B) = \begin{cases} (VR2, HR1, DR2) & \text{for TriLR} \\ (VR2, HR2, DR2) & \text{for TriRL} \end{cases}$$
+
+$$(V_{1_T}, V_{2_T}, H_{1_T}, H_{2_T}, D_{1_T}, D_{2_T}) = \begin{cases} (VN1e, VN2e, HN1, HN2, DN1, DN2) & \text{for TriLR} \\ (VN1, VN2, HN1, HN2, DN1, DN2) & \text{for TriRL} \end{cases}$$
+
+$$(V_{1_B}, V_{2_B}, H_{1_B}, H_{2_B}, D_{1_B}, D_{2_B}) = \begin{cases} (VN1, VN2, HN1s, HN2s, DN1, DN2) & \text{for TriLR} \\ (VN1e, VN2e, HN1s, HN2s, DN1, DN2) & \text{for TriRL} \end{cases}$$
+
+The first quantity used to determine root significance context labels for each complex is the joint significance of the surrounding non-root arc pairs, given by
+
+$$\text{NBR}_T = (\bar{\sigma}_{V_{1_T}}(p) \mid \bar{\sigma}_{V_{2_T}}(p)) \mid (\bar{\sigma}_{H_{1_T}}(p) \mid \bar{\sigma}_{H_{2_T}}(p)) \mid (\bar{\sigma}_{D_{1_T}}(p) \mid \bar{\sigma}_{D_{2_T}}(p)) \in \{0,1\}$$
+
+$$\text{NBR}_B = (\bar{\sigma}_{V_{1_B}}(p) \mid \bar{\sigma}_{V_{2_B}}(p)) \mid (\bar{\sigma}_{H_{1_B}}(p) \mid \bar{\sigma}_{H_{2_B}}(p)) \mid (\bar{\sigma}_{D_{1_B}}(p) \mid \bar{\sigma}_{D_{2_B}}(p)) \in \{0,1\}$$
+
+The second quantity is a binary flag indicating whether or not any other root arcs in the complex has been found to be significant as a vertex – i.e., not an induction block. These flags, denoted  $\text{VTX}_T$  and  $\text{VTX}_B$  are updated after each root arc is processed in the root significance decoding pass. Specifically,  $\text{VTX}_T$  and  $\text{VTX}_B$  can be understood as binary state variables that are initialized to 0 at the start of the block decoding procedure and set to 1 after any root arc in the corresponding root arc complex is decoded as a vertex.
+
+The MQ context labels used in the root significance coding pass are given by
+
+$$\kappa_{C_T}^{\text{tbpt}} = \text{KAPPA}_{\text{root}}^{\text{tbpt}}(\text{NBR}_T, \text{VTX}_T)$$
+
+and
+
+$$\kappa_{C_B}^{\text{tbpt}} = \text{KAPPA}_{\text{root}}^{\text{tbpt}}(\text{NBR}_B, \text{VTX}_B)$$
+
+where function  $\text{KAPPA}_{\text{root}}^{\text{tbpt}}$  is defined as follows:
+
+$$\text{KAPPA}_{\text{root}}^{\text{tbpt}}(N, V) = 4 + \max\{N, V\}$$
+
+The quantities  $\text{NBR}_T$ ,  $\text{NBR}_B$ ,  $\text{VTX}_T$  and  $\text{VTX}_B$  are also used to derive context labels  $\kappa_{\text{ibT}}^{\text{tbpt}}$  and  $\kappa_{\text{ibB}}^{\text{tbpt}}$  that are used to decode induction block symbols for each newly significant root arc in complex  $C_T$  or  $C_B$ , as appropriate. These labels are found from
+
+$$\kappa_{\text{ibT}}^{\text{qbpt}} = \begin{cases} 7 & \text{if } \text{NBR}_T < 2 \text{ or } \text{VTX}_T \neq 0 \\ 8 & \text{if } \text{NBR}_T \geq 2 \text{ and } \text{VTX}_T = 0 \end{cases}$$
+
+and
+
+$$\kappa_{\text{ibB}}^{\text{qbpt}} = \begin{cases} 7 & \text{if } \text{NBR}_B < 2 \text{ or } \text{VTX}_B \neq 0 \\ 8 & \text{if } \text{NBR}_B \geq 2 \text{ and } \text{VTX}_B = 0 \end{cases}$$
+
+NOTE 2 – The root significance decoding contexts described above involve context labels 4, 5, 7 and 8 only. Context label 6 from Table 4 is used for RUN symbol decoding, which is explained in 9.5.4.
+
+### 9.5.3 Non-root significance decoding for TriBPT CL code-blocks
+
+The non-root significance decoding pass for bit-plane  $p$  within a TriBPT CL band code-block processes 4-span groups in raster order, as shown in Figure 26 and Figure 27. For each 4-span group, the decoder enters a special "RUN mode" if the 4-span group has an entirely insignificant context, meaning that all cupping values are 0 and all root arcs within the group are also insignificant. That is, a 4-span group has entirely insignificant context if  $CUP_{Va}=CUP_{Vb}=CUP_{Ha}=CUP_{Hb}=CUP_{Da}=CUP_{Db}=0$ ,  $\sigma_{VR1}=\sigma_{VR2}=0$ ,  $\sigma_{HR1}=\sigma_{HR2}=0$  and  $\sigma_{DR1}=\sigma_{DR2}=0$ . When this condition is satisfied, the MQ decoder is invoked with context label  $\kappa=2$  (non-root significance RUN context – see Table 4) to decode an end-of-run symbol.
+
+If the end-of-run symbol is 0, the entire group remains insignificant and decoding proceeds to the next 4-span group, if any. If the end-of-run symbol is 1, then at least one of the 6 non-root arcs in the 4-span group is significant. The MQ decoder is then used with context label 26 (UNIFORM context – see Table 4) to decode either 2 or 3 symbols, so as to determine values SKIP\_TO\_NV, SKIP\_TO\_NH and SKIP\_TO\_ND in accordance with the following steps:
+
+1. SKIP\_TO\_NV, SKIP\_TO\_NH and SKIP\_TO\_ND are first initialized to 0.
+2. The MQ decoder is invoked with context label  $\kappa=26$  to obtain symbol Ra.
+3. If Ra = 1, the MQ decoder is invoked with  $\kappa=26$  to obtain symbol Rc, setting SKIP\_TO\_NV=2-Rc
+4. Otherwise, Ra = 0, and the following steps are performed:
+  - a. SKIP\_TO\_NV is set to 2
+  - b. The MQ decoder is invoked twice with  $\kappa=26$  to obtain symbol Rb and then symbol Rc:
+  - c. If Rb = 1, the decoder sets SKIP\_TO\_NH=2-Rc
+  - d. Otherwise, Rb = 0 and the decoder sets SKIP\_TO\_NH=2 and SKIP\_TO\_ND=2-Rc
+
+If the 4-span group does not have an entirely insignificant context, SKIP\_TO\_NV, SKIP\_TO\_NH and SKIP\_TO\_ND are all set to 0. In this case, and in the case where an end-of-run symbol of 1 was decoded, the decoder performs decoding steps first for the vertical non-root arcs VN1 and VN2, then for the horizontal non-root arcs HN1 and HN2, and finally for the diagonal non-root arcs DN1 and DN2, of the 4-span group, as follows.
+
+If  $SKIP\_TO\_NV < 2$  and  $\sigma_{VN1} = 0$ , the decoder performs the following decoding steps for arc VN1:
+
+- V1. If  $SKIP\_TO\_NV = 0$ , the MQ decoder is invoked with context label  $\kappa_{VN1}^{tbpt}$  to decode the SIG symbol; otherwise,  $SKIP\_TO\_NV = 1$  and the decoder sets SIG to 1.
+- V2. If SIG = 1, significance state  $\sigma_{VN1}$  is set to 1 and the following steps are performed:
+  - a. The cupping values of all cells that depend on  $\sigma_{VN1}$  are updated.
+  - b. The MQ decoder is invoked with context label  $\kappa=9$  (magnitude bit context – see Table 4) to decode the most significant value bit  $m_b$  of the arc  $b=VN1$ , and the type, precision and value for the arc are set to  $t_b=3$ ,  $P_b=2$  and  $V_b=m_b$ .
+
+Next, if  $SKIP\_TO\_NH = 0$  and  $\sigma_{VN2} = 0$ , the decoder performs the following steps for arc VN2:
+
+- V3. If  $SKIP\_TO\_NV < 2$ , the MQ decoder is invoked with context label  $\kappa_{VN2}^{tbpt}$  to decode the SIG symbol; otherwise, the  $SKIP\_TO\_NV = 2$  and the decoder sets SIG to 1.
+- V4. If SIG = 1, significance state  $\sigma_{VN2}$  is set to 1 and the following steps are performed:
+  - a. The cupping values of all cells that depend on  $\sigma_{VN2}$  are updated.
+  - b. The MQ decoder is invoked with context label  $\kappa=9$  (magnitude bit context – see Table 4) to decode the most significant value bit  $m_b$  of the arc  $b=VN2$ , and the type, precision and value for the arc are set to  $t_b=3$ ,  $P_b=2$  and  $V_b=m_b$ .
+
+Next,  $LIFE_V$  is decremented, unless it is already 0, and then if  $SKIP\_TO\_NH < 2$  and  $\sigma_{HN1} = 0$ , the decoder performs the following steps for arc HN1:
+
+- H1. If  $SKIP\_TO\_NH = 0$ , the MQ decoder is invoked with context label  $\kappa_{HN1}^{tbpt}$  to decode the SIG symbol; otherwise,  $SKIP\_TO\_NH = 1$  and the decoder sets SIG to 1.
+- H2. If SIG = 1, significance state  $\sigma_{HN1}$  is set to 1 and the following steps are performed:
+  - a. The cupping values of all cells that depend on  $\sigma_{HN1}$  are updated.
+  - b. The MQ decoder is invoked with context label  $\kappa=9$  (magnitude bit context – see Table 4) to decode the most significant value bit  $m_b$  of the arc  $b=HN1$ , and the type, precision and value for the arc are set to  $t_b=3$ ,  $P_b=2$  and  $V_b=m_b$ .
+
+Next, if  $SKIP\_TO\_ND = 0$  and  $\sigma_{HN2} = 0$ , the decoder performs the following steps for arc HN2:
+
+- H3. If  $SKIP\_TO\_NH < 2$ , the MQ decoder is invoked with context label  $\kappa_{HN2}^{tbpt}$  to decode the SIG symbol; otherwise, the  $SKIP\_TO\_NH = 2$  and the decoder sets SIG to 1.
+- H4. If SIG = 1, significance state  $\sigma_{HN2}$  is set to 1 and the following steps are performed:
+  - a. The cupping values of all cells that depend on  $\sigma_{HN2}$  are updated.
+
+- b. The MQ decoder is invoked with context label  $\kappa = 9$  (magnitude bit context – see Table 4) to decode the most significant value bit  $m_b$  of the arc  $b=HN2$ , and the type, precision and value for the arc are set to  $t_b = 3$ ,  $P_b = 2$  and  $V_b = m_b$ .
+
+Next,  $LIFE_H$  is decremented, unless it is already 0, and then if  $SKIP\_TO\_ND < 2$  and  $\sigma_{DN1} = 0$ , the decoder performs the following steps for arc DN1:
+
+- D1. If  $SKIP\_TO\_ND = 0$ , the MQ decoder is invoked with context label  $\kappa_{DN1}^{tbpt}$  to decode the SIG symbol; otherwise,  $SKIP\_TO\_ND = 1$  and the decoder sets SIG to 1.
+- D2. If  $SIG = 1$ , significance state  $\sigma_{DN1}$  is set to 1 and the following steps are performed:
+  - a. The cupping values of all cells that depend on  $\sigma_{DN1}$  are updated.
+  - b. The MQ decoder is invoked with context label  $\kappa = 9$  (magnitude bit context – see Table 4) to decode the most significant value bit  $m_b$  of the arc  $b=DN1$ , and the type, precision and value for the arc are set to  $t_b = 3$ ,  $P_b = 2$  and  $V_b = m_b$ .
+
+Next, if  $\sigma_{DN2} = 0$ , the decoder performs the following steps for arc DN2:
+
+- D3. If  $SKIP\_TO\_ND < 2$ , the MQ decoder is invoked with context label  $\kappa_{DN2}^{tbpt}$  to decode the SIG symbol; otherwise, the  $SKIP\_TO\_ND = 2$  and the decoder sets SIG to 1.
+- D4. If  $SIG = 1$ , significance state  $\sigma_{DN2}$  is set to 1 and the following steps are performed:
+  - c. The cupping values of all cells that depend on  $\sigma_{DN2}$  are updated.
+  - d. The MQ decoder is invoked with context label  $\kappa = 9$  (magnitude bit context – see Table 4) to decode the most significant value bit  $m_b$  of the arc  $b=DN2$ , and the type, precision and value for the arc are set to  $t_b = 3$ ,  $P_b = 2$  and  $V_b = m_b$ .
+
+### 9.5.4 Root significance decoding for TriBPT CL code-blocks
+
+The root significance decoding pass for bit-plane  $p$  within a TriBPT CL band code-block processes 4-span groups in raster order, as shown in Figure 26 and Figure 27. For each 4-span group, the decoder enters a special "RUN mode" if the 4-span group has an entirely insignificant context, meaning that all cupping values are 0 and all root arcs within the group are also insignificant. This is exactly the same condition described for non-root significance decoding in 9.5.3. When this condition is satisfied, the MQ decoder is invoked with context label  $\kappa = 6$  (root significance RUN context – see Table 4) to decode an end-of-run symbol.
+
+If the end-of-run symbol is 0, the entire group remains insignificant and decoding proceeds to the next 4-span group, if any. If the end-of-run symbol is 1, then at least one of the 6 root arcs in the 4-span group is significant. The MQ decoder is then used with context label 26 (UNIFORM context – see Table 4) to decode either 2 or 3 symbols, so as to determine values  $SKIP\_TO\_TOP$  and  $SKIP\_TO\_BOTTOM$  in accordance with the following steps:
+
+1. The MQ decoder is invoked with context label  $\kappa = 26$  to obtain symbol Ra
+2. The MQ decoder is then invoked with  $\kappa = 26$  to obtain symbol Rb
+3. If Rb = 0, the MQ decoder is invoked again with  $\kappa = 26$  to obtain symbol Rc; otherwise, Rc=0
+4. If Ra = 1,  $SKIP\_TO\_TOP$  is set to  $3 - 2 \cdot Rb - Rc$  and  $SKIP\_TO\_BOTTOM$  is set to 0
+5. Otherwise, Ra = 0 and  $SKIP\_TO\_TOP$  is set to 3 and  $SKIP\_TO\_BOTTOM$  is set to  $3 - 2 \cdot Rb - Rc$ .
+
+If the 4-span group does not have an entirely insignificant context,  $SKIP\_TO\_TOP$  and  $SKIP\_TO\_BOTTOM$  are both set to 0. In this case, and in the case where an end-of-run symbol of 1 was decoded, the decoder performs decoding steps first for the top root arc complex  $C_T$  and then for the bottom root arc complex  $C_B$  of the 4-span group. In the following description of this process, the root arcs of complex  $C_T$  are identified using the labels  $V_T$ ,  $H_T$  and  $D_T$ , as defined in 9.5.2, while the root arcs of complex  $C_B$  are identified using the labels  $V_B$ ,  $H_B$  and  $D_B$ . This relabelling of the arcs keeps the description of the decoding process independent of whether the breakpoint configuration is TriLR or TriRL.
+
+If  $SKIP\_TO\_TOP < 2$  and  $\sigma_{V_T} = 0$ , the decoder performs the following decoding steps for arc  $b = V_T$ :
+
+- V1. Context labels  $\kappa_{C_T}^{tbpt}$  and  $\kappa_{ibT}^{tbpt}$  are evaluated from  $NBR_T$  and  $VTX_T$ , as described in 9.5.2.
+- V2. If  $SKIP\_TO\_TOP = 0$ , the MQ decoder is invoked with context label  $\kappa_{C_T}^{tbpt}$  to decode the SIG symbol; otherwise,  $SKIP\_TO\_TOP = 1$  and the decoder sets SIG to 1.
+- V3. If  $SIG = 1$ , the MQ decoder is invoked with context label  $\kappa_{ibT}^{tbpt}$  to decode symbol IBLOCK.
+- V4. If  $SIG = 1$  and IBLOCK = 1, the decoder sets  $\sigma_b = 1$ ,  $t_b = 0$ ,  $P_b = 1$  (induction block) and  $\tau_b = 0$ .
+- V5. If  $SIG = 1$  and IBLOCK = 0,  $VTX_T$  is incremented and then the MQ decoder is invoked with context label 9 (magnitude bit context – see Table 4) to decode symbol  $m_b$ , setting  $\sigma_b = 1$ ,  $t_b = 3$ ,  $P_b = 2$  and  $V_b = m_b$ .
+
+If  $SKIP\_TO\_TOP < 3$  and  $\sigma_{H_T} = 0$ , the decoder performs the following decoding steps for arc  $b = H_T$ :
+
+- H1. Context labels  $\kappa_{C_T}^{tbpt}$  and  $\kappa_{ibT}^{tbpt}$  are evaluated from  $NBR_T$  and  $VTX_T$ , as described in 9.5.2.
+
+- H2. If  $\text{SKIP\_TO\_TOP} < 2$ , the MQ decoder is invoked with context label  $\kappa_{c_T}^{\text{tbpt}}$  to decode the SIG symbol; otherwise,  $\text{SKIP\_TO\_TOP} = 2$  and the decoder sets SIG to 1.
+- H3. If  $\text{SIG} = 1$ , the MQ decoder is invoked with context label  $\kappa_{ib_T}^{\text{tbpt}}$  to decode symbol IBLOCK.
+- H4. If  $\text{SIG} = 1$  and  $\text{IBLOCK} = 1$ , the decoder sets  $\sigma_b = 1$ ,  $t_b = 0$ ,  $P_b = 1$  (induction block) and  $\tau_b = 0$ .
+- H5. If  $\text{SIG} = 1$  and  $\text{IBLOCK} = 0$ ,  $\text{VTX}_T$  is incremented and then the MQ decoder is invoked with context label 9 (magnitude bit context – see Table 4) to decode symbol  $m_b$ , setting  $\sigma_b = 1$ ,  $t_b = 3$ ,  $P_b = 2$  and  $V_b = m_b$ .
+
+If  $\text{SKIP\_TO\_BOTTOM} = 0$  and  $\sigma_{D_T} = 0$ , the decoder performs the following decoding steps for arc  $b = D_T$ :
+
+- D1. Context labels  $\kappa_{c_T}^{\text{tbpt}}$  and  $\kappa_{ib_T}^{\text{tbpt}}$  are evaluated from  $\text{NBR}_T$  and  $\text{VTX}_T$ , as described in 9.5.2.
+- D2. If  $\text{SKIP\_TO\_TOP} < 3$ , the MQ decoder is invoked with context label  $\kappa_{c_T}^{\text{tbpt}}$  to decode the SIG symbol; otherwise,  $\text{SKIP\_TO\_TOP} = 3$  and the decoder sets SIG to 1.
+- D3. If  $\text{SIG} = 1$ , the MQ decoder is invoked with context label  $\kappa_{ib_T}^{\text{tbpt}}$  to decode symbol IBLOCK.
+- D4. If  $\text{SIG} = 1$  and  $\text{IBLOCK} = 1$ , the decoder sets  $\sigma_b = 1$ ,  $t_b = 0$ ,  $P_b = 1$  (induction block) and  $\tau_b = 0$ .
+- D5. If  $\text{SIG} = 1$  and  $\text{IBLOCK} = 0$ ,  $\text{VTX}_T$  is incremented and then the MQ decoder is invoked with context label 9 (magnitude bit context – see Table 4) to decode symbol  $m_b$ , setting  $\sigma_b = 1$ ,  $t_b = 3$ ,  $P_b = 2$  and  $V_b = m_b$ .
+
+If  $\text{SKIP\_TO\_BOTTOM} < 2$  and  $\sigma_{V_B} = 0$ , the decoder performs the following decoding steps for arc  $b = V_B$ :
+
+- V6. Context labels  $\kappa_{c_B}^{\text{tbpt}}$  and  $\kappa_{ib_B}^{\text{tbpt}}$  are evaluated from  $\text{NBR}_B$  and  $\text{VTX}_B$ , as described in 9.5.2.
+- V7. If  $\text{SKIP\_TO\_BOTTOM} = 0$ , the MQ decoder is invoked with context label  $\kappa_{c_B}^{\text{tbpt}}$  to decode the SIG symbol; otherwise,  $\text{SKIP\_TO\_BOTTOM} = 1$  and the decoder sets SIG to 1.
+- V8. If  $\text{SIG} = 1$ , the MQ decoder is invoked with context label  $\kappa_{ib_B}^{\text{tbpt}}$  to decode symbol IBLOCK.
+- V9. If  $\text{SIG} = 1$  and  $\text{IBLOCK} = 1$ , the decoder sets  $\sigma_b = 1$ ,  $t_b = 0$ ,  $P_b = 1$  (induction block) and  $\tau_b = 0$ .
+- V10. If  $\text{SIG} = 1$  and  $\text{IBLOCK} = 0$ ,  $\text{VTX}_B$  is incremented and then the MQ decoder is invoked with context label 9 (magnitude bit context – see Table 4) to decode symbol  $m_b$ , setting  $\sigma_b = 1$ ,  $t_b = 3$ ,  $P_b = 2$  and  $V_b = m_b$ .
+
+If  $\text{SKIP\_TO\_BOTTOM} < 3$  and  $\sigma_{H_B} = 0$ , the decoder performs the following decoding steps for arc  $b = H_B$ :
+
+- H6. Context labels  $\kappa_{c_B}^{\text{tbpt}}$  and  $\kappa_{ib_B}^{\text{tbpt}}$  are evaluated from  $\text{NBR}_B$  and  $\text{VTX}_B$ , as described in 9.5.2.
+- H7. If  $\text{SKIP\_TO\_BOTTOM} < 2$ , the MQ decoder is invoked with context label  $\kappa_{c_B}^{\text{tbpt}}$  to decode the SIG symbol; otherwise,  $\text{SKIP\_TO\_BOTTOM} = 2$  and the decoder sets SIG to 1.
+- H8. If  $\text{SIG} = 1$ , the MQ decoder is invoked with context label  $\kappa_{ib_B}^{\text{tbpt}}$  to decode symbol IBLOCK.
+- H9. If  $\text{SIG} = 1$  and  $\text{IBLOCK} = 1$ , the decoder sets  $\sigma_b = 1$ ,  $t_b = 0$ ,  $P_b = 1$  (induction block) and  $\tau_b = 0$ .
+- H10. If  $\text{SIG} = 1$  and  $\text{IBLOCK} = 0$ ,  $\text{VTX}_B$  is incremented and then the MQ decoder is invoked with context label 9 (magnitude bit context – see Table 4) to decode symbol  $m_b$ , setting  $\sigma_b = 1$ ,  $t_b = 3$ ,  $P_b = 2$  and  $V_b = m_b$ .
+
+If  $\sigma_{D_B} = 0$ , the decoder performs the following decoding steps for arc  $b = D_B$ :
+
+- D6. Context labels  $\kappa_{c_B}^{\text{tbpt}}$  and  $\kappa_{ib_B}^{\text{tbpt}}$  are evaluated from  $\text{NBR}_B$  and  $\text{VTX}_B$ , as described in 9.5.2.
+- D7. If  $\text{SKIP\_TO\_BOTTOM} < 3$ , the MQ decoder is invoked with context label  $\kappa_{c_B}^{\text{tbpt}}$  to decode the SIG symbol; otherwise,  $\text{SKIP\_TO\_BOTTOM} = 3$  and the decoder sets SIG to 1.
+- D8. If  $\text{SIG} = 1$ , the MQ decoder is invoked with context label  $\kappa_{ib_B}^{\text{tbpt}}$  to decode symbol IBLOCK.
+- D9. If  $\text{SIG} = 1$  and  $\text{IBLOCK} = 1$ , the decoder sets  $\sigma_b = 1$ ,  $t_b = 0$ ,  $P_b = 1$  (induction block) and  $\tau_b = 0$ .
+- D10. If  $\text{SIG} = 1$  and  $\text{IBLOCK} = 0$ ,  $\text{VTX}_B$  is incremented and then the MQ decoder is invoked with context label 9 (magnitude bit context – see Table 4) to decode symbol  $m_b$ , setting  $\sigma_b = 1$ ,  $t_b = 3$ ,  $P_b = 2$  and  $V_b = m_b$ .
+
+### 9.5.5 Root significance decoding for TriBPT LL code-blocks
+
+The significance decoding pass for bit-plane  $p$  within a TriBPT LL band code-block processes 2x2 cells in raster order. In the canonical scan, rows of cells are visited from top to bottom, cells of each row are visited from left to right, and the three arcs  $b$  of each cell are visited in the order V (vertical), H (horizontal) then D (diagonal).
+
+For each arc  $b$ , following this scanning order, if  $\sigma_b = 0$ , the MQ decoder is invoked with context label  $\kappa=1$  (significance flag context – see Table 5) to decode symbol SIG. If  $\text{SIG} = 0$ , arc  $b$  remains insignificant. Otherwise, the following steps are performed:
+
+1. The significance state for arc  $b$  is changed to  $\sigma_b = 1$
+2. The MQ decoder is invoked with context label  $\kappa = 5$  (vertex flag context – see Table 5) to decode symbol VTX.
+3. If  $\text{VTX} = 1$ , the breakpoint type for arc  $b$  is set to  $t_b = 3$ . Otherwise, the MQ decoder is invoked with context label  $\kappa = 8$  (direct flag context – see Table 5) to decode symbol DIRECT, and the type for arc  $b$  is set to  $t_b = 1 + \text{DIRECT}$ .
+
+4. If  $VTX = 0$ , the MQ decoder is invoked with context label  $\kappa = 6$  (degenerate flag context – see Table 5) to decode symbol DEGEN; otherwise DEGEN is set to 0.
+5. If DEGEN = 1, the following steps are performed:
+  - a. The MQ decoder is invoked with context label  $\kappa = 26$  (uniform context – see Table 5) to decode symbol AMBIVALENT.
+  - b. The precision and value parameters for arc  $b$  are set to  $P_b = \text{AMBIVALENT}$  and  $V_b = 0$  and the refinement counter is set to  $\tau_b = 0$  (not refinable).
+6. Otherwise, DEGEN = 0 and the MQ decoder is invoked with context label  $\kappa = 9$  (magnitude bit context) to decode the most significant value bit  $m_b$  of arc  $b$ . Then, the precision and value for the arc are set to  $t_b = 3$ ,  $P_b = 2$  and  $V_b = m_b$ .
+7. If  $VTX = 0$  and DEGEN = 0, the MQ decoder is invoked twice with context label  $\kappa = 26$  (uniform context – see Table 5) to decode symbol  $E_A$  and then  $E_B$ , and the extrapolation qualifier for arc  $b$  is set to  $e_b = 2 \cdot E_A + E_B$ .
+
+NOTE 1 – Coding procedures for LL band code-blocks are intended to be very simple, since in most cases all LL code-blocks are expected to be entirely insignificant. Coding tools are provided for the LL band of a breakpoint component primarily to allow the communication of breaks when  $N_L$  is heavily constrained, or even 0. For example, the breakpoints described by the breakpoint media format suggested in Annex B can be encapsulated directly within the LL band of a breakpoint component with  $N_L = 0$  decomposition levels.
+
+NOTE 2 – No means is provided to identify whether or not an arc without a break might hold an induction block, whereas this information can be recorded (as a hint) within the breakpoint media format suggested in Annex B. Induction blocks play no role in breakpoint dependent transforms and so there is no need to record them within resolution  $r = 0$  of a breakpoint component.
+
+### 9.5.6 Position refinement decoding for TriBPT code-blocks
+
+Position refinement decoding is the same for CL and LL band code-blocks of a TriBPT component, using MQ coder context labels 9 through 25 from Table 4 and Table 5, and processing  $2 \times 2$  cells in raster order. In the canonical scan, rows of cells are visited from top to bottom, cells of each row are visited from left to right, and the three arcs  $b$  of each cell are visited in the order V (vertical), H (horizontal) then D (diagonal).
+
+For each arc  $b$ , following this scanning order, if  $\sigma_b = 1$  and  $\tau_b > 0$ , the following steps are performed:
+
+1. The MQ decoder is invoked with context label  $\kappa = 10 + \min \{(P_b - 2), 15\}$  to decode symbol TERM.
+2. If TERM = 1, the decoder sets  $\tau_b = 0$
+3. Otherwise, TERM = 0 and the MQ decoder is invoked with context label  $\kappa = 9$  (magnitude refinement context) to decode refinement bit  $r_b$ , after which the decoder the arc's state variables as follows:  $P_b := P_b + 1$ ;  $V_b := 2V_b + r_b$  and  $\tau_b := \tau_b - 1$ .
+
+## 9.6 Quality layers and packets for breakpoint components
+
+As with other JPEG 2000 components, the coded information for a breakpoint tile-component is distributed across one or more layers in the codestream, each layer consisting of zero or more consecutive coding passes from each code-block in the tile. The number of coding passes in the layer can vary from code-block to code-block and the number of layers for the tile-component is signalled in the COD marker segment, exactly as for other JPEG 2000 components. Each layer corresponds to one packet of each precinct in each resolution of the tile-component.
+
+The packets of a breakpoint component have the same structure as packets of other components, as described in Rec. ITU-T T.800 | ISO/IEC 15444-1, with the same packet header syntax, except that additional signalling is introduced to identify the point at which a code-block's representation can be considered *complete*. Completeness is an important concept for breakpoint code-blocks. As mentioned in 9.1, the maximum bit-plane index for a code-block is
+
+$$p_{\max} = M_b - 1 - P,$$
+
+where  $P$  is the number of missing most significant bit-planes that is signalled via the packet header of the first packet to which the code-block contributes, and the maximum number of coding passes for the code-block is then
+
+$$Z_{\max} = 3p_{\max} + 2.$$
+
+However, not all of these coding passes need appear within packet headers. Certainly, the code-block's representation is complete if all of its  $Z_{\max}$  coding passes are found within codestream packets. A transcoder or other intermediate agent may truncate the representation, discarding packets so that fewer than  $Z_{\max}$  coding passes are available for decoding. In this case, the representation is incomplete and in the inter-band coding mode (BPT\_INTER = 1) this lack of completeness can prevent a decoder from processing some coding passes of other code-blocks that depend upon the information that has been removed. Alternatively, though, an encoder can choose to produce only a subset of the possible  $Z_{\max}$  coding passes, or indeed it can choose to produce no data at all for some code-block. This is fundamentally different from the removal of content by transcoding, because a decoder can still recover all originally encoded content, allowing it to be sure that all information required for decoding other code-blocks in the inter-band coding mode is actually available. To address the difference between these two ways in which the number of coding passes available for a code-block can be
+
+less than  $Z_{max}$ , the packet header syntax for breakpoint components is augmented to support the explicit signalling of code-block completeness.
+
+Two specific types of completeness are identified as *zero-completeness* and *pass-completeness*. A code-block is said to be *zero-complete* if it has no coding passes at all, but is nonetheless complete. This is a very common and important condition. A code-block for which no coding passes have yet been communicated via packet headers might have important information in later (possibly discarded) packets that is required to support the decoding of other code-blocks in the inter-band coding mode. However, a code-block which is zero-complete will never contribute any information and any other code-block that depends on the zero-complete code-block can assume that  $\sigma_{b'}(p) = 0$  for all bit-planes  $p$  and all arcs  $b'$  belonging to the zero-complete code-block.
+
+Zero-completeness for all code-blocks of a breakpoint precinct is signalled within the precinct's very first packet header, using an augmented version of the "code-block inclusion" signalling procedure. If the first packet for the precinct is a zero length packet, as defined in Rec. ITU-T T.800 | ISO/IEC 15444-1 (i.e., if the first bit in the packet header is 0), then zero-completeness is not coded in any packet header for the precinct and no code-block of the precinct is zero-complete.
+
+In the very first packet of a breakpoint component's precinct, the code-block inclusion signalling procedure is augmented with information that signals *all-completeness* and *any-completeness* values for each node in the precinct's tag tree. During the original code-block inclusion parsing process for layer 0, the nodes of the tag tree are traversed in the manner described in Rec. ITU-T T.800 | ISO/IEC 15444-1 to determine answers to the question "do any code-blocks covered by this node contribute coding passes to layer 0?" For each node visited within the tag tree scan, the original code-block inclusion parsing process decodes one bit  $i$ , such that the answer to the question is "yes" if  $i = 1$  and "no" if  $i = 0$ .
+
+For breakpoint components, this process is augmented to simultaneously answer the following two questions: 1) "are all code-blocks covered by this node zero-complete?" and 2) "is any code-block covered by this node zero-complete?" These three questions are answered by first decoding a bit  $z$ . If the value of  $z = 1$  then the answers are "no", "yes" and "yes" – that is, all code-blocks covered by the node are zero-complete and hence no code-block covered by the node makes any contribution to layer 0. If the value of  $z = 0$ , the usual inclusion bit  $i$  is decoded to answer the first question ("do any code-blocks contribute?") and a second bit  $n$  is then decoded to answer the third question ("is any code-block zero-complete?"). If the node is a leaf node, meaning that it represents only one code-block, then the  $n$  bit is not decoded, because the answer to the second and third questions must be the same ( $n = z$ ). If a parent node has already answered the first question with "no", then the  $i$  bit is not decoded because the answer  $i = 0$  is known. If a parent node has already answered the second question with "yes", then no bits are decoded because the answers to all questions are known ( $i = 0$ ,  $z = 1$  and  $n = 1$ ). If a parent node has already answered the third question with "no", then no  $z$  or  $n$  bit is decoded since the answers to the second and third questions are known ( $z = n = 0$ ).
+
+A code-block is said to be *pass-complete* if at least one coding pass of the code-block appears within codestream packets and the last such coding pass has been signalled as completing the representation. A pass-complete code-block cannot be zero-complete, because it contributes at least one coding pass. Pass completeness is signalled via a single bit  $c$ , that is decoded immediately after the "code-block inclusion information" for a code-block that has one or more included passes. Equivalently, bit  $c$  is decoded immediately before the "zero bit-plane information" for the code-block, if present, or else immediately before the "number of coding passes information" for the code-block, as described in Rec. ITU-T T.800 | ISO/IEC 15444-1. If the value of bit  $c$  is 1, then the code-block is pass-complete.
+
+Code-blocks that have been identified as pass-complete or zero-complete do not contribute "code-block inclusion" information to subsequent packets of their precinct.
+
+There are only two types of codeword segments for breakpoint code-blocks. Multiple codeword segments arise when termination of the MQ arithmetic coder occurs between coding passes which are included in a packet. However, the selective arithmetic coding bypass mode has no meaning within breakpoint components, so that termination of the MQ coder occurs either at the end of every coding pass or only at the end of the code-block. Thus, the two types of codeword segments that can arise for a breakpoint component are: a) one segment per code-block; and b) one segment per coding pass.
+
+Apart from selective arithmetic coding bypass and vertically causal contexts, all other block coding modes signalled via the code-block style information within SPcod and SPcoc fields of COD and COC marker segments apply to breakpoint components. Specifically, context probabilities may be reset on coding pass boundaries, the arithmetic coder may be terminated on each coding pass, the use of predictable arithmetic codeword termination may be identified, and segmentation symbols may be used. These all have the same meaning that they have for other JPEG 2000 component types, as specified in Rec. ITU-T T.800 | ISO/IEC 15444-1.
+
+# 10 Reconstruction of breakpoint components
+
+## 10.1 Overview
+
+This clause describes the synthesis of breakpoint values for each arc of each resolution in a breakpoint tile-component, using vertex and induction-block values recovered by decoding all relevant breakpoint code-blocks. Similar to the inverse wavelet transform, synthesis of a breakpoint tile-component proceeds in stages, from low to high resolution. Each stage combines breakpoint values from an LL band with a CL band, to form an intermediate LL band at the next higher resolution. This is illustrated in Figure 31.
+
+![Figure 31: Breakpoint synthesis stages. The diagram shows a sequence of stages from Stage 1 to Stage N_L. Stage 1 takes inputs LL_{N_L} and CL1 to produce LL_{N_L-1}. Stage 2 takes inputs LL_{N_L-1} and CL2 to produce LL_{N_L-2}. This pattern continues until Stage N_L, which takes inputs LL_{N_L-1} and CL_{N_L} to produce the final output LL_0. The diagram is labeled T.816(23) at the bottom right.](0a06de972d61ab9bb901bd74dd4ff51f_img.jpg)
+
+Figure 31: Breakpoint synthesis stages. The diagram shows a sequence of stages from Stage 1 to Stage N\_L. Stage 1 takes inputs LL\_{N\_L} and CL1 to produce LL\_{N\_L-1}. Stage 2 takes inputs LL\_{N\_L-1} and CL2 to produce LL\_{N\_L-2}. This pattern continues until Stage N\_L, which takes inputs LL\_{N\_L-1} and CL\_{N\_L} to produce the final output LL\_0. The diagram is labeled T.816(23) at the bottom right.
+
+|              |                                            |
+|--------------|--------------------------------------------|
+| CL1          | CL band at resolution $r = 1$              |
+| CL2          | CL band at resolution $r = 2$              |
+| CL $N_L$     | CL band at resolution $r = N_L$            |
+| $LL_{N_L}$   | input LL band at resolution $r = 0$        |
+| $LL_{N_L-1}$ | intermediate LL band at resolution $r = 1$ |
+| $LL_{N_L-2}$ | intermediate LL band at resolution $r = 2$ |
+| $LL_0$       | output LL band                             |
+
+**Figure 31 – Breakpoint synthesis stages**
+
+There is one synthesis stage for each non-base resolution  $r = 1, 2, \dots, N_L$ . The input to stage  $r$  consists of breakpoint values from an "LL band" at resolution  $r - 1$  and a CL band at resolution  $r$ , where these values consist of the breakpoint type  $t$ , precision  $P$ , and tick-point  $k$ , as introduced in 7.5. Input values from the CL band can only have types  $t = 3$  (vertex) or  $t = 0$  (no signalled break, or induction block). Output values from synthesis stage  $r$  preserve decoded information from the CL band at resolution  $r$ , but add induced breaks, having types  $t = 2$  (direct induction) and  $t = 1$  (spatial induction).
+
+Synthesis stage  $r$  involves three steps. In the first step, each arc breakpoint from the CL band at resolution  $r$  is transferred to the synthesis stage's output, whose rectangular region of support corresponds exactly to that of resolution  $r$ , as given by Formula (3). This transfer step discards any CL band breakpoints that do not exist in the output, because the grid-point at the centre of the arc lies outside the region of support for resolution  $r$ . This can happen, because the CL band includes a whole number of  $2 \times 2$  cells, some of which might only partially intersect the resolution's region of support.
+
+In the second step, LL breakpoints at resolution  $r - 1$  are used to directly induce breaks at resolution  $r$ , merging these into the synthesis stage's output, wherever they do not conflict with breaks transferred in the first step. This step is discussed further in 10.2.
+
+In the third step, the resolution  $r$  arc breakpoints produced by the first two steps are used to spatially induce additional breaks at resolution  $r$ . This is the spatial induction step and is the one that is most involved. This step is the subject of 10.3 and 10.4.
+
+## 10.2 Direct induction step
+
+### 10.2.1 Introduction
+
+For each non-root arc within the support of resolution  $r$ , there is almost always a corresponding "parent" arc breakpoint that exists within the support of resolution  $r - 1$ . The parent arc breakpoint, if it exists, belongs to the  $LL_{N_L+r-1}$  band that enters synthesis stage  $r$ , and it has arc length  $2^{d+1}$  when expressed at the full resolution of the tile-component, where  $d = N_L + 2 - r$ .
+
+NOTE – As defined in 7.4, non-root arcs necessarily have a corresponding parent arc in the next lower resolution, such that the two arcs are parallel and share an end-point. However, that parent arc's breakpoint, corresponding to the grid-point at its centre, might lie outside the rectangular region associated with resolution  $r - 1$ , as given by Formula (3), even though the non-root arc's breakpoint lies within the rectangular region for resolution  $r$ .
+
+The non-root arc has arc length  $2^d$  when expressed at the full resolution of the tile-component. Both arcs are co-linear and share one end-point, when projected onto the full resolution of the tile-component. In particular, the non-root arc coincides either with the first or the second half of its parent arc. This relationship is illustrated in Figure 32 for the specific case of horizontal arcs, but the same principals apply to vertical and diagonal arcs.
+
+![Figure 32: Relationship between non-root and parent arcs during direct induction in synthesis stage r, shown for the case of horizontal arcs. The diagram shows a horizontal line with five blue circles representing grid points. The first circle is labeled 4n, the second 4n+2, and the third 4n+4. Above the line, a red dashed arc labeled 'NRA' (non-root arc) connects the first and third circles. This arc is divided into two segments: the first segment is labeled '1st' and the second '2nd'. A red arrow points from the first segment to the second. Below the line, a black double-headed arrow labeled 'PRA' (parent arc) spans from the first to the third circle. To the right of the third circle, a black arrow points left towards the third circle, labeled 'HGP' (horizontal grid-point ordinates at resolution r). The reference 'T.816(23)' is at the bottom right.](3c99312f83459559d9a301148555d7b9_img.jpg)
+
+Figure 32: Relationship between non-root and parent arcs during direct induction in synthesis stage r, shown for the case of horizontal arcs. The diagram shows a horizontal line with five blue circles representing grid points. The first circle is labeled 4n, the second 4n+2, and the third 4n+4. Above the line, a red dashed arc labeled 'NRA' (non-root arc) connects the first and third circles. This arc is divided into two segments: the first segment is labeled '1st' and the second '2nd'. A red arrow points from the first segment to the second. Below the line, a black double-headed arrow labeled 'PRA' (parent arc) spans from the first to the third circle. To the right of the third circle, a black arrow points left towards the third circle, labeled 'HGP' (horizontal grid-point ordinates at resolution r). The reference 'T.816(23)' is at the bottom right.
+
+|     |                                                   |
+|-----|---------------------------------------------------|
+| NRA | non-root arc at resolution $r$                    |
+| PRA | parent arc at resolution $r-1$                    |
+| HGP | horizontal grid-point ordinates at resolution $r$ |
+
+**Figure 32 – Relationship between non-root and parent arcs during direct induction in synthesis stage  $r$ , shown for the case of horizontal arcs**
+
+If the parent arc exists within resolution  $r-1$  and has a break that lies within the span of the non-root arc at resolution  $r$ , and the non-root arc has no break of its own in the CL band at resolution  $r$ , a directly induced break is added to the non-root arc. The directly induced break is assigned breakpoint type  $t_{\text{induced}} = 2$ , with tick-point  $k_{\text{induced}}$  and precision  $P_{\text{induced}}$  obtained from those of the parent arc according to Formula (9).
+
+If  $P_{\text{induced}} = 1$  then the directly induced break that is added to the non-root arc is identified as an ambivalent break.
+
+If the parent arc at resolution  $r-1$  contains a break with precision  $P_{\text{parent}} \leq 1$ , then each of the two non-root arcs at resolution  $r$  are assigned an indefinite break with  $t_{\text{induced}} = 2$  and precision  $P_{\text{induced}} = 0$ .
+
+### 10.2.2 Extrapolation Qualifier for TriBPT direct induction
+
+For the TriBPT arrangement, each directly induced breakpoint at a resolution  $r$  is associated with extrapolation qualifiers comprised of a pair of binary flags  $\text{GRAD1\_FLAG}_{\text{induced}}$  and  $\text{GRAD2\_FLAG}_{\text{induced}}$  which are utilized during the breakpoint-dependent transform stage. As explained in 7.5, the two bit extrapolation qualifier  $e_b$  is equated to these flags, such that  $e_{b,0} = \text{GRAD1\_FLAG}_{\text{induced}}$  and  $e_{b,1} = \text{GRAD2\_FLAG}_{\text{induced}}$ . The process of determining the binary flags for each directly induced break is defined below.
+
+Starting with a vertex at resolution  $r-1$ , flags  $\text{GRAD1\_FLAG}_{\text{parent}}$  and  $\text{GRAD2\_FLAG}_{\text{parent}}$  are initialized to 0 (FALSE). The flag values  $\text{GRAD1\_FLAG}_{\text{induced}}$  and  $\text{GRAD2\_FLAG}_{\text{induced}}$  associated with the corresponding directly induced break at the finer resolution level  $r$  is determined in accordance with the following procedure.
+
+For the parent arc, if the breakpoint is located in the second half of the arc at resolution  $r-1$  (i.e., right or bottom half of the parent arc) then
+
+$$\begin{aligned}\text{GRAD1\_FLAG}_{\text{induced}} &= 1 \text{ (TRUE)} \\ \text{GRAD2\_FLAG}_{\text{induced}} &= \text{GRAD2\_FLAG}_{\text{parent}}\end{aligned}$$
+
+Otherwise, if the breakpoint on the parent arc is located in the first half of the arc at resolution  $r-1$  (i.e., left or top half of the parent arc) then
+
+$$\begin{aligned}\text{GRAD1\_FLAG}_{\text{induced}} &= \text{GRAD1\_FLAG}_{\text{parent}} \\ \text{GRAD2\_FLAG}_{\text{induced}} &= 1 \text{ (TRUE)}.\end{aligned}$$
+
+As direct induction proceeds to subsequent finer resolutions, the flags are determined at each resolution following the same procedure as that described above with the current *induced* arc at resolution  $r$  becoming the *parent* arc of the subsequent *induced* arc at the finer level  $r+1$ .
+
+## 10.3 QuadBPT spatial induction
+
+### 10.3.1 Introduction
+
+Spatial induction applies only to root arcs. As shown in Figure 3, for the QuadBPT arrangement, each intersecting pair of horizontal and vertical root arcs lies within a 2-span, surrounded on all sides by non-root arcs. QuadBPT spatial induction is based on breaks found on these surrounding non-root arcs alone. Breaks on the surrounding non-root arcs can correspond to decoded vertices at resolution  $r$ , direct induction at resolution  $r$ , or spatial induction at resolution  $r - 1$ . It can happen that some (or even all) of these surrounding non-root arcs do not actually exist within the rectangular support of resolution  $r$ , as given by Formula (3); any such non-root arc that does not exist is taken to have no break (i.e.,  $t = 0$  and  $P = 0$ ) for the purpose of spatial induction.
+
+It is useful to label the non-root arcs L (left), R (right), T (top) and B (bottom), designating them as perimeter arcs. It is also helpful to label the vertical and horizontal root arcs V and H, respectively. All of these arcs have length  $2^d$  when assessed at the top resolution of the tile-component, and any break on arc  $b$  is located on one of the tick-points identified in Formula (6), characterized by a tick-point index  $k_b$  in the range  $0 \leq k_b < 2^{d+F_B}$ . The breakpoint parameters for all quantities involved in spatial induction are denoted  $(t_L, P_L, k_L)$ ,  $(t_R, P_R, k_R)$ ,  $(t_T, P_T, k_T)$ ,  $(t_B, P_B, k_B)$ ,  $(t_V, P_V, k_V)$  and  $(t_H, P_H, k_H)$ , where the arc-identifying subscripts here correspond to the perimeter labels introduced above.
+
+Spatial induction to the V and H root arcs shall take place only if the following two conditions are both satisfied:
+
+1. Exactly 2 of the four perimeter arcs have breaks – i.e., two of  $t_L$ ,  $t_R$ ,  $t_T$  and  $t_B$  are non-zero.
+2. Neither of the root arcs has its own vertex or induction block; equivalently,  $P_V = 0$  and  $P_H = 0$  prior to spatial induction.
+
+Subject to the above conditions, labelling the two perimeter arcs with breaks as B1 and B2, if either of these is indefinite (i.e., if  $P_{B1} \cdot P_{B2} = 0$ ), then both root arcs are assigned indefinite breaks – i.e.,  $t_H = t_V = 1$  and  $P_H = P_V = 0$ . If either of the breaks B1 or B2 is ambivalent, that is  $\min\{P_{B1}, P_{B2}\} = 1$ , then both root arcs are assigned ambivalent breaks – i.e.,  $t_H = t_V = 1$  and  $P_H = P_V = 1$ . Otherwise, spatial induction is performed by generating a line segment between the tick-point locations associated with the perimeter breaks, as given by  $k_{B1}$  and  $k_{B2}$ , and finding its intersection, if any, with each of the V and H root arcs, rounding the resulting location to the nearest tick point. Writing R for the generic label of a root arc V or H, if an intersection exists with root arc R, it is assigned break-type  $t_R = 1$ , break-precision  $P_R = \min\{P_{B1}, P_{B2}\}$  and tick-point index  $k_R = f_{\text{quad}}(B1, B2, R, k_{B1}, k_{B2})$ , where  $f_{\text{quad}}$  is the QuadBPT intersection evaluation function, that depends on the locations and geometry of the three arcs B1, B2 and R, along with the perimeter break tick-points  $k_{B1}$  and  $k_{B2}$ .
+
+The function  $f_{\text{quad}}$  rounds the intersection between the line segment induced by the two perimeter breaks and the root arc R to the nearest available tick-point  $k_R$ . If the line segment induced by the two perimeter breaks is equidistant from two tick points, the induced break location is obtained by rounding away from the centre of the root arc. This is consistent with the way in which decoded vertices are mapped to breakpoints, as given by Formula (8).
+
+It remains to resolve the rounding ambiguity that arises when the line segment between perimeter breaks passes exactly through the centres of the two root arcs. This is only possible when inducing breaks from two horizontal perimeter breaks or from two vertical perimeter breaks that are located on opposite sides of their arc centres. To ensure that the spatially induced breakpoints have absolute geometric meaning, that can be preserved under horizontal or vertical geometric flips, transposition and rotation by multiples of  $90^\circ$ , this ambiguity is resolved by rounding towards the nearest root arcs at the next lower resolution, regardless of whether or not they actually exist. Equivalently, this last case is resolved by rounding towards the centre of the 4-span to which the V and H root arcs belong. These rounding policies are illustrated in Figure 33.
+
+![Figure 33: Rounding policies used in QuadBPT spatial induction. The diagram shows a 4-span grid with four 2-spans. Red 'x' marks indicate break positions. Arrows show rounding policies: RTN (Round to nearest), RAC (Round away from centre), RTL (Round towards lower resolution root arcs), and RAR (Root arcs at resolution r-1). The grid is divided into four quadrants by a central vertical and horizontal line. The bottom-right quadrant is shaded grey and labeled 'RAR'. The label 'T.816(23)' is in the bottom right corner.](99ff399927193b5527d8283e2a74747b_img.jpg)
+
+Figure 33: Rounding policies used in QuadBPT spatial induction. The diagram shows a 4-span grid with four 2-spans. Red 'x' marks indicate break positions. Arrows show rounding policies: RTN (Round to nearest), RAC (Round away from centre), RTL (Round towards lower resolution root arcs), and RAR (Root arcs at resolution r-1). The grid is divided into four quadrants by a central vertical and horizontal line. The bottom-right quadrant is shaded grey and labeled 'RAR'. The label 'T.816(23)' is in the bottom right corner.
+
+|     |                                          |
+|-----|------------------------------------------|
+| RTN | Round to nearest                         |
+| RAC | Round away from centre                   |
+| RTL | Round towards lower resolution root arcs |
+| RAR | Root arcs at resolution $r-1$            |
+
+**Figure 33 – Rounding policies used in QuadBPT spatial induction, showing different induction examples in three of the four 2-spans within a 4-span**
+
+### 10.3.2 Image boundary handling for QuadBPT
+
+For the QuadBPT case, a set of implied breaks are assumed for arcs that intersect the right and bottom image boundaries. As described in 7.1, the rectangular region of image samples, is defined by  $(x_o, y_o)$  for the upper left hand corner and  $(x_l - 1, y_l - 1)$  for the lower right hand corner. Implied breaks are placed on arcs that intersect the right vertical boundary at  $x_l - 1$  or the bottom horizontal boundary at  $y_l - 1$ .
+
+Possible break positions for implied breaks are denoted by *VrtBndry\_breakposition* and *HrzBndry\_breakposition* corresponding to the right-vertical boundary and the bottom-horizontal boundary respectively, and are specified below.
+
+$$VrtBndry\_breakposition = (x_l - 1) + 2^{-(F_B+1)}$$
+
+$$HrzBndry\_breakposition = (y_l - 1) + 2^{-(F_B+1)}$$
+
+NOTE 1 – These implied breaks are never explicitly communicated but assumed to exist and utilized to adapt the transform for arcs that intersect the right and bottom image boundaries.
+
+NOTE 2 – The implied break positions *VrtBndry\_breakposition* and *HrzBndry\_breakposition* are located outside the image region at one tick point away from the image boundary intersect.
+
+As an initialization step, for all resolution levels  $r$ , an arc centred at location  $\mathbf{p}$  that crosses the right or bottom image boundary is set to type  $t_b(\mathbf{p}) = 0$ .
+
+The set of implied breaks include implied vertices on arcs at the coarsest resolution level  $r = N_L$ , located at positions *VrtBndry\_breakposition* or *HrzBndry\_breakposition*, depending on the image boundary that an arc intersects.
+
+At finer resolution levels  $r < N_L$ , breaks on non-root arcs are determined by direct induction.
+
+Root arcs are subject to the spatial induction procedure. For a vertical root arc that intersects the horizontal image boundary, if spatial induction results in a break that has a location that is different to *HrzBndry\_breakposition* then an implied vertex is placed on the horizontal root arc of the 2-span that intersect the image boundary. Similarly, for a horizontal root arc that intersects the vertical image boundary, if spatial induction results in a break that has a location that is different to *VrtBndry\_breakposition* then implied vertices are placed on root arcs of the 2-span that intersect the image boundaries.
+
+NOTE 3 – spatial induction, induces breaks onto root arcs. If an induced break does not correctly model the image boundary then spatial induction is abandoned and implied vertices are placed on root arcs that intersect the image boundary. The need for such implied vertices on root arcs is most obvious at 2-span arrangements that contain the bottom right corner of the image region.
+
+## 10.4 TriBPT spatial induction
+
+### 10.4.1 TriBPT induction modes and corner notation
+
+Spatial induction applies only to root arcs and Figure 3 shows the three root arcs for the TriBPT-LR and TriBPT-RL configurations within each triangle of a 4-span. At a given resolution  $r$ , non-root arcs are sub-arcs of arcs at resolution  $r - 1$  while root arcs are new arcs that emerge at the current resolution (i.e they have no parent arcs at resolution  $r - 1$ ). Spatial induction for TriBPT components can be categorized into 4-arc and 3-arc induction modes. The 4-arc mode involves two non-root source arcs, whose breaks induce new breaks on two root arcs. The 3-arc mode involves one non-root source arc, with one root source arc, whose breaks induce a break on one root arc. Both modes are specified below after introducing important notation. In all cases, source breaks on non-root arcs correspond to vertices decoded at resolution  $r$  or breaks that are directly induced from breaks at resolution  $r - 1$ , which can have been vertices, directly induced or spatially induced breaks. Where an induction source break belongs to a root arc (3-arc mode), it corresponds to a decoded vertex at resolution  $r$ .
+
+![Figure 34: Arc and corner labels for the TriBPT-LR arrangement. The diagram shows a triangular grid of arcs. Three root arcs are labeled V (vertical), H (horizontal), and D (diagonal). Non-root arcs forming the corners are labeled with 'cnr' suffixes: H_v_cnr, D_v_cnr, V_h_cnr, D_h_cnr, H_d_cnr, and V_d_cnr. Red arrows indicate induction paths from non-root arcs to root arcs. The diagram is labeled T.816(23) at the bottom.](50ef8602c7c9edd2da0e2133e772c2a2_img.jpg)
+
+Figure 34: Arc and corner labels for the TriBPT-LR arrangement. The diagram shows a triangular grid of arcs. Three root arcs are labeled V (vertical), H (horizontal), and D (diagonal). Non-root arcs forming the corners are labeled with 'cnr' suffixes: H\_v\_cnr, D\_v\_cnr, V\_h\_cnr, D\_h\_cnr, H\_d\_cnr, and V\_d\_cnr. Red arrows indicate induction paths from non-root arcs to root arcs. The diagram is labeled T.816(23) at the bottom.
+
+Figure 34 – Arc and corner labels for the TriBPT-LR arrangement
+
+As shown in Figure 34, root arcs are labelled V (vertical), H (horizontal) and D (diagonal). In the 4-span arrangement, the non-root horizontal and diagonal arcs that form the corner adjacent to V are labelled  $H_{v\_cnr}$  and  $D_{v\_cnr}$  respectively. The vertical and diagonal non-root arcs that form the corner adjacent to H are labelled  $V_{h\_cnr}$  and  $D_{h\_cnr}$ , respectively, while the horizontal and vertical arcs that form the corner adjacent to D are labelled  $H_{d\_cnr}$  and  $V_{d\_cnr}$ . All of these arcs have length  $2^d$  when assessed at the top resolution of the tile-component, and all break positions lie on tick-points in accordance with Formula (6), identified by tick-point indices  $k_b$  in the range  $0 \leq k_b < 2^{d+FB}$ . The breakpoint parameters for all quantities involved in spatial induction are denoted  $(t_b, P_b, k_b)$ , where the relevant arcs  $b$  have the labels  $b \in \{V, H_{v\_cnr}, D_{v\_cnr}, H_{h\_cnr}, V_{h\_cnr}, D_{h\_cnr}, D_{d\_cnr}, H_{d\_cnr}, V_{d\_cnr}\}$ .
+
+The term  $N_{V\_cnr}$  denotes a count of the number of breaks that are present in the vertical corner's non-root arcs  $H_{v\_cnr}$  and  $D_{v\_cnr}$ . Similarly,  $N_{H\_cnr}$  counts the number of breaks present on the horizontal corner's non-root arcs  $V_{h\_cnr}$  and  $D_{h\_cnr}$ , and  $N_{D\_cnr}$  counts the number of breaks present on the diagonal corner's non-root arcs  $H_{d\_cnr}$  and  $V_{d\_cnr}$ . These counts all lie in the range 0 to 2.
+
+The notation  $S_{X\_cnr}$  is used to label a corner  $X\_cnr$ , where  $X \in \{V, H, D\}$ , as being either a candidate source corner ( $S_{X\_cnr} = 1$ ) or a non-candidate ( $S_{X\_cnr} = 0$ ) corner for spatial induction. If  $N_{X\_cnr} = 1$  and the root arc  $X$  does not have a vertex or an induction block (i.e.,  $P_X = 0$ ) then  $S_{X\_cnr} = 1$ ; otherwise  $S_{X\_cnr} = 0$ . A label of  $S_{X\_cnr} = 1$  signifies that the corner  $X\_cnr$  contains a single non-root arc with a breakpoint that can potentially be a source for defining the line segment for spatial induction and that this induction is not impeded by a vertex or induction block in the corresponding root arc  $X$ .
+
+### 10.4.2 4-arc mode
+
+The 4-arc mode involves new breaks on two root arcs being induced by breaks specified on two non-root arcs that are located at different corners. This spatial induction to two out of the three root arcs (i.e., two of V, H and D) shall take place only if the following conditions are all satisfied:
+
+1. None of the three root arcs has its own vertex; equivalently,  $P_V = 0$ ,  $P_D = 0$ , and  $P_H = 0$  prior to spatial induction.
+2. Two out of the three corners are labelled as being a source corner for spatial induction; that is  $S_{H\_cnr} + S_{V\_cnr} + S_{D\_cnr} = 2$ .
+3. The non-root arcs with breaks that are associated with the two source corners have different orientations – i.e., the source breaks cannot both lie on vertical arcs, both lie on horizontal arcs or both lie on diagonal arcs.
+
+In accordance with the above conditions, let  $X\_cnr$  and  $Y\_cnr$  correspond to the two identified source corners, that is  $S_{X\_cnr} = S_{Y\_cnr} = 1$  where  $X, Y \in \{V, H, D\}$ , s. t.  $X \neq Y$ . The corresponding non-root arcs with breaks that originate from
+
+these two source corners are labelled  $B1_{x\_cnr}$  and  $B2_{y\_cnr}$ . In the following discussions, the subscript is omitted for ease of notation and these two non-root arcs are referred to as B1 and B2.
+
+Spatial induction is performed by generating a line segment between the tick-point locations associated with the non-root arc breaks, as given by  $k_{B1}$  and  $k_{B2}$ , and finding its intersection with two of the three root arcs and then rounding the resulting location to the nearest tick point. In keeping with the above notation, X and Y refer to the two root arcs on which breaks points are induced. The two induced breakpoint parameters can therefore be denoted as  $(t_X, P_X, k_X)$  and  $(t_Y, P_Y, k_Y)$ . If either of the breaks on non-root arcs B1 and B2 is indefinite (i.e., if  $P_{B1} \cdot P_{B2} = 0$ ), then the corresponding two root arcs are assigned indefinite breaks – i.e.,  $t_X = t_Y = 1$  and  $P_X = P_Y = 0$ . If however  $\min\{P_{B1}, P_{B2}\} = 1$ , then the corresponding two root arcs are assigned ambivalent breaks – i.e.,  $t_X = t_Y = 1$  and  $P_X = P_Y = 1$ . Otherwise, the induced breakpoint parameters are assigned as break-type  $t_X = t_Y = 1$ , break-precision  $P_X = P_Y = \min\{P_{B1}, P_{B2}\}$  and tick-point index  $k_X = f_{tri}(B1, B2, X, k_{B1}, k_{B2})$  and  $k_Y = f_{tri}(B1, B2, Y, k_{B1}, k_{B2})$  where  $f_{tri}$  is the TriBPT intersection evaluation function, that depends on the locations and geometry of the root arc on which a break is being induced, that is either X or Y, and the two non-root arcs B1, B2 along with the corresponding break tick-points  $k_{B1}$  and  $k_{B2}$ . The function  $f_{tri}$  rounds the intersection between the line segment induced by the two non-root arc breaks and the root arc X (Y) to the nearest available tick-point  $k_X(k_Y)$ .
+
+Examples of all 9 possible non-root arc pair combinations that can result in inducing breaks on two root arcs are shown in Figure 35 for the TriBPT-LR arrangement.
+
+![Figure 35: 4-arc mode spatial induction examples for the TriBPT-LR arrangement. The figure consists of a 3x3 grid of diagrams. Each diagram shows a square frame with a blue diagonal line from the top-left to the bottom-right. Inside the square, there are green lines forming a grid. Red 'X' marks indicate break points on the blue diagonal line. The diagrams are labeled as follows: Top row: H_v_cnr - V_h_cnr, H_v_cnr - V_d_cnr, H_v_cnr - D_h_cnr. Middle row: V_d_cnr - D_v_cnr, V_d_cnr - D_h_cnr, D_v_cnr - V_h_cnr. Bottom row: V_d_cnr - D_v_cnr, V_d_cnr - D_h_cnr, D_v_cnr - V_h_cnr. The labels are positioned below each diagram. The bottom right diagram is labeled T.816(23).](fcdcb5991d671cadf547dd3fbfe13486_img.jpg)
+
+Figure 35: 4-arc mode spatial induction examples for the TriBPT-LR arrangement. The figure consists of a 3x3 grid of diagrams. Each diagram shows a square frame with a blue diagonal line from the top-left to the bottom-right. Inside the square, there are green lines forming a grid. Red 'X' marks indicate break points on the blue diagonal line. The diagrams are labeled as follows: Top row: H\_v\_cnr - V\_h\_cnr, H\_v\_cnr - V\_d\_cnr, H\_v\_cnr - D\_h\_cnr. Middle row: V\_d\_cnr - D\_v\_cnr, V\_d\_cnr - D\_h\_cnr, D\_v\_cnr - V\_h\_cnr. Bottom row: V\_d\_cnr - D\_v\_cnr, V\_d\_cnr - D\_h\_cnr, D\_v\_cnr - V\_h\_cnr. The labels are positioned below each diagram. The bottom right diagram is labeled T.816(23).
+
+Figure 35 – 4-arc mode spatial induction examples for the TriBPT-LR arrangement
+
+### 10.4.3 3-arc mode
+
+The 3-arc mode involves one non-root source arc and one root source arc, whose breaks induce a break on one root arc. This spatial induction to one root arc shall take place only if the following conditions are all satisfied:
+
+1. One of the three root arcs has its own vertex while the remaining two root arcs have no vertex of their own.
+2. One out of the three corners are labelled as being a source corner for spatial induction; that is  $S_{H\_cnr} + S_{V\_cnr} + S_{D\_cnr} = 1$ .
+
+Let R represent the root arc that has its own vertex, with the break parameters given by  $(t_R, P_R, k_R)$  where  $t_R = 3$ . Furthermore let  $X\_cnr$  correspond to the single identified source corner, that is  $S_{X\_cnr} = 1$ , and let  $B1_{x\_cnr}$  correspond to
+
+the non-root arc within  $X_{\text{cnr}}$  that has a break. In the following discussions, for ease of notation the subscript is omitted and  $B1_{x_{\text{cnr}}}$  is referred to as  $B1$ .
+
+In keeping with the above notation, breaks on arcs  $R$  and  $B1$  induce a new break on the root arc  $X$ . This 3-arc mode spatial induction is performed by first generating a line segment between the tick-point locations associated with the vertex on the root arc given by  $k_R$  and the break on the non-root arc given by  $k_{B1}$ . The intersection of this line segment with the root arc  $X$  is then determined and the resulting location rounded to the nearest tick point. The parameters of the new induced breakpoint are denoted as  $(t_X, P_X, k_X)$ . If the break on the non-root arc  $B1$  is indefinite (i.e., if  $P_{B1} = 0$ ), then the corresponding root arc  $X$  is assigned an indefinite break – i.e.,  $t_X = 1$  and  $P_X = 0$ . If however the break on the non-root arc  $B1$  is ambivalent (i.e., if  $P_{B1} = 1$ ), then the corresponding root arc  $X$  is assigned an ambivalent break – i.e.,  $t_X = 1$  and  $P_X = 1$ . Otherwise, the induced breakpoint parameters are assigned with break-type  $t_X = 1$ , break-precision  $P_X = \min\{P_R, P_{B1}\}$  and tick-point index  $k_X = f_{\text{tri}}(R, B1, X, k_R, k_{B1})$  where  $f_{\text{tri}}$  is the TriBPT intersection evaluation function as described above.
+
+Examples of all 12 possible root and non-root arc pair combinations that can result in a 3-arc mode inducing of breaks are shown in Figure 36 for the TriBPT-LR arrangement.
+
+![Figure 36: 3-arc mode spatial induction examples for the TriBPT-LR arrangement. The figure consists of a 3x4 grid of diagrams. Each diagram shows a triangular grid with a blue root arc (X) and a green non-root arc (B1). Red 'X' marks indicate breaks. The diagrams are labeled as follows: Row 1: V - H_d_cnr, V - V_d_cnr, V - V_h_cnr, V - D_h_cnr; Row 2: D - D_v_cnr, D - H_v_cnr, D - V_h_cnr, D - D_h_cnr; Row 3: H - D_v_cnr, H - H_v_cnr, H - H_d_cnr, H - V_d_cnr. The labels indicate the root arc type (V for vertical, D for diagonal, H for horizontal) and the non-root arc type (H, V, D) with a subscript indicating the mode (e.g., d_cnr, v_cnr, h_cnr).](8e395c7d3a0249c410ef3c5a4f666170_img.jpg)
+
+Figure 36: 3-arc mode spatial induction examples for the TriBPT-LR arrangement. The figure consists of a 3x4 grid of diagrams. Each diagram shows a triangular grid with a blue root arc (X) and a green non-root arc (B1). Red 'X' marks indicate breaks. The diagrams are labeled as follows: Row 1: V - H\_d\_cnr, V - V\_d\_cnr, V - V\_h\_cnr, V - D\_h\_cnr; Row 2: D - D\_v\_cnr, D - H\_v\_cnr, D - V\_h\_cnr, D - D\_h\_cnr; Row 3: H - D\_v\_cnr, H - H\_v\_cnr, H - H\_d\_cnr, H - V\_d\_cnr. The labels indicate the root arc type (V for vertical, D for diagonal, H for horizontal) and the non-root arc type (H, V, D) with a subscript indicating the mode (e.g., d\_cnr, v\_cnr, h\_cnr).
+
+T.816(23)
+
+Figure 36 – 3-arc mode spatial induction examples for the TriBPT-LR arrangement
+
+### 10.4.4 Extrapolation qualifier for TriBPT spatial induction
+
+As explained in 7.5, each spatially induced breakpoint is associated with an extrapolation-qualifier  $e_b$  which is comprised of two binary flags  $e_{b,0}$  and  $e_{b,1}$ , such that  $e_b = (e_{b,1}, e_{b,0})$ . A break divides an arc into two parts and the binary value of  $e_{b,0}$  conveys information required for performing extrapolation for the first part while  $e_{b,1}$  corresponds to information for the second part of the arc. The values of these flags are determined when new breaks are spatially induced onto root arcs in accordance with either 4-arc or 3-arc mode. The process of determining the flags for spatially induced breaks on root arcs is defined below.
+
+For a parent-4-span arrangement, as shown in Figure 34, let  $R \in \{V, H, D\}$  represent a root arc with a spatially induced break at resolution  $r$ . The two endpoints of the root arc  $R$  are labelled *end-point1* and *end-point2*. The first endpoint, *end-point1*, is located on the left side of the arc for horizontal arcs or on top for vertical and diagonal arcs and the second endpoint, *end-point2*, is located on the right side for horizontal arcs or at the bottom for vertical and diagonal arcs. The
+
+locations of the two endpoints  $\mathbf{p}^{end-point1}$  and  $\mathbf{p}^{end-point2}$  are specified below where the centre of root arc  $R$  is denoted by  $\mathbf{p}^R = (n^R, m^R)$ .
+
+$$\mathbf{p}^{end-point1} = (n^{end-point1}, m^{end-point1}) = \begin{cases} (n^R - 1, m^R) & \text{if } R \text{ is Horizontal} \\ (n^R, m^R - 1) & \text{if } R \text{ is Vertical} \\ (n^R - s_{LR}, m^R - 1) & \text{if } R \text{ is Diagonal} \end{cases}$$
+
+$$\mathbf{p}^{end-point2} = (n^{end-point2}, m^{end-point2}) = \begin{cases} (n^R + 1, m^R) & \text{if } R \text{ is Horizontal} \\ (n^R, m^R + 1) & \text{if } R \text{ is Vertical} \\ (n^R + s_{LR}, m^R + 1) & \text{if } R \text{ is Diagonal} \end{cases}$$
+
+In the parent-4-span arrangement, there are two non-root arcs  $(N1^{end-point1}, N2^{end-point1}) \in \{(H_{v\_cnr}, H_{d\_cnr}), (V_{h\_cnr}, V_{d\_cnr}), (D_{v\_cnr}, D_{h\_cnr})\}$  of the same orientation that share end-point1. The grid-line at resolution  $r$  that contains both non-root arcs  $N1^{end-point1}$  and  $N2^{end-point1}$ , is referred to as *base-line1*. As explained in 8.2.5, a spatially induced break on a root arc is defined by two source breaks and the line formed by these two induction source breaks is referred to as the *break-inducing-line*. The intersection of the break-inducing-line and base-line1 is labelled *base-intersection-point1* with  $\mathbf{p}^{base-intersect1}$  denoting the corresponding coordinates. These terms are illustrated with an example in Figure 37. The non-root arc, either  $N1^{end-point1}$  or  $N2^{end-point1}$ , that is located further away from the base-intersection-point1 is identified as the *base-non-root-arc1* and is denoted as *bnr1* with  $\mathbf{p}^{bnr1}$  corresponding to the centre location of this arc. A binary flag  $DRCTN1\_FLAG_{induced}$  is used to represent the direction of  $\mathbf{p}^{bnr1} = (n^{bnr1}, m^{bnr1})$  with reference to  $\mathbf{p}^{end-point1} = (n^{end-point1}, m^{end-point1})$  as shown below.
+
+If *bnr1* is a horizontal arc, then
+
+$$DRCTN1\_FLAG_{induced} = \begin{cases} 1 & n^{bnr1} > n^{end-point1} \\ 0 & \text{Otherwise} \end{cases}$$
+
+Else if *bnr1* is a vertical or diagonal arc then
+
+$$DRCTN1\_FLAG_{induced} = \begin{cases} 1 & m^{bnr1} > m^{end-point1} \\ 0 & \text{Otherwise} \end{cases}$$
+
+![Figure 37: Example of intersection points, arcs and grid-lines required for determining the extrapolation qualifier for a spatially induced break. The diagram shows a grid of lines with a diagonal break-inducing line (BIL) and two base-lines (BLN1, BLN2). Key points include BIP1, BIP2, EP1, EP2, and various arcs (N1, N2) and breaks (BNR1, BNR2). A spatially induced break (SPB) is also indicated.](2cc973099f02f2cc67558feea3b18cde_img.jpg)
+
+T.816(23)
+
+Figure 37: Example of intersection points, arcs and grid-lines required for determining the extrapolation qualifier for a spatially induced break. The diagram shows a grid of lines with a diagonal break-inducing line (BIL) and two base-lines (BLN1, BLN2). Key points include BIP1, BIP2, EP1, EP2, and various arcs (N1, N2) and breaks (BNR1, BNR2). A spatially induced break (SPB) is also indicated.
+
+|      |                          |
+|------|--------------------------|
+| BIP1 | base-intersection-point1 |
+| BIP2 | base-intersection-point2 |
+| BLN1 | base-line1               |
+| BLN2 | base-line2               |
+| EP1  | end-point1               |
+| EP2  | end-point2               |
+| BIL  | break-inducing-line      |
+| SPB  | spatially induced break  |
+
+This figure illustrates an example of a diagonal root arc containing a spatially induced break, with  $DRCTN1\_FLAG_{induced} = 1$  and  $DRCTN2\_FLAG_{induced} = 1$ .
+
+**Figure 37 – Example of intersection points, arcs and grid-lines required for determining the extrapolation qualifier for a spatially induced break**
+
+A similar process is followed for end-point2. Non-root arcs of the parent-4-span arrangement that share end-point2, are denoted as  $(N1^{end-point2}, N2^{end-point2}) \in \{(H_{v.cnr}, H_{d.cnr}), (V_{h.cnr}, V_{d.cnr}), (D_{v.cnr}, D_{h.cnr})\}$ . The grid-line at resolution  $r$  that contains both non-root arcs  $N1^{end-point2}$  and  $N2^{end-point2}$ , is referred to as *base-line2* and the intersection of the break-inducing-line and base-line2 is referred to as the *base-intersection-point2*. The non-root arc, either  $N1^{end-point2}$  or  $N2^{end-point2}$ , that is located further away from the base-intersection-point2 is identified as the *base-non-root-arc2* and is denoted as  $bnr2$  with  $p^{bnr2}$  corresponding to the centre location of this arc. A binary flag  $DRCTN2\_FLAG_{induced}$  is used to represent the direction of  $p^{bnr2} = (n^{bnr2}, m^{bnr2})$  with reference to  $p^{end-point2} = (n^{end-point2}, m^{end-point2})$  as shown below.
+
+If  $bnr2$  is a horizontal arc, then
+
+$$DRCTN2\_FLAG_{induced} = \begin{cases} 1 & n^{bnr2} > n^{end-point2} \\ 0 & \text{Otherwise} \end{cases}$$
+
+Else if  $bnr2$  is a vertical or diagonal arc then
+
+$$DRCTN2\_FLAG_{induced} = \begin{cases} 1 & m^{bnr2} > m^{end-point2} \\ 0 & \text{Otherwise} \end{cases}$$
+
+The two binary flags are equated to the two bits of the extrapolation-qualifier as shown below.
+
+$$e_{b,0} = DRCTN1\_FLAG_{induced}$$
+
+$$e_{b,1} = \text{DRCTN2\_FLAG}_{\text{induced}}$$
+
+The extrapolation-qualifier value is passed on from root arc  $R$  to sub-arcs recursively at finer resolutions through direct induction.
+
+### 10.4.5 Rounding policies for TriBPT spatial induction
+
+As for QuadBPT spatial induction, where the line segment formed by source breakpoints is equidistant from two candidate tick points on a root arc, the induced break location is obtained by rounding away from the centre of the root arc. This rounding policy alone can be ambiguous in the 3-arc mode, when the arcs  $R$  and  $B1$  associated with the two source breaks both have the same orientation, since it is then possible for the line segment to intersect the root arc  $X$  at its centre. This ambiguity is resolved by rounding towards the intersection of root arcs  $R$  (i.e., the root arc which contains a source break) and  $X$  (i.e., the root arc containing the spatially induced break). Examples of this rounding policy is shown in Figure 38 where the direction of rounding along root arc  $X$  is shown by the black arrows.
+
+![Figure 38: Examples of rounding policy for 3-arc mode spatial induction. The figure consists of six sub-diagrams arranged in a 2x3 grid. Each sub-diagram shows a triangular grid of points with a central root arc X. Two source arcs, R and B1, are shown intersecting X. Black arrows indicate the direction of rounding along X towards the intersection of R and B1. The sub-diagrams are labeled: H - H_v_cnr, V - V_h_cnr, D - D_v_cnr (top row) and D - D_h_cnr, H - H_d_cnr, V - V_d_cnr (bottom row).](74d23510f27b21403a7be84820821863_img.jpg)
+
+Figure 38: Examples of rounding policy for 3-arc mode spatial induction. The figure consists of six sub-diagrams arranged in a 2x3 grid. Each sub-diagram shows a triangular grid of points with a central root arc X. Two source arcs, R and B1, are shown intersecting X. Black arrows indicate the direction of rounding along X towards the intersection of R and B1. The sub-diagrams are labeled: H - H\_v\_cnr, V - V\_h\_cnr, D - D\_v\_cnr (top row) and D - D\_h\_cnr, H - H\_d\_cnr, V - V\_d\_cnr (bottom row).
+
+**Figure 38 – Examples of rounding policy for 3-arc mode spatial induction when the inducing line intersects the root arc  $X$  at its centre. The direction of rounding is highlighted by the black arrows**
+
+### 10.4.6 Image boundary handling for TriBPT
+
+For the TriBPT case, a set of implied breaks are assumed for arcs that intersect the right and bottom image boundaries. As described in 7.1, the rectangular region of image samples, is defined by  $(x_o, y_o)$  for the upper left hand corner and  $(x_l - 1, y_l - 1)$  for the lower right hand corner. Implied breaks are placed on arcs that intersect the right vertical boundary at  $x_l - 1$  or the bottom horizontal boundary at  $y_l - 1$ .
+
+Possible break positions for implied breaks are denoted by  $VrtBndry\_breakposition$  and  $HzrBndry\_breakposition$  corresponding to the right-vertical boundary and the bottom-horizontal boundary respectively, and are specified below.
+
+$$VrtBndry\_breakposition = (x_l - 1) + 2^{-(F_B+1)}$$
+
+$$HzrBndry\_breakposition = (y_l - 1) + 2^{-(F_B+1)}$$
+
+NOTE 1 – These implied breaks are never explicitly communicated but assumed to exist and utilized to adapt the transform for arcs that intersect the right and bottom image boundaries.
+
+NOTE 2 – The implied break positions  $VrtBndry\_breakposition$  and  $HzrBndry\_breakposition$  are located outside the image region at one tick point away from the image boundary intersect.
+
+As an initialization step, for all resolution levels  $r$ , an arc centred at location  $\mathbf{p}$  that crosses the right or bottom image boundary is set to type  $t_b(\mathbf{p}) = 0$ .
+
+The set of implied breaks include implied vertices on arcs at the coarsest resolution level  $r = N_L$ , located at positions  $VrtBndry\_breakposition$  or  $HzrBndry\_breakposition$ , depending on the image boundary that an arc intersects.
+
+At finer resolution levels  $r < N_L$ , breaks on non-root arcs are determined by direct induction.
+
+Root arcs are subject to the 4-arc mode spatial induction procedure. For vertical or diagonal root arcs that intersect the horizontal image boundary, if spatial induction results in a break that has a location that is different to *HrzBndry\_breakposition* then implied vertices are placed on root arcs of the 4-span that intersect the image boundaries. Similarly, for horizontal or diagonal root arcs that intersect the vertical image boundary, if spatial induction results in a break that has a location that is different to *VrtBndry\_breakposition* then implied vertices are placed on root arcs of the 4-span that intersect the image boundaries.
+
+NOTE 3 – 4-arc mode spatial induction, induces two breaks onto root arcs. If either of these two induced breaks do not correctly model the image boundary then spatial induction is abandoned and implied vertices are placed on root arcs that intersect the image boundary. The need for such implied vertices on root arcs is most obvious at 4-span arrangements that contain the bottom right corner of the image region.
+
+# Annex A
+
+## Codestream syntax
+
+(This annex forms an integral part of this Recommendation | International Standard)
+
+## A.1 General
+
+This annex specifies the extensions and constraints to the codestream syntax specified in Rec. ITU-T T.800 | ISO/IEC 15444-1 necessary to support breakpoint components and breakpoint-dependent spatial wavelet transforms. Table A.1 lists the marker segments affected by these extensions and constraints.
+
+Table A.1 – Extensions and constraints to marker segments specified in Rec. ITU-T T.800 | ISO/IEC 15444-1 and new marker segments specified in this Recommendation | International Standard
+
+| Extensions to marker segments | Constraints to marker segments | New marker segments |
+|-------------------------------|--------------------------------|---------------------|
+| CAP, COD, COC                 | SIZ                            | HDT                 |
+
+Unless specified otherwise in the following clauses, the syntax of a codestream that conforms to this Recommendation | International Standard shall conform to Rec. ITU-T T.800 | ISO/IEC 15444-1, together with any other signalled capability specified in this Recommendation | International Standard.
+
+In the tables of this annex, the symbol "r" denotes bits that are reserved, and the symbol "x" denotes bits whose value can be either 0 or 1.
+
+## A.2 SIZ marker segment
+
+Bit 14 of Rsiz shall be equal to 1.
+
+## A.3 CAP marker segment
+
+The Capability (CAP) marker segment shall be present.
+
+Bit 17 of Pcap shall be equal to 1.
+
+Table A.2 defines values for the Ccap<sup>17</sup> field.
+
+Table A.2 – Ccap<sup>17</sup> syntax and semantics
+
+| Values (bits) |      |      |      | Capability                                                                                                                                  |
+|---------------|------|------|------|---------------------------------------------------------------------------------------------------------------------------------------------|
+| MSB           |      |      | LSB  |                                                                                                                                             |
+| 1xxx          | x000 | 0000 | xxxx | One or more QuadBPT breakpoint components exist                                                                                             |
+| 0xxx          | x000 | 0000 | xxxx | No component is a QuadBPT breakpoint component                                                                                              |
+| x1xx          | x000 | 0000 | xxxx | One or more TriBPT breakpoint components exist                                                                                              |
+| x0xx          | x000 | 0000 | 0000 | No component is a TriBPT breakpoint component                                                                                               |
+| 1x1x          | x000 | 0000 | xxxx | One or more components may employ QuadBPT based breakpoint-dependent wavelet transforms (BPA-DWT)                                           |
+| xx0x          | x000 | 0000 | xxxx | No component employs a QuadBPT based BPA-DWT                                                                                                |
+| x1x1          | x000 | 0000 | mmmm | One or more components may employ TriBPT based breakpoint-dependent wavelet transforms (BPA-DWT) and no MAX_WDG parameter is larger than m. |
+| xxx0          | x000 | 0000 | 0000 | No component employs a TriBPT based BPA-DWT                                                                                                 |
+| xxxx          | 1000 | 0000 | xxxx | One or more breakpoint components may have BPT_INTER = 1 (inter-band coding mode)                                                           |
+| xxxx          | 0000 | 0000 | xxxx | All breakpoint components have BPT_INTER = 0                                                                                                |
+| xxxx          | xrrr | rrrr | xxxx | All 7-bit values r other than 0 are reserved for future use by ITU-T   ISO/IEC.                                                             |
+
+## A.4 Hierarchical data type (HDT) marker segment
+
+**Function:** Provides a *hierarchical data type identifier* for each component identified in the SIZ marker segment.
+
+**Usage:** Main header. Codestreams conforming to this Recommendation | International Standard shall have one and only one HDT marker segment, which shall appear prior to any COD, COC, QCD or QCC marker segment. Placement of the HDT marker segment shall satisfy any additional constraints as specified by Rec. ITU-T T.800 | ISO/IEC 15444-1 or required by any other signalled capabilities.
+
+**Length:** Variable, depending on the number of components.
+
+Figure A.1 illustrates the syntax of the hierarchical data type marker segment.
+
+![Figure A.1: Hierarchical data type syntax diagram. It shows a sequence of fields: HDT, Lhdt, Ihdt^1, followed by a shaded box representing a variable number of Ihdt^N fields, and finally Ihdt^N. Below the diagram is the reference T.816(23).](4260aa4a7ece77c411597094c9d197bd_img.jpg)
+
+T.816(23)
+
+Figure A.1: Hierarchical data type syntax diagram. It shows a sequence of fields: HDT, Lhdt, Ihdt^1, followed by a shaded box representing a variable number of Ihdt^N fields, and finally Ihdt^N. Below the diagram is the reference T.816(23).
+
+**Figure A.1 – Hierarchical data type syntax**
+
+**HDT:** Marker Code. Table A.3 shows the size and values of the symbol and parameters for the HDT marker segment.
+
+**Lhdt:** Length of the HDT marker segment (not including the marker). The length shall satisfy
+
+$$\text{Lhdt} = 2 + \text{Csiz bytes},$$
+
+where Csiz is the number of components signalled in the SIZ marker segment.
+
+**Ihdt<sup>i</sup>:** Ihdt<sup>i</sup> are 8-bit integers that hold the hierarchical-type identifier. Allowed values and interpretations for these integers are provided in Table A.4.
+
+**Table A.3 – Hierarchical data type parameter values**
+
+| Parameter         | Size (bits) | Value         |
+|-------------------|-------------|---------------|
+| HDT               | 16          | 0xFF7A        |
+| Lhdt              | 16          | 3-16386       |
+| Ihdt <sup>i</sup> | 8           | See Table A.4 |
+
+**Table A.4 – Allowed values for Ihdt<sup>i</sup>**
+
+| Value (bits) |      | Hierarchical data type identifier |
+|--------------|------|-----------------------------------|
+| MSB          | LSB  |                                   |
+| 0000         | 0000 | Non-hierarchical component        |
+| 0000         | 0001 | QuadBPT breakpoint component      |
+| 0000         | 0010 | TriBPT-LR breakpoint component    |
+| 0000         | 0011 | TriBPT-RL breakpoint component    |
+|              |      | All other values reserved         |
+
+## A.5 COD and COC marker segments
+
+The COD and COC marker segments defined in Rec. ITU-T T.800 | ISO/IEC 15444-1 are modified as follows.
+
+For a given COD or COC marker segment, if the Scod or Scoc value has bit 5 equal to 0, then the marker segment has no SXcod field. However, if the Scod or Scoc value has bit 5 equal to 1, then the marker segment has a 16-bit SXcod field that immediately follows the SPcod or SPcoc field.
+
+For a given COD or COC marker segment, if the 16-bit SXcod field is present and has bit 15 equal to 1 then the marker segment has a 32-bit SEcod field. Otherwise, the marker segment has no SEcod field.
+
+The modified syntax for COD and COC marker segments is shown in Figure A.2 and Figure A.3, while Table A.5 shows the interpretation for bit 5 of Scod and Scoc.
+
+![](0af1ba85ab6e4e50befbef3d63e017dc_img.jpg)
+
+|     |      |      |       |       |       |       |
+|-----|------|------|-------|-------|-------|-------|
+| COD | Lcod | Scod | SGcod | SPcod | SXcod | SEcod |
+|-----|------|------|-------|-------|-------|-------|
+
+T.816(23)
+
+Figure A.2 – Coding style default syntax
+
+![](0f6e3cdce0f01d6ccceabcced508bb5b_img.jpg)
+
+|     |      |      |       |       |       |
+|-----|------|------|-------|-------|-------|
+| COC | Lcoc | Scoc | SPcoc | SXcod | SEcod |
+|-----|------|------|-------|-------|-------|
+
+T.816(23)
+
+Figure A.3 – Coding style component syntax
+
+Table A.5 – Scod and Scoc semantics for bit 5
+
+| Value (bits) |      | Interpretation                                                                                                                            |
+|--------------|------|-------------------------------------------------------------------------------------------------------------------------------------------|
+| MSB          | LSB  |                                                                                                                                           |
+| xx0x         | xxxx | No SXcod field. Breakpoint components use $F_{\text{vtx}} = 1$ , $F_b = 2$ and BPT_INTER = 0. Breakpoint-dependent transform is not used. |
+| xx1x         | xxxx | SXcod field is present                                                                                                                    |
+
+Allowed values for the SXcod field are shown in Table A.6.
+
+NOTE 1 – Bit-fields marked with an "x" in Table A.6 are defined in Rec. ITU-T T.801 | ISO/IEC 15444-2, with which this Recommendation | International Standard is compatible. For bit fields marked with an "r", values other than 0 are reserved.
+
+This Recommendation | International Standard defines one 12-bit value, three 4-bit values and one 1-bit value within the 32-bit SEcod field, as shown in Table A.7. These values are used to communicate coding parameters for breakpoint components, as well as breakpoint-dependent transform parameters for non-breakpoint components.
+
+NOTE 2 – In cases where a codestream contains only breakpoint and breakpoint-dependent components, a single COD marker segment with one SEcod field may be sufficient to communicate all coding parameters. More generally, it can be necessary to include additional COC marker segments, perhaps with their own SEcod fields.
+
+The  $D_c$  value communicated via SEcod is relevant only to non-breakpoint components. If SEcod is present and  $D_c$  is not equal to zero,  $D_c$  shall be the zero-based index of a breakpoint component and non-breakpoint components described by the COD or COC marker segment use a breakpoint-dependent spatial wavelet transform that depends on breakpoint component  $D_c$ , as expounded in clause 8. Otherwise, the component is processed in accordance with Rec. ITU-T T.800 | ISO/IEC 15444-1, combined with any other signalled capability. The MAX\_WDG value in SEcod is relevant only if  $D_c$  is non-zero and identifies a TriBPT component as the breakpoint component on which non-breakpoint components depend; in that case, MAX\_WDG constrains the search for gradient evaluation in 8.2.5.
+
+NOTE 3 – Breakpoint-dependent spatial wavelet transforms can only depend on breakpoint components with indices in the range  $1 \leq D_c \leq 2047$ .
+
+The  $F_b$  and  $F_{\text{vtx}}$  parameters and the BPT\_INTER flag communicated via SEcod are relevant only to breakpoint components. BPT\_INTER determines whether or not the inter-band coding mode is used to perform the breakpoint decoding steps described in clause 8. If the SEcod field is not present with the COD or COC marker segment that describes a breakpoint component's coding parameters, then the breakpoint component shall use the default values of  $F_{\text{vtx}} = 1$ ,  $F_b = 2$  and BPT\_INTER = 0.
+
+Table A.6 – SXcod bit fields specified by this Recommendation | International Standard
+
+| Value (bits) |           | Interpretation                                                                                                                            |
+|--------------|-----------|-------------------------------------------------------------------------------------------------------------------------------------------|
+| MSB          | LSB       |                                                                                                                                           |
+| 0rrrr        | rrrr rrxx | No SEcod field. Breakpoint components use $F_{\text{vtx}} = 1$ , $F_b = 2$ and BPT_INTER = 0. Breakpoint-dependent transform is not used. |
+| 1rrrr        | rrrr rrxx | SEcod field is present.                                                                                                                   |
+
+Table A.7 – Allowed values for the SEcod field
+
+| Value (bits) |      |      |      |      |      |      |      | Interpretation                                             |
+|--------------|------|------|------|------|------|------|------|------------------------------------------------------------|
+| MSB          |      |      |      |      |      |      | LSB  |                                                            |
+| rrrr         | rrrr | xxxx | xxxx | mmmm | DDDD | DDDD | DDDD | Dependency component index $D_c$ with MAX_WDG value $m$ .  |
+| rrrr         | rrrr | xxxx | xxxx | rrrr | 0000 | 0000 | 0000 | All 4-bit values $r$ other than 0 are reserved             |
+| rrrr         | rrrr | xxxx | VVVV | xxxx | xxxx | xxxx | xxxx | Value of V, in the range 0-15, such that $F_{vtx} = V + 1$ |
+| rrrr         | rrrr | BBBB | xxxx | xxxx | xxxx | xxxx | xxxx | Value of B, in the range 0-15, such that $F_b = B + 1$     |
+| rrrr         | rrrI | xxxx | xxxx | xxxx | xxxx | xxxx | xxxx | Value of BPT_INTER = I                                     |
+
+For breakpoint components, bit 0 (selective arithmetic coding bypass mode) and bit 3 (vertically causal context mode) of the code-block style field in SPcod and SPcoc shall be ignored. For breakpoint components, the transformation field in SPcod and SPcoc shall also be ignored.
+
+For breakpoint-dependent components (those with  $D_c \neq 0$ ), the transformation field in SPcod and SPcoc shall be reinterpreted to indicate whether the breakpoint-dependent transformation process is reversible or irreversible, as shown in Table A.8. In this Recommendation | International Standard, reversible breakpoint-dependent transformation is available only when  $D_c$  identifies a TriBPT component.
+
+Table A.8 – Transformation for the SPcod and SPcoc parameters when  $D_c \neq 0$ 
+
+| Value (bits) |     | Transformation type                                                |
+|--------------|-----|--------------------------------------------------------------------|
+| MSB          | LSB |                                                                    |
+| 0000 0000    |     | Breakpoint-dependent transform is irreversible                     |
+| 0000 0001    |     | Breakpoint-dependent transform is reversible – TriBPT case only    |
+| rrrr rrrx    |     | All 7-bit values for r other than 0 are reserved when $D_c \neq 0$ |
+
+# Annex B
+
+## Hierarchical breakpoint encapsulation and raw file format
+
+(This annex does not form an integral part of this Recommendation | International Standard)
+
+## B.1 General
+
+This annex describes encapsulations for breakpoint component data that can be used in conjunction with this Recommendation | International Standard. Encoding and decoding implementations can potentially find it useful to adopt these encapsulations for their internal representation of breakpoint information, during analysis and reconstruction of breakpoint components, as well as their block encoding and decoding operations.
+
+In addition to breakpoint type  $t$ , precision  $P$  and tick-point values  $k$ , the encapsulations here are able to capture break significance information that can be used by an encoder to establish meaningful quality layer boundaries for breakpoint media. The relative significance of breaks can also be derived by a decoder that processes a codestream that conforms to this Recommendation | International Standard and recorded using the encapsulations described here. In this way, breakpoint data can be decoded, processed and re-encoded, while preserving not only the break locations but other attributes that are important for scalability.
+
+## B.2 Raster organization of breakpoints
+
+Whereas regular image samples can simply be arranged in an array and rasterized into a linear file structure, breakpoint components are inherently hierarchical. That is to say, the hierarchy needs to be encapsulated as part of the representation, rather than derived from it. One way to do this is to rasterize each resolution level in the hierarchy separately and then concatenate the results.
+
+Another approach is to adopt an interleaved representation. As explained in 7.1, the breakpoint component occupies a rectangular region defined by its (inclusive) upper left corner at  $(x_o, y_o)$  and (exclusive) lower right bound at  $(x_l, y_l)$ , so that the highest resolution level has  $Y = y_l - y_o$  rows, each of which has  $X = x_l - x_o$  grid-points. Arc breakpoints are associated with the grid-point at the centre of each arc, so that there are at most  $Y \times X$  breakpoints at the highest resolution level.
+
+For the TriBPT arrangements, there are only 3 arcs for every 4 grid-points, as shown in Figure 1. Moreover, the grid-points that have no arc breakpoint data within a resolution are those whose coordinates are both divisible by 2; these are exactly the grid-points that define the next lower resolution level. This property allows the entire breakpoint component to be interleaved into a single  $Y \times X$  array. The entry on row  $m \in [0, Y)$  of this array in column  $c \in [0, X)$  has absolute coordinates  $(x_o + n, y_o + m)$  and breakpoint data is embedded in the single component array as follows:
+
+- breakpoint data for the **horizontal** arc in cell  $(c_x, c_y)$  at depth  $d \geq 1$  is recorded at location  $[m, n]$  such that  $(x_o + n, y_o + m) = (c_x 2^d + 2^{d-1}, c_y 2^d)$ ;
+- breakpoint data for the **vertical** arc in cell  $(c_x, c_y)$  at depth  $d \geq 1$  is recorded at location  $[m, n]$  such that  $(x_o + n, y_o + m) = (c_x 2^d, c_y 2^d + 2^{d-1})$ ; and
+- breakpoint data for the **diagonal** arc in cell  $(c_x, c_y)$  at depth  $d \geq 1$  is recorded at location  $[m, n]$  such that  $(x_o + n, y_o + m) = (c_x 2^d + 2^{d-1}, c_y 2^d + 2^{d-1})$ .
+
+This interleaved representation has a number of desirable attributes. A single array, whose size depends only on the full image resolution, accommodates breakpoints at all resolution levels to any depth  $d$ . Moreover, breakpoint values can be progressively encoded or decoded, from top to bottom, while reading or writing a file (or memory buffer) linearly; that is, the representation does not require random access to data segments representing different resolution levels.
+
+For the QuadBPT arrangement, there are 4 arcs for every 4 grid-points, as shown in Figure 1, so the above encapsulation is not sufficient. Nonetheless, the above-mentioned desirable attributes can be preserved by extending each row within the  $Y \times X$  array with exactly  $\lceil \frac{X}{2} \rceil$  extra breakpoints. In the interleaved QuadBPT representation, breakpoint data is embedded in this extended array as follows:
+
+- breakpoint data for the **horizontal non-root** arc in cell  $(c_x, c_y)$  at depth  $d \geq 1$  is recorded at location  $[m, n]$  such that  $(x_o + n, y_o + m) = (c_x 2^d + 2^{d-1}, c_y 2^d)$  in the main body of the array ( $0 \leq n < X$ );
+- breakpoint data for the **vertical non-root** arc in cell  $(c_x, c_y)$  at depth  $d \geq 1$  is recorded at location  $[m, n]$  such that  $(x_o + n, y_o + m) = (c_x 2^d, c_y 2^d + 2^{d-1})$  in the main body of the array ( $0 \leq n < X$ );
+
+- breakpoint data for the **vertical root** arc in cell  $(c_x, c_y)$  at depth  $d \geq 1$  is recorded at location  $[m, n]$  such that  $(x_o + n, y_o + m) = (c_x 2^d + 2^{d-1}, c_y 2^d + 2^{d-1})$  in the main body of the array ( $0 \leq n < X$ ); and
+- breakpoint data for the **horizontal root** arc in cell  $(c_x, c_y)$  at depth  $d \geq 1$  is recorded at location  $[m, X + n]$  such that  $(\lfloor \frac{x_o}{2^d} \rfloor + n, y_o + m) = (c_x, c_y 2^d + 2^{d-1})$ , in the extension part of the array ( $X \leq X + n < X + \lfloor \frac{X}{2} \rfloor$ ).
+
+NOTE – All rows of the array have extension segments of length  $\lfloor \frac{X}{2} \rfloor$ , even though most of the extension elements are not used. Only about half the rows contribute breakpoints (horizontal root arc breakpoints) to their extension segment, and those rows that are associated with root arcs deep in the hierarchy use only a small fraction of the available extension entries. There is no interleaving within the extension segments, so breakpoint values from the relevant resolution level are packed tightly together, except that the first entry is not used if  $2^d \lfloor \frac{x_o}{2^d} \rfloor + 2^{d-1} < x_o$ .
+
+The QuadBPT encapsulation described above is far from unique, but it is intended to be a simple extension of the desirable TriBPT encapsulation.
+
+## B.3 16- and 32-bit packed breakpoint values
+
+Figure B.1 illustrates two packing arrangements of the breakpoint information associated with an arc, within integer values, so that a breakpoint component can be described by a single array of integers. Two arrangements are presented here: one involving 32-bit integers; the other involving only 16-bit integers.
+
+The  $k_b$  parameter, that identifies the tick-point location of a break within arc  $b$ , appears in the most significant bit positions of a field  $K$  that has  $K_{\text{bits}} = 6$  bits (16-bit form) or  $K_{\text{bits}} = 18$  bits (32-bit form). This means that the 16-bit form is capable of representing breakpoint components with at most 6 resolution levels, since  $K_{\text{bits}}$  must be no smaller than  $d + F_B$ ; with  $F_B = 1$ , at most 5 resolution levels can be used.
+
+The break-type parameter  $t_b$  occupies a 2-bit field  $T$ .
+
+The break-precision parameter  $P_b$  occupies a field  $P$  with  $P_{\text{bits}} = 3$  bits (16-bit form) or  $P_{\text{bits}} = 5$  bits (32-bit form). This means that the 16-bit form is capable of representing vertices with at most 7 bits of precision, corresponding to at most  $2^6$  distinct original locations within an arc; this mirrors the fact that the  $K_b$  field can represent at most  $2^6$  distinct tick-points in the 16-bit form.
+
+NOTE 1 – vertices are represented through the tick-points  $k_b$  to which they are mapped, as per Formula (8).
+
+The extrapolation qualifier that affects breakpoint adaptive transforms based on the TriBPT breakpoint arrangements is provided via an  $E$  field with  $E_{\text{bits}} = 2$  bits. With the QuadBPT arrangement, the  $E$  field is reserved, but should be set to 0.
+
+The least significant bit positions represent a "quality" value  $Q_b$  that provides an estimate of the distortion implications of quantizing the breakpoint location. The value of  $Q_b$  is described in terms of an exponent QE and a mantissa QM, where the exponent is represented with  $QE_{\text{bits}} = 3$  bits (16-bit form) or  $QE_{\text{bits}} = 4$  bits (32-bit form) and the mantissa is represented with  $QM_{\text{bits}} = 1$  bit (32-bit form only). The quality value  $Q_b$  is found from these exponent and mantissa values using
+
+$$Q_b = \begin{cases} 2^{QE - QE_{\text{lim}}} \cdot \left(1 + \frac{QM + 0.5}{QM_{\text{lim}}}\right) & \text{if } QM_{\text{bits}} \neq 0 \\ 2^{QE - QE_{\text{lim}}} \cdot (1 + 0.5) & \text{if } QM_{\text{bits}} = 0 \end{cases}, \text{ where } QE_{\text{lim}} = 2^{QE_{\text{bits}}} \text{ and } QM_{\text{lim}} = 2^{QM_{\text{bits}}}$$
+
+NOTE 2 –  $Q_b$  always lies in the open unit interval  $(0,1)$ .
+
+$Q_b$  can be understood as modelling the squared magnitude of the "jumps" in the underlying data that are transformed and coded with the aid of breakpoints – i.e., using breakpoint-dependent transforms. If the breakpoint-dependent data are imagery,  $Q_b$  would typically be the squared difference in the image sample values found at either end of the arc, or any of its sub-arcs, whichever provides the larger value for  $Q_b$ . If the breakpoint-dependent data are motion vectors or disparity values used for warping imagery,  $Q_b$  would typically be the squared differences between the motion/disparity compensated predictions formed using the motion/disparity values found at either end of the arc, or any of its sub-arcs, whichever provides the larger value for  $Q_b$ .
+
+With this interpretation of  $Q_b$ , a reasonable model for the squared error distortion that might arise if a decoder recovers only the  $q \geq 0$  most significant bits of a vertex  $V_b$  is  $D_{b,q} = 2^{2d-q} \cdot Q_b$ , if  $b$  is a non-root arc at depth  $d$ , with a QuadBPT arrangement. If  $b$  is a root arc at level  $d$ , or if using one of the TriBPT arrangements, one can expect a somewhat smaller distortion, due to the reduced region of influence of the arc whose breakpoint is being quantized. The values  $Q_b$  and  $D_{b,q}$  here represent the impact of breakpoint quantization on image sample values that have been normalized to a unit dynamic range from  $-0.5$  to  $0.5$ . This imparts  $Q_b$  with a meaning that is independent of the bit-depth associated with image components that depend on the breakpoint component.
+
+Encoders can use the  $Q_b$  value when deciding the bit-plane in which each vertex should first become significant, and in arranging breakpoint code-block coding passes within quality layers. Encoders can estimate  $Q_b$  values using a hierarchical
+
+analysis strategy, in which initial estimates are formed only for the finest arcs, with length 2, and these estimates are combined to form distortion estimates for longer arcs that are found to be involved in inducing the finer arcs. Decoders can use the most significant bit-plane of each decoded vertex to recover an approximate  $Q_b$  value – or at least its exponent QE.
+
+NOTE 3 – The representation here is quite redundant, in that it can preserve information about induced breaks, extrapolation flags and even induction blocks, all of which are ultimately derived from vertices that are typically very sparse. This derived information can be discovered during the decoding and synthesis of a breakpoint component, and it is important for breakpoint-adaptive transforms. Encoders that process breakpoint data in this form are recommended to check that the derived information is consistent with the vertex values, meaning that a decoder will recover the same derived information.
+
+![Diagram showing bit field layouts for 16-bit and 32-bit packed breakpoint representations. It maps bit positions to specific fields: K (break position), T (break type), P (break priority/ambivalence), E (extrapolation qualifier), QE (quality exponent), and QM (quality mantissa).](694df81535f89c7bfb9ef0df6f130dc0_img.jpg)
+
+16-bit form      32-bit form
+
+$K_5$        $K_{17}$
+
+$K_4$        $K_{16}$
+
+$K_3$        $K_{15}$
+
+$K_0$        $K_0$        $d + Fb$  MSB's hold  $k$ , where relative break position is  $(2k + 1)2^{-(1+d+Fb)}$
+
+Remaining bits of  $K$  should be 0
+
+$T_1$        $T_1$
+
+$T_0$        $T_0$       3 = vertex; 2 = directly induced; 1 = spatially induced; 0 = no break
+
+$P_4$
+
+$P_3$        $P \geq 2$  for a vertex ( $T = 3$ )
+
+$P_2$        $P_2$        $P \geq 1$  for induced breaks ( $T = 1, 2$ ), where  $P = 1$  is an ambivalent break
+
+$P_1$        $P_1$        $P = 0$  for indefinite breaks ( $T = 1, 2$ )
+
+$P_0$        $P_0$        $P = 1, T = 0$  means no break with induction block hint
+
+$P = 0, T = 0$  means no break
+
+$E_1$        $E_1$
+
+$E_0$        $E_0$       Extrapolation qualifier  $E$  for TriBPT arrangements (Reserved = 0 for QuadBPT)
+
+$QE_3$
+
+$QE_2$        $QE_2$
+
+$QE_1$        $QE_1$       Quality exponent
+
+$QE_0$        $QE_0$
+
+$QM_0$        $QM_0$       Quality mantissa
+
+T.816(23)
+
+Diagram showing bit field layouts for 16-bit and 32-bit packed breakpoint representations. It maps bit positions to specific fields: K (break position), T (break type), P (break priority/ambivalence), E (extrapolation qualifier), QE (quality exponent), and QM (quality mantissa).
+
+**Figure B.1 – Bit fields within 16- and 32-bit packed breakpoint representations. The most significant bit of the 16- or 32-bit integer, as appropriate, is shown at the top of the figure, while the least significant bit appears at the bottom**
+
+## B.4 A raw file format for breakpoints
+
+The raster organization and packed breakpoint bitfields described in B.2 and B.3 are not limited to use in files; they can be valuable in-memory representations for the implementation of breakpoint component encoding and decoding procedures. For a file-based representation, it is desirable to prepend the array of rasterized breakpoint integers with a header that communicates the following minimal set of parameters:
+
+1. The breakpoint arrangement, being one of QuadBPT, TriBPT-LR or TriBPT-RL;
+2. The width  $X$  and height  $Y$  of the breakpoint component;
+3. The anchor coordinates  $x_0$  and  $y_0$  that determine the number of breakpoints at each resolution, along with how breakpoints are embedded within the interleaved rasterizations described in B.2;
+4. The number of bits  $B$  used to represent each breakpoint where  $B$  is divisible by 8, in the range 16 to 64; and
+
+5. The number of bits in each of the constituent bit-fields  $K$ ,  $P$ ,  $E$  and  $QE$ , as introduced in B.3, such that  $(B - 2 - K_{\text{bits}} - P_{\text{bits}} - E_{\text{bits}} - QE_{\text{bits}}) = QM_{\text{bits}} \geq 0$  is the number of bits left for the quality mantissa field  $QM$ , in the LSBs of each breakpoint integer.
+
+The following text header format can be used to address all the issues mentioned above, while also allowing both little-endian and big-endian representations. It involves 7 tokens, separated by whitespace characters space, tab, carriage return or linefeed, and terminated by a single linefeed character. Specifically, the text header is defined as follows, using the ABNF notation specified in IETF RFC 2234 [1].
+
+```
+header = magic WS type WS Xval WS Yval WS X0val WS Y0val WS format LF
+magic = %x42 %x50 %x54
+type = "Quad" / "TriLR" / "TriRL"
+format = Bbits endian "=" %x4B Kbits %x50 Pbits %x45 Ebits %x51 Qbits
+Bbits = "16" / "24" / "32" / "40" / "48" / "56" / "64"
+endian = littlendian / bigendian
+littlendian = %x4c
+bigendian = %x42
+WS = 1*(SPACE / TAB / CR / LF)
+Xval = NZDIGIT *DIGIT
+Yval = NZDIGIT *DIGIT
+X0val = 1*DIGIT
+Y0val = 1*DIGIT
+Kbits = NZDIGIT *DIGIT
+Pbits = NZDIGIT *DIGIT
+Ebits = "0" / "2"
+Qbits = DIGIT
+SPACE = %x20
+TAB = %x09
+CR = %x0D
+LF = %x0A
+NZDIGIT = %x31-39
+DIGIT = %x30 / NZDIGIT
+```
+
+NOTE –
+
+<magic> is the uppercase string "BPT" in the character encoding specified in ISO/IEC 10646 [2].
+
+The <type> string is case insensitive
+
+<Xval>, <Yval>, <X0val> and <Y0val> represent width  $X$ , height  $Y$  and origin  $x_0$  and  $y_0$ , as described in B.2.
+
+<Kbits>, <Pbits>, <Ebits> and <Qbits> represent the values of  $K_{\text{bits}}$ ,  $P_{\text{bits}}$ ,  $QE_{\text{bits}}$  and  $QE_{\text{bits}}$ , respectively.
+
+<Bbits> is the precision  $B$  such that each breakpoint is represented by  $B/8$  bytes and  $B \geq 2 + K_{\text{bits}} + P_{\text{bits}} + E_{\text{bits}} + QE_{\text{bits}}$ .
+
+The LF character that follows <format> separates the header information from breakpoint data.
+
+For the interleaved TriBPT arrangements of B.2, the final LF character of the header is followed by  $Y$  rows of  $X$   $B$ -bit integers, in raster order and tightly packed. For the interleaved QuadBPT arrangement of B.2, the final LF character of the header is followed by  $Y$  rows of  $(X + \lfloor \frac{X}{2} \rfloor)$   $B$ -bit integers, in raster order and tightly packed.
+
+The following two example headers employ the 16- and 32-bit breakpoint representations described in B.3, for a breakpoint component with 3840 columns and 2160 rows. In each case, the header is formatted into three lines, which is recommended for human readability, but not required.
+
+Example 1: 16-bit little-endian representation of TriBPT-LR breakpoints with anchor point (0,0)
+
+```
+BPT TriLR
+3840 2160 0 0
+16L=K6P3E2Q3
+```
+
+Example 2: 32-bit big-endian representation of QuadBPT breakpoints with anchor point (0,0)
+
+```
+BPT Quad  
+3840 2160 0 0  
+32B K18P5E2Q4
+```
+
+# Bibliography
+
+- [1] IETF RFC 2234 (1997), *Augmented BNF for Syntax Specifications: ABNF*.
+- [2] ISO/IEC 10646:2020, *Information technology – Universal Coded Character Set (UCS)*.
+
+
+
+
+
+# SERIES OF ITU-T RECOMMENDATIONS
+
+|                 |                                                                                                                                                           |
+|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Series A        | Organization of the work of ITU-T                                                                                                                         |
+| Series D        | Tariff and accounting principles and international telecommunication/ICT economic and policy issues                                                       |
+| Series E        | Overall network operation, telephone service, service operation and human factors                                                                         |
+| Series F        | Non-telephone telecommunication services                                                                                                                  |
+| Series G        | Transmission systems and media, digital systems and networks                                                                                              |
+| Series H        | Audiovisual and multimedia systems                                                                                                                        |
+| Series I        | Integrated services digital network                                                                                                                       |
+| Series J        | Cable networks and transmission of television, sound programme and other multimedia signals                                                               |
+| Series K        | Protection against interference                                                                                                                           |
+| Series L        | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant |
+| Series M        | Telecommunication management, including TMN and network maintenance                                                                                       |
+| Series N        | Maintenance: international sound programme and television transmission circuits                                                                           |
+| Series O        | Specifications of measuring equipment                                                                                                                     |
+| Series P        | Telephone transmission quality, telephone installations, local line networks                                                                              |
+| Series Q        | Switching and signalling, and associated measurements and tests                                                                                           |
+| Series R        | Telegraph transmission                                                                                                                                    |
+| Series S        | Telegraph services terminal equipment                                                                                                                     |
+| <b>Series T</b> | <b>Terminals for telematic services</b>                                                                                                                   |
+| Series U        | Telegraph switching                                                                                                                                       |
+| Series V        | Data communication over the telephone network                                                                                                             |
+| Series X        | Data networks, open system communications and security                                                                                                    |
+| Series Y        | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities                               |
+| Series Z        | Languages and general software aspects for telecommunication systems                                                                                      |
\ No newline at end of file
diff --git a/marked/T/T-REC-T.834-201410-I_PDF-E/14a22f23ced8ba1d63ece69861dbaacc_img.jpg b/marked/T/T-REC-T.834-201410-I_PDF-E/14a22f23ced8ba1d63ece69861dbaacc_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..ee92401e370818a1e17538368beefb4810ac5a63
--- /dev/null
+++ b/marked/T/T-REC-T.834-201410-I_PDF-E/14a22f23ced8ba1d63ece69861dbaacc_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:f80ee07b25c639b616055060c83cb691bf4c4709485533c4d6c449154a92c6f9
+size 4160
diff --git a/marked/T/T-REC-T.834-201410-I_PDF-E/raw.md b/marked/T/T-REC-T.834-201410-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..bf4dce192764d9ced815379b9bab03ab6fd34582
--- /dev/null
+++ b/marked/T/T-REC-T.834-201410-I_PDF-E/raw.md
@@ -0,0 +1,1400 @@
+
+
+# ITU-T
+
+TELECOMMUNICATION  
+STANDARDIZATION SECTOR  
+OF ITU
+
+# T.834
+
+(10/2014)
+
+SERIES T: TERMINALS FOR TELEMATIC SERVICES
+
+Still-image compression | JPEG XR
+
+# --- Information technology – JPEG XR image coding system – Conformance testing
+
+Recommendation ITU-T T.834
+
+# ITU-T T-SERIES RECOMMENDATIONS **TERMINALS FOR TELEMATIC SERVICES**
+
+|                                                     |                    |
+|-----------------------------------------------------|--------------------|
+| Facsimile – Framework                               | T.0–T.19           |
+| Still-image compression – Test charts               | T.20–T.29          |
+| Facsimile – Group 3 protocols                       | T.30–T.39          |
+| Colour representation                               | T.40–T.49          |
+| Character coding                                    | T.50–T.59          |
+| Facsimile – Group 4 protocols                       | T.60–T.69          |
+| Telematic services – Framework                      | T.70–T.79          |
+| Still-image compression – JPEG-1, Bi-level and JBIG | T.80–T.89          |
+| Telematic services – ISDN Terminals and protocols   | T.90–T.99          |
+| Videotext – Framework                               | T.100–T.109        |
+| Data protocols for multimedia conferencing          | T.120–T.149        |
+| Telewriting                                         | T.150–T.159        |
+| Multimedia and hypermedia framework                 | T.170–T.189        |
+| Cooperative document handling                       | T.190–T.199        |
+| Telematic services – Interworking                   | T.300–T.399        |
+| Open document architecture                          | T.400–T.429        |
+| Document transfer and manipulation                  | T.430–T.449        |
+| Document application profile                        | T.500–T.509        |
+| Communication application profile                   | T.510–T.559        |
+| Telematic services – Equipment characteristics      | T.560–T.649        |
+| Still-image compression – JPEG 2000                 | T.800–T.829        |
+| <b>Still-image compression   JPEG XR</b>            | <b>T.830–T.849</b> |
+| Still-image compression – JPEG-1 extensions         | T.850–T.899        |
+
+*For further details, please refer to the list of ITU-T Recommendations.*
+
+# Information technology – JPEG XR image coding system – Conformance testing
+
+## Summary
+
+Recommendation ITU-T T.834 has been developed jointly with ISO/IEC JTC 1 SC 29/WG 1 in a collaborative team that is referred to as the Joint Photographic Experts Group (JPEG). It will be published as a technically-aligned twin text by both organizations (ITU-T and ISO/IEC).
+
+This Recommendation | International Standard specifies tests designed to verify whether codestreams, files, encoders and decoders meet the normative requirements specified in Rec. ITU-T T.832 | ISO/IEC 29199-2 (*Information technology – JPEG XR image coding system – Image coding specification*).
+
+- A codestream (or file) can be claimed to conform to Rec. ITU-T T.832 | ISO/IEC 29199-2 if it meets the normative requirements for such codestreams (or file) specified in Rec. ITU-T T.832 | ISO/IEC 29199-2.
+- An encoder can be claimed to have codestream (or file format) conformance to Rec. ITU-T T.832 | ISO/IEC 29199-2 if the codestreams (or files) that it generates are conforming codestreams (or files).
+- A decoder can be claimed to conform to a specified subset of Rec. ITU-T T.832 | ISO/IEC 29199-2 capabilities (such as a combination of "profile" and "level" capabilities) if it can properly decode all codestreams (or files) obeying the constraints specified in Rec. ITU-T T.832 | ISO/IEC 29199-2 for the specified subset of capabilities.
+
+The tests specified in this Recommendation | International Standard provide methods for (non-exhaustive) testing of whether encoders and decoders meet these requirements.
+
+This enhancement of Rec. ITU-T T.834 | ISO/IEC 29199-4 extends and enhances the set of test streams for Rec. ITU-T T.832 | ISO/IEC 29199-2 in two ways: First, additional test streams cover features than had either not yet been tested in earlier revisions or did not exist in earlier versions in the standard. Second, extensions made to the JPEG 2000 file format of Rec. ITU-T T.802 | ISO/IEC 15444-2 allow the wrapping of JPEG XR codestreams in the JPEG 2000 file format, for which new reference streams are included.
+
+A set of data for use in such tests is provided as an electronic attachment to this Recommendation | International Standard and is an integral part thereof. This data set is also available for download from the ITU-T Test Signal Database at: <http://itu.int/net/ITU-T/sigdb/speimage/Tseries-s.htm#T.834>.
+
+## History
+
+| Edition | Recommendation | Approval   | Study Group | Unique ID*                                                                |
+|---------|----------------|------------|-------------|---------------------------------------------------------------------------|
+| 1.0     | ITU-T T.834    | 2010-01-13 | 16          | <a href="http://handle.itu.int/11.1002/1000/10648">11.1002/1000/10648</a> |
+| 2.0     | ITU-T T.834    | 2014-10-14 | 16          | <a href="http://handle.itu.int/11.1002/1000/12305">11.1002/1000/12305</a> |
+
+---
+
+\* To access the Recommendation, type the URL <http://handle.itu.int/> in the address field of your web browser, followed by the Recommendation's unique ID. For example, <http://handle.itu.int/11.1002/1000/11830-en>.
+
+## FOREWORD
+
+The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis.
+
+The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics.
+
+The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1.
+
+In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC.
+
+## NOTE
+
+In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party.
+
+## INTELLECTUAL PROPERTY RIGHTS
+
+ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process.
+
+As of the date of approval of this Recommendation, ITU had received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at <http://www.itu.int/ITU-T/ipr/>.
+
+© ITU 2015
+
+All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU.
+
+## CONTENTS
+
+|   |                                                                                           | <i>Page</i> |
+|---|-------------------------------------------------------------------------------------------|-------------|
+| 1 | Scope .....                                                                               | 1           |
+| 2 | Normative references.....                                                                 | 1           |
+|   | 2.1 Identical Recommendations   International Standards .....                             | 1           |
+|   | 2.2 Paired Recommendations   International Standards equivalent in technical content..... | 1           |
+|   | 2.3 Additional references .....                                                           | 1           |
+| 3 | Definitions .....                                                                         | 1           |
+| 4 | Abbreviations .....                                                                       | 2           |
+| 5 | Conventions .....                                                                         | 2           |
+| 6 | Conformance testing specification .....                                                   | 2           |
+|   | 6.1 General .....                                                                         | 2           |
+|   | 6.2 Procedure to test codestreams (or files).....                                         | 3           |
+|   | 6.3 Procedure to test encoders.....                                                       | 3           |
+|   | 6.4 Procedure to test decoders.....                                                       | 3           |
+| 7 | Reference data set.....                                                                   | 4           |
+|   | 7.1 General .....                                                                         | 4           |
+|   | 7.2 Reference file set BasicAndOverlap_1x1Tile.....                                       | 4           |
+|   | 7.3 Reference file set BasicAndOverlap_4x4Tile.....                                       | 5           |
+|   | 7.4 Reference file set BasicAndOverlap_2x2Tile.....                                       | 6           |
+|   | 7.5 Reference file set BandsPresent_1x1Tile.....                                          | 6           |
+|   | 7.6 Reference file set BandsPresent_4x4Tile.....                                          | 7           |
+|   | 7.7 Reference file set Varied_QP .....                                                    | 7           |
+|   | 7.8 Reference file set Varied_Internal_Color_Format .....                                 | 8           |
+|   | 7.9 Reference file set Output_Bitdepth_16 .....                                           | 8           |
+|   | 7.10 Reference file set Special_QP .....                                                  | 9           |
+|   | 7.11 Reference file set Flags_And_Tiles .....                                             | 9           |
+|   | 7.12 Reference file set Entropy_Table_Coverage.....                                       | 10          |
+|   | 7.13 Reference file set Shift_Bits.....                                                   | 11          |
+|   | 7.14 Reference file set MBLevel_QP_Coverage .....                                         | 11          |
+|   | 7.15 Reference file set Output_Color_Format_Baseline.....                                 | 12          |
+|   | 7.16 Reference file set Output_Color_Format_Main .....                                    | 12          |
+|   | 7.17 Reference file set Output_Color_Format_Advanced .....                                | 14          |
+|   | 7.18 Reference file set Alpha_Interleaved .....                                           | 15          |
+|   | 7.19 Reference file set Hard_Tile_Boundaries .....                                        | 15          |
+|   | 7.20 Reference file set Index_Table_Use.....                                              | 17          |
+|   | 7.21 Reference file set Levels .....                                                      | 17          |
+|   | 7.22 Reference file set Long_Word_Flag .....                                              | 18          |
+|   | 7.23 Reference file set Windowing .....                                                   | 18          |
+|   | 7.24 Reference file set Chroma_Centering .....                                            | 19          |
+|   | 7.25 Reference file set Tag_Based_Container .....                                         | 19          |
+|   | 7.26 Reference file set Tile_Sizes .....                                                  | 20          |
+|   | 7.27 Reference file set Red-Blue-Not-Swapped .....                                        | 20          |
+|   | 7.28 Reference file set Use-DCLP-QP-Flag .....                                            | 21          |
+|   | 7.29 Reference file set Trim-Flexbits.....                                                | 21          |
+|   | 7.30 Reference file set Spatial_XFRM.....                                                 | 21          |
+|   | 7.31 Reference file set BoxBased-Format.....                                              | 22          |
+
+# Foreword
+
+This Recommendation | International Standard specifies tests designed to verify whether codestreams, files, encoders and decoders meet the normative requirements specified in Rec. ITU-T T.832 | ISO/IEC 29199-2 (*Information technology – JPEG XR image coding system – Image coding specification*).
+
+A set of data for use in such tests is provided as an electronic attachment to this Recommendation | International Standard and is considered an integral part thereof.
+
+# Introduction
+
+This Recommendation | International Standard has been developed by ITU-T and ISO/IEC in a collaborative team that is referred to as the Joint Photographic Experts Group (JPEG). It is published as a technically-aligned twin text by both organizations (ITU-T and ISO/IEC).
+
+This Recommendation | International Standard specifies a set of tests designed to verify whether codestreams, files, encoders and decoders meet the normative requirements specified in Rec. ITU-T T.832 | ISO/IEC 29199-2 (*Information technology – JPEG XR image coding system – Image coding specification*).
+
+- A codestream (or file) can be claimed to conform to Rec. ITU-T T.832 | ISO/IEC 29199-2 if it meets the normative requirements for such codestreams (or file) specified in Rec. ITU-T T.832 | ISO/IEC 29199-2.
+- An encoder can be claimed to have codestream (or file format) conformance to Rec. ITU-T T.832 | ISO/IEC 29199-2 if the codestreams (or files) that it generates are conforming codestreams (or files).
+- A decoder can be claimed to conform to a specified subset of Rec. ITU-T T.832 | ISO/IEC 29199-2 capabilities (such as a combination of "profile" and "level" capabilities) if it can properly decode all codestreams (or files) obeying the constraints specified in Rec. ITU-T T.832 | ISO/IEC 29199-2 for the specified subset of capabilities.
+
+The tests specified in this Recommendation | International Standard provide methods for (non-exhaustive) testing of whether encoders and decoders meet these requirements.
+
+Characteristics of codestreams, files and decoders are specified in Rec. ITU-T T.832 | ISO/IEC 29199-2. The characteristics of a codestream (or file) indicate the subset of that standard that is exploited within the codestream (or file). Examples are the selected values of the image size and number of associated colour components. Decoder characteristics specify the properties and capabilities of the applied decoding process. The capabilities of a decoder specify which codestreams (or files) the decoder can decode by specifying the subset of Rec. ITU-T T.832 | ISO/IEC 29199-2 syntax features and values that may be exploited in the codestreams (or files) that it will decode. A codestream (or file) can be decoded by a conforming decoder if it is a conforming codestream (or file) and the characteristics of the codestream (or file) are within the subset of the standard that is specified by the decoder capabilities.
+
+Procedures are specified in this Recommendation | International Standard for testing the conformance of codestreams (or files) and decoders to the requirements specified in Rec. ITU-T T.832 | ISO/IEC 29199-2. Given the set of characteristics claimed, the requirements that shall be met are fully determined by Rec. ITU-T T.832 | ISO/IEC 29199-2. This Recommendation | International Standard summarizes these requirements, cross references them to characteristics, and specifies how conformance to them can be tested. Particular tests to verify codestream and decoder conformance are specified.
+
+A set of data for use in such tests is provided as an electronic attachment to this Recommendation | International Standard and is considered an integral part thereof. When a decoder under test does not satisfy the requirements of the specified tests when operating on the provided data set, the decoder is indicated not to conform to Rec. ITU-T T.832 | ISO/IEC 29199-2.
+
+The specified testing of codestreams (or files) produced by encoders employs the reference software decoder specified in Rec. ITU-T T.835 | ISO/IEC 29199-5 (with source code available in electronic format). When a codestream (or file) cannot be decoded by the reference software decoder without generating non-conformance warning messages, the codestream (or file) is indicated not to conform to Rec. ITU-T T.832 | ISO/IEC 29199-2. When an encoder produces any such codestreams (or files) that cannot be decoded without warnings by the reference software decoder, the encoder is indicated not to conform to Rec. ITU-T T.832 | ISO/IEC 29199-2.
+
+###### Information technology – JPEG XR image coding system – Conformance testing
+
+# 1 Scope
+
+This Recommendation | International Standard specifies a set of tests designed to verify whether codestreams, files, encoders and decoders meet the normative requirements specified in Rec. ITU-T T.832 | ISO/IEC 29199-2 (*Information technology – JPEG XR image coding system – Image coding specification*).
+
+# 2 Normative references
+
+The following Recommendations and International Standards contain provisions which, through reference in this text, constitute provisions of this Recommendation | International Standard. At the time of publication, the editions indicated were valid. All Recommendations and Standards are subject to revision, and parties to agreements based on this Recommendation | International Standard are encouraged to investigate the possibility of applying the most recent edition of the Recommendations and Standards listed below. Members of IEC and ISO maintain registers of currently valid International Standards. The Telecommunication Standardization Bureau of the ITU maintains a list of currently valid ITU-T Recommendations.
+
+## 2.1 Identical Recommendations | International Standards
+
+- Recommendation ITU-T T.801 (2002) | ISO/IEC 15444-2:2004, *Information technology – JPEG 2000 image coding system: Extensions* and its subsequent amendments and corrigenda, namely: Cor. 3 (2005), Cor. 4 (2006), Amd. 2 (2005), Amd. 4 (2012) and Amd. 3 (2013).
+
+## 2.2 Paired Recommendations | International Standards equivalent in technical content
+
+- Recommendation ITU-T T.832 (2012) | ISO/IEC 29199-2:2012, *Information technology – JPEG XR image coding system – Image coding specification*.
+- Recommendation ITU-T T.835 (2012) | ISO/IEC 29199-5:2010, *Information technology – JPEG XR image coding system – Reference software*.
+
+## 2.3 Additional references
+
+None.
+
+# 3 Definitions
+
+For the purposes of this Recommendation | International Standard, the terms, definitions, abbreviations and symbols specified in Rec. ITU-T T.832 | ISO/IEC 29199-2 (particularly in its clause 3) apply. The following terms are further defined or clarified for purposes herein as follows.
+
+**3.1 codestream:** A sequence of bits contained in a sequence of bytes that conforms to the *codestream* requirements specified by Rec. ITU-T T.832 | ISO/IEC 29199-2 or is to be tested to determine whether it conforms to the *codestream* requirements specified by Rec. ITU-T T.832 | ISO/IEC 29199-2.
+
+**3.2 decoder:** An embodiment of the decoding process specified by Rec. ITU-T T.832 | ISO/IEC 29199-2 or a process embodiment that is to be tested to determine whether it conforms to the decoding process specified by Rec. ITU-T T.832 | ISO/IEC 29199-2.
+
+NOTE – The *decoder* does not include the display process, which is outside the scope of this Recommendation | International Standard.
+
+**3.3 encoder:** A process that produces *codestreams* or *files* that conform to Rec. ITU-T T.832 | ISO/IEC 29199-2 or are to be tested to determine whether these *codestreams* or *files* conform to Rec. ITU-T T.832 | ISO/IEC 29199-2.
+
+**3.4 file** (when used in reference to Rec. ITU-T T.832 | ISO/IEC 29199-2 Annex A): A finite-length sequence of bytes produced by an *encoder* that conforms to Rec. ITU-T T.832 | ISO/IEC 29199-2 Annex A or is to be tested to determine whether it conforms to Rec. ITU-T T.832 | ISO/IEC 29199-2 Annex A.
+
+**3.5 reference output:** The output of the *reference software decoder*.
+
+**3.6 reference software decoder:** The software *decoder* contained in Rec. ITU-T T.835 | ISO/IEC 29199-5.
+
+# **4 Abbreviations**
+
+For the purposes of this Recommendation | International Standard, the relevant abbreviations are specified in clause 4 of Rec. ITU-T T.832 | ISO/IEC 29199-2.
+
+# **5 Conventions**
+
+For the purposes of this Recommendation | International Standard, the relevant conventions are specified in clause 5 of Rec. ITU-T T.832 | ISO/IEC 29199-2.
+
+# **6 Conformance testing specification**
+
+## **6.1 General**
+
+The following clauses specify normative tests designed to verify whether codestreams, files, encoders and decoders meet the normative requirements specified in Rec. ITU-T T.832 | ISO/IEC 29199-2, as follows:
+
+- A codestream (or file) can be claimed to conform to Rec. ITU-T T.832 | ISO/IEC 29199-2 if it meets the normative requirements for such codestreams (or file) specified in Rec. ITU-T T.832 | ISO/IEC 29199-2.
+- An encoder can be claimed to have codestream (or file format) conformance to Rec. ITU-T T.832 | ISO/IEC 29199-2 if the codestreams (or files) that it generates are conforming codestreams (or files).
+- A decoder can be claimed to conform to a specified subset of Rec. ITU-T T.832 | ISO/IEC 29199-2 capabilities (such as a combination of "profile" and "level" capabilities) if it can properly decode all codestreams (or files) obeying the constraints specified in Rec. ITU-T T.832 | ISO/IEC 29199-2 for the specified subset of capabilities.
+
+The tests specified in this Specification provide methods for (non-exhaustive) testing of whether encoders and decoders meet these requirements.
+
+Characteristics of codestreams, files and decoders are specified in Rec. ITU-T T.832 | ISO/IEC 29199-2. The characteristics of a codestream (or file) indicate the subset of that standard that is exploited within the codestream (or file). Examples are the selected values of the image size and number of associated colour components. Decoder characteristics specify the properties and capabilities of the applied decoding process. The capabilities of a decoder specify which codestreams (or files) the decoder can decode by specifying the subset of Rec. ITU-T T.832 | ISO/IEC 29199-2 syntax features and values that may be exploited in the codestreams (or files) that it will decode. A codestream (or file) can be decoded by a conforming decoder if it is a conforming codestream (or file) and the characteristics of the codestream (or file) are within the subset of the standard that is specified by the decoder capabilities.
+
+Procedures are specified in this Specification for testing the conformance of codestreams (or files) and decoders to the requirements specified in Rec. ITU-T T.832 | ISO/IEC 29199-2. Given the set of characteristics claimed, the requirements that shall be met are fully determined by Rec. ITU-T T.832 | ISO/IEC 29199-2. This Recommendation | International Standard summarizes these requirements, cross references them to codestream (or file) characteristics, and specifies how conformance to the requirements can be tested. Particular tests to verify codestream and decoder conformance are specified.
+
+A set of data for use in such tests is provided as an electronic attachment to this Recommendation | International Standard and is considered an integral part thereof. When a decoder under test does not satisfy the requirements of the specified tests when operating on the provided data set, the decoder is indicated not to conform to Rec. ITU-T T.832 | ISO/IEC 29199-2.
+
+The specified testing of codestreams (or files) produced by encoders employs the reference software decoder specified in Rec. ITU-T T.835 | ISO/IEC 29199-5 (with source code available in electronic format). When a codestream (or file) cannot be decoded by the reference software decoder without generating non-conformance warning messages, the codestream (or file) is indicated not to conform to Rec. ITU-T T.832 | ISO/IEC 29199-2. When an encoder produces any such codestreams (or files) that cannot be decoded without warnings by the reference software decoder, the encoder is indicated not to conform to Rec. ITU-T T.832 | ISO/IEC 29199-2.
+
+## 6.2 Procedure to test codestreams (or files)
+
+A codestream (or file) that claims conformance with Rec. ITU-T T.832 | ISO/IEC 29199-2 shall pass the following normative test.
+
+The codestream (or file) shall be decoded by processing it with the reference software decoder. When processed by the reference software decoder, the codestream (or file) shall not cause any error or non-conformance messages to be reported by the reference software decoder. The output of the reference software decoder shall be considered the reference output.
+
+NOTE 1 – This test should not be applied to codestreams (or files) that are known to contain errors introduced by transmission, as such errors are highly likely to result in codestreams (or files) that lack conformance to Rec. ITU-T T.832 | ISO/IEC 29199-2.
+
+Successfully passing the reference software decoder test provides only a preliminary indication that the codestream (or file) under test is in conformance to Rec. ITU-T T.832 | ISO/IEC 29199-2, as not all conformance requirements of Rec. ITU-T T.832 | ISO/IEC 29199-2 may be tested by the reference software decoder.
+
+Additional tests may be necessary to more thoroughly check that the codestream (or file) properly meets all the requirements specified in Rec. ITU-T T.832 | ISO/IEC 29199-2. These complementary tests may be performed using other codestream (or file) verifiers that perform more complete tests than those implemented by the reference software decoder.
+
+NOTE 2 – Indications of codestream (or file) non-conformance obtained in such tests should be investigated to verify the exact characteristics of the codestream (or file) that resulted in the indication and the relationship of these characteristics to the requirements expressed in Rec. ITU-T T.832 | ISO/IEC 29199-2 for conformance to that Specification.
+
+To check correctness of a codestream (or file), it is necessary to parse the entire codestream (or file) and to extract all the syntax elements and other values derived from those syntactic elements and used by the decoding process specified in Rec. ITU-T T.832 | ISO/IEC 29199-2.
+
+Some verifiers may not necessarily need to perform all stages of the decoding process specified in Rec. ITU-T T.832 | ISO/IEC 29199-2 in order to verify aspects of codestream (or file) correctness. Many tests can be performed on syntax elements in a state prior to their use in some processing stages.
+
+## 6.3 Procedure to test encoders
+
+An encoder can be claimed to have codestream (or file format) conformance to Rec. ITU-T T.832 | ISO/IEC 29199-2 if the codestreams (or files) that it generates are conforming codestreams (or files). To test an encoder for conformance to Rec. ITU-T T.832 | ISO/IEC 29199-2, the encoder should be operated in such a manner as to maximally exercise its usage of the syntax features of Rec. ITU-T T.832 | ISO/IEC 29199-2, and sample codestreams (or files) produced from the encoder shall be checked for conformance to Rec. ITU-T T.832 | ISO/IEC 29199-2 as specified in clause 6.2. If the encoder produces codestreams (or files) that do not conform to Rec. ITU-T T.832 | ISO/IEC 29199-2 under such sample testing operation, the encoder is indicated not to conform to Rec. ITU-T T.832 | ISO/IEC 29199-2.
+
+## 6.4 Procedure to test decoders
+
+A decoder can be claimed to conform to a specified subset of Rec. ITU-T T.832 | ISO/IEC 29199-2 capabilities (such as a combination of "profile" and "level" capabilities) if it can properly decode all codestreams (or files) obeying the constraints specified in Rec. ITU-T T.832 | ISO/IEC 29199-2 for the specified subset of capabilities. To test a decoder for conformance to a specified subset of Rec. ITU-T T.832 | ISO/IEC 29199-2 capabilities, the set of reference encoded files (or, in the case of codestream-level testing, the set of codestreams extracted from those files) specified below in clause 7 that are within the specified subset of Rec. ITU-T T.832 | ISO/IEC 29199-2 capabilities shall be processed by the decoder under test and by the reference software decoder. The decoder under test shall output decoded images, and the output decoded images produced by the decoder under test shall be checked for correspondence with the output of the reference software decoder. The output decoded images produced by the two decoding processes shall match exactly. When upsampling is invoked in the output formatting process specified in clause 9.10 of Rec. ITU-T T.832 | ISO/IEC 29199-2, the upsampling process performed for purposes of conformance testing of the output of the decoder under test shall be the nominal upsampling process specified in clause 9.10.3.1 or 9.10.3.2 of Rec. ITU-T T.832 | ISO/IEC 29199-2, as applicable. However, the actual manner of performing upsampling by a decoder for purposes other than conformance testing is outside the scope of conformance requirements to Rec. ITU-T T.832 | ISO/IEC 29199-2, as noted in clauses 8.4.6 and 8.4.9 of Rec. ITU-T T.832 | ISO/IEC 29199-2.
+
+# 7 Reference data set
+
+## 7.1 General
+
+A set of data for use in decoder conformance tests is provided as an electronic attachment to this Recommendation | International Standard and is considered an integral part thereof. This set of data consists of a number of files encoded according to Rec. ITU-T T.832 | ISO/IEC 29199-2 Annex A. For purposes of codestream-only testing, the testing shall be performed by extracting the codestreams embedded within these files and performing the testing using these codestreams.
+
+This set of files and the codestreams they contain are not intended to represent all combinations of syntax elements that are allowed in Rec. ITU-T T.832 | ISO/IEC 29199-2. Rather, the set of files (and the codestreams they contain) was developed with the intention of testing key selected aspects of the parsing and decoding processes that are required by the various syntax elements. Selected characteristics of the files in each category are described in the corresponding clauses of this Recommendation | International Standard.
+
+## 7.2 Reference file set BasicAndOverlap\_1x1Tile
+
+This collection of 18 .jxr files has the following syntax element characteristics:
+
+- The FREQUENCY\_MODE\_CODESTREAM\_FLAG syntax element is set to FALSE (spatial mode) or TRUE (frequency mode).
+- The OVERLAP\_MODE is varied between the values 0, 1 and 2.
+- The INTERNAL\_CLR\_FMT is set to YUV444 or YONLY.
+- The QP (for all colour channels and all bands) is set to 1 or 10.
+
+For all files in the BasicAndOverlap\_1x1Tile set, the syntax elements NUM\_HOR\_TILES\_MINUS1 and NUM\_VER\_TILES\_MINUS1 are both set to 0, resulting in each image being structured as a single tile.
+
+The following files are included in the BasicAndOverlap\_1x1Tile file set:
+
+- Seattle\_Spat\_Ov0\_1x1\_YONLY\_QP10.jxr
+- Seattle\_Spat\_Ov0\_1x1\_YUV444\_QP1.jxr
+- Seattle\_Spat\_Ov0\_1x1\_YUV444\_QP10.jxr
+- Seattle\_Spat\_Ov1\_1x1\_YONLY\_QP10.jxr
+- Seattle\_Spat\_Ov1\_1x1\_YUV444\_QP1.jxr
+- Seattle\_Spat\_Ov1\_1x1\_YUV444\_QP10.jxr
+- Seattle\_Spat\_Ov2\_1x1\_YONLY\_QP10.jxr
+- Seattle\_Spat\_Ov2\_1x1\_YUV444\_QP1.jxr
+- Seattle\_Spat\_Ov2\_1x1\_YUV444\_QP10.jxr
+- Seattle\_Freq\_Ov0\_1x1\_YONLY\_QP10.jxr
+- Seattle\_Freq\_Ov0\_1x1\_YUV444\_QP1.jxr
+- Seattle\_Freq\_Ov0\_1x1\_YUV444\_QP10.jxr
+- Seattle\_Freq\_Ov1\_1x1\_YONLY\_QP10.jxr
+- Seattle\_Freq\_Ov1\_1x1\_YUV444\_QP1.jxr
+- Seattle\_Freq\_Ov1\_1x1\_YUV444\_QP10.jxr
+- Seattle\_Freq\_Ov2\_1x1\_YONLY\_QP10.jxr
+- Seattle\_Freq\_Ov2\_1x1\_YUV444\_QP1.jxr
+- Seattle\_Freq\_Ov2\_1x1\_YUV444\_QP10.jxr
+
+These files can be found in the directory BasicAndOverlap\_1x1Tile.
+
+## 7.3 Reference file set BasicAndOverlap\_4x4Tile
+
+This collection of 42 .jxr files has the same type of syntax element characteristics as in the BasicAndOverlap\_1x1Tile file set (clause 7.2), except that in the files in BasicAndOverlap\_4x4Tile, the syntax elements NUM\_HOR\_TILES\_MINUS1 and NUM\_VER\_TILES\_MINUS1 are both set to 3, resulting in each image being structured as a 4×4 grid of tiles. The remaining note syntax characteristics are repeated here:
+
+- The FREQUENCY\_MODE\_CODESTREAM\_FLAG syntax element is set to FALSE (spatial mode) or TRUE (frequency mode).
+- The OVERLAP\_MODE is varied between the values 0, 1 and 2.
+- The INTERNAL\_CLR\_FMT is set to YUV444, YUV422, YUV420 or YONLY.
+- The QP (for all colour channels and all bands) is set to 1 or 10.
+
+The following files are included in the BasicAndOverlap\_4x4Tile file set:
+
+- Seattle\_Spat\_Ov0\_4x4\_YONLY\_QP10.jxr
+- Seattle\_Spat\_Ov0\_4x4\_YUV420\_QP1.jxr
+- Seattle\_Spat\_Ov0\_4x4\_YUV420\_QP10.jxr
+- Seattle\_Spat\_Ov0\_4x4\_YUV422\_QP1.jxr
+- Seattle\_Spat\_Ov0\_4x4\_YUV422\_QP10.jxr
+- Seattle\_Spat\_Ov0\_4x4\_YUV444\_QP1.jxr
+- Seattle\_Spat\_Ov0\_4x4\_YUV444\_QP10.jxr
+- Seattle\_Spat\_Ov1\_4x4\_YONLY\_QP10.jxr
+- Seattle\_Spat\_Ov1\_4x4\_YUV420\_QP1.jxr
+- Seattle\_Spat\_Ov1\_4x4\_YUV420\_QP10.jxr
+- Seattle\_Spat\_Ov1\_4x4\_YUV422\_QP1.jxr
+- Seattle\_Spat\_Ov1\_4x4\_YUV422\_QP10.jxr
+- Seattle\_Spat\_Ov1\_4x4\_YUV444\_QP1.jxr
+- Seattle\_Spat\_Ov1\_4x4\_YUV444\_QP10.jxr
+- Seattle\_Spat\_Ov2\_4x4\_YONLY\_QP10.jxr
+- Seattle\_Spat\_Ov2\_4x4\_YUV420\_QP1.jxr
+- Seattle\_Spat\_Ov2\_4x4\_YUV420\_QP10.jxr
+- Seattle\_Spat\_Ov2\_4x4\_YUV422\_QP1.jxr
+- Seattle\_Spat\_Ov2\_4x4\_YUV422\_QP10.jxr
+- Seattle\_Spat\_Ov2\_4x4\_YUV444\_QP1.jxr
+- Seattle\_Spat\_Ov2\_4x4\_YUV444\_QP10.jxr
+- Seattle\_Freq\_Ov0\_4x4\_YONLY\_QP10.jxr
+- Seattle\_Freq\_Ov0\_4x4\_YUV420\_QP1.jxr
+- Seattle\_Freq\_Ov0\_4x4\_YUV420\_QP10.jxr
+- Seattle\_Freq\_Ov0\_4x4\_YUV422\_QP1.jxr
+- Seattle\_Freq\_Ov0\_4x4\_YUV422\_QP10.jxr
+- Seattle\_Freq\_Ov0\_4x4\_YUV444\_QP1.jxr
+- Seattle\_Freq\_Ov0\_4x4\_YUV444\_QP10.jxr
+- Seattle\_Freq\_Ov1\_4x4\_YONLY\_QP10.jxr
+- Seattle\_Freq\_Ov1\_4x4\_YUV420\_QP1.jxr
+- Seattle\_Freq\_Ov1\_4x4\_YUV420\_QP10.jxr
+- Seattle\_Freq\_Ov1\_4x4\_YUV422\_QP1.jxr
+- Seattle\_Freq\_Ov1\_4x4\_YUV422\_QP10.jxr
+- Seattle\_Freq\_Ov1\_4x4\_YUV444\_QP1.jxr
+- Seattle\_Freq\_Ov1\_4x4\_YUV444\_QP10.jxr
+- Seattle\_Freq\_Ov2\_4x4\_YONLY\_QP10.jxr
+
+- Seattle\_Freq\_Ov2\_4x4\_YUV420\_QP1.jxr
+- Seattle\_Freq\_Ov2\_4x4\_YUV420\_QP10.jxr
+- Seattle\_Freq\_Ov2\_4x4\_YUV422\_QP1.jxr
+- Seattle\_Freq\_Ov2\_4x4\_YUV422\_QP10.jxr
+- Seattle\_Freq\_Ov2\_4x4\_YUV444\_QP1.jxr
+- Seattle\_Freq\_Ov2\_4x4\_YUV444\_QP10.jxr
+
+These files can be found in the directory BasicAndOverlap\_4x4Tile.
+
+## 7.4 Reference file set BasicAndOverlap\_2x2Tile
+
+This collection of five .jxr files has the same type of syntax element characteristics as in the BasicAndOverlap\_1x1Tile file set (clause 7.2) and BasicAndOverlap\_4x4Tile file set (clause 7.3), except that in the files in BasicAndOverlap\_2x2Tile, the syntax elements NUM\_HOR\_TILES\_MINUS1 and NUM\_VER\_TILES\_MINUS1 are both set to 1, resulting in each image being structured as a 2×2 grid of tiles. The remaining note syntax characteristics are repeated here:
+
+- The FREQUENCY\_MODE\_CODESTREAM\_FLAG syntax element is set to TRUE (frequency mode).
+- The OVERLAP\_MODE is varied between the values 1 and 2.
+- The INTERNAL\_CLR\_FMT is set to YUV422 or YUV420.
+- The QP (for all colour channels and all bands) is set to 10.
+
+The following files are included in the BasicAndOverlap\_2x2Tile file set:
+
+- Seattle\_Freq\_Ov1\_2x2\_YUV422\_QP10.jxr
+- Seattle\_Freq\_Ov2\_2x2\_YUV422\_QP10.jxr
+- Small\_Freq\_Ov1\_2x2\_YUV422\_QP10.jxr
+- Small\_Freq\_Ov2\_2x2\_YUV420\_QP10.jxr
+- Small\_Freq\_Ov2\_2x2\_YUV422\_QP10.jxr
+
+These files can be found in the directory BasicAndOverlap\_2x2Tile.
+
+## 7.5 Reference file set BandsPresent\_1x1Tile
+
+This collection of 12 .jxr files has the following syntax element characteristics:
+
+- The FREQUENCY\_MODE\_CODESTREAM\_FLAG syntax element is set to FALSE (spatial mode) or TRUE (frequency mode).
+- The INTERNAL\_CLR\_FMT syntax element is set to YUV444 or YONLY.
+- The BANDS\_PRESENT syntax element is set to the value DONLY, NOHIGHPASS or NOFLEXBITS.
+
+For all files in the BandsPresent\_1x1Tile set, the syntax elements NUM\_HOR\_TILES\_MINUS1 and NUM\_VER\_TILES\_MINUS1 are both set to 0, resulting in each image being structured as a single tile. The OVERLAP\_MODE syntax element is set to 0 for all of these files.
+
+The following files are included in the BandsPresent\_1x1Tile file set:
+
+- Seattle\_Spat\_Ov0\_1x1\_YONLY\_SBDC.jxr
+- Seattle\_Spat\_Ov0\_1x1\_YUV444\_SBDC.jxr
+- Seattle\_Spat\_Ov0\_1x1\_YONLY\_SBNOHP.jxr
+- Seattle\_Spat\_Ov0\_1x1\_YUV444\_SBNOHP.jxr
+- Seattle\_Spat\_Ov0\_1x1\_YONLY\_SBNOFlex.jxr
+- Seattle\_Spat\_Ov0\_1x1\_YUV444\_SBNOFlex.jxr
+- Seattle\_Freq\_Ov0\_1x1\_YONLY\_SBDC.jxr
+- Seattle\_Freq\_Ov0\_1x1\_YUV444\_SBDC.jxr
+- Seattle\_Freq\_Ov0\_1x1\_YONLY\_SBNOHP.jxr
+- Seattle\_Freq\_Ov0\_1x1\_YUV444\_SBNOHP.jxr
+- Seattle\_Freq\_Ov0\_1x1\_YONLY\_SBNOFlex.jxr
+- Seattle\_Freq\_Ov0\_1x1\_YUV444\_SBNOFlex.jxr
+
+- Seattle\_Freq\_Ov0\_1x1\_YUV444\_SBNOFlex.jxr
+
+These files can be found in the directory BandsPresent\_1x1Tile.
+
+## 7.6 Reference file set BandsPresent\_4x4Tile
+
+This collection of 12 .jxr files has the same syntax element characteristics as the BandsPresent\_1x1Tile file set (clause 7.5), except that in BandsPresent\_4x4Tile, the syntax elements NUM\_HOR\_TILES\_MINUS1 and NUM\_VER\_TILES\_MINUS1 are both set to 3, resulting in each image being structured as a 4×4 grid of tiles. The remaining noted syntax characteristics are repeated here:
+
+- The FREQUENCY\_MODE\_CODESTREAM\_FLAG syntax element is set to FALSE (spatial mode) or TRUE (frequency mode).
+- The INTERNAL\_CLR\_FMT syntax element is set to YUV444 or YONLY.
+- The BANDS\_PRESENT syntax element is set to the value DCONLY, to NOHIGHPASS or to NOFLEXBITS.
+
+As in clause 7.5, the OVERLAP\_MODE syntax element is set to 0.
+
+The following codestreams are included in the BandsPresent\_4x4Tile file set:
+
+- Seattle\_Spat\_Ov0\_4x4\_YONLY\_SBDC.jxr
+- Seattle\_Spat\_Ov0\_4x4\_YUV444\_SBDC.jxr
+- Seattle\_Spat\_Ov0\_4x4\_YONLY\_SBNOHP.jxr
+- Seattle\_Spat\_Ov0\_4x4\_YUV444\_SBNOHP.jxr
+- Seattle\_Spat\_Ov0\_4x4\_YONLY\_SBNOFlex.jxr
+- Seattle\_Spat\_Ov0\_4x4\_YUV444\_SBNOFlex.jxr
+- Seattle\_Freq\_Ov0\_4x4\_YONLY\_SBDC.jxr
+- Seattle\_Freq\_Ov0\_4x4\_YUV444\_SBDC.jxr
+- Seattle\_Freq\_Ov0\_4x4\_YONLY\_SBNOHP.jxr
+- Seattle\_Freq\_Ov0\_4x4\_YUV444\_SBNOHP.jxr
+- Seattle\_Freq\_Ov0\_4x4\_YONLY\_SBNOFlex.jxr
+- Seattle\_Freq\_Ov0\_4x4\_YUV444\_SBNOFlex.jxr
+
+These files can be found in the directory BandsPresent\_4x4Tile.
+
+## 7.7 Reference file set Varied\_QP
+
+This collection of 12 .jxr files has the following syntax element characteristics:
+
+- The value of CH\_MODE (for DC, LP and HP) is set to 0, 1 or 2.
+- The quantizers for low pass and high pass are set to be the same as DC or different from DC.
+- The QP values are varied.
+
+For all files in the Varied\_QP set, the syntax elements NUM\_HOR\_TILES\_MINUS1 and NUM\_VER\_TILES\_MINUS1 are both set to 0, resulting in each image being structured as a single tile. The OVERLAP\_MODE syntax element is set to 1 and the FREQUENCY\_MODE\_CODESTREAM\_FLAG syntax element is set to FALSE (spatial mode) and the INTERNAL\_CLR\_FMT syntax element is set to YUV444.
+
+The following files are included in the Varied\_QP file set:
+
+- Seattle\_QP\_1\_BandInd\_ChanInd.jxr
+- Seattle\_QP\_1\_BandInd\_ChanSep.jxr
+- Seattle\_QP\_1\_BandInd\_ChanUnif.jxr
+- Seattle\_QP\_1\_BandUnif\_ChanInd.jxr
+- Seattle\_QP\_1\_BandUnif\_ChanSep.jxr
+- Seattle\_QP\_1\_BandUnif\_ChanUnif.jxr
+- Seattle\_QP\_5\_BandInd\_ChanInd.jxr
+- Seattle\_QP\_5\_BandInd\_ChanSep.jxr
+
+- Seattle\_QP\_5\_BandInd\_Chunif.jxr
+- Seattle\_QP\_5\_BandUnif\_Chunif.jxr
+- Seattle\_QP\_5\_BandUnif\_Chunif.jxr
+- Seattle\_QP\_5\_BandUnif\_Chunif.jxr
+
+These files can be found in the directory Varied\_QP.
+
+## 7.8 Reference file set Varied\_Internal\_Color\_Format
+
+This collection of eight .jxr files has the following syntax element characteristics:
+
+- The OVERLAP\_MODE syntax element is varied between the values 1 and 2.
+- The INTERNAL\_CLR\_FMT syntax element is set to YUV420 or YUV422.
+- The QP values are varied.
+
+For all files in the Varied-Internal-Color-Format set, the syntax elements NUM\_HOR\_TILES\_MINUS1 and NUM\_VER\_TILES\_MINUS1 are both set to 0, resulting in each image being structured as a single tile. The FREQUENCY\_MODE\_CODESTREAM\_FLAG syntax element is set to FALSE (spatial mode).
+
+The following files are included in the Varied\_Internal\_Color\_Format file set:
+
+- Seattle\_QP\_1\_YUV\_420\_Ov1.jxr
+- Seattle\_QP\_1\_YUV\_420\_Ov2.jxr
+- Seattle\_QP\_1\_YUV\_422\_Ov1.jxr
+- Seattle\_QP\_1\_YUV\_422\_Ov2.jxr
+- Seattle\_QP\_5\_YUV\_420\_Ov1.jxr
+- Seattle\_QP\_5\_YUV\_420\_Ov2.jxr
+- Seattle\_QP\_5\_YUV\_422\_Ov1.jxr
+- Seattle\_QP\_5\_YUV\_422\_Ov2.jxr
+
+These files can be found in the directory Varied\_Internal\_Color\_Format.
+
+## 7.9 Reference file set Output\_Bitdepth\_16
+
+This collection of 18 .jxr files has the following syntax element characteristics:
+
+- The FREQUENCY\_MODE\_CODESTREAM\_FLAG syntax element is varied between FALSE (spatial mode) and TRUE (frequency mode).
+- The OVERLAP\_MODE syntax element is varied between the values 0, 1 and 2.
+- The Tile structure is varied between 1×1, 1×6, 6×1 and 6×6.
+- The INTERNAL\_CLR\_FMT syntax element is varied between YUV444 and YONLY.
+- The QPs are varied to exercise the corner cases of the QuantMap( ) function.
+- The SCALED\_FLAG syntax element is varied between 0 and 1.
+
+The OUTPUT\_BITDEPTH syntax element is set to BD16.
+
+The following files are included in the Output\_Bitdepth\_16 file set:
+
+- CarHandle\_Spat\_Ov0\_1x1\_YONLY.jxr
+- CarHandle\_Spat\_Ov0\_1x1\_YUV444.jxr
+- CarHandle\_Spat\_Ov0\_6x6\_YUV444.jxr
+- CarHandle\_Spat\_Ov0\_1x6\_YONLY.jxr
+- CarHandle\_Freq\_Ov0\_1x1\_YUV444.jxr
+- CarHandle\_Freq\_Ov0\_6x1\_YUV444.jxr
+- CarHandle\_Freq\_Ov0\_6x6\_YONLY.jxr
+- CarHandle\_Spat\_Ov1\_1x1\_YUV444.jxr
+- CarHandle\_Spat\_Ov1\_1x1\_YONLY.jxr
+- CarHandle\_Spat\_Ov1\_1x6\_YONLY.jxr
+
+- CarHandle\_Freq\_Ov1\_1x1\_YUV444.jxr
+- CarHandle\_Freq\_Ov1\_6x6\_YONLY.jxr
+- CarHandle\_Freq\_Ov1\_6x1\_YUV444.jxr
+- CarHandle\_Spat\_Ov2\_1x1\_YUV444.jxr
+- CarHandle\_Spat\_Ov2\_6x6\_YUV444.jxr
+- CarHandle\_Spat\_Ov2\_1x6\_YONLY.jxr
+- CarHandle\_Freq\_Ov2\_1x1\_YONLY.jxr
+- CarHandle\_Freq\_Ov2\_6x1\_YONLY.jxr
+
+These files can be found in the directory Output\_Bitdepth\_16.
+
+## 7.10 Reference file set Special\_QP
+
+This collection of 21 .jxr files includes QP variations that test corner cases of the QuantMap( ) function:
+
+- For syntax element SCALED\_FLAG == 0, there are streams that test  $QP < 32$ ,  $32 \leq QP < 48$  and  $QP \geq 48$ .
+- For syntax element SCALED\_FLAG == 1, there are streams that test  $QP < 16$  and  $QP \geq 16$ .
+- The special case of  $QP == 0$ .
+
+The following files are included in the Special\_QP file set:
+
+- Seattle\_QPIndex0.jxr
+- Seattle\_ScaleFlag0\_QP31.jxr
+- Seattle\_ScaleFlag0\_QP32.jxr
+- Seattle\_ScaleFlag0\_QP47.jxr
+- Seattle\_ScaleFlag0\_QP48.jxr
+- Seattle\_ScaleFlag1\_QP15.jxr
+- Seattle\_ScaleFlag1\_QP16.jxr
+- Seattle\_Ov0\_QPIndex0.jxr
+- Seattle\_Ov0\_ScaleFlag0\_QP31.jxr
+- Seattle\_Ov0\_ScaleFlag0\_QP32.jxr
+- Seattle\_Ov0\_ScaleFlag0\_QP47.jxr
+- Seattle\_Ov0\_ScaleFlag0\_QP48.jxr
+- Seattle\_Ov0\_ScaleFlag1\_QP15.jxr
+- Seattle\_Ov0\_ScaleFlag1\_QP16.jxr
+- Seattle\_Ov1\_QPIndex0.jxr
+- Seattle\_Ov1\_ScaleFlag0\_QP31.jxr
+- Seattle\_Ov1\_ScaleFlag0\_QP32.jxr
+- Seattle\_Ov1\_ScaleFlag0\_QP47.jxr
+- Seattle\_Ov1\_ScaleFlag0\_QP48.jxr
+- Seattle\_Ov1\_ScaleFlag1\_QP15.jxr
+- Seattle\_Ov1\_ScaleFlag1\_QP16.jxr
+
+These files can be found in the directory Special\_QP.
+
+## 7.11 Reference file set Flags\_And\_Tiles
+
+This collection of nine .jxr files has the following syntax element characteristics:
+
+- A syntax element INDEX\_TABLE\_PRESENT\_FLAG is set to TRUE, despite having a 1×1 tile pattern and FREQUENCY\_MODE\_CODESTREAM\_FLAG syntax element set to FALSE (spatial mode).
+- A syntax element SHORT\_HEADER\_FLAG is set to FALSE.
+- Various combinations of tile patterns: 1×2, 2×1, 1×4, 4×1 and 2×2 are used.
+
+The following files are included in the Flags\_And\_Tiles file set:
+
+- Seattle\_1x1\_IndexTable1.jxr
+- Seattle\_4x4\_ShrHdr0.jxr
+- Seattle\_QP1\_1x2Tiles.jxr
+- Seattle\_QP1\_1x4Tiles.jxr
+- Seattle\_QP1\_2x1Tiles.jxr
+- Seattle\_QP1\_2x2Tiles.jxr
+- Seattle\_QP1\_4x1Tiles.jxr
+- Seattle\_Ov0\_1x1\_IndexTable0.jxr
+- Seattle\_Ov1\_1x1\_IndexTable0.jxr
+
+These files can be found in the directory Flags\_And\_Tiles.
+
+## 7.12 Reference file set Entropy\_Table\_Coverage
+
+This collection of eight .jxr files exercises table-switching for all of the 20 Adaptive VLC structures employed in the decoder. The files have been designed to test the use of the 20 different adaptive VLC decoding structures:
+
+- DecNumCBP
+- DecNumBlkCBP
+- AbsLevelIndDCLum
+- AbsLevelIndDCChr
+- DecFirstIndLPLum
+- DecIndLPLum0
+- DecIndLPLum1
+- DecFirstIndLPChr
+- DecIndLPChr0
+- DecIndLPChr1
+- AbsLevelIndLP0
+- AbsLevelIndLP1
+- DecFirstIndHPLum
+- DecIndHPLum0
+- DecIndHPLum1
+- DecFirstIndHPChr
+- DecIndHPChr0
+- DecIndHPChr1
+- AbsLevelIndHP0
+- AbsLevelIndHP1
+
+Correct decoding of the images in these files thus requires appropriate initialization and updating of the various code tables for each of these different adaptive VLC structures. In addition, YONLY and YUV444 images are included, because the DecNumBlkCBP table sizes are different for these two colour formats.
+
+The following files are included in the Entropy\_Table\_Coverage file set:
+
+- Boats.jxr
+- Boats\_YONLY.jxr
+- Dog.jxr
+- Dog\_YONLY.jxr
+- Seattle.jxr
+- Seattle\_YONLY.jxr
+- Skyscraper.jxr
+
+- Skyscraper\_YONLY.jxr
+
+These files can be found in the directory Entropy\_Table\_Coverage.
+
+## 7.13 Reference file set Shift\_Bits
+
+This collection of 16 .jxr files includes variation of the value of the syntax element SHIFT\_BITS, from 1 to 8, with OUTPUT\_BITDEPTH set to BD16 or BD16S.
+
+The following files are included in the Shift\_Bits file set:
+
+- CarHandle\_Shift1.jxr
+- CarHandle\_Shift2.jxr
+- CarHandle\_Shift3.jxr
+- CarHandle\_Shift4.jxr
+- CarHandle\_Shift5.jxr
+- CarHandle\_Shift6.jxr
+- CarHandle\_Shift7.jxr
+- CarHandle\_Shift8.jxr
+- Maui\_Shift1.jxr
+- Maui\_Shift2.jxr
+- Maui\_Shift3.jxr
+- Maui\_Shift4.jxr
+- Maui\_Shift5.jxr
+- Maui\_Shift6.jxr
+- Maui\_Shift7.jxr
+- Maui\_Shift8.jxr
+
+These files can be found in the directory Shift\_Bits.
+
+## 7.14 Reference file set MBLevel\_QP\_Coverage
+
+This collection of 20 .jxr files exercises the feature of having DC, Lowpass and Highpass quantization parameters being sent at the tile level (as opposed to the image level). For DC tile-level QPs, there is only one possible QP for a particular tile; for Lowpass and Highpass QPs, there may be up to 16 QPs assigned per tile. The exact number is varied across the files.
+
+Each of the images contain a tile (or multiple tiles) where the Lowpass and Highpass QPs are switched from macroblock to macroblock; the particular QP that is chosen for a given macroblock is selected from the table of available QPs for that band and tile by a QP index that is sent in the codestream.
+
+Additionally, the following syntax elements are varied in these files:
+
+- DC\_IMAGE\_PLANE\_UNIFORM\_FLAG
+- LP\_IMAGE\_PLANE\_UNIFORM\_FLAG
+- HP\_IMAGE\_PLANE\_UNIFORM\_FLAG
+- USE\_DC\_QP\_FLAG
+- USE\_LP\_QP\_FLAG
+
+The following files are included in the MBLevel\_QP\_Coverage file set:
+
+- Boat\_MBQP1.jxr
+- Boat\_MBQP2.jxr
+- Boat\_MBQP3.jxr
+- Boat\_MBQP4.jxr
+- Boat\_MBQP5.jxr
+- Boat\_MBQP6.jxr
+- Boat\_MBQP7.jxr
+
+- Bridge\_MBQP1.jxr
+- Bridge\_MBQP2.jxr
+- Dog\_MBQP1.jxr
+- Dog\_MBQP2.jxr
+- Skyscraper\_MBQP1.jxr
+- Skyscraper\_MBQP2.jxr
+- Skyscraper\_MBQP3.jxr
+- Skyscraper\_MBQP4.jxr
+- Skyscraper\_MBQP5.jxr
+- Skyscraper\_MBQP6.jxr
+- Skyscraper\_MBQP7.jxr
+- Skyscraper\_MBQP8.jxr
+- Skyscraper\_MBQP9.jxr
+
+These files can be found in the directory MBLevel\_QP\_Coverage.
+
+## **7.15 Reference file set Output\_Color\_Format\_Baseline**
+
+This collection of 16 .jxr files has the following syntax element characteristics:
+
+- The syntax element OUTPUT\_CLR\_FMT is varied across supported formats.
+
+NOTE – Each of these colour formats is supported in the Baseline profile of JPEG XR, as defined in Annex B of Rec. ITU-T T.832 | ISO/IEC 29199-2.
+
+The following files are included in the Output\_Color\_Format\_Baseline file set:
+
+- Maui-8bppGray\_64x64.jxr
+- Maui-16bppBGR555\_64x64.jxr
+- Maui-16bppBGR565\_64x64.jxr
+- Maui-16bppGray.jxr
+- Maui-16bppGrayFixedPoint\_64x64.jxr
+- Maui-24bppBGR\_64x64.jxr
+- Maui-24bppRGB\_64x64.jxr
+- Maui-32bppBGR.jxr
+- Maui-32bppBGR101010\_64x64.jxr
+- Maui-48bppRGB\_64x64.jxr
+- Maui-64bppRGBFixedPoint.jxr
+- Maui-48bppRGBFixedPoint\_64x64.jxr
+- Maui-BlackWhite\_Black1\_64x64.jxr
+- Maui-BlackWhite\_White1\_64x64.jxr
+- Maui\_Spat\_16bppGray.jxr
+- Maui\_Spat\_32bppBGR.jxr
+
+These files can be found in the directory Output\_Color\_Format\_Baseline.
+
+## **7.16 Reference file set Output\_Color\_Format\_Main**
+
+This collection of 79 .jxr files has the following syntax element characteristics:
+
+- The syntax element OUTPUT\_CLR\_FMT is varied across supported formats.
+- Formats with alpha channels are coded in planar format.
+
+NOTE – Each of these colour formats is supported in the Main profile of JPEG XR, as defined in Annex B of Rec. ITU-T T.832 | ISO/IEC 29199-2.
+
+The following files are included in the Output\_Color\_Format\_Main file set:
+
+- 3channel16\_noprof\_alpha.jxr
+- 3channel16\_noprof\_noalpha.jxr
+- 3channel16\_prof\_alpha.jxr
+- 3channel16\_prof\_noalpha.jxr
+- 3channel\_noprof\_alpha.jxr
+- 3channel\_noprof\_noalpha.jxr
+- 3channel\_prof\_alpha.jxr
+- 3channel\_prof\_noalpha.jxr
+- 4channel16\_noprof\_alpha.jxr
+- 4channel16\_noprof\_noalpha.jxr
+- 4channel16\_prof\_alpha.jxr
+- 4channel16\_prof\_noalpha.jxr
+- 4channel\_noprof\_alpha.jxr
+- 4channel\_noprof\_noalpha.jxr
+- 4channel\_prof\_alpha.jxr
+- 4channel\_prof\_noalpha.jxr
+- 5channel16\_noprof\_alpha.jxr
+- 5channel16\_noprof\_noalpha.jxr
+- 5channel16\_prof\_alpha.jxr
+- 5channel16\_prof\_noalpha.jxr
+- 5channel\_noprof\_alpha.jxr
+- 5channel\_noprof\_noalpha.jxr
+- 5channel\_prof\_alpha.jxr
+- 5channel\_prof\_noalpha.jxr
+- 6channel16\_noprof\_alpha.jxr
+- 6channel16\_noprof\_noalpha.jxr
+- 6channel16\_prof\_alpha.jxr
+- 6channel16\_prof\_noalpha.jxr
+- 6channel\_noprof\_alpha.jxr
+- 6channel\_noprof\_noalpha.jxr
+- 6channel\_prof\_alpha.jxr
+- 6channel\_prof\_noalpha.jxr
+- 7channel16\_noprof\_alpha.jxr
+- 7channel16\_noprof\_noalpha.jxr
+- 7channel16\_prof\_alpha.jxr
+- 7channel16\_prof\_noalpha.jxr
+- 7channel\_noprof\_alpha.jxr
+- 7channel\_noprof\_noalpha.jxr
+- 7channel\_prof\_alpha.jxr
+- 7channel\_prof\_noalpha.jxr
+- 8channel16\_noprof\_alpha.jxr
+- 8channel16\_noprof\_noalpha.jxr
+- 8channel16\_prof\_alpha.jxr
+- 8channel16\_prof\_noalpha.jxr
+- 8channel\_noprof\_alpha.jxr
+- 8channel\_noprof\_noalpha.jxr
+
+- 8channel\_prof\_alpha.jxr
+- 8channel\_prof\_noalpha.jxr
+- Maui-16bppGrayHalf\_64x64.jxr
+- Maui-32bppBGRA\_64x64.jxr
+- Maui-32bppCMYK\_64x64.jxr
+- Maui-32bppGrayFixedPoint\_64x64.jxr
+- Maui-32bppGrayFloat\_2\_64x64.jxr
+- Maui-32bppGrayFloat\_64x64.jxr
+- Maui-32bppRGBE.jxr
+- Maui-40bppCMYKA\_64x64.jxr
+- Maui-48bppRGBHalf\_64x64.jxr
+- Maui-64bppCMYK\_64x64.jxr
+- Maui-64bppRGBA\_64x64.jxr
+- Maui-64bppRGBAFixedPoint\_64x64.jxr
+- Maui-64bppRGBAHalf\_64x64.jxr
+- Maui-64bppRGBHalf.jxr
+- Maui-80bppCMYKA\_64x64.jxr
+- Maui-96bppRGBFixedPoint\_64x64.jxr
+- Maui-128bppRGBAFixedPoint\_64x64.jxr
+- Maui-128bppRGBAFloat\_64x64.jxr
+- Maui-128bppRGBFixedPoint.jxr
+- Maui-128bppRGBFloat\_64x64.jxr
+- P19d-32bppPBGRA.jxr
+- P19d-64bppPRGBA.jxr
+- P19d-64bppRGBAFixedPoint.jxr
+- P19d-128bppPRGBAFloat.jxr
+- 3channel16\_noprof\_noalpha\_Spat.jxr
+- 3channel\_noprof\_noalpha\_Spat.jxr
+- 4channel16\_noprof\_noalpha\_Spat.jxr
+- 4channel\_noprof\_noalpha\_Spat.jxr
+
+These files can be found in the directory Output\_Color\_Format\_Main.
+
+## 7.17 Reference file set Output\_Color\_Format\_Advanced
+
+This collection of 20 .jxr files has the following syntax element characteristics:
+
+The syntax element **OUTPUT\_CLR\_FMT** is varied across supported formats.
+
+NOTE – Each of these colour formats is supported in the Advanced profile of JPEG XR, as defined in Annex B of Rec. ITU-T T.832 | ISO/IEC 29199-2.
+
+The following files are included in the Output\_Color\_Format\_Advanced file set:
+
+- Maui-12bppYCC420.jxr
+- Maui-16bppYCC422.jxr
+- Maui-20bppYCC420Alpha.jxr
+- Maui-20bppYCC422.jxr
+- Maui-24bppYCC422Alpha.jxr
+- Maui-24bppYCC444.jxr
+- Maui-30bppYCC422Alpha.jxr
+- Maui-30bppYCC444.jxr
+
+- Maui-32bppCMYKDIRECT.jxr
+- Maui-32bppYCC422.jxr
+- Maui-32bppYCC444Alpha.jxr
+- Maui-40bppCMYKDIRECTAlpha.jxr
+- Maui-40bppYCC444Alpha.jxr
+- Maui-48bppYCC422Alpha.jxr
+- Maui-48bppYCC444.jxr
+- Maui-48bppYCC444FixedPoint.jxr
+- Maui-64bppCMYKDIRECT.jxr
+- Maui-64bppYCC444Alpha.jxr
+- Maui-64bppYCC444AlphaFixedPoint.jxr
+- Maui-80bppCMYKDIRECTAlpha.jxr
+
+These files can be found in the directory Output\_Color\_Format\_Advanced.
+
+## 7.18 Reference file set Alpha\_Interleaved
+
+This collection of seven .jxr files is to operate in conjunction with Output\_Color\_Format\_Main (clause 7.16). ALPHA\_IMAGE\_PLANE\_FLAG is set to TRUE, indicating that both the alpha image plane and primary image plane are stored within a single CODED\_IMAGE( ) syntax structure.
+
+The following files are included in the Alpha\_Interleaved file set:
+
+- Maui-32bppBGRA\_64x64\_Interleaved.jxr
+- Maui-40bppCMYKA\_64x64\_Interleaved.jxr
+- Maui-64bppRGBA\_64x64\_Interleaved.jxr
+- Maui-64bppRGBAFixedPoint\_64x64\_Interleaved.jxr
+- Maui-64bppRGBAHalf\_64x64\_Interleaved.jxr
+- Maui-80bppCMYKA\_64x64\_Interleaved.jxr
+- Maui-128bppRGBAFloat\_64x64\_Interleaved.jxr
+
+These files can be found in the directory Alpha\_Interleaved.
+
+## 7.19 Reference file set Hard\_Tile\_Boundaries
+
+This collection of 58 .jxr files has the same type of syntax element characteristics as in the BasicAndOverlap\_4x4Tile file set (clause 7.3), except that in the files in Hard\_Tile\_Boundaries, the syntax element RESERVED\_C is set to 9, resulting in DisableTileOverlapFlag being set to TRUE. The remaining note syntax characteristics are repeated here:
+
+- The FREQUENCY\_MODE\_CODESTREAM\_FLAG syntax element is set to FALSE (spatial mode) or TRUE (frequency mode).
+- The OVERLAP\_MODE is varied between the values 0, 1 and 2.
+- The INTERNAL\_CLR\_FMT is set to YUV444, YUV422, YUV420 or YONLY.
+- The QP (for all colour channels and all bands) is set to 1 or 10.
+- NUM\_HOR\_TILES\_MINUS1 and NUM\_VER\_TILES\_MINUS1 are both set to 1 or 3.
+
+The following files are included in the Hard\_Tile\_Boundaries file set:
+
+- Seattle\_Spat\_Ov0\_2x2\_YUV420\_HardTiles\_QP1.jxr
+- Seattle\_Spat\_Ov0\_2x2\_YUV420\_HardTiles\_QP10.jxr
+- Seattle\_Spat\_Ov0\_2x2\_YUV422\_HardTiles\_QP1.jxr
+- Seattle\_Spat\_Ov0\_2x2\_YUV422\_HardTiles\_QP10.jxr
+- Seattle\_Spat\_Ov0\_2x2\_YUV444\_HardTiles\_QP1.jxr
+- Seattle\_Spat\_Ov0\_2x2\_YUV444\_HardTiles\_QP10.jxr
+- Seattle\_Spat\_Ov0\_4x4\_YONLY\_HardTiles\_QP10.jxr
+
+- Seattle\_Spat\_Ov0\_4x4\_YUV444\_HardTiles\_QP1.jxr
+- Seattle\_Spat\_Ov0\_4x4\_YUV444\_HardTiles\_QP10.jxr
+- Seattle\_Spat\_Ov1\_2x2\_YUV420\_HardTiles\_QP1.jxr
+- Seattle\_Spat\_Ov1\_2x2\_YUV420\_HardTiles\_QP10.jxr
+- Seattle\_Spat\_Ov1\_2x2\_YUV422\_HardTiles\_QP1.jxr
+- Seattle\_Spat\_Ov1\_2x2\_YUV422\_HardTiles\_QP10.jxr
+- Seattle\_Spat\_Ov1\_2x2\_YUV444\_HardTiles\_QP1.jxr
+- Seattle\_Spat\_Ov1\_2x2\_YUV444\_HardTiles\_QP10.jxr
+- Seattle\_Spat\_Ov1\_4x4\_YONLY\_HardTiles\_QP10.jxr
+- Seattle\_Spat\_Ov1\_4x4\_YUV420\_HardTiles\_QP1.jxr
+- Seattle\_Spat\_Ov1\_4x4\_YUV420\_HardTiles\_QP10.jxr
+- Seattle\_Spat\_Ov1\_4x4\_YUV444\_HardTiles\_QP1.jxr
+- Seattle\_Spat\_Ov1\_4x4\_YUV444\_HardTiles\_QP10.jxr
+- Seattle\_Spat\_Ov2\_2x2\_YUV420\_HardTiles\_QP1.jxr
+- Seattle\_Spat\_Ov2\_2x2\_YUV420\_HardTiles\_QP10.jxr
+- Seattle\_Spat\_Ov2\_2x2\_YUV422\_HardTiles\_QP1.jxr
+- Seattle\_Spat\_Ov2\_2x2\_YUV422\_HardTiles\_QP10.jxr
+- Seattle\_Spat\_Ov2\_2x2\_YUV444\_HardTiles\_QP1.jxr
+- Seattle\_Spat\_Ov2\_2x2\_YUV444\_HardTiles\_QP10.jxr
+- Seattle\_Spat\_Ov2\_4x4\_YONLY\_HardTiles\_QP10.jxr
+- Seattle\_Spat\_Ov2\_4x4\_YUV444\_HardTiles\_QP1.jxr
+- Seattle\_Spat\_Ov2\_4x4\_YUV444\_HardTiles\_QP10.jxr
+- Seattle\_Freq\_Ov0\_2x2\_YUV420\_HardTiles\_QP1.jxr
+- Seattle\_Freq\_Ov0\_2x2\_YUV420\_HardTiles\_QP10.jxr
+- Seattle\_Freq\_Ov0\_2x2\_YUV422\_HardTiles\_QP1.jxr
+- Seattle\_Freq\_Ov0\_2x2\_YUV422\_HardTiles\_QP10.jxr
+- Seattle\_Freq\_Ov0\_2x2\_YUV444\_HardTiles\_QP1.jxr
+- Seattle\_Freq\_Ov0\_2x2\_YUV444\_HardTiles\_QP10.jxr
+- Seattle\_Freq\_Ov0\_4x4\_YONLY\_HardTiles\_QP10.jxr
+- Seattle\_Freq\_Ov0\_4x4\_YUV444\_HardTiles\_QP1.jxr
+- Seattle\_Freq\_Ov0\_4x4\_YUV444\_HardTiles\_QP10.jxr
+- Seattle\_Freq\_Ov1\_2x2\_YUV420\_HardTiles\_QP1.jxr
+- Seattle\_Freq\_Ov1\_2x2\_YUV420\_HardTiles\_QP10.jxr
+- Seattle\_Freq\_Ov1\_2x2\_YUV422\_HardTiles\_QP1.jxr
+- Seattle\_Freq\_Ov1\_2x2\_YUV422\_HardTiles\_QP10.jxr
+- Seattle\_Freq\_Ov1\_2x2\_YUV444\_HardTiles\_QP1.jxr
+- Seattle\_Freq\_Ov1\_2x2\_YUV444\_HardTiles\_QP10.jxr
+- Seattle\_Freq\_Ov1\_4x4\_YONLY\_HardTiles\_QP10.jxr
+- Seattle\_Freq\_Ov1\_4x4\_YUV420\_HardTiles\_QP1.jxr
+- Seattle\_Freq\_Ov1\_4x4\_YUV420\_HardTiles\_QP10.jxr
+- Seattle\_Freq\_Ov1\_4x4\_YUV444\_HardTiles\_QP1.jxr
+- Seattle\_Freq\_Ov1\_4x4\_YUV444\_HardTiles\_QP10.jxr
+- Seattle\_Freq\_Ov2\_2x2\_YUV420\_HardTiles\_QP1.jxr
+- Seattle\_Freq\_Ov2\_2x2\_YUV420\_HardTiles\_QP10.jxr
+- Seattle\_Freq\_Ov2\_2x2\_YUV422\_HardTiles\_QP1.jxr
+- Seattle\_Freq\_Ov2\_2x2\_YUV422\_HardTiles\_QP10.jxr
+
+- Seattle\_Freq\_Ov2\_2x2\_YUV444\_HardTiles\_QP1.jxr
+- Seattle\_Freq\_Ov2\_2x2\_YUV444\_HardTiles\_QP10.jxr
+- Seattle\_Freq\_Ov2\_4x4\_YONLY\_HardTiles\_QP10.jxr
+- Seattle\_Freq\_Ov2\_4x4\_YUV444\_HardTiles\_QP1.jxr
+- Seattle\_Freq\_Ov2\_4x4\_YUV444\_HardTiles\_QP10.jxr
+
+These files can be found in the directory Hard\_Tile\_Boundaries.
+
+## 7.20 Reference file set Index\_Table\_Use
+
+This collection of six .jxr files includes variations in the ordering of data packets within the file. The order for interpretation is indicated via the Index Table. Changes made include:
+
+- Placing the data packet for the top left tile of the image at the end of the data file.
+- Reusing data packets by having multiple entries in the Index Table be equal to each other.
+
+The following files are included in the Index\_Table\_Use file set:
+
+- Boats\_IdxTbl\_Ov0.jxr
+- Boats\_IdxTbl\_Ov1.jxr
+- Boats\_IdxTbl\_Ov2.jxr
+- NotANaturalImage\_SharedTile\_Ov0.jxr
+- NotANaturalImage\_SharedTile\_Ov1.jxr
+- NotANaturalImage\_SharedTile\_Ov2.jxr
+
+These files can be found in the directory Index\_Table\_Use.
+
+## 7.21 Reference file set Levels
+
+This collection of 38 .jxr files has the following syntax element characteristics:
+
+- The LEVEL\_IDC syntax element is set to 8, 16, 32, 64, 128 or 255.
+
+The following files are included in the Levels file set:
+
+- Level4\_cols\_Freq.jxr
+- Level4\_cols\_Spat.jxr
+- Level4\_rows\_Freq.jxr
+- Level4\_rows\_Spat.jxr
+- Level8\_cols\_Freq.jxr
+- Level8\_cols\_Spat.jxr
+- Level8\_rows\_Freq.jxr
+- Level8\_rows\_Spat.jxr
+- Level16\_cols\_Freq.jxr
+- Level16\_cols\_Spat.jxr
+- Level16\_rows\_Freq.jxr
+- Level16\_rows\_Spat.jxr
+- Level32\_cols\_Freq.jxr
+- Level32\_cols\_Spat.jxr
+- Level32\_rows\_Freq.jxr
+- Level32\_rows\_Spat.jxr
+- Level64\_cols\_Freq.jxr
+- Level64\_cols\_Spat.jxr
+- Level64\_rows\_Freq.jxr
+- Level64\_rows\_Spat.jxr
+- Level128\_cols\_Freq.jxr
+
+- Level128\_cols\_Spat.jxr
+- Level128\_rows\_Freq.jxr
+- Level128\_rows\_Spat.jxr
+- MediumLevel8.jxr
+- MediumLevel16.jxr
+- MediumLevel32.jxr
+- WideLevel64.jxr
+- WideLevel128.jxr
+- VeryWideLevel255.jxr
+- Level255\_cols\_Spat\_1x1.jxr
+- Level255\_rows\_Spat\_1x1.jxr
+- Level16\_cols\_Spat\_1x1.jxr
+- Level16\_rows\_Spat\_1x1.jxr
+- Level4\_cols\_Spat\_1x1.jxr
+- Level4\_rows\_Spat\_1x1.jxr
+- Level8\_cols\_Spat\_1x1.jxr
+- Level8\_rows\_Spat\_1x1.jxr
+
+These files can be found in the directory Levels.
+
+## 7.22 Reference file set Long\_Word\_Flag
+
+This collection of two .jxr files has the following syntax element characteristics:
+
+- The LONG\_WORD\_FLAG syntax element is set to FALSE.
+
+The following files are included in the Long\_Word\_Flag file set:
+
+- Boats\_LWF\_Ov0.jxr
+- Boats\_LWF\_Ov1.jxr
+
+These files can be found in the directory Long\_Word\_Flag.
+
+## 7.23 Reference file set Windowing
+
+This collection of eight .jxr files has the following syntax element characteristics:
+
+- The WINDOWING\_FLAG syntax element is set to TRUE.
+- The TOP\_MARGIN syntax element is set to 1, 5, 8, 14, 15 or 19.
+- The LEFT\_MARGIN syntax element is set to 0, 1, 2, 8, 14 or 38.
+- The BOTTOM\_MARGIN syntax element is set to 1, 4, 8 or 15.
+- The RIGHT\_MARGIN syntax element is set to 1, 7, 8 or 15.
+
+The following files are included in the Windowing file set:
+
+- Windowed1.jxr
+- Windowed2.jxr
+- Windowed3.jxr
+- Windowed4.jxr
+- Windowed5.jxr
+- Windowed6.jxr
+- Windowed7.jxr
+- Windowed8.jxr
+
+These files can be found in the directory Windowing.
+
+## 7.24 Reference file set Chroma\_Centering
+
+This collection of 30 .jxr files has the following syntax element characteristics:
+
+- The **INTERNAL\_CLR\_FMT** syntax element is set to YUV420 or YUV422.
+- The **CHROMA\_CENTERING\_X** syntax element is set to 0, 1, 2, 3 or 4.
+- The **CHROMA\_CENTERING\_Y** syntax element is set to 0, 1, 2, 3 or 4.
+
+The following files are included in the Chroma\_Centering file set:
+
+- Seattle\_420\_CCX\_0\_CCY\_0.jxr
+- Seattle\_420\_CCX\_0\_CCY\_1.jxr
+- Seattle\_420\_CCX\_0\_CCY\_2.jxr
+- Seattle\_420\_CCX\_0\_CCY\_3.jxr
+- Seattle\_420\_CCX\_0\_CCY\_4.jxr
+- Seattle\_420\_CCX\_1\_CCY\_0.jxr
+- Seattle\_420\_CCX\_1\_CCY\_1.jxr
+- Seattle\_420\_CCX\_1\_CCY\_2.jxr
+- Seattle\_420\_CCX\_1\_CCY\_3.jxr
+- Seattle\_420\_CCX\_1\_CCY\_4.jxr
+- Seattle\_420\_CCX\_2\_CCY\_0.jxr
+- Seattle\_420\_CCX\_2\_CCY\_1.jxr
+- Seattle\_420\_CCX\_2\_CCY\_2.jxr
+- Seattle\_420\_CCX\_2\_CCY\_3.jxr
+- Seattle\_420\_CCX\_2\_CCY\_4.jxr
+- Seattle\_420\_CCX\_3\_CCY\_0.jxr
+- Seattle\_420\_CCX\_3\_CCY\_1.jxr
+- Seattle\_420\_CCX\_3\_CCY\_2.jxr
+- Seattle\_420\_CCX\_3\_CCY\_3.jxr
+- Seattle\_420\_CCX\_3\_CCY\_4.jxr
+- Seattle\_420\_CCX\_4\_CCY\_0.jxr
+- Seattle\_420\_CCX\_4\_CCY\_1.jxr
+- Seattle\_420\_CCX\_4\_CCY\_2.jxr
+- Seattle\_420\_CCX\_4\_CCY\_3.jxr
+- Seattle\_420\_CCX\_4\_CCY\_4.jxr
+- Seattle\_422\_CCX\_0.jxr
+- Seattle\_422\_CCX\_1.jxr
+- Seattle\_422\_CCX\_2.jxr
+- Seattle\_422\_CCX\_3.jxr
+- Seattle\_422\_CCX\_4.jxr
+
+These files can be found in the directory Chroma\_Centering.
+
+## 7.25 Reference file set Tag\_Based\_Container
+
+This collection of six .jxr files exercises the IFD entries described in Rec. ITU-T T.832 | ISO/IEC 29199-2 Annex A.
+
+The following files are included in the Tag\_Based\_Container file set:
+
+- Boats1\_IFD\_Tags.jxr
+- Boats2\_IFD\_Tags.jxr
+- Seattle\_IFD\_Tags.jxr
+- Boats1\_IFD\_Tags\_ByteCount0.jxr
+
+- Boats2\_IFD\_Tags\_ByteCount0.jxr
+- Seattle\_IFD\_Tags\_ByteCount0.jxr
+
+These files can be found in the directory Tag\_Based\_Container.
+
+## 7.26 Reference file set Tile\_Sizes
+
+This collection of 28 .jxr files has the following syntax element characteristics:
+
+- The value of NUM\_HOR\_TILES\_MINUS1 is set to 0, 3, 7, 14, 30, 62, 126 or 253.
+- The value of NUM\_VER\_TILES\_MINUS1 is set to 0, 2, 4, 9, 20, 41, 83 or 168.
+
+The following files are included in the Tile\_Sizes file set:
+
+- P01\_u\_1\_3\_Freq.jxr
+- P01\_u\_1\_3\_Spat.jxr
+- P01\_u\_1\_5\_Freq.jxr
+- P01\_u\_1\_5\_Spat.jxr
+- P01\_u\_1\_10\_Freq.jxr
+- P01\_u\_1\_10\_Spat.jxr
+- P01\_u\_1\_21\_Freq.jxr
+- P01\_u\_1\_21\_Spat.jxr
+- P01\_u\_1\_42\_Freq.jxr
+- P01\_u\_1\_42\_Spat.jxr
+- P01\_u\_1\_84\_Freq.jxr
+- P01\_u\_1\_84\_Spat.jxr
+- P01\_u\_1\_169\_Freq.jxr
+- P01\_u\_1\_169\_Spat.jxr
+- P01\_u\_4\_1\_Freq.jxr
+- P01\_u\_4\_1\_Spat.jxr
+- P01\_u\_8\_1\_Freq.jxr
+- P01\_u\_8\_1\_Spat.jxr
+- P01\_u\_15\_1\_Freq.jxr
+- P01\_u\_15\_1\_Spat.jxr
+- P01\_u\_31\_1\_Freq.jxr
+- P01\_u\_31\_1\_Spat.jxr
+- P01\_u\_63\_1\_Freq.jxr
+- P01\_u\_63\_1\_Spat.jxr
+- P01\_u\_127\_1\_Freq.jxr
+- P01\_u\_127\_1\_Spat.jxr
+- P01\_u\_254\_1\_Freq.jxr
+- P01\_u\_254\_1\_Spat.jxr
+
+These files can be found in the directory Tile\_Sizes.
+
+## 7.27 Reference file set Red-Blue-Not-Swapped
+
+This collection of six .jxr files contains images in the BGR555, BGR565 and BGR101010 colour format that make use of the RED\_BLUE\_SWAPPED\_FLAG of the codestream, indicating a component order in which red is in the first and blue in the last channel. The set consists of the files
+
+- Maui\_555\_RBns\_Flg\_Off.jxr
+- Maui\_555\_RBns\_Flg\_On.jxr
+- Maui\_565\_RBns\_Flg\_Off.jxr
+
+- Maui\_565\_RBns\_Flg\_On.jxr
+- Maui\_101010\_RBns\_Flg\_Off.jxr
+- Maui\_101010\_RBns\_Flg\_On.jxr
+
+## 7.28 Reference file set Use-DCLP-QP-Flag
+
+In this collection of seven .jxr files, the variable quantization options of JPEG XR USE\_DC/LP\_QP\_FLAG are tested and the number of quantizer for the three bands (DC,LP,HP) are varied between 1, 4, 8 and 16. The set consists of the files:
+
+- Seattle\_L01n\_H12u.jxr
+- Seattle\_L01u\_H12n.jxr
+- Seattle\_L08n\_H04u.jxr
+- Seattle\_L08u\_H04n.jxr
+- Seattle\_L08u\_H04u.jxr
+- Seattle\_L16n\_H01u.jxr
+- Seattle\_L16u\_H01n.jxr
+
+## 7.29 Reference file set Trim-Flexbits
+
+This set of 16 .jxr files tests the TRIM-FLEXBITS option of the decoder by varying the number of flexbits to trim off between zero and 15. It consists of the following files:
+
+- Random\_Trim0.jxr
+- Random\_Trim1.jxr
+- Random\_Trim2.jxr
+- Random\_Trim3.jxr
+- Random\_Trim4.jxr
+- Random\_Trim5.jxr
+- Random\_Trim6.jxr
+- Random\_Trim7.jxr
+- Random\_Trim8.jxr
+- Random\_Trim9.jxr
+- Random\_Trim10.jxr
+- Random\_Trim11.jxr
+- Random\_Trim12.jxr
+- Random\_Trim13.jxr
+- Random\_Trim14.jxr
+- Random\_Trim15.jxr
+
+## 7.30 Reference file set Spatial\_XFRM
+
+This set of eight .jxr files varies the spatial transformation in the image header between all eight possible values. It consists of the following files:
+
+- Seattle\_Subordinate0.jxr
+- Seattle\_Subordinate1.jxr
+- Seattle\_Subordinate2.jxr
+- Seattle\_Subordinate3.jxr
+- Seattle\_Subordinate4.jxr
+- Seattle\_Subordinate5.jxr
+- Seattle\_Subordinate6.jxr
+- Seattle\_Subordinate7.jxr
+
+## 7.31 Reference file set BoxBased-Format
+
+The directory BoxBased-Format contains 159 .jxr files that use the alternative box-based file format representation defined in Rec. ITU-T T.801 | ISO/IEC 15444-2. They are alternative representations of files found in the directories Varied\_Internal\_Color\_Format, Output\_Color\_Format\_Baseline, Output\_Color\_Format\_Main and Output\_Color\_Format\_Advanced:
+
+- 3channel16\_noprof\_alpha\_Interleaved.jpx
+- 3channel16\_noprof\_alpha.jpx
+- 3channel16\_noprof\_noalpha.jpx
+- 3channel16\_prof\_alpha\_Interleaved.jpx
+- 3channel16\_prof\_alpha.jpx
+- 3channel16\_prof\_noalpha.jpx
+- 3channel\_noprof\_alpha\_Interleaved.jpx
+- 3channel\_noprof\_alpha.jpx
+- 3channel\_noprof\_noalpha.jpx
+- 3channel\_prof\_alpha\_Interleaved.jpx
+- 3channel\_prof\_alpha.jpx
+- 3channel\_prof\_noalpha.jpx
+- 4channel16\_noprof\_alpha\_Interleaved.jpx
+- 4channel16\_noprof\_alpha.jpx
+- 4channel16\_noprof\_noalpha.jpx
+- 4channel16\_prof\_alpha\_Interleaved.jpx
+- 4channel16\_prof\_alpha.jpx
+- 4channel16\_prof\_noalpha.jpx
+- 4channel\_noprof\_alpha\_Interleaved.jpx
+- 4channel\_noprof\_alpha.jpx
+- 4channel\_noprof\_noalpha.jpx
+- 4channel\_prof\_alpha\_Interleaved.jpx
+- 4channel\_prof\_alpha.jpx
+- 4channel\_prof\_noalpha.jpx
+- 5channel16\_noprof\_alpha\_Interleaved.jpx
+- 5channel16\_noprof\_alpha.jpx
+- 5channel16\_noprof\_noalpha.jpx
+- 5channel16\_prof\_alpha\_Interleaved.jpx
+- 5channel16\_prof\_alpha.jpx
+- 5channel16\_prof\_noalpha.jpx
+- 5channel\_noprof\_alpha\_Interleaved.jpx
+- 5channel\_noprof\_alpha.jpx
+- 5channel\_noprof\_noalpha.jpx
+- 5channel\_prof\_alpha\_Interleaved.jpx
+- 5channel\_prof\_alpha.jpx
+- 5channel\_prof\_noalpha.jpx
+- 6channel16\_noprof\_alpha\_Interleaved.jpx
+- 6channel16\_noprof\_alpha.jpx
+- 6channel16\_noprof\_noalpha.jpx
+- 6channel16\_prof\_alpha\_Interleaved.jpx
+- 6channel16\_prof\_alpha.jpx
+
+- 6channel16\_prof\_noalpha.jpg
+- 6channel\_noprof\_alpha\_Interleaved.jpg
+- 6channel\_noprof\_alpha.jpg
+- 6channel\_noprof\_noalpha.jpg
+- 6channel\_prof\_alpha\_Interleaved.jpg
+- 6channel\_prof\_alpha.jpg
+- 6channel\_prof\_noalpha.jpg
+- 7channel16\_noprof\_alpha\_Interleaved.jpg
+- 7channel16\_noprof\_alpha.jpg
+- 7channel16\_noprof\_noalpha.jpg
+- 7channel16\_prof\_alpha\_Interleaved.jpg
+- 7channel16\_prof\_alpha.jpg
+- 7channel16\_prof\_noalpha.jpg
+- 7channel\_noprof\_alpha\_Interleaved.jpg
+- 7channel\_noprof\_alpha.jpg
+- 7channel\_noprof\_noalpha.jpg
+- 7channel\_prof\_alpha\_Interleaved.jpg
+- 7channel\_prof\_alpha.jpg
+- 7channel\_prof\_noalpha.jpg
+- 8channel16\_noprof\_alpha\_Interleaved.jpg
+- 8channel16\_noprof\_alpha.jpg
+- 8channel16\_noprof\_noalpha.jpg
+- 8channel16\_prof\_alpha\_Interleaved.jpg
+- 8channel16\_prof\_alpha.jpg
+- 8channel16\_prof\_noalpha.jpg
+- 8channel\_noprof\_alpha\_Interleaved.jpg
+- 8channel\_noprof\_alpha.jpg
+- 8channel\_noprof\_noalpha.jpg
+- 8channel\_prof\_alpha\_Interleaved.jpg
+- 8channel\_prof\_alpha.jpg
+- 8channel\_prof\_noalpha.jpg
+- Maui-128bppRGBAFixedPoint\_64x64\_Interleaved.jpg
+- Maui-128bppRGBAFixedPoint\_64x64.jpg
+- Maui-128bppRGBAFloat\_64x64\_Interleaved.jpg
+- Maui-128bppRGBAFloat\_64x64.jpg
+- Maui-128bppRGBFixedPoint.jpg
+- Maui-128bppRGBFloat\_64x64.jpg
+- Maui-12bppYCC420.jpg
+- Maui-16bppBGR555\_64x64.jpg
+- Maui-16bppBGR565\_64x64.jpg
+- Maui-16bppGrayFixedPoint\_64x64.jpg
+- Maui-16bppGrayHalf\_64x64.jpg
+- Maui-16bppGray.jpg
+- Maui-16bppYCC422.jpg
+- Maui-20bppYCC420Alpha\_Interleaved.jpg
+- Maui-20bppYCC420Alpha.jpg
+
+- Maui-20bppYCC422.jpx
+- Maui-24bppBGR\_64x64.jpx
+- Maui-24bppRGB\_64x64.jpx
+- Maui-24bppYCC422Alpha\_Interleaved.jpx
+- Maui-24bppYCC422Alpha.jpx
+- Maui-24bppYCC444.jpx
+- Maui-30bppYCC422Alpha\_Interleaved.jpx
+- Maui-30bppYCC422Alpha.jpx
+- Maui-30bppYCC444.jpx
+- Maui-32bppBGR101010\_64x64.jpx
+- Maui-32bppBGRA\_64x64\_Interleaved.jpx
+- Maui-32bppBGRA\_64x64.jpx
+- Maui-32bppBGR.jpx
+- Maui-32bppCMYK\_64x64.jpx
+- Maui-32bppCMYKDIRECT.jpx
+- Maui-32bppGrayFixedPoint\_64x64.jpx
+- Maui-32bppGrayFloat\_2\_64x64.jpx
+- Maui-32bppGrayFloat\_64x64.jpx
+- Maui-32bppYCC422.jpx
+- Maui-32bppYCC444Alpha\_Interleaved.jpx
+- Maui-32bppYCC444Alpha.jpx
+- Maui-40bppCMYKA\_64x64\_Interleaved.jpx
+- Maui-40bppCMYKA\_64x64.jpx
+- Maui-40bppCMYKDIRECTAlpha\_Interleaved.jpx
+- Maui-40bppCMYKDIRECTAlpha.jpx
+- Maui-40bppYCC444Alpha\_Interleaved.jpx
+- Maui-40bppYCC444Alpha.jpx
+- Maui-48bppRGB\_64x64.jpx
+- Maui-48bppRGBFixedPoint\_64x64.jpx
+- Maui-48bppRGBHalf\_64x64.jpx
+- Maui-48bppYCC422Alpha\_Interleaved.jpx
+- Maui-48bppYCC422Alpha.jpx
+- Maui-48bppYCC444FixedPoint.jpx
+- Maui-48bppYCC444.jpx
+- Maui-64bppCMYK\_64x64.jpx
+- Maui-64bppCMYKDIRECT.jpx
+- Maui-64bppRGBA\_64x64\_Interleaved.jpx
+- Maui-64bppRGBA\_64x64.jpx
+- Maui-64bppRGBAFixedPoint\_64x64\_Interleaved.jpx
+- Maui-64bppRGBAFixedPoint\_64x64.jpx
+- Maui-64bppRGBAHalf\_64x64\_Interleaved.jpx
+- Maui-64bppRGBAHalf\_64x64.jpx
+- Maui-64bppRGBFixedPoint.jpx
+- Maui-64bppRGBHalf.jpx
+- Maui-64bppYCC444AlphaFixedPoint\_Interleaved.jpx
+- Maui-64bppYCC444AlphaFixedPoint.jpx
+
+- Maui-64bppYCC444Alpha\_Interleaved.jpx
+- Maui-64bppYCC444Alpha.jpx
+- Maui-80bppCMYKA\_64x64\_Interleaved.jpx
+- Maui-80bppCMYKA\_64x64.jpx
+- Maui-80bppCMYKDIRECTAlpha\_Interleaved.jpx
+- Maui-80bppCMYKDIRECTAlpha.jpx
+- Maui-8bppGray\_64x64.jpx
+- Maui-96bppRGBFixedPoint\_64x64.jpx
+- Maui-BlackWhite\_Black1\_64x64.jpx
+- Maui-BlackWhite\_White1\_64x64.jpx
+- P19d-128bppPRGBAFloat\_Interleaved.jpx
+- P19d-128bppPRGBAFloat.jpx
+- P19d-32bppPBGRA\_Interleaved.jpx
+- P19d-32bppPBGRA.jpx
+- P19d-64bppPRGBA\_Interleaved.jpx
+- P19d-64bppPRGBA.jpx
+- P19d-64bppRGBAFixedPoint\_Interleaved.jpx
+- P19d-64bppRGBAFixedPoint.jpx
+- Seattle\_QP\_1\_YUV\_420\_Ov1.jpx
+- Seattle\_QP\_1\_YUV\_420\_Ov2.jpx
+- Seattle\_QP\_1\_YUV\_422\_Ov1.jpx
+- Seattle\_QP\_1\_YUV\_422\_Ov2.jpx
+- Seattle\_QP\_5\_YUV\_420\_Ov1.jpx
+- Seattle\_QP\_5\_YUV\_420\_Ov2.jpx
+- Seattle\_QP\_5\_YUV\_422\_Ov1.jpx
+- Seattle\_QP\_5\_YUV\_422\_Ov2.jpx
+
+# SERIES OF ITU-T RECOMMENDATIONS
+
+|                 |                                                                                             |
+|-----------------|---------------------------------------------------------------------------------------------|
+| Series A        | Organization of the work of ITU-T                                                           |
+| Series D        | General tariff principles                                                                   |
+| Series E        | Overall network operation, telephone service, service operation and human factors           |
+| Series F        | Non-telephone telecommunication services                                                    |
+| Series G        | Transmission systems and media, digital systems and networks                                |
+| Series H        | Audiovisual and multimedia systems                                                          |
+| Series I        | Integrated services digital network                                                         |
+| Series J        | Cable networks and transmission of television, sound programme and other multimedia signals |
+| Series K        | Protection against interference                                                             |
+| Series L        | Construction, installation and protection of cables and other elements of outside plant     |
+| Series M        | Telecommunication management, including TMN and network maintenance                         |
+| Series N        | Maintenance: international sound programme and television transmission circuits             |
+| Series O        | Specifications of measuring equipment                                                       |
+| Series P        | Terminals and subjective and objective assessment methods                                   |
+| Series Q        | Switching and signalling                                                                    |
+| Series R        | Telegraph transmission                                                                      |
+| Series S        | Telegraph services terminal equipment                                                       |
+| <b>Series T</b> | <b>Terminals for telematic services</b>                                                     |
+| Series U        | Telegraph switching                                                                         |
+| Series V        | Data communication over the telephone network                                               |
+| Series X        | Data networks, open system communications and security                                      |
+| Series Y        | Global information infrastructure, Internet protocol aspects and next-generation networks   |
+| Series Z        | Languages and general software aspects for telecommunication systems                        |
\ No newline at end of file
diff --git a/marked/T/T-REC-T.872-201206-I_PDF-E/6ed175c791b5e156d9c98a8dbcc3318c_img.jpg b/marked/T/T-REC-T.872-201206-I_PDF-E/6ed175c791b5e156d9c98a8dbcc3318c_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..76a97e082ab0c2356deb239bbb48c4ff9f312414
--- /dev/null
+++ b/marked/T/T-REC-T.872-201206-I_PDF-E/6ed175c791b5e156d9c98a8dbcc3318c_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:ddb7c24dc3172b9be33f9e4b3653ec8bf23bf3ccf471e36e0c3534034054a4ac
+size 6616
diff --git a/marked/T/T-REC-T.872-201206-I_PDF-E/raw.md b/marked/T/T-REC-T.872-201206-I_PDF-E/raw.md
new file mode 100644
index 0000000000000000000000000000000000000000..45300d2c9cb904c0ff2cb49c675c841ac84409d3
--- /dev/null
+++ b/marked/T/T-REC-T.872-201206-I_PDF-E/raw.md
@@ -0,0 +1,311 @@
+
+
+International Telecommunication Union
+
+# ITU-T
+
+TELECOMMUNICATION  
+STANDARDIZATION SECTOR  
+OF ITU
+
+# T.872
+
+(06/2012)
+
+SERIES T: TERMINALS FOR TELEMATIC SERVICES  
+Still-image compression – JPEG-1 extensions
+
+---
+
+**Information technology – Digital compression  
+and coding of continuous-tone still images:  
+Application to printing systems**
+
+Recommendation ITU-T T.872
+
+![ITU logo: a globe with red lightning bolts and the text 'ITU International Telecommunication Union'](6ed175c791b5e156d9c98a8dbcc3318c_img.jpg)
+
+The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue globe with two red lightning bolts striking it. To the right of the globe, the text 'ITU' is written in a large, bold, blue font, and below it, the words 'International Telecommunication Union' are written in a smaller, blue font.
+
+ITU logo: a globe with red lightning bolts and the text 'ITU International Telecommunication Union'
+
+# ITU-T T-SERIES RECOMMENDATIONS **TERMINALS FOR TELEMATIC SERVICES**
+
+|                                                     |                    |
+|-----------------------------------------------------|--------------------|
+| Facsimile – Framework                               | T.0–T.19           |
+| Still-image compression – Test charts               | T.20–T.29          |
+| Facsimile – Group 3 protocols                       | T.30–T.39          |
+| Colour representation                               | T.40–T.49          |
+| Character coding                                    | T.50–T.59          |
+| Facsimile – Group 4 protocols                       | T.60–T.69          |
+| Telematic services – Framework                      | T.70–T.79          |
+| Still-image compression – JPEG-1, Bi-level and JBIG | T.80–T.89          |
+| Telematic services – ISDN Terminals and protocols   | T.90–T.99          |
+| Videotext – Framework                               | T.100–T.109        |
+| Data protocols for multimedia conferencing          | T.120–T.149        |
+| Telewriting                                         | T.150–T.159        |
+| Multimedia and hypermedia framework                 | T.170–T.189        |
+| Cooperative document handling                       | T.190–T.199        |
+| Telematic services – Interworking                   | T.300–T.399        |
+| Open document architecture                          | T.400–T.429        |
+| Document transfer and manipulation                  | T.430–T.449        |
+| Document application profile                        | T.500–T.509        |
+| Communication application profile                   | T.510–T.559        |
+| Telematic services – Equipment characteristics      | T.560–T.649        |
+| Still-image compression – JPEG 2000                 | T.800–T.829        |
+| Still-image compression   JPEG XR                   | T.830–T.849        |
+| <b>Still-image compression – JPEG-1 extensions</b>  | <b>T.850–T.899</b> |
+
+*For further details, please refer to the list of ITU-T Recommendations.*
+
+# **Information technology – Digital compression and coding of continuous-tone still images: Application to printing systems**
+
+## **Summary**
+
+Recommendation ITU-T T.872 | ISO/IEC 10918-6 specifies a subset of features and application tools for printing applications that encode or decode images based on the JPEG encoding of ITU-T T.81 | ISO/IEC 10918-1. Its creation was proposed by members of the digital printing industry to ensure that applications developed for printing systems can exchange JPEG images.
+
+## **History**
+
+| Edition | Recommendation | Approval   | Study Group |
+|---------|----------------|------------|-------------|
+| 1.0     | ITU-T T.872    | 2012-06-29 | 16          |
+
+## FOREWORD
+
+The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis.
+
+The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics.
+
+The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1.
+
+In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC.
+
+## NOTE
+
+In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party.
+
+## INTELLECTUAL PROPERTY RIGHTS
+
+ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process.
+
+As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at <http://www.itu.int/ITU-T/ipr/>.
+
+© ITU 2013
+
+All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU.
+
+## CONTENTS
+
+|                                                                               | <i>Page</i> |
+|-------------------------------------------------------------------------------|-------------|
+| 1 Scope .....                                                                 | 1           |
+| 2 Normative references .....                                                  | 1           |
+| 3 Definitions .....                                                           | 1           |
+| 4 Abbreviations .....                                                         | 2           |
+| 5 Conformance .....                                                           | 2           |
+| 6 JPEG print-application support overview.....                                | 2           |
+| 6.1 Colour encodings and associated values to define white and black .....    | 2           |
+| 6.2 Characterization of colour or grayscale values .....                      | 3           |
+| 6.3 Order of components for images encoded with three or four components..... | 3           |
+| 6.4 Start of Frame (SOF) markers.....                                         | 3           |
+| 6.5 Application markers and marker segments .....                             | 3           |
+| 7 Conversions between colour encodings .....                                  | 4           |
+| Bibliography .....                                                            | 5           |
+
+# **Introduction**
+
+This Recommendation | International Standard specifies a subset of features and application tools for the interchange of images encoded according to the JPEG image coding standard (Rec. ITU-T T.81 | ISO/IEC 10918-1) for printing.
+
+## INTERNATIONAL STANDARD
+
+## RECOMMENDATION ITU-T
+
+# Information technology – Digital compression and coding of continuous-tone still images: Application to printing systems
+
+# 1 Scope
+
+This Recommendation | International Standard specifies a subset of features and application tools for printing applications that encode or decode images based on JPEG (Recommendation ITU-T T.81 | ISO/IEC 10918-1) encoding. Its creation was proposed by members of the digital printing industry to ensure that applications developed for printing systems can exchange JPEG images.
+
+# 2 Normative references
+
+The following Recommendations and International Standards contain provisions which, through reference in this text, constitute provisions of this Recommendation | International Standard. At the time of publication, the editions indicated were valid. All Recommendations and Standards are subject to revision, and parties to agreements based on this Recommendation | International Standard are encouraged to investigate the possibility of applying the most recent edition of the Recommendations and Standards listed below. Members of IEC and ISO maintain registers of currently valid International Standards. The Telecommunication Standardization Bureau of the ITU maintains a list of currently valid ITU-T Recommendations.
+
+- Recommendation ITU-T T.81 (1992) | ISO/IEC 10918-1:1994, *Information technology – Digital compression and coding of continuous-tone still images – Requirements and guidelines*.
+- Recommendation ITU-T T.871 (2011) | ISO/IEC 10918-5:2011, *Information technology – Digital compression and coding of continuous-tone still images – JPEG File Interchange Format (JFIF)*.
+- Recommendation ITU-R BT.601-6 (2007), *Studio encoding parameters of digital television for standard 4:3 and wide screen 16:9 aspect ratios*.
+- ISO 15076-1:2010, *Image technology colour management – Architecture, profile format and data structure – Part 1: Based on ICC.1:2004-10*.
+
+# 3 Definitions
+
+For the purposes of this Recommendation | International Standard, the following definitions apply:
+
+**3.1 CMYK:** 32-bit four-colour channel encoding in which the first channel consists of an eight-bit value for Cyan, the second channel consists of an eight-bit value for Magenta, the third channel consists of an eight-bit value for Yellow, and the fourth channel consists of an eight-bit value for Key (black); in the absence of appropriate metadata, the interpretation of these values is device dependent.
+
+**3.2 complement:** Subtract from 255.
+
+**3.3 grayscale:** Eight-bit single channel encoding in which the value is monochromatic, e.g., describes the intensity of light varying from white to black or from black to white.
+
+**3.4 ICC Profile:** Set of data that characterizes the input or output values of a colour device, e.g., as specified in ISO 15076-1.
+
+**3.5 JPEG File Interchange Format (JFIF):** The interchange format specified in Rec. ITU-T T.871 | ISO/IEC 10918-5 having 1 or 3 colour channels and 8 bits per colour channel.
+
+**3.6 RGB:** 24-bit three-colour channel encoding in which the first channel consists of an eight-bit value for Red, the second channel consists of an eight-bit value for Green, and the third channel consists of an eight-bit value for Blue; in the absence of appropriate metadata, the interpretation of these values is device dependent.
+
+# 4 Abbreviations
+
+For the purposes of this Recommendation | International Standard, the following abbreviations apply:
+
+|                   |                                                                                                                           |
+|-------------------|---------------------------------------------------------------------------------------------------------------------------|
+| $A_{p_i}$         | Byte $i$ of application data (specified in Rec. ITU-T T.81   ISO/IEC 10918-1)                                             |
+| APP <sub>2</sub>  | Application data marker, type 2 (specified in Rec. ITU-T T.81   ISO/IEC 10918-1)                                          |
+| APP <sub>14</sub> | Application data marker, type 14 (specified in Rec. ITU-T T.81   ISO/IEC 10918-1)                                         |
+| CMYK              | Cyan, Magenta, Yellow, and Key (black) colour component values                                                            |
+| DNL               | Define Number of Lines (specified in Rec. ITU-T T.81   ISO/IEC 10918-1)                                                   |
+| EOI               | End of Image (specified in Rec. ITU-T T.81   ISO/IEC 10918-1)                                                             |
+| ICC               | International Color Consortium                                                                                            |
+| JFIF              | JPEG File Interchange Format (specified in Rec. ITU-T T.871   ISO/IEC 10918-5)                                            |
+| JPEG              | Joint Photographic Experts Group (also used to refer to the image coding specification Rec. ITU-T T.81   ISO/IEC 10918-1) |
+| Lf                | Length of frame header (specified in Rec. ITU-T T.81   ISO/IEC 10918-1)                                                   |
+| Lp                | Length of application data segment (specified in Rec. ITU-T T.81   ISO/IEC 10918-1)                                       |
+| Nf                | Number of components in frame (specified in Rec. ITU-T T.81   ISO/IEC 10918-1)                                            |
+| RGB               | Red, Green, and Blue colour component values                                                                              |
+| SOF               | Start of Frame (specified in Rec. ITU-T T.81   ISO/IEC 10918-1)                                                           |
+| SOI               | Start of Image (specified in Rec. ITU-T T.81   ISO/IEC 10918-1)                                                           |
+| $YCbCr$           | Luminance (denoted as $Y$ ), Chrominance toward Blue, and Chrominance toward Red colour component values                  |
+| YCKK              | Luminance (denoted as $Y$ ), Chrominance toward Blue, Chrominance toward Red, and Key (black) colour component values.    |
+
+# 5 Conformance
+
+Some requirements in this Recommendation | International Standard are expressed as format or syntax requirements rather than as software or hardware implementation requirements. Implementations fall into two categories: JPEG print-application supporting decoders and JPEG print-application supporting encoders.
+
+In order for a JPEG print-application supporting decoder to be considered conforming, the decoder shall not report errors when processing conforming instances of the specified format, except when forced to do so by resource exhaustion.
+
+NOTE – The decoder should report errors when processing non-conforming deviations from the specified format.
+
+In order for a JPEG print-application supporting encoder to be considered conforming, the files produced by the encoder shall be formatted as specified.
+
+# 6 JPEG print-application support overview
+
+## 6.1 Colour encodings and associated values to define white and black
+
+Images encoded with one or three or four components in the start of frame (SOF) marker segment as specified in 6.4 shall be supported. In the absence of other information or metadata, such as a file format, container, or other printing system mechanism that specifies the interpretation of the colour or grayscale values of the image, then the interpretation of such colour or grayscale values is as follows:
+
+- Images encoded with only one component are assumed to be grayscale data in which 0 is black and 255 is white.
+- Images encoded with three components are assumed to be *RGB* data encoded as  $YCbCr$ , unless the image contains an APP<sub>14</sub> marker segment as specified in 6.5.3, in which case the colour encoding is considered either *RGB* or  $YCbCr$ , according to the application data of the APP<sub>14</sub> marker segment. The relationship between *RGB* and  $YCbCr$  is defined as specified in Rec. ITU-T T.871 | ISO/IEC 10918-5.
+
+- Images encoded with four components are assumed to be *CMYK*, with (0,0,0,0) indicating white unless the image contains an APP<sub>14</sub> marker segment as specified in 6.5.3, in which case the colour encoding is considered either *CMYK* or *YCKK* according to the application data of the APP<sub>14</sub> marker segment. The relationship between *CMYK* and *YCKK* is defined as specified in clause 7.
+
+## 6.2 Characterization of colour or grayscale values
+
+An APP<sub>2</sub> marker segment encoded as specified in 6.5.2, if present in the image, shall contain an ICC profile that can be used to characterize the colour or grayscale values of the image. If no such marker is present, then information that can be used to characterize the colours or grayscales is assumed to be known to the decoder by some other means.
+
+## 6.3 Order of components for images encoded with three or four components
+
+The ordering of components for images encoded with three components using *YC<sub>b</sub>C<sub>r</sub>* colour encoding is such that the first component in the image is the *Y* channel, the second component is the *C<sub>b</sub>* channel, and the third component is the *C<sub>r</sub>* channel.
+
+The ordering of components for images encoded with three components using *RGB* colour encoding is such that the first component in the image is the red channel, the second component is the green channel, and the third component is the blue channel.
+
+The ordering of components for images encoded with four components using *CMYK* colour encoding is such that the first component in the image is the cyan channel, the second component is the magenta channel, the third component is the yellow channel, and the fourth component is the black channel.
+
+The ordering of components for images encoded with four components using *YCKK* colour encoding is such that the first component in the image is the *Y* channel, the second component is a first *C* channel with chrominance toward blue, the third component is a second *C* channel with chrominance toward red, and the fourth component is the *K* (i.e., black) channel.
+
+## 6.4 Start of Frame (SOF) markers
+
+The following SOF markers shall be supported:
+
+X'FFC0' – Baseline DCT.
+
+X'FFC1' – Huffman Extended Sequential DCT.
+
+X'FFC2' – Huffman Progressive DCT.
+
+No other SOF markers shall be present.
+
+For the Huffman Progressive DCT data, both full progression and spectral selection as defined in Annex G of Rec. ITU-T T.81 | ISO/IEC 10918-1 shall be supported by conforming decoders.
+
+NOTE 1 – A single image can be encoded using full progression which is spectral selection within successive approximation or the allowed subset of spectral selection alone.
+
+The following SOF marker fields have values that are restricted as described below:
+
+**Sample precision:** Shall be 8.
+
+**Number of lines:** Shall be a positive number. The DNL marker shall not be present.
+
+NOTE 2 – Rec. ITU-T T.81 | ISO/IEC 10918-1 allows a value of zero to be specified for the number of lines to indicate that a subsequent DNL marker is intended to provide the number of lines for the image.
+
+**Number of components in frame:** Shall be 1, 3 or 4.
+
+## 6.5 Application markers and marker segments
+
+### 6.5.1 Application markers interpreted by conforming decoders
+
+The following application markers and marker segments shall be interpreted by conforming decoder implementations
+
+X'FFE2' – APP<sub>2</sub> marker to identify ICC profiles as specified in 6.5.2.
+
+X'FFEE' – APP<sub>14</sub> marker to identify colour encoding as specified in 6.5.3.
+
+### 6.5.2 APP<sub>2</sub> marker segments for International Color Consortium (ICC) profiles
+
+Marker segments containing an APP<sub>2</sub> marker and the first twelve bytes of the application data AP<sub>i</sub> (for  $i = 1$  to 12) of the segment coded as X'49', X'43', X'43', X'5F', X'50', X'52', X'4F', X'46', X'49', X'4C', X'45', X'00' (the zero-terminated string "ICC\_PROFILE", according to Rec. ITU-T T.50 or ISO/IEC 646 coding) shall identify an APP<sub>2</sub> marker segment for ICC profiles. Application data immediately following the zero-terminated string "ICC\_PROFILE" shall contain ICC Profile data. If multiple APP<sub>2</sub> marker segments for ICC profiles are present in the image, the data from the multiple APP<sub>2</sub> marker segments are concatenated to obtain a single ICC Profile as specified in ISO 15076. Multiple APP<sub>2</sub> marker segments for ICC profiles, if used to obtain a single ICC profile, shall be present in the image prior to the first SOS marker.
+
+#### 6.5.3 APP<sub>14</sub> marker segment for colour encoding
+
+A marker segment containing an APP<sub>14</sub> marker and the first six bytes of the application data AP<sub>i</sub> (for  $i = 1$  to 6) of the segment coded as X'41', X'64', X'6F', X'62', X'65', X'00' (the zero-terminated string "Adobe", according to Rec. ITU-T T.50 or ISO/IEC 646 coding) shall identify an APP<sub>14</sub> marker segment for colour encoding. AP<sub>12</sub> is assumed to contain a single-byte transform flag as defined below; the rest of the marker segment is ignored.
+
+Transform flag values of 0, 1 and 2 shall be supported and are interpreted as follows:
+
+- 0 – *CMYK* for images that are encoded with four components in which all four *CMYK* values are complemented; *RGB* for images that are encoded with three components; i.e., the APP<sub>14</sub> marker does not specify a transform applied to the image data.
+- 1 – An image encoded with three components using *YC<sub>b</sub>C<sub>r</sub>* colour encoding.
+- 2 – An image encoded with four components using *YCKK* colour encoding.
+
+### 6.5.4 Other application marker segments used for application-specific information
+
+Other application marker segments may be used to hold application-specific information that does not affect the ability to decode the image.
+
+## 7 Conversions between colour encodings
+
+Conversion between the *RGB* and *YC<sub>b</sub>C<sub>r</sub>* colour encodings uses the process specified in Rec. ITU-T T.871 | ISO/IEC 10918-5.
+
+*YCKK* is obtained from *CMYK* by converting the *CMY* channels to *YCC* channels using the process specified in Rec. ITU-T T.871 | ISO/IEC 10918-5 for conversion of *RGB* channels to *YC<sub>b</sub>C<sub>r</sub>*, but with *C* (Cyan) substituted for *R* (Red), *M* (Magenta) substituted for *G* (Green), and *Y* (Yellow) substituted for *B* (Blue); the first *C* of *YCKK* is the value *C<sub>y</sub>* and the second *C* of *YCKK* is the value *C<sub>r</sub>* that result from that process. The *K* value in *YCKK* is computed by complementing the black channel value in *CMYK*.
+
+# Bibliography
+
+- Recommendation ITU-T T.50 (1992), *International Reference Alphabet (IRA) (Formerly International Alphabet No. 5 or IA5) – Information technology – 7-bit coded character set for information interchange.*
+- ISO/IEC 646:1991, *Information technology – ISO 7-bit coded character set for information interchange.*
+
+
+
+
+
+## SERIES OF ITU-T RECOMMENDATIONS
+
+|                 |                                                                                             |
+|-----------------|---------------------------------------------------------------------------------------------|
+| Series A        | Organization of the work of ITU-T                                                           |
+| Series D        | General tariff principles                                                                   |
+| Series E        | Overall network operation, telephone service, service operation and human factors           |
+| Series F        | Non-telephone telecommunication services                                                    |
+| Series G        | Transmission systems and media, digital systems and networks                                |
+| Series H        | Audiovisual and multimedia systems                                                          |
+| Series I        | Integrated services digital network                                                         |
+| Series J        | Cable networks and transmission of television, sound programme and other multimedia signals |
+| Series K        | Protection against interference                                                             |
+| Series L        | Construction, installation and protection of cables and other elements of outside plant     |
+| Series M        | Telecommunication management, including TMN and network maintenance                         |
+| Series N        | Maintenance: international sound programme and television transmission circuits             |
+| Series O        | Specifications of measuring equipment                                                       |
+| Series P        | Terminals and subjective and objective assessment methods                                   |
+| Series Q        | Switching and signalling                                                                    |
+| Series R        | Telegraph transmission                                                                      |
+| Series S        | Telegraph services terminal equipment                                                       |
+| <b>Series T</b> | <b>Terminals for telematic services</b>                                                     |
+| Series U        | Telegraph switching                                                                         |
+| Series V        | Data communication over the telephone network                                               |
+| Series X        | Data networks, open system communications and security                                      |
+| Series Y        | Global information infrastructure, Internet protocol aspects and next-generation networks   |
+| Series Z        | Languages and general software aspects for telecommunication systems                        |
\ No newline at end of file
diff --git a/marked/T/T-REC-T.89-200109-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/T/T-REC-T.89-200109-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..8ef94232ad379b90f399cee36311d5cb51372601
--- /dev/null
+++ b/marked/T/T-REC-T.89-200109-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:78f0625ff957c350eb0d5998c514cb05d4ee3d0c586c9a31ca291699e805dfe2
+size 8289